| 1. |
- Ahlgren, Fredrik, 1980-, et al.
(författare)
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Waste Heat Recovery in a Cruise Vessel in the Baltic Sea by Using an Organic Rankine Cycle : A Case Study
- 2015
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Ingår i: ASME Turbo Expo 2015: Turbine Technical Conference and Exposition. - : ASME Press. - 9780791856673 ; , s. 43392-43416
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Konferensbidrag (refereegranskat)abstract
- Maritime transportation is a significant contributor to SOx, NOx and particle matter emissions, even though it has a quite low CO2 impact. New regulations are being enforced in special areas that limit the amount of emissions from the ships. This fact, together with the high fuel prices, is driving the marine industry towards the improvement of the energy efficiency of current ship engines and the reduction of their energy demand. Although more sophisticated and complex engine designs can improve significantly the efficiency of the energy systems in ships, waste heat recovery arises as the most influent technique for the reduction of the energy consumption. In this sense, it is estimated that around 50% of the total energy from the fuel consumed in a ship is wasted and rejected in fluid and exhaust gas streams. The primary heat sources for waste heat recovery are the engine exhaust and the engine coolant. In this work, we present a study on the integration of an organic Rankine cycle (ORC) in an existing ship, for the recovery of the main and auxiliary engines exhaust heat. Experimental data from the operating conditions of the engines on the M/S Birka Stockholm cruise ship were logged during a port-to-port cruise from Stockholm to Mariehamn over a period of time close to one month. The ship has four main engines Wärtsilä 5850 kW for propulsion, and four auxiliary engines 2760 kW used for electrical consumers. A number of six load conditions were identified depending on the vessel speed. The speed range from 12–14 knots was considered as the design condition, as it was present during more than 34% of the time. In this study, the average values of the engines exhaust temperatures and mass flow rates, for each load case, were used as inputs for a model of an ORC. The main parameters of the ORC, including working fluid and turbine configuration, were optimized based on the criteria of maximum net power output and compactness of the installation components. Results from the study showed that an ORC with internal regeneration using benzene would yield the greatest average net power output over the operating time. For this situation, the power production of the ORC would represent about 22% of the total electricity consumption on board. These data confirmed the ORC as a feasible and promising technology for the reduction of fuel consumption and CO2 emissions of existing ships.
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| 2. |
- Alfalahi, Alyaa, et al.
(författare)
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Expanding a dictionary of marker words for uncertainty and negation using distributional semantics
- 2015
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Ingår i: EMNLP 2015 - 6th International Workshop on Health Text Mining and Information Analysis, LOUHI 2015 : Proceedings of the Workshop - Proceedings of the Workshop. - : Association for Computational Linguistics. - 9781941643327 ; , s. 90-96
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Konferensbidrag (refereegranskat)abstract
- Approaches to determining the factuality of diagnoses and findings in clinical text tend to rely on dictionaries of marker words for uncertainty and negation. Here, a method for semi-automatically expanding a dictionary of marker words using distributional semantics is presented and evaluated. It is shown that ranking candidates for inclusion according to their proximity to cluster centroids of semantically similar seed words is more successful than ranking them according to proximity to each individual seed word.
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| 3. |
- Ambrazaitis, Gilbert, 1979-, et al.
(författare)
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Focal F0 peak shape and sentence mode in Swedish
- 2015
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Ingår i: Proceedings of the 18th International Congress of Phonetic Sciences. - Glasgow : University of Glasgow. - 9780852619414 - 9780852619421
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Konferensbidrag (refereegranskat)abstract
- Shape characteristics of rising-falling accentual F0 peaks of Stockholm Swedish Accent I words in narrow focus are studied in a corpus of 287 read sentences. The corpus includes statements and three types of polar questions. Results reveal a clear effect of sentence mode on the shape of the accentual rises: Statements are predominantly characterized by convex rises, questions by concave rises.
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| 4. |
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| 5. |
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| 6. |
- Ambrazaitis, Gilbert, et al.
