Materials Science and Engineering Commons^™

Numerical Simulation Of Centrifugal Pump Performance Under Impeller Blade And Suction Diameter Variations, Gunawan Budi Santoso, Susanto -, Akhmad Nuriyanis, Anang Budhi Nugroho, Rizka Noor Miftakhul Ulum, Suyono -

Journal of Mechanical Engineering Science and Technology (JMEST)

The objective of this study is to model variations in pump geometry to obtain optimal performance under the effects of cavitation. The resulting geometric variation models were then simulated using ANSYS Fluent software. The first geometric variation model used a standard 5-blade impeller with suction pipe diameter variations of 2, 2 ½, 2 ¾, 3, 3 ¼, 3 ½, and 4 inches. The second geometric variation model for simulation used a standard 3-inch suction pipe with impeller blade variations of 3, 4, 5, 6, 7, 8, and 9. The simulation results indicated that the number of blades without changes in …

Multifunctional Engineering Of Manganese Malate For Supercapacitors, Krithika M Ms

Theses and Dissertations

Supercapacitors are promising energy storage devices owing to their rapid charge-discharge capability and long cycle-life. Based on the charge storage mechanism, supercapacitors are broadly categorised into electric double-layer capacitors (EDLCs), pseudocapacitors and hybrid capacitors. In this work, manganese malate (MnM) is systematically developed as a versatile electrode material for supercapacitor applications through rational synthesis, textural engineering, compositional modification, phase transformation and sustainable resource utilisation.

In Chapter 2, MnM was electrodeposited onto stainless-steel foil via chronoamperometry at 2, 3 and 4 V. MnM electrodeposited at 2 V (MnM2) exhibits a specific capacitance of 186 F g-1 at 1 A g-1 with …

Effect Of Naoh Concentration On The Structural, Morphological, And Tensile Properties Of Pineapple Stem Fibers, Ahmad Norca Kurnia Zen, Heru Suryanto, Aminnudin Aminnudin, Fajar Nusantara, Joseph Selvi Binoj

Journal of Mechanical Engineering Science and Technology (JMEST)

Natural fiber reinforced composites are increasingly being developed due to their environmentally friendly nature, low production costs, and safety for human health. However, the presence of lignin and hemicellulose reduces adhesion properties between fiber and composite matrix. Alkalization treatment is an effective way to remove lignin and hemicellulose attached to cellulose. This study aims to determine the optimum concentration of NaOH used during alkalization process of pineapple stem fiber. The methods included the retting process of fibers from pineapple stems. The obtained fibers were soaked in variations of 2%, 4%, 6%, and 8% NaOH for 4 hours,  then dried and …

Comparative Lca Of Germanium Production From Coal Fly Ash Using Chlorinated Distillation And Solvent Extraction, Dennis Dadzie, Kwame Awuah-Offei, Michael Moats, Nasib Al Habib, Weston Hartzell

Mining Engineering Faculty Research & Creative Works

Germanium is increasingly important for high-tech applications, yet its supply chain is vulnerable, with production limited to a few countries. Although prior research has explored alternative techniques for extracting and recovering germanium, the literature lacks comparative life-cycle evidence that quantifies their environmental burdens and translates findings into actionable (policy) recommendations. This paper presents a cradle-to-gate life-cycle assessment that compares the environmental burdens of producing 1 kg of single-crystal germanium from coal fly ash via chlorinated distillation (CD) and solvent extraction (SX). Under the study's assumptions, CD has lower potential impacts in 15 of 19 impact categories, while both routes show …

Electrospinning Of Covalent Organic Frameworks (Cofs) For Adsorption Of Heavy Metal Ions, Samar A. Salim

Nanotechnology Research Centre

This study reported the synthesis, electrospinning, and heavy metal adsorption of covalent organic frameworks (COFs) integrated into poly(methyl methacrylate) (PMMA) nanofibers. COF-1 and COF-2 were synthesized by solvothermal and reflux techniques, respectively, and subsequently incorporated into PMMA via electrospinning with different loadings (0.1%, 0.5%, and 1.0%). The synthesized PMMA_COF nanofibers were analyzed utilizing X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and diffuse reflectance spectroscopy (DRS). PMMA_COF nanofibers with fiber diameters of 350-450 nm were obtained. The structural and morphological investigations validated the effective integration of COFs into the PMMA matrix, with COF-1 demonstrating superior dispersion …

The Arching Analysis Of Rigid Inclusion System Using Cohesive Fill For Load Transform Platform, Ramy Mohammed Mohammed Khalil, Amr F. Elhakim

