| 1. |
- Georgsson, Fredrik, et al.
(författare)
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Development of an Autonomous Path Tracking Forest Machine : a status report
- 2005
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In many respects traditional automation in the forest-machine industry has reached an up- per limit, since the driver already has to deal with an excess of information and take too many decisions at a very high pace. To further automation still, introduction of semi-autonomous and autonomous functions are expected and considered necessary. This paper describes an ongoing project along these ideas. We describe the development of the hardware and software of an unmanned shuttle that shifts timber from the area of felling to the main roads for fur- ther transportation. A new path-tracking algorithm is introduced, and demonstrated as being superior to standard techniques, such as Follow-the-Carrot and Pure-Pursuit. To facilitate the research and development, a comprehensive software architecture for sensor and actuator interfacing is developed. Obstacle avoidance is accomplished by a new kind of radar, developed for and by the automotive industry. Localization is accomplished by a Kalman filter combining data from a Real-Time Kinematic Differential GPS/GLONASS and a gyro/compass. Tests conducted on a simulator and a small-scale robot show promising results. Tests on the real forest machine are ongoing, and will be completed before the end of 2005.
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| 2. |
- Gaillard, Marie-José, et al.
(författare)
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Causes of Regional Change : Land Cover
- 2015
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Ingår i: Second Assessment of Climate Change for the Baltic Sea Basin. - Cham : Springer. - 9783319160054 - 9783319160061 ; , s. 453-477
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Bokkapitel (refereegranskat)abstract
- Anthropogenic land-cover change (ALCC) is one of the few climate forcings for which the net direction of the climate response over the last two centuries is still not known. The uncertainty is due to the often counteracting temperature responses to the many biogeophysical effects and to the biogeochemical versus biogeophysical effects. Palaeoecological studies show that the major transformation of the landscape by anthropogenic activities in the southern zone of the Baltic Sea basin occurred between 6000 and 3000/2500 cal year BP. The only modelling study of the biogeophysical effects of past ALCCs on regional climate in north-western Europe suggests that deforestation between 6000 and 200 cal year BP may have caused significant change in winter and summer temperature. There is no indication that deforestation in the Baltic Sea area since AD 1850 would have been a major cause of the recent climate warming in the region through a positive biogeochemical feedback. Several model studies suggest that boreal reforestation might not be an effective climate warming mitigation tool as it might lead to increased warming through biogeophysical processes.
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| 3. |
- Ahlbeck Bergendahl, Ida, et al.
(författare)
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Fisk- och skaldjursbestånd i hav och sötvatten 2016 : Resursöversikt
- 2016
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I rapporten kan du ta del av bedömningen som görs av situationen för bestånd som regleras inom ramen för EU:s gemensamma fiskeripolitik (GFP). Bedömningarna baseras på det forskningssamarbete och den rådgivning som sker inom det Internationella Havsforskningsrådet (ICES).De bestånd som förvaltas nationellt baseras på de biologiska underlagen, och rådgivningen i huvudsak på den forskning och övervakning samt analys som bedrivs av Institutionen för akvatiska resurser vid Sveriges lantbruksuniversitet (SLU Aqua) samt yrkesfiskets rapportering.Rapporten omfattar 41 fiskarter uppdelade i olika bestånd, samt sju skal- och blötdjursarter.Nytt för årets upplaga är kapitlet om ekosystemtjänster. Avsnittet beskriver de fördelar människan får genom ekosystemen, till exempel hur fisk och skaldjur kommer till nytta för människan genom föda, rekreation och biologisk mångfald. Nytt för i år är också att rapportens diagram och figurer anpassats för läsare med defekt färgseende.Översikten är utarbetad av SLU Aqua på uppdrag av Havs- och vattenmyndigheten.
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| 4. |
- Andersson, Magnus, et al.
(författare)
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Fiskbestånd och miljö i hav och sötvatten : Resurs- och miljööversikt 2012
- 2012
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Detta är den nionde utgåvan av den samlade översikten över fisk- och kräftdjursbeståndens status i våra vatten. Kunskap om fiskbestånden och miljön är en förutsättning för att utnyttjandet av fiskresurserna skall bli bärkraftigt. För svenska vattenområden beskrivs miljöutvecklingen i ett ekosystemsperspektiv, dels för att tydliggöra fiskens ekologiska roll och beskriva yttre miljöfaktorer som påverkar fiskbestånden, dels för att belysa fiskets effekter på miljön.Fiskbestånd och miljö i hav och sötvatten är utarbetad av Sveriges lantbruksuniversitet (SLU), Institutionen för akvatiska resurser (SLU Aqua), på uppdrag av Havs- och vattenmyndigheten. Rapporten sammanfattar utveckling och beståndsstatus för de kommersiellt viktigaste fisk- och kräftdjursarterna i våra vatten. Bedömningar och förvaltningsråd är baserade på Internationella Havsforskningsrådets (ICES) rådgivning, SLU Aquas nationella och regionala provfiskedata, samt yrkesfiskets rapportering.
