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Sample records for penelope studien fuer

  1. Encephalopathy with status epilepticus during slow sleep: "the Penelope syndrome".

    PubMed

    Tassinari, Carlo A; Cantalupo, Gaetano; Rios-Pohl, Loreto; Giustina, Elvio Della; Rubboli, Guido

    2009-08-01

    ESES (encephalopathy with status epilepticus during sleep) is an epileptic encephalopathy with heterogeneous clinical manifestations (cognitive, motor, and behavioral disturbances in different associations, and various seizure types) related to a peculiar electroencephalography (EEG) pattern characterized by paroxysmal activity significantly activated during slow sleep-that is, a condition of continuous spikes and waves, or status epilepticus, during sleep. The pathophysiologic mechanisms underlying this condition are still incompletely understood; recent data suggest that the abnormal epileptic EEG activity occurring during sleep might cause the typical clinical symptoms by interfering with sleep-related physiologic functions, and possibly neuroplasticity processes mediating higher cortical functions such as learning and memory consolidation. As in the myth of Penelope, the wife of Odysseus, what is weaved during the day will be unraveled during the night.

  2. Eukaryotic Penelope-Like Retroelements Encode Hammerhead Ribozyme Motifs

    PubMed Central

    Cervera, Amelia; De la Peña, Marcos

    2014-01-01

    Small self-cleaving RNAs, such as the paradigmatic Hammerhead ribozyme (HHR), have been recently found widespread in DNA genomes across all kingdoms of life. In this work, we found that new HHR variants are preserved in the ancient family of Penelope-like elements (PLEs), a group of eukaryotic retrotransposons regarded as exceptional for encoding telomerase-like retrotranscriptases and spliceosomal introns. Our bioinformatic analysis revealed not only the presence of minimalist HHRs in the two flanking repeats of PLEs but also their massive and widespread occurrence in metazoan genomes. The architecture of these ribozymes indicates that they may work as dimers, although their low self-cleavage activity in vitro suggests the requirement of other factors in vivo. In plants, however, PLEs show canonical HHRs, whereas fungi and protist PLEs encode ribozyme variants with a stable active conformation as monomers. Overall, our data confirm the connection of self-cleaving RNAs with eukaryotic retroelements and unveil these motifs as a significant fraction of the encoded information in eukaryotic genomes. PMID:25135949

  3. Monte Carlo simulation of electron beams from an accelerator head using PENELOPE

    NASA Astrophysics Data System (ADS)

    Sempau, J.; Sánchez-Reyes, A.; Salvat, F.; Oulad ben Tahar, H.; Jiang, S. B.; Fernández-Varea, J. M.

    2001-04-01

    The Monte Carlo code PENELOPE has been used to simulate electron beams from a Siemens Mevatron KDS linac with nominal energies of 6, 12 and 18 MeV. Owing to its accuracy, which stems from that of the underlying physical interaction models, PENELOPE is suitable for simulating problems of interest to the medical physics community. It includes a geometry package that allows the definition of complex quadric geometries, such as those of irradiation instruments, in a straightforward manner. Dose distributions in water simulated with PENELOPE agree well with experimental measurements using a silicon detector and a monitoring ionization chamber. Insertion of a lead slab in the incident beam at the surface of the water phantom produces sharp variations in the dose distributions, which are correctly reproduced by the simulation code. Results from PENELOPE are also compared with those of equivalent simulations with the EGS4-based user codes BEAM and DOSXYZ. Angular and energy distributions of electrons and photons in the phase-space plane (at the downstream end of the applicator) obtained from both simulation codes are similar, although significant differences do appear in some cases. These differences, however, are shown to have a negligible effect on the calculated dose distributions. Various practical aspects of the simulations, such as the calculation of statistical uncertainties and the effect of the `latent' variance in the phase-space file, are discussed in detail.

  4. penORNL: a parallel Monte Carlo photon and electron transport package using PENELOPE

    SciTech Connect

    Bekar, Kursat B.; Miller, Thomas Martin; Patton, Bruce W.; Weber, Charles F.

    2015-01-01

    The parallel Monte Carlo photon and electron transport code package penORNL was developed at Oak Ridge National Laboratory to enable advanced scanning electron microscope (SEM) simulations on high-performance computing systems. This paper discusses the implementations, capabilities and parallel performance of the new code package. penORNL uses PENELOPE for its physics calculations and provides all available PENELOPE features to the users, as well as some new features including source definitions specifically developed for SEM simulations, a pulse-height tally capability for detailed simulations of gamma and x-ray detectors, and a modified interaction forcing mechanism to enable accurate energy deposition calculations. The parallel performance of penORNL was extensively tested with several model problems, and very good linear parallel scaling was observed with up to 512 processors. penORNL, along with its new features, will be available for SEM simulations upon completion of the new pulse-height tally implementation.

  5. Self-triggering readout system for the neutron lifetime experiment PENeLOPE

    NASA Astrophysics Data System (ADS)

    Gaisbauer, D.; Konorov, I.; Steffen, D.; Paul, S.

    2016-07-01

    The aim of PENeLOPE (Precision Experiment on Neutron Lifetime Operating with Proton Extraction) at the Forschungsreaktor München II is a high-precision measurement of the neutron lifetime and thereby an improvement of the parameter's precision by one order of magnitude. In order to achieve a higher accuracy, modern experiments naturally require state-of-the-art readout electronics, as well as high-performance data acquisition systems. This paper presents the self-triggering readout system designed for PENeLOPE which features a continuous pedestal tracking, configurable signal detection logic, floating ground up to 30 kV, cryogenic environment and the novel Switched Enabling Protocol (SEP). The SEP is a time-division multiplexing transport level protocol developed for a star network topology.

  6. An investigation on the capabilities of the PENELOPE MC code in nanodosimetry

    SciTech Connect

    Bernal, M. A.; Liendo, J. A.

    2009-02-15

    The Monte Carlo (MC) method has been widely implemented in studies of radiation effects on human genetic material. Most of these works have used specific-purpose MC codes to simulate radiation transport in condensed media. PENELOPE is one of the general-purpose MC codes that has been used in many applications related to radiation dosimetry. Based on the fact that PENELOPE can carry out event-by-event coupled electron-photon transport simulations following these particles down to energies of the order of few tens of eV, we have decided to investigate the capacities of this code in the field of nanodosimetry. Single and double strand break probabilities due to the direct impact of {gamma} rays originated from Co{sup 60} and Cs{sup 137} isotopes and characteristic x-rays, from Al and C K-shells, have been determined by use of PENELOPE. Indirect damage has not been accounted for in this study. A human genetic material geometrical model has been developed, taking into account five organizational levels. In an article by Friedland et al. [Radiat. Environ. Biophys. 38, 39-47 (1999)], a specific-purpose MC code and a very sophisticated DNA geometrical model were used. We have chosen that work as a reference to compare our results. Single and double strand-break probabilities obtained here underestimate those reported by Friedland and co-workers by 20%-76% and 50%-60%, respectively. However, we obtain RBE values for Cs{sup 137}, Al{sub K} and C{sub K} radiations in agreement with those reported in previous works [Radiat. Environ. Biophys. 38, 39-47 (1999)] and [Phys. Med. Biol. 53, 233-244 (2008)]. Some enhancements can be incorporated into the PENELOPE code to improve its results in the nanodosimetry field.

  7. X-ray simulation with the Monte Carlo code PENELOPE. Application to Quality Control.

    PubMed

    Pozuelo, F; Gallardo, S; Querol, A; Verdú, G; Ródenas, J

    2012-01-01

    A realistic knowledge of the energy spectrum is very important in Quality Control (QC) of X-ray tubes in order to reduce dose to patients. However, due to the implicit difficulties to measure the X-ray spectrum accurately, it is not normally obtained in routine QC. Instead, some parameters are measured and/or calculated. PENELOPE and MCNP5 codes, based on the Monte Carlo method, can be used as complementary tools to verify parameters measured in QC. These codes allow estimating Bremsstrahlung and characteristic lines from the anode taking into account specific characteristics of equipment. They have been applied to simulate an X-ray spectrum. Results are compared with theoretical IPEM 78 spectrum. A sensitivity analysis has been developed to estimate the influence on simulated spectra of important parameters used in simulation codes. With this analysis it has been obtained that the FORCE factor is the most important parameter in PENELOPE simulations. FORCE factor, which is a variance reduction method, improves the simulation but produces hard increases of computer time. The value of FORCE should be optimized so that a good agreement of simulated and theoretical spectra is reached, but with a reduction of computer time. Quality parameters such as Half Value Layer (HVL) can be obtained with the PENELOPE model developed, but FORCE takes such a high value that computer time is hardly increased. On the other hand, depth dose assessment can be achieved with acceptable results for small values of FORCE.

  8. Comparison between EGSnrc, Geant4, MCNP5 and Penelope for mono-energetic electron beams.

    PubMed

    Archambault, John Paul; Mainegra-Hing, Ernesto

    2015-07-07

    A simple geometry is chosen to highlight similarities and differences of current electron transport algorithms implemented in four Monte Carlo codes commonly used in radiation physics. Energy deposited in a water-filled sphere by mono-energetic electron beams was calculated using EGSnrc, Geant4, MCNP5 and Penelope as the radius of the sphere varied from 0.25 cm to 4.5 cm for beam energies of 0.5 MeV, 1.0 MeV and 5.0 MeV. The calculations were performed in single-scattering mode (where applicable) and in condensed history mode. A good agreement is found for the single-scattering calculations except for the in-air case at 0.5 MeV where differences increase with decreasing radius up to 5% between EGSnrc and Penelope. Differences between results calculated with the default user settings when compared to their own single-scattering modes are under 5% for all codes when the sphere is surrounded by vacuum, however, large differences occur for Geant4, MCNP5 and Penelope when air is introduced around the sphere. Finally, the parameters associated with the multiple scattering algorithms were tuned reducing these differences below 10% for these codes at the expense of increased computation time.

  9. Fish retroposons related to the Penelope element of Drosophila virilis define a new group of retrotransposable elements.

    PubMed

    Volff, J N; Hornung, U; Schartl, M

    2001-06-01

    Poseidon and Neptune are two ancient lineages of retroposons related to the Penelope element from Drosophila virilis. They have been identified in various teleost fish species, including the medakafish (Oryzias latipes), and the pufferfishes Fugu rubripes and Tetraodon nigroviridis, whose genomes are currently being sequenced. Some of these elements are highly reiterated in fish genomes. Penelope-related elements were also identified in blood fluke, shrimp, sea urchin, cichlid fish and frog, showing that they are widespread in animals. Penelope-related retroposons were not detected among sequences from the Drosophila melanogaster and human genome projects, suggesting that they have been lost from certain animal lineages. A sequence encoding a putative Uri (also called GIY-YIG) endonuclease domain was detected downstream from the gene for reverse transcriptase. To the best of our knowledge, this type of endonuclease sequence has previously been identified in group I introns and in genes for prokaryotic excinucleases but not in retrotransposable elements. Penelope-related elements are frequently truncated at their 5' ends and can also be flanked by long terminal repeat-like structures. Phylogenetic analysis of the reverse transcriptase domain failed to assign Penelope-related retroposons to one of the major groups of retroelements. Overall, therefore, the evidence strongly suggests that these sequences represent a new group of retrotransposable elements.

  10. Au Lα x-rays induced by photons from 241Am: Comparison of experimental results and the predictions of PENELOPE.

    PubMed

    Gonzales, D; Requena, S; Williams, S

    2012-01-01

    The results of experiments performed, measuring the Lα x-rays emitted by Au due to excitation by photons of various energies from an (241)Am sample at forward-scattered angles in the range 0° to 65°, are compared to the predictions of the Monte Carlo code, PENELOPE. The experimental data are in good agreement with the predictions of the program. A comparison of the angular distributions of the probability densities (as predicted by the program) related to the Au Lα and Lβ x-rays suggests that PENELOPE does not simulate the phenomena described by Flügge et al. (1972).

  11. Configuration of the electron transport algorithm of PENELOPE to simulate ion chambers.

    PubMed

    Sempau, J; Andreo, P

    2006-07-21

    The stability of the electron transport algorithm implemented in the Monte Carlo code PENELOPE with respect to variations of its step length is analysed in the context of the simulation of ion chambers used in photon and electron dosimetry. More precisely, the degree of violation of the Fano theorem is quantified (to the 0.1% level) as a function of the simulation parameters that determine the step size. To meet the premises of the theorem, we define an infinite graphite phantom with a cavity delimited by two parallel planes (i.e., a slab) and filled with a 'gas' that has the same composition as graphite but a mass density a thousand-fold smaller. The cavity walls and the gas have identical cross sections, including the density effect associated with inelastic collisions. Electrons with initial kinetic energies equal to 0.01, 0.1, 1, 10 or 20 MeV are generated in the wall and in the gas with a uniform intensity per unit mass. Two configurations, motivated by the design of pancake- and thimble-type chambers, are considered, namely, with the initial direction of emission perpendicular or parallel to the gas-wall interface. This version of the Fano test avoids the need of photon regeneration and the calculation of photon energy absorption coefficients, two ingredients that are common to some alternative definitions of equivalent tests. In order to reduce the number of variables in the analysis, a global new simulation parameter, called the speedup parameter (a), is introduced. It is shown that setting a = 0.2, corresponding to values of the usual PENELOPE parameters of C1 = C2 = 0.02 and values of WCC and WCR that depend on the initial and absorption energies, is appropriate for maximum tolerances of the order of 0.2% with respect to an analogue, i.e., interaction-by-interaction, simulation of the same problem. The precise values of WCC and WCR do not seem to be critical to achieve this level of accuracy. The step-size dependence of the absorbed dose is explained in

  12. The web of Penelope. Regulating women's night work: an unfinished job?

    PubMed

    Riva, Michele A; Scordo, Francesco; Turato, Massimo; Messina, Giovanni; Cesana, Giancarlo

    2015-12-01

    Even though unhealthy consequences of night work for women have been evidenced by international scientific literature only in recent years, they were well acknowledged from ancient times. This essay traces the historical evolution of women's health conditions at work, focusing specifically on nocturnal work. Using the legendary web of Penelope of ancient Greek myths as a metaphor, the paper analyses the early limitations of night-work for women in pre-industrial era and the development of a modern international legislation on this issue, aimed at protecting women's health at the beginning of the twentieth century. The reform of national legislations in a gender-neutral manner has recently abolished gender disparities in night-work, but it seems it also reduced women's protection at work.

  13. Dosimetric characterization of an 192Ir brachytherapy source with the Monte Carlo code PENELOPE.

    PubMed

    Casado, Francisco Javier; García-Pareja, Salvador; Cenizo, Elena; Mateo, Beatriz; Bodineau, Coral; Galán, Pedro

    2010-01-01

    Monte Carlo calculations are highly spread and settled practice to calculate brachytherapy sources dosimetric parameters. In this study, recommendations of the AAPM TG-43U1 report have been followed to characterize the Varisource VS2000 (192)Ir high dose rate source, provided by Varian Oncology Systems. In order to obtain dosimetric parameters for this source, Monte Carlo calculations with PENELOPE code have been carried out. TG-43 formalism parameters have been presented, i.e., air kerma strength, dose rate constant, radial dose function and anisotropy function. Besides, a 2D Cartesian coordinates dose rate in water table has been calculated. These quantities are compared to this source reference data, finding results in good agreement with them. The data in the present study complement published data in the next aspects: (i) TG-43U1 recommendations are followed regarding to phantom ambient conditions and to uncertainty analysis, including statistical (type A) and systematic (type B) contributions; (ii) PENELOPE code is benchmarked for this source; (iii) Monte Carlo calculation methodology differs from that usually published in the way to estimate absorbed dose, leaving out the track-length estimator; (iv) the results of the present work comply with the most recent AAPM and ESTRO physics committee recommendations about Monte Carlo techniques, in regards to dose rate uncertainty values and established differences between our results and reference data. The results stated in this paper provide a complete parameter collection, which can be used for dosimetric calculations as well as a means of comparison with other datasets from this source.

  14. Using Penelope to assess the correctness of NASA Ada software: A demonstration of formal methods as a counterpart to testing

    NASA Technical Reports Server (NTRS)

    Eichenlaub, Carl T.; Harper, C. Douglas; Hird, Geoffrey

    1993-01-01

    Life-critical applications warrant a higher level of software reliability than has yet been achieved. Since it is not certain that traditional methods alone can provide the required ultra reliability, new methods should be examined as supplements or replacements. This paper describes a mathematical counterpart to the traditional process of empirical testing. ORA's Penelope verification system is demonstrated as a tool for evaluating the correctness of Ada software. Grady Booch's Ada calendar utility package, obtained through NASA, was specified in the Larch/Ada language. Formal verification in the Penelope environment established that many of the package's subprograms met their specifications. In other subprograms, failed attempts at verification revealed several errors that had escaped detection by testing.

  15. Monte Carlo Simulation of Secondary Fluorescence using a New Graphical Interface for PENELOPE

    NASA Astrophysics Data System (ADS)

    Pinard, P. T.; Demers, H.; Llovet, X.; Gauvin, R.; Salvat, F.

    2011-12-01

    Secondary fluorescence is not a negligible factor in the chemical concentration measurement of many minerals (quartz, olivine, etc.) using the electron probe microanalysis (EPMA) technique (Llovet and Galán, 2003). The importance of this phenomenon depends on the chemical species present in the mineral but also, in case of heterogeneous samples, on their relative location to the measurement position. Monte Carlo codes are useful tools to select the optimal measurement conditions as well as to correct afterwards the results for phenomenon such as secondary fluorescence. PENELOPE (Salvat et al., 2011) is a Fortran Monte Carlo code for simulation of coupled electron-photon transport in matter that allows a detailed interpretation of experimental results of electron spectroscopy and microscopy. PENEPMA is a dedicated main program of PENELOPE designed to perform simulations with the same parameters as in actual EPMA measurements. Complex geometries can be defined to emulate the internal structure of a sample. Photon interactions are simulated in chronological succession, therefore allowing the calculation of secondary fluorescence. These features combined with the use of the most reliable physical interaction models make PENEPMA a unique Monte Carlo code for EPMA analysis. However, the original version of PENEPMA had a steep learning curve as it required the user to manually create several input files to run a single simulation. To facilitate the use of the code, a graphical interface was recently developed. Written in the cross-platform programming language Python, it simplifies the setup of simulations and the analysis of the results. It also includes optimized simulation parameters which increases the efficiency of the simulations (i.e. reduces the computation time) by a factor of up to 8. In this communication, we describe the structure and capabilities of this graphical interface. It not only eases the definition of the problem, but also provides more extensive

  16. Extension of PENELOPE to protons: Simulation of nuclear reactions and benchmark with Geant4

    SciTech Connect

    Sterpin, E.; Sorriaux, J.; Vynckier, S.

    2013-11-15

    Purpose: Describing the implementation of nuclear reactions in the extension of the Monte Carlo code (MC) PENELOPE to protons (PENH) and benchmarking with Geant4.Methods: PENH is based on mixed-simulation mechanics for both elastic and inelastic electromagnetic collisions (EM). The adopted differential cross sections for EM elastic collisions are calculated using the eikonal approximation with the Dirac–Hartree–Fock–Slater atomic potential. Cross sections for EM inelastic collisions are computed within the relativistic Born approximation, using the Sternheimer–Liljequist model of the generalized oscillator strength. Nuclear elastic and inelastic collisions were simulated using explicitly the scattering analysis interactive dialin database for {sup 1}H and ICRU 63 data for {sup 12}C, {sup 14}N, {sup 16}O, {sup 31}P, and {sup 40}Ca. Secondary protons, alphas, and deuterons were all simulated as protons, with the energy adapted to ensure consistent range. Prompt gamma emission can also be simulated upon user request. Simulations were performed in a water phantom with nuclear interactions switched off or on and integral depth–dose distributions were compared. Binary-cascade and precompound models were used for Geant4. Initial energies of 100 and 250 MeV were considered. For cases with no nuclear interactions simulated, additional simulations in a water phantom with tight resolution (1 mm in all directions) were performed with FLUKA. Finally, integral depth–dose distributions for a 250 MeV energy were computed with Geant4 and PENH in a homogeneous phantom with, first, ICRU striated muscle and, second, ICRU compact bone.Results: For simulations with EM collisions only, integral depth–dose distributions were within 1%/1 mm for doses higher than 10% of the Bragg-peak dose. For central-axis depth–dose and lateral profiles in a phantom with tight resolution, there are significant deviations between Geant4 and PENH (up to 60%/1 cm for depth

  17. A simplified model of the source channel of the Leksell GammaKnife tested with PENELOPE.

    PubMed

    Al-Dweri, Feras M O; Lallena, Antonio M; Vilches, Manuel

    2004-06-21

    Monte Carlo simulations using the code PENELOPE have been performed to test a simplified model of the source channel geometry of the Leksell GammaKnife. The characteristics of the radiation passing through the treatment helmets are analysed in detail. We have found that only primary particles emitted from the source with polar angles smaller than 3 degrees with respect to the beam axis are relevant for the dosimetry of the Gamma Knife. The photon trajectories reaching the output helmet collimators at (x, v, z = 236 mm) show strong correlations between rho = (x2 + y2)(1/2) and their polar angle theta, on one side, and between tan(-1)(y/x) and their azimuthal angle phi, on the other. This enables us to propose a simplified model which treats the full source channel as a mathematical collimator. This simplified model produces doses in good agreement with those found for the full geometry. In the region of maximal dose, the relative differences between both calculations are within 3%, for the 18 and 14 mm helmets, and 10%, for the 8 and 4 mm ones. Besides, the simplified model permits a strong reduction (larger than a factor 15) in the computational time.

  18. The complexities of female aging: Four women protagonists in Penelope Lively's novels.

    PubMed

    Oró-Piqueras, Maricel

    2016-01-01

    Penelope Lively is a well-known contemporary British author who has published a good number of novels and short stories since she started her literary career in her late thirties. In her novels, Lively looks at the lives of contemporary characters moulded by specific historical as well as cultural circumstances. Four of her novels, published from 1987 to 2004, present middle-aged and older women as their main protagonists. Through the voices and thoughts of these female characters, the reader is presented with a multiplicity of realities in which women find themselves after their mid-fifties within a contemporary context. Being a woman and entering into old age is a double-sided jeopardy which has increasingly been present in contemporary fiction. Scholars such as Simone de Beauvoir (1949) and Susan Sontag (1972) were among the first to point out a "double standard of aging" when they assured that women were punished when showing external signs of aging much sooner than men. In Lively's four novels, the aging protagonists present their own stories and, through them, as well as through the voices of those around them, the reader is invited to go beyond the aging appearance of the female protagonists while challenging the limiting conceptions attached to the old body and, by extension, to the social and cultural overtones associated with old age.

  19. An Ancient Transkingdom Horizontal Transfer of Penelope-Like Retroelements from Arthropods to Conifers.

    PubMed

    Lin, Xuan; Faridi, Nurul; Casola, Claudio

    2016-05-02

    Comparative genomics analyses empowered by the wealth of sequenced genomes have revealed numerous instances of horizontal DNA transfers between distantly related species. In eukaryotes, repetitive DNA sequences known as transposable elements (TEs) are especially prone to move across species boundaries. Such horizontal transposon transfers, or HTTs, are relatively common within major eukaryotic kingdoms, including animals, plants, and fungi, while rarely occurring across these kingdoms. Here, we describe the first case of HTT from animals to plants, involving TEs known as Penelope-like elements, or PLEs, a group of retrotransposons closely related to eukaryotic telomerases. Using a combination of in situ hybridization on chromosomes, polymerase chain reaction experiments, and computational analyses we show that the predominant PLE lineage, EN(+)PLEs, is highly diversified in loblolly pine and other conifers, but appears to be absent in other gymnosperms. Phylogenetic analyses of both protein and DNA sequences reveal that conifers EN(+)PLEs, or Dryads, form a monophyletic group clustering within a clade of primarily arthropod elements. Additionally, no EN(+)PLEs were detected in 1,928 genome assemblies from 1,029 nonmetazoan and nonconifer genomes from 14 major eukaryotic lineages. These findings indicate that Dryads emerged following an ancient horizontal transfer of EN(+)PLEs from arthropods to a common ancestor of conifers approximately 340 Ma. This represents one of the oldest known interspecific transmissions of TEs, and the most conspicuous case of DNA transfer between animals and plants.

  20. An Ancient Transkingdom Horizontal Transfer of Penelope-Like Retroelements from Arthropods to Conifers

    PubMed Central

    Lin, Xuan; Faridi, Nurul; Casola, Claudio

    2016-01-01

    Comparative genomics analyses empowered by the wealth of sequenced genomes have revealed numerous instances of horizontal DNA transfers between distantly related species. In eukaryotes, repetitive DNA sequences known as transposable elements (TEs) are especially prone to move across species boundaries. Such horizontal transposon transfers, or HTTs, are relatively common within major eukaryotic kingdoms, including animals, plants, and fungi, while rarely occurring across these kingdoms. Here, we describe the first case of HTT from animals to plants, involving TEs known as Penelope-like elements, or PLEs, a group of retrotransposons closely related to eukaryotic telomerases. Using a combination of in situ hybridization on chromosomes, polymerase chain reaction experiments, and computational analyses we show that the predominant PLE lineage, EN(+)PLEs, is highly diversified in loblolly pine and other conifers, but appears to be absent in other gymnosperms. Phylogenetic analyses of both protein and DNA sequences reveal that conifers EN(+)PLEs, or Dryads, form a monophyletic group clustering within a clade of primarily arthropod elements. Additionally, no EN(+)PLEs were detected in 1,928 genome assemblies from 1,029 nonmetazoan and nonconifer genomes from 14 major eukaryotic lineages. These findings indicate that Dryads emerged following an ancient horizontal transfer of EN(+)PLEs from arthropods to a common ancestor of conifers approximately 340 Ma. This represents one of the oldest known interspecific transmissions of TEs, and the most conspicuous case of DNA transfer between animals and plants. PMID:27190138

  1. Identification of two Penelope-like elements with different structures and chromosome localization in kuruma shrimp genome.

    PubMed

    Koyama, Takashi; Kondo, Hidehiro; Aoki, Takashi; Hirono, Ikuo

    2013-02-01

    Penelope, originally found as a key element responsible for the hybrid dysgenesis in Drosophila virilis, has been widely conserved throughout eukaryotic genomes. In other organisms, they are often referred to as Penelope-like elements or PLEs. In this study, we found two types of PLEs, designated MjPLE01 and MjPLE02, from kuruma shrimp, Marsupenaeus japonicus. There was no observed nucleotide similarity between MjPLE01 and 02, and both elements differed from each other in terms of their structure; MjPLE02 has a distinctive endonuclease (EN) domain at the C-terminus while MjPLE01 do not. A phylogenetic tree that includes publicly available PLEs and TERTs showed that MjPLE01 and 02 were closely related to Coprina elements, which have been reported as an EN-deficient PLE, and to Penelope-Poseidon group, which possess an EN domain, respectively. Genomic Southern blot analysis using MjPLE01 as a probe showed several multiple bands that differ among individual shrimps. On the other hand, two major identical bands were observed when MjPLE02 was used. Colony hybridization showed co-localization of MjPLE01 and GGTTA repeats, suggesting that MjPLE01 might be prevalent in subtelomeric regions of kuruma shrimp genome. These results suggest that the kuruma shrimp genome has at least two types of PLEs with different domain compositions, phylogenetic positions, and probably chromosomeal localization. Such distinctive types of PLEs in an organism have never been described and hence could be a potential source to understand how multiple PLE types evolved.

  2. New method to perform dosimetric quality control of treatment planning system using PENELOPE Monte Carlo and anatomical digital test objects

    NASA Astrophysics Data System (ADS)

    Benhdech, Yassine; Beaumont, Stéphane; Guédon, Jean-Pierre; Torfeh, Tarraf

    2010-04-01

    In this paper, we deepen the R&D program named DTO-DC (Digital Object Test and Dosimetric Console), which goal is to develop an efficient, accurate and full method to achieve dosimetric quality control (QC) of radiotherapy treatment planning system (TPS). This method is mainly based on Digital Test Objects (DTOs) and on Monte Carlo (MC) simulation using the PENELOPE code [1]. These benchmark simulations can advantageously replace experimental measures typically used as reference for comparison with TPS calculated dose. Indeed, the MC simulations rather than dosimetric measurements allow contemplating QC without tying treatment devices and offer in many situations (i.p. heterogeneous medium, lack of scattering volume...) better accuracy compared to dose measurements with classical dosimetry equipment of a radiation therapy department. Furthermore using MC simulations and DTOs, i.e. a totally numerical QC tools, will also simplify QC implementation, and enable process automation; this allows radiotherapy centers to have a more complete and thorough QC. The program DTO-DC was established primarily on ELEKTA accelerator (photons mode) using non-anatomical DTOs [2]. Today our aim is to complete and apply this program on VARIAN accelerator (photons and electrons mode) using anatomical DTOs. First, we developed, modeled and created three anatomical DTOs in DICOM format: 'Head and Neck', Thorax and Pelvis. We parallelized the PENELOPE code using MPI libraries to accelerate their calculation, we have modeled in PENELOPE geometry Clinac head of Varian Clinac 2100CD (photons mode). Then, to implement this method, we calculated the dose distributions in Pelvis DTO using PENELOPE and ECLIPSE TPS. Finally we compared simulated and calculated dose distributions employing the relative difference proposed by Venselaar [3]. The results of this work demonstrate the feasibility of this method that provides a more accurate and easily achievable QC. Nonetheless, this method, implemented

  3. VoxelMages: a general-purpose graphical interface for designing geometries and processing DICOM images for PENELOPE.

    PubMed

    Giménez-Alventosa, V; Ballester, F; Vijande, J

    2016-12-01

    The design and construction of geometries for Monte Carlo calculations is an error-prone, time-consuming, and complex step in simulations describing particle interactions and transport in the field of medical physics. The software VoxelMages has been developed to help the user in this task. It allows to design complex geometries and to process DICOM image files for simulations with the general-purpose Monte Carlo code PENELOPE in an easy and straightforward way. VoxelMages also allows to import DICOM-RT structure contour information as delivered by a treatment planning system. Its main characteristics, usage and performance benchmarking are described in detail.

  4. A simplified model of the source channel of the Leksell Gamma Knife®: testing multisource configurations with PENELOPE

    NASA Astrophysics Data System (ADS)

    Al-Dweri, Feras M. O.; Lallena, Antonio M.

    2004-08-01

    A simplification of the source channel geometry of the Leksell Gamma Knife® (GK), recently proposed by the authors and checked for a single source configuration (Al-Dweri F M O, Lallena A M and Vilches M 2004 Phys. Med. Biol. 49 2687-703), has been used to calculate the dose distributions along the x, y and z axes in a water phantom with a diameter of 160 mm, for different configurations of the Gamma Knife, including 201, 150 and 102 unplugged sources. The code PENELOPE (v. 2001) has been used to perform the Monte Carlo simulations. In addition, the output factors for the 14, 8 and 4 mm helmets have been calculated. The results found for the dose profiles show a qualitatively good agreement with previous ones obtained with EGS4 and PENELOPE (v. 2000) codes and with the predictions of GammaPlan®. The output factors obtained with our model agree within the statistical uncertainties with those calculated with the same Monte Carlo codes and with those measured with different techniques. Owing to the accuracy of the results obtained and to the reduction in the computational time with respect to full geometry simulations (larger than a factor 15), this simplified model opens the possibility of using Monte Carlo tools for planning purposes in the Gamma Knife®.

  5. Assessment of ionization chamber correction factors in photon beams using a time saving strategy with PENELOPE code.

    PubMed

    Reis, C Q M; Nicolucci, P

    2016-02-01

    The purpose of this study was to investigate Monte Carlo-based perturbation and beam quality correction factors for ionization chambers in photon beams using a saving time strategy with PENELOPE code. Simulations for calculating absorbed doses to water using full spectra of photon beams impinging the whole water phantom and those using a phase-space file previously stored around the point of interest were performed and compared. The widely used NE2571 ionization chamber was modeled with PENELOPE using data from the literature in order to calculate absorbed doses to the air cavity of the chamber. Absorbed doses to water at reference depth were also calculated for providing the perturbation and beam quality correction factors for that chamber in high energy photon beams. Results obtained in this study show that simulations with phase-space files appropriately stored can be up to ten times shorter than using a full spectrum of photon beams in the input-file. Values of kQ and its components for the NE2571 ionization chamber showed good agreement with published values in the literature and are provided with typical statistical uncertainties of 0.2%. Comparisons to kQ values published in current dosimetry protocols such as the AAPM TG-51 and IAEA TRS-398 showed maximum percentage differences of 0.1% and 0.6% respectively. The proposed strategy presented a significant efficiency gain and can be applied for a variety of ionization chambers and clinical photon beams.

  6. Effects of bone- and air-tissue inhomogeneities on the dose distributions of the Leksell Gamma Knife calculated with PENELOPE.

    PubMed

    Al-Dweri, Feras M O; Rojas, E Leticia; Lallena, Antonio M

    2005-12-07

    Monte Carlo simulation with PENELOPE (version 2003) is applied to calculate Leksell Gamma Knife dose distributions for heterogeneous phantoms. The usual spherical water phantom is modified with a spherical bone shell simulating the skull and an air-filled cube simulating the frontal or maxillary sinuses. Different simulations of the 201 source configuration of the Gamma Knife have been carried out with a simplified model of the geometry of the source channel of the Gamma Knife recently tested for both single source and multisource configurations. The dose distributions determined for heterogeneous phantoms including the bone- and/or air-tissue interfaces show non-negligible differences with respect to those calculated for a homogeneous one, mainly when the Gamma Knife isocentre approaches the separation surfaces. Our findings confirm an important underdosage (approximately 10%) nearby the air-tissue interface, in accordance with previous results obtained with the PENELOPE code with a procedure different from ours. On the other hand, the presence of the spherical shell simulating the skull produces a few per cent underdosage at the isocentre wherever it is situated.

  7. A simplified model of the source channel of the Leksell Gamma Knife: testing multisource configurations with PENELOPE.

    PubMed

    Al-Dweri, Feras M O; Lallena, Antonio M

    2004-08-07

    A simplification of the source channel geometry of the Leksell Gamma Knife (GK), recently proposed by the authors and checked for a single source configuration (Al-Dweri F M O, Lallena A M and Vilches M 2004 Phys. Med. Biol. 49 2687-703), has been used to calculate the dose distributions along the x, y and z axes in a water phantom with a diameter of 160 mm, for different configurations of the Gamma Knife, including 201, 150 and 102 unplugged sources. The code PENELOPE (v. 2001) has been used to perform the Monte Carlo simulations. In addition, the output factors for the 14, 8 and 4 mm helmets have been calculated. The results found for the dose profiles show a qualitatively good agreement with previous ones obtained with EGS4 and PENELOPE (v. 2000) codes and with the predictions of GammaPlan. The output factors obtained with our model agree within the statistical uncertainties with those calculated with the same Monte Carlo codes and with those measured with different techniques. Owing to the accuracy of the results obtained and to the reduction in the computational time with respect to full geometry simulations (larger than a factor 15), this simplified model opens the possibility of using Monte Carlo tools for planning purposes in the Gamma Knife.

  8. FLUKA and PENELOPE simulations of 10 keV to 10 MeV photons in LYSO and soft tissue

    NASA Astrophysics Data System (ADS)

    Chin, M. P. W.; Böhlen, T. T.; Fassò, A.; Ferrari, A.; Ortega, P. G.; Sala, P. R.

    2014-02-01

    Monte Carlo simulations of electromagnetic particle interactions and transport by FLUKA and PENELOPE were compared. 10 keV to 10 MeV incident photon beams impinged a LYSO crystal and a soft-tissue phantom. Central-axis as well as off-axis depth doses agreed within 1 s.d.; no systematic under- or over-estimate of the pulse height spectra was observed from 100 keV to 10 MeV for both materials, agreement was within 5%. Simulation of photon and electron transport and interactions at this level of precision and reliability is of significant impact, for instance, on treatment monitoring of hadrontherapy where a code like FLUKA is needed to simulate the full suite of particles and interactions (not just electromagnetic). At the interaction-by-interaction level, apart from known differences in condensed history techniques, two-quanta positron annihilation at rest was found to differ between the two codes. PENELOPE produced a 511 keV sharp line, whereas FLUKA produced visible acolinearity, a feature recently implemented to account for the momentum of shell electrons.

  9. A review of HER2-targeted therapy in breast and ovarian cancer: lessons from antiquity - CLEOPATRA and PENELOPE.

    PubMed

    Hodeib, Melissa; Serna-Gallegos, Tasha; Tewari, Krishnansu S

    2015-01-01

    Although breast and ovarian cancer have notable distinctions, there may exist parallel pathways that can be exploited for therapeutic gain. For example, the therapeutic arena in breast cancer has benefited greatly from available endocrine therapies as well as novel drugs designed to target the HER2 receptor, including trastuzumab, lapatinib, T-DM1 and pertuzumab. CLEOPATRA, a Phase III randomized clinical trial studying pertuzumab in women with HER2-amplified metastatic breast cancer, was practice-changing in 2014. Its counterpart, the Phase III randomized PENELOPE trial, was activated following promising Phase II data and studied pertuzumab in an enriched ovarian cancer patient population with low HER3 mRNA. This review will trace the development of anti-HER2 therapies in breast and ovarian cancer.

  10. A simplified model of the source channel of the Leksell GammaKnife® tested with PENELOPE

    NASA Astrophysics Data System (ADS)

    Al-Dweri, Feras M. O.; Lallena, Antonio M.; Vilches, Manuel

    2004-06-01

    Monte Carlo simulations using the code PENELOPE have been performed to test a simplified model of the source channel geometry of the Leksell GammaKnife®. The characteristics of the radiation passing through the treatment helmets are analysed in detail. We have found that only primary particles emitted from the source with polar angles smaller than 3° with respect to the beam axis are relevant for the dosimetry of the Gamma Knife. The photon trajectories reaching the output helmet collimators at (x, y, z = 236 mm) show strong correlations between rgr = (x2 + y2)1/2 and their polar angle thgr, on one side, and between tan-1(y/x) and their azimuthal angle phgr, on the other. This enables us to propose a simplified model which treats the full source channel as a mathematical collimator. This simplified model produces doses in good agreement with those found for the full geometry. In the region of maximal dose, the relative differences between both calculations are within 3%, for the 18 and 14 mm helmets, and 10%, for the 8 and 4 mm ones. Besides, the simplified model permits a strong reduction (larger than a factor 15) in the computational time.

  11. A comprehensive study on the photon energy response of RadFET dosimeters using the PENELOPE Monte Carlo code

    NASA Astrophysics Data System (ADS)

    Kahraman, A.; Kaya, S.; Jaksic, A.; Yilmaz, E.

    2015-05-01

    Radiation-sensing Field Effect Transistors (RadFETs or MOSFET dosimeters) with SiO2 gate dielectric have found applications in space, radiotherapy clinics, and high-energy physics laboratories. More sensitive RadFETs, which require modifications in device design, including gate dielectric, are being considered for personal dosimetry applications. This paper presents results of a detailed study of the RadFET energy response simulated with PENELOPE Monte Carlo code. Alternative materials to SiO2 were investigated to develop high-efficiency new radiation sensors. Namely, in addition to SiO2, Al2O3 and HfO2 were simulated as gate material and deposited energy amounts in these layers were determined for photon irradiation with energies between 20 keV and 5 MeV. The simulations were performed for capped and uncapped configurations of devices irradiated by point and extended sources, the surface area of which is the same with that of the RadFETs. Energy distributions of transmitted and backscattered photons were estimated using impact detectors to provide information about particle fluxes within the geometrical structures. The absorbed energy values in the RadFETs material zones were recorded. For photons with low and medium energies, the physical processes that affect the absorbed energy values in different gate materials are discussed on the basis of modelling results. The results show that HfO2 is the most promising of the simulated gate materials.

  12. Monte Carlo simulation of the dynamic micro-multileaf collimator of a LINAC Elekta Precise using PENELOPE

    NASA Astrophysics Data System (ADS)

    González, W.; Lallena, A. M.; Alfonso, R.

    2011-06-01

    Micro-multileaf collimators are devices that are added to LINAC heads for stereotactic radiosurgery. In this work, the performance of an Elekta Precise LINAC with a dynamic micro-multileaf collimator manufactured by 3D-line has been studied. Monte Carlo simulations based on PENELOPE code and measurements with three different detectors (PTW Semiflex 31010 chamber, PTW PinPoint 31016 chamber and PTW Diode 60008) have been carried out. Simulations were tuned by reproducing the experimental TPR20, 10 quality index, providing a nice description of both the PDD curve and the transverse profiles at the two depths measured. The geometry of the micro-multileaf collimator was tested by calculating the transmission through it, and it was needed to significantly reduce the leaf separation indicated by the manufacturer to reproduce the experimental results. An approximate simulation in which the transport of the particles traversing the dynamic micro-multileaf collimator was described in a simplified way was analyzed, providing good agreement with the full simulations. With the MC model fixed, output factors for various field sizes were calculated and compared to the experimental ones, obtaining good agreement. Percentage depth doses (PDDs) and transverse profiles at two depths measured with the diode for small fields were well reproduced by the simulation, while the measurements performed with the PinPoint chamber showed differences in the PDDs, at large depths, and transverse profiles, at the penumbra. Monte Carlo simulations and Semiflex and diode measurements, performed for a 7.0 cm × 7.0 cm field, were in nice agreement, while those obtained with the PinPoint chamber showed differences that increased with the depth in water. At the phantom entrance, all measurements showed non-negligible differences that made Monte Carlo a good option to estimate the absorbed dose in this region.

  13. Monte Carlo simulation of the dynamic micro-multileaf collimator of a LINAC Elekta Precise using PENELOPE.

    PubMed

    González, W; Lallena, A M; Alfonso, R

    2011-06-07

    Micro-multileaf collimators are devices that are added to LINAC heads for stereotactic radiosurgery. In this work, the performance of an Elekta Precise LINAC with a dynamic micro-multileaf collimator manufactured by 3D-line has been studied. Monte Carlo simulations based on PENELOPE code and measurements with three different detectors (PTW Semiflex 31010 chamber, PTW PinPoint 31016 chamber and PTW Diode 60008) have been carried out. Simulations were tuned by reproducing the experimental TPR(20, 10) quality index, providing a nice description of both the PDD curve and the transverse profiles at the two depths measured. The geometry of the micro-multileaf collimator was tested by calculating the transmission through it, and it was needed to significantly reduce the leaf separation indicated by the manufacturer to reproduce the experimental results. An approximate simulation in which the transport of the particles traversing the dynamic micro-multileaf collimator was described in a simplified way was analyzed, providing good agreement with the full simulations. With the MC model fixed, output factors for various field sizes were calculated and compared to the experimental ones, obtaining good agreement. Percentage depth doses (PDDs) and transverse profiles at two depths measured with the diode for small fields were well reproduced by the simulation, while the measurements performed with the PinPoint chamber showed differences in the PDDs, at large depths, and transverse profiles, at the penumbra. Monte Carlo simulations and Semiflex and diode measurements, performed for a 7.0 cm × 7.0 cm field, were in nice agreement, while those obtained with the PinPoint chamber showed differences that increased with the depth in water. At the phantom entrance, all measurements showed non-negligible differences that made Monte Carlo a good option to estimate the absorbed dose in this region.

  14. Comparison between MCNP and PENELOPE for the simulation of X-ray spectra in electron microscopy in the keV range

    NASA Astrophysics Data System (ADS)

    Roet, D.; Ceballos, C.; Van Espen, P.

    2006-10-01

    In this paper two Monte Carlo codes, MCNP (version 4C2) and PENELOPE (version 2001), were used in a cluster environment to simulate the X-ray spectra emerging from bombarding pure element bulk targets with mono energetic electrons in the keV range (30 keV). The simulation results were compared to experimental data measured on a JEOL-6300 electron microscope with energy dispersive X-ray detector. The results from both codes were compared amongst each other as to find the best in terms of accuracy, ease of use and speed of the calculations.

  15. PENELOPE-2008 Monte Carlo simulation of gamma exposure induced by ⁶⁰Co and NORM-radionuclides in closed geometries.

    PubMed

    Merk, R; Kröger, H; Edelhäuser-Hornung, L; Hoffmann, B

    2013-12-01

    We present Monte Carlo simulations of the gamma exposure in closed rooms made of steel or concrete and contaminated by ⁶⁰Co or NORM radionuclides. The computer code PENELOPE-2008 (Salvat et al., 2009) was used. Our simulations for ⁶⁰Co suggest considering detailed Monte Carlo simulations in future recommendations on clearance and exemption of materials with low radioactivity. For NORM nuclides our calculations suggest that Monte Carlo simulations are a possible alternative in case a material fails the dose rate criteria by using the RP 112 screening method.

  16. Effects of bone- and air-tissue inhomogeneities on the dose distributions of the Leksell Gamma Knife® calculated with PENELOPE

    NASA Astrophysics Data System (ADS)

    Al-Dweri, Feras M. O.; Rojas, E. Leticia; Lallena, Antonio M.

    2005-12-01

    Monte Carlo simulation with PENELOPE (version 2003) is applied to calculate Leksell Gamma Knife® dose distributions for heterogeneous phantoms. The usual spherical water phantom is modified with a spherical bone shell simulating the skull and an air-filled cube simulating the frontal or maxillary sinuses. Different simulations of the 201 source configuration of the Gamma Knife have been carried out with a simplified model of the geometry of the source channel of the Gamma Knife recently tested for both single source and multisource configurations. The dose distributions determined for heterogeneous phantoms including the bone- and/or air-tissue interfaces show non-negligible differences with respect to those calculated for a homogeneous one, mainly when the Gamma Knife isocentre approaches the separation surfaces. Our findings confirm an important underdosage (~10%) nearby the air-tissue interface, in accordance with previous results obtained with the PENELOPE code with a procedure different from ours. On the other hand, the presence of the spherical shell simulating the skull produces a few per cent underdosage at the isocentre wherever it is situated.

  17. Influence of electrodes on the photon energy deposition in CVD-diamond dosimeters studied with the Monte Carlo code PENELOPE.

    PubMed

    Górka, B; Nilsson, B; Fernández-Varea, J M; Svensson, R; Brahme, A

    2006-08-07

    A new dosimeter, based on chemical vapour deposited (CVD) diamond as the active detector material, is being developed for dosimetry in radiotherapeutic beams. CVD-diamond is a very interesting material, since its atomic composition is close to that of human tissue and in principle it can be designed to introduce negligible perturbations to the radiation field and the dose distribution in the phantom due to its small size. However, non-tissue-equivalent structural components, such as electrodes, wires and encapsulation, need to be carefully selected as they may induce severe fluence perturbation and angular dependence, resulting in erroneous dose readings. By introducing metallic electrodes on the diamond crystals, interface phenomena between high- and low-atomic-number materials are created. Depending on the direction of the radiation field, an increased or decreased detector signal may be obtained. The small dimensions of the CVD-diamond layer and electrodes (around 100 microm and smaller) imply a higher sensitivity to the lack of charged-particle equilibrium and may cause severe interface phenomena. In the present study, we investigate the variation of energy deposition in the diamond detector for different photon-beam qualities, electrode materials and geometric configurations using the Monte Carlo code PENELOPE. The prototype detector was produced from a 50 microm thick CVD-diamond layer with 0.2 microm thick silver electrodes on both sides. The mean absorbed dose to the detector's active volume was modified in the presence of the electrodes by 1.7%, 2.1%, 1.5%, 0.6% and 0.9% for 1.25 MeV monoenergetic photons, a complete (i.e. shielded) (60)Co photon source spectrum and 6, 18 and 50 MV bremsstrahlung spectra, respectively. The shift in mean absorbed dose increases with increasing atomic number and thickness of the electrodes, and diminishes with increasing thickness of the diamond layer. From a dosimetric point of view, graphite would be an almost perfect

  18. 20. HISTORIC VIEW OF THE VEREIN FUER RAUMSCHIFFAHRT, 1930. LEFT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. HISTORIC VIEW OF THE VEREIN FUER RAUMSCHIFFAHRT, 1930. LEFT TO RIGHT: RUDOLF NEBEL, FRANZ RITTER, UNKNOWN, KURT HEINISCH, UNKNOWN, HERMANN OBERTH, UNKNOWN, KLAUS RIEDEL, WERNHER VON BRAUN, UNKNOWN, KLAUS RIEDEL HOLDS EARLY VERSION OR MODEL FOR THE MINIMUM ROCKET, 'MIRAK'. - Marshall Space Flight Center, Redstone Rocket (Missile) Test Stand, Dodd Road, Huntsville, Madison County, AL

  19. Development and implementation in the Monte Carlo code PENELOPE of a new virtual source model for radiotherapy photon beams and portal image calculation

    NASA Astrophysics Data System (ADS)

    Chabert, I.; Barat, E.; Dautremer, T.; Montagu, T.; Agelou, M.; Croc de Suray, A.; Garcia-Hernandez, J. C.; Gempp, S.; Benkreira, M.; de Carlan, L.; Lazaro, D.

    2016-07-01

    This work aims at developing a generic virtual source model (VSM) preserving all existing correlations between variables stored in a Monte Carlo pre-computed phase space (PS) file, for dose calculation and high-resolution portal image prediction. The reference PS file was calculated using the PENELOPE code, after the flattening filter (FF) of an Elekta Synergy 6 MV photon beam. Each particle was represented in a mobile coordinate system by its radial position (r s ) in the PS plane, its energy (E), and its polar and azimuthal angles (φ d and θ d ), describing the particle deviation compared to its initial direction after bremsstrahlung, and the deviation orientation. Three sub-sources were created by sorting out particles according to their last interaction location (target, primary collimator or FF). For each sub-source, 4D correlated-histograms were built by storing E, r s , φ d and θ d values. Five different adaptive binning schemes were studied to construct 4D histograms of the VSMs, to ensure histogram efficient handling as well as an accurate reproduction of E, r s , φ d and θ d distribution details. The five resulting VSMs were then implemented in PENELOPE. Their accuracy was first assessed in the PS plane, by comparing E, r s , φ d and θ d distributions with those obtained from the reference PS file. Second, dose distributions computed in water, using the VSMs and the reference PS file located below the FF, and also after collimation in both water and heterogeneous phantom, were compared using a 1.5%-0 mm and a 2%-0 mm global gamma index, respectively. Finally, portal images were calculated without and with phantoms in the beam. The model was then evaluated using a 1%-0 mm global gamma index. Performance of a mono-source VSM was also investigated and led, as with the multi-source model, to excellent results when combined with an adaptive binning scheme.

  20. Development and implementation in the Monte Carlo code PENELOPE of a new virtual source model for radiotherapy photon beams and portal image calculation.

    PubMed

    Chabert, I; Barat, E; Dautremer, T; Montagu, T; Agelou, M; Croc de Suray, A; Garcia-Hernandez, J C; Gempp, S; Benkreira, M; de Carlan, L; Lazaro, D

    2016-07-21

    This work aims at developing a generic virtual source model (VSM) preserving all existing correlations between variables stored in a Monte Carlo pre-computed phase space (PS) file, for dose calculation and high-resolution portal image prediction. The reference PS file was calculated using the PENELOPE code, after the flattening filter (FF) of an Elekta Synergy 6 MV photon beam. Each particle was represented in a mobile coordinate system by its radial position (r s ) in the PS plane, its energy (E), and its polar and azimuthal angles (φ d and θ d ), describing the particle deviation compared to its initial direction after bremsstrahlung, and the deviation orientation. Three sub-sources were created by sorting out particles according to their last interaction location (target, primary collimator or FF). For each sub-source, 4D correlated-histograms were built by storing E, r s , φ d and θ d values. Five different adaptive binning schemes were studied to construct 4D histograms of the VSMs, to ensure histogram efficient handling as well as an accurate reproduction of E, r s , φ d and θ d distribution details. The five resulting VSMs were then implemented in PENELOPE. Their accuracy was first assessed in the PS plane, by comparing E, r s , φ d and θ d distributions with those obtained from the reference PS file. Second, dose distributions computed in water, using the VSMs and the reference PS file located below the FF, and also after collimation in both water and heterogeneous phantom, were compared using a 1.5%-0 mm and a 2%-0 mm global gamma index, respectively. Finally, portal images were calculated without and with phantoms in the beam. The model was then evaluated using a 1%-0 mm global gamma index. Performance of a mono-source VSM was also investigated and led, as with the multi-source model, to excellent results when combined with an adaptive binning scheme.

  1. The impact of anthropogenic food supply on fruit consumption by dusky-legged guan (Penelope obscura Temminck, 1815): potential effects on seed dispersal in an Atlantic forest area.

    PubMed

    Vasconcellos-Neto, J; Ramos, R R; Pinto, L P

    2015-11-10

    AbstractFrugivorous birds are important seed dispersers and influence the recruitment of many plant species in the rainforest. The efficiency of this dispersal generally depends on environment quality, bird species, richness and diversity of resources, and low levels of anthropogenic disturbance. In this study, we compared the sighting number of dusky-legged guans (Penelope obscura) by km and their movement in two areas of Serra do Japi, one around the administrative base (Base) where birds received anthropogenic food and a pristine area (DAE) with no anthropogenic resource. We also compared the richness of native seeds in feces of birds living in these two areas. Although the abundance of P. obscura was higher in the Base, these individuals moved less, dispersed 80% fewer species of plants and consumed 30% fewer seeds than individuals from DAE. The rarefaction indicated a low richness in the frugivorous diet of birds from the Base when compared to the populations from DAE. We conclude that human food supply can interfere in the behavior of these birds and in the richness of native seeds dispersed.

  2. The impact of anthropogenic food supply on fruit consumption by dusky-legged guan (Penelope obscura Temminck, 1815): potential effects on seed dispersal in an Atlantic forest area.

    PubMed

    Vasconcellos-Neto, J; Ramos, R R; Pinto, L P

    2015-11-01

    Frugivorous birds are important seed dispersers and influence the recruitment of many plant species in the rainforest. The efficiency of this dispersal generally depends on environment quality, bird species, richness and diversity of resources, and low levels of anthropogenic disturbance. In this study, we compared the sighting number of dusky-legged guans (Penelope obscura) by km and their movement in two areas of Serra do Japi, one around the administrative base (Base) where birds received anthropogenic food and a pristine area (DAE) with no anthropogenic resource. We also compared the richness of native seeds in feces of birds living in these two areas. Although the abundance of P. obscura was higher in the Base, these individuals moved less, dispersed 80% fewer species of plants and consumed 30% fewer seeds than individuals from DAE. The rarefaction indicated a low richness in the frugivorous diet of birds from the Base when compared to the populations from DAE. We conclude that human food supply can interfere in the behavior of these birds and in the richness of native seeds dispersed.

  3. SBRT of lung tumours: Monte Carlo simulation with PENELOPE of dose distributions including respiratory motion and comparison with different treatment planning systems

    NASA Astrophysics Data System (ADS)

    Panettieri, Vanessa; Wennberg, Berit; Gagliardi, Giovanna; Amor Duch, Maria; Ginjaume, Mercè; Lax, Ingmar

    2007-07-01

    The purpose of this work was to simulate with the Monte Carlo (MC) code PENELOPE the dose distribution in lung tumours including breathing motion in stereotactic body radiation therapy (SBRT). Two phantoms were modelled to simulate a pentagonal cross section with chestwall (unit density), lung (density 0.3 g cm-3) and two spherical tumours (unit density) of diameters respectively of 2 cm and 5 cm. The phase-space files (PSF) of four different SBRT field sizes of 6 MV from a Varian accelerator were calculated and used as beam sources to obtain both dose profiles and dose-volume histograms (DVHs) in different volumes of interest. Dose distributions were simulated for five beams impinging on the phantom. The simulations were conducted both for the static case and including the influence of respiratory motion. To reproduce the effect of breathing motion different simulations were performed keeping the beam fixed and displacing the phantom geometry in chosen positions in the cranial and caudal and left-right directions. The final result was obtained by combining the different position with two motion patterns. The MC results were compared with those obtained with three commercial treatment planning systems (TPSs), two based on the pencil beam (PB) algorithm, the TMS-HELAX (Nucletron, Sweden) and Eclipse (Varian Medical System, Palo Alto, CA), and one based on the collapsed cone algorithm (CC), Pinnacle3 (Philips). Some calculations were also carried out with the analytical anisotropic algorithm (AAA) in the Eclipse system. All calculations with the TPSs were performed without simulated breathing motion, according to clinical practice. In order to compare all the TPSs and MC an absolute dose calibration in Gy/MU was performed. The analysis shows that the dose (Gy/MU) in the central part of the gross tumour volume (GTV) is calculated for both tumour sizes with an accuracy of 2-3% with PB and CC algorithms, compared to MC. At the periphery of the GTV the TPSs overestimate

  4. SBRT of lung tumours: Monte Carlo simulation with PENELOPE of dose distributions including respiratory motion and comparison with different treatment planning systems.

    PubMed

    Panettieri, Vanessa; Wennberg, Berit; Gagliardi, Giovanna; Duch, Maria Amor; Ginjaume, Mercè; Lax, Ingmar

    2007-07-21

    The purpose of this work was to simulate with the Monte Carlo (MC) code PENELOPE the dose distribution in lung tumours including breathing motion in stereotactic body radiation therapy (SBRT). Two phantoms were modelled to simulate a pentagonal cross section with chestwall (unit density), lung (density 0.3 g cm(-3)) and two spherical tumours (unit density) of diameters respectively of 2 cm and 5 cm. The phase-space files (PSF) of four different SBRT field sizes of 6 MV from a Varian accelerator were calculated and used as beam sources to obtain both dose profiles and dose-volume histograms (DVHs) in different volumes of interest. Dose distributions were simulated for five beams impinging on the phantom. The simulations were conducted both for the static case and including the influence of respiratory motion. To reproduce the effect of breathing motion different simulations were performed keeping the beam fixed and displacing the phantom geometry in chosen positions in the cranial and caudal and left-right directions. The final result was obtained by combining the different position with two motion patterns. The MC results were compared with those obtained with three commercial treatment planning systems (TPSs), two based on the pencil beam (PB) algorithm, the TMS-HELAX (Nucletron, Sweden) and Eclipse (Varian Medical System, Palo Alto, CA), and one based on the collapsed cone algorithm (CC), Pinnacle(3) (Philips). Some calculations were also carried out with the analytical anisotropic algorithm (AAA) in the Eclipse system. All calculations with the TPSs were performed without simulated breathing motion, according to clinical practice. In order to compare all the TPSs and MC an absolute dose calibration in Gy/MU was performed. The analysis shows that the dose (Gy/MU) in the central part of the gross tumour volume (GTV) is calculated for both tumour sizes with an accuracy of 2-3% with PB and CC algorithms, compared to MC. At the periphery of the GTV the TPSs

  5. The Brustkrebs-Studien.de website for breast cancer patients: User acceptance of a German internet portal offering information on the disease and treatment options, and a clinical trials matching service

    PubMed Central

    2010-01-01

    Background The internet portal http://www.brustkrebs-studien.de (BKS) was launched in 2000 by the German Society of Senology (DGS) and the Baden-Württemberg Institute for Women's Health (IFG) to provide expert-written information on breast cancer online and to encourage and facilitate the participation of breast cancer patients in clinical trials. We describe the development of BKS and its applications, and report on website statistics and user acceptance. Methods Existing registries, including ClinicalTrials.gov, were analysed before we designed BKS, which combines a trial registry, a knowledge portal, and an online second opinion service. An advisory board guided the process. Log files and patient enquiries for trial participation and second opinions were analysed. A two-week user satisfaction survey was conducted online. Results During 10/2005-06/2010, the portal attracted 702,655 visitors, generating 15,507,454 page views. By 06/2010, the website's active scientific community consisted of 189 investigators and physicians, and the registry covered 163 clinical trial protocols. In 2009, 143 patients requested trial enrolment and 119 sought second opinions or individual treatment advice from the expert panel. During the two-week survey in 2008, 5,702 BKS visitors submitted 507 evaluable questionnaires. Portal acceptance was high. Respondents trusted information correctness (80%), welcomed self-matching to clinical trials (79%) and planned to use the portal in the future (76%) and recommend it to others (81%). Conclusions BKS is an established and trusted breast cancer information platform offering up-to-date resources and protocols to the growing physician and patient community to encourage participation in clinical trials. Further studies are needed to assess potential increases in trial enrolment by eligibility matching services. PMID:21126358

  6. Investigation of the Performance of Various CVD Diamond Crystal Qualities for the Measurement of Radiation Doses from a Low Energy Mammography X-Ray Beam, Compared with MC Code (PENELOPE) Calculations

    NASA Astrophysics Data System (ADS)

    Zakari, Y. I.; Mavunda, R. D.; Nam, T. L.; Keddy, R. J.

    The tissue equivalence of diamond allows for accurate radiation dose determination without large corrections for different attenuation values in biological tissue, but its low Z value limits this advantage however to the lower energy photons such as for example in Mammography X-ray beams. This paper assays the performance of nine Chemical Vapour Deposition (CVD) diamonds for use as radiation sensing material. The specimens fabricated in wafer form are classified as detector grade, optical grade and single crystals. It is well known that the presence of defects in diamonds, including CVD specimens, not only dictates but also affects the responds of diamond to radiation in different ways. In this investigation, tools such as electron spin resonance (ESR), thermoluminescence (TL) Raman spectroscopy and ultra violet (UV) spectroscopy were used to probe each of the samples. The linearity, sensitivity and other characteristics of the detector to photon interaction was analyzed, and from the I-V characteristics. The diamonds categorized into four each, of the so called Detector and Optical grades, and a single crystal CVD were exposed to low X-ray peak voltage range (22 to 27 KVp) with a trans-crystal polarizing fields of 0.4 kV.cm-1, 0.66 kV.cm-1 and 0.8 kV.cm-1. The presentation discusses the presence of defects identifiable by the techniques used and correlates the radiation performance of the three types of crystals to their presence. The choice of a wafer as either a spectrometer or as X-ray dosimeter within the selected energy range was made. The analyses was validated with Monte-Carlo code (PENELOPE)

  7. Valuing Multiple Critical Approaches: Penelope, Again...and Again.

    ERIC Educational Resources Information Center

    Shull, Ellen

    1992-01-01

    Describes the usefulness of helping students use varied critical stances (including feminism, new historicism, psychoanalytic criticism, and deconstruction) in the teaching of literature. Demonstrates with the "The Odyssey." (SR)

  8. Lifelong Learning: One Focus, Different Systems. Studien zur Erwachsenenbildung, Band 19.

    ERIC Educational Resources Information Center

    Harney, Klaus, Ed.; Heikkinen, Anja, Ed.; Rahn, Sylvia, Ed.; Schemmann, Michael, Ed.

    These 17 articles on different subjects of the broader theme "lifelong learning" represent the latest results of the discussions of the Vocational Education and Culture Research Network. An introduction (Klaus Harney et al.) provides summaries of the contents. The articles are "The Global and International Discourse of Lifelong…

  9. Status and Use of African Lingua Francas. Afrika-Studien Nr. 49.

    ERIC Educational Resources Information Center

    Heine, Bernd

    Defining a lingua franca as a "common language which is habitually used as a medium of communication between groups of people whose mother tongues are different, "this book begins by comparing various Africa lingua francas and discussing questions of general relevance to their study, and then presents statements of varying length about…

  10. Reforms and Innovations in Estonian Education. Baltische Studien zur Erziehungs- und Sozialwissenschaft. Volume 16

    ERIC Educational Resources Information Center

    Mikk, Jaan, Ed.; Veisson, Marika, Ed.; Luik, Piret, Ed.

    2008-01-01

    This collection of papers provides a small overview of educational research in Estonia. The papers in the collection treat school reforms since the renewal of independence in 1991, new approaches to teacher training, the implementation of a child-centred approach in school, the achieving of educational aims and other actual topics in education.…

  11. Vergleichende Ethnographische Studien zu Bildungssystemen: USA, Japan, Deutschland (Comparative Ethnographic Studies on Educational Systems: United States, Japan, Germany).

    ERIC Educational Resources Information Center

    Roeder, Peter Martin

    2001-01-01

    Reviews three qualitative case studies on the educational systems of Japan, the United States, and Germany, conducted as a component of the Third International Mathematics and Science Study (TIMSS). States that the studies provide a basis for understanding the differences in mathematics and science achievement among Japan, Germany, and the United…

  12. Explorations in Social Inequality Stratification Dynamics in Social and Individual Development in Iceland. Studien und Berichte 38.

    ERIC Educational Resources Information Center

    Bjornsson, Sigurjon; And Others

    Having passed through a period of rapid and intense modernization and industrialization in the last two generations, Icelanders still retain the myth of social equality that more properly accompanied the earlier agrarian society. This study looked for evidence of the emergence of stratified social classes and for effects of this class structure in…

  13. Dosimetric characterization of the (60)Co BEBIG Co0.A86 high dose rate brachytherapy source using PENELOPE.

    PubMed

    Guerrero, Rafael; Almansa, Julio F; Torres, Javier; Lallena, Antonio M

    2014-12-01

    (60)Co sources are being used as an alternative to (192)Ir sources in high dose rate brachytherapy treatments. In a recent document from AAPM and ESTRO, a consensus dataset for the (60)Co BEBIG (model Co0.A86) high dose rate source was prepared by using results taken from different publications due to discrepancies observed among them. The aim of the present work is to provide a new calculation of the dosimetric characteristics of that (60)Co source according to the recommendations of the AAPM and ESTRO report. Radial dose function, anisotropy function, air-kerma strength, dose rate constant and absorbed dose rate in water have been calculated and compared to the results of previous works. Simulations using the two different geometries considered by other authors have been carried out and the effect of the cable density and length has been studied.

  14. The Study of Life Review. An Approach to the Investigation of Intellectual Development across the Life Span. Studien und Berichte 47.

    ERIC Educational Resources Information Center

    Staudinger, Ursula M.

    A study looked for age differences in the quality of responses to the Life Review Task (LRT), studied the LRT itself as a tool for exploring wisdom and intellectual functioning in adulthood, and considered personality characteristics and life experience as alternative predictors of response quality. Sixty-three West German women of different ages…

  15. A resolution commemorating the 80th anniversary of the Daughters of Penelope, a preeminent international women's association and affiliate organization of the American Hellenic Educational Progressive Association (AHEPA).

    THOMAS, 111th Congress

    Sen. Snowe, Olympia J. [R-ME

    2009-04-29

    03/26/2010 Resolution agreed to in Senate without amendment and with a preamble by Unanimous Consent. (text: CR S2166) (All Actions) Tracker: This bill has the status Passed SenateHere are the steps for Status of Legislation:

  16. Der Forschungsflughafen und das Institut fuer Luft- und Raumfahrtsysteme

    DTIC Science & Technology

    2007-11-02

    Broitzem: Deutsche Verkehrsfliegerschule Völkenrode: Deutsche Forschungsanstalt für Luftfahrt (DFL) Waggum: Technische Hochschule Grundsteinlegung...Forschungsflughafen Aerodata Deutsches Zentrum für Luft- und Raumfahrt DLR VW Air Services TU Braunschweig Luftfahrt -Bundesamt LBA Deutscher Aeroclub

  17. The Bernhard-Nocht-Institut fuer Schiffs- und Tropenkrankheiten Hamburg,

    DTIC Science & Technology

    PARASITES, *WORMS), (*PROTOZOA, PARASITES), (*PARASITIC DISEASES, TROPICAL REGIONS), DISEASES, FILARIAE, SCHISTOSOMA, INFECTIONS, GASTROPODA, AMOEBA, TRYPANOSOMA, LEISHMANIA, PARASITES, THERAPY, CHEMOTHERAPY , WEST GERMANY

  18. Chemical Research at the Institut fuer Strahlenchemie, Muelheim.

    DTIC Science & Technology

    1981-03-16

    distributed in microorganisms, higher plants, and animals. In plants it is found as the fully phosphorylated derivative, phytic acid . IHP is the...deoxyribonucleic acid olefin radical cation vesicles inositol hexaphosphate (IHP) photochemistry hemoglobin photochemical disinfection of water 20...OF TIS PAGE fMb 21" -. effort of the institute involves the radiation chemistry of deoxyribonucleic acid and model compounds. Described in this report

  19. Work-Study Programs: The Case of 'Berufspraktische Studien' at the Comprehensive University of Kassel. Arbeitspapiere des Wissenschaftlichen Zentrums fur Berufs-und Hochschulforschung an der Gesamthochschule Kassel, Nr. 8.

    ERIC Educational Resources Information Center

    Teichler, Ulrich

    The process of institutionalizing off-campus work experience at the Comprehensive University of Kassel, West Germany, is described. The concepts of the comprehensive university and curricular reform in the Federal Republic of Germany are also addressed. The comprehensive university unites the tasks of research, teaching, and study that previously…

  20. Aspekte und Probleme der linguistischen Analyse schichtenspezifischen Sprachgebrauchs. Studien und Berichte 31 (Aspects and Problems of the Linguistic Analysis of Language Usage Within Specific Social Levels. Studies and Reports No. 31).

    ERIC Educational Resources Information Center

    Klann, Gisela

    This is a study of linguistic variability among social levels in West Germany and of the problems associated with doing such an analysis. The data, ordered according to sex and social levels, were collected from young children retelling narratives heard on tapes. The report represents a comprehensive study of the children's syntactic performance…

  1. Culturally Responsive Education: Diversity in Our Classrooms. Frequently Asked Questions for Saundra Tomlinson-Clarke, Ph.D., and Penelope Lattimer, Ph.D. REL Mid-Atlantic Webinar

    ERIC Educational Resources Information Center

    Regional Educational Laboratory Mid-Atlantic, 2015

    2015-01-01

    The webinar, "Culturally Responsive Education: Diversity in Our Classrooms" focused on the concept of culturally responsive education. Goals of the webinar included: (1) Learning what the research says about effective ways to promote culturally responsive education; (2) Discussion of ways to meet the cultural and linguistic needs of all…

  2. Contemplating a New Model for Air Force Aerospace Medical Technician Skills Sustainment Training

    DTIC Science & Technology

    2006-03-01

    and maintain top-notch clinical skills. Penelope F. Gorsuch , Maj, USAF, NC, 3 October 2005. Posted to IC database. Follow on analysis. 1/16...primary slots on UTCs Penelope F. Gorsuch , Maj, USAF, NC, 3 October 2005. Posted to IC database. Follow on analysis. 1/16/2006 113 It has been...reported on different instances and settings that there were issues with the clinical ability of some reserve nurses. Penelope F. Gorsuch , Maj

  3. Pflanzen als Naehrsubstrat fuer Cryptococcus Neoformans (Plants as a Substratum for Growth of Cryptococcus Neoformans),

    DTIC Science & Technology

    The suitability of plants as a possible substratum for growth (in vitro) of C . neoformans has been investigated. A sample of hay collected from...the second left unsterile. The samples were inoculated by flooding them with suspensions prepared from two known strains of C . neoformans . The...month and subsequently at room temperature. Discrete colonies of C . neoformans appeared after five days on samples of hay as well as of dandelion

  4. The Fringe Reading Facility at the Max-Planck-Institut fuer Stroemungsforschung

    NASA Technical Reports Server (NTRS)

    Becker, F.; Meier, G. E. A.; Wegner, H.; Timm, R.; Wenskus, R.

    1987-01-01

    A Mach-Zehnder interferometer is used for optical flow measurements in a transonic wind tunnel. Holographic interferograms are reconstructed by illumination with a He-Ne-laser and viewed by a video camera through wide angle optics. This setup was used for investigating industrial double exposure holograms of truck tires in order to develop methods of automatic recognition of certain manufacturing faults. Automatic input is achieved by a transient recorder digitizing the output of a TV camera and transferring the digitized data to a PDP11-34. Interest centered around sequences of interferograms showing the interaction of vortices with a profile and subsequent emission of sound generated by this process. The objective is the extraction of quantitative data which relates to the emission of noise.

  5. Une lecon de "Franzoesisch fuer Sie" - Niveau 1 (A Lesson of "French for You," Level 1)

    ERIC Educational Resources Information Center

    Feldhendler, Daniel; And Others

    1974-01-01

    Using as an example Lesson 12 from the text for adults, "Franzoesisch fur Sie" ("French for You") (Huber, Munich), a teaching outline addressed to language learners at the beginners' level is presented. (Text is in German.) (IFS/WGA)

  6. Lesekurse fuer Anfaenger-Fachbereich Psychologie (Reading Courses for Beginners-Psychology)

    ERIC Educational Resources Information Center

    Armaleo-Popper, Lore

    1976-01-01

    Describes a German course for psychologists, given in Italy by the author, using eight original texts by Freud and Mitscherlich. These were assigned for 40-50 hours' continuation reading at home, or were discussed in the 100-120 hours in the classroom. (Text is in German.) (IFS/WGA)

  7. Low Reflection Absorbers for Electromagnetic Waves (Reflexionsarme Absorber Fuer Elektromagnetische Wellen)

    DTIC Science & Technology

    1960-11-01

    should be briefly recalled. They consist of air sound, as a rule, of porous substances, mineral wool , glass wool, and similar substances, whose...nonreflecting room, then small particles of graphite will -17- pi m u . I be inserted into the pores of the porous glass wool or mineral wool . Such wedges

  8. Hoer-Sprech-Uebungen fuer Iraner (Aural-Oral Exercises for Iranians).

    ERIC Educational Resources Information Center

    Scharf, Kurt

    1980-01-01

    Exercises are presented as supplementary material for beginning classes. Many examples illustrate ways to consolidate the learned material, with particular reference to the textbook "Ich lerne Deutsch" and its pictures. Other exercises are designed to compare German and Farsi sentence structure. (IFS/WGA)

  9. Ein Rundfunkkurs fuer Russisch - Klasse 8 (Radio course in Russian, Course 8)

    ERIC Educational Resources Information Center

    Holjewilken, Gudrun

    1974-01-01

    Information is presented regarding the radio course, beginning in the school year 1974-1975, of 9 broadcasts on Lessons 2 through 10 of the textbook: aims, methodological design, topics, action frames, activity of the individual broadcasts. (Text is in German.) (IFS/WGA)

  10. Gesellschaft fuer angewandte Mathematik und Mechanik, Annual Scientific Meeting, Universitaet Regensburg, Regensburg, West Germany, April 16-19, 1984, Proceedings

    NASA Astrophysics Data System (ADS)

    Problems in applied mathematics and mechanics are addressed in reviews and reports. Areas covered are vibration and stability, elastic and plastic mechanics, fluid mechanics, the numerical treatment of differential equations (general theory and finite-element methods in particular), optimization, decision theory, stochastics, actuarial mathematics, applied analysis and mathematical physics, and numerical analysis. Included are major lectures on separated flows, the transition regime of rarefied-gas dynamics, recent results in nonlinear elasticity, fluid-elastic vibration, the new computer arithmetic, and unsteady wave propagation in layered elastic bodies.

  11. Gestaltung und Verwendung von Unterrichtsmittelkomplexen fuer den Russischunterricht (The Designing and Application of Instructional Units for the Teaching of Russian)

    ERIC Educational Resources Information Center

    Guenther, Klaus

    1974-01-01

    Presents bases from school policy and general characteristics of teaching-material units, the main features and elements of each of said units, and the pedagogic-methodological functions of the various parts. Presentation is based on, as an example, the teaching unit "In the department store" (Grade 9). (Text is in German.) (IFS/WGA)

  12. Gesellschaft fuer angewandte Mathematik und Mechanik, Scientific Annual Meeting, Universitaet Dortmund, West Germany, Apr. 1-4, 1986, Reports

    NASA Astrophysics Data System (ADS)

    Various papers on applied mathematics and mechanics are presented. The general topics addressed include: mechanics of fluids; numerical treatment of differential equations; optimization, decision theory, stochastics, and insurance mathematics; applied analysis and mathematical physics; and numerical analysis.

  13. Europeanization of the Hospital Markets - Opportunities and Risks for German Hospitals (Europaeisierung des Krankenhausmarkets - Chancen und Risiken fuer deutsche Krankenhaeuser)

    DTIC Science & Technology

    2004-07-06

    e Peise Dpos𔄁ln G. Neubauer: Einftihrung in die Themnatik 4 . Ausblick* 0 Bdatneut. Phase Konergetzhase oninungspolffische Opbion MIuse Diskussion mm...2180163 4.070 2W,4135 3 .004 0 12 a 4 ,. 4 e sho 426_8_48 1,10C 09M2,95 3 8 C2 -004,13 100 8 3M inovwion 3M HIS - Pan Europische Projekt-Studie Tagungsband...780 1998 1999 200 2001 2002 B SornMischeKH RPsychatmsd*KHGU Polnische Krankenhduser: Bettenkapazitaten sana M W - - 2 3 0 . M6 9 2 21.7 1 3 2 1 4 A W

  14. Renewable Energy Potential for New Mexico

    EPA Pesticide Factsheets

    RE-Powering America's Land: Renewable Energy on Contaminated Land and Mining Sites was presented by Penelope McDaniel, during the 2008 Brown to Green: Make the Connection to Renewable Energy workshop.

  15. Evaluation of PENFAST--a fast Monte Carlo code for dose calculations in photon and electron radiotherapy treatment planning.

    PubMed

    Habib, B; Poumarede, B; Tola, F; Barthe, J

    2010-01-01

    The aim of the present study is to demonstrate the potential of accelerated dose calculations, using the fast Monte Carlo (MC) code referred to as PENFAST, rather than the conventional MC code PENELOPE, without losing accuracy in the computed dose. For this purpose, experimental measurements of dose distributions in homogeneous and inhomogeneous phantoms were compared with simulated results using both PENELOPE and PENFAST. The simulations and experiments were performed using a Saturne 43 linac operated at 12 MV (photons), and at 18 MeV (electrons). Pre-calculated phase space files (PSFs) were used as input data to both the PENELOPE and PENFAST dose simulations. Since depth-dose and dose profile comparisons between simulations and measurements in water were found to be in good agreement (within +/-1% to 1 mm), the PSF calculation is considered to have been validated. In addition, measured dose distributions were compared to simulated results in a set of clinically relevant, inhomogeneous phantoms, consisting of lung and bone heterogeneities in a water tank. In general, the PENFAST results agree to within a 1% to 1 mm difference with those produced by PENELOPE, and to within a 2% to 2 mm difference with measured values. Our study thus provides a pre-clinical validation of the PENFAST code. It also demonstrates that PENFAST provides accurate results for both photon and electron beams, equivalent to those obtained with PENELOPE. CPU time comparisons between both MC codes show that PENFAST is generally about 9-21 times faster than PENELOPE.

  16. Gesellschaft fuer angewandte Mathematik und Mechanik, Scientific Annual Meeting, Universitaet Stuttgart, Federal Republic of Germany, Apr. 13-17, 1987, Reports

    NASA Astrophysics Data System (ADS)

    Recent advances in the analytical and numerical treatment of physical and engineering problems are discussed in reviews and reports. Topics addressed include fluid mechanics, numerical methods for differential equations, FEM approaches, and boundary-element methods. Consideration is given to optimization, decision theory, stochastics, actuarial mathematics, applied mathematics and mathematical physics, and numerical analysis.

  17. Gesellschaft fuer angewandte Mathematik und Mechanik, Scientific Annual Meeting, Universitaet Stuttgart, Federal Republic of Germany, Apr. 13-17, 1987, Reports

    NASA Astrophysics Data System (ADS)

    Recent experimental, theoretical, and numerical investigations of problems in applied mechanics are discussed in reviews and reports. The fields covered include vibration and stability; the mechanics of elastic and plastic materials; fluid mechanics; the numerical treatment of differential equations; finite and boundary elements; optimization, decision theory, stochastics, and actuarial analysis; applied analysis and mathematical physics; and numerical analysis. Reviews are presented on mathematical applications of geometric-optics methods, biomechanics and implant technology, vibration theory in engineering, the stiffness and strength of damaged materials, and the existence of slow steady flows of viscoelastic fluids of integral type.

  18. Zur Frage der Textauswahl in einem Lesekurs fuer die Sozialwissenschaften (On the Question of the Choice of Textbooks in a Course in the Social Sciences)

    ERIC Educational Resources Information Center

    Apelt, Hans-Peter

    1974-01-01

    Passages from three selected samples of textbooks are used to show what requirements are made of textbooks in the social sciences. Some hints are given to the teacher for converting reading suggestions into instructional material. Short texts from Karl Marx are also suggested. (Text is in German.) (IFS/WGA)

  19. Sichere Sprachkenntnisse als Grundlage fuer eine hoehere Qualitaet der Koennensentwicklung.2 (Secure Language Knowledge as a Basis for a Higher Quality of Skill Development. 2)

    ERIC Educational Resources Information Center

    Guenther, Klaus

    1974-01-01

    Topics are: questions regarding intensive learning, awareness of goals and methods as a pre-requisite for effective pupil activity, exposition of typical pupil activity and suggestions for meaningful homework assignments. Examples are given. (Text is in German.) (IFS/WGA)

  20. Sichere Sprachkenntnisse als Grundlage fuer eine hoehere Qualitaet der Koennensentwicklung. 1 (Secure Language Knowledge as a Basis for a Higher Quality of Skill Development. 1)

    ERIC Educational Resources Information Center

    Guenther, Klaus

    1974-01-01

    Topics are: aspects in the systematic acquisition of firm, lasting and ready-to-use knowledge and skill as a basis of instruction; nature of language knowledge; the dialectic of knowledge acquisition and the development of skill; intensive learning; and the design of vocabulary drill units. (Text is in German.) (IFS/WGA)

  1. The Development of Primary Cell Batteries for Torpedoes and Midget Submarine in Germany (Die Entwicklung von Primaerelementbatterien fuer Torpedos und Kleinst-U-Boote in Deutschland),

    DTIC Science & Technology

    1982-10-05

    It was decided to build the Mg-C battery on the principle of the Voltaic pile . Such a battery was fabri- cated by the TVA in which discs with a 400...wakeless torpedo was developed during the First World War by the Siemens Company. There it was their goal initially to produce a remote-controlled torpedo...3 air bottles of 5 1 each (200 atm) 7. Additional air container 8. Removable vertical fins 2 .......................... ....... ;, , At first it was

  2. Ausdruckskraft und Regelmaessigkeit: Was Esperanto fuer automatische Uebersetzung geeignet macht (Expressiveness and Formal Regularity: What Makes Esperanto Suitable for Machine Translation).

