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Title: Structural considerations in the design of modern abattoirs and cold storage warehouses
Creator: Edlund, Lawrence L
Date: 2009, 1920
Publisher: Armour Institute of Technology
Description: http://www.archive.org/details/structuralconsid00edlu
Thesis (B.S.)--Armour Institute of Technology

Title: Mycoflora of Indoor Dust and Alternaria Alternata Growth on Building Materials
Creator: Simpson, Stacy
Date: 2011-10-27, 2011-12
Description: Alternaria alternata, a clinically significant mold species is associated with allergic disease and asthma. An indoor growth of A. alternata...
Show moreAlternaria alternata, a clinically significant mold species is associated with allergic disease and asthma. An indoor growth of A. alternata may initiate atopic symptoms, accumulate in dusts, and discolor and deteriorate indoor building materials. Environmental control should be the initial approach to maintain a healthy indoor environment and manage allergic diseases. The current thesis investigated indoor dusts from various environments for mold spores and Alt a 1. Laboratory studies were carried out to determine if or which commercially available mold-resistant treatments and building materials could efficiently decrease A. alternata growth and Alt a 1. The mycoflora of indoor dusts was microscopically examined and the clinically significant allergen from A. alternata, Alt a 1 was measured in sampled dusts using a monoclonal anti-recombinant Alt a 1 (rAlt a 1) enzyme linked immuno-sorbent assay (ELISA). To investigate building material susceptibility untreated, mildew-resistant painted, and commercially available biocide treated building materials were inoculated with A. alternata spores, incubated in a humidity controlled chamber, and compared for mold growth and the presence of Alt a 1. A photo-monitoring technique was used to survey and determine mold growth surface area coverage. Alt a 1 immuno-reactivity of superficial mold growths was analyzed with the ELISA. The microscopic speciation of mold spores indicated that a diverse mycoflora can be found in indoor dusts. Although A. alternata was found in low concentrations in a few samples, Alt a 1was below the limit of detection. Nevertheless, mold spores can significantly contribute to the complexity of indoor dusts. A. alternata grew on all tested building materials but both painted and treated building materials inhibited mold growth in comparison to untreated samples. Not all material surfaces contained detectable levels of Alt a 1. Comparisons between untreated and painted building material groups indicated that a significant difference between the Alt a 1 accumulation content could not be established. To establish a standard sampling protocol and reliable prevention methods for mold contamination and exposure more knowledge about indoor molds must be gained.
M.S. in Environmental Engineering, December 2011
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Title: WEB-BASED CONTEMPORANEOUS DELAY ANALYSIS
Creator: Pektas, Murat
Date: 2011-11-22, 2011-12
Description: The construction industry is fragmented due to the many stakeholders and the diverse phases involved in a construction project. On time,...
Show moreThe construction industry is fragmented due to the many stakeholders and the diverse phases involved in a construction project. On time, within budget, with required quality are essentials of a successful project. However, most construction projects are faced with delays, which obstruct success. To recover the damage caused by delays, both the delays and the parties responsible for them should be identified accurately. Daily window delay analysis outperforms other delay analysis methods, but it requires intensive day-by-day information. The information flow among the project stakeholders must be smooth and speedy at all stages of the production process not only to achieve the basic project objectives but also to let project stakeholders recognize the delays and the parties responsible for them in order to recover time and cost. The Internet is attractive for transferring information promptly and economically with no regional or temporal borders. To merge the power of the Internet and to ease time consuming delay analysis, a web-based application is proposed to analyze delays effectively and contemporaneously, to reduce time and cost, and to provide historical data. The application considers the day-by-day variation in critical path(s) during the project life cycle. The application gives accurate and repeatable results for apportioning project delays, accelerations and decelerations among involved parties. The manual effort required by traditional systems is minimized with the application’s simple, easy to use, yet effective and highly automated features. Moreover, the database structure of the application is designed to store and manage more than one project at a time to let its users calculate the overall performance of the company including all projects, and to calculate average durations for activities that can come up in future projects.
M.S. in Civil Engineering, December 2011
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Title: A METHODOLOGY FOR MAJOR BUS ROUTE RESCHEDULING TO IMPROVE TRANSIT PERFORMANCE
Creator: Lu, Xi
Date: 2012-08-01, 2012-07
Description: In a period of growing transit operating deficits, increasing attention and concern is being directed at both the decreasing levels of...
