Engineering Commons^™

Stability Of Ruddlesden-Popper Phase Lanthanum Nickelate As Air Electrode For Reversible Solid Oxide Cells, Daniel De Lorenzo Moreira

Graduate Theses, Dissertations, and Problem Reports (ETD)

This thesis studied the long-term stability of Ruddlesden-Popper phase Lanthanum Nickelate under operating conditions as the air electrode for Reversible Solid Oxide Cells (R-SOC). Renewable energies have gone through increase in popularity throughout the last decades, mainly due to the consequences of the rapid population growth in the world. These new energies have been pointed as the rightful successor of fossil fuel energies in order to decrease the environmental impact of our day-to-day life. Solid Oxide Fuel Cells as well as Solid Oxide Electrolysis Cells are believed to be the key to stabilizing the energy supply when environmental conditions are …

Multimaterial, Core-Shell Direct Ink Writing Of Flexible Strain Sensors For Pneumatically-Actuated Soft Robotic Hinge Joints, John Michael Burke

Graduate Theses, Dissertations, and Problem Reports (ETD)

Direct ink writing (DIW) provides for an expansive material library and the ability to print multiple materials with tailored functionalities in a controllable and single-step process. Particularly beneficial is the net shape printing under ambient conditions of a wide range of materials normally incompatible with one another. Coaxial DIW is a 3D printing technique that allows for two dissimilar inks to be extruded simultaneously in a co-flow manner. In this work, custom-designed coaxial nozzles were 3D-printed using a stereolithography printer. Composite inks comprised of thermoplastic polyurethane and silver were developed and studied. The coaxial nozzles were then used to co-extrude …

Biologically – Plausible Load Feedback From Dynamically Scaled Robotic Model Insect Legs, William Zyhowski

Graduate Theses, Dissertations, and Problem Reports (ETD)

Researchers have been studying the mechanisms underlying animal motor control for many years using computational models and biomimetic robots. Since testing some theories in animals can be challenging, this approach can enable unique contributions to the field. An example of a system that benefits from this modeling and robotics approach is the campaniform sensillum (CS), a kind of sensory organ used to detect the loads exerted on an insect's legs. The CS on the leg are found in groups on high-stress areas of the exoskeleton and have a major influence on the adaptation of walking behavior. The challenge for studying …

Design And Manufacture Of An Aerodynamic Body That Meets Scaling Law Requirements And Survives Severe G-Load Environment For Free-Flight Testing, Anthony R. Gonzalez

Graduate Theses, Dissertations, and Problem Reports (ETD)

Design and Manufacture of an Aerodynamic Body that Meets Scaling Law Requirements and Survives Severe G-load Environment for Free-Flight Testing

Anthony Gonzalez

Developing scale models to test functionality and ascertain aerodynamic properties is critical before manufacturing full-size products. Through dimensional analysis and similitude, engineers create scale models to test any parameter of interest. This research aims to design a scale model of an aerodynamic body for repeated free-flight testing. The Froude number is the dominant scale model law used to determine the geometric, mass, and inertia scaling laws. A critical requirement for this research is that the model should be …

A Semantic Web Approach To Fault Tolerant Autonomous Manufacturing, Fadi El Kalach, Ruwan Wickramarachchi, Ramy Harik, Amit Sheth

Publications

The next phase of manufacturing is centered on making the switch from traditional automated to autonomous systems. Future factories are required to be agile, allowing for more customized production, and resistance to disturbances. Such production lines would be able to reallocate resources as needed and minimize downtime while keeping up with market demands. These systems must be capable of complex decision-making based on parameters such as machine status, sensory/IoT data, and inspection results. Current manufacturing lines lack this complex capability and instead focus on low-level decision-making on the machine level without utilizing the generated data to its full extent. This …

A Primal Treatise Of Constant-Force Compliant Segment And Mechanism Design With Applications, Vamsi Lodagala

Doctoral Dissertations

"The evolution of compliant mechanisms propelled the development of constant-force mechanisms (CFMs) for various applications because of their unique characteristics. Many research endeavors have presented different techniques that often involve some optimization to design the CFMs. However, the mechanics of the generation of constant force at the elemental level is not well understood. This research effort theorizes and validates that simple, compliant segment with different boundary conditions, subjected to axial loading, produce near-constant force without the need for design optimization. Analytical models are developed based on the pseudo-rigid-body model (PRBM) concept to predict their force-displacement behavior, and to establish that …

Unsteady Flow Behaviors Generated By Three-Dimensional Lattice Geometries As Measured By Laser Doppler Velocimetry, Yi Qiao

