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(501 - 520 of 4,268)
Pages
- Title
- Diffraction at the LHC, Proceedings of the XLIII International Symposium on Multiparticle Dynamics
- Creator
- Csanád, M.
- Date
- 2013-09-15, 2013-09-15
- Publisher
- IIT Press
- Description
-
Proton-proton collisions at the LHC can be classified as elastic, non-diffractive, and diffractive. In this paper we discuss various...
Show moreProton-proton collisions at the LHC can be classified as elastic, non-diffractive, and diffractive. In this paper we discuss various measurements of these above processes at various LHC experiments. We report about the total proton-proton cross-section measurements, about the analysis of diffractive events and also about the pseudorapidity distribution in inelastic events.
Sponsorship: IIT College of Science, High Energy Physics Division of Argonne National Laboratory
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- Title
- INCORPORATING REACTIVE POWER MARKET INTO THE DAY-AHEAD ELECTRICITY MARKET
- Creator
- Al Ghamdi, Mohammed
- Date
- 2012-05-29, 2012-07
- Description
-
The research work presented in this thesis proposes the incorporation of the reactive power market into the day-ahead electricity market in...
Show moreThe research work presented in this thesis proposes the incorporation of the reactive power market into the day-ahead electricity market in order to compensate generation companies (GENCOs) and independent power producers (IPPs) for providing any additional reactive power support, which varies on an hourly basis based on the load demand, transmission network configuration, and any contingencies that might occur. This proposal would minimize the total payment burden on the independent system operator (ISO), which is related to the reactive power dispatch. The proposed model achieves the main objective of an ISO in a competitive electricity market, which is to provide the required reactive power support from generators at minimum cost while ensuring the secure operation of the power system. In this research, the reactive power price is the bidding-based price that is submitted by the GENCOs and IPPs to the ISOs during the day-ahead market. The proposal takes into the account both the technical and economic aspects associated with the active power and reactive power dispatch in the context of the new operating paradigms in competitive electricity markets. In this research, the Security Constrained Unit Commitment (SCUC) based on AC power flow modeling is considered as the drive engine for clearing the day-ahead electricity market based on the amount of information provided by the market participants. This proposed framework would provide appropriate reactive power support from service providers at minimum cost, while ensuring the secure and reliable operation of the electrical power system. In the research, the PQ capability curves of the generating units are modeled to ensure the practically of the SCUC solutions that are obtained. This proposal would be an essential step toward a fair electricity market while increasing the security of the power system and reducing transmission congestions. Also, it would pave the road for various renewable energy resources since the penetration of renewable energy resources would impact the commitment of the generating units. This would impact the available reactive power reserve margin and security of the network. In addition, incorporating the reactive power market into the day-ahead market would provide a clear signal for optimal private investment in the reactive power capacity. The framework that has been developed is general in nature and can be used for any electricity market structure.
Ph.D. in Electrical Engineering, July 2012
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- Title
- Low-energy exclusive cross sections and inclusive production of identified charged hadrons with Babar, Proceedings of the XLIII International Symposium on Multiparticle Dynamics
- Creator
- Gary, J. William
- Date
- 2013-09-15, 2013-09-15
- Publisher
- IIT Press
- Description
-
Recent measurements of exclusive hadronic cross sections from the Babar Collaboration at SLAC are presented. Specifically, we present results...
Show moreRecent measurements of exclusive hadronic cross sections from the Babar Collaboration at SLAC are presented. Specifically, we present results on the e⁺e⁻ → K⁺K⁻(γ), p̅p, KₛKₗ, KₛKₗπ⁺π⁻ , KₛKₛπ⁺π⁻, and KₛKₛK⁺K⁻ cross sections performed using events with initial-state photon radiation, which allows the cross sections to be measured at low energy and over an extended energy range. In addition, we present results on the inclusive momentum spectra of identified charged pions, kaons, and protons at the fixed center-of-mass energy of 10.54 GeV, allowing new tests of QCD.
