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Articles 181 - 210 of 1714

Full-Text Articles in Mechanical Engineering

Dust Analyses In Ventilation Ducts, Karolina Vyhlidalova, Petr Vlček, Olga Rubinová, Jiří Bernard Apr 2025

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 Apr 2025

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, …


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

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 …


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 Mar 2025

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 …


Intelligent Turning Cyber-Physical Systems Modeling Using Sysml, Prithbey Raj Dey, David Lee Enke, Mario F. Buchely Mar 2025

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 Mar 2025

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, …


Treating Ground Water For Agricultural And Individual Consumption, Gabby Miller, Bronson Scott, Michael Clawson Mar 2025

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, …


Heavy Metals Pollution In Roadside Ecosystems, Lilian Matafu Jan 2025

Heavy Metals Pollution In Roadside Ecosystems, Lilian Matafu

Tanzania Journal of Engineering and Technology (TJET)

Heavy metals refer to metallic elements that are characterized by having a relatively high density and they are toxic or poisonous even at low concentration. They are environmental pollutant owing to toxicity and longevity in atmosphere and ability to accumulate in living things via bioaccumulation. They tend to enter in different system such as food chain. Analyses of water, soil sediment and the surrounding growing plants (Cynodon dactylon and Cyperus species) for selected heavy metals (Cd, Pb, Zn and Cu) were conducted on a roadside pond located at Boko MSB, Dar es Salaam. Pond water, soil sediments and plant samples …


Assessment Of Wind Speed Characteristics And Available Wind Power Potential For Electricity Generation In Tanzania, Mwingereza John Kumwenda Jan 2025

Assessment Of Wind Speed Characteristics And Available Wind Power Potential For Electricity Generation In Tanzania, Mwingereza John Kumwenda

Tanzania Journal of Engineering and Technology (TJET)

The energy demand and its associated crises are attracting significant attention due to population increase and economic growth especially in developing countries. Fossil fuel-based energy source stand as a prominent anthropogenic resource but they are accompanied with increased carbon emissions and heightened environmental concerns. Renewable energy sources such as wind energy can offers a lot of potential for sustainable growth in the energy sector of developing nations like Tanzania. Thus, this work investigated wind speed characteristics and available wind power potential in six selected regions in Tanzania with different topographical features for future electricity generation. The data of the wind …


Thermo-Rheological And Tribological Properties Of Low- And High-Oleic Vegetable Oils As Sustainable Bio-Based Lubricants, Abiodun Saka, Tobechukwu K. Abor, Anthony C. Okafor, Monday U. Okoronkwo Jan 2025

Thermo-Rheological And Tribological Properties Of Low- And High-Oleic Vegetable Oils As Sustainable Bio-Based Lubricants, Abiodun Saka, Tobechukwu K. Abor, Anthony C. Okafor, Monday U. Okoronkwo

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Vegetable oil-based lubricants have attracted increased research attention in recent decades as sustainable alternatives to conventional petroleum-based lubricants in metal machining. However, more studies are required to fully elucidate the thermo-rheological and tribological properties. This study presents an investigation of the thermo-rheological and tribological properties of different vegetable oils, including low- and high-oleic soybean oil, high-oleic sunflower, safflower, and canola oils. The lubricity, and evolution of viscosity and thermodynamic properties as a function of temperature were investigated to obtain important parameters including the viscosity index, flow behavior index, flow activation energy, specific heat capacity, thermal conductivity, coefficient of friction, contact …


Development Of Microfluidic Device To Monitor The Contamination In Drinking Water Using Impedance Spectroscopy, Pornpipat Oupchan Jan 2025

Development Of Microfluidic Device To Monitor The Contamination In Drinking Water Using Impedance Spectroscopy, Pornpipat Oupchan

Chulalongkorn University Theses and Dissertations (Chula ETD)

Microplastic contamination is a growing concern, as microplastics have been found in brain tissue and can enter the body through consumption. The objective of this research is to develop a microfluidic device to monitor microplastic particles by using electrical impedance spectroscopy principles. The device operates based on a flow-through principle. The configuration of electrode consists of copper-based cylindrical electrode with diameter of 300 micrometer and a center-to-center spacing of 2000 micrometer. The electrodes are designed to be replaceable. The microchannel has a rectangular cross-section with a width of 2000 micrometer and a height of 1000 micrometer. The microfluidic device was …


