Mechanical Engineering Commons^™

Investigation Of Cell Behavior In 3d Printed Lumen Structures For Capillary Regeneration, Victoria Jade Perez

Theses and Dissertations

This thesis work successfully generated a coaxial printing setup and process to generate 3D printed tubules. A dual syringe pump mechanism was developed to print tubular structures to investigate cell behavior with a goal to generate future capillary beds. The mechanism involves the use of collagen–alginate tubules and the use of EDTA to increase the porosity of the tubule structures to study their interaction with media and incubation techniques as well as behavior and morphology. Tubules of 1.7% sodium alginate and 0.4% collagen I reacting with 3.2% CaCl2 solution proved to be more stable in both the printing process and …

Production And Characterization Of Polyurethane Fibers By Forcespinning Method And Incorporation Of Luminiscense Nanoparticles, Sunanda Kumar Saha

Theses and Dissertations

In this work, Polyurethane (PU) fine fiber nonwoven mats are generated using the Forcespinning® method. A detailed study focusing on the effect of PU concentration within solutions of N, N Dimethylformamide and the effect of relative humidity (RH) on fiber average diameter and fiber yield is presented. Solutions were prepared with 4 different concentrations, 14, 15, 16 and 17 wt% of PU. It was observed that as concentration of PU increases, average diameter shows a tendency to increase. Production of fibers with RH varying from X to X was analyzed. It was shown that higher RH is convenient for PU …

Effect Of Obesity On Knee Joint During Walking And Squatting, Simon Vasquez Iii

Theses and Dissertations

This paper analyzes the effect of obesity on the knee joints during squats. This was performed on 2 different subjects by having each squat 30 times at their decided comfortable depth to display some fatigue and effects on the knee joints. Using the VICON NEXUS and AMTI force plates equipment at The University of Texas at Rio Grande Valley Biomechanics Lab, the center of pressure, knee flexion angles, velocity, and ground reaction forces were calculated. The subjects performed the exercises with and without additional weight using a body vest and kettlebell. The ground reaction forces showed a significant increase in …

Effect Of Deposition Conditions On Properties Of Molybdenum Back Electrode For Cu(In,Ga)Se2 Solar Cell And Cu(In,Ga)Se2 Performance Analysis Through Numerical Simulation, Meah Imtiaz Zulkarnain

Theses and Dissertations

In the first part of this research, the effect of the deposition conditions on properties of molybdenum thin-film were investigated to achieve desired characteristics for its application as the back electrode of Cu(In,Ga)Se2 solar cell. DC and RF magnetron sputtering modes were employed and two sputtering parameters namely, working pressure and sputtering power, were varied to determine the sputtering mode and the sputtering conditions best suited for Mo thin-films having required properties. Sputtered Mo samples were characterized to determine their structural and mechanical properties such as preferred growth orientation, crystallinity, grain size, dislocation density, adhesion, and micro strain, and electrical …

Using Single-Molecule Dna Flow-Stretching Experiments To See The Effects Of Temperature And Viscosity, Fatema Tuz Zohra

Theses and Dissertations

Deoxyribonucleic acid (DNA) is a highly charged long and semi-flexible polymer of which length is much longer than cell dimensions at least by 1,000-folds. A long linear DNA turns into a crumpled structure to fit into a tiny cell volume by the process known as DNA compaction. In nature, DNA fits into the volume of the cell using DNA compaction by packaging genome material. Various types of protein are involved in DNA compaction. To experiment with various proteins as DNA compaction agents, DNA needs to be stretched out. In our thesis, the effect of temperature and buffer viscosity on DNA …

A Manufacturing-To-Response Pathway For Formed Carbon Fiber Reinforced Polymer Composite Structures, Madhura Limaye

All Theses

Over the past decade, there has been an increased adoption of thermoplastic and thermoset based continuous carbon fiber reinforced polymer (CFRP) composites for structural applications in several industries. Among the different manufacturing methods, thermoforming process for thermoplastic based continuous CFRP’s offer a major advantage in reducing cycle times for large scale productions. Similarly, out-of-autoclave curing process for thermoset based continuous CFRP’s using heated tooling enables production of large composite structures. However, these manufacturing processes can have a significant impact on the structural performance of parts by inducing undesirable effects. These effects include inhomogeneous fiber orientations, thickness variations, and residual stresses …

Microstructure, Mechanical Performance, And Corrosion Behavior Of Additively Manufactured Aluminum Alloy 5083 With 0.7 And 1.0 Wt% Zr Addition, Le Zhou, Holden Hyer, Jinfa Chang, Abhishek Mehta, Thinh Huynh, Yang Yang, Yongho Sohn

