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Sample records for 28si 48ca und

  1. Isoscalar giant resonances in {sup 48}Ca

    SciTech Connect

    Lui, Y.-W.; Youngblood, D. H.; Shlomo, S.; Chen, X.; Tokimoto, Y.; Krishichayan,; Anders, M.; Button, J.

    2011-04-15

    The giant resonance region from 9.5 MeV < E{sub x} < 40 MeV in {sup 48}Ca has been studied with inelastic scattering of 240-MeV {alpha} particles at small angles, including 0 deg. 95{sub -15}{sup +11}% of E0 energy-weighted sum rule (EWSR), 83{sub -16}{sup +10}% of E2 EWSR, and 137 {+-} 20% of E1 EWSR were located below E{sub x}=40 MeV. A comparison of the experimental data with calculated results for the isoscalar giant monopole resonance, obtained within the mean-field-based random-phase approximation, is also given.

  2. Inelastic electron scattering from 48Ca

    NASA Astrophysics Data System (ADS)

    Wise, J. E.; McCarthy, J. S.; Altemus, R.; Norum, B. E.; Whitney, R. R.; Heisenberg, J.; Dawson, J.; Schwentker, O.

    1985-05-01

    Inelastic electron scattering from 48Ca has been performed over a momentum transfer range from 0.6 to 3.0 fm-1 in both forward and backward directions. Form factors have been obtained for 25 levels up to 10 MeV excitation. Charge and current densities for 11 low lying electric transitions and current densities for two magnetic transitions have been reconstructed in Fourier Bessel analysis. Three high spin states observed in the region of 9 MeV excitation are found to have the dominant configuration ν(1g9/2,1f-17/2)8 - but with a total strength of only 36% predicted for the first 8- in a random-phase-approximation calculation. This is interpreted as evidence for particle-phonon coupling. Comparisons of the extracted densities are made with random-phase-approximation calculations using a zero-range, density-dependent Migdal interaction.

  3. {sup 48}Ca HETEROGENEITY IN DIFFERENTIATED METEORITES

    SciTech Connect

    Chen, Hsin-Wei; Lee, Typhoon; Lee, Der-Chuen; Shen, Jason Jiun-San; Chen, Jiang-Chang

    2011-12-10

    Isotopic heterogeneities of {sup 48}Ca have been found in numerous bulk meteorites that are correlated with {sup 50}Ti and {sup 54}Cr anomalies among differentiated planetary bodies, and the results suggest that a rare subset of neutron-rich Type Ia supernova (nSN Ia) was responsible for contributing these neutron-rich iron-group isotopes into the solar system (SS). The heterogeneity of these isotopes found in differentiated meteorites indicates that the isotopic compositions of the bulk SS are not uniform, and there are significant amounts of nSNe Ia dust incompletely mixed with the rest of SS materials during planetary formation. Combined with the data of now-extinct short-lived nuclide {sup 60}Fe, which can be produced more efficiently from an nSN Ia than a Type II supernova ejecta, the observed planetary-scale isotopic heterogeneity probably reflects a late input of stellar dust grains with neutron-rich nuclear statistical equilibrium nuclides into the early SS.

  4. Electromagnetic dissociation of relativistic [sup 28]Si by nucleon emission

    SciTech Connect

    Sonnadara, U.J.

    1992-12-01

    A detailed study of the electromagnetic dissociation of [sup 28]Si by nucleon emission at E[sub lab]/A = 14.6 (GeV/nucleon was carried out with [sup 28]Si beams interacting on [sup 208]Pb). [sup 120]Sn. [sup 64]C targets. The measurements apparatus consists of detectors in the target area which measure the energy and charged multiplicity, and a forward spectrometer which measures the position, momentum and energy of the reaction fragments. The exclusive electromagnetic dissociation cross sections for decay channels having multiple nucleons in the final state have been measured which enables the selection of events produced in pure electromagnetic interactions. The measured cross sections agree well with previous measurements obtained for the removal of a few nucleons as well as with measurements on total charge removal cross sections from other experiments. The dependence of the integrated cross sections on the target charge Z[sub T] and the target mass AT confirms that for higher Z targets the excitation is largely electromagnetic. Direct measurements of the excitation energy for the electromagnetic dissociation of [sup 28]Si [yields] p+[sup 27]Al and [sup 28]Si [yields] n+[sup 27]Si have been obtained through a calculation of the invariant mass in kinematically, reconstructed events. The excitation energy spectrum for all targets peak near the isovector giant dipole resonance in [sup 28]Si. These distributions are well reproduced by combining the photon spectrum calculated using the Weizsaecker-Williams approximation with the experimental data on the photonuclear [sup 28]Si([sub [gamma],p])[sup 27]Al and [sup 28]Si([sub [gamma],n])[sup 27]Si. The possibilities of observing double giant dipole resonance excitations in [sup 28]Si have been investigated with cross section measurements as well as with excitation energy reconstruction.

  5. Electromagnetic dissociation of relativistic {sup 28}Si by nucleon emission

    SciTech Connect

    Sonnadara, U.J.

    1992-12-01

    A detailed study of the electromagnetic dissociation of {sup 28}Si by nucleon emission at E{sub lab}/A = 14.6 (GeV/nucleon was carried out with {sup 28}Si beams interacting on {sup 208}Pb). {sup 120}Sn. {sup 64}C targets. The measurements apparatus consists of detectors in the target area which measure the energy and charged multiplicity, and a forward spectrometer which measures the position, momentum and energy of the reaction fragments. The exclusive electromagnetic dissociation cross sections for decay channels having multiple nucleons in the final state have been measured which enables the selection of events produced in pure electromagnetic interactions. The measured cross sections agree well with previous measurements obtained for the removal of a few nucleons as well as with measurements on total charge removal cross sections from other experiments. The dependence of the integrated cross sections on the target charge Z{sub T} and the target mass AT confirms that for higher Z targets the excitation is largely electromagnetic. Direct measurements of the excitation energy for the electromagnetic dissociation of {sup 28}Si {yields} p+{sup 27}Al and {sup 28}Si {yields} n+{sup 27}Si have been obtained through a calculation of the invariant mass in kinematically, reconstructed events. The excitation energy spectrum for all targets peak near the isovector giant dipole resonance in {sup 28}Si. These distributions are well reproduced by combining the photon spectrum calculated using the Weizsaecker-Williams approximation with the experimental data on the photonuclear {sup 28}Si({sub {gamma},p}){sup 27}Al and {sup 28}Si({sub {gamma},n}){sup 27}Si. The possibilities of observing double giant dipole resonance excitations in {sup 28}Si have been investigated with cross section measurements as well as with excitation energy reconstruction.

  6. Lebensdauermessungen an Resonanzzuständen im 28Si-Compoundkern mittels Schatten-Effekt

    NASA Astrophysics Data System (ADS)

    Otto, G.; Zschau, E.; Al-Khafaji, A.

    Unter Anwendung des Schatten-Effektes und der Resonanzreaktion 27Al(p, ) 24Mg an einkristallinen, dicken Al-Targets wurden für drei Resonanzenergien Ep(keV) die Lebensdauern (as) der entsprechenden Anregungszustände E (MeV) des Compoundkernes 28Si gemessen und die zugehörigen Breiten γ(eV) berechnet: [Normal View 0K | Magnified View 12K] Als Target dienten 110-orientierte Al-Einkristalle. Die Registierung der α-Teilchen erfolgte mit großflächigen Festkörperspurdetektoren. Aufgenommen wurden die Winkelverteilungen der α-Teilchen um zwei 110-Achsen des Al-Targets, die zur Einschußrichtung der Protonen unter 75° bzw. -165° einjustiert waren. Zur Auswertung wurden die Differenzen der Minimumausbeuten xmin = xmin ( = 75°) - xmin ( = -165°) und die Verhältnisse der Dip-Volumina R = E( = 75°)/N( = -165°) (bis 70% der Randomausbeute) herangezogen.Translated AbstractLifetime Measurements on Resonant States of 28Si-Compound Nucleus using the Blocking-EffectThe crystal blocking technique has been used to measure the lifetimes of following three levels in the 28Si compound nuclei: 12,901 MeV, 2+; 12,974 MeV, 1- and 13,173 MeV, 3- excited in the 27Al(p, α)24Mg resonance reaction at Ep = 1365 keV, 1439 keV and 1647 keV, respectively. The 110 axial blocking effect in thick Al single crystals has been investigated. Two methods of extracting the lifetime, involving analytical calculations, are compared. The results obtained from both methods of analysis agree, the avarage values of the lifetimes are <1 as, (9+/-4) as and (18+/-5) as, respectively.

  7. ELECTRON-CAPTURE SUPERNOVAE AS ORIGIN OF {sup 48}Ca

    SciTech Connect

    Wanajo, Shinya; Janka, Hans-Thomas; Mueller, Bernhard

    2013-04-20

    We report that electron-capture supernovae (ECSNe), arising from collapsing oxygen-neon-magnesium cores, are a possible source of {sup 48}Ca, whose origin has remained a longstanding puzzle. Our two-dimensional, self-consistent explosion model of an ECSN predicts ejection of neutron-rich matter with electron fractions Y{sub e} Almost-Equal-To 0.40-0.42 and relatively low entropies, s Almost-Equal-To 13-15 k{sub B} per nucleon (k{sub B} is the Boltzmann constant). Post-processing nucleosynthesis calculations result in appreciable production of {sup 48}Ca in such neutron-rich and low-entropy matter during the quasi-nuclear equilibrium and subsequent freezeout phases. The amount of ejected {sup 48}Ca can account for that in the solar inventory when we consider possible uncertainties in the entropies. ECSNe could thus be a site of {sup 48}Ca production in addition to a hypothetical, rare class of high-density Type Ia supernovae.

  8. Mass Spectrometric Investigation of Silicon Extremely Enriched in (28)Si: From (28)SiF4 (Gas Phase IRMS) to (28)Si Crystals (MC-ICP-MS).

    PubMed

    Pramann, Axel; Rienitz, Olaf

    2016-06-07

    A new generation of silicon crystals even further enriched in (28)Si (x((28)Si) > 0.999 98 mol/mol), recently produced by companies and institutes in Russia within the framework of a project initiated by PTB, were investigated with respect to their isotopic composition and molar mass M(Si). A modified isotope dilution mass spectrometric (IDMS) method treating the silicon as the matrix containing a so-called virtual element (VE) existing of the isotopes (29)Si and (30)Si solely and high resolution multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) were applied in combination. This method succeeds also when examining the new materials holding merely trace amounts of (29)Si (x((29)Si) ≈ 5 × 10(-6) mol/mol) and (30)Si (x((30)Si) ≈ 7 × 10(-7) mol/mol) extremely difficult to detect with lowest uncertainty. However, there is a need for validating the enrichment in (28)Si already in the precursor material of the final crystals, silicon tetrafluoride (SiF4) gas prior to crystal production. For that purpose, the isotopic composition of selected SiF4 samples was determined using a multicollector magnetic sector field gas-phase isotope ratio mass spectrometer. Contaminations of SiF4 by natural silicon due to storing and during the isotope ratio mass spectrometry (IRMS) measurements were observed and quantified. The respective MC-ICP-MS measurements of the corresponding crystal samples show-in contrast-several advantages compared to gas phase IRMS. M(Si) of the new crystals were determined to some extent with uncertainties urel(M) < 1 × 10(-9). This study presents a clear dependence of the uncertainty urel(M(Si)) on the degree of enrichment in (28)Si. This leads to a reduction of urel(M(Si)) during the past decade by almost 3 orders of magnitude and thus further reduces the uncertainty of the Avogadro constant NA which is one of the preconditions for the redefinition of the SI unit kilogram.

  9. The coefficient of thermal expansion of highly enriched 28Si

    NASA Astrophysics Data System (ADS)

    Bartl, Guido; Nicolaus, Arnold; Kessler, Ernest; Schödel, René; Becker, Peter

    2009-10-01

    For the new definition of the SI unit of mass based on a fundamental constant, a redetermination of Avogadro's constant is the goal of an international collaboration of numerous national laboratories and universities. Since a relative uncertainty of about 2 × 10-8 is aimed at, the macroscopic density, the isotopic composition and the volume of the unit cell of a silicon single crystal have to be measured with high precision. One step to improve the precision was the production of a silicon crystal of highly enriched 28Si. This paper addresses the effect of thermal expansion of that material in order to account for a possible discrepancy between the coefficient of thermal expansion (CTE) of natural silicon and that of 28Si. The results of two independent CTE measuring methods are presented and compared in this paper.

  10. Pion interferometry in {sup 28}Si + Pb central collisions

    SciTech Connect

    Xu, Nu; E814 Collaboration: BNL-GSI-McGill Univ.-Univ. of Pittsburg-SUNY Stony Brook-Univ. of Sao Paulo-Wayne State Univ.-Yale Univ.

    1994-08-01

    Two-pion correlation functions have been studied using the E814 apparatus in 14.6 A{center_dot}GeV/c {sup 28}Si + Pb central collisions. Results of the correlation functions for pions from the RQMD event generator are compared to the data and show that a source with RMS radius of 8.3 fm is compartable with the experimental data.

  11. CANDLES for the study of ^48Ca double beta decay

    NASA Astrophysics Data System (ADS)

    Ogawa, Izumi

    2009-10-01

    CANDLES is the project to search for double beta decay (DBD) of ^48Ca by using CaF2 scintillators. The Q-value of ^48Ca, which is the highest (4.27 MeV) among potential DBD nuclei, is far above energies of γ-rays from natural radioactivities (maximum 2.615 MeV from ^208Tl decay), therefore we can naturally expect small backgrounds in the energy region we are interested in. We gave the best lower limit on the half-life of neutrino-less double beta decay of ^48Ca by using CaF2(Eu) detector system, ELEGANT VI though further development is highly desirable to reach the mass region of current interest. We have constructed the prototype detector, CANDLES III in our laboratory (Osaka U.) at sea level and studied the basic performance of the system, including the light collection, position reconstruction and background rejection. We are now moving the detector system to new experimental room (room D) at Kamioka underground laboratory (2700 m.w.e.) to avoid large background originated from cosmic rays. At the same time, we are increasing the total mass of the ^48Ca compared to the one in the prototype detector. 96 (instead of 60 in prototype) CaF2 modules which contains 350 g of ^48Ca are immersed in a liquid scintillator (LS) which acts as an active veto (veto phase). The conversion phase contains wavelength shifter (Bis-MSB) which converts the emission light of CaF2(pure) which has a peak in the UV region to the visible one where the quantum efficiency of the PMTs is high enough (maximum at ˜400 nm) and materials at the optical path have good transparencies. Scintillation lights from both the CaF2 modules and the liquid scintillator in veto phase are viewed by large PMTs (48 x13'' and 14 x17'' tubes). All the detector system described above are contained in a water tank which is 3 m in diameter and 4 m in height. The water tank and a purification system of the LS together with LS storage tanks were installed at room D. The purification system of the LS removes the

  12. Isoscalar giant resonance strength in {sup 28}Si

    SciTech Connect

    Youngblood, D. H.; Lui, Y.-W.; Clark, H. L.

    2007-08-15

    Data taken previously covering the giant resonance region from 9 MeV 28}Si with inelastic scattering of 240 MeV {alpha} particles at small angles including 0 deg. have been reanalyzed. Treating all of the observed cross section as multipole processes, giant resonance peaks containing 74 {+-} 7% of the isoscalar E0 energy weighted sum rule (EWSR), 102 {+-} 11% of the E2 EWSR, and 84 {+-} 8% of the E3 EWSR were identified.

  13. Preliminary results of the 249Cf + 48Ca experiment

    SciTech Connect

    Patin, J B; Moody, K J; Stoyer, M A; Wild, J F; Shaughnessy, D A; Stoyer, N J

    2003-11-03

    The results of a detailed analysis performed on the data obtained in the {sup 249}Cf + {sup 48}Ca bombardment is presented. This analysis is independent of the original data analysis performed in Dubna in which two possible decay chains were found. The first decay chain consisted of an evaporation residue implantation followed by two alpha decays and then a spontaneous fission. The second decay chain consisted of an evaporation residue implantation followed by an immediate spontaneous fission event. This analysis confirms that the two interesting events are present in the data. A summary of the two events will be given as well as a description of the analysis performed.

  14. Isospin properties of electric dipole excitations in 48Ca

    NASA Astrophysics Data System (ADS)

    Derya, V.; Savran, D.; Endres, J.; Harakeh, M. N.; Hergert, H.; Kelley, J. H.; Papakonstantinou, P.; Pietralla, N.; Ponomarev, V. Yu.; Roth, R.; Rusev, G.; Tonchev, A. P.; Tornow, W.; Wörtche, H. J.; Zilges, A.

    2014-03-01

    Two different experimental approaches were combined to study the electric dipole strength in the doubly-magic nucleus 48Ca below the neutron threshold. Real-photon scattering experiments using bremsstrahlung up to 9.9 MeV and nearly mono-energetic linearly polarized photons with energies between 6.6 and 9.51 MeV provided strength distribution and parities, and an (α,α‧γ) experiment at Eα=136 MeV gave cross sections for an isoscalar probe. The unexpected difference observed in the dipole response is compared to calculations using the first-order random-phase approximation and points to an energy-dependent isospin character. A strong isoscalar state at 7.6 MeV was identified for the first time supporting a recent theoretical prediction.

  15. Elastic and inelastic scattering of 240-MeV {sup 6}Li ions from {sup 40}Ca and {sup 48}Ca and tests of a systematic optical potential

    SciTech Connect

    Krishichayan,; Chen, X.; Lui, Y.-W.; Button, J.; Youngblood, D. H.

    2010-04-15

    Elastic and inelastic scattering of 240-MeV {sup 6}Li particles from {sup 40}Ca and {sup 48}Ca were measured with the multipole-dipole-multipole spectrometer from 4 deg. <=theta{sub c.m.}<=40 deg. Optical potential parameters were obtained by fitting the elastic-scattering data with the double-folding model using the density-dependent M3Y NN effective interaction and B(E2) and B(E3) values obtained for low-lying 2{sup +} and 3{sup -} states agreed with the adopted values. The results are compared with those obtained using potentials derived from the systematics of potentials previously obtained for {sup 24}Mg, {sup 28}Si, {sup 58}Ni, and {sup 90}Zr. Cross sections for excitation of giant resonances were also calculated with the potentials obtained.

  16. BACKWARD ANGLE STRUCTURE IN THE 20Ne+28Si QUASIELASTIC SCATTERING

    NASA Astrophysics Data System (ADS)

    Sgouros, O.; Soukeras, V.; Pakou, A.; Patronis, N.; Zerva, K.; Keeley, N.; Strojek, I.; Trzcińska, A.; Piasecki, E.; Rusek, K.; Stiliaris, E.; Mazzocco, M.

    2013-10-01

    New data for the quasielastic scattering of 20Ne from a 28Si target at incident energies of 42.5 MeV and 52.3 MeV and for the 28Si(20Ne, 24Mg)24Mg, 28Si(20Ne, 16O)32S and 28Si(20Ne, 12C)36Ar transfer reactions at 52.3 MeV are reported. Oscillations are observed in the backward angle quasielastic scattering data at 52.3 MeV and the 28Si(20Ne, 12C)36Ar transfer cross-sections are of the same magnitude as those for single-α stripping. Coupled reaction channels (CRC) calculations are unable to describe either the quasielastic or the 28Si(20Ne, 12C)36Ar transfer data assuming a sequential α transfer process with α-particle form factors from the literature. The addition of direct 8Be cluster transfer can provide a reasonable description of both data sets, but only with much larger spectroscopic factors than suggested by simple structure calculations or the large 8Be emission thresholds of 20Ne, 28Si and 36Ar, suggesting that the observed structure is of resonance-like origin. An optical model analysis of the quasielastic scattering data is also reported.

  17. New Results for Elements 115, 117, and 118 Produced in the Reactions 243Am+48Ca and 249BK/249Cf+48Ca

    NASA Astrophysics Data System (ADS)

    Utyonkov, V. K.; Oganessian, Yu. Ts.; Abdullin, F. Sh.; Alexander, C.; Binder, J.; Boll, R. A.; Dmitriev, S. N.; Ezold, J.; Felker, K.; Gostic, J. M.; Grzywacz, R. K.; Hamilton, J. H.; Henderson, R. A.; Itkis, M. G.; Miernik, K.; Miller, D.; Moody, K. J.; Polyakov, A. N.; Ramayya, A. V.; Roberto, J. B.; Ryabinin, M. A.; Rykaczewski, K. P.; Sagaidak, R. N.; Shaughnessy, D. A.; Shirokovsky, I. V.; Shumeiko, M. V.; Stoyer, M. A.; Stoyer, N. J.; Subbotin, V. G.; Sukhov, A. M.; Tsyganov, Yu. S.; Voinov, A. A.; Vostokin, G. K.

    2014-09-01

    The reactions of 243Am and 249Bk with 48Ca have been reinvestigated to provide new evidence for the discovery of elements 113, 115, and 117. Three isotopes 287-289115 were synthesized in the 243Am+48Ca reactions at five projectile energies, providing excitation functions and α-decay spectra of the produced isotopes. Decay properties of 287,288115 and of all the daughter products agree with the data of the experiment in which these nuclei were synthesized for the first time. The new 289115 events demonstrate the same decay properties as those observed for 289115 populated by a decay of 293117 produced in the 249Bk+48Ca reaction to provide cross-bombardment evidence. Results of recent experiments at the Dubna gas-filled recoil separator aimed at studying production crosssections, excitation functions, and nuclear decay properties for isotopes 293,294117 synthesized in the 249Bk+48Ca reaction at five projectile energies are presented. In addition, a single decay of 294118 was observed from the reaction with 249Cf - a result of the in-growth of 249Cf in the 249Bk target.

  18. Effect of coupling in the 28Si+154Sm reaction studied by quasi-elastic scattering

    NASA Astrophysics Data System (ADS)

    Kaur, Gurpreet; Behera, B. R.; Jhingan, A.; Nayak, B. K.; Dubey, R.; Sharma, Priya; Thakur, Meenu; Mahajan, Ruchi; Saneesh, N.; Banerjee, Tathagata; Khushboo, Kumar, A.; Mandal, S.; Saxena, A.; Sugathan, P.; Rowley, N.

    2016-09-01

    The study of the coupling to collective states of the 28Si projectile and 154Sm target in fusion mechanism is reported. Understanding such couplings is important as they influence the barrier height and the formation probability of the compound nuclei, which in turn may be related to the synthesis of superheavy elements in heavier systems. In the present work, before performing the coupled-channel calculations, we wish to obtain an experimental signature of coupling to projectile and target excitation through barrier distribution (BD) study. To this end, the BDs of the 28Si+154Sm and 16O+154Sm systems have been compared using existing fusion data, scaled to compensate for the differences between the nominal Coulomb barriers and the respective coupling strengths. However, the large error bars on the high-energy side of the fusion BD prevent any definite identification of such signatures. We have, therefore, performed a quasi-elastic (QE) scattering experiment for the heavier 28Si+154Sm system and compared its results with existing QE data for the 16O projectile. Since QE BDs are precise at higher energies, the comparison has shown that the BD of 28Si+154Sm is similar to that of 16O+154Sm to a large extent except for a peaklike structure on the higher energy side. The similarity shows that the 154Sm deformation plays a major role in the fusion mechanism of 28Si+154Sm system. The peaklike structure is attributed to 28Si excitation. In contrast with previous studies, it is found that a coupled-channel calculation with vibrational coupling to the first 2+ state of 28Si reproduces this structure rather well. However, an almost identical result is found with the rotational coupling scheme if one considers the large positive hexadecapole deformation of the projectile. A value around that given by Möller and Nix (β4≈0.25 ) leads to a strong cancellation in the re-orientation term that couples the 2+ state back to itself, making that state look vibrational in this

  19. Differential cross sections measurement of 28Si(p,p/γ)28Si and 29Si(p,p/γ)29Si reactions for PIGE applications

    NASA Astrophysics Data System (ADS)

    Jokar, A.; Kakuee, O.; Lamehi-Rachti, M.

    2016-03-01

    Differential cross sections for gamma-ray emission from the 28Si(p,p/γ)28Si (Eγ = 1779 keV) and the 29Si(p,p/γ)29Si (Eγ = 1273 keV) nuclear reactions were measured in the energy range of 2.0-3.2 MeV and 2.0-3.0 MeV, respectively. The thin Si targets were prepared by evaporating natural SiO onto self-supporting Ag films. The gamma-rays and backscattered protons were detected simultaneously. An HPGe detector placed at an angle of 90° with respect to beam direction was employed to collect gamma-rays while an ion implanted Si detector placed at a scattering angle of 165° was used to detect backscattered protons. The great advantage of this work is that differential cross sections were obtained with a procedure irrespective of absolute value of the collected beam charge.

  20. Elastic and inelastic scattering of 50-MeV pions from 28Si and 30Si

    NASA Astrophysics Data System (ADS)

    Wienands, U.; Hessey, N.; Barnett, B. M.; Rozon, F. M.; Roser, H. W.; Altman, A.; Johnson, R. R.; Gill, D. R.; Smith, G. R.; Wiedner, C. A.; Manley, D. M.; Berman, B. L.; Crawford, H. J.; Grion, N.

    1987-02-01

    Angular distributions of the differential cross section for elastic and inelastic scattering of 50-MeV π+ and π- on 28Si and 30Si have been measured to a relative accuracy of 5-10 We fitted the cross section of elastic π+ and π- scattering from 28Si simultaneously with an optical model using a second-order potential of the Michigan State University form. Our best-fit parameters differ from those given previously. The ratio of the neutron and proton transition-matrix elements for the first Jπ=2+ state in 28Si is found from the inelastic cross section to be 1.13+/-0.09. For 30Si, the ratio is found to be 0.93+/-0.09, which differs significantly from the value derived from lifetime measurements on mirror nuclei.

  1. Spin alignment and density matrix measurement in sup 28 Si + sup 12 C orbiting reaction

    SciTech Connect

    Ray, A.; Shapira, D.; Halbert, M.L.; Gomez del Campo, J.; Kim, H.J. ); Sullivan, J.P. . Cyclotron Inst.); Shivakumar, B.; Mitchell, J. . Wright Nuclear Structure Lab.)

    1990-01-01

    Gamma-ray angular correlations have been measured for the strongly damped reactions {sup 12}C({sup 28}Si,{sup 12}C){sup 28}Si between {theta}{sub cm} = (120{degree} {minus} 160{degree}) for E{sub cm} = 43.5 and 48 MeV. We find that the density matrices for the {sup 12}C(2{sub 1}{sup +}) and {sup 28}Si states are almost diagonal with respect to the direction of motion of the outgoing particle. The measured density matrices and spin alignments are consistent with the picture of formation of a long-lived dinuclear complex undergoing orbiting, bending and wriggling motions, but not with those obtained from statistical compound nucleus or sticking model calculations. 17 refs., 2 figs., 1 tab.

  2. Fusion of Si28+Si28,30: Different trends at sub-barrier energies

    NASA Astrophysics Data System (ADS)

    Montagnoli, G.; Stefanini, A. M.; Esbensen, H.; Jiang, C. L.; Corradi, L.; Courtin, S.; Fioretto, E.; Grebosz, J.; Haas, F.; Jia, H. M.; Mazzocco, M.; Michelagnoli, C.; Mijatović, T.; Montanari, D.; Parascandolo, C.; Scarlassara, F.; Strano, E.; Szilner, S.; Torresi, D.

    2014-10-01

    Background: The fusion excitation function of the system Si28+Si28 at energies near and below the Coulomb barrier is known only down to ≃15 mb. This precludes any information on both coupling effects on sub-barrier cross sections and the possible appearance of hindrance. For Si28+Si30 even if the fusion cross section is measured down to ≃50 μb, the evidence of hindrance is marginal. Both systems have positive fusion Q values. While Si28 has a deformed oblate shape, Si30 is spherical. Purpose: We investigate 1. the possible influence of the different structure of the two Si isotopes on the fusion excitation functions in the deep sub-barrier region and 2. whether hindrance exists in the Si+Si systems and whether it is strong enough to generate an S-factor maximum, thus allowing a comparison with lighter heavy-ion systems of astrophysical interest. Methods: Si28 beams from the XTU Tandem accelerator of the INFN Laboratori Nazionali di Legnaro were used. The setup was based on an electrostatic beam separator, and fusion evaporation residues (ER) were detected at very forward angles. Angular distributions of ER were measured. Results: Fusion cross sections of Si28+Si28 have been obtained down to ≃600 nb. The slope of the excitation function has a clear irregularity below the barrier, but no indication of a S-factor maximum is found. For Si28+Si30 the previous data have been confirmed and two smaller cross sections have been measured down to ≃4 μb. The trend of the S-factor reinforces the previous weak evidence of hindrance. Conclusions: The sub-barrier cross sections for Si28+Si28 are overestimated by coupled-channels calculations based on a standard Woods-Saxon potential, except for the lowest energies. Calculations using the M3Y+repulsion potential are adjusted to fit the Si28+Si28 and the existing Si30+Si30 data. An additional weak imaginary potential (probably simulating the effect of the oblate Si28 deformation) is required to fit the low-energy trend of

  3. First direct determination of the 48Ca double-β decay Q value

    NASA Astrophysics Data System (ADS)

    Bustabad, S.; Bollen, G.; Brodeur, M.; Lincoln, D. L.; Novario, S. J.; Redshaw, M.; Ringle, R.; Schwarz, S.; Valverde, A. A.

    2013-08-01

    The low-energy beam and ion trap Penning trap mass spectrometer was used for an improved determination of the 48Ca double-β decay Q value: Qββ=4268.121(79)keV. The new value is 1.2 keV greater than the value in the 2012 atomic mass evaluation [Chin. Phys. CCPCHCQ1674-113710.1088/1674-1137/36/12/003 36, 1603 (2012)], a shift of three σ, and is a factor of 5 more precise. Accurate knowledge of this Q value is important for experimental searches to observe neutrinoless double-β decay (0νββ) in 48Ca and is essential for extracting the effective mass of the electron neutrino if the 48Ca half-life of 0νββ was experimentally determined.

  4. CANDLES project for the study of neutrino-less double beta decay of 48Ca

    NASA Astrophysics Data System (ADS)

    Yoshida, Sei

    2014-09-01

    There is, presently, strong evidence that neutrinos undergo flavor oscillations,and hence must have finite masses. Neutrino-less double beta (0 νββ) decay measurement offers a realistic opportunity to establish the Majorana nature of neutrinos and gives the absolute scale of the effective neutrino mass. CANDLES is the project to search for 0 νββ decay of 48Ca. A distinctive characteristic of 48Ca is the highest Q value (4.3 MeV) among 0 νββ isotopes. Therefore it enables us to measure 0 νββ decay signals in background free contribution. The CANDLES system consists of undoped CaF2 scintillators (CaF2),liquid scintillator (LS), and large photomultiplier tubes (PMTs). A large number of CaF2 crystals in the form of 10 cm cubes are immersed in the LS. Scintillating CaF2 crystals work as an active source detector for 0 νββ decay of 48Ca, together with LS as a multi-purpose detector component to both reject backgrounds and to propagate scintillation photons. PMTs are placed around the LS vessel to detect photons from both scintillators. The simple design concept of CANDLES enables us to increase the 48Ca source amount. 48Ca enrichment is also effective for the high sensitive measurement, because natural abundance of 48Ca is very low (0.19%). We have studied 48Ca enrichment and succeeded in obtaining enriched 48Ca although it is a small amount. Now we have developed the CANDLES III system, which contained with 300kg CaF2 crystals without enrichment, at the Kamioka underground laboratory. New light collection system was installed in 2012, and accordingly photo-coverage has been enlarged by about 80%. Further improvement will be expected in 2014 by installing a detector cooling system in order to increase light emission from CaF2 crystals. The detail of the latest CANDLES III (U.G.) system and its performance will be presented. Recently, we found that gamma rays from neutron captures on materials surrounding detector could be dominant background. These

  5. A basic study on the production of enriched isotope {}^{48}Ca by using crown-ether resin

    NASA Astrophysics Data System (ADS)

    Umehara, S.; Kishimoto, T.; Kakubata, H.; Nomura, M.; Kaneshiki, T.; Suzuki, T.; Fujii, Y.; Nemoto, S.

    2015-05-01

    The use of enriched ^{48}Ca is expected to improve the sensitivity of ^{48}Ca double beta decay measurements. We have studied the enrichment of ^{48}Ca with chemical exchange isotope separation using benzo-18-crown-6-ether resin. Chromatographic migrations of the calcium adsorption band were carried out at different migration lengths, 1 m, 20 m, and 200 m, using glass columns. Separation coefficients were observed as approximately 3 × 10^{-3}. Efforts have been made towards the production of benzo-18-crown-6-ether monomer at reasonable cost for the production of crown-ether resin for the separation of ^{48}Ca.

  6. Positron-electron decay of 28Si at an excitation energy of 50 MeV

    NASA Astrophysics Data System (ADS)

    Buda, A.; Bacelar, J. C.; Balanda, A.; van der Ploeg, H.; Sujkowski, Z.; van der Woude, A.

    1993-03-01

    The electron-position pair decay of 28Si at 50 MeV excitation produced by the isospin T=0 (α + 24Mg) and the mixed isospin T=0,1 (3He + 25Mg) reactions has been studied using a special designed Positron-Electron pair spectrometer PEPSI.

  7. Inelastic pion scattering to 2 1+ states of pre12C and 28Si

    NASA Astrophysics Data System (ADS)

    Amos, K.; Berge, L.

    1983-08-01

    Large basis, microscopic models of nuclear structure have been used to specify the “collective” form factors for inelastic scattering to the 2 1+ states in 12C and 28Si. They have been used in a Distorted Wave Impulse Approximation, with π-nucleon t-matrices fixed by elastic scattering analyses, to fit inelastic pion scattering data.

  8. The lattice parameter of the 28Si spheres in the determination of the Avogadro constant

    NASA Astrophysics Data System (ADS)

    Massa, E.; Mana, G.; Ferroglio, L.; Kessler, E. G.; Schiel, D.; Zakel, S.

    2011-04-01

    The Avogadro constant has been determined by atom counting in two enriched 28Si spheres. Atoms were counted by exploiting their ordered arrangement in the spheres and calculating the ratio between sphere and the unit-cell volumes. This paper describes how the values of the sphere lattice parameters and, consequently, their unit-cell volumes were obtained.

  9. Search for 28Si cluster states through the 12C+16O radiative capture

    NASA Astrophysics Data System (ADS)

    Courtin, S.; Goasduff, A.; Haas, F.; Lebhertz, D.; Jenkins, D. G.; Hutcheon, D. A.; Davis, C.; Ruiz, C.

    2013-03-01

    The 12C+16O resonant radiative capture reaction has been studied at 5 bombarding energies around the Coulomb barrier, between Elab = 15.4 and 21.4 MeV. These experiments have been performed at the TRIUMF laboratory (Vancouver, Canada) using the Dragon 0° spectrometer and the associated BGO array. The most remarkable result is the previously unobserved decay path through 28Si doorway states of energies around 12 MeV leading to the measurement of new capture cross-sections. The feeding of specific, deformed states in 28Si from the resonances is discussed, as well as the selective feeding of 1+ T=1 states around 11 MeV.

  10. Coupled channel effect in elastic scattering and fusion for 6,7Li+28Si

    NASA Astrophysics Data System (ADS)

    Sinha, Mandira; Roy, Subinit; Basu, P.; Majumdar, H.; Santra, S.; Parkar, V. V.; Golda, K. S.; Kailas, S.

    2011-10-01

    The fusion excitation and elastic angular distribution were measured for 6,7Li+28Si from below to above Coulomb barrier (≤ 3Vb) energies. The barrier distribution derived from the fusion data was found to be broad and asymmetric at the sub-barrier region, compared to 1D BPM estimation. Effect of rotational coupling on fusion was found to be not so dominant. Phenomenological optical potential parameters, with surface and volume type imaginary potentials, were obtained from f tting of elastic scattering data and energy dependence of real and imaginary surface strengths were investigated around the barrier. CDCC calculations considering only breakup of projectile were performed for 6,7Li+28Si with the elastic scattering data, using the code FRESCO. The effects of breakup of projectile on elastic cross section do not agree with the energy dependence of real and imaginary strength with volume type imaginary potential around the barrier.

  11. Fine structure of the isoscalar giant quadrupole resonance in 28Si and 27Al

    NASA Astrophysics Data System (ADS)

    Usman, I. T.; Buthelezi, Z.; Carter, J.; Cooper, G. R. J.; Fearick, R. W.; Förtsch, S. V.; Fujita, H.; Fujita, Y.; von Neumann-Cosel, P.; Neveling, R.; Papakonstantinou, P.; Pysmenetska, I.; Richter, A.; Roth, R.; Sideras-Haddad, E.; Smit, F. D.

    2016-08-01

    The isoscalar giant quadrupole resonance in 28Si and 27Al has been investigated with high-energy-resolution proton inelastic scattering at Ep=200 MeV and at scattering angles close to the maximum of Δ L =2 angular distributions with the K600 magnetic spectrometer of iThemba LABS, South Africa. Characteristic scales are extracted from the observed fine structure with a wavelet analysis and compared for 28Si with random-phase approximation and second random phase approximation calculations with an interaction derived from the Argonne V18 potential by a unitary transformation. A recent extension of the method to deformed nuclei provides the best description of the data, suggesting the significance of Landau damping.

  12. The Reaction ^1H(^28Si,A)x at 80 MeV/nucleon

    NASA Astrophysics Data System (ADS)

    Romero, J. L.; Brady, F. P.; Cebra, D. A.; Chance, J.; Kintner, J. C.; Osborne, J. H.; Acevedo-Bolton, G.; Morrissey, D. J.; Fauerbach, M.; Pfaff, R.; Powell, C. F.; Sherrill, B. M.; Tang, H. H. K.

    1996-05-01

    Differential cross sections of charged fragments near 0 degrees were measured for the ^1H(^28Si,A)x reaction at 80 MeV/nucleon, using the A1200 zero degree spectrometer at NSCL.footnote G.A. Souliotis et al., Phys. Rev. C46, 1383 (1992) CH2 and C targets were used. The fragments detected ranged from A=5 through A=28. Results are compared with the intranuclear cascade-statistical model.(H.H.K. Tang et al., Phys. Rev. C42, 1598 (1990)) We also present results for the ^12C(^28Si,A) reaction at 80 MeV/nucleon. The overall objective is to characterize the heavy recoils in proton-induced reactions and to complement previous studies of light ions from reactions like ^28Si(p,x).(H.H.K. Tang, IBM J. Res. Dev. (1996) (in press)) Due to applications such as single event upsets in microelectronic systems and dosimetry problems in particle beam-based radiology, there are new demands for recoil data, especially in the energy regime around 100 MeV/nucleon. This work demonstrates the feasibility of reverse kinematics as an accurate means to obtain recoil spectra. This is also the first experiment of a projected program involving similar measurements using O, N and C beams.

  13. Neutron and weak-charge distributions of the 48Ca nucleus

    DOE PAGES

    Hagen, Gaute; Forssen, Christian; Nazarewicz, Witold; ...

    2015-11-02

    What is the size of the atomic nucleus? This deceivably simple question is difficult to answer. Although the electric charge distributions in atomic nuclei were measured accurately already half a century ago, our knowledge of the distribution of neutrons is still deficient. In addition to constraining the size of atomic nuclei, the neutron distribution also impacts the number of nuclei that can exist and the size of neutron stars. We present an ab initio calculation of the neutron distribution of the neutron-rich nucleus 48Ca. We show that the neutron skin (difference between the radii of the neutron and proton distributions)more » is significantly smaller than previously thought. We also make predictions for the electric dipole polarizability and the weak form factor; both quantities that are at present targeted by precision measurements. Here, based on ab initio results for 48Ca, we provide a constraint on the size of a neutron star.« less

  14. Deep inelastic separated response functions from 40Ca and 48Ca

    NASA Astrophysics Data System (ADS)

    Deady, M.; Williamson, C. F.; Zimmerman, P. D.; Altemus, R.; Whitney, R. R.

    1986-06-01

    Deep inelastic scattering cross sections have been measured for 40Ca and 48Ca at electron energies between 100 and 375 MeV at scattering angles of 90° and 140°. Longitudinal and transverse response functions at three-momentum transfers between 250 and 410 MeV/c have been extracted using a Rosenbluth separation. The response functions are compared to calculations modeling the nucleus as a noninteracting relativistic Fermi gas. The model is found to agree with the observed transverse response function in the region of expected quasi-free nucleon knockout, but the model overestimates the observed longitudinal response. Comparisons of the response functions of the two isotopes are made, and differences between 40Ca and 48Ca are seen.

  15. New Superheavy Element Isotopes: 242Pu(48Ca,5n)285114

    SciTech Connect

    Ellison, Paul A; Gregorich, Kenneth E.; Berryman, Jill S.; Bleuel, Darren L.; Clark, Roderick M.; Dragojevic, Irena; Dvorak, Jan; Fallon, Paul; Fineman-Sotomayor, Carolina; Gates, Jacklyn M.; Gothe, Oliver R.; Lee, I-Yang; Loveland, Walter D.; McLaughlin, Joseph P.; Paschalis, Stefanos; Petri, Marina-Kalliopi; Qian, Jing; Stavsetra, Liv; Wiedeking, Mathis; Nitsche, Heino

    2010-10-22

    The new, neutron-deficient, superheavy element isotope {sup 285}114 was produced in {sup 48}Ca irradiations of {sup 242}Pu targets at a center-of-target beam energy of 256 MeV (E* = 50 MeV). The {alpha} decay of {sup 285}114 was followed by the sequential {alpha} decay of four daughter nuclides, {sup 281}Cn, {sup 277}Ds, {sup 273}Hs, and {sup 269}Sg. {sup 265}Rf was observed to decay by spontaneous fission. The measured {alpha}-decay Q values were compared with those from a macroscopic-microscopic nuclear mass model to give insight into superheavy element shell effects. The {sup 242}Pu({sup 48}Ca,5n){sup 285}114 cross section was 0.6{sub -0.5}{sup +0.9} pb.

  16. Production of high intensity {sup 48}Ca for the 88-Inch Cyclotron and other updates

    SciTech Connect

    Benitez, J. Y.; Hodgkinson, A.; Lyneis, C. M. Strohmeier, M.; Thullier, T.; Todd, D.; Xie, D.; Franzen, K. Y.

    2014-02-15

    Recently the Versatile ECR for NUclear Science (VENUS) ion source was engaged in a 60-day long campaign to deliver high intensity {sup 48}Ca{sup 11+} beam to the 88-Inch Cyclotron. As the first long term use of VENUS for multi-week heavy-element research, new methods were developed to maximize oven to target efficiency. First, the tuning parameters of VENUS for injection into the cyclotron proved to be very different than those used to tune VENUS for maximum beam output of the desired charge state immediately following its bending magnet. Second, helium with no oxygen support gas was used to maximize the efficiency. The performance of VENUS and its low temperature oven used to produce the stable requested 75 eμA of {sup 48}Ca{sup 11+} beam current was impressive. The consumption of {sup 48}Ca in VENUS using the low temperature oven was checked roughly weekly, and was found to be on average 0.27 mg/h with an ionization efficiency into the 11+ charge state of 5.0%. No degradation in performance was noted over time. In addition, with the successful operation of VENUS the 88-Inch cyclotron was able to extract a record 2 pμA of {sup 48}Ca{sup 11+}, with a VENUS output beam current of 219 eμA. The paper describes the characteristics of the VENUS tune used for maximum transport efficiency into the cyclotron as well as ongoing efforts to improve the transport efficiency from VENUS into the cyclotron. In addition, we briefly present details regarding the recent successful repair of the cryostat vacuum system.

  17. Transverse response functions in deep inelastic electron scattering for 40Ca, 48Ca, and 56Fe

    NASA Astrophysics Data System (ADS)

    Meziani, Z. E.; Barreau, P.; Bernheim, M.; Morgenstern, J.; Turck-Chieze, S.; Altemus, R.; McCarthy, J.; Orphanos, L. J.; Whitney, R. R.; Capitani, G. P.; de Sanctis, E.; Frullani, S.; Garibaldi, F.

    1985-03-01

    Deep-inelastic inclusive electron-scattering cross sections from 40Ca, 48Ca, and 56Fe have been measured at 60°, 90°, and 140° and at energy transfers including the Δ(3,3) region. The transverse response function in the momentum interval 300 MeV/c<||q-->||<600 MeV/c was extracted by the Rosenbluth prescription. Different theoretical approaches to the quasielastic region are compared to the data. A mass-number scaling is observed.

  18. Production of high intensity 48Ca for the 88-Inch Cyclotron and other updates

    NASA Astrophysics Data System (ADS)

    Benitez, J. Y.; Franzen, K. Y.; Hodgkinson, A.; Lyneis, C. M.; Strohmeier, M.; Thullier, T.; Todd, D.; Xie, D.

    2014-02-01

    Recently the Versatile ECR for NUclear Science (VENUS) ion source was engaged in a 60-day long campaign to deliver high intensity 48Ca11+ beam to the 88-Inch Cyclotron. As the first long term use of VENUS for multi-week heavy-element research, new methods were developed to maximize oven to target efficiency. First, the tuning parameters of VENUS for injection into the cyclotron proved to be very different than those used to tune VENUS for maximum beam output of the desired charge state immediately following its bending magnet. Second, helium with no oxygen support gas was used to maximize the efficiency. The performance of VENUS and its low temperature oven used to produce the stable requested 75 eμA of 48Ca11+ beam current was impressive. The consumption of 48Ca in VENUS using the low temperature oven was checked roughly weekly, and was found to be on average 0.27 mg/h with an ionization efficiency into the 11+ charge state of 5.0%. No degradation in performance was noted over time. In addition, with the successful operation of VENUS the 88-Inch cyclotron was able to extract a record 2 pμA of 48Ca11+, with a VENUS output beam current of 219 eμA. The paper describes the characteristics of the VENUS tune used for maximum transport efficiency into the cyclotron as well as ongoing efforts to improve the transport efficiency from VENUS into the cyclotron. In addition, we briefly present details regarding the recent successful repair of the cryostat vacuum system.

  19. Fusion of the positive Q-value system {sup 36}S+{sup 48}Ca

    SciTech Connect

    Montagnoli, G.; Beghini, S.; Guiot, B.; Mason, P.; Scarlassara, F.; Stefanini, A. M.; Silvestri, R.; Corradi, L.; Fioretto, E.; Courtin, S.; Haas, F.; Lebhertz, D.; Marginean, N.; Sagaidak, R. N.; Szilner, S.

    2009-03-04

    The fusion excitation function for {sup 36}S+{sup 48}Ca with positive Q-value for the compound nucleus formation, has been measured from near the barrier down to very low energies, where ''fusion hindrance'' may be expected. No evidence of hindrance shows up in the measured energy range. Coupled-channels calculations have been performed with a large diffuseness parameter of the Woods-Saxon potential, reproducing the data above and below the barrier.

  20. 40,48Ca+144,154Sm: Deformation and Shell

    SciTech Connect

    Knyazheva, G. N.; Kozulin, E. M.; Sagaidak, R. N.; Itkis, M. G.; Kondratiev, N. A.; Stefanini, A. M.; Behera, B. R.; Corradi, L.; Fioretto, E.; Gadea, A.; Latina, A.; Szilner, S.; Trotta, M.; Beghini, S.; Montagnoli, G.; Scarlassara, F.; Haas, F.; Rowley, N.; Gomes, P. R. S.; Szanto de Toledo, A.

    2007-05-22

    Mass-energy and angular distributions of fission fragments for the 48Ca+144,154Sm{yields}192,202Pb, 40Ca+154Sm{yields}194Pb reactions have been measured. Fusion suppression and the presence of quasi-fission at energies near and below the Coulomb barrier have been observed for the reactions with the deformed target 154Sm. In the case of the spherical 144Sm target no evidence of quasi-fission has been found.

  1. Development of a high intensity 48Ca ion beam for the heavy element program

    SciTech Connect

    Wutte, Daniela; Leitner, Mattheus; Lyneis, Claude

    2002-02-02

    A high intensity {sup 48}Ca ion beam has been developed at the 88 Inch Cyclotron for the synthesis of {sup 283}112 using the reaction {sup 238}U({sup 48}Ca, 3n). An ion beam intensity of {approx} 700 pnA was delivered on target, resulting in a total dose of 2 x 10{sup 18} ions over a six day period. Since {sup 48}Ca is a very expensive and rare isotope minimal consumption is essential. Therefore a new oven [1] and special tantalum liner [2] have been developed for the AECR-U ion source during the last year to improve the metal ion beam efficiency. Both the LBL ECR and the AECR-U ion sources are built with radial access. Six radial slots between the sextupole magnet bars provide additional pumping and easy access to the plasma chamber for ovens and feedthroughs. Two types of radial ovens have been used at LBNL in the past, operating at temperatures up to 2100 C.

  2. CORRELATION OF {sup 48}Ca, {sup 50}Ti, AND {sup 138}La HETEROGENEITY IN THE ALLENDE REFRACTORY INCLUSIONS

    SciTech Connect

    Chen, Hsin-Wei; Lee, Typhoon; Lee, Der-Chuen; Chen, Jiang-Chang

    2015-06-10

    Precise determinations of {sup 48}Ca anomalies in Allende calcium–aluminum-rich inclusions (CAIs) are reported in this work. There are endemic positive {sup 48}Ca/{sup 44}Ca anomalies in all analyzed CAIs after normalization to {sup 42}Ca/{sup 44}Ca, and it is clearly shown that there is no simple correlation between {sup 48}Ca/{sup 44}Ca and {sup 50}Ti/{sup 48}Ti anomalies, in agreement with Jungck et al. Compared to the {sup 48}Ca/{sup 44}Ca versus {sup 50}Ti/{sup 48}Ti correlation line defined by differentiated meteorites, reported by Chen et al., the CAIs plot to elevated {sup 50}Ti/{sup 48}Ti. Assuming the {sup 48}Ca/{sup 44}Ca anomalies of both CAIs and differentiated meteorites came from the same source, excess {sup 50}Ti anomalies in CAIs can be calculated by subtracting the part associated with {sup 48}Ca/{sup 44}Ca. These excesses show a linear correlation with {sup 138}La anomalies, a neutrino-process nuclide. According to current stellar nucleosynthetic models, we therefore suggest that the solar system {sup 48}Ca, {sup 50}Ti, and {sup 138}La isotopic variations are made of mixtures between grains condensed from ejecta of neutron-rich accretion-induced SNe Ia and the O/Ne–O/C zone of core-collapse SNe II.

  3. Study of neutron-deficient isotopes of Fl in the 239Pu, 240Pu + 48Ca reactions

    NASA Astrophysics Data System (ADS)

    Voinov, A. A.; Utyonkov, V. K.; Brewer, N. T.; Oganessian, Yu Ts; Rykaczewski, K. P.; Abdullin, F. Sh; Dmitriev, S. N.; Grzywacz, R. K.; Itkis, M. G.; Miernik, K.; Polyakov, A. N.; Roberto, J. B.; Sagaidak, R. N.; Shirokovsky, I. V.; Shumeiko, M. V.; Tsyganov, Yu S.; Subbotin, V. G.; Sukhov, A. M.; Sabelnikov, A. V.; Vostokin, G. K.; Hamilton, J. H.; Stoyer, M. A.; Strauss, S. Y.

    2016-07-01

    The results of the experiments aimed at the synthesis of Fl isotopes in the 239Pu + 48Ca and 240Pu + 48Ca reactions are presented. The experiment was performed using the Dubna gas-filled recoil separator at the U400 cyclotron. In the 239Pu+48Ca experiment one decay of spontaneously fissioning 284Fl was detected at 245-MeV beam energy. In the 240Pu+48Ca experiment three decay chains of 285Fl were detected at 245 MeV and four decays were assigned to 284Fl at the higher 48Ca beam energy of 250 MeV. The α-decay energy of 285Fl was measured for the first time and decay properties of its descendants 281Cn, 277Ds, 273Hs, 269Sg, and 265Rf were determined more precisely. The cross section of the 239Pu(48Ca,3n)284Fl reaction was observed to be about 20 times lower than those predicted by theoretical models and 50 times less than the value measured in the 244Pu+48Ca reaction. The cross sections of the 240Pu(48Ca,4-3n)284,285Fl at both 48Ca energies are similar and exceed that observed in the reaction with lighter isotope 239Pu by a factor of 10. The decay properties of the synthesized nuclei and their production cross sections indicate rapid decrease of stability of superheavy nuclei with departing from the neutron number N=184 predicted to be the next magic number.

  4. Giant resonances in {sup 24}Mg and {sup 28}Si from 240 MeV {sup 6}Li scattering

    SciTech Connect

    Chen, X.; Lui, Y.-W.; Clark, H. L.; Tokimoto, Y.; Youngblood, D. H.

    2009-07-15

    Elastic and inelastic scattering of 240 MeV {sup 6}Li particles from {sup 24}Mg and {sup 28}Si were measured with the MDM spectrometer. Optical potential parameters for {sup 6}Li+{sup 24}Mg and {sup 6}Li+{sup 28}Si scattering systems were obtained by fitting elastic scattering with two different folding model potentials as well as W-S potentials. E0-E3 giant resonance strength distributions for {sup 28}Si and {sup 24}Mg were obtained. E0 strength corresponding to 106{sub -24}{sup +34}% of the EWSR was identified in {sup 24}Mg and 80{sub -20}{sup +35}% was found for {sup 28}Si between E{sub x}=8.0 to 40.0 MeV.

  5. ESR measurements of phosphorus dimers in isotopically enriched 28Si silicon

    NASA Astrophysics Data System (ADS)

    Shankar, S.; Tyryshkin, A. M.; Lyon, S. A.

    2015-06-01

    Dopants in silicon have been studied for many decades using optical and electron spin resonance (ESR) spectroscopy. Recently, new features have been observed in the spectra of dopants in isotopically enriched 28Si since the reduced inhomogeneous linewidth in this material improves spectral resolution. With this in mind, we measured ESR on exchange coupled phosphorus dimers in 28Si and report two results. First, a fine structure is observed in the ESR spectrum arising from state mixing by the hyperfine coupling to the 31P nuclei, which is enhanced when the exchange energy is comparable to the Zeeman energy. This fine structure enables us to spectroscopically address two separate dimer subensembles, the first with exchange (J ) coupling ranging from 2 to 7 GHz and the second with J ranging from 6 to 60 GHz. Next, the average spin relaxation times T1 and T2 of both dimer subensembles were measured using pulsed ESR at 0.35 T. Both T1 and T2 for transitions between triplet states of the dimers were found to be identical to the relaxation times of isolated phosphorus donors in 28Si, with T2=4 ms at 1.7 K limited by spectral diffusion due to dipolar interactions with neighboring donor electron spins. This result, consistent with theoretical predictions, implies that an exchange coupling of 2-60 GHz does not limit the dimer T1 and T2 in bulk Si at the 10-ms time scale.

  6. New decay branches of the radiative capture reaction {sup 12}C({sup 16}O,{gamma}){sup 28}Si

    SciTech Connect

    Lebhertz, D.; Courtin, S.; Haas, F.; Salsac, M.-D.; Beck, C.; Michalon, A.; Rousseau, M.; Marley, P. L.; Glover, R. G.; Kent, P. E.; Hutcheon, D. A.; Davis, C.; Pearson, J. E.

    2009-01-28

    Resonances in the {sup 12}C({sup 16}O,{gamma}){sup 28}Si radiative capture process at energies around the Coulomb barrier have been probed using the very selective 0 deg. Dragon spectrometer at Triumf and its associated BGO {gamma}-array. For the first time the full level scheme involved in this process has been measured and shows previously unobserved {gamma}-decay to doorway states around 11 MeV in {sup 28}Si.

  7. Neutron distribution, electric dipole polarizability and weak form factor of 48Ca from chiral effective field theory

    NASA Astrophysics Data System (ADS)

    Wendt, Kyle

    2016-03-01

    How large is the 48Ca nucleus? While the electric charge distribution of this nucleus was accurately measured decades ago, both experimental and ab initio descriptions of the neutron distribution are deficient. We address this question using ab initio calculations of the electric charge, neutron, and weak distributions of 48Ca based on chiral effective field theory. Historically, chiral effective field theory calculations of systems larger than 4 nucleons have been plagued by strong systematic errors which result in theoretical descriptions that are too dense and over bound. We address these errors using a novel approach that permits us to accurately reproduce binding energy and charge radius of 48Ca, and to constrain electroweak observables such as the neutron radius, electric dipole polarizability, and the weak form factor. For a full list of contributors to this work, please see ``Neutron and weak-charge distributions of the 48Ca nucleus,'' Nature Physics (2015) doi:10.1038/nphys3529.

  8. A More Accurate Measurement of the {sup 28}Si Lattice Parameter

    SciTech Connect

    Massa, E. Sasso, C. P.; Mana, G.; Palmisano, C.

    2015-09-15

    In 2011, a discrepancy between the values of the Planck constant measured by counting Si atoms and by comparing mechanical and electrical powers prompted a review, among others, of the measurement of the spacing of {sup 28}Si (220) lattice planes, either to confirm the measured value and its uncertainty or to identify errors. This exercise confirmed the result of the previous measurement and yields the additional value d{sub 220} = 192 014 711.98(34) am having a reduced uncertainty.

  9. Microwave Spectrum of a Silicon Monoxide Isotopomer: 28Si18O

    NASA Astrophysics Data System (ADS)

    Cho, Se-Hyung; Saito, Shuji

    1998-03-01

    The rotational transitions of 28Si18O in the ground vibrational state were observed by laboratory microwave spectroscopy for astronomical use. The SiO molecules were generated in a free-space absorption cell by dc-glow discharge in a mixture of tetra-methyl silane, Si(CH3)4, and 18O2. Ten rotational transitions were precisely measured in the 40-444 GHz region. The rotational and centrifugal distortion constants were determined by a least-squares analysis of measured line frequencies: B0=20176.4394(43) and D0=0.025809(32) MHz, with the 3 σ deviations in parentheses.

  10. Relative biological effectiveness of 12C and 28Si radiation in C57BL/6J mice.

    PubMed

    Suman, Shubhankar; Datta, Kamal; Trani, Daniela; Laiakis, Evagelia C; Strawn, Steven J; Fornace, Albert J

    2012-08-01

    Study of heavy ion radiation-induced effects on mice could provide insight into the human health risks of space radiation exposure. The purpose of the present study is to assess the relative biological effectiveness (RBE) of (12)C and (28)Si ion radiation, which has not been reported previously in the literature. Female C57BL/6J mice (n = 15) were irradiated using 4-8 Gy of (28)Si (300 MeV/nucleon energy; LET 70 keV/μm) and 5-8 Gy of (12)C (290 MeV/nucleon energy; LET 13 keV/μm) ions. Post-exposure, mice were monitored regularly, and their survival observed for 30 days. The LD(50/30) dose (the dose at which 50 % lethality occurred by 30-day post-exposure) was calculated from the survival curve and was used to determine the RBE of (28)Si and (12)C in relation to γ radiation. The LD(50/30) for (28)Si and (12)C ion is 5.17 and 7.34 Gy, respectively, and the RBE in relation to γ radiation (LD(50/30)-7.25 Gy) is 1.4 for (28)Si and 0.99 for (12)C. Determination of RBE of (28)Si and (12)C for survival in mice is not only important for space radiation risk estimate studies, but it also has implications for HZE radiation in cancer therapy.

  11. A full 0 h̵ω description of the 2 νββ decay of 48Ca

    NASA Astrophysics Data System (ADS)

    Caurier, E.; Poves, A.; Zuker, A. P.

    1990-12-01

    The lifetime of the 2ν double beta decay of 48Ca is computed, using the wave functions obtained in full fp-shell calculations of 48Ca, 48Sc and 48Ti. The resulting double beta transition amplitude MGT2v = 0.040(MeV) -1 leads to a value T {1}/{2} = 5.5 × 10 19yr, compatible with the experimental bound of T {1}/{2} > 3.6 × 10 19yr.

  12. Experiments on the synthesis of superheavy nuclei 284Fl and 285Fl in the Pu,240239+48Ca reactions

    NASA Astrophysics Data System (ADS)

    Utyonkov, V. K.; Brewer, N. T.; Oganessian, Yu. Ts.; Rykaczewski, K. P.; Abdullin, F. Sh.; Dmitriev, S. N.; Grzywacz, R. K.; Itkis, M. G.; Miernik, K.; Polyakov, A. N.; Roberto, J. B.; Sagaidak, R. N.; Shirokovsky, I. V.; Shumeiko, M. V.; Tsyganov, Yu. S.; Voinov, A. A.; Subbotin, V. G.; Sukhov, A. M.; Sabel'nikov, A. V.; Vostokin, G. K.; Hamilton, J. H.; Stoyer, M. A.; Strauss, S. Y.

    2015-09-01

    Irradiations of 239Pu and 240Pu targets with 48Ca beams aimed at the synthesis of Z =114 flerovium isotopes were performed at the Dubna Gas Filled Recoil Separator. A new spontaneously fissioning (SF) isotope 284Fl was produced for the first time in the 240Pu+48Ca (250 MeV) and 239Pu+48Ca (245 MeV) reactions. The cross section of the 239Pu(48Ca,3 n )284Fl reaction channel was about 20 times lower than predicted by theoretical models and about 50 times lower than the maximum fusion-evaporation cross section for the 3 n and 4 n channels measured in the 244Pu+48Ca reaction. In the 240Pu+48Ca experiment, performed at 245 MeV in order to maximize the 3 n -evaporation channel, three decay chains of 285Fl were detected. The α -decay energy of 285Fl was measured for the first time and decay properties of its descendants 281Cn, 277Ds, 273Hs, 269Sg, and 265Rf were determined with higher accuracy. The assignment of SF events observed during the irradiation of the 240Pu target with a 250 MeV 48Ca beam to 284Fl decay is presented and discussed. The cross sections at both 48Ca energies are similar and exceed that observed in the reaction with the lighter isotope 239Pu by a factor of 10. The decay properties of the synthesized nuclei and their production cross sections indicate a rapid decrease of stability of superheavy nuclei as the neutron number decreases from the predicted magic neutron number N =184 .

  13. Neutron skins of 208Pb and 48Ca from pionic probes

    NASA Astrophysics Data System (ADS)

    Friedman, E.

    2012-12-01

    The neutron skin of 208Pb has received considerable attention in recent years. A variety of strongly-interacting probes depict a rather consistent picture but pionic probes have not been referred to in this context. We present here neutron-skin values from pionic atoms and from total reaction cross sections of π+ between 0.7 and 2 GeV/c which fit well into the picture. In addition we show that a neutron-skin for 48Ca can be obtained from existing data on pionic atoms and the result agrees with pion scattering experiments and with the scattering of α particles.

  14. Quasifission processes in {sup 40,48}Ca+{sup 144,154}Sm reactions

    SciTech Connect

    Knyazheva, G. N.; Kozulin, E. M.; Sagaidak, R. N.; Chizhov, A. Yu.; Itkis, M. G.; Kondratiev, N. A.; Voskressensky, V. M.; Stefanini, A. M.; Behera, B. R.; Corradi, L.; Fioretto, E.; Gadea, A.; Latina, A.; Szilner, S.; Trotta, M.; Beghini, S.; Montagnoli, G.; Scarlassara, F.; Haas, F.; Rowley, N.

    2007-06-15

    Mass-energy and angular distributions of fission fragments for the {sup 48}Ca+{sup 144,154}Sm{yields}{sup 192,202}Pb, {sup 40}Ca+{sup 154}Sm{yields}{sup 194}Pb reactions have been measured. Fusion suppression and the presence of quasifission at energies near and below the Coulomb barrier have been observed for the reactions with the deformed target {sup 154}Sm. In the case of the spherical {sup 144}Sm target no evidence of quasifission has been found. Quasifission cross sections have been extracted from total fission-like events by analysis of their mass and angular distributions.

  15. Toward the Redefinition of the Kilogram from the 28Si International Research Project

    NASA Astrophysics Data System (ADS)

    Fujii, Kenichi

    In the international system of units, the kilogram in the only SI base unit still defined by a material artefact. In order to redefine this unit with a fundamental physical constant, an international research project was launched in 2004 for determining the Avogadro constant, NA, by counting the atoms in an isotopically enriched 28Si crystal. The counting procedure relies on the measurements of the molar and atomic volumes of 1 kg spheres made of the 28Si crystal. In 2011, the project succeeded in measuring the Avogadro constant with a smallest standard uncertainty, 3.0 × 10-8 NA. Because of an unexpected metallic contamination at the surface of the spheres, the measurement uncertainty was larger than the target of the project by a factor of 1.5. In order to further reduce the uncertainty, a new international research project was launched in 2012. Outline of the new project and the improvements of the measurements will be introduced at the forum. Note from Publisher: This article contains the abstract only.

  16. Molar mass of silicon highly enriched in 28Si determined by IDMS

    NASA Astrophysics Data System (ADS)

    Pramann, Axel; Rienitz, Olaf; Schiel, Detlef; Schlote, Jan; Güttler, Bernd; Valkiers, Staf

    2011-04-01

    The molar mass of a new silicon crystal material highly enriched in 28Si ('Si28', x(28Si) >99.99%) has been measured for the first time using a combination of a modified isotope dilution mass spectrometry (IDMS) technique and a high resolution multicollector-ICP-mass spectrometer. This work is related to the redetermination of the Avogadro constant NA with an intended relative measurement uncertainty urel(NA) <= 2 × 10-8. The corresponding experimental investigations of the International Avogadro Coordination (IAC) were performed using this novel 'Si28' material. One prerequisite of the redetermination of NA is the determination of the isotopic composition and thus molar mass of 'Si28' with urel(M('Si28')) <= 1 × 10-8. At PTB, a molar mass M('Si28') = 27.976 970 27(23) g mol-1 has been determined with an associated relative uncertainty urel(M('Si28')) = 8.2 × 10-9, opening the opportunity to reach the target uncertainty of NA.

  17. Status and future prospect of 48Ca double beta decay search in CANDLES

    NASA Astrophysics Data System (ADS)

    Iida, T.; Nakajima, K.; Ajimura, S.; Batpurev, T.; Chan, W. M.; Fushimi, K.; Hazama, R.; Kakubata, H.; Khai, B. T.; Kishimoto, T.; Li, X.; Maeda, T.; Masuda, A.; Matsuoka, K.; Morishita, K.; Nakatani, N.; Nomachi, M.; Noshiro, S.; Ogawa, I.; Ohata, T.; Osumi, H.; Suzuki, K.; Tamagawa, Y.; Tesuno, K.; Trang, V. T. T.; Uehara, T.; Umehara, S.; Yoshida, S.

    2016-05-01

    The observation of neutrino-less double beta decay (0vßß) would be the most practical way to prove the Majorana nature of the neutrino and lepton number violation. CANDLES studies 48Ca double beta decay using CaF2 scintillator. The main advantage of 48Ca is that it has the highest Q-value (4.27 MeV) among all the isotope candidates for 0vßß. The CANDLES III detector is currently operating with 300kg CaF2 crystals in the Kamioka underground observatory, Japan. In 2014, a detector cooling system and a magnetic cancellation coil was installed with the aim to increase light emission of CaF2 scintillator and photo-electron collection efficiency of the photo-multipliers. After this upgrade, light yield was increased to 1000 p.e./MeV which is 1.6 times larger than before. According to data analysis and simulation, main background source in CANDLES is turned out to be high energy external gamma-ray originating neutron capture on the surrounding materials, so called (n,γ). Upgrading the detector by installing neutron and gamma-ray shield can reduce the remaining main backgrounds by two order magnitude. In this report, we discuss the detail of (n,γ) and background reduction by additional shielding.

  18. Di-lepton yield from the decay of excited 28Si states

    NASA Astrophysics Data System (ADS)

    Bacelar, J. C.; Buda, A.; Bałanda, A.; Krasznahorkay, A.; van der Ploeg, H.; Sujkowski, Z.; van der Woude, A.

    1994-03-01

    The first dilepton yield measurements from excited nuclear states obtained with a new Positron-Electron Pair Spectroscopic Instrument (PEPSI) are reported. Nuclear states in 28Si, with an initial excitation energy E∗ = 50 MeV, were populated via the isospin T = 0 reaction 4He + 24Mg and the mixed-isospin 3He + 25Mg reaction. In both reactions the dilepton (e +e -) and photon decay yields were measured concurrently. An excess of counts in the e +e - spectrum, over the converted photon yield, is observed in the energy region above 15 MeV. An analyses is discussed whereby the observed excess counts are assumed to represent the isoscalar E0 strength in excited nuclear states.

