Hazards identification is essential step in framework of occupational health & safety (OH&S) management system. The task of spruce wood sanding with hand-held power belt sander is considered as a significant resource of exposure to wood dust. Dust from spruce wood is hazard that can cause negative health effects such as asthma and chronic bronchitis. A dust collection box is a commonly used technical measure for reducing exposure to wood dust for this task in practice. The objective of this pilot study was to evaluate the effectiveness of commercially available dust collection box at reducing exposure to wood dust during the task of sanding spruce wood using hand-held power belt sander. Laboratory experiment involved sanding spruce planks (250 mm × 50 mm × 500 mm) in longitudinal direction using belt sander (Bosch, PBS 75 A) with 120 grit sanding belt. Spruce dust mass concentrations were sampled using an aerosol monitor (TSI Inc., DustTrak DRX 8533) in the breathing zone of operator. Inhalable and respirable dust concentrations were both significantly lower (P < 0.0001) when dust box was attached to belt sander compared with sander without a dust box. Results from this pilot study indicate that dust collection box is efficient technical measure for decreasing exposure to aerosol mass concentration during sanding spruce wood with hand-held belt sander.
The development of oil fields at a late stage is characterized by a number of complications that determine the features of the operation of downhole equipment in pumping units. The use of electric-centered pumps in wells with intervals of increased curvature intensity requires a preliminary analysis of the possibility of lowering and operating the equipment at design depths. The aim of research is development of a new approach to evaluation the stress-strain state of pumping equipment, taking into account the features of the inclinometry of the intervals of its location. The analysis of the results of previous studies of the influence of the well profile on the operation of pumping equipment and recommendations for ensuring its performance is carried out. Given the possibility of operating equipment with limited levels of deformation, a mechanism is proposed for evaluation its stress-strain state using software products based on the finite element method. The reliability of the results is confirmed by comparison with those obtained in the course of analytical studies performed according to a previously tested methodology. Application of the proposed approach will allow to assess the level of deformation of individual elements of the equipment installations, taking into account their design features and the results of inclinometry.
In this work was established that serial traditional hardfacing materials based on the Fe-Cr-C system are not effective for improvement of abrasion resistance of elements of equipment for production of bricks, solid fuel briquettes and for restoration of augers, due to the fact that this equipment works at significant specific and cyclic loads. Features of the coarse-grained structure of Fe-Cr-C based coatings leads to intensive abrasive wear. The aim of this study was to increase a durability of that equipment by using of flux cored electrodes with reaction components of Ti, Cr, Mo, B4C and their combinations to provide synthesis, which leads to fine-grained structure of refractory borides and carbides and their solid solutions with increased hardness. Structure of the hardfacing coatings were investigated by method of metallography, scanning electron microscopy (SEM), electron backscatter diffraction (BSD) mode and energy dispersive X-ray spectroscopy (EDS). Temperature dependences of equilibrium phase amount of the hardfacing materials were calculated by the CALPHAD technique, using JMatPro software. It was investigated that the offered materials are characterized by higher wear resistance at high specific and cyclic loads in comparison with serial production high-chromium hardfacing materials (Lastek, ESAB, Paton IEW). It was established that the abrasion wear resistance at high specific and cyclic loads depends mostly of formation of the structure of hardfacing material, and not the hardness. Also, using of powders of pure metals and their combination as reaction mixture for FCAW leads to fine structure which contains of refractory borides and carbides and their solid solutions.
One of the ways to increase natural gas production is to conserve and/or intensify existing wells with their subsequent development. They are characterized by a high content of highly mineralized water, which leads to an increased risk of hydrate formation and internal corrosion. The issue of the formation of gas hydrates in industrial pipelines, which is a major problem for the exploitation of industrial gas pipelines, requires considerable attention to be made to exclude emergency situations. The main task of the study – to determine the effect of hydrates on the corrosion of the pipeline in order to prevent emergencies. A technique for studying the effect of hydration on the corrosion of pipelines has been developed. The combined analysis of the corrosion behavior of pipe material in aggressive media of chloride type was done. According to the results of corrosion-mechanical tests, regularities of joint action of mechanical stresses, concentration of chlorides and hydrate formation on the speed and localization of corrosion processes are established.
