Sökresultat:
117 Uppsatser om Harvesting - Sida 3 av 8
Hållbar vattenförsörjning i områden med vattenbrist : Sustainable water supply solutions for areas affected by water shortage
In some coastal areas in Sweden water shortage sometimes appears because the withdrawal of groundwater is greater than the groundwater recharge. It creates a situation where the available groundwater is insufficient to support residents and businesses with drinking water. The high withdrawal of groundwater also creates a risk for saltwater intrusion to drinking water wells. The problem most commonly occurs during the summer when the groundwater recharge is low, but the population is high, due to tourism and summer residents.The purpose of this study was to investigate how local water supply in areas affected by water shortage can be solved as sustainable as possible. The work was divided into three parts where the first part comprised of a literature review on water systems in which four different options were investigated: artificial groundwater recharge, rainwater Harvesting, desalination and water reuse.
Anpassad skötsel - exempel på hyggesfritt skogsbruk i Mellannorrland :
Total protection is often the option chosen when protecting forests with high environmental values. An alternative to total protection is application of management regimes that do not interrupt continuity of tree cover. This study focuses mainly on continuous cover forestry (CCF) in forest stands already protected. All objects are situated in the county of Jämtland in northwest Sweden.
The purpose of the study was to attain a greater knowledge about CCF practices.
Förekomst av arteriell insufficiens : och samband till postoperativa sårinfektioner i de nedre extremiteternabland patienter som opererats med Coronary Artery Bypass Graft
The purpose of this study was to investigate the presence of arterial insufficiency in patients undergoing CABG surgery and whether arterial insufficiency is a risk factor for postoperative wound infections in the Harvesting leg. Patients who had CABG surgery were enrolled consecutively. A total of 144 patients participated in the study. During their hospital stay demographic data was recorded, as well as pre-, intra-, and postoperative tests and risk factors. The patients answered a questionnaire regarding postoperative wound infections 30 days after surgery patients answered a questionnaire regarding infections.
Mekaniserad ungskogsbehandling för röjning och skörd :
Earlier attempts at mechanising pre-commercial thinning have been met with varying degrees
of success. Most attempts have been based on techniques where residual stems are straddled.
Early treatment is essential to limit damage on residual trees. One part of the present study is an evaluation of mechanised pre-commercial thinning using the new Vimek 404R. Vimek 404R is a fairly small machine that permits selective removal of stems, making it potentially suitable also for areas overdue for pre-commercial thinning. The study established the level of performance for the machine, as well as the improvement needed to make it an economically viable option.
Fröodling av Raj- och rörsvingel i Sverige
Festulolium (Festulolium) and tall fescue (Festuca arundinacea) has not been grown inSweden over a longer period. So far there is no greater area cultivated, but the area isincreasing. Festulolium and tall fescue are expected to eventually replace meadowfescue in many leyseed mixtures to dairy cows in southern and central Sweden. Tallfescue has in recent years become popular again. Festulolium is a hybrid betweenryegrass and fescue.
Skördemetoder av industrihampa :
Hemp is an old agricultural plant and has been used for hundreds of years for making
textiles, ropes and other fibre products. In the middle of the last century the Swedish
government prohibited all growing of hemp. Natural fibres were replaced by syntetic
fibres instead. Today there is a newly awakened interest for using natural fibres from
renewable materials. Growing of industrial hemp for fiber is allowed in Sweden
again.
I want in my Paper give Swedish growers an insight of which Harvesting methods that
have been tried in Sweden and how they worked.
Utvärdering av produktionsledarens användning av Holmen Skogs datorbaserade stödsystem vid operativ planering av avverkning
The forestry companies? operational planning process is these days dependent on reliable, efficient and user-friendly computer-based support systems. This study is an evaluation of Holmen Skog's current computer-based systems.
The aim of this study is to:
? investigate the work pattern of the production managers when using the information system to plan the Harvesting operation;
? investigate the efficiency and user friendliness of the information system with the different work patterns and to find the strengths, weaknesses and bottlenecks in the current system;
? find out if the type of object, the volume, the area of the Harvesting object affects the time and work pattern;
? examine how this type of study is met by the employees and what factors that is critical to avoid feelings of intrusion.
The conclusions of the study were:
? there is a large variation between the work patterns of the production managers and the time spend to perform the operational planning;
? the mainframe computer system used by Holmen Skog is clear, has short response times, is robust and conveys relevant information;
? the computer systems are however divided in many subsystems.
Retention of stumps on wet ground at stump-harvest and its effects on saproxylic insects
Low stumps represent on their own up to 80% of the dead wood remaining on clear cuts and therefore supply suitable habitat for saproxylic insects i.e. insects depending on dead wood for their survival. Recent stump Harvesting activities threaten this substrate of ecological importance and increase the anthropogenic negative impacts on these species. Because of technical and environmental reasons (nutrient leakage, erosion) guidelines for stump Harvesting recommend to retain stumps standing in wet parts of clear cuts. However, stumps in wet positions might not be a satisfactory substrate for saproxylic insects and therefore might not be as much used as stumps in dry positions.
