2012;27:632-644) DOI: 10.3305/nh.2012.27.2.5556″
“In order to reveal the disaster mechanism of hydraulic fracturing for hydraulic tunnel, force analysis of hydraulic tunnel and research on crack propagation is combined in this paper. Theory of Stress Intensity Factor is introduced into the analytical solution as the criterion of crack propagation. Dividing SU5402 clinical trial cracks into shear-tensile and shear-compressive types, formulas calculating critical inner water pressure of crack propagation for hydraulic tunnel are attained. On the basis above, the influence of geological condition (rock cohesion and friction angle, geostress and pore water pressure) on the critical water pressure of hydraulic tunnel is analyzed. The computation results show that increases of both cohesion and friction angle for rock mass are advantageous to prevent occurrence of crack propagation on the tunnel wall. The more prominently
pore water pressure influences, the more easily cracks of both shear-tensile and shear-compressive types propagate and the more disadvantageous stability of hydraulic tunnel will be. Moreover, with the geostress diminishing, cracks will be more likely to expand.”
“Subirrigation is being adopted as an environmentally friendly strategy for managing the nutrition of potted greenhouse plants. Here, we investigated two selleck chemical strategies for enhancing the remobilization of N during the development of the inflorescence in subirrigated potted chrysanthemum (Chrysanthemum morifolium Ramat.) in an attempt to improve nitrogen
(N) use efficiency. (1) The replacement of a portion of the nitrate in the nutrient solution with ammonium decreased the nitrate content, AZD2014 especially in the stem plus petioles, and increased the reduced N content early in the growth cycle, but did not improve N use efficiency. (2) The use of a lower N supply (200 vs. 400 mg total N per pot delivered over 3 and 5 wk, respectively), either as nitrate or ammonium nitrate, eliminated nitrate accumulation prior to inflorescence development, thereby improving N use efficiency. Inflorescence quality was unaffected; however, at the lower N level there was some evidence of chlorosis on the oldest leaves. Thus, there may be considerable potential to reduce the N supply in a commercial greenhouse setting as long as an adequate supply is provided early in the growing period.”
“Melatonin regulates the reproductive cycle, energy metabolism and may also act as a potential antioxidant indoleamine. The present study was undertaken to investigate whether long-term melatonin treatment can induce reproductive alterations and if it can protect ovarian tissue against lipid peroxidation during ovulation. Twenty-four adult female Wistar rats, 60 days old (+/- 250-260 g), were randomly divided into two equal groups. The control group received 0.3 mL 0.9% NaCl + 0.04 mL 95% ethanol as vehicle, and the melatonin-treated group received vehicle + melatonin (100 mu g.