HBRC Journal

Rigid Inclusion System (RIS) is one of the economic systems for improving highly compressible soil by increasing the bearing capacity of foundation soil and reducing settlements. This system consists of a load transform platform (LTP) with or without geosynthetic reinforcement (GR) membrane resting on an arrangement of piles. The LTP redistributes the fill embankment load so that a higher percentage of load is transferred to pile by arching that leads to a reduction in the settlement of the foundation soil. Many analytical, numerical and experimental studies to model arching within LTP using cohesionless fill are summarized. This paper presents an …

Effect Of Recycled Water As Mixing And Curing Water, On Concrete Properties, Nagah Mousalem, Sayed Abdelbaky, Hesham Ali Ezz-Eldeen, Ahmed Abdel Hafiz Mahmoud

HBRC Journal

This research aims to study the effect of secondary treated wastewater (STWW) and tertiary treated wastewater (TTWW) in concrete mixing and curing as a complete alternative to fresh water to address the water crisis. The treated wastewater used in the study was collected from two wastewater treatment plants in Orasqualia for STWW and El Shorouk for TTWW, Egypt. Chemical analysis was performed on the collected water samples to verify their compliance with the recommendations of the relevant standards used in concrete production. Physical and mechanical tests were performed on cement paste, mortar and concrete specimens. Some durability characteristic of concrete …

Improving Heat Transfer Properties Of Corundum Alumina-Based Nanofluids: A Comprehensive Study On Thermal Conductivity And Characterization, Amri Abdulah, Budi Kristiawan, Wibawa Endra Juwana, Sukarman Sukarman, Khoirudin Khoirudin

HBRC Journal

The thermal conductivity of nanofluids is affected by various factors. Consequently, a comprehensive investigation into nanofluid materials and their thermal conductivity is essential. This study examines Al₂O₃ samples with three different volume concentrations, 0.5, 0.75 and 1 vol.%, dispersed in a liquid water/ethylene glycol mixture with a volume ratio of EG–W (50:50). Multi-technique characterization was performed using XRD, SEM-EDS, TEM, UV-Visible, and Zeta Potential. Furthermore, thermal conductivity tests were performed on Al₂O₃ using TEMPOS TEM-1443. The XRD pattern revealed that the Al₂O₃ nanoparticles possess a trigonal crystal system with a rhombohedral …

Divergent Risk Prioritization And Safety Governance In Metro Construction Projects: Evidence From Cairo Metro Line 3, Shrouk M. El Gebaly, Khaled M. Dewidar, Taher M. Elsamni

HBRC Journal

Safety risk management remains a critical challenge in large-scale infrastructure projects, particularly in complex urban metro systems where multiple stakeholders operate under different organizational mandates. While previous research has examined construction safety risks, limited studies have explored how project stakeholders prioritize these risks within the same project environment and how such differences influence safety governance. This study investigates stakeholder risk prioritization in metro construction through a qualitative case study of Cairo Metro Line 3 in Egypt. Data were collected through semi-structured interviews with representatives from three key stakeholder groups: the client organization, consulting engineers, and construction contractors. The data were …

Performance Evaluation And Sustainable Benefits Of Using Metakaolin And Recycled Steel Fibers In Concrete, Lova Raju Surla, Ramprasad Naik Desavathu, Raja Murugadoss Jeyaraju

Journal of Sustainable Construction Materials and Technologies

The rapid accumulation of waste vehicle tires and the increasing demand for cement pose significant environmental challenges through land pollution and CO2 emissions. The combined use of recycled steel fibers (RSFs) recovered from waste tires and supplementary cementitious materials (SCMs) offers a sustainable solution to these issues. This study investigates concrete incorporating 20% fly ash (FA), varying metakaolin (MK) contents (4–16%), and RSF dosages of 0.5–1.5%. Mechanical properties (compressive, split tensile, and flexural strengths) and durability characteristics (sorptivity, water absorption, chloride permeability, and homogeneity) were evaluated at 7, 28, and 90 days. Results showed that the mixture containing 20% FA …

Climate-Responsive Design For Sustainable Construction: Passive Strategies In Domestic Architecture Supporting Sustainability, Nahed Chakouf

Journal of Sustainable Construction Materials and Technologies

This study explores climate-responsive design in domestic architecture, focusing on the application and effectiveness of passive strategies across various climatic regions, including the UK, hot-arid, tropical, and cold climates. A qualitative comparative case study method was used to explore different passive design strategies, integration of sustainability, procurement, the coordination of stakeholders, and compliance with regulations in residential architectural projects under varying climate conditions. Drawing from a combination of historical case studies and original architectural projects, the research evaluates how spatial configuration, material selection, solar orientation, shading, ventilation, and insulation are optimized to achieve thermal comfort and energy efficiency. In temperate …