Mechanical Engineering Faculty Research and Publications

Effect of 0.7 wt% and 1.0 wt% of Zr alloying on the laser powder bed fused (LPBF) printability/buildability of AA5083 alloys was investigated by examination of the microstructure and mechanical property. General corrosion behavior of these Zr-modified AA5083 alloys produced by LPBF in 3.5 wt% NaCl solution was also examined and compared to the LPBF AlSi10Mg alloy and AA5083-H131 alloy. Unmodified AA5083 alloy produced by LPBF exhibited extensive solidification cracks, but alloying it with Zr mitigated the cracking due to the grain refinement from the formation of the primary L1₂-Al₃Zr. Moreover, 1.0 wt% of Zr alloying …

Effect Of Obesity On Walking To Running And Running To Walking Transitions, Salvador Baruch Alcorta Bautista

Theses and Dissertations

This work investigates human Walking to Running transition (WRT) and Running to Walking transition (RWT). The focus is to be able to identify the correct WRT and RWT phase jumps. This investigation uses experimental data from the VICON Motion Analysis System (MAS) and of the treadmill WRT and RWT trials. The musculoskeletal model consists of pelvis, femur, tibia, and foot. This investigation uses as reference the work reported in the literature by Diedricj and Warren.. For the calculations in this investigation Excel and Matlab are used to filter the data and calculate the relative phase jumps. This work reports the …

Machinability Of Carbon Fiber Reinforced Polymer (Cfrp) Composites: Modeling And Optimization Using Taguchi Analysis And Multi-Objective Genetic Algorithm, S M Abdur Rob

Theses and Dissertations

Carbon Fiber Reinforced Polymer (CFRP) composites have been widely used in aerospace, automotive, nuclear, and biomedical industries due to their high strength to weight ratio, corrosion resistant durability and excellent thermo-mechanical properties in non-oxidative atmospheres. Machining of CFRP composites has always been a challenge for the manufacturers. In this study, turning operation has been performed on CFRP composites to investigate the effects of cutting parameters namely cutting speed, feed rate and depth of cut on the output characteristics including cutting force, surface roughness and tool wear using Taguchi Analysis. Regression Analysis has been used to develop mathematical model for cutting …

Two-Dimensional Modeling Of Nonlinear Dynamics Of Forcespinning Jet Formation, Dumitru I. Caruntu, Simon Padron, Karen Lozano

Mechanical Engineering Faculty Publications

Forcespinning is a novel method that makes use of centrifugal forces to produce nanofibers rapidly and at high yields. To improve and enhance the forcespinning production method, a 2D computational forcespinning inviscid fluid dynamics model is developed. Two models, namely, time-independent and time-dependent, are obtained in order to investigate the effects of various parameters on fiber forcespinning formation (trajectory, jet diameter, tangential velocity). The fluid dynamics equations are solved using the method of multiple scales along with the finite difference method and including slender-jet theory assumptions. It is important to produce jets with small diameters in the micro- and nanorange. …

Effect Of Additional Weight On Stability Of Human Squat Exercise, Jose De Jesus Galarza Lozano

Theses and Dissertations

The main focus of the study is to analyze the stability of the squat exercise. The squat is a common exercise that persons do for exercise. The study analyze the time series of the normal component of the ground reaction forces and each coordinate of the center of pressure. Theses time series are used to estimate the Lyapunov Exponents using Rosenstein method. MATLAB from Mathworks is used to calculate the graphs and program the methods. We compare this result with the literature and previous experiments. This work gives more information relating the safety of the squat exercise when …

Toward An Understanding Of Fundamental Mechanisms In Transitional And Turbulence Flow Control, Ethan A. Davis

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Turbulence is an emergent phenomenon found throughout nature and engineering, alike. It plays a vital role in the aquatic locomotion of organisms, scalar mixing, fluid transport, shipping and transportation, and even the flow of biological fluids in the human body. Therefore, it is of utmost importance in both a practical and engineering sense to better understand turbulence with the goal of better controlling it. This dissertation focuses broadly on better understanding the underlying mechanisms behind wall-bounded turbulent flows, with an emphasis on exploiting those mechanisms for turbulence flow control.

