Sök:

Sökresultat:

544 Uppsatser om Wood boring insects - Sida 12 av 37

Fire impact in the wood quality and a fertilization experiment in Eucalyptus plantations in Guangxi, southern China

Chinas government has a multifunctional program for a more sustainable forestry since 2000. This six key forest programs goal is to develop a more sustainable forest sector but also take environment consideration. The state forest administration in China has decided to create 5.8 million hectare of fast growing and high yield forest. Eucalyptus has showed to have good properties for pulp and timber production and therefore Eucalyptus plantations are under development in costal areas in southern China. By adding extra nutrients, growth can be enhanced in Eucalyptus plantations.

Fertilization in Eucalyptus urophylla plantations in Guangxi, southern China

StoraEnso decided in year 2002 to build a pulp mill in the province of Guangxi, southernChina, and also establish eucalyptus plantations to provide it with raw material. By 2010StoraEnso controls about 90 000 of planned 120 000 ha, out of 75 000 ha is already plantedwith Eucalyptus.By using better genetic material, improve the tending, selecting the sites more careful and byusing a proper fertilization regime StoraEnso hopes to increase the mean annual incrementfrom today?s 25 m3/ha, on bark, to 35 m3/ha. This study is one part in this work to increase themean annual increment in the plantation.This master thesis is the forth in a series, that has followed up a fertilization trial that startedin spring 2006 when the trial was laid out and treatments decided. The aim with the trial is toexamine the production potential of Eucalyptus urophylla in Guangxi, southern China.

Miljödifferentierad fastighetsskatt

It is essential to reuse- and recycles residues to decrease the amount of deposit materials and reach sustainable energy use. Two ways to work towards this is to recycle wood ashes to the forest as nutrient compensation and extract biogas from combustion of biomass.The aim with this study was to decide whether wood ashes that been used for biogas upgrading with accelerated carbonation also can be used as a nutrient compensation in the woods according to recommendations from the Swedish Forest Agency (Skogsstyrelsen).The ashes that were used in this study came from Johan Andersson who works at JTI in Uppsala, who also treated the ashes with biogas. The ashes have, in both untreated and treated condition, been analyzed in this study according to contents of elements, leaching properties, hardening properties and contents of crystalline phases, to evaluate what impact carbonation with biogas has on the ashes.The accelerated carbonation led to hardening of the ash, and decreased amount of CaO- and increased amount of CaCO3. The CO2-uptake also entails a dilution of the elements, and the content of nutrients and trace elements decreases. However the results show an indication of an uptake of S from the biogas to the ash, since the dilution had a smaller impact on S than the rest of the elements.

Orienterare, framtidens naturvårdare? : Inventering av markstörningar i samband med O-Ringen i Skåne 2014

As an increasingly rationalized forestry and agriculture have human interference in the form of tradition, grazing and use declined. There is a strong link between biodiversity and disturbance of the landscape. In sandy soils many insects and plants require exposed sand to survive while the disorder may contribute to seed dispersal in the woodlands. On behalf of O-Ringen Skåne 2014, a study of the interference from orienteering in sandy soil and the forest during competitions conducted. The aim is to clarify the interference of which orienteering runners contributes, through to inventory presence before and after the competitions in the bottom and field layer in three locations.

Insektsorsakad anafylaxi

Anafylaxi som orsakats av insektsstick är ett akut tillstånd som i vissa fall kan ha en dödlig utgång om inte rätt behandling ges i tid. Störst risk att drabbas är under sommartid samt hösten. Syftet med följande studie var att visa vilken påverkan den anafylaktiska reaktionen har i patientens dagliga liv samt vilken betydelse immunterapin har för insektsallergiska personer. Litteraturstudien bygger på åtta kvantitativa och två kvalitativa studier och granskningsmetoden som använts är Goodman. Resultatet visade att det dagliga livet hos allergiska personer för¬ändras efter allvarliga eller upprepade allergiska reaktioner samt att immunterapi var en effektiv preventions¬åtgärd mot att drabbas flera gånger av liknande reaktioner efter insektsstick..

