Onze leef- en werkomgeving heeft invloed op onze gezondheid, maar het nauwkeurig bepalen van persoonlijke blootstelling aan verschillende milieufactoren blijft een uitdaging. Toch is dit wel van belang, omdat bijvoorbeeld de blootstelling aan fijnstof, stikstofdioxide en ozon jaarlijks al leidt tot 12.000 vroegtijdige sterfgevallen in Nederland (Gezondheidsraad, 2018). In werkomgevingen zijn er behalve voor de genoemde stoffen ook nog andere vluchtig organische stoffen en chemicalen waarvan de blootstelling op de korte of lange termijn tot negatieve gezondheidseffecten kan leiden. Ook fysische blootstellingen kunnen negatieve gezondheidseffecten hebben, zoals geluid, UV-straling, elektromagnetische velden en trillingen.
The indoor air quality (IAQ) in classrooms in higher education can influence in-class activities positively. In this context, the actual IAQ and students' perceived IAQ (PIAQ), perceived cognitive performance (PCP), and short-term academic performance (SAP) were examined in two identical classrooms during regular academic courses. During the lecture, key performance indicators (KPI) for the IAQ, i.e. carbon dioxide concentration, particulate matter 2.5, and total volatile organic compounds, were measured. After the lecture, responses of 163 students were collected with a validated self-composed questionnaire and a cognitive test, which covered topics discussed during the lecture. A significant association between the IAQ KPI and the PIAQ was found (p < .000). The PIAQ significantly predicted the PCP (p < .05) and the PCP significantly predicted the SAP score (p < .01). These results indicate that the IAQ in classrooms is associated with the PIAQ and PCP, and therefore is associated with students' SAP.
Abstract Background: COVID-19 was first identified in December 2019 in the city of Wuhan, China. The virus quickly spread and was declared a pandemic on March 11, 2020. After infection, symptoms such as fever, a (dry) cough, nasal congestion, and fatigue can develop. In some cases, the virus causes severe complications such as pneumonia and dyspnea and could result in death. The virus also spread rapidly in the Netherlands, a small and densely populated country with an aging population. Health care in the Netherlands is of a high standard, but there were nevertheless problems with hospital capacity, such as the number of available beds and staff. There were also regions and municipalities that were hit harder than others. In the Netherlands, there are important data sources available for daily COVID-19 numbers and information about municipalities. Objective: We aimed to predict the cumulative number of confirmed COVID-19 infections per 10,000 inhabitants per municipality in the Netherlands, using a data set with the properties of 355 municipalities in the Netherlands and advanced modeling techniques. Methods: We collected relevant static data per municipality from data sources that were available in the Dutch public domain and merged these data with the dynamic daily number of infections from January 1, 2020, to May 9, 2021, resulting in a data set with 355 municipalities in the Netherlands and variables grouped into 20 topics. The modeling techniques random forest and multiple fractional polynomials were used to construct a prediction model for predicting the cumulative number of confirmed COVID-19 infections per 10,000 inhabitants per municipality in the Netherlands. Results: The final prediction model had an R2 of 0.63. Important properties for predicting the cumulative number of confirmed COVID-19 infections per 10,000 inhabitants in a municipality in the Netherlands were exposure to particulate matter with diameters <10 μm (PM10) in the air, the percentage of Labour party voters, and the number of children in a household. Conclusions: Data about municipality properties in relation to the cumulative number of confirmed infections in a municipality in the Netherlands can give insight into the most important properties of a municipality for predicting the cumulative number of confirmed COVID-19 infections per 10,000 inhabitants in a municipality. This insight can provide policy makers with tools to cope with COVID-19 and may also be of value in the event of a future pandemic, so that municipalities are better prepared.
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Duurzaam beheerde landbouwbodems bevorderen de bodemvruchtbaarheid, zijn beter bestand tegen de klimaatveranderingen, zorgen voor schoner oppervlakte- en grondwater, een hogere biodiversiteit en het vastleggen van koolstof. Er is grote behoefte aan onderbouwde handelingsperspectieven voor koolstofvastlegging zonder nadelige effecten op nitraatuitspoeling door verhoogde mineralisatie, maar vooralsnog ontbreekt het aan praktische meet- en monitoringsmethoden van organische stof en stikstof in de bodem. Recent onderzoek laat zien dat er mogelijk een nieuwe indicator is voor koolstofvastlegging: Mineral Associated Organic Matter (MAOM) in relatie tot Particulate Organic Matter (POM). Het microbiële bodemleven is de belangrijkste regulator van de koolstofcyclus in de bodem en de omzetting van organische stof in POM en MAOM. Bij de microbiële afbraak van organisch materiaal, zoals gewasresten (blad en wortels), wortelexudaten, organische mest of compost, worden grote koolstofverbindingen enzymatisch afgebroken tot kleine koolstofverbindingen, die dienen als voedsel voor het bodemleven. Deze kleine koolstofverbindingen en de resten van afgestorven micro-organismen kunnen gemakkelijk worden gebonden en ingekapseld door kleideeltjes (MAOM). Daarmee zijn ze fysisch afgeschermd voor verdere afbraak en dus stabiel. De vorming van MAOM worden sterk gestuurd door de samenstelling van zowel het aangevoerde organische materiaal als van het bodemleven. In de praktijk betekent dit dat de keuzes die een agrariër maakt in het bouwplan (gewaskeuze) en bodembeheer (o.a. organische stofaanvoer en grondbewerking) grote invloed hebben op de vorming van MAOM en daarmee op de koolstofvastlegging. Dit project richt zich op metingen aan POM en MAOM in praktijksituaties en langlopende systeemproeven, het berekenen van de koolstof- en stikstofdynamiek en een DNA-analyse van het bodemmicrobioom. In combinatie met een knelpuntenanalyse in praktijksituaties kan dit inzicht geven in het handelingsperspectief voor agrariërs om duurzaam bodem- en waterbeheer te combineren met koolstofvastlegging op minerale grondsoorten.
The ongoing debate over the use of fossil fuels, particularly diesel, in engines due to concerns about global climate change has prompted the exploration of alternative propulsion methods and fuels. Despite various proposed alternatives, diesel engines continue to play a vital role in the global market [1]. This discussion has spurred innovations aimed at enhancing the performance and sustainability of diesel engines, including the utilization of biodiesel mixtures, synthetic fuels, and water-in-diesel emulsions (W/D emulsions) [2-5]. Scientific evidence indicates that the presence of water in water-diesel emulsions can improve engine performance and reduce emissions, such as particulate matter and NOx [6,7]. This performance enhancement is attributed to the phenomenon of micro-explosion, or secondary atomization, caused by the differing boiling points of water and diesel [8]. The rapid temperature increase during fuel injection leads to the explosive vaporization of dispersed water droplets, breaking up the diesel emulsion into smaller droplets and resulting in a shorter combustion time. Various processes, including membrane emulsification, ultrasound emulsification, and high shear stirring, are employed to create these emulsions, often necessitating the use of surfactants for stability [9]. This research proposes a two-fold approach: firstly, the use of Electrohydrodynamic Atomization (EHDA, or electrospray) to create stable water-diesel emulsions. Secondly, the employment of magnetic fields in treating both diesel and water-diesel emulsions. EHDA is already used in several applications, such as drug encapsulation, bioencapsulation, thin film coatings and is also known for its ability to form stable emulsions. [10-13]. For the second approach, it has been shown that nanobubbles can be formed [17] and stabilized due to the electric charging action of magnetic fields [18]. We hypothesize that the charged bubbles can further stabilize the diesel-water emulsion and also enhance the explosive evaporation due to the additional Coulomb forces in play.