  19. Purity of (28)Si-Enriched Silicon Material Used for the Determination of the Avogadro Constant.

    PubMed

    D'Agostino, Giancarlo; Di Luzio, Marco; Mana, Giovanni; Oddone, Massimo; Bennett, John W; Stopic, Attila

    2016-07-05

    At present, counting atoms in a one-kilogram sphere made of (28)Si-enriched silicon allows the determination of the Avogadro constant with the 2.0 × 10(-8) relative standard uncertainty required for the realization of the definition of the new kilogram. With the exception of carbon, oxygen, boron, nitrogen, and hydrogen, the claimed uncertainty is based on the postulation that the silicon material used to manufacture the sphere was above a particular level of purity. Two samples of the silicon were measured using instrumental neutron activation analysis to collect experimental data to test the purity assumption. The results obtained in two experiments carried out using different research reactor neutron sources are reported. The analysis confirmed that the silicon material was of sufficient purity by quantifying the ultratrace concentration of 12 elements and determining the detection limits of another 54 elements.

  20. Volume determination of the Avogadro spheres of highly enriched 28Si with a spherical Fizeau interferometer

    NASA Astrophysics Data System (ADS)

    Bartl, Guido; Bettin, Horst; Krystek, Michael; Mai, Torsten; Nicolaus, Arnold; Peter, Andreas

    2011-04-01

    Within the scope of the efforts concerning the redefinition of the SI base unit 'kilogram' the final results of the international research project aiming at the redetermination of the Avogadro constant are ready to be announced. Among other quantities the volume of two spheres which are made of a highly enriched 28Si single crystal had to be determined. For this purpose a special Fizeau interferometer for the measurement of the spheres' diameters has been developed at PTB. This paper reports the final results of the volumes, the uncertainties and also the latest findings regarding systematic corrections including the effects of surface layers on the pure silicon core. The results are confirmed by density comparison measurements.

  1. Improved measurement results for the Avogadro constant using a 28Si-enriched crystal

    NASA Astrophysics Data System (ADS)

    Azuma, Y.; Barat, P.; Bartl, G.; Bettin, H.; Borys, M.; Busch, I.; Cibik, L.; D'Agostino, G.; Fujii, K.; Fujimoto, H.; Hioki, A.; Krumrey, M.; Kuetgens, U.; Kuramoto, N.; Mana, G.; Massa, E.; Meeß, R.; Mizushima, S.; Narukawa, T.; Nicolaus, A.; Pramann, A.; Rabb, S. A.; Rienitz, O.; Sasso, C.; Stock, M.; Vocke, R. D., Jr.; Waseda, A.; Wundrack, S.; Zakel, S.

    2015-04-01

    New results are reported from an ongoing international research effort to accurately determine the Avogadro constant by counting the atoms in an isotopically enriched silicon crystal. The surfaces of two 28Si-enriched spheres were decontaminated and reworked in order to produce an outer surface without metal contamination and improved sphericity. New measurements were then made on these two reconditioned spheres using improved methods and apparatuses. When combined with other recently refined parameter measurements, the Avogadro constant derived from these new results has a value of NA = 6.022 140 76(12) × 1023 mol-1. The x-ray crystal density method has thus achieved the target relative standard uncertainty of 2.0  ×  10-8 necessary for the realization of the definition of the new kilogram.

  2. Determination of the Avogadro constant by counting the atoms in a 28Si crystal.

    PubMed

    Andreas, B; Azuma, Y; Bartl, G; Becker, P; Bettin, H; Borys, M; Busch, I; Gray, M; Fuchs, P; Fujii, K; Fujimoto, H; Kessler, E; Krumrey, M; Kuetgens, U; Kuramoto, N; Mana, G; Manson, P; Massa, E; Mizushima, S; Nicolaus, A; Picard, A; Pramann, A; Rienitz, O; Schiel, D; Valkiers, S; Waseda, A

    2011-01-21

    The Avogadro constant links the atomic and the macroscopic properties of matter. Since the molar Planck constant is well known via the measurement of the Rydberg constant, it is also closely related to the Planck constant. In addition, its accurate determination is of paramount importance for a definition of the kilogram in terms of a fundamental constant. We describe a new approach for its determination by counting the atoms in 1 kg single-crystal spheres, which are highly enriched with the 28Si isotope. It enabled isotope dilution mass spectroscopy to determine the molar mass of the silicon crystal with unprecedented accuracy. The value obtained, NA = 6.022,140,78(18) × 10(23) mol(-1), is the most accurate input datum for a new definition of the kilogram.

  3. High precision calcium isotope analysis using 42Ca-48Ca double-spike TIMS technique

    NASA Astrophysics Data System (ADS)

    Feng, L.; Zhou, L.; Gao, S.; Tong, S. Y.; Zhou, M. L.

    2014-12-01

    Double spike techniques are widely used for determining calcium isotopic compositions of natural samples. The most important factor controlling precision of the double spike technique is the choice of appropriate spike isotope pair, the composition of double spikes and the ratio of spike to sample(CSp/CN). We propose an optimal 42Ca-48Ca double spike protocol which yields the best internal precision for calcium isotopic composition determinations among all kinds of spike pairs and various spike compositions and ratios of spike to sample, as predicted by linear error propagation method. It is suggested to use spike composition of 42Ca/(42Ca+48Ca) = 0.44 mol/mol and CSp/(CN+ CSp)= 0.12mol/mol because it takes both advantages of the largest mass dispersion between 42Ca and 48Ca (14%) and lowest spike cost. Spiked samples were purified by pass through homemade micro-column filled with Ca special resin. K, Ti and other interference elements were completely separated, while 100% calcium was recovered with negligible blank. Data collection includes integration time, idle time, focus and peakcenter frequency, which were all carefully designed for the highest internal precision and lowest analysis time. All beams were automatically measured in a sequence by Triton TIMS so as to eliminate difference of analytical conditions between samples and standards, and also to increase the analytical throughputs. The typical internal precision of 100 duty cycles for one beam is 0.012‒0.015 ‰ (2δSEM), which agrees well with the predicted internal precision of 0.0124 ‰ (2δSEM). Our methods improve internal precisions by a factor of 2‒10 compared to previous methods of determination of calcium isotopic compositions by double spike TIMS. We analyzed NIST SRM 915a, NIST SRM 915b and Pacific Seawater as well as interspersed geological samples during two months. The obtained average δ44/40Ca (all relative to NIST SRM 915a) is 0.02 ± 0.02 ‰ (n=28), 0.72±0.04 ‰ (n=10) and 1

  4. Results from the First {sup 249}Cf + {sup 48}Ca Experiment

    DOE R&D Accomplishments Database

    Oganessian, Y. T.; Utyonkov, V. K.; Lobanov, Y. V.; Abdullin, F. S.; Polyakov, A. N.; Shirokovsky, I. V.; Tsyganov, Y. S.; Mezentsev, A. N.; Iliev, S.; Subbotin, V. G.; Sukhov, A. M.; Ivanov, O. V.; Voinov, A. A.; Subotic, K.; Zagrebaev, V. I.; Itkis, M. G.; Moody, K. J.; Wild, J. F.; Stoyer, M. A.; Stoyer, N. J.; Laue, C. A.; Shaughnessy, D. A.; Patin, J. B.; Lougheed, R. W.

    2003-02-03

    The present paper reports the results of an attempt aimed at the synthesis of element 118 in the reaction {sup 249}Cf({sup 48}Ca,3n){sup 294}118. The experiment was performed employing the Dubna Gas-filled Recoil Separator and the U400 heavy-ion cyclotron at FLNR, JINR, Dubna. In the course of a 2300-hour irradiation of an enriched {sup 249}Cf target (0.23 mg/cm{sup 2}) with a beam of 245-MeV {sup 48}Ca ions, we accumulated a total beam dose of 2.5 x 10{sup 19} ions. We detected two events that may be attributed to the formation and decay of nuclei with Z=118. For one event, we observed a decay chain of two correlated {alpha}-decays with corresponding energies and correlation times of E{sub {alpha}1} = 11.65 {+-} 0.06 MeV, t{sub {alpha}1} = 2.55 ms and E{sub {alpha}2} = 10.71 {+-} 0.17 MeV, t{sub {alpha}2} = 42.1 ms and, finally, a spontaneous fission with the sum of the kinetic energies of the fission fragments E{sub tot} = 207 MeV (TKE {approx} 230 MeV) and t{sub SF} = 0.52 s. In the second event chain, the recoil nucleus decayed into two fission fragments with E{sub tot} = 223 MeV (TKE {approx} 245 MeV) 3.16 ms later, without intervening {alpha} decays. The probabilities that these events were caused by the chance correlations of unrelated signals are negligible. Both events were observed at an excitation energy of the compound nucleus {sup 297}118 of E* = 30.0 {+-} 2.4 MeV, close to the expected maximum of the 3n-evaporation channel. The relationship between the decay energy Q{sub {alpha}} and decay period T{sub {alpha}} shows that sequential {alpha}-transitions in the first event correspond to the decay chain with Z = 118{_}116{_}114. Decay characteristics of the newly observed nuclides are compared with radioactive decay properties of the even-even isotopes with Z = 116, 114 and 112 previously produced in the reactions {sup 244}Pu, {sup 248}Cm + {sup 48}Ca and calculations made in various nuclear models.

  5. Molar-mass measurement of a 28Si-enriched silicon crystal for determination of the Avogadro constant

    NASA Astrophysics Data System (ADS)

    Narukawa, Tomohiro; Hioki, Akiharu; Kuramoto, Naoki; Fujii, Kenichi

    2014-06-01

    The molar mass of a 28Si-enriched crystal was measured at the National Metrology Institute of Japan to determine the Avogadro constant by the x-ray crystal density method as part of the International Avogadro Coordination project. The molar mass was determined by isotope ratio measurements using a multicollector inductively coupled plasma mass spectrometer combined with an isotope dilution technique. The 28Si-enriched crystal was dissolved in tetramethylammonium hydroxide and three different blended solutions were used to correct for mass bias in the measurement. The molar mass of the 28Si-enriched crystal was determined to be 27.976 970 09 g mol-1 with a standard uncertainty of 0.000 000 14 g mol-1. This corresponds to a relative standard uncertainty of 5.2 × 10-9. This result is consistent with measurements reported by the Physikalisch-Technische Bundesanstalt, Germany.

  6. Study of the Reaction 48Ca + 248Cm → 296Lv* at RIKEN-GARIS

    NASA Astrophysics Data System (ADS)

    Kaji, Daiya; Morita, Kosuke; Morimoto, Kouji; Haba, Hiromitsu; Asai, Masato; Fujita, Kunihiro; Gan, Zaiguo; Geissel, Hans; Hasebe, Hiroo; Hofmann, Sigurd; Huang, MingHui; Komori, Yukiko; Ma, Long; Maurer, Joachim; Murakami, Masashi; Takeyama, Mirei; Tokanai, Fuyuki; Tanaka, Taiki; Wakabayashi, Yasuo; Yamaguchi, Takayuki; Yamaki, Sayaka; Yoshida, Atsushi

    2017-03-01

    The fusion reaction 48Ca + 248Cm → 296Lv* was investigated using the gas-filled recoil ion separator GARIS at RIKEN. The reaction was studied at excitation energies of 41.3 and 38.2 MeV. A total of seven decay chains were observed. Three of the chains were assigned to the decay of 292Lv and three to the decay of 293Lv. A possible observation of an α-decay branch of 284Cn populating the new spontaneously fissioning nucleus 280Ds is discussed. The assignment of one of the decay chains to the 3n evaporation channel, resulting in a spontaneous fission branch of 285Cn, or to the 2n channel, resulting in the population of the new fissioning nucleus 286Cn, is ambiguous. Measured cross sections are in agreement with previously published values.

  7. α clustering in 28Si probed through the identification of high-lying 0+ states

    NASA Astrophysics Data System (ADS)

    Adsley, P.; Jenkins, D. G.; Cseh, J.; Dimitriova, S. S.; Brümmer, J. W.; Li, K. C. W.; Marín-Lámbarri, D. J.; Lukyanov, K.; Kheswa, N. Y.; Neveling, R.; Papka, P.; Pellegri, L.; Pesudo, V.; Pool, L. C.; Riczu, G.; Smit, F. D.; van Zyl, J. J.; Zemlyanaya, E.

    2017-02-01

    Background: Aspects of the nuclear structure of light α -conjugate nuclei have long been associated with nuclear clustering based on α particles and heavier α -conjugate systems such as 12C and 16O. Such structures are associated with strong deformation corresponding to superdeformed or even hyperdeformed bands. Superdeformed bands have been identified in 40Ca and neighboring nuclei and find good description within shell model, mean-field, and α -cluster models. The utility of the α -cluster description may be probed further by extending such studies to more challenging cases comprising lighter α -conjugate nuclei such as 24Mg, 28Si, and 32S. Purpose: The purpose of this study is to look for the number and energy of isoscalar 0+ states in 28Si. These states are the potential bandheads for superdeformed bands in 28Si corresponding to the exotic structures of 28Si. Of particular interest is locating the 0+ bandhead of the previously identified superdeformed band in 28Si. Methods: α -particle inelastic scattering from a natSi target at very forward angles including 0∘ has been performed at the iThemba Laboratory for Accelerator-Based Sciences in South Africa. Scattered particles corresponding to the excitation energy region of 6 to 14 MeV were momentum-analysed in the K600 magnetic spectrometer and detected at the focal plane using two multiwire drift chambers and two plastic scintillators. Results: Several 0+ states have been identified above 9 MeV in 28Si. A newly identified 9.71 MeV 0+ state is a strong candidate for the bandhead of the

  8. Nuclear spin coherence of neutral 31P donors in isotopically enriched 28Si

    NASA Astrophysics Data System (ADS)

    Petersen, E. S.; Tyryshkin, A. M.; Lyon, S. A.; Tojo, S.; Itoh, K. M.; Thewalt, M. L. W.; Riemann, H.; Abrosimov, N. V.; Becker, P.; Pohl, H.-J.

    2014-03-01

    In natural silicon the nuclear spin coherence of neutral 31P donors is limited to about 1 second by flip-flopping 29Si nuclear spins. Here we eliminate this process by using isotopically enriched 28Si with 50 ppm of 29Si. This allows us to examine other processes which may decohere the 31P nuclear spins. We use X-band pulsed ENDOR at 1.7 K to examine isotopically enriched Si crystals with donor concentrations from 1014 to 4x1015 P/cm3 and find a dependence of 31P nuclear spin coherence time on donor concentration. The measured nuclear spin echo decays are fit by a stretched exponential function, exp(-(t/T2)n) , with n ranging from 0.7 to 1. This differs from n of about 2 commonly seen for spectral diffusion due to indirect spin flip-flops. The measured T2 times decrease significantly when the donor concentration increases, changing from 8 s at 1014 to 0.2 s at 4x1015 P/cm3. From the observed donor concentration dependence at higher densities, we conclude that direct electron spin flip-flops are responsible for 31P donor nuclear spin decoherence. This work was supported in part by NSF through the Materials World Network program (DMR-1107606) and the Princeton MRSEC (DMR-0819860), and in part by the U.S. Army Research Office (W911NF-13-1-0179).

  9. Mass distribution and mass resolved angular distribution of fission products in 28Si+232Th

    NASA Astrophysics Data System (ADS)

    Sodaye, Suparna; Tripathi, R.; John, B. V.; Ramachandran, K.; Pujari, P. K.

    2017-01-01

    Background: Fission process with heavier projectiles and actinide targets has contributions from processes, such as compound nucleus fission, transfer-induced fission, and noncompound nucleus fission. Mass distribution and mass-dependent anisotropy can be used to identify and delineate the contributions due to these different processes. Purpose: Mass distribution in 28Si+232Th has been studied at beam energies of 180 and 158 MeV to investigate the nature of mass distribution arising from complete and incomplete momentum-transfer fission events. Mass-dependent angular anisotropy has been measured at 166 MeV to investigate the dominant noncompound nucleus process contributing to the fission. Method: Mass distribution and mass resolved angular distribution of fission products were measured by the recoil catcher method followed by off-line γ -ray spectrometry. Results: Mass distributions for full momentum-transfer fission processes were found to be symmetric, and those for transfer-induced fission were found to be asymmetric at both beam energies. The relative contribution from transfer-induced fission was found to be higher at lower beam energy. The anisotropy of the fission product angular distribution was found to increase with decreasing mass asymmetry. Conclusions: The mass distribution indicates that, apart from the full momentum-transfer fission process, there is a significant contribution due to transfer-induced fission. The mass dependence of angular anisotropy indicated that preequilibrium fission is the dominant noncompound nucleus process in the present reaction system at near barrier energy (Ec .m ./VC=1.06 ) .

  10. Implanted bismuth donors in 28-Si: Process development and electron spin resonance measurements

    NASA Astrophysics Data System (ADS)

    Weis, C. D.; Lo, C. C.; Lang, V.; George, R. E.; Tyryshkin, A. M.; Bokor, J.; Lyon, S. A.; Morton, J. J. L.; Schenkel, T.

    2012-02-01

    Spins of donor atoms in silicon are excellent qubit candidates. Isotope engineered substrates provide a nuclear spin free host environment, resulting in long spin coherence times [1,2]. The capability of swapping quantum information between electron and nuclear spins can enable quantum communication and gate operation via the electron spin and quantum memory via the nuclear spin [2]. Spin properties of donor qubit candidates in silicon have been studied mostly for phosphorous and antimony [1-3]. Bismuth donors in silicon exhibit a zero field splitting of 7.4 GHz and have attracted attention as potential nuclear spin memory and spin qubit candidates [4,5] that could be coupled to superconducting resonators [4,6]. We report on progress in the formation of bismuth doped 28-Si epi layers by ion implantation, electrical dopant activation and their study via pulsed electron spin resonance measurements showing narrow linewidths and good coherence times. [4pt] [1] A. M. Tyryshkin, et al. arXiv: 1105.3772 [2] J. J. L. Morton, et al. Nature (2008) [3] T. Schenkel, et al APL 2006; F. R. Bradbury, et al. PRL (2006) [4] R. E. George, et al. PRL (2010) [5] G. W. Morley, et al. Nat Mat (2010) [6] M. Hatridge, et al. PRB (2011), R. Vijay, et al. APL (2010) This work was supported by NSA (100000080295) and DOE (DE-AC02-05CH11231).

  11. State-of-the-art mass determination of 28Si spheres for the Avogadro project

    NASA Astrophysics Data System (ADS)

    Picard, A.; Barat, P.; Borys, M.; Firlus, M.; Mizushima, S.

    2011-04-01

    For a new determination of the Avogadro constant to play a role in the future redefinition and realization of the mass unit, the mass measurements involved need to be carried out at a very high level of accuracy. From a mass comparison among two 1 kg 28Si spheres and the 1 kg platinum-iridium (Pt/Ir) mass standards, the mass of the spheres must be determined with a combined standard uncertainty of less than 5 µg. The BIPM, the PTB and the NMIJ have carried out such a state-of-the-art mass comparison in air and under vacuum in order to reach this target set by the International Avogadro Coordination (IAC). The results obtained for the spheres AVO28-S5 and AVO28-S8 involved in the comparison have demonstrated that by using air buoyancy artefacts and sorption artefacts it is possible to achieve a relative uncertainty of 4.1 × 10-9. The reference value for each sphere has been determined, taking into account the traceability of the masses to the International Prototype of the kilogram, { K} , in due consideration of the correlations among 17 standards used directly or indirectly in this comparison.

  12. α-particle elastic scattering from 12C, 16O, 24Mg, and 28Si

    NASA Astrophysics Data System (ADS)

    Behairy, Kassem O.; Mahmoud, Zakaria M. M.; Anwar, M.

    2017-01-01

    The elastic scattering of α-particle is analyzed in terms of the optical model over the energy 104-172.2 MeV for 12C, 48.7-146 MeV for 16O, 50-119 MeV for 24Mg, and 104, 166, 120 and 240 MeV for 28Si. We generate the real part of the optical model potential using the single folding model. In the single folding procedure, the ground state density of the target is folded with an effective density dependent α-nucleon interaction. For the imaginary part, the usual Woods-Saxon form is used. The parameters of the effective density dependent α-nucleon interaction are determined by fitting the experimental data of elastic scattering. The effective interaction's parameters are optimized using the χ2 criterion. We reasonably reproduce the elastic scattering cross sections for all studied systems. The obtained results reflect the success of our obtained α-nucleon effective interaction.

  13. Study of the properties of the superheavy nuclei Z = 117 produced in the 249Bk + 48Ca reaction

    NASA Astrophysics Data System (ADS)

    Oganessian, Yu. Ts.; Abdullin, F. Sh.; Alexander, C.; Binder, J.; Boll, R. A.; Dmitriev, S. N.; Ezold, J.; Felker, K.; Gostic, J. M.; Grzywacz, R. K.; Hamilton, J. H.; Henderson, R. A.; Itkis, M. G.; Miernik, K.; Miller, D.; Moody, K. J.; Polyakov, A. N.; Ramayya, A. V.; Roberto, J. B.; Ryabinin, M. A.; Rykaczewski, K. P.; Sagaidak, R. N.; Shaughnessy, D. A.; Shirokovsky, I. V.; Shumeiko, M. V.; Stoyer, M. A.; Stoyer, N. J.; Subbotin, V. G.; Sukhov, A. M.; Tsyganov, Yu. S.; Utyonkov, V. K.; Voinov, A. A.; Vostokin, G. K.

    2014-03-01

    The reaction of 249Bk with 48Ca have been reinvestigated to provide new evidence for the discovery of element 117 on a larger number of events. The experiments were performed at five projectile energies and with a total beam dose of 48Ca of about 4.6×1019. Two isotopes 293,294117 were synthesized in the 249Bk+48Ca reaction, providing excitation functions and α-decay spectra of the produced isotopes that establishes these nuclei to be the products of the 4n- and 3n-evaporation channels, respectively. Decay properties of 293,294117 and of all the daughter products agree with the data of the experiment in which these nuclei were synthesized for the first time in 2010. The new 289115 events, populated by α decay of 293117, demonstrate the same decay properties as those observed for 289115 produced in the 243Am(48Ca,2n) reaction thus providing crossbombardment evidence. In addition, a single decay of 294118 was observed from the reaction with 249Cf - a result of the in-growth of 249Cf in the 249Bk target.

  14. The abundance of 28Si32S, 29Si32S, 28Si34S, and 30Si32S in the inner layers of the envelope of IRC+10216

    PubMed Central

    Fonfría, J. P.; Cernicharo, J.; Richter, M. J.; Fernández-López, M.; Prieto, L. Velilla; Lacy, J. H.

    2016-01-01

    We present high spectral resolution mid-IR observations of SiS towards the C-rich AGB star IRC+10216 carried out with the Texas Echelon-cross-Echelle Spectrograph mounted on the NASA Infrared Telescope Facility. We have identified 204 ro-vibrational lines of 28Si32S, 26 of 29Si32S, 20 of 28Si34S, and 15 of 30Si32S in the frequency range 720 – 790 cm−1. These lines belong to bands v = 1 – 0, 2 – 1, 3 – 2, 4–3, and 5–4, and involve rotational levels with Jlow ≲ 90. About 30 per cent of these lines are unblended or weakly blended and can be partially or entirely fitted with a code developed to model the mid-IR emission of a spherically symmetric circumstellar envelope composed of expanding gas and dust. The observed lines trace the envelope at distances to the star ≲ 35R⋆(≃ 0″.7). The fits are compatible with an expansion velocity of 1+2.5(r/R⋆ −1) km s−1 between 1 and 5R⋆, 11 km s−1 between 5 and 20R⋆, and 14.5 km s−1 outwards. The derived abundance profile of 28Si32S with respect to H2 is 4.9 × 10−6 between the stellar photosphere and 5R⋆, decreasing linearly down to 1.6 × 10−6 at 20R⋆ and to 1.3 × 10−6 at 50R⋆. 28Si32S seems to be rotationally under LTE in the region of the envelope probed with our observations and vibrationally out of LTE in most of it. There is a red-shifted emission excess in the 28Si32S lines of band v = 1 – 0 that cannot be found in the lines of bands v = 2 – 1, 3 – 2, 4 – 3, and 5 – 4. This excess could be explained by an enhancement of the vibrational temperature around 20R⋆ behind the star. The derived isotopic ratios 28Si/29Si, and 32S/34S are 17 and 14, compatible with previous estimates. PMID:26997679

  15. The abundance of 28Si32S, 29Si32S, 28Si34S, and 30Si32S in the inner layers of the envelope of IRC+10216

    NASA Astrophysics Data System (ADS)

    Fonfría, J. P.; Cernicharo, J.; Richter, M. J.; Fernández-López, M.; Velilla Prieto, L.; Lacy, J. H.

    2015-10-01

    We present high spectral resolution mid-IR observations of SiS towards the C-rich AGB star IRC+10216 carried out with the Texas Echelon-cross-Echelle Spectrograph mounted on the NASA Infrared Telescope Facility. We have identified 204 ro-vibrational lines of 28Si32S, 26 of 29Si32S, 20 of 28Si34S, and 15 of 30Si32S in the frequency range 720-790 cm-1. These lines belong to bands v = 1-0, 2-1, 3-2, 4-3, and 5-4, and involve rotational levels with Jlow ≲ 90. About 30 per cent of these lines are unblended or weakly blended and can be partially or entirely fitted with a code developed to model the mid-IR emission of a spherically symmetric circumstellar envelope composed of expanding gas and dust. The observed lines trace the envelope at distances to the star ≲35R⋆ (≃0.7 arcsec). The fits are compatible with an expansion velocity of 1 + 2.5(r/R⋆ - 1) km s-1 between 1 and 5R⋆, 11 km s-1 between 5 and 20R⋆, and 14.5 km s-1 outwards. The derived abundance profile of 28Si32S with respect to H2 is 4.9 × 10-6 between the stellar photosphere and 5R⋆, decreasing linearly down to 1.6 × 10-6 at 20R⋆ and to 1.3 × 10-6 at 50R⋆. 28Si32S seems to be rotationally under local thermodynamic equilibrium (LTE) in the region of the envelope probed with our observations and vibrationally out of LTE in most of it. There is a red-shifted emission excess in the 28Si32S lines of band v = 1-0 that cannot be found in the lines of bands v = 2-1, 3-2, 4-3, and 5-4. This excess could be explained by an enhancement of the vibrational temperature around 20R⋆ behind the star. The derived isotopic ratios 28Si/29Si, and 32S/34S are 17 and 14, compatible with previous estimates.

  16. No-Core Shell Model for 48-Ca, 48-Sc and 48-Ti

    SciTech Connect

    Popescu, S; Stoica, S; Vary, J P; Navratil, P

    2004-10-26

    The authors report the first no-core shell model results for {sup 48}Ca, {sup 48}Sc and {sup 48}Ti with derived and modified two-body Hamiltonians. We use an oscillator basis with a limited {bar h}{Omega} range around 40/A{sup 1/3} = 11 MeV and a limited model space up to 1 {bar h}{Omega}. No single-particle energies are used. They find that the charge dependence of the bulk binding energy of eight A = 48 nuclei is reasonably described with an effective Hamiltonian derived from the CD-Bonn interaction while there is an overall underbinding by about 0.4 MeV/nucleon. However, resulting spectra exhibit deficiencies that are anticipated due to: (1) basis space limitations and/or the absence of effective many-body interactions; and, (2) the absence of genuine three-nucleon interactions. They introduce phenomenological modifications to obtain fits to total binding and low-lying spectra. The resulting no-core shell model opens a path for applications to experiments such as the double-beta ({beta}{beta}) decay process.

  17. Background Studies of CANDLES for Double Beta Decays of 48Ca

    NASA Astrophysics Data System (ADS)

    Kakubata, Hidekazu; Candles Collaboration

    2014-09-01

    An underground observatory is the most effective to perform low background experiments because an underground environment avoids cosmic muon. Backgrounds still remain in this environment, so to grasp their origin and intensity is necessary. We perform the CANDLES experiment in the Kamioka Underground Laboratory to search for 0 νββ of 48Ca, which has the highest Q-value (4.27 MeV) of all ββ nuclides. Here we must consider backgrounds in the energy region around the Q-value. On the CANDLES detector, internal backgrounds from radial contamination in CaF2 crystal scintillators can be restrained to a level free from problems. However, other backgrounds were observed in the energy region higher than the Q-value and peak structure is found in 7 ~ 8 MeV. We inferred that γ-rays emitted by neutron capture reactions on Fe is the main origin of backgrounds. To confirm this hypothesis, we carried out special run using 252Cf neutron source set outside the detector. As a result, we found that the source of these backgrounds is γ-ray from neutron capture on the surrounding material of the detector, especially on the rock and the stainless. For further background reduction, we plan to install additional passive neutron and γ-ray shields. An underground observatory is the most effective to perform low background experiments because an underground environment avoids cosmic muon. Backgrounds still remain in this environment, so to grasp their origin and intensity is necessary. We perform the CANDLES experiment in the Kamioka Underground Laboratory to search for 0 νββ of 48Ca, which has the highest Q-value (4.27 MeV) of all ββ nuclides. Here we must consider backgrounds in the energy region around the Q-value. On the CANDLES detector, internal backgrounds from radial contamination in CaF2 crystal scintillators can be restrained to a level free from problems. However, other backgrounds were observed in the energy region higher than the Q-value and peak structure is found

  18. Determination of Low Loss in Isotopically Pure Single Crystal 28Si at Low Temperatures and Single Microwave Photon Energy

    PubMed Central

    Kostylev, Nikita; Goryachev, Maxim; Bulanov, Andrey D.; Gavva, Vladimir A.; Tobar, Michael E.

    2017-01-01

    The low dielectric losses of an isotopically pure single crystal 28Si sample were determined at a temperature of 20 mK and at powers equivalent to that of a single photon. Whispering Gallery Mode (WGM) analysis revealed large Quality Factors of order 2 × 106 (dielectric loss ~5 × 10−7) at high powers, degrading to 7 × 10−5 (dielectric loss ~1.4 × 10−6 at single photon energy. A very low-loss narrow line width paramagnetic spin flip transition was detected with extreme sensitivity in 28Si, with very small concentration below 1010 cm−3 (less than 10 parts per trillion) and g-factor of 1.995 ± 0.008. Such determination was only possible due to the low dielectric photonic losses combined with the long lifetime of the spin transition (low magnetic loss), which enhances the magnetic AC susceptibility. Such low photonic loss at single photon energy combined with the narrow line width of the spin ensemble, indicate that single crystal 28Si could be an important crystal for future cavity QED experiments. PMID:28317908

  19. Determination of Low Loss in Isotopically Pure Single Crystal (28)Si at Low Temperatures and Single Microwave Photon Energy.

    PubMed

    Kostylev, Nikita; Goryachev, Maxim; Bulanov, Andrey D; Gavva, Vladimir A; Tobar, Michael E

    2017-03-20

    The low dielectric losses of an isotopically pure single crystal (28)Si sample were determined at a temperature of 20 mK and at powers equivalent to that of a single photon. Whispering Gallery Mode (WGM) analysis revealed large Quality Factors of order 2 × 10(6) (dielectric loss ~5 × 10(-7)) at high powers, degrading to 7 × 10(-5) (dielectric loss ~1.4 × 10(-6) at single photon energy. A very low-loss narrow line width paramagnetic spin flip transition was detected with extreme sensitivity in (28)Si, with very small concentration below 10(10) cm(-3) (less than 10 parts per trillion) and g-factor of 1.995 ± 0.008. Such determination was only possible due to the low dielectric photonic losses combined with the long lifetime of the spin transition (low magnetic loss), which enhances the magnetic AC susceptibility. Such low photonic loss at single photon energy combined with the narrow line width of the spin ensemble, indicate that single crystal (28)Si could be an important crystal for future cavity QED experiments.

  20. Fission of nuclei with Z=102-112 produced in reactions with {sup 22}Ne and {sup 48}Ca ions

    SciTech Connect

    Itkis, M. G.; Oganessian, Yu. Ts.; Kozulin, E. M.; Kondratiev, N. A.; Krupa, L.; Pokrovsky, I. V.; Polyakov, A. N.; Ponomarenko, V. A.; Prokhorova, E. V.; Pustylnik, B. I.; Vakatov, V. I.; Rusanov, A. Ya.

    1998-12-21

    The talk presents new results obtained in the study of fission of superheavy nuclei {sup 256}No, {sup 270}Sg and {sup 286}112 formed in reactions with {sup 22}Ne and {sup 48}Ca ions at energies near or considerably lower than the Coulomb barrier. The experiments have been performed at the U-400 accelerator of the Flerov Laboratory of Nuclear Reactions (FLNR) with the use of the time-of-flight spectrometer of fission fragments CORSET.

  1. Production and decay of the heaviest odd-Z nuclei in the 249Bk + 48Ca reaction

    NASA Astrophysics Data System (ADS)

    Oganessian, Yu Ts; Abdullin, F. Sh; Alexander, C.; Binder, J.; Boll, R. A.; Dmitriev, S. N.; Ezold, J.; Felker, K.; Gostic, J. M.; Grzywacz, R. K.; Hamilton, J. H.; Henderson, R. A.; Itkis, M. G.; Miernik, K.; Miller, D.; Moody, K. J.; Polyakov, A. N.; Ramayya, A. V.; Roberto, J. B.; Ryabinin, M. A.; Rykaczewski, K. P.; Sagaidak, R. N.; Shaughnessy, D. A.; Shirokovsky, I. V.; Shumeiko, M. V.; Stoyer, M. A.; Stoyer, N. J.; Subbotin, V. G.; Sukhov, A. M.; Tsyganov, Yu S.; Utyonkov, V. K.; Voinov, A. A.; Vostokin, G. K.

    2015-02-01

    The reaction of 249Bk with 48Ca has been investigated with an aim of synthesizing and studying the decay properties of isotopes of the new element 117. The experiments were performed at five projectile energies (in two runs, in 2009-2010 and 2012) and with a total beam dose of 48Ca ions of about 9x1019 The experiments yielded data on a-decay characteristics and excitation functions of the produced nuclei that establish these to be 293117 and 294117 - the products of the 4n- and 3n-evaporation channels, respectively. In total, we have observed 20 decay chains of Z=117 nuclides. The cross sections were measured to be 1.1 pb for the 3n and 2.4 pb for the 4n-reaction channel. The new 289115 events, populated by α decay of 117, demonstrate the same decay properties as those observed for 115 produced in the 243Am(48Ca,2n) reaction thus providing cross-bombardment evidence. In addition, a single decay of 294118 was observed from the reaction with 249Cf - a result of the in-growth of 249Cf in the 249Bk target. The observed decay chain of 294118 is in good agreement with decay properties obtained in 2002-2005 in the experiments with the reaction 249Cf(48Ca,3n)294118. The energies and half-lives of the odd-Z isotopes observed in the 117 decay chains together with the results obtained for lower-Z superheavy nuclei demonstrate enhancement of nuclear stability with increasing neutron number towards the predicted new magic number N=184.

  2. Lifetime measurements using the CLARA-PRISMA setup around the {sup 48}Ca doubly-magic nucleus

    SciTech Connect

    Valiente-Dobon, J. J.; Gadea, A.; Stefanini, A. M.; Corradi, L.; De Angelis, G.; Fioretto, E.; Grodner, E.; Mason, P.; Napoli, D. R.; Recchia, F.; Sahin, E.; Mengoni, D.; Farnea, E.; Bazzacco, D.; Montagnoli, G.; Ur, C. A.; Lenzi, S. M.; Lunardi, S.; Scarlassara, F.; Dewald, A.

    2008-11-11

    The lifetimes of the first excited states of nuclei around the doubly-magic nucleus {sup 48}Ca have been determined using a novel method that combines the Recoil Distance Doppler Shift (RDDS) method with the CLARA-PRISMA spectrometers. This is the first time such a method is applied to measure lifetimes of neutron-rich nuclei populated via a multinucleon transfer reaction. This novel method and some preliminary results on lifetimes are presented.

  3. Coulomb Sum Rule for 40Ca, 48Ca, and 56Fe for |q-->|<=550 MeV/c

    NASA Astrophysics Data System (ADS)

    Meziani, Z. E.; Barreau, P.; Bernheim, M.; Morgenstern, J.; Turck-Chieze, S.; Altemus, R.; McCarthy, J.; Orphanos, L. J.; Whitney, R. R.; Capitani, G. P.; de Sanctis, E.; Frullani, S.; Garibaldi, F.

    1984-06-01

    Deep-inelastic electron scattering from 40Ca, 48Ca, and 56Fe has been measured at 60°, 90°, and 140° and at inelasticities up to and including the Δ(3, 3) region. Longitudinal response functions in the momentum interval 300 MeV/c<|q-->|<600 MeV/c were extracted. The experimental Coulomb sum rule is observed between the two calcium isotopes.

  4. Production of cold target-like fragments in the reaction of /sup 48/Ca+/sup 248/Cm

    SciTech Connect

    Gaeggeler, H.; Bruechle, W.; Bruegger, M.; Schaedel, M.; Suemmerer, K.; Wirth, G.; Kratz, J.V.; Lerch, M.; Blaich, T.; Herrmann, G.

    1986-06-01

    Yields for isotopes of Rn through Pu have been measured in the reaction /sup 48/Ca+/sup 248/Cm at an energy of 248--263 MeV (1.04--1.10 times the Coulomb barrier). Despite the low bombarding energy, high and essentially constant integral yields of about 1 to 2 mb for the elements Rn through U were observed. There is evidence that these nuclides are produced with little excitation energy.

  5. Measurements of Dipole Excitations in ^48Ca Between Eγ = 9.5 and 15.3 MeV

    NASA Astrophysics Data System (ADS)

    Tompkins, J. R.; Arnold, C. W.; Karwowski, H. J.; Rich, G. C.; Howell, C. R.; Sobotka, L. G.

    2010-02-01

    ^48Ca photodisintegration cross sections were measured using γ-ray beams of 34 different energies between 9.5 and 15.3 MeV generated with the TUNL High-Intensity γ-ray Source (HIγS). The cross sections were measured with a 2.7 g ^48Ca target enriched to 92% using an array of ^3He proportional-counters embedded in thermalizing polyethylene. The absolute cross sections for the ^48Ca(γ,n) reaction were obtained by normalization to the well known ^2H(γ,n) reaction cross sections. Single neutron emission is the dominant channel in this energy range and its detection provides a measurement of dipole excitation strength such as the previously identified M1 strength at Eγ = 10.22 MeV,footnotetextW.Steffen et al. Nucl. Phys. A 404, 413 (1983). for which a new value will be presented. Structures on the low-energy tail of the E1 GDR were also observed and will be presented. )

  6. Fusion of {sup 48}Ca+{sup 90,96}Zr above and below the Coulomb barrier

    SciTech Connect

    Stefanini, A.M.; Behera, B.R.; Corradi, L.; Fioretto, E.; Gadea, A.; Wu, Y.W.; Scarlassara, F.; Beghini, S.; Montagnoli, G.; Silvestri, R.; Trotta, M.; Szilner, S.; Zhang, H.Q.; Liu, Z.H.; Ruan, M.; Yang, F.; Rowley, N.

    2006-03-15

    Fusion-evaporation cross sections were measured in the two systems {sup 48}Ca+{sup 90,96}Zr in an energy range from well below to well above the Coulomb barrier. The sub-barrier fusion of {sup 48}Ca+{sup 90}Zr is reproduced by coupled-channels calculations including the lowest quadrupole and octupole vibrations of {sup 90}Zr, and using a Woods-Saxon potential with a standard diffuseness parameter a = 0.68 fm. However, the fusion cross sections are overestimated above the barrier. The low-energy slope of the excitation function for {sup 48}Ca+{sup 96}Zr is steeper. This implies a larger diffuseness parameter a = 0.85 fm. Fusion cross sections are well fit in the whole energy range, and the effect of the strong octupole vibration in {sup 96}Zr is predominant. The extracted fusion barrier distributions are reasonably well reproduced by calculations for both systems. A comparison with previous data for {sup 40}Ca+{sup 90,96}Zr is made in an attempt to clarify the role of transfer couplings in sub-barrier fusion.

  7. 243Am + 48Ca: A Second Look at the Rf/Db Data Set

    SciTech Connect

    Henderson, R A; Moody, K J

    2008-01-29

    In December of 2005 a series of experiments were performed at the U400 Cyclotron at the Flerov Laboratory of Nuclear Reactions in Dubna, Russia, using the reaction {sup 243}Am ({sup 48}Ca,3n) {sup 288}115 which, after a sequence of five alpha decays, produces a long-lived ({approx}1d) fission activity that had been detected previously in experiments using the Dubna Gas Filled Recoil Separator (DGFRS). These experiments were attempts to establish the elemental identity of the fissioning species as dubnium (element 105), which in turn confirms the identity of the original parent nucleus as element 115 through genetic correlation of the subsequent alpha decays. A series of approximately 24-hour bombardments were followed by chemical separations designed to isolate the Group Four and Five chemical fractions, and then separate the Nb and Ta fractions, which are Group Five homologues of dubnium and should therefore behave chemically similar. The samples were prepared for alpha and fission measurement and counted for an extended period of time. Fission events were detected in the Ta-like fractions only, which correspond to the fission coming from either the {sup 268}Db isotope directly or long-lived electron-capture decay in {sup 268}Db followed by a short half-life fission of {sup 268}Rf. In May of 2007 the Rf and Db fractions were recounted for very long times on alpha spectrometers to look at what species remained after approximately 1.5 years of time. One of the issues to be resolved was the potential for actinide contamination of the counting samples, which might have adverse affects on the observed data from the original experiment. In the original experiment the samples had significant quantities of {beta}-{gamma} activity which made the absolute identification of the alpha activity in each sample difficult. By allowing the {beta}-{gamma} activity to decay away, it gives us the opportunity to make definitive identifications of any alpha emitting isotopes on the

  8. Note: Effect of hot liner in producing {sup 40,48}Ca beam from RIKEN 18-GHz electron cyclotron resonance ion source

    SciTech Connect

    Ozeki, K. Higurashi, Y.; Kidera, M.; Nakagawa, T.

    2015-01-15

    In order to produce a high-intensity and stable {sup 48}Ca beam from the RIKEN 18-GHz electron cyclotron resonance ion source, we have begun testing the production of a calcium beam using a micro-oven. To minimize the consumption rate of the material ({sup 48}Ca), we introduced the “hot liner” method and investigated the effect of the liner on the material consumption rate. The micro-oven was first used to produce the {sup 48}Ca beam for experiments in the RIKEN radioisotope beam factory, and a stable beam could be supplied for a long time with low consumption rate.

  9. Spin distributions and cross sections of evaporation residues in the 28Si+176Yb reaction

    NASA Astrophysics Data System (ADS)

    Sudarshan, K.; Tripathi, R.; Sodaye, S.; Sharma, S. K.; Pujari, P. K.; Gehlot, J.; Madhavan, N.; Nath, S.; Mohanto, G.; Mukul, I.; Jhingan, A.; Mazumdar, I.

    2017-02-01

    Background: Non-compound-nucleus fission in the preactinide region has been an active area of investigation in the recent past. Based on the measurements of fission-fragment mass distributions in the fission of 202Po, populated by reactions with varying entrance channel mass asymmetry, the onset of non-compound-nucleus fission was proposed to be around ZpZt˜1000 [Phys. Rev. C 77, 024606 (2008), 10.1103/PhysRevC.77.024606], where Zp and Zt are the projectile and target proton numbers, respectively. Purpose: The present paper is aimed at the measurement of cross sections and spin distributions of evaporation residues in the 28Si+176Yb reaction (ZpZt=980 ) to investigate the fusion hindrance which, in turn, would give information about the contribution from non-compound-nucleus fission in this reaction. Method: Evaporation-residue cross sections were measured in the beam energy range of 129-166 MeV using the hybrid recoil mass analyzer (HYRA) operated in the gas-filled mode. Evaporation-residue cross sections were also measured by the recoil catcher technique followed by off-line γ -ray spectrometry at few intermediate energies. γ -ray multiplicities of evaporation residues were measured to infer about their spin distribution. The measurements were carried out using NaI(Tl) detector-based 4π-spin spectrometer from the Tata Institute of Fundamental Research, Mumbai, coupled to the HYRA. Results: Evaporation-residue cross sections were significantly lower compared to those calculated using the statistical model code pace2 [Phys. Rev. C 21, 230 (1980), 10.1103/PhysRevC.21.230] with the coupled-channel fusion model code ccfus [Comput. Phys. Commun. 46, 187 (1987), 10.1016/0010-4655(87)90045-2] at beam energies close to the entrance channel Coulomb barrier. At higher beam energies, experimental cross sections were close to those predicted by the model. Average γ -ray multiplicities or angular momentum values of evaporation residues were in agreement with the

  10. A compilation of information on the {sup 31}P(p,{alpha}){sup 28}Si reaction and properties of excited levels in the compound nucleus {sup 32}S

    SciTech Connect

    Miller, R.E.; Smith, D.L.

    1997-11-01

    This report documents a survey of the literature, and provides a compilation of data contained therein, for the {sup 31}P(p,{alpha}){sup 28}Si reaction. Attention is paid here to resonance states in the compound-nuclear system {sup 32}S formed by {sup 31}P + p, with emphasis on the alpha-particle decay channels, {sup 28}Si + {alpha} which populate specific levels in {sup 28}Si. The energy region near the proton separation energy for {sup 32}S is especially important in this context for applications in nuclear astrophysics. Properties of the excited states in {sup 28}Si are also considered. Summaries of all the located references are provided and numerical data contained in them are compiled in EXFOR format where applicable.

  11. Large-scale production of highly enriched 28Si for the precise determination of the Avogadro constant

    NASA Astrophysics Data System (ADS)

    Becker, P.; Schiel, D.; Pohl, H.-J.; Kaliteevski, A. K.; Godisov, O. N.; Churbanov, M. F.; Devyatykh, G. G.; Gusev, A. V.; Bulanov, A. D.; Adamchik, S. A.; Gavva, V. A.; Kovalev, I. D.; Abrosimov, N. V.; Hallmann-Seiffert, B.; Riemann, H.; Valkiers, S.; Taylor, P.; DeBièvre, P.; Dianov, E. M.

    2006-07-01

    An attempt is described to replace the present definition of the kilogram with the mass of a certain number of silicon atoms. A prerequisite for this is that the Avogadro constant, NA, is determined with a relative uncertainty of better than 2 × 10-8. For the determination, silicon crystals are used. However, the difficulty arising thereby is the measurement of the average molar mass of natural Si. Consequently, a worldwide collaboration has been launched to produce approximately a 5 kg 28Si single crystal with an enrichment factor greater than 99.985% and of sufficient chemical purity so that it can be used to determine NA with the targeted relative measurement uncertainty mentioned above. In the following, the first successful tests of all technological steps will be reported (enrichment of SiF4, distillation into silane and chemical purification, chemical vapour deposition of polycrystalline 28Si, floating zone growth of a dislocation-free single crystal) and new equipment for the production of high-purity 28Si with an enrichment of not less than 99.99% will be described. All steps are well defined by a Technical Road Map (TRM28) and all key results are measured by new mass spectrometric, IR spectroscopic and other chemical and physical methods, such as Hall effect, photoluminescence, laser scattering and x-ray topographic methods (TRM for Analytical Monitoring and Certification, TRM28-AMC). The initial enrichment of the gas is >0.999 95 and the depletion during the entire process is <0.000 05. The isotopic homogeneity is checked by natural Si crystal growth and does, in the enriched sphere, not exceed 5 × 10-10, relatively. The C content of the final material is less than 1015 atoms cm-3 and the specific resistance is 400-1000 Ω cm.

  12. Circuit-quantum electrodynamics with direct magnetic coupling to single-atom spin qubits in isotopically enriched {sup 28}Si

    SciTech Connect

    Tosi, Guilherme Mohiyaddin, Fahd A.; Morello, Andrea; Huebl, Hans

    2014-08-15

    Recent advances in silicon nanofabrication have allowed the manipulation of spin qubits that are extremely isolated from noise sources, being therefore the semiconductor equivalent of single atoms in vacuum. We investigate the possibility of directly coupling an electron spin qubit to a superconducting resonator magnetic vacuum field. By using resonators modified to increase the vacuum magnetic field at the qubit location, and isotopically purified {sup 28}Si substrates, it is possible to achieve coupling rates faster than the single spin dephasing. This opens up new avenues for circuit-quantum electrodynamics with spins, and provides a pathway for dispersive read-out of spin qubits via superconducting resonators.

  13. Device fabrication and transport measurements of FinFETs built with 28Si SOI wafers towards donor qubits in silicon

    SciTech Connect

    Lo, Cheuk Chi; Persaud, Arun; Dhuey, Scott; Olynick, Deirdre; Borondics, Ferenc; Martin, Michael C.; Bechtel, Hans A.; Bokor, Jeffrey; Schenkel, Thomas

    2009-06-10

    We report fabrication of transistors in a FinFET geometry using isotopically purified silicon-28 -on-insulator (28-SOI) substrates. Donor electron spin coherence in natural silicon is limited by spectral diffusion due to the residual 29Si nuclear spin bath, making isotopically enriched nuclear spin-free 28Si substrates a promising candidate for forming spin quantum bit devices. The FinFET architecture is fully compatible with single-ion implant detection for donor-based qubits, and the donor spin-state readout through electrical detection of spin resonance. We describe device processing steps and discuss results on electrical transport measurements at 0.3 K.

  14. Protection of shrimp against white spot syndrome virus (WSSV) with β-1,3-D-glucan-encapsulated vp28-siRNA particles.

    PubMed

    Zhu, Fei; Zhang, Xiaobo

    2012-02-01

    White spot syndrome virus (WSSV) is a major shrimp viral pathogen responsible for large economic losses to shrimp aquaculture all over the world. The RNAi mediated by siRNA contributes a new strategy to control this viral disease. However, the efficient approach to deliver the siRNA into shrimp remains to be addressed. In this investigation, an antiviral vp28-siRNA was encapsulated in β-1,3-D-glucan, and then the β-1,3-D-glucan-encapsulated vp28-siRNA particles (GeRPs) were delivered into Marsupenaeus japonicus shrimp. The results showed that the vp28-siRNA in GeRPs could be released in hemocytes of shrimp. It was found that the GeRPs containing the vp28-siRNA inhibited the replication of WSSV in vivo, which presented a better antiviral activity than the non-encapsulated vp28-siRNA. Further evidence indicated that the mortality of WSSV-infected shrimp was significantly delayed by the GeRPs containing vp28-siRNA. Therefore, our study presented that the glucan-encapsulated siRNA might represent a novel potential therapeutic or preventive approach to control the shrimp disease.

  15. Multinucleon transfer reactions for the {sup 28}Si+{sup 90,94}Zr systems in the region below and near the Coulomb barrier

    SciTech Connect

    Kalkal, Sunil; Mandal, S.; Garg, Ritika; Saxena, Mansi; Goyal, Savi; Verma, S.; Kumar, Suresh; Singh, R.; Madhavan, N.; Jhingan, A.; Nath, S.; Gehlot, J.; Mohanto, Gayatri; Prasad, E.; Sandal, Rohit; Behera, B. R.; Pramanik, U. D.; Sinha, A. K.

    2011-05-15

    Measurements on multinucleon transfer reactions for {sup 28}Si+{sup 90,94}Zr systems were performed at sub- and near-barrier energies. The fact that {sup 90}Zr has a closed neutron shell (N = 50) and {sup 94}Zr has four neutrons outside the closed shell, allows us to investigate the effects of shell closure and pairing correlation on multinucleon transfer mechanism. The experiment was performed with pulsed {sup 28}Si beam using the Heavy Ion Reaction Analyzer (HIRA) at Inter University Accelerator Centre (IUAC), New Delhi. Based on the Q-value considerations, it turned out that pickup channels were neutron transfer whereas stripping channels were proton transfer. For the {sup 28}Si+{sup 90}Zr system, the values of the slope parameter for two-neutron pickup turned out to be less than that for one-neutron pickup. The values of the slope parameter were almost the same for two-, three-, and four-neutron pickup channels in the case of the {sup 28}Si+{sup 94}Zr system. The transfer probabilities in the case of the {sup 28}Si+{sup 94}Zr system were much larger than those for the {sup 28}Si+{sup 90}Zr system, further supporting the fact that there is a correlation between the transfer channels and sub-barrier fusion cross-section enhancement. An odd-even staggering was observed in the extracted transfer probabilities at the barrier radius implying the role of pairing correlation in transfer reactions.

  16. Fusion of the positive Q-value system {sup 36}S+{sup 48}Ca well below the Coulomb barrier

    SciTech Connect

    Stefanini, A. M.; Silvestri, R.; Corradi, L.; Fioretto, E.; Guiot, B.; Montagnoli, G.; Beghini, S.; Mason, P.; Scarlassara, F.; Courtin, S.; Haas, F.; Lebhertz, D.; Marginean, N.; Sagaidak, R. N.; Szilner, S.

    2008-10-15

    The fusion excitation function of {sup 36}S+{sup 48}Ca has been measured from well above the barrier down to very small cross sections at sub-barrier energies. A steady decrease of the fusion cross sections is observed below the barrier with no pronounced change of slope. The logarithmic derivative saturates and does not reach the value expected for a constant astrophysical S-factor. The S-factor does not show any maximum in the measured energy range. Coupled-channels calculations using a Woods-Saxon potential have been performed.

  17. 12C(16O,γ)28Si radiative capture: Structural and statistical aspects of the γ decay

    NASA Astrophysics Data System (ADS)

    Lebhertz, D.; Courtin, S.; Haas, F.; Jenkins, D. G.; Simenel, C.; Salsac, M.-D.; Hutcheon, D. A.; Beck, C.; Cseh, J.; Darai, J.; Davis, C.; Glover, R. G.; Goasduff, A.; Kent, P. E.; Levai, G.; Marley, P. L.; Michalon, A.; Pearson, J. E.; Rousseau, M.; Rowley, N.; Ruiz, C.

    2012-03-01

    The heavy-ion radiative capture reaction 12C(16O,γ)28Si has been studied at three energies Ec.m.=8.5, 8.8, and 9 MeV which are close to the Coulomb barrier. The weak radiative capture process has been identified by measuring the 28Si recoils in the highly selective 0∘ spectrometer DRAGON at TRIUMF (Vancouver). The coincident γ rays have been recorded in the associated BGO array. This has allowed a complete measurement of the γ spectrum and the relative strength of all decay pathways. An important part of the decay through quasibound states close to the particle threshold and the feeding of bound states with particular deformation have been identified for the first time. Comparisons with Monte Carlo simulations allowed the extraction of the full experimental radiative capture cross section. Our results suggest an important contribution of spins Jπ=5- and 6+ in the entrance channel. The surprisingly large cross sections from 12 μb at Ec.m.=8.5 MeV to 25 μb at Ec.m.=9.0 MeV for the heavy-ion radiative capture process are discussed in terms of the interplay between statistical and structural aspects of the process.

  18. Stark shift and field ionization of arsenic donors in {sup 28}Si-silicon-on-insulator structures

    SciTech Connect

    Lo, C. C. Morton, J. J. L.; Simmons, S.; Lo Nardo, R.; Weis, C. D.; Schenkel, T.; Tyryshkin, A. M.; Lyon, S. A.; Meijer, J.; Rogalla, D.; Bokor, J.

    2014-05-12

    We develop an efficient back gate for silicon-on-insulator (SOI) devices operating at cryogenic temperatures and measure the quadratic hyperfine Stark shift parameter of arsenic donors in isotopically purified {sup 28}Si-SOI layers using such structures. The back gate is implemented using MeV ion implantation through the SOI layer forming a metallic electrode in the handle wafer, enabling large and uniform electric fields up to 2 V/μm to be applied across the SOI layer. Utilizing this structure, we measure the Stark shift parameters of arsenic donors embedded in the {sup 28}Si-SOI layer and find a contact hyperfine Stark parameter of η{sub a} = −1.9 ± 0.7 × 10{sup −3} μm{sup 2}/V{sup 2}. We also demonstrate electric-field driven dopant ionization in the SOI device layer, measured by electron spin resonance.

  19. Volume measurements of 28Si spheres using an interferometer with a flat etalon to determine the Avogadro constant

    NASA Astrophysics Data System (ADS)

    Kuramoto, N.; Fujii, K.; Yamazawa, K.

    2011-04-01

    The volumes of two 1 kg silicon spheres, AVO28-S5 and AVO28-S8, fabricated from a 28Si-enriched crystal were measured to determine the Avogadro constant by the x-ray crystal density method in the International Avogadro Coordination Project. The volumes were determined from diameter measurements of the two spheres using a laser interferometer with a flat etalon. In the diameter measurement, the sphere was placed between the two flat etalon plates. The gaps between the sphere and the etalon plates and the distance between the etalon plates were measured by phase-shifting interferometry with optical frequency tuning. The apparent volumes of the 28Si spheres were determined from the diameter measurement in many directions with relative combined standard uncertainties of 5.0 × 10-8 and 4.4 × 10-8 for AVO28-S5 and AVO28-S8, respectively. The effect of the surface layer on the diameter measurement was evaluated on the basis of the results of characterizing the sphere surface. By taking into account the effect of the surface layer, the silicon core volume excluding the surface layer and the actual volume including the surface layer were also determined. Details of the interferometer, data analysis and the uncertainty in the measurement are described.

  20. Dynamic polarization potential effects on vector analyzing powers of 6Li- 28Si elastic scattering from non-monotonic potentials

    NASA Astrophysics Data System (ADS)

    Basak, A. K.; Roy, P. K.; Hossain, S.; Abdullah, M. N. A.; Tariq, A. S. B.; Uddin, M. A.; Reichstein, I.; Malik, F. B.

    2010-08-01

    Experimental cross section (CS) and vector analyzing power (VAP) data of the 6Li-28Si elastic scattering at 22.8 MeV are analyzed in the coupled-channels (CC) and coupled discretized continuum channels (CDCC) methods. Non-monotonic (NM) 6Li and α potentials of microscopic origin are employed, respectively, in the CC calculations and to generate folding potentials for the CDCC calculations. The study demonstrates that the use of central NM potentials can generate an appropriate dynamic polarization potential (DPP) required to describe both the CS and VAP data without the necessity of renormalization. This also produces an effective spin-orbit (SO) potential to account for the iT11 data without the requirement of an additional static SO potential at the incident energy considered.

  1. Elastic scattering measurements for the system {sup 7}Be+{sup 28}Si at 17.2 MeV

    SciTech Connect

    Sgouros, O.; Pakou, A.; Aslanoglou, X.; Soukeras, V.; Pierroutsakou, D.; Boiano, A.; Mazzocco, M.; Parascandolo, C.; Signorini, C.; Strano, E.; Torresi, D.; Acosta, L.; Marquinez-Duran, G.; Martel, I.; Boiano, C.; Grebosz, J.; Keeley, N.; Strojek, I.; La Commara, M.; Rusek, K.; and others

    2015-02-24

    Elastic scattering of {sup 7}Be+{sup 28}Si was studied at several near barrier energies for probing the energy dependence of the optical potential. Our analysis at 17.2 MeV will be presented in this article and discussed, in terms of Continuum Coupled Channel Calculations (CDCC). This research is part of a long term plan concerning the energy dependence of the optical potential for weakly bound projectiles, at near barrier energies and for probing the potential threshold anomaly. The experiment took place at the EXOTIC facility - Laboratori Nationali di Legnaro (LNL), and refers to an angular distribution measurement, using the detector array EXPADES (Exotic Particle Detection System). Results at 9 MeV (Rutherford region) were also analyzed and were used for estimating the solid angle. Our analysis for other energies is under process.

  2. Elastic scattering measurements for the system 7Be +28Si at 17.2 MeV

    NASA Astrophysics Data System (ADS)

    Sgouros, O.; Pakou, A.; Pierroutsakou, D.; Mazzocco, M.; Acosta, L.; Aslanoglou, X.; Boiano, A.; Boiano, C.; Grebosz, J.; Keeley, N.; La Commara, M.; Marquinez-Duran, G.; Martel, I.; Parascandolo, C.; Rusek, K.; Sánchez-Benítez, A. M.; Signorini, C.; Soukeras, V.; Stiliaris, E.; Strano, E.; Strojek, I.; Torresi, D.

    2015-02-01

    Elastic scattering of 7Be +28Si was studied at several near barrier energies for probing the energy dependence of the optical potential. Our analysis at 17.2 MeV will be presented in this article and discussed, in terms of Continuum Coupled Channel Calculations (CDCC). This research is part of a long term plan concerning the energy dependence of the optical potential for weakly bound projectiles, at near barrier energies and for probing the potential threshold anomaly. The experiment took place at the EXOTIC facility - Laboratori Nationali di Legnaro (LNL), and refers to an angular distribution measurement, using the detector array EXPADES (Exotic Particle Detection System). Results at 9 MeV (Rutherford region) were also analyzed and were used for estimating the solid angle. Our analysis for other energies is under process.

  3. Measurement of the {2 2 0} lattice-plane spacing of a 28Si x-ray interferometer

    NASA Astrophysics Data System (ADS)

    Massa, E.; Mana, G.; Kuetgens, U.; Ferroglio, L.

    2011-04-01

    The spacing of the {2 2 0} lattice planes of a 28Si crystal, used to determine the Avogadro constant by counting silicon atoms, was measured by combined x-ray and optical interferometry to a relative accuracy of 3.5 × 10-9. The result is d2 2 0 = (192 014 712.67 ± 0.67) am, at 20.0 °C and 0 Pa. This value is greater by (1.9464 ± 0.0067) × 10-6d2 2 0 than the spacing in natural Si, a difference which confirms quantum-mechanics calculations. This result is a key step towards a realization of the mass unit based on a conventional value of the Planck or the Avogadro constant.

  4. (30)Si mole fraction of a silicon material highly enriched in (28)Si determined by instrumental neutron activation analysis.

    PubMed

    D'Agostino, Giancarlo; Di Luzio, Marco; Mana, Giovanni; Oddone, Massimo; Pramann, Axel; Prata, Michele

    2015-06-02

    The latest determination of the Avogadro constant, carried out by counting the atoms in a pure silicon crystal highly enriched in (28)Si, reached the target 2 × 10(-8) relative uncertainty required for the redefinition of the kilogram based on the Planck constant. The knowledge of the isotopic composition of the enriched silicon material is central; it is measured by isotope dilution mass spectrometry. In this work, an independent estimate of the (30)Si mole fraction was obtained by applying a relative measurement protocol based on Instrumental Neutron Activation Analysis. The amount of (30)Si isotope was determined by counting the 1266.1 keV γ-photons emitted during the radioactive decay of the radioisotope (31)Si produced via the neutron capture reaction (30)Si(n,γ)(31)Si. The x((30)Si) = 1.043(19) × 10(-6) mol mol(-1) is consistent with the value currently adopted by the International Avogadro Coordination.

  5. Neutron activation analysis of the 30Si content of highly enriched 28Si: proof of concept and estimation of the achievable uncertainty

    NASA Astrophysics Data System (ADS)

    D'Agostino, G.; Mana, G.; Oddone, M.; Prata, M.; Bergamaschi, L.; Giordani, L.

    2014-06-01

    We investigated the use of neutron activation to estimate the 30Si mole fraction of the ultra-pure silicon material highly enriched in 28Si for the measurement of the Avogadro constant. Specifically, we developed a relative method based on instrumental neutron activation analysis and using a natural-Si sample as a standard. To evaluate the achievable uncertainty, we irradiated a 6 g sample of a natural-Si material and modelled experimentally the signal that would be produced by a sample of the 28Si-enriched material of similar mass and subjected to the same measurement conditions. The extrapolation of the expected uncertainty from the experimental data indicates that a measurement of the 30Si mole fraction of the 28Si-enriched material might reach a 4% relative combined standard uncertainty.

  6. Channel coupling effects on the fusion excitation functions for {sup 28}Si+{sup 90,94}Zr in sub- and near-barrier regions

    SciTech Connect

    Kalkal, Sunil; Mandal, S.; Verma, Shashi; Saxena, Mansi; Goyal, Savi; Siwal, Davinder; Garg, Ritika; Kumar, Suresh; Singh, R.; Madhavan, N.; Jhingan, A.; Nath, S.; Gehlot, J.; Varughese, T.; Golda, K. S.; Muralithar, S.; Prasad, E.; Sandal, Rohit; Behera, B. R.; Pramanik, U. D.

    2010-04-15

    Fusion excitation functions and angular distributions of evaporation residues (ERs) have been measured for {sup 28}Si+{sup 90,94}Zr systems around the Coulomb barrier using the recoil mass spectrometer, Heavy Ion Reaction Analyzer (HIRA). For both systems, the experimental fusion cross sections are strongly enhanced compared to the predictions of the one-dimensional barrier penetration model (1-d BPM) below the barrier. Coupled channels formalism has been employed to theoretically explain the observed sub-barrier fusion cross section enhancement. The enhancement could be explained by considering the coupling of the low-lying inelastic states of the projectile and target in the {sup 28}Si+{sup 90}Zr system. In the sub-barrier region, the measured fusion cross sections for {sup 28}Si+{sup 94}Zr turned out to be about an order of magnitude higher than the ones for the {sup 28}Si+{sup 90}Zr system, which could not be explained by coupling to inelastic states alone. This observation indicates the importance of multinucleon transfer reaction channels with positive Q values in the sub-barrier fusion cross section enhancement, because {sup 90,94}Zr are believed to have similar collective strengths. This implies that no strong isotopic dependence of fusion cross sections is expected as far as the couplings to collective inelastic states are concerned. In addition, the role of projectile and multiphonon couplings in the enhancement has been explored.

  7. Predicted yields of new neutron-rich isotopes of nuclei with Z=64-80 in the multinucleon transfer reaction {sup 48}Ca+{sup 238}U

    SciTech Connect

    Adamian, G. G.; Antonenko, N. V.; Sargsyan, V. V.; Scheid, W.

    2010-05-15

    The production cross sections of new neutron-rich isotopes of nuclei with charge numbers Z=64-80 are estimated for future experiments in the multinucleon transfer reaction {sup 48}Ca+{sup 238}U at bombarding energy E{sub c.m.}=189 MeV close to the Coulomb barrier.

  8. Measurement of the double-beta decay half-life and search for the neutrinoless double-beta decay of 48Ca with the NEMO-3 detector

    NASA Astrophysics Data System (ADS)

    Arnold, R.; Augier, C.; Bakalyarov, A. M.; Baker, J. D.; Barabash, A. S.; Basharina-Freshville, A.; Blondel, S.; Blot, S.; Bongrand, M.; Brudanin, V.; Busto, J.; Caffrey, A. J.; Calvez, S.; Cascella, M.; Cerna, C.; Cesar, J. P.; Chapon, A.; Chauveau, E.; Chopra, A.; Duchesneau, D.; Durand, D.; Egorov, V.; Eurin, G.; Evans, J. J.; Fajt, L.; Filosofov, D.; Flack, R.; Garrido, X.; Gómez, H.; Guillon, B.; Guzowski, P.; Hodák, R.; Huber, A.; Hubert, P.; Hugon, C.; Jullian, S.; Klimenko, A.; Kochetov, O.; Konovalov, S. I.; Kovalenko, V.; Lalanne, D.; Lang, K.; Lebedev, V. I.; Lemière, Y.; Le Noblet, T.; Liptak, Z.; Liu, X. R.; Loaiza, P.; Lutter, G.; Mamedov, F.; Marquet, C.; Mauger, F.; Morgan, B.; Mott, J.; Nemchenok, I.; Nomachi, M.; Nova, F.; Nowacki, F.; Ohsumi, H.; Pahlka, R. B.; Perrot, F.; Piquemal, F.; Povinec, P.; Přidal, P.; Ramachers, Y. A.; Remoto, A.; Reyss, J. L.; Richards, B.; Riddle, C. L.; Rukhadze, E.; Rukhadze, N. I.; Saakyan, R.; Salazar, R.; Sarazin, X.; Shitov, Yu.; Simard, L.; Šimkovic, F.; Smetana, A.; Smolek, K.; Smolnikov, A.; Söldner-Rembold, S.; Soulé, B.; Štekl, I.; Suhonen, J.; Sutton, C. S.; Szklarz, G.; Thomas, J.; Timkin, V.; Torre, S.; Tretyak, Vl. I.; Tretyak, V. I.; Umatov, V. I.; Vanushin, I.; Vilela, C.; Vorobel, V.; Waters, D.; Zhukov, S. V.; Žukauskas, A.; NEMO-3 Collaboration

    2016-06-01

    The NEMO-3 experiment at the Modane Underground Laboratory investigates the double-beta decay of 48Ca. Using 5.25 yr of data recorded with a 6.99 g sample of 48Ca, approximately 150 double-beta decay candidate events are selected with a signal-to-background ratio greater than 3. The half-life for the two-neutrino double-beta decay of 48Ca is measured to be T1/2 2 ν=[6. 4-0.6+0.7(stat)-0.9 +1.2(syst ) ]×1 019 yr . A search for neutrinoless double-beta decay of 48Ca yields a null result, and a corresponding lower limit on the half-life is found to be T1/2 0 ν>2.0 ×1 022 yr at 90% confidence level, translating into an upper limit on the effective Majorana neutrino mass of ⟨mβ β⟩<6.0 - 26 eV , with the range reflecting different nuclear matrix element calculations. Limits are also set on models involving Majoron emission and right-handed currents.

