The European Radon Mapping Project

There is almost unanimous agreement that indoor radon (Rn) represents a hazard to human health. Large-scale epidemiological studies gave evidence that Rn is the second-most important cause of lung cancer after smoking and that also relatively low Rn concentrations can be detrimental. This has increasingly led to attempts to limit Rn exposure through regulation, mainly building codes. The proposed Euratom Basic Safety Standards (BSS) require Member States to establish Rn action plans aimed at reducing Rn risk, and to set reference values for limiting indoor Rn concentration. In 2006 the JRC started a project on mapping Rn at the European level, in addition and complementary to (but not as a substitute for) national efforts. These maps are part of the European Atlas of Natural Radiation project, which is planned eventually to comprise geographical assessments of all sources of exposure to natural radiation. Started first, a map of indoor Rn is now in an advanced phase, but still incomplete as national Rn surveys are ongoing in a number of European countries. A European map of geogenic Rn, conceptually and technically more complicated, was started in 2008. The main difficulty encountered is heterogeneity of survey designs, measurement and evaluation methods and database semantics and structures. An important part of the work on the Atlas is therefore to harmonize data and methods. We present the current state of Rn maps and discuss some methodological challenges.JRC.E.8 - Nuclear securit

Crystal field analysis of Pm3+^{3+} (4f4)andSm^{f4}) and Sm^{3+}(4 (4^{f5}) and lattice location studies of 147^{147}Nd and 147^{147}Pm in w-AlN

We report a detailed crystal field analysis of Pm3+ and Sm3+ as well as lattice location studies of 147Pm and 147Nd in 2H-aluminum nitride (w-AlN). The isotopes of mass 147 were produced by nuclear fission and implanted at an energy of 60 keV. The decay chain of interest in this work is 147Nd→147Pm→147Sm (stable). Lattice location studies applying the emission channeling technique were carried out using the β− particles and conversion electrons emitted in the radioactive decay of 147Nd→147Pm. The samples were investigated as implanted, and also they were investigated after annealing to temperatures of 873 K as well as 1373 K. The main fraction of about 60% of both 147Pm as well as 147Nd atoms was located on substitutional Al sites in the AlN lattice; the remainder of the ions were located randomly within the AlN lattice. Following radioactive decay of 147Nd, the cathodoluminescence spectra of Pm3+ and Sm3+ were obtained between 500 nm and 1050 nm at sample temperatures between 12 K and 300 K. High-resolution emission spectra, representing intra-4f electron transitions, were analyzed to establish the crystal-field splitting of the energy levels of Sm3+ (4f5) and Pm3+ (4f4) in cationic sites having C3v symmetry in the AlN lattice. Using crystal-field splitting models, we obtained a rms deviation of 6 cm−1 between 31 calculated-to-experimental energy (Stark) levels for Sm3+ in AlN. The results are similar to those reported for Sm3+ implanted into GaN. Using a set of crystal-field splitting parameters Bnm, for Pm3+ derived from the present Sm3+ analysis, we calculated the splitting for the 5F1, 5I4, and 5I5 multiplet manifolds in Pm3+ and obtained good agreement between the calculated and the experimental Stark levels. Temperature-dependent lifetime measurements are also reported for the emitting levels 4F5∕2 (Sm3+) and 5F1 (Pm3+)

Temporal Deconvolution study of Long and Short Gamma-Ray Burst Light curves

The light curves of Gamma-Ray Bursts (GRBs) are believed to result from internal shocks reflecting the activity of the GRB central engine. Their temporal deconvolution can reveal potential differences in the properties of the central engines in the two populations of GRBs which are believed to originate from the deaths of massive stars (long) and from mergers of compact objects (short). We present here the results of the temporal analysis of 42 GRBs detected with the Gamma-ray Burst Monitor onboard the Fermi Gamma-ray Space Telescope. We deconvolved the profiles into pulses, which we fit with lognormal functions. The distributions of the pulse shape parameters and intervals between neighboring pulses are distinct for both burst types and also fit with lognormal functions. We have studied the evolution of these parameters in different energy bands and found that they differ between long and short bursts. We discuss the implications of the differences in the temporal properties of long and short bursts within the framework of the internal shock model for GRB prompt emission.Comment: 38 pages, 11 figure

