Mass–yield distributions of fission products from photo-fission of natPb induced by 50–70 MeV bremsstrahlung

The mass–yield distributions of various fission products have been determined in the 50-, 60- and 70-MeV end point bremsstrahlung induced fission of ^natPb using off-line γ-ray spectrometric technique in the electron linac at Pohang Accelerator Laboratory, Korea. The mass–yield distributions are symmetric with average mass of 102.34, 102.25 and 102.03 and FWHM of 21, 22 and 23 mass unit, respectively. From the present data and literature data in the 50–85 MeV bremsstrahlung induced fission of ²⁰⁹Bi the following observations were obtained: (i) The average masses of the yield distributions in the 50–85 MeV bremsstrahlung induced fission of ^natPb and ²⁰⁹Bi are around 102.25 ± 0.25 and 103 ± 0.5, respectively. (ii) The FWHM of the mass–yield distributions increases from about 21 mass units at 50 MeV to 23 mass units at 70–85 MeV, which is explained from the point of increase in multi-chance fission probability with increasing excitation energy. (iii) Within the bremsstrahlung energy range of 50–85 MeV, the role of nuclear structure effect in the mass–yield distribution was observed in the photo-fission of ²⁰⁹Bi, whereas it was not seen in case of ^natPb. This may be due to the presence of so many isotopes in ^natPb unlike mono-isotopic ²⁰⁹Bi.     

Analogue of Aharonov-Bohm effect in spin gauge theory

We predict the possibility of observing analogue of the Aharonov-Bohm effect due to long range interaction between spins originating in the framework of spin gauge theory developed earlier. The effect is predicted for both electrons (fermions) and photons. Appropriate experimental set-ups are suggested.     

Correlations of fission fragment angular momentum with collective and intrinsic degrees of freedom

In the present work angular momenta of the fragments corresponding to¹³²I^m,g have been deduced from the radiochemically determined independent isomeric yield ratios and statistical model based analysis in neutron induced fission of²³⁵U,²³⁹Pu and²⁴⁵Cm and spontaneous fission of²⁵²Cf. These data along with similar data on¹³⁴I, reported earlier from this laboratory, bring out the effects of deformed 66n and spherical 82n shells on fragment angular momentum showing also an inverse correlation of the latter with elemental yields. Quantitative estimates of fragment scission point deformation and the coefficient of change of fragment angular momentum with kinetic/excitation energy have been deduced and are seen to be in good agreement with the expected theoretical estimates.     

Models of information aggregation in financial markets: a review

This article reviews static and dynamic models of information aggregation in the literature. It highlights the key assumptions these models make, the results they obtain and the issues that still need to be explored to further our understanding of information aggregation in financial markets.     

Investigation on Impurity Profiling and Degradation Behavior of WCK 771

Chromatographia - WCK 771 is a novel antibacterial drug recently launched in India for the treatment of acute bacterial skin and skin structure infections (ABSSSI). This report describes...     

Simultaneous determination of novel β-lactamase inhibitor WCK 4234 and Meropenem in dog plasma by LC–MS/MS and its application to preclinical pharmacokinetic study

A precise and accurate liquid chromatography–tandem mass spectrometric (LC–MS/MS) bioanalytical method has been developed and validated for the simultaneous quantification of WCK 4234 and meropenem (MEM) in dog plasma. Protein precipitation using acetonitrile was employed as a sample preparation approach. Cefepime was used as an internal standard. The developed method was selective, sensitive (limit of quantification, 0.075 μg/ml for both drugs), accurate (recovery > 90%), precise (CV < 10%) and linear (r² ≥ 0.99, concentration range 0.075–120 μg/ml for both analytes). The developed method was successfully applied for the determination of both drugs in plasma to assess the pharmacokinetics in beagle dogs. WCK 4234 + MEM in a 1:1 ratio at 15 + 15 and 30 + 30 mg/kg doses were administered by the intravenous route. The mean plasma concentration and area under the concentration–time curve of WCK 4234 ranged from 38.3 to 77.4 μg/ml and from 47.8 to 77.1 μg h/ml, respectively, and the values for MEM ranged from 52.2 to 115.3 μg/ml and 70.5 to 133.6 μg h/ml respectively. The elimination half-life of WCK 4234 and MEM was around 0.8 h.     

Underwater Dynamic Collapse of Sandwich Composite Structures

Experimental Mechanics - An experimental investigation is conducted to study the mechanics of underwater implosion of cylindrical bonded sandwich composite shells. Sandwich structures comprised of...     

Simultaneous visual detection of pulse chirp and temporal asymmetry in ultrashort laser pulses using analysis of unbalanced interferometric correlation envelope (ICE) functions

A simple method that uses envelope functions of unbalanced interferometric (auto/cross) correlation signals has been presented for simultaneous visual detection of pulse chirp and asymmetry, without direction-of-time ambiguity in ultrashort laser pulses. The ambiguity issues of unbalanced interferometric correlation envelope (ICE) difference signals have been studied. It is found that unbalanced ICE difference signals are visually different corresponding to practically indistinguishable unbalanced interferometric autocorrelation (IAC) signals for a distinct symmetric–asymmetric pulse pair with identical intensity autocorrelation and power spectra. The theoretical analysis of ICE signals is supported by experimental unbalanced IAC signals obtained using 200 fs laser pulses from a cw mode-locked Nd:phosphate laser oscillator. PACS 42.65.Re; 42.50.Hz; 07.60.Ly     

A single reagent radioimmunoassay for thyroxine in blood samples absorbed on filter paper for mass screening of neonatal hypothyroidism

A single reagent radioimmunoassay for thyroxine in blood samples absorbed on filter paper for the mass screening of neonatal hypothyroidism is described. Blood samples were collected by pricking the heel of newborn babies (3 days old) and pressing Whatman 3 filter paper against the wound. 6 mm diameter blood spots were punched out at the time of assay and incubated with 0.4 ml of a preincubated antigen-antibody complex for six hours at 37 °C. 1 ml of 22% polyethylene glycol is used for the precipitation of antigen-antibody complex. The assay has a sensitivity of 2.2 ng/ml. 500 samples collected from newborns were analyzed in the assay and gave a mean of 117.6±31.9 ng/ml.