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Flexural vibration (FV), torsional vibration (TV), static torsion (ST), longitudinal vibration (OAV), and tension (OAT) of 45° off-axis tests of flat pieces of cardboards were analyzed to determine the in-plane shear modulus (IPSM) using samples of various widths. The analyses were performed with simulations using the finite element method (FEM) for models with and without lamination and physical experiments using cardboard samples. For the FV, TV, and ST tests, the IPSM was calculated using binary search (BS) and linear regression (LR). The FEM results suggest that the IPSM values obtained from the TV and ST test simulations were affected by lamination. In contrast, the effect of lamination was not clear in the FV, OAV, and OAT test simulations. The coefficient of variation obtained from the FV experiments was often larger than that obtained from other tests. Despite this variation, the FV test is more attractive than the other tests because the experiments could be performed easily, and the effect of lamination could be reduced. [ABSTRACT FROM AUTHOR]

The work is devoted to determining the characteristics of turbine stages in off-design modes that arise when pressures and temperatures change before or after the stage, a transition to a different rotation speed, or, for example, when the composition of the working fluid changes. As part of the project, a quasi-one-dimensional method for calculating the characteristics of a turboexpander assembly (TEA) stage when changing operating parameters and/or working fluid has been developed, which differs from known methods by using the equations of the state of real gas, adaptation to purely radial stages, and a simplified approach to determining the pressure at the outlet of the guide vane for assessing the degree of reactivity and the ability to switch to another working fluid, including a mixed one. The analytical methodology was verified by comparison with the experimental data of other authors and the results of calculations using CFD methods for radial-axial stages as well as with approaches to the calculation of purely radial turbomachines due to the lack of experimental data for this type of TEA in the public domain. An extended characteristic of a radial stage operating in air (turbo map) was constructed, and the dependences of the isentropic efficiency, degree of reactivity, mass flow and power of the stage on the relative circumferential speed were assessed. An assessment was made of the impact of switching to another working fluid (for example, switching from air to methane was chosen). It is shown that the characteristics do not change qualitatively but they shift from one another along the axis of the relative peripheral velocity. Further development of the technique involves taking into account possible phase transitions (volume condensation) in the flow part. [ABSTRACT FROM AUTHOR]

Diagrams of the modes of steam turbine units are used in power plants when current technical conditions must be assessed according to the criteria of their thermal efficiency. Moreover, if for condensing turbines such diagrams degenerate into a linear dependence of power on steam flow into the turbine, then for heating steam turbines, they allow determining the power of the steam turbine and the amount of heat from its extraction at various possible ratios. To date, the so-called digitization of regulatory technical documentation data and experimental data obtained as a result of testing has become relevant for the analysis of technological processes in steam turbines. This article presents the automated charting of steam turbine modes using software developed based on the MS Excel software package. Such processing results in so-called user functions that significantly speed up data processing, perform calculations when constructing nomograms, and facilitate the search for technical solutions to optimize the technology of operation and determine reserves of thermal efficiency. In addition, such a technique can be used to analyze the efficiency of steam turbine installations when they operate in various modes using calculation schemes, which reduces the number of tests and thereby reduces the complexity of surveys without losing the accuracy of the results. The results can be used as input data for the predictive analysis of the occurrence and development of damage in equipment parts, as well as for the development of recommendations to improve their efficiency. [ABSTRACT FROM AUTHOR]

Introduction. The article discusses the current state of the possibilities to improve the efficiency of construction processes by using fibre-reinforced concrete in the construction of transport and utility tunnels, as well as other critical building structures. The authors present foreign experience with widespread use of fibre-reinforced concrete in transport construction, as well as few such cases for domestic practice. The inconsistency of domestic experience with the modern state of art has been noted. The main blockers in the development of the issue are under consideration, the theoretical approach and practical application are presented. Materials and methods. The principal aspects of the current approach to the quality indicators of fibre-reinforced concrete and the classification principles of fibre-reinforced concrete based on quality criteria, which are the basis for the normalization of material characteristics, are described. The continuity of domestic and European regulatory documents is shown. Results. Illustrated examples of the possibilities of an optimization approach to the selection of structural solutions in the design of transport construction facilities used in international practice are described. Conclusion. The argumentation in favor of technology development is shown. This opens up possibilities for significant cost reduction justified by a scientific approach. In conclusion, the authors provide recommendations on the general application of the promising material in the domestic practice

Accurate calculation of power losses has always been important for the design and optimization of magnetic components consisting of windings and magnetic cores, such as inductors and transformers. Focusing on windings, litz wire outperforms its counterparts in terms of eddy current losses, making it particularly suitable for high-frequency (HF) applications. The power loss calculation of litz wire is however challenging due to its complex structure of thin strands twisted in multiple levels. This article therefore aims to review various kinds of litz wire power loss calculation methods from analytical methods, numerical methods to coupling ones. In addition to, the principles and applications of each method, their inherent correlation and differences are also highlighted in this article. On this basis, a comprehensive review and comparison of different calculation methods of litz-wire power loss are provided. Finally, future challenges and directions are then summarized, whose ultimate goal is to calculate the power loss of litz wire accurately and efficiently. [ABSTRACT FROM AUTHOR]

