Volume 9, Issue 1

In this paper authors conduct a case study analysis by implementing the use of UAVs in the data collection within the BRAIN framework for the failures diagnosis of facades. The main goal is to assess the conditions and usefulness of UAVs in the BRAIN protocol by analyzing the goodness of fit to the fundamental requirements that support this inspection methodology. This preliminary qualitative approach allows the authors to investigate the benefits and potential of this high performance technology as a complement or alternative tool to the initial method, which is based on visual inspections supported, as maximum, by high resolution digital camera images. For the study a sample of facades has been selected in Poland. A full equipped UAV has been collecting the images. Finally, full procedure, collected data and positive and negative issues has been assessed under the perspective of the requirements involved in a multiscale BRAIN inspection. Overall scoring conditions has been determined and, as a conclusion, it can be stated that the use of UAVs for technical inspections in a population based predictive approach is, and even more it will be in the future, an interesting complementary tool for the data collection.

Practical problems in construction can be easily qualified as NP-hard (non-deterministic, polynomial-time hard) problems. The time needed for solving these problems grows exponentially with the increase of the problem’s size – this is why mathematical and heuristic methods do not enable finding solutions to complicated construction problems within an acceptable period of time. In the view of many authors, metaheuristic algorithms seem to be the most appropriate measures for scheduling and task sequencing. However even metaheuristic approach does not guarantee finding the optimal solution and algorithms tend to get stuck around local optima of objective functions. This is why authors considered improving the metaheuristic approach by the use of neural networks. In the article, authors analyse possible benefits of using a hybrid approach with the use of metaheuristics and neural networks for solving the multi-mode, resource-constrained, project-scheduling problem (MRCPSP). The suggested approach is described and tested on a model construction project schedule. The results are promising for construction practitioners, the hybrid approach improved results in 87% of tests. Based on the research outcomes, authors suggest future research ideas.

The work contains information on the implementation of surveying works in the road construction process. The aim of the research was to identify geodetic risk factors occurring at the stage of preparation of a construction project, the presence of which can greatly disrupt the undertaking such as the road construction. The research was carried out on the basis of expert knowledge, documentation obtained from various road construction projects and the analysis of disturbances at the initial stage of works.

Over time, historic buildings are exposed to various destructive mechanisms brought about by a wide range of damaging factors. Costs and methods of reinforcing their individual components are, among others, an important issue. The term "reinforcement" is linked with the concept of conservation, which stands for the actions taken with the aim of preserving a building. It provides a well-articulated system consisting of activities that lead to the reinforcement of the structure, usability enhancement or to the improvement of its carrying capacity. This article analyses the selection of an appropriate brick pillar reinforcement method, taking into account accepted evaluation criteria.

A building investment, especially in nature valuable areas, is almost always inseparable with a bigger or smaller environmental interference. For a few years there are legal regulations created to protect these areas. One of them is the requirement to conduct a habitat evaluation and to prepare a habitat report if there is a indication of significant impact on the Natura 200 site. The quality of such a report is crucial for completion an investment in a chosen localisation as well as for shortening a preparation stage with respect to environmental requirements. A defective report can result in a agreement refusal of investment completion conditions of an investment by an authorised body, and can be a reason for protests of a community which is affected by the planned investment. A well-made report, on the other hand, results in a smooth acceptance of the project without the need for consultation of the investor with the proceeding body and saving the cost of correction of a defective documentation. An review of the literature done by the authors and the talks carried out with the staff making an assessment of reports of an impact on Natura 2000 sites showed the lack of common use in practise of a formalised set of criteria of evaluation of such documents. The aim of the study was to prepare a set of evaluation criteria for reports on environmental impact on Natura 2000 sites. The set was tested on already made reports and it showed their basic omissions and disparities. The set prepared can be used by an investor in the course of making a report. It can be also a useful tool for a verifying clerk while evaluating a report for its completeness and adequacy. On the basis of the prepared set of evaluation criteria, a procedure was proposed allowing an impartial verification of reports. As a result of analyses made, a procedure was worked out which is presented in the diagram concluding this paper.

In the present context, companies to be competitive must develop high-performance innovation capabilities that enable them to respond quickly to market needs. However, the lack of tools and methodologies to assess the performance of innovation projects in an integrated way remains an obstacle. The paper begins by discussing the principles of Six Sigma and the Balanced Scorecard for performance evaluation. Next, the advantages of the Six Sigma Business Scorecard are discussed as a tool to support the evaluation of performance in innovation projects. Finally, the advantages of their application in the context of a collaborative ecosystem are discussed. It is illustrated that the BSC ensures that top management pays attention at any time to the specific elements of the Six Sigma implementation that are not working as planned, providing a link between strategy and quality initiatives assuring customers satisfaction in innovation projects.

Knowledge about the input–output relations of a system can be very important in many practical situations in engineering. Linear systems theory comes from applied mathematics as an efficient and simple modeling technique for input–output systems relations. Many identification problems arise from a set of linear equations, using known outputs only. It is a type of inverse problems, whenever systems inputs are sought by its output only. This work presents a regularization method, called random matrix method, which is able to reduce errors on the solution of ill-conditioned inverse problems by introducing modifications into the matrix operator that rules the problem. The main advantage of this approach is the possibility of reducing the condition number of the matrix using the probability density function that models the noise in the measurements, leading to better regularization performance. The method described was applied in the context of a force identification problem and the results were compared quantitatively and qualitatively with the classical Tikhonov regularization method. Results show the presented technique provides better results than Tikhonov method when dealing with high-level ill-conditioned inverse problems.

There is an increasing need to have a safety system, which allows safe collaboration of operators and industrial robots. Industrial robots are powerful and therefore dangerous impacts and crashes need to be prevented by keeping safe distance between moving robot and the operator. Safe distance can be achieved by monitoring the position and speed of the robot and the position of the operator. Separation distance, speeds and performance of the control system, sensors and actuators are regulated by standards, which must be followed. VTT has developed a dynamic safety system, which monitors the speed and separation between persons and the robot in order to keep the stopping distance of the robot small enough to avoid impacts. The dynamic safety system enables safe continuous working beside the robot and automated restarting after a safety-rated monitored stop. An assistance system is applied to switch safety modes of the robot according to separation distance. Configuring and validating the safety system are safety-critical and time-consuming phases of design. Therefore, a configuration tool is required to get a coherent configuration, which support validation process.

This paper presents technical and economic assessment of a hybrid energy system for electricity generation in rural communities in the six geopolitical zones of Nigeria. The study was based on a 500 rural household model having an electric load of 493 kWh per day. To simulate long-term continuous implementation of the hybrid system, 21 years (1992 – 2012) hourly mean global solar radiation and wind speed data for the selected sites were used. The mean annual wind speed and solar radiation for the locations ranged from 2.31 m/s for Warri to 3.52 m/ s for Maiduguri and 4.53 kWh/m 2 for Warri to 5.92 kWh/m 2 for Maiduguri, respectively. These weather data were used for simulation with the Micro-power Optimization Model software HOMER. From the optimum results of the hybrid system,Warri has the highest NPC and COE of $2,441,222 and $0.721/kWh, respectively while Maiduguri has the least NPC and COE of $2,225,387 and $0.658/kWh, respectively for the 21 years project lifespan. The high value of COE for Warri is due to its low renewable energy resource while low COE for Maiduguri is due to its high renewable energy resource. The Northern part of the country has ample renewable energy resource availability and with a strong political will, optimal utilization of these renewable resources (solar and wind) can be actualized. Researchers, Industrialists, Policy Makers and the Nigerian government should therefore seize this opportunity in developing a sustainable energy through utilization of abundant renewable energy resources in the country.

