1,441 research outputs found
Magnetotransport in the CeIrIn system: The influence of antiferromagnetic fluctuations
We present an overview of magnetotransport measurements on the heavy-fermion
superconductor CeIrIn. Sensitive measurements of the Hall effect and
magnetoresistance (MR) are used to elucidate the low temperature phase diagram
of this system. The normal-state magnetotransport is highly anomalous, and
experimental signatures of a pseudogap-like precursor state to
superconductivity as well as evidence for two distinct scattering times
governing the Hall effect and the MR are observed. Our observations point out
the influence of antiferromagnetic fluctuations on the magnetotransport in this
class of materials. The implications of these findings, both in the context of
unconventional superconductivity in heavy-fermion systems as well as in
relation to the high temperature superconducting cuprates are discussed
Two Superconducting Phases in CeRh_1-xIr_xIn_5
Pressure studies of CeRh_1-xIr_xIn_5 indicate two superconducting phases as a
function of x, one with T_c >= 2 K for x < 0.9 and the other with T_c < 1.2 K
for x > 0.9. The higher T_c phase, phase-1, emerges in proximity to an
antiferromagnetic quantum-critical point; whereas, Cooper pairing in the lower
T_c phase-2 is inferred to arise from fluctuations of a yet to be found
magnetic state. The T-x-P phase diagram of CeRh_1-xIr_xIn_5, though
qualitatively similar, is distinctly different from that of
CeCu_2(Si_1-xGe_x)_2.Comment: 5 pages, 3 figure
Food: An Unrecognized Source of Loop Diuretic Resistance
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90131/1/phco.24.6.630.34736.pd
Magnetic structure of Cd-doped CeCoIn5
The heavy fermion superconductor CeCoIn5 is believed to be close to a
magnetic instability, but no static magnetic order has been found. Cadmium
doping on the In-site shifts the balance between superconductivity and
antiferromagnetism to the latter with an extended concentration range where
both types of order coexist at low temperatures. We investigated the magnetic
structure of nominally 10% Cd-doped CeCoIn5, being antiferromagnetically
ordered below T_N=3 K and superconducting below T_c=1.3 K, by elastic neutron
scattering. Magnetic intensity was observed only at the ordering wave vector
Q_AF = (1/2,1/2,1/2) commensurate with the crystal lattice. Upon entering the
superconducting state the magnetic intensity seems to change only little. The
commensurate magnetic ordering in CeCo(In1-xCdx)5 is in contrast to the
incommensurate antiferromagnetic ordering observed in the closely related
compound CeRhIn5. Our results give new insights in the interplay between
superconductivity and magnetism in the family of CeTIn5 (T=Co, Rh, and Ir)
based compounds.Comment: 4 pages, 4 figure
Superconductivity and Quantum Criticality in CeCoIn_5
Electrical resistivity measurements on a single crystal of the heavy-fermion
superconductor CeCoIn_5 at pressures to 4.2 GPa reveal a strong crossover in
transport properties near P^* \approx 1.6 GPa, where T_c is a maximum. The
temperature-pressure phase diagram constructed from these data provides a
natural connection to cuprate physics, including the possible existence of a
pseudogap.Comment: 4 pages, 4 figure
Consumption of 100% Fruit Juice is Associated with Better Nutrient Intake and Diet Quality but not with Weight Status in Children: NHANES 2007-2010
Objective: This study examined the impact of various levels of 100% fruit juice (FJ) consumption on intake of nutrients, diet quality, and weight in children using the more recent national data.Methods: This was a cross-sectional study examining the data from children 2-18 years of age (n=6,090). Intake of nutrients and diet quality were assessed using the 24-hr dietary recall and Healthy Eating Index-2010, respectively. Various consumption levels of 100% FJ were determined. Covariate adjusted linear regression means, and standard errors were determined (p<0.01).Results: Average per capita consumption of 100% FJ consumed was 3.6 fl oz (50 kilocalories; 2.9% energy intake); 30% of children 2-6 years exceeded the recommendation for 100% FJ. Among 100% FJ consumers, the mean amount of 100% FJ consumed was 10.6 fl oz (147 kilocalories; 8.4% energy intake). Intakes of vitamin C, magnesium, and potassium and overall diet quality were higher with more 100% FJ consumed; no difference was found in total fiber intake. No trends were seen in weight with increased amounts of 100% FJ consumed.Conclusions: Consumption of 100% FJ should be recommended as a component of a healthy diet
Relationship between Snacking Patterns, Diet Quality and Risk of Overweight and Abdominal Obesity in Children
Snacking is very common among Americans; the impact of variety of snacking patterns on nutrient intake and weight status is unclear. This study examined the associations of snacking patterns on nutrient intake and weight in U.S. children 2-18 years (n=14,220) participating in the 2001-2008 National Health and Nutrition Examination Survey. Cluster analysis generated 12 distinct snacking patterns, explaining 57% of variance in total calories consumed. Only 8% of the children did not consume snacks on the day of the 24-hour recall. Cakes, cookies and pastries was the most common snacking pattern (16%) followed by miscellaneous snacks (e.g. whole milk, orange juice and meat/fish/poultry; 13%), and crackers and salty snacks (10%). Most snacking patterns resulted in higher total energy intake than the no snack pattern. After controlling for energy intake, most snacking patterns resulted in higher intakes of fiber; vitamins A, C, B12, and K; riboflavin; folate; potassium; calcium; zinc; and magnesium than the no snack pattern. However, most of the snacking patterns resulted in higher total intake of saturated fatty acids, solid fats, added sugars, and sodium (nutrients to limit). Several of the snacking patterns (i.e. cakes/cookies/pastries, crackers/salty snacks, sweets, and other grains) were associated with a reduced risk of overweight and abdominal obesity. Overall, several snacking patterns compared with non-snackers had better diet quality and were less likely to be overweight or obese and less likely to have abdominal obesity. Education is needed to improve snacking patterns in terms of nutrients to limit in the diet
A precursor state to unconventional superconductivity in CeIrIn
We present sensitive measurements of the Hall effect and magnetoresistance in
CeIrIn down to temperatures of 50 mK and magnetic fields up to 15 T. The
presence of a low temperature coherent Kondo state is established. Deviations
from Kohler's rule and a quadratic temperature dependence of the cotangent of
the Hall angle are reminiscent of properties observed in the high temperature
superconducting cuprates. The most striking observation pertains to the
presence of a \textit{precursor} state--characterized by a change in the Hall
mobility--that appears to precede the superconductivity in this material, in
similarity to the pseudogap in the cuprate high superconductors.Comment: 4 figure
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