Engineering Science and Materials Commons^™

Surface Characteristics Of Montmorillonite Reinforced Cellulose Membranes Derived From Pineapple Waste, Naufal Rizky Amasda, Heru Suryanto, Aminnudin Aminuddin, Uun Yanuhar, Nanda Lidya Cinta Aulia Sari, Agus Suyetno, Komarudin Komarudin, Fajar Nusantara, Gaguk Jatisukamto, Aulia Surya Ramadhan

Journal of Metals, Materials and Minerals

This study aims to investigate the effect of montmorillonite on the surface characteristics and porosity of bacterial nanocellulose (BNC) membranes derived from pineapple peel waste. The bacterial cellulose was synthesized using Acetobacter xylinum using pineapple peel extract as medium component. Bacterial nanocellulose membrane (BNC) was obtained by crushing and homogenizing bacterial cellulose in a high-pressure homogenizer. BNC membrane was reinforced with montmorillonite content of 2 wt% to 8 wt%. The membrane was characterized for its properties using SEM, FTIR, surface roughness tester, tensile tester, water holding capacity test, and BET analysis. The results showed that montmorillonite was well-dispersed within BNC …

Assessing The Influence Of Land Use Land Cover Alterations On Climate Variability In Thimphu & Chhukha, Sonam Zangpo, Karma Choki, Tashi Tobgay, Phurpa Rinchen, Tandin Tshewang

ASEAN Journal on Science and Technology for Development

This study examines the spatiotemporal dynamics of land use and land cover (LULC) changes and their influence on local climate variability in Bhutan using an integrated geospatial and machine learning framework. LULC changes during the period 2004 to 2022 were analyzed to understand their relationship with localized climate responses. Despite increasing urbanization pressures, comprehensive assessments linking LULC dynamics with climate variability in Bhutan remain limited. Geographic Information System (GIS) techniques and Random Forest classification were used to map LULC changes, while non-parametric trend analyses (Mann–Kendall test and Sen’s slope estimator) were applied to evaluate trends in key meteorological variables, including …

Automation And Habitat Development For A Space Based Marine Life Environment, Logan Trimmer, Alexander Hang

Harrisburg University Other Works

This project was a cross-collaboration between the Environmental Sciences and Advanced Manufacturing and Robotics programs for the company Monolith Space.

The goal of this project was to design an autonomous system to be able to track qualities of water in an aquaculture system designed to be sent to space.

The Efficacy Of Hybrid Manufacturing For High Stress Automotive Components, Logan Trimmer

Harrisburg University Other Works

The goal of this research was to establish the viability of using hybrid manufacturing for automotive applications. By verifying that high-stress components can be created, it can be assumed that any other lower stress part could be made to match the strength requirements. A limiting factor of adoption for hybrid manufacturing is how new the technology is. Studies on time and cost were performed allowing for comparisons with traditional manufacturing technologies (casting, forging, milling) used in automotive applications. This research utilized a Haas Automation UMC750 5-axis CNC mill with a Meltio laser wire direct energy deposition attachment. Fusion 360 was …

Synthesis And Photoluminescence Properties Of Graphene Quantum Dots Prepared Via Carbonization Under Pressure Reduction, Sutthipoj Wongrerkdee, Pichitchai Pimpang

Journal of Metals, Materials and Minerals

This study reports the synthesis of graphene quantum dots (GQDs) via a bottom-up carbonization approach using citric acid as a precursor under various reduced pressure conditions. The carbonization process was carried out at 250℃ in an ethanol medium, with atmospheric pressures ranging from normal to 20 inHg below atmospheric pressure. The effects of pressure reduction on the size and optical properties of GQDs were systematically investigated. Dynamic light scattering (DLS), UV–Vis spectroscopy, and fluorescence spectroscopy revealed that pressure reduction during synthesis decreased GQDs size and induced a blue-shift in both absorption and emission spectra. The optical bandgap of GQDs was …

Development Of 4-Vinylbenzyl Chloride (Vbc) Grafted Onto Branched Polyethylenimine (Pei) Onto Bacterial Cellulose Sheet By Gamma-Induced Irradiation Technique For Cu Ion Adsorption, Methinee Wongwai, Supitchaya Kulratkitiwong, Thitirat Rattanawongwiboon, Sarute Ummartyotin

