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Högläggning eller harvning : En jämförande studie av planteringspunkter och markpåverkan vid olika terrängförhållanden. / Mounding or disc trenching? : A comparing study of planting spots and terrain impact in different types of terrain.Karlsson, Josef January 2016 (has links)
A comparing study of planting spots and terrain impact in different types of terrain.
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Flowable Controlled Strength Fill (FCSF) for duct cable network trenchesAl-Gassas, Riyadh January 2001 (has links)
No description available.
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Study of the Fatigue Life of Steel Catenary Risers in Interaction with the SeabedNakhaee, Ali 2010 December 1900 (has links)
The fatigue life of a Steel Catenary Riser (SCR) near its touch-down zone is
substantially affected by its interaction with the seabed. Hence, accurate estimate of its
fatigue life requires the understanding and realistic modeling of the interaction between
them.
The interaction between SCR and the seabed depends on many factors, such as soil
properties, riser characteristics, and the development of trenching at the seafloor.
Existing approaches for modeling the seabed in interaction with a SCR approximate the
seabed soil by a linear or nonlinear spring and a dashpot which respectively represent the
stiffness and damping of the soil. However, they do not take into account certain
phenomena resulting from plastic deformation or degradation of the seabed soil, such as
trenching. In this study, a more realistic approach is developed for simulating the
interaction between a SCR and the seabed soil. In addition to the use of a realistic P-y
curve (where P stands for the supporting or resistance force of the seafloor and y for the
vertical penetration of the riser into the soil) to simulate the soil deformation during its interaction with a riser, it considers the development of a trench caused by continuous
poundings of a riser on the seabed and then its feedback effect on the variation of the
bending moment along the riser.
In this study, it has been found that trenching underneath a SCR may decrease the
maximum variation of bending moment near its touch-down zone. Since the variation of
the moment dictates the fatigue damage to the SCR, the results based on this approach
indicate that the trenching development at the seabed may increase the fatigue life of a
SCR and therefore, it may have important application to the design of a SCR.
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Phytoremediation case study, Manhattan KSStiffarm, Ashley Marie January 1900 (has links)
Master of Science / Department of Horticulture, Forestry, and Recreation
Resources / Charles J. Barden / Contaminated water poses a major environmental and human health problem, which may be resolved by using the emerging phytoremediation technology. This plant-based cost-effective approach to remediation takes advantage of the ability of plants to concentrate elements and compounds from the environment, to absorb and transpire large amounts of water, and to metabolize various molecules in their tissues. The city of Manhattan’s Biosolids Farm located near Manhattan, Kansas is using the emerging technology of phytoremediation. The Biosolids Farm remediation began in the mid 1990’s; with a large planting of alfalfa with the goal of absorbing excess nitrates from soil and ground water. In 2004, hundreds of trees were planted, to serve as a protective buffer between the biosolids disposal area and the Kansas River. In 2006, a trench study was installed to improve tree establishment on a sandy outwash area close to the Kansas River using Siberian elm seedlings and rooted cottonwood cuttings from Nebraska and true cottonwood seedlings from Missouri. Treatments included trenching, dairy cattle composted manure, and tree shelters. This planting was done to serve as a vegetative barrier and to aid in reducing nitrate movement into the Kansas River. There were interaction between the tree sources and the trenching, compost and shelter treatments. The treatments showed significant interactions with tree sources with the addition of compost and shelters with a p value of 0.0438, and trenching and compost p-value 0.0021. Tree survival was significantly improved with the use of tree shelters.
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How does drainage affect hydrology and hydrochemistry in boreal peatlands?Enetjärn, Albin January 2018 (has links)
Boreal peatlands are substantial terrestrial carbon storages. They are also important for the function of several large-scale cycles and systems that humanity benefits from. Drainage affects peatlands by establishing a new, lower equilibrium for the groundwater table. As a consequence of a lowered groundwater table and physical disturbance from the ditch, a chain of events is triggered, causing a number of changes in the hydrology and hydrochemistry of peatlands. The review aimed at gathering the most relevant literature on how boreal peatlands are affected by drainage. This was carried out by searching for scientific articles on online databases and libraries. Besides reviewing hydrology and hydrochemistry, a compilation of boreal peatland characteristics and a background on the history of Swedish peatland drainage are handled in the report. The results show that concentrations and loads for a long range of water quality parameters are affected by drainage. The effects vary a lot depending on different peatland characteristics. Both runoff and chemical changes depends largely on whether ditches reach mineral soil beneath the peat. The most obvious and adverse effect on chemistry is a large increase in suspended solid concentration and export. Other changes include increases of mineralized nitrogen, decreased organic carbon transport, increased annual runoff and increased levels for a number of elements, such as Mg, Ca, K and Mn.
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Oribatid mite community structure and trophic ecology along a forest land-use gradient: effect of dead wood, time and root-trenchingBluhm, Christian 29 April 2016 (has links)
No description available.