Time-Resolved Spectroscopy of the 3 Brightest and Hardest Short Gamma-Ray Bursts Observed with the FGST Gamma-Ray Burst Monitor

From July 2008 to October 2009, the Gamma-ray Burst Monitor (GBM) on board the Fermi Gamma-ray Space Telescope (FGST) has detected 320 Gamma-Ray Bursts (GRBs). About 20% of these events are classified as short based on their T90 duration below 2 s. We present here for the first time time-resolved spectroscopy at timescales as short as 2 ms for the three brightest short GRBs observed with GBM. The time-integrated spectra of the events deviate from the Band function, indicating the existence of an additional spectral component, which can be fit by a power-law with index ~-1.5. The time-integrated Epeak values exceed 2 MeV for two of the bursts, and are well above the values observed in the brightest long GRBs. Their Epeak values and their low-energy power-law indices ({\alpha}) confirm that short GRBs are harder than long ones. We find that short GRBs are very similar to long ones, but with light curves contracted in time and with harder spectra stretched towards higher energies. In our time-resolved spectroscopy analysis, we find that the Epeak values range from a few tens of keV up to more than 6 MeV. In general, the hardness evolutions during the bursts follows their flux/intensity variations, similar to long bursts. However, we do not always see the Epeak leading the light-curve rises, and we confirm the zero/short average light-curve spectral lag below 1 MeV, already established for short GRBs. We also find that the time-resolved low-energy power-law indices of the Band function mostly violate the limits imposed by the synchrotron models for both slow and fast electron cooling and may require additional emission processes to explain the data. Finally, we interpreted these observations in the context of the current existing models and emission mechanisms for the prompt emission of GRBs.Comment: 14 pages, 10 figures, 9 tables, Accepted for publication in the Astrophysical Journal September, 23 2010 (Submitted May, 16 2010) Corrections: 1 reference updated, figure 10 captio

First-year Results of Broadband Spectroscopy of the Brightest Fermi-GBM Gamma-Ray Bursts

We present here our results of the temporal and spectral analysis of a sample of 52 bright and hard gamma-ray bursts (GRBs) observed with the Fermi Gamma-ray Burst Monitor (GBM) during its first year of operation (July 2008-July 2009). Our sample was selected from a total of 253 GBM GRBs based on each event peak count rate measured between 0.2 and 40MeV. The final sample comprised 34 long and 18 short GRBs. These numbers show that the GBM sample contains a much larger fraction of short GRBs, than the CGRO/BATSE data set, which we explain as the result of our (different) selection criteria and the improved GBM trigger algorithms, which favor collection of short, bright GRBs over BATSE. A first by-product of our selection methodology is the determination of a detection threshold from the GBM data alone, above which GRBs most likely will be detected in the MeV/GeV range with the Large Area Telescope (LAT) onboard Fermi. This predictor will be very useful for future multiwavelength GRB follow ups with ground and space based observatories. Further we have estimated the burst durations up to 10MeV and for the first time expanded the duration-energy relationship in the GRB light curves to high energies. We confirm that GRB durations decline with energy as a power law with index approximately -0.4, as was found earlier with the BATSE data and we also notice evidence of a possible cutoff or break at higher energies. Finally, we performed time-integrated spectral analysis of all 52 bursts and compared their spectral parameters with those obtained with the larger data sample of the BATSE data. We find that the two parameter data sets are similar and confirm that short GRBs are in general harder than longer ones.Comment: 40 pages, 11 figures, 3 tables, Submitted to Ap

Retrospektive Analyse eines Patientenkollektivs mit infrainguinalen Bypassverschlüssen – Wechselbeziehungen von Bypassmaterial, Ischämiegrad und distalem Anschlusssegment

