| 1. |
- Milberg, Per, et al.
(författare)
-
A burning desire for smoke? Sampling insects favoured by forestfire in the absence of fire
- 2015
-
Ingår i: Journal of Insect Conservation. - : Springer. - 1366-638X .- 1572-9753. ; 19:1, s. 55-65
-
Tidskriftsartikel (refereegranskat)abstract
- Fire-favoured insects are difficult to sampleexcept opportunistically after forest fires. Here, we tested ifsmoke from a small fire could be an efficient way to samplesuch insects. Insects were sampled over ca. 10 h hours, byhand-picking and netting on screens put up around the fire.Two specimens of the rare and redlisted Hormopeza spp.(Diptera, Empididae) were caught. Large numbers([20,000) of Microsania spp. (Diptera, Platypezidae) werecaught, but none in the absence of smoke. The numbers ofMicrosania spp. clearly peaked in late afternoon, and ashort sampling period would be sufficient if targeting onlythis taxon. Of the almost 200 species of Coleoptera, 17 %were considered as fire-favoured, contributing 9 % of thespecimens, suggesting low efficiency of the method for thisgroup. Using 23 sites differing in fire history, catches ofMicrosania spp. were unaffected by numbers and area offorest fire (preceding 5 years and within 10 km radius overthe sampling sites). In contrast, there was a weak trend forthe proportion of fire-favoured Coleoptera to increase withincreasing number of fires. To conclude, smoke as producedin our study can clearly attract fire-favoured Diptera,but smoke had only a weak effect on fire-favoured Coleopterain the study area. It is still likely that selectivelypicking specimens of species attracted to smoke is a morecost-efficient method than using, e.g., Malaise traps thatcatch indiscriminately.
|
|
| 2. |
- Gustafsson, Lena, et al.
(författare)
-
Rapid ecological response and intensified knowledge accumulation following a north European mega-fire
- 2019
-
Ingår i: Scandinavian Journal of Forest Research. - : Informa UK Limited. - 0282-7581 .- 1651-1891. ; 34:4, s. 234-253
-
Forskningsöversikt (refereegranskat)abstract
- Deepened knowledge on response of biota and ecological processes following fire is essential for a future with warmer climate and more disturbances. In 2014 the first mega-fire (13,100 ha) for at least a century in Scandinavia hit south-central Sweden, in a production forest landscape shaped by clearcutting forestry. Ecological dynamics is followed in >20 projects from universities, authorities and citizen science initiatives, rapidly accumulating substantial amounts of data. We outline projects and summarize their results during the first four years, demonstrating a rapid succession of fungi, lichens, vascular plants, birds, mammals, ticks, butterflies, beetles, and drastically altered carbon dynamics. We characterize forest operations including regeneration measures and point to patterns in pest and pathogen infestations. 8,000 ha is set aside for natural succession, with the rest harvested and managed for forest production, offering excellent opportunities for studies on salvage logging effects, already evident for birds. We demonstrate a strong regrowth of deciduous trees, and the protected part will in some decades likely develop into the largest deciduous-dominated area in boreal north Europe outside Russia. Continued studies of biodiversity and ecological processes are urgent for this unique area.
