bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of the probabilistic-temporal characteristics of wastewater of mechanical engineering enterprises
Authors: Alekseev V A , Usoltcev V P , Yuran S I
Published: November 2020

In the paper, the results of studies on simulating wastewater pollutant fluxes using averaged integral functional characteristics of the pollution occurrence time are given. The main elements of the effect of the probabilistic and temporal characteristics of the industrial wastewater pollutant fluxes on the average integral functional characteristics of the analytical wastewater control have been considered. The below parameters have been determined: mean no-pollution time, mean pollution occurrence time, the pollution inflow rate, and the average amount of pollution load over the monitoring period. The dynamics of detecting pollutants using express analysis of liquid fluxes when monitoring some specific wastewater pollutants in the enterprise water treatment systems have been analyzed. The technique for estimating the average wastewater pollution load proposed by the authors has been described, which is based on evaluating the average integral characteristics of various pollutant fluxes. The calculation equations are given to determine the average pollution load imposed by certain pollutants detected by the control system over the forecasted monitoring period. The calculation equations are given to estimate the mean total no-pollution time for certain pollutants over the monitoring period.
Numerical modeling of the spread of harmful substances from gas stations
Authors: Yaremenko S A , Bakaeva N A , Garmonov K V
Published: November 2020

The spread and influence of harmful substances from gas filling stations (gas stations) on nearby buildings, taking into account the aerodynamics of wind flows, is not well investigated. Studying process of the spread of harmful substances in natural conditions causes certain difficulties. Being based on the results of theoretical and experimental studies obtained earlier, the authors performed a numerical modeling of the spread of pollutants emitted from gas stations. As well the authors analyzed influence of these pollutants on nearby buildings taking into account the flowing air flows. The results obtained from numerical modeling make it possible to assess the state of the environment at any point and at any distance from the gas station and allows us to predict the degree of influence of atmospheric air pollution on the environmental safety of residential buildings during the construction of gas stations. Using numerical simulation, it also seems possible to assess the effectiveness of the implementation of planned measures to reduce the negative impact of harmful substances from gas stations.
The role of diatomite in the cultivation of legume grasses in modified black soil models
Authors: Oznobihina A O
Published: November 2020

In the Article, the data of vegetation model experiments conducted in field conditions are analyzed. As the baseline criterion of leached black soil contamination, the criterion of ecological and toxicological content of mobile forms of high-density metals in the soil corresponding to the bottom boundary of environmental disaster areas of soil contamination was used. The assessment of the effect of diatomite in contaminated agricultural soil in plantings of yellow sweet clover and purple medic test plants was conducted according to the quantity of metal accumulated by the crop. The use of diatomite in models of soils contaminated by high-density metals contributed to the decrease of accumulation in plants of sweet clover and medic of lead by 1.1-1.3 order of magnitude, of zinc 2.5-2.8 fold, and of cadmium 1.8-2.5 fold.
Surfactants for improving the safety of oil plant equipment operation
Authors: Tyusenkov A S , Latypov O R
Published: November 2020

The phenomenon of oil acidification is explained by the accumulation in its flow of electrostatic charges formed during pumping of water-oil emulsion through lined pipelines. Negative charges are accumulated by the water phase, and positive charges are concentrated in oil. These processes occur both in pipelines lined with polymeric materials and in steel pipelines that have only external insulation. The purpose of the studies was to determine the corrosion rate of the pipe steel in the stored charge sub-commercial water having different values of pH and redox potential, as well as to evaluate the possibility of using surfactants to reduce the redistribution of electrostatic charges.
Research of eyesight contrast sensitivity for the work with displays
Authors: Kudryashov A V , Kalinina A S , Tsurkan Y O
Published: November 2020

The article is devoted to determining the adaptation level of the visual system to illumination in condition of changing the surrounding field brightness arising from the dynamic control of artificial lighting in industrial premises, as well as when controlling the brightness of modern displays’ illumination. There is given a general idea of the visual system structure and retina properties and considered two consecutive mechanisms of adaptation to illumination. In the article an experimental calculation of determining the contrast threshold under conditions of complete adaptation is presented, the results of which allow us to conclude that there is no dependence of the color tone perception on brightness in a wide range of its measurements. The research materials can be used to create lighting control systems and select appropriate displays for operators of automated control systems in order to minimize the load on the organs of vision.
Reducing the natural risk of the people working in the open area by clothing based on textile operating systems
Authors: Rodicheva M V , Abramov A V , Gneusheva E M
Published: November 2020

The risk of a person’s hypothermia in the open area can be reduced by using heat-protective clothing based on textile operating systems. A method for studying unsteady heat and mass transfer in such clothes is proposed. Studies of heat and mass transfer processes in a package of traditional fabric materials and a textile operating system at an air temperature +5 °C were carried out. When doing light physical work, the efficiency of the packages is similar but the weight of the textile operating system is lower. When a human body is moistened by sweat, the textile operating system absorbs moisture better and removes it from the body, which improves the general condition of the person. With reduced physical activity the textile operating system restores the original heat-transfer properties quicker.
Use of oil sludge as a combustible additive for the production of bricks
Authors: Gorbaev A V , Gorlenko N V , Timofeeva S S
Published: November 2020