Doctoral Dissertations

"The relation between flow stream turbulence and heat transfer has been known for a long time, that the heat transfer rate is increased if the turbulence or fluctuation level of the flow increases. Open cell foams and compact heat exchangers are two of the most common models applied for heat transfer augmentation. However, the small ligaments of open cell foams limit the heat conducted and smooth passages in compact heat exchangers cannot cause flow unsteadiness. Accordingly, new geometric models are needed to improve the heat transfer enhancement. Three-dimensional (3D) lattice geometries with a range of features and sizes can be …

Enhancing Traffic Safety In Unpredicted Environments With Integration Of Adas Features With Sensor Fusion In Intelligent Electric Vehicle Platform With Implementation Of Environmental Mapping Technology, David S. Obando Ortegon

College of Graduate Studies: Theses & Dissertations

A major objective on society is to reduce the number of accidents and fatalities on the road for drivers, and pedestrians. Therefore, the automotive engineering field is working on this problem through the development and integration of safety technologies such as advanced driving assistance systems. For this reason, this work was intended to develop and evaluate the performance of different ADAS features and IV technologies under unexpected scenarios. This by the development of safety algorithms applied to the intelligent electric vehicle designed and built in this work, through the use of ADAS sensors based on sensor fusion. Evaluation of AEB, …

An Experimental Study On The Mechanical Properties And Chemical Composition Of Lcd 3d Printed Specimens, Sebastian Gomez

College of Graduate Studies: Theses & Dissertations

Additive manufacturing technologies have been enhanced throughout the years yet have surprised the manufacturing industry due to their high-end surface finish and dimensional accuracy. Different experiments have been done to identify a specific phenomenon known in the vat-polymerization field. Distortion and dimensional inaccuracy tend to affect the overall properties of the process, either physical or chemical. This approach allows the understanding of how the physical properties have been affected and how to study the chemical properties to avoid this type of phenomenon. The chemical reaction between polymer and UV light has been studied and experimented with to the point that …

Synthesis And Processing Of Pcl And Irdye Nanoparticles For Application In Drug Release Mechanism, Michael Adeniyi

College of Graduate Studies: Theses & Dissertations

The objective of this study is to produce core-shell nanoparticles utilizing PCL and IRDye and investigate the nanoparticle release mechanism. Biodegradable polymer, Polycaprolactone (PCL), was electrosprayed separately with two types of IRDye, NHS and Dextran Texas red. The solution of PCL was formed by mixing PCL in a solution of 9.47ml Acetic Acid, 9.47ml Formic Acid, and 1.05ml Trifluoroethanol, following a ratio of 9:9:1. The two solutions of IRDye were prepared by mixing 2mg of the IRdye with 20ml of DMF at a rate of 0.1mg/ml.

The NHS IRDye was electrosprayed coaxially with PCL and the Dextran Texas red dye …

Harnessing The Potential Of Fibrous Polyester Composites Meant For Bioactive Medical Devices, Graciela Morales, Heriberto Rodríguez-Tobías, Victoria Padilla-Gainza, Karen Lozano, Daniel Grande

Mechanical Engineering Faculty Publications

Fibrous-based composite polyester mats have gained importance in the biomedical area due to their morphological characteristics and mechanical performance. These materials can be modified by incorporating different inorganic micro- or nano-particles, thus leading to promising potential applications as medical devices with antimicrobial and/or bioactive properties. In this regard, this chapter reports a compilation of different studies related to the development of sub-micron fibers based on two important polyesters for biomedical use, namely poly(3-hydroxybutyrate) and poly(lactic acid). Studies focus on fibers developed through hydrodynamic techniques, namely electrospinning, electrospraying, and centrifugal spinning. The incorporation of zinc oxide or hydroxyapatite on the polyester-based …

Low-Fidelity Design Optimization And Parameter Sensitivity Analysis Of Tilt-Rotor Evtol Electric Propulsion Systems, Tyler Critchfield, Andrew Ning

Faculty Publications

Urban air mobility requires a multidisciplinary approach to tackle the important chal- lenges facing the design of these aircraft. This work uses low-to-mid fidelity tools to model rotor aerodynamics, blade structures, vehicle aerodynamics, and electric propulsion for a tilt-rotor electric vertical takeoff and landing (eVTOL) aircraft. We use gradient-based design optimization and extensive parameter sensitivity analysis to explore the design space and complex tradeoffs of tilt-rotor distributed electric propulsion systems.

