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323 Uppsatser om Nitrogen removal - Sida 17 av 22
Evaluation of two fixation methods after mandibulotomy for oropharyngeal tumor removal - A retrospective study
Bakgrund. Vid tumörresektion i de orofaryngeala vävnaderna, utförs mandibulotomi för att skapa åtkomst och möjliggöra kirurgiskt avlägsnande. Allvarliga komplikationer har rapporterats i litteraturen och bidragande orsaker är den kirurgiska tekniken, strålningsterapin samt en inskränkt näringstillförsel till mandibelkroppen.
Syfte. Syftet med denna studie var att undersöka om bevarande av periost vid utförande av mandibulotomi, leder till färre patienter med komplikationer relaterade till mandibulotomin..
Metod. Patienter som genomgick mandibulotomi mellan 2003-2012 vid Skånes Universitetssjukhus granskades retrospektivt.
Removal of copper from stormwater runoff
I den ha?r studien implementeras en finita elementmetod fo?r att lo?sa optimala styrpro- blem i programvaran FEniCS. Den finita elementmetod som anva?nds a?r ha?mtad fra?n Karin Krafts doktorsavhandling Adaptive Finite Element Methods for Optimal Control Problems [2].Optimala styrproblem behandlar styrning av dynamiska system. Systemen beskrivs av en tillsta?ndsekvation och ma?let a?r att styra systemet mot ett visst tillsta?nd till en sa? la?g kostnad som mo?jligt.
Påverkan från den förväntade klimatförändringen på tillväxten i norra Sveriges skogar : En litteraturanalys
This is a literature review of how the climate change affects the forest growth innorthern Sweden. The temperature will rise about 5 °C with the largest increase in thewinter season (December - February) and the CO2level in the atmosphere is expected tobe doubled. Precipitation patterns will change and increase with 25-35 % and theprecipitation will be in form of rain rather than snow. Today the forests in northernSweden are entirely dominated by coniferous stands. This may shift with the climatechange and results in a larger number of deciduous trees, preferably birch will becomestronger and grow better and faster.
Betydelsen av kolkälla och mikrobiell fysiologisk status för temperaturresponsen (Q10) vid nedbrytning av organiskt material :
The increasing threat of climate change has led to a increased need for models to predict future climat. In these models the changes in the soil carbon pools due to changes in microbiel degradation of the organic matter can lead to both positive and negative feedback-effects. There is however a lack of consensues on the temperature respons on degradation soil organic matter. This paper aim to give a better understanding on the factors controlling the temperature respons. The factors studied were the carbon substrate qualitity and the physiological status of the microorganisms.
Increased growth in Norway spruce (Picea abies (L.) Karst.) through small annual additions of nitrogen (N) fertilizer
This project investigated how elevation and vegetation type influences variation in plant litter phenolic content and protein precipitation capacity among and within common plant species for two different vegetation types, heath and meadow, in a subarctic ecosystem in the Abisko region of northern Sweden. As nutrient availability generally decreases with increasing elevation as a result of decreasing temperature, I hypothesised that phenolic content would increase with elevation and be higher on the heath than the meadow. To test this, the total phenolic content and protein precipitation capacity was estimated in leaf litter from 13 species in both heath and meadow vegetation across an elevational gradient ranging from 500 to 1000 meters above sea level (m.a.s.l.) in the study region. The results showed that elevation and vegetation type both had a strong impact on both variables. Total phenolic concentrations decreased with elevation for the meadow, and were greater for the heath than the meadow.
Röjning på snö och röjning på barmark : effekter på produktivitet och kvarvarande bestånd
Approximately 4000-5000 hectares, of SCA´s forest land area in Västerbotten, are in need of pre-commercial thinning (PCT) every year. Within the management district, the areas annually treated with PCT must increase, in order to decrease the area with an urgent need for PCT. This can be done by employing more forest workers or entrepreneurs, by mechanized PCT or by an extended season for PCT. Positive experiences from a private forest owner, who started to carry out PCT when the first snow came and then continued for several months, gave an idea to investigate the possibilities to prolong the season of PCT.
The purpose of this experiment was to compare PCT carried out when there was snow on the ground with PCT performed when there was no snow on the ground.
Älgarås avloppsreningsverk- studie och metodisk felsökning av en biobädds BOD-rening
Wastewater contains biodegradable materials, which are often measured as BOD7.Trickling filters are sometimes used as a purification step for BOD-reduction. Atrickling filter is a tower, which is filled with a carrier material. Microorganisms growon the carrier material in the form of a biofilm. This biofilm consists mostly of bacteriathat purify water from BOD.In Älgarås? wastewater treatment plant the water is purified by a trickling filter.However the treatment plant has difficulties reaching the emission requirements forBOD.
Uthållig odling med fokus på kväveutlakning
Kväve är en viktig byggsten i allt levande på jorden, och ingår i bland annat aminosyror,proteiner och DNA. Eftersom kväve återfinns i alla växtens celler har det en avgörande roll ivåra odlingssysystem för att få skördar med bra kvalitet. Kväve utgör också en av de storamiljöbovarna inom lantbruket. Överskott av kväve i odlingar medför risk för kväveförluster.Ett stort problem är kväveutlakning, som menas det kväve som följer regnvatten ner i undrejordlager och vidare till grundvatten, vattenströmmar och hav. Kväveutlakning kan ge storakonsekvenser på miljön, och reslutera i övergödning, döda havsbottnar och oballans i våraekologiska system.