The impact of extractive industry facilities on the environment is manifested both at the construction stage and at the stage of their exploitation, and even after the exhaustion of natural resources. The relevance of this problem is becoming much higher for the oil and gas industry, where the processing and reclamation of drilling waste are of the highest importance. This makes it necessary to study possible ways of processing and obtaining useful components for the industry. We considered the most hazardous pollutant of almost all components of the natural environment of the oil and gas industry - oil sludge. We studied the possibility of its use as a secondary material resource, namely, as a combustible additive in the production of bricks to minimize anthropogenic environmental impact.
Conducting a comparative analysis of the system state options under various external influences
Authors: Romanovsky V L , Alekseeva E I , Gorina L N
Published: November 2020

One of the principles of increasing the sustainability of cities as a part of the campaign “My city is getting ready!” states: “Identification and study of risks, use of scenarios of existing and future risks”. The city is a complex system, “packed” with all kinds of dangers. Dangers affect all elements of this system and it is necessary to identify and monitor processes that contribute to the development of hazards into threats, i.e. conduct research, in this case, “urban risks” and learn to manage them. In our opinion, the “Tree structures” method of risk analysis may be suitable for the study of “urban risks” [14], which allows, in particular, to analyze various but interrelated situations and events in relation to the entire system within a single “tree”.
Organization of propaganda for the safe work production of a signaller and an automobile crane operator
Authors: Sevastyanov B V , Shadrin R O , Osmachko U A
Published: November 2020

Violations of the labor safety regulation and disregard of the rules concerning work performance are the main causes of industrial accidents. Labor safety propaganda should be organized at each enterprise. Propaganda teaches workers to have clearly perceived need to comply with the requirements for safe work performance, and is also an integral part of injury prevention. The paper presents the results of improving the safety of the work of the signaler and an automobile crane operator by means of promoting labor safety. The main traumatic factors for the above professions were identified. They are: the work of the machine operator, not performed at the signal of the signaler; work with a faulty safety lock, as well as work with faulty safety devices and faulty equipment; unloaded cargo at the end of work and during work breaks, excess load capacity; performance of works when there are people in the danger zone (unfenced territory), and as a result, presence of the injured person in the danger zone of the crane work; contact with electric current, in the absence of grounding of the crane. For each identified factor, a poster was developed reminding of the need to comply with labor safety rules. The developed posters were introduced into production during the operation of automobile cranes in the Izhevsk branch of Federal State Unitary Enterprise “Main Military Construction Directorate No. 7” (FGUP “GVSU No. 7”).
On the application of methods of correlation-regression analysis and fuzzy logic in the analysis of industrial injury rates
Authors: Sevastyanov B V , Shadrin R O , Lisin V A
Published: November 2020

The paper discusses the results of applying the methods of correlation-regression analysis and fuzzy logic for analyzing the statistical information of industrial injury rates in the Udmurt Republic, and shows the stages of modeling. Correlation-regression analysis was carried out using the MS Office Excel “Data Analysis” package; processing by the Mamdani algorithm (fuzzy logic) was carried out in the Mathlab environment. For the number of workers injured with further disability per 1 working day or more and fatal outcome in the Udmurt Republic, the results of using both methods are shown. Recommendations are given on the application of a particular method in the practical activities of managing the labor protection of organizations as a whole, by type of economic activity or constituent entity of the federation. Recommendations are provided, the implementation of which will improve the accuracy and efficiency of the analysis of industrial injuries by the considered methods.
Accumulation of natural radionuclides by soil and vegetation in the South of the Tyumen region
Authors: Burlaenko V
Published: November 2020

The article is focused on the results of studying the radiation condition of the soil and grassy vegetation represented by perennial grasses (meadow bluegrass, reed warbler, stonecrop, clover, sedge, timothy) in the South of the Tyumen region. The specific activity of natural radionuclides (K-40, Th-232 and Ra-226) in the profile of gray forest soil of the Nizhnetavdinsky district was established, the specific effective activity of radionuclides in the soil was calculated. Comparative analysis of the obtained results together with the data on administrative districts of the South of the Tyumen region showed that in the soil of the Nizhnetavdinsky district, specific activity of natural radionuclides exceeds the similar indicator typical for the South of the region.
Technological process of rescue operations in conditions of mass destruction. System-integrative aspect and principles of organization
Authors: Chumak S P
Published: November 2020

