Engineering Science and Materials Commons^™

Effect Of Audio–Sonic Waves On Heat Transfer Enhancement In A Distilled Water-Based Heat Exchanger, Agggito Pringgo Tetuko, Ayu Yuswati Sari, Silviana Simbolon, Achmad M.S. Sebayang, Nur H. Effendi, Riko Ernando, Amdy Fachredzy, Nining S. Asri, Eko A. Setiadi, Perdamean Sebayang

Makara Journal of Technology

In this research, the influence of audio–sonic waves on distilled water used as the working fluid in a shell-and-tube heat exchanger was examined. The audio–sonic wave frequencies and flow rates of the cold and hot liquids were varied as follows: 4.85, 6.78, and 13.43 kHz for the audio–sonic waves; 0.3, 0.4, and 0.5 l/min for the cold liquid; and 0.76, 1.0, and 1.5 l/min for the hot liquid. An increase in the audio–sonic wave frequency enhanced both the overall heat transfer coefficient (U) and the enhancement factor (EF). The optimum values of U and EF, measured at 300 W/m3 ·°C …

Application Of Artificial Neural Network Models For Predicting Diesel And Petrol Prices In The Geographically Sparsed Regions In Tanzania, John M. Kafuku

Tanzania Journal of Engineering and Technology (TJET)

Fuel consumption in Tanzania, mainly diesel and petrol, accounts for 82 percent of the energy consumption in the country, with significant price volatility affecting market stability, availability of fuel, and investment decisions. This study uses an artificial neural network (ANN) with a backpropagating algorithm to predict fuel prices in four regions of Tanzania. Key input parameters include the currency inflation rate (CIR), the petrol fuel inventory (PFI), the diesel fuel inventory (DFI), and the fuel transport costs (FTC). The study selected the 6-10-10-2 ANN structures for Sumbawanga-Rukwa, Mpanda-Katavi, and Mbeya-Mbeya as well as 6-10-9-2 for the Songea-Ruvuma region. The results …

Clustering Mini-Grids To Enhance Power Systems Reliability In Distributed Generation, Santos Kihwele

Tanzania Journal of Engineering and Technology (TJET)

This study investigates the effectiveness of clustering mini-grids as a method to improve the reliability and operational stability of distributed generation systems in remote areas, particularly where renewable energy sources are predominant. As renewable resources like solar and wind are increasingly integrated into mini-grids, these systems face various challenges, particularly in maintaining stable voltage and frequency across interconnected networks. Such issues are compounded by the intermittent nature of renewable energy sources and the lack of extensive communication infrastructure in rural or resource-constrained settings. To address these control challenges, this study applies droop control techniques to two mini-grids in Uganda, utilizing …

Factors Affecting Adoption Of Industry 4.0 Predictive Maintenance By Manufacturing Industries: Tanzania Food And Beverage Manufacturing Industries, Fred E. Peter

Tanzania Journal of Engineering and Technology (TJET)

Industry 4.0 has increasingly become a focal point of scholarly inquiry. Nonetheless, there remains a noticeable lack of comprehensive research on the diverse and systematic factors that influence the adoption of Industry 4.0 Predictive Maintenance (PdM 4.0) in manufacturing sectors within developing regions, particularly in East Africa. This study seeks to bridge this research gap by investigating the key determinants affecting the actual implementation of PdM 4.0 in Tanzania’s food and beverage manufacturing industries. To achieve this objective, a mixed-methods research design was adopted, combining both qualitative and quantitative approaches. Qualitative data were obtained through in-depth interviews with ten industry …

Microwave Ore Pre-Treatment Review And Process Flowsheet Conceptualization, Baker F. Giyani

Tanzania Journal of Engineering and Technology (TJET)

The global demand for mineral commodities has increased dramatically over the years, and this is largely due to several factors, including technological advancements, industrialization, and a rise in population. Further, the demand keeps increasing because the ore being mined is becoming more complex, and the feed grade is declining over the years, prompting the need for innovative technologies to treat such ores more efficiently. Microwave ore pre-treatment is one of the potential technologies that can be employed to improve process performance. This is possible because ores are composed of both good-microwave heaters and poor microwave heaters, which creates thermal stresses …

Power-Beaming: Wireless Energy Transfer Using Lasers, Spencer L. Barnett

ATU Scholars Symposium

The objective of the project is to implement a wireless energy transfer system utilizing laser technology. This system involves modulating the laser’s beam profile and spatial distribution through precise optical manipulation. The energy transmitted by the laser is captured by a photovoltaic array, commonly referred to as a solar panel, which is engineered to convert incident photons into direct current (DC) electrical power. The current challenge is to develop a reliable wireless energy transfer mechanism capable of operating over extended distances, thereby overcoming the constraints imposed by wired connections, particularly in environments where wiring is impractical, such as in space. …

