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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

How Childcare Type and Disaster Recovery Funding Type Impact Childcare Recovery

Beal, Heather L 01 January 2019 (has links)
Childcare is critical community infrastructure, yet it is typically not eligible for recovery assistance postdisaster. The effect of disaster on children has been extensively studied and research indicates that the return to normalcy (e.g., through restoration of childcare programs) helps aid recovery. Despite this, little research has been conducted on how childcare programs recover. The purpose of this research was to investigate how the recovery times for childcare programs affected by Superstorm Sandy varied based on childcare typology and the recovery funding resources used. A quasi-experimental research design was selected and data from 76 surveys was evaluated using one-way and factorial analysis of variance. The research questions were designed to evaluate the impact of recovery funding types used, childcare type, number of recovery funding resources used, and the interaction of childcare type and recovery funding types used on recovery time. Resource dependence theory was chosen as the theoretical framework because of its precept that only effective organizations survive through application of behaviors such as diversification of resources. The results revealed that there was a statistically significant relationship between the number of recovery resources used and recovery time (p = .04). Social change starts with information. This study supported social change by providing a baseline for childcare recovery research and emphasizing the importance of childcare to both community recovery and the recovery of children in disaster recovery policy.
32

Water table distributions in a sandy soil with subirrigation

Gallichand, Jacques. January 1983 (has links)
No description available.
33

Designing subsurface drainage systems to avoid excessive drainage of sands.

Rashid-Noah, Augustine Bundu. January 1981 (has links)
No description available.
34

Commute Travel Changes and their Duration in Hurricane Sandy's Aftermath

Kontou, Eleftheria 31 January 2014 (has links)
Hurricane Sandy struck the New York City-New Jersey region on October 29, 2012, with severe consequences to the transportation network, including both the road network and the transit system. This study used survey data from nearly 400 commuters in the New York City Metropolitan Area to determine the transportation disruptions and socio-demographic characteristics associated with travel changes and their duration for the home-to-work commute after Hurricane Sandy. Multi-variable binary logit modeling was used to examine mode shifting, cancelling the trip to work, route changing, and modifying departure time. Transit commuters were more likely to change modes, cancel the trip, and depart earlier. Women were less likely to change modes or depart later. Carpool restrictions encouraged mode changing and earlier departures. Delays/crowding increased the probability of route changes, canceled trips, and earlier departures. Durations of commute travel changes were modeled with accelerated failure time approaches (Weibull distribution). New Jersey Transit disruptions prolonged the time to return to the normal working schedule, telecommuting time, and the time of commuting patterns alterations. Gasoline purchase restrictions extended commuting delays and the duration of alteration of normal commute patterns but decreased the duration of the change of working schedule and location. The mode used under normal commute conditions did not have an impact on the duration of the changes, even though it has a significant impact on the selected changes. The results underline the need for policy makers to account for mode-specific populations and lower income commuters during post-disaster recovery periods. / Master of Science
35

Agent-based Modeling for Recovery Planning after Hurricane Sandy

Hajhashemi, Elham 13 September 2018 (has links)
Hurricane Sandy hit New York City on October 29, 2012 and greatly disrupted transportation systems, power systems, work, and schools. This research used survey data from 397 respondents in the NYC Metropolitan Area to develop an agent-based model for capturing commuter behavior and adaptation after the disruption. Six different recovery scenarios were tested to find which systems are more critical to recover first to promote a faster return to productivity. Important factors in the restoration timelines depends on the normal commuting pattern of people in that area. In the NYC Metropolitan Area, transit is one of the common modes of transportation; therefore, it was found that the subway/rail system recovery is the top factor in returning to productivity. When the subway/rail system recovers earlier (with the associated power), more people are able to travel to work and be productive. The second important factor is school and daycare closure (with the associated power and water systems). Parents cannot travel unless they can find a caregiver for their children, even if the transportation system is functional. Therefore, policy makers should consider daycare and school condition as one of the important factors in recovery planning. The next most effective scenario is power restoration. Telework is a good substitute for the physical movement of people to work. By teleworking, people are productive while they skip using the disrupted transportation system. To telework, people need power and communication systems. Therefore, accelerating power restoration and encouraging companies to let their employees' telework can promote a faster return to productivity. Finally, the restoration of major crossings like bridges and tunnels is effective in the recovery process. / Master of Science / Natural and man-made disasters, cause massive destruction of property annually and disrupt the normal economic productivity of an area. Although the occurrence of these disasters cannot be controlled, society can minimize the effects with post-disaster recovery strategies. Hurricane Sandy hit New York City on October 29, 2012 and greatly disrupted transportation systems, power systems, work, and schools. In this research, commuter behavior and adaptation after the hurricane were captured by using a survey data that asked questions from people living in NYC metropolitan area about their commuting behavior before and after Hurricane Sandy. An agent-based model was developed and six different recovery strategies were tested in order to find effective factors in returning people to normal productive life faster. In the NYC Metropolitan Area, transit is one of the common modes of transportation; therefore, it was found that the subway/rail system recovery is the top factor in returning to productivity. The next important factor is school and daycare closure. Parents are responsible for their children, therefore; they may not travel to work when school and daycares are closed. The third important factor is power restoration. To telework, people need power and communication systems. By teleworking, people are productive while they skip using the disrupted transportation system. The final important factor is the restoration of major crossings like bridges and tunnels.
36