(författare)
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Multimodal levels of prominence : a preliminary analysis of head and eyebrow movements in Swedish news broadcasts
- 2015
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Ingår i: Proceedings from Fonetik 2015 : Lund, June 8-10, 2015. Working Papers 55. 2015. - Lund, June 8-10, 2015. Working Papers 55. 2015.. - Lund : Centre for Languages and Literature, Lund University. - 0280-526X. ; 55, s. 11-16, s. 11-16
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This paper presents a first analysis of the distribution of head and eyebrow movements as a function of (a) phonological prominence levels (focal, non-focal) and (b) word accent (Accent 1, Accent 2) in Swedish news broadcasts. Our corpus consists of 31 brief news readings, comprising speech from four speakers and 986 words in total. A head movement was annotated for 229 (23.2%) of the words, while eyebrow movements occurred much more sparsely (67 cases or 6.8%). Results of χ2-tests revealed a dependency of the distribution of movements on the one hand and focal accents on the other, while no systematic effect of the word accent type was found. However, there was an effect of the word accent type on the annotation of ‘double’ head movements. These occurred very sparsely, and predominantly in connection with focally accented compounds (Accent 2), which are characterized by two lexical stresses. Overall, our results suggests that head beats might have a closer association with phonological prosodic structure, while eyebrow movements might be more restricted to higher-level prominence and information-structure coding. Hence, head and eyebrow movements can represent two quite different modalities of prominence cuing, both from a formal and functional point of view, rather than just being cumulative prominence markers.
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| 7. |
- Amin, Vikesh, et al.
(författare)
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The intergenerational transmission of schooling : Are mothers really less important than fathers?
- 2015
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Ingår i: Economics of Education Review. - : Elsevier BV. - 0272-7757 .- 1873-7382. ; 47, s. 100-117
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Tidskriftsartikel (refereegranskat)abstract
- There is a "puzzle" in the literature on the intergenerational transmission of schooling, where twin studies emphasize the importance of fathers' schooling, whereas IV-studies often emphasize the importance of mothers. We provide new evidence on this "puzzle" using register based Swedish data on the largest sample of twins used so far in the literature. In contrast to previous twin studies, our results confirm the importance of mothers' schooling. We also provide the first twin-based evidence of possible role model effects, where our estimates suggest that mother's schooling matters more than father's schooling for daughters schooling. One additional year of mothers' schooling raises daughter's schooling by a tenth of a year, which is similar to some of the previous IV-based estimates in the literature. Finally, we bring in new US twin data that for the first time allows a replication of previous twin-based estimates of the intergenerational transmission of schooling in the US. The results show no statistically significant effect of mothers' and fathers' schooling on children's schooling. Our results have implications for assessing the efficiency of policies that subsidize the schooling of men and women and are in contrast to most previous findings in the twin literature. (C) 2015 Elsevier Ltd. All rights reserved.
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| 8. |
- Andersson, Ewa, et al.
(författare)
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Registered nurses’ descriptions of caring : A phenomenographic interview study
- 2015
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Ingår i: BMC Nursing. - : BioMed Central. - 1472-6955. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Nursing has come a long way since the days of Florence Nightingale and even though no consensus exists it would seem reasonable to assume that caring still remains the inner core, the essence of nursing. In the light of the societal, contextual and political changes that have taken place during the 21st century, it is important to explore whether these might have influenced the essence of nursing. The aim of this study was to describe registered nurses’ conceptions of caring. Methods: A qualitative design with a phenomenographic approach was used. The interviews with twenty-one nurses took place between March and May 2013 and the transcripts were analysed inspired by Marton and Booth’s description of phenomenography. Results: The analysis mirrored four qualitatively different ways of understanding caring from the nurses’ perspective: caring as person-centredness, caring as safeguarding the patient’s best interests, caring as nursing interventions and caring as contextually intertwined. Conclusion: The most comprehensive feature of the nurses’ collective understanding of caring was their recognition and acknowledgment of the person behind the patient, i.e. person-centredness. However, caring was described as being part of an intricate interplay in the care context, which has impacted on all the described conceptions of caring. Greater emphasis on the care context, i.e. the environment in which caring takes place, are warranted as this could mitigate the possibility that essential care is left unaddressed, thus contributing to better quality of care and safer patient care.