Design Of A Teleoperabletendon-Driven Robotic Hand, Zachary Giese, Joseph Gober, Samuel Grisham, Avery Mahan, Aspen White, Brayden May, Aspen White

ATU Scholars Symposium

This work presents the design, implementation, and validation of a 3D-printed tendon-driven robotic hand with a bi-directional wireless control system. The robotic hand emulates human anatomical principles, focusing on replicating flexion and extension mechanisms of the metacarpophalangeal (MCP), proximal interphalangeal (PIP), and distal interphalangeal (DIP) joints via a tendon-pulley system. Iterative prototyping resolved initial challenges in joint stiffness, tendon routing, and servo interference, culminating in a design where a single servo drives both flexion and extension for each joint using a bidirectional tendon control mechanism. A reliable bidirectional wireless communication framework, using Arduino Nano Every microcontrollers and NRF24L01 modules, enables …

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, …

Variation Of Membrane Electrode Assembly Catalyst Layer In Unitized Regenerative Fuel Cell, Yollanda Nurcholifah, Dedi Rohendi, Edy Herianto Majlan, Nirwan Syarif, Addy Rachmat, Dwi Hawa Yulianti, Nyimas Febrika S

Journal of Electrochemistry

A unitized regenerative fuel cell (URFC) is a device that may function reversibly as either a fuel cell (FC) or water electrolysis (WE). An important component of this device is the Membrane electrode assembly (MEA). Therefore, this study aimed to compare the performance outcomes of MEA using electrodes with single and three catalyst layers. This study measured Electrochemical Surface Area (ECSA), Electrochemical Impedance Spectroscopy (EIS), X-ray Diffraction analysis (XRD), and X-ray Fluorescence (XRF). Furthermore, the round-trip efficiency (RTE) of the MEA, as well as the performance in FC and WE mode, was measured. In comparison, The ECSA values of Pt-Ru/C …

Performance Of Co2/H2O Co-Electrolysis In A Flat-Tube Solid Oxide Electrolysis Cell Stack Under Air-Free Environment, Xiao-Hui Zhong, Fei Wang, An-Qi Wu, Bei-Bei Han, Jian-Xin Wang, Wan-Bing Guan

Journal of Electrochemistry

This work investigates the transient performance and stability of CO₂/H₂O co-electrolysis in an air-free environment using a flat-tube solid oxide electrolysis cell (SOEC) stack. The results show that the transient behavior of the stack with and without blowing gas in the air electrode is almost the same. With a current density of 0.67 A·cm⁻²@750 °C, the stack operated for over 200 h under co-electrolysis conditions with no air blowing, and the voltage drop rate of the stack was approximately 0.203%/100 hours. Microstructure analysis reveals significant loss of Ni particles and formation of an insulating …

Electrocatalytic Nitric Oxide Reduction To Yield Ammonia Over Fe3C Nanocrystals, Sen Lin, Lang Zhang, Tong Hou, Jun-Yang Ding, Zi-Mo Peng, Yi-Fan Liu, Xi-Jun Liu

Journal of Electrochemistry

Nitric oxide (NO), which generally originates from vehicle exhaust and industrial flue gases, is one of the most serious air pollutants. In this case, the electrochemical NO reduction reaction (NORR) not only removes the atmospheric pollutant NO but also produces valuable NH₃. Hence, through the synthesis and modification of Fe₃C nanocrystal catalysts, the as-obtained optimal sample of Fe₃C/C-900 was adopted as NORR catalyst at ambient conditions. As a result, the Fe₃C/C-900 catalyst showed an NH₃ Faraday efficiency of 76.5% and an NH₃ yield rate of 177.5 μmol·h^–1·cm^{–2 …}

Ordering Degree Regulation Of Pt2Nico Intermetallics For Efficient Oxygen Reduction Reaction, Chen-Hao Zhang, Han-Yu Hua, Jun-Hao Yang, Qian Zhang, Chang Yang, De-Li Wang

Journal of Electrochemistry

Alloying transition metals with Pt is an effective strategy for optimizing Pt-based catalysts toward the oxygen reduction reaction (ORR). Atomic ordered intermetallic compounds (IMC) provide unique electronic and geometrical effects as well as stronger intermetallic interactions due to the ordered arrangement of metal atoms, thus exhibiting superior electrocatalytic activity and durability. However, quantitatively analyzing the ordering degree of IMC and exploring the correlation between the ordering degree and ORR activity remains extremely challenging. Herein, a series of ternary Pt₂NiCo intermetallic catalysts (o-Pt₂NiCo) with different ordering degree were synthesized by annealing temperature modulation. Among them, the o-Pt …

