A Cryogenic Test Station for the Pre-series 2400 W @ 1.8 K Refrigeration Units for the LHC

The cooling capacity below 2 K for the superconducting magnets in the Large Hadron Collider (LHC), at CERN, will be provided by eight refrigeration units at 1.8 K, each of them coupled to a 4.5 K refrigerator. The supply of the series units is linked to successful testing and acceptance of the pre-series delivered by the two selected vendors. To properly assess the performance of specific components such as cold compressors and some process specificities a dedicated test station is necessary. The test station is able to process up to 130 g/s between 4.5 & 20 K and aims at simulating the steady and transient operational modes foreseen for the LHC. After recalling the basic characteristics of the 1.8 K refrigeration units and the content of the acceptance tests of the pre-series, the principle of the test cryostat is detailed. The components of the test station and corresponding layout are described. The first testing experience is presented as well as preliminary results of the pre-series units

Cryogenic R&D at the CERN Central Cryogenic Laboratory

The Central Cryogenic Laboratory operates since many years at CERN in the framework of cryogenic R&D for accelerators and experiments. The laboratory hosts several experimental posts for small cryogen ic tests, all implemented with pumping facility for GHe and vacuum, and is equipped with a He liquefier producing 6.105 l/year, which is distributed in dewars. Tests include thermomechanical qualifica tion of structural materials, cryogenic and vacuum qualification of prototypes, evaluation of thermal losses of components. Some of the most relevant results obtained at the laboratory in the last yea rs are outlined in this paper

Comparison of floating and thermalized multilayer insulation systems at low boundary temperature

The Large Hadron Collider (LHC) is 26.7 km circumference particle collider using high-field superconducting magnets operating in superfluid helium. An efficient and robust thermal insulation system is therefore required to minimize the residual heat in leak to the large surface area at 1.9 K constituted by the stainless steel wall of the helium enclosure. The baseline solution uses "floating" multilayer reflective insulation. Moreover, an alternative consists of a combination of multilayer reflective films and a soft screen, partially thermalized to the 5 K level and supported away from the cold wall by net-type insulating spacers. This chapter establishes the improvement potential of the alternative over the baseline solution, and compares their insulation performance on the basis of measured characteristics of thermal contacts and spacers

Cryogenic Facilities at 1.9 K for the Reception of the Superconducting Wires and Cables of the LHC Dipoles Magnets

CERN's LHC project has moved to an implementation phase. The fabrication of 1600 high-field superconducting magnets operating at 1.9 K will require about 6400 km of Nb-Ti cables. A cryogenic test facility has therefore been set up in order, on the one hand, to verify the quality of individual wires and, on the other hand, to control the critical current of the assembled cables. The facility is composed of a helium liquefier, a transfer line, a dewar and pumps. The paper describes the fully automatic operation of this installation and the different test cycles applied to these wires and cables

New cryogenic facilities for testing superconducting equipments for the CERN Large Hadron Collider

CERN's major project, the Large Hadron Collider (LHC), has moved to an implementation phase with machine construction to be completed by 2005. To achieve the design proton-proton centre of mass energy of 14 TeV in the given 27 km circumference LEP tunnel, the LHC will make an extensive use of high-field superconducting magnets using Nb-Ti filament operated at 1.9 K. In order to test, on the one han d, the superconducting cables of the magnets and, on the other hand, the expected performance of several of these magnets assembled in a string representing the lattice period of the machine (107 m lo ng), CERN has installed new cryogenic test facilities. The paper briefly describes these new facilities with all their associated equipments

Testicular fine needle aspiration as a diagnostic tool in non-obstructive azoospermia

n/

Design of the second series 15 m LHC prototype dipole magnet cryostats

A first series of six LHC 10 m long prototype dipole magnets and cryostats have been manufactured in European Industry and the assembled cryo-magnets tested singly and connected in series in a test string at CERN between March 1994 and December 1996. During the same period, an evolution in the requirements for LHC cryogenics distribution has lead the project management to adopt a separate cryo-distribution line running parallel to the LHC machine1. The former standard LHC half-cell, made up of a short straight section unit and four 10 m dipoles, has been discarded and replaced with one composed of a short straight section unit and three 15 m dipoles. The new 15 m LHC dipole magnet cryostats are described. These units house the dipole magnet cold mass standing on three low heat in-leak support columns, and enclosed within an actively cooled radiation screen operating at 4.5-20 K and an actively cooled thermal shield operating at 50-75 K

