Utilization of Hemicelluloses as Example for Holistic Recovery of Agricultural Residues

The objective of this work was to separate and characterize the hemicellulose from agricultural residues of annual plants and to achieve a suitable application for it. Therefore, different treatments for producing pulp were tested and compared. Wheat straw and oat husks were digested by alkaline pulping and delignification. Pectin from sugar beet pulp was obtained by acid extraction. Beside the production of pulp, the separation and utilization of hemicellulose as resource was a key aspect of this work. The hemicelluloses were tested as paper additives, flame retardants and flotation agents.     

Observations of Surface Relief of Proeutectoid Widmanstätten Cementite Plates in a Hypereutectoid Carbon Steel

Proeutectoid Widmanstätten cementite in a hypereutectoid carbon steel was found to be associated with a surface relief effect. A hot-stage microscope was used for heat treatment and in situ observation. Widmanstätten cementite plates were obtained near the surface of the specimen. The surface relief effect of Widmanstätten cementite plates was quantitatively characterized by atomic force microscopy. It was found that the relief had either a typical tent shape or apex-lost tent shape. The relief tilt angles were of considerable dispersion, ranging from 20 deg to 50 deg.     

The Activity of Nodules of the Supernodulating Mutant Mtsunn Is not Limited by Photosynthesis under Optimal Growth Conditions

Legumes match the nodule number to the N demand of the plant. When a mutation in the regulatory mechanism deprives the plant of that ability, an excessive number of nodules are formed. These mutants show low productivity in the fields, mainly due to the high carbon burden caused through the necessity to supply numerous nodules. The objective of this study was to clarify whether through optimal conditions for growth and CO₂ assimilation a higher nodule activity of a supernodulating mutant of Medicago truncatula (M. truncatula) can be induced. Several experimental approaches reveal that under the conditions of our experiments, the nitrogen fixation of the supernodulating mutant, designated as sunn (super numeric nodules), was not limited by photosynthesis. Higher specific nitrogen fixation activity could not be induced through short- or long-term increases in CO₂ assimilation around shoots. Furthermore, a whole plant P depletion induced a decline in nitrogen fixation, however this decline did not occur significantly earlier in sunn plants, nor was it more intense compared to the wild-type. However, a distinctly different pattern of nitrogen fixation during the day/night cycles of the experiment indicates that the control of N₂ fixing activity of the large number of nodules is an additional problem for the productivity of supernodulating mutants.     

Key Properties of Ni?Mn?Ga Based Single Crystals Grown with the SLARE Technique

Magnetic shape memory alloys (MSMAs), exhibit large strains and hence are materials, which could substitute giant magnetostrictive and piezoelectrical materials in actuating devices. The actuation stress needed to induce the strain is much lower than in other actuator materials. Since the strain can be induced without phase transformation by a magnetic field, the development of actuators with high working frequencies is possible. However, for reasonable applications, large strains have to be induced with small magnetic fields. Up to now repeatable magnetically induced strains of 5–10% in magnetic fields of less than 500 mT have been achieved only in single crystals. The production of Ni? Mn? Ga based single crystals is difficult and time consuming. The crystal quality is affected by porosity and impurities. With the Bridgeman based method called Slag Remelting and Encapsulation (SLARE) single crystalline ingots of Ni? Mn? Ga, Ni? Mn? Ga? Fe, and Ni? Mn? Ga? Co of high quality were grown and characterized. The results show that MSMA properties depend on the position within the single crystalline rods due to a composition gradient. The influence of surface treatment demonstrates that the decrease of surface roughness leads to a decrease of twinning stress. MSMAs with twinning stresses above 1 MPa show a magnetic field induced strain (MFIS) when tilting is not restricted by constraints. Softer samples can adapt to constraints much better and show large MFIS. Substituting Ni by Fe and Co, shifted the phase transitions successfully to higher temperatures. Ni? Mn? Ga alloyed with up to 6 at.% Co showed three different martensite structures: a non‐modulated tetragonal structure, a modulated tetragonal structure, showing the same behavior as Ni? Mn? Ga with identical structures and a non‐modulated orthorhombic structure with a stress–strain‐behavior explainable by the double twinning mechanism.     

Vision ergonomics at recycling centres

All municipalities in Sweden offer their inhabitants a service for disposing of large-size and hazardous waste at local recycling centres. Opening hours at these centres include hours of darkness. The aims of this study were to 1) describe user and employee experiences of lighting and signs at Swedish recycling centres, 2) measure and assess the lighting system at the two recently built recycling centres in Linköping and to assess the legibility and visibility of the signs used and 3) propose recommendations regarding lighting and signs for recycling centres. Interviews and questionnaires were used to assess experiences of employees and users, and light measurements were performed. By observing users, activities with different visual demands at different areas within the recycling centres were identified. Based on the literature, standards and stakeholder experiences, recommendations regarding lighting systems and sign design, illuminance, luminance and uniformity are proposed for recycling centres.     

Aromatic Phosphonates: A Novel Group of Emitters Showing Blue Ultralong Room Temperature Phosphorescence

In recent years, there has been a growing interest in purely organic materials showing ultralong room-temperature phosphorescence with lifetimes in the range of seconds. Still, the longest known phosphorescence lifetimes are only achieved with crystalline systems so far. Here, a rational design of a completely new family of halogen-free organic luminescent derivatives in amorphous matrices, displaying both conventional fluorescence and phosphorescence is reported. Hydrogen bonding between the newly developed emitters and an ethylene-vinyl alcohol copolymer (Exceval) matrix, which efficiently suppresses vibrational dissipation, enables bright long-lived phosphorescence with lifetimes up to 2.6 s at around 480 nm. The importance of the chosen matrix is shown as well as the implementation in an organic programmable luminescent tag.     

Influence of the length of the internal sleeve valve on the release of powdery substances from the closures of valved bags for dangerous goods

In practice, checks on dangerous goods transports often detect leaks of powdered dangerous goods from valved bags. In this work, the influence factors of a sudden release of powdery substances from the valves of valved bags were investigated. Drop tests were performed on paper bags of UN design type 5M2 with internal sleeve valve using 2 different powdery substances (Esplas H130 and zinc oxide “Rotsiegel”). The internal sleeve valves of all test samples were not sift‐proof with respect to both filling substances. For almost all test samples, the Esplas H130 powder already leaked out of pasted joints during manual filling. This is a contradiction to the requirement in UN 6.1.4.18.1, according to which closures and joints of paper bags 5M2 should be sift‐proof. In the drop tests, longer valve lengths had a greater sealing effect for both filling substances (for filling degrees of at least 95% and for test samples which had already been mechanically loaded). As an extreme example, at the drop height of 1.20 m and a filling degree of 100%, the released amount of zinc oxide powder from a 10‐cm‐long valve was about 16 times higher than from a valve length of 12.5 cm. The valve length is therefore a safety‐relevant parameter and should be specified by the manufacturer. To ensure that only filling goods with similar physical properties in comparison with the test substance are used for valved bags, the user must be informed of the particle size of the test substance.