76 research outputs found

    A Catholic and Marianist Engineering Education

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    The School of Engineering at the University of Dayton (UD), a Catholic and Marianist University, boasts large enrollments of 1,300 undergraduate and 350 graduate students out of a total of 7,000 undergraduates and 3,000 graduate students. It also boasts a faculty very active in research, which, under the umbrella of the University of Dayton Research Institute, is funded at a level of $100 million per year. In the past decade, the University of Dayton has sought to better articulate the impact of its Catholic and Marianist traditions, and faculty have been challenged to embody these traditions. University mission statements and unit strategic plans have also evolved to make better connections. In this context, our paper explores the historical and present connections to these traditions, and then more importantly presents a vision for better integration of them into the education of our students. The visioning really represents an early foray into thinking about greater embodiment of mission into the engineering education at Catholic universities. Finally, we envision what a specific application of the principles to a course in thermodynamics would look like and consider extension to all engineering courses

    Effects of thermocapillarity on an evaporating extended meniscus in microgravity

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    An analytical investigation of the effects of thermocapillarity on the flow field within and heat transfer from the extended meniscus region of a heated meniscus which is re-supplied by capillarity is presented. Microgravity conditions are considered. The analysis shows that even for extremely small temperature differences between the wall and the vapor (less than 1 mK) thermocapillary stresses at the liquid-vapor interface due to a non-uniform interfacial temperature drastically alters the flow field. At the same time, these stresses were shown to have only a slight effect on the heat transfer from the extended meniscus but increasing with an increasing temperature difference. Additionally, thermocapillary effects were shown to be sensitive to pore size. A criterion was established from a scaling analysis identifying the conditions necessary for thermocapillarity to affect the operation of capillary-pumped heat transport devices in microgravity. A critical Marangoni number and corresponding critical temperature difference between wall and vapor were identified

    Carbon Nanoadditives to Enhance Latent Energy Storage of Phase Change Materials

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    Latent energy storage capacity was analyzed for a system consisting of carbon nanoparticlesdopedphase changematerials (PCMs). Three types of samples were prepared by doping shell wax with single wall carbon nanotubes(SWCNTs), multiwall CNTs, and carbon nanofibers. Differential scanning calorimetry was used to measure the latent heat of fusion. The measured values of latent heat for all the samples showed a good enhancement over the latent heat of pure wax. A maximum enhancement of approximately 13% was observed for the wax/SWCNT composite corresponding to 1% loading of SWCNT. The change in latent heat was modeled by using an approximation for the intermolecular attraction based on the Lennard-Jones potential. A theoretical model was formulated to estimate the overall latent energy of the samples with the variation in volume fraction of the nanoparticles. The predicted values of latent energy from the model showed good agreement with the experimental results. It was concluded that the higher molecular density of the SWCNT and its large surface area were the reasons behind the greater intermolecular attraction in the wax/SWCNT composite, which resulted in its enhanced latent energy. The novel approach used to predict the latent heat of fusion of the wax/nanoparticle composites has a particular significance for investigating the latent heat of PCM with different types of nanoparticle additives

    Capillary Pumped Heat Transfer (CHT) Experiment

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    The operation of Capillary Pumped Loops (CPL's) in low gravity has generally been unable to match ground-based performance. The reason for this poorer performance has been elusive. In order to investigate the behavior of a CPL in low-gravity, an idealized, glass CPL experiment was constructed. This experiment, known as the Capillary-driven Heat Transfer (CHT) experiment, was flown on board the Space Shuttle Columbia in July 1997 during the Microgravity Science Laboratory mission. During the conduct of the CHT experiment an unexpected failure mode was observed. This failure mode was a result of liquid collecting and then eventually bridging the vapor return line. With the vapor return line blocked, the condensate was unable to return to the evaporator and dry-out subsequently followed. The mechanism for this collection and bridging has been associated with long wavelength instabilities of the liquid film forming in the vapor return line. Analysis has shown that vapor line blockage in present generation CPL devices is inevitable. Additionally, previous low-gravity CPL tests have reported the presence of relatively low frequency pressure oscillations during erratic system performance. Analysis reveals that these pressure oscillations are in part a result of long wavelength instabilities present in the evaporator pores, which likewise lead to liquid bridging and vapor entrapment in the porous media. Subsequent evaporation to the trapped vapor increases the vapor pressure. Eventually the vapor pressure causes ejection of the bridged liquid. Recoil stresses depress the meniscus, the vapor pressure rapidly increases, and the heated surface cools. The process then repeats with regularity

