Physicomechanical and adhesion characteristics, specific surface energy of vacuum coatings formed on high-speed steels of the P6M5 type subjected to processing at cryogenic temperatures are investigated. The structural transformations occurring in vacuum coatings formed on steel substrates with subsequent processing at low temperatures were studied. A change in the tribological characteristics of titanium nitride coatings during subsequent processing in a cryogenic liquid is shown.
Journal section: TECHNOLOGIES
This paper deals with Numerical Simulation to analyse the behaviour of residual stresses in welding pipe. This work aims to develop a validation model for the simulation of phase changing after welding in multi-pass welds using a hardness test and compare the results with numerical simulation. The simulation considers the local microstructure properties changes due to the thermal welding cycles. Finally, the challenge of this work is the welding of dissimilar materials, where a calibrated model will be applied and validated to predict the effect of welding residual stresses in welding pipe. A further aim is to develop a new procedure to simulate a typical welded pipe process.
The article concerns the problem of selection the most suitable method of calculating manufacturing time of products created in Design To Order approach. Product customization is becoming an increasingly important aspect of many companies. The basic problem of this type of production is the determination of time needed for delivery to the customer. Also estimating the duration of individual production operations can be a significant problem for production planning. Without these values, it is not possible to conduct the production planning process without mistakes and faulties. The use of common worktime calculation methods is often impossible or inadequate from the point of view of the workload involved during production preparation. The article presents the results of practical research in an enterprise, determining the most effective method of calculating production time in Design To Order approach.
Production levelling, also referred to as production smoothing (jap. Heijunka), is an effective method for reducing unevenness in the production process and maintaining better control over stock levels. It helps keep production at a steady pace and ensure the desired level of flexibility. The authors present a study aimed at developing a method for planning the inflow of products from the production process, intended to be used in the scheduling of levelled production. Focus has been put on finding the right combination of lot size and production interval which, assuming certain input parameters (order size and placement rate, initial stock levels), yields the best outcome in terms of timely/untimely order fulfilment and minimum and maximum stock levels.
While many modern industries are tending to use UFV (unmanned flying vehicles) in a near future, there are also many problems of yet unknown procedures to make possible the usage of such UFV. In a current age of aviation development there is an approach of FRA (free routing area) utilization to support growing congestion of many flying vehicles in air space. From our prospective, those manufacturing implementing “Industry 4.0” ideas are expected to use UFV to support supply chains. Hence, both problems and solution approaches to support many aircraft in airspace and to control airspace congestion within safe boundaries can be used also in a local scale of UFV supported manufacturing. This research paper is focused on problems and ability to build routes within FRA and analysis of possible use of known approaches to solve similar problems of modern automated manufacturing.
In this this research work, the results of investigation corrosion condition of the steel pipe system for the heated water transportation and distribution after long years of exploitation are presented. The analysis was performed on the pipe segments after their removing i.e. cutting. Thirty segments were taken for inspection. The outer and inner surface of the pipes was inspected. Plan for inspection was prepared basing of the literature revue and personal experience. All specimens were visually inspected. For the investigations of pitting corrosion measuring of depth of pits was done. Performed investigations confirmed that general corrosion, uniform and no uniform is represented on the pipe from the outer side. From the inner side are presented different types of pitting: narrow, shallow, and elliptical and corrosion under layer. Performed investigation confirmed that the most dangerous for the piping systems is corrosion on the outer sides of the pipes which their perforation. Measurement of the pits deepness showed that pitting corrosion is not so danger because pits deepness is in the range between 0.18-1.24 mm which is negligible compared with the pipes wall thickness.
Research and justification of the possibilities, relevance and correctness of the monitoring and correction of the strategy, diagnosis of the prospects of its further use on industrial enterprisespg(s) 400-403
It is established that the main activities include: exercising control over the rational use of resources; reducing the cost of using and maintaining outdated equipment; increasing of production capacity; upgrading of equipment; improvement of production technology; production of unique products and improvement of their quality; diversification; automation of the production process by eliminating manual labor; reduction of pollutant emissions, search for new sources of raw materials; rational use of working capital and fixed assets. It is noted that marketing directions in the process of monitoring and adjusting the strategy, diagnostics and finding prospects for its further use include a set of actions concerning: exploring new markets for products; use of discount system for goods and services; application of modern pricing methods; product updates; production of new products according to existing orders; new methods of product promotion; improving customer service. The financial directions in the process of monitoring and adjusting the strategy, diagnostics and finding prospects for its further use are determined, they are aimed at providing the process of development and implementation of the IA strategy with sufficient financial resources, correlation of the planned effect with the achieved, estimation of the amount of expenses for carrying out research works, development technologies, their introduction into production, production of new products, its supply, search for consumers. The justified use of financial directions in the process of monitoring and adjusting the strategy, diagnostics and finding prospects for its further use allows to create some methods of protection from risks impact, to improve financial activity of the enterprise, to rise the effectiveness of IA organization, to increase sales volumes.. The factors of influence on the development of innovation strategy and the development of innovation activity of industrial enterprises are suggested.
