New glass coatings for high insulating greenhouses without light losses - energy saving crop production and economic potentials

More than 90% of the Dutch greenhouse area is covered with single glass. Energy losses through the covering are high during the heating period (winter) but energy requirements are also high during the cooling period (summer) in the case of semi-closed greenhouses. Until now, light losses of insulating coverings prevented growers from using double glass or plastic film. However, increasing energy prices allow new developments. Wageningen UR Greenhouse Horticulture studied the possibilities to use modern glass coatings to increase light transmission and save energy. Several glass types (standard glass, 90+ glass, low-iron glass) were covered with different anti-reflection coatings from different producers. Double glasses were produced; their optical properties were determined. It was possible to produce double glasses with new coatings having a higher light transmission than traditional single greenhouse glass (83-85% for hemispherical (diffuse) light, compared to 82-83% for traditional single glass) and a k-value of 3.6 W m-2 K-1 (compared to7.6 W m-2 K-1 of a traditional single glass). Other double glasses were produced using a combination of anti-reflection and modern low-emission coatings, reaching an even lower k-value of ˜2.4 W m-2 K-1, however, showing a slight light loss (78.5% for hemispherical (diffuse) light). Calculations of greenhouse climate (temperature, humidity, CO2) and energy consumptions year-round were carried out with a validated dynamic climate model. Additionally the effects on tomato production (dry matter) were calculated for the different prototypes of coated and insulated glass. Double materials show the highest energy saving with 25-33%, depending on the composition but also low-emission coatings on single glass decrease the energy use with 15-20%. Economic calculations with current tomato and energy prices showed that single and double glasses with anti-reflection coating currently have the highest potential

Development of an Analysis Process to Assess the Quality of Research Knowledge Graphs

This thesis proposes a novel approach for assessing the quality objectively of knowledge graphs, with a particular focus on the Open Research Knowledge Graph (ORKG). The ORKG is a community-driven open platform that aims to make research contributions more discoverable, accessible, and reusable. As a critical component of modern information systems, knowledge graphs enable effective data integration, discovery, and retrieval. However, assessing the quality of these graphs is challenging, given their complexity and heterogeneity. The main problem addressed in this thesis is to develop an approach to assess the quality of knowledge graphs, with a particular emphasis on completeness and accuracy, in the context of the ORKG. The proposed approach is based on a set of quality measures that evaluate different aspects of completeness and accuracy, and it leverages the Knowledge Graph Maturity Model (KGMM) as a framework for assessing the maturity level of the ORKG. The solution is evaluated empirically using a set of ORKG curation grants, and the observed results demonstrate that the proposed approach can effectively identify gaps in completeness and accuracy, and provide a comprehensive assessment of the quality of the ORKG. This assessment can help the ORKG community to prioritize curation efforts and improve the quality of the ORKG. Overall, this thesis contributes to the field of knowledge graph quality assessment by proposing a comprehensive approach for assessing the quality of knowledge graphs, and demonstrating its effectiveness in the context of the ORKG. The proposed approach has the potential to be applied to other knowledge graphs, enabling better data integration, discovery, and retrieval in various domains.In dieser Arbeit wird ein neuartiger Ansatz zur objektiven Bewertung der Qualität von Wissensgraphen vorgeschlagen, wobei der Schwerpunkt auf dem Open Research Knowledge Graph (ORKG) liegt. Der ORKG ist eine von der Gemeinschaft betriebene offene Plattform, die darauf abzielt, Forschungsbeiträge besser auffindbar, zugänglich und wiederverwendbar zu machen. Wissensgraphen sind ein wichtiger Bestandteil moderner Informationssysteme und ermöglichen eine effektive Datenintegration, -suche und -abfrage. Die Bewertung der Qualität dieser Graphen ist jedoch angesichts ihrer Komplexität und Heterogenität eine Herausforderung. Das Hauptproblem, das in dieser Arbeit behandelt wird, ist die Entwicklung eines Ansatzes zur Bewertung der Qualität von Wissensgraphen, mit besonderem Schwerpunkt auf Vollständigkeit und Genauigkeit, im Kontext des ORKG. Der vorgeschlagene Ansatz basiert auf einer Reihe von Qualitätsmaßstäben, die verschiedene Aspekte der Vollständigkeit und Genauigkeit bewerten, und er nutzt das Knowledge Graph Maturity Model (KGMM) als Rahmen für die Bewertung des Reifegrads des ORKG. Die Lösung wird empirisch anhand einer Reihe von ORKG-Kuratoren evaluiert. Die Ergebnisse zeigen, dass der vorgeschlagene Ansatz effektiv Lücken in der Vollständigkeit und Genauigkeit identifizieren kann und eine umfassende Bewertung der Qualität des ORKG ermöglicht. Diese Bewertung kann der ORKG-Gemeinschaft helfen, Prioritäten bei der Kuratierung zu setzen und die Qualität des ORKG zu verbessern. Insgesamt leistet diese Arbeit einen Beitrag zur Bewertung der Qualität von Wissensgraphen, indem sie einen umfassenden Ansatz zur Bewertung der Qualität von Wissensgraphen vorschlägt und dessen Wirksamkeit im Kontext des ORKG demonstriert. Der vorgeschlagene Ansatz hat das Potenzial, auf andere Wissensgraphen angewendet zu werden, um eine bessere Datenintegration, -suche und -abfrage in verschiedenen Bereichen zu ermöglichen

Effects of Drought Stress on Photosynthesis Factors in Wheat Genotypes during Anthesis

Drought is one of most important environmental factors inhibiting photosynthesis and decreasing growth and productivity of plants. The sensitivity of crop plants such as wheat to soil drought is particularly serious during reproductive phase is extremely sensitive to plant water status. The aim of this work was to study the effects of drought stress on photosynthesis, photosynthetic pigments, soluble proteins, a-tocopherol and abscisic acid content in six wheat genotypes, two tolerant (Daric and 92 Zhong), two moderately tolerant (Sabalan and DH-2049-3) and two sensitive (Shark and Tevee’s’). Total chlorophyll content, relative water content and chlorophyll a/b ratio decreased after long-time drought stress, that decrease in sensitive genotypes was higher than others. Net photosynthesis and stomatal conductance decreased significantly (P < 0.05) in flag leaves of our genotypes under drought stress after pollination, that decrease in sensitive genotypes was higher, too. Abscisic acid content, soluble protein content and a-tocopherol increased under drought stress, that increase in tolerant genotypes was higher. There was a significant negative correlation (P < 0.05) between photosynthesis factors and abscisic acid content in flag leaves of all genotypes. It can be concluded that Daric and 92 Zhong had a better photosynthesis factors compared to other genotypes and showed a higher capacity to tolerate drought stress