Gap Geometry Measurements in Oil-Filled Gaps Using Laser Diffraction Techniques

This paper describes an experimental investigation of utilizing laser diffraction method for gap geometry measurements of oil-filled gaps with gap widths in the range of a few hundred microinches up to 0.03 inches, with applications to research areas, such as journal bearings, seals, and EHD lubrication. Diffraction patterns are obtained for various gap widths and depths of gaps for dry gaps and oil-filled gaps with different kinds of lubricating oils in the gaps. It is shown that, for dry gaps, a good correlation is obtained between diffraction patterns and gap widths, for narrow depth of gaps. An increase in depth of gap yields significant differences between experimental results and classical theoretical results, probably due to internal reflections of the light beam within the deeper gaps. For oil filled gaps, experimental results yield smaller gap widths than those calculated from simple diffraction theory, because of distortion of diffraction patterns due to the presence of oil in the gaps. Correcting factors are obtained to account for the optical characteristics of oils in the gaps. It is shown that the values of correcting factors approach asymtotic values with an increase in gap widths, due to change in optical characteristics of the lens formed by oil meniscus in the gaps. It is established that the laser diffraction technique can be applied for gap measurement of small oil-filled gaps. The limitations of the technique are also established.     

Identification of seven Treponema species in health- and disease-associated dental plaque by nested PCR

Species-specific nested PCR was used to detect Treponema amylovorum, Treponema denticola, Treponema maltophilum, Treponema medium, Treponema pectinovorum, Treponema socranskii, and Treponema vincentii in dental plaque. Subjects with periodontitis harbored all species, but T. pectinovorum and T. vincentii were not found in plaque from disease-free subjects.     

Comparison of nested polymerase chain reaction, virus isolation, and fluorescent antibody testing for identifying feline herpesvirus in cats with conjunctivitis

OBJECTIVE: To compare nested polymerase chain reaction (PCR), virus isolation (VI), and fluorescent antibody (FA) testing to detect feline herpesvirus (FHV) in cats with naturally acquired conjunctivitis or respiratory tract disease, or both. SAMPLES: Swab and microbrush specimens from the conjunctiva and throat were taken from 46 cats, allotted to 3 groups (conjunctivitis only, respiratory tract disease and conjunctivitis, and clinically normal). PROCEDURE: Cells from microbrush specimens were digested and herpesvirus DNA was amplified, using a double round of PCR. Products were detected by use of agarose gel electrophoresis. The VI and FA tests were performed in routine manner. RESULTS: Of 16 cats with conjunctivitis only, conjunctival specimens from 8 and throat specimens from 8 were FHV positive by PCR. None had positive results of VI or FA testing. Of 15 cats with respiratory tract disease and conjunctivitis, conjunctival specimens from 13 and throat specimens from 12 were FHV positive by PCR. A conjunctival specimen from 1 cat and throat specimens from 3 cats were FHV positive by VI. A conjunctival specimen from 1 cat was FHV positive by FA testing. Of 15 clinically normal cats, conjunctival and throat specimens from 2 cats were FHV positive by PCR; neither conjunctival nor throat specimens from these cats were FHV positive by VI or FA testing. CONCLUSION: For cats with respiratory tract disease and conjunctivitis, or with conjunctivitis only, nested PCR was more sensitive at detecting FHV than was VI or FA testing. CLINICAL RELEVANCE: Nested PCR is a more sensitive test than the currently available VI and FA tests for identifying FHV in cats with conjunctivitis.     

Demand-side management impact on the transmission and distributionsystem

A project to assess the impact on the transmission and distribution (TD) system due to the implementation of demand-side management (DSM) programs is described. Traditional TD planning methods are reviewed and procedural changes necessary to fully integrate DSM strategy analysis with the system planning process are discussed. Test procedures and results are discussed for a study conducted at a host utility. Several DSM strategies are analyzed to assess the impacts on a TD system serving a large metropolitan area     

Mechanisms of strain accumulation and damage development during creep of prestrained 316 stainless steels

The effects of prestraining at room temperature and at the creep temperature of 848 K, as well as the responses to stress reductions during creep, have been studied for 316 stainless steels varying in composition and initial microstructure. The results are analyzed by contrasting the strengthening effects achieved by introducing high dislocation densities prior to creep exposure with the deleterious effects, which can occur when prestraining causes premature void nucleation at grain boundaries. In addition, by recognizing the differing contributions made by the grain interiors and the grain boundary zones to the overall rates of creep strain accumulation, a consistent explanation is provided for the diverse creep behavior patterns reported for different metals and alloys after various prestraining treatments.     

Invention from War: a circumstantial modernism for Australian architecture

Between 1942 and 1945, Australian architects and engineers within the Allied Works Council and the US Army Corps of Engineers undertook a vast programme of building works to assist the campaign to drive Japanese forces northward through the Southwest Pacific and avoid invasion.¹ Huge distances, lack of time and the need to wage a campaign from the air lay behind US General Douglas Macarthur's phrase that it would be an 'engineer's war'. By necessity, buildings such as airfields, hospitals, camps, warehouses, and other structures had to be light weight, constructed quickly, and inevitably dropped in by air as easily handled pre-cut packages. With the lack of American and European softwoods in the Australasian region, an unlikely local material was pressed into war service - unseasoned or 'green' Australian hardwood. It was a material choice that would have profound implications for two reasons. First, in the years of conflict, circumstances dictated the unprecedented innovation and experiment in light-weight timber structures. Second, in an echo of Lewis Mumford's poignant maxim that 'war is the health of the machine'², the systematisation and ruthless economy inherent in wartime timber buildings would influence the development and practice of a particular form of modern architecture in Australia in the late 1940s and the 1950s.     

Voice services in the evolving telecommunications network

Telephone services based on stored voice have existed for many years in the guise of the Speaking Clock and other recorded information services. Digital speech storage, computer control and customer signalling, based on automatic speech recognition or multi-frequency keypads, make possible better voice-based information and message services. New voice services equipment that implements some of these facilities has just entered service.     

High-throughput sample preparation for gene expression profiling and in vitro target validation

The demand for high-throughput RNA isolation has been dramatically increasing with wide applications of RNAi, expression profiling, and molecular diagnosis. A comparison of various RNA isolation methods that have been adapted to high-throughput platforms, focusing on consistently high yield and quality of isolated RNA, reduction of cross-contamination, and simplicity and robustness of the protocol is presented. The streamlining of RNA isolation with RNA quantification by qRT-PCR and amplification for microarray analysis is also discussed. In general, a microspheric bead-based approach results in more consistent RNA recovery than glass fiber filter-based RNA isolation method, and RNA can be eluted in a smaller volume. This is because beads can be fully re-suspended in solution to enable more thorough mixing, washing, and elution, whereas the glass fiber matrix is fixed in a filter plate.