Sperm whales (Physeter macrocephalus) are sexually dimorphic in several respects, including size, latitudinal distribution, and social structure. Females are known to have complex social structures, including long-term bonds, but the social structures of sexually mature or maturing males have received much less attention. Using data from aggregations of males off Norway, Nova Scotia, New Zealand, and the Galápagos Islands, we examined aggregation size, residence times within aggregations, clustering at the surface, and long-term bonds. Results were generally consistent among study areas. The aggregations found in each area contained around 10-30 males at any time, and were usually a few tens of kilometres across. Mean residence times within aggregations ranged from a few days to a few weeks. Close clustering at the surface was rare, but present at each site. There was no evidence for preferred companionship between individuals at any temporal scale in any of the study areas. The rarity of clustering and the apparent lack of long-term relationships amongst male sperm whales contrast strongly with results of studies on females, suggesting that both close spatial proximity at the surface and permanent bonds between individuals may be a consequence of the need for care of the young.Résumé : Les cachalots (Physeter macrocephalus) présentent un important dimorphisme sexuel, notamment en taille, en distribution latitudinale et en organisation sociale. Les femelles ont une organisation sociale très complexe qui inclut des associations à long terme entre individus, alors que l'organisation sociale des mâles adultes, ou subadultes, reste encore largement inconnue. En utilisant des données provenant de regroupements de mâles au large de la Norvège, de la Nouvelle Écosse, de la Nouvelle Zélande et des Îles Galápagos, nous avons examiné la taille des regroupements, la durée du séjour à l'intérieur de ces regroupement, la manière dont les individus se rassemblent à la surface et les associations à long terme entre individus. Les résultats étaient cohérants d'une région à l'autre. En général, les regroupements avaient quelques dizaines de kilomètres de diamètre et contennaient environ 10-30 mâles. La durée moyenne du séjour à l'intérieur de chacun de ces regroupements allait de quelques jours à quelques semaines. Les individus formaient rarement des groupes compacts de deux ou plusieurs individus séparés par moins de 100 m, mais de tels groupes ont été observés en surface dans chaque région. Rien dans nos données, dans aucune région, ni à aucune des échelles temporelles étudiées, ne laissait croire que certains individus puissent s'associer plus souvent avec tel mâle qu'avec tel autre. Le fait que les individus se regroupaient rarement à la surface et l'absence d'associations à long terme entre mâles présentent un contraste remarquable avec les résultats obtenus chez les femelles. Cela suggère que la proximité spatiale à la surface ainsi que les associations permanentes entre individus servent principalement à assure...
Male sperm whales are the basis for a commercially important whale‐watching industry at Kaikoura, New Zealand. We examined the influence of whale‐watching boats and aircraft over three years using observations from an independent research boat and from shore. We employed an information‐theoretic approach to determine which factors were necessary to explain variation in blow interval, time at surface, and time to first click. In almost all analyses, models required the inclusion of the presence of the research boat or whale‐watching boats or airplanes. The only exception was the model explaining variation in blow intervals observed from shore, which required only season. We also analyzed spatial behavior at the surface. Resident whales changed direction significantly more in the presence of whale‐watching boats compared to encounters with only the research boat present. No such difference was observed for encounters with aircraft. Our results thus indicate that sperm whales off Kaikoura respond to whale‐watching activities, although these changes are small and most likely not of biological importance. However, resident whales responded less to these activities compared to transient whales, possibly indicating habituation and, more importantly, the need to monitor continued activities closely.
Novel CO 2 heat pump systems for domestic hot water supply are modelled using an object-oriented thermodynamic model library written in Modelica. Due to the variety of mathematical structures of thermodynamic models and the possibilities of objectoriented modelling languages, powerful libraries are often very complex and hard to understand. The scope of the presented library lies on good readability and usability for both users and model designers. The basic structure and design concepts of the library are outlined and also the most important model concepts are explained. The heat pump system is modelled and simulation results are compared with test stand measurements. Simulation results are used to analyse the design of the system and to get information about possible further improvements. IntroductionCompression heat pump systems have the potential to decrease the primary energy consumption of domestic heating and hot water supply. Different studies [1] have shown that heat pump systems using the natural, environmentally friendly refrigerant CO 2 are able to achieve higher efficiencies than systems using conventional refrigerants when warming up heating water or potable hot water at a high temperature level (55-60 C). Thereby, new concepts of heat supply systems for low-energy buildings have resulted. Low-energy buildings are characterized by a high level of heat insulation, which leads to a reduced energy demand for heating water. However, the amount of heat required to warm up potable hot water rises compared with the overall energy demand of the building. The heating system as a whole has to supply less heat, but considered relatively, it has to deliver heat more frequently at higher temperature demands. To come close to the theoretical maximal efficiency in real systems, an accurate design is mandatory. To really lower the primary energy consumption, it is important to not only look at certain operating points but on the overall performance over long-term periods. For both aspects, simulation of heat pump systems is very useful and can support the design of heat pump systems significantly. Due to high variability of different concepts, a library with ready-to-use component models is a great advantage.There have been many research activities about simulation of thermodynamic systems during the last decades. A variety of different programming and modelling languages are used. Richter [2] gives an overview of what is state of the art in this area. The latest activities
Online learning is defined as the use of technology to either wholly or partially provide instruction and mechanisms for students to meet and collaborate (Moore et al., 2011). With recent advances in technology, adoption of online learning has expanded significantly in re-
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