Sponsorship: IIT College of Science, High Energy Physics Division of Argonne National Laboratory
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- Title
- A study of the corrosion of locomotive boiler tubes
- Creator
- Congdon, Charles C.
- Date
- 2009, 1915
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/studyofcorrosion00cong
Thesis (B.S.)--Armour Institute of Technology; Bibliography: leaves 36-37
- Title
- INVESTIGATION OF NIOBIUM SURFACE STRUCTURE AND COMPOSITION FOR IMPROVEMENT OF SUPERCONDUCTING RADIO-FREQUENCY CAVITIES
- Creator
- Trenikhina, Yulia
- Date
- 2014, 2014-12
- Description
-
Nano-scale investigation of intrinsic properties of niobium near-surface is a key to control performance of niobium superconducting radio...
Show moreNano-scale investigation of intrinsic properties of niobium near-surface is a key to control performance of niobium superconducting radio-frequency cavities. Mechanisms responsible for the performance limitations and their empirical remedies needs to be justified in order to reproducibly control fabrication of SRF cavities with desired characteristics. The high field Q-slope and mechanism behind its cure (120◦C mild vacuum bake) were investigated by comparison of the samples cut out of the cavities with high and low dissipation regions. Material evolution during mild field Q-slope nitrogen treatment was characterized using the coupon samples as well as samples cut out of nitrogen treated cavity. Evaluation of niobium near-surface state after some typical and novel cavity treatments was accomplished. Various TEM techniques, SEM, XPS, AES, XRD were used for the structural and chemical characterization of niobium near-surface. Combination of thermometry and structural temperature-dependent comparison of the cavity cutouts with different dissipation characteristics revealed precipitation of niobium hydrides to be the reason for medium and high field Q-slopes. Step-by-step effect of the nitrogen treatment processing on niobium surface was studied by analytical and structural characterization of the cavity cutout and niobium samples, which were subject to the treatment. Low concentration nitrogen doping is proposed to explain the benefit of nitrogen treatment. Chemical characterization of niobium samples before and after various surface processing (Electropolishing (EP), 800◦C bake, hydrofluoric acid (HF) rinsing) showed the differences that can help to reveal the microscopic effects behind these treatments as well as possible sources of surface contamination.
Ph.D. in Physics, December 2014
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- Title
- Chicago Politicians on Twitter
- Creator
- Hemphill, Libby, Shapiro, Matthew A., Otterbacher, Jahna
- Date
- 2012-03-12, 2012-03-12
- Description
-
This paper uses data from 1,042 tweets posted by or mentioning Chicago Aldermen or Mayor Rahm Emanuel to examine how Chicago politicians use...
Show moreThis paper uses data from 1,042 tweets posted by or mentioning Chicago Aldermen or Mayor Rahm Emanuel to examine how Chicago politicians use social media. Twitter provides a public communication medium in which constituents and their representatives can have two-way conversations that others can witness and record, and we used qualitative and social network methods to examine conversations between Chicagoans and representatives in city government. We coded the contents of each tweet over the two-week time period (e.g., official business, fundraising) and created representations of the social networks created by the users’ following behaviors. These networks indicate who receives politicians’ tweets and help identify the audiences for political messaging in social media. Our analysis indicates that Chicago’s Aldermen and Mayor use Twitter for social conversations more often than political ones, and that only a small number of Aldermen dominate the resulting conversation networks.
Sponsorship: Social Network Research Group at IIT, IIT Graduate College
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- Title
- A HARDWARE-IN-THE-LOOP SOFTWARE-DEFINED NETWORKING TESTING AND EVALUATION FRAMEWORK
- Creator
- Yang, Qi
- Date
- 2017, 2017-05
- Description
-
The transformation of innovative research ideas to production systems is highly dependent on the capability of performing realistic and...
