668 research outputs found
Development and Demonstration of New Technology for the use of Wind Turbines on Ships
Technology to substantially reduce commercial ship fuel consumption by harnessing sea winds for
simultaneous generation of electricity and thrust, has been developed by the company PROPit AB.
The basic idea is to apply conventional wind turbine technology for the marine environment, where
the turbine will also take the function of sails. Primary target market is tankers or bulk ships with a
large and open deck space. Chalmers, in a study co-sponsored by the Swedish Energy Agency and
Chalmers Energy Centre, 2011, confirmed fuel saving estimates around 15-30 % for optimal routes,
but with higher uncertainties
Production of external mycelium by ectomycorrhizal fungi in a Norway spruce forest was reduced in response to nitrogen fertilization
A field study was carried out to evaluate the influence of N fertilization on the growth of the external mycelium of ectomycorrhizal (EM) fungi in a Norway spruce forest in SW Sweden. Nylon mesh bags filled with sand were buried in the soil for 6-18 months and the ingrowth of mycelium was used as an estimate of EM mycelial growth. Root-isolated, trenched plots were used to estimate background growth of saprotrophic fungi. Mycelial growth of EM fungi in N-treated plots was reduced to c. 50% of that in nonfertilized plots. Local addition of apatite stimulated the EM mycelial growth in N-treated plots. The negative influence of N on the growth of external EM mycelium observed earlier in laboratory studies was confirmed in the present field study. The growth of EM mycelia was not directly related to N concentration in the soil but rather to the N status of the trees, although other factors induced by the N treatment may also have influenced EM mycelial growth
Adding sustainability to salmon farming regulations : a comparative case study of salmon farming regulations and the ASC salmon standard
Food scarcity is one of the main challenges related to our planet’s growing population and changing environment. Furthermore, our current food production is aggravating and accelerating climate change, as almost 24% of global greenhouse gases derive from agriculture (Troell, Jonell, & Henriksson, 2017). Seafood is likely to become an even more important resource for animal protein than it already is, as the population grows, and the environment becomes less predictable which potentially could result in depleted yields. Aquaculture volumes have increased substantially during the last three decades, with increased production numbers from five million tons in 1980 to more than 106 million tons in 2017 (FishStat, 2013; Zhou, 2017). One species that have seen a rapid growth in production numbers is Atlantic salmon. The increased production in aquaculture has resulted in an increased environmental concern about the consequences of intensive farming. Consequentially, this has resulted in an influx of eco-certification schemes. One of which is the Aquaculture Stewardship Council (ASC). This study has compared the national/provincial legislation on aquaculture in the four biggest salmon producing regions; Norway, Chile, Scotland (UK), British Columbia (Canada) and the ASC’s standard, to compare how different the legislations are from the guidelines set up by this eco-certification scheme. The study found that the ASC standard has stricter standards than the aforementioned regions. Furthermore, this study has compared the potential sustainability effects of using national standards versus international standards for salmon farming and found that international standards have an important role to play as they have the potential to make everyone abide by the same minimum requirement. However, in order for them to have a real effect they need to be legally binding and not just be voluntary guidelines.Den globala livsmedelsförsörjningen är en av framtidens stora utmaningar. Med en växande global befolkning och med ett klimat under förändring är det svårt att veta hur livsmedelsförsörjningen i framtiden kommer att se ut. Fisk och skaldjur kommer sannolikt fortsätta växa i betydelse, eftersom det potentiellt har en mindre inverkan på klimatet än konventionellt jordbruk (Troell, Jonell, & Henriksson, 2017). Vattenbruk blir samtidigt en allt vanligare metod för att producera fisk eftersom fiskbeståndet i världens hav har minskat drastiskt de senaste årtiondena (D’amico, et al., 2016; Naylor & Burke, 2005). En av de arter som odlas flitigt är lax (Salmo Salar). Den ökade intensiteten av vattenbruk och laxodlingar har resulterat i en ökad oro för de potentiella effekter havsbruk har på lokala ekosystem och akvatiska miljöer. Det har i sin tur lett till ett ökat antal miljöcertifieringar, en av dessa är Aquaculture Stewardship Council (ASC). Den här studien jämför nationella/provinsiella lagar och policys hos de fyra största lax producerande länderna/provinserna Norge, Chile, Skottland (Storbritannien) och British Columbia (Kanada) och ASC standarden för hållbara laxodlingar. Studien visar att ASC certifieringen har striktare krav på laxodlingarna än vad respektive lag/policy har i de fyra regionerna. Vidare har den här studien fokuserat på om nationella standarder eller internationella standarder är att föredra för att uppnå en hållbar lax industri, och kommit fram till att internationella standarder är att föredra för att skapa en hög minimum standard, men att de saknar effekt då de, som i det här fallet, oftast endast är rekommendationer och inte bindande lagar
Simultaneous Visualization of Both Signaling Cascade Activity and End-Point Gene Expression in Single Cells
We have developed an approach for simultaneous detection of individual endogenous protein modifications and mRNA molecules in single cells in situ. For this purpose we combined two methods previously developed in our lab: in situ proximity ligation assay for the detection of individual protein interactions and -modifications and in situ detection of single mRNA molecules using padlock probes. As proof-of-principle, we demonstrated the utility of the method for simultaneous detection of phosphorylated PDGFRβ and DUSP6/MKP-3 mRNA molecules in individual human fibroblasts upon PDGF-BB stimulation. Further we applied drugs disrupting the PDGFRβ signaling pathway at various sites to show that this combined method can concurrently monitor the molecular effect of the drugs, i.e. inhibition of downstream signaling from the targeted node in the signaling pathway. Due to its ability to detect different types of molecules in single cells in situ the method presented here can contribute to a deeper understanding of cell-to-cell variations and can be applied to e.g. pinpoint effector sites of drugs in a signaling pathway
Do employees benefit from worker representation on corporate boards?