Inverkan av torrsubstanshalt och temperatur på kompostens syrabildning :

Composting is a process in which organic matter is mineralized by microorganisms. In January 2005 landfilling of organic waste was prohibited in Sweden. With this prohibition composting has become an important alternative to handle the produced organic wastes. One problem with continuous small-scale composting is the production of organic acids that will inhibit a further composting process. The aim of these theses was to study what effects temperature and dry matter content had on the production of organics acids, and what effect the organic acids had on the mineralisation of the substrate as well as the stability during storage of the product.

Gamla tallars betydelse för biologisk mångfald på Gotland

Modern methods for managing pine (Pinus sylvestris) create homogenized forests. This decreases nature?s potential for biodiversity and might threaten species in need of different types of milieu. The main purpose of this study was to investigate how important older pine trees are for biodiversity. In the Hall-Hangvar Reserve in the north-west part of Gotland, insects collected from traps showed that more species were found in old or dead trees compared to younger pine trees.

Tillväxtreaktion hos skärmträd i högskärm av gran i Medelpad :

Different methods for shelterwood cutting have been used in differ-ent parts of Europe since the middle ages. The use of shelter wood cutting in Norway spruce (Picea abies (L.) Karst.) forests in Sweden met a revival in the early 1990s as an alternative for the dominating clear-cutting system when silvicultural costs increased dramatically for the latter. Shelterwood cutting systems involve some possible problems but also a lot of positive effects. Among the problems are increased risk of wind throw and damage of the remaining shelter trees caused by the cutting operation. Positive effects are for example a valuable growth in the remaining trees and increased biological di-versity. This study is based on a total of 79 trees from 4 different treatments in a spruce shelterwood, cut in 1994, in the middle of Sweden (62,4º N).

Analys av interna transporter och buffertlager vid Vest-Wood Sverige AB

Denna rapport är resultatet av en analys som gjorts vid Vest-Woods fabrik i Forserum under våren 2007 i syfte att reducera interna transporter. Vest-Wood AB i Forserum tillverkar dörrar för den svenska marknaden men förser också en annan fabrik (SdrFelding i Danmark) i samma koncern med dörrstommar. Materialhantering för att förse Sdr Felding fabriken med dörrstommar medför i dagsläget mycket interna transporter i Forserumsfabriken. För att klara ojämn efterfrågan från Sdr Felding fabriken samt för att kunna jämna ut sin egen produktion har Forserumsfabriken valtatt lagerföra de tolv artiklar som beställs mest frekvent från Sdr Felding fabriken. Buffertlagret vid Forserumsfabriken där artiklarna lagerförs är placerat ca 200 m från produktionen vilket medför mycket intern transport för hantering av dessa.

Utdragshållfasthet av inlimmade skruvar i limträ

In this thesis tests has been performed on the pull strength of screws glued into glulam beams.The experiment is based on the already approved method whereby the diameter of the drilled holes is the same as the screw outer diameter of 1 mm or bigger. The screws strength class shall not be less than 4.6 (EN ISO 898-1:1999, 1999).The difference in the experiments that were performed where that the drilled diameter were 1 mm smaller than the outer diameter of the screw so that the screw thread was worked into the wood.In the tests the gluing where made on M8 glulam beams. The screws where drilled at and angel of 90°tangental to the fiber direction with a diameter of 7 mm. The gluing of the screws where made in three different depths and where later exposed to pulling forces. The results showed both pulling breaks and screw breaks when they reached their maximum capacity.