    ERIC Educational Resources Information Center

    Schubert, Klaus

    1988-01-01

    Describes DLT, the multilingual machine translation system that uses Esperanto as an intermediate language in which substantial portions of the translation subprocesses are carried out. The criteria for choosing an intermediate language and the reasons for preferring Esperanto over other languages are explained. (Author/DJD)

  3. 25 Jahre - Institut fuer Geodaesie, Teil 1: Wissenschaftliche Beitraege und Berichte (25 Years - Institute of Geodesy, Part 1: Scientific Contributions and Reports)

    DTIC Science & Technology

    2000-01-01

    des Dispersionswinkels zur Bestimmung der Refraktion. AVN 100, S. 51-62, 1993 HAMMING, R., W.: Digitale Filter. VCH-Verlag, Weinheim 1987 HAMPEL, F...KRONMOLLER, H.: Digitale Signalverarbeitung. Springer-Verlag, Berlin 1991 KUHLMANN, H.: Ein Beitrag zur Oberwachung von Briickenbauwerken mit...1987), das Europdische Referenzsystem - EUREF (SEEGER/ALTINER/ENGELHARDT/FRANKE/HABRICH/SCHLC- TER 1998) und das Sistema di Referencia del America del

  4. 25 Jahre - Institut fuer Geodaesie, Teil 2: Forschungsarbeiten und Veroeffentlichungen (25 Years - Institute of Geodesy, Part 2: Research Areas and Publications)

    DTIC Science & Technology

    2000-01-01

    Festpunktfeld Ruanda - 1992 - SIRGAS ( Sistema de refer6ncia geocdntrico para Amdrica del Sur) - 1995 - Festpunktfeld Per6 - 1996 Die DOENAV-Kampagne...Forschungsschwerpunkte Mit dem Sistema di Referdncia Geoc6ntrico para a Amd~rica do Sul (SIRGAS) wurde 1995 in einer Gerneinschaftsaktion aller... digitaler Form gespei- chert werden. Aus demn dabei anfallenden redundanten Datensatz erhalt man im Wege einer Ausgleichung den H6henunterschied

  5. 25 Jahre - Institut fuer Geodaesie, Teil 3: Aus dem Leben des Instituts (25 Years - Institute of Geodesy, Part 3: The Life of the Institute)

    DTIC Science & Technology

    2000-01-01

    seit 1995 Dezernatsleiter fOr digitale Kartographie am Landesvermessungsarnt Thiringen in Erfurt Dipl.-Ing. Chengzu Li * geboren 1946 in Chengdu, VR...UniversitUit Berlin, geleiteten Projekte Dl1, D2 und D6 des DFG-Sonderforschungsbereichs 69 waren Dl: die digitale Bildklassifizierung und -interpretation...Messkampagne bei der Einrichtung eines ganz SUid- amerika Oberdeckenden geodditischen Bezugssystems ( Sistema de Referencia Geocentrico para America del

  6. Ausbildung in der Arbeit mit dem Sprachlabor fuer Lehramtskandidaten der Anglistik. Ein Erfahrungsbericht (Training in Language Laboratory Work for English Teacher Candidates. A Report on an Experience)

    ERIC Educational Resources Information Center

    Gorbahn, Adeline; Wilpert, Klaus

    1975-01-01

    Reports on work at the University of Erlangen beginners' seminar on language laboratory work. This led to production of original laboratory exercises, which were tried out in a Gymnasium class. The aim was to introduce teacher candidates early to problems attending the introduction of language laboratories. (Text is in German.) (IFS/WGA)

  7. Materialien und Modelle fuer den Franzoesischunterricht in der Sekundarstufe Zwei (Materials and Models for Teaching French in Grades 11-13)

    ERIC Educational Resources Information Center

    Frei, Alfons

    1978-01-01

    Texts available for French courses in the highest grades are listed according to topics, which include: position of women, today's youth, the language of advertising, French colonialism, holidays and tourism, modern city living, criminality, French politics. Hints for the teacher are included. (Text is in German.) (IFS/WGA)

  8. Right-Wing Extremism in Germany and the Consequences for the Armed Forces (Rechtsextreme orientierungen in deutschland und ihre folgen fuer die bundeswehr)

    DTIC Science & Technology

    2001-06-01

    religi~ iser Gruppen, von denen naturgemai3 nicht alle den Einsatz fremder Streitkrafte in ihrem Staatsgebiet begrtiffen. Ober die Untergrabung von...Miinster/Westfalen. St~Sss, Richard (1994): Forschungs- und Erklarungsansatze - emn Oberblick. In: Kowalski, Wolfgang ; Schr6der, Wolfgang (Hrsg

  9. Schulgrammatik und Fachgrammatiken: Fuer eine differenzierte Konzeption der didaktischen Grammatik (School Grammar and Scientific Grammar: Toward a Differentiated Concept of Didactic Grammar).

    ERIC Educational Resources Information Center

    Lehmann, Volkmar

    1979-01-01

    Defines the practical functions of various types of grammars, and theoretical functions of linguistic grammars. Points out some differences between the two (stressing contrast between native and foreign languages), as well as differences in defining, finality, or variation of categories, and in psycho- and sociolinguistic components. (IFS/WGA)

  10. Eine aussichtsreiche Lehrmethode fuer fachspezifische Kurse am Ende des zweiten Jahres (A Promising Teaching Method for Content-Area Course at the End of the Second Year).

    ERIC Educational Resources Information Center

    Murti, Kamakshi P.

    1988-01-01

    A course for Business German teaches strategies of textual analysis to develop in the students the reading skills necessary to recognize unfamiliar vocabulary and concepts by using known vocabulary. The course is designed both for students of German without a business background and for business students without knowledge of German. (DJD)

  11. Briefkasten oder Brieftaube? Zur Auswahl der Lexik in amerikanischen Deutschlehrwerken fuer die Grundstufe. ("Mailbox" or "Carrier Pigeon"? Selecting Vocabulary for American College-Level Elementary German Textbooks).

    ERIC Educational Resources Information Center

    Bolton, Sibylle

    A comparison of four college-level elementary German textbooks reveals significant differences in the numbers of vocabulary entries in each textbook. Further comparison of three of the textbooks with the basic German vocabulary lists provided in "Kontaktschwelle Deutsch als Fremdsprache" and in "Das Zertificat Deutsch als Fremdsprache" reveal in…

  12. Comparative Dosimetric Estimates of a 25 keV Electron Micro-beam with three Monte Carlo Codes

    SciTech Connect

    Mainardi, Enrico; Donahue, Richard J.; Blakely, Eleanor A.

    2002-09-11

    The calculations presented compare the different performances of the three Monte Carlo codes PENELOPE-1999, MCNP-4C and PITS, for the evaluation of Dose profiles from a 25 keV electron micro-beam traversing individual cells. The overall model of a cell is a water cylinder equivalent for the three codes but with a different internal scoring geometry: hollow cylinders for PENELOPE and MCNP, whereas spheres are used for the PITS code. A cylindrical cell geometry with scoring volumes with the shape of hollow cylinders was initially selected for PENELOPE and MCNP because of its superior simulation of the actual shape and dimensions of a cell and for its improved computer-time efficiency if compared to spherical internal volumes. Some of the transfer points and energy transfer that constitute a radiation track may actually fall in the space between spheres, that would be outside the spherical scoring volume. This internal geometry, along with the PENELOPE algorithm, drastically reduced the computer time when using this code if comparing with event-by-event Monte Carlo codes like PITS. This preliminary work has been important to address dosimetric estimates at low electron energies. It demonstrates that codes like PENELOPE can be used for Dose evaluation, even with such small geometries and energies involved, which are far below the normal use for which the code was created. Further work (initiated in Summer 2002) is still needed however, to create a user-code for PENELOPE that allows uniform comparison of exact cell geometries, integral volumes and also microdosimetric scoring quantities, a field where track-structure codes like PITS, written for this purpose, are believed to be superior.

  13. Formal specification and verification of Ada software

    NASA Technical Reports Server (NTRS)

    Hird, Geoffrey R.

    1991-01-01

    The use of formal methods in software development achieves levels of quality assurance unobtainable by other means. The Larch approach to specification is described, and the specification of avionics software designed to implement the logic of a flight control system is given as an example. Penelope is described which is an Ada-verification environment. The Penelope user inputs mathematical definitions, Larch-style specifications and Ada code and performs machine-assisted proofs that the code obeys its specifications. As an example, the verification of a binary search function is considered. Emphasis is given to techniques assisting the reuse of a verification effort on modified code.

  14. [Is it beneficial to involve family member? A literature review to psychosocial interventions in family-centered nursing].

    PubMed

    Mahrer-Imhof, Romy; Bruylands, Michelle

    2014-10-01

    Hintergrund: Familien haben Einfluss auf die Gesundheit von chronisch erkrankten Patientinnen und Patienten und werden durch die Krankheit selbst in ihrem Wohlbefinden beeinflusst. Familienmitglieder in die Pflege einzubeziehen, wurde in verschiedenen Studien getestet. Ziel: Das Ziel dieser Literaturübersicht war, randomisiert kontrollierte Studien und Metaanalysen zu familienzentrierten Interventionen (FI) auf die Ergebniskriterien und Effektgrößen der Veränderungen zu untersuchen. Methode: Drei Metaanalysen für den Zeitraum bis 2007 und sechs randomisierte kontrollierte Studien ab 2007 zu psychosozialen familienzentrierten Interventionen wurden eingeschlossen. Ergebnisse: Die Studien zeigten, dass FI kleine bis mittlere positive Effekte auf Depression, psychische Gesundheit, Angst von Patienten und Angehörigen sowie auf die Belastung der Angehörigen hatten. Der Effekt auf physische Gesundheitsparameter konnte nicht gezeigt werden. Die Ergebnisse hingen von der untersuchten Population, den Teilnehmenden an der FI, der Art und dem Zeitraum und der Zeitdauer (Dosis) der FI ab. Die Studien zeigten große Unterschiede in der Länge und Art der Intervention, der Zielpopulation und der Auswahl der Ergebniskriterien sowohl für Patienten als auch für Angehörige. Vergleiche der Ergebnisse sind erschwert durch die Verwendung unterschiedlichster Messinstrumente. Schlussfolgerungen: Weitere Forschung mit verschiedenen Populationen, unterschiedlicher Ausprägung der FI, aber unter Verwendung der gleichen validen Messinstrumente ist anzustreben.

  15. 78 FR 64691 - Endangered and Threatened Wildlife and Plants; Listing Five Foreign Bird Species in Colombia and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-29

    ...We, the U.S. Fish and Wildlife Service (Service), hereby list four Colombian species, the blue-billed curassow (Crax alberti), brown- banded antpitta (Grallaria milleri), Cauca guan (Penelope perspicax), and gorgeted wood-quail (Odontophorus strophium), and one Ecuadorian species, the Esmeraldas woodstar (Chaetocercus berlepschi), as endangered under the Endangered Species Act of 1973 (Act)......

  16. Summary of Research Academic Departments 1992-1993

    DTIC Science & Technology

    1993-10-01

    pedagogical dividends in the ever been used to move industrial machinery was future. seen. Manchester/Bolton was the site where many of Sheffield, a steel...14 August 1992. BOSSHARD, Marianne, Assistant Professor, " Politique (s) et poetique(s) des fluides," Congres BLEDSOE, Penelope M., Associate Professor

  17. Comparisons of Wartime and Peacetime Disease and Non-Battle Injury Rates Aboard Ships of the British Royal Navy

    DTIC Science & Technology

    1991-06-01

    Malaya-- Malaya- Podne-y Rodney Valient Cruisers Crui sers Argonaut KAietiis aAurora Argonaut Berwick Aurora Cleopatra Berwick Enterprise Birmingham...Kenya Cleopatra Maur itius Enterprise Sirius Kenya Sussex Mauritius Orion Penelope Si rius Sus sex Detors Aligt1ion Ledbury Anthony Liddesdale Beaufurt

  18. Learning from Our Lives: Women, Research, and Autobiography in Education.

    ERIC Educational Resources Information Center

    Neumann, Anna, Ed.; Peterson, Penelope L., Ed.

    The autobiographical essays in this volume offer insights into how the field of education might change as women assume positions of intellectual leadership. After the "Foreword" (Mary Catherine Bateson), the 13 chapters are: (1) "Research Lives: Women, Scholarship, and Autobiography in Education" (Anna Neumann and Penelope L.…

  19. Code System for Monte Carlo Simulation of Electron and Photon Transport.

    SciTech Connect

    2015-07-01

    Version 01 PENELOPE performs Monte Carlo simulation of coupled electron-photon transport in arbitrary materials and complex quadric geometries. A mixed procedure is used for the simulation of electron and positron interactions (elastic scattering, inelastic scattering and bremsstrahlung emission), in which ‘hard’ events (i.e. those with deflection angle and/or energy loss larger than pre-selected cutoffs) are simulated in a detailed way, while ‘soft’ interactions are calculated from multiple scattering approaches. Photon interactions (Rayleigh scattering, Compton scattering, photoelectric effect and electron-positron pair production) and positron annihilation are simulated in a detailed way. PENELOPE reads the required physical information about each material (which includes tables of physical properties, interaction cross sections, relaxation data, etc.) from the input material data file. The material data file is created by means of the auxiliary program MATERIAL, which extracts atomic interaction data from the database of ASCII files. PENELOPE mailing list archives and additional information about the code can be found at http://www.nea.fr/lists/penelope.html. See Abstract for additional features.

  20. Not-so-Soft Skills

    ERIC Educational Resources Information Center

    Curran, Mary

    2010-01-01

    Much recent discussion about the skills needed to secure Britain's economic recovery has focused on skills for employability. However, too often, these fundamental skills are understood in narrow functional or vocational terms. So-called "soft skills", what Penelope Tobin, in her 2008 paper "Soft Skills: the hard facts", terms "traits and…

  1. A Comparison Between GATE and MCNPX Monte Carlo Codes in Simulation of Medical Linear Accelerator

    PubMed Central

    Sadoughi, Hamid-Reza; Nasseri, Shahrokh; Momennezhad, Mahdi; Sadeghi, Hamid-Reza; Bahreyni-Toosi, Mohammad-Hossein

    2014-01-01

    Radiotherapy dose calculations can be evaluated by Monte Carlo (MC) simulations with acceptable accuracy for dose prediction in complicated treatment plans. In this work, Standard, Livermore and Penelope electromagnetic (EM) physics packages of GEANT4 application for tomographic emission (GATE) 6.1 were compared versus Monte Carlo N-Particle eXtended (MCNPX) 2.6 in simulation of 6 MV photon Linac. To do this, similar geometry was used for the two codes. The reference values of percentage depth dose (PDD) and beam profiles were obtained using a 6 MV Elekta Compact linear accelerator, Scanditronix water phantom and diode detectors. No significant deviations were found in PDD, dose profile, energy spectrum, radial mean energy and photon radial distribution, which were calculated by Standard and Livermore EM models and MCNPX, respectively. Nevertheless, the Penelope model showed an extreme difference. Statistical uncertainty in all the simulations was <1%, namely 0.51%, 0.27%, 0.27% and 0.29% for PDDs of 10 cm2× 10 cm2 filed size, for MCNPX, Standard, Livermore and Penelope models, respectively. Differences between spectra in various regions, in radial mean energy and in photon radial distribution were due to different cross section and stopping power data and not the same simulation of physics processes of MCNPX and three EM models. For example, in the Standard model, the photoelectron direction was sampled from the Gavrila-Sauter distribution, but the photoelectron moved in the same direction of the incident photons in the photoelectric process of Livermore and Penelope models. Using the same primary electron beam, the Standard and Livermore EM models of GATE and MCNPX showed similar output, but re-tuning of primary electron beam is needed for the Penelope model. PMID:24696804

  2. A Comparison Between GATE and MCNPX Monte Carlo Codes in Simulation of Medical Linear Accelerator.

    PubMed

    Sadoughi, Hamid-Reza; Nasseri, Shahrokh; Momennezhad, Mahdi; Sadeghi, Hamid-Reza; Bahreyni-Toosi, Mohammad-Hossein

    2014-01-01

    Radiotherapy dose calculations can be evaluated by Monte Carlo (MC) simulations with acceptable accuracy for dose prediction in complicated treatment plans. In this work, Standard, Livermore and Penelope electromagnetic (EM) physics packages of GEANT4 application for tomographic emission (GATE) 6.1 were compared versus Monte Carlo N-Particle eXtended (MCNPX) 2.6 in simulation of 6 MV photon Linac. To do this, similar geometry was used for the two codes. The reference values of percentage depth dose (PDD) and beam profiles were obtained using a 6 MV Elekta Compact linear accelerator, Scanditronix water phantom and diode detectors. No significant deviations were found in PDD, dose profile, energy spectrum, radial mean energy and photon radial distribution, which were calculated by Standard and Livermore EM models and MCNPX, respectively. Nevertheless, the Penelope model showed an extreme difference. Statistical uncertainty in all the simulations was <1%, namely 0.51%, 0.27%, 0.27% and 0.29% for PDDs of 10 cm(2)× 10 cm(2) filed size, for MCNPX, Standard, Livermore and Penelope models, respectively. Differences between spectra in various regions, in radial mean energy and in photon radial distribution were due to different cross section and stopping power data and not the same simulation of physics processes of MCNPX and three EM models. For example, in the Standard model, the photoelectron direction was sampled from the Gavrila-Sauter distribution, but the photoelectron moved in the same direction of the incident photons in the photoelectric process of Livermore and Penelope models. Using the same primary electron beam, the Standard and Livermore EM models of GATE and MCNPX showed similar output, but re-tuning of primary electron beam is needed for the Penelope model.

  3. Multiparticle Entanglement and Spatial Addressability of Ultracold Atoms in Optical Lattices

    DTIC Science & Technology

    2009-02-01

    Immanuel F. Bloch Stefan Kuhr Johannes Gutenberg-University Mainz Institute Fuer Physik/Quantum Mainz, Germany 55099 EOARD GRANT 07-3090...PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Johannes Gutenberg University Mainz Institute Fuer Physik/Quantum Mainz, Germany 55099 8...Entanglement and Spatial Addressability of Ultracold Atoms in Optical Lattices Prof. Dr. Immanuel Bloch Dr. Stefan Kuhr Johannes

  4. Preaward Evaluation and Responsibility Determination of Foreign Contractors.

    DTIC Science & Technology

    1988-12-01

    3 Contractor Country Contract Number Bundesamt Fuer Wehrtechnik FRG DAJA3786C0326 Bundesamt Fuer Wehrtechnik FRG F6154686D0022 Construcciones ...Aeronauticas SA Spain F0960385C0006 Construcciones Aeronauticas SA Spain F4260086C6464 Daimler Benz AG FRG DAJA3778GOO11 Eaton Corp. FRG F0960382D0663

  5. Utopische Literatur im Leistungskurs Englisch. Vorschlaege fuer Planung und Durchfuehrung eines halbjaehrigen Kurses (Utopian Literature in the English Honors Course. Suggestions for Planning and Teaching a Half-Year Course)

    ERIC Educational Resources Information Center

    Schnitter, Helmut

    1976-01-01

    Gives prerequisites for participation, editions of texts used (Orwell, "1984"; Huxley, "Brave New World"; More, "Utopia") and mentions auxiliary materials. After listing aims of the course, gives suggestions as to method and organization of the course. Sketches various phases of discussion and forms for checking on…

  6. "Deutsch ist doch keine Fremdsprache!" - Ausbildungsgaenge fuer Lehrer auslaendischer Kinder an deutschen Schulen ("But German is not a Foreign Language!" Training for German Teachers of Foreign Children in German Schools)

    ERIC Educational Resources Information Center

    Reich, Hans H.

    1976-01-01

    Children of foreign workers in Germany have a language problem differing from that of German children studying (e.g.) English. With the goal of integrating the foreign children into German life, teachers with certain qualities and skills are needed. An appropriate teachers' training course is described. (Text is in German.) (IFS/WGA)

  7. Bouchon d’oreille a attenuation active adaptee aux bruits d’helicoptere (Ear Plugs for Active Attenuation Adapted for Helicopter Noises) (Gehoerschutzstopsel mit aktriver Daempfung, geeignet fuer Hubschrauberlaerm)

    DTIC Science & Technology

    2006-04-01

    Hubschrauberharm RWsum6 Le spectre du bruit d’un h~licopt~re se compose de deux parties bien distinctes. La premi~re est une composante basses frquences...61ectrique comme haut-parleur. Avec cc type d’t6metteur, on parties bien distinctes. La premiere est une composante arrivait A obtenir une...d’augmenter la vitesse de convergence. Pour le syst~me les signaul y1 n dr etr Pournl sont dtcm in fedack, de dimnl inue feedforward on a choisi

  8. Die Gasultrazentrifuge als mediale Projektion des Kalten Krieges

    NASA Astrophysics Data System (ADS)

    Helmbold, Bernd

    Studien der letzten Dekaden nach der Wiedervereinigung von BRD und DDR erweitern die Perspektive der Wissenschaftsgeschichte vom Fokus des Big Science und der technisch-militärisch-industriellen Auseinandersetzung zwischen den zwei Blöcken zu einer globalen Transformation im Konflikt der Supermächte geprägt durch lokale und auch interne Ausformungen.

  9. The Conflict Aftermath - A Chance for Democracy: Norm Diffusion in Post-Conflict Peace Building

    DTIC Science & Technology

    2007-06-01

    Studien Verlag, 2005);Toby Thacker, “Playing Beethoven like an Indian: American Music and Reorientation in Germany, 1945-1955,” in The Postwar Challenge...Europe Transformed 1878-1919. 2nd edition. London: Blackwell Publishing, 1999. Thacker, Toby. “Playing Beethoven like an Indian: American Music and

  10. Monte Carlo simulation of the Leksell Gamma Knife®: I. Source modelling and calculations in homogeneous media

    NASA Astrophysics Data System (ADS)

    Moskvin, Vadim; DesRosiers, Colleen; Papiez, Lech; Timmerman, Robert; Randall, Marcus; DesRosiers, Paul

    2002-06-01

    The Monte Carlo code PENELOPE has been used to simulate photon flux from the Leksell Gamma Knife®, a precision method for treating intracranial lesions. Radiation from a single 60Co assembly traversing the collimator system was simulated, and phase space distributions at the output surface of the helmet for photons and electrons were calculated. The characteristics describing the emitted final beam were used to build a two-stage Monte Carlo simulation of irradiation of a target. A dose field inside a standard spherical polystyrene phantom, usually used for Gamma Knife® dosimetry, has been computed and compared with experimental results, with calculations performed by other authors with the use of the EGS4 Monte Carlo code, and data provided by the treatment planning system Gamma Plan®. Good agreement was found between these data and results of simulations in homogeneous media. Owing to this established accuracy, PENELOPE is suitable for simulating problems relevant to stereotactic radiosurgery.

  11. A combined approach of variance-reduction techniques for the efficient Monte Carlo simulation of linacs

    NASA Astrophysics Data System (ADS)

    Rodriguez, M.; Sempau, J.; Brualla, L.

    2012-05-01

    A method based on a combination of the variance-reduction techniques of particle splitting and Russian roulette is presented. This method improves the efficiency of radiation transport through linear accelerator geometries simulated with the Monte Carlo method. The method named as ‘splitting-roulette’ was implemented on the Monte Carlo code \\scriptsize{{PENELOPE}} and tested on an Elekta linac, although it is general enough to be implemented on any other general-purpose Monte Carlo radiation transport code and linac geometry. Splitting-roulette uses any of the following two modes of splitting: simple splitting and ‘selective splitting’. Selective splitting is a new splitting mode based on the angular distribution of bremsstrahlung photons implemented in the Monte Carlo code \\scriptsize{{PENELOPE}}. Splitting-roulette improves the simulation efficiency of an Elekta SL25 linac by a factor of 45.

  12. Systematic discrepancies in Monte Carlo predictions of k-ratios emitted from thin films on substrates

    NASA Astrophysics Data System (ADS)

    Statham, P.; Llovet, X.; Duncumb, P.

    2012-03-01

    We have assessed the reliability of different Monte Carlo simulation programmes using the two available Bastin-Heijligers databases of thin-film measurements by EPMA. The MC simulation programmes tested include Curgenven-Duncumb MSMC, NISTMonte, Casino and PENELOPE. Plots of the ratio of calculated to measured k-ratios ("kcalc/kmeas") against various parameters reveal error trends that are not apparent in simple error histograms. The results indicate that the MC programmes perform quite differently on the same dataset. However, they appear to show a similar pronounced trend with a "hockey stick" shape in the "kcalc/kmeas versus kmeas" plots. The most sophisticated programme PENELOPE gives the closest correspondence with experiment but still shows a tendency to underestimate experimental k-ratios by 10 % for films that are thin compared to the electron range. We have investigated potential causes for this systematic behaviour and extended the study to data not collected by Bastin and Heijligers.

  13. Standardisation of positron-emitters in gas with the NPL primary gas counting system.

    PubMed

    Marouli, M; Dean, J C J; Sephton, J P; Spyrou, N M

    2010-01-01

    A primary standard for positron-emitters in gas has been developed. The method involves internal gas proportional counting and the use of the PENELOPE Monte Carlo code to determine corrections for counting losses. The development work was carried out using (11)C, although the method can be applied to other positron emitters. The results were compared with measurements of (11)C (in solution) carried out using a secondary standard re-entrant ionisation chamber previously calibrated with reference to absolute counting techniques.

  14. BC's "Island of death" marked a sad chapter in Canada's medical history.

    PubMed Central

    Johnston, P

    1995-01-01

    Although the first case of leprosy in Canada was detected in 1815 in New Brunswick, the saddest chapter concerning the disease's history in Canada did not open until the late 1800s when leprosy was discovered among Chinese migrant workers on Canada's West Coast--a chapter that was not closed until 1957. Penelope Johnston relates the story of British Columbia's "Island of Death," where lepers used to be quarantined. PMID:7697589

  15. BC's "Island of death" marked a sad chapter in Canada's medical history.

    PubMed

    Johnston, P

    1995-03-15

    Although the first case of leprosy in Canada was detected in 1815 in New Brunswick, the saddest chapter concerning the disease's history in Canada did not open until the late 1800s when leprosy was discovered among Chinese migrant workers on Canada's West Coast--a chapter that was not closed until 1957. Penelope Johnston relates the story of British Columbia's "Island of Death," where lepers used to be quarantined.

  16. Influenza A(H5N8) virus isolation in Russia, 2014.

    PubMed

    Marchenko, Vasiliy Y; Susloparov, Ivan M; Kolosova, Nataliya P; Goncharova, Nataliya I; Shipovalov, Andrey V; Durymanov, Alexander G; Ilyicheva, Tatyana N; Budatsirenova, Lubov V; Ivanova, Valentina K; Ignatyev, Georgy A; Ershova, Svetlana N; Tulyahova, Valeriya S; Mikheev, Valeriy N; Ryzhikov, Alexander B

    2015-11-01

    In this study, we report the isolation of influenza A(H5N8) virus from a Eurasian wigeon (Anas penelope) in Sakha Republic of the Russian Far East. The strain A/wigeon/Sakha/1/2014 (H5N8) has been shown to be pathogenic for mammals. It is similar to the strains that caused outbreaks in wild birds and poultry in Southeast Asia and Europe in 2014.

  17. Three new species and the first known males of the Andean spider genus Orinomana Strand (Araneae, Uloboridae).

    PubMed

    Grismado, Cristian J; Rubio, Gonzalo D

    2015-12-02

    Three new species of the uloborid genus Orinomana Strand, O. penelope n. sp. from Ecuador, O. viracocha n. sp. from Peru, and O. florezi n. sp. from Colombia, are described. Additionally, the male of O. ascha Grismado, from Northwestern Argentina, is described for the first time. This material includes the first males known of the genus, providing diagnostic characters for its recognition; the complex and massive embolus with several branches is proposed as a synapomorphy of the genus.

  18. 18. HISTORIC VIEW OF MAX VALIER, FOUNDING MEMBER OF THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. HISTORIC VIEW OF MAX VALIER, FOUNDING MEMBER OF THE VEREIN FUER RAUMSCHIFFAHRT (GERMAN SOCIETY FOR SPACE TRAVEL), DRIVES HIS ROCKET CAR IN 1931. - Marshall Space Flight Center, Redstone Rocket (Missile) Test Stand, Dodd Road, Huntsville, Madison County, AL

  19. Source Hierarchy List. Volume 3. O through Z

    DTIC Science & Technology

    1994-07-01

    PHOTOGRAMMETRY 02 TECHNISCHE UNIV GRAZ (AUSTRIA) DEPT OF PHOTOGRAPHY* 01 TECHNISCHE UNIV GRAZ (AUSTRIA) INST FUER DIGITALE BILBERARBEITUNG IN...UNIVERSIDAD NACIONAL AUTCHOMA DE MEXICO MEXICO CITY CEWTRO DE IHVESTIGACION EN MATEMATICAS APLICADAS/ SISTEMAS * Of UNIVERSIDAD NACIONAL AUTONOMA DE MEXICO

  20. Military Periodicals.

    DTIC Science & Technology

    1983-05-01

    per year) ICDM of North America, Inc. 2065 Martin Avenue, Ste. 104 Santa Clara, California 95050 Executive Editor: Rosalyn 0. Barry $36.00 NCOA...Djurgaardsslatten 92 115 21 Stockholm, Sweden Telephone: 08-782 56 10 Editor: Hans Ulfhielm Kr. 30 Militaer Geschichte (6/yr) Institut Fuer Deutsche ... Deutsche Gesellschaft fuer Heereskunde e.v. Augustin-Wibbelt Strasse 8 4720 Beckum, West Germany DM.60 Znamenosets (M) (Formerly Starshina

  1. Modifications to Army Facilities Components System Drawings to Reflect Use of Metric-Sized Lumber.

    DTIC Science & Technology

    1986-09-01

    2040 x 915 PHENAPAN DEUTSCHE NOVOPAN SP ISO-Verle- NSCM: XN003 geplatte V 100 - 00-V02-473! 19.0 2050 x 925 2040 x 915 ditto ditto Si: - 00-V02-4732...use: Build-in furniture Spanplatte, beide Seiten geschliffen, Gueteklasse I-I Verwcndungszweck: Fuer Einbaumoebel CODE 5530 Staerke Abmessungen...laminated, flat pressed, both sides sanded, for general purpose; DIN 68761 Holzspanplatte (Flachpressplatte), beide Seiten geschliffen, fuer allgemeine

  2. Antigens for a Vaccine that Prevents Severe Malaria

    DTIC Science & Technology

    2007-03-01

    Hutagalung, R . et al. (1999) Influence of hemoglobin E trait on the severity of falciparum malaria. J. Infect. Dis. 179, 283–286 8 Ruwende, C. et al...erythrocytic stage in mam- malian malaria parasites. Nature 161: 126. 2. Shortt HE, Fairley NH, Covell G, Shute PG, Garnham PC, 1951. The pre-erythrocytic...stage of Plasmodium falciparum. Trans R Soc Trop Med Hyg 44: 405–419. 3. Schaudinn F, 1903. Studien ueber krankheitserregende Proto- zoen II

  3. [Caregivers' needs concerning mobility support of a family member with terminal cancer - a narrative review].

    PubMed

    Gattinger, Heidrun; Siegl, Eva; Senn, Beate; Hantikainen, Virpi

    2014-06-01

    Hintergrund: Die häusliche Pflege krebskranker Menschen wird häufig von Angehörigen übernommen. Die letzte Lebensphase geht in der Regel mit Einschränkungen der Bewegungsfähigkeit einher. Ziel: Ziel dieser narrativen Literaturübersicht ist es, die Bedürfnisse pflegender Angehöriger bezüglich Mobilitätsunterstützung und -förderung bei der alltäglichen Pflege des an Krebs erkrankten Familienmitgliedes am Lebensende zu erfassen. Methode: Die Literatursuche erfolgte in den Datenbanken Cochrane, PubMed, PsychINFO, ERIC und CINAHL. Eingeschlossen wurden englisch- und deutschsprachige Studien, die Bedürfnisse betreffend der Mobilitätsunterstützung und -förderung der Angehörigen hinsichtlich der häuslichen Pflege krebskranker Menschen untersuchten. Zwei Autorinnen beurteilten die methodische Qualität der eingeschlossenen Studien. Ergebnisse: Insgesamt wurden elf Studien mit unterschiedlichen Studiendesigns eingeschlossen. Die Ergebnisse zeigen, dass das Bedürfnis nach Information, Anleitung und Unterstützung betreffend Mobilität in zwei Bereichen besteht: i) Tätigkeiten des alltäglichen Lebens inklusive Körperpflege und ii) Einsatz von Hilfsmitteln inklusive Transport. Schlussfolgerung: Die Literaturanalyse zeigt, dass Bedürfnisse pflegender Angehöriger zu pflegerischen Skills bezüglich der Mobilitätsunterstützung und -förderung unzureichend und unsystematisch beschrieben sind. Zukünftige Studien sind notwendig, in denen diese Bedürfnisse systematisch untersucht werden, um darauf aufbauend gut definierte Interventionen für die Vermittlung pflegerischer Skills zu entwickeln.

  4. SU-E-T-626: Accuracy of Dose Calculation Algorithms in MultiPlan Treatment Planning System in Presence of Heterogeneities

    SciTech Connect

    Moignier, C; Huet, C; Barraux, V; Loiseau, C; Sebe-Mercier, K; Batalla, A; Makovicka, L

    2014-06-15

    Purpose: Advanced stereotactic radiotherapy (SRT) treatments require accurate dose calculation for treatment planning especially for treatment sites involving heterogeneous patient anatomy. The purpose of this study was to evaluate the accuracy of dose calculation algorithms, Raytracing and Monte Carlo (MC), implemented in the MultiPlan treatment planning system (TPS) in presence of heterogeneities. Methods: First, the LINAC of a CyberKnife radiotherapy facility was modeled with the PENELOPE MC code. A protocol for the measurement of dose distributions with EBT3 films was established and validated thanks to comparison between experimental dose distributions and calculated dose distributions obtained with MultiPlan Raytracing and MC algorithms as well as with the PENELOPE MC model for treatments planned with the homogenous Easycube phantom. Finally, bones and lungs inserts were used to set up a heterogeneous Easycube phantom. Treatment plans with the 10, 7.5 or the 5 mm field sizes were generated in Multiplan TPS with different tumor localizations (in the lung and at the lung/bone/soft tissue interface). Experimental dose distributions were compared to the PENELOPE MC and Multiplan calculations using the gamma index method. Results: Regarding the experiment in the homogenous phantom, 100% of the points passed for the 3%/3mm tolerance criteria. These criteria include the global error of the method (CT-scan resolution, EBT3 dosimetry, LINAC positionning …), and were used afterwards to estimate the accuracy of the MultiPlan algorithms in heterogeneous media. Comparison of the dose distributions obtained in the heterogeneous phantom is in progress. Conclusion: This work has led to the development of numerical and experimental dosimetric tools for small beam dosimetry. Raytracing and MC algorithms implemented in MultiPlan TPS were evaluated in heterogeneous media.

  5. SU-E-T-36: A GPU-Accelerated Monte-Carlo Dose Calculation Platform and Its Application Toward Validating a ViewRay Beam Model

    SciTech Connect

    Wang, Y; Mazur, T; Green, O; Hu, Y; Wooten, H; Yang, D; Zhao, T; Mutic, S; Li, H

    2015-06-15

    Purpose: To build a fast, accurate and easily-deployable research platform for Monte-Carlo dose calculations. We port the dose calculation engine PENELOPE to C++, and accelerate calculations using GPU acceleration. Simulations of a Co-60 beam model provided by ViewRay demonstrate the capabilities of the platform. Methods: We built software that incorporates a beam model interface, CT-phantom model, GPU-accelerated PENELOPE engine, and GUI front-end. We rewrote the PENELOPE kernel in C++ (from Fortran) and accelerated the code on a GPU. We seamlessly integrated a Co-60 beam model (obtained from ViewRay) into our platform. Simulations of various field sizes and SSDs using a homogeneous water phantom generated PDDs, dose profiles, and output factors that were compared to experiment data. Results: With GPU acceleration using a dated graphics card (Nvidia Tesla C2050), a highly accurate simulation – including 100*100*100 grid, 3×3×3 mm3 voxels, <1% uncertainty, and 4.2×4.2 cm2 field size – runs 24 times faster (20 minutes versus 8 hours) than when parallelizing on 8 threads across a new CPU (Intel i7-4770). Simulated PDDs, profiles and output ratios for the commercial system agree well with experiment data measured using radiographic film or ionization chamber. Based on our analysis, this beam model is precise enough for general applications. Conclusions: Using a beam model for a Co-60 system provided by ViewRay, we evaluate a dose calculation platform that we developed. Comparison to measurements demonstrates the promise of our software for use as a research platform for dose calculations, with applications including quality assurance and treatment plan verification.

  6. DFVLR/FAA (Deutsche Forschungs-und Versuchsanstalt fuer Luft und Raumfahrt/Federal Aviation Administration) Propeller Noise Tests in the German-Dutch Wind Tunnel DNW. Appendix V. The Effect of Propeller Disc-Plane Attitude (Propeller 2: Thickness 8.5%, Square Tip-Shape),

    DTIC Science & Technology

    1986-01-01

    100 PlX 1. ul -100 cl -200 0L a- -300 -400 -i PMIN= -340.2 -500 1 .0 .5 1.0 TIME - REV. 120 AVERAGE (70) P IOWER SPECTRUM OF= 11 .2 Hz 110 00 0...268 4: 3.60 T: 288.6 K, AVERAGE (68) TIME HISTOPY (AP < 56 %) PMAX= 60.9 50 -- ,’-qJ .. 50 TIME- 0 ul -50 Lu a., -,,ɜ - Io -200 r18 . .0 .5 1.0 TIME

  7. Allgemeine Sprachfaehigkeit und Fremdsprachenerwerb. Zur Struktur von Leistungsdimensionen und linguistischer Kompetenz des Fremdsprachenlerners (General Language Ability and Foreign Language Acquisition. On the Structure of Performance Dimensions and the Linguistic Competence of the Foreign Language Learner). Diskussions beitraege aus dem Institute fuer Bildungsforschung, No. 1.

    ERIC Educational Resources Information Center

    Sang, Fritz; Vollmer, Helmut J.

    This study investigates the theoretical plausibility and empirical validity of the assumption that all performance in a foreign language can be traced back to a single factor, the general language ability factor. The theoretical background of this hypothesis is reviewed in detail. The concept of a unitary linguistic competence, interpreted as an…

  8. Integrity and security in an Ada runtime environment

    NASA Technical Reports Server (NTRS)

    Bown, Rodney L.

    1991-01-01

    A review is provided of the Formal Methods group discussions. It was stated that integrity is not a pure mathematical dual of security. The input data is part of the integrity domain. The group provided a roadmap for research. One item of the roadmap and the final position statement are closely related to the space shuttle and space station. The group's position is to use a safe subset of Ada. Examples of safe sets include the Army Secure Operating System and the Penelope Ada verification tool. It is recommended that a conservative attitude is required when writing Ada code for life and property critical systems.

  9. A Preliminary Overview of Cultural History in the Lower Rio Chama, New Mexico.

    DTIC Science & Technology

    1980-09-15

    Schaafsma (197614) suggests that the home base for these early Anasasi hunters was the Rosa Phase settlement around Dulce , New Mexico . This may explain...Preliminary Overview of Cultural History in the Lower Rio Chama, New Mexico P/ ~~ I Penelope Whitten and Margaret A. Powers i TIc 1980 |ozpulic...TO en Sub9 S. R’~’eport Date ’"" and ’ue A Preliminary Overview of Cultural History in the L 1980. Lower Rio Chama; New Mexico 1. 7. A t~"s) a

  10. The Middle East, and Her Geographic Approaches.

    DTIC Science & Technology

    2014-09-26

    NAKHLEH, EMILE A. "BAHRAIN AND QATAR: SOCIOPOLITICAL DEVELOPMENTS", AEI, 2:3,4,:65-7, ,* .. L . -’. -> .’ --. ’..’ ~ .- ~. -.p .-, CYPRUS WANS, T.W. " CRISIS ...34 JORUSI, 105൥-47, FEB.1960. STEWART, RICHARD A. "OMAN: THE NEXT CRISIS ? USNIP, 106:97-102,APR.1980. TREMAYNE, PENELOPE. "END OF & TEN YEARS WAR...9, JAN.1974. "KUWAIT: DETERRENCE AND INSTABILITY," AFJI, 118:59-60, NOV.1980. LEE, DAVID "BRITISH DEPARTURE FROM THE MIDDLE EAST: THE KUWAIT CRISIS OF

  11. Benchmarking of Monte Carlo simulation of bremsstrahlung from thick targets at radiotherapy energies

    PubMed Central

    Faddegon, Bruce A.; Asai, Makoto; Perl, Joseph; Ross, Carl; Sempau, Josep; Tinslay, Jane; Salvat, Francesc

    2008-01-01

    Several Monte Carlo systems were benchmarked against published measurements of bremsstrahlung yield from thick targets for 10–30 MV beams. The quantity measured was photon fluence at 1 m per unit energy per incident electron (spectra), and total photon fluence, integrated over energy, per incident electron (photon yield). Results were reported at 10–30 MV on the beam axis for Al and Pb targets and at 15 MV at angles out to 90° for Be, Al, and Pb targets. Beam energy was revised with improved accuracy of 0.5% using an improved energy calibration of the accelerator. Recently released versions of the Monte Carlo systems EGSNRC, GEANT4, and PENELOPE were benchmarked against the published measurements using the revised beam energies. Monte Carlo simulation was capable of calculation of photon yield in the experimental geometry to 5% out to 30°, 10% at wider angles, and photon spectra to 10% at intermediate photon energies, 15% at lower energies. Accuracy of measured photon yield from 0 to 30° was 5%, 1 s.d., increasing to 7% for the larger angles. EGSNRC and PENELOPE results were within 2 s.d. of the measured photon yield at all beam energies and angles, GEANT4 within 3 s.d. Photon yield at nonzero angles for angles covering conventional field sizes used in radiotherapy (out to 10°), measured with an accuracy of 3%, was calculated within 1 s.d. of measurement for EGSNRC, 2 s.d. for PENELOPE and GEANT4. Calculated spectra closely matched measurement at photon energies over 5 MeV. Photon spectra near 5 MeV were underestimated by as much as 10% by all three codes. The photon spectra below 2–3 MeV for the Be and Al targets and small angles were overestimated by up to 15% when using EGSNRC and PENELOPE, 20% with GEANT4. EGSNRC results with the NIST option for the bremsstrahlung cross section were preferred over the alternative cross section available in EGSNRC and over EGS4. GEANT4 results calculated with the “low energy” physics list were more accurate than

  12. Benchmarking of Monte Carlo simulation of bremsstrahlung from thick targets at radiotherapy energies

    SciTech Connect

    Faddegon, Bruce A.; Asai, Makoto; Perl, Joseph; Ross, Carl; Sempau, Josep; Tinslay, Jane; Salvat, Francesc

    2008-10-15

    Several Monte Carlo systems were benchmarked against published measurements of bremsstrahlung yield from thick targets for 10-30 MV beams. The quantity measured was photon fluence at 1 m per unit energy per incident electron (spectra), and total photon fluence, integrated over energy, per incident electron (photon yield). Results were reported at 10-30 MV on the beam axis for Al and Pb targets and at 15 MV at angles out to 90 degree sign for Be, Al, and Pb targets. Beam energy was revised with improved accuracy of 0.5% using an improved energy calibration of the accelerator. Recently released versions of the Monte Carlo systems EGSNRC, GEANT4, and PENELOPE were benchmarked against the published measurements using the revised beam energies. Monte Carlo simulation was capable of calculation of photon yield in the experimental geometry to 5% out to 30 degree sign , 10% at wider angles, and photon spectra to 10% at intermediate photon energies, 15% at lower energies. Accuracy of measured photon yield from 0 to 30 degree sign was 5%, 1 s.d., increasing to 7% for the larger angles. EGSNRC and PENELOPE results were within 2 s.d. of the measured photon yield at all beam energies and angles, GEANT4 within 3 s.d. Photon yield at nonzero angles for angles covering conventional field sizes used in radiotherapy (out to 10 degree sign ), measured with an accuracy of 3%, was calculated within 1 s.d. of measurement for EGSNRC, 2 s.d. for PENELOPE and GEANT4. Calculated spectra closely matched measurement at photon energies over 5 MeV. Photon spectra near 5 MeV were underestimated by as much as 10% by all three codes. The photon spectra below 2-3 MeV for the Be and Al targets and small angles were overestimated by up to 15% when using EGSNRC and PENELOPE, 20% with GEANT4. EGSNRC results with the NIST option for the bremsstrahlung cross section were preferred over the alternative cross section available in EGSNRC and over EGS4. GEANT4 results calculated with the ''low energy

  13. Rotation parameters and shapes of 15 asteroids

    NASA Astrophysics Data System (ADS)

    Tungalag, N.; Shevchenko, V. G.; Lupishko, D. F.

    2002-12-01

    With the use of the combined method (the amplitude and magnitude method plus the epoch method) pole coordinates, sidereal rotation periods, and axial ratios of triaxial ellipsoid figures for asteroids 22 Kalliope, 75 Eurydike, 93 Minerva, 97 Klotho, 105 Artemis, 113 Amalthea, 119 Althaea, 201 Penelope, 270 Anahita, 338 Budrosa, 487 Venetia, 674 Rachele, 776 Berbericia, 887 Alinda, nd 951 Gaspra were determined. For eight of them (asteroids 75, 97, 105, 113, 119, 338, 674, and 887) these values were obtained for the first time. We used the numerical photometric asteroid model based on ellipsoidal asteroid shape, homogeneous albedo distribution over the surface, and Akimov's scattering law.

  14. Photons, Electrons and Positrons Transport in 3D by Monte Carlo Techniques

    SciTech Connect

    2014-12-01

    Version 04 FOTELP-2014 is a new compact general purpose version of the previous FOTELP-2K6 code designed to simulate the transport of photons, electrons and positrons through three-dimensional material and sources geometry by Monte Carlo techniques, using subroutine package PENGEOM from the PENELOPE code under Linux-based and Windows OS. This new version includes routine ELMAG for electron and positron transport simulation in electric and magnetic fields, RESUME option and routine TIMER for obtaining starting random number and for measuring the time of simulation.

  15. Low Bacterial Diversity and High Labile Organic Matter Concentrations in the Sediments of the Medee Deep-Sea Hypersaline Anoxic Basin

    PubMed Central

    Akoumianaki, Ioanna; Nomaki, Hidetaka; Pachiadaki, Maria; Kormas, Konstantinos Ar.; Kitazato, Hiroshi; Tokuyama, Hidekazu

    2012-01-01

    Studies in the center and margin of the Medee Basin, a Mediterranean deep-sea hypersaline anoxic basin, and at a reference site during Penelope cruise (2007), revealed the existence of a 7 m-thick halocline, with high salinity (328 psu), and high sedimentary organic carbon and biopolymer concentrations. The 194 16S rRNA sequences retrieved were grouped into 118 unique phylotypes. Pseudomonas gessardii, dominated in the center, while 33 phylotypes were detected at the margin and 73 at the reference site. The study suggested conditions hostile to bacteria in the sediments of the Medee Basin and preservation of sedimentary labile organic matter. PMID:22504432

  16. Tumoral fibrosis effect on the radiation absorbed dose of (177)Lu-Tyr(3)-octreotate and (177)Lu-Tyr(3)-octreotate conjugated to gold nanoparticles.

    PubMed

    Azorín-Vega, E P; Zambrano-Ramírez, O D; Rojas-Calderón, E L; Ocampo-García, B E; Ferro-Flores, G

    2015-06-01

    The aim of this work was to evaluate the tumoral fibrosis effect on the radiation absorbed dose of the radiopharmaceuticals (177)Lu-Tyr(3)-octreotate (monomeric) and (177)Lu-Tyr(3)-octreotate-gold nanoparticles (multimeric) using an experimental HeLa cells tumoral model and the Monte Carlo PENELOPE code. Experimental and computer micro-environment models with or without fibrosis were constructed. Results showed that fibrosis increases up to 33% the tumor radiation absorbed dose, although the major effect on the dose was produced by the type of radiopharmaceutical (112Gy-multimeric vs. 43Gy-monomeric).

  17. Photometric geodesy of main-belt asteroids. III. Additional lightcurves

    SciTech Connect

    Weidenschilling, S.J.; Chapman, C.R.; Davis, D.R.; Greenberg, R.; Levy, D.H. )

    1990-08-01

    A total of 107 complete or partial lightcurves are presented for 59 different asteroids over the 1982-1989 period. Unusual lightcurves with unequal minima and maxima at large amplitudes are preferentially seen for M-type asteroids. Some asteroids, such as 16 Psyche and 201 Penelope, exhibit lightcurves combining large amplitude with very unequal brightness for both maxima and both minima, even at small phase angles. An M-type asteroid is believed to consist of a metal core of a differentiated parent body that has had its rocky mantle completely removed by one or more large impacts. 39 refs.

  18. Progress in the use of gadolinium for NCT.

    PubMed

    Cerullo, N; Bufalino, D; Daquino, G

    2009-07-01

    The evaluation of possible improvement in the use of Gd in cancer therapy, in reference to gadolinium in cancer therapy (GdNCT), has been analysed. At first the problem of the gadolinium compounds toxicity was reviewed identifying the Motexafin Gadolinium as the best. Afterwards, the spectrum of IC and Auger electrons was calculated using a special method. Afterwards, this electron source has been used as input of the PENELOPE code and the energy deposit in DNA was well defined. Taking into account that the electron yield and energy distribution are related to the neutron beam spectrum and intensity, the shaping assembly architecture was optimised through computational investigations. Finally the study of GdNCT was performed from two different points of view: macrodosimetry using MCNPX, with calculation of absorbed doses both in tumour and healthy tissues, and microdosimetry using PENELOPE, with the determination of electron RBE through the energy deposit. The equivalent doses were determined combining these two kinds of data, introducing specific figures of merit to be used in treatment planning system (TPS). According to these results, the GdNCT appears to be a fairly possible tumour therapy.

  19. Z-dependence of thick-target bremsstrahlung produced by monoenergetic low-energy electrons

    NASA Astrophysics Data System (ADS)

    Czarnecki, S.; Short, A.; Williams, S.

    2016-07-01

    The dependence of thick-target bremsstrahlung emitted by low-energy beams of monoenergetic electrons on the atomic number of the target material has been investigated experimentally for incident electron energies of 4.25 keV and 5.00 keV using thick aluminum, copper, silver, tungsten, and gold targets. Experimental data suggest that the intensity of the thick-target bremsstrahlung emitted is more strongly dependent on the atomic number of the target material for photons with energies that are approximately equal to the energy of the incident electrons than at lower energies, and also that the dependence of thick-target bremsstrahlung on the atomic number of the target material is stronger for incident electrons of higher energies than for incident electrons of lower energies. The results of the experiments are compared to the results of simulations performed using the PENELOPE program (which is commonly used in medical physics) and to thin-target bremsstrahlung theory, as well. Comparisons suggest that the experimental dependence of thick-target bremsstrahlung on the atomic number of the target material may be slightly stronger than the results of the PENELOPE code suggest.

  20. Application of the CIEMAT-NIST method to plastic scintillation microspheres.

    PubMed

    Tarancón, A; Barrera, J; Santiago, L M; Bagán, H; García, J F

    2015-04-01

    An adaptation of the MICELLE2 code was used to apply the CIEMAT-NIST tracing method to the activity calculation for radioactive solutions of pure beta emitters of different energies using plastic scintillation microspheres (PSm) and (3)H as a tracing radionuclide. Particle quenching, very important in measurements with PSm, was computed with PENELOPE using geometries formed by a heterogeneous mixture of polystyrene microspheres and water. The results obtained with PENELOPE were adapted to be included in MICELLE2, which is capable of including the energy losses due to particle quenching in the computation of the detection efficiency. The activity calculation of (63)Ni, (14)C, (36)Cl and (90)Sr/(90)Y solutions was performed with deviations of 8.8%, 1.9%, 1.4% and 2.1%, respectively. Of the different parameters evaluated, those with the greatest impact on the activity calculation are, in order of importance, the energy of the radionuclide, the degree of quenching of the sample and the packing fraction of the geometry used in the computation.

  1. The Future of NATO and an Evolving European Security Interest

    DTIC Science & Technology

    2010-03-03

    2009, p.56 30 Benjamin S. Lambeth, “NATO’s Air War for Kosovo: A strategic and Operational Assessment, Santa Monica, RAND 2001, pp. xiii -xxiv 31...Klaus Nauman, General German Army ret., Former Chief MC NATO, “Sicherheit ohne die USA? Die NATO in der Perzeption Europas “, Berichte und Studien – Die...das größere Europa ?“, Hans Arnold, Raimund Krämer, “Sicherheit für das größere Europa “, Bonn 2002, p. 355 46 François N.Heisbourg. “Europe’s

  2. Doktor Johannes Häringshauser - Was seine Bücher über ihn erzählen.

    NASA Astrophysics Data System (ADS)

    Feola, Vittoria

    2009-06-01

    Die Bibliothek des Dr. Johannes Häringshauser (1603-1642) weist ihren Besitzer als Arzt und Gelehrten mit großem geistigen Horizont aus. Hervorzuheben ist sein Interesse für Astronomie und Astrologie. Neben Werken, die unmittelbar mit seinen Studien in Wien und Padua und den Erfordernissen eines Arztes in Zusammenhang zu bringen sind (Klassiker der Heilkunde genauso wie aktuelle medizinische Publikationen), wird in seiner Büchersammlung eine reiche Palette an Themen abgedeckt: Theologie, Philosophie, Philologie, Politik, Geschichte und Länderkunde.

  3. Molekülbillard

    NASA Astrophysics Data System (ADS)

    Weiser, Martin

    Die Entwicklung moderner Medikamente (siehe Abbildung 1) zielt auf das Design von hochspezifischen Wirkstoffen, um Nebenwirkungen so weit wie möglich auszuschließen. Da biochemische Reaktionen, z. B. die Blockade eines Rezeptors durch ein Wirkstoffmolekül, zumeist nach dem Schlüssel-Schloss-Prinzip funktionieren, ist die Gestalt von Molekülen entscheidend für die Wirksamkeit. Biochemische Tests oder gar klinische Studien sind aufwändig und teuer, daher werden zunehmend mathematische Simulationsverfahren zur Berechnung der Gestalt von Molekülen verwendet.

  4. Imagineering the astronomical revolution - Essay review

    NASA Astrophysics Data System (ADS)

    Jardine, Nicholas.

    2006-11-01

    Concerning following Books: (I) Transmitting knowledge - words, images, and instruments in early modern Europe. Kusukawa and Maclean (eds.), OUP, Oxford, 2006; (II) Widmung, Welterklärung und Wissenschaftslegitimierung: Titelbilder und ihre Funktionen in der wissenschaftlichen Revolution. Remmert, Harrassowitz, Wiesbaden, 2005; (III) The power of images in early modern science. Lefevre, Renn and Schoepflin (eds.), Birkhäuser, Basel, 2003; (IV) Immagini per conoscere - dal Rinascimento alla rivoluzione scientifica. Meroi and Pogliano (eds.), Olschki, Florenz, 2001; (V) Erkenntnis Erfindung Konstruktion - Studien zur Bildgeschichte von Naturwissenschaften und Technik vom 16. bis zum 19. Jahrhundert. Holländer (ed.), Mann, Berlin, 2000.

  5. Navigating the maze of requirements for obtaining approval of non-interventional studies (NIS) in the European Union.

    PubMed

    Ramirez, Isabelle

    2015-01-01

    Ziel: Dieser Artikel soll über die Komplexität und unerwartete regulatorische Anforderungen bei multinationalen und multizentrischen, nicht-interventionellen Studien (NIS) in der Europäischen Union aufklären.Methoden: Die Internetseiten der zuständigen nationalen Behörden, Ethikkommissionen (EK) und Datenschutzbehörden wurden konsultiert, um Vorschriften und Richtlinien zum Genehmigungsverfahren von NIS in den verschiedenen Mitgliedstaaten der EU zu finden.Ergebnis: Viele zusätzliche Hürden wurden identifiziert, die weder offengelegt noch deutlich in den jeweiligen Verordnungen/Richtlinien für NIS beschrieben waren. Obwohl die Genehmigung durch die nationale Behörde für NIS grundsätzlich nicht erforderlich ist, wird in vielen Ländern dennoch empfohlen die geplante NIS – vor dem EK-Antrag – der nationalen Behörde anzuzeigen, um die Bestätigung zu erhalten, dass die geplante NIS nicht in die Kategorie „interventionelle Studie“ fällt. Zudem ist in einigen Ländern eine Probandenversicherung erforderlich. In vielen Ländern, in denen multizentrische NIS geplant sind, bedarf es zusätzlich zur Zustimmung der zentralen Ethikkommission auch noch die zustimmende Bewertung aller lokalen Ethikkommissionen, denn ein zentrales EK-Gutachten wird nicht als ausreichend betrachtet. Die Anforderungen an EK-Dokumente und an Gebühren für die Einreichung variieren stark unter allen Mitgliedsstaaten. Zusätzliche Genehmigungen von den Datenschutzbehörden und Versicherungsgesellschaften sind in einigen Ländern einzuholen.Schlussfolgerung: Das Genehmigungsverfahren für multizentrische und multinationale NIS ist zeitaufwendig, vor allem wegen des Mangels an Transparenz und den unterschiedlichen regulatorischen Anforderungen der Mitgliedsstaaten. Die EU-Rechtsvorschriften zur Pharmakovigilanz und die neue EU-Verordnung Nr. 536/2014 über klinische Studien sind zwar ein Schritt nach vorn bei der Schaffung eines Rechtsrahmens für PASS (post-authorisation safety

  6. Mission in the East: The Building of an Army in a Democracy in the New German States

    DTIC Science & Technology

    1994-06-01

    tendency for NV A veterans to deny complicity in the SED regime. Some of them are attempting to rationalize their previous actions in the light of... Hannelore Kaeber and Bernard Tripp (Bonn: Bundeszentrale fuer politische Bildung, 1 984) , p. 261 . 1 2 . Paragraph 8, "Soldatengesetz," p. 26 1

  7. Classification of Complex Nonspeech Sounds. Panel on Classification of Complex Nonspeech Sounds

    DTIC Science & Technology

    1989-04-14

    Society of North America, the Society for Numerical Taxonomy, the British Classification Society, Gesell - schaft fuer Klassification, the Japan...Stevens. £.T. Sandel, and J.B. Arnold 1962 On the learning of speech-like vocabularies. Journal of Verbal Learning and Verbal Behavior 1:133-143. Houtgast

  8. EMC (Electromagnetic Compatibility) Standards Handbook. Revision 4,

    DTIC Science & Technology

    1982-11-01

    Regulations arc prepared EMC November 1982 3-2 STANDARDS HANDBOOK REVISION DATE SECTION-PAGE by VDE Standards Committees (VDE Normen Ausschuss). Individual...regulation has a well- % publicized review that is coordinated with the German Standards Institute (Deutches Institute fuer Normen , DIN) and the German

  9. BKG/DGFI Combination Center Annual Report 2012

    NASA Technical Reports Server (NTRS)

    Bachmann, Sabine; Loesler, Michael; Heinkelmann, Robert; Gerstl, Michael

    2013-01-01

    This report summarizes the activities of the Federal Agency for Cartography and Geodesy (Bundesamt fuer Kartographie und Geodaesie, BKG) and the German Geodetic Research Institute (Deutsches Geodaetisches Forschungsinstitut, DGFI)BKG/DGFI Combination Center in 2011 and outlines the planned activities for the year 2012. The main focus was to stabilize outlier detection and to update the Web presentation of the combined products.

  10. A Model to Transform NATO’s Operational Level Military Capabilities

    DTIC Science & Technology

    2008-05-01

    Dr. Matthias Dembinski leads a project “The International Organization for a Democratic Peace” funded by the German Society for Peace Research...32 Martin Dembinski , Eine Zukunft fuer die NATO, (Frankfurt, Germany: Hessische Stiftung...to restore and maintain the security of the North Atlantic Area. .. .” 34 Dembinski , 5. 35 The EU sees the use of military in the lower end of

  11. Rheological Behavior of Entangled Polystyrene-Polyhedral Oligosilsesquioxane (POSS) Copolymer

    DTIC Science & Technology

    2006-08-24

    and precipitated into 100 mL of methanol. After stirring 1 hour, the copolymer was isolated on fritted glassware and air-dried overnight. 1H NMR...Hesse, W. Z. Zeitschrift fuer Anorganische und Allgemeine Chemie 1926, 156, 245-257. 53 Fulcher, G. S. Journal of the American Ceramic Society

  12. Adsorption of Soluble Silica Species on Alumina Powders and Vice Versa

    DTIC Science & Technology

    2007-11-02

    material, and it shifted more with increasing amounts of dissolved species. Acknowledgement This research was supported by the Army Research Office...Biesheuvel, P. M.; Yu, B. C.; Meinhart , C. D.; Lange, F. F. Zeitschrift fuer Metallkunde 2003, 94, 377-380. (6) Alexander, G. B.; Heston, W. M.; Iler, R. K. J

  13. 22. HISTORIC VIEW OF EARLY TEST STAND IN GERMANY PERHAPS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. HISTORIC VIEW OF EARLY TEST STAND IN GERMANY PERHAPS THE ENGINE IS FOR THE VFR'S (VEREIN FUER RAUMSCHIFFAHRT) 4 STICK REPULSOR. ENGINE IN PHOTOS IS BEING TANKED WITH LOX (NOTICE THE FROST FORMING AT THE BOTTOM OF THE TANK BEHIND THE LADDER. - Marshall Space Flight Center, Redstone Rocket (Missile) Test Stand, Dodd Road, Huntsville, Madison County, AL

  14. Lernen und Lehren von Mathematik-Analysen zum Unterrichtshandeln II - Band 6, IDM-Reihe, Untersuchungen zum Mathematikunterricht. (Learning and Teaching of Mathematics - Analysis of Instructional Actions II - Volume 6, IDM Series, Inquiries into Mathematics Instruction.)

    ERIC Educational Resources Information Center

    Bauersfeld, Heinrich; And Others

    This set of five papers, written in German with abstracts in English, was collected by the Institut fuer Didaktit der Mathematik (Institute for the Teaching of Mathematics) at the University of Bielefeld in West Germany. In the first paper, Bauersfeld considers domains of subjective experiences as the best issue for an interactive theory of…

  15. Educational and Nonprofit Institutions Receiving Prime Contract Awards for RDT&E (Research, Development, Test and Evaluation), Fiscal Year 1981.

    DTIC Science & Technology

    1981-01-01

    SCIENCE & TECH 162 - UNITED KINGDOM MINISTRY OF DEFENCE 2,670 - UN KINGDOM 162 UN KINGDOM 2,670 INSTITUT FUER ATMOSPHAERISCHE 25 - UNIVERSITE RENE ... DESCARTES 10 - GERMANY 25 FRANCE 10 INVERESK RESEARCH INTERNATIONAL 106 - 8,602 UN KINGDOM 106 ISRAEL INSTITUTE OF TECHNOLOGY 55 - ISRAEL 55 KEELE UNIVERSITY

  16. Working Time and the Volume of Work in Germany: The IAB Concept of Measurement. IAB Labour Market Research Topics.

    ERIC Educational Resources Information Center

    Bach, Hans-Uwe; Koch, Susanne

    The Institut fuer Arbeitsmarkt- und Berufsforschung (IAB) or Institute for Employment Research has developed a detailed working time and volume of work measurement concept in order to more comprehensively assess the demand for labor. The individual components of working time in Germany are obtained from various data sources and combined to form…

  17. Controlling and Evaluation of Employment Promotion and the Employment Services in Germany. IAB Labour Market Research Topics No. 36.

    ERIC Educational Resources Information Center

    Brinkmann, Christian

    This paper addresses the emerging evaluation and controlling system of Germany's Bundesanstalt fuer Arbeit, which is responsible for employment promotion. Part 1 discusses changes in employment administration in European countries, a process that has occurred in the Federal Republic of Germany, although most of the basic structures have been…

  18. Modeling the Penetration Behavior of Rigid Into Ballistic Gelatin

    DTIC Science & Technology

    2008-03-01

    CORCELETTE QUEBEC GOA 1R0 CANADA 4 ERNST MACH INSTITUT V HOHL ER E SCHMOLINSKE E SCHNEIDER K THOMA ECKERSTRASSE 4 D-7800...FREIBURG I BR 791 4 GERMANY 3 FRAUNHOFER INSTITUT FUER KURZZEITDYNAMIK ERNST MACH INSTITUT H ROTHENHAEUSLER H SENF E STRASSBURGER

  19. Vaccination of children with a live-attenuated, intranasal influenza vaccine - analysis and evaluation through a Health Technology Assessment.

    PubMed

    Andersohn, Frank; Bornemann, Reinhard; Damm, Oliver; Frank, Martin; Mittendorf, Thomas; Theidel, Ulrike

    2014-01-01

    als auch TIV überlegen (Relative Risikoreduktion – RRR – einer laborbestätigten Influenzainfektion ca. 80% bzw. 50%). Bei Kindern im Alter von >7 bis 17 Jahren mit Asthma ist die Wirksamkeit der Impfung mit LAIV der Impfung mit TIV überlegen (RRR 32%); im Vergleich zu Placebo liegen keine Studien vor. Die Evidenzlage für Kinder >7 bis 17 Jahren mit Asthma ist als moderat einzuschätzen; für Kinder aus der Allgemeinbevölkerung (das heißt Begleiterkrankungen waren kein Einschlusskriterium) lagen keine Studien vor. Angesichts der nachgewiesenen besseren Wirksamkeit von LAIV bei Kindern im Alter von sechs Monaten bis ≤7 Jahren (hohe Evidenz) und der nachgewiesenen besseren Wirksamkeit von LAIV bei Kindern mit Asthma im Alter von >7 bis 17 Jahren (moderate Evidenz) ist LAIV höchstwahrscheinlich auch bei Kindern aus der Allgemeinbevölkerung im Alter von >7 bis 17 Jahren ebenso wirksam (indirekte Evidenz). LAIV war in den eingeschlossenen Studien bei Kindern im Alter von zwei bis 17 Jahren sicher und gut verträglich.In der Mehrzahl der ausgewerteten epidemiologischen Studien zeigte sich LAIV unter Alltagsbedingungen (Effectiveness) als wirksam in der Prävention von Influenza bei Kindern im Alter von zwei bis 17 Jahren. Im Trend war LAIV dabei wirksamer als TIV, was jedoch Methodik bedingt (Beobachtungsstudien) nur eingeschränkt zu bewerten ist. Neben einem direkten Schutzeffekt für die Kinder selbst, konnten bereits bei einer relativ geringen Impfquote auch indirekte Schutzeffekte („Herdenschutz“) bei nichtgeimpften älteren Bevölkerungsgruppen gezeigt werden. In Bezug auf die Sicherheit kann LAIV im Vergleich zu TIV insgesamt als gleichwertig betrachtet werden. Dies gilt auch für die Anwendung bei Kindern mit leichten chronisch-obstruktiven Atemwegserkrankungen, denen daher LAIV nicht vorenthalten werden muss.Aus gesundheitsökonomischer Sicht geht in den bewerteten Studien sowohl die Impfung von Kindern mit Vorerkrankungen als auch die

  20. SU-E-T-102: Determination of Dose Distributions and Water-Equivalence of MAGIC-F Polymer Gel for 60Co and 192Ir Brachytherapy Sources

    SciTech Connect

    Quevedo, A; Nicolucci, P

    2014-06-01

    Purpose: Analyse the water-equivalence of MAGIC-f polymer gel for {sup 60}Co and {sup 192}Ir clinical brachytherapy sources, through dose distributions simulated with PENELOPE Monte Carlo code. Methods: The real geometry of {sup 60} (BEBIG, modelo Co0.A86) and {sup 192}192Ir (Varian, model GammaMed Plus) clinical brachytherapy sources were modelled on PENELOPE Monte Carlo simulation code. The most probable emission lines of photons were used for both sources: 17 emission lines for {sup 192}Ir and 12 lines for {sup 60}. The dose distributions were obtained in a cubic water or gel homogeneous phantom (30 × 30 × 30 cm{sup 3}), with the source positioned in the middle of the phantom. In all cases the number of simulation showers remained constant at 10{sup 9} particles. A specific material for gel was constructed in PENELOPE using weight fraction components of MAGIC-f: wH = 0,1062, wC = 0,0751, wN = 0,0139, wO = 0,8021, wS = 2,58×10{sup −6} e wCu = 5,08 × 10{sup −6}. The voxel size in the dose distributions was 0.6 mm. Dose distribution maps on the longitudinal and radial direction through the centre of the source were used to analyse the water-equivalence of MAGIC-f. Results: For the {sup 60} source, the maximum diferences in relative doses obtained in the gel and water were 0,65% and 1,90%, for radial and longitudinal direction, respectively. For {sup 192}Ir, the maximum difereces in relative doses were 0,30% and 1,05%, for radial and longitudinal direction, respectively. The materials equivalence can also be verified through the effective atomic number and density of each material: Zef-MAGIC-f = 7,07 e .MAGIC-f = 1,060 g/cm{sup 3} and Zef-water = 7,22. Conclusion: The results showed that MAGIC-f is water equivalent, consequently being suitable to simulate soft tissue, for Cobalt and Iridium energies. Hence, gel can be used as a dosimeter in clinical applications. Further investigation to its use in a clinical protocol is needed.

  1. [Relationships between family interactions and pathological internet use in adolescents: an review].

    PubMed

    Wartberg, Lutz; Aden, Anneke; Thomsen, Monika; Thomasius, Rainer

    2015-01-01

    Einleitung: Neben einer generellen Nutzung digitaler Medien durch Kinder und Jugendliche ist in vielen Industrieländern (insbesondere in Asien, Europa und Nordamerika) ein pathologischer Gebrauch des Internets ein Phänomen von wachsender Bedeutung. Aktuellen epidemiologischen Daten zufolge sind in Deutschland Jugendliche häufiger betroffen als Erwachsene. International wurden in verschiedenen Studien Zusammenhänge von familialen Interaktionsmustern und pathologischer Internetnutzung bei Jugendlichen untersucht. Dieser Beitrag gibt eine Übersicht über die aktuell vorliegenden Forschungsbefunde. Methodik: Es erfolgte eine systematische Literaturrecherche in den Datenbanken PubMed, PsycINFO und Psyndex mit festgelegten Schlagwörtern. Ergebnisse: Insgesamt wurden 15 Untersuchungen zu dieser Thematik identifiziert. Es wurden alle Originalarbeiten eingeschlossen, die in englischer oder deutscher Sprache verfasst und in denen ausschließlich minderjährige Untersuchungsteilnehmer befragt worden waren. Funktionalität der Familie, eine gute Kommunikation zwischen Eltern und Kind, eine positive Eltern-Kind-Beziehung sowie unterstützendes elterliches Monitoring vermindern das Risiko einer jugendlichen pathologischen Internetnutzung. Diskussion: Die beschriebenen familialen Prädiktoren wurden in mehreren Studien repliziert. Implikationen für die zukünftige Forschung zu dieser Thematik werden diskutiert.

  2. Rosazea-Management: Update über allgemeine Maßnahmen und topische Therapieoptionen.

    PubMed

    Schaller, M; Schöfer, H; Homey, B; Hofmann, M; Gieler, U; Lehmann, P; Luger, T A; Ruzicka, T; Steinhoff, M

    2016-12-01

    Obwohl bislang für die Rosazea keine kurative Therapie besteht, können verschiedene Optionen zur Behandlung der Symptome und zur Vorbeugung von Exazerbationen empfohlen werden. Neben Selbsthilfemaßnahme wie der Vermeidung von Triggerfaktoren und einer geeigneten Hautpflege sollte das Rosazea-Management bei Patienten mit erythematöser und leichter bis schwerer papulopustulöser Rosazea die Anwendung topischer Präparate als First-Line-Therapie umfassen. Da Überlappungen der charakteristischen Rosazea-Symptome im klinischen Alltag die Regel sind, sollte die medikamentöse Therapie auf die individuellen Symptome zugeschnitten werden; auch eine Kombinationstherapie kann erforderlich sein. Zu den für die Behandlung der Hauptsymptome der Rosazea zugelassenen Wirkstoffen gehören Brimonidin gegen das Erythem sowie Ivermectin, Metronidazol oder Azelainsäure gegen entzündliche Läsionen. Ihre Wirksamkeit wurde in zahlreichen validen, gut kontrollierten Studien belegt. Darüber hinaus existieren verschiedene nicht zugelassene topische Behandlungsmöglichkeiten, deren Wirksamkeit und Sicherheit noch in größeren, kontrollierten Studien zu untersuchen ist.

  3. Zum Stellenwert der Unterdruck-Instillationstherapie in der Dermatologie.

    PubMed

    Müller, Cornelia Sigrid Lissi; Burgard, Barbara; Zimmerman, Monika; Vogt, Thomas; Pföhler, Claudia

    2016-08-01

    Die Methoden zur Behandlung akuter und chronischer Wunden unterliegen einer steten Weiterentwicklung, Reevaluierung und Anwendung innovativer Therapieformen. Die Vakuumtherapie zur Wundbehandlung gehört zu den etablierten Behandlungsmodalitäten. Ein innovatives Verfahren kombiniert die Vakuumtherapie mit der automatisierten, kontrollierten Zufuhr und Drainage wirkstoffhaltiger Lösungen zur topischen Wundbehandlung im Wundbett und auch wirkstofffrei durch Instillation physiologischer Kochsalzlösung (Unterdruck-Instillationstherapie). Hierdurch können die Effekte der konventionellen Vakuumtherapie mit denen der lokalen Antisepsis kombiniert werden. Hierdurch kommt es zu einer Reduktion der Wundfläche, einer Induktion von Granulationsgewebe sowie einer Reduktion der Keimbesiedelung der Wunden. Bisher publizierte Studien konzentrieren sich auf die Anwendung dieses Therapieverfahrens zur Behandlung orthopädisch-chirurgischer Krankheiten. Die Datenlage bezüglich der Vakuum-Instillationstherapie in der Dermatochirurgie beschränkt sich derzeit auf Fallberichte und Einzelfallerfahrungen. Randomisierte, prospektive Studien zum Vergleich der Vakuum-Instillationstherapie zur Behandlung dermatologischer Krankheitsbilder existieren bislang nicht. Ziele des vorliegenden Artikels sind die Vorstellung der Vakuumtherapie mit Instillation einschließlich ihres Wirkprinzips, deren mögliche Komplikationen, die Diskussion erdenklicher Kontraindikationen sowie eine Übersicht über die aktuell verfügbare Datenlage. Zusammenfassend scheint sich die Evidenz zu verdichten, dass mittels Unterdruck-Instillationstherapie sowohl einfache als auch komplizierte Wunden effizient behandelt werden können, was sich in einer deutlichen Beschleunigung der Wundgranulation mit konsekutiv früher möglichem Defektverschluss äußert.

  4. Use of elaborate feedback and an audience-response-system in dental education.

    PubMed

    Rahman, Alexander; Jacker-Guhr, Silke; Staufenbiel, Ingmar; Meyer, Karen; Zupanic, Michaela; Hahnemann, Merle; Lührs, Anne-Katrin; Eberhard, Jörg

    2013-01-01

    Einleitung: Die Studie soll die Frage klären, ob sich durch Anwendung von elaboriertem Feedback und einem Audience-Response-Systems (ARS) der Lernerfolg im Studienfach Zahnerhaltung signifikant verbessert. Methodik: Die Studierenden des 1. klinischen Semesters wurden in eine Studien- und eine Kontrollgruppe randomisiert eingeteilt. Die Randomisierung erfolgte unter Berücksichtigung der Faktoren Alter, Geschlecht und Note im Physikum. Im Verlauf von 10 Vorlesungen wurden pro Vorlesung 5 Multiple-Choice-Fragen zu den formulierten Lernzielen gestellt. Diese wurden unter Anwendung eines ARS von den Studierenden beantwortet. Nur die Studiengruppe erhielt sofort ein elaboriertes Feedback zu den Ergebnissen. Die am Ende durchgeführte Abschlussklausur und Evaluation sollten ermitteln, ob das elaborierte Feedback zu einem Lernerfolg führt und welchen Effekt das ARS auf die Vorlesungsatmosphäre hat. Ergebnisse: Die Ergebnisse der Abschlussklausuren ergaben keinen signifikanten Unterschied zwischen dem Lernerfolg der Studien- und der Kontrollgruppe. Schlussfolgerung: Durch das elaborierte Feedback zeigte sich in dieser Untersuchung kein Unterschied im Lernerfolg. Mit dem ARS ließ sich jedoch eine interaktivere, positivere Lernatmosphäre schaffen.

  5. Application of an adapted Fano cavity test for Monte Carlo simulations in the presence of B-fields.

    PubMed

    de Pooter, J A; de Prez, L A; Bouchard, H

    2015-12-21

    With the advent of MR guided radiotherapy the relevance of Monte Carlo radiation transport simulations in the presence of strong magnetic fields (B-fields) is increasing. While new tests are available to benchmark these simulation algorithms for internal consistency, their application to known codes such as EGSnrc, PENELOPE, and GEANT4 is yet to be provided. In this paper a method is provided to apply the Fano cavity test as a benchmark for a generic implementation of B-field effects in PENELOPE. In addition, it is investigated whether violation of the conditions for the Fano test can partially explain the change in the response of ionization chambers in the presence of strong B-fields. In the present paper it is shown that the condition of isotropy of the secondary particle field (Charged Particle Isotropy, CPI) is an essential requirement to apply the Fano test in the presence of B-fields. Simulations in PENELOPE are performed with (B  =  0.0 T) and (B  =  1.5 T) for cylindrical cavity geometry. The secondary particle field consists of electrons generated from a mono-energetic source (E  =  0.5-4.0 MeV) with a uniform source density and different angular distributions; isotropic, mono-directional, and Compton. In realistic photon fields the secondary radiation field has a non-isotropic angular distribution due to the Compton process. Based on the simulations for the Compton angular distribution (non-CPI), the response change of the cavity model in a uniform radiation field in the presence of B-fields is investigated. For the angular distributions that violate the CPI condition and B  =  1.5 T, the deviations from 1 are considerable, which emphasizes the requirement of CPI. For the isotropic angular distributions obeying this requirement, both the results for B  =  0.0 T and B  =  1.5 T shows deviations from the predictions for E  ⩾  1.5 MeV with values up to 1.0% for E  =  4.0 MeV. Nevertheless

  6. Comment on 'Monte Carlo calculated microdosimetric spread for cell nucleus-sized targets exposed to brachytherapy (125)I and (192)Ir sources and (60)Co cell irradiation'.

    PubMed

    Lindborg, Lennart; Lillhök, Jan; Grindborg, Jan-Erik

    2015-11-07

    The relative standard deviation, σr,D, of calculated multi-event distributions of specific energy for (60)Co ϒ rays was reported by the authors F Villegas, N Tilly and A Ahnesjö (Phys. Med. Biol. 58 6149-62). The calculations were made with an upgraded version of the Monte Carlo code PENELOPE. When the results were compared to results derived from experiments with the variance method and simulated tissue equivalent volumes in the micrometre range a difference of about 50% was found. Villegas et al suggest wall-effects as the likely explanation for the difference. In this comment we review some publications on wall-effects and conclude that wall-effects are not a likely explanation.

  7. NOTE: Monte Carlo simulation of correction factors for IAEA TLD holders

    NASA Astrophysics Data System (ADS)

    Hultqvist, Martha; Fernández-Varea, José M.; Izewska, Joanna

    2010-03-01

    The IAEA standard thermoluminescent dosimeter (TLD) holder has been developed for the IAEA/WHO TLD postal dose program for audits of high-energy photon beams, and it is also employed by the ESTRO-QUALity assurance network (EQUAL) and several national TLD audit networks. Factors correcting for the influence of the holder on the TL signal under reference conditions have been calculated in the present work from Monte Carlo simulations with the PENELOPE code for 60Co γ-rays and 4, 6, 10, 15, 18 and 25 MV photon beams. The simulation results are around 0.2% smaller than measured factors reported in the literature, but well within the combined standard uncertainties. The present study supports the use of the experimentally obtained holder correction factors in the determination of the absorbed dose to water from the TL readings; the factors calculated by means of Monte Carlo simulations may be adopted for the cases where there are no measured data.

  8. New records of three hippoboscid species on newly captured birds from nature in Paraná, Brazil.

    PubMed

    Vaz, Frederico Fontanelli; Teixeira, Valéria Natascha

    2016-01-01

    The aims of this study was to provide new records of hippoboscid flies collected over an one-year period on newly captured birds from nature in the state of Paraná, Brazil. The birds were received by a wildlife center in Tijucas do Sul and the hippoboscid flies were collect by hand or by tweezers, generating a prevalence of 0.7% (16/2232) of parasitized birds. New information about distribution of hippoboscid flies on Asio clamator, Rupornis magnirostris and Athene cunicularia was reported in the state of Paraná. The Caracara plancus, Falco peregrinus and Penelope obscura are new host species for Ornithoctona erythrocephala in the state of Paraná, and the Asio stygius for Icosta rufiventris and Ornithoica vicina in Brazil. This study provided new information about hosts and distribution of hippoboscid flies in Brazilian birds.

