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534 Uppsatser om Soil mechanics - Sida 20 av 36

Kinematisk och dynamisk modellering av den haptiska enheten TAU i sex frihetsgrader

The thesis presents an optimally designed kinematic structure for a new 6-DOF haptic devicebased on TAU configuration. The configuration of the TAU-2 proposed by Suleman Khan andKjell Andersson [1] was modified and its mobility was verified by using Grübler criterion tohave a 6 DOF. Analytical kinematic models for the inverse and forward kinematics weredeveloped for the haptic TAU configuration to determine a set of optimal design parameters.Kinematic performance indices such as volume of the workspace, kinematic isotropy and payload index, were defined based on the singular values of the Jacobian matrix. The Jacobianmatrix was scaled to homogenize the physical units. The Jacobian matrix dependent on theposition and orientation of the end-effector gives local isotropy and pay load index, so globaldesign indices were defined, which represent the performance of the mechanism in the wholeworkspace.

Uppspolning och klittererosion längs Ystadkusten - Situation idag och framtida scenarier

Problemfomulering: Ystad, som är beläget längs Skånes sydkust, har länge varit utsatt för kusterosion. När det blåser över Östersjön genereras vågor som orsakar uppspolning och direkt erosion av klitterna på stranden. Ett av de mest utsatta områdena är Ystads Sandskog, beläget öster om Ystads centrum. Här karakteriseras strandprofilen av en relativt kort strand med klitter som skyddar den låglänta bakomliggande terrängen. Vid en eventuell framtida klimatförändring med högre vågor och vattenstånd riskerar den redan utsatta kuststräckan att drabbas ännu hårdare.

Askgödsling och dess lämplighet i torvmarksskogar tillhörande Sveaskog Förvaltnings AB : en litteraturstudie

During whole-tree harvesting, there is a risk that the soil will become impoverished of nutrients. To prevent this, nutrients are returned to the harvested site as wood ash. This action also reduces the risk of soil acidification. Nevertheless, the ash does not result in any increase of tree growth if it is added on mineral soils, which is where the measure is most commonly used in Sweden. Due to the lack of growth response, the interest from landowners is small, which is why ash amendment today is not done enough to compensate for the need.

Topografins inverkan på markvattenhalten i ett jordbruksdominerat avrinningsområde

Topography is an important parameter for catchment hydrology, since it is a driver for water flow. Moreover, topography serves as a basis for hydrological models, e.g. ?Top-model?, which is based on a topographical wetness index (TWI). Few studies of TWI have been conducted on agricultural catchment scale. Four fields were studied in a Swedish drained agricultural catchment in order to evaluate the influence of topography on soil wetness.

Optimering av produktionsflo?de fo?r hydraultankar : Fo?r en ba?ttre och sa?krare arbetsmiljo?

?Optimizing the workflow of hydraulic reservoir tanks? is a degree project made by Jonas Olsson, student within the faculty of technology and science, during spring semester 2012. The project comprise 22,5 ECTS.Volvo Construction Equipment, located in Arvika, was the client in this project. The mentor at Volvo CE was A?sa Barck, and the mentor at Karlstad University was Monica Jakobsson.

Grundvattensänkning till följd av järnvägstunnel genom Hallandsås : miljökonsekvenser relaterade till förändrad kväveomsättning i mark

This thesis was carried out to give some background information to a report of SLU (Swedish University of Agricultural Sciences) for the Swedish National Rail Administration (Banverket). The requested information was to provide basic data for an environmental impact assessment of the construction of the tunnel through Hallandsås. The aim with the thesis work was to discuss and quantify the leaching of nitrate and the emission of nitrous oxide from the soil at the groundwater level established through the tunnel project. The nitrogen related processes that could be affected were described and discussed. The different areas where a decreased groundwater level can cause changes in the nitrogen processes are the wet and moist areas.

Möjligheter att minska kväveutlakningen genom att anpassa kvävegödslingen till variationer inom stråsädesfält

Due to excess precipitation that cause runoff, all soils in Sweden naturally leaches nitrogen.High leaching from arable land is an environmental problem when the runoff reacheswaters. In the international agreement, Baltic Sea Action Plan, the aim is to reduce therunoff of nutrients. Sweden has agreed to reduce its load of e.g. nitrogen to the Baltic Sea.One of the proposed measures is an increased use of site-specific N-fertilization, which hasbeen shown to increase nitrogen use efficiency and therefore also reduce the nitrogen runoff.Either yields are increased with the same total amount of nitrogen, or the total quantityof nitrogen is reduced with preserved yield levels, which is profitable for the farmers.The dynamics of nitrogen leaching differs between top dressing applications above orbelow the economical optimum. There is a consensus about a difference in the dynamics,but not about its magnitude.

Den svenska sällskapsspelsmarknaden : En studie om en bransch i utveckling från 1970 till idag

This essay is about the history of the Swedish board game-industry from the 1970?s to today. The essay focuses on the companies in the business and how they change during this period and about the causes of this change. This essay aims both at accurately describing the development of the industry as well as asking the question of what influence factors from outside of the industry have upon the change during this period of time. The material used in this essay is mainly extracts from interviews with people who have been working in the industry during the period, as well as literature on the subject and product-catalogues from certain years in the time-frame.From this material I have outlined the basic history of the industry.