Show moreThe transformation of innovative research ideas to production systems is highly dependent on the capability of performing realistic and reproducible network experiments. Simulation testbeds o↵er scalability, reproducibility but lack fidelity due to model abstraction and simplification, while physical testbeds o↵er high fidelity but lack reproducibility and often technically challenging and economically infeasible to perform large-scale experiments. In this work, we present a hybrid testbed consisting of container-based network emulation and physical devices to advocate high fidelity and reproducible networking experiments. In particular, the testbed integrates network emulators (Mininet) [5], a distributed control environment (ONOS) [1], physical switches (Pica8) and end-hosts (Raspberry Pi and commodity servers). The testbed (1) o↵ers functional fidelity through unmodified code execution on an emulated network, (2) supports large-scale network experiments using lightweight OS-level virtualization techniques and capable of running across distributed physical machines, (3) provides the topology flexibility, and (4) enhances the repeatability and reproducibility of network experiments. We validate the fidelity of the hybrid testbed through extensive experiments under di↵erent network conditions (e.g., varying topology and traffic pattern), and compare the results with the benchmark data collected on physical devices.
M.S. in Computer Science, May 2017
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- Title
- EXPLOITING NETWORK CODING IN DIFFERENT WIRELESS NETWORKS
- Creator
- Guo, Bin
- Date
- 2012-07-06, 2012-07
- Description
-
Wireless communication networks have been incorporated into our daily life and provide convenience anytime and anywhere. However, the wireless...
Show moreWireless communication networks have been incorporated into our daily life and provide convenience anytime and anywhere. However, the wireless medium is unreliable and unpredictable. Current wireless networks suffer from low throughput, low reliability, etc. Network coding, an alternative approach, has attracted more interests and has emerged as an important technology in wireless networks. It can provide significant potential throughput improvements and a high degree of robustness. This dissertation is built on the theory of network coding. In this dissertation, different network coding protocols are designed in varied wireless networks. The first part of this dissertation proposes a novel coding-ware routing protocol in wireless mesh networks. In particular, a generalized coding condition is formally established to identify the coding opportunities. Based on general coding conditions analysis, a novel routing metric FORM (Free-ride Optimal Routing Metric) and the corresponding routing protocol are developed with the objective to exploit the coding opportunities and maximize the benefit of “free-ride” in order to reduce the total number of transmissions and consequently to increase the network throughput. The results show the proposed protocol achieves significant throughput gain than existing approaches. The second part of this dissertation exploits network coding in wireless cooperative networks. Firstly, a Decode-and-Forward Network Coded (DFNC) protocol is proposed for multi-user cooperative communication system. In particular, DFNC develops an efficient construction method for coding coefficients and a novel decoding algorithm that combines network coding and channel coding. DFNC exploits both temporal and spatial diversities through multiple channels by allowing all the users to generate redundant network-coded packets in a distributed manner and it helps fully explore the redundancy provided by network coding to realize error correction. Theoretical analysis and simulation results demonstrate that DFNC outperforms other transmission schemes in terms of Symbol Error Rate (SER) and achieves higher diversity order. Secondly, the idea of DFNC is extended and Modified-DFNC (M-DFNC) is introduced for a more practical scenario: not all the users will be able to dedicate their resources to provide assistance for others. The throughput analysis shows that M-DFNC outperforms the conventional cooperative protocol in the low-SNR regime and it implies that an adaptive cooperation system should be adopted to optimize the performance. The simulation results validate the theoretical analysis.
Ph.D. in Electrical Engineering, July 2012
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- Title
- Control of grade transitions in distributed chemical reactor networks - An agent-based approach
- Creator
- Tetiker, M. Derya, Artel, Arsun, Teymour, Fouad, Cinar, Ali
- Date
- 2008-09-26
- Publisher
- PERGAMON-ELSEVIER SCIENCE LTD
- Description
-
Supervision of distributed manufacturing processes producing different grades of a product requires intelligent reconfiguration strategies...
