Hydraulic reactivity and cement formation of baghdadite

In this study, the hydraulic reactivity and cement formation of baghdadite (Ca₃ZrSi₂O₉) was investigated. The material was synthesized by sintering a mixture of CaCO₃, SiO₂, and ZrO₂ and then mechanically activated using a planetary mill. This leads to a decrease in particle and crystallite size and a partial amorphization of baghdadite as shown by X-ray powder diffraction (XRD) and laser diffraction measurements. Baghdadite cements were formed by the addition of water at a powder to liquid ratio of 2.0 g/ml. Maximum compressive strengths were found to be ~2 MPa after 3-day setting for a 24-h ground material. Inductively coupled plasma mass spectrometry (ICP-MS) measurements showed an incongruent dissolution profile of set cements with a preferred dissolution of calcium and only marginal release of zirconium ions. Cement formation occurs under alkaline conditions, whereas the unground raw powder leads to a pH of 11.9 during setting, while prolonged grinding increased pH values to approximately 12.3.     

An economic investigation of the wind-hydrogen projects: A case study

Hydrogen as an energy carrier can play a significant role in reducing environmental emissions if it is produced from renewable energy resources. This research aims to assess hydrogen production from wind energy considering environmental, economic, and technical aspect for the East Azerbaijan province of Iran. The economic assessment is performed by calculation of payback period, levelized cost of hydrogen, and levelized cost of electricity. Since uncertainty in the power output of wind turbines may affect the payback period, all calculations are performed for four different turbine degradation rates. While it is common in the literature to choose the wind turbine based on a single criterion, this study implements Multi-Criteria Decision-Making (MCDM) techniques for this purpose. The results of Step-wise Weight Assessment Ratio Analysis illustrates that economic issue is the most important criterion for this research. The results of Weighted Aggregated Sum Product Assessment shows that Vestas V52 is the most suitable wind turbine for Ahar and Sarab cities, while Eovent EVA120 H-Darrieus is a better choice for other stations. The most suitable location for wind power generation is found to be Ahar, where it is estimated to annually generate 2914.8 kWh of electricity at the price of 0.045 $/kWh, and 47.2 tons of hydrogen at the price of 1.38 $/kg, which result in 583 tons of CO₂ emission reduction.     

构皮滩水电站泄洪洞优化设计

构皮滩水电站为满足2008年12月工程提前发电的需要,结合现有泄洪洞地质情况和施工情况对泄洪洞布置进行了专题研究,结果表明利用降低进口高程为550 m的泄洪洞和坝身放空底孔联合参与后期导流,可缓解2007年导流隧洞下闸封堵后大坝在2008年汛期施工的压力,为大坝施工增加了2个月左右的工期。     

非稳定井流模型的半解析解

为了提高非稳定渗流计算的计算精度 ,通过数学分析得到了水位传导系数随时间变化时 ,一类非稳定渗流井流模型的半解析解 ,并进行了计算比较     

液力联轴器喷油着火事故的原因分析及预防

以矿用液力联轴器为研究对象 ,阐明其喷油着火的机理 ,分析其喷油着火的原因并作出事故树分析 ,针对现场使用的情况 ,提出预防措施及发展趋势 ,对矿井安全生产具有指导性作用。     

飞机液压系统污染及控制

本文全面分析了收音机液压系统污染的危害和主要原因，并在此基础上有针对性地提出了预防措施。     

对编写《水轮机》新教材的建议

提出适应新的中等职业《水轮机》教材和课程教学大纲的修改建议。     

液压支柱表面镀层改进之探讨

通过比较电镀硬铬和化学镀镍在液压支柱表面处理上的应用 ,探讨了化学镀镍在配方、工艺、设备、镀层性能、环保等方面的优越性。     

液压集成块校核软件的编制和应用

本文叙述了液压集成块校核软件的编制思想和方法，并重点介绍了编制过程中所使用的相关技术，同时给出部分源程序。     

纤维混凝土在水工建筑工程中的应用(上)

概述改性混凝土垢发展情况，介绍纤维混凝土在国内外水工建筑物上的应用实例，提出钢纤维增强钢筋混凝土水工建筑结构强度计算方法。包括受弯构件正截面强度，斜截面抗剪强度的计算；重点介绍了网状钢纤维增强混凝土（FOC）在水工建筑物上的应用，包括在渡槽，闸门，小型拦河坝，轻型岸型等工程上的应用实例，T新梁正斜截面的强度计算，板材承载力计算的方法。