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4047 Uppsatser om Soil water content - Sida 25 av 270
Påverkande faktorer för grotens fukthalt
The aim of this study was to investigate how seasonal variations affect the quality of logging residues. The study was hosted by VIDA Energy.
Logging residues can be processed and transported within different systems. Today the dominant systems are chipping at landing and bulk transportation of logging residues. In these systems the handling of the logging residues are carried out in the same manner up to the landings.
Moisture content at the time of chipping is the primary quality parameter. Fine fractions of logging residues are strongly dependent on moisture content in storage.
Reducerad jordbearbetning : en fallstudie
This is a study made because I would like to see how much money can be saved when
reduced soil preparations is used. This is a case study, the farm is located in the north
vest part of Skåne, Sweden.
I have calculated with four different soilpreparation methods.
Alternative 1: Conventional soil preparation, the way the farm is managed today.
Alternative 2: Ploughing on depth of 12 centimeters, with a ridge packer followed with
sowing.
Alternative 3: Eco-tillage
Alternative 4: Direct drilling
The results of my study showes that Alternative 2 is the most profitable. Alternative 4 is
very good if you see to dieselexpenses and hours of work, but the yield is far to low.
If the numbers are further analized, it showes that in spring barley the differense
between Alternative 2 and Alternative 4 is at a minimum. So if there is lack of time for
one reason or another, this might be an alternative in spring barley.
The differense in how the farm is managed today and the most profitable alternative in
the study, Alternative 2 showes that it can be saved up to 60 940 SEK..
Hur kan blöt vetedrank lagras, hanteras och utfodras till mjölkkor? :
Distillers? grain is a by-product of ethanol production. Corn, wheat and barley are the grains
that are generally used in the distillery process. Distillers? grain is rich in protein and
phosphorus.
Bestämning av vattenytor med hjälp av Nätverks-RTK och totalstation : Inmätning av Karlbergsån i Grums kommun
This report is presenting an approach that can be used to measure water surfaces in difficult conditions caused by dense vegetation and lack of nearby known points. The objective was to make a contribution to necessary measures for adaptation against floods in Grums Municipality along the stream Karlbergsån, which may occur when persistent rain raises the level of the stream. Along the river there are low-lying areas prone to flooding. According to Grums Municipality, the stream may widen where the water level differences are large, to create a better flow path and to counteract flooding. Grums Municipality was also interested in survey stormwater discharges which may affect the water level in the stream.
Inverkan av Kiselhalten på Värmeutvidgningskoefficienten hos Aluminiumlegeringar
The purpose of this report is to document the experiments carried out, methods used and results gained during research into how the silicon content of an aluminium alloy affects the coefficient of thermal expansion (CTE).The goal of this paper is to better understand and to find a relation between silicon content and the coefficient of thermal expansion.Experiments were carried out using carefully prepared samples of Al Si alloys (0, 7, 10 and 20% Si content). Using these alloys, the CTE could be measured using a dilatometer.Comparative analysis carried out could map the effects of silicon content on the coefficient of thermal expansion and an equation was created. Using simple graphs and the rule of mixture method, the authors were able to build a simple tool for calculating the CTE of specific aluminum silicon alloys..
Stabilitetsberäkningar och åtgärdsförslag vid islast på Skålandammen
Hydropower is an important source of energy in Sweden and accounts for about 46 % of the total energy production. Sweden has about 1 200 hydropower plants and with the intention of raising the pressure head of the water and to store water, dams are built by the power plants. The storage reservoirs make it possible to adjust the energy production by demand and season. Dams in connection to the reservoirs are subjected to additional loading during periods of high floods or when an icecap in the winter is formed on the reservoirs. In order to maintain the dam safety, the power companies in Sweden are working with guidelines for dam safety from RIDAS.
Markavvattningsföretagens geografi och konsekvenser i Trosaåns avrinningsområde
Agricultural drainage is widely used to manage the amount of water in the ground in order to improve conditions for cultivation. However the effects of drainage companies on water regimes are considerable leading to runoff changes such as altered stream flows, peak flows and water levels. In a greater extent this could imply an increased risk for floods along affected watercourses. This study analyzes the extension of agricultural drainage within the drainage basin of Trosaån in Sweden by ArcGIS mapping. In a statistical analysis, historical variation in streamflow in relation to mean precipitation and mean temperature are investigated for the study area.
