SubcriticalWater – a Perspective ReactionMedia for Biomass Processing to Chemicals: Study on Cellulose Conversion as aModel for Biomass

Biomass and water are recognized as a key renewable feedstock in sustainable production of chemicals, fuels and energy. Subcritical water (SubCW), or commonly referred as hot compressed water (HCW), is the water above boiling and below critical point (CP; 374 °C, 22.1 MPa). It has gained great attention in the last few decades as a green, cheap, and nontoxic reagent for conversion of biomass into valuable chemicals. In this paper, hydrothermal reactions of cellulose, as the model biomass substance, with subcritical water at mild temperature and pressure regimes have been studied. The experiments were done in a batch reactor in the temperature range of 220 ° – 300 °C. The main products distributed in liquid, gaseous and solid phase were separated and quantified. The conversions to each group of products were found strongly dependent on the temperature and residence time

Young Aphids Avoid Erroneous Dropping when Evading Mammalian Herbivores by Combining Input from Two Sensory Modalities

Mammalian herbivores may incidentally ingest plant-dwelling insects while foraging. Adult pea aphids (Acyrthosiphon pisum) avoid this danger by dropping off their host plant after sensing the herbivore's warm and humid breath and the vibrations it causes while feeding. Aphid nymphs may also drop (to escape insect enemies), but because of their slow movement, have a lower chance of finding a new plant. We compared dropping rates of first-instar nymphs with those of adults, after exposing pea aphids to different combinations of simulated mammalian breath and vibrations. We hypothesized that nymphs would compensate for the greater risk they face on the ground by interpreting more conservatively the mammalian herbivore cues they perceive. Most adults dropped in response to breath alone, but nymphs rarely did so. Breath stimulus accompanied by one concurrent vibrational stimulus, caused a minor rise in adult dropping rates. Adding a second vibration during breath had no additional effect on adults. The nymphs, however, relied on a combination of the two types of stimuli, with a threefold increase in dropping rates when the breath was accompanied by one vibration, and a further doubling of dropping rates when the second vibration was added. The age-specificity of the aphids' herbivore detection mechanism is probably an adaptation to the different cost of dropping for the different age groups. Relying on a combination of stimuli from two sensory modalities enables the vulnerable nymphs to avoid costly mistakes. Our findings emphasize the importance of the direct trophic effect of mammalian herbivory for plant-dwelling insects

Residual activity induced by heavy ions and beam-loss criteria for heavy-ion accelerators

The paper presents results of FLUKA simulations of the residual activity induced by heavy ions in two target configurations representing: (1) a beam pipe of an accelerator and (2) a bulky accelerator structure like a magnet yoke or a coil. The target materials were stainless steel and copper representing the most common construction materials used for basic accelerator components. For these two materials, the inventory of the induced isotopes depends mainly on the target material and much less on the projectile species. Time evolution of the induced activity can be described by means of a generic curve that is independent from the projectile mass. Dependence of the induced residual activity on selected ion beam parameters was studied. The main goal of the study was establishing a scaling law expanding the existing proton beam-loss tolerance to heavy-ion beams. This scaling law enables specifying beam-loss criteria for projectile species from proton up to uranium at energies from 200  MeV/u up to 1  GeV/u

Commissioning of a gantry beamline with rotator at a synchrotron-based ion therapy center

This paper provides an overview of the worldwide first commissioning of a gantry beamline with a rotator at the MedAustron synchrotron-based proton/ion cancer therapy facility in Wiener Neustadt, Austria. The gantry beamline consists of the high energy beam transfer (HEBT) line and the gantry beam transport system. It transports the beam from the synchrotron to the gantry-room isocenter. The HEBT transports the beam from the synchrotron to the gantry entrance, which is the coupling point between the HEBT and the gantry. The rotator is one of the HEBT modules, thus it is an integral part of the gantry beamline. The MedAustron rotator is the worldwide first rotator system used to match slowly extracted asymmetric beams from the synchrotron to the rotating gantry. In this paper, main attention is paid to ion-optical and beam-alignment aspects of the beamline commissioning. A novel orbit-correction and beam-alignment technique has been developed specifically for the beamline with the rotator. While the theoretical concept of the rotator has existed for almost two decades, the MedAustron rotator is the first hardware implementation of this concept all over the world. The presented overview of the beamline commissioning includes a description of the principal technical solutions and main results of the first beam-transport measurements. Since the measured beam size and beam position agree well with theoretical predictions, one can conclude that the proof-of-concept of the rotator-matching has been successfully accomplished