Journal of Metals, Materials and Minerals

Bacterial cellulose extracted and purified from Nata de coco was employed as a platform for Cu2+ ion adsorption. 4-vinylbenzyl chloride (VBC) was successfully grafted at the hydroxyl position by using gamma irradiation. The optimum was typically related to VBC concentration of 2% (v/v) and a radiation dose of 50 kGy. FTIR significantly reported the functional group of C-Cl related to VBC. No change of crystallinity and morphology was observed. The thermal decomposition was stable up to 200℃. The modification of branched polyethylenimine (PEI) was prepared in order to change the functionality to N‒H stretching. This was expected to adsorb Cu2+ …

High Temperature Storage Reliability Of Cu Pillar Flip Chip Interconnects, Kachain Worapakdee, Anusara Srisrual

Journal of Metals, Materials and Minerals

The Cu pillar flip chip is currently designed and used in the optic communication device that it has exhibited low reliability at high temperature. This paper aims to report the reliability of Cu pillar flip chip assembled on electronics board for a new optoelectronic product subjected to high temperature storage testing. The test was performed at 150℃ isothermal condition with the various storage times up to 2000 h. The aged samples were characterized with scanning acoustics microscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy. Two types of intermetallic compounds (IMCs) were found at beside of the Cu pillar i.e. …

Simplified Function For Predicting Superconducting Critical Temperature, Pakin Tasee, Nattawut Natkunlaphat, Udomsilp Pinsook

Journal of Metals, Materials and Minerals

Currently, there is intense competition to develop models that can accurately estimate the critical temperature across a wide range of superconductors, while striving for straightforward derivations and comprehensive predictions. In this work, we present an approach to determining the critical temperature based on the linearized Eliashberg gap equations employing the bandwidth model. To verify the accuracy of our model, we collect Eliashberg spectral functions from various independent studies, compute the necessary parameters, and solve the Eliashberg gap equations numerically to obtain the exact solutions, along with utilizing the modified Allen-Dynes equation. The findings suggest that both models are in good …

An Integrated Experimental–Numerical Approach For Characterizing Deformation Behavior Of High-Strength Steels, Weerapong Julsri, Apichat Sanrutsadakorn, Vitoon Uthaisangsuk

Journal of Metals, Materials and Minerals

This study aims to establish an integrated experimental–numerical framework for characterizing the deformation behavior of DP590 high-strength steel sheet. The framework combines experimental uniaxial tensile and Nakajima tests with finite element (FE) simulations to provide a comprehensive assessment of forming limits and fracture behavior. Forming limit curves (FLCs) and forming limit stress curves (FLSCs) were determined with the integrated approach and then validated numerically using the Hill’48 yield criterion together with both Swift and Voce hardening laws. Model calibration incorporated experimental data on directional mechanical properties to ensure that material anisotropy was accurately represented. The FE simulations demonstrated strong agreement …

Controlled Release Of Holy Basil Essential Oil Nanoemulsion Encapsulated In Gelatin/ Carboxymethyl Cellulose Hydrogel For Wound Care, Shehbaz Ameer, Pranut Potiyaraj, Tu Minh Tran Vo

Journal of Metals, Materials and Minerals

Holy basil essential oil (HBEO) is a therapeutic agent recognized for its antioxidant, anti-inflammatory, and wound-healing properties. However, its clinical use is limited by poor aqueous solubility, volatility, and instability. Nanoemulsion (NE) is an effective strategy to overcome these limitations. In this study, 1% HBEO in 0.5% polyvinyl alcohol (PVA) aqueous solution formulation yielded nanosized droplets (182±3 nm, PDI = 0.286) and showed sustained release, with 92% drug release over 30 h, compared to the rapid release for 1% HBEO in pure water. To further enhance stability and biocompatibility, the HBEO nanoemulsion (HBEONE) was incorporated into a glutaraldehyde (GA) crosslinked …

Novel Eco-Friendly Composites: Crotalaria Pallida (Cp) Fiber Reinforced Guar Gum/ Polyvinyl Alcohol Blends For Enhanced Mechanical And Thermal Properties, Tirupati Rao Bantu, Renjis T. Tom, Delse P. Sebasian, Anitha C. Kumar

