Numerical simulation study on the hygrothermal performance of building exterior walls under dynamic wind-driven rain condition

Wind-driven rain(WDR)has a significant influence on the hygrothermal performance,durability,and energy consumption of building components.The calculation of WDR loads using semi-empirical models has been incorporated into the boundary conditions of coupled heat and moisture transfer models.However,prior research often relied on fixed WDR absorption ratio,which fail to accurately capture the water absorption characteristics of porous building materials under rainfall scenarios.Therefore,this study aims to investigate the coupled heat and moisture transfer of exterior walls under dynamic WDR boundary conditions,utilizing an empirically obtained WDR absorption ratio model based on field measurements.The developed coupled heat and moisture transfer model is validated against the HAMSTAD project.The findings reveal that the total WDR flux calculated with the dynamic WDR boundary is lower than that obtained with the fixed WDR boundary,with greater disparities observed in orientations experiencing higher WDR loads.The variations in moisture flow significantly impact the surface temperature and relative humidity of the walls,influencing the calculation of cooling and heating loads by different models.Compared to the transient heat transfer model,the coupled heat and moisture transfer model incorporating dynamic WDR boundary exhibits maximum increases of 17.6%and 16.2%in cooling and heating loads,respectively.The dynamic WDR boundary conditions provide more precise numerical values for surface moisture flux,offering valuable insights for the thermal design of building enclosures and load calculations for HVAC systems.

Coupled heat and moisture transfer in walls featuring moisture-buffering materials and ventilating layers:An Experimental study

The moisture performance of building envelopes largely depends on the building materials,construction tech-niques,and exposure loads from the indoor and outdoor regions.A ventilated air interlayer placed in a wall can help dehumidify the wall and indoor air.This paper presents an experimental study of the heat,air,and moisture variations within the envelope wall of a chamber featuring different air interlayer settings under real outdoor air conditions during the summer of 2020 in Shanghai,China.Self-developed humidity-controlling building mate-rials were applied to the inner building envelope.Temperature,humidity,wind velocity,and heat-flow sensors were placed at different positions in the middle of the wall.These parameters were measured and recorded in real-time under three working conditions:humidification,dehumidification,and ventilation.The experimental results show that under the ventilation working conditions,moisture content of 0.52 kg can be removed after a 2-h air layer ventilation,which can benefit the design strategy for the humidification and ventilation of dehu-midification walls.

A nomogramfor predicting overall survival in patients with low-grade endometrial stromal sarcoma: A population-based analysis

Background:Low-grade endometrial stromal sarcoma(LG-ESS)is a rare tumor that lacks a prognostic prediction model.Our study aimed to develop a nomogram to predict overall survival of LG-ESS patients.Methods:A total of 1172 patients confirmed to have LG-ESS between 1988 and 2015 were selected from the Surveillance,Epidemiology and End Results(SEER)database.They were further divided into a training cohort and a validation cohort.The Akaike information criterion was used to select variables for the nomogram.The discrimination and calibration of the nomogram were evaluated using concordance index(C-index),area under time-dependent receiver operating characteristic curve(time-dependent AUC),and calibration plots.The net benefits of the nomogram at different threshold probabilities were quantified and compared with those of the International Federation of Gynecology and Obstetrics(FIGO)criteria-based tumor staging using decision curve analysis(DCA).Net reclassification index(NRI)and integrated discrimination improvement(IDI)were also used to compare the nomogram’s clinical utilitywith that of the FIGO criteria-based tumor staging.The risk stratifications of the nomogram and the FIGO criteria-based tumor staging were compared.Results:Seven variables were selected to establish the nomogram for LG-ESS.The C-index(0.814 for the training cohort and 0.837 for the validation cohort)and the time-dependent AUC(>0.7)indicated satisfactory discriminative ability of the nomogram.The calibration plots showed favorable consistency between the prediction of the nomogram and actual observations in both the training and validation cohorts.The NRI values(training cohort:0.271 for 5-year and 0.433 for 10-year OS prediction;validation cohort:0.310 for 5-year and 0.383 for 10-year OS prediction)and IDI(training cohort:0.146 for 5-year and 0.185 for 10-year OS prediction;validation cohort:0.177 for 5-year and 0.191 for 10-year OS prediction)indicated that the established nomogram performed significantly better than the FIGO criteria-based tumor staging alone(P<0.05).Furthermore,DCA showed that the nomogram was clinically useful and had better discriminative ability to recognize patients at high risk than the FIGO criteria-based tumor staging.Conclusions:A prognostic nomogram was developed and validated to assist clinicians in evaluating prognosis of LG-ESS patients.