Morphological Change of a Developed Barrier Island due to Hurricane Forcing

Smallegan, Stephanie Marie 25 April 2016 (has links)
An estimated 10% of the world's population lives in low-lying coastal regions, which are vulnerable to storm surge and waves capable of causing loss of lives and billions of dollars in damage to coastal infrastructure. Among the most vulnerable coastlines are barrier islands, which often act as the first line of defense against storms for the mainland coast. In this dissertation, the physical damage to a developed barrier island (Bay Head, NJ, USA) caused by erosion during Hurricane Sandy (2012) is evaluated using the numerical model, XBeach. Three main objectives of this work are to evaluate the wave-force reducing capabilities of a buried seawall, the effects of bay surge on morphological change and the effectiveness of adaptation strategies to rising sea levels. According to simulation results, a buried seawall located beneath the nourished dunes in Bay Head reduced wave attack by a factor of 1.7 compared to locations without a seawall. The structure also prevented major erosion by blocking bay surge from inundating dunes from the backside, as observed in locations not fronted with a seawall. Altering the timing and magnitude of bay storm surge, the buried seawall continued to protect the island from catastrophic erosion under all conditions except for a substantial increase in bay surge. However, in the absence of a seawall, the morpho- logical response was highly dependent on bay surge levels with respect to ocean side surge. Compared to the damage sustained by the island during Hurricane Sandy, greater erosion was observed on the island for an increase in bay surge magnitude or when peak bay surge occurred after peak ocean surge. Considering sea level rise, which affects bay and ocean surge levels, adaptation strategies were evaluated on the protection afforded to the dune system and backbarrier. Of the sea level rise scenarios and adaptation strategies considered, raising the dune and beach protected the island under moderate rises in sea level, but exacerbated backbarrier erosion for the most extreme scenario. Although an extreme strategy, raising the island is the only option considered that protected the island from catastrophic erosion under low, moderate and extreme sea level rise. / Ph. D.
37

An ecophysiological approach to determine problems associated with mine-site rehabilitation : a case study in the Great Sandy Desert, north-western Australia

Grigg, Alasdair M January 2009 (has links)
[Truncated abstract] Establishment of vegetation and ecosystem functioning is central to the mitigation of environmental impacts associated with mining operations. This study investigated the ecophysiological functioning of mature plants in natural vegetation and applied this knowledge to diagnose problems affecting plant health and causes of poor plant cover at a mine-rehabilitation site. Ecophysiological parameters, including plant water relations and mineral nutrition, were studied in conjunction with soil physical, hydraulic and chemical properties. The natural ecosystem at the study location in the Great Sandy Desert is characterised by sand dunes and interdunes with distinct plant communities on each. One of the most notable features of the vegetation is the presence of large Corymbia chippendalei trees high on the dunes and relatively small scattered shrubs in the interdunes. Triodia grasses (spinifex), dominate the vegetation in both habitats but different species occur in each; T. schinzii is restricted entirely to the dunes, and T. basedowii occurs only in the interdunes. It was hypothesised that the deep sandy dunes afford greater water availability but lower nutrient supply to plants in this habitat compared with those occurring in the lower landscape position of the interdunes. Water-relations parameters (leaf water potentials, stomatal conductance, d13C) revealed that dune plants, particularly woody species, displayed higher water status and water use than closely related and often congeneric plants in the interdunes. Nutrient concentrations in soils were significantly higher in the interdunes, but concentrations in foliage were similar for related species between habitats. It is concluded that the dunes provide a greater store of accessible water than the soil profile in the interdunes. ... Following an experimental wetting pulse equivalent to a summer cyclone event, A. ancistrocarpa plants displayed significant increases in stomatal conductance, leaf water potential and sap velocity in lateral roots within three days of irrigation at the natural site and two days at the rehabilitation site. Secondary sinker roots originating from distal sections of lateral roots were evidently supplying water to maintain hydraulic function in laterals, thus enabling a fast pulse response. This was accentuated at the rehabilitation site where roots were confined closer to the surface. These results indicate that plants at the rehabilitation site are more dependent on small pulses of water and have less access to deep reserves than plants at the natural site. It is concluded that high runoff losses and insufficient soil depth are major factors contributing to plant water stress, and combined with the direct impacts of erosion, are largely responsible for plant death and ultimately poor plant cover. These issues can be alleviated if cover soil depth is increased to more than 0.5 m and slope angles are reduced to <12o. This study demonstrates the value of an ecophysiological approach for diagnosing problems affecting plant establishment at mine-rehabilitation sites. Furthermore, it has provided recommendations that will improve the rehabilitation strategy and lead to the development of a well vegetated, resilient ecosystem on a stable and non-polluting land form.
38

