6,678 research outputs found
Numerical modeling of dynamic powder compaction using the Kawakita equation of state
Dynamic powder compaction is analyzed using the assumption that the powder behaves, while it is being compacted, like a hydrodynamic fluid in which deviatoric stress and heat conduction effects can be ignored throughout the process. This enables techniques of computational fluid dynamics such the equilibrium flux method to be used as a modeling tool. The equation of state of the powder under compression is assumed to be a modified version of the Kawakita loading curve. Computer simulations using this model are performed for conditions matching as closely as possible with those from experiments by Page and Killen [Powder Metall. 30, 233 (1987)]. The numerical and experimental results are compared and a surprising degree of qualitative agreement is observed
Effect of passive evaporative cooler on physio -chemical properties of hot water treated Solanum melongena L.
Abstract: This study was conducted to investigate the effect of passive evaporative cooler on storage behavior - that is visual appearance, physiological loss in weight (PLW), color development, firmness, total soluble solids (TSS) and pH level of hot water treated eggplant fruit (Solanum melongena L.). Fresh harvested fruits were treated with hot water at 45°C for 1 h. The highest percentage of PLW (2.39%) was the fruit stored at ambient temperature of 25°C for nine days whereas the lowest percentage of weight loss (2.27%) was the fruit stored inside the passive evaporative cooler. In all cases, the decreasing rate of lightness (L* value) and increasing rate of greenness (a* value) and yellowness (b* value) of the hot water treated fruits were almost negligible. Firmness value of the fruits stored inside the passive evaporative cooler was found almost constant, while it reduced in fruits which stored at ambient temperature. Furthermore, higher TSS and lower pH value were observed in those fruits which were stored inside the passive evaporative cooler. In conclusion, the shelf life and quality of eggplant fruits can be extended using passive evaporative cooler. Keywords: fruit storage, fruit postharvest, freshness quality, shelf lif
Lipschitz shadowing implies structural stability
We show that the Lipschitz shadowing property of a diffeomorphism is
equivalent to structural stability. As a corollary, we show that an expansive
diffeomorphism having the Lipschitz shadowing property is Anosov.Comment: 11 page
Depositional constraints and age of metamorphism in southern India: U-Pb chemical (EMPA) and isotopic (SIMS) ages from the Trivandrum Block
We report UâPb electron microprobe (zircon and monazite) and Secondary Ion Mass Spectrometry (SIMS) UâPb (zircon) ages from a granulite-facies metapelite and a garnetâbiotite gniess from Chittikara, a classic locality within the Trivandrum Block of southern India. The majority of the electron-microprobe data on zircons from the metapelite define apparent ages between 1500 and 2500 Ma with a prominent peak at 2109±22 Ma, although some of the cores are as old as 3070 Ma. Zircon grains with multiple age zoning are also detected with 2500â3700 Ma cores, 1380â1520 mantles and 530â600 Ma outer rims. Some homogeneous and rounded zircon cores yielded late Neoproterozoic ages that suggest that deposition within the Trivandrum Block belt was younger than 610 Ma. The outermost rims of these grains are characterized by early Cambrian ages suggesting metamorphic overgrowth at this time. The apparent ages of monazite grains from this locality reveal multiple provenance and polyphase metamorphic history, similar to those of the zircons. In a typical case, Palaeoproterozoic cores (1759â1967 Ma) are enveloped by late Neoproterozoic rims (562â563 Ma), which in turn are mantled by an outermost thin Cambrian rim ([similar]515 Ma). PbO v. ThO*2 plots for monazites define broad isochrons, with cores indicating a rather imprecise age of 1913±260 Ma (MSWD=0.80) and late Neoproterozoic/Cambrian cores as well as thin rims yielding a well-defined isochron with an age of 557±19 Ma (MSWD=0.82). SIMS UâPb isotopic data on zircons from the garnetâbiotite gneiss yield a combined core/rim imprecise discordia line between 2106±37 Ma and 524±150 Ma. The data indicate Palaeoproterozoic zircon formation with later partial or non-uniform Pb loss during the late Neoproterozoic/Cambrian tectonothermal event. The combined electron probe and SIMS data from the metapelite and garnetâbiotite gneiss at Chittikara indicate that the older zircons preserved in the finer-grained metapelite protolith have heterogeneous detrital sources, whereas the more arenaceous protolith of the garnetâbiotite gniess was sourced from a single-aged terrane. Our data suggest that the metasedimentary belts in southern India may have formed part of an extensive late Neoproterozoic sedimentary basin during the final amalgamation of the Gondwana supercontinent.M. Santosh, A. S. Collins, T. Morimoto and K. Yokoyam
VLBI Monitoring Observations of Water Masers Around the Semi-Regular Variable Star R Crateris
We monitored water-vapor masers around the semi-regular variable star R
Crateris with the Japanese VLBI Network (J-Net) at the 22 GHz band during four
epochs with intervals of one month. The relative proper motions and
Doppler-velocity drifts of twelve maser features were measured. Most of them
existed for longer than 80 days. The 3-D kinematics of the features indicates a
bipolar expanding flow. The major axis of the asymmetric flow was estimated to
be at P.A. = 136 degrees. The existence of a bipolar outflow suggests that a
Mira variable star had already formed a bipolar outflow. The water masers are
in a region of apparent minimum radii of 1.3 x 10^12 m and maximum radii of 2.6
x 10^12 m, between which the expansion velocity ranges from 4.3 to 7.4 km/s.
