Theoretical and numerical research on effect of tension mechanisms in strip flatness electromagnetic control rolling mills

To achieve stable rolling,the influence of a tension mechanism of a large diameter ratio roll system on the rolling process of a strip flatness electromagnetic control rolling mill is studied.Through the analysis of the rolling deformation zone,the deformation zone composition form of a large diameter ratio roll system and a calculation formula of neutral angle under tension are proposed.To analyze the effect of front and post tensions on the rolling characteristic and the strip flatness control characteristic,a three-dimensional rolling finite element(FE)model of a large diameter ratio roll system with the function of roll profile electromagnetic control is established by FE software and verified by a strip flatness electromagnetic control rolling mill.Based on the model,the strip thickness characteristic,metal transverse flow,strip flatness state,and adjustment range of the loaded roll gap are analyzed for different front and post tensions setting values.The results show that changing the front or post tension setting values can improve the single-pass reduction rate of a large diameter ratio roll system and have little effect on the flatness control ability of the strip flatness electromagnetic control rolling mill.

Mechanical tension promotes skin nerve regeneration by upregulating nerve growth factor expression

This study aimed to explore the role of mechanical tension in hypertrophic scars and the change in nerve density using hematoxylin-eosin staining and S100 immunohistochemistry, and to observe the expression of nerve growth factor by western blot analysis. The results demonstrated that mechanical tension contributed to the formation of a hyperplastic scar in the back skin of rats, in conjunction with increases in both nerve density and nerve growth factor expression in the scar tissue. These experimental findings indicate that the cutaneous nervous system plays a role in hypertrophic scar formation caused by mechanical tension.

Effect of MgO and SiO_2 on surface tension of fluoride containing slag

Surface tensions of slag addition Mg O and Si O2 based on conventional 70%CaF 2-30%Al2O3 and 60%Ca F2-20%Ca O-20%Al2O3(mass fraction) at 1300 °C, 1400 °C and 1500 °C were investigated. Influence mechanism of Mg O and Si O2 on slag surface tension was also analyzed. Results indicate that surface tension decreases with the increase of Mg O content in the case of the Mg O content(mass fraction) less than 8%, however, when Mg O content(mass fraction) is from 8% to 30%, surface tension increases with the increase of Mg O content. When Si O2 content(mass fraction) is from 2% to 8%, surface tension decreases with the increase of Si O2 content. Additionally, the relationship between surface tension and optical basicity is a monotonically increasing linear function. Research findings can provide important reference for slag design and the study of slag-metal interfacial tension.

Influence of local tensile loading on the distribution of welding residual stress fields in cylinder shells

The feasibility of reducing the welding residual stress through local tensile loading is verified using the finite element method （FEM）. The mechanism and effect of reducing stress during and after welding are compared. The results show that the effect of the former is better than that of the latter. Applying an external tension load of 200 MPa after welding, the maximum residual stress drops down from 235 MPa to about 90 MPa, moreover, it decreases to 30MPa when an external tension load of 200 MPa is applied during welding.

Expression of ectonucleotide pyrophosphatase-1 in end-plate chondrocytes with transforming growth factor beta 1 siRNA interference by cyclic mechanical tension

Background Ectonucleotide pyrophosphatase/phosphodiesterase （ENPP）-I is a membrane-bound protein that catalyzes the hydrolysis of extracellular nucleoside triphosphates to monophosphate and extracellular inorganic pyrophosphate （ePPi）. Mechanical stimulation regulates ENPP-1 expression. This study sought to investigate the changes in ENPP-1 expression after stimulation using cyclic mechanical tension （CMT）.