Sökresultat:
697 Uppsatser om Wood density - Sida 29 av 47
Marktillstånd och borbrist på åkermark planterad med gran i Västerbottens län :
This study was made on former agricultural areas that had been planted with spruce or pine, in the county of Västerbotten. The goal of the project was to investigate suspected deficiency of boron in these areas. Several objects have been reported for possible deficiency and some of these have the characteristic symptoms of boron-deficiency. The hypotheses are that
1) Boron deficiency is present at several of the investigated objects.
2) Planting of forest on cultivated postglacial sediments leads to a successive podzolisation with a decreasing content of organic matter in the mineral soil, due to decomposition, and a decreasing pH in the soil, even on locations that have been added lime.
To be able to confirm or reject the hypotheses a number of tests were performed.
En undersökning om fallolyckor med gångtrafikanter
The purpose of this study was to investigate different relations between the damages of falls and background variables as well as the relation between the falls and the weather condition to later be able to use this report to expand the knowledge among workers at VTI about the pedestrian fall injuries. All of the fall injuries in the data that this study is based on have occurred in Sweden during the time period between January 2003 and December 2011.To be able to answer the questions that this report is based on several statistical methods are used. The statistical methods that have been used during the making of this report are multiple linear regression, binary logistic regression, correlation analysis, association analysis and descriptive statistics as well as visual analysis.The results of the study show that women around menopause age have a tendency to get a big increase in the amount of injuries compared to men of the same age. The study also suggests that men on average tend to have a lower level of injury compared to women.Age also seems to affect both the amount of injuries and the level of injury negatively. The study suggests that the most likely reason for this is both that the intake of ?Fall Risk Increasing Medicine?, which is medicine that increases the drowsiness, is higher among older individuals as well as lower estrogen levels among older women and lower amount of testosterone among older men, which causes a loss of bone density in both sexes.The weather seems to have a strong effect on how many injuries occur but also a noticeable effect on the scale of the injury.
Preventiva åtgärder mot osteoporos och osteoporosrelaterade frakturer
Osteoporos är en sjukdom som under de senaste decennierna ökat. I Sverige inträffar det cirka 70 000 osteoporosrelaterade benbrott varje år. Den största gruppen som drabbas är kvinnor efter menopaus. Syftet var att belysa faktorer som är av betydelse för prevention av osteoporos och osteoporosrelaterade frakturer hos postmenopausala kvinnor. Metoden var en systematisk litteraturstudie bestående av 10 vetenskapliga artiklar varav 9 baserade på kvantitativ och en på kvalitativ forskning.
Biologiska behandlingsmetoder för rening av rejektvatten från biogasproduktion
In this literature review the characteristics of two free-floating macrophytes, water hyacinth (Eichhornia crassipes) and duckweed (Lemna sp.), and two microalgae, Chlorella and Scenedesmus, have been examined regarding their suitability as efficient nutrient removers in the treatment of wastewater with high levels of nutrients and suspended solids from a biogas plant in Loudden. The needs required for the plants to be able to grow in wastewater and the amounts of biomass they can produce have also been studied. The results show that Chlorella is capable of a very high uptake of nutrients in photobioreactors with high nutrient loadings. With an ammonia uptake maximum value at 10900mg/m2/d Chlorella outshines the other organisms in this study. The test organism that performed the closest to Chlorella in terms of nitrogen uptake was water hyacinth with an uptake about 1602mg/m2/d.
DEN EKONOMISKA EFFEKTEN AV ÖVERKLAGANDEN I GÖTEBORG - Kan överklaganden mot bostadsbyggnadsprojekt härledas till demografiska faktorer och vilka ekonomiska effekter kan de ge för byggföretagen?
This bachelor thesis addresses the problem of appeals against house building in Gothenburg. The thesis investigates whether there is a statistically significant relationship between demographic factors and the occurrence of approved, appealed and revoked permits for new construction of residential buildings in the ten districts of Gothenburg. This is done with a correlation analysis. The report also investigates whether there is a statistically significant regression in the same demographic factors and how these individually affect the average processing time for appeals in the districts. This study is done with a multiple regression analysis.
