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The traffic capacity of a waterway on canalized rivers is usually determined by the transit time through the locks. Total transit time of a vessel through a lock is influenced by a number of aspects, including the time taken to open the lock gates, the time taken to fill and empty the lock and the time taken for vessels to enter and exit the lock. This paper deals with the optimization of lock approaches. If the navigation conditions in the lock approach are suitable, it is possible to ensure relatively easy manoeuvrability of vessels and the time interval to enter and exit the lock can be significantly reduced. The navigation conditions in the lock approach are influenced significantly by the flow conditions in the vicinity of the guard wall. The guard wall separates the lower and upper lock approaches from the gated weir and, if not designed appropriately, there can be significant flow velocity which tend to pull vessels toward the guard wall and weir. In addition to flow conditions, pilot experience, engine power and wind speed also affect the manoeuvrability of vessels in the lock approach. This paper presents a procedure to optimize the guard wall by achieving appropriate flow conditions in the lock approach using a mathematical 2D (depth-averaged) model. As a suitable measure, a flow-through multicell (ported) guard wall is proposed, which has flow openings between the cells designed below the draft level to limit the transverse flow velocity per vessel in the vicinity of the guard wall. The presented optimization procedure was verified on the case study of the Modrany lock in Prague (Czech Republic). The Modrany barrage was built in 1979-1987 on the Vltava River and at high flows the manoeuvrability of ships is considerably reduced with a decrease in the capacity of the waterway. The application of the proposed procedure led to the extension of the multicell guard wall with the application of flow-through openings. This solution made it possible to ensure significantly better flow conditions in the upper lock approach and was subsequently also verified in a physical model in the hydraulic laboratory. The implementation of this measure in situ is currently under preparation. The described technical solution has minimal impact on the architectural character of the lock and can therefore be used to increase the capacity of the historic locks on the Elbe-Vltava Waterway in the Czech Republic. The research was conducted as part of project no. DG18P02OVV004 entitled "Documentation and presentation of technical cultural heritage along the Elbe-Vltava Waterway" within a support programme for applied research and experimental development of national and cultural identity, funded by the Ministry of Culture of the Czech Republic. [ABSTRACT FROM AUTHOR]

The traffic capacity of a waterway on canalized rivers is usually determined by the transit time through the locks. Total transit time of a vessel through a lock is influenced by a number of aspects, including the time taken to open the lock gates, the time taken to fill and empty the lock and the time taken for vessels to enter and exit the lock. This paper deals with the optimization of lock approaches. If the navigation conditions in the lock approach are suitable, it is possible to ensure relatively easy manoeuvrability of vessels and the time interval to enter and exit the lock can be significantly reduced. The navigation conditions in the lock approach are influenced significantly by the flow conditions in the vicinity of the guard wall. The guard wall separates the lower and upper lock approaches from the gated weir and, if not designed appropriately, there can be significant flow velocity which tend to pull vessels toward the guard wall and weir. In addition to flow conditions, pilot experience, engine power and wind speed also affect the manoeuvrability of vessels in the lock approach. This paper presents a procedure to optimize the guard wall by achieving appropriate flow conditions in the lock approach using a mathematical 2D (depth-averaged) model. As a suitable measure, a flow-through multicell (ported) guard wall is proposed, which has flow openings between the cells designed below the draft level to limit the transverse flow velocity per vessel in the vicinity of the guard wall. The presented optimization procedure was verified on the case study of the Modrany lock in Prague (Czech Republic). The Modrany barrage was built in 1979-1987 on the Vltava River and at high flows the manoeuvrability of ships is considerably reduced with a decrease in the capacity of the waterway. The application of the proposed procedure led to the extension of the multicell guard wall with the application of flow-through openings. This solution made it possible to ensure significantly better flow conditions in the upper lock approach and was subsequently also verified in a physical model in the hydraulic laboratory. The implementation of this measure in situ is currently under preparation. The described technical solution has minimal impact on the architectural character of the lock and can therefore be used to increase the capacity of the historic locks on the Elbe-Vltava Waterway in the Czech Republic. The research was conducted as part of project no. DG18P02OVV004 entitled "Documentation and presentation of technical cultural heritage along the Elbe-Vltava Waterway" within a support programme for applied research and experimental development of national and cultural identity, funded by the Ministry of Culture of the Czech Republic. [ABSTRACT FROM AUTHOR]

Recently, there has been a growing interest in ecology and the environment, which is why wooden buildings are becoming increasingly popular. In the Czech Republic, there are opinions that the fire safety design of timber buildings is too strict, mainly because of the restrictive fire height (≤ 12 m). There are more requirements that seem to be too high comparing to noncombustible buildings, for example type of construction system, fire load, degree of fire safety, fire resistance of building structures, fire separation or falling out of burning parts. These requirements are briefly described in this paper. Another part of the paper is devoted to a case study. This case study consists of a building with offices and shops. Requirements of Czech regulations for fire safety design of timber buildings are implemented in this case study together with regulations of selected foreign countries (Great Britain, Canada, USA and Austria) to see if Czech design is strict or not. Graphical results (height of building and fire separation) are given at the end. [ABSTRACT FROM AUTHOR]