Freshwater is an essential natural resource for humanity, however, its quality has been compromised as a result of natural and anthropogenic interference. The objective of the present study was to determine the Bascarán Water Quality Index ( WQI B ) for the Tamanduá stream in the municipality of Aparecida de Goiânia, Goiás, Brazil, and relate it to the limits established by CONAMA resolutions n º 357 [1] and n º 274 [2], for Class 2 freshwater bodies. The study was carried out at three sampling points proximate to urban parks, with samples collected in both the dry and the rainy seasons with the measurement of flow. The physical, chemical and biological parameters were analyzed as recommended in Standard Methods [3]. Parametric descriptive statistics were used for data analysis. The WQI B results classified the water as acceptable (24%), normal (48%), improper (20%) and unpleasant (8%), with turbidity, DO and total coliforms responsible for decreased WQI B in the rainy season. The parameters pH, apparent color and DO do not conform with CONAMA resolution n º 357 [1] while water resources for bathing were classified as excellent according to CONAMA resolution n º 274 [2].

Education sector, and particularly, Higher Education Institutions (HEI), is nowadays an increasingly competitive sector, where the HEI’s success, relies on stakeholder’s recognition, along with their capacity to attract funding, to achieve sustainability. To attends such demands, HEI tends to incorporate into their strategy, Internal Quality Assurance Systems (IQAS). Additionally, and according to some works, existed on literature, HEI should follows a logic of continuous improvement, through the services provided to their stakeholders, where EFQM (European Foundation for Quality Management) model, arises as an alternative solution to be considered. However, and although the success achieved with this model on private sector, there are no certainties about the results of their implementation in HEI, since some of the adopted models have a set of techniques based on theories, sometimes incompatible within HEI nature. Therefore, and by using the case study methodology, it is intended to analyze the feasibility of an IQAS implementation, based on the EFQM model, in an Engineering School in Portugal. For this purpose, they are identified some advantages and difficulties found within its implementation, as well as ways to overcome them, contributing therefore with some answers for a better EFQM implementation into a HEI in general.

Any building construction undertaking is inseparable from the environment in which it will be executed. Among all buildings, the most difficult ones from the point of view of nature protection are those which have been classified as having a considerable impact on the environment. Roads and road infrastructure are a particular case. Construction of roads or railroads and their subsequent long-term use lead to many changes in the environment. When planning such building projects, it is recommended to develop variant solutions in order to choose the one that would be least harmful to the environment, and then to submit them to an objective assessment. To facilitate the selection of an optimal solution, assessment indicators are developed. However, it needs to be remembered that a factor perceived as a negative one in the immediate assessment might generate positive consequences on a broader scale and vice versa. Hence, an assessment of the impacts on the environment caused by building projects should be viewed in the context of indirect (global) and direct (local) effects. This article will present a model analysis of the impacts caused by a fragment of a road, including local and global effects measured by the indicator method. This method has been developed by the author of this article, who believes that it enables the user to make a complex analysis, while the graphic presentation it involves, discussed in the conclusions to this paper, helps to decide easily which factors are decisive in the final assessment of the analysed project.

A lot of researchers are closely connected with natural, lignocellulose fibre containing bio-composites producing and studies. Various of polymer matrices, mainly polyolefins, combinations with natural fibres as a reinforcement are used. Our studies are focused on polypropylene based bio-composites containing birch plywood production by-product sanding dust (PSD) accelerated weathering processes. The nine groups of the samples with different composition were exposed in an accelerated weathering chamber for a total duration of the 1032 h. The surface colour, gloss, whiteness degree, micro-hardness and the tensile properties of the samples during the weathering were tested. In addition, the weathered surfaces were characterized by scanning electron microscopy (SEM) studies and by differential scanning calorimetry (DSC) investigations. The obtained results showed the following sight: after the weathering the surface of all samples is faded, also the changes of the gloss and of the whiteness degree occurs, but microhardness of the surface of specimens has decreased. The tensile strength of the samples changes a little, in the same time the tensile modulus increases significantly due to the decrease of the deformation ability of the polypropylene matrix and recrystallization processes in PP. The SEM images taken at the 100 and 500 times of the magnification revealed a lot of the different shape and sizes cracks on the surface of the weathered samples. DSC measurements showed the increase of the degree of crystallinity of the polypropylene after the weathering due to the recrystallization process in the polypropylene matrix.

In the article the costs of alternative roofing techniques in the life cycle of the building were calculated. The calculations were made in accordance with ISO 15686-5 standard “Buildings and constructed assets – Service life planning – Part 5: Life-cycle costing”, using normative durability periods and minimum period of annual consumption of individual building elements to determine the durability of building components. The normative periods are valid in Poland in relation to the valuation of buildings. Probabilistic costs in the life cycle of ceramic, metal and bituminous coatings were analysed. The probability density distributions were assumed: beta for pricing factors and normal for the interest rate. Calculations were carried out for the periods of 100 years of operation of coverings, taking into account the costs of replacement and utilization. As a result of the calculations, the life cycle costs of alternative coatings with probabilities from 5 to 95% were obtained.

This research is to compare the performance of Loan Approval System Web Services using SOAP Web Service and REST Web Service. There are 3 parameters that will be used in this study based on Quality of Services parameter, throughput, response time and latency. There are 4 different services will be tested to get the result of quality of services, Installment Services, Customer Services, Blacklist Customer Services and Account Services. The result of analysis showed that there was significant difference in the Quality of Services between Loan Approval System Web Services using SOAP Web Service and REST Web Service. The results can be concluded that REST Web service is more appropriate to be used in the integration between Loan Approval System and Core system.

Rehabilitation and Sustainability complement each other insofar as new uses are defined for the existing constructions, avoiding the disposal and consequent environmental impact of this action. In Brazil, the culture of new construction still prevails, even with the relevant inventory of existing buildings, as indicated in studies conducted in Rio de Janeiro and São Paulo. Dissemination of knowledge of rehabilitation techniques can encourage the development of strategies for the implementation of these practices in brazilian market. Therefore, this paper will try to indicate techniques that may be improved and incorporated into the rehabilitation of Brazilian constructions, aiming aspects of sustainability and reinsertion of contemporary construction in urban heritage.

In this paper, novel synthesis conditions for state-feedback Linear Parameter Varying (LPV) controller with Input Covariance Constraints (ICC) are developed. The synthesis conditions achieve the following design requirements 1) some constraints need to be satisfied on the control energy and 2) optimizing the performance outputs for the entire parameter space of the LPV system. These conditions are formulated as convex optimization problem with Parameterized Linear Matrix Inequalities (PLMIs) constraints. The effectiveness of the proposed approach is illustrated through numerical examples.

Efficient spending of public money is a crucial requirement of public procurement. This requirement is even more important in the case of public works contracts since construction projects are usually very costly. Accordingly, public authorities should manage the procurement process in an efficient way. The aim of this paper is to analyse municipal procurement practices focusing on small-scale public contracts for construction works. The Czech Republic is the study area for this analysis. Data concerning procurement practices were collected through a questionnaire survey and on the basis of available internal municipal directives that govern the procurement process. The results show that a majority of municipalities use internal directives and specify financial categories for small-scale public contracts. It has also been found that the majority of municipalities contract external consulting companies for specific contracts or subsidised public contracts. Directives usually concern the issue of responsibility and the approval procedure related to the public contract. Based on the research findings, general recommendations for awarding public contracts have been formulated. These findings can potentially contribute to the dissemination of best practices among contracting authorities in the Czech Republic.

The approach used by construction companies to determine bid prices is an element of their strategy used to win jobs in competitive tenders. Such strategies build upon an analysis of the contactor’s potential and capabilities (am I able to deliver? am I eligible to participate in the tender?), and the analysis of the economic environment, including the expected behavior of competitors. The tender strategy sets out both the guidelines and the procedure in deciding whether or not to bid as well as the rules for determining the price. The price, on the one hand, should be high enough to cover expected direct and indirect costs as well as risk-adjusted profit. On the other hand, it needs to be low enough to be considered most attractive (typically: the lowest) among the prices offered by the competitors. The paper focuses on the price definition component of the bidding strategy. It provides a brief overview of the existing methods that support bidding decisions by comparing their demand for input and limitations in practical applications and presents a simulation-based method supporting the determination of the profit ratio. This probabilistic method assumes the existence of a positive correlation between the prices offered by the competitors. Its application is illustrated by means of a numerical example. The outcomes of the simulation prompt the amount of the profit margin that maximizes the expected value of the contractor’s profit.

