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291 Uppsatser om 3 Selective cutting - Sida 12 av 20
Evighetsträd
FSC (Forest Stewardship Council) is the major form of certification system in Swedish forestry today and its more than 11 million hectares are covering almost half of the total productive forest area in the country. Its regulations prescribe that at least 10 wind firm trees should be left behind after every clear cutting operation.
This study have taken place on 30 recently clearcut objects in Bergslagen, Sweden, were an inventory of the standing stock have been made. The research shows that, with 90 % security, the retained trees together contain 9-13 m3sk per hectare. Pine is the dominant tree and it covers more than half the numbers of retained trees and its volume cover 65 % of the retained trees total volume. Spruce is on second place with 30 % of the retained trees, but only 21 % of the standing stock.
Metod för urval av bäriga bestånd längs med bäriga vägar i Sveaskogs planeringsområde Råneå och Överkalix :
With increased need for flexibility in timber deliveries, forest roads become an important factor. The disintegration of roads during the spring season can be avoided if it is possible to rule cutting areas to stands with good carrying capacity along roads with good carrying capacity.
The goal with this work was to create a method to find the stands with high carrying capacity located near roads with high carrying capacity, and select them into a collection file. The method was based on Esri ArcGIS 9 and the tables that follow within that program.
The method resulted in four different themes:
1. Collections with GYL 100 that cross the bufferzon for 0, 1, 2 and 3 class roads. Result 36 collections.
2. Collections with GYL 100 and 200 that cross the bufferzon for 0, 1, 2 and 3 class roads.
Effekter av kalavverkning på mindre boreala sjöars vattenkvalitet
Forestry is an important industry in Sweden, with clear-cut as the most commonly used method for harvesting. Here the long-term impact of clear-cut on lake water quality (dissolved organic carbon (DOC), nitrogen, phosphorus and pH) has been investigated, based on 23 lakes sampled during autumn. Data for additional 15 lakes sampled for the Swedish monitoring program were also used. Lakes were classified as 5, 25, 40 and 60 year based on data of the forest age in the catchment, gathered from the Swedish national forest inventory. Clear-cut lakes were classified as 5 years (>20% of the catchment clear-cut during the last 10 years).
Utvärdering av labpilot - flödesbatteri : Experimentell studie
Results have shown that flow batteries may be a solution in the future as an effective and environmental friendly method to an energy storage system (ESS). The technology is reliable and has a high efficiency that comes with low energy losses and a long lifetime. The range of possible fields is suitable for cutting energy peaks in the power grid, by always have a ready and available energy storage that balances the production. By comparing the advantages of flow batteries with conventional batteries it is mainly the fact that they can conserve energy for a long time without being self-discharged thanks to that the storage capacity is in principle endless and limited by the size of the electrolytes tanks that makes them a great energy storage system. The batteries won?t take any damage or decrease in performance when charging or discharging it or if you exhausts it to 100 % and leave it discharged for a long time.
Observatörer för skattning av verktygspositionen hos en industrirobot : Design, simulering och experimentell verifiering
This thesis approaches the problem of estimating the arm angles of an industrial robot with flexibilities in joints and links. Due to cost-cutting efforts in the industrial robots industry, weaker components and more cost-effective structures have been introduced which in turn has led to problems with flexibilities, nonlinearities and friction. In order to handle these challenging dynamic problems and achieve high accuracy this study introduces state observers to estimate the tool position.The observers use measurements of the motor angles and an accelerometer and the different evaluated observers are based on an Extended Kalman Filter and a deterministic variant. They have been evaluated in experiments on an industrial robot with two degrees of freedom. The experimental verification shows that the state estimates can be highly accurate for medium frequency motions, ranging from 3-30Hz.
Dubbskador på Alvestakubb
Mechanical harvesting may result in timber damages leading to reduced saw log quality. The initiator of this study was VIDA ? a privately owned concern operating in the value-adding process industry of forest raw materials. The aim of this study was to examine the type and amount of damages on Alvestakubb caused by the harvester head during the cutting process. The aim was also to compare the damages caused by different types of feed rollers and to evaluate the effects of temperature on damage occurrence.