Show moreIn a period of growing transit operating deficits, increasing attention and concern is being directed at both the decreasing levels of productivity of transit systems in general and the broad differences in measured service performance compiled for various transit systems. The purpose of this study is an assist public transit managers by providing them with a mathematical technique to analyze the efficiency with which serviced is produced and the effectiveness with which it is consumed. By providing the analysis model which not requires an extensive amount of data, the operator can have tool for decision-making of profit and market growth. Thus, transit managers will be able to access the performance of the agency and areas where improvements can be realistically achieved. Using the urban operation of the Chicago Transit Authority, a transit performance model is developed to analysis efficiency and effectiveness of the city's bus system. As the system exists, there are 144 bus routes start and end, frequency of dispatching buses and ridership changes from Weekdays and Weekend, peak hour and off-peak hour. In many of these routes, vehicles are used inefficiently and ineffectively, only a few passengers carried in some routes in off-peak hour, yet in other routes through the Central Business District (CBD) area, there are always not enough buses in peak hour. Also, some routes cannot provide enough on-time arrival service and some special group like elderly and handicapped cannot receive enough service in certain area. The goal of case research is to determine to understand the transit performance of Chicago Transit Authority and to select the optimal improvement projects to maximize the performance in term of economy and social equity.
M.S. in Civil Engineering, July 2012
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Title: DAMAGE DETECTION OF STRUCTURES USING INTERVAL FINITE ELEMENT METHOD
Creator: Venkitaraman, Shyamala
Date: 2012-04-16, 2012-05
Description: Health assessment and damage detection for existing structures is an essential procedure for their safe and reliable operation so that any...
Show moreHealth assessment and damage detection for existing structures is an essential procedure for their safe and reliable operation so that any catastrophic failure may be prevented in a timely manner. However, results obtained from a health assessment of a structure possess uncertainties in measurements, system properties and loads. Furthermore, the conventional deterministic structural analyses are incapable of considering these uncertainties, thereby resulting in error when estimating the state of health of a structure. Interval (unknown-but-bounded) representation is one method to quantify uncertainty in a physical system. Using an interval variable, the uncertain parameter is bounded between extreme values. In this work, a new method for damage assessment of structures is developed that utilizes the results from structural health assessment as uncertain input parameters in an interval finite element analysis scheme. This method, due to its capability of considering uncertainties, offers a more robust process for estimating the possible existence of damage and overall health of the structure. As an illustrative example, the method is applied for a failed sign support structure. First, the structure's response from previous health assessment procedure was used to construct uncertain interval responses. Then using these interval responses as input parameters, an interval finite element method was performed. The results of the analysis verify and correlate with the failure location of the actual structure. Moreover, the lifetime assessment of the structure obtained from this method is the lower bound of, and correlates with the actual failure time of the structure.
M.S. in Civil Engineering, May 2012
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Title: MONITORING, MODELING, AND TREATMENT OF ODORS/ODORANTS AT WATER RECLAMATION PLANTS
Creator: Zhang, Yanming
Date: 2012-04-23, 2012-05
Description: A thorough study including odor monitoring, modeling and treatment as three important aspects of odor control in WRPs has been performed in...
Show moreA thorough study including odor monitoring, modeling and treatment as three important aspects of odor control in WRPs has been performed in this research. Measurement of H2S emissions from odor sources was proven to be an essential step in odor monitoring program. The H2S emission rates were measured from various sources throughout a WRP for 9 sampling events during winter and summer. During summer, both the average and the maximum emission rates of H2S from liquid treatment processes increased significantly compared to those measured during winter. However, for solids-handling processes, the emission rates remained constant because sludge characteristics did not vary throughout the year. The total sulfide concentrations present in liquid treatment processes were higher than those in preliminary and primary treatment units but at much lower levels in secondary treatment. Rates of H2S emission from the headworks were correlated to daily average wastewater temperature, TKN concentration, and flow rate. AERMOD was used as the modeling tool to evaluate the odor impact of Egan WRP on the surrounding communities. The emission rates could significantly affect the modeling results. Long-term H2S monitoring increases the possibility of developing the proper emission rate for the worst-case scenario. Excluding the modeling during the night would avoid overestimation of odor impact and excessive odor control. In the laboratory-scale study of O3 oxidation of H2S, O3 oxidation was proven to be a fast and effective method to remove H2S from the odorous air emitted from wastewater treatment processes. The increased initial ratio of O3/H2S enhances the removal rate of H2S. The consumption ratio of O3/H2S is a function of input reactant ratios. A multiple linear regression model (R2=0.84) has been developed to predict the H2S residual for given initial H2S and O3 concentrations and reaction time. The increased moisture content of the odorous air enhanced the H2S removal while DMS and DMDS inhibit H2S removal by competing for the limited O3 supply.