Planning, controlling, monitoring progress are key management functions for effective implementation of construction projects. Commonly used instruments enabling performance of these functions include schedules and budgets, often in the form of a cost estimate. They are created at the initial planning stage to monitor and control cost and time deviations. Moreover, popular monitoring techniques are, for example, observation of milestones and comparative analysis of actual versus planned costs. This article presents a work progress control tool - the Earned Value Method (EVM) - which, despite its benefits, remains relatively unused in construction projects. The impact of the planning phase on the results obtained during the monitoring and control phase when utilizing EVM is discussed. This case study provides practical examples of using EVM in the implementation of construction projects and with the use of computer software. The novelty of the article results from the introduction of additional sensitivity analysis illustrating the impact of factors, such as an increase in costs or a change in delivery dates to the course of deviation curves. Use of sensitivity analysis in relation to the results of the CPI and SPI calculations affords combining control of costs and time with risk monitoring in the project. The findings reveal significant benefits in using EVM to implement construction projects but also highlight some important limitations.

The aim of the research is to develop a model to support renovation and modernization decisions in the process of maintaining public buildings. The scope of the research includes, first of all, the development of a method of building assessment on the basis of many criteria, applied also in the evaluation of residential buildings, but also specific ones, related to public utility facilities, i.e .: environmental compatibility of buildings, adaptation to the elderly and disabled, fire safety. On the basis of this assessment, a set of proposed renovation and modernisation measures will be determined. In the next stage, knowledge will be acquired from experts (including property managers), who will indicate the ranges of criteria values for the adopted assessments of building utility value. This knowledge will be used to build a rules base of fuzzy inference system for assessing building utility value. The next stage of research will be conducting computer simulations with the use of a mathematical model assessing the impact of the above mentioned decisions on the increase in the building utility value and the renovation cost and modernization activities. All calculations will be carried out in the Matlab Simulink environment with the use of optimization and fuzzy methods. Knowledge of the relationship between decisions on the scope of renovation and modernization solutions and the quality measures of the maintenance process is the basis for decisions in the area of buildings maintenance. The results of these studies can contribute to improving the quality of maintenance of public buildings.

The main goal of the presented research was to verify the possibility of obtaining ecological self-compacting concrete of low hardening temperature, containing different types of cements with calcareous fly ash W as main component and the influence of these cements on basic properties of fresh and hardened concrete. Cements CEM II containing calcareous fly ash W make it possible to obtain self-compacting concrete (SCC) with similar initial flowability to analogous mixtures with reference cement CEM I and CEM III/B, and slightly higher, but still acceptable, flowability loss. Properties of hardened concretes with these cements are similar in comparison to CEM I and CEM III concretes. By using cement nonstandard, new generation multi-component cement CEM “X”/A (S-W), self-compacting concrete was obtained with good workability and properties in hardened state.

The failure of tools will make a large impact to the productivity, so it must be investigated to avoid the next failure. In this case, the super hard end mill HSS-Co list 4SE code 6210 was broken when it was used for side milling processing of mild steel AISI A36 with rotation speed, cutting speed and cutting depth of 540 rpm, 0.10 m/min (4 ipm) and 16 mm respectively. Standard procedure of failure analysis was performed including macro-micro investigation using Scanning Electron Microscopy (SEM) with energy-dispersive spectrometry (EDS) attachment, micro hardness test, and Finite Element Methods (FEM) simulation. The results of failure analysis showed that fracture occurred due to stress concentration and micro defects of the super hard end mill. Two parts of fracture surface, rough and fine surface were found. Based on SEM-EDS investigation, it was known that the content of tungsten (W) and cobalt (Co) elements on the rough and fine surface was inhomogeneous. Excessive Co and W elements appeared on the fine surface while they disappeared on the rough surface. Excessive Co will diffuse with tungsten and carbon and lead to the separation of tungsten and carbon elements, so it greatly destroyed the alloys and lead to form the non-stoichiometry carbide points. Hence, the defective manufacturing processes which made the elements distribute inhomogeneous is concluded as the reason of the super hard end mill failure.

Repetition of the same processes on different objects or units of a construction project and their concurrent execution makes it necessary to use the same limited resources at the same time. Managers prefer simple heuristic priority rules to scheduling construction activities, but there is not one the best for all projects. In addition that the experience from deterministic scheduling problems and priority-rule methods cannot always be directly transferred to stochastic environment. The paper presents the pure reactive simulation model for planning construction projects in random conditions, taking into account the availability of renewable resources. Conducting simulation tests allows for various priority rules to determine the distribution of construction project duration and evaluate the robustness of the schedule. The paper analyzes the effectiveness of the selected priority rules in a pipe line project. In the analyzed project, the Dynamic Minimum Slack rule ensures the lowest average duration of the project in random conditions and the highest quality robustness. The analysis of the simulation results can help the construction manager to choose the procedure ensuring the timely completion of the construction project in the stochastic environment.

The energy consumption in buildings, can be reduced through a rational choice of the household appliances to be acquired. This choice can be based, on a specific criteria, settled according to the consumer needs. However, such choice, still needs to be optimized, since in general, an efficient equipment has a high investment, although a low energy consumption. Genetic Algorithms (GAs) are used therefore, as an optimization technique, to get efficient and several solutions, based on those pre-selected from the market, and according to a set of criteria. However, there is a need to assess its robustness as well as its consistence in terms of convergence results. The quality of its solutions is also assessed, by comparing GAs results with those, obtained from Simplex method. The problem formulation, and its influence on GAs results, is also considered on this work, where it’s chosen the best one, among four proposed. In this paper it is presented a methodology that allows to promote energy efficiency in buildings, by achieving savings in terms of initial investment, energy consumption and CO 2 emissions for the consumer. It is shown that GAs, can provide several and optimal solutions, through formulation and parameters suitable.

The article presents the most frequently chosen heating systems for single-family houses and utility water heating by investors. The most popular installations based on conventional fuels using renewable energy sources were compared. A technical and cost analysis of the adopted cases was carried out. Finally, the most important conclusions resulting from the analys is were given. The article is mainly intended to encourage the reader - the investor to be to choose pro-ecological solutions based on modern technology that guarantees comfortable use and limited environmental pollution. The authors wanted to achieve the intended goal by presenting available heating systems and performing an in-depth analysis, after which the obtained results would be similar to the real situation.

One of the key problems in managing the realization of a construction project is the selection of appropriate working crews and coordinating their activities in a way that ensures the highest degree of implementation of defined goals (minimizing the project duration and/or reducing downtime and related costs). Most of the existing methods of work harmonization used in construction industry allow obtaining the desired results only in relation to the organization of the processes realization in repetitive linear projects. In case of realization of non-linear construction objects or construction units, it is usually necessary to choose between the reduction of the project implementation time and maintaining the continuity of crews work on the units. It was found that there is a lack in the literature of developed method enabling harmonization of crews’ work, while minimizing the downtime at work and the duration of the entire project taking into account additional constraints, e.g. the need to not exceed the deadlines for the realization of the project stages. The article presents the concept of a multi-criteria optimization method of harmonizing the execution of non-linear processes of a multi-unit construction project in deterministic conditions. It will enable the reduction of realization time and downtimes in work, taking into account the preferences of the decision maker regarding the relevance of the optimization criteria. A mathematical model for optimizing the selection of crews and order of completion of units in multi-unit construction projects was also developed. In order to present the possibility of usage of the developed concept, an example of the optimal selection of crews and their work schedule was solved and presented. The proposed method may allow for better use of the existing production potential of construction enterprises and ensure synchronization of the crews employed during the work, especially in the case of difficulties in acquiring qualified staff in construction industry.

Silicate products are products made exclusively from natural raw materials. A relatively high value of the heat transfer coefficient is still considered a fault. This property adversely affects the thermal insulation of buildings and energy consumption, so you should look for materials with a low heat conduction coefficient. One of the ways of obtaining such products can be the use of light, porous fillers in the mass of lime-sand products. Due to the above, particular attention was paid to white foam glass in the form of granules, which is a product of recycling glass cullet. The research was carried out with a granulate size of 0.25-0.5 mm, share of which in the tested samples ranged from 5 to 30%. The obtained results were referred to the tests carried out on basic (lime-sand) sample. The aim of the article is to determine the correctness of the formation of selected usable properties of modified lime-sand products, taking into account changes in their microstructure. The article describes the results of volume density and compressive strength tests of basic samples and the samples modified by using the expanded glass granulate as well as the results of their observations by using of SEM and tests of phase composition obtained from XRD.