The watertightness is a crucial parameter in the case of concrete structures exposed to effects of water. Number of old concrete structures suffer from the massive water ingress into the underground parts, which negatively influences the operation condition of the building and the long-term durability of used material. This contribution deals with rehabilitation of water leakage in the fortress T-St-S 73 at the Stachelberg artillery fortress, which was built in 1930s in Czech Republic, near the borders with Poland. The paper summarizes the finding of the local survey, describes the causes of long-term leakage form the exterior into the structure and used way of rehabilitation. With respect to the massive water seepage it was necessary to develop new cement-based composite, which was applied at the damaged places, to seal the problematic and weak part. The material characterization of used composite and their time-progress for rehabilitation of the historical object is documented in the paper. The whole procedure and individual steps of the remediation intervention are described. [ABSTRACT FROM AUTHOR]

Consideration of uncertainties in bridge structural engineering is a growing topic because it provides valuable information on the reliability of bridges in time while addressing life-cycle aspects. Utilization of nonlinear finite element method (NLFEM) and Monte Carlo (MC) type simulation is essential for modelling of the concrete bridge random behaviour and its reliability assessments. Generally, a physical problem can be represented by a mathematical model, which depends on input parameters (material characteristics, geometry, etc.). The aim of the stochastic analysis is to propagate uncertainties through a mathematical model to gain statistical information from the output as well as information about the sensitivity of the mathematical model to uncertainties in input variables. However, in bridge engineering, the mathematical model can be quite complex and uncertainty propagation solved by classical MC approach is very difficult to perform as MC type simulation involves large number of numerical evaluations of structural response. Therefore, advanced statistical and reliability techniques, including meta-modelling, have to be applied. The paper describes methodology of such integrated approach for a routine complex assessment utilizing developed software tools and practical application of the approach for selected case studies of concrete bridges from Czech Republic. [ABSTRACT FROM AUTHOR]

An increasing number of end-of-life tires is becoming a global issue that requires finding new ways of recycling and recovery of tire-related waste. In the Czech Republic, about 70 thousand tons of end-of-life tires were recollected in 2019. They were mainly stored, or alternatively reused in the raw or processed state in various ways, such as an alternative fuel for cement works, or within the production of asphalt and cementitious materials. With respect to an expected increase of waste tires, the processed waste can find other meaningful applications, such as utilization in construction elements with good acoustic performance. The paper is focused on the acoustic characterization of two types of boards based on tire waste. Acoustic experiments of tire-fluff and sandwich gypsum/tire-fluff boards were performed in the system of the small acoustic chambers designed for fast comparison of acoustic insulation ability of construction elements. The noise reduction index was determined with respect to a small volume of the receiving chamber in the frequency range of 315 Hz – 5 kHz, 1/3 octave resolution, by using an 85 dB sound pressure level in the transmitting chamber. The average noise reduction index of tire-fluff board in the studied frequency spectrum was 54.1 dB which was a 14.6 dB improvement compared to the tire-fluff board. [ABSTRACT FROM AUTHOR]

This paper focuses on large-scale irrigation embedded in the urban landscape. During a century the city agglomerations are growing. There are enormous high temperatures on summer days. City plants have a lack of water and life in a city seems inhospitable. The main goal is to find a new concept of the large-scale irrigation system using a minimum of added energy. The system deals with rainwater harvesting and distribution in populated areas. Water is harvested from the roofs in a specific area near a possible place of accumulation. The pipeline system is located underground and protected against vandalism. The whole project should consist of an analysis of the zoning plan of the selected locality too. It focuses on the Czech Republic, especially of Brno. The design deals with the entire system, from the accumulation of harvested water to the distribution of watering to the root zone of plants. There are many technical solutions of accumulation systems (as a flexible collapsible bladder) or systems water distribution to plant roots. The proposed distribution network is calculated using the current known equations in the second part of the paper. The calculation is finished by choosing suitable dimensions of the pipeline network that can be used. In addition, the article suggests possible areas for the new planting of greenery in Brno. Finally, suitable trees for the urban landscape are mentioned. [ABSTRACT FROM AUTHOR]

