High spin spectroscopy of Pd-100

The study of high spin states in Pd-100 has indicated the presence of both single particle and collective states. More than twenty new transitions have been observed. A substantial modification and extension of the existing level scheme is proposed, The negative parity states can be understood in terms of collective excitations of the core coupled to the 9(-) and 5(-) bandheads, which are probably based upon two quasineutron v(h(11/2),g(7/2)) and two quasiproton pi(g(9/2),p(1/2)) configurations respectively

Structure of the neutron deficient In-107

High spin states in the nucleus In-107 have been investigated using the reaction Zn-66(Sc-45,2p2n) at a beam energy of 162 MeV. Levels up to a spin 33/2 (h) over bar and an excitation energy 7 MeV have been established from gamma-gamma coincidence measurements. Two Delta I = 1 sequences have been observed, in addition to a large number of other states arising from single particle excitations. The configuration pi g(9/2)(-1)x nu h(11/2) coupled to neutrons in the d(5/2) and g(7/2) orbitals appears to have a dominant contribution to the observed negative parity states. [S0556-2813(98)07112-X]

Detailed high-spin spectroscopy and the search for the wobbling mode in Ta-171

High-spin states in Ta171 were populated in the Sn124(V51,4n) reaction at 228 MeV to search for evidence of stable triaxial deformation. Identification of a wobbling sequence based on the previously known πi13/2 structure would provide a unique signature for this rarely observed shape. No such sequence was identified in these data, which suggests that the island of triaxial strongly deformed bands may be smaller than once thought. However, over 200 new transitions and two new bands were placed in the level scheme and the sequence based on the πi13/2 orbital could be observed up to spin and parity Iπ=(101/2+). The relative excitations of all the sequences were determined and the ground state of Ta171 was found to have 5/2+ quantum numbers, contrary to previous reports. All of the previously known structures were extended to much higher spin and their high-frequency band crossings are interpreted within the framework of the cranked shell model

Observation of states beyond band termination in Er-156,Er-157,Er-158 and strongly deformed structures in Hf-173,Hf-174,Hf-175

High-spin terminating bands in heavy nuclei were first identified in nuclei around Er-158(90). While examples of terminating states have been identified in a number of erbium isotopes, almost nothing is known about the states lying beyond band termination. In the present work, the high-spin structure of Er-156,Er-157,Er-158 has been studied using the Gammasphere spectrometer. The subject of triaxial superdeformation and 'wobbling' modes in Lu nuclei has rightly attracted a great deal of attention. Very recently four strongly or superdeformed (SD) sequences have been observed in Hf-174, and cranking calculations using the Ultimate Cranker code predict that such structures may have significant triaxial deformation. We have performed two experiments in an attempt to verify the possible triaxial nature of these bands. A lifetime measurement was performed to confirm the large (and similar) deformation of the bands. In addition, a high-statistics, thin-target experiment took place to search for linking transitions between the SD bands, possible wobbling modes, and new SD band structures

Experimental investigation of heat transfer and pressure drop in a mini-channel shell and tube heat exchanger

This study experimentally investigated heat transfer and pressure drop on tube side of a mini-channel shell and tube heat exchanger (MC-STHE) prototype designed and manufactured using Kern method. Mini-channel copper tubes with an inner diameter of 2mm and a length of 240mm were used on the tube side of the MC-STHE. Baffles with a 25% baffle cut and a shell with an inner diameter of 30mm were used on the shell side. The Reynolds number on the tube side was changed from 1000 to 10,000 while that on the shell side was kept constant at 680. The experimental convective heat transfer coefficients and friction factors for the tube side were compared with correlations for macro-pipes commonly used in the literature. The experimental convective heat transfer coefficients were in good agreement with the Shah and Sieder-Tate correlations in the laminar region and in good agreement with the Petukhov, Hausen and Gnielinski correlations in the transition region while the experimental friction factors showed a similar tendency to the correlation modified by Shah. In addition, the Nusselt number and friction factor correlations have been proposed for use in designing similar MC-STHEs. The optimal operating range of Reynolds number for MC-STHEs is 4000<Re <5000 based on the Colburn factor while it is 4000<Re <6000 based on the flow area goodness factor