Toughening of Dental Porcelain by Tetragonal ZrO2 Additions

The effect on mechanical behavior of ZrO₂ additions to a dental porcelain was investigated. The ZrO₂ was introduced into the glassy matrix phase of the porcelain by refritting the all-glass porcelain constituent. X-ray diffraction indicated that a sizeable fraction of the ZrO₂ was retained in the tetragonal form after the porcelain was fired. Zirconia additions to the porcelain produced substantial improvements in fracture toughness, strength, and thermal shock resistance.     

Red blood cell glutathione status in patients with gastrointestinal malignancies treated with 5-fluorouracil

As an alternative to surgical splenectomy, partial splenic embolization was performed in seven children for hypersplenism manifested by splenomegaly, thrombocytopenia, leukopenia, and erythrocyte hemolysis. Within a few days, platelet and leukocyte counts rose significantly in all patients and were maintained in six of seven patients during a follow-up period of 9 to 69 months. Spleen size and abdominal distention also decreased significantly in all children. There were no infectious complications.     

Investigating the Social Dimensions of Transport Disadvantage II: From Concepts to Methods through an Empirical Case Study

This article is the second of two papers that review the field of spatially sensitive social scientific research into the links between social status and transport disadvantage. The first paper undertook a comprehensive review of the social scientific and transport planning literature to mark the level of development in the field and identify conceptual and methodological issues and constraints in this field of inquiry. The present article supports the advancement of socially and geographically sensitive transport research by opportunities for the development of more sophisticated spatial analytical methodologies. The approach we present is able to account for factors not previously addressed in either social or transport planning research, in particular the temporal dimensions of transport service accessibility. The article articulates the methodology through an empirical case study of socio-spatial transport disadvantage within the Gold Coast City. The article demonstrates that there are important theoretical and practical lessons to be gained for researchers and policy makers in addressing the social dimensions of transport and infrastructure provision. Further, the article argues that an attentiveness to new ways of combining and representing social and transport data-sets can promote policy relevant empirical social inquiry. The article also contributes in a productive way to the empirical knowledge of Australia's sixth-largest metropolitan area, which is often overlooked by urban scholars.     

A note on the use of conductimetry in brewery microbiological control

The growth in beer of 15 brewery strains of Lactobacillus was detected using the automatic conductance measuring technique afforded by the Malthus 8 Growth Analyser. 0·15% ammonium chloride was added to the beer as an electrolyte and sodium acetate was used to raise the pH from ca 4·0 to 4·2 or above. No measurable responses were obtained using unmodified beer. The value of the method for development in routine brewery microbiological control is briefly discussed.     

The Silicon Backplane Design for an LCOS Polarization-Insensitive Phase Hologram SLM

Polarization-insensitivity is achieved in a reflective spatial light modulator by laying a quarter-wave plate (QWP) at the incident wavelength directly over the mirror pixels of a silicon backplane, and forming a nematic Freedrickcz cell over the QWP to modulate the reflected phase. To achieve the highest drive voltage from the available silicon process, a switched voltage common front electrode design is described, with variable amplitude square wave drive to the pixels to maintain constant root-mean-square drive and minimize phase fluctuations during the dc balance refresh cycle. The silicon has been fabricated and liquid-crystal-on-silicon cells both with and without the QWP assembled; applications include optically transparent switches for optical networks, beam steering for add-drop multiplexers for wavelength-division-multiplexing telecommunications, television multicast, and holographic projection.     

Energy consumption modeling and optimization for SRAM's

The recent trends in portable computing technologies have established the need for energy efficient design strategies. To achieve minimum energy design goals, system designers need a technique to accurately model the energy consumption of their design alternatives without performing a full physical design and full-circuit simulation. This paper presents and compares five approaches for modeling the energy consumption of CMOS circuits. These five modeling approaches have been chosen to represent the various levels of model complexity and accuracy found in the current literature. These modeling approaches are applied to the energy consumption of SRAM's to provide examples of their use and to allow for the comparison of their modeling qualities. It was found that a mixed characterization model-using a CV² prediction for digital subsections and fitted simulation results for the analog subsections-is satisfactory (within ±1 process variation) for predicting the absolute energy consumed per cycle. This same model is also very good (within 2%) for predicting an optimum organization for the internal structures of the SRAM. Several common architectures and circuit designs for SRAM's are analyzed with these models. This analysis shows that global, rather than local improvements, produce the largest energy savings