Mass function and dynamical study of the open clusters Berkeley 24 and Czernik 27

We present a $UBVI$ photometric study of the open clusters Berkeley 24 (Be 24) and Czernik 27 (Cz 27). The radii of the clusters are determined as 2\farcm7 and 2\farcm3 for Be 24 and Cz 27, respectively. We use the Gaia Data Release 2 (GDR2) catalogue to estimate the mean proper motions for the clusters. We found the mean proper motion of Be 24 as $0.35\pm0.06$ mas yr$^{-1}$ and $1.20\pm0.08$ mas yr$^{-1}$ in right ascension and declination for Be 24 and $-0.52\pm0.05$ mas yr$^{-1}$ and $-1.30\pm0.05$ mas yr$^{-1}$ for Cz 27. We used probable cluster members selected from proper motion data for the estimation of fundamental parameters. We infer reddenings $E(B-V)$ = $0.45\pm0.05$ mag and $0.15\pm0.05$ mag for the two clusters. Analysis of extinction curves towards the two clusters show that both have normal interstellar extinction laws in the optical as well as in the near-IR band. From the ultraviolet excess measurement, we derive metallicities of [Fe/H]= $-0.025\pm0.01$ dex and $-0.042\pm0.01$ dex for the clusters Be 24 and Cz 27, respectively. The distances, as determined from main sequence fitting, are $4.4\pm0.5$ kpc and $5.6\pm0.2$ kpc. The comparison of observed CMDs with $Z=0.01$ isochrones, leads to an age of $2.0\pm0.2$ Gyr and $0.6\pm0.1$ Gyr for Be 24 and Cz 27, respectively. In addition to this, we have also studied the mass function and dynamical state of these two clusters for the first time using probable cluster members. The mass function is derived after including the corrections for data incompleteness and field star contamination. Our analysis shows that both clusters are now dynamically relaxedComment: 16 pages including 8 tables. 22 figures. Accepted by MNRA

Evaluation of Daphnia magna as an indicator of Toxicity and Treatment efficacy of Municipal Sewage Treatment Plant

Performance evaluation of wastewater treatment plants (WWTPs) with special reference to toxicity reduction using Daphnia magna straus as test organism is very important to study the likely adverse effects of thetreated wastewater on the aquatic ecosystem of receiving waters and to detect common environmentally realistic concentrations of pollutants at different concentration levels and toxicity discriminatory ability to distinguish different degree of toxicity and toxic specificity of the compounds on target organisms. This test can be considered asuseful analytical tool for screening of chemical analysis and early warning system to monitor the different operational units of wastewater treatment plants. Interrelationship between COD, SS with respect to Daphnia toxicity (Gd) suggests that improvement of the toxicological quality of wastewater could be linked to the removal of both COD and suspended solids. Both the parameters (COD & SS) can serve as a regulatory tool in lieu of an explicit toxicological standard. An important feature of this work was to emphasize the significance of toxicity tests. It could help to reduceinfluent toxicity and thereby avoid impacting microorganisms’ population in activated sludge systems. This study shows the difference between using physico-chemical and biological criteria to define the quality or toxicity ofwastewater, making it clear that both methods are indispensable and complimentary and support the earlier view that Daphnia magna can serve as a valuable model for bio- monitoring of water pollution and for evaluation of the toxicity of an effluent and risk assessment in an aquatic body, as it is highly sensitive to pollutants

Bioassay evaluation of toxicity reduction in common effluent treatment plant

This paper investigates the utility and validity of bioassay toxicity testing using Daphnia magna straus as test organism for monitoring the common effluent treatment plant (CETP) receiving both industrial as well as domestic effluent. The average daphnia toxicity (Gd) at inlet, after primary settling tank (PST), secondary settling tank (SST) and tertiary treatment unit were reported as Gd-16, Gd-12, Gd-4 and Gd-1 respectively. However, a cumulative percentage removal in toxicity after PST, SST and tertiary treatment units was observed as 25%, 75% and 100%, respectively, during entire study period. It showed that a complete removal in daphnia toxicity (Gd) i.e.100% had been achieved only after tertiary treatment unit involving Dual Media Filters followed by activated carbon filters. Further attempts have been made to establish the relationship between key wastewater constituents i.e. Chemical Oxygen Demand (COD) and Suspended Solids (SS) with respects to daphnia toxicity (Gd). It was observed that COD and SS show a statistically significant correlation (r2) with daphnia toxicity (Gd) i.e. 0.89 and 0.81, respectively. Thus COD and SS can serve as a regulatory tool in lieu of an explicit toxicity standard (to check and improve the operational status of wastewatertreatment plants in time)

Nonlocal Equation of State in Anisotropic Static Fluid Spheres in General Relativity

We show that it is possible to obtain credible static anisotropic spherically symmetric matter configurations starting from known density profiles and satisfying a nonlocal equation of state. These particular types of equation of state describe, at a given point, the components of the corresponding energy-momentum tensor not only as a function at that point, but as a functional throughout the enclosed configuration. To establish the physical plausibility of the proposed family of solutions satisfying nonlocal equation of state, we study the constraints imposed by the junction and energy conditions on these bounded matter distributions. We also show that it is possible to obtain physically plausible static anisotropic spherically symmetric matter configurations, having nonlocal equations of state\textit{,}concerning the particular cases where the radial pressure vanishes and, other where the tangential pressures vanishes. The later very particular type of relativistic sphere with vanishing tangential stresses is inspired by some of the models proposed to describe extremely magnetized neutron stars (magnetars) during the transverse quantum collapse.Comment: 21 pages, 1 figure, minor changes in the text, references added, two new solutions studie

Static charged perfect fluid spheres in general relativity

Interior perfect fluid solutions for the Reissner-Nordstrom metric are studied on the basis of a new classification scheme. General formulas are found in many cases. Explicit new global solutions are given as illustrations. Known solutions are briefly reviewed.Comment: 23 pages, Revtex (galley), journal version, to appear in Phys.Rev.