This article outlines the concept of a tool for the implementation of socio-economic policy and considers the assessment of social infrastructure provision of the population as one of them, namely a systemic feedback tool. The paper discusses the importance of social infrastructure for the socio-economic development of the province and the methods of assessing the provision of the population with it, identifies the main stages of this procedure and its relationship with other key tools, which is presented in the form of a graphical scheme; discusses the main tasks and features of rationing of indicators as a procedure for developing a reference measure of assessment; discusses and systematizes the main approaches to the calculation of socio-infrastructural provision. At the same time, not infrastructure objects, but more fractional units — elements — are taken as calculation units. It is proposed to systematize various calculation methods in the form of a matrix depending on the arguments used.

Introduction. Active introduction of modular buildings into the practice of modern construction causes the necessity to develop methods of their calculation. At the same time, there are no specialized guidelines for the design of modular buildings. It is impossible to manage only with numerical methods of calculation for forming design recommendations. Therefore, the creation of an analytical method of calculation of modular buildings is an important area of research. The question of determination of forces in elements of modular buildings with bearing columns and rigid intramodular connections is considered.Materials and methods. The determination of forces in the elements of modular buildings from vertical loads can be carried out with high accuracy using well-known formulas of building mechanics. The main difficulty is the determination of dynamic effects (wind pulsation and seismic load). It is proposed to use a cantilever construction scheme with the decomposition of masses at the floor level. As a result of calculations, a set of inertial forces is formed from pulsation and seismic action. Modular programme was written to simplify the calculations. The programme is convenient for making preliminary and variant calculations and research of modular building structures.Results. The presented analytical method for determining the forces in the elements of modular buildings shows good convergence of the results with the finite element method. On a concrete example, it is shown that there is practically no discrepancy in determination of forces from vertical loads. The discrepancy from the combined effect of the static and pulsation components is 4.2–16.6 % for bending moments and 1.3–6 % for longitudinal forces. The discrepancy in determining the forces from the seismic load is within the range of 5–10 % for both bending moments and longitudinal forces.Conclusions. The method is convenient for application at the stage of qualitative assessment of design solutions, variant calculations and search for rational design solutions of modular buildings.

177Lu is a radioisotope that has become increasingly popular as a therapeutic agent for treating various conditions, including neuroendocrine tumors and metastatic prostate cancer. 177Lu-tagged radioligands are molecules precisely designed to target and bind to specific receptors or proteins characteristic of targeted cancer. This review paper will present an overview of the available 177Lu-labelled radioligands currently used to treat patients. Based on recurring, active, and completed clinical trials and other available literature, we evaluate current status, interests, and developments in assessing patient-specific dosimetry, which will define the future of this particular treatment modality. In addition, we will discuss the challenges and opportunities of the existing dosimetry standards to measure and calculate the radiation dose delivered to patients, which is essential for ensuring treatments' safety and efficacy. Finally, this article intends to provide an overview of the current state of 177Lu-tagged radioligand therapy and highlight the areas where further research can improve patient treatment outcomes. [ABSTRACT FROM AUTHOR]

Considering the importance of calculating surface deformation based on monitoring data, this paper proposes a method for calculating horizontal deformation based on horizontal displacement monitoring data. This study first analyzes the characteristics of horizontal displacement monitoring data, then proposes a scheme for obtaining the surface horizontal displacement field through corresponding discrete point interpolation. Subsequently, the calculation method for surface horizontal strain is introduced, along with relevant examples. The study also systematically summarizes the calculation methods for surface curvature and surface tilt deformation values, forming a set of surface deformation calculation methods based on monitoring data. The research results indicate that when there is a large number of on-site monitoring points, effective monitoring points can be selected based on the direction of horizontal displacement. When interpolating the surface horizontal displacement field, the interpolation accuracy of the radial basis function method is slightly higher than that of ordinary Kriging. The form of coordinate expression has a significant impact on interpolation accuracy. The accuracy of interpolation using horizontal displacement vectors expressed in polar coordinates is higher than that using vectors expressed in Cartesian coordinates. The calculated surface horizontal strain has effective upper and lower limits, with lower-limit strain on the contour line conforming to the typical surface deformation patterns around mined-out areas. [ABSTRACT FROM AUTHOR]