Hintergrund und Ziele Unter Berücksichtigung des Hintergrundes einer immer älter werdenden Bevölkerung kommt es im Rahmen der Behandlung von Patienten mit peripherer arterieller Verschlusskrankheit immer häufiger zur Notwendigkeit der Behandlung von Patienten mit Bypassverschlüssen und somit auch zu Revisionsoperationen. Das Ziel dieser Studie besteht darin, den weiteren Verlauf von Patienten mit einem infrainguinalen Bypassverschluss zu untersuchen. Patienten und Methoden Für die retrospektive Single-Center-Studie wurden alle Patienten, die im Zeitraum von 2008 bis 2019 aufgrund eines akuten oder chronischen Bypassverschlusses im Universitätsklinikum Erlangen behandelt wurden, betrachtet. Alle perioperativen Daten zur primären Bypassanlage sowie zur Revisionsoperation wurden dokumentiert und statistisch ausgewertet. Ein besonderer Fokus lag dabei auf dem verwendeten Bypassmaterial, dem Ischämiegrad und dem distalen Anschlusssegment. Die Ergebnisse wurden mit der Literatur verglichen und anschließend diskutiert. Ergebnisse und Beobachtungen Insgesamt wurden 158 (102 Männer, 56 Frauen) Patienten mit infrainguinalem Bypassverschluss eingeschlossen. Bei der primären Bypassanlage wurde bei 57 % der Patienten die V. saphena magna als Material verwendet und bei 41,8 % ein Kunststoffbypass. Nach Bypassverschluss trat in 47 % der Fälle eine akute Extremitätenischämie auf, 53 % der Patienten wiesen eine chronische Ischämie auf. Es trat signifikant häufiger eine akute Ischämie auf, wenn synthetisches Material bei der primären Bypassanlage verwendet wurde (p=0,016). Zudem musste die distale Anastomose im Falle einer Revisionsoperation bei Kunststoffbypässen signifikant weiter distal angelegt werden (p=0,014). Schlussfolgerung Diese Studie zeigt, dass der Verschluss eines infrainguinalen Kunststoffbypasses im Vergleich mit Venentransplantaten zu einer signifikant höheren Rate von akuten Ischämien führt. Außerdem musste bei einer Revisionsoperation von Kunststoffbypässen zumeist distaler anastomosiert werden. Beide Aspekte sollten bei der Wahl des Bypassmaterials bereits bei der Primäroperation für Revaskularisationen berücksichtigt werden

Finanzielle Entwicklung junger Wachstumsunternehmen

One of the biggest difficulties for founders of new ventures is to raise capital for their entrepreneurial endeavors. Based on a discussion of several models of firm development, this paper analyses the financing requirements of young growth companies and describes which sources of financing are available to these firms at different stages of their development. Special emphasis is put on venture capital financing, as this form of financing is particularly suited for young firms with a high potential for growth and value generation. A discussion of the challenges which these firms face when they want to control their financial development concludes this paper

Entrepreneurial Marketing

Entrepreneurship is one of the youngest disciplines in the area of business administration. Hence, there is a special need for literature that can be used in teaching and that can serve as a basis for research. This article reviews five textbooks and three research-oriented books on entrepreneurial marketing, which is regarded as one of the key areas of entrepreneurship. As the review shows, there is no textbook that covers all relevant aspects of entrepreneurial marketing in sufficient breadth and depth. Most books are dominated by contents from general marketing, despite the fact that emerging firms face some very specific challenges in their marketing activities. Our review of the research-oriented literature uncovers a need for more detailed studies that address distinct phenomena in entrepreneurial marketing. Thus, this new and vibrant field offers plenty of opportunities to generate important research findings

Detection of a Thermal Spectral Component in the Prompt Emission of GRB 100724B

Observations of GRB 100724B with the Fermi Gamma-Ray Burst Monitor (GBM) find that the spectrum is dominated by the typical Band functional form, which is usually taken to represent a non-thermal emission component, but also includes a statistically highly significant thermal spectral contribution. The simultaneous observation of the thermal and non-thermal components allows us to confidently identify the two emission components. The fact that these seem to vary independently favors the idea that the thermal component is of photospheric origin while the dominant non-thermal emission occurs at larger radii. Our results imply either a very high efficiency for the non-thermal process, or a very small size of the region at the base of the flow, both quite challenging for the standard fireball model. These problems are resolved if the jet is initially highly magnetized and has a substantial Poynting flux.Comment: 6 pages, 3 figures, 1 table, Accepted for publication in the Astrophysical Journal Letters November, 23 2010 (Submitted October, 20 2010