4,291 research outputs found

    Store and Haul: Improving Mobile Ad-Hoc Network Connectivity through Repeated Controlled Flooding

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    This work investigates the benefits and drawbacks of repeating controlled flooding at different intervals in mobile ad hoc networks (MANETs) to overcome episodic connectivity. Specifically, the thesis examines the efficiencies in repeating transmissions by quantifying the packet delivery ratio (PDR) and recording the resulting delays in different types of MANET scenarios. These scenarios mainly focus on partitions within the simulated networks by varying node density and mobility. The nodes store transmitted data and haul it across the MANET in the hope that it will come in range of a node that leads to the destination. A customized version of the Network Simulator 2 (ns-2) is used to create the simulations. A qualitative analysis follows and shows the cost and benefits of increased transmissions at varied time intervals

    Production of Dimethyl Ether (DME) for Transportation Fuel

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    Dimethyl Ether (DME) is a proposed alternative to diesel fuel that is being looked into by car and truck manufacturers worldwide. The current market, based almost completely in China, is primed for growth and a U.S. based DME total plant that is economical and environmentally feasible stands to pave the way for America’s DME market, especially since states such as California have approved DME for use as vehicle fuel (Fuel Smarts). Conventionally, the DME is produced by feeding Methanol into a xed-bed gas-phase reactor over a ɣ-alumina catalyst (Dimian et al). Using this process and normal operating conditions (250-400°C and up to 20 bar) operations can reach 70-80% Methanol conversion. The proposed process utilizes the innovative reactive distillation technology and Amberlyst 35 catalyst to achieve a 99.8% Methanol conversion and produce 35,418 kilograms of DME fuel per hour. The reactive distillation is executed at ~130°C (in the reactive stages) and 700 kPa (condenser pressure), and produces water as a byproduct, which exits as the bottoms stream. In order to create a process that is environmentally sustainable, the small amounts of Methanol and DME in the bottoms stream are removed using biotreatment and the water is then released into a nearby river. The product DME is mixed with mineral oil to meet ISO standards and is then stored in an on-site spherical tank farm. Diesel prices will be undercut by the DME product at 1.716agalloninordertoincentivisecompaniestomaketheswitchtoDMEfuel.TheDMEtotalplant,locatedinBeaumont,Texas,servestoprovidethelocallong−haultruckingindustrywithacleanerburningfuelforaplantlifeof20years.TheDMEtotalplanthasanInternalRateofReturn(IRR)of12.61.716 a gallon in order to incentivise companies to make the switch to DME fuel. The DME total plant, located in Beaumont, Texas, serves to provide the local long-haul trucking industry with a cleaner burning fuel for a plant life of 20 years. The DME total plant has an Internal Rate of Return (IRR) of 12.6%, a Net Present Value (NPV) in 2020 of approximately 12 million, and will turn its rst pro t in 2033. The report addresses nancial, economic, and process concerns to deliver recommendations for the construction that is safest for the environment, the investor, and the plant operator

    Mesh-Mon: a Monitoring and Management System for Wireless Mesh Networks

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    A mesh network is a network of wireless routers that employ multi-hop routing and can be used to provide network access for mobile clients. Mobile mesh networks can be deployed rapidly to provide an alternate communication infrastructure for emergency response operations in areas with limited or damaged infrastructure. In this dissertation, we present Dart-Mesh: a Linux-based layer-3 dual-radio two-tiered mesh network that provides complete 802.11b coverage in the Sudikoff Lab for Computer Science at Dartmouth College. We faced several challenges in building, testing, monitoring and managing this network. These challenges motivated us to design and implement Mesh-Mon, a network monitoring system to aid system administrators in the management of a mobile mesh network. Mesh-Mon is a scalable, distributed and decentralized management system in which mesh nodes cooperate in a proactive manner to help detect, diagnose and resolve network problems automatically. Mesh-Mon is independent of the routing protocol used by the mesh routing layer and can function even if the routing protocol fails. We demonstrate this feature by running Mesh-Mon on two versions of Dart-Mesh, one running on AODV (a reactive mesh routing protocol) and the second running on OLSR (a proactive mesh routing protocol) in separate experiments. Mobility can cause links to break, leading to disconnected partitions. We identify critical nodes in the network, whose failure may cause a partition. We introduce two new metrics based on social-network analysis: the Localized Bridging Centrality (LBC) metric and the Localized Load-aware Bridging Centrality (LLBC) metric, that can identify critical nodes efficiently and in a fully distributed manner. We run a monitoring component on client nodes, called Mesh-Mon-Ami, which also assists Mesh-Mon nodes in the dissemination of management information between physically disconnected partitions, by acting as carriers for management data. We conclude, from our experimental evaluation on our 16-node Dart-Mesh testbed, that our system solves several management challenges in a scalable manner, and is a useful and effective tool for monitoring and managing real-world mesh networks

