Thesis (Ph. D.)--University of California, San Diego, 1997. / Vita. Includes bibliographical references (leaves 373-401).

Thesis (M.A.)--West Virginia University, 2000. / Title from document title page. Document formatted into pages; contains xi, 132 p. : ill. (some col.), maps (some col.). Includes abstract. Includes bibliographical references (p. 125-126).

Thesis (Ed. D.)--West Virginia University, 2008. / Title from document title page. Document formatted into pages; contains ix, 134 p. : ill. (some col.), map. Includes abstract. Includes bibliographical references (p. 94-97).

Thesis (Ed. D.)--West Virginia University, 2008. / Includes abstract. Includes bibliographical references (p. 94-97).

Användandet av maskinstyrning har länge varit vanligt vid större vägbyggen och järnvägsbyggen. Det har likväl blivit allt mer vanligare vid anläggning av vatten- och avloppsledningar [VA-ledningar], dock finns det inte många undersökningar om hur användandet av maskinstyrning påverkar den typen av arbete. Rapporten ska undersöka hur ett VA-projekt blir påverkat av att använda grävmaskiner som är utrustade med maskinstyrning. Undersökningen ska genomföras i två moment, enkätstudie samt en ekonomisk jämförelse, och ska täcka tre olika teman, ekonomi, arbetsmiljö och miljö. Det gjordes olika  enkäter som personer med olika befattningar fick besvara. De som fick enkäter var personer som blev påverkade på olika sätt av att maskinstyrning användes i projekt. Dessa enkäter behandlade alla tre ovan nämnda teman. För att göra en djupare undersökning om hur användandet av maskinstyrning påverkar ekonomin, hämtades siffror på kostnader och framdrift/produktivitet från ett VA-projekt i Toverud, Hammarö. Där användes grävmaskiner som var utrustade med maskinstyrning. Dessa siffror jämfördes mot ett referensprojekt som också utfördes i Hammarö men år 2009 då maskinstyrning inte användes. Resultatet visar att användandet av maskinstyrning ökar produktiviteten samtidigt som det minskar arbetsbelastningen och faror för arbetarna. Eftersom att samma typ av arbete utförs på kortare tid minskar den totala bränsleförbrukningen för projektet. Beräkningarna visade att ett arbete där 1100 meter VA-ledning skulle anläggas gjordes en besparing på 3178 liter diesel samt att utförandetiden gick cirka 15 dagar snabbare om grävmaskinerna var utrustade med maskinstyrning. En begränsning med maskinstyrning är att det uppkommer mycket arbete för mätteknikern om flertalet revideringar av ritningarna krävs. Det är väldigt viktigt att mätteknikern gör ett bra arbete med linjeprofilen, annars försvinner de positiva effekterna med att använda maskinstyrning i arbetet. Höga byggnader och skog kan vara ett problem för mottagningen.  Slutsatsen är att produktiviteten ökar samt att kvalitet på arbetsmiljön blir bättre vid användning av maskinstyrning. / The use of machine control has long been common in major road construction and railway construction. However, machine control has become more and more common when digging trenches for pipe laying, but there are not many studies on how the use of machine control affects a work as trench digging for pipe laying.   The report will investigate how a sewer, water and drain pipe project is influenced by using excavators that are equipped with machine control. The investigation will be conducted in two parts and will cover three different themes, economics, work environment and environment.   Different questionnaires were customized for people with different positions. The persons surveyed were workers affected by the use of machine control in projects. These surveys addressed all three of the above topics.   In order to make a deeper study of how the use of machine control affects the economy, figures on costs and progress / productivity were collected from a trench digging and pipe laying project in Toverud, Hammarö. There they used excavators that were equipped with machine control. These figures were compared to a reference project that was also carried out in Hammarö, but in 2009 when machine control was not used.   The result shows that the use of machine control increases productivity while reducing workload and dangers for workers. Because the same type of work is carried out in less time, the total fuel consumption for the project decreases. The calculations showed that a work involving 1100 meters of trench digging and pipe laying. There would be savings up to around 3178 liters of diesel, and that the execution time would be about 15 days faster if the excavators were equipped with machine control. A limitation of machine control is that there is a lot of work for the surveyor if many revisions of the drawings are required. It is very important that the surveyor performs well with the line profile, otherwise the positive effects of using machine control at work will disappear. High buildings and forests can be a problem for the reception. The conclusion is that productivity increases and quality in the work environment is improved when using machine control.

Contaminant fate and transport are two of the most important issues project officers have to deal with when developing a sound remediation strategy for a subsurface contamination site. To accurately assess these issues, knowledge of possible pathways, travel times and groundwater receptors are required. A groundwater flow model of a site facilitates the assessment process by determining flow paths, discharge areas and travel time from a contaminant source to a potential receptor. The resulting model can also be used to show potential impacts on drinking water sources and surface habitats. This project is Phase II of the proposed three phase project, Groundwater Flow Modeling of the Aquifer System at Ft. Belvoir (Widdowson, 1998). Phase I consisted of developing a conceptual model of the aquifer system, recommending a modeling strategy and developing a data collection strategy. The objectives of this phase are to design and construct a computer simulation of the groundwater flow system in the aquifers below Ft. Belvoir and to develop a strategy for improved data collection using the results of the model. Steps in this phase included creation of the numerical model, calibration to known water surface elevations, and a sensitivity analysis of the boundary conditions. The numerical model was created in the Department of Defense Groundwater Modeling System environment using MODFLOW. The model was calibrated to pre-1970 wells for the deep aquifer and recent site characterization wells for the upper aquifer. The head distribution was influenced the greatest by topography and the major creeks. Accuracy of the well surface elevations played a major role in the calibration process, as well as tidal influences. A sensitivity analysis showed that adjusting the recharge and the seepage face parameters affected the model results (head and groundwater flow rates) the greatest. While adjusting the constant head and general head boundaries affected the model results the least. / Master of Science

Entocytherid ostracods were collected on crayfishes inhabiting the James and York River basins of Virginia. Of the seventeen species encountered, only one (Donnaldsoncythere ardis) seems to be endemic. Ankylocythere ancyla, Dactylocythere banana, Dt. falcata, Dt. suteri, Donnaldsoncythere ardis, Dn. hiwasseensis, Dn. truncata, Entocythere sp. A, E. internotalus and Phymocythere phyma occur on the crayfishes Cambarus acuminatus, C. b. bartonii, C. longulus and Orconectes juvenilis in the streams of the Valley and Ridge Province. In the Coastal Plain where sluggish streams are encountered, Ankylocythere telmoecea and Ank. tiphophila are associated with Procambarus a. acutus. Cambarus acuminatus is also found in the Coastal Plain in moderately flowing streams and it is infested with Dactylocythere suteri and Donnaldsoncythere hiwasseensis. The primary burrowing crayfish of the Alleghany Mountains (Cambarus dubius) is host to Ascetocythere asceta and Dactylocythere chalaza whereas its ecological similar Cambarus d. diogenes of the Piedmont and Coastal Plain is the only host known with certainty for Dactylocythere jeanae, Okriocythere cheia and Ornithocythere waltonae. Ankylocythere tiphophila is associated with Fallicambarus uhleri, an inhabitant of swampy areas and marshes and may ocassionally construct simple burrows in the Coastal Plain. / Master of Science

Master of Science

Thesis (Ed. D.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains x, 285 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 256-272).

Thesis (M.A.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains iii, 72 p. Includes abstract. Includes bibliographical references (p. 58-67).