The strength reduction method embedded in a distinct element code was used to analyse the stability of a slope in a coal mining area that had been reinforced twice, primarily with pile and retaining wall, followed by porous steel-tube bored grouting. For the primary reinforcement, the factor of safety was calculated, slip surface and failure mechanism were determined, and the damage phenomenon of primary reinforcement was analysed in detail. Failure time of slope without further strengthening was predicted by applying a new quantitative method based on monitoring displacement data. The slope instability at the primary reinforced stage was verified by these analyses. For the second reinforcement, the effect was evaluated by combining the new factor of safety and the final monitoring data, which validates the slope stability. Especially, variations of displacement and factor of safety due to water influence are analysed. Through this procedure, a systemic method for the slope safety evaluation and assurance is presented for engineering practice reference.
The two-body two-impulse orbit transfer problem between two coplanar elliptic orbits using only along-track thrust is studied in this paper. Both impulse vectors are constrained to be on the along-track directions at the impulse points. First, the relationship between transfer angle and final true anomaly is derived. For a given final true anomaly, the range of the transfer angle is obtained for different cases. Then, the transfer angle is solved by the secant method in its feasible range. With the transfer angle and the transfer semilatus rectum, the velocity vectors of the transfer orbit at impulse points are obtained. Two impulse points and the corresponding impulse magnitudes for a 180 • transfer are also analyzed. Finally, the minimum-energy and minimum-transit-time solutions are obtained by optimizing the final true anomaly. Numerical tests demonstrate the effectiveness of the proposed method for two-impulse along-track orbit transfers. The results show that the minimum-energy transfer with two along-track impulses is close to the "true" minimum-energy transfer with two free-direction impulses.
To provide a basis for treating postherpetic neuralgia (PHN), we compared the efficacy of lidocaine and ropivacaine stellate ganglion block (SGB) in PHN treatment in the upper limbs.
Data from 252 patients with upper-limb PHN were retrospectively analyzed. The lidocaine group (n = 118) was treated with oral pregabalin capsules 75 mg twice a day, tramadol hydrochloride sustained release tablets 100 mg twice a day, and amitriptyline 25 mg once at night combined with ultrasound-guided lidocaine SGB; the ropivacaine group (n = 134) was orally administered the same medicines combined with ultrasound-guided ropivacaine SGB. The visual analog scale (VAS), self-rating anxiety scale (SAS), and adverse reactions were compared between the groups before treatment and at 1 week, 1 month, and 3 months after treatment.
There were no significant differences between the lidocaine and ropivacaine groups in terms of sex, age, height, weight, and pain duration (
P
> .05). There was no significant difference between the groups in VAS and SAS scores before treatment (
P
> .05). At 1 week, 1 month, and 3 months after ultrasound-guided SGB treatment, the VAS and SAS scores were significantly lower in the ropivacaine group than in the lidocaine group (
P
< .05). There were no significant differences between the groups in terms of adverse reactions (
P
> .05).
For ultrasound-guided SGB treatment of upper limb PHN, ropivacaine is superior to lidocaine. Ultrasound-guided ropivacaine SGB is safe and effective for the treatment of upper limb PHN.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.