  9. Rapid evaluation of particle properties using inverse SEM simulations

    SciTech Connect

    Bekar, Kursat B; Miller, Thomas Martin; Patton, Bruce W; Weber, Charles F

    2017-01-01

    The characteristic X-rays produced by the interactions of the electron beam with the sample in a scanning electron microscope (SEM) are usually captured with a variable-energy detector, a process termed energy dispersive spectrometry (EDS). The purpose of this work is to exploit inverse simulations of SEM-EDS spectra to enable rapid determination of sample properties, particularly elemental composition. This is accomplished using penORNL, a modified version of PENELOPE, and a modified version of the traditional Levenberg Marquardt nonlinear optimization algorithm, which together is referred to as MOZAIK-SEM. The overall conclusion of this work is that MOZAIK-SEM is a promising method for performing inverse analysis of X-ray spectra generated within a SEM. As this methodology exists now, MOZAIK-SEM has been shown to calculate the elemental composition of an unknown sample within a few percent of the actual composition.

  10. Comment on ‘Monte Carlo calculated microdosimetric spread for cell nucleus-sized targets exposed to brachytherapy 125I and 192Ir sources and 60Co cell irradiation’

    NASA Astrophysics Data System (ADS)

    Lindborg, Lennart; Lillhök, Jan; Grindborg, Jan-Erik

    2015-11-01

    The relative standard deviation, σr,D, of calculated multi-event distributions of specific energy for 60Co ϒ rays was reported by the authors F Villegas, N Tilly and A Ahnesjö (Phys. Med. Biol. 58 6149-62). The calculations were made with an upgraded version of the Monte Carlo code PENELOPE. When the results were compared to results derived from experiments with the variance method and simulated tissue equivalent volumes in the micrometre range a difference of about 50% was found. Villegas et al suggest wall-effects as the likely explanation for the difference. In this comment we review some publications on wall-effects and conclude that wall-effects are not a likely explanation.

  11. Dose point kernels in liquid water: an intra-comparison between GEANT4-DNA and a variety of Monte Carlo codes.

    PubMed

    Champion, C; Incerti, S; Perrot, Y; Delorme, R; Bordage, M C; Bardiès, M; Mascialino, B; Tran, H N; Ivanchenko, V; Bernal, M; Francis, Z; Groetz, J-E; Fromm, M; Campos, L

    2014-01-01

    Modeling the radio-induced effects in biological medium still requires accurate physics models to describe the interactions induced by all the charged particles present in the irradiated medium in detail. These interactions include inelastic as well as elastic processes. To check the accuracy of the very low energy models recently implemented into the GEANT4 toolkit for modeling the electron slowing-down in liquid water, the simulation of electron dose point kernels remains the preferential test. In this context, we here report normalized radial dose profiles, for mono-energetic point sources, computed in liquid water by using the very low energy "GEANT4-DNA" physics processes available in the GEANT4 toolkit. In the present study, we report an extensive intra-comparison of profiles obtained by a large selection of existing and well-documented Monte-Carlo codes, namely, EGSnrc, PENELOPE, CPA100, FLUKA and MCNPX.

  12. Silver nanoparticles in X-ray biomedical applications

    NASA Astrophysics Data System (ADS)

    Mattea, Facundo; Vedelago, José; Malano, Francisco; Gomez, Cesar; Strumia, Miriam C.; Valente, Mauro

    2017-01-01

    The fluorescence of silver nanoparticles or ions can be used for detection and dose enhancement purposes in X-ray irradiation applications. This study is focused on the full integration of the chemical synthesis of silver nanoparticles suitable for dosimetric and radiological purposes with characteristics that can be exploited in radiotherapy and radiodiagnostic. A narrow size distribution and a compatible stabilizing agent is often desired in order to obtain homogeneous behaviors in nanoparticle suspension. With the method proposed in this study, nanoparticles ranging from 5 to 20 nm were obtained. The fluorescence of aqueous suspensions of silver nanoparticles has been measured experimentally and simulated with the Monte Carlo PENELOPE code for different silver concentrations and geometrical configurations. Finally, the feasibility of using these nanoparticles for the elaboration of Fricke gel dosimeters has been tested obtaining a dose enhancement when compared with the same material irradiated below the silver K-edge.

  13. Vectorization of the time-dependent Boltzmann transport equation: Application to deep penetration problems

    NASA Astrophysics Data System (ADS)

    Cobos, Agustín C.; Poma, Ana L.; Alvarez, Guillermo D.; Sanz, Darío E.

    2016-10-01

    We introduce an alternative method to calculate the steady state solution of the angular photon flux after a numerical evolution of the time-dependent Boltzmann transport equation (BTE). After a proper discretization the transport equation was converted into an ordinary system of differential equations that can be iterated as a weighted Richardson algorithm. As a different approach, in this work the time variable regulates the iteration process and convergence criteria is based on physical parameters. Positivity and convergence was assessed from first principles and a modified Courant-Friedrichs-Lewy condition was devised to guarantee convergence. The Penelope Monte Carlo method was used to test the convergence and accuracy of our approach for different phase space discretizations. Benchmarking was performed by calculation of total fluence and photon spectra in different one-dimensional geometries irradiated with 60Co and 6 MV photon beams and radiological applications were devised.

  14. Identification and intraspecific genetic diversity of Sarcocystis rileyi from ducks, Anas spp., in Lithuania and Finland.

    PubMed

    Prakas, P; Oksanen, A; Butkauskas, D; Sruoga, A; Kutkienė, L; Švažas, S; Isomursu, M; Liaugaudaitė, S

    2014-10-01

    Macroscopic Sarcocystis cysts were detected in the muscles of 28 Mallards ( Anas platyrhynchos ), 1 Eurasian Wigeon ( Anas penelope ), and 1 Common Teal ( Anas crecca ) hunted in Lithuania and Finland. According to the sequences of the 18S rRNA gene, 28S rRNA gene, and ITS-1 region, the macrocysts examined from all 30 ducks belonged to Sarcocystis rileyi. This parasite was found in the Eurasian Wigeon and the Common Teal for the first time. All S. rileyi isolates examined were identical to each other and differed from 2 S. rileyi isolates previously reported from 2 Mallards from the United States only by 1 nucleotide substitution within the ITS-1 region.

  15. Fricke Gel Dosimeter Tissue-Equivalence a Monte Carlo Study

    NASA Astrophysics Data System (ADS)

    Valente, M.; Bartesaghi, G.; Gambarini, G.; Brusa, D.; Castellano, G.; Carrara, M.

    2008-06-01

    Gel dosimetry has proved to be a valuable technique for absorbed dose distribution measurements in radiotherapy. FriXy-gel dosimeters consist of Fricke (ferrous sulphate) solution infused with xylenol orange. The solution is incorporated to a gel matrix in order to fix it to a solid structure allowing good spatial resolution and is imaged with a transportable optical system, measuring visible light transmittance before and after irradiation. This paper presents an evaluation of total photon mass attenuation coefficients at energies in the range of 50 keV-10MeV for the radiochromic FriXy gel dosimeter sensitive material. Mass attenuation coefficient estimations have been performed by means of Monte Carlo (PENELOPE) simulations. These calculations have been carried out for the FriXy gel sensitive material as well as for soft tissue (ICRU) and pure liquid water; a comparison of the obtained data shows good agreement between the different materials.

  16. Measurement of a 103Pd solution using the TDCR method by LSC.

    PubMed

    Cassette, P; Bé, M M; Jaubert, F; Lépy, M C

    2004-01-01

    Palladium 103 is a radionuclide used in brachytherapy sources for the treatment of prostate cancers and also for other medical applications. It decays through electron capture to excited levels of 103Rh. This paper describes the calculation method used to compute the detection efficiency in the framework of the triple to double coincidence ratio model. The calculation of the energy transferred to the scintillator is made by considering the various atomic events following the electron capture and the electron conversion. The energy deposited in the scintillator after the absorption of X-rays is calculated using the PENELOPE stochastic calculation code. The main contributors to the final uncertainty and their covariance matrix are discussed. As the calculation method cannot be reduced to an explicit function, this paper describes the Monte Carlo method used for the evaluation of uncertainties.

  17. Experimental HPGe coaxial detector response and efficiency compared to Monte Carlo simulations.

    PubMed

    Maidana, Nora L; Vanin, Vito R; García-Alvarez, Juan A; Hermida-López, Marcelino; Brualla, Lorenzo

    2016-02-01

    The peak efficiency for photons hitting the frontal surface of a medium volume n-type HPGe coaxial detector is mapped using acutely collimated beams of energies between 31 and 383 keV from a (133)Ba radioactive source. Simulated values obtained with the Monte Carlo radiation transport code penelope, using a model that respected actual detector dimensions and physical constants while varying dead-layer thicknesses, allowed us to fit the experimental results in the detector bulk but not near its rim. The spectra of a (137)Cs source were measured using the detector shielded from the natural background radiation, with and without a broad angle collimator. The corresponding simulated spectra, using the fitted dead-layer thicknesses, underestimate the continuum component of the spectra and overestimate the peak efficiency, by less than ten percent in the broad angle collimator arrangement. The simulated results are sensitive to the photon attenuation coefficients.

  18. Tritium analysis in titanium films by the BIXS method

    NASA Astrophysics Data System (ADS)

    Zhang, W. G.; Sun, H. W.; Zeng, F. Y.; Mao, L.; Wu, Q. Q.; Zhu, J. J.; An, Z.

    2012-03-01

    In this paper, tritium analyses in titanium films has been carried out by β-decay induced X-ray spectroscopy (BIXS), based on Monte Carlo simulations and the Tikhonov regularization. In our analysis, for the first time the internal bremsstrahlung of tritium β-decay has been taken into account in the BIXS method. Meanwhile, parallel computation using the Monte Carlo code PENELOPE has been realized within the frame of a message passing interface. The tritium depth distributions, surface homogeneity and the total tritium content of the analyzed samples have been obtained. The total tritium contents obtained by the present BIXS method are found to be in good agreement with those obtained by the PVT method.

  19. Calculation of electron Dose Point Kernel in water with GEANT4 for medical application

    SciTech Connect

    Guimaraes, C. C.; Sene, F. F.; Martinelli, J. R.

    2009-06-03

    The rapid insertion of new technologies in medical physics in the last years, especially in nuclear medicine, has been followed by a great development of faster Monte Carlo algorithms. GEANT4 is a Monte Carlo toolkit that contains the tools to simulate the problems of particle transport through matter. In this work, GEANT4 was used to calculate the dose-point-kernel (DPK) for monoenergetic electrons in water, which is an important reference medium for nuclear medicine. The three different physical models of electromagnetic interactions provided by GEANT4 - Low Energy, Penelope and Standard - were employed. To verify the adequacy of these models, the results were compared with references from the literature. For all energies and physical models, the agreement between calculated DPKs and reported values is satisfactory.

  20. Evaluation of bremsstrahlung contribution to photon transport in coupled photon-electron problems

    NASA Astrophysics Data System (ADS)

    Fernández, Jorge E.; Scot, Viviana; Di Giulio, Eugenio; Salvat, Francesc

    2015-11-01

    The most accurate description of the radiation field in x-ray spectrometry requires the modeling of coupled photon-electron transport. Compton scattering and the photoelectric effect actually produce electrons as secondary particles which contribute to the photon field through conversion mechanisms like bremsstrahlung (which produces a continuous photon energy spectrum) and inner-shell impact ionization (ISII) (which gives characteristic lines). The solution of the coupled problem is time consuming because the electrons interact continuously and therefore, the number of electron collisions to be considered is always very high. This complex problem is frequently simplified by neglecting the contributions of the secondary electrons. Recent works (Fernández et al., 2013; Fernández et al., 2014) have shown the possibility to include a separately computed coupled photon-electron contribution like ISII in a photon calculation for improving such a crude approximation while preserving the speed of the pure photon transport model. By means of a similar approach and the Monte Carlo code PENELOPE (coupled photon-electron Monte Carlo), the bremsstrahlung contribution is characterized in this work. The angular distribution of the photons due to bremsstrahlung can be safely considered as isotropic, with the point of emission located at the same place of the photon collision. A new photon kernel describing the bremsstrahlung contribution is introduced: it can be included in photon transport codes (deterministic or Monte Carlo) with a minimal effort. A data library to describe the energy dependence of the bremsstrahlung emission has been generated for all elements Z=1-92 in the energy range 1-150 keV. The bremsstrahlung energy distribution for an arbitrary energy is obtained by interpolating in the database. A comparison between a PENELOPE direct simulation and the interpolated distribution using the data base shows an almost perfect agreement. The use of the data base increases

  1. Retinoblastoma external beam photon irradiation with a special ‘D’-shaped collimator: a comparison between measurements, Monte Carlo simulation and a treatment planning system calculation

    NASA Astrophysics Data System (ADS)

    Brualla, L.; Mayorga, P. A.; Flühs, A.; Lallena, A. M.; Sempau, J.; Sauerwein, W.

    2012-11-01

    Retinoblastoma is the most common eye tumour in childhood. According to the available long-term data, the best outcome regarding tumour control and visual function has been reached by external beam radiotherapy. The benefits of the treatment are, however, jeopardized by a high incidence of radiation-induced secondary malignancies and the fact that irradiated bones grow asymmetrically. In order to better exploit the advantages of external beam radiotherapy, it is necessary to improve current techniques by reducing the irradiated volume and minimizing the dose to the facial bones. To this end, dose measurements and simulated data in a water phantom are essential. A Varian Clinac 2100 C/D operating at 6 MV is used in conjunction with a dedicated collimator for the retinoblastoma treatment. This collimator conforms a ‘D’-shaped off-axis field whose irradiated area can be either 5.2 or 3.1 cm2. Depth dose distributions and lateral profiles were experimentally measured. Experimental results were compared with Monte Carlo simulations’ run with the penelope code and with calculations performed with the analytical anisotropic algorithm implemented in the Eclipse treatment planning system using the gamma test. penelope simulations agree reasonably well with the experimental data with discrepancies in the dose profiles less than 3 mm of distance to agreement and 3% of dose. Discrepancies between the results found with the analytical anisotropic algorithm and the experimental data reach 3 mm and 6%. Although the discrepancies between the results obtained with the analytical anisotropic algorithm and the experimental data are notable, it is possible to consider this algorithm for routine treatment planning of retinoblastoma patients, provided the limitations of the algorithm are known and taken into account by the medical physicist and the clinician. Monte Carlo simulation is essential for knowing these limitations. Monte Carlo simulation is required for optimizing the

  2. SU-C-12A-03: The Impact of Contrast Medium On Radiation Dose in CT: A Systematic Evaluation Across 58 Patient Models

    SciTech Connect

    Sahbaee, P; Samei, E; Segars, W

    2014-06-01

    Purpose: To assess the effect of contrast medium on radiation dose as a function of time via Monte Carlo simulation from the liver CT scan across a library of 5D XCAT models Methods: A validated Monte Carlo simulation package (PENELOPE) was employed to model a CT system (LightSpeed 64 VCT, GE Healthcare). The radiation dose was estimated from a common abdomen CT examination. The dose estimation was performed on a library of adult extended cardiac-torso (5D XCAT) phantoms (35 male, 23 female, mean age 51.5 years, mean weight 80.2 kg). The 5D XCAT models were created based on patient-specific iodine concentration-time results from our computational contrast medium propagation model for different intravenous injection protocols. To enable a dynamic estimation of radiation dose, each organ in the model was assigned to its own time-concentration curve via the PENELOPE package, material.exe. Using the Monte Carlo, for each scan time point after the injection, 80 million photons were initiated and tracked through the phantoms. Finally, the dose to the liver was tallied from the deposited energy. Results: Monte Carlo simulation results of radiation dose delivered to the liver from the XCAT models indicated up to 30% increase in dose for different time after the administration of contrast medium. Conclusion: The contrast enhancement is employed in over 60% of imaging modalities, which not only remarkably affects the CT image quality, but also increases the radiation dose by as much as 70%. The postinjection multiple acquisition in several enhanced CT protocols, makes the radiation dose increment through the use of contrast medium, an inevitable factor in optimization of these protocols. The relationship between radiation dose and injected contrast medium as a function of time studied in this work allows optimization of contrast administration for vulnerable individuals.

  3. Dosimetric quality control of Eclipse treatment planning system using pelvic digital test object

    NASA Astrophysics Data System (ADS)

    Benhdech, Yassine; Beaumont, Stéphane; Guédon, Jeanpierre; Crespin, Sylvain

    2011-03-01

    Last year, we demonstrated the feasibility of a new method to perform dosimetric quality control of Treatment Planning Systems in radiotherapy, this method is based on Monte-Carlo simulations and uses anatomical Digital Test Objects (DTOs). The pelvic DTO was used in order to assess this new method on an ECLIPSE VARIAN Treatment Planning System. Large dose variations were observed particularly in air and bone equivalent material. In this current work, we discuss the results of the previous paper and provide an explanation for observed dose differences, the VARIAN Eclipse (Anisotropic Analytical) algorithm was investigated. Monte Carlo simulations (MC) were performed with a PENELOPE code version 2003. To increase efficiency of MC simulations, we have used our parallelized version based on the standard MPI (Message Passing Interface). The parallel code has been run on a 32- processor SGI cluster. The study was carried out using pelvic DTOs and was performed for low- and high-energy photon beams (6 and 18MV) on 2100CD VARIAN linear accelerator. A square field (10x10 cm2) was used. Assuming the MC data as reference, χ index analyze was carried out. For this study, a distance to agreement (DTA) was set to 7mm while the dose difference was set to 5% as recommended in the TRS-430 and TG-53 (on the beam axis in 3-D inhomogeneities). When using Monte Carlo PENELOPE, the absorbed dose is computed to the medium, however the TPS computes dose to water. We have used the method described by Siebers et al. based on Bragg-Gray cavity theory to convert MC simulated dose to medium to dose to water. Results show a strong consistency between ECLIPSE and MC calculations on the beam axis.

  4. RBE of kV CBCT radiation determined by Monte Carlo DNA damage simulations

    NASA Astrophysics Data System (ADS)

    Kirkby, C.; Ghasroddashti, E.; Poirier, Y.; Tambasco, M.; Stewart, R. D.

    2013-08-01

    Due to the higher LET of kilovoltage (kV) radiation, there is potential for an increase in relative biological effectiveness (RBE) of absorbed doses of radiation from kV cone beam computed tomography (CBCT) sources in reference to megavoltage or Co-60 doses. This work develops a method for accurately coupling a Monte Carlo (MC) radiation transport code (PENELOPE) with the damage simulation (MCDS) to predict relative numbers of DNA double strand breaks (DSBs). The MCDS accounts for slowing down of electrons and delta ray production within the cell nucleus; however, determining the spectrum of electrons incident on the cell nucleus from photons interacting in a larger region of tissue is not trivial. PENELOPE simulations were conducted with a novel tally algorithm invoked where electrons incident on a detection material were tracked and both the incident energy and the final deposited dose were recorded. The DSB yield predicted by a set of MCDS runs of monoenergetic electrons was then looked up in a table and weighted by the specific energy of the incident electron. Our results indicate that the RBE for DSB induction is 1.1 for diagnostic x-rays with energies from 80 to 125 kVp. We found no significant change in RBE with depth or filtration. The predicted absolute DSB yields are about three times lower for cells irradiated under anoxic conditions than the yield in cells irradiated under normoxic (5%) or fully aerobic (100%) conditions. However, oxygen concentration has a negligible (±0.02) effect on the RBE of kV CBCT x-rays.

  5. Monte Carlo simulation of DNA damage induction by x-rays and selected radioisotopes.

    PubMed

    Hsiao, Y; Stewart, R D

    2008-01-07

    To better assess the potential biological consequences of diagnostic x-rays and selected gamma-emitting radioisotopes used in brachytherapy, we used the PENELOPE Monte Carlo radiation transport code to estimate the spectrum of initial electrons produced by photons in single cells and in an irradiation geometry similar to those used in cell culture experiments. We then combined estimates of the initial spectrum of electrons from PENELOPE with DNA damage yields for monoenergetic electrons from the fast Monte Carlo damage simulation (MCDS). The predicted absolute yields (Gbp(-1) Gy(-1)) and RBE values for single-strand break (SSB) and double-strand break (DSB) induction by 220 kVp x-rays are within 1% of the results from detailed track-structure simulations (Friedland et al 1999 Radiat. Environ. Biophys. 38 39). The measured RBE for DSB induction reported by Kühne et al (2005 Radiat. Res. 164 669) for gamma-rays from (60)Co and for 29 kVp x-rays with a 50 microm Rh (mammography) filter are in excellent agreement (1.15 versus 1.16). DSB yields predicted by the MCDS also agree to within 7% with the absolute DSB yields reported by de Lara et al (2001 Radiat. Res. 155 440) and Botchway et al (1997 Radiat. Res. 148 317) for the irradiation of V79 cells by low energy (<2 keV) characteristic x-rays. The predicted RBE for DSB induction by gamma-rays from bare (169)Yb and (131)Cs to (60)Co are 1.06 and 1.14, respectively. Tabulated RBE values for the single-cell and monolayer cell culture geometries differ by at most 15%. The proposed methodology is computationally efficient and may also be useful for the prediction of damage yields for mixtures of other types of charged particles, such as those found in proton therapy, space applications or internal dosimetry.

  6. Comparison of clinical parameters in captive Cracidae fed traditional and extruded diets.

    PubMed

    Candido, Marcus Vinicius; Silva, Louise C C; Moura, Joelma; Bona, Tania D M M; Montiani-Ferreira, Fabiano; Santin, Elizabeth

    2011-09-01

    The Cracidae family of neotropical birds is regarded as one of the most severely threatened in the world. They traditionally have been extensively hunted, and, thus, ex situ efforts for their conservation are recommended and involve the optimization of their care in captivity. Nutrition is a fundamental aspect of husbandry, which influences survival and reproduction in captivity. In this study, a total of 29 animals, including 3 species (Penelope obscura, Penelope superciliaris, and Aburria jacutinga), were subjected to monthly physical examination and blood sampling before and after dietary conversion from the traditional diet of broiler feed, fruits, and vegetables to a nutritionally balanced commercial diet specifically designed for wild Galliformes. The diet change produced differences in several parameters tested, including an increase (P < 0.05) in hemoglobin concentration for all species. Increases (P < 0.05) in erythrocyte count, packed cell volume, and body weight were observed in P. obscura, with a concomitant decrease in the standard deviation for such parameters that show improved uniformity. Globulins and lipase also were reduced (P < 0.05) in P. obscura. Although leukocyte count was lowered and eosinophils were increased in all 3 species after dietary conversion, only these 2 changes were significant (P < 0.05) in P. superciliaris. A. jacutinga had higher (P < 0.05) blood glucose concentrations than the other species, but diet had no effect on this parameter. Blood uric acid concentrations were higher (P < 0.05) after conversion to the commercial diet in P superciliaris. The provision of a commercial extruded diet as a single food source was beneficial, which led to a general improvement in clinical aspects and group uniformity in these 3 species of Cracidae.

  7. When young are more conspicuous than adults: a new ranid species (Anura: Ranidae) revealed by its tadpole.

    PubMed

    Grosjean, Stéphane; Bordoloi, Sabitry; Chuaynkern, Yodchaiy; Chakravarty, Paramita; Ohler, Annemarie

    2015-12-18

    Tadpoles of Clinotarsus alticola collected nearby the type locality in Assam, India are barcoded and described. A detailed morphological and morphometrical description of the specimens, along with a study of the anatomy of the buccal cavity are provided. A comparison of these tadpoles with "Clinotarsus alticola" tadpoles from peninsular Thailand and of the genetic variation of a fragment of their mtDNA 16S gene led us to assign the population of peninsular Thailand to a new species, Clinotarsus penelope sp. n. The holotype of the new species is chosen among the tadpole series as no adult could be found in the type locality. Presumed conspecific adults of nearby localities are morphologically described and compared to barcoded adults of Clinotarsus alticola, waiting for further molecular confirmation. The tadpole of the new species differs from that of C. alticola by a much greater size at comparative stages (e.g., 77.7 mm vs. 53.3 mm in stage 36, respectively), a black coloration (vs. a yellow-olive tinge), several ocelli on the tail muscle (vs. only one), a rounded snout (vs. a more pointed snout) and a different Keratodont Row Formula (KRF; nine keratodonts rows maximum on both labia in C. penelope vs. eight maximum in C. alticola). A discussion about the choice of the holotype, the assignment of adult specimens and the future confirmation of this assignment are provided, as well as a comparison with older descriptions of "Clinotarsus alticola" sensu lato tadpoles and with Clinotarsus curtipes tadpoles from Karnataka, India. The lectotype of Clinotarsus alticola is redescribed.

  8. Interface science of controlled metal/metal and metal/ceramic interfaces prepared using ultrahigh vacuum diffusion bonding

    SciTech Connect

    King, W.E.; Campbell, G.H.; Coombs, A.W.; Johnson, G.W.; Kelly, B.E.; Reitz, T.C.; Stoner, S.L.; Wien, W.L.; Wilson, D.M.

    1993-04-01

    We have designed, constructed, and are operating a capability for production of controlled homophase and heterophase interfaces: an ultrahigh vacuum diffusion bonding machine. This machine is based on a previous design which is operating at the Max Planck Institut fuer Metallforschung, Institut fuer Werkstoffwissenschaft, Stuttgart, FRG. In this method, flat-polished single or polycrystals of materials with controlled surfaced topography can be heat treated up to 1500C in ultrahigh vacuum. Surfaces of annealed samples can be sputter cleaned and characterized prior to bonding. Samples can then be precisely aligned crystallographically to obtain desired grain boundary misorientations. Material couples can then be bonded at temperatures up to 1500C and pressures up to 10 MPa. Results are presented from initial work on Mo grain boundaries and Cu/Al{sub 2}A{sub 3} interfaces.

  9. Exploratory simulations of multiphase effects in gas injection and ventilation tests in an underground rock laboratory

    SciTech Connect

    Finsterle, S. . Versuchsanstalt fuer Wasserbau, Hydrologie und Glaciologie); Schlueter, E.; Pruess, K. )

    1990-06-01

    This report is one of a series documenting the results of the Nagra-DOE Cooperative (NDC-I) research program in which the cooperating scientists explore the geological, geophysical, hydrological, geochemical, and structural effects was sponsored by the US Department of Energy (DOE) through the Lawrence Berkeley Laboratory (LBL) and the Swiss Nationale Genossenschaft fuer die Lagerung radioaktiver Abfaella (Nagra) and concluded in September 1989. 16 refs., 29 figs., 4 tabs.

  10. The NATO Two-Track Decision: The Impact of Public Opinion on Government Policy in the Federal Republic of Germany.

    DTIC Science & Technology

    1984-08-01

    Noelle - Neumann , "The Missile Gap," p. 46. * S 81 the SPD was very careful to emphasize the arms control portion of the decision as its first priority. This...1983), p. 1. 5 3Ibid., p. 3; and Noelle - Neumann , "The Missile Gap," p. 45. 5 4 Wolfgang Wagner, "Der Regierungswechsel in Bonn: Aussenpolitische...fuer Demoskopie Allensbach) was founded in 1947 by Elisabeth Noelle - Neumann and E.P. Neumann . The Institute concentrates on political, scientific

  11. Theoretical and Experimental Analysis of the Constant-Area, Supersonic- Supersonic Ejector

    DTIC Science & Technology

    1976-10-01

    supersoniques," Janrbuch der Wissenschaftlichen Gesell - schaft fuer Luftfahrt, 106-101 (1953). 109. Fondrk, V. V., "Multistage Ejectors for High...Investigation of Ejectors with- I. out Induced Flow," Arnold Engineering Development Center Report No. AFDC-TN-59-14S (1959). 169. Codegone, C...187. Bauer, R. C., and German, R. C., "Some Reynolds Number Effects on the Performance of Ejectors without Induced Flow," Arnold Engineer- ing

  12. Subcontracted R and D final report: analysis of samples obtained from GKT gasification test of Kentucky coal. Nonproprietary version

    SciTech Connect

    Raman, S.V.

    1983-09-01

    A laboratory test program was performed to obtain detailed compositional data on the Gesellshaft fuer Kohle-Technologie (GKT) gasifier feed and effluent streams. GKT performed pilot gasification tests with Kentucky No. 9 coal and collected various samples which were analyzed by GKT and the Radian Corporation, Austin, Texas. The coal chosen had good liquefaction characteristics and a high gasification reactivity. No organic priority pollutants or PAH compounds were detected in the wash water, and solid waste leachates were within RCRA metals limits.

  13. First light of the ESO Laser Guide Star Facility

    NASA Astrophysics Data System (ADS)

    Bonaccini Calia, D.; Allaert, E.; Alvarez, J. L.; Araujo Hauck, C.; Avila, G.; Bendek, E.; Buzzoni, B.; Comin, M.; Cullum, M.; Davies, R.; Dimmler, M.; Guidolin, I.; Hackenberg, W.; Hippler, S.; Kellner, S.; van Kesteren, A.; Koch, F.; Neumann, U.; Ott, T.; Popovic, D.; Pedichini, F.; Quattri, M.; Quentin, J.; Rabien, S.; Silber, A.; Tapia, M.

    2006-06-01

    Two teams of scientists and engineers at Max Planck Institut fuer Extraterrestrische Physik and at the European Southern Observatory have joined forces to design, build and install the Laser Guide Star Facility for the VLT. The Laser Guide Star Facility has now been completed and installed on the VLT Yepun telescope at Cerro Paranal. In this paper we report on the first light and first results from the Commissioning of the LGSF.

  14. Why do - or don't - patients with urinary tract infection participate in a clinical trial? A qualitative study in German family medicine.

    PubMed

    Bleidorn, Jutta; Bucak, Sermin; Gágyor, Ildikó; Hummers-Pradier, Eva; Dierks, Marie-Luise

    2015-01-01

    Hintergrund: Die Durchführung vieler klinischer Studien wird beeinträchtigt durch ungenügenden Patienteneinschluss, nicht zuletzt aufgrund einer nennenswerten Anzahl infrage kommender Patienten, die eine Studienteilnahme ablehnen. Auch wenn Barrieren und motivierende Faktoren für eine Studienteilnahme von Patienten mit onkologischen Erkrankungen oder chronischen Krankheiten bereits untersucht wurden, ist wenig bekannt über die diesbezügliche Einstellung hausärztlicher Patienten, die mit einer unkomplizierten Erkrankung ihren Hausarzt aufsuchen. Die vorliegende Studie hat zum Ziel, Motivationsfaktoren und Barrieren hausärztlicher Patienten für eine Studienteilnahme zu untersuchen, und Faktoren zu identifizieren, die die Patientenrekrutierung in zukünftigen Studien erleichtern. Methode: Diese Studie war eingebettet in eine Arzneimittelstudie, in der zwei Behandlungsstrategien bei Frauen mit unkompliziertem Harnwegsinfekt im hausärztlichen Setting untersucht wurden. Semistrukturierte telefonische Interviews wurden sowohl mit Studienteilnehmerinnen wie auch mit Ablehnerinnen durchgeführt. Der Interviewleitfaden fokussierte auf den persönlichen motivierenden oder hinderlichen Faktoren der Patientinnen. Weitere Aspekte umfassten das Studienthema, die Rolle des Hausarztes, Randomisierung, Studienabläufe und potentielle motivierende/hinderliche Faktoren für andere Patientinnen. Die Analyse der Transskripte erfolgte mittels zusammenfassender qualitativer Inhaltsanalyse.Ergebnisse: 20 Interviews mit Studienteilnehmerinnen und 5 Interviews mit Ablehnerinnen wurden durchgeführt. Die Ergebnisse zeigen unterschiedliche Gründe für eine Studienteilnahme aus den drei Bereichen: persönliche Aspekte, studienbezogene Aspekte und Beziehung zum Hausarzt. Ein relevantes Studienthema und ein wahrgenommener persönlicher Benefit fördert die Studienteilnahme ebenso wie der generelle Wunsch, Forschung zu unterstützen. Die Gewissheit, dass in jedem Fall mit einer

  15. Innovative Aortenklappenimplantation

    NASA Astrophysics Data System (ADS)

    Libera, Paul; Götz, Wolfgang; Schreiber, Christian; Bauernschmitt, Robert; Lange, Rüdiger

    Die Versorgung von degenerierten Herzklappen erlebt zurzeit in mehrfacher Hinsicht einen Wandel: Einerseits lässt die wachsende Zahl von kardiovaskulären Erkrankungen, verbunden mit dem Altern der Bevölkerung, die Zahl der erkrankten Herzklappen ansteigen. Andererseits erwächst mit der neuen Aufsehen erregenden Methode der Katheter gestützten Klappenimplantation am schlagenden Herzen, deren vielversprechender Einsatz im Rahmen verschiedener klinischen Studien zur Zeit untersucht wird, eine Alternative zur traditionellen offenen Herzklappenchirurgie. Offensichtlich stehen wir ganz am Anfang dieser grundlegenden Veränderungen. Das vorliegende Kapitel will die Entwicklung der Katheter gestützten Aortenklappenimplantation bis zum heutigen Tag skizzieren, eine Momentaufnahme aktueller Bestrebungen vermitteln und einen Ausblick wagen, durchaus im Bewusstsein, dass alle diesbezüglichen Ideen, Meinungen und Entwicklungen gegenwärtig im Fluss sind.

  16. [Struggling for normal in an instable situation - informal caregivers self-management in palliative home care. A meta-synthesis].

    PubMed

    Kreyer, Christiane; Pleschberger, Sabine

    2014-10-01

    Hintergrund: Die Betreuung und Pflege von Menschen mit Krebserkrankung am Lebensende zu Hause wird zu einem großen Teil in der Familie geleistet. Dabei sind vor allem pflegende Angehörige stark belastet. Studien die sich mit der Perspektive der Familien in dieser Situation beschäftigen, gehen häufig indirekt auf Selbstmanagementstrategien ein. Diese könnten ein wichtiger Ansatzpunkt für Unterstützungsangebote sein. Ziel: Ziel der Studie ist es, qualitative Forschungsergebnisse zum Selbstmanagement von Familien in der Palliative Care zu Hause zu synthetisieren. Es soll dargestellt werden, wie Familien die Situation erleben und welche Selbstmanagementstrategien sie nutzen. Methode: Eine Metasynthese, die der Methode nach Noblit und Hare (1988) folgte, wurde durchgeführt. Die Ergebnisse von 13 qualitativen Studien aus sechs Ländern wurden einbezogen. Ergebnisse: Die Palliativversorgung eines Menschen mit Krebserkrankung zu Hause kann als instabiler Übergangsprozess verstanden werden, in dessen Verlauf die Familien «um Normalität ringen». Dieser Prozess wird entlang von vier Themen dargestellt. Zudem konnten sechs Selbstmanagementstrategien der Familien identifiziert werden, dies sind das Anerkennen der Situation, die Restrukturierung des Alltags, die Aufrechterhaltung der Balance in den familiären Beziehungen, die Übernahme von Verantwortung, das Nutzen sozialer Unterstützung und der Erwerb von Kompetenzen für Pflege und Betreuung. Schlussfolgerung: Aus den vielfältigen Selbstmanagementstrategien ergeben sich wertvolle Ansätze für die Unterstützung von Angehörigen im Rahmen palliativer Begleitung und Beratung.

  17. [The role of the family in childhood and adolescent binge eating - a systematic review].

    PubMed

    Tetzlaff, Anne; Hilbert, Anja

    2014-01-01

    Fragestellung: Während der Einfluss der Familie bei Anorexia Nervosa und Bulimia Nervosa im Kindes- und Jugendalter belegt ist und bereits in Übersichtsarbeiten zusammengefasst wurde, liegen derzeit wenige Befunde zum Zusammenhang zu Essanfällen ohne kompensatorische Verhaltensweisen vor. Ziel dieser systematischen Übersichtsarbeit ist es daher, familiäre Einflussfaktoren auf die Entstehung und Aufrechterhaltung von Essanfällen zu beschreiben. Methodik: Eine systematische Datenbanksuche für Studien zum Zusammenhang von familiären Faktoren und Essanfällen wurde durchgeführt. Ergebnisse: Die eingeschlossenen Studien zeigten einheitlich, dass eine unsichere Bindung des Kindes, eine geringere Familienfunktionalität und geringere emotionale Unterstützung mit Essanfällen querschnittlich assoziiert sind, elterliche Arbeitslosigkeit sowie elterliche Depressionen retrospektive Korrelate darstellen und weniger Familienmahlzeiten und häufige kritische Kommentare über Figur und Gewicht innerhalb der Familie variable Risikofaktoren für Essanfälle sind. Inkonsistente Befunde fanden sich hingegen bezüglich der Familienstrukturen, dem Vorliegen elterlicher Essstörungen und Diäthalten sowie dem Erkennen von Essanfällen beim eigenen Kind. Geschlechterunterschiede hinsichtlich familiärer Beziehungen und gewichtsbezogener Stigmatisierung wurden identifiziert. Schlussfolgerungen: Ebenso wie bei anderen Essstörungen im Kindes- und Jugendalter spielen familiäre Einflussfaktoren auch bei Essanfällen eine wichtige Rolle. Daher könnten eine Diagnostik familiärer Einflüsse und familientherapeutische Interventionen in der Behandlung von Essanfällen im Kindes- und Jugendalter hilfreich sein. Mithilfe von prospektiven Studiendesigns könnten die divergierenden Ergebnisse aufgeklärt werden.

  18. Effects of enoxaparin and dalteparin on proliferation and migration of patient-derived vascular smooth muscle cells.

    PubMed

    Ellensen, Vegard S; Abrahamsen, Iren; Lorens, James; Jonung, Torbjorn

    2014-03-01

    Hintergrund: Proliferation und Migration sind zwei der wichtigsten Prozesse der Intimahyperplasie und die primäre Ursache von intermediärem und spätem Versagen des vaskulären Graftes. Niedermolekulare Heparine inhibieren diese Prozesse an vaskulären glatten Muskelzellen in Tiermodellen, haben sich jedoch in klinischen Studien nicht bewährt. Dennoch werden sie eingesetzt, um die Intimahyperplasie nach vaskulären Interventionen zu reduzieren. Material und Methoden: Arterielle vaskuläre glatte Muskelzellen, die von Patienten mit Gefässerkrankungen gewonnen wurden, verwendeten wir um die Effekte von Enoxaparin und Dalteparin auf die Proliferation und Migration zu untersuchen und die Signaltransduktion von mitogenaktivierter Proteinkinase-extrazellulärer signalregulierter Kinase (MAPK-ERK) zu beschreiben. Die vaskulären glatten Muskelzellen wurden mit niedermolekularem Heparin in unterschiedlichen Konzentrationen behandelt und durch “image cell enumeration”, Echtzeit Migrations Monitorierung und Flowzytometrie evaluiert. Mit unfraktioniertem Heparin behandelte Serien dienten als positive Kontrolle, und unbehandelte Serien waren die negative Kontrolle. Ergebnisse: Weder Enoxaparin noch Dalteparin beeinflussten die Proliferation und MAPK-ERK-Phosphorylierung. Die Migration wurde durch beide niedermolekularen Heparine leicht reduziert. Unfraktioniertes Heparin zeigte dosisabhängige Effekte, die sich in allen Analysen von denen niedermolekularer Heparine unterschieden. Schlussfolgerungen: Unsere Studie konnte zeigen, dass niedermolekulare Heparine und unfraktioniertes Heparin Unterschiede in der Proliferation und Migration von glatten Muskelzellen bewirken. Eine mögliche Erklärung könnten die beobachteten Unterschiede in der MAPK-ERK-Aktivierung sein. Diese Ergebnisse können die negativen Ergebnisse aus klinischen Studien mit niedermolekularen Heparinen erklären, in denen die Intimahyperplasie nicht verhindert werden konnte und keine verringerte Inzidenz

  19. Basic practical skills teaching and learning in undergraduate medical education - a review on methodological evidence.

    PubMed

    Vogel, Daniela; Harendza, Sigrid

    2016-01-01

    Zielsetzung: Praktische Fertigkeiten sind ein wesentlicher Bestandteil des ärztlichen Arbeitsalltags. Dennoch liegt die Leistung von Absolventen eines Medizinstudiums bei der Durchführung praktischer Basisfertigkeiten häufig unter den erwarteten Anforderungen. Diese Übersichtsarbeit verfolgt daher das Ziel, Lehrmethoden für medizinische Basisfertigkeiten im Medizinstudium zu identifizieren und zusammenzufassen, die einen evidenzbasierten Nachweis für das effektive studentische Lernen dieser Fertigkeiten erbringen. Methoden: Praktische Basisfertigkeiten wurden als Basisfertigkeiten der körperlichen Untersuchung, Routinefertigkeiten, die im Laufe der Praxis besser werden, und als Fertigkeiten, die auch vom Pflegepersonal übernommen werden, definiert. PubMed wurde mit verschiedenen Begriffen durchsucht, die diese praktischen Basisfertigkeiten beschreiben. Insgesamt wurden 3467 identifizierte Publikationen gesichtet und 205 wurden schließlich auf ihre Eignung geprüft. Ergebnisse: 43 Studien, die mindestens eine praktische Basisfertigkeit, einen Vergleich zweier Gruppen von Medizinstudierenden und Wirkungen auf die studentische Leistung beinhalteten, wurden analysiert. Sieben praktische Basisfertigkeiten und 15 verschiedene Lehrmethoden konnten identifiziert werden. Die konsistentesten Ergebnisse in Bezug auf effektive Lehre und den Erwerb von praktischen Basisfertigkeiten wurden für strukturiertes Fertigkeitentraining, Feedback und selbstgesteuertes Lernen gefunden. Simulation war mit spezifischen Lehrmethoden wirksam und in mehreren Studien fanden sich keine Unterschiede in Bezug auf Lehreffekte zwischen Experten oder Peers als Lehrende. Multimedia-gestützte Instruktion zeigte bei Anwendung in geeignetem Rahmen ebenfalls positive Effekte für das Erlernen praktischer Basisfertigkeiten. Fazit: Eine Kombination von freiwilligem oder obligatorischem Selbststudium mit Multimedia-gestützten Anwendungen wie Video-Clips in Kombination mit einem strukturierten

  20. Bowtie filters for dedicated breast CT: Analysis of bowtie filter material selection

    SciTech Connect

    Kontson, Kimberly Jennings, Robert J.

    2015-09-15

    Purpose: For a given bowtie filter design, both the selection of material and the physical design control the energy fluence, and consequently the dose distribution, in the object. Using three previously described bowtie filter designs, the goal of this work is to demonstrate the effect that different materials have on the bowtie filter performance measures. Methods: Three bowtie filter designs that compensate for one or more aspects of the beam-modifying effects due to the differences in path length in a projection have been designed. The nature of the designs allows for their realization using a variety of materials. The designs were based on a phantom, 14 cm in diameter, composed of 40% fibroglandular and 60% adipose tissue. Bowtie design #1 is based on single material spectral matching and produces nearly uniform spectral shape for radiation incident upon the detector. Bowtie design #2 uses the idea of basis-material decomposition to produce the same spectral shape and intensity at the detector, using two different materials. With bowtie design #3, it is possible to eliminate the beam hardening effect in the reconstructed image by adjusting the bowtie filter thickness so that the effective attenuation coefficient for every ray is the same. Seven different materials were chosen to represent a range of chemical compositions and densities. After calculation of construction parameters for each bowtie filter design, a bowtie filter was created using each of these materials (assuming reasonable construction parameters were obtained), resulting in a total of 26 bowtie filters modeled analytically and in the PENELOPE Monte Carlo simulation environment. Using the analytical model of each bowtie filter, design profiles were obtained and energy fluence as a function of fan-angle was calculated. Projection images with and without each bowtie filter design were also generated using PENELOPE and reconstructed using FBP. Parameters such as dose distribution, noise uniformity

  1. SU-D-213-01: Transparent Photon Detector For The Online Monitoring Of IMRT Beams

    SciTech Connect

    Delorme, R; Arnoud, Y; Fabbro, R; Boyer, B; Rossetto, O; Gallin-Martel, L; Gallin-Martel, M; Pelissier, A; Fonteille, I

    2015-06-15

    Purpose: An innovative Transparent Detector for Radiotherapy (TraDeRa) has been developed. The detector aims at real-time monitoring of modulated beam ahead of the patient during delivery sessions, with a field cover up to 40×40 cm {sup 2}. Methods: TraDeRa consists in a pixelated matrix of ionization chambers with a patented electrodes design. An in-house designed specific integrated circuit allows to extract the signal and provides a real-time map of beam intensity and shape, at the linac pulse-scale. The measurements under irradiation are made with a 6 MV clinical X-Ray beam. Dose calculations are performed with the Monte Carlo code PENELOPE, modeling the full accelerator head and the TraDeRa detector. Results: A 2 % attenuation of the beam was measured in the presence of TraDeRa and the PENELOPE dosimetric study showed no significant modification of the photon beam properties. TraDeRa detects error leaf position as small as 1 mm compared to a reference field, for both static and modulated fields. In addition, measurements are accurate over a large dynamic range from low intensity signals, as inter-leaves leaks, to very high intensities as obtained on the medical line of the European Synchrotron Radiation Facility. The detector is fully operational for conventional and high dose rate beams as FFF modes (up to 2400 MU/min). Conclusion: The current version of TraDeRa shows promising results for IMRT quality assurance (QA), allowing pulse-scale monitoring of the beam and high sensitivity for errors detection. The attenuation is small enough not to hinder the irradiation while keeping the beam upstream of the patient under constant control. A final prototype under development will include 1600 independent electrodes, half of them with a high resolution centered on the beam axis. This compact detector provides an independent set of measurements for a better QA. Funding support : This work was supported by the LABEX PRIMES (ANR-11-LABX-0063) of Universite de Lyon

  2. Radial secondary electron dose profiles and biological effects in light-ion beams based on analytical and Monte Carlo calculations using distorted wave cross sections.

    PubMed

    Wiklund, Kristin; Olivera, Gustavo H; Brahme, Anders; Lind, Bengt K

    2008-07-01

    To speed up dose calculation, an analytical pencil-beam method has been developed to calculate the mean radial dose distributions due to secondary electrons that are set in motion by light ions in water. For comparison, radial dose profiles calculated using a Monte Carlo technique have also been determined. An accurate comparison of the resulting radial dose profiles of the Bragg peak for (1)H(+), (4)He(2+) and (6)Li(3+) ions has been performed. The double differential cross sections for secondary electron production were calculated using the continuous distorted wave-eikonal initial state method (CDW-EIS). For the secondary electrons that are generated, the radial dose distribution for the analytical case is based on the generalized Gaussian pencil-beam method and the central axis depth-dose distributions are calculated using the Monte Carlo code PENELOPE. In the Monte Carlo case, the PENELOPE code was used to calculate the whole radial dose profile based on CDW data. The present pencil-beam and Monte Carlo calculations agree well at all radii. A radial dose profile that is shallower at small radii and steeper at large radii than the conventional 1/r(2) is clearly seen with both the Monte Carlo and pencil-beam methods. As expected, since the projectile velocities are the same, the dose profiles of Bragg-peak ions of 0.5 MeV (1)H(+), 2 MeV (4)He(2+) and 3 MeV (6)Li(3+) are almost the same, with about 30% more delta electrons in the sub keV range from (4)He(2+)and (6)Li(3+) compared to (1)H(+). A similar behavior is also seen for 1 MeV (1)H(+), 4 MeV (4)He(2+) and 6 MeV (6)Li(3+), all classically expected to have the same secondary electron cross sections. The results are promising and indicate a fast and accurate way of calculating the mean radial dose profile.

  3. Development of a phantom to validate high-dose-rate brachytherapy treatment planning systems with heterogeneous algorithms

    SciTech Connect

    Moura, Eduardo S.; Rostelato, Maria Elisa C. M.; Zeituni, Carlos A.

    2015-04-15

    Purpose: This work presents the development of a phantom to verify the treatment planning system (TPS) algorithms used for high-dose-rate (HDR) brachytherapy. It is designed to measure the relative dose in a heterogeneous media. The experimental details used, simulation methods, and comparisons with a commercial TPS are also provided. Methods: To simulate heterogeneous conditions, four materials were used: Virtual Water™ (VM), BR50/50™, cork, and aluminum. The materials were arranged in 11 heterogeneity configurations. Three dosimeters were used to measure the relative response from a HDR {sup 192}Ir source: TLD-100™, Gafchromic{sup ®} EBT3 film, and an Exradin™ A1SL ionization chamber. To compare the results from the experimental measurements, the various configurations were modeled in the PENELOPE/penEasy Monte Carlo code. Images of each setup geometry were acquired from a CT scanner and imported into BrachyVision™ TPS software, which includes a grid-based Boltzmann solver Acuros™. The results of the measurements performed in the heterogeneous setups were normalized to the dose values measured in the homogeneous Virtual Water™ setup and the respective differences due to the heterogeneities were considered. Additionally, dose values calculated based on the American Association of Physicists in Medicine-Task Group 43 formalism were compared to dose values calculated with the Acuros™ algorithm in the phantom. Calculated doses were compared at the same points, where measurements have been performed. Results: Differences in the relative response as high as 11.5% were found from the homogeneous setup when the heterogeneous materials were inserted into the experimental phantom. The aluminum and cork materials produced larger differences than the plastic materials, with the BR50/50™ material producing results similar to the Virtual Water™ results. Our experimental methods agree with the PENELOPE/penEasy simulations for most setups and dosimeters. The

  4. Air-kerma strength determination of a miniature x-ray source for brachytherapy applications

    NASA Astrophysics Data System (ADS)

    Davis, Stephen D.

    A miniature x-ray source has been developed by Xoft Inc. for high dose-rate brachytherapy treatments. The source is contained in a 5.4 mm diameter water-cooling catheter. The source voltage can be adjusted from 40 kV to 50 kV and the beam current is adjustable up to 300 muA. Electrons are accelerated toward a tungsten-coated anode to produce a lightly-filtered bremsstrahlung photon spectrum. The sources were initially used for early-stage breast cancer treatment using a balloon applicator. More recently, Xoft Inc. has developed vaginal and surface applicators. The miniature x-ray sources have been characterized using a modification of the American Association of Physicists in Medicine Task Group No. 43 formalism normally used for radioactive brachytherapy sources. Primary measurements of air kerma were performed using free-air ionization chambers at the University of Wisconsin (UW) and the National Institute of Standards and Technology (NIST). The measurements at UW were used to calibrate a well-type ionization chamber for clinical verification of source strength. Accurate knowledge of the emitted photon spectrum was necessary to calculate the corrections required to determine air-kerma strength, defined in vacuo. Theoretical predictions of the photon spectrum were calculated using three separate Monte Carlo codes: MCNP5, EGSnrc, and PENELOPE. Each code used different implementations of the underlying radiological physics. Benchmark studies were performed to investigate these differences in detail. The most important variation among the codes was found to be the calculation of fluorescence photon production following electron-induced vacancies in the L shell of tungsten atoms. The low-energy tungsten L-shell fluorescence photons have little clinical significance at the treatment distance, but could have a large impact on air-kerma measurements. Calculated photon spectra were compared to spectra measured with high-purity germanium spectroscopy systems at both UW and

  5. Evaluation of computational models and cross sections used by MCNP6 for simulation of characteristic X-ray emission from thick targets bombarded by kiloelectronvolt electrons

    NASA Astrophysics Data System (ADS)

    Poškus, A.

    2016-09-01

    This paper evaluates the accuracy of the single-event (SE) and condensed-history (CH) models of electron transport in MCNP6.1 when simulating characteristic Kα, total K (=Kα + Kβ) and Lα X-ray emission from thick targets bombarded by electrons with energies from 5 keV to 30 keV. It is shown that the MCNP6.1 implementation of the CH model for the K-shell impact ionization leads to underestimation of the K yield by 40% or more for the elements with atomic numbers Z < 15 and overestimation of the Kα yield by more than 40% for the elements with Z > 25. The Lα yields are underestimated by more than an order of magnitude in CH mode, because MCNP6.1 neglects X-ray emission caused by electron-impact ionization of L, M and higher shells in CH mode (the Lα yields calculated in CH mode reflect only X-ray fluorescence, which is mainly caused by photoelectric absorption of bremsstrahlung photons). The X-ray yields calculated by MCNP6.1 in SE mode (using ENDF/B-VII.1 library data) are more accurate: the differences of the calculated and experimental K yields are within the experimental uncertainties for the elements C, Al and Si, and the calculated Kα yields are typically underestimated by (20-30)% for the elements with Z > 25, whereas the Lα yields are underestimated by (60-70)% for the elements with Z > 49. It is also shown that agreement of the experimental X-ray yields with those calculated in SE mode is additionally improved by replacing the ENDF/B inner-shell electron-impact ionization cross sections with the set of cross sections obtained from the distorted-wave Born approximation (DWBA), which are also used in the PENELOPE code system. The latter replacement causes a decrease of the average relative difference of the experimental X-ray yields and the simulation results obtained in SE mode to approximately 10%, which is similar to accuracy achieved with PENELOPE. This confirms that the DWBA inner-shell impact ionization cross sections are significantly more

  6. Treatment planning considerations in contrast-enhanced radiotherapy: energy and beam aperture optimization.

    PubMed

    Garnica-Garza, H M

    2011-01-21

    It has been shown that the use of kilovoltage x-rays in conjunction with a contrast agent incorporated into the tumor can lead to acceptable treatment plans with regard to the absorbed dose distribution produced in the target as well as in the tissue and organs at risk surrounding it. In this work, several key aspects related to the technology and irradiation techniques necessary to clinically implement this treatment modality are addressed by means of Monte Carlo simulation. The Zubal phantom was used to model a prostate radiotherapy treatment, a challenging site due to the depth of the prostate and the presence of bony structures that must be traversed by the x-ray beam on its way to the target. It is assumed that the concentration levels of the enhancing agent present in the tumor are at or below 10 mg per 1 g of tissue. The Monte Carlo code PENELOPE was used to model a commercial x-ray tube having a tungsten target. X-ray energy spectra for several combinations of peak electron energy and added filtration were obtained. For each energy spectrum, a treatment plan was calculated, with the PENELOPE Monte Carlo code, by modeling the irradiation of the patient as 72 independent conformal beams distributed at intervals of 5° around the phantom in order to model a full x-ray source rotation. The Cimmino optimization algorithm was then used to find the optimum beam weight and energy for different treatment strategies. It is shown that for a target dose prescription of 72 Gy covering the whole tumor, the maximum rectal wall and bladder doses are kept below 52 Gy for the largest concentration of contrast agent of 10 mg per 1 g of tissue. It is also shown that concentrations of as little as 5 mg per 1 g of tissue also render dose distributions with excellent sparing of the organs at risk. A treatment strategy to address the presence of non-uniform distributions of the contrast agent in the target is also modeled and discussed.

  7. Spectral radiance calibrations between 165-300 nm - An interlaboratory comparison

    NASA Technical Reports Server (NTRS)

    Bridges, J. M.; Ott, W. R.; Pitz, E.; Schulz, A.; Einfeld, D.; Stuck, D.

    1977-01-01

    The spectral radiance of deuterium lamps calibrated by the Max-Planck-Institut fuer Astronomie (MPI), by the U.S. National Bureau of Standards (NBS), and by the Physikalisch-Technische Bundesanstalt (PTB) are compared to check the agreement of UV radiometric scales. The NBS group used the optically thin continuum radiation from a wall-stabilized hydrogen arc as its fundamental radiometric standard, while the MPI and PTB groups used the synchrotron radiation facility in DESY. It is found that the spectral radiance scales based upon the DESY synchrotron and the NBS hydrogen arc are consistent, at least for one wavelength relative to another.

  8. STORAGE RING MEASUREMENT OF ELECTRON IMPACT IONIZATION FOR Mg{sup 7+} FORMING Mg{sup 8+}

    SciTech Connect

    Hahn, M.; Lestinsky, M.; Novotny, O.; Savin, D. W.; Bernhardt, D.; Mueller, A.; Schippers, S.; Wolf, A.

    2010-04-01

    We report electron impact ionization cross section measurements for Mg{sup 7+} forming Mg{sup 8+} at center of mass energies from approximately 200 eV to 2000 eV. The experimental work was performed using the heavy-ion storage ring TSR located at the Max-Planck-Institut fuer Kernphysik in Heidelberg, Germany. We find good agreement with distorted wave calculations using both the GIPPER code of the Los Alamos Atomic Physics Code suite and using the Flexible Atomic Code.

  9. Radioactive waste disposal in Germany: no site decision - Keeping competence

    SciTech Connect

    Kienzler, Bernhard; Geckeis, Horst; Gompper, Klaus; Klenze, Reinhardt

    2007-07-01

    The research programme of the Institut fuer Nukleare Entsorgung (INE) at the Forschungszentrum Karlsruhe is dedicated to elaborate the fundamental understanding of radionuclide/actinide interactions with various components of the groundwater and with the relevant host rock materials at disposal relevant trace concentrations. INE's research programme was not biased after enactment of the Gorleben moratorium in 2001. This paper presents current R and D with respect to application in performance assessment/safety case of nuclear waste disposal. Focus is given to the leading role of the institute in various projects within EU framework programmes. (authors)

  10. Development of Fracture Mechanics Maps for Composite Materials. Volume 3.

    DTIC Science & Technology

    1985-12-01

    RD-At69 W4 DEVELOPMENT OF FRCTURE ECHNICS NPS FOR COMPOSITE V3jMATERIALS VOLUME 3( ) DEUTSCHE FORSCHUNOS- UND YERSUCHSANSTALT FUER LUFT- UND RAUMF...ungekerbter CFK -Laminate J.- Block DFVLR 4 Institut~~ ~ firSrutrecai Braunschweig le- DEUTSCHE ~~~~~*~ FOSHUG-UN ERUHA:TL Y FOR LUFT- UND RAUMFAHRT E.V...Laminaten mittels Schallemissionsanalyse e Braunschweig, den 15.11.1984 Der Bericht umfal~t-:-:. 32 Seiten mit . %. * 14 Bildern und 1 Anhang Institutsleiter

  11. S-Layer Based Bio-Imprinting - Synthetic S-Layer Polymers

    DTIC Science & Technology

    2015-07-09

    AFRL-OSR-VA-TR-2015-0161 S-Layer Based Bio-Imprinting - Synthetic S-Layer Polymers Dietmar Pum ZENTRUM FUER NANOBIOTECHNOLOGIE Final Report 07/09...COVERED (From - To)      01-06-2012 to 31-05-2015 4.  TITLE AND SUBTITLE S-Layer Based Bio-Imprinting - Synthetic S-Layer Polymers 5a.  CONTRACT...the reassembled S-layer protein lattice. The start of the project focused on the selection, composition and chemical modification of suitable polymers

  12. Roentgensatellit (ROSAT)

    NASA Technical Reports Server (NTRS)

    Guckenbiehl, F.; Ousley, G. W., Sr.

    1991-01-01

    The DSN (Deep Space Network) mission support requirements for ROSAT (Roentgensatellit) are summarized. ROSAT is an international cooperative program between NASA and the Bundesministerium fuer Forschung and Technologie (BMFT). The satellite was launched on a Delta 2 vehicle and placed in a circular orbit at an altitude of 580 km, with a 53-deg inclination. The mission objectives are outlined and the DSN support requirements are defined through the presentation of tables and narratives describing the spacecraft flight profile; DSN support coverage; frequency assignments; support parameters for telemetry and command; and tracking support responsibility.

  13. Multi-Model Ensemble Wake Vortex Prediction

    NASA Technical Reports Server (NTRS)

    Koerner, Stephan; Holzaepfel, Frank; Ahmad, Nash'at N.

    2015-01-01

    Several multi-model ensemble methods are investigated for predicting wake vortex transport and decay. This study is a joint effort between National Aeronautics and Space Administration and Deutsches Zentrum fuer Luft- und Raumfahrt to develop a multi-model ensemble capability using their wake models. An overview of different multi-model ensemble methods and their feasibility for wake applications is presented. The methods include Reliability Ensemble Averaging, Bayesian Model Averaging, and Monte Carlo Simulations. The methodologies are evaluated using data from wake vortex field experiments.

  14. Monte Carlo simulation of the Leksell Gamma Knife®: II. Effects of heterogeneous versus homogeneous media for stereotactic radiosurgery

    NASA Astrophysics Data System (ADS)

    Moskvin, Vadim; Timmerman, Robert; DesRosiers, Colleen; Randall, Marcus; DesRosiers, Paul; Dittmer, Phil; Papiez, Lech

    2004-11-01

    The absence of electronic equilibrium in the vicinity of bone-tissue or air-tissue heterogeneity in the head can misrepresent deposited dose with treatment planning algorithms that assume all treatment volume as homogeneous media. In this paper, Monte Carlo simulation (PENELOPE) and measurements with a specially designed heterogeneous phantom were applied to investigate the effect of air-tissue and bone-tissue heterogeneity on dose perturbation with the Leksell Gamma Knife®. The dose fall-off near the air-tissue interface caused by secondary electron disequilibrium leads to overestimation of dose by the vendor supplied treatment planning software (GammaPlan®) at up to 4 mm from an interface. The dose delivered to the target area away from an air-tissue interface may be underestimated by up to 7% by GammaPlan® due to overestimation of attenuation of photon beams passing through air cavities. While the underdosing near the air-tissue interface cannot be eliminated with any plug pattern, the overdosage due to under-attenuation of the photon beams in air cavities can be eliminated by plugging the sources whose beams intersect the air cavity. Little perturbation was observed next to bone-tissue interfaces. Monte Carlo results were confirmed by measurements. This study shows that the employed Monte Carlo treatment planning is more accurate for precise dosimetry of stereotactic radiosurgery with the Leksell Gamma Knife® for targets in the vicinity of air-filled cavities.

  15. Magnetic field effects on the energy deposition spectra of MV photon radiation.

    PubMed

    Kirkby, C; Stanescu, T; Fallone, B G

    2009-01-21

    Several groups worldwide have proposed various concepts for improving megavoltage (MV) radiotherapy that involve irradiating patients in the presence of a magnetic field-either for image guidance in the case of hybrid radiotherapy-MRI machines or for purposes of introducing tighter control over dose distributions. The presence of a magnetic field alters the trajectory of charged particles between interactions with the medium and thus has the potential to alter energy deposition patterns within a sub-cellular target volume. In this work, we use the MC radiation transport code PENELOPE with appropriate algorithms invoked to incorporate magnetic field deflections to investigate electron energy fluence in the presence of a uniform magnetic field and the energy deposition spectra within a 10 microm water sphere as a function of magnetic field strength. The simulations suggest only very minor changes to the electron fluence even for extremely strong magnetic fields. Further, calculations of the dose-averaged lineal energy indicate that a magnetic field strength of at least 70 T is required before beam quality will change by more than 2%.

  16. Serosurveillance for Japanese encephalitis virus in wild birds captured in Korea.

    PubMed

    Yang, Dong-Kun; Oh, Yoon-I; Kim, Hye-Ryoung; Lee, Youn-Jeong; Moon, Oun-Kyong; Yoon, Hachung; Kim, Byounghan; Lee, Kyung-Woo; Song, Jae-Young

    2011-12-01

    Climate change induced by recent global warming may have a significant impact on vector-borne and zoonotic diseases. For example, the distribution of Japanese encephalitis virus (JEV) has expanded into new regions. We surveyed the levels of hemagglutination-inhibition (HI) antibodies against JEV (Family Flaviviridae, genus Flavivirus) in wild birds captured in Korea. Blood samples were collected from 1,316 wild birds including the following migratory birds: Oceanodroma castro (n = 4), Anas formosa (n = 7), Anas penelope (n = 20), Fulica atra (n = 30), Anas acuta (n = 89), Anas crecca (n = 154), Anas platyrhynchos (n = 214), Aix galericulata (n = 310), and Anas poecilorhyncha (n = 488). All were captured in 16 locations in several Korea provinces between April 2007 and December 2009. Out of the 1,316 serum samples tested, 1,141 (86.7%) were positive for JEV. Wild birds captured in 2009 had a higher seroprevalence of ant-JEV antibodies than those captured in 2007. Wild birds with an HI antibody titer of 1 : 1,280 or higher accounted for 21.2% (280/1,316) of the animals tested. These findings indicated that wild birds from the region examined in our study have been exposed to JEV and may pose a high risk for introducing a new JEV genotype into Korea.

  17. Exploring the Written Dialogues of Two First-Year Secondary Science Teachers in an Online Mentoring Program

    NASA Astrophysics Data System (ADS)

    Bang, EunJin; Luft, Julie A.

    2014-02-01

    This study explored the yearlong learning processes of two first-year secondary science teachers participating in an online mentoring program, through examination of their written dialogues within the program and other data. Using a case study method, this study (a) explored the patterns of written dialogues between the two new teachers and their mentors over the course of a year, (b) documented pertinent topics of importance, and finally (c) illustrated the new realities created in the mentees' classrooms as a result of the online mentoring process. Penelope and Bradley, who taught at an urban school and at a suburban school respectively, were selected as subjects. Our analysis revealed that the two pairs of mentee-mentors showed different participation patterns that affected the intensity of the creation of new realities, and affected whether the mentees tried/vetted new teaching practices suggested by their mentors. Yet, analysis also revealed that certain elements in the written dialogues between pairs were found to be similar, in that construction of knowledge was evident between both pairs when friction developed and appropriate teamwork emerged to deal with it. The topics of greatest interest and importance within the dialogues were those related to the logistics of the school system and the processes and methodologies of teaching. These results suggest that online mentoring programs are an effective dialogical tool for transferring the knowledge of experts to novices, and for thus expediting the professional induction and growth of new science teachers.

  18. Bremsstrahlung enhancement in electron probe microanalysis for homogeneous samples using Monte Carlo simulation.

    PubMed

    Petaccia, M; Segui, S; Castellano, G

    2016-11-01

    Fluorescence enhancement in samples irradiated in a scanning electron microscope or an electron microprobe should be appropriately assessed in order not to distort quantitative analyses. Several models have been proposed to take into account this effect and current quantification routines are based on them, many of which have been developed under the assumption that bremsstrahlung fluorescence correction is negligible when compared to characteristic enhancement; however, no concluding arguments have been provided in order to support this assumption. As detectors are unable to discriminate primary from secondary characteristic X-rays, Monte Carlo simulation of radiation transport becomes a determinant tool in the study of this fluorescence enhancement. In this work, bremsstrahlung fluorescence enhancement in electron probe microanalysis has been studied by using the interaction forcing routine offered by penelope 2008 as a variance reduction alternative. The developed software allowed us to show that bremsstrahlung and characteristic fluorescence corrections are in fact comparable in the studied cases. As an extra result, the interaction forcing approach appears as a most efficient method, not only in the computation of the continuum enhancement but also for the assessment of the characteristic fluorescence correction.

  19. Monte Carlo Simulation of Characteristic Secondary Fluorescence in Electron Probe Microanalysis of Homogeneous Samples Using the Splitting Technique.

    PubMed

    Petaccia, Mauricio; Segui, Silvina; Castellano, Gustavo

    2015-06-01

    Electron probe microanalysis (EPMA) is based on the comparison of characteristic intensities induced by monoenergetic electrons. When the electron beam ionizes inner atomic shells and these ionizations cause the emission of characteristic X-rays, secondary fluorescence can occur, originating from ionizations induced by X-ray photons produced by the primary electron interactions. As detectors are unable to distinguish the origin of these characteristic X-rays, Monte Carlo simulation of radiation transport becomes a determinant tool in the study of this fluorescence enhancement. In this work, characteristic secondary fluorescence enhancement in EPMA has been studied by using the splitting routines offered by PENELOPE 2008 as a variance reduction alternative. This approach is controlled by a single parameter NSPLIT, which represents the desired number of X-ray photon replicas. The dependence of the uncertainties associated with secondary intensities on NSPLIT was studied as a function of the accelerating voltage and the sample composition in a simple binary alloy in which this effect becomes relevant. The achieved efficiencies for the simulated secondary intensities bear a remarkable improvement when increasing the NSPLIT parameter; although in most cases an NSPLIT value of 100 is sufficient, some less likely enhancements may require stronger splitting in order to increase the efficiency associated with the simulation of secondary intensities.

  20. Assessment of radiotherapy photon beams: A practical and low cost methodology

    NASA Astrophysics Data System (ADS)

    Reis, C. Q. M.; Nicolucci, P.

    2017-02-01

    Dosimetric properties of radiation beams used in radiotherapy are directly related to the energy spectrum produced by the treatment unit. Therefore, the development of methodologies to evaluate in a simple and accurate way the spectra of clinical beams can help establishing the quality control of the treatment. The purpose of this study is to present a practical and low cost methodology for determining primary spectra of radiotherapy photon beams from transmission measurements in attenuators of aluminum and using the method of the inverse Laplace transform. Monte Carlo simulation with PENELOPE code was used in order to evaluate and validate the reconstructed spectra by the calculation of dosimetric parameters that characterize the beam. Percentage depth dose values simulated with a 6 MV reconstructed spectrum shows maximum difference of 4.4% when compared to values measured at the corresponding clinical beam. For a 10 MV beam that difference was around 4.2%. Results obtained in this study confirm the adequacy of the proposed methodology for assessing primary photon beams produced by clinical accelerators.

  1. SU-E-T-237: Monte Carlo Dosimetric Characterization of the Mobetron Mobile Linac

    SciTech Connect

    Garcia, F; Granero, D; Vijande, J; Ballester, F; Perez-Calatayud, J

    2014-06-01

    Purpose: The aim of this work is to characterize dosimetrically a clinical intraoperative electron beam accelerator, Mobetron (IntraOp Medical, Inc.) in clinical use in our Hospital. Once this first step is completed our purpose is to evaluate shielding requirements for such a device by preparing adequate phase space files. Methods: It is known that electron beam simulation parameters required for state-of-the-art Monte Carlo codes to obtain a good match with measured data, like the mean energy or the FWHM, may not be code-independent due to the different set of process simulated and formalisms involved. Then, to cross-check our results against any issue in the simulation we have compared experimental data (PDD and profiles for electrons in the range 4 to 12 MeV) with simulations performed independently using both Penelope2011 and Geant4 codes. To do so, the geometry and materials of the head of the accelerator have been fully characterized following information provided by the manufacturer. Results: Both simulations agree with experimental data within experimental uncertainties (±1 mm displacement), although small variations (less than 10%) in the mean energy and FWHM are required to match measured values depending on the code used. Conclusion: Independent Monte Carlo simulations were used to obtain an excellent match to measured electron dose distributions. This opens the road to use such data for evaluating shielding requirements which is the main objective of this project.

  2. Experimental benchmarking of a Monte Carlo dose simulation code for pediatric CT

    NASA Astrophysics Data System (ADS)

    Li, Xiang; Samei, Ehsan; Yoshizumi, Terry; Colsher, James G.; Jones, Robert P.; Frush, Donald P.

    2007-03-01

    In recent years, there has been a desire to reduce CT radiation dose to children because of their susceptibility and prolonged risk for cancer induction. Concerns arise, however, as to the impact of dose reduction on image quality and thus potentially on diagnostic accuracy. To study the dose and image quality relationship, we are developing a simulation code to calculate organ dose in pediatric CT patients. To benchmark this code, a cylindrical phantom was built to represent a pediatric torso, which allows measurements of dose distributions from its center to its periphery. Dose distributions for axial CT scans were measured on a 64-slice multidetector CT (MDCT) scanner (GE Healthcare, Chalfont St. Giles, UK). The same measurements were simulated using a Monte Carlo code (PENELOPE, Universitat de Barcelona) with the applicable CT geometry including bowtie filter. The deviations between simulated and measured dose values were generally within 5%. To our knowledge, this work is one of the first attempts to compare measured radial dose distributions on a cylindrical phantom with Monte Carlo simulated results. It provides a simple and effective method for benchmarking organ dose simulation codes and demonstrates the potential of Monte Carlo simulation for investigating the relationship between dose and image quality for pediatric CT patients.

  3. ["Interpreter of dreams" and "dreamer" in Homer].

    PubMed

    Brillante, Carlo

    2009-01-01

    In this essay I examine the figure of the homeric [Greek characters: see text], a term which recurs in two passages of the Iliad (I 63; V 149). It has been explained both with the meaning of "interpreter of dreams" and of "dreamer" using his own gifts in favour of the community. This latter seems to be the most ancient use of the word, as it results in the episode told in the first book of the Iliad (crisis in the Greek army after the plague sent by Apollo). This use has an interesting parallel in some functions of the Spartan ephors and, in the second millennium, in the professional figure of the "dreamer" in the nearby Hittite area. More doubtful is the meaning in the Iliad V 149, since, in this case, there are no sufficient reasons to give the commonly attributed meaning of "interpreter of dreams". The analysis of the word, which is undoubtedly linked to the epic tradition, also offers the occasion to linger on some important homeric dreams (Agamemnon, Penelope) and on the use of the same word in the Stories by Herodotus.

  4. Conception and realization of a parallel-plate free-air ionization chamber for the absolute dosimetry of an ultrasoft X-ray beam

    NASA Astrophysics Data System (ADS)

    Groetz, J.-E.; Ounoughi, N.; Mavon, C.; Belafrites, A.; Fromm, M.

    2014-08-01

    We report the design of a millimeter-sized parallel plate free-air ionization chamber (IC) aimed at determining the absolute air kerma rate of an ultra-soft X-ray beam (E = 1.5 keV). The size of the IC was determined so that the measurement volume satisfies the condition of charged-particle equilibrium. The correction factors necessary to properly measure the absolute kerma using the IC have been established. Particular attention was given to the determination of the effective mean energy for the 1.5 keV photons using the PENELOPE code. Other correction factors were determined by means of computer simulation (COMSOL™and FLUKA). Measurements of air kerma rates under specific operating parameters of the lab-bench X-ray source have been performed at various distances from that source and compared to Monte Carlo calculations. We show that the developed ionization chamber makes it possible to determine accurate photon fluence rates in routine work and will constitute substantial time-savings for future radiobiological experiments based on the use of ultra-soft X-rays.

  5. Structural and Population Polymorphism of RT-Like Sequences in Avian Schistosomes Trichobilharzia szidati (Platyhelminthes: Digenea: Schistosomatidae)

    PubMed Central

    Semyenova, S. K.; Chrisanfova, G. G.; Guliaev, A. S.; Yesakova, A. P.; Ryskov, A. P.

    2015-01-01

    Recently we developed the genus-specific markers of the avian schistosomes of the genus Trichobilharzia, the causative agents of human cercarial dermatitis. The 7 novel genome sequences of T. franki, T. regenti, and T. szidati revealed similarity with genome repeat region of African schistosome Schistosoma mansoni. In the present work we analyzed the 37 new T. szidati sequences to study intragenome variability and host specificity for the parasite from three localities of East Europe. DNAs were isolated from cercariae or single sporocysts obtained from 6 lymnaeid snails Lymnaea stagnalis and L. palustris from Belarus and Russia. All sequences formed three diverged groups, one of which consists of the sequences with multiple deletions; other groups involved two paralogous copies with stop codons and frameshift mutations. Strong association between geographical distribution and snail host specificity cannot be established. All studied sequences have homology with the reverse transcriptase domain (RT) of Penelope-like elements (PLE) of S. mansoni and S. japonicum and new members of RT family were identified. We proposed that three diverged groups RT sequences of T. szidati are results of duplication or transposition of PLE during parasite evolution. Implications of the retroelement dynamics in the life history of avian schistosomes are discussed. PMID:26114104

  6. CloudMC: a cloud computing application for Monte Carlo simulation.

    PubMed

    Miras, H; Jiménez, R; Miras, C; Gomà, C

    2013-04-21

    This work presents CloudMC, a cloud computing application-developed in Windows Azure®, the platform of the Microsoft® cloud-for the parallelization of Monte Carlo simulations in a dynamic virtual cluster. CloudMC is a web application designed to be independent of the Monte Carlo code in which the simulations are based-the simulations just need to be of the form: input files → executable → output files. To study the performance of CloudMC in Windows Azure®, Monte Carlo simulations with penelope were performed on different instance (virtual machine) sizes, and for different number of instances. The instance size was found to have no effect on the simulation runtime. It was also found that the decrease in time with the number of instances followed Amdahl's law, with a slight deviation due to the increase in the fraction of non-parallelizable time with increasing number of instances. A simulation that would have required 30 h of CPU on a single instance was completed in 48.6 min when executed on 64 instances in parallel (speedup of 37 ×). Furthermore, the use of cloud computing for parallel computing offers some advantages over conventional clusters: high accessibility, scalability and pay per usage. Therefore, it is strongly believed that cloud computing will play an important role in making Monte Carlo dose calculation a reality in future clinical practice.

  7. Rapid and recent diversification of curassows, guans, and chachalacas (Galliformes: Cracidae) out of Mesoamerica: Phylogeny inferred from mitochondrial, intron, and ultraconserved element sequences.

    PubMed

    Hosner, Peter A; Braun, Edward L; Kimball, Rebecca T

    2016-09-01

    The Cracidae (curassows, guans, and chachalacas) include some of the most spectacular and endangered Neotropical bird species. They lack a comprehensive phylogenetic hypothesis, hence their geographic origin and the history of their diversification remain unclear. We present a species-level phylogeny of Cracidae inferred from a matrix of 430 ultraconserved elements (UCEs; at least one species sampled per genus) and eight more variable loci (introns and mtDNA; all available species). We use this phylogeny along with probabilistic biogeographic modeling to test whether Gondwanan vicariance, ancient dispersal to South America, ancient dispersal from South America, or massive global cooling isolated cracids in the Neotropics. Contrary to previous estimates that extant cracids diversified in the Cretaceous, our fossil-calibrated divergence time estimates instead support that crown Cracidae originated in the late Miocene. Species-rich genera Crax, Penelope, and Ortalis began diversifying as recently as 3Mya. Biogeographic reconstructions indicate that modern cracids originated in Mesoamerica and were isolated from a widespread Laurasian ancestor, consistent with the massive global cooling hypothesis. Current South American diversity is the result of multiple colonization events following uplift of the Panamanian Isthmus, coupled with rapid diversification and evolution of secondary sympatry. Of the four major cracid lineages (curassows, chachalacas, typical guans, horned guan), the only lineage that has failed to colonize and diversify South America is the unique horned guan (Oreophasis derbianus), which is sister to curassows and chachalacas rather than typical guans.

  8. Experimental Evidence Shows the Importance of Behavioural Plasticity and Body Size under Competition in Waterfowl

    PubMed Central

    Zhang, Yong; Prins, Herbert H. T.; Versluijs, Martijn; Wessels, Rick; Cao, Lei; de Boer, Willem Frederik

    2016-01-01

    When differently sized species feed on the same resources, interference competition may occur, which may negatively affect their food intake rate. It is expected that competition between species also alters behaviour and feeding patch selection. To assess these changes in behaviour and patch selection, we applied an experimental approach using captive birds of three differently sized Anatidae species: wigeon (Anas penelope) (~600 g), swan goose (Anser cygnoides) (~2700 g) and bean goose (Anser fabalis) (~3200 g). We quantified the functional response for each species and then recorded their behaviour and patch selection with and without potential competitors, using different species combinations. Our results showed that all three species acquired the highest nitrogen intake at relatively tall swards (6, 9 cm) when foraging in single species flocks in the functional response experiment. Goose species were offered foraging patches differing in sward height with and without competitors, and we tested for the effect of competition on foraging behaviour. The mean percentage of time spent feeding and being vigilant did not change under competition for all species. However, all species utilized strategies that increased their peck rate on patches across different sward heights, resulting in the same instantaneous and nitrogen intake rate. Our results suggest that variation in peck rate over different swards height permits Anatidae herbivores to compensate for the loss of intake under competition, illustrating the importance of behavioural plasticity in heterogeneous environments when competing with other species for resources. PMID:27727315

  9. Conception and realization of a parallel-plate free-air ionization chamber for the absolute dosimetry of an ultrasoft X-ray beam

    SciTech Connect

    Groetz, J.-E. Mavon, C.; Fromm, M.; Ounoughi, N.; Belafrites, A.

    2014-08-15

    We report the design of a millimeter-sized parallel plate free-air ionization chamber (IC) aimed at determining the absolute air kerma rate of an ultra-soft X-ray beam (E = 1.5 keV). The size of the IC was determined so that the measurement volume satisfies the condition of charged-particle equilibrium. The correction factors necessary to properly measure the absolute kerma using the IC have been established. Particular attention was given to the determination of the effective mean energy for the 1.5 keV photons using the PENELOPE code. Other correction factors were determined by means of computer simulation (COMSOL™and FLUKA). Measurements of air kerma rates under specific operating parameters of the lab-bench X-ray source have been performed at various distances from that source and compared to Monte Carlo calculations. We show that the developed ionization chamber makes it possible to determine accurate photon fluence rates in routine work and will constitute substantial time-savings for future radiobiological experiments based on the use of ultra-soft X-rays.

  10. Implementation of new physics models for low energy electrons in liquid water in Geant4-DNA.

    PubMed

    Bordage, M C; Bordes, J; Edel, S; Terrissol, M; Franceries, X; Bardiès, M; Lampe, N; Incerti, S

    2016-12-01

    A new alternative set of elastic and inelastic cross sections has been added to the very low energy extension of the Geant4 Monte Carlo simulation toolkit, Geant4-DNA, for the simulation of electron interactions in liquid water. These cross sections have been obtained from the CPA100 Monte Carlo track structure code, which has been a reference in the microdosimetry community for many years. They are compared to the default Geant4-DNA cross sections and show better agreement with published data. In order to verify the correct implementation of the CPA100 cross section models in Geant4-DNA, simulations of the number of interactions and ranges were performed using Geant4-DNA with this new set of models, and the results were compared with corresponding results from the original CPA100 code. Good agreement is observed between the implementations, with relative differences lower than 1% regardless of the incident electron energy. Useful quantities related to the deposited energy at the scale of the cell or the organ of interest for internal dosimetry, like dose point kernels, are also calculated using these new physics models. They are compared with results obtained using the well-known Penelope Monte Carlo code.

  11. Biological equivalent dose studies for dose escalation in the stereotactic synchrotron radiation therapy clinical trials

    SciTech Connect

    Prezado, Y.; Fois, G.; Edouard, M.; Nemoz, C.; Renier, M.; Requardt, H.; Esteve, F.; Adam, JF.; Elleaume, H.; Bravin, A.