|
|
| 3. |
- Malmström, Johan
(författare)
-
Efficient Methods to Calculate Mutual Coupling between Generic Antennas on Large Platforms
- 2017
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis presents research on methods for calculating the mutual coupling between antennas. The mutual coupling between antennas is a measure of the amount of energy transmitted from one antenna that is received by another, and is a key parameter when installing antennas on platforms, such as aircraft. To avoid interference between systems connected to the antennas, the mutual coupling should be as low as possible. The risk for interference can be minimized in several ways; by designing the systems to be resistant to interference or to install the antennas in a way that makes the coupling between antennas low. This thesis focuses on the latter.Electromagnetic problems, such as finding the mutual coupling between antennas, can be calculated in simulations using commercial software. On large platforms, simulations become very computationally intensive. This thesis examines ways to efficiently calculate the mutual coupling between antennas on large platforms. The intention has been to develop methods that can be used in practical situations.One possible way to increase efficiency is to use appropriate approximations that simplify calculations. Two approximations have been evaluated; approximate wave propagation model and equivalent representations of antennas. Both of these approximations have the potential to reduced computation times, but suffer from the fact that the size of the errors introduced is not predictable. This contributes to an uncertainty in estimating the coupling between antennas that make them less interesting to use in applications. The reaction theorem, that describes the coupling as an interaction of electromagnetic fields, has been very useful in this work. Two novel formulations of the theorem have been derived that decompose fields into scattered components. It is shown that some of the components do not affect the reaction. The reaction theorem and the derived formulations have been used in two applications. The first application shows practical possibilities to calculate mutual impedance between two antennas installed on a common platform. It is also shown how the reaction theorem can be used to visualize coupling paths, which show how the coupling between the antennas is spatially distributed.The second application of the reaction theorem suggests an effective method for antenna placement on platforms that minimize the mutual impedance between antennas. The method enables field data to be reused, which significantly reduces the calculation time. Both suggested applications post-process electromagnetic field data. The field data can be determined with commercial software.The main results in this thesis are described in five articles and conference contributions that are or will be published in international scientific journals or at international conferences.
|
|
| 4. |
|
|
| 5. |
- Aguilera, Guillermo, et al.
(författare)
-
Intensive management reduces butterfly diversity over time in urban green spaces
- 2019
-
Ingår i: Urban Ecosystems. - : Springer Science and Business Media LLC. - 1083-8155 .- 1573-1642. ; 22:2, s. 335-344
-
Tidskriftsartikel (refereegranskat)abstract
- Loss and fragmentation of semi-natural grasslands have had negative consequences for grassland biodiversity, such as butterflies. Urban parks and other urban green spaces have so far largely been overlooked as suitable butterfly habitats, although they could potentially sustain diverse butterfly populations over time. We analysed the temporal change in butterfly species assemblages in urban green spaces in the city of Malmö, Southern Sweden. We studied changes in species richness and abundance of butterflies between 2006 and 2015 in 20 public urban green spaces, characterized by different management regimes. We sampled butterflies in traditional parks with intense grass cutting regimes, in semi-natural grasslands mowed only a few times per year, and in un-managed or irregularly managed ruderal sites. We found a slight increase in the total number of butterfly species in the study area, but a general decline in local species numbers in urban green spaces. Traditional urban parks had the greatest loss of species over time, and altogether the lowest number of species. In contrast, semi-natural parks and ruderal sites had higher numbers of butterfly species and also lost fewer species over time. Our study shows that intensive management strategies in urban green spaces have a negative impact on butterfly assemblages over time. We suggest that less intensive management strategies can be used to create high-quality areas for flower-visiting insects in urban green spaces, possibly in combination with planting larval host plant species, depending on the park type and design.
|
|
| 6. |
- Bauer, Silke, et al.
(författare)
-
From Agricultural Benefits to Aviation Safety : Realizing the Potential of Continent-Wide Radar Networks
- 2017
-
Ingår i: BioScience. - : Oxford University Press (OUP). - 0006-3568 .- 1525-3244. ; 67:10, s. 912-918
-
Tidskriftsartikel (refereegranskat)abstract
- Migratory animals provide a multitude of services and disservices-with benefits or costs in the order of billions of dollars annually. Monitoring, quantifying, and forecasting migrations across continents could assist diverse stakeholders in utilizing migrant services, reducing disservices, or mitigating human-wildlife conflicts. Radars are powerful tools for such monitoring as they can assess directional intensities, such as migration traffic rates, and biomass transported. Currently, however, most radar applications are local or small scale and therefore substantially limited in their ability to address large-scale phenomena. As weather radars are organized into continent-wide networks and also detect "biological targets," they could routinely monitor aerial migrations over the relevant spatial scales and over the timescales required for detecting responses to environmental perturbations. To tap these unexploited resources, a concerted effort is needed among diverse fields of expertise and among stakeholders to recognize the value of the existing infrastructure and data beyond weather forecasting.
|
|
| 7. |
- Becciu, Paolo, et al.