A Coupled Source Panel, Actuator Line, And Viscous Vortex Particle Method In An O(N) Scheme, Ryan Anderson, Andrew Ning

Faculty Publications

Wake interactions play a significant role in aerodynamics. However, common modeling approaches are either expensive or lack fidelity, making them unreliable or difficult to use in the design process. The vortex particle method can capture the relevant physics effectively, but imposing boundary conditions with solid surfaces in a computationally efficient way is challenging. We explore two possible methods of imposing solid surface boundary conditions of vortex particle simulations. The first, a novel variation on a pure particle approach, is easy to implement but is moderately expensive, and suffers from some numerical instability. The second, source panels accelerated with a fast …

Sparsity For Gradient-Based Optimization Of Wind Farm Layouts, Benjamin T. Varela, Andrew Ning

Faculty Publications

Optimizing wind farm layouts is an important step in designing an efficient wind farm. Optimizing wind farm layouts is also a difficult task due to computation times increasing with the number of turbines present in the farm. The most computationally expensive part of gradient- based optimization is calculating the gradient. In order to reduce the expense of gradient calculation, we performed a study on the use of sparsity in wind farm layout optimization. This paper presents the findings of the sparsity study and provides a method to use sparsity in wind farm layout optimization. We tested this sparsity method by …

Triangular Fin Array Passively Actuated By Bimetallic Coils For Cubesat Thermal Control, Josh Cannon, Rydge B. Mulford, Brian D. Iverson

Faculty Publications

CubeSat thermal control can be especially demanding due to volume and size constraints, high power dissipation per unit surface area, and highly variable internal and external heat loads. As such, CubeSat developers must rely on thermal control systems that meet the specific requirements of their mission and environmental conditions. Deployable radiators enable satellites to increase their radiative surface area and to reveal highly emissive surfaces during times when increased heat rejection is desired. In colder conditions, when decreased heat loss is preferable, the radiators can be stowed. Passive thermal control systems are unpowered and can increase system reliability by not …

Advances In Precision Microfabrication Through Digital Light Processing: System Development, Material And Applications, Xinhui Wang, Jinghang Liu, Yang Zhang, Per Magnus Kristiansen, Aminul Islam, Michael Gilchrist, Nan Zhang

Articles

Digital Light Processing (DLP) is an advanced additive manufacturing technology which has garnered substantial recognition and has been extensively applications in various fields. This review focuses on the precision microfabrication process of DLP, providing an overview of the DLP 3D printing system, including the digital light engine, project lenses, motorised stage and resin vat for micro-structure fabrication. Additionally, this review paper comprehensively analyses commercially available DLP printers, covering resolution, cost and a detailed discussion on the importance of photopolymer resins, emphasising the monomer, photo-initiator, photoabsorber, etc. Based on the photopolymerisation theory, the DLP high-precision printing process is analysed, which is …

Lead Acid Battery Recycling In The Current Tanzania Industrialization Drive: Challenges And Opportunities, Divina D. Kaombe

Tanzania Journal of Engineering and Technology (TJET)

ABSTRACT Advancements in automotive technologies, Information and Communications Technology and renewable energy technologies have increased the use of lead acid batteries as a source of portable and rechargeable energy. This has considerably increased the number of spent batteries with adverse effects on the environment and human health; which calls for recycling of spent batteries. This work was conducted to investigate challenges facing the formal business of recycling spent batteries and potential manufacturers of new lead-acid batteries in Tanzania. The work involved collection of information from key stakeholders such as collectors, dealers, Tanzania Revenue Authority and recyclers. It was found out …

Interrogating The State Of Application Of Technology Within The Malawi Maritime Force As Maritime Expression : A Task-Technology Fit Approach, Gift William Kamwendo

World Maritime University Dissertations

No abstract provided.

Properties Of (Cd, Zn)S Films Deposited By Dc Co-Sputtering, Lwitiko P. Mwakyusa

Tanzania Journal of Engineering and Technology (TJET)

CdS thin film is commonly used as a buffer layer in most thin film solar cells. However, the buffer layer with less absorption in the visible region of the solar spectrum as well as that which provides perfect lattice matching with the absorbers is required. The incorporation of Zn in the CdS films can affect the structural and optical properties of the buffer layer. In this work, films of CdS and (Cd,Zn)S films were deposited by DC sputtering utilizing CdS and Zn targets. The concentration of Zn in the CdS was varied by changing the sputtering power of the Zn …

Review Of The Imaging Performance And The Current Status Of The Cascade Gamma-Rays Coincidence Imagers, Leonid L. Nkuba Dr.