In core areas of the construction industry, such as e.g., the areas of housing, power engineering and transport, a significant amount of construction minerals is consumed. In the Czech Republic, there are approximately 20·109 tons of verified reserves of construction minerals and about 55·106÷60·106 tons of them are extracted annually. Mined minerals must be first treated (crushed, sorted, etc.) before being used in the production of concretes, mortars and blocks, which places high demands on handling and transporting them. For the vertical technological transport of large quantities of materials in mining, preparation and processing plants, quite often, with very constricted working surfaces, a special belt conveyor design known as 'HAC System' or 'Sandwich belt conveyor' can be used. This paper presents the structural design of a spring mechanism, the purpose of which is to create a compressing force acting on the top belt of a vertical belt conveyor. The individual grains of transported material, supported by the bottom belt and covered by the top one, are subjected to normal forces induced by compression force. Friction forces are then generated between the contact surfaces of the material grains and both conveyor belts. For the safe operation and trouble-free transport of granular materials, the conveyor idler rollers, attached to the frames of the segment, must be pressed against the surface of the conveyor belt by a force the size of which does not fall below the limit value. The minimum volume of the contact force must ensure that the grains of the material located in the space between the top and bottom belts, travelling in the vertical section of the belt conveyor, do not move backwards from the movement of the conveyor belts due to their own weight. A laboratory testing device to test top belt compression uses two types of compression coil springs, each one with different values of spring stiffness. The theoretically calculated results and laboratory-obtained values of the compressive force for the two types of redesigned coil springs are listed in Table 1 and Table 2. The obtained results of the experimentally measured compression forces for the given type of spring, generated by vertical movement of the vertically sliding segment called the 'Testing equipment of the compression mechanism for the top belt', which is proportional to the height of the cross-section of the belt filling, are presented in Table 3 and Table 4. [ABSTRACT FROM AUTHOR]

The paper describes the hybrid modelling of the design of the lock filling and emptying (F/E) system. It is a method of hybrid modelling, which combines physical and numerical modelling methods of flow. Hybrid modelling is mainly used to solve the hydraulic flow of a water complex in hydraulic structures. Optimizing and rebuilding the physical model is laborious and does not show all the results. The use of a numerical model allows to optimize only a part of the structure with using measurements on a physical model. The main advantages of hybrid modelling are the high reliability of results and the possibility of interpreting results that are not visible on the physical model. Within the project preparation of the Děčín lock, extensive research was carried out on the physical model of the lock. The aim of the research was to optimize the F/E system of the lock of long culverts. Based on the measurements on the physical model, an optimization of the filling system was necessary. Subsequently, the F/E system was optimized to reduce hydraulic losses using a CFD model. The optimized F/E system is up to 12% more efficient than the project preparation design. The hybrid modelling method can be used to increase the capacity of existing historic locks on the Elbe-Vltava Waterway (Czech Republic) without impacting the architectural character of the locks. The research was conducted as part of project no. DG18P02OVV004 entitled "Documentation and presentation of technical cultural heritage along the Elbe-Vltava Waterway" within a support programme for applied research and experimental development of national and cultural identity, funded by the Ministry of Culture of the Czech Republic. [ABSTRACT FROM AUTHOR]

Today, cities are exposed to many challenges and are looking for new efficient solutions that will make existing infrastructure lighter, improve public space and promote sustainable modes of transport. The task of contemporary urban planning and municipal engineering is to provide transport infrastructure to citizens that will save time while being pleasant, comfortable, and environmentally friendly. A significant part of urban sustainability and viability lies in reducing the need for transport and creating quality networks of walking rolutes, cycling routes, and support for public transport. The main goal of the survey is to identify and describe mobility behavior and needs and the associated views and attitudes of the senior population in Small-Scale Cities. Subsequently, detect opportunities for improvement in urban transport. The paper presents the results of a case study of the perception of urbanized public space from the perspective of mobility and transport in the small town of Chotebor in the Czech Republic. [ABSTRACT FROM AUTHOR]

Barrages on watercourses are usually designed as multi-purpose structures that were built to navigate rivers for water transport, protect the area from flooding, enable water withdrawals and utilize the hydropower potential. In the layout of the low head barrage a run-of-river hydropower plants (HPPs) are usually designed. The efficiency of operation of HPPs is significantly affected by the barrage layout and by the velocity conditions in the intake structure. The efficiency of HPPs can be adversely affected by inappropriate hydrodynamic design of the individual elements, which include the coarse screens and the submerged wall as protection against coarse debris, the sill at the entry to the intake structure to exclude the bed material, the intake channel and the fine screens. If these elements are not properly designed, high pressure losses are generated, leading to a reduction in the efficiency of the HPP. In addition to pressure losses in the intake structure, the homogeneity of the velocity field in the inlet profile upstream of the turbines has been shown to affect the efficiency of the HPP. In the case of an inhomogeneous velocity field, flow disturbances occur which have a demonstrable impact on the efficiency of the turbines. Nowadays, the method of physical and mathematical modelling is often used for the hydraulic design of the suitable shape of the intake structure as well as other HPP elements. The present paper describes the use of 3D mathematical modelling for the optimisation of the intake structure of a low head HPP with respect to the homogeneity of the velocity field in the control profile upstream of the turbine inlet. There are a number of objective criteria for evaluating the homogeneity of the velocity field, which have been validated by measurements on real HPPs. The procedure is verified for the case of the HPP intake of the planned Děčín barrage on the Elbe River. Optimal velocity conditions were ensured by the use of guide pillars in the profile of coarse screens and entry sill. The resulting optimized shape was verified using the physical model. Currently, there are many HPPs at existing barrages with unsatisfactory hydraulic conditions in the intake area. The described technical solution for the application of guide pillars in the intake has minimal impacts on the architectural character of the barrage and can therefore be used to increase the efficiency of historic hydropower plants with high cultural value. The research was conducted as part of project no. DG18P02OVV004 entitled "Documentation and presentation of technical cultural heritage along the Elbe-Vltava Waterway" within a support programme for applied research and experimental development of national and cultural identity, funded by the Ministry of Culture of the Czech Republic. [ABSTRACT FROM AUTHOR]