(författare)
-
Environmental effects on flying migrants revealed by radar
- 2019
-
Ingår i: Ecography. - : Wiley. - 0906-7590 .- 1600-0587.
-
Forskningsöversikt (refereegranskat)abstract
- Migratory animals are affected by various factors during their journeys, and the study of animal movement by radars has been instrumental in revealing key influences of the environment on flying migrants. Radars enable the simultaneous tracking of many individuals of almost all sizes within the radar range during day and night, and under low visibility conditions. We review how atmospheric conditions, geographic features and human development affect the behavior of migrating insects and birds as recorded by radars. We focus on flight initiation and termination, as well as in-flight behavior that includes changes in animal flight direction, speed and altitude. We have identified several similarities and differences in the behavioral responses of aerial migrants including an overlooked similarity in the use of thermal updrafts by very small (e.g. aphids) and very large (e.g. vultures) migrants. We propose that many aerial migrants modulate their migratory flights in relation to the interaction between atmospheric conditions and geographic features. For example, aerial migrants that encounter crosswind may terminate their flight or continue their migration and may also drift or compensate for lateral displacement depending on their position (over land, near the coast or over sea). We propose several promising directions for future research, including the development and application of algorithms for tracking insects, bats and large aggregations of animals using weather radars. Additionally, an important contribution will be the spatial expansion of aeroecological radar studies to Africa, most of Asia and South America where no such studies have been undertaken. Quantifying the role of migrants in ecosystems and specifically estimating the number of departing birds from stopover sites using low-elevation radar scans is important for quantifying migrant–habitat relationships. This information, together with estimates of population demographics and migrant abundance, can help resolve the long-term dynamics of migrant populations facing large-scale environmental changes.
|
|
| 8. |
- Hagfeldt, A., et al.
(författare)
-
Dye-sensitized photoelectrochemical cells
- 2018. - 3
-
Ingår i: McEvoy's Handbook of Photovoltaics: Fundamentals and Applications. - : Elsevier BV. ; , s. 503-565
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Production cost per peak watt of solar electricity produced is critical to various PV technologies and second-generation thin-film solar cells. The dye-sensitized solar cell (DSC), a molecular solar cell technology, has the potential to significantly lower production costs below previous PV technologies. DSC research groups have been established around the world. Integration into different products opens up new commercial opportunities for niche applications with large flexibilities in product shape, color, and transparency.
|
|
| 9. |
- Juarez-Mosqueda, Rosalba, et al.
(författare)
-
Theoretical analysis of hydrogen spillover mechanism on carbon nanotubes
- 2015
-
Ingår i: Frontiers in Chemistry. - : Frontiers Media SA. - 2296-2646. ; 3
-
Tidskriftsartikel (refereegranskat)abstract
- The spillover mechanism of molecular hydrogen on carbon nanotubes in the presence of catalytically active platinum clusters was critically and systematically investigated by using density-functional theory. Our simulation model includes a Pt-4 cluster for the catalyst nanoparticle and curved and planar circumcoronene for two exemplary single-walled carbon nanotubes (CNT), the (10,10) CNT and one of large diameter, respectively. Our results show that the H-2 molecule dissociates spontaneously on the Pt-4 cluster. However, the dissociated H atoms have to overcome a barrier of more than 2 eV to migrate from the catalyst to the CNT, even if the Pt-4 cluster is at full saturation with six adsorbed and dissociated hydrogen molecules. Previous investigations have shown that the mobility of hydrogen atoms on the CNT surface is hindered by a barrier. We find that instead the Pt-4 catalyst may move along the outer surface of the CNT with activation energy of only 0.16 eV, and that this effect offers the possibility of full hydrogenation of the CNT. Thus, although we have not found a low-energy pathway to spillover onto the CNT, we suggest, based on our calculations and calculated data reported in the literature, that in the hydrogen-spillover process the observed saturation of the CNT at hydrogen background pressure occurs through mobile Pt nanoclusters, which move on the substrate more easily than the substrate-chemisorbed hydrogens, and deposit or reattach hydrogens in the process. Initial hydrogenation of the carbon substrate, however, is thermodynamically unfavoured, suggesting that defects should play a significant role.
|
|
| 10. |
- Karlsson, Rasmus K. B., et al.