These values suggest that the water masers are radially accelerated, but still
gravitationally bound, in the water-maser region. The most positive and
negative velocity-drifting features were found relatively close to the systemic
velocity of the star. We found that the blue-shifted features are apparently
accelerated and the red-shifted apparently decelerated. The acceleration of
only the blue-shifted features seems to be consistent with that of the
expanding flow from the star.Comment: 15 pages, 5 figures, Accepted for publication in PASJ (2001),
preprint can be obtained via WWW on
http://www.nro.nao.ac.jp/library/report/list.htm
Nihongo gakushusha no daigaku deno gakushu keiken - mochibeshon no kanten kara (How do post-beginners feel about their experience of learning Japanese at a university?: From a motivational point of view)
Whilst the need for âarticulationâ has been called for in the field of Japanese education worldwide in recent years (Tohsaku (2009) etc.), bridging between school and university has become a particularly important issue in the UK where the number of learners is increasing at secondary schools (J-GAP Europe (2013)).
In fact, having analysed the five-year data for those who entered the Japanese degree programme at the University of Leeds between 2005 and 2009, no significant difference was observed in terms of the Japanese language skills achieved at the time of graduation between those students who had studied Japanese for qualifications at secondary schools (âpost-beginnersâ) and those who started learning Japanese from scratch at university. This may suggest that the Japanese programme at the University may not successfully provide those post-beginners with the best opportunities to make the most of their previous learning experience.
However, previous research dealing with issues of articulation is limited in number, and few studies have closely examined how post-beginners find their experience of learning Japanese and how their attitude and motivation affect their ability to attain Japanese language skills.
Using both questionnaires and semi-structured interviews involving the first-year students in Leeds, this research will investigate what the post-beginnersâ initial motivations are and how they develop over their course of study. Furthermore, retrospective feedback on their experience of learning Japanese will be obtained from the upper-year students who had studied Japanese before coming to Leeds via a questionnaire. Based on Sakai & Kikuchi (2009) and other previous studies, these sources of data will be analysed from the perspective of demotivational factors, and discussed in terms of how the Japanese programme could be improved by referring to the motivation strategies proposed by Dörnyei (2001) and Dörnyei and Ushioda (2011).
References:
Tohsaku, Y. 2009. AP Japanese Language and Culture Program and Articulation, The 23rd Conference of the Japanese Teachers Association of New England and The 14th Conference of the Northeast Council of Teachers of Japanese Proceedings, 20 June 2009, Amherst College, USA, [Accessed 10 January 2014], Available from World Wide Web:
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Dörnyei, Z. 2001. Teaching and Researching Motivation. Harlow: Longman.
Dörnyei, Z. and Ushioda, E. 2011. Teaching and Researching Motivation. Harlow: Longman.
Japanese Global Articulation Project (J-GAP) Europe. 2013. Japanese Language Education in the UK â The Transition between Secondary School and University. J-GAP Europe
Sakai, H., and Kikuchi, K, 2009. An analysis of demotivators in the EFL classroom.System,37(1), [Accessed 10 January 2014], pp. 57-69. Available from World Wide Web:
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