The loose material, falling freely on the flat area, creates a geometric object similar to the roof. This object, which is in fact an embankment, the authors described and examined in previous works. They stated that the top view of such an object is a flat diagram of Voronoi. In view of the need to enlarge the landfill by combining the existing disjoint embankments, the authors were encouraged to apply the results obtained in practice. They also provided a detailed methodology for creating such embankments. In particular, they used the standard version of AutoCAD software and built a 3D model of the landfill based on solid operations. This parametric approach to design enables the rapid determination of the volume and surface area and fits in the BIM technology of designing engineering objects.

The construction industry is characterized by a large variety and variability of implementation conditions. Construction works are carried out throughout the whole calendar year under varying atmospheric conditions, both during the day and also during the evening and night. Construction workers also often work overtime that exceeds the eight-hour working day. Work in such conditions creates a particularly high threat to the health and life of working people. In the issues of work safety the most important is worker, who in the accident process has a triple role: the decision maker, the perpetrator of an accident and the victim. The purpose of this article is to examine whether there is a dependence between the number of occupational accidents in the construction industry and time parameters such as: the time of an accident, the day of the week and the month in which an accident occurred. The article also attempts to determine the dependence between the age of the injured person, work experience and the number of hours worked by the injured person from the time of starting work to the moment of the accident.

The article presents detailed analysis of the case of the renovation of one of historic tenement houses in Warsaw. Other, similar cases analyzed in less detail- were called verification cases. The aim of the article was, first of all, to present the scale of discrepancies between planned and performed amount of works and possibly precise indication of the reasons for these underestimations. The scope of the research included the inventory of the technical condition of selected building elements, the execution of bill of quantities, quantity survey and cost estimates of selected works. The conducted research shows that quantity survey of works subjected to analysis such as: repair of walls, chimneys and brick walls reached the value at least twice as large. The planned cost of works calculated on the basis of the event was exceeded approximately twice. This was mainly due to the fact that the impact of repair works on deterioration of the technical condition of existing building elements was not foreseen. The poor technical condition of elements that were covered was not foreseen either. On the basis of the case studied, universal observations about renovated facilities can be provided. First of all, it should be stated that a person who makes bill of quantities on such facilities should have executive experience on similar projects. Thus, a good practice would be a cooperation with a person experienced in the implementation of similar investments.

The paper presents an quantitative assessment of the wear process of the sealing ring made of pure PTFE cooperating with steel ball of the industrial valve. The three variants of the sealing PTFE ring differing in shape were taken into consideration. In the first stage the numerical simulation by means of Finite Element Method was used to determine the contact pressure between the steel ball and PTFE seal ring. In the second stage the experimental test was carried out to check the wear rate of the PTFE ring. The DN50 PN10 industrial ball valve was subjected to 1000 of the closing/opening cycles. In the three variants of the sealing ring the friction torque necessarily to open and close of valve was measured. The weight loss due to wear was determined which was the assessment of the wear degree in macro-scale. As a wear in a micro-scale the roughness parameter on the contact surface of the PTFE ring was taken as an index.

The aim of this paper is to introduce the reader to the construction of an analytical model assessing the effect of increased traffic intensities on extraordinary road traffic events on the amount of expenditures that the road administrators are forced to spend on the extra maintenance and reshaping these alternative diversion routes into the initial technical conditions. The computational mechanism of this model is based on the one hand on parameters of diversion routes temporarily transferring increased traffic intensities ( e.g . motorway traffic at closure), on the other hand on approved cost databases for the assessment of road constructions and other regulations concerning the design of road maintenance and repair. In the final part of the paper the applicability of this model in practice is assessed and some negatives that are not included in the final calculation when determining the total costs of the road administrator are mentioned.

The challenge related to waste management has become a serious worldwide environmental problem. Highly sustainable solutions, which do not involve reworking the material and are based on waste utilization, are sought. Such waste as used casting compounds, which so far has been used, among others, in construction, road construction, mining and cement production. Descriptions of the use of various waste moulding compounds, such as waste quartz compounds with water glass, quartz chamotte and quartz bentonite can be found in the literature. Due to the high content of quartz and low toxicity of bentonite sandmix, an attempt was done to use them for the production of sand-lime products. The aim of this article is to determine the suitability of the waste material as a substitute for quartz sand in the production of sand-lime products. The usability of waste was determined by laboratory tests of physicochemical characteristics of the finished silicates. Sand, which is a carrier of silica, was replaced with used moulding compounds with fractions up to 0.5 mm, in the weight amounts of 5.5, 11 and 16.5%. Applying up to 11% of used casting materials as a substitute for quartz sand with a lime content of 5.5% in the raw material mixture has a clearly positive effect on compressive strength. However, the higher share of sand substitution in the mixture weakens the mechanical features of the obtained materials. The absorptivity of the finished products increases with the increase of the inserted additions’ amounts. The influence of significant amounts of casting compound additives on the microstructure of calcium-silicate products was studied as well. It was stated, that they affect the location of the tobermorite in the volume of the autoclaved material.

The paper includes the research outputs in the area of examining the total costs of delivering products to the customer for a particular transport mode choice. The methodology of choice procedure is presented based on the calculation of threshold distance for different variants of shipments in road and rail transport based on delivery costs. The paper also assesses the possibility of compiling a multi-criteria function for enterprise logistics, that beside the costs takes into account also other aspects as rail transport availability, time for loading and unloading, shipping time or environmental impacts.

The aim of the paper is to identify the most common workplace accidents regarding injured body parts with respect to anthropometric data measurements of the population in the Slovak republic. Data from workplace accidents database over the years 2000-2017 were drawn from the records of the Slovak Forest state enterprise. The highest number of workplace accidents (31.7% of all recorded workplace accidents) occurred during the forest harvesting phase. Timber skidding with 15.9% of recorded accidents was the second highest risky phase. In four phases Timber harvesting, timber skidding,Works at conversion depot, Repairs and maintenance was 76% from all injuries in forestry state enterprises was occurred. Nonsignificant increase in the injury rate over the years 2000-2017 was determined in the analysis of the injury rate in the Slovak state forests. From the point of view of the longterm changing anthropometric parameters of the adult population, it is also necessary to take into account the ergonomic parameters and the technological procedures of the performed work and the working environment.

The purpose of this paper is to present the results of a research into the customer preferences of potential buyers of simple wood-based house for the purpose of using the Target Costing methodology. Respondents’ opinions of 280 customers were obtained through direct interviews taking place at a specialized exhibition of furniture and timber constructions in Slovakia. The object of the research was a simple wood-based house, namely a weekend garden cottage, made of northern spruce at the level of target price 9,320 €. The paper contribution is represented by the use of the Target Costing methodology in the conditions of wood-processing industry while defining the customer preference for a specific product with the subsequent use for a functional cost analysis and determining the target cost index of the evaluated components. Presented results can be used as information database for decision making in the field of make or buy decisions at the level of fixed purchase prices of individual components or as the upper price limit for producing the components by the business itself.

The effect of logistics has increased steadily in recent years. In regard to the concept of logistics, it is not only referred to as transportation of goods from place A to place B, as many people believe. Logistics covers a wide range of enterprise (supply chain) processes. It is a whole value-creation chain including not only material flows, but also energy, human resources and valuable information. The objective of this research study is to find issues and risks in the current state of supply, inventory management and warehousing process in the given enterprise. In the study, proposals to streamline the current state in terms of inventory management identification system in particular manufacturing enterprise, which is the primary purpose of the submitted paper, are outlined. The specific result is to develop the proposal to increase efficiency and reduce risk regarding the current situation of inventory management identification system applying suitable techniques of the multi-criteria analysis, in particular by the TOPSIS method and by the WSA method.

