No abstract

A specific experimental method, the split Hopkinson pressure bar (SHPB) technique is used to determine the dynamic material properties under the impact compressive loading condition with strain-rate of the order of 10 3 /s~10 4 /s. The dynamic deformation behavior of rubber materials widely used for the isolation of vibration from varying structures under dynamic loading is determined by using the Split Hopkinson Pressure Bar technique. The relationships between the stresses at transition points of rubber materials and the strain rate are found to be bilinear. However, an interesting relationship between the strains at transition points of rubber materials and the strain rate, which needs further investigation, is noted.

This paper presents the effect of boundary conditions of various failure pressure models published for the estimation of failure pressure. Furthermore, this approach is extended to the failure prediction with the help of a failure probability model. The first order Taylor series expansion of the limit state function is used in order to estimate the probability of failure associated with each corrosion defect in buried pipelines for long exposure periods with unit of years. The effects of random variables such as defect depth, pipe diameter, defect length, fluid pressure, corrosion rate, material yield stress, material ultimate tensile strength and pipe thickness on the failure probability of the buried pipelines are systematically investigated for the corrosion pipeline by using an adapted failure probability model and varying failure pressure model.

While sevoflurane and desflurane have been regarded as inhalation agents providing rapid induction and emergence, previous studies demonstrated the superiority of desflurane-anesthesia compared to sevoflurane-anesthesia in the postoperative recovery in obese and geriatric patients. We investigated whether a short-term switch of sevoflurane to desflurane at the end of sevoflurane-anesthesia enhances patient postoperative recovery profile in non-obese patients. We randomly divide patients undergoing elective surgery (n = 60) into two groups: sevoflurane-anesthesia group (Group-S, n = 30 ) and sevoflurane-desflurane group (Group-SD, n = 30 ). In Group-S, patients received only sevoflurane-anesthesia until the end of surgery (for >2 hours). In Group-SD, sevoflurane was stopped and switched to desflurane-anesthesia before the completion of sevoflurane-anesthesia (for approximately 30 minutes). We assessed the intergroup differences in the times to get eye-opening, extubation, and a bispectral index of 80 (BIS-80). Group-SD showed significantly shorter times to get eye-opening ( 438 ± 101 vs. 295 ± 45   s; mean difference, 143 s; 95% confidence interval [CI], 101–183; p < 0.001 ), extubation ( 476 ± 108 vs. 312 ± 42   s; mean difference, 164 s; 95% CI, 116–220; p < 0.001 ), and BIS-80 ( 378 ± 124 vs. 265 ± 49 minutes; mean difference, 113 s; 95% CI, 58–168 p < 0.001 ) compared to Group-S. There was no between-group difference in postoperative nausea, vomiting, and hypoxia incidences. Our results suggested that the short-term (approximately 30 minutes) switch of sevoflurane to desflurane at the end of sevoflurane-anesthesia can facilitate the speed of postoperative patient recovery.

A specifie experimental method, the split Hopkinson pressure bar (SHPB) technique is used to determine the dynamic material properties under the impact cornpressive loading condition with strain-rate of the order of lO3fs--1O`ls. The dynamic deformation behavior of rubber materials widely used for the lsolation of vibration frorn varying structures under dynamic loading is determined by using the Split Hopkinson Pressure Bar technique. 1'he relationships between the stresses at transition points of rubber materials and the strain rate are fbund to be bi-]inear, However, an interesting relationship between the strains at transition points of rubber materials and the strain rate, which needs further jnvestigation. is nored.