Journal of Metals, Materials and Minerals

Eco-friendly composites exhibit promising applications in wound dressings, tissue engineering, sustainable packaging, and environmental cleanup. This study investigates the development of novel biodegradable composites utilizing guar gum (GG), polyvinyl alcohol (PVA), and Crotalaria pallida (CP) fibers, along with wood and nanocellulose, and their characterization. The integration of natural and synthetic polymers with plant fibers enhances mechanical strength, thermal stability, and water resistance. In this study, different loadings of CP material (0.0 g, 0.50 g, 0.75 g, and 1.0 g) and constant amounts of GG and PVA were used to fabricate hybrid films. Fourier Transform Infrared Spectroscopy (FT-IR) analysis revealed significant …

Carbon Precipitation On Metal Nanostructures And Diamond Surfaces, Komkrit Rientong, Akkarach Sukserm, Nattakarn Suntornwipat, Udomsilp Pinsook

Journal of Metals, Materials and Minerals

The interaction between diamond and a nickel (Ni) layer plays a crucial role in understanding the formation of graphene and its energy dynamics on metal-diamond substrates. In this study, we investigate the optimal positions of graphene relative to a catalyst layer on diamond by analyzing total energies obtained from self-consistent field (SCF) calculations using Quantum ESPRESSO. The structures of graphene, diamond (100), and the catalyst layers were constructed and simulated both individually and in combination. Energy comparisons between the combined structures and the sum of their individual components were conducted to identify favorable graphene positions. Our simulations show that graphene …

Zinc Oxide Functionalized Biochar From Rambutan Wood As A Novel Material To Utilize An Agricultural Waste In Thailand, Suchinda Vongsetskul Vongsetskul, Waraporn Thepthong, Supawan Kanyawilas, Narong Chanlek, Ratana Charoenwattanasatien, Wutthikrai Busayaporn, Thammasit Vongsetskul

Journal of Metals, Materials and Minerals

Zinc oxide-functionalized biochar (biochar-ZnO) from rambutan wood, an agricultural waste, was prepared to increase a value of biochar from rambutan, an important economic fruit crop in Thailand, for the first time. Biochar-ZnO was synthesized by a sol-gel process. X-ray diffraction (XRD) spectra suggest that the biochar consists of amorphous carbon mainly and confirm the success of zinc oxide functionalization on the biochar surface. The crystal structure of zinc oxide is hexagonal Wurtzite. The diameter of zinc oxide particles is ~20 nm. Thermogravimetric (TGA) thermograms indicate the success of biochar-ZnO preparation. A weight percentage of zinc oxide in the composite is …

Finite Element Simulation Of Surface Repair Welding Of Grade R260 Railway Rails Using Thermite Welding, Werayoot Lahamornchaiyakul, Saksit Chuenchomnakjad, Thongchai Khrueaphue, Parinyawatr Dhinnabutra

Journal of Metals, Materials and Minerals

Railway rails subjected to repetitive wheel-rail contact loads experience surface damage, including shallow cracks, groove wear, and material loss. Conventional arc welding repair presents limitations in costs, repair time, and quality consistency. This study investigates thermite welding for surface repair of pearlitic rail steel grade R260, emphasizing the effects of mold overflow configuration on thermal behavior, molten metal flow, and weld quality. A finite element framework incorporating thermal-fluid coupling was developed to simulate temperature distribution and molten metal penetration. Three mold overflow configurations were evaluated: overflow at the wear groove outer edge (Case 1), near the pouring gate (Case 2), …

A Nonlocal Lattice Particle Method For Modeling Hcp Polycrystalline Solids, Di Liu

University of Kentucky Doctoral Dissertations

Polycrystalline materials, composed of individual grains with varying grain size, shape, and crystallographic orientation are widely used in various engineering and industrial applications. Conventional applications of polycrystalline materials rely on the macroscopic performance, and the microstructural features are usually homogenized out. With the advancement of modern technologies and improvement of characterization methods, polycrystalline materials find their applications in meso- and micro-scale systems. At these length scales, the microscopic features including grain boundary characteristics significantly affect the material physical responses. As a result, the conventional continuum mechanics models become problematic, especially for material failure problems where the microstructural features play dominant …

Distributed Vibration Sensing For Identification Of Loose Connectors In Coaxial Data Transmission Lines, Saidanvar Esanjonovich Valiev, Anthony C. Okafor, Jeremiah J. Rittenhouse, Jie Huang, Daniel S. Stutts

