Flexural behaviour of hybrid steel-GFRP reinforced concrete continuous T-beams

YesThis paper presents test results of six full scale reinforced concrete continuous T beams. One beam was reinforced with glass fibre reinforced polymer (GFRP) bars while the other five beams were reinforced with a different combination of GFRP and steel bars. The ratio of GFRP to steel reinforcement at both mid-span and middle-support sections was the main parameter investigated. The results showed that adding steel reinforcement to GFRP reinforced concrete T-beams improves the flexural stiffness, ductility and serviceability in terms of crack width and deflection control. However, the moment redistribution at failure was limited because of the early yielding of steel reinforcement at a beam section that does not reach its moment capacity and could still carry more loads due to the presence of FRP reinforcement. The experimental results were compared with the ultimate moment prediction of ACI 440.2R-17, and with the existing theoretical equations for deflection prediction. It was found that the ACI 440.2R-17 reasonably estimated the moment capacity of both mid-span and middle support sections. Conversely, the available theoretical deflection models underestimated the deflection of hybrid reinforced concrete T-beams at all load stages

A numerical analysis of buckle cable force of concrete arch bridge based on stress balance method

Abstract It is difficult to calculate the buckle cable force for the cantilever casting concrete arch bridge. Relying on the 180 m-span Jiming Sansheng Bridge, this paper put forward one method to calculate the initial buckle cable force based on the stress balance method. Firstly, the stress balance equation considering only tensile stress was derived for the first time, and the feasible region of the initial cable force was calculated by the allowable tensile stress of the arch rib, which improved the original stress balance method. Then, using the influence matrix, the initial buckle cable force was optimized by reducing the allowable tensile stress of concrete in stages, and finally the optimal initial cable force was obtained. The practical engineering results show that it is feasible to calculate the initial buckle force. The maximum tensile stress of concrete arch during the cantilever casting process is 1.52 MPa, meeting the specification requirements. The deviation between the calculated and measured stress is less than 12%. The calculated cable force agrees with the measured cable force, and the deviation is less than 2%. The initial cable force is only tensioned once, improving work efficiency. The method and experience of this paper can provide a reference for the arch bridge constructed by cantilever casting

Regional Disparities in Emissions of Rural Household Energy Consumption: A Case Study of Northwest China

The purpose of this paper is to present the emissions status of multiple rural areas from the perspective of a field survey and make up for the defects of the traditional emission cognition of single type of area. The basic data in the lower reaches of the Weihe River of Northwest China were collected through household questionnaire surveys, and emissions from rural household energy consumption were calculated in the paper. In addition, the grey relational analysis method was used to identify influential factors of emission disparities. The results show that the total emissions of the plain, loess tableland, and Qinling piedmont areas are 1863.20, 1850.43, and 2556.68 kg, respectively. Regional disparities in emissions of rural household energy consumption vary greatly. CO2 emissions are highest in the Qinling piedmont area, followed by the loess tableland area. For other emissions, there is no fixed order of the three areas, which suggests that disparities in emissions are connected with the dominant type of energy consumption. Diversification of energy use might not necessarily produce higher emissions, but the traditional biomass energy pattern does generate more emissions. The regional supply capacity of household energy is the original influence factor of disparities in emissions, and factors that influence these disparities are directly related to differences among farmers, followed by the age structure, educational background, income level, occupation, and so on

Linear Control Method for Arch Ring of Oblique-Stayed Buckle Cantilever Pouring Reinforced Concrete Arch Bridge

