The β-polymorph of uranium phosphide selenide

β-UPSe was synthesized from the reaction of U2Se3, P and Se in a CsCl flux in a fused-silica tube. It crystallizes with four formula units in the tetra­gonal space group I4/mmm in the UGeTe structure type. The asymmetric unit comprises one U (site symmetry 4mm), one Se (4mm), and one P (mmm.) atom. The U atom is coordinated in a monocapped square-anti­prismatic arrangement, where the square face is formed by P atoms and the other five vertices are Se atoms. The P site is disordered about a mirror plane, showing half-ocupancy for each of the two resulting P atoms. The title structure is related to that of α-UPSe, which crystallizes with two formula units in the tetra­gonal space group P4/nmm in the PbFCl structure type

Dilatometry study of the ferromagnetic order in single-crystalline URhGe

Thermal expansion measurements have been carried out on single-crystalline URhGe in the temperature range from 2 to 200 K. At the ferromagnetic transition (Curie temperature T_C = 9.7 K), the coefficients of linear thermal expansion along the three principal orthorhombic axes all exhibit pronounced positive peaks. This implies that the uniaxial pressure dependencies of the Curie temperature, determined by the Ehrenfest relation, are all positive. Consequently, the calculated hydrostatic pressure dependence dT_C/dp is positive and amounts to 0.12 K/kbar. In addition, the effective Gruneisen parameter was determined. The low-temperature electronic Gruneisen parameter \Gamma_{sf} = 14 indicates an enhanced volume dependence of the ferromagnetic spin fluctuations at low temperatures. Moreover, the volume dependencies of the energy scales for ferromagnetic order and ferromagnetic spin fluctuations were found to be identical.Comment: 5 page

Incidencia de corazón mohoso del manzano en Talca, Linares y Chillan (Chile), y su relación con las características morfológicas del fruto e índices de madurez

Resumen (Spanish, English)72 p.Frutos de manzanos variedades Red King Oregon, Starkrimson y Richard, provenientes de las localidades de Talca, Linares y Chillán, fueron analizados para determinar la incidencia de corazón mohoso y su posible relación con la zona de origen de la fruta; presencia, longitud y ancho del conducto calicinal, deformaciones calicinales e índices de madurez. Los resultados mostraron que en la variedad Red King Oregon, Starkrimson y Richared, respectivamente). No se observó diferencia significativa de la incidencia de la enfermedad en las tres localidades analizadas. En cuanto a severidad la enfermedad se manifestó en un 98.9% limitada a la cavidad carpelar, para las tres variedades estudiadas. Se obtuvo en forma individual una baja correlación entre la incidencia de corazón mohoso y presencia (r=0.39), longitud (r=0.07), ancho (r=0.16), relación longitud/ancho (r=0.09). De igual manera, se obtuvo una baja correlación entre la incidencia de corazón mohoso y firmeza de pulpa (r=0.17), sólidos solubles r=0.18), intensidad (r=0.22) y cubrimiento (r=0.14) de color rojo, y deformaciones calicinales (r=0.1) en el fruto

Actinoid pnictides--I : Heat capacities from 5 to 950 K and magnetic transitions of U3As4 and U3Sb4. Ferromagnetic transitions

The heat capacities of triuranium tetraarsenide (U3As4) and triuranium tetraantimonide (U3Sb4), measured by adiabatic calorimetry over the temperature range 5-950 K, show sharp [lambda]-shaped transitions at 196.1 and 147.5 K, respectively. The maxima are related to the appearance of permanent magnetic moments below 198 and 148 K. Excess cooperative entropies associated with ferromagnetic ordering are tentatively estimated as 6.7 for U3As4 and 6.8 cal K-1 mole-1 for U3Sb4. These are larger than the two literature values reported for U3P4 (1.5 and 3.1 cal K-1 mole-1). The fact that these entropy of transition values are much smaller than would be expected from [Delta]St = R In (2J + 1) for the 3H4 ground term (J = 4) and that the observed heat capacities at high temperatures are much larger than would be expected from lattice plus dilational contributions are evidence of crystal field effects. The total electronic entropies to 950 K are estimated as 11.05 and 12.95 cal K-1 mole-1 for U3As4 and U3Sb4, respectively. Thermal functions for both U3As4 and U3Sb4 are integrated from the experimental data up to 950 K. At 298.15 K, the values of Cpo [So(T)-So(0)] and -{[Go(T)-Ho(0)]/T} in cal K-1 mole-1, are 44.82, 73.87 and 38.97, U3As4 and 44.98, 83.60 and 46.89, for U3Sb4.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23080/1/0000655.pd

Quality and complexity measures for data linkage and deduplication

Summary. Deduplicating one data set or linking several data sets are increasingly important tasks in the data preparation steps of many data mining projects. The aim of such linkages is to match all records relating to the same entity. Research interest in this area has increased in recent years, with techniques originating from statistics, machine learning, information retrieval, and database research being combined and applied to improve the linkage quality, as well as to increase performance and efficiency when linking or deduplicating very large data sets. Different measures have been used to characterise the quality and complexity of data linkage algorithms, and several new metrics have been proposed. An overview of the issues involved in measuring data linkage and deduplication quality and complexity is presented in this chapter. It is shown that measures in the space of record pair comparisons can produce deceptive quality results. Various measures are discussed and recommendations are given on how to assess data linkage and deduplication quality and complexity. Key words: data or record linkage, data integration and matching, deduplication, data mining pre-processing, quality and complexity measures

Actinoid pnictides--II : Heat capacities of UAs2 and USb2 from 5 to 750 K and antiferromagnetic transitions

The heat capacities of uranium diarsenide (UAs2) and uranium diantimonide (USb2), with tetragonal structures of the anti-Cu2Sb-type, have been measured by adiabatic-shield calorimetry from 5 to about 750 K. Lambda-type transitions with maxima at 272.2 and 202.5 K for UAs2 and USb2, respectively, are related to maxima in the magnetic susceptibilities at 277 and 203 K, occasioned by transitions from antiferro- to paramagnetism in the compounds. Values of the heat capacities (Cp), entropies [S[deg](T) - S[deg](0)], and Gibbs energy functions -{[G[deg](T) - H[deg](o)]/T} at 298.15 K in cal K-1 mole-1 are 19.12, 29.41 and 15.05 for UAs2 and 19.16, 33.81 and 18.39 for USb2. Tentative resolutions of the cooperative magnetic heat capacities of UAs2 and USb2 lead to the magnetic entropies [Delta]S(mag) = 0.99 and 1.70 cal K-1 mole-1, respectively. The values for both are significantly lower than the spin-only magnetic entropy value R ln 3 = 2.18 cal K-1 mole-1.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22763/1/0000318.pd