Proton and alpha evaporation spectra in low energy 12C and 16O induced reactions

Proton and alpha particle spectra have been measured in the ¹²C+⁹³Nb and ¹²C+⁵⁸Ni reactions at E(¹²C)=40 and 50 MeV and in the ¹⁶O + ⁹³Nb reaction at E(¹⁶O) =75 MeV. The spectra are compared with the statistical model calculations. The shapes of the calculated spectra are in agreement with experimental data except for the alpha spectrum in the ¹²C + ⁹³Nb reaction at 40 MeV. The observed evaporation bump is at ∼2 MeV lower energy compared to the calculated one. This discrepancy could imply alpha particle emission from a deformed configuration before compound nucleus formation at this near Coulomb barrier beam energy.     

Study of fiber optic sugar sensor

Over the last two decades, the fiber optic technology has passed through many analytical stages. Some commercially available fiber optic sensors, though in a small way, are being used for automation in mechanical and industrial environments. They are also used for instrumentation and controls. In the present work, an intensity-modulated intrinsic fiber optic sugar sensor is presented. This type of sensor, with slight modification, can be used for on-line determination of the concentration of sugar content in sugarcane juice in sugar industry. In the present set-up, a plastic fiber made of polymethylmethacrylate is used. A portion of the cladding (1 cm, 2 cm, 3 cm) at the mid-point along the length of the fiber is removed. This portion is immersed in sugar solution of known concentration and refractive index. At one end of the fiber an 850 nm source is used and at the other end a power meter is connected. By varying the concentration of sugar solution, the output power is noted. These studies are made due to the change in refractive index of the fluid. The device was found to be very sensitive which is free from EMI and shock hazards, stable and repeatable and they can be remotely interfaced with a computer to give on-line measurements and thus become useful for application in sugar industries.     

Observation of inter-grain Josephson effects in Y-Ba-Cu-O samples

Josephson effects have been observed in bulk samples of Y-Ba-Cu-O. The magnitude of the zero-voltage current is found to change systematically with externally applied small magnetic fields of a few mG. It is also found to vary when samples are irradiated with microwaves. These observations suggest the presence of inter-grain Josephson junctions.     

Corrigendum to the paper ``Adjoining an Order Unit to a Matrix Ordered Space'

An error has been detected (and also corrected) in Theorem 2.8 of the paper entitled “Adjoining an Order Unit to a Matrix Ordered Space” (Positivity, (2005)9: 207–223; DOI ). Accordingly, some of the results of the paper have been modified. Also, a notion of C*-matricially, Riesz normed spaces has been introduced.     

Collapse of square and rectangular tubes in transverse loading

Summary Analysis of the in plane lateral collapse of square and rectangular cross-section tubes is presented by considering the out-of-straightness of horizontal and vertical arms, corner radius, friction between the platens and the deforming specimen and instability of vertical arms. Results of collapse load for tubes of aluminium and mild steel, thus computed, are presented for some typical tube geometrics, and influence thereon of various parameters considered is discussed. Experiments were conducted wherein tubes of square and rectangular cross-sections of both the materials were laterally compressed between two parallel platens in an Instron machine. The observed collapse loads compare very well with the corresponding computed values.

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Kollaps von vertikal belasteten Rohren mit quadratischem und rechteckigem Querschmitt

Übersicht Der Kollaps von Rohren mit quadratischem und rechteckigem Querschnitt, welche senkrecht zur Achse belastet werden, wird untersucht, wobei schiefe Vertikal- und Horizontalstege, gerundete Profilecken, Reibung zwischen Belastungsplatten und Rohr sowie die Stabilität der Vertikalstege brücksichtigt werden. Die Kollapslast wird für Aluminium und Weichstahl und einige typische Rohrgeometrien ermittelt und der Einfluß verschiedener Parameter wird untersucht. Die Experimente wurden auf einer Instron-Maschine durchgeführt, wobei Rohre mit quadratischem und rechteckigem Querschnitt aus beiden Werkstoffen zwischen zwei parallelen Platten quer zur Achse komprimiert wurden. Es konnte eine gute Übereinstimmung zwischen den Resultaten aus Experiment und Rechnung festgestellt werden.

     

Environment-induced decoherence II. Effect of decoherence on Bell''s inequality for an EPR pair

According to Bell's theorem, the degree of correlation between spatially separated measurements on a quantum system is limited by certain inequalities if one assumes the condition of locality. Quantum mechanics predicts that this limit can be exceeded, making it nonlocal. We analyse the effect of an environment modelled by a fluctuating magnetic field on the quantum correlations in an EPR singlet as seen in the Bell inequality. We show that in an EPR setup, the system goes from the usual ‘violation’ of Bell's inequality to a ‘non-violation’ for times larger than a characteristic time scale which is related to the parameters of the fluctuating field. We also look at these inequalities as a function of the spatial separation between the EPR pair.