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Objective: To evaluate the diagnostic performance of diffusion-weighted magnetic resonance imaging (DWI) to predict the histopathologic grade of hepatocellular carcinoma (HCC). Methods: The DWI images of 40 patients (20 well differentiated, 13 moderately differentiated, 7 poorly or undifferentiated) diagnosed histopathologically with HCC before treatment were evaluated retrospectively. Apparent diffusion coefficient (ADC) values obtained from DWI were measured for each lesion. The differences in the ADC values of histopathological subgroups were evaluated using the Kruskal-Wallis test, then the Mann Whitney-U test for pairwise comparision. The correlation between parameters was evaluated using the Spearman correlation test. Receiver operating characteristics curve analysis was used to evaluate the diagnostic performance. Results: The median ADC value of poorly and undifferentiated HCCs (0.600 x 10-3 mm² / sec) was statistically significantly lower than moderately differentiated (0.730 x 10-3 mm² / sec) and well differentiated (0.938 x 10-3 mm² / sec) HCCs (p <0.001). A strong negative-correlation was found between the histopathological grade of HCC and ADC (r = 0.796, p <0.001). Conclusion: ADC can be useful as a non-invasive diagnostic tool in predicting the histologic subtypes of HCC. [ABSTRACT FROM AUTHOR]

The effect of process parameters, such as pressure (20, 35, 55 MPa), temperature (323 and 343 K), and CO2 flow rate (1 and 3 L CO2 /min) on the extraction yield and effective diffusivity (De) was investigated. The effective diffusion coefficient varied between 2.4 x10-12 and 10.8 x10-12 m² s-1 for the entire range of experiments and increased with the pressure and flow rate. The model fitted well the experimental data (ADD varied between 2.35 and 7.48%). [ABSTRACT FROM AUTHOR]

In this study, correlation between heat transfer on Jominy sample and hardenability is investigated. For this purpose, thermocouples are placed on Jominy sample and recorded dependent time temperature data. Theoretical analyses are estimated by using one-dimensional transient heat transfer equation and finite difference method. Experimental and theoretical conclusions are compared, hardness depth of Jominy sample can be estimated theoretically using by the different variations of Jominy experimental parameters that the heat conduction coefficient, diffusion coefficient, specific heat, intensity and heat convection coefficient. [ABSTRACT FROM AUTHOR]