Innovative Design Methodology For Durable Open-Graded Friction Course Asphalt Mixtures, Anas Abualia

LSU Doctoral Dissertations

Open-graded friction course (OGFC) is a thin asphalt mixture surface layer with a high percentage of coarse aggregates and high interconnected air voids, which provides improved skid resistance, visibility, and decreased pavement-tire noise. However, construction personnel at DOTD reported that conventional OGFC mixtures have short service life (raveling distress). Further, their structural contribution to the pavement structure is commonly neglected and designed only for functionality purposes.

The objective of this study was to develop a rational mix design methodology to improve the durability of OGFC asphalt mixtures. Specific objectives are to: (1) conduct a rheological and chemical characterization of polymer-, …

Impulse, Spring 2025, Jill Fier, Micayla Standish, Jerome J. Lohr College Of Engineering

Impulse (Jerome J. Lohr College of Engineering Publication)

2 | Faculty, Staff Honored
4 | The State of Lithium
6 | 100 Years of Ag and Biosystems Engineering
8 | Major Milestones
12 | Distinguished Engineer Geldert-Murphy
14 | Distinguished Engineering Heitkamp
16 | By the Numbers
18 | Space Grant Consortium at SDSU
20 | Healthcare Systems Engineering Program
22 | Ridgway Three-Peat
23 | Aerospace Club Launches
24 | Power and Energy Scholarships
25 | More Take Part in Nasa Challenges
26 | Weber Recognized as Student Leader
30 | Wild Hare Racing Ready
32| Sebern’s Success as Sole Operator
34 | Meink: From Prairie to …

Observations Of Sea Ice Thermal Strain And Motion At Geophysically Relevant Scales, Larson M. Kaidel

Dartmouth College Ph.D Dissertations

Ongoing and unprecedented Arctic sea ice change as a result of anthropogenic climate change impacts life in the Arctic and beyond. The sea ice cover is becoming less expansive, thinner, younger, and more dynamic. Quantifying processes and properties that differ between old versus young and thick versus thin ice is central understanding the sea ice cover, improving climate change predictions, and developing strategies to adapt and mitigate the adverse effects of sea ice loss. Therefore, we seek to better understand how a key inherent ice property, the thermal strain coefficient, changes as ice types change, and observe how sea ice …

Approach Formula To Increase Energy Efficiency Of Internal Combustion Engines In The “Green Economy” And Impact On The Natural Ecosystem, Zakirjon Ergashevich Musabekov, Hilola Zokir Qizi Uralova, Sayyodbek Ilxomjon O‘G‘Li Abdullajonov

Technical science and innovation

This article discusses, analyzes, and proposes solutions for the role of internal combustion engines in forming a "green economy", as well as ways to replace or modernize them. The relationship between internal combustion engines and the "green economy," as well as their energy efficiency and impact on natural ecosystems, is a crucial and urgent issue. These engines primarily generate energy through the combustion of petroleum-based fuels such as gasoline and diesel. However, this process releases harmful gases into the atmosphere, contributing to environmental degradation. The green economy is an economic model designed to protect the environment, ensure the efficient management …

Recent Advances In Non-Enzymatic Electrochemical Sensors For Theophylline Detection, Gustria Ernis, Yulia M T A Putri, Muhammad Iqbal Syauqi, Prastika Krisma Jiwanti, Yeni Wahyuni Hartati, Takeshi Kondo, Qonita Kurnia Anjani, Jarnuzi Gunlazuardi

Journal of Electrochemistry

Detection of target analytes at low concentrations is significant in various fields, including pharmaceuticals, healthcare, and environmental protection. Theophylline (TP), a natural alkaloid used as a bronchodilator to treat respiratory disorders such as asthma, bronchitis, and emphysema, has a narrow therapeutic window with a safe plasma concentration ranging from 55.5–111.0 μmol·L^–1 in adults. Accurate monitoring of TP levels is essential because too low or too high can cause serious side effects. In this regard, non-enzymatic electrochemical sensors offer a practical solution with rapidity, portability, and high sensitivity. This article aims to provide a comprehensive review of the recent developments …

Study On Dopamine Electrochemical Sensing Based On Au@Mos2, Ning An, Ni Su, Xin-Ran Li, Jian-Yu Liu, Qi-Yan Wang

