Gamma Rays from N15(p, αγ)C12 and N15(p, γ)O16

A new resonance in the reaction N15(p, αγ)C12 giving the 4.43-Mev γ ray from the first excited state of C12 has been found at a proton energy of 1.64±0.03 Mev. The angular distribution of the γ rays indicates that the resonant state in the compound nucleus O16 at an excitation energy of 13.65 Mev has spin and parity equal to 1+ or 2-. The resonance at 1.05-Mev proton energy has been reinvestigated. At this resonance the capture γ rays from the reaction N15(p, γ)O16 are found to be isotropic, which indicates that this 13.09-Mev level of O16 has spin equal to 1. A search was made for capture γ rays at the 0.340-Mev resonance of N15(p, α)C12 but there were less than 1 percent of the number at the 1.05-Mev resonance. Therefore, it seems that these two levels do not have identical spin, parity, and isotopic spin values

Neutrons and Gamma Rays from the Alpha-Particle Bombardment of Be9, B10, B11, C13, and O18

Excitation curves at 0° and 90° were studied for neutrons and γ rays produced in bombardment of thin targets of Be9, B10, B11, C13, and O18 by α particles with energies of from 1.8 to 5.3 Mev. Resonances were observed in the Be9(α, n)C12 reaction at bombarding energies of 1.9, 2.3, 2.6, 3.98, 4.4, and 5.0 Mev. The C13(α, n)O16 reaction showed resonances at 2.09, 2.25, 2.42, 2.605, 2.69, 2.775, 2.825, 3.09, 3.33, 3.42, 3.67, 3.73, 4.125, 4.42, 4.50, 4.63, 4.75, and 5.05 Mev. The B10(α, n)N13 excitation curve has resonances at 2.16, 2.25, 2.90, 4.53, 4.85, and 5.36 Mev, while the γ-ray yield from the B10(α, pγ)C13 reaction showed all these as well as resonances at 3.6 and 3.95 Mev. The B11(α, n)C13 reaction has resonances at bombarding energies of 2.06, 2.60, 2.93, 2.97, 3.23, 3.54, 3.72, 3.92, 4.25, 4.34, and 5.00 Mev. The O18(α, n)Ne21 reaction was studied with a thicker target (90-130 kev). Resonances in the neutron yield were resolved at 2.21, 2.47, 2.57, 2.72, 2.94, 3.24, 3.63, 3.91, 4.12, 4.22, 4.33, 4.52, and 4.82 Mev. Cross sections and widths of the resonances in the various reactions were determined

Cross Section and Angular Distributions of the (d, p) and (d, n) Reactions in C12 from 1.8 to 6.1 Mev

The reaction C12(d, p)C13 has been studied from a deuteron bombarding energy of 1.8 to 6.1 Mev. Resonances were found at 2.47, 2.67, 2.99, 3.39, 4.00, 4.6, 4.8, 5.34, and 5.64 Mev. Angular distributions of protons leaving C13 in the ground state show a pronounced Butler peak at 25° over the entire deuteron energy range. The angular distributions can be explained by assuming small amplitudes for compound nucleus formation interfering with large stripping amplitudes. Angular distributions of the lower energy group of protons leaving C13 excited to 3.09 Mev show a pronounced Butler peak at 0° and an even smaller contribution of compound nucleus formation. The reaction C12(d, n)N13 was also studied, and showed similar resonances and angular distributions. An analysis is made of the phase difference between the resonant and nonresonant parts of the cross section for the (d, p) reaction near the resonance at 4.00 Mev

Angular distribution of gamma-rays and short-range alpha-particles from N15(p,αγ)C12

Measurements of the angular distributions of gamma-rays and alpha-particles from the reaction N15(p,αγ)C12 indicate that the 4.432-Mev excited state of C12 is 2+ or >4, that the 12.51-Mev level of O16 is 2- or >5, that the 12.95-Mev level is 2- or >5, and that the 13.24-Mev level is 4+ or >5

Festschrift anläßlich der Emeritierung von Prof. Dr.-Ing. Walter Raab

Festschrift zum Festkolloquium am 8. April 1994 anläßlich der Emeritierung von Herrn Prof. Dr.-Ing. Walter Raab, Leiter des Fachgebiets Maschinenlemente und Mechanik an der Technischen Hochschule Darmstadt

Ancient xenocrystic zircon in young volcanic rocks of the southern Lesser Antilles island arc