In the presented article, the author substantiates the feasibility of using the “process approach” in organizing emergency rescue operations in the conditions of destroyed buildings and structures. It is noted that the advantage of the process approach is that it can be used when considering various solutions to typical organizational and technological problems and predicting the processes of emergency rescue operations ERO. The author emphasizes that the process of conducting the ERO should be considered as a complex hierarchical multicomponent dynamic system, the levels of which are characterized by diverse coordinating relationships and a certain subordination. Taking into account this circumstance, new principles of organizing the production process of ERO in the conditions of mass destruction are justified. Of practical importance is the possibility of applying these principles in the development of methodological approaches to optimizing emergency rescue operations ERO processes, substantiating rational technologies for their implementation. In General, the article presents a new, original approach to the organization and conduct of rescue operations, based on the account of organizational and technological features of large-scale emergencies and the results of the study of the system-integrative aspect.
Supraresilience of bio-socio-technical infrastructures
Authors: Timashev S A
Published: November 2020

The paper is one of the first attempts dealing with the problem of creating, providing and maintaining antifragility of systems of critical infrastructures in the wake of black-swan type biological, technological, ecological, economic or social catastrophes occurring in a municipality or territory. A synonym is offered to describe antifragility (as defined by N.N. Taleb) from a positive psychology perspective, formulating the problem as the supraresilience problem. Initial data, problems to be solved, resilience metrics, methods and tools needed for providing practical urban/regional resilience and risk management are discussed and formulated. A verbal and formal definitions of the supraresilience of bio-socio-technical infrastructures are proposed.
Identification of formation factors for ecological state of soils, and impact of overburden
Authors: Pochechun V A , Semyachkov A I , Kuchin V V
Published: November 2020

In this paper formation factors for ecological state of soils in the location area of rock overburden dumps formed as a result of the development of Gusevogorsky deposit are studied. Gusevogorsky deposit is located in the Kachkanar district of the Middle Urals. This deposit contains vanadium-containing titanomagnetite ores, and therefore the rocks and ores of this territory contain the following association of chemical elements: vanadium, cadmium, silicon, arsenic, nickel, chromium, and zinc. A rock overburden dump is a potential source of anthropogenic impact on environmental components, including soils through fugitive dust emissions. Thus, in our work two formation factors for ecological state of soils in the given territory are considered: 1) overburden rock geochemical composition; 2) pollutant dispersion air streams from the dump.
Increasing efficiency of use of dryers at the gas-processing enterprises
Authors: Abdulkerimov R F , Chekushina T V , Vorobyev K A
Published: November 2020

Gas is the most environmentally friendly type of fuel and its role only increases over time. According to experts ’ forecasts by 2050 its role in the world’s energy balance will be 28-30 %. The main technological process used in gas production and transportation is the drying process. Annually, about 20-25 billion cubic meters of associated petroleum gases are processed at gas processing plants. In Russia, the production of liquefied natural gas is becoming more popular. The quality of associated petroleum gas intended for processing is subject to high demands, such as purification of methanol, mercury and gas dehydration. Mostly dehydration is carried out using zeolites. The paper presents the result. On the territory of Russia, a significant proportion of gas fields contain hydrogen sulfide and organosulfuric compounds, without purification from which gas can not be sold to the main gas pipeline system and consumers. The organization of gas production at the Orenburg and then Astrakhan fields required the use of technologies for gas purification from hydrogen sulfide, production of gas sulfur and post-treatment of tail gases of sulfur production, as well as gas purification from organosulfur compounds.
Determining the composition of therapeutic mud and sewage sludge of mud baths for their subsequent disposal
Authors: Arkanova I A , Markov P A
Published: November 2020

The composition and characteristics of therapeutic mud and sewage sludge of mud baths are studied in the article. The use of the X-ray fluorescence method makes it possible to determine the composition and percentage of elements in the resulting waste of mud baths. The studies are carried out using a sample of natural therapeutic mud from the Sulfatnoe Lake of the Kurgan Region and natural sewage sludge generated after treatment. The study of the elemental composition of natural mud and sludge have shown a high content of silicon dioxide, aluminium oxides, as well as compounds of calcium, magnesium and other elements. Possible options for the disposal of waste mud and sludge by using them in various industries, such as road construction, agriculture, production of structural materials, are proposed. Based on the results of the study, the article also concludes that it is possible to use the sludge in the construction industry.
Features of ventilation at the enterprises of metallurgy and mechanical engineering
Authors: Skorik T , Galkina N , Glazunova E
Published: November 2020

The processes of foundry of machine-building enterprises are accompanied by the release of excess heat and a large number of hazards. Reducing the harmful impact of enterprises on the environment should be ensured by a complex of technological and construction measures, as well as the effective operation of ventilation systems. When designing ventilation systems, it is necessary to solve an optimization problem that takes into account their energy and environmental reliability, and economic efficiency. As a result of the analysis of the reliability of ventilation systems, their energy efficiency, heat consumption for the needs of heating and ventilation of a number of metallurgical industries, in order to reduce operational energy costs, it is recommended to solve a set of problems that include increasing the level of use of secondary energy resources. The authors propose a cyclone-heat exchanger, where cleaning of dust and gas flow and its heat recovery are combined in one apparatus. Design and construction of energy-efficient ventilation systems with high technological reliability will reduce operating power consumption from 30 to 75%.
Use of vegetable oil refining waste to remove oil products from sewage
Authors: Porozhnyuk L A , Lupandina N S , Porozhnyuk E V
Published: November 2020

