On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory simultaneously observed a transient gravitational-wave signal. The signal sweeps upwards in frequency from 35 to 250 Hz with a peak gravitational-wave strain of 1.0×10(-21). It matches the waveform predicted by general relativity for the inspiral and merger of a pair of black holes and the ringdown of the resulting single black hole. The signal was observed with a matched-filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203,000 years, equivalent to a significance greater than 5.1σ. The source lies at a luminosity distance of 410(-180)(+160)  Mpc corresponding to a redshift z=0.09(-0.04)(+0.03). In the source frame, the initial black hole masses are 36(-4)(+5)M⊙ and 29(-4)(+4)M⊙, and the final black hole mass is 62(-4)(+4)M⊙, with 3.0(-0.5)(+0.5)M⊙c(2) radiated in gravitational waves. All uncertainties define 90% credible intervals. These observations demonstrate the existence of binary stellar-mass black hole systems. This is the first direct detection of gravitational waves and the first observation of a binary black hole merger.

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The Observation of Gravitational Waves from a Binary Black Hole Merger

KEGG(Kyoto Encyclopedia of Genes and Genomes)〔和文〕 (特集 ゲノム医学の現在と未来--基礎と臨床) -- (データベース)

비만아 부모의 돌봄 경험: q 방법론

A key challenge in the field of electrochemical carbon dioxide reduction is the design of catalytic materials featuring high product selectivity, stability, and a composition of earth-abundant elements. In this work, we introduce thin films of nanosized metal-organic frameworks (MOFs) as atomically defined and nanoscopic materials that function as catalysts for the efficient and selective reduction of carbon dioxide to carbon monoxide in aqueous electrolytes. Detailed examination of a cobalt-porphyrin MOF, Al2(OH)2TCPP-Co (TCPP-H2 = 4,4',4″,4‴-(porphyrin-5,10,15,20-tetrayl)tetrabenzoate) revealed a selectivity for CO production in excess of 76% and stability over 7 h with a per-site turnover number (TON) of 1400. In situ spectroelectrochemical measurements provided insights into the cobalt oxidation state during the course of reaction and showed that the majority of catalytic centers in this MOF are redox-accessible where Co(II) is reduced to Co(I) during catalysis.

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Metal−Organic Frameworks for Electrocatalytic Reduction of Carbon Dioxide

This paper reviews the best known techniques using circular dichroism spectroscopy such as conventional circular dichroism (i.e. electronic circular dichroism), magnetic circular dichroisms (magnetic vibrational circular dichroism, x-ray magnetic circular dichroism), fluorescence detected circular dichroism, near-infrared circular dichroism, vibrational circular dichroism, Fourier transform infrared circular dichroism, high pressure liquid chromatography circular dichroism, stopped-flow circular dichroism, and synchrotron radiation circular dichroism. Also, we have described here the most important applications of circular dichroism spectroscopy in structural biochemistry and nanoscience.

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Circular Dichroism Techniques: Biomolecular and Nanostructural Analyses- A Review

A black brane solution to Gauss–Bonnet massive gravity is introduced. In the context of AdS/CFT correspondence, the viscosity to entropy ratio is found by the Green–Kubo formula. The result indicates a violation of the well-known KSS bound, as expected in a higher derivative theory. Setting mass zero gives back the known viscosity to entropy ratio dependent on the Gauss–Bonnet coupling, while without the Gauss–Bonnet term, a nonzero mass parameter does not contribute to the ratio which saturates the bound of

Hydrodynamics of a black brane in Gauss–Bonnet massive gravity

Silicon photonic platforms are of significant interest for a variety of applications that operate in the mid-infrared regime. However, the realization of efficient mid-IR modulators, key components in any integrated optics platform, is still a challenging topic. Here, an ultra-compact high-speed hybrid Si/VO2 modulator operating at a mid-IR wavelength of 3.8 μm is presented. Electrical properties of graphene are employed to achieve a reversible insulating-metal phase transition in VO2 by electrical actuation. The thermal characteristics of graphene are employed to improve the response time of the VO2 phase transition through speed up heating and dissipation processes, thus enhancing the modulation speed. Optical and thermal simulations show an extinction ratio of 4.4 dB/μm, an insertion loss of 0.1 dB/μm, and high modulation speed of 23 ns. A larger modulation depth as high as 10 dB/μm can be achieved at the cost of lower modulation speed.

Mid-infrared hybrid Si/VO2 modulator electrically driven by graphene electrodes

A black brane solution to a Gauss-Bonnet massive gravity is introduced. In the context of AdS/CFT correspondence, the viscosity to entropy ratio is found by the Green-Kubo formula. The result indicates violation of the well-known KSS bound as expected in a higher derivative theory. Setting mass zero gives back the known viscosity to entropy ratio dependent on the Gauss-Bonnet coupling, while without Gauss-Bonnet term, a nonzero mass parameter doesn't contribute to the ratio which saturates the bound of $1/4\pi$.

Hydrodynamics of a Black Brane in Gauss-Bonnet Massive Gravity

In this paper, we introduced the black brane solution in Rastall theory and in the context of massive gravity. The ratio of shear viscosity to entropy density is calculated for this solution. Our result shows that the KSS bound violates for this theory.

Black Brane Solution in Rastall AdS Massive Gravity and Viscosity Bound

Following previous study about AdS-Schwarzschild black holes minimally coupled to a cloud of strings in the context of massive gravity (Ghanaatian et al. in Effects of the external string cloud on the Van der Waals like behavior and efficiency of AdS-Schwarzschild black hole in massive gravity, arXiv:1906.00369 [hep-th]) and inspired by strong connection between Gauss–Bonnet Gravity and heterotic string theory, in this paper, we first take into account the Gauss–Bonnet term and we study thermodynamics and critical behavior of these black holes in the extended phase space. The effects of Gauss–Bonnet, massive, and string cloud parameters on the criticality of these black holes has been investigated. It can be seen that the Gauss–Bonnet and massive parameters have opposite effects on the criticality and phase transition of the solutions. We also observe that the increase in the value of the string cloud parameter above a critical value, eliminates the van der Waals like behavior of these solutions. Also, the Joule–Thomson effect is not observed. Then we examine thermal stability of these black holes in canonical ensemble by calculating the heat capacity. In addition, we explore critical behavior in extended phase space by employing heat capacity and consequently, we observe that the results are in agreement with the previous results from the usual method in Sect. 3.

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Mehdi Sadeghi

Papers

Hydrodynamics of a black brane in Gauss–Bonnet massive gravity

Mid-infrared hybrid Si/VO2 modulator electrically driven by graphene electrodes

Hydrodynamics of a Black Brane in Gauss-Bonnet Massive Gravity

Black Brane Solution in Rastall AdS Massive Gravity and Viscosity Bound

Critical behavior of AdS Gauss–Bonnet massive black holes in the presence of external string cloud