Pressure-induced amorphization, crystal-crystal transformations and the memory glass effect in interacting particles in two dimensions

We study a model of interacting particles in two dimensions to address the relation between crystal-crystal transformations and pressure-induced amorphization. On increasing pressure at very low temperature, our model undergoes a martensitic crystal-crystal transformation. The characteristics of the resulting polycrystalline structure depend on defect density, compression rate, and nucleation and growth barriers. We find two different limiting cases. In one of them the martensite crystals, once nucleated, grow easily perpendicularly to the invariant interface, and the final structure contains large crystals of the different martensite variants. Upon decompression almost every atom returns to its original position, and the original crystal is fully recovered. In the second limiting case, after nucleation the growth of martensite crystals is inhibited by energetic barriers. The final morphology in this case is that of a polycrystal with a very small crystal size. This may be taken to be amorphous if we have only access (as experimentally may be the case) to the angularly averaged structure factor. However, this `X-ray amorphous' material is anisotropic, and this shows up upon decompression, when it recovers the original crystalline structure with an orientation correlated with the one it had prior to compression. The memory effect of this X-ray amorphous material is a natural consequence of the memory effect associated to the underlying martensitic transformation. We suggest that this kind of mechanism is present in many of the experimental observations of the memory glass effect, in which a crystal with the original orientation is recovered from an apparently amorphous sample when pressure is released.Comment: 13 pages, 13 figures, to be published in Phys. Rev.

Algorithm of Emergency Elimination when Working inside Bio-Safety Cabinets with Pathogenic Biological Agents

Considered have been possible variants of emergencies, which may arise while working in BSC with pathogenic microorganisms. Put forward have been the algorithms for localization and control of the incident when working in BSC Safety Class II without spills; with spills within the working chamber; with spills and release of infectious material beyond the BSC working chamber; and incidents with compromised personal protection equipment

Two liquid states of matter: A new dynamic line on a phase diagram

It is generally agreed that the supercritical region of a liquid consists of one single state (supercritical fluid). On the other hand, we show here that liquids in this region exist in two qualitatively different states: "rigid" and "non-rigid" liquid. Rigid to non-rigid transition corresponds to the condition {\tau} ~ {\tau}0, where {\tau}is liquid relaxation time and {\tau}0 is the minimal period of transverse quasi-harmonic waves. This condition defines a new dynamic line on the phase diagram, and corresponds to the loss of shear stiffness of a liquid at all available frequencies, and consequently to the qualitative change of many important liquid properties. We analyze the dynamic line theoretically as well as in real and model liquids, and show that the transition corresponds to the disappearance of high-frequency sound, qualitative changes of diffusion and viscous flow, increase of particle thermal speed to half of the speed of sound and reduction of the constant volume specific heat to 2kB per particle. In contrast to the Widom line that exists near the critical point only, the new dynamic line is universal: it separates two liquid states at arbitrarily high pressure and temperature, and exists in systems where liquid - gas transition and the critical point are absent overall.Comment: 21 pages, 8 figure

Application of Risk Assessment Methodology for Substantiation of Measures Complex on Provision of Safe Functioning of Mobile Laboratories of Specialized Anti-Epidemic Teams

A set of risk assessment methods was used for substantiation of safe functioning of mobile laboratories (ML) of specialized anti-epidemic teams (SAET). The utilized methods were borrowed from diverse spheres of activity and recommended for evaluation of biological hazard and risk associated with work with pathogenic biological agents. The obtained data represent the basis for biorisk management in SAET` ML functioning

Development of Instruction and Methodical Data Basis of the Institution as an Element of Biosafety Provision as Regards Works with Pathogenic Biological Agents

A set of documents concerning biological safety at the institutional level is prepared and put in to practice. Three levels of specialists` admission for works with pathogenic biological agents of the I-IV groups have been developed, substantiated and introduced. Considered are the variants of execution of coupled (simultaneous) work with PBA of different groups. The statement on control of disinfectants received by the institution defines the order of control execution as regards newly received disinfectants and correspondence of disinfectants` working solutions in the laboratories to the requirements of sanitary regulations. Demonstrated is practicability of the assessment of protective efficacy of air-cleaning filters in the exhaust ventilation systems of “contaminated” area rooms in the laboratories carrying out the works with PBA using bacterial aerosol and physical method

Sanitary Protection of the Territories within the Frames of Sanitary-Epidemiological Welfare Provision

Demonstrated is the structural and functional interrelation between sanitary protection of the territories, epidemiological monitoring, and the state sanitary-epidemiological surveillance. Sanitary protection of the territories (SPT) of the Russian Federation is a separate focus area authorizing sanitary prophylactic (anti-epidemic) activities, with a self-sustained sub-goal. It combines individual roles appertained to epidemiological monitoring and to federal sanitary-epidemiological surveillance, only in reference to a particular item - emergency situation in the sphere of sanitary-epidemiological welfare of the population. Specificity of the SPT is a balance between functionality and capacity of the monitoring, surveillance and control. Legislative and regulatory legal acts, which concern sanitary protection of the territory, provide the means for defining its basic organizational principles: country-wide activities, self-sufficiency and self-support of the Rospotrebnadzor, three-level hierarchical system, and information exchange

Evaluation of the Effectiveness as to the Provision of Biological Safety of Works with Fixed Rabies Virus in the Process of Anti-Rabies Immunoglobulin Manufacturing

Analyzed is the performance of works with the strains of fixed rabies virus under the conditions of anti-rabies immunoglobulin manufacturing. Evaluated is the effectiveness of the established system for the provision of biological safety, which has allowed for safe manufacturing of anti-rabies immunoglobulin within the period of 12 years

Improvement of the Normative-Regulatory Framework Concerning Anti-Epidemic Procedures for Works with Infectious Disease Agents in Mobile Laboratories of Specialized Anti-Epidemic Teams (SAET)

Carried out is a range of investigations aimed at the improvement of the anti-epidemic procedures for works with infectious disease agents (herein biological safety provision) in mobile laboratories of specialized anti-epidemic teams (SAET). Evaluation of the operational experience of stationary and field laboratories, as well as comparative analysis of the national safety requirements for works with pathogenic biological agents and WHO international regulations in the sphere of biological safety provision in laboratories, has made it possible to outline common for all types of microbiological laboratories principles for biosafety provision. With due consideration of these principles formulated are the core requirements for the provision of biological safety of SAET activities. Based on the results of biorisk and biohazard assessment which have to do with innovative mobile laboratories, worked out is a system of anti-epidemic procedures aimed towards establishment of the conditions that offer as low as practically achievable level of risk for personnel of SAET mobile laboratories, for population and human environment too. These practices, designed for biological safety provision among the personnel of mobile laboratories (ML), have been played back in a number of standard operational procedures. With a view to establishing of the environment with acceptable level of biorisk for the personnel and population when ML are used for various purposes and in various contingencies (in full force, single unit or several modules), worked out are the algorithms of decision-making support as regards selection of modules and optional accessories. However, there is a need for emergency response plans and training programs for the personnel on the provision of biosafety in ML to ensure and maintain acceptable level of biorisk connected with ML functioning