Reconstruction of dielectric constants of multi-layered optical fibers using propagation constants measurements

We present new method for the numerical reconstruction of the variable refractive index of multi-layered circular weakly guiding dielectric waveguides using the measurements of the propagation constants of their eigenwaves. Our numerical examples show stable reconstruction of the dielectric permittivity function $\varepsilon$ for random noise level using these measurements

Numerical linear algebra: Theory and applications

© Springer International Publishing AG 2017. All rights reserved. This book combines a solid theoretical background in linear algebra with practical algorithms for numerical solution of linear algebra problems. Developed from a number of courses taught repeatedly by the authors, the material covers topics like matrix algebra, theory for linear systems of equations, spectral theory, vector and matrix norms combined with main direct and iterative numerical methods, least squares problems, and eigenproblems. Numerical algorithms illustrated by computer programs written in MATLAB® are also provided as supplementary material on SpringerLink to give the reader a better understanding of professional numerical software for the solution of real-life problems. Perfect for a one- or two-semester course on numerical linear algebra, matrix computation, and large sparse matrices, this text will interest students at the advanced undergraduate or graduate level

Reconstruction of dielectric constants of core and cladding of optical fibers using propagation constants measurements

© 2014 E. M. Karchevskii et al. We present new numerical methods for the solution of inverse spectral problem to determine the dielectric constants of core and cladding in optical fibers. These methods use measurements of propagation constants. Our algorithms are based on approximate solution of a nonlinear nonselfadjoint eigenvalue problem for a system of weakly singular integral equations. We study three inverse problems and prove that they are well posed. Our numerical results indicate good accuracy of new algorithms

INDUSTRIAL SAFETY IN THE PRODUCTION OF RUBBER

Russian industry of synthetic rubber, is one of the most competitive and occupies a prominent place in the global petrochemical industry. However, the company production of synthetic rubber are among the most hazardous industrial facilities. The main operational risks are to fire and explosion hazards of raw materials used. Accidents in such establishments can damage not only the equipment, materials or buildings, but also cause serious environmental and economic consequences for the region. For the prevention of accidents, mitigation and elimination of losses, it is necessary to apply a set of measures aimed at the management and control of industrial safety. The legal basis of industrial safety in the Russian Federation is the Federal Law № 116-FZ dated 21.07.97 "On industrial safety of hazardous production facilities." Industrial Safety at work an important part of its normal functioning. The most important condition of industrial safety of hazardous production facilities is the examination of industrial safety. Federal rules and regulations in the field of industrial safety "rules of examination of industrial safety", approved by Order of RTN on November 14, 2013 N 538 established: the procedure of examination of industrial safety requirements for the design of expert opinions and requirements for experts

PROVIDING INDUSTRIAL SAFETY IN THE DESIGN OF CHEMICAL FACILITIES

Designing of chemical destination requires developers’ particular, careful approach, as malfunctions are dangerous for the whole area in which the facility is located. Efficient and uninterrupted operation of a chemical entity assumes certain tasks, and at the design stage, and during the construction, reconstruction, repair, and maintenance. When designing a crucial question: placing equipment in the technological scheme (nature and the order and connection of separate devices); determine the input parameters of raw materials; establishment of technological parameters of the system; determine the structural characteristics of the devices of the system; selection of process parameters in devices that affect the speed of the process, output and product quality. The main document containing the requirements of industrial safety, chemical and other dangerous objects is the Federal Law of July 21, 1997 № 116-FZ "On industrial safety of hazardous production facilities", as amended on December 31, 2014. It defines and regulates the framework for ensuring the safe operation of hazardous production facilities. The most important part in the development and design of hazardous chemicals is the examination of industrial safety, which is held on the basis of the principles of independence, objectivity, comprehensiveness and completeness of the research carried out by using modern science and technology. Design of chemical facilities is a complex, multifactorial and time-consuming process, which should be regarded as a series of socio-organizational and engineering stages. It is a systematic approach to solving design problems and control of all stages of the life cycle of chemical facilities will provide a high level of safe operation of industrial facilities

Towards sustainable development through bridging digital penetration gaps

The aim of the article is to study the impact of the digital environment on the economic conditions of economic entities, as well as to assess the gaps between economic development, changes in social relations and environmental well-being. It is proved that gaps in digital penetration can cause the deepening of existing inequalities and risks: digital inequality, social inequality, inequality in the appropriation of benefits, environmental risks. Approaches to assessing the impact of digital artifacts on the environment (in the context of the concept of "circular economy") and sustainable development of the economic system are investigate

Structural determinants of PINK1 topology and dual subcellular distribution

<p>Abstract</p> <p>Background</p> <p>PINK1 is a mitochondria-targeted kinase that constitutively localizes to both the mitochondria and the cytosol. The mechanism of how PINK1 achieves cytosolic localization following mitochondrial processing remains unknown. Understanding PINK1 subcellular localization will give us insights into PINK1 functions and how mutations in PINK1 lead to Parkinson's disease. We asked how the mitochondrial localization signal, the transmembrane domain, and the kinase domain participate in PINK1 localization.</p> <p>Results</p> <p>We confirmed that PINK1 mitochondrial targeting signal is responsible for mitochondrial localization. Once inside the mitochondria, we found that both PINK1 transmembrane and kinase domain are important for membrane tethering and cytosolic-facing topology. We also showed that PINK1 dual subcellular distribution requires both Hsp90 interaction with the kinase domain and the proteolysis at a cleavage site downstream of the transmembrane domain because removal of this cleavage site completely abolished cytosolic PINK1. In addition, the disruption of the Hsp90-PINK1 interaction increased mitochondrial PINK1 level.</p> <p>Conclusion</p> <p>Together, we believe that once PINK1 enters the mitochondria, PINK1 adopts a tethered topology because the transmembrane domain and the kinase domain prevent PINK1 forward movement into the mitochondria. Subsequent proteolysis downstream of the transmembrane domain then releases PINK1 for retrograde movement while PINK1 kinase domain interacts with Hsp90 chaperone. The significance of this dual localization could mean that PINK1 has compartmental-specific functions.</p

Testing the FMR1 Promoter for Mosaicism in DNA Methylation among CpG Sites, Strands, and Cells in FMR1-Expressing Males with Fragile X Syndrome

Variability among individuals in the severity of fragile X syndrome (FXS) is influenced by epigenetic methylation mosaicism, which may also be common in other complex disorders. The epigenetic signal of dense promoter DNA methylation is usually associated with gene silencing, as was initially reported for FMR1 alleles in individuals with FXS. A paradox arose when significant levels of FMR1 mRNA were reported for some males with FXS who had been reported to have predominately methylated alleles. We have used hairpin-bisufite PCR, validated with molecular batch-stamps and barcodes, to collect and assess double-stranded DNA methylation patterns from these previously studied males. These patterns enable us to distinguish among three possible forms of methylation mosaicism, any one of which could explain FMR1 expression in these males. Our data indicate that cryptic inter-cell mosaicism in DNA methylation can account for the presence of FMR1 mRNA in some individuals with FXS