Techno-economic comparison of renewable energy systems using multi-pole system analysis (MPSA)

The recently published method of multi-pole system analysis (MPSA) is used to techno-economically compare two wind-energy converters: offshore wind turbines and the energy ship concept. According to the method, both systems are (i) modeled, (ii) energetically and economically analyzed, (iii) technoeconomically optimized and, finally, (iv) expected uncertainties are calculated and assessed. The results of the method are used to derive the necessary cost reduction of the wind-energy converters to be economically competitive to fossil-fuel-based technologies.The authors would like to thank the Deutsche Forschungsgemeinschaft (DFG) for the financial support in the framework of the Excellence Initiative, Darmstadt Graduate School of Excellence Energy Science and Engineering (GSC 1070)

Unit Root in Unemployment - New Evidence from Nonparametric Tests

We apply range unit-root tests to OECD unemployment rates and compare the results to conventional tests. By simulations, we nd that unemployment is represented adequately by a new nonlinear transformation of a serially-correlated I(1) process.

Quasi-free scattering from relativistic neutron-deficient carbon isotopes

Quasi-free scattering of the neutron-deficient carbon isotopes 10C and 11C has been studied in inverse kinematics at the R3B-LAND setup at the GSI-Helmholtz Centre for Heavy Ion Research. In this experiment, a 40Ar primary beam was incident on a beryllium production target at an energy of 490 AMeV, and the selected reaction residues were then transported through the fragment separator FRS to the experimental area. The incoming beam was identified using the time-of-flight and energy loss, and the incoming angle of the beam was determined from the position on two silicon strip detectors in front of the reaction target. The target area was surrounded by the Crystal Ball NaI array used for gamma- and proton detection and a box consisting of four silicon strip detectors. After passing through the ALADIN magnet, the outgoing fragments were identified and tracked using the position and energy information given by two additional silicon strip detectors, two fiber detectors, and a time-of-flight wall, and protons emitted in-flight were detected by drift chambers. In order to obtain the cross section for quasi-free scattering on hydrogen, a CH2-target and a carbon target were used, and the measurements with the carbon target were used to subtract both the contribution of the carbon and the background in the CH2-measurements. The cross sections obtained with the carbon target for proton and neutron removal from 11C and for neutron removal from 10C are sigma_C=21.6(8) mb, sigma_C=34.8(23) mb, and sigma_C=32.8(39) mb. The work presented here is aimed at a quantitative understanding of spectroscopic factors, which appear to be quenched for deeply bound nuclei. The obtained quasi-free scattering cross sections for the reactions 11C(p,2p)10B, 11C(p,pn)10C, and 10C(p,pn)9C are sigma_H=17.3(8) mb, sigma_H=21.2(20) mb, and sigma_H=19.7(28) mb, respectively. The associated quenching of spectroscopic factors, obtained from comparing the experimental cross sections with theoretical ones from DWIA-calculations is R_s=0.53(2), R_s=0.82(8), and R_s=1,04(15). The momentum distributions for the fragments of all three reactions have been calculated from the measured incoming and outgoing angles and compared to DWIA-calculations. In all three cases there is good agreement between the measured distributions and calculations for a p-shell knockout. The gamma-energy spectra measured in coincidence with 10C and 10B produced in quasi-free scattering reactions indicate a strong population of the low-lying excited states in both cases. The cross section for the reaction 11C(p,p alpha)7Be has been determined to be sigma_H= 5.8(4) mb. Due to the small spatial separation of the decay products of the unbound 9B on the silicon detectors and limited acceptance of the proton drift chambers, no reliable cross section could be determined for the reaction 10C(p,2p)9B. Furthermore, new front-end electronics for double-sided silicon strip detectors have been developed, and initial tests has been completed. The electronics is based on the combination of commercially available readout and triggering ASICs (VA and TA by Gamma-Medica) and ADC (Struck SIS3300) with a customized sequencing module, based on the VUPROM module developed at GSI. The design is flexible, and it is supposed to be used for DSSD prototype detectors built in connection with the ongoing detector development for nuclear structure experiments at the planned FAIR facility

Shock-wave therapy of gastric outlet syndrome caused by a gallstone

A patient with gastric outlet syndrome (Bouveret's syndrome) caused by a large gallstone impacted in the duodenal bulb was successfully treated by extracorporeal shock-wave lithotripsy. Thus, open abdominal surgery could be avoided. For disintegration of the stone, three consecutive lithotripsy procedures were necessary. Thereafter, stone fragments could be extracted endoscopically. Extracorporeal shock-wave lithotripsy could become a non-surgical alternative in patients with obstruction of the duodenum caused by a gallstone

Scaling and balancing carbon dioxide fluxes in a heterogeneous tundra ecosystem of the Lena River Delta