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Desidrata??o e perdas de nutrientes no processo de fena??o de leguminosas forrageiras tropicais / Dehydration curve and nutrient losses haying process legumes tropical foragersArcanjo, Angelo Herbet Moreira 19 April 2016 (has links)
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Previous issue date: 2016 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Objetivou com esse trabalho avaliar a curva de desidrata??o e a perda de nutrientes de tr?s leguminosas forrageiras tropicais durante a fena??o. O estudo foi conduzido na Fazenda Experimental do Moura ? UFVJM, localizada no munic?pio de Curvelo MG. Foi adotado um delineamento inteiramente casualizado, em esquema fatorial 3 x 3, sendo tr?s esp?cies de leguminosas forrageiras tropicais (Estilosantes Campo Grande, Puer?ria e Macrotiloma) e tr?s fases de desidrata??o (1? fase: 0 a 8h; 2? fase: 12 a 20h; e 3? fase: 24 a 32 horas de secagem), com quatro repeti??es. As diferen?as entre as m?dias foram analisadas pelo teste Tukey (p<0,05). As forrageiras foram cortadas manualmente, picadas e espalhadas sobre lonas pl?sticas para otimiza??o da desidrata??o. A desidrata??o das forrageiras teve in?cio ?s 9:00 do dia 21 de fevereiro. O procedimento de amostragem foi realizado a cada 2 horas, no primeiro dia, e a cada 4 horas, no segundo e terceiro dias. Nos tempos previamente estabelecidos, as amostras foram identificadas, pesadas e submetidas a estufa de circula??o for?ada a temperatura de 55oC por 72h para a pr? secagem. Para a determina??o da curva de desidrata??o e quantifica??o da perda de nutrientes durante a desidrata??o foram realizadas as seguintes an?lises bromatol?gicas: mat?ria seca (MS), mat?ria mineral (MM), fibra em detergente neutro corrigido para cinza e prote?na (FDNcp), fibra em detergente ?cido (FDA), extrato et?reo (EE), prote?na bruta (PB), nitrog?nio n?o proteico (NNP) e carboidratos sol?vel (CHOS). Foram tamb?m estimados os teores de carboidratos totais (CHT), carboidrato n?o fibroso (CNF) e nutrientes digest?veis totais (NDT). Durante a curva de desidrata??o foi observada maior efici?ncia de secagem para as esp?cies Estilosantes e Puer?ria. Ao fim dos tempos de avalia??o, o Macrotiloma apresentou teor de umidade superior ao recomendado para armazenamento. As tr?s leguminosas apresentaram aumento crescente do teor de MS em fun??o do tempo de desidrata??o. N?o foram observados efeitos para os teores de MM, FDNcp, FDA, CNF, CHT e NDT no decorrer da curva de desidrata??o. O Estilosantes e o Macrotiloma apresentaram perda nos teores de EE na primeira fase, o Macrotiloma apresentou os maiores teores de EE entre as esp?cies estudadas. A Puer?ria apresentou acr?scimo no teor de PB da primeira fase para a segunda e foi leguminosa que apresentou maior teor desse nutriente entre as leguminosas estudadas. As tr?s leguminosas apresentaram redu??o nos teores de NNP na primeira para a segunda fase da curva de desidrata??o. O Macrotiloma foi a ?nica leguminosa que apresentou redu??o dos teores de CHOS durante a curva de desidrata??o e a leguminosa que apresentou os maiores teores deste constituinte. O Estilosantes foi a leguminosa que apresentou a desidrata??o mais eficiente durante o processo de fena??o, chegando mais rapidamente ao teor de umidade recomendado para o armazenamento. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Zootecnia, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2016. / The objective with this study was to evaluate the dehydration curve and nutrient loss of three tropical forage legumes during haymaking. The study was conducted at the Experimental Farm of Moura- UFVJM, located in Curvelo MG. A completely randomized design in a factorial 3 x 3, three species of tropical forage legumes was adopted (Stilosanthes Campo Grande, Kudzu and Macrotyloma) and three stages of dehydration (Phase 1: 0 to 8 am; 2nd phase: 12 to 20h; and phase 3: 24 to 32 hours of drying), with four replications. Differences between means were analyzed by the Tukey test (p <0.05). The foragers were manually cut, chopped and spread on plastic sheeting to optimize the dehydration. The dehydration of fodder began at 9:00 am on 21 February. The sampling procedure was performed every 2 hours on the first day and every 4 hours in the second and third days. In the time previously established, samples were identified, weighed and subjected to forced circulation oven temperature 55?C for 72h for pre-drying. For the determination of the dehydration curve and quantifying the loss of nutrients during dehydration were performed the following chemical analysis: dry matter (DM), mineral matter (MM), neutral detergent fiber corrected for ash and protein (NDFap), acid detergent fiber (ADF), ether extract (EE), crude protein (CP), non-protein nitrogen (NPN) and soluble carbohydrates (SCHO). It was also estimated the total carbohydrates (TCH), non-fibrous carbohydrate (NFC) and total digestible nutrients (TDN). During dehydration curve was greater drying efficiency for Stilosanthes and Kudzu species. At the end of the assessment times, Macrotyloma presents moisture content higher than recommended for storage. The three legumes have increasing the dry matter content due to the dehydration time. No effects for MM, NDF, FDA, CNF, CHT and NDT during the dehydration curve. The Stilosanthes and Macrotyloma showed loss in EE levels in the first phase, the Macrotyloma showed the highest EE levels among the studied species. The Kudzu has increased in the first phase CP content for the second and was legume with the highest content of this nutrient among the studied legumes. The three legumes have reduced the NPN content in the first to the second phase of dehydration curve. The Macrotyloma was the only legume that decreased the SCHO contents during dehydration curve and legumes that presented the highest levels of this constituent. The Stilosanthes was legume that presented the most efficient dehydration during the haying process, coming faster to the moisture content recommended for storage.