Förskolebarns tankar om vattnets kretslopp i naturen och i samhället. : skiljer sig pojkars och flickors svar åt?
AbstractThe work will give the picture of what four- and five-year-olds know about the water cycle in nature and in the society. Is there any difference depending on whether a boy or a girl is answering? The work will as well try to describe a picture of how a pre-school could plan their work on a sustainable society, science, and increased gender equality. To answer these questions the information has been received from interviews with children and by studying pre-school?s local plan. Earlier research on the area of water shows that it is important before working with a new topic to find out what knowledge the children already have, so that the process could be as worthwhile as possible.
Vattensänkningar : en analys av orsaker och effekter
There are records of lowering of the water level in a lot of the Swedish lakes from the middleof the 1700th century. The aim was gaining more areable land to meet the needs of more foodto support the expanding population. In areas with top soil which contents of clay or loam asin the southwest of Scania in southern Sweden this was proven to be a successful wayexpanding the total outcome of the harvest.The studied area in the northeast of Scania, though, consists of morain with a lot of mires -much less nutritious conditions. When the water level is lowered the atmosphere gets accessto the peat. The dissolving of the organic matter that has been suppressed by the lack ofoxygene below water level continues.
Demand and perception of fertilizer : among small-holder farmers in Kenya
Hunger is a problem in some parts of the world (www, FAO 1, 2012). The lack of food is often a result of insufficient knowledge in soil fertility management (Röing de Nowina, 2012). Ongoing hunger and malnourishment are quite prevalent in Sub-Saharan Africa and are often combined with poverty (www, FAO 1, 2012). Farming is the most common occupation in this area and the farms are often small-scale farms with subsistence crops and a few cattle. The farmers who operate these small-scale farms are economically a weak group.
Biogaspotential vid samrötningav mikroalger och blandslam från Västerås kommunala reningsverk
Because of the increasing trends in energy consumption and increased environmental awareness, greater focus has been placed on improvement and development of renewable energy sources. An already proven and accepted method is biogas production from anaerobic digestion at municipal wastewater treatment plants.In the waste water treatment process solid material and dissolved pollutants are separated from the water, forming a sludge. The sludge is separated from the process and stabilized during anaerobic digestion or aerobic aeration. Most often, mesophilic anaerobic digestion is used. Because of degradation by microorganisms, biogas with a high content of methane is formed during the digestion.
Konstruktion av pipelinebro i Charagua, Bolivia
Guazuigua is a small village in Bolivia, which has had too small water resources, especially for irrigation. A project started after some studies were made, to create a canal to provide the village with water from a nearby town. To make the canal work it had to cross a dried out river. There have been several attempts to cross these dried out rivers, but with poor results. The purpose of the report is to provide a solution for this problem.
pH-sensitivity in boreal streams ? the influence of landscape characteristics
The goal of the society to increase the proportion of renewable energy has led to an increased demand of bioenergy e.g. forest biomass. However, there are concerns that removal of biomass will lead to decreased base cation concentrations in the soils and acidification of streams. In order to find in which types of landscape removal of branches and tops could have such negative effects, this study aims to analyse the relations between pH-sensitivity and landscape variables in the Bothnia Bay water district. GIS and digital geographical data were used to analyse the landscape in subcatchments.
Översvämningsmodellering av ett dagvattensystem
Storm water management has become a more important matter as urban areas are expanding and natural areas are being exploited. As nature landscapes are being converted into hard surface areas storm water flow is affected both in terms of velocity and size. A flow increase can easily result in a flooding if the dimensions of the pipeline system are inadequate. Considering predicted upcoming climate changes, flooding?s may become more common in urban areas in the future.
Hur påverkasogräsuppkomsten av jordbearbetning :
Today it is common to spray against most weeds by using very expensive weed-killers.
The goal for every farmer is to have as low costs as possible for their use of machines and weed-killers.
Therefore it is in everyones interest to find other methods to fight the weeds.
Finding a way to reduce the rise and growth of weeds already at the preparation of the soil would lower the number of laps over the field and also decrease the amount of weed-killing dose.
Tests show that by harrow in the dark it is possible to reduce the population of weeds with up to 60%, but the normal reduction would be about 20-30%.
To verify the results above we made tests by using two different methods of preparing the soil. We tested ploughing and harrowing in daylight and during night. Later we checked the number of different weeds in areas prepared in daylight and during night.
By studying the results from the different methods used we found a considerable reduction of some kinds of weeds in areas prepared during night..