Överföring av radiocesium till potatis vid olika nedfallstidpunkter :
Agricultural land could be polluted by radioactive substances after a fallout. We would then need information about the level of contamination to decide whether the crops could be utilized as food under these circumstances. In an experiment carried out during the 1990ies the retention of 134Cs in potato haulm and the transfer to the tubers were studied. The experiment was carried out during three consecutive years. The plants were cultivated in pots under field conditions and the artificial deposition was sprayed directly onto the potato haulm at different times during the growing season.
Identitetssökande katalaner. En kvalitativ studie om katalaners flernivåidentifikation
The aim of this bachelor thesis is to study how Catalans´ identifications, with respect to their city (Barcelona), their region (Catalonia), their country (Spain) and Europe, are related to each other. Furthermore it deals with whether they use cultural or civic notations when they speak of their identification with the different territorial levels.The thesis is based on a qualitative method with interviews with ten Catalans living in Barcelona, aged from 18 to 58. The result showed that Catalans´ identifications with different territorial levels vary in how they relate to each other. This variation can be classified using three models, namely; ?The Russian doll model? which implies that the identities are ranked hierarchically, ?cross-cutting? that is people can identify themselves with the different levels depending on various situations, and also ?The marble cake model? which means that the different identities are so intertwined that they cannot be separated.
Eutanasi : en skonsam död
This work is about euthanasia and how to use it on horses, dogs and cats.
A description for each animal is done, about when it is time, why, which methods can be used and who is allowed to use them, how and where it shall be done.
The methods we have concentrated on are:
- Chemical destruction and the most common drugs for euthanatize horses, dogs and cats.
- Physical disruption of the brain activity by a captive bolt, only for horses.
The captive bolt only makes the horse unconscious and must always be followed by cutting off the vena jugularis. Then the horse dies because of loss of blood.
No matter which method used for euthanizing, the animal must be declared to be dead by the operator before other measures. The testing criteria for death: muscle relaxation and cyanosis, cessation of reflex activity and pupillary dilatation, cessation of respiratory activity and cessation of all cardiac activity.
Tillvaratagande av GROT i skärgårdsnära miljö :
The main aim of this study was to investigate and compare different methods for the extraction of forest fuel from environments close to an archipelago. The study was based on relevant literature and published reports as well as personal communications.
Forestry has traditionally been characterized by intense efforts to rationalize and mechanize the cutting technique used for timber and pulpwood. In line with the increasing importance of forestry, more concentrated efforts can be expected in the area of techniques and methods, especially for the above-mentioned product lines.
In Sweden, forestry is of major importance and the Swedish economy and standard of living have mainly been created based on the revenues generated from it. Thus, it is vital that Swedish forests are harvested in an efficient and responsible manner.
The demand for biofuel is growing and today accounts for 15% of total Swedish energy production, a share that will probably increase.
This study is based on three research questions, which are described under the heading of Aim. The results reveal that the most profitable method for handling forest fuel is the traditional one, which is also the most commonly used method in southern Sweden, namely the stockpiling of logs in a clearing by means of forwarders followed by splintering at the place from where they will be distributed.
Today, the high cost of barge transport required for the extraction of forest fuel in an archipelago environment renders such operations unprofitable.
Kvalitetsledningssystem för företag igolvbranschen
This thesis describes possibilities for Metso Paper to lower their costs of spray pipes for their pulp wash press TRPE, with maintained good functionality and quality.Information that can be used by competitors has been censored in this version of the essay.To find solutions, alternative suppliers have been contacted and asked to quote. There has also been a new spray pipe designed. The manufacturing costs of the new design have been calculated.The thesis also contains a concept generation of an alternative product to the spray pipes in installations where a high pressure washer is used.To be able to ask other manufacturers of spray pipes to quote, a demand specification based on the currently used spray pipe was made. This was then sent to two alternative suppliers.An investigation of earlier used spray pipes, and the currently used, shows that the nozzles are a big part of the total costs of the spray pipes. To attempt to reduce the nozzles high cost an concept generation was made to find the best solution for a new design.There was a request that it should be possible to change the internal brushes in the spray pipe without cutting and welding.