Förskolebarns motoriska utveckling : -Hur en förskolegård bör utformas för bästa tänkbara utveckling av barns motorik

The purpose of this study was to interview different groups of people (preschool teatcher, parents and theire childen) involved in preschool about their view on outdoor activity and children´s motoric development, and how a preschool yard should be designed to promote childrens development.All parties regard outdoor activity as very important for the development of children. They also think that the outdoor environment today is good but that it could be improved by including some trees and hills. The yard should also contain soil, sand, clay and water. The children prefer grass on the ground over other substrates. This study also gives good indications to decision makers how to build new or to reconstruct pre-school yards in the future..

Betula : arter och sorter

As birch is one of the most common trees in Sweden, and probably one of the easiest for someone who lives here to identify, it is interesting to note that most people do not know how variable the genus is and how widely it is distributed across the northern hemisphere. One can find birch growing at both high and low elevations, demanding different soil conditions and preferring varying amounts of sunlight. Many people may also be surprised to hear that the colour of the bark can vary from bight white to almost black, and different shades of pink, orange and red can also be displayed. This, together with the astonishing beauty of the genus, the important role as a pioneer in many ecological systems and the difficulty in sorting out the taxonomy of the genus, constitutes the background of this thesis. The thesis is written at the Department of Landscape Development in Alnarp, Sweden with Kenneth Lorentzon, researcher at the Swedish University of Agriculture as a supervisor. The aim of this thesis is to highlight which species and cultivars within the genus Betula could be appropriate for horticultural use in Sweden.

Evaluation of an ectomycorrhizal macrofungi as an indicator species of high conservation value pine-heath forests in northern Sweden

Since the 1950s, the development of modern rotation forestry in boreal Fennoscandia has resulted in a severe reduction of older forests, and a high degree of fragmentation among the small patches that remains of old forest. In Sweden, when performing conservation value assessments in order to identify and preserve the remaining forest habitats, the government authorities use to a significant extent a set of indicator species that indicate habitats of high biological conservation value. One species considered to indicate high conservation values in pine-heath forests is the red-listed ectomycorrhizal (EM) macrofungi Sarcodon scabrosus (Fr.) P. Karst. In the present study, the validity of using S.

Är bor nödvändigt vid skogsgödsling i Sverige?

This thesis has been made on behalf of SCA Skog AB to assess the need of boron in Swedishforest fertilization. Boron has been added to Swedish forest fertilizers since the beginning of the1980s. This makes the fertilizers more expensive and therefore has the necessity of boron inSwedish forest fertilization been raised.The Swedish bedrock generally contains small amounts of boron. The boron in the bedrock istightly bound to the mineral tourmaline and mostly unavailable for plants. This leads to that thecontribution of boron to the soil from weathering is very low besides soils with marinesediments.

Kväveläckage inom Tolångaåns dräneringsområde : modellering och åtgärdssimulering

Under de senaste 300 åren har jordbrukslandskapet i Sverige genomgått stora förändringar. I början av 1900-talet introducerades konstgödslet och efter andra världskriget ökade gödslingen dramatiskt i syfte att maximera produktionen. Detta har lett till att överskottet av kväve har spolats ut i vattendragen. I detta arbete har stor vikt lagts vid att skapa en egen kvävemodell i syfte att simulera kväveläckaget från jordbruksmarken i Tolångaåns dräneringsområde..

Kvantfysiken och den nya myten? : En studie av Fritjof Capras och Danah Zohars böcker om kvantandlighet

This study is about quantum physics and the role it can play in a religious perspective. I intend to examine how moderna physics may be related and understood as New age and Myths. My material consists of two books in the new age genre: "The Tao of Physics" by Fritjof Capra and "The Quantum Self" by Danah Zohar. My first two question to these books are which 1) religious and 2) scientific content they have. My other questions are too 3) investigate and demonstrate how these books are new age and 4) to exanine how the books can function as myths and adopt mythical features.

Spårelement i Sveriges jordbruksmark : flöden, trender och fältbalanser

Field balances based on supply and removal of trace elements from the topsoil have been calculatedfor farms specialized in crop, dairy and pig production in Sweden. Today's field balances have beencompared with the field balances of 1990 in order to examine if, and then how, the situation haschanged. Studied trace elements are arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu),mercury (Hg), manganese (Mn), nickel (Ni), lead (Pb) and zinc (Zn).The balance calculations show that the stores of Cu and Zn are depleted with an average rate of -15% and -6 % over a 100-years period on crop farms when only commercial fertilizers are being used.The concentrations of Hg and Pb tend to increase in the topsoil on crop farms with more than 3 % forHg and with 2 % for Pb in 100 years. There is today balance between supply and removal of the traceelements As, Cd, Cr, Mn and Ni. In the south of Sweden, on crop farms with sugar beets in the croprotation, one can see a decrease in the concentration of Cd in the top soil by -6 % over a period of100 years.

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