    Clean Energy Infrastructure Educational Initiative

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    The Clean Energy Infrastructure Educational Initiative represents a collaborative effort by the University of Dayton, Wright State University and Sinclair Community College. This effort above all aimed to establish energy related programs at each of the universities while also providing outreach to the local, state-wide, and national communities. At the University of Dayton, the grant has aimed at: solidfying a newly created Master\u27s program in Renewable and Clean Energy; helping to establish and staff a regional sustainability organization for SW Ohio. As well, as the prime grantee, the University of Dayton was responsible for ensuring curricular sharing between WSU and the University of Dayton. Finally, the grant, through its support of graduate students, and through cooperation with the largest utilities in SW Ohio enabled a region-wide evaluation of over 10,000 commercial building buildings in order to identify the priority buildings in the region for energy reduction. In each, the grant has achieved success. The main focus of Wright State was to continue the development of graduate education in renewable and clean energy. Wright State has done this in a number of ways. First and foremost this was done by continuing the development of the new Renewable and Clean Energy Master\u27s Degree program at Wright State . Development tasks included: continuing development of courses for the Renewable and Clean Energy Master\u27s Degree, increasing the student enrollment, and increasing renewable and clean energy research work. The grant has enabled development and/or improvement of 7 courses. Collectively, the University of Dayton and WSU offer perhaps the most comprehensive list of courses in the renewable and clean energy area in the country. Because of this development, enrollment at WSU has increased from 4 students to 23. Secondly, the grant has helped to support student research aimed in the renewable and clean energy program. The grant helped to solidify new research in the renewable and clean energy area. The educational outreach provided as a result of the grant included activities to introduce renewable and clean energy design projects into the Mechanical and Materials Engineering senior design class, the development of a geothermal energy demonstration unit, and the development of renewable energy learning modules for high school students. Finally, this grant supported curriculum development by Sinclair Community College for seven new courses and acquisition of necessary related instrumentation and laboratory equipment. These new courses, EGV 1201 Weatherization Training, EGV 1251 Introduction to Energy Management Principles, EGV 2301 Commercial and Industrial Assessment, EGV 2351 LEED Green Associate Exam Preparation, EGV 2251 Energy Control Strategies, EGV Solar Photovoltaic Design and Installation, and EGV Solar Thermal Systems, enable Sinclair to offer complete Energy Technology Certificate and an Energy Management Degree programs. To date, 151 students have completed or are currently registered in one of the seven courses developed through this grant. With the increasing interest in the Energy Management Degree program, Sinclair has begun the procedure to have the program approved by the Ohio Board of Regents

    A Study of the Fundamental Operations of a Capillary Driven Heat Transfer Device in Both Normal and Low Gravity Part 1-Liquid Slug Formation in Low Gravity

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    Research has been conducted to observe the operation of a capillary pumped loop (CPL) in both normal and low gravity environments in order to ascertain the causes of device failure. The failures of capillary pumped heat transport devices in low gravity; specifically; evaporator dryout, are not understood and the available data for analyzing the failures is incomplete. To observe failure in these devices an idealized experimental CPL was configured for testing in both a normal-gravity and a low-gravity environment. The experimental test loop was constructed completely of Pyrex tubing to allow for visualization of system operations. Heat was added to the liquid on the evaporator side of the loop using resistance heaters and removed on the condenser side via forced convection of ambient air. A video camera was used to record the behavior of both the condenser and the evaporator menisci simultaneously. Low-gravity experiments were performed during the Microgravity Science Laboratory (MSL-1) mission performed onboard the Space Shuttle Columbia in July of 1997. During the MSL-1 mission, a failure mechanism, heretofore unreported, was observed. In every experiment performed a slug of liquid would form at the transition from a bend to a straight run in the vapor line. Ultimately, this liquid slug prevents the flow of vapor to the condenser causing the condenser to eventually dryout. After condenser dryout, liquid is no longer fed into the evaporator and it, too, will dry out resulting in device failure. An analysis is presented to illustrate the inevitable formation of such liquid slugs in CPL devices in low gravity

    Electro-hydrodynamic Pumped Hydraulic Actuation with Application to Active Vibration Control