การทำความเย็นส่วนบุคคลโดยใช้วัสดุเปลี่ยนสถานะสำหรับบุคลากรที่สวมใส่ชุดป้องกันการติดเชื้อส่วนบุคคล, พรพุทธ วิสุทธิวัชรกุล Jan 2025

การทำความเย็นส่วนบุคคลโดยใช้วัสดุเปลี่ยนสถานะสำหรับบุคลากรที่สวมใส่ชุดป้องกันการติดเชื้อส่วนบุคคล, พรพุทธ วิสุทธิวัชรกุล

Chulalongkorn University Theses and Dissertations (Chula ETD)

ชุดป้องกันส่วนบุคคล (PPE) เป็นอุปกรณ์สำคัญที่ช่วยลดความเสี่ยงในการติดเชื้อของบุคลากรทางการแพทย์ อย่างไรก็ตาม การสวม PPE เป็นเวลานาน โดยเฉพาะในสภาพอากาศร้อนและชื้นอย่างประเทศไทย มักนำไปสู่การกักเก็บความร้อนในร่างกาย การระบายความร้อนลดลง และเกิดความไม่สบาย ความเหนื่อยล้า รวมถึงภาวะเครียดจากความร้อน งานวิจัยนี้จึงได้พัฒนาแบบจำลองชีวความร้อนอย่างง่าย (simplified bioheat model) โดยอ้างอิงโครงสร้างแบบจำลองแบบ passive ของ Fiala และเสริมด้วยการตอบสนองทางสรีรวิทยาแบบ active ที่จำเป็น เพื่อใช้ทำนายอุณหภูมิของร่างกายและประเมินความสบายทางความร้อนเมื่อสวม PPE ร่วมกับการระบายความร้อนด้วยวัสดุเปลี่ยนสถานะ (Phase Change Material: PCM) ผลการตรวจสอบความถูกต้องเทียบกับแบบจำลองอ้างอิงของ Fiala แสดงให้เห็นว่าแบบจำลองที่พัฒนาขึ้นมีความแม่นยำดี โดยมีความคลาดเคลื่อนของอุณหภูมิอยู่ภายใน ±0.2°C นอกจากนี้ผลการจำลองยังพบว่า PCM สามารถลดความเครียดจากความร้อนและเพิ่มความสบายทางความร้อนอย่างมีนัยสำคัญในช่วง 60 นาทีแรกของการทำงาน แม้ว่าประสิทธิภาพจะลดลงเมื่อ PCM หลอมละลายเต็มที่ก็ตาม ข้อจำกัดของงานวิจัยนี้ คือ แบบจำลองตั้งอยู่บนสมมติฐานของสภาวะอากาศร้อน (เริ่มต้นที่ 30°C) ทำให้ยังไม่สามารถแทนสภาวะอากาศเย็นได้อย่างสมบูรณ์ อีกทั้งไม่ได้พิจารณาการตอบสนองทางสรีรวิทยาระยะยาว เช่น ภาวะขาดน้ำ ความเหนื่อยล้า หรือความเครียดเชิงกลจากน้ำหนัก PCM ที่เพิ่มขึ้น ถึงแม้จะมีข้อจำกัดดังกล่าว แบบจำลองนี้ยังคงสามารถทำนายอุณหภูมิร่างกายและค่าความรู้สึกทางความร้อนแบบพลวัต (DTS) ได้อย่างมีประสิทธิภาพก่อนการใช้งานจริง จึงสามารถนำไปใช้เป็นเครื่องมือช่วยวางแผนระยะเวลาการทำงานที่ปลอดภัย และช่วยกำหนดปริมาณ รวมถึงตำแหน่งการติดตั้ง PCM ที่เหมาะสม ผลลัพธ์จากงานวิจัยนี้สามารถเป็นฐานข้อมูลสำคัญสำหรับการออกแบบชุด PPE ที่ปลอดภัย และช่วยลดภาระความร้อนสำหรับบุคลากรทางการแพทย์ในสภาพแวดล้อมร้อนชื้นได้ดียิ่งขึ้น


Microwave-Assisted Reduction Of Critical Metal Oxides From E-Waste Mixture, Kurundu Shavinka Jayasekera Jan 2025

Microwave-Assisted Reduction Of Critical Metal Oxides From E-Waste Mixture, Kurundu Shavinka Jayasekera

Graduate Theses, Dissertations, and Problem Reports (ETD)

