Effective Technical Solutions Research Articles

РЕСУРСО- И ЭНЕРГОСБЕРЕГАЮЩИЙ СПОСОБ ПОЛУЧЕНИЯ ФТОРОВОДОРОДА И ФТОРАНГИДРИТА

An ecologically and economically effective technical solution has been developed for the production of hydrogen fluoride and fluorine hydrite by using fluorosulfonic acid in the decomposition technology of fluorspar. The stages of the technology of obtaining hydrogen fluoride and fluorine hydrite are shown: obtaining fluorosulfonic acid itself, decomposition of calcium fluoride with fluorosulfonic acid and hydrolysis of calcium fluorosulfonate with water vapor to form fluorosulfonic acid, recycled, hydrogen fluoride and fluorine hydrite. Experimental data have shown the promise of this technology.

An Approach to the Restoration of Metal Water Conduits of Hydraulic Structures

Issues related to the search for effective technical solutions for the restoration of pressure metal water conduits of hydraulic structures are considered. Findings demonstrating the relevance of using polymer composites as external reinforcement systems for restoration are presented. Recommendations on the integration of technologies for the restoration of water conduits are given.

Послідовність виконання робіт при реконструкції з надбудовою мансарди

У статті описані основні принципи організації роботи при надбудові мансардного поверху в житлових будівлях, послідовність виконання робіт, визначення затрат праці та проектування календарного плану.

Improving the geometric topology of geothermal heat exchangers in oil bore-holes

A review has been conducted of key trends in the development of geometric topology of geothermal heat exchangers. Authors proposed approaches to improving the designs and network structures for heat-transfer media circulation in the bottom-hole space of oil-and-gas reservoirs. Four geometric topologies of geothermal heat exchangers have been analysed: І–ІІ – rectilinear vertical smooth and finned pipelines; ІІІ–IV – a cluster in the form of a set of smooth and finned single-pipe elements, representing a figure of “squirrel wheel” or “meridian sphere” type. It is shown that the most effective technical solution, which ensures the increase in the coefficient of performance (COP) of bore-hole geothermal systems is finning the heat exchanging pipes. For the heat exchangers of І–ІІ type, the calculated increase in COP in comparison with smooth pipes is 40%, and for ІІІ–IV type – 95%. The key parameters influencing the COP of a geothermal heat exchanger are: the radius of fluids draining out during the heat exchange process, the radius of pipelines with circulating heat-transfer medium, the diameter of a cluster heat exchanger, the heat exchange area, the parameters of rocks thermal resistance in the bottom-hole zone of heat-receiving.

Implementation of linear, double-linear, and nonlinear fatigue damage accumulation rules for fatigue life prediction of offshore drilling top-drive tie-rods

The offshore oil and gas industry has been exposed to major challenges over the last decade, particularly demanding cost cuts and more effective technical solutions. Predictive systems and remaining life assessments for both machine and structural components are known to be one of the core areas that has gathered much attention lately. This paper focuses on multiaxial fatigue that is a problem in number of engineering structures and equipment. The ability to properly assess and quantify multiaxial fatigue of offshore equipment and structures has major benefits for owners of engineering assets both in terms of technical and safety integrity. Traditionally, Palmgren-Miner’s damage rule is used for life estimation involving multiaxial fatigue due to its ease of use. There are however some known shortcomings with Palmgren-Miner’s rule namely: it does not consider the loading sequences. This for instance can result in overestimation of fatigue life in scenarios where stress amplitudes are decreasing, and moreover underestimation of fatigue life in scenarios where stress amplitudes increase. This research work thus involves closely studying the application of Palmgren-Miner’s linear damage rule, Manson’s double linear damage rule, and Subramanyan’s non-linear damage rule for the purpose of enhancing the predictability of damage as well as accuracy of fatigue life assessments. Each of these techniques were applied for tie-rods of an offshore drilling top-drive having a known stress history. The loading histories were provided by a drilling company. The torque and axial force values are transformed to stress components for the corresponding critical spots. The “rainflow” counting technique is applied to the obtained stress histories and the mean stress effect is considered for the damage accumulation calculations. The fatigue life prediction of the three models are justified and discussed. This research work was aimed at contributing towards the utilization of more robust fatigue life estimation techniques such as Manson’s double linear damage rule and simplified non-linear damage rules which capture the true nature of the fatigue that equipment’s are subjected to, and thus to improve the reliability of the fatigue life predictions.