  9. Energy loss measurements of 63Cu, 28Si and 27Al heavy ions crossing thin Polyvinylchloride (PVC) foil

    NASA Astrophysics Data System (ADS)

    Dib, A.; Ammi, H.; Guesmia, A.; Msimanga, M.; Mammeri, S.; Hedibel, M.; Guedioura, B.; Pineda-Vargas, C. A.

    2015-11-01

    Experimental stopping data of, 63Cu, 28Si and 27Al heavy ions in thin Polyvinylchloride (H3C2Cl1) foil have been obtained over the 0.045-0.50 MeV/nucleon energy range. The measured energy losses were carried out by Heavy Ion Elastic Recoil Detection Analysis (HI-ERDA) technique coupled with time of flight (ToF) spectrometer. A continuous stopping power data obtained in this work are well fitted by our proposed semi-empirical formula and the results are compared to those calculated by LSS formula or generated by SRIM-2013 and MSTAR predictions. Calculations using our formula agree well with the obtained experimental stopping powers, while the LSS formula underestimates the experimental data in the whole investigated energy range. In this work a simple expression for electronic stopping power of heavy ions at low energy in solid targets is introduced. This formula is based on the Firsov and Lindhard-Sharff stopping power models with a small modification made to the original expression, by incorporating the effective charge of moving ions concept and with exponential fit function.

  10. Volume measurements of 28Si-enriched spheres using an improved optical interferometer for the determination of the Avogadro constant

    NASA Astrophysics Data System (ADS)

    Kuramoto, Naoki; Azuma, Yasushi; Inaba, Hajime; Fujii, Kenichi

    2017-04-01

    For the determination of the Avogadro constant by the x-ray crystal density method, an accurate volume measurement of 1 kg Si spheres is of primary importance. For this purpose, an optical interferometer was improved and used to measure the volumes of two 1 kg silicon spheres which were manufactured from a silicon crystal highly enriched in 28Si. The apparent volumes of the spheres, which do not take into account the influence of the surface layers on the volume measurement by interferometry, were determined with a relative standard uncertainty of as small as 2.0  ×  10‑8. The surface of the spheres was characterized by using an improved spectroscopic ellipsometer. By considering the influence of the surface layers, the core volumes of the spheres, which exclude the surface layers, were determined. These results were used for the determination of the Avogadro constant in 2015 as a framework organized by the International Avogadro Coordination project. This paper provides details on the measurements, the improvements made to the apparatus, the data analysis and the uncertainty evaluation.

  11. Determination of the atomic weight of 28Si-enriched silicon for a revised estimate of the Avogadro constant.

    PubMed

    Yang, Lu; Mester, Zoltán; Sturgeon, Ralph E; Meija, Juris

    2012-03-06

    The much anticipated overhaul of the International System of Units (SI) will result in new definitions of base units in terms of fundamental constants. However, redefinition of the kilogram in terms of the Planck constant (h) cannot proceed without consistency between the Avogadro and Planck constants, which are both related through the Rydberg constant. In this work, an independent assessment of the atomic weight of silicon in a highly enriched (28)Si crystal supplied by the International Avogadro Coordination (IAC) was performed. This recent analytical approach, based on dissolution with NaOH and its isotopic characterization by multicollector inductively coupled plasma mass spectrometry, is critically evaluated. The resultant atomic weight A(r)(Si) = 27.976 968 39(24)(k=1) differs significantly from the most recent value of A(r)(Si) = 27.976 970 27(23)(k=1). Using the results generated herein for A(r)(Si) along with other IAC measurement results for mass, volume, and the lattice spacing, the estimate of the Avogadro constant becomes N(A) = 6.022 140 40(19) × 10(23) mol(-1).

  12. Fragmentation cross sections of 28Si at beam energies from 290AMeV to 1200A MeV

    SciTech Connect

    Zeitlin, C.; Fukumura, A.; Guetersloh, S.B.; Heilbronn, L.H; Iwata, Y.; Miller, J.; Murukami, T.

    2006-08-25

    In planning for long-duration spaceflight, it will beimportant to accurately model the exposure of astronauts to heavy ions inthe Galactic Cosmic Rays (GCR). As part of an ongoing effort to improveheavy-ion transport codes that will be used in designing futurespacecraft and habitats, fragmentation cross sections of 28Si have beenmeasured using beams with extracted energies from 290A MeV to 1200A MeV,spanning most of the peak region of the energy distribution of siliconions in the GCR. Results were obtained for six elemental targets:hydrogen, carbon, aluminum, copper, tin, and lead. The charge-changingcross sections are found to be energy-independent within the experimentaluncertainties, except for those on the hydrogen target. Cross sectionsfor the heaviest fragments are found to decrease slightly with increasingenergy for lighter targets, but increase with energy for tin and leadtargets. The cross sections are compared to previous measurements atsimilar energies, and to predictions of the NUCFRG2 model used by NASA toevaluate radiation exposures in flight. For charge-changing crosssections, reasonable agreement is found between the present experimentand those of Webber, et al. and Flesch, et al., and NUCFRG2 agrees withthe data to within 3 percent in most cases. Fragment cross sections showless agreement between experiments, and there are substantial differencesbetween NUCFRG2 predictions andthe data.

  13. Measuring the fusion cross-section of 39,47K + 28Si at near barrier energies

    NASA Astrophysics Data System (ADS)

    Vadas, Justin; Singh, Varinderjit; Wiggins, Blake; Huston, Jacob; Hudan, Sylvie; Desouza, Romualdo; Chbihi, Abdou; Ackermann, Dieter; Brown, Kyle

    2017-01-01

    The outer crust of an accreting neutron star provides an interesting environment for nuclear reactions to occur. In particular, the enhancement of fusion between neutron-rich nuclei relative to their β-stable counterparts has been suggested as a trigger for an X-ray superburst. Recently, nuclei in the mass range of A=20-40 have been proposed as the most likely candidates for this process. To investigate this question, comparing the fusion excitation functions for both neutron-rich and β-stable nuclei at energies near the fusion barrier is necessary. The development of a 47K radioactive beam at NSCL's ReA3 facility makes such a comparison possible for the first time. An approved experiment to measure the fusion excitation functions for 39,47K + 28Si will be described. This experiment utilizes a technique optimized for measuring the total fusion cross-section of reactions involving low-intensity (103 - 106 ions/s) radioactive beams. In addition, protons and α particles emitted by the compound nucleus as it de-excites are measured. Preliminary results will be presented. Supported by DOE Grant No. DE-FG02-88ER-40404 and NSF Grant No. 1342962.

  14. Effects of 28Si Ions, 56Fe Ions, and Protons on the Induction of Murine Acute Myeloid Leukemia and Hepatocellular Carcinoma

    PubMed Central

    Weil, Michael M.; Ray, F. Andrew; Genik, Paula C.; Yu, Yongjia; McCarthy, Maureen; Fallgren, Christina M.; Ullrich, Robert L.

    2014-01-01

    Estimates of cancer risks posed to space-flight crews by exposure to high atomic number, high-energy (HZE) ions are subject to considerable uncertainty because epidemiological data do not exist for human populations exposed to similar radiation qualities. We assessed the carcinogenic effects of 300 MeV/n 28Si or 600 MeV/n 56Fe ions in a mouse model for radiation-induced acute myeloid leukemia and hepatocellular carcinoma. C3H/HeNCrl mice were irradiated with 0.1, 0.2, 0.4, or 1 Gy of 300 MeV/n 28Si ions, 600 MeV/n 56Fe ions or 1 or 2 Gy of protons simulating the 1972 solar particle event (1972SPE) at the NASA Space Radiation Laboratory. Additional mice were irradiated with 137Cs gamma rays at doses of 1, 2, or 3 Gy. All groups were followed until they were moribund or reached 800 days of age. We found that 28Si or 56Fe ions do not appear to be substantially more effective than gamma rays for the induction of acute myeloid leukemia. However, 28Si or 56Fe ion irradiated mice had a much higher incidence of hepatocellular carcinoma than gamma ray irradiated or proton irradiated mice. These data demonstrate a clear difference in the effects of these HZE ions on the induction of leukemia compared to solid tumors, suggesting potentially different mechanisms of tumorigenesis. Also seen in this study was an increase in metastatic hepatocellular carcinoma in the 28Si and 56Fe ion irradiated mice compared with those exposed to gamma rays or 1972SPE protons, a finding with important implications for setting radiation exposure limits for space-flight crew members. PMID:25126721

  15. Recoil-α-fission and recoil-α-α-fission events observed in the reaction 48Ca + 243Am

    NASA Astrophysics Data System (ADS)

    Forsberg, U.; Rudolph, D.; Andersson, L.-L.; Di Nitto, A.; Düllmann, Ch. E.; Fahlander, C.; Gates, J. M.; Golubev, P.; Gregorich, K. E.; Gross, C. J.; Herzberg, R.-D.; Heßberger, F. P.; Khuyagbaatar, J.; Kratz, J. V.; Rykaczewski, K.; Sarmiento, L. G.; Schädel, M.; Yakushev, A.; Åberg, S.; Ackermann, D.; Block, M.; Brand, H.; Carlsson, B. G.; Cox, D.; Derkx, X.; Dobaczewski, J.; Eberhardt, K.; Even, J.; Gerl, J.; Jäger, E.; Kindler, B.; Krier, J.; Kojouharov, I.; Kurz, N.; Lommel, B.; Mistry, A.; Mokry, C.; Nazarewicz, W.; Nitsche, H.; Omtvedt, J. P.; Papadakis, P.; Ragnarsson, I.; Runke, J.; Schaffner, H.; Schausten, B.; Shi, Yue; Thörle-Pospiech, P.; Torres, T.; Traut, T.; Trautmann, N.; Türler, A.; Ward, A.; Ward, D. E.; Wiehl, N.

    2016-09-01

    Products of the fusion-evaporation reaction 48Ca + 243Am were studied with the TASISpec set-up at the gas-filled separator TASCA at the GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany. Amongst the detected thirty correlated α-decay chains associated with the production of element Z = 115, two recoil-α-fission and five recoil- α- α-fission events were observed. The latter five chains are similar to four such events reported from experiments performed at the Dubna gas-filled separator, and three such events reported from an experiment at the Berkeley gas-filled separator. The four chains observed at the Dubna gas-filled separator were assigned to start from the 2n-evaporation channel 289115 due to the fact that these recoil- α- α-fission events were observed only at low excitation energies. Contrary to this interpretation, we suggest that some of these recoil- α- α-fission decay chains, as well as some of the recoil- α- α-fission and recoil-α-fission decay chains reported from Berkeley and in this article, start from the 3n-evaporation channel 288115.

  16. Search for the isovector monopole resonance via the 28Si(10Be,10B+ γ)28Al reaction

    NASA Astrophysics Data System (ADS)

    Scott, Michael; e11021 Collaboration Team

    2013-10-01

    The isovector giant monopole resonance (IVGMR) is a fundamental mode of collective oscillation in which the neutron and proton fluids in a nucleus radially expand and contract in an out-of-phase manner. Observation of the IVGMR has been difficult due to the lack of a probe that will excite only its non-spin-flip (ΔS = 0) transitions. The IVGMR's spin-transfer (ΔS = 1) counterpart, the isovector spin giant monopole resonance, is much more strongly excited at bombarding energies higher than 60 MeV/ u. By way of the (10Be,10B+ γ) charge-exchange reaction, the selectivity for the excitation of the IVGMR can be gained. In this probe, the superallowed Fermi transition 10Be(0+,g.s.) -->10B(01+,1.74 MeV, T = 1) allows a nearly pure isolation of the ΔS = 0 component by detecting the 1022 keV gamma rays from the deexcitation of the 10B. We measured the double differential cross sections for the 28Si(10Be,10B+ γ) reaction at 100 MeV/ u using the large acceptance S800 Spectrometer at the National Superconducting Cyclotron Laboratory with the GRETINA array detecting the gamma rays emitted from the 10B ejectile. In this presentation, we will report preliminary reults of the IVGMR in 28Al. GRETINA was funded by the US DOE - Office of Science. Operation of the array at NSCL is supported by NSF under Cooperative Agreement PHY-1102511(NSCL) and DOE under grant DE-AC02-05CH11231(LBNL).

  17. Semi empirical formula for electronic stopping power determination of 24Mg, 27Al and 28Si ions crossing Formvar foil in the ion energy domain of LSS theory

    NASA Astrophysics Data System (ADS)

    Guesmia, A.; Ammi, H.; Mammeri, S.; Dib, A.; Pineda-Vargas, C. A.; Msimanga, M.; Hedibel, M.

    2014-03-01

    We have determined continuous stopping power of heavy ions in thin Formvar foil for 28Si, 27Al and 24Mg ions over an energy range of (0.1-0.5) MeV/nucleon. Heavy Ions Elastic Recoil Detection Analysis (HI-ERDA) technique coupled with time of flight (ToF) spectrometer has been used to measure energy loss of charged particles in this thin absorber. Lindhard, Scharff and Schiott (LSS) theory compared with the corresponding determined stopping values in Formvar, shows significantly large deviations. However, a novel semi empirical expression has been proposed here and tested for better stopping power calculations at low velocity in the ion energy domain of LSS theory for 28Si, 27Al and 24Mg ions crossing thin Formvar foil. The results were compared to the obtained experimental stopping power data, predictions of LSS theory and also to those generated by SRIM-2010 computer code. The obtained results exhibit good agreement with experimental data.

  18. Microscopic model analysis of the 6He, 6Li+28Si total reaction cross sections at the energy range 5-50 A MeV

    SciTech Connect

    Lukyanov, K. V.; Kukhtina, I. N.; Lukyanov, V. K.; Penionzhkevich, Yu. E.; Sobolev, Yu. G.; Zemlyanaya, E. V.

    2007-05-22

    The existing and some preliminary experimental data on the total cross sections of the 4,6He, 6,7Li+28Si reactions at energies E=5-50 A MeV are demonstrated. The data on 6Li,6He+28Si are analyzed in the framework of the microscopic optical potential with real and imaginary parts obtained with a help of the double-folding procedure and by using the current models of densities of the projectile nuclei. Besides, the microscopic double-folding Coulomb potential is calculated and its effect on cross sections is compared with that when one applies the traditional Coulomb potential of the uniform charge distribution. The semi-microscopic potentials are constructed from both the renormalized microscopic potentials and their derivatives to take into account collective motion effect and to improve an agreement with experimental data.

  19. Measurements and coupled reaction channels analysis of one- and two-proton transfer reactions for the 28Si + 90,94Zr systems

    NASA Astrophysics Data System (ADS)

    Kalkal, Sunil; Mandal, S.; Jhingan, A.; Gehlot, J.; Sugathan, P.; Golda, K. S.; Madhavan, N.; Garg, Ritika; Goyal, Savi; Mohanto, Gayatri; Sandal, Rohit; Chakraborty, Santosh; Verma, Shashi; Behera, Bivash; Eleonora, G.; Wollersheim, H. J.; Singh, R.

    2012-03-01

    Measurements of angular distributions for one- and two-proton stripping reactions for 28Si + 90,94Zr systems were performed at 120 MeV. The experiment was carried out with the 28Si beam at Inter University Accelerator Center, New Delhi. The theoretical calculations were performed using the quantum mechanical coupled reaction channels code fresco. The distorted wave Born approximation calculations reproduced the experimental angular distributions for the one-proton transfer channel for both the systems reasonably well but failed for the two-proton transfer channel. Coupled channels calculations including various intermediate states (involving target and projectile inelastic excitations before and/or after transfer) along with the sequential transfer were able to reproduce the two-proton transfer angular distributions for both the systems reasonably well. It seems that at an energy above the Coulomb barrier, there is significant contribution of the indirect multistep and sequential transfer to the two-proton stripping reaction.

  20. Measurements and coupled reaction channels analysis of one and two proton transfer reactions for 28Si+90,94Zr systems

    NASA Astrophysics Data System (ADS)

    Kalkal, Sunil; Mandal, S.; Jhingan, A.; Gehlot, J.; Sugathan, P.; Golda, K. S.; Madhavan, N.; Garg, Ritika; Goyal, Savi; Mohanto, Gayatri; Verma, S.; Sandal, Rohit; Behera, Bivash; Eleonora, G.; Wollersheim, H. J.; Singh, R.

    2011-10-01

    Measurements of angular distributions for one and two proton stripping reactions for 28Si+90,94Zr systems were performed at lab energy 120 MeV with 28Si beam at Inter University Accelerator Center, New Delhi. Theoretical calculations performed using the quantum mechanical coupled reaction channels code FRESCO (including various intermediate states involving target and projectile excitations before and/or after transfer along with sequential transfer) were able to reproduce one and two proton transfer angular distributions for both the systems reasonably well. It was found that the DWBA calculations could describe the one proton transfer data well for both the systems but failed to reproduce the angular distributions for two proton transfer channels. The present measurements underline the importance of sequential transfer at energies much above the Coulomb barrier. We had also performed transfer reaction measurements for these systems in the sub- and near barrier region using recoil mass separator.

  1. Inelastic scattering of 65 MeV protons from /sup 12/C, /sup 24/Mg, /sup 28/Si, and /sup 32/S

    SciTech Connect

    Kato, S.; Okada, K.; Kondo, M.; Hosono, K.; Saito, T.; Matsuoka, N.; Hatanaka, K.; Noro, T.; Nagamachi, S.; Shimizu, H.; Ogino, K.; Kadota, Y.; Matsuki, S.; Wakai, M.

    1985-05-01

    Measurements of angular distributions of the cross sections and analyzing powers for the elastic and inelastic scatterings of 65 MeV polarized protons from /sup 12/C, /sup 24/Mg, /sup 28/Si, and /sup 32/S are reported. Coupled channels analyses of the scattering data are presented assuming the 0/sub 1//sup +/, 2/sub 1//sup +/, and 4/sub 1//sup +/ states to be members of the ground band, the 0/sub 2//sup +/ state to begin the

  2. Excitation functions for production of heavy actinides from interactions of /sup 40/Ca and /sup 48/Ca ions with /sup 248/Cm

    SciTech Connect

    Hoffman, D.C.; Fowler, M.M.; Daniels, W.R.; von Gunten, H.R.; Lee, D.; Moody, K.J.; Gregorich, K.; Welch, R.; Seaborg, G.T.; Bruechle, W.

    1985-05-01

    Excitation functions have been measured for production of isotopes of Bk through Fm in bombardments of /sup 248/Cm with 234- to 294-MeV /sup 40/Ca ions and with 239- to 318-MeV /sup 48/Ca ions. The maxima of the isotopic distributions for these elements occur at only 2 to 3 mass numbers larger for /sup 48/Ca than for /sup 40/Ca reactions. The shapes of the distributions and the half-widths of about 2.5 mass numbers are quite similar to those observed previously for reactions of /sup 16/O, /sup 18/O, /sup 20/Ne, and /sup 22/Ne with /sup 248/Cm. In general, the excitation functions for /sup 40/Ca show maxima near the Coulomb barrier while those for /sup 48/Ca are about 20 MeV above the barrier. The cross sections decrease rather slowly with increasing projectile energy over the energy range studied, indicating that the additional projectile energy is not manifested as excitation energy of these actinide products.

  3. Fische und Fischerzeugnisse

    NASA Astrophysics Data System (ADS)

    Oehlenschläger, Jörg

    Fische und Fischerzeugnisse lassen sich gemäß den "Leitsätzen für Fische, Krebs- und Weichtiere und Erzeugnisse daraus" des Deutschen Lebensmittelbuches einteilen. Tiefgefrorene Fische werden von den "Leitsätzen für tiefgefrorene Fische, Krebs- und Weichtiere und Erzeugnisse daraus" und Salate mit Fleisch von Fischen, Krebs- und/oder Weichtieren durch Abschnitt II.B. der "Leitsätze für Feinkostsalate" abgedeckt. Zu nennen sind: Frischfische, Getrocknete Fische, Räucherfische, Gesalzene Fische, Erzeugnisse aus gesalzenen Fischen, Anchosen, Marinaden, Bratfischwaren, Kochfischwaren, Fischerzeugnisse in Gelee, Pasteurisierte Fischerzeugnisse, Fischdauerkonserven, Erzeugnisse aus Surimi, Krebstiere und Krebstiererzeugnisse, Weichtiere und Weichtiererzeugnisse und tiefgekühlte Fischereierzeugnisse.

  4. The 28Si(p,t)26Si*(p) reaction and implications for the astrophysical 25Al(p,gamma)26Si reaction rate

    SciTech Connect

    Chipps, K.; Bardayan, Daniel W; Chae, K. Y.; Cizewski, J. A.; Kozub, R. L.; Liang, J Felix; Matei, Catalin; Moazen, Brian; Nesaraja, Caroline D; O'Malley, Patrick; Pain, S. D.; Peters, W. A.; Pittman, S. T.; Schmitt, Kyle; Smith, Michael Scott

    2010-10-01

    Several resonances in 25Al(p, )26Si have been studied via the 28Si(p,t)26Si reaction. Triton energies and angular distributions were measured using a segmented annular detector array. An additional silicon detector array was used to simultaneously detect the coincident protons emitted from the decay of states in 26Si above the proton threshold, in order to determine branching ratios. A resonance at 5927 4 keV has been experimentally confirmed as the first = 0 state above the proton threshold, with a proton branching ratio consistent with one.

  5. Late-occurring chromosome aberrations and global DNA methylation in hematopoietic stem/progenitor cells of CBA/CaJ mice exposed to silicon ((28)Si) ions.

    PubMed

    Rithidech, Kanokporn Noy; Honikel, Louise M; Reungpathanaphong, Paiboon; Tungjai, Montree; Jangiam, Witawat; Whorton, Elbert B

    2015-11-01

    Although myeloid leukemia (ML) is one of the major health concerns from exposure to space radiation, the risk prediction for developing ML is unsatisfactory. To increase the reliability of predicting ML risk, a much improved understanding of space radiation-induced changes in the target cells, i.e. hematopoietic stem/progenitor cells (HSPCs), is important. We focused on the in vivo induction of late-occurring damage in HSPCs of mice exposed to (28)Si ions since such damage is associated with radiation-induced genomic instability (a key event of carcinogenesis). We gave adult male CBA/CaJ mice, known to be sensitive to radiation-induced ML, a whole-body exposure (2 fractionated exposures, 15 days apart, that totaled each selected dose, delivered at the dose-rate of 1 cGy/min) to various doses of 300 MeV/n (28)Si ions, i.e. 0 (sham controls), 0.1, 0.25, or 0.5 Gy. At 6 months post-irradiation, we collected bone marrow cells from each mouse (five mice per treatment-group) for obtaining the myeloid-lineage of HSPC-derived clones for analyses. We measured the frequencies of late-occurring chromosome aberrations (CAs), using the genome-wide multicolor fluorescence in situ hybridization method. The measurement of CAs was coupled with the characterization of the global DNA methylation patterns, i.e. 5-methylcytosine (5 mC) and 5-hydroxymethylcytosine (5 hmC). A dose-dependent increase in the frequencies of CAs was detected (Analysis of Variance or ANOVA, p<0.01), indicating the induction of genomic instability after exposure of mice to 300 MeV/n (28)Si ions. Slight increases in the levels of 5 mC were observed in all treatment groups, as compared to the sham-control level. In contrast, there was a significant reduction in levels of 5 hmC (ANOVA, p<0.01). Since these endpoints were evaluated in the same mouse, our data suggested for the first time a link between a reduction in 5 hmC and genomic instability in HSPC-derived myeloid colonies of CBA/CaJ mice exposed to 300 Me

  6. Fusion and quasifission dynamics in the reactions 48Ca+249Bk and 50Ti+249Bk using a time-dependent Hartree-Fock approach

    NASA Astrophysics Data System (ADS)

    Umar, A. S.; Oberacker, V. E.; Simenel, C.

    2016-08-01

    Background: Synthesis of superheavy elements (SHEs) with fusion-evaporation reactions is strongly hindered by the quasifission (QF) mechanism which prevents the formation of an equilibrated compound nucleus and which depends on the structure of the reactants. New SHEs have been recently produced with doubly-magic 48Ca beams. However, SHE synthesis experiments with single-magic 50Ti beams have so far been unsuccessful. Purpose: In connection with experimental searches for Z =117 ,119 superheavy elements, we perform a theoretical study of fusion and quasifission mechanisms in 48Ca,50Ti+249Bk reactions in order to investigate possible differences in reaction mechanisms induced by these two projectiles. Methods: The collision dynamics and the outcome of the reactions are studied using unrestricted time-dependent Hartree-Fock (TDHF) calculations as well as the density-constrained TDHF method to extract the nucleus-nucleus potentials and the excitation energy in each fragment. Results: Nucleus-nucleus potentials, nuclear contact times, masses and charges of the fragments, as well as their kinetic and excitation energies strongly depend on the orientation of the prolate 249Bk nucleus. Long contact times associated with fusion are observed in collisions of both projectiles with the side of the 249Bk nucleus, but not on collisions with its tip. The energy and impact parameter dependencies of the fragment properties, as well as their mass-angle and mass-total kinetic energy correlations are investigated. Conclusions: Entrance channel reaction dynamics are similar with both 48Ca and 50Ti projectiles. Both are expected to lead to the formation of a compound nucleus by fusion if they have enough energy to get in contact with the side of the 249Bk target.

  7. Investigation of constraints on few-neutron forces in neutron matter by empirical information on the neutron skin of 48Ca and 208Pb

    NASA Astrophysics Data System (ADS)

    Sammarruca, Francesca

    2016-11-01

    The neutron matter equation of state is calculated from two-neutron forces up to fifth order of the chiral expansion, and the order-by-order convergence of the predictions is investigated. Based on these equations of state, the binding energies and the neutron and proton density distributions in 208Pb and 48Ca are derived, with particular attention paid to the neutron skins, the focal point of this paper. Anticipating future experiments which will provide reliable information on the weak charge density in nuclei, the theoretical uncertainties and the possibility of constraining the size of few-neutron forces in neutron matter are discussed.

  8. Intermediate Nuclear Structure for 2v 2{beta} Decay of {sup 48}Ca Studied by (p, n) and (n, p) Reactions at 300 MeV

    SciTech Connect

    Sakai, H.; Yako, K.

    2009-08-26

    Angular distributions of the double differential cross sections for the {sup 48}Ca(p,n) and the {sup 48}Ti(n,p) reactions were measured at 300 MeV. A multipole decomposition technique was applied to the spectra to extract the Gamow-Teller (GT) transition strengths. In the (n, p) spectrum beyond 8 MeV excitation energy extra B(GT{sup +}) strengths which are not predicted by the shell model calculation. This extra B(GT{sup +}) strengths significantly contribute to the nuclear matrix element of the 2v2{beta}-decay.

  9. Long-term {alpha}- and spontaneous fission measurement of a Rf/Db sample chemically prepared in a {sup 48}Ca on {sup 243}Am experiment

    SciTech Connect

    Dressler, Rugard; Eichler, Robert; Schumann, Dorothea; Shishkin, Sergey

    2009-05-15

    Results from long-term measurements of a chemically separated Db/Rf sample prepared from the products of a {sup 48}Ca on {sup 243}Am irradiation are presented. The sample with the highest spontaneous fission activity out of eight samples produced in the course of chemical experiments performed in 2004 was selected for these measurements. We conclude that there is no evidence for SF-decay originating from heavy actinide isotopes in this sample. Hence, it is appropriate to assign the SF-events observed in this experiment to decay products of {sup 288}115.

  10. Dynamical Dipole mode in the 40,48 Ca +152,144Sm fusion reactions at 11 MeV/nucleon

    NASA Astrophysics Data System (ADS)

    Parascandolo, C.; Pierroutsakou, D.; Alba, R.; Del Zoppo, A.; Maiolino, C.; Santonocito, D.; Agodi, C.; Baran, V.; Boiano, A.; Colonna, M.; Coniglione, R.; De Filippo, E.; Di Toro, M.; Emanuele, U.; Farinon, F.; Guglielmetti, A.; La Commara, M.; Martin, B.; Mazzocchi, C.; Mazzocco, M.; Rizzo, C.; Romoli, M.; Signorini, C.; Silvestri, R.; Soramel, F.; Strano, E.; Torresi, D.; Trifirò, A.; Trimarchi, M.

    2016-05-01

    The excitation of the dynamical dipole mode along the fusion path was investigated in the formation of a heavy compound nucleus in the A=190 mass region. To form the compound nucleus, the 40Ca + 152Sm and 48Ca + 144Sm reactions were employed at Elab=11 and 10.1 MeV/nucleon, respectively. Both fusion-evaporation and fission events were studied simultaneously for the first time. Our results for evaporation and fission events (preliminary) show that the dynamical dipole mode survives in reactions involving heavier nuclei than those studied previously.

  11. α and 3He production in the 7Be+28Si reaction at near-barrier energies: Direct versus compound-nucleus mechanisms

    NASA Astrophysics Data System (ADS)

    Sgouros, O.; Pakou, A.; Pierroutsakou, D.; Mazzocco, M.; Acosta, L.; Aslanoglou, X.; Betsou, Ch.; Boiano, A.; Boiano, C.; Carbone, D.; Cavallaro, M.; Grebosz, J.; Keeley, N.; La Commara, M.; Manea, C.; Marquinez-Duran, G.; Martel, I.; Nicolis, N. G.; Parascandolo, C.; Rusek, K.; Sánchez-Benítez, A. M.; Signorini, C.; Soramel, F.; Soukeras, V.; Stefanini, C.; Stiliaris, E.; Strano, E.; Strojek, I.; Torresi, D.

    2016-10-01

    The production of α and 3He particles, the cluster constituents of 7Be, in the 7Be+28Si reaction was studied at three near-barrier energies, namely 13, 20, and 22 MeV. Angular distribution measurements were performed at each energy, and the data were analyzed in both statistical model and Distorted-Wave Born Approximation (DWBA) frameworks in order to disentangle the degree of competition between direct and compound channels. The energy evolution of the ratio of direct to total reaction cross section was mapped in comparison with similar data for 6Li and 7Li projectiles on a 28Si target. The results indicate larger transfer contributions for collisions involving the mirror nuclei 7Be and 7Li than in the 6Li case. Fusion cross sections were deduced, taking into account the α -particle cross sections due to compound-nucleus formation and particle multiplicities deduced from our statistical model framework. It was found that fusion is compatible with systematics and single-barrier penetration cross sections to within an uncertainty band of 10% to 20%. Indications of fusion hindrance for 7Li and 7Be compared to 6Li, starting from the barrier and below it, are given. This hindrance is attributed to the existence of large transfer channels. Furthermore, the experimental results, analyzed in the DWBA framework, suggest 3He and 4He transfer as the dominant direct reaction mechanism.

  12. New Insights into the 243Am 48Ca Reaction Products Previously Observed in the Experiments on Elements 113, 115, and 117

    SciTech Connect

    Oganessian, Yuri Ts.; Abdullin, F. Sh.; Dmitriev, S.; Gostic, J. M.; Hamilton, Joseph; Henderson, R.; Itkis, M. G.; Moody, K.; Polyakov, A. N.; Ramayya, A. V.; Roberto, James B; Rykaczewski, Krzysztof Piotr; Sagaidak, R. N.; Shaughnessy, D.; Shirokovsky, I. V.; Stoyer, M.; Subbotin, V. G.; Sukhov, A. M.; Tsyganov, Yu. S.; Utyonkov, V.; Voinov, A. A.; Vostokin, G. K.

    2012-01-01

    Results of a new series of experiments on the study of production cross sections and decay properties of the isotopes of element 115 in the reaction {sup 243}Am + {sup 48}Ca are presented. Twenty-one new decay chains originating from {sup 288}115 were established as the product of the 3n-evaporation channel by measuring the excitation function at three excitation energies of the compound nucleus {sup 291}115. The decay properties of all newly observed nuclei are in full agreement with those we measured in 2003. At the lowest excitation energy E* = 33 MeV, for the first time we registered the product of the 2n-evaporation channel, {sup 289}115, which was also observed previously in the reaction {sup 249}Bk + {sup 48}Ca as the daughter nucleus of the decay of {sup 293}117. The maximum cross section for the production of {sup 288}115 is found to be 8.5 pb at E* {approx} 36 MeV.

  13. New insights into the 243Am + 48Ca reaction products previously observed in the experiments on elements 113, 115, and 117.

    PubMed

    Oganessian, Yu Ts; Abdullin, F Sh; Dmitriev, S N; Gostic, J M; Hamilton, J H; Henderson, R A; Itkis, M G; Moody, K J; Polyakov, A N; Ramayya, A V; Roberto, J B; Rykaczewski, K P; Sagaidak, R N; Shaughnessy, D A; Shirokovsky, I V; Stoyer, M A; Subbotin, V G; Sukhov, A M; Tsyganov, Yu S; Utyonkov, V K; Voinov, A A; Vostokin, G K

    2012-01-13

    Results of a new series of experiments on the study of production cross sections and decay properties of the isotopes of element 115 in the reaction (243)Am+(48)Ca are presented. Twenty-one new decay chains originating from (288)115 were established as the product of the 3n-evaporation channel by measuring the excitation function at three excitation energies of the compound nucleus (291)115. The decay properties of all newly observed nuclei are in full agreement with those we measured in 2003. At the lowest excitation energy E*=33 MeV, for the first time we registered the product of the 2n-evaporation channel, (289)115, which was also observed previously in the reaction (249)Bk+(48)Ca as the daughter nucleus of the decay of (293)117. The maximum cross section for the production of (288)115 is found to be 8.5 pb at E*≈36 MeV.

  14. Information und Kommunikation

    NASA Astrophysics Data System (ADS)

    Wesoly, Michael; Ohlhausen, Peter; Bucher, Michael; Hichert, Rolf; Korge, Gabriele; Schnabel, Ulrich; Gairola, Arun; Reichwald, Ralf; Habicht, Hagen; Möslein, Kathrin; Schwarz, Torsten; Schönsleben, Paul; Scherer, Eric; Schloske, Alexander; Adlbrecht, Gerald; Federhen, Jens

    Wissen ist mittlerweile unverzichtbar für den entscheidenden Vorsprung auf dem Markt. Unabhängig davon, ob sich das Wissen in Innovationen, neuen Produkten und Dienstleistungen oder in der Verbesserung interner Unternehmensprozesse manifestiert: Wissen ist Treiber von Innovation, Wissen bringt Schnelligkeit und Wissen ist die Voraussetzung für Problemlösungen [40]. Wissensmanagement ist daher der Schlüssel für Unternehmenserfolg und bezeichnet den "bewussten und systematischen Umgang mit der Ressource Wissen und den zielgerichteten Einsatz von Wissen in der Organisation“ [6]. In dieser umfassenden Sichtweise ist Wissensmanagement ein Begriff, der Konzepte, Strategien und Methoden umfasst.

  15. Ingenieurgeologie: Grundlagen und Anwendung

    NASA Astrophysics Data System (ADS)

    Genske, Dieter D.

    Geplünderter Planet? Die Ingenieurgeologie ist ein junges, interdisziplinäres Fachgebiet. Es befasst sich mit der Wechselwirkung zwischen Geosphäre und Mensch. Der Autor stellt Georisiken vor und diskutiert die Folgen menschlicher Eingriffe in die Natur. Er thematisiert aktuelle Herausforderungen und entwirft nachhaltige Lösungskonzepte für verschiedene Problembereiche: z.B. Naturgefahren wie Hangrutschungen und Bergfälle, die Ausbeute natürlicher Ressourcen, Bau- und Sanierungsvorhaben. Fallbeschreibungen und ausgearbeitete Beispiele vertiefen das Verständnis für diesen neuen, zukunftsweisenden Zweig der Wissenschaft.

  16. Lymph- und Immunsystem

    NASA Astrophysics Data System (ADS)

    Perry, Steven F.

    Alle Lebewesen müssen sich gegen Eindringlinge wehren. Ihre Abwehrmechanismen wirken auf verschiedenen Ebenen, von übergeordneten Feindvermeidungsstrategien und Putzverhalten bis hin zu molekularen Erkennungs- und Tötungsmechanismen. Da Eindringlinge über Kontaktflächen mit der Außenwelt, wie z.B. Körperoberfläche, Darmwand und Atmungsoberflächen, in den Organismus gelangen, sind an diesen Stellen immer primäre Abwehrmechanismen zu finden. Dazu zählen (1) Schleimabsonderung (Schleimhäute bei allen Schädeltieren, Fischkiemen, epidermale Schleimdrüsen (Fische, Amphibien)), (2) Stoffwechselgifte und antibakteriell wirkende Substanzen in der Haut (Fische, Amphibien) und im Speichel (Amnioten), (3) Flimmerepithelien zum Abtransport von Eindringlingen und (4) starke Keratinbildung in der mehrschichtigen Epidermis und schützende Strukturen wie Schuppen, Federn und Haare (Amnioten) (S. 20). Auch die starke Säurebildung im Magen kann als Schutz gegen Eindringlinge betrachtet werden.

  17. Valley spin-orbit interaction for the triplet and doublet 1sground states of lithium donor center in monoisotopic {sup 28}Si

    SciTech Connect

    Ezhevskii, Alexander A.; Popkov, Sergey A.; Soukhorukov, Andrey V.; Guseinov, Davud V.; Konakov, Anton A.; Abrosimov, Nikolai V.; Riemann, Helge

    2013-12-04

    Valley spin-orbit interaction for the triplet and doublet 1s-ground states of lithium donor center in monoisotopic {sup 28}Si was studied in order to determine its contribution to the electron spin relaxation rate. We observed new electron paramagnetic resonance spectra of lithium in monoisotopic silicon with g<2.000 and found the spin Hamiltonian parameters for it. Using our experimental results and taking into account spin-orbit coupling between the triplet states and the triplet and doublet states we found that the lithium donor electron spectrum and g-factors for its states strongly depend on both the internal strains in the crystal and the intervalley spin-orbit interactions.

  18. Fission fragment angular distributions in the reactions {sup 16}O+{sup 188}Os and {sup 28}Si+{sup 176}Yb

    SciTech Connect

    Tripathi, R.; Sudarshan, K.; Sharma, S. K.; Reddy, A. V. R.; Pujari, P. K.; Goswami, A.; Ramachandran, K.

    2009-06-15

    Fission fragment angular distributions have been measured in the reactions {sup 16}O+{sup 188}Os and {sup 28}Si+{sup 176}Yb to investigate the contribution from noncompound nucleus fission. Parameters for statistical model calculations were fixed using fission cross section data in the {sup 16}O+{sup 188}Os reaction. Experimental anisotropies were in reasonable agreement with those calculated using the statistical saddle point model for both reactions. The present results are also consistent with those of mass distribution studies in the fission of {sup 202}Po, formed in the reactions with varying entrance channel mass asymmetry. However, the present studies do not show a large fusion hindrance as reported in the pre-actinide region based on the measurement of evaporation residue cross section.

  19. MULTIFRACTAL ANALYSIS OF CHARGED PARTICLE DISTRIBUTION IN 28Si-Ag/Br INTERACTION AT 14.5A GeV

    NASA Astrophysics Data System (ADS)

    Mali, P.; Mukhopadhyay, A.; Singh, G.

    2012-04-01

    The multifractal structure of one dimensional charged particle density distribution in 28Si-Ag/Br interactions at 14.5 GeV per nucleon is investigated by using two different techniques. The experimental measurements are compared with a microscopic transport model of particle production based on the Ultra-relativistic Quantum Molecular Dynamics (UrQMD). Various parameters related to multifractality, for example the Lévy's index, are obtained. Our analysis shows that multifractal structure is present both in the experiment as well as in the simulation. As far as the self-similar nature of the density fluctuation is concerned, there exists, however, a small but definite quantitative difference between the two.

  20. In-beam γ-ray Spectroscopy of {sup 30}P via the {sup 28}Si({sup 3}He,pγ){sup 30}P Reaction

    SciTech Connect

    Mcneice, E.; Setoodehnia, K.; Singh, B.; Abe, Y.; Binh, D.N.; Chen, A.A.; Chen, J.; Cherubini, S.; Fukuoka, S.; Hashimoto, T.; Hayakawa, T.; Ishibashi, Y.; Ito, Y.; Kahl, D.; Komatsubara, T.; Kubono, S.; Moriguchi, T.; Nagae, D.; Nishikiori, R.; Niwa, T.; and others

    2014-06-15

    The level structure of {sup 30}P up to 8.25 MeV was investigated via in-beam γ-ray spectroscopy using the {sup 28}Si({sup 3}He,pγ){sup 30}P reaction at 9 MeV at the University of Tsukuba Tandem Accelerator Complex in Japan. An energy level scheme was deduced from γ-γ coincidence measurements. 47 new transitions have been observed from the previously known states (mostly resonances), thereby reducing the uncertainties in the excitation energies of 17 states from 3 to 10 keV to values of < 1 keV. Furthermore, spin assignments based on measurements of γ-ray angular distributions and γ-γ directional correlation of oriented nuclei (DCO ratios) were made for several observed levels of {sup 30}P.

  1. 18O/16O, 30Si/28Si, D/H, and 13C/12C Studies of Lunar Rocks and Minerals.

    PubMed

    Epstein, S; Taylor, H P

    1970-01-30

    The delta (18)O of minerals from lunar gabbros and basalts are: plgioclases +6.06 to +6.33), pyroxenes (+5.70 to +5.95), and ilmenites (+3.85 to +4.12). The uniformity of these results indicates isotopic equilibrium in the mineral assemblages. Estimated plagioclase-ilmenite temperautres range from 1150 degrees C to 1340 degrees C. The bulk (18)/ (16)O and (30)Si/ (28)Si ratios of these lunar rocks are identical with ratios of terrestrial basalts, but the lunar glass, breccia, and dust are slightly enriched in the heavier isotopes. The lunar hydrogen (formed from solar wind) has a delta D/H of less than-873 per mil and the value may be even lower, as it is probably contaminated with terrestrial hydrogen. The delta (13)C of lunar dust and breccia is unusually high relative to reduced carbon in meteorites or on earth.

  2. Decay of the excited compound system 48Cr* formed through 24Mg + 24Mg , 36Ar + 12C and 20Ne + 28Si reactions

    NASA Astrophysics Data System (ADS)

    Santhosh, K. P.; Subha, P. V.; Priyanka, B.

    2016-05-01

    The total cross section, the intermediate mass fragment (IMF) production cross section, and the cross section for the formation of light particle (LP) for the decay of 48Cr* formed through the entrance channel 24Mg + 24Mg , have been evaluated using the barrier penetration model, taking the scattering potential as the sum of the Coulomb and nuclear proximity potential, for various ECM values. The computed results have been compared with the available experimental data of the total cross section corresponding to E CM = 44.4 MeV for the entrance channel 24Mg + 24Mg , and were found to be in good agreement. The experimental values for the LP production cross section for the channel 24Mg + 24Mg were also seen to be agreeing with our calculations. Hence we have extended our studies and have thus computed the total cross section, IMF cross section and LP cross section for the decay of 48Cr* formed through the other two entrance channels 36Ar + 12C , and 20Ne + 28Si with different ECM values. It was found that the computed total cross sections for the entrance channel 36Ar + 12C with E CM = 47 MeV agree well with the corresponding experimental values. Hence, we hope that our predictions on the evaluations of the IMF cross sections and the light charged particle cross sections for the decay of 48Cr* , formed through the two entrance channels 36Ar + 12C , and 20Ne + 28Si , can be used for further experimental studies.

  3. Eleven new heaviest isotopes of elements Z=105 to Z=117 identified among the products of {sup 249}Bk+{sup 48}Ca reactions

    SciTech Connect

    Oganessian, Yu. Ts.; Abdullin, F. Sh.; Dmitriev, S. N.; Itkis, M. G.; Lobanov, Yu. V.; Mezentsev, A. N.; Polyakov, A. N.; Sagaidak, R. N.; Shirokovsky, I. V.; Subbotin, V. G.; Sukhov, A. M.; Tsyganov, Yu. S.; Utyonkov, V. K.; Voinov, A. A.; Vostokin, G. K.; Bailey, P. D.; Benker, D. E.; Ezold, J. G.; Porter, C. E.; Riley, F. D.

    2011-05-15

    The heaviest isotopes of elements Z=117 to Z=105, {sup 294}117, {sup 293}117, {sup 290}115, {sup 289}115, {sup 286}113, {sup 285}113, {sup 282}Rg, {sup 281}Rg, {sup 278}Mt, {sup 274}Bh, and {sup 270}Db, were identified by means of the Dubna gas-filled recoil separator among the products of the {sup 249}Bk + {sup 48}Ca reaction. The details of the observed six decay chains, indicating the production and decay of isotopes {sup 293}117 and {sup 294}117, are presented and discussed. The decay energies and resulting half-lives of these new nuclei show a strong rise of stability with increasing neutron number, validating the concept of the island of enhanced stability for superheavy nuclei [Oganessian et al., Phys. Rev. Lett. 104, 142502 (2010)].

  4. Magnetic and magnetocaloric properties of polycrystalline La0.48Ca0.52MnO3 compound at low temperature: Influence of glassy magnetic state

    NASA Astrophysics Data System (ADS)

    Das, Kalipada; Das, I.

    2017-04-01

    We report the magnetic, magnetocaloric and electrical transport properties of polycrystalline bulk La0.48Ca0.52MnO3 compound. In addition to earlier reported properties viz. charge ordering and antiferromagnetic ordering, we address the presence of glassy magnetic phase at low temperature (T < 40 K) in this compound. Studies on magnetic and magnetocaloric properties reveal that, pronounced glassy behavior in this compound is due to presence of ferromagnetic clusters in the low-temperature region. In addition to that, analysis of low-temperature x-ray diffraction measurements indicate increasing crystallographic unit cell volume which is attributed to the enhancement of eg-electron bandwidth at low temperature.

  5. Isotope shift of 40,42,44,48Ca in the 4s 2S1/2 → 4p 2P3/2 transition

    NASA Astrophysics Data System (ADS)

    Gorges, C.; Blaum, K.; Frömmgen, N.; Geppert, Ch; Hammen, M.; Kaufmann, S.; Krämer, J.; Krieger, A.; Neugart, R.; Sánchez, R.; Nörtershäuser, W.

    2015-12-01

    We report on improved isotope shift measurements of the isotopes {}{40,42,{44,48}}Ca in the 4{{s}}{ }2{{{S}}}1/2\\to 4{{p}}{ }2{{{P}}}3/2 (D2) transition using collinear laser spectroscopy. Accurately known isotope shifts in the 4{{s}}{ }2{{{S}}}1/2\\to 4{{p}}{ }2{{{P}}}1/2(D1) transition were used to calibrate the ion beam energy with an uncertainty of {{Δ }}U≈ +/- 0.25 {{V}}. The accuracy in the D2 transition was improved by a factor of 5-10. A King-plot analysis of the two transitions revealed that the field shift factor in the D2 line is about 1.8(13)% larger than in the D1 transition which is ascribed to relativistic contributions of the 4{{{p}}}1/2 wave function.

  6. ({sup 3}He,t) reaction on the double {beta} decay nucleus {sup 48}Ca and the importance of nuclear matrix elements

    SciTech Connect

    Grewe, E.-W.; Frekers, D.; Rakers, S.; Baeumer, C.; Dohmann, H.; Thies, J.; Adachi, T.; Fujita, Y.; Shimbara, Y.; Botha, N. T.; Fujita, H.; Hatanaka, K.; Nakanishi, K.; Sakemi, Y.; Shimizu, Y.; Tameshige, Y.; Tamii, A.; Negret, A.; Popescu, L.; Neveling, R.

    2007-11-15

    High-resolution ({sup 3}He,t) measurements on the double {beta}-decay ({beta}{beta}) nucleus {sup 48}Ca have been performed at RCNP (Osaka, Japan) to determine Gamow-Teller (GT{sup -}) transitions to the nucleus {sup 48}Sc, which represents the intermediate nucleus in the second-order perturbative description of the {beta}{beta} decay. At a bombarding energy of E{sub {sup 3}He}=420 MeV an excitation energy resolution of 40 keV was achieved. The measurements were performed at two angle positions of the Grand Raiden Spectrometer (GRS): 0 deg. and 2.5 deg. The results of both settings were combined to achieve angular distributions, by which the character of single transitions could be determined. To characterize the different multipoles, theoretical angular distributions for states with J{sup {pi}}=1{sup +},2{sup +},2{sup -}, and 3{sup +} were calculated using the distorted-wave Born approximation (DWBA) Code DW81. The GT{sup -} strength was extracted up to E{sub x}=7 MeV and combined with corresponding GT{sup +} strength deduced from the {sup 48}Ti(d,{sup 2}He){sup 48}Sc data to calculate the low-energy part of the {beta}{beta}-decay matrix element for the {sup 48}Ca 2{nu}{beta}{beta} decay. We show that after applying trivial momentum corrections to the ({sup 3}He,t) spectrum, the two reaction probes (p,n) and ({sup 3}He,t) reveal a spectral response to an impressively high degree of similarity in the region of low momentum transfer.

  7. Production of A=16, 20 and 24 in alpha-induced fragmentation of ^28Si at 102.7 (cm) MeV

    NASA Astrophysics Data System (ADS)

    Sabra, Mohammad S.; Bary Malik, F.

    2004-10-01

    The emission probabilities of particles of mass numbers 16, 20 and 24 in 102.7 (cm) MeV alpha-induced fragmentation of ^28Si have been calculated using the statistical model of [1]. This model is distinct from the usual evaporation model in the sense that it takes into account the final state interaction between two emerging fragments. Calculated emission probabilities indicate that particles are emitted in all possible excited states commensurate with energy conservation law. The emission spectra as a function of excitation energy and the most probable kinetic energy associated with it will be presented. Calculated differential cross sections at 30^o for these masses are in agreement with the data of [2]. The final state interaction is obtained by a scaling procedure. The emission probabilities of different isotopes of these masses will also be presented. 1. B. Compani-Tabrizi and F. B. Malik, J. Phys. G: Nucl. Phys. 8, 1447 (1982). 2. L. W. Woo et al. Phys. Rev. C 47, 267 (1993).

  8. High-precision {sup 28}Si(p,t){sup 26}Si reaction to determine {sup 22}Mg({alpha},p){sup 25}Al reaction rates

    SciTech Connect

    Matic, A.; Berg, A. M. van den; Harakeh, M. N.; Woertche, H. J.; Beard, M.; Berg, G. P. A.; Goerres, J.; LeBlanc, P.; O'Brien, S.; Wiescher, M.; Fujita, K.; Hatanaka, K.; Sakemi, Y.; Shimizu, Y.; Tameshige, Y.; Tamii, A.; Yosoi, M.; Adachi, T.; Fujita, Y.; Shimbara, Y.

    2011-08-15

    The rise time of stellar x-ray bursts is a signature of thermonuclear runaway processes in the atmosphere of neutron stars and is highly sensitive to a series of ({alpha},p) reactions via high-lying resonances in sd-shell nuclei. Lacking data for the relevant resonance levels, the stellar reaction rates have been calculated using statistical, Hauser-Feshbach models, assuming a high-level density. This assumption may not be correct in view of the selectivity of the ({alpha},p) reaction to natural parity states. We measured the {sup 28}Si(p,t){sup 26}Si reaction with a high-resolution spectrometer to identify resonance levels in {sup 26}Si above the {alpha}-emission threshold at 9.164 MeV excitation energy. These resonance levels are used to calculate the stellar reaction rate of the {sup 22}Mg({alpha},p){sup 25}Al reaction and to test the validity of the statistical assumption.

  9. Zwergsatelliten und Sternriesen

    NASA Astrophysics Data System (ADS)

    Baade, Dietrich; Kuschnig, Rainer

    2017-03-01

    Leuchtkräftige Sterne sind schwierig: Fär Fotometrie mit großen Teleskopen sind sie zu hell, und ihre geringe Zahl macht konventionelle Lösungen unwirtschaftlich, besonders im Weltraum, wo die äußerste Präzision gegeben wäre. Mit einer Mini-Armada von Nanosatelliten haben Ingenieure und Astronomen aus Kanada, Österreich und Polen nun die Lösung gefunden - auch schon für viele wissenschaftliche Fragen.

  10. Giant enhancement of magnetocaloric effect at room temperature by the formation of nanoparticle of La0.48Ca0.52MnO3 compound

    NASA Astrophysics Data System (ADS)

    Das, Kalipada; Das, I.

    2016-03-01

    Magnetocaloric effect (MCE) is the change in temperature or entropy of a material due to the application of external magnetic field. The temperature dependence of MCE shows maximum value near the ferromagnetic transition of the material. Material with large MCE near room temperature will make revolutionary change in cooling technology and will have large impact in human society. We have transformed antiferromagnetic bulk manganite material La0.48Ca0.52MnO3 to ferromagnetic material by the reduction of the particle size in nanometer scale. MCE, as well as the Relative cooling power (RCP) of the material at room temperature (RT) systematically increase with the reduction of the particle sizes. The RCP value for the 45 nm particle size sample at RT is about 400% larger compared with the bulk counterpart. Our detail study on the nano form of the compound highlights an effective way to enhance the MCE. It opens up a vast possibility of achieving giant enhancement of MCE of several already known materials just by the reduction of the particle size in nanometer scale.

  11. 48Ca+249Bk fusion reaction leading to element Z = 117: long-lived α-decaying 270Db and discovery of 266Lr.

    PubMed

    Khuyagbaatar, J; Yakushev, A; Düllmann, Ch E; Ackermann, D; Andersson, L-L; Asai, M; Block, M; Boll, R A; Brand, H; Cox, D M; Dasgupta, M; Derkx, X; Di Nitto, A; Eberhardt, K; Even, J; Evers, M; Fahlander, C; Forsberg, U; Gates, J M; Gharibyan, N; Golubev, P; Gregorich, K E; Hamilton, J H; Hartmann, W; Herzberg, R-D; Heßberger, F P; Hinde, D J; Hoffmann, J; Hollinger, R; Hübner, A; Jäger, E; Kindler, B; Kratz, J V; Krier, J; Kurz, N; Laatiaoui, M; Lahiri, S; Lang, R; Lommel, B; Maiti, M; Miernik, K; Minami, S; Mistry, A; Mokry, C; Nitsche, H; Omtvedt, J P; Pang, G K; Papadakis, P; Renisch, D; Roberto, J; Rudolph, D; Runke, J; Rykaczewski, K P; Sarmiento, L G; Schädel, M; Schausten, B; Semchenkov, A; Shaughnessy, D A; Steinegger, P; Steiner, J; Tereshatov, E E; Thörle-Pospiech, P; Tinschert, K; Torres De Heidenreich, T; Trautmann, N; Türler, A; Uusitalo, J; Ward, D E; Wegrzecki, M; Wiehl, N; Van Cleve, S M; Yakusheva, V

    2014-05-02

    The superheavy element with atomic number Z=117 was produced as an evaporation residue in the (48)Ca+(249)Bk fusion reaction at the gas-filled recoil separator TASCA at GSI Darmstadt, Germany. The radioactive decay of evaporation residues and their α-decay products was studied using a detection setup that allowed measuring decays of single atomic nuclei with half-lives between sub-μs and a few days. Two decay chains comprising seven α decays and a spontaneous fission each were identified and are assigned to the isotope (294)117 and its decay products. A hitherto unknown α-decay branch in (270)Db (Z = 105) was observed, which populated the new isotope (266)Lr (Z = 103). The identification of the long-lived (T(1/2) = 1.0(-0.4)(+1.9) h) α-emitter (270)Db marks an important step towards the observation of even more long-lived nuclei of superheavy elements located on an "island of stability."

  12. Isospin influence on the decay modes of compound systems produced in the 78,86Kr + 40,48Ca at 10 AMeV

    NASA Astrophysics Data System (ADS)

    Pirrone, S.; Politi, G.; Wieleczko, J. P.; De Filippo, E.; Gnoffo, B.; Russotto, P.; Trimarchi, M.; La Commara, M.; Vigilante, M.; Ademard, G.; Amorini, F.; Auditore, L.; Beck, C.; Berceanu, I.; Bonnet, E.; Borderie, B.; Cardella, G.; Chibihi, A.; Colonna, M.; D'Onofrio, A.; Frankland, J. D.; Geraci, E.; Henry, E.; La Guidara, E.; Lanzalone, G.; Lautesse, P.; Lebhertz, D.; Le Neindre, N.; Lombardo, I.; Mazurek, K.; Norella, S.; Pagano, A.; Pagano, E. V.; Papa, M.; Piasecki, E.; Porto, F.; Quattrocchi, L.; Quinlann, M.; Rizzo, F.; Schroeder, W. U.; Spadaccini, G.; Trifirò, A.; Toke, J.; Verde, G.

    2016-06-01

    The study of the decay modes competition of the compound systems produced in the collisions 78Kr+40Ca and 86Kr+48Ca at 10AMeV is presented. In particular, the N/Z entrance channel influence on the decay paths of the compound systems, directly connected to the isospin influence, is investigated. The experiment was performed at the INFN Laboratori Nazionali del Sud (LNS) in Catania by using the 4π multi-detector CHIMERA. Charge, mass, angular distributions and kinematical features of the reaction products were studied. The analysis shows some differences in the contribution arising from the various reaction mechanisms for the neutron poor and neutron rich systems. Comparison with theoretical statistical and dynamical models are presented for the two systems. Besides a study of the influence of the energy on the entrance channel is performed for the 78Kr+40Ca reaction, by comparing the results of this experiment to those obtained for the same system at 5.5 AMeV with the INDRA device at GANIL.

  13. Isospin influence on the decay modes of the systems produced in the 78,86Kr +40,48Ca reactions at 10 AMeV

    NASA Astrophysics Data System (ADS)

    Gnoffo, B.; Pirrone, S.; Politi, G.; La Commara, M.; Wieleczko, J. P.; De Filippo, E.; Russotto, P.; Trimarchi, M.; Vigilante, M.; Ademard, G.; Amorini, F.; Auditore, L.; Beck, C.; Bercenau, I.; Bonnet, E.; Borderie, B.; Cardella, G.; Chibihi, A.; Colonna, M.; D'Onofrio, A.; Frankland, J. D.; Geraci, E.; Henry, E.; La Guidara, E.; Lanzalone, G.; Lautesse, P.; Lebhertz, D.; LeNeidre, N.; Lombardo, I.; Mazurek, K.; Norella, S.; Pagano, A.; Pagano, E. V.; Papa, M.; Piasecki, E.; Porto, F.; Quattrocchi, L.; Quinlann, M.; Rizzo, F.; Shoroeder, U.; Spadaccini, G.; Trifirò, A.; Toke, J.; Verde, G.

    2016-05-01

    The results of the analysis of the reactions 78,86Kr +40,48 Ca at 10 AMeV are presented. The experiment was performed at the INFN Laboratori Nazionali del Sud (LNS) in Catania by using the 4π multidetector CHIMERA, with beams delivered by the Superconductive Cyclotron. The competition among the various disintegration paths and in particular the isospin effects on the decay modes of the produced composite systems are investigated; this provides information about fundamental nuclear quantities such as level density, fission barrier and viscosity. Different isotopic composition and relative richness are observed among the reaction products of the two systems. An odd-even staggering effect is present in the charge distributions, in particular for the light fragments produced by the neutron-poor system. The kinematical characteristics of the IMF seem to indicate a high degree of the relaxation of the formed system. Besides, global features analysis seems to show some differences in the contribution arising from the various reaction mechanisms for the two reactions.

  14. Determination of molecular stopping cross section of 12C, 16O, 28Si, 35Cl, 58Ni, 79Br, and 127I in silicon nitride

    NASA Astrophysics Data System (ADS)

    Barradas, N. P.; Bergmaier, A.; Mizohata, K.; Msimanga, M.; Räisänen, J.; Sajavaara, T.; Simon, A.

    2015-10-01

    Silicon nitride is a technologically important material in a range of applications due to a combination of important properties. Ion beam analysis techniques, and in particular, heavy ion elastic recoil detection analysis can be used to determine the stoichiometry of silicon nitride films, which often deviates from the ideal Si3N4, as well as the content of impurities such as hydrogen, even in the presence of other materials or in a matrix containing heavier elements. Accurate quantification of IBA results depends on the basic data used in the data analysis. Quantitative depth profiling relies on the knowledge of the stopping power cross sections of the materials studied for the ions involved, which in the case of HI-ERDA is both the primary beam, and the recoiled species. We measured the stopping cross section of 12C, 16O, 28Si, 35Cl, 58Ni, 79Br, and 127I in a well-characterised silicon nitride membrane. The measurements were made by independent groups utilising different experimental setups and methods. In some cases there is extensive overlap of the energy range in different experiments, allowing a comparison of the different results. The four independent data sets reported in this work are in excellent agreement with each other, in the cases where similar energy ranges were measured. On the other hand, the data are in most cases higher than calculations made with the interpolative schemes SRIM and MSTAR together with the Bragg rule. Better agreement is found with MSTAR in some of the cases studied. This work is a significant extension of the heavy ion stopping power data base for silicon nitride.

  15. Six Years of Short-Spaced Monitoring of the v=1 and v=2 J=1-0 (28)SiO Maser Emission in Evolved Stars

    NASA Technical Reports Server (NTRS)

    Alcolea, J.; Pardo, J. R.; Bujarrabal, V.; Bachiller, R.; Barcia, A.; Colomer, F.; Gallego, J. D.; Gomez-Gonzalez, J.; delPino, A.; Planesas, P.

    1999-01-01

    We present the results from a monitoring of the v=1 and v=2 J=1-0 (28)SiO maser emission in 21 objects, covering all types of known SiO maser emitters: 13 Mira variables, 2 long period semiregulars (SRGs), 3 variable supergiants (SGs), 2 OH/IR stars, and one young stellar object. This study has been carried out with the 13.7 meter radiotelescope of the Centro Astronomico de Yebes (Guadalajara, Spain), from July 1984 to May 1990, and represents the longest and most tightly sampled monitoring of SiO masers ever published. Our data show that for Mira-type (i.e. regular) variables, the SiO and optical light curves agree in period, and that the maxima of the SiO emission lag the optical ones by about 0.1-0.2 periods. Since a similar lag characterizes the near infrared (NIR) emission variability from these stars, we conclude that for regular variables SiO and NIR vary in phase. This result was confirmed in three objects for which NIR variability curves are available. For SRGs and SGs, we found a less systematic behavior, but when the SiO emission is periodic, its variability curve agrees with the optical one, also showing a lag between maximum epochs similar to that of Mira-type stars. The data clearly reveal other interesting details on the SiO maser variability, such as the strong intensity differences between different maxima and changes in the velocity distribution of the emission. Finally, the SiO masers associated to the young stellar object Orion IRc2 showed a double peaked spectrum with low amplitude, aperiodic variations.

  16. Neuausrichtung und Konsolidierung

    NASA Astrophysics Data System (ADS)

    Grohmann, Heinz

    Mit der Wahl von Wolfgang Wetzel zum Vorsitzenden der Deutschen Statistischen Gesellschaft im Jahre 1972 begann eine 32jährige Ära, in der die praktische und die theoretische Statistik in einem ausgewogenen Verhältnis gepflegt wurden. Ein regelmäßiger vierjähriger Wechsel im Vorsitz stärkte die Gemeinschaft und die praktische wie die wissenschaftliche Arbeit gleichermaßen. Die jährlichen Hauptversammlungen behandelten gesellschaftlich aktuelle wie zukunftsorientierte Themen, und die Ausschüsse sowie weitere Veranstaltungen gaben Gelegenheit zur Förderung und Pflege einer Vielzahl von Arbeitsgebieten der Statistik. Darüber wird nicht nur in diesem Kapitel, sondern auch in den Teilen II und III des Bandes berichtet.

  17. Tensoren und Felder

    NASA Astrophysics Data System (ADS)

    Dirschmid, Hans J.

    Das Lehrbuch soll Studierende mit Grundkenntnissen der Differential- und Integralrechnung in die klassische Feldtheorie mit modernen mathematischen Methoden einführen. Dementsprechend ist die Tensoranalysis das mathematische Thema, das Prinzip der Relativität das physikalische. Aus didaktischen Erwägungen gliedert sich der Text in zwei Teile. Um den Leser mit den Objekten vertraut zu machen, wird zunächst der affine und euklidische Raum zugrundegelegt, um verallgemeinernd zur Geometrie auf Mannigfaltigkeiten und Riemannschen Räumen überleiten zu können. Im Anschluß an die mathematische Theorie wird in die spezielle und allgemeine Relativitätstheorie eingeführt, wobei die Geometrie der Raum-Zeit, die Grundgesetze der Elektrodynamik und der Gravitation sowie Folgerungen zur Sprache kommen.

  18. Falten und fliegen: Papierflieger und ihre Physik

    NASA Astrophysics Data System (ADS)

    Gruber, Werner

    2004-09-01

    Mit Papierfliegern können wichtige Eigenschaften der Aerodynamik anschaulich vermittelt werden: ein Blatt Papier, ein paar Faltungen und schon kann man experimentieren. Allerdings sind beim Trimmen des Fliegers einige Punkte zu beachten. Besonders wichtig ist die Y-Stellung der Flügel, die ihm Flugstabilität verleiht. Ist der Flieger fertig, dann gilt es, die dem Modell am besten angepasste Wurftechnik herauszufinden. Dazu variiert man Wurfgeschwindigkeit und Abwurfwinkel. Den Boden kann ein Papierflieger auf vier prinzipiell verschiedenen Flugkurven erreichen: Optimal ist die Gerade, dann fliegt er am weitesten.

  19. First superheavy element experiments at the GSI recoil separator TASCA: The production and decay of element 114 in the {sup 244}Pu({sup 48}Ca,3-4n) reaction

    SciTech Connect

    Gates, J. M.; Duellmann, Ch. E.; Schaedel, M.; Ackermann, D.; Block, M.; Bruechle, W.; Essel, H. G.; Hartmann, W.; Hessberger, F. P.; Huebner, A.; Jaeger, E.; Khuyagbaatar, J.; Kindler, B.; Krier, J.; Kurz, N.; Lommel, B.; Schaffner, H.; Schausten, B.; Schimpf, E.; Steiner, J.

    2011-05-15

    Experiments with the new recoil separator, Transactinide Separator and Chemistry Apparatus (TASCA), at the GSI were performed by using beams of {sup 48}Ca to irradiate targets of {sup 206-208}Pb, which led to the production of {sup 252-254}No isotopes. These studies allowed for evaluation of the performance of TASCA when coupled to a new detector and electronics system. By following these studies, the isotopes of element 114 ({sup 288-291}114) were produced in irradiations of {sup 244}Pu targets with {sup 48}Ca beams at compound nucleus excitation energies around 41.7 and 37.5 MeV, demonstrating TASCA's ability to perform experiments with picobarn-level cross sections. A total of 15 decay chains were observed and were assigned to the decay of {sup 288-291}114. A new {alpha}-decay branch in {sup 281}Ds was observed, leading to the new nucleus {sup 277}Hs.

  20. Messung und Analyse

    NASA Astrophysics Data System (ADS)

    Bathelt, Hartmut; Scheinhardt, Michael; Sell, Hendrik; Sottek, Roland; Guidati, Sandro; Helfer, Martin

    Für die Beurteilung von Akustik und Fahrkomfort eines Fahrzeugs gilt in der Fahrzeugentwicklung immer noch der alte Grundsatz: "Der Kunde fährt nicht am Prüfstand, sondern auf der Straße“. Daher werden Gesamtbeurteilungen des Entwicklungsstandes und Konkurrenzvergleiche (Benchmarking) nach wie vor auf der Straße durchgeführt, meist auf ausgewählten Fahrbahnen am Prüfgelände oder im Rahmen der regelmäßigen Winter- und Sommererprobungen unter extremen Witterungsverhältnissen.