The efficient recovery of critical metals such as tantalum (Ta), manganese (Mn), gallium (Ga), and indium (In) from electronic waste (e-waste) is essential for resource sustainability and environmental protection. This research uses microwave-assisted treatment to investigate the carbothermal reduction of these four specific metals from their oxides in a simulated e-waste mixture, with carbon black serving as both a microwave coupling and reduction agent. Microwave processing is used specifically because it offers a rapid and energy-efficient alternative to conventional thermal methods, with the benefits of intrinsic heating and selective heating of materials. The first experiments centered on understanding the effects …


Controlling Nitrogen Pickup During Induction Melting Of Ultrahigh-Strength Cr-Ni-Mo-V Steels, Kingsley T. Amatanweze, Viraj A. Athavale, Mario F. Buchely, Laura N. Bartlett, Ronald J. O'Malley, Daniel M. Field Jan 2025

Controlling Nitrogen Pickup During Induction Melting Of Ultrahigh-Strength Cr-Ni-Mo-V Steels, Kingsley T. Amatanweze, Viraj A. Athavale, Mario F. Buchely, Laura N. Bartlett, Ronald J. O'Malley, Daniel M. Field

Materials Science and Engineering Faculty Research & Creative Works

Nitrogen pickup during air induction melting can result in porosity and a loss of fracture toughness in ultrahigh-strength quenched and tempered steel castings. Nitrogen atoms are easily adsorbed into liquid steel upon exposure to the air, and argon shrouding alone has limited effectiveness. Previous studies have shown that proper charge sequencing and maintaining a high amount of dissolved oxygen in the melt prior to tapping and deoxidation can limit nitrogen pickup in the melt. In the current study, the effect of melt practice and charging procedure on nitrogen pickup was studied as a function of hold time in a series …


Parametric Analysis Of Water Jet Descaling Efficiency Of Reheated Continuously Cast Thin Slab, Tochukwu P. Ojiako, Mario F. Buchely, Simon Lekakh, Ronald J. O'Malley, Richard Osei, Taha Tayebali Jan 2025

Parametric Analysis Of Water Jet Descaling Efficiency Of Reheated Continuously Cast Thin Slab, Tochukwu P. Ojiako, Mario F. Buchely, Simon Lekakh, Ronald J. O'Malley, Richard Osei, Taha Tayebali

Materials Science and Engineering Faculty Research & Creative Works

Efficient oxide scale removal is critical for maintaining surface quality and process efficiency in steel manufacturing. This study optimizes water jet descaling by evaluating the performance of flat and rotary jet nozzles under varying process parameters. Using a combined approach of experimental analysis and computational fluid dynamics, it investigates the influence of pressure (138–275 bar), lead angle (0°, 15°, 25°), working distance (50–100 mm), and spray angle (15°–25°) on descaling efficiency. Findings indicate that flat jet nozzles achieve superior performance at short working distances due to concentrated impact forces, while rotary jet nozzles sustain efficiency over extended distances through dynamic …


Effect Of Gating Design On Filling And Inclusion Control In An Al-Killed Cr-Mo-Ni Steel, Kingsley T. Amatanweze, Koushik Balasubramanian, Soumava Chakraborty, Viraj A. Athavale, Mario F. Buchely, Laura N. Bartlett, Ronald J. O'Malley, Daniel M. Field, Krista R. Limmer, Katherine M. Sebeck Jan 2025

Effect Of Gating Design On Filling And Inclusion Control In An Al-Killed Cr-Mo-Ni Steel, Kingsley T. Amatanweze, Koushik Balasubramanian, Soumava Chakraborty, Viraj A. Athavale, Mario F. Buchely, Laura N. Bartlett, Ronald J. O'Malley, Daniel M. Field, Krista R. Limmer, Katherine M. Sebeck

Materials Science and Engineering Faculty Research & Creative Works

The effect of gating system design on the inclusion population and size distribution in an aluminum-killed low-alloy advanced high strength steel casting was studied. A mold with four different gating systems: pressurized and non-pressurized with side risers, naturally pressurized with a side riser, and naturally pressurized with a top riser, was designed using computational fluid dynamics and solidification software. The design allowed inclusion populations in castings produced with each gating system to be compared during the same pouring event. Samples taken from different positions just below the top surface of each casting were analyzed using an SEM/EDS system with automated …


Cochlear Electrode Insertion Training Model, Sarah Powell, Kaelyn E. Kraley, Nathan J. Smith Jan 2025