The current assessments of the carbon turnover in the Arctic tundra are subject to large uncertainties. This problem can (inter alia) be ascribed to both the general shortage of flux data from the vast and sparsely inhabited Arctic region, as well as the typically high spatiotemporal variability of carbon fluxes in tundra ecosystems. Addressing these challenges, carbon dioxide fluxes on an active flood plain situated in the Siberian Lena River Delta were studied during two growing seasons with the eddy covariance method. The footprint exhibited a heterogeneous surface, which generated mixed flux signals that could be partitioned in such a way that both respiratory loss and photosynthetic gain were obtained for each of two vegetation classes. This downscaling of the observed fluxes revealed a differing seasonality in the net uptake of bushes (−0.89 µmol m−2 s−1) and sedges (−0.38 µmol mm−2 s−1) in 2014. That discrepancy, which was concealed in the net signal, resulted from a comparatively warm spring in conjunction with an early snowmelt and a varying canopy structure. Thus, the representativeness of footprints may adversely be affected in response to prolonged unusual weather conditions. In 2015, when air temperatures on average corresponded to climatological means, both vegetation-class-specific flux rates were of similar magnitude (−0.69 µmol m−2 s−1). A comprehensive set of measures (e.g. phenocam) corroborated the reliability of the partitioned fluxes and hence confirmed the utility of flux decomposition for enhanced flux data analysis. This scrutiny encompassed insights into both the phenological dynamic of individual vegetation classes and their respective functional flux to flux driver relationships with the aid of ecophysiologically interpretable parameters. For comparison with other sites, the decomposed fluxes were employed in a vegetation class area-weighted upscaling that was based on a classified high-resolution orthomosaic of the flood plain. In this way, robust budgets that take the heterogeneous surface characteristics into account were estimated. In relation to the average sink strength of various Arctic flux sites, the flood plain constitutes a distinctly stronger carbon dioxide sink. Roughly 42 % of this net uptake, however, was on average offset by methane emissions lowering the sink strength for greenhouse gases. With growing concern about rising greenhouse gas emissions in high-latitude regions, providing robust carbon budgets from tundra ecosystems is critical in view of accelerating permafrost thaw, which can impact the global climate for centuries

Tabulation and summary of thermodynamic effects data for developed cavitation on ogive-nosed bodies

Thermodynamic effects data for developed cavitation on zero and quarter caliber ogives in Freon 113 and water are tabulated and summarized. These data include temperature depression (delta T), flow coefficient (C sub Q), and various geometrical characteristics of the cavity. For the delta T tests, the free-stream temperature varied from 35 C to 95 C in Freon 113 and from 60 C to 125 C in water for a velocity range of 19.5 m/sec to 36.6 m/sec. Two correlations of the delta T data by the entrainment method are presented. These correlations involve different combinations of the Nusselt, Reynolds, Froude, Weber, and Peclet numbers and dimensionless cavity length

Correlations by the entrainment theory of thermodynamic effects for developed cavitation in venturis and comparisons with ogive data

A semi-empirical entrainment theory was employed to correlate the measured temperature depression, Delta T, in a developed cavity for a venturi. This theory correlates Delta t in terms of the dimensionless numbers of Nusselt, Reynolds, Froude, Weber and Peclet, and dimensionless cavity length, L/D. These correlations are then compared with similar correlations for zero and quarter caliber ogives. In addition, cavitation number data for both limited and developed cavitation in venturis are presented

Nanotoxicology: a personal perspective

Nanoparticles arise from a wide variety of natural and man-made sources and have a diverse array of biological, chemical, and physical properties. The toxicity of these particles can be roughly divided into two categories: 1) the enhanced delivery of toxic agents 2) toxicity induced the properties of the particle itself. The use of nanoparticles to provide enhanced delivery of chemotherapeutics is presented followed by a discussion of the size-based effects of electron transfer and physical membrane disruption. Copyright © 2009 John Wiley & Sons, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63042/1/27_ftp.pd

Deep learning based pulse shape discrimination for germanium detectors

Experiments searching for rare processes like neutrinoless double beta decay heavily rely on the identification of background events to reduce their background level and increase their sensitivity. We present a novel machine learning based method to recognize one of the most abundant classes of background events in these experiments. By combining a neural network for feature extraction with a smaller classification network, our method can be trained with only a small number of labeled events. To validate our method, we use signals from a broad-energy germanium detector irradiated with a $^{228}$Th gamma source. We find that it matches the performance of state-of-the-art algorithms commonly used for this detector type. However, it requires less tuning and calibration and shows potential to identify certain types of background events missed by other methods.Comment: Published in Eur. Phys. J. C. 9 pages, 10 figures, 3 table