16,827 research outputs found

    Red-shift arising from light passage in a magnetic field Semiannual report

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    Photon-photon scattering model for red shift of light passing through magnetic fiel

    Competing magnetic interactions in CeNi9-xCoxGe4

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    CeNi9Ge4 exhibits outstanding heavy fermion features with remarkable non-Fermi- liquid behavior which is mainly driven by single-ion effects. The substitution of Ni by Cu causes a reduction of both, the RKKY coupling and Kondo interaction, coming along with a dramatic change of the crystal field (CF) splitting. Thereby a quasi-quartet ground state observed in CeNi9Ge4 reduces to a two-fold degenerate one in CeNi8CuGe4. This leads to a modiffcation of the effective spin degeneracy of the Kondo lattice ground state and to the appearance of antiferromagnetic (AFM) order. To obtain a better understanding of consequences resulting from a reduction of the effective spin degeneracy, we stepwise replaced Ni by Co. Thereby an increase of the Kondo and RKKY interactions through the reduction of the effective d-electron count is expected. Accordingly, a paramagnetic Fermi liquid ground state should arise. Our experimental studies, however, reveal AFM order already for small Co concentrations, which becomes even more pronounced with increasing Co content x. Thereby the modiffcation of the effective spin degeneracy seems to play a crucial role in this system

    It's all action, it's all learning: Action learning in SMEs

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    Purpose - The purpose of this paper is to argue that action learning (AL) may provide a means of successfully developing small to medium-sized enterprises (SMEs). Design/methodology/approach - The literature around SME learning suggests a number of processes are important for SME learning which similarity, it is argued, are encompassed in AL. AL may therefore offer a means of developing SME. This argument is then supported through the results of a longitudinal qualitative evaluation study conducted in the north-west of England, which involved the use of AL in 100 SMEs. Findings - The paper finds that the discursive and critical reflection aspects of the set environment appeared to be of great utility and importance to the SMEs. Sets also had an optimum level of which helped them find "common ground". Once common ground was established set members often continued to network and form alliances outside of the set environment. SME owner-managers could discuss both personal and business. Finally, AL offered the opportunity to take time out of the business and "disengage" with the operational allowing them to become more strategic. Practical implications - In this paper both the literature review and the results of the evaluation suggest AL may offer a means of engaging SMEs in training, which is relevant and useful to them. AL offers a way for policy makers and support agencies to get involved with SME management development while retaining context and naturalistic conditions. Originality/value - This paper attempts to move beyond other articles which assess SME response to government initiatives, through examining the literature around SME learning and constructing a rationale which proposes that AL encompasses many of the learning processes suggested in the literature as effective for SME development. © Emerald Group Publishing Limited

    The search for the cause of the low albedo of the moon

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    Experimentation concerning lunar weathering and its effect on the albedo of the surface cover consisted of: (1) determination of the surface chemical composition of lunar soil and ground-up rock samples by Auger electron spectroscopy, (2) measurement of the optical albedo of these samples, and (3) proton or alpha-particle irradiation of terrestrial rock chips and rock powders and of ground-up lunar rock samples in order to determine the optical and surface chemical effect of simulated solar wind

    The Surface Chemical Composition of Lunar Samples and Its Significance for Optical Properties

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    The surface iron, titanium, calcium, and silicon concentration in numerous lunar soil and rock samples was determined by Auger electron spectroscopy. All soil samples show a large increase in the iron to oxygen ratio compared with samples of pulverized rock or with results of the bulk chemical analysis. A solar wind simulation experiment using 2 keV energy alpha -particles showed that an ion dose corresponding to approximately 30,000 years of solar wind increased the iron concentration on the surface of the pulverized Apollo 14 rock sample 14310 to the concentration measured in the Apollo 14 soil sample 14163, and the albedo of the pulverized rock decreased from 0.36 to 0.07. The low albedo of the lunar soil is related to the iron + titanium concentration on its surface. A solar wind sputter reduction mechanism is discussed as a possible cause for both the surface chemical and optical properties of the soil

