Substrate effect on the growth of iron clusters in Y zeolite

Investigation of the decomposition process and of the thermolytic products obtained from Fe(CO)5/faujasite adducts by thermogravimetric, IR-spectroscopic, Mössbauer spectroscopic and X-ray absorption measurements (EXAFS) provides evidence for a substrate effect on the growth process of iron clusters. CsY substrate increases the Fe---CO bond strength. The stabilized intermediates generated by this effect upon thermolysis at 500 K are easily oxidized to small iron(III) oxide clusters, whereas with NaY substrate to a large extent iron(O) particles are generated. The latter show Mössbauer effect and EXAFS spectra comparable to those obtained from bulk iron. An inner oxidation process is assumed to be involved in the generation of the zeolite-supported iron oxide

Abrupt Rise of the Longitudinal Recoil Ion Momentum Distribution for Ionizing Collisions

We report on the experimental observation of an abrupt rise in the longitudinal momentum distribution of recoil ions created in proton helium collision. The details of this structure can be related to electrons traveling with the velocity of the projectile [electron capture to the continuum (ECC)]. The longitudinal as well as the transverse distribution of the recoil ions can be explained as a continuation of the momentum distribution from ions resulting from electron capture illustrating the smooth transition from the capture to bound states of the projectile to the ECC.Fil: Weber, Th.. Institut für Kernphysik; AlemaniaFil: Khayyat, Kh.. Institut für Kernphysik; AlemaniaFil: Dörner, R.. Universität Freiburg; AlemaniaFil: Rodríguez Chariarse, Vladimir Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Mergel, V.. Institut für Kernphysik; AlemaniaFil: Jagutzk, O.. Institut für Kernphysik; AlemaniaFil: Schmidt, L.. Institut für Kernphysik,; AlemaniaFil: Müller, K. A.. Institut für Kernphysik; AlemaniaFil: Afaneh, F.. Institut für Kernphysik; AlemaniaFil: Gonzalez, A.. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Schmidt-Böcking, H.. Institut für Kernphysik; Alemani

Evolving Spatially Aggregated Features from Satellite Imagery for Regional Modeling

Satellite imagery and remote sensing provide explanatory variables at relatively high resolutions for modeling geospatial phenomena, yet regional summaries are often desirable for analysis and actionable insight. In this paper, we propose a novel method of inducing spatial aggregations as a component of the machine learning process, yielding regional model features whose construction is driven by model prediction performance rather than prior assumptions. Our results demonstrate that Genetic Programming is particularly well suited to this type of feature construction because it can automatically synthesize appropriate aggregations, as well as better incorporate them into predictive models compared to other regression methods we tested. In our experiments we consider a specific problem instance and real-world dataset relevant to predicting snow properties in high-mountain Asia

Delayed Gastric Emptying in Patients with Prader Willi Syndrome

Background: A 15 year old girl with Prader-Willi Syndrome (PWS) died of gastric rupture. Systematic literature research revealed seven case reports of PWS patients with acute gastric dilatation, two had a lethal course. The objective of this study was to determine if delayed gastric emptying in PWS patients might contribute to gastric dilatation. Methods: Gastric emptying was measured in eight patients with PWS by nucleotid scintigraphy after a standardized test meal. Results: Median age was 17.8 years (range 10.1-19.5). Median BMI of the male patients was 29.5 (range 18.4-34.8), of the female patients 28 (range 20.0-44.8). Half time of gastric emptying was delayed in five of the eight patients (median 78.5 minutes, range 59-134). Conclusion: Scintigraphic measurement of gastric emptying in eight PWS patients revealed delay in comparison to normal values. This might be a risk factor for gastric dilatation and rupture in patients with PW

Comb-calibrated solar spectroscopy through a multiplexed single-mode fiber channel

We investigate a new scheme for astronomical spectrograph calibration using the laser frequency comb at the Solar Vacuum Tower Telescope on Tenerife. Our concept is based upon a single-mode fiber channel, that simultaneously feeds the spectrograph with comb light and sunlight. This yields nearly perfect spatial mode matching between the two sources. In combination with the absolute calibration provided by the frequency comb, this method enables extremely robust and accurate spectroscopic measurements. The performance of this scheme is compared to a sequence of alternating comb and sunlight, and to absorption lines from Earth's atmosphere. We also show how the method can be used for radial-velocity detection by measuring the well-explored 5-minute oscillations averaged over the full solar disk. Our method is currently restricted to solar spectroscopy, but with further evolving fiber-injection techniques it could become an option even for faint astronomical targets.Comment: 21 pages, 11 figures. A video abstract for this paper is available on youtube. For watching the video, please follow https://www.youtube.com/watch?v=oshdZgrt89I . The video abstract is also available for streaming and download on the related article website of New Journal of Physic