Yelang Lake Bridge is the largest cantilevered single-chamber reinforced concrete arch bridge in China, with a net span of 210 m. In this article, an equation for positioning the height of the formwork before pouring of the arch ring segment was derived, which was suitable for the construction control of the long-span reinforced concrete arch bridge such as the Yelang Lake Bridge. The arch ring segment elevation calculation equation was derived under the two typical working conditions that the concrete pouring of the arch ring segment is completed and the buckle cable and anchor cable tensioning are completed. In addition, two typical working conditions of arch ring segment concrete pouring and cable tensioning were evaluated. Then, a new type of cradle and loading test of the cradle, which meet the requirements of the long segment pouring of the arch ring, were introduced. Finally, the measurement deviation during the construction of the arch segment was analyzed. The linear control results of the arch ring showed that the arch ring segment elevation calculation formula could effectively ensure the accuracy of the arch ring segment construction process under the two typical conditions of completion of concrete pouring of the arch ring segment and completion of the buckle and anchor cable tensioning. The maximum deviation is only 3.1 mm. The line shape after the completion of the arch ring construction was in good agreement with the target line shape, and the deviation between the measured value and the target value was only 2.5 cm, which met the engineering requirements

Research on the Method of Predicting Corrosion width of Cables Based on the Spontaneous Magnetic Flux Leakage

The detection of cable corrosion is of great significance to the evaluation of cable safety performance. Based on the principle of spontaneous magnetic flux leakage (SMFL), a new method for predicting the corrosion width of cables is proposed. In this paper, in order to quantify the width of corrosion, the parameter about intersecting point distance between curves of magnetic flux component of x direction at different lift off heights (Dx) is proposed by establishing the theoretical model of the magnetic dipole of the rectangular corrosion defect. The MATLAB software was used to analyze the influencing factors of Dx. The results indicate that there exists an obvious linear relationship between the Dx and the y (lift off height), and the Dx–y curves converge to near the true corrosion width when y = 0. The 1/4 and 3/4 quantiles of the Dx–y image were used for linear fitting, which the intercept of the fitting equation was used to represent the predicted corrosion width. After the experimental study on the corrosion width detection for the parallel steel wire and steel strand, it is found that this method can effectively improve the detection accuracy, which plays an important role in cable safety assessment

Effect of fermented soybean meal supplementation on some growth performance, blood chemical parameters, and fecal microflora of finishing pigs

This study evaluated the effect of fermented soybean meal (FSBM) supplementation on growth performance, meat quality, blood biochemical parameters, and fecal microflora of finishing pigs. Thirty-two crossbred pigs (Duroc × Landrance × Yorkshire) (66-day-old, 67.95±0.25 kg) were randomly allocated to two treatments and fed diets containing soybean meal and FSBM. The average daily gain (ADG), average daily feed intake (ADFI), feed conversion ratio (FCR), blood biochemical parameters, and meat quality index were measured. At the end of experiment, the fecal microflora of finishing pigs was analyzed with 16S rDNA techniques. Results revealed that pigs fed FSBM had a greater ADG and lower cooking loss relative to control group (basal diets). Compared with the control group, the triglyceride content in the serum of the group fed FSBM increased significantly, and the creatinine content in the serum decreased notably. Fermented soybean meal enhanced the abundance of Bacteroidetes, Prevotellaceae, Bcteroidales, Bacteroidia, but inhibited the growth of Firmicutes, Clostridia, Clostridiales, and Ruminococcaceae in the intestine of pigs. Therefore, we can speculate that FSBM may play an important role in animal production. Dietary FSBM supplementation may be beneficial to some aspects of growth performance and the diversity of fecal microflora in finishing pig

An aqueous magnesium-ion hybrid supercapacitor operated at −50 °C

The recent advances in aqueous magnesium-ion hybrid supercapacitor (MHSC) have attracted great attention as it brings together the benefits of high energy density, high power density, and synchronously addresses cost and safety issues. However, the freeze of aqueous electrolytes discourages aqueous MHSC from operating at low-temperature conditions. Here, a low-concentration aqueous solution of 4 mol L−1 Mg(ClO4)2 is devised for its low freezing point (−67 °C) and ultra-high ionic conductivity (3.37 mS cm−1 at −50 °C). Both physical characterizations and computational simulations revealed that the Mg(ClO4)2 can effectively disrupt the original hydrogen bond network among water molecules via transmuting the electrolyte structure, thus yielding a low freezing point. Thus, the Mg(ClO4)2 electrolytes endue aqueous MHSC with a wider temperature operation range (−50 °C–25 °C) and a higher energy density of 103.9 Wh kg−1 at 3.68 kW kg−1 over commonly used magnesium salts (i.e., MgSO4 and Mg(NO3)2) electrolytes. Furthermore, a quasi-solid-state MHSC based on polyacrylamide-based hydrogel electrolyte holds superior low-temperature performance, excellent flexibility, and high safety. This work pioneers a convenient, cheap, and eco-friendly tactic to procure low-temperature aqueous magnesium-ion energy storage device