  1. Getreide, Brot und Feine Backwaren

    NASA Astrophysics Data System (ADS)

    von Grabowski, Hans-Uwe; Rolfe, Birgit

    Getreide und Getreideerzeugnisse sind ebenso wie Brot und Feine Backwaren nach dem Lebensmittel- und Futtermittel-Gesetzbuch (LFGB) [1] Lebensmittel im Sinne des Artikels 2 der VO (EG) Nr. 178/2002 (BasisVO) (s. auch Kap. 1.6/2.4.1/3.2). Gesetzlich festgelegte Begriffsbestimmungen gibt es für diese Lebensmittel nicht. Man muss sich daher allgemeiner Verkehrsauffassungen bedienen, wie sie von der Deutschen Lebensmittelbuch-Kommission in Form von Leitsätzen erarbeitet und veröffentlicht wurden [2]. Der Gesundheitsschutz und der Schutz des Verbrauchers vor Täuschung sind in der Basis-VO und dem LFGB geregelt.

  2. Instandhaltung und Normung

    NASA Astrophysics Data System (ADS)

    Rosenkranz-Wuttig, Angela

    Das DIN Deutsches Institut für Normung e.V. ist ein eingetragener Verein mit Sitz in Berlin. Das DIN erarbeitet gemeinsam mit den Experten der interessierten Kreise Normen und Standards als Dienstleistung für Wirtschaft, Staat und Gesellschaft. Die Kenntnis entsprechender Normen, Standards oder Regeln, sowie deren richtiger Einsatz, ist unter den heutigen Marktbedingungen für jedes Unternehmen ein nicht zu unterschätzender wirtschaftlicher Faktor. Normen schaffen Effizienz bei Produktionsabläufen und sorgen durch eine gleichbleibende sowie vergleichbare Produktqualität für Vertrauen bei den Endverbrauchern. Darüber hinaus stehen Normen unter rechtlichen Aspekten für mehr Sicherheit - Hersteller erreichen bei Anwendung und Einhaltung von Normen ein hohes Maß an rechtlicher Absicherung. Das DIN vertritt die deutschen Interessen in den europäischen und weltweiten Normungsorganisationen, siehe Abb. 1. Zuständig für die elektrotechnische Normung in Deutschland sowie als deutscher Repräsentant in den übernationalen Gremien ist die DKE Deutsche Kommission Elektrotechnik Elektronik Informationstechnik im DIN und VDE.

  3. Datenintegration und Deduplizierung

    NASA Astrophysics Data System (ADS)

    Bleiholder, Jens; Schmid, Joachim

    In Unternehmen liegen viele Daten heutzutage immer seltener vollständig an einem einzigen physikalischen Ort vor, sondern sind weltweit verteilt. Dies liegt zum einen an der immer besser gewordenen Infrastruktur, die eine solche Verteilung auf einfache Art und Weise ermöglicht, und zum anderen an der Tatsache, dass viele Unternehmen weltweit tätig sind. So fallen Daten weltweit an, werden aber jeweils lokal - vor Ort - gespeichert. Daher müssen oft mehrere Datenquellen genutzt werden, um einen aktuellen, vollständigen und genauen Überblick über die vorhandenen Daten zu gewinnen. Datenintegration hilft, indem sie Daten aus mehreren Quellen zusammenführt und einheitlich darstellt. Diese integrierten Daten können genutzt werden, um sich einen Überblick über das Unternehmen zu verschaffen, z.B. wenn Unternehmen fusionieren und nur noch eine Kundendatenbank bestehen bleiben soll, oder wenn zu einem Kunden die Daten aus den verschiedenen Fachabteilungen zusammengeführt werden sollen. Anhand eines solchen Beispiels, der Integration von Kundendaten zu Kfz- und Lebensversicherungen erläutern wir im Folgenden einzelne Techniken.

  4. Statistik in Naturwissenschaft und Technik

    NASA Astrophysics Data System (ADS)

    Wilrich, Peter-Theodor

    Mit dem Aufschwung von Naturwissenschaft und Technik zu Beginn des 19. Jahrhunderts entstand die mathematische Statistik, angeregt aus der Geodäsie (wie die Methode der kleinsten Quadrate) und der Anthropologie (wie die statistische Analyse mehrdimensionaler Beobachtungen und ihrer stochastischen Abhängigkeiten). Im Gegensatz zu den Wirtschafts- und Sozialwissenschaften, in denen Daten vorwiegend aus Beobachtungsstudien gewonnen werden, stehen in den Naturwissenschaften Experimente im Vordergrund. Daher gehört die statistische Versuchsplanung zu den insbesondere in Naturwissenschaft und Technik angewendeten statistischen Methoden, aber auch die Extremwertstatistik und Lebensdaueranalysen sowie die Methoden der räumlichen Statistik (insbesondere in der Umweltforschung). Im 20. Jahrhundert wurden Stichprobenpläne und Regelkarten (Kontrollkarten) zur Prozessregelung als Hilfsmittel der statistischen Qualitätssicherung entwickelt. Diese Methodenbündel, mit denen sich der Ausschuss Statistik in Naturwissenschaft und Technik immer wieder befasst, werden im Folgenden vorgestellt.

  5. Target rapidity baryon distributions in {sup 28}Si + {sup 197}Au and {sup 197}Au + {sup 197}Au collisions at 14.6 and 11.7 A{center_dot}GeV/c

    SciTech Connect

    Sangster, T.C.; Costales, J.B.; Namboodiri, M.N.; E802 Collaboration

    1993-02-25

    Proton and deuteron kinetic energy spectra have been measured at target rapidities for both minimum bias and central collisions of 14.6 A{center_dot}GeV/c {sup 28}Si and 11.7 A{center_dot}GeV/c {sup 197}Au beams with a {sup 197}Au target. The spectra were measured from a low energy threshold of approximately E{sub kin}=35 MeV to well over 200 MeV for laboratory angles of 50{degree} to 130{degree} ({vert_bar}{eta}{vert_bar} {le}0.76). The acceptance-corrected spectra have been fit over a limited range of kinetic energies using a Boltzmann distribution. The integrated yields and the inverse slope parameters are presented as a function of centrality for the {sup 28}Si + {sup 197}Au reaction and as a function of trigger for the {sup 197}Au + {sup 197}Au reaction. These quantities are also compared with the proton spectra generated using both the ARC and RQMD codes.

  6. Tipps und Tricks

    NASA Astrophysics Data System (ADS)

    Häger, Wolfgang; Bauermeister, Dirk

    Hier wollen wir einige uns nützlich erscheinende Hinweise zur Arbeit mit dem Inventor geben. Dabei geht es vor allem darum, das Arbeiten mit dem Inventor zu vereinfachen. Die Beispiele stellen eine unvollständige Aufzählung dar und sollen dazu anregen, nach alternativen Vorgehensweisen zu suchen (hier sei noch einmal ausdrücklich auf das Internet verwiesen).

  7. Arbeitsgestaltung und Mitarbeiterqualifizierung

    NASA Astrophysics Data System (ADS)

    Weiss-Oberdorfer, Werner; Hörner, Barbara; Holm, Ruth; Pirner, Evelin

    Die Wertkette gliedert ein Unternehmen in strategisch relevante Tätigkeiten, um dadurch Kostenverhalten sowie vorhandene und potenzielle Differenzierungsquellen zu verstehen. Wenn ein Unternehmen diese strategisch wichtigen Aktivitäten billiger oder besser als seine Konkurrenten erledigt, verschafft es sich einen Wettbewerbsvorteil." Michael Porter, 1985

  8. Wirkstoffe, Medikamente und Mathematische Bildverarbeitung

    NASA Astrophysics Data System (ADS)

    Bauer, Günter J.; Lorenz, Dirk A.; Maaß, Peter; Preckel, Hartwig; Trede, Dennis

    Die Entwicklung neuer Medikamente ist langwierig und teuer. Der erste Schritt ist hierbei die Suche nach neuen Wirkstoffkandidaten, die für die Behandlung bislang schwer therapierbarer Krankheiten geeignet sind. Hierfür stehen der Pharma- und Biotechnologieindustrie riesige Substanzbibliotheken zur Verfügung. In diesen Bibliotheken werden die unterschiedlichsten Substanzen gesammelt, die entweder synthetisch hergestellt oder aus Pilzen, Bakterienkulturen und anderen Lebewesen gewonnen werden können.

  9. Evaporation residue cross-section in the decay of 254No* formed in 206Pb + 48Ca and its isotopic dependence using other Pb targets within the dynamical cluster-decay model

    NASA Astrophysics Data System (ADS)

    Niyti; Gupta, Raj K.; Hess, Peter Otto

    2015-06-01

    The dynamical cluster-decay model (DCM), with deformation and orientation effects included, is used to calculate the fusion evaporation residue cross-sections σxn for x = 1, 2, 3 and 4 neutrons emission in a fusion reaction 206Pb + 48Ca → 254No* at various 48Ca-beam energies Elab = 212.7- 242.5 MeV (equivalently, E* = 19.8- 43.9 MeV). Considering the higher multipole deformations up to hexadecapole deformation β4i and the sticking moment-of-inertia IS, the DCM with pocket formula for nuclear proximity potential is shown to give a good description of the measured individual light-particle (here neutrons) decay channels for configurations of "hot, compact" orientations θci, within one parameter fitting of the neck-length ΔR. A check on some of the variables involved in DCM shows that (i) spherical configurations give nearly the same result as above for deformed and oriented ones; (ii) the non-sticking moment-of-inertia INS gives unphysical results; and (iii) configurations of "cold, elongated" orientations do not fit the data at all. Furthermore, for the four different isotopes of 204,206,207,208Pb-based reactions, the dependence of, say, the 2n-emission yield σ2n on the isotopic composition of the compound nucleus is also studied within the DCM for "hot" fusion process. Of all the four Pb-isotopes and three excitation energies E* considered, at each E*, the ΔR is largest for compound system 256No*, followed by 255No*, 254No* and smallest for 252No*, which means to suggest that the neutrons emission occur earliest for 256No*, then for 255No*, 254No* and finally by 252No*, in complete agreement with experimental data according to which compound system 256No* has the highest cross-section and 252No* the lowest with 255No* and 254No* lying in between. This result is related to the double magicity of both the target (208Pb) and projectile (48Ca) nuclei, as well as to the experimentally known result of projectile with a larger number of neutrons (here the target

  10. Zusammenfassung und Ausblick

    NASA Astrophysics Data System (ADS)

    Knopp, Lothar; Wiegleb, Gerhard

    Mit dem vorliegenden Buch wird als Ergebnis eines durch die Deutsche BundesstiftungUmwelt (DBU) geförderten Forschungsprojektes an der Brandenburgischen Technischen Universität Cottbus eine erste Standardisierung der Vorgehensweise zur Erfassung, Risikoabschätzung und Bewertung eines Biodiversitätsschadens nach dem Umweltschadensgesetz (USchadG) vorgelegt. Damit kann eine erste Bewertung potentieller Schadenssituationen vorgenommen werden. Die Nutzung der hier erarbeiteten Vorgehensweise bietet sich daher für all diejenigen an, die mit der Frage einer möglichen Haftung für Biodiversitätsschäden nach dem USchadG konfrontiert sind, seien es die Unteren und Oberen Naturschutzbehörden der Länder, die Schadensversicherer, die potentiell Haftenden oder die Naturschutzverbände.

  11. Molecular structure in /sup 12/C + /sup 12/C, orbiting in /sup 12/C + /sup 28/Si, and first studies of the /sup 60/Ni + /sup 60/Ni interaction

    SciTech Connect

    Erb, K.A.; Ford, J.L.C. Jr.; Novotny, R.; Shapira, D.

    1981-01-01

    Some physical implications of a recently proposed classification scheme for the /sup 12/C + /sup 12/C Coulomb barrier resonances for which the requisite very large body of experimental data is already available are discussed. New data are presented suggesting that the back angle resonance-like structure previously observed in quasi-elastic /sup 28/Si + /sup 12/C reactions reflects the existence of a fully developed, rotating di-nuclear system that governs back-angle yields in many additional exit channels. Also some very recent data are briefly discussed for /sup 60/Ni + /sup 60/Ni scattering in a first look at a previously unstudied region of the periodic table. (WHK)

  12. Measurements of cross sections and decay properties of the isotopes of elements 112, 114, and 116 produced in the fusion reactions {sup 233,238}U, {sup 242}Pu, and {sup 248}Cm+{sup 48}Ca

    SciTech Connect

    Oganessian, Yu.Ts.; Utyonkov, V.K.; Lobanov, Yu.V.; Abdullin, F.Sh.; Polyakov, A.N.; Shirokovsky, I.V.; Tsyganov, Yu.S.; Gulbekian, G.G.; Bogomolov, S.L.; Gikal, B.N.; Mezentsev, A.N.; Iliev, S.; Subbotin, V.G.; Sukhov, A.M.; Voinov, A.A.; Buklanov, G.V.; Subotic, K.; Zagrebaev, V.I.; Itkis, M.G.; Patin, J.B.

    2004-12-01

    We have studied the dependence of the production cross sections of the isotopes {sup 282,283}112 and {sup 286,287}114 on the excitation energy of the compound nuclei {sup 286}112 and {sup 290}114. The maximum cross section values of the xn-evaporation channels for the reaction {sup 238}U({sup 48}Ca,xn){sup 286-x}112 were measured to be {sigma}{sub 3n}=2.5{sub -1.1}{sup +1.8} pb and {sigma}{sub 4n}=0.6{sub -0.5}{sup +1.6} pb; for the reaction {sup 242}Pu({sup 48}Ca,xn){sup 290-x}114: {sigma}{sub 2n}{approx}0.5 pb, {sigma}{sub 3n}=3.6{sub -1.7}{sup +3.4} pb, and {sigma}{sub 4n}=4.5{sub -1.9}{sup +3.6} pb. In the reaction {sup 233}U({sup 48}Ca,2-4n){sup 277-279}112 at E*=34.9=2.2 MeV we measured an upper cross section limit of {sigma}{sub xn}{<=}0.6 pb. The observed shift of the excitation energy associated with the maximum sum evaporation residue cross section {sigma}{sub ER}(E*) to values significantly higher than that associated with the calculated Coulomb barrier can be caused by the orientation of the deformed target nucleus in the entrance channel of the reaction. An increase of {sigma}{sub ER} in the reactions of actinide targets with {sup 48}Ca is consistent with the expected increase of the survivability of the excited compound nucleus upon closer approach to the closed neutron shell N=184. In the present work we detected 33 decay chains arising in the decay of the known nuclei {sup 282}112, {sup 283}112, {sup 286}114, {sup 287}114, and {sup 288}114. In the decay of {sup 287}114({alpha}){yields}{sup 283}112({alpha}){yields}{sup 279}110(SF), in two cases out of 22, we observed decay chains of four and five sequential {alpha} transitions that end in spontaneous fission of {sup 271}Sg (T{sub {alpha}}{sub /SF}=2.4{sub -1.0}{sup +4.3} min) and {sup 267}Rf (T{sub SF}{approx}2.3 h), longer decay chains than reported previously. We observed the new nuclide {sup 292}116 (T{sub {alpha}}=18{sub -6}{sup +16} ms,E{sub {alpha}}=10.66{+-}0.07 MeV) in the irradiation of the

  13. Pyropheophorbide und a as a catabolite of ethylene-induced chlorophyll und a degradation

    SciTech Connect

    Shimokawa, Keishi; Hashizume, Akihito ); Shioi, Yuzo )

    1990-05-01

    An enzyme extract prepared from ethylene-induced degreening Citrus fruits contains chlorophyll (Chl) degrading enzymes. The fate of Chl carbons during an enzymatic degradation was investigated using Chl {und a}-{sup 14}C. Accompanying the disappearance of labelled Chl {und a}, pheophorbide {und a} and pyropheophorbide {und a} appeared and accumulation of pyropheophorbide {und a} was observed. HydroxyChl {und a} was also detected, but this is thought to be an artifact during chromatography. Unlike ethylene-induced Citrus fruits (in vivo), further degradation of pyropheophorbide {und a} did not occur in vitro enzyme system. This suggests that there is a lack of enzyme(s) and/or cofactor(s) for further degradation. It is concluded that Chl {und a} degraded enzymatically by the following order: Chl {und a}, chlorophyllide {und a}, pheophorbide {und a} and pyropheophorbide {und a}.

  14. Organe der Osmoregulation und Exkretion

    NASA Astrophysics Data System (ADS)

    Møbjerg, Nadja

    Die meisten Schädeltiere sind in der Lage, die Wasser- und Ionenkonzentration ihres Innenmilieus zu regulieren, sind also im Hinblick auf ihren Ionenhaushalt weitgehend unabhängig von der Umgebung. Sie halten die Konzentration von Wasser und anorganischen Ionen in ihren Körperflüssigkeiten (interstitielle Flüssigkeit und Blut) innerhalb enger Grenzen konstant (Osmoregulierer). Schleim aale (Myxinoida) können zwar die Konzentration einzelner anorganischer Ionen regulieren, sind aber insgesamt der hohen Osmolarität des Meerwassers angepasst, also isoosmostisch zu diesem. Isoosmotisch oder leic ht hyperosmostisch zur Umgebung sind auch marine Neoselachier und Latimeria chalumnae (Actinistia), die dazu organische Osmolyte (Harnstoff und Trimethylaminoxid) im Blut akkumulieren (Osmokonformer). Bei anderen aquatischen Schädeltieren sind die Körperflüssigkeiten zur Umgebung hypoosmotisch (im Meerwasser) — sie halten Wasser zurück und scheiden anorganiche Ionen aus — oder hyperosmotisch (im Süßwasser), indem sie Wasser abgeben und anorganische Ionen aufnehmen.

  15. Beschallungstechnik, Beschallungsplanung und Simulation

    NASA Astrophysics Data System (ADS)

    Ahnert, Wolfgang; Goertz, Anselm

    Die primäre Aufgabe einer Lautsprecheranlage ist es, Musik, Sprache oder auch Signaltöne und Geräusche wiederzugeben. Diese können von einem Tonträger kommen (CD, Sprachspeicher), von einem anderen Ort übertragen (Zuspielung über Radio, TV, Telefon) oder vor Ort erzeugt werden. Letzteres umfasst Konzerte, Ansprachen, Durchsagen oder künstlerische Darbietungen, bei denen es meist darum geht, eine bereits vorhandene Quelle einer größeren oder weiter verteilten Anzahl von Personen zugänglich zu machen.

  16. Entwicklung und Formulierung der Unternehmensstrategie

    NASA Astrophysics Data System (ADS)

    Crespo, Isabel; Bergmann, Lars; Lacker, Thomas

    Ursprünglich stammt der Begriff "Strategie“ aus dem Altgriechischen: "strategos“ bedeutete "Heer“, "Heeresmacht“ und damit auch "konzentrierte Kraft“; das Wort "agein“ bedeutete "tun, machen, treiben“. Ein Stratege war also eine Person, die ein Heer führte und damit Kraft, Macht und Stärke konzentrierte und einsetzen konnte. Strategie bezeichnete dementsprechend die Maßnahmen, die in dieser Funktion entwickelt wurden. Daher ist es leicht verständlich, dass der Begriff Strategie bis in die Mitte des letzten Jahrhunderts in erster Linie militärisch verstanden wurde. Anschließend wurde der Begriff in weiteren Bereichen, wie beispielsweise der Unternehmensführung, verwendet. Im betriebswirtschaftlichen Sinne bedeutet der Begriff Strategie die langfristig geplante Verhaltensweise eines Unternehmens zur Erreichung seiner Ziele.

  17. Slowing down of 2-11 MeV 12C, 16O, 28Si and 63Cu heavy ions through Si3N4 thin foil by using Time-of-Flight spectrometry

    NASA Astrophysics Data System (ADS)

    Guesmia, A.; Msimanga, M.; Pineda-Vargas, C. A.; Ammi, H.; Dib, A.; Ster, M.

    2016-03-01

    The stopping force and the energy-loss straggling of 63Cu, 28Si, 16O and 12C partially stripped heavy ions crossing silicon nitride foil has been determined over a continuous range of energies 2-11 MeV, by using a method based on the Heavy Ion-Elastic Recoil Detection Analysis (HI-ERDA) technique using a Time of Flight (ToF) spectrometer. The obtained energy loss straggling values corrected for non-statistical straggling and the thickness variation using the Besenbacher's method have been analyzed and compared with the corresponding computed values. For computed electronic straggling we have used alternatively the widely used formulations such as, the universal Bohr straggling deduced from the Bohr stopping model, and the Lindhard-Scharff formula including the Bunching effect given by Hvelplund-Firsov formula according to the Besenbacher approach. The aim of such comparison is to check the reliability and accuracy of the existing energy loss straggling formulations, in the light of the present experimental results. The experimental results of energy loss straggling of all ions are found to be greater than those predicted by the Bohr stopping model or Lindhard-Scharff prediction model. The introduction of the bunching effect improves the comparison and gives an estimation of other effects such as charge exchange.

  18. Welt und Wirkungsprinzip (2nd Aufl.)

    NASA Astrophysics Data System (ADS)

    Landgraf, Werner

    2010-03-01

    Modell einer kausalen Bewirkung der Welt, und logische, geometrische, physikalische Interprätation dieser Kausalmenge und Fortwirkung der frühsten ihrer sukzessiv als echt Neues bewirkten und durch Vorhandenes oder Späteres nicht darstellbaren oder widerrufbaren Ereignisse als Dimensionen und sie verkörpernde primäre Naturkräfte, mit Korrespondenz zur beobachteten Welt und ihrer grundlegendsten Eigenschaften. Wirklich ist nur was wirkt, wo und wie. Entsprechend ist im Bogenelement statt der Eigenzeit die variante Anzahl Wirkungen relevant, 0 ≈ 1/h2 dS2 - 1/tpl2 (dt2 - 1/c2 {dq12 + G02/G2 [dq2,32 - ...]}) mit G0 = c4lpl/Epl ≈ G. Die heutigen Dimensionen und Naturkräfte entstanden in dieser Reihenfolge, haben 'komplementäre' aber gleichwertige statische und dynamische Aspekte, entsprechend ihren Termen in Bogenelement bzw. Vierervektor, aus derem Vergleich sowie mit denen ihrer Nachbarn folgen Grundgleichungen bzw. Erhaltungssätze. Jeweils individuelle Eigenschaften wie ihre Naturkonstante konkretisieren sie und tragen zu gattungsmäßigen wie globale Affinität und Äquivalenzen bei. Ältestes Gebiet oder räumlicher Rand jeder Dimension sind die ersten vom Vorgänger bewirkten Ereignisse, selbst raumzeitlicher Ursprung des Nachfolgers, dort einmalig und ewig maximal rotverschoben fortwirkend und nicht lokalisierbar, um neue Elementareinheiten verschieden und lichtartig mit deren Verhältnis oder dem ihrer globalen Zustandsgrößen als konstanten Anfangsimpuls, Expansion, Längen- oder Ereignisdichte zueinander. Der Übergang vom diskreten Modell weniger Informationen zum Kontinuum und die Korrespondenz zur Physik ist problemlos, Details wie ein kontinuierlicher, abrupter oder ganz fehlender Abfall der Metrik beim ältesten Gebiet sind aber nur durch Beobachtungen entscheidbar. Erörtert werden allgemeine und individuelle Eigenschaften und ihre Konsequenzen der Dimensionen mit ihren Kräften, selbst und im Verhältnis zueinander, etwa ihrer begrenzten

  19. The 28Si(d,α) reaction

    NASA Astrophysics Data System (ADS)

    Araujo-Escalona, V.; Acosta, L.; Andrade, E.; Barrón-Palos, L.; Cantó, C.; Favela, F.; Huerta, A.; Ortiz, M. E.; Solís, C.; Chávez, E.

    2016-07-01

    Recent techniques and experimental methods open up new ways to explore nuclear reactions relevant to nucleosynthesis at stellar combustion temperatures. In this work we focus on the case of 26Al, isotope associated with the identification of active nucleosynthesis spots in the cosmos. Its presence in the solar system was unexpected until it was found in the Allende meteorite. It is now understood that cosmic rays induce nuclear reactions to produce 26Al. On Earth, this process is well known and is the basis of many environmental studies. So 26Al is not just the product of some high-metallicity star collapse. Natural Silicon targets were irradiated with deuteron beams of energies between 0.9 and 2.6 MeV. The produced 26Al were counted later-on in an AMS facility. In this paper, we describe in detail the experimental protocol developed to quantify the number of deuterons hitting the target, as a first step to determine the total cross section.

  20. Restaurierung von Seen und Renaturierung von Seeufern

    NASA Astrophysics Data System (ADS)

    Grüneberg, Björn; Ostendorp, Wolfgang; Leßmann, Dieter; Wauer, Gerlinde; Nixdorf, Brigitte

    Süßwasserseen haben als ökosysteme und Lebensraum für Pflanzen und Tiere eine herausragende Bedeutung für die Artenvielfalt auf der Erde und prägen als Landschaftselemente unsere natürliche Umwelt. Seen fungieren als natürliche Stoffsenken, vor allem für Kohlenstoff und Nährstoffe, aber auch als Senken für in ihren Einzugsgebieten emittierte gelöste und feste Schadstoffe. Darüber hinaus ist Wasser eine wichtige Naturressource. Süßwasserseen stellen in den meisten Regionen der Erde lebenswichtige Quellen für die Versorgung mit Trinkwasser und tierischem Eiweiß (Fischfang) dar. Sie dienen als Wasserspeicher für die landwirtschaftliche und industrielle Nutzung. Auch für Erholungsaktivitäten des Menschen kommt ihnen eine große Bedeutung zu.

  1. Bewegungsapparat: Postcraniales Skelett und Muskulatur

    NASA Astrophysics Data System (ADS)

    Fischer, Martin S.

    Der Bewegungsapparat bestimmt die Form des Wirbeltierkörpers. So lässt sich z. B. aus der Gestalt eines Fisches auf seine bevorzugt e Schwimmweise schließen (S. 61). Bei den aquatisch en Schädeltieren dominiert die Fortbewegung mit axialem Antrieb; bei den meisten Tetrapoda findet sich eine Kombination aus axialem Antrieb und Bewegung durch Gliedmaßen. Selbst beim höchst spezialisierten Gang, der bipeden Bewegung des Menschen, sind Torsionsbewegungen des Rumpfes noch maßgeblich und bestimmen auch die Grundform des menschlichen Körpers (z. B. die Taille). Obwohl die verschiedenen Antriebsmechanismen eine funktionelle Einheit bilden, werden im Folgenden das Axialskelett sowie der Schulter- und Beckengürtel mit den zugehörigen Extremitäten getrennt besprochen.

  2. Kosmologie und Teilchenphysik.

    NASA Astrophysics Data System (ADS)

    Appenzeller, I.

    This book is a selection of 17 articles published in the journal "Spektrum der Wissenschaft". The original English versions of the papers were first published in "Scientific American". Contents: 1. Einführung (I. Appenzeller). 2. Sehr große Strukturen im Universum (J. O. Burns). 3. Die großräumigen Eigenbewegungen der Galaxien (A. Dressler). 4. Dunkle Materie im Universum (L. M. Krauss). 5. Der doppelte Beta-Zerfall (M. K. Moe, S. P. Rosen). 6. Quark-Lepton Familien (D. B. Cline). 7. Beschleunigerexperimente testen kosmologische Theorien (D. N. Schramm, G. Steigman). 8. Das Rätsel der kosmologischen Konstanten (L. Abbott). 9. Das Higgs-Boson (M. J. G. Veltman). 10. Die Suche nach dem Protonenzerfall (J. M. LoSecco, F. Reines, D. Sinclair). 11. Das inflationäre Universum (A. H. Guth, P. J. Steinhardt). 12. Die fünfte Dimension (E. Schmutzer). 13. Die verborgenen Dimensionen der Raumzeit (D. Z. Freedman, P. van Nieuwenhuizen). 14. Ist die Natur supersymmetrisch? (H. E. Haber, G. L. Kane). 15. Schwerkraft und Antimaterie (T. Goldman, R. J. Hughes, M. M. Nieto). 16. Superstrings (M. B. Green). 17. Kosmische Strings (A. Vilenkin).

  3. 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

  4. Lineare und verzweigte Blockcopolymere aus Polypeptiden und synthetischen Polymeren

    NASA Astrophysics Data System (ADS)

    Kukula, Hildegard

    2001-07-01

    Die vorliegende Arbeit beschäftigt sich mit der Synthese und den Eigenschaften von linearen und verzweigten amphiphilen Polypeptid-Blockcopolymeren. Die Frage nach dem Einfluss der Topologie und Konformation der Blockcopolymere auf die supramolekularen und kolloidalen Eigenschaften bildete einen wichtigen Aspekt bei den Untersuchungen. Die Blockcopolymere wurden nach einem mehrstufigen Reaktionsschema durch Kombination von anionischer und ringöffnender Polymerisation von Aminosäuren-N-Carboxyanhydriden (NCA) synthetisiert. Die Untersuchung der Polypeptid-Blockcopolymere hinsichtlich ihres Aggregationsverhaltens in fester Phase sowie in verdünnter wässriger Lösung erfolgte mittels Streumethoden (SAXS, WAXS, DLS) sowie abbildender Methoden (TEM). Durch Einsatz der Blockcopolymere als polymere Stabilisatoren in der Emulsionspolymerisation wurden Oberflächen funktionalisierte Latizes erhalten. Als Beispiel für eine pharmazeutische Anwendung wurden bioverträgliche Polypeptid-Blockcopolymere als Wirkstoff-Trägersysteme in der Krebstherapie eingesetzt. This work describes the synthesis and characterization of linear and branched polypeptide block copolymers having amphiphilic character. The studies focused on the impact of the block copolymers' conformation and architecture on the supramolecular and colloidal properties. The polypeptide block copolymers were prepared in a multi-step process involving the anionic synthesis of (poly)amino-functional polymers (polystyrene and polybutadiene) which where used as macroinitiators for the ring-opening polymerization of N-carboxyanhydrides (NCA) of protected a-aminoacids. Supramolecular structures of the block copolymers in the solid state as well as in diluted aqueous solution were investigated using scattering (SAXS, WAXS, DLS) and microscopic (TEM) methods. Both linear and branched polypeptide block copolymers were used as polymeric stabilizers in the emulsion polymerization of styrene to yield polypeptide

  5. Mittelwert- und Arbeitstaktsynchrone Simulation von Dieselmotoren

    NASA Astrophysics Data System (ADS)

    Zahn, Sebastian

    Getrieben durch die immer restriktiveren Anforderungen an das Emissions- und Verbrauchsverhalten moderner Verbrennungsmotoren steigt die Komplexität von Motormanagementsystemen mit jeder Modellgeneration an. Damit geht nicht nur eine Zunahme des Softwareumfangs von Steuergeräten sondern zugleich ein deutlicher Anstieg des Applikations-, Vermessungs- und Testaufwandes einher. Zur Effizienzsteigerung des Software- und Funktionsentwicklungsprozesses haben sich daher in der Automobilindustrie sowie in Forschungsinstituten verschiedene modell- und simulationsbasierte Methoden wie die Model-in-the-Loop (MiL) Simulation, die Software-in-the-Loop (SiL) Simulation, das Rapid Control Prototyping (RCP) sowie die Hardware-in-the-Loop (HiL) Simulation etabliert.

  6. Topika und deren Einsatz in der Dermatologie.

    PubMed

    Wohlrab, Johannes

    2016-11-01

    Grundkenntnisse zur Zusammensetzung und den regulatorischen Hintergründen von Topika gehören zu den alltäglich benötigten Herausforderungen dermatologisch-ärztlichen Handelns. Ein professioneller und indikationsgerechter Umgang bei der Auswahl, Verordnung und Anwendung topischer Präparate ist somit Voraussetzung für eine verantwortungsvolle fachärztliche Tätigkeit. Dabei bereiten die regulatorische Zuordnung (Arzneimittel, Medizinprodukt, Kosmetikum), die Feststellung der Erstattungsfähigkeit durch die GKV und die unzureichende Kennzeichnung des Vehikelsystems einzelner Präparate nicht selten Probleme. Bestreben sollte es sein, neben der Wahl des geeigneten Wirkstoffs und der geeigneten Konzentration ein an die Indikation der Therapie angepasstes galenisches System auszuwählen, um dessen Eigenwirkung für den therapeutischen Effekt nutzen zu können. Bei der Verschreibung von Rezepturarzneimitteln sollte nach Möglichkeit immer auf eine standardisierte Rezeptur (Magistralrezeptur) zurückgegriffen werden. Durch die Vielzahl der möglichen Inhaltsstoffe und der sich daraus ergebenden Komplexität eines galenischen Systems ist eine willkürliche Manipulation durch qualitative oder quantitative Veränderungen einzelner Komponenten mit hohen Risiken für eine Instabilität und damit für Sicherheit und Sinnhaftigkeit verbunden. Eine optimierte Anwendung von Topika setzt zudem Grundlagenkenntnisse zur Pharmakokinetik und zur evidenzbasierten Therapieplanung voraus.

  7. Ruhende Flüssigkeiten und Gase

    NASA Astrophysics Data System (ADS)

    Heintze, Joachim

    Das mechanische Verhalten von Flüssigkeiten und Gasen ist dadurch gekennzeichnet, dass sie keine statische Schubfestigkeit besitzen, andernfalls würden sie nicht beginnen, zu fließen. In ruhenden Flüssigkeiten und Gasen können daher keine Schubspannungen bestehen:

  8. Physik gestern und heute Das Eiskalorimeter

    NASA Astrophysics Data System (ADS)

    Heering, P.

    2003-07-01

    Kalorimetrische Messungen gehören heute zum experimentellen Standardrepertoire im Bereich der Thermodynamik und der physikalischen Chemie. Das erste Gerät für derartige Messungen entwickelten Ende des 18. Jahrhunderts die französischen Wissenschaftler Antoine Laurent Lavoisier und Pierre Simon de Laplace.

  9. Quantitative Analyse und Visualisierung der Herzfunktionen

    NASA Astrophysics Data System (ADS)

    Sauer, Anne; Schwarz, Tobias; Engel, Nicole; Seitel, Mathias; Kenngott, Hannes; Mohrhardt, Carsten; Loßnitzer, Dirk; Giannitsis, Evangelos; Katus, Hugo A.; Meinzer, Hans-Peter

    Die computergestützte bildbasierte Analyse der Herzfunktionen ist mittlerweile Standard in der Kardiologie. Die verfügbaren Produkte erfordern meist ein hohes Maß an Benutzerinteraktion und somit einen erhöhten Zeitaufwand. In dieser Arbeit wird ein Ansatz vorgestellt, der dem Kardiologen eine größtenteils automatische Analyse der Herzfunktionen mittels MRT-Bilddaten ermöglicht und damit Zeitersparnis schafft. Hierbei werden alle relevanten herzphysiologsichen Parameter berechnet und mithilfe von Diagrammen und Graphen visualisiert. Diese Berechnungen werden evaluiert, indem die ermittelten Werte mit manuell vermessenen verglichen werden. Der hierbei berechnete mittlere Fehler liegt mit 2,85 mm für die Wanddicke und 1,61 mm für die Wanddickenzunahme immer noch im Bereich einer Pixelgrösse der verwendeten Bilder.

  10. Dentalwerkstoffe und Dentalimplantate - Teil 2

    NASA Astrophysics Data System (ADS)

    Faltermeier, Andreas

    Wie in allen Bereichen der Medizin findet auch in der Zahnmedizin eine kontinuierliche Weiterentwicklung der verwendeten Werkstoffe statt. Gerade für Zahnersatz werden Werkstoffe gesucht, die zum einen ästhetisch, zum anderen haltbar und darüber hinaus auch körperverträglich sind. Auch steigt immer mehr der Wunsch der Patienten nach ästhetischen und zugleich biokompatiblen Materialien. Wurde früher fast ausschließlich als Füllungsmaterial im Seitenzahngebiet quecksilberhaltiges Amalgam verwendet, hat der Zahnarzt heutzutage eine große Auswahl an verschiedenen zahnfarbenen Materialien: zum einen werden sog. Komposite verwendet, das aus einer Polymermatrix mit eingebetteten Füllstoffen besteht, zum anderen können diverse Dentalkeramiken verwendet werden. Besonders die Verwendung von Hochleistungskeramiken, wie beispielsweise Zirkonoxid, das sich bereits als Bremsscheiben für Sportwägen, Hitzeschilde im Space Shuttle und als Kugelköpfe künstlicher Hüftgelenke bewährt hat, spielt heutzutage eine große Rolle bei der Verdrängung des Metalls aus der Mundhöhle. War es früher nur möglich, einen verloren gegangen Zahn mittels einer Brücke, die ein Beschleifen der Nachbarzähne zur Folge hat, oder durch herausnehmbaren Zahnersatz zu ersetzen, ist es heutzutage mit der modernen Implantologie möglich, Zahnersatz zahnschonend einzugliedern. Auch kann mittels Dentalimplantaten dem Wunsch vieler Patienten nach festem Zahnersatz anstelle eines herausnehmbaren Zahnersatzes entsprochen werden. So kann mit Hilfe neuer biokompatiblen Werkstoffe sowohl der ästhetische Anspruch befriedigt als auch das Selbstwertgefühl vieler Patienten angehoben werden.

  11. Aufbau und Anpassung der Motorsteuerungs-Software für Otto- und Dieselmotoren

    NASA Astrophysics Data System (ADS)

    Stuhler, Harald; Ricken, Volker; Diener, René

    Die Erfüllung steigender Kundenansprüche und strenger gesetzlicher Vorgaben hinsichtlich der Verringerung des Kraftstoffverbrauchs, der Reduzierung von Schadstoffemissionen, der Erhöhung von Fahrsicherheit, Fahrleistung und Fahrkomfort ist untrennbar mit dem Einzug elektronischer Systeme in moderne Kraftfahrzeuge verbunden. Die elektronischen Systeme bestimmen zunehmend den Kundennutzen und werden für die Differenzierung der Automobilhersteller untereinander immer wichtiger. Daher sind sie ein wesentlicher Erfolgsfaktor moderner Kraftfahrzeuge.

  12. Systemlieferant und OEM Hersteller für die Medizintechnik und Pharmabranche

    NASA Astrophysics Data System (ADS)

    Jakob, Thomas; Reichenberger, Robert

    Unter einem Original Equipment Manufacturer (OEM) versteht man einen Hersteller fertiger Komponenten oder Produkte, der diese in seinen eigenen Produktionsfabriken produziert, sie aber anschließend nicht selbst in den Handel bringt. Die Anforderungen an einen OEM für die Medizintechnik- und Pharmabranche sind weitaus komplexer und umfangreicher als in anderen Branchen. Diese zusätzlichen Anforderungen haben schließlich auch ihre Berechtigung, da es letztendlich immer um die Gesundheit und das Leben von Menschen geht. Ein OEM muss neben der heute immer stärker geforderten Flexibilität, Schnelligkeit und Wettbewerbsfähigkeit sämtliche für die Medizintechnik- und Pharmabranche erforderlichen Qualitäts- und Prozesssicherheitskriterien erfüllen. Entsprechende Nachweise sind durch regelmäßige Kunden- und Überwachungsaudits zu erbringen. Das Arbeitsumfeld eines OEM für die Medizintechnik- und Pharmabranche bezieht sich somit nicht nur auf die Herstellung der Produkte für seine Kunden, sondern auch auf die Einhaltung sämtlicher Normen, Sicherheitskriterien, regulatorischen Voraussetzungen und Gesetze die zur Herstellung der Produkte notwendig sind.

  13. PCR und Real-Time PCR

    NASA Astrophysics Data System (ADS)

    Konrad, Regina; Busch, Ulrich

    Die vielfältigen Anwendungsmöglichkeiten der Polymerasekettenreaktion (polymerase chain reaction, PCR) machen sie zu einer der wichtigsten und am häufigsten eingesetzten Methoden in der molekularbiologischen Forschung und Diagnostik. Für diese Technologie wurde der Erfinder der Methode, Kary Mullis, 1993 mit dem Nobelpreis ausgezeichnet. Die PCR erlaubt einen hochsensitiven und spezifischen in-vitro-Nachweis von Desoxyribonukleinsäuren (DNA), da im Zuge der Reaktion Sequenzabschnitte gezielt vermehrt werden. Innerhalb weniger Stunden können aus einem einzigen Zielmolekül 1012 identische Moleküle entstehen [1].

  14. Hochschule fur Film und Fernsehen (Babelsberg).

    ERIC Educational Resources Information Center

    Neumann, Roland

    1992-01-01

    Describes the Hochschule fur Film und Fernsehen, an institution of higher education for the study of film and television production in Babelsberg, Germany (formerly the German Democratic Republic). Discusses the major reorientations in the school caused by Germany's reunification. (SR)

  15. Satellitenbewegung, band III: Natiirliche und gesteuerte bewegung.

    NASA Astrophysics Data System (ADS)

    Jochim, E. F.

    2014-12-01

    Im dritten Band der Satellitenbewegung werden in fortlaufender Nummerierung einige für Untersuchungen der Bewegung der künstlichen Satelliten wichtige Grundlagen der Astrodynamik mit ausführlichen mathematischen Formelsystemen behandelt. Dazu zählen die unterschiedlichen Aspekte der Bewegung der natürlichen Himmelskörper, die Steuerung und Kontrolle von künstlichen Objekten, und insbesondere die für eine Satellitenbahnanalyse wichtigen physikalischen Beeinflussungen einer Satellitenbewegung. Mathematisch entscheidend ist die Wahl geeigneter Bahnparameter, die ein bestimmtes Bewegungsproblem widerspruchsfrei und singularitätenfrei zu behandeln gestatten. Für die Behandlung routinemäßiger Aufgabenstellungen der Satellitenbewegung, in erster Linie einer präzisen Bahnbestimmung und Bahnverbesserung, kann auf eine Fülle von lehrbuchartigen Monographien verwiesen werden, so dass diese Problematik in der vorliegenden Arbeit nur angedeutet werden soll.

  16. Kosmische Katastrophen und der Ursprung der Religion.

    NASA Astrophysics Data System (ADS)

    Hoyle, F.

    This book is a German translation, by V. Delavre, from the English original "The origin of the Universe and the origin of religion", published in 1993. Contents: E. Sens: Die unterbrochene Musikstunde. Einleitung zur deutschen Ausgabe. C. Ryskamp: Einführung. R. N. Anshen: Vorwort. F. Hoyle: Kosmische Katastrophen und der Ursprung der Religion - Die Folgen der Respektabilität; Eiszeiten und Kometen; Die allgemeine Situation in den Nacheiszeiten; Kometen und der Ursprung der Religionen; Der Übergang zu Mittelalter und Neuzeit. Diskussionsbeiträge: Ruth Nanda Anshen, Freeman Dyson, Paul Oscar Kristeller, John Archibald Wheeler, James Schwartz, Roger Shinn, Milton Gatch, Philip Solomon, Norman Newell. F. Hoyle: Schlußwort. A. Tollmann: Nachwort zur deutschen Ausgabe.

  17. Uniform National Discharge Standards (UNDS): Outreach

    EPA Pesticide Factsheets

    Describes the Federalism and Tribal consultation efforts related to the Uniform National Discharge Standards (UNDS) and links to copies of each presentation, both to state and local representatives, as well as federally-recognized tribes.

  18. Positionsbestimmung des Unternehmens: Interne und externe Analyse

    NASA Astrophysics Data System (ADS)

    Bergmann, Lars; Crespo, Isabel; Portmann, Stefan

    Die Initiierung und Lenkung von Maßnahmen zur integrierten Modernisierung zielen auf die Verbesserung der Wettbewerbsfähigkeit eines Unternehmens ab. Damit diese Maßnahmen zielgerichtet die Wettbewerbsfähigkeit verbessern können, ist Wissen über die bestehende Wettbewerbsfähigkeit sowie über die bestehenden Fähigkeiten eine zentrale Voraussetzung. Eine zielgerichtete Auswahl problemadäquater Maßnahmen zur Verbesserung der Wettbewerbsfähigkeit bedarf daher im Vorfeld einer Bewertung der aktuellen Situation des Unternehmens im Sinne einer Positionsbestimmung. Erst wenn die internen Stärken und Schwächen sowie die externen Chancen und Risiken identifiziert sind, kann ein ganzheitliches Bild von der Position eines Unternehmens in seiner Umwelt gewonnen werden. Auf Basis der Kenntnisse über die Position des Unternehmens können anschließend zielgerichtet Maßnahmen ausgewählt werden, die einen Beitrag zur Verbesserung der Wettbewerbsfähigkeit des Unternehmens haben. Damit kommt der Positionsbestimmung als initialer Schritt des Prozesses der strategischen Unternehmensplanung eine zentrale Bedeutung im Rahmen der integrierten Modernisierung zu. Erfolgt die Auswahl von Maßnahmen ohne eine vorherige Positionsbestimmung, also lediglich auf Basis drängender Probleme, so besteht die Gefahr einer unbedachten und nur auf das "hier und heute“ bezogenen Schwerpunktbildung ohne Berücksichtigung der mittel- und langfristigen Ziele des Unternehmens.

  19. Tycho Brahe - Instrumentenbauer und Meister der Beobachtungstechnik

    NASA Astrophysics Data System (ADS)

    Wolfschmidt, Gudrun

    Vor der Erfindung des Fernrohrs war der dänische Astronom Tycho Brahe (1546 - 1601) der bedeutendste beobachtende Astronom. Von seinem Observatorium Uraniborg auf der - damals dänischen - Insel Hven ist heute noch der Grundriß erkennbar, von Stjerneborg sind die Fundamente erhalten, die Kuppeln in den 1950er Jahren ergänzt. In der Astronomie-Ausstellung im Deutschen Museum gibt es ein Modell der Sternwarte Uraniborg und der zugehörigen Instrumente (Maßstab 1:10); das größere Modell wurde dem Technischen Museum in Malmö geschenkt. Die Instrumente, die er in den Observatorien Uraniborg und Stjerneborg benutzte, sind nicht erhalten. Aber es gibt gute Beschreibungen der Instrumente (Halbkreis, Quadranten, Sextanten, Armillarsphären, Triquetrum, Himmelsglobus) in seinem Buch Astronomiae instauratae mechanica (Wandsbek 1598). Eine Nachbildung des großen hölzernen Quadranten kann man im Runden Turm in Kopenhagen sehen. Zwei Sextanten, hergestellt für Tycho um 1600 von Jost Bürgi und Erasmus Habermel, gibt es noch im Nationalmuseum für Technik in Prag. Ähnlichkeiten von Tychos Instrumenten mit Groß-Instrumenten aus dem islamischen Kulturkreis sind auffällig. Tycho Brahes Meßgeräte markieren einen großen Fortschritt in der Entwicklung astronomischer Instrumente und Meßtechniken und bilden die Grundlage für den weiteren Fortschritt der Positionsastronomie und der damit verbundenen Tabellenwerke. Die Nachwirkungen sind bis ins 17. und 18. Jahrhundert nachweisbar.

  20. Ökologische Grundlagen und limitierende Faktoren der Renaturierung

    NASA Astrophysics Data System (ADS)

    Hölzel, N.; Rebele, F.; Rosenthal, G.; Eichberg, C.

    In den dicht besiedelten und agrarisch besonders intensiv genutzten Regionen Mittel- und Westeuropas ist seit Ende des Zweiten Weltkrieges ein fortschreitender Verlust an naturnahen ökosystemen mit hoher biologischer Vielfalt zu verzeichnen. Spätestens seit den 1970er-Jahren ist daher die Neuschaffung und Wiederherstellung gefährdeter Lebensräume und Biozönosen zunehmend in den Mittelpunkt von Naturschutzmaßnahmen gerückt (Bakker 1989, Muller et al. 1998, Bakker und Berendse 1999). Aufgrund fehlender wissenschaftlicher Grundlagen und praktischer Erfahrungen wurden Renaturierungsmaßnahmen anfangs fast durchweg nach dem trial and error-Prinzip durchgeführt. Im Vordergrund standen dabei zunächst die Wiederherstellung adäquater abiotischer Standortbedingungen sowie die Reorganisation traditioneller Nutzungsmanagements. Bei Ersterem ging es neben der Wiedervernässung entwässerter Feuchtgebiete (Pfadenhauer und Grootjans 1999) vor allem darum, Eutrophierungseffekte zu beseitigen und die Produktivität des Standortes auf das Niveau der Zielgemeinschaft zurückzuführen (Gough und Marrs 1990, Oomes et al. 1996, Snow et al. 1997, Tallowin et al. 1998).

  1. Modellgestützte Hybrid Systementwicklung - Modellierung und Optimierung

    NASA Astrophysics Data System (ADS)

    Huber, Thomas

    Im Bereich der Hybridfahrzeugentwicklung wird nach wie vor intensiv an Konzepten zur Verbrauchseinsparung und Reduzierung von Emissionen gearbeitet. Gleichzeitig sollen "Fahrspaß" und Komfort solcher Fahrzeuge verbessert werden. Für verschiedene Anwendungen sind unterschiedlichste Hybridkonzepte denkbar und sinnvoll. Trotz dieser Variantenvielfalt und den daraus resultierenden technischen Anforderungen sind die Kosten eines Hybridfahrzeugs zu minimieren, wobei ein wesentlicher Aspekt bei der Kostenreduzierung die Stückzahl ist. Bei der Entwicklung von Komponenten steht daher, neben den technischen Anforderungen, deren vielseitige Einsetzbarkeit im Vordergrund.

  2. An Exchange-Only Qubit in Isotopically Enriched 28Si

    NASA Astrophysics Data System (ADS)

    Gyure, Mark

    2015-03-01

    We demonstrate coherent manipulation and universal control of a qubit composed of a triple quantum dot implemented in an isotopically enhanced Si/SiGe heterostructure, which requires no local AC or DC magnetic fields for operation. Strong control over tunnel rates is enabled by a dopantless, accumulation-only device design, and an integrated measurement dot enables single-shot measurement. Reduction of magnetic noise is achieved via isotopic purification of the silicon quantum well. We demonstrate universal control using composite pulses and employ these pulses for spin-echo-type sequences to measure both magnetic noise and charge noise. The noise measured is sufficiently low to enable the long pulse sequences required for exchange-only quantum information processing. Sponsored by United States Department of Defense. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressly or implied, of the United States Department of Defense or the U.S. Government. Approved for public release, distribution unlimited.

  3. Darwin, Engels und die Rolle der Arbeit in der biologischen und kulturellen Evolution des Menschen

    NASA Astrophysics Data System (ADS)

    Reichholf, Josef H.

    Im Jahre 1876, 5 Jahre nach Erscheinen von Darwins Buch über die Evolution des Menschen und die sexuelle Selektion (Darwin 1871), veröffentlichte Friedrich Engels den berühmt gewordenen Essay "Anteil der Arbeit an der Menschwerdung des Affen“ (Engels 1876). Die Kernfrage darin lautet in Kurzform: Warum hat der Mensch eigentlich ein Bedürfnis nach Arbeit? Engels Antwort wird nachfolgend näher betrachtet und vom gegenwärtigen Kenntnisstand aus beurteilt. Wie sich zeigen wird, beantworten seine Überlegungen die Frage nicht wirklich. Sie ist weiterhin offen. Es können lediglich einige zusätzliche Anhaltspunkte zur Diskussion gestellt werden. Angesichts des drängenden Problems millionenfacher Arbeitslosigkeit und der Forderungen nach einem "Grundrecht auf Arbeit“ kommt den Überlegungen zum möglichen Ursprung des Bedürfnisses nach Arbeit mehr als nur akademisches Interesse zu.

  4. Implantate und Verfahren in der Augenheilkunde

    NASA Astrophysics Data System (ADS)

    Neuhann, Tobias H.

    Das in der Medizin mit am häufigsten verwendete Implantat weltweit ist die Intraokulare Linse (IOL). Die Gründe hierfür sind vielschichtig: einmal haben die Operationstechniken in den letzten 30 Jahren eine wesentliche Steigerung an Gleichmäßigkeit, Erfolg und Effizienz erfahren, zum anderen verursachen die gestiegenen Anforderungen des Alltags in den Industrienationen und im Berufsleben den höheren Anspruch an das Sehvermögen. Ist die menschliche Linse Ursache für schlechtes Sehvermögen, besteht meist eine Trübung des Linsenproteins. Diese Trübung nennt wird Volksmund Grauer Star genannt, wissenschaftlich die Katarakt (cataracta). Es gibt unterschiedliche Formen wie angeborene (congenita) oder erworbene, traumatische, krankheitsoder altersbedingte Formen [45]. Wird die eingetrübte Linse nun mittels moderner Operationsverfahren entfernt, muss für Ersatz dieses lichtbrechenden Mediums gesorgt werden [2].

  5. Haptische Modellierung und Deformation einer Kugelzelle

    NASA Astrophysics Data System (ADS)

    Schippritt, Darius; Wiemann, Martin; Lipinski, Hans-Gerd

    Haptische Simulationsmodelle dienen in der Medizin in erster Linie dem Training operativer Eingriffe. Sie basieren zumeist auf physikalischen Gewebemodellen, welche eine sehr genaue Simulation der biomechanischen Eigenschaften des betreffenden Gewebes erlauben, aber gleichzeitig sehr rechenintensiv und damit zeitaufwändig in der Ausführung sind. Die menschliche Wahrnehmung kann allerdings auch eine ungenaue haptische Modellierung psychooptisch ausgleichen. Daher kann es sinnvoll sein, haptische Simulationen auch mit nicht vollständig physikalisch definierten Deformationsmodellen durchzuführen. Am Beispiel der haptischer Simulation einer in-vitro Fertilisation wird gezeigt, dass durch die Anwendung eines geometrischen Deformationsmodells eine künstliche Befruchtung unter realistischen experimentellen Bedingungen in Echtzeit haptisch simuliert und damit trainiert werden kann.

  6. Herstellung von Chitosan und einige Anwendungen

    NASA Astrophysics Data System (ADS)

    Struszczyk, Marcin Henryk

    2001-05-01

    1. Die Deacetylierung von crabshell - Chitosan führte gleichzeitig zu einem drastischen Abfall der mittleren viscosimetrischen Molmasse ( Mv), insbesondere wenn die Temperatur und die Konzentration an NaOH erhöht werden. Diese Parameter beeinflussten jedoch nicht den Grad der Deacetylierung (DD). Wichtig ist jedoch die Quelle des Ausgangsmaterials: Chitin aus Pandalus borealis ist ein guter Rohstoff für die Herstellung von Chitosan mit niedrigem DD und gleichzeitig hoher mittlerer Mv, während Krill-Chitin (Euphausia superba) ein gutes Ausgangsmaterial zur Herstellung von Chitosan mit hohem DD und niedrigem Mv ist. Chitosan, das aus Insekten (Calliphora erythrocephala), unter milden Bedingungen (Temperatur: 100°C, NaOH-Konzentration: 40 %, Zeit: 1-2h ) hergestellt wurde, hatte die gleichen Eigenschaften hinsichtlich DD und Mv wie das aus Krill hergestellte Chitosan. Der Bedarf an Zeit, Energie und NaOH ist für die Herstellung von Insekten-Chitosan geringer als für crabshell-Chitosan vergleichbare Resultaten für DD und Mv. 2. Chitosan wurde durch den Schimmelpilz Aspergillus fumigatus zu Chitooligomeren fermentiert. Die Ausbeute beträgt 25%. Die Chitooligomere wurden mit Hilfe von HPLC und MALDI-TOF-Massenspektrmetrie identifiziert. Die Fermentationsmischung fördert die Immunität von Pflanzen gegen Bakterien und Virusinfektion. Die Zunahme der Immunität schwankt jedoch je nach System Pflanze-Pathogen. Die Fermentation von Chitosan durch Aspergillus fumigatus könnte eine schnelle und billige Methode zur Herstellung von Chitooligomeren mit guter Reinheit und Ausbeute sein. Eine partiell aufgereinigte Fermentationsmischung dieser Art könnte in der Landwirtschaft als Pathogeninhibitor genutzt werden. Durch kontrollierte Fermentation, die Chitooligomere in definierter Zusammensetzung (d.h. definierter Verteilung des Depolymerisationsgrades) liefert, könnte man zu Mischungen kommen, die für die jeweilige Anwendung eine optimale Bioaktivität besitzen. 3

  7. Grundlagen und Vollzug der amtlichen Lebensmittelkontrolle in der Schweiz

    NASA Astrophysics Data System (ADS)

    Hübner, Philipp; Spinner, Christoph

    In der Schweiz wird die Mehrheit der hoheitlichen Aufgaben von den 26 Kantonen, die zusammen die schweizerische Eidgenossenschaft bilden, autonom vollzogen. So liegt zum Beispiel die Kompetenz in den Bereichen Steuern, Gesundheit, Schulen oder Polizei grundsätzlich bei den Kantonen. Im Gegensatz dazu ist die Lebensmittelgesetzgebung national durch eidgenössische Erlasse harmonisiert. Die Vollzugsaufgaben liegen aber auch in diesem Bereich, abgesehen vom Vollzug an der Grenze und von einer nationalen Vollzugsaufsicht und Weisungsberechtigung, in kantonaler Kompetenz. Die Kantone können anhand kantonaler Erlasse das Bundesrecht präzisieren - insbesondere die organisatorischen Aspekte - und Regelungen im nicht harmonisierten Bereich treffen.

  8. Methodik und Qualität statistischer Erhebungen

    NASA Astrophysics Data System (ADS)

    Krug, Walter; Schmidt, Jürgen; Wiegert, Rolf

    Kapitel 8 wirft einen Blick hinter die Kulissen statistischer Arbeit und ihrer Methoden, insbesondere auch hinter die der amtlichen Statistik: Wie kommen die Myriaden von Zahlen zustande, die heute aus statistischen Quellenwerken aller Art und aus Datenbanken abgerufen werden können? Dabei wird deutlich, welche Schwierigkeiten bei Erhebungen, insbesondere bei Stichprobenerhebungen, zu überwinden sind, wie man Antwortverweigerer kooperativer stimmt, wie sich auch aus kleinen Stichproben auf intelligente Weise verlässliche Ergebnisse erzielen lassen und wie Großstichproben auf europäischer Ebene harmonisiert werden. Am Beispiel des Zensus 2011 wird gezeigt, wie sich eine Kombination von Stichproben und Registerauswertungen als Ersatz für eine Volkszählung nutzen lässt. Mitglieder der Deutschen Statistischen Gesellschaft waren daran kooperativ beteiligt.

  9. Konstruieren von Pkw-Karosserien: Grundlagen, Elemente und Baugruppen, Vorschriftenübersicht, Beispiele mit CATIA V4 und V5

    NASA Astrophysics Data System (ADS)

    Grabner, Jörg; Nothhaft, Richard

    Die Faszination, die vom Auto ausgeht, ist und bleibt ungebrochen. Entsprechend interessant ist es, sich vor dem Hintergrund konventioneller Konstruktionstechniken über die virtuelle Produktentwicklung von Pkw-Karosserien an modernen CAD-Arbeitsplätzen informieren zu können. Die Autoren führen in die Grundlagen ein und zeigen anhand von Beispielen und zahlreichen Abbildungen, wie mit dem System CATIA der Rohbau sowie die Ausstattung innen und au=C3=9Fen konstruiert werden. Darüber hinaus wird das so genannte "Package" an Beispielen beschrieben, also das Management und die Harmonisierung der Anforderungen an die Bauräume (z.

  10. Physik gestern und heute Von der Metallstange zum Hochenergielaser

    NASA Astrophysics Data System (ADS)

    Heering, Peter

    2002-05-01

    Im Mai 1752 wurde in Marly bei Paris auf Anregung des amerikanischen Forschers und Politikers Benjamin Franklin erstmals die elektrische Natur des Blitzes nachgewiesen. Damals beschrieb Franklin auch eine technische Vorrichtung, die als Schutz von Gebäuden vor Blitzschlägen dienen sollte: den Blitzableiter. Diese aus heutiger Sicht scheinbar triviale Vorrichtung wurde aber keineswegs unmittelbar akzeptiert. Und bis heute ist die Forschung zum Schutz von Einrichtungen vor Blitzschlägen nicht abgeschlossen.

  11. S1-Leitlinie zur UV-Phototherapie und Photochemotherapie.

    PubMed

    Herzinger, Thomas; Berneburg, Mark; Ghoreschi, Kamran; Gollnick, Harald; Hölzle, Erhard; Hönigsmann, Herbert; Lehmann, Percy; Peters, Thorsten; Röcken, Martin; Scharffetter-Kochanek, Karin; Schwarz, Thomas; Simon, Jan; Tanew, Adrian; Weichenthal, Michael

    2016-08-01

    Die heilsame Wirkung des Sonnenlichts war teilweise schon im Altertum bekannt und fand in der zweiten Hälfte des 19. Jahrhunderts wieder zunehmend Beachtung. Den Beginn der modernen Phototherapien markiert die Entwicklung einer Apparatur zur ultravioletten Bestrahlung der Hauttuberkulose durch Finnsen zu Beginn des zwanzigsten Jahrhunderts. Zur Therapie von Hauterkrankungen finden beinahe ausschließlich die spektralen Bereiche unterhalb des sichtbaren Lichtes (ultraviolett) Anwendung. Seit den 1970er Jahren stehen zunehmend leistungsfähige künstliche Strahlenquellen bereit für die Therapie mit UVB, UVA und die Kombination von UVA mit Photosensibilisatoren (Photochemotherapie). Hohe strukturelle und prozedurale Qualitätsstandards sind unabdingbare Voraussetzung für die Durchführung einer gleichermaßen wirkungsvollen wie auch sicheren Phototherapie. Die Leitlinie formuliert den aktuellen Konsens führender Experten auf dem Gebiet der Phototherapie in Bezug auf die Indikationen für die jeweiligen Therapieverfahren, deren Gegenanzeigen und Nebenwirkungen und insbesondere für die Wahl der korrekten Dosis zu Beginn und im Verlauf einer Therapie sowie das Management von Nebenwirkungen.

  12. Zahlen und Rechenvorgänge auf unterschiedlichen Abstraktionsniveaus

    NASA Astrophysics Data System (ADS)

    Rödler, Klaus

    "Das Verständnis geht langsam vor sich!" Diesen wichtigen Satz hörte ich bei einem Vortrag von Martin Lowsky. Auf die hier behandelte Fragestellung übertragen heißt das: Was eine Zahl ist und wie ich sie im Rechenvorgang einsetzen und interpretieren kann, das erschließt sich erst allmählich. Die Zahl des Rechenanfängers ist nicht dieselbe wie die des kompetenten Rechners und es ist nicht die Zahl des Lehrers oder der Lehrerin. Die Zahlen sind nur auf der Oberfläche der Worte und Zeichen gleich. Im Innern, im Verständnis, sind sie völlig verschieden! Ich glaube, dass die Missachtung dieser Divergenz dazu führt, dass manche Kinder in für den Lehrer und Lehrerin nicht nachvollziehbaren Routinen stecken bleiben, einfachste Informationen nicht wirklich integrieren. Die auf beiden Seiten wachsende Verunsicherung durch die nicht erkannte und daher nicht kommunizierbare Diskrepanz im inneren Zahlkonzept stört den allmählichen Aufbau strukturierter Zahlvorstellungen.

  13. Modifications of und rbcS in und Synechococcus sp. PCC7942 resulted in high CO sub 2 requiring mutants

    SciTech Connect

    Schwarz, R.; Liehman-Hurwitz, J.; Martinez, F.; Reinhold, L.; Kaplan, A. )

    1990-05-01

    High CO{sub 2} requiring mutants (HCR), capable of growing in the presence of kanamycin, were obtained following transformation with a construct containing {und nptII} in the coding region of rbcS (encoding for the small subunit (SS) of Rubisco). The apparent photosynthetic affinity for inorganic carbon was very low in mutant EK6 whereas in mutant JR12 it was only slightly lower than in high-CO{sub 2}-grown wild type. Southern analysis indicated double crossing over in the case of EK6. In mutant JR12 Southern analysis revealed some rearrangement and a deletion of a region downstream fro {und rbcS}. Western analysis demonstrated normal SS in JR12 but a larger (by about 3 kD) SS in EK6. Sequence analysis indicated that the latter was the result of fusion between {und rbcS} and the flanking region of {und nptII}.

  14. Regelungen im Verkehr mit Lebensmitteln und Bedarfsgegenständen in Deutschland

    NASA Astrophysics Data System (ADS)

    Thomas, Gundula; Freund, Astrid; Gründig, Friedrich

    Im Zuge der Globalisierung von Produktion und Handel ändert sich auch der Charakter der Vorschriften im Lebensmittelrecht. Zunehmend treten internationale Rechtsbestimmungen, Abkommen, Standards und andere Normen an die Stelle nationaler Regelungen.

  15. VDI-Richtlinien - mit Technischen Regeln Wirtschaftlichkeit erhöhen und Standards setzen

    NASA Astrophysics Data System (ADS)

    Mandelartz, Johannes

    Der Verein Deutscher Ingenieure e.V. (VDI) ist ein gemeinnütziger, wirtschaftlich und politisch unabhängiger, technisch-wissenschaftlicher Verein von Ingenieuren und Naturwissenschaftlern. Mit über 137 000 persönlich zugeordneten Mitgliedern ist er eine der größten Ingenieur-Vereinigungen Europas und gilt in Deutschland als führender Sprecher der Technik und der Ingenieure. 1856 gegründet, hat er viele für die Technik wesentliche Entwicklungen in Gang gesetzt, so im Bereich der technischen Überwachung, der technischen Regelsetzung und Normung, der Arbeitsstudien, im gewerblichen Rechtsschutz und im Patentwesen. Seit seiner Gründung sieht es der VDI als seine Aufgabe, "das Zusammenwirken aller geistiger Kräfte der Technik im Bewusstsein ethischer Verantwortung zu fördern“ und die Lebensmöglichkeiten aller Menschen durch Entwicklung und sinnvoller Anwendung technischer Mittel zu verbessern.

  16. Verbesserte Ausbildung für neue Betriebsleiter und -ingenieure - eine wichtige Investition in die Zukunft

    NASA Astrophysics Data System (ADS)

    Franta, Oliver

    Bedingt durch die Globalisierung und die damit einhergehende Verschärfung des Wettbewerbs befinden sich die Produktionsbetriebe der chemischen Industrie in stetigem Wandel. Für Betriebsleiter und Betriebsingenieure werden damit Fähigkeiten wie Kostenmanagement, Sozial- und Organisationskompetenz, Führungsqualifikationen und unternehmerisches Handeln immer wichtiger. Neben den Anforderungsprofilen bei Neueinstellungen ist dies auch bei der Fortbildung zu berücksichtigen. Das Trainingsprogramm der Evonik Degussa wurde daher durch die Konzeption neuer Seminare und die Anpassung bestehender Weiterbildungsmaßnahmen weiterentwickelt. Neben Vorträgen und Fallbeispielen sind ebenfalls die Durchführung von Planspielen sowie das Kennenlernen eines Produktionsbetriebes einer anderen Organisationseinheit enthalten. Ziel ist es vor allem die unternehmerische Orientierung neuer Betriebsleiter und -ingenieure zu fördern, die Innovationsgeschwindigkeit zu erhöhen und durch Kenntnis und Nutzung bereits anderweitig entwickelter Lösungen und Methoden die Produktivität zu steigern. Die Produktionsmeister werden aufgrund der Bedeutung dieser Funktion für die Führung der Mitarbeiter und bei der Umsetzung von Veränderungsprojekten in das Ausbildungsprogramm einbezogen. Der Erfolg des Trainingsprogramms zeigt sich an den Teilnehmerzahlen und den ausgesprochen positiven Rückmeldungen.

  17. Nicolaus Copernicus Gesamtausgabe. Band VI/1. Documenta Copernicana: Briefe (Texte und Übersetzungen).

    NASA Astrophysics Data System (ADS)

    Kühne, A.

    Im Auftrage der Kommission für die Copernicus-Gesamtausgabe, herausgegeben von H. M. Nobis und M. Folkerts. Band VI/1 wurde bearbeitet von A. Kühne unter Mitarbeit von F. Boockmann und S. Kirschner und Verwendung der Vorarbeiten von H. M. Nobis.

  18. Ökophysik: Plaudereien über das Leben auf dem Land, im Wasser und in der Luft

    NASA Astrophysics Data System (ADS)

    Nachtigall, W.

    Prof. em. Dr. rer. nat. Werner Nachtigall, geb. 1934, war als Zoophysiologe und Biophysiker Leiter des Zoologischen Instituts der Universität des Saarlandes in Saarbrücken. In Forschung und Ausbildung hat er sich insbesondere mit Aspekten der Technischen Biologie und Bionik befasst und mit seinen Forschergruppen viele Basisdaten insbesondere zur Ökologie, Physiologie und Physik des Fliegens und Schwimmens aber auch zur Stabilität beispielsweise der Gräser erarbeitet. Lebewesen überraschen immer wieder durch ihre "Biodiversität", ihre hochspezifischen Ausgestaltungen und Anpassungen.