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Hydrologic Effects of Contour Trenching on Some Aspects of Streamflow from a Pair of Watersheds in UtahDoty, Robert Dean 01 May 1970 (has links)
Streamflow from two drainages of the Davis County Experimental Watershed, Utah, was evaluated with respect to changes in distribution and volume following trenching of one of the drainages in 1964. Fifteen percent of the Halfway Creek drainage was trenched according to established U.S. Forest Service methods. Twelve years of records before trenching and four years of records after trenching were analyzed.
Analysis of the annual streamflow, the low streamflow period, and the spring streamflow period indicated no significant change in either volume or distribution of streamflow as a result of trenching. This conclusion was further substantiated by supplemental data of precipitation, soil moisture, snowpack water equivalent, and vegetation.
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Gestion des risques relatifs à la stabilité des arbres paysagers : biomécanique et architecture du système racinaireAbd Ghani, Murad 14 October 2008 (has links)
L’impact de la perte racinaire sur l’ancrage d’Eugenia grandis Wight et de Pinus pinaster Ait ainsi que la capacité de trois différentes espèces d’arbres (Fagus sylvatica L, Abies alba Mill et Picea abies L) à résister au déracinement ou à la rupture sous l’effet d’un éboulement en pente raide ont été étudiés au moyen de tests de treuillage et le creusement de tranchées (tree winching and trenching tests) et les résultats ont été corrélés avec la structure du système racinaire. Aucune différence n’a été observée entre TMcrit et la distance de creusement de tranchée sur E. grandis. Les résultats obtenus ont révélé qu’en termes de rigidité rotationnelle de l’ancrage des arbres (TARS) et de TMcrit, la stabilité mécanique n’a pas été significativement affectée par le creusement de tranchées en sol argilo-sableux en raison de la profondeur d’enracinement des racines pivotantes (« sinker roots ») qui se sont formées près du tronc et en raison de la taille de la plaque racinaire qui augmente la rigidité et constitue donc une composante importante de l’ancrage d’E. grandis. Toutefois, pour P. pinaster, la stabilité mécanique a été significativement affectée par le creusement de tranchée, probablement en raison de la coupe des racines latérales qui a considérablement altéré la taille de la plaque racinaire et, en conséquence, la somme des surfaces en section (CSA= cross-sectional area) de la plupart des racines latérales et d’un certain nombre de racines traçantes, ce qui constitue une des composantes essentielles de l’ancrage d’arbres P. pinaster adultes plantés en podzol sableux. Pour les espèces forestières de protection plantées en pente raide, les résultats obtenus ont révélé que les espèces d’arbre présentant un système racinaire profondément enfoui et fortement ramifié avec une grande proportion de racines obliques (par exemple, le hêtre et le sapin pectiné) seront mieux ancrées et auront une meilleure fonction anti-éboulement que epicéa commun qui possède un système racinaire superficiel et peu profond. Les connaissances apportées par cette étude peuvent être utilisées pour la sélection et la production d’arbres qui résistent aux risques naturels ainsi qu’aux risques provoqués par l’Homme. / The impact of root loss on tree anchorage on Eugenia grandis Wight and Pinus pinaster Ait and the ability of three different trees species (Fagus sylvatica L, Abies alba Mill and Picea abies L) to resist uprooting or breakage due to rockfall on steep slopes were investigated using tree winching and trenching tests and results correlated to root system architecture. No differences were found between TMcrit and trenching distance in E. grandis trees. The results showed that in terms of Tree Anchorage Rotational Stiffness (TARS) and TMcrit, mechanical stability was not significantly affected by trenching on sandy clay soil, due to rooting depth of the sinkers which occurred close to the trunk and root plate size which provide greater stiffness thus play a major component of anchorage in E. grandis. However, in P. pinaster, mechanical stability was significantly affected by trenching, possibly due to severing of lateral roots greatly altered the size of the root plate and subsequently root CSA of major lateral roots and number of sinkers, which are crucial components in anchorage of mature P. pinaster trees grown on sandy podzol soil. For protection forest species grown on steep slopes, the results showed that tree species with deep, highly branched root systems with a higher proportion of oblique roots (e.g. European beech and Silver fir) will be better anchored and provide better protective function against rockfall as compared to Norway spruce that possessed a superficial plate-like root system. The knowledge gained from this study can be utilized in selection and production of trees which are resistant to both man made or natural hazards.
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Effects of <i>Lonicera maackii</i> on soil water content and tree seedlings in eastern deciduous forestPfeiffer, Steven S. 06 August 2013 (has links)
No description available.
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