The relevance of the research is due to both problems arising from the pollution of surface water with oil products, and the possibility of expanding the range of effective sorbents through the use of industrial waste. The article presents the results on the selection of purification parameters for model effluents containing industrial oils as a type of oil product. Purification was carried out by a sorbent made on the basis of the waste formed during the purification of vegetable oils from waxy impurities. The sorbent was obtained as a result of roasting secondary silica-containing raw materials of oil extraction production in a certain temperature range. It was revealed that the heat treatment of the waste leads to a partial burnout of the organics and the preservation of the paraffin fractions that make up the waxy impurities. Due to this, thermally modified waste becomes hydrophobic and oleophilic; contributes to an increase in oil absorption. In the course of the study, the influence of a number of factors was established, such as the temperature of waste roasting, the duration of contact of the sorbent and the purified medium, the mass of the sorbent, on the efficiency of the process of purifying model solutions from oil products.
Development of engineering and technical environmental measures for technogenic atmospheric pollution by thermal power facilities
Authors: Zvyagintseva A V , Sazonova S A , Kulneva V V
Published: November 2020

Technological processes are considered at the objects of heat power engineering - combined heat and power plants. The principle of operation of heat power facilities is considered on the example of the Voronezh TPP-1. The equipment is considered, with the help of the rational use of which the required level of ecological safety of the technogenic object can be achieved. Taking into account the peculiarities of the processes carried out at Voronezh TPP-1, the most effective set of engineering, technical and environmental measures aimed at reducing the technogenic impact of the TPP on the city’s atmosphere is proposed. In developing recommendations on the use of effective environmental measures at the CGP, the works were considered.
Fe-Cu aluminosilicate catalytic materials for oxidation of azo dyes
Authors: Khankhasaeva S Ts
Published: November 2020

Fe-Cu aluminosilicate materials were obtained by replacing exchangeable cations of bentonite clay with polymer hydroxocations of iron and copper. The specific surface and porosity characteristics of the synthesized materials were determined using low-temperature nitrogen adsorption. It was established that modifying clay with iron and copper complex compounds and heating at 400 °C and 500 °C led to the formation of microporous materials with a specific surface area of 140-152 m2.g-1. The catalytic properties of Fe-Cu aluminosilicate materials were studied in the oxidative degradation reaction of a diazo dye “direct pure blue” in aqueous solutions using hydrogen peroxide as oxidizing agent. It was shown that the materials were active catalysts for the dye oxidation and increased oxidation efficiency to 78-96% for 360 min at 40 °C. The results of the research allow to conclude that obtained Fe-Cu-aluminosilicate materials can be successfully used in the catalytic treatment of wastewater from organic dyes.
Sonophotocatalytic (1.7 MHz, 254 nm) destruction of Bisphenol-A in aqueous solutions
Authors: Aseev D G
Published: November 2020

Bisphenol A (BPA) an organic compound largely used in the plastic industry as a monomer. The micropollutant BPA (43.8 μM) was employed under conditions of high-frequency ultrasound (1.7 MHz, 25 W) and ultraviolet radiation (254 nm). To enhance degradation a Fenton-like oxidation system was used, including persulfate as an oxidizing agent and ferrous iron (Fe (II))) as a catalyst. Experiments were carried out in a flow sonophotoreactor, flow rate 0.5 l/min. The progress of the treatment of Bisphenol-A solution has been monitored in terms of reduction in the concentration (HPLC) and dissolved organic carbon (DOC). A large synergistic effect (2.4) was shown in the oxidation of Bisphenol-A from the combined effect of two directed at each other sources of ultrasound. The efficacy of combined approaches was generally higher than individual treatment methods of sonolysis (87%) and photolysis (15%) in 240 min of treatment. Complete oxidation of BPA is achieved in the {UV/US/Fe2+/S2O8
2-} system in 120 minutes, however, mineralization reaches (50%), possibly due to the lack of an oxidizing agent. The reaction rates of Bisphenol A degradation and mineralization increase in the order: {UV} <{US} <{Fe2+/S2O8
2-} <{US/Fe2+/S2O8
2-} <{UV/US/Fe2+/S2O82-}.
Adsorption properties of nanostructured form of aluminium hydroxide γ-modification
Authors: Filatova E G , Dudarev V I , Begunova L A
Published: November 2020

