The movement towards low-emission and sustainable building practices has driven increased use of natural, carbon-based materials such as wood. While these materials offer significant environmental advantages, their inherent flammability introduces new challenges for timber building safety. Despite advancements in fire protection standards and building regulations, the risk of fire incidents—whether from technical failure, human error, or intentional acts—remains. The rapid detection of fire onset is crucial for safeguarding human life, animal welfare, and valuable assets. This study investigates the potential of monitoring fire precursor gases emitted inside building structures during pre-ignition and early combustion stages. The research also examines the sensitivity and effectiveness of commercial smoke detectors compared with custom sensor arrays in detecting these emissions. A representative structural sample was constructed and subjected to a controlled fire scenario in a laboratory setting, providing insights into the integration of gas sensing technologies for enhanced fire resilience in sustainable building systems.

Several structural health monitoring projects have recently emerged to document the hygrothermal behaviour of mass timber buildings during both construction and service.Understanding moisture conditions on site can significantly impact the construction efficiency of mass timber structures.It is also essential to comprehend the effectiveness of moisture control strategies and construction practices in different climates to streamline project delivery and prevent long-term durability issues.This paper describes the first period of hygrothermal monitoring of three mass timber buildings in three different climate zones, outlining potential approaches for enhancing and integrating data, which can leverage the increasing availability of data from various monitoring projects.

Social workers require a better understanding of the impact of pandemic measures on the level of physical activity of their clients to better target client activation. In this retrospective tracker-based study (two years of measurement), we examined changes in the physical activity of the elderly population (204 participants with an average age of 84.5 years) in the Czech Republic as a result of measures to prevent the spread of COVID-19. Physical activity was statistically compared according to the physical, demographic and social conditions of the participants. In addition to observing the expected activity decrease during the COVID-19 pandemic, we made several hypotheses based on the sex, age group, body mass index, type of housing (apartment or house) and size of the city of residence. We found that 33% of the 204 participants had increased levels of physical activity in the period following the COVID-19 pandemic outbreak in Central Europe. We found that the size of the city where the seniors lived and the type of housing did not affect the general level of physical activity. When comparing physical acquisition rates in each month of 2019 and 2020, we saw the largest declines in April and May 2020, that is, one month after the start of the lockdown.

Mass timber construction systems, incorporating engineered wood products as structural elements, are gaining acceptance as a sustainable alternative to multi-story concrete or steel-frame structures. The relative novelty of these systems brings uncertainties on whether these buildings perform long-term as expected. Consequently, several structural health monitoring (SHM) projects have recently emerged to document their behavior. A wide and systematic use of this data by the mass timber industry is currently hindered by limitations of SHM programs. These limitations include scalability, difficulty of data integration, diverse strategies for data collection, scarcity of relevant data, complexity of data analysis, and limited usability of predictive tools. This perspective paper envisions the use of avatars as a Web-based layer on top of sensing devices to support SHM data and protocol interoperability, analysis, and reasoning capability and to improve life cycle management of mass timber buildings. The proposed approach supports robustness, high level and large-scale interoperability and data processing by leveraging the Web protocol stack, overcoming many limitations of conventional centralized SHM systems. The design of avatars is applied in an exemplary scenario of hygrothermal data reconstruction, and use of this data to compare different mold growth prediction models. The proposed approach demonstrates the ability of avatars to efficiently filter and enrich data from heterogeneous sensors, thus overcoming problems due to data gaps or insufficient spatial distribution of sensors. In addition, the designed avatars can provide prediction or reasoning capability about the building, thus acting as a digital twin solution to support building lifecycle management.