As part of the National and Cultural Identity Programme administered by the Ministry of Culture of the Czech Republic, the project "Documentation and Presentation of Technical Cultural Heritage on the Elbe-Vltava Waterway (EVW)" has been underway since the year 2018. The project systematically surveys the historical development of EVW navigability since the beginning of the 19th century. The paper focuses on reconstructions and refurbishments that have been realized in the 21st century and discusses the future challenges of this unique waterway. Technical modifications in the infrastructure of the waterway are compartmentalized into four main categories. Firstly, they are the modernization of the technologies of locks and hydroelectric power plants built more than 80 years ago. The second category encompasses the construction of new hydropower plants in localities where the energy potential has not yet been used. The installed capacity at the EVW has increased by more than 30 MW of renewable energy during the last 20 years. The third category contains improving parameters and capacity of the waterway. That covers modifications of the fairway and increases underpass heights under bridges. The last group contains the constructions of new recreational berths, which complement the existing infrastructure on the waterway and opens up the opportunity for more intensive recreational use. Concerning further expected development, other investment projects to increase the potential use of the Elbe-Vltava waterway are preparing. The presented future projects at EVW represent a unique social challenge and help to fulfill the meaning and purposes of sustainable transport infrastructure built for more than the purposes of sustainable transport infrastructure built for more than 150 years. [ABSTRACT FROM AUTHOR]

The decisive parameter of every project is its price and its adequacy to the expected benefits. The investor decides whether to implement the project or withdraw from it based on its calculation. He makes a so-called investment decision. The planned goal of the project and its duration are relatively constant parameters. The most expensive part of a construction project is the construction work implementation. The price is determined by the budget, that is, by valuing the bill of quantities of individual structures and works. Many months or years can pass between the moment of the construction appreciation and its actual implementation, especially for large projects. The current price of resources used at the time of implementation is affected by the fluctuation of the price level, especially of building materials and built-in products. Therefore, the final price of the construction project may differ significantly from the budget price. A suitable tool for the correct determination of the price of the construction structure and works implemented is the adjustment of the budget price by multiplying it by a coefficient that reflects the price level development - the so-called price index. The use of a reliable source of indices ensures that the investor does not overpay for the project (the price is not excessive) and that the contractor does not lose money (makes the expected profit). In the Czech Republic, the Czech Statistical Office calculates and publishes quarterly price indices for construction structures and works. The contracting parties (the client and the contractor) may agree on the exact conditions for the use of price indices in the construction contract. This concerns in particular their structure according to the classification used and the determination of the time interval between the budget calculation and the invoicing for the work carried out. The article describes the methodology of surveying construction work prices and calculating price indices by the CZSO and the structure and periodicity of their publications. Furthermore, a method of using price indices to update billing prices is proposed. The development of the prices in the last few years is shown in the examples of specific construction structures. The paper is extended by the results of a questionnaire survey in construction companies aimed at finding out whether and how they use construction price indices. [ABSTRACT FROM AUTHOR]

