Experimental Evaluation of the Efficiency of Methods for Final Disinfective Treatment of Premises of the Large isolated Zones used for Work with Pathogenic Agents when Conducting Works with the Smallpox Virus

Objective. Determination of the effectiveness of final disinfection treatment of virological laboratory rooms (with the passageway room between two entries) in the isolated zone used for work with pathogenic agents, of the maximum containment laboratory by fumigation with formaldehyde vapors, including the assessment of the optimal amount of formalin. Experimental evaluation of the suitability of the aerosol generator “Ultrasprayer P-60” for the final disinfection of the premises of the “contagious” zone with the “dry steam” of hydrogen peroxide. Materials and methods. The effectiveness of the final disinfection of the surfaces in the premises of the “infectious” zone of the maximum containment laboratory was evaluated using cambric test objects contaminated by the spore-forming test-culture B. thuringiensis. Results and discussion. As a result of experimental studies, the required amount of formalin was determined that is sufficient to completely inactivate possible infectious contaminants that may be potentially located on the surfaces of equipment and rooms located in the “contagious” zone of the maximum containment laboratory, during fumigation with formaldehyde vapors. The amount of formalin specified experimentally turned out to be 1.4 times more than the recommended by regulatory documentation for unventilated rooms, but 2-2.5 times less than that used for final disinfection of maximum containment laboratory previously. Disinfection treatment of the premises and equipment located in the “contagious” zone of the laboratory with 6 % hydrogen peroxide “dry steam”, which is the active agent of Disargent drug, sprayed through the «Ultrasprayer р-60» aerosol generator, was more effective than spray irrigation with 6 % hydrogen peroxide aerosol generated using pneumatic aerosol nozzles. At the same time, it was possible to achieve sufficiently complete inactivation of the test microorganism located on test objects at a concentration of 1·106 cells/cm2, by increasing the concentration of hydrogen peroxide sprayed by the device up to 10 %. However, even in that case, viable test microorganisms remained in the hidden cavities of the equipment and office machinery, which makes further studies relevant to establish the optimal concentration of hydrogen peroxide during the final disinfection with an «Ultrasprayer р-60» aerosol generator or similar equipment from other manufacturers

Моделирование процессов температурной подготовки ракетного горючего в системе заправки стартового комплекса

It is necessary to carry out fuel temperature preparation for space launch vehicles using hydrocarbon propellant components. A required temperature is reached with cooling or heating hydrocarbon fuel in ground facilities fuel storages. Fuel temperature preparing processes are among the most energy-intensive and lengthy processes that require the optimal technologies and regimes of cooling (heating) fuel, which can be defined using the simulation of heat exchange processes for preparing the rocket fuel.The issues of research of different technologies and simulation of cooling processes of rocket fuel with liquid nitrogen are given in [1-10]. Diagrams of temperature preparation of hydrocarbon fuel, mathematical models and characteristics of cooling fuel with its direct contact with liquid nitrogen dispersed are considered, using the numerical solution of a system of heat transfer equations, in publications [3,9].Analytical models, allowing to determine the necessary flow rate and the mass of liquid nitrogen and the cooling (heating) time fuel in specific conditions and requirements, are preferred for determining design and operational characteristics of the hydrocarbon fuel cooling system.A mathematical model of the temperature preparation processes is developed. Considered characteristics of these processes are based on the analytical solutions of the equations of heat transfer and allow to define operating parameters of temperature preparation of hydrocarbon fuel in the design and operation of the filling system of launch vehicles.The paper considers a technological system to fill the launch vehicles providing the temperature preparation of hydrocarbon gases at the launch site. In this system cooling the fuel in the storage tank before filling the launch vehicle is provided by hydrocarbon fuel bubbling with liquid nitrogen. Hydrocarbon fuel is heated with a pumping station, which provides fuel circulation through the heat exchanger-heater, with hydrocarbon fuel returning to the storage tank.Mathematical models of cooling and heating processes are built on the assumption that the heat exchange process of storage and environment is quasistationary.The paper presents relationships for determining the relative masses of nitrogen and time to perform the operation of cooling fuel from the initial to the desired final temperature as well as relationships to define the time of heating operation for a given capacity of the heat exchanger-heater and the pump station fueling system.The results of calculations of the relative liquid nitrogen costs during cooling of hydrocarbon gases depending on the mass flow rate of nitrogen in the cooling fuel system are shown in comparison with experimental data and numerical calculations. The maximum error of analytical calculation results and experimental values of the relative cost of liquid nitrogen does not exceed 4.5% and the error in determining the time required for operations of temperature preparation does not exceed 5%.Analytical relationships and results of calculations obtained on their basis are adequate and in compliance with experimental results, in accuracy are on a par with results of numerical calculations and, as compared to numerical solution, greatly simplify a procedure of implemented design calculations of fuel temperature preparation processes. Using these relationships allows to analyze the effectiveness of the operations of heating and cooling hydrocarbon fuel depending on the design parameters of the storage capacity, its thermal insulation, mass of fuel, thermal power of the heating devices, flow of nitrogen, as well as to determine the required mass of liquid nitrogen and the operation parameters of cooling (heating) fuel for filling systems of launch complexes for different values of the environmental parameters, the initial and desired final temperaturesof the fuel.Разработаны математические модели и рассмотрены характеристики процессов температурной подготовки углеводородного горючего в системе заправки стартового комплекса, основанные на аналитических решениях уравнений теплообмена и позволяющие определять режимные параметры процессов охлаждения и нагрева топлива при проектировании и эксплуатации системы заправки. Приведены зависимости для определения относительной массы жидкого азота и времени охлаждения топлива, а также зависимости для нахождения времени нагрева топлива при заданных мощностях теплообменника-нагревателя и насосной станции заправочной системы. DOI: 10.7463/aersp.0615.082669

