Möjligheten att skapa blandskogar genom plantering av tall och gran varannan rad

Swedish forests primarily consist of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.). Scots pine grows in stands with lower site index and Norway spruce in stands with higher site index. Despite the differences both tree species can co-exist naturally in Sweden. Pine and spruce mixed stands have a higher biodiversity than monocultures. Pests and pathogens usually spread from one tree to another of the same species. A mixed forest is more resistant to pests and pathogens due to the mix of tree species, making it more difficult for pests and pathogens to spread through the stand. The disadvantages with mixed stands could be the decrease in volume production and increase of cutting costs. Important to remember is that mixed stands can spread financial risks and help forest managers move decision making into the future depending on the development of the stand. The main purpose of the thesis was to examine if Scots pine and Norway spruce planted every second row could be a way to create mixed stands in central Sweden. Ten stands owned by Sveaskog planted every second row with 2 000-2 300 pine and spruce seedlings haˉ¹ were examined. The stands were planted 2009-2012 in Hälsingland and Dalarna, the site index varied from T19 to T24 and G18 to G27. A goal was set to reach 2 000 stems haˉ¹ after pre-commercial thinning. A regression analysis showed that the number of pine stems was gradually decreasing as site index increased. Spruce stems were gradually increasing as site index was increasing. The correlation was only 5-10% however the decrease in pine stems and increase in spruce stems was significant for both tree species. Breaking point seemed to be at approximately T22 and G22 where the number of pine stems increased below T22, and the number of spruce stems increased above G22. When site index varied within the stands, it showed in number of stems per tree species selected to create future stands. Spruce was higher in number of stems in plots with higher site index and pine was higher in number of stems in plots with lower site index. Height difference between pine and spruce needed to be less than one meter for one tree species not to take over in the future stand. The mean height for all stands were within the one-meter span. In summary, planting Scots pine and Norway spruce every second row in central Sweden to create mixed species stands was successful within the site index variation in this stud

Targeting for energy efficiency and improved energy collaboration between different companies using total site analysis (TSA)

Rising fuel prices, increasing costs associated with emissions of green house gases and the threat of global warming make efficient use of energy more and more important. Industrial clusters have the potential to significantly increase energy efficiency by energy collaboration. In this paper Sweden’s largest chemical cluster is analysed using the total site analysis (TSA) method. TSA delivers targets for the amount of utility consumed and generated through excess energy recovery by the different processes. The method enables investigation of opportunities to deliver waste heat from one process to another using a common utility system. The cluster consists of 5 chemical companies producing a variety of products, including polyethylene (PE), polyvinyl chloride (PVC), amines, ethylene, oxygen/nitrogen and plasticisers. The companies already work together by exchanging material streams. In this study the potential for energy collaboration is analysed in order to reach an industrial symbiosis. The overall heating and cooling demands of the site are around 442 MW and 953 MW, respectively. 122 MW of heat is produced in boilers and delivered to the processes. TSA is used to stepwise design a site-wide utility system which improves energy efficiency. It is shown that heat recovery in the cluster can be increased by 129 MW, i.e. the current utility demand could be completely eliminated and further 7 MW excess steam can be made available. The proposed retrofitted utility system involves the introduction of a site-wide hot water circuit, increased recovery of low pressure steam and shifting of heating steam pressure to lower levels in a number heat exchangers when possible. Qualitative evaluation of the suggested measures shows that 60 MW of the savings potential could to be achieved with moderate changes to the process utility system corresponding to 50% of the heat produced from purchased fuel in the boilers of the cluster. Further analysis showed that after implementation of the suggested energy efficiency measures there is still a large excess of heat at temperatures of up to 137 °C

Prediction models to evaluate baking quality instruments for commercial wheat flour

Background and ObjectivesLoaf volume is the main indicator of wheat flour quality, but test baking has major limitations. Here, prediction models were used to evaluate which methodology best captured the baking quality in Swedish commercial wheat flour and if the chemical composition of flour increased prediction accuracy.FindingsFlour type (e.g., winter vs. spring wheat) affected prediction model results significantly. Thus, separate prediction models should be developed for each flour type. Combining data from alveograph, farinograph, and glutomatic tests with protein and damaged starch gave the best prediction results. The main loaf volume predictors were dough strength for winter wheat, stability for spring wheat, and extensibility for flour blends. The composition of protein and arabinoxylan influenced several quality parameters but did not improve loaf volume predictions.ConclusionsBest predictions were obtained for winter wheat. Spring wheat and flour blend models contained only one latent variable, indicating that protein content was the main determinant for loaf volume in these samples.Significance and NoveltyThis study is one of few using prediction models to evaluate instrument suitability to determine loaf volume. Instruments suitable for predicting quality were determined for commercial winter wheat flour, which is the main product of Swedish mills