Adsorption properties of aluminium hydroxide γ-modification towards toxic copper(II) and zinc(II) ions were studied. In a neutral medium at pH=7.6, the ion adsorption capacity was 264 mg/g for copper(II) and 338 mg/g for zinc(II). The study of the temperature effect on the absorbability of toxic ions established that the adsorption capacity is characterized by an increase followed by a decrease as the equilibrium value is reached. The absorbability increase in the initial moment is caused by an increase in the formation rate of hydroxo aqua complexes of copper(II) and zinc(II) ions. The differential heat of adsorption was determined. It demonstrated a decrease from 27 to 20 kJ/mol during the process, which is caused by the fact that, as the most active centres of nanostructured form of aluminium hydroxide γ-modification are saturated, heavy metal ions are adsorbed by decreasingly active regions of its surface.
Sorption post-treatment of accumulator waste
Authors: Kachalova G S , Chuklin K A
Published: November 2020

Annotation. The main goal when creating typical waste water of JSC “Tyumen Battery Plant” is to bring the composition as close as possible to real waste water. The aim of the work is to study the process of sorption post-treatment when working with different types and concentrations of coagulants and flocculants, to select the most effective coagulants and flocculants and their doses, which give maximum effect of sorption post-treatment from colloidal-dispersed impurities and lead ions. For work the following coagulants were selected: FeSO4·7H2O; FeCl3 and Al2(SO4)3 in various relations (1:1), (2:1), (1:2); Flocculants: Flopam FO 4125 SH, Flopam FO 4440 SH, Flopam FO 4115 SSH; Praestol 2531 TR, Praestol 650 TR, Na2O · mSiO2 · nH2O sodium metasilicate (Liquid glass). In process of operation method of dynamic sorption on sorbent of KΦГM-7 is used for additional purification of waste water from lead ions. Based on the data obtained, recommendations can be made to intensify the subsequent treatment of waste water from battery production using the following reagents: FeCl3 (83mg/l) + Al2 (SO4)3 (42mg/l) and Liquid glass (1mg/l); FeSO4 7H2O (150g/L) и Flopam FO 4115 SSH (1mg/L); FeSO4 · 7H2O (150 mg/L) and liquid glass (1 ml).
Effectiveness of sonophotolysis for eliminating bisphenol A and bacteria from aqueous solution
Authors: Tsenter I M , Popova S A , Garkusheva N M
Published: November 2020

This study focuses on the improvement of the effectiveness inactivation of microorganisms and degradation of micropollutants using of AOPs (advanced oxidation processes) methods in deionized water. The effectiveness of sonophotolysis for degrading bisphenol A (BPA) and inactivating bacteria Escherichia coli and Enterococcus faecalisin aqueous solution was investigated using ultraviolet light-emitting diodes (UV LEDs, 365 nm) and high-frequency (1.7 MHz) ultrasound (US). The sonophotolytic system UV/US was highly efficient for inactivating E. faecalis, whereas no US contribution was observed for E. coli.A synergistic effect for sonophotolysis of BPA was found. We suggest that the obtained results are promising for developing modern sonophotochemical methods for water treatment and disinfection.
Options for evaluating the project efficiency: technospheric security factor
Authors: Skvortsova N , Matys E , Uze E
Published: November 2020

In the context of a fall in consumer demand due to a decrease in cash incomes of the population, starting in 2013, a decline in business activity in the investment and construction market of Russia has been observed. The recession was noted even in regions that were previously the locomotives of the construction boom. In accordance with this, against the background of general stagnation of the economy, the only way out in this situation should be recognized as a way to improve the quality of products to maintain market share. According to experts, over the past ten years, the quality of traditional construction products manufactured by domestic manufacturers has significantly increased, but there remain problems of aging production technologies, the quality of raw materials, the low level of qualifications of specialists in the construction industry, etc. A varied approach to the choice of production technology for building products and building technology makes it possible to react flexibly to emerging environmental challenges and the deterioration of key indicators of business activity in the construction business in modern conditions of risk and uncertainty at macro and micro levels.
The use of vegetable oil waste for the sewage purification from dyes
Authors: Lypandina N S , Porozhnyuk L A , Gavrish V M
Published: November 2020

Currently, the search for new methods of wastewater treatment is an urgent task. In this work, investigation was carried out on the treatment of sewage containing dyes using modified waste generated during the refining of oils. During the research, the influence of various physical and chemical factors on the efficiency of sewage containing dyes was investigated. As a result of investigation on model sewage, it was found that when using modified waste, the maximum cleaning efficiency reaches 98%. At the same time, the following environmental problems are being solved simultaneously: reducing the amount of man-made waste and, as a result, reducing the area for its storage and treatment of waste water containing dyes.
Experimental investigation of star grains in dual thrust solid propellant motors
Authors: El-Naggar M , Belal H , Abdalla H M
Published: November 2020

