173 research outputs found

    Integrable mixing of A_{n-1} type vertex models

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    Given a family of monodromy matrices {T_u; u=0,1,...,K-1} corresponding to integrable anisotropic vertex models of A_{(n_u)-1}-type, we build up a related mixed vertex model by means of glueing the lattices on which they are defined, in such a way that integrability property is preserved. Algebraically, the glueing process is implemented through one dimensional representations of rectangular matrix algebras A(R_p,R_q), namely, the `glueing matrices' zeta_u. Here R_n indicates the Yang-Baxter operator associated to the standard Hopf algebra deformation of the simple Lie algebra A_{n-1}. We show there exists a pseudovacuum subspace with respect to which algebraic Bethe ansatz can be applied. For each pseudovacuum vector we have a set of nested Bethe ansatz equations identical to the ones corresponding to an A_{m-1} quasi-periodic model, with m equal to the minimal range of involved glueing matrices.Comment: REVTeX 28 pages. Here we complete the proof of integrability for mixed vertex models as defined in the first versio

    Fluorescent Biomarker in Colorectal Cancer

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    Evaluation of time when evacuation of production site personnel begins. Ways to overcome the challenge on example of compressor shop

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    The article describes a method for estimating start time of evacuation of personnel working in a machine room of a gas compressor shop operated by a pipeline company. The method provides two options for estimating evacuation start time depending on reliability of a notification and evacuation control system. The first option implies that a notification and evacuation control system operates properly and is able to act as alarm in case of fire. In such sircumstances evacuation start time is estimated depending on psychophysical characteristics of humans, response time of a notification and evacuation control system and duration of operative actions. The second option implies that a notification and evacuation control system is out of order or not installed in a room. In this case employees are considered to detect fire visually assuming that a formed convective column of flue gases is the source of fire danger. Time taken by smoke to fill a convective column is considered as time needed for a person to detect fire. Psychophysical characteristics of humans and duration of operative actions are considered as well as in the first case. It is suggested that psychophysical characteristics of humans should be determined by results of computer-based psychodiagnostics. In order to estimate time needed for personnel to take prompt actions the article offers a network approach for evaluation of response speed of an operator. A method for estimating evacuation start time was developed taking into account current methodological issues in estimation of time characteristics of human actions during first stages of evacuation based on foreign and domestic research on human behavior in case of fire

    Magnetic and electric dipole moments of the H^3 Δ_1 state in ThO

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    The metastable H^3 Δ_1 state in the thorium monoxide (ThO) molecule is highly sensitive to the presence of a CP -violating permanent electric dipole moment of the electron (eEDM) [E. R. Meyer and J. L. Bohn, Phys. Rev. A 78, 010502 (2008)]. The magnetic dipole moment μ_H and the molecule-fixed electric dipole moment D_H of this state are measured in preparation for a search for the eEDM. The small magnetic moment μH=8.5(5)×10^(−3)μ_B displays the predicted cancellation of spin and orbital contributions in a ^3Δ_1 paramagnetic molecular state, providing a significant advantage for the suppression of magnetic field noise and related systematic effects in the eEDM search. In addition, the induced electric dipole moment is shown to be fully saturated in very modest electric fields (<10 V/cm). This feature is favorable for the suppression of many other potential systematic errors in the ThO eEDM search experiment

    Optically trapped Feshbach molecules of fermionic 161Dy and 40K

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    We report on the preparation of a pure ultracold sample of bosonic DyK Feshbach molecules, which are composed of the fermionic isotopes 161Dy and 40K. Employing a magnetic sweep across a resonance located near 7.3 G, we produce up to 5000 molecules at a temperature of about 50 nK. For purification from the remaining atoms, we apply a Stern-Gerlach technique based on magnetic levitation of the molecules in a very weak optical dipole trap. With the trapped molecules we finally reach a high phase-space density of about 0.1. We measure the magnetic field dependence of the molecular binding energy and the magnetic moment, refining our knowledge of the resonance parameters. We also demonstrate a peculiar anisotropic expansion effect observed when the molecules are released from the trap and expand freely in the magnetic levitation field. Moreover, we identify an important lifetime limitation that is imposed by the 1064-nm infrared trap light itself and not by inelastic collisions. The light-induced decay rate is found to be proportional to the trap light intensity and the closed-channel fraction of the Feshbach molecule. These observations suggest a one-photon coupling to electronically excited states to limit the lifetime and point to the prospect of loss suppression by optimizing the wavelength of the trapping light. Our results represent important insights and experimental steps on the way to achieve quantum-degenerate samples of DyK molecules and novel superfluids based on mass-imbalanced fermion mixtures

    Quantitative analysis of the benzanthrone aminoderivative binding to amyloid fibrils of lysozyme

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    The accumulation of amyloid fibrils in different tissues is associated with a number of neurodegenerative diseases. Despite a huge variety of amyloid-specific probes, all of them suffer from many drawbacks, highlighting the necessity of searching for more preferable dyes. In the present work, the potential of new fluorescent probe AM3 for selective detection of fibrillar protein aggregates, formed from lysozyme, has been evaluated. To quantify the affinity of this dye for amyloid fibrils, the isotherms of dye binding to the fibrillar lysozyme have been derived from fluorimetric titration. Parameters of the dye-protein complexation: association constant, molar fluorescence and binding stoichiometry, calculated from the Langmuir adsorption model, revealed that AM3 interacts strongly with protein insoluble aggregates. High values of the binding parameters make AM3 an alternative to a widely-used amyloid-specific probe Thioflavin T. We also investigated the effects of polarity and viscosity on AM3 fluorescence properties. The binding of AM3 to the protein hydrophobic cavities has been followed by red shift of the dye emission spectra, which can be explained by H-bonding between proton-donating groups of the protein and carbonyl moiety of the probe. Long-wavelength shift of emission maximum was observed also upon increasing the excitation wavelength. This finding suggests that reorientation time of solvent molecules is higher, than the dye fluorescence lifetime. Fluorescence anisotropy studies revealed slow rotation diffusion of the probe, bound to amyloid fibrils being indicative of high viscosity of AM3 microenvironment. The observed photophysical properties of the new aminobenzanthrone derivative make AM3 a perspective probe for basic research and medical diagnostics

    Assessment of fire safety of evacuation routes in industrial premises

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    The paper presents results of the development of new scientific and methodological principles for assessing the fire safety of industrial premises evacuation routes. The basis of these principles is the scientific methodology for managing industrial safety, developed at the department of life safety at the Perm National Research Polytechnic University. Following is discussed in the paper: 1) method of modelling scenarios for fire break-out and development based on Ishikawa diagram, 2) mathematical model describing the stepwise process of fire break-out and development in accordance with diagram topology, 3) indicator of fire safety of evacuation routes, 4) model for estimating the probability of evacuation of people along through the evacuation routes, 5) model for estimating the probability of evacuation from the premises. The developments mentioned above took into account problematic issues related to the behavior of people during a fire (operational actions to turn off equipment or stop the process, speed of human response to fire signals and decision time), movement of people during evacuation inside confined or limited spaces (mines, containers, wells, vessels etc.), remoteness of workplaces from evacuation routes (scaffolding, crane tracks, work at height etc.), reliability of evacuation warning and control systems, absence of a clear algorithm for constructing fire scenarios. The areas of scientific research application are identified. A method for assessing the safety of evacuation routes in relation to fire extinguishing substances of automatic fire extinguishing units that pose a danger to human health is considered. Examples of the application of scientific developments in the assessment of evacuation routes fire safety and modelling a fire scenario at a specific production facility are given
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