Experimental Investigation of Damaged Stiffened Cylindrical Shells

Thin walled cylindrical shells, stiffened with rings and longitudinal stiffeners, are components in marine and aeronautical structures. The shells may become damaged in use and require some form of repair to restore some of the strength which may have been lost due to the damage. This paper presents the results of an experimental investigation into the effects of damage, and the efficacy of one method of repair, on an orthogonally stiffened shell. The shells were tested with combinations of external pressure and axial compressive loading. It is shown that local damage reduces the strength of the shell and that the addition of the chosen form of strengthening does not restore the intact strength. However, the efficacy of the repair is greater for a combination of pressure and axial loading.     

MJA practice essentials. Managing schizophrenia in the community

There is an increasing expectation that general practitioners will be more involved in treating people with schizophrenia. Newer drugs are associated with better clinical outcomes, especially in relation to negative symptoms (ie, apathy, under activity, slowness, social withdrawal). Some patients make a full recovery or are quite functional between episodes. Identifying early warning signs will lead to reduction of disability. Side effects of medication must be treated vigorously and expediently to enhance compliance. Secondary symptoms of dysphoria and depression must be treated to prevent suicide. Issues of alcoholism and substance abuse must be addressed, providing education on their implications for the course of the illness. People with schizophrenia need continuity of care, which the general practitioner may be best placed to provide because of a long-term commitment to the patient. Involvement with the family (education, support and a collaborative approach in monitoring and supporting the patient's well-being) is vital.     

Smectic dynamic scattering in laser-addressed liquid crystal projection displays

Two viable methods of producing high-uniformity scattering, suitable for laser-scanned high- resolution light-on-dark contrast liquid crystal projection displays, are reported. The advantages of dynamic scattering over heat-pulse-induced scattering are outlined in terms of power consumption, addressability, uniformity and thermal management.     

Cat scratch disease: magnetic resonance imaging findings

Cat scratch disease is an infectious lymphadenitis frequently occurring in children and adolescents. We present the magnetic resonance imaging findings of two patients with this disease. In both cases, lymphadenopathy was characterized by extensive stranding of the surrounding soft tissues, consistent with the inflammatory nature of this condition. Magnetic resonance imaging can be diagnostic and may obviate the need for invasive means of evaluation in patients suspected of having cat scratch disease.     

Radiographic/morphologic investigation of a radiolucent crescent within the flexor central eminence of the navicular bone in thoroughbreds

The source of a previously described radiolucent crescent in the flexor cortex of the distal sesamoid (navicular) bone on the palmaro45 degrees proximal-palmarodistal oblique (Pa45 degrees Pr-PaDio) clinical radiographic projection was investigated in 48 forelimb navicular bones from 24 Thoroughbreds by use of high-detail radiography and x-ray computed tomography (CT). Twenty-five of these bones also were evaluated, using microradiography and histologic examinations. Of these 25 bones, 5 had been labeled in vivo with fluorochrome markers. Tetrachrome-stained 100-microns-thick nondecalcified sections of these 5 bones were examined, using epifluorescence microscopy. A reinforcement line of compacted cancellous bone, parallel and several millimeters deep to the flexor cortex in the region of the flexor central eminence, was visualized by CT in 42 of 48 navicular bones and by microradiography in 23 of 25 navicular bones investigated. Variable degrees of compaction were observed in the cancellous bone between the flexor cortex and the reinforcement line. High-detail skyline radiographic projections and reconstructed CT images indicated a crescent-shaped lucency within the flexor central eminence of the flexor cortex in the bones in which the reinforcement line was identified, but the cancellous bone between the reinforcement line and the flexor cortex had not been compacted. The radiolucent crescent seen in the flexor central eminence of the navicular bone on the Pa45 degrees Pr-PaDiO projection was not caused by the concave defect or synovial fossa of the flexor central eminence overlying the flexor cortex, as was described.(ABSTRACT TRUNCATED AT 250 WORDS)