The types of entrepreneurial activity and form of enterprises are investigational. Described business system and her elements. Sequence of executions and in accordance with principles which provide the acceptance of effective administrative decisions aimed at realization of investment strategy of industrial enterprises is offered. Tasks which must be the strategies of industrial enterprise taken into account in the process of choice are certain. The stages of life cycle of industrial enterprises are set from the period of “birth” to the period of “expansion”. Expediency of different forms of strategy of diversification of investment activity of industrial enterprises is reasonable.
Synthesis of the magnetic adsorbent based of graphene oxide and ZnO nanoparticles for environmental applicationspg(s) 395-396
In this study Fe3O4-ZnO and GO-Fe3O4-ZnO are synthesized as photocatalysis for decomposition of of methyl orange (MO) as organic dye pollutant model. The XRD results show that the prepared nanocomposites contain the modified GO with cubic structure of Fe3O4 and hexagonal wurtzite structure of ZnO nanoparticles. The photocatalytic results show that the degradation of MO using both of the synthesized photocatalysts enhances with respect to the time and weight fraction. The removal efficiency of MO using GO-Fe3O4-ZnO at each concentration and irradiation time is more than that of Fe3O4-ZnO.
The structure formation features of the alloy Zr41,2Ti13,8Cu12,5Ni10Be22,5 during the casting in the metal mold and the following heating amorphous ingotspg(s) 392-394
The structure formation features of the bulk glass alloy Zr41,2Ti13,8Cu12,5Ni10Be22,5 under conditions of melt casting in a copper mold and subsequent heating of amorphous ingots, are studied. It is shown that for certain parameters of the model (the thickness of the ingot and its heating rate), the main contribution to the total crystallized volume fraction passes from frozen crystal growth processes to the processes of nucleation and growth of new crystals. Regardless of the dominant crystallization process during heating, amorphous ingots of the Zr41,2Ti13,8Cu12,5Ni10Be22,5 alloy are crystallized to form a coarse crystalline structure.
Novel hybrid polyethersulfone membranes modified with polyvinylpyrrolidone and Ag/titanate nanotubespg(s) 388-391
In this work, the influence of addition of polyvinylpyrrolidone (PVP, 10kDa, 1-4.8wt%) and Ag-modified titanate nanotubes (Ag/TNTs, 0.1wt%) on physicochemical and transport properties of polyethersulfone (PES) ultrafiltration membranes was studied. The membranes were prepared via wet phase inversion method using N,N-dimethylformamide (DMF) as a solvent and water as a non-solvent. The Ag/TNTs nanocomposite was obtained via photodeposition method using AgNO3 as a precursor. It was found that the addition of PVP into the casting dope affected the cross-section structure of the membranes and their surface topography. The presence of PVP improved the dispersion Ag/TNTs agglomerates in the membranes structure. A positive influence of the introduction of the nanocomposite into the membranes matrix on their permeability was also proved.
Experimentally verified mathematical model of the polymer plasticization process in the injection moldingpg(s) 382-387
The mathematical model of the polymer plasticization in the reciprocating screw injection molding machine is presented. According to the mathematical model, a computer program was developed. Based on the computer program, simulation studies of the injection molding process were conducted. Next, the experimental studies, evaluating the theoretical model from the accuracy and usefulness point of view, were carried out. Important output quantities, such as the temperature and pressure profiles, the power demand by the screw, the torque on the screw and the screw rotation time were measured. The studies were performed on a specially made
research office. The simulation results were compared with the experimental data measured for the most popular polymers and different operating parameters of the injection machine. The experimental studies have indicated the need to introduce some corrections to the mathematical model. Several modifications have been made to the model, related to the methods of stress determining in the polymer layer. Finally, the output characteristics of the plasticization process in the injection molding are now correctly determined by the model with an average error less than 10%.