    Antiferromagnetic behavior in CeCo9_{9}Ge4_{4}

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    We investigate the novel intermetallic ternary compounds \emph{R}Co9_{9}Ge4_{4} with \emph{R} = La and Ce by means of XX-ray diffraction, susceptibility and specific heat measurements. CeCo9_{9}Ge4_{4} crystallizes in the space group I{I} 4/ mcm{mcm} and is characterized by the coexistence of two different magnetic sublattices. The Ce-based sublattice, with an effective moment close to the expected value for a Ce3+^{3+}-ion, exhibits a magnetically ordered ground state with TN=12.5T_{\mathrm{N}}=12.5 K. The Co-based sublattice, however, exhibits magnetic moments due to itinerant 3dd electrons. The magnetic specific heat contribution of the Ce-sublattice is discussed in terms of a resonance-level model implying the interplay between an antiferromagnetic phase transition and the Kondo-effect and an underlying Schottky-anomaly indicating a crystal field level scheme splitting into three twofold degenerated micro states (Δ1=69\Delta_1 = 69 K, Δ2=133\Delta_2 = 133 K).Comment: 4 pages, 3 figures, conference SCES0

    Lead Mining and the Survival and Demise of French in Rural Missouri

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    Tout ce qui reste du Missouri français, c'est Vieilles Mines : un résidu des ambitions coloniales française et espagnole du 18e siècle. La présence de riches gisements de plomb servit à l'époque d'appât pour attirer, dans ce qui est aujourd'hui le comté de Washington, plusieurs coloniaux. La demande pour le plomb (arraché à la main à même le tuf), et plus tard pour la barite, permirent aux mineurs français de conserver, et ce jusqu'à la dernière guerre mondiale, une certaine authenticité dans leur mode de vie, leur langue et leur culture. Mais depuis, les Français du Missouri disparaissent petit à petit. Pourtant, au moment de l'effondrement apparent de la langue et de la culture, certains cherchent à renverser la vapeur, et à insuffler une nouvelle vie à cette culture moribonde.Old Mines is just about all that remains of French Missouri, a remnant of eighteenth century French and Spanish colonial ambitions. Rich lead deposits attracted the early French to what is now Washington county. The demand for hand dug lead (tuf) and later barite permitted French miners to continue their mode of production with its linguistic and cultural complementarities until World War II. Since, the Missouri French have been gradually disappearing. Yet even at moments of virtual cultural and linguistic collapse, voices are raised in an effort to rectify the situation

    The French Frontier of Settlement in Louisiana : Some Observations on Cultural Change in Mamou Prairie

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    C'est à travers l'étude ethno-historique des communautés de métayers d'avant 1952, et des déplacements subséquents des tenanciers vers les petites villes, que l'on peut le mieux interpréter les mutations culturelles cadjines des « Prairies » du sud-ouest de la Louisiane. L'isolement des métayers francophones fut renforcé par une idéologie égalitaire. De ce milieu, la musique cadjine émergea comme l'un des indices de la société louisianaise francophone. Le déclin de la culture du coton entraîna des perturbations dans l'équilibre démographique entre le milieu agricole et le village, favorisant ainsi réclusion d'une classe marchande issue des rangs des agriculteurs. Au moyen d'une réinterprétation de la culture rurale en milieu urbain, cette nouvelle bourgeoisie chercha à garantir la survivance culturelle. Utilisant la radio, les journaux, et se servant de l'appui externe des « puristes » du folklore, ils exploitèrent d'une manière sélective les traits ethniques. Bien que promu sur la place publique, le français continua à se dévaloriser en milieu privé ou familial.L'impact de cette transformation diffère selon les groupes. Les métayers à la retraite de Mamou, les plus authentiquement cadjins par leur attachement quotidien aux valeurs sociales et linguistiques traditionnelles, sont les moins susceptibles de promouvoir la survivance et la transmission de cette culture.Changes in Cajun culture of the Southwestem Prairies of Louisiana can best be explained through the ethnohistorical study of pre-1952 cotton sharecropping communities, and the subsequent displacement of the tenant farmers to service centres. Isolation of the sharecroppers was culturally-reinforced by a strong egalitarian ideology. From this milieu, Cajun music emerged as a marker of an indigenous Louisiana francophone society. The decline of cotton cultivation reversed the demographic balance between countryside and village and favoured the emergence of merchant and service strata composed of former farmers. The new bourgeoisie sought means of cultural revival through the reinterpretation of rural culture in a town context. Using radio, newspapers and the strong external support of folk "purists" they selectively cultivated ethnic differences. French was strengthened in a public context even though it continued to decline in private and familial contexts.The response to this transformation differs among occupation groups. Retired sharecroppers in Mamou, the most "Cajun" in their everyday retention of "traditional" social and linguistic behaviour, are the least likely to advocate the survival of that culture and its transmission to another generation
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