(författare)
-
Structural Changes in RuO2 during Electrochemical Hydrogen Evolution
- 2016
-
Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 120:13, s. 7094-7102
-
Tidskriftsartikel (refereegranskat)abstract
- A comprehensive theoretical study of the X-ray photoelectron shifts for RuO2 during hydrogen evolution has been performed. The shifts have been calculated using first-principles density functional theory and are compared with previous theoretical and experimental results to reconsider the proposed structural changes occurring during hydrogen evolution on RuO2. We find that during hydrogen evolution hydrogen enters the rutile RuO2 lattice and converts oxygen groups into hydroxyl groups and that this process explains the experimentally observed increase in unit cell dimensions as well as observed chemical shifts. Furthermore, carbon contamination is the most likely explanation for a set of peaks previously identified as caused by a new RuO(OH)2 phase. We find that formation of metallic Ru is just one possible explanation for another peak in the X-ray photoelectron spectrum and that explanations including conversion of RuO2 into Ru(OH)3, or removal of oxygen from Ru active surface sites, also can explain the observed shifts. (Figure Presented)
|
|
| 11. |
- Karlsson, Rasmus K. B., et al.
(författare)
-
The electrocatalytic properties of doped TiO2
- 2015
-
Ingår i: Electrochimica Acta. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0013-4686 .- 1873-3859. ; 180, s. 514-527
-
Tidskriftsartikel (refereegranskat)abstract
- To rationally control the catalytic properties of heterogeneous catalysts is the goal in heterogeneous (electro)catalysis research. Recent developments of theoretical methods based on density functional theory have enabled computational screening of catalysts, to achieve fundamental understanding of which catalyst is optimal for a certain reaction. In the present work, such screening is employed to elucidate the electrocatalytic properties of doped rutile TiO2. Electrodes based on this material are widely used in industrial production of, e.g., chlorine and sodium chlorate. The screening covers 38 different dopants, including all fourth, fifth and sixth row transition metals. Several dopants are predicted to activate TiO2, resulting in a material optimal either for the oxygen evolution reaction, or for selective chlorine evolution. The results can serve as a map for the rational design of electrocatalysts based on TiO2.
|
|
| 12. |
- Lang, Andreas, et al.
(författare)
-
Monitoring environmental effects on farmland Lepidoptera : Does necessary sampling effort vary between different bio-geographic regions in Europe?
- 2019
-
Ingår i: Ecological Indicators. - : Elsevier BV. - 1470-160X .- 1872-7034. ; 102, s. 791-800
-
Tidskriftsartikel (refereegranskat)abstract
- In agro-ecosystems, environmental monitoring is fundamental to detect and survey changes related to land use change and management practices. Butterflies and moths have often been suggested as suitable indicators for monitoring environmental effects on biodiversity in farmlands. Here, we estimated the required sample size and monitoring effort necessary to run a Lepidoptera survey in European farmland, assessing in particular if monitoring investment would differ between representative bio-geographical regions. We operated linear 1-km long transect routes in farmland of Romania, Spain and Sweden from 2013 to 2015, and recorded butterflies and burnet moths (Papilionoidea, Zygaenidae). The transects were walked back and forth four times a season, and replicated yearly. The lepidopteran diversity was high in farmlands of Romania and Spain, but comparatively low in Sweden. The coefficient of variation (CV) of recorded species number differed between countries being lowest in Sweden and highest in Spain. In general, the CV dropped above a transect length of 400–800 m, thus indicating an increase in statistical power. Assuming a non-parametric test for matched samples, power calculations were conducted with the raw count data and with log-transformed count data for comparison. When using log-transformed data, the required sample size to detect an effect was less than 10 transects per country or region (in order to detect a 10% loss of species or a decrease of 30% in total abundance). Specific subgroups of species, e.g. protected species or specific indicator groups, showed a higher variance, thus requiring a higher sample size to detect effects ranging from 12 to 16 transects (equivalent to 21–29 working days per country and year). When using original, untransformed count data a considerably larger sample size would be needed. Actual time to be invested in field work differed between countries due to contrasting regional constraints and conditions. Nevertheless, the final monitoring effort in working days was similar between countries as the factors involved balanced out each other, in particular due to the differing year-to-year variations. Our study demonstrated the feasibility of an environmental monitoring programme in arable land using farmland butterflies across Europe. We present a suitable approach and guidelines as well as the necessary effort to be invested in future Europe-wide monitoring programmes of butterflies in agro-ecosystems, based on predictions of statistical power.