Ph.D. in Environmental Engineering, May 2012
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Title: DETERMINATION OF REDUNDANCY IN STRUCTURES USING INTERVAL UNCERTAINTY ANALYSIS
Creator: Amirshaghaghi, Sayeh
Date: 2014, 2014-05
Description: Existence of redundancy in structures plays an important role in increasing their safety and reliability. However, using state-of-the-art...
Show moreExistence of redundancy in structures plays an important role in increasing their safety and reliability. However, using state-of-the-art deterministic and probabilistic approaches, all possibilities for estimation of redundancy (e.g. due to occurrence of different damage scenarios) have not been considered. One of the methods to quantify the presence of uncertainties in a system is to use interval variables. In this work, a new method for estimating the redundancy using interval structural analysis is developed. This method, hereafter referred to as Interval Redundancy Analysis (IRA), is robust and considers possibilities of strength reduction for each element leading to failure. Independent intervals for reduction of the strength for five damage scenarios of intact, slightly damage, moderately damaged, severely damaged, and completely damaged as well as strength of each element are considered. A numerical example to show the behavior of the developed method with comparison to Monte-Carlo simulation results is presented.
M.S. in Civil Engineering, May 2014
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Title: Development and Application of an Occupational Odor Hazard Index
Creator: Wang, Tingting
Date: 2011-04-24, 2011-05
Description: Odors emitted from wastewater treatment and sludge processing facilities may lead to employee complaints regarding discomfort, stress or...
Show moreOdors emitted from wastewater treatment and sludge processing facilities may lead to employee complaints regarding discomfort, stress or disease, and affect productivity and worker turnover in Water Reclamation Plants (WRPs). This study reports and assesses a comprehensive method that estimates the odor perception and associated hazards from exposures to odors in a post-digestion dewatering building in a WRP and its vicinity areas. An Odor Reference Concentration (ORfC) is developed as an index of acceptable odor level. This index is applied to ensure that the majority of building occupants (80 percent or more) do not perceive the odor. This index is developed to fill the lack of a uniform standard and method to assess hazard of exposed individuals to odors in occupational environments and to regulate odor exposures.
A comprehensive odor and odorant concentration database was formulated by a monitoring study in the occupational environment of a post-digestion dewatering building. The presence of odorants in the building are at concentrations below occupational exposure limits but higher than odor detection threshold values. This finding indicates that reducing odorant concentrations below exposure limits does not assure an odor-free environment. A model is formulated and validated for this dewatering building associating odor perception with concentrations of total sulfur compounds and relative humidity and is used for prediction of indoor odor concentrations under various conditions. Odor and odorant emission rates as the strength of sources are input variables of the indoor air quality model. In this study, odor and odorant emission rates from freshly dewatered biosolids in a dewatering building were measured using two widely used dynamic methods: the USEPA flux chamber and wind tunnel, and results from the two methods are not significantly different. Comparison of the two methods indicates that both methods can be used to estimate odor and odorant emission rates but the most effective and efficient method depends on prevailing environmental conditions. The ORfC established based on the comprehensive odor and odorant concentration database for this dewatering building is 13D/T (dilution to threshold). This index is used to evaluate seven control strategies recommended to reduce odor levels. If indoor odor concentrations in the occupational environment exceed the ORfC, then the hazard of odor exposures is unacceptable. Deterministic results of this study indicate that if appropriate control strategy is applied, odor concentration in the dewatering building would reach to below levels that cause unnecessary stress and other effects. The control strategy focus of this work is reduction of the indoor odor perception. But indoor control strategies must not cause outdoor odor problems to surrounding residential areas. Therefore, the potential impact of the control strategy recommended is also investigated in this thesis using the US EPA recommended air dispersion modeling AERMOD. Predictions of hydrogen sulfide concentrations at surrounding areas of the plant indicate that only one strategy, which proposes to add a new exhaust system in the dewatering building, would cause the ambient hydrogen sulfide concentration to be 7% higher than the odor detection threshold; other six strategies would not induce odor annoyance to surrounding areas. Acute and long-term ambient hydrogen sulfide exposure limits based on human health and irritation effects would not be violated under any of the seven control strategies.