Optimization Of Aluminum Coating Deposition Parameters To Enhance The Performance Of Automotive Headlamps, Gulirano Saidakhmedova, Giovanni Maizza

Technical science and innovation

The paper investigates the influence of the optical characteristics of functional coatings applied to automotive reflectors on vehicle active safety parameters, with a focus on the range and intensity of road illumination. The study examines the mathematical relationship between the maximum luminous intensity of a headlamp, the object detection distance, and the reflection coefficient  of an aluminium layer deposited via vacuum thermal evaporation. The main factors driving the degradation of surface reflectivity (including oxidation, thermal degradation of the base coat, and surface roughness) are analysed. It is demonstrated that a decrease in the reflection coefficient during operation directly impairs the …

Harnessing Tio2-Based Nanofilaments: A Pathway To Enhanced Optoelectronic Performance In Dye-Sensitized And Perovskite Light Harvesters, Zahraa Ismail, Tarek A. Elmelegy, Hassan Nageh, Sameh Abdellatif

Mechanical Engineering

This study explores the integration of TiO2-based nanofilaments into dye-sensitized solar cells (DSSCs) and perovskite solar cells (PSCs) to enhance their optoelectronic performance. Despite the advancements in one-dimensional lepidocrocite TiO2 nanofilaments, there remains a significant gap in understanding their optical scattering mechanisms and dual applicability in both types of solar cells. We synthesized TiO2 nanofilaments and compared their performance to conventional P25 TiO2 in terms of morphology, electrical, and optical properties. The results indicate that the DSSC utilizing nanofilaments achieved a short-circuit current density of 8.2 mA/cm² and a power conversion efficiency (PCE) of 6.9%, compared to 7.1 mA/cm² and …

Sigesn-Based Lasers On Silicon For Mid-Infrared Optoelectronics, Sudip Acharya

Graduate Theses and Dissertations

Germanium-tin (GeSn) alloys represent a significant advancement in semiconductor technology, particularly for applications in the short-wave and mid-infrared (SWIR and MIR) spectral ranges. As a group IV material system, these alloys offer a unique combination of tunable optoelectronic properties and full compatibility with established silicon-based manufacturing processes. The controlled incorporation of tin into germanium enables the engineering of a fundamental direct bandgap, a critical feature that distinguishes GeSn from its indirect bandgap materials, silicon and germanium. This direct bandgap behavior which was demonstrated in high-quality single crystalline GeSn alloys around the year 2015 is the foundation for efficient light emission …

Thermal Transport Tuning Via Nanoscale Hierarchical Frameworks For Fe2val Thermoelectric Materials, Apoorva Pradip Joshi

Dartmouth College Master’s Theses

Waste heat represents a vast, untapped energy resource. Thermoelectric materials offer a promising route to harvest this energy by directly converting thermal gradients into electricity. The Heusler alloy Fe2VAl is a prime candidate for such applications because it is non-toxic and cost-effective. However, its intrinsically-high thermal conductivity severely limits performance. A detailed understanding of thermal transport mechanisms is therefore essential for improving its thermoelectric efficiency. This work examines the effect of atomic disorder on the thermal transport behaviour of Fe2VAl. We use germanium doping to introduce atomic-scale disorder and demonstrate a substantial reduction in thermal conductivity, from 28 W/m-K in …

Nb–Zr Interdiffusion In The (Hf,Ta,Ti,Nb)B2–(Hf,Ta,Ti,Zr)B2 High-Entropy Boride System, Ana C. Feltrin, Yue Zhou, Stefano Curtarolo, Gregory E. Hilmas, William G. Fahrenholtz

Materials Science and Engineering Faculty Research & Creative Works

Niobium (Nb) presents a challenge for achieving homogeneous solid solutions in high-entropy boride and carbide ceramics. In this work, we synthesized (Hf,Ta,Ti,Zr)B₂ (Zr-HEB) and (Hf,Ta,Ti,Nb)B₂ (Nb-HEB) ceramics by boro/carbothermal reduction, followed by densification via spark plasma sintering (SPS). Diffusion couples were prepared to investigate the interdiffusion behavior of Nb and zirconium (Zr) in these complex systems at temperatures between 2000°C and 2200°C. Aside from Nb and Zr, the other elements exhibited no significant concentration gradient across the diffusion interface. Nb exhibited lower diffusion coefficients ((Formula presented.) Nb = 1.7 x 10⁻¹⁷–1.2 x 10⁻¹⁶ m^{2 …}

