Spectral Clustering for Optical Confirmation and Redshift Estimation of X-ray Selected Galaxy Cluster Candidates in the SDSS Stripe 82

We develop a galaxy cluster finding algorithm based on spectral clustering technique to identify optical counterparts and estimate optical redshifts for X-ray selected cluster candidates. As an application, we run our algorithm on a sample of X-ray cluster candidates selected from the third XMM-Newton serendipitous source catalog (3XMM-DR5) that are located in the Stripe 82 of the Sloan Digital Sky Survey (SDSS). Our method works on galaxies described in the color-magnitude feature space. We begin by examining 45 galaxy clusters with published spectroscopic redshifts in the range of 0.1 to 0.8 with a median of 0.36. As a result, we are able to identify their optical counterparts and estimate their photometric redshifts, which have a typical accuracy of 0.025 and agree with the published ones. Then, we investigate another 40 X-ray cluster candidates (from the same cluster survey) with no redshift information in the literature and found that 12 candidates are considered as galaxy clusters in the redshift range from 0.29 to 0.76 with a median of 0.57. These systems are newly discovered clusters in X-rays and optical data. Among them 7 clusters have spectroscopic redshifts for at least one member galaxy.Comment: 15 pages, 7 figures, 3 tables, 1 appendix, Accepted by Journal of "Astronomy and Computing

The 3XMM/SDSS Stripe 82 Galaxy Cluster Survey: Cluster catalogue and discovery of two merging cluster candidates

We present a galaxy cluster survey based on XMM-Newton observations that are located in Stripe 82 of the Sloan Digital Sky Survey (SDSS). The survey covers an area of 11.25 deg$^2$. The X-ray cluster candidates were selected as serendipitously extended detected sources from the third XMM-Newton serendipitous source catalogue (3XMM-DR5). A cross-correlation of the candidate list that comprises 94 objects with recently published X-ray and optically selected cluster catalogues provided optical confirmations and redshift estimates for about half of the candidate sample. We present a catalogue of X-ray cluster candidates previously known in X-ray and/or optical bands from the matched catalogues or NED. The catalogue consists of 54 systems with redshift measurements in the range of 0.05-1.19 with a median of 0.36. Of these, 45 clusters have spectroscopic confirmations as stated in the matched catalogues. We spectroscopically confirmed another 6 clusters from the available spectroscopic redshifts in the SDSS-DR12. The cluster catalogue includes 17 newly X-ray discovered clusters, while the remainder were detected in previous XMM-Newton and/or ROSAT cluster surveys. Based on the available redshifts and fluxes given in the 3XMM-DR5 catalogue, we estimated the X-ray luminosities and masses for the cluster sample. We also present the list of the remaining X-ray cluster candidates (40 objects) that have no redshift information yet in the literature. Of these candidates, 25 sources are considered as distant cluster candidates beyond a redshift of 0.6. We also searched for galaxy cluster mergers in our cluster sample and found two strong candidates for newly discovered cluster mergers at redshifts of 0.11 and 0.26. The X-ray and optical properties of these systems are presented.Comment: 17 pages, 12 figures, accepted for publication in A&A, revised version after language editin

Practical Provably Secure Multi-node Communication

We present a practical and provably-secure multimode communication scheme in the presence of a passive eavesdropper. The scheme is based on a random scheduling approach that hides the identity of the transmitter from the eavesdropper. This random scheduling leads to ambiguity at the eavesdropper with regard to the origin of the transmitted frame. We present the details of the technique and analyze it to quantify the secrecy-fairness-overhead trade-off. Implementation of the scheme over Crossbow Telosb motes, equipped with CC2420 radio chips, shows that the scheme can achieve significant secrecy gain with vanishing outage probability. In addition, it has significant overhead advantage over direct extensions to two-nodes schemes. The technique also has the advantage of allowing inactive nodes to leverage sleep mode to further save energy.Comment: Proceedings of the IEEE International Conference on Computing, Networking and Communications (ICNC 2014