  19. Herschel und die Zukunft der Fern-Infrarot-Astronomie

    NASA Astrophysics Data System (ADS)

    Linz, Hendrik

    2015-06-01

    Schon lange ist die beobachtende Astronomie den engen Grenzen des optisch Sichbaren entwachsen und hat fast alle Bereiche des elektromagnetischen Spektrums für sich dienstbar gemacht. Im sogenannten nahen und mittleren Infrarot (Wellenlängen zwischen 1-30 μm) sowie im Millimeter- und Radio-Regime (Wellenlängen zwischen 1 mm und 10 m) ist die Erdatmosphäre relativ gut durchlässig für elektromagnetische Signale oder hat zumindest eine Vielzahl von spektral begrenzten Transmissionsfenstern, die astronomische Beobachtungen zumindest von höheren Bergen aus möglich machen. Allerdings ist das sogenannte Ferne Infrarot (FIR, 30-300 μm Wellenlänge) von der Erde aus fast völlig unzugänglich für astronomische Beobachtungen. Selbst für die besten Beobachtungsplätze der Erde bleibt die atmosphärische Transmission durch die immense Wasserdampf- Absorption auf ein absolutes Minimum beschränkt. Jedoch erlaubt uns das FIR Zugang zu Informationen, die sehr nützlich sind für die astrophysikalische Forschung und komplementär zu anderen Wellenlängen-Bereichen.

  20. Aufnahme, Analyse und Visualisierung von Bewegungen nativer Herzklappen in-vitro

    NASA Astrophysics Data System (ADS)

    Weiß, Oliver; Friedl, Sven; Kondruweit, Markus; Wittenberg, Thomas

    Die hohe Zahl an Transplantationen von Herzklappen und viele nötige Re-Operationen machen eine detaillierte Analyse der Strömungen und Klappenbewegungen klinisch interessant. Ein neuer Ansatz ist hierbei der Einsatz von Hochgeschwindigkeitskameras um Bewegungsabl äufe der Herzklappen beobachten und auswerten zu können. Die hohen Datenraten erfordern allerdings eine möglichst automatisierte Analyse und möglichst komprimierte Darstellung des Schwingungsverhaltens. In dieser Arbeit wird ein Ansatz vorgestellt, bei dem Bewegungen nativer Herzklappen in-vitro aufgenommen, analysiert und kompakt visualisiert werden.

  1. Hinderniserkennung und -verfolgung mit einer PMD-kamera im automobil

    NASA Astrophysics Data System (ADS)

    Schamm, Thomas; Vacek, Stefan; Natroshvilli, Koba; Marius Zöllner, J.; Dillmann, Rüdiger

    Die Detektion von Hindernissen vor dem Automobil ist eine Hauptanforderung an moderne Fahrerassistenzsysteme (FAS). In dieser Arbeit wird ein System vorgestellt, das mit Hilfe einer PMDKamera (Photomischdetektor) Hindernisse auf der Fahrspur erkennt und deren relevante Parameter bestimmt. Durch die PMD-Kamera werden zunächst 3D-Tiefenbilder der Fahrzeugumwelt generiert. Nach einem initialen Filterprozess werden im Tiefenbild mit Hilfe eines Bereichswachstumsverfahrens Hindernisse gesucht. Zur Stabilisierung des Verfahrens und zur Parameterberechnung wird ein Kaiman Filter eingesetzt. Das Ergebnis ist eine Liste aller Hindernisse im Fahrbereich des Automobils.

  2. Terror mit Atomwaffen: reale Gefahr? Nukleare und Radiologische Waffen

    NASA Astrophysics Data System (ADS)

    Harigel, Gert G.

    2006-01-01

    Können Terroristen sich nukleare Massenvernichtungswaffen beschaffen? Dazu müssten sie ausreichende Mengen an waffenfähigem, spaltbarem Material stehlen. Selbst der Bau einer primitiven Atombombe erfordert einen hohen technischen Aufwand und Spezialisten. Wahrscheinlicher ist deshalb der Diebstahl einer kleinen taktischen Kernwaffe. Alternativ könnten Terroristen sich radioaktives Material aus zivilen Quellen beschaffen und daraus eine Schmutzige Bombe bauen. Eine solche radiologische Waffe wäre keine echte Massenvernichtungswaffe, doch ihre psychologische Wirkung könnte stark sein. Das macht sie für Terroristen attraktiv, weswegen diese Gefahr ernst genommen werden muss.

  3. Reflexionseigenschaften von Windenergieanlagen im Funkfeld von Funknavigations- und Radarsystemen

    NASA Astrophysics Data System (ADS)

    Sandmann, S.; Divanbeigi, S.; Garbe, H.

    2015-11-01

    Die hier behandelte Untersuchung befasst sich mit den Störungen des elektrischen Feldes einer Doppler Very High Frequency Omnidirectional Radio Range Navigationsanlage (DVOR) in der Gegenwart von Windenergieanlagen (WEA). Hierfür wird die Feldstärke auf 25 konzentrischen Kreisbahnen, sog. Orbit Flights verschiedener Höhen und mit verschiedenen Radien rund um die DVOR-Anlage numerisch simuliert. Insbesondere werden die Einflüsse diverser Parameter der WEA wie deren Anzahl, Position, Rotorwinkel, Turmhöhe und Rotordurchmesser auf die Feldverteilung herausgestellt, sowie die Anwendbarkeit der Simulationsmethode Physical Optics (PO) durch Vergleich der Simulationsergebnisse mit denen der Multi Level Fast Multipol Method (MLFMM) untersucht.

  4. Diorganostyrylzinndiorganophosphine und Ihre Tricarbonylnickelkomplexe (Diorganostyryltin Phosphines and its Tricarbonylnickel Complexes).

    DTIC Science & Technology

    1979-12-03

    Umkristallisieren aus Pentan/Benzol/Toluol gereinigt werden konnen; IVb zeigt bereits ab 0°C Polym erisationserschei- nungen. Vb und VIb werden als heligelbe...einem Rar.ger Engeneering M6ssbauer Spectrometer benutzt wurde. in C 6 D 6c) die Ha lbwertsbreiten wurden als glei~h vorausgesetzt , um dos Si gnal als

  5. Increasing Pragmatic Awareness: Die Vagheit der Sprache "und so"

    ERIC Educational Resources Information Center

    Overstreet, Maryann; Tran, Jennie; Zietze, Sylvia

    2006-01-01

    This article presents a description of some pragmatic expressions ("oder so," "und so," "oder wie") rarely found in textbooks, but common in everyday conversation. Though often treated as vague or superfluous, these expressions perform important functions in interpersonal communication. Focusing on these easily identifiable phrases can help…

  6. Denken in Wertschöpfung und Verschwendung

    NASA Astrophysics Data System (ADS)

    Bergmann, Lars; Lacker, Michael

    Eine Antwort auf die Frage welche Arbeitsschritte, Aktivitäten und Prozesse als wertschöpfend betrachtet werden können, erhält man durch die Überlegung, ob der Kunde bereit ist dafür zu zahlen. Kunden sind sicher bereit dafür zu zahlen, dass z.B. die Räder an ihrem neuen PKW sicher montiert sind. Die im Unternehmen notwendigen logistischen Prozesse, die die Räder zu ihrem Montageort transportieren, sind aus Sicht des Kunden dagegen mit keinem Wert verbunden. Insofern ist er nicht bereit dafür zu zahlen und sämtliche internen logistischen Aktivitäten sind entsprechend nicht wertschöpfend. Verschwendung bzw. nicht wertschöpfende Arbeit umfasst alle Aktivitäten, Tätigkeiten und Prozesse, die Zeit, Ressourcen und/oder Raum kosten, aber nicht zur Erfüllung der Kundenanforderungen beitragen. Verschwendung ist damit der Teil der Arbeit, für den der Kunde nicht zahlt, z.B. den internen Transport von Bauteilen zum Montageort.

  7. Kraft-Wärmekopplung und Blockheiz-Kraftwerke BHKW

    NASA Astrophysics Data System (ADS)

    Zahoransky, Richard; Allelein, Hans-Josef; Bollin, Elmar; Oehler, Helmut; Schelling, Udo

    Die thermischen Wirkungsgrade von Kraftwerken zur Stromerzeugung sind relativ gering. Beispielsweise erreichen moderne Kohlekraftwerke heute bis etwa 45 %, Gasturbinen maximal 40 % und Diesel-Motoren nicht über 50 %. Kombinations-Kraftwerke, Gas- und Dampfturbinen-Prozesse können an die 60 % thermischer Wirkungsgrad bei der Umwandlung der zugeführten Wärme in mechanische bzw. elektrische Energie erzielen. Ein ähnlich hoher Wert wird in Zukunft von den Brennstoffzellen erwartet. Der nicht in Arbeit umgewandelte Anteil der zugeführten Wärme fällt als Abwärme an und geht ungenutzt in die Umgebung. Ein Teil dieser Abwärme lässt sich durch entsprechende Installationen bei allen Kraftwerksprozessen zur Wassererwärmung oder zur Dampferzeugung für industrielle Zwecke nutzen. Für Heizzwecke genügt eine Temperatur der Abwärme von 60 %C bis 80 %C, während die Erzeugung von Industriedampf deutlich höhere Temperaturen voraussetzt.

  8. Physik gestern und heute: Fragwürdiges beim Millikan-Versuch

    NASA Astrophysics Data System (ADS)

    Heering, Peter

    2006-09-01

    Robert A. Millikan erhielt 1923 als erster amerikanischer Physiker den Nobelpreis für Physik. Geehrt wurde er für seine Präzisionsmessungen zum Photoeffekt und zur experimentellen Bestimmung der elektrischen Elementarladung. Millikans Experimente zur Elementarladung sind auch heute noch ein Standardthema im schulischen Physikunterricht, gleichzeitig werfen sie aber eine Reihe von wissenschaftstheoretischen und ethisch relevanten Fragen auf.

  9. Modellierung und Simulation des Substrat-Rauschens in integrierten RF CMOS-Schaltungen

    NASA Astrophysics Data System (ADS)

    Lin, L.; Xiong, J.; Mathis, W.

    2009-05-01

    Im integrierten CMOS-Schaltungsentwurf kann das Substrat-Rauschen, das vom digitalen Teil entsteht, die Funktionalität des analogen Teils stark beeinflussen. Es wird daher immer wichtiger, das Substrat als ein Medium der Rauschen-Propagation genau zu modellieren. Im vorliegenden Artikel wird ein auf der Finite Elemente Methode (FEM) und Modellordnungsreduktion (MOR) basiertes Modellierungsverfahren zur Admittanzen-Extraktion im Halbleitersubstrat vorgestellt. Nach der Diskretisierung mit FEM wird das Substrat im Allgemeinen als ein resistives/kapazitives Netz angesehen. Durch Bestimmung der Admittanz-Matrix und MOR ist es möglich ein äquivalentes Dreipol-Modell zwischen digitalem und analogem Teil über das Substrat zu bilden. Das Ergebnis der Modellierung wird dargestellt und mit numerischer Simulation des Substrat-Rauschens verglichen. Die Modellierung ermöglicht es, die Einflüsse des Substrat-Rauschens im Schaltungsentwurf zu berücksichtigen und so bestehende CMOS-Schaltungsarchitekturen zu optimieren.

  10. Variationeller Ansatz für eine integrierte Segmentierung und nicht-lineare Registrierung

    NASA Astrophysics Data System (ADS)

    Schmidt-Richberg, Alexander; Ehrhardt, Jan; Handels, Heinz

    Vierdimensionale tomographische Bilddaten ermöglichen neuartige Therapie- und Diagnoseverfahren in der medizinischen Praxis. Voraussetzung dafür sind oft die räumlich-zeitliche Segmentierung anatomischer Strukturen in den 4D- Daten und die Bestimmung ihrer dynamischen Eigenschaften durch Schätzung der 3D-Bewegungsfelder mittels nicht-linearer Registrierungsverfahren. In dieser Arbeit wird ein Ansatz vorgestellt, mit dem sich Level-Set-Segmentierung und diffusive, nicht-lineare Registrierung unter Berücksichtigung ihrer wechelseitigen Abhängigkeiten integriert lösen lassen. Die Aufgabe wird als Energieminimierung formuliert und ein variationelles Lösungsverfahren angegeben. Anschließend wird der Ansatz an Phantom- und CT-Patientendaten am Beispiel der Leber validiert.

  11. Kernschmelze Der nachhaltige Einfluss von Nuklearwaffen auf Politik und Wirtschaft

    NASA Astrophysics Data System (ADS)

    Greiner, Bernd

    "Was sollen wir von einer Kultur halten, der die Ethik stets als wesentliches Element des menschlichen Lebens galt, die aber - außer in fachlicher oder spieltheoretischer Terminologie - nicht in der Lage war, über die Möglichkeit zu sprechen, nahezu alle Menschen zu töten?" Der Fragesteller gehört zu den berühmtesten Physikern des 20. Jahrhunderts und zu den nach wie vor Umstrittensten. über ihn wurde in den 1960er Jahren ein international viel beachtetes Theaterstück geschrieben, vor wenigen Jahren gar eine Oper.

  12. Was leistet ein Sportler? Kraft, Leistung und Energie im Muskel

    NASA Astrophysics Data System (ADS)

    Thaller, Sigrid; Mathelitsch, Leopold

    2006-01-01

    Der Leistungsbegriff ist im Sport weiter gefasst als in der Physik. In beiden Fällen liegt der Fokus jedoch auf einer pro Zeiteinheit erfolgten Energieumsetzung. Allerdings gibt die rein physikalische Leistung nicht immer Auskunft über den Energieumsatz der Muskeln. Die Muskelkraft hängt von der Kontraktionsgeschwindigkeit des Muskels ab. Ein Muskel verhält sich also anders als eine Feder. Für den Hochleistungssport müssen die Energieumsätze der Muskeln durch spezielle Trainings- und Nahrungsprogramme optimiert werden.

  13. Integrierte Segmentierung und Trajektorienberechnung mittels diffeomorpher Registrierung in räumlich-zeitlichen CT-Bildfolgen

    NASA Astrophysics Data System (ADS)

    Schmidt-Richberg, Alexander; Ehrhardt, Jan; Werner, René; Handels, Heinz

    Verfahren zur integrierten Segmentierung und Registrierung von 4D-Bilddaten ermöglichen die Berücksichtigung der gegenseitigen Abhängigkeiten beider Komponenten. Bestehende Ansätze konzentrieren sich dabei meist auf die Betrachtung zweier 3D-Bilder und lassen sich nicht direkt auf vollständige Bildfolgen übertragen. In dieser Arbeit wird ein Verfahren vorgestellt, in dem ein diffeomorpher Registrierungsansatz verwendet wird, um eine integrierte Berechnung von Segmentierungen und 3D-Voxeltrajektorien in 4D-Daten zu ermöglichen.

  14. Der Kalte Krieg in der Peripherie Griechische Physiker und Atomenergie nach dem Zweiten Weltkrieg

    NASA Astrophysics Data System (ADS)

    Vlahakis, George N.

    Die vorliegende Arbeit analysiert Ansichten griechischer Physiker zur Atomenergie und deren mögliche Anwendung nach dem Zweiten Weltkrieg, insbesondere während des Kalten Kriegs. Einerseits werden Ansichten von Physik- Professoren griechischer Universitäten präsentiert - beispielsweise von Dimitrios Hondros, der Student von Arnold Sommerfeld und Mitarbeiter von Peter Debye in München war, und andererseits wird die Politik der griechischen Regierung für die Etablierung eines Forschungsinstitutes diskutiert, das der Entwicklung der Atomenergie dienen sollte; ebenfalls wird eine öffentliche Meinungsumfrage zu diesen Thema, die in den Tageszeitungen der damaligen Zeit präsentiert wurde, diskutiert.

  15. Jahre Entwicklung der Instandhaltung - von der ausfallorientierten Instandhaltung zum gemeinsamen TPM und RCM

    NASA Astrophysics Data System (ADS)

    Iske, Friedhelm

    Zur Einleitung meines Beitrages möchte ich von einem Gespräch mit einem Mitarbeiter berichten, das ich als junger Vorgesetzter einer Instandhaltungsgruppe 1988 führte. Der engagierte Mitarbeiter feierte damals sein vierzigjähriges Dienstjubiläum und war stolz auf das von ihm Geleistete sowie auf den besonderen Einsatz seiner Altersgruppe, die nach dem Zweiten Weltkrieg das Werk wieder aufgebaut hatte. Auf meine Frage, was denn damals die erste Aufgabe in der Firma war, bekam ich kurz und knapp und mit einer Selbstverständlichkeit die selbstbewusste Antwort: "Unser Pferd füttern und mit dem Pferd die innerbetrieblichen Transporte erledigen“. Als junger, technisch orientierter Vorgesetzter war ich über diese Antwort sehr überrascht. Gedanklich weit entfernt war die Vorstellung, dass in der Vergangenheit Transporte mit einem Pferd erledigt wurden.

  16. Modellgestützte Fehlererkennung und Diagnose für Common-Rail-Einspritzsysteme

    NASA Astrophysics Data System (ADS)

    Clever, Sebastian

    Moderne Pkw-Dieselmotoren sind mit verschiedensten komplexen mechatronischen Komponenten ausgestattet. So kommen neben Abgasrückführsystemen zur Minderung der Stickoxidemissionen und Turboladern zur Steigerung der Leistungsdichte insbesondere elektronisch gesteuerte Mehrfach-Einspritzsysteme zum Einsatz. Deshalb erhöht sich die Bedeutung einer umfassenden Fehlererkennung und Diagnose, zusätzlich zu den bekannten OBD- und EOBD-Vorgaben, im Rahmen steigender Anforderungen an die Zuverlässigkeit und Verfügbarkeit. Um diese Anforderungen zu erfüllen, bieten sich modellbasierte Verfahren an. Ihr Stand in verschiedenen Gebieten wird zum Beispiel in [1-6] beschrieben. Mit dem Einsatz modellgestützter Fehlererkennungsverfahren bei Verbrennungsmotoren beschäftigen sich beispielsweise [7-18].

  17. Zur ethischen Dimension von Renaturierungsökologie und Ökosystemrenaturierung

    NASA Astrophysics Data System (ADS)

    Ott, Konrad

    Die wissenschaftlich angeleitete Ökosystemrena-turierung kann mittlerweile als eine etablierte Praxis im Bereich des Naturschutzes gelten. Diese Praxis bezieht sich notwendigerweise auf Ziele und Werte und weist damit auch eine naturethische Dimension auf. Daher hat diese Praxis die Aufmerksamkeit auch von Sozialwissenschaftlern und Ethikern auf sich gezogen. Dieses Kapitel geht der Frage nach, wie sich die naturethische Dimension der Ökosystemrenaturierung analysieren und inhaltlich bestimmen lässt. Hierzu erweist sich auch die Auseinandersetzung mit Philosophen als hilfreich, die der Ökosystemrenaturierung ein technizistisches Naturverständnis vorgeworfen haben. Am Ende des Kapitels wird ein in sich gestuftes mögliches naturethisches Selbstverständnis der Ökosystemrenaturierung diskutiert, das den an dieser Praxis Beteiligten Freiheitsgrade der Positionierung belässt.

  18. Toolmanagement - Werkzeuge und Prozesse als Schlüssel für eine effiziente Produktion

    NASA Astrophysics Data System (ADS)

    Enßle, Magnus

    In Bezug auf die Fertigungskosten nehmen die Werkzeugkosten mit 3% einen sehr kleinen und daher vermeintlich unwichtigen Posten ein. HoheKosten ergeben sich aber meist indirekt durch Maschinenstillstandszeiten wegen fehlender oder falscher Werkzeuge, wegen ineffektiven Rüstvorgängen, umständlicher Werkzeuglogistik, unnötig hoher Bestände, unabgestimmter Abläufe, nicht aktueller Fertigungsunterlagen sowie mangelhafter Informationsflüsse zwischen Planung, Vorbereitung und Ausführung in der Fertigung [1].

  19. Design und Analyse elektrisch kleiner Antennen für den Einsatz in UHF RFID Transpondern

    NASA Astrophysics Data System (ADS)

    Herschmann, R.; Camp, M.; Eul, H.

    2006-09-01

    RFID Systeme werden seit Anfang der neunziger Jahre mit stetig zunehmender Verbreitung im Bereich der automatischen Produktidentifikation, der Diebstahlsicherung (EAS, Electronic Article Surveillance) und für automatische Zutrittskontrollsysteme eingesetzt. Objekte werden hierzu mit einem Transponder ausgestattet, der aus einer Antenne und einem Chip auf einem Trägermaterial besteht. Von großem Interesse ist die Entwicklung und Optimierung von passiven Transpondern für den Einsatz in UHF RFID Systemen. Diese Transponder beziehen die Energie zum Betrieb des Chips aus dem elektromagnetischen Feld einer Schreib-Leseeinheit. Hierfür ist neben der Anpassung der Eingangsimpedanz der Antenne an die Chipimpedanz auch eine möglichst hohe Bandbreite der Antennen wünschenswert, um die Funktion des Transponders bei Schwankungen der Chipimpedanz und variablen Umgebungsparametern zu gewährleisten. Der aus Platzgründen notwendige Einsatz elektrisch kleiner Antennen bedingt eine möglichst optimale Ausnutzung der zur Verfügung stehenden Fläche auf dem Trägermaterial zur Aufnahme der Antenne. Die vorliegende Arbeit beschreibt ein Verfahren zur Analyse und Synthese neuartiger Antennendesigns auf der Basis parametrisierter meandrierter, spiralförmiger und logarithmisch periodischer Dipole.

  20. Schönheit und andere Provokationen - Eine neue evolutionsbiologische Theorie der Kunst

    NASA Astrophysics Data System (ADS)

    Junker, Thomas

    Die Evolution hat viele spektakuläre Phänomene hervorgebracht - von der Eleganz des Vogelflugs über die gigantischen Körper der Dinosaurier und die farbenprächtige Vielfalt der Korallenriffe bis hin zu ihrem jüngsten Geniestreich - der menschlichen Kunst. Die schönen Künste - Malerei, Bildhauerei und Architektur, Theater, Tanz, Oper und Filmkunst, Musik und Literatur - Produkte der Evolution? Diese Vorstellung mutet vielen Menschen fremd an, aber wie könnte es anders sein? Denn wenn Charles Darwin recht hat, dann sind nicht nur die körperlichen Merkmale der Menschen als Antworten auf die Erfordernisse des Lebens entstanden, sondern auch ihre geistigen Fähigkeiten und Verhaltensweisen. Im Jahr 1859 hatte er auf den letzten Seiten seines berühmten Buches über die Entstehung der Arten eine kühne Prophezeiung gemacht: Durch die Evolutionstheorie werde es "zu einer bemerkenswerten Revolution in der Naturwissenschaft kommen […]. Die Psychologie wird auf die neue Grundlage gestellt, dass jede geistige Kraft und Fähigkeit notwendigerweise durch graduelle Übergänge erworben wird“ (Darwin 1859, S. 484, 488; Junker 2008).

  1. Counting the atoms in a 28Si crystal for a new kilogram definition

    NASA Astrophysics Data System (ADS)

    Andreas, B.; Azuma, Y.; Bartl, G.; Becker, P.; Bettin, H.; Borys, M.; Busch, I.; Fuchs, P.; Fujii, K.; Fujimoto, H.; Kessler, E.; Krumrey, M.; Kuetgens, U.; Kuramoto, N.; Mana, G.; Massa, E.; Mizushima, S.; Nicolaus, A.; Picard, A.; Pramann, A.; Rienitz, O.; Schiel, D.; Valkiers, S.; Waseda, A.; Zakel, S.

    2011-04-01

    This paper concerns an international research project aimed at determining the Avogadro constant by counting the atoms in an isotopically enriched silicon crystal. The counting procedure was based on the measurement of the molar volume and the volume of an atom in two 1 kg crystal spheres. The novelty was the use of isotope dilution mass spectrometry as a new and very accurate method for the determination of the molar mass of enriched silicon. Because of an unexpected metallic contamination of the sphere surfaces, the relative measurement uncertainty, 3 × 10-8 NA, is larger by a factor 1.5 than that targeted. The measured value of the Avogadro constant, NA = 6.022 140 82(18) × 1023 mol-1, is the most accurate input datum for the kilogram redefinition and differs by 16 × 10-8 NA from the CODATA 2006 adjusted value. This value is midway between the NIST and NPL watt-balance values.

  2. The Correlation of the N{sub A} Measurements by Counting {sup 28}Si Atoms

    SciTech Connect

    Mana, G. Massa, E.; Sasso, C. P.; Stock, M.; Fujii, K.; Kuramoto, N.; Mizushima, S.; Narukawa, T.; Borys, M.; Busch, I.; Nicolaus, A.; Pramann, A.

    2015-09-15

    An additional value of the Avogadro constant was obtained by counting the atoms in isotopically enriched Si spheres. With respect to the previous determination, the spheres were etched and repolished to eliminate metal contaminations and to improve the roundness. In addition, all the input quantities—molar mass, lattice parameter, mass, and volume—were remeasured aiming at a smaller uncertainty. In order to make the values given in Andreas et al. [Metrologia 48, S1 (2011)] and Azuma et al. [Metrologia 52, 360 (2015)] usable for a least squares adjustment, we report about the estimate of their correlation.

  3. The new kilogram definition based on counting the atoms in a 28Si crystal

    NASA Astrophysics Data System (ADS)

    Becker, Peter

    2012-11-01

    The kilogram is the only unit of measure still defined by a physical object. Now, a marathon effort to tie the kilogram to a constant of nature is nearing the finish line. This paper concerns an international research project aimed at determining the Avogadro constant by counting the atoms in an isotopically enriched silicon crystal. The counting procedure was based on the measurement of the molar volume and the volume of an atom in two 1 kg crystal spheres. The novelty was the use of isotope dilution mass spectrometry as a new and very accurate method for the determination of the molar mass of enriched silicon. Because of an unexpected metallic contamination of the sphere surfaces, the relative measurement uncertainty, ? , results were larger by a factor 1.5 than that targeted. The measured value of the Avogadro constant, ? mol-1 is the most accurate input datum for the kilogram redefinition and differs only by ? from the CODATA 2010 adjusted value. This value is midway between the watt-balance values.

  4. The Correlation of the NA Measurements by Counting 28Si Atoms

    NASA Astrophysics Data System (ADS)

    Mana, G.; Massa, E.; Sasso, C. P.; Stock, M.; Fujii, K.; Kuramoto, N.; Mizushima, S.; Narukawa, T.; Borys, M.; Busch, I.; Nicolaus, A.; Pramann, A.

    2015-09-01

    An additional value of the Avogadro constant was obtained by counting the atoms in isotopically enriched Si spheres. With respect to the previous determination, the spheres were etched and repolished to eliminate metal contaminations and to improve the roundness. In addition, all the input quantities—molar mass, lattice parameter, mass, and volume—were remeasured aiming at a smaller uncertainty. In order to make the values given in Andreas et al. [Metrologia 48, S1 (2011)] and Azuma et al. [Metrologia 52, 360 (2015)] usable for a least squares adjustment, we report about the estimate of their correlation.

  5. Fragwuerdige Luxussteuern: Statusstreben und Demonstratives Konsumverhalten in der Geschichte Oekonomischen Denkens (Questionable Luxury Taxes: Status Seeking and Conspicuous Consumption in the History of Economic Thought)

    DTIC Science & Technology

    2008-05-01

    England immer mehr, und der Markt ffir Luxusgiiter und Mode begann zu florieren. Die Kommerzialisierung des Handels im England des 18. Jahrhunderts...der insbesondere Hirsch (1976) in seinen Social Limits to Growth wieder Nachdruck verleihen sollte. Siehe hierzu Abschnitt 2.9. 5 auf seinen...klassischen Schule ibertriebenes statusbedingtes Konsumverhalten als social waste an und pladiert fdr eine Lenkung statusbedingten Konsumverhaltens in

  6. Die Tabellen von Ulugh Beg. Die Sternkataloge des Ptolemäus, Ulugh Beg und Tycho Brahe im Vergleich

    NASA Astrophysics Data System (ADS)

    Schwan, Heiner

    2002-09-01

    Im 15. Jahrhundert schuf Ulugh Beg, der Herrscher von Samarkand (1394 - 1449), ein wichtiges Tabellenwerk. Das Kernstück dieses Werks (Zij Ulugh Beg, "Tabellen Ulugh Begs") ist ein Katalog mit 1018 Sternen, ihren Helligkeiten und Positionen. In diesem Bericht werden die Zij Ulugh Beg mit den großen Katalogen von Ptolemäus und Tycho Brahe verglichen.

  7. Die Deutsche Statistische Gesellschaft in der Weimarer Republik und während der Nazidiktatur

    NASA Astrophysics Data System (ADS)

    Wilke, Jürgen

    Nach anfänglichen Schwierigkeiten durch den 1. Weltkrieg erlangte die Deutsche Statistische Gesellschaft (DStatG) unter dem renommierten Statistiker und Vorsitzenden der DStatG, Friedrich Zahn, durch eine Vielzahl von Aktivitäten hohes Ansehen. Es gab Bestrebungen, Statistiker aus allen Arbeitsfeldern der Statistik in die DStatG zu integrieren, wobei die "Mathematische Statistik" nur zögerlich akzeptiert wurde (Konjunkturforschung, Zeitreihenanalyse). Nach der Machtübernahme 1933 durch Adolf Hitler geriet die DStatG in das Fahrwasser nationalsozialistischer Ideologie und Politik (Führerprinzip, Gleichschaltung des Vereinswesens). Damit war eine personelle Umstrukturierung in der DStatG verbunden. Politisch Missliebige und rassisch Verfolgte mussten die DStatG verlassen (Bernstein, Freudenberg, Gumbel u.a.). Unter den Statistikern gab es alle Abstufungen im Verhalten zum Regime von Ablehnung und zwangsweiser Anpassung über bereitwilliges Mitläufertum bis zu bewusster Täterschaft. Besonders die Bevölkerungsstatistik wurde durch die NS- Rassenpolitik auf lange Sicht diskreditiert. Im Rahmen von Wirtschaftsplanung und Aufrüstung wurden neue zukunftsträchtige statistische Modelle (Grünig, Bramstedt, Leisse) entwickelt.

  8. Missbrauchspotential von Verzeichnisdienst-Metadaten in LDAP-basierten System- und Benutzerverwaltungen

    NASA Astrophysics Data System (ADS)

    Pluta, Daniel

    Metadaten stellen Zusatzinformationen über elektronisch gespeicherte Kerninformationen zur Verfügung. Sie ergänzen die eigentliche Hauptinformation um nützliche Details. In vielen Bereichen werden Metadaten gespeichert und stehen zur Auswertung zur Verfügung. Alle IT-nahen Systeme, angefangen im Konsumerbereich (z.B. digitale Kameras) bis hin zu unternehmenskritischen Applikationen führen im Hintergrund Metadaten - parallel zu den eigentlichen Hauptdaten. Metadaten im Allgemeinen sind per se als neutral, d.h. weder positiv noch negativ, zu bewerten. So wirken sich diese häufig positiv auf das Finden und Sortieren von digitalen Dokumenten aus. Negativ treten Metadaten eigentlich immer nur dann in Erscheinung, sobald diese ursprünglich zusätzlichen und nützlichen (und daher im Gegensatz zu den Hauptdaten nicht besonders beachteten bzw. geschützten) Informationen entgegen ihrer Bestimmung, zweckentfremdet werden. Auch Verzeichnisdienste verfügen über solche nützlichen Metadaten zu den jeweils in ihnen gespeicherten Inhalten. Ob, und wenn ja wie weit diese nützlichen Inhalte auch ein Risiko darstellen können wird im Rahmen dieses Artikels anhand eines konkreten Szenarios aus dem Umfeld des Systemmanagements gezeigt.

  9. Molekulare Methoden zum Nachweis, zur Quantifizierung und zum Monitoring der Mykotoxinbildung lebensmittelrelevanter Pilze

    NASA Astrophysics Data System (ADS)

    Geisen, Rolf

    Schimmelpilze kommen ubiquitär vor und spielen besonders bei pflanzlichen Lebensmitteln und Rohprodukten eine besondere Rolle als Verderbsorganismen. Es wird geschätzt, dass 20-25 % der jährlichen Produktion an pflanzlichen Produkten durch Schimmelpilze verdorben werden (Smith et al., 1994). Viele der lebensmittelrelevanten Schimmelpilze sind zudem in der Lage, Mykotoxine, toxische Sekundärmetabolite, zu bilden, was das Ausmaß des Problems deutlich macht. Die wichtigsten mykotoxinbildenden Spezies gehören zu den Fusarien (Trichothecene, Fumonisine, Zearalenon), Aspergillen (Aflatoxin, Ochratoxin, Cyclopiazonsäure) und Penicillien (Patulin, Ochratoxin). Für viele Mykotoxine, wie die Aflatoxine, Ochratoxin, Fumonisine und Trichothecene sind Grenzwerte erlassen worden, die die Verkehrsfähigkeit betroffener Produkte regeln. Die Einhaltung der Grenzwerte kann sehr genau durch offizielle chemisch-analytische Methoden, wie HPLC, GC-MS etc. kontrolliert werden. Diese analytischen Methoden sind aber für die Anwendung eines HACCP-Ansatzes zur Kontrolle der Mykotoxinbildung nur bedingt geeignet, da sie Endpunktkontrollen darstellen und nur das über eine längere Zeit gebildete Mykotoxin bestimmen. Sie sagen daher nichts über die biologischen Bedingungen zur Zeit der Bildung durch den Pilz aus.

  10. Planeten beobachten. Praktische Anleitung für Amateurbeobachter und solche, die es werden wollen.

    NASA Astrophysics Data System (ADS)

    Roth, G. D.

    Contents: 1. Amateurastronomie und Planetenbeobachtung (H.-J. Mettig, G. D. Roth). 2. Die visuelle Beobachtung (G. D. Roth). 3. Mond- und Planetenphotographie (B. Koch). 4. Die CCD-Bildbearbeitung (R. A. Hillebrecht). 5. Tabellen zur Ermittlung der Belichtungszeiten für Mond- und Planetenaufnahmen (W. Gruschel). 6. Die lichtelektrische Beobachtung (G. D. Roth). 7. Die Objekte in Einzeldarstellungen: Merkur (D. Niechoy); Venus (D. Niechoy); Erdmond (G. D. Roth); Mars (C. M. Schambeck); Kleine Planeten (M. Hoffmann, G. D. Roth, J. Meeus); Jupiter (H.-J. Mettig, R. C. Stoyan, A. Nikolai, C. Kowalec, G. Hahn); Saturn (R. C. Stoyan, G. Hahn, H.-J. Mettig); Uranus (R. C. Stoyan); Neptun (R. C. Stoyan); Pluto (R. C. Stoyan). 8. Adressen, Literaturhinweise, Register.

  11. Technische Systeme für den Herzersatz und die Herzunterstützung

    NASA Astrophysics Data System (ADS)

    Schöb, Reto; Loree, Howard M.

    Herzkrankheiten verursachen allein in den Vereinigten Staaten jährlich mehr als 700’000 Todesfälle. Ungefähr 3 Millionen Patienten in den U.S.A. leiden gemäss der American Heart Association (AHA) und dem National Heart, Lung and Blood Institute (NHLBI) an kongestivem Herzversagen (Congestive Heart Failure, CHF), welches eine chronische, sehr entkräftende und degenerative Krankheit ist: Das Herz ist dabei unfähig, hinreichend Blut zu den Organen des Körpers zu pumpen. Über 400’000 Fälle von CHF werden jedes Jahr diagnostiziert. Ähnliche Zahlen werden für Europa und Japan zusammen geschätzt. Basierend auf Daten vom AHA und NHLBI beträgt die fünfjährige Überlebensrate für CHF-Patienten lediglich etwa 50% [1]. 70’000-120’000 dieser Patienten könnten von einer Herzverpflanzung profitieren. 1999 wurden in den USA aber nur 2185 Herztransplantationen durchgeführt während die Warteliste über 4000 Patienten beträgt [2]. Ein akuter Mangel an Spenderherzen und die enormen Kosten (250’000-400’000 USD pro Patient) sind die begrenzenden Faktoren für Herztransplantationen [3]. Dies bedeutet, dass eine riesige Anzahl von Patienten durch ein zuverlässiges und verschleissfreies, nichtthrombotisches, total implantierbares, künstliches Herz gerettet werden könnten. Bis heute jedoch kein derartiges Implantat kommerziell verfügbar.

  12. Dynamische Satzgenerierung und Sprachausgabe für einen mobilen Serviceroboter

    NASA Astrophysics Data System (ADS)

    Parlitz, Christopher; Amann, Bernd; Hägele, Martin

    Die vorliegende Arbeit befasst sich mit der Entwicklung einer Sprachausgabe für ein mobiles Robotersystem. Dazu wurde zum einen ein auf die Anwendung zugeschittenes Text-To-Speech Verfahren und zum anderen eine Grammatik, die eine dynamische Satzgenerierung ermöglicht, implementiert. Die Verfahren arbeiten unabhängig voneinander und können daher auch gegen andere Komponenten ausgetauscht werden. Die Programme wurden als Client-Server Applikationen programmiert, um möglichst flexibel die Sprachausgabe einsetzen zu können.

  13. Biologie statt Philosophie? Evolutionäre Kulturerklärungen und ihre Grenzen

    NASA Astrophysics Data System (ADS)

    Illies, Christian

    Vor über siebzig Jahren fand man in einer Höhle nahe Hohlenstein-Stadel, im heutigen Baden-Württemberg, eine Frau, die keiner bekannten Spezies und nicht einmal eindeutig den Hominiden zugeordnet werden konnte. Wegen ihres Aussehens wurde sie schon bald als "Löwenfrau“ bekannt (unterdessen wird sie als "Löwenmensch“ bezeichnet, da die in solchen Fragen Klarheit schaffenden Geschlechtsteile bei der Figur fehlen und in Zeiten von gender mainstreaming derartige Festlegungen gerne vermieden werden), denn sie hatte eine menschlich-aufrechte, unbehaarte Gestalt mit weiblichen Rundungen, aber zugleich eine Mähne, sowie Augen, Ohren und Schnauze eines Löwen. Eine sehr weitläufige Verwandte des Minotaurus, so schien es, und doch wesentlich älter als alle Bewohner des Olymps, denn vermutlich wurde die knapp 30 cm große Skulptur bereits in der Altsteinzeit vor etwa 32.000 Jahren aus Mammut-Elfenbein geschnitzt. Wir wissen nicht, ob sie kultischen Zwecken diente oder ein Kind mit ihr spielte, ob sie als Glücksbringer für die Jagd oder als Schamanin mit Löwenmaske verehrt und gefürchtet wurde. Aber die Löwenfrau legt nahe, dass der Mensch schon im Morgendämmern seiner Kultur über die eigene Nähe, aber auch Distanz zum Tier nachgedacht haben muss. Die Frage nach der menschlichen Selbstverortung begegnet uns in dieser Figur, und sie bestimmt viele Zeugnisse menschlichen Nachdenkens, welche uns die Altertumswissenschaften vorlegen. Mit dem Begriff "animal rationale“, wie er unter Bezug auf Aristoteles geprägt wurde, findet sie schließlich ihre klassische, für das Abendland lange Zeit maßgebliche Antwort: Der Mensch als Tier, dessen spezifisches Merkmal die Vernunftbegabtheit ist, die ihn zugleich von allen anderen Tieren abgrenzt und über sie stellt. Aber wo genau verläuft die Grenze? Und wie kann der Mensch beides zugleich sein? Die aristotelische Definition beantwortet diese Fragen nach der Doppelnatur nicht, sondern erhebt das offene R

  14. Vom Referat bis zur Examensarbeit: Naturwissenschaftliche Texte perfekt verfassen und gestalten

    NASA Astrophysics Data System (ADS)

    Kremer, Bruno P.

    Welches Thema eignet sich für mein Referat oder meine Seminararbeit? Wie sammle ich Stoff? Wie gliedere ich den Text? Bruno P. Kremer beantwortet auf nur 200 Seiten alle wichtigen Fragen zur wissenschaftlichen Arbeit in den naturwissenschaftlichen Fächern. Dabei beschränkt er sich auf das für Studenten und Schüler wirklich notwendige Wissen und lässt jeglichen unnützen Ballast beiseite. Dieser praktische Ratgeber verhilft Ihnen zur erfolgreichen wissenschaftlichen Arbeit - vom Referat bis zur Examensarbeit.

  15. Wer entdeckte die Allgemeine Relativitätstheorie? Prioritätsstreit zwischen Hilbert und Einstein

    NASA Astrophysics Data System (ADS)

    Sommer, Klaus P.

    2005-09-01

    Im November 1915 arbeiteten Albert Einstein und David Hilbert an den Feldgleichungen der Gravitationstheorie. Im Jahre 1997 behaupteten die Wissenschaftshistoriker Corry, Renn und Stachel in einer viel beachteten Arbeit, Hilbert habe die entscheidenden Formeln von Einstein gestohlen. Grundlage ihrer Argumentation war eine wieder gefundene Korrekturfahne von Hilberts entscheidender Arbeit. Die Physikhistorikerin Daniela Wuensch bringt jedoch detaillierte Argumente dafür vor, dass die entscheidende Quelle, nämlich die Korrekturfahne, in neuerer Zeit manipuliert worden ist, um Einsteins Priorität unangetastet zu lassen. Einstein bleibt aber der Entdecker der Allgemeinen Relativitätstheorie.

  16. Physik gestern und heute Suprafluidität - Von den Schwierigkeiten einer Messung

    NASA Astrophysics Data System (ADS)

    Sichau, Christian

    2003-03-01

    Der Vater der Tieftemperaturphysik, Heike Kammerlingh Onnes, benötigte zu Beginn des 20. Jahrhunderts für die Verflüssigung von wenigen Litern Heliums noch mehrere Jahre, eine riesige Apparatur und viel Geld. Heute gelingt dies routinemäßig. Die Untersuchung der Materie bei tiefen Temperaturen, insbesondere zur Suprafluidität, bietet viele Überraschungen.

  17. 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.

  18. Matthias Falter und die frühe Halbleitertechnik in der DDR

    NASA Astrophysics Data System (ADS)

    Dittmann, Frank

    Nach einer ganzen Reihe von Vorarbeiten weltweit1 konnten im Dezember 1947 die amerikanischen Physiker Walter H. Brattain, John Bardeen und William Shockley in den Bell Laboratories den Transistoreffekt demonstrieren. Damit legten sie den Grundstein für die Mikroelektronik als Basistechnologie des Informationszeitalters.

  19. [Naturheilkunde und Komplementärmedizin in medizinischen Leitlinien - können europäische Normen Leitlinien für Naturheilkunde und Komplementärmedizin verdrängen?].

    PubMed

    Jütte, Robert

    2016-01-01

    Leitlinien machen in der Komplementärmedizin, wie das Beispiel der Naturheilkunde zeigt, durchaus Sinn. Sie ergänzen zum Wohle des Patienten und zur besseren Orientierung des Therapeuten die bislang, auch auf europäischer Ebene, bereits bestehenden Leitlinien, die ständig weiterentwickelt werden. Diese Ergänzung ist dringend notwendig, weil die meisten der vorliegenden Leitlinien einzelner Fachgesellschaften die Forschungsergebnisse der Komplementärmedizin, die zum Teil beachtlich und auch evidenzbasiert sind, zum Nachteil des Patienten ignorieren. Es ist bedauerlich, dass einige Richtungen der Komplementärmedizin jedoch meinen, dass eine europäische Norm, wie sie beispielsweise Osteopathen und Homöopathen mithilfe des europäischen Normungsinstituts (CEN) durchzusetzen hoffen, sie in ihrem Kampf um Anerkennung weiterbringen wird. Der Patient, der auf eine individuelle und bestmögliche Behandlung wert legt, wird jedenfalls davon nicht profitieren.

  20. „Überholen ohne einzuholen“ Die Entwicklung von Technologien für übermorgen in Kernenergie und Mikroelektronik der DDR

    NASA Astrophysics Data System (ADS)

    Barkleit, Gerhard

    Dem nuklearen Patt zwischen Ostblock und westlichem Staatenbündnis ist es nach weitgehend übereinstimmender Auffassung von Politik und Wissenschaft zu danken, dass der "Kalte Krieg" in der zweiten Hälfte des 20. Jahrhunderts nicht zum weltumfassenden Flächenbrand eskalierte. An der raschen Herstellung dieses Patts waren zwei Dresdner Physiker maßgeblich beteiligt, deren einer im Manhattan-Projekt in den USA gearbeitet hatte und später in England der Spionage für die Sowjetunion und des Verrats des Know-how der Atombombe überführt wurde.

  1. Werk und Leben Walter Christallers . Auszüge aus der Festrede anläßlich der Verleihung des Walter-Christaller-Preises 1996

    NASA Astrophysics Data System (ADS)

    Hottes, Ruth

    1997-03-01

    Unter der Betreuung und Federführung von Robert Gradmann promovierte am Erlanger Geographischen Institut 1932 Walter Christaller mit seiner Dissertation `Die Zentralen Orte in Süddeutschland'. Diese mit summa cum laude bewertete Monographie sollte die vielleicht berühmteste geographische Doktorarbeit unseres Jahrhunderts werden. Sie hat in den vergangenen Jahrzehnten einen beispiellosen Siegeszug angetreten. Heute gilt sie für Geographie, Raumwirtschaftslehre, Stadtforschung und Standorttheorie als eine bahnbrechende Grundkonzeption, und sie ist von größter Bedeutung für Raumordnungspolitik und Planungspraxis."

  2. Campus Single Sign-On und hochschulübergreifendes Identity Management

    NASA Astrophysics Data System (ADS)

    Hommel, Wolfgang

    Das im Rahmen von IntegraTUM für die TUM geschaffene Identity & Access Management System setzt das Paradigma unified login um, d. h. ein Benutzer kann alle für ihn relevanten Dienste innerhalb der Hochschule mit derselben Loginname-/Passwortkombination nutzen. Dieser Artikel zeigt, wie auf Basis der Software Shibboleth und der deutschlandweiten Hochschulföderation DFN-AAI als weitere Mehrwerte das campusweite web single sign-on und die nahtlose Nutzung zahlreicher externer Web-Anwendungen erreicht werden. Als Beispiel für die Abläufe bei der Erschließung neuer Dienste für die hochschulübergreifende Nutzung wird die Anbindung von Learning Management Systemen auf Basis des DFN-AAI E-Learning-Profils diskutiert. Den umfassenden Vorteilen werden schließlich die aktuellen technischen Grenzen bei der Umsetzung des hochschulübergreifenden Identity Management gegenübergestellt.

  3. Vorausschauend Planen, Gezielt Handeln — Über Die Regelung Und Steuerung Technischer Prozesse

    NASA Astrophysics Data System (ADS)

    Grüne, Lars; Sager, Sebastian; Allgöwer, Frank; Bock, Hans Georg; Diehl, Moritz

    Seit Beginn der industriellen Revolution nimmt die Steuerungs- und Regelungstechnik eine Schlüsselstellung in vielen technischen Bereichen ein. James Watts Fliehkraftregler für Dampfmaschinen ist eines der frühen Beispiele eines extrem erfolgreichen Reglerkonzepts, von dem Ende der 1860er Jahre geschätzte 75000 Exemplare allein in England im Einsatz waren [2, S. 24]. Etwa um diese Zeit begannen Ingenieure, motiviert durch die immer höhere Komplexität der zu regelnden Maschinen, sich systematisch mit theoretischen Grundlagen der Regelung zu beschäftigen. Dies führte unausweichlich zu der Einsicht, dass das dynamische Verhalten der geregelten Systeme nur mit Hilfe der Mathematikverstanden und weiterentwickelt werden konnte, oder wie Werner von Siemens, ein weiterer technischer Pionier in diesem Bereich es formulierte: "Ohne Mathematik tappt man doch immer im Dunkeln.“

  4. Die Quantenwelt - unbestimmt und nichtlokal?: Interpretation verschränkter Zustände

    NASA Astrophysics Data System (ADS)

    Fink, Helmut

    2004-07-01

    Das aufblühende Gebiet der Quanteninformationsverarbeitung belebt die alte Frage, wie das Phänomen der quantenphysikalischen Verschränktheit zu interpretieren sei. Besonders das berühmte Gedankenexperiment von Einstein, Podolsky und Rosen rückt wieder in das Zentrum der Aufmerksamkeit, seit Laborexperimente an verschränkten Quantensystemen durchgeführt werden, deren Teile räumlich weit von einander entfernt sind. Kann ein Teil eines solchen verschränkten Systems mit Überlichtgeschwindigkeit spüren, dass an einem weit entfernten anderen Teil gemessen wird? Hinter dieser Frage steckt die Vorstellung, es gebe einen nichtlokalen Mechanismus in der Natur. Diese Vorstellung erweist sich jedoch als keineswegs zwingend und sogar als irreführend, wenn man akzeptiert, dass die Werte von Beobachtungsgrößen in Quantenzuständen objektiv unbestimmt sind. Sie entstehen erst dort, wo wirklich gemessen wird.

  5. Die Struktur von schlankem Materialfluss mit Lean Production Kanban und Innovationen

    NASA Astrophysics Data System (ADS)

    Scheid, Wolf-Michael

    In der Literatur wird Materialfluss überwiegend in Spezialdisziplinen betrachtet, etwa der Steuerungslogik, der Logistiktechnik oder dem Supply Chain Management. Ein charakterisierendes Merkmal des Materialflusses ist jedoch, dass er sich aus vielfältigen Einzelbausteinen zusammensetzt, die alle harmonisch abgestimmt sein müssen. Die maximal erreichbare Effizienz wird nicht durch Höchstleistungen in dem einen oder anderen Spezialthema bestimmt, sondern durch das schwächste Glied im gesamten komplexen Netzwerk. Den Schnittstellen zwischen den betroffenen Fachbereichen in einem Unternehmen kommt hier eine ganz besondere Bedeutung zu: Erst ein harmonischer Einklang ermöglicht hohe Effektivität. Dies setzt umfassendes Verständnis für interdisziplinäre Notwendigkeiten, ein hohes Maß an Abstimmung mit den operativen Prozessen und letztlich einen einvernehmlichen Umgang und den Respekt vor den Problemstellungen des Anderen voraus.

  6. Physik gestern und heute Die Messung elektrostatischer Kräfte

    NASA Astrophysics Data System (ADS)

    Heering, Peter

    2002-11-01

    Im Jahre 1785 veröffentlichte der französische Militäringenieur Charles Augustin Coulomb das Kraft-Abstand-Gesetz für elektrische Ladungen. Bereits zuvor hatte Henry Cavendish auf andere Art und Weise diese Beziehung nachgewiesen, aber nicht publiziert. Entsprechende Experimente wurden auch noch in jüngerer Zeit ausgeführt, da sie eine obere Abschätzung für die Ruhemasse des Photons erlauben.

  7. [Promoting Children from Socially Disadvantaged Backgrounds: The Mentoring Programme "Balu und Du"].

    PubMed

    Borrmann, B; Drexler, S; Müller-Kohlenberg, H

    2015-09-01

    We aimed to determine whether socially disadvantaged elementary school children profit health-wise from their participation in the mentoring programme "Balu und Du". For the evaluation study we compared an intervention group of 141 children with a stratified control group of 158 children. The project was able to reach elementary school children from socially disadvantaged families. The treatment group showed distinct advancements in the areas of self-organisation, the ability to concentrate, as well as achievement and learning motivation.

  8. Charakterisierung von Sulfotransferasen im Gastrointestinaltrakt von Mensch und Ratte und Aktivierung von Promutagenen in V79-Zellen, die eine intestinale Form (1B1) des Menschen und der Ratte exprimieren

    NASA Astrophysics Data System (ADS)

    Teubner, Wera

    2001-05-01

    Die Ausstattung der gastrointestinalen Mukosa des Menschen und der Ratte mit Sulfotransferasen wurde mit Hilfe von Immunodetektion und Enzymaktivitätsmessungen untersucht. In Proben aus Colon und Rektum von 39 Personen wurden die Formen h1A1, h1A3 und h1B1 identifiziert, wobei in einer weiteren Probe, die als einzige von einem an Colitis Ulcerosa erkrankten Patienten stammte, keine Sulfotransferasen nachgewiesen werden konnten. Bei der Immunblot-Analyse war das Expressionsmuster der einzelnen Formen in allen Proben ähnlich. In wenigen Proben waren die relativen Signalintensitäten der h1A1 und der h1B1 um die Hälfte erniedrigt. Der Gehalt von SULT an zytosolischem Protein zeigte einen bis zu 8 - 10fachen Unterschied, er betrug jedoch bei zwei Dritteln der Proben zwischen 0,15 und 0,3 (h1A1 und h1A3) bzw. 0,6 und 0,8 Promille (h1B1). Die Variation konnte nicht auf Alter, Geschlecht oder Krankheitsbild der Patienten zurückgeführt werden. Auch der für die allelischen Varianten der h1A1 beschriebene Effekt auf die Enzymaktiviät bzw. Stabilität konnte in der Menge an immunreaktivem Protein nicht in diesem Ausma detektiert werden. Die Allelhäufigkeit von h1A1*R und h1A1*H war gegenüber der gesunden Bevölkerung nicht verändert. In den sieben Proben aus dem Dünndarm (Coecum, viermal Ileum, Jejunum) konnten zusätzlich die Formen h1E1 und h2A1 identifiziert werden. Ein möglicherweise der Form h1C1 entsprechendes Protein wurde im Magen detektiert. Im Vergleich zum Menschen war die Expression in der Ratte stärker auf die Leber konzentriert. Während beim Menschen in allen untersuchten Abschnitten Sulfotransferasen in Mengen detektiert wurden, die in zwei Fällen (h1B1 und h1A3) sogar den Gehalt in der Leber überstiegen, beschränkte sich die Expression in der Ratte auf im Vergleich zur Leber geringe Mengen im Magen und Dickdarm. Nachgewiesen wurden die r1B1, r1A1 sowie eine nicht identifizierte Form von 35kD, bei der es sich vermutlich um die r1C2 handelt. Im

  9. Tanzendes Tier oder exzentrische Positionalität - Philosophische Anthropologie zwischen Darwinismus und Kulturalismus

    NASA Astrophysics Data System (ADS)

    Fischer, Joachim

    Zunächst kurz vorweg zu den Formeln im Titel: "exzentrische Positionalität“ ist der Kategorienvorschlag der Philosophischen Anthropologie (genauer: von Helmuth Plessner) für den Menschen, für seine "Sonderstellung“ unter den Lebewesen - ich werde diesen Begriff erläutern. So viel kann man sagen: Der Terminus ist nicht schwieriger als "Transzendentalität“ oder das "Apriori“ oder "Autopoiesis“, also Begriffe, mit deren Orientierungswert in der intellektuellen Öffentlichkeit bereits gespielt wird, bietet aber möglicherweise mehr Erschließungskraft als die Kunstbegriffe z. B. von Kant, Maturana oder Luhmann. Und "tanzendes Tier“ ist ein glücklicher Anschauungsbegriff, eine Art Übersetzung für "exzentrische Positionalität“ - also ein "verrücktes“ Lebewesen, eine Verrückung im evolutionären Leben, die dieses Lebewesen von Natur aus zu einer bestimmten Art von Lebensführung, nämlich Kultur nötigt. Die Absicht des Beitrages ist es, die Philosophische Anthropologie als eine spezifische Theorietechnik zu präsentieren, um einen adäquaten Begriff des Menschen zu erreichen, und zwar eine Theoriestrategie angesichts des cartesianischen Dualismus - also des Dualismus zwischen Naturalismus und Kulturalismus.

  10. Vergleich von rekombinanten Vaccinia- und DNA-Vektoren zur Tumorimmuntherapie im C57BL/6-Mausmodell

    NASA Astrophysics Data System (ADS)

    Johnen, Heiko

    2002-10-01

    In der vorliegenden Arbeit wurden Tumorimpfstoffe auf der Basis des Plasmid-Vektors pCI, modified vaccinia virus Ankara (MVA) und MVA-infizierten dendritischen Zellen entwickelt und durch Sequenzierung, Western blotting und durchflußzytometrische Analyse überprüft. Die in vivo Wirksamkeit der Vakzinen wurde in verschiedenen Tumormodellen in C57BL/6 Mäusen verglichen. Die auf dem eukaryotischen Expressionsvektor pCI basierende DNA-Vakzinierung induzierte einen sehr wirksamen, antigenspezifischen und langfristigen Schutz vor Muzin, CEA oder beta-Galactosidase exprimierenden Tumoren. Eine MVA-Vakzinierung bietet in den in dieser Arbeit durchgeführten Tumormodellen keinen signifikanten Schutz vor Muzin oder beta-Galactosidase exprimierenden Tumoren. Sowohl humane, als auch murine in vitro generierte dendritische Zellen lassen sich mit MVA – im Vergleich zu anderen viralen Vektoren – sehr gut infizieren. Die Expressionsrate der eingefügten Gene ist aber gering im Vergleich zur Expression in permissiven Wirtszellen des Virus (embryonale Hühnerfibroblasten). Es konnte gezeigt werden, daß eine MVA-Infektion dendritischer Zellen ähnliche Auswirkungen auf den Reifezustand humaner und muriner dendritischer Zellen hat, wie eine Infektion mit replikationskompetenten Vakzinia-Stämmen, und außerdem die Hochregulation von CD40 während der terminalen Reifung von murinen dendritischen Zellen inhibiert wird. Die während der langfristigen in vitro Kultur auf CEF-Zellen entstandenen Deletionen im MVA Genom führten zu einer starken Attenuierung und dem Verlust einiger Gene, die immunmodulatorische Proteine kodieren, jedoch nicht zu einer Verminderung des zytopathischen Effekts in dendritischen Zellen. Die geringe Expressionsrate und die beobachtete Inhibition der Expression kostimulatorischer Moleküle auf dendritischen Zellen kann für eine wenig effektive Induktion einer Immunantwort in MVA vakzinierten Tieren durch cross priming oder die direkte Infektion

  11. IntegraTUM Teilprojekt E-Mail: Aufbau eines mandantenfähigen Groupware-Services und seine Integration in Identity Management und E-Mail Infrastruktur der Technischen Universität München

    NASA Astrophysics Data System (ADS)

    Diehn, Max

    Die E-Mail-Infrastruktur an der Technischen Universität München (TUM) ist historisch bedingt sehr heterogen und komplex. Viele Einrichtungen müssen wertvolle Arbeitskraft auf die Administration eigener Mailserver verwenden. Auf der anderen Seite wird bei einigen Einrichtungen der Ruf nach Groupware-Funktionalitäten wie z.B. gemeinsame Kalender immer lauter. Das Teilprojekt E-Mail stellt einen zentralen Mail- und Groupware-Service bereit, der den Einrichtungen ermöglichen soll, den Betrieb eigener Server und zugehöriger Systeme (etwa lokaler Benutzerverwaltungen) für diesen Zweck aufzugeben und diese Dienste an das Teilprojekt E-Mail zu migrieren, ohne ihre Verwaltungshoheit oder ihre Maildomains aufgeben zu müssen. Dieser Service versteht sich als eine Ergänzung zur bestehenden Grundversorgung der TUM mit den Maildiensten des myTUM-Mailers, ist mandantenfähig aufgebaut und kann daher künftig neben der TUM auch weiteren Organisationen im Münchner Wissenschaftsnetz zur Verfügung gestellt werden.

  12. Periodisches Hitzdrahtverfahren zur Messung von Wärme- und Temperaturleitfähigkeit von geringen Stoffmengen

    NASA Astrophysics Data System (ADS)

    Griesinger, A.; Spindler, K.; Hahne, E.

    Zusammenfassung Es wird ein Meßverfahren zur gleichzeitigen Bestimmung der Wärme- und der Temperaturleitfähigkeit von geringen Stoffmengen beschrieben. Neben Messungen an hochviskosen Flüssigkeiten eignet sich das Verfahren besonders für Messungen an Pulver-Schüttungen. Das Meßverfahren basiert auf dem transienten Hitzdraht-Verfahren. In einem dünnen Platindraht fließt ein sinusförmiger Wechselstrom, der den Draht periodisch erwärmt. Es entstehen thermische Wellen, die in die umgebende Probe eindringen. Die Amplitude und die Phasenlage der thermischen Wellen in der Probe hängen von der Temperaturleitfähigkeit a und der Wärmeleitfähigkeit λ der Probe ab. Die Temperaturschwingung in der Probe wird mit Hilfe des Platindrahtes gemessen, der gleichzeitig als Widerstandsthermometer eingesetzt wird. Meßwerte von Wasser und Glycerin zeigen eine gute Übereinstimmung mit Literaturwerten. Das Meßverfahren zeichnet sich dadurch aus, daß zur Bestimmung der Wärme- und Temperaturleitfähigkeit nur 13 ml einer Probe benötigt werden. Es werden Meßwerte einer Zeolith-Schüttung unter Wasserstoffbeladung dargestellt. A measuring procedure for the simultaneous determination of the thermal conductivity and thermal diffusivity of small quantities is described. The procedure is suited for high-viscous fluids and for powdery material. The measuring principle is based on the transient hot-wire method. A sinusoidal alternating current flows through a thin platinum wire and heats up the wire periodically. This results in thermal waves, which penetrate into the surrounding sample. The amplitude and the phase shift of the thermal waves depend on the thermal diffusivity ``a'' and the thermal conductivity ``λ'' of the sample. The temperature oscillation in the sample is measured by means of the platinum wire, which is simultaneously applied as a resistance thermometer. The values measured for water and glycerine correspond well to those given in literature. Results of the

  13. Netzgenerierung und Finite-Elemente-Simulation muskulärer Strukturen unter Beachtung korrespondierender histologischer Schnittpräparate

    NASA Astrophysics Data System (ADS)

    Weichert, Frank; Schröder, Andreas; Landes, Constantin; Walczak, Lars; Müller, Heinrich; Wagner, Mathias

    In dieser Arbeit wird ein Verfahren zur Netzgenerierung und Finite-Elemente-Simulation muskulärer Strukturen vorgestellt. Eine Herausforderung liegt dabei in der Fusion der Simulationsergebnisse mit den Daten histologischer Schnittpräparate. Basierend auf segmentierten histologischen Daten wird eine Rekonstruktion der relevanten muskulären Strukturen mittels eines BCC-Tetraedernetzes initiiert. Dieses wird getriggert über einen Level-Set-Ansatz. Die Deformation des Muskels wird dann mittels eines hyperelastischen Materialgesetzes modelliert und mithilfe der Finite-Elemente-Methode simuliert. Anschließend erfolgt eine Projektion der Ergebnisse der Simulation auf die histologischen Schnittpräparate. Als Anwendungsfall wurden Daten abortiver Feten mit einer Spaltbildung im Bereich der Lippen-, Kiefer- und Gaumenregion herangezogen.

  14. Gesellschaft, Lebensgemeinschaft, Ökosystem - Über die Kongruenz von politischen und ökologischen Theorien der Entwicklung

    NASA Astrophysics Data System (ADS)

    Voigt, Annette

    Im Jahr 1859 veröffentlichte Charles Darwin "On the Origin of Species“. Seine Evolutionstheorie ist das wohl spektakulärste Beispiel einer naturwissenschaftlichen Theorie großer gesellschaftlicher Relevanz. Ihre verschiedenen Facetten wurden in der Öffentlichkeit kontrovers diskutiert, unter anderem auch ihre Anwendung zur Erklärung von Zuständen und Prozessen menschlicher Gesellschaften. Zum Teil wurde die Seiensweise der Natur - scheinbar unabhängig von gesellschaftlichen Interessen - für die Erklärung und Legitimation gesellschaftlicher Zustände oder die Legitimation von politischen Ideologien herangezogen (Sozialdarwinismus). Denn Gesellschaft funktioniere ja so, wie Darwin die Natur erklärt habe: es herrsche z. B. Konkurrenzkampf, Auslese und Arbeitsteilung, Erfolg hätten diejenigen, die sich an die Bedingungen am Besten anpassten.

  15. Mercaptursäure und Nukleosidaddukt im Harn als Biomarker in 1-Hydroxymethylpyren-exponierten Ratten

    NASA Astrophysics Data System (ADS)

    Ma, Lan

    2002-01-01

    1-Methylpyren (MP) ist hepatokanzerogen in neugeborenen männlichen Mäusen. Durch Hydroxylierung an der benzylischen Stelle und anschließende Sulfonierung wird MP zu DNA-reaktivem 1-Sulfooxymethylpyren (SMP) aktiviert. In der Ratte führt die Exposition des benzylischen Alkohols, 1-Hydroxymethylpyren (HMP), zur DNA-Adduktbildung in verschiedenen Geweben. Eventuelle Konsequenz der Toxifizierung ist die Ausscheidung entsprechender Mercaptursäure und Nukleosidaddukt im Harn, welche aufgrund ihrer Herkunft als Biomarker eignen könnten. In dieser Arbeit wird die Ausscheidung der Mercaptursäure und des N2-Desoxyguanosinadduktes in HMP-exponierten Ratten untersucht. Nach der Applikation von HMP bzw. MP wurden weniger als 1 % der Dosis als MPMA über Urin und Faeces ausgeschieden (0 - 48 h). Die Ausscheidung erfolgt hauptsächlich in den ersten 24 h nach der Applikation. MPdG konnte weder in Urin noch in Faeces der HMP-behandelten Tieren identifiziert werden. Nach direkter SMP-Applikation wurde MPdG nur in sehr geringe Menge (weniger als 0,9 ppm in 12 h) im Urin gefunden. Aufgrund der geringen Menge eignet sich MPdG nicht als Biomarker. MPMA dagegen, lässt sich analytisch gut erfassen. Es sollte daher untersucht werden, ob MPMA die Toxifizierung des HMP wiederspiegelt. Die Voraussetzung dafür ist die Kenntnisse über das Metabolismusmuster von HMP. Es wurde daher umfassende Untersuchungen zum Metabolismus des HMP durchgeführt. Die Ergebnisse zeigten, dass mehr als 80 % der Metaboiten in ihrer oxidierten Form (PCS, deren Glucuronsäure-Konjugate sowie phenolische Sulfatester der PCS) ausgeschieden wurden. Demnach spielt die Oxidation des HMP zu PCS eine sehr wichtige Rolle bei der Detoxifizierung und Ausscheidung von HMP. Ferne konnte nachgewiesen werden, dass die Enzyme Alkohol- und Aldehyd-Dehydrogenase an der Oxidation von HMP beteiligt waren. Die Inhibitoren Disulfiram und Ethanol der o. g. Enzyme wurde daher zur Modulation der Detoxifizierung in vivo eingesetzt

  16. The Crystal Structure of the Extracellular 11-heme Cytochrome UndA Reveals a Conserved 10-heme Motif and Defined Binding Site for Soluble Iron Chelates.

    SciTech Connect

    Edwards, Marcus; Hall, Andrea; Shi, Liang; Fredrickson, Jim K.; Zachara, John M.; Butt, Julea N.; Richardson, David; Clarke, Thomas A.

    2012-07-03

    Members of the genus Shewanella translocate deca- or undeca-heme cytochromes to the external cell surface thus enabling respiration using extracellular minerals and polynuclear Fe(III) chelates. The high resolution structure of the first undeca-heme outer membrane cytochrome, UndA, reveals a crossed heme chain with four potential electron ingress/egress sites arranged within four domains. Sequence and structural alignment of UndA and the deca-heme MtrF reveals the extra heme of UndA is inserted between MtrF hemes 6 and 7. The remaining UndA hemes can be superposed over the heme chain of the decaheme MtrF, suggesting that a ten heme core is conserved between outer membrane cytochromes. The UndA structure is the first outer membrane cytochrome to be crystallographically resolved in complex with substrates, an Fe(III)-nitrilotriacetate dimer or an Fe(III)-citrate trimer. The structural resolution of these UndA-Fe(III)-chelate complexes provides a rationale for previous kinetic measurements on UndA and other outer membrane cytochromes.

