Engineering Commons^™

A Study Of The Effect Of Vibration On Railroad Bearing Temperature, Bertha Alicia Gonzalez

Theses and Dissertations - UTB/UTPA

An on-track collaborative field test and laboratory experiments were conducted in order to determine the relationship between abrupt rises in surface temperature of a railroad bearing and vibration signatures captured during the experiments. The collaborative field test was conducted in order to investigate the root cause for this abrupt temperature change known as bearing temperature trending. The research presented in this thesis will show that temperature trending is correlated to an increase in the magnitude of vibration within the bearing and the fundamental frequencies that are generated by the internal components of a rotating bearing assembly. Distinct vibration mechanisms are …

The Effectiveness Of Damage Arrestment Devices In Delaying Fastener-Hole Interaction Failures In Carbon Fiber Polyurethane Foam Composite Sandwich Panels Subjected To Static And Dynamic Loading Under Increased Temperatures, Dominic E. Surano

Master's Theses

A study was conducted to investigate simple, cost-effective manufacturing techniques to delay skin-core delamination, micro-buckling and bearing stress failures resulting from fastener-hole interactions. Composite sandwich panels, with and without damage arrestment devices (DADs), were subjected to monotonic compression at a rate of 5mm per second, and compression-compression fatigue at 50% yield at an amplitude of 65%, under temperatures of 75, 100, 125, 150, 175, and 200 °F.

The sandwiches tested were composed of two-layer cross-weave carbon fiber facesheets, a polyurethane foam core, and an epoxy film adhesive to join the two materials. The most successful method to delay the aforementioned …

Irrigation Leak Detection: Using Flow Rate Sensors To Detect Breaks In An Irrigation System, Adam Openshaw, Kalvin Vu

Computer Engineering

This report details the exploration and invention of a mechanism that can detect breaks in an irrigation system. With the ultimate goal of conserving water, we have designed an inexpensive, self sustaining flow rate monitor that can be used to identify anomalies in an irrigation system and wirelessly communicate the status of the system to a base station. Our implementation can also determine the direction of the anomaly based on the nature of the anomaly itself. This means that multiple monitors can be used to pinpoint the location of a break within the system in addition to merely detecting its …

Mathematical Modeling Of Light Utilization And The Effects Of Temperature Cycles On Productivity In A Steady-State Algal Photobioreactor, Peter Edwin Zemke

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The work presented here investigated two methods of improving productivity in microalgal photobioreactors: applying temperature cycles intended to maximize photosynthesis and minimize respiration, and development of a mathematical model that predicts improvements in photon utilization using temporal light dilution (flashing).

The experiments conducted on diurnal temperature cycles with Dunaliella tertiolecta in 30-L outdoor photobioreactors showed that a properly chosen temperature cycle can improve mass and energy productivity by 18% over an identical photobioreactor with a constant temperature. However, excessively large temperature cycle amplitudes reduced productivity. A 4-7% increase in energy content was observed in microalgae exposed to temperature cycles. The …

Effects Of Temperature And Humidity On Glass-Reinforced Nylon Rotating Bands, Marc D. Raby

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Certain 30mm munitions used in various military applications are configured with a glass-reinforced nylon band that acts as a firing ring or rotating band. The purpose of this research is to investigate whether storage environments compromise the strength and integrity of the glass-reinforced nylon rotating bands by researching the environmental factors that will degrade nylon and by performing tests to investigate if these factors will embrittle nylon composites. Moisture and temperature are found to be the environmental factors that will have an effect on the rotating bands in their respective storage environments. Absorbed moisture is found to increase the impact …

Simultaneous Measurement Of Deformation And Temperature Of High-Strength Concrete At Very Early Age To Determine The Initial And The Finial Setting Time, Shu-Ken Lin, Chung-Ho Huang, Chao-Shun Chang, Tsong Yen, Chung-Hao Wu, Yiching Lin

Journal of Marine Science and Technology

The interior shrinkage deformation and temperature change of high-strength concrete (HSC) at very early age, i.e., the first 24 h from casting, and up to an age of 72 h was investigated experimentally using optic fibre sensors (SOFO) and thermally sensitive resistors. The initial and the final setting times of HSC were also investigated. Results show that two turning points (I and II) on the development curve of deformation, both represent the onsets of the variation of rigidity in fresh HSC, can be recognized as the initial and the final setting times, which are evaluated around 4.5 h to 5.7 …

