Papers by Keyword: Methodology

Abstract: Comparison of experimental and calculated data of the excavator utilization factor in time (K_u) according to the current methods showed the absence of even a correlation between them r = 0.17, which indicates the inexpediency of using the basic models that are the basis of these methods. The reason for the low correspondence is that the excavation processes are complex random dynamic non-stationary processes, and the models that are the basis of almost all current methods are simple deterministic static models that cannot successfully operate at the level required for such processes. In the work with the application of the theory of mass service systems, a set of probabilistic dynamic non-stationary models in the form of Markov-Kolmogorov equations was developed to describe the probability of states, both for each of the selected subsystems of downtime of excavation works, and for the “excavator face” system as a whole. Comparison of the actual values of the coefficient (K_u) obtained as a result of the experiment allows us to recommend the developed set of models as the basis of the methodology for calculating K_u (r = 0.70).

Abstract: Safety, by definition, is a state of protection against hazards, which implies measures for reduction/evasion/exclusion of risks. Safety is relative, depending on the degree of implementation of measures in specific conditions. The concept of security should only be considered as a result of risk management. Modern risk management practice is the basic risk levels and balancing between the need to ensure a certain level of security and the economic feasibility of investment in security measures. In practice, despite the declared safety priorities, industries are balanced between investment in security and an acceptable level of risk, without considering the nature and degree of influence of security measures at the stage of their development. This method of balancing is characterized by the desire of business to formally meet the general standards of risk management in order to minimize costs, minimize social and other types of responsibility, for the sake of maximizing income, which is a common problem. This problem is particularly acute in the context of national and industrial security.

Abstract: Spain and Portugal share a common track gauge, different from the European standard gauge, and they have come to have 5 rail connections of which only 3 are currently active. On the two disused connections two different programs have developed for their respective protection, conservation, and valuation in the service of society. In the Spanish province of Salamanca, the route from the railway station of Boadilla-Fuente de San Esteban to the Portuguese border. This route has been recognized as a Bien de Interés Cultural (BIC) since 2000 and has been preserved including all the infrastructure and a good part of the railway superstructure. The Camino de Hierro program, at the final section, is a route of 17 km, conditioned for walking, crossing the Natural Park of Arribes del Duero. The program is managed by public initiative of the Diputación de Salamanca. On the other hand, we have the railway connection from Caceres to Valencia de Alcantara (last Spanish town) that then crosses into Portugal through Marvão-Beirã (first Portuguese station) to Torre das Vargens, where it connects with the route currently in use from Badajoz, through Elvas to main station of Entroncamento. Between the first two Portuguese stations, a private initiative (Rail Bike Marvão) has launched a program to make this 15 km route traversable on pedal-operated platforms on the railway and crossing the Serra de São Mamede Natural Park. This paper analyses both initiatives, identifying their strengths and weaknesses and the strategies employed as examples of good reference practices for similar initiatives, in order to identify key aspects which will be part of the criteria that the authors want to define as the initial phase of a methodology for the application of decision-making techniques in the management of these kind of assets.

Abstract: Fused Deposition Modelling (FDM) is a common technique used when rapid prototyping is needed to perform a preliminary evaluation of the suitability of a part. For this purpose, several materials, as PLA, ABS, PET-G and others, are easily available in the market along with a wide range of commercial 3D printers at affordable prices. Prototypes manufactured under this technique are usually made of a single material and, for most of the applications, it is enough to fulfill the required specifications. However, the increasing demand for the manufacturing of parts made of more than one material suggests that prototyping via FDM using two dissimilar materials should be assessed to assure that such technique is still acceptable to perform a preliminary evaluation of a part. For this purpose, a methodology using a commercial FDM 3D printer is proposed to characterize the flexural and shear bonding behavior of two dissimilar materials. This methodology implements four steps: The selection of the applicable UNE standards as main reference, the design and manufacture of the test specimens based on these standards, the execution of the structural tests to characterize the behavior of those specimens and the analysis of the test data along with the conclusions. This methodology has been validated using ABS and PLA as base materials. The coherence and accuracy of the results obtained from this specific case substantiate that it is a valid methodology to evaluate the structural behavior of the bonding of two dissimilar materials, beyond PLA and ABS, using commercial and affordable off-the-shelf 3D printers.

Abstract: The article examines the aspects of predicting the durability of equipment components assembled using polymer reinforcing compounds. A method for calculating the key parameters of joints that have a primary impact on the durability of friction units is presented.