Tensor analyzing power Ayy in deuteron inclusive breakup at large Pt and spin structure of deuteron at short internucleonic distances

The Ayy data for deuteron inclusive breakup off hydrogen and carbon at a deuteron momentum of 9.0 GeV/c and large Pt of emitted protons are presented. The large values of Ayy independent of the target mass reflect the sensitivity of the data to the deuteron spin structure. The data obtained at fixed $x$ and plotted versus Pt clearly demonstrate the dependence of the deuteron spin structure at short internucleonic distances on two variables. The data are compared with the calculations using Paris, CD-Bonn and Karmanov's deuteron wave functions.Comment: 4 pages, 2 figures, talk given at the SPIN2004 Conf., 10-16 Oct. 2004, Triest, Ital

Measurement of the tensor Ayy and vector Ay analyzing powers of the deuteron inelastic scattering off berillium at 5.0 GeV/c and 178 mr

Tensor Ayy and vector Ay analyzing powers in the inelastic scattering of deuterons with the momentum of 5.0 GeV/c on beryllium at an angle of 178 mr in the vicinity of the excitation of baryonic resonances with masses up to 1.8 GeV/c^2 have been measured. The Ayy data are in a good agreement with the previous data obtained at 4.5 and 5.5 GeV/c. The results of the experiment are compared with the predictions of the plane wave impulse approximation and \omega-meson exchange models.Comment: 18 pages, 9 figure

Tensor Ayy and vector Ay analyzing powers in the H(d,d')X and ^{12}C(d,d')X reactons at initial deuteron momenta of 9 GeV/c in the region of baryonic resonances excitation

The angular dependence of the tensor Ayy and vector Ay analyzing powers in the inelastic scattering of deuterons with a momentum of 9.0 GeV/c on hydrogen and carbon have been measured. The range of measurements corresponds to the baryonic resonance excitation with masses 2.2--2.6 GeV/c^2. The Ayy data being in good agreement with the previous results demonstrate an approximate $t$ scaling up to -1.5 (GeV/c)^2. The large values of A_y show a significant role of the spin-dependent part of the elementary amplitude of the NN->NN* reaction. The results of the experiment are compared with model predictions of the plane-wave impulse approximation.Comment: 7 pages, 7 figures. submitted to Yad.Fi

Viability of sARs-CoV-2 Coronavirus strains on Different types of test surfaces, in Drinking Water and Their Resistance to Disinfectants

The purpose of the research was to study the dynamics of residual infectious activity of SARS-CoV-2 virus strains belonging to different genovariants, on different types of surfaces, in samples of drinking dechlorinated water at 24–28 °C, as well as their resistance to disinfectants.Materials and methods. The studies were carried out using SARS-CoV-2 coronavirus strains obtained from the State Collection of Causative Agents of Viral Infectious Diseases and Rickettsiosis, which operates at the premises of the SSC VB “Vector”. The evaluation of the residual infectivity of the SARS-CoV-2 coronavirus was carried out through titration of samples in cell culture.Results and discussion. The conducted studies have confirmed the ability of all investigated strains of the SARS-CoV-2 coronavirus to maintain their infectious activity at 24–28 °C on most of the examined types of test surfaces for at least 48 hours, while the virus is best preserved on stainless steel and plastic. All studied strains of the SARS-CoV-2 coronavirus are viable in drinking dechlorinated water for at least 48 hours. In addition, it has been found that all of them are sensitive to disinfectants of different groups, widely used for disinfection when working with pathogenic biological agents or for treating hands and surfaces contaminated with viruses. Chlorine-containing disinfectants are the most active. Skin antiseptics based on ethyl and isopropyl alcohols are suitable for disinfecting hands and objects contaminated with the SARS-CoV-2 virus