Suckling behavior of calves in seasonally calving pasture-based dairy systems,and possible environmental and management factors affecting suckling behaviors

In recent years, interest has been increasing in whether farmed animals are able to live a reasonably natural life, with one particular area of concern being calf-dam separation. The objectives of this study were to monitor the timing and frequency of suckling behavior of calves left on pasture to suckle their dams for up to 24 h (interquartile range 4.0–15.5 h) and to investigate possible risk factors that may contribute to any variability seen. Over 2 yr, a convenience sample of 8 farms (4 in the North Island, 4 in the South Island of New Zealand) were involved in an observational study where cows and calves were observed for 24 h a day over a 2-wk-long period per farm. During the observation period, farmers continued to remove calves at the same frequency they normally did (which ranged from once a day to 4 times a day). Cows (between 2 and 12 yr old) and calves were observed from a scissor lift in or beside the calving paddock. Cows had numbers written on them, and observers used binoculars and spotlights. Observers recorded the length of stage 2 labor, time of birth, standing, and first suckling, number of suckling events, time of calf removal from the dam, temperature where the cows were grazing, and size of the grazing area they were calving in. Dams were body condition scored before calving, and their age was extracted from farm records. A total of 697 calves were observed during the study. A total of 444 of 697 calves [63.7%; 95% confidence interval (CI) = 60.0–67.3%] suckled in the calving paddock (farm range 40.0% to 90.2%). Of the 444 calves that suckled in the calving paddock, 407 (58.4%; 95% CI 54.6–62.1%) suckled within the first 6 h after birth (farm range 33.0% to 83.6%). Individual risk factors associated with the hazard rate ratio (HR) for time to first suckling event were time to standing (calves who took more than 1.3 h to stand had a longer time from birth to first suckle) and age of the dam [compared with calves that were born from dams >7 years of age, calves born to dams that were 2–3 and 4–7 yr of age had a 1.49 (95% CI 1.07–2.06) and 1.19 (95% CI 0.89–1.60) HR, respectively, for time from birth to first suckle in the calving paddock]. Farm risk factors associated with the HR of suckling were frequency of calf collection [calves that were born on farms that collected calves once a day suckled earlier than calves on farms that removed calves more than once a day (HR 1.52; 95% CI 1.25–1.84)] and temperature [a minimum temperature of <10°C within 6 h of a calf being born was associated with a 0.69 (95% CI 0.53–0.89) hazard of suckling in the calving paddock]. We observed very large farm variability that urgently requires further investigation if pasture-based farms are ever to adopt a system where calves remain with their dams for longer than 24 h.     

Dam effects on bedload transport on the upper Santa Ana River,California, and implications for native fish habitat

Dams disrupt the flow of water and sediment and thus have the potential to affect the downstream geomorphic characteristics of a river. Though there are some well‐known and common geomorphic responses to dams, such as bed armouring, the response downstream from any particular dam is dependent on local conditions. Herein, we investigate the response of the upper Santa Ana River in southern California, USA, to the construction of a large dam at the transition from mountains to valley, using calculations of bedload transport capacity on the mainstem below the dam and for major tributaries. Approximate sediment budgets were constructed for downstream reaches to estimate deposition and erosion rates for sand, gravel, and cobble particle sizes. Our results indicate that the classical response of bed armouring and erosion is likely limited to a short reach immediately below the dam. Farther downstream, though transport capacity is reduced by flow regulation by the dam, the channel reaches are likely to remain depositional but with reduced deposition rates. Persistent deposition, as opposed to erosion, is the result of the replenishment of flow and sediment supply by large downstream tributaries. In addition, the calculations indicate that the composition of the bed is unlikely to change substantially in downstream reaches. A Monte Carlo approach was employed to estimate the uncertainty in the sediment budget predictions. The impacts of the dam on the geomorphic character of the river downstream could have implications for native fish that rely on coarse substrate that supports their food base.     

