Journal of Civil Protection

Hydrometallurgical synthesis of copper composites in the presence of cerium and niobium oxides for protection of rescue equipment

Olga V. Reva — 2024-02-23

Purpose. To determine the optimal conditions for the hydrometallurgical synthesis of new nanostructured materials with improved functional properties for modifying parts of emergency rescue equipment.

Methods. The following research methods were used: gravimetry, voltammetry, radiography, X-ray spectral analysis, scanning electron microscopy, standard methods for testing the physical and mechanical properties of metal coatings.

Findings. It has been determined that coatings with a significantly distorted crystal lattice, without admixtures of amorphous phases are formed from a silicofluoride copper plating electrolyte, modified with an oxide phase. In the permissible range of current densities in silicofluoride electrolytes, side processes are minimized; in this case, cerium oxide exhibits electroactivity, but niobium oxide does not, creating diffusion difficulties and slowing down the rate of copper deposition. Inclusions of cerium and niobium compounds in the coatings were not detected, but the near-surface layers include copper and silicon oxides. The surface microstructure of Cu-CeO₂ and Cu-Nb₂O₅ coatings is dense and uniform. When CeO₂ is introduced into the electrolyte, the sizes of the grains composing the crystallites of the composites are noticeably smaller than in pure copper films synthesized under the same conditions; whereas the presence of niobium oxide in the electrolyte has virtually no effect on the microstructure of the films. It has been established that composites, synthesized in the presence of CeO₂, with the most uniform and fine-grained surface morphology, have increased corrosion resistance and 10–20 % higher microhardness compared to copper ones.

Application field of research. Corrosion protection and performance enhancement of fire rescue equipment parts, sealing of threaded joints of pipelines for various purposes.

Fire extinguishing and film-forming ability of fire extinguishing compositions based on fluorinated surfactants

Igor Yu. Ivanov — 2024-02-23

Purpose. To develop and test methods for determining the film-forming ability and fire extinguishing efficiency of compositions based on fluorinated and hydrocarbon surfactants when supplied in the form of water mist.

Methods. The general methodology of the work included the use of theoretical research methods (analysis, synthesis, comparison). The stability time of a vapor-proof aqueous film on the surface of a flammable liquid and the evaluation of the extinguishing efficiency of film-forming aqueous chemical fire extinguishing compounds were carried out experimentally. The obtained experimental data were processed using the estimation method and expression of measurement uncertainty.

Findings. A laboratory technique has been developed and tested for determining the stability time of a vapor-proof aqueous film from the solutions based on fluorinated and hydrocarbon surfactants on the surface of a flammable liquid. A laboratory method for determining the fire extinguishing effectiveness of finely dispersed water with surfactant additives when extinguishing a model class B fire has been developed and tested. The developed methods allow, at low cost, to conduct research on the development of new formulations of fire extinguishing agents used in the form of water mist. It has been experimentally established that a change in the concentration of hydrocarbon surfactants from 0 to 4 % leads to a decrease in interfacial tension from 5.86 to 1.26 mN·m^-1, an increase in the spreading coefficient of an aqueous solution over the surface of a flammable liquid from -1.06 up to 2.58 mN·m^-1 and increasing the fire extinguishing efficiency E_t by 25 times when extinguishing a model fire. An increase in the spreading coefficient of the water film leads to an increase in the fire extinguishing efficiency of fire extinguishing compositions based on fluorinated and hydrocarbon surfactants.

Application field of research. The results obtained can be used in developing the formulation of film-forming fire extinguishing compositions for extinguishing fires.

Approaches to the creation and use of computer-integrated complex for monitoring and forecasting of emergency risks at municipal and industrial wastewater disposal facilities

Vladimir N. Shtepa — 2024-02-23

Purpose. To analyze and justify the functional tasks of practical use of computer-integrated complex for monitoring and forecasting the emergency risks at municipal and industrial wastewater disposal facilities.

Methods. System analysis and functional modeling of information systems.