Reservoir Evolution Following the Removal of Marmot Dam on the Sandy River, Oregon

Keith, Mackenzie Karli 01 January 2012 (has links)
The October 2007 removal of Marmot Dam, a 14.3-m-tall dam on the Sandy River in northwestern Oregon storing approximately 730,000 m3 of impounded sediment, provided an opportunity to study short- and long-term geomorphic effects of dam removal. Monitoring reservoir morphology during the two years following dam decommissioning yields a timeline of reservoir channel change. Comparison of a pre-dam survey in 1911 with post-removal surveys provides a basis from which to gage the Reservoir Reach evolution in the context of pre-dam conditions. Analyses of time-lapse photography, topographic surveys, and repeat LiDAR data sets provide detailed spatial and temporal documentation of a release of sediment from the reservoir following dam removal. The majority of morphologic changes to the reservoir largely took place during the first few days and weeks following removal. Channel incision and widening, along with gradient changes through the Reservoir Reach, exhibit diminishing changes with time. Channel incision rates of up to 13 m/hr and widening rates of up to 26 m/hr occurred within the first 24 hours following breaching of the coffer dam. Although channel position through the Reservoir Reach has remained relatively stable due to valley confinement, its width increased substantially. The channel reached an average width of 45 m within two weeks of breaching, but then erosion rates slowed and the channel width reached about 70 to 80 m after one and two years, respectively. Diminishing volumes of evacuated sediment were measured over time through quantitative analysis of survey datasets. About 15 percent of the initial impounded sediment was eroded from the Reservoir Reach within 60 hours of breaching; after one and two years, 50 and 58 percent was eroded, respectively. Grain-size analysis of terraces cut into reservoir fill following dam removal show that bed material coarsened over time at fixed elevations and vertically downward as the channel incised. Overall, these findings indicate valley morphology and local in-channel bedrock topography controlled the spatial distribution of sediment within the reservoir reach while variability in river discharge determined the timing of episodic sediment release. Changes within the Reservoir Reach shortly after dam removal and subsequent evolution over the two years following removal are likely attributable to 1) the timing and intensity of flow events, 2) the longitudinal and stratigraphic spatial variations in deposit grain-size distributions initially and over time, and 3) the pre-dam topography and existing valley morphology.
39

Creep in sands: a study of time dependent deformation of reclamation sand fill under constant effectivestress

Ching, Peter., 秦培德. January 2001 (has links)
published_or_final_version / Applied Geosciences / Master / Master of Science
40

Determinants of HIV Screening Among Adults in New Jersey After Hurricane Sandy

Geyer, Nathaniel R. 01 January 2017 (has links)
HIV screening is recommended to destigmatize the condition, prevent partner transmission, and postpone AIDS progression. However, determinants associated with implementation of opt-out HIV screening are not well understood. The purpose of the study was to examine determinants that predicted odds of HIV screening for persons impacted by Hurricane Sandy, and how these factors differed according to demographic characteristics, geographical attributes, health-related quality of life score, access-to-care, and health insurance status. The social ecologic model provided the framework for this multilevel cross-sectional study that included New Jersey data from the Behavior Risk Factor Surveillance System. Bivariate chi-square, simple logistic regression, and adjusted multivariate and weighted logistic regression analyses were performed to estimate HIV screening odds. Findings indicated a significant odds ratio with access to care post- Hurricane Sandy and HIV screening (odds ratio = 1.74, 95% CI = 1.38-2.21). The positive social change implications may include assisting people to develop realistic plans for HIV screening, improving understanding of HIV screening determinants, and raising awareness of the risk factors related with access to medical care post-Hurricane Sandy.

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