In core areas of the construction industry, such as e.g., the areas of housing, power engineering and transport, a significant amount of construction minerals is consumed. In the Czech Republic, there are approximately 20·109 tons of verified reserves of construction minerals and about 55·106÷60·106 tons of them are extracted annually. Mined minerals must be first treated (crushed, sorted, etc.) before being used in the production of concretes, mortars and blocks, which places high demands on handling and transporting them. For the vertical technological transport of large quantities of materials in mining, preparation and processing plants, quite often, with very constricted working surfaces, a special belt conveyor design known as 'HAC System' or 'Sandwich belt conveyor' can be used. This paper presents the structural design of a spring mechanism, the purpose of which is to create a compressing force acting on the top belt of a vertical belt conveyor. The individual grains of transported material, supported by the bottom belt and covered by the top one, are subjected to normal forces induced by compression force. Friction forces are then generated between the contact surfaces of the material grains and both conveyor belts. For the safe operation and trouble-free transport of granular materials, the conveyor idler rollers, attached to the frames of the segment, must be pressed against the surface of the conveyor belt by a force the size of which does not fall below the limit value. The minimum volume of the contact force must ensure that the grains of the material located in the space between the top and bottom belts, travelling in the vertical section of the belt conveyor, do not move backwards from the movement of the conveyor belts due to their own weight. A laboratory testing device to test top belt compression uses two types of compression coil springs, each one with different values of spring stiffness. The theoretically calculated results and laboratory-obtained values of the compressive force for the two types of redesigned coil springs are listed in Table 1 and Table 2. The obtained results of the experimentally measured compression forces for the given type of spring, generated by vertical movement of the vertically sliding segment called the 'Testing equipment of the compression mechanism for the top belt', which is proportional to the height of the cross-section of the belt filling, are presented in Table 3 and Table 4. [ABSTRACT FROM AUTHOR]

The paper describes the hybrid modelling of the design of the lock filling and emptying (F/E) system. It is a method of hybrid modelling, which combines physical and numerical modelling methods of flow. Hybrid modelling is mainly used to solve the hydraulic flow of a water complex in hydraulic structures. Optimizing and rebuilding the physical model is laborious and does not show all the results. The use of a numerical model allows to optimize only a part of the structure with using measurements on a physical model. The main advantages of hybrid modelling are the high reliability of results and the possibility of interpreting results that are not visible on the physical model. Within the project preparation of the Děčín lock, extensive research was carried out on the physical model of the lock. The aim of the research was to optimize the F/E system of the lock of long culverts. Based on the measurements on the physical model, an optimization of the filling system was necessary. Subsequently, the F/E system was optimized to reduce hydraulic losses using a CFD model. The optimized F/E system is up to 12% more efficient than the project preparation design. The hybrid modelling method can be used to increase the capacity of existing historic locks on the Elbe-Vltava Waterway (Czech Republic) without impacting the architectural character of the locks. The research was conducted as part of project no. DG18P02OVV004 entitled "Documentation and presentation of technical cultural heritage along the Elbe-Vltava Waterway" within a support programme for applied research and experimental development of national and cultural identity, funded by the Ministry of Culture of the Czech Republic. [ABSTRACT FROM AUTHOR]

Today, cities are exposed to many challenges and are looking for new efficient solutions that will make existing infrastructure lighter, improve public space and promote sustainable modes of transport. The task of contemporary urban planning and municipal engineering is to provide transport infrastructure to citizens that will save time while being pleasant, comfortable, and environmentally friendly. A significant part of urban sustainability and viability lies in reducing the need for transport and creating quality networks of walking rolutes, cycling routes, and support for public transport. The main goal of the survey is to identify and describe mobility behavior and needs and the associated views and attitudes of the senior population in Small-Scale Cities. Subsequently, detect opportunities for improvement in urban transport. The paper presents the results of a case study of the perception of urbanized public space from the perspective of mobility and transport in the small town of Chotebor in the Czech Republic. [ABSTRACT FROM AUTHOR]

Barrages on watercourses are usually designed as multi-purpose structures that were built to navigate rivers for water transport, protect the area from flooding, enable water withdrawals and utilize the hydropower potential. In the layout of the low head barrage a run-of-river hydropower plants (HPPs) are usually designed. The efficiency of operation of HPPs is significantly affected by the barrage layout and by the velocity conditions in the intake structure. The efficiency of HPPs can be adversely affected by inappropriate hydrodynamic design of the individual elements, which include the coarse screens and the submerged wall as protection against coarse debris, the sill at the entry to the intake structure to exclude the bed material, the intake channel and the fine screens. If these elements are not properly designed, high pressure losses are generated, leading to a reduction in the efficiency of the HPP. In addition to pressure losses in the intake structure, the homogeneity of the velocity field in the inlet profile upstream of the turbines has been shown to affect the efficiency of the HPP. In the case of an inhomogeneous velocity field, flow disturbances occur which have a demonstrable impact on the efficiency of the turbines. Nowadays, the method of physical and mathematical modelling is often used for the hydraulic design of the suitable shape of the intake structure as well as other HPP elements. The present paper describes the use of 3D mathematical modelling for the optimisation of the intake structure of a low head HPP with respect to the homogeneity of the velocity field in the control profile upstream of the turbine inlet. There are a number of objective criteria for evaluating the homogeneity of the velocity field, which have been validated by measurements on real HPPs. The procedure is verified for the case of the HPP intake of the planned Děčín barrage on the Elbe River. Optimal velocity conditions were ensured by the use of guide pillars in the profile of coarse screens and entry sill. The resulting optimized shape was verified using the physical model. Currently, there are many HPPs at existing barrages with unsatisfactory hydraulic conditions in the intake area. The described technical solution for the application of guide pillars in the intake has minimal impacts on the architectural character of the barrage and can therefore be used to increase the efficiency of historic hydropower plants with high cultural value. The research was conducted as part of project no. DG18P02OVV004 entitled "Documentation and presentation of technical cultural heritage along the Elbe-Vltava Waterway" within a support programme for applied research and experimental development of national and cultural identity, funded by the Ministry of Culture of the Czech Republic. [ABSTRACT FROM AUTHOR]