  17. Strömungs- und Tracer-Transportmodellierung am Natural Attenuation-Standort Zeitz

    NASA Astrophysics Data System (ADS)

    Gödeke, Stefan; Weiß, Holger; Geistlinger, Helmut; Fischer, Anko; Richnow, Hans Herrmann; Schirmer, Mario

    Kurzfassung Numerische Modelle spielen bei der Bewertung von Natural-Attenuation-Prozessen an Feldstandorten eine bedeutende Rolle. Daher ist es wichtig diese mit Felddaten zu überprüfen und gegebenenfalls erneut zu kalibrieren. Die Modellierung des Transports eines konservativen Tracers auf der Grundlage von Felddaten ergab eine zuverlässigere Abschätzung der Kf-Werte des numerischen Strömungsmodells für den Standort, als es mit anderen Methoden (z. B. Analyse der Siebwerte) möglich war. Die Kf-Werte berechnet aus Siebanalysen führten zu einer deutlichen Unterschätzung der Tracerausbreitungsgeschwindigkeit. Zwischen beobachteten und berechneten Durchbruchskurven wurde eine gute Übereinstimmung erzielt, sodass das Modell für die Planung weiterer Feldexperimente und als Grundlage für eine reaktive Transportmodellierung genutzt werden kann. Die hydraulischen Leitfähigkeiten im Untersuchungsgebiet ändern sich in vertikaler und horizontaler Richtung im Bereich weniger Dezimeter z. T. stark, was von dem numerischen Modell nur begrenzt wiedergegeben werden kann. Für die Modellierung der Tracerausbreitung ist die Kenntnis der Kf-Wert-Verteilung im Bereich des Infiltrationsbrunnens besonders wichtig, weil sie die Struktur der Tracerfahne im Abstrom wesentlich beeinflusst. Die Wahl des numerischen Verfahrens für die Lösung der Transportgleichung hatte bei der Kalibrierung des Strömungsmodells einen großen Einfluss. Während mit dem in MT3DMS vorhandenen TVD (〝Total Variation Diminishing``)-Algorithmus eine akzeptable Lösung gefunden wurde, zeigten sich bei der Verwendung des MOC (〝Method of Characteristics``)-Verfahrens signifikante Fehler in der Massenbilanz. Reliable numerical models are of primary importance for the evaluation of Natural-Attenuation processes at field sites. Modelling the flow and transport of a conservative tracer, a more realistic distribution of the hydraulic conductivity values for the numerical model was achieved and a good

  18. Peter Andreas Hansen und die astronomische Gemeinschaft - eine erste Auswertung des Hansen-Nachlasses.

    NASA Astrophysics Data System (ADS)

    Schwarz, O.; Strumpf, M.

    The literary assets of Peter Andreas Hansen are deposited in the Staatsarchiv Hamburg, the Forschungs- und Landesbibliothek Gotha and the Thüringer Staatsarchiv Gotha. They were never systematically investigated. The authors present here some results of a first evaluation. It was possible to reconstruct the historical events with regard to the maintenance of the Astronomische Nachrichten and the Altona observatory in 1854. Hansen was a successful teacher for many young astronomers. His way of stimulating the evolution of astronomy followed Zach's tradition.

  19. Identification and Characterization of UndA-HRCR-6, an Outer Membrane Endecaheme c-Type Cytochrome of Shewanella sp. Strain HRCR-6

    SciTech Connect

    Shi, Liang; Belchik, Sara M.; Wang, Zheming; Kennedy, David W.; Dohnalkova, Alice; Marshall, Matthew J.; Zachara, John M.; Fredrickson, Jim K.

    2011-08-01

    The outer membrane decaheme c-type cytochromes (c-Cyt) MtrC and OmcA of Shewanella oneidensis MR-1(MR-1) play critical roles in extracellular reduction of iron [Fe(III)] oxides and uranium [ U(VI)]. To identify and characterize the outer membrane c-Cyts found in the metal-reducing Shewanella strains isolated from the Hanford Reach of the Columbia River (HRCR), 7 HRCR isolates were tested for the presence of mtrC, omcA and undA1 (a gene encoding a putative 11-heme c-Cyt) homologues in their genomes. All 7 tested strains possessed an mtrC homologue, while 3 strains had an omcA homologue and the remaining 4 strains contained an undA1 homologue. The coding region of an undA1 homologue from HRCR isolate 6 was cloned and sequenced. Because it was 93% identical to the UndA of S. baltica OS223, the protein product encoded by this sequenced gene was named as UndA-HRCR6. In MR-1, UndA-HRCR6 (i) restored an MR-1 mutant’s ability to reduce solid phase ferrihydrite at 40% of that for MR-1 wild type, (ii) increased extracellular formation of UO2 associated with the outer membrane and extracellular polymeric substances in a U(VI) reduction assay and (iii) was secreted to the extracellular environment by bacterial type II secretion system. UndA-HRCR6 was purified from the membrane fraction following its overexpression in MR-1 cells. Purified UndA-HRCR6 possessed 11 heme-Fe and reduced ferric complexes. Collectively, these results show that UndA-HRCR6 is an outer membrane endecaheme c-Cyt and can serve an extracellular metal reductase with functions similar to that of MR-1 MtrC and OmcA.

  20. Reply to ``Comment on `Effect of α-nucleus potential on the 27Al(α,t)28Si reaction' ''

    NASA Astrophysics Data System (ADS)

    Das, S. K.; Tariq, A. S. B.; Rahman, A. F. M. M.; Roy, P. K.; Huda, M. N.; Mondal, A. S.; Basak, A. K.; Gupta, H. M. Sen; Malik, F. B.

    2000-10-01

    The point stressed by Michel and Reidemeister is that the Michel potential in our work is not final and an adjustment of the parameter α gives an elastic distribution and a potential similar to that obtained for the molecular one. This is usual in the absence of the elastic data at large angles as commented on by Tariq et al. [Phys. Rev. C 59, 2558 (1999)]. However, the inadequacy of the Michel potential with the parameter α=7.4 in the description of the (α,t) reaction data leads to a finding of a better value for the parameter by Michel and Reidemeister. This justifies the use of the molecular and Michel potentials in the analysis of the reaction and conforms to the suggestion by Satchler (Ref. [40] in Tariq et al.) that the performance of a potential in nonelastic processes is a stronger criterion in its selection.

  1. 76 FR 9513 - Airworthiness Directives; BURKHART GROB LUFT-UND Model G 103 C Twin III SL Gliders

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-18

    ... Directives; BURKHART GROB LUFT-UND Model G 103 C Twin III SL Gliders AGENCY: Federal Aviation Administration... Twin III SL powered sailplane has been reported. Grob Aircraft AG suspects that the possible reasons... states: The in-flight loss of a propeller and pulley wheel from the engine of a Grob G 103 C Twin III...

  2. 76 FR 27240 - Airworthiness Directives; BURKHART GROB LUFT-UND Model G 103 C Twin III SL Gliders

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-11

    ... GROB LUFT-UND Model G 103 C Twin III SL Gliders AGENCY: Federal Aviation Administration (FAA... propeller and pulley wheel from the engine of a Grob G 103 C Twin III SL powered sailplane has been reported... and pulley wheel from the engine of a Grob G 103 C Twin III SL powered sailplane has been...

  3. Interaktive Visualisierung von Abständen und Ausdehnungen anatomischer Strukturen für die Interventionsplanung

    NASA Astrophysics Data System (ADS)

    Rössling, Ivo; Cyrus, Christian; Dornheim, Lars; Hahn, Peter; Preim, Bernhard; Boehm, Andreas

    Im Rahmen der Interventionsplanung muss der Chirurg therapierelevante Entscheidungen auf Basis räumlicher Relationen anatomischer Strukturen treffen. Interaktive 3D-Visualisierungen unterstützen diesen Prozess qualitativ. Quantitative Fragestellungen (Tumorausdehnung, Infiltrationstiefe, etc.) erfordern die Integration einer Bemaßung, deren Nutzen wesentlich von einer geeigneten Darstellung abhängt. In dieser Arbeit haben wir allgemeine Kriterien für die Eignung von Visualisierungen von Bemaßungen in interaktiven 3D-Szenen erarbeitet. Daran orientierend haben wir verschiedene Varianten der Darstellung von Abständen und Ausdehnungen anatomischer Strukturen betrachtet und ihr Erscheinungsbild hierzu zweckmäßig parametrisiert. Die Ausprägungen dieser Darstellungsparameter wurden in einer Studie auf ihre visuellen Wirkung hin an Chirurgen evaluiert. Es zeigte sich, dass die befragten Mediziner höchsten Wert auf Kohärenz und klare Zuordnung der Bemaßung setzten und überraschenderweise dafür sogar Abstriche in der direkten Lesbarkeit in Kauf nahmen.

  4. Zeitschrift fur erziehungs--und sozialwissenschaftliche Forschung (Journal for Education and Social Sciences Research), 1984-1988 (11 issues).

    ERIC Educational Resources Information Center

    Zeitschrift fur erziehungs--und socialwissenschaftliche Forschung (Journal for Education and Social Sciences Research), 1984

    1984-01-01

    Recognizing a growing globalization of nations and cultures, "Zeitschrift fur erziehungs--und sozialwissenchaftliche Forschung" brings together educational and social science research topics that address the interactions between education and society in their pedagogical, social, physical, economic, legal, and administrative dimensions.…

  5. Schlüsselkomponenten für Roboter in der Produktion Roboterhaut und Sicherheitskonzept für die Mensch-Roboter Kooperation

    NASA Astrophysics Data System (ADS)

    Denkena, B.; Hesse, P.; Friederichs, J.; Wedler, A.

    Vorgestellt wird der Aufbau einer aktiven Sensor-Matrix zur Abstands- und Kontaktdetektion in der Robotik. Diese besteht aus einem Sensornetzwerk zur Fusion und Überlagerung differenter physikalischer Wirkprinzipien. Die Sicherheit der I2C-Bus Kommunikation, der Aufbau der Roboterhaut, Ergebnisse der Abstandsdetektion mit Infrarot-, und Ultraschallsensorik werden dargestellt. Ferner wurden Temperatur-, und Beschleunigungssensoren auf die Oberfläche der Roboterhaut aufgebracht um Informationen über die Umgebung sicher an ein übergeordnetes Leitsystem zu übertragen. Eine unterlagerte sichere Roboterhaut mit Kontaktdetektion zeigt als einfache Schlüsselkomponente ein analoges Ausschaltverhalten für geringe Latenzzeiten. Als Schluss wird auf den Einsatz an einem Industrieroboter in der Produktion ohne trennende Schutzeinrichtungen (OTS) eingegangen.

  6. Rekonfigurationstechniken und Anwendungsgebiete für ein programmierbares Gm-C Analog-Filter

    NASA Astrophysics Data System (ADS)

    Becker, J.; Henrici, F.; Manoli, Y.

    2006-09-01

    FPAAs (Field Programmable Analog Arrays) erlauben es, analoge Signalübertragungsfunktionen auf Hardware abzubilden, die von veränderbaren digitalen Konfigurationsdaten abhängen. Sowohl für das Design von Filterstrukturen auf Systemebene als auch für die genaue Simulation ihrer analogen Übertragungsfunktion auf Transistorebene ist es dabei notwendig, die entsprechenden Konfigurationsdaten einzugeben bevor die Phasen/Betragsanalyse durchgeführt werden kann. Die vorliegende Arbeit stellt ein graphisches Entwurfsprogramm zur Instantiierung von analogen Filtern für ein FPAA mit 17 gm-C Blöcken vor. Es wird über erste Simulationsergebnisse berichtet, die die Machbarkeit mit Eckfrequenzen bis zu hundert Mhz bestätigen. Simulierte Übertragungsfunktionen von grundlegenden Bausteinen werden mit der Theorie verglichen und zu einer exemplarischen Instantiierung eines Butterworth-Filters der vierten Ordnung weitergeführt.

  7. Die Anfaenge der Melker Bibliothek - Neue Erkenntnisse zu Handschriften und Fragmenten aus der Zeit vor 1200

    NASA Astrophysics Data System (ADS)

    Glaßner, Christine; Haidinger, Alois

    1996-04-01

    Shortly after Benedictine monks started monastic life in Melk in 1089 the scriptorium was flourishing under abbot Erchenfried (1121-1164). Noteworthy is Cod. 391, a manuscript written in its main part in 1123, but used by the monks as a yearbook with handwritten entries up to the 16th century. This manuscript was also an important source for the publication which dealt with the history of the scriptorium in 12th century. By examining the entries in this book the period of the activity of at least three unknwon writers in this era could be identified. It was the first time that not only the intact volumes but also the manuscripts preserved as fragments in the binding were examined. At the beginning of th 13th century the number of books held in the collection according to the result of this examination was 68. Another remarkable point of the exhibition and of the publication refering to the exhibition was Cod. 412, the oldest manuscript of the monastery, written in early 9th century and containing texts on natural sciences and astronomy by Venerable Bede. Three copies of this manuscript were done during 12th century, one of them probably in Melk, all of them with nearly identical consistency except the catalogue of signs of the zodiac which was ascribed erroneously to Venerable Bede in the Middle Ages: Vatican, Cod. Vat. lat. 643, Zwettl, Cod. 296 (copy of the Vatican manuscript), Klosterneuburg, Cod. 685 (copy of the Zwettl manuscript done in Klosterneuburg). Kurz nach Einführung der Benediktiner in Melk im Jahr 1089 erlebte das Melker Skriptorium unter Abt Erchenfried (1121-1163) seine erste Blüte. Hervorzuheben ist eine im Jahr 1123 angelegte Chronik, die bis in das 16. Jahrhundert durch Annaleneintragungen und andere wichtige Texte zur Geschichte des Klosters ergänzt wurde (Cod. 391). Diese Handschrift ist zugleich eine der wichtigsten Quellen zur Geschichte des Melker Skriptoriums im 12. Jahrhundert, dem sich die Publikation widmet. Mit Hilfe einer genaueren

  8. Bruno Braunerde und die Bodentypen - Learning about soil diversity and soil functions with cartoon characters

    NASA Astrophysics Data System (ADS)

    Hofmann, Anett

    2015-04-01

    "Bruno Braunerde und die Bodentypen" is a German-language learning material that fosters discovery of soil diversity and soil functions in kids, teens and adults who enjoy interactive learning activities. The learning material consists of (i) a large poster (dimensions 200 x 120 cm) showing an imaginative illustrated landscape that could be situated in Austria, Switzerland or southern Germany and (ii) a set of 15 magnetic cards that show different soil cartoon characters, e.g. Bruno Braunerde (Cambisol), Stauni Pseudogley (Stagnic Luvisol) or Heidi Podsol (Podzol) on the front and a fun profession and address (linked to the respective soil functions) on the back side. The task is to place the soil cartoon characters to their 'home' in the landscape. This learning material was developed as a contribution to the International Year of Soils 2015 and is supported by the German, Austrian and Swiss Soil Sciences Societies and the Swiss Federal Office for the Environment. The soil cartoon characters are an adaptation of the original concept by the James Hutton Institute, Aberdeen, Scotland (www.hutton.ac.uk/learning/dirt-doctor).

  9. Analyse und Entwurf von hochbitratigen Clock-and-Data-Recovery Schaltungen in CMOS-Technologie

    NASA Astrophysics Data System (ADS)

    Bremer, J.-K.; Zemko, C.; Schmackers, J.; Mathis, W.

    2007-06-01

    In dieser Arbeit wird ein neuartiges Schaltungskonzept für die Realisierung eines Phasendetektors einer Clock-and-Data-Recovery Schaltung vorgestellt. Es handelt sich hierbei um eine nichtlineare Phasendetektorarchitektur, die nach dem Verfahren von Alexander arbeitet. Um die Funktionalität des Phasendetektors im Hochfrequenzbereich zu gewährleisten, wurden in dem Design sehr schnell schaltende HLO-Flip-Flops (high-speed latching operation flip-flop) verwendet. Ein wesentliches Entwurfsziel war die Begrenzung des selbstgenerierten Jitters des Phasendetektors. Der Schaltungsentwurf wurde mit der Simulationsumgebung Cadence Spectre durchgeführt und die Funktionalität der Schaltung im GHz-Bereich anhand von ausgewählten Simulationen verifiziert. This paper presents a novel realization concept for Clock-and-Data-Recovery circuits. Our Design uses a nonlinear phase detector architecture, which is based on the Alexander phase detection method. In order to ensure circuit functionality in the RF region, we use very fast switching HLO-Flip-Flops (high-speed latching operation flip-flop) in our design. The primal goal in our design was the minimization of self induced jitter of the phase detector. The accuracy of our circuit design and the functionality in the GHz regime is confirmed by various circuit simulations executed with the SPECTRE Simulator.

  10. Arzt und Hobby-Astronom in stürmischen Zeiten Der Büchernachlass des Doktor Johannes Häringshauser, Viertelsmedicus in Mistelbach (1630-1641) in der Melker Stiftsbibliothek.

    NASA Astrophysics Data System (ADS)

    Davison, Giles; Glaßner, Gottfried

    2009-06-01

    Auf der Suche nach astronomischer Literatur stieß Giles Davison in der Melker Stiftsbibliothek auf den Namen "Doctor Johannes Häringshauser“ als Besitzer seltener und interessanter astronomischer Werke u.a. von Johannes Regiomontan, Georg von Peuerbach, Michael Mästlin, Johannes Kepler und Daniel Sennert. Weitere in den Jahren 2007-2009 durchgeführte Nachforschungen ergaben, dass es sich um den von 1630-1641 in Mistelbach, Niederösterreich, als Landschaftsarzt tätigen Vater des Melker Konventualen und Bibliothekars Sigismund Häringshauser (1631-1698) handelt. Er wurde 1603 als Sohn des aus Magdeburg stammenden Apothekers Johannes Häringshauser geboren und starb 1642 in Mistelbach. Johannes Häringshauser Sen. bekleidete von 1613-1640 eine Reihe wichtiger Ämter in der Wiener Stadtregierung und starb 1647. Der Studienaufenthalt von Dr. Johannes Häringshauser Jun. in Padua (1624-1626) dürfte das Interesse für Astronomie geweckt haben, das sich in seiner in die Bestände der Melker Stiftsbibliothek eingegangenen Privatbibliothek widerspiegelt. Der Großteil der 10 dem Fachbereich der Astronomie und Astrologie zuzuweisenden Titel wurde von ihm in den Jahren 1636 und 1637 erworben.

  11. Edelgase als Tracer für Wechselwirkungen von Krusten- und Mantelfluiden mit diamantführenden Gesteinen des östlichen Baltischen Schildes

    NASA Astrophysics Data System (ADS)

    Wiersberg, Thomas

    2001-11-01

    In der vorliegenden Arbeit werden anhand der Edelgaszusammensetzung von Kimberliten und Lamproiten sowie ihrer gesteinsbildenden Minerale die Wechselwirkungen dieser Gesteine mit Fluiden diskutiert. Die untersuchten Proben stammen vom östlichen Baltischen Schild, vom Kola-Kraton (Poria Guba und Kandalaksha) und vom karelischen Kraton (Kostamuksha). Edelgasanalysen nach thermischer oder mechanischer Gasextraktion von 23 Gesamtgesteinsproben und 15 Mineralseparaten ergeben folgendes Bild: Helium- und Neon-Isotopendaten der Fluideinschlüsse von Lamproiten aus Kostamuksha lassen auf den Einfluss einer fluiden Phase krustaler Herkunft schliessen. Diese Wechselwirkungen fanden wahrscheinlich schon während des Magmenaufstiegs statt, denn spätere Einflüsse krustaler Fluide auf die Lamproite und ihr Nebengestein (Quarzit) sind gering, wie anhand der C/36Ar-Zusammensetzung gezeigt wird. Auch sind die mit verschiedenen Datierungsmethoden (Rb-Sr, Sm-Nd, K-Ar) an Mineralseparaten und teilweise an Gesamtgestein ermittelten Alter konsistent und machen eine metamorphe Überprägung unwahrscheinlich. Aufgrund der Verteilung der primordialen Edelgasisotope zwischen Fluideinschlüssen und Gesteinsmatrix ist ein langsamer Magmenaufstieg anzunehmen, was die Möglichkeit der Kontamination mit einem krustalen Fluid während des Magmenaufstiegs erhöht. Die Gasextraktion aus Mineralseparaten erfolgte thermisch, wodurch eine Freisetzung der Gase ausschließlich aus Fluideinschlüssen nicht möglich ist. Hierbei zeigen Amphibol und Klinopyroxen, separiert aus Kostamuksha-Lamproiten, in ihrer Neon-Isotopenzusammensetzung im Vergleich zur krustalen Zusammensetzung (Kennedy et al., 1990) ein leicht erhöhtes Verhältnis von 20Ne/22Ne, was ein Hinweis auf Mantel-Neon sein könnte. Kalifeldspäte, Quarz und Karbonate enthalten dagegen nur Neon krustaler Zusammensetzung. Phlogopite haben sehr kleine Verhältnisse von 20Ne/22Ne und 21Ne/22Ne, zurückzuführen auf in-situ-Produktion von 22Ne

  12. In Close Association: Research, Humanities, and the Library. Buch, Bibliothek, und Geisteswissenschaftliche (The Book, the Library, and Research in the Humanities). Occasional Papers No. 208.

    ERIC Educational Resources Information Center

    Fabian, Bernhard

    Based on Bernhard Fabian's "Buch, Bibliothek, und geisteswissenschaftliche Forschung (The Book, the Library, and Humanistic Research)," this study is a commentary on the relationship between library and user. Discussing the characteristics and requirements of research in the humanities, it stresses the interrelationship between…

  13. 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

  14. Reaktive Tracer zur Bestimmung der sedimentären Aquifer-Oxidationskapazität im Labor- und Feldversuch

    NASA Astrophysics Data System (ADS)

    Dethlefsen, Frank; Bliss, Fabian; Wachter, Thorsten; Dahmke, Andreas

    Kurzfassung Mikrobiell reduzierbares Eisen(III) im Aquifer kann als Elektronenakzeptor von großer Bedeutung für Natural Attenuation (NA) von aromatischen Kohlenwasserstoffen sein und bildet den Hauptbestandteil der sedimentären Oxidationskapazität (OXC) des Aquifers. Untersuchungsgegenstand war der Vergleich traditioneller, nasschemischer Methoden mit neuentwickelten, reaktiven Tracerverfahren zur Bestimmung der sedimentären OXC. Die innovativen Tracermethoden haben gegenüber nasschemischen Extraktionsverfahren den prinzipiellen Vorteil, dass sie einen integralen Ansatz zur Bestimmung der sedimentären OXC bilden, weil geochemische und hydraulische Heterogenitäten des Aquifers berücksichtigt werden. Daher wurden am RETZINA-Standort Zeitz einerseits herkömmliche Säure-Extraktionsmethoden (bestimmter Eisen(III)-Gehalt: 0,43 +/- 0,07 mg/g Aquifermaterial) und andererseits reaktive Tracertests mit Phosphat-(Eisen(III): 1,0 mg/g) und Sulfidtracern (Eisen(III): 0,31 +/- 0,02 mg/g) in Laborversuchen sowie Bioabbauversuche mit Toluol als Kohlenstoffquelle undGeobacter metallireducensals Eisen(III)-Reduzierer (Eisen(III): 1,0 mg/g) durchgeführt. Sulfid als reaktiver Tracer wurde in Form eines 〝Push-Pull-Tests`` im Feldversuch eingesetzt (Eisen(III): 1,1 mg/g). Zudem bedeutet die Anwendung des Feld-Tracerverfahrens deutlich weniger Zeitaufwand in der Durchführung als die Anwendung traditioneller Extraktionsmethoden. Microbially reducible iron(III) is important as a terminal electron acceptor for the Natural Attenuation (NA) of aromatic hydrocarbons and forms the balance of the aquifer's sedimentary oxidation capacity (OXC). It was the aim of this investigation to compare traditional acid extraction methods to reactive tracer methods in quantifying the sedimentary OXC. The sedimentary OXC at the RETZINA test site in Zeitz was therefore determined through traditional acid extraction methods (determined Iron(III)-content: 0.43 +/- 0.07 mg/g aquifer material) and

  15. Combined Therapy of Septicemia with Ofloxacin and/or Synthetic Trehalose Dicorynomycolate (S-TDCM) in Irradiated and Wounded Mice (Die Kombinierte Therapie der Septikaemie mit Ofloxacin und/oder Synthetischem Trehalose- Dicorynomycolat (S-TDCM) bei Bestrahlten und Verwundeten Maeusen)

    DTIC Science & Technology

    1989-01-01

    for effective therapy of polymicrobic infections in irradiated/wounded mice. ZUSAMMENFASSUNG Im Gefolge letaler Bestrahlung fallen MAuse normalerweise...durch die Inhalation von Methoxyfluran andsthetisiert wurden. Eine Stunde nach 8.0 G.- Germma- Bestrahlung wurden dorsal Haut- und Muskelgewebe in Ent

  16. Effekt einer ad libitum verzehrten fettreduzierten Kost, reich an Obst, Gemüse und Milchprodukten auf den Blutdruck bei Borderline-Hypertonikern

    NASA Astrophysics Data System (ADS)

    Möseneder, Jutta M.

    2002-01-01

    In der randomisierten, multizentrischen DASH-Studie (Dietary Approaches to Stop Hy-pertension), die unter kontrollierten Bedingungen stattfand, führte eine fettreduzierte Mischkost, reich an Obst, Gemüse und Milchprodukten, bei Borderline-Hypertonikern zu einer signifikanten Blutdrucksenkung. Während der Studienphase wurden Körpermasse, Natrium-Aufnahme sowie Alkoholzufuhr aufgrund der bekannten Einflussnahme auf den Blutdruck konstant gehalten. In der eigenen Pilot-Studie sollte untersucht werden, ob das Ergebnis der DASH-Studie (i) mit deutschen Hypertonikern und (ii) unter habituellen Ernährungs- und Lebensbedingungen mit regelmäßig durchgeführter Ernährungsberatung und ad libitum Verzehr anstelle des streng kontrollierten Studienansatzes bestätigt werden kann. Eine Konstanz der Körpermasse, der Natrium-Urinausscheidung (unter diesem Studienansatz valider als die Aufnahme) und des Alkoholkonsums wurde vorausgesetzt. Die Studienpopulation setzte sich aus 53 übergewichtigen Probanden mit einer nicht medikamentös therapierten Borderline-Hypertonie und ohne Stoffwechselerkrankungen zusammen. Die Studienteilnehmer wurden randomisiert entweder der Idealgruppe mit einer fettarmen Kost reich an Milchprodukten, Obst und Gemüse (ähnlich der DASH-Idealgruppe) oder der Kontrollgruppe mit habitueller Ernährungsweise zugeteilt. Über einen Zeitraum von fünf Wochen wurde den Probanden etwa 50% ihres täglichen Lebensmittelbedarfes entsprechend ihrer Gruppenzugehörigkeit kostenfrei zur Verfügung gestellt. Gelegenheitsblutdruckmessungen und 24h-Blutdruckmessungen, Ernährungs- und Aktivitätsprotokolle, Blut- und Urinproben sowie anthropometrische Messungen wurden vor, während und fünf Wochen nach der Interventionsphase durchgeführt. Die Ergebnisse zeigen, dass in der Idealgruppe keine signifikante Blutdrucksenkung beobachtet werden konnte. Dies lässt sich durch die Tatsache erklären, dass die Lebens-mittel- und Nährstoffaufnahme der deutschen

  17. Clustering effects in fusion evaporation reactions with light even-even N = Z nuclei. The {sup 24}Mg and {sup 28}Si cases

    SciTech Connect

    Morelli, L. D’Agostino, M.; Bruno, M.; Baiocco, G.; Gulminelli, F.; Cinausero, M.; Gramegna, F.; Marchi, T.; Degerlier, M.; Fabris, D.; Barlini, S.; Bini, M.; Casini, G.; Gelli, N.; Olmi, A.; Pasquali, G.; Piantelli, S.

    2015-10-15

    In the recent years, cluster structures have been evidenced in many ground and excited states of light nuclei [1, 2]. Within the currently ongoing experimental campaign by the NUCL-EX collaboration we have measured the {sup 12}C+{sup 12}C and {sup 14}N+{sup 10}B reactions at 95 MeV and 80 MeV respectively, and compared experimental data corresponding to complete fusion of target and projectile into an excited {sup 24}Mg nucleus to the results of a pure statistical model[3, 4]. We found clear deviations from the statstical model in the decay pattern: emission channels involving multiple α particles are more probable than expected from a purely statistical behavior. To continue the investigation on light systems, we have recentely measured the {sup 16}O+{sup 12}C reaction at three different beam energies, namely E{sub beam} = 90, 110 and 130 MeV.

  18. Introduction of a Diagnosis Related Groups’ Case Flat Rate System: Hopes and Fears (einfuerhrng eines drg-fallpauschalensystems - hoffnungen und aengste)

    DTIC Science & Technology

    2000-06-01

    GOnter Neubauer Universittt der Bundeswehr M(Jnchen Neuordnung der KrankenhausvergUtung 15 Gerhard Knorr Bayerisches Staatsministerium fOr Arbeit und...Erlbse zu stellen. Nur eine solche trans- parente Vorgehensweise wird auch der entsprechenden Sachlage gerecht. -10- Schr ~itt zu e1 in U411 duc...user gelten. Unterschiede in der Entgelthohe sind dabei nur sehr be- schr ~nkt m5glich: Zum einen, soweit es sich um Finanzierungstatbesttn- de handelt

  19. Direct Calculation of Short Circuit Reactance, Winding Strength, and Inherent Forms of Output Transformers (Direkte Berechung der Kurzschlussreaktanzen, Wicklungskraefte und Eigenformen von Leistungstransformatoren)

    DTIC Science & Technology

    2001-01-01

    1,2 Grundwehrdienst:. 06/1989-08/1990 1./PzArtBtl 335 in Dedelstorf Studium : 10/1990-11/1995 Studium der Physik an der TU Braunschweig Abschluss...ihre Anwendungen, Tell 2. Springer-Verlag Berlin Heidelberg New York, 1986. [10] Zurmfihl, Rudolf: Praktische Mathematik fir Ingenieure und Physiker ... Physik . Springer-Verlag Berlin Heidelberg New York, 1989. [261 HP MLIB User’s Guide. Hewlett Packard Company, 1999. 148 ABBILDUNGSVERZEICHNIS

  20. 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

  1. Friedrich Möglich - sein Beitrag zum Aufbau der Physik in der DDR. Friedrich Möglich - langjähriger Mitherausgeber und Chefredakteur der Annalen der Physik

    NASA Astrophysics Data System (ADS)

    Rompe, Robert

    Friedrich Möglich, ein Schüler von Max von Laue und Erwin Schrödinger, übernahm 1947 die Chefredaktion der Annalen der Physik.Translated AbstractFriedrich Möglich - His Contributions to the Formation of Physics in GDRFriedrich Möglich a student of Max von Laue and Erwin Schrödinger took over as editor in chief of Annalen der Physik in 1947.

  2. Versuche zur Gewinnung von katalytischen Antikörpern zur Hydrolyse von Arylcarbamaten und Arylharnstoffen. (English Title: Attempts to produce catalytic antibodies for hydrolysis of arylcarbamates and arylureas)

    NASA Astrophysics Data System (ADS)

    Werner, Deljana

    2002-05-01

    Im Rahmen dieser Arbeit gelang es, katalytische Antikörper zur Hydrolyse von Benzylphenylcarbamaten sowie zahlreiche monoklonale Antikörper gegen Haptene herzustellen. Es wurden verschiedene Hapten-Protein-Konjugate unter Verwendung unterschiedlicher Kopplungsmethoden hergestellt und charakterisiert. Zur Generierung der hydrolytisch aktiven Antikörper wurden Inzuchtmäuse mit KLH-Konjugaten von 4 Übergangszustandsanaloga (ÜZA) immunisiert. Mit Hilfe der Hybridomtechnik wurden verschiedene monoklonale Antikörper gegen diese ÜZA gewonnen. Dabei wurden sowohl verschiedene Immunisierungsschemata als auch verschiedene Inzuchtmausstämme und Fusionstechniken verwendet. Insgesamt wurden 32 monoklonale Antikörper gegen die verwendeten ÜZA selektiert. Diese Antikörper wurden in groen Mengen hergestellt und gereinigt. Zum Nachweis der Antikörper-vermittelten Katalyse wurden verschiedene Methoden entwickelt und eingesetzt, darunter immunologische Nachweismethoden mit Anti-Substrat- und Anti-Produkt-Antikörpern und eine photometrische Methode mit Dimethylaminozimtaldehyd. Der Nachweis der hydrolytischen Aktivität gelang mit Hilfe eines Enzymsensors, basierend auf immobilisierter Tyrosinase. Die Antikörper N1-BC1-D11, N1-FA7-C4, N1-FA7-D12 und R3-LG2-F9 hydrolysierten die Benzylphenylcarbamate POCc18, POCc19 und Substanz 27. Der Nachweis der hydrolytischen Aktivität dieser Antikörper gelang auch mit Hilfe der HPLC. Der katalytische Antikörper N1-BC1-D11 wurde kinetisch und thermodynamisch untersucht. Es wurde eine Michaelis-Menten-Kinetik mit Km von 210 µM, vmax von 3 mM/min und kcat von 222 min-1 beobachtet. Diese Werte korrelieren mit den Werten der wenigen bekannten Diphenylcarbamat-spaltenden Abzyme. Die Beschleunigungsrate des Antikörpers N1-BC1-D11 betrug 10. Das ÜZA Hei3 hemmte die hydrolytische Aktivität. Dies beweist, dass die Hydrolyse in der Antigenbindungsstelle stattfindet. Weiter wurde zwischen der Antikörperkonzentration und der

  3. Analysis of 6Li Scattering at 240 MeV Using Different Nuclear Potentials

    NASA Astrophysics Data System (ADS)

    Al-Ghamdi, A. H.; Ibraheem, Awad A.

    2016-06-01

    Angular distributions of the elastic and inelastic scattering cross sections of 6Li projectile on different heavy ion target nuclei including the 24Mg, 28Si, 48Ca, 58Ni, 90Zr, and 116Sn at energy of 240 MeV have been analyzed by using two different folded potentials based on the CDM3Y6 and São Paulo potentials for the real part of the optical potential, while the imaginary parts have a phenomenological Woods-Saxon shape. Coupled channel calculations for the low-lying 2+ state at 1.369, 1.779, 3.832, 1.454, 2.186, and 1.29 MeV for 24Mg, 28Si, 48Ca, 58Ni, 90Zr, and 116Sn, respectively, have been carried out, and the best fit values for B(EL) with the above models have been extracted by fitting the inelastic scattering cross section and compared with the values of previous works. The total reaction cross section and real and imaginary volume integrals have also been investigated.

  4. Amplituden der Kernphasen im Bereich der Kaustik B und Untersuchung der Struktur der Übergangszone zum inneren Erdkern mit spektralen Amplituden der diffraktierten Phase PKP(BC)

    NASA Astrophysics Data System (ADS)

    Wolf, Michael D. C.

    2002-04-01

    Das Ziel dieser Arbeit ist es, die Strukturen im äueren Erdkern zu untersuchen und Rückschlüsse auf die sich daraus ergebenden Konsequenzen für geodynamische Modellvorstellungen zu ziehen. Die Untersuchung der Kernphasenkaustik B mit Hilfe einer kumulierten Amplituden-Entfernungskurve ist Gegenstand des ersten Teils. Dazu werden die absoluten Amplituden der PKP-Phasen im Entfernungsbereich von 142 ° bis 147 ° bestimmt und mit den Amplituden synthetischer Seismogramme verglichen. Als Datenmaterial dienen die Breitbandregistrierungen des Deutschen Seismologischen Re-gionalnetzes (GRSN 1 ) und des Arrays Gräfenberg (GRF). Die verwendeten Wellen-formen werden im WWSSN-SP-Frequenzbereich gefiltert. Als Datenbasis dienen vier Tiefherdbeben der Subduktionszone der Neuen Hebriden (Vanuatu Island) und vier Nuklearexplosionen, die auf dem Mururoa und Fangataufa Atoll im Südpazifik stattgefunden haben. Beide Regionen befinden sich vom Regionalnetz aus gesehen in einer Epizentraldistanz von ungefähr 145 °. Die Verwendung eines homogen instrumentierten Netzes von Detektoren und die Anwendung von Stations- und Magnitudenkorrekturen verringern den Hauptteil der Streuung bei den Amplitudenwerten. Dies gilt auch im Vergleich zu Untersuchungen von langperiodischen Amplituden im Bereich der Kernphasenkaustik (Häge, 1981). Ein weiterer Grund für die geringe Streuung ist die ausschlieliche Verwendung von Ereignissen mit kurzer impulsiver Herdzeitfunktion. Erst die geringe Streuung der Amplitudenwerte ermöglicht eine Interpretation der Daten. Die theoretischen Amplitudenkurven der untersuchten Erdmodelle zeigen im Bereich der Kaustik B einen gleichartigen Kurvenverlauf. Bei allen Berechnungen wird ein einheitliches Modell für die Güte der P- und S-Wellen verwendet, das sich aus den Q-Werten der Modelle CIT112 und PREM 2 zusammensetzt. Die mit diesem Q-Modell berechneten Amplituden liegen in geringem Mae oberhalb der gemessenen Amplituden. Dies braucht nicht ber

  5. Herstellung eines federelastischen Spangutes geringer Dichte als Matrix für Schüttdämmstoffe, für plattenförmige Dämmstoffe und leichte Spanplatten

    NASA Astrophysics Data System (ADS)

    Tröger, Johannes; Groß, Lucia

    Klimaschutz und die ständig steigenden Energiekosten erfordern eine kontinuierliche Verbesserung der Dämmstoffe. Eine Alternative zur relativ kostenaufwändigen Wärmedämmung durch Platten bzw. Matten auf Basis von mineralischen Stoffen, ist der Einsatz von schütt-bzw. einblasbaren Dämmstoffpartikeln. Späne aus Holz und andere Dämmstoffe aus nachwachsenden Rohstoffen waren schon vor dem ersten Weltkrieg die gebräuchlichsten Dämmstoffe überhaupt. Seit etwa fünfzehn Jahren werden u.a. für den Holzhausbau im zunehmenden Maße auch Fräs-, Säge und Hobelspäne für Wärmedämmzwecke eingesetzt [1], [2], [3]. Hervorzuheben ist der ökologische Aspekt dieser Dämmstoffe durch die Bindung von CO2 und den sinkenden Heizenergiebedarf. Die bisherige Philosophie bei der Gewinnung von Dämmstoffspänen beruhte darauf, anfallendes Spangut stofflich weiter zu nutzen. Die Recyclingspäne sollten dabei sowohl die Setzungssicherheit als auch eine möglichst gute Wärmedämmung gewährleisten.

  6. The dating of the ornithological section of Middendorff's Reise in den äussersten Norden und Osten Sibiriens, with comments on the nomenclature of Pallas's Bunting Emberiza pallasi Cabanis (Aves: Emberizidae).

    PubMed

    Mlíkovský, Jiří

    2014-05-14

    Middendorff's work on the Säugethiere, Vögel und Amphibien, published as part 2 of volume 2 of his Reise in den äussersten Norden und Osten Sibiriens, was variably dated from 1851, 1852 or 1853. I document that the work was published shortly before 15 December 1852 and I recommend using this date for the purposes of zoological nomenclature.Due to this, Emberiza polaris Middendorff, 1852 has precedence over Cynchramus pallasi Cabanis, 1853. This bunting species thus should be called Emberiza polaris and its four subspecies should be called Emberiza polaris polaris Middendorff, 1852, E. polaris minor Middendorff, 1852, E. polaris pallasi (Cabanis, 1853) and E. polaris lydiae Portenko, 1929. 

  7. Peter Andreas Hansen and the astronomical community - a first investigation of the Hansen papers. (German Title: Peter Andreas Hansen und die astronomische Gemeinschaft - eine erste Auswertung des Hansen-Nachlasses. )

    NASA Astrophysics Data System (ADS)

    Schwarz, Oliver; Strumpf, Manfred

    The literary assets of Peter Andreas Hansen are deposited in the Staatsarchiv Hamburg, the Forschungs- und Landesbibliothek Gotha and the Thüringer Staatsarchiv Gotha. They were never systematically investigated. We present here some results of a first evaluation. It was possible to reconstruct the historical events with regard to the maintenance of the Astronomische Nachrichten and the Altona observatory in 1854. Hansen was a successful teacher for many young astronomers. His way of stimulating the evolution of astronomy followed Zach's tradition.

  8. Frauen, Bildung und Entwicklung

    NASA Astrophysics Data System (ADS)

    Nestvogel, Renate

    1987-12-01

    The author presents first steps towards a development-based concept of women's education in the industrialized countries. Some elements of this concept are: (1) planning and action in a global context, (2) the local or regional bias given to education, (3) promotion of an intercultural perspective, (4) reducing the power of structures that encourage oppression. The author's observations are based on the following propositions: the `development process' in the industrialized countries has had terrible effects all over the world and it is necessary that women also consider their roles in what the author considers to be a process of destruction. This is because women are part of the overall system and contribute to its perpetuation in the measure of their own socialization. Connections are established between the destruction of the environment and the individual, as also between the victims and assailants of racism and sexism with a view to clarifying unidentified parts of the female consciousness. Beyond this, the role of European women in the context of colonialism and the present contact between European women and their counterparts from other cultures are examined with particular attention being paid to the exercise of power and force in the family and society.

  9. Geschlechtsbestimmung und Geschlechtsdifferenzierung

    NASA Astrophysics Data System (ADS)

    Drews, Ulrich

    1981-04-01

    Sex determination in mammals proceeds like a cascade from the level of the sex chromosomes to the gonads, to the genital ducts, and finally to the expression of the male or female phenotype. At the level of the genital ducts male sex organs are induced by testosterone. Its action depends on an intact cytoplasmic androgen receptor protein. The testicular feminization mutation ( Tfm) leads to loss of hormone binding capacity. Individuals with testes but female external phenotype develop. In the mouse the interaction of androgen insensitive Tfm cells with normal cells can be studied in mosaic individuals composed of both cell types, and in organ culture by recombination of Tfm and normal tissues. The experiments show that under the action of testosterone the normal cells express male differentiated cellular functions, whereas the Tfm cells differentiate in female direction. In respect to proliferation and expression of male or female organ structures, however, both cell types communicate via local factors. Thus, instead of irregular malformations intersex organs develop.

  10. Orientierungskonzepte: Geschichtliches und Aktuelles

    NASA Astrophysics Data System (ADS)

    Schöne, Hermann

    1983-07-01

    The development of some conceptions of simple orientation mechanisms is shown, some complex systems are described. Conceptions which emphasize the stimulus reception like bilateral comparison principles (tropism, tropotaxis, bisensor procedure, unisensor procedure, menotaxis, klinotaxis), topological principles (telotaxis, array procedure), idiothetic orientation and indirect orientation (phobotaxis, kinesis) are investigated. Conceptions which emphasize the stimulus-reaction relationship like taxis, reafference principle and feedback control systems as well as mechanisms like chart and compass, vector integration, vector navigation, landmark orientation and goal finding procedures which can be subsumed under the concept of navigation are described.

  11. Korallen, Fischer und Touristen

    NASA Astrophysics Data System (ADS)

    Kunzmann, Andreas

    1999-12-01

    As a result of natural and anthropogenic disturbances, coral reefs are endangered across the world. This presentation addresses the effects of fishing and tourism on coral reefs. Although reefs are important in a global context for fisheries and tourism, more than 60% of all reefs are endangered through human activities. The use of explosives and poison for fishing is banned since 1972. Nevertheless, up to 50% of small-scale fishermen use bombs and poison, at least temporarily. Both methods cause long-term destruction of corals and reef structure leaving behind only coral rubble or rather mile-long “coral cemeteries” whose assertion of skeletal dead corals are a sad reminder of the beautiful reefs before the destruction. The trade with ornamental fish for aquarium and live reef fish for consumption in Hongkong is worth more than 1 billion US annually. Uncontrolled tourism also destroys reefs in many ways—rapid coastal development with corals as building material, sedimentation, eutrophication and last not least many divers disturb coral reefs. This is also true for the blooming trade with souvenirs from the sea, where, as is the case for ornamental fish trade, the Philippines are the main export nation. In addition, natural disturbance factors such as climatically induced temperature variations or storms frequently act as the final straw for already stressed reefs. Fortunately, the number of marine parks and marine protected areas is increasing worldwide and several large international projects for reef protection and rehabilitation have begun. It remains to be seen whether decision-makers will discover that reefs which are managed in an encompassing and sustainable manner can provide economically viable returms. It must be realised that in order to achieve this, developing countries in the tropics must be substantially supported with true partnership projects.

  12. Total and partial capture cross sections in reactions with deformed nuclei at energies near and below the Coulomb barrier

    SciTech Connect

    Kuzyakin, R. A. Sargsyan, V. V.; Adamian, G. G.; Antonenko, N. V.

    2013-06-15

    Within the quantum diffusion approach, the capture of a projectile nucleus by a target nucleus is studied at bombarding energies above and below the Coulomb barrier. The effects of deformation of interacting nuclei and neutron transfer between them on the total and partial capture cross sections and the mean angular momentum of the captured system are studied. The results obtained for the {sup 16}O + {sup 112}Cd, {sup 152}Sm, and {sup 184}W; {sup 19}F +{sup 175}Lu; {sup 28}Si +{sup 94,100}Mo and {sup 154}Sm; {sup 40}Ca +{sup 96}Zr; {sup 48}Ca+ {sup 90}Zr; and {sup 64}Ni +{sup 58,64}Ni, {sup 92,96}Zr, and {sup 100}Mo reactions are in good agreement with available experimental data.

  13. Capture process in nuclear reactions with a quantum master equation

    SciTech Connect

    Sargsyan, V. V.; Kanokov, Z.; Adamian, G. G.; Antonenko, N. V.; Scheid, W.

    2009-09-15

    Projectile-nucleus capture by a target nucleus at bombarding energies in the vicinity of the Coulomb barrier is treated with the reduced-density-matrix formalism. The effects of dissipation and fluctuations on the capture process are taken self-consistently into account within the quantum model suggested. The excitation functions for the capture in the reactions {sup 16}O, {sup 19}F, {sup 26}Mg, {sup 28}Si, {sup 32,34,36,38}S, {sup 40,48}Ca, {sup 50}Ti, {sup 52}Cr+{sup 208}Pb with spherical nuclei are calculated and compared with the experimental data. At bombarding energies about (15-25) MeV above the Coulomb barrier the maximum of capture cross section is revealed for the {sup 58}Ni+{sup 208}Pb reaction.

  14. [Carl Gustav Jung's Theatrum Mundi. Can the description of modern alchemy in Jung's Psychologie und Alchemie be really regarded as a historical reconstruction?].

    PubMed

    Płonka-Syroka, B

    2000-01-01

    In his work, Psychologie und Alchemie, published in 1944, Jung wanted to present a reconstruction of alchemy. In order to do this he used a method of psychology, which he modified and enriched with inspirations drawn from neo-romantically-oriented German medical historiographies of the nineteen thirties. Using historical materials, he intended to demonstrate the empirical character of his Depth Psychology, a widespread concept, ingrained in our supra-personal social unconscious. The present article questions the nature of Jung's reconstruction of alchemy as historical reconstruction. The author presents the methodological bases referred to by Jung derived from his concept of medical practice and compares them with a manner of thinking typical of contemporary historical analysis. The article also presents Jung's inspirations from the medical historiography of his time, as well as the dissimilarity of his concept with the model of historical narrative construction in force in the historiography of the thirties and forties. At the same time, it presents the elements of the "romantic inheritance" in Jung's thought, drawn from the tradition of German non-materialistic medicine of the first half of the nineteenth century.

  15. THE PROFITS AND PERILS OF PUBLICITY: ALLGEMEINE LITERATUR- ZEITUNG, THE THURN UND TAXIS POST, AND THE PERIODICAL TRADE AT THE END OF THE EIGHTEENTH CENTURY.

    PubMed

    Broman, Thomas

    2015-09-20

    Recent historiography on the growth of periodical publishing has emphasized newspapers and journals as constituents of an emergent communications system in early modern Europe. This system comprised the newspapers, journals and other publications that contributed its content, and also the postal systems that were the principal method of distributing that content. This article describes how the growth of this system in central Europe was supported in large measure by financial incentives that it offered to both constituents. First, in contrast with postal systems in France and the UK, the Thurn und Taxis Reichspost inserted itself as a middleman in the sale of periodicals, which gave the Reichspost an incentive to promote the trade. Second, the financial conditions for periodical publication made their costs depend more heavily on costs that were scalable to circulation than is true today, which resulted in the viability of publications with a lower circulation. The same cost structure also made it possible for certain prominent periodicals of the era to earn considerable profits for their publishers, as illustrated in this article by Allgemeine Literatur-Zeitung, which was published in Jena from 1785.

  16. The profits and perils of publicity: Allgemeine Literatur-Zeitung, the Thurn und Taxis Post, and the periodical trade at the end of the eighteenth century

    PubMed Central

    Broman, Thomas

    2015-01-01

    Recent historiography on the growth of periodical publishing has emphasized newspapers and journals as constituents of an emergent communications system in early modern Europe. This system comprised the newspapers, journals and other publications that contributed its content, and also the postal systems that were the principal method of distributing that content. This article describes how the growth of this system in central Europe was supported in large measure by financial incentives that it offered to both constituents. First, in contrast with postal systems in France and the UK, the Thurn und Taxis Reichspost inserted itself as a middleman in the sale of periodicals, which gave the Reichspost an incentive to promote the trade. Second, the financial conditions for periodical publication made their costs depend more heavily on costs that were scalable to circulation than is true today, which resulted in the viability of publications with a lower circulation. The same cost structure also made it possible for certain prominent periodicals of the era to earn considerable profits for their publishers, as illustrated in this article by Allgemeine Literatur-Zeitung, which was published in Jena from 1785. PMID:26495577

  17. Gemeinsame Aspekte und Probleme in Physik und Geologie

    NASA Astrophysics Data System (ADS)

    Watznauer, A.

    Die griechische Naturphilosophie, vor allem Aristoteles, verstand unter Physik die Naturwissenschaft in toto. Die Aufspaltung dieser universellen Naturphilosophie in Fachdisziplinen betrifft sowohl den Gegenstand als auch, daraus abgeleitet, die Methodik der Darstellung. Die Physik, deren Gegenstand seit Galilei die reinen Fälle sind, ist ahistorisch. Die Geologie, die komplexe Systeme untersucht, ist dagegen eine historische Wissenschaft.Translated AbstractCommon Aspects and Problems in Physics and GeologyThe greek philosophers and above all Aristotle thougt in the physics about nature in toto. The splitting of this philosophy of nature into different sciences concerns both their topics and their methods. Since Galilei physics is concerned with pure cases, being an ahistorical science. On the contrary geology examines complex systems, being of historical character.

  18. Archaebakterien und Phylogenie der Organismen

    NASA Astrophysics Data System (ADS)

    Kandler, Otto

    1981-04-01

    The determination of the sequence similarity of the ribosomal 16 S RNA of many bacteria and a few higher organisms has shown that the methanogenic, halophilic, and acido-thermophilic organisms are phylogenetically separated from the kingdoms of the Eubacteria and Eukaryotes thus representing a third kingdom called “Archaebacteria”. Many biochemical and molecular biological features support this conclusion.

  19. Führungs- und Teamverhalten

    NASA Astrophysics Data System (ADS)

    Ebermann, Hans-Joachim; Scheiderer, Joachim

    Mc. Broom war ein tyrannischer Chef, der seine Mitarbeiter mit seiner Launenhaftigkeit einschüchterte. Das wäre vielleicht nicht aufgefallen, hätte Mc. Broom in einem Büro oder in einer Fabrik gearbeitet. Aber Mc. Broom war Flugkapitän. <¼> Seine Copiloten fürchteten sich so sehr vor seinem Zorn, dass sie nichts sagten. Nicht einmal als die Katastrophe absehbar war. Beim Absturz der Maschine kamen zehn Menschen zu Tode (Goleman 2001).

  20. Shaping the System – The DRG Evaluation Project of the German Society for Gynaecology and Obstetrics (Deutsche Gesellschaft für Gynäkologie und Geburtshilfe, DGGG)

    PubMed Central

    Fiori, W.; Renner, S. P.; Siam, K.; Babapirali, J.; Roeder, N.; Dausch, E.; Hildebrandt, T.; Hillemanns, P.; Nehmzow, M.; Zygmunt, M.; Piroth, D.; Schem, C.; Schwenzer, T.; Friese, K.; Wallwiener, D.; Beckmann, M. W.

    2013-01-01

    Introduction: The German DRG system is annually adapted to the changing services provided. For the further development, the self-governing body and its DRG Institute (InEK) depend on participation of the users. Methods: For one of the DRG evaluation projects initiated by DGGG, cost and performance data for the year 2011 from 16 hospitals were available. After plausibility checks and corrections, analyses for service and cost homogeneity were performed. In cases of inadequate DRG-representation attributes were sought that would make an appropriate reimbursement possible. Conspicuities and potential solutions were checked for clinical plausibility. Results: 44 concrete modification proposals for further development of the G-DRG system were formulated and submitted in due time to the InEK. In addition, 3 modification proposals were addressed to the German Institute for Medical Documentation and Information (Deutsches Institut für Medizinische Dokumentation und Information, DIMDI) for further development of the diagnosis classification ICD-10-GM. For all modification proposals care was taken to minimise misdirected incentives and to reduce the potential for disputes with the cost bearers and their auditors services in settlements. Discussion: The publication of the G-DRG system 2014 shows which modification proposals have been realised. Essentially, an appropriate redistribution of the resources among the gynaecological and obstetrics departments is to be expected. The financial pressure that is caused by the generally inadequate financing of hospitals will not be reduced by a further development of the G-DRG system. PMID:24771931

  1. Vergleichende Ultrastrukturuntersuchungen der Eu- und Paraspermien von 13 Protodrilus-Arten (Polychaeta, Annelida) und ihre taxonomische und phylogenetische Bedeutung

    NASA Astrophysics Data System (ADS)

    von Nordheim, Henning

    1989-06-01

    The morphology of the slender, filiform spermatozoa of 13 Protodrilus species of 22 different populations is investigated by light and transmission electron microscopy. All species have two types of spermatoza: fertile euspermatozoa, and paraspermatozoa, which are probably infertile and may comprise up to 20% of the total number of mature gametes. This is the first record of sperm dimorphism in polychaetes. The general construction pattern of the euspermatozoa is very complex. It shows a longish tapering acrosomal vesicle with an internal acrosomal rod, a rod-like conical nucleus, and a midpiece with numerous very complex supporting elements and two thin mitochondrial derivatives. Further, it has a ‘peribasal body’ surrounding the basal body of the axoneme, an anulus region with an ‘anchoring apparatus’ and an anulus cuff. Posteriorly, the tail region proper contains in some species 2 to 9 supporting rods. In several species the euspermatozoon shows very distinct and species-specific alternations of this ‘general pattern’ relating to e.g. size of sperm elements, structure of acrosome and nucleus, presence or absence of axial rod, and number, shape and size of supporting elements in midpiece and tail. In a number of species some sections of the euspermatozoon overlap with each other more or less strongly. The paraspermatozoon has a comparatively simple construction pattern and possesses no supporting structures in midpiece and tail region. The midpiece is very short and, in some species, entirely surrounded by its two thin and elongate mitochondrial derivatives. An axial rod is often missing or reduced; different sperm sections never overlap each other. In contrast to the euspermatozoa, the paraspermatozoa of the different species have a very similar ultrastructure. Their possible function in spermatophore transfer and histolytical opening of the female epidermis is discussed. A comparison of the different forms of euspermatozoa in Protodrilus elucidates possible plesiomorphous and apomorphous sperm traits. Very likely, the hypothetical plesiomorphous type of spermatozoa in Protodrilus has a very similar morphology to that of the paraspermatozoa, which for this reason are considered to be a sort of persisting representatives of the ancient Protodrilus sperm type. In Protodrilus, the different traits of the euspermatozoa represent excellent taxonomic characters for distinguishing species (e.g. ‘sibling species’). They can also be used well for phylogenetics within the genus, whereas the relations of Protodrilus to other polychaete groups cannot be clarified solely on the basis of sperm characters, since in all groups the sperm structure is primarily an adaptation to a specific mode of reproduction. Generally, the value of sperm characters in phylogenetic considerations at higher taxonomic levels seems to be very limited due to the surprisingly wide range of different sperm structures within a single genus as is demonstrated in the present paper.

  2. Ermüdungs- und Wachsamkeitsmanagement

    NASA Astrophysics Data System (ADS)

    Ebermann, Hans-Joachim; Murtha, Maria-Pascaline

    1994 wurde erstmals Ermüdung (Fatigue) durch die amerikanische Unfalluntersuchungsbehörde NTSB (National Transportation Safety Board) offiziell als Hauptursache für einen Unfall in der Luftfahrt erklärt. Seitdem wird Müdigkeit bei der Untersuchung von Unfällen systematisch abgefragt.

  3. Zur Biosynthese von Phenylalanin und Tyrosin

    NASA Astrophysics Data System (ADS)

    Lingens, F.; Keller, E.

    1983-03-01

    With the discovery of arogenic acid two new pathways for the biosynthesis of phenylalanine and tyrosine have been revealed. The occurrence of two, three, or four pathways for the biosynthesis of phenylalanine and tyrosine in microorganisms and plants may be a useful tool for taxonomic classifications. Investigations on enterobacteriaceae, pseudomonads, flavobacteria, streptomycetes, archaebacteria, and on Sphaerotilus, Trichococcus and Leptothrix species from bulking sludge are described. The possible role of arogenate in the evolution of the pathways for tyrosine and phenylalanine biosynthesis is discussed.

  4. Zusatz- und Weiterqualifikation nach dem Studium

    NASA Astrophysics Data System (ADS)

    Domnick, Ivonne

    Ist der Bachelor geschafft, stellt sich die Frage nach einer Weiterqualifizierung. Neben einem Einstieg ins Berufsleben kann auch ein Masterstudium eventuell weitere entscheidende Bonuspunkte für den Lebenslauf bringen. Mit Zusatzqualifikationen aus fachfremden Bereichen wie Betriebswirtschaft oder Marketing ist es für Naturwissenschaftler leichter, den Einstieg ins Berufsleben zu schaffen. Viele Arbeitgeber sehen gerade bei Naturwissenschaftlern eine Promotion gerne. Hier sollte genau abgewogen werden, ob sie innerhalb einer bestimmten Zeitspanne zu schaffen ist. Auch nach einem Einstieg in den Job lässt sich der Doktortitel unter Umständen noch nachholen. Ebenso ist eine Weiterbildung neben dem Beruf in Teilzeit oder in einem Fernkurs möglich. Zusätzlich gibt es viele mehrwöchige oder mehrmonatige Kurse privater Anbieter, in denen man BWL-Grundkenntnisse erwerben kann.

  5. Astronomische Konzepte und Jenseitsvorstellungen in den Pyramidentexten.

    NASA Astrophysics Data System (ADS)

    Krauss, R.

    The Egyptian pyramid texts were first written down around 2300 B.C. They are based on the religious belief in a stellar hereafter and contain the astronomical knowledge of their authors. For example, the ecliptical belt was understood as a canal, on which moon and planets cruise; of the latter Mercury, Venus and Mars were identified. On the basis of their visibility in the course of a year the fixed stars were divided into two groups; a southern group with a period of invisibility and a northern group with continual visibility. The ecliptical "canal" was correctly identified as a division line between the two groups of fixed stars. The aim of this book is to bring these texts foreward to a better understanding of their astronomical background.

  6. Internationale Schulreformtendenzen und das Problem der Lehrerausbildung

    NASA Astrophysics Data System (ADS)

    Kupisiewicz, Czeslaw

    1982-09-01

    The main theme of this article is that the socio-economic and educational changes which have occurred in industrialized countries in the past 20 to 25 years necessitate a thorough reform of the present system of teacher education. The first group of such changes includes the information explosion, greater occupational mobility, the growing significance and increasing role of the sciences, the development of the mass media, higher educational aspirations, technical development, the acceleration of the psycho-physical development of children and youth, and the injurious effects of the uncontrolled development of the constantly changing civilisation (deterioration of the human environment, diseases caused by the effects of civilisation, etc.). In the face of these changes, teachers must not remain indifferent and teacher education systems have to take them into account. Within the second group of changes influencing the content and methods of teacher education, the most important is the generalisation of education at the pre-school, primary and secondary school levels and also at the university level. As a result, education in many types of school and at ever higher levels has lost the elitist character it still had, not so long ago, and has become a mass activity. This has considerably affected teachers' work and, necessarily, also the work of the teacher education systems. In present-day schools it is necessary to emphasize not only the transmission of knowledge of the `know that' type, as was done in the past, but also problem-solving, independent individual and group work, etc., which will enable children and young people to acquire `know-how' and `know-why'. This must also be reflected in teacher education. In order to adapt the teacher education systems to the requirements of the changing society, a reform of the goals, contents and methods of the system will have to be prepared and implemented as a prerequisite and starting point for a global reform of the entire education system.

  7. Uniform National Discharge Standards (UNDS): Rulemaking Process

    EPA Pesticide Factsheets

    The EPA and Department of Defense used a batch rulemaking process for establishing the discharge standards for vessels of the Armed Forces. They identified and evaluated the discharges and determined which require marine pollution control devices.

  8. PISA und Allgermeinbildung (PISA and General Education).

    ERIC Educational Resources Information Center

    Messner, Rudolf

    2003-01-01

    Examines the relationship between Program for International Student Assessment (PISA) and general education. Explains the socially grounded demands of the PISA literacy approach and its importance in basic education. Points out PISA's limitations. Argues that if PISA is misunderstood, schools and instruction may be restricted in content and social…

  9. Laser assisted Drug Delivery: Grundlagen und Praxis.

    PubMed

    Braun, Stephan Alexander; Schrumpf, Holger; Buhren, Bettina Alexandra; Homey, Bernhard; Gerber, Peter Arne

    2016-05-01

    Die topische Applikation von Wirkstoffen ist eine zentrale Therapieoption der Dermatologie. Allerdings mindert die effektive Barrierefunktion der Haut die Bioverfügbarkeit der meisten Externa. Fraktionierte ablative Laser stellen ein innovatives Verfahren dar, um die epidermale Barriere standardisiert, kontaktfrei zu überwinden. Die Bioverfügbarkeit im Anschluss applizierter Externa wird im Sinne einer laser assisted drug delivery (LADD) signifikant gesteigert. Das Prinzip der LADD wird bereits in einigen Bereichen der Dermatologie erfolgreich eingesetzt. Die vorliegende Übersichtsarbeit soll einen Überblick über die aktuellen aber auch perspektivischen Einsatzmöglichkeiten der LADD bieten.

  10. Verhalten und Neurobiologie von stimmbegabten Insekten

    NASA Astrophysics Data System (ADS)

    Huber, Franz

    1992-09-01

    Crickets, tettigoniids (bush crickets or long-horned grasshoppers) and acridids (short-horned grasshoppers) are well-suited animals to study acoustically mediated behavior and to search for the underlying sensory, nervous, and effector mechanisms. Several behavioral tactics are described which improve reproductive success, serve to avoid predators such as bats, or have been developed for defence against parasitic insects. Phonotactic orientation of female crickets toward the calling male was chosen, since for this behavior the underlying sensory and nervous mechanisms have been intensively studied. Song recognition was found to be based on one critical parameter of the song, the syllable period, and the females show a bandpass behavior for which a correlate exists in local brain neurons. Sound orientation is based on a pressure gradient mechanism in each ear, and it needs a binaural intensity comparison within the central nervous system. With intracellular recordings from auditory interneurons during phonotactic orientation and their manipulation, a cellular correlate could be found which obeys the rule “ turn to the side most strongly stimulated”.

  11. Helgoland und die Erforschung der marinen Benthosalgen

    NASA Astrophysics Data System (ADS)

    Mollenhauer, D.; Lüning, K.

    1988-09-01

    Early phycological research on the island of Helgoland was performed by amateur phycologists from the adjacent coastal regions of Germany (Bremen, Hamburg, Lower Saxony and Schleswig-Holstein). These pioneers were followed by professionals, and by collectors from the mainland universities, particularly from Berlin. This second phase group includes the naturalist Christian Gottfried Ehrenberg, the zoologists Johannes Müller, Ernst Haeckel and Anton Dohrn, and the botanists Alexander Braun, Nathanael Pringsheim, and Ferdinand Cohn. The leading marine phycologist in Germany, towards the end of the 19th century, was Johannes Reinke, who finally worked at the University of Kiel. Paul Kuckuck's doctoral thesis had been supervised by Reinke who recommended him for the post of the first curator of botany at the Biological Station of Helgoland, which was founded in 1892. Kuckuck worked on the island from 1892 to 1914. After World War I, and after Kuckuck's untimely death, Wilhelm Nienburg became the second curator of botany on Helgoland, from 1921 to 1923. The next permanent phycologist on the island, from 1925 to 1936, was Ernst Schreiber. He was followed in 1936 by Peter Kornmann, who retired in 1972 but still continues as a research worker, together with Paul-Heinz Sahling, who started to work as a technical assistant under the guidance of Ernst Schreiber in 1927.

  12. BOOK REVIEW: "...eine ausnehmende Zierde und Vortheil"

    NASA Astrophysics Data System (ADS)

    Duerbeck, H. W.; Luehning, F.

    This book comprises the habilitation thesis submitted by F. Lühning to the Faculty of Mathematics of Hamburg University in 2004. Due to financial support from various organizations, it was issued in a very attractive form as a special publication of the Society for the history of the city of Kiel. The nice layout, the graphical sketches of buildings, instruments, and astronomical connexions, often designed by the author, and the scientifically precise text, written with a sense of humor, make a pleasant reading, in spite of sometimes quite extensive descriptions of architectural details or 'operating instructions' for meridan circles etc. I have rarely read such an appealing text on astronomical history. The single chapters deal with the beginnings of astronomy in Kiel (1770-1820), Schrader's giant telescope from the late 18th century, Altona Observatory (1823-1850), the first years of the Astronomische Nachrichten, the last years of Altona Observatory (1850-1872), Bothkamp Observatory (1870-1914), the genesis of Kiel Observatory (1874-1880), the era of Krueger (1880-1896), the Kiel Chronometer Observatory (1893-1913), the era of Harzer (1897-1925), the era of Rosenberg (1927-1934), the decline of Kiel Observatory (1935-1950), and the Astronomische Nachrichten under Kobold (1907-1938). The book is concluded with a glossary of technical terms, biographical sketches of known and unknown dramatis personae, as well as a list of references. The author outlines lively sketches of people that were astronomically active in Altona, Kiel and its surroundings over a time interval of 200 years. To achieve this task, he has studied many files from the Secret State Archive Preussischer Kulturbesitz (Berlin), the Schleswig-Holsteinisches State Archive (Schleswig) and the Hamburg State Archive, from which he quotes extensively. He also has evaluated private documents and has interviewed surviving witnesses of the 1930s and 1940s. He has located remote sources: for example, the son of the founder of the Astronomische Nachrichten, Richard Schumacher, served for some years as an assistant at the Chilean National Observatory, and had married Marie Bulling, a girl of German descent. From her "meagre diary entries" of that time (published in Valparaiso in 2004), the author suspects a "convenience marriage''. Nevertheless, unreliable sources can provide a false picture: the interviewed custodian notes that the wife of the last official observatory director, Hans Oswald Rosenberg, was "Verena Borchardt, a Jewess from St. Petersburg'' (p. 583). This is more than incorrect. The family lived for some years in Moscow (not St. Petersburg), because her father was a representative of various companies, especially his grand-father's Königsberger Thee-Compagnie. In 1880, his daughter Helene was born there - who later married the Kiel astronomer Wirtz. In 1882, the Borchardt family moved to Berlin, where the father became a banker, and where Verena was born. The family was "of reformed confession, of Jewish origin'' (Borchardt, Heymel, Schörder: Marbacher Katalog Nr. 29, 1978): she was "a Jewess'' in Nazi terminology only. On page 583 too, Wirtz' capricious political views are quoted: "The day when the French troops entered Strasbourg was the happiest one in my life'', for which Theiss' paper of 1999 is quoted, and it is stated "source not given''. Now, Theiss uses a study of Duerbeck and Seitter (1990), where the precise reference in the Kiel Acta is given. Another overlooked (although not very informative) source is the voluminous edition of the collected letters (München 1994-2002) of Rudolf Borchardt, the poetical brother of "Vera'' Rosenberg and "Lene'' Wirtz. Another series of peculiar statements refer to the Astronomische Nachrichten (p. 666): Neither did they publish, after 1945, "sometimes only Russian articles'', nor after 1983 "only articles in English'': some "German'' astrometric articles appeared after that year, which will presumably stand the test of time better than the plethoria of "English'' articles, dealing mainly with cosmology. Totally fabricated is the author's statement that the journal is now published by "the Astronomical Computing Centre [sic] in Heidelberg''. In spite of these slightly critical notes on some irrelevant details, I can wholeheartedly recommend this book: it is an indispensable source of information for anyone who is interested in the history of astronomy in German-speaking lands in the 19th and the first half of the 20th century.

  13. Research into Distance Education = Fernlehre und Fernlehrforschung.

    ERIC Educational Resources Information Center

    Holmberg, Borje, Ed.; Ortner, Gerhard E., Ed.

