Sök:

Sökresultat:

681 Uppsatser om Soil moisture gradient - Sida 21 av 46

Undersökningsmetodik för klorerade lösningsmedel i marken

Chlorinated solvent are volatile organic substances that can be harmful for humans and for the environment. Examples of common chlorinated solvents are perchloroethene, PCE, and trichloroethene, TCE. Chlorinated solvents appear as contaminants in soils primarily where they have been used as washing fluids in dry-cleaning facilities or as degreasers in metal industries. Chlorinated solvents are DNAPLs (dense non-aqueous phase liquids), which means that they are not easily dissolved in water and that they sink to the bottom of the aquifer. Adsorption to soils is low so chlorinated solvents are mobile in soils.

Inventering av Maskinisten 6 och Valhall 2 på LEAX fastigheter i Köping enligt MIFO fas 1

This study is a degree project in environmental engineering at Mälardalens university. Its purpose has been to perform a risk assessment on whether or not any contaminations are present in the soil at two properties in Köping. The assessment was to be done accordingly to a method that has been set up by The Swedish Environmental Protection Agency (Naturvårdsverket). The method for investigation of contaminated sites is called MIFO. MIFO consists of two stages.

Modellerade och uppmätta kväveflöden i energiskog som bevattnas med avloppsvatten

The aim of this essay was to study the nitrogen flow in two willowplantations, at different locations in the south of Sweden, that wereirrigated with sewage. The study was also performed to compare thedifferences in nitrogen flows between two years, 1998 and 1999. The studywas made in three parts. First, the denitrification activity was measuredusing the acetylen inhibition method. Second the nitrogen flow, as well asthe water- and heat flows, were modeled through the SOIL-SOILN-modelThird; the nitrogen flow was calculated to compare with the results fromthe model.The results from the measurements were then compared with the resultsfrom the SOILN-simulations to detect differences in the denitrificationrate.

Short-term responses of the field layer vegetation in a south Swedish deciduous forest after establishment of wild boars (Sus scrofa)

Inside the south Swedish national park Dalby Söderskog, wild boars (Sus scrofa L.) have been visiting since 2010. The presence of wild boars has earlier been proven to impact both soil and vegetation characteristics, both positively and negatively. Still, there is a lack of knowledge regarding the rooting effect on the vegetation in deciduous forest within the native range. In this study, I have compared the field vegetation collected before and after the invasion of wild boars in 74 permanent experimental plots. More specifically, the study aimed to qualify the effect of wild boar rooting on cover ratio, species richness and species composition in a temperate deciduous forest.

Tekniska möjligheter för artificiell spridning av renlav :

Forestry and reindeer husbandry are entitled to use the same land for their operations. For this reason, conflicts occasionally arise between them. Soil scarification is a forestry operation which has a negative effect on the occurrence of reindeer lichen. Reindeer lichens are of crucial importance to reindeers and reindeer husbandry, especially in the winter when reindeers primarily feed on different lichen species (Cladina spp. and Cetraria spp.).

Historiska emissioner av bly och arsenik till luft från Åfors Glasbruk och deras konsekvenser för miljön.

Åfors glasswork was a company which started in 1876 and closed in 2012 due to the bad economical situation in the company. After its closure, the glasswork left behind contaminated soil with different concentrations of heavy metals such as, arsenic from arsenic trioxide, a chemical used to remove bubbles during the melting of glass, and lead oxide, a chemical used in the production of crystal glass. Crystal glass?s production occurred under 1921-1971, but emissions of lead into the air from Åfors glasswork continued until 2011, because of the artist Bertil Valliens? artglas was made in Åfors glasswork from 1970?s and onwards.The aim of this study was to estimate how much lead (Pb) and arsenic (As) that were released by Åfors Glasswork into the atmosphere during the operational period of the glasswork in comparison with how much of lead and arsenic were purchased for the company. Added to the assistance of the data from National Archives the variations in the activities of Åfors glasswork could be shown.

Implementation av webbsida för rekommendationssystem med användaruppbyggd databas

The goal of this project was to create a web-based, crowd-sourced, correlational database, that easily allowed users to submit objects and receive correlated objects as results. The webservice was created in the web development languages of HTML, CSS, PHP and Javscript, with MySQL to handle the database. Simultaneous development was kept in check with the aid of the source code management system GIT. Upon completion, the service contained several HTML-views, the ability to add and rate objects, a per-object dedicated page with information parsed from Wikipedia.org, and a view with objects ranked in accordance to the preferences specific to the current user. Roughly a month after the beginning of development, the website was publicly launched and promoted in order to collect data, and improvements were added to the website as needed.

Skattning av fordonsmassa med driftstatistik

In the automatic manual transmission system, Opticruise, the choice of gear is based on several parameters such as road incline, driving resistance and vehicle mass. Many different mass estimations are made during driving. A final vehicle mass is then used to determine the current gear. Construction vehicles are often not equipped with air suspension and can therefore not estimate the vehicle mass when standing still. If that sort of vehicle is reloaded while standing still an incorrect mass estimation will be used and as an effect of that also a wrong gear.