In order to adjust the electric power network to today's trends—such as the charging of electric vehicles, design of the Internal Electricity Market (IEM), headway of renewable energy sources, etc.—the demand for flexible network solutions is increasingly significant. Dynamic line rating (DLR) technology offers a flexible solution for the uprating of overhead lines. Moreover, the DLR methodology can be used in a wider system approach in order to establish a line management system, including functions such as ice prevention subsystems or the real-time tracking of clearances. Therefore, the extension possibilities and operational features of DLR-based systems have been extensively researched in the last few years, which is also confirmed by the high number of pilot projects funded for research and development on the topic of DLR. The key question during the implementation of a DLR system is the obtainable operational safety of such a system. This mainly depends on the installation places of the field equipment and the accuracy of the line rating calculation models. The aim of this article is the comparison of the so far available international line rating calculation models and also to propose another way for the determination of the real-time line rating. Moreover, laboratory measurements and case studies are presented for the confirmation of the proposed model's reliability. [ABSTRACT FROM AUTHOR]

Background: The Lower Quarter Y-Balance test (YBT-LQ) is a widely used tool in the field of sports medicine and rehabilitation. Interestingly, there are inconsistencies in the literature regarding the methodology for calculating YBT-LQ outcomes. Objective: The aim of this study is to examine whether calculating YBT-LQ outcomes based on maximal reach distance significantly differs from calculations based on mean reach distance. Material and methods: This cross-sectional study involved 100 healthy participants between the age of 18 and 25 years. The participants performed the YBT-LQ. Normalised reach (%) was calculated by dividing both the maximal and mean reach distances (cm) by the length of the lower limb (cm) and then multiplying the result by 100%. The composite score (%) was calculated by summing the maximal and mean reach distances in each direction, and then dividing the obtained values by three times the length of the lower limb, and finally multiplying the result by 100%. Results: The calculation method based on the maximal reach distance, as compared to the mean reach distances, yields significantly (p-value<0.001) higher values for all absolute (cm) and normalised (%) reaches, as well as composite score (%) in the YBT-LQ test. Conclusion: When comparing research findings using two calculation methods for YBT-LQ performance, it is important to consider that the maximal reach distance method yields higher values of 1.7-2.5 cm and 1.8-2.8% (respectively) for absolute and normalised outcomes. These variations highlight the importance of selecting an appropriate calculation method based on the specific objectives of the study and available resources. [ABSTRACT FROM AUTHOR]

Copyright of Materiały Budowlane is the property of Wydawnictwo SIGMA-NOT and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Beijing University of Civil Engineering & Architecture is the property of Journal of Beijing University of Civil Engineering & Architecture Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

How safe are our structures? – Conceptual paper of the DGGT Working Group 2.15 "Reliability‐Based Methods in Geotechnical Engineering" The future Eurocode 7 will explicitly allow the use of reliability‐based methods in geotechnical planning and design. In Germany, there is hardly any experience in the practical application of such methods so far and thus the reservations towards these methods are plenty. The new DGGT Working Group (WG) 2.15 "Reliability‐Based Methods in Geotechnical Engineering" has set itself the goal of providing a practical access to those methods by means of practice‐oriented instructions and recommendations as well as accompanying training and further education courses. The aim is to clarify the possibilities and limitations and, above all, to exploit their potential. This article presents the general principles as well as the future fields of work of the WG 2.15. Starting with the introduction of relevant technical terms, the implementation of reliability‐based methods within the current codes of practice and regulations is shown. Using the life cycle of a geotechnical structure, the uncertainties in geotechnical designs and assessments are described. Subsequently it is outlined, in which situations and to what extend reliability‐based methods can aid engineers, clients and inspectors in verification and decision‐making processes. In the future, WG 2.15 will develop recommendations on individual topics and publish them successively. [ABSTRACT FROM AUTHOR]

