On the feasibility of watertight face-sealed window-wall interfaces

Watertightness is still a major source of concern in the performance of the building envelope. Even very small deficiencies can cause a significant amount of water leakage which may result in structural degradation or malfunctioning of the insulation. The risk of water infiltration is highest at joints between different building components and in particular at the window-wall interface due to the complexity of these joints. This paper focuses on the performance of different solutions to ensure the watertightness of the window-wall interface, e.g. self-adhesive foils, liquid applied coatings, prefabricated frames, self-expanding sealing strips. The performance of these solutions is evaluated for different wall assemblies, i.e. ETICS, masonry, structural insulated panels and wood-frame construction. Laboratory experiments were conducted on a full-scale test setup with a window of 1,01 m high and 0,56 m wide. Test results showed that it is not evident to obtain watertight face-sealed window-wall interfaces without an additional airtight layer or drainage possibilities. Water ingress was often recorded at lower pressure differences

Drainage and retention of water in small drainage cavities : experimental assessment

Water that enters the drainage cavity of a rain screen wall assembly through deficiencies in the cladding will either be drained or retained by absorption or adhesion on the drainage surfaces. The objective of this study is to gain insight into the different factors that affect the quantity of water drained or retained in a drainage cavity. Drainage tests have been conducted for water flowing between two vertical polycarbonate plates with different gap widths to determine the effect on the drainage rate. Tests showed that even small cavities with a width of 1 mm can already drain more water than the amount that would enter the cavity during a rain event. Experiments were performed to determine the contact angle of water on a range of different sheathing materials such as asphalt saturated building paper, spun-bonded polyethylene wrap and cross-woven polyolefin wrap by the use of an optical goniometer. Drainage tests have been conducted for different combinations of these materials to quantify the effect of surface energy on the drainage rate. A larger contact angle results in a smaller quantity of water retained during the drainage test. These tests result in a retained portion of water and a drainage rate for different combinations of materials. The retained portion of water may be considered as a moisture load applied to the outer-most layer of the wall assembly’s back-up wall in hygrothermal simulations

Rainwater management of ventilated facades : impact of joint width and cavity size

During a rain event, most of the raindrops reaching the facade either splash back or run off the exterior surface of the facade. However, it is evident that also a portion of the water infiltrates through the open joints of a ventilated facade. The infiltrated water may either be drained in the cavity to the bottom of the wall or reach the insulation layer. If there are any deficiencies present in the insulation layer or at the connection of the brackets, the infiltrated water might introduce problems. Additionally, if the cavity is not able to drain all the infiltrated water or adhered droplets to one of the cavity surfaces do not dry out, moisture problems might occur. Experiments were conducted to determine the infiltration rate through ventilated facades with open joint widths of 5 mm, 10 mm and 15 mm and cavity widths ranging from 190 mm to 40 mm. It was observed that the amount of infiltrating water was larger for larger joints widths. Due to the larger kinetic energy of the drops flowing through the larger joint widths, the drops were able to reach the exterior surface of the insulation layer, even for large cavity widths. The results from the experimental assessment were used as input parameters for hygrothermal simulations to determine the risk of moisture problems

Drainage and retention of water in small drainage cavities: Experimental assessment

Water that enters the drainage cavity of a rain screen wall assembly through deficiencies in the cladding will either be drained or retained by absorption or adhesion on the drainage surfaces. The objective of this study is to gain insight into the different factors that affect the quantity of water drained or retained in a drainage cavity. Drainage tests have been conducted for water flowing between two vertical polycarbonate plates with different gap widths to determine the effect on the drainage rate. Tests showed that even small cavities with a width of 1 mm can already drain more water than the amount that would enter the cavity during a rain event. Experiments were performed to determine the contact angle of water on a range of different sheathing materials such as asphalt saturated building paper, spun-bonded polyethylene wrap and cross-woven polyolefin wrap by the use of an optical goniometer. Drainage tests have been conducted for different combinations of these materials to quantify the effect of surface energy on the drainage rate. A larger contact angle results in a smaller quantity of water retained during the drainage test. These tests result in a retained portion of water and a drainage rate for different combinations of materials. The retained portion of water may be considered as a moisture load applied to the outer-most layer of the wall assembly’s back-up wall in hygrothermal simulations

Known, lost, and recovered: Efficacy of formal-semantic therapy and spaced retrieval method in a case of semantic dementia

peer reviewedBackground: Few studies have addressed rehabilitation in semantic dementia. A potentially promising method is formal-semantic therapy, which consists of tasks in which the names of concepts and their semantic characteristics are presented. It could also be enhanced by spaced retrieval, a learning method improving retention through recalling information after increasing recall intervals. Aims: This study explores the efficacy of both a formal-semantic therapy and the spaced retrieval method to restore lost concepts in TBo, a woman with semantic dementia. Methods & Procedures: The formal-semantic therapy consisted of giving TBo semantic feedback followed by a cueing technique to facilitate naming. Formal-semantic therapy with simple repetition was compared to formal-semantic therapy with spaced retrieval. TBo's performance was measured throughout the study with picture naming and generation of verbal attributes. Two untrained lists were also measured for generalisation effects. Outcomes & Results: Results indicate that, after therapy, TBo could name 3/8 of the trained items, compared to no items on the untrained lists. She also showed an increase in performance for the evocation of specific semantic attributes of concepts, reaching 6/8 of correct responses. Moreover, she maintained her performance up to 5 weeks after the end of the study. Finally, when compared to simple repeated practice, spaced retrieval did not enhance learning and no generalisation was observed between trained and non-trained categories. Conclusions: Along with recent results reported in the literature, TBo's results confirm that people with semantic dementia can improve their naming performance with training but that this is limited. However, formal-semantic therapy seems very promising for retraining specific semantic attributes. Instead of focusing on naming, we suggest that therapies used in semantic dementia should aim at restoring specific and functionally relevant concepts to enable the individuals to be more autonomous in daily living

Positive and Negative Urgency as a single coherent construct: Evidence from a large‐scale network analysis in clinical and non‐clinical samples

Aims: Negative and positive urgency are emotion-related impulsivity traits that are thought to be transdiagnostic factors in psychopathology. However, it has recently been claimed that these two traits are closely related to each other and that considering them separately might have limited conceptual and methodological value. The present study aimed to examine whether positive and negative urgency constructs constitute separate impulsivity traits. Methods: In contrast to previous studies that have used latent variable approaches, this study employed an item-based network analysis conducted in two different samples: a large sample of non-clinical participants (N = 18,568) and a sample of clinical participants with psychiatric disorders (N = 385). Results: The network analysis demonstrated that items denoting both positive and negative urgency cohere as a single cluster of items termed “general urgency” in both clinical and non-clinical samples, thereby suggesting that differentiating positive and negative urgency as separate constructs is not necessary. Conclusion: These findings have important implications for the conceptualization and assessment of urgency and, more broadly, for future research on impulsivity, personality, and psychopathology

Spatial Learning Depends on Both the Addition and Removal of New Hippocampal Neurons

The role of adult hippocampal neurogenesis in spatial learning remains a matter of debate. Here, we show that spatial learning modifies neurogenesis by inducing a cascade of events that resembles the selective stabilization process characterizing development. Learning promotes survival of relatively mature neurons, apoptosis of more immature cells, and finally, proliferation of neural precursors. These are three interrelated events mediating learning. Thus, blocking apoptosis impairs memory and inhibits learning-induced cell survival and cell proliferation. In conclusion, during learning, similar to the selective stabilization process, neuronal networks are sculpted by a tightly regulated selection and suppression of different populations of newly born neurons