Total Site Analysis (TSA) Stenungsund

This project was carried out in cooperation between the Division of Heat and Power Technology at Chalmers University of Technology, CIT Industriell Energianalys AB, AGA Gas AB, Akzo Nobel Sverige AB, Borealis AB, INEOS Sverige AB and Perstorp Oxo AB. A Total Site Analysis (TSA) was performed in this study which can be used as a basis for future implementations of energy system integration at the chemical cluster in Stenungsund. At first stream data (Tstart, Ttarget, Q) and data on overall utility consumption of all the processes in the cluster was collected. The analysis is based on data collected on process streams heated or cooled with utility exceeding a heat load of 300 kW. Additionally steam from by-product incineration which cannot be utilised in another way is considered as process heat. With this data the current energy system was analysed by determining steam excess and deficit at each steam level and company. After that, the data was represented in curves, the so called total site profiles (TSP) and the total site composite curves (TSC). The curves were used to determine the site pinch (the limiting factor for further integration) and to identify measures to increase heat recovery. The measures found by TSA were assessed qualitatively with respect to feasibility to determine the most attractive measures. Finally the site wide potential for cogeneration and measures for reduction of external cooling demand below ambient temperature was analysed. Main findings are presented in the following: From the stream data collected is can be seen that the total demand of hot and cold utility of the cluster is 442 MW and 953 MW respectively. By-products, which have to be incinerated on-site provide 40 MW of steam. To cover the external heat demand additional 122 MW of heat is supplied by steam/hot oil from boilers or directly by flue gas from added fuels purchased or available on site. The TSP and TSC curves show a site pinch at the 2 bar(g) steam system (132 °C). The site pinch limits the potential for heat integration. To increase energy savings by heat integration it is necessary to change the position of the site pinch. It was shown that theoretically by introducing a site-wide hot water circuit, increased recovery of 2 bar(g) steam and adjustment steam levels in several heat exchangers the pinch point can be moved so that hot utility savings of 122 MW plus excess of 7 MW steam at 85 bar(g) can be realised. Only introducing a hot water circuit can save 51 MW of steam from added fuels, which corresponds to estimated savings of 122 MSEK/year. It is possible to replace more steam by hot water, but the demand for 2 bar(g) steam is limited. Therefore a demand for low pressure steam must be created by adjusting steam levels in order to utilise more waste heat in a hot water circuit. The present delivery of heat to the district heating system is not affected by a site wide hot water circuit. There is potential for increased recovery of 33 MW of 2 bar(g) steam from process heat. This would replace the production of the same amount of steam in the boilers, worth 79 MSEK/year. A qualitative assessment on the implementation of a hot water circuit shows estimated steam savings of 55.2 MW (132 MSEK/year) with moderate changes (83.5 MW including more complex changes, 200 MSEK/year). Technically the introduction of a hot water circuit includes hot water pipes between several plants, as most of the consumers of heat are situated at the cracker site and at Perstorp but the sources are spread out across the cluster. Also piping is necessary to transfer the 2 bar(g) steam replaced by hot water to other plants with steam deficit. The practical potential for increased 2 bar(g) steam recovery is estimated to 4.2 MW (10 MSEK/year) with moderate changes and 26.6 MW including more complex changes (64 MSEK/year). Increased 2 bar(g) recovery implies the construction of steam pipes from Borealis to Perstorp and INEOS, as most of the potential steam sources are located at Borealis but Perstorp and INEOS have a demand for 2 bar(g) steam The theoretical cogeneration potential in the cluster is 19 MWel in addition to the 10 MWel generated today (additional revenue is 40 MSEK/year) assuming that steam demand at all pressure levels remains the same but the steam systems are connected with each other. A practical option to increase cogeneration with the existing equipment is to supply steam below 8.8 bar(g) produced at Borealis to INEOS, Akzo and Perstorp. This would result in additional 8.6 MWel by cogeneration in Borealis turbo-alternator (estimated revenue: 18 MSEK/year). Some process streams below ambient temperature are heated with steam. It has been shown that 6.5 MW steam is used for heating stream well below ambient temperature. This steam can be saved and the cooling energy can be recovered. This decreases the energy usage in the cooling system and also saves heating steam. Savings up to 48 MSEK/year were estimated. It has been shown that by site wide collaboration it is possible to increase heat recovery, cogeneration and utilisation of waste heat. The results from this study are the bases to identify concrete projects which contribute to cost and CO2 emissions savings. The study also shows the advantages of TSA in order to find solutions for process integration by the utility system on a site wide level

