Architectural Engineering Seminar Series
Fall 2009
DATE |
EVENT |
Sept. 11, 2009 |
Guest Speaker: Dr. James D. Freihaut 12:00 - 1:00 p.m. Title: "Indoor Air Quality and the Resuspension of Contaminant Containing Indoor Particles" Abstract: Epidemiologic studies continue to expand the associations of negative health effects with exposure to specific, indoor dust, particle-associated contaminants. Both viable and non-viable indoor contaminants are vectored to building occupants on micron and submicron sized particles. But, apart from flu virus concerns, it is the non-viable natural and synthetic chemicals found in indoor environments that are generating most epidemiologic concerns. Non-viable, molecular contaminants - pesticides, insecticides, fire retardant chemicals, protein allergens, mycotoxins, endotoxins, phthalate plasticizers, polycyclic aromatics, and lead - are embedded within or adsorbed on surfaces of micron and sub-micron sized dust particles. It is these specific, particle-associated, chemical contaminants, that are being linked to specific illnesses - leukemia, prenatal birth defects, infant development disorders, allergic response syndromes and asthma - via respiratory and transdermal transmission processes. Since most populations in developed societies spend 85% or more of their time indoors, these populations are subject to long term, continual exposures to these ubiquitous contaminants. The aerobiological pathways of occupant exposures to the various types and size ranges of indoor particle carried contaminants is not well understood, making risk estimates and mitigation strategies difficult to delineate The presentation reviews what is known about the epidemiology of indoor particle associated health effects and dust reservoir – to – occupant inhalation or transdermal exposure pathways. Results of particle resuspension measurements made in a controlled resuspension chamber are summarized. The experimental resuspension measurements made for a wide range of particle types are able to reconcile apparently, widely disparate, indoor particle resuspension and inhalation exposure rates found in the published literature. The results point to indoor environment measurement technologies and particle control and air treatment technologies that need to be developed to reduce occupant risks to particle carried contaminants.
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Oct. 2, 2009 |
Guest Speaker: Dr. Ghassem Heidarinejad Title: Low-Energy Hybrid Cooling Systems Abstract: Is it possible to construct a building operates on the zero energy basis in cooling? Excluding passive cooling, the answer is no. What are the systems approaching to above-mentioned limit? In this presentation, few among many of suggested hybrid cooling systems are presented and discussed in more details. Preliminary results are promising but cannot compete at the present level of energy prices especially crude oil!
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Oct. 16, 2009 |
Guest Speaker:Thomas C. Kuczynski Title: The Experimental Investigation of the Multi-Hazard Resistant Panelized Brick Veneer on Steel Stud Wall System for Out-of-Plane Failure Loading Abstract: This project investigates the out of plane strength of an existing wall system design that has been enhanced for blast resistance. The study involved the design and construction of a uniform load testing facility capable of testing 8 foot x 8 foot wall specimens to failure. Full-scale experimental and finite element modeling results compare the effects of the wall system enhancements by comparing/contrasting the load-deflection curves for the various specimens.
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Nov. 13, 2009 |
Guest Speaker:Gaby Issa El-Khoury Title: Bending and shear strength of horizontally curved plate girders with longitudinally stiffened webs Abstract: Horizontally curved plate girders have become more and more popular for bridge engineering applications. Plate girders are usually deep beams with relatively thin webs and, subsequently, web buckling becomes an important factor during design. When the limit state of web buckling occurs first, transverse and longitudinal stiffeners may be used to increase section strength. Straight girders have been extensively studied with respect to stiffener placement, resulting in well defined recommendations for the most effective location of both transverse and horizontal stiffeners. Horizontally curved girders have not been as extensively studied and their behavior is more complex. The study investigates simple span, horizontally curved, plate girders with yield stresses of 50 ksi to investigate optimal horizontal stiffener location. Parametric studies are conducted for a range of girder radii, section slenderness and unbraced lengths using ABAQUS and sections are examined under bending, shear and combined bending and shear conditions. Results from the studies will be presented and will provide insight related to recommended longitudinal stiffener positions for a practical range of horizontally curved, plate girder sections.
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Nov. 20, 2009 |
Guest Speaker: Dr. Fredericka Brown Herron Title: Evaluation of Thermal Comfort and Energy Demands in University Classrooms Abstract: With the increase in mechanical ventilation as the main source for heating and cooling in buildings, the concept of thermal comfort is being widely investigated. Comfort level in an environment depends on several factors, some of which vary from person to person. The comfort level can affect an occupant’s attention, learning, hearing, performance, and concentration level. In a school or university environment, students are required to perform tasks that require a high level of concentration; hence it is important that students are thermally comfortable. Research conducted on effects of HVAC controlled environments on students’ performance shows that improving indoor environment significantly enhances performance of many tasks, mainly the time used to complete tasks and errors committed were decreased. The impetus of the study is to evaluate the current HVAC energy demands of a select classroom at The University of Texas at Tyler at present thermal set points and compare the current energy demands with energy demands based on operating the system at the preferred temperature of occupants. To determine the preferred temperature range of the students, a subjective assessment is performed by questionnaire survey in an auditorium style classroom along with objective measurements of thermal comfort parameters (air velocity, operative temperature and relative humidity). The questionnaire survey includes questions about thermal sensation, perception, acceptability, and relevant demographic and clothing data. Fanger’s thermal comfort model is used to calculate the Predicted Mean Vote (PMV) and Percentage People Dissatisfied (PPD). Regression analysis on survey data provides the range of neutral, preferred and acceptable temperatures in the classroom.
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Dec. 4, 2009 |
Guest Speaker: Dr. Stanley A. Mumma Title: DOAS and Building Pressurization Abstract: Predicting building leakage rates during the design phase is fraught with many uncertainties. None the less, buildings are intentionally pressurized in an effort to limit infiltration and its associated impact on occupant well being, terminal equipment performance, and energy consumption, The presentation addresses DOAS issues under occupied and unoccupied pressurization conditions. Those issues include: equipment components and configurations, climate related performance, reserve capacity, first cost, and energy operating cost. In conclusion, a new DOAS configuration is recommended. |