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Full-Text Articles in Engineering
Burrowing In Marine Muds By Crack Propagation: Kinematics And Forces, Sanjay Raja Arwade, Kelly M. Dorgan, Peter A. Jumars
Burrowing In Marine Muds By Crack Propagation: Kinematics And Forces, Sanjay Raja Arwade, Kelly M. Dorgan, Peter A. Jumars
Sanjay Raja Arwade
The polychaete Nereis virens burrows through muddy sediments by exerting dorsoventral forces against the walls of its tongue-depressor-shaped burrow to extend an oblate hemispheroidal crack. Stress is concentrated at the crack tip, which extends when the stress intensity factor (KI) exceeds the critical stress intensity factor (KIc). Relevant forces were measured in gelatin, an analog for elastic muds, by photoelastic stress analysis, and were 0.015±0.001 N (mean ± s.d.; N=5). Measured elastic moduli (E) for gelatin and sediment were used in finite element models to convert the forces in gelatin to those required in muds to maintain the same body …
Delay And Energy Tradeoff In Multi-State Wireless Sensor Networks, W. L. Leow, H. Pishro-Nik, Daiheng Ni
Delay And Energy Tradeoff In Multi-State Wireless Sensor Networks, W. L. Leow, H. Pishro-Nik, Daiheng Ni
Daiheng Ni
This paper discusses a first attempt to investigate, using analytic means, the transmission delay and energy char- acteristics of a multi-state wireless sensor network. For such a network with n nodes, where each node can be active, resting or sleeping, a model that describes the transition of a node from one state to another and the probability associated with each state is proposed. Asymptotic analyses of transmission delay and energy are presented. We report the presence of a threshold for the arrival rate of data packets that decides which energy component dominates. The transmission delay-energy tradeoff is presented for the …
Development Of A Prototype Intersection Collision Avoidance System Under Vii, Daiheng Ni, Hossein Pishro-Nik, Richa Prasad, Mohammed Raza Kanjee, Hui Zhu, Thai Nguyen
Development Of A Prototype Intersection Collision Avoidance System Under Vii, Daiheng Ni, Hossein Pishro-Nik, Richa Prasad, Mohammed Raza Kanjee, Hui Zhu, Thai Nguyen
Daiheng Ni
Vehicle collisions at in tersections account for a large percen tage of overall traffic accidents, a good portion of which are fatal. A large number of these accidents can be avoided by a warning system which makes a driver aware of potential collisions on the road, thus allowing the driver enough time to preven t such situations. This pape r presents the design of a prototype intersection collision warning system based on Vehicle Infrastructure Integration (VII). Underlying the system are wireless communications, positioning technology, and information technology that ensure accu rate and timely safety information.
Cation Exchange In Glacial Till Subjected To Highway Deicing Agent Infiltration, Niki Kallergis
Cation Exchange In Glacial Till Subjected To Highway Deicing Agent Infiltration, Niki Kallergis
Environmental & Water Resources Engineering Masters Projects
The site studied in this research project is owned by the Massachusetts Highway Department and has been used as a storage facility since the 1960's. The area has been characterized as a drumlin of glacial till composition. Improper storage practices occulTed during two decades (1960's - 1980's) by stockpiling deicing agents outdoors. Previous investigations verify groundwater contamination due to brine infiltration and establish several properties of the soil and the aquifer hydraulics. The chloride ion is unreactive and transported with groundwater molecules; however, field data and theory suggest that dissolved sodium partakes in cation exchange with sorbed cations on clay …
Modeling Fate And Transport Of Fecal Coliform In Wachusett Reservoir, Thomas P. Matthews
Modeling Fate And Transport Of Fecal Coliform In Wachusett Reservoir, Thomas P. Matthews
Environmental & Water Resources Engineering Masters Projects
The Wachusett Reservoir, located in central Massachusetts is an unfiltered, ozonated / chloraminated drinking water supply which serves 2.3 million customers in Boston, Massachusetts and surrounding communities. The Massachusetts Department of Conservation and Recreation (DCR) is responsible for managing and protecting the Wachusett Reservoir and surrounding watershed. The Massachusetts Water Resources Authority (MWRA) operates the water supply system and the Carroll Water Treatment Plant (CWTP). In addition, DCR manages and maintains the Quabbin Reservoir and watershed located in western Massachusetts. The Wachusett and Quabbin Reservoirs provide high quality water to consumers due to pristine watersheds and long hydraulic retention time. …
