Thermodynamic qualification of knitted spacer fabrics for use as insulation box insert in the context of refrigerated transport containers in the logistics sector

Temperature-sensitive products such as refrigerated and frozen goods pose particular challenges for logistics. Against the background of the mobility shift towards electric vehicles and the current challenges of temperature-stable transport in the field of pharmaceutical, esp. vaccine logistics in the context of the SARS-CoV-2 pandemic, new, energy-efficient vehicle equipment is needed to maintain cold chains. Known refrigeration concepts are designed to cool the entire cargo hold. In addition, the goods cannot be removed from the vehicle while maintaining the cold chain. An insulating effect of containers is typically achieved by using foamed polystyrene (Styrofoam). On the one hand, these structures have a very good insulating effect, but on the other hand, they cannot be reduced in volume during recirculation and are problematic with regard to recycling. The aim of the research presented here is therefore to develop a knitted box that is designed as a volume-reducible, rigid but foldable box. This can be used as a supplement to existing transport container systems and therefore can be inserted in the transport container. The knitted box performs as insulation when the transported goods are actively cooled inside the box, which is more sustainable and flexible than recent insulation solutions. Knitted fabrics, especially spacer fabrics, have advantageous thermo-physical properties for this application due to their structural design. In the course of a research project, various spacer fabrics were tested for their thermo-physical suitability as insulation materials. It was found that knitted predetermined folding lines represent an insulation gap. Based on this, a new structure was developed which, due to its structural design, compensates for cold or thermal bridges at vertices and edges of the box. The results show that the knitted corrugated structure insulates better than the knitted spacer fabrics with predetermined folding lines. A thermal imaging camera was used to identify critical points for heat transfer

Ascorbate oxidase: The unexpected involvement of a ‘wasteful enzyme’ in the symbioses with nitrogen-fixing bacteria and arbuscular mycorrhizal fungi

Ascorbate oxidase (AO, EC 1.10.3.3) catalyzes the oxidation of ascorbate (AsA) to yield water. AO overexpressing plants are prone to ozone and salt stresses, whereas lower expression apparently confers resistance to unfavorable environmental conditions. Previous studies have suggested a role for AO as a regulator of oxygen content in photosynthetic tissues. For the first time we show here that the expression of a Lotus japonicus AO gene is induced in the symbiotic interaction with both nitrogen-fixing bacteria and arbuscular mycorrhizal (AM) fungi. In this framework, high AO expression is viewed as a possible strategy to down-regulate oxygen diffusion in root nodules, and a component of AM symbiosis. A general model of AO function in plants is discussed

SOLI – SOLARE LICHTWIESE. Realisierungsstudie für den Bau und Betrieb von Photovoltaikanlagen auf der Lichtwiese

Forschungszeitraum: 5/2006 bis 10/2006. Ziele: Prüfung der räumlichen und organisationstechnischen Möglichkeiten und der Rahmenbedingungen für die Installation von Photovoltaikanlagen auf der Lichtwies

Chemical heterogeneities in tungsten containing TiAl alloys processed by powder metallurgy

International audienceDuring the last decade, it has been shown that the W-containing IRIS-TiAl alloy displays promising properties for structural applications at high temperatures. The manufacturing process of this alloy is divided into three successive steps: electrode production, powder atomisation and spark plasma sintering (SPS) densification. However, an IRIS alloy densified by using pre-alloyed powders atomized by EIGA process (Electrode Induction melting Gas Atomisation) has recently been found to exhibit chemical heterogeneities. The aim of the present work is to look for the origin of such heterogeneities all along this manufacturing process. The microstructures and the chemical compositions of the material obtained after these different steps are thus investigated at intermediate and local scales by using various experimental tools. A particular attention is paid to the distribution of tungsten atoms in correlation to the constituent phases. Effects of these heterogeneities on mechanical properties are measured by performing tensile tests at room and high temperatures. It will be demonstrated that these heterogeneities are issued from tungsten segregation occurring during the first stage of the initial solidification of the electrode, thus prior to atomisation

SOLI – SOLARE LICHTWIESE. Realisierungsstudie für den Bau und Betrieb von Photovoltaikanlagen auf der Lichtwiese

Forschungszeitraum: 5/2006 bis 10/2006. Ziele: Prüfung der räumlichen und organisationstechnischen Möglichkeiten und der Rahmenbedingungen für die Installation von Photovoltaikanlagen auf der Lichtwiese