Ph.D. in Environmental Engineering, May 2011
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Title: NSF Annual Report 2012 on Flexible Decision-making in Response to Disruptive Events on Construction Sites
Creator: Menches, Cindy L., Chen, Juan
Date: 2012-06-29, 2012-06-29
Description: This 2012 annual research report submitted to the National Science Foundation describes: (1) involved people, (2) research activities, (3)...
Show moreThis 2012 annual research report submitted to the National Science Foundation describes: (1) involved people, (2) research activities, (3) research findings, (4) training and development, (5) outreach activities, (6) publications, and (7) contributions for rant number CMMI-1100514, Flexible Decision-making in Response to Disruptive Events on Construction Sites.
Sponsorship: National Science Foundation Award Number: CMMI-1100514
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Title: PIEZO-BARKHAUSEN PULSE SIGNAL ANALYSES (BPSA) AND DETERMINATION OF THE FATIGUE LIFE OF AISI-1018 STEEL NEAR THE ENDURANCE LIMIT
Creator: Nunez-moreno, Federico Alejandro
Date: 2014, 2014-05
Description: A series of fatigue tests were performed on two different types of steels named Steel A (annealed and decarbed AISI-1018 steel), and Steel B ...
Show moreA series of fatigue tests were performed on two different types of steels named Steel A (annealed and decarbed AISI-1018 steel), and Steel B (annealed and polished AISI-1018 steel), carried out to separation or to a maximum of 10,000,000 cycles (which was taken to be equivalent to infinite life). Strain levels ranging from 0.0014 in/in (0.0014mm/mm) down to 0.0008in/in (0.0008mm/mm) were used to execute all experimental load tests at a stress ratio R=-1 (complete reversal). An MTS machine was used for these trials. At the same time, magnetic fields and piezo-Barkhausen pulses were recorded by means of a flux gate magnetometer and a copper coil connected to a series of signal filters and amplifiers. Results were used to construct the classical S-N Whöler curve for both steels, as well as in exhibiting the behavior of the magnetic parameters (magnetic excursions, dominant frequencies of the magnetic signals) coupled to the fatigue lives of the samples tested. To describe such couplings, a set of correlations were introduced among the monitored variables as functions of testing time and applied strain. Also, a fractography analysis of the crack patterns using a scanning electron microscope was performed to represent statistically the geometry of “dimples” and fatigue striations from the inception of the crack, until the formation of a shear lip at the final stages of the crack. It was found that the magnitude of the mean amplitude of the piezo-Barkhausen pulses at early stages of the test is correlated to a mid-level energy of cracking, and thus explains the geometry of fatigue striations near the initiation of the crack at higher strain levels, compared to the geometry of the fatigue striations at lower strain levels. x xvi A joint analysis of the amplitudes of the magnetic excursions recorded in time, and the dominant frequencies of the magnetic signals were found to be discriminators of the elastic and plastic behavior of both types of steel. Furthermore the observed magnetic parameter variations determined in a clear way the endurance limit for each type of steel; these values also are in agreement with the strain level for which fatigue lives were greater than 10,000,000 cycles. Based on these results a “bell analogy” for interpreting the fatigue behavior is introduced. Bridge engineering applications and further research is also discussed.
PH.D in Civil Engineering, May 2014
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Title: CYBER-PHYSICAL SYSTEM FOR A WATER RECLAMATION PLANT: BALANCING AERATION, ENERGY, AND WATER QUALITY TO MAINTAIN PROCESS RESILIENCE
Creator: Zhu, Junjie
Date: 2015, 2015-07
Description: Aeration accounts for a large fraction of energy consumption in conventional water reclamation plants (WRPs). Although process operations at...