As part of the National and Cultural Identity Programme administered by the Ministry of Culture of the Czech Republic, the project "Documentation and Presentation of Technical Cultural Heritage on the Elbe-Vltava Waterway (EVW)" has been underway since the year 2018. The project systematically surveys the historical development of EVW navigability since the beginning of the 19th century. The paper focuses on reconstructions and refurbishments that have been realized in the 21st century and discusses the future challenges of this unique waterway. Technical modifications in the infrastructure of the waterway are compartmentalized into four main categories. Firstly, they are the modernization of the technologies of locks and hydroelectric power plants built more than 80 years ago. The second category encompasses the construction of new hydropower plants in localities where the energy potential has not yet been used. The installed capacity at the EVW has increased by more than 30 MW of renewable energy during the last 20 years. The third category contains improving parameters and capacity of the waterway. That covers modifications of the fairway and increases underpass heights under bridges. The last group contains the constructions of new recreational berths, which complement the existing infrastructure on the waterway and opens up the opportunity for more intensive recreational use. Concerning further expected development, other investment projects to increase the potential use of the Elbe-Vltava waterway are preparing. The presented future projects at EVW represent a unique social challenge and help to fulfill the meaning and purposes of sustainable transport infrastructure built for more than the purposes of sustainable transport infrastructure built for more than 150 years. [ABSTRACT FROM AUTHOR]

The decisive parameter of every project is its price and its adequacy to the expected benefits. The investor decides whether to implement the project or withdraw from it based on its calculation. He makes a so-called investment decision. The planned goal of the project and its duration are relatively constant parameters. The most expensive part of a construction project is the construction work implementation. The price is determined by the budget, that is, by valuing the bill of quantities of individual structures and works. Many months or years can pass between the moment of the construction appreciation and its actual implementation, especially for large projects. The current price of resources used at the time of implementation is affected by the fluctuation of the price level, especially of building materials and built-in products. Therefore, the final price of the construction project may differ significantly from the budget price. A suitable tool for the correct determination of the price of the construction structure and works implemented is the adjustment of the budget price by multiplying it by a coefficient that reflects the price level development - the so-called price index. The use of a reliable source of indices ensures that the investor does not overpay for the project (the price is not excessive) and that the contractor does not lose money (makes the expected profit). In the Czech Republic, the Czech Statistical Office calculates and publishes quarterly price indices for construction structures and works. The contracting parties (the client and the contractor) may agree on the exact conditions for the use of price indices in the construction contract. This concerns in particular their structure according to the classification used and the determination of the time interval between the budget calculation and the invoicing for the work carried out. The article describes the methodology of surveying construction work prices and calculating price indices by the CZSO and the structure and periodicity of their publications. Furthermore, a method of using price indices to update billing prices is proposed. The development of the prices in the last few years is shown in the examples of specific construction structures. The paper is extended by the results of a questionnaire survey in construction companies aimed at finding out whether and how they use construction price indices. [ABSTRACT FROM AUTHOR]

The paper is devoted on the wage differences between men and women. It aims to decompose the gender pay gap in the Czech Republic applying the selected variants of Oaxaca-Blinder decomposition, estimate explained and unexplained part of gender pay gap and compare and discuss of estimation results. Using the micro-data from the European Union Statistics on Income and Living Conditions, the estimated raw gender pay gap is 0.23. Three variants of Oaxaca-Blinder decomposition are applied to decompose the wage differences. The results of individual variants vary significantly. The different characteristics of men and women allow to explain 8 - 40 percent of gender pay gap depending on the applied variant of decomposition. The vast majority of wage differences remains unexplained and represents the upper limit of wage discrimination against women. [ABSTRACT FROM AUTHOR]

Freezer and refrigeration plants are among the highest consumers of electric energy because they must provide sufficient cooling capacity. At present, the technical standard for design, the European document for the technical approval of EOTA and the recommendations of refrigeration and logistics associations have to be applied to this area in the conditions of the Czech Republic. The recommendations focus on efficient energy consumption, targeting energy fuels, reducing CO2 emissions, which helps to suppress global warming as a result of climate change. The paper demonstrates the degree of energy savings by numerical modeling due to the shielding of solar radiation acting on the perimeter cladding by structural modification of the outer overhanging façade with a ventilated air layer. [ABSTRACT FROM AUTHOR]