    2009-03-15

    Synchrotron radiation is an innovative tool for the treatment of brain tumors. In the stereotactic synchrotron radiation therapy (SSRT) technique a radiation dose enhancement specific to the tumor is obtained. The tumor is loaded with a high atomic number (Z) element and it is irradiated in stereotactic conditions from several entrance angles. The aim of this work was to assess dosimetric properties of the SSRT for preparing clinical trials at the European Synchrotron Radiation Facility (ESRF). To estimate the possible risks, the doses received by the tumor and healthy tissues in the future clinical conditions have been calculated by using Monte Carlo simulations (PENELOPE code). The dose enhancement factors have been determined for different iodine concentrations in the tumor, several tumor positions, tumor sizes, and different beam sizes. A scheme for the dose escalation in the various phases of the clinical trials has been proposed. The biological equivalent doses and the normalized total doses received by the skull have been calculated in order to assure that the tolerance values are not reached.

  12. "How to stop choking to death": Rethinking lesbian separatism as a vibrant political theory and feminist practice.

    PubMed

    Enszer, Julie R

    2016-01-01

    In contemporary feminist discourses, lesbian separatism is often mocked. Whether blamed as a central reason for feminism's alleged failure or seen as an unrealistic, utopian vision, lesbian separatism is a maligned social and cultural formation. This article traces the intellectual roots of lesbian feminism from the early 1970s in The Furies and Radicalesbians through the work of Julia Penelope and Sarah Lucia Hoagland in the 1980s and 1990s, then considers four feminist and lesbian organizations that offer innovative engagements with lesbian separatism. Olivia Records operated as a separatist enterprise, producing and distributing womyn's music during the 1970s and 1980s. Two book distributors, Women in Distribution, which operated in the 1970s, and Diaspora Distribution, which operated in the 1980s, offer another approach to lesbian separatism as a form of economic and entrepreneurial engagement. Finally, Sinister Wisdom, a lesbian-feminist literary and arts journal, enacts a number of different forms of lesbian separatism during its forty-year history. These four examples demonstrate economic and cultural investments of lesbian separatism and situate its investments in larger visionary feminist projects. More than a rigid ideology, lesbian separatism operates as a feminist process, a method for living in the world.

  13. Monte Carlo dosimetric study of the medium dose rate CSM40 source.

    PubMed

    Vijande, J; Granero, D; Perez-Calatayud, J; Ballester, F

    2013-12-01

    The (137)Cs medium dose rate (MDR) CSM40 source model (Eckert & Ziegler BEBIG, Germany) is in clinical use but no dosimetric dataset has been published. This study aims to obtain dosimetric data for the CSM40 source for its use in clinical practice as required by the American Association of Physicists in Medicine (AAPM) and the European Society for Radiotherapy and Oncology (ESTRO). Penelope2008 and Geant4 Monte Carlo codes were used to characterize this source dosimetrically. It was located in an unbounded water phantom with composition and mass density as recommended by AAPM and ESTRO. Due to the low photon energies of (137)Cs, absorbed dose was approximated by collisional kerma. Additional simulations were performed to obtain the air-kerma strength, sK. Mass-energy absorption coefficients in water and air were consistently derived and used to calculate collisional kerma. Results performed with both radiation transport codes showed agreement typically within 0.05%. Dose rate constant, radial dose function and anisotropy function are provided for the CSM40 and compared with published data for other commercially available (137)Cs sources. An uncertainty analysis has been performed. The data provided by this study can be used as input data and verification in the treatment planning systems.

  14. Angular distribution of thick-target bremsstrahlung produced by electrons with initial energies ranging from 10 to 20 keV incident on Ag

    SciTech Connect

    Gonzales, D.; Cavness, B.; Williams, S.

    2011-11-15

    Experimental results are presented comparing the intensities of the bremsstrahlung produced by electrons with initial energies ranging from 10 to 20 keV incident on a thick Ag target, measured at forward angles in the range of 0 degree sign to 55 degree sign . When the data are corrected for attenuation due to photon absorption within the target, the results indicate that the detected radiation is distributed anisotropically only at photon energies k that are approximately equal to the initial energy of the incident electrons E{sub 0}. The results of our experiments suggest that, as k/E{sub 0}{yields} 0, the detected radiation essentially becomes isotropic due primarily to the scattering of electrons within the target. A comparison to the theory of Kissel et al.[At. Data Nucl. Data Tables 28, 381 (1983)] suggests that the angular distribution of bremsstrahlung emitted by electrons incident on thick targets is similar to the angular distribution of bremsstrahlung emitted by electrons incident on free-atom targets only when k/E{sub 0}{approx_equal} 1. The experimental data also are in approximate agreement with the angular distribution predictions of the Monte Carlo program penelope.

  15. Monte-Carlo simulation of a slot-scanning X-ray imaging system.

    PubMed

    Kulkarni, Mayuresh; Dendere, Ronald; Nicolls, Fred; Steiner, Stef; Douglas, Tania S

    2016-01-01

    We present a method for simulating slot-scanning X-ray imaging using the general-purpose Monte Carlo simulation package PENELOPE and penEasy Imaging. Different phantoms can be defined with the PENGEOM package, which defines bodies as combinations of volumes limited by quadric surfaces. The source-detector geometry, the position of the object, the collimator, the X-ray tube properties, the detector material and the pixel dimensions are defined. The output of the time-delay integration detector is simulated using sequential slot outputs derived from penEasy Imaging. The simulations are validated using tungsten and aluminium test objects, which are both simulated and imaged. The simulations are compared to the X-ray images using standard image quality metrics. The MTF, NPS and DQE curves show that the real and simulated X-ray images are comparable in terms of spatial resolution, noise and frequency information. The implementation can be modified to suit alterations in the system being simulated.

  16. Monte Carlo calculated microdosimetric spread for cell nucleus-sized targets exposed to brachytherapy 125I and 192Ir sources and 60Co cell irradiation.

    PubMed

    Villegas, Fernanda; Tilly, Nina; Ahnesjö, Anders

    2013-09-07

    The stochastic nature of ionizing radiation interactions causes a microdosimetric spread in energy depositions for cell or cell nucleus-sized volumes. The magnitude of the spread may be a confounding factor in dose response analysis. The aim of this work is to give values for the microdosimetric spread for a range of doses imparted by (125)I and (192)Ir brachytherapy radionuclides, and for a (60)Co source. An upgraded version of the Monte Carlo code PENELOPE was used to obtain frequency distributions of specific energy for each of these radiation qualities and for four different cell nucleus-sized volumes. The results demonstrate that the magnitude of the microdosimetric spread increases when the target size decreases or when the energy of the radiation quality is reduced. Frequency distributions calculated according to the formalism of Kellerer and Chmelevsky using full convolution of the Monte Carlo calculated single track frequency distributions confirm that at doses exceeding 0.08 Gy for (125)I, 0.1 Gy for (192)Ir, and 0.2 Gy for (60)Co, the resulting distribution can be accurately approximated with a normal distribution. A parameterization of the width of the distribution as a function of dose and target volume of interest is presented as a convenient form for the use in response modelling or similar contexts.

  17. Diaphragm correction factors for free-air chamber standards for air kerma in x-rays.

    PubMed

    Burns, D T; Kessler, C

    2009-05-07

    At present, only a correction factor for photon transmission, k(l), is systematically applied for the entrance diaphragm of free-air chamber standards for air kerma. In the present work, the Monte Carlo code PENELOPE is used to re-evaluate k(l) for the BIPM standards and new correction factors are calculated for photon scatter and for fluorescence production in the diaphragm. An additional effect arising from electrons emitted from the diaphragm is shown to be significant at the highest photon energies. The results for the radiation qualities used for international comparisons give a combined diaphragm correction factor k(dia) = 0.9980(3) for the BIPM medium-energy standard at 250 kV. This is significantly different from the factor k(l) = 0.9996(1) in use at present and it might be concluded that differences are likely to exist for all free-air chamber standards. The effect of using a conical taper at the downstream edge of the diaphragm is shown to be negligible for these radiation qualities.

  18. A Monte Carlo (MC) based individual calibration method for in vivo x-ray fluorescence analysis (XRF).

    PubMed

    Hansson, Marie; Isaksson, Mats

    2007-04-07

    X-ray fluorescence analysis (XRF) is a non-invasive method that can be used for in vivo determination of thyroid iodine content. System calibrations with phantoms resembling the neck may give misleading results in the cases when the measurement situation largely differs from the calibration situation. In such cases, Monte Carlo (MC) simulations offer a possibility of improving the calibration by better accounting for individual features of the measured subjects. This study investigates the prospects of implementing MC simulations in a calibration procedure applicable to in vivo XRF measurements. Simulations were performed with Penelope 2005 to examine a procedure where a parameter, independent of the iodine concentration, was used to get an estimate of the expected detector signal if the thyroid had been measured outside the neck. An attempt to increase the simulation speed and reduce the variance by exclusion of electrons and by implementation of interaction forcing was conducted. Special attention was given to the geometry features: analysed volume, source-sample-detector distances, thyroid lobe size and position in the neck. Implementation of interaction forcing and exclusion of electrons had no obvious adverse effect on the quotients while the simulation time involved in an individual calibration was low enough to be clinically feasible.

  19. Efficient Simulation of Secondary Fluorescence Via NIST DTSA-II Monte Carlo.

    PubMed

    Ritchie, Nicholas W M

    2017-03-13

    Secondary fluorescence, the final term in the familiar matrix correction triumvirate Z·A·F, is the most challenging for Monte Carlo models to simulate. In fact, only two implementations of Monte Carlo models commonly used to simulate electron probe X-ray spectra can calculate secondary fluorescence-PENEPMA and NIST DTSA-II a (DTSA-II is discussed herein). These two models share many physical models but there are some important differences in the way each implements X-ray emission including secondary fluorescence. PENEPMA is based on PENELOPE, a general purpose software package for simulation of both relativistic and subrelativistic electron/positron interactions with matter. On the other hand, NIST DTSA-II was designed exclusively for simulation of X-ray spectra generated by subrelativistic electrons. NIST DTSA-II uses variance reduction techniques unsuited to general purpose code. These optimizations help NIST DTSA-II to be orders of magnitude more computationally efficient while retaining detector position sensitivity. Simulations execute in minutes rather than hours and can model differences that result from detector position. Both PENEPMA and NIST DTSA-II are capable of handling complex sample geometries and we will demonstrate that both are of similar accuracy when modeling experimental secondary fluorescence data from the literature.

  20. Lack of virological and serological evidence for continued circulation of highly pathogenic avian influenza H5N8 virus in wild birds in the Netherlands, 14 November 2014 to 31 January 2016

    PubMed Central

    Poen, Marjolein J; Verhagen, Josanne H; Manvell, Ruth J; Brown, Ian; Bestebroer, Theo M; van der Vliet, Stefan; Vuong, Oanh; Scheuer, Rachel D; van der Jeugd, Henk P; Nolet, Bart A; Kleyheeg, Erik; Müskens, Gerhard J D M; Majoor, Frank A; Grund, Christian; Fouchier, Ron A M

    2016-01-01

    In 2014, H5N8 clade 2.3.4.4 highly pathogenic avian influenza (HPAI) viruses of the A/Goose/Guangdong/1/1996 lineage emerged in poultry and wild birds in Asia, Europe and North America. Here, wild birds were extensively investigated in the Netherlands for HPAI H5N8 virus (real-time polymerase chain reaction targeting the matrix and H5 gene) and antibody detection (haemagglutination inhibition and virus neutralisation assays) before, during and after the first virus detection in Europe in late 2014. Between 21 February 2015 and 31 January 2016, 7,337 bird samples were tested for the virus. One HPAI H5N8 virus-infected Eurasian wigeon (Anas penelope) sampled on 25 February 2015 was detected. Serological assays were performed on 1,443 samples, including 149 collected between 2007 and 2013, 945 between 14 November 2014 and 13 May 2015, and 349 between 1 September and 31 December 2015. Antibodies specific for HPAI H5 clade 2.3.4.4 were absent in wild bird sera obtained before 2014 and present in sera collected during and after the HPAI H5N8 emergence in Europe, with antibody incidence declining after the 2014/15 winter. Our results indicate that the HPAI H5N8 virus has not continued to circulate extensively in wild bird populations since the 2014/15 winter and that independent maintenance of the virus in these populations appears unlikely. PMID:27684783

  1. On the Monte Carlo simulation of small-field micro-diamond detectors for megavoltage photon dosimetry

    NASA Astrophysics Data System (ADS)

    Andreo, Pedro; Palmans, Hugo; Marteinsdóttir, Maria; Benmakhlouf, Hamza; Carlsson-Tedgren, Åsa

    2016-01-01

    Monte Carlo (MC) calculated detector-specific output correction factors for small photon beam dosimetry are commonly used in clinical practice. The technique, with a geometry description based on manufacturer blueprints, offers certain advantages over experimentally determined values but is not free of weaknesses. Independent MC calculations of output correction factors for a PTW-60019 micro-diamond detector were made using the EGSnrc and PENELOPE systems. Compared with published experimental data the MC results showed substantial disagreement for the smallest field size simulated (5~\\text{mm}× 5 mm). To explain the difference between the two datasets, a detector was imaged with x rays searching for possible anomalies in the detector construction or details not included in the blueprints. A discrepancy between the dimension stated in the blueprints for the active detector area and that estimated from the electrical contact seen in the x-ray image was observed. Calculations were repeated using the estimate of a smaller volume, leading to results in excellent agreement with the experimental data. MC users should become aware of the potential differences between the design blueprints of a detector and its manufacturer production, as they may differ substantially. The constraint is applicable to the simulation of any detector type. Comparison with experimental data should be used to reveal geometrical inconsistencies and details not included in technical drawings, in addition to the well-known QA procedure of detector x-ray imaging.

  2. Formalizing structured file services for the data storage and retrieval subsystem of the data management system for Spacestation Freedom

    NASA Technical Reports Server (NTRS)

    Jamsek, Damir A.

    1993-01-01

    A brief example of the use of formal methods techniques in the specification of a software system is presented. The report is part of a larger effort targeted at defining a formal methods pilot project for NASA. One possible application domain that may be used to demonstrate the effective use of formal methods techniques within the NASA environment is presented. It is not intended to provide a tutorial on either formal methods techniques or the application being addressed. It should, however, provide an indication that the application being considered is suitable for a formal methods by showing how such a task may be started. The particular system being addressed is the Structured File Services (SFS), which is a part of the Data Storage and Retrieval Subsystem (DSAR), which in turn is part of the Data Management System (DMS) onboard Spacestation Freedom. This is a software system that is currently under development for NASA. An informal mathematical development is presented. Section 3 contains the same development using Penelope (23), an Ada specification and verification system. The complete text of the English version Software Requirements Specification (SRS) is reproduced in Appendix A.

  3. Simulation of decay processes and radiation transport times in radioactivity measurements

    NASA Astrophysics Data System (ADS)

    García-Toraño, E.; Peyres, V.; Bé, M.-M.; Dulieu, C.; Lépy, M.-C.; Salvat, F.

    2017-04-01

    The Fortran subroutine package PENNUC, which simulates random decay pathways of radioactive nuclides, is described. The decay scheme of the active nuclide is obtained from the NUCLEIDE database, whose web application has been complemented with the option of exporting nuclear decay data (possible nuclear transitions, branching ratios, type and energy of emitted particles) in a format that is readable by the simulation subroutines. In the case of beta emitters, the initial energy of the electron or positron is sampled from the theoretical Fermi spectrum. De-excitation of the atomic electron cloud following electron capture and internal conversion is described using transition probabilities from the LLNL Evaluated Atomic Data Library and empirical or calculated energies of released X rays and Auger electrons. The time evolution of radiation showers is determined by considering the lifetimes of nuclear and atomic levels, as well as radiation propagation times. Although PENNUC is designed to operate independently, here it is used in conjunction with the electron-photon transport code PENELOPE, and both together allow the simulation of experiments with radioactive sources in complex material structures consisting of homogeneous bodies limited by quadric surfaces. The reliability of these simulation tools is demonstrated through comparisons of simulated and measured energy spectra from radionuclides with complex multi-gamma spectra, nuclides with metastable levels in their decay pathways, nuclides with two daughters, and beta plus emitters.

  4. GEMS X-ray Polarimeter Performance Simulations

    NASA Technical Reports Server (NTRS)

    Baumgartner, Wayne H.; Strohmayer, Tod; Kallman, Tim; Black, J. Kevin; Hill, Joanne; Swank, Jean

    2012-01-01

    The Gravity and Extreme Magnetism Small explorer (GEMS) is an X-ray polarization telescope selected as a NASA small explorer satellite mission. The X-ray Polarimeter on GEMS uses a Time Projection Chamber gas proportional counter to measure the polarization of astrophysical X-rays in the 2-10 keV band by sensing the direction of the track of the primary photoelectron excited by the incident X-ray. We have simulated the expected sensitivity of the polarimeter to polarized X-rays. We use the simulation package Penelope to model the physics of the interaction of the initial photoelectron with the detector gas and to determine the distribution of charge deposited in the detector volume. We then model the charge diffusion in the detector,and produce simulated track images. Within the track reconstruction algorithm we apply cuts on the track shape and focus on the initial photoelectron direction in order to maximize the overall sensitivity of the instrument, using this technique we have predicted instrument modulation factors nu(sub 100) for 100% polarized X-rays ranging from 10% to over 60% across the 2-10 keV X-ray band. We also discuss the simulation program used to develop and model some of the algorithms used for triggering, and energy measurement of events in the polarimeter.

  5. PENGEOM-A general-purpose geometry package for Monte Carlo simulation of radiation transport in material systems defined by quadric surfaces

    NASA Astrophysics Data System (ADS)

    Almansa, Julio; Salvat-Pujol, Francesc; Díaz-Londoño, Gloria; Carnicer, Artur; Lallena, Antonio M.; Salvat, Francesc

    2016-02-01

    The Fortran subroutine package PENGEOM provides a complete set of tools to handle quadric geometries in Monte Carlo simulations of radiation transport. The material structure where radiation propagates is assumed to consist of homogeneous bodies limited by quadric surfaces. The PENGEOM subroutines (a subset of the PENELOPE code) track particles through the material structure, independently of the details of the physics models adopted to describe the interactions. Although these subroutines are designed for detailed simulations of photon and electron transport, where all individual interactions are simulated sequentially, they can also be used in mixed (class II) schemes for simulating the transport of high-energy charged particles, where the effect of soft interactions is described by the random-hinge method. The definition of the geometry and the details of the tracking algorithm are tailored to optimize simulation speed. The use of fuzzy quadric surfaces minimizes the impact of round-off errors. The provided software includes a Java graphical user interface for editing and debugging the geometry definition file and for visualizing the material structure. Images of the structure are generated by using the tracking subroutines and, hence, they describe the geometry actually passed to the simulation code.

  6. Contrast-enhanced radiotherapy: feasibility and characteristics of the physical absorbed dose distribution for deep-seated tumors

    NASA Astrophysics Data System (ADS)

    Garnica-Garza, H. M.

    2009-09-01

    Radiotherapy using kilovoltage x-rays in conjunction with contrast agents incorporated into the tumor, gold nanoparticles in particular, could represent a potential alternative to current techniques based on high-energy linear accelerators. In this paper, using the voxelized Zubal phantom in conjunction with the Monte Carlo code PENELOPE to model a prostate cancer treatment, it is shown that in combination with a 360° arc delivery technique, tumoricidal doses of radiation can be delivered to deep-seated tumors while still providing acceptable doses to the skin and other organs at risk for gold concentrations in the tumor within the range of 7-10 mg-Au per gram of tissue. Under these conditions and using a x-ray beam with 90% of the fluence within the range of 80-200 keV, a 72 Gy physical absorbed dose to the prostate can be delivered, while keeping the rectal wall, bladder, skin and femoral heads below 65 Gy, 55 Gy, 40 Gy and 30 Gy, respectively. However, it is also shown that non-uniformities in the contrast agent concentration lead to a severe degradation of the dose distribution and that, therefore, techniques to locally quantify the presence of the contrast agent would be necessary in order to determine the incident x-ray fluence that best reproduces the dosimetry obtained under conditions of uniform contrast agent distribution.

  7. Indirect comparison of lixisenatide versus neutral protamine Hagedorn insulin as add-on to metformin and sulphonylurea in patients with type 2 diabetes mellitus.

    PubMed

    Fournier, Marie; Germe, Maeva; Theobald, Karlheinz; Scholz, Gerhard H; Lehmacher, Walter

    2014-01-01

    Zielsetzung: Derzeit mangelt es an direkten Vergleichen von Behandlungsergebnissen zwischen Lixisenatid und NPH-Insulin bei Typ-2-Diabetikern (T2DM) mit suboptimaler Blutzuckerkontrolle unter einer oralen Kombinationstherapie aus Metformin und einem Sulfonylharnstoff. Deshalb untersucht der vorliegende adjustierte indirekte Vergleich die verfügbare Evidenz primär zum Hypoglykämierisiko sowie zur Gewichtsveränderung zwischen Lixisenatid und NPH-Insulin auf Basis randomisierter kontrollierter Studien mit den Brückenkomparatoren Exenatide, Insulin glargin und Plazebo. Methoden: Zwei systematische Literaturrecherchen in PubMed, Embase, der Cochrane-Datenbank sowie in klinischen Registern identifizierten englisch- und deutschsprachige Publikationen, die entsprechende Ergebnisdaten aus randomisierten klinischen Studien (RCTs) enthielten und die zwischen Januar 1980 und Oktober 2012 veröffentlicht worden waren. Bestimmt durch die GetGoal-S Studie (Lixisenatid) mit einer Analyse der primären Endpunkte nach 24 Wochen, wurden nur Publikationen eingeschlossen, die Ergebnisse aus 24–30-wöchigen Studien zum Vergleich von GLP-1 Rezeptoragonisten oder Basalinsulinen vs. andere Antidiabetika oder Plazebo umfassten. Für die binären Ergebnisvariablen Hypoglykämiehäufigkeit, Anteil der Patienten mit dem erreichten HbA1c-Zielwert sowie Studienabbrüche wegen unerwünschter Ereignisse wurden die relativen Risiken (RR) sowie die Odds Ratios (OR) als statistische Maße verwendet. Für die kontinuierlichen Ergebnisvariablen glykosyliertes Hämoglobin (HbA1c) und Körpergewicht wurden die Differenzen der mittleren Veränderungen zum Ausgangswert (MD) als statistisches Maß verwendet. Notwendige Metaanalysen wurden auf Basis von Modellen mit zufälligen Effekten durchgeführt, die indirekten Vergleiche nach der Methode von Bucher.Ergebnisse: Sieben RCTs (n=3.301 Patienten), die die Wirksamkeit und Sicherheit von Lixisenatid, Exenatide, Insulin glargin oder NPH-Insulin gegen

  8. Effects of a rater training on rating accuracy in a physical examination skills assessment.

    PubMed

    Weitz, Gunther; Vinzentius, Christian; Twesten, Christoph; Lehnert, Hendrik; Bonnemeier, Hendrik; König, Inke R

    2014-01-01

    Hintergrund: Die Genauigkeit und Reproduzierbarkeit von Prüferurteilen im Medizinstudium ist gering. Eine Schulung von Prüfern hat keinen oder allenfalls minimalen Effekt. Die dazu verfügbaren Studien beziehen sich jedoch auf die Beurteilung von Arzt-Patienten-Interaktionen in eigens dafür angefertigten Videos. Wir untersuchten, ob eine Schulung, die sich auf den Bezugsrahmen des Prüfers bezieht, die Prüfergenauigkeit bei curricularen Untersuchungskurstestaten verbessert.Methoden: 21 Prüfer testierten 242 Studierende im dritten Studienjahr. Elf der Prüfer wurden randomisiert ausgewählt, an einer kurzen Prüferschulung teilzunehmen, die wenige Tage vor dem Testat stattfand. 218 Testate konnten auf Video festgehalten werden und wurden später unabhängig von drei Nachprüfern bewertet. Genauigkeit definierten wir als die Konkordanz zwischen der Benotung des eigentlichen Prüfers und dem Median der Benotung der Nachprüfer. Im Anschluss an das Testat füllten sowohl Prüflinge als auch Prüfer einen Fragebogen zum Testat aus.Ergebnisse: Die Prüferschulung hatte keinen messbaren Einfluss auf die Genauigkeit der Bewertung. Die geschulten Prüfer waren aber strenger als die ungeschulten und ihr Notenspektrum lag eher in dem Bereich des Spektrums der Nachprüfer. Außerdem waren die geschulten Prüfer sich des Halo-Effektes stärker bewusst. Obwohl die Selbsteinschätzung der Studierenden in beiden Gruppen nahe bei der Prüfernote lag, waren die Studierenden, die von geschulten Prüfern testiert wurden, häufiger mit ihrer Note unzufrieden.Diskussion: Trotz einiger marginaler Effekte hatte die Prüferschulung keinen Effekt auf die Genauigkeit der Bewertung. Diese Beobachtung bei echten Testaten stimmt mit den Ergebnissen von Studien mit Videobewertungen überein. Auch die starke Standardisierung der Aufgabe im Testat half nicht, das Prüferurteil zu harmonisieren. Unsere Studie bestätigt, dass die Bewertung ärztlicher Tätigkeiten individuell sehr

  9. Wissenschaftliche Abhandlungen

    NASA Astrophysics Data System (ADS)

    Boltzmann, Ludwig; Hasenöhrl, Friedrich

    2012-08-01

    Vorwort; 1. Über die Bewegung der Elektrzität in krummen Flächen; 2. Über die mechanische Bedeutung des zweiten Hauptsatzes der Wärmetheorie; 3. Über die Anzahl der Atome; 4. Über die Integrale linearer Differentialgleighungen; 5. Studien über das Gleichgewicht der lebendingen Kraft; 6. Lösung eines mechanischen Problems; 7. Über die Festigkeit zweier mit Druck übereinander gesteckter zylindrischer Röhren; 8. Über die elektrodynamische Wechselwirkung der Reile eines elektrishen Stromes von veränderlicher Gestalt; 9. Bemerkung zur Abhandlung des Herrn R. Most; 10. Erwiderung an Herrn Most; 11. Über die von bewegten Gasmassen geleistete Arbeit; 12. Noch einiges über Kohlrauschs Versuch; 13. Über die Ableitung der Grundgleichungen der Kapillarität; 14. Über eine neue optische Methode; 15. Boiling points of organic bodies; 16. Über die Druckkräfte, welche auf Ringe wriksam sind; 17. Zur Priorität der Auffindung der Beziehung zwischen dem zweiten Hauptsatze der mechanischen Wärmetheorie; 18. Über das Wärmegleichgewicht zwischen mehratomigen Gasmolekülen; 19. Einige allgemeine Sätze über Wärmegleichgewicht; 20. Analytischer Beweis des zweiten Hauptsatzen der mechanischen Wärmetheorie; 21. Über das Wirkungsgesetz der Molekülarkräfte; 22. Weiteren Studien über das Wärmegleichgewicht unter Gasmolekülen; 23. Resultate einer Experimentaluntersuchung; 24. Experimentelle Bestimmung der Dielektrizitätskonstante von Isolatoren; 25. Experimentaluntersuchung über die elektrostatische Fernwirkung dielektrischer Körper; 26. Experimentelle Bestimmung der Dielektrizitätskonstante einiger Gase; 27. Über einige an meinen Versuchen; 28. Über die Verschiedenheit der Dielektrizitätskonstante des Körper unter dem Einflusse elektrische Kräfte; 29. Experimentaluntersuchung über das Verhalten nicht leitender Körper unter dem Einflusse electrischer Kräfte; 30. Zur Theorie der elastische Nachwirkung; 31. Über den Zusammenhang zwischen der Drehung

  10. (HFR-B1 experiment reporting and capsule disassembly)

    SciTech Connect

    Myers, B.F.

    1991-02-22

    The traveler visited the Joint Research Centre (JRC), Petten, The Netherlands, the Forschungszentrum GmbH (KFA), Juelich, Germany; and the Zentralinstitut fuer Kernforschung (ZfK), Rossendorf, Germany, during the period January 28 through February 9. At JRC, the analysis of the experiment HFR-B1 was discussed; a new schedule for issuance of the final data report was established. Other discussions at JRC concerned the capabilities of Petten to conduct two reactor experiments being proposed under the US/FRG cooperative program and the initial results of a proof test of Germany fuel spheres. At KFA, the main emphasis was on the disassembly of capsules 2 and 3 of the HFR-B1 experiment and agreement on the examinations and tests to be conducted with the disassembled components. The disassembly of capsule 3 was observed. Extensive discussions were conducted on the work, both experimental and analytical, being conducted in the Institut fuer Sicherheitsforschung und Reaktor Technologie. A major portion of the experimental work is being conducted at ZfK and a visit to this laboratory, sponosored by the KFA, was made on February 6 and 7. Cooperation with the US on the experimental and analytical work in the safety area was strongly emphasized. 1 tab.

  11. SUNRISE: a balloon-borne telescope for high resolution solar observations in the visible and UV

    NASA Astrophysics Data System (ADS)

    Solanki, Sami K.; Gandorfer, Achim M.; Schuessler, Manfred; Curdt, W.; Lites, Bruce W.; Martinez-Pillet, Valentin; Schmidt, Wolfgang; Title, Alan M.

    2003-02-01

    Sunrise is a light-weight solar telescope with a 1 m aperture for spectro-polarimetric observations of the solar atmosphere. The telescope is planned to be operated during a series of long-duration balloon flights in order to obtain time series of spectra and images at the diffraction-limit and to study the UV spectral region down to ~200 nm, which is not accessible from the ground. The central aim of Sunrise is to understand the structure and dynamics of the magnetic field in the solar atmosphere. Through its interaction with the convective flow field, the magnetic field in the solar photosphere develops intense field concentrations on scales below 100 km, which are crucial for the dynamics and energetics of the whole solar atmosphere. In addition, Sunrise aims to provide information on the structure and dynamics of the solar chromosphere and on the physics of solar irradiance changes. Sunrise is a joint project of the Max-Planck-Institut fuer Aeronomie (MPAe), Katlenburg-Lindau, with the Kiepenheuer-Institut fuer Sonnenphysik (KIS), Freiburg, the High-Altitude Observatory (HAO), Boulder, the Lockheed-Martin Solar and Astrophysics Lab. (LMSAL), Palo Alto, and the Instituto de Astrofi sica de Canarias, La Laguna, Tenerife. In addition, there are close contacts with associated scientists from a variety of institutes.

  12. Measurement of Quantum Phase-Slips in Josephson Junction Chains

    NASA Astrophysics Data System (ADS)

    Guichard, Wiebke

    2011-03-01

    Quantum phase-slip dynamics in Josephson junction chains could provide the basis for the realization of a new type of topologically protected qubit or for the implementation of a new current standard. I will present measurements of the effect of quantum phase-slips on the ground state of a Josephson junction chain. We can tune in situ the strength of the phase-slips. These phase-slips are the result of fluctuations induced by the finite charging energy of each junction in the chain. Our measurements demonstrate that a Josephson junction chain under phase bias constraint behaves in a collective way. I will also show evidence of coherent phase-slip interference, the so called Aharonov-Casher effect. This phenomenon is the dual of the well known Aharonov-Bohm interference. In collaboration with I.M. Pop, Institut Neel, C.N.R.S. and Universite Joseph Fourier, BP 166, 38042 Grenoble, France; I. Protopopov, L. D. Landau Institute for Theoretical Physics, Kosygin str. 2, Moscow 119334, Russia and Institut fuer Nanotechnologie, Karlsruher Institut fuer Technologie, 76021 Karlsruhe, Germany; and F. Lecocq, Z. Peng, B. Pannetier, O. Buisson, Institut Neel, C.N.R.S. and Universite Joseph Fourier. European STREP MIDAS, ANR QUANTJO.

  13. Handbook of environmental chemistry. Volume 4. Part A, air pollution

    SciTech Connect

    Hutzinger, O.

    1986-01-01

    Five authors have each contributed one chapter to this first part (A) of the series on Air Pollution (Volume 4). Thus the book is neither a handbook compilation of reference data nor a text on the subject of air pollution. The first and shortest chapter (22 pages) by A. Wint of the University of Nottingham, England, is an overview called Air Pollution in Perspective. The second chapter, by P. Fabian of Max-Planck-Institute fuer Aeronomie, FRG, is titled Halogenated Hydrocarbons in the Atmosphere. This chapter, in 29 pages, summarizes current data on twenty of these compounds. Hans Guesten of the Institute fuer Radiochemie, Karlsruhe, FRG, contributed chapter 3 on Formation, Transport, and Control of Photochemical Smog (52 pages). This chapter is a good survey of current understanding of smog although each of the three topics promised in the title could by itself take up a good sized book. Atmospheric Distribution of Pollutants and Modeling of Air Pollution Dispersion by H. van Dop of the Royal Netherlands Meteorological Institute, the Netherlands, makes up Chapter 4 (42 pages). The article is written from a meteorological perspective. The last chapter, by J.M. Hales of Battelle Pacific Northwest Laboratories, USA, is titled The Mathematical Characterization of Precipitation Scavenging and Precipitation Chemistry (74 pages). Removal of pollutants from the atmosphere by precipitation is good news/bad news.

  14. Key issues of the common French-German safety approach for future PWRs

    SciTech Connect

    Frisch, W.; Rohde, J.; Gros, G.; Queniart, D.

    1996-07-01

    The development of the common French-German safety approach started in 1992 after a preparatory phase of about 2 years. It was accomplished on three working levels: the technical safety organizations GRS (Gesellschaft fuer Anlagen- und Reaktorsicherheit) and IPSN (institute de Protection et de Surete Nucleaire) developed the technical basis, advisory groups GPR (Groupe Permanent charge des Reacteurs Nucleaires) and RSK (Reaktorsicherheitskommission) developed common recommendations, and the authorities BMU (Bundesministerium fuer Naturschutz, Umwelt und Reaktorsicherheit) and DSIN (Direction de la Surete des Installations Nucleaires) issued the common safety approach. The general common safety approach issued in May 1993 contains safety objectives, general principles and already some technical principles. Important objectives are to reduce the annual probability of core melt, to exclude large early releases and to mitigate low pressure core melt sequences so that the associated maximum conceivable release would necessitate only very limited protective measures in area and in time. Based on this general safety approach, more detailed recommendations have been developed in 1994. A selection of the detailed recommendations is presented in the full paper. These recommendations are applicable to the EPR project for which the basic design is now underway.

  15. Reconstructive surgery for male stress urinary incontinence: Experiences using the ATOMS(®) system at a single center.

    PubMed

    Krause, Jens; Tietze, Stefan; Behrendt, Wolf; Nast, Jenifer; Hamza, Amir

    2014-01-01

    Fragestellung: Es erfolgt die Darstellung der Probleme und Komplikationsraten mit dem ATOMS(®)-Schlingensystem an Hand von eigenen Ergebnissen, um aktuelle Behandlungsmöglichkeiten von männlicher Stressinkontinenz zu analysieren. Material und Methode: In dem definiertem Zeitraum (4/2010 bis 4/2014) wurde bei 36 Patienten ein ATOMS(®)-System in unserer Klinik implantiert. Die Evaluation erfolgte prä- und postoperativ mithilfe des internationalen Fragebogens zur Inkontinenz (ICIQ SF). Es erfolgte die Erweiterung des Fragebogen mit Fragen über die postoperative perineale Schmerzsymptomatik, die generelle Zufriedenheit mit Operationsergebnis und über die Bereitschaft zur Therapieweiterempfehlung an den besten Freund.Ergebnisse: Unsere Daten zeigen eine relativ hohe Explantationsrate, jedoch eine hohe Patientenzufriedenheit. Die Explantation war in den meisten Fällen aufgrund einer Spätinfektion des Implantats oder aufgrund anderer symptomatische Faktoren notwendig. Im Vergleich zu anderen Studien zeigte sich unmittelbar postoperativ eine geringere Infektionsrate. Schlussfolgerung: Ein nicht invasives, unkompliziertes adjustierbares System zur Linderung der männlichen Stressinkontinenz bleibt eine Herausforderung. Obwohl unterschiedliche Systeme zur Behandlung der männlichen Stressinkontinenz verfügbar sind, scheint es, dass ein artifizieller Sphincter mehr Vorteile gegenüber dem ATOMS(®)-Systems besitzt. Dies könnte jedoch auch aufgrund zahlreicher, gut dokumentierter und langfristiger Daten über den artifiziellen Sphincter begründet werden.

  16. Deciding what to see: the role of intention and attention in the perception of apparent motion.

    PubMed

    Kohler, Axel; Haddad, Leila; Singer, Wolf; Muckli, Lars

    2008-03-01

    Apparent motion is an illusory perception of movement that can be induced by alternating presentations of static objects. Already in Wertheimer's early investigation of the phenomenon [Wertheimer, M. (1912). Experimentelle Studien über das Sehen von Bewegung. Zeitschrift fur Psychologie, 61, 161-265], he mentions that voluntary attention can influence the way in which an ambiguous apparent motion display is perceived. But until now, few studies have investigated how strong the modulation of apparent motion through attention can be under different stimulus and task conditions. We used bistable motion quartets of two different sizes, where the perception of vertical and horizontal motion is equally likely. Eleven observers participated in two experiments. In Experiment 1, participants were instructed to either (a) hold the current movement direction as long as possible, (b) passively view the stimulus, or (c) switch the movement directions as quickly as possible. With the respective instructions, observers could almost double phase durations in (a) and more than halve durations in (c) relative to the passive condition. This modulation effect was stronger for the large quartets. In Experiment 2, observers' attention was diverted from the stimulus by a detection task at fixation while they still had to report their conscious perception. This manipulation prolonged dominance durations for up to 100%. The experiments reveal a high susceptibility of ambiguous apparent motion to attentional modulation. We discuss how feature- and space-based attention mechanisms might contribute to those effects.

  17. [Agreement between self-report and clinician's assessment in depressed adolescents, using the example of BDI-II and CDRS-R].

    PubMed

    Straub, Joana; Plener, Paul L; Koelch, Michael; Keller, Ferdinand

    2014-07-01

    Fragestellung: Vorhergehende Studien zeigen eine hohe Übereinstimmung von Selbst- und Klinikerurteil bei der Erfassung von Depressivität. Die Übereinstimmung auf Summen-, Subskalen- und Einzelitemebene wurde aber bisher nicht bei einer psychiatrischen jugendlichen Stichprobe untersucht. Der Einfluss von Drittvariablen, wie Alter, Geschlecht, IQ und Behandlungssetting wurde bei Jugendlichen bisher unzureichend überprüft. Methodik: Untersucht wurden 105 depressive Jugendliche (mittleres Alter = 15.94) bei welchen innerhalb einer Woche das BDI-II und CDRS-R durchgeführt wurde. Korrelationsanalysen erfolgten auf Ebene der Summenwerte, Subskalen und Einzelitems. Ergebnisse: Es zeigte sich eine hohe Korrelation zwischen Selbst- und Klinikerurteil (r = .67). Auf Subskalen-Ebene zeigten Items, die somatische Inhalte erfassen, keine höhere Konkordanz als Subskalen, die kognitive oder affektive Inhalte messen. Auf Symptom-Ebene zeigte sich die höchste Übereinstimmung bei dem Item Selbstmordgedanken. Drittvariablen hatten keinen signifikanten Einfluss auf die Höhe der Korrelation aber Jugendliche mit einem eher hohen IQ und ambulant Behandelte neigten zur relativen Überschätzung ihrer Symptomatik. Schlussfolgerungen: Die Gesamtkorrelation war hoch und unterschied sich nicht von Ergebnissen vergleichbarer Korrelationsstudien. Die höchste Übereinstimmung bei dem Item «Selbstmordgedanken» spricht für die gute Erfassbarkeit von Suizidalität auch im Klinikerurteil. Der Fragebogen kann somit deutliche Hinweise auf das Vorliegen einer Depression liefern, jedoch sollte trotz hoher Korrelationen nicht ein Verfahren durch ein anderes ersetzt werden.

  18. Berlin in Motion: Interprofessional teaching and learning for students in the fields of medicine, occupational therapy, physiotherapy and nursing (INTER-M-E-P-P).

    PubMed

    Bohrer, Annerose; Heinze, Cornelia; Höppner, Heidi; Behrend, Ronja; Czakert, Judith; Hitzblech, Tanja; Kaufmann, Ina; Maaz, Asja; Räbiger, Jutta; Peters, Harm

    2016-01-01

    Zielsetzung: Das Berliner Projekt „Interprofessionelles Lehren und Lernen in Medizin, Ergotherapie, Physiotherapie und Pflege“ (INTER-M-E-P-P) verfolgt das Ziel, interprofessionelle Lehrveranstaltungen modellhaft zu entwickeln, zu erproben und in die Curricula der Studiengänge zu implementieren. Methodik: Unter der Leitung einer institutions-, professions- und statusübergreifenden Lenkungsgruppe werden interprofessionelle Lehrveranstaltungen konzipiert, durchgeführt und evaluiert. Spezifisch sind die studentische Partizipation in der Lenkungsgruppe und die Begleitung durch externe Supervision. Die Evaluation integriert die Perspektiven aller am Projekt Beteiligten und kombiniert qualitative und quantitative Methoden. Ergebnisse: INTER-M-E-P-P hat Strukturen zur Kooperation der beteiligten Hochschulen und Studiengänge aufgebaut. Drei Lehrveranstaltungen wurden interprofessionell konzipiert, durchgeführt und evaluiert. Die unterschiedliche curriculare, strukturelle und räumliche Verortung der Studiengänge führt zu einem hohen, ressourcenintensiven Planungs- und Umsetzungsaufwand. Stereotype und Rollenbilder der Planenden können den Prozess erschweren; unter externer Supervision jedoch die professionsspezifischen Blickwinkel erweitern und bereichern.Schlussfolgerung: Eine nachhaltige Implementierung von IPL in die Curricula der Gesundheitsstudiengänge ist derzeit durch Barrieren wie die räumliche Trennung und verschiedene Studien- und Prüfungsordnungen erschwert. Sie benötigt dauerhafte Unterstützungsstrukturen auf hochschulischer und politischer Ebene.

  19. [The Coordinating Centres for Clinical Trials Network. Objectives and significance for research sites].

    PubMed

    Bruns, I; Maier-Lenz, H; Wolff, S

    2009-04-01

    In the late 1990s a funding program was set up by the federal German government to help keep stride with developments in the international research arena. Within this programme, Coordinating Centres for Clinical Trials ("Koordinierungszentren für Klinische Studien", KKS) were established at 12 German universities aiming at supporting all processes of academic clinical trials according to international standards. A close network infrastructure was chosen in order to reap maximum benefit from synergy effects and to promote the harmonisation of standards. Continuing to grow, the KKS Network currently has 16 research institutions as members. More than 400 employees within the KKS Network provide scientific services to clinical trials at universities, hospitals and in industry. In cooperation with study clinics, surgeries, study groups and competence networks in medicine within Europe and beyond, the KKS supports many different research projects covering all areas of medicine. The KKS Network contributes expertise to legislative processes within Germany and Europe through its work in professional committees and working groups. A wide range of education and training concepts supports clinical research as a scientific field in its own right. After nearly ten years the KKS Network has established itself as an indispensable partner in the field of clinical research.

  20. Minibeam radiation therapy for the management of osteosarcomas: A Monte Carlo study

    SciTech Connect

    Martínez-Rovira, I.; Prezado, Y.

    2014-06-15

    Purpose: Minibeam radiation therapy (MBRT) exploits the well-established tissue-sparing effect provided by the combination of submillimetric field sizes and a spatial fractionation of the dose. The aim of this work is to evaluate the feasibility and potential therapeutic gain of MBRT, in comparison with conventional radiotherapy, for osteosarcoma treatments. Methods: Monte Carlo simulations (PENELOPE/PENEASY code) were used as a method to study the dose distributions resulting from MBRT irradiations of a rat femur and a realistic human femur phantoms. As a figure of merit, peak and valley doses and peak-to-valley dose ratios (PVDR) were assessed. Conversion of absorbed dose to normalized total dose (NTD) was performed in the human case. Several field sizes and irradiation geometries were evaluated. Results: It is feasible to deliver a uniform dose distribution in the target while the healthy tissue benefits from a spatial fractionation of the dose. Very high PVDR values (⩾20) were achieved in the entrance beam path in the rat case. PVDR values ranged from 2 to 9 in the human phantom. NTD{sub 2.0} of 87 Gy might be reached in the tumor in the human femur while the healthy tissues might receive valley NTD{sub 2.0} lower than 20 Gy. The doses in the tumor and healthy tissues might be significantly higher and lower than the ones commonly delivered used in conventional radiotherapy. Conclusions: The obtained dose distributions indicate that a gain in normal tissue sparing might be expected. This would allow the use of higher (and potentially curative) doses in the tumor. Biological experiments are warranted.

  1. Influence of photon energy spectra from brachytherapy sources on Monte Carlo simulations of kerma and dose rates in water and air

    SciTech Connect

    Rivard, Mark J.; Granero, Domingo; Perez-Calatayud, Jose; Ballester, Facundo

    2010-02-15

    Purpose: For a given radionuclide, there are several photon spectrum choices available to dosimetry investigators for simulating the radiation emissions from brachytherapy sources. This study examines the dosimetric influence of selecting the spectra for {sup 192}Ir, {sup 125}I, and {sup 103}Pd on the final estimations of kerma and dose. Methods: For {sup 192}Ir, {sup 125}I, and {sup 103}Pd, the authors considered from two to five published spectra. Spherical sources approximating common brachytherapy sources were assessed. Kerma and dose results from GEANT4, MCNP5, and PENELOPE-2008 were compared for water and air. The dosimetric influence of {sup 192}Ir, {sup 125}I, and {sup 103}Pd spectral choice was determined. Results: For the spectra considered, there were no statistically significant differences between kerma or dose results based on Monte Carlo code choice when using the same spectrum. Water-kerma differences of about 2%, 2%, and 0.7% were observed due to spectrum choice for {sup 192}Ir, {sup 125}I, and {sup 103}Pd, respectively (independent of radial distance), when accounting for photon yield per Bq. Similar differences were observed for air-kerma rate. However, their ratio (as used in the dose-rate constant) did not significantly change when the various photon spectra were selected because the differences compensated each other when dividing dose rate by air-kerma strength. Conclusions: Given the standardization of radionuclide data available from the National Nuclear Data Center (NNDC) and the rigorous infrastructure for performing and maintaining the data set evaluations, NNDC spectra are suggested for brachytherapy simulations in medical physics applications.

  2. Backscatter factors and mass energy-absorption coefficient ratios for diagnostic radiology dosimetry.

    PubMed

    Benmakhlouf, Hamza; Bouchard, Hugo; Fransson, Annette; Andreo, Pedro

    2011-11-21

    Backscatter factors, B, and mass energy-absorption coefficient ratios, (μ(en)/ρ)(w, air), for the determination of the surface dose in diagnostic radiology were calculated using Monte Carlo simulations. The main purpose was to extend the range of available data to qualities used in modern x-ray techniques, particularly for interventional radiology. A comprehensive database for mono-energetic photons between 4 and 150 keV and different field sizes was created for a 15 cm thick water phantom. Backscattered spectra were calculated with the PENELOPE Monte Carlo system, scoring track-length fluence differential in energy with negligible statistical uncertainty; using the Monte Carlo computed spectra, B factors and (μ(en)/ρ)(w, air) were then calculated numerically for each energy. Weighted averaging procedures were subsequently used to convolve incident clinical spectra with mono-energetic data. The method was benchmarked against full Monte Carlo calculations of incident clinical spectra obtaining differences within 0.3-0.6%. The technique used enables the calculation of B and (μ(en)/ρ)(w, air) for any incident spectrum without further time-consuming Monte Carlo simulations. The adequacy of the extended dosimetry data to a broader range of clinical qualities than those currently available, while keeping consistency with existing data, was confirmed through detailed comparisons. Mono-energetic and spectra-averaged values were compared with published data, including those in ICRU Report 74 and IAEA TRS-457, finding average differences of 0.6%. Results are provided in comprehensive tables appropriated for clinical use. Additional qualities can easily be calculated using a designed GUI interface in conjunction with software to generate incident photon spectra.

  3. Effects of herbivorous birds on intertidal seagrass beds in the northern Wadden Sea

    NASA Astrophysics Data System (ADS)

    Nacken, M.; Reise, K.

    2000-07-01

    During autumn migration (September to December), brent geese (Branta b. bernicla) and wigeon (Anas penelope) feed on the seagrass Zostera noltii in the nearshore, upper tidal zone leeward of the island of Sylt (eastern North Sea). To graze on leaves and shoots above the sediment and on rhizomes and roots below, these birds reworked the entire upper 1 cm layer of sediment eight times within this 3-month period. In addition, brent geese excavated pits 3-10 cm deep by trampling in order to feed on below-ground phytomass. About 12% of the seagrass beds became pitted to an average depth of 4.5 cm. Using net exclosures, it was estimated that birds removed 34 g dry weight m-2 of above-ground and 28 g of below-ground phytomass. This corresponds to 45% of the phytomass in September. Of the overall loss of phytomass from September to December, 63% was caused by birds. Roughly half of the leaves fell off anyway until December and the other half were taken by the birds. Below the ground, phytomass remained almost constant where birds were excluded, while with birds phytomass of rhizomes and roots was halved. In spite of this strong effect, in the next vegetation period the blade density was lower at former exclosure sites compared to the ambient seagrass bed. The underlying process seems to be a self-inhibition of dense overwintering seagrass by mud accretion. Assuming our experimental results can be scaled up to the entire seagrass bed, we hypothesize that in the sheltered upper intertidal zone, seasonal erosion caused by herbivorous geese and ducks is necessary for the persistence of Z. noltii.

  4. Absorbed dose evaluation of Auger electron-emitting radionuclides: impact of input decay spectra on dose point kernels and S-values

    NASA Astrophysics Data System (ADS)

    Falzone, Nadia; Lee, Boon Q.; Fernández-Varea, José M.; Kartsonaki, Christiana; Stuchbery, Andrew E.; Kibédi, Tibor; Vallis, Katherine A.

    2017-03-01

    The aim of this study was to investigate the impact of decay data provided by the newly developed stochastic atomic relaxation model BrIccEmis on dose point kernels (DPKs - radial dose distribution around a unit point source) and S-values (absorbed dose per unit cumulated activity) of 14 Auger electron (AE) emitting radionuclides, namely 67Ga, 80mBr, 89Zr, 90Nb, 99mTc, 111In, 117mSn, 119Sb, 123I, 124I, 125I, 135La, 195mPt and 201Tl. Radiation spectra were based on the nuclear decay data from the medical internal radiation dose (MIRD) RADTABS program and the BrIccEmis code, assuming both an isolated-atom and condensed-phase approach. DPKs were simulated with the PENELOPE Monte Carlo (MC) code using event-by-event electron and photon transport. S-values for concentric spherical cells of various sizes were derived from these DPKs using appropriate geometric reduction factors. The number of Auger and Coster–Kronig (CK) electrons and x-ray photons released per nuclear decay (yield) from MIRD-RADTABS were consistently higher than those calculated using BrIccEmis. DPKs for the electron spectra from BrIccEmis were considerably different from MIRD-RADTABS in the first few hundred nanometres from a point source where most of the Auger electrons are stopped. S-values were, however, not significantly impacted as the differences in DPKs in the sub-micrometre dimension were quickly diminished in larger dimensions. Overestimation in the total AE energy output by MIRD-RADTABS leads to higher predicted energy deposition by AE emitting radionuclides, especially in the immediate vicinity of the decaying radionuclides. This should be taken into account when MIRD-RADTABS data are used to simulate biological damage at nanoscale dimensions.

  5. Absorbed dose evaluation of Auger electron-emitting radionuclides: impact of input decay spectra on dose point kernels and S-values.

    PubMed

    Falzone, Nadia; Lee, Boon Q; Fernández-Varea, José M; Kartsonaki, Christiana; Stuchbery, Andrew E; Kibédi, Tibor; Vallis, Katherine A

    2017-03-21

    The aim of this study was to investigate the impact of decay data provided by the newly developed stochastic atomic relaxation model BrIccEmis on dose point kernels (DPKs - radial dose distribution around a unit point source) and S-values (absorbed dose per unit cumulated activity) of 14 Auger electron (AE) emitting radionuclides, namely (67)Ga, (80m)Br, (89)Zr, (90)Nb, (99m)Tc, (111)In, (117m)Sn, (119)Sb, (123)I, (124)I, (125)I, (135)La, (195m)Pt and (201)Tl. Radiation spectra were based on the nuclear decay data from the medical internal radiation dose (MIRD) RADTABS program and the BrIccEmis code, assuming both an isolated-atom and condensed-phase approach. DPKs were simulated with the PENELOPE Monte Carlo (MC) code using event-by-event electron and photon transport. S-values for concentric spherical cells of various sizes were derived from these DPKs using appropriate geometric reduction factors. The number of Auger and Coster-Kronig (CK) electrons and x-ray photons released per nuclear decay (yield) from MIRD-RADTABS were consistently higher than those calculated using BrIccEmis. DPKs for the electron spectra from BrIccEmis were considerably different from MIRD-RADTABS in the first few hundred nanometres from a point source where most of the Auger electrons are stopped. S-values were, however, not significantly impacted as the differences in DPKs in the sub-micrometre dimension were quickly diminished in larger dimensions. Overestimation in the total AE energy output by MIRD-RADTABS leads to higher predicted energy deposition by AE emitting radionuclides, especially in the immediate vicinity of the decaying radionuclides. This should be taken into account when MIRD-RADTABS data are used to simulate biological damage at nanoscale dimensions.

  6. Absorbed dose simulations in near-surface regions using high dose rate Iridium-192 sources applied for brachytherapy

    NASA Astrophysics Data System (ADS)

    Moura, E. S.; Zeituni, C. A.; Sakuraba, R. K.; Gonçalves, V. D.; Cruz, J. C.; Júnior, D. K.; Souza, C. D.; Rostelato, M. E. C. M.

    2014-02-01

    Brachytherapy treatment with Iridium-192 high dose rate (HDR) sources is widely used for various tumours and it could be developed in many anatomic regions. Iridium-192 sources are inserted inside or close to the region that will be treated. Usually, the treatment is performed in prostate, gynaecological, lung, breast and oral cavity regions for a better clinical dose coverage compared with other techniques, such as, high energy photons and Cobalt-60 machines. This work will evaluate absorbed dose distributions in near-surface regions around Ir-192 HDR sources. Near-surface dose measurements are a complex task, due to the contribution of beta particles in the near-surface regions. These dose distributions should be useful for non-tumour treatments, such as keloids, and other non-intracavitary technique. For the absorbed dose distribution simulations the Monte Carlo code PENELOPE with the general code penEasy was used. Ir-192 source geometry and a Polymethylmethacrylate (PMMA) tube, for beta particles shield were modelled to yield the percentage depth dose (PDD) on a cubic water phantom. Absorbed dose simulations were realized at the central axis to yield the Ir-192 dose fall-off along central axis. The results showed that more than 99.2% of the absorbed doses (relative to the surface) are deposited in 5 cm depth but with slower rate at higher distances. Near-surface treatments with Ir-192 HDR sources yields achievable measurements and with proper clinical technique and accessories should apply as an alternative for treatment of lesions where only beta sources were used.

  7. Electron Irradiation of Conjunctival Lymphoma-Monte Carlo Simulation of the Minute Dose Distribution and Technique Optimization

    SciTech Connect

    Brualla, Lorenzo; Zaragoza, Francisco J.; Sempau, Josep; Wittig, Andrea; Sauerwein, Wolfgang

    2012-07-15

    Purpose: External beam radiotherapy is the only conservative curative approach for Stage I non-Hodgkin lymphomas of the conjunctiva. The target volume is geometrically complex because it includes the eyeball and lid conjunctiva. Furthermore, the target volume is adjacent to radiosensitive structures, including the lens, lacrimal glands, cornea, retina, and papilla. The radiotherapy planning and optimization requires accurate calculation of the dose in these anatomical structures that are much smaller than the structures traditionally considered in radiotherapy. Neither conventional treatment planning systems nor dosimetric measurements can reliably determine the dose distribution in these small irradiated volumes. Methods and Materials: The Monte Carlo simulations of a Varian Clinac 2100 C/D and human eye were performed using the PENELOPE and PENEASYLINAC codes. Dose distributions and dose volume histograms were calculated for the bulbar conjunctiva, cornea, lens, retina, papilla, lacrimal gland, and anterior and posterior hemispheres. Results: The simulated results allow choosing the most adequate treatment setup configuration, which is an electron beam energy of 6 MeV with additional bolus and collimation by a cerrobend block with a central cylindrical hole of 3.0 cm diameter and central cylindrical rod of 1.0 cm diameter. Conclusions: Monte Carlo simulation is a useful method to calculate the minute dose distribution in ocular tissue and to optimize the electron irradiation technique in highly critical structures. Using a voxelized eye phantom based on patient computed tomography images, the dose distribution can be estimated with a standard statistical uncertainty of less than 2.4% in 3 min using a computing cluster with 30 cores, which makes this planning technique clinically relevant.

  8. Stereotactic breast irradiation with kilovoltage x-ray beams

    NASA Astrophysics Data System (ADS)

    Garnica-Garza, H. M.

    2016-01-01

    The purpose of this work is to determine, using Monte Carlo simulation and a realistic patient model, the characteristics of the resultant absorbed dose distributions when breast tumors are irradiated using small-field stereotactic body radiation therapy (SBRT) with kilovoltage x-ray beams instead of the standard megavoltage energies currently in use. The Rensselaer Polytechnic Institute (RPI) female phantom was used to model a pair of small-field SBRT breast treatments: in one treatment the tumor at depth and another one with the tumor located close to the breast surface. Each treatment consisted of 300 circular beams aimed at the tumor from a plurality of positions. The PENELOPE Monte Carlo code was used to determine the absorbed dose distribution for each beam and subsequently an optimization algorithm determined each beam weight according to a set of prescription goals. Both kilo- and megavoltage beam treatments were modeled, the latter to be used as a reference. Cumulative dose-volume histograms for eleven structures were used to compare the kilovoltage and reference treatments. Integral dose values are also reported. Absorbed dose distributions for the target volumes as well as the organs at risk were within the parameters reported in a clinical trial for both treatments. While for the ipsilateral healthy breast tissue the megavoltage treatment does offer an advantage in terms of less volume irradiated to intermediate doses, for the contralateral structures, breast and lung, the low penetration ability of the kilovoltage treatment results in a lower maximum dose. Skin dose is higher for the kilovoltage treatment but still well within the tolerance limits reported in the clinical trial.

  9. Validation of the GEANT4 simulation of bremsstrahlung from thick targets below 3 MeV

    NASA Astrophysics Data System (ADS)

    Pandola, L.; Andenna, C.; Caccia, B.

    2015-05-01

    The bremsstrahlung spectra produced by electrons impinging on thick targets are simulated using the GEANT4 Monte Carlo toolkit. Simulations are validated against experimental data available in literature for a range of energy between 0.5 and 2.8 MeV for Al and Fe targets and for a value of energy of 70 keV for Al, Ag, W and Pb targets. The energy spectra for the different configurations of emission angles, energies and targets are considered. Simulations are performed by using the three alternative sets of electromagnetic models that are available in GEANT4 to describe bremsstrahlung. At higher energies (0.5-2.8 MeV) of the impinging electrons on Al and Fe targets, GEANT4 is able to reproduce the spectral shapes and the integral photon emission in the forward direction. The agreement is within 10-30%, depending on energy, emission angle and target material. The physics model based on the Penelope Monte Carlo code is in slightly better agreement with the measured data than the other two. However, all models over-estimate the photon emission in the backward hemisphere. For the lower energy study (70 keV), which includes higher-Z targets, all models systematically under-estimate the total photon yield, providing agreement between 10% and 50%. The results of this work are of potential interest for medical physics applications, where knowledge of the energy spectra and angular distributions of photons is needed for accurate dose calculations with Monte Carlo and other fluence-based methods.

  10. A new transmission methodology for quality assurance in radiotherapy based on radiochromic film measurements.

    PubMed

    do Amaral, Leonardo L; de Oliveira, Harley F; Pavoni, Juliana F; Sampaio, Francisco; Netto, Thomaz Ghilardi

    2015-09-01

    Despite individual quality assurance (QA) being recommended for complex techniques in radiotherapy (RT) treatment, the possibility of errors in dose delivery during therapeutic application has been verified. Therefore, it is fundamentally important to conduct in vivo QA during treatment. This work presents an in vivo transmission quality control methodology, using radiochromic film (RCF) coupled to the linear accelerator (linac) accessory holder. This QA methodology compares the dose distribution measured by the film in the linac accessory holder with the dose distribution expected by the treatment planning software. The calculated dose distribution is obtained in the coronal and central plane of a phantom with the same dimensions of the acrylic support used for positioning the film but in a source-to-detector distance (SDD) of 100 cm, as a result of transferring the IMRT plan in question with all the fields positioned with the gantry vertically, that is, perpendicular to the phantom. To validate this procedure, first of all a Monte Carlo simulation using PENELOPE code was done to evaluate the differences between the dose distributions measured by the film in a SDD of 56.8 cm and 100 cm. After that, several simple dose distribution tests were evaluated using the proposed methodology, and finally a study using IMRT treatments was done. In the Monte Carlo simulation, the mean percentage of points approved in the gamma function comparing the dose distribution acquired in the two SDDs were 99.92%±0.14%. In the simple dose distribution tests, the mean percentage of points approved in the gamma function were 99.85%±0.26% and the mean percentage differences in the normalization point doses were -1.41%. The transmission methodology was approved in 24 of 25 IMRT test irradiations. Based on these results, it can be concluded that the proposed methodology using RCFs can be applied for in vivo QA in RT treatments. PACS number: 87.55.Qr, 87.55.km, 87.55.N.

  11. SU-E-T-432: Field Size Influence On the Electron and Photon Spectra Within Small MV Field Detectors

    SciTech Connect

    Benmakhlouf, H; Andreo, P

    2015-06-15

    Purpose: To investigate the influence of photon field size on the electron and photon fluence spectra in the active volume of small field detectors. Methods: The PENELOPE MC system based usercode PenEasy was used to calculate the material influence on the spectra by scoring the differential fluence in inserts of silicon, carbon, phosphorus and aluminium having 3 mm diameter and height. The spectra were then calculated inside the active volume of eleven detectors (ion chambers and solid-state detectors) whose geometry was simulated with great detail. The inserts/detectors were placed at 10 cm depth in a 30 cm x 30 cm x 30 cm water phantom and irradiated with 2.5 MeV photons and Varian Clinac 6 MV beams of small, medium and large size. Results: For all configurations, photon spectra in the scoring volume were similar to that in a small water volume except for additional characteristic x-ray peaks resulting from the material itself and from the materials surrounding the detectors (i.e. high-Z shielding the silicon). Electron fluence calculated in the inserts were up to 60% larger than in water; the difference increased with material density and decreasing field size. MC-calculated doses were compared to analytically determined collision kerma and restricted cema (cut-off=15keV). For the inserts, with large and medium fields K-col agreed with MC-dose, but K-col overestimated the dose for small fields due to lack of lateral CPE. For the detectors, up to 15% differences between K-col and the MC-dose were found. For all configurations the C-delta and MC-dose agreed within ±2%. Conclusion: The most relevant findings were that shielding affects substantially the photon spectra and material conditions the electron spectra, their field size dependence varying with the geometry configuration. These affect the values of factors entering into relative dosimetry.

  12. Influence of phantom thickness and material on the backscatter factors for diagnostic x-ray beam dosimetry.

    PubMed

    Benmakhlouf, Hamza; Fransson, Annette; Andreo, Pedro

    2013-01-21

    Most of the existing backscatter factors for the dosimetry of clinical diagnostic x-ray beams have been calculated for 15 cm thick phantoms; these data are used for skin dose determinations which in general ignore the influence of phantom material and thickness. The former should strictly be required whenever dosimetry measurements are made on phantom materials different from those used for the backscatter factor calculations. The phantom or patient thickness is of special importance when skin dose determinations are made for infants or paediatric patients. In this work, the recently published formalism for reference dosimetry and comprehensive database of backscatter factors for clinical beams and water phantoms have been extended using two correction factors which account for phantom material and thickness. These were determined with simulations using the PENELOPE Monte Carlo system, for PMMA to analyse the influence of the phantom material relative to water, and for a broad range of thicknesses of water and PMMA to investigate the role of this parameter in patient dose estimates. The material correction factor was found to be in the range 3-10%, depending on the field size and the HVL. The thickness correction factor was in the range 2-12% for a 5 cm thick phantom and square field sizes between 5 and 35 cm, reaching a plateau of about ±1% for thicknesses beyond 13 cm. Expressions in the form of surface fits over the calculated data are provided which streamline the determination of backscatter factors for arbitrary thicknesses and phantom materials, as well as field sizes. Results demonstrate the inadequacy of using conventional backscatter factors (calculated for 15 cm thick phantoms) without correction factors that take into account the phantom material and its thickness.

  13. A new transmission methodology for quality assurance in radiotherapy based on radiochromic film measurements.

    PubMed

    do Amaral, Leonardo L; de Oliveira, Harley F; Pavoni, Juliana F; Sampaio, Franciso; Ghillardi Netto, Thomaz

    2015-09-08

    Despite individual quality assurance (QA) being recommended for complex techniques in radiotherapy (RT) treatment, the possibility of errors in dose delivery during therapeutic application has been verified. Therefore, it is fundamentally important to conduct in vivo QA during treatment. This work presents an in vivo transmission quality control methodology, using radiochromic film (RCF) coupled to the linear accelerator (linac) accessory holder. This QA methodology compares the dose distribution measured by the film in the linac accessory holder with the dose distribution expected by the treatment planning software. The calculated dose distribution is obtained in the coronal and central plane of a phantom with the same dimensions of the acrylic support used for positioning the film but in a source-to-detector distance (SDD) of 100 cm, as a result of transferring the IMRT plan in question with all the fields positioned with the gantry vertically, that is, perpendicular to the phantom. To validate this procedure, first of all a Monte Carlo simulation using PENELOPE code was done to evaluate the differences between the dose distributions measured by the film in a SDD of 56.8 cm and 100 cm. After that, several simple dose distribution tests were evaluated using the proposed methodology, and finally a study using IMRT treatments was done. In the Monte Carlo simulation, the mean percentage of points approved in the gamma function comparing the dose distribution acquired in the two SDDs were 99.92% ± 0.14%. In the simple dose distribution tests, the mean percentage of points approved in the gamma function were 99.85% ± 0.26% and the mean percentage differences in the normalization point doses were -1.41%. The transmission methodology was approved in 24 of 25 IMRT test irradiations. Based on these results, it can be concluded that the proposed methodology using RCFs can be applied for in vivo QA in RT treatments.

  14. Maximum-likelihood estimation of scatter components algorithm for x-ray coherent scatter computed tomography of the breast.

    PubMed

    Ghammraoui, Bahaa; Badal, Andreu; Popescu, Lucretiu M

    2016-04-21

    Coherent scatter computed tomography (CSCT) is a reconstructive x-ray imaging technique that yields the spatially resolved coherent-scatter cross section of the investigated object revealing structural information of tissue under investigation. In the original CSCT proposals the reconstruction of images from coherently scattered x-rays is done at each scattering angle separately using analytic reconstruction. In this work we develop a maximum likelihood estimation of scatter components algorithm (ML-ESCA) that iteratively reconstructs images using a few material component basis functions from coherent scatter projection data. The proposed algorithm combines the measured scatter data at different angles into one reconstruction equation with only a few component images. Also, it accounts for data acquisition statistics and physics, modeling effects such as polychromatic energy spectrum and detector response function. We test the algorithm with simulated projection data obtained with a pencil beam setup using a new version of MC-GPU code, a Graphical Processing Unit version of PENELOPE Monte Carlo particle transport simulation code, that incorporates an improved model of x-ray coherent scattering using experimentally measured molecular interference functions. The results obtained for breast imaging phantoms using adipose and glandular tissue cross sections show that the new algorithm can separate imaging data into basic adipose and water components at radiation doses comparable with Breast Computed Tomography. Simulation results also show the potential for imaging microcalcifications. Overall, the component images obtained with ML-ESCA algorithm have a less noisy appearance than the images obtained with the conventional filtered back projection algorithm for each individual scattering angle. An optimization study for x-ray energy range selection for breast CSCT is also presented.

  15. SU-E-J-51: Dose Response of Common Solid State Detectors in Homogeneous Transverse and Longitudinal Magnetic Fields

    SciTech Connect

    Reynolds, M; Fallone, B; Rathee, S

    2014-06-01

    Purpose: Solid state radiation detectors are often used for dose profiles and percent depth dose measurements. The dose response of selected solid state detectors is evaluated in varying transverse and longitudinal magnetic fields for eventual use in MR-Linac devices. Methods: A PTW 60003 and IBA PFD detector were modeled in the Monte Carlo code PENELOPE, incorporating a magnetic field which was varied in strength and oriented both transversely and longitudinally with respect to the incident photon beam. The detectors' long axis was in turn oriented either parallel or perpendicular to the photon beam. Dose to the active volume of each detector was scored, and its ratio to dose with zero magnetic field strength (dose response) was determined. Accuracy of the simulations was evaluated by measurements using both chambers taken at low field with a small electromagnet. Simulations were also performed in a water phantom to compare to the in air results. Results: Significant dose response was found in transverse field geometries, nearing 20% at 1.5T. The response is highly dependent on relative orientations to the magnetic field and photon beam, and on detector composition. Low field measurements confirm these results. In the presence of longitudinal magnetic fields, the detectors exhibit little dose response, reaching 0.5–1% at 1.5T regardless of detector orientation. Water tank simulations compared well to the in air simulations when not at the beam periphery, where in transverse magnetic fields only, the water tank simulations differed from the in air results. Conclusion: Transverse magnetic fields can cause large deviations in dose response, and are highly position orientation dependent. Comparatively, longitudinal magnetic fields exhibit little to no dose response in each detector as a function of magnetic field strength. Water tank simulations show longitudinal fields are generally easier to work with, but each detector must be evaluated separately.

  16. Sci—Thur AM: YIS - 04: Gold Nanoparticle Enhanced Arc Radiotherapy: A Monte Carlo Feasibility Study

    SciTech Connect

    Koger, B; Kirkby, C

    2014-08-15

    Introduction: The use of gold nanoparticles (GNPs) in radiotherapy has shown promise for therapeutic enhancement. In this study, we explore the feasibility of enhancing radiotherapy with GNPs in an arc-therapy context. We use Monte Carlo simulations to quantify the macroscopic dose-enhancement ratio (DER) and tumour to normal tissue ratio (TNTR) as functions of photon energy over various tumour and body geometries. Methods: GNP-enhanced arc radiotherapy (GEART) was simulated using the PENELOPE Monte Carlo code and penEasy main program. We simulated 360° arc-therapy with monoenergetic photon energies 50 – 1000 keV and several clinical spectra used to treat a spherical tumour containing uniformly distributed GNPs in a cylindrical tissue phantom. Various geometries were used to simulate different tumour sizes and depths. Voxel dose was used to calculate DERs and TNTRs. Inhomogeneity effects were examined through skull dose in brain tumour treatment simulations. Results: Below 100 keV, DERs greater than 2.0 were observed. Compared to 6 MV, tumour dose at low energies was more conformai, with lower normal tissue dose and higher TNTRs. Both the DER and TNTR increased with increasing cylinder radius and decreasing tumour radius. The inclusion of bone showed excellent tumour conformality at low energies, though with an increase in skull dose (40% of tumour dose with 100 keV compared to 25% with 6 MV). Conclusions: Even in the presence of inhomogeneities, our results show promise for the treatment of deep-seated tumours with low-energy GEART, with greater tumour dose conformality and lower normal tissue dose than 6 MV.

  17. Screening of repetitive motifs inside the genome of the flat oyster (Ostrea edulis): Transposable elements and short tandem repeats.

    PubMed

    Vera, Manuel; Bello, Xabier; Álvarez-Dios, Jose-Antonio; Pardo, Belen G; Sánchez, Laura; Carlsson, Jens; Carlsson, Jeanette E L; Bartolomé, Carolina; Maside, Xulio; Martinez, Paulino

    2015-12-01

    The flat oyster (Ostrea edulis) is one of the most appreciated molluscs in Europe, but its production has been greatly reduced by the parasite Bonamia ostreae. Here, new generation genomic resources were used to analyse the repetitive fraction of the oyster genome, with the aim of developing molecular markers to face this main oyster production challenge. The resulting oyster database, consists of two sets of 10,318 and 7159 unique contigs (4.8 Mbp and 6.8 Mbp in total length) representing the oyster's genome (WG) and haemocyte transcriptome (HT), respectively. A total of 1083 sequences were identified as TE-derived, which corresponded to 4.0% of WG and 1.1% of HT. They were clustered into 142 homology groups, most of which were assigned to the Penelope order of retrotransposons, and to the Helitron and TIR DNA-transposons. Simple repeats and rRNA pseudogenes, also made a significant contribution to the oyster's genome (0.5% and 0.3% of WG and HT, respectively).The most frequent short tandem repeats identified in WG were tetranucleotide motifs while trinucleotide motifs were in HT. Forty identified microsatellite loci, 20 from each database, were selected for technical validation. Success was much lower among WG than HT microsatellites (15% vs 55%), which could reflect higher variation in anonymous regions interfering with primer annealing. All microsatellites developed adjusted to Hardy-Weinberg proportions and represent a useful tool to support future breeding programmes and to manage genetic resources of natural flat oyster beds.

  18. COPPER-64 Production Studies with Natural Zinc Targets at Deuteron Energy up to 19 Mev and Proton Energy from 141 Down to 31 Mev

    NASA Astrophysics Data System (ADS)

    Bonardi, Mauro L.; Birattari, Claudio; Groppi, Flavia; Song Mainard, Hae; Zhuikov, Boris L.; Kokhanyuk, Vladimir M.; Lapshina, Elena V.; Mebel, Michail V.; Menapace, Enzo

    2004-07-01

    High specific activity no-carrier-added 64Cu is a β-/β+ emitting radionuclide of increasing interest for PET imaging, as well as systemic and targeted radioimmunotherapy of tumors. Its peculiarity of intense Auger emitter is still under investigation. The cross-sections for production of 64Cu from Zn target of natural isotopic composition were measured in the deuteron energy range from threshold up to 19 MeV and proton energy range from 141 down to 31 MeV. The stacked-foil technique was used at both K=38 cyclotron of JRC-Ispra of CEC, Italy and 160 MeV intersection point of INR proton-LINAC in Troitsk, Russia. Several Ga, Zn, Cu, Ni, Co, V, Fe and Mn radionuclides were detected in Zn targets at the EOB. Optimized irradiation conditions are reported as a function of deuteron energy and energy loss into the Zn target, as well as target irradiation time and cooling time after radiochemistry. The activity of n.c.a. 64Cu was measured through its only γ emission of 1346 keV (i.e. 0.473 % intensity) both by instrumental and radiochemical methods, due to the non-specificity of annihilation radiation at 511 keV. To this last purpose, it was necessary to carry out a selective radiochemical separation of GaIII radionuclides by liquid/liquid extraction from the bulk of irradiated Zn targets and other spallation products, which remained in the 7 M HCl aqueous phase. Anion exchange chromatography tests had been carried out to separate the 64Cu from all others radionuclides in n.c.a. form. Theoretical calculations of cross-sections were performed with codes EMPIRE II and PENELOPE for deuteron reactions and CEF model and HMS-ALICE hybrid model for proton reactions. The theoretical results are presented and compared with the experimental values.

  19. A robust procedure for verifying TomoTherapy Hi-Art™ source models for small fields

    NASA Astrophysics Data System (ADS)

    Hundertmark, B.; Sterpin, E.; Mackie, T.

    2011-06-01

    The dosimetric measurement and modeling of small radiation treatment fields (<2 × 2 cm2) are difficult to perform and prone to error. Measurements of small fields are often adversely influenced by the properties of the detectors used to make them. The dosimetric properties of small fields have been difficult to accurately model due to the effects of source occlusion caused by the collimating jaws. In this study, small longitudinal slice widths (SWs) of the TomoTherapy® Hi-Art® machine are characterized by performing dosimetric measurements topographically. By using a static gantry, opening the central 16 MLC leaves during the irradiations, and symmetrically scanning detectors 10 cm through each longitudinal SW, integral doses to a 'TomoTherapy equivalent' 10 × 10 cm2 area are topographically measured. To quantify the effects of source occlusion for TomoTherapy, a quantity referred to as the integral scanned dose to slice width ratio (D/SW) is introduced. (D/SW) ratios are measured for SWs ranging from 0.375 to 5 cm in size using ion chambers and a radiographic film. The measurements of the (D/SW) ratio are shown to be insensitive to the detectors used in this study. The (D/SW) ratios for TomoTherapy have values of unity in the range of SW sizes from 5 cm to approximately 2 cm. For SWs smaller than 2 cm in size, the source-occlusion effect substantially reduces the measured machine output and the value of the (D/SW) ratios. The topographic measurement method presented provides a way to directly evaluate the accuracy of the small-field source model parameters used in dose calculation algorithms. As an example, the electron source spot size of a Penelope Monte Carlo (MC) model of TomoTherapy was varied to match computed and measured (D/SW) ratios. It was shown that the MC results for small SW sizes were sensitive to that particular parameter.

  20. Metal levels in livers of waterfowl from Korea.

    PubMed

    Kim, Jungsoo; Oh, Jong-Min

    2012-04-01

    This study presents concentrations of heavy metals (iron, zinc, manganese, copper, lead and cadmium) in livers of white-fronted geese (Anser albifrons), eurasian wigeons (Anas penelope), mallards (Anas platyrhynchos) and spot-billed ducks (Anas poecilorhyncha) from Korea in February 2006 and 2008. Iron concentrations were significantly lower in spot-billed ducks than in other species (ANOVA, p<0.001). Zinc concentrations were greater in white-fronted geese and spot-billed ducks than in eurasian wigeons and mallards (ANOVA, p<0.001). Manganese and copper concentrations in white-fronted geese were significantly higher than in other species (ANOVA, p<0.001). Cadmium concentrations were significantly higher in mallards and spot-billed ducks than in white-fronted geese (ANOVA, p=0.007). However, lead concentrations did not differ among species. Iron, zinc, manganese and copper concentrations from this study were within the range of other waterfowl studies. Therefore, we suggest that essential elements such as iron, zinc, manganese and copper are within normal range and are maintained there by normal homeostatic mechanism. Twenty individuals (29.0 percent) exceeded the threshold level for abnormal lead exposure (5 μg/g dry weight) in waterfowl in this study and it is a higher proportion than in herons, egrets and owls from Korea. We suggest that the result was attributed to ingestion of lead shot and sinkers. However, cadmium concentrations in waterfowl except one specimen were within the background concentrations for wild birds. In livers of four waterfowl species found in Korea, lead and cadmium concentrations were similar to previously reported in other geese and ducks; except for poisoning of lead shot or sinkers as shown in earlier studies.

  1. Benchmarking and validation of a Geant4-SHADOW Monte Carlo simulation for dose calculations in microbeam radiation therapy.

    PubMed

    Cornelius, Iwan; Guatelli, Susanna; Fournier, Pauline; Crosbie, Jeffrey C; Sanchez Del Rio, Manuel; Bräuer-Krisch, Elke; Rosenfeld, Anatoly; Lerch, Michael

    2014-05-01

    Microbeam radiation therapy (MRT) is a synchrotron-based radiotherapy modality that uses high-intensity beams of spatially fractionated radiation to treat tumours. The rapid evolution of MRT towards clinical trials demands accurate treatment planning systems (TPS), as well as independent tools for the verification of TPS calculated dose distributions in order to ensure patient safety and treatment efficacy. Monte Carlo computer simulation represents the most accurate method of dose calculation in patient geometries and is best suited for the purpose of TPS verification. A Monte Carlo model of the ID17 biomedical beamline at the European Synchrotron Radiation Facility has been developed, including recent modifications, using the Geant4 Monte Carlo toolkit interfaced with the SHADOW X-ray optics and ray-tracing libraries. The code was benchmarked by simulating dose profiles in water-equivalent phantoms subject to irradiation by broad-beam (without spatial fractionation) and microbeam (with spatial fractionation) fields, and comparing against those calculated with a previous model of the beamline developed using the PENELOPE code. Validation against additional experimental dose profiles in water-equivalent phantoms subject to broad-beam irradiation was also performed. Good agreement between codes was observed, with the exception of out-of-field doses and toward the field edge for larger field sizes. Microbeam results showed good agreement between both codes and experimental results within uncertainties. Results of the experimental validation showed agreement for different beamline configurations. The asymmetry in the out-of-field dose profiles due to polarization effects was also investigated, yielding important information for the treatment planning process in MRT. This work represents an important step in the development of a Monte Carlo-based independent verification tool for treatment planning in MRT.

