Further Modification of Pressure-Calcimeter Method for Soil Inorganic Carbon Analysis

Inorganic carbon (IC) in soil is important when considering carbon (C) fluxes and processes in the environment that involve C. Here data are presented for measurement of IC in soils using the pressure-calcimeter method of Sherrod et al. (2002) with modifications to decrease analysis time while preserving method accuracy. Inorganic C measured using a syringe to inject acid vs. the vial delivery method of the original method were not significantly different at the 95 percent confidence level when using 100-ml bottles for the analysis (R² = 0.9946). When using 20-ml bottles, bias was introduced in the measurement when using a syringe for acid delivery, likely due to small losses of pressure from the bottle during acid delivery. There was no significant difference at the 95 percent confidence level in IC measured on unsieved finely ground and coarsely ground soil. When quantifying IC in soils using the modified pressure calcimeter method with a 100-ml bottle, a syringe can be used to inject acid into the capped bottle rather than dropping a vial into the bottle and then capping it. This modification results in a modest reduction in cost and significant reduction in time required for analysis and cleanup.     

Comparison of the TONOVET Plus®, TonoVet®, and Tono-Pen Vet™ tonometers in normal cats and cats with glaucoma

Objectives

To determine the accuracy, precision, and clinical applicability of the ICare® TONOVET Plus (TVP) in cats.

Animals and Procedures

IOP readings obtained with the TVP were compared to values obtained concurrently with the original TONOVET (TV01) and Tono-Pen Vet™ (TP) in 12 normal cats (24 eyes) and 8 glaucomatous LTBP2-mutant cats (13 eyes) in vivo. Reproducibility of TVP readings was also assessed for three observers in the above cats. The anterior chambers of five different normal cat eyes were cannulated ex vivo. IOP was measured with the TVP, TV01, and TP at manometric IOPs ranging from 5 to 70 mmHg. Data were analyzed by linear regression, ANOVA and Bland–Altman plots. ANOVA was used to assess reproducibility of TVP readings obtained by different observers and an ANCOVA model controlled for variation of individual cats. p < .05 was considered significant.

Results

TVP values strongly correlated with TV01 values (y = 1.045x + 1.443, R² = .9667). The TP significantly underestimated IOP relative to the TVP and TV01, particularly at high IOP. IOP values obtained by 1 observer were significantly higher (~1 mmHg average) compared to the other 2 observers via ANCOVA analysis (p = .0006479 and p = .0203). Relative to manometry, the TVP and TV01 were significantly more accurate (p < .0001) and precise (p < .0070) than the TP in ex vivo eyes.

Conclusions

IOP readings obtained with the TVP and TV01 are broadly interchangeable between models and between observers, but subtle differences may be important in a research context. TP readings vastly underestimate high IOP in feline glaucoma.     

Volumetric evaluation of fluid responsiveness using a modified passive leg raise maneuver during experimental induction and correction of hypovolemia in anesthetized dogs

ObjectiveTo demonstrate if modified passive leg raise (PLR_M) maneuver can be used for volumetric evaluation of fluid responsiveness (FR) by inducing cardiac output (CO) changes during experimental induction and correction of hypovolemia in healthy anesthetized dogs. The effects of PLR_M on plethysmographic variability index (PVI) and pulse pressure variation (PPV) were also investigated.Study designProspective, crossover study.AnimalsA total of six healthy anesthetized Beagle dogs.MethodsDogs were anesthetized with propofol and isoflurane. They were mechanically ventilated under neuromuscular blockade, and normothermia was maintained. After instrumentation, all dogs were subjected to four stages: 1, baseline; 2, removal of 27 mL kg^–1 circulating blood volume; 3, after blood re-transfusion; and 4, after 20 mL kg^–1 hetastarch infusion over 20 minutes. A 10 minute stabilization period was allowed after induction of each stage and before data collection. At each stage, CO via pulmonary artery thermodilution, PVI, PPV and cardiopulmonary variables were measured before, during and after the PLR_M maneuver. Stages were sequential, not randomized. Statistical analysis included repeated measures anova and Tukey’s post hoc test, considering p < 0.05 as significant.ResultsDuring stage 2, PLR_M at a 30° angle significantly increased CO (mean ± standard deviation, 1.0 ± 0.1 to 1.3 ± 0.1 L minute^–1; p < 0.001), with a simultaneous significant reduction in PVI (38 ± 4% to 21 ± 4%; p < 0.001) and PPV (27 ± 2% to 18 ± 2%; p < 0.001). The PLR_M did not affect CO, PPV and PVI during stages 1, 3 and 4.Conclusions and clinical relevanceIn anesthetized dogs, PLR_M at a 30° angle successfully detected FR during hypovolemia, and identified fluid nonresponsiveness during normovolemia and hypervolemia. Also, in hypovolemic dogs, significant decreases in PVI and PPV occurred in response to PLR_M maneuver.     

谈钻孔压浆端承桩施工中几个问题

本文主要讨论了钻孔压浆桩施工中桩长的确定,钢筋笼子的安放,水灰比的确定等措施。     

粘性土挡墙主动土压力计算研究

对现有的计算方法进行了归纳总结，其中重点介绍了最近提出 的内压力法，通过理论上的分析论证和工程算例的验证，表明内压力法是一种比较准确且简便实用的计算方法，建议在工程上推广应用。     

欧洲云杉引种试验研究

为确定鄂西地区欧洲云杉的适生区域,进行欧洲云杉德国种源引种栽培试验,试验结果表现良好,25 a生林分树高13.2 m,平均胸径19.8 cm,材积0.206 2 m3,材积比人工林杉木、巴山松、油松提高38.7%~46.9%。海拔区域试验表明6 a生欧洲云杉林分树高生长量在海拔1 060~1 916 m差异不显著,适宜鄂西山区海拔1 500~1 900 m,年降水量1 000mm以上的区域营造工业原料林或种子园。     

人工林杉木压缩整形过程中的定形工艺

以蒸汽压力、时间及定形结束时蒸汽卸压速度为参数,对杉木压缩整形工艺的定形进行了试验.结果表明:1)整形过程中定形的蒸汽压力、定形时间对杉木定形后的体积压缩恢复率影响显著,而定形完成后的蒸汽卸压速度无显著影响;2)定形的蒸汽压力、定形时间的各个水平之间的定形效果差异极显著,理想的定形效果是在0.8 MPa的饱和蒸汽压下持续40 min.     

大口径球磨铸铁管道施工浅议

作者通过哈尔滨高科技开发区大口径球磨铸铁管道的施工,介绍了大口径球磨铸铁管道的施 工程序、要求及注意事项。