Show moreAeration accounts for a large fraction of energy consumption in conventional water reclamation plants (WRPs). Although process operations at older WRPs can satisfy effluent permit requirements, they typically operate with excess aeration. More effective process controls at older WRPs can be challenging as operators work to balance higher energy costs and more stringent effluent limitations while managing fluctuating loads. Therefore, understandings of process resilience or ability to quickly return to original operation conditions at a WRP are important. A state-of-art WRP should maintain process resilience to deal with different kinds of perturbations even after optimization of energy demands. This work was to evaluate the applicability and feasibility of cyber-physical system (CPS) for improving operation at Metropolitan Water Reclamation District of Greater Chicago (MWRDGC) Calumet WRP. In this work, a process model was developed and used to better understand the conditions of current Calumet WRP, with additional valuable information from two dissolved oxygen field measurements. Meanwhile, a classification system was developed to reveal the pattern of historical influent scenario based on cluster analysis and cross-tabulation analysis. Based on the results from the classification, typical process control options were investigated. To ensure the feasibility of information acquisition, the reliability and flexibility of soft sensors were assessed to typical influent conditions. Finally, the process resilience was investigated to better balance influent perturbations, energy demands, and effluent quality for long-term operations. These investigations and evaluations show that although the energy demands change as the influent conditions and process controls, in general, aeration savings could be up to 50% from the level of current consumption; with a more xix complex process controls, the saving could be up to 70% in relatively steady-state conditions and at least 40% in relatively challenging transient conditions. The soft sensors can provide reliable and flexible performance on target predictions. The plant can still maintain at a similar level of process resilience after 50% aeration saving, even during long-term perturbations. Overall, this work shows that it is well feasible to provide more cost-effective operations at the Calumet WRP, and meanwhile influent perturbations, effluent quality, and process resilience are well in balance. Keywords: Energy, aeration, effluent quality, perturbation, resilience, water reclamation plant.
Ph.D. in Environmental Engineering, July 2015
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Title: Using ecological momentary assessment to understand a construction worker’s daily disruptions and decisions (Working Paper)
Creator: Menches, Cindy L., Chen, Juan
Date: 2012-06-01, 2012-06-01
Description: Capturing the momentary decisions and actions made by construction workers in response to workflow disruptions is challenging because, until...
Show moreCapturing the momentary decisions and actions made by construction workers in response to workflow disruptions is challenging because, until now, there has not been a minimally-disruptive data collection method that allows workers to identify their decision process “in the moment.” However, an Ecological Momentary Assessment (EMA) method – designed to capture momentary work experiences in natural settings – can provide researchers with detailed information about the daily challenges experienced by workers during the course of performing their tasks. An explanation of the method is provided, along with examples of the types of research questions that can be addressed and appropriate analysis techniques. The EMA method is being used on a federally-funded research program in the United States that is investigating how construction workers adapt to workflow disruptions by improvising their decisions and actions. Consequently, this article demonstrates the use of the method by presenting an idiographic study of William, an electrical construction worker. The evaluation of William’s disruptions, decisions, and actions elucidated an important relationship: every one of William’s disruptions required an improvisational action in order to continue working. The EMA method opens the door to the development of new theories about rapid decisions and subsequent actions on construction sites.
Sponsorship: National Science Foundation
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Title: ORGANIZATIONAL FLEXIBILITY IN CONSTRUCTION COMPANIES
Creator: Taghizadeh Khamesi, Hossein
Date: 2016, 2016-05
Description: Flexibility is a key factor for an organization survival in a changing environment. Considering the cyclical nature of construction demand,...
Show moreFlexibility is a key factor for an organization survival in a changing environment. Considering the cyclical nature of construction demand, organizational flexibility is of special importance in construction company management. Most previous studies tried to categorize the response strategies of construction contractors to business and environmental changes. However, there is gap in the literature about the dynamic effect of organizational flexibility on the growth and competitiveness in construction companies. The objective of this study is to investigate the organizational flexibility of top construction contractors in the U.S. Engineering News-Records (ENR) top 400 contractors lists were used to collect data for the 52-year period 1963-2015. Using the collected data, several analyses were performed to find the relationship between organizational flexibility and competitive success. This attempt did not indicate a distinct relationship between organizational flexibility and competitiveness. It was found however that organizational flexibility is affected by change in the economy and that it was linked to company expansion/contraction. It is concluded that organizational flexibility is an essential advantage for construction contractors. Those contractors that are consistently ranked in the top 400 contractors list respond well to economic changes by expanding and contracting. On the other hand, different size contractors respond to changes in the economy differently, based on their resources and the nature of their work. In addition, this study concluded that those contractors that seek high growth rates face more fluctuations in their growth path and need more flexibility in response to them.