Do employees benefit from worker representation on corporate boards? Economists and policymakers are keenly interested in this question – especially lately, as worker representation is widely promoted as an important way to ensure the interests and views of the workers. To investigate this question, we apply a variety of research designs to administrative data from Norway. We find that a worker is paid more and faces less earnings risk if she gets a job in a firm with worker representation on the corporate board. However, these gains in wages and declines in earnings risk are not caused by worker representation per se. Instead, the wage premium and reduced earnings risk reflect that firms with worker representation are likely to be larger and unionized, and that larger and unionized firms tend to both pay a premium and provide better insurance to workers against fluctuations in firm performance. Conditional on the firm’s size and unionization rate, worker representation has little if any effect. Taken together, these findings suggest that while workers may indeed benefit from being employed in firms with worker representation, they would not benefit from legislation mandating worker representation on corporate boards
Analys av bärförmåga för vertikal- och horisontalbelastade betongpålar
This report contains a study of the structural loading capacity for driven concrete piles in cohesive soil. Two different types of models for handling horizontal loads have been investigated. The most common way in Sweden to cope with horizontal loads on piles is to drive the piles inclined in a truss pattern. The pile head is then thought to be hinged and the horizontal load is transmitted to the soil by normal force in the pile. In this model the lateral resistance of the soil is used only to stabilize the pile against buckling. If the pile head is made as a rigid joint the lateral resistance of the soil can be used to support the horizontal load. The piles can then be driven vertically. The analysis is made by hand calculating methods and the design standard used is Eurocode. For comparison a pile group analysis was carried out for the two above given methods to cope with horizontal load on piles. The result indicates that the truss pattern model with hinged joints has greater horizontal load capacity when normal forces are significant which is the case when dealing with heavy structures. For vertically driven piles with rigid joints the result indicates that they are more advantageous when vertical forces are moderate, i.e. light structures
Optimizing height measurement for the long-term forest experiments in Sweden
Information on tree height is useful for volume estimation and site productivity assessment and as such, remains one of the most important variables often measured in forest inventories. Measuring a sufficient number of sample trees requires considerable sampling effort and cost. In this study, we developed height functions for optimizing tree height measurement in the Swedish long-term forest experiments (LTFEs). Two large datasets from the LTFE databases: fitting data (from thinning, fertilisation and mixed species experiments) and validation data (tree species and spacing experiments) collected over several decades were used. The fitting and validation data comprise 133,788 and 68,440 observations, respectively, each covering a large range of growth and environmental conditions across Sweden. A multilevel nonlinear mixed-effects modelling approach was used to build the generalised height functions for Scots pine, Norway spruce, birch (Silver and Downy birch united), other conifers and other broadleaves, considering variations in heights and other stand characteristics at sample plot-level and revision-level. The response calibration of the functions was first carried out with all measured heights of the validation data, and second, using heights of one to six sample trees obtained from different tree selection strategies (diameter extremes, largest diameters, and smallest diameters). The mixed-effects height functions explained most of the height variations in the fitting dataset (pseudo R2: 0.938 - 0.970; RMSE: 0.957 - 1.363 m) without any residual trends. The validation showed that the functions accounted for 95 - 98 % of the height variation in the validation dataset, with RMSE ranging between 0.770 and 1.040 m, confirming the functions' high accuracy. We recommend the measurement of four sample tree heights based on diameter ex-tremes as the ideal threshold for response calibration. These functions and the suggested sampling technique would reduce sampling effort and inventory cost of height measurements for subsequent inventories of the LTFEs
Markförhållanden i svensk skogsmark
I denna rapport redovisas markkemiska data från den s.k. Ståndortskarteringens omdrev under åren 1993-2002. Då inventeringen 2003 bytte namn till Markinventeringen, används i rapporten fortsättningsvis detta senare namn.
Markinventeringen utförs på Riksskogstaxeringens permanenta provytor och är integrerad med denna när det gäller fältverksamheten. Markinventeringen finansieras av Naturvårds-verkets nationella miljöövervakningsprogram och SLU.
Riksskogstaxeringen och Markinventeringen utgör tillsammans en objektiv, spatialt riktad, nationell inventering av skog, mark och vegetation, som en viktig del av den nationella miljö-övervakningen av landekosystemen. Under omdrevet 1993-2002 ingick vegetationsbeskriv-ning samt lav- och alginventering i Markinventeringen. Data från dessa inventeringar redovisas dock inte i denna rapport, som huvudsakligen redovisar markförhållandena och speciellt då markkemin i svensk skogsmark
Grenseområdene Norge-Russland. Luft- og nedbørkvalitet, april 2014-mars 2015.
Smelteverkene på russisk side av den norsk-russiske grense slipper ut store mengder svoveldioksid (SO2) og tungmetaller. Dette gir forhøyede konsentrasjoner også på norsk side. Denne rapporten inngår i kartlegging av miljøbelastningen i grenseområdene og omfatter målinger av luftkvalitet, nedbørkvalitet og meteorologi
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