We developed a numerical simulation to study the effect of slip …

Thermomechanical Modeling In Laser Powder Bed Fusion Additive Manufacturing Using Graph Theory: Application To Prediction Of Recoater Crash, Md Humaun Kobir

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

This work pertains to the laser powder bed fusion (LPBF) additive manufacturing process. The objective of this thesis is to predict a frequently occurring type of thermal-induced process failure in LPBF called recoater crash. To ascertain the likelihood of a recoater crash before the part is printed, we develop and apply a computationally efficient thermomechanical modeling approach based on graph theory.

Despite its demonstrated ability to overcome the design and processing constraints of conventional subtractive and formative manufacturing, the production-level scaleup of LPBF is hindered by frequent build failures. For example, the part often deforms as it is being printed …

Development Of A Mash Tl-3 Compliant Parapet Mounted Fence, Luis Rodriguez Alvizo

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

When roadways pass over railway tracks, there is a risk that debris from the roadway or pedestrians may fall onto the tracks and interfere with railway operations. Because of this, state Departments of Transportation (DOTs) commonly install debris fences in conjunction with bridge rails over railway tracks. However, the safety performance of debris fence systems when impacted by an errant vehicle has not been demonstrated through full-scale crash testing. Thus, the objective of this research was to develop a new, parapet-mounted debris fence for the Iowa DOT according to safety performance guidelines included in the American Association of State Highway …

The Coalescence Of Incipient Soot Clusters, Akaash Sharma, Khaled Mosharraf Mosharraf Mukut, Somesh Roy, Eirini Goudeli

Mechanical Engineering Faculty Research and Publications

Reactive molecular dynamics (MD) simulations are employed to investigate the coalescence of incipient soot clusters. Initially, one thousand acetylene molecules collide and react with each other, allowing bond breakage and new bond formation upon collision, leading to various species (e.g., linear hydrocarbons, branched polyaromatic hydrocarbons) up to the formation of nascent soot clusters with diameter of up to 3.5 nm. The structure and composition of the formed soot clusters are quantified by the packing density and carbon-to-hydrogen (C/H) ratio, respectively, during nucleation and up to the formation of large nascent soot nanoparticles. Then, the nucleated incipient soot clusters are isolated …

Development Of A Low-Cost, Photovoltaic-Powered, Automated Water Recovery System, David E. Daley

Master's Theses

An existing water filtration system at the Channel Islands Marine & Wildlife Institute (CIMWI) wastes approximately 25 gallons of water per day rinsing out solid waste under light load. To reduce CIMWI’s water and energy consumption, an automated system was designed and built to recover the rinse water and return it to the existing filtration loop. Models for fluid system requirements, basic energy needs, and photo- voltaic energy generation were created to aid in component selection. Basic sensors and electronics were programmed in Python for use with a Raspberry Pi single board computer to collect and process water recovery data …

Musculoskeletal Adaptation Of Young And Older Adults In Response To Environmental, Physical, And Cognitive Conditions, Amy E. Holcomb

Boise State University Theses and Dissertations

Accidental falls present a large functional and financial burden among people aged 65 years and older. Falls, injuries associated with falls, and the fear of falling decrease quality of life, physical function, and independence for older adults. To prevent falls, improve stability, and protect joints from damage or injury, the typical response to "challenging" conditions include cautious gait, increase muscle co-contraction, and decreased range of motion. These compensatory strategies are more pronounced in the older adult population with apprehensive "cautious" gait at slower speeds, decreased knee flexion, and increased muscle activation around the knee and ankle. The underlying mechanisms and …

Phase Change Temperature Sensor For High Radiation Environment: Material, Additive Technology And Structure Development, Al Amin Ahmed Simon

Boise State University Theses and Dissertations

Performance of any sensor in a nuclear reactor involves reliable operation under a harsh environment (i.e., high temperature, neutron irradiation, and a high dose of ionizing radiation). In this environment, accurate and continuous monitoring of temperature is critical for the reactor's stability and proper functionality. Furthermore, during the development and testing stages of new materials and structural components for these systems, it is imperative to collect in-situ measurement data about the exact test conditions for real-time analysis of their performance. To meet the compelling need of such sensing devices, we propose radiation-hard temperature sensors based on the phase change phenomenon …

Performance Of Calcium Chloride- Ammonia Adsorption Refrigeration System, Michael John

Tanzania Journal of Engineering and Technology (TJET)