Journal of Electrochemistry

Dopamine (DA) is a vital neurotransmitter, and accurate detection of its concentration is critical for both clinical diagnostics and neuroscience research. Due to its electrochemical activity, DA is commonly detected using electrochemical methods, which are favored for their simplicity, fast response time, and suitability for in vivo analysis. In this work, a highly sensitive DA electrochemical sensor was developed using an Au@MoS₂ composite, created by modifying molybdenum disulfide (MoS₂) nanosheets with gold nanoparticles through HAuCl₄ reduction, and it was aimed at enhancing DA adsorption and improving detection performance. Scanning Electron Microscopy (SEM), transmission electron microscopy (TEM), …

In-Situ Electrodeposition Of Feco-Mof On Au Ultramicroelectrode For Highly Sensitive Detection Of Epinephrine, Yan Chen, Shang Jian, Si-Yu Wan, Xiao-Tong Cui, Zhong-Gang Liu, Zheng Guo

Journal of Electrochemistry

Metal-organic framework (MOF) nanostructures have emerged as a prominent class of materials in the advancement of electrochemical sensors. The rational design of bimetallic MOF-functionalized microelectrode is of importance for improving the electrochemical performance but still in great challenge. In this work, the bimetallic FeCo-MOF nanostructures were assembled onto a gold disk ultramicroelectrode (Au UME, 5.2 μm in diameter) via an in-situ electrodeposition method, which enhanced the sensitive detection of epinephrine (EP). The in-situ electrodeposited FeCo-MOF exhibited a characteristic nanoflower-like morphology and was uniformly dispersed on the Au UME. The FeCo-MOF/Au UME demonstrated excellent electrochemical performance on the detection of EP …

Preserve Your Hma Pavements From The Start, Tim Zahrn, Andrew Eicher

Purdue Road School

This presentation will review sustainable preservation treatments and their application timeline to extend the life of asphalt pavement. We will discuss how pre-preservation treatments like a void reducing asphalt membrane, early-life preservation treatments such as rapid penetrating emulsion, and topical rejuvenators can reduce future maintenance and delay reconstruction. We will also look at mid-life treatments, such as micro-surfacing, fit into a preventative maintenance preservation plan. And finally cover end of life cold pavement recycling alternatives.

Intelligent Turning Cyber-Physical Systems Modeling Using Sysml, Prithbey Raj Dey, David Lee Enke, Mario F. Buchely

Engineering Management and Systems Engineering Faculty Research & Creative Works

Cyber-Physical Systems (CPS) support industrial automation that incorporates people, hardware, signal, computation, and control using networking to achieve desired results. The complex automated CPS design demands a standard and comprehensive approach to appropriately identify the system requirements, define the architecture, and model the relationships among the software and hardware components. Systems Modeling Language (SysML) provides the capability for a comprehensive modeling to capture the desired design requirements in the systems architecture. SysML enables performance estimation of the model by analyzing constraints while identifying interactions among the components through various behavioral diagrams. In this paper, SysML is applied to the design …

Improvement Of Microcracking And Mechanical Properties Of Tungsten Fabricated Via Laser Powder Bed Fusion Through Alloying With Reactive Secondary Constituents, William S. Mockel

Theses and Dissertations

Tungsten (W), a Group VI transition metal, possesses a number of advantageous properties, most notably its impressive mechanical performance at extreme temperatures. While tungsten's nature render traditional manufacturing methods difficult, additive manufacturing through laser powder bed fusion (LPBF) presents a promising avenue for fabricating tungsten components. However, the material’s high ductile-to-brittle transition temperature combined with the embrittling effect of impurities mean that the residual stresses imparted by LPBF result in microcracking in tungsten, degrading its usefulness. This study sought to improve the characteristics of LPBF-W through the removal of embrittling oxygen content via alloying with low concentrations of reactive elements, …

Mechanical Response Of Triply Periodic Minimal Surface Gyroid Structures Under Combined Loading, Jay B. Patel

Theses and Dissertations

This work explored combined tensile and torsional loads applied to additively manufactured Inconel 718 specimens employing Triply Periodic Minimal Surface (TPMS) structures. The gyroid TPMS unit cell was selected with two variations of cylindrical cell maps, a rectangular cell map, and a spherical cell map. All four variants were tested in an axial-torsion test frame at room temperature using equal parts of vertical and angular displacement control until failure. The combined loading in these tests utilized tension and torsion. The data from the tests were compared to finite element analysis (FEA) models to visualize when yielding was predicted. Finally, the …

Fatigue Behavior Of Two Advanced C/Sic Composites At 1200°C In Air, Conner A. Adams