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    A new type of actuation device has been conceptualized that meets the needs of both large displacement, force and bandwidth within a package more compact than currently available magnetostrictive and stack-type piezoelectric actuators of similar rating. This concept relies on micro-scale electrohydrodynamic (EHD) pumping of a dielectric liquid within small channels. Configured as an actuator, the EHD pump(s) would be used to move fluid between two reservoirs—each having a compliant membrane that interfaces to the world to provide the means to achieve vibration cancellation or micro actuation. Ordinarily limited to generating flow in macroscale applications, the EHD pump, when operating in a thermal induction mode, is shown to exhibit an exciting scaling law as its size is reduced. As the pump volume to surface area decreases, the energy going toward increasing pressure in the pump has an increasingly larger effect. Since the volume/surface area is proportional to 1/a, where a is the characteristic width or diameter of the channels comprising the pump, the pressure head generated scales similarly. Analytical and numerical studies have shown the EHD-pumped actuator to be capable of delivering equal force and bandwidth to magnetostrictive and stack-type piezo actuators, but with considerably greater displacement and roughly 1/10th of the size. Further, this type of actuator offers the possibility for deployment in active vibration control or micro actuation applications at significantly greater temperatures than for piezoelectric and magnetostrictive devices

    A Clean Energy Utility for Multifamily Housing in a Deregulated Energy Market

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    Energy efficiency and renewable energy (EERE) investment in multifamily residences in the United States has not kept pace with investment in resident-owned facilities. Split incentives, where owners cannot benefit economically from energy cost savings for residences and resident investment in EERE is not feasible, have posed a significant barrier. A clean energy utility is posited to circumvent this barrier. This utility would be responsible for power purchase from the grid, ideally as a real-time purchase agent from the grid manager; investment in energy efficiency and renewable energy; and demand management through control of water heating, as well as supply-side management through deployment of stored solar at near-peak grid power purchase cost. A clean energy fee is posed for recovery of costs, in contrast to typical consumption strategies (per kW h). A case study approach is employed to evaluate the feasibility of this type of utility of reducing carbon production in this building sector. Considered in the analysis is a 2008 multifamily facility located in the Midwest of the U.S., with apartment level interval meters for both power and water. Historical data from these meters were used to assess the savings and demand-side management potential from investments in improved efficiency lighting, refrigeration, heat pumps, and water heaters, as well as investments in solar PV and storage for supply-side management. The results show that the packaged retrofit EERE investment could yield costs for residents and profits for energy manager comparable to those in the current residential pricing scheme, while reducing grid-sourced energy by 42%. When solar PV and battery storage are added to the solution, it is shown that a clean energy fee structure can cost-effectively drive savings to over 54%. For new construction, even deeper cost effective savings are realizable. This research demonstrates the potential to drive deep energy savings in the multifamily building sector that can lower costs to residents through the establishment of clean energy utilities which recover investments in energy efficiency, demand management, and solar PV/battery systems through resident clean energy fees rather than consumption fees

    Nanocharacterization of Bio-Silica Using Atomic Force and Ultrasonic Force Microscopy

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    Nanotechnology has become central to our research efforts to fabricate relatively smaller size devices, which are more versatile than their older and larger predecessors. Silica is a very important material in this regard. Recently, a new biomimetically inspired path to silica production has been demonstrated. This processing technique was inspired from biological organisms, such as marine diatoms, which produce silica at ambient conditions and almost neutral ph with beautiful control over location and structure. Recently, several researchers have demonstrated that positional control of silica formed could be achieved by application of an electric field to locate charged enzymes responsible for the bio catalytic condensation of silica from solution. Secondly, chemical and physical controls of silica structural morphology were achievable. Atomic Force Microscopy (AFM) and Ultrasonic Force Microscopy (UFM) techniques are employed for the first time to provide both substantially improved resolution of the morphology and relative measurement of the modulus of elasticity of the structures. In particular, these measurements reveal the positive impact of a shear flow field present during the silica formation on both the ordering of the structure and the mechanical properties

    Analysis of Solar Photovoltaic and Wind Power Potential in Afghanistan

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    Afghanistan has a need for increased access to energy to enable development. In this paper we analyze the potential for large-scale grid-connected solar photovoltaic (PV) and wind power plants in two of Afghanistan\u27s most populous provinces (Balkh and Herat) to meet a large fraction of growing electricity demand. The results presented here represent the first quantitative analysis of potential capacity factors and energy yields of power plants in the country using measured wind speed and typical solar radiation data. Variability of resources is also investigated by comparing temporal profiles with those of electricity demand, using residual load duration curves to determine penetration and curtailment levels for various demand scenarios. We show that solar PV and wind power plants in two provinces could achieve penetration levels of 65%–70% without significant curtailment, which in turn would mean less reliance on unpredictable and unstable power purchase agreements with neighboring countries, longer life of limited domestic fossil fuel resources, and lower imports of diesel fuel, thus avoiding rising costs and detrimental environmental impacts. Our results point to an alternative development pathway from that of previous recommendations for conventional thermal power plants, controversial hydroelectric projects, and a significant dependence on imported power
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