Effects of localized imperfections on compressive strength of long rectangular plates

Results are presented of a numerical study of the buckling and post-buckling behaviour of long rectangular plates under uniaxial longitudinal compression. Consideration is given to various forms of imperfection with particular reference to the influence of localized initial deformation on plate stiffness and strength.     

Gender,Class and Home Ownership: Placing the Connections

This paper contributes to understandings of how gender interacts with the social class implications of home ownership. It is argued that the connections between gender, class and home ownership have only been partially elaborated, and suggested that a more specific focus on identity and the socio-spatial context facilitates a more complex portrayal of these connections. Using material from in-depth, semi-structured interviews with 60 men and women in two neighbourhoods in Vancouver, British Columbia, it will be demonstrated that, contrary to common expectations, home ownership is an important component of both middle-class masculinity and middle-class femininity. However, there is no singular or linear connection between gender, class and home. Instead, there is conflict between familial and status expressions of home, conflict that varies for men and women and according to geographical location.     

RF inductors and capacitors integrated on silicon chip by CMOS compatible Cu interconnect technology

High-Q inductors and high-density capacitors have been designed and fabricated with a post-process of additional metal layers on the top of interconnect layers. The fabrication was carried out with advanced Cu interconnect technology, which was compatible with nowadays CMOS backend of line. The Q_max of inductors with inductance from 0.4 to 11 nH was over 11 on low-resistivity silicon substrates. Two kinds of structures of on-chip capacitors, MIM and MIMIM, have been studied. A capacitance of 1.75 fF/μm² has been achieved with MIMIM structure using Si₃N₄ as dielectric.     

Novel W-band monolithic push-pull power amplifiers

Monolithic W-band push-pull power amplifiers have been developed using 0.1-μm AlGaAs/InGaAs/GaAs pseudomorphic T-gate power HEMT technology. The novel design approach utilizes a push-pull topology to take advantage of a virtual ground between the device pair, eliminating the series feedback of the via hole inductance, and thus improving the performance of the power amplifier at millimeter-wave frequencies. For a two-stage design presented in this paper, the measurement results show a small signal gain of 13 dB and a saturated output power of 19.4 dBm at 90 GHz. The best power added efficiency of 13.3% has been achieved at an output power of 18.8 dBm under a lower bias condition. The gain and efficiency results represent state-of-the-art performance. These are the first reported monolithic push-pull amplifiers at millimeter-wave frequencies     

Microstructure and mechanical properties of Al2O3-Cr2O3-ZrO2 composites

Al₂O₃ is a popular ceramic and has been used widely in many applications and studied in many aspects. On the other hand, zirconia-toughened alumina (ZTA) is a desirable material for engineering ceramics because of its high hardness, high wear resistance and high toughness. In the present research, Al₂O₃-Cr₂O₃-ZrO₂ composites were produced by hot-pressing in order to harden the Al₂O₃ matrix in ZTA. Its microstructure and mechanical properties were studied by SEM, ESCA, XRD, Vickers hardness and bending strength test. It was found that addition of ZrO₂ inhibited the grain growth of Al₂O₃-Cr₂O₃ and the grain growth of ZrO₂ proceeded with increasing amounts of ZrO₂ in the Al₂O₃-Cr₂O₃-Zr₂ composite. The formation of solid solution Al₂O₃-Cr₂O₃ was also confirmed by XRD, and monoclinic ZrO₂ increased on addition of Cr₂O₃. Maximum hardness was at Al₂O₃-10wt% Cr₂O₃ with 10 vol% ZrO₂ and a stress-induced transformation was confirmed on the fracture surface of the specimen after the bending test.     

The Modified Scale for Suicidal Ideation: Reliability and validity.

Developed a modified version of the Modified Scale for Suicidal Ideation (MSSI) for use by paraprofessionals. Modifications included prompt questions, a standardized sequence of administration, modification of the rating points, development of initial screening scores, and selection of items based on internal consistency and relationships with clinical ratings. In 2 studies, 163 psychiatric patients were administered the MSSI and other measures including the Beck Depression Inventory. The MSSI demonstrated excellent internal consistency and interrater reliability, correlated highly with clinician's ratings of suicidal ideation and risk, and discriminated between suicide attempters and nonattempters prior to hospitalization. (3 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Theory of sm1.5Ce0.5sr2Cu2Nbo10: Critical-temperature and doping effects

For Sm_1.5Ce_0.5Sr₂Cu₂NbO₁₀, the charge-reservoir oxygen model of superconductivity predicts: (i) T_c30 K (vs. the observed 28K); (ii) Roughly 1 percent Ni on Cu sites should drive T_c to zero; (iii) The superconductivity originates in the SrO layers; and (iv) The conduction, as with all high-temperature oxide superconductors, is necessarily p-type. The model also explains why this material can superconduct in the presence of the magnetic rare-earth ion Sm and why Gd on Sm sites does not destroy superconductivity, despite structural similarities to Sm_2-zCe_zCuO₄ and Gd_2-zCe_zCuO₄, although the former superconducts and the latter does not.