Condition of road bridges in central as well as eastern Europe is not excellent. Lack of funding for maintenance requires precise identification of road bridge in need of investment. Integration of permanent monitoring sensors during construction of new bridge is a tool for integrated diagnostics. While the integrated Fiber Bragg Grating (FBG) sensors can be used for strain measurement or crack detection, in meantime they could be the same sensors used for traffic load estimation. Two types of FBG sensors were installed in concrete road bridge during construction phase in 2017 Czech Republic. Two FBG sensors in steel body and 4 Glass Fiber Reinforced Polymer GFRP sensor chain was integrated in the concrete body of the pre-stressed reinforced concrete element. Sensors are measuring strain in longitudinal direction of the bridge close to the bottom edge of the bridge where load on the bridge is causing extension. The signal from FBG sensors is processed by interrogation unit FBGuard and since they are embedded in the concrete, they are well protected against vandalism as well as against outdoor weather conditions. Weight in Motion (WIM) system together with measurement of acceleration was installed on the same bridge element as a reference system for accurate identification of vehicle type, speed, axle load measurement and bridge deflection under vehicles passed over the bridge element. Methods of fiber optic sensor (FOS) signal processing, mathematical processing to determine important traffic parameters, FOS system accuracy and reliability will be presented in this paper. Limitations of the system will be also discussed in the paper. Installed FOS system is used to determine vehicle number, speed, and weight estimation. Results of signal processing and calculation of traffic parameters from FOS system will be shown on real data obtained from the bridge load tests carried out in 2021.

Long-term structural health monitoring (SHM) plays an important role in the safety of public transport infrastructure such as bridges or tunnels and warns in the event of any emerging problem. This article describes development and testing of system based on fiber Bragg grating (FBG) sensors that can detect changes in strain and temperature. The first phase of the research has been focused on the development of new fiber optic sensors for the monitoring of concrete structures and their investigation in laboratory conditions. The work also shows novel applicability of the same FBG technology for glulam structures. Mechanical loading tests of the concrete beam as well as glulam beam with embedded sensors were carried out. Data measured by developed fiber optic sensors were compared with the readings from reference sensors as well as with the analytically calculated values. The achieved results proved good agreement between the measured data, analytical data and reference methods. In second phase of the research, the pilot installation of the sensors was carried out on the newly constructed prestressed-concrete bridge. The bridge was monitored throughout pre-stressing phase and monitoring continued after the completion of the construction works. Problems with the fragility of the sensors occurred during the measurements, but the obtained results provide a good basis for further improvement of the system.

Abstract The paper focuses on the design, implementation and measurement of parameters of an air handling unit (AHU) with the Peltier cells. This is a small local modular AHU for fresh air flows of 50 to 200 m3/hr. The unit is designed for ventilation of residential and administrative buildings. Computer simulations were utilized designing the unit (including CFD), and many measurements were performed. The design of the AHU uses the Peltier effect, which transfers the heat from the exhaust air drawn from the room to the fresh supply air (heating mode). In reverse, the unit then allows for pre-cooling of the supply air (cooling mode). The air handling unit with the Peltier element does not achieve the high efficiency of the compressor cycle units, but is much simpler and has longer life expectancy.

Historic buildings are often classified as highly energy-intensive buildings with low energy efficiency. Thanks to their overall percentage share in the European real estate market, it is important to focus on these dwellings with an innovative approach and functional, sensitive aesthetic solutions, thus significantly reducing their energy intensity, increasing their energy efficiency and improving the indoor living conditions. At the same time, it will greatly increase the chance to meet the new energy and emission targets currently proposed by the European Commission.

Recently, there has been an increased interest in structural health monitoring (SHM) of building and transport structures. Standard strain gauges placed on a beam surface are mostly used to monitor the mechanical stresses of timber or concrete structures. However, these sensors are susceptible to mechanical damage, electromagnetic interference or negative influences of the measured data during the measurement, such as temperature variations or potential loss of data due to explosive environment. The fibre optic sensor system offers a more suitable and reliable solution – the sensors can be integrated directly into the load bearing structure during its production and thus protected by the construction material against ambient environmental conditions. The first part of this paper presents series of environmental tests of a measuring system based on Fibre Bragg Grating principle performed from 2016 to 2018 in a climate chamber. The chamber can generate defined humidity and/or temperature cycles, which can simulate the behavior of the structure under real environmental conditions. The tested fibre optic sensor system is suitable for load bearing timber (glued laminated timber beams) and concrete structures. In the second part of this paper, mechanical loading tests of glued laminated timber beam with integrated fiber optic sensors performed in 2016, 2017 and 2018 are presented. The article describes the design of test cycles, gives the results of testing, and is concluded with the discussion of given results together with the outline of the future research directions.

