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291 Uppsatser om 3 Selective cutting - Sida 6 av 20

Canine S- and M/L- cone electroretinograms

Full-field flash electroretinography is an electrodiagnostic method used to examine the function of retinal cells. Light stimulation of the eye elicits electrical potentials in the retina. By aid of a corneal electrode and a reference electrode close to the back of the eye, the electrical potentials can be recorded and presented as an electroretinogram (ERG). ERGs driven by mainly one type of cones can be used to examine the function of a single cone class. In human beings, studies have shown the cone class sensitive to light of short wavelengths, the S-cones, to be more vulnerable to acquired damage than the other cone classes (Daley et al., 1987; Gouras et al., 1993; Greenstein et al., 1989). Dogs have two cone classes, S-cones, and M/L-cones (most sensitive to medium to long wavelengths).

Natur som kultur : och betydelsen av dess berättelser

Is there such a thing as unadulterated nature? All that surrounds us is culturally modified by man somewhere along our past. But culture is only a fictitious conception itself, created in an attempt to break the world into controllable objects.So in what do we find culture? In everything? In the objects or the stories they embrace? Who chooses what?s worth saving and how to save? Choosing what is culture is made from personal, ingrained dichotomies of what?s important and what is not. A selective eye creates a distorted truth, which could have unintentional long-term effects.This thesis will give a historical account of the archaeological discipline?s development in tending to our cultural heritage.

Virkesproduktionen under 80 år i ett fältförsök i Dalarna med olika skogsskötselsystem

I Sverige är trakthyggesbruk med kalhuggning det dominerande skötselsystemetmen intresset för kalhyggesfritt skogsbruk har ökat de senaste åren. Alternativentill kalavverkning är omdiskuterade och kritiseras ofta för att inte vara lönsamma.Målet med detta examensarbete är att analysera ett långtidsförsök med olikaskogsskötselsystem och att diskutera eventuella produktionsskillnader. De fem skötselåtgärdersom undersöktes var 1) kalavverkning med plantering av gran och tall,2) naturlig föryngring under fröträd, 3) blädningsbruk, 4) dimensionsavverkningoch 5) orörd skog (referensyta). Fältförsöket ligger på Siljansfors försökspark iDalarna och anlades 1923. Alla försöksytor har en areal av 1 ha.

Trakthyggesfria skogsbrukssätt : kunskap, förutsättningar och attityder

Forestry has three main aspects to take into consideration today; economical, ecological and socio-cultural. In order to reach the broad policy goals for sustainable forest management, an increased variety of management approaches are requested. Today clear-cutting is the only method used in 96 % of the managed forests in Sweden. The Swedish National Board of Forestry has therefore initiated a project in order to investigate and develop Continuous Cover Forestry (CFF). This study is a part of this project.

Fröskörd av hampa : metoder och tekniker för fröskörd av industrihampa

Hemp is an ancient cultivated plant that came to Sweden in the 1st to 2nd Century and was particularly interesting for use for food, clothing and building materials. Over time, other applications have been developed for hemp, e.g. in energy and health products. Interesting new uses for hemp continue to be identified and this fascinating plant has incredibly versatile applications.In this project, seed production of industrial hemp in Sweden was studied and evaluated. Five different methods are described, four of which are proven under Swedish conditions.

Utformning av kylkanaler och spånrum på superturbofräsar

This thesis describes how the chip space and coolant channels are designed in today?s mills, the ideas behind the design and what is considered to be the best method of cooling. It contains ideas on how the chip space can be simplified. It contains several concepts on how the cooling could be designed for better efficiency and manufacturability. There are also suggestions on how the cooling could be stopped when the cutter isn?t cutting.

Genetic parameters affecting leg length, leg weakness, hip- and elbow conformation in domesticated dogs, in comparison with pigs

Genetic parameters for four leg conformation traits in dogs (Canis lupus familiaris) are in this literature review summarized to investigate whether selective breeding could be useful to improve purebred dogs´ health and welfare. The four traits are leg length, leg weakness, hip joint and elbow joint conformation. When summarized, the genetic parameters are compared with genetic parameters affecting in pigs (Sus scrofa). Of the four traits, hip and elbow conformations were mostly studied in dogs. However, these traits were not widely studied in pigs.