Unintentional retrieval of stereotype congruent memories

The present study investigated the prediction that the stereotype physical attractiveness produces automatic memory, this means automatic encoding and retrieval of stereotype congruent information. Furthermore, subjects' relationship between automatic memory and explicit prejudice was explored. Forty-seven subjects participated in a novel implicit memory test. After conceptual priming, they judged the valence of "face-trait word" pairs, in old and new stimuli. Reaction times and self-reported prejudice levels were recorded. Results confirmed automatic memory. However, participants failed to exhibit better automatic memory for stereotype congruent stimuli than for stereotype incongruent stimuli. Significant interactions showed that participants unintentionally retrieved positive and negative traits together with attractive faces faster. A positive trend was found between subjects' automatic memory for stereotype prejudice information and their explicit prejudice attitude. The findings support automaticity of memory

Social Influence in Stockmarkets: A Conceptual Analysis of Social Influence Processes in Stock Markets

This paper focuses on the role of social factors for booms-bubbles-busts cycles in stock markets. It is argued that indirect and direct social influences are important contributors by reinforcing stock investors’ cognitive biases exaggerated by affective influences. A review of herding research primarily undertaken by financial economists is followed by a demonstration that psychological theories of direct social influence (imitation) have bearings on the understanding of the herding phenomenon in stock markets. How to continue this research with relevance for regulations of stock markets is discussed.Social influence; stock investments; conceptual analysis