This article focuses on simulation accuracy of photovoltaic (PV) systems designed for local energy usage in households. The results of simulations can be misleading when the input data is estimated not correctly or the input data has a low time resolution. Load profile is difficult to estimate due to the changes in user behaviour and possible high power fluctuations. In contrast to many other studies, 15 s data are used as PV power and household load data input. Using this data for simulations we show the influence of averaging interval on the results and thus we indicate the variance in the simulated system performance (rates of self-consumption, energy independence and grid interaction). (C) 2017 Elsevier Ltd. All rights reserved.

As far as the road network is concerned, bridge and tunnel structures are considered to be its most important and complicated elements. Bridges are completely exposed to environmental impacts; therefore, it is necessary to predict the actual structural health. The prediction can be based on monitoring of mechanical stresses which can be used to determine any resulting deterioration of load bearing structure. The main objective of bridge monitoring during construction phase is an observation of a structural behaviour in individual construction stages, particularly the actual mechanical stresses (or deformations) in critical cross sections. Based on the measured data it is possible to verify the designed parameters or to modify the design in following construction stages (load bearing structure dimensions’ adjustment, pre-stressing, loading of the bridge suspensions, etc.). After the construction completion, it is possible to observe the traffic intensity as well as deformations due to temperature changes, in addition to mechanical stress monitoring. This paper presents the initial phase of a field test dealing with the utilization of embedded fibre optic sensors (custom design) for monitoring the bridge structure. The load bearing structure of the bridge is pre-stressed continuous beam structure with three individual spans; this structure is replacing the old stone four-arch bridge, which was already in poor technical condition. The sensors are integrated directly into the load bearing elements; two different types of sensors were embedded into the concrete structure. The paper describes sensor design, installation, monitoring of the pre-stressing process and monitoring of stresses in several weeks after putting the bridge into operation. The two different types of Fibre Bragg Grating sensors were tested in laboratory conditions prior bridge installation. Testing is described and results are evaluated in the paper as well.tone four-arch bridge, which was already in poor technical condition. The sensors are integrated directly into the load bearing elements; two different types of sensors were embedded into the concrete structure. The paper describes sensor construction, installation, monitoring of the pre-stressing process and monitoring of stresses in several weeks after putting the bridge into operation. The two different types of Fibre Bragg Grating sensors were tested in laboratory conditions prior bridge installation. Testing is described and results are evaluated in the paper as well.

This article describes typical services within a building provided by a combination of a battery energy storage system with PV source. Based on the achievements in the photovoltaic and battery research and development sector in the last decade this technology becomes more available and also more affordable. Advanced control algorithms operating the system in defined optimal conditions are described. Lifetime of the system, as well as the battery, is also taken into account. Emphasis is placed on the irradiation prediction which is responsible for accurate PV yield estimation. Operational modes and operational data of an administrative building are presented together with a predictive control based on forecasting and nowcasting service.

Buildings became complex systems where there are various technologies integrated together and thus should work as a single system. Modern building has several monitoring and control systems which should cooperate together to achieve energy saving while keeping indoor comfort and healthy environment. The overall building management systems (BMS) provides an integrated way to gather data from the building and issue control commands to the installed technology. The parameters that are monitored in modern buildings are not only temperature and humidity but todays buildings monitor also concentration values of CO2 or volatile organic compounds (VOC). The experience from last decades shows necessity to monitor also the structure of the building. Renewable materials (wood) are today often used for building construction. This material is quite sensitive to environmental factors like humidity and the environment has to be monitored in order to avoid structural health problems in future. Specially timber when exposed to humidity or moisture can degrade quite quickly and can lose load capacity. Modern communication technologies allows installation of many sensors directly into the structure which allows continuous monitoring of the building construction as well as the indoor climate in the building. Internet of Things (IoT) allows new communication technologies providing low cost, low power sensor application within smartcity sector.

In recent years, a lot of attention has been directed towards the fabricating of smart structures with embedded optical sensors providing in-situ, non-destructive and real time or on-demand information of the construction structural health. This paper describes manufacturing process and performance of a 3D printed sensor prototype. Fibre Bragg grating is used as the sensing element and is embedded during the 3D printing of the sensor structure. Such a structure is able to measure mechanical strain. This functionality is verified by laboratory testing, where the structure is glued onto the surface of a wooden beam specimen which is exposed to load force. The strain of the wooden beam is well known and compared with the measured values given by the embedded optical sensor. (C) 2016 The Authors. Published by Elsevier Ltd.