Show moreSupervision of distributed manufacturing processes producing different grades of a product requires intelligent reconfiguration strategies during grade transition phases to minimize off-spec production. Agent-based approaches are ideal for such problems and they provide flexible, robust, and emergent solutions during dynamically changing process conditions. Three different multi-layered multi-agent, frameworks are proposed for the supervision of grade transitions in autocatalytic reactor networks. The first framework is the centralized framework and it is useful for small-scale grade transitions where only a small region of the network needs to be reconfigured. Alternatively, the other two frameworks use a decentralized approach. The first decentralized framework implements genetic algorithms and the second one uses self-organizing heuristics and auctions for large-scale grade transitions. The case studies demonstrate that as the complexity of the reconfiguration problem increases, decentralized solutions perform more efficiently.
Endnote format citation for DOI:10.1016/j.compchemeng.2008.02.008
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- Title
- A COMPARATIVE-STUDY OF TOOLS FOR ASSESSING THE EFFECTS OF FORCED PERIODIC OPERATION OF CATALYTIC REACTORS
- Creator
- Ozgulsen, F., Rigopoulos, K. R., Cinar, A.
- Date
- 1992
- Publisher
- GORDON BREACH SCI PUBL LTD
- Description
-
Two methods for assessing the effects of forced periodic catalytic reactor operation are presented. The vibrational control method is an...
Show moreTwo methods for assessing the effects of forced periodic catalytic reactor operation are presented. The vibrational control method is an analytical technique which evaluates the effects of high frequency forcing of system parameters by the method of averaging. The second technique is a numerical tool based on a shooting algorithm. These methods are capable of handling multiple input forcing and various shapes of forcing functions. Both methods are applied to isothermal, adiabatic and nonadiabatic operation of an internal recycle reactor in which the catalytic oxidation of ethylene takes place. The basic features of both techniques are discussed and the results obtained by using these methods are compared. Effects of single and multiple input parameter forcing are investigated. Experimental verification of the theoretical results is also performed for the isothermal case.
Endnote format citation
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- Title
- INVESTIGATION OF THE EFFICACY OF REACTIVE OXYGEN SPECIES GENERATED BY BOVINE AORTIC ENDOTHELIAL CELLS FOR INITIATING FREE-RADICAL POLYMERIZATION
- Creator
- Lu, Chenlin
- Date
- 2013, 2013-12
- Description
-
Reactive oxygen species are reported to be generated by bovine aortic endothelial cells during ischemia followed by reperfusion. This...
Show moreReactive oxygen species are reported to be generated by bovine aortic endothelial cells during ischemia followed by reperfusion. This biological response, believed to be the cause of post-ischemic reperfusion injury, inspired us to investigate the possibility of coupling it with the initiation of free-radical polymerization to produce polymer hydrogels for cell encapsulation. In this work, the generation of reactive oxygen species during ischemia and reperfusion was examined by fluorescence detection and the feasibility of initiating free-radical polymerization by generated reactive oxygen species was investigated in two sets of experiments. The generation of reactive oxygen species by bovine aortic endothelial cells when subjected to anoxia followed by reoxygenation was investigated in both attached and suspended cells. Both intracellular and extracellular generations of ROS appeared to occur in the experiments of attached cells. Cell viability experiments demonstrated that the generation of ROS was sufficient to cause cell damage and death. The feasibility of initiating free-radical polymerization by reactive oxygen species generated by bovine aortic endothelial cells subjected to anoxia followed by reoxygenation was investigated in two sets of experiments. One set involved the linear polymerization of NVP which allowed us to quantify the extent of polymerization and characterization of the weight conversion of PVP polymer. The other set involved the formation of PEGDA hydrogels which were characterized by imaging and staining methods. To our knowledge this is the first evidence of cell induced polymerization initiated by reactive oxygen species and gelation which can be used for a variety of biomedical applications.