In this paper the issue of approximation of the hyperboloid offset surface off( S ( t , v ); d ) at distance d by the hyperboloid surface S 1 ( ϕ , v ) is considered. The problem of determining various surfaces approximating the hyperboloid offset surface off ( S ( t , v ); d ) is important due to the applications of the hyperboloid as a mathematical model for miscellaneous objects in the architecture and construction industry. The paper presents the method of determining the angles and coordinates of points of various surfaces approximating the hyperboloid of revolution. A two-sheet hyperboloid offset surface can be used for modelling double-layer domes. A one-sheet hyperboloid offset surface was used to model the reinforced structure of the cooling tower.

The issue of preparing a construction project, especially in the area covered by revitalisation, requires a comprehensive approach and, above all, a multifaceted analysis of the conditions during the programming and planning of the investment. Currently, the majority of investments carried out in the areas covered by the Revitalisation Programme are carried out by public entities, which results from a number of possible risks of failure of the project. The article presents possible scenarios of administrative proceedings related to planning the implementation of an investment located in the areas covered by the Revitalization Program based on the requirements of legal regulations. A list and the amount of co-financing for the investments carried out so far located in revitalised areas were also presented. Finally, an exemplary SWOT matrix for a private sector investor was proposed, which may support him in the decision to undertake a project in the area covered by the Revitalisation Programme.

Various types of trenchless methods are extensively used to create engineering barriers for the purpose of achieving relatively low hydraulic conductivity of the subsoil and hydrotechnical structures. The most commonly used technologies of the grouting curtain creating are the DSM (Deep Soil Mixing), WIPS (Vibro Injcted Thin Wall), low-pressure injection and jet-grouting. Vertical barriers are widely used in environmental control systems to restrict the lateral spreading of liquid or gaseous contaminants and for seepage control through and beneath a levees. The barrier walls are constructed in a single or two phases using a slurry composed mainly of bentonite, cementitious materials and water. Often to solve complex geotechnical problems the technologies are combined (e.g. combining DSM and jet grouting). In the paper some examples of practical application of chosen types of technology dedicated different problems solving are presented. The results of geotechnical investigations of hydraulic permeability, shear strength and depth control of cut-off wall are given. The tests were carried out using BAT system, Cone Penetration Tests (CPT) and drillings. The presented test results should help define the technical and financial criteria that should be used to compare grouting based methods and other techniques applicable to the same geotechnical special works. These recommendations should permit an adequate application of grouting techniques and contribute to finding solutions for the delicate problem of ground sealing, notably when proceeding with hydrotechnical or environmental structures placed below water table.

The technology of high temperature drying has a great influence on dimensional and selected physical changes in tension wood. Article is focused on the measurement properties such as moisture content, color changes and longitudinal warping. The quality of beech wood is determined based on structure and properties of wood, frequency of defects in wood material. The tension wood is considered as an important wood defect causing negative alterations in solid wood quality and limits industrial application of wood. The different values of longitudinal warping which were measured after drying were higher in tension wood than in normal wood. Impact of radial and tangential angle of growth rings is non-significant factor.

Compressive strength is the foremost property of concrete which is influenced by a number of parameters. These parameters plays important role for the characteristics achieved by concrete. Orthogonal decomposition, neural analysis and regression analysis tools can be utilized where the dependence and independence of these parameters to be considered. In this paper these analyses are considered for remix concrete, in which apart from the cement contents, w/c ratio, proportions of C.A., F.A., the other parameters like blend ratio (r=Q o /Q f , Q o =quantity of old partially set concrete, Q f =quantity of fresh concrete) time lag ( time between preparation and placing of concrete) also plays the important role.

This paper constitutes a partial output of carried out research and is focused on modelling the production process of car seat manufacturing. Given that manufacturing companies are currently struggling with a shortage of qualified workforce, it is the job of every business to keep their current employees. Companies make efforts to operate the most efficient production processes at very low cost and with labour saving. In order to produce at low cost, the work environment must be designed efficiently. There are many ways to do this. In this paper focused on optimizing production processes, Computerized Relative Allocation of Facilities Technique (CRAFT) and a Sankey diagram will be used.

By combining additive manufacturing with 3D measurement techniques, tailored production work-flows that include the digitizing of existing components, computer-aided design, and tool-free manufacturing of the customized parts can be envisioned, potentially reducing the costs of mass customization. The introduction of affordable depth cameras has greatly increased the consumer availability of 3D measuring. We present the application of an affordable depth camera for the 3D digitizing of existing components, the utilization of the produced data in the design process, and finally, the production of the designed component with additive manufacturing. The capabilities of the affordable depth camera system are evaluated by comparing it with photogrammetric 3D reconstruction, revealing issues in smaller geometric details and sharp edges.

The current paper aims the application of the Portuguese infrastructure asset management (IAM) methodology to a case study. The inevitable degradation of urban water infrastructures creates new challenges for water utilities engineers and manager, as they need to decide which components should be rehabilitated to efficiently match the public’s demand, while still providing a qualitative and efficient service that doesn’t compromise the financial integrity of water utilities. This methodology is based on a five-step structured sequence - (i) definition of objectives assessment criteria and metrics; (ii) diagnosis; (iii) plan production; (iv) plan implementation; and (v) monitoring and revision – being structured in three distinct levels of planning and decision ( i.e ., strategic, tactical and operational). The IAM methodology was applied to a sixty-year-old water supply system (WSS) located in Lisbon’s metropolitan area, Portugal, mainly focused on steps (i) to (iii) and to the tactical level of planning. Results obtained are discussed and the main conclusions are presented.

In this study, the effect of lime content (L %) on the plastic properties such as water-cement ratio (w/c), setting times, flowability, compressive, flexural and bond strengths of cement mortar were investigated. Based on the information in the literature the amount of lime varied between 0 to 45% (by weight of cement). The experimental results were compared with the data collected from different research studies and quantified using two different models. The plastic and hardened properties of the cement mortar modified with different percentage of lime were conducted according to the ASTM and BS standards. Based on the literature data the water to cement ratio (w/c) ranged between 0.3-0.74 percent, the w/c of 0.5 was selected in this study. The compressive and flexural strengths of cement mortar modified with lime up to 28 days of curing were ranged between 3 MPa to 65 MPa and 2 MPa to 12 MPa respectively. The compressive, flexural and bond strengths of the cement mortar decreased with increasing lime content. Vipulanandan correlation model was used to correlate the relationship between lime with consistency, setting times, flowability and compressive strength of cement mortar. Compressive and flexural strengths of cement mortar modified with lime were quantified very well as a function of w/c, lime content and curing time using nonlinear relationship.

Polyurethane (PU) foam is a lightweight material that can be used efficiently as a ground improvement method in solving excessive and differential settlement of soil foundation mainly for infrastructures such as road, highway and parking spaces. The ground improvement method is done by excavation and removal of soft soil at shallow depth and replacement with lightweight PU foam slab. This study is done to simulate the model of marine clay soil integrated with polyurethane foam using finite element method (FEM) PLAXIS 2D for prediction of settlement behavior and uplift effect due to polyurethane foam mitigation method. Model of soft clay foundation stabilized with PU foam slab with variation in thickness and overburden loads were analyzed. Results from FEM exhibited the same trend as the results of the analytical method whereby PU foam has successfully reduced the amount of settlement significantly. With the increase in PU foam thickness, the settlement is reduced, nonetheless the uplift pressure starts to increase beyond the line of effective thickness. PU foam design chart has been produced for practical application in order to adopt the effective thickness of PU foam within tolerable settlement value and uplift pressure with respect to different overburden loads for ground improvement works.

Renewable energy reliability has been the main agenda nowadays, where the internet of things (IoT) is a crucial research direction with a lot of opportunities for improvement and challenging work. Data obtained from IoT is converted into actionable information to improve wind turbine performance, driving wind energy cost down and reducing risk. However, the implementation in IoT is a challenging task because the wind turbine system level and component level need real-time control. So, this paper is dedicated to investigating wind resource assessment and lifetime estimation of wind power modules using IoT. To illustrate this issue, a model is built with sub-models of an aerodynamic rotor connected directly to a multi-pole variable speed permanent magnet synchronous generator (PMSG) with variable speed control, pitch angle control and full-scale converter connected to the grid. Besides, a large number of various sensors for measurement of wind parameters are integrated with IoT. Simulations are constructed with Matlab/Simulink and IoT ’Thingspeak’ Mathworks web service. IoT has proved to increase the reliability of measurement strategies, monitoring accuracy, and quality assurance.

