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87 Uppsatser om Gradient Descent (GD) - Sida 2 av 6
Tillväxt hos Husmossa (Hylocomium splendens) i boreal skog och växthus : effekter av ökad vattentillgång
Hylocomium splendens (Glittering wood-moss) is a common species in the Nordic countries and can be found in many different types of boreal forests. It usually forms dense moss carpets on the forest floor. The shoots grow in segments and new segments form annually on the previous years growth. The size of the segments is probably regulated in a high extent by local micro environmental conditions. Previous experiments suggest increased growth of H.
Små skogliga vattendrag i Värmland - Generell beskrivning, förekomst av traktorspår samt spårens inverkan på bottenfaunan :
Modern forestry requires a high degree of machine traffic for clear felling and scarification operations. The machines most frequently used are big and the traffic often results in tracks on the forest ground. There are many small streams running through a forest, in connection to logging operations, machines might cross these frequently. These crossings could result in the erosion of fine particulate inorganic matter, which ends up in the stream. The aim of this thesis was to give a general description of small forest streams of order-one in the county of Värmland and to determine the frequency of machine tracks in small streams.
Bokhögstubbar i Klåveröds strövområde : utbredning, egenskaper och betydelse för rödlistade vedlevande skalbaggar
Lack of dead wood is the main cause of decaying or loss of populations for many
forest species. To increase the amount of dead wood is a prerequisite to maintain
biodiversity in forests of northern Europe. In summer 2006 the recreation area
Klåveröd, at Söderåsen in Skåne, Sweden, has been inventoried for high stumps
(snags) of beech, (Fagus sylvatica). The result of the inventory has been compared
with data of the real estate and forest management directories from the owner,
region Skåne. The results have also been matched with the results from an
inventory of saproxylic beetles in 2005, performed with windowtraps on selected
snags both in the area and the adjacent national park Söderåsen.
594 snags were found on 747 ha.
Epiphytic lichen flora in a boreal forest chronosequence
Epifytiska lavar utgör en viktig del av floran i den boreala zonen. Några miljövariabler är kända för att styra artrikedomen och artsammansättningen av epifytiska lavar på beståndsnivå, såsom träddiversitet, beståndsålder, fuktighet och trädens barkstruktur. Skogsbränder utgör den viktigaste störningen i boreala skogar men studier på brandeffekter på epifytiska lavar är mycket få. Detta arbete undersökte artrikedomen, diversiteten och artsammansättningen av epifytiska lavar på basala delar av björkar längs en gradient av 30 skogsbeklädda öar som skiljer sig i storlek och brandhistorik i den norra boreala zonen i Sverige. Målet med studien var att undersöka hur lavfloran påverkades av östorleken och miljövariablerna längs gradienten.
Termisk analys av kompakta jordvärmesystem - Sensitivitetsanalys och korrektions faktorer baserat på fältmätningar i referensanläggningar i Östergötland
Chapter 1 defines the aim of the project and gives a general orientation about ground heat extractors. In chapter 2 physical processes that could be expected to be involved in the heat transport around a ground heat exchanger are discussed. It is shown from a literature study what amount of moisture transport due to thermal gradients there could be expected in a ground heat exchanger. The conclusion is drawn that the moisture gradient (Sr) is of same magnitude as the driving temperature gradient (°C). At the expected amount of increased moisture around the pipes the moisture transport could be considered to have a little effect on the brine temperature.
Romsk identitet i förändring : några ungdomars digitala berättelser
This study concerns digital stories told by five young Romani students and one teacher from Roma Culture Class in Stockholm, Sweden. The theoretical framework draws from theories concerning identity, culture,Romanipe, the Romani value system and social semiotics. The material for the study is the digital stories that were analyzed qualitatively. The results show that the young Roma in the study demonstrate pride in their Romani background and culture, but also signs of changes and development in their culture. Some of the participants do not show external signs of Romani traditions, for example in the ways of dressing.
Studie av koldioxidgradienter i havets ytskikt
Studie av koldioxidgradienter i havets ytskiktSofia SöderholmDenna studie bygger på ett nyligen utvecklat instrument som har mätt koldioxidkoncentrationer på tre olika djup i vattnet samt en nivå i luften. Då detta instrument var oprövat i vatten har en utvärdering av mätmetodens lämplighet för vattenmätningar utförts. Syftet med mätningarna var att undersöka ytvattnets vertikala koldioxidgradient för att med hjälp av denna kunna beskriva flödet av koldioxid mellan hav och atmosfär bättre. Detta flöde är en viktig del av den globala kolcykeln och en djupare förståelse för koldioxidflödets beteende kan i framtiden bidra till mer noggranna klimatprognoser. Hur de beräknade flödena från profilinstrumentet påverkas av temperaturgradienterna i vattnets ytskikt har även det studerats.
Minnet av 6-7 septemberhändelserna - istanbulbornas minne av upploppet mot den grekiska minoriteten
The memory of expulsions among the expelling groups has been fairly studied, and has potential to create new conflicts. This qualitative study uses in-depth interviews to describe the memory of the 6-7 September events and the Greek minority in Istanbul among a group of Turkish descent people living in Beyoglu, Istanbul. Further the study compares the memory with the written history and explains why the memories of the past are shaped according to the present. The Greek minority of Istanbul are remembered in words of friendship and neighbourliness, but these memories are rather a nostalgia of the past for present needs than an image of the past itself. The memories of the events among the studied group are dominated by the general destruction occasioned by the riots but tend to contradict the violence towards the Greek minority.