|
|
| 13. |
- Maes, Dirk, et al.
(författare)
-
Integrating national Red Lists for prioritising conservation actions for European butterflies
- 2019
-
Ingår i: Journal of Insect Conservation. - : Springer Science and Business Media LLC. - 1366-638X .- 1572-9753. ; 23:2, s. 301-330
-
Tidskriftsartikel (refereegranskat)abstract
- Red Lists are very valuable tools in nature conservation at global, continental and (sub-) national scales. In an attempt to prioritise conservation actions for European butterflies, we compiled a database with species lists and Red Lists of all European countries, including the Macaronesian archipelagos (Azores, Madeira and Canary Islands). In total, we compiled national species lists for 42 countries and national Red Lists for 34 of these. The most species-rich countries in Europe are Italy, Russia and France with more than 250 species each. Endemic species are mainly found on the Macaronesian archipelagos and on the Mediterranean islands. By attributing numerical values proportionate to the threat statuses in the different national Red List categories, we calculated a mean Red List value for every country (cRLV) and a weighted Red List value for every species (wsRLV) using the square root of the country’s area as a weighting factor. Countries with the highest cRLV were industrialised (NW) European countries such as the Netherlands, Belgium, the Czech Republic and Denmark, whereas large Mediterranean countries such as Spain and Italy had the lowest cRLV. Species for which a Red List assessment was available in at least two European countries and with a relatively high wsRLV (≥ 50) are Colias myrmidone, Pseudochazara orestes, Tomares nogelii, Colias chrysotheme and Coenonympha oedippus. We compared these wsRLVs with the species statuses on the European Red List to identify possible mismatches. We discuss how this complementary method can help to prioritise butterfly conservation on the continental and/or the (sub-)national scale.
|
|
| 14. |
- Pettersson, Lars B., et al.
(författare)
-
Biogeografi sk uppföljning 2016 av dagoch nattfj ärilar inom habitatdirektivet
- 2016
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Rapporten sammanfattar fjärilsinventeringar utförda inom 2016 inom Biogeografisk Uppföljning som drivs av Naturvårdsverket. I fjällområdet kunde 64 ytor inventeras och sammanlagt noterades 80 högnordiska blåvingar på 20 ytor och 55 dvärgpärlemorfjärilar på 19 ytor. Inventeringen gav dessvärre inget fynd av fjällsilversmygare detta år. Förekomsten av tajgafjällfly undersöktes på 8 lokaler från Lycksele lappmark i söder till Torne lappmark i norr, totalt noterades 19 individer på 6 av dessa lokaler. Svartfläckig blåvinge sågs med 157 individer på 30 inventerade lokaler och tillsammans med data från Svensk Dagfjärilsövervakning täcktes en stor del av artens förekomstområde. Brun gräsfjäril inventerades på 35 lokaler i Dalarna, Värmland och Västra Götaland och resulterade i totalt 552 observerade individer. Asknät- och väddnätfjäril inventeras med räkning av larvkolonier i augustiseptember. På 97 lokaler som inventerades noterades 4867 larvkolonier av väddnätfjäril. Asknätfjäril inventerades på 5 lokaler i Uppsala län, 8 områden i Örebro län samt 21 lokaler i Stockholm med totalt 870 noterade kolonier. Mnemosynefjäril inventerades på 32 lokaler i Blekinge, Stockholm, Uppsala och Västernorrlands län med totalt 585 noterade individer. Pilotförsök med inventeringar av apollofjäril genomfördes under 2016 i Kalmar och Södermanlands län med totalt 8 observerade individer på 13 lokaler. Violett guldvinge inventerades på 31 lokaler i Jämtland, Västernorrland och Västerbotten där totalt 26 individer inräknades. Under 2016 har också inventeringar av dårgräsfjäril genomförts på 10 lokaler fördelade i Östergötland och på Gotland. Totalt observerades 1407 individer varav 922 sågs på Gotland och resterande 485 i Östergötland.
|
|
| 15. |
- Pettersson, Lars B., et al.
