Massless scalar fields and topological black holes

The exact static solutions in the higher dimensional Einstein-Maxwell-Klein- Gordon theory are investigated. With the help of the methods developed for the effective dilaton type gauge gravity models in two dimensions, we find new spherically and hyperbolically symmetric solutions which generalize the four dimensional configurations of Dereli-Eris. We show that, like in four dimensions, the non-trivial scalar field yields, in general, a naked singularity. The new solutions are compared with the higher dimensional Brans-Dicke black hole type solutions.Comment: 15 pages, LATEX, no figures. (To appear in Phys. Rev. D

Gas seepage and seismogenic structures along the North Anatolian Fault in the eastern Sea of Marmara

We carried out a combined geophysical and gas-geochemical survey on an active fault strand along the North Anatolian Fault (NAF) system in the Gulf of İzmit (eastern Sea of Marmara), providing for the first time in this area data on the distribution of methane (CH4) and other gases dissolved in the bottom seawater, as well as the CH4isotopic composition. Based on high-resolution morphobathymetric data and chirp-sonar seismic reflection profiles we selected three areas with different tectonic features associated to the NAF system, where we performed visual and instrumental seafloor inspections, including in situ measurements of dissolved CH4, and sampling of the bottom water. Starting from background values of 2–10 nM, methane concentration in the bottom seawater increases abruptly up to 20 nM over the main NAF trace. CH4 concentration peaks up to ∼120 nM were detected above mounds related probably to gas and fluids expulsion. Methane is microbial (δ13CCH4: −67.3 and −76‰ versus VPDB), and was found mainly associated with pre-Holocene deposits topped by a 10–20 m thick draping of marine mud. The correlation between tectonic structures and gas-seepages at the seafloor suggests that the NAF in the Gulf of İzmit could represent a key site for long-term combined monitoring of fluid exhalations and seismicity to assess their potential as earthquake precursors

Dressing with Control: using integrability to generate desired solutions to Einstein's equations

21 pages, no figures21 pages, no figures21 pages, no figures21 pages, no figuresMotivated by integrability of the sine-Gordon equation, we investigate a technique for constructing desired solutions to Einstein's equations by combining a dressing technique with a control-theory approach. After reviewing classical integrability, we recall two well-known Killing field reductions of Einstein's equations, unify them using a harmonic map formulation, and state two results on the integrability of the equations and solvability of the dressing system. The resulting algorithm is then combined with an asymptotic analysis to produce constraints on the degrees of freedom arising in the solution-generation mechanism. The approach is carried out explicitly for the Einstein vacuum equations. Applications of the technique to other geometric field theories are also discussed

V444 Cygni X-ray and polarimetric variability: radiative and coriolis forces shape the wind collision region

We present results from a study of the eclipsing, colliding-wind binary V444 Cyg that uses a combination of X-ray and optical spectropolarimetric methods to describe the 3D nature of the shock and wind structure within the system. We have created the most complete X-ray light curve of V444 Cyg to date using 40 ks of new data from Swift, and 200 ks of new and archived XMM-Newton observations. In addition, we have characterized the intrinsic, polarimetric phase-dependent behavior of the strongest optical emission lines using data obtained with the University of Wisconsin's Half-Wave Spectropolarimeter. We have detected evidence of the Coriolis distortion of the wind-wind collision in the X-ray regime, which manifests itself through asymmetric behavior around the eclipses in the system's X-ray light curves. The large opening angle of the X-ray emitting region, as well as its location (i.e. the WN wind does not collide with the O star, but rather its wind) are evidence of radiative braking/inhibition occurring within the system. Additionally, the polarimetric results show evidence of the cavity the wind-wind collision region carves out of the Wolf-Rayet star's wind

Comparison of the effects of fentanyl and sufentanyl on haemodynamy and recovery parameters during TIVA in craniotomy [Kraniyotomilerde total i·ntravenöz anestezi uygulamasinda kullanilan sufentanil ve fentanilin hemodinami ve derlenmeye etkilerinin karşilaştirilmasi]

Aim: We aimed to compare the effects of fentanyl and sufentanyl on haemodynamy and recovery parameters during TIVA in patients undergoing craniotomy. Materials and Methods: Thirty ASA I-II patients aged between 18 to 60 years who underwent elective craniotomy were randomly divided into two groups. Anesthesia induction was provided by intravenous atropine 0.1 mg, kg-1, propofol 2-3 mg kg-1, vecuronium 0.1 mg kg -1 in both groups. 2 µg kg-1 fentanyl was administered intravenously to the patients in fentanyl group, 1 µg kg-1 iv sufentanyl was given in sufentanyl group during anesthesia induction. Anaesthesia was maintained with % 50 O2 + air and 5-7 mg kg-1 propofol infusion in both groups with additional sufentanyl infusion at the rate of 0.3 pg kg-1 h-1 in the sufentanyl group and 1 µg kg-1 h-1 fentanyl in the fentanyl group. Haemodynamic variables were recorded during anesthesia till 240 min after extubation, including just before induction, before and after intubation, before and after pin holder insertion, before surgical incision and after surgical incision, Results: In fentanyl group when compared with sufentanyl group, mean arterial blood pressures were significantly higher following intubation (p=0.001), pin holder insertion (p=0.001) and surgical incision (p=0.020). In addition in fentanyl group mean arterial blood pressures increased significantly, both after intubation (p=0.001) and extubation (p=0.023) when compared with previous values. In fentanyl group, heart rates increased significantly, both after intubation (p=0.013) and extubation (p=0.017) while in sufentanyl group heart rates increased significantly only after extubation (p=0.038) when compared with previous values. Time needed for eye opening (P=0.009) and hand gripping (p=0.019) were significantly shorter in sufentanyl group. Conclusion: We conclude that in patients undergoing craniotomy, sufentanyl administrated at doses used for TIVA is more effective in depressing the intraoperative haemodynamic response than fentanyl and provides more rapid recovery time than fentanyl

Rapid, sensitive, and reusable detection of glucose by highly monodisperse nickel nanoparticles decorated functionalized multi-walled carbon nanotubes

PubMed ID: 28129630Addressed herein, functionalized multi-walled carbon nanotube (MWCNT) supported highly monodisperse nickel nanoparticles modified on glassy carbon electrode (Ni@f-MWCNT/GCE) were synthesized through microwave assisted method and examined for non-enzymatic glucose sensing in ionic liquids by cyclic voltammetry and chronoamperometry. The results of Ni@f-MWCNT/GCE electrode were compared with Ni NPs/GCE electrode and the results revealed that f-MWCNTs increased the electrocatalytic properties of Ni nanoparticles regarding glucose oxidation. They also demonstrated a good linear span of 0.05–12.0 mM and a detection boundary of 0.021 µM. Specifically, in the amperometric signal of the electrodes after 200th cycles, no major change was observed. This non-enzymatic glucose sensor presents one of the record electrocatalytic activity, stability and response towards glucose under the optimized situations. As a result, prepared novel Ni@f-MWCNT/GCE was utilized to detect glucose in real serum species. © 2017 Elsevier B.V.2016-75, 2014-05 Academy of Health SciencesThis research was supported by Dumlupinar University (2014-05, 2016-75). The partial supports by Science Academy and FABED are gratefully acknowledged