Kvalitetssäkring av markberednings- och planteringsuppföljning hos SCA Skog AB Jämtlands skogsförvaltning :

Quality assurance means to systematically work for better understanding of the customers needs, demands and expectations. The goal for this study was to investigate how quality can be assured in the job follow up that is made by forestry contractors after soil scarification and planting. The study consisted of a description over the current follow up process at SCA forest AB Jämtlands forest administration, analysis of current follow up situation and an investigation of follow up process made by contractors in other line of business. The first step was a statistical comparison where the own follow up made by contractors were compared with follow up made by SCA them selves over 100 stands. Two soil scarification contractors and two planting contractors carried out the silvicultural measures. The results showed that significant differences between a number of quality factors measured, for example number of approved plants or approved scarification points, average score on stand and number of totally planted plants.

Anlockning och gnag av snytbaggar (Hylobius sp.) : effekt av plantstorlek och behandling med metyljasmonat

Two field experiments were conducted in central Sweden in order to: 1) Determine a relationship between the number of approaching pine weevils (Hylobius sp.) and the number of attacks by pine weevils, in relation to the size of seedlings of Scots pine (Pinus sylvestris). 2) Determine if application of methyljasmonate (MJ) on seedlings of Scots pine will result in higher resistance towards attacks by pine weevils and/or have any effect on the number of approaching pine weevils. The field experiments were designed with two separate parts in close vicinity on the same clear cuttings: a) pitfall traps placed in patches of scarified soil that caught approaching pine weevils at 2.5 cm from the bait, which consisted of different sized seedlings of Scots pine some of which were subjected to application of MJ and b) the same type of seedlings planted out in patches of scarified soil. The first field experiment was conducted on a 1-year old clear cutting outside Uppsala in east central Sweden and the trapping part of the experiment consisted of 8 blocks with 6 treatments: 1) control, 2) small over-wintered seedling, 3) medium sized seedling, 4) medium sized seedling treated with 0.5 ml 100 mmol MJ 4 days prior to start of experiment, 5) large seedling, 6) vial with 9.5 ml of ?-pinene. The trapping experiment lasted for 6 weeks in the early summer.

Föroreningstransport i grundvatten : En modelljämförelse

This thesis compares different methods for risk assessment of a creosote contaminated site in Vansbro, Dalarna. In a complementary study the importance of using representative data for calibration and validation of stationary groundwater models is discussed. The time dependency between surface water levels and groundwater levels on the site in Vansbro is evaluated by step response analysis. The results show that the groundwater levels reflect only long-term variation in the surface water levels. Hence the use of such long-term means for calibration and validation of the stationary groundwater models is the only theoretically defendable alternative.As a first step in the comparison of risk assessment methods the degree of contamination is evaluated on the basis of generic guideline values for contaminated soils, developed by the Swedish Environmental Protection Agency.

Hackerör på Sydsvenska höglandet : vad skiljer röjningsröseområden från celtic fields, stensträngsområden och bandparcellområden?

From the pre-Roman and Roman Iron Age, a number of different fossil agrarian landscapes can be found in southern Sweden - clearance cairn areas, celtic fields, stone-wall complexes and geometrically laid-out strip fields. With two different comparative analyses, this paper tries to explain some of the differences between clearance cairn systems and the other fossil field systemsThe shape of the early Iron Age agrarian landscape varies between different provinces of southern Sweden. At Gotland, celtic field systems were laid-out before 500 BC. In Småland at the same time, areas with clearance cairns were created. How can the difference be explained? The different physical appearance of clearance cairn areas and celtic fields can be explained by the different ways to handle the ard in till and in sandy soil.

Naturlig haptisk kraftåterkoppling från volymdata

As the volumes are entering the world of computer graphics the pure volume visualisation becomes a more important tool in for example research and medical applications. But the advance in haptics --- force feedback from the computer --- is behind. In volume haptics no equal to the proxy method so popular in surface haptics has yet emerged. Some implementations of volume haptics even use surfaces as intermediate representations so that surface haptics can be used.The intention of this work was to create natural feeling haptic feedback from volumetric density data using pure volume haptics. The haptic algorithm would be implemented in Reachin API for the Reachin Desktop Display, together with other parts to build up a usable volume visualisation environment.To achieve the feeling of stiffness and friction dependent on tissue type, a proxy based method was developed.

Utredning av solenergi för drivning av sorptiv kylprocess för inomhusluften på Stockholmsarenan

Cooling down the indoor air can be done in several ways. One way is desiccantcooling which will be used at the Stockholm Arena. This method is used in airhandling units that use temperature changes and moisture fluctuations in the air. Oneof the steps is to add heat during the cooling process in order to reduce the relativehumidity of the exhaust air. The air passes thru an adsorptions rotor which thenabsorbs moisture from the supply air.

Produktutveckling av mobil förstahjälpenstation

This thesis is about a part of the marquetrytechnique, scorching. Scorching is made by heating up something, put a veneer into the heated substance and make a controlled burning. This technique is old but still used today and have according to me great potential for development. In my work I wanted to give the scorching greater room then I earlier have seen. I wanted the scorching to be the dominant ingredient for a decorative element in a piece of furniture or an interior.

<- Föregående sida 21 Nästa sida ->