Hydraulic heave in round excavation pits with relief boreholes – calculation approach The use of relief boreholes to reduce the effect of a vertical upward flow has proven to be a constructive measure to avoid the risk of hydraulic heave in excavation pits in groundwater. The applicable standards and regulations, however, only provide general information on the use of relief boreholes. A concept for the verification against hydraulic heave failure using relief boreholes is missing as well as defined information on the arrangement of the relief boreholes and the influence of the excavation geometry. Therefore, the aim of the research work at the Chair of Geotechnical Engineering of RWTH Aachen University was to develop a concept for the proof against hydraulic heave failure with the arrangement of relief boreholes. The result was a calculation approach that determines the decisive fracture body under consideration of the flow conditions due to the relief boreholes. This fracture body can then be used for the proof against hydraulic heave failure. Based on this, dimensioning diagrams were finally generated for typical excavation pit geometries in dimensionless representation. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The relevance of the study lies in the problem of calculating the bearing capacity of pile-screw foundations in the conditions of cryolithozone propagation under the influence of static pulling and pressing loads. Pile-screw foundations are a fairly new type in construction, although the first mention of them dates back to the late XVIII – early XIX centuries. This technology has proven itself from the best side. In recent years, screw piles have gained wide popularity in the construction of various facilities, but still occupy a relatively small share in foundation construction. The potential of this technology is poorly disclosed, the definition of load-bearing capacity in domestic standards is not regulated. Objective to analyze the existing methods and develop recommendations for calculating the bearing capacity of pile-screw foundations in cryolithozone conditions, comparing the results of calculations of the ultimate resistances of this type of foundation obtained by various methods with full-scale field tests and drilling piles. Methods: systematization, analysis of domestic and foreign experience in calculating screw piles in the areas of permafrost distribution; collection and processing of materials for field testing of soils with screw piles in the area of arrangement of the Bovanenkovskoe field; performing calculations of bearing capacity by various methods and comparing the results with data from field tests and drilling piles; description of the methodology for conducting field tests of piles in the conditions of the cryolithozone. Results. The authors have carried out the calculations of the bearing capacity of screw piles under cryolithozone conditions by various methods described in the literature and their comparison with the data of field tests of soils, a comparative assessment of the bearing capacity of screw piles with metal drill piles with a tip in the same geocryological conditions, revealed the advantages and disadvantages of the methods considered and various types of pile foundations. Based on the results obtained, conclusions are drawn about the possibility of using screw piles in cryolithozones and obtaining the necessary and sufficient information for their design.

Considering the importance of calculating surface deformation based on monitoring data, this paper proposes a method for calculating horizontal deformation based on horizontal displacement monitoring data. This study first analyzes the characteristics of horizontal displacement monitoring data, then proposes a scheme for obtaining the surface horizontal displacement field through corresponding discrete point interpolation. Subsequently, the calculation method for surface horizontal strain is introduced, along with relevant examples. The study also systematically summarizes the calculation methods for surface curvature and surface tilt deformation values, forming a set of surface deformation calculation methods based on monitoring data. The research results indicate that when there is a large number of on-site monitoring points, effective monitoring points can be selected based on the direction of horizontal displacement. When interpolating the surface horizontal displacement field, the interpolation accuracy of the radial basis function method is slightly higher than that of ordinary Kriging. The form of coordinate expression has a significant impact on interpolation accuracy. The accuracy of interpolation using horizontal displacement vectors expressed in polar coordinates is higher than that using vectors expressed in Cartesian coordinates. The calculated surface horizontal strain has effective upper and lower limits, with lower-limit strain on the contour line conforming to the typical surface deformation patterns around mined-out areas.

【Objective】 Reference evapotranspiration (ET0) measures the potential water loss from soils in terrestrial systems. It varies with a multitude of factors and can be calculated by different methods. In this paper, we compared ET0 calculated by five methods for regions with incomplete meteorological data across Gansu province in northwestern China. 【Method】 We divided the province into four regions: arid area in Hexi (Region I), semi-arid area in northern Longzhong (Region II), semi-humid area in southern Longzhong (Region III), and humid area in Longnan and Gannan (Region IV). The reference evapotranspiration in each region was calculated using the Hargreaves-Samani (Har), the FAO-24 Penman (24PM), the FAO 1948 Penman (48PM), the Makkink (Mak), and the Priestley Taylor (PT) methods, respectively. For each method, we calculated the daily ET0 based on data measured from 1980 to 2019 from 26 meteorological stations across the province. The accuracy and robustness of each method for each region was tested against that estimated using the FAO-56 penman Monteith (P-M) method. 【Result】 ET0 calculated from different methods varied, though the variation depended on region. The results calculated from the Har and Mak methods were correlated with that from the P-M method with the correlation coefficients close to unity, despite that the Har method was less accurate for high altitude regions. The results estimated by the 48PM and 24PM methods were both greater than the ET0 calculated by P-M method. The accuracy of the five simplified methods for estimating ET0 was ranked in the order of Mak > Har >48PM > 24PM > PT for Region I, and Har >Mak> 48PM > 24PM >PT for other three regions. 【Conclusion】 For regions that are lack of meteorological data, the Mak method was the best alternative for estimating ET0 in Region I, while the Har method worked better for other regions in Gansu province.