Findings. The relevance and prospects of the introducing information systems for assessing the state wastewater disposal with the task of predicting the emergency risks have been confirmed. The complete flow graph of computer-integrated complex was constructed, path matrices and an auxiliary matrix were analyzed, which made it possible to identify the subsystems of this complex. The functional tasks of the computer-integrated complex for monitoring and forecasting the emergency risks at municipal and industrial wastewater disposal facilities within the framework of the «Digital Water Utility» concept are substantiated. The approaches have been developed to include the complex in unified state system for monitoring water bodies with the prevention (avoidance) of negative consequences of emergency situations.

Application field of research. Digitalization of water supply and sewage facilities. Innovative solutions of counteraction to emerencies.

Research of accelerations arising under the action of inertial loads in the structures of fire truck tanks when moving to the place of emergency liquidation

Vadim A. Kovtun — 2024-02-23

Purpose. Experimental study of the influence of fire trucks driving modes on the level of acceleration values occurring in tank structures under the action of inertial loads. To achieve the goal, the work included the selection of the necessary measuring equipment, determination of sensor installation locations and experimental conditions, processing of the obtained experimental data.

Methods. During the research, modern measuring equipment was used, including the Larson-Davis 2900 noise and vibration analyzer, piezoelectric accelerometers of type 352C18. The obtained experimental measurement results were processed using mathematical analysis methods totake into consideration measurement errors.

Findings. The experimental studies results of the acceleration’s general level occurring on the walls and bottom of tank structures under various modes of movement of fire trucks are presented. As a result of data processing, the dependencies were obtained linking the parameters (speed, acceleration, braking, turning) and conditions (type of road surface) characterizing the features of the modes of movement of fire trucks on the chassis of MAZ-5337 and MAZ-6317 with the values of acceleration arising under the action of inertial loads in tank structures having a volume of 5, 8 and 10 m³. The obtained maximum acceleration values, which range from 7.4 to 25.2 m/s², indicate significant inertial loads occurring in tank structures and largely depend on the driving modes of fire trucks and the road surface. The data obtained confirm that fire tankers are operated in more severe conditions compared to other types of vehicles.

Application field of research. Firefighting rescue units, production and technical centers, industrial enterprises and higher educational institutions.

Chemical composition analysis of sediment on the casing of well-bore electric pump unit

Alla M. Braikova — 2024-02-23

Purpose. Determination of the chemical composition of a sediment sample on the casing and parts of a well-bore electric pump unit, which has been operated for several years under conditions of the Kursk-Belgorod anomaly; identifying the possible causes of unit failure and developing recommendations for equipment operation.

Methods. The program for studying a sediment sample has been developed, including determination of the mass fraction of organic substances (the organic component of the sediment) by the weight method, mass fraction of iron by the spectrophotocolorimetric method on an SF-2000 spectrophotometer, the mass fraction of manganese by the titrimetric method, content of zinc, cadmium, lead and copper by stripping voltammetry on the voltammetric analyzer AVA-3.

Findings. The content of organic substances in the sediment (50.1 %), mass fractions of iron (5.6 %), manganese (6.6 %), lead (3.4 %), zinc (0.017 %), copper (0.005 %) was established, no cadmium was detected. The probable reasons for the accumulation of sediment on the surface of a well-bore electric pump unit are formulated. Based on the results of the study, the recommendations were proposed for the operation of submersible electric pump units, including above all the need to take and analyze water samples from the well before installing the equipment.

Application field of research. Based on the results obtained from studying a sample of sediment from the body of a well-bore electric pump unit, the recommendations for the operation of the equipment were formulated.

Improving the safety of the EDK-2000 emergency recovery train railway crane by timely detecting defects in the pyramidal support stands

Alexander G. Otoka — 2024-02-23

Purpose. To analyze the possibility of using non-destructive testing methods to identify hidden surface defects in the pyramidal support stands of railway cranes EDK-2000 of emergency recovery trains.

Methods. Based on the physical properties of the material of the control object, eddy current and capillary flaw detection were used as methods for detecting defects.