A propensity-score matched comparison of perioperative and early renal functional outcomes of robotic versus open partial nephrectomy.

OBJECTIVES: To compare the perioperative and early renal functional outcomes of RPN with OPN for kidney tumors. MATERIALS AND METHODS: A total of 209 RPN or OPN patients with availability of preoperative cross-sectional imaging since 2009 at our center were included. To adjust for potential baseline confounders propensity-score matching was performed, which resulted in 94 OPNs matched to 51 RPNs. Perioperative and early renal functional outcomes were compared. RESULTS: In propensity-score matched analysis, RPN procedures were well tolerated and resulted in significant decreases in postoperative analgesic time (24 vs. 48 hr, p<0.001) and visual analog pain scale (3 vs. 4, p<0.001). Besides, the RPN patients had a significantly shorter LOS (9 vs. 11 days, p = 0.008) and less EBL (100 vs. 200 ml, p<0.001), but median operative time was significantly longer (229 vs. 182 min, p<0.001). Ischemia time, transfusion rates, complication rates, percentage eGFR decline and CKD upstaging were equivalent after RPN versus OPN. In multivariable logistic regression analysis, RPN patients were less likely to have a prolonged LOS (odds ratio [OR]: 0.409; p = 0.016), while more likely to experience a longer operative time (OR: 4.296; p = 0.001). However, the statistical significance for the protective effect of RPN versus OPN in EBL was not confirmed by examining the risk of EBL≥400 ml (OR: 0.488; p = 0.212). CONCLUSIONS: When adjusted for potential selection biases, RPN offers comparable perioperative and early renal functional outcomes to those of OPN, with the added advantage of improved postoperative pain control and a shorter LOS

Robotic versus Open Partial Nephrectomy: A Systematic Review and Meta-Analysis

<div><p>Objectives</p><p>To critically review the currently available evidence of studies comparing robotic partial nephrectomy (RPN) and open partial nephrectomy (OPN).</p><p>Materials and Methods</p><p>A comprehensive review of the literature from Pubmed, Web of Science and Scopus was performed in October 2013. All relevant studies comparing RPN with OPN were included for further screening. A cumulative meta-analysis of all comparative studies was performed and publication bias was assessed by a funnel plot.</p><p>Results</p><p>Eight studies were included for the analysis, including a total of 3418 patients (757 patients in the robotic group and 2661 patients in the open group). Although RPN procedures had a longer operative time (weighted mean difference [WMD]: 40.89; 95% confidence interval [CI], 14.39–67.40; p = 0.002), patients in this group benefited from a lower perioperative complication rate (19.3% for RPN and 29.5% for OPN; odds ratio [OR]: 0.53; 95%CI, 0.42–0.67; p<0.00001), shorter hospital stay (WMD: −2.78; 95%CI, −3.36 to −1.92; p<0.00001), less estimated blood loss(WMD: −106.83; 95%CI, −176.4 to −37.27; p = 0.003). Transfusions, conversion to radical nephrectomy, ischemia time and estimated GFR change, margin status, and overall cost were comparable between the two techniques. The main limitation of the present meta-analysis is the non-randomization of all included studies.</p><p>Conclusions</p><p>RPN appears to be an efficient alternative to OPN with the advantages of a lower rate of perioperative complications, shorter length of hospital stay and less blood loss. Nevertheless, high quality prospective randomized studies with longer follow-up period are needed to confirm these findings.</p></div