Cochlear Electrode Insertion Training Model, Sarah Powell, Kaelyn E. Kraley, Nathan J. Smith

Williams Honors College, Honors Research Projects

Cochlear implant surgery is a delicate procedure performed by Otolaryngologists (ENTs) to implant an electronic device into the inner ear to provide a sense of sound for people who are profoundly deaf or hard of hearing. The current practices of training involve cadavers and 3D-printed models. Cadavers are commonly used but are expensive, single-use, and do not provide visual and haptic feedback, which are essential for medical students. 3D printed models are less commonly used and are hard to fabricate and not as realistic. If medical students are not properly trained for this delicate procedure, then risks are significantly increased …


Design And Development Of A Rapid Tensile Quench Rig, Tyler Jewell, Justin Naylor Jan 2025

Design And Development Of A Rapid Tensile Quench Rig, Tyler Jewell, Justin Naylor

Williams Honors College, Honors Research Projects

This report outlines the design process and implantation of a tensile quenching rig that incorporated forced convection and a frequency generator. When any metal is quenched, a vapor barrier forms around it. When this happens, it limits the heat flux that may occur until the barrier turns into just nucleate boiling. The vapor barrier acts as an insulator and causes the heat flux to fluctuate, causing uneven hardening which would limit the use of some materials. To combat this effect, we are trying to use forced convection, and something new, which is adding high frequency waves into the quenching process. …


Characterization Of Properties And Defects Of Alternative Matrix Materials For 3d Printed Continuous Carbon Fiber Reinforced Composites, Noah Darren Osborne Jan 2025

Characterization Of Properties And Defects Of Alternative Matrix Materials For 3d Printed Continuous Carbon Fiber Reinforced Composites, Noah Darren Osborne

Graduate Theses, Dissertations, and Problem Reports (ETD)

Additive manufacturing, commonly known as 3D printing, has the potential to transform the production of end-use parts by facilitating the creation of complex shaped, low-volume components that are expensive to manufacture using traditional methods. However, thermoplastic polymer matrices currently utilized in 3D printing of carbon fiber composites, often lack the mechanical properties needed for aerospace applications. To address this issue, researchers have developed fiber-reinforced 3D-printed composites using an innovative two-step process which involves printing 3D preforms using fused deposition modeling, followed by compression molding. However, most previous work involves the use of nylon-based polymer matrices while there are a number …


Pulsed Arc Additive Manufacturing Of A Functionally Graded Er2209 Duplex Stainless Steel And Hsla-100 Structure: Morphology, Characterization, And Mechanical Performance, Stevens G. Hill Jr Jan 2025

Pulsed Arc Additive Manufacturing Of A Functionally Graded Er2209 Duplex Stainless Steel And Hsla-100 Structure: Morphology, Characterization, And Mechanical Performance, Stevens G. Hill Jr

College of Graduate Studies: Theses & Dissertations

Wire arc additive manufacturing is a process well suited to the efficient production of large structures. Duplex stainless steel exhibits high corrosion resistance and good strength which can be highly beneficial for industrial use. However, its use is limited due to its cost and complexity in controlling microstructure to achieve desired properties. In many cases, it can be highly beneficial to manufacture a component which uses specialty steel grades such as duplex stainless steel only where necessary, and utilizes more affordable, commonly available steels for reinforcement or bulk structural support. A functionally graded material satisfies these requirements by providing a …


Identification Of Corrosion Damage, Vibration, And Loose Conections In Aircraft Data Transmission Lines Using Reflected And Transmitted Signals; Formulation Of Vegetable Oil-Based Nanofluids As Cutting Fluids For Mql Machining, Saidanvardzhon Valiev Jan 2025

Identification Of Corrosion Damage, Vibration, And Loose Conections In Aircraft Data Transmission Lines Using Reflected And Transmitted Signals; Formulation Of Vegetable Oil-Based Nanofluids As Cutting Fluids For Mql Machining, Saidanvardzhon Valiev

Doctoral Dissertations

This research presents a novel Frequency Domain Transmitometry (FDT) method that uses transmitted signals (S21) to detect and characterize aircraft data transmission lines (ADTL) corrosion damage without additional reflectometry circuitry. Corrosion experiments were conducted according to ASTM G85-A5 over 14 weeks. Combined FDT and reflected signals (S11) analyses revealed distinct three-peak signatures associated with damage and corrosion. The square root of the Area Under the Curve (AUC) of the FDT damage peak and the Full Width at Three-Quarter Maximum (FW3QM) of the S11 damage peak is correlated with corrosion propagation depth and width. S11 signals were further used for vibration …