A Game-theoretic analysis on the economic viability of mobile content pre-staging

The rapid growth of demand for data in wireless communications has driven the mobile service carriers and the research community to seek both effective technical and alternative solutions to the data demand problem. One particular solution, content pre-staging, tries to push content as close to the mobile device as possible in order to lower demand at peak times. Assuming the interesting case that mobile device storage could be made available as part of the mobile carrier’s system capacity either directly by the end user or indirectly by the carrier, this paper investigates the potential economic impacts on the mobile service business and various stakeholders of content pre-staging. We explore the economic implications of content pre-staging by modeling the interplay among the mobile carrier, end users, and the content provider in a game theoretic framework. The carrier designs pricing mechanisms to affect the behaviors of the content provider and end users for the purpose of profit maximization. In particular, two prices are introduced, the price charged to the content provider to pre-stage content on mobile device storage, and the monetary reward to compensate users for the usage of their mobile device storage. Although the individual incentive of the carrier is not necessarily aligned with social incentives, the welfare analysis of content pre-staging shows that the practice improves social welfare by increasing network efficiency. Localizing content increases the overall profitability of mobile service business which is positively related to the relevance of the pre-staged content. The carrier’s pricing mechanisms determine the manner in which the increased profitability of the business is shared by various interested parties. While the carrier may design prices strategically to retain a larger share of the increased profitability, content pre-staging can benefit all the three parties in the game, i.e., the carrier gains in saved capacity and new revenue, users gain QoE, content, and financial rewards for sharing mobile device storage, and the content provider gains in increased revenue from increased content access.

ПЛАНУВАННЯ ЕКСПЕРИМЕНТУ З ДОСЛІДЖЕННЯ ЧИННИКІВ, ЩО ВПЛИВАЮТЬ НА ТЕРМІЧНИЙ ОПІР ОГОРОДЖУВАЛЬНИХ КОНСТРУКЦІЙ ПРИ ЇХ ТЕРМОМОДЕРНІЗАЦІЇ

Today, in the absence of sufficient quantities of fuel, the reduction of energy consumption in the residential sector is important for Ukraine. This will not only save the resources spent on heating residential buildings, but will also reduce the harmful impact on the environment. The modern way of Ukraine in the direction of energy saving increases the requirements for heat-protective structures, increasing the value of thermal resistance. Therefore, it is necessary to improve them. It is important to pay attention to the sites of adjoining fencing structures of the building, as there are so-called "bridges of cold". Studies have shown that up to 30% of heating energy is lost through such sites. The appearance of "bridges of cold" is primarily due to the materials used and the design features. Modern normative documents do not provide effective technical solutions for reducing heat losses due to thermal heterogeneity of external enclosing structures of buildings. In connection with this, it is necessary to develop design solutions of thermal insulation systems of the adjacent nodes, which will reduce the probability of the occurrence of "bridges of cold" and in turn will increase the energy efficiency of the building. The characteristics of the heat-insulating material play an important role in increasing the thermal resistance of the structure. Today, there are a variety of heat-insulating materials that differ in their properties and cost. In view of this, it is necessary to select the most optimal parameters of the thermal insulating structure for the adjacent units, which would meet the regulatory requirements. For this purpose, the influence of the thermal insulation parameters on the thermal resistance of the construction on the basis of the two-factor experiment was carried out. From the parameters that have the greatest influence on the thermal resistance, the thickness of the heat-insulating material and its density are chosen.