(författare)
-
Svensk Dagfjärilsövervakning, årsrapport för 2017
- 2019
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Detta är den åttonde årsrapporten från Svensk Dagfjärilsövervakning, ett nationellt miljö-övervakningsprogram som koordineras av Lunds universitet på uppdrag av Naturvårdsverket sedan 2010. Svensk Dagfjärilsövervakning är ett samarbete mellan Sveriges Entomologiska Förening, Naturvårdsverket, Lunds universitet, Sveriges lantbruksuniversitet och Länsstyrelserna. Verksamheten möjliggörs av frivilliga landet runt som mellan den 1 april och 30 september räknar fjärilar. Räkningen sker med en gemensam, systematisk metodik och fördelas på 3-7 inventeringstillfällen under säsongen. Det finns två olika sätt att övervaka, dels punktlokaler som är områden med 25 m radie som bevakas i 15 min per besök, dels slingor som är 0,5-3 km långa rutter som man inventerar i lugn promenadtakt. Genom att övervakningen upprepas inom säsongen och över flera år är det möjligt att skatta hur fjärilsfaunan förändras i antal och artsammansättning. Det åttonde årets övervakning har resulterat i rapporter från 192 slingor och 286 punktlokaler. Slingorna och punkterna är spridda över hela landet, från Beddingestrand i söder till Vuollerim i norr. Antalet rapportörer under 2017 har varit 283 och Svensk Dagfjärilsövervakning har räknat in 64 322 fjärilar av 93 arter. I medeltal har det setts 10,7 arter per punktlokal och 16,1 arter per slinga. För varje funnen fjärilsart redovisar rapporten 2017 års observationer som ett totalantal, en utbredningskarta och figur över de veckor då arten påträffats. Talrikaste arterna 2017 var i tur och ordning luktgräsfjäril, citronfjäril och slåttergräsfjäril. Trender i antal mellan 2010 och 2017 har skattats med hjälp av analysverktyget TRIM för 86 dagfjärils- och bastardsvärmararter. Av dessa minskade 19 arter jämfört med 2010, 15 arter ökade, 8 arter var stabila, medan övriga arter varierade så pass mycket att trenderna är osäkra. Sammanvägda index, så kallade miljöindikatorer har räknats fram för 1) de tolv arter som ingår i den europeiska miljöindikatorn för gräsmarksfjärilar, 2) de tjugo vanligaste fjärilsarterna, 3) fjärilar i jordbruksmiljöer, samt 4) fjärilar i skogsmarker. Miljöindikatorerna för gräsmarksfjärilar och skogsfjärilar är stabila under perioden 2010-2017. Trenderna för miljöindikatorerna för de 20 vanligaste dagfjärilarna och fjärilar i jordbruksmiljöer är att dessa grupper minskar måttligt men signifikant under perioden.
|
|
| 16. |
- Pettersson, Lina M E, et al.
(författare)
-
Altered behavioural responses and functional recovery in rats following sciatic nerve compression and early vs late decompression
- 2016
-
Ingår i: Journal of Plastic Surgery and Hand Surgery. - 2000-656X. ; 50:6, s. 321-330
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: The aim of the study was to examine sensory behaviour and functional recovery in rats during nerve compression and after decompression. Compression injury is a far more common condition than nerve transection. The condition is characterised by numbness and a tingling/burning sensation, and some patients experience pain and allodynia during compression or after decompression treatment. The aetiology is in many cases unknown. Thus, further studies are of great importance for the understanding of this condition. Methods: In the present study, behavioural responses to tactile stimulation, thermal pain, as well as functional sensorimotor behaviour were investigated in rats before, during severe compression, and after decompression. The sciatic nerve of the rats was experimentally compressed for 3 or 28 days, whereafter surgical release, i.e. decompression, of the nerve was performed and the rats were examined up to ∼9 weeks. Results: An altered behaviour was found in response to compression injury, which is mitigated after early decompression treatment. Conclusions: These findings indicate that early intervention during severe compression injuries is of great importance for recovery and restoration of nerve function and, thus, should have an impact on clinical routines regarding treatment of compression injuries.
|
|
| 17. |
- Pogorelov, V., et al.
