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Harmonic Forcing of Damped Non-homogeneous Euler-Bernoulli Beams
No full textThis work is an extension of previous studies on vibrations of non-homogeneous structures. It also explores the use of logistic functions. In the studies, frequency response functions (FRFs) were determined for segmented structures, using analytic and numerical approaches. The structures are composed of stacked cells, which are made of different materials and may have different geometric properties. Here the steady state response, due to harmonic forcing, of a segmented damped Euler-Bernoulli beam is investigated. FRFs for the system are sought via two methods. The first uses the displacement differential equations for each segment. Boundary and interface continuity conditions are used to determine the constants involved in the solutions. Then the response, as a function of forcing frequency, can be obtained. This procedure is unwieldy. In addition, determining particular integrals can become cumbersome for arbitrary spatial variations. The second approach uses logistic functions to model the segment discontinuities. The result is a single partial differential equation with variable coefficients. Approaches for numerical solutions are then developed with the aid of MAPLE® software. For free-fixed boundary conditions, spatially constant force and viscous damping, excellent agreement is found between the methods. The numerical approach is then used to obtain the FRF for the case of a spatially varying force
Hydrodynamic cavitation based advanced oxidation processes: Studies on specific effects of inorganic acids on the degradation effectiveness of organic pollutants
No full textThe use of cavitation in advanced oxidation processes (AOPs) to treat acidic effluents and process water has become a promising trend in the area of environmental protection. The pH value of effluents – often acidified using an inorganic acid, is one of the key parameters of optimization process. However, in the majority of cases the effect of kind of inorganic acid on the effectiveness of degradation is not studied. The present study describes the results of investigations on the use of hydrodynamic cavitation (HC) for the treatment of a model effluent containing 20 organic compounds, representing various groups of industrial pollutants. The effluent was acidified using three different mineral acids. It was demonstrated that the kind of acid used strongly affects the effectiveness of radical processes of oxidation of organic contaminants as well as formation of harmful secondary pollutants. One of important examples is a risk of formation of p-nitrotolune. Sulfuric acid was the only chemical used for acidification which caused effective treatment with lack of formation of monitored type of secondary pollutants. The best treatment effectiveness – during a 6-hour cavitation process - in most cases much above 80% along with 90% TOC removal was obtained in the case of sulfuric acid. Nitric acid provided lower effectiveness (above 60% for most of the compounds). The worst performance are reported for hydrochloric acid – below 50% of degradation for most of the compounds
Virtual Impedance-based Grid Synchronization for Converters Connected Through Long Cables
No full textThis paper proposes a synchronization scheme for grid-connected Voltage Source Inverters (VSI) without physical interface inductors, voltage sensing or conventional PLL algorithms. Especially, issues with converters connected trough long cables are addressed. These cables present non-negligible LC characteristics that can lead to resonance peaks degrading current or voltage waveforms. A virtual impedance is used as grid coupling element, providing a virtualized synchronization point within software using only already available current-sensor information. Also, virtual resistance is used to actively dampen resonance peaks caused by cable characteristics. Theoretical analysis and simulation results are presented to verify the proposed strategy
Experimental Study of Synergism in N2 and SF6 Gas Mixtures
No full textAlthough sulfur-hexafluoride (SF 6 ) has been used as an insulating medium in various power system applications it has been shown that its greenhouse effect is significant. Due to this effect throughout the world, many countries have already issued restrictions on the usage of SF 6 , which may adversely affect various apparatus and systems presently being used in power industry. In order to solve the problem without a delay studies have been undertaken to find a replacement gas for pure SF 6 so that the existing insulation of a power apparatus or a system can be modified. Among many alternatives, nitrogen and SF 6 (N 2 + SF 6 ) mixtures seem to be the simplest and the least expensive alternative due to N 2 being inert, abundant and renewable. Because SF 6 is an electronegative gas, the synergism may take place in mixtures of SF 6 with N 2 . The synergy in a gas mixture is considered when the value of the dielectric strength of the mixture is higher than the value determined by the linear combination of the dielectric strengths of each component gas in the mixture. Therefore, in this study the degree of synergism is assessed due to electronegativity of SF 6 and the non-linear behavior of this binary mixture in order to determine if there exists an optimum SF 6 concentration
Investigating the Experiences of Military Professionals who Return to Engineering Graduate School
Get PDFThose graduate students known as returners, who have a gap of at least five years between their undergraduate degree conferral and their return to school for a graduate degree, have a wide variety of different experiences. While many of them spend those gap years in employment at an industrial employer, some of them serve in the military in various capacities. As military experience is different from working at an industrial employer, one might expect that these returners will be different in their outlook, skills, or approach to learning. In this study, the differences between military returners and returners from industry are examined. Twenty-one returners were interviewed, of whom seven had either served in or worked directly for the military as a civilian. The interview protocol covered the participants’ decision-making process, challenges they experienced in the program, and whether and how their past experiences interacted with or had an influence on their education. The transcripts of these interviews are analyzed, and the two groups are compared, with key differences and similarities, such as their approach to leadership, noted. In addition, the findings from this analysis are compared to military personnel entering an undergraduate program, as reported in the literature
2/19/2020: Course Change Form ECE 100
No full textA new freshman course that introduces students to the principles of electrical and computer engineering. This course becomes one of the required foundational courses for the new BSE degree program
2/19/2020: Course Change Form MGT 102
No full textWhile still important, the program is moving away from a specific focus on systems thinking and instead of having independent courses in that discipline, the content is being included in other courses. This also opens up space for additional courses in the curriculum
2/19/2020: Course Change Form BUSN 206
No full textBalancing the course offerings due to other curriculum changes. This change will enable students to get an exposure of both principles of management and principles of marketing concepts during their freshman year. Under the proposed changes, Introduction to Marketing (old BUSN 206/new BUSN 103) will be offered as Freshman 1 Summer-Fall course. An understanding of basic management and marketing concepts will prepare students adequately for the Economic Principles ECON 201 which is a sophomore 1 summer-fall course
8/5/2020: Course Change Form - Remove Tech Track
No full textIn order to ensure a separate STEM classification, the Tech-MBA can’t be a specific track of the MBA program within the current CIP 52.0201. The Tech MBA has to be its own program with its unique CIP code (most likely CIP 15.1501) following the Department of Education’s NCES Classification of Instructional Programs (CIP) taxonomy. As a result of the creation of the separate Tech-MBA program, the Technical Track will be removed from the current MBA program and MBA program will only retain its Traditional MBA Track which reflect the following curriculum without any changes to the curriculum
No Date: COMM 201 - Rhetoric and Writing II
No full textThe revision of the current Liberal Studies General Education Program calls for the elimination of COMM 201 and the Writing Intensive (WI) requirement. All electives (except ECON) will require a minimum of writing. The elimination of COMM 201 will allow students to take four (rather than three) electives (one COMM, one HUMN, one SCCI, and one additional elective in COMM, HUMN, or SSCI)