One of the great challenges in designing tactical solid missiles is to achieve high acceleration in the boost phase then maintaining constant speed during the sustain phase. This could be achieved by using a dual thrust solid-propellant rocket motor. Many of these tactical motors use a combination of star, tubular or finocyl grains to achieve this profile. The present study uses two tandem star grains with different design parameters and different transition geometry. Previous researches had consistently shown that the main advantage of star grain is the potential higher volumetric loading in addition to high tailorability. The pressure-time curve for the designed grains is calculated using a zero-dimensional internal ballistic module and a small-scale test motor is used to verify the calculated pressure-time curve. Different transition geometries are compared. Tapered transition is shown to give a comparable performance with the sharp transition with the advantage of higher volumetric loading.
Mitigation of irregular burning in a small solid propellant rocket motor
Authors: Elkshen M , Belal H , Al-Sanabawy M A
Published: November 2020

An irregular burning phenomenon arises in some solid propellant motors(SRM), where the time-averaged pressure differs largely from that dedicated by instantaneous area burning. This phenomenon is generally considered the result of the interaction of pressure disturbances within the motor cavity with solid propellant deflagration. Hence, it is a combustion-dependent acoustic phenomenon. Historically, different suppression devices included the classical resonance rods and paddles, and arrays of acoustic resonators and various baffle arrangements were applied. In this paper, irregular burning which arises in a modification of a shoulder-launched rocket is investigated. Several techniques dealing with the irregular burning problem were attempted. In each case, the signal of pressure was analysed in the time domain through time average and AC pressure signal, and in the frequency domain through Fourier transform and power spectral density. The most successful technique was the drilling of holes through the grain, connecting the perforation to the external burning region of the cylinder. Next was the increasing of blocking factor, both methods lead to stabilizing the modified motor.
Validation of relations for the determination of pyrotechnic igniter mass
Authors: Salama A , Belal H , Abdalla H M
Published: November 2020

Propellant ignition is an essential process in solid rocket motor operation as it is responsible of starting the combustion and to reliably self-sustain burning of the solid propellant. Despite the importance of igniter design and ignition process, the relations dealing with igniter mass determination are not well studied and not validated against actual motors with a systematic variation of parameters. The main objective of the current research is to validate the available equations in open literature for determination of the mass of igniter pyrotechnic charge. Data from seven real solid propellant rocket motors were used to validate the relations. These motors have different sizes, grain geometries and pyrotechnic compositions. The results show that the equation of Brayan–Lawerene has the smallest root mean square error (RMSE), and so, it is considered more convenient.
Optimization of friction stir welding parameters using response surface methodology
Authors: Sabry I , Gadallah N , Abu-Okail M
Published: November 2020

The aim of this article is to create a new technique for predicting discontinuity formation, its place and magnitude during aluminium alloy (AA6061) friction stir welding (FSW). The effectiveness of the technique was demonstrated using visual inspection, hardness and tensile test of the friction stir welded joints. The measured current was analysed through power calculations. In each of the FSW stages, the energy consumption is significantly varied, clearly distinguishing the penetration of the tool, its revolution, its traverse movement and its metal removal rate. The findings of tracking the energy consumption indicate that using power consumption means the significance of weld quality. FSW has been carried out based on two factors - two levels. Response surface methodology (RSM) is employed to develop a mathematical model. Analysis of variance (ANOVA) technique checks the adequacy of the developed mathematical model, which is used effectively at 95% confidence level. In contrast, tensile and hardness tests also showed that welds at high power usage failed continuously within the welding area, due to reduced welding temperature and absence of penetration in the welding zone.
The effect of tire rubber particles on the mechanical and physical properties of polyester
Authors: Abo Elenien K F , Azab N A , Bassioni G , Abdellatif M H
Published: November 2020

In this work, a novel composite of polyester with rubber particles-obtained from recycled wasted car tires - was developed. Worn tires generate a large amount of wastes that do not derogate resulting in environmental problems. This has the advantage of producing useful product that is economical and eco-friendly. The effect of the volume fraction of the rubber particles in the composites on the physical and mechanical properties of the composites was studied. Varying the volume fraction from 0-60% resulted in an increase in the impact properties. The addition of rubber particles had also the effect of reducing the density of the composites which is a desirable property.
Experimental and computational dynamic structural analysis of free-flight rockets
Authors: Habaka M A , Farag SS , Khalil M , Ahmed M Y
Published: November 2020

Aerospace vehicles’ designers often strive to approach the lightweight structures in order to improve flight performance without compromising vehicles durability. However, this goal may be achieved on the expense of structural rigidity of the vehicle. A missile with high slenderness ratio is a typical vehicle that should be considered as flexible body if precise dynamic behaviour analysis is sought. This analysis is crucial to identify the flight performance of such missile with high accuracy. The present paper discusses the results of a side-by-side experimental and numerical analysis of the vibration characteristics of a full-scale free-flight missile having 70mm caliber. The experimental modal analysis is conducted on the missile with empty motor to represent its unpowered flight regime. Experimental modal analysis setup involved accelerometer sensors while vibration excitation is achieved using an impact hammer. Modal analysis is also conducted numerically using a well-used high-fidelity commercial tool. Results of experimental modal analysis have shown that the first four modes as bending modes with frequencies of 134.4, 400.6, 819.4 and 1173.6 Hz, respectively. The results also demonstrate the close agreement between numerical and experimental approaches.
Assessment of St. St. 316L joints welded by laser beam and metal active gas MAG processes
Authors: Magdy A M , El-Shabasy A B , Hassan H A
Published: November 2020

