Proton $\beta% decay in large magnetic fields

A delicate interplay between the anomalous magnetic moments of the proton and neutron makes, in magnetic fields $B\ge 2\times 10^{14}$ T, the neutron stable and for fields $B\ge 5\times 10^{14}$ T the proton becomes unstable to a decay into a neutron via $\beta$ emission. Limits on the field strengths for which these arguments hold are presented and are related to questions of vacuum stability in the presence of such fields. Possible astrophysical consequences are discussed.Comment: 12 page

A Bethe-Salpeter model for light mesons: spectra and decays

The spectra and electroweak decay properties of light mesons are analyzed within the framework of the instantaneous Bethe-Salpeter equation. The interaction kernel comprises alternative spin-structures for a parameterization of confinement and a residual quark-antiquark interaction based on instanton effects. It is shown that only with a vector confinement the parameters can be chosen such as to yield an excellent description of the light pseudoscalar and vector mesons including weak and two photon decays. However it is found that it is not possible to reconcile this with the Regge behavior of higher lying meson states with the same parameter set.Comment: 12 pages, RevTeX, TK-93-1

Pressure and linear heat capacity in the superconducting state of thoriated UBe13

Even well below Tc, the heavy-fermion superconductor (U,Th)Be13 has a large linear term in its specific heat. We show that under uniaxial pressure, the linear heat capacity increases in magnitude by more than a factor of two. The change is reversible and suggests that the linear term is an intrinsic property of the material. In addition, we find no evidence of hysteresis or of latent heat in the low-temperature and low-pressure portion of the phase diagram, showing that all transitions in this region are second order.Comment: 5 pages, 4 figure

VUURSTEENVINDPLAATSEN; SPOREN VAN JAGER-VERZAMELAARS EN VROEGE LANDBOUWERS IN HET NOORD-NEDERLANDSE LANDSCHAP

The archaeological record of Palaeolithic and Mesolithic sites in the northern Netherlands con­sists mainly of surface collections of flint and stone artefacts. Only relatively few sites have been extensively exeavaled and analyzed. The quality of the remaining thousands of sites is rapidly deteriorating and urgent action is needed. Recently the project \u27Vuursteenvindplaatsen; spo­ren van jager-verzamelaars en vroege land­bouwers in het Noord-Nederlandse landschap\u27 was initiated by the Groningen Jnstitute of Ar­chaeology. The main aim of the project is to assess the state of p reservation of Stone Age re­mains in the northern Netherlands. One major as­pect of the project is to explore the potential of \u27wet sites\u27 in the northern Netherlands

Muntvondsten in scheepswrakken

Met lit. opg. en catalogus

Modderwerk : het uitdiepen van de haven van Amsterdam in de tweede helft van de zeventiende eeuw

Met lit. opg. en verkl. woordenlijst

VELDWERK IN DE VLAKTE VAN ANTIOCHIË

The genesis of the former Amuq lake (Hatay, southern Turkey) is not fully known. A theory is that felling of forest since the Neolithic or Bronze Age led to aggradation of sediment along the banks af the Orontes, which gradually restricted drainage. There was also a general increase in the level af floods and together these two factors led to the development of the lake. The low, but large site Tell al-Hijar is si­tuated within the main body af the former lake. The site had been occupied since the Bronze Age, the final occupation being of Early lslamic date. The latter suggests that the lake did not attain its maximum extent until after the 8th/19th centuries AD. 14C datings and detailed knowledge of the vegetation history might help to answer the question when and how the lake evolved. There­fore corings for palynological research have been carried out in the former lake and in some lakes (Aygzir Gölü, Gölbaşi Gölü) near the Tur­kish-Syrian border