High Current Diffusion Type Diodes at Cryogenic Temperatures for the LHC Superconducting Magnet Protection

High-current by-pass diodes are required for the protection of the superconducting magnets for the Large Hadron Collider LHC at CERN . These diodes are at liquid helium tem-perature and will be exposed to irradiation. With the re-location of the by-pass diodes for the main dipoles underneath the iron yoke and of those for the quadrupoles at the bottom of the cryostat the new estimations for the irradiation dose amounts to about 30 Gy and a neutron fluence of about 1.5 x 1011 n/cm2 for the dipole di-odes and about 100 Gy and5 x 1011 n/cm2 for the quadrupole diodes during 10 years. These relatively low doses may allow the use of diffusion type diodes in-stead of epitaxial diodes. The electrical characteristics of several diodes were measured at temperatures in the range between 1.8K and 300K. Diffu-sion type diodes from three manufacturers were submitted to high current endurance tests in liquid helium. Electrical characteristics and temperatures were measured versus time and showed acceptable results. First irradiation tests show that modified diffusion diodes can be used at least for the dipole by-pass

Identification of chromosomes involved in a Robertsonian translocation in cattle

Summary- The chromosomes involved in the robertsonian translocation described after classical Giemsa staining by Darre et al. (1974), were determined using G(GTG), R(RBA) and C(CBG) banding techniques. The chromosomes in question were identified as chromosomes 9 and 23. cattle- chromosome- robertsonian translocation Résumé- Les chromosomes impliqués dans une translocation robertsonienne décrite, tout d’abord, en coloration conventionnelle par Darre et al. (1974) ont été déterminés à l’aide des techniques de marquage G(GTG), R(RBA) et C(CBG). sont le 9 et le 23. boeuf- chromosome- translocation robertsonienne Les chromosomes concerné

Cytogenetic investigation in Saanen and Alpine artificial insemination bucks. Identification of a Robertsonian translocation

The cytogenetic study of 224 AI Saanen and Alpine he-goats revealed the presence of a Saanen animal carrying a Robertsonian translocation. The chromosomes involved in this translocation were determined using G (GTG) and C (CBG) banding techniques. The chromosomes in question were identified as chromosomes 6 and 15.L’étude cytogénétique de 224 boucs d’insémination artificielle de races Saanen et Alpine a permis de mettre en évidence la présence d’un animal de race Saanen porteur d’une translocation robertsonienne. Les chromosomes impliqués dans cette translocation ont été déterminés à l’aide des techniques de marquage G (GTG) et C (CBG). Les chromosomes concernés sont le 6 et le 15

van der Waals density functionals built upon the electron-gas tradition: Facing the challenge of competing interactions

The theoretical description of sparse matter attracts much interest, in particular for those ground-state properties that can be described by density functional theory (DFT). One proposed approach, the van der Waals density functional (vdW-DF) method, rests on strong physical foundations and offers simple yet accurate and robust functionals. A very recent functional within this method called vdW-DF-cx [K. Berland and P. Hyldgaard, Phys. Rev. B 89, 035412] stands out in its attempt to use an exchange energy derived from the same plasmon-based theory from which the nonlocal correlation energy was derived. Encouraged by its good performance for solids, layered materials, and aromatic molecules, we apply it to several systems that are characterized by competing interactions. These include the ferroelectric response in PbTiO$_3$, the adsorption of small molecules within metal-organic frameworks (MOFs), the graphite/diamond phase transition, and the adsorption of an aromatic-molecule on the Ag(111) surface. Our results indicate that vdW-DF-cx is overall well suited to tackle these challenging systems. In addition to being a competitive density functional for sparse matter, the vdW-DF-cx construction presents a more robust general purpose functional that could be applied to a range of materials problems with a variety of competing interactions