  2. Geant4 Monte Carlo simulation of energy loss and transmission and ranges for electrons, protons and ions

    NASA Astrophysics Data System (ADS)

    Ivantchenko, Vladimir

    Geant4 is a toolkit for Monte Carlo simulation of particle transport originally developed for applications in high-energy physics with the focus on experiments at the Large Hadron Collider (CERN, Geneva). The transparency and flexibility of the code has spread its use to other fields of research, e.g. radiotherapy and space science. The tool provides possibility to simulate complex geometry, transportation in electric and magnetic fields and variety of physics models of interaction of particles with media. Geant4 has been used for simulation of radiation effects for number of space missions. Recent upgrades of the toolkit released in December 2009 include new model for ion electronic stopping power based on the revised version of ICRU'73 Report increasing accuracy of simulation of ion transport. In the current work we present the status of Geant4 electromagnetic package for simulation of particle energy loss, ranges and transmission. This has a direct implication for simulation of ground testing setups at existing European facilities and for simulation of radiation effects in space. A number of improvements were introduced for electron and proton transport, followed by a thorough validation. It was the aim of the present study to validate the range against reference data from the United States National Institute of Standards and Technologies (NIST) ESTAR, PSTAR and ASTAR databases. We compared Geant4 and NIST ranges of electrons using different Geant4 models. The best agreement was found for Penelope, except at very low energies in heavy materials, where the Standard package gave better results. Geant4 proton ranges in water agreed with NIST within 1 The validation of the new ion model is performed against recent data on Bragg peak position in water. The data from transmission of carbon ions via various absorbers following Bragg peak in water demonstrate that the new Geant4 model significantly improves precision of ion range. The absolute accuracy of ion range

  3. Optimization of photon beam energies in gold nanoparticle enhanced arc radiation therapy using Monte Carlo methods.

    PubMed

    Koger, B; Kirkby, C

    2016-12-02

    As a recent area of development in radiation therapy, gold nanoparticle (GNP) enhanced radiation therapy has shown potential to increase tumour dose while maintaining acceptable levels of healthy tissue toxicity. In this study, the effect of varying photon beam energy in GNP enhanced arc radiation therapy (GEART) is quantified through the introduction of a dose scoring metric, and GEART is compared to a conventional radiotherapy treatment. The PENELOPE Monte Carlo code was used to model several simple phantoms consisting of a spherical tumour containing GNPs (concentration: 15 mg Au g(-1) tumour, 0.8 mg Au g(-1) normal tissue) in a cylinder of tissue. Several monoenergetic photon beams, with energies ranging from 20 keV to 6 MeV, as well as 100, 200, and 300 kVp spectral beams, were used to irradiate the tumour in a 360° arc treatment. A dose metric was then used to compare tumour and tissue doses from GEART treatments to a similar treatment from a 6 MV spectrum. This was also performed on a simulated brain tumour using patient computed tomography data. GEART treatments showed potential over the 6 MV treatment for many of the simulated geometries, delivering up to 88% higher mean dose to the tumour for a constant tissue dose, with the effect greatest near a source energy of 50 keV. This effect is also seen with the inclusion of bone in a brain treatment, with a 14% increase in mean tumour dose over 6 MV, while still maintaining acceptable levels of dose to the bone and brain.

  4. Maximum-likelihood estimation of scatter components algorithm for x-ray coherent scatter computed tomography of the breast

    NASA Astrophysics Data System (ADS)

    Ghammraoui, Bahaa; Badal, Andreu; Popescu, Lucretiu M.

    2016-04-01

    Coherent scatter computed tomography (CSCT) is a reconstructive x-ray imaging technique that yields the spatially resolved coherent-scatter cross section of the investigated object revealing structural information of tissue under investigation. In the original CSCT proposals the reconstruction of images from coherently scattered x-rays is done at each scattering angle separately using analytic reconstruction. In this work we develop a maximum likelihood estimation of scatter components algorithm (ML-ESCA) that iteratively reconstructs images using a few material component basis functions from coherent scatter projection data. The proposed algorithm combines the measured scatter data at different angles into one reconstruction equation with only a few component images. Also, it accounts for data acquisition statistics and physics, modeling effects such as polychromatic energy spectrum and detector response function. We test the algorithm with simulated projection data obtained with a pencil beam setup using a new version of MC-GPU code, a Graphical Processing Unit version of PENELOPE Monte Carlo particle transport simulation code, that incorporates an improved model of x-ray coherent scattering using experimentally measured molecular interference functions. The results obtained for breast imaging phantoms using adipose and glandular tissue cross sections show that the new algorithm can separate imaging data into basic adipose and water components at radiation doses comparable with Breast Computed Tomography. Simulation results also show the potential for imaging microcalcifications. Overall, the component images obtained with ML-ESCA algorithm have a less noisy appearance than the images obtained with the conventional filtered back projection algorithm for each individual scattering angle. An optimization study for x-ray energy range selection for breast CSCT is also presented.

  5. Monte Carlo modeling provides accurate calibration factors for radionuclide activity meters.

    PubMed

    Zagni, F; Cicoria, G; Lucconi, G; Infantino, A; Lodi, F; Marengo, M

    2014-12-01

    Accurate determination of calibration factors for radionuclide activity meters is crucial for quantitative studies and in the optimization step of radiation protection, as these detectors are widespread in radiopharmacy and nuclear medicine facilities. In this work we developed the Monte Carlo model of a widely used activity meter, using the Geant4 simulation toolkit. More precisely the "PENELOPE" EM physics models were employed. The model was validated by means of several certified sources, traceable to primary activity standards, and other sources locally standardized with spectrometry measurements, plus other experimental tests. Great care was taken in order to accurately reproduce the geometrical details of the gas chamber and the activity sources, each of which is different in shape and enclosed in a unique container. Both relative calibration factors and ionization current obtained with simulations were compared against experimental measurements; further tests were carried out, such as the comparison of the relative response of the chamber for a source placed at different positions. The results showed a satisfactory level of accuracy in the energy range of interest, with the discrepancies lower than 4% for all the tested parameters. This shows that an accurate Monte Carlo modeling of this type of detector is feasible using the low-energy physics models embedded in Geant4. The obtained Monte Carlo model establishes a powerful tool for first instance determination of new calibration factors for non-standard radionuclides, for custom containers, when a reference source is not available. Moreover, the model provides an experimental setup for further research and optimization with regards to materials and geometrical details of the measuring setup, such as the ionization chamber itself or the containers configuration.

  6. Optimization of photon beam energies in gold nanoparticle enhanced arc radiation therapy using Monte Carlo methods

    NASA Astrophysics Data System (ADS)

    Koger, B.; Kirkby, C.

    2016-12-01

    As a recent area of development in radiation therapy, gold nanoparticle (GNP) enhanced radiation therapy has shown potential to increase tumour dose while maintaining acceptable levels of healthy tissue toxicity. In this study, the effect of varying photon beam energy in GNP enhanced arc radiation therapy (GEART) is quantified through the introduction of a dose scoring metric, and GEART is compared to a conventional radiotherapy treatment. The PENELOPE Monte Carlo code was used to model several simple phantoms consisting of a spherical tumour containing GNPs (concentration: 15 mg Au g-1 tumour, 0.8 mg Au g-1 normal tissue) in a cylinder of tissue. Several monoenergetic photon beams, with energies ranging from 20 keV to 6 MeV, as well as 100, 200, and 300 kVp spectral beams, were used to irradiate the tumour in a 360° arc treatment. A dose metric was then used to compare tumour and tissue doses from GEART treatments to a similar treatment from a 6 MV spectrum. This was also performed on a simulated brain tumour using patient computed tomography data. GEART treatments showed potential over the 6 MV treatment for many of the simulated geometries, delivering up to 88% higher mean dose to the tumour for a constant tissue dose, with the effect greatest near a source energy of 50 keV. This effect is also seen with the inclusion of bone in a brain treatment, with a 14% increase in mean tumour dose over 6 MV, while still maintaining acceptable levels of dose to the bone and brain.

  7. WE-D-BRF-01: FEATURED PRESENTATION - Investigating Particle Track Structures Using Fluorescent Nuclear Track Detectors and Monte Carlo Simulations

    SciTech Connect

    Dowdell, S; Paganetti, H; Schuemann, J; Greilich, S; Zimmerman, F; Evans, C

    2014-06-15

    Purpose: To report on the efforts funded by the AAPM seed funding grant to develop the basis for fluorescent nuclear track detector (FNTD) based radiobiological experiments in combination with dedicated Monte Carlo simulations (MCS) on the nanometer scale. Methods: Two confocal microscopes were utilized in this study. Two FNTD samples were used to find the optimal microscope settings, one FNTD irradiated with 11.1 MeV/u Gold ions and one irradiated with 428.77 MeV/u Carbon ions. The first sample provided a brightly luminescent central track while the latter is used to test the capabilities to observe secondary electrons. MCS were performed using TOPAS beta9 version, layered on top of Geant4.9.6p02. Two sets of simulations were performed, one with the Geant4-DNA physics list and approximating the FNTDs by water, a second set using the Penelope physics list in a water-approximated FNTD and a aluminum-oxide FNTD. Results: Within the first half of the funding period, we have successfully established readout capabilities of FNTDs at our institute. Due to technical limitations, our microscope setup is significantly different from the approach implemented at the DKFZ, Germany. However, we can clearly reconstruct Carbon tracks in 3D with electron track resolution of 200 nm. A second microscope with superior readout capabilities will be tested in the second half of the funding period, we expect an improvement in signal to background ratio with the same the resolution.We have successfully simulated tracks in FNTDs. The more accurate Geant4-DNA track simulations can be used to reconstruct the track energy from the size and brightness of the observed tracks. Conclusion: We have achieved the goals set in the seed funding proposal: the setup of FNTD readout and simulation capabilities. We will work on improving the readout resolution to validate our MCS track structures down to the nanometer scales.

  8. Monte Carlo calculation of specific absorbed fractions: variance reduction techniques

    NASA Astrophysics Data System (ADS)

    Díaz-Londoño, G.; García-Pareja, S.; Salvat, F.; Lallena, A. M.

    2015-04-01

    The purpose of the present work is to calculate specific absorbed fractions using variance reduction techniques and assess the effectiveness of these techniques in improving the efficiency (i.e. reducing the statistical uncertainties) of simulation results in cases where the distance between the source and the target organs is large and/or the target organ is small. The variance reduction techniques of interaction forcing and an ant colony algorithm, which drives the application of splitting and Russian roulette, were applied in Monte Carlo calculations performed with the code penelope for photons with energies from 30 keV to 2 MeV. In the simulations we used a mathematical phantom derived from the well-known MIRD-type adult phantom. The thyroid gland was assumed to be the source organ and urinary bladder, testicles, uterus and ovaries were considered as target organs. Simulations were performed, for each target organ and for photons with different energies, using these variance reduction techniques, all run on the same processor and during a CPU time of 1.5 · 105 s. For energies above 100 keV both interaction forcing and the ant colony method allowed reaching relative uncertainties of the average absorbed dose in the target organs below 4% in all studied cases. When these two techniques were used together, the uncertainty was further reduced, by a factor of 0.5 or less. For photons with energies below 100 keV, an adapted initialization of the ant colony algorithm was required. By using interaction forcing and the ant colony algorithm, realistic values of the specific absorbed fractions can be obtained with relative uncertainties small enough to permit discriminating among simulations performed with different Monte Carlo codes and phantoms. The methodology described in the present work can be employed to calculate specific absorbed fractions for arbitrary arrangements, i.e. energy spectrum of primary radiation, phantom model and source and target organs.

  9. Denoising techniques combined to Monte Carlo simulations for the prediction of high-resolution portal images in radiotherapy treatment verification

    NASA Astrophysics Data System (ADS)

    Lazaro, D.; Barat, E.; Le Loirec, C.; Dautremer, T.; Montagu, T.; Guérin, L.; Batalla, A.

    2013-05-01

    This work investigates the possibility of combining Monte Carlo (MC) simulations to a denoising algorithm for the accurate prediction of images acquired using amorphous silicon (a-Si) electronic portal imaging devices (EPIDs). An accurate MC model of the Siemens OptiVue1000 EPID was first developed using the penelope code, integrating a non-uniform backscatter modelling. Two already existing denoising algorithms were then applied on simulated portal images, namely the iterative reduction of noise (IRON) method and the locally adaptive Savitzky-Golay (LASG) method. A third denoising method, based on a nonparametric Bayesian framework and called DPGLM (for Dirichlet process generalized linear model) was also developed. Performances of the IRON, LASG and DPGLM methods, in terms of smoothing capabilities and computation time, were compared for portal images computed for different values of the RMS pixel noise (up to 10%) in three different configurations, a heterogeneous phantom irradiated by a non-conformal 15 × 15 cm2 field, a conformal beam from a pelvis treatment plan, and an IMRT beam from a prostate treatment plan. For all configurations, DPGLM outperforms both IRON and LASG by providing better smoothing performances and demonstrating a better robustness with respect to noise. Additionally, no parameter tuning is required by DPGLM, which makes the denoising step very generic and easy to handle for any portal image. Concerning the computation time, the denoising of 1024 × 1024 images takes about 1 h 30 min, 2 h and 5 min using DPGLM, IRON, and LASG, respectively. This paper shows the feasibility to predict within a few hours and with the same resolution as real images accurate portal images, combining MC simulations with the DPGLM denoising algorithm.

  10. Innovative Conditioning Procedures for the Generation of Radioactive Waste Products which are Stable for Intermediate Storage or Repository-Independent in Final Storage

    SciTech Connect

    Steinmetz, H.J.; Heimbach, H.; Odoj, R.; Pruesse, R.; Wartenberg, W.

    2006-07-01

    The German Federal Government aims at a future final storage site for all kinds of radioactive waste within 30 years. Existing and newly-produced radioactive waste therefore has to be stored in interim storage facilities over very long periods of time. At present, most German radioactive waste or waste packages are produced and qualified according to the acceptance criteria of the projected final repository KONRAD. [1] Nevertheless, conditioning strategies for crude radioactive waste have to take into account the open question of the future repository site as well as requirements for long-term interim storage. The Quality Control Group for Radioactive Waste (in German: Produktkontrollstelle fuer radioaktive Abfaelle - PKS) works as an independent expert organisation for the quality checking of radioactive waste packages as well as evaluating conditioning procedures for waste containers suitable for final storage on behalf of the Federal Office for Radiation Protection (in German: Bundesamt fuer Strahlenschutz - BfS). The Institute for Safety Research and Reactor Technology (in German: Institut fuer Sicherheitsforschung and Reaktortechnik - ISR) of the Research Centre Juelich investigates scientific/technical problems of nuclear disposal, especially in the field of waste treatment. In this context, ISR and PKS investigated and/or evaluated innovative procedures, by means of which radioactive waste flows may be minimized and rendered inert. QSA Global (formerly: AEA Technology QSA) conditions radioactive waste of German users from the fields of medicine, research and industry as well as from its own radioactive source production and operates an intermediate storage facility for radioactive waste containers. This poster deals with the characteristics and possible applications of new waste fixation media on the basis of organic and inorganic mineral polymers; with the approach of producing inherently safe waste forms for various geological formations. Plasma technology

  11. The Nagra-DOE Cooperative Project

    SciTech Connect

    Long, J.C.S.; Levitch, R.A.; Zuidema, P.

    1993-04-01

    The Nagra-DOE Cooperative (NDC-I) research program was sponsored by the US Department of Energy (DOE) through the Lawrence Berkeley Laboratory (LBL), and the Swiss Nationale Genossenschaft fuer die Lagerung radioaktiver Abfaella (Nagra). Scientists participating in this project explored the geological, geophysical, hydrological, geochemical, and structural effects anticipated from the use of a rock mass as a geologic repository for nuclear waste. Six joint tasks were defined and are described briefly below. Tasks 1, 2, 3 and 5 were concerned with the characterization of fractured rock. Task 5 in particular was focused on investigations at the Grimsel Underground Laboratory in the Swiss Alps. Tasks 2 and 6 focused on the phenomenology associated with storing radioactive waste underground.

  12. Highlights from the 2013 International Sherwood Fusion Theory Conference, Santa Fe, NM

    SciTech Connect

    2013-04-15

    The 2013 International Sherwood Fusion Theory Conference was held in Santa Fe, NM from April 15-17. There were 15 invited talks spanning the field of fusion theory on topics such as stellerator theory, intrinsic rotation in tokamaks, transport in the plasma edge, and plasma-wall interactions. Author-provided summaries of several of the invited talks are included on pages 5 to 10 of this document. Plenary talks were given by Per Helander (Max-Planck-Institut fuer Plasmaphysik, Greifswald, Germany) on “Overview of recent developments in stellerator theory”, Amit Misra (Los Alamos National Laboratory) on “Stable storage of Helium at interfaces in nanocomposites”, Sergei Krasheninnikov (UC San Diego) on “On the physics of the first wall in fusion devices”, and Stuart Bale (UC Berkeley) on “Solar wind thermodynamics and turbulence: collisional – collisionless transitions”.

  13. Proceedings of the 8th high energy heavy ion study

    SciTech Connect

    Harris, J.W.; Wozniak, G.J.

    1988-01-01

    This was the eighth in a series of conferences jointly sponsored by the Nuclear Science Division of LBL and the Gesellschaft fuer Schwerionenforschung in West Germany. Sixty papers on current research at both relativistic and intermediate energies are included in this report. Topics covered consisted of: Equation of State of Nuclear Matter, Pion and High Energy Gamma Emission, Theory of Multifragmentation, Intermediate Energies, Fragmentation, Atomic Physics, Nuclear Structure, Electromagnetic Processes, and New Facilities planned for SIS-ESR. The latest design parameters of the Bevalac Upgrade Proposal were reviewed for the user community. Also, the design of a new electronic 4..pi.. detector, a time projection chamber which would be placed at the HISS facility, was presented.

  14. The NGS Pyramid wavefront sensor for ERIS

    NASA Astrophysics Data System (ADS)

    Riccardi, A.; Antichi, J.; Quirós-Pacheco, F.; Esposito, S.; Carbonaro, L.; Agapito, G.; Biliotti, V.; Briguglio, R.; Di Rico, G.; Dolci, M.; Ferruzzi, D.; Pinna, E.; Puglisi, A.; Xompero, M.; Marchetti, E.; Fedrigo, E.; Le Louarn, M.; Conzelmann, R.; Delabre, B.; Amico, P.; Hubin, N.

    2014-07-01

    ERIS is the new Single Conjugate Adaptive Optics (AO) instrument for VLT in construction at ESO with the collaboration of Max-Planck Institut fuer Extraterrestrische Physik, ETH-Institute for Astronomy and INAF - Osservatorio Astrofisico di Arcetri. The ERIS AO system relies on a 40×40 sub-aperture Pyramid Wavefront Sensor (PWFS) for two operating modes: a pure Natural Guide Star high-order sensing for high Strehl and contrast correction and a low-order visible sensing in support of the Laser Guide Star AO mode. In this paper we present in detail the preliminary design of the ERIS PWFS that is developed under the responsibility of INAF-Osservatorio Astrofisico di Arcetri in collaboration with ESO.

  15. The ERIS adaptive optics system

    NASA Astrophysics Data System (ADS)

    Riccardi, A.; Esposito, S.; Agapito, G.; Antichi, J.; Biliotti, V.; Blain, C.; Briguglio, R.; Busoni, L.; Carbonaro, L.; Di Rico, G.; Giordano, C.; Pinna, E.; Puglisi, A.; Spanò, P.; Xompero, M.; Baruffolo, A.; Kasper, M.; Egner, S.; Suàrez Valles, M.; Soenke, C.; Downing, M.; Reyes, J.

    2016-07-01

    ERIS is the new AO instrument for VLT-UT4 led by a Consortium of Max-Planck Institut fuer Extraterrestrische Physik, UK-ATC, ETH-Zurich, ESO and INAF. The ERIS AO system provides NGS mode to deliver high contrast correction and LGS mode to extend high Strehl performance to large sky coverage. The AO module includes NGS and LGS wavefront sensors and, with VLT-AOF Deformable Secondary Mirror and Laser Facility, will provide AO correction to the high resolution imager NIX (1-5um) and the IFU spectrograph SPIFFIER (1-2.5um). In this paper we present the preliminary design of the ERIS AO system and the estimated correction performance.

  16. An intelligent ground operator support system

    NASA Technical Reports Server (NTRS)

    Goerlach, Thomas; Ohlendorf, Gerhard; Plassmeier, Frank; Bruege, Uwe

    1994-01-01

    This paper presents first results of the project 'Technologien fuer die intelligente Kontrolle von Raumfahrzeugen' (TIKON). The TIKON objective was the demonstration of feasibility and profit of the application of artificial intelligence in the space business. For that purpose a prototype system has been developed and implemented for the operation support of the Roentgen Satellite (ROSAT), a scientific spacecraft designed to perform the first all-sky survey with a high-resolution X-ray telescope and to investigate the emission of specific celestial sources. The prototype integrates a scheduler and a diagnosis tool both based on artificial intelligence techniques. The user interface is menu driven and provides synoptic displays for the visualization of the system status. The prototype has been used and tested in parallel to an already existing operational system.

  17. Dedicated Max-Planck beamline for the in situ investigation of interfaces and thin films

    SciTech Connect

    Stierle, A.; Steinhaeuser, A.; Ruehm, A.; Renner, F.U.; Weigel, R.; Kasper, N.; Dosch, H.

    2004-12-01

    A dedicated beamline for the Max-Planck-Institut fuer Metallforschung was recently taken into operation at the Angstroemquelle Karlsruhe (ANKA). Here we describe the layout of the beamline optics and the experimental end-station, consisting of a heavy duty multiple circle diffractometer. For both a new design was realized, combining a maximum flexibility in the beam properties [white, pink (focused) monochromatic, energy range 6-20 keV] with a special diffractometer for heavy sample environments up to 500 kg, that can be run in different geometrical modes. In addition the angular-reciprocal space transformations for the diffractometer in use are derived, which allows an operation of the instrument in the convenient six circle mode. As an example, results from surface x-ray diffraction on a Cu{sub 3}Au(111) single crystal are presented.

  18. Thick Nano-Crystalline Diamond films for fusion applications

    SciTech Connect

    Dawedeit, Christoph

    2010-06-30

    This Diplomarbeit deals with the characterization of 9 differently grown diamond samples. Several techniques were used to determine the quality of these specimens for inertial confinement fusion targets. The quality of chemical vapor deposition diamond is usually considered in terms of the proportion of sp3-bonded carbon to sp2-bonded carbon in the sample. For fusion targets smoothness, Hydrogen content and density of the diamonds are further important characteristics. These characteristics are analyzed in this thesis. The research for thesis was done at Lawrence Livermore National Laboratory in collaboration with the Fraunhofer Institut für angewandte Festkörperphysik Freiburg, Germany. Additionally the Lehrstuhl fuer Nukleartechnik at Technical University of Germany supported the work.

  19. Rocket- and aircraft-borne trace gas measurements in the winter polar stratosphere

    NASA Technical Reports Server (NTRS)

    Arnold, F.; Moehler, O.; Pfeilsticker, K.; Ziereis, H.

    1988-01-01

    In January and February 1987 stratospheric rocket- and aircraft-borne trace gas measurements were done in the North Polar region using ACIMS (Active Chemical Ionization Mass Spectrometry) and PACIMS (PAssive Chemical Ionization Mass Spectrometry) instruments. The rocket was launched at ESRANGE (European Sounding Rocket Launching Range) (68 N, 21 E, Northern Sweden) and the twin-jet research aircraft operated by the DFVLR (Deutsche Forschungs- und Versuchs-anstalt fuer Luft- und Raumfahrt), and equipped with a mass spectrometer laboratory was stationed at Kiruna airport. Various stratospheric trace gases were measured including nitric acid, sulfuric acid, non-methane hydrocarbons (acetone, hydrogen cyanide, acetonitrile, methanol etc.), and ambient cluster ions. The experimental data is presented and possible implications for polar stratospheric ozone discussed.

  20. CRYOGENIC AND VACUUM TECHNOLOGICAL ASPECTS OF THE LOW-ENERGY ELECTROSTATIC CRYOGENIC STORAGE RING

    SciTech Connect

    Orlov, D. A.; Lange, M.; Froese, M.; Hahn, R. von; Grieser, M.; Mallinger, V.; Sieber, T.; Weber, T.; Wolf, A.; Rappaport, M.

    2008-03-16

    The cryogenic and vacuum concepts for the electrostatic Cryogenic ion Storage Ring (CSR), under construction at the Max-Planck-Institut fuer Kernphysik in Heidelberg, is presented. The ring will operate in a broad temperature range from 2 to 300 K and is required to be bakeable up to 600 K. Extremely high vacuum and low temperatures are necessary to achieve long lifetimes of the molecular ions stored in the ring so that the ions will have enough time to cool by radiation to their vibrational and rotational ground states. To test cryogenic and vacuum technological aspects of the CSR, a prototype is being built and will be connected to the commercial cryogenic refrigerator recently installed, including a specialized 2-K connection system. The first results and the status of current work with the prototype are also presented.

  1. Reconstruction of π0 and η mesons via conversion method in Au+Au at 1.23 GeV/u with HADES

    NASA Astrophysics Data System (ADS)

    Behnke, C.; HADES Collaboration

    2015-04-01

    Lepton pairs emerging from decays of virtual photons represent promising probes of matter under extreme conditions. In the energy domain of 1 - 2 GeV per nucleon, the HADES experiment at GSI Helmholtzzentrum fuer Schwerionenforschung in Darmstadt studies di-electrons and strangeness production in various reactions, i.e. collisions of pions, protons, deuterons, heavy-ions, and nuceous with nuclei. An accurate determination of the medium radiation depends on a precise knowledge of the underlying hadronic cocktail composed of various sources contributing to the net spectra. Therefore, a measurement of the neutral meson yields together with the dileptons is crucial. In this contribution, the capability of HADES to detect e+e- pairs from conversion of real photons will be demonstrated. We will present results from a two-photon analysis of Au+Au collisions at 1.23 GeV/u providing information on neutral π0 and η mesons.

  2. Key issues recently treated within the French-German safety approach

    SciTech Connect

    Frisch, W.; Gros, G.

    1997-12-01

    The development of the common French-German safety approach for future PWRs started in 1992. The general approach was issued in May 1993. It was accomplished on three working levels: the technical safety organizations GRS (Gesellschaft for Anlagen- und Reaktorsicherheit) and IPSN (Institut de Protection et de Surete Nucleaire) developed the technical basis, advisory groups GPR (Groupe Permanent charge des Reacteurs Nucleaires) and RSK (Reaktorsicherheitskom-mission) developed common recommendations, and the authorities BMU (Bundesministerium fuer Naturschutz, Umwelt und Reaktorsicherheit) and DSIN (Direction de la surete des Installations Nucleaires) issued the common safety approach. It contains safety objectives and general principles. The common approach has been presented at the ARS`94 Conference. Some important objectives and principles are briefly summarized in this paper, and the results of this work are described. 4 refs.

  3. Evidence-based (S3) Guideline on (anogenital) Lichen sclerosus.

    PubMed

    Kirtschig, G; Becker, K; Günthert, A; Jasaitiene, D; Cooper, S; Chi, C-C; Kreuter, A; Rall, K K; Aberer, W; Riechardt, S; Casabona, F; Powell, J; Brackenbury, F; Erdmann, R; Lazzeri, M; Barbagli, G; Wojnarowska, F

    2015-10-01

    Lichen sclerosus (LS) is an inflammatory skin disease that usually involves the anogenital area. All patients with symptoms or signs suspicious of lichen sclerosus should be seen at least once initially by a physician with a special interest in the disease in order to avoid delay in diagnosis, as early treatment may cure the disease in some and reduce or prevent scarring. The diagnosis is made clinically in most cases. Biopsies should only be performed under certain circumstances. The gold standard for treatment remains potent to very potent topical steroids; however, mild and moderate disease in boys and men may be cured by circumcision. Certain triggers should be avoided. http://www.euroderm.org/images/stories/guidelines/2014/S3-Guideline-on-Lichen-sclerosus.pdf http://www.awmf.org/fachgesellschaften/mitgliedsgesellschaften/visitenkarte/fg/deutsche-gesellschaft-fuer-gynaekologie-und-geburtshilfe-dggg.html.

  4. Artificial modification meeting reminder

    NASA Astrophysics Data System (ADS)

    Gordon, W. E.

    A symposium on artificial modification of the ionosphere by high-powered radio waves (V. V. Migulin, Honorary Chairman) will be held September 19-23, 1988, at the Scandic Hotel, Tromso, Norway. The symposium, sponsored by Union Radio Scientifique Internationale Commissions (URSI) G and H, is in the URSI series which started at Suzdal in 1983. Information on the scientific program is available from V.V. Migulin, U.S.S.R. Academy of Sciences, 103907, Moscow Center, Marx Avl8, U.S.S.R.; Peter Stubbe, Max- Planck-Institut fuer Aeronomy, D-3411 Katlenburg- Lindau 3, Federal Republic of Germany; or W.E. Gordon, Rice University, Space Physics and Astronomy Dept., Houston, TX 77251. For local arrangements information, contact Asgeir Brekke, Institute Matematisk Realfag, Aurora Observatory, Box 953, N-9001, Tromso, Norway.

  5. Observation of Spontaneous Neoclassical Tearing Modes

    SciTech Connect

    E.D. Fredrickson

    2001-10-03

    We present data in this paper from the Tokamak Fusion Test Reactor (TFTR) which challenges the commonly held belief that extrinsic MHD events such as sawteeth or ELMs [edge localized modes] are required to provide the seed islands that trigger Neoclassical Tearing Modes (NTMs). While sawteeth are reported to provide the trigger for most of the NTMs on DIII-D [at General Atomics in San Diego, California] and ASDEX-U [at Max-Planck-Institut fuer Plasmaphysik in Garching, Germany], the majority of NTMs seen in TFTR occur in plasmas without sawteeth, that is which are above the beta threshold for sawtooth stabilization. Examples of NTMs appearing in the absence of any detectable extrinsic MHD activity will be shown. Conversely, large n=1 modes in plasmas above the NTM beta threshold generally do not trigger NTMs. An alternative mechanism for generating seed islands will be discussed.

  6. Precision SAW filters for a large phased-array radar system

    NASA Astrophysics Data System (ADS)

    Haydl, W. H.; Sander, W.; Wirth, W.-D.

    1981-05-01

    The electronically steerable radar (ELRA) at the Forschungsinstitut fuer Funk und Mathematik is an experimental S-band phased-array radar system consisting of separate transmitting and receiving arrays employing several coherent and incoherent signal-processing and data-handling techniques, incorporating multiple beam and multifunction operation for target search and tracking, adaptive interference suppression, and target resolution. This paper deals with the development and application of two types of SAW filters for the IF amplifier channel of the receiving array. Compared to conventional filters with lumped elements, these filters have some important merits. By making use of a special tuning technique, the center frequencies of all filters were adjusted, resulting in an rms deviation of less than 1 kHz. One type of the SAW filters represents an almost ideal approach of realizing a matched filter for rectangular shaped pulses. The conformity of the frequency responses of several hundred filters improved the noise suppression capability of the system.

  7. Mechanism of 'GSI oscillations' in electron capture by highly charged hydrogen-like atomic ions

    SciTech Connect

    Krainov, V. P.

    2012-07-15

    We suggest a qualitative explanation of oscillations in electron capture decays of hydrogen-like {sup 140}Pr and {sup 142}Pm ions observed recently in an ion experimental storage ring (ESR) of Gesellschaft fuer Schwerionenforschung (GSI) mbH, Darmstadt, Germany. This explanation is based on the electron multiphoton Rabi oscillations between two Zeeman states of the hyperfine ground level with the total angular momentum F = 1/2. The Zeeman splitting is produced by a constant magnetic field in the ESR. Transitions between these states are produced by the second, sufficiently strong alternating magnetic field that approximates realistic fields in the GSI ESR. The Zeeman splitting amounts to only about 10{sup -5} eV. This allows explaining the observed quantum beats with the period 7 s.

  8. Progress in Heavy Ion Fusion

    SciTech Connect

    Herrmannsfeldt, W.B.

    1988-09-01

    The progress of the field of Heavy Ion Fusion has been documented in the proceedings of the series of International Symposia that, in recent years, have occurred every second year. The latest of these conferences was hosted by Gesellshaft fuer Schwerionenforshung (GSI) in Darmstadt, West Germany, June 28-30, 1988. For this report, a few highlights from the conference are selected, stressing experimental progress and prospects for future advances. A little extra time is devoted to report on the developments at the Lawrence Berkeley Laboratory (LBL) which is the center for most of the HIFAR program. The Director of the HIFAR program at LBL is Denis Keefe, who presented the HIF report at the last two of the meetings in this series, and in whose place the author is appearing now. 4 refs., 1 fig.

  9. Space Radar Image of Kilauea, Hawaii

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Data acquired on April 13, 1994 and on October 4, 1994 from the X-band Synthetic Aperture Radar on board the space shuttle Endeavour were used to generate interferometric fringes, which were overlaid on the X-SAR image of Kilauea. The volcano is centered in this image at 19.58 degrees north latitude and 155.55 degrees west longitude. The image covers about 9 kilometers by 13 kilometers (5.6 miles by 8 miles). The X-band fringes correspond clearly to the expected topographic image. The yellow line indicates the area below which was used for the three-dimensional image using altitude lines. The yellow rectangular frame fences the area for the final topographic image. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V.(DLR), the major partner in science, operations and data processing of X-SAR. The Instituto Ricerca Elettromagnetismo Componenti Elettronici (IRECE) at the University of Naples was a partner in interferometry analysis.

  10. Space Radar Image of Kilauea Volcano, Hawaii

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This three-dimensional image of the volcano Kilauea was generated based on interferometric fringes derived from two X-band Synthetic Aperture Radar data takes on April 13, 1994 and October 4, 1994. The altitude lines are based on quantitative interpolation of the topographic fringes. The level difference between neighboring altitude lines is 20 meters (66 feet). The ground area covers 12 kilometers by 4 kilometers (7.5 miles by 2.5 miles). The altitude difference in the image is about 500 meters (1,640 feet). The volcano is located around 19.58 degrees north latitude and 155.55 degrees west longitude. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V.(DLR), the major partner in science, operations and data processing of X-SAR. The Instituto Ricerca Elettromagnetismo Componenti Elettronici (IRECE) at the University of Naples was a partner in the interferometry analysis.

  11. Ginkgo biloba extract EGb 761® in children with ADHD.

    PubMed

    Uebel-von Sandersleben, Henrik; Rothenberger, Aribert; Albrecht, Björn; Rothenberger, L Geza; Klement, Stephan; Bock, Nathalie

    2014-09-01

    Fragestellung: Unerwünschte Arzneimittelwirkungen, fehlende Wirksamkeit und Vorurteile gegenüber herkömmlichen medikamentösen Behandlungsformen verlangen nach alternativen medizinischen Behandlungsmöglichkeiten der ADHS. Eine erfolgversprechende, bislang kaum untersuchte Möglichkeit zur Behandlung kognitiver Aspekte ist die Gabe von Ginkgo biloba. Ziel der vorliegenden Studie war die Prüfung klinischer Wirksamkeit und deren Zusammenhang mit hirnelektrischer Aktivität unter der Gabe von Ginkgobiloba-Extrakt EGb 761® bei Kindern mit ADHS vom kombinierten Subtyp nach DSM-IV. Methodik: EGb 761® wurde in einer offenen, klinischen Studie 20 Kindern mit ADHS über 3 bis 5 Wochen verabreicht. Die Dosis wurde bis maximal 240 mg täglich erhöht, solange klinisch relevante Aufmerksamkeitsprobleme bestanden. Klinische Wirksamkeit wurde auf mehreren Ebenen untersucht und beinhaltete klinische Untersuchung, Lebensqualität und Verhaltens- und hirnelektrische Aktivitätsparameter während eines Continuous Performance Tests (Cue-CNV im CPT). Ergebnisse: Im Beobachtungszeitraum traten nur wenige leicht ausgeprägte unerwünschte Wirkungen auf. Nach Gabe von EGb 761® kam es zu möglichen Verbesserung von Lebensqualität, ADHS-Kernsymptomatik und Leistung im CPT. Verbesserungen der Kernsymptomatik waren gleichzeitig mit erhöhter CNV-Amplitude korreliert. Schlussfolgerung: Die Ergebnisse lassen vermuten, dass EGb 761® mit einer Dosis von bis zu 240 mg täglich eine verträgliche und klinisch wirksame alternative Behandlungsmöglichkeit für Kinder mit ADHS darstellt, wenngleich weitere Studien erforderlich sind, um diese vorläufigen Befunde zu stützen.

  12. The Teamwork Assessment Scale: A Novel Instrument to Assess Quality of Undergraduate Medical Students' Teamwork Using the Example of Simulation-based Ward-Rounds.

    PubMed

    Kiesewetter, Jan; Fischer, Martin R

    2015-01-01

    der Skala und klinischer Performanz als einem externen Kriterium (r=,64) gezeigt werden und die ausreichend hohen psychometrischen Eigenschaften konnten repliziert werden (Cronbach’s α=,78).Schlussfolgerungen: Die Validierung gestattet den Einsatz der Teamarbeitsskala in Visitentrainings von Studierenden, um Teamarbeit reliabel von Ärztinnen und Ärzten einschätzen zu lassen. Weitere Studien sind notwendig, um die Anwendbarkeit des Instruments zu verifizieren.

  13. [Standardized impartial assessment of pain in unconscious patients with the Zurich Observation Pain Assessment on a neurosurgical intensive care unit - a case report].

    PubMed

    Maier, Jürgen; Fröhlich, Martin R; Spirig, Rebecca

    2015-02-01

    Hintergrund: Aus internationalen Studien geht hervor, dass ein Großteil der Patienten Aus Gründen der besseren Lesbarkeit wird im Text ausschließlich die männliche Form verwendet. Dies schließt die weibliche Form mit ein., die auf Intensivstationen behandelt werden, moderate bis starke Schmerzen beschreibt. Erwiesen ist auch, dass nicht erkannte und ungenügend therapierte Schmerzen schwere körperliche und seelische Belastungen hervorrufen können. Eines der wichtigsten Therapieziele im Intensivbereich ist deshalb das frühzeitige und sichere Erkennen von Schmerzen, was bei stark bewusstseinsbeeinträchtigten Patienten eine große Herausforderung darstellt. Ziel: Das Ziel dieser Studie ist es, aufzuzeigen, wie mit einer standardisierten Fremdeinschätzung von Schmerzen mit dem Zurich Observation Pain Assessment (ZOPA©) diese Lücke geschlossen werden kann. Methode: Anhand einer theoriegeleiteten interpretativen Fallstudie wird der Einsatz von ZOPA© in der Praxis und dessen Einfluss auf das Schmerzmanagement beschrieben. Ergebnisse: Insgesamt wurden 126 Einzelerfassungen bei einer Intensivpatientin mit einer schweren Subarachnoidalblutung analysiert, wovon 19 Erfassungen auf Schmerz hinweisende Verhaltensmerkmale zeigten. In drei Vierteln dieser Fälle wurden umgehend schmerzlindernde Maßnahmen eingeleitet. Auf der betreffenden Intensivstation wird ZOPA© seit fünf Jahren angewandt, neben der analgetischen Basismedikation sind zusätzliche Analgetika als Bedarfsmedikation verordnet, was Pflegenden den Freiraum lässt, ihre Verantwortung im Schmerzmanagement wahrzunehmen. Schlussfolgerung: Die Fallstudie zeigt, dass sich ZOPA© als geeignetes Fremdeinschätzungsinstrument erweist, anhand dessen Schmerzen frühzeitig erkannt und behandelt bzw. Schmerzsituationen vermieden werden könnten.

  14. Blogging medical students: a qualitative analysis.

    PubMed

    Pinilla, Severin; Weckbach, Ludwig T; Alig, Stefan K; Bauer, Helen; Noerenberg, Daniel; Singer, Katharina; Tiedt, Steffen

    2013-01-01

    Einleitung: Bloggen ist eine unter Medizinstudierenden zunehmend verbreitete Methode, Erfahrungen über das Internet mit einer weltweiten „Learning Community“ auszutauschen. Trotz intensiver Recherche sind den Autoren keine Studien bekannt, in denen spezifisch Blogs von Medizinstudierenden qualitativ analysiert wurden. Im Folgenden werden Kategorien und Themen aus diesen Blogeinträgen beschrieben und ihre medizindidaktische Bedeutung für Medizinstudierende und Lehrende diskutiert.Methoden: In der vorliegenden qualitativen Studie wurden ursprünglich 75 von Medizinstudierenden verfasste Blogs identifiziert. 33 Blogs mit insgesamt 1228 englischen und 337 deutschen Einträgen erfüllten die Einschlusskriterien und wurden analysiert. Mit Hilfe einer komparativen Analysemethode wurden die Blogeinträge zunächst Zeile für Zeile und anschließend fokussiert kodiert. Die emergierenden Themen und Unterthemen wurden in übergeordneten Kategorien zusammengefasst.Ergebnisse: Medizinstudierende verwenden Blogs, um über eine große Vielfalt an Erfahrungen während des Medizinstudiums zu berichten und diese zu reflektieren. Vorbereitung auf schriftliche und mündliche Examina, Erfahrungen während klinischer Praktika, der Umgang mit belastenden Situationen während des Studiums und das Sozialleben jenseits des Studiums waren Hauptthemen.Schlussfolgerung: Unsere Ergebnisse weisen darauf hin, dass Blogs für Medizinstudierende möglicherweise hilfreich sind, um Erfahrungen zu reflektieren. Zusätzlich können Lehrende auf diesem Weg wertvolle Einblicke in die studentische Wahrnehmung der medizinischen Ausbildung erhalten.Die Bedeutung von Blogs in der medizinischen Ausbildung könnte durch gezieltes Kommentieren von Blogeinträgen durch Lehrende erhöht werden. Von diesem Dialog könnte auch eine örtlich unabhängige „Learning Community“ profitieren.

  15. Examination performances of German and international medical students in the preclinical studying-term--a descriptive study.

    PubMed

    Huhn, D; Resch, F; Duelli, R; Möltner, A; Huber, J; Karimian Jazi, K; Amr, A; Eckart, W; Herzog, W; Nikendei, C

    2014-01-01

    Einleitung: Medizinstudierende mit Migrationshintergrund sind im Rahmen ihres Studiums mit zahlreichen spezifischen Problemen konfrontiert. Internationale Studien geben erste Hinweise darauf, dass diese Gruppe von Studierenden schlechtere Leistungen sowohl in schriftlichen als auch in mündlichen oder praktischen Prüfungen erbringt. Für den deutschsprachigen Raum existieren bisher in Hinblick auf diesen thematischen Fokus keinerlei Erkenntnisse.Methode: Für das Jahr 2012 wurde eine deskriptive, retrospektive Analyse der Prüfungsleistungen von Medizinstudierenden des vorklinischen Studienabschnitts an der Medizinischen Fakultät Heidelberg für schriftliche Noten der Semesterabschlussklausuren im zweiten (N=276), dritten (N=292) und vierten Fachsemester (N=285) vorgenommen und für die deutschen Studierenden, die Studierenden aus dem EU-Ausland als auch die Studierenden aus dem nicht-EU-Ausland verglichen. Gleiches geschah mit den mündlichen Noten des ersten Staatsexamens für den Zeitraum 2009 - 2012 (N=1137).Ergebnisse: Deutsche Studierende erzielten in allen Semesterabschlussklausuren sowie in der mündlichen Staatsexamensprüfung signifikant bessere Ergebnisse als Studierende mit einem nicht-EU-staatlichen Migrationshintergrund (alle p<.05). In den Klausuren des dritten und vierten Fachsemesters waren zudem die erbrachten Leistungen der Studierenden mit einem EU-staatlichen Hintergrund signifikant besser als die ihrer außereuropäischen Kommilitonen (p<.05). Außerdem zeigte sich, dass deutsche Studierende zu einem signifikant früheren Zeitpunkt die mündliche Staatsexamensprüfung absolvierten als Studierende mit einem nicht-EU-staatlichen Hintergrund (p<.01).Diskussion: Die Gruppe der nicht-deutschen Medizinstudierenden mit einem Herkunftsland außerhalb der Europäischen Union ist mit schlechteren Prüfungsergebnissen bei zeitgleich längerer Studienzeit als hochrelevante Risikogruppe innerhalb der Studierenden nicht-deutscher Herkunft auszumachen.

  16. German medical students' exposure and attitudes toward pharmaceutical promotion: a cross-sectional survey.

    PubMed

    Jahnke, Kristine; Kremer, Marcel Stephan; Schmidt, Carsten Oliver; Kochen, Michael M; Chenot, Jean-François

    2014-01-01

    Zielsetzung: Internationale Studien belegen, dass Kontakte zu Werbeaktivitäten der pharmazeutischen Industrie früh im Medizinstudium stattfinden. Wir erfassten die Häufigkeit und Orte des Kontaktes von deutschen Medizinstudierenden zu Pharmawerbung und untersuchten ihre Einstellungen zu pharmazeutischen Werbeaktivitäten.Methodik: Die vorliegende Querschnittsstudie basiert auf einem selbst-entwickelten Fragebogen. 1287 Medizinstudierende des klinischen Abschnitts der Universitätsmedizin Göttingen im Jahre 2010 wurden kontaktiert. Die Einstellungen zu verschiedenen Aussagen zu Pharmawerbung wurden mit einer 4-stufigen Rating-Skala erfasst.Ergebnisse: 702 Medizinstudierende (55%) nahmen an der Befragung teil. Der Anteil von Studierenden mit direktem Kontakt zu Pharmareferenten stieg von 21% im ersten klinischen Jahr auf 77% im Praktischen Jahr an. 60% der Befragten wurden während ihrer Famulatur angesprochen. 80% der Studierenden nahmen mindestens einmal ein Werbegeschenk an und 86% gaben an, dass ihr Verschreibungsverhalten durch die Annahme von Werbegeschenken nicht beeinflusst werde. Jedoch nahmen 35% von ihnen an, dass Ärzte beeinflussbar seien. Fast alle (90%) berichteten, dass das Thema Pharmawerbung nicht im Unterricht behandelt wurde. 65% der Studierenden fühlten sich unzureichend auf Interaktionen mit der Pharmaindustrie vorbereitet. 19% der Befragten befürworteten ein Pharmakontaktverbot im Medizinstudium.Schlussfolgerung: Deutsche Medizinstudierende haben früh und häufig Kontakt zur pharmazeutischen Industrie. Das Bewusstsein für daraus resultierende Interessenkonflikte ist gering. Medizinische Fakultäten sollten Regelungen für die Kontakte entwickeln und das Thema in den Unterricht integrieren um Studierende auf Interaktionen mit der Pharmaindustrie vorzubereiten.

  17. Developing and piloting a multifactorial intervention to address participation and quality of life in nursing home residents with joint contractures (JointConImprove): study protocol.

    PubMed

    Müller, Martin; Bartoszek, Gabriele; Beutner, Katrin; Klingshirn, Hanna; Saal, Susanne; Stephan, Anna-Janina; Strobl, Ralf; Grill, Eva; Meyer, Gabriele

    2015-01-01

    Hintergrund: Gelenkkontrakturen sind häufige Probleme gebrechlicher älterer Menschen in Pflegeheimen. Unabhängig von der genauen Anzahl an älteren Menschen, die an Gelenkkontrakturen leiden, scheint dieses Syndrom ein relevantes Problem im Setting Pflegeheim dazustellen. Durch einen zunehmenden Fokus auf Gelenkkontrakturen, z.B. durch die Pflegeversicherung, kam es zu einem Anstieg im Dokumentations- und Assessmentaufwand und in der Einführung von Präventionsmaßnahmen. Viel mehr Aufmerksamkeit sollte aber auf die tatsächliche Situation der älteren Menschen mit Gelenkkontrakturen in Pflegeheimen gelegt werden, vor allem deren tatsächlichen Einschränkungen in Aktivitäten und Teilhabe. Das Ziel dieser Studie ist daher, 1) die Entwicklung einer maßgeschneiderten Intervention zur Verbesserung der Funktionsfähigkeit, sozialen Teilhabe und Lebensqualität von Menschen mit Gelenkkontrakturen in Pflegeheimen und 2) die Überprüfung der Machbarkeit der Intervention, begleitet von einer Prozessevaluation.Methoden: Die Entwicklung der komplexen Intervention folgt dem UK Medical Research Council (MRC) Framework und integriert die Perspektiven aller potenziell relevanten Benutzergruppen von den betroffenen Personen über Kliniker und Forscher. Der Entwicklungsprozess beinhaltet einen systematischen Literaturreview, die Re-Analyse vorhandener Daten, Fokusgruppeninterviews mit Betroffenen, eine Expertentagung und eine Delphi-Studie mit klinischen Experten sowie eine Cluster-randomisierte Pilotstudie mit umfassender Prozessevaluation. Diskussion: Die geplante Studie wird eine maßgeschneiderte Intervention zur Verbesserung von Funktionsfähigkeit, sozialer Teilhabe und Lebensqualität von Menschen mit Gelenkkontrakturen in Pflegeheimen bereitstellen. Die Pilotstudie inklusive der Prozessevaluation stellt einen ersten Schritt zur Schätzung der Stärke des Interventionseffektes dar und wird weitere Studien vorbereiten.

  18. [Coping with everyday stress in different problem areas- comparison of clinically referred and healthy adolescents].

    PubMed

    Escher, Fabian; Seiffge-Krenke, Inge

    2013-09-01

    Fragestellung: In der Untersuchung klinisch auffälliger Jugendlicher fehlen bislang Studien zum Coping mit alltäglichen Stressoren im Vergleich zu gesunden Jugendlichen. Methodik: Klinisch auffällige Jugendliche mit verschiedenen Störungen (gemischten Störungen einschließlich Delinquenz, Sucht, Depression) wurden anhand des Coping across Situations Questionnaire (Seiffge-Krenke, 1995) und einer gekürzten Version des Youth Self Report (Achenbach, 1991) mit gesunden Jugendlichen verglichen. Ergebnisse: Die verschiedenen klinischen Gruppen (n = 469) zeigten spezifische Muster hinsichtlich ihres Copings. Die Gruppe der depressiven Jugendlichen zeigten insgesamt sehr geringe Werte im Coping. Die Gruppe aus den Einrichtungen der Suchthilfe hingegen bediente sich vor allem dysfunktionaler Copingstrategien. Die Jugendlichen aus Einrichtungen der Jugendhilfe (gemischte Störungen einschließlich Delinquenz) hatten sowohl in den dysfunktionalen als auch in den funktionalen Copingstrategien höhere Werte als die beiden anderen klinisch auffälligen Gruppen. Die Kontrollgruppe zeigte mehr funktionales und geringeres dysfunktionales Coping. Die klinisch auffälligen Jugendlichen differenzierten in ihrem Copingverhalten nicht in Abhängigkeit von den unterschiedlichen Problembereichen. Es zeigte sich des Weiteren ein geringer Geschlechtseffekt im Coping. Schlussfolgerungen: Klinisch auffällige Jugendliche waren nicht in der Lage adaptiv auf verschiedene Problembereiche zu reagieren, sondern wandten situationsübergreifend dysfunktionale Copingstrategien wie Rückzug und Problemmeidung an.

  19. The scholar role in the National Competence Based Catalogues of Learning Objectives for Undergraduate Medical Education (NKLM) compared to other international frameworks.

    PubMed

    Hautz, Stefanie C; Hautz, Wolf E; Keller, Niklas; Feufel, Markus A; Spies, Claudia

    2015-01-01

    Hintergrund: In Deutschland haben die Gesellschaft für Medizinische Ausbildung (GMA) und der Medizinische Fakultätentag (MFT) den Nationalen Kompetenzbasierten Lernzielkatalog Medizin (NKLM) federführend entwickelt. Dieser beschreibt, wie viele internationale Pendants, detailliert Qualifikationen für Absolventen des Medizinstudiums. Die Definition derartiger Rahmenwerke folgt der Bestrebung, Ausbildungsinhalte den Lehrenden und Lernenden sowie der Gesellschaft transparent darzustellen. Der NKLM ergänzt die Listen von Themen aus Gegenstandskatalogen durch eine Sammlung erlernbarer Kompetenzen. Alle Rahmenwerke sind dabei entweder in Kapitel oder Domänen oder nach ärztlichen Rollen gegliedert. Dabei wirft die Definition der Gelehrten-Rolle zahlreiche Fragen auf, wie Studien gezeigt haben: Welcher Unterschied besteht zwischen den notwendigen Qualifikationen als wissenschaftlich qualifizierter Arzt und denen als ärztlicher Wissenschaftler? Wie werden die Schwerpunkte gesetzt und wie unterscheiden sie sich im internationalen Vergleich?Methode: In einer systematischen, dreistufigen Recherche wurden 13 internationale Rahmenwerke identifiziert und deren Inhalte durch eine qualitative Textanalyse mit den Inhalten der Gelehrten-Rolle des NKLM verglichen. Die drei Stufen umfassen (1) die systematische Suche, (2) die transparente Auswahl publizierter Rahmenwerke (in- und exclusion) und (3) die Datenextraktion, Kategorisierung und Validierung. Die Ergebnisse daraus wurden mit der Gelehrten-Rolle des NKLM verglichen.Ergebnisse: Die extrahierten Inhalte aller Rahmenwerke lassen sich in die Komponenten Gemeinsame Grundlagen, Klinische Anwendung, Forschung, Lehren und Bilden, sowie Lebenslanges Lernen gliedern. Im Unterschied zu den verglichenen Rahmenwerken betont der NKLM die zum Forschen und Lehren notwendigen Kompetenzen, während die klinische Anwendung eine vergleichsweise untergeordnete Rolle spielt. Schlussfolgerung: Die Inhalte der Gelehrtenrolle des NKLM

  20. The active participation of German-speaking countries in conferences of the Association for Medical Education in Europe (AMEE) between 2005 and 2013: a reflection of the development of medical education research?

    PubMed

    Raes, Patricia; Bauer, Daniel; Schöppe, Franziska; Fischer, Martin R

    2014-01-01

    Zielsetzung: International gewinnt medizinische Ausbildungsforschung an Bedeutung. Seit Anfang der 2000er ist auch in deutschsprachigen Ländern (D-A-CH) ein steigendes Interesse zu beobachten. In einer kontinuierlichen Steigerung der Publikationszahlen deutscher Autoren in internationalen Fachzeitschriften zum Thema „medizinische Ausbildung“ schlug sich das bisher jedoch nicht nieder. Die vorliegende Arbeit untersucht, ob sich jene Entwicklungen aus der aktiven Teilnahme deutschsprachiger Forscher an den Konferenzen der AMEE ablesen lassen.Methoden: Die Tagungsbände der AMEE-Kongresse von 2005-2013 der Kategorien „Postervorträge“, „Short Communications“, „Research Papers“ und „Plenarvorträge“ wurden auf Beteiligung aus D-A-CH hin untersucht. Im Anschluss wurden die Abstracts einer inhaltlichen Analyse unterzogen und nach Studiendesign, Methodik, Untersuchungsgegenstand und Forschungsthema kategorisiert. Ergebnisse: Von 9446 analysierten Abstracts weisen 549 Beiträge mindestens einen Erst-/Co- oder Letztautor aus D-A-CH auf. Die absolute Zahl der Beiträge pro Kongress schwankt zwischen 44 im Jahr 2010 und 77 im Jahr 2013. Der prozentuale Anteil schwankt zwischen 10,0% in 2005 und 4,1% im Jahr 2010. Seit 2010 stieg die Beteiligung jedoch kontinuierlich an. Die Arbeiten sind zumeist deskriptiver Art (62,7%). Studien zu grundlegenden Fragen des Lehrens und Lernens (clarification studies) sind eher selten (4,0%). Angewandt wurden meist quantitative Methoden (51,9%), um Fragestellungen zu Themen wie Lehr- und Lernmethoden (33,0%), Evaluation und Assessment (22,4%) oder Curriculumsentwicklung (14,4%) zu untersuchen. Untersuchungsgegenstand sind meist Studierende (52,5%).Schlussfolgerung: Die Beitragszahlen aus D-A-CH weisen zu Beginn und am Ende des Untersuchungszeitraums ein Maximum auf. Ein kontinuierlicher Anstieg der aktiven Beteiligung seit 2005 ist nicht zu beobachten. Dieser Umstand spiegelt nicht das steigende Interesse an der

  1. Heat for wounds - water-filtered infrared-A (wIRA) for wound healing - a review.

    PubMed

    Hoffmann, Gerd; Hartel, Mark; Mercer, James B

    2016-01-01

    Hintergrund: Wassergefiltertes Infrarot A (wIRA) ist eine spezielle Form der Wärmestrahlung mit hohem Eindringvermögen in das Gewebe und geringer thermischer Belastung der Hautoberfläche. wIRA entspricht dem Großteil der die Erdoberfläche in gemäßigten Klimazonen durch Wasser und Wasserdampf der Atmosphäre gefiltert erreichenden Sonnenwärmestrahlung. wIRA fördert die Heilung akuter und chronischer Wunden sowohl über thermische und temperaturabhängige als auch über nicht-thermische und temperaturunabhängige zelluläre Effekte.Methoden: Diese Publikation schließt eine Literaturübersicht mit Suche in PubMed/Medline nach “water-filtered infrared-A” und “wound”/”ulcus” oder “wassergefiltertes Infrarot A” und “Wunde”/”Ulkus” (Publikationen in Englisch und Deutsch) und zusätzliche Analysen von Studiendaten ein. 7 prospektive klinische Studien (davon 6 randomisierte kontrollierte Studien (RCT), die größte Studie mit n=400 Patienten) wurden gefunden und eingeschlossen. Alle randomisierten kontrollierten klinischen Studien vergleichen eine Kombination aus Therapie auf hohem Niveau plus wIRA-Therapie vs. Therapie auf hohem Niveau allein. Die mit „vs.“ gekennzeichneten Ergebnisse unten zeigen diese Vergleiche. Ergebnisse: wIRA steigert die Temperatur (+2,7°C in 2 cm Gewebetiefe) und den Sauerstoffpartialdruck im Gewebe (+32% in 2 cm Gewebetiefe) und die Gewebedurchblutung (Größe der Effekte innerhalb der wIRA-Gruppe). wIRA fördert sowohl die normale als auch die gestörte Wundheilung, indem es Entzündung und Sekretion mindert, Infektionsabwehr und Regeneration fördert und Schmerzen lindert (bezüglich Schmerzlinderung ausnahmslos während 230 Bestrahlungen, 13.4 vs. 0,0 auf einer visuellen Analogskala (VAS 0–100), mediane Differenz zwischen den Gruppen 13.8, 95%-Konfidenzinterval (KI) 12.3/16.7, p<0,000001) mit relevant weniger Analgetikabedarf (52–69% weniger in den drei Gruppen mit wIRA verglichen mit den drei

  2. Monte Carlo calculated and experimentally determined output correction factors for small field detectors in Leksell Gamma Knife Perfexion beams

    NASA Astrophysics Data System (ADS)

    Benmakhlouf, H.; Johansson, J.; Paddick, I.; Andreo, P.

    2015-05-01

    The measurement of output factors (OF) for the small photon beams generated by Leksell Gamma Knife® (LGK) radiotherapy units is a challenge for the physicist due to the under or over estimation of these factors by a vast majority of the detectors commercially available. Output correction factors, introduced in the international formalism published by Alfonso (2008 Med. Phys. 35 5179-86), standardize the determination of OFs for small photon beams by correcting detector-reading ratios to yield OFs in terms of absorbed-dose ratios. In this work output correction factors for a number of detectors have been determined for LGK Perfexion™ 60Co γ-ray beams by Monte Carlo (MC) calculations and measurements. The calculations were made with the MC system PENELOPE, scoring the energy deposited in the active volume of the detectors and in a small volume of water; the detectors simulated were two silicon diodes, one liquid ionization chamber (LIC), alanine and TLD. The calculated LIC output correction factors were within ± 0.4%, and this was selected as the reference detector for experimental determinations where output correction factors for twelve detectors were measured, normalizing their readings to those of the LIC. The MC-calculated and measured output correction factors for silicon diodes yielded corrections of up to 5% for the smallest LGK collimator size of 4 mm diameter. The air ionization chamber measurements led to extremely large output correction factors, caused by the well-known effect of partial volume averaging. The corrections were up to 7% for the natural diamond detector in the 4 mm collimator, also due to partial volume averaging, and decreased to within about ± 0.6% for the smaller synthetic diamond detector. The LIC, showing the smallest corrections, was used to investigate machine-to-machine output factor differences by performing measurements in four LGK units with different dose rates. These resulted in OFs within ± 0.6% and ± 0

  3. Discovery and partial characterization of a non-LTR retrotransposon that may be associated with abdominal segment deformity disease (ASDD) in the whiteleg shrimp Penaeus (Litopenaeus) vannamei

    PubMed Central

    2013-01-01

    Background Abdominal segment deformity disease (ASDD) of cultivated whiteleg shrimp Penaeus (Litopenaeus) vannamei causes economic loss of approximately 10% in affected specimens because of the unsightliness of distorted abdominal muscles. It is associated with the presence of viral-like particles seen by electron microscopy in the ventral nerve cords of affected shrimp. Thus, shotgun cloning was carried out to seek viral-like sequences in affected shrimp. Results A new retrovirus-like element of 5052 bp (named abdominal segment deformity element or ASDE) was compiled by shotgun cloning and 3′ and 5′ RACE using RNA and DNA extracted from ventral nerve cords of ASDD shrimp. ASDE contained 7 putative open reading frames (ORF). One ORF (called the PENS sub-domain), had a deduced amino acid (aa) sequence homologous to the GIY-YIG endonuclease domain of penelope-like retrotransposons while two others were homologous to the reverse transcriptase (RT) and RNaseH domains of the pol gene of non-long terminal repeat (non-LTR) retrotransposons (called the NLRS sub-domain). No single amplicon of 5 kb containing both these elements was obtained by PCR or RT-PCR from ASDD shrimp. Subsequent analysis indicated that PENS and NLRS were not contiguous and that NLRS was a host genetic element. In situ hybridization using a dioxygenin-labeled NLRS probe revealed that NLRS gave positive reactions in abdominal-ganglion neurons of ASDD shrimp but not normal shrimp. Preliminary analysis indicated that long-term use of female broodstock after eyestalk ablation in the hatchery increased the intensity of RT-PCR amplicons for NLRS and also the prevalence of ASDD in mysis 3 offspring of the broodstock. The deformities persist upon further cultivation until shrimp harvest but do not increase in prevalence and do not affect growth or survival. Conclusions Our results suggested that NLRS is a shrimp genetic element associated with ASDD and that immediate preventative measures could include

  4. A deterministic partial differential equation model for dose calculation in electron radiotherapy

    NASA Astrophysics Data System (ADS)

    Duclous, R.; Dubroca, B.; Frank, M.

    2010-07-01

    High-energy ionizing radiation is a prominent modality for the treatment of many cancers. The approaches to electron dose calculation can be categorized into semi-empirical models (e.g. Fermi-Eyges, convolution-superposition) and probabilistic methods (e.g. Monte Carlo). A third approach to dose calculation has only recently attracted attention in the medical physics community. This approach is based on the deterministic kinetic equations of radiative transfer. We derive a macroscopic partial differential equation model for electron transport in tissue. This model involves an angular closure in the phase space. It is exact for the free streaming and the isotropic regime. We solve it numerically by a newly developed HLLC scheme based on Berthon et al (2007 J. Sci. Comput. 31 347-89) that exactly preserves the key properties of the analytical solution on the discrete level. We discuss several test cases taken from the medical physics literature. A test case with an academic Henyey-Greenstein scattering kernel is considered. We compare our model to a benchmark discrete ordinate solution. A simplified model of electron interactions with tissue is employed to compute the dose of an electron beam in a water phantom, and a case of irradiation of the vertebral column. Here our model is compared to the PENELOPE Monte Carlo code. In the academic example, the fluences computed with the new model and a benchmark result differ by less than 1%. The depths at half maximum differ by less than 0.6%. In the two comparisons with Monte Carlo, our model gives qualitatively reasonable dose distributions. Due to the crude interaction model, these so far do not have the accuracy needed in clinical practice. However, the new model has a computational cost that is less than one-tenth of the cost of a Monte Carlo simulation. In addition, simulations can be set up in a similar way as a Monte Carlo simulation. If more detailed effects such as coupled electron-photon transport, bremsstrahlung

  5. High energy photon reference for radiation protection: technical design of the LINAC beam and ionization chambers; and calculation of monoenergetic conversion coefficients

    NASA Astrophysics Data System (ADS)

    Dusciac, D.; Bordy, J.-M.; Daures, J.; Blideanu, V.

    2016-09-01

    In this work, we present the results of the first part of a research project aimed at offering a complete response to dosimeters providers and nuclear physicists' demands for high-energy (6 - 9 MeV) photon beams for radiation protection purposes. Classical facilities allowing the production of high-energy photonic radiation (proton accelerators, nuclear reactors) are very rare and need large investment for development and use. A novel solution is proposed, consisting in the use of a medical linear accelerator, allowing a significant decrease of all costs.Using Monte Carlo simulations (MCNP5 and PENELOPE codes), a specifically designed electron-photon conversion target allowing for obtaining a high energy photon beam (with an average energy weighted by fluence of about 6 MeV) has been built for radiation protection purposes. Due to the specific design of the target, this "realistic" radiation protection high-energy photon beam presents a uniform distribution of air kerma rate at a distance of 1 m, over a 30 × 30 cm2 surface. Two graphite cavity ionizing chambers for ionometric measurements have been built. For one of these chambers, the charge collection volume has been measured allowing for its use as a primary standard. The second ionizing chamber is used as a transfer standard; as such it has been calibrated in a 60Co beam, and in the high energy photon beam for radiation protection.The measurements with these ionizing chambers allowed for an evaluation of the air kerma rate in the LINAC based high-energy photon beam for radiation protection: the values cover a range between 36 mGy/h and 210 mGy/h, compatible with radiation protection purposes.Finally, using Monte Carlo simulations, conversion coefficients from air kerma to dose equivalent quantities have been calculated in the range between 10 keV and 22.4 MeV, for the spectral distribution of the fluence corresponding to the beam produced by the linear accelerator of the LNE-LNHB.

  6. Monte Carlo dose enhancement studies in microbeam radiation therapy

    SciTech Connect

    Martinez-Rovira, I.; Prezado, Y.

    2011-07-15

    Purpose: A radical radiation therapy treatment for gliomas requires extremely high absorbed doses resulting in subsequent deleterious side effects in healthy tissue. Microbeam radiation therapy (MRT) is an innovative technique based on the fact that normal tissue can withstand high radiation doses in small volumes without any significant damage. The synchrotron-generated x-ray beam is collimated and delivered to an array of narrow micrometer-sized planar rectangular fields. Several preclinical experiments performed at the Brookhaven National Laboratory (BNL) and at the European Synchrotron Radiation Facility (ESRF) confirmed that MRT yields a higher therapeutic index than nonsegmented beams of the same characteristics. This index can be greatly improved by loading the tumor with high atomic number (Z) contrast agents. The aim of this work is to find the high-Z element that provides optimum dose enhancement. Methods: Monte Carlo simulations (PENELOPE/penEasy) were performed to assess the peak and valley doses as well as their ratio (PVDR) in healthy tissue and in the tumor, loaded with different contrast agents. The optimization criteria used were maximization of the ratio between the PVDR values in healthy tissue respect to the PVDR in the tumor and minimization of bone and brain valley doses. Results: Dose enhancement factors, PVDR, and valley doses were calculated for different high-Z elements. A significant decrease of PVDR values in the tumor, accompanied by a gain in the valley doses, was found in the presence of high-Z elements. This enables the deposited dose in the healthy tissue to be reduced. The optimum high-Z element depends on the irradiation configuration. As a general trend, the best outcome is provided by the highest Z contrast agents considered, i.e., gold and thallium. However, lanthanides (especially Lu) and hafnium also offer a satisfactory performance. Conclusions: The remarkable therapeutic index in microbeam radiation therapy can be further

  7. MO-F-CAMPUS-J-04: Radiation Heat Load On the MR System of the Elekta Atlantic System

    SciTech Connect

    Towe, S; Roberts, D; Overweg, J; Van Lanen, E

    2015-06-15

    Purpose: The Elekta Atlantic system combines a digital linear accelerator system with a 1.5T Philips MRI machine.This study aimed to assess the energy deposited within the cryostat system when the radiation beam passes through the cryostat. The cryocooler on the magnet has a cooling capacity which is about 1 Watt in excess of the cryogenic heat leak into the magnet’s cold mass. A pressure-controlled heater inside the magnet balances the excess refrigeration power such that the helium pressure in the tank is kept slightly above ambient air pressure. If radiation power is deposited in the cold mass then this heater will need less power to maintain pressure equilibrium and if the radiation heat load exceeds the excess cryocooler capacity the pressure will rise. Methods: An in-house CAD based Monte Carlo code based on Penelope was used to model the entire MR-Linac system to quantify the heat load on the magnet’s cold mass. These results were then compared to experimental results obtained from an Elekta Atlantic system installed in UMC-Utrecht. Results: For a field size of 25 cm x 22 cm and a dose rate of 107 mu.min-1, the energy deposited by the radiation beam led to a reduction in heater power from 1.16 to 0.73 W. Simulations predicted a reduction to 0.69 W which is in good agreement. For the worst case field size (largest) and maximum dose rate the cryostat cooler capacity was exceeded. This resulted in a pressure rise within the system but was such that continuous irradiation for over 12 hours would be required before the magnet would start blowing off helium. Conclusion: The study concluded that the Atlantic system does not have to be duty cycle restricted, even for the worst case non-clinical scenario and that there are no adverse effects on the MR system. Stephen Towe and David Roberts Both work for Elekta; Ezra Van Lanen works for Philips Healthcare; Johan Overweg works for Philips Innovative Technologies.

  8. Dose response of selected solid state detectors in applied homogeneous transverse and longitudinal magnetic fields

    SciTech Connect

    Reynolds, M.; Fallone, B. G.; Rathee, S.

    2014-09-15

    Purpose: MR-Linac devices under development worldwide will require standard calibration, commissioning, and quality assurance. Solid state radiation detectors are often used for dose profiles and percent depth dose measurements. The dose response of selected solid state detectors is therefore evaluated in varying transverse and longitudinal magnetic fields for this purpose. Methods: The Monte Carlo code PENELOPE was used to model irradiation of a PTW 60003 diamond detector and IBA PFD diode detector in the presence of a magnetic field. The field itself was varied in strength, and oriented both transversely and longitudinally with respect to the incident photon beam. The long axis of the detectors was oriented either parallel or perpendicular to the photon beam. The dose to the active volume of each detector in air was scored, and its ratio to dose with zero magnetic field strength was determined as the “dose response” in magnetic field. Measurements at low fields for both detectors in transverse magnetic fields were taken to evaluate the accuracy of the simulations. Additional simulations were performed in a water phantom to obtain few representative points for beam profile and percent depth dose measurements. Results: Simulations show significant dose response as a function of magnetic field in transverse field geometries. This response can be near 20% at 1.5 T, and it is highly dependent on the detectors’ relative orientation to the magnetic field, the energy of the photon beam, and detector composition. Measurements at low transverse magnetic fields verify the simulations for both detectors in their relative orientations to radiation beam. Longitudinal magnetic fields, in contrast, show little dose response, rising slowly with magnetic field, and reaching 0.5%–1% at 1.5 T regardless of detector orientation. Water tank and in air simulation results were the same within simulation uncertainty where lateral electronic equilibrium is present and expectedly

  9. Migration of waterfowl in the east asian flyway and spatial relationship to HPAI H5N1 outbreaks

    USGS Publications Warehouse

    Takekawa, J.Y.; Newman, S.H.; Xiao, X.; Prosser, D.J.; Spragens, K.A.; Palm, E.C.; Yan, B.; Li, T.; Lei, F.; Zhao, D.; Douglas, D.C.; Muzaffar, S.B.; Ji, W.

    2010-01-01

    Poyang Lake is situated within the East Asian Flyway, a migratory corridor for waterfowl that also encompasses Guangdong Province, China, the epicenter of highly pathogenic avian influenza (HPAI) H5N1. The lake is the largest freshwater body in China and a significant congregation site for waterfowl; however, surrounding rice fields and poultry grazing have created an overlap with wild waterbirds, a situation conducive to avian influenza transmission. Reports of HPAI H5N1 in healthy wild ducks at Poyang Lake have raised concerns about the potential of resilient free-ranging birds to disseminate the virus. Yet the role wild ducks play in connecting regions of HPAI H5N1 outbreak in Asia is hindered by a lack of information about their migratory ecology. During 2007-08 we marked wild ducks at Poyang Lake with satellite transmitters to examine the location and timing of spring migration and identify any spatiotemporal relationship with HPAI H5N1 outbreaks. Species included the Eurasian wigeon (Anas penelope), northern pintail (Anas acuta), common teal (Anas crecca), falcated teal (Anas falcata), Baikal teal (Anas formosa), mallard (Anas platyrhynchos), garganey (Anas querquedula), and Chinese spotbill (Anas poecilohyncha). These wild ducks (excluding the resident mallard and Chinese spotbill ducks) followed the East Asian Flyway along the coast to breeding areas in northern China, eastern Mongolia, and eastern Russia. None migrated west toward Qinghai Lake (site of the largest wild bird epizootic), thus failing to demonstrate any migratory connection to the Central Asian Flyway. A newly developed Brownian bridge spatial analysis indicated that HPAI H5N1 outbreaks reported in the flyway were related to latitude and poultry density but not to the core migration corridor or to wetland habitats. Also, we found a temporal mismatch between timing of outbreaks and wild duck movements. These analyses depend on complete or representative reporting of outbreaks, but by

  10. Monte Carlo-based simulation of dynamic jaws tomotherapy

    SciTech Connect

    Sterpin, E.; Chen, Y.; Chen, Q.; Lu, W.; Mackie, T. R.; Vynckier, S.

    2011-09-15

    Purpose: Original TomoTherapy systems may involve a trade-off between conformity and treatment speed, the user being limited to three slice widths (1.0, 2.5, and 5.0 cm). This could be overcome by allowing the jaws to define arbitrary fields, including very small slice widths (<1 cm), which are challenging for a beam model. The aim of this work was to incorporate the dynamic jaws feature into a Monte Carlo (MC) model called TomoPen, based on the MC code PENELOPE, previously validated for the original TomoTherapy system. Methods: To keep the general structure of TomoPen and its efficiency, the simulation strategy introduces several techniques: (1) weight modifiers to account for any jaw settings using only the 5 cm phase-space file; (2) a simplified MC based model called FastStatic to compute the modifiers faster than pure MC; (3) actual simulation of dynamic jaws. Weight modifiers computed with both FastStatic and pure MC were compared. Dynamic jaws simulations were compared with the convolution/superposition (C/S) of TomoTherapy in the ''cheese'' phantom for a plan with two targets longitudinally separated by a gap of 3 cm. Optimization was performed in two modes: asymmetric jaws-constant couch speed (''running start stop,'' RSS) and symmetric jaws-variable couch speed (''symmetric running start stop,'' SRSS). Measurements with EDR2 films were also performed for RSS for the formal validation of TomoPen with dynamic jaws. Results: Weight modifiers computed with FastStatic were equivalent to pure MC within statistical uncertainties (0.5% for three standard deviations). Excellent agreement was achieved between TomoPen and C/S for both asymmetric jaw opening/constant couch speed and symmetric jaw opening/variable couch speed, with deviations well within 2%/2 mm. For RSS procedure, agreement between C/S and measurements was within 2%/2 mm for 95% of the points and 3%/3 mm for 98% of the points, where dose is greater than 30% of the prescription dose (gamma analysis

  11. A GPU OpenCL based cross-platform Monte Carlo dose calculation engine (goMC).

    PubMed

    Tian, Zhen; Shi, Feng; Folkerts, Michael; Qin, Nan; Jiang, Steve B; Jia, Xun

    2015-10-07

    Monte Carlo (MC) simulation has been recognized as the most accurate dose calculation method for radiotherapy. However, the extremely long computation time impedes its clinical application. Recently, a lot of effort has been made to realize fast MC dose calculation on graphic processing units (GPUs). However, most of the GPU-based MC dose engines have been developed under NVidia's CUDA environment. This limits the code portability to other platforms, hindering the introduction of GPU-based MC simulations to clinical practice. The objective of this paper is to develop a GPU OpenCL based cross-platform MC dose engine named goMC with coupled photon-electron simulation for external photon and electron radiotherapy in the MeV energy range. Compared to our previously developed GPU-based MC code named gDPM (Jia et al 2012 Phys. Med. Biol. 57 7783-97), goMC has two major differences. First, it was developed under the OpenCL environment for high code portability and hence could be run not only on different GPU cards but also on CPU platforms. Second, we adopted the electron transport model used in EGSnrc MC package and PENELOPE's random hinge method in our new dose engine, instead of the dose planning method employed in gDPM. Dose distributions were calculated for a 15 MeV electron beam and a 6 MV photon beam in a homogenous water phantom, a water-bone-lung-water slab phantom and a half-slab phantom. Satisfactory agreement between the two MC dose engines goMC and gDPM was observed in all cases. The average dose differences in the regions that received a dose higher than 10% of the maximum dose were 0.48-0.53% for the electron beam cases and 0.15-0.17% for the photon beam cases. In terms of efficiency, goMC was ~4-16% slower than gDPM when running on the same NVidia TITAN card for all the cases we tested, due to both the different electron transport models and the different development environments. The code portability of our new dose engine goMC was validated by

  12. Comparison of dose calculation algorithms in phantoms with lung equivalent heterogeneities under conditions of lateral electronic disequilibrium.

    PubMed

    Carrasco, P; Jornet, N; Duch, M A; Weber, L; Ginjaume, M; Eudaldo, T; Jurado, D; Ruiz, A; Ribas, M

    2004-10-01

    An extensive set of benchmark measurement of PDDs and beam profiles was performed in a heterogeneous layer phantom, including a lung equivalent heterogeneity, by means of several detectors and compared against the predicted dose values by different calculation algorithms in two treatment planning systems. PDDs were measured with TLDs, plane parallel and cylindrical ionization chambers and beam profiles with films. Additionally, Monte Carlo simulations by means of the PENELOPE code were performed. Four different field sizes (10 x 10, 5 x 5, 2 x 2, and 1 x 1 cm2) and two lung equivalent materials (CIRS, p(w)e=0.195 and St. Bartholomew Hospital, London, p(w)e=0.244-0.322) were studied. The performance of four correction-based algorithms and one based on convolution-superposition was analyzed. The correction-based algorithms were the Batho, the Modified Batho, and the Equivalent TAR implemented in the Cadplan (Varian) treatment planning system and the TMS Pencil Beam from the Helax-TMS (Nucletron) treatment planning system. The convolution-superposition algorithm was the Collapsed Cone implemented in the Helax-TMS. The only studied calculation methods that correlated successfully with the measured values with a 2% average inside all media were the Collapsed Cone and the Monte Carlo simulation. The biggest difference between the predicted and the delivered dose in the beam axis was found for the EqTAR algorithm inside the CIRS lung equivalent material in a 2 x 2 cm2 18 MV x-ray beam. In these conditions, average and maximum difference against the TLD measurements were 32% and 39%, respectively. In the water equivalent part of the phantom every algorithm correctly predicted the dose (within 2%) everywhere except very close to the interfaces where differences up to 24% were found for 2 x 2 cm2 18 MV photon beams. Consistent values were found between the reference detector (ionization chamber in water and TLD in lung) and Monte Carlo simulations, yielding minimal

  13. Comparison of dose calculation algorithms in slab phantoms with cortical bone equivalent heterogeneities.

    PubMed

    Carrasco, P; Jornet, N; Duch, M A; Panettieri, V; Weber, L; Eudaldo, T; Ginjaume, M; Ribas, M

    2007-08-01

    To evaluate the dose values predicted by several calculation algorithms in two treatment planning systems, Monte Carlo (MC) simulations and measurements by means of various detectors were performed in heterogeneous layer phantoms with water- and bone-equivalent materials. Percentage depth doses (PDDs) were measured with thermoluminescent dosimeters (TLDs), metal-oxide semiconductor field-effect transistors (MOSFETs), plane parallel and cylindrical ionization chambers, and beam profiles with films. The MC code used for the simulations was the PENELOPE code. Three different field sizes (10 x 10, 5 x 5, and 2 x 2 cm2) were studied in two phantom configurations and a bone equivalent material. These two phantom configurations contained heterogeneities of 5 and 2 cm of bone, respectively. We analyzed the performance of four correction-based algorithms and one based on convolution superposition. The correction-based algorithms were the Batho, the Modified Batho, the Equivalent TAR implemented in the Cadplan (Varian) treatment planning system (TPS), and the Helax-TMS Pencil Beam from the Helax-TMS (Nucletron) TPS. The convolution-superposition algorithm was the Collapsed Cone implemented in the Helax-TMS. All the correction-based calculation algorithms underestimated the dose inside the bone-equivalent material for 18 MV compared to MC simulations. The maximum underestimation, in terms of root-mean-square (RMS), was about 15% for the Helax-TMS Pencil Beam (Helax-TMS PB) for a 2 x 2 cm2 field inside the bone-equivalent material. In contrast, the Collapsed Cone algorithm yielded values around 3%. A more complex behavior was found for 6 MV where the Collapsed Cone performed less well, overestimating the dose inside the heterogeneity in 3%-5%. The rebuildup in the interface bone-water and the penumbra shrinking in high-density media were not predicted by any of the calculation algorithms except the Collapsed Cone, and only the MC simulations matched the experimental values

  14. On the suitability of ultrathin detectors for absorbed dose assessment in the presence of high-density heterogeneities

    SciTech Connect

    Bueno, M. Duch, M. A.; Carrasco, P.; Jornet, N.; Muñoz-Montplet, C.

    2014-08-15

    Purpose: The aim of this study was to evaluate the suitability of several detectors for the determination of absorbed dose in bone. Methods: Three types of ultrathin LiF-based thermoluminescent dosimeters (TLDs)—two LiF:Mg,Cu,P-based (MCP-Ns and TLD-2000F) and a{sup 7}Li-enriched LiF:Mg,Ti-based (MTS-7s)—as well as EBT2 Gafchromic films were used to measure percentage depth-dose distributions (PDDs) in a water-equivalent phantom with a bone-equivalent heterogeneity for 6 and 18 MV and a set of field sizes ranging from 5×5 cm{sup 2} to 20×20 cm{sup 2}. MCP-Ns, TLD-2000F, MTS-7s, and EBT2 have active layers of 50, 20, 50, and 30 μm, respectively. Monte Carlo (MC) dose calculations (PENELOPE code) were used as the reference and helped to understand the experimental results and to evaluate the potential perturbation of the fluence in bone caused by the presence of the detectors. The energy dependence and linearity of the TLDs’ response was evaluated. Results: TLDs exhibited flat energy responses (within 2.5%) and linearity with dose (within 1.1%) within the range of interest for the selected beams. The results revealed that all considered detectors perturb the electron fluence with respect to the energy inside the bone-equivalent material. MCP-Ns and MTS-7s underestimated the absorbed dose in bone by 4%–5%. EBT2 exhibited comparable accuracy to MTS-7s and MCP-Ns. TLD-2000F was able to determine the dose within 2% accuracy. No dependence on the beam energy or field size was observed. The MC calculations showed that a50 μm thick detector can provide reliable dose estimations in bone regardless of whether it is made of LiF, water or EBT’s active layer material. Conclusions: TLD-2000F was found to be suitable for providing reliable absorbed dose measurements in the presence of bone for high-energy x-ray beams.

