Electron-nucleus scalar-pseudoscalar interaction in PbF: Z-vector study in the relativistic coupled-cluster framework

The scalar-pseudoscalar interaction constant of PbF in its ground state electronic configuration is calculated using the Z-vector method in the relativistic coupled-cluster framework. The precise calculated value is very important to set upper bound limit on P,T-odd scalar-pseudoscalar interaction constant, k_s, from the experimentally observed P,T-odd frequency shift. Further, the ratio of the effective electric field to the scalar-pseudoscalar interaction constant is also calculated which is required to get an independent upper bound limit of electric dipole moment of electron, d_e, and k_s and how these (d_e and k_s) are interrelated is also presented here.Comment: 6 pages, 1 figure

Assessment of Emission Reduction and Fuel Savings using Ship Speed Optimization in Realistic Weather Conditions

In this work, our objective is to quantify emission reductions using speed optimization considering a realistic ship route and a broad range of weather conditions. Two representative bulk carriers have been selected for the analysis. An optimization algorithm has been used to minimize voyage fuel consumption while completing the voyage on or before the expected arrival time. A constraint on engine power has been used for realistic estimates of achievable ship speeds in different weather conditions considering the available engine power. Multiple voyages at different ship speeds and in different seasons have been simulated with and without speed optimization to observe the effect of these factors on emission reduction. The effect of wind and waves on engine power has been considered by calculating wind and wave resistance along with propeller efficiency as a function of advance coefficients. Up to 11% reduction in fuel consumption was obtained by optimizing speed as compared to the constant speed profile. It was observed that a significant amount of fuel could be saved especially in seasons with a higher likelihood of heavy weather. Variation in fuel savings in different seasons has been discussed in the context of metocean conditions experienced in the selected months. Additionally, higher fuel savings were obtained for lower average ship speed which means speed reduction combined with speed optimization has greater potential to reduce emissions. Realistic estimates of fuel savings in a range of operating conditions presented in this paper would help ship owners, operators, and policymakers to assess the benefits of speed optimization among other technologies to decarbonize the shipping industry

Temperature-dependent transformation of the magnetic excitation spectrum on approaching superconductivity in Fe1-x (Ni/Cu)x Te0.5 Se0.5

Spin excitations are one of the top candidates for mediating electron pairing in unconventional superconductors. Their coupling to superconductivity is evident in a large number of systems, by the observation of an abrupt redistribution of magnetic spectral weight at the superconducting transition temperature, Tc, for energies comparable to the superconducting gap. Here we report inelastic neutron scattering measurements on Fe-based superconductors, Fe1-x (Ni/Cu)x Te0.5 Se0.5, that emphasize an additional signature. The overall shape of the low energy magnetic dispersion changes from two incommensurate vertical columns at T >> Tc to a distinctly different U-shaped dispersion at low temperature. Importantly, this spectral reconstruction is apparent for temperature up to ~3Tc. If the magnetic excitations are involved in the pairing mechanism, their surprising modification on the approach to Tc demonstrates that strong interactions are involved

Totally Regio- and Stereoselective Synthesis of (E)-3-Arylidene-3,4- Dihydro-2H-1,4-benzoxazines Under Palladium Catalyst

A new, one-pot palladium catalyzed reaction has been developed for the general synthesis of (E)-3-arylidene- 3,4-dihydro-2H-1,4-benzoxazines at room temperature. The reaction procedure tolerates various functional groups. The method is characterized by regio- and stereoselectivity, operational simplicity, mild reaction conditions, and short reaction time

Ancient Schwannoma of Ansa Cervicalis: A Rare Clinical Entity and Review of the Literature

Ancient schwannoma is an uncommon variant of schwannoma, a benign tumor arising from the nerve sheath. It is reported to arise from any nerves except optic and olfactory. However, only six cases of ancient schwannomas arising from ansa cervicalis nerve have been reported to date in English literature. Proper preoperative evaluation is necessary to rule out other causes of neck mass such as thyroid lesions, lymphadenopathy, and carotid body tumor. We report a case of ancient schwannoma arising from the ansa cervicalis nerve. The origin of the lesion from ansa cervicalis was confirmed by intraoperative finding. Postoperative histopathological examination revealed degenerative changes including pleomorphism, cellular atypia, large nuclei with prominent nucleoli, and paucity of mitotic figures. Periphery of the mass showed nuclear palisading with characteristic verocay bodies. Immunohistochemical evaluation for S-100 showed diffuse positivity of the tumor cells, thereby confirming the diagnosis of schwannoma. We consider that schwannoma of cervical region can have origin from any nerve and should try to identify the origin pre- and intraoperatively. The postoperative complications depend on the nerve of origin and the precision of the surgery performed