    Wetlands and Coal Surface Mining: A Management Handbook

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    As the third phase of a three-year project, this report outlines management options for protecting wetlands during the surface mining of coal, particularly for the portion of the Eastern Interior Coal Region that is found in Kentucky, Indiana, and Illinois. It is presented in manual form for use by coal mine operators, regulatory agencies and research institutions. The previous phases of the project produced an atlas of the most heavily-mined areas of the western Kentucky coal field, which classified and identified wetlands in these areas, and discussed some specific impacts of mining on these wetlands. The need to present information that will lead to action by coal operations and regulatory agencies to protect wetland areas, is the incentive for this report. The main issues addressed in this the manual include: basic information for identifying wetlands; wetland values, and methods used for values assessment; how coal surface mining can affect wetlands; a method for addressing wetland protection needs and some prevention and mitigation actions; reclamation alternatives, including wetland restoration and the creation of wetlands as alternative ecosystems on mined areas; and general legal and regulatory information concerning wetland protection and surface mining of coal. Information was gathered through a search of current literature and by contact with state and federal agencies, some coal mining operations, and other concerned organizations. A detailed listing of places to go for more information is included as an appendix

    History of flooding at Colorado State University (1902, 1938, 1951, 1992 and 1997)

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    Final report to Colorado State University.Report number Geotech 1998-100.September 1998.Newspaper reports, photos, rainfall, and damage estimates are presented for the floods of 1902, 1938, 1951 and 1997 which impacted the campus of what is now know as Colorado State University. The September 20 and 21, 1902 flood caused no reported damage to the campus probably because the few buildings built west of the railway track were on high ground. The September 2 and 3, 1938 flood caused flood damage to the Library, Heating Plant, College Avenue Gym/Field House, Physics Building, Museum, steam tunnels, Johnson Hall (Student Union) and flooding of the oval and Tennis Courts. Over 10,000(1938dollars)offlooddamagetothemuseumalonewasreported.TheAugust3,1951floodcausedflooddamagetotheLibrary,HeatingPlant,CollegeAvenueGym/FieldHouse,ElectricalEngineering(formallytheMuseum),Physics,steamtunnels,JohnsonHall(StudentUnion),OldBraidenHallKitchenandfloodingoftheOvalandTennisCourts.The1951campusfloodresultedin10,000 (1938 dollars) of flood damage to the museum alone was reported. The August 3, 1951 flood caused flood damage to the Library, Heating Plant, College Avenue Gym/Field House, Electrical Engineering (formally the Museum), Physics, steam tunnels, Johnson Hall (Student Union), Old Braiden Hall Kitchen and flooding of the Oval and Tennis Courts. The 1951 campus flood resulted in 270,000 (1951 dollars) of flood damage to the campus. The June 24, 1992 flood caused some flood damage to Forestry, Heating Plant and the Administration Annex. The 1992 campus flooding resulted in 75,000(1992dollars)offlooddamageoncampus.TheJuly28,1997floodcausedmajorflooddamagetotheHeatingPlant,CollegeAvenueGym/FieldHouse,Gibbons(formerlytheMuseumandtheElectricalEngineeringBuilding),OccupationalTherapy(formerlythePhysicsBuilding),steamtunnels,JohnsonHall,AdministrationAnnex,MorganLibrary,Lorystudentcenter,Engineering,Education,Eddy,InternationalHouse,UniversityHealthServices,OldDogColonyandfloodingoftheOval,Tenniscourts/parkinglotnorthofEngineering.The1997floodresultedin75,000 (1992 dollars) of flood damage on campus. The July 28, 1997 flood caused major flood damage to the Heating Plant, College Avenue Gym/Field House, Gibbons (formerly the Museum and the Electrical Engineering Building), Occupational Therapy (formerly the Physics Building), steam tunnels, Johnson Hall, Administration Annex, Morgan Library, Lory student center, Engineering, Education, Eddy, International House, University Health Services, Old Dog Colony and flooding of the Oval, Tennis courts/parking lot north of Engineering. The 1997 flood resulted in 100 million (1997 dollars) of flood damage to the campus. Several campus buildings and areas have flooded several times. The old Library (Music), Heating Plant, College Avenue Gym/Field House, Gibbons (old Museum and Electrical Engineering), Occupational Therapy (formerly Physics) and Johnson Hall (old student Union) flooded in the 1938, 1951 and 1997 floods. These six buildings were constructed after the 1902 flood. Morgan Library, Lory Student Center, Engineering, Education, Eddy, International House, University Health Services and the Old Dog Colony were constructed after the 1951 flood