Effect Of Temperature On Tribological Properties Of Palm Biodiesel

A.S. Md Abdul Haseeb

Biodiesel, as an alternative fuel is steadily gaining attention to replace petroleum diesel partially or completely. The tribological performance of biodiesel is crucial for its application in automobiles. In the present study, effect of temperature on the tribological performance of palm biodiesel was investigated by using four ball wear machine. Tests were conducted at temperatures 30, 45, 60 and 75 °C, under a normal load of 40 kg for 1 h at speed 1200 rpm. For each temperature, the tribological properties of petroleum diesel (B0) and three biodiesel blends like B10, B20, B50 were investigated and compared. During the wear …

Measurement And Analysis Of Temperature And Pressure In High Altitude Air Shipments, Sher Paul Singh, Jay Singh, J. Stallings, Gary J. Burgess, K. Saha

Industrial Technology and Packaging

This study was performed (at the request of the FAA) to measure temperature and pressure conditions observed by standard packages in the FedEx Next Day Air network and the environmental conditions of passenger aircrafts. To measure the single parcel environment, two destinations known to be served by non-pressurized feeder and pressurized aircrafts in the USA, San Luis Obispo, California, and Twin Falls, Idaho, were used to represent higher altitude paths. Test packages (0.30 × 0.30 × 0.30 m) containing one MadgeTech PRTemp110 recorder were shipped Priority Overnight by FedEx from East Lansing, Michigan. For 6 weeks, two test packages were …

Thermal Analysis Of Natural Convectiona And Radiation In Porous Fins, Mehulkumar G. Maheria

ETD Archive

No abstract provided.

Temperature Effect On Microstructure And Electromagnetic Performance Of Polycarbosilane And Sugar-Doped Mgb2 Wires, Andrey V. Shcherbakov, Josip Horvat, Olga V. Shcherbakova, Nikolina Novosel, Emil Babic, S. X. Dou

Faculty of Engineering - Papers (Archive)

The effect of processing temperature on structural and superconducting properties of 10 wt.% sugar- and 10 wt.% PCS-doped MgB₂ wires is systematically investigated. It is demonstrated that these dopants significantly enhance the electromagnetic performance of Fe-clad MgB₂ superconductor and increase its potential for practical application. The enhancement of in-field critical current density (J_c(B_a)) and upper critical field (B_c2) is due to formation of a large amount of lattice defects caused by impurities and C substitution into the MgB₂ crystal lattice. High temperature sintering of sugar-doped sample results …

Effect Of Bulk Temperature On The Tribological Performance Of Aqueous Symmetric Tri-Block Copolymers (Ppo-Peo-Ppo And Peo-Ppo-Peo) Based Lubricant, Oyong Novareza, P B. Kosasih, A K. Tieu, Hongtao Zhu

Faculty of Engineering - Papers (Archive)

This work investigates the effect of bulk temperature and the tribological performance of a number of symmetric triblock copolymers on MSI020 commonly in metal forming. It is to determine the best bulk temperature for the lubricants in order to apply in metal fOlming application. The triblock polymers are temperature dependant'. The polymers can be compeletly dissolved in solution since of hydrogen bonding in certain temperature. As temperature increases, the bond is weakend and the polymer break from the water and form dispersion in the water

A Hybrid Highly Birefringent Fiber Optic Sensing System For Simultaneous Strain And Temperature Measurement, Piotr Lesiak, Ginu Rajan, Yuliya Semenova, Gerald Farrell, Anna Boczkowska, Andrzej Domanski, Tomasz Wolinski

Faculty of Engineering and Information Sciences - Papers: Part A

A novel hybrid fiber optic sensor based on integration of polarimetric fiber sensors for simultaneous strain and temperature measurement is presented in this paper. Two types of polarimetric fibers are used: a side-hole fiber and a polarization maintaining photonic crystal fiber. The disadvantage of each sensor type can be overcome by using the sensors in a complementary manner to measure temperature independently from average strain. © 2010 Photonics Society of Poland.

Evaluation Of High Temperature Fatigue Behaviour Of P22 By Miniature Specimen Testing, M D. Callaghan, S. R Humphries, M Law, H Li, W.Y Yeung

Faculty of Engineering - Papers (Archive)

Miniature specimen testing to evaluate mechanical properties, presents a novel opportunity to undertake structural integrity assessments of in-service power generation components, by removing only a very small volume of material. In this study, high temperature fatigue testing of P22 steel was undertaken and a number of fatigue properties determined using a miniature specimen testing methodology. Good comparisons were observed between fatigue properties determined by miniature specimens and the more established standard-sized specimen testing reported in literature.