Increase of Efficiency of Extinguishing of Rock Dumps on the Surface of Coal Mines

The most effective technical solutions have been those that provide for the supply of substances used for extinguishing to the combustion zone of the rock dump. When quenching rock on the rock dump is proposed injection (blowing) in a dry extinguishing agent, represented by crushed vermiculite (hereinafter referred to as the extinguishing agent), in pure form or in a mixture with alkaline substances. The problem of developing methods of extinguishing rock dumps, characterized by low cost and high efficiency, in the absence of additional environmental pollution is very relevant. The technology of suppression of waste rock dumps include the injection of suspended particles of vermiculite in contrast to the clay slurry or solution (suspension) of antipyrene. This allows to penetrate into the surface layer of the middle and upper part of the blade and insulate its lower part with non-combustible material.

GENERALIZED METHOD OF DESIGNING UNMANNED REMOTELY OPERATED COMPLEXES BASED ON THE SYSTEM APPROACH

Self-propelled underwater systems belong to the effective means of marine robotics. The advantages of their use include the ability to perform underwater work in real time with high quality and without risk to the life of a human operator. At present, the design of such complexes is not formalized and is carried out separately for each of the components – a remotely operated vehicle, a tether-cable and cable winch, a cargo device and a control and energy device. As a result, the time spent on design increases and its quality decreases. The system approach to the design of remotely operated complexes ensures that the features of the interaction of the components of the complex are taken into account when performing its main operating modes. In this paper, the system interaction between the components of the complex is proposed to take into account in the form of decomposition of “underwater tasks (mission) – underwater technology of its implementation – underwater work on the selected technology – task for the executive mechanism of the complex” operations. With this approach, an information base is formed for the formation of a list of mechanisms of the complex, the technical appearance of its components is being formed, which is important for the early design stages. Operative, creative and engineering phases of the design of the complex are proposed. For each phase, a set of works has been formulated that cover all the components of the complex and use the author's existence equations for these components as a tool for system analysis of technical solutions. The perspective of the scientific task of the creative phase to create accurate information models of the functioning of the components of the complex and models to support the adoption of design decisions based on a systematic approach is shown. The obtained results form the theoretical basis for finding effective technical solutions in the early stages of designing remotely operated complexes and for automating the design with the assistance of modern applied computer research and design packages.

THE CURRENT STATE OF RESOURCE AND ENERGY SAVING IN THE TECHNOLOGY OF PRODUCTION OF CARBON-BASED FILLER OF ELECTRODE PRODUCTS (REVIEW)

Advantages of application of electrocalciners to production of carboniferous fillers of the electrode industry are considered. The analysis of designs of electrocalciners is made, their advantages and disadvantages are given, and also the physical processes happening in them are described. The critical analysis of theoretical and experimental methods of research of physical processes at heat treatment of carboniferous materials in electric furnaces is carried out. It is shown that for development of resource-power effective technical solutions on modernization of the production technology of fillers in electrocalciner it is expedient to combine methods of mathematical modeling with separate pilot studies on the industrial equipment. It is shown that industrial using of resource-power effective technical solutions on modernization of the production technology of fillers in electrocalciner allows to receive the following indicators of efficiency: for anthracite calcinating electrocalciners the resource of work increased from 1 month to 6 months, and specific expenses of the electric power decreased by (50–100) kW·h/t; for graphitizing of oil coke electrocalciners the resource of work increased from 2 days till 1 year, and specific expenses of the electric power decreased more than by 1600 kW·h/t in comparison with classical technology. Bibl. 37, Fig. 7, Tabl 1.

Technical mitigation to reduce marine mammal bycatch and entanglement in commercial fishing gear: lessons learnt and future directions

Fisheries bycatch is one of the biggest threats to marine mammal populations. A literature review was undertaken to provide a comprehensive assessment and synopsis of gear modifications and technical devices to reduce marine mammal bycatch in commercial trawl, purse seine, longline, gillnet and pot/trap fisheries. Successfully implemented mitigation measures include acoustic deterrent devices (pingers) which reduced the bycatch of some small cetacean species in gillnets, appropriately designed exclusion devices which reduced pinniped bycatch in some trawl fisheries, and various pot/trap guard designs that reduced marine mammal entrapment. However, substantial development and research of mitigation options is required to address the bycatch of a range of species in many fisheries. No reliably effective technical solutions to reduce small cetacean bycatch in trawl nets are available, although loud pingers have shown potential. There are currently no technical options that effectively reduce marine mammal interactions in longline fisheries, although development of catch and hook protection devices is promising. Solutions are also needed for species, particularly pinnipeds and small cetaceans, that are not deterred by pingers and continue to be caught in static gillnets. Large whale entanglements in static gear, particularly buoy lines for pots/traps, needs urgent attention although there is encouraging research on rope-less pot/trap systems and identification of rope colours that are more detectable to whale species. Future mitigation development and deployment requires rigorous scientific testing to determine if significant bycatch reduction has been achieved, as well as consideration of potentially conflicting mitigation outcomes if multiple species are impacted by a fishery.

