Biomedical subjects

S Thielke

Publications and source records attributed to S Thielke.

3 recordsLinked to original sources

PubMed2005

Effects of aging prior to freezing on poultry meat tenderness.

The objective of this study was to investigate the effects of aging prior to deboning and deep-freezing on the tenderness of cooked broiler breast fillets. Broilers (Ross-208) that were 37 and 38 d old were slaughtered in a licensed poultry meat plant. After spray chilling, carcasses with BW between 1,080 and 1,300 g were selected for the study and transported to a chilling room (2 to 4 degrees C). The whole carcasses were aged for up to 24 h. During the aging process, continuous measurements were made of pH values, electric conductivity, and firmness of the raw fillets. After the aging process, the carcasses were deboned, and the breast fillets were immediately frozen to an internal temperature of -20 degrees C. Tenderness was measured both mechanically with a Warner-Bratzler shear force device and by sensory testing. The ultimate pH values in the fillets were reached during the first 5 h of aging. Electric conductivity increased during the whole aging period. During the first hours of aging, firmness increased significantly, corresponding with the onset of rigor mortis. After between 8 and 9 h of aging, firmness decreased significantly. Shear force values of aged fillets also changed significantly; the highest values were found at the beginning of aging, which then decreased from the sixth hour. The results of the instrumental tenderness measurements were confirmed by the sensory evaluations. Implementation of in-plant measurements of firmness, thus, seemed to be useful in predicting the sensory quality of poultry meat.

Animals↗

PubMed1998

A method for true coordinate three-dimensional measurement of casts using a measuring microscope.

Exact 3-dimensional measurements are more useful for researchers and clinicians than are relative distance measurements. Through the use of a measuring microscope and a personal computer, the technique presented in this article provides meaningful and accurate (0.005 mm) 3-dimensional measurements of casts in true coordinates (x, y, z). By fabricating the master cast with reference landmarks, leveling the casts before measurement, removing the cast between repeat measures, and mathematically rotating the data points, this technique places all the landmarks in a standardized reference plane that allows for the comparison of dimensional changes between different casts.

Computer Simulation↗

PubMed1998

An accuracy evaluation of four removable die systems.

STATEMENT OF PROBLEM: The advent of implant dentistry has redefined the need for accuracy of working cast models. Die stone expansion and errors introduced by removable die casts may exceed the accuracy required for the passive fit of implant prostheses. PURPOSE: Several removable die systems claim improved accuracy because of their design and/or technical advancements. This study evaluated the 3-dimensional accuracy of 4 removable die systems. All 4 systems tested use either 1 or 2 pins as the repositioning device. MATERIAL AND METHODS: Four removable die systems were evaluated (Belle de St. Claire, Pindex, DVA, and conventional brass dowel system). Master model impressions were made with polyvinyl siloxane material and were later cast with type IV die stone material. Comparative dimensional analysis between the master model and the solid and sectioned casts was made by placing the cast in a standardized position and fabricating an individual custom base for each cast. Landmarks were measured with a traveling microscope, and by mathematically rotating the casts. Discrepancies beyond that of stone expansion or residual stress release at the time of die separation were due to the inability to precisely reposition the removable die of the sectioned cast. Data were analyzed with multivariate analysis of variance and paired t tests at alpha = .05 (n = 10). RESULTS: Significant differences were found among die systems tested (P = .005). When sectioned dies were compared with the master model, the accuracy of all 4 die systems was within 0.055 mm of the master model. Once sectioned, the Pindex system had the least linear expansion in the y dimension, and the brass dowel system demonstrated the least reseating discrepancy in the z (occlusogingival) dimension. CONCLUSIONS: All 4 die systems provided a similar degree of dimensional accuracy, although Pindex showed the least horizontal movement and the brass dowel system produced the least occlusogingival reseating discrepancy.

Analysis of Variance↗