Graph datasets are common in many application domains and for which their graphs are usually massive. One solution to process such massive graphs is summarization. There are two kinds of graphs, stationary and stream. For stationary graphs, a number of summarization algorithms are available while for graph stream there is no a comprehensive summarization method that summarizes a graph stream based on the structure, vertex attributes or both with varying contributions. This is because of challenges of graph stream, which are volume of data and changing of data over time. In this paper, we propose a method based on sliding-window model for which summarizes a graph stream based on a combination of the structure and vertex attributes. We proposed a new structure for summary graphs and also proposed new methods for comparing two summary graphs. To the best of our knowledge, this is the first method that summarizes a graph stream based on both the structure and vertex attributes with varying contributions. Through extensive experiments on real dataset of Amazon co-purchasing products, we have demonstrated the performance of the proposed method.

The Petaflops supercomputer “Zhores” recently launched in the “Center for Computational and Data-Intensive Science and Engineering” (CDISE) of Skolkovo Institute of Science and Technology (Skoltech) opens up new exciting opportunities for scientific discoveries in the institute especially in the areas of data-driven modeling, machine learning and artificial intelligence. This supercomputer utilizes the latest generation of Intel and NVidia processors to provide resources for the most compute intensive tasks of the Skoltech scientists working in digital pharma, predictive analytics, photonics, material science, image processing, plasma physics and many more. Currently it places 7 th in the Russian and CIS TOP-50 (2019) supercomputer list. In this article we summarize the cluster properties and discuss the measured performance and usage modes of this new scientific instrument in Skoltech.

This article describes how to reach an item’s threshold, or in other words, the limit time for it to be retrieved from stock and sold for a different use, as well as the remaining foreseen period for this situation to occur. Once a minimum length, or weight, is reached, left quantities are more difficult to sell, as demand often exceeds the remaining parts or leftovers. The number of unfulfilled orders increases, as time goes by, until it becomes further cost effective to dispose the leftover and sell it for a lower price and alternative use. A Monte Carlo simulation model was built in order to consider the randomness of future transactions and quantifying consequences providing this way a simple and effective decision-making framework.

An advanced computer technology of the thermal stress state and fatigue life analysis of turbine engine exhaust support frames based on the use of licensed engineering analysis software, as well as some specialized home codes are presented in the paper. The developed technology allows perform simulations for the full model of the structure, not only for the typical fragments models, and increase an accuracy of calculations and significantly reduce a design time.

The use of low (LCFA) and high (HCFA) calcium fly ashes in the cement industry allows the implementation of European Union proposals on waste management and energy saving. However, the possibility of using HCFA is limited, because the properties of such waste from coal-fired power plants must comply with national regulations. The paper shows the effect of partial replacement of Portland cement (OPC) by these fly ashes on the resistance of the sulphate attack of the mortars immersed in a 5% solution of sodium sulphate. In order to determine the optimal amount of ash additive, a research plan was designed using statistical methods using the Gibbs triangle for mixtures. Samples of control mortars of OPC, binary mixtures of HCFA or LCFA and ternary mixtures of HCFA/LCFA were made. The composition of the blends was designed in accordance with the statistical plan of the experiment for mixtures. The testing program included linear strains, compressive strength and microstructure tests using SEM with EDXA and XRD analysis. The results of laboratory tests and statistical analyzes have shown that fly ash has a positive effect on the sulphate resistance of cementitious composites.

The implementation of an information system that supports company goals is the main strategy of an organization. But aligning business strategies with information system(IS) and information technology(IT) is not as easy as it seems, because there are several gaps of strategies between upper level and practical level. Often the focus in system development is only on the architecture of the future system, even though the study says that the engineering model of needs is the most important thing in the process of developing the company’s system. PT. SBS is a distributor and supplier company. Along with the development of its business, business processes also become more complex. The information system that was originally felt to be sufficient is considered to be no longer optimal so that it often results in delays in delivery with a fairly large percentage. Therefore, an Enterprise Resources Planning(ERP) system will be developed but it must be ensured that the business processes used are oriented towards organizational goals. The purpose of this study is to introduce and explain the stages of the Organization Goal-Oriented Requirement Engineering (OGORE) method as a requirement engineering method in a company’s business processes that focuses on organizational goals. The research method was done by collecting business process data and defining key performance indicators(KPIs) in a small discussion group with stakeholders in the company. The results of this method were Goal Tree Model (GTM) diagrams which was then used as a reference in describing new business processes and in preparing the requirements specification documents. The conclusion obtained that the stages of the OGORE method are able to eliminate needs according to the organization’s goals. It is also recommended to use the OGORE method as one of the requirements management steps in the Enterprise Architecture method to create new method as an agenda for the future.

The deterioration of concrete in places exposed to sulphate salts, chlorides and groundwater movement is a major problem. In this research, polymer concrete was produced by testing four mixtures using different sizes of aggregates with epoxy adhesive and two mixtures were reinforced with polypropylene fibers (0.5 and 1)% by weight of Epoxy in addition to the reference mix consisting of cement and sand. Compressive strength, electrical resistivity, ultrasonic pulse velocity, flexural and porosity testing were performed at ages 7, 14, 28, and 60 days. The highest compressive strength, electrical resistance, ultrasonic pulse velocity and zero porosity for mixture had a maximum size of sand less than 600 microns and more than 150 microns, where the rate of increase (272.9, 635.9, 45.9 and 57.7)% respectively compared to the reference mixture. The results showed also that the highest flexural strength was for the mix reinforced with 1% polypropylene fiber. In addition, the specimens at age 28 day submerged in the diluted solution of sulfuric acid at 5 and 10% for 11 weeks. The results showed that there were no change in the volume and weights of the specimens that were submerged.

Ever growing building energy consumption requires advanced automation and monitoring solutions in order to improve building energy efficiency. Furthermore, aggregation of building automation data, similarly to industrial scenarios allows for condition monitoring and fault diagnostics of the Heating, Ventilations and Air Conditioning (HVAC) system. For existing buildings, the commissioned SCADA solutions provide historical trends, alarms management and setpoint curve adjustments, which are essential features for facility management personnel. The development in Internet of Things (IoT) and Industry 4.0, as well as software microservices enables higher system integration, data analytics and rich visualization to be integrated into the existing infrastructure. This paper presents the implementation of a technology stack, which can be used as a framework for improving existing and new building automation systems by increasing interconnection and integrating data analytics solutions. The implementation solution is realized and evaluated for a nearly zero energy building, as a case study.

Expanding the use of smart braced frames to govern the seismic response of structures by providing ductility and elasticity has been hampered and delayed by cost indexes. The braces in frames comprise two segments of expensive shape memory alloys (SMAs) and high-strength steel with high stiffness. These smart materials can reduce seismic damage by providing stiffness, yielding, and phase shifting. In this study, the length of the SMA segments in three- and six-story frames (applied either at all floors or as part of a dual system) was increased to determine the optimal length at a constant period. Performance levels and fragility curves were obtained to evaluate the seismic behavior of the optimized frame. The response modification factor determined based on the static pushover, incremental nonlinear dynamic analysis, and linear dynamic analysis suggests the ductility and over-strength of the optimized frame. The probability of being in or exceeding each damage state was determined with a Monte Carlo analysis and was acceptable and in accordance with previous deterministic analysis results.

