Sr2V3O9 and Ba2V3O9: quasi one-dimensional spin-systems with an anomalous low temperature susceptibility

The magnetic behaviour of the low-dimensional Vanadium-oxides Sr2V3O9 and Ba2V3O9 was investigated by means of magnetic susceptibility and specific heat measurements. In both compounds, the results can be very well described by an S=1/2 Heisenberg antiferromagnetic chain with an intrachain exchange of J = 82 K and J = 94 K in Sr2V3O9 and Ba2V3O9, respectively. In Sr2V3O9, antiferromagnetic ordering at T_N = 5.3 K indicate a weak interchain exchange of the order of J_perp ~ 2 K. In contrast, no evidence for magnetic order was found in Ba2V3O9 down to 0.5 K, pointing to an even smaller interchain coupling. In both compounds, we observe a pronounced Curie-like increase of the susceptibility below 30 K, which we tentatively attribute to a staggered field effect induced by the applied magnetic field. Results of LDA calculations support the quasi one-dimensional character and indicate that in Sr2V3O9, the magnetic chain is perpendicular to the structural one with the magnetic exchange being transferred through VO4 tetrahedra.Comment: Submitted to Phy. Rev.

Rupture and Rhythm: A Phenomenology of National Experiences

This article investigates how people make sense of ruptures in the flow of everyday life as they enter new experiential domains. Shifts in being-in-time create breaks in the natural attitude that offer the opportunity to register national—or, for example, religious, gender, or class—experiences. People interpret ruptures in perception and proprioception by drawing connections with domains in which similar or contrasting kinds of disruption are evident. Normalizing the transition, rhythm—as both cadence and overall flow—helps people adjust to new circumstances, align action, and smooth subsequent ruptures. Based on extensive qualitative fieldwork, I examine the specific case of how novice and experienced tea ceremony practitioners in Japan move into, interpret, and normalize action within tea spaces

Studies of the Respiratory Dead Space Ⅱ: Variations of the respiratory dead space

The influences of additional dead space, tidal volume or muscular work upon the respiratory dead space were studied and the respiratory dead space in various pulmonary diseases was examined by the same Haldane method as in Part 1. The respiratory dead space increases in hyperpnae at will or at work, but the ratio of dead space to tidal volume i. e. VD/VT remains relatively constant. The respiratory dead space and VD/VT in pulmonal diseases are greater than in healthy state

Studies of the Respiratory Dead Space Ⅰ: The respiratory dead space in Japanese healthy sudjects

The respiratory dead space in Japanese healthy 45 males and 30 females were estimated by Bohr formula from the tidal volume and the CO(2) percenttage of alveolar and expired air in sitting posture during rest. The relationship between the respiratory dead space and other physical or respiratory data were analysed statistically. The mean value of the dead space was 138±21ml. for males and 109±14ml. for females. in Japan. And the ratio of dead space to tidal volume averaged 31 percentage for both males and females. The respiratory dead space showed a definite correlation with individual vital capacity and tidal volume