  15. Comparison of dose calculation algorithms in slab phantoms with cortical bone equivalent heterogeneities

    SciTech Connect

    Carrasco, P.; Jornet, N.; Duch, M. A.; Panettieri, V.; Weber, L.; Eudaldo, T.; Ginjaume, M.; Ribas, M.

    2007-08-15

    To evaluate the dose values predicted by several calculation algorithms in two treatment planning systems, Monte Carlo (MC) simulations and measurements by means of various detectors were performed in heterogeneous layer phantoms with water- and bone-equivalent materials. Percentage depth doses (PDDs) were measured with thermoluminescent dosimeters (TLDs), metal-oxide semiconductor field-effect transistors (MOSFETs), plane parallel and cylindrical ionization chambers, and beam profiles with films. The MC code used for the simulations was the PENELOPE code. Three different field sizes (10x10, 5x5, and 2x2 cm{sup 2}) were studied in two phantom configurations and a bone equivalent material. These two phantom configurations contained heterogeneities of 5 and 2 cm of bone, respectively. We analyzed the performance of four correction-based algorithms and one based on convolution superposition. The correction-based algorithms were the Batho, the Modified Batho, the Equivalent TAR implemented in the Cadplan (Varian) treatment planning system (TPS), and the Helax-TMS Pencil Beam from the Helax-TMS (Nucletron) TPS. The convolution-superposition algorithm was the Collapsed Cone implemented in the Helax-TMS. All the correction-based calculation algorithms underestimated the dose inside the bone-equivalent material for 18 MV compared to MC simulations. The maximum underestimation, in terms of root-mean-square (RMS), was about 15% for the Helax-TMS Pencil Beam (Helax-TMS PB) for a 2x2 cm{sup 2} field inside the bone-equivalent material. In contrast, the Collapsed Cone algorithm yielded values around 3%. A more complex behavior was found for 6 MV where the Collapsed Cone performed less well, overestimating the dose inside the heterogeneity in 3%-5%. The rebuildup in the interface bone-water and the penumbra shrinking in high-density media were not predicted by any of the calculation algorithms except the Collapsed Cone, and only the MC simulations matched the experimental values

  16. Dosimetric evaluation of new approaches in GRID therapy using nonconventional radiation sources

    SciTech Connect

    Martínez-Rovira, I. Prezado, Y.; Fois, G.

    2015-02-15

    Purpose: Spatial fractionation of the dose has proven to be a promising approach to increase the tolerance of healthy tissue, which is the main limitation of radiotherapy. A good example of that is GRID therapy, which has been successfully used in the management of large tumors with low toxicity. The aim of this work is to explore new avenues using nonconventional sources: GRID therapy by using kilovoltage (synchrotron) x-rays, the use of very high-energy electrons, and proton GRID therapy. They share in common the use of the smallest possible grid sizes in order to exploit the dose–volume effects. Methods: Monte Carlo simulations (PENELOPE/PENEASY and GEANT4/GATE codes) were used as a method to study dose distributions resulting from irradiations in different configurations of the three proposed techniques. As figure of merit, percentage (peak and valley) depth dose curves, penumbras, and central peak-to-valley dose ratios (PVDR) were evaluated. As shown in previous biological experiments, high PVDR values are requested for healthy tissue sparing. A superior tumor control may benefit from a lower PVDR. Results: High PVDR values were obtained in the healthy tissue for the three cases studied. When low energy photons are used, the treatment of deep-seated tumors can still be performed with submillimetric grid sizes. Superior PVDR values were reached with the other two approaches in the first centimeters along the beam path. The use of protons has the advantage of delivering a uniform dose distribution in the tumor, while healthy tissue benefits from the spatial fractionation of the dose. In the three evaluated techniques, there is a net reduction in penumbra with respect to radiosurgery. Conclusions: The high PVDR values in the healthy tissue and the use of small grid sizes in the three presented approaches might constitute a promising alternative to treat tumors with such spatially fractionated radiotherapy techniques. The dosimetric results presented here

  17. Targeting mitochondria in cancer cells using gold nanoparticle-enhanced radiotherapy: A Monte Carlo study

    SciTech Connect

    Kirkby, Charles Ghasroddashti, Esmaeel

    2015-02-15

    Purpose: Radiation damage to mitochondria has been shown to alter cellular processes and even lead to apoptosis. Gold nanoparticles (AuNPs) may be used to enhance these effects in scenarios where they collect on the outer membranes of mitochondria. A Monte Carlo (MC) approach is used to estimate mitochondrial dose enhancement under a variety of conditions. Methods: The PENELOPE MC code was used to generate dose distributions resulting from photons striking a 13 nm diameter AuNP with various thicknesses of water-equivalent coatings. Similar dose distributions were generated with the AuNP replaced by water so as to estimate the gain in dose on a microscopic scale due to the presence of AuNPs within an irradiated volume. Models of mitochondria with AuNPs affixed to their outer membrane were then generated—considering variation in mitochondrial size and shape, number of affixed AuNPs, and AuNP coating thickness—and exposed (in a dose calculation sense) to source spectra ranging from 6 MV to 90 kVp. Subsequently dose enhancement ratios (DERs), or the dose with the AuNPs present to that for no AuNPs, for the entire mitochondrion and its components were tallied under these scenarios. Results: For a representative case of a 1000 nm diameter mitochondrion affixed with 565 AuNPs, each with a 13 nm thick coating, the mean DER over the whole organelle ranged from roughly 1.1 to 1.6 for the kilovoltage sources, but was generally less than 1.01 for the megavoltage sources. The outer membrane DERs remained less than 1.01 for the megavoltage sources, but rose to 2.3 for 90 kVp. The voxel maximum DER values were as high as 8.2 for the 90 kVp source and increased further when the particles clustered together. The DER exhibited dependence on the mitochondrion dimensions, number of AuNPs, and the AuNP coating thickness. Conclusions: Substantial dose enhancement directly to the mitochondria can be achieved under the conditions modeled. If the mitochondrion dose can be directly

  18. A dose point kernel database using GATE Monte Carlo simulation toolkit for nuclear medicine applications: Comparison with other Monte Carlo codes

    SciTech Connect

    Papadimitroulas, Panagiotis; Loudos, George; Nikiforidis, George C.; Kagadis, George C.

    2012-08-15

    Purpose: GATE is a Monte Carlo simulation toolkit based on the Geant4 package, widely used for many medical physics applications, including SPECT and PET image simulation and more recently CT image simulation and patient dosimetry. The purpose of the current study was to calculate dose point kernels (DPKs) using GATE, compare them against reference data, and finally produce a complete dataset of the total DPKs for the most commonly used radionuclides in nuclear medicine. Methods: Patient-specific absorbed dose calculations can be carried out using Monte Carlo simulations. The latest version of GATE extends its applications to Radiotherapy and Dosimetry. Comparison of the proposed method for the generation of DPKs was performed for (a) monoenergetic electron sources, with energies ranging from 10 keV to 10 MeV, (b) beta emitting isotopes, e.g., {sup 177}Lu, {sup 90}Y, and {sup 32}P, and (c) gamma emitting isotopes, e.g., {sup 111}In, {sup 131}I, {sup 125}I, and {sup 99m}Tc. Point isotropic sources were simulated at the center of a sphere phantom, and the absorbed dose was stored in concentric spherical shells around the source. Evaluation was performed with already published studies for different Monte Carlo codes namely MCNP, EGS, FLUKA, ETRAN, GEPTS, and PENELOPE. A complete dataset of total DPKs was generated for water (equivalent to soft tissue), bone, and lung. This dataset takes into account all the major components of radiation interactions for the selected isotopes, including the absorbed dose from emitted electrons, photons, and all secondary particles generated from the electromagnetic interactions. Results: GATE comparison provided reliable results in all cases (monoenergetic electrons, beta emitting isotopes, and photon emitting isotopes). The observed differences between GATE and other codes are less than 10% and comparable to the discrepancies observed among other packages. The produced DPKs are in very good agreement with the already published data

  19. Simulating the transport of heavy charged particles through trabecular spongiosa

    NASA Astrophysics Data System (ADS)

    Gersh, Jacob A.

    As planning continues for manned missions far beyond Low Earth Orbit, a paramount concern remains the flight crew's exposure to galactic cosmic radiation. When humans exit the protective magnetic field of Earth, they become subject to bombardment by highly-reactive heavy charged (HZE) particles. A possible consequence of this two- to three-year-long mission is the onset of radiation-induced leukemia, a disorder with a latency period as short as two to three years. Because data on risk to humans from exposure to HZE particles is non-existent, studies of leukemia in animals are now underway to investigate the relative effectiveness of HZE exposures. Leukemogenesis can result from energy depositions occurring within marrow contained in the trabecular spongiosa. Trabecular spongiosa is found in flat bones and within the ends of long bones, and is characterized by an intricate matrix of interconnected bone tissue forming cavities that house marrow. The microscopic internal dimensions of spongiosa vary between species. As radiation traverses this region, interface-induced dose perturbations that occur at the interfaces between bone and marrow affect the patterns of energy deposition within the region. An aim of this project is to determine the extent by which tissue heterogeneity and microscopic dimensions have on patterns of energy deposition within the trabecular spongiosa. This leads to the development of PATHFIT, a computer code capable of generating simple quadric-based geometric models of trabecular spongiosa for both humans and mice based on actual experimentally-determined internal dimensions of trabecular spongiosa. Following the creation of spongiosa models, focus is placed on the development of HITSPAP, a hybrid Monte Carlo (MC) radiation transport code system that combines capabilities of the MC code PENELOPE and MC code PARTRAC. This code is capable of simulating the transport of HZE particles through accurate models of trabecular spongiosa. The final and

  20. A comparison between track-structure, condensed-history Monte Carlo simulations and MIRD cellular S-values.

    PubMed

    Tajik-Mansoury, M A; Rajabi, H; Mozdarani, H

    2017-03-07

    The S-value is a standard measure in cellular dosimetry. S-values are calculated by applying analytical methods or by Monte Carlo simulation. In Monte Carlo simulation, particles are either tracked individually event-by-event or close events are condensed and processed collectively in different steps. Both of these methods have been employed for estimation of cellular S-values, but there is no consistency between the published results. In the present paper, we used the Geant4-DNA track-structure physics model as the reference to estimate the cellular S-values. We compared the results with the corresponding values obtained from the following three condensed-history physics models of Geant4: Penelope, Livermore and standard. The geometry and source were exactly the same in all the simulations. We utilized mono-energetic electrons with an initial kinetic energy in the range 1-700 keV as the source of radiation. We also compared our results with the MIRD S-values. We first drew an overall comparison between different data series and then compared the dependence of results on the energy of particles and the size of scoring compartments. The overall comparison indicated a very good linear correlation (R (2)  >  91%) and small bias (3%) between the results of the track-structure model and the condensed-history physics model. The bias between MIRD and the results of Monte Carlo track-structure simulation was considerable (-8%). However, the point-by-point comparison revealed differences of up to 28% between the condensed-history and the track-structure MC codes for self-absorption S-values in the 10-50 keV energy range. For the cross-absorption S-values, the difference was up to 34%. In this energy range, the difference between the MIRD S-values and the Geant4-DNA results was up to 68%. Our findings suggest that the consistency/inconsistency of the results obtained with different MC simulations depends on the size of the scoring volumes, the energy of the

  1. Analytical computation of prompt gamma ray emission and detection for proton range verification

    NASA Astrophysics Data System (ADS)

    Sterpin, E.; Janssens, G.; Smeets, J.; Vander Stappen, François; Prieels, D.; Priegnitz, Marlen; Perali, Irene; Vynckier, S.

    2015-06-01

    A prompt gamma (PG) slit camera prototype recently demonstrated that Bragg Peak position in a clinical proton scanned beam could be measured with 1-2 mm accuracy by comparing an expected PG detection profile to a measured one. The computation of the expected PG detection profile in the context of a clinical framework is challenging but must be solved before clinical implementation. Obviously, Monte Carlo methods (MC) can simulate the expected PG profile but at prohibitively long calculation times. We implemented a much faster method that is based on analytical processing of precomputed MC data that would allow practical evaluation of this range monitoring approach in clinical conditions. Reference PG emission profiles were generated with MC simulations (PENH) in targets consisting of either 12C, 14N, 16O, 31P or 40Ca, with 10% of 1H. In a given geometry, the local PG emission can then be derived by adding the contribution of each element, according to the local energy of the proton obtained by continuous slowing down approximation and the local composition. The actual incident spot size is taken into account using an optical model fitted to measurements and by super sampling the spot with several rays (up to 113). PG transport in the patient/camera geometries and the detector response are modelled by convolving the PG production profile with a transfer function. The latter is interpolated from a database of transfer functions fitted to MC data (PENELOPE) generated for a photon source in a cylindrical phantom with various radiuses and a camera placed at various positions. As a benchmark, the analytical model was compared to MC and experiments in homogeneous and heterogeneous phantoms. Comparisons with MC were also performed in a thoracic CT. For all cases, the analytical model reproduced the prediction of the position of the Bragg peak computed with MC within 1 mm for the camera in nominal configuration. When compared to measurements, the shape of the profiles

  2. MCNP-based computational model for the Leksell Gamma Knife

    SciTech Connect

    Trnka, Jiri; Novotny, Josef Jr.; Kluson, Jaroslav

    2007-01-15

    We have focused on the usage of MCNP code for calculation of Gamma Knife radiation field parameters with a homogenous polystyrene phantom. We have investigated several parameters of the Leksell Gamma Knife radiation field and compared the results with other studies based on EGS4 and PENELOPE code as well as the Leksell Gamma Knife treatment planning system Leksell GammaPlan (LGP). The current model describes all 201 radiation beams together and simulates all the sources in the same time. Within each beam, it considers the technical construction of the source, the source holder, collimator system, the spherical phantom, and surrounding material. We have calculated output factors for various sizes of scoring volumes, relative dose distributions along basic planes including linear dose profiles, integral doses in various volumes, and differential dose volume histograms. All the parameters have been calculated for each collimator size and for the isocentric configuration of the phantom. We have found the calculated output factors to be in agreement with other authors' works except the case of 4 mm collimator size, where averaging over the scoring volume and statistical uncertainties strongly influences the calculated results. In general, all the results are dependent on the choice of the scoring volume. The calculated linear dose profiles and relative dose distributions also match independent studies and the Leksell GammaPlan, but care must be taken about the fluctuations within the plateau, which can influence the normalization, and accuracy in determining the isocenter position, which is important for comparing different dose profiles. The calculated differential dose volume histograms and integral doses have been compared with data provided by the Leksell GammaPlan. The dose volume histograms are in good agreement as well as integral doses calculated in small calculation matrix volumes. However, deviations in integral doses up to 50% can be observed for large

  3. Establishment of ISO 4037-1 X-ray Narrow-Spectrum Series at SSDL of Algiers.

    PubMed

    Herrati, A; Arib, M; Sidahmed, T; Khalal-Kouache, K

    2016-04-21

    The aim of this work was to develop some X-ray qualities recommended by the International Standardization Organization (ISO) in its standard ISO 4037-1. X-ray qualities corresponding to narrow-spectrum series were established, determined their characteristics and found good agreement with those of reference X-ray beam qualities [difference between first half-value layer (HVL1) < 5% for all qualities]. Acceptable results have also been obtained for second half-value layer (HVL2). The production of X-ray spectra corresponding to developed X-ray qualities with Monte Carlo code PENELOPE (PENetration and Energy Loss Of Positrons and Electrons) was simulated. The characteristics [HVL1, HVL2, homogeneity coefficient (HC) and mean energy ( ITALIC! Emean)] of simulated spectra have been calculated and compared to those of measured spectra at Physikalisch-Technische Bundesanstalt taken as reference spectra. The obtained results showed a good agreement between simulated and measured spectra (differences in HVL1, HVL2, HC and ITALIC! Emeanwere 1.7, 1.44, 0.44 and 1.3%, respectively). The comparison between simulated and measured spectra by calculating the conversion coefficients from air kerma to the personal dose equivalent, ITALIC! h ITALIC! p ITALIC! k(10), and to the ambient dose equivalent, ITALIC! h ITALIC! k(*)(10), was supplemented. The comparison between the calculated quantities ( ITALIC! h ITALIC! p ITALIC! k(10) and ITALIC! h ITALIC! k(*)(10)) for the two X-ray spectra series showed a good agreement (the maximum difference was <0.4% for ITALIC! h ITALIC! p ITALIC! k(10) and <0.3% for ITALIC! h ITALIC! k(*)(10)). Furthermore, the percentage depth dose produced in water by simulated and measured spectra was investigated and a good agreement was found between the obtained curves. The established X-ray qualities have been fully characterised (measurement and Monte Carlo simulation). These X-ray beams can be used for calibration of radiation protection instruments

  4. A Fano cavity test for Monte Carlo proton transport algorithms

    SciTech Connect

    Sterpin, Edmond; Sorriaux, Jefferson; Souris, Kevin; Vynckier, Stefaan; Bouchard, Hugo

    2014-01-15

    Purpose: In the scope of reference dosimetry of radiotherapy beams, Monte Carlo (MC) simulations are widely used to compute ionization chamber dose response accurately. Uncertainties related to the transport algorithm can be verified performing self-consistency tests, i.e., the so-called “Fano cavity test.” The Fano cavity test is based on the Fano theorem, which states that under charged particle equilibrium conditions, the charged particle fluence is independent of the mass density of the media as long as the cross-sections are uniform. Such tests have not been performed yet for MC codes simulating proton transport. The objectives of this study are to design a new Fano cavity test for proton MC and to implement the methodology in two MC codes: Geant4 and PENELOPE extended to protons (PENH). Methods: The new Fano test is designed to evaluate the accuracy of proton transport. Virtual particles with an energy ofE{sub 0} and a mass macroscopic cross section of (Σ)/(ρ) are transported, having the ability to generate protons with kinetic energy E{sub 0} and to be restored after each interaction, thus providing proton equilibrium. To perform the test, the authors use a simplified simulation model and rigorously demonstrate that the computed cavity dose per incident fluence must equal (ΣE{sub 0})/(ρ) , as expected in classic Fano tests. The implementation of the test is performed in Geant4 and PENH. The geometry used for testing is a 10 × 10 cm{sup 2} parallel virtual field and a cavity (2 × 2 × 0.2 cm{sup 3} size) in a water phantom with dimensions large enough to ensure proton equilibrium. Results: For conservative user-defined simulation parameters (leading to small step sizes), both Geant4 and PENH pass the Fano cavity test within 0.1%. However, differences of 0.6% and 0.7% were observed for PENH and Geant4, respectively, using larger step sizes. For PENH, the difference is attributed to the random-hinge method that introduces an artificial energy

  5. Determination of absorbed dose in water at the reference point d(r0, theta0) for an 192Ir HDR brachytherapy source using a Fricke system.

    PubMed

    Austerlitz, C; Mota, H C; Sempau, J; Benhabib, S M; Campos, D; Allison, R; DeAlmeida, C E; Zhu, D; Sibata, C H

    2008-12-01

    A ring-shaped Fricke device was developed to measure the absolute dose on the transverse bisector of a 192Ir high dose rate (HDR) source at 1 cm from its center in water, D(r0, theta0). It consists of a polymethylmethacrylate (PMMA) rod (axial axis) with a cylindrical cavity at its center to insert the 192Ir radioactive source. A ring cavity around the source with 1.5 mm thickness and 5 mm height is centered at 1 cm from the central axis of the source. This ring cavity is etched in a disk shaped base with 2.65 cm diameter and 0.90 cm thickness. The cavity has a wall around it 0.25 cm thick. This ring is filled with Fricke solution, sealed, and the whole assembly is immersed in water during irradiations. The device takes advantage of the cylindrical geometry to measure D(r0, theta0). Irradiations were performed with a Nucletron microselectron HDR unit loaded with an 192Ir Alpha Omega radioactive source. A Spectronic 1001 spectrophotometer was used to measure the optical absorbance using a 1 mL quartz cuvette with 1.00 cm light pathlength. The PENELOPE Monte Carlo code (MC) was utilized to simulate the Fricke device and the 192Ir Alpha Omega source in detail to calculate the perturbation introduced by the PMMA material. A NIST traceable calibrated well type ionization chamber was used to determine the air-kerma strength, and a published dose-rate constant was used to determine the dose rate at the reference point. The time to deliver 30.00 Gy to the reference point was calculated. This absorbed dose was then compared to the absorbed dose measured by the Fricke solution. Based on MC simulation, the PMMA of the Fricke device increases the D(r0, theta0) by 2.0%. Applying the corresponding correction factor, the D(r0, theta0) value assessed with the Fricke device agrees within 2.0% with the expected value with a total combined uncertainty of 3.43% (k=1). The Fricke device provides a promising method towards calibration of brachytherapy radiation sources in terms of D(r0

  6. Metal-silicate partitioning experiments in the diamond anvil cell: A comment on potential analytical errors

    NASA Astrophysics Data System (ADS)

    Wade, Jon; Wood, Bernard J.

    2012-02-01

    We have performed simulations of the electron microbeam analysis of metal-silicate partitioning experiments in which a small (˜50 μm) ball of metal is embedded in a silicate matrix. This geometry approximates that found in many high pressure diamond-cell experiments aimed at determining the partition coefficients (Di) of elements between metal and silicate. The simulations involved using the (publicly available) Monte Carlo simulation package PENEPMA which is based on the general-purpose electron-photon transport code PENELOPE. The code allows complex geometrical structures to be defined by quadric surfaces, which enclose homogeneous materials specified by the user. The package simulates both electron and photon transport, keeps track of the X-ray production mechanism and includes the continuum contribution. Our principal results came from simulating the effects of secondary fluorescence on the apparent metal-silicate partition coefficient of Ni for the case of an Ni-rich metal (26.8% Ni, 73.2% Fe) embedded in a silicate matrix. If, as is frequently the case, analysis of the silicate is performed 5-10 μm from the silicate-metal interface then secondary fluorescence of Ni in the metal will increase the apparent NiO concentration in the silicate by ˜1000 ppm. In the case considered, this is 25% of the Ni content of the silicate and the fluorescence effect decreases the apparent DNi from 110 to 84. For this type of experiment, therefore, the fluorescence effect reduces the apparent partition coefficient. We performed similar simulations of the analysis of the centre of a 10 μm diameter metal ball embedded in the silicate matrix to determine apparent Si and O concentrations in the metal. In this case, because the electrons do not penetrate so far into the metal, the fluorescence effect is very small and can be neglected. Finally, we show that focused ion beam (FIB) sections, while providing the potential physically to separate metal from silicate present

  7. A comparison between track-structure, condensed-history Monte Carlo simulations and MIRD cellular S-values

    NASA Astrophysics Data System (ADS)

    Tajik-Mansoury, M. A.; Rajabi, H.; Mazdarani, H.

    2017-03-01

    The S-value is a standard measure in cellular dosimetry. S-values are calculated by applying analytical methods or by Monte Carlo simulation. In Monte Carlo simulation, particles are either tracked individually event-by-event or close events are condensed and processed collectively in different steps. Both of these methods have been employed for estimation of cellular S-values, but there is no consistency between the published results. In the present paper, we used the Geant4-DNA track-structure physics model as the reference to estimate the cellular S-values. We compared the results with the corresponding values obtained from the following three condensed-history physics models of Geant4: Penelope, Livermore and standard. The geometry and source were exactly the same in all the simulations. We utilized mono-energetic electrons with an initial kinetic energy in the range 1–700 keV as the source of radiation. We also compared our results with the MIRD S-values. We first drew an overall comparison between different data series and then compared the dependence of results on the energy of particles and the size of scoring compartments. The overall comparison indicated a very good linear correlation (R 2  >  91%) and small bias (3%) between the results of the track-structure model and the condensed-history physics model. The bias between MIRD and the results of Monte Carlo track-structure simulation was considerable (‑8%). However, the point-by-point comparison revealed differences of up to 28% between the condensed-history and the track-structure MC codes for self-absorption S-values in the 10–50 keV energy range. For the cross-absorption S-values, the difference was up to 34%. In this energy range, the difference between the MIRD S-values and the Geant4-DNA results was up to 68%. Our findings suggest that the consistency/inconsistency of the results obtained with different MC simulations depends on the size of the scoring volumes, the energy of the

  8. Application of Monte Carlo methods in tomotherapy and radiation biophysics

    NASA Astrophysics Data System (ADS)

    Hsiao, Ya-Yun

    Helical tomotherapy is an attractive treatment for cancer therapy because highly conformal dose distributions can be achieved while the on-board megavoltage CT provides simultaneous images for accurate patient positioning. The convolution/superposition (C/S) dose calculation methods typically used for Tomotherapy treatment planning may overestimate skin (superficial) doses by 3-13%. Although more accurate than C/S methods, Monte Carlo (MC) simulations are too slow for routine clinical treatment planning. However, the computational requirements of MC can be reduced by developing a source model for the parts of the accelerator that do not change from patient to patient. This source model then becomes the starting point for additional simulations of the penetration of radiation through patient. In the first section of this dissertation, a source model for a helical tomotherapy is constructed by condensing information from MC simulations into series of analytical formulas. The MC calculated percentage depth dose and beam profiles computed using the source model agree within 2% of measurements for a wide range of field sizes, which suggests that the proposed source model provides an adequate representation of the tomotherapy head for dose calculations. Monte Carlo methods are a versatile technique for simulating many physical, chemical and biological processes. In the second major of this thesis, a new methodology is developed to simulate of the induction of DNA damage by low-energy photons. First, the PENELOPE Monte Carlo radiation transport code is used to estimate the spectrum of initial electrons produced by photons. The initial spectrum of electrons are then combined with DNA damage yields for monoenergetic electrons from the fast Monte Carlo damage simulation (MCDS) developed earlier by Semenenko and Stewart (Purdue University). Single- and double-strand break yields predicted by the proposed methodology are in good agreement (1%) with the results of published

  9. Comparison of patient specific dose metrics between chest radiography, tomosynthesis, and CT for adult patients of wide ranging body habitus

    SciTech Connect

    Zhang, Yakun; Li, Xiang; Segars, W. Paul; Samei, Ehsan

    2014-02-15

    Purpose: Given the radiation concerns inherent to the x-ray modalities, accurately estimating the radiation doses that patients receive during different imaging modalities is crucial. This study estimated organ doses, effective doses, and risk indices for the three clinical chest x-ray imaging techniques (chest radiography, tomosynthesis, and CT) using 59 anatomically variable voxelized phantoms and Monte Carlo simulation methods. Methods: A total of 59 computational anthropomorphic male and female extended cardiac-torso (XCAT) adult phantoms were used in this study. Organ doses and effective doses were estimated for a clinical radiography system with the capability of conducting chest radiography and tomosynthesis (Definium 8000, VolumeRAD, GE Healthcare) and a clinical CT system (LightSpeed VCT, GE Healthcare). A Monte Carlo dose simulation program (PENELOPE, version 2006, Universitat de Barcelona, Spain) was used to mimic these two clinical systems. The Duke University (Durham, NC) technique charts were used to determine the clinical techniques for the radiographic modalities. An exponential relationship between CTDI{sub vol} and patient diameter was used to determine the absolute dose values for CT. The simulations of the two clinical systems compute organ and tissue doses, which were then used to calculate effective dose and risk index. The calculation of the two dose metrics used the tissue weighting factors from ICRP Publication 103 and BEIR VII report. Results: The average effective dose of the chest posteroanterior examination was found to be 0.04 mSv, which was 1.3% that of the chest CT examination. The average effective dose of the chest tomosynthesis examination was found to be about ten times that of the chest posteroanterior examination and about 12% that of the chest CT examination. With increasing patient average chest diameter, both the effective dose and risk index for CT increased considerably in an exponential fashion, while these two dose

  10. Tethys - Geological and Spectral Properties

    NASA Astrophysics Data System (ADS)

    Stephan, Katrin; Jaumann, Ralf; Wagner, Roland; Clark, Roger N.; Cruikshank, Dale P.; Dalle Ore, Cristina; Brown, Robert H.; Giese, Bernd; Roatsch, Thomas; Matson, Dennis; Baines, Kevin H.; Filacchione, Gianrico; Capaccione, Fabrizio; Burratti, Bonnie J.; Nicholson, Phil D.; Rodriguez, Sebastian

    2015-04-01

    Despite the spectral dominance of H2O ice on Tethys' surface, distinct spectral variations derived by the Cassini VIMS instrument could be detected. The ice infrared absorption strengths are very different from what was expected from the visible albedo derived from Voyager and Cassini camera data. Although on Tethys, the major ice absorptions at 1.5 and 2µm are general stronger on the leading hemisphere of the satellite similar to that seen on the neighboring satellites Dione and Rhea, the detailed mapping shows a more complex pattern. Two relatively narrow N/S trending bands enriched in H2O ice of relatively large particle size separate the Saturn-facing and the anti-Saturnian hemisphere. The largest impact crater Odysseus (33°N/129°W) is included in the N/S trending band of deeper H2O absorptions on the leading hemisphere, whereas the geologically older and fourth largest impact crater Penelope (11°S/249°W) is excluded from the 'icy' band on the trailing hemisphere - supporting an exogenic origin of these bands. The oval shaped dark albedo unit observed by Voyager in the equatorial region of Tethys' leading hemisphere, which could be related to magnetospheric 'dust' impacting the surface, exhibits slightly surpressed H2O ice absorptions compared to their surrounding regions. Variations in the spectral slope from the visible to the ultra-violet wavelength range are similar to the variations observed by Cassini ISS. The spectral slope is steepest (i.e. the effect of an ultra-violet absorber other than H2O ice is strongest) on the leading as well on the trailing hemisphere. No spectral properties could be exclusively associated with Tethys' extended graben system Ithaca Chasma. Local variations, i.e. local deepening of H2O ice absorptions, are mostly related to several probably fresh impact craters and to locations where topographic slope is high like crater walls. However, only a few such fresh impact craters could be observed.

  11. Evaluation of position-estimation methods applied to CZT-based photon-counting detectors for dedicated breast CT

    PubMed Central

    Makeev, Andrey; Clajus, Martin; Snyder, Scott; Wang, Xiaolang; Glick, Stephen J.

    2015-01-01

    Abstract. Semiconductor photon-counting detectors based on high atomic number, high density materials [cadmium zinc telluride (CZT)/cadmium telluride (CdTe)] for x-ray computed tomography (CT) provide advantages over conventional energy-integrating detectors, including reduced electronic and Swank noise, wider dynamic range, capability of spectral CT, and improved signal-to-noise ratio. Certain CT applications require high spatial resolution. In breast CT, for example, visualization of microcalcifications and assessment of tumor microvasculature after contrast enhancement require resolution on the order of 100  μm. A straightforward approach to increasing spatial resolution of pixellated CZT-based radiation detectors by merely decreasing the pixel size leads to two problems: (1) fabricating circuitry with small pixels becomes costly and (2) inter-pixel charge spreading can obviate any improvement in spatial resolution. We have used computer simulations to investigate position estimation algorithms that utilize charge sharing to achieve subpixel position resolution. To study these algorithms, we model a simple detector geometry with a 5×5 array of 200  μm pixels, and use a conditional probability function to model charge transport in CZT. We used COMSOL finite element method software to map the distribution of charge pulses and the Monte Carlo package PENELOPE for simulating fluorescent radiation. Performance of two x-ray interaction position estimation algorithms was evaluated: the method of maximum-likelihood estimation and a fast, practical algorithm that can be implemented in a readout application-specific integrated circuit and allows for identification of a quadrant of the pixel in which the interaction occurred. Both methods demonstrate good subpixel resolution; however, their actual efficiency is limited by the presence of fluorescent K-escape photons. Current experimental breast CT systems typically use detectors with a pixel size of 194

  12. Space Radar Image of Manaus, Brazil

    NASA Technical Reports Server (NTRS)

    1999-01-01

    changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.v. (DLR), the major partner in science, operations and data processing of X-SAR.

  13. Space Radar Image of Kennedy Space Center, Florida

    NASA Technical Reports Server (NTRS)

    1999-01-01

    companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V.(DLR), the major partner in science, operations and data processing of X-SAR.

  14. SPace Radar Image of Fort Irwin, California

    NASA Technical Reports Server (NTRS)

    1994-01-01

    activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V.(DLR), the major partner in science, operations and data processing of X-SAR.

  15. Space Radar Image of Kilauea, Hawaii - interferometry 1

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This X-band image of the volcano Kilauea was taken on October 4, 1994, by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar. The area shown is about 9 kilometers by 13 kilometers (5.5 miles by 8 miles) and is centered at about 19.58 degrees north latitude and 155.55 degrees west longitude. This image and a similar image taken during the first flight of the radar instrument on April 13, 1994 were combined to produce the topographic information by means of an interferometric process. This is a process by which radar data acquired on different passes of the space shuttle is overlaid to obtain elevation information. Three additional images are provided showing an overlay of radar data with interferometric fringes; a three-dimensional image based on altitude lines; and, finally, a topographic view of the region. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V.(DLR), the major partner in science, operations and data processing of X-SAR. The Instituto Ricerca Elettromagnetismo

  16. space Radar Image of Long Valley, California

    NASA Technical Reports Server (NTRS)

    1994-01-01

    environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V.(DLR), the major partner in science, operations and data processing of X-SAR.

  17. Space Radar Image of Long Valley, California in 3-D

    NASA Technical Reports Server (NTRS)

    1994-01-01

    induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.v. (DLR), the major partner in science, operations and data processing of X-SAR.

  18. Space Radar Image of Raco Vegetation Map

    NASA Technical Reports Server (NTRS)

    1999-01-01

    companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.v. (DLR), the major partner in science, operations and data processing of X-SAR.

  19. Space Radar Image of Central African Gorilla Habitat

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.v. (DLR), the major partner in science, operations and data processing of X-SAR.

  20. North Central Thailand

    NASA Technical Reports Server (NTRS)

    1998-01-01

    NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.v.(DLR), the major partner in science, operations, and data processing of X-SAR.

  1. Space Radar Image of Raco Biomass Map

    NASA Technical Reports Server (NTRS)

    1999-01-01

    space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.v. (DLR), the major partner in science, operations and data processing of X-SAR.

  2. Space Radar Image of Colima Volcano, Jalisco, Mexico

    NASA Technical Reports Server (NTRS)

    1994-01-01

    and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V.(DLR), the major partner in science, operations and data processing of X-SAR.

  3. Space Radar Image of Hong Kong, China

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is an X-SAR image spanning an area of approximately 20 kilometers by 40 kilometers (12 miles by 25 miles) of the island of Hong Kong, the Kowloon Peninsula and the new territories in southern China, taken by the imaging radar on board the space shuttle Endeavour on October 4, 1994. North is toward the top left corner of the image. The Kaitak Airport runway on Kowloon Peninsula (center right of image) was built on reclaimed land and extends almost 3 kilometers (nearly 2 miles) into Victoria Harbor. To the south of the harbor lies the island of Hong Kong. The bright areas around the harbor are the major residential and business districts. Housing more than six million residents, Hong Kong is the most densely populated area in the world. The large number of objects visible in the harbor and surrounding waters are a variety of sea-going vessels, anchored in one of the busiest seaports in the Far East. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V.(DLR), the major partner in

  4. Stem cell origin of cancer and differentiation therapy.

    PubMed

    Sell, Stewart

    2004-07-01

    Our forefathers in pathology, on observing cancer tissue under the microscope in the mid-19th century, noticed the similarity between embryonic tissue and cancer, and suggested that tumors arise from embryo-like cells [Recherches dur le Traitement du Cancer, etc. Paris. (1829); Editoral Archiv fuer pathologische Anatomie und Physiologie und fuer klinische Medizin 8 (1855) 23]. The concept that adult tissues contain embryonic remnants that generally lie dormant, but that could be activated to become cancer was later formalized by Cohnheim [Path. Anat. Physiol. Klin. Med. 40 (1867) 1-79; Virchows Arch. 65 (1875) 64] and Durante [Arch. Memori ed Osservazioni di Chirugia Practica 11 (1874) 217-226], as the "embryonal rest" theory of cancer. An updated version of the embryonal rest theory of cancer is that cancers arise from tissue stem cells in adults. Analysis of the cellular origin of carcinomas of different organs indicates that there is, in each instance, a determined stem cell required for normal tissue renewal that is the most likely cell of origin of carcinomas [Lab. Investig. 70 (1994) 6-22]. In the present review, the nature of normal stem cells (embryonal, germinal and somatic) is presented and their relationships to cancer are further expanded. Cell signaling pathways shared by embryonic cells and cancer cells suggest a possible link between embryonic cells and cancer cells. Wilm's tumors (nephroblastomas) and neuroblastomas are presented as possible tumors of embryonic rests in children. Teratocarcinoma is used as the classic example of the totipotent cancer stem cell which can be influenced by its environment to differentiate into a mature adult cell. The observation that "promotion" of an epidermal cancer may be accomplished months or even years after the initial exposure to carcinogen ("initiation"), implies that the original carcinogenic event occurs in a long-lived epithelial stem cell population. The cellular events during hepatocarcinogenesis

  5. Evaluation of the long-term efficacy and safety of an imidacloprid 10%/flumethrin 4.5% polymer matrix collar (Seresto®) in dogs and cats naturally infested with fleas and/or ticks in multicentre clinical field studies in Europe

    PubMed Central

    2012-01-01

    Background The objective of these two GCP multicentre European clinical field studies was to evaluate the long-term efficacy and safety of a new imidacloprid/flumethrin collar (Seresto®, Bayer AnimalHealth, Investigational Veterinary Product(IVP)) in dogs and cats naturally infested with fleas and/or ticks in comparison to a dimpylat collar ("Ungezieferband fuer Hunde/fuer Katzen", Beaphar, Control Product (CP)). Methods 232 (IVP) and 81 (CP) cats and 271(IVP) and 129 (CP) dogs were treated with either product according to label claims and formed the safety population. Flea and tick counts were conducted in monthly intervals for up to 8 months in the efficacy subpopulation consisting of 118 (IVP) + 47 (CP) cats and 197 (IVP) + 94 (CP) dogs. Efficacy was calculated as reduction of infestation rate within the same treatment group and statistically compared between the two treatment groups. Results Preventive efficacy against fleas in cats/dogs varied in the IVP group between 97.4%/94.1% and 100%/100% (overall mean: 98.3%/96.7%) throughout the 8 month period and in the CP group between 57.1%/28.2% and 96.1%/67.8% (overall mean: 79.3%/57.9%). Preventive efficacy against ticks in cats/dogs varied in the IVP group between 94.0%/91.2% and 100%/100% (overall mean: 98.4%/94.7%) throughout the 8 month period and in the CP group between 90.7%/79.9% and 100%/88.0% (overall mean: 96.9%/85.6%). The IVP group was statistically non-inferior to the CP group, and on various assessment days, statistical superiority was proven for flea and tick count reduction in dogs and cats. Both treatments proved to be safe in dogs and cats with mainly minor local observations at the application site. There was moreover, no incidence of any mechanical problem with the collar in dogs and cats during the entire study period. Conclusions The imidacloprid/flumethrin collar proved to reduce tick counts by at least 90% and flea counts by at least 95% for a period of at least 7-8 months in cats and dogs

  6. Space Radar Image of San Francisco, California

    NASA Technical Reports Server (NTRS)

    1994-01-01

    which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V. (DLR), the major partner in science, operations and data processing of X-SAR.

  7. Compton Scattering and the Nucleon Polarizabilities in the A2 Collaboration at MAMI

    NASA Astrophysics Data System (ADS)

    Downie, Evangeline; MAMI A2 Collaboration

    2014-09-01

    There has been an upsurge in interest in Compton Scattering experiments as a means to understand the internal structure and dynamics of the nucleon. The new PDG value of β, the proton magnetic polarizability, changed noticeably, with no new data, simply new theoretical treatment of the existing data set. This indicates that the existing data is insufficient to constrain our extraction of these fundamental constants, which are important in areas of physics such as the proton radius determination, and neutron star physics. In the A2 Collaboration of the Institut fuer Kernphysik in Mainz, we use the MAMI accelerator with the Glasgow Mainz Photon Tagger to produce a quasi-monoenergetic, linearly polarized photon beam and apply it to a liquid hydrogen target. The reaction products detected in the Crystal Ball and TAPS large acceptance spectrometer array allow clean separation of the low-cross-section hadronic Compton scattering process. In so doing, we have produced the firs t measurement of the photon asymmetry in Compton scattering on the proton below the pion production threshold. Preliminary results show a demonstrable effect due to the polarizabilities. We will cover the experimental results and future prospects of the A2 polarizability program. There has been an upsurge in interest in Compton Scattering experiments as a means to understand the internal structure and dynamics of the nucleon. The new PDG value of β, the proton magnetic polarizability, changed noticeably, with no new data, simply new theoretical treatment of the existing data set. This indicates that the existing data is insufficient to constrain our extraction of these fundamental constants, which are important in areas of physics such as the proton radius determination, and neutron star physics. In the A2 Collaboration of the Institut fuer Kernphysik in Mainz, we use the MAMI accelerator with the Glasgow Mainz Photon Tagger to produce a quasi-monoenergetic, linearly polarized photon beam and

  8. Training of leadership skills in medical education.

    PubMed

    Kiesewetter, Jan; Schmidt-Huber, Marion; Netzel, Janine; Krohn, Alexandra C; Angstwurm, Matthias; Fischer, Martin R

    2013-01-01

    Hintergrund: Eine effektive Zusammenarbeit in Teams ist eine wichtige Voraussetzung für qualitativ hochwertige Versorgung im Gesundheitswesen. In diesem Zusammenhang spielen auch Führungskompetenzen von Ärztinnen und Ärzten im klinischen Alltag eine wichtige Rolle. Bisher wurde die Entwicklung von Führungskompetenzen in medizinischen Curricula in der Aus- und Weiterbildung von Ärztinnen und Ärzten jedoch kaum systematisch abgebildet. Die Entwicklung adäquater und effektiver Trainingsmethoden für die Vermittlung von Führungskompetenzen ist daher wünschenswert. Ziel: Das Review soll vorliegende Ergebnisse der Literatur zu Trainings von Führungskompetenzen in der Medizin zusammenfassen und integrieren, um zukünftige Forschung und Trainingsentwicklung anzuregen. Methode: Die Datenbanken PubMED, ERIC, PsycArticles, PsycINFO, PSYNDEX und dem Academic search complete durch EBSCOhost wurden auf Deutsch und Englisch nach Trainings von Führungskompetenzen in der Medizin durchsucht. Relevante Artikel wurden identifiziert und die Studienergebnisse hinsichtlich des zugrundeliegenden Führungsverständnisses, der Zielgruppe und Teilnehmeranzahl, der zeitlichen Ressourcen, sowie der Inhalte und Methoden des Trainings, des Evaluationsdesigns und der berichteten Trainingseffekte zusammengefasst. Ergebnisse: Auf acht Studien trafen alle Einschluss- und kein Ausschlusskriterium zu. Die Trainings selbst sowie die thematisierten Führungskompetenzen differenzieren jedoch stark voneinander. Die Trainingsdesigns beinhalten im Schwerpunkt die theoretische Auseinandersetzung mit dem Thema Führung sowie die Diskussion von Fallstudien aus der Praxis. Die Dauer der Trainings reicht von mehrstündigen bis hin zu mehrjährigen Veranstaltungen. Die selbst eingeschätzte Reaktion der Teilnehmer auf alle Trainings war positiv; es fand jedoch bisher keine systematische Überprüfung des Trainingserfolgs in Bezug auf konkrete Verhaltensänderungen der Teilnehmer statt

  9. A short form of the General Self-Efficacy Scale (GSE-6): Development, psychometric properties and validity in an intercultural non-clinical sample and a sample of patients at risk for heart failure.

    PubMed

    Romppel, Matthias; Herrmann-Lingen, Christoph; Wachter, Rolf; Edelmann, Frank; Düngen, Hans-Dirk; Pieske, Burkert; Grande, Gesine

    2013-01-01

    Instrument, das zur ökonomischen Erfassung der generalisierten Selbstwirksamkeit in großen multivariaten Studien und zum Einsatz als Screeninginstrument geeignet ist.

  10. Impact of the Medical Faculty on Study Success in Freiburg: Results from Graduate Surveys.

    PubMed

    Biller, Silke; Boeker, Martin; Fabry, Götz; Giesler, Marianne

    2015-01-01

    , die die Lehre beschreiben, leisten kaum einen Beitrag zur Vorhersage der schriftlichen M2-Note, was insofern nachvollziehbar ist, als die Lehre weit über den stark wissensorientierten Inhalt des M2-schriftlich hinausgeht. Die mangelnde Vorhersagbarkeit der Wissenschaftskompetenz ist am ehesten damit erklärbar, dass diese Kompetenz bisher nur wenig und häufig nicht expliziter Bestandteil des Curriculums ist. Die Variable Verknüpfung von Theorie und Praxis scheint für die Ausbildung der Fachkompetenz und die Ausprägung der Studienzufriedenheit bedeutsam zu sein. Inwieweit diese Beziehungen praktisch relevant sind, soll in weiteren Studien geklärt werden. Limitierend ist insbesondere anzumerken, dass die Kompetenzerfassung ausschließlich auf Selbsteinschätzungen beruht.

  11. Study protocol of the Diabetes and Depression Study (DAD): a multi-center randomized controlled trial to compare the efficacy of a diabetes-specific cognitive behavioral group therapy versus sertraline in patients with major depression and poorly controlled diabetes mellitus

    PubMed Central

    2013-01-01

    hypothesis we expect that CBT leads to significantly greater improvement of glycemic control in the one year follow-up in treatment responders of the short term phase. Discussion The DAD study is the first randomized controlled trial comparing antidepressants to a psychological treatment in diabetes patients with depression. The study is investigator initiated and was supported by the ‘Förderprogramm Klinische Studien (Clinical Trials)’ and the ‘Competence Network for Diabetes mellitus’ funded by the Federal Ministry of Education and Research (FKZ 01KG0505). Trial registration Current controlled trials ISRCTN89333241. PMID:23915015

  12. Landscape and vegetation change on the Iberian Peninsula during the Roman Epoch - A reconstruction based on Geo-Bioarchives

    NASA Astrophysics Data System (ADS)

    Schneider, Heike

    2010-05-01

    Huerva. Postgrado en Ingeneria de los Recursos Hidricos, Zaragoza. Teichner, F. (2007): Zwischen Land und Meer - Entre tierra y mar. Studien zur Architektur und Wirtschaftsweise ländlicher Siedlungen im Süden der römischen Provinz Lusitanien. - Stvdia Lvsitana 3 (MNAR) / Madrider Beitr. (DAI). Thorndycraft, V.R. & G. Benito (2006a): Late Holocene fluvial chronology of Spain: The role of climatic variability and human impact. - Catena 66 (1-2): 34-41. Thorndycraft, V.R. & G. Benito (2006b): The Holocene fluvial chronology of Spain: evidence from a newly compiled radiocarbon database. - Quaternary Science Reviews 25 (3-4): 223-234.

  13. Electronic acquisition of OSCE performance using tablets.

    PubMed

    Hochlehnert, Achim; Schultz, Jobst-Hendrik; Möltner, Andreas; Tımbıl, Sevgi; Brass, Konstantin; Jünger, Jana

    2015-01-01

    hinsichtlich Prüfungsdokumentation, Ressourceneinsatz und Fehleranfälligkeit gegenüber der papierbasierten Form Vorteile bietet, was Gegenstand weiterer Studien sein sollte.

  14. The use of Facebook in medical education--a literature review.

    PubMed

    Pander, Tanja; Pinilla, Severin; Dimitriadis, Konstantinos; Fischer, Martin R

    2014-01-01

    Hintergrund: Die Verbreitung sozialer Medien beeinflusst und verändert die Kommunikationskultur sowie die Lern- und Lehrmöglichkeiten in der medizinischen Ausbildung. Das beliebteste soziale Netzwerk ist Facebook. Seine Eigenschaften bieten ein großes Potenzial für die medizinische Ausbildung, bringen aber auch einige neue Herausforderungen mit sich.Ziele: Dieser systematische Literaturüberblick zielt darauf ab, herauszufinden, wie Facebook bisher in der medizinischen Ausbildung integriert, eingesetzt und beforscht wurde. Nach einer systematischen Durchsicht der aktuellen Literatur, werden Forschungslücken identifiziert, Verbindungen zu vorherigen Arbeiten gezogen, die bisherigen Ergebnisse systematisch analysiert und Konsequenzen diskutiert.Methode: Die Autoren durchsuchten sechs online-basierte Literatur-Datenbanken. Sie definierten Einschlusskriterien und überprüften unabhängig voneinander die Suchergebnisse. Die wichtigsten Informationen der Artikel wurden methodisch abstrahiert und kodiert und in den Kategorien Studiendesign, Phase der Studienteilnehmer in der medizinischen Ausbildung und Studieninhalt dargestellt und diskutiert.Ergebnisse: 16 Artikel erfüllten alle Einschlusskriterien. 45-96% der Mediziner und Medizinstudierenden haben ein Facebook-Profil. Die meisten Studien konzentrierten sich auf Facebook und digitale Professionalität. Unprofessionelles Verhalten und Verstöße gegen den Datenschutz traten in 0,02% bis 16% der Fälle auf. In Hinblick auf den Einsatz als Lehr- und Lernumgebung wird Facebook von Medizinstudierenden gut akzeptiert. Es wird verwendet, um sich für Prüfungen vorzubereiten, Online-Materialien zu teilen, klinische Fälle zu diskutieren, Treffen zu organisieren und Informationen über Famulaturen auszutauschen. Einige Unterrichtsmaterialien für den professionellen Umgang mit Facebook wurden positiv beurteilt. Es scheint allerdings keine Beweise dafür zu geben, dass Medizinstudierende von Facebook als Lernumgebung

  15. Practice nursed-based, individual and video-assisted patient education in oral anticoagulation - Protocol of a cluster-randomized controlled trial

    PubMed Central

    2011-01-01

    observe differences in adverse effects, we expect to discover differences in secondary outcomes, such as the time spent in the therapeutic range. Trial registration Deutsches Register Klinischer Studien (German Clinical Trials Register): DRKS00000586 Universal Trial Number (UTN U1111-1118-3464) PMID:21477372

  16. Sustained Increase of 25-Hydroxyvitamin D Levels in Healthy Young Women during Wintertime after Three Suberythemal UV Irradiations—The MUVY Pilot Study

    PubMed Central

    Biersack, Maria Gudrun; Hajdukiewicz, Malgorzata; Uebelhack, Ralf; Franke, Leonora; Piazena, Helmut; Klaus, Pascal; Höhne-Zimmer, Vera; Braun, Tanja; Buttgereit, Frank; Burmester, Gerd-Rüdiger; Detert, Jacqueline

    2016-01-01

    young women with VitD deficient status. Trial Registration German Clinical Trials Register (Deutsches Register Kinischer Studien) DRKS00009274 PMID:27434043

  17. Deglaciation and post-glacial environmental evolution in the Western Massif of Picos de Europa

    NASA Astrophysics Data System (ADS)

    Ruiz-Fernández, Jesús; Oliva, Marc; García, Cristina; López-Sáez, José Antonio; Gallinar, David; Geraldes, Miguel

    2014-05-01

    This study examines the process of deglaciation of the Western Massif of Picos de Europa through field work, geomorphological mapping, sedimentary records and absolute datings of 14C. This massif has several peaks over 2,400 m a.s.l. (Peña Santa de Castilla, 2,596 m; Torre Santa María, 2,486 m; Torre del Mediu, 2,467 m). It is composed mainly by Carboniferous limestones. This area has been intensively affected by karstic dissolution, Quaternary glaciers and fluvio-torrential processes (Miotke, 1968; Moreno et al, 2010; Ruiz-Fernández et al, 2009; Ruiz-Fernández, 2013). At present day, periglacial processes are active at the highest elevations (Ruiz-Fernández, 2013). We have identified four main glacial stages regarding the deglaciation of the massif: (i) maximum advance corresponding to the Last Glaciation, (ii) retreat and stabilization after the maximum advance, (iii) Late Glacial, and (iv) Little Ice Age. Sedimentological studies also contribute data to the understanding of the chronological framework of these environmental changes. The datings of the bottom sediments in two long sequences (8 and 5.4 m) provided a minimum age of 18,075 ± 425 cal BP for the maximum advance stage and 11,150 ± 900 cal BP for retreat and stabilization in the phase following the maximum advance. The ongoing analyses of these sequences at very high resolution will provide new knowledge about the environmental conditions prevailing since the deglaciation of the massif. References Miotke, F.D. (1968). Karstmorphologische studien in der glazial-überformten Höhenstufe der Picos de Europa, Nordspanien. Hannover, Selbtverlag der Geografischen Gessellschaft, 161 pp. Moreno, A., Valero, B.L., Jiménez, M., Domínguez, M.J., Mata, M.P., Navas, A., González, P., Stoll, H., Farias, P., Morellón, M., Corella, J.P. & Rico, M. (2010). The last deglaciation in the Picos de Europa National Park (Cantabrian Mountains, Northern Spain). Journal of Quaternary Science, 25 (7), 1076-1091. Ruiz

  18. Early Monitoring of Response (MORE) to Golimumab Therapy Based on Fecal Calprotectin and Trough Serum Levels in Patients With Ulcerative Colitis: A Multicenter Prospective Study

    PubMed Central

    Drabik, Attyla; Sturm, Andreas; Blömacher, Margit

    2016-01-01

    Background The treatment of ulcerative colitis (UC) patients with moderate to severe inflammatory activity with anti-tumor necrosis factor alpha (TNFα) antibodies leads to a clinical remission rate of 10% after 8 weeks of therapy. However, it must be taken into account that patient selection in clinical trials clearly influences both response and remission rates. An unsatisfactory response to anti-TNFα medication after week 12 often leads to a discontinuation of treatment. The early prediction of clinical response could therefore help optimize therapy and potentially avoid ineffective treatments. Objective The aim of this study is to develop an algorithm for optimizing golimumab administration in patients with moderate to severe UC by calculating the probability of clinical response in Week 26 based on data from Week 6. Methods The study is designed as a prospective, single-arm, multicenter, non-interventional observational study with no interim analyses and a sample size of 58 evaluable patients. The primary outcome is the prediction of clinical response in Week 26 based on a 50% reduction in fecal calprotectin and a positive golimumab trough level in Week 6. Results Enrollment started in October 2014 and was still open at the date of submission. The study is expected to finish in December 2016. Conclusions The early identification of patients who are responding to an anti-TNFα antibody is therapeutically beneficial. At the same time, patients who are not responding can be identified earlier. The development of a therapeutic algorithm for identifying patients as responders or non-responders can thus help prescribing physicians to both avoid ineffective treatments and adjust dosages when necessary. This in turn promotes a higher degree of treatment tolerance and patient safety in the case of anti-TNFα antibody administration. ClinicalTrial German Clinical Trials Register, Deutsches Register Klinischer Studien DRKS00005940; https://drks-neu.uniklinik-freiburg.de

  19. Development of an advanced regional climate-ecosystem model for Arctic applications

    NASA Astrophysics Data System (ADS)

    Chaudhary, Nitin; Smith, Benjamin; Miller, Paul

    2013-04-01

    approaches. Global Ecology and Biogeography, Vol. 10, pp: 621-637. Smith B, Samuelsson P, Wramneby A, and Rummukainen M. 2010. A Model of the coupled dynamics of climate, vegetation and terrestrial ecosystem biogeochemistry for regional applications. Tellus, Vol: 63A, Issue: 1, pp: 87-106 von Post L and Sernander R. 1910. Pflanzen-physiognomische Studien aus Torfmooren in Närke. XI International Geological Congress: Excursion Guide No: 14(A7), Stockholm, pp: 48

  20. [Ethics as a scientific basis for animal protection - on the advancement and amendment of the Codex Veterinarius].

    PubMed

    Kuhlmann, Ingrid; Luy, Joerg

    2005-01-01

    Seven years ago, the veterinary association for animal protection (Tieraerztliche Vereinigung fuer Tierschutz e.V., TVT) in Germany first published an orientation guide on the ethics of animal protection aimed at the entire veterinary profession: the "Codex Veterinarius - ethical guiding principles on veterinary action for the good and the protection of animals". The dilemmas of the veterinary profession have not changed since then, but as the principle that "nothing can be so good that it cannot be improved" also applies to the Codex, the two authors have attempted to optimise the few weak spots of the Codex. Joerg Luy sees the task of the Codex in surpassing the animal protection law in two respects: on the one hand regarding moral aspects that cannot be regulated (e.g. respect for the "intrinsic value" of the animal, which is greater than its "utilitarian value") and on the other hand in cases where the law does not live up to its own goals (e.g. regarding the inconsistent regulation on causing "longer term or repeated grave pain or suffering").

  1. In situ investigation of ion-induced dewetting of a thin iron-oxide film on silicon by high resolution scanning electron microscopy

    SciTech Connect

    Amirthapandian, S.; Schuchart, F.; Garmatter, D.; Bolse, W.

    2012-11-15

    Using our new in situ high resolution scanning electron microscope, which is integrated into the UNILAC ion beamline at the Helmholtzzentrum fuer Schwerionenforschung (GSI) in Darmstadt, Germany, we investigated the swift heavy ion induced dewetting of a thin iron oxide layer on Si. Besides heterogeneous hole nucleation at defects and spontaneous (homogeneous) hole nucleation, we could clearly identify a dewetting mechanism, which is similar to the spinodal dewetting observed for liquid films. Instead of being due to capillary waves, it is based on a stress induced surface instability. The latter results in the formation of a wavy surface with constant dominant wave-length and increasing amplitude during ion irradiation. Dewetting sets in as soon as the wave-troughs reach the film-substrate interface. Inspection of the hole radii and rim shapes indicates that removal of the material from the hole area occurs mainly by plastic deformation at the inner boundary and ion induced viscous flow in the peripheral zone due to surface tension.

  2. The microstructural stability and mechanical properties of two low activation martensitic steels

    SciTech Connect

    Victoria, M.; Marmy, P.; Batawi, E.; Peters, J.; Briguet, C.; Rezai-Aria, F.; Gavillet, D.

    1996-12-31

    A desirable feature of future magnetically confined fusion reactors is the prospect of producing low level radioactive waste. In order to minimize the volume of radioactive material, in particular from the first wall and blanket structures, reduced long term activation alloys are being developed. Here, a low activation composition of a martensitic 9% Cr steel has been studied, based on the DIN (Deutsches Inst. fuer Normung) 1.4914 composition (MANET) but replacing Ni, Mo and Nb by the low activation elements W, V and Ta. Two casts were produced from high purity components, in which the effects of controlled additions of Mn (0.58 and 0.055 wt. %) and N (7 and 290 wt. ppm) were studied, so that the final compositions resulted in one cast with high Mn and low N (steel A) and the other with the opposite conditions (steel B). The two steels were evaluated in terms of structural stability and mechanical properties under tensile, fatigue and fracture toughness tests. It has been found that both alloys have a DBTT below room temperature, which in the case of the steel A is 70 K below that of MANET. Although the tensile strength is somewhat below that of the parent steel, both steels have longer fatigue life.

  3. Frequency comparison involving the Romanian primary length standard RO.1 within the framework of the EUROMET Project #498

    NASA Astrophysics Data System (ADS)

    Popescu, Gheorghe

    2001-06-01

    An international frequency comparison was carried out at the Bundesamt fuer Eich- und Vermessungswessen (BEV), Vienna, within the framework of the EUROMET Project #498 from August 29 to September 5, 1999. The frequency differences obtained when the RO.1 laser from the National Institute for Laser, Plasma and Radiation Physics (NILPRP), Romania, was compared with five lasers from Austria (BEV1), Czech Republic (PLD1), France (BIPM3), Poland (GUM1) and Hungary (OMH1) are reported. Frequency differences were computed by using the matrix determinations for the group d, e, f, g. Considering the frequency differences measured for a group of three lasers compared to each other, we call the closing frequency the difference between measured and expected frequency difference (resulting from the previous two measurements). For the RO1 laser, when the BIPM3 laser was the reference laser, the closing frequencies range from +8.1 kHz to - 3.8 kHz. The relative Allan standard deviation was used to express the frequency stability and resulted 3.8 parts in 1012 for 100 s sampling time and 14000 s duration of the measurements. The averaged offset frequency relative to the BIPM4 stationary laser was 5.6 kHz and the standard deviation was 9.9 kHz.

  4. Application of Surface Micro-Discharge plasma to spacecraft component decontamination

    NASA Astrophysics Data System (ADS)

    Shimizu, Satoshi; Barczyk, Simon; Rettberg, Petra; Shimizu, Tetsuji; Klaempfl, Tobias; Zimmermann, Julia; Weber, Peter; Morfill, Gregor; Thomas, Hubertus

    2013-09-01

    In the field of extinct or extant extraterrestrial life research on other planets and moons, the prevention of biological contamination through spaceprobes is one of the most important requirements, and its detailed conditions are defined by the COSPAR planetary protection policy. Currently, a dry heat microbial reduction (DHMR) method is the only applicable way to satisfy the demand, which could, however, damage the sophisticated components like integrated circuits. In this study, cold atmospheric plasma based on the Surface Micro-Discharge technology was investigated for inactivation of different types of bacteria and endospores as an alternative method. After 90 min of plasma gas exposure, 3-6 log reductions were observed for the vegetative bacteria Escherichia coliand Deinococcus radiodurans and several types of bacterial endospores - including Bacillus atrophaeus, B. safensis, B. megaterium, B. megaterium 2c1 and B. thuringiensis E24. Furthermore, the applicability of the system for spacecraft decontamination was checked by studying the inactivation homogeneity, the temperature at the area of interest and the effects of the plasma gas exposure on different materials. The authors would like to acknowledge the financial support from Deutches Zentrum fuer Luft- und Raumfahrt (FKZ 50 JR1005).

  5. Numerical and experimental study of unsteady flow field and vibration in radial inflow turbines

    SciTech Connect

    Kreuz-Ihli, T.; Filsinger, D.; Schulz, A.; Wittig, S.

    2000-04-01

    The blades of turbocharger impellers are exposed to unsteady aerodynamic forces, which cause blade vibrations and may lead to failures. An indispensable requirement for a safe design of radial inflow turbines is a detailed knowledge of the exciting forces. Up to now, only a few investigations relating to unsteady aerodynamic forces in radial turbines have been presented. To give a detailed insight into the complex phenomena, a comprehensive research project was initiated at the Institut fuer Thermische Stroemungsmaschinen, at the University of Karlsruhe. A turbocharger test rig was installed in the high-pressure, high-temperature laboratory of the institute. The present paper gives a description of the test rig design and the measuring techniques. The flow field in a vaneless radial inflow turbine was analyzed using laser-Doppler anemometry. First results of unsteady flow field investigations in the turbine scroll and unsteady phase-resolved measurements of the flow field in the turbine rotor will be discussed. Moreover, results from finite element calculations analyzing frequencies and mode shapes are presented. As vibrations in turbines of turbochargers are assumed to be predominantly excited by unsteady aerodynamic forces, a method to predict the actual transient flow in a radial turbine utilizing the commercial Navier-Stokes solver TASCflow3d was developed. Results of the unsteady calculations are presented and comparisons with the measured unsteady flow field are made. As a major result, the excitation effect of the tongue region in a vaneless radial inflow turbine can be demonstrated.

  6. DKIST visible tunable filter control software: connecting the DKIST framework to OPC UA

    NASA Astrophysics Data System (ADS)

    Bell, Alexander; Halbgewachs, Clemens; Kentischer, Thomas J.; Schmidt, Wolfgang; von der Lühe, Oskar; Sigwarth, Michael; Fischer, Andreas

    2014-07-01

    The Visible Tunable Filter (VTF) is a narrowband tunable filter system for imaging spectroscopy and spectropolarimetry based on large-format Fabry Perot interferometers that is currently built by the Kiepenheuer Institut fuer Sonnenphysik for the Daniel K. Inouye Solar Telescope (DKIST). The control software must handle around 30 motorised drives, 3 etalons, a polarizing modulator, a helium neon laser for system calibration, temperature controllers and a multitude of sensors. The VTF is foreseen as one of the DKISTs first-light instruments and should become operational in 2019. In the design of the control software we strongly separate between the high-level part interfacing to the DKIST common services framework (CSF) and the low-level control system software which guarantees real-time performance and synchronization to precision time protocol (PTP) based observatory time. For the latter we chose a programmable logic controller (PLC) from Beckhoff Automation GmbH which supports a wide set of input and output devices as well as distributed clocks for synchronizing signals down to the sub-microsecond level. In this paper we present the design of the required control system software as well as our work on extending the DKIST CSF to use the OPC Unified Architecture (OPC UA) standard which provides a cross-platform communication standard for process control and automation as an interface between the high-level software and the real-time control system.

  7. SOFIA: Flying the Telescope

    NASA Technical Reports Server (NTRS)

    Asher, Troy; Cumming, Steve

    2012-01-01

    The Stratospheric Observatory For Infrared Astronomy (SOFIA) is an international cooperative development and operations program between the United States National Aeronautics and Space Administration (NASA) and the German Space Agency, DLR (Deutsches Zentrum fuer Luft-und Raumfahrt). SOFIA is a 2.5 meter, optical/infrared/sub-millimeter telescope mounted in a Boeing model 747SP-21 aircraft and will be used for many basic astronomical observations performed at stratospheric altitudes. It will accommodate installation of different focal plane instruments with in-flight accessibility provided by investigators selected from the international science community. The Facility operational lifetime is planned to be greater than 20 years. This presentation will present the results of developmental testing of SOFIA, including analysis, envelope expansion and the first operational mission. It will describe a brief history of open cavities in flight, how NASA designed and tested SOFIAs cavity, as well as flight test results. It will focus on how the test team achieved key milestones by systematically and efficiently reducing the number of test points to only those absolutely necessary to achieve mission requirements, thereby meeting all requirements and saving the potential loss of program funding. Finally, it will showcase examples of the observatory in action and the first operational mission of the observatory, illustrating the usefulness of the system to the international scientific community. Lessons learned on how to whittle a mountain of test points into a manageable sum will be presented at the conclusion.

  8. The ARCHES project

    NASA Astrophysics Data System (ADS)

    Motch, C.; Arches Consortium

    2014-07-01

    ARCHES (Astronomical Resource Cross-matching for High Energy Studies) is a FP7-Space funded project started in 2013 and involving the Observatoire Astronomique de Strasbourg including the CDS (France), the Leibniz-Institut fuer Astrophysik Potsdam (Germany), the University of Leicester (UK), the Universidad de Cantabria (IFCA, Spain) and the Instituto Nacional de Técnica Aeroespacial (Madrid, Spain). ARCHES aims at providing the international astronomical community with well-characterised multi-wavelength data in the form of spectral energy distributions (SEDs) for large sets of objects extracted from the 3XMM catalogue. The project develops new tools implementing fully probabilistic simultaneous cross-correlation of several catalogues. SEDs are based on an enhanced version of the 3XMM catalogue and on a careful selection of the most relevant multi-wavelength archival catalogues. In order to ensure the largest audience, SEDs will be distributed to the international community through CDS services and through the Virtual Observatory. These enhanced resources are currently tested in the framework of several science cases. An integrated cluster finder is developed at Potsdam, AGN science is studied at Leicester and IFCA while populations of Galactic X-ray sources are investigated at Strasbourg and Madrid.

  9. German Data Center for the Solar Dynamics Observatory: A model for the PLATO mission?

    NASA Astrophysics Data System (ADS)

    Burston, R.; Gizon, L.; Saidi, Y.; Solanki, S. K.

    2008-12-01

    The German Data Center for the Solar Dynamics Observatory (GDC-SDO), hosted by the Max Planck Institute for Solar System Research in Germany, will provide access to SDO data for the German solar physics community. The GDC-SDO will make available all the relevant Helioseismic and Magnetic Imager (HMI) data for helioseismology and smaller se- lected Atmospheric Imaging Assembly (AIA) data sets. This project commenced in August 2007 and is funded by the German Aerospace Center (Deutsches zentrum fuer Luft- und Raumfahrt or DLR) until December 2012. An important component of the GDC-SDO is the Data Record Management System (DRMS), developed in collaboration with the Stan- ford/Lockheed Joint Science Operations Center (JSOC). The PEGASUS workflow manage- ment system will be used to implement GDC-SDO data analysis pipelines. This makes use of the CONDOR High Throughput Computing Project for optimal job scheduling and also the GLOBUS Toolkit to enable grid technologies. Additional information about the GDC-SDO can be found at http://www.mps.mpg.de/projects/seismo/GDC1/index.html. Here, we sug- gest a similar structure and philosophy should be ideal for the PLATO mission, which looks for planetary transits and stellar oscillations and is being studied by ESA for an M-Mission slot in Cosmic Vision.

  10. Responses in the growth of the northern forest biomes to a CO{sub 2}-induced climatic change, as evaluated by the Frankfurt Biosphere Model (FBM)

    SciTech Connect

    Hager, C.; Wurth, G.; Wagner, U.; Kohlmaier, G.H.

    1996-12-31

    The Frankfurt Biosphere Model (FBM), a mechanistic, seasonal and prognostic compartment model of the terrestrial biosphere, has been developed in recent years to simulate the carbon exchange fluxes between the vegetation and the atmosphere with a spatial resolution of 0.5{degree} x 0.5{degree} on a global scale. In this contribution the authors use the FBM to assess the possible changes in the transient response of the northern forest biomes under a future 2 {times} CO{sub 2} climate. The development of these ecosystems from its initial seedling state to its climax state is simulated under different climatic conditions. In their simulations the 2 {times} CO{sub 2} climate provided by the GCM of the MPI fuer Meteorologie in Hamburg (ECHAM) is used. The differences in vegetation`s growth under contemporary and future climate can be assessed by performing two model runs with the same parameterization but with different driving climatic variables for each vegetation type and location.

  11. Experiments on Synthesis of the Heaviest Element at RIKEN

    SciTech Connect

    Morita, K.; Morimoto, K.; Kaji, D.; Haba, H.; Kanumgo, R.; Katori, K.; Kikunaga, H.; Ohnishi, T.; Suda, T.; Yoneda, A.; Yoshida, A.; Akiyama, T.; Goto, S.; Ideguchi, E.; Koura, H.; Kudo, H.; Ozawa, A.; Sueki, K.; Sato, N.; Tokanai, F.

    2007-02-26

    At the Institute of Physical and Chemical Research (RIKEN) a series of experiments studying the productions and their decays of the heaviest elements have been performed by using a gas-filled recoil ion separator GARIS. Results on the isotope of the 112th element, 277112, and on that of the 113th element, 278113, are reviewed. Tow decay chains which are assigned to be ones originating from the isotope 277112 were observed in the 208Pb(70Zn, n) reaction. Both chains consisted of four consecutive alpha decays followed by a spontaneous fission. The results provide a confirmation of the production and decay of the isotope 277112 reported by a research group at Gesellschaft fuer Schwerionenforschung (GSI), Germany, produced via the same reaction by using a velocity filter. Tow decay chains, both consisted of four consecutive alpha decays followed by a spontaneous fission, were observed also in the reaction 209Bi(70Zn, n). Those are assigned to be the convincing candidate events of the decays of the isotope of the 113th element, 278113, and its daughter nuclei, 274Rg, 270Mt, 266Bh, and 262Db.

  12. The University of Stuttgart IKE/University of Arizona student research program

    SciTech Connect

    Seale, R.L. )

    1988-01-01

    The University of Stuttgart's Institut fuer Kernenergetik und Energiesysteme (IKE) and the University of Arizona have had a joint program in which graduate students from the IKE spend 1 yr on the University of Arizona campus. This program started in 1982 largely as the result of an initiative begun by K.H. Hoecker, then director of IKE. Since 1985, Alfred Voss has been director and the program has continued without interruption. Under the program, the Deutscher Akademisher Austauschdienst, a government agency of the Federal Republic of Germany has funded scholarships for students from IKE, which provide support for 1 yr during which they attend the University of Arizona as visiting student scholars and engage in a research project under the direction of one of our faculty, which satisfies a part of the requirements for the Ingenieur-Diplom Fachrichtung Maschinenbau. The students get credit for their research from the University of Stuttgart. The topics have a broad range and include software development, artificial intelligence, radiation transport, and energy management studies.

  13. Konrad Repository Facing its Construction

    SciTech Connect

    Kunze, V.

    2008-07-01

    According to the German Atomic Energy Act the Federation is responsible for the construction and operation of installations for the safekeeping and disposal of radioactive waste. This duty was assigned to the Federal Office for Radiation Protection (Bundesamt fuer Strahlenschutz - BfS). In 1982, the Federal Institute of Physics and Metrology (Physikalisch Technische Bundesanstalt - PTB) as the precursor of BfS applied for a license for the disposal of radioactive waste with negligible heat generation in the Konrad iron ore mine near Salzgitter at the Ministry for Environment of Lower Saxony. After 25 years of plan approval procedure and subsequent lawsuits the license is now valid and Konrad is waiting for construction. Facing this challenge BfS has established a project team to supervise the in-house and external activities to be done. It is intended to construct the Konrad repository within a preparation period of two years and a subsequent erection phase of four years. Thus, Konrad is planned to come into operation in 2013. In this paper the development of the plan approval procedure, the technical design of the planned repository, especially with regard to safety-related aspects, and the planning for the construction will be discussed. (authors)

  14. An approach for the limitation of fissile material resulting from criticality safety analysis of a waste repository

    SciTech Connect

    Berg, H.P. ); Gmal, B. )

    1993-01-01

    The Bundesamt fuer Strahlenschutz (BfS), Germany's Federal Office of Radiation Protection, intends to dispose of non-heat-generating radioactive waste, which may contain residual quantities of fissile materials like U 235 or Pu 239 in solid form, in the planned German Konrad repository. Within the framework of a comprehensive safety analysis, criticality safety for both the operational phase and the post-operational phase of the repository has been investigated. The performed analysis and the investigated scenarios as well as the calculation methods are described. As a result of the criticality safety considerations, limitations of fissionable materials are derived. These limitations restrict on the one hand the admissible mass concentration of fissile materials in the waste form and--on the other hand--the admissible mass of these materials in the cross section of an emplacement room, leading at the end to admissible masses per waste package. The mass limitations are determined separately for four radionuclides. In practice, a mixture of these radionuclides in a waste package has to be taken into account. Therefore, a summation criterion has been derived in order to ensure a high flexibility for the conditioning of the waste. This flexibility option does not result in a lower safety level of the repository.

  15. The first educational interferometer in Mexico (FEYMANS): A novel project

    NASA Astrophysics Data System (ADS)

    Villicana Pedraza, Ilhuiyolitzin; Guesten, Rolf; Saucedo Morales, Julio Cesar; Carreto, Francisco; Valdes Estrada, Erik; Wendolyn Blanco Cardenas, Monica; Rodríguez Garza, Carolina B.; Pech Castillo, Gerardo A.; Ángel Vaquerizo, Juan

    2016-07-01

    An interferometer is composed of several radio telescopes (dishes) separated by a defined distance and used in synchrony. This kind of array produces a superior angular resolution, better than the resolution achieved by a single dish of the same combined area. In this work we propose the First Educational Youth Mexican Array North South, FEYMANS. It consists of an educational interferometer with initially four dishes. This array harvests Mexico's geography by locating each dish at the periphery of the country; creating new scientific links of provincial populations with the capital. The FEYMANS project focus in high school students and their projects on physics, chemistry and astronomy as a final project. Also, it can be used for bachelor theses. The initial and central dish-node is planed to be in Mexico City. After its construction, the efforts will focus to build subsequent nodes, on the Northwest region, Northeast, or Southeast. Region Northwest will give service to Baja California, Sonora and Chihuahua states. Region Northeast will cover Coahuila, Nuevo Leon and Tamaulipas. Finally, region Southeast will give access to Yucatan, Quintana Roo, Campeche, Tabasco and Chiapas. This project has been conceived by young professional astronomers and Mexican experts that will operate each node. Also, we have the technical support of the "Max Planck Institute fuer Radioastronomy in Bonn Germany" and the educational model of the "PARTNeR" project in Spain. This interferometer will be financed by Mexico's Federal Congress and by Mexico City's Legislative Assembly (ALDF).

  16. Simulation of DKIST solar adaptive optics system

    NASA Astrophysics Data System (ADS)

    Marino, Jose; Carlisle, Elizabeth; Schmidt, Dirk

    2016-07-01

    Solar adaptive optics (AO) simulations are a valuable tool to guide the design and optimization process of current and future solar AO and multi-conjugate AO (MCAO) systems. Solar AO and MCAO systems rely on extended object cross-correlating Shack-Hartmann wavefront sensors to measure the wavefront. Accurate solar AO simulations require computationally intensive operations, which have until recently presented a prohibitive computational cost. We present an update on the status of a solar AO and MCAO simulation tool being developed at the National Solar Observatory. The simulation tool is a multi-threaded application written in the C++ language that takes advantage of current large multi-core CPU computer systems and fast ethernet connections to provide accurate full simulation of solar AO and MCAO systems. It interfaces with KAOS, a state of the art solar AO control software developed by the Kiepenheuer-Institut fuer Sonnenphysik, that provides reliable AO control. We report on the latest results produced by the solar AO simulation tool.

  17. Proton microscopy at GSI and FAIR

    SciTech Connect

    Merrill, Frank E; Mariam, Fesseha G; Golubev, A A; Turtikov, V I; Varentsov, D

    2009-01-01

    Proton radiography was invented in the 1990's at Los Alamos National Laboratory (LANL) as a diagnostic to study dynamic material properties under extreme pressures, strain and strain rate. Since this time hundreds of dynamic proton radiography experiments have been performed at LANL and facilities have been commissioned at the Institute for Theoretical and Experimental Physics (ITEP) in Russia for similar applications in dynamic material studies. Recently an international collaboration was formed to develop a new proton radiography capability for the study of dynamic material properties at the Facility for Anti-proton and Ion Research (FAIR) located at Gesellschaft fuer Schwerionenforschung (GSI) in Darmstadt, Germany. This new Proton microscope for FAIR (PRIOR) will provide radiographic imaging of dynamic systems with unprecedented spatial, temporal and density resolution, resulting in a window for understanding dynamic material properties at new length scales. These dynamic experiments will be driven with many energy sources including heavy ions, high explosives and lasers. The design of the proton microscope and expected radiographic performance is presented.

  18. EARLY SCIENCE WITH SOFIA, THE STRATOSPHERIC OBSERVATORY FOR INFRARED ASTRONOMY

    SciTech Connect

    Young, E. T.; Becklin, E. E.; De Buizer, J. M.; Andersson, B.-G.; Casey, S. C.; Helton, L. A.; Marcum, P. M.; Roellig, T. L.; Temi, P.; Herter, T. L.; Guesten, R.; Dunham, E. W.; Backman, D.; Burgdorf, M.; Caroff, L. J.; Erickson, E. F.; Davidson, J. A.; Gehrz, R. D.; Harper, D. A.; Harvey, P. M.; and others

    2012-04-20

    The Stratospheric Observatory For Infrared Astronomy (SOFIA) is an airborne observatory consisting of a specially modified Boeing 747SP with a 2.7 m telescope, flying at altitudes as high as 13.7 km (45,000 ft). Designed to observe at wavelengths from 0.3 {mu}m to 1.6 mm, SOFIA operates above 99.8% of the water vapor that obscures much of the infrared and submillimeter. SOFIA has seven science instruments under development, including an occultation photometer, near-, mid-, and far-infrared cameras, infrared spectrometers, and heterodyne receivers. SOFIA, a joint project between NASA and the German Aerospace Center Deutsches Zentrum fuer Luft und-Raumfahrt, began initial science flights in 2010 December, and has conducted 30 science flights in the subsequent year. During this early science period three instruments have flown: the mid-infrared camera FORCAST, the heterodyne spectrometer GREAT, and the occultation photometer HIPO. This Letter provides an overview of the observatory and its early performance.

  19. 17th International Microgravity Measurements Group Meeting

    NASA Technical Reports Server (NTRS)

    DeLombard, Richard

    1998-01-01

    The Seventeenth International Microgravity Measurements Group (MGMG) meeting was held 24-26 March 1998 at the Ohio Aerospace Institute (OAI) in Brook Park, Ohio. This meeting focused on the transition of microgravity science research from the Shuttle, Mir, and free flyers to the International Space Station. The MGMG series of meetings are conducted by the Principal Investigator Microgravity Services project of the Microgravity Science Division at the NASA Lewis Research Center. The MGMG meetings provide a forum for the exchange of information and ideas about the microgravity environment and microgravity acceleration research in the Microgravity Research Program. The meeting had participation from investigators in all areas of microgravity research. The attendees included representatives from: NASA centers; National Space Development Agency of Japan; European Space Agency; Daimler Benz Aerospace AG; Deutsches Zentrum fuer Luft- und Raumfahrt; Centre National d'Etudes Spatiales; Canadian Space Agency, national research institutions; Universities in U.S., Italy, Germany, and Russia; and commercial companies in the U.S. and Russia. Several agencies presented summaries of the measurement, analysis, and characterization of the microgravity environment of the Shuttle, Mir, and sounding rockets over the past fifteen years. This extensive effort has laid a foundation for pursuing a similar course during future microgravity science experiment operations on the ISS. Future activities of microgravity environment characterization were discussed by several agencies who plan to operate on the ISS.

  20. Co-pyrolysis of coal/biomass and coal/sewage sludge mixtures

    SciTech Connect

    Storm, C.; Ruediger, H.; Spliethoff, H.; Hein, K.R.G.