In this paper, feasibility studies are presented on microneedle fabrication by using a multiple-pulse laser microhole drilling technique to drill an axial hole into a thin nitinol wire of 150 μm in diameter. Nitinol is chosen for its biocompatibility and excellent super-elasticity to eliminate breakage risk. One potential use of this microneedle is for drawing a small amount of blood for glucose monitoring. The critical factor for drilling microholes into a thin nitinol wire axially is the restoration of the semi-infinite material condition, which is the key to prevent the thin wire from being melt away by the laser due to excessive heat transfer in the radial direction. The results show that holes, up to 607 μmin depth, can be drilled into a thin nitinol wire of 150 μm in diameter using 18 repetitions of a 3-pulse group with 13 μs pluses. However, hole quality is poor. The challenges for improving hole qualities, such as centering, hole blockage, through holes, and process parameters, are discussed.

The article presents the results of numerical analyses and experimental research of the influence of various types of stators on a liquid flow through a centrifugal pump with a hole impeller. It is a continuation of authors research of cooperation pump stators with alternative types of impellers which work in ultra low specific speed. Hole impellers have become a significant alternative to classical ones in a range of extremely low specific speed n q <10. The aim of the research is to verify the quality as well as quantity of computer modeling results, and to estimate accuracy by examining the impact of a grid and a turbulence model with which the numerical simulations reflect the actual flow.Knowledge concerning construction of hydraulic elements of centrifugal pumps working in the range of parameters corresponding specific speed (n q <10) is insufficient. The outlet elements were tested in various configurations of constructional features. The complexity of the construction of the stator can significantly affect the manufacturing costs of pump unit.

The industry needs the rotodynamic pumps operating with ultra-low specific speed and relatively low flow rate more often. Designing of such structures on acceptable efficiency level is extremely difficult and require nonstandard approach to design as for example: drilled impeller or patented by author multi-piped impeller. Such pump elements are very easy to manufacture and operate with relatively high efficiency, but cavitation behavior is unknown. This paper focuses on experimental research in order to determine the cavitation characteristics of the drilled impellers and multi-piped impellers. The test rig was presented. Impeller models were made by means of SLS Rapid Prototyping methods. Additionally, CFD calculations were presented in order to determine static pressure distribution in the inlet sections of the investigated impellers.

The article presents the results of numerical calculations and experimental results of a flow through the orifice. Such a measuring device was built-into the ball valve that gave unique possibility of the orifice exchange without the pipeline disassemble. The advantages of using the prototypical solution has been described. This patented solution has been tested extensively for the durability and tightness. The article contains comparison between flow character in the case of single-hole orifice and a multi-nozzle one. The prototypical measuring device has been produced and assembled in compressed air system in the Power Plant Opole, that gave experimental verification of theoretical approach.

The article presents the results of experimental and numerical tests of a water turbine. As the object of the research the middle size Francis turbine, characterized by a middle value of specific speed, was taken into consideration. The primary aim of the realized project was to explain the occurrence of a high vibration level in a partial load operation. It was realized by the application of the superposition of experimental methods and a numerical simulation. The numerical results were verified on the basis of comparison with experimental results obtained for the real turbine. The numerical models were built with great accuracy to the reality and the flow was recognized, which allows to explain the reasons for random occurrence of high vibration in a draft tube and indicate a possibility of improvement of the analyzed object. The results of the numerical research such as distributions of velocity, pressure and vapor volume fraction in the passages were taken into consideration. The flow inside the Francis turbine and an outflow chamber were conscientiously analyzed. Pressure and velocity distribution as well as water surface structure were presented in the paper. Furthermore, the results numerical investigations helped to describe a cavitation rope vortex creation in the draft tube and the development of the air vortexes in the outlet chamber. Finally, the superposition of those phenomena was responsible for the deterioration of the turbine operation.

The paper presents the continuation of work devoted to the analysis of a brush seal with thermo-regulating bimetal elements aimed at thermal protection of a brush seal. This paper presents a method of determining the operating temperature of such a seal using the finite element method. It has been shown that building the seal according to the idea allows a significant reduction of its working temperature.

The paper presents new type of the semi-metallic gasket characterized with elastic core. Thanks to this solution more elastic recovery as well as more uniform contact stress distribution on the gasket’s surface were obtained which consequently caused that tightness level of the flange joint increased by 1000% in contrast to joint gasketed with traditional solution. The tightness characteristic of the traditional as well as new solution of the gaskets were determined experimentally and discussed.

The paper presents the method of design and strength analysis of the flange-gasketed-bolted joint. In the first part, analytical calculations were carried out. Their purpose was to determine the assembly torque of nuts to achieve the desired tightness. The flanged joint designated as DN100 PN40 with two different gaskets was taken into consideration. The analytical calculations were performed in accordance with the algorithm included in PN EN 1591-1. In the further step, the numerical calculations were carried out to support the analytical results. The outcome of these calculations were maps of the contact stress distribution on the gasket surface, estimation of safety factors of individual joint elements as well as determination of the flange rotation. Data from the numerical calculations were compared with the analytical results, which confirmed their satisfactory compliance. In the last stage, the experimental tests of the joint were carried out. The main results of the test were the measured values of the leakage level, tightening force of the bolt and estimated safety factors. An indirect result of the experimental measurements were maps of the stress distribution on the contact surface of the gasket, which were determined by means of the measuring film. Ultimately, based on the experimental results, it was found that the proposed analytical method of calculation and simulation of the joint by means of the finite element method was a very good tool for the design of the joint at the required tightness level.

The article deals with the description of the production programming of a robotic flange, which consists of outer conical, cylindrical surface, face area and internal threaded surfaces. For the modelling of a 3D model and the generation of production design, the Autodesk Inventor Professional 2018 software was used. To enter the semi-finished piece, select individual tools, cutting conditions, simulation and the NC program generation for RS Fanuc, the HSMPRO 2018 software extension was used. The circularity deviation was measured using the Roundtest RA 120 measuring device. The mean arithmetic values of roughness for the hole were: D = 126, Rz = 11.43 μm, Ra = 1.92 μm. The circularity deviation was 22.3 μm.

The paper analyzes static tests of pipe conveyors using various statistical indicators and points out the mutual interactions between individual roller stands. Individual measurements were performed on a physical model of a pipe conveyor, while the methodology and procedure were verified by experiments. 15 repetitions of the given series of measurements were selected, which was a compromise between time demands and statistical requirement. Normal contact forces on the individual rollers of three hexagonal roller stands acting on the conveyor belt for different tension forces in the static state (conveyor belt without movement and without transported material) were evaluated. The LabVIEW Signal Express 2010 program from the National Instruments Company was used to record the measured data. The measurements were evaluated by Microsoft Office Excel.

In terms of monitoring the material and volume flow of pipe conveyors, the conveyor is considered to be a volumetric machine that does not have a "self-defence" function - in most cases, material needs to be dosed and monitored in the critical parts of the conveyor for smooth transportation and quick detection of deficiencies and errors. Appropriate attachment of the material flow sensor to the pipe conveyor structure plays an important role for efficient material monitoring on the pipe conveyor belt. The paper specifies and subsequently analyzes selected methods of mounting an optical material flow monitor - the Bulkscan LMS511, based on the ratio index method by analyzing the advantages and disadvantages of individual variants. The optimal variant is modelled in the PTC Creo Parametric program and the estimated costs for its implementation are evaluated.

Integrated supply chains, due to their complexity, are vulnerable in relation to various types of risks, especially in the present turbulent market environment, characterised by increased demand for effectiveness of the individual logistic activities, extended customer service and decreased cost. The supply chain risks are represented by any threatening event that may unexpectedly disrupt or restrict material flow, or directly stop the scheduled logistic or manufacturing activities. Supply chain risk management includes risk identification, analysis and implementation of measures against potential risk consequences. This article describes supply chain management, risk elimination methods in the case of a technological breakdown and potential subsequent supply chain failure and application of the modified Failure Mode, Effects & Criticality Analysis (FMECA).

Intra-plant transport systems within their operation directly impact on the performance of production systems. For their effective operation, it is, therefore, necessary to realize evaluation of operational performance and effectivity. For the realization of this type of evaluation, in addition to a wide range of sensors that can be difficult for installation and operation, we can also use indirect methods that are equally able to provide reliable operational characteristics. Indirect analytical methods are presented above all by the approach which is based on the use of simulation methods. The method of computer simulation provides a wide range of options for the evaluation of efficiency and performance. The paper describes the use of a simulation model created in the program Tecnomatix Plant Simulation for analyzing the supply of production workplaces within the MilkRun system.