New definition and measurement of the boundary layer thickness on a wall – Determination of thermodynamic and aerodynamic quantities This publication describes the theoretical basis and a measuring device to measure the convective heat transfer coefficient and the shear stress on a wall exposed to the flow. For this purpose, the Convective Heat Transfer Meter (CHM) measures the temperature gradient within the flow boundary layer. For exponential time processes, the time constant τ is defined as the period of time after which a quantity A(t) has declined to a fraction of 1/e of the initial value, with the Eulerian number being 2.718... Analogous to this, the boundary layer thickness d is proposed for spatial processes with exponential approximation instead of the time constant τ. Such a process occurs in the viscous boundary layer area of a wall exposed to flow. The flow velocity U(y) running parallel to the wall surface is decelerated due to the viscosity of the air and the friction of the wall surface until it reaches the condition of adhesion to the wall surface. The newly defined boundary layer thickness d is the distance from the wall y = d for which the local flow velocity U(y=d) has reached the fraction of (1–e–1) from the macroscopic flow velocity U(y=∞). In contrast to the frequently used boundary layer thickness δ, for which the threshold is by definition 99 % of U(y=∞), the new definition of the boundary layer thickness d offers advantages in terms of its measurability and the determination of the convective heat transfer and the determination of the shear stress on bodies in contact with the flow. [ABSTRACT FROM AUTHOR]

Validation of the AVISA model Despite advanced design technologies, construction on cohesive soils is still a challenge. Especially when dealing with cyclic loading conditions combined with the time‐dependent behavior of cohesive soils, such as offshore structures or even dams, the tools to predict the long‐term deformations of fine‐grained soil are limited. Due to the complex influence of loading rate, preloading, and soil structure, it is necessary to understand the effects of these influences on cohesive materials through laboratory testing and describe them numerically through accurate and physically based constitutive equations. Researchers (continue to) develop many hundreds of material models each year. Most of them are used for PhDs and not investigated further. In this work, such a model, developed in the first author's PhD, is be validated. The performance of the AVISA model has been previously demonstrated on experiments of various fine‐grained soils. In this paper, a new experimental study on Malaysia Kaolin is used for the validation of the model. Furthermore, the reproducibility of the so‐called Krey and Tiedemann criteria, parameters φ′s , c′ und φ′ is investigated by simulations of simple shear tests. It should be noted that many constitutive models for fine‐grained soils fail in this task. [ABSTRACT FROM AUTHOR]

Steel tube struts in braced excavations – Simplified design for cross section class 4 Steel tubes are often used as excavation struts. When designing long struts without intermediate supports, tubes with large diameter and small wall thickness are particularly economical. This may lead to reaching the limit of cross section class 4 requiring a shell buckling analysis according to EN 1993‐1‐6. In this article a simplified design method using section‐related buckling stresses based on EN 1993‐1‐6 Annex D is described. Ready‐to‐use section‐related buckling stresses are given for commonly used steel tubes of cross section class 4. [ABSTRACT FROM AUTHOR]

The role of fractional calculus in circuit systems has received increased attention in recent years. In order to evaluate the effectiveness of time-domain calculation methods in the analysis of fractional-order piecewise smooth circuit systems, an experimental prototype is developed, and the effects of three typical calculation methods in different test scenarios are compared and studied in this paper. It is proved that Oustaloup's rational approximation method usually overestimates the peak-to-peak current and brings in the pulse–voltage phenomenon in piecewise smooth test scenarios, while the results of the two iterative recurrence-form numerical methods are in good agreement with the experimental results. The study results are dedicated to provide a reference for efficiently deploying calculation methods in fractional-order piecewise smooth circuit systems. Some quantitative analysis results are concluded in this paper. [ABSTRACT FROM AUTHOR]

177Lu is a radioisotope that has become increasingly popular as a therapeutic agent for treating various conditions, including neuroendocrine tumors and metastatic prostate cancer. 177Lu-tagged radioligands are molecules precisely designed to target and bind to specific receptors or proteins characteristic of targeted cancer. This review paper will present an overview of the available 177Lu-labelled radioligands currently used to treat patients. Based on recurring, active, and completed clinical trials and other available literature, we evaluate current status, interests, and developments in assessing patient-specific dosimetry, which will define the future of this particular treatment modality. In addition, we will discuss the challenges and opportunities of the existing dosimetry standards to measure and calculate the radiation dose delivered to patients, which is essential for ensuring treatments’ safety and efficacy. Finally, this article intends to provide an overview of the current state of 177Lu- tagged radioligand therapy and highlight the areas where further research can improve patient treatment outcomes.

In order to adjust the electric power network to today’s trends—such as the charging of electric vehicles, design of the Internal Electricity Market (IEM), headway of renewable energy sources, etc.—the demand for flexible network solutions is increasingly significant. Dynamic line rating (DLR) technology offers a flexible solution for the uprating of overhead lines. Moreover, the DLR methodology can be used in a wider system approach in order to establish a line management system, including functions such as ice prevention subsystems or the real-time tracking of clearances. Therefore, the extension possibilities and operational features of DLR-based systems have been extensively researched in the last few years, which is also confirmed by the high number of pilot projects funded for research and development on the topic of DLR. The key question during the implementation of a DLR system is the obtainable operational safety of such a system. This mainly depends on the installation places of the field equipment and the accuracy of the line rating calculation models. The aim of this article is the comparison of the so far available international line rating calculation models and also to propose another way for the determination of the real-time line rating. Moreover, laboratory measurements and case studies are presented for the confirmation of the proposed model’s reliability.

