Permeable pavements are specifically designed to promote the infiltration of stormwater through the paving surface in order to reduce run-off volumes and to improve water quality by removing sediment and other pollutants. However, research has shown that permeable pavements can become clogged over time and this reduces their infiltration capacity. In order to assess the infiltration of permeable pavements, a variety of infiltration test procedures have been utilised in the past. However, the results have generally been inconsistent, and have shown a large variation in the range of infiltration rates measured. This paper evaluates the performance of two new experimental test methods developed in the Netherlands to more accurately determine the surface infiltration rate of existing permeable pavement installations. The two methods were the falling head full-scale method and the constant head full-scale method. Both of the new methods involved inundating a large area of the pavement in order to determine the infiltration rate through the pavement surface. Double ring infiltrometer tests were also performed to enable a comparison of the results. The study found that the new falling head full-scale testing method produced the most accurate results.
OBJECTIVE: Loneliness and social isolation are pressing issues that can seriously impact the mental health and well-being of older adults. Interacting with nature can stimulate a feeling of connectedness. However, for older adults, access to nature is often troublesome because of physical limitations and mobility restrictions.METHODS: In the present mixed-method study, 37 older adults (62-99 years old) with varying care needs and mobility restrictions watched a video presenting a walkthrough of a simulated digital nature landscape.RESULTS: Quantitative results show a significant increase in social connectedness scores and enhanced peacefulness after experiencing a digital nature. Qualitative results stress the importance of variations in nature scenery and highlight the influence of contextual and person-related factors including nature experiences throughout the life span and mobility constraints that older adults may face.CONCLUSION: These findings testify to the potential of using digital nature as a complementary strategy when interactions with outdoor nature become increasingly difficult due to old age.
A local operating theater ventilation device to specifically ventilate the wound area has been developed and investigated. The ventilation device is combined with a blanket which lies over the patient during the operation. Two configurations were studied: Configuration 1 where HEPA-filtered air was supplied around and parallel to the wound area and Configuration 2 where HEPA-filtered air was supplied from the top surface of the blanket, perpendicular to the wound area. A similar approach is investigated in parallel for an instrument table. The objective of the study was to verify the effectiveness of the local device. Prototype solutions developed were studied experimentally (laboratory) and numerically (CFD) in a simplified setup, followed by experimental assessment in a full scale mock-up. Isothermal as well as non-isothermal conditions were analyzed. Particle concentrations obtained in proposed solutions were compared to the concentration without local ventilation. The analysis procedure followed current national guidelines for the assessment of operating theater ventilation systems, which focus on small particles (<10 mm). The results show that the local system can provide better air quality conditions near the wound area compared to a theoretical mixing situation (proof-of-principle). It cannot yet replace the standard unidirectional downflow systems as found for ultraclean operating theater conditions. It does, however, show potential for application in temporary and emergency operating theaters
Windenergie speelt een sleutelrol in de transitie naar duurzame energie. Echter, rotorbladen van windmolens zijn niet te recyclen omdat deze uit thermoharde vezel-versterkte kunststof (composiet) zijn vervaardigd. Dit levert wereldwijd een groeiend probleem van End-of-Life (EoL) rotorbladen. Het Lectoraat Kunststoftechnologie (LKT) van Windesheim heeft een nieuwe methode van hergebruik ontwikkeld voor EoL producten van composiet. Deze methode levert een goede business case vanwege economische haalbaarheid en (milieu-) duurzaamheid en brengt daarmee composieten, zoals rotorbladen in de circulaire economie. Hierbij is een lange levensduur van deze producten belangrijk. De industrialisatie van deze nieuwe methode begint zich te ontwikkelen, vooral in de infra-bouw. Een knelpunt is dat producenten en gebruikers een onderbouwing nodig hebben van de lange-duur prestatie van EoL composiet producten. Vanuit de betrokken bedrijven komt daarom de volgende praktijkvraag naar voren: Wat is de lange-duur prestatie van producten vervaardigd met hergebruikt EoL composiet? Uit vooronderzoeken van LKT blijkt dat het mogelijk is om met simulaties van tijdsafhankelijke processen voorspellingen te doen over de prestatie van producten gemaakt van hergebruikt EoL composiet. Om de simulaties te valideren zijn versnelde tests nodig van het lange-duur gedrag. Prestaties die worden onderzocht zijn: de bestendigheid tegen inwerking van buitenklimaat, invloed van permanente- en wisselende belastingen. Dit project richt zich op de volgende onderzoeksvraag: Wat is de prestatie van producten vervaardigd met hergebruikt EoL composiet in Nederlandse infra-toepassingen over een periode van 100 jaar, welke is verkregen met simulaties van tijds-afhankelijke processen en gevalideerd met versnelde tests? Vanwege het toepassingsgebied zullen de omstandigheden waarbij de prestatie wordt onderzocht overeenkomen met Nederlandse infrabouw-omstandigheden, waarbij oeverbeschoeiing en brugdekken als onderzoeks-demonstrators dienen. Het beoogde projectresultaat is een onderbouwing middels simulaties en tests van de lange-duur prestatie van producten van hergebruikt EoL composiet in Nederlandse infra-bouw omstandigheden. Hiermee kan de markt voor hergebruikt EoL composiet ontsloten worden.