The development of an operative diagnostic method of the limiting technical condition of the sectional pump hydraulic balancing unit

In the conditions of underground kimberlite mines operated by PJSC ALROSA, the main reason for the premature achievement of the limit technical condition by the sectional pump is the intensive abrasive destruction of its basic parts, namely, the shaft, impellers and, in more rare cases, the discharge covers. Mechanical destruction of the above-mentioned parts usually occurs as a result of the operation of a sectional pump with a critical axial displacement of the rotor (2.8 ÷ 3 mm) in the direction of suction, since in such an emergency position of the rotor there is a tribocontact between it and the pump housing elements, which after some period of time leads to serious consequences. Practice shows that in the conditions of underground kimberlitic mines of the Company application of the sensor of measurement of rotor axial shift of the sectional pump intended for identification of growth of the size measured by it to critical values is the effective technical solution only for some period of time. Frequent failures and a certain complexity of reconfiguration of this control and measuring device became the main reasons for reducing the correctness of the results issued to them. Thus, we state that the development of a technique for the identification of the rotor critical axial shift of the sectional pump, the use of which should be an alternative to the use of the above mentioned sensor, is an urgent scientific and practical task at the present time. The solution of this problem will increase the durability of the basic expensive parts of the sectional pump, as well as the level of industrial safety in underground mining of kimberlite ore. This research paper describes in detail the complex of diagnostic features of the sectional pump in critical axial displacement of the rotor, whose introduction into production will allow with a high degree of probability to increase the operational reliability of sectional pumps of drainage systems of underground kimberlitic mines of the PJSC ALROSA.

Improving the geometric topology of geothermal heat exchangers in oil bore-holes

A review has been conducted of key trends in the development of geometric topology of geothermal heat exchangers. Authors proposed approaches to improving the designs and network structures for heat-transfer media circulation in the bottom-hole space of oil-and-gas reservoirs. Four geometric topologies of geothermal heat exchangers have been analysed: І – ІІ – rectilinear vertical smooth and finned pipelines; ІІІ – IV – a cluster in the form of a set of smooth and finned single-pipe elements, representing a figure of “squirrel wheel” or “meridian sphere” type. It is shown that the most effective technical solution, which ensures the increase in the coefficient of performance (COP) of bore-hole geothermal systems is finning the heat exchanging pipes. For the heat exchangers of І – ІІ type, the calculated increase in COP in comparison with smooth pipes is 40%, and for ІІІ – IV type – 95%. The key parameters influencing the COP of a geothermal heat exchanger are: the radius of fluids draining out during the heat exchange process, the radius of pipelines with circulating heat-transfer medium, the diameter of a cluster heat exchanger, the heat exchange area, the parameters of rocks thermal resistance in the bottom-hole zone of heat-receiving.

Falls from a height at construction sites caused by incorrect use of collective protection measures

This article presents an analysis of accidents caused by falls from a height examined by the National Labour Inspectorate in 2013-2017. Accidents have been analyzed taking into account irregularities related to the use of collective protection measures. 121 events, which had occurred due to the lack or non-use of collective protection measures, were selected for detailed study. The article discusses 10 typical worksites and selected activities performed when accidents took place. It presents a statistical analysis of accidents caused by various irregularities in the use of collective protection measures and it presents descriptions of selected events. Using collective protection measures against falls from a height in the construction industry is an effective preventive technical solution, which does not physically burden workers and does not cause their discomfort at work. Therefore, legal provisions give them priority over personal protective equipment.