    1999-01-01

    Biomass and sewage sludge are attracting increasing interest in power plant technology as a source of carbon-dioxide-neutral fuels. A new way to reduce the consumption of fossil fuels could be the co-combustion or co-gasification of coal and biomass or coal and sewage sludge. In both cases, pyrolysis is the first step in the technical process. In order to obtain detailed information about the pyrolysis of coal/biomass and coal/sewage sludge mixtures as well as unblended fuels, the Institut fuer Verfahrenstechnik and Dampfkesselwesen (IVD) at the University of Stuttgart has carried out investigations using an electrically heated entrained flow reactor. The test runs provided information about fuel conversion efficiency, pyrolysis gas and tar yield, and composition of pyrolysis gas and tar. Besides gas and tar analysis investigations regarding the path of trace elements, like heavy metals, alkali, chlorine and nitrogen components, during the pyrolysis process varying different parameters have been carried out. The fuel nitrogen distribution between pyrolysis gas, tar, and char has been analyzed, as well as the ash composition, and, thus, the release of mineral components during pyrolysis.

  1. Castor-1C spent fuel storage cask decay heat, heat transfer, and shielding analyses

    SciTech Connect

    Rector, D.R.; McCann, R.A.; Jenquin, U.P.; Heeb, C.M.; Creer, J.M.; Wheeler, C.L.

    1986-12-01

    This report documents the decay heat, heat transfer, and shielding analyses of the Gesellschaft fuer Nuklear Services (GNS) CASTOR-1C cask used in a spent fuel storage demonstration performed at Preussen Elektra's Wurgassen nuclear power plant. The demonstration was performed between March 1982 and January 1984, and resulted in cask and fuel temperature data and cask exterior surface gamma-ray and neutron radiation dose rate measurements. The purpose of the analyses reported here was to evaluate decay heat, heat transfer, and shielding computer codes. The analyses consisted of (1) performing pre-look predictions (predictions performed before the analysts were provided the test data), (2) comparing ORIGEN2 (decay heat), COBRA-SFS and HYDRA (heat transfer), and QAD and DOT (shielding) results to data, and (3) performing post-test analyses if appropriate. Even though two heat transfer codes were used to predict CASTOR-1C cask test data, no attempt was made to compare the two codes. The codes are being evaluated with other test data (single-assembly data and other cask data), and to compare the codes based on one set of data may be premature and lead to erroneous conclusions.

  2. Construction and manufacturing of a microgearhead with 1.9-mm outer diameter for universal application

    NASA Astrophysics Data System (ADS)

    Thuerigen, Christian; Beckord, Ulrich; Bessey, Reiner

    1999-03-01

    Many new applications in medicine, telecommunication, automation systems etc. require powerful microdrives. Speeds up to 100.000 rpm and output torques in the (mu) Nm-range are typical characteristics of electromagnetic micromotors with diameters of a few millimeters. To accomplish a powerful microdrive, these micromotors have to be combined with micro gearheads of the same outer diameter. For such a micro gearhead with toothed wheels manufactured by use of the LIGA process a multi-stage planetary gear has many advantages. Many stages with different gear ratios can be combined to achieve a great number of different transmission, but manufacturing tolerances and a clearance for assembly must be respected. Therefore besides the selection of a reliable gearhead type and a suitable manufacturing process the optimization of the tooth profile is the key to the implementation of powerful micro gear systems with high output torques and efficiencies. The involute profile is the most suitable toothing, but many calculations and simulations are required to find the right modulus, total depth of teeth, profile offset etc. In a joint project Dr. Fritz Faulhaber GmbH and Co. KG and the Institut fuer Mikrotechnik Mainz GmbH developed a powerful microdevice with an outer diameter of only 1.9 mm.

  3. Microscopy of semiconducting materials

    NASA Astrophysics Data System (ADS)

    Pennycook, S. J.

    1991-04-01

    The purpose of the trip was to present an invited talk at the 7th Oxford Conference on Microscopy of Semiconducting Materials entitled, High-Resolution Z-Contrast Imaging of Heterostructures and Superlattices, (Oxford, United Kingdom) and to visit VG Microscopes, East Grinstead, for discussions on the progress of the Oak Ridge National Laboratory (ORNL) 300-kV high-resolution scanning transmission electron microscope (STEM), which is currently on order. The traveler also visited three other institutions with 100-kV STEMs that either have or intend to purchase the necessary modifications to provide Z-contrast capability similar to that of the existing ORNL machine. Specifically, Max-Planck Institut fuer Metallforschung (Stuttgart, Germany); Cambridge University, Department of Materials Science and Metallurgy (Cambridge, United Kingdom); and Cavendish Laboratory, Cambridge University (Cambridge, United Kingdom) were visited. In addition, discussions were held with C. Humphreys on the possibility of obtaining joint funding for collaborative research involving electron beam writing and Z-contrast imaging in the Cambridge and Oak Ridge STEMs, respectively.

  4. Motor performance is better than normal in preschool children with cystic fibrosis.

    PubMed

    Gruber, Wolfgang; Orenstein, David M; Paul, Karl; Hüls, Gerd; Braumann, Klaus M

    2010-06-01

    The aim of the present study was to assess the motor performance in preschool children with a reliable and valid test battery developed to identify motor dysfunction and normal motor development in children aged from 4 to 6 years. Several aspects of motor performance were examined in 29 preschool children with cystic fibrosis (CF) age range 4-6 years (mean 5.2 +/- 0.8 years), FEV(1) 97.2 +/- 15.3pred and compared to with 22 healthy children of the same age 5.5 +/- 0.8 years. All children performed the "Motoriktest fuer 4-6jaehrige Kinder" (MOT) assessing seven different aspects of motor performance. Compared to healthy children, test score "Motor Quotient" (MQ) as the mean of all test items was significantly higher (P < 0.05) in children with CF (108.1 +/- 16 vs. 93.5 +/- 17.9). In both groups, the MQ can be classified as normal. Children with CF scored higher in MOT subtests "Agility and Coordination" (P < 0.05) and "Balance" (P < 0.01) than healthy children but not in the other subtests. We speculate that chest physiotherapy in preschool children with CF may have an effect on motor performance in general and in some aspects of motor performance.

  5. Photoproduction and Photodisintigration Processes of the Deuteron

    NASA Astrophysics Data System (ADS)

    Gohs, Jessica; Briscoe, William; Hornidge, Dave; Moores, Korwin; McDermit, Kevin; Bulmer, Kris; Patterson, Steven; Starotsin, Sasha; Rost, Mattias; Downie, Eve

    2004-10-01

    The Mainz Mictrotron (MAMI) is a continuous wave electron accelerator located at the Institut fuer Kernphysik in Mainz, Germany. It is the best tagged photon facility below 855 MeV and has extremely high energy resolution. TAPS, or Two Arm Photon Spectrometer, is a high resolution photon detection system that has been used at MAMI for the past fifteen years. In 2002 the (SLAC) Crystal Ball multiphoton spectrometer was moved from Brookhaven National Laboratory to Mainz due to the excellent facilities at MAMI. The combination of TAPS and the Crystal Ball form a truly 4p detection system for protons and neutrons. A photon beam with energies between 400 and 855 MeV has been used with a liquid deuterium target to investigate several photoproduction and photodisintigration processes. Among these are coherent p0 production on the deuteron itself, p0 production off the individual quasi-free nucleons, and the photodisintigration of the deuteron into a proton and a neutron. While each of these processes have physics interest, the latter can also be used to calibrate the detection efficiency of the Crystal Ball and TAPS for neutrons. We plan to report on the preliminary physics and calibration results from the first measurements made with the deuterium target.

  6. Fast voxel-level dosimetry for (177)Lu labelled peptide treatments.

    PubMed

    Hippeläinen, E; Tenhunen, M; Sohlberg, A

    2015-09-07

    In peptide receptor radionuclide therapy (PRRT), voxel-level radiation absorbed dose calculations can be performed using several different methods. Each method has it strengths and weaknesses; however, Monte Carlo (MC) simulation is presently considered the most accurate method at providing absorbed dose distributions. Unfortunately MC simulation is time-consuming and often impractical to carry out in a clinical practice. In this work, a fast semi-Monte Carlo (sMC) absorbed dose calculation method for (177)Lu PRRT dosimetry is presented. The sMC method is based on a local electron absorption assumption and fast photon MC simulations. The sMC method is compared against full MC simulation code built on PENELOPE (vxlPen) using digital phantoms to assess the accuracy of these assumptions.Due to the local electron absorption assumption of sMC, the potential errors in cross-fire dose from electrons and photons emitted by (177)Lu were first evaluated using an ellipsoidal kidney model by comparing vxlPen and sMC. The photon cross-fire dose from background to kidney and kidney to background with varying kidney-to-background activity concentration ratios were calculated. In addition, kidney to kidney photon and electron cross-dose with different kidney to kidney distances were studied. Second, extended cardiac-torso (XCAT) phantoms were created with liver lesions and with realistic activity distributions and tissue densities. The XCAT phantoms were used to simulate SPECT projections and 3D activity distribution images were reconstructed using an OSEM algorithm. Image-based dose rate distributions were calculated using vxlPen and sMC. Total doses and dose rate volume histograms (DrVH) produced by the two methods were compared.The photon cross-fire dose from the kidney increased the background's absorbed dose by 5% or more up to 5.8 cm distance with 20 : 1 kidney to background activity concentration ratio. On the other hand, the photon cross-fire dose from the background to

  7. Fast voxel-level dosimetry for 177Lu labelled peptide treatments

    NASA Astrophysics Data System (ADS)

    Hippeläinen, E.; Tenhunen, M.; Sohlberg, A.

    2015-09-01

    In peptide receptor radionuclide therapy (PRRT), voxel-level radiation absorbed dose calculations can be performed using several different methods. Each method has it strengths and weaknesses; however, Monte Carlo (MC) simulation is presently considered the most accurate method at providing absorbed dose distributions. Unfortunately MC simulation is time-consuming and often impractical to carry out in a clinical practice. In this work, a fast semi-Monte Carlo (sMC) absorbed dose calculation method for 177Lu PRRT dosimetry is presented. The sMC method is based on a local electron absorption assumption and fast photon MC simulations. The sMC method is compared against full MC simulation code built on PENELOPE (vxlPen) using digital phantoms to assess the accuracy of these assumptions. Due to the local electron absorption assumption of sMC, the potential errors in cross-fire dose from electrons and photons emitted by 177Lu were first evaluated using an ellipsoidal kidney model by comparing vxlPen and sMC. The photon cross-fire dose from background to kidney and kidney to background with varying kidney-to-background activity concentration ratios were calculated. In addition, kidney to kidney photon and electron cross-dose with different kidney to kidney distances were studied. Second, extended cardiac-torso (XCAT) phantoms were created with liver lesions and with realistic activity distributions and tissue densities. The XCAT phantoms were used to simulate SPECT projections and 3D activity distribution images were reconstructed using an OSEM algorithm. Image-based dose rate distributions were calculated using vxlPen and sMC. Total doses and dose rate volume histograms (DrVH) produced by the two methods were compared. The photon cross-fire dose from the kidney increased the background’s absorbed dose by 5% or more up to 5.8 cm distance with 20 : 1 kidney to background activity concentration ratio. On the other hand, the photon cross-fire dose from the background to

  8. Monte Carlo simulation of TrueBeam flattening-filter-free beams using Varian phase-space files: Comparison with experimental data

    SciTech Connect

    Belosi, Maria F.; Fogliata, Antonella E-mail: afc@iosi.ch; Cozzi, Luca; Clivio, Alessandro; Nicolini, Giorgia; Vanetti, Eugenio; Rodriguez, Miguel; Sempau, Josep; Krauss, Harald; Khamphan, Catherine; Fenoglietto, Pascal; Puxeu, Josep; Fedele, David; Mancosu, Pietro; Brualla, Lorenzo

    2014-05-15

    Purpose: Phase-space files for Monte Carlo simulation of the Varian TrueBeam beams have been made available by Varian. The aim of this study is to evaluate the accuracy of the distributed phase-space files for flattening filter free (FFF) beams, against experimental measurements from ten TrueBeam Linacs. Methods: The phase-space files have been used as input in PRIMO, a recently released Monte Carlo program based on thePENELOPE code. Simulations of 6 and 10 MV FFF were computed in a virtual water phantom for field sizes 3 × 3, 6 × 6, and 10 × 10 cm{sup 2} using 1 × 1 × 1 mm{sup 3} voxels and for 20 × 20 and 40 × 40 cm{sup 2} with 2 × 2 × 2 mm{sup 3} voxels. The particles contained in the initial phase-space files were transported downstream to a plane just above the phantom surface, where a subsequent phase-space file was tallied. Particles were transported downstream this second phase-space file to the water phantom. Experimental data consisted of depth doses and profiles at five different depths acquired at SSD = 100 cm (seven datasets) and SSD = 90 cm (three datasets). Simulations and experimental data were compared in terms of dose difference. Gamma analysis was also performed using 1%, 1 mm and 2%, 2 mm criteria of dose-difference and distance-to-agreement, respectively. Additionally, the parameters characterizing the dose profiles of unflattened beams were evaluated for both measurements and simulations. Results: Analysis of depth dose curves showed that dose differences increased with increasing field size and depth; this effect might be partly motivated due to an underestimation of the primary beam energy used to compute the phase-space files. Average dose differences reached 1% for the largest field size. Lateral profiles presented dose differences well within 1% for fields up to 20 × 20 cm{sup 2}, while the discrepancy increased toward 2% in the 40 × 40 cm{sup 2} cases. Gamma analysis resulted in an agreement of 100% when a 2%, 2 mm criterion

  9. A generic high-dose rate {sup 192}Ir brachytherapy source for evaluation of model-based dose calculations beyond the TG-43 formalism

    SciTech Connect

    Ballester, Facundo; Carlsson Tedgren, Åsa; Granero, Domingo; Haworth, Annette; Mourtada, Firas; Fonseca, Gabriel Paiva; Rivard, Mark J.; Siebert, Frank-André; Sloboda, Ron S.; and others

    2015-06-15

    Purpose: In order to facilitate a smooth transition for brachytherapy dose calculations from the American Association of Physicists in Medicine (AAPM) Task Group No. 43 (TG-43) formalism to model-based dose calculation algorithms (MBDCAs), treatment planning systems (TPSs) using a MBDCA require a set of well-defined test case plans characterized by Monte Carlo (MC) methods. This also permits direct dose comparison to TG-43 reference data. Such test case plans should be made available for use in the software commissioning process performed by clinical end users. To this end, a hypothetical, generic high-dose rate (HDR) {sup 192}Ir source and a virtual water phantom were designed, which can be imported into a TPS. Methods: A hypothetical, generic HDR {sup 192}Ir source was designed based on commercially available sources as well as a virtual, cubic water phantom that can be imported into any TPS in DICOM format. The dose distribution of the generic {sup 192}Ir source when placed at the center of the cubic phantom, and away from the center under altered scatter conditions, was evaluated using two commercial MBDCAs [Oncentra{sup ®} Brachy with advanced collapsed-cone engine (ACE) and BrachyVision ACUROS{sup TM}]. Dose comparisons were performed using state-of-the-art MC codes for radiation transport, including ALGEBRA, BrachyDose, GEANT4, MCNP5, MCNP6, and PENELOPE2008. The methodologies adhered to recommendations in the AAPM TG-229 report on high-energy brachytherapy source dosimetry. TG-43 dosimetry parameters, an along-away dose-rate table, and primary and scatter separated (PSS) data were obtained. The virtual water phantom of (201){sup 3} voxels (1 mm sides) was used to evaluate the calculated dose distributions. Two test case plans involving a single position of the generic HDR {sup 192}Ir source in this phantom were prepared: (i) source centered in the phantom and (ii) source displaced 7 cm laterally from the center. Datasets were independently produced by

  10. A systematic catalogue of butterflies of the former Soviet Union (Armenia, Azerbaijan, Belarus, Estonia, Georgia, Kyrgyzstan, Kazakhstan, Latvia, Lituania, Moldova, Russia, Tajikistan, Turkmenistan, Ukraine, Uzbekistan) with special account to their type specimens (Lepidoptera: Hesperioidea, Papilionoidea).

    PubMed

    Korb, Stanislav K; Bolshakov, Lavr V

    2016-09-01

    A catalogue of butterflies of Russia and adjacent countries is given, with special account to the name-bearing types depository. This catalogue contains data about 86 species (3 of them are questionable) of Hesperiidae (22 genera); 47 species of Papilionidae (14 genera); 89 species of Pieridae (5 of them are questionable)  (15 genera); 1 species (1 genus) of Libytheinae(dae); 2 species of Danainae(dae) (2 genera); 160 species of Nymphalinae(dae) (1 of them is questionable) (23 genera); 259 species of Satyrinae(dae) (14 of them are questionable, mainly from genera Oeneis and Pseudochazara) (34 genera); 3 species of Riodinidae (2 genera); 318 species of Lycaenidae (11 of them are questionable, mainly from genera Neolycaena and Plebeius) (57 genera). In total: 965 species of butterflies, 174 genera, by countries: Armenia-244, Azerbaijan-225, Belarus-107, Estonia-113, Georgia-211, Kyrgyzstan-316, Kazakhstan-344, Latvia-115, Lituania-126, Moldova-87, Russia-522, Tajikistan-295, Turkmenistan-159, Ukraine-192, Uzbekistan-241. Detailed distribution and subspecific structure (if present) for every species is provided. Lectotypes of the following species-group taxa are designated: Hesperia poggei Lederer, 1858, Parnassius felderi Bremer, 1861, P. eversmanni Eversmann, 1851, P. boedromius Püngeler, 1901, Limenitis moltrechti Kardakov, 1928, L. sydyi Kindermann, 1853, L. amphyssa Ménétriès, 1859, L. doerriesi Staudinger, 1892, L. helmanni duplicata Staudinger, 1892, L. homeyeri Tancré, 1881, Argynnis penelope Staudinger, 1891, A. thore borealis Staudinger, 1861, Vanessa io geisha Stichel, [1908], Melitaea maturna staudingeri Wnukowsky, 1929 (=uralensis Staudinger, 1871), M. didymina Staudinger, 1895, Papilio fascelis Esper, 1783, Thecla quercivora Staudinger, 1887, Lycaena orion var. ornata Staudinger, 1892. The following nomenclatural acts are established: Neolycaena submontana baitenovi (Zhdanko, 2011), comb. et stat.n. The following new synonymy is provided: Hesperia

  11. Monte Carlo study for designing a dedicated “D”-shaped collimator used in the external beam radiotherapy of retinoblastoma patients

    SciTech Connect

    Mayorga, P. A.; Brualla, L.; Sauerwein, W.; Lallena, A. M.

    2014-01-15

    Purpose: Retinoblastoma is the most common intraocular malignancy in the early childhood. Patients treated with external beam radiotherapy respond very well to the treatment. However, owing to the genotype of children suffering hereditary retinoblastoma, the risk of secondary radio-induced malignancies is high. The University Hospital of Essen has successfully treated these patients on a daily basis during nearly 30 years using a dedicated “D”-shaped collimator. The use of this collimator that delivers a highly conformed small radiation field, gives very good results in the control of the primary tumor as well as in preserving visual function, while it avoids the devastating side effects of deformation of midface bones. The purpose of the present paper is to propose a modified version of the “D”-shaped collimator that reduces even further the irradiation field with the scope to reduce as well the risk of radio-induced secondary malignancies. Concurrently, the new dedicated “D”-shaped collimator must be easier to build and at the same time produces dose distributions that only differ on the field size with respect to the dose distributions obtained by the current collimator in use. The scope of the former requirement is to facilitate the employment of the authors' irradiation technique both at the authors' and at other hospitals. The fulfillment of the latter allows the authors to continue using the clinical experience gained in more than 30 years. Methods: The Monte Carlo codePENELOPE was used to study the effect that the different structural elements of the dedicated “D”-shaped collimator have on the absorbed dose distribution. To perform this study, the radiation transport through a Varian Clinac 2100 C/D operating at 6 MV was simulated in order to tally phase-space files which were then used as radiation sources to simulate the considered collimators and the subsequent dose distributions. With the knowledge gained in that study, a new, simpler,

  12. A BrachyPhantom for verification of dose calculation of HDR brachytherapy planning system

    SciTech Connect

    Austerlitz, C.; Campos, C. A. T.

    2013-11-15

    Purpose: To develop a calibration phantom for {sup 192}Ir high dose rate (HDR) brachytherapy units that renders possible the direct measurement of absorbed dose to water and verification of treatment planning system.Methods: A phantom, herein designated BrachyPhantom, consists of a Solid Water™ 8-cm high cylinder with a diameter of 14 cm cavity in its axis that allows the positioning of an A1SL ionization chamber with its reference measuring point at the midheight of the cylinder's axis. Inside the BrachyPhantom, at a 3-cm radial distance from the chamber's reference measuring point, there is a circular channel connected to a cylindrical-guide cavity that allows the insertion of a 6-French flexible plastic catheter from the BrachyPhantom surface. The PENELOPE Monte Carlo code was used to calculate a factor, P{sub sw}{sup lw}, to correct the reading of the ionization chamber to a full scatter condition in liquid water. The verification of dose calculation of a HDR brachytherapy treatment planning system was performed by inserting a catheter with a dummy source in the phantom channel and scanning it with a CT. The CT scan was then transferred to the HDR computer program in which a multiple treatment plan was programmed to deliver a total dose of 150 cGy to the ionization chamber. The instrument reading was then converted to absorbed dose to water using the N{sub gas} formalism and the P{sub sw}{sup lw} factor. Likewise, the absorbed dose to water was calculated using the source strength, S{sub k}, values provided by 15 institutions visited in this work.Results: A value of 1.020 (0.09%, k= 2) was found for P{sub sw}{sup lw}. The expanded uncertainty in the absorbed dose assessed with the BrachyPhantom was found to be 2.12% (k= 1). To an associated S{sub k} of 27.8 cGy m{sup 2} h{sup −1}, the total irradiation time to deliver 150 cGy to the ionization chamber point of reference was 161.0 s. The deviation between the absorbed doses to water assessed with the Brachy

  13. Physical characterization of single convergent beam device for teletherapy: theoretical and Monte Carlo approach.

    PubMed

    Figueroa, R G; Valente, M

    2015-09-21

    The main purpose of this work is to determine the feasibility and physical characteristics of a new teletherapy device of radiation therapy based on the application of a convergent x-ray beam of energies like those used in radiotherapy providing highly concentrated dose delivery to the target. We have denominated it Convergent Beam Radio Therapy (CBRT). Analytical methods are developed first in order to determine the dosimetry characteristic of an ideal convergent photon beam in a hypothetical water phantom. Then, using the PENELOPE Monte Carlo code, a similar convergent beam that is applied to the water phantom is compared with that of the analytical method. The CBRT device (Converay(®)) is designed to adapt to the head of LINACs. The converging beam photon effect is achieved thanks to the perpendicular impact of LINAC electrons on a large thin spherical cap target where Bremsstrahlung is generated (high-energy x-rays). This way, the electrons impact upon various points of the cap (CBRT condition), aimed at the focal point. With the X radiation (Bremsstrahlung) directed forward, a system of movable collimators emits many beams from the output that make a virtually definitive convergent beam. Other Monte Carlo simulations are performed using realistic conditions. The simulations are performed for a thin target in the shape of a large, thin, spherical cap, with an r radius of around 10-30 cm and a curvature radius of approximately 70 to 100 cm, and a cubed water phantom centered in the focal point of the cap. All the interaction mechanisms of the Bremsstrahlung radiation with the phantom are taken into consideration for different energies and cap thicknesses. Also, the magnitudes of the electric and/or magnetic fields, which are necessary to divert clinical-use electron beams (0.1 to 20 MeV), are determined using electromagnetism equations with relativistic corrections. This way the above-mentioned beam is manipulated and guided for its perpendicular impact

  14. Modeling a Hypothetical {sup 170}Tm Source for Brachytherapy Applications

    SciTech Connect

    Enger, Shirin A.; D'Amours, Michel; Beaulieu, Luc

    2011-10-15

    Purpose: To perform absorbed dose calculations based on Monte Carlo simulations for a hypothetical {sup 170}Tm source and to investigate the influence of encapsulating material on the energy spectrum of the emitted electrons and photons. Methods: GEANT4 Monte Carlo code version 9.2 patch 2 was used to simulate the decay process of {sup 170}Tm and to calculate the absorbed dose distribution using the GEANT4 Penelope physics models. A hypothetical {sup 170}Tm source based on the Flexisource brachytherapy design with the active core set as a pure thulium cylinder (length 3.5 mm and diameter 0.6 mm) and different cylindrical source encapsulations (length 5 mm and thickness 0.125 mm) constructed of titanium, stainless-steel, gold, or platinum were simulated. The radial dose function for the line source approximation was calculated following the TG-43U1 formalism for the stainless-steel encapsulation. Results: For the titanium and stainless-steel encapsulation, 94% of the total bremsstrahlung is produced inside the core, 4.8 and 5.5% in titanium and stainless-steel capsules, respectively, and less than 1% in water. For the gold capsule, 85% is produced inside the core, 14.2% inside the gold capsule, and a negligible amount (<1%) in water. Platinum encapsulation resulted in bremsstrahlung effects similar to those with the gold encapsulation. The range of the beta particles decreases by 1.1 mm with the stainless-steel encapsulation compared to the bare source but the tissue will still receive dose from the beta particles several millimeters from the source capsule. The gold and platinum capsules not only absorb most of the electrons but also attenuate low energy photons. The mean energy of the photons escaping the core and the stainless-steel capsule is 113 keV while for the gold and platinum the mean energy is 160 keV and 165 keV, respectively. Conclusions: A {sup 170}Tm source is primarily a bremsstrahlung source, with the majority of bremsstrahlung photons being

  15. Monte Carlo-based treatment planning system calculation engine for microbeam radiation therapy

    SciTech Connect

    Martinez-Rovira, I.; Sempau, J.; Prezado, Y.

    2012-05-15

    Purpose: Microbeam radiation therapy (MRT) is a synchrotron radiotherapy technique that explores the limits of the dose-volume effect. Preclinical studies have shown that MRT irradiations (arrays of 25-75-{mu}m-wide microbeams spaced by 200-400 {mu}m) are able to eradicate highly aggressive animal tumor models while healthy tissue is preserved. These promising results have provided the basis for the forthcoming clinical trials at the ID17 Biomedical Beamline of the European Synchrotron Radiation Facility (ESRF). The first step includes irradiation of pets (cats and dogs) as a milestone before treatment of human patients. Within this context, accurate dose calculations are required. The distinct features of both beam generation and irradiation geometry in MRT with respect to conventional techniques require the development of a specific MRT treatment planning system (TPS). In particular, a Monte Carlo (MC)-based calculation engine for the MRT TPS has been developed in this work. Experimental verification in heterogeneous phantoms and optimization of the computation time have also been performed. Methods: The penelope/penEasy MC code was used to compute dose distributions from a realistic beam source model. Experimental verification was carried out by means of radiochromic films placed within heterogeneous slab-phantoms. Once validation was completed, dose computations in a virtual model of a patient, reconstructed from computed tomography (CT) images, were performed. To this end, decoupling of the CT image voxel grid (a few cubic millimeter volume) to the dose bin grid, which has micrometer dimensions in the transversal direction of the microbeams, was performed. Optimization of the simulation parameters, the use of variance-reduction (VR) techniques, and other methods, such as the parallelization of the simulations, were applied in order to speed up the dose computation. Results: Good agreement between MC simulations and experimental results was achieved, even at

  16. A package of Linux scripts for the parallelization of Monte Carlo simulations

    NASA Astrophysics Data System (ADS)

    Badal, Andreu; Sempau, Josep

    2006-09-01

    Despite the fact that fast computers are nowadays available at low cost, there are many situations where obtaining a reasonably low statistical uncertainty in a Monte Carlo (MC) simulation involves a prohibitively large amount of time. This limitation can be overcome by having recourse to parallel computing. Most tools designed to facilitate this approach require modification of the source code and the installation of additional software, which may be inconvenient for some users. We present a set of tools, named clonEasy, that implement a parallelization scheme of a MC simulation that is free from these drawbacks. In clonEasy, which is designed to run under Linux, a set of "clone" CPUs is governed by a "master" computer by taking advantage of the capabilities of the Secure Shell (ssh) protocol. Any Linux computer on the Internet that can be ssh-accessed by the user can be used as a clone. A key ingredient for the parallel calculation to be reliable is the availability of an independent string of random numbers for each CPU. Many generators—such as RANLUX, RANECU or the Mersenne Twister—can readily produce these strings by initializing them appropriately and, hence, they are suitable to be used with clonEasy. This work was primarily motivated by the need to find a straightforward way to parallelize PENELOPE, a code for MC simulation of radiation transport that (in its current 2005 version) employs the generator RANECU, which uses a combination of two multiplicative linear congruential generators (MLCGs). Thus, this paper is focused on this class of generators and, in particular, we briefly present an extension of RANECU that increases its period up to ˜5×10 and we introduce seedsMLCG, a tool that provides the information necessary to initialize disjoint sequences of an MLCG to feed different CPUs. This program, in combination with clonEasy, allows to run PENELOPE in parallel easily, without requiring specific libraries or significant alterations of the

  17. Space Radar Image of North Sea, Germany

    NASA Technical Reports Server (NTRS)

    1994-01-01

    swiftly than is currently possible. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V.(DLR), the major partner in science, operations and data processing of X-SAR.

  18. Space Radar Image of Los Angeles, California

    NASA Technical Reports Server (NTRS)

    1994-01-01

    -C/X-SAR, scientists will be able to discern these areas even more clearly. Space Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: the L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V.(DLR), the major partner in science, operations and data processing of X-SAR.

  19. Space Radar Image of the Yucatan Impact Crater Site

    NASA Technical Reports Server (NTRS)

    1999-01-01

    to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtange-legenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.v.(DLR), the major partner in science, operations, and data processing of X-SAR. Research on the biological effects of the Chicxulub impact is supported by the NASA Exobiology Program.

  20. Space Radar Image of the Silk route in Niya, Taklamak, China

    NASA Technical Reports Server (NTRS)

    1999-01-01

    -C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: the L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.v.(DLR), the major partner in science, operations and data processing of X-SAR.

  1. Space Radar Image of Mammoth, California

    NASA Technical Reports Server (NTRS)

    1999-01-01

    . The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.v. (DLR), the major partner in science, operations and data processing of X-SAR.

  2. Space Radar Image of Kiluchevskoi, Volcano, Russia

    NASA Technical Reports Server (NTRS)

    1994-01-01

    flanks of the volcano. Paths of these flows can be seen as thin lines in various shades of blue and green on the north flank in the center of the image. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.v.(DLR), the major partner in science, operations and data processing of X-SAR.

  3. Space Radar Image of Karisoke & Virunga Volcanoes

    NASA Technical Reports Server (NTRS)

    1994-01-01

    vegetation maps of the area to aid in their studies of the last 650 mountain gorillas in the world. The faint lines above the bamboo forest are the result of agricultural terracing by the people who live in the region. Spaceborne Imaging Radar-C and X-Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V. (DLR), the major partner in science, operations and data processing of X-SAR.

  4. Space Radar Image of Raco, Michigan, ecological test site

    NASA Technical Reports Server (NTRS)

    1994-01-01

    global changes resulting from climatic warming. Baseline studies of vegetation are essential in monitoring these expected changes. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V.(DLR), the major partner in science, operations and data processing of X-SAR.

  5. Case study for the identification and evaluation of rainfall-runoff models

    NASA Astrophysics Data System (ADS)

    Kaleris, Vassilios; Langousis, Andreas

    2014-05-01

    conceptualizations used in the two rainfall-runoff models. Even for the same model, different parameter sets, which are behavioral, (i.e. they provide comparable but not identical time series of the total runoff), lead to different runoff components. The variability of the runoff components produced using behavioral parameter sets is investigated with the model ENNS. For this purpose, we developed: (a) a code to automatically run the ENNS model for a large number of randomly generated parameter sets, and (b) a multi-criteria procedure for the identification of behavioral parameter sets. Reference Nachtnebel H.P., W. Lettl and St. Baumung (1993): Abflussprognosemodell fuer das Einzugsgebiet der Enns und der Steyr (Handbuch), Institut fuer Wasserwirtschaft, Hydrologie und konstruktiven Wasserbau, Wien, Austria. Acknowledgements This work has been funded by the Helmholtz Center for Environmental Research-UFZ, in Leipzig, Germany, within the project "Estimation of water budgets under changing climatic conditions: examples from Western Greece" under the contract RA-3205/09.

  6. Space Radar Image of Rabaul Volcano, New Guinea

    NASA Technical Reports Server (NTRS)

    1994-01-01

    the image. Ashfall and subsequent rains caused the collapse of most buildings in the town of Rabaul. Mudflows and flooding continue to pose serious threats to the town and surrounding villages. Volcanologists and local authorities expect to use data such as this radar image to assist them in identifying the mechanisms of the eruption and future hazardous conditions that may be associated with the vigorously active volcano. Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.v.(DLR), the major partner in science, operations and data processing of X-SAR.

  7. Safsaf Oasis, Egypt

    NASA Technical Reports Server (NTRS)

    1998-01-01

    is C-band, horizontally transmitted and received; and blue is X-band, vertically transmitted and received. The radar image was acquired by the Spaceborne Imaging Radar-C/ X-band Synthetic Aperture Radar (SIR-C/X-SAR) on April 16, 1994, on board the space shuttle Endeavour. SIR-C/X-SAR, a joint mission of the German, Italian and United States space agencies, is part of NASA's Earth Science Enterprise. The Landsat Program is managed jointly by NASA, the National Oceanic and Atmospheric Administration and the United States Geological Survey.

    Spaceborne Imaging Radar-C and X-Band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.v.(DLR), the major partner in science, operations, and data processing of X-SAR.

  8. Space Radar Image of Manaus, Brazil

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Estaciais, during the first and second flights of the SIR-C/X-SAR system have validated the interpretation of the radar images. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V.(DLR), the major partner in science, operations and data processing of X-SAR.

  9. Space Radar Image of Manaus region of Brazil

    NASA Technical Reports Server (NTRS)

    1994-01-01

    the first and second flights of the SIR-C/X-SAR system have validated the interpretation of the radar images. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V.(DLR), the major partner in science, operations and data processing of X-SAR.

  10. Space Radar Image of Altona, Manitoba, Canada

    NASA Technical Reports Server (NTRS)

    1994-01-01

    the magenta indicate differences in the degree of soil moisture change and differences in surface roughness. This seasonal composite demonstrates the sensitivity of radar to changes in agricultural surface conditions such as soil moisture, tillage, cropping and harvesting. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V.(DLR), the major partner in science, operations and data processing of X-SAR.

  11. Space Radar Image of Glascow, Missouri

    NASA Technical Reports Server (NTRS)

    1994-01-01

    community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V.(DLR), the major partner in science, operations and data processing of X-SAR.

  12. Space Radar Image of Missouri River, Glasgow, Missouri

    NASA Technical Reports Server (NTRS)

    1994-01-01

    ) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V.(DLR), the major partner in science, operations and data processing of X-SAR.

  13. Space Radar Image of Bebedauro, Brazil, seasonal

    NASA Technical Reports Server (NTRS)

    1994-01-01

    -C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V. (DLR), the major partner in science, operations and data processing of X-SAR.

  14. Space Radar Image of Kliuchevskoi Volcano, Russia

    NASA Technical Reports Server (NTRS)

    1994-01-01

    illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrte.v. (DLR), the major partner in science, operations and data processing of X-SAR.

  15. Space Radar Image of Mammoth Mountain, California

    NASA Technical Reports Server (NTRS)

    1994-01-01

    observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm), and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes that are caused by nature and those changes that are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V.(DLR), the major partner in science operations and data processing of X-SAR.

  16. Space Radar Image of Mississippi Delta

    NASA Technical Reports Server (NTRS)

    1999-01-01

    illuminate Earth with microwaves allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.v.(DLR), the major partner in science, operations, and data processing of X-SAR.

  17. Space Radar Image of Taal Volcano, Philippines

    NASA Technical Reports Server (NTRS)

    1994-01-01

    with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.v.(DLR), the major partner in science, operations and data processing of X-SAR.

  18. Space Radar Image of Weddell Sea Ice

    NASA Technical Reports Server (NTRS)

    1994-01-01

    -ice growth perhaps 5 to 10 centimeters (2 to 4 inches) thick. The more extensive dark zones are covered by a slightly thicker layer of smooth, level ice up to 70 centimeters (28 inches) thick. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.v.(DLR), the major partner in science, operations, and data processing of X-SAR.

  19. Space Radar Image of Kilauea Volcano, Hawaii

    NASA Technical Reports Server (NTRS)

    1994-01-01

    radar missions to help in better understanding the processes responsible for volcanic eruptions and earthquakes. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V.(DLR), the major partner in science, operations and data processing of X-SAR.

  20. Space Radar Image of Chernobyl

    NASA Technical Reports Server (NTRS)

    1994-01-01

    conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.v.(DLR), the major partner in science, operations and data processing of X-SAR.

  1. Space Radar Image of Flevoland, Netherlands

    NASA Technical Reports Server (NTRS)

    1999-01-01

    used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrte.v. (DLR), the major partner in science, operations and data processing of X-SAR.

  2. Space Radar Image of Moscow, Russia

    NASA Technical Reports Server (NTRS)

    1994-01-01

    community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V.(DLR), the major partner in science, operations and data processing of X-SAR.

  3. Space Radar Image of the Lost City of Ubar

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Imaging Radar-C and X-Band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtange-legenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.v.(DLR), the major partner in science, operations, and data processing of X-SAR.

  4. Space Radar Image of West Texas - SAR scan

    NASA Technical Reports Server (NTRS)

    1999-01-01

    forthcoming Canadian RADARSAT satellite. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.v.(DLR), the major partner in science, operations, and data processing of X-SAR.

  5. Space Radar Image of Oberpfaffenhofen, Germany

    NASA Technical Reports Server (NTRS)

    1999-01-01

    -C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.v. (DLR), the major partner in science, operations and data processing of X-SAR.

  6. Space Radar Image of Houston, Texas

    NASA Technical Reports Server (NTRS)

    1994-01-01

    -C/X-band Synthetic Aperture Radar(SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI) with the Deutsche Forschungsanstalt fuer luft und Raumfahrt e.V.(DLR), the major partner in science, operations and data processing of X-SAR.

  7. Space Radar Image of Kliuchevskoi, Russia

    NASA Technical Reports Server (NTRS)

    1994-01-01

    mature in Kamchatka's 120-day growing season. The forest industry is managing these forests and practicing selective cutting to allow younger trees time to grow and reseed. X-SAR images will aid in mapping these deforested areas and in encouraging further recultivation efforts. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtange-legenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V.(DLR), the major partner in science, operations and data processing of X-SAR.

  8. Space Radar Image of Colombian Volcano

    NASA Technical Reports Server (NTRS)

    1999-01-01

    weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companiesfor the German space agency, Deutsche Agentur fuer Raumfahrtange-legenheiten (DARA), and the Italian space agency,Agenzia SpazialeItaliana (ASI), with the Deutsche Forschungsanstalt fuer Luft undRaumfahrt e.v.(DLR), the major partner in science,operations, and data processing of X-SAR.

  9. The Construction of the Konrad Repository - Status and Perspective - 13034

    SciTech Connect

    Kunze, V.

    2013-07-01

    Due to the Atomic Energy Act of Germany the Federation is responsible for the construction and operation of installations for the safekeeping and disposal of radioactive waste. The Federal Office for Radiation Protection (Bundesamt fuer Strahlenschutz - BfS) is assigned with this duty. In 1982 the abandoned iron ore mine Konrad near Salzgitter (Federal State of Lower Saxony) was proposed as a repository for low and intermediate level radioactive waste with negligible heat generation. After 20 years of plan approval procedure the license was granted by the Ministry for Environment of Lower Saxony in May 2002. This decision was finally confirmed by the Federal Administrative Court in March 2007. The construction has started, but former assumptions about the beginning of waste emplacement tuned out to be too optimistic. In the course of the preparatory work and the implementation planning it turned out that many changes need to be done. As a matter of fact most of the documents and planning originate from the 1990's and need to be revised because from that time on until now no adaptation was appropriate. The necessity to apply the state-of-the-art technology and other legal implications give rise to further changes and new licensing procedures, especially building licenses. Furthermore, the license from 2002 also includes a lot of collateral clauses that need to be fulfilled before radioactive waste can be emplaced. With this in mind, the time frame for the construction of the Konrad repository was revised in 2010. As a result, the completion of the erection before 2019 does not seem to be realistic. (authors)

  10. LISA 8 Science Organizing Committee and Local Organizing Committee LISA 8 Science Organizing Committee and Local Organizing Committee

    NASA Astrophysics Data System (ADS)

    2011-05-01

    Science Organising Committee (SOC) Tom Abel, Stanford University Odylio Aguiar, Instituto Nacional de Pesquisas Espaciais Tal Alexander, Wizemann Institute Peter Bender, University of Colorado Pierre Binetruy, APC - College de France Sasha Buchman, Stanford University Robert Byer, Stanford University Manuela Campanelli, University of Texas Joan Centrella, NASA/Goddard Massimo Cerdonio, University of Padova Eugenio Coccia, University of Roma-2 Neil Cornish, Montana State University Michael Cruise, University of Birmingham Curt Cutler, NASA/JPL Karsten Danzmann, University of Hannover Sam Finn, Penn State University Jens Gundlach, NPL Gerhard Heinzel, Max-Planck-Institut fuer Gravitationsphysik Craig Hogan, University of Washington Jim Hough, University of Glasgow Scott Hughes, MIT Oliver Jennrich, ESTEC Philippe Jetzer, University Zurich Seiji Kawamura, National Observatory, Japan Alberto Lobo, ICE-CSIC and IEEC Avi Loeb, Harvard University Piero Madau, Lick Observatory Yannick Mellier, IAP, Paris Peter Michelson, Stanford University Guido Mueller, University of Florida Sterl Phinney, Caltech Tom Prince, NASA/JPL Doug Richstone, University of Michigan Bernard Schutz, AEI Potsdam Tuck Stebbins, NASA/Goddard Tim Sumner, Imperial College, London Ke-Xun Sun, Stanford University Kip Thorne, Caltech Michele Vallisneri, NASA/JPL Alberto Vecchio, University of Birmingham Jean-Yves Vinet, OCA, Nice Stefano Vitale, University of Trento Rai Weiss, MIT Nick White, NASA/Goddard Local Organising Committee (LOC) Sasha Buchman (Stanford University) Robert Byer (Stanford University) Sara Charbonneau-Lefort (Stanford University) Nancy Christianson (Stanford University) John Conklin (Stanford University) Dan DeBra (Stanford University) Jan Goebel (Stanford University) Vivian Drew (Stanford University) Ke-Xun Sun (Stanford University) Lucy Zhou (Stanford University) Andrea Zoellner (Stanford University)

  11. DIY EOS: Experimentally Validated Equations of State for Planetary Fluids to GPa Pressures, Tools for Understanding Planetary Processes and Habitability

    NASA Astrophysics Data System (ADS)

    Vance, Steven; Brown, J. Michael; Bollengier, Olivier

    2016-10-01

    Sound speeds are fundamental to seismology, and provide a path allowing the accurate determination of thermodynamic potentials. Prior equations of state (EOS) for pure ammonia (Harr and Gallagher 1978, Tillner-Roth et al. 1993) are based primarily on measured densities and heat capacities. Sound speeds, not included in the fitting, are poorly predicted.We couple recent high pressure sound speed data with prior densities and heat capacities to generate a new equation of state. Our representation fits both the earlier lower pressure work as well as measured sound speeds to 4 GPa and 700 K and the Hugoniot to 70 GPa and 6000 K.In contrast to the damped polynomial representation previously used, our equation of state is based on local basis functions in the form of tensor b-splines. Regularization allows the thermodynamic surface to be continued into regimes poorly sampled by experiments. We discuss application of this framework for aqueous equations of state validated by experimental measurements. Preliminary equations of state have been prepared applying the local basis function methodology to aqueous NH3, Mg2SO4, NaCl, and Na2SO4. We describe its use for developing new equations of state, and provide some applications of the new thermodynamic data to the interior structures of gas giant planets and ocean worlds.References:L. Haar and J. S. Gallagher. Thermodynamic properties of ammonia. American Chemical Society and the American Institute of Physics for the National Bureau of Standards, 1978.R. Tillner-Roth, F. Harms-Watzenberg, and H. Baehr. Eine neue fundamentalgleichung fuer ammoniak. DKV TAGUNGSBERICHT, 20:67-67, 1993.

  12. Protection of Operators and Environment - the Safety Concept of the Karlsruhe Vitrification Plant VEK

    SciTech Connect

    Fleisch, J.; Kuttruf, H.; Lumpp, W.; Pfeifer, W.; Roth, G.; Weisenburger, S.

    2002-02-26

    The Karlsruhe Vitrification Plant (VEK) plant is a milestone in decommissioning and complete dismantling of the former Karlsruhe Reprocessing Plant WAK, which is in an advanced stage of disassembly. The VEK is scheduled to vitrify approx. 70 m3 of the highly radioactive liquid waste (HLW) resulting from reprocessing. Site preparation, civil work and component manufacturing began in 1999. The building will be finalized by mid of 2002, hot vitrification operation is currently scheduled for 2004/2005. Provisions against damages arising from construction and operation of the VEK had to be made in accordance with the state of the art as laid down in the German Atomic Law and the Radiation Protection Regulations. For this purpose, the appropriate analysis of accidents and their external and internal impacts were investigated. During the detailed design phase, a failure effects analysis was carried out, in which single events were studied with respect to the objectives of protection and ensuring activity containment, limiting radioactive discharges to the environment and protecting of the staff. Parallel to the planning phase of the VEK plant a cold prototype test facility (PVA) covering the main process steps was constructed and operated at the Institut fuer Nukleare Entsorgung (INE) of FZK. This pilot operation served to demonstrate the process technique and its operation with a simulated waste solution, and to test the main items of equipment, but was conducted also to use the experimental data and experience to back the safety concept of the radioactive VEK plant. This paper describes the basis of the safety concept of the VEK plant and results of the failure effect analysis. The experimental simulation of the failure scenarios, their effect on the process behavior, and the controllability of these events as well as the effect of the results on the safety concept of VEK are discussed. Additionally, an overview of the actual status of civil work and manufacturing of

  13. Rosetta/COSIMA: High Resolution In-Situ Dust Analysis at Comet 67P/Churyumov-Gerasimenkov

    NASA Astrophysics Data System (ADS)

    Krueger, Harald; Engrand, C.; Fischer, H.; Hilchenbach, M.; Hornung, K.; Kissel, J.; Stephan, T.; Thirkell, L.; Trieloff, M.; Thomas, R.; Tubiana, C.; Varmuza, K.

    2006-09-01

    The COmetary Secondary Ion Mass Analyser (COSIMA) instrument on board ESA's Rosetta spacecraft is a high-resolution time-of-flight mass spectrometer dedicated to the in-situ analysis of cometary dust. Rosetta was launched in 2004 and will reach comet 67P/Churyumov-Gerasimenkov in 2014. The COSIMA instrument will collect cometary dust on metal targets and identify grains with sizes 10 micron and bigger with an optical camera. Material from the grain surface is sputtered with an indium ion beam and the generated secondary ions are accelerated in an electric field. Time-of-flight secondary ion mass spectra are obtained with a mass resolution of approximately 2000 at m = 100 amu. The goal of the COSIMA investigation is the in-situ characterisation of the elemental, molecular, mineralogic, and isotopic composition of dust in the coma of comet 67P/C-G. To reach this goal, we perform an extensive laboratory measurement program with a COSIMA reference instrument (RM), a twin of the flight instrument, located at Max-Planck-Institut fuer Sonnensystemforschung (MPS). Cometary dust analogues are prepared from natural and synthetic minerals (pyroxene, olivine, hydrous silicates, sulfides, etc.) with known composition and, which are believed to exist in comets. Reference spectra of these samples are obtained with the COSIMA RM instrument and with laboratory time-of-flight secondary ion mass spectrometer (TOF-SIMS) instruments located at the University of Muenster/Germany and the Laboratoire de Physique & Chimie de L'Environment in Orleans/France. We will present first results on the calibration of the COSIMA RM instrument and the identification of the elemental and mineralogic composition of reference samples.

  14. X-ray And EUV Spectroscopy Of Highly Charged Tungsten Ions

    SciTech Connect

    Biedermann, Christoph; Radtke, Rainer

    2009-09-10

    The Berlin EBIT has been established by the Max-Planck-Institut fuer Plasmaphysik to generate atomic physics data in support of research in the field of controlled nuclear fusion, by measuring the radiation from highly charged ions in the x-ray, extreme ultraviolet and visible spectral ranges and providing valuable diagnostics for high temperature plasmas. In future fusion devices, for example ITER, currently being constructed at Cadarache, France, the plasma facing components will be armored with high-Z materials, most likely tungsten, due to the favorable properties of this element. At the same time the tremendous radiation cooling of these high-Z materials represents a threat to fusion and obliges one to monitor carefully the radiation. With EBIT a selected ensemble of ions in specific charge states can be produced, stored and excited for spectroscopic investigations. Employing this technique, we have for example resolved the wide structure observed around 5 nm at the ASDEX Upgrade tokamak as originating from E1-transitions into the open 4d shell of tungsten ions in charge states 25+ to 37+ producing a band-like emission pattern. Further, these ions emit well-separated M1 lines in the EUV range around 65 nm suitable for plasma diagnostics. Kr-like to Cr-like tungsten ions (38+ to 50+) show strong soft-x-ray lines in the range 0.5 to 2 and 5 to 15 nm. Lines of even higher charged tungsten ions, up to Ne-like W{sup 64+}, abundant in the core plasma of present and future fusion test devices, have been investigated with high resolution Bragg-crystal spectroscopy at 0.13 nm. Recently, x-ray spectroscopic measurements of the dielectronic recombination LMn resonances of W{sup 60+} to W{sup 67+} ions have been preformed and compare well with atomic structure calculations.

  15. Clearance Measurements prior to the Shut-Down of ERAM

    SciTech Connect

    Kunze, V.; Ibach, T.M.

    2008-07-01

    Low and intermediate level radioactive waste was emplaced in the Morsleben Repository (ERAM), a former salt mine, until 1998. Now the German Federal Office for Radiation Protection (Bundesamt fuer Strahlenschutz - BfS) has applied for the decommissioning of the plant. The ERAM's own radioactive waste requires clearance as far as it may not remain in the repository. The German Mining Law also demands all non-mining typical waste to be removed from the mine when being decommissioned and the Waste Avoidance, Recovery and Disposal Act demands waste to remain within the economy cycle if this is economically justifiable. Therefore new clearance measuring devices have to be applied using gamma and beta radiation to determine the contamination of objects and substances regarding the special nuclide spectra in the ERAM. Even if a very multifaceted radionuclide spectrum is to be expected due to the fact that the emplaced waste results from various applications such as nuclear engineering, medicine, research, and military, numerous investigations have confirmed that only a few radionuclides have to be considered. To facilitate this procedure the controlled area of the ERAM is to be classified according to different contamination categories. Assumptions about the radionuclide mixture are permanently controlled by routine measurements and the evaluation of possible contamination events. The considerations about the radionuclide mixture and the structure of the controlled area will be described in this presentation. Furthermore a new methodology to measure Sr-90 is discussed which uses the Cerenkov effect and the low level of background gamma radiation in the salt mine. (authors)

  16. Gas Generation Rates as an Indicator for the Long Term Stability of Radioactive Waste Products

    SciTech Connect

    Steyer, S.; Brennecke, P.; Bandt, G.; Kroger, H.

    2007-07-01

    Pursuant to the 'Act on the Peaceful Utilization of Atomic Energy and the Protection against its Hazards' (Atomic Energy Act) the Federal Office for Radiation Protection (Bundesamt fuer Strahlenschutz, BfS) is legally responsible for the construction and operation of federal facilities for the disposal of radioactive waste. Within the scope of this responsibility, particular due to par. 74(1) Ordinance on Radiation Protection, BfS defines all safety-related requirements on waste packages envisaged for disposal, establishes guidelines for the conditioning of radioactive waste and approves the fulfillment of the waste acceptance requirements within the radioactive waste quality control system. BfS also provides criteria to enable the assessment of methods for the treatment and packaging of radioactive waste to produce waste packages suitable for disposal according to par. 74(2) Ordinance on Radiation Protection. Due to the present non-availability of a repository in Germany, quality control measures for all types of radioactive waste products are carried out prior to interim storage with respect to the future disposal. As a result BfS approves the demonstrated properties of the radioactive waste packages and confirms the fulfillment of the respective requirements. After several years of storage the properties of waste packages might have changed. By proving, that such changes have no significant impact on the quality of the waste product, the effort of requalification could be minimized. Therefore, data on the long-term behavior of radioactive waste products need to be acquired and indicators to prove the long-term stability have to be quantified. Preferably, such indicators can be determined easily with non-destructive methods, even for legacy waste packages. A promising parameter is the gas generation rate. The relationship between gas generation rate and long term stability is presented as first result of an ongoing study on behalf of BfS. Permissible gas

  17. Methodology, status and plans for development and assessment of the code ATHLET

    SciTech Connect

    Teschendorff, V.; Austregesilo, H.; Lerchl, G.

    1997-07-01

    The thermal-hydraulic computer code ATHLET (Analysis of THermal-hydraulics of LEaks and Transients) is being developed by the Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) for the analysis of anticipated and abnormal plant transients, small and intermediate leaks as well as large breaks in light water reactors. The aim of the code development is to cover the whole spectrum of design basis and beyond design basis accidents (without core degradation) for PWRs and BWRs with only one code. The main code features are: advanced thermal-hydraulics; modular code architecture; separation between physical models and numerical methods; pre- and post-processing tools; portability. The code has features that are of special interest for applications to small leaks and transients with accident management, e.g. initialization by a steady-state calculation, full-range drift-flux model, dynamic mixture level tracking. The General Control Simulation Module of ATHLET is a flexible tool for the simulation of the balance-of-plant and control systems including the various operator actions in the course of accident sequences with AM measures. The code development is accompained by a systematic and comprehensive validation program. A large number of integral experiments and separate effect tests, including the major International Standard Problems, have been calculated by GRS and by independent organizations. The ATHLET validation matrix is a well balanced set of integral and separate effects tests derived from the CSNI proposal emphasizing, however, the German combined ECC injection system which was investigated in the UPTF, PKL and LOBI test facilities.

  18. Autocollimators for Deflectometry: Current Status and Future Progress

    SciTech Connect

    Geckeler, Ralf; Just, Andreas; Krause, Michael; Yashchuk, Valeriy V.

    2009-06-15

    The proliferation of autocollimator-based surface profilometers at synchrotron metrology laboratories worldwide necessitates a detailed understanding of the parameters influencing their angular response. A comprehensive overview of the current status of autocollimator characterization and calibration at the Physikalisch-Technische Bundesanstalt (PTB) and its implications for their optimal application are provided, as well as information on future challenges and expected progress. Autocollimator-based deflectometric profilometers are in operation at the PTB, the Advanced Light Source (ALS), Lawrence Berkeley National Laboratory, USA, the BESSY II, Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Germany, and the Diamond Light Source Ltd (DLS), UK. A continuous topic of research at the PTB is to investigate the factors influencing the angular response of autocollimators and to provide the most accurate calibration of the instruments to aid users in their application and manufacturers in their improvements [1-3]. At the PTB, the calibration of autocollimators is realized by a direct comparison of the devices with the primary angle reference standard [1]. With highly stable autocollimators, calibrations with standard measurement uncertainties of u = 0.003 arcsec (15 nrad) have been achieved [2,3]. The influence of a number of parameters on the angle measurement with autocollimators have been investigated in detail, such as the reflectivity of the surface under test (SUT), the diameter and shape of the aperture stop, its position both along the autocollimator's optical axis and perpendicular to it [2], as well as the optical path length of the autocollimator beam [3]. Extensive information on these errors and their minimization will be presented.

  19. The Musca cloud: A 6 pc-long velocity-coherent, sonic filament

    NASA Astrophysics Data System (ADS)

    Hacar, A.; Kainulainen, J.; Tafalla, M.; Beuther, H.; Alves, J.

    2016-03-01

    Filaments play a central role in the molecular clouds' evolution, but their internal dynamical properties remain poorly characterized. To further explore the physical state of these structures, we have investigated the kinematic properties of the Musca cloud. We have sampled the main axis of this filamentary cloud in 13CO and C18O (2-1) lines using APEX observations. The different line profiles in Musca shows that this cloud presents a continuous and quiescent velocity field along its ~6.5 pc of length. With an internal gas kinematics dominated by thermal motions (i.e. σNT/cs ≲ 1) and large-scale velocity gradients, these results reveal Musca as the longest velocity-coherent, sonic-like object identified so far in the interstellar medium. The transonic properties of Musca present a clear departure from the predicted supersonic velocity dispersions expected in the Larson's velocity dispersion-size relationship, and constitute the first observational evidence of a filament fully decoupled from the turbulent regime over multi-parsec scales. This publication is based on data acquired with the Atacama Pathfinder Experiment (APEX). APEX is a collaboration between the Max-Planck-Institut fuer Radioastronomie, the European Southern Observatory, and the Onsala Space Observatory (ESO programme 087.C-0583).The reduced datacubes as FITS files are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/587/A97

  20. Carbon ion radiotherapy of skull base chondrosarcomas

    SciTech Connect

    Schulz-Ertner, Daniela . E-mail: Daniela.Ertner@med.uni-heidelberg.de; Nikoghosyan, Anna; Hof, Holger; Didinger, Bernd; Combs, Stephanie E.; Jaekel, Oliver; Karger, Christian P.; Edler, Lutz; Debus, Juergen

    2007-01-01

    Purpose: To evaluate the effectiveness and toxicity of carbon ion radiotherapy in chondrosarcomas of the skull base. Patients and Methods: Between November 1998 and September 2005, 54 patients with low-grade and intermediate-grade chondrosarcomas of the skull base have been treated with carbon ion radiation therapy (RT) using the raster scan technique at the Gesellschaft fuer Schwerionenforschung in Darmstadt, Germany. All patients had gross residual tumors after surgery. Median total dose was 60 CGE (weekly fractionation 7 x 3.0 CGE). All patients were followed prospectively in regular intervals after treatment. Local control and overall survival rates were calculated using the Kaplan-Meier method. Toxicity was assessed according to the Common Terminology Criteria (CTCAE v.3.0) and Radiation Therapy Oncology Group (RTOG)/European Organization for Research and Treatment of Cancer (EORTC) score. Results: Median follow-up was 33 months (range, 3-84 months). Only 2 patients developed local recurrences. The actuarial local control rates were 96.2% and 89.8% at 3 and 4 years; overall survival was 98.2%at 5 years. Only 1 patient developed a mucositis CTCAE Grade 3; the remaining patients did not develop any acute toxicities >CTCAE Grade 2. Five patients developed minor late toxicities (RTOG/EORTC Grades 1-2), including bilateral cataract (n = 1), sensory hearing loss (n = 1), a reduction of growth hormone (n = 1), and asymptomatic radiation-induced white matter changes of the adjacent temporal lobe (n = 2). Grade 3 late toxicity occurred in 1 patient (1.9%) only. Conclusions: Carbon ion RT is an effective treatment for low- and intermediate-grade chondrosarcomas of the skull base offering high local control rates with low toxicity.

  1. Effectiveness of Carbon Ion Radiotherapy in the Treatment of Skull-Base Chordomas

    SciTech Connect

    Schulz-Ertner, Daniela . E-mail: Daniela.Ertner@med.uni-heidelberg.de; Karger, Christian P.; Feuerhake, Alexandra; Nikoghosyan, Anna; Combs, Stephanie E.; Jaekel, Oliver; Edler, Lutz; Scholz, Michael; Debus, Juergen

    2007-06-01

    Purpose: The aim of this study was to evaluate the effectiveness and toxicity of carbon ion radiotherapy in chordomas of the skull base. Methods and Materials: Between November 1998 and July 2005, a total of 96 patients with chordomas of the skull base have been treated with carbon ion radiation therapy (RT) using the raster scan technique at the Gesellschaft fuer Schwerionenforschung (GSI) in Darmstadt, Germany. All patients had gross residual tumors. Median total dose was 60 CGE (range, 60-70 CGE) delivered in 20 fractions within 3 weeks. Local control and overall survival rates were calculated using the Kaplan-Meier method. Toxicity was assessed according to the Common Terminology Criteria (CTCAE v.3.0) and the Radiation Therapy Oncology Group (RTOG) / European Organization for Research and Treatment of Cancer (EORTC) score. Results: Mean follow-up was 31 months (range, 3-91 months). Fifteen patients developed local recurrences after carbon ion RT. The actuarial local control rates were 80.6% and 70.0% at 3 and 5 years, respectively. Target doses in excess of 60 CGE and primary tumor status were associated with higher local control rates. Overall survival was 91.8% and 88.5% at 3 and 5 years, respectively. Late toxicity consisted of optic nerve neuropathy RTOG/EORTC Grade 3 in 4.1% of the patients and necrosis of a fat plomb in 1 patient. Minor temporal lobe injury (RTOG/EORTC Grade 1-2) occurred in 7 patients (7.2%). Conclusions: Carbon ion RT offers an effective treatment option for skull-base chordomas with acceptable toxicity. Doses in excess of 75 CGE with 2 CGE per fraction are likely to increase local control probability.

  2. Correlations between posterior longitudinal ligament status and size of bone fragment in thoracolumbar burst fractures

    PubMed Central

    Hu, Zhaohui; Zhou, Yanhong; Li, Ningning; Xie, Xiangtao

    2015-01-01

    This study aim to determine the correlation between the size of bone fragment and injury of posterior longitudinal ligament (PLL). In this study retrospectively analyze medical chart of patients with thoracolumbar burst fractures from June 2010 to December 2012. Patients were divided into two groups (Intact group and Disrupted group) according to the result of MRI assessing status of PLL. All the fractures were classified according to the Arbeit Fuer Osteoosynthese (AO) classification system. Neurological status was classified according to American Spinal Injury Association (ASIA). Mimics measured the height and width of bone fragment (HBF and WBF), transverse canal diameter (TCD) and calculate the height of posterior wall of the injury vertebrae, ratio of height of bone fragment occupying height of posterior wall of vertebrae body (RHBF) and ratio of width of bone fragment occupying transverse canal diameter (RWBF). The results indicated that 52 patients were included in the study. There are 31 patients with intact PLL and 21 patients with disrupted PLL. There was significant difference on the HBF (t = -3.646, P = 0.001), WBF (t = -3.615, P = 0.001), RHBF (t = -4.124, P = 0.000) and RWBF (t = -3.305, P = 0.002) between the intact group and injury group. There was a significant correlation between injury of PLL and ASIA grade (OR = 7.851, P = 0.005), and AO classification (OR = 6.401, P = 0.011), and RHBF (OR = 6.455, P = 0.011), and HBF (OR = 5.208, P = 0.022). In conclusion, the results of this study indicate that AO classification, ASIA grade, HBF and RHBF could act as the predictors of injury of PLL. PMID:25932230

  3. Natural and False Color Views of Europa

    NASA Technical Reports Server (NTRS)

    1996-01-01

    This image shows two views of the trailing hemisphere of Jupiter's ice-covered satellite, Europa. The left image shows the approximate natural color appearance of Europa. The image on the right is a false-color composite version combining violet, green and infrared images to enhance color differences in the predominantly water-ice crust of Europa. Dark brown areas represent rocky material derived from the interior, implanted by impact, or from a combination of interior and exterior sources. Bright plains in the polar areas (top and bottom) are shown in tones of blue to distinguish possibly coarse-grained ice (dark blue) from fine-grained ice (light blue). Long, dark lines are fractures in the crust, some of which are more than 3,000 kilometers (1,850 miles) long. The bright feature containing a central dark spot in the lower third of the image is a young impact crater some 50 kilometers (31 miles) in diameter. This crater has been provisionally named 'Pwyll' for the Celtic god of the underworld.

    Europa is about 3,160 kilometers (1,950 miles) in diameter, or about the size of Earth's moon. This image was taken on September 7, 1996, at a range of 677,000 kilometers (417,900 miles) by the solid state imaging television camera onboard the Galileo spacecraft during its second orbit around Jupiter. The image was processed by Deutsche Forschungsanstalt fuer Luftund Raumfahrt e.V., Berlin, Germany.

    The Jet Propulsion Laboratory, Pasadena, CA, manages the mission for NASA's Office of Space Science, Washington, DC.

    This image and other images and data received from Galileo are posted on the Galileo mission home page on the World Wide Web at http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at http://www.jpl.nasa.gov/galileo/sepo

  4. Multi objectives model to optimise the economical value of agriculture water use in Gaza Strip

    NASA Astrophysics Data System (ADS)

    Ouda, O.; Bardossy, A.

    2003-04-01

    Multi objectives model to optimise the economical value of agriculture water use in Gaza Strip. O. Ouda (1), A. Bárdossy (1) (1) Institut fuer Wasserbau, Universitaet Stuttgart Fax: +49-(0)711-685-4746/ e-mail: omar.ouda@iws.uni-stuttgart.de Key words: Multi objectives model, agriculture water use, and Gaza Strip. ============================================================================ Abstract The Gaza Strip faces a serious water shortage problem, with a present water shortage of about 61 Mm3/year. The problem is projected to become even larger in the future due to a high population growth of about 3.2%. The water deficit is presently covered by abstraction of the groundwater beyond the sustainable yield, where groundwater is the only natural source in Gaza strip. Irrigated agriculture consumed about 60% (90 Mm3/year) of water in Gaza strip. The economical value of water used for agriculture propose is very low in comparison with water opportunity cost of 1 US/m3 , ( seawater desalination cost). A Multi objective optimisation model (MOM) based on mathematical programming techniques aimed to optimise the economical return value of agriculture water use has been formulated, where 20 crops distributed over 16 zones have been considered. The available agriculture area, Available treated wastewater, Local agriculture products demand were considered as constrains. Irrigation water demand for each crop for three meteorological conditions dry, wet and average year, and Average product prices were considered as variables. A modification of the MOM models has been made toward equitable profit distribution (US/hectare) among the different 16 zones, where additional constrain of minimum profit per hectare in each zone has been implemented. Finally a sensitivity analysis for the effect of water price, crop price and crop products demand on the model output has been made. The MOM presents a good analytical basis for policy makers toward optimising the economical return of

  5. Performance Simulations for a Spaceborne Methane Lidar Mission

    NASA Technical Reports Server (NTRS)

    Kiemle, C.; Kawa, Stephan Randolph; Quatrevalet, Mathieu; Browell, Edward V.

    2014-01-01

    Future spaceborne lidar measurements of key anthropogenic greenhouse gases are expected to close current observational gaps particularly over remote, polar, and aerosol-contaminated regions, where actual in situ and passive remote sensing observation techniques have difficulties. For methane, a "Methane Remote Lidar Mission" was proposed by Deutsches Zentrum fuer Luft- und Raumfahrt and Centre National d'Etudes Spatiales in the frame of a German-French climate monitoring initiative. Simulations assess the performance of this mission with the help of Moderate Resolution Imaging Spectroradiometer and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations of the earth's surface albedo and atmospheric optical depth. These are key environmental parameters for integrated path differential absorption lidar which uses the surface backscatter to measure the total atmospheric methane column. Results showthat a lidar with an average optical power of 0.45W at 1.6 µm wavelength and a telescope diameter of 0.55 m, installed on a low Earth orbit platform(506 km), will measure methane columns at precisions of 1.2%, 1.7%, and 2.1% over land, water, and snow or ice surfaces, respectively, for monthly aggregated measurement samples within areas of 50 × 50 km2. Globally, the mean precision for the simulated year 2007 is 1.6%, with a standard deviation of 0.7%. At high latitudes, a lower reflectance due to snow and ice is compensated by denser measurements, owing to the orbital pattern. Over key methane source regions such as densely populated areas, boreal and tropical wetlands, or permafrost, our simulations show that the measurement precision will be between 1 and 2%.

  6. Correlation of bone fragments reposition and related parameters in thoracolumbar burst fractures patients

    PubMed Central

    Dai, Jianhui; Lin, Haibin; Niu, Susheng; Wu, Xianwei; Wu, Yujun; Zhang, Huaizhi

    2015-01-01

    The aim of this study is to determine if thoracolumbar vertebral body collapse or canal compromise (CC) is associated with reposition of bone fragment. We retrospective review medical charts of patients with thoracolumbar burst fractures from July 2010 to September 2013. The fractures were classified according to the Arbeit Fuer Osteoosynthese (AO) classification system. Neurological status was classified according to American Spinal Injury Association (ASIA). Patients were divided into two groups (reposition group and non-reposition group) according to whether the bone fragments were reposition or non-reposition after surgery. Mimics measured mid-sagittal canal diameter (MSD), transverse canal diameter (TCD), local kyphosis (LK) and calculated anterior vertebral body compression ratio (AVBCR), middle vertebral body compression ratio (MVBCR), posterior vertebral body compression ratio (PVBCR), and mid-sagittal canal diameter compression ratio (MSDCR) on the preoperative CT image. The results indicated that 55 patients were included in the study. There are 35 patients with reposition of bone fragment and 20 patients with non-reposition of bone fragment after surgery. There were significant difference on MSD (t = 3.258, P = 0.002), TCD (t = 2.197, P = 0.032), AVBCR (t = -2.063, P = 0.044), MVBCR (t = -2.526, P = 0.015), PVBCR (t = -2.211, P = 0.031), MSDCR (t = -4.975, P = 0.000) between two groups before surgery. There was a significant correlation between reposition of bone fragment and AO classification (OR = 5.251, P = 0.022), and MSDCR (OR = 7.366, P = 0.007). There was no significant correlation between reposition and AVBCR, MVBCR, PVBCR, LK, MSD and TCD. In conclusion, this study indicates that AO classification and MSDCR are predictors of reposition of bone fragment. PMID:26379913

  7. Precision measurement of the integrated luminosity of the data taken by BESIII at center-of-mass energies between 3.810 GeV and 4.600 GeV

    NASA Astrophysics Data System (ADS)

    Ablikim, M.; N. Achasov, M.; Ai, X. C.; Albayrak, O.; Albrecht, M.; J. Ambrose, D.; Amoroso, A.; An, F. F.; An, Q.; Bai, J. Z.; R. Baldini, Ferroli; Ban, Y.; W. Bennett, D.; V. Bennett, J.; Bertani, M.; Bettoni, D.; Bian, J. M.; Bianchi, F.; Boger, E.; Bondarenko, O.; Boyko, I.; A. Briere, R.; Cai, H.; Cai, X.; Cakir, O.; Calcaterra, A.; Cao, G. F.; A. Cetin, S.; Chang, J. F.; Chelkov, G.; Chen, G.; Chen, H. S.; Chen, H. Y.; Chen, J. C.; Chen, M. L.; Chen, S. J.; Chen, X.; Chen, X. R.; Chen, Y. B.; Cheng, H. P.; Chu, X. K.; Cibinetto, G.; Cronin-Hennessy, D.; Dai, H. L.; Dai, J. P.; Dbeyssi, A.; Dedovich, D.; Deng, Z. Y.; Denig, A.; Denysenko, I.; Destefanis, M.; F. De, Mori; Ding, Y.; Dong, C.; Dong, J.; Dong, L. Y.; Dong, M. Y.; Du, S. X.; Duan, P. F.; Fan, J. Z.; Fang, J.; Fang, S. S.; Fang, X.; Fang, Y.; Fava, L.; Feldbauer, F.; Felici, G.; Feng, C. Q.; Fioravanti, E.; Fritsch, M.; Fu, C. D.; Gao, Q.; Gao, Y.; Gao, Z.; Garzia, I.; Geng, C.; Goetzen, K.; Gong, W. X.; Gradl, W.; Greco, M.; Gu, M. H.; Gu, Y. T.; Guan, Y. H.; Guo, A. Q.; Guo, L. B.; Guo, Y.; P. Guo, Y.; Haddadi, Z.; Hafner, A.; Han, S.; Han, Y. L.; Hao, X. Q.; A. Harris, F.; He, K. L.; He, Z. Y.; Held, T.; Heng, Y. K.; Hou, Z. L.; Hu, C.; Hu, H. M.; Hu, J. F.; Hu, T.; Hu, Y.; Huang, G. M.; Huang, G. S.; Huang, H. P.; Huang, J. S.; Huang, X. T.; Huang, Y.; Hussain, T.; Ji, Q.; Ji, Q. P.; Ji, X. B.; Ji, X. L.; Jiang, L. L.; Jiang, L. W.; Jiang, X. S.; Jiao, J. B.; Jiao, Z.; Jin, D. P.; Jin, S.; Johansson, T.; Julin, A.; Kalantar-Nayestanaki, N.; Kang, X. L.; Kang, X. S.; Kavatsyuk, M.; C. Ke, B.; Kliemt, R.; Kloss, B.; B. Kolcu, O.; Kopf, B.; Kornicer, M.; Kuehn, W.; Kupsc, A.; Lai, W.; S. Lange, J.; M., Lara; Larin, P.; Leng, C.; Li, C. H.; Li, Cheng; Li, D. M.; Li, F.; Li, G.; Li, H. B.; Li, J. C.; Li, Jin; Li, K.; Li, K.; Li, Lei; Li, P. R.; Li, T.; Li, W. D.; Li, W. G.; Li, X. L.; Li, X. M.; Li, X. N.; Li, X. Q.; Li, Z. B.; Liang, H.; Liang, Y. F.; Liang, Y. T.; Liao, G. R.; X. Lin(Lin, D.; Liu, B. J.; Liu, C. X.; Liu, F. H.; Liu, Fang; Liu, Feng; Liu, H. B.; Liu, H. H.; Liu, H. H.; Liu, H. M.; Liu, J.; Liu, J. P.; Liu, J. Y.; Liu, K.; Liu, K. Y.; Liu, L. D.; Liu, P. L.; Liu, Q.; Liu, S. B.; Liu, X.; Liu, X. X.; Liu, Y. B.; Liu, Z. A.; Liu, Zhiqiang; Zhiqing, Liu; Loehner, H.; Lou, X. C.; Lu, H. J.; Lu, J. G.; Lu, R. Q.; Lu, Y.; Lu, Y. P.; Luo, C. L.; Luo, M. X.; Luo, T.; Luo, X. L.; Lv, M.; Lyu, X. R.; Ma, F. C.; Ma, H. L.; Ma, L. L.; Ma, Q. M.; Ma, S.; Ma, T.; Ma, X. N.; Ma, X. Y.; E. Maas, F.; Maggiora, M.; A. Malik, Q.; Mao, Y. J.; Mao, Z. P.; Marcello, S.; G. Messchendorp, J.; Min, J.; Min, T. J.; E. Mitchell, R.; Mo, X. H.; Mo, Y. J.; C. Morales, Morales; Moriya, K.; Yu. Muchnoi, N.; Muramatsu, H.; Nefedov, Y.; Nerling, F.; B. Nikolaev, I.; Ning, Z.; Nisar, S.; Niu, S. L.; Niu, X. Y.; Olsen, S. L.; Ouyang, Q.; Pacetti, S.; Patteri, P.; Pelizaeus, M.; Peng, H. P.; Peters, K.; Ping, J. L.; Ping, R. G.; Poling, R.; Pu, Y. N.; Qi, M.; Qian, S.; Qiao, C. F.; Qin, L. Q.; Qin, N.; Qin, X. S.; Qin, Y.; Qin, Z. H.; Qiu, J. F.; H. Rashid, K.; F. Redmer, C.; Ren, H. L.; Ripka, M.; Rong, G.; Ruan, X. D.; Santoro, V.; Sarantsev, A.; Savrié, M.; Schoenning, K.; Schumann, S.; Shan, W.; Shao, M.; Shen, C. P.; Shen, P. X.; Shen, X. Y.; Sheng, H. Y.; Song, W. M.; Song, X. Y.; Sosio, S.; Spataro, S.; Sun, G. X.; Sun, J. F.; Sun, S. S.; Sun, Y. J.; Sun, Y. Z.; Sun, Z. J.; Sun, Z. T.; Tang, C. J.; Tang, X.; Tapan, I.; H. Thorndike, E.; Tiemens, M.; Toth, D.; Ullrich, M.; Uman, I.; S. Varner, G.; Wang, B.; Wang, B. L.; Wang, D.; Wang, D. Y.; Wang, K.; Wang, L. L.; Wang, L. S.; Wang, M.; Wang, P.; Wang, P. L.; Wang, Q. J.; Wang, S. G.; Wang, W.; Wang, X. F.; Yadi, Wang; Wang, Y. F.; Wang, Y. Q.; Wang, Z.; Wang, Z. G.; Wang, Z. H.; Wang, Z. Y.; Weber, T.; Wei, D. H.; Wei, J. B.; Weidenkaff, P.; Wen, S. P.; Wiedner, U.; Wolke, M.; Wu, L. H.; Wu, Z.; Xia, L. G.; Xia, Y.; Xiao, D.; Xiao, Z. J.; Xie, Y. G.; Xiu, Q. L.; Xu, G. F.; Xu, L.; Xu, Q. J.; Xu, Q. N.; Xu, X. P.; Yan, L.; Yan, W. B.; Yan, W. C.; Yan, Y. H.; Yang, H. X.; Yang, L.; Yang, Y.; Yang, Y. X.; Ye, H.; Ye, M.; Ye, M. H.; Yin, J. H.; Yu, B. X.; Yu, C. X.; Yu, H. W.; Yu, J. S.; Yuan, C. Z.; Yuan, W. L.; Yuan, Y.; Yuncu, A.; A. Zafar, A.; Zallo, A.; Zeng, Y.; Zhang, B. X.; Zhang, B. Y.; Zhang, C.; Zhang, C. C.; Zhang, D. H.; Zhang, H. H.; Zhang, H. Y.; Zhang, J. J.; Zhang, J. L.; Zhang, J. Q.; Zhang, J. W.; Zhang, J. Y.; Zhang, J. Z.; Zhang, K.; Zhang, L.; Zhang, S. H.; Zhang, X. Y.; Zhang, Y.; Zhang, Y. H.; Zhang, Y. T.; Zhang, Z. H.; Zhang, Z. P.; Zhang, Z. Y.; Zhao, G.; Zhao, J. W.; Zhao, J. Y.; Zhao, J. Z.; Zhao, Lei; Zhao, Ling; Zhao, M. G.; Zhao, Q.; Zhao, Q. W.; Zhao, S. J.; Zhao, T. C.; Zhao, Y. B.; Zhao, Z. G.; Zhemchugov, A.; Zheng, B.; Zheng, J. P.; Zheng, W. J.; Zheng, Y. H.; Zhong, B.; Zhou, L.; Zhou, Li; Zhou, X.; Zhou, X. K.; Zhou, X. R.; Zhou, X. Y.; Zhu, K.; Zhu, K. J.; Zhu, S.; Zhu, X. L.; Zhu, Y. C.; Zhu, Y. S.; Zhu, Z. A.; Zhuang, J.; Zotti, L.; Zou, B. S.; Zou, J. H.; BESIII Collaboration

    2015-09-01

    From December 2011 to May 2014, about 5 fb-1 of data were taken with the BESIII detector at center-of-mass energies between 3.810 GeV and 4.600 GeV to study the charmonium-like states and higher excited charmonium states. The time-integrated luminosity of the collected data sample is measured to a precision of 1% by analyzing events produced by the large-angle Bhabha scattering process. Supported by National Key Basic Research Program of China (2015CB856700), National Natural Science Foundation of China (NSFC) (11125525, 11235011, 11322544, 11335008, 11425524), Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Program, Joint Large-Scale Scientific Facility Funds of the NSFC and CAS (11179007, U1232201, U1332201) CAS (KJCX2-YW-N29, KJCX2-YW-N45), 100 Talents Program of CAS, INPAC and Shanghai Key Laboratory for Particle Physics and Cosmology, German Research Foundation DFG (Collaborative Research Center CRC-1044), Istituto Nazionale di Fisica Nucleare, Italy; Ministry of Development of Turkey (DPT2006K-120470), Russian Foundation for Basic Research (14-07-91152), U.S. Department of Energy (DE-FG02-04ER41291, DE-FG02-05ER41374, DE-FG02-94ER40823, DESC0010118), U.S. National Science Foundation, University of Groningen (RuG) and the Helmholtzzentrum fuer Schwerionenforschung GmbH (GSI), Darmstadt and WCU Program of National Research Foundation of Korea (R32-2008-000-10155-0)

  8. Measurement of the absolute branching fraction of D+ → K̅0 e+νe via K̅0 → π 0 π 0

    NASA Astrophysics Data System (ADS)

    Ablikim, M.; Achasov, M. N.; Ai, X. C.; Albayrak, O.; Albrecht, M.; Ambrose, D. J.; Amoroso, A.; An, F. F.; An, Q.; Bai, J. Z.; Baldini Ferroli, R.; Ban, Y.; Bennett, D. W.; Bennett, J. V.; Bertani, M.; Bettoni, D.; Bian, J. M.; Bianchi, F.; Boger, E.; Boyko, I.; Briere, R. A.; Cai, H.; Cai, X.; Cakir, O.; Calcaterra, A.; Cao, G. F.; Cetin, S. A.; Chang, J. F.; Chelkov, G.; Chen, G.; Chen, H. S.; Chen, H. Y.; Chen, J. C.; Chen, M. L.; Chen, S.; Chen, S. J.; Chen, X.; Chen, X. R.; Chen, Y. B.; Cheng, H. P.; Chu, X. K.; Cibinetto, G.; Dai, H. L.; Dai, J. P.; Dbeyssi, A.; Dedovich, D.; Deng, Z. Y.; Denig, A.; Denysenko, I.; Destefanis, M.; De Mori, F.; Ding, Y.; Dong, C.; Dong, J.; Dong, L. Y.; Dong, M. Y.; Dou, Z. L.; Du, S. X.; Duan, P. F.; Fan, J. Z.; Fang, J.; Fang, S. S.; Fang, X.; Fang, Y.; Farinelli, R.; Fava, L.; Fedorov, O.; Feldbauer, F.; Felici, G.; Feng, C. Q.; Fioravanti, E.; Fritsch, M.; Fu, C. D.; Gao, Q.; Gao, X. L.; Gao, X. Y.; Gao, Y.; Gao, Z.; Garzia, I.; Goetzen, K.; Gong, L.; Gong, W. X.; Gradl, W.; Greco, M.; Gu, M. H.; Gu, Y. T.; Guan, Y. H.; Guo, A. Q.; Guo, L. B.; Guo, R. P.; Guo, Y.; Guo, Y. P.; Haddadi, Z.; Hafner, A.; Han, S.; Hao, X. Q.; Harris, F. A.; He, K. L.; Held, T.; Heng, Y. K.; Hou, Z. L.; Hu, C.; Hu, H. M.; Hu, J. F.; Hu, T.; Hu, Y.; Huang, G. S.; Huang, J. S.; Huang, X. T.; Huang, X. Z.; Huang, Y.; Huang, Z. L.; Hussain, T.; Ji, Q.; Ji, Q. P.; Ji, X. B.; Ji, X. L.; Jiang, L. W.; Jiang, X. S.; Jiang, X. Y.; Jiao, J. B.; Jiao, Z.; Jin, D. P.; Jin, S.; Johansson, T.; Julin, A.; Kalantar-Nayestanaki, N.; Kang, X. L.; Kang, X. S.; Kavatsyuk, M.; Ke, B. C.; Kiese, P.; Kliemt, R.; Kloss, B.; Kolcu, O. B.; Kopf, B.; Kornicer, M.; Kupsc, A.; Kühn, W.; Lange, J. S.; Lara, M.; Larin, P.; Leng, C.; Li, C.; Li, Cheng; Li, D. M.; Li, F.; Li, F. Y.; Li, G.; Li, H. B.; Li, H. J.; Li, J. C.; Li, Jin; Li, K.; Li, K.; Li, Lei; Li, P. R.; Li, Q. Y.; Li, T.; Li, W. D.; Li, W. G.; Li, X. L.; Li, X. N.; Li, X. Q.; Li, Y. B.; Li, Z. B.; Liang, H.; Liang, Y. F.; Liang, Y. T.; Liao, G. R.; Lin, D. X.; Liu, B.; Liu, B. J.; Liu, C. X.; Liu, D.; Liu, F. H.; Liu, Fang; Liu, Feng; Liu, H. B.; Liu, H. H.; Liu, H. H.; Liu, H. M.; Liu, J.; Liu, J. B.; Liu, J. P.; Liu, J. Y.; Liu, K.; Liu, K. Y.; Liu, L. D.; Liu, P. L.; Liu, Q.; Liu, S. B.; Liu, X.; Liu, Y. B.; Liu, Z. A.; Liu, Zhiqing; Loehner, H.; Lou, X. C.; Lü, H. J.; Lü, J. G.; Lu, Y.; Lu, Y. P.; Luo, C. L.; Luo, M. X.; Luo, T.; Luo, X. L.; Lü, X. R.; Ma, F. C.; Ma, H. L.; Ma, L. L.; Ma, M. M.; Ma, Q. M.; Ma, T.; Ma, X. N.; Ma, X. Y.; Ma, Y. M.; Maas, F. E.; Maggiora, M.; Mao, Y. J.; Mao, Z. P.; Marcello, S.; Messchendorp, J. G.; Min, J.; Min, T. J.; Mitchell, R. E.; Mo, X. H.; Mo, Y. J.; Morales Morales, C.; Muchnoi, N. Yu.; Muramatsu, H.; Nefedov, Y.; Nerling, F.; Nikolaev, I. B.; Ning, Z.; Nisar, S.; Niu, S. L.; Niu, X. Y.; Olsen, S. L.; Ouyang, Q.; Pacetti, S.; Pan, Y.; Patteri, P.; Pelizaeus, M.; Peng, H. P.; Peters, K.; Pettersson, J.; Ping, J. L.; Ping, R. G.; Poling, R.; Prasad, V.; Qi, H. R.; Qi, M.; Qian, S.; Qiao, C. F.; Qin, L. Q.; Qin, N.; Qin, X. S.; Qin, Z. H.; Qiu, J. F.; Rashid, K. H.; Redmer, C. F.; Ripka, M.; Rong, G.; Rosner, Ch.; Ruan, X. D.; Sarantsev, A.; Savrié, M.; Schoenning, K.; Schumann, S.; Shan, W.; Shao, M.; Shen, C. P.; Shen, P. X.; Shen, X. Y.; Sheng, H. Y.; Shi, M.; Song, W. M.; Song, X. Y.; Sosio, S.; Spataro, S.; Sun, G. X.; Sun, J. F.; Sun, S. S.; Sun, X. H.; Sun, Y. J.; Sun, Y. Z.; Sun, Z. J.; Sun, Z. T.; Tang, C. J.; Tang, X.; Tapan, I.; Thorndike, E. H.; Tiemens, M.; Ullrich, M.; Uman, I.; Varner, G. S.; Wang, B.; Wang, B. L.; Wang, D.; Wang, D. Y.; Wang, K.; Wang, L. L.; Wang, L. S.; Wang, M.; Wang, P.; Wang, P. L.; Wang, W.; Wang, W. P.; Wang, X. F.; Wang, Y.; Wang, Y. D.; Wang, Y. F.; Wang, Y. Q.; Wang, Z.; Wang, Z. G.; Wang, Z. H.; Wang, Z. Y.; Wang, Z. Y.; Weber, T.; Wei, D. H.; Weidenkaff, P.; Wen, S. P.; Wiedner, U.; Wolke, M.; Wu, L. H.; Wu, L. J.; Wu, Z.; Xia, L.; Xia, L. G.; Xia, Y.; Xiao, D.; Xiao, H.; Xiao, Z. J.; Xie, Y. G.; Xiu, Q. L.; Xu, G. F.; Xu, J. J.; Xu, L.; Xu, Q. J.; Xu, Q. N.; Xu, X. P.; Yan, L.; Yan, W. B.; Yan, W. C.; Yan, Y. H.; Yang, H. J.; Yang, H. X.; Yang, L.; Yang, Y. X.; Ye, M.; Ye, M. H.; Yin, J. H.; Yu, B. X.; Yu, C. X.; Yu, J. S.; Yuan, C. Z.; Yuan, W. L.; Yuan, Y.; Yuncu, A.; Zafar, A. A.; Zallo, A.; Zeng, Y.; Zeng, Z.; Zhang, B. X.; Zhang, B. Y.; Zhang, C.; Zhang, C. C.; Zhang, D. H.; Zhang, H. H.; Zhang, H. Y.; Zhang, J.; Zhang, J. J.; Zhang, J. L.; Zhang, J. Q.; Zhang, J. W.; Zhang, J. Y.; Zhang, J. Z.; Zhang, K.; Zhang, L.; Zhang, S. Q.; Zhang, X. Y.; Zhang, Y.; Zhang, Y. H.; Zhang, Y. N.; Zhang, Y. T.; Zhang, Yu; Zhang, Z. H.; Zhang, Z. P.; Zhang, Z. Y.; Zhao, G.; Zhao, J. W.; Zhao, J. Y.; Zhao, J. Z.; Zhao, Lei; Zhao, Ling; Zhao, M. G.; Zhao, Q.; Zhao, Q. W.; Zhao, S. J.; Zhao, T. C.; Zhao, Y. B.; Zhao, Z. G.; Zhemchugov, A.; Zheng, B.; Zheng, J. P.; Zheng, W. J.; Zheng, Y. H.; Zhong, B.; Zhou, L.; Zhou, X.; Zhou, X. K.; Zhou, X. R.; Zhou, X. Y.; Zhu, K.; Zhu, K. J.; Zhu, S.; Zhu, S. H.; Zhu, X. L.; Zhu, Y. C.; Zhu, Y. S.; Zhu, Z. A.; Zhuang, J.; Zotti, L.; Zou, B. S.; Zou, J. H.; BESIII Collaboration

    2016-11-01

    By analyzing 2.93 fb-1 data collected at the center-of-mass energy with the BESIII detector, we measure the absolute branching fraction of the semileptonic decay D+ → K̅0 e+νe to be ℬ(D + → K̅0 e+νe) = (8.59 ± 0.14 ± 0.21)% using , where the first uncertainty is statistical and the second systematic. Our result is consistent with previous measurements within uncertainties.. Supported by National Key Basic Research Program of China (2009CB825204, 2015CB856700), National Natural Science Foundation of China (NSFC) (10935007, 11125525, 11235011, 11305180, 11322544, 11335008, 11425524, 11475123), Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Program, CAS Center for Excellence in Particle Physics (CCEPP), Collaborative Innovation Center for Particles and Interactions (CICPI), Joint Large-Scale Scientific Facility Funds of NSFC and CAS (11179007, U1232201, U1332201, U1532101), CAS (KJCX2-YW-N29, KJCX2-YW-N45), 100 Talents Program of CAS, National 1000 Talents Program of China, INPAC and Shanghai Key Laboratory for Particle Physics and Cosmology, German Research Foundation DFG (Collaborative Research Center CRC-1044), Istituto Nazionale di Fisica Nucleare, Italy, Koninklijke Nederlandse Akademie van Wetenschappen (KNAW) (530-4CDP03), Ministry of Development of Turkey (DPT2006K-120470), National Natural Science Foundation of China (NSFC) (11405046, U1332103), Russian Foundation for Basic Research (14-07-91152), Swedish Resarch Council, U. S. Department of Energy (DE-FG02-04ER41291, DE-FG02-05ER41374, DE-SC0012069, DESC0010118), U.S. National Science Foundation, University of Groningen (RuG) and Helmholtzzentrum fuer Schwerionenforschung GmbH (GSI), Darmstadt, WCU Program of National Research Foundation of Korea (R32-2008-000-10155-0).