Findings. In practice, capillary and eddy current control have shown excellent results in detecting operational defects that cannot be determined by visual inspection of pyramidal support stands of railway cranes of the EDK-2000 type. Depending on the condition of the surface of the support stands and technical features of the application of methods that affect their sensitivity, it is more expedient to carry out capillary control in combination with eddy current. The photographs with indicator drawings of defects detected by the capillary method in pyramidal stands are shown. The technology of eddy current control of the support is given, taking into account the sensitivity setting as SOP 2353.08 made of D16T alloy.

Application field of research. Railway transport.

Changes in operational indicator characteristics of the cardiovascular system of firefighter-rescuers defining the risk group

Ekaterina D. Tselykh — 2024-02-23

Purpose. Determination of operational indicator characteristics of the cardiovascular system of fire-rescuers after going on duty, the training process and liquidation of an emergency to identify a risk group.

Methods. The characteristics of the oxygen transport system were studied: heart rate; systolic and diastolic pressure (SBP and DBP); pulse pressure (PP); blood oxygen saturation (SpO₂), stress index (SI) of fire rescuers and fire truck drivers (comparison group) working in Khabarovsk. The functional characteristics of heart rate, SpO₂, SI were measured using the Angioscan-01P device; SBP, DBP by Korotkov method using a device for measuring blood pressure (BP) OmronM2 Eco. Anthropometric morphological indicators: height (H) and body mass (BM) were measured using a «Tvesm RP height meter» and a «VMEN-150-50/100-D2-A» floor scale. Calculated indicators are presented: PP and body mass index (BMI).

Findings. A tendency towards heigh H and BM indicators among drivers of fire trucks (group B) was determined. In all groups, BMI corresponds to the upper limit of the physiological norm and can be considered, taking into account the ±m range, as increased BM due to excess nutrition. Analysis of the indicator characteristics of the cardiovascular system (CVS) of fire-rescuers (group A) revealed that after going on duty (08.30) some indicators were above the standard limit, especially PP, which is consistent with the concept of functional-metabolic adaptation, which manifests itself before execution work for people associated with extreme loads. After training, most CVS indicators were practically restored to their original values. However, during training, PP increased, and after 60 min after trainig there was no PP recovery. A disadaptive change in PP after the elimination of an emergency is an indicator of a lag in the processes of restoring the balance of the autonomic nervous system (ANS) and can lead to headaches, disorientation, and temporary inability to make decisions. The most operational characteristic that determines the state of the fire fighters’ body when performing extreme loads is PP, which can be taken into account when admitting them to training and emergency response.

Application field of research. The results of the study can be put into practice in the form of proposals for carrying out preventive indication of PP and SI before going on shift to determine the risk group and ocorrective actions.

Peculiarities of lifting of non-Newtonian fluids in porous material

Dmitriy M. Nakhay — 2024-02-23

Purpose. To study the peculiarities of polymer solutions, rise of different concentrations in porous material.

Methods. Experimental method of research with the use of mathematical methods of processing of measurement results.

Findings. It was found that the intensity of saturation of porous material with polyacrylamide solutions significantly decreased after initial 30 s of the experiment. In addition, the rate of saturation of porous material decreased with increasing concentration of polyacrylamide in the solution. In contrast to distilled water, the polyacrylamide solutions continued to rise until the porous material was completely saturated, indicating the possibility of near-wall slip effect.

Application field of research. The obtained results are important for further investigation of the behavior of polymer solutions used at industrial facilities.

Improving the methodology of evaluating the effectiveness of the actions of officials of temporary control headquarters for emergency oil spill elimination in the Caspian water area

Adil A. Abdullaev — 2024-02-23

Purpose. Improving the methodology of assessing the effectiveness of the actions of officials of the temporary control headquarters for the elimination of emergency oil spill at sea.

Methods. General scientific research methods: analysis and synthesis, comparison and synthesis; critical path method.

Findings. Changes have been made in the methodology of assessing the effectiveness of the actions of officials of the temporary headquarters for managing the response to an emergency oil spill at sea, and the results of its testing during exercises are presented.

Application field of research. The results of the work can be used in practical activities in the management of emergency services of the Ministry of Emergency Situations of the Republic of Azerbaijan in wartime.