Technical Study of Judith with the Head of Holofernes from Nizhny Tagil Museum of Fine Arts. New Materials for Attribution

We performed a technological investigation of Judith with the Head of Holofernes (a copy of Cristofano Allori’s work) from the Nizhny Tagil Museum of Fine Arts to clarify the painting’s attribution. According to the current attribution, the copy was created in the 17th century Italy. Pigment analysis using X-ray fluorescence spectroscopy and scanning electron microscopy with energy dispersive spectroscopy was undertaken in order to provide indicators of the approximate date of the Nizhny Tagil copy. The analysis results – supplemented with evidence from UV-imaging and micro-imaging, radiographic examination and studies of the paintings’ support, ground and paint layers – agree with the existing attribution but do not necessarily confirm it. Comparison of the technical characteristics of the Nizhny Tagil Judith with the techniques of Western and Russian painting allows us to extend the dating. In addition, certain fragments of the painting were examined to provide insight into specifics of differences between the copy and the original, which turned out to be mainly the results of previous restorations. Keywords: 17th century Italian painting, painting technique, canvas, pigments, ground, X-ray fluorescence, scanning electron microscopy, x-radiograph, cross-section

Crisis Management and Communication Strategies: RUSAL’s Case

No company is immune to crisis situations, an affirmation which, despite its triviality, is undeniably true. However, from the early 2014, such statement may have become even more true to Russian corporations, as the annexation of the Crimean Peninsula gave start to rounds of economic sanctions that are still perpetrated today. Such measures, which were initiated in response to the Kremlin’s political maneuvers, have hit a number of Russian companies, and increased the degree of uncertainty in which they have to operate, as they see economic restriction’s impact not only on the business activity tangible factors—i.e., economic rewards, service, and performance—but also on intangible factors—i.e., image and reputation—as well. Crises are integral parts of all world systems, unfortunately. While they are a theoretically well-understood issue, in practice, crises are perceived as a very painful phenomenon. A crisis can be compared to riding a roller coaster. First, as we gain speed and climb up the tracks we are filled with a sense of joy and delight. These feelings are quickly replaced with anticipation, panic, and fear as the roller coaster plunges into the “abyss.

Power-over-Fiber with Simultaneous Transmission of Optical Carrier for a High Frequency Analog Signal over Standard Single-Mode Fiber

Efficient simultaneous transmission of light with a power of more than 2 W at a wavelength of 976 nm and an optical carrier for transmitting a high-frequency analog signal at a wavelength of 1550 nm over a distance of 1 km over a standard single-mode fiber was experimentally demonstrated. Electrical power up to 350 mW (5 V, 70 mA) was obtained from a multi-junction silicon photocell, resulting in the optical transmission efficiency of about 70% and a photocell efficiency of 25%. The power transmission did not affect the transmission of the high frequency analog signal. Key broadband analog transmission characteristics such as noise figure (NF SFDR3 > 117 dB/Hz2/3) were achieved and were close to the fundamental shot noise limit. This approach is promising for powering a remote antenna unit in optical fronthaul architecture

Electronic System of Remote Optical Control of LiNbO3 Mach-Zehnder Modulator Operating Point

A system for integrated optical LiNbO3 Mach–Zehnder modulator operating point remote control and stabilization was developed. It consisted of a conventional telecom photodiode and a passive electronic circuit at the bias input of the modulator. Light from an amplitude-modulated laser was used to remotely set the output voltage of the electronic circuit at the bias input of the Mach–Zehnder modulator. Information regarding the current operating point that had been provided with feedback system implementation was taken from DC values of high frequency photodetector currents. Efficient remote control of the modulator operating point over 1 km of a single-mode optical fiber, which multiplexes an optical carrier at 1550 nm and a low frequency control signal with a peak power of 2 mW at 1310 nm, was demonstrated. The results could be of interest for antenna remoting, radio-over-fiber (RoF) technology, and other applications with broadband optical transmission from remote sources in a distributed network

Features of the Molecular Structure and Luminescence of Rare-Earth Metal Complexes with Perfluorinated (Benzothiazolyl)phenolate Ligands

A set of Sc, Nd, Sm, Eu, Ho, Gd, Er, Yb complexes with perfluorinated 2-(benzothiazol-2-yl)phenolate ligands Ln(SONF)3(DME) were synthesized by the reactions of silylamides Ln[N(SiMe3)2]3 with phenol H(SONF). The structure of the initial phenol, Sc, and Er complexes was established using X-ray analysis, which revealed that the obtained compounds are mononuclear, in contrast to the binuclear non-fluorinated analogues [Ln(SON)3]2 synthesized earlier. All the obtained complexes, both in solid state and in tetrahydrofuran (THF) solutions, upon excitation by light with λex 395 or 405 nm show intense luminance of the ligands at 440–470 nm. The Eu complex also exhibits weak metal-centered emission in the visible region, while the derivatives of Sm luminesces both in the visible and in the infrared region, and Nd, Er, and Yb complexes emit in the near IR (NIR) region of high intensity. DFT (density functional theory) calculation revealed that energy of frontier orbitals of the fluorinated complexes is lower than that of the non-fluorinated counterparts. The level of highest occupied molecular orbital (HOMO) decreases to a greater extent than the lowest occupied molecular orbital (LUMO) level