3 research outputs found
Studying the Dynamical Properties of 20 Nearby Galaxy Clusters
Using SDSS-DR7, we construct a sample of 42382 galaxies with redshifts in the
region of 20 galaxy clusters. Using two successive iterative methods, the
adaptive kernel method and the spherical infall model, we obtained 3396
galaxies as members belonging to the studied sample. The 2D projected map for
the distribution of the clusters members is introduced using the 2D adaptive
kernel method to get the clusters centers. The cumulative surface number
density profile for each cluster is fitted well with the generalized King
model. The core radii of the clusters' sample are found to vary from 0.18 Mpc
\mbox{h}^{-1} (A1459) to 0.47 Mpc \mbox{h}^{-1} (A2670) with mean value of
0.295 Mpc \mbox{h}^{-1}.
The infall velocity profile is determined using two different models, Yahil
approximation and Praton model. Yahil approximation is matched with the
distribution of galaxies only in the outskirts (infall regions) of many
clusters of the sample, while it is not matched with the distribution within
the inner core of the clusters. Both Yahil approximation and Praton model are
matched together in the infall region for about 9 clusters in the sample but
they are completely unmatched for the clusters characterized by high central
density. For these cluster, Yahil approximation is not matched with the
distribution of galaxies, while Praton model can describe well the infall
pattern of such clusters.Comment: 16 pages, 8 figure
Yield Optimization and Supercritical CO2 Extraction of Essential Oil from Jasmine Flower
Supercritical fluid extraction (SFE) is an innovation that permits extraction of an extensive variety of different chemical composition from the plant grids. Extraction of essential oil from Jasmine flower was tentatively carried out using the supercritical CO2 technique. The effect of extraction parameters which include pressure (100–300 bar) and temperature (300–350 K) on the oil recovery was explored. The extraction process was optimized using the response surface methodology (RSM). At the SFE optimal conditions, the chemical compositions of the extracted oil were examined using gas chromatography-mass spectrometry (GC-MS) analysis. The obtained result reflected that the optimal yield of oil from Jasmine flower was 12.18% mg oil extracted/100 g dry flower, which was achieved through an SFE optimal conditions of pressure at 200 bar and extraction temperature at 325 K. A total number of six chemical compounds were tentatively identified in the Jasmine flower extracted oil at the optimal SFE conditions