Intra-plant transport has an important role in the systems of enterprise logistics. At present, automated transport systems (AGV) are used for its efficient operation, with minimal operator attendance. For the proper and reliable functioning of such a transport system, there is currently a wide range of methods, of which the method of computer simulation is increasingly dominant. In the application, however, it is necessary to take into account that the functioning of AGV systems is a very demanding process with high demands on the used simulation software. Within the article, it will be described the use of the method of additional programming, as an effective tool in the creation of a simulation model of the AGV system for the need of its planning. The model presents the possibilities of increasing of the output of the analyzed production process to more than 70%, and at the same time it indicates insufficient use of workplaces that in one case reaches the value about 10%. The application of this model pointed to the reduction of the number of workplaces by one and with this related increase of output of other workplace.

Demand forecasting is very often used in production planning, especially, when a manufacturer needs in a longer production cycle to respond flexibly to market demands. Production based on longer-term forecasts means bearing the risk of forecast unreliability in the form of finished product inventory deficit or excess. The use of computer simulation allows us to improve the planning process and optimise the plan for the intended goal. This paper presents the use of quantitative forecasting and computer simulations to create the production plan. Two approaches to production plan creation are demonstrated in a model case study. Products are characterized by varying demand and are produced on a single production line in continuous operation. The first approach uses ARIMA(2,0,2) (Auto-Regressive Integrated Moving Average) prognostic method selected as the most reliable method based on MAPE (Mean Absolute Percent Error). The second method applies Monte Carlo simulations and optimisation. The aim of the plan optimisation is minimisation the total costs connected with line rebuilding and storage of products. The comparison of the two approaches shows that planning using computer simulations and optimisation leads to lower total costs.

This article focuses on the experimental verification of a mathematical derivation of Janssen’s theory, which describes the distribution of pressures within the bulk material and pressure distribution on the walls of storage facilities. The experimental verification is performed in two ways. The first is the real measurement of the load transfer in a bulk material cylinder and the second is similar to the detection of the load transfer through simulations using the DEM method. The aim is to compare the results of the theoretical calculation according to Janssen’s theory with the real measurement and a simulation of exactly the same model situation. At the beginning of any design or optimisation of existing transport or storage facilities, the most important is the analysis of the bulk material in the form of measurements of mechanical-physical properties. The analysis methods used are also described here. The pressure at the bottom of a storage container between the methods used showed negligible differences. From this finding, it can be concluded that the DEM method is a very suitable means for verifying the design of transport and storage facilities. The simulations provide important information and insights that can also be used to optimise existing transport or storage facilities.

In a parking house with KOMA TOWER computer-controlled automated parking system it happens that a control system is locked out of service after a pallet has failed to reach the required position during the shifting of pallets, loaded with cars, into rack cells. In this paper is described testing equipment designed by the Institute of Transport, Faculty of Mechanical Engineering, VŠB Technical University of Ostrava for the purpose of simulating the process of pallets shifting into the rack cells in order that the frequency of error messages from the control system during the automated process of cars positioning in rack cells in the parking house may be limited. The paper details two completed parts of the designed testing equipment which provide for the calibration of strain-gauge force transducers and for the detection of coil compressive spring compression in relation to acting pressure force. The description of the third, principal design part will be provided in the next paper, together with the experimentally measured acting forces which generate, in both horizontal and vertical directions, as a pallet brake pulley rolls along a brake haunch length.

This paper is devoted to the use of statistical methods to ensure the highest quality processes. Specifically, it deals with creating an application in MS Excel which evaluates standard statistical parameters and if the required process capability indices are complied with, then it is possible to proceed to SPC (statistical process control). The application was created in MS Excel using the Visual Basic for Application programming language. In addition to the required calculations, the application also generates forms with all important data. This application was designed to reduce reject rate and improve the production process in a contracting company.

The article deals with the issue of midsize businesses, their position within the association, and specifically determining the size and range of stocks in their ware-houses. A mathematical model is used and several examples explain the issue of calculating warehouse items.

Static stiffness is determined by one-sided loading and unloading of machine parts relative to the selected base. For each structure, there will be some loss of potential energy due to the dissipative forces that occur during the loading inside the structure. This loss is manifested in hysteresis in the stiffness diagram. A new approach to the assessment of static stiffness consists in gradual, bilateral loading and unloading of the structure through the effect of static forces of different magnitude. In this process, the stiffness hysteresis varies, depending on the intrinsic nature of the dissipative forces, a specific property suitable for assessing the condition of machines.

The article deals with the description of the production of a shaped part composed of an outer pyramid and cylindrical surface, of inner cylindrical surfaces of different diameters and of an inner tongue groove. It describes the proposed tools and tool holders resulting from the technological process. In order to meet the required tolerances and shape deviations for the given component, the CTX alpha 500 two-spindle multi-axis CNC lathe was chosen for its production. Its control system enables the workshop method of programming and simulation of individual operations in automatic mode or in block-by-block mode. The design of the selected CNC lathe enables the machining of rotary parts in one clamping, which is ensured by the right and left spindle with chucks. The surface quality of the pyramidal surface and the internal diameter of D18H8 was measured using a Hommel Etamic W5 roughness gauge. The measured roughness values for the hole were: D = 18H8, Rz = 3.007 μm, Ra = 0.729 μm and for the pyramidal surface: Rz = 1.527 μm and Ra = 0.329 μm.

The paper reports the experimental results of a study investigating the effect of different contents of a mineral filler on the rheological properties, p-v-T, of polypropylene. Using the pvT100 apparatus, we measured specific volume under isobaric cooling at different pressures for pure polypropylene and chalk-filled polypropylene (10 wt%, 20 wt% and 30 wt%). Next, we employed computer methods to determine the coefficients of a mathematical model describing the variations in specific volume in a function of temperature and pressure. The model was used in the numerical simulations of injection molding and shrinkage processes.

Additive manufacturing (AM) is a manufacturing process that allows for the creation of a physical object from a digital model. Additive manufacturing has a number of advantages over the conventional methods, inter alia the production of very complex machinery components, and a lower consumption of raw materials. Thanks to these advantages, the technology has been booming recently. The paper compares the advantages and disadvantages of additive technologies in the context of environmental impacts using Life Cycle Assessment (LCA). The paper describes the most important aspects of additive manufacturing, reviews the basic principles and phases of LCA method, including its application in AM, and outlines selected publications dealing with LCA and additive technologies. In conclusion, we recommend the most suitable methodologies to assess environmental impacts of additive technologies. To be specific, LCA is suitable to assess AM as for the material and energy flows, and in general, research in this field is considered highly promising.

Shock compression and expansion are phenomena which occur mainly in screw or vane compressors. They occur when there is an imbalance in the built-in and total pressure ratio. These are phenomena that have a negative impact on the operation of these machines and, in general, cause instability in operation, an increase in energy consumption and an overall worsening of the operational economy. The aim of this article is to present newly discovered information regarding making work processes of said compressors more effective, as in many cases, shock phenomena are subconsciously underestimated. The set aim was reached by creating an ideal simulation of isothermal compression of an ideal gas with the implementation of shock phenomena, which were performed on a screw compressor with the operating pressure 7 bar and a flow performance of 3 440 l min −1 . Based on the simulations performed, the hypotheses which set forth that the impact of shock phenomena ultimately leads to a sudden increase in compressor power consumption were confirmed. E.g. at 6 bar, the instantaneous power consumption increases by about 5.74% during shock compression and by about 55.95% during shock expansion. This paper deals with new insights and at the same time presents the follow-up research.

Intelligent conveyors include a large number of sensors and also signalling devices. So-called digital twin presents an advantage that creates a virtual image of a real conveyor. Simulation of the conveyor by simulation language can be an example of a tool of a conveyor virtual image. Simulation allows to test the proposed changes and in the case of functionality, to use the changes in the real operation of pipe conveyor. The paper presents the description of the simulated regression model of conveyor and realized simulation experiments within the regression model of pipe conveyor.