Ultrafast dynamics of neutral superexcited Oxygen: A direct measurement of the competition between autoionization and predissociation

Using ultrafast extreme ultraviolet pulses, we performed a direct measurement of the relaxation dynamics of neutral superexcited states corresponding to the nl\sigma_g(c^4\Sigma_u^-) Rydberg series of O_2. An XUV attosecond pulse train was used to create a temporally localized Rydberg wavepacket and the ensuing electronic and nuclear dynamics were probed using a time-delayed femtosecond near-infrared pulse. We investigated the competing predissociation and autoionization mechanisms for superexcited molecules and found that autoionization is dominant for the low n Rydberg states. We measured an autoionization lifetime of 92+/-6 fs and 180+/-10 fs for (5s,4d)\sigma_g and (6s,5d)\sigma_g Rydberg state groups respectively. We determine that the disputed neutral dissociation lifetime for the \nu=0 vibrational level of the Rydberg series is 1100+/-100fs.Comment: 5 pages, 4 figure

Possible Relevance of Odd Frequency Pairing to Heavy Fermion Superconductivity

What is the character of the gapless quasiparticles in heavy fermion superconductors (HFSC)? We discuss an odd-frequency pairing interpretation of HFSC which leads to a two component model for the quasiparticle excitations. In this picture, line zeroes of unpaired electrons may coexist with gapless surfaces of paired electrons, with vanishing spin and charge coherence factors

Phase diagram of UPt3_3 in the E1gE_{1g} model

The phase diagram of the unconventional superconductor UPt$_3$ is explained under the long-standing hypothesis that the pair wavefunction belongs to the $E_{1g}$ representation of the point group. The main objection to this theory has been that it disagrees with the experimental phase diagram when a field is applied along the c-axis. By a careful analysis of the free energy this objection is shown to be incorrect. This singlet theory also explains the unusual anisotropy in the upper critical field curves, often thought to indicate a triplet pair function.Comment: 11 pages, Revtex, 2 figures (uuencoded, gzip'ed Postscript

Pathological study of elective nephrectomies for a two year period

Background: Nephrectomies whether partial, total or radical are common surgical procedures these days with trauma being the most common cause of an emergency nephrectomy. The indications of elective nephrectomies vary with different age groups- malignancies being common in the elderly age group and non-neoplastic indications of nephrectomy may present in any age group. The present study was undertaken in view of the increasing elective nephrectomies in our area thus analyzing the common causes requiring nephrectomy as a treatment. The present study also aimed at determining the age and sex distribution of various renal lesions requiring a nephrectomy.Methods: It was a prospective study for a period of 2 years - January 2013 to December 2014. A total of 45 nephrectomies were included in the study. Detailed clinical, biochemical and imaging findings were taken into consideration before analyzing each case. Results: There was a male predominance(64.4%) and 26.6% of the cases were in the age group of 40-50 years. 95.5% of the nephrectomies were performed for a non-neoplastic indication. Involvement of the right and left kidney was almost equal in the study. Chronic pyelonephritis was the most common histopathological diagnosis(68.8%).Conclusion: Inflammatory causes more commonly required a nephrectomy in the study population.  Chronic calculous pyelonephritis was the most common underlying pathophysiology leading to a nonfunctioning kidney thus highlighting the early treatment of renal calculi.

Evolutionary Models in Software Engineering

Software development life cycle models play a vital role in developing a software application. This research deals with such advanced models which are the evolutionary models namely: incremental model, and spiral model. Both these models have their own advantages and disadvantages as well. The main objective of this research paper is to represent the two evolutionary modelsrsquo features and limitations

Heat Transport and the Nature of the Order Parameter in Superconducting UPt3UPt_3

Recent thermal conductivity data on the heavy fermion superconductor $UPt_3$ have been interpreted as offering support for an $E_{2u}$ model of the order parameter as opposed to an $E_{1g}$ model. In this paper, we analyze this issue from a theoretical standpoint including the detailed effects of Fermi surface and gap anisotropy. Our conclusion is that although current data put strong constraints on the gap anisotropy, they cannot definitively distinguish between these two models. Measurements on samples of varying quality could be decisive in this regard, however.Comment: 8 pages, revtex, 15 uunencoded postscript figure

Evidence for depinning of a Wigner crystal in Hg-Cd-Te

We report measurements of the nonlinear current-voltage characteristics on low-carrier-concentration n-type samples of Hg_(0.76)Cd_(0.24)Te at high magnetic fields and low temperatures. We find the onset of nonlinear conductivity occurs at applied electric fields of less than 1 mV/cm. The effect can be easily distinguished from sample heating and is consistent with collective transport produced by the sliding of a Wigner crystal pinned by disorder. We estimate a disorder-induced correlation length of tens of micrometers

Transport and the Order Parameter of Superconducting UPt3

We calculate the ultrasonic absorption and the thermal conductivity in the superconducting state of UPt$_{3}$ as functions of temperature and direction of propagation and polarization. Two leading candidates for the superconducting order parameter are considered: the $E_{1g}$ and $E_{2u}$ representations. Both can fit the data except for the ultrasonic absorption in the $A$ phase. To do that, it is necessary to suppose that the system has only a single domain, and that must be chosen as the most favorable one. However, the $E_{2u}$ theory requires fine-tuning of parameters to fit the low temperature thermal conductivity. Thus, transport data favor the $E_{1g}$ theory. Measurements of the thermal conductivity as a function of pressure at low temperature could help to further distinguish the two theories.Comment: 7 pages, 4 figure