En jämförelse avseende beståndsgående-och stickvägsgående gallringsmaskiner
The purpose of this report is to investigate and compare the difference between stand-thinning machines and strip-road thinning machines, and how they affect the stand on behalf of future growth, theoretical economic result, wind impact, snow pressure and density of stand.
The investigation is regarding the first commercial thinning of pine stands, after pre-commercial thinning that was well conducted.
The investigation area was located near Katrineholm, Sweden. The measurements that were measured were strength of thinning and amounts of wind throws, snow-breaks and hauling damages.
The results that emerged, was that thinning with strip-road machines had a significantly higher strength of thinning over all, as compared with the stand- thinning machines (45 percent versus 30 percent).
Comparisons between wind-throws, snow-breaks and hauling damages of the stand could not establish any significant differences between the two methods that were investigated.
Conclusions, over all, were that if forest owners want to have more timber volume left for second thinning and final cut of the stand, the forest owners should choose the method with stand-thinning machines. From the point of view of gentle treatment of the stand and ground damages the choice should be the same.
However, the method with strip-road thinning machines is the most common and accessible method in Sweden. Most likely it is the most economical way to manage the stand for forest owners in present time.
If the method with stand-thinning machines is becoming more common in Sweden, it is suggested for forest owners to consider the stand-thinning method as a candidate for treatment due to economic aspects..
ALTERNATIVA ASFALTSBELÄGGNINGAR : Möjligheten att använda icke petroleumbaserade bindemedel
This report investigates the possibility to use non-petroleum based adhesive (biobitumen) in asphalt. The main reasons for replacing bitumen are the fact that oil prices are rising, the threat of peak oil and the fact that the asphalt industry is becoming more environmentally friendly.The main purpose of this report is to investigate whether there are any non-petroleum based adhesives on the market. If so, how can they be used? The questions covered are:? Are there any other alternative asphalt coatings available?? Can bio-oils be used in asphalt?? If the bio-oils can be used, what are the details their properties?? How does a cold climate affect the bio binders?? What is the Swedish asphalt industry?s opinion about bio asphalt?The project was concluded through literature studies, consultations with people in the asphalt industry and through several interviews.The conclusion of this report is that there are some existing non-petroleum based adhesives on the market. They are mainly used for bike paths, sidewalks and parkareas.
Inventering av trädbränsleaskor : en sammanställning av spridningsbar aska i södra Sverige
I takt med ökande intresse för uttag av grot så ökar också intresset för återföring av aska tillbaka till skogen. I rapporten utreds hur mycket återföringsbar aska som produceras av förbränningsanläggningar. Arbetet begränsas genom att endast förbränningsanläggningar med större kapacitet än 10 GWh träbränsle per år tas med . Dessutom sker en avgränsning geografiskt till att endast ta med anläggningar placerade söder om en tänkt linje mellan Karlstad och Stockholm.Datainsamlingen för förbränningsanläggningarnas askmängder har gjorts både med telefonintervju och enkätundersökning. Totalt har 107 förbränningsanläggningar tillfrågat.
Hunter demography, trends and correlates of hunting participation in Sweden
The concerning issue of declining number of hunters in North America is also apparent in Europe and Sweden. When the bulk of research found on human dimensions and hunting participation has almost exclusively been done in the United States, this report seeks to add to the needed knowledge on a national level focusing on the causes of hunter declines related to social factors within Sweden. Using hunter data reaching from commune, county to National level, this report describes the correlation between a number of variables and the hunting participation in Sweden.The typical Swedish hunter lives in an area with low population density, the person usually has higher education, the living situation is stable with no recent moving and there is relatively good access to forest land. Persons with weaker connection to the Swedish culture such as foreign citizens, people with foreign background and people born outside ?the Nordic countries? are less likely to start hunt or participate in hunting.A strong relationship was found between the favorite game, moose (Alces alces), and the amount of hunters participating in the hunting.
