The butterfly diagram in the 18th century

Digitized images of the drawings by J.C. Staudacher were used to determine sunspot positions for the period of 1749-1796. From the entire set of drawings, 6285 sunspot positions were obtained for a total of 999 days. Various methods have been applied to find the orientation of the solar disk which is not given for the vast majority of the drawings by Staudacher. Heliographic latitudes and longitudes in the Carrington rotation frame were determined. The resulting butterfly diagram shows a highly populated equator during the first two cycles (Cycles 0 and 1 in the usual counting since 1749). An intermediate period is Cycle 2, whereas Cycles 3 and 4 show a typical butterfly shape. A tentative explanation may be the transient dominance of a quadrupolar magnetic field during the first two cycles.Comment: Accepted for publication in Solar Physics, 1 table, 2 figure

Kinetics and Jamming Coverage in a Random Sequential Adsorption of Polymer Chains

Using a highly efficient Monte Carlo algorithm, we are able to study the growth of coverage in a random sequential adsorption (RSA) of self-avoiding walk (SAW) chains for up to 10^{12} time steps on a square lattice. For the first time, the true jamming coverage (theta_J) is found to decay with the chain length (N) with a power-law theta_J propto N^{-0.1}. The growth of the coverage to its jamming limit can be described by a power-law, theta(t) approx theta_J -c/t^y with an effective exponent y which depends on the chain length, i.e., y = 0.50 for N=4 to y = 0.07 for N=30 with y -> 0 in the asymptotic limit N -> infinity.Comment: RevTeX, 5 pages inclduing figure

Role of substrate clamping on anisotropy and domain structure in the canted antiferromagnet alpha Fe2O3

Antiferromagnets have recently been propelled to the forefront of spintronics by their high potential for revolutionizing memory technologies. For this, understanding the formation and driving mechanisms of the domain structure is paramount. In this work, we investigate the domain structure in a thin film canted antiferromagnet amp; 945; amp; 8722;Fe2O3. We find that the internal destressing fields driving the formation of domains do not follow the crystal symmetry of amp; 945; amp; 8722;Fe2O3, but fluctuate due to substrate clamping. This leads to an overall isotropic distribution of the N el order with locally varying effective anisotropy in antiferromagnetic thin films. Furthermore, we show that the weak ferromagnetic nature of amp; 945; amp; 8722;Fe2O3 leads to a qualitatively different dependence on the magnetic field compared to collinear antiferromagnets such as NiO. The insights gained from our work serve as a foundation for further studies of electrical and optical manipulation of the domain structure of antiferromagnetic thin film

Division of family property in Taiwan

Since property ownership affords the elderly some control over resources and perhaps even support and respect from potential caretakers, examination of the decision to transfer property to children can help us gain insight into the underlying dynamics of intergenerational exchanges between the elderly and their children. In this paper we use data from the 1989 Survey of Health and Living Status of the Elderly in Taiwan to explore the demographic and social characteristics associated with pre-mortem property division. From both bivariate and multivariate analyses, we find that the likelihood of property division is positively related to age, widowhood, natality in Taiwan, rural residence, and the number of living children, and negatively related to education. After controlling for other characteristics, our results show that widows are more than twice as likely as widowers to have divided all their property. These results lend statistical support to findings in the ethnographic literature on the Chinese family.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42992/1/10823_2004_Article_BF00973799.pd