The Lesser Antilles arc is one of the best global examples in which to examine the effects of the involvement of subducted sediment and crustal assimilation in the generation of arc crust. Most of the zircon recovered in our study of igneous and volcaniclastic rocks from Grenada and Carriacou (part of the Grenadines chain) is younger than 2 Ma. Within some late Paleogene to Neogene (~ 34–0.2 Ma) lavas and volcaniclastic sediments however, there are Paleozoic to Paleoarchean (~ 250–3469 Ma) xenocrysts, and Late Jurassic to Precambrian zircon (~ 158–2667 Ma) are found in beach and river sands. The trace element characteristics of zircon clearly differentiate between different types of magmas generated in the southern Lesser Antilles through time. The zircon population from the younger arc (Miocene, ~ 22–19 Ma, to Present) has minor negative Eu anomalies, well-defined positive Ce anomalies, and a marked enrichment in heavy rare earth elements (HREE), consistent with crystallization from very oxidized magmas in which Eu2 + was in low abundance. In contrast, zircon from the older arc (Eocene to mid-Oligocene, ~ 30–28 Ma) has two different REE patterns: 1) slight enrichment in the light (L)REE, small to absent Ce anomalies, and negative Eu anomalies and 2) enriched High (H)REE, positive Ce anomalies and negative Eu anomalies (a similar pattern is observed in the xenocrystic zircon population). The combination of positive Ce and negative Eu anomalies in the zircon population of the older arc indicates crystallization from magmas that were variably, but considerably less oxidized than those of the younger arc. All the igneous zircon has positive εHf(t), reflecting derivation from a predominantly juvenile mantle source. However, the εHf(t) values vary significantly within samples, reflecting considerable Hf isotopic heterogeneity in the source. The presence of xenocrystic zircon in the southern Lesser Antilles is evidence for the assimilation of intra-arc crustal sediments and/or the recycling and incorporation of sediments into the magma sources in the mantle wedge. Most likely however, primitive magmas stalling and fractionating during their ascent through the Antilles crust entrained ancient zircon. This is evidence by the geochemistry of the study samples, which is inconsistent with any involvement of partially melted subducted sediment. Paleogeographic reconstructions show that the old zircon could derive from distant regions such as the Eastern Andean Cordillera of Colombia, the Merida Andes, and the northern Venezuela coastal ranges, transported for example by the Proto-Maracaibo River precursor of the Orinoco River.This study was supported by Deutsche Forschungsgemeinschaft (DFG) grants KR590/85-1 to AK and RO4174/2-1 to YRA, and Spanish MINECO grants CGL2015-65824 and CGL2012-36263 and University of Granada research program (CIC) to AGC and CLC. This research also received support from the SYNTHESYS Project (http://www.synthesys.info/) which is financed by the European Community Research Infrastructure Action under the FP7 “Capacities” Program, the Intra-University Research Support Program of Mainz University (Universitätsinterne Forschungsförderung (FoFö)

Beiträge zur Geschichte des Landkreises Regensburg 37

Heimat gestern und heute III - 56 Arbeitsproben von 12 Autoren; darin: Detterbeck, Pius: Mei Häuserl, mei Goat´n (S. 3); Fendl, Josef, Herbst im Jura (bei Schönhofen), Die Jahreszeit der fünf Sinne, Terra incognita, Schlecht verteilt, Diplomatisch (S. 4-5); Heigl, Margot: Hoamat, Grod a Hausfrau, Liebeserklärung, "Bayernbild", "Blaue" Volksmusik, Glück, Zeit, Kloana Unterschied (S. 6-8); Hemrich, Hans: Dö staade Zeit, Abschied, olt (S. 9-10); Kraus, Josef: A Pferdl, Nie Altwerden, Die alt Mauer, Scho wieder (S. 11-16); Mühldorfer, Albert: Koa Arbat, Mia samma aa wea, Wöiltbürger, Sanierung, Landschaftsplanung, Versaamt is versaamt, Rest-WAA-heit (S. 17-18); Rosenmeier, Maria: Fortschritt, Oasn, Schauspieler, Menschn, Moral, Generationsproblem, Glockenklang, Walhalla - Ruhmestempel (S. 19-20); Seitz, Angelika: Regensburg, August 85, wintergedeck, spätaugust, i bin unschuldig, im Normalfall (S. 21-23); Stadler, Ali: Gestern war´s, Woaßt as no? (S. 24-25); Staudigl, Franz Xaver: Beratzhausener Skizzen, Friedhof, Ansichtskarte "Partie am Marktplatz", Allegorie? (S. 26-27); Weigert, Hans: Macha, Da Duillnbock (S. 28-30); Zenger, Georg: Blick ins Allerseelenland (S. 31

Hautkrankheiten

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