Condition monitoring and fault diagnosis of engineering systems are critical for the stable and reliable operation in various areas as mobile technology (primarily agricultural, forestry, mining and construction machinery), railways, airlines and large fleets. Thus, to achieve a satisfactory level of reliability for the life of a machine, proactive maintenance strategy is the only key. This means that the application of classical reliability methods suitable for components with sudden failures can be complemented by technical diagnostic methods which have the potential to provide the information about the system condition. In this article we focus on the diagnostic signal related to the used oil – tribodiagnostic measures and is an interesting theoretical item related to the evaluation of the quality of lubricants in the aspect of operation. This is because the oil is in direct contact with single parts of the assessed technical systems. Results tests were reviewed and derived from various parameters of lubricants and their limits that highlight the condition and state of the lubricants under varying categories which include, physiochemical, elemental (wear), contamination and additive analysis.
The aim of the research was to verify a new method of measuring the colour of wood. The method was designed to automate wood colour measurement. In the experiments birch wood was used, which was heat treated with saturated water steam. Nikon D3200 camera was used in conjunction with the MATLAB program to implement the method. The assessments were conducted in the colour space of CIE L* a* b*. The measured values confirmed the decrease in lightness from natural to thermally modified wood. The trends of the colour values a* and b* were the same as those reported by the authors who conducted experiments with birch wood. Differences were found in the magnitude of the measured chromatic component a* values. It will be necessary to verify the above facts and determine the reasons for these differences by measuring the colour of other wood species.
In the period of shortage of gas supply, special attention is given to reducing the supply of gas to its consumers, that is, their complete and uninterrupted gas supply. Increasing gas losses associated with technological transportation costs, in particular caused by gas flow instability and frequent changes in gas transmission network operating modes. Considering losses due to unreliability of gas pumping is one of the important tasks of gas supply optimization. The purpose of the study is to develop an optimization mathematical model that will simultaneously take into account the factors of reliability and minimum lossesIn the general case, the optimization calculations of the modes of operation of the main gas pipelines are intended to solve three main problems: determining the maximum productivity, calculating the optimal mode with a given productivity and choosing the optimal strategy, the development of the pipeline. On the basis of approaches of simulation modeling of complex systems, a multi-parameter mathematical model of gas supply process optimization was developed. It is shown that a comparative analysis of the forecast and actual indicators of the operating modes of the plunger gas pumping unit shows their satisfactory convergence. The performance of the compressor operation period in the process of injection according to the forecast deviates from the actual value for the whole period of operation of the plunger gas pumping unit in 2016 by 2.98%. The optimization problem of gas pumping planning is considered, taking into account the expected losses, on the basis of which the transfer of the controlled system from the initial state to the final one is carried out by such a sequence of states that minimizes the total cost of the system evolution.
Data Matrix codes can be a significant factor in increasing productivity and efficiency in production processes. An important point in deploying Data Matrix codes is their recognition and decoding. In this paper is presented a computationally efficient algorithm for locating Data Matrix codes in the images. Image areas that may contain the Data Matrix code are to be identified firstly. To identify these areas, the thresholding, connected components labelling and examining outer bounding-box of the continuous regions is used. Subsequently, to determine the boundaries of the Data Matrix code more precisely, we work with the difference of adjacent projections around the Finder Pattern. The dimensions of the Data Matrix code are determined by analyzing the local extremes around the Timing Pattern. We verified the proposed method on a testing set of synthetic and real scene images and compared it with the results of other open-source and commercial solutions. The proposed method has achieved better results than competitive commercial solutions.
The paper focuses on measuring and evaluating the impact of selected technical and technological factors -the height of adjustable guides and stretching force - on the side deflection of the saw band of a joinery band saw. There is a detailed description of the ways the side deflection can be measured. In order to find out the intensity of the stretching force was used portable tension meter SANDVIK 5000, enabling to check the tensile stress in the saw blades of a gang saw or in the saw bands of a band saw. The actual experiment was conducted on a joinery band saw, at the cutting rate vc = 15 m·s-1. The results of the measurements confirmed the theoretical assumption of the impact of the selected technical and technological factors on the stability of the saw band, where the side deflection decreases with increasing stretching force and increases with increasing height of the guides. The stability of the saw band affects the quality of the surface to be treated, thus saving the cost of machining the workpiece and making work productivity more efficient.
A new efficient CNG module design for the transportation of natural gas by sea is proposed and substantiated. A mathematical model for determining the technical and economic parameters of a movable pipeline module, which is designed for transporting natural gas in a compressed state and consists of a frame structure, the dimensions of which correspond to the 40-foot marine container size and a pipe coil is described. To facilitate construction, it is proposed that a large portion of the coil be made in the form of a two-layer composite construction. The inner layer consists of standard steel tubes or adapters, and the outer layer is fiberglass wound on them. On the basis of the mathematical model an algorithm and a program were compiled, which allowed to determine the technical and economic parameters of the movable pipeline module. The results obtained for the Caspian region are analyzed.