(författare)
-
From clusters to condensed phase - FT IR studies of water
- 2017
-
Ingår i: Journal of Molecular Liquids. - : Elsevier BV. - 0167-7322 .- 1873-3166. ; 235, s. 7-10
-
Tidskriftsartikel (refereegranskat)abstract
- Intermolecular hydrogen bonding, which is formed between water molecules in the condensed state, causes a variety of unique properties of liquid water. In this paper the results of experimental FT IR studies of water trapped in an Ar matrix as well as condensed water at temperatures from 133 to 293 K are presented. It is shown that the temperature evolution of the FTIR-spectra of water trapped in low-temperature matrices can be considered as an experimental model of the structure transformation of water during the phase transition from gas phase to condensed confined water. The comparison of the vibrational spectra of water in matrix isolation with the corresponding spectra of condensed water gives information about the peculiarities of H-bonded structures of water.
|
|
| 18. |
- Schlesinger, Daniel, et al.
(författare)
-
The temperature dependence of intermediate range oxygen-oxygen correlations in liquid water
- 2016
-
Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 145:8
-
Tidskriftsartikel (refereegranskat)abstract
- We analyze the recent temperature dependent oxygen-oxygen pair-distribution functions from experimental high-precision x-ray diffraction data of bulk water by Skinner et al. [J. Chem. Phys. 141, 214507 (2014)] with particular focus on the intermediate range where small, but significant, correlations are found out to 17 angstrom. The second peak in the pair-distribution function at 4.5 angstrom is connected to tetrahedral coordination and was shown by Skinner et al. to change behavior with temperature below the temperature of minimum isothermal compressibility. Here we show that this is associated also with a peak growing at 11 angstrom which strongly indicates a collective character of fluctuations leading to the enhanced compressibility at lower temperatures. We note that the peak at similar to 13.2 angstrom exhibits a temperature dependence similar to that of the density with a maximum close to 277 K or 4 degrees C. We analyze simulations of the TIP4P/2005 water model in the same manner and find excellent agreement between simulations and experiment albeit with a temperature shift of similar to 20 K.
|
|
| 19. |
- Styles, David, et al.
(författare)
-
Climate regulation, energy provisioning and water purification : Quantifying ecosystem service delivery of bioenergy willow grown on riparian buffer zones using life cycle assessment
- 2016
-
Ingår i: Ambio: a Journal of the Human Environment. - Cham : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 45:8, s. 872-884
-
Tidskriftsartikel (refereegranskat)abstract
- Whilst life cycle assessment (LCA) boundaries are expanded to account for negative indirect consequences of bioenergy such as indirect land use change (ILUC), ecosystem services such as water purification sometimes delivered by perennial bioenergy crops are typically neglected in LCA studies. Consequential LCA was applied to evaluate the significance of nutrient interception and retention on the environmental balance of unfertilised energy willow planted on 50-m riparian buffer strips and drainage filtration zones in the Skåne region of Sweden. Excluding possible ILUC effects and considering oil heat substitution, strategically planted filter willow can achieve net global warming potential (GWP) and eutrophication potential (EP) savings of up to 11.9 Mg CO2e and 47 kg PO4e ha−1 year−1, respectively, compared with a GWP saving of 14.8 Mg CO2e ha−1 year−1 and an EP increase of 7 kg PO4e ha−1 year−1 for fertilised willow. Planting willow on appropriate buffer and filter zones throughout Skåne could avoid 626 Mg year−1 PO4e nutrient loading to waters.
|
|