M.S. in Civil Engineering, May 2016
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Title: AN INTRINSICALLY CONDUCTING POLYMER-BASED COATING SYSTEM FOR CORROSION PROTECTION OF STEELS
Creator: Yu, Qifeng
Date: 2016, 2016-12
Description: Among the various corrosion protection strategies for structural steels, coating techniques provide the most cost-effective protection and...
Show moreAmong the various corrosion protection strategies for structural steels, coating techniques provide the most cost-effective protection and have been used as the primary mode for corrosion protection. Existing coating techniques have been used mainly for their barrier capability and all have a limited service life. In this research work, a waterborne two-strand polyaniline: poly (acrylic acid) complex was synthesized and utilized to fabricate the primer layer of a two-layer coating system. The techniques of Scanning Kelvin Probe Force Microscopy (SKPFM) and Electrochemical Impedance Spectroscopy (EIS) were used to evaluate the anti-corrosion capability of the polymeric complex when mixed in an epoxy matrix and coated on steel samples as the primer layer. The evaluation results show that coating systems including a PANi-based primer has measurable anticorrosion capability and the anti-corrosion capability of PANi-based primer depends on the usage of PANi and the type of matrix material of the primer layer. In the laboratory condition, a prototype two-layer coating system including the PANi-based primer and a polyurethane topcoat was manufactured. The ASTM Salt-Spray Test and EIS were used to prove the anti-corrosion performance of the prototype using a two-layer, polyurethane-over-epoxy system (no PANi) as the control system. After the proof of concept, a non-waterborne epoxy was used to fabricate a different PANi-based primer. The two types of primers and two other commercial primers (a zinc-rich primer and an epoxy-only primer) were used to make a total of eight two-layer coating systems using two widely used topcoats. Salt-Spray Test, Cyclic Salt Fog/UV Exposure Test, Pull- Off Adhesion Test, and the techniques of EIS, SKPFM, and Scanning Electron Microscope (SEM) were used to evaluate the long-term performance of the eight systems. Based on the laboratory-based recommendations, six groups of two-layer coating systems were then subjected to the outdoor-exposure test to evaluate their anti-corrosion durability at two testing sites. The field durability of the coating systems was evaluated in terms of their surface gloss reduction, color change, adhesion change and surface deteriorations. The matrix material in which the PANi is mixed plays an important role in the longterm anti-corrosion performance of coatings. The waterborne epoxy is effective in dispersing PANi nano-particles and has zero VOC; however, it does not bond to the steel surface as strongly as the regular non-waterborne epoxy. The topcoat material also plays an important role in the long-term anti-corrosion performance of coatings; polyurethane has higher durability than epoxy as a topcoat material. The PANi-based systems possess long-term corrosion protection comparable to the performance of the conventional zincrich three-layer system based on the one-year field evaluation.
Ph.D. in Civil Engineering, December 2016
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Title: AUTOMATED PROGRESS CONTROL USING LASER SCANNING TECHNOLOGY
Creator: Zhang, Chengyi
Date: 2013, 2013-05
Description: Assessing progress in different construction activities at the end of every payment period is time consuming and requires specialized...
Show moreAssessing progress in different construction activities at the end of every payment period is time consuming and requires specialized personnel employed by the contractor and the owner. Automatic progress control that requires a minimum amount of human involvement could reduce the time spent on this activity, reduce the number of personnel used, reduce the cost involved, reduce disagreements between contractor and owner, and add to the overall efficiency of project management. Attempts have been made in the past to resolve this issue using image processing and other techniques but the results have not been satisfactory. A new attempt was made to set up a system that can assess progress control with minimum human input and the results are presented in this paper. The experiment made use of laser scanning technology and was conducted both in laboratory conditions and construction sites. The initial results from laboratory condition appear to be promising but there are still obstacles to surmount. The system is robust and accurate in laboratory conditions and constitutes proof of concept. Improvements are made to accelerate the registration process of multiple scans, to reduce the noise data, to recognize objects of irregular shape, and to assess the practicality and economic feasibility of such a system when applying this system in real construction sites. Keywords: Construction scheduling, progress control, laser scanning
PH.D in Civil Engineering, May 2013
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Title: Water power development at Iowa Falls, Iowa
Creator: Dowdell, Charles O.
