ABSTRACT
This study reports the direct thermal observation of the junction temperature and determination of the thermal resistance in a commercial solar cell package under actual operating conditions. A thermal transient method was the key method that was utilized for the thermal characterization of the device. Sunlight directed into the solar cell package was found to increase significantly the heat generation inside the solar cell package. It was shown that the operation of the solar cell package with sunlight of 1 sun resulted in a junction temperature of about 113 degrees C. The simulation data were in good agreement with the measured values. Detailed thermal performance of the solar cell package was projected using a Computational Fluid Dynamics (CFD) method under various operating conditions. Thermal resistance was determined under various operating conditions.
ABSTRACT
A prospective and longitudinal investigation concerning clinical outcomes and morphologic changes of large lumbar disc herniations by MR imaging. To compare the clinical outcomes and the natural morphologic changes of between sequestered and large central extruded disc herniations. The spontaneous disappearance or diminution of large herniated lumbar discs in the spinal canal is known. Poor clinical outcome and small changes of herniated discs have been shown for large central extruded disc herniations with conservative treatment. The study population consisted of 22 patients with sequestration and a large central as extrusion established by an MR imaging study. Seventeen (11 patients with sequestration, and 6 patients with a large central extrusion) patients underwent a follow-up MR imaging study. The size of the herniated disc was measured on serial MR imaging studies, and the changes in size were classified into four categories. Clinical evaluations were also performed using a visual analogue scale (VAS), the Oswestry low back pain disability questionnaire, the straight leg raising test (SLRT) and so forth. Both the sequestered and large central extruded disc herniations showed a successful clinical outcome after conservative treatment in 17 of 22 patients (77%) in total: 11 of 13 patients (85%) with sequestered disc herniations, and 6 of 9 patients (67%) with large central extruded disc herniations. VAS and Oswestry disability scoring showed a greater change in the group with sequestration than in the group with large central extrusions. In the group with sequestration, seven patients reported the disappearance of herniated disc materials, and four patients showed a marked decrease in the size of their herniated discs in follow-up MR images. However, in the group with large central extrusions, only two patients showed a decrease in the size of their herniated discs. Large central extruded disc herniations can be treated successfully by conservative treatment. Outcomes seemed to be as good as or slightly inferior to those of sequestered disc herniations. However, a greater morphologic decrease in the herniated discs occurred more frequently for sequestered disc herniations than for large central extruded disc herniations.
