Comparison of Models for Heat Transfer in High-Density Fibrous Insulation.

This study evaluated different models for calculating the effective thermal conductivity of fibrous insulation by comparing predicted values with certified values of Standard Reference Material 1450c, Fibrous Glass Board. This comparison involved the coupled effects of radiation and conduction heat transfer. To support these comparisons, the fiber diameter distribution was measured using X-ray computed tomography, and this distribution was used in several heat transfer models considered in this paper. For the evaluation of the radiative heat transfer, the diffusion approximation, the Schuster-Schwarzschild approximation, and the Milne-Eddington approximation were considered. The conduction of the gas and the fibers was treated by the kinetic theory and a semi-empirical model, respectively. Two models were considered for the evaluation of the radiative properties: the large specular reflecting approach and the application of Mie theory for media composed of infinite cylinders.

Comparison of 4 techniques for limbal-conjunctival autograft fixation in primary pterygium surgery.

PURPOSE: To compare 4 limbal-conjunctival autograft fixation techniques-conventional suture, commercial fibrin glue, autologous fibrin glue, and cautery-in primary nasal pterygium surgery. METHODS: This is a retrospective and descriptive study. The postoperative patient discomfort, graft edema, ocular inflammation, and other complications of 4 limbal-conjunctival autograft fixation techniques in primary nasal pterygium surgery were evaluated. RESULTS: Postoperative patient discomfort was significantly lower with the sutureless techniques (p<0.001), with fixation with cautery having the lowest rate of discomfort. Graft edema and ocular inflammation during the early postoperative period were significantly higher when fibrin glue techniques were used (p<0.001). The recurrence rate did not show a statistically significant difference (p = 0.682) among the 4 groups. CONCLUSION: In primary nasal pterygium surgery, limbal-conjunctival autograft fixation using cautery is the technique with the lowest postoperative discomfort rate and without a statistically significant increase in recurrence rate when compared to conventional suture and fibrin glue techniques.