Sökresultat:
734 Uppsatser om Forestry processing - Sida 18 av 49
Mätning av axiella magnetiska läckflöden i vattenkraftsgeneratorer
This thesis describes a method of measuring axial magnetic leakage flux in an operational hydropower generator. Axial magnetic leakage flux is the magnetic flux at the ends of a rotating generator, which goes through the stator parallel to the rotor axis. This flux can cause circulating currents in the stator iron, giving rise to losses, and can in the worst case overheat a generator, causing it to melt down. To measure the axial flux, and how it affects the generator temperature, a measurement system was constructed on behalf of Vattenfall. The system consists of search coil sensors and a signal-processing unit with amplifiers and active filtering. To confirm the behaviour of the axial leakage flux and the functionality of the measurement system, a test installation was made.
Kostansvarigas uppfattningar om införandet av ekologiska livsmedel i skolmåltidsverksamheten
The purpose of this study was to examine how food managers of Östergötland County disucss around their possibilities of reaching the government´s orientation towards 25 per cent of the food - procured, prepared and cooked in the school meal - coming from certified organic production. The study was a cross-sectional study in wich a qualitative approach was used. The sample consisted six food managers in Östergötland. Data processing was done through a semantic content analysis. The result showed that involvment and intrest were significant factors for the introduction of organic food in the school meal. The three municipalities with the highest percentage of organic food used the SMART - concept.
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.).
Tallens fortsatta tillväxt i älgbetade bestånd
The Swedish Forestry Research Institute implemented an experiment which began in the year 1979 in a by moose browse damaged area in Sweden.
An audit in 2014 of the moose browsing study called ?Furudalsförsöket? is the underlay to the study's results. By comparing Scots pine stands development in relation to known damage obtained thereby gives the understanding of how browsing affects the short and long terms impacts of Scots pines quality and volume production.
The results of this year's audit reveal that the standing volumes in the undamaged and damaged areas represent a significant difference. The number and volume of the ingrown trees constitute a larger proportion of the areas that have been heavily browsed. It also proves once again that that all damage classes had a downward trend, which means that the damage is concealed with time.
Communicating ethical sourcing : the case of palm oil in the Swedish food industry
Palm oil has been used in processed food commodities since the 19th century. An increasing demand for regulating and ensuring a more sustainable palm oil production has resulted in various initiatives. However, these initiatives have received critique due to lack of compliance and insufficient revisions of palm oil plantations. The initiatives for creating an ethical, social and environmentally sustainable production are not sufficient for the Swedish industrial users of palm oil. As a result, stakeholders such as Swedish food processing companies, commit to ethical sourcing codes of conduct that go beyond the international palm oil initiatives.
Liquid diesel biofuel production in Sweden : a study of producers using forestry- or agricultural sector feedstock
The transportation sector is the only sector of the Swedish society that is still increasing the emissions of carbon dioxide and other green house gases. Diesel fuel represents one of the fuels that contributes to these emissions and the use of diesel fuels is increasing every year. The main purpose of this study was to make an estimation of the current business situation for producers of liquid diesel biofuels in Sweden such as biodiesel, synthetic diesel and crude tall diesel and examine the forces of competition of the industry today and its future prospects. The study revealed that the rivalry among the existing firms was low mainly due to the geographical spread of the companies. Moreover the success of the biodiesel industry was influenced by a long-term guarantee of the tax exempt for biofuels and by the price level of petroleum diesel.
Vad påverkar skogsägarnas naturhänsyn vid föryngringsavverkning i region Mellannorrland? :
The objective of this thesis was to investigate what influence nature conservation measures taken at regeneration felling. Factors analysed were the forest owners´ situation and their characters, and information activities from wood-suppliers and the Regional Forest Board (RFB). The inventory was performed with a posted questionnaire followed up by telephone to forest owners and a posted questionnaire to wood-buyers.
The forest owners were grouped in three strata, depending on the quality results (D- polytax inventory) of the taken forest conservation measures, and for this investigation forest owners were sampled from the population in the tree groups. In total 73 % (41/56) of the sampled forest owners answered the questionnaire
Group A (17 answers): Good judgement
Group B (19 answers): Bad judgement
Group C (5 answers): This group was formed from the forest owners that were informed, by RFB, about nature conservation measures and culture history consideration before the regeneration cutting.