Kapacitets- och produktivitetsanalys förflödesoptimering
This thesis describes possibilities for Metso Paper to lower their costs of spray pipes for their pulp wash press TRPE, with maintained good functionality and quality.Information that can be used by competitors has been censored in this version of the essay.To find solutions, alternative suppliers have been contacted and asked to quote. There has also been a new spray pipe designed. The manufacturing costs of the new design have been calculated.The thesis also contains a concept generation of an alternative product to the spray pipes in installations where a high pressure washer is used.To be able to ask other manufacturers of spray pipes to quote, a demand specification based on the currently used spray pipe was made. This was then sent to two alternative suppliers.An investigation of earlier used spray pipes, and the currently used, shows that the nozzles are a big part of the total costs of the spray pipes. To attempt to reduce the nozzles high cost an concept generation was made to find the best solution for a new design.There was a request that it should be possible to change the internal brushes in the spray pipe without cutting and welding.
Socialdemokraterna, Miljöpartiet, Folkpartiet & Moderaterna i integrationsdebatten
Title: A study about conditions for leadership in knowledge-intensive firms.Authors: Cecilia Ekström and Niklas SandbergKeywords: Leadership, knowledge-intensive firm, hierarchies, followers.Background: Leadership is becoming one of our greatest social myths and is considered a total solution for many problems that occur in an organization. The view of leadership is usually from a top-down perspective, which contributes to an often underestimated view of the follower. Just as it is important to understand the leader's view of leadership, it is important to understand how employees view the structure from which the leader derives its legitimacy. The existing conditions in knowledge-intensive firms, such as autonomy, place special demands on the formal leadership.Purpose: The purpose of this study takes an employee perspective, to understand what the conditions are for formal leadership in knowledge-intensive firms.Method: A qualitative research method was used and empirical material was collected through interviews with employees in knowledge-intensive firms. The empirical material was analyzed by the respondents? mental images which were set against the theoretical framework of the thesis.Conclusions: The conditions for formal leadership in knowledge-intensive firms make it advantageous to have a leader with a withdrawn role.
Restoring biodiversity in degraded secondary rain forest in Sabah, Malaysia : natural regeneration of trees after restoration treatments
Many tropical rain forests has been lost or degraded as a result of human activities and environmental factors. Since the level of biodiversity is high in the tropics, maintaining these areas is of great importance. Forests like these are often assumed to benefit from forest restoration and rehabilitation. The INIKEA project area in Eastern Sabah, Malaysian Borneo, aims to improve biodiversity and/or species richness in the degraded forest through enrichment planting with indigenous species. The objective of this thesis was to evaluate how different treatments (liberation, gap-cluster planting and line planting) affect the biodiversity of natural regeneration in different forest types in the Rain forest Restoration Experiment, located in the INIKEA project area.
Ethernet POWERLINK drivrutin för Proview
This thesis describes possibilities for Metso Paper to lower their costs of spray pipes for their pulp wash press TRPE, with maintained good functionality and quality.Information that can be used by competitors has been censored in this version of the essay.To find solutions, alternative suppliers have been contacted and asked to quote. There has also been a new spray pipe designed. The manufacturing costs of the new design have been calculated.The thesis also contains a concept generation of an alternative product to the spray pipes in installations where a high pressure washer is used.To be able to ask other manufacturers of spray pipes to quote, a demand specification based on the currently used spray pipe was made. This was then sent to two alternative suppliers.An investigation of earlier used spray pipes, and the currently used, shows that the nozzles are a big part of the total costs of the spray pipes. To attempt to reduce the nozzles high cost an concept generation was made to find the best solution for a new design.There was a request that it should be possible to change the internal brushes in the spray pipe without cutting and welding.