Study the welding of Stainless steel 316L sheet was carried out using two welding techniques, Laser beam and Metal Active Gas MIG. Strips of 1.5 mm thick were cut from the Stainless-steel sheet and then welded using nitrogen gas for shielding. Metallographic examination using optical microscopy and SEM was conducted to study the microstructure of the welded joints. The tensile stress for joints welded by Laser beam and MAG were ranged from 386 to 632 MPa and from 126.5 to 599 MPa respectively according to the parameters of each welding techniques. The average of microhardness values measured at successive distances for joints welded by Laser beam and MAG were 265 HV and 261 HV, respectively. The obtained results were analysed and discussed based on the recent research.
Experimental investigation and numerical simulation of the thermosyphon heat pipe charged with R134a
Authors: Zakaria S Y , Ibrahim A G , Rashad A M , El-shamarka S E
Published: November 2020

This work presents an experimental and numerical study of Two-Phase Closed Thermosyphon (TPCT) heat pipe filled with R134a as a base fluid. For this purpose, a test rig was designed and developed toper form a series of tests on the TPCT heat pipe by applying different heat inputs at the evaporator section. The surface temperature along the TCPT heat pipe and temperature changes of the cooling water across the condenser section were measured. The influence of the TCPT heat pipe operating conditions on its thermal performance was reviewed. The considered parameters were; heat pipe transport capacity, conductance, both heat transfer coefficients of the evaporator and condenser sections and the thermal efficiency. Then, a CFD model was developed to investigate the two-phase flow and heat transfer mechanism during the transient and steady-state operation of the TPCT heat pipe. The results of the experimental work were used to validate the CFD model and acceptable agreements were noticed. The validated CFD model is utilized to predict features of the mass and heat transfer processes, as well as the nucleate pool boiling and the liquid film condensation phenomena during TPCT heat pipe operation.
Design of gain scheduled fuzzy PID controller for multi-link robot manipulators
Authors: Emarah Maya
Published: November 2020

Gain Scheduling (GS) controller is one of the most popular approaches to nonlinear control design. Commonly, Gain Scheduling (GS) controllers have better performance than robust ones. In this paper, the structure of a proposed gain scheduled PID fuzzy controller (GS-PIDF) designed and analyzed. The Fuzzy PID controller gains weighted through gain scheduling designed system to grantee both the stability and the best performance of a multi links robot manipulator system. The overall designed controller system is applied to two links robot manipulator system, which is subject to modelling using Lagrangian dynamics method and simulation vie MatLab and Simulink package to minimize the vibration and acquire best performance.
Design of bio-inspired muscle sarcomere structure using a hybrid hydrogel-IPMC actuator
Authors: Hamdi H M , Abdelwahhab SA , Awad MI , Tolbah FA
Published: November 2020

Biological muscle is considered a powerful actuator due to its flexibility, lightweight, and efficiency. The building unit of a muscle, sarcomere, and the study of its energy balance cycle is considered in researches due to its importance to mimic the micro-level muscle structure to improve the artificial muscle performance. In this work, a new design of a linear actuator based on the sarcomere behavior is developed. The design is inspired by studying the four steps adenosine triphosphate (ATP) hydrolysis cycle, which is the main source of the required energy for sarcomere contraction. A new developed hybrid hydrogel-polymeric material actuator is designed in this paper using a combination between Ionic Polymeric Metallic Composites (IPMC) and hydrogel to behave like the sarcomere. This new actuator proposes an autonomous cycle using the effect oscillatory Belousov–Zhabotinsky (BZ) reaction. The physical model is proposed, and the mathematical model of the actuator is derived and formulated and identified using MATLAB/Simulink.
Computational fluid dynamic model for machining using minimum quantity coolant
Authors: Abdelfattah W , Hegab H , Mohany A , Kishawy H A
Published: November 2020

The cooling applications during machining has significant effects on the production costs, surface quality, and the mechanical properties of the final product. In conventional flood cooling, a large amount of continuous cooling fluid is usually used, and that increases the cost of the product as well as the harmful effects on the environment and the machining operator. This study focuses on simulating alternative cooling system, called minimum quantity coolant (MQC), which used an optimal flow rate compared to classical flood cooling. The cooling fluid is directly provided to the cutting edge through the insert holder. In the current work, a computational fluid dynamic (CFD) model has been developed to study the effects of the cooling fluid velocity on the accessibility of coolant to the chip-tool interface area under using various types of cooling fluids. Three types of coolant are used (i.e. water, mineral oil, and nano-fluid). The results of the proposed CFD model have been classified into two phases. The first phase obtains the coolant accessibility percentage into the chip-tool interface (MA%) with different coolant velocities (i.e., 0.5, 1, 1.5, and 2 m/s) for the three studied coolants. The second phase discusses the heat transfer effectiveness for the employed coolants with different inlet velocities since it is an important aspect, especially when machining hard-to-cut materials. It was found that increasing the coolant velocity would increase the coolant accessibility percentage into the chip-tool interface area. However, no significant effect has been found after 1.5 m/s for all employed coolants.
Optimizing ladle-refining performance during treating special steel melts for aviation technology
Authors: Elghazaly S A , Gyula K K , Elghazaly W S
Published: November 2020

