6,879 research outputs found
Health and Prisoner Reentry: How Physical, Mental, and Substance Abuse Conditions Shape the Process of Reintegration
Documents the health challenges released prisoners face and the impact of physical health conditions, mental illness, and substance abuse on the reentry process, including finding housing and employment, reconnecting with family, and avoiding recidivism
Magnetic anisotropy, first-order-like metamagnetic transitions and large negative magnetoresistance in the single crystal of GdPdSi
Electrical resistivity (), magnetoresistance (MR), magnetization,
thermopower and Hall effect measurements on the single crystal
GdPdSi, crystallizing in an AlB-derived hexagonal structure are
reported. The well-defined minimum in at a temperature above N\'eel
temperature (T= 21 K) and large negative MR below 3T, reported
earlier for the polycrystals, are reproducible even in single crystals. Such
features are generally uncharacteristic of Gd alloys. In addition, we also
found interesting features in other data, e.g., two-step first-order-like
metamagnetic transitions for the magnetic field along [0001] direction. The
alloy exhibits anisotropy in all these properties, though Gd is a S-state ion.Comment: RevTeX, 5 pages, 6 encapsulated postscript figures; scheduled to be
published in Phy. Rev. B (01 November 1999, B1
Pion parameters in nuclear medium from chiral perturbation theory and virial expansion
We consider two methods to find the effective parameters of the pion
traversing a nuclear medium. One is the first order chiral perturbation
theoretic evaluation of the pion pole contribution to the two-point function of
the axial-vector current. The other is the exact, first order virial expansion
of the pion self-energy. We find that, although the results of chiral
perturbation theory are not valid at normal nuclear density, those from the
virial expansion may be reliable at such density. The latter predicts both the
mass-shift and the in-medium decay width of the pion to be small, of about a
few MeV.Comment: 9 Pages RevTex, 3 eps figure
Magnetic behaviour of Eu_2CuSi_3: Large negative magnetoresistance above Curie temperature
We report here the results of magnetic susceptibility,
electrical-resistivity, magnetoresistance (MR), heat-capacity and ^{151}Eu
Mossbauer effect measurements on the compound, Eu_2CuSi_3, crystallizing in an
AlB_2-derived hexagonal structure. The results establish that Eu ions are
divalent, undergoing long-range ferromagnetic-ordering below (T_C=) 37 K. An
interesting observation is that the sign of MR is negative even at temperatures
close to 3T_C, with increasing magnitude with decreasing temperature exhibiting
a peak at T_C. This observation, being made for a Cu containing magnetic
rare-earth compound for the first time, is of relevance to the field of
collosal magnetoresistance.Comment: To appear in PRB, RevTex, 4 pages text + 6 psFigs. Related to our
earlier work on Gd systems (see cond-mat/9811382, cond-mat/9811387,
cond-mat/9812069, cond-mat/9812365
On the nucleon self-energy in nuclear matter
We consider the nucleon self-energy in nuclear matter in the absence of Pauli
blocking. It is evaluated using the partial-wave analysis of scattering
data. Our results are compared with that of a realistic calculation to estimate
the effect of this blocking. It is also possible to use our results as a check
on the realistic calculations.Comment: 6 pages, 2 figure
From natural numbers to numbers and curves in nature – I
The interconnection between number theory, algebra, geometry
and calculus is shown through Fibonacci sequence,
golden section and logarithmic spiral. In this two-part
article, we discuss how simple growth models based on
these entities may be used to explain numbers and curves
abundantly found in nature
From natural numbers to numbers and curves in nature - II
In this second part of the article we discuss how simple growth models based on Fibbonachi numbers, golden section, logarithmic spirals, etc. can explain frequently occuring numbers and curves in living objects. Such mathematical modelling techniques are becoming quite popular in the study of pattern formation in nature
Optimization problems in elementary geometry
Optimization, a principle of nature and engineering design, in real life problems is normally achieved by using numerical methods. In this article we concentrate on some optimization problems in elementary geometry and Newtonian mechanics. These include Heron's problem, Fermat's principle, Brachistochrone problems, Fagano's problem, geodesics on the surface of a parallelepiped, Fermat/Steiner problem, Kakeya problem and the isoperimetric problem. Some of these are very old and historically famous problems, a few of which are still unresolved. Close connection between Euclidean geometry and Newtonian mechanics is revealed by the methods used to solve some of these problems. Examples are included to show how some problems of analysis or algebra can be solved by using the results of these geometrical optimization problems
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