The Elbe River is navigable in the Czech Republic from Pardubice to the Czech/German border. From Pardubice to Ústí nad Labem, the Elbe is navigable by a cascade of 24 weirs. The last 42 km of the Elbe River between Ústí nad Labem and the Czech/German border are navigable only by historical river training works. The aim of this paper is to identify and map problematic sections with low water depths that restrict navigation. These sections are dangerous at low flow rates when the navigation depth is low and ships can navigate with limited draft. This reduces the capacity of the waterway. A 2D mathematical model is used to identify sections with low navigation depth. In the first phase of the research, it is necessary to define an outlet boundary condition at the Czech/German border. In the second phase, the 2D mathematical model is calibrated for the measured water levels and the corresponding flow rates. In the last phase of the research, problem areas with low navigation depth at low flow rates are identified. Based on the identification, it is possible to design river training works in this section of the waterway. [ABSTRACT FROM AUTHOR]

The modernization of railway lines represents a very important part of the railway infrastructure development. Railway line reconstruction and revitalization projects bring a number of positive impacts - benefits despite the negative impacts in the form of temporary traffic restriction on the lines or common relatively high investment costs. While the benefits in the form of operating cost savings, transport time reduction or negative environmental impact mitigation are usually included in the economic analysis evaluating the project economic efficiency, benefits in the form of increased railway safety and reliability usually closely related to these modernisation projects are not currently included in the economic analysis. The paper focuses on the presentation of a partial output of a research project, which addresses the evaluation of increasing the railway line safety and reliability due to the implementation of railway infrastructure modernization projects. In 2020, a paper presented at the 20th SGEM Green conference in Vienna addressed the impacts of railway line reconstruction implementation on the frequency of occurrence incidence on the railway network. 33 representative projects implemented in the Czech Republic were selected for impact assessment. The subject of this article is to analyse in more detail the impact of the implementation of these projects, especially in relation to occurrence (OC) classification according to the Czech Railway Administration (SŽ) s.o. methodology. [ABSTRACT FROM AUTHOR]

Construction industry can strongly affect the state economy. It is also an industry which is very sensitive to shock e.g. in the forms of economic crises. The great economic crisis, which started in 2008, had a great impact on this industry, and many enterprises operating in this industry were in danger of bankruptcy. However, compared to real economy, the construction market shows considerable inertia. Also, the current state affected by the COVID-19 pandemic is causing the worldwide decline in the demand for constructing new real estates and thus the stagnation of the construction industry. The objective of the paper submitted is to provide information on the development of construction industry in the Czech Republic in the years 2000-2020. The paper submitted deals primarily with the volume and overall amount of construction in the period specified above. To describe the development of the construction industry, data published mainly by the Czech Statistical Office, which keeps statistics by relevant categories of buildings. The basic principle is the classification of buildings by individual types and then by structures. The paper is divided into four parts dealing with the construction of houses, construction of apartment buildings, construction of non-residential buildings, and another parameter was the number of building permits in the monitored period. The performed analysis showed that the given period is a period of development of wooden constructions and application of other than conventional construction materials. There was also confirmed the inertia of the construction market compared to the real economy, where the peaks of the construction industry were always in the years of crisis, while the decline was always in the following years after the crisis, which is given mainly by the long cycles. The presented data are beneficial also mainly for construction companies, which can use them for better prediction of demand and management of resource capacity. [ABSTRACT FROM AUTHOR]

The paper deals with the problem of the occurrence of volatile organic compounds in the work environment, specifically in administrative public buildings in the context of the quality of the indoor environment (IAQ). The importance of indoor air quality has become an interest in research and development in the last 10 years, mainly due to the increasing quality of the airtight envelope of the building and the prevailing trend of forced ventilation. Indoor air quality is directly related to Sick Building Syndrome (SBS). The occurrence of VOC emissions within 10 selected office buildings in the South Bohemian Region in the Czech Republic is demonstrated in the practical case study. Detection of volatile organic compounds was performed using ultra-fast electronic zNose Model 4200 Analyzer based on gas chromatography with patented SAQ detector. The results of the case study demonstrate how important a quality element and the necessary implementation of the building and the design of the indoor working environment is. [ABSTRACT FROM AUTHOR]

The issue of public space in cities has recently become an increasingly discussed motive not only among architects, but also politicians and ordinary citizens. This is a topic that reflects the satisfaction and quality of life of all residents. Public space can be characterized as a space accessible to people at any time of day, designed for a wide range of different age groups, social classes, genders, and races. The perception of urban space by its inhabitants is an important part of research into urban structure and spatial planning. The process of mental mapping makes it possible to define potentially dangerous or otherwise critical areas of cities. Mental maps could reveal the specifics of fear of a defined group of people, including their reasons. Addressed identification of stressors is a key basis for increasing urban satisfaction and security. The paper presents a case study of positive and negative localities based on mental mapping in a typically medium-sized city in the Czech Republic, in Chotěboř. [ABSTRACT FROM AUTHOR]

