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Sprinkler system can be very reliable and effective way to reduce fire risks in buildings if maintained properly. When the sprinkler system operates as designed, the temperatures affecting the load-bearing structures are often relatively low and the structural resistance is typically not compromised. Holistic Structural Fire Engineering (SFE) provides an opportunity to take active systems, like sprinklers, into account in the design. However, it is important to ensure that if the sprinkler system does not operate as designed, the consequences are still tolerable. Even though there are options to account sprinkler system in SFE, there is a lack of consistent guideline (at least in Finland). This can lead to totally different structural fire design and safety in similar buildings, depending on the interpretation and assumptions made. This paper presents a framework to take the effect of the sprinkler system consistently into account in SFE. The framework is based on Finland’s fire regulations and on experience of multiple projects. Two case-examples, where this framework has been applied are presented in the paper.

We present the application of a simple probabilistic methodology to determine the reliability of a structural element exposed to fire when designed following Eurocode 1-1-2 (EC1). Eurocodes are being used extensively within the European Union in the design of many buildings and structures. Here, the methodology is applied to a simply-supported, reinforced concrete slab 180 mm thick, with a standard load bearing fire resistance of 90 min. The slab is subjected to a fire in an office compartment of 420 m2 floor area and 4 m height. Temperature time curves are produced using the EC1 parametric fire curve, which assumes uniform temperature and a uniform burning condition for the fire. Heat transfer calculations identify the plausible worst case scenarios in terms of maximum rebar temperature. We found that a ventilation-controlled fire with opening factor 0.02 m1/2 results in a maximum rebar temperature of 448°C after 102 min of fire exposure. Sensitivity analyses to the main parameters in the EC1 fire curves and in the EC1 heat transfer calculations are performed using a one-at-a-time (OAT) method. The failure probability is then calculated for a series of input parameters using the Monte Carlo method. The results show that this slab has a 0.3% probability of failure when the compartment is designed with all layers of safety in place (detection and sprinkler systems, safe access route, and fire fighting devices are available). Unavailability of sprinkler systems results in a 1% probability of failure. When both sprinkler system and detection are not available in the building, the probability of failure is 8%. This novel study conducts for the first time a probabilistic calculation using the EC1 parametric curve, helping engineers to identify the most critical design fires and the probabilistic resistance assumed in EC1.

The prevalence of high-rack warehouses and large-space facilities with high ceilings poses significant challenges to traditional automatic sprinkler systems, which often exhibit activation delays and limited suppression efficacy. This study investigates the spatio-temporal evolution and distribution characteristics of fire-induced thermal smoke flow through a hybrid approach combining full-scale fire experiments and numerical simulations. A physical hypothesis is proposed: the ceiling temperature field approximately follows a two-dimensional Gaussian distribution. Through parametric numerical simulations under varied ambient temperatures, fire identification criteria were calibrated, encompassing a sustained increase in the average temperature rise within high-temperature zones, the attainment of a predefined threshold, and the spatial stabilization of the Gaussian distribution center. Subsequently, a precise algorithm for rapid fire identification and source localization was developed. Experimental validation demonstrates that the proposed algorithm significantly outperforms traditional passive-activation closed sprinklers, advancing fire detection by 46–67 s. Furthermore, the fire source localization error is maintained within half of the sprinkler spacing. The algorithm also exhibits robust environmental adaptability and generalizability across a wide ambient temperature range, providing a technical foundation for active-actuation fire suppression.