Tanzania Journal of Engineering and Technology (TJET)

Various studies that have investigated the detection of gamma coincidence events have revealed that design factors and image reconstruction approaches dictate the spatial resolution, coincidence efficiency, and levels of statistical noise of the detection system. In the case of imaging, cascade gamma-ray coincidence (CGC) imagers coupled with collimated detectors offer promising values for both spatial resolution and coincidence efficiency. However, to date, no CGC imager with single or multiple collimated detectors has reported a performance level beyond 6.7 mm spatial resolution (FWHM) and 6.0 × 10-6 coincidence efficiency. Given the recent developments and the current interests in high resolution and …

Analysis Of Ore Hand-Crushed Size Distribution For Grinding Process In The Artisanal And Small-Scale Gold Mines Production: A Case Study Of Nholi Mine, Bahi District, Malugu Tembo

Tanzania Journal of Engineering and Technology (TJET)

(ASGM) employed numbers of people compared to large-scale mines. The ASGM has been played a crucial role in poverty alleviation and rural development, particularly in developing countries. The mined ore is crushed and ground for beneficiation of gold. The grinding process involved the size reduction of blasted materials to acquire minerals of interest. This paper presents the size distribution of hand-crushed for blasted materials using sieve analysis and digital image processing. The sieve test results for hand-crushed blasted material of three muck-piles were ranged between 17 mm and 36 mm that is equivalent to 20% and 80% passings respectively, with …

Synthesis, Characterisation And Catalytic Evaluation Of Castor Oil-Templated Mesoporous Sulfated Solid Acid Catalysts For Esterification Reaction, Steven Nyandoro Pr

Tanzania Journal of Engineering and Technology (TJET)

In bio-refinery and other catalytic reactions, heterogeneous catalysts confer advantage over homogenous catalysts due to minimized recovery and separation costs. However, templating surfactant and solid support for the synthesis of heterogeneous catalysts ought to consider their cheap sources and environmentally friendliness for their sustainable use. Thus, with the vision to make the process significantly benign, in the present work, solid acids were synthesised from renewable sources (castor oil as surfactant and rice husk as the source of silica). The synthesised castor oil-templated mesoporous sulfonic acid modified catalysts (SO3H-MTS and SO3H-MT-RHS) were characterised and evaluated for catalytic esterification of acetic acid …

Optimization Of Pulsed Laser Deposition Parameters For Single Crystalline (011) Oriented Tetragonal Pzt Thin Films, Mahamudu H. Mtebwa

Tanzania Journal of Engineering and Technology (TJET)

Recent advances in nanotechnology applications require the processing of high-quality thin films. A systematic study of the optimization of Pulsed deposition parameters for (110) oriented tetragonal PZT thin films is reported in this work. Prior to film deposition, a highly tetragonal Pb(Zr0.5, Ti0.95) or PZT 05/95 was selected to be deposited on (110) oriented Strontium titanate, SrTiO3 substrate, STO(110) to insure small compressive misfit strain. Unlike SRO, the LSOM bottom electrode was then successfully grown at 620 °C, 1.0 J/cm2 and a target-substrate distance of 3.9 cm. Finally, deposition parameters of PZT were progressively optimized through monitoring film morphological changes. …

Energy Assessment Of E-Motorcycles As A Clean Transport Mode For Passenger Mobility: A Case Of Ilala District, Dar Es Salaam, John Shirima

Tanzania Journal of Engineering and Technology (TJET)

Electric motorcycles or e-motorcycles is a clean mode of road transport that present a prominent solution toward decarbonizing cities. Despite of e-motorcycles being cleaner than gasoline ones, at the moment, there is missing information whether it is feasible to replace gasoline motorcycles with e-motorcycles used for business transport purposes. This paper, therefore, presents the results comparing energy usage when using e-motorcycles and when using the gasoline motorcycles. The energy demand for driving passengers using an e-motorcycle in the precarious routes originated from Gongo la Mboto bus stop to Segerea bus stop, Buguruni Malapa, Gerezani bus stop, Kivukoni bus stop, and …

Coconut Shell Waste Treatment Technology For A Sustainable Waste Utilization: A Case Study Of The Smes In Bohol Village, Indonesia, Wahyu Anggo Rizal, Ria Suryani, Roni Maryana, Dwi Joko Prasetyo, Diah Pratiwi, Yuli Ary Ratnawati, Dini Ariani, Andri Suwanto