M.S. in Chemical and Biological Engineering, December 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
- Study of the transmission of heat through tile and concrete fireproofing
- Creator
- Snow, C. A.
- Date
- 2009, 1912
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/studyoftransmiss00snow
Thesis (B.S.)--Armour Institute of Technology
- Title
- SUSTAINABLE MULTILINGUAL COMMUNICATION: MANAGING MULTILINGUAL CONTENT USING FREE AND OPEN SOURCE CONTENT MANAGEMENT SYSTEMS
- Creator
- Kelsey, Todd
- Date
- 2011-05-03, 2011-05
- Description
-
Multilingual content management systems, combined with streamlined processes and inexpensive organizational tools, make it possible for...
Show moreMultilingual content management systems, combined with streamlined processes and inexpensive organizational tools, make it possible for educators, non-profit entities and individuals with limited resources to develop sustainable and accessible multilingual Web sites. The research included a review of what’s been done in the theory and practice of designing Web sites for multilingual audiences. On the basis of that review, a series of sustainable multilingual Web sites were created, and a series of approaches and systems were tested, including MediaWiki, Plone, Drupal, Joomla, PHPMyFAQ, Blogger, Google Docs and Google Sites. There was also a case study on “Social CMS”, which refers to emergent social networks such as Facebook. The case studies are reported on, and conclude with high-level recommendations that form a roadmap for sustainable multilingual Web site development.
Ph.D. in Technical Communication, May 2011
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- Title
- Developing Web Applications for the Northern Illinois Hockey League (sequence unknown), IPRO 308 - Deliverables
- Creator
- Lucchesi, Kristin, Barksdale, Dustin, Hays, Julian, Bartus, Kryzystof, Perkins, William, Savage, Christopher, Scheer, Colin, Semenov, Vladimir, Vidutis, Mantas
- Date
- 2009-12
- Description
-
The NIHL is the largest hockey league in Illinois. It is also the largest youth all star hockey league in the US, serving over 300 youth teams...
Show moreThe NIHL is the largest hockey league in Illinois. It is also the largest youth all star hockey league in the US, serving over 300 youth teams and over 4,000 players. The team's purpose is to make the NIHL a web-based scheduling and scoring applications that can support their annual operations.
Sponsorship: Northern Illinois Hockey League(NIHL)
Deliverables for IPRO 308: Developing Web Applications for the Northern Illinois Hockey League for the fall 2009 semester
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- Title
- THERMAL RESISTANCE OF SALMONELLA ENTERICA AND ESCHERICHIA COLI 0157:H7 IN PEANUT BUTTER
- Creator
- He, Yingshu
- Date
- 2014, 2014-05
- Description
-
Salmonella enterica is a frequent food contaminant and the leading cause of foodborne bacterial illnesses in the United States. Our study...
Show moreSalmonella enterica is a frequent food contaminant and the leading cause of foodborne bacterial illnesses in the United States. Our study demonstrated that a 5-strain S. enterica cocktail displayed increased heat resistance in peanut butter of low water activity (aw). Significant differences (P < 0.05) were found between the survival rates of Salmonella enterica and Escherichia coli O157:H7 in peanut butter with different formulations and water activity. High carbohydrate content in peanut butter and low incubation temperature resulted in higher levels of bacterial survival during storage but lower levels of bacterial resistance to heat treatment. Furthermore, we also compared the relative heat resistance of three individual strains of S. enterica representing serotypes Typhimurium, Enteritidis and Tennessee and the 3-strain cocktail treated at both 90oC and 126oC in two different peanut butter formulations with varied fat and carbohydrate contents and adjusted water activities (aw from 0.2 to 0.8). When treated at 90oC, increased water activity in peanut butter significantly (P < 0.05) reduced the heat resistance of desiccation-stressed S. enterica cells. Differences in heat resistance were also detected among the three S. enterica serotypes and between the two peanut butter formulations. When treated at 126oC, the differences in bacterial heat resistance among serotypes and adjusted water activities were less notable (P > 0.05). Based on the Weibull model, an average of 52 to 132 min was required to achieve a 5-log reduction of the 3-strain cocktail at 90oC in peanut butter with an aw of 0.2. When aw was increased to 0.6, to achieve the same 5-log reduction required only 23-27 min. At aw of 0.8, S. enterica could be completely killed in less than 10 min in peanut butter with a fat content of 48.49%. Using scanning electron microscopy, we observed minor morphological changes xiii of S. enterica cells during desiccation and rehydration processes in peanut oil, which was used as a surrogate for peanut putter. Results from this study collectively suggest that water activity plays a critical role in determining S. enterica heat resistance in peanut butter. The variability that exists among the heat resistance of different S. enterica serotypes in different peanut butter formulations should also be taken into consideration for developing and validating effective intervention and mitigation strategies in peanut butter production.
