2,011 research outputs found

    New determination of zonal harmonics coeffi- cients of the earth's gravitational potential special report no. 165

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    Zonal harmonics coefficient determination of earth gravitational potentia

    Long term variation of the solar diurnal anisotropy of galactic cosmic rays observed with the Nagoya multi-directional muon detector

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    We analyze the three dimensional anisotropy of the galactic cosmic ray (GCR) intensities observed independently with a muon detector at Nagoya in Japan and neutron monitors over four solar activity cycles. We clearly see the phase of the free-space diurnal anisotropy shifting toward earlier hours around solar activity minima in A>0 epochs, due to the reduced anisotropy component parallel to the mean magnetic field. The average parallel component is consistent with a rigidity independent spectrum, while the perpendicular component increases with GCR rigidity. We suggest that this harder spectrum of the perpendicular component is due to contribution from the drift streaming. We find that the bidirectional latitudinal density gradient is positive in A>0 epoch, while it is negative in A<0 epoch, in accord with the drift model prediction. The radial density gradient, on the other hand, varies with ~11-year cycle with maxima (minima) in solar maximum (minimum) periods, but there is no significant difference seen between average radial gradients in A>0 and A<0 epochs. The average parallel mean free path is larger in A0. We also find, however, that parallel mean free path (radial gradient) appears to persistently increase (decreasing) in the last three cycles of weakening solar activity. We suggest that simple differences between these parameters in A>0 and A<0 epochs are seriously biased by these long-term trends.Comment: accepted for the publication in the Astrophysical Journa

    Life Satisfaction of Undergraduate Students: Extrinsic and Intrinsic Motivators

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    In college, choosing a major involves thinking about its extrinsic and intrinsic attributes, for instance its pecuniary benefits versus the degree to which it is internally rewarding. Some students may choose lucrative majors over those which they believe are internally rewarding and vice versa. Previous research has shown that those who pursue intrinsic goals are happier relative to those who pursue extrinsic ones. However, people tend to overestimate the life satisfaction gained by extrinsic needs while underestimating the satisfaction gained by intrinsic needs. It is possible that students choosing a major for reasons conflicting with their personal goals may suffer from lowered life satisfaction. Nonetheless, the temporary circumstances of college students may create a unique dynamic from what has previously been studied. 270 University of Hawai’i at Mānoa college students were surveyed at random. Constructs such as optimism and feelings of community, among others, were found to be indicators of increased life satisfaction. This research may suggest that factors such as the possibility of employment and financial prospects, in addition to other known correlates are key determinants of life satisfaction in college students.Economic

    Intrinsic Linking and Knotting of Graphs

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    An analog to intrinsic linking, intrinsic even linking, is explored in the first half of this paper. Four graphs are established to be minor minimal intrinsically even linked, and it is conjectured that they form a complete minor minimal set. Some characterizations are given, using the simplest of the four graphs as an integral part of the arguments, that may be useful in proving the conjecture. The second half of this paper investigates a new approach to intrinsic knotting. By adapting knot energy to graphs, it is hoped that intrinsic knotting can be detected through direct computation. However, graph energies are difficult to compute, and it is unclear whether they can be used to determine whether a graph is intrinsically knotted

    DEFORMATIONS OF REDUCIBLE SL(n, C) REPRESENTATIONS OF FIBERED 3-MANIFOLD GROUPS

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    Let M_φ be a surface bundle over a circle with monodromy φ : S → S. We study deformations of certain reducible representations of π_1(M_φ) into SL(n, C), obtained by composing a reducible representation into SL(2, C) with the irreducible representation SL(2, C) → SL(n, C). In particular, we show that under certain conditions on the eigenvalues of φ∗, the red cible representation is contained in a (n + 1 + k)(n − 1) dimensional component of the representation variety, where k is the number of components of ∂M_φ. This result applies to mapping tori of pseudo-Anosov maps with orientable invariant foliations whenever 1 is not an eigenvalue of the induced map on homology, where the reducible representation is also a limit of irreducible representations

    Heat dissipation in water-cooled reflectors

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    The energy balance of a lamp varies with the thermal and optical characteristics of the reflector. The photosynthetic radiation efficiency of lamps, defined as input power divided by photosynthetically active radiation (PAR, 400-700 nm) emitted from the lamp ranges between 0.17 and 0.26. The rest of the energy input is wasted as longwave (3000 nm and over) and non-PAR shortwave radiation (from 700 nm to 3000 nm), convective, and conductive heat from the lamp, reflector, and ballast, and simply for increasing the cooling load. Furthermore, some portion of the PAR is uselessly absorbed by the inner walls, shelves, vessels, etc. and some portion of the PAR received by the plantlets is converted into sensible and latent heat. More than 98% of the energy input is probably converted into heat, with only less than 2% of the energy input being converted into chemical energy as carbohydrates by photosynthesis. Therefore, it is essential to reduce the generation of heat in the culture room in order to reduce the cooling load. Through use of a water-cooled reflector, the generation of convective and conductive heat and longwave radiation from the reflector can be reduced, without reduction of PAR

    四国中・東部の前期白亜紀非海生二枚貝動物群

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    Cretaceous non-marine faunas in Central and Eastern Shikoku can be classified into the Masaki and Sakashu faunal groups on the basis of their taxonomic components and a new stratigraphy and tectonic subdivision of the Chichibu Superbelt. The non-marine bivalves from the Monobegawa Group in the Masaki Belt belong to the Masaki Faunal Group which are identified the Hauterivian Tatsukawa fauna, Late Barremian Yunoki fauna and Early Aptian Hibihara fauna. The non-marine bivalves from the Nankai and Takegatani groups of the Sakashu Belt belong to the Sakashu Faunal Group which are identified the Hauterivian Shobu fauna. The three faunas of the Masaki Faunal Group in Central and East Shikoku are found in stratigraphic order. The Masaki Faunal Group is characterized by the brackish- and freshwater mollusks. On the other hand, the Sakashu Faunal Group is characterized by the brackish-water mollusks. It suggests that salinity is the main differential factor between the Hauterivian faunas in the Masaki and Sakashu faunal groups. A Hauterivian mixed assemblage of the Tatsukawa and Shobu faunas was found in Central Shikoku. The finding suggests that the two faunas were formed in different salinity environment and adjoining areas.四国中・東部秩父累帯下部白亜系の非海生二枚貝類について種構成や群集の生息環境を考察し,再編された地帯区分との対応を検討した.これらの白亜紀非海生動物群は新たな秩父累帯の地帯区分及び種構成に墓づいて,互いに共通種を持たない正木動物群(Masaki Faunal Group)と坂州動物群(Sakashu Faunal Group)に区分される.正木帯に属する物部川層群の非海生二枚貝類は正木動物群に帰属し,立川フォーナ(Hauterivian),柚ノ木フォーナ(Late Barremian),日比原フォーナ(Early Aptian)で構成される.坂州帯に属する南海層群,竹ヶ谷層群の非海生二枚貝類は坂州動物群に帰属し,菖蒲フォーナ(Hauterivian)で特徴づけられる.四国中・東部における正木動物群は,汽水生一淡水生軟体動物で特徴づけられ,坂州動物群は汽水生軟体動物で特徴づけられる.このことは,坂州動物群は正木動物群より塩分濃度の高い環境で生息したことを示す.また,四国中央部では両動物群の混在が確認され,正木動物群と坂州動物群は,隣接して存在し,塩分濃度の異なる環境に生息したことが推測される
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