Working group report: Neutrino and astroparticle physics

This is the report of neutrino and astroparticle physics working group at WHEPP-7. Discussions and work on CP violation in long baseline neutrino experiments, ultra high energy neutrinos, supernova neutrinos and water Cerenkov detectors are discussed.     

Dislocation mediated melting of silicon-metal interfaces

It is known that the silicide formation between silicon and transition as well as noble metals occurs at 0.3–0.4 of the melting temperature of silicon. It is proposed that the chemical reaction is preceded by an interfacial melting process due to dislocation generation via the Kösterlitz-Thouless mechanism. The overall softening of the Debye temperature at the interface leads to the low temperature chemical reaction observed. A softening mechanism due to screening of the silicon lattice by the metal overlayer is suggested.     

In Vitro Anticancer Activity of Methanolic Extract of Justicia adhatoda Leaves with Special Emphasis on Human Breast Cancer Cell Line

Natural products are being targeted as alternative anticancer agents due to their non-toxic and safe nature. The present study was conducted to explore the in vitro anticancer potential of Justicia adhatoda (J. adhatoda) leaf extract. The methanolic leaf extract was prepared, and the phytochemicals and antioxidant potential were determined by LCMS analysis and DPPH radical scavenging assay, respectively. A docking study performed with five major alkaloidal phytoconstituents showed that they had a good binding affinity towards the active site of NF-κB. Cell viability assay was carried out in five different cell lines, and the extract exhibited the highest cytotoxicity in MCF-7, a breast cancer cell line. Extract-treated cells showed a significant increase in nitric oxide and reactive oxygen species production. Cell cycle analysis showed an arrest in cell growth at the Sub-G0 phase. The extract successfully inhibited cell migration and colony formation and altered mitochondrial membrane potential. The activities of superoxide dismutase and glutathione were also found to decrease in a dose-dependent manner. The percentage of apoptotic cells was found to increase in a dose-dependent manner in MCF-7 cells. The expressions of caspase-3, Bax, and cleaved-PARP were increased in extract-treated cells. An increase in the expression of NF-κB was found in the cytoplasm in extract-treated cells. J. adhatoda leaf extract showed a potential anticancer effect in MCF-7 cells.     

On the solution of time-fractional dynamical model of Brusselator reaction-diffusion system arising in chemical reactions

Fractional Brusselator reaction-diffusion system (BRDS) is used for modeling of specific chemical reaction-diffusion processes. It may be noted that numerous models in nonlinear science are defined by fractional differential equations (FDEs) in which an unknown function appears under the operation of a fractional-order derivative. Even though many researchers have studied the applicability and practicality of this model, the analytical approach of this model is rarely found in the literature. In this investigation, a novel semi-analytical technique called fractional reduced differential transform method (FRDTM) has been applied to solve the present model, which is characterized by the time-fractional derivative (FD). Obtained outcomes are compared with the solution of other existing methods for a particular case. Also, the convergence analysis of this model has been studied here.     

Insulator-metal transition in thin films of ferrite Fe3O4

Insulator-metal transition in Fe₃O₄ is analysed on the basis of electron-electron correlation of nearest neighbour sites. A double time Zubarev Green function technique is used. It is shown that up to 120 °K system stays in a localised state and then goes into the band-state. The band-state completely disorders itself at 300 °K. Conductivity and thin film data are briefly analysed.     

B and collider physics: Working group report

This report summarises the work done during WHEPP-6 (Institute of Mathematical Sciences, Chennai, India, Jan 3–15, 2000) in Working group on ‘B and collider physics’.     

In vivo molecular evaluation of guinea pig skin incisions healing after surgical suture and laser tissue welding using Raman spectroscopy

The healing process in guinea pig skin following surgical incisions was evaluated at the molecular level, in vivo, by the use of Raman spectroscopy. After the incisions were closed either by suturing or by laser tissue welding (LTW), differences in the respective Raman spectra were identified. The study determined that the ratio of the Raman peaks of the amide III (1247 cm⁻¹) band to a peak at 1326 cm⁻¹ (the superposition of elastin and keratin bands) can be used to evaluate the progression of wound healing. Conformational changes in the amide I band (1633–1682 cm⁻¹) and spectrum changes in the range of 1450–1520 cm⁻¹ were observed in LTW and sutured skin. The stages of the healing process of the guinea pig skin following LTW and suturing were evaluated by Raman spectroscopy, using histopathology as the gold standard. LTW skin demonstrated better healing than sutured skin, exhibiting minimal hyperkeratosis, minimal collagen deposition, near-normal surface contour, and minimal loss of dermal appendages. A wavelet decomposition–reconstruction baseline correction algorithm was employed to remove the fluorescence wing from the Raman spectra.     

Free vibration of nonhomogeneous Timoshenko nanobeams

Free vibration of nonhomogeneous nanobeams based on nonlocal Timoshenko beam theory has been studied using boundary characteristic orthogonal polynomial functions in the Rayleigh–Ritz method. Orthogonal polynomial functions satisfying essential boundary conditions have been generated with the help of Gram–Schmidt Process. Nonhomogeneity of nanobeams is assumed to arise due to linear and quadratic variations in Young’s modulus and density of the nanobeams with space coordinate. The lowest three frequency parameters of nanobeams subjected to different boundary conditions have been computed for various values of nonhomogeneous parameters to demonstrate the effect of each parameters on the frequency parameters. A detailed investigation has been reported for all the possible cases of variations in Young’s modulus and density to analyze the numerical results for different scaling effect parameters and four types of boundary conditions. Present results are compared with the results in special cases and are found to be in good agreement.