PH.D in Biology, May 2014
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- Title
- Particle production at large momentum transfer, Proceedings of the XLIII International Symposium on Multiparticle Dynamics
- Creator
- Gonçalves, V.p., Sauter, Werner K.
- Date
- 2013-09-15, 2013-09-15
- Publisher
- IIT Press
- Description
-
Diffractive particle production in ep collisions and coherent pp interactions is studied assuming that the color singlet t channel exchange...
Show moreDiffractive particle production in ep collisions and coherent pp interactions is studied assuming that the color singlet t channel exchange carries large momentum transfer. The differential and total cross sections for vector meson and photon production are calculated using the non-forward solution of the LO and NLO BFKL equation at high energy and large momentum transfer and the predictions are compared with the DESY HERA data. Moreover, we estimate the rapidity distributions and total cross section for the J/Ψ and ρ production in coherent pp interactions at LHC energies. We predict large rates, which implies that the experimental identification can be feasible at the LHC.
Sponsorship: IIT College of Science, High Energy Physics Division of Argonne National Laboratory
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- Title
- Development of Powered Resonance-tube Actuators for Aircraft Flow Control Applications
- Creator
- Raman, G., Mills, A., Kibens, V.
- Date
- 2004-12
- Publisher
- American Inst Aeronaut Astronaut
- Description
-
The present paper addresses both active-flow-control actuator technology development and the demonstration of the effectiveness of actuators...
Show moreThe present paper addresses both active-flow-control actuator technology development and the demonstration of the effectiveness of actuators that could be easily integrated into practical aircraft applications. The actuator used is an adaptation of the Hartmann oscillator. Demonstration experiments that illustrate the effectiveness of this actuator include cavity tone suppression at transonic speeds and the reduction of jet-impingement tones. The actuator concept is based on a high-speed jet aimed at the mouth of a cylindrical tube closed at the other end. The result is a high-amplitude self-sustaining fluctuating field accompanied by an intense narrowband tone, all in the region between the supply jet and the resonance tube. Using unsteady pressure sensors and flow visualization, we explored the effect of varying actuator parameters such as the spacing between the power jet and the resonance tube, supply pressure, resonance-tube depth, diameter, shape, and lateral spacing. By varying the depth of the tube, the frequency could be varied from about 1.6 kHz to over 10 kHz and amplitudes as high as 156 dB (microphone location dependent) were obtained in the vicinity of actuation. To integrate this concept into practical aircraft applications, two generations of a more complex version of this device known as the powered resonance-tube bank (PRTB) were developed and demonstrated. Results indicate that by using high-frequency excitation at 5-kHz suppression levels in excess of 20 dB were consistently obtained over a range of operating conditions in both cavity and impingement flow situations. Based on our results, we have grounds to believe that a properly designed PRTB has significant advantages over conventional actuators such as acoustic, piezo, and oscillatory microstructures.
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- 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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