An experimental study on the performance of calcium chloride-ammonia adsorption system is described. A single bed water cooled condenser adsorption refrigerator prototype, which utilises calcium chloride-ammonia pair has been developed and tested in the laboratory. Experiments have been conducted for desorption temperatures of 100 °C with desorption time varying from 1 to 4 hours. An electric tape heater and a timer were used to perform the experiments. The adsorption temperature profile, adsorption rate and prototype performance have been analysed and discussed. The tested heating and desorption temperature of 100 °C and heating and desorption time of 1 to 4 hours …

Assessment Of The Impacts Of Climate Variability On Hydropower Generation: A Case Study Of The New Pangani Falls, Tanzania, Dativa Byarufu

Tanzania Journal of Engineering and Technology (TJET)

Climate change poses potential impacts on hydropower generation either positively by increasing or negatively by decreasing river flow. This study assessed the impacts of climate variability on hydropower with a focus on the New Pangani Falls in Tanzania. Rainfall and temperature time series data from 1980-2014 were analyzed in relation to river discharge and associated impacts to hydropower generation. The Man-Kendall test was used to detect trend in both annual and seasonal time series. The results showed a negative trend in annual rainfall with Z= -2.41 at α = 0.05 and the slope Q = -0.964. Seasonal trend analysis showed …

Socio-Technical Perspective For Electronic Tax Information System In Tanzania, Lucas Ngowi, Ellen Kalinga

Tanzania Journal of Engineering and Technology (TJET)

Socio-technical systems theory has rarely been used by system architects in setting up computing systems. However, the role of socio-technical concepts in computing, which is becoming social in nature, has made the concepts more relevant and commercial. Tax information systems are examples of such systems because they are influenced by external variables such as the political environment, technological trends, and social environment, introducing complexity in their deployment and determining the type of e-services and their delivery to a diverse group of people. It was observed that in Tanzania there is resistance, reluctance and minimal use of electronic tax system because …

Electrochemical Corrosion Properties Of Ternary Al And Quaternary Zr Added Bell Metal In 0.1m Nacl Solution, Sakib Al Razi Khan, Mohammad Ashfaq Hossain, Maglub Al Nur, Mohammad Salim Kaiser

Journal of Mechanical Engineering Science and Technology (JMEST)

The electrochemical corrosion property of ternary Al and quaternary Zr added Bell metal in 0.1M Sodium Chloride solution has been experimentally conducted at room temperature. Electrochemical impedance spectroscopy (EIS) method and Potentiodynamic polarization technique are used to carry out the electrochemical investigation. Microhardness test is also conducted for all three alloys and it reveals that Al addition increases the hardness of bell metal due to the formation of different intermetallic precipitates of Cu and Al. Optical Micrograph as well as Scanning Electron Micrograph have also been studied to characterize their surface condition. It is found that Zr addition refines the …

Evaluating Storage And Effective Moduli Of In Situ Polymerised And Melt Extruded Pa6 Graphite (G) Composites, Muneer Umar, Michael Ikpi Ofem, Auwal Sani Anwar, Muhammad Murtala Usman

Journal of Mechanical Engineering Science and Technology (JMEST)

Four PA6/graphite (G) composites systems were made. Two using in situ polymerisation equivalent in mixing strain and two systems melt extrusion of equivalent processing strain. The effective modulus of the carbons, room temperature storage modulus and storage modulus at 80 ⁰C were evaluated. The composite/unfilled PA6 ratios at E25 and that at E80 for the in situ polymerised system IG 40/10 are 1.37 and 1.63, respectively. For the in situ polymerised system IG 20/20, the same were 1.96 and 2.28, respectively. For the melt-extruded systems, G 100/6 had the best E25 ratio of 1.67 and E80 of 2.03, whereas the …

The Effect Of Thickness And Type Of Material On The Sheared Edge Characteristics Of Keychain Cranioplasty Plate Blanking Product Using Eccentric Press Machine, Didin Zakariya Lubis, Lea Rachmat Indrasepta, Redyarsa Dharma Bintara, Rizky Ramadhan, Agung Budi Darmawan

Journal of Mechanical Engineering Science and Technology (JMEST)

Keychain cranioplasty plate product has the potential to be produced using the blanking process because it is faster, low-cost, and requires low-energy consumption compared to other mechanical operations. This research aimed to find the effect of material thickness and type on the sheared edge characteristics of keychain cranioplasty plate using the blanking process to meet the international health standard. Experimental research conducted using an eccentric press machine with 40 tons capacity. This research’s test material parameters of titanium (Ti-6AL-4V) and stainless steel (SS-316L) were the 0.5 mm, 0.6 mm, and 0.8 mm thickness with a maximum blanking velocity of 3000 …