Hydrauliken i Ångersjöns fosforfällor : bestämning av flödesvägar och åtgärdsförslag för optimal fosforbindning vid avloppsrening med reaktiva filter
Discharge of untreated wastewater leads to unnaturally high levels of nitrogen and
phosphorus in rivers, lakes and the sea, which results in unbalanced ecosystems with
eutrophication and lack of oxygen. Part of the phosphorus in surface waters is coming from
on-site wastewater treatment from scattered households with unsatisfactory purification.
Blast furnace slag is a by-product from iron production, and has in laboratory trials showed good phosphorus binding capacity. To test blast furnace slag as a reactive filter media for phosphorus separation in a full scale experiment, a wastewater treatment plant has been built behind the picnic area at Ångersjön alongside the road E4 in central-eastern Sweden. The plant contains two parallel lines, one with blast furnaces slag and the other with Filtralite-P as phosphorus sorbent. Both filters have showed decreasing phosphorus purification effect with time in spite of a low wastewater load.
Utvärdering av en ny selektionsmetod för hingstsperma : med avseende på membranintegriteten och membranstabiliteten
Today, equine breeding is based on performance and conformation, resulting in a vast variation in fertility among different horses, with noticeable economic losses as a consequence. The horse breeding industry is therefore in need of methods that diagnose the spermatozoa concerning their quality and provide the best sperm for AI. The commonly used selection methods for sperm today are: centrifugation, where extender is added, the sample is centrifuged and then resuspended; swim-up self-migration; adherence separation; and density gradient centrifugation. However, none of these methods are in used routinely in practice before inseminating mares with fresh or cooled semen.
The aim of this study was to evaluate a new selection method, Single Layer Centrifugation (SLC), and its effect on sperm viability. The viability was analyzed with regard to membrane integrity and membrane stability of ejaculated spermatozoa.
Blå vägens glasbjörkar : från groning till allé
Det här projektet består av en litteraturstudie på trädformig björk (Betula) i Sverige, samt en studie av glasbjörk (B. pubescens) längs en klimatgradient genom Norra Sverige och Norge. Längs den studerade gradienten skiljer sig vegetationsperiodens längd med över en månad i den kallaste delen av gradienten jämfört med den varmaste. Frön längs gradienten har studerats med avseende på grobarhet före och efter simulerad invintring i syfte att undersöka om det finns trender i grad av frövila och grobarhet längs gradienten. Den simulerade invintringen hade en positiv effekt både på groningshastighet och på andel frön som grodde.
Bostäder i Tyresö
Min ingång i projektet var att undersöka hur man kan bo värdigt på äldre dagar och vilka behov som uppstår. Undersökningen visade att frånsett att äldre rör sig på mer begränsade ytor så är behoven inte så olika som man kan tro. Istället för att fokusera på äldre har jag därför lagt vikt på en bostad som ska klara livets prövningar oavsett om det gäller ett brutet ben, rullstoll eller ålderdom. Bostaden ska kännas trygg, stabil och beständig. Samtidigt vill jag att den ska värna om den enskilda personens privata sfär och i hela bostadsområdet finns en gradient av olika offentlighetsgrader.
Att tolka som barn : En kvalitativ studie om vuxnas mäns upplevelser av att under sin uppväxt ha fått tolka åt sina föräldrar
The purpose of this study was to within a Swedish context and from five persons of foreign descent stories study how they have been affected by interpreting for their parents during their childhood and how this has affected the relationships within the family. Studies conducted in an American context have shown that children interpreting for their parents in everyday situations are prone to undertake roles similar of a family leader. Previous studies also show an increased danger of depression among children who interpreted for their parents. The study was conducted by the use of semi-structured interviews with five male respondents with a varying ethnic background. Using Antonovsky´s theoretical formulation ?sense of coherence? we were able to determine that although our respondents during their childhood were subjected to a large amount of stressful elements they also maintained a high sense of well-being.
Skattning av fordonsmassa med driftstatistik
In the automatic manual transmission system, Opticruise, the choice of gear is based on several parameters such as road incline, driving resistance and vehicle mass. Many different mass estimations are made during driving. A final vehicle mass is then used to determine the current gear. Construction vehicles are often not equipped with air suspension and can therefore not estimate the vehicle mass when standing still. If that sort of vehicle is reloaded while standing still an incorrect mass estimation will be used and as an effect of that also a wrong gear.
Naturlig haptisk kraftåterkoppling från volymdata
As the volumes are entering the world of computer graphics the pure volume visualisation becomes a more important tool in for example research and medical applications. But the advance in haptics --- force feedback from the computer --- is behind. In volume haptics no equal to the proxy method so popular in surface haptics has yet emerged. Some implementations of volume haptics even use surfaces as intermediate representations so that surface haptics can be used.The intention of this work was to create natural feeling haptic feedback from volumetric density data using pure volume haptics. The haptic algorithm would be implemented in Reachin API for the Reachin Desktop Display, together with other parts to build up a usable volume visualisation environment.To achieve the feeling of stiffness and friction dependent on tissue type, a proxy based method was developed.