The Use Of Numerical Modeling Techniques To Optimize Groundwater Withdrawls And Minimize Streamflow Depletion, Yamen Hoque
The Use Of Numerical Modeling Techniques To Optimize Groundwater Withdrawls And Minimize Streamflow Depletion, Yamen Hoque
Environmental & Water Resources Engineering Masters Projects
Groundwater reserves can be a valuable resource in alleviating rising water demands worldwide. The groundwater is generally pumped out of surficial aquifers using withdrawal wells. However, unregulated groundwater withdrawals can impact the flow in nearby streams negatively, causing streamflow depletions. This can hinder the ecological balance of streams and endanger the aquatic life fonTIs that call such streams home. Therefore, groundwater withdrawals must be carried out using a well managed withdrawal strategy. Rhode Island has a growing annual water demand that has been projected to exceed current supply in parts of the state by 2020. As a result, several new …
The Use Of Numerical Modeling Techniques To Optimize Groundwater Withdrawls And Minimize Streamflow Depletion, Yamen M. Hoque
The Use Of Numerical Modeling Techniques To Optimize Groundwater Withdrawls And Minimize Streamflow Depletion, Yamen M. Hoque
Environmental & Water Resources Engineering Masters Projects
Groundwater reserves can be a valuable resource in alleviating rising water demands worldwide. The groundwater is generally pumped out of surficial aquifers using withdrawal wells. However, unregulated groundwater withdrawals can impact the flow in nearby streams negatively, causing streamflow depletions. This can hinder the ecological balance of streams and endanger the aquatic life fonTIs that call such streams home. Therefore, groundwater withdrawals must be carried out using a well managed withdrawal strategy. Rhode Island has a growing annual water demand that has been projected to exceed current supply in parts of the state by 2020. As a result, several new …
Evaluation Of Nutrients Along The Blackstone River, Megan M. Patterson
Evaluation Of Nutrients Along The Blackstone River, Megan M. Patterson
Environmental & Water Resources Engineering Masters Projects
The University of Massachusetts Blackstone River Water Quality Study was conducted in August of 2005 through November of 2006. Water quality was monitored throughout two dry weather events and five wet weather events along the Blackstone at over 20 sites from the headwaters downstream to Woonsocket, Rhode Island. Special emphasis was placed on the analysis of the nutrient loadings crossing the Massachusetts/Rhode Island state border. Continuous nitrate and phosphate readings were collected at the state line using MicroLABs. The MicroLAB results required a high degree of data adjustment; duplicate samples are recommended to ensure future data quality. Data from events …
Ground Water Management, Gwm, Formulations To Control Subsidence In A Large Scale Transient Problem, Gemma Baro-Montes
Ground Water Management, Gwm, Formulations To Control Subsidence In A Large Scale Transient Problem, Gemma Baro-Montes
Environmental & Water Resources Engineering Masters Projects
The objective of this study is to test different formations with a new optimization program. The area under study is located close to Los Angeles, and it has experienced a large drawdown of the water table, with related subsidence. The analyses utilizes Ground Water Management (GWM), a public domain code distributed by the USGS as a process within MODFLOW 2000. The different algorithms within GWM were tested with a large-scale transient unconfined system. The different analysis allowed the verification of the program. In this application, GWM is used to optimize the resources, and the MODFLOW packages from the LANOPT Model …
Forty-Fifth Annual Allerton Conference On Communication, Control, And Computing, H. Pishro-Nik, A. Ganz, Daiheng Ni
Forty-Fifth Annual Allerton Conference On Communication, Control, And Computing, H. Pishro-Nik, A. Ganz, Daiheng Ni
Daiheng Ni
This paper initiates the study of scaling laws for vehicular ad hoc networks (VANET)s. It provides a general framework to study VANETs. The fundamental capacity limits of these networks are investigated and we show how the road geometry affects this capacity. The VANET capacity is calculated for different road structures. The need for new capacity metrics is dis- cussed. These results are obtained by combining geomet- rical analysis, network flow arguments, and probabilistic study of VANETs.