Effect Of Dcrp And Dcsp Polarity On The Depth Of Penetration Of Smaw On Low Carbon Steel Astm A36 Using E7018 Electrode, Ma'mun Hidayat, Helleni Febnesia, Sulaeman Deni Ramdani

Journal of Mechanical Engineering Science and Technology (JMEST)

The study aims to determine the level of penetration depth using SMAW (Shielded Metal Arc Welding) Process based on the polarity type of DCRP (Direct Current Reverse Polarity) and DCSP (Direct Current Straight Polarity). This research used ASTM A36 low carbon steel plate with thickness of 6 mm and length of 200 mm, Electrode E7018 LB-52-18 ∅ 3.2 mm, and with current parameters of 90 A, 100 A, 110 A, 120 A and 130 A and 70 ° welding arc angle. The method used the experimental research. Data collection techniques applied direct observation techniques and descriptive statistical data analysis techniques. …

Camshaft Failure Simulation With Static Structural Approach, Riduwan Prasetya, Andoko Andoko, Suprayitno Suprayitno

Journal of Mechanical Engineering Science and Technology (JMEST)

A failure happens within the camshaft of the minibus when the vehicle is in utilize. The camshaft was a fracture within the bearing between the primary cylinder exhaust valve and the second cylinder suction. This simulation aims to find the causes of camshaft failure utilizing the finite element method with a static structural approach, including simulations of deformation, strain, stress, fatigue life (stress-life and strainlife), and cracks. The method used in this paper is the finite element method with a static structural approach by ANSYS software. The camshaft material is a gray cast iron designed using Solidworks. Pre-processing includes meshing …

The Effect Of Multi-Extrusion Process Of Polylactic Acid On Tensile Strength And Fracture Morphology Of Filament Product, Muhamad Syaifuddin, Heru Suryanto, Suprayitno Suprayitno

Journal of Mechanical Engineering Science and Technology (JMEST)

Polylactic acid (PLA) is one of the most used materials in FDM 3D Printing. Large-scale consumption of PLA on an industrial scale could cause environmental and efficiency problems. Thus, PLA waste and industry waste need to be recycled to limit excessive waste. This study aimed to investigate the change in mechanical property, morphology, and structure of mechanically recycled PLA. Recycling was performed 12 times using the extrusion process with an extrusion temperature nozzle of 170°C. The SEM, structural analysis, and amorphous-crystalline analysis used XRD. The results showed a gradual decrease of tensile strength from each recycle with a total of …

Fully Coupled Internal Radiative Heat Transfer For The 3d Material Response Of Heat Shield, Raghava S. C. Davuluri, Rui Fu, Kaveh A. Tagavi, Alexandre Martin

Mechanical Engineering Faculty Publications

The radiative transfer equation (RTE) is strongly coupled to the material response code KATS. A P-1 approximation model of RTE is used to account for radiation heat transfer within the material. First, the verification of the RTE model is performed by comparing the numerical and analytical solutions. Next, the coupling scheme is validated by comparing the temperature profiles of pure conduction and conduction coupled with radiative emission. The validation study is conducted on Marschall et al. cases (radiant heating, arc-jet heating, and space shuttle entry), 3D Block, 2D IsoQ sample, and Stardust Return Capsule. The validation results agree well for …

Interaction Of A Shock Wave With A Particle Curtain, Daniel M. Freelong

Mechanical Engineering ETDs

This thesis presents an experimental study of the interaction of a normal shock wave with a sparse curtain of particles. Soda lime particles with a nominal diameter of 40 micrometers are used to form the curtain. A high speed camera captured several segments of the particle curtain flow from the front view, including the early formation stages. The frames from the video segments were then extracted into individual sequential images. Properties were found using the images such as the velocity fields, time evolution of multiphase Atwood number, and perturbation growth. Volume fractions were derived from mass discharge measurements and particle …

Main Factors That Influence The Thermal Stress State Of Piston Engine Parts, J F. Ismatov, A I. Yangibayev, N V. Vadulina, A A. Jalilov

Technical science and innovation

The development of a holistic, effective, and scalable structure of economic management, as well as the introduction of a program to improve the technical level and efficiency of machinery, are two of the most important concepts for the deep reconstruction of the Republic of Uzbekistan's economic process. Vehicles with diesel engines are gradually being introduced to our country's car fleet. Modern diesel engines are being developed by boosting them: increasing the average effective pressure and speed. Therefore, high reliability and service life, fuel efficiency and environmental performance are the main criteria for their quality. Forcing diesels leads to an increase …