Search

To establish a prediction model of renal calculus for university teachers to help them prevent renal calculus scientifically. This study involves a specific group of university teachers. We collected the physical examination index of 1043 university teachers in the Hubei University of Chinese Medicine in 2018 to build the model. We also used the physical examination data of 968 teachers in 2019 to verify the model.We used Lasso regression to screen the factors and logistic regression analysis to establish the model.The models of this study included sex, age, DBP, TC, HDL. C, CEA, UA, ALT, GGT, HB, pH, RBC, RDW, and CLYMPH. Among these, sex, TC, ALT, HB, and LYMPH present high risks in the model. The result is of great significance related to the research of university teachers suffering from renal calculus. The C-index is 0.715, and the AUC is 0.7064.Based on the results of this study, we suggest that physical examination indicators can predict the risk of renal calculus and the individual probability of prevalence in specific groups. According to the risk of each physical examination index, it is possible to effectively prevent the occurrence of renal calculus in certain high-risk groups through lifestyle changes.

A theoretical and experimental investigation was conducted to study the wick combustion of lithium (Li) and sulfur hexafluoride (SF6). The wick combustion experiments were conducted in a vacuum chamber at a pressure of 0.01 MPa. At this condition, the wick combustion of Li and SF6 yields a bright luminous flame. During the combustion, the lithium bath temperature was maintained near its saturation temperature at the system pressure. A prediction model based on the conserved-scalar approach is presented along with an interface analysis. The predicted interface temperature was in agreement with the experimental liquid bath temperature. The model prediction yields a reasonable flame stand off distance as compared to the experiments reported elsewhere. The flowfleld analysis shows self-similar solutions for planar wick combustion of Li and SF6 and nonsimilar solutions for the cylindrical wick combustion. Property variations and wick curvature are found important to the flowfleld prediction of the Li-SF6 wick diffusion flame. Nomenclature A - parameter, Eq. (15) c - parameter, Eq. (8) D - binary diffusion coefficient DK - species parameter, Eq. (28) / = dimensionless stream function, Eq. (7) Gr = Grashof number, Eq. (15) g - acceleration of gravity H = plate or cylinder height h = enthalpy k - thermal conductivity L = enthalpy of gasification NK - species parameter, Eq. (28) Pr = Prandtl number T - temperature u - streamwise velocity v = cross-stream velocity x = streamwise direction y, = mass fraction of species / y = cross-stream direction y0 = radius of cylindrical wick Z = mixture fraction 17 = similarity variable, Eq. (10) jti = dynamic viscosity v — kinematic viscosity f = similarity variable, Eq. (10) p - density ^ = stream function, Eq. (9) a) = source term to account for the polymerization of gas species, Eq. (21)

A numerical model based on a conserved-scalar approach is presented for buoyant ethanol-air wick diffusion flames at atmospheric and subatmospheric conditions. The model incorporates an equation that describes the interface condition of wick combustion. The prediction yields similarity solutions for flat-plate ethanol-air wick diffusion flames, but not for cylindrical wick diffusion flames. The flat-plate solution yields a mass burning rate per unit surface area following the x −1 4 dependence of the classical similarity solution, where x is the streamwise distance. A pressure dependence of P0.644 is predicted for the flat-plate overall mass burning rate, in agreement with the P 2 3 dependence reported in the literature. The cylindrical wicks have a mass burning rate per unit surface area that deviates from the x −1 4 dependence. The predicted mass burning rate, however, does not substantially deviate from the flat-plate solution for cylinders with a moderate aspect ratio (of the order one). The deviation in mass burning rate is most pronounced when needle-like cylinders are considered. The variable-property effects are also examined. The results show that the Chapman gas and constant-Prandtl-number assumptions are not adequate for wick diffusion flames, even at the subatmospheric-pressure condition studied.