Magnetic Field-Induced Transformation In Polycrystalline Ni2mnal Heusler Type Magnetic Shape Memory Alloy, Choji J. Daches, Joseph W. Newkirk, Mario Buchely, Laura N. Bartlett

Materials Science and Engineering Faculty Research & Creative Works

The martensitic and magnetic transformations, as well as the mechanical properties, of Ni₂MnAl alloys in as-cast (AC) and heat-treated (HT) conditions were investigated. Magnetic-field-induced strain was evaluated via magnetostriction, with reversible strains of 0.14% and 0.2% achieved in the martensitic phase at 2 K for the AC and HT alloys, respectively. Transformation temperatures and Curie temperatures were determined under constant applied magnetic field, revealing that γ-phase inclusions in the AC microstructure suppress antiferromagnetic domain response, yielding a lower magnetization (∼8.4 emu g⁻¹) compared to the HT alloy (∼13.4 emu g⁻¹). Both alloys exhibited hysteretic behavior in the martensitic state and …

Unveiling Corrosion Behavior And Passive Film Performance Of L12-Strengthened Ni28cr15cu8ti8fe26-Xco15+X Multi-Principal Element Alloys, Liran Huang, Zhiqiang Fu, Chenliang Chu, Shiyu Liu, Xiaohui Qin, Yunzhu Shi, Yongxiang Tan, Haiming Wen

Materials Science and Engineering Faculty Research & Creative Works

L12 precipitates are usually induced into face-centered cubic (FCC) multiple-principal element alloys (MPEAs) to improve their moderate yield strength; however, the precipitation also influences the corrosion resistance. This study investigated the corrosion behavior and passive film performance of a series of L1₂-strengthened Ni₂₈Cr₁₅Cu₈Ti₈Fe_26-xCo_15+x (x = 0, 3, 6, and 9 at.%) MPEAs in 3.5 wt.% NaCl solution. The size and density of the L1₂ nanoprecipitates were regulated via tuning Fe and Co content. With decreasing Fe/Co ratio, the radii of these nanoprecipitates gradually increased within the …

Thiol-Based Neuroprotective Copolymers Acutely Restore Redox Metabolism And Mediate Vasogenic Edema In A Mouse Model Of Traumatic Brain Injury, Evan T. Curtis, Brandon Z. Mcdonald, Aria W. Tarudji, Aaron M. Priester, Anthony J. Convertine, Forrest M. Kievit

Materials Science and Engineering Faculty Research & Creative Works

Effective pharmaceutical interventions for treating the secondary damage associated with traumatic brain injury (TBI) are limited due to poor delivery into the brain, insufficient target engagement, and an incomplete understanding of the pathophysiological changes that occur post-impact. Thus, nanoparticles (NP), which have an enhanced permeation and retention-like effect within the perturbed blood-brain barrier, have grown as a potential candidate for treating TBI. We have investigated the antioxidant capacity of thiol-based NP, termed neuroprotective copolymers (NPC3), and their ability to neutralize reactive oxygen species (ROS) and lipid peroxidation products (LPOx). Here, we assessed the efficacy of NPC3 for alleviating the secondary …

Finite-Temperature Grain-Boundary Segregation In High-Entropy Carbides, Marium M. Mou, Tarek Md Anamul Haque, Samuel E. Daigle, Josiah Roberts, William G. Fahrenholtz, Jon Paul Maria, Douglas E. Wolfe, Eva Zurek, Stefano Curtarolo, Donald W. Brenner

Materials Science and Engineering Faculty Research & Creative Works

High-entropy carbides are promising candidates for extreme-temperature environments, but their grain-boundary chemistry remains difficult to resolve because segregation involves both chemical disorder and finite-temperature configurational sampling. Here, we quantify temperature-dependent grain-boundary segregation in high-entropy carbides using a universal message-passing atomic cluster expansion (MACE) machine learning interatomic potential combined with a hybrid Monte Carlo–molecular dynamics workflow. A 53.1 (Formula presented.) (Formula presented.) symmetric tilt grain boundary was sampled for six representative high-entropy carbide compositions containing group IV, V, and VI transition metals at 300 and 2000 K. Element-resolved metal-sublattice composition profiles reveal composition-dependent segregation modes. Several chemistries exhibit selective near-boundary enrichment …