Optimization Of Tps Films Using An Adaptive Design Of Experiments Approach In A Bayesian Optimization Framework, Theresa Marks, Gracie White, Scott Lohman, Mayank Malhotra Dec 2024

Optimization Of Tps Films Using An Adaptive Design Of Experiments Approach In A Bayesian Optimization Framework, Theresa Marks, Gracie White, Scott Lohman, Mayank Malhotra

The Journal of Purdue Undergraduate Research

Plastic pollution, amounting to 12 million tons annually, necessitates sustainable alternatives to single-use plastics. Compostable thermoplastic starch (TPS) films show promise but lack strength and durability compared to traditional plastics. This study employs an adaptive design of experiments (DoE) approach to enhance TPS films by optimizing testing points. The research focuses on varying concentrations of plasticizers (acetic acid and glycerol) in a water and potato starch mixture, aiming to identify the optimal ratio maximizing tensile strength and % elongation at break. Gaussian process regression (GPR) with uncertainty estimation and Bayesian optimization (BO) utilizing an acquisition function (AF) are employed. The …


Mae Enewsbrief July-Sept 2024, Department Of Mechanical And Aerospce Engineering, Michigan Technological University Dec 2024

Mae Enewsbrief July-Sept 2024, Department Of Mechanical And Aerospce Engineering, Michigan Technological University

Department of Mechanical and Aerospace Engineering eNewsBrief

No abstract provided.


Influence Of Hygrothermal Conditions Of The Bistability Of Asymmetric Carbon Fiber Laminate Composites, Celia Hill Dec 2024

Influence Of Hygrothermal Conditions Of The Bistability Of Asymmetric Carbon Fiber Laminate Composites, Celia Hill

All Theses

Carbon fiber-reinforced polymer (CFRP) laminates have widespread use in many industries because of their exceptional strength-to-weight ratio. Carbon fiber laminates following an asymmetric layup orientation can exhibit bistability meaning the laminate can exist at two stable geometric configurations. The morphing characteristics of bistable CRFP has a growing level of interest because of its potential in various applications including space aircraft structures for easy repair, automotive structures for energy dissipation and ergonomics, robotics for flexible motion and energy harvesting. Existing research shows that both moisture and temperature affect the material properties and behavior of CFRP laminates, however, the influence of moisture …


Thermal Conductivity Characterization Of High Oleic Vegetable Oils Based Hybrid Nanofluids Formulated Using Gnp, Tio2, Mos2, Al2o3 Nanoparticles For Mql Machining, Anthony Chukwujekwu Okafor, Tobechukwu Kingsley Abor, Saidanvar Esanjonovich Valiev, Ignatius Echezona Ekengwu, Abiodun Saka, Monday Uchenna Okoronkwo Dec 2024

Thermal Conductivity Characterization Of High Oleic Vegetable Oils Based Hybrid Nanofluids Formulated Using Gnp, Tio2, Mos2, Al2o3 Nanoparticles For Mql Machining, Anthony Chukwujekwu Okafor, Tobechukwu Kingsley Abor, Saidanvar Esanjonovich Valiev, Ignatius Echezona Ekengwu, Abiodun Saka, Monday Uchenna Okoronkwo

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper presents the results of thermal conductivity characterization of six high oleic soybean oil (HOSO) and four high oleic canola oil (HOCO)-based hybrid nanofluids formulated with four types of nanoparticles (Graphene nanoplatelet (xGnP), TiO2, MoS2, and Al2O3) at nanoparticles wt.% concentration from 1 % to 7 % in 1 % increment using the two-step method for use in MQL machining of difficult-to-cut metals. Thermal conductivity of the formulated hybrid nanofluids were measured using Thermtest Transient Hot Wire Liquid Thermal Conductivity Meter at temperatures from 25 °C to 75 °C in increment of 10 °C. Obtained results showed that thermal …


Elucidating The Effect Of Milled Glass And Graphite Fiber On The Quasi-Static Properties Of Vinyl Ester Resin Composites, Sarahi Mendivil Dec 2024

Elucidating The Effect Of Milled Glass And Graphite Fiber On The Quasi-Static Properties Of Vinyl Ester Resin Composites, Sarahi Mendivil