In this paper, the fiber Bragg gratings are investigated in the context of sensing of deformation inside a sample of a glued laminated timber. For this purpose, a fiber with acrylate recoated Bragg grating is placed and glued between the timber laminates. Since there are still some open questions leading now, one of the goals is to specify, if the sensor that is embedded inside the timber can operate as the sensor that is not. Therefore, the strain of the not embedded sensor is numerically investigated in the first step as the change in the grating period. In order to calculate the Bragg wavelength associated to the grating period, the light propagation through the fiber has been modeled by rigorous and versatile eigen mode expansion method. Based on the simulation result, the authors are able to determine the sample strain under the mechanical load by measuring the reflected Bragg wavelength. Moreover, the measured strain is compared with the strain analytically obtained from the known force applied on the sample. The both strains are in good agreement.

The paper deals with the experimental analysis focused on the determination of strain in wooden building structures using optical fibers with FBG sensors. Firstly, optical fibers were used to measure displacements of layers and surface strain of the lower surface of the ceiling panels made from mechanically jointed cross laminated timber (CLT). The measured displacement values of the optical fibers were compared with the results obtained from the inductive displacement sensors. Secondly, optical fibers were used for long-term monitoring of the roof structure of the sports hall. The fibers were mounted on chords of timber trusses and their correct function was verified by a load test.

A new method was developed for calibration a multi-sensory system which contains one tri-axial accelerometer and two triaxial magnetometers. The system is used for navigation of horizontal direction drilling. The method calculates the misalignment error (angular and offset) to mutually align all sensors. Specific rotations of the whole system are carried out and the errors are calculated by the optimization method from the recorded sensor data. By applying of correction matrices into the navigation algorithm, the error of the navigation unit was reduced to 0.5 meters in the 30-meter distance.

Navigation, position tracking, search for unexploded ammunition, and geophysical prospection of magnetic or conducting ore are key applications where very small magnetic field signatures and field increments should be detected in the presence of the Earth's magnetic field, typically 50,000 nT. The industry calls for a new generation of portable vectorial magnetic sensors with a precision better than 0.1 nT. This error requirement includes not only sensor noise but also linearity, cross-field error, hysteresis, and perming and also temperature drift of the sensitivity and mainly the offset drift. For application on moving platform, the sensors should also have fast response. We will show that these requirements can be met only by fluxgate sensors. On the other hand, mass market requires cheap, low-power, and small magnetic sensors for portable gadgets; the typical application is compass in mobile phone, with precision of several degrees, corresponding to a 100-nT precision. For these applications, anisotropic magnetoresistance (AMR) sensor is dominant, while integrated fluxgates may penetrate the high-end market.

Soft magnetic materials rich on iron or cobalt have found vast range of usability for sensors such as fluxgates and also, the recently re-invented, magneto-impedance sensors. Giant magnetoimpedance (GMI) has experienced huge increase of interest since the late 80's. Although the fluxgate sensor is commercially available, the easy manufacturing of GMI sensors, possibility of miniaturization put attention to many scientists for developing such sensor in many applications. However, GMI sensor has major drawback of large temperature sensitivity. In precise applications, fluxgate sensors are preferred over GMI, which do not saturate the ferromagnetic core and therefore may exhibit perming error. On the other side, the GMI sensors compete with significantly longer period of the development of fluxgates and recently are commercially used for evaluation of microstructural degradation in ferromagnetic materials. Mostly for GMI sensors, amorphous/ nanostructured wires are used rather than ribbons as wire shaped sample has better GMI characteristics than ribbon due to the formation of circumferential anisotropy in wire. On the other hand wires can be used for orthogonal fluxgates but ribbons are preferred over wires for commercial use as they have been tested for last few decades. The magnetization process for the ribbon and the wire shaped samples are assumed to be different presumably due to the difference in cooling process. However, in both cases, the materials should have very low saturation magnetostriction constant and high permeability. The present paper is to understand the variation of sensing properties of the ribbon and wire shaped materials having the same composition, which can be operated both in the GMI and the fluxgate sensing cores and test them in both sensors.