Green hydrogen via renewable powered electrolysis has a high relevance in decarbonization and supply security. Achieving economically competitive hydrogen production costs is a major challenge in times of an energy price crisis. Our objective is to show the economically optimal installed capacity of electrolysers in relation to wind and solar power so swift and credible statements can be made regarding the system design. The ratio between renewable generation and electrolysis power as well as scaling effects, operating behaviour and development of costs are considered. Hydrogen production costs are calculated for four exemplary real PV and wind sites and different ratios of electrolysis to renewable power for the year 2020. The ideal ratio for PV systems is between 14% and 73% and for wind between 3.3% and 143% for low and high full load hours. The lowest hydrogen production costs are identified at 2.53 €/kg for 50 MW wind power and 72 MW electrolysis power. The results provide plant constructors the possibility to create a cost-optimized design via an optimum ratio of electrolysis to renewable capacity. Therefore, the procedures for planning and dimensioning of selected systems can be drastically simplified. [Display omitted] • Calculation method for cost-optimized renewables to electrolysis ratio. • Lowest LCOH at 2.53 €/kg for 50 MW wind power and 72 MW electrolysis power. • Cost-optimized ratio of electrolysis to RES between 13.6% and 73% for PV. • Cost-optimized ratio of electrolysis to RES between 3.3% and 143% for wind. [ABSTRACT FROM AUTHOR]

Summary: Concrete‐filled stainless steel tube (CFSST) members combine the advantages of stainless steel materials and concrete‐filled steel tube (CFST) members. Therefore, it has a broad range of applications than CFST members in the marine environment and other scenarios requiring great durability and corrosion resistance. However, there are limited researches on the large‐sized CFSST members. In this paper, 30 circular CFSST members with varying steel ratios (3.7% ≤ α ≤ 10.3%), diameters (500 mm ≤ D ≤ 900 mm), and strength of concrete (fcu = 40 MPa, 50 MPa) are studied on the size effect under axial compression. For peak axial stress, peak axial strain, and composite elastic modulus, size effects are investigated. According to the results, the peak axial stress and peak axial strain of the members increase with the increase in diameter. The modulus of composite elasticity essentially stays constant as the diameter increases, showing that there is no obvious size effect on the composite elastic modulus. The size effect of peak axial stress and peak axial strain is influenced by the steel ratio. Increasing the steel ratio tended to decrease the size effect. According to the generated data, it was found that the current codes of Chinese and European underestimate the ultimate bearing capacity of CFSST short columns significantly. To this end, the resistances of the large‐sized austenitic CFSST columns with a low steel ratio are well predicted by the proposed design model after being modified, based on GB 50936‐2014 and EN 1994‐1‐1 design codes. [ABSTRACT FROM AUTHOR]

In molten salt reactors (MSRs) with circulating liquid fuel, delayed neutron precursors can escape from the active core and be distributed over the entire reactor circuit. Taking into account the decrease in the effective fraction of delayed neutrons due to the motion of the emitters is important for further analysis of the reactor kinetics. A new approach is proposed to account for fuel circulation in the fuel circuit on the basis of a combined calculation by the Monte Carlo and finite volume methods. The calculation was implemented using the interface between the codes SERPENT and OpenFOAM software applications (SAs) in the form of the OFSI software. Calculations of the effective delayed neutron fraction for the 10-MWt heat power MSR reactor circuit with a cavity type cylindrical core and the Li, Be, Pu/F fuel salt mixture are performed. On the basis of the results obtained, conclusions are made about the applicability of the technique and ways of its further development are outlined. [ABSTRACT FROM AUTHOR]

Failure criteria for foam‐grouted gravel under multiaxial loading Foam grouting is an innovative method for improving the mechanical properties of cohesionless, coarse‐grained soils. Despite this, only a few experimental studies have been conducted to assess the failure of foam‐injected soils under multiaxial loading. This paper aims to fill this gap in knowledge. The stiffness and strength of the natural soil, which serve as reference values for the evaluation of the improvement effect due to the injection, are derived from drained triaxial tests. The mechanical behaviour of the foam‐injected soil is investigated using uniaxial, triaxial, and splitting tensile tests. The foam‐injected soil, exhibits significantly higher strength and stiffness but lower ductility than the untreated soil. The ductility of the foam‐injected soil increases with increasing lateral pressure. The splitting tensile strength is only a small fraction of the compressive strength. The adequacy of the failure criteria Mohr‐Coulomb, Hoek‐Brown and Lade for the description of the failure of foam‐injected coarse‐grained soils is verified. All three failure criteria are basically suitable to describe the state of failure in triaxial compression. For compressive and tensile loading, the Hoek‐Brown and Lade failure criteria seem to be more appropriate compared to Mohr‐Coulomb. [ABSTRACT FROM AUTHOR]