Abstract: The quality of the high-carbon rod is determined by mechanical properties, which depend on microstructure characteristics, in particular the perlite grain grade. The existing technique for determining the perlite dispersion has the main drawback - the subjectivity of choosing the five worst view fields for evaluation, which reduces the accuracy of the determination results. The article presents the results of a study aimed at increasing the objectivity and accuracy of the evaluation of high-carbon wire rod perlite grain grade. An improved technique for determining the high-carbon wire rod perlite grain grade – P_gg with five view fields is proposed. The cross-section of the rod sample is considered as an inhomogeneous area from the perlite dispersion point of view, which is divided into three annular zones with different levels of perlite dispersion. Selection of five view fields is carried out as follows: one from the center of the central zone, two fields in the second - an intermediate zone and two fields in the outer zone. Statistical analysis of the experimental data showed that all view fields should be located on the same diagonal. The location of the view fields is fixed and is unchangeable for all samples under study. The technique described in the article is an effective tool for analyzing the structure of high-carbon steel wire rod.

Abstract: At present, the solution of not only the tactical tasks of the structure technical state preserving but also the strategic tasks of the erected and existing structures quality improving in order to develop the road and transport network in the development perspective lines is topical. The construction organization of the bridge structures is a complex process; it requires the performing work careful monitoring. The approach based on the information modeling used by construction participants, including the construction control service, is proposed in this paper. The article is devoted to the methodology that allows improving the document circulation procedure organization process efficiency and coordinating changes, due to the introduction of the information modeling technology, which influences on the building construction duration. The database is created to introduce the necessary data into the information model of the bridge structure, as well as the result parameters of the interaction with the model. The data on the practical implementation of the proposed approach on the example of the bridge construction object is presented; the analysis is made compared with the established process of construction production organization, and the advantages of the first one are fixed.

Abstract: The aim of this paper was to establish a gas chromatography (GC) method for the determination of 4-amino-2-methylpentane and validate the methodology. The gas chromatography conditions such as column temperature, carrier gas flow rate, split ratio and the make-up gas flow rate were investigated in detail. The chromatographic column used in this method was capillary column of DA-1. The oven temperature was initially held at 40 °C for 15 min and was then programmed temperature to 140 °C at the rate of 75 °C/min and held for 10 min. The injection temperature was 180 °C and the flame ionization detector temperature was 200 °C. The carrier gas was high pure nitrogen with a flow rate of 0.8 mL/min. The split ratio was 130:1 and the make-up gas flow rate was 30 mL/min. Good linearity of 4-amino-2-methylpentane was obtained within the concentration range of 25.44 mg/mL to 84.81 mg/mL and the correlation coefficient was 0.9990. Good accuracy and precision were obtained and the average recovery was 101.76%. The quantification limit of 4-amino-2-methylpentane was 7.21 μg/mL and the detection limit of that was 3.72 μg/mL. The method was well-validated and proved to be used for quality test of 4-amino-2-methylpentane.

Abstract: Results of the health risk (HR) assessment are needed to support decisions on safety of nanotechnologies and practical use of nanomaterials/nanoparticles (NMs/NPs), including establishment of health safety standards (HSSs). To meet these needs HR assessment’ tools are developed using the great experience in the development and application of such tools for other sources of harm (ionizing radiation, chemicals, etc.), accumulated during the last decades. The tools include methodology, computer data bases and calculation codes.Three-level’ scheme of development and application of HR assessment methodology is roposed: general, specific and simplified methods. The general method serves as a basis for development of specific methods, applicable to the concrete harm sources, for development and justification of simplified methods. In this approach the specific method consists of two parts: 1) the general HR assessment method, 2) exposure – response dependences for the harm source considered in the form of age-cause-specific death or diseases coefficients. Such structure of HR assessment methodology in its full development makes specific methods being more transparent and comparable as well as safety decisions based on HR assessment for different harm sources.The proposal is made concerning the special risk index for the risk standardization and comparison. The unified approach is developed to the establishment of the HSSs and other levels of decision-making on people safety with the use of HR risk assessment in different spheres of human activity including nanotechnology and use of NPs/NMs.

Abstract: Startups can substantially contribute to the industrial development in the early and newly industrialized countries by transforming technological inventions into products and services. By means of the market dynamics of cooperation and competition in global value creation and knowledge networks, new products and services can conduce to a global industrial development. Hence, in pursuance of an efficient and effective startup development, this paper will present a new methodology for the integrated development of the product and of the business model for a hardware startup. Hardware startups address the development of innovative tangible products. The hardware product itself may consist of mechanical, electronical, and software components. The methodology is based on a micro cycle for the problem-solving procedure on the level of single process steps as well as on a macro cycle as procedure for the overall integrated development of the startup. For each phase of the macro cycle, specific modelling methods for the product and business model are proposed. Finally, a proof of concept on the basis of a student startup, which is developing a micro wind turbine, will be presented.