    The papers (from a symposium held at the Fern Universitat) included in this collection focus on distance education in theory and practice. Contributions are written in English or in German, with summaries available for each in the language not used for the paper concerned. Contributions are: (1) "Distance Education as Communication: The…

  14. BK Del - Lichtkurve und neue Lichtwechselelemente

    NASA Astrophysics Data System (ADS)

    Steinbach, Hans-Mereyntje

    2011-01-01

    For this long time neglected variable new light-change-elements have been derived on basis of CCD-observations. A complete light curve is presented, which confirms the the type as RRab, and its Fourier-coefficients are determined.

  15. Fortpflanzung und Sexualität von Cereus pedunculatus und Actinia equina (Anthozoa, Actiniaria)

    NASA Astrophysics Data System (ADS)

    Schäfer, W.

    1981-12-01

    Sexuality and reproductive behaviour of Cereus pedunculatus (Pennant) and several forms (subspecies) of Actinia equina (L.) from populations collected along the French Atlantic Sea coast and in different habitats along the European Mediterranean coast were studied. At the stage of 96 septae C. pedunculatus and A. e. atlantica II exhibited mature oocytes which developed parthenogenetically into larvae. The latter appeared simultaneously in the gastrocoele. Adolescent A. e. atlantica II developed very few mature oocytes and larvae. Following a sterile period, oocytes and young individuals of different age groups were present almost throughout the whole year in adult anemones. A. e. mediterranea I was dioecious and oviparous in any habitat observed. Samples of the larviparous A. e. mediterranea II (collected near Banyuls, France) exhibited male gonads exclusively and contained larvae. Spontaneous longitudinal fission was occasionally observed in adult A. e. mediterranea I and adolescent A. e. atlantica II.

  16. Die Cnidogenese der Octocorallia (Anthozoa, Cnidaria): II. Reifung, Wanderung und Zerfall von Cnidoblast und Nesselkapsel

    NASA Astrophysics Data System (ADS)

    Schmidt, H.; Moraw, B.

    1982-03-01

    Migration of cnidoblasts has never been observed in Anthozoa. In contrast to hydrozoans, anthozoans are repeatedly reported to develop nematocysts locally without migration in the entoderm as well as in the ectoderm. The majority of the nematocysts studied in different Octocorallia species (Alcyonaria: Alcyonarium digitatum, Parerythropodium coralloides; Gorgonaria: Pseudopterogorgia aerosa; Pennatularia: Veretillum cynomorium) originate from the ectoderm of the scapus, where, however, no mature nematocysts occur. Cnidoblasts containing immature nematocysts accumulate in the distal scapus, from where they migrate singly like amoebae into the pinnulae of the tentacles. The nematocysts mature during migration, during which the capsular matrix becomes completely electron-translucent. Only in the oral disc, where few nematocysts occur, do they mature locally without migration. In the Octocorallia, nematocyst development and maturation takes places only in the ectoderm. Development of nematocysts has never been observed in the entoderm, nor in the pharynx; this demonstrates its entodermal origin. The entoderm contains only degenerated or phagocytized nematocysts. Contrary to hydrozoans, the mature anthozoan cnidocyte is rounded and has no processes to the mesogloea. Instead of a cnidocil it has a ciliary cone consisting of a normal flagellum, stereocilia and macrovilli. The cnidocyte is characterised by abundant electron-translucent cytoplasm and nematocyst-anchoring structures made up of cross-striated, collagen-like fibrillae and a fibrous basal ring. The position of the cross-striated fibrillae is distally similar to that of the supportive rods in hydrozoan cnidoblasts. The present study clearly demonstrates that structure and, possibly, function of an octocorallian cnidocyte is much simpler than that of a hydrozoan cnidocyte. On the other hand, cnidoblast migration, occurring in Hydrozoa as well in Octocorallia, turned out to be a much older phylogenetic character than was formerly believed.

  17. Hydrogeochemie und geogene Fluorid- und Borproblematik des Emschermergels im Münsterland

    NASA Astrophysics Data System (ADS)

    Wisotzky, Frank; Droste, Björn; Banning, Andre

    2017-01-01

    The hydrogeochemistry of the Cretaceous Emscher Fm. in northwest Germany was investigated, including analysis of 160 rock samples for carbon and sulfur content. Beneath a weathered zone, unweathered rocks containing pyrite were found. Groundwater data from the Emscher Fm. (580 analyses of house wells and additional literature data) were collected and evaluated. Some groundwater contains high fluoride and boron concentrations of up to 10 mg/l. Regionally, up to 30% of house wells show fluoride concentrations above 1.5 mg/l, and up to 50% above 1 mg/l boron. The spatial distribution depends on the presence of Quaternary cover sediments. Groundwater with high fluoride concentrations displays low Ca2+, and vice versa, indicating equilibrium with the mineral fluorite (CaF2). Concentrations above drinking water guidelines almost exclusively occur in ion exchange waters of the Na-HCO3 -(Cl) type with pH > 7.5. The main mobilization mechanism of both contaminants appears to be pH-triggered desorption from mineral surfaces.

  18. Diskrepanzen und Kongruenzen: Das Dilemma des afrikanischen Kindes zwischen Familie und Schule

    NASA Astrophysics Data System (ADS)

    Bauer, Annemarie

    1986-03-01

    This article expounds the theory that the failure of school is due to the incompatibility of the educational goals of school and traditional upbringing in Africa. The thesis is put forward by adherents of the psychoanalytical model of child development and seeks to emphasize the discrepancies between the childhood where children are not frustrated and where their needs are cared for and the school education which represses the drives and its socialization of children. Finding a number of anthropological studies are discussed and reinterpretations of the ethno-psychoanalytical materials attempted. Neither the evaluation of childhood in Africa nor the theory that with school come wholly new expectations of behaviour (e.g., a performance requirement) can no longer be maintained. In conclusion, other explanations for the difficulties encountered by school in Africa are offered.

  19. BOOK REVIEW: Einsteins Kosmos. Untersuchungen zur Geschichte der Kosmologie Relativitatstheorie und zu Einsteins Wirken und Nachwirken

    NASA Astrophysics Data System (ADS)

    Sterken, C.; Duerbeck, H. W.; Dick, W. R.

    2006-12-01

    This book collects about 15 papers (most of them by one single author) on Einstein and the history of general relativity (GR) and the foundations of relativistic cosmology. The matter not only deals with Einstein and his times, but also with pre-GR ideas, and with the interplay of Einstein and his colleagues (opposing as well as supporting personalities). As the title indicates, all papers are written in German, but they include comprehensive Abstracts both in German and English. The book is illustrated with quite a number classical - but also some far more original though not less beautiful - photographs and facsimiles of documents. The book is edited very well, though the style of references is not quite homogeneous. There is no Index. K. Hentschel covers Einstein's argumentation for the existence of graviational redshift, and the initial search for empirical support. The error analysis of observational evidence supporting relativistic light deflection is discussed in a paper by P. Brosche. In particular, H. Duerbeck and P. Flin - in their description of the life and work of Silberstein, who was quite sceptic on the significance of the observational verifications a la Eddington - include the transcription of two most revealing letters by Silberstein to Sommerfeld (1919) and to Einstein (1934). In the first letter, Silberstein clearly shows his scientific maturity and integrity by scrutinising the observational evidence supporting light deflection, presented at a joint meeting of the Royal Society and the Royal Astronomical Society. The second letter, which is more a personal letter, includes lots of political references and connotations. Some of Einstein's political views are also revealed by D.B. Herrmann on the basis of his own correspondence with E.G. Straus, a collaborator of Einstein's. In a consequent paper, S. Grundmann gives remarks on Herrmann's contribution and illustrates Einstein's attitude towards Marx, Engels, Lenin and Stalin. M. Schemmel discusses Schwarzschild's cosmological speculations, and wonders why some people do immediately grasp the meaning and consequence of newly proposed doctrines, whereas the bulk of the contemporaneous scientists respond in a rather low profile. T. Jung reviews Einstein's contribution to cosmology, leading to the Friedmann-Einstein and Einstein-de Sitter universes (with a detailed Appendix on the Friedmann-Lemaitre cosmology), and also presents the cosmological work of Selety, and his correspondence with Einstein. In a subsequent paper, H.-J. Schmidt comments on Einstein's criticism on de Sitter's solution of the Einstein field equations. Controversies with Einstein are elaborated by G. Singer (on Friedmann) and by K. Roessler (on Lemaitre). J. Renn and T. Sauer discuss Mandl's role in the publication history of Einstein's papers, notably Einstein's short paper on gravitational lensing. Finally, the book concludes with a contribution by D.B. Herrmann about the relationship between Einstein and Archenhold Observatory (where Einstein gave his first Berlin popular lecture in 1915), the transcription of H.-J. Treder's 1979 public address at the Einstein memorial plaque, and an inventory list of about 50 Einstein memorabilia - monuments, busts, plaques - compiled by W.R. Dick. This book is based on ideas approached in a historical context from the individual perspective of the authors. It is a real treasure trove of information and basic references on the history of GR, and it also covers quite some grounds with mathematical equations.

  20. Lenin und Kuhn zum Verhältnis von Krise und Revolution

    NASA Astrophysics Data System (ADS)

    Engler, Fynn Ole

    In seinem Exil im schweizerischen Gebirgsdörfchen Sörenberg verfasste Lenin, der intellektuelle Kopf der Sozialdemokratischen Arbeiterpartei Russlands (Bolschewiki), im Mai/Juni 1915 seine wohl umfangreichste theoretische Abhandlung über die Ursachen des Zusammenbruchs der Zweiten Internationale. Den konkreten Anlass dafür lieferten die Ansichten führender sozialdemokratischer Arbeiterparteien seit dem Ausbruch des Ersten Weltkriegs im August 1914.

  1. Hydrogeochemie und geogene Fluorid- und Borproblematik des Emschermergels im Münsterland

    NASA Astrophysics Data System (ADS)

    Wisotzky, Frank; Droste, Björn; Banning, Andre

    2017-03-01

    The hydrogeochemistry of the Cretaceous Emscher Fm. in northwest Germany was investigated, including analysis of 160 rock samples for carbon and sulfur content. Beneath a weathered zone, unweathered rocks containing pyrite were found. Groundwater data from the Emscher Fm. (580 analyses of house wells and additional literature data) were collected and evaluated. Some groundwater contains high fluoride and boron concentrations of up to 10 mg/l. Regionally, up to 30% of house wells show fluoride concentrations above 1.5 mg/l, and up to 50% above 1 mg/l boron. The spatial distribution depends on the presence of Quaternary cover sediments. Groundwater with high fluoride concentrations displays low Ca2+, and vice versa, indicating equilibrium with the mineral fluorite (CaF2). Concentrations above drinking water guidelines almost exclusively occur in ion exchange waters of the Na-HCO3 -(Cl) type with pH > 7.5. The main mobilization mechanism of both contaminants appears to be pH-triggered desorption from mineral surfaces.

  2. Elektronenmikroskopische Untersuchungen an Anaitides mucosa (Annelida, Polychaeta). Cuticula und Cilien, Schleimzellen und Schleimextrusion

    NASA Astrophysics Data System (ADS)

    Hausmann, K.

    1982-03-01

    Two components, a basal cuticle and an epicuticle, make up the cuticle of A. mucosa. The basal cuticle consists of collagen fibrils, which are arranged in about 20 layers. The orientation of the fibrils changes rectangularly from one layer to the next. Fine filaments interweave the basal cuticle. The epicuticle, which is covered by a layer of electron dense material, is composed of irregularly arranged thin filaments. Branched microvilli of the epidermal cells penetrate the cuticle. Bacteria are found in the basal cuticle. Dorsally each segment has a band of densely packed smooth cilia. Laterally and partly ventrally aggregates of cilia are observed. These cilia exhibit apically artificial swellings. At least six different mucous cells are observed in the epidermis, morphologically distinguishable by the structure of the secretion products. Mucus is secreted via exocytosis through cuticular pores. During this process the mucus might expand. The secreted mucus consists of filamentous subunits.

  3. Urbanisierung und Ökologische Stadtentwicklung. Zur Integration urbaner Biodiversität und Ökosystemleistungen in Deutschland und China

    NASA Astrophysics Data System (ADS)

    Kümper-Schlake, Lennart

    2016-06-01

    Urbanisation processes increase land-use conflicts and ecosystem destruction globally. Especially in China, a country with an outstanding urbanization rate, city governments are challenged by environmental and health problems. Urban green spaces - subsequently defined as urban biodiversity and ecosystem services - can minimize numerous environmental risks and at the same time contribute to the citizens' well-being and quality of life. In this highly relevant field of nature conservation, geographical perspectives are required - in science, politics, policy, planning and practice.

  4. Die Titicaca-See-Region auf dem Altiplano von Peru und Bolivien und die Folgen eingeführter Fische für Wildarten und ihren Lebensraum

    NASA Astrophysics Data System (ADS)

    Villwock, Wolfgang

    1993-01-01

    In the course of a long-term case study (since 1960) the interaction between different exotic fish (salmonids, atherinids) on the endemic ichthyofauna (genus Orestias: Cyprinodontidae) introduced to the interandean basin of Lake Titicaca was observed. The contribution deals not only with the actual consequences which endanger endemic species but also the socio-economic effects on the native Indian population, both causing further ecological problems in the region of concern.

  5. Form und Sinn: Sprachwissenschaftliche Betrachtungen (Form and Meaning: Linguistic Observations).

    ERIC Educational Resources Information Center

    Jakobson, Roman

    This collection of 14 papers and articles by Roman Jakobson contains works written and published between 1931 and 1970 which deal either with global aspects of language or with specific grammatical issues. The collection emphasizes Jakobson's concern for finding the links between form and meaning in language. The text is entirely in German with…

  6. Black Hawk Down: Film Zwischen Reflektion und Konstruktion Gesellschaftlicher Wirklichkeit

    NASA Astrophysics Data System (ADS)

    Pötzsch, Holger

    2009-05-01

    BLACK HAWK DOWN: FILM BETWEEN THE REFLECTION AND CONSTRUCTION OF SOCIAL REALITY - In this article, Ridley Scott's film Black Hawk Down (USA 2001) is read in the context of contemporary theories concerning cultural memory (Jan and Aleida Assmann) and media culture (Douglas Kellner). It is argued that film (and representation in general) does not merely reflect a preceding reality; it also actively serves to construct it. It is shown how Scott's film privileges one particular perspective on an actual event and how this point of view is objectified and installed in the memory of Western media culture. What potential implications does an increased blurring of fact and fiction in the representation of war have? What are the consequences for political and pedagogical practice? What role can cultural studies play in these processes?

  7. BAV-Calina-Remote-Teleskop - neues Teleskop und neue Montierung

    NASA Astrophysics Data System (ADS)

    Pagel, Lienhard

    2013-02-01

    BAV has installed a remote telescope at the observatory Calina in Carona (South-Switzer- land) in September 2012. In the coming weeks the system will be updated. The new mout Meade LX80 and the 8-inch Boren-Simon-astrograph with an astro camera QHY8L will be the main components.

  8. Blutpräparate und therapeutische Anwendung (Hämotherapie)

    NASA Astrophysics Data System (ADS)

    Burkhart, Jürgen; Leimbach, Rainer; Nagl, Detlev; Weinauer, Franz

    Die Geschichte der Blutübertragung lässt sich bis in das Altertum verfolgen - wenn auch hier das Blut nicht in die Blutgefäße eingebracht, sondern als Trank verabreicht wurde. Im alten Rom stürmten die Zuschauer in die Kampfarena, um das Blut verletzter Gladiatoren zu trinken, in dem Gedanken, deren Stärke würde in sie überfließen. So wurden auch Greise mit dem Blut von Jünglingen behandelt. Der Glaube, mit dem Blut würden Eigenschaften des Spenders übertragen, muss wohl auch bei dem Versuch mitgewirkt haben, Verbrecher durch Übertragung von Schafsblut "lammfromm“ zu machen. Zu Beginn der Mensch-zu-Mensch-Übertragung wurde Blut mittels eines Röhrchens von Blutgefäß zu Blutgefäß transfundiert. Diese im Mittelalter neu erprobte Form basierte auf der Entdeckung des Blutkreislaufes durch William Harvey (1578-1657). Es überwog allerdings noch die Blutübertragung vom Tier auf den Menschen, die nicht selten mit dem Tod beider Beteiligter endete. In der aufklärerischen Phase der französischen Revolution wurde diese Art der Blutübertragung deshalb verboten.

  9. Möglichkeiten und Grenzen der genetischen Manipulation

    NASA Astrophysics Data System (ADS)

    Klingmüller, Walter

    1981-03-01

    Examples for genetic engineering are the transfer of nuclei between cells of higher animals and the introduction of heterologous DNA into bacteria by means of plasmids. The former approach will help to establish new ways in animal breeding, the latter provides bacterial cells that produce proteins of medical importance. The moral justification of related studies in man is still open, but the possible risks of gene technology can be coped with by adhering to proper safety regulations.

  10. Amor und der Abstand zur Sonne. Geschichten aus meinem Kosmos

    NASA Astrophysics Data System (ADS)

    Kippenhahn, Rudolf

    2001-10-01

    R. Kippenhahn hat in vielen Büchern die Astronomie populär gemacht. Ihn interessieren dabei immer auch die kuriosen Aspekte seiner Wissenschaft. Von ihnen erzählt er in den kleinen Geschichten dieses Buches.

  11. Rede und Gesinnung (Speech and Ways of Thinking)

    ERIC Educational Resources Information Center

    Kienzle, Bertram

    1974-01-01

    Analyzes some of the basic ideas in Georg Franklin's book "Versuch einer neuen Lehre von den vornehmsten Gegenstanden der deutschen Sprachlehre; nach den Regeln der Vernunftlehre in sechs Abhandlungen verfasst" (1778) and compares them to those of such modern linguists and philosophers a s Searle, Austin and Wunderlich. Concludes that…

  12. Bestimmung thermischer Eigenschaften der Gesteine des Unteren und Mittleren Buntsandsteins

    NASA Astrophysics Data System (ADS)

    Franz, Claudia; Schulze, Marcellus

    2016-03-01

    For accurate planning of vertical borehole heat exchanger systems, knowledge of thermo-physical ground parameters is critical. This study reports laboratory-measured thermal conductivity and diffusivity values of Mesozoic sandstones (Lower and Middle Buntsandstein) from four wells. The measurements were made on drill core using an optical scanning method. The mean thermal conductivities of the sandstones range between 2.6 ± 0.3 W / (m · K) and 3.1 ± 0.4 W / (m · K) for dry conditions and between 3.6 ± 0.3 W / (m · K) and 4.1 ± 0.6 W / (m · K) after saturation with water. The mean thermal diffusivity values range between (1.6 ± 0.2) · 10- 6 m2 / s for dry and (2.0 ± 0.6) · 10- 6 m2 / s for water-saturated sandstones. Thermal properties are closely related to the petrography and lithostratigraphy of the sandstones. Additionally, three temperature correction methods were applied for the purpose of evaluating the comparative accuracy and the correction schemes with respect to local in-situ conditions. The results show that the temperature corrections proposed by Somerton (Thermal properties on temperature-related behavior of rock/fluid systems, Elsevier, New York, S 257, 1992) and Sass et al. (J Geophys Res, 97:5017-5030, 1992) are most suited for the respective sandstone data set.

  13. Urbane Hydrogeologie - Herausforderungen für Forschung und Praxis

    NASA Astrophysics Data System (ADS)

    Schirmer, M.; Strauch, G.; Reinstorf, F.; Schirmer, K.

    2007-09-01

    Urban areas are a focus of increasing conflict with regard to water use and water protection. Half of the world’s population and about 73 % of Europeans live in cities. Currently, about 82 % of the total population growth of the world occurs in the cities of the developing countries (UN 2004). As a direct and/or indirect consequence of human activity, urban water systems are frequently polluted with organic contaminants. Many of these contaminants are related to human behaviour and activity, such as pharmaceuticals, personal care products (collectively PPCPs) and endocrine-active substances, and are increasingly found in urban water systems. However, the behaviour and the effects of these contaminants in the environment have been widely unknown until now. Consequently, it is important to pay more attention to such substances and to explore new integrated methodologies (including flux calculations as well as chemical and biological investigations) for determining the impact of human activities on urban water systems and on processes within the urban watershed. The overall goal is to assess the risks to humans and the ecosystem, and to support the development of suitable management strategies.

  14. 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

  15. Vielfarben-Klassifikation in CADIS und die Suche nach Quasaren.

    NASA Astrophysics Data System (ADS)

    Wolf, C.

    1999-01-01

    The Calar Alto Deep Imaging Survey (CADIS) is a deep photometric multicolor survey on ten rather empty fields of the sky well suited for extragalactic studies. As part of this work, a photometric classification technique was developed which sorts all objects into the classes "star", "galaxy", "quasar" and "unclassified". This classification is based on published spectral libraries. It also performs a redshift estimation for galaxies and quasars. Instead of a template fitting procedure, a mathematically almost equivalent procedure is used in this work that is essentially deduced from classification theory and can be implemented much more efficiently than a template fitting algorithm. A general introduction into the subject of classification is given in this report and its application to CADIS is detailed. The performance of the classification was checked by taking slit spectra of about 100 objects in the CADIS 9 h- and 16 h-fields using MOSCA at Calar Alto. Another 150 identifications in the 3 h-field were taken from the Canada-France Redshift Survey, increasing the number of objects with both photometric and spectroscopic classification to about 250. Among these, only five objects were misclassified (=2%) showing the classification to be excellent. After sorting the CADIS objects into the various classes, the sample of quasar candidates was analysed in more detail.

  16. Gluck zwischen Okonomie und Padagogik (Happiness between Economics and Pedagogics).

    ERIC Educational Resources Information Center

    Keller, Sarah; Mangold, Max

    2002-01-01

    Focuses on the concept of happiness as neither formed independent from economic considerations, nor is it foreign to them. Argues that in the history of pedagogy and economics, happiness constitutes an important and at times a problematic quality. (CAJ)

  17. UNDS Phase II Batch One: National Consistency Determination

    EPA Pesticide Factsheets

    Under the Coastal Zone Management Act, federal actions that are national or regional in scope must issue an accompanying National Consistency Determination, to ensure that the action does not overly conflict with state/territory-level coastal programs.

  18. Grundwasser in Nürnberg: Wichtige Einheiten und deren Nutzbarkeit

    NASA Astrophysics Data System (ADS)

    Baier, Alfons; van Geldern, Robert; Löhr, Gisela; Subert, Hannah L.; Barth, Johannes A. C.

    2016-09-01

    The use and protection of urban - area aquifers such as the groundwater resources below the city of Nuremberg is becoming increasingly important. Hence, we present a stratigraphic and hydrogeologic overview of the "Nuremberg Syncline". The Nuremberg Syncline regional aquifer system can be divided into seven units. Geochemical and stable isotope investigations have shown that strict hydraulic separations between aquifers and aquitards do not always exist. Connections may be enhanced, for example, via tectonic discontinuities that enable the rise of CO2-rich groundwaters from deeper units. This is confirmed by frequent occurrences of artesian well conditions. Important subsurface structures in the near-surface aquifers include four palaeo-valleys that cut deep into the stratigraphic units of Keuper sandstones (Keuper Group; Middle and Late Triassic). These remarkable palaeo-valleys have been investigated with more than 2400 boreholes. The gravel and sand deposits of these aquifers offer, for instance, ideal possibilities for both heating and cooling of buildings by geothermal heat pumps.

  19. Wortbildung und Fremdsprachenunterricht (Word Formation and Foreign Language Teaching)

    ERIC Educational Resources Information Center

    Schier, Juergen

    1977-01-01

    Word formation is seen as receiving too little attention in foreign language teaching; its study increases auditory and reading understanding. Practical suggestions are given for collecting and arranging material, and for analyzing the structure of words. (Text is in German.) (IFS/WGA)

  20. Kalkbohrende Mikrothalli bei Helminthocladia und Scinaia (Nemaliales, Rhodophyta)

    NASA Astrophysics Data System (ADS)

    Kornmann, P.; Sahling, P.-H.

    1980-03-01

    Shell-boring microthalli in Helminthocladia and Scinaia (Nemaliales, Rhodophyta). Spores shed from pink mussel shells were shown to develop into branched monosiphonous thalli, their filaments penetrating into shell fragments. Isolates from four single germlings were cultivated. Two of these produced gametophytes of Helminthocladia and Scinaia; the others have so far only reproduced by tetraspores or monospores. Evidently the microthalli of some genera of the Nemaliales — which are, with the exception of Nemalion multifidum, known only from cultures — are shell-inhabiting and have therefore not been found in nature. The adult algae occur mainly on shells and CaCO3 substrates. Until the beginning of the century, Helminthocladia and Scinaia frequently occurred at Helgoland, but they have not been found there for more than 50 years. Their microthalli, however, are still present as shell-boring algae. This study is intended to stimulate similar ones in other genera of the Nemaliales so as to obtain a broader basis for discussion of systematic and phylogenetic relationships.

  1. Physik gestern und heute: Visualisierung mit der Schlierenmethode

    NASA Astrophysics Data System (ADS)

    Heering, Peter

    2006-07-01

    Der Name des österreichischen Forschers Ernst Mach ist heute noch mit der Schallgeschwindigkeit verbunden. Diese Auszeichnung resultiert aus Machs Untersuchungen, wie sich Projektile mit Überschallgeschwindigkeit durch die Luft bewegen. Gerade in jüngster Zeit hat die Anwendung derartiger Methoden durch technische Modifikationen wieder einen Aufschwung erfahren.

  2. Microwave Radiometer - UND Radiometrics MWR, John Day - Reviewed Data

    DOE Data Explorer

    Leo, Laura

    2017-03-31

    The present dataset contains the post-reprocessed level1 and level2 data files from November 2015 to May 2016. The original raw dataset's (mwr.z02.00) purpose was to monitor real-time profiles of temperature (K), water vapor (gm-3), relative humidity (%), and liquid water (gm-3) up to 10 km.

  3. Uniform National Discharge Standards (UNDS): Frequently Asked Questions

    EPA Pesticide Factsheets

    Provides the answers to common questions about the Uniform National Discharge Standards, including what they are, how discharges were evaluated, what vessels are covered by the regulations and how states have been involved.

  4. "Bildungsstandards"--Erwartungen und Bedingungen, Grenzen, und Chancen ("Educational Standards"--Expectations and Conditions, Limits, and Opportunities).

    ERIC Educational Resources Information Center

    Herrmann, Ulrich

    2003-01-01

    Discusses educational standards, core curricula, competence models, school autonomy, school evaluation, and from input-to output-control as important catchwords in the present education and school policy debate. Points out that the Program for International Student Assessment (PISA) has triggered a new educational debate in Germany that calls for…

  5. Lichtkurve und Periode des RR-Lyrae-Sterns TV Trianguli und GSC 02297-00060, ein neuer Veraenderlicher im Feld

    NASA Astrophysics Data System (ADS)

    Groebel, Rainer

    2014-03-01

    Based on data from the SWASP database and on recent observations 21 maxima and 12 minima timings of the little studied star TV Tri could be derived. It is shown that since the discovery the period remains essentially constant. The light curve shows only slight variations with a hump in the ascending branch. An improved ephemeris HJD (max.) = 2447385.354(5) + 0.7057324(5) x E is given. It turned out that the nearby suspected variable NSV 15327 (GSC 2.3 NBXY006220, 1:33:24.96 +32:27:39.10) remained constant in the observation period. It could be shown that the star GSC 02297-00060 (1:32:54.08 +32:29:34.85) also present in the field, is a short period eclipsing variable with shallow eclipses of 0.1 mag amplitude with the ephemeris HJD (min.) = 2456220.5180(16) + 0.2556919(14) x E. Rainer Groebel is a member of the BAV.

  6. Identifikation und Regionalisierung von Nitratabbauprozessen in einem Grundwasserleiter - Möglichkeiten und Nutzen für die Wassergewinnung

    NASA Astrophysics Data System (ADS)

    Jesußek, Anna; Hansen, Carsten; Wilde, Siegfried

    2016-11-01

    Denitrification with pyrite or organic carbon compounds in aquifers can lead to the release of ferrous iron, sulfate and bicarbonate into the groundwater. For the water catchment, Ortheide (Emsdetten, Germany), nitrate reduction with pyrite also causes an increased well clogging with iron hydroxides in some of the wells. With the help of hydrogeochemical modelling (PhreeqC), the main processes in the aquifer of the catchment area were identified and quantified. The presence or absence of pyrite in the aquifer sediments was determined based on groundwater compositions. This allowed the regionalization of autolithotrophic denitrification in the aquifer and the distinction of so called "origin zones" of nitrate, ferrous iron and bicarbonate. Based on these zones, the comparative sensitivity of agricultural areas towards nitrate concentrations in the raw water and the clogging tendency of the wells could be estimated.

  7. Intentionen und Legitimationsstrategien staatsburgerlicher Erziehung und Politischer Bildung (Intentions and Legitimization Strategies of Civic and of Political Education).

    ERIC Educational Resources Information Center

    Schluss, Henning

    2001-01-01

    Examines the intentions of political education and the legitimization strategies of civic education, as illustrated by social studies, that constitutes the central subject of political education in Thuringia (Germany). Focuses on issues such as redefining the concept of transformation and the concept of civic and political education. (CMK)

  8. Possibility of production of neutron-rich Zn and Ge isotopes in multinucleon transfer reactions at low energies

    SciTech Connect

    Adamian, G. G.; Antonenko, N. V.; Sargsyan, V. V.; Scheid, W.

    2010-02-15

    The production cross sections of new neutron-rich {sup 84,86}Zn and {sup 90,92}Ge isotopes beyond N=50 are estimated for the first time in the multinucleon transfer reactions {sup 48}Ca + {sup 238}U and {sup 48}Ca + {sup 244}Pu. The production of new isotopes in reactions with a {sup 48}Ca beam is discussed for future experiments.

  9. PS187 - a good statistics study of antiproton interactions with nuclei: preliminary results

    SciTech Connect

    Sunier, J.W.; Bol, K.D.; Clover, M.R.; DeVries, R.M.; DiGiacomo, N.J.; Kapustinsky, J.S.; McGaughey, P.L.; Smith, G.R.; Sondheim, W.E.; Buenard, M.

    1984-01-01

    The goals of LEAR experiment PS187 are reviewed. The current status of the experiment is discussed, and final data on a search for anti p-nucleus bound states formed by the reactions /sup 28/Si(anti p,p) and /sup 28/Si(anti p,d) are presented.

  10. Fortbildungsbedarf und Fortbildungsangebote im Bereich: Bibliothekswesen, Information und Dokumentation in der Bundesrepublik Deutschland und Berlin (West) (The Need for and Availability of Further Education in the Librarianship/Information and Documentation Field in West Germany and West Berlin).

    ERIC Educational Resources Information Center

    Simon, Hans-Reiner

    This investigation into the availability of and demand for further educational measures in library and information science indicates that obvious discrepancies exist, with demand exceeding availability in the following areas: EDP (electronic data processing) use; criteria for selection for EDP use; online use, including retrieval and database…

  11. Wortbildung und Fremdsprachenunterricht. Ein Beitrag zur Vermittlung zwischen Theorie und Praxis [Word Formation and Foreign Language Teaching. A Contribution to Bridging between Theory and Practice (Part 2)].

    ERIC Educational Resources Information Center

    Storch, Guenther

    1979-01-01

    Only regular word-building patterns are considered. Patterns are chosen for their communicative value, degree of difficulty, and applicability. Examples of word-building exercises are given, taken from actual texts. Work in word formation is recommended even for the beginners' level. (IFS/WGA)

  12. Wortbildung und Fremdsprachenunterricht. Ein Beitrag zur Vermittlung zwischen Theorie und Praxis [Word Formation and Foreign Language Teaching. A Contribution to Bridging between Theory and Practice (Part 1)].

    ERIC Educational Resources Information Center

    Storch, Guenther

    1979-01-01

    Sees word formation as an economical, important means of building vocabulary. Gives examples showing several different word-building patterns. Sees as a reasonable teaching goal the gaining of competence only in "receptive" word formation, i.e., recognition. The student can learn to build new words only from simple, frequently recurring…

  13. Entwicklungen und Auswirkungen der Schulprofilierung an allgemeinbildenden Schulen in ausgewählten europäischen Ländern und Implementationsperspektiven für Deutschland

    NASA Astrophysics Data System (ADS)

    Nonte, Sonja

    2013-07-01

    Developments and consequences of school profiling in general-education schools in selected European countries and perspectives for implementation in Germany - The development of a school programme, e.g. by way of forming a profile in the field of music or sports, is part of everyday school life in many European state and private schools today and even statutory in some countries and states. This paper focuses on the background and the significance of this development in school politics but also on the potential and the challenges which come with the profile formation of schools on an individual as well as systemic basis. Furthermore, the author introduces and discusses examples for the profile formation of schools and classes by looking at concrete projects. After that, recommendations are given for school programme work in individual schools. The focus is especially on German-speaking countries such as Germany, Austria and Switzerland.

  14. Molekülinterne Dipolorientierung und dielektrische Absorption in verdünnter Lösung bei Mikro-und Submillimeterwellen. V.Acetyl-Verbindungen

    NASA Astrophysics Data System (ADS)

    Klages, Gerhard

    1989-09-01

    The dielectric loss of sixteen molecules, eleven with the acetyle group in aromatic bonds and five in aliphatic bonds, has been measured in very dilute solutions of cyclohexene at 20 °C. Five of these molecules are investigated in decalene solutions, too. The measurements have been made at wavenumbers in the range 0.08 to 140 cm -1 above 8 cm -1 making use of a pumped molecular laser. They are supplemented by the data of a Fourier transform spectrometer up to 300 cm -1. All microwave spectra of loss factor ɛ″ are analysed in terms of three absorption areas using the two variable Mori formalism. On the other hand, Lorentz curves are fitted to the FIR absorption spectra of α(v¯). The fast relaxation process of the aliphatic compounds is suggested to be due to intramolecular reorientation of the acetyle group itself, since in acetyle cyclohexene the remaining part of the molecule is rigid. To the contrary, the acetyle group is not able to reorientate swiftly, if bounded to aromatic rings. Presumably, it is fixed by mesomeric interaction with the dipole in the plain of the ring. However, 2-methyl acetophenone and 1-acetyle naphthone show some quick dipole reorientation, which coincides with a steric hindrance of the group in entering the plain of the ring.

  15. Soziale Welten von Schulern und Schulerinnen. Uber Populare, Padagogische und Szientifische Ethnographien (Social World of Male and Female Students -- On Popular, Pedagogical and Scientific Ethnographies).

    ERIC Educational Resources Information Center

    Zinnecker, Jurgen

    2000-01-01

    Provides a survey on projects, authors, topics, and methods in recent ethnographic studies carried out in Germany and elsewhere. Describes embedding scientific student ethnography into a field of discourse. Concludes with a prognosis relating to the future perspectives of this segment of educational research. (CMK)

  16. Zum Problem der Korrektur und Bewertung des commentaire de texte als Arbeits - und Pruefungsform (On the Problem of Correcting and Grading Text Commentary in Graduation Exams in French)

    ERIC Educational Resources Information Center

    Hornung, Walter

    1976-01-01

    Discusses two conflicting concepts of correcting and grading high school graduation examinations in French: "mathematical" grading of complex exercises versus objective grading of reduced segments. Recommends higher valuation on goal-orientation as against extreme objectivity. Students' performance must be evaluated individually. Various concrete…

  17. Sozialindex und gewichtenregeling . Berücksichtigung von sozialräumlichen Rahmenbedingungen bei der Mittelvergabe an Schulen am Beispiel Nordrhein-Westfalens und den Niederlanden

    NASA Astrophysics Data System (ADS)

    Terpoorten, Tobias

    2016-12-01

    In Germany and the Netherlands spatial information about the social structure of the inhabitants is used for the coordination of financial and human resources in the local school-system. The aim is to reduce educational inequalities by taking the social context of the schools into account. The article explains two approaches. In North Rhine-Westphalia (Germany) a so called Sozialindex is used to distribute additional teachers to municipalities with difficult social surroundings. The Dutch government uses an instrument to give each pupil a weight (gewichtenregeling) depending on the specific educational background. Combined with an evaluation of the school location an additional budget, if necessary, will be payed.

  18. Selbstgesteuertes Lernen und Modernisierungsimperative in der Erwachsenen- und Weiterbildung (Self-directed Learning and Modernization Imperatives in Adult and in Further Education).

    ERIC Educational Resources Information Center

    Forneck, Hermann J.

    2002-01-01

    Supports the thesis that constructivism and self controlled learning in adult education should be considered reactions to imperatives of modernization. Recognizes that concepts of self-directed learning are accompanied by a change in the forms of organization as well as the logic and structure of action in adult education. (CAJ)

  19. Betriebliche Weiterbildung - Historische Kontinuitat und Durchsetzung in Theorie und Praxis (Within-Company Further Education - Historical Continuities and Success in Theory and Practice).

    ERIC Educational Resources Information Center

    Buchter, Karin

    2002-01-01

    Explores the theoretical foundations of the effort to integrate education into industrial companies during the twentieth century. Analyzes the historical building blocks of vocational education through both theory and practice. Discusses the company-internal further education pedagogy of the 1980s. (CAJ)

  20. Arthur Beer and his relations to Einstein and to the Warburg library (German Title: Arthur Beer und seine Beziehungen zu Einstein und zur Warburg-Bibliothek)

    NASA Astrophysics Data System (ADS)

    Duerbeck, Hilmar W.; Beer, Peter

    We give an account of the scientific life of Arthur Beer (1900-1980). Born in Reichenberg, Bohemia, he studied in Leipzig, Vienna and Berlin. After obtaining his Ph.D., he worked with the Seewarte (maritime observatory) and with the Warburg Library, both in Hamburg. Because of his relations with Finlay Freundlich, Einstein and Fritz Saxl, he succeeded in emigrating to England in 1934, where he obtained a temporary position at Cambridge Observatory, and carried out astrophysical research under F.J.M. Stratton. After shorter stays at the observatories of Mill Hill and Kew, both in the vicinity of London, he obtained, after World War II, the position of Senior Assistant Observer in Cambridge. Besides his studies in astrophysics and the history of astronomy, he is best known as the founding editor of the series "Vistas in Astronomy".

  1. Aktiver und passiver Wortschatz im Englischunterricht und in Lehrwerken der Hauptschule (Active and Passive Vocabulary in Teaching English and in Textbooks Used in Hauptschulen ["Terminal" Junior High Schools])

    ERIC Educational Resources Information Center

    Kerschgens, Edda

    1975-01-01

    Discusses the extent to which five popular English teaching texts distinguish between active and passive vocabulary in learning English, and pleads (offering concrete suggestions) for more attention to the vocabulary aspect in constructing teaching textbooks for junior high schools. (Text is in German.) (IFS/WGA)

  2. Autonomie, Qualitat von Schulen und staatliche Steuerung: Chancen und Risiken von Schulautonomie (Autonomy, the Quality of Schools, and State Control: Chances and Risks of "School Autonomy").

    ERIC Educational Resources Information Center

    Fischer, Dietlind; Rolff, Hans-Gunther

    1997-01-01

    Sketches major arguments in the discussion on school autonomy and links these with debates on school quality. Argues that although autonomy may entail debureaucratization, it does not require the withdrawal of the state. Shows how concepts of market and competition in pedagogical contexts differ from those in economic contexts. (DSK)

  3. Even-odd effects in Z and N distributions of fragments emitted at intermediate energies

    SciTech Connect

    Lombardo, I.; Lanzalone, G.; Agodi, C.; Amorini, F.; Anzalone, A.; Han, J.; Maiolino, C.; Auditore, L.; Loria, D.; Trifiro, A.; Trimarchi, M.; Berceanu, I.; Cardella, G.; De Filippo, E.; Pagano, A.; Papa, M.; Pirrone, S.; Cavallaro, S.; Porto, F.; Rizzo, F.

    2011-08-15

    Even-odd effects in Z and N distributions of light fragments emitted at forward angles in nuclear collisions {sup 40}Ca + {sup 40}Ca, {sup 40}Ca + {sup 48}Ca, and {sup 48}Ca + {sup 48}Ca at 25 MeV/nucleon and identified in charge and mass with the Chimera multidetector have been analyzed. The amplitude of even-odd staggering effects seems to be related to the neutron to proton ratio N/Z of the entrance channels. A qualitative explanation of this effect, taking into account the deexcitation phase of primary excited fragments, is discussed.

  4. Homogeneity characterization of lattice spacing of silicon single crystals by a self-referenced lattice comparator

    NASA Astrophysics Data System (ADS)

    Fujimoto, H.; Waseda, A.; Zhang, X. W.

    2011-04-01

    The homogeneity of the lattice spacings of silicon single crystals from different origins was characterized. Strain measurements were performed on single crystals from NRLM3, NRLM4 and 28Si-10Pr11 ingots, which are all used to determine the Avogadro constant. NRLM3 and NRLM4 both exhibited clear striations, whereas almost no pattern was obtained for 28Si-10Pr11. The standard deviation of the lattice spacing of the single crystal obtained from 28Si-10Pr11 was 4.7 × 10-9, which enabled the lattice spacing to be determined with a standard uncertainty of 3 × 10-9.

  5. [The treatment needs of migrant children according to child and adolescent psychiatrists from medical clinics and in private practice].

    PubMed

    Siefen, Georg; Kirkcaldy, Bruce; Adam, Hubertus; Schepker, Renate

    2015-03-01

    Fragestellung: Wie reagiert das kinder- und jugendpsychiatrische Versorgungssystem in Deutschland auf die steigende Zahl von Kindern und Jugendlichen mit Migrationshintergrund? Methodik: Mit einem weiterentwickelten Fragebogen für psychiatrische Kliniken wurden leitende Ärzte kinder- und jugendpsychiatrischer Kliniken über die Bundesarbeitsgemeinschaft der Leitenden Klinikärzte für Kinder- und Jugendpsychiatrie, Psychosomatik und Psychotherapie (BAG) nach Bedingungen und Entwicklungsmöglichkeiten der Versorgung von Migrantenkindern und -jugendlichen befragt. Außerdem erhielt eine «random representative» Stichprobe niedergelassener Kinder- und Jugendpsychiater über den Berufsverband für Kinder- und Jugendpsychiatrie, Psychosomatik und Psychotherapie in Deutschland e. V. (BKJPP) einen adaptierten Bogen. Ergebnisse: Mit 100 Kinder- und Jugendpsychiatern in eigener Praxis wurden nur etwa 1/8 der Niedergelassenen aber mit 55 Leitenden Ärzten 1/3 und damit eine repräsentative Stichprobe der Chefärzte kinder- und jugendpsychiatrischer Kliniken und Tageskliniken befragt. Jede dritte Klinik hat migrantenspezifische Angebote. In Klinik und Praxis werden zu selten kompetente Dolmetscher eingesetzt. Behandlungsprobleme bei Migrantenkindern und -jugendlichen ergeben sich aus dem Krankheitsverständnis der Eltern, des Patienten und sprachlichen Verständigungsproblemen. Kulturelle Vielfalt wird als bereichernd wahrgenommen. Migrationshintergrund und Gender der Kinder- und Jugendpsychiater beeinflussen die Migrantenbehandlung. Schlussfolgerungen: Durch konkrete Schritte wie die Finanzierung von Dolmetscherkosten müssen der Prozess der «kulturellen Öffnung» unterstützt und die Versorgung von Migrantenkindern und -jugendlichen weiter verbessert werden.

  6. Zufall und Entdeckung in der Forschung nach der Ursache der infantilen amaurotischen Idiotie

    NASA Astrophysics Data System (ADS)

    Jatzkewitz, Horst

    1981-05-01

    Infantile amaurotic idiocy — the classical type known as “Tay-Sachs disease” — is the consequence of the accumulation of a ganglioside and a closely related derivative in the human brain. The accumulation of both substances is due to a genetically induced deficiency of their common catabolic enzyme system. K. Sandhoff discovered three enzymic variants of the disease, which, taken together, did not reveal any apparent causal relationship between enzymic defect and substrate accumulation. The role of chance and discovery in finding the three variants as well as in the elucidation of their causes is described.

  7. [Ophthalmologic short-term operations in Africa--Namibia und Mali: what makes sense?].

    PubMed

    Künster, A; Schwarz, T

    2012-08-01

    Many people even in the more prosperous countries of Africa have no opportunity to receive the necessary eye operations because of socioeconomical aspects. Personal contacts made it possible for our association called "Kids' and Poors' Eyes International e. V." to take part in an international operation camp in Namibia and enter into a cooperation with the German "Mali-Hilfe" organization. Organized by the Namibian Ministry of Health, three operation camps with international surgeons are held annually in remote places in Namibia. Operation materials, such as intraocular lenses, viscoelastics, suturing and draping materials and operation instruments are brought by the operation teams themselves, the microscopes are supplied by the central eye hospital in the capital city of Windhoek. The operation camps last for 4-5 days plus 2 days for travelling, setting up and dismantling the operation settings. Most patients have in fact become blind by dense cataract and are therefore severely impaired. To treat the mostly mature cataracts, an extracapsular technique with a wide lamellar tunnel cut, use of vision blue, expression of the nucleus and intraocular lens (IOL) implantation has been proven as a routine method and in some cases phacoemulsification is possible. In Mali, one of the poorest countries of the world, we achieved initial promising results with the implementation of an educational system to train resident surgeons. We got in touch with Mali via the help of the German-Mali humanitarian organisation "Malihilfe" and direct contacts to the Mali Minister of the Interior. Our presentation is about the experiences we made in our surgical work in both countries and answers questions about what is expedient and reasonable in high-volume surgical humanitarian aid and in the implementation of a system for self-help.

  8. Die Sokratische Lehrstrategie und Ihre Relevanz FÜR Die Heutige Didaktik

    NASA Astrophysics Data System (ADS)

    Kanakis, Ioannis

    1997-03-01

    Socrates (469-399 B.C.) formulated a unique method of teaching, of which the main characteristic is dialogue. We have no authentic record, but Plato has preserved the "Socratic conversations" in his dialogues. In the first part of this study, the Socratic strategy is examined through a comparative analysis of the early Platonic dialogues with the theories of critical rationalism and the cognitive theories based on motivation for achievement and learning. In the dialogues, Socrates invites his interlocutors to express their opinions, professing himself ignorant of the matter under discussion, but gradually challenges their certainties and moves from the particular and the egocentric to the general concept, using concrete examples. The second part of this study gives a detailed presentation of the elements of the Socratic strategy of teaching and learning: conversation, the exploitation of errors in teaching, aporia (confused doubt), critical reflection and intellectual honesty, and tolerance. These continue to be of relevance today and are timely in the context of shifting values and the need for a critical approach to knowledge.

  9. Bildung, Erziehung und Modernisierung in der Franzosischen Revolution: Ein Soziologischer Deutungsansatz.

    ERIC Educational Resources Information Center

    Harten, Hans Christian

    1992-01-01

    Contends that education was an important instrument of social change during the French Revolution. Argues that education became a way to speed up social modernization and, at the same time, hide the contradictions of modernization. (CFR)

  10. Untersuchungen zur Sorptionsreversibilität von organischen Schadstoffen in Aktivkohle, Holzkohle und Zeolith Y-200

    NASA Astrophysics Data System (ADS)

    ElHaddad, Engy; Ensinger, Wolfgang; Schüth, Christoph

    2013-09-01

    Numerous studies have shown that sorption of organic contaminants in soils is dominated by the natural organic carbon content ( C org) of the soil. However, it is still under discussion whether sorption processes are fully reversible or whether an irreversibly sorbed contaminant fraction remains in the soil. This is especially important when considering soil remediation measures and its targets. In multi-stage sorption-desorption batch experiments with TCE, PCE, ortho-xylene and para-xylene and with the sorbents activated carbon, charcoal and a hydrophobic zeolite Y-200, the reversibility of sorption was studied. It could be shown that the structural features of the sorbents are of ample importance for the occurrence of a desorption-resistant fraction. While sorption was mainly reversible for the micro-porous zeolite Y-200 with a rigid pore network, charcoal and the activated carbon showed significant desorption hysteresis. However, following a subsequent sorption step, this fraction eventually desorbs and is re-mobilized.

  11. Johann Christoph Sturm's universal mathematics and metaphysics (German Title: Universalmathematik und Metaphysik bei Johann Christoph Sturm)

    NASA Astrophysics Data System (ADS)

    Leinsle, Ulrich G.

    In order to understand Sturm's concept of a universal mathematics as a replacement or complement of metaphysics, one first has to examine the evolution of the idea of a mathesis universalis up to Sturm, and his concept of metaphysics. According to the understanding of those times, natural theology belongs to metaphysics. The last section is concerned with Sturm's statements on the existence of God and his assessments for a physico-theology.

  12. Die Kometen der Jahre 1531 bis 1539 und ihre Bedeutung fur die spatere Entwicklung der Kometenforschung

    NASA Astrophysics Data System (ADS)

    Kokott, Wolfgang

    The apparition of P/Halley in 1531 is known mostly for Peter Apian's statement of the antisolar direction of cometary tails and for Edmond Halley's discovery of its periodicity following its 1682 return. However, the 1531 event and the four comets of subsequent years are also remarkable for the first attempts, by several observers, to record and investigate their apparent orbits in a quantitative way with an accuracy making modern treatment feasible. Thus, the decade in question may be regarded as the beginning of modern cometary research. Within a broader historical context, the book outlines the significance of this series of comets w.r.t. the change of theory and observational practice prior to Tycho Brahe. It also documents the secondary sources throughout the following centuries and later attempts at interpreting the material. The possibilities inherent in the re-evaluation of historical observations by modern methods in the light of collateral evidence become transparent by means of the results of some recent orbit determinations.

  13. Das Schwimmen der Talitridae (Crustacea, Amphipoda): Funktionsmorphologie, Phänomenologie und Energetik

    NASA Astrophysics Data System (ADS)

    Vogel, Friedhelm

    1985-09-01

    The Talitridae, well-known for their jumping behaviour, swim with help of the tail-flip. This movement of the abdomen is also known from other amphipods like the Gammaridae which are normally not able to move by jerks outside the water. The suspected homology between the tail-flip when swimming and the jerky movement of the abdomen when jumping gave rise to this investigation, mainly based on high frequency film recordings, on the swimming of Hyale nilssonii, Orchestia cavimana, and Talitrus saltator (family Talitridae) as well as three related species of the families Gammaridae and Corophiidae. Comparative morphometrical and SEM-studies on the habitus of the species and the build of the involved limbs reveal the rather uniform construction of the Gammaridea; functional adaptation to the environment and to the way of living become apparent in minor alterations. The joints of the pleopods and uropods show a clear structural adaptation to the mechanical strain during swimming. The pleopods are moved metachronally in all examined species; angular velocity and rate of beating indicate the efficiency of the swimming movement. In the Talitridae, the metachronal beat of the pleopods is nearly always coupled with the tail-flip while in the Gammaridae and Corophiidae the tail-flip, in addition to the beat of the pleopods, is mostly used for a start from the subsoil or for a change in swimming direction. H. nilssonii, Gammarus locusta, and Corophium volutator, all inhabitants of the tidal zone in the North Sea shallows, turned out to be the “best” swimmers while the (semi-) terrestrially living species, O. cavimana and T. saltator, proved to be rather “poor” swimmers. This clearly indicates the ecological significance of swimming for the different species. Furthermore, the tailflip is found to be of rather subordinate importance. It contributes to a higher velocity if used moderately but is rather obstructive if a large angle is covered while extending and flexing the abdomen. The efficiency of swimming is inversely proportional to the efficiency of jumping in the three talitridean species. Thus, better adaptation to terrestrial life is accompanied by loss of swimming efficiency. Examined under the aspect of locomotional homology, it is concluded that the tail-flip used while swimming is homologous to the jerky movement of the abdomen used for jumping. The comparison of the swimming performance of the examined species with other crustaceans and some fishes illustrates the over-all good results of the Gammaridea.

  14. Michael Mästlin and Galileo Galilei. (German Title: Michael Mästlin und Galileo Galilei)

    NASA Astrophysics Data System (ADS)

    Smolka, Josef

    In the earlier literature it is incorrectly claimed that Mästlin, when travelling through Italy, converted Galilei to copernicanism. We know today that Galilei was first introduced to Copernicus' work through Chr. Wursteisen. In 1610, Martin Horký published a note against Galilei's Sidereal Messenger, which also came into the hands of Kepler who forwarded it to Mästlin. While Kepler was infuriorated, Mästlin concurred with the author, and hoped in vain to win Kepler against Galilei's cause. We analyze this historically peculiar attempt, and in addition, we analyze a letter of Thaddaeus Hagecius to Martin Mylius, which deals with Mästlin's work on the new star of 1572, and which shows the remarkable relation between Hagecius and Mästlin.

  15. Neue Erkenntnisse auf dem Gebiete der Parasitologie und der parasitären Erkrankungen des Menschen

    NASA Astrophysics Data System (ADS)

    Piekarski, G.

    1980-01-01

    The increasing interest in the parasites of man in the Federal Republic of Germany is connected with the unbounded keenness of German people to travel. They favor southern regions with warm climates which are usually infested with parasites. Thus the general practitioner is nowadays confronted in his daily routine with “imported” pathogenic organisms and diseases as yet unknown to him or with which he need not have reckoned in the past. Furthermore, new information now exists on the development of well-known parasites of our regions, which can be pathogenic to man. Fortunately, new reliable drugs have come on the market, rendering some parasitic diseases harmless.

  16. Europäisches Bewusstsein: Zur Definition Eines Vielschichtigen Begriffes und Seiner Bildungstheoretischen Bedeutung

    NASA Astrophysics Data System (ADS)

    Jobst, Solvejg

    2005-11-01

    EUROPEAN CONSCIOUSNESS: TOWARDS DEFINING A COMPLEX CONCEPT AND ITS EDUCATIONAL SIGNIFICANCE - The present study aims at a definition of `European consciousness'. In particular, it draws on Henri Tajfel's theory of social identity as well as Roland Wakenhut's and Jutta Gallenmüller's moral determination of national consciousness. European consciousness is then defined as a sense of belonging which, depending on certain identification structures and social perspectives, can take such distinct forms of moral consciousness as `Eurocentrism', `European patriotism', or `reflective European consciousness'. Making reference to Wolfgang Klafki's notion of general education, it is finally argued that the emancipatory contribution of schooling to greater European integration consists in mediating precisely this last way of thinking.

  17. 77 FR 64437 - Airworthiness Directives; Burkhart GROB Luft-und Raumfahrt GmbH Sailplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-22

    ... available in the AD docket shortly after receipt. FOR FURTHER INFORMATION CONTACT: Jim Rutherford, Aerospace...: (816) 329-4165; fax: (816) 329-4090; email: jim.rutherford@faa.gov . SUPPLEMENTARY INFORMATION...: Jim Rutherford, Aerospace Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas...

  18. 78 FR 1726 - Airworthiness Directives; Burkhart GROB Luft- und Raumfahrt GmbH Sailplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-09

    ... INFORMATION CONTACT: Jim Rutherford, Aerospace Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone: (816) 329-4165; fax: (816) 329-4090; email: jim.rutherford@faa...: Jim Rutherford, Aerospace Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas...

  19. 77 FR 16968 - Airworthiness Directives; Burkhart GROB Luft- und Raumfahrt GmbH Powered Sailplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-23

    ... available in the AD docket shortly after receipt. FOR FURTHER INFORMATION CONTACT: Jim Rutherford, Aerospace...: (816) 329-4165; fax: (816) 329-4090; email: jim.rutherford@faa.gov . SUPPLEMENTARY INFORMATION...: Jim Rutherford, Aerospace Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas...

  20. Verminderte Tiefbrunnenergiebigkeit durch Versandung und Versinterung bei Veränderung der Grundwasserchemie

    NASA Astrophysics Data System (ADS)

    Knuth, Christoph; Wisotzky, Frank; Becke, Norbert

    2017-01-01

    In three deep wells of a water works in the Lower Rhine Valley (Germany) decreasing well yield has been observed. To investigate the reasons for this decline, solids analysis (microscopy, Cinorg measurements, XRD-, SEM-analysis) was completed and hydrogeochemical calculations were carried out. The samples examined from the bottom of the wells indicate both hydromechanical entry of sand from the aquifer into the well, and formation of incrustations in the form of calcite within the well. The water analysis results show that almost all measured ion concentrations have increased over the past 10 years, which indicates a general change of the hydrochemical conditions of the aquifer. Hydrogeochemical models suggest that oversaturation exists regarding the mineral phases iron hydroxide and calcium carbonate, and therefore the formation of incrustations is possible.

  1. NASA Dryden technicians (Dave Dennis, Freddy Green and Jeff Doughty) position a support cylinder und

    NASA Technical Reports Server (NTRS)

    2002-01-01

    NASA Dryden technicians (Dave Dennis, Freddy Green and Jeff Doughty) position a support cylinder under the right wing of the Active Aeroelastic Wing F/A-18 test aircraft prior to ground vibration tests. The cylinder contains an 'air bag' that allows vibrations induced by an electro-mechanical shaker device to propagate through the airframe as they would if the aircraft were flying.

  2. Identifizierung der Nitratabbauprozesse und Prognose des Nitratabbaupotenzials in den Sedimenten des Hessischen Rieds

    NASA Astrophysics Data System (ADS)

    Kludt, Christoph; Weber, Frank-Andreas; Bergmann, Axel; Knöller, Kay; Berthold, Georg; Schüth, Christoph

    2016-09-01

    Microbial denitrification contributes significantly to the mitigation of nitrate contamination in sedimentary aquifers by reducing nitrate coupled to the consumption of organic carbon (heterotrophic) and iron sulphides like pyrite (autotrophic). However, these phases are often only present in trace amounts and can become depleted, so that denitrification will eventually cease. In order to implement measures within the EC-Water Framework Directive, we investigated the denitrification potential and the denitrification processes in the sediments of the Hessian Ried. The reduction potential was quantified and characterized by solid-phase analyses of drill core samples. Depth-oriented investigations of hydrochemistry (i.e. stable isotopes, N2Excess) allowed determining nitrate input, reduction progress and average reduction kinetics upstream of selected wells. Despite low sulphide contents (max. 123 mg-S/kg), autotrophic denitrification was typically the dominant process. The results can be used to delineate risk areas, downstream of which denitrification can be expected to cease in the near future.

  3. Exzellenz und Equity: Neue Bildungstheoretische Perspektiven FÜR ein Altes SPANNUNGSVERHÄLTNIS

    NASA Astrophysics Data System (ADS)

    Stamm, Margrit; Viehhauser, Martin

    2009-07-01

    EXCELLENCE AND EQUITY: APPLYING NEW PERSPECTIVES IN THE THEORY OF EDUCATION TO A TRADITIONALLY TENSE RELATIONSHIP - The majority of international assessments of school performance, as well as the international standards-based education reform focus on optimising the skills of children who perform poorly in school. This article, however, places the focus on the top␣performers ("excellence") and links this with the theory of equal opportunities ("equity"). The article follows two main lines of argument. The argument relating to the theory of education deems the achievement of equal opportunities and equity likely only if and when all children start from an equal position and are then allowed to develop unequally and appropriately, according to their individual talents. The second argument highlights the tense relationship between excellence and equity with regard to school children's varying home backgrounds, and asks how intellectual potential can best be discovered and encouraged. At the same time, the article demonstrates that the concept of accelerated learning, in differentiating between individuals within homogenous groups of learners, opens up a number of interesting perspectives and can ultimately redress the tense relationship between excellence and equity.

  4. Audio-Immersion und Deutsch als Fremdsprache (Audio-Immersion and German as a Foreign Language)

    ERIC Educational Resources Information Center

    Jung, Lothar

    1973-01-01

    Based on a paper by H. Schenk presented at 3. Arbeitstagung der Gesellschaft fur Angewandte Linguistik, Stuttgart, West Germany, 7-9 October, 1971 (Third Workshop of the Society for Applied Linguistics). (DD)

  5. Bruno Braunerde und die Bodentypen - The German-speaking friends of the Scottish soil characters

    NASA Astrophysics Data System (ADS)

    Hofmann, Anett

    2014-05-01

    Cartoon figures of soil profiles with faces, legs, arms and funny names: the Scottish soil characters Rusty (Cambisol), Heather (Podzol), Pete (Histosol) and five others were developed at the James Hutton Institute in Aberdeen for outreach activities. They represent eight soil types that are common in Scotland. Recently they have become movie stars in an animated film, where they speak with a Scottish accent. The Scottish soil characters are a true soil science communication success story and it would be great if they had friends in many places to tell some stories from the underground in the respective native languages. This contribution will introduce the draft for 13 German-speaking soil characters that represent the most common soil types in Austria, Germany and Switzerland. Each name is a play on words with respect to German soil classification terms and serves as a mnemonic for typical characteristics of these soils. The 'hair' shows detailed vegetation and the context with common land use. For non-soil scientists the soil characters can be used as story-tellers, e.g. about their life (soil evolution), home (spatial distribution), job (function), fears (threats) and joys (best-practice land use, restoration). Because the International Year of Soil (2015) is an excellent opportunity for new outreach activities, the aim is to publish the German-speaking soil characters as a collaboration of the Austrian, German and Swiss Soil Science Societies. The soil characters could be used in print or online formats, and even - as can be seen in Aberdeen - as human-sized walking soil profiles.

  6. Zwischen Copernicus und Kepler - M. Michael Maestlinus Mathematicus Goeppingensis 1550-1631.

    NASA Astrophysics Data System (ADS)

    Betsch, Gerhard; Hamel, Jürgen

    This book contains the written versions of talks given at a symposium held in Tübingen between 2000 October 11 - 13, and organized by the faculty of physics of Tübingen University. Michael Mästlin (1550 - 1631) was an esteemed astronomer. He was among the first who described comets as cosmic bodies, and who attempted an orbital determination. Already at an early stage, he adhered to Copernicus' heliocentric system, which he transmitted to Kepler. During 47 years, Mästlin was a professor of mathematical sciences in Tübingen, and played an outstanding role in the scientific life of his university. The contributions deal with various aspects of the life and works of Mästlin: his well-received textbook of astronomy, his role in the rejection of the 1582 calender reform by the protestants, his celestial observations, his relation to Kepler and to Galilei, his position to the progress of science of his time. Other contributions analyze contemporary attempts of the quadrature of the circle, give an overview of Mästlin's surviving published and manuscript works, and provide a vivid decription of the everyday life of a Tübingen professor around 1600. All papers are written in German, and have English abstracts.

  7. Begabung, Leistung Und Geschlecht: Neue Dimensionen Im Lichte Eines Alten Erziehungswissenschaftlichen Diskurses

    NASA Astrophysics Data System (ADS)

    Stamm, Margrit

    2007-07-01

    GIFTEDNESS, ACHIEVEMENT AND GENDER - This article deals with the interrelation of giftedness, achievement and gender. It examines the effect of gender affiliation on the development of talent. The cardinal focus is put on the questions of how gender roles influence the lives of gifted children and adolescents as well as what kinds of coping strategies they use to manage these challenges. Based on the thesis stating that the present assimilation of gender roles displays a new challenge of social pressure girls and boys deal with in different ways, the hitherto accessible research findings are discussed in respect of the current state of knowledge. As a result, the existence of the gender gap can be reaffirmed and linked to distinct danger zones for boys and girls. The way into underachievement can be one strategy to get rid of this social pressure.

  8. Das Sprachlabor und der Audiovisuelle Unterricht (The Language Laboratory and Audiovisual Instruction).

    ERIC Educational Resources Information Center

    Freudenstein, Reinhold, Ed.

    Four articles, written in German, discuss such aspects of the language laboratory as: teaching pronunciation in the laboratory (Heinrich Schrand), the dummy-element in transformational grammar (Helmut Heuer), testing in the language laboratory (Kenneth S. Leigh), and language laboratory work in Finland (Roland Freihoff). Nine book reviews on…

  9. Status- und Steuerelemente fur sprachbezoegene Ubungsprogramme (Status and Control Elements for Language Related Training Program).

    ERIC Educational Resources Information Center

    Mitschian, Haymo

    To use computers as a medium to learn a language, there is need for some GUI-elements indicating and regulating the actual status of training. These elements have to be separated into obligatory ones, useful in almost all CALL-software, and facultative ones, necessary for most "teachware." Due to a general need of reducing the difficulties to get…

  10. Mol-Gastronomie Von Schäumen und Träumen

    NASA Astrophysics Data System (ADS)

    Vilgis, Thomas A.

    2005-01-01

    Traumhafte Souffles, köstliches Schokoladenmus, süße Meringuen, lockere Biskuits, wem läuft bei diesen Kulinarien nicht das Wasser im Munde zusammen. In Abwandlung des Sprichworts erweisen sich solche Schäume tatsächlich als Träume, jedenfalls zu Tisch.

  11. Bemerkungen zu den Pronominaladverbien und zur Pronominalitaet (Notes on Pronominal Adverbs and Pronominalness)

    ERIC Educational Resources Information Center

    Helbig, Gerhard

    1974-01-01

    Calls "pro-words" those which refer to a preceding substantive. They are (1) pronouns, (2) pronominal adverbs - "dadurch,""hiermit,""wofur," etc., and (3) pro-adverbs - "dort,""dann," etc. Both (2) and (3) stand for combinations of preposition plus preceding substantive; (3) does this only semantically, while (2) marks the relation overtly. (Text…

  12. Mehrdeutigkeiten und pragmatische Implikationen der Satzadverbien (Ambiguities and Practical Implications of Sentence Adverbs)

    ERIC Educational Resources Information Center

    Goetze, Lutz

    1976-01-01

    Discusses the semantics and structure of sentence adverbs, with particular reference to negation of the declarative sentence. "Nicht" is found to be not properly reckoned with sentence adverbs. By means of examples, suggestions are given about teaching foreigners the use of German adverbs. (Text is in German.) (IFS/WGA)

  13. Enseignement des langues et theories d'acquisition Sprachunterricht unde Spracherwerbstheorien. (Language Teaching and Acquisition Theories).

    ERIC Educational Resources Information Center

    Schwarz, Alexander, Ed.

    1996-01-01

    This collection of articles on language teaching and language acquisition theories includes: "Enseignement des langues et theories de l'acquisition. Introduction au colloque" ("Language Teaching and Theories of Acquisition. Introduction to the Colloquium") (Rene Richterich); "Apprendre une langue dans l'interaction verbale" ("Language Learning in…

  14. Statusanalyse von Meerwasserintrusionen und Grundwasserhaushaltsmodellierung des oberen Küstenaquifers in Agadir, Marokko

    NASA Astrophysics Data System (ADS)

    Görlich, Isa; Weigand, Susanne; Beuel, Sonja; Bouchaou, Lhoussaine; Reichert, Barbara

    2015-03-01

    In Agadir, a coastal town situated in the semi-arid south-western part of Morocco, irrigated agriculture and tourism are the primary economic activities. Both sectors require high volumes of fresh water. Over the last few decades, this constantly increasing demand has resulted in a significant drawdown of the water table, accompanied by seawater intrusion leading to a decrease in water quality. A groundwater storage model has verified the extensive drawdown. Positive terms in the flow balance equation are represented by groundwater recharge from bankfiltration, and by irrigation return flow. The negative terms are dominated by groundwater removal for irrigation. A sensitivity analysis reveals parameters which require further investigation. A spatially and temporally variable seawater intrusion front was identified using specific ion ratios, chloride concentrations and groundwater salinity. The intrusion front extends roughly from the northwest to the southeast, following the coast. Compared to 2005, the intrusion front had advanced further inland by 2010. In 2011 and 2012, the effects of seawater intrusion have tended to diminish.

  15. Johann Leonhard Rost, "novelist" and astronomer; (German Title: Johann Leonhard Rost, "Romanist" und Astronom)

    NASA Astrophysics Data System (ADS)

    Gaab, Hans; Simons, Olaf

    Johann Leonhard Rost (1688-1727) of Nuremberg studied at Altdorf, Leipzig and Jena. During this time, he earned his living by writing gallant novels. In 1715, he returned to Nuremberg, where he pursued his juvenile inclination towards astronomy and became a serious astronomical observer. His introductions to astronomy, written around this time, contributed a lot to popularize astronomy. This contribution attempts to do justice to both the novelist and the astronomer Rost.

  16. Untersuchung der Mira-Sterne RT Boo, TV Peg und VX Aur

    NASA Astrophysics Data System (ADS)

    Raetz, Kerstin; Berthold, Thomas

    2015-02-01

    The light-change of the Mira stars RT Boo, TV Peg and VX Aur was analyzed on three ways for a long time. In the first period I estimated the brightness of the variables on sky monitoring photo plates (red spectral range) from Sonneberg Observatory with Argelander¥s Method, in the last years I measured scanned photo plates with a photometry program and in addition I used visual observations from A.A.V.S.O. for the analysis. The behavior of the periods of the tree stars from 1965 to 2013 is described here.

