Nonsequential double ionization with few-cycle laser pulses

We investigate differential electron momentum distributions in nonsequential double ionization with linearly polarized, few-cycle pulses, using a classical model based on a laser-assisted inelastic (e(-),2e(-)) rescattering mechanism. These yields, as functions of the momentum components parallel to the laser polarization, are highly asymmetric and strongly influenced by the phase difference between the pulse envelope and its carrier oscillation, radically changing their sign around a critical phase. This behavior provides a powerful tool for absolute-phase measurements

Synopsis of marine prawn fishery of India for the third quarter of 1978

The data for the third quarter of 1978 is presented in this paper. The statewise and monthwise details of catch during the months of the quarter and the total catch of prawns for the quarter are summarized. Gearwise analysis of the catch, show that the prawn catch by shrimp trawlers increased from that of the previous quarter. In Kerala the trend of more prawn catch when the environmental features registered decrease in values noticed towards the end of last quarter continued in this quarter. In Kerala the trend of more prawn catch when the environmental features registered decrease in values noticed towards the end of last quarter continued in this quarter

Synopsis of marine prawn fishery of India for the second quarter of 1978

In continuation of the data on marine prawn fishery for the first quarter of 1978 presented in the September issue of the Marine Fisheries Information Service, Technical and Extension Series, the data for the second quarter of 1978 has been analysed

Synopsis of marine prawn fishery of India -1978

The details of the fishery for the last quarter of the year is dealt with first and then a general picture of the fishery for the whole year presented in this paper. The total catch figures for the previous quarters given earlier were provisional, whereas the final figures are used for the study of the fishery of the last quarter as well as the annual picture

High-order harmonic generation in a driven two-level atom: Periodic level crossings and three-step processes

We investigate high-order harmonic generation in closed systems using the two-level atom as a simplified model. By means of a windowed Fourier transform of the time-dependent dipole acceleration, we extract the main contributions to this process within a cycle of the driving field. We show that the patterns obtained can be understood by establishing a parallel between the two-level atom and the three-step model. In both models, high-order harmonic generation is a consequence of a three-step process, which involves either the continuum and the ground state, or the adiabatic states of the two-level Hamiltonian. The knowledge of this physical mechanism allows us to manipulate the adiabatic states, and consequently the harmonic spectra, by means of a bichromatic driving field. Furthermore, using scaling laws, we establish sharp criteria for the invariance of the physical quantities involved. Consequently, our results can be extended to a broader parameter range, as, for instance, those characteristic of solid-state systems in strong fields

The role of sexually dimorphic skin colour and shape in attractiveness of male faces

Evidence for attraction to sexually dimorphic features in male faces is inconsistent in the literature. Mixed results regarding facial masculinity and male attractiveness may arise partly from different influences of face shape and face colouration depending on whether colour was controlled. Recent research suggests that masculinity in face colour, namely darker skin, and femininity in shape are attractive in male faces. Here we examine the influence of sexual dimorphism in skin colour and face shape on attractiveness in 3 experiments. We allowed female participants to manipulate male and female face images along axes of sexual dimorphism in skin colour and/or shape in order to optimise attractiveness. Participants searching for the most attractive appearance chose to masculinise the colour of male faces more than the colour of female faces (although not reaching significance in Experiment 3; p = .16). We found a clear preference for feminine shape in male faces supporting predictions of recent research. These results help to clarify the influence of facial masculinity in women's attractiveness preferences

Theoretical and experimental studies of the bell-jar-top inductively coupled plasma

The present paper describes a systematic study of argon plasmas in a bell-jar inductively coupled plasma (ICP) source over the range of pressure 5-20 mtorr and power input 0.2-0.5 kW, Experimental measurements as well as results of numerical simulations are presented. The models used in the study include the well-known global balance model (or the global model) as well as a detailed two-dimensional (2-D) fluid model of the system, The global model is able to provide reasonably accurate values for the global electron temperature and plasma density, The 2-D model provides spatial distributions of various plasma parameters that make it possible to compare with data measured in the experiments, The experimental measurements were obtained using a tuned Langmuir double-probe technique to reduce the RF interference and obtain the light versus current (I-V) characteristics of the probe. Time-averaged electron temperature and plasma density were measured for various combinations of pressure and applied RF power, The predictions of the 2-D model were found to be in good qualitative agreement with measured data, It was found that the electron temperature distribution T-e was more or less uniform in the chamber, It was also seen that the electron temperature depends primarily on pressure, but is almost independent of the power input, except in the very low-pressure regime. The plasma density goes up almost linearly with the power input

Synopsis of marine prawn fishery of India –1980

During the year 1980 the total marine prawn production was estimated at 1,70,737 tonnes against 1,77,582 t in the previous year (table 1), showing a decrease of 6^45 t (3.85%). A comparative study of the production over the past few years indicates that the trend of slight decrease from the maximum in 1975 is maintained over these years. The decrease this year is mostly brought about by reduced catches in Maharashtra stat

Synopsis of marine prawn fishery of India for the first quarter of 1978

World fisheries statistics shows that India has reached the top rank in prawn production in 1973 and ever since ,this is being kept up. The trend in the prawn production over the past decade and a half shows that there has been steady increase of total landing up to 1973. The data from Cochin and Neendakara, two important landing centres for prawns in Kerala has been pooled together and presented. Data from another centre in kerala namely, Calicut also is given