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| 9. |
- Andersson, Ewa, et al.
(författare)
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Registered nurses views of caring in coronary care - a deductive and inductive content analysis
- 2015
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Ingår i: Journal of Clinical Nursing. - : Wiley. - 0962-1067 .- 1365-2702. ; 24:23-24, s. 3481-3493
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Tidskriftsartikel (refereegranskat)abstract
- Aims and objectives. To extend nurses' descriptions of how they understood caring, as reflected in the findings of an earlier study (i.e. the hierarchical outcome space) and to gain additional understandings and perspectives of nurses' views of caring in relation to a coronary care patient case. Background. Scientific literature from the 1970s-1990s contains descriptions of caring in nursing. In contrast, the contemporary literature on this topic - particularly in the context of coronary care - is very sparse, and the few studies that do contain descriptions rarely do so from the perspective of nurses. Design. Qualitative descriptive study. Methods. Twenty-one nurses were interviewed using the stimulated recall interview technique. The data were analysed using deductive and inductive qualitative content analysis. Results. The results of the iterative and integrated content analysis showed that the data mainly reproduced the content of the hierarchical outcome space describing how nurses could understand caring; however, in the outcome space, the relationship broke up (i.e. flipped). The nurses' views of caring could now also be understood as: person-centredness 'lurking' in the shadows; limited 'potential' for safeguarding patients' best interests; counselling as virtually the 'only' nursing intervention; and caring preceded by the 'almighty' context. Their views offered alternative and, at times, contrasting perspectives of caring, thereby adding to our understanding of it. Conclusion. Caring was described as operating somewhere between the nurses caring values and the contextual conditions in which caring occurred. This challenged their ability to sustain caring in accordance with their values and the patients' preferences. Relevance to clinical practice. To ensure that the essentials of caring are met at all times, nurses need to plan and deliver caring in a systematic way. The use of systematic structures in caring, as the nursing process, can help nurses to work in a person-centred way, while sustaining their professional values.
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| 10. |
- Aurelius, Oskar, et al.
(författare)
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The Crystal Structure of Thermotoga maritima Class III Ribonucleotide Reductase Lacks a Radical Cysteine Pre-Positioned in the Active Site
- 2015
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10:7
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Tidskriftsartikel (refereegranskat)abstract
- Ribonucleotide reductases (RNRs) catalyze the reduction of ribonucleotides to deoxyribonucleotides, the building blocks for DNA synthesis, and are found in all but a few organisms. RNRs use radical chemistry to catalyze the reduction reaction. Despite RNR having evolved several mechanisms for generation of different kinds of essential radicals across a large evolutionary time frame, this initial radical is normally always channelled to a strictly conserved cysteine residue directly adjacent to the substrate for initiation of substrate reduction, and this cysteine has been found in the structures of all RNRs solved to date. We present the crystal structure of an anaerobic RNR from the extreme thermophile Thermotoga maritima (tmNrdD), alone and in several complexes, including with the allosteric effector dATP and its cognate substrate CTP. In the crystal structure of the enzyme as purified, tmNrdD lacks a cysteine for radical transfer to the substrate pre-positioned in the active site. Nevertheless activity assays using anaerobic cell extracts from T. maritima demonstrate that the class III RNR is enzymatically active. Other genetic and microbiological evidence is summarized indicating that the enzyme is important for T. maritima. Mutation of either of two cysteine residues in a disordered loop far from the active site results in inactive enzyme. We discuss the possible mechanisms for radical initiation of substrate reduction given the collected evidence from the crystal structure, our activity assays and other published work. Taken together, the results suggest either that initiation of substrate reduction may involve unprecedented conformational changes in the enzyme to bring one of these cysteine residues to the expected position, or that alternative routes for initiation of the RNR reduction reaction may exist. Finally, we present a phylogenetic analysis showing that the structure of tmNrdD is representative of a new RNR subclass IIIh, present in all Thermotoga species plus a wider group of bacteria from the distantly related phyla Firmicutes, Bacteroidetes and Proteobacteria.
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