Design and synthesis of new thiophene derivatives together with their antitumor evaluations

A series of new thiophene derivatives (3a,b) have been prepared by the reaction of acetylacetone with either cyanoacetanilide or 2-cyano-N-(p-tolyl)acetamide and elemental sulfur in the presence of triethylamine as basic catalyst. The two synthesized compounds were used to further synthesize new thiophene derivatives. The structures of all the newly synthesized products have been established on the basis of analytical and spectral data. The antitumor activity of the newly thiophene derivatives was evaluated against six human cancer cell lines, namely gastric cancer (NUGC), colon cancer (DLD1), liver cancer (HA22T and HEPG2), nasopharyngeal carcinoma (HONE1), breast cancer (MCF) and normal fibroblast cells (WI38)

Weathering of Outdoor Beech Wood and Methods of Conservation

The aim of this study is to highlight the appearance of deterioration resulting from weathering effects on the beech wood used in the ornamentation of wooden window grilles (Mashrabiya) in the Mosque of Prince Hassan, in Akhmim-Sohag and in the Mosque of Khawand Asalbay, in Fayoum, Egypt. This wood was accurately examined with a Digital microscope and Scanning Electron Microscope (SEM) to diagnose the deterioration processes on the surface of the wood. Fourier transform infrared (FTIR) was used to identify the changes in the main components of the beech wood resulting from weathering factors. The chromatic change of the beech wood surface was measured by spectrophotometer and the results were calculated by using the CIE-L*a*b* system. Results showed the physical and chemical changes that had occurred in the degraded beech wood. The results helped to develop a treatment plan using already experimented materials that do not harm the wooden artifacts.Lo scopo di questo studio è quello di evidenziare l'aspetto del deterioramento derivante dagli effetti degli agenti atmosferici sul legno di faggio utilizzato nell'ornamento delle grate delle finestre in legno (Mashrabiya) nella “Moschea del principe Hassan”, Akhmim-Sohag e nella “Moschea di Khawand Asalbay”, Fayoum, Egitto. Questo legno è stato accuratamente esaminato con un microscopio digitale e un microscopio elettronico a scansione (SEM) per diagnosticare i processi di deterioramento sulla superficie del legno. L'infrarosso in trasformata di Fourier (FTIR) è stato utilizzato per identificare i cambiamenti nei componenti principali del legno di faggio dovuti a fattori di alterazione. Il cambiamento cromatico della superficie in legno di faggio è stato misurato mediante spettrofotometro utilizzando il sistema CIE-L*a*b*. I risultati mostrano i cambiamenti fisici e chimici verificatisi nel legno di faggio degradato. Tali risultati hanno contribuito a sviluppare un piano di trattamento utilizzando materiali già sperimentati che non danneggiano i manufatti in legno

CFD study of thermal effect on Power-law fluid in rotating annular flow

Drilling in oil and gas industry is a crucial and precarious process. Inaccurate estimation or expectation of any of the parameters interfering in this process can lead to catastrophic results if not handled carefully and in proper timing. One of the main parameters is the drilling fluid, which is used throughout the whole drilling procedure for numerous functions. The drilling fluid is tested under normal atmospheric temperature. However in the drilling process the fluid is exposed to high temperature that can impact the drilling fluid properties and flow behavior. Adding to that the rotation of the drill string impact which can change the dynamic viscosity of the fluid. As more high temperature high pressure wells are being drilled the need to better understand the impact of high temperature in the fluid annular flow became necessary. In this study we tried to understand and investigate the effect of both temperature and rotation on the properties of the drilling fluid and on the flow behavior in a concentric annuli. The scope and methodology of this research involved Computational Fluid Dynamics (CFD) approach, with ANSYS-CFX (in ANSYS 15) as the analysis system, where a CFD model with an optimum mesh size was created and validated against previous experimental data. The fluid was modelled using Power Law rheology

A study of the bovine vagina as related to reproductive performance

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