Nuclear model developments in FLUKA for present and future applications

The FLUKAS code [1–3] is used in research laboratories all around the world for challenging applications spanning a very wide range of energies, projectiles and targets. FLUKAS is also extensively used for in hadrontherapy research studies and clinical planning systems. In this paper some of the recent developments in the FLUKAS nuclear physics models of relevance for very different application fields including medical physics are presented. A few examples are shown demonstrating the effectiveness of the upgraded code

Galaxy Counterparts of metal-rich Damped Lyman-alpha Absorbers - I: The case of the z=2.35 DLA towards Q2222-0946

We have initiated a survey using the newly commissioned X-shooter spectrograph to target candidate relatively metal-rich damped Lyman-alpha absorbers (DLAs). The spectral coverage of X-shooter allows us to search for not only Lyman-alpha emission, but also rest-frame optical emission lines. We have chosen DLAs where the strongest rest-frame optical lines ([OII], [OIII], Hbeta and Halpha) fall in the NIR atmospheric transmission bands. In this first paper resulting from the survey, we report on the discovery of the galaxy counterpart of the z_abs = 2.354 DLA towards the z=2.926 quasar Q2222$-0946. This DLA is amongst the most metal-rich z>2 DLAs studied so far at comparable redshifts and there is evidence for substantial depletion of refractory elements onto dust grains. We measure metallicities from ZnII, SiII, NiII, MnII and FeII of -0.46+/-0.07, -0.51+/-0.06, -0.85+/-0.06, -1.23+/-0.06, and -0.99+/-0.06, respectively. The galaxy is detected in the Lyman-alpha, [OIII] lambda4959,5007 Halpha emission lines at an impact parameter of about 0.8 arcsec (6 kpc at z_abs = 2.354). We infer a star-formation rate of 10 M_sun yr^-1, which is a lower limit due to the possibility of slit-loss. Compared to the recently determined Halpha luminosity function for z=2.2 galaxies the DLA-galaxy counterpart has a luminosity of L~0.1L^*_Halpha. The emission-line ratios are 4.0 (Lyalpha/Halpha) and 1.2 ([OIII]/Halpha). The Lyalpha line shows clear evidence for resonant scattering effects, namely an asymmetric, redshifted (relative to the systemic redshift) component and a much weaker blueshifted component. The fact that the blueshifted component is relatively weak indicates the presence of a galactic wind. The properties of the galaxy counterpart of this DLA is consistent with the prediction that metal-rich DLAs are associated with the most luminous of the DLA-galaxy counterparts.Comment: 9 pages, 7 figures. Accepted for publication in MNRA

Nuclear Skins and Halos in the Mean-Field Theory

Nuclei with large neutron-to-proton ratios have neutron skins, which manifest themselves in an excess of neutrons at distances greater than the radius of the proton distribution. In addition, some drip-line nuclei develop very extended halo structures. The neutron halo is a threshold effect; it appears when the valence neutrons occupy weakly bound orbits. In this study, nuclear skins and halos are analyzed within the self-consistent Skyrme-Hartree-Fock-Bogoliubov and relativistic Hartree-Bogoliubov theories for spherical shapes. It is demonstrated that skins, halos, and surface thickness can be analyzed in a model-independent way in terms of nucleonic density form factors. Such an analysis allows for defining a quantitative measure of the halo size. The systematic behavior of skins, halos, and surface thickness in even-even nuclei is discussed.Comment: 22 RevTeX pages, 22 EPS figures included, submitted to Physical Review

Structure and mass function of five intermediate/old open clusters

The UBVRI data of five northern open star clusters are used to study the mass function (MF), structure and dynamical state of these clusters. The clusters under discussion have ages ranging from ~0.6 to 5 Gyr. A comparison of the density profiles indicates that the evolution of the core of these clusters is almost the same, whereas the corona of the clusters are probably affected by the external environment and dynamical evolution. For the entire cluster region, the slope of the MF of three clusters (Be 64, Be 69 and King 5) has a value that agrees within the error with the Salpeter value, whereas King 7 and Be 20 show a steeper ($\Gamma = -2.02\pm 0.24$) and almost a flat MF respectively. We find that the slope of the MF of two clusters (King 5 and King 7) changes significantly from the inner region to the outer region, becoming steeper at larger radii. The dynamical relaxation time of the clusters under discussion is less than the age of the clusters, which indicates that all of these clusters are dynamically relaxed. Thus the observed mass segregation in three clusters can be attributed to the dynamical evolution of the clusters. The ratio of the clusters' present radius to the limiting radius (determined from the relation given by King [CITE]) can be representated by an exponent law