考虑应力场与渗流场耦合的尾矿坝非稳定渗流分析

根据尾矿坝形成的特点，进行考虑应力场与渗流场耦合的非稳定渗流分析。根据弹性力学和渗流理论提出了耦合问题的力学模型及其控制微分方程，然后导出这一问题的有限元计算公式及相应程序。在计算中首次导出了尾矿坝的渗透系数与应力场的关系式，并进行尾矿坝的非稳定渗流分析。工程实例计算结果表明，考虑耦合作用的影响，尾矿坝渗流场的总渗流量减小，而应力场的各应力分量的最大值增大。     

混凝土面板堆石坝接缝止水的实验和分析

混凝土面板堆石坝周边缝止水的损坏是其漏水的主要原因。针对工程实用形式的周边缝铜止水和ＰＶＣ止水，首次进行了承受错位变形的破坏实验，揭示了止水极限变形能力和开裂规律，提出了接缝止水的计算模型、设计准则及提高铜止水极限抗裂能力的工程措施。     

尾矿库排渗系统反滤设计研究进展

水平排渗管、辐射井为当前典型的尾矿库排渗系统，无纺土工布为排渗管（辐射管）主要反滤材料，但其反滤层缺乏严格的反滤设计，反滤特性差异较大。通过总结典型反滤层结构及各组成部分对反滤性能的影响、现有反滤准则及反滤试验技术、反滤层耐久性研究进展，总结了尾矿料统计特征、土工布特征参数、土工布反滤层反滤过程等方面的研究进展，指出了尾矿库排渗系统反滤设计领域今后的几个研究方向：尾矿料物理力学特性对反滤层的影响研究，土工布特征表征方法研究，土工布特征参数测量方法研究，长期反滤试验方法与试验设备研究，土工布反滤层反滤过程数值研究，为尾矿库排渗系统反滤设计研究提供参考。     

A hybrid approach based on an improved gravitational search algorithm and orthogonal crossover for optimal shape design of concrete gravity dams

A hybrid approach based on an improved gravitational search algorithm (IGSA) and orthogonal crossover (OC) is proposed to efficiently find the optimal shape of concrete gravity dams. The proposed hybrid approach is called IGSA-OC. The hybrid of IGSA and the OC operator can improve the global exploration ability of the IGSA method, and increase its convergence rate. To find the optimal shape of concrete gravity dams, the interaction effects of dam–water–foundation rock subjected to earthquake loading are considered in this study. The computational cost of the optimal shape of concrete gravity dams subjected earthquake loads is usually high. Due to this problem, the weighted least squares support vector machine (WLS-SVM) regression as an efficient metamodel is utilized to considerably predict dynamic responses of gravity dams by spending low computational cost. To testify the robustness and efficiency of the proposed IGSA-OC, first, four well-known benchmark functions in literatures are optimized using the proposed IGSA-OC, and provides comparisons with the standard gravitational search algorithm (GSA) and the other modified GSA methods. Then, the optimal shape of concrete gravity dams is found using IGSA-OC. The solutions obtained by the IGSA-OC are compared with those of the standard GSA, IGSA and particle swarm optimization (PSO). The numerical results demonstrate that the proposed IGSA-OC significantly outperforms the standard GSA, IGSA and PSO.     

Applying Optimal Control Model to Dynamic Equipment Allocation Problem: Case Study of Concrete-Faced Rockfill Dam Construction Project

This paper presents an optimization method for solving a dynamic equipment allocation problem (DEAP) encountered during the implementation of a concrete-faced rockfill dam construction project. In contrast to prior studies, the uncertainties associated with equipment failures have been explicitly considered in the objective function of our mathematical model that maximizes construction throughput. Specifically, our research assumes that the equipment failure time is characterized by a Weibull distribution, which has been justified by a chi-square goodness-of-fit test. A failure probability–work time equation is also used to characterize the relationship between the equipment failure probability and mean time to work. Furthermore, our model considers multiple types of equipment, and each is capable of doing different jobs. The model is confined by the relationship equations, initial conditions, and constraint conditions. Then, the particle swarm optimization (PSO) technique is applied to search for the optimal solution of the DEAP. Finally, the Shuibuya Hydropower Project was used as a real