Open Access Theses & Dissertations

Composite materials can be tailored to various applications, making them one of the most conventional materials. Their ability to enhance desired characteristics enables higher strength while maintaining light weight. However, understanding defects and manufacturing limitations is crucial for optimizing their fabrication processes. This paper focuses on the manufacturing processes of open molding with controlled variations to establish an optimal technique aimed at minimizing defects, such as bubble formation where the focus is on mitigating defects and ensuring uniform dispersion of fiber in fiber-reinforced composites. After refining the manufacturing process, composites with varying resin-to-fiber concentration ratios were manufactured using glass and …


Ultra-High Temperature Ceramics: Materials, Manufacturing, And Machine Development, Joseph Matthew Munoz Dec 2024

Ultra-High Temperature Ceramics: Materials, Manufacturing, And Machine Development, Joseph Matthew Munoz

Open Access Theses & Dissertations

This research aimed to advance the 3D printing of ultra-high-temperature ceramic matrix composites (UHTCMCs) and develop a custom Direct Ink Writing (DIW) system with multimaterial and in-line mixing capabilities. The study first focused on creating ZrB₂–SiC composites reinforced with aligned silicon carbide fibers (SiCf) using paste extrusion. By formulating suspensions with a preceramic polymer (SMP-10), ZrB₂, and SiCf, the study assessed how fiber alignment influenced key properties such as thermal and electrical conductivity and mechanical strength. Green curing and pyrolysis transformed the printed parts into UHTCMCs, with results showing substantial improvements in thermal conductivity—nearly double that of non-aligned parts—and a …


Greek Key-Inspired Fractal Metamaterials With Enhanced Flexibility And Energy Absorption., Zhennan Zhang Dec 2024

Greek Key-Inspired Fractal Metamaterials With Enhanced Flexibility And Energy Absorption., Zhennan Zhang

Electronic Theses and Dissertations

Architected materials with intricate three-dimensional (3D) geometries offer unique properties and functionalities but face challenges in manufacturing costs and complexity. This research explores the integration of simple 2D Greek Key-inspired lattices into fractal designs to achieve exceptional mechanical performance. Using 3D printing and kerfing, these fractal structures demonstrate enhanced flexibility and energy absorption capabilities. Through three-point bending and in-plane tensile tests, the 2D fractal lattices exhibited a 600-fold reduction in bending force and a tensile stretch capacity of up to 520%, significantly outperforming brittle parent materials. Out-of-plane compression tests revealed a five-fold increase in energy absorption compared to honeycomb structures, …


Synthesis And In Vitro Testing Of Mg-6zn-Xhap Biocomposites From Beef Bone As Biodegradable Bone Implant Material, Jojor Lamsihar Manalu, Francisca Tjhay, Theodora Kristoforus, Sovian Aritonang Nov 2024

Synthesis And In Vitro Testing Of Mg-6zn-Xhap Biocomposites From Beef Bone As Biodegradable Bone Implant Material, Jojor Lamsihar Manalu, Francisca Tjhay, Theodora Kristoforus, Sovian Aritonang

Journal of Mechanical Engineering Science and Technology (JMEST)

This study aimed to develop biodegradable Mg-6Zn hydroxyapatite (Mg-6Zn HAp) biocomposites for potential use in bone replacement applications. The hydroxyapatite (HAp) powders, sourced from cow bone, were synthesized through an eco-friendly and cost-effective process, leveraging bioresources for material sustainability. The Mg-6Zn and HAp powders were mechanically mixed through ball milling for six hours to ensure homogeneity. The resultant powder mixture was then subjected to isostatic pressing at a high pressure of 570 MPa, forming a dense coin-shaped composite with a 1.5 cm diameter. This coin was consolidated in a capsule furnace at elevated temperatures for one hour to enhance material …


Analysis Of Tidal Energy Potential In The Merauke Papua River Waters Indonesia, Peter Sahupala, Daniel Parenden Nov 2024

Analysis Of Tidal Energy Potential In The Merauke Papua River Waters Indonesia, Peter Sahupala, Daniel Parenden

Journal of Mechanical Engineering Science and Technology (JMEST)

The purpose of this study is as a source of information to study the potential of tidal energy at the estuary of the Maro River in the waters of Merauke Regency. This study uses a quantitative method, while the method for determining the location of the study used is the purposive sampling method where the data collection point is right at the end of the estuary of the Maro River because it faces directly onto the Arafura Sea. Tide data for 5 months, namely September 1, 2023 to January 31, 2024 with a pool area of 1,260,000 m2, with the …