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This study investigates the effect of vibration-induced loose connections on signal reflection (S11) for loose connection identification in aerospace coaxial cables using distributed sensing approach, which is effective in filtering the noise and identifying minor discontinuities. In this approach, a sliding gated window is applied to S11 signal, a fast Fourier transform is performed over the gated windows, cross-correlation is computed between the baseline and vibration-affected signals, and the standard deviation is mapped along the cable length. Sinewave signals from 9 kHz to 5 GHz were swept through cables with vibrating connectors under three conditions: fully tightened, loosened by 180°, …

Thermal Transformations And Mechanical Properties Of All-D-Metal Mn2fecu Heusler-Type Shape Memory Alloy, Choji J. Daches, Joseph W. Newkirk, Mario Buchely

Materials Science and Engineering Faculty Research & Creative Works

All-d-metal Heusler alloys are emerging functional materials in which magnetic ordering, lattice distortion, and mechanical behavior are strongly coupled through d–d electronic interactions. This study systematically investigates the structural, thermal, magnetic, and mechanical properties of Mn₂FeCu synthesized within a Heusler-type compositional framework. SEM/EDS revealed a dual-phase FCC-based microstructure consisting of Mn–Fe–rich and Mn–Cu–rich domains, while XRD confirmed FCC symmetry with compositional partitioning rather than full L2₁ ordering. Differential scanning calorimetry identified partial melting of the Cu-rich phase near ~ 900 °C. Dilatometry showed a thermoelastic FCC → FCT transformation at ~ 770–780 °C with a recoverable strain of ~ 0.067%. …

Modeling Of Transformation Temperatures In Cast Martensitic Stainless Steels-Ca6nm: Effects Of Composition, Heating Rate, And Grain Size, Ugochukwu Agbedo, Mario Buchely, Laura Bartlett, Caelan Kennedy

Materials Science and Engineering Faculty Research & Creative Works

Accurate prediction of the critical transformation temperatures Ac1 and Ac3 is one of the essential factors in the heat treatment of CA6NM cast martensitic stainless steel. In this study, the influence of alloy composition, heating rate, and prior austenite grain size on the critical temperatures was quantified using dilatometric measurements and statistical modeling. Six heat treatment conditions produced prior austenite grain sizes ranging from ~75 to 247 µm. Experimental results showed that grain size variations produced only minor changes in Ac1 and Ac3, indicating a weak dependence of transformation temperatures on prior austenite grain size within the investigated range. In …

Multiphysics Simulation And Experimental Validation Of Phase Transformation And Hardness In Jominy End-Quenched Low-Alloy Steels, J. S. Alabi, E. Heidari, M. F. Buchely, K. Chandrashekhara, S. N. Lekakh, R. J. O'Malley, V. A. Athavale, A. Kumar

Materials Science and Engineering Faculty Research & Creative Works

High-volume industrial continuous hot-rolled steel heat treatment processes involve sophisticated multi-phase modeling. The performance of a given process can be optimized by coupling phase transformation kinetics with the cooling conditions of the process. This study develops a multiphysics model to simulate an intensive quenching process for steel, which is inherently transient and highly dependent on numerous parameters. The simulated object was a Jominy end-quenched specimen geometry using two commercial steels, AISI 4130 and AISI 4140, with the goal of transferring a verified methodology to the heat treatment process for industrial heavy-section products (bars, slabs). The simulation employs thermal, mechanical, and …

Effect Of Complex Alloying Elements On Oxide Scale Formation And Water-Jet Descaling Performance On Continuously Cast Low-Carbon Steels, Tochukwu P. Ojiako, Tsvetkov Dmitry, Mario Buchely, Haiming Wen, Simon N. Lekakh, Ronald J. O'Malley

Materials Science and Engineering Faculty Research & Creative Works

The formation and evolution of oxide scale in contact with mold flux during continuous casting, subsequent reheating, and hydraulic descaling are strongly governed by steel chemistry. To elucidate the effect of complex alloying elements (Si, Mn, and Cr), two industrially produced continuously cast low-carbon steel grades for manufacturing stamped parts (a base and alloyed steel grade) were investigated. The objective was to determine how alloying elements influence oxidation behavior, scale morphology, interfacial adhesion, and water-jet descaling efficiency. Continuously cast slab specimens were subjected to controlled thermal and atmospheric oxidation cycles simulating multistage industrial practice. Three initial surface conditions (industrial as-cast, …