262,785 research outputs found
Köl och roder
No full textDesign av köl och roder: Vad kan vi lära av flygplanskonstruktörer? Hur kan ett plan flyga? Vad är en elliptisk kraftfördelning? Varför är en djup och smal köl bättre än en grund och bred? Hur ser det optimala rodret ut? Hur stor betydelse har kölbulben på en modern segelbåt? Frågorna är många. Lars Larsson, Professor i Hydrodynamik vid Chalmers, har svaren
Köl och roder
No full textDesign av köl och roder: Vad kan vi lära av flygplanskonstruktörer? Hur kan ett plan flyga? Vad är en elliptisk kraftfördelning? Varför är en djup och smal köl bättre än en grund och bred? Hur ser det optimala rodret ut? Hur stor betydelse har kölbulben på en modern segelbåt? Frågorna är många. Lars Larsson, Professor i Hydrodynamik vid Chalmers, har svaren
Comparing soil organic carbon stocks in contrasting Mediterranean pedosystems: How physical-chemical properties and land uses influence its behavior
No full textSoils play a pivotal role in the global carbon cycle processes and behavior, with soil organic carbon stocks (SOCs) representing the largest terrestrial carbon (C) pool. Soil C sequestration enhanced soil quality and the overall ecosystem goods and services, together with socio-economic benefits. The Mediterranean areas are one of the world’s biodiversity hotspots for conservation priorities. The Sardinia Island (south Italy) hosts peculiar eco- and pedosystems thanks to its peculiar climatic, geological, geomorphological, and ancient land use history featured for one of the oldest civilizations (Nuragic, 6,000 BC). All factors are brought together in extremely peculiar soil conditions. This study aimed to investigate SOCs and related behavior in two contrasting Mediterranean pedosystems in Sardinia (Cambisols developed on granite vs Luvisols on limestone), featuring different land covers, by comparing: i) surface vs deep soil horizons (A vs B); ii) different land covers inside and between the two investigated pedosystems. Several properties were assessed, including vegetation (vascular plants), litter (C, N, C/N, litter carbon stocks, P, Ca, Mg, Na, K, Cu, Fe, Mn, and Zn), and soil physical- (sand, silt, and clay contents, bulk density) chemical features (pH, electrical conductivity, soil organic matter, total N, total P, available P, C/N, exchangeable H+Al, exchangeable cations, cation-exchange capacity, base saturation, Cu, Fe, Mn, and Zn), wherever feasible. Statistical analyses were performed to determine: i) significant differences (p < 0.05) between and among investigated horizons and land uses; ii) bivariate correlation between investigated parameters (Pearson’s Correlation Matrix (CM)); variability and complex multiple relationships among investigated parameters through factor analysis (FA), while a principal component analysis (PCA) was conducted to identify the soil physical-chemical parameters having greater importance in terms of observed variability within (a) the investigated pedosystem, as well as (b) among the different land covers. Results revealed that areas with natural or close-to-natural features exhibited significantly higher SOCs amounts compared to more intense and human-influenced land covers. Furthermore, the differences in substrate and following soil formation processes between the two investigated pedosystems led to different SOCs behaviors, demonstrating a strong relation between SOCs and intrinsic soil features. This emphasizes the greater importance of soil nature in influencing SOCs, greater compared to that shown by land cover variations. Consequently, this study blatantly demonstrates that SOCs investigations, if not carried out through an in-depth soil investigation, may lead to inaccurate, or even wrong, outcomes and following considerations.Soils play a pivotal role in the global carbon cycle processes and behavior, with soil organic carbon stocks (SOCs) representing the largest terrestrial carbon (C) pool. Soil C sequestration enhanced soil quality and the overall ecosystem goods and services, together with socio-economic benefits. The Mediterranean areas are one of the world’s biodiversity hotspots for conservation priorities. The Sardinia Island (south Italy) hosts peculiar eco- and pedosystems thanks to its peculiar climatic, geological, geomorphological, and ancient land use history featured for one of the oldest civilizations (Nuragic, 6,000 BC). All factors are brought together in extremely peculiar soil conditions. This study aimed to investigate SOCs and related behavior in two contrasting Mediterranean pedosystems in Sardinia (Cambisols developed on granite vs Luvisols on limestone), featuring different land covers, by comparing: i) surface vs deep soil horizons (A vs B); ii) different land covers inside and between the two investigated pedosystems. Several properties were assessed, including vegetation (vascular plants), litter (C, N, C/N, litter carbon stocks, P, Ca, Mg, Na, K, Cu, Fe, Mn, and Zn), and soil physical- (sand, silt, and clay contents, bulk density) chemical features (pH, electrical conductivity, soil organic matter, total N, total P, available P, C/N, exchangeable H+Al, exchangeable cations, cation-exchange capacity, base saturation, Cu, Fe, Mn, and Zn), wherever feasible. Statistical analyses were performed to determine: i) significant differences (p < 0.05) between and among investigated horizons and land uses; ii) bivariate correlation between investigated parameters (Pearson’s Correlation Matrix (CM)); variability and complex multiple relationships among investigated parameters through factor analysis (FA), while a principal component analysis (PCA) was conducted to identify the soil physical-chemical parameters having greater importance in terms of observed variability within (a) the investigated pedosystem, as well as (b) among the different land covers. Results revealed that areas with natural or close-to-natural features exhibited significantly higher SOCs amounts compared to more intense and human-influenced land covers. Furthermore, the differences in substrate and following soil formation processes between the two investigated pedosystems led to different SOCs behaviors, demonstrating a strong relation between SOCs and intrinsic soil features. This emphasizes the greater importance of soil nature in influencing SOCs, greater compared to that shown by land cover variations. Consequently, this study blatantly demonstrates that SOCs investigations, if not carried out through an in-depth soil investigation, may lead to inaccurate, or even wrong, outcomes and following considerations