Signalanalys med ATLAS
On Ericsson Ltd in Borås a wireless communication system called MINI-LINK? is produced. In order to sell their product with the best possible quality guaranty, there is a signal processing circuit called ATLAS implemented in the system. This circuit would eventually be useful in the production and for the repairs of the radio units. Our commission was to examine the possibility for this use.
Ethernet-baserat interkommunikationssystem för militära fordonssystem
The result of this master thesis report describes the advantages and the drawbacks that will arise when implementing an Ethernet based intercommunication system in military vehicles. The report presents a possible solution and describes how different sound applications will be implemented into the suggested solution. The report show that IP LAN in vehicles leads to more advantages than drawbacks. The main advantages are that all kind of media can share the same LAN and that there is a lot of knowledge of this technique in the civil area. The main drawback is about delay.
Arbetsvillkorens samband med sjukfrånvaro och sjuknärvaro : En studie av hemtjänstpersonal
Sickness absence is a measure of health and is therefore an important issue. To get a complete picture it´s important to also include in the discussion sickness presenteeism, working while ill, and voluntary absence, staying at home without illness. Working conditions have been proven to play a role for the three aspects which is why this study aims to further investigate the connections between them. The method used was secondary processing on interview data collected from two home care teams, one having a low and the other a high sickness absence. The results showed that there were big differences concerning working conditions, where the group with the high sickness absence perceived more stress, less control and less support from colleagues and superiors.
Konstruktion av elektrolytisk ozongenerator
The work has been carried out in cooperation with the company Zenit Design in Malmö. The project's goal was to restore, improve and produce an ozone generator. During the project, the authors sought relevant literature in databases, been in contact with US suppliers of fuel cell membranes, Asian suppliers for the processing of Teflon and Titanium parts in mechanical engineering and Swedish suppliers of various standard components. The authors had access to a temporary lab at Zenit and electron microscope at Halmstad University where material tests were performed. The authors have also had access to measurement equipment to measure amounts of ozone.During the work, the authors have mapped how an existing ozone generator works and then have their own development.
Vinster med björkinblandning i granbestånd i syfte att höja markens pH-värde
The soil acidification and the pH-value of the soil have been discussed for many years. Many observations of the tree species effects on the soil pH have been done.
We have discussed the effects on the soil surface pH-value with a birch (Betula spp. L.) admixture in Norway spruce stands (Picea abies L.).We have used data from the Swedish National Forest Inventory. We have also discussed how the wood production and the biodiversity can be increased in mixed stands, in according to the Swedish forestry act Skogsvårdslagen. Our sampling areas are located in Norrland, Sweden.
The results show a significant correlation between an increased birch admixture and an increased pH-value of the soil.
Stubbehandling med pergamentsvamp och urea mot sporinfektioner av rotticka i bestånd av hybridlärk
Root rot is a big hurter and a huge economic problem for the Swedish and European forestry. The severest hurter is Heterobasidion annosum (Fr.) Bref and it occurs as two different species in Sweden. Commonly referred to as the P-type (Heterobasidion annosum s.s. (Fr.) Bref.) and the S-type (Heterobasidion parviporum Niemelä & Korhonen). Therefore a lot of research has been carried out in this topic to find a solution and reduce this problem, one alternative that have shown to be profitable is stump treatment in thinnings.
Övervakningssystem för inomhusmiljöer
Övervakningssystem har haft en viktig roll i samhället under en lång period. Syftet med dessa
systemen har inte ändrats, det är alltid säkerhetsaspekten som har varit huvudpunkten.
Effektiviteten på ett övervakningssystem beror oftast på den mänskliga faktorn, någon måste
bearbeta bildflödet som spelas in för att dra definitiva slutsatser. Under senare år har dessa
övervakningssystem, i takt med teknologins utveckling, blivit mer intelligenta. Metoder som
tillämpar automatisk analysering av en given bild har introducerats, vissa av dessa tekniker
har redan hunnit bli en standard. Denna studie ska utveckla en prototyp som använder sig av
tekniken och stresstesta för att identifiera eventuella brister.
Temperature monitoring during transport of test samples
Quality is the main focus in management of all laboratories. Accurate results of the analyses are not only determined by the analytical procedure but also by preanalytical factors. In the total analytical process of clinical specimens, there are many possible preanalytical sources of error. Monetoring of temperature on test samples of the transport boxes is one way to reduce the mistakes in the preanalytical phase.In this study, four laboratories from primary health care were invited to participate. The temperature has been measured on test samples of the transport boxes being delivered to the laboratory.In three cases the temperature remained within the limits, but in the fourth case the temperature varied more than the allowed interval.