Effekt av karbonatisering med biogas på aska från trädbränslen

It is essential to reuse- and recycles residues to decrease the amount of deposit materials and reach sustainable energy use. Two ways to work towards this is to recycle wood ashes to the forest as nutrient compensation and extract biogas from combustion of biomass.The aim with this study was to decide whether wood ashes that been used for biogas upgrading with accelerated carbonation also can be used as a nutrient compensation in the woods according to recommendations from the Swedish Forest Agency (Skogsstyrelsen).The ashes that were used in this study came from Johan Andersson who works at JTI in Uppsala, who also treated the ashes with biogas. The ashes have, in both untreated and treated condition, been analyzed in this study according to contents of elements, leaching properties, hardening properties and contents of crystalline phases, to evaluate what impact carbonation with biogas has on the ashes.The accelerated carbonation led to hardening of the ash, and decreased amount of CaO- and increased amount of CaCO3. The CO2-uptake also entails a dilution of the elements, and the content of nutrients and trace elements decreases. However the results show an indication of an uptake of S from the biogas to the ash, since the dilution had a smaller impact on S than the rest of the elements.

Förekomst & kostnad av kapsprickor i stormaskadad skog

The aim for this study where to investigate the frequency of cutting cracks in saw timber harvested in the storm-damaged forests in regions where the storms Hilde and Ivar hit. The idea for this work came from one of the region?s biggest actors, SCA Skog and Jämtlands district. The purpose where to find out how big proportion of the saw timber that contains cutting cracks, their financial cost in lost wood value and also give advice and suggestions on how to work against the frequency of cutting cracks. For the field-study some guidelines where used to make sure that the samples were taken under the same conditions, they were: ? The field-study must be performed under harvesting of storm-felled forest, which are horizontal/inclined trunks. ? The averaged sized tree will make it possible to harvest saw timber. ? The trunks can?t be root cut. A methodology called in Swedish ?Trissmetoden? was used because it is the most frequent used methodology in earlier performed studies and the only one that can be used I field. Under the field-study data were collected from 570 saw timber logs, 30 logs from each one of the tested harvesters.

Två nya trailerkoncept för transport av rundvirke hos Stora Enso : en analys av prestation och flexibilitet

The need for roundwood transport capacity vary throughout the year. The need during a period is influenced mainly by the volume transported the period, the number of days during which transport can be carried out, seasonal variations in road conditions and the weight of the roundwood, and the origin of the wood (private forest owners/ forest companies). The need for transport capacity generally increase during the winter and in spring, after thawing. Lack of logging trucks combined with a lack of drivers for these trucks make it hard to hire extra help during periods of increased transport capacity needs. It is also very expensive to keep logging trucks for use only during these periods. In this thesis, two new concepts based on the partial transport by truck tractors have been examined, to find out the possibility for increased performance and flexibility.

Fältmätningar av limträbalkars elasticitetsmoduler : utvärdering av tre mätmetoder

This study investigates three different methods for evaluating MOE,Modulus of Elasticity, in field measurements. The purpose is toinvestigate the possibility to use dynamic measurement methods infield measurements that hitherto (2010) has been performed with staticmethods. The objects of investigation are 20 glulam beams. The firstfield measurement took place in november 2007 and applied a staticmethod based on the standard SS-EN 408. The second measurement,described in this study, took place during summer 2010, and appliedstatic as well as dynamic methods.The MOE of wood is affected by a range different factors.

Användande av diffusionsspärr vid tilläggsisolering av äldre byggnader med trästomme

In the current situation a big part ofthe settlements that exist in Sweden isin need of renovation and energyefficiency in order to survive.Therefore, also many of the older houseswith a wooden structure are in a need ofenergy efficiency, which can be done ina variety of ways, including addinginsulation.This project deals with whether the useof a diffusion barrier or a vaporbarrier affects a wall structure byadding insulation to an older house witha timber frame. The insulation materialswhich are concidered in thisinvestigation are mineral wool and woodfiber insulation. Efforts are focused onthe effects of moisture on theseinsulation materials.To demonstrate the differences thatarise the moisture measurement programWUFI have been used to simulate avariety of wall designs. These designsare developed in consultation with theconstruction carers who are active inthe industry.Using WUFI graphs illustrating themoisture levels of the wall structureswere obtained and from these conclusionsvould be drawn. The work demonstratesthe differences that arise when using adiffusion barrier or vapor barrier inwall construction.

<- Föregående sida 12 Nästa sida ->