Window sprinklers are commonly used to protect glass, but there is a lack of research on the effect of fire scale on protection. In this study, full-scale experiments on sprinkler-protected glass in building fires were carried out. The experimental process was simulated using CFD numerical simulation software (FDS), and the effect of the heat release rate on the protection effect was revealed based on the glass surface temperature and heat insulation efficiency. It was found that in a full-size compartment fire, the window sprinkler was able to protect the glass from being damaged by high-temperature smoke. The numerical simulation could effectively simulate the spray distribution pattern of a window sprinkler as well as the gas temperature evolution, and the simulation results matched well with the full-size experiments. The window surface temperatures all decreased rapidly and increased linearly with the HRR after the window sprinkler was activated. The steady-state window center temperatures were 40 °C, 60 °C and 76 °C when the HRR was 2 MW, 4 MW and 6 MW, respectively. The window center temperature was less than the critical temperature of glass breakage, indicating that the window sprinkler could protect the glass from fire damage well, within the fire scale of 6 MW. The thermal insulation efficiency in the edge region was slightly lower than that in the center of the window. In the range of 2 to 6 MW, there was no significant correlation between the thermal insulation efficiency and the HRR, and the thermal insulation efficiency was in the range of 54% to 59%.

This research evaluated the importance of establishing an integrated sprinkler irrigation design connected to fish farm ponds in order to achieve environmental and financial benefits. To achieve the aim of the study, two field experiments were conducted at a private farm in the Nubaria area of Beheira Governorate during the 2022 and 2023 seasons to quantify all the benefits from using fish water effluent (FWE) in irrigation. The obtained results indicated that the effluent could represent a good source of irrigation and bio-fertilization. The yield of tomato was higher when using FWE for irrigation compared with using groundwater for irrigation (IW). This was due to the additional amounts of dissolved bio-nitrogen along with other nutrients present in the FWE. The proportion of dissolved nitrogen added by using FWE was 22.3 kg nitrogen per hectare in 2022 and 24.6 kg nitrogen per hectare in 2023, in addition to some other major elements such as phosphorus and potassium, which are also among the main nutrients needed by crops. It has also been noticed that the fertility of the sandy soil increased with the use of FWE for irrigation. One of the most important results was the possibility of reducing the addition of nitrogen mineral fertilizers by 25%, thus saving on N fertilizers when growing tomato. In addition to the vitality of the FWE and its macro- and microelements, algae, microorganisms, and other organic materials, the use of this type of water as an alternative source for irrigation, along with the reduction in the amount of added mineral fertilizers, will reduce the degree of groundwater contamination with mineral fertilizers and increase the income of farmers. It was also observed that the air temperature decreased during the growing season when compared with the temperature of uncultivated surrounding areas.

The Christiansen Uniformity Coefficient (CUC) describes the distribution of water in a sprinkler system. In this study, two types of models were developed to predict the Christiansen Uniformity Coefficient (CUC) of sprinkler irrigation systems: Artificial Neural Network (ANN), specifically the feed-forward neural networks, and multiple linear regression (MLR) models. The models were trained on a dataset of published research on the CUC of sprinkler irrigation systems, which included data on a variety of design, operating, and meteorological condition variables. In order to build the predictive model of CUC, 10 input parameters were used including sprinkler height (H), working pressure (P), nozzle diameter (D and da), sprinkler line spacing (SL), sprinkler spacing (SS), wind speed (WS), wind direction (WD), temperature (T), and relative humidity (RH). Fifty percent (50%) of the data was used to train ANN models and the remaining data for cross-validation (25%) and for testing (25%). Multiple linear regression models were built using the training data. Four statistical criteria were used to evaluate the model’s predictive quality: the correlation coefficient (R), the index of agreement (d), the root mean square error (RMSE), and the mean absolute error (MAE). Statistical analysis demonstrated that the best predictive ability was obtained when the models (ANN and MLR) utilized all the input variables. The results demonstrated that the accuracy of ANN models, predicting the CUC of sprinkler irrigation systems, is higher than that of the MLR ones. During the training stage, the ANN models were more accurate in predicting CUC than MLR, with higher R (0.999) and d (0.999) values and lower MAE (0.167) and RMSE (0.456) values. The R values of the MLR model fluctuated between 0.226 and 0.960, the d values oscillated from 0.174 to 0.979, the MAE values were in the range of 2.458% and 10.792%, and the RMSE values fluctuated from 2.923% to 13.393%. Furthermore, the study revealed that WS and WD are the most influential climatic parameters. The ANN model can be used to develop more accurate tools for predicting the CUC of sprinkler irrigation systems. This can help farmers to design and operate their irrigation systems more efficiently, which can save them time and money.