VALIDITY OF THE INSTRUMENT interRAI EMERGENCY SCREENER FOR PSYCHIATRY FOR THE BRAZILIAN CONTEXT

Objective: The aim of this study was to carry out the translation and present the evidence of validity of the Brazilian version of the interRAI Emergency Screener for Psychiatry (ESP). Method: this is a cross-sectional study conducted in a municipal hospital in the metropolitan region of Porto Alegre, Rio Grande do Sul. A total of 161 patients were evaluated in the first 24 hours of emergency arrival using ESP. Exploratory factor analyses of the sections of the instrument and reliability analyses were conducted using Cronbach's alpha and McDonald's Omega. Results: the analyses suggested an appropriate structure to the purpose of the instrument, two sections containing two factors instead of the expected one-dimensional structure. However, sections with two factors have interpretability and theoretical consistency. The factors presented internal consistency. Conclusion: the Brazilian version of the interRAI Emergency Screener for Psychiatry (ESP) demonstrates adequate psychometric properties through the internal structure of the instrument. Future studies should investigate the relationship of the scores produced by the instrument with clinical diagnosis and with covariates relevant to mental health outcomes.Objetivo: El objetivo de este estudio era realizar la traducción y presentar la evidencia de validez del examinador de emergencia interRAI para psiquiatría (ESP). Método: se trata de una encuesta transversal realizada en un hospital municipal de la región metropolitana de Porto Alegre, Rio Grande do Sul. Un total de 161 pacientes fueron evaluados en las primeras 24 horas de llegada de emergencia utilizando ESP. Los análisis exploratorios de factores de las secciones del instrumento y los análisis de fiabilidad se llevaron a cabo utilizando Cronbach's alpha y McDonald's Omega. Resultados: los análisis sugirieron una estructura adecuada a los propósitos del instrumento, dos secciones que contienen dos factores en lugar de la estructura unidimensional esperada. Sin embargo, las secciones con dos factores tienen interpretabilidad y consistencia teórica. Los factores presentaron consistencia interna. Conclusión: la versión brasileña del Examinador de Emergencia InterRAI para Psiquiatría (ESP) demuestra propiedades psicométricas adecuadas a través de la estructura interna del instrumento. Los estudios futuros deben investigar la relación de las puntuaciones producidas por el instrumento con el diagnóstico clínico y con covariables relevantes para los resultados de salud mental.Objetivo: O objetivo do estudo foi realizar a tradução e apresentar as evidências de validade do interRAI Emergency Screener for Psychiatry (ESP). Método: trata-se de uma pesquisa transversal realizada em um hospital municipal da região metropolitana de Porto Alegre, Rio Grande do Sul. Foram avaliados 161 pacientes nas primeiras 24 hs da chegada a emergência utilizando o ESP. Foram conduzidas análises fatoriais exploratórias das seções do instrumento e análises de fidedignidade por meio do alfa de Cronbach e Ômega de McDonald. Resultados: as análises sugeriram uma estrutura adequada ao propósito do instrumento, sendo duas seções contendo dois fatores ao invés da estrutura unidimensional esperada. Contudo, as seções com dois fatores possuem interpretabilidade e consistência teórica. Os fatores apresentaram consistência interna. Conclusão: a versão brasileira do interRAI Emergency Screener for Psychiatry (ESP) demonstra adequadas propriedades psicométricas por meio da estrutura interna do instrumento. Estudos futuros deverão investigar a relação dos escores produzidos pelo instrumento com diagnóstico clínico e com covariáveis relevantes para os desfechos de saúde mental

Relationship between solid state structure and solution stability of copper(ii)-hydroxypyridinecarboxylate complexes

The complementary solid state/solution studies of the systematic series of bioactive ligands 3-hydroxy- 1-methyl-4-pyridinecarboxylate (L1), 3-hydroxy-1,2,6-trimethyl-4-pyridinecarboxylate (L2), 4-hydroxy-1- methyl-3-pyridinecarboxylate (L3), 4-hydroxy-1,6-dimethyl-3-pyridinecarboxylate (L4), 4-hydroxy-1-(2- hydroxyethyl)-6-methyl-3-pyridinecarboxylate (L5) and 4-hydroxy-1-(2-carboxyethyl)-6-methyl-3- pyridinecarboxylate (L6) with copper(II) have been performed in order to design efficient chelating drugs for the treatment of metal overloading conditions. Single crystals of [Cu(L1)2(H2O)]3H2O (1) (monomer) with axial water coordination, [Cu2(L2)4]6H2O (2) and [Cu2(L3)4]4H2O (3) (cyclic dimers), where pyridinolato and carboxylato oxygens, respectively, act as linkers between adjacent copper complexes, [Cu(L4)2]n3H2O (4) (1D polymer) and [Cu3(L5)6]18H2O (5) (trimer), constructed using two square-pyramidal and one elongated octahedral Cu(II) complexes have been determined by SXRD. The bidentate coordination mode of the ligands has been found preferentially with cis arrangements in 1 and 2 and trans arrangements in 3\u20135. The solution speciation and complex stability of aqueous solutions have been studied by pH-dependent electron paramagnetic resonance spectroscopy resulting in the detection of solely monomeric [CuL]+ and [CuL2] complexes. The stability order obtained for the [CuL]+ complexes could be correlated with the deprotonation constants of their hydroxyl group (log bLH) reflecting that the higher acidity increases the complex stability in the order L2 o L1 E L6 o L4 E L5 o L3. This stability order elucidates the different axial linkers in the cyclic dimers 2 and 3. DFT quantum-chemical calculations support the effect of the electron distribution on the established stability order