A Study Of The Continous Cooling Behaviour And Effect Of Preheat And Interpass Temperature On The Haz Of High Strength Quenched And Tempered Steel, Lenka Kuzmikova, Mark Callaghan, Nathan Larkin, Robert Scott, Robert De Jong, Huijun Li, John Norrish

Faculty of Engineering - Papers (Archive)

In this study, the continuous cooling phase transformation behaviour of a quenched and tempered armour steel was investigated. A continuous cooling transformation diagram was constructed providing valuable information for predicting microstructural evolution and mechanical properties at different cooling rates during actual welding fabrication. Welding trials were carried out utilising flux-cored arc welding technique in combination with an austenitic stainless steel consumable. The effect of various preheat and interpass temperatures on cooling rate and consequently on the heat affected zone microstructure and mechanical properties of multipass welds were investigated.

Vertical Absorption Edge And Temperature Dependent Resistivity In Semihydrogenated Graphene, Lei Chen, Zhongshui Ma, Chao Zhang

Faculty of Engineering - Papers (Archive)

We show that for graphene with any finite asymmetry in the on-site energy between the two sublattices (Δ), the optical absorption edge is determined by the Δ. The universal conductance will be broken and the conductance near the band edge varies with frequency as 1/ω². The onset conductance is σ_c = 2σ₀ = πe²/2h, independent of the size of the band gap. The total integrated optical response is nearly conserved despite of the opening of the band gap. Moreover, near the band edge, there is a change over of …

Magnetotransport Of La0.70ca0.3-Xsrxmno3(Ag): A Potential Room Temperature Bolometer And Magnetic Sensor, V P. Awana, Rahul Tripathi, Neeraj Kumar, H Kishan, G V. Bhalla, Rong Zeng, L.S Sharth Chandra, V Ganesan, H U. Habermeier

Australian Institute for Innovative Materials - Papers

Here we report the optimized magnetotransport properties of polycrystalline La_0.70Ca_0.3−xSr_xMnO₃ and their composites with Ag. The optimization was carried out by varying the Sr and Ag contents simultaneously to achieve large temperature coefficient of resistance (TCR) as well as low field magnetoresistance (MR) at room temperature. Sharpest paramagnetic (PM)-ferromagnetic (FM) and insulator-metal (IM) transition is observed in the vicinity of the room temperature (T_C≈300 K ≈T_IM) for the composition La_0.70Ca_0.20Sr_0.10MnO₃:Ag_0.20. Partial substitution of larger Sr²⁺ ions at the …

The Development Of Scalable Pump Techniques For Gg Iag Fiber Lasers And Passive Athermalization Techniques For Solid State Laser, William Hageman

Electronic Theses and Dissertations

This dissertation consists of two parts: research pertaining to the development of scalable pump techniques for gain guided index-antiguided fiber lasers and research relating to the development of passive athermalization schemes for solid state lasers. The first section primarily details the development of a side pump scheme that allows for power scaling of gain-guided index anti-guided fibers. While these fibers have been demonstrated in past research, none have used a pump technology capable of pumping with the efficiencies, uniformity, and necessary length to allow for scaling of the fiber lasers to high output powers. The side pumped scheme developed in …

Ab-10-017: Combined Effects Of Noise And Temperature On Human Comfort And Performance (1128-Rp), Dale Tiller, Lily M. Wang, Amy Musser, Matthew Radik

Durham School of Architectural Engineering and Construction: Faculty Publications

This paper summarizes results from an experiment designed to investigate the combined effects of noise and temperature on human thermal comfort and task performance. Thirty subjects (16 females, 14 males) were exposed to all combinations of five thermal conditions (PMV +1 [79.6°F:26.4°C], PMV +0.5 [75.8°F:24.3°C], PMV 0 [72.1°F:22.3°C], PMV -0.5 [68.3°F:20.2°C], and PMV -1 [64.6°F:18.1°C]), three RC noise levels (RC-30, RC-40, and RC-50), and two sound qualities (neutral and rumbly): all sounds mimicked noise from building ventilation systems. After a one-hour adaptation period at each condition, subjects rated their thermal comfort using the ASHRAE Thermal Comfort Scale and the Tenant …