6,239 research outputs found
Immigrants, Medicaid, and the Deficit Reduction Act
This study examines the effects of the Deficit Reduction Act (DRA) on immigrant Medicaid participation using data from the 2005 and 2007 March supplements of the Current Population Survey. The DRA made changes to Medicaid coverage laws by requiring proof of citizenship for eligibility rather than a sworn statement, as was the case prior to the DRA, thus reducing the non-citizen/non-legal permanent resident use of Medicaid. A difference-in-difference methodology is used, and the research finds that the laws were effective in decreasing non-citizen use of Medicaid relative to citizens, though there is a possibility of “chilling effects” on eligible non-citizens
Toward a Theory of Emotions in Competitive Sports
In this article, we introduce a theory on the dynamic development of affective processes, affect regulation, and the relationship between emotions and sport performance. The theory focusses on how affective processes emerge and develop during competitive sport involvement. Based on Scherer’s component process model, we postulate six components of emotion that interact with each other in a circular fashion: (I) triggering processes, (II) physiological reactions, (III) action tendencies, (IV) expressive behaviors, (V) subjective experience, and (VI) higher cognitive processes. The theory stresses the dynamics of affective processes and describes the consequences for performance in competitive sports. It assumes that the peculiarities of different sports must be taken into account in order to understand the affective processes, and offers starting points on which strategies can be used to effectively regulate affective states. Consequences for research and practice are derived and discussed. To study the development of affective processes, future research should test the assumptions in ecologically valid contexts, such as real competitions or competition-like situations, using multi-component measures of emotions
Co dimers on hexagonal carbon rings proposed as subnanometer magnetic storage bits
It is demonstrated by means of density functional and ab-initio quantum
chemical calculations, that transition metal - carbon systems have the
potential to enhance the presently achievable area density of magnetic
recording by three orders of magnitude. As a model system, Co_2-benzene with a
diameter of 0.5 nm is investigated. It shows a magnetic anisotropy in the order
of 0.1 eV per molecule, large enough to store permanently one bit of
information at temperatures considerably larger than 4 K. A similar performance
can be expected, if cobalt dimers are deposited on graphene or on graphite. It
is suggested that the subnanometer bits can be written by simultaneous
application of a moderate magnetic and a strong electric field.Comment: 13 pages, 4 figure
IDENTIFICATION OF TREATED-COLOR FRESHWATER CULTURED PEARLS
Ta τελευταία 30 χρόνια η ζήτηση των χρωματιστών μαργαριταριών (όπου είναι σπανιότερα από τα λευκά) έχει ανέβει κατακόρυφα. Αποτέλεσμα αυτού είναι η εισροή στην αγορά μαργαριταριών με τεχνητό χρώμα, η αναγνώριση των οποίων απασχολεί έντονα τους γεμμολόγους. Για την αναγνώριση, τα μαργαριτάρια εξετάζονται μακροσκοπικά και μικροσκοπικά, γίνονται μετρήσεις φθορισμού σε ακτίνες-Χ (EDXRF) και τέλος μελετώνται οι ακτινογραφίες τους. Με τη χρήση ωστόσο των παραπάνω μεθόδων δεν καθίσταται, πάντα, εφικτή η αναγνώριση των τεχνητά χρωματισμένων μαργαριταριών. Παλαιότερες έρευνες έδειξαν ότι η φασματοσκοπία Raman είναι χρήσιμη στην αναγνώριση των χρωστικών ουσιών των μαργαριταριών γλυκού νερού. Στη παρούσα εργασία παρουσιάζονται μετρήσεις του φαινομένου Raman, με τη χρήση πράσινου laser, σε 35 φυσικά και 15 τεχνητά χρωματισμένα δείγματα. Όλα τα φάσματα Raman των φυσικά χρωματισμένων δειγμάτων παρουσιάζουν δύο κορυφές, όπου είναι χαρακτηριστικές για τις πολυακετυλενικές χρωστικές ουσίες. Αυτές οι κορυφές είναι παρούσες, ανεξαρτήτως του χρώματος των δειγμάτων, και οφείλονται στη δόνηση τάσης (stretching) των μορίων του των διπλών δεσμών άνθρακα (C—C) -στα 1530(±25) cm'1- και των μονών δεσμών άνθρακα (CC) -στα 1130(±10) cm'1- των χρωστικών ουσιών. Στη παρούσα εργασία προτείνεται ότι η πιθανή απουσία των παραπάνω κορυφών Raman σε ένα χρωματιστό μαργαριτάρι γλυκού νερού αποτελεί απόδειξη ότι το χρώμα του μαργαριταριού αυτού είναι τεχνητό.Demand for colored pearls has grown during the last thirty years. Colored pearls are rarer than white ones. Thus treated-color pearls have entered the marketplace and their identification became a challenge for the gemologists. With only the help of visual observation, EDXRF and X-radiography, methods that are used today for pearls identification, it is not always easy to identify them. Previous studies, have established that Raman scattering is useful to detect pigments in cultured freshwater pearls. The present study is based on the measurement of the Raman spectroscopy of 35 natural colored freshwater pearls and 15 treated-color freshwater pearls, covering a wide range of typical colors for this material, with green excitation. All natural- color pearls show the two major Raman resonance features of polacetyenic pigments assigned to C=C stretching-at about 1530(±25) cm'1- and C-C stretching - at about 1130(±10) cm' -, regardless of their specific hue. In this paper it is proposed that the absence of these Raman features prove the artificial origin of pigments in a colored freshwater cultured pearl
Antiferromagnetic Phases of One-Dimensional Quarter-Filled Organic Conductors
The magnetic structure of antiferromagnetically ordered phases of
quasi-one-dimensional organic conductors is studied theoretically at absolute
zero based on the mean field approximation to the quarter-filled band with
on-site and nearest-neighbor Coulomb interaction. The differences in magnetic
properties between the antiferromagnetic phase of (TMTTF)X and the spin
density wave phase in (TMTSF)X are seen to be due to a varying degrees of
roles played by the on-site Coulomb interaction. The nearest-neighbor Coulomb
interaction introduces charge disproportionation, which has the same spatial
periodicity as the Wigner crystal, accompanied by a modified antiferromagnetic
phase. This is in accordance with the results of experiments on (TMTTF)Br
and (TMTTF)SCN. Moreover, the antiferromagnetic phase of (DI-DCNQI)Ag
is predicted to have a similar antiferromagnetic spin structure.Comment: 8 pages, LaTeX, 4 figures, uses jpsj.sty, to be published in J. Phys.
Soc. Jpn. 66 No. 5 (1997
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