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Finansministeriet er i splid med sig selv
No full textFinansministeriet roder i egne logikker i debatten om store bededag
Protecting Animals 36: Author Witi Ihimaera
No full textIn this very special episode of Knowing Animals I am joined by beloved New Zealand author Witi Ihimaera. Witi has written many books featuring nonhuman animals. He offers us a non-colonial lens through which to think about the human/nonhuman relationship
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
Author in Essay by I. A. Goncharov “Pepiniere”
No full textFeatures of the embodiment of the author’s position in the essay by I. A. Goncharov “Pepiniere” are considered. The relevance of the study is due to the poorly studied poetics of this work. A review of the scientific literature on relevant topics is performed. Methodological and theoretical definitions are given. The scientific novelty of the article is in the fact that for the first time attention is paid to artistic techniques that allow to identify the author's position in the specified literary text. The author of the article grounds her opinion from the fact that, despite the dominance of the subjective point of view, other characters’ views stand out in the work. It is concluded in the study that the text of the work represents a biographical author and author-creator. It was established that the position of the author-creator is expressed through the title, epigraphs, which are quotes, as well as through different points of view, including the author-character, the author-narrator, the characters of the work. The author of the article dwells in detail on different ways of expressing the points of view of the author-character and the author-narrator. It is proved that the point of view of the author-character and the author-narrator can intersect, they are interchanged. The author's development of the term comic “point of view” is presented in the article
Noggrannheten hos tidsberoende kontra stationära krafter på ett roder i en propellerström
No full textIn computational fluid dynamics (CFD), a transient simulation is in general more costly than computing the steady state of the system, if such a state exists. The velocity field produced by the propeller blades upstream of a rudder is transient in nature, and rudder design using CFD may therefore become very time-consuming. If a steady solution could accurately predict the performance of the rudder, such an approach would be favourable. The aim of the present study was to assess the possibility to accurately predict the performance of a rudder operating in a propeller slipstream using steady state simulations, e.g. an actuator disk model (ADM). For this reason, the performance of the two-dimensional NACA 0021 rudder section submitted to a sinusoidal transverse gust, representing a transient propeller slipstream, was simulated using ANSYS Fluent. The predicted force coefficients are presented for a number of gust amplitudes, mean angles of attack and reduced frequencies of the transverse gust. The simulations have shown that the modelling error introduced when predicting the performance in a steady state is highly dependent on all these parameters of the actual transient flow, and that the steady result may be a severe over- or under-prediction of the real performance of the rudder. Heavily loaded propellers are suspected to be less suitable for ADM modelling in rudder performance prediction. The predicted unsteady lift coefficient was compared to the linear theories of Horlock and Sears, and the agreement was fair at zero mean angle of attack but poor at a mean angle of attack of 10°. It was also found that the predicted performance of the rudder was significantly altered when the chord based Reynolds number was increased by a factor of 10, which has implications on the validity of model-scale simulations. The effect of including turbulent transition modelling for some of the simulations was also investigated, and the discrepancy in predicted performance was found to be considerable. Due to the formation of a laminar separation bubble the predicted trailing edge separation and viscous stress on the rudder were significantly decreased, leading to better overall performance.Tidsberoende simuleringar inom strömningslära är betydligt mer beräkningsintensiva än stationära simuleringar av samma system, såvida en stationär lösning finns. Strömningsfältet från en propeller framför ett roder är tidsberoende, vilket därför kan göra roderdesign med hjälp av flödessimuleringar (CFD) väldigt tidskrävande. Om rodrets prestanda går att prediktera med en stationär lösning vore detta fördelaktigt. Målet med denna studie var att utvärdera möjligheten att noggrant prediktera prestandan hos ett roder i en propellerström med stationära simuleringar, t.ex. en aktuatordiskmodell (ADM). Till detta syfte har prestandan hos en tvådimensionell NACA 0021-profil simulerats, då rodret utsattes för ett sinusformad våg i inflödet, vilket skulle representera en tidsberoende propellerström. De beräknade kraftkoefficienterna har utvärderats mot det vågformade inflödets amplitud, frekvens och genomsnittliga anfallsvinkel. Simuleringarna har visat att felet som introduceras när prestandan predikteras stationärt beror kraftigt på värdet av alla dessa parametrar i den verkliga tidsberoende propellerströmmen, och den stationära lösningen kan antingen vara en över- eller underskattning av den verkliga prestandan. Tungt lastade propellrar misstänks vara minst lämpade för modellering med en ADM för roderberäkningar. Den predikterade roderprestandan förändrades avsevärt då Reynoldstalet ökades med en tiopotens, vilket har betydelse för giltigheten av simuleringar på modellskala. Resultaten har även jämförts med Horlocks och Sears analytiska teorier, och överensstämmelsen var godtagbar vid en genomsnittlig anfallsvinkel på 0° men dålig vid 10°. Effekten av att inkludera transitionsmodellering har undersökts för några av simuleringarna och skillnaden i resultat var avsevärd. Både separationen vid rodrets aktre ände och den viskösa skjuvkraften på rodret reducerades på grund av att transitionsmodellen predikterade en laminär separtationsbubbla
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