The ever increasing demands of consumers towards superior quality steel products urged steelmakers to consider the implementation of various relatively new metallurgical technologies into the classical operations. The necessity to produce high quality steels led to the use of two stage steel production processes, one is the primary steelmaking and the other stage is the outside furnace treatment through which many metallurgical functions can be achieved like degassing, stirring and inclusion removal, Inclusion modification, desulphurization, deoxidation, decarburization, heating and alloying. In this research a trial was done to optimize the performance and usage of 30tons-ladle refining system during production of X65-pipeline steel as final product-Aluminium killed steel melts through controlling the mass flow contour using optimized modelling, optimum usage of Al2O3 and Sulphide modifiers and enhancing removal of non-metallic inclusions by altering their morphologies and hence floatation speed. Assessment of fine clusters of inclusions in the final steel product has been industrially correlated to the cleanness of melt before refining, to the slag composition and to the parameters of materials flow rates as well as their effects on the mechanical properties of final X65-steel product. Scanning-EM+DX analyzing unit and metallurgical microscopes were used to emphasis qualitatively and quantitatively the characters of non-metallic inclusions.
A novel modified cellulose nanomaterials (CNMs) for remediation of chromium (VI) ions from wastewater
Authors: Kara Hizkeal Tsade , Anshebo Sisay Tadesse , Sabir Fedlu Kedir
Published: November 2020

Wastewater (WW) remediation technologies were the most crucial issues all over the world at present time. Thus, the remediation of Cr (VI) ions from real WW was conducted using green biocompatible and biodegradable pristine (CNM) and succinic anhydride functionalized cellulose nanomaterial (S-CNM) adsorbents. Both CNM and S-CNM adsorbents were prepared by using sulfuric acid hydrolysis method and characterized for particle sizes, functional groups, and surface morphologies by using XRD, FT-IR, and SEM instruments, respectively. The physicochemical properties of the collected WW were investigated. Next, both the prepared adsorbents were applied for the remediation of Cr (VI) ions from WW. The remediation processes is spontaneous and have higher remediation efficiencies of Cr (VI) ions from WW. The Cr (VI) ions remediation mechanism was evaluated from both the Cr (VI) ions adsorption isotherms and kinetic concepts. Both Langmuir and Freundlich Cr (VI) ions adsorption isotherm models were certainly fixed to a maximum Cr (VI) ions uptake capability (qmax) of 60.24 and 156.25 mg g−1 by CNM and S-CNM sorbents, respectively, and it follows pseudo-second-order (PSO) kinetics model through chemisorption processes. The Cr (VI) ions uptake capabilities were hindered by the presence of organic matter and any other competing pollutants in the WW. The S-CNM sorbent was selected for the regeneration study due to its higher efficiencies of remediation relative to CNM sorbent and the study was conducted through desorption of Cr (VI) ions by using HCl. Findings have shown that the sorbent was easily recyclable and applicable for the remediation of pollutants from real WW after consecutive 13th cycles.
Research on microstructure and properties of Ti-15Mo-3Al alloy with high oxygen content
Authors: Xu Zaidong , Wang Yanjing , Xu Rongzheng , Hu Qiuye , Shi Dongyu , Lu Xin
Published: November 2020

In this paper, the near-equilibrium microstructure and properties of Ti-15Mo-3Al-1O alloy treated by solid solution at different temperatures were systematically studied. The microstructure of the alloy was observed and analyzed by optical microscope (OM), scanning electron microscope (SEM) and x-ray diffraction (XRD). The results indicated that the microstructure composed of equiaxial β grains without any precipitate was detected after solution treatment at 1,100 °C/4 h and 1,200 °C/2 h. In addition, the lattice parameters of β phase increased gradually with the increasing of solution temperature. Hardness and room temperature compression test were performed using Vickers hardness tester and universal testing machine. The results showed that the alloy subjected to solution treatment exhibited a high level of hardness value, with the minimum value of 367HV; the alloy subjected to solution treatment at 800 °C/2 h exhibited high compressive yield strength, with the maximum value of nearly 1,650 MPa; the alloy subjected to solution treatment at 1,100 °C/2 h and 1,200 °C/2 h exhibited excellent compressive ductility (The specimens were not crushed, the strain δ > 50%) with high compressive yield strength (YS > 1,100Mpa).