  17. Christoph Rothmann and Copernicanism. (German Title: Christoph Rothmann und der Copernicanismus)

    NASA Astrophysics Data System (ADS)

    Granada, Miguel A.

    Christoph Rothmann belonged to the first convinced adherents of heliocentric cosmology. The contribution discusses Rothmann's relevant remarks, which are found in his paper of 1586 «Scriptum de cometa», dealing with the comet of the previous year. Rothmann also vehemently defended his concepts in a letter to Tycho Brahe dating from September, 1588, in which he rejected both the old geocentric and Brahe's geoheliocentric system.

  18. Sicheres Wissen und Koennen im Franzoesischunterricht (Secure Knowledge and Skill in the Teaching of French)

    ERIC Educational Resources Information Center

    Greiner, Ingrid

    1974-01-01

    Describes work with "topic sheets," acquiring an understanding of them, their use in teaching and the concrete help of topic sheets in the pupil's personal activity, taking as an example the theme unit "Ma famille et moi." (Text is in German.) (IFS/WGA)

  19. SURFACTANT-ENHANCED EXTRACTION TECHNOLOGY EVALUATION VERSUCHSEININCHTUNG ZUR GRUNDWASSER-UND ALTLASTENSANIERUNG (VEGAS) FACILITY, STUTTGART, GERMANY

    EPA Science Inventory

    This innovative technology evaluation report (ITER) summarized the results of an evaluation of a surfactant-enhanced extraction technology. This evaluation was conducted under a bilateral agreement between the United States (U.S.) Environmental Protection Agency (EPA) Superfund ...

  20. "Fortschritt Und Verantwortung!" Education as a Rallying Cry in Luxembourg's General Elections of 1974

    ERIC Educational Resources Information Center

    Gardin, Matias

    2016-01-01

    Education became a rallying cry in Luxembourg's general elections of 1974. For the first time in the country's post-war history, the Socialists and Democrats entered the government, with new plans for education. The unbroken rule of almost 30 years by the Christian Democrats was over. New "global" educational concepts were employed to…

  1. Kepler, Galilei, the telescope and the consequences. (German Title: Kepler, Galilei, das Fernrohr und die Folgen)

    NASA Astrophysics Data System (ADS)

    Gaulke, Karsten; Hamel, Jürgen

    The papers of this volume are dedicated to Johannes Kepler, the astronomy of his time, and the consequences of his researches. They deal with the reception on the Copernican system of the world at the court of landgrave William IV in Kassel and the use of astronomy at a princely court in the 16th century, exemplified by the Kassel residence. Two contributions discuss a text fragment in Kepler's Astronomia Nova and the dimensions of the geo- and heliocentric systems of the world in Kepler's Mysterium Cosmographicum. Other contributions deal with mathematical aspects un Kepler's exchange of letters, the biography of Kepler's discussion partner Ph. Feselius, as well as the early reception of the Tabulae Rudolphinae in the calendar literature, telescopes in Kepler's time, Chr. Scheiner's optical theory of the eye, and finally in the continuation of the heliocentric world system by Otto von Guericke's natural philosophy and science. In conclusion, the documents of the planned call of Kepler to Rostock university, as well as the first publication of a recently found, hitherto unknown letter by Kepler.

  2. Harmonical cosmology: Johannes Kepler and Athanasius Kircher. (German Title: Harmonikale Kosmologie: Johannes Kepler und Athanasius Kircher)

    NASA Astrophysics Data System (ADS)

    Rebohm, Simon

    2011-08-01

    The connection between musical theory and astronomy is an aspect of Pythagorean cosmology, which still played a role in the 17th century, and was advanced at that time in very different ways: while Johannes Kepler conceives a proper geometrical system of harmonics and tries to connect it with accurate astronomical data, Athanasius Kircher, harshly criticising Kepler's ideas, sets a qualitative system against it, which is based on analogies. The reason for this discrepancy is not only found in the basically different systems of harmonics of both researchers, but also in the different positions that were taken by both within the controversy about the heliocentric system of the world.

  3. Transiente Abstrahlung, Einkopplung und Streuung der Schlitzantennen im EMV-Umfeld

    NASA Astrophysics Data System (ADS)

    Ehlen, T.

    2014-11-01

    The radiation, reception and reradiating of the thin slot antenna with arbitrary transient time waveforms are derived in time domain and compared with numerical field simulation results. The equations are suitable for estimating typical pulsed EMI-Interference responses and penetration through loaded and not loaded slots in metal shields like bluetooth and wlan antennas including the radiation impedance. Examples are given for LEMP, NEMP and HPEM waveforms. The derived formulas are transferred in system theory based block diagrams.

  4. Naturwissenschaftliche Methoden zur Beurteilung von Gemälden und Graphik

    NASA Astrophysics Data System (ADS)

    Kühn, Hermann

    1983-09-01

    Stylistic criteria are sometimes not sufficient in order to differentiate with certainty between copies or fakes and originals. Analyses of paints, supports and artistic technique may give an indication for the earliest possible date of a painting or a work of graphic arts. For example, supports made from oak, fir, spruce and beech can be dated by yearring analysis (dendrochronology). Exclusively methods on micro and ultramicro scale are suitable for the identification of various materials, i.e. microchemistry, emission spectrographic analysis, X-ray powder diffraction because only very tiny samples can be taken from the object.

  5. Friedensdid Aktische Bausteine für Ausbildung, Unterricht und Sozialarbeit

    NASA Astrophysics Data System (ADS)

    Esser, Johannes

    1983-09-01

    In the context of the peace movement in the Federal Republic of Germany, certain central basic elements of peace activity at higher education institutions, school and/or in social welfare work are considered. Principles and objectives of effective teaching and practice in discerning peace work are focussed upon against a background of disturbing and menacing influences both within and between nations, increasingly threatening existence itself. Endeavours to achieve reform capable of changing society should be marked by the development and realisation of a repugnance of violence, civil disobedience and social sensitivity, and demonstrated in action and by specific measures by the general public. This supersedes by far the traditional set-up of peace education (so called) in educational institutions and areas of social work up to the present time.

  6. Hölderlin and astronomy. (German Title: Hölderlin und die Astronomie)

    NASA Astrophysics Data System (ADS)

    Schmidt-Kaler, Theodor

    Hölderlin, in many poems, in his great novel Hyperion and in his prose speaks of Heaven, Ether and Sky, Sun and Helios, Moon, stars, Castor, Pollux, Urania, Sirius, Orion, the Pleiades. In a letter of 17 November 1791 the poet expressly mentions his interest in astronomy. I have surveyed Hölderlin's poems for traces of this interest. In his late period the poet mentions in addition the Milky Way and comets, probably inspired by the Great Comet of 1807. The comet embodies for him a metapher of the great pure man.

  7. Multikulturelle Und Transkulturelle Erziehung: Zwei Wege Zu Kosmopolitischen Kulturellen Identitäten

    NASA Astrophysics Data System (ADS)

    Schöfthaler, Traugott

    1984-03-01

    `Preserving cultural identity' and `achieving social integration' are among the few universally accepted objectives of educational policy and — as the article shows — support two mutually-opposing positions. As a result, there has been a gradual devaluation of universal values, which is examined by comparing educational programmes for culture minorities in the USA, Australia, and the Federal Republic of Germany. The underlying cross-cultural dilemma is manifested in some desired and undesired effects of preserving identity and encouraging integration. On the one hand, promoting educational opportunities for cultural minorities contributes towards safe-guarding endangered cultural identities but also towards cultural segregation. On the other hand, not to adopt such promotional measures may facilitate social integration but only at the price of equality of opportunity. As ways out of the dilemma, two strategies of intercultural education are discussed which, although they are orientated towards cosmopolitical identities, are at the same time attractive to majorities and minorities in different ways. The so-called `multicultural education' is directed towards expanding cultural knowledge generally, which — in the case of minorities — is achieved through additional development of new techniques of learning. The concept of `transcultural education' differs from this insofar as it aims at changing the interpretative patterns and modes of thought of members of cultural majorities and minorities alike. In analysing the theoretical background and the educational policies behind both strategies, emphasis is placed on the `stigma of compensation' which either makes multicultural education seem less attractive to the cultural majority or reduces measures to the colourful planning of curriculum. In contrast to this, further elaboration of the transcultural concepts of `bi-cultural' and `bi-cognitive' education, as a way out of the dilemma of identity and integration, is proposed.

  8. The Sturm und Drang of anabolic steroid use: angst, anxiety, and aggression

    PubMed Central

    Oberlander, Joseph G.; Henderson, Leslie P.

    2014-01-01

    Anabolic androgenic steroids (AAS) are illicitly administered to enhance athletic performance and body image. Although conferring positive actions on performance, steroid abuse is associated with changes in anxiety and aggression. AAS users are often keenly invested in understanding the biological actions of these drugs. Thus, mechanistic information on AAS actions is important not only for the biomedical community, but also for steroid users. Here we review findings from animal studies on the impact of AAS exposure on neural systems that are crucial for the production of anxiety and aggression, and compare the effects of the different classes of AAS and their potential signaling mechanisms, as well as context-, age- and sex-dependent aspects of their actions. PMID:22516619

  9. Verbesserte Elemente der RR-Lyrae-Sterne IQ Bootis, V651 Aurigae und BQ Lyrae

    NASA Astrophysics Data System (ADS)

    Maintz, Gisela

    2015-04-01

    CCD observations of neglected RR Lyrae stars were taken at my private observatory. IQ Boo is a RRab star with a hump in the rising branch. BQ Lyr shows a weak Blazhko effect. The elements of these stars were revised. Star Max period +- JD [d] [d] IQ Boo 2457213.4681 0.535234 0.000001 V651 Aur 2457040.4056 0.617715 0.000003 BQ Lyr 2455703.4120 0.4350488 0.0000002

  10. Die Makrofauna und ihre Verteilung im Nordost-Felswatt von Helgoland

    NASA Astrophysics Data System (ADS)

    Janke, Klaus

    1986-03-01

    The macrofauna and its distribution in the sheltered, rocky intertidal zone of Helgoland (North Sea) was studied at 9 vertically and/or morphologically different stations from March to September in 1984. Seasonal variations in the communities were described based on each species' “conspicuousness”. A total of 172 species was found. The macrofauna shows a zoned pattern, but also the different substrata, for example, affect its distribution. The number of species increases from the upper intertidal to the upper sublittoral zone from 23 to 133 species. The upper intertidal is characterized by Littorina saxatilis, Chaetogrammarus marinus and Hyale nilssonii. Typical and abundant species of the middle and lower intertidal are Flustrellidra hispida, Littorina mariae/obtusata, Littorina littorea, Mytilus edulis and Spirorbis spirorbis. The upper sublittoral zone is characterized by Gibbula cineraria and increasing species numbers of Bryozoa, Nemertini and Opisthobranchia. Only few species (e.g. Dynamena pumila, Laomedea flexuosa, Polydora ciliata, Fabricia sabella, Jaera albifrons, Carcinus maenas) occur in the entire intertidal zone. In comparison to other very sheltered shores in Great Britain, which are also dominated by Fucaceae, the macrofauna in the Helgoland intertidal zone lacks several littoral species, such as Patella spp., Monodonta lineata, Gibbula umbilicalis, Littorina neritoides, Chthamalus spp., whereas Littorina littorea and Gibbula cineraria are highly abundant.

  11. Infektion mit Epstein-Barr-Virus und Tumor-Entstehung beim Menschen

    NASA Astrophysics Data System (ADS)

    Kirchner, H.

    1981-08-01

    The Epstein-Barr Virus (EBV) is the only infectious agent for which a close association with human malignant tumors has been clearly demonstrated. These tumors are one type of nasopharyngeal carcinoma which is frequent in parts of East Asia and the Burkitt lymphoma which predominantly occurs in parts of Africa and New Guinea. Nonetheless, the EBV is the causative agent of infectious mononucleosis (IM), a benign, self-limiting lymphoproliferative disease of adolescents. The major difference between the countries in which the EBV-induced tumors occur and those in which IM occurs is the late primary EBV infection in the latter, whereas primary infection with EBV occurs in the first year of life in the former. All theories of viral carcinogenesis have to explain the long latency period between primary infection and tumor growth and how an ubiquitous virus may be oncogenic. Thus, invariably, one has to assume a role of cofactors, which may be of cytogenetic nature or may be represented by additional infections or by chemical agents. Since most modern theories of carcinogenesis consider a multi-step development of tumors, the theory that infection with an ubiquitous virus at the right time of life represents one step to carcinogenesis seems to be tenable.

  12. Verfahren zur Analyse klimatischer und anthropogener Einflüsse auf die Grundwasserstandsentwicklung

    NASA Astrophysics Data System (ADS)

    Wriedt, Gunter

    2017-03-01

    Limitations in applying the Wiener-Multichannel filter to analyze anthropogenic influences on groundwater level dynamics require a new approach independent from reference observation wells. This article presents a simple approach to analyze the relation between groundwater elevations and climate parameters for groundwater monitoring wells. A theoretical "climatic groundwater level series" is derived from monthly climatic water balances considering the transforming effects of the unsaturated zone and local conditions on groundwater level dynamics. Comparing theoretical groundwater levels with observed groundwater level fluctuations allows analyzing the agreement with the temporal dynamics of climatic parameters as well as detecting possible anthropogenic influences. A total of 284 of 573 groundwater observation wells in Lower Saxony show natural groundwater level dynamics, while artificial impacts were found in 221 wells and 68 wells remain unclear. A classification was therefore possible for 88% of the wells. A high model performance was detected for wells without artificial impacts and with minor artificial impacts. A split-sample cross validation proves the predictive capacity of the model for wells with natural dynamics.

  13. Regionale Meeresschutzkooperation und die EU-Gratwanderung der Helsinki-Kommission imOsterweiterungsprozess der EU

    NASA Astrophysics Data System (ADS)

    Imhoff, Heike

    1999-12-01

    The purpose of the lecture is to describe the role of regional marine protection cooperation in the context of international cooperation. My intention is to provide evidence that regional forms of cooperation are an indispensable instrument, in particular against the backdrop of the EU enlargement to the east. Signed at times when the iron curtain still existed, the Baltic Marine Environment Protection Convention was the basis of a first reluctant cooperation between Western and Eastem states bordering on the Baltic Sea. As a result of the fall of the iron curtain and of the accession of Finland and Sweden to the European Union there was a shift in the political structure of the Baltic Sea cooperation. 4 EU member states are represented in the Helsinki Commission. As there is a total of 10 Parties (one of them the Commission of the European Communities) this means that EU countries currently already make up 50% of the Commission. The regulatory instruments of the Helsinki Commission (legally non-binding, yet politically appellative recommendations) and of the EU (directives, regulations etc. which are binding by international law) make it clear that there are serious differences. From the point of view of regional marine protection cooperation, the EC Commission’s involvement in issues of regional marine protection has been linked to both advantages and disadvantages. The pressure created by the EC’s involvement in certain issues can be considered an advantage, since it requires that certain issues are continually addressed in the framework of regional marine protection cooperation. For example, in the wake of the adoption of the nitrates directive special rules were established in the framework of the Helsinki Commission. However, the exclusive competence for individual areas (e.g. fisheries) claimed by the EC Commission sometimes has negative effects. Those member states of the Helsinki Commission which are also EU member states may formally only accept rules which comply with existing EC legislation. In addition, the EC Commission, which is a Party to the Helsinki Convention, strictly monitors compliance with the limits set by their exclusive resoonsibility and the responsibility of the Helsinki Commission. This demeanour of the EC Commission regularly creates problems in cases where EC rules do not take into account the regional characteristics of the Baltic Sea area and in particular when they do not adequately honour the position of the Russian Federation as a member state with equal rights. What is the special role of the Helsinki Commission compared to the Barcelona cooperation (Mediterranean Sea protection) and to the OSPAR cooperation (protection of the North East Atlantic)? It is particularly important that those OSPAR member states which are not also EU members enforce a comparatively high level of environmental protection anyway. This does not automatically apply to states like Poland or the Baltic Republics, most of which, however, will join the EU in the foreseeable future, but whose environmental standards partly still require significant adjustment to the EC level. In addition, the Russian Federation, which will not become an EU member even in the foreseeable future, plays, a special role. At this point the significant general political role of the Helsinki Commission must be mentioned. According to the unanimity principle it only adopts recommendations which receive the support of all member states, i.e. also by the mentioned eastern riparian states. Sometimes criticism is voiced that the different forms of regional cooperation would lead to duplication of work in the case of issues which are regulated by EC directives anyway and that they should therefore be rejected. It is said that the candidate countries should rather give priority to the adjustment to the EC protection level and that there was no need for an intermediate stage at the regional level. This attitude completely ignores the necessity of regional and specific political solutions for a given geographical region. However, experience of parallel membership in the regional cooperation on protection and in the EU shows that in the long run the two aspects can be combined. There are signs indicating that the EC increasingly recognises the value of regional forms of cooperation.

  14. Das Gymnasium Zwischen Tradition und Modernen Bildungsanspruchen (The Gymnasium between Tradition and Modern Educational Requirements).

    ERIC Educational Resources Information Center

    Heller, Kurt A.

    2003-01-01

    Provides brief history of the German Gymnasium as a traditional European secondary school system with a preparatory function for higher education. Reviews the main goals of the gymnasium. Asks what role the gymnasium plays as a learning environment for gifted students. Discusses the politico-educational consequences and demands on the gymnasium.…

  15. Biografie, Lernen und Familienthemen in Generationsbeziehungen (Biography, Learning, and Family Issues across Generations).

    ERIC Educational Resources Information Center

    Ecarius, Jutta

    2003-01-01

    Discusses empirical findings of a qualitative research project covering three generations of twentieth century families. Examines the importance of family topics for biographical learning. Argues that family topics leave their mark on biographical constructions and influence acting, thinking and perceiving, and the shaping of the biography…

  16. Schulleistungsstudien und Soziale Gerechtigkeit (Studies on School Achievement and Social Justice).

    ERIC Educational Resources Information Center

    Arnold, Karl-Heinz

    2001-01-01

    Demonstrates that a high degree of fairness may be achieved in international comparative research on school achievement, using the Third International Mathematics and Science Study (TIMSS) as an example and employing the methods of advanced pedagogical-psychological diagnosis. Includes references. (CMK)

  17. 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.…

  18. Die Cnidogenese der Octocorallia (Anthozoa, Cnidaria): I. Sekretionund Differenzierung von Kapsel und Schlauch

    NASA Astrophysics Data System (ADS)

    Schmidt, H.

    1981-12-01

    The ultrastructural differentiation of capsule and its relation to tube development is described in several Octocorallia species (Alcyonaria: Alcyonium digitatum, Parerythropodium coralloides, Cornularia cornucopiae, Paralcyonium elegans; Pennatularia: Pteroeides spinosum, Veretillum cynomorium; Gorgonaria: Pseudopterogorgia aerosa), all of which have only one type nematocyst. In the Octocorallia, capsule and tube are secreted successively by the Golgi apparatus associated with a primary centriolar complex. During the secretion of the external tube, the outer capsular wall (sclera) is structurally differentiated; inside the capsule the material of the inner capsular wall is separated from the later capsular content (matrix). The primary wall differentiation enables the capsules to “grow” after capsular secretion has been completed. Following tube secretion, the external tube is completely transferred into the capsule, without the tube wall being transformed into capsular wall, as previously suggested (Westfall, 1966; Ivester, 1977). During early invagination of the tube wall, the coarse, granulated matrix of the external tube is transferred into the internal tube. From this material the spines are developed, which are observed before the tube is completely transferred into the capsule. By a secondary wall differentiation the previously structureless inner capsular wall changes to a complex structure, extending again the capsule, thus mixing the capsular content and enabling the tube to shift to a position, which corresponds with that of mature capsules. These observations demonstrate for the first time the differentiation of the capsule and its close relationship to the differentiation of the tube in nematocysts of Octocorallia.

  19. BOOK REVIEW: Astronomie und Anschaulichkeit. Die Bilder der populaeren Astronomie des 19. Jahrhunderts

    NASA Astrophysics Data System (ADS)

    Duerbeck, H. W.; Utzt, S.

    2004-12-01

    Today, popularisation of science also means "pretty pictures": images that accompany articles in magazines and webpages, or are squeezed between the covers of so-called coffee-table books, and the reviewer pleads guilty to having added to this growing pile. But how did this "disease" came into existence? Susanne Utzt, a manager, journalist and student in the history of sciences, has dedicated her master thesis to the investigation of the growing influence of such pictures in the popularisation of astronomy. She has analyzed French and German popular texts by Arago, Guillemin, Flammarion, as well as Littrow, Maedler and Max Wilhelm Meyer that mainly appeared in the second half of the 19th century. Earlier astronomy books just had a few foldout pages with mathematical figures, as the author exemplifies by Littrow's first edition of "Die Wunder des Himmels" of 1834-36. But Flammarion with his "Astronomie Populaire", changed everything: 51 "art pages" and more than 300 figures in the text made it a true picture book, and about a third of Utzt's work is dedicated to its analysis. (In passing, it should be noted that the first 1880 edition of Flammarion's book did not yet contain the "art pages"; the author quotes such pages and text figures according to a German edition of 1907). Besides sober diagrams illustrating the solar system, and telescope drawings showing planetary surfaces and the structure of the solar photosphere, Flammarion includes poetic illustrations like a couple at the seashore at sunset; a scene showing dying Copernicus, already flanked by two angels, as he receives a copy of his De Revolutionibus; or a painting showing a flock of mammoths in an ancient landscape. In most cases, the images are chosen to illustrate the text, but sometimes the text "makes a detour" to permit the inclusion of a pretty picture. Flammarion's book contains drawings illustrating the sphericity of the earth, which appeared in almost identical form in Apian's Cosmography of 1539, and it includes images that became only a reality after space travel to the planets of the solar system became possible: thus Flammarion's images probe the past and the future, they cover a time interval of about 450 years! I think that there is a direct route from Flammarion's images "Jupiter, as seen from one of its moons" or "The rings of Saturn, as seen from Saturn", to the space art of Chesley Bonestell, as it appeared in the early 1950s in the book "The Conquest of Space" by Willy Ley, as well as in popular journals. Besides national prestige to be superior in rocketry and space travel, it was the fantasy and enthusiasm of the general public, as spurred by paintings like those of Bonestell, that made the space missions and the planetary exploration of the last decades possible. In 1880, a certain Father Schlosser (1880) expressed his fear that the flood of images would lead to a loss of fantasy, to sensationalism and superficiality. In modern society, illustrated newspapers, magazines and television may really have caused such a scientific analphabetism and superficial knowledge in wide circles. On the other hand, Wilhelm Foerster (1889) expressed the hope that the layman can be stimulated by sensual pleasures in his pursuit of insight, and even to a collaboration in science, and his hope was also fulfilled: nowadays, more hobby and professional scientists are active than in past times; "hobby science", if done in a professional way, can form a valuable supplement to astronomical science; and honestly, how many present-day astronomers have arrived at their profession by watching astronomical TV programs, reading science fiction novels, or illustrated astronomy books that they once received as a gift? Utzt states that knowledge is generated and transmitted more and more by images, and propagated to the public by means of visualisations. Thus, a critical investigation of the influence of such images is needed, and the historical knowledge of the practice of visualisations in science and popularisation can form a basis for such a study. The somewhat slim volume of this series is embellished with 35 illustrations. It offers interesting insights in the development of illustrations in popular scientific books, their use, and also sometimes their failure. It also inspires the reader to embark on further studies where the author, because of lack of source material, because of self-imposed limits of investigation, or perhaps simply because of lack of time, has halted.

  20. Adaptive Herd- und Fahnencharakterisierung als Voraussetzung für einen effizienten Modellaufbau unter heterogenen Standortbedingungen

    NASA Astrophysics Data System (ADS)

    Martac, Eugeniu; Oppermann, Axel; Körner, Johannes; Thielecke, Sonja; Ihle, Tino; Bittens, Martin; Weiß, Holger; Horn, Herbert; Romey, Andreas

    2012-03-01

    The Voigtländer camera production site in Braunschweig was operated until 1972. The facility's use of chlorinated solvents for grease removal led to significant soil and groundwater contamination. The investigation and remediation methods that have been used at the site have not resulted in an acceptable level of remediation. Given the heterogeneous conditions, the site appears to be an excellent location for assessing the effectiveness of adaptive characterization strategies for investigations of contamination by chlorinated solvents. The Voigtländer source area no. V is being used as a demonstration site to assess the efficiency of different investigation and remediation methods under heterogeneous conditions. An iterative (adaptive) investigation process was conducted with sequential improvements based on increased site understanding. The lithologic and hydraulic features that could create potential migration pathways were identified, and the spatial extent of the contaminant body within the source area and, by means of control planes, within the plume was delineated. Related 2D and 3D images of the site model provide solid support for assessments of the relative effectiveness of various remediation alternatives.

  1. [Digital radiography und fluoroscopy. Basics of technology, imaging properties and applications].

    PubMed

    Loose, R; Busch, H P; Wucherer, M

    2005-08-01

    For 110 years, x-rays and special x-ray films have been used in medical diagnostics. New developments in the field of x-ray techniques, and especially new computer applications, have led to new imaging techniques which have substantially expanded the spectrum of radiological examinations. In spite of significant technological and medical advances in the field of MRI and multidetector-CT, radiographic images of the lungs, skeleton and organs still comprise up to 80% of the routine radiological workload. The increasing availability of digital detectors has led to the continual replacement of conventional film/screen systems. The inclusion of digital mammography was delayed due to the higher requirements for spatial resolution. For about 2 years, dynamic flat panel detectors have started to replace the image intensifier which has been used in fluoroscopy for 40 years.

  2. Content and Language Integrated Learning by Interaction. Fremdsprachendidaktik inhalts-und lernerorientiert. Volume 26

    ERIC Educational Resources Information Center

    Kupetz, Rita, Ed.; Becker, Carmen, Ed.

    2014-01-01

    Content and Language Integrated Learning (CLIL) is an established approach to support multilingualism in Europe by teaching various school subjects in an additional language. The practices used, however, vary considerably. Our book considers this diversity by looking at CLIL scenarios, defined as learning environments supporting content learning,…

  3. Experiential Learning: Lessons Learned from the UND Business and Government Symposium

    ERIC Educational Resources Information Center

    Harsell, Dana Michael; O'Neill, Patrick B.

    2010-01-01

    The authors describe lessons learned from a limited-duration experiential learning component of a Master's level course. The course is open to Master's in Business and Master's in Public Administration students and explores the relationships between government and business. A complete discussion of the Master's in Business and Master's in Public…

  4. Wechselwirkungen zwischen Grundwasser und Oberflächenwasser an einem Tieflandfluss (Spree)

    NASA Astrophysics Data System (ADS)

    Nützmann, G.; Lewandowski, J.

    2009-09-01

    Water exchange processes in the floodplain of a lowland groundwater-surface water system are studied on the basis of a study site near Freienbrink, NE Germany. The boundaries of this site are formed by an oxbow and the current bed of the river Spree, section Müggelspree. Surface and ground water levels were collected in 12 piezometers and at two recording stage gauges of a 300 m long transect throughout a one-year-period. Due to water level fluctuations, alternating periods of infiltration and exfiltration have been observed. However, most of the time groundwater flux is directed into the river Spree and river water infiltration events into the aquifer are usually short and of minor importance. Due to clogging of the oxbow bed, the hydraulic contact between the oxbow and the adjacent aquifer is marginal. These features are modelled quantitatively using MODFLOW in order to simulate ground water flow in the local aquifer.

  5. Verminderte Tiefbrunnenergiebigkeit durch Versandung und Versinterung bei Veränderung der Grundwasserchemie

    NASA Astrophysics Data System (ADS)

    Knuth, Christoph; Wisotzky, Frank; Becke, Norbert

    2017-03-01

    In three deep wells of a water works in the Lower Rhine Valley (Germany) decreasing well yield has been observed. To investigate the reasons for this decline, solids analysis (microscopy, Cinorg measurements, XRD-, SEM-analysis) was completed and hydrogeochemical calculations were carried out. The samples examined from the bottom of the wells indicate both hydromechanical entry of sand from the aquifer into the well, and formation of incrustations in the form of calcite within the well. The water analysis results show that almost all measured ion concentrations have increased over the past 10 years, which indicates a general change of the hydrochemical conditions of the aquifer. Hydrogeochemical models suggest that oversaturation exists regarding the mineral phases iron hydroxide and calcium carbonate, and therefore the formation of incrustations is possible.

  6. Wien und Wein: Connecting Sound and Symbol in First-Year German.

    ERIC Educational Resources Information Center

    Anderson, Philip N.

    1984-01-01

    Describes a technique to train students to associate correct pronunciation of German with the graphemes as soon as they see them. When a student misreads a word, he or she is asked to compare that word with very common words which are almost never mispronounced or misspelled, such as "ein,""die," and "deutsch." (SED)

  7. Wortschatzliste und Synonyme: Hermann Hesse, "Siddhartha" (Vocabulary List and Synonyms for Hermann Hesse's "Siddhartha").

    ERIC Educational Resources Information Center

    Schwartzburg, John A.

    This vocabulary and synonym list for Hermann Hesse's "Siddhartha" (presently on the German Advanced Placement Program required reading list) is keyed to the Dunham and Wensinger edition published by the Macmillan Company. Selected German vocabulary found on each page of the text is briefly translated into English or clarified through the…

  8. Uniform National Discharge Standards (UNDS) for Vessels of the Armed Forces

    EPA Pesticide Factsheets

    The Uniform National Discharge Standards homepage links to a description of the EPA's rulemaking process and provides information to the public on outreach efforts and answers some frequently asked questions.

  9. Towards Automatic Threat Recognition

    DTIC Science & Technology

    2006-12-01

    York: Bantam. Forschungsinstitut für Kommunikation, Informationsverarbeitung und Ergonomie FGAN Informationstechnik und Führungssysteme KIE Towards...Informationsverarbeitung und Ergonomie FGAN Informationstechnik und Führungssysteme KIE Content Preliminaries about Information Fusion The System Ontology Unification...as Processing Principle Back to the Example Conclusion and Outlook Forschungsinstitut für Kommunikation, Informationsverarbeitung und Ergonomie FGAN

  10. Quartet excitations in atomic nuclei

    NASA Astrophysics Data System (ADS)

    Cseh, J.

    2016-06-01

    The recently invented phenomenologic and semimicroscopic algebraic quartet models, as well as their relations to other approaches are discussed. The semimicroscopic model is applied to the 20Ne and 28Si nuclei.

  11. Formation of hyperdeformed states by neutron emission from a dinuclear system

    SciTech Connect

    Zubov, A. S.; Antonenko, N. V.; Sargsyan, V. V.; Adamian, G. G.; Scheid, W.

    2010-02-15

    The hyperdeformed nuclei treated as dinuclear or quasimolecular configurations are suggested to be directly produced in heavy-ion reactions at bombarding energies near the Coulomb barrier. The excited dinuclear system formed in the entrance channel of the heavy-ion collision can be cooled down by neutron emission to be transformed into the hyperdeformed nuclear system. This transition from the excited dinuclear system to a hyperdeformed configuration is described within the statistical approach. The reactions {sup 48}Ca+{sup 124,128,130,132,134}Sn, {sup 48}Ca+{sup 136,138}Xe, {sup 48}Ca+{sup 137,138,140}Ba, {sup 40}Ca+{sup 83,84}Kr, {sup 48}Ca+{sup 83,84,86}Kr, {sup 40,48}Ca+{sup 40,48}Ca, {sup 58,60}Ni+{sup 58,60}Ni, and {sup 40}Ca+{sup 58}Ni are suggested for the population of hyperdeformed states. The production cross sections, quadrupole moments, and moments of inertia of hyperdeformed states formed in these reactions are calculated, and the optimal conditions for the experimental identification of such states are proposed.

  12. 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.

  13. {alpha} cluster states in {sup 44,46,52}Ti

    SciTech Connect

    Fukada, M.; Takimoto, M. K.; Ogino, K.; Ohkubo, S.

    2009-12-15

    {alpha} decaying states of {sup 44,46,52}Ti were investigated with angular correlation functions between t and {alpha} with the {sup 40,42,48}Ca({sup 7}Li,t{alpha}){sup 40,42,48}Ca reactions at E=26.0 MeV. Many {alpha} cluster states were newly observed in the 10-15 MeV excitation energy of {sup 44}Ti and their spin-parities were assigned, in which J{sup {pi}}=7{sup -} state was found at 11.95 MeV as a candidate for the member of the K=0{sub 1}{sup -} negative parity band. In {sup 46}Ti many {alpha} cluster states were also found in the 11-17 MeV excitation energy with the {sup 42}Ca({sup 7}Li,t{alpha}){sup 42}Ca reaction, though its strength is weak compared with {sup 44}Ti. No {alpha} cluster states were detected for the {sup 48}Ca({sup 7}Li,t{alpha}){sup 48}Ca reaction, in which the number of coincidence events decaying from {sup 48}Ca was very small.

  14. The master and the telescopes - the interplay between astronomy and optics in history (German Title: Der Meister und die Fernrohre - Das Wechselspiel zwischen Astronomie und Optik in der Geschichte)

    NASA Astrophysics Data System (ADS)

    Hamel, Jürgen; Keil, Inge

    The use of the telescope for astronomical observations since 1609 was one of the milestones in the celestial research. The contributions in this volume present new insights into the invention of the telescope and its relations to reading stones and spectacles, present investigations of special telescope types of early manufacturers, and analyze the telescopes of some historical observatories and the investigations carried out with them. Other contributions deal with the pictorial appearance of telescopes in baroque art, the connection of telescopes with photography, as well as the development of reflectors in the 20th century. The volume is dedicated to Rolf Riekher, an internationally established specialist ior the history of the telescope, on the occasion of his 85th birthday.

  15. Zwischen Wollen, aber nicht können und Können, aber nicht wollen: Übergangsprobleme von Jugendlichen in Japan am Beispiel der „Freeter`` und „NEETs``

    NASA Astrophysics Data System (ADS)

    Eswein, Mikiko; Pilz, Matthias

    2012-08-01

    Caught between wanting but not being able to, and being able, but not wanting to: Transitional problems among Japanese youths based on the examples of "Freeters" and "NEETs" - The study of processes of transition from the education system to employment is particularly important in light of youth unemployment. In Japan this transition process is often declared to be successful. In recent years, however, numerous signs have indicated a change in the situation. This article analyses this problem based on the examples of two Japanese social groups, "Freeters" and "NEETs". These terms refer to young adults who do not immediately move into to regular employment. The article begins by analysing the causes, then comments on education policy measures undertaken to tackle the issue. Drawing on scientifically grounded models it is shown that both social groups are characterised by meagre formal school qualifications. Social background, by contrast, is not particularly relevant; although there are hints that parents' financial means play an increasingly important role in determining whether a young person attends a high-level educational institution. Although public opinion in Japan frequently attributes values and attitudes to these groups that deviate from the norm, this is not conclusively supported by existing empirical findings. Consequently, the reasons for these transitional problems tend to be perceived as being connected to the difficult labour market situation resulting from the ongoing economic crisis. In addition to certain education policy initiatives, Japan will therefore rely heavily in future on the ability to effectively manage the integration of its shrinking cohorts of school and university graduates.

  16. James Baldwin und das Rassenproblem in den USA. Unterrichtsprojekt zum Komplex "Texte und ihre gesellschaftliche Bedingtheit" (James Baldwin and the Race Problem in the USA. Teaching Project in the Series "Texts and their Social Context")

    ERIC Educational Resources Information Center

    Kerschgens, Edda

    1977-01-01

    Reports on an 18-hour teaching project with students at a teachers' college. Four Baldwin texts were used. Questions considered included whether Baldwin's treatment of the race problem reveals any changes or shifts of emphasis. Suggestions are made for adaptation to teaching in grades 11-13. (Text is in German.) (IFS/WGA)

  17. The Altdorf mathematics and physics teacher Abdias Trew (1597-1669): astronomer, astrologer, calendar maker and theologician. (German Title: Der Altdorfer Mathematik- und Physikdozent Abdias Trew (1597-1669): Astronom, Astrologe, Kalendermacher und Theologe)

    NASA Astrophysics Data System (ADS)

    Gaab, Hans

    Although Abdias Trew (1597-1669) had studied theology, he obtained the chair of mathematics at Altdorf University, and in 1650, the chair of physics was added. In 1654, in addition, he became the ast official calendar maker of the city of Nuremberg. He is kept in memory as the last important protestant astrologer who tried to provide scientific foundations for this field. In this context, his adherence to the Lutheran confession played a role. Although he aimed at integrating new insights, he adhered to his end to Aristotelian physics, since it served his Wittenberg professors since his student days as a foundation of Lutheran dogmatics. After an extensive biography, separate chapters deal with Trew's works in mathematics, geography, optics, mechanics and musical theory, his writings in astronomy, especially those dealing with comets, as well as his “reformation astrology” in connection with the opinions of Melanchthon, Kepler and others. Trew also took part in the discussions about the introduction of the Gregorian calendar, which was going on during the whole 17th century. After short biographical sketches of some of his contemporaries, the book closes with an extensive bibliography of Trew's writings, manuscripts and letters.

  18. Der Begriff des "Ki" und die japanische Padagogik: Uber Konflikte zwischen westlicher und japanischer Padagogik (The Concept of "Ki" and Japanese Pedagogy: On Conflicts between Western and Japanese Pedagogics).

    ERIC Educational Resources Information Center

    Fujikawa, Nobuo

    1997-01-01

    Sketches the characteristics of the Japanese educational tradition and analyzes conflicts between modern western pedagogies and traditional education. Argues that Japanese socialization processes stress a specifically Japanese construction of the "self" and of behavior. Concludes that Japanese educators should be more aware of this…

  19. ANALYSIS OF ORGANOSILICON COMPOUNDS IV SEPARATION AND DETERMINATION OF METHYLVINYL-CHLOROSILANES AND VINYLCHLOROSILANES BY GAS CHROMOTOGRAPHY (ANALYSE VON ORGANOSILICIUM-VERBINDUNGEN IV. TRENNUNG UND BESTEMMUNG VON METHYLVINYLCHLORSILANEN UND VINYLCHLORSILANEN MITTELS),

    DTIC Science & Technology

    GAS CHROMATOGRAPHY), (*SILICON COMPOUNDS, SEPARATION, ORGANIC COMPOUNDS, SILANES, CHEMICAL ANALYSIS, THERMAL CONDUCTIVITY, NITROGEN, RECORDING SYSTEMS, IDENTIFICATION, VOLUMETRIC ANALYSIS, DISTILLATION, CZECHOSLOVAKIA.

  20. TIMSS und PISA- Chancen eines neuen Anfangs in Bildungspolitik, -Planung, -Verwaltung und Unterricht. Endlich ein Schock mit Folgen? (TIMSS and PISA -- Prospects of a Fresh Start in Educational Policy and the Monitoring of the School System?).

    ERIC Educational Resources Information Center

    Roeder, Peter Martin

    2003-01-01

    Claims that the Third International Mathematics and Science Study (TIMSS) and the Program for International Student Assessment (PISA) represent a leap forward in the quality of comparative international research on schooling. Discusses prospects of achieving a consensus among educational policy makers on the reforms suggested in both study…

  1. Research on Teaching and the Theory and Practice in Teacher Training. DPA Helsinki Investigations IV = Unterrichtsforschung und die Theorie und Praxis in der Lehrerausbildung. Papers presented at an International Symposium (Helsinki, October 2-3, 1980). Research Report 4.

    ERIC Educational Resources Information Center

    Komulainen, Erkki, Ed.; And Others

    Eight papers presented at an international symposium on teacher education research are featured in this document. Excerpts from the opening speech by Erkki A. Niskanen, Dean of the Faculty of Education at the University of Helsinki, outline research projects being carried out by teacher educators at the university. A paper by Yrjo Engestrom,…

  2. H.C. Schumacher - Center of international communication in astronomy and mediator betwen Denmark an Germany. (German Title: H.C. Schumacher - Zentrum der internationalen Kommunikation in der Astronomie und Mittler zwischen Dänemark und Deutschland)

    NASA Astrophysics Data System (ADS)

    Hamel, Jürgen

    As the editor of the ``Astronomische Nachrichten'', H.C. Schumacher played an outstanding role among the astronomers of the first half of the 19th century. Altona, his place of activity, belonged to the kingdom of Denmark. Both the foundation of the ``Astronomische Nachrichten'' and its existence depended for several decades on the support by the Danish kings and high-ranking officials at the Copenhagen court. This paper analyses these questions on the basis of previously unused archival sources and discusses also Schumacher's life and his relations to the royal dynasty.

  3. 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…

  4. Struktur und Bindung in Übergangsmetall-Fluoriden MIIMeIVF6. Neutronenbeugungs-Strukturuntersuchungen an CaSnF6, FeZrF6, und CrZrF6

    NASA Astrophysics Data System (ADS)

    Mayer, H. W.; Reinen, D.; Heger, G.

    1983-11-01

    Compounds MIIMe IVF 6 requently undergo phase transitions from the cubic ordered ReO 3 to the trigonal LiSbF 6 structure when lowering the temperature. In case of a strongly Jahn-Teller unstable cation in the MII position additional phases may occur. Results of powder neutron-diffraction studies on CaSnF 6, FeZrF 6, and CrZrF 6 at different temperatures are reported. The high-temperature phases have the space group Fm3 m; the F - ligands are either statistically displaced from the MIIMe IV directions or undergo a strong thermal motion perpendicular to these directions ( ∢M II FMe IV: 165-180°). The thermal ellipsoids of the CrF bonds are strongly indicative of a dynamical Jahn-Teller effect in addition. In the low-temperature phases of CaSnF 6 and FeZrF 6 (space group R overline3) the ∢M II FMe IV is more distinctly bent (⋍155-160°). CrZrF 6 undergoes two reversible phase transitions, which are determined to occur at 415 ± 5 K (cubic → tetragonal, dynamic to static Jahn-Teller distortion of CrF 6 octahedra and 150 ± 10 K (tetragonal → (pseudo)monoclinic).

  5. Shared Services Implementierungen in Untemehmen: Eine funktionsuebergreifende und kontextbezogene Analyse von Gestaltungsparametem, Herausforderungen und Handlungsstrategien (Shared Services Implementations in Companies: Across Functional and Contextual Analysis of Design Parameters, Challenges and Strategies)

    DTIC Science & Technology

    2015-06-15

    Prozessmigration kann dabei im Ganzen mittels eines , Big - Bang " Verfahrens oder in einem stufenweisen Prozess erfolgen. Erfolgt die Aufnahme des...creation of Shared Services: Transaction cost theory ; Type and amount of transaction costs; Implications; Resource-oriented theory : Resources; Skills...and core competencies; Dynamic Capabilities; Implications; Value-based theory : Value contributions and value drivers of internal support units

  6. Implementation of "social and communicative competencies" in medical education. The importance of curriculum, organisational and human resource development.

    PubMed

    Pruskil, Susanne; Deis, Nicole; Druener, Susanne; Kiessling, Claudia; Philipp, Swetlana; Rockenbauch, Katrin

    2015-01-01

    Zielsetzung: Ziel dieser Arbeit ist es, Lehrenden und Curriculumsplanern die Bedeutung der Curriculums- (CE), Personal- (PE) und Organisationsentwicklung (OE), bereits in der Planungsphase eines Projekts aufzuzeigen. Diese können dann gezielt genutzt werden um Veränderungsprozesse bei der Einführung und Etablierung von Curricula im Bereich kommunikativer und sozialer Kompetenzen im Medizinstudium erfolgreich zu beeinflussen und zu steuern.Vorgehen und Ergebnisse: Im Rahmen eines mehrstufigen Entwicklungsprozesses, in dem insbesondere zwei interfakultäre Workshops des GMA-Ausschusses „Kommunikative und soziale Kompetenzen“ im Zentrum standen, wurde aufbauend auf die verfügbare Literatur und den Erfahrungen von Kommunikationsexperten eine Empfehlung zur CE im Bereich „Kommunikativer und sozialer Kompetenzen“ erarbeitet. Die „Undeloher-Empfehlung“ (siehe Anhang ) beinhaltet eine Zusammenstellung von Empfehlungen und Leitfragen, die sich an den verschiedenen Phasen der CE orientiert. Zusätzlich wurden allgemeine Herangehensweisen und Empfehlungen der Organisations- und Personalorganisation integriert, die sich im Prozess der CE als besonders relevant herausstellten. Damit beinhaltet die „Undeloher-Empfehlung“ für jede einzelne Phase der Curriculumsentwicklung eine Orientierung, was in bezug auf das Curriculum, die Organisation und das Personal für eine erfolgreiche Implementierung von longitudinalen Curricula zu beachten ist. Neben theoretischen Modellen fließen insbesondere der langjährige Diskussionsprozess und die persönlichen Erfahrungen einer Vielzahl von Curriculumsplanern und Lehrenden ein. Fazit: Die „Undeloher-Empfehlung“ kann die Vorbereitung und Begleitung von Implementierungsprozessen von Curricula im Bereich kommunikative und soziale Kompetenzen unterstützen. Ihre Anwendung wurde im Rahmen der Workshops auf konkrete Beispiele überprüft und wurde von den beteiligten Lehrenden und Curriculumsplanern als sehr hilfreich

  7. The Maritime Environment, International Conference and Exhibition "Waste Water Treatment Technologies for Ships"

    DTIC Science & Technology

    1998-01-01

    survivability. Since the fuel tanks are always full of liquid, there is no chance of setting off an explosion in an empty tank. Also, the tanks provide...Textil- und Papierfasern, Belebtschlamm, mineralische, pflanzliche und tierische Ole und Fette, Flocken, Staub , pflanzliche und tierische Zellverb

  8. TÜV - Zertifizierungen in der Life Science Branche

    NASA Astrophysics Data System (ADS)

    Schaff, Peter; Gerbl-Rieger, Susanne; Kloth, Sabine; Schübel, Christian; Daxenberger, Andreas; Engler, Claus

    Life Sciences [1] (Lebenswissenschaften) sind ein globales Innovationsfeld mit Anwendungen der Bio- und Medizinwissenschaften, der Pharma-, Chemie-, Kosmetik- und Lebensmittelindustrie. Diese Branche zeichnet sich durch eine stark interdisziplinäre Ausrichtung aus, mit Anwendung wissenschaftlicher Erkenntnisse und Einsatz von Ausgangsstoffen aus der modernen Biologie, Chemie und Humanmedizin sowie gezielter marktwirtschaftlich orientierter Arbeit.

  9. Astrowissen. Zahlen - Daten - Fakten.

    NASA Astrophysics Data System (ADS)

    Keller, H.-U.

    This book is a completely revised and enlarged version of the 1994 edition (see Abstr. 61.003.081). Contents: Astronomie - die Wissenschaft vom Universum und seinen Sternen. Astronomische Instrumente. Sphärische Astronomie. Grundzüge der Himmelsmechanik. Das Sonnensystem. Stellarastronomie. Doppelsterne und Veränderliche. Sternhaufen und Assoziationen. Das Milchstraßensystem. Galaxien und Kosmologie. Meilensteine der Astronomie.

  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. The sky-disk of Nebra - sun, moon and stars (German Title: Die Himmelsscheibe von Nebra - Sonne, Mond und Sterne)

    NASA Astrophysics Data System (ADS)

    Schlosser, Wolfhard

    No prehistorical find anywhere shows such a clear proof for the interest of prehistoric mankind in cosmic events as does the Nebra sky-disk. With an almost 100 percent probability, the (originally) 32 centimeter-size gold plates represent stars. According to astronomical analysis, the group of seven closely arranged plates represent the Pleiades (The Seven Sisters). Statistical research strengthens the view that the remaining 25 gold plates cannot be assigned to individual constellations, but represent the general starry night sky. Without much restriction, the two lateral arcs (added at a later time) can be assigned to those horizon regions which are accessible to the sun over the year for the geographic latitude of Saxe-Anhalt. A slight asymmetry of these arcs with respect to the center of the disk makes it possible that the upper solar limb was observed. The lower pinnate arc with an interior drawing - also a later addition - can be interpreted as the solar barque, which, because of the above-mentioned asymmetry, indicates the southern direction of the sky-disk. An investigation of the visibilities of the Pleiades for the finding spot of the Mittelberg indicates that only their last evening visibility (March 10 of our calendar) and their first morning setting (October 17) were of calendary use in the early Bronze Age. At these times, the Pleiades were found in those parts of the sky which are the domain of the young crescent shortly after new moon (March) and of the full moon (October). This would make possible a suitable assignment of the sky-disk's crescent- and round object to both these phases of the moon. The said dates describe quite well the beginning and the end of the agricultural year for the region where the sky-disk was found. Such a working hypothesis (‘rural year’) is not at all unique, but is supported by numerous peasant-rules referring to the Pleiades from antiquity up to the present time. In particular, Lithuanian peasants observed until modern times the last evening visibility and the first morning setting of the Pleiades as agricultural key-dates or omina.

  12. Untersuchungen an Plattfischen und Nordseegarnelen (Crangon crangon) im Eulitoral des Wattenmeeres nach dem Übergang zum Bodenleben

    NASA Astrophysics Data System (ADS)

    Berghahn, R.

    1983-06-01

    In spring and early summer, Pleuronectes platessa, Platichthys flesus, Solea solea, and Crangon crangon transform to benthic postlarvae in the shallow water region of the North Frisian Wadden Sea (eastern North Sea). During the first weeks after metamorphosis, they remain in the puddles and drainage gulleys on the tidal flats that are exposed during low tide. Positive rheotaxis prompting the juveniles to swim against the ebb tide currents is an important mechanism for maintaining their position on the flats. When sunlight intensity increases, they continue their locomotory and feeding activity, even during daytime, in the pools still present at low tide. On warm, cloudless days, temperature levels in these pools may increase to lethal thresholds. Consequently, the animals attempt to escape from higher tidal flats near the shore through the drainage gulleys. Such migrations bring about changes in their distribution patterns. Plaice can scarcely be found in near-shore areas, and they are absent at both high and low tide. The responses observed were correlated to physical and chemical data recorded during the observation period. The ecological significance of tidal pools as habitats is discussed.

  13. 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)

  14. GSC 03529-02286, GSC 02008-00283 und GSC 07165-03037 - Drei neue RR-Lyrae-Sterne

    NASA Astrophysics Data System (ADS)

    Bernhard, Klaus; Srdoc, Gregor; Huemmerich, Stefan

    2013-03-01

    During an extended investigation of candidate variable stars from the SuperWASP database (cf. e.g. Bernhard and Srdoc, 2011), three new RR Lyrae stars have been discovered. The following elements have been derived: GSC 03529-02286 (Type RRc): HJD (Max) = 2454327.472 (4) + E* 0.277202 (2) GSC 02008-00283 (Type RRc): HJD (Max) = 2453567.669 (2) + E* 0.349129 (2) GSC 07165-03037 (Type RRab): HJD (Max) = 2453901.869 (2) + E* 0.561553 (2) Klaus Bernhard and Stefan Huemmerich are member of the BAV.

  15. Eigenstandig lernende Schulerinnen und Schuler--Bericht uber ein empirisches Forschungsprojekt = Autonomous Learners--An Empirical Research Project.

    ERIC Educational Resources Information Center

    Beck, Erwin; And Others

    1991-01-01

    Presents results of an experiment enabling students to develop their own cognitive and metacognitive strategies to promote autonomous learning in mathematical problem solving, knowledge acquisition, and written composition. Explains that students dealt with models of teachers' and classmates' cognitive performances and monitored their own…

  16. Das Pinealorgan der Wirbeltiere: ein Modell für Untersuchungen von Rezeptor-und Effektormechanismen in neuronalen Systemen

    NASA Astrophysics Data System (ADS)

    Korf, Horst-W.; Wicht, Helmut

    1991-10-01

    Cell and molecular biological investigations have greatly contributed to our understanding of receptor and effector mechanisms in sensory, neuronal, and endocrine cells. A fascinating aspect of this line of research is how such mechanisms have evolved and how they interact with each other. As shown in this contribution, the vertebrate pineal organ is an interesting model to study these problems, because it undergoes a conspicuous transformation during phylogeny, comprises two well-chraracterized receptor mechanisms (photoreception and adrenoreception), and acts upon its targets via neuronal and neuroendocrine signals.

  17. [Commentary to the paper: immobilising malignant phyllodes tumour of the breast by E. Fritsche, U. Hug und D. Winterholer].

    PubMed

    Horch, R E

    2015-04-01

    The size of a tumor should not be the limiting factor when it comes to the decision for surgical treatment of such entities. Due to modern plastic reconstructive techniques an R0 situaiton should always be attempted, and in the worst case an interdisciplinary palliative resection should be possible and recommendable. As the present case with a tumour that led to immobility clearly indicates, the gain in quality of life undoubtedly is a proof of the necessity and value of the surgical treatment of this entity.

  18. Eventorientierte Veranstaltungen und Lebensqualität innenstädtischer Wohnbevölkerung. Das Beispiel Bamberg

    NASA Astrophysics Data System (ADS)

    Redepenning, Marc; Rhein, Niklas; Sauerwald, David

    2016-09-01

    Events do have, in addition to economic effects, impact on the quality of life of the affected population. Using a case study from the city of Bamberg this article addresses the subjective contentment with larger events. The results show variation in the range of contentment depending on age and time of residency in the city. Furthermore, it becomes obvious that the particular expectation on "life in the inner city" shapes the contentment. Cities should pay attention to this social heterogeneity when deploying strategies of revitalisation through festivals and events. They should take it seriously by using tools of collaborative planning to preserve the multi-functionality of inner cities.

  19. Learning, Adjustment and Stress Disorders: With Special Reference to Tsunami Affected Regions. Beitrage zur Padagogischen und Rehabilitationspsychologie. Volume 1

    ERIC Educational Resources Information Center

    Witruk, Evelin, Ed.; Riha, David, Ed.; Teichert, Alexandra, Ed.; Haase, Norman, Ed.; Stueck, Marcus, Ed.

    2010-01-01

    This book contains selected contributions from the international workshop Learning, "Adjustment and Stress Disorders--with special reference to Tsunami affected Regions" organised by Evelin Witruk and the team of Educational and Rehabilitative Psychology at the University of Leipzig in January 2006. The book contains new results and the…

  20. Experimental und numerical investigations on cooling efficiency of Air-Mist nozzles on steel during continuous casting

    NASA Astrophysics Data System (ADS)

    Arth, G.; Taferner, M.; Bernhard, C.; Michelic, S.

    2016-07-01

    Cooling strategies in continuous casting of steel can vary from rapid cooling to slow cooling, mainly controlled by adjusting the amount of water sprayed onto the surface of the product. Inadequate adjustment however can lead to local surface undercooling or reheating, leading to surface and inner defects. This paper focuses on cooling efficiency of Air-Mist nozzles on casted steel and the experimental and numerical prediction of surface temperature distributions over the product width. The first part explains the determination of heat transfer coefficients (HTC) on laboratory scale, using a so called nozzle measuring stand (NMS). Based on measured water distributions and determined HTC's for air-mist nozzles using the NMS, surface temperatures are calculated by a transient 2D-model on a simple steel plate, explained in the second part of this paper. Simulations are carried out varying water impact density and spray water distribution, consequently influencing the local HTC distribution over the plate width. Furthermore, these results will be interpreted with regard to their consequence for surface and internal quality of the cast product. The results reveal the difficulty of correct adjustment of the amount of sprayed water, concurrent influencing water distribution and thus changing HTC distribution and surface temperature.

  1. Low-rank coal research under the UND/DOE cooperative agreement. Quarterly technical progress report, April 1983-June 1983

    SciTech Connect

    Wiltsee, Jr., G. A.

    1983-01-01

    Progress reports are presented for the following tasks: (1) gasification wastewater treatment and reuse; (2) fine coal cleaning; (3) coal-water slurry preparation; (4) low-rank coal liquefaction; (5) combined flue gas cleanup/simultaneous SO/sub x/-NO/sub x/ control; (6) particulate control and hydrocarbons and trace element emissions from low-rank coals; (7) waste characterization; (8) combustion research and ash fowling; (9) fluidized-bed combustion of low-rank coals; (10) ash and slag characterization; (11) organic structure of coal; (12) distribution of inorganics in low-rank coals; (13) physical properties and moisture of low-rank coals; (14) supercritical solvent extraction; and (15) pyrolysis and devolatilization.

  2. 75 FR 12466 - Airworthiness Directives; GROB-WERKE (Type Certificate Previously Held by BURKHART GROB Luft- und...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-16

    ... failed canopy jettison test, during a regular maintenance check. The investigation revealed that a cable shroud of the jettison system protruded the canopy structure, which probably caused the malfunction. Inability to jettison the canopy in flight would prevent evacuation of the aeroplane in case of need....

  3. 75 FR 31734 - Airworthiness Directives; GROB-WERKE (Type Certificate Previously Held by BURKHART GROB Luft- und...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-04

    ... manufacturer has received a report of a failed canopy jettison test, during a regular maintenance check. The investigation revealed that a cable shroud of the jettison system protruded the canopy structure, which probably caused the malfunction. Inability to jettison the canopy in flight would prevent evacuation of...

  4. 75 FR 59077 - Airworthiness Directives; GROB-WERKE (Type Certificate Previously Held by BURKHART GROB Luft- und...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-27

    ... describes the unsafe condition as: The manufacturer has received a report of a failed canopy jettison test... protruded the canopy structure, which probably caused the malfunction. Inability to jettison the canopy in... for the specified products. The MCAI states: The manufacturer has received a report of a failed...

  5. Auf gute Nachbarschaft!. Verantwortungsübernahme durch Unternehmen für die Stadtteilentwicklung - Haniel und Grillo in Duisburg

    NASA Astrophysics Data System (ADS)

    Kleine-König, Christiane; Hohn, Uta

    2016-03-01

    Companies' community involvement turns out to be spatially relevant and-in many cases-to be focused on the near surroundings of the place of business. Some companies strategically align their involvement in order to systematically address local challenges. The essay at hand addresses the subject of corporate social responsibility from a local development perspective. Using the example of two family-owned enterprises based in Duisburg, Haniel and Grillo, it illustrates how socially committed companies can get involved with their local community by acting as good neighbours. Furthermore, it argues that socially committed companies can function as producers of space concerning matters of urban and local development. The specific local settings as well as the economic conditions of the local community serve as an explanatory background of the companies' involvement. The cases presented in this paper prove the firms' specific knowledge of local development needs and possibilities. This makes them qualified partners for local government actors and civil society actors. Thus, in the future, it is worth addressing corporate local responsibility from a governance point of view both in theory and in practice.

  6. 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.

  7. Zum Ausgleich von generativer und energetischer Sprachbetrachtung (A Comparison of the "Generative" and "Energetic" Views of Language)

    ERIC Educational Resources Information Center

    Weisgerber, Leo

    1972-01-01

    Discussion of two basic conceptions: Wilhelm von Humboldt's idea of language as energeia'' existing within and without man, and Noam Chomsky's idea of language generated by the speaker according to an innate apparatus. Revised version of lectures presented at the University of Bonn, West Germany in August 1971. (RS)

  8. Untersuchungen ueber die Kultivierung und Biologie von Trichomonas vaginalis (Investigation on Cultivation and Biology of Trichomonas vaginalis),

    DTIC Science & Technology

    Since long possible cyst formation by Trichomonas vaginalis has been discussed. According to our observations the round forms of Trichomonas ... vaginalis in relation to its biogenic surroundings. Here the biochemico-physiological relationship between Trichomonas and the fundamental biogenic...generally appear as degenerative manifestations of the cell, especially in older cultures. We tried to study analytically the biology of Trichomonas

  9. Die berufliche Weiterbildung von Grund- und Sekundarschullehrern in Japan (Further Professional Training for Elementary and Secondary School Teachers in Japan).

    ERIC Educational Resources Information Center

    Shimahara, N. Ken

    2001-01-01

    Focuses on the system of further vocational education for Japanese teachers that is based on a network of cooperation among colleagues. Demonstrates how the Japanese conception of teaching as a craft determines the professional career of teachers within elementary and secondary schooling. (CMK)

  10. Das Konstanzer Trainingsmodell (KTM) - Grundlagen und neue Entwicklungen (The Konstanz Training Model (KTM) -- Fundamental Principles and Recent Developments).

    ERIC Educational Resources Information Center

    Dann, Hanns-Dietrich; Humpert, Winfried

    2002-01-01

    Summarizes the Konstanz Training Model (KTM), a German primary and secondary preventive program that increases teacher self-competence and social competence in dealing with aggressive and disruptive student behaviors. Emphasizes KTM's focus on systemic aspects, cognitive level, and behavioral level approaches. Describes KTM Compact, a short term…

  11. Moglichkeiten und Grenzen eines evolutionaren Paradigmas in der Erziehungswissenschaft (Possibilities and Limits of an Evolutionary Paradigm in Educational Science).

    ERIC Educational Resources Information Center

    Nipkow, Karl Ernst

    2002-01-01

    Describes a sectoral and paradigmatic approach to evolutionary research. Argues that an evolutionary paradigm does not exist. Examines the socio-biological approach and that of a system-theoretical oriented general evolutionary theory. Utilizes the topics of cooperation, delimitation, and indoctrination to explain more promising ways of adoption.…

  12. Review of the development of small- and medium-capacity gas turbines at the Motoren- und Turbinen Union

    NASA Technical Reports Server (NTRS)

    Heilmann, W.

    1985-01-01

    Small- and medium-capacity gas turbines under development for turboprop aircraft and helicopter, as well as for armored and commercial vehicle propulsion, are discussed. Design problems related to axial turbines, ceramic components, regenerative gas turbines, and the optimal expansion ratios for turbines with capacities from 250 to greater than 800 kW are considered; in addition, combustion chamber technology is mentioned. Prototype gas turbines with capacities of 500 to 600 kW or 800 to 1800 kW are described.

  13. Ausbreitung und Vermischung geogener, kohlendioxidführender Thermalsole in oberflächennahem Grundwasser, Bad Nauheim

    NASA Astrophysics Data System (ADS)

    Schäffer, Rafael; Sass, Ingo

    2016-11-01

    Anomalous high temperatures, salt contents and carbon dioxide concentrations were detected in shallow groundwater in the famous Art Deco ensemble, Sprudelhof. A carbon dioxide lifted thermal brine is discharged by ancient wells down to 180 m deep. Since 1856, the well installation had been operated without any changes and a low level of maintenance. During the last centuries, however, numerous anthropogenic interventions in the Sprudelhof's underground led to changes of the natural brine system, as well as mixing, dilution and expansion processes in the near-surface aquifers. Recently, the thermal brine has been escaping from the well bore by uncontrolled means, contaminating the shallow underground. Corrosion of the casings has allowed the natural mixing system to reactivate. A groundwater monitoring network containing Duo-wells, allows independent samplings of the liquid and gaseous phases. Coinciding brine-groundwater mixing ratios were calculated for the two uppermost aquifers, as well as a gradient for increasing electric conductivities with depth.

  14. Kognitive Struktur Und Lernsequenz Nr. 1. (Cognitive Structure and Sequence of Information Acquisition. Research Bulletin No. 1.)

    ERIC Educational Resources Information Center

    Flammer, August

    In experiments on individual differences in learning, knowledge prerequisites and learning strategies have been shown to be important factors. The author questions whether learning optimization should rely on direct measures from outside the learner or should elucidate and strengthen the individual's capacity for learning decisions. He proposes to…

  15. Lagerungsabhängige Durchlässigkeit von Kies-/Sand- und Glaskugelfilterschüttungen

    NASA Astrophysics Data System (ADS)

    Nillert, Peter; Bachmann, Andreas; Nillert, David

    2015-06-01

    The hydraulic conductivity of loose and dense samples of commercially available filter grain material from natural gravels and sands has been estimated from permeameter test results and using the formula of Fair & Hatch (Jour. Amer. Water Works Assoc. 25:1551-1565, 1933). Sand and gravel with grain sizes of 0.4-9 mm and glass beads for water filters with particle sizes from 0.25 to 10 mm were examined. The formula is based on a sum calculated from the grain size analysis of the filter grain and its packing density, characterized by the porosity or void ratio specified for these materials.

  16. PHREASIM - Ein Expertensystem zur Simulation von Fließverhältnissen in Grundwassermessstellen und deren unmittelbarem Nahfeld

    NASA Astrophysics Data System (ADS)

    Drießen, Joachim; Schöttler, Marc; Enzmann, Frieder; Lakdawala, Zahra; Steiner, Konrad; Popov, Peter; Iliev, Oleg; Drews, Michael; Wieber, Georg; Kersten, Michael

    2015-09-01

    In this study, a new numerical solver based on a coupling of the Navier-Stokes and Brinkman equations is presented. The solver can model 3D horizontal steady-state flow conditions with interactions between the aquifer, gravel-pack, well screen, and open borehole at the interface between the borehole and the surrounding porous filter and aquifer, thus solving the critical transition from porous to free flow. The solver is embedded in the workflow of the PHREASIM expert system. It allows for designing a broad variety of well designs and flow scenarios while considering the permeabilities and geometries of the involved microstructures. Stationary flow scenarios can be visualized in any cross-section and at any discrete point within the model. In order to verify the validity of the numerical approach, a variety of flow scenarios were investigated in sand tank model experiments and simulated with PHREASIM. By comparing the results of both simulations and experimental measurements performed using identical boundary conditions, PHREASIM proved to be viable for accurately replicating virtually steady-state flow conditions. PHREASIM aims to support the interpretation and significance of flow data gained by borehole flow measuring systems like PHREALOG.

  17. Störungen des Betriebs geothermischer Anlagen durch mikrobielle Stoffwechselprozesse und Erfolg von Gegenmaßnahmen

    NASA Astrophysics Data System (ADS)

    Würdemann, Hilke; Westphal, Anke; Kleyböcker, Anne; Miethling-Graff, Rona; Teitz, Sebastian; Kasina, Monika; Seibt, Andrea; Wolfgramm, Markus; Eichinger, Florian; Lerm, Stephanie

    2016-06-01

    In the context of geothermal systems, biofilms can influence mineral formation and material resistance against corrosion. In three geothermal plants with different salinity and temperature, organisms of the sulfur cycle have contributed to process failures. On the cold side of a heat store, the increased diversity and abundance of sulfate reducing bacteria (SRB) revealed their participation in corrosion processes and their contribution to a decline in injection efficiency. In all plants, a temporary ingress of oxygen or nitrate led to an increased abundance of sulfur oxidizing bacteria (SOB) that might have accelerated corrosion. In addition, the increase in SOB abundance led to filter clogging in a cold store. Based on their role in microbial-induced corrosion (MIC), changes in the abundance of SOB and SRB may indicate the cause of failure. Measures to control microbial growth, mineral deposits and corrosion, such as temporary increases in temperature, acidification, and addition of hydrogen peroxide (H2O2) and nitrate, were evaluated.

  18. Der Koch und seine Rezepte. ZE-Diskussion. Pattern Drill (The Cook and his Recipes. ZE Discussion. Pattern Drill)

    ERIC Educational Resources Information Center

    Raasch, Albert

    1976-01-01

    Shows, with examples of application, how pattern drills can be varied to fit various levels of difficulty. Variations in exercise technique according to the difficulty level can be realized quantitatively by changes in the stimulus and/or response, and qualitatively by variation of material (vocabulary and structures). (Text is in German.)…

  19. In the footsteps of astronomers in Bremen and Lilienthal. (German Title: Auf den Spuren von Astronomen in Bremen und Lilienthal)

    NASA Astrophysics Data System (ADS)

    Langkavel, Arno

    When Bremen and Lilienthal are mentioned, people interested in the history of astronomy will first of all remember Wilhelm Olbers (1785-1840) and Johann Hieronymus Schroeter (1745-1816). In addition to them, Friedrich Wilhelm Bessel (1784-1846) and Carl Friedrich Gauß (1777-1855) have also left their traces. Two walks describe the main memorial sites, which are all outdoors and easily accessible to the general public.

  20. Johann Gottlieb Schrader and the construction of telescopes in Lilienthal. (German Title: Johann Gottlieb Schrader und der Lilienthaler Fernrohrbau)

    NASA Astrophysics Data System (ADS)

    Leue, Hans-Joachim

    More than 200 years ago, the first large reflectors on the European continent were built at Johann Hieronymus Schroeter's observatory in Lilienthal near Bremen. Johann Gottlieb Friedrich Schrader, professor of physics and chemistry at Kiel University, developed a white reflecting metal alloy during his 10-month stay with Schroeter, and used it for the production of numerous telescope mirrors. The period of telescope making at Lilienthal started with Schrader. This paper describes the cooperation of the two astronomers and reports about the results of an optical and chemical analysis of three Herschel telescope mirrors.