65,842 research outputs found

    From Comparison to Collaboration: Experiments with a New Scholarly and Political Form

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    Society and the workplace are two factors that are important for the individual's health status. It is important that the individuals has the right skills to take care of their health. For organizations, it is important to strive for the welfare of their employees. This has proven to have a positive impact on work performance, reduced absenteeism and reduced costs for rehabilitation. In 2007, the local authorities in Umeå implemented a wellness offering for all employees working in the municipality administration. They later saw a need to assist employees who needed help getting started with new exercise habits. This study aims to examine how the participants in the "Get Started Programme", succeeded in creating lasting exercise habits , 3-4 years after completing the program. Research questions are: How have the participants increased their knowledge practically and theoretically after the programme has finished? How have the participants succeeded in creating the content of the programme in their daily lives? How do the participants assess their health compared to before they participated in the programme? Are there any beneficial factors highlighted by the participants as during the program? The study was conducted on the basis of semi-structured interviews with eight voluntary participants who previously participated in the Get Started Programme. The results show that six of the eight participants succeeded to get started with the goals for behavioral change, and still maintain a sufficient physical activity level today. Participants who do not consider themselves to have succeeded in reaching the goals they set up in the beginning of the program, point out that they have the tools needed to go on and continue the behavioral change they strive for

    A characteristic frequency of two mutually interacting gas bubbles in an acoustic field

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    Transition frequencies of two spherical gas bubbles interacting in an acoustic field are discussed theoretically. In the present study, transition frequency is defined as the frequency of external sound for which the phase difference between a bubble's pulsation and the external sound is π/2\pi / 2. It is shown by a linear theory that a bubble interacting with a neighboring bubble has three (or fewer) transition frequencies but only two natural frequencies. This result means that the bubble has a characteristic frequency besides the natural frequencies.Comment: 14 pages, 5 figures, elsart, "Eigenfrequency" replaced with "transition frequency" and a reference added, accepted for publication in Phys. Lett.

    Rapid Formation of Saturn after Jupiter Completion

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    We have investigated Saturn's core formation at a radial pressure maximum in a protoplanetary disk, which is created by gap opening by Jupiter. A core formed via planetesimal accretion induces the fragmentation of surrounding planetesimals, which generally inhibits further growth of the core by removal of the resulting fragments due to radial drift caused by gas drag. However, the emergence of the pressure maximum halts the drift of the fragments, while their orbital eccentricities and inclinations are efficiently damped by gas drag. As a result, the core of Saturn rapidly grows via accretion of the fragments near the pressure maximum. We have found that in the minimum-mass solar nebula, kilometer sized planetesimals can produce a core exceeding 10 Earth masses within two million years. Since Jupiter may not have undergone significant type II inward migration, it is likely that Jupiter's formation was completed when the local disk mass has already decayed to a value comparable to or less than Jovian mass. The expected rapid growth of Saturn's core on a timescale comparable to or shorter than observationally inferred disk lifetime enables Saturn to acquire the current amount of envelope gas before the disk gas is completely depleted. The high heat energy release rate onto the core surface due to the rapid accretion of the fragments delays onset of runaway gas accretion until the core mass becomes somewhat larger than that of Jupiter, which is consistent with the estimate based on interior modeling. Therefore, the rapid formation of Saturn induced by gap opening of Jupiter can account for the formation of multiple gas giants (Jupiter and Saturn) without significant inward migration and larger core mass of Saturn than that of Jupiter.Comment: Accepted for publication in Ap

    Thermal evolution and lifetime of intrinsic magnetic fields of Super Earths in habitable zones

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    We have numerically studied the thermal evolution of various-mass terrestrial planets in habitable zones, focusing on duration of dynamo activity to generate their intrinsic magnetic fields, which may be one of key factors in habitability on the planets. In particular, we are concerned with super-Earths, observations of which are rapidly developing. We calculated evolution of temperature distributions in planetary interior, using Vinet equations of state, Arrhenius-type formula for mantle viscosity, and the astrophysical mixing length theory for convective heat transfer modified for mantle convection. After calibrating the model with terrestrial planets in the Solar system, we apply it for 0.1--10M10M_{\oplus} rocky planets with surface temperature of 300~\mbox{K} (in habitable zones) and the Earth-like compositions. With the criterion for heat flux at the CMB (core-mantle boundary), the lifetime of the magnetic fields is evaluated from the calculated thermal evolution. We found that the lifetime slowly increases with the planetary mass (MpM_p) independent of initial temperature gap at the core-mantle boundary (ΔTCMB\Delta T_{\rm CMB}) but beyond a critical value Mc,pM_{c,p} (O(1)M\sim O(1)M_{\oplus}) it abruptly declines by the mantle viscosity enhancement due to the pressure effect. We derived Mc,pM_{c,p} as a function of ΔTCMB\Delta T_{\rm CMB} and a rheological parameter (activation volume, VV^*). Thus, the magnetic field lifetime of super-Earths with Mp>Mp,cM_p > M_{p,c} sensitively depends on ΔTCMB\Delta T_{\rm CMB}, which reflects planetary accretion, and VV^*, which has uncertainty at very high pressure. More advanced high-pressure experiments and first-principle simulation as well as planetary accretion simulation are needed to discuss habitability of super-Earths.Comment: 19pages, 15 figures, accepted for publication in Ap

    Digital competencies and capabilities. Pre-adolescents inside and outside school

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    The investment on key-competences in last years was one crucial European strategy to face the new challenges of the knowledge society and of the digital convergence and to guarantee the active citizenship and social inclusion. The first answer has been given in Lisbon 2000’s, when eight main objectives have been presented; they were focused on the improvement of basic and "soft" skills in educational paths of the main agencies (i.e. school and family). Hence, the digital competence, included in Lisbon strategies, can be interpreted in a double meaning: as basic skill (focused on the digital literacy) as soft skill (focused on the digital learning). Starting from here, this proposal will construct a theoretical description of the digital competence and its impact to cognitive processes of the children, considering the influence and the strategies applied by agencies of the social capital, especially the family. This issue will be analysed through the re-reading the capabilities approach by Sen and Nussbaum (2011), according two perspectives: 1. the first is psyco-cognitive connected to the development of digital competences during the learning process of children; 2. the second is focused on the relational and communicative styles of their socializing agencies. In the digital skills, the generation gap is more evident: the youngsters acquire the digital literacy through their experiences; however their digital knowledge is often technical and linguistic, while it isn’t a lot oriented to the metacognition of the digital media, such as the critical thinking or the creativity; on the other side, the educators don’t have the same familiarity with media and for this reason they not always understand needs, values and references of youngsters. The consumption styles of parents, their prejudices and their competences influence the relationship of children with media starting from their first digital experience, with social and cognitive consequences