    Design and Performance Analysis of an Aeronautical Routing Protocol with Ground Station Updates

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    Aeronautical routing protocol (AeroRP) is a position-based routing protocol developed for highly dynamic airborne networks. It works in conjunction with the aeronautical network protocol (AeroNP). AeroRP is a multi-modal protocol that operates in different modes depending on the mission requirements. Ground station (GS) update mode is an AeroRP mode in which the GS sends geolocation or topology updates to improve routing accuracy. The main contribution of this thesis is to develop and implement the GS updates in AeroRP and analyse its performance in the various modes and compare them against canonical MANET routing protocols such as DSDV, OLSR, AODV, and DSR. The simulation analysis shows that AeroRP outperforms the traditional MANET protocols in various scenarios

    I Am Not a Tractor! How Florida Farmworkers Took on the Fast Food Giants and Won

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    [Excerpt from jacket] I Am Not a Tractor! celebrates the courage, vision, and creativity of the farmworkers and community leaders who have transformed one of the worst agricultural situations in the United States into one of the best. Susan L. Marquis highlights past abuses workers in Florida\u27s tomato fields: toxic pesticide exposure, beatings, sexual assault, rampant wage theft, and even, astonishingly, modern-day slavery. Marquis unveils how, even without new legislation, regulation, or government participation, these farmworkers have dramatically improved their work conditions. Marquis credits this success to the immigrants from Mexico, Haiti, and Guatemala who formed the Coalition of Immokalee Workers, a neuroscience major who takes great pride in the watermelon crew he runs, a leading farmer/grower who was once homeless, and a retired New York State judge who volunteered to stuff envelopes and ended up building a groundbreaking institution. Through the Fair Food Program that they have developed, fought for, and implemented, these people have changed the lives of more than thirty thousand field workers. I Am Not a Tractor! offers a range of solutions to a problem that is rooted in our nation\u27s slave history and that is worsened by ongoing conflict over immigration

    Marine Resource Bulletin Vol. 41, No. 1

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    In This Issue Forecasting the Rising Tide 2 Coastal Virginia is one of the most vulnerable areas in the country to sea-level rise. With help from Sea Grant, VIMS researchers are helping Virginia communities predict and prepare for the increasingly frequent floods that climate change and rising seas will bring. Trabajadores 6 The new workforce in seafood processing is a growing population of seasonal migrant workers—almost all of them hispanic. Sea Grant is helping these workers and the foods they process stay safe by providing specialized on-the-job training in Spanish. Sowing the Seeds 10 A technique called spat-on-shell is promising to take Virginia’s burgeoning oyster aquaculture industry to the next level. A unique combination of public and private partners have come together to make this promise a reality. News from the Point 14 The latest news from Virginia Sea Grant, including an interview with Virginia’s Knauss Fellows about their year in Washington D.C., Blue Crab Bowl, Hampton boat tax study, and recent grants awarded by Sea Grant and the Virginia Fisheries Resource Grant Program.https://scholarworks.wm.edu/vimsmrb/1090/thumbnail.jp
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