Simple and fast dynamic model for the prediction of PV self‐consumption The widespread use of renewable energy plays a crucial role in increasing the energy efficiency of the building stock. The significantly decreased PV system prices and the high flexibility in electricity use for all loads in a building, i.e., space heating (and cooling) and domestic hot water in combination with heat pumps, auxiliary energies, household appliances, and also increasingly electric mobility leads to a wide use of PV. However, the integration of PV into the building is complex and requires the use of electrical and/or thermal energy storage and appropriate control strategies. Therefore, evaluating and optimizing the part of PV electricity that is used directly or stored in the building is a challenging task. Thus, for a detailed analysis of PV and energy storage at the building level, extensive building and system simulations were performed using reference buildings. [ABSTRACT FROM AUTHOR]

The room‐side heat transfer of a building is essential for calculating and simulating heat loss through radiation and convection in interior spaces, and also for preventing mould growth and condensation. By means of Computational Fluid Dynamics (CFD) simulations, this study investigates the effect of floor heating, mixing ventilation, furniture, room geometry, and their combinations on the interior heat transfer coefficient (HTC) of a typical office room. The results show an inhomogeneous distribution of the HTC on the exterior walls. HTC values are generally below the German standardised value for thermal protection, which means an overestimation of the heat loss when the standardised value is applied. However, compared to the standardised value for preventing mould growth, the minimum surface‐averaged HTC behind closets is 63 % lower, potentially leading to mould growth and condensation. [ABSTRACT FROM AUTHOR]

Building Performance Simulation at RWTH Aachen University – Series: Building simulation and calculation tools in teaching This series of articles presents the use of computer programs in university teaching of building physics and building technology for architects and civil engineers. Since 2013, the subject "Building Performance Simulation" has been offered at RWTH Aachen University at the Institute of Energy Efficiency and Sustainable Building E3D. The target group is the core courses "Civil Engineering", "Environmental Engineering" and Business Administration and Engineering: Civil Engineering in the Master's program at the Faculty of Civil Engineering. The aim of the current course is to teach the students the theoretical and practical basics of building performance simulation. For this purpose, the theoretical basics are prepared in a modular way and presented in detail in the lecture. In the exercise, the basics of programming are taught or refreshed. Subsequently, modular subcomponents for a simulation are implemented in the Modelica language. This enables the students to progress through the complex collection of topics in an appropriate manner and to deal in depth with topics that would certainly be neglected in a purely application‐oriented view of an existing building simulation program. [ABSTRACT FROM AUTHOR]

The article demonstrates the possibilities of corporate governance methods and investment decision-making models for the cultural organizations and events (on the examples of federal theaters). Financial and investment analysis was applied in the study. The article discusses the hypothesis of the possibility of balancing budgets for new theatrical productions, taking the rehearsal period, premiere and running as a whole. The productions are not considered as deadweight losses, but are analysed as assets with risky returns. The results of the financial analysis of the staging activities of the leading theaters demonstrate their limited possibilities in balancing the budgets for new productions. The most popular performance (with an average ticket price above the market and a stable occupancy rate of over 90 %) requires at least 5–6 years of active running to recoup the initial investment. The author’s are expected to help the performing arts organizations to identify and assess losses during the pandemic crisis. The scientific novelty is to the approach to calculating and forecasting the return on production costs.

The direct-costing method is a method often used for determining and analyzing costs, in order to make the best decisions at the management level, both for companies whose object of activity is production and for those providing services, such as accommodation units that are the subject of this paper. Romania enjoys a wide category of tourist reception structures, having a huge tourist potential, given the extremely varied relief and the multitude of tourist attractions in the country, representing an important source of the labour market (at the beginning of 2020, about 400,000 employment contracts were registered in the industry), but nevertheless they hold only about 3% of the gross domestic product of Romania (unlike Greece, where they hold 25%). All this leads to the importance of the fact that in the hotel industry, the management is informed with regard to the cost situation, in order to increase the efficiency and effectiveness of the activity, which is the main step towards the development of the hotel sector in Romania.

The theoretical foundations of compatible finite elements construction for static and dynamic analysis of single-layer and multilayer shells are discussed. These finite elements are implemented in the PRINS computer program. The paper presents verification tests to investigate the accuracy and convergence of the results of calculating various shells using these finite elements. Shell structures are widely used in various fields of technology - construction, mechanical engineering, aircraft construction, shipbuilding, etc. Specialists on the design and calculation of such structures need a reliable and accessible tool for the practical problems solving. Computer program PRINS can be one of such tools. It can be effectively used by engineers of design and scientific organizations to solve a wide class of engineering problems related to the calculations of shell structures. The paper describes the finite elements of the shells, implemented in the PRINS program. The results of verification calculations are presented, which confirm the high accuracy of this program.