Rebaling of wrapped forage - from round bale to small bale

Många stall för hästar har bara ett fåtal djur och är ofta inte mekaniserade i samma utsträckning som stall för andra lantbruksdjur. Detta gör att det finns en efterfrågan från hästägare på ensilage eller hösilage i mindre balar, dels för att fodret ska hinna konsumeras av djuren innan det förstörs av den aeroba förskämningen, och dels för att mindre balar är lättare att hantera för hand. Pressningen av småbalar i fält är dock mer väderberoende och mer tidskrävande än att pressa storbalar, varför vissa foderproducenter istället väljer att pressa storbalar vid skörden som efter en tids lagring öppnas och pressas om till mindre balar innan försäljning. Det är dock i dagsläget oklart hur fodrets sammansättning påverkas av ompressningen. Syftet med detta examensarbete var därför att studera vilken effekt ompressning hade på kemisk och mikrobiologisk sammansättning i hösilage, samt att undersöka vilken effekt ett syrabaserat tillsatsmedel hade på konserveringsresultat och aerob lagringsstabilitet. För att undersöka dessa frågeställningar producerades totalt 13 rundbalar från samma vallskörd från en gräsvall beståndende av huvudsakligen timotej och ängsvingel. Grönmassan i sex av rundbalarna behandlades med tillsatsmedlet Addcon Kofa grain pH 5 © och i sju av rundbalarna tillsattes inget tillsatsmedel (kontroll). Efter cirka sex månaders lagring pressades tre rundbalar med tillsatsmedlet och tre rundbalar utan tillsatsmedel (kontroll) om. De ompressade och inplastade fyrkantsbalarna lagrades sedan tillsammans med de kvarvarande rundbalarna i stack utomhus i 10 veckor mellan den 17/1 och den 26-27/3 2012. Därefter öppnades nio fyrkantbalar med tillsatsmedel, nio fyrkantbalar i kontrollbehandlingen samt tre rundbalar ur vardera behandlingen för provtagning och mätning av aerob stabilitet. Den aeroba stabiliteten följdes genom att balarnas kärntemperatur mättes dagligen i 14 dagar. Prover för mikrobiologiska och kemiska analyser togs med ensilageborr vid ompressning samt vid balöppning. Grönmasseprover för analyser togs i fält vid skörd av rundbalarna. Resultaten visade att både de ompressade småbalarna och rundbalarna höll en godtagbar hygienisk kvalitet med låga till normala halter av mögel, klostridier och enterobakterier. Dock var jästhalterna högre än önskvärt för både småbalar samt de rundbalar som inte pressades om, utan lagrades tillsammans med fyrkantbalarna. Detta har dock med största sannolikhet ingen negativ effekt på djurhälsan vid utfodring, men kan potentiellt förkorta den aeroba stabiliteten hos fodret. Tillsatsmedlet hade en hämmande effekt på mjölksyrabakterier, och gav ett hösilage med lägre pH, lägre halter laktat, ammoniumkväve och etanol. Tillsatsmedlet gav även lägre halter jästsvampar än kontrollbehandlingen. Den aeroba stabiliteten var godtagbar, det tog 48 timmar för fyrkantbalarna samt 24 timmar för rundbalarna att nå 3 grader över omgivande temperatur när balarnas kärntemperatur jämfördes med omgivande dygnsmedeltemperatur. Ordentlig varmgång skedde endast i endast en småbal i kontrollbehandlingen, varför den aeroba stabiliteten ändå bedöms som relativt god. Slutsatsen av detta försök var att det är möjligt att producera ett hösilage av fullt godtagbar hygienisk kvalitet genom ompressning från storbal till småbal. Syrabaserade tillsatsmedel verkar ha en hämmande effekt på tillväxt av oönskade mikroorganismer i hösilage, varför det kan vara motiverat att använda denna tillsats vid ompressning för att motverka den negativa effekt den extra syreexponeringen vid ompressning kan ha på den hygieniska kvaliteten. Produktionskostnaderna för det ompressade hösilaget är märkbart högre än kostnaderna för hösilage i rundbal som ej pressats om, men detta behöver inte utgöra ett hinder förutsatt att betalningsvilja finns hos konsumenten.Many horse stables are small with only a few animals in each stable. These stables are also often less mechanized than stables housing other farm animals. This have created a requirement from horse-owners for silage or haylage in small bales, partly so that the bale can be fed out before the feed has been spoiled by aerobic deterioration, and partly because smaller bales are easier to handle manually than large bales. Production of small bales directly in the field is more weather-dependent and time consuming than the production of large 37 bales, why some forage producers instead choose to first produce large haylage bales during harvest, and then open the large bales with already conserved forage and rebale it into smaller bales before selling. The purpose of this experiment was to study the effect this rebaling procedure on the chemical and microbial composition of the forage, and to investigate if adding an acid-based additive to the forage resulted in a different microbial and chemical composition in the forage compared to controls, after rebaling. Also, the aerobic storage stability of opened bales was investigated, to determine if it was affected by the rebaling procedure compared to bales that were not rebaled but stored for the same period. To do this, six round bales of haylage with the additive Addcon Kofa grain pH 5© and six round bales without additive (control) was produced from the same grass crop. After six months of storage, three round bales from each treatment were opened and rebaled into small square bales that were wrapped individually. These bales together with the remaining round bales were stored in a stack outdoors for 10 weeks before all the bales were opened for sampling and determination of aerobic stability. Samples for chemical and microbial analysis were taken with a core sampler at rebaling and at opening. Aerobic storage stability was followed by measuring bale temperature daily in opened bales for 14 days. The results showed that both the small square bales and the large round bales had an acceptable hygienic quality with low to normal counts of moulds, clostridia and enterobacteria. However, the yeast counts were higher than desirable, both for the rebaled haylage in small bales and for the haylage in large bales that were stored for an equally long period as the small bales. This has, however, most likely no negative effect on animal health during feeding, but might potentially have an adverse effect on the aerobic stability. The additive suppressed the growth of lactic acid bacteria and gave a haylage with lower pH, lactate content, ammonia-nitrogen content and ethanol content compared to the control. There were also indications that the additive had a suppressing effect on the growth of yeast in the rebaled forage, compared to the yeast counts before rebaling. The aerobic stability was acceptable, both in small bales and large bales, with significant heat production in only one small bale of 18. The conclusion of this study is that it is possible to produce a haylage of adequate hygienic quality through a rebaling procedure. Acid based additives seemed to have a suppressing effect on the growth of undesired microorganisms in haylage, why it can be motivated to use these additives when rebaling forage into small bales from large bales, to counteract the negative effect the extra aerobic exposure might have on the hygienic quality. The production costs for small bales made from large bales are much higher than the costs for only making large bales. This might, however, not be an obstacle if the byers of such small bales are willing to pay for these increased production costs