Miniature Non-thermal Plasma Induced Cell Cycle Arrest and Apoptosis in Lung Carcinoma Cells

Plasma Chemistry and Plasma Processing - Non-thermal plasma has been a promising new cancer treatment modality in plasma oncology field. It generates extracellular and intracellular reactive...     

Influence of 120 MeV S9+ ion irradiation on structural,optical and morphological properties of zirconium oxide thin films deposited by RF sputtering

The calibrated and controlled swift heavy ions (SHI) beam irradiation generate defects which can cause modifications in various properties of the materials such as structural, optical, magnetic, morphological, and chemical etc. The passage of ion through the target material causes the nuclear energy losses ($S_n$) and electronic energy losses ($S_e$). The $S_e$ dominates over $S_n$ in SHI irradiation. In the present study, ZrO₂ thin films were grown on silicon and glass substrate by using RF sputtering deposition technique. For the purpose of modifications induced by swift heavy ions, these films were irradiated by a 120 MeV S⁹⁺ ion beam of 1 pnA current, with varying ion fluences from 5E12 to 1E13 ions/cm², using the tandem accelerator at the Inter University Accelerator Center (IUAC), New Delhi, India. The X-ray diffraction (XRD) patterns confirmed the formation of monoclinic and tetragonal phases and it was observed that XRD peaks intensity increased up to the fluence of 5E12 ions/cm² followed by opposite behavior at higher fluences. Atomic force microscope (AFM) study revealed the increased surface roughness after SHI irradiation. In addition to it, the formation of electronic transition states in optical band gap region and enhancement of absorption edge was observed from UV-visible spectroscopy (UV-Vis) results due to which direct band gap energy value decreased from those of un-irradiated samples. Photoluminescence (PL) broad emission spectra were determined using the excitation wavelength at 290 nm with the prominent peak at 415 nm which can be ascribed to Zr vacancies due to band edge emission as a result of free-exciton recombination. Rutherford backscattering spectrometry (RBS) technique was used for depth profiling and elemental composition in zirconia thin films. The expected role of electronic energy loss during ion irradiation is to modify the properties of the material has been discussed.     

Workshop on gravitational waves and relativistic astrophysics

Discussions related to gravitational wave experiments viz. LIGO and LISA as well as to observations of supermassive black holes dominated the workshop sessions on gravitational waves and relativistic astrophysics in the ICGC-2004. A summary of seven papers that were presented in these workshop sessions has been provided in this article.     

Scheduling Three-Operation Jobs in a Two-Machine Flow Shop to Minimize Makespan

This paper considers a variant of the classical problem of minimizing makespan in a two-machine flow shop. In this variant, each job has three operations, where the first operation must be performed on the first machine, the second operation can be performed on either machine but cannot be preempted, and the third operation must be performed on the second machine. The NP-hard nature of the problem motivates the design and analysis of approximation algorithms. It is shown that a schedule in which the operations are sequenced arbitrarily, but without inserted machine idle time, has a worst-case performance ratio of 2. Also, an algorithm that constructs four schedules and selects the best is shown to have a worst-case performance ratio of 3/2. A polynomial time approximation scheme (PTAS) is also presented.     

Criterion for Invertibility of Endomorphisms and Test Rank of Metabelian Products of Abelian Groups

Let G be a finitely generated torsion-free group, which is a metabelian product of Abelian groups. We establish a criterion for endomorphisms satisfying some extra restriction to be invertible in G. Test sets for IA-endomorphisms of G are described and its test rank computed.     

Quantum theory of coherent anti-Stokes Raman scattering in an inhomogeneously broadened gaseous system

A quantum-statistical treatment of coherert anti-Stokes Raman scatterirg in a gaseous system is presented. The atomic system is described by two energy levels. Both the atomic system and the radiation fields are quartized. The effects of atomic motion ard the detuning are incorporated into the analysis. The equations of motion describing the photor statistics of pump, Stokes and anti-Stokes fields are obtained considering the process as a two-step one. The time-evolution of average photon number and the second-order coherence of the anti-Stokes fields for different initial distributions are studied. The occurrence of antibunching is investigated.     

Evaluation of surface roughness by an electro-optical sensor

An electro-optical sensor reported in earlier publications has been used for surface roughness measurements of machined grooved surfaces. Although the signal trace of a light spot on a rough surface produced by a difference photo-diode detector is different from the surface profile its standard deviation has been found to be related to the surface roughness. A new parameter, the equivalent grating constant, which defines surface roughness can be determined by making use of the minimum value of the standard deviation.