Production and characterization of fully biobased foamed films based on gelatin

The objective of this study was to produce and characterize gelatin foamed films using extrusion. Three “optimum” formulations containing tannic acid, nanoclays (Cloisite Na+), glycerol, water, and gelatin, as well as three “controls” without tannic acid and nanoclays were prepared by calendering. Furthermore, the three “optimum” formulations were produced by extrusion film blowing only, since no stable processing conditions could be obtained for the controls. A complete set of sample characterization was performed, including morphological, mechanical, physical, and thermal properties. The results showed that besides the processing method, the thickness was also controlled by the glycerol and water content, leading to density slightly above unity, with higher values for the optimum materials. The calendered films from the optimum formulations showed overall a higher number of cells and cell density than the controls. Higher elastic moduli and tensile strengths were obtained for the films from the optimum formulations made by either method because of the reinforcing effect of the tannic acid and nanoclays, but this led to lower strain at break. The thermal profiles were similar for all films, with higher stability for the optimum formulations. The results were also explained via chemical interactions between the components as observed by Fourier transform infrared spectroscopy. Overall, the optimum formulations not only produced better foamed films in terms of general properties but were much easier to process by both methods (calendering and blowing).

Green and stable processing of organic light-emitting diodes from aqueous nanodispersions

Robust method to process of OLEDs from water to avoid the use of hazardous solvents.

Oxygen as a Torrefaction Control Parameter

To speed up the torrefaction process in traditional torrefaction reactors, in particular auger reactors, the temperature of the reactor is substantially higher than the required torrefaction process temperature. This is due to the low heat conductivity of biomass. Unfortunately, the off-gas characteristics of biomass are very sensitive in the temperature window of 180-300°C which can cause a thermal runaway situation in which the process temperature exceeds the intended level. Due to this very sensitive temperature dependence of biomass pyrolysis and its accompanying gas production, a potential solution is to inject small amounts of air directly into the torrefaction reactor. It is found experimentally that this air injection can regulate the temperature of the biomass very rapidly compared to traditional temperature regulation by changing the reactor wall temperature. With this new torrefaction temperature control method, thermal runaway situations can be avoided and the temperature of the biomass in the reactor can be regulated better. Experiments with large beech wood samples show that the torrefaction reaction rate and the temperature in the core of the sample depend on the amount of injected air. Since the flow of combustible gasses (torr-gas) originating from the torrefaction process is very sensitive to temperature, the heat production by combusting the torr-gas can be controlled to some extent. This will result in both a more homogeneous torrefied product as well as a more stable processing of varying biomass types in large-scale torrefaction systems.

Data processing pipeline for Herschel HIFI

Context. The HIFI instrument on the Herschel Space Observatory performed over 9100 astronomical observations, almost 900 of which were calibration observations in the course of the nearly four-year Herschel mission. The data from each observation had to be converted from raw telemetry into calibrated products and were included in the Herschel Science Archive. Aims. The HIFI pipeline was designed to provide robust conversion from raw telemetry into calibrated data throughout all phases of the HIFI missions. Pre-launch laboratory testing was supported as were routine mission operations. Methods. A modular software design allowed components to be easily added, removed, amended and/or extended as the understanding of the HIFI data developed during and after mission operations. Results. The HIFI pipeline processed data from all HIFI observing modes within the Herschel automated processing environment as well as within an interactive environment. The same software can be used by the general astronomical community to reprocess any standard HIFI observation. The pipeline also recorded the consistency of processing results and provided automated quality reports. Many pipeline modules were in use since the HIFI pre-launch instrument level testing. Conclusions. Processing in steps facilitated data analysis to discover and address instrument artefacts and uncertainties. The availability of the same pipeline components from pre-launch throughout the mission made for well-understood, tested, and stable processing. A smooth transition from one phase to the next significantly enhanced processing reliability and robustness.

Identification of Stable Processing Parameters in Ti–6Al–4V Alloy from a Wide Temperature Range Across β Transus and a Large Strain Rate Range

The hot workability of Ti–6Al–4V alloy was investigated according to the measured stress–strain data and their derived forms from a series of hot compressions at the temperatures of 1,023–1,323 K and strain rates of 0.01–10 s

A Study of the Mechanism of Electrical Discharge Machining of Particle Reinforced Metal Matrix Composites with Concavo-Convex Electrode

A new concavo-convex electrode has been designed and employed. And an analysis of the electrical discharge machining (EDM) mechanism of a particulate reinforced metal matrix composite with this new electrode was conducted in this study. It was found that EDM with this new electrode can accelerate the debris discharge during machining so that it has a higher MRR compared to the case where a normal electrode was employed. Moreover, by studying the surface craters, it could confirm that discharge craters tend to connect together for the normal electrode. This indicates an abnormal arcing condition. Thus, the wire electrode was easy to be broken. While for the new electrode, separated craters were observed on the machined surface. This means a stable processing condition. The experiment results reveal the processing mechanism of EDM electrical discharge machining of MMCs by employing this new electrode.