Brittle Rock Failure in the Steg Lateral Adit of the Lötschberg Base Tunnel

Summary: During the crossing of brittle rock formations at the Lötschberg base tunnel, failure phenomena have been observed both at the tunnel face and at the walls. A detailed analysis has been undertaken to explain these behaviours, based on the recent developments of Canadian research on brittle failure mechanisms. At the tunnel walls, a very good agreement is found between the calculated and observed damage and between two prediction methods, i.e. a semi-empirical failure criterion and elastic calculations with the "brittle Hoek-Brown parameters.” Near the face, due to the 3D nature of the stress conditions, some limitations of these approaches have been highlighted, and the growth of wall failure has been analysed. This research allowed a better understanding of the brittle rock mass behaviour at the Lötschberg base tunnel and showed that brittle failure processes dominate the behaviour of deep, highly stressed excavations in massive to moderately jointed rock. It also illustrates where improvements to the adopted approaches are require

Empirical comparison of high gradient achievement for different metals in DC and pulsed mode

For the SwissFEL project, an advanced high gradient low emittance gun is under development. Reliable operation with an electric field, preferably above 125 MV/m at a 4 mm gap, in the presence of an UV laser beam, has to be achieved in a diode configuration in order to minimize the emittance dilution due to space charge effects. In the first phase, a DC breakdown test stand was used to test different metals with different preparation methods at voltages up to 100 kV. In addition high gradient stability tests were also carried out over several days in order to prove reliable spark-free operation with a minimum dark current. In the second phase, electrodes with selected materials were installed in the 250 ns FWHM, 500 kV electron gun and tested for high gradient breakdown and for quantum efficiency using an ultra-violet laser.Comment: 25 pages, 13 figures, 5 tables. Follow up from FEL 2008 conference (Geyongju Korea 2008) New Title in JVST A (2010) : Vacuum breakdown limit and quantum efficiency obtained for various technical metals using DC and pulsed voltage source

The silane depletion fraction as an indicator for the amorphous/crystalline silicon interface passivation quality

In silicon heterojunction solar cells, thin amorphous silicon layers passivate the crystalline silicon wafer surfaces. By using in situ diagnostics during plasma-enhanced chemical vapor deposition (PECVD), the authors report how the passivation quality of such layers directly relate to the plasma conditions. Good interface passivation is obtained from highly depleted silane plasmas. Based upon this finding, layers deposited in a large-area very high frequency (40.68 MHz) PECVD reactor were optimized for heterojunction solar cells, yielding aperture efficiencies up to 20.3% on 4 cm

Clinical Application of Low-dose Calcium Regulating Neural Inhibitor in Related Renal Transplantation

摘要 目的探讨低剂量钙调节神经素抑制剂在亲属活体肾脏移植中的安全性与效果。 方法回顾性总结厦门大学附属东南医院亲属活体肾脏移植患者122例：其中除4例为夫妻间供肾移植外其余均为血缘亲属关系供肾。人类白细胞抗原（HLA）全配7例，1个抗原错配20例，2个抗原错配23例，3个抗原错配72例。血型相同者91例，相容者31例。122例供者均经开放式手术取肾，供者取左肾105例，取右肾17例。术后均采用环孢素A(CsA)或他克莫司(TAC)、霉酚酸酯(MMF)及皮质激素(Pred)经典三联免疫抑制剂方案治疗，其中环孢素A方案71例，他克莫司方案51例。根据术后免疫抑制方案中钙调节免疫抑制剂（CNIs...Abstract Aim: Discusses the safety and effection of low-dose calcineurin inhibitors (CNIs) used in living relative donor kidney transplantation. Methods: One hundred and twenty-two patients with living relative donor kidney transplantation in Southeast Hospital Affiliated to Xiamen University were enrolled in this retrospective study. Expect for 4 patients donated by their spouses, the others h...学位：医学硕士院系专业：医学院临床医学系_外科学学号：2452009115299

Comportement de l’écran de soutènement d’une tranchée expérimentale étroite

Le comportement de l'écran de soutènement d'une tranchée expérimentale étroite a été étudié au moyen de la méthode des éléments finis et de la méthode des modules de réaction. La confrontation des résultats numériques aux mesures de déplacements réalisées in situ a permis de comparer les performances de chacune des méthodes et de préciser leurs limites. L'importance d'une détermination représentative des modules de déformation est démontrée en s'appuyant notamment sur l'évolution des modules pressiométriques observée en fin d'excavation dans la zone du fond de fouille