Kvävestatus och risk för nitrifikation i två avverkade skogsområden i Halland

Nitrogen deposition leads to environmental damage in areas where the nitrogen deposition is high. Southwest Sweden receives an annual nitrogen deposition of up to 20 kg N/ha. Nitrogen that is not assimilated by the vegetation is accumulated in the soil, which may lead to nitrogen saturation and an elevated risk of nitrogen leaching. Nitrogen leaching from forest areas in southern Sweden has proven to be higher than from agricultural areas, which have been thought to be the main contributors to elevated nitrogen levels in rivers and lakes. The amount of nitrogen that leaches depends on the fraction of the total nitrogen in the soil that consists of nitrate, since nitrate is easily transported through the soil.

Maskinskydd på rullriktverk

ESAB is a world leader in production of welding consumables and equipment. The company manufactures, among other things, welding electrodes. A roller straightening unit is used in the cutting process to straighten the wire, which the welding electrode consists of, by adjusting some of the rollers during operation. According to ESAB?s standard and the European machinery directives, moving parts of machinery, such as rollers of the roller straightening unit, must be out of the operator?s reach.

Identitetsskapande på Instagram : En observationsstudie om visuell självpresentation från ett genusperspektiv

  The use of social media has increased in recent years and has become a part of everyday life.  Through  the  use  of  social  media  grows  new  opportunities   for  constructing  ones identity, this enables individuals  to selective self-presentation.  The social media trend has gone from largely consisting of a linguistic communication  to become directed towards a more visual form of communication,  this encourages individuals to be more visual in their self-presentation.  This study aims to create an understanding  of how individuals  present their  identity  through  visual  self-presentation,  more  precisely  via  Instagram.  Previous research  has  shown  differences  between  men's  and  women's  use  of  social  media.

ELVEEL - grafisk identitet till klädmärke

In my project I have collaborated with Linda Larson, who is the creator behind the fashion brand Elveel. The goal was to produce an identity and a graphic profile for Elveel. The aim was that the graphic profile would act as an extension of the clothes aesthetics. I wanted to explore if I by different folding and cutting techniques, in tags and packaging, could reflect the details of the clothes expression. But also how different design elements can reflect the story behind the clothes.

Maskinskydd på rullriktverk

ESAB is a world leader in production of welding consumables and equipment. The company manufactures, among other things, welding electrodes. A roller straightening unit is used in the cutting process to straighten the wire, which the welding electrode consists of, by adjusting some of the rollers during operation. According to ESAB?s standard and the European machinery directives, moving parts of machinery, such as rollers of the roller straightening unit, must be out of the operator?s reach.

Ifrågavarande kronopark skall benämnas Skatan : en skogshistorisk analys av Ekoparken Skatan

People have utilised and influenced the boreal forest for many centuries. Prior to the industrial revolution during the 19th century, however, human use primarily only had a low impact on the forest. When the timberfrontier swept over the country, the Swedish forests came to change for ever. The study site for this thesis is situated in the northern part of the county of Västerbotten, Sweden, and has previously been a National forest. Today the area is an ecopark and the land is owned by the forest company Sveaskog.

Gallringsinventering från helikopter utrustad med profilerande laser och kamera för låghöjdsfotografering

Today Holmen Skog finds and selects suitable thinning stands using data on upper height and basal area. These figures are often based on basic forest data that has been updated with the help of growth prediction models. The problem is that these figures are not always correct. The aim of this study was to investigate if a combination of data from a profiling laser and a digital camera for low elevation photography, can be used for collecting data on number of stems per ha, tree species mixture as well as basal area weighted mean height and upper height for stands. The possibility to use these data to assess the need for thinning cutting was also investigated.Laser data and aerial photographs were collected from a helicopter operating at an approximate height of 100 meters.

Säkerhetsbrytare för Gräsklippare

This thesis describes teh solution of two problems regarding safety on powered lawnmowers; protectning the users from injury when using the lawnmower in slopes, and when cleaning the cutting blade.The task was carried out through initial studies on a representative lawnmower. A generation of ideas followed with an evaluation to select the best solution. The winning concept was further developed to reach acceptable performance. The word resulted in a functioning prototype utilising an original way of detecting inclinations without incorrect signals. It c an serve as a platform for further development into a product.The work gives insightful experience of solving real-world problems, and especially to deal with situations where several variables and their effects are unknownPlease note that several parts of the work are confidential, and have therefore been removed from the thesis..

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