PISA examines the acquired knowledge and skills of 15-year-old students at the end of their compulsory education. Science literacy has been the major area tested in the PISA 2015 survey for the second time in its history. Therefore, increased attention was paid to the major area in the PISA 2015 questionnaire survey too. The paper presents some results of the data analysis of the PISA 2015 survey from student and teacher questionnaires. The main focus is given to questions related to teaching methods used in scientific subjects and students' interest in science. If the same or similar questions were part of any previous PISA survey, the development of responses throughout the surveys is presented in graphs and tables as well. Next year, due to the pandemics, the postponed PISA survey focused primarily on mathematics will be held. Students who have undergone distance learning for a long time will be assessed in the survey. Certainly, it will be interesting to compare the development of students' performance in cognitive tests as well as their responses in questionnaires. [ABSTRACT FROM AUTHOR]

Experiments and active and inquiry-based learning are important features of both formal and informal in-service physics teacher training in the Heureka and Elixir to Schools projects in the Czech Republic. Traditionally, the activities of these projects relied heavily on personal contacts and direct interaction with teachers who actively performed experiments, constructed simple tools, and learned using an inquiry-based approach at the seminars. However, restrictions due to the Covid pandemic prevented direct contact with teachers since spring 2020. Nevertheless, it appears that real experiments done by participants, inquiry and active work can be maintained even in the restricted format of online seminars. The aim of this paper is to describe and summarize positive experience gained from various types of such seminars. [ABSTRACT FROM AUTHOR]

The coronavirus pandemic and the associated school closure have had a very significant impact on education in virtually all types of schools. In my paper, I will try to collect and summarize the views of physics teachers in the Czech Republic involved in the Heureka project on the negative consequences of the transition to online education. However, I would also like to focus on whether they consider some of what they and their students have experienced to be a challenge or a chance for further development. I also wanted to find out from the teachers what they want to keep in full-time teaching from what they have learned in connection with distance learning. [ABSTRACT FROM AUTHOR]

Diffusion equations in multicomponent environments, as parabolic evolutionary systems, have many physical and engineering applications; another their application was accentuated in 2020 due to the Covid19 infection. This short paper demonstrates the possibility of numerical analysis of direct and inverse problems of this type using some algorithms from computational heat, mass, etc. transfer, with special nonlinear terms originated in mathematical biology. One simple example sketches the benefits and hazards of such prediction for the MATLAB-based analysis of readily available Covid19 spread data from the Czech Republic. [ABSTRACT FROM AUTHOR]

In the Czech Republic, approximately 39,000 cultural monuments are registered of which some are still actively exploited. Their effective heating is a prerequisite for a favorable indoor environment in winter with respect to climatic conditions in the region of Central Europe. Given the usability of historical buildings in the present, it is very important to address appropriate thermal insulation solutions, which would be sufficiently functional, safe, and acceptable with respect to the protection of the historical value of such buildings. Taking into consideration the unsuitability of application of external thermal insulation, it is necessary to look for a suitable composition of the structure with interior thermal insulation. To achieve the best performance of a particular solution, it is important to carry out calculations based on experimentally determined input parameters of all involved construction materials and parameters defining the indoor and outdoor environment. Based on such calculations, expert indicators can be identified and benefits of the energy balance improvement of the thermal-insulated case in comparison with the one non-insulated can be assessed. The paper introduces the web-based expert system developed at the Department of Materials Engineering and Chemistry, Faculty of Civil Engineering, CTU in Prague which was designed to compare energy benefits gained by the application of various types of interior thermal insulations in historical buildings. Such a tool provides 31 expert indicators which were calculated for a wide amount of 3-layered and 4-layered constructions with respect to the climatic data from 64 different places in the Czech Republic. [ABSTRACT FROM AUTHOR]

Ceramic building elements have made a great progress recently that led to a significant improvement of their thermal and mechanical properties. This progress has been conditioned by precise knowledge of properties of raw materials entering the production process. Chemical composition, phase composition and particle size distribution represent the most significant characteristics that affect the subsequent processing of raw materials as well as their workability. In this paper experimental characterization of a brick clay from deposit Hevlin, Czech Republic, that is supposed to be used as a raw material for the brick industry, is presented. Using XRF spectroscopy, laser diffraction analysis, XRD diffractometry, and thermogravimetry, the key characteristics are determined. The analysis reveals that major part of particles is between 5 and 20 µm and illite-smectite is the most dominant clay mineral. The chemical composition shows the highest amount of Si02 (44.2%), Al203 (23.5%) and Ca0 (11.7%). These parameters predispose the clay to be successfully used in the brick production process. [ABSTRACT FROM AUTHOR]