ASEAN Journal of Community Engagement

This project focused on the introduction of liquid smoke and bio briquette manufacturing technology to small and medium enterprises (SMEs) located in Bohol Village, Gunungkidul, Indonesia through technology transfer, training, and mentoring. These SMEs are engaged in the food business with the main product jenang ketan, a traditional food from Gunungkidul, especially in Rongkop District, and very popular among communities around and outside Gunungkidul. The traditional preparation of jenang ketan produces several by-products in the form of waste, which is dominated by coconut shell biomass. The project’s technology transfer was carried out through the procurement of a series of pyrolysis …

Urban Farming: Empowerment To Increase Economic, Education, And Nutritional Benefit For The Sub-Urban Community, Nasruddin Nasruddin, Yusuf Donner Dwiyantama, Banu Muhammad, Anom Bowalaksono, Dian Ayubi, Sarah Islamiati Pertiwi

ASEAN Journal of Community Engagement

This article discusses the urban farming program at Sekolah Master in Beji, Depok, Indonesia, which aims to provide the community with broader benefits, such as economy, education, and increased nutritional value. The project involves planting method that was introduced to this school community. The program itself consists of several stages, starting from the preparation—dissemination of the program and designing a plan for the greenhouse, the implementation—constructing the greenhouse and installing the automatic water system, planting the vegetation, and monitoring and evaluation of the program. Eventually, an evaluation of the successful program is required to determine whether the program can be …

Nozzle Reactive Hydroturbine With Guide Device, O O. Bozarov, Kh S. Usarov, R Aliyev, S F. Ergashev

Technical science and innovation

The article presents the principle of operation of a jet turbine with a nozzle based on the "Segner" wheel and studies its shortcomings. In order to eliminate the identified shortcomings, a guide device was developed, which is installed inside the hydraulic turbine impeller. Using the Bernoulli equations and the Zhukovsky theory, the energy parameters of a microhydroelectric power station with a developed divertor device and the water flow rate in a hydroturbine are determined. The energy parameters calculated on the basis of theoretical results are analyzed, and it is found that the efficiency of a hydroturbine increases by 10-20% depending …

Damage Stability Study Of A 500 Dw Ro-Ro Ferry Vessel, Zulfaidah Ariany, Budhi Santoso, Sarwoko Sarwoko, Nauval Abdurrahman Prasetyo

Makara Journal of Technology

The development of the crossing transportation industry is currently increasing in the island areas. The use of Ro-Ro type ferry boats is extremely efficient in moving people, goods, and vehicles. The current research focuses on the damage stability of the 500 DWT Ro-Ro ferry, which aims to meet the needs of the Ro-Ro ferry in the archipelago area. The previously existing initial design of a barge hull with a main size Lpp = 40.15 m, B = 12 m, H = 3.2 m, and T = 2.15 m was used to analyze the damage stability condition further. First, the drawings …

Comparative Analysis Of Injection Of Pyrolysis Oil From Plastics And Gasoline Into The Engine Cylinder And Atomization By A Direct High-Pressure Injector, Magdalena Szwaja, Jeffrey Naber, David Shonnard, Daniel G. Kulas, Ali Zolghadr, Stanislaw Szwaja

Michigan Tech Publications, Part 1

The article discusses the results of experimental studies on the course of pyrolysis oil injection through the high-pressure injector of a direct-injection engine. The pyrolysis oil used for the tests was derived from waste plastics (mainly high-density polyethylene—HDPE). This oil was then distilled. The article also describes the production technology of this pyrolysis oil on a laboratory scale. It presents the results of the chemical composition of the raw pyrolysis oil and the oil after the distillation process using GC-MS analysis. Fuel injection tests were carried out for the distilled pyrolysis oil and a 91 RON gasoline in order to …

Bio-Inspired Micromachined Volumetric Flow Sensor With A Big Dynamic Range For Intravenous Systems, Lansheng Zhang, Yingchen Yang, Georgios A. Bertos, Chang Liu, Huan Hu

Mechanical Engineering Faculty Publications

Real-time monitoring of drug delivery in an intravenous infusion system can prevent injury caused by improper drug doses. As the medicine must be administered into the vein at different rates and doses in different people, an ideal intravenous infusion system requires both a low flow rate and large dynamic range monitoring. In this study, a bio-inspired and micromachined volumetric flow sensor is presented for the biomedical application of an intravenous system. This was realized by integrating two sensing units with different sensitivities on one silicon die to achieve a large dynamic range of the volumetric flow rate. The sensor was …