Date: 2009, 1907
Publisher: Armour Institute of Technology
Description: http://www.archive.org/details/waterpowerdevelo00dowd
Thesis (B.S.)--Armour Institute of Technology; Bibliography: leaf 12

Title: LONG-TERM AEROBIC AND ANAEROBIC TRANSFORMATIONS OF ORGANIC MATTER IN ANAEROBICALLY DIGESTED BIOSOLIDS
Creator: Lukicheva, Irina
Date: 2012-12-05, 2012-12
Description: Long-term anaerobic storage of biosolids in a lagoons type of system as a post-treatment to anaerobic digestion is a proven process for...
Show moreLong-term anaerobic storage of biosolids in a lagoons type of system as a post-treatment to anaerobic digestion is a proven process for further pathogen reduction to produce Class A biosolids. At the same time, final biosolids product could develop odors during storage and handling, limiting the flexibility of biosolids utilization. The goal of this research was to study properties of biosolids under different lengths of aging time to determine the stability of final product for its odor potential. Field lagoons of Metropolitan Water Reclamation District of Greater Chicago were sampled to estimate the spatial and temporal variations in the physical-chemical properties and biological stability indicators, namely, total solids, volatile solids, pH, electric conductivity, total Kjeldahl nitrogen, ammonia-N, nitrite/nitrate-N, accumulated oxygen uptake for the 20-hour respirometric test, soluble protein concentration and headspace concentrations of volatile sulfur compounds. The sampling campaign was performed in October 2009. Two types of lagoons were assessed in this study- high-solids lagoons that are loaded with sludge that was previously anaerobically digested and dewatered on the centrifuges, and low-solids lagoons that are loaded with sludge that was previously digested but not dewatered. The analysis of collected data suggested that for the high-solids lagoons the surface layer biosolids (depth of above 0.15 m) undergo long-term aerobic oxidation resulting in higher degree of final product stabilization. The subsurface layers (depth below 0.15 m) are subjected to anaerobic environment where the conditions allow only the initial rapid organic matter degradation approximately within the first year, followed xii by very slow degradation. In addition, microbiological analyses using Fluorescent in situ Hybridization did not indicate active microbial communities in aged biosolids. The performance of low-solids lagoons in the reduction of the biodegradability parameters was shown to be similar to that of the high-solids lagoons. Low-solids lagoons were shown to perform the dewatering function reducing moisture in the digested sludge from initial 2-3% TS to up to 16% TS. Although the lagoon aged biosolids were found to be stable in comparison with other products, such as composts, further aerobic processes taking place after lagoons, such as air-drying and stock-piling could induce further active biological activity. This could potentially result in the odor formation from the air-dried final product. For these reasons, more research is required on the mechanisms promoting further product degradation after lagoons aging.
PH.D in Environmental Engineering, December 2012
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Title: IMPROVEMENT OF BUS TRANSIT OPERATIONS BY MINIMIZING NON-REVENUE TRAVEL TIME
Creator: Arthur, Christina
Date: 2012-06-04, 2012-07
Description: There are many activities in which a transit agency can investigate reduce costs. Three main activities include service cuts, renegotiations...
Show moreThere are many activities in which a transit agency can investigate reduce costs. Three main activities include service cuts, renegotiations of union labor contracts and modifications to bus operations. The first activity, cutting service, is often a last resort because not only must an agency adhere to its budget but also its service standards. Service cutting can involve route eliminations, stop eliminations, reroutes and reductions in spans of service and frequency of service. These service cuts greatly impact the riders in which routes serve as well as the image of the agency. In order to maintain customer satisfaction and ridership, an agency may decide to employ the latter two activities. In essence these two types of activities, singularly or in combination, can produce a reduction in overhead costs to the agency by more efficiently operating services. This paper focuses on modifications to bus operations as it relates to pull-in and pull-out trips, commonly referred to as deadheading and operator travel to relief points. Using the urban bus operation of the Chicago Transit Authority, a model is developed to assign routes to garages given the locations of the pull-in and pull-out locations associated with each route. As the system currently exists, there are seven garages distributed across the city from which 144 bus routes start and end. Many of these routes are operated out of multiple garages. The main reason for these route-to-multi-garage assignments is garage capacity and scheduling needs. The goal of this research is to determine how routes can be assigned to one specific garage and still meet the requirements given by the schedule.