Development of a model to evaluate the environmental properties of common outdoor plasters and mortars A requirement of the Construction Products Regulation (CPR) in the European Union states that construction materials and works must be designed in a way that throughout their entire life cycle, they have no exceedingly high negative impact on the environment. The objective of the current work was to develop a model capable to evaluate the environmental properties of outdoor plasters and mortars. Therefore, the extensive database recollected during 10 years of field and laboratory experiments by Fraunhofer IBP for these products was used as a basis and for validation, respectively. A three‐stage model was set up. In "Level 1", runoff volumes are calculated for a specific façade. In "Level 2", leached inorganic substances and their concentrations in runoff water are identified. As a final step, the evaluation of the environmental risk of stormwater runoff from façades covered with plasters and mortars takes place in "Level 3" using a groundwater risk assessment including leachate prognosis. It could be shown that vanadium, chromium and lead can be leached from mineral plasters and mortars during rain events in relevant concentrations. However, the evaluation showed that within usual application scenarios threshold values at a defined point of compliance are not expected to be exceeded. [ABSTRACT FROM AUTHOR]

To study the reasonable values of fatigue damage factors of railway steel bridges under double lanes loading, the formulas of double-lane fatigue factors are deduced based on the principle of fatigue damage equivalence. The differences in calculation methods and values between Chinese, European and Japanese codes are analyzed, and their causes are disclosed. The research reveals that the deduced formulas clarify the theoretical basis of double-lane fatigue factors in the design codes. The values of these factors are closely related to the slope of the S-N curves and simultaneously loading probability of two lanes, which are valued differently and cause the differences of double-lane fatigue factors in Chinese, European and Japanese codes. The employed factors in Chinese codes are more conservative than those in Japanese and European codes for that larger simultaneously loading probability is adopted. For the maximum difference cases, the values of the factors in Chinese design codes are 1.04 times of those in European codes and 1.30 times of those in Japanese codes. According to the operation of China's railway, the simultaneously loading probability is analyzed, and the results show that the probability value of 20% employed in Chinese codes is too conservative for most bridges with a span less than 1000 m. [ABSTRACT FROM AUTHOR]

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Harmonization in Geotechnics – a statistical method to determine representative values for ground properties considering prior knowledge In the revised version of Eurocode 7 (prEN 1997‐1:2021‐11), the value for the geotechnical parameter to be applied in the design will in future be referred to as the representative value, which can be derived from the characteristic or nominal value. While the nominal value is determined using conventional estimation methods, the characteristic value is determined using statistical methods. For this purpose, an applicable statistical method is recommended in prEN1997‐1:2021‐11. In this article, a statistical method is explained that fulfils all requirements according to prEN 1997‐1:2021‐11 and also allows the possibility of taking into account prior information. Compared to the statistical method in prEN 1997‐1:2021‐11, the new method is to be considered more robust, as shown in application examples. [ABSTRACT FROM AUTHOR]

For the numerical calculation of the stability of structures in soil The use of the finite element method (FEM) for the design and recalculation of geotechnical structures is steadily increasing. For both slopes and retaining walls, the advantages of the FEM are already used for accurate determination of the deformations and stresses of structures in the serviceability limit state (SLS). The application in the ultimate limit state (ULS) is currently still a research topic for structures with soil‐structure interaction, such as retaining walls. An extended strength reduction, where component strength is reduced in addition to the shear parameters of the soil, is intended to account for the influence of the structure in ULS‐simulations. In addition to the component strength, other parameters, such as the external load‐bearing capacity of anchors or the contact friction between soil and component, play a role for determination of the governing failure mechanism. Using a Python script, the strength reduction approach implemented in PLAXIS 2D is re‐implemented and verified exemplarily on a braced excavation pit and a tie‐back quay wall. By extending the own strength reduction implementation with additional parameters, which are relevant for the stability of geotechnical structures, their influence on the stability calculation and the resulting failure mechanisms is investigated. [ABSTRACT FROM AUTHOR]

On the application of earth resistance models of p‐y curves and DIN 4085 for the design of laterally loaded piles in layered soils The design of laterally loaded piles in Germany is based on a simplified subgrade reaction modulus or the method by Blum. With these methods the lateral pile deflection cannot be calculated very accurately. Internationally the so‐called p‐y approach is widely used, which is based on nonlinear spring stiffnesses to define the subgrade reaction modulus. In this paper the p‐y approach is described in detail and the application of each calculation model is discussed. For the consideration of the effect from multi‐layered soils the approach by Georgiadis is used. The earth resistance determined by this procedure is then compared with the spatial earth resistance from DIN 4085. Because DIN 4085 just offers equations for homogenous soils, the relevant equations are extended for layered soils. In a parameter study on typical soil conditions the decisive differences of the individual approaches are shown and discussed. [ABSTRACT FROM AUTHOR]