Theses and Dissertations

High-temperature tension-tension fatigue behavior of two advanced carbon/silicon carbide (C/SiC) ceramic matrix composites (CMCs) was investigated. Both composites were reinforced with T300 carbon fibers. Laminated carbon fiber preforms consisted of 24 plies of plain weave fabric in a 0/90 layup. The first composite, C/CVI-SiC, was processed by chemical vapor infiltration (CVI) of SiC into the fiber preform. Prior to the CVI process, the fiber preforms were coated with a duplex pyrolytic carbon and boron carbide fiber coating to create a weak fiber- matrix interphase. The second composite, C/HYPR-SiC, was also processed via CVI, but had an oxidation inhibited matrix comprising …

Fatigue Behavior Of An Advanced Sic/Sic Composite With An Array Of Small Cooling Holes At 1200°C, Tess K. Panchyshyn

Theses and Dissertations

Tension-tension fatigue behavior of an advanced melt-infiltrated (MI) silicon carbide/silicon carbide (SiC/SiC) composite was evaluated, and basic tensile properties measured, at 1200°C in laboratory air.  The composite consists of a melt-infiltrated SiC matrix reinforced with laminated Hi-Nicalon Type-S fibers woven in a 5-harness satin weave. The Hi-Nicalon-S fiber preforms were coated with a boron nitride (BN) fiber coating by chemical vapor infiltration (CVI). The melt-infiltrated matrix was consolidated by combining CVI-SiC with SiC particulate slurry and molten silicon infiltration. The finished ceramic matrix composite (CMC) had a fiber volume fraction of 33%. Additionally, the effect of multiple small holes on …

On The Exploration Of Crystallographic Anisotropy And Defects In Shock Loading Using Molecular Dynamics, Benjamin P. Helman

Theses and Dissertations

The impact of crystallographic orientation, grain boundaries, and vacancies on the shock behavior of aluminum was investigated using molecular dynamics simulations. Shock loading in the [001], [011], and [111] directions was explored, revealing anisotropic behavior in shock speed, melting, dislocation density, and unique phase changes. The Hugoniot elastic limit in the [100], [110], and [111] directions was calculated as 23.2 GPa, 24 GPa, and 18.4 GPa respectively. These results were found to be an order of magnitude larger than the compressive yield strength computed at equilibrium. Additionally, metastable melting in the [011] and [111] directions occurred roughly 1000 K below …

Discovering Design Requirements For Next Generation Arctic Tension Fabric Shelters, Mark W. Mcveigh

Theses and Dissertations

Military operations to remote Arctic regions require large-span temporary shelters to house tactical aircraft and provide heated maintained spaces. However, the current System-50 Large Area Maintenance Shelters used by the United States Air Force and Department of Defense are inadequate for Arctic deployments. These shelters lack durability against extreme subzero temperatures, heavy snow accumulation, and high wind speeds. They also fail to address critical Arctic-specific design challenges including permafrost protection, foundation disruption caused by frost heaves, and efficient heating as a result of their inadequate thermal resistance properties. This research analyzed 20 years of climatological data from 8,399 weather observation …

Thermophysical Properties Of Aqueous Amine Salts For Closed Air Cabin Revitalization, Mahmud R. Yusuf, Isabela Flores, Ben Hines, Li Hua Zhang, Seth Christa, Brooks D. Rabideau, Kevin West, Breanna Dobyns, James Davis

Shelby Hall Graduate Research Forum Posters

Carbon dioxide (CO2) capture plays a crucial role in closed cabin air revitalization, however current CO2 capture technologies pose several issues. Traditional amine solutions, such as monoethanolamine, are commonly used in CO2 capture on the International Space Station but face drawbacks including high volatility, thermal degradation, and unpleasant odor. To overcome these challenges, amine salt solutions have emerged as promising alternatives. Amine salt solutions have reduced environmental impact, lower corrosion potential, and improved CO2 loading capacity, making them a more efficient and sustainable replacement. Knowing these physical properties are critical for modeling and optimizing a scrubbing process that employs these …

Treating Ground Water For Agricultural And Individual Consumption, Gabby Miller, Bronson Scott, Michael Clawson

Biomedical Engineering

This project, conducted in collaboration with Cal Poly seniors and Da Vinci High School students, aims to develop a solar-powered groundwater purification system. This system is designed to provide clean water for agricultural use and individual consumption, addressing the growing concerns of groundwater contamination and accessibility needs. The final prototype integrates a gravity filtration system combined with chemical purification, utilizing aluminum sulfate and chlorine to remove particulates, bacteria, and organic compounds.

The research phase involved an extensive review of groundwater contamination issues, existing filtration technologies, and market analysis. Key design constraints included cost-effectiveness, ease of maintenance, and minimal energy consumption, …