The house of safety: A novel method for risk assessment including human misbehaviour

In this paper, a novel method called House of Safety (HoS) for the risk assessment during the design of machineries is proposed. The approach supports the integration of the human behaviour of the workers aiming to assess the risks arising from human misbehaviour in the man-machine interaction. Modifying the well-known “house of quality”, the basic design tool of the management approach known as Quality Function Deployment (QFD), the risk priority number (RPN) of the risks due to the human misbehaviour and their inter-correlated domino effects are evaluated considering the severity, detectability and occurrence criteria that are weighted using the Analytic Hierarchy Process (AHP). Thereafter, the safety protective devices, that are most effective to manage the risks due to the human behaviour in the man-machine interaction, are selected on the basis of the RPN and their correlated effectiveness. The proposed approach is applied to an ordinary maintenance activity on a fruit and vegetable hot refiner. The effectiveness and usefulness of the original methodology for the selection of the most effective technical solutions to mitigate the risks due to the human misbehaviour are presented in the provided case study.

Analysis and assessment of the risk of loss of stability of the car at the radius of the round-off of the Congress to determine the speed

When applying innovations or repeated effective technical solutions of the road sector, it is recommended to use the risk of damage assessment in the project documentation. This gives an opportunity for expert organizations reasonably give a positive conclusion on the project documentation. The method of calculating the risk of harm in the design of the junction to the road, taking into account the basic works of V.V. Stolyarov. A typical example of the study based on the assessment and calculation of the risk of harm is considered. The study is carried out taking into account the Federal law «on technical regulation» and article 15, paragraph 6 of the Federal law «Technical regulations on the safety of buildings and structures» based on the assessment of the risk of failure to achieve the goals and requirements of the Federal law. The probability-theoretical approach, in particular the risk theory, allows to increase safety, comfort and convenience of movement by changing the geometric and transport and operational indicators of roads. The parameters of the curve (radius of curve), the coefficient of adhesion, and the longitudinal slope affect the probability of the car’s stability loss on the radius of the carriageway rounding associated with the car skidding or tilting. This procedure is designed to determine and reduce to the acceptable risk the probability of occurrence of road transport facilities due to imperfections of road conditions (rounding parameters). Technical regulation, risk assessment, damage assessment, risk theory, operations, life cycle, quality management, standards, probability approach, road management.

Diagnosing and Forecasting the Prospects for the Development of the Global Container Transportation Market

The main trend in the development of domestic and global transport is the rapid growth of container traffic, which meets the requirements of a market economy. They become an integral part of the national or international commodity distribution and warehouse system, which ensures the uninterrupted delivery of various products to the trading network and goods of industrial and technical purpose to industrial production. According to experts from many countries, such transportation should embody the freight transport service of the XXI century. The growing demand for container transportation in Ukraine and in the world by manufacturers and consumers of various types of products and services requires the search for effective technical, technological and organizational solutions.
 A promising direction of container transportation is a unified system of container terminals (CT) created on the traffic routes of container-transportable cargoes. In addition, the problem of improving the quality of service due to the increased competition from other categories of transport is of particular importance.
 In a market economy and industry restructuring, there is a need for a new approach to address these issues, which would allow for reducing the cost of container ports and increasing their attractiveness for users. The importance of addressing these issues for the container transport industry determines the importance of this study.
 Topical problems of the current state and developments of the global market of container transportations are discussed. The largest container ports in the world are determined using the data on their throughput and the dynamics of the total capacity of container vessels in the maritime trade. The data on operation of the largest shipping companies in the world are analyzed. Index Baltic Dry is proposed for forecasting the global market of container transportations, which measures traffic volumes of bulk carriers; it is proposed to create support container terminals for the largest companies that would represent a single system of alliances rather than an isolated transport and logistics company.