Påverkas mosippa (Pulsatilla vernalis) negativt av igenväxning?
Pulsatilla vernalis is one of several endangered plant species that benefit from wildfires and small scale disturbance events that repel competing vegetation and create open patches in the vegetation cover. Previous studies argue that Pulsatilla vernalis is decreasing in numbers due to vegetation changes associated with the decrease in wildfires, forest grazing and changes in forest management. In this study, 17 populations of P. vernalis were inventoried in order to examine if soil and/or vegetation structures affect the population structure of P. vernalis (i.e.
Ikea Loves Wood : Kommunikation vid en CSR-relaterad kris
Alltfler fo?retag drabbas av kriser som kan ha?rledas till ett oetiskt fo?rfarande. Da?rmed blir det intressant att underso?ka kopplingen mellan Corporate Social Responsibility (CSR) och kriskommunikation. Syftet med uppsatsen a?r att underso?ka hur ett fallfo?retag har kommunicerat vid en kris relaterad till CSR.
Anaerob rening vid StoraEnso Skoghalls Bruk
An analysis of a specific application of anaerobic wastewater treatment at a pulp and board mill, Stora Enso Skoghall, was carried out. A literature study was done and effluent wastewater from CTMP pulp production was analyzed. The analysis consisted of a broad constituent analysis and an anaerobic treatment trial. Results from these test where used to calculate the treatment effectiveness and resulting energy potential at the mill.The literature study and constituent analysis showed that toxicity of the water to be treated, due to wood extractives and sulphur content, was of concern. Detoxification chemicals targeting these constituents where used in the anaerobic treatment trial.
Beräkning av direktljud genom homogena betongväggar : Densitetens och tjocklekens påverkan på reduktionstalet
Today's urban centers become denser, which contributes to higher demands on sound and noise. It is therefore highly relevant to build homes with good sound environment while maintaining living space. This thesis aimed to reduce the current concrete walls and see how the mass law affects the reduction index value and flanking transmissions. Handmade calculations were calculated according to the Swedish standard SS-EN 21354-1, where only air sound was calculated.Calculations were performed on wall elements with different weights and thicknesses, and compared with results from Bastian.In Bastian calculations of flanking transmissions were also made, this was made to see the impact of the flanking transmission when changing the mass per unit area. Mass law's impact was examined by flanking transmission and the result shows that they are not affected as long as the ratio between the thickness and the density remains the same.A questionnaire survey was conducted to determine the actual sound experience; this questionnaire was conducted on three concrete buildings in Växjö.
Kloridhalter i gran utmed en depositionsgradient för havssalter :
The knowledge of the chloride content and its fluxes and patterns in trees is insufficient. Increased knowledge would be desirable, one of many reasons is to be able to more efficiently meet the problems that the substance causes in the pulp industry. The purpose of this study was to examine and describe the chloride concentration of Norwegian spruce (Picea abies L. Karst.) in the south of Sweden. Furthermore the aim was to be able to predict chloride concentration from readily measurable site factors.
Föryngring av tall med och utan skärm på Gotland
Föryngringen av skog på Gotland har historiskt sett varit problematisk under lång tid och i dagsläget används främst markberedning följt av plantering av tall. Förutsättningen för föryngring under skärm samt naturlig föryngring under fröträd som föryngringsmetod har studerats i denna rapport då det råder brist på skriftliga sammanfattningar om dessa båda metoder. Föryngringsmetoderna studerades genom fältstudier på 16 lokaler och intervjuer med verksamma inom branschen på Gotland. Naturlig föryngring visade sig ha viss framgång på norra Gotland samt fungera väl på nordöstra Fårö. Förutom på Fårö visade emellertid föryngring med markberedning och plantering bäst resultat.