Passiva lantbrukare ? en effekt av EU:s jordbrukspolitik : en studie av ett antal faktorers påverkan på svenska passiva lantbrukares attityder till markanvändning och EU:s jordbrukspolitik
The problem with passive farmers has arised as an effect of the European Union´s common agricultural policy (CAP) and the decouplement from production-based payments. Payments to passive farmers contradict the purpose of the single payment scheme and constitute a great cost for the EU. The new contractual period after 2013 has given rise to discussions on the direction of the CAP with a purpose of increasing the efficiency of the single payment scheme, and reducing passive farming. The aim of the study is to increase the knowledge about a few factors? influence on passive farmers? attitudes towards land use and the CAP.
Vallört som växtnäringskälla : växtnäringsförsök och litteraturstudie
Russian comfrey, Symphytum x uplandicum, was tested as a plant nutrient source in a trial with tomatoes. Comfrey liquid was produced by Stiftelsen Holma i Höör. Tomato plants of the cultivar Aromata planted in a medium of soil:peat (1:1) enriched with organic nutrients and lime, were fed with comfrey liquid plus Biofer, in three different concentrations. Two different concentrations of BioRika were used as comparison, along with an unfertilized control group. In the comfrey treatment I a total amont of 1g N, 0,23 g P, 0,84 g K, was given to the tomatoes.
Påverkar jordbruk flödet av akvatiska insekter till land? : Effekter av jordbruk på akvatiskt tillflöde till land vid norrländska bäckar
Streams and riparian zone are closely linked by reciprocal flows of energy and nutrients. A large part of the transportation from water to land is in form of emerged aquatic insects. Conversion of land from forest to agriculture can greatly affect aquatic ecosystems, and due to the close link, also affect the adjacent terrestral zone. Investigating how the presence of agriculture in the surrounding area affects amounts of emergent aquatic insects gives an indication on how agriculture, in turn, may affect the terrestral enviroment. The study was preformed alongside ten streams in northern Sweden; five in landscape transformed by agriculture and five in undisturbed forest areas.
En ?terinventering och analys av den svenska populationen av svart nervmossa (Campylopus atrovirens)
Bristly swan-neck moss (Campylopus atrovirens) is in Sweden a very rare moss that only grows on a few blocks and cliffs around Gothenburg. The species can globally only be found in areas with high precipitation. Rain fall in Gothenburg has increased with a stronger greenhouse effect. Air pollution in Gothenburg has also improved. Mosses generally benefit from these conditions and this papers hypothesis is that the population of the species has grown because of these more beneficial conditions.
Analys och förbättring av en mätenhet för laddning av elfordon
Reducing the CO2-pollution, resulting from the combustion of fossil coal for energyproduction, is important to affect environmental changes. One way to achieve a reductionis to use the oxy-fuel technology. The technology uses O2 and re-circulated flue gasduring the combustion which results in a flue gas mainly consisting of CO2. The flue gascould then be compressed and stored without environmental effects. A problem thatfollows from the compression is the risk of acidification in sensitive parts of the process.Acidification can occur because of reactions following from the contact of condensedwater and sulphur- and nitrogen-oxides which are also present in the flue gas.This report compiles and evaluates the basis of a scientific unit with the purpose ofexploring the possibilities of extracting impurities of SOx and NOx from the flue gases.The dimensions of the unit are based on basic conditions, defined for an existing oxy-fuelprocess at Chalmers, and on the results of computer modelling.
Miljökonsekvenser av dagvattendamm i Skebäck, Örebro : en fallstudie hur miljöpåverkan av en dagvattendamm intill ett Natura 2000-område kan bedömas
Stormwater is surface runoff water that originates from precipitation or snowmelt and that on hardened surfaces prevents to infiltrate the ground. In city areas stormwater can consists of major amounts pollutants and when reaching a lake or watercourse it can cause damages on vegetation and animals. Therefore it is important to treat polluted stormwater before it reaches the recipient.
The municipality of Örebro have since the 90ies an extensive work with treatment of stormwater in sedimentation ponds. A new stormwater treatment project is planned in an industrial estate in Skebäck, Örebro.
Simulering av COD-fraktioner i en aktivslamanläggning vid en sulfatmassafabrik
This thesis work was made for Södra Cell Mörrums bruk in Blekinge. The purpose of the work was to develop a computer model in the simulation program Extend for the removal and balance of organic oxygen consuming substances, measured as COD (Chemical Oxygen Demand), in the new biological treatment plant in the mill. The plant produces two different pulp products, TCF- (Totally Chlorine Free) pulp and ECF- (Elementary Chlorine Free) pulp, for sale. The different bleaching procedures affect the characteristic of the wastewater and thus the effectiveness of the biological treatment plant.In the model that was developed the COD in the wastewater was divided into five different COD-fractions: soluble easily degradable (SS), soluble hardly degradable (SR), soluble inert (SI), particulate inert (XI) and particulate biomass (XB). To create the model FlowMac? was used as a base.