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| 5. |
- Kwong, Wai Ling, et al.
(författare)
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Cationic Vacancy Defects in Iron Phosphide : A Promising Route toward Efficient and Stable Hydrogen Evolution by Electrochemical Water Splitting
- 2017
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Ingår i: ChemSusChem. - : Wiley-Blackwell. - 1864-5631 .- 1864-564X. ; 10:22, s. 4544-4551
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Tidskriftsartikel (refereegranskat)abstract
- Engineering the electronic properties of transition metal phosphides has shown great effectiveness in improving their intrinsic catalytic activity for the hydrogen evolution reaction (HER) in water splitting applications. Herein, we report for the first time, the creation of Fe vacancies as an approach to modulate the electronic structure of iron phosphide (FeP). The Fe vacancies were produced by chemical leaching of Mg that was introduced into FeP as "sacrificial dopant". The obtained Fe-vacancy-rich FeP nanoparticulate films, which were deposited on Ti foil, show excellent HER activity compared to pristine FeP and Mg-doped FeP, achieving a current density of 10 mAcm(-2) at overpotentials of 108 mV in 1 m KOH and 65 mV in 0.5 m H2SO4, with a near-100% Faradaic efficiency. Our theoretical and experimental analyses reveal that the improved HER activity originates from the presence of Fe vacancies, which lead to a synergistic modulation of the structural and electronic properties that result in a near-optimal hydrogen adsorption free energy and enhanced proton trapping. The success in catalytic improvement through the introduction of cationic vacancy defects has not only demonstrated the potential of Fe-vacancy-rich FeP as highly efficient, earth abundant HER catalyst, but also opens up an exciting pathway for activating other promising catalysts for electrochemical water splitting.
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| 6. |
- Rissler, Jenny, et al.
(författare)
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Experimental determination of deposition of diesel exhaust particles in the human respiratory tract
- 2012
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Ingår i: Journal of Aerosol Science. - : Elsevier BV. - 0021-8502 .- 1879-1964. ; 48, s. 18-33
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Tidskriftsartikel (refereegranskat)abstract
- Diesel emissions are a major contributor to combustion-generated airborne ambient particles. To understand the role of diesel particulate emissions on health effects, it is important to predict the actual particulate dose deposited in the human respiratory tract, with respect to number, surface area and mass. This is complicated by the agglomerate nature of some of these particles. In this study the respiratory tract deposition fraction in the size range 10-500 nm, was determined for 10 healthy volunteers during both idling and transient engine running conditions of a heavy duty diesel engine. The aerosol was characterized with respect to both chemical and physical properties including size resolved particle effective density. The dominating part of the emitted particles had an agglomerate structure. For those formed during transient running conditions, the relationship between particle mass and mobility diameter could be described by a power law function. This was not the case during idling, most likely because of volatile compounds condensing on the agglomerates. The respiratory tract particle deposition revealed large intra-subject variability with some subjects receiving a dose that was twice as high as that of others, when exposed to the same particle concentration. Associations were found between total deposited fractions (TDF), and breathing pattern. There was a difference between the idling and transient cycle with TDF being higher with respect to number during idling. The measured size-dependent deposition fraction of the agglomerated exhaust particles from both running conditions was nearly identical and closely resembled that of spherical hydrophobic particles, if plotted as a function of mobility diameter. Thus, for the size range covered, the mobility diameter could well describe the diameter-dependent particle respiratory tract deposition probability, regardless of the agglomeration state of the particles. Whilst mobility diameter well describes the deposition fraction, more information about particle characteristics is needed to convert this to volume equivalent diameter or estimate dose with respect to surface area or mass. A methodology is presented and applied to calculate deposited dose by surface area and mass of agglomerated particles. The methodology may be useful in similar studies estimating dose to the lung, deposition onto cell cultures and in animal studies. (C) 2012 Elsevier Ltd. All rights reserved.
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| 7. |
- Sandström, Alfred, et al.
(författare)
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Has climate variability driven the trends and dynamics in recruitment of pelagic fish species in Swedish Lakes Vanern and Vattern in recent decades?