Utvärdering av Hultdins prototyp för portabel bro (drivningsbro) :
Stronger demand has been put on forestry to show environmental considerations during Harvesting. This is especially for crossings of brooks with sensitive elements and great care should be observed when they are to be crossed during Harvesting by logging machines. For that reason Hultdins has constructed a portable bridge that can be used for those occasions. The bridge has been developed in accordance with wishes from SCA forest, since they have a great deal of brooks in their forests and in private forests from where they buy part of their wood supply.
The aim for this report is to investigate if this portable bridge can be of interest for the forestry market. The research has been made at SCA skog in Medelpad and Norrskog in Medelpad.
Torrefaction of biomass : a comparative and kinetic study of thermal decomposition for Norway spruce stump, poplar and fuel tree chips
Stump biomass is energy rich and stump Harvesting for use as fuel become more and more
interesting in Sweden. Swedish Forest Agency (2009) has estimated that stump Harvesting in
Sweden would respond to an annual energy supply of 57 TWh/year. However, stump has not
been recognized as a bioenergy resource in Sweden. Suitable methods for pre-treatment of
stump are probably of great importance to make it accepted as fuel. It is therefore rewarding
to carry out an investigation in this area for stump.
This report represents results from a diploma project, which was aimed to develop a fixed bed
reactor for experimental study of biomass torrefaction, followed by TG analysis and kinetic
modelling employing Ozawa method and different kinetic models including one-step and
three-pseudo-component models.
Vattenvård vid slutavverkning : före och efter vattenvårdsutbildning på Stora Enso Skog, distrikt Siljan
In 2006, Stora Enso Skog implemented an education program in water management for
harvester operators, timber purchasers, cut block planners and supervisors. The focus of the
program was creating stream crossings with minimal harm to the stream and the surrounding
riparian area. This main purpose of this study was to determine the difference in work
procedures before and after participating in the program. The methodology consisted of field
studies and interviews with harvester operators and their supervisors.
The field study looked at how the streams had been crossed concerning the number of
crossings, visible damage to the stream and/or the riparian area made by the machines.
Biological parameters such as the width and dept of the stream and amount of large woody
debris in the stream were also measured.
The field result from 30 Harvesting sites showed no significant difference between sites that
had been harvested before or after the education program. But the harvester operators and
their supervisors experienced an increased concern for watersheds after the educational
program.
Stubblyftningens initiala effekt på emissioner av växthusgaser från en granmark i Småland :
In order to reduce greenhouse gas emissions from human activities fossil fuels will have to be replaced with renewable energy alternatives, such as bioenergy. Sweden has a great potential to produce bioenergy derived from forest products and there is currently a great interest within Sweden in using stumps for bioenergy production. However, the environmental consequences of the method need to be investigated before stump removal can be performed on a large scale. Swedish forest soils contain large carbon pools and a different land use may change conditions so that soils that presently act as sinks of carbon could potentially turn into sources of carbon release instead.
This study investigates the initial effects of stump Harvesting on the emissions of three greenhouse gases, carbon dioxide, methane and nitrous oxide. The emissions were measured from the soil surface in a Norway spruce forest located in the southern part of Sweden.
Faktorer som påverkar sockerförlusten vid lagring av sockerbetor : inverkan av lagringstemperatur, lagringstid och vattentillgång
This thesis is a part of the project "Sustainable Harvesting and storage of sugar beets, more sugar to practice". The work has included a large part of practical experimental work with weight measurement, graduation and storage planning. The aim of the project is to be able to see whether the cultivars react differently in different storage conditions. The project has included storage under controlled conditions to give as accurate results as possible. To be able to mimic the farmers own preconditions the samples was harvested with a conventional Holmer.This project has two parts, one concerning the nature, time and temperature on storage where a number of different cultivars where investigated during three different recording times, two different temperatures and controlled in a controlled environment.
Vitberget Skellefteå, ett kommunägt tätortsnära skogsområde ? föreningarnas och allmänhetens syn på hur skogen bör skötas
The question is who should govern and administrate a municipality owned urban forest? Should societies and the public be invited to participatory planning, who are the interested parties, could they be treated like a group and what are their opinions on administration and management? The study is carried out in a municipal owned forest Vitberget Skellefteå that is widely used by associations and individuals for recreation and training.This has led to several discussions in the local media about the management of the forest, especially in connection to Harvesting. The work undertaken here has been to identify who has any interest in the management of the area. After identifying the interested parties, a selection of the societies, schools and pre-schools that actively uses the area as well as random individuals met in the area was interviewed. The questions asked can be divided into six main groups:? Communication with the municipality?s managers for the area? Interference from other activities? Views on forest management? Views on nature conservation? The uniqueness of Vitberget? Development opportunitiesThe crucial factors identified as being needed to succeed in managing an urban forest are long-term administration, information and communication.
Skördesystem i vall, skördens storlek ochfoderkvalitet
The choice of harvest date for leys is one of the most important factors affecting the size and quality of the harvest. An early harvest gives a high nutritive value while a late harvest gives larger quantity. Today?s aim to produce high nutritive leys gives early harvest dates both in primary growth and regrowth in northern part of Sweden. The consequence is a growth in the autumn, a "third harvest".The aim of this master thesis was to study the effects of different Harvesting systems and their effect on size, feed quality, wintering and economy for conditions in the northern part of Sweden.