M.S. in Civil Engineering, July 2012
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Title: ADVANCING DESIGN SIZING AND PERFORMANCE OPTIMIZATION METHODS FOR BUILDING INTEGRATED THERMAL AND ELECTRICAL ENERGY GENERATION SYSTEMS
Creator: Zakrzewski, Thomas
Date: 2017, 2017-07
Description: Combined electrical and thermal energy systems (i.e., cogeneration systems) will play an integral role in future energy supplies because they...
Show moreCombined electrical and thermal energy systems (i.e., cogeneration systems) will play an integral role in future energy supplies because they can yield higher overall system fuel utilization and efficiency, and thus produce fewer greenhouse gas emissions, than traditionally separate systems. However, methods for both design sizing and performance optimization for cogeneration systems and commercial buildings lag behind the tremendous advancements that have been made in building performance simulation methods. Therefore, the overall goal of this research is to develop and apply novel cogeneration system modeling techniques for optimizing design sizing and dispatch of generation sets that reduce energy use, energy costs, and greenhouse gas emissions. This research is divided into four main research objectives: (1) generalizing cogeneration performance of lean burn natural gas spark ignition reciprocating engines, (2) developing a new Design and Optimization of Combined Heat and Power (DOCHP) systems optimization tool for improving design-sizing of building-integrated and grid-tied CHP systems, (3) demonstrating the utility of the DOCHP tool with several practical applications, and (4) integrating on-site intermittent renewable energy systems into the DOCHP tool to analyze micro-grid applications. This research leverages recent developments in multiple areas of building and system simulation methods. DOCHP advances design sizing and performance optimization methods for building integrated thermal and electrical energy generation systems through the application of an evolutionary artificial intelligence-based genetic algorithm and its ability to resolve to non-linear optimization with discrete constraints while considering non-linear part-load generation set performance curves.
Ph.D. in Civil Engineering, July 2017
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Title: TASK/STAFFING-TECHNOLOGY FIT IN CONSTRUCTION SCHEDULING
Creator: Yang, Juneseok
Date: 2015, 2015-07
Description: Construction managers use scheduling methods such as the critical path method (CPM) and linear scheduling methods (LSM) to improve the outcome...
Show moreConstruction managers use scheduling methods such as the critical path method (CPM) and linear scheduling methods (LSM) to improve the outcome of their project. CPM is a popular scheduling method that is mostly based on precedence relationships and the identification of the longest path through a network. LSMs are based on a continuous flow of resources and are used mostly on projects that exhibit repetitive characteristics. Despite the many obvious advantages of CPM, its use in construction has been limited. LSMs are much less frequently used than CPM, although the general consensus is that LSMs are quite effective in projects composed of activities of repetitive nature. Understanding the reasons why these methods are not used as extensively as expected could improve their level of acceptance in the construction industry. The link between construction scheduling methods and the tasks expected to be performed by schedulers has been an on-going concern in the construction industry. The link between construction scheduling methods and the capabilities of the scheduling staff has also been an important issue. This study proposes a combined task/staffing-technology fit model to understand why CPM and LSM are not used as extensively as expected in construction scheduling: (1) a task-technology fit model that aims to measure the extent to which a construction scheduling method functionally matches the tasks expected to be performed by the scheduling staff; (2) a staffing-technology fit model that aims to measure the extent to which a construction scheduling method matches the staff`s experience, know-how and capabilities. The models that are proposed are an answer to the lack of proper instruments for evaluating the extent to which scheduling methods are used in the industry. A questionnaire survey was administered to professionals listed in the directory of the Construction Management Association of America (CMAA) who have many years of experience in construction scheduling. Statistical analyses were performed to determine statistical significance of the differences between the level of agreement concerning task-technology fit and staffing-technology fit for CPM and LSM applications. Findings indicate that there are significant differences between the opinions of CPM users and LSM users. This means that task-technology fit is much different in CPM and LSM applications. Similarly, staffing-technology fit is also quite different in CPM and LSM applications.
M.S. in Civil Engineering, July 2015
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