- 2014
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Ingår i: Aquatic Ecosystem Health and Management. - : Michigan State University Press. - 1463-4988 .- 1539-4077. ; 17, s. 349-356
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Tidskriftsartikel (refereegranskat)abstract
- We analyse trends and dynamics in time-series of recruitment in Smelt and Vendace in the Swedish large Lakes Vanern and Vattern, with particular emphasis on the importance of climate variability. Climate-related predictor variables in our analyses were air temperature, water temperature, ice coverage and duration of ice winters. The variation between years with successful recruitment and years with low recruitment was considerable in both species and especially for Vendace. Ultra-oligotrophic Lake Vattern was characterized by strong pulses in Vendace recruitment, occurring mainly in four year intervals. Smelt recruitment was positively related to recruitment pulses of Vendace. In meso-oligotrophic Lake Vanern, Vendace pursuit was more successful in years with long ice winters that lasted until the middle of March or longer. Smelt recruitment in Lake Vanern was positively correlated to the air temperature in April. There was no obvious synchrony in recruitment patterns between the two lakes. Recruitment of Smelt in Lake Vanern's two main basins was, however, positively correlated. The results indicated that climate factors may influence the recruitment of important pelagic species, but that the effects may differ between lakes, even though the systems are adjacent and situated at the same latitude.
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| 8. |
- Sandström, Robin, et al.
(författare)
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Compositional Evaluation of Coreduced Fe-Pt Metal Acetylacetonates as PEM Fuel Cell Cathode Catalyst
- 2018
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Ingår i: ACS Applied Energy Materials. - : American Chemical Society (ACS). - 2574-0962. ; 1:12, s. 7106-7115
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Tidskriftsartikel (refereegranskat)abstract
- Platinum iron nanoparticles were produced by solvothermal coreduction of organic Fe and Pt precursor compounds and supported on conventional Vulcan XC 72. Evaluation of oxygen reduction performance reveals a highly active surface with up to 5 times the specific activity of commercial Pt Vulcan measured in O-2-saturated 0.1 M HClO4. A particle size of 5.5 nm for the best performing sample, produced from an initial metal ratio of 1:1, provided 28% higher mass activity than the commercial reference. Membrane electrode assemblies, optimized for both H-2/O-2 and direct formic acid fuel cells, were produced, and the PEM fuel cell cathodic performance displayed results with similar enhancements as its ex situ measured mass activity, although a delamination of the catalyst layer from the membrane could be observed even when employing a hot-pressing procedure during MEA fabrication. Physical characterizations including X-ray photoelectron spectroscopy and in situ X-ray diffraction reveal oxidized states of Fe incorporated into the disordered face-centered cubic Pt nanoparticles, supported by composition-dependent morphological changes as observed by transmission electron microscopy. The provided insight into fuel cell performance as well as CO-oxidation attributes are expected to assist in selecting suitable applications and operating conditions for such FePt type nanoparticles.
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| 9. |
- Faragardi, Hamid Reza, et al.
(författare)
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A communication-aware solution framework for mapping AUTOSAR runnables on multi-core systems
- 2014
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Ingår i: 19th IEEE International Conference on Emerging Technologies and Factory Automation, ETFA 2014. - 9781479948468 ; , s. Article number 7005244-
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Konferensbidrag (refereegranskat)abstract
- An AUTOSAR-based software application contains a set of software components, each of which encapsulates a set of runnable entities. In fact, the mission of the system is fulfilled as result of the collaboration between the runnables. Several trends have recently emerged to utilize multi-core technology to run AUTOSAR-based software. Not only the overhead of communication between the runnables is one of the major performance bottlenecks in multi-core processors but it is also the main source of unpredictability in the system. Appropriate mapping of the runnables onto a set of tasks (called mapping process) along with proper allocation of the tasks to processing cores (called task allocation process) can significantly reduce the communication overhead. In this paper, three solutions are suggested, each of which comprises both the mapping and the allocation processes. The goal is to maximize key performance aspects by reducing the overall inter-runnable communication time besides satisfying given timing and precedence constraints. A large number of randomly generated experiments are carried out to demonstrate the efficiency of the proposed solutions.
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| 10. |
- Fritioff, Karin, et al.
(författare)
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Observation of an excited C2-4 ion
- 2004
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Ingår i: Journal of Physics B: Atomic, Molecular and Optical Physics. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 37:11, s. 2241-2246
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Tidskriftsartikel (refereegranskat)abstract
- This paper reports an experimental investigation of the electron impact detachment of C−4. We observe structure in the electron impact cross section for detaching a single electron from a C−4 cluster anion, which we attribute to the formation and decay of the C2−4 dianion. The system is energetically unstable and very rapidly decays via double autodetachment. The energy and width of the resonance were determined to be 8.8(5) eV and 1.4(5) eV, respectively, and the resonance lies 1.5(5) eV above the ground state of the neutral system. The experiment was conducted by merging monoenergetic electron and ion beams in the heavy ion storage ring CRYRING. The detachment channel was monitored by detecting neutral C4 fragments.
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