  9. Evidence for e+e- →γχc1,2 at center-of-mass energies from 4.009 to 4.360 GeV

    NASA Astrophysics Data System (ADS)

    Ablikim, M.; N. Achasov, M.; Ai, X. C.; Albayrak, O.; Albrecht, M.; J. Ambrose, D.; Amoroso, A.; An, F. F.; An, Q.; Bai, J. Z.; R. Baldini, Ferroli; Ban, Y.; W. Bennett, D.; V. Bennett, J.; Bertani, M.; Bettoni, D.; Bian, J. M.; Bianchi, F.; Boger, E.; Bondarenko, O.; Boyko, I.; A. Briere, R.; Cai, H.; Cai, X.; Cakir, O.; Calcaterra, A.; Cao, G. F.; A. Cetin, S.; Chang, J. F.; Chelkov, G.; Chen, G.; Chen, H. S.; Chen, H. Y.; Chen, J. C.; Chen, M. L.; Chen, S. J.; Chen, X.; Chen, X. R.; Chen, Y. B.; Cheng, H. P.; Chu, X. K.; Cibinetto, G.; Cronin-Hennessy, D.; Dai, H. L.; Dai, J. P.; Dbeyssi, A.; Dedovich, D.; Deng, Z. Y.; Denig, A.; Denysenko, I.; Destefanis, M.; F. De, Mori; Ding, Y.; Dong, C.; Dong, J.; Dong, L. Y.; Dong, M. Y.; Du, S. X.; Duan, P. F.; Fan, J. Z.; Fang, J.; Fang, S. S.; Fang, X.; Fang, Y.; Fava, L.; Feldbauer, F.; Felici, G.; Feng, C. Q.; Fioravanti, E.; Fritsch, M.; Fu, C. D.; Gao, Q.; Gao, Y.; Gao, Z.; Garzia, I.; Goetzen, K.; Gong, W. X.; Gradl, W.; Greco, M.; Gu, M. H.; Gu, Y. T.; Guan, Y. H.; Guo, A. Q.; Guo, L. B.; Guo, T.; Guo, Y.; P. Guo, Y.; Haddadi, Z.; Hafner, A.; Han, S.; Han, Y. L.; A. Harris, F.; He, K. L.; He, Z. Y.; Held, T.; Heng, Y. K.; Hou, Z. L.; Hu, C.; Hu, H. M.; Hu, J. F.; Hu, T.; Hu, Y.; Huang, G. M.; Huang, G. S.; Huang, H. P.; Huang, J. S.; Huang, X. T.; Huang, Y.; Hussain, T.; Ji, Q.; Ji, Q. P.; Ji, X. B.; Ji, X. L.; Jiang, L. L.; Jiang, L. W.; Jiang, X. S.; Jiao, J. B.; Jiao, Z.; Jin, D. P.; Jin, S.; Johansson, T.; Julin, A.; Kalantar-Nayestanaki, N.; Kang, X. L.; Kang, X. S.; Kavatsyuk, M.; C. Ke, B.; Kliemt, R.; Kloss, B.; B. Kolcu, O.; Kopf, B.; Kornicer, M.; Kuehn, W.; Kupsc, A.; Lai, W.; S. Lange, J.; M., Lara; Larin, P.; Li, C. H.; Li, Cheng; Li, D. M.; Li, F.; Li, G.; Li, H. B.; Li, J. C.; Li, Jin; Li, K.; Li, K.; Li, P. R.; Li, T.; Li, W. D.; Li, W. G.; Li, X. L.; Li, X. M.; Li, X. N.; Li, X. Q.; Li, Z. B.; Liang, H.; Liang, Y. F.; Liang, Y. T.; Liao, G. R.; X. Lin(Lin, D.; Liu, B. J.; L. Liu, C.; Liu, C. X.; Liu, F. H.; Liu, Fang; Liu, Feng; Liu, H. B.; Liu, H. H.; Liu, H. H.; Liu, H. M.; Liu, J.; Liu, J. P.; Liu, J. Y.; Liu, K.; Liu, K. Y.; Liu, L. D.; Liu, P. L.; Liu, Q.; Liu, S. B.; Liu, X.; Liu, X. X.; Liu, Y. B.; Liu, Z. A.; Liu, Zhiqiang; Zhiqing, Liu; Loehner, H.; Lou, X. C.; Lu, H. J.; Lu, J. G.; Lu, R. Q.; Lu, Y.; Lu, Y. P.; Luo, C. L.; Luo, M. X.; Luo, T.; Luo, X. L.; Lv, M.; Lyu, X. R.; Ma, F. C.; Ma, H. L.; Ma, L. L.; Ma, Q. M.; Ma, S.; Ma, T.; Ma, X. N.; Ma, X. Y.; E. Maas, F.; Maggiora, M.; A. Malik, Q.; Mao, Y. J.; Mao, Z. P.; Marcello, S.; G. Messchendorp, J.; Min, J.; Min, T. J.; E. Mitchell, R.; Mo, X. H.; Mo, Y. J.; C. Morales, Morales; Moriya, K.; Yu. Muchnoi, N.; Muramatsu, H.; Nefedov, Y.; Nerling, F.; B. Nikolaev, I.; Ning, Z.; Nisar, S.; Niu, S. L.; Niu, X. Y.; Olsen, S. L.; Ouyang, Q.; Pacetti, S.; Patteri, P.; Pelizaeus, M.; Peng, H. P.; Peters, K.; Ping, J. L.; Ping, R. G.; Poling, R.; Pu, Y. N.; Qi, M.; Qian, S.; Qiao, C. F.; Qin, L. Q.; Qin, N.; Qin, X. S.; Qin, Y.; Qin, Z. H.; Qiu, J. F.; H. Rashid, K.; F. Redmer, C.; Ren, H. L.; Ripka, M.; Rong, G.; Ruan, X. D.; Santoro, V.; Sarantsev, A.; Savrié, M.; Schoenning, K.; Schumann, S.; Shan, W.; Shao, M.; Shen, C. P.; Shen, P. X.; Shen, X. Y.; Sheng, H. Y.; R. Shepherd, M.; Song, W. M.; Song, X. Y.; Sosio, S.; Spataro, S.; Spruck, B.; Sun, G. X.; Sun, J. F.; Sun, S. S.; Sun, Y. J.; Sun, Y. Z.; Sun, Z. J.; Sun, Z. T.; Tang, C. J.; Tang, X.; Tapan, I.; H. Thorndike, E.; Tiemens, M.; Toth, D.; Ullrich, M.; Uman, I.; S. Varner, G.; Wang, B.; Wang, B. L.; Wang, D.; Wang, D. Y.; Wang, K.; Wang, L. L.; Wang, L. S.; Wang, M.; Wang, P.; Wang, P. L.; Wang, Q. J.; Wang, S. G.; Wang, W.; Wang, X. F.; D. Wang(Yadi, Y.; Wang, Y. F.; Wang, Y. Q.; Wang, Z.; Wang, Z. G.; Wang, Z. H.; Wang, Z. Y.; Weber, T.; Wei, D. H.; Wei, J. B.; Weidenkaff, P.; Wen, S. P.; Wiedner, U.; Wolke, M.; Wu, L. H.; Wu, Z.; Xia, L. G.; Xia, Y.; Xiao, D.; Xiao, Z. J.; Xie, Y. G.; Xu, G. F.; Xu, L.; Xu, Q. J.; Xu, Q. N.; Xu, X. P.; Yan, L.; Yan, W. B.; Yan, W. C.; Yan, Y. H.; Yang, H. X.; Yang, L.; Yang, Y.; Yang, Y. X.; Ye, H.; Ye, M.; Ye, M. H.; Yin, J. H.; Yu, B. X.; Yu, C. X.; Yu, H. W.; Yu, J. S.; Yuan, C. Z.; Yuan, W. L.; Yuan, Y.; Yuncu, A.; A. Zafar, A.; Zallo, A.; Zeng, Y.; Zhang, B. X.; Zhang, B. Y.; Zhang, C.; Zhang, C. C.; Zhang, D. H.; Zhang, H. H.; Zhang, H. Y.; Zhang, J. J.; Zhang, J. L.; Zhang, J. Q.; Zhang, J. W.; Zhang, J. Y.; Zhang, J. Z.; Zhang, K.; Zhang, L.; Zhang, S. H.; Zhang, X. Y.; Zhang, Y.; Zhang, Y. H.; Zhang, Y. T.; Zhang, Z. H.; Zhang, Z. P.; Zhang, Z. Y.; Zhao, G.; Zhao, J. W.; Zhao, J. Y.; Zhao, J. Z.; Zhao, Lei; Zhao, Ling; Zhao, M. G.; Zhao, Q.; Zhao, Q. W.; Zhao, S. J.; Zhao, T. C.; Zhao, Y. B.; Zhao, Z. G.; Zhemchugov, A.; Zheng, B.; Zheng, J. P.; Zheng, W. J.; Zheng, Y. H.; Zhong, B.; Zhou, L.; Zhou, Li; Zhou, X.; Zhou, X. K.; Zhou, X. R.; Zhou, X. Y.; Zhu, K.; Zhu, K. J.; Zhu, S.; Zhu, X. L.; Zhu, Y. C.; Zhu, Y. S.; Zhu, Z. A.; Zhuang, J.; Zou, B. S.; Zou, J. H.; BESIII Collaboration

    2015-04-01

    Using data samples collected at center-of-mass energies of √s = 4.009, 4.230, 4.260, and 4.360 GeV with the BESIII detector operating at the BEPCII collider, we perform a search for the process e+e- → γχcJ (J=0, 1, 2) and find evidence for e+e- → γχc1 and e+e- → γχc2 with statistical significances of 3.0σ and 3.4σ, respectively. The Born cross sections σB(e+e- → γχcJ), as well as their upper limits at the 90% confidence level (C.L.) are determined at each center-of-mass energy. Supported by National Key Basic Research Program of China (2015CB856700), Joint Funds of National Natural Science Foundation of China (11079008, 11179007, U1232201, U1332201, U1232107), National Natural Science Foundation of China (NSFC) (10935007, 11121092, 11125525, 11235011, 11322544, 11335008), Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Program, CAS (KJCX2-YW-N29, KJCX2-YW-N45), 100 Talents Program of CAS, INPAC and Shanghai Key Laboratory for Particle Physics and Cosmology; German Research Foundation DFG (Collaborative Research Center CRC-1044), Istituto Nazionale di Fisica Nucleare, Italy, Ministry of Development of Turkey (DPT2006K-120470), Russian Foundation for Basic Research (14-07-91152), U. S. Department of Energy (DE-FG02-04ER41291, DE-FG02-05ER41374, DE-FG02-94ER40823, DESC0010118), U.S. National Science Foundation, University of Groningen (RuG) and Helmholtzzentrum fuer Schwerionenforschung GmbH (GSI), Darmstadt, WCU Program of National Research Foundation of Korea (R32-2008-000-10155-0)

  10. Measurements of the center-of-mass energies at BESIII via the di-muon process

    NASA Astrophysics Data System (ADS)

    Ablikim, M.; N. Achasov, M.; C. Ai, X.; Albayrak, O.; Albrecht, M.; J. Ambrose, D.; Amoroso, A.; An, F. F.; An, Q.; Bai, J. Z.; Baldini, Ferroli R.; Ban, Y.; Bennett, D. W.; Bennett, J. V.; Bertani, M.; Bettoni, D.; Bian, J. M.; Bianchi, F.; Boger, E.; Boyko, I.; Briere, R. A.; Cai, H.; Cai, X.; Cakir, O.; Calcaterra, A.; Cao, G. F.; Cetin, S. A.; Chang, J. F.; Chelkov, G.; Chen, G.; Chen, H. S.; Chen, H. Y.; Chen, J. C.; Chen, M. L.; Chen, S. J.; Chen, X.; Chen, X. R.; Chen, Y. B.; Cheng, H. P.; Chu, X. K.; Cibinetto, G.; Dai, H. L.; Dai, J. P.; Dbeyssi, A.; Dedovich, D.; Y. Deng, Z.; Denig, A.; Denysenko, I.; Destefanis, M.; De Mori, F.; Ding, Y.; Dong, C.; Dong, J.; Dong, L. Y.; Dong, M. Y.; Du, S. X.; Duan, P. F.; Fan, J. Z.; Fang, J.; Fang, S. S.; Fang, X.; Fang, Y.; Fava, L.; Feldbauer, F.; Felici, G.; Feng, C. Q.; Fioravanti, E.; Fritsch, M.; Fu, C. D.; Gao, Q.; Gao, X. L.; Gao, X. Y.; Gao, Y.; Gao, Z.; Garzia, I.; Goetzen, K.; Gong, W. X.; Gradl, W.; Greco, M.; Gu, M. H.; Gu, Y. T.; Guan, Y. H.; Guo, A. Q.; Guo, L. B.; Guo, Y.; Guo, Y. P.; Haddadi, Z.; Hafner, A.; Han, S.; Q. Hao, X. Q.; Harris, F. A.; He, K. L.; Held, T.; Heng, Y. K.; Hou, Z. L.; Hu, C.; Hu, H. M.; Hu, J. F.; Hu, T.; Hu, Y.; Huang, G. M.; Huang, G. S.; Huang, J. S.; Huang, X. T.; Huang Y.; Hussain, T.; Ji, Q.; Ji, Q. P.; Ji, X. B.; Ji, X. L.; Jiang, L. W.; Jiang, X. S.; Jiang, X. Y.; Jiao, J. B.; Jiao, Z.; Jin, D. P.; Jin, S.; Johansson, T.; Julin, A.; Kalantar-Nayestanaki, N.; Kang, X. L.; Kang, X. S.; Kavatsyuk, M.; Ke, B. C.; Kiese, P.; Kliemt, R.; Kloss, B.; Kolcu, O. B.; Kopf, B.; Kornicer, M.; Kühn, W.; Kupsc, A.; Lange, J. S.; Lara, M.; Larin, P.; Leng, C.; Li, C.; Cheng, Li; Li, D. M.; Li, F.; Li, F. Y.; Li, G.; Li, H. B.; Li, J. C.; Li, Jin; Li, K.; Li, K.; Li, Lei; Li, P. R.; Li, T.; Li, W. D.; Li, W. G.; Li, X. L.; Li, X. M.; Li, X. N.; Li, X. Q.; Li, Z. B.; Liang, H.; Liang, Y. F.; Liang, Y. T.; Liao, G. R.; Lin, X.; Liu, B. J.; Liu, C. X.; Liu, D.; Liu, F. H.; Fang, Liu; Feng, Liu; Liu, H. B.; Liu, H. H.; Liu, H. H.; Liu, H. M.; Liu, J.; Liu, J. B.; Liu, J. P.; Liu, J. Y.; Liu, K.; Liu, K. Y.; Liu, L. D.; Liu, P. L.; Liu, Q.; Liu, S. B.; Liu, X.; Liu, Y. B.; Liu, Z. A.; Liu, Zhiqing; Loehner, H.; Lou, X. C.; Lu, H. J; Lu, J. G.; Lu, Y.; Lu, Y. P.; Luo, C. L.; Luo, M. X.; Luo, T.; Luo, X. L.; Lyu, X. R.; Ma, F. C.; Ma, H. L.; Ma, L. L.; Ma, Q. M.; Ma, T.; Ma, X. N.; Ma, X. Y.; Maas, F. E.; Maggiora, M.; Mao, Y. Y.; Mao, Z. P.; Marcello, S.; Messchendorp, J. G.; Min, J.; Mitchell, R. E.; Mo, X. H.; Mo, Y. J.; Morales Morales, C.; Moriya, K.; Muchnoi, N. Yu.; Muramatsu, H.; Nefedov, Y.; Nerling, F.; Nikolaev, I. B.; Ning, Z.; Nisar, S.; Niu, S. L.; Niu, X. Y.; Olsen, S. L.; Ouyang, Q.; Pacetti, S.; Pan, Y.; Patteri, P.; Pelizaeus, M.; Peng, H. P.; Peters, K.; Pettersson, J.; Ping, J. L.; Ping, R. G.; Poling, R.; Prasad, V.; Qi, M.; Qian, S.; Qiao, C. F.; Qin, L. Q.; Qin, N.; Qin, X. S.; Qin, Z. H.; Qiu, J. F.; Rashid, K. H.; Redmer, C. F.; Ripka, M.; Rong, G.; Rosner, Ch.; Ruan, X. D.; Santoro, V.; Sarantsev, A. A.; Savrié, M.; Schoenning, B. K.; Schumann, S.; Shan, W.; Shao, M.; Shen, C. P.; Shen, P. X.; Shen, X. Y.; Sheng, H. Y.; Song, W. M.; Song, X. Y.; Sosio, S.; Spataro, S.; Sun, G. X.; Sun, J. F.; Sun, S. S.; Sun, Y. J.; Sun, Y. Z.; Sun, Z. J.; Sun, Z. T.; Tang, C. J.; Tang, X.; Tapan, I.; Thorndike, E. H.; Tiemens, M.; Ullrich, M.; Uman, I.; Varner, G. S.; Wang, B.; Wang, D.; Wang, D. Y.; Wang, K.; Wang, L. L.; Wang, L. S.; Wang, M.; Wang, P.; Wang, P. L.; Wang, S. G.; Wang, W.; Wang, W. P.; Wang, X. F.; Wang, Y. D.; Wang, Y. F.; Wang, Y. Q.; Wang, Z.; Wang, Z. G.; Wang, Z. H.; Wang, Z. Y.; Weber, T.; Wei, D. H.; Wei, J. B.; Weidenkaff, P.; Wen, S. P.; Wiedner, U.; Wolke, M.; Wu, L. H.; Wu, Z.; Xia, L.; Xia, L. G.; Xia, Y.; Xiao, D.; Xiao, H.; Xiao, Z. J.; Xie, Y. G.; Xiu, Q. L.; Xu, G. F.; Xu, L.; Xu, Q. J.; Xu, X. P.; Yan, L.; Yan, W. B.; Yan, W. C.; Yan, Y. H.; Yang, H. J.; Yang, H. X.; Yang, L.; Yang, Y.; Yang, Y. X.; Ye, M.; Ye, M. H.; Yin, J. H.; Yu, B. X.; Yu, C. X.; Yu, J. S.; Yuan, C. Z.; Yuan, W. L.; Yuan, Y.; Yuncu, A.; Zafar, A. A.; Zallo, A.; Zeng, A. Y.; Zeng, Z.; Zhang, B. X.; Zhang, B. Y.; Zhang, C.; Zhang, C. C.; Zhang, D. H.; Zhang, H. H.; Zhang, H. Y.; Zhang, J. J.; Zhang, J. L.; Zhang, J. Q.; Zhang, J. W.; Zhang, J. Y.; Zhang, J. Z.; Zhang, K.; Zhang, L.; Zhang, X. Y.; Zhang, Y.; Zhang, Y. N.; Zhang, Y. H.; Zhang, Y. T.; Zhang, Yu; Zhang, Z. H.; Zhang, Z. P.; Zhang, Z. Y.; Zhao, G.; Zhao, J. W.; Zhao, J. Y.; Zhao, J. Z.; Zhao, Lei; Zhao, Ling; Zhao, M. G.; Zhao, Q.; Zhao, Q. W.; Zhao, S. J.; Zhao, T. C.; Zhao, Y. B.; Zhao, Z. G.; Zhemchugov, A.; Zheng, B.; Zheng, J. P.; Zheng, W. J.; Zheng, Y. H.; Zhong, B.; Zhou, L.; Zhou, X.; Zhou, X. K.; Zhou, X. R.; Zhou, X. Y.; Zhu, K.; Zhu, K. J.; Zhu, S.; , S. H.; Zhu, X. L.; Zhu, Y. C.; Zhu, Y. S.; Zhu, Z. A.; Zhuang, J.; Zotti, L.; Zou, B. S.; Zou, J. H.; BESIII Collaboration

    2016-06-01

    From 2011 to 2014, the BESIII experiment collected about 5 fb-1 data at center-of-mass energies around 4 GeV for the studies of the charmonium-like and higher excited charmonium states. By analyzing the di-muon process e+e- → γISR/FSRμ+μ-, the center-of-mass energies of the data samples are measured with a precision of 0.8 MeV. The center-of-mass energy is found to be stable for most of the time during data taking. Supported by National Key Basic Research Program of China (2015CB856700), National Natural Science Foundation of China (11125525, 11235011, 11322544, 11335008, 11425524, Y61137005C), Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Program, CAS Center for Excellence in Particle Physics (CCEPP), Collaborative Innovation Center for Particles and Interactions (CICPI), Joint Large-Scale Scientific Facility Funds of NSFC and CAS (11179007, U1232201, U1332201), CAS (KJCX2-YW-N29, KJCX2-YW-N45), 100 Talents Program of CAS, National 1000 Talents Program of China, INPAC and Shanghai Key Laboratory for Particle Physics and Cosmology, German Research Foundation DFG (Collaborative Research Center CRC-1044), Istituto Nazionale di Fisica Nucleare, Italy, Ministry of Development of Turkey (DPT2006K-120470), Russian Foundation for Basic Research (14-07-91152), Swedish Research Council, U. S. Department of Energy (DE-FG02-04ER41291, DE-FG02-05ER41374, DE-FG02-94ER40823, DESC0010118), U.S. National Science Foundation, University of Groningen (RuG) and Helmholtzzentrum fuer Schwerionenforschung GmbH (GSI), Darmstadt, WCU Program of National Research Foundation of Korea (R32-2008-000-10155-0).

  11. 3 MV hypervelocity dust accelerator at the Colorado Center for Lunar Dust and Atmospheric Studies

    SciTech Connect

    Shu, Anthony; Horanyi, Mihaly; Kempf, Sascha; Thomas, Evan; Collette, Andrew; Drake, Keith; Northway, Paige; Gruen, Eberhard; Mocker, Anna; Munsat, Tobin; Srama, Ralf; and others

    2012-07-15

    A hypervelocity dust accelerator for studying micrometeorite impacts has been constructed at the Colorado Center for Lunar Dust and Atmospheric Studies (CCLDAS) at the University of Colorado. Based on the Max-Planck-Instituet fuer Kernphysik (MPI-K) accelerator, this accelerator is capable of emitting single particles of a specific mass and velocity selected by the user. The accelerator consists of a 3 MV Pelletron generator with a dust source, four image charge pickup detectors, and two interchangeable target chambers: a large high-vacuum test bed and an ultra-high vacuum impact study chamber. The large test bed is a 1.2 m diameter, 1.5 m long cylindrical vacuum chamber capable of pressures as low as 10{sup -7} torr while the ultra-high vacuum chamber is a 0.75 m diameter, 1.1 m long chamber capable of pressures as low as 10{sup -10} torr. Using iron dust of up to 2 microns in diameter, final velocities have been measured up to 52 km/s. The spread of the dust particles and the effect of electrostatic focusing have been measured using a long exposure CCD and a quartz target. Furthermore, a new technique of particle selection is being developed using real time digital filtering techniques. Signals are digitized and then cross-correlated with a shaped filter, resulting in a suppressed noise floor. Improvements over the MPI-K design, which include a higher operating voltage and digital filtering for detection, increase the available parameter space of dust emitted by the accelerator. The CCLDAS dust facility is a user facility open to the scientific community to assist with instrument calibrations and experiments.

  12. Computer vision sensor for autonomous helicopter hover stabilization

    NASA Astrophysics Data System (ADS)

    Oertel, Carl-Henrik

    1997-06-01

    Sensors for synthetic vision are needed to extend the mission profiles of helicopters. A special task for various applications is the autonomous position hold of a helicopter above a ground fixed or moving target. A computer-vision based system, which is able to observe the helicopter flight state during hover and low speed, based on the detection and tracking of significant but arbitrary features, has been developed by the Institute of Flight Mechanics of DLR Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. The approach is as follows: A CCD camera looks straight downward to the ground and produces an image of the ground view. The digitized video signal is fed into a high performance on- board computer which looks for distinctive features in the image. Any motion of the helicopter results in movements of these patterns in the camera image. By tracking the distinctive features during the succession of incoming images and by the support of inertial sensor data, it is possible to calculate all necessary helicopter state variables, which are needed for a position hold control algorithm. This information is gained from a state variable observer. That means that no additional information about the appearance of the camera view has to be known in advance to achieve autonomous helicopter hover stabilization. The hardware architecture for this image evaluation system mainly consists of several PowerPC processors which communicate with the aid of transputers and an image distribution bus. Feature tracking is performed by a dedicated 2D-correlator subsystem. The paper presents the characteristics of the computer vision sensor and demonstrates its functionality.

  13. Biomes computed from simulated climatologies

    SciTech Connect

    Claussen, M.; Esch, M.

    1994-01-01

    The biome model of Prentice et al. is used to predict global patterns of potential natural plant formations, or biomes, from climatologies simulated by ECHAM, a model used for climate simulations at the Max-Planck-Institut fuer Meteorologie. This study undertaken in order to show the advantage of this biome model in diagnosing the performance of a climate model and assessing effects of past and future climate changes predicted by a climate model. Good overall agreement is found between global patterns of biomes computed from observed and simulated data of present climate. But there are also major discrepancies indicated by a difference in biomes in Australia, in the Kalahari Desert, and in the Middle West of North America. These discrepancies can be traced back to in simulated rainfall as well as summer or winter temperatures. Global patterns of biomes computed from an ice age simulation reveal that North America, Europe, and Siberia should have been covered largely by tundra and taiga, whereas only small differences are for the tropical rain forests. A potential northeast shift of biomes is expected from a simulation with enhanced CO{sub 2} concentration according to the IPCC Scenario A. Little change is seen in the tropical rain forest and the Sahara. Since the biome model used is not capable of predicting chances in vegetation patterns due to a rapid climate change, the latter simulation to be taken as a prediction of chances in conditions favourable for the existence of certain biomes, not as a reduction of a future distribution of biomes. 15 refs., 8 figs., 2 tabs.

  14. Alternative-Fuel Effects on Contrails & Cruise Emissions (ACCESS-2) Flight Experiment

    NASA Technical Reports Server (NTRS)

    Anderson, Bruce E.

    2015-01-01

    Although the emission performance of gas-turbine engines burning renewable aviation fuels have been thoroughly documented in recent ground-based studies, there is still great uncertainty regarding how the fuels effect aircraft exhaust composition and contrail formation at cruise altitudes. To fill this information gap, the NASA Aeronautics Research Mission Directorate sponsored the ACCESS flight series to make detailed measurements of trace gases, aerosols and ice particles in the near-field behind the NASA DC-8 aircraft as it burned either standard petroleum-based fuel of varying sulfur content or a 50:50 blend of standard fuel and a hydro-treated esters and fatty acid (HEFA) jet fuel produced from camelina plant oil. ACCESS 1, conducted in spring 2013 near Palmdale CA, focused on refining flight plans and sampling techniques and used the instrumented NASA Langley HU-25 aircraft to document DC-8 emissions and contrails on five separate flights of approx.2 hour duration. ACCESS 2, conducted from Palmdale in May 2014, engaged partners from the Deutsches Zentrum fuer Luft- und Raumfahrt (DLR) and National Research Council-Canada to provide additional scientific expertise and sampling aircraft (Falcon 20 and CT-133, respectively) with more extensive trace gas, particle, or air motion measurement capability. Eight, muliti-aircraft research flights of 2 to 4 hour duration were conducted to document the emissions and contrail properties of the DC-8 as it 1) burned low sulfur Jet A, high sulfur Jet A or low sulfur Jet A/HEFA blend, 2) flew at altitudes between 6 and 11 km, and 3) operated its engines at three different fuel flow rates. This presentation further describes the ACCESS flight experiments, examines fuel type and thrust setting impacts on engine emissions, and compares cruise-altitude observations with similar data acquired in ground tests.

  15. Peyton's 4-Steps-Approach in comparison: Medium-term effects on learning external chest compression - a pilot study.

    PubMed

    Münster, Tobias; Stosch, Christoph; Hindrichs, Nina; Franklin, Jeremy; Matthes, Jan

    2016-01-01

    Einführung: Die extrakorporale Herzdruckmassage ist eine wichtige Fertigkeit, um ein Minimum der Organdurchblutung bei Patienten/-innen mit Herz-Kreislauf-Stillstand zu gewährleisten, bis weitere medizinische Hilfe geleistet werden kann. Eine Methode um diese Fertigkeit zu vermitteln ist der Ansatz nach Peyton. Dieser besteht aus 4 Schritten: Demonstration, Dekonstruktion, Verständnis und Durchführung. Bezogen auf die kardiopulmonale Reanimation wird eine Überlegenheit dieser Methode gegenüber Anderen angenommen, ist jedoch bisher durch Studien nicht ausreichend gesichert. In unserer Studie haben wir den mittelfristigen Lernerfolg durch die 4-Schritt-Methode nach Peyton („PEY“) mit dem der Modifikation „PMOD“ (4-Schritt-Methode ohne Schritt 3) und dem „STDM“ (Standardmodell, entsprechend der weit verbreiteten Methode „See one Do one“, entspricht der 4-Schritt-Methode ohne Schritt 1 und 3,) anhand von Parametern der Durchführung einer Herzdruckmassage am Modell verglichen.Material und Methoden: Die prospektiv, randomisierte Pilotstudie wurde im Sommersemester 2009 im Kölner Interprofessionellen SkillsLab und Simulationszentrum (KISS) an der Universität zu Köln durchgeführt. Die Probanden (Studierende der Humanmedizin des zweiten und dritten Fachsemesters) nahmen freiwillig an der Studie teil. Die Studierenden wurden in drei parallele Studiengruppen randomisiert, die nach jeweils einer der oben genannten Methoden unterrichtet wurden. Eine Woche sowie fünf bzw. sechs Monate nach Intervention wurden die Probanden in einer objektivierten strukturierten Einzel-Überprüfung bzgl. ihrer Reanimationsfertigkeiten geprüft. Die Ergebnisse der Gruppen wurden hinsichtlich der Parameter Kompressionsfrequenz, Kompressionstiefe, Anteil richtiger Kompressionen sowie Anzahl in einer Checkliste erreichter Items verglichen. Verglichen wurden außerdem Häufigkeitsverteilungen bezogen auf das Umsetzen oder Verfehlen damals geltender Leitlinienempfehlungen

  16. Multidrug-resistant organisms in refugees: prevalences and impact on infection control in hospitals.

    PubMed

    Heudorf, Ursel; Albert-Braun, Sabine; Hunfeld, Klaus-Peter; Birne, Franz-Ulrich; Schulze, Jörg; Strobel, Klaus; Petscheleit, Knut; Kempf, Volkhard A J; Brandt, Christian

    2016-01-01

    Einleitung: Die Flüchtlingssituation ist eine große Herausforderung für das Gesundheitssystem in vielen Ländern Europas, besonders auch in Deutschland. Eine Vielzahl von Daten zur gesundheitlichen Situation von Flüchtlingen (Infektionen, körperliche Erkrankungen und psych(iatr)ische Probleme) und zu deren Prävention (Hygiene und Impfprogramme) sind publiziert. Jedoch sind Daten zu multiresistenten Erregern (MRE) bei Flüchtlingen vergleichsweise rar, obwohl viele Flüchtlinge aus Ländern mit hoher MRE-Prävalenz stammen und/oder auf ihrer Flucht durch Länder mit hoher MRE-Prävalenz gekommen sind. In der vorliegenden Arbeit werden aktuelle Daten zur MRE-Prävalenz von Flüchtlingen bei Aufnahme in Akutkrankenhäuser vorgestellt und die Bedeutung des Aufnahme-Screenings und des Hygiene-Managements in den Krankenhäusern diskutiert. Methoden: Verschiedene Krankenhäuser in der Rhein-Main-Region teilten die Ergebnisse von Aufnahme-Screening-Untersuchungen von Flüchtlingen anonymisiert dem Gesundheitsamt mit. Die Screening-Untersuchungen wurden zwischen Dezember 2015 und März 2016 nach standardisierten und validierten Methoden vorgenommen. Ergebnisse: 9,8% der bei Klinikaufnahme gescreenten Flüchtlinge (32/325) waren mit Methicillin-resistenten Staphylococcus aureus-Stämmen kolonisiert und 23,3% der Flüchtlinge (67/290) wiesen Gram-negative Erreger mit erweitertem Resistenzspektrum gegen β-Laktam-Antibiotika (ESBL) und/oder Enterobakterien mit Resistenz gegen 3 oder 4 Antibiotikagruppen auf (3MRGN: multiresistente Gram-negative Erreger mit Resistenz gegen Penicilline, Cephalosporine und Fluorchinolone; 4MRGN mit Resistenz gegen die genannten Antibiotikagruppen und zusätzlicher Resistenz gegen Carbapeneme; Definition nach KRINKO 2012). Carbapenem-resistente Gram-negative Erreger (CRE) wurden bei 2,1% (6/290) der untersuchten Flüchtlinge gefunden. Diskussion: Die Daten bestätigen zwischen 2014 und 2016 publizierte Studien, in denen Flüchtlinge bei

  17. Soil formation on hard rock with and without cover of Pleistocene periglacial slope deposits in humid-temperate climate of Europe

    NASA Astrophysics Data System (ADS)

    Sauer, Daniela; Schülli-Maurer, Isabelle

    2014-05-01

    mainly of beech, birch, fir, pine, and sorb, blueberry and hair-grass (Deschampsia flexuosa). 4) Cambisol developed from Monzonite This soil has an age of ca. 9,500 years. The thickness of the organic surface layer is 6 cm; the mineral soil comprises an Ah (9 cm), Bw (17 cm) and BC (9 cm) horizon. Vegetation consists mainly of fir, oak, beech, and sorb, blueberry, ferns, grasses and mosses. Geochemical data suggest that the soil has not entirely developed from Monzonite but that the Ah and Bw horizon are mainly composed of a thin layer of beach sediments. The comparison demonstrates the importance of physical weathering under periglacial conditions and formation of PPSD for Holocene soil development on hard rock in central Europe. References: Schilling, W., Wiefel, H. (1962): Jungpleistozäne Periglazialbildungen und ihre regionale Differenzierung in einigen Teilen Thüringens und des Harzes. Geologie, Jg. 11, Heft 4: 393 - 504. Semmel, A. (1964): Junge Schuttdecken in Hessischen Mittelgebirgen. Notitzbl. Hess. L.-Amt Bodenforsch. 92: 275 - 285. Semmel, A. (1968): Studien über den Verlauf jungpleistozäner Formung in Hessen. Frankfurter Geogr. Hefte 45.

  18. Prenatal recruitment of participants for a birth cohort study including cord blood collection: results of a feasibility study in Bremen, Germany.

    PubMed

    Ernst, Sinja Alexandra; Günther, Kathrin; Frambach, Torsten; Zeeb, Hajo

    2015-01-01

    Hintergrund: Geburtskohorten stellen vielversprechende Forschungsansätze dar, um prospektiv unter Life-Course-Perspektive Ursachen und Mechanismen zahlreicher Erkrankungen zu erforschen. Die Entnahme von Bioproben, einschließlich Nabelschnurblutproben, zu verschiedenen Zeitpunkten im Lebensverlauf (insbesondere prä- und perinatal) ist von zentraler Bedeutung für eine direkte Expositionserfassung. Gleichzeitig ist die Entnahme von Bioproben als besonders kritischer Aspekt in epidemiologischen Studien zu betrachten, insbesondere für die Erforschung von pränatalen Expositionen durch umweltbezogene Faktoren und für DNA-Extraktion. Ziele dieser Machbarkeitsstudie zur Ursachenforschung für kindliche Leukämien war die Erstrekrutierung von werdenden Müttern sowie ihren zukünftigen Neugeborenen für eine Geburtskohorte, welche die Entnahme von Blut der Mutter sowie Nabelschnurblut beinhaltet. Übergreifendes Ziel war die Entwicklung von Empfehlungen für eine mögliche nationale Geburtskohorte auf Basis praktischer Erfahrungen.Methoden: Die Machbarkeitsstudie wurde in Bremen im Zeitraum Januar 2012 bis März 2013 durchgeführt. Werdende Mütter wurden um Studienteilnahme gebeten, wenn (i) der geplante Geburtstermin im Erhebungszeitraum lag, (ii) die Entbindung in der kooperierenden Geburtsklinik stattfinden sollte sowie (iii) die Sprachkenntnisse ausreichend waren, um die Studieninhalte zu verstehen und den pränatalen Fragebogen auszufüllen. Blut der Mutter sowie Nabelschnurblut wurde für spätere Forschungsaktivitäten gesammelt und in einer Stammzellbank eingelagert, die bereits eine bestehende Kooperation mit der Geburtsklinik hatte. 22 niedergelassene Gynäkologinnen und Gynäkologen wurden kontaktiert und gebeten werdende Mütter in die Studie einzuschließen. Die Rekrutierung erfolgte im letzten Schwangerschaftsdrittel, entweder im Rahmen der Schwangerenvorsorge bei niedergelassenen Gynäkologinnen oder Gynäkologen oder in der Geburtsklinik

  19. Impact of a modified Broviac maintenance care bundle on bloodstream infections in paediatric cancer patients.

    PubMed

    Furtwängler, Rhoikos; Laux, Carolin; Graf, Norbert; Simon, Arne

    2015-01-01

    Hintergrund: Während der intensiven Chemotherapie sind bei Kindern mit Krebserkrankungen Blutstrominfektionen (BSI) eine potentiell lebensbedrohliche Komplikation. Die meisten Patienten haben einen dauerhaft implantierten oder getunnelten zentralen Venenkatheter (CVAD, z.B. Broviac). Ein verbessertes Protokoll der Erhaltungspflege kann möglicherweise die Rate von BSI senken. Methode: Interventionsstudie zum Nutzen eines modifizierten Präventionsbündels in zwei prospektiven Beobachtungszeiträumen (P1: bis 05-2011; P2: 09-2011 bis 05-2013); prospektive Surveillance aller mikrobiologisch gesicherten BSI. In P2 wurden fertig konfektionierte NaCl 0.9% Spritzen (10 ml) zum Spülen des Broviacs verwendet. Außerdem wurden alle Konnektions- und Zuspritzstellen (Dreiwegehähne) mit Octenidin/Propanol desinfiziert.Ergebnisse: Während P1 wurden 84 Patienten und während P2 81 eingeschlossen. Die beiden Patientenpopulationen zeigten keine signifikanten Unterschiede in Bezug auf das Alter, die Grunderkrankung oder ihren Status (Anteil mit Rezidiv). Praktisch alle CVAD waren Broviac-Katheter. Die mediane Nutzungsdauer lag in P1 bei 192 d (Interquartile-Range (IQR); 110–288 Tage) und in P2 bei 191 d (IQR; 103–270 Tage). In P1 wurden insgesamt 28 BSI bei 22 Patienten diagnostiziert (Inzidenz für mind. 1 BSI 26%), in P2 waren es nur 15 BSI bei 12 Patienten in P2 (Inzidenz 15%). Die entsprechenden Ergebnisse für die Inzidenzdichte lagen bei 0.44 (CI95 0.29–0.62) BSI pro 100 stationäre Patiententage für P1 vs. 0.34 (0.19–0.53) für P2. Die Inzidenzrate (IR) pro 1.000 stationäre Anwendungstage lag bei 7.76 (5.16–10.86) für P1 vs. 4.75 (2.66–7.43) für P2. Während in P1 9 BSI durch CoNS detektiert wurden, waren es in P2 nur 2 (IR 2.49; CI95 0.17–4.17 vs. 0.63; CI95 0.08–1.72). Fazit: Das modifizierte Präventionsbündel führte zu einer Reduktion von BSI bei pädiatrisch onkologischen Patenten mit Broviac Katheter. Wie in einigen Studien U

  20. ROSAT Discovers Unique, Distant Cluster of Galaxies

    NASA Astrophysics Data System (ADS)

    1995-06-01

    measured (by obtaining spectra of the arcs and measuring their redshift). The masses of galaxy clusters are important for the determination, for instance of the mean density and distribution of matter in the universe. This is because these clusters are the most massive, clearly defined objects known and as such trace these parameters in the universe on very large scales. Another possibility to derive the cluster mass is offered by X-ray observations, because the distribution of the hot, X-ray emitting gas traces the gravitational field of the cluster. Recently, in some clusters there has been a discrepancy between the mass determined in this way and that found from gravitational lensing effects. The team of astronomers now hopes that follow-up X-ray observations of RXJ1347.5-1145 will help to solve this puzzle. Moreover, the combination of extremely high X-ray brightness and the possibility to perform a rather accurate mass determination by the gravitational lensing effect makes this particular cluster a truly unique object. In view of the exceptional X-ray brightness, a very high mass is expected. The exact determination will be possible, as soon as spectra have been obtained of the two arcs. Contrary to what is the case in other clusters, this will not be so difficult, due to their unusual brightness and their ideal geometrical configuration. [1] This is a joint Press Release of ESO and the Max-Planck-Society. It is accompanied by a B/W photo. [2] The investigation described in this Press Release is the subject of a Letter to the Editor which will soon appear in the European journal Astronomy & Astrophysics, with the following authors: Sabine Schindler (Max-Planck-Institut fuer Extraterrestrische Physik and Max-Planck-Institut fuer Astrophysik, Garching, Germany), Hans Boehringer, Doris M. Neumann and Ulrich G. Briel (Max-Planck-Institut fuer Extraterrestrische Physik, Garching, Germany), Luigi Guzzo (Osservatorio Astronomico di Brera, Merate, Italy), Guido Chincarini

  1. A Mathematical Physicist's Approach to Virology

    NASA Astrophysics Data System (ADS)

    Twarock, Reidun

    2012-02-01

    The following talk has been given in a special session dedicated to Professor Heinz-Dietrich Doebner at QTS in Prague in August 2011 on the occasion of his 80th birthday. It documents my journey from being a PhD student in Mathematical Physics at the Arnold Sommerfeld Institute in Clausthal under his supervision, to becoming a Professor of Mathematical Biology at the University of York in the UK. I am currently heading an interdisciplinary research group of eight PDRAs and PhDs, focussed on investigating the structures of viruses from a symmetry perspective and unravelling the implications of virus structure on how viruses form and infect their hosts. A central element in my research is my fascination with the development and application of symmetry techniques, which stems from my time in Clausthal when working with Professor Doebner and colleagues. I would like to thank Professor Doebner for these important formative years in Clausthal. Der folgende Vortrag war mein Beitrag zu einer Festsitzung fuer Herrn Professor Heinz-Dietrich Doebner auf der Tagung QTS im August 2011 anläßlich seines achzigsten Geburtstags. Dieser Beitrag dokumentiert, wie sich meine Forschungen aus der Zeit als Doktorandin von Herrn Professor Doebner in Mathematischer Physik am Arnold Sommerfeld Institut in Clausthal weiterentwickelt haben, und zu meiner Professur in Mathematischer Biologie an der Universität York geführt haben. Ich leite dort zur Zeit eine interdisziplinäre Forschungsgruppe von acht Postdocs und Doktoranden, die sich mit der Entwicklung und Anwendung von Symmetrie-Techniken in der Virologie beschäftigt, und insbesondere untersucht, wie sich die Symmetrie-Eigenschaften von Viren auf deren Entstehung und Funktionsweise auswirken. Eine wichtige Vorraussetzung für dieses Forschungsprogramm ist meine Faszination für die Modellierung von Symmetrie-Eigenschaften, die ich während meiner Zusammenarbeit mit Herrn Professor Doebner und Kollegen in Clausthal entwickelt habe

  2. Progress in the GEOROC Database - Fast and Simple Access to Analytical Data by Precompilation

    NASA Astrophysics Data System (ADS)

    Sarbas, B.

    2001-12-01

    The geochemical database GEOROC of the Max-Planck-Institut fuer Chemie in Mainz http://georoc.mpch-mainz.gwdg.de includes the published chemical analyses of samples from Oceanic Islands, Convergent Margins, and Large Igneous Provinces. As a whole, the database comprises about 77,000 whole-rock, 35,000 mineral and 3,000 inclusion analyses published in about 2,800 papers (status Sept. 2001). For the individual tectonic settings, the following numbers of analyses are available: Oceanic Islands - 25,000 whole rocks, 14,000 minerals, 1,500 inclusions Convergent Margins - 20,000 whole rocks, 9,000 minerals, 500 inclusions Large Igneous Provinces - 32,000 whole rocks, 12,000 minerals, 1500 inclusions. Data entry is complete for samples from Oceanic Islands and Oceanic Large Igneous Provinces. Newly published papers are added regularly. Among the Continental Flood Basalts, which comprise 25,000 whole-rock and 12,000 mineral analyses, large and nearly complete datasets are available for the Columbia River, Deccan, Karoo, Paraná, and Siberian Plateau Basalts. Data for Convergent Margins have been added to the database most recently. The database includes, for instance, for the Honshu Arc 3,300, for the Izu-Bonin Arc 1,550, for the Mariana Arc 1,800, for the Kurile Arc 1,400, for the Aleutian Arc 1,500, for the Cascades 500, for the Andes 1,600, for the Lesser Antilles 1,100, and for the Tonga Arc 1,400 whole-rock analyses. For many localities, huge numbers of analyses (more than 2000) are included in the GEOROC database. The selection and compilation of such substantial datasets proved to be difficult and time-consuming when using the web interface of the database. Therefore, we are building precompiled datasets that include all published whole-rock analyses and a fixed set of location and sample metadata for the respective locations. These precompiled datasets are stored as Excel files and can be downloaded easily and rapidly. If multiple element analyses exist for a

  3. Air quality remote sensing over alpine regions with METEOSAT SEVIRI

    NASA Astrophysics Data System (ADS)

    Emili, E.; Popp, C.; Petitta, M.; Riffler, M.; Wunderle, S.

    2009-04-01

    It is well demonstrated that small aerosol particles or particulate matter (PM10 and PM2.5) affect air quality and can have severe effects on human's health. Hence, it is of great interest for public institutions to have an efficient PM monitoring network. In the last decades this data has been provided from ground-based instruments. Moreover, due to the fast development of space-borne remote sensing instruments, we can now be able to take advantage of air pollution measurements from space, which bears the potential to fill up the gap of spatial coverage from ground-based networks. This also improves the capability to assess air pollutants transport properties together with a better implementation in forecasting data assimilation procedures. In this study we examine the possibility of using data from the Spinning Enhanced Visible and Infrared Imager (SEVIRI), on-board of the geostationary Meteosat Second Generation (MSG) platform, to provide PM concentrations values over Switzerland. SEVIRI's high temporal resolution (15 minutes) could be very useful in investigating the daily behaviour of air pollutants and therefore be a good complement to measurements from polar orbiting sensors (e.g. MODIS). Switzerland is of particular interest because of its mountainous orography that hampers pollutants dispersion. Further, major transalpine connection routes, often characterised by high traffic load, act as a significant air pollution source. The south of Switzerland is also occasionally influenced by pollutants transported from the highly industrialised Po Valley in northern Italy. We investigate the existence of a linear relation between the SEVIRI retrieved AOD (Aerosol Optical Depth) and the PM concentration obtained from the ground-based air quality network NABEL (Nationales Beobachtungsnetz fuer Luftfremdstoffe). The temporal trend of this two quantities shows a significant relationship over various locations. The correlation coefficient is in some cases higher than 0

  4. Space Radar Image of Manaus, Brazil

    NASA Technical Reports Server (NTRS)

    1999-01-01

    companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI).

  5. Space Radar Image of Namib Desert in Southern Namib

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This is a C-band, VV polarization radar image of the Namib desert in southern Namibia, near the coast of South West Africa. The image is centered at about 25 degrees South latitude, 15.5 degrees East longitude. This image was one of the first acquired by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) when it was taken on orbit 4 from the shuttle Endeavour on April 9, 1994. The area shown is approximately 78 kilometers by 20 kilometers. The dominant features in the image are complex sand dune patterns formed by the prevailing winds in this part of the Namib desert. The Namib desert is an extremely dry area formed largely because of the influence of the cold Benguela ocean current that flows northward along the coast of Namibia. The bright areas at the bottom of the image are exposed outcrops of Precambrian rocks. This extremely barren area is a region rich in diamonds that through the centuries have washed down from the mountains. The town of Luderitz is located just to the south of the area shown. Spaceborne Imaging Radar-C and X-Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Aumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia

  6. Space Radar Image of Mammoth, California in 3-D

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This is a three-dimensional perspective of Mammoth Mountain, California. This view was constructed by overlaying a Spaceborne Imaging Radar-C (SIR-C) radar image on a U.S. Geological Survey digital elevation map. Vertical exaggeration is 1.87 times. The image is centered at 37.6 degrees north, 119.0 degrees west. It was acquired from the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) onboard space shuttle Endeavour on its 67th orbit on April 13, 1994. In this color representation, red is C-band HV-polarization, green is C-band VV-polarization and blue is the ratio of C-band VV to C-band HV. Blue areas are smooth, and yellow areas are rock out-crops with varying amounts of snow and vegetation. Crowley Lake is in the foreground, and Highway 395 crosses in the middle of the image. Mammoth Mountain is shown in the upper right. Spaceborne Imaging Radar-C and X-Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI).

  7. X-SAR as high-performance interferometric SAR

    NASA Astrophysics Data System (ADS)

    Werner, Marian U.; Schandl, Josef

    1995-11-01

    Space Agency (DARA) and the Italian Space Agency (ASI), with the Deutsche Forshcungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), as the major partner in science, operations, and data processing.

  8. Space Radar Image of Niya ruins, Taklamakan desert

    NASA Technical Reports Server (NTRS)

    1999-01-01

    human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtange-legenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstaltfuer Luft und Raumfahrt e.v.(DLR), the major partner in science, operations and data processing of X-SAR.

  9. Comparison of Biological Effectiveness of Carbon-Ion Beams in Japan and Germany

    SciTech Connect

    Uzawa, Akiko; Ando, Koichi Koike, Sachiko; Furusawa, Yoshiya; Matsumoto, Yoshitaka; Takai, Nobuhiko; Hirayama, Ryoichi; Watanabe, Masahiko; Scholz, Michael; Elsaesser, Thilo; Peschke, Peter

    2009-04-01

    Purpose: To compare the biological effectiveness of 290 MeV/amu carbon-ion beams in Chiba, Japan and in Darmstadt, Germany, given that different methods for beam delivery are used for each. Methods and Materials: Murine small intestine and human salivary gland tumor (HSG) cells exponentially growing in vitro were irradiated with 6-cm width of spread-out Bragg peaks (SOBPs) adjusted to achieve nearly identical beam depth-dose profiles at the Heavy-Ion Medical Accelerator in Chiba, and the SchwerIonen Synchrotron in Darmstadt. Cell kill efficiencies of carbon ions were measured by colony formation for HSG cells and jejunum crypts survival in mice. Cobalt-60 {gamma} rays were used as the reference radiation. Isoeffective doses at given survivals were used for relative biological effectiveness (RBE) calculations and interinstitutional comparisons. Results: Isoeffective D{sub 10} doses (mean {+-} standard deviation) of HSG cells ranged from 2.37 {+-} 0.14 Gy to 3.47 {+-} 0.19 Gy for Chiba and from 2.31 {+-} 0.11 Gy to 3.66 {+-} 0.17 Gy for Darmstadt. Isoeffective D{sub 10} doses of gut crypts after single doses ranged from 8.25 {+-} 0.17 Gy to 10.32 {+-} 0.14 Gy for Chiba and from 8.27 {+-} 0.10 Gy to 10.27 {+-} 0.27 Gy for Darmstadt, whereas isoeffective D{sub 30} doses after three fractionated doses were 9.89 {+-} 0.17 Gy through 13.70 {+-} 0.54 Gy and 10.14 {+-} 0.20 Gy through 13.30 {+-} 0.41 Gy for Chiba and Darmstadt, respectively. Overall difference of RBE between the two facilities was 0-5% or 3-7% for gut crypt survival or HSG cell kill, respectively. Conclusion: The carbon-ion beams at the National Institute of Radiological Sciences in Chiba, Japan and the Gesellschaft fuer Schwerionenforschung in Darmstadt, Germany are biologically identical after single and daily fractionated irradiation.

  10. Color Image of Death Valley, California from SIR-C

    NASA Technical Reports Server (NTRS)

    1999-01-01

    studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI).

  11. GEOROC and GeoReM Databases - Linking Chemical Data and Data Quality

    NASA Astrophysics Data System (ADS)

    Sarbas, B.; Jochum, K. P.; Nohl, U.

    2007-12-01

    Since its introduction in 1999, the geochemical database GEOROC (Geochemistry of Rocks of the Oceans and Continents, http://georoc.mpch-mainz.gwdg.de) of the Max-Planck-Institut fuer Chemie in Mainz established itself as a major online resource available to the scientific community. GEOROC provides geochemical data published for volcanic whole rocks, glasses, minerals and inclusions from ocean islands, large igneous provinces, convergent margins, Archean greenstone belts, rift and intraplate volcanic regions. The database now provides about 300,000 analyses published in about 6,800 papers (status: 07/2007). The web interface of GEOROC allows the selection of samples by bibliographic, tectonic, geographic, petrological as well as chemical criteria. As part of the bibliographic query, the search for the GEOROC Reference Number permits an easier reproduction of published data plots created with the help of the database. A new query based on age information will be added in the near future. The geochemical database GeoReM (Geological and Environmental Reference Materials, http://georem.mpch- mainz.gwdg.de/) for reference materials and isotopic standards includes reference samples from rock powders, glasses, minerals, isotopic standards, river water, and seawater. GeoReM is a relational database with a structure compatible to that of GEOROC and contains published analytical and compilation data (major and trace element concentrations, radiogenic and stable isotope ratios), important metadata about the analytical values, such as uncertainty, uncertainty type, method and laboratory. Sample information and references are also included. Five different queries are now possible: Samples or materials, GeoReM preferred values, chemical criteria, bibliography, and methods and institutions. GeoReM contains more than 1500 geological reference materials and 14000 analyses (status: 07/2007). References available in both databases are linked to each other. It is now possible to get

  12. Determination of the number of J/ψ events with inclusive J/ψ decays

    NASA Astrophysics Data System (ADS)

    Ablikim, M.; Achasov, M. N.; Ai, X. C.; Albayrak, O.; Albrecht, M.; Ambrose, D. J.; Amoroso, A.; An, F. F.; An, Q.; Bai, J. Z.; Baldini Ferroli, R.; Ban, Y.; Bennett, D. W.; Bennett, J. V.; Bertani, M.; Bettoni, D.; Bian, J. M.; Bianchi, F.; Boger, E.; Boyko, I.; Briere, R. A.; Cai, H.; Cai, X.; Cakir, O.; Calcaterra, A.; Cao, G. F.; Cetin, S. A.; Chang, J. F.; Chelkov, G.; Chen, G.; Chen, H. S.; Chen, H. Y.; Chen, J. C.; Chen, M. L.; Chen, S. J.; Chen, X.; Chen, X. R.; Chen, Y. B.; Cheng, H. P.; Chu, X. K.; Cibinetto, G.; Dai, H. L.; Dai, J. P.; Dbeyssi, A.; Dedovich, D.; Deng, Z. Y.; Denig, A.; Denysenko, I.; Destefanis, M.; De Mori, F.; Ding, Y.; Dong, C.; Dong, J.; Dong, L. Y.; Dong, M. Y.; Dou, Z. L.; Du, S. X.; Duan, P. F.; Fan, J. Z.; Fang, J.; Fang, S. S.; Fang, X.; Fang, Y.; Farinelli, R.; Fava, L.; Fedorov, O.; Feldbauer, F.; Felici, G.; Feng, C. Q.; Fioravanti, E.; Fritsch, M.; Fu, C. D.; Gao, Q.; Gao, X. L.; Gao, X. Y.; Gao, Y.; Gao, Z.; Garzia, I.; Goetzen, K.; Gong, L.; Gong, W. X.; Gradl, W.; Greco, M.; Gu, M. H.; Gu, Y. T.; Guan, Y. H.; Guo, A. Q.; Guo, L. B.; Guo, Y.; Guo, Y. P.; Haddadi, Z.; Hafner, A.; Han, S.; Hao, X. Q.; Harris, F. A.; He, K. L.; Held, T.; Heng, Y. K.; Hou, Z. L.; Hu, C.; Hu, H. M.; Hu, J. F.; Hu, T.; Hu, Y.; Huang, G. S.; Huang, J. S.; Huang, X. T.; Huang, Y.; Hussain, T.; Ji, Q.; Ji, Q. P.; Ji, X. B.; Ji, X. L.; Jiang, L. W.; Jiang, X. S.; Jiang, X. Y.; Jiao, J. B.; Jiao, Z.; Jin, D. P.; Jin, S.; Johansson, T.; Julin, A.; Kalantar-Nayestanaki, N.; Kang, X. L.; Kang, X. S.; Kavatsyuk, M.; Ke, B. C.; Kiese, P.; Kliemt, R.; Kloss, B.; Kolcu, O. B.; Kopf, B.; Kornicer, M.; Kupsc, A.; Kühn, W.; Lange, J. S.; Lara, M.; Larin, P.; Leng, C.; Li, C.; Li, Cheng; Li, D. M.; Li, F.; Li, F. Y.; Li, G.; Li, H. B.; Li, J. C.; Li, Jin; Li, K.; Li, K.; Li, Lei; Li, P. R.; Li, Q. Y.; Li, T.; Li, W. D.; Li, W. G.; Li, X. L.; Li, X. N.; Li, X. Q.; Li, Z. B.; Liang, H.; Liang, Y. F.; Liang, Y. T.; Liao, G. R.; Lin, D. X.; Liu, B. J.; Liu, C. X.; Liu, D.; Liu, F. H.; Liu, Fang; Liu, Feng; Liu, H. B.; Liu, H. H.; Liu, H. H.; Liu, H. M.; Liu, J.; Liu, J. B.; Liu, J. P.; Liu, J. Y.; Liu, K.; Liu, K. Y.; Liu, L. D.; Liu, P. L.; Liu, Q.; Liu, S. B.; Liu, X.; Liu, Y. B.; Liu, Z. A.; Liu, Zhiqing; Loehner, H.; Lou, X. C.; Lu, H. J.; Lu, J. G.; Lu, Y.; Lu, Y. P.; Luo, C. L.; Luo, M. X.; Luo, T.; Luo, X. L.; Lyu, X. R.; Ma, F. C.; Ma, H. L.; Ma, L. L.; Ma, Q. M.; Ma, T.; Ma, X. N.; Ma, X. Y.; Ma, Y. M.; Maas, F. E.; Maggiora, M.; Mao, Y. J.; Mao, Z. P.; Marcello, S.; Messchendorp, J. G.; Min, J.; Min, T. J.; Mitchell, R. E.; Mo, X. H.; Mo, Y. J.; Morales Morales, C.; Muchnoi, N. Yu.; Muramatsu, H.; Nefedov, Y.; Nerling, F.; Nikolaev, I. B.; Ning, Z.; Nisar, S.; Niu, S. L.; Niu, X. Y.; Olsen, S. L.; Ouyang, Q.; Pacetti, S.; Pan, Y.; Patteri, P.; Pelizaeus, M.; Peng, H. P.; Peters, K.; Pettersson, J.; Ping, J. L.; Ping, R. G.; Poling, R.; Prasad, V.; Qi, H. R.; Qi, M.; Qian, S.; Qiao, C. F.; Qin, L. Q.; Qin, N.; Qin, X. S.; Qin, Z. H.; Qiu, J. F.; Rashid, K. H.; Redmer, C. F.; Ripka, M.; Rong, G.; Rosner, Ch.; Ruan, X. D.; Santoro, V.; Sarantsev, A.; Savrié, M.; Schoenning, K.; Schumann, S.; Shan, W.; Shao, M.; Shen, C. P.; Shen, P. X.; Shen, X. Y.; Sheng, H. Y.; Song, W. M.; Song, X. Y.; Sosio, S.; Spataro, S.; Sun, G. X.; Sun, J. F.; Sun, S. S.; Sun, Y. J.; Sun, Y. Z.; Sun, Z. J.; Sun, Z. T.; Tang, C. J.; Tang, X.; Tapan, I.; Thorndike, E. H.; Tiemens, M.; Ullrich, M.; Uman, I.; Varner, G. S.; Wang, B.; Wang, B. L.; Wang, D.; Wang, D. Y.; Wang, K.; Wang, L. L.; Wang, L. S.; Wang, M.; Wang, P.; Wang, P. L.; Wang, W.; Wang, W. P.; Wang, X. F.; Wang, Y. D.; Wang, Y. F.; Wang, Y. Q.; Wang, Z.; Wang, Z. G.; Wang, Z. H.; Wang, Z. Y.; Weber, T.; Wei, D. H.; Weidenkaff, P.; Wen, S. P.; Wiedner, U.; Wolke, M.; Wu, L. H.; Wu, Z.; Xia, L.; Xia, L. G.; Xia, Y.; Xiao, D.; Xiao, H.; Xiao, Z. J.; Xie, Y. G.; Xiu, Q. L.; Xu, G. F.; Xu, L.; Xu, Q. J.; Xu, Q. N.; Xu, X. P.; Yan, L.; Yan, W. B.; Yan, W. C.; Yan, Y. H.; Yang, H. J.; Yang, H. X.; Yang, L.; Yang, Y. X.; Ye, M.; Ye, M. H.; Yin, J. H.; Yu, B. X.; Yu, C. X.; Yu, J. S.; Yuan, C. Z.; Yuan, W. L.; Yuan, Y.; Yuncu, A.; Zafar, A. A.; Zallo, A.; Zeng, Y.; Zeng, Z.; Zhang, B. X.; Zhang, B. Y.; Zhang, C.; Zhang, C. C.; Zhang, D. H.; Zhang, H. H.; Zhang, H. Y.; Zhang, J. J.; Zhang, J. L.; Zhang, J. Q.; Zhang, J. W.; Zhang, J. Y.; Zhang, J. Z.; Zhang, K.; Zhang, L.; Zhang, X. Y.; Zhang, Y.; Zhang, Y. H.; Zhang, Y. N.; Zhang, Y. T.; Zhang, Yu; Zhang, Z. H.; Zhang, Z. P.; Zhang, Z. Y.; Zhao, G.; Zhao, J. W.; Zhao, J. Y.; Zhao, J. Z.; Zhao, Lei; Zhao, Ling; Zhao, M. G.; Zhao, Q.; Zhao, Q. W.; Zhao, S. J.; Zhao, T. C.; Zhao, Y. B.; Zhao, Z. G.; Zhemchugov, A.; Zheng, B.; Zheng, J. P.; Zheng, W. J.; Zheng, Y. H.; Zhong, B.; Zhou, L.; Zhou, X.; Zhou, X. K.; Zhou, X. R.; Zhou, X. Y.; Zhu, K.; Zhu, K. J.; Zhu, S.; Zhu, S. H.; Zhu, X. L.; Zhu, Y. C.; Zhu, Y. S.; Zhu, Z. A.; Zhuang, J.; Zotti, L.; Zou, B. S.; Zou, J. H.; BESIII Collaboration

    2017-01-01

    A measurement of the number of J/ψ events collected with the BESIII detector in 2009 and 2012 is performed using inclusive decays of the J/ψ. The number of J/ψ events taken in 2009 is recalculated to be (223.7 ± 1.4) × 106, which is in good agreement with the previous measurement, but with significantly improved precision due to improvements in the BESIII software. The number of J/ψ events taken in 2012 is determined to be (1086.9 ± 6.0) × 106. In total, the number of J/ψ events collected with the BESIII detector is measured to be (1310.6 ± 7.0) × 106, where the uncertainty is dominated by systematic effects and the statistical uncertainty is negligible. Supported by National Key Basic Research Program of China (2015CB856700), National Natural Science Foundation of China (NSFC) (10805053, 11125525, 11175188, 11235011, 11322544, 11335008, 11425524), Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Program, the CAS Center for Excellence in Particle Physics (CCEPP), Collaborative Innovation Center for Particles and Interactions (CICPI), Joint Large-Scale Scientific Facility Funds of NSFC and CAS (11179007, U1232201, U1232107, U1332201), CAS (KJCX2-YW-N29, KJCX2-YW-N45), 100 Talents Program of CAS, INPAC and Shanghai Key Laboratory for Particle Physics and Cosmology, German Research Foundation DFG (Collaborative Research Center CRC-1044), Istituto Nazionale di Fisica Nucleare, Italy; Ministry of Development of Turkey (DPT2006K-120470), Russian Foundation for Basic Research (14-07-91152), U. S. Department of Energy (DE-FG02-04ER41291, DE-FG02-05ER41374, DE-FG02-94ER40823, DESC0010118), U.S. National Science Foundation, University of Groningen (RuG) and the Helmholtzzentrum fuer Schwerionenforschung GmbH (GSI), Darmstadt; WCU Program of National Research Foundation of Korea (R32-2008-000-10155-0)

  13. Radar Image of Galapagos Island

    NASA Technical Reports Server (NTRS)

    1994-01-01

    which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI).

  14. Space Radar Image Isla Isabela in 3-D

    NASA Technical Reports Server (NTRS)

    1999-01-01

    , complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI).

  15. A 2 MV Van de Graaff accelerator as a tool for planetary and impact physics research

    SciTech Connect

    Mocker, Anna; Bugiel, Sebastian; Srama, Ralf; Auer, Siegfried; Baust, Guenter; Matt, Guenter; Otto, Katharina; Colette, Andrew; Drake, Keith; Kempf, Sascha; Munsat, Tobin; Shu, Anthony; Sternovsky, Zoltan; Fiege, Katherina; Postberg, Frank; Gruen, Eberhard; Heckmann, Frieder; Helfert, Stefan; Hillier, Jonathan; Mellert, Tobias; and others

    2011-09-15

    Investigating the dynamical and physical properties of cosmic dust can reveal a great deal of information about both the dust and its many sources. Over recent years, several spacecraft (e.g., Cassini, Stardust, Galileo, and Ulysses) have successfully characterised interstellar, interplanetary, and circumplanetary dust using a variety of techniques, including in situ analyses and sample return. Charge, mass, and velocity measurements of the dust are performed either directly (induced charge signals) or indirectly (mass and velocity from impact ionisation signals or crater morphology) and constrain the dynamical parameters of the dust grains. Dust compositional information may be obtained via either time-of-flight mass spectrometry of the impact plasma or direct sample return. The accurate and reliable interpretation of collected spacecraft data requires a comprehensive programme of terrestrial instrument calibration. This process involves accelerating suitable solar system analogue dust particles to hypervelocity speeds in the laboratory, an activity performed at the Max Planck Institut fuer Kernphysik in Heidelberg, Germany. Here, a 2 MV Van de Graaff accelerator electrostatically accelerates charged micron and submicron-sized dust particles to speeds up to 80 km s{sup -1}. Recent advances in dust production and processing have allowed solar system analogue dust particles (silicates and other minerals) to be coated with a thin conductive shell, enabling them to be charged and accelerated. Refinements and upgrades to the beam line instrumentation and electronics now allow for the reliable selection of particles at velocities of 1-80 km s{sup -1} and with diameters of between 0.05 {mu}m and 5 {mu}m. This ability to select particles for subsequent impact studies based on their charges, masses, or velocities is provided by a particle selection unit (PSU). The PSU contains a field programmable gate array, capable of monitoring in real time the particles' speeds and

  16. Characterization of radioactive wastes with respect to harmful materials

    SciTech Connect

    Kugel, Karin; Steyer, Stefan; Brennecke, Peter; Gruendler, Detlef; Boetsch, Wilma; Haider, Claudia

    2013-07-01

    In addendum 4 to the license of the German KONRAD repository, which considers mainly radiological aspects, a water law permit was issued in order to prevent the pollution of the near-surface groundwater. The water law permit stipulates limitations for 10 radionuclides and 2 groups of radionuclides as well as mass limitations for 94 substances and materials relevant for water protection issues. Two collateral clauses, i.e. additional requirements imposed by the licensing authority, include demands on the monitoring, registering and balancing of non-radioactive harmful substances and materials /1/. In order to fulfill the requirements of the water law permit the German Federal Office for Radiation Protection (BfS) being the operator of the KONRAD repository has developed a concept, which ensures the compliance with all requirements of the water law permit and which provides standardized easy manageable guidance for the waste producers to describe their wastes. On 15 March 2011 the competent water authority, the 'Niedersaechsischer Landesbetrieb fuer Wasserwirtschaft, Kuesten- und Naturschutz' (NLWKN) issued the approval for this concept. Being the most essential part of this concept the procedural method and the developed description of nonradioactive waste package constituents by use of standardized lists of materials and containers is addressed and presented in this paper. The waste producer has to describe his waste package in a standardized way on the base of the lists of materials and containers. For each material in the list a comprehensive description is given comprising the composition, scope of application, quality control measures, thresholds and other data. Each entry in the list has to be approved by NLWKN. The scope of the lists is defined by the waste producers' needs. Using some particular materials as examples, the approval procedure for including materials in the list is described. The procedure of describing the material composition has to be

  17. Determination of the k{sub Q{sub c{sub l{sub i{sub n,Q{sub m{sub s{sub r}{sup f{sub c}{sub l}{sub i}{sub n},f{sub m}{sub s}{sub r}}}}}}}}} correction factors for detectors used with an 800 MU/min CyberKnife{sup ®} system equipped with fixed collimators and a study of detector response to small photon beams using a Monte Carlo method

    SciTech Connect

    Moignier, C. Huet, C.; Makovicka, L.

    2014-07-15

    Purpose: In a previous work, output ratio (OR{sub det}) measurements were performed for the 800 MU/min CyberKnife{sup ®} at the Oscar Lambret Center (COL, France) using several commercially available detectors as well as using two passive dosimeters (EBT2 radiochromic film and micro-LiF TLD-700). The primary aim of the present work was to determine by Monte Carlo calculations the output factor in water (OF{sub MC,w}) and the k{sub Q{sub c{sub l{sub i{sub n,Q{sub m{sub s{sub r}{sup f{sub c}{sub l}{sub i}{sub n},f{sub m}{sub s}{sub r}}}}}}}}} correction factors. The secondary aim was to study the detector response in small beams using Monte Carlo simulation. Methods: The LINAC head of the CyberKnife{sup ®} was modeled using the PENELOPE Monte Carlo code system. The primary electron beam was modeled using a monoenergetic source with a radial gaussian distribution. The model was adjusted by comparisons between calculated and measured lateral profiles and tissue-phantom ratios obtained with the largest field. In addition, the PTW 60016 and 60017 diodes, PTW 60003 diamond, and micro-LiF were modeled. Output ratios with modeled detectors (OR{sub MC,det}) and OF{sub MC,w} were calculated and compared to measurements, in order to validate the model for smallest fields and to calculate k{sub Q{sub c{sub l{sub i{sub n,Q{sub m{sub s{sub r}{sup f{sub c}{sub l}{sub i}{sub n},f{sub m}{sub s}{sub r}}}}}}}}} correction factors, respectively. For the study of the influence of detector characteristics on their response in small beams; first, the impact of the atomic composition and the mass density of silicon, LiF, and diamond materials were investigated; second, the material, the volume averaging, and the coating effects of detecting material on the detector responses were estimated. Finally, the influence of the size of silicon chip on diode response was investigated. Results: Looking at measurement ratios (uncorrected output factors) compared to the OF{sub MC,w}, the PTW 60016

  18. Space Radar Image of Mammoth Mountain, California

    NASA Technical Reports Server (NTRS)

    1994-01-01

    cover and alpine glaciers are critical to the radiation and water balances. SIR-C/X-SAR is a powerful tool because it is sensitive to most snowpack conditions and is less influenced by weather conditions than other remote sensing instruments, such as Landsat. In parallel with the operational SIR-C data processing, an experimental effort is being conducted to test SAR data processing using the Jet Propulsion Laboratory's massively parallel supercomputing facility, centered around the Cray Research T3D. These experiments will assess the abilities of large supercomputers to produce high throughput SAR processing in preparation for upcoming data-intensive SAR missions. The images released here were produced as part of this experimental effort. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V.(DLR), the major partner in science, operations and data processing of X-SAR.

  19. Space Radar Image of San Rafael Glacier, Chile

    NASA Technical Reports Server (NTRS)

    1994-01-01

    means. Spaceborne Imaging Radar-C and X-Synthetic Aperture Radar (SIR-C/X-SAR) are part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm), and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes that are caused by nature and those changes that are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.v.(DLR), the major partner in science, operations and data processing of X-SAR.

  20. Space Radar Image of Mount Pinatubo Volcano, Philippines

    NASA Technical Reports Server (NTRS)

    1994-01-01

    radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V.(DLR), the major partner in science, operations and data processing of X-SAR.