Treatment Of Domestic Wastewater Using An Anaerobic Membrane Bioreactor: Performance And Characterization, Joseph C. Fermanian
Treatment Of Domestic Wastewater Using An Anaerobic Membrane Bioreactor: Performance And Characterization, Joseph C. Fermanian
Environmental & Water Resources Engineering Masters Projects
Anaerobic wastewater treatment has many advantages over aerobic treatment, however, factors that limit its application are the relatively high concentration of soluble organic matter in the effluent and poor settling characteristics of anaerobic sludge. Membrane filtration provides exceptional solids removal and biomass retention that can improve the biological treatment process as has been seen with aerobic MBR. The application of anaerobic processes and anaerobic membrane bioreactors (AnMBR) has been limited primarily to industrial wastewaters. The use of AnMBR in treating domestic wastewater is of great interest; however, it has not been studied sufficiently to implement on a large scale commercial …
Evaluation And Optimization Of A Pcr Assay And Multiple Regression Model For The Detection Of Rhodococcus Corprophilus, Stephen Clark
Evaluation And Optimization Of A Pcr Assay And Multiple Regression Model For The Detection Of Rhodococcus Corprophilus, Stephen Clark
Environmental & Water Resources Engineering Masters Projects
Rhodococcus coprophilus is an emerging tool in the microbial source tracking "tool-box". The actinomycete is a source specific indicator for grazing animal fecal contamination. Once thought of as less harmful to human health, concern over animal fecal contamination has increased with the greater understanding of zoonoses. Zoonotic organisms that have the ability to cause disease in both humans and animals. Major outbreaks from these pathogens have increased their awareness and created a need for better source water protection. The presence of Rhodococcus coprophilus has been shown to have the ability to indicate grazing animal fecal contamination but it's current detection …
Climate Teleconnections To Yangtze River Seasonal Streamflow At The Three Gorges Dam, China, Casey Brown, K. Xu, H.-H. Kwon, U. Lall, J. Zhang, S. Hayashi, Z. Chen
Climate Teleconnections To Yangtze River Seasonal Streamflow At The Three Gorges Dam, China, Casey Brown, K. Xu, H.-H. Kwon, U. Lall, J. Zhang, S. Hayashi, Z. Chen
Casey Brown
In this study, we identify climatic influences on summer monsoon inflow to the Three Gorges Dam (TGD) in the Yangtze River Basin and use indices of these influences to predict streamflow one season ahead. Summer monsoon streamflow at Yichang hydrological station (YHS) was analyzed for the period 1882–2003. Statistical analysis was used to develop a predictive model for summer streamflow using preceding climate variables. Linear correlation maps were constructed using 3-month ahead climate fields to identify regions that exhibit teleconnections with streamflow at Yichang. The analysis revealed regions in the eastern Indian and western Pacific Oceans that influence YHS streamflow. …
Water Hammer Dissipation In Pneumatic Slug Tests, Don Degroot, David W. Ostendorf, Philip J. Dunaj
Water Hammer Dissipation In Pneumatic Slug Tests, Don Degroot, David W. Ostendorf, Philip J. Dunaj
Don DeGroot
We model and measure the dissipation of water hammer induced by well casing and water elasticity with rapid valve opening at the start of a pneumatic slug test. The higher-frequency water hammer can obscure slower, aquifer-controlled, underdamped oscillations of the rigid water column, so a quantitative description of the elastic motion improves the ability of a slug test to calibrate the aquifer permeability k. Internal friction attenuates the water hammer, subject to a known headspace pressure at the air/water interface and equilibrium pressure at the top of the well screen. An analytical elastic solution is presented and matched to an …
Basin-Scale Methodology For Evaluating Relative Impacts Of Pollution Source Abatement, James T. Mangarillo
Basin-Scale Methodology For Evaluating Relative Impacts Of Pollution Source Abatement, James T. Mangarillo
Environmental & Water Resources Engineering Masters Projects
The Blackstone River watershed covers an area of 475 me in central Massachusetts and northern Rhode Island. The Blackstone flows from its headwaters in the hills above Worcester, MA, through Woonsocket, RI and finally joins the Seekonk River in Pawtucket, RI. The Seekonk then flows into the Providence River on its way into Narragansett Bay. The historical significance of the Blackstone River has been recognized at the federal, state and local levels. Furthermore, the Blackstone is known to playa significant role on the hydrology and ecology of Narragansett Bay. This study is part of a larger study designed to evaluate …
Water Hammer Dissipation In Pneumatic Slug Tests, David Ostendorf, Don J. Degroot, Philip J. Dunaj
Water Hammer Dissipation In Pneumatic Slug Tests, David Ostendorf, Don J. Degroot, Philip J. Dunaj
David Ostendorf
We model and measure the dissipation of water hammer induced by well casing and water elasticity with rapid valve opening at the start of a pneumatic slug test. The higher-frequency water hammer can obscure slower, aquifer-controlled, underdamped oscillations of the rigid water column, so a quantitative description of the elastic motion improves the ability of a slug test to calibrate the aquifer permeability k. Internal friction attenuates the water hammer, subject to a known headspace pressure at the air/water interface and equilibrium pressure at the top of the well screen. An analytical elastic solution is presented and matched to an …
Modeling Traffic Flow Under Emergency Evacuation Situations: Current Practice And Future Directions, Kevin D. Moriarty, Daiheng Ni, John Collura
Modeling Traffic Flow Under Emergency Evacuation Situations: Current Practice And Future Directions, Kevin D. Moriarty, Daiheng Ni, John Collura
Daiheng Ni
The use of evacuation operations in response to emergency conditions has become commonplace. Until recently, planning and response operations have largely been the concern of emergency management personnel. The reoccurrence of catastrophic events, however, has transp ortation officials becoming in creasingly interested in working to improve evacuation efficiency. Emergency managers and transportation officials have employed the use of traffic simulation software to aid in evacuation planning and to evaluate evacuation operations. Effective emergency simulation software needs to be able to capture the major factors influencing evacuation response. This paper aims to discuss the broad role of transportation and the use …