Since being released 40 years ago, computer spreadsheets have proven to be worthwhile for use in educational contexts. There is plenty of evidence for this in practically every scientific discipline and engineering field. In view on this fact, the present work exposes a didactical resource, named the sprinkler irrigation tool, developed in Excel® spreadsheet licensed by 2018 Microsoft©. The objective of this tool is to offer an alternative to students in irrigation engineering, particularly for those training in the design of sprinkler irrigation systems so they can develop their theoretical knowledge and practical skills acquired in laboratory and field experiments. The main findings reported in this paper address well-agreed methodologies for evaluating radial patterns of precipitation rates, diameter distribution frequency, ballistic simulation of water drops’ movement through air, kinetic energy, and performance indicators as part of the core parameters of efficient irrigation system management. This computing tool provides outcomes in tabular and graphical formats that are consistent with those found in studies previously published in specialized literature on related topics. Likewise, spreadsheets have been proven to be adequate pedagogical instruments on the path to achieving meaningful learning; however, this assertion still needs to be confirmed through a rigorous study of students who have used the developed tool.

It is common for agencies around the world to conduct some form of cost-benefit analysis (CBA) when proposing an investment in a safety measure. Since resources are limited, expenditure on one particular safety measure effectively means that there are not the resources available for other measures. Due to finite financial resources, an investment in a safety scheme will require a trade-off elsewhere. As such, the objective of a CBA is to assess whether the proposed measure provides a net benefit to society or whether resources would be better directed elsewhere. Fire safety measures, such as sprinkler systems, are one means to mitigate the risk posed by fire in buildings. Sprinkler systems have a long record of property and life protection but there is a cost associated with their installation and ongoing maintenance. For many years various agencies have examined whether sprinkler systems should be mandated in some or all buildings within their jurisdiction, and as a result have conducted different forms of CBA. However, there are a number of challenges when carrying out such assessments particularly when it comes to placing an economic value on human life. This paper revisits three previous CBA available in the literature for the installation of residential (domestic) sprinkler systems in single family dwellings. The paper applies recent work to extend the J-value methodology which employs the life quality index (LQI) concept as a mean of valuing the benefit of increasing life expectancy through the mitigation or reduction in the occurrence rate of a hazard. Similar to the previous studies investigated, the paper finds that the unilateral installation of sprinkler systems in single family homes does not provide a net benefit to society. This conclusion is reached through the adoption of a novel and objective judgement scalar that is easy to implement and interpret.

This paper presents frequency reconfigurability of a microstrip patch antenna using a nickel-titanium (Ni-Ti) shape memory alloy (SMA). It comprises a radiating patch made up of Ni-Ti SMA. It is characterized by differential scanning calorimetry, four-probe method and x-ray diffraction in order to evaluate transformation temperatures, electrical resistivity and different phases present in the material, respectively. Currently, a fire sprinkler system consists of a “wet alloy” which will expand when heated initially and then breaks allowing water to sprinkle onto the fire. The present work uses a two-way Ni-Ti SMA which is used to actuate the fire sprinkler system, triggers a sound alarm and is also able to send a message via SMS to the administrator. A microstrip patch antenna is designed, fabricated and measured for reflection coefficient, radiation pattern, and antenna gain at flat and bent configurations. The antenna operates at 2.4 GHz in the flat condition and 3.8 GHz in the bent configuration. This patch antenna can be used in fire alarms which actuate at 66°C and stop the fire without causing much damage. Unlike a conventional fire alarm system, proposed fire sprinkler designed with a Ni-Ti SMA can be reused several times.