Effectiveness of dimethyl disulfide (DMDS) for management of root-knot nematode in protected tomatoes in southern Europe

The root-knot nematode (Meloidogyne spp.) is a major threat for protected tomato crops, with Meloidogyne incognita, Meloidogyne javanica and Meloidogyne arenaria being the most frequent species in southern Europe. This problem is critical for EU tomato growers, as effective fumigants have lost their registration and effective technical solutions are not available, except through national derogations. This paper gives a review of the efficacy of the new fumigant dimethyl disulfide (DMDS) against Meloidogyne spp. in protected tomato in southern Europe. A total of seven trials were carried out during 2012-2014 in Italy (3), Spain (2) and Greece (2) against root-knot nematodes, under conditions of medium-high levels of nematode infestation. The fumigant Accolade/Paladin™ 94.1% EC (Arkema) was applied in drip chemigation, at 300 and 400 L ha-1 and compared with 1,3-dichloropropene (1.3D; 120-200 L ha-1 formulated product) and an untreated control. Before application, soil and chemigation lines were covered with virtually impermeable film (VIF). Twenty-one days after fumigation (14 days covered with VIF and 7 days left uncovered for soil aeration), tomato seedlings were transplanted. Evaluations of nematode infestations of the roots and of crop yield were made. The gall severity index (GSI) according to a 0-10 scale showed medium-high root damage at harvest, with an average index of 5.3 observed in the untreated control. DMDS gave effective control of Meloidogyne spp. at both rates of application: GSI of 1.0 with 400 L ha-1 and 1.3 with 300 L ha-1. The standard treatment 1.3D (several tradenames) gave an average GSI of 1.4. DMDS greatly increased tomato yield when compared with the untreated control: by 62.7% for DMDS 400 L ha-1 and 55.1% for DMDS 300 L ha-1, whereas the average yield increase of the standard 1,3D was 61.5%. These results confirm the excellent efficacy of DMDS against root-knot nematodes in protected tomatoes.

Optimal Node Placement and Resource Allocation for UAV Relaying Network

Utilizing unmanned aerial vehicle (UAV) as the relay is an effective technical solution for the wireless communication between ground terminals faraway or obstructed. In this letter, the problems of UAV node placement and communication resource allocation are investigated jointly for a UAV relaying system for the first time. Multiple communication pairs on the ground, with one rotary-wing UAV serving as relay, are considered. Transmission power, bandwidth, transmission rate, and UAV’s position are optimized jointly to maximize the system throughput. An optimization problem is formulated, which is non-convex. The global optimal solution is achieved by transforming the formulated problem to be a monotonic optimization problem.

New Type of Cutoff Tools and Hard-Alloy Multifaceted Unresharpenable Plates for Their Equipping

Purpose: This paper deals with the sphere of designing and manufacture cutting tools in designing with assembled parting-off cutters equipped with multifaceted unresharpenable plates (MUP). Methodology: Lathe tools are the most popular among cutting tools and one of the ways of their improvement is to turn to assembled structures with mechanical fixing quickly replaceable multifaceted unresharpenable plates. In the sphere of developing assembled parting-off cutters the most effective technical solutions where found by foreign firms: Sandvik Coromant, Iscar, Horn, Taegu Tec, Mitsubishi and others. The analysis of these constructions show that 2 principles realized here: 1) side fixing of plate to the head of holder body 2) side installation with plate fixing by tacks ore elastic clamps. In the first case multiage plates are used and in the second case one and two edge ones. The simplest variant – is to set standard MUP on lateral side and form. However, such variant is not acceptable as considerable radius of mating lateral faces MUP (r≥ 0,2 mm). To eliminate radius r is possible by making flats m or ark grooves with radius rb at the tap of MUP. Result: The system of plates of new type is developed – lateral multifaceted unresharpenable plates (LMUP) created basing on standard hard alloy plates. Increase the depth of cutting of from 6,1 to 16,5 mm, relative expense of hart material alloy on one cutting plate edge in 1,1 – 2times superior in mass to the mass base plate. Originality: New type of cutting plates was developed – lateral multifaceted unresharpened plates (LMUP), their differential feature is the availability of sharp cutting edges on side faces made by additional sharpening along the tops of their flats or arc grooves. These plates of decoding to the Russian Federation patent for the invention № 2366542. Practical value: Suggested LMUP even in minimum trihedral execution are considerably superior to in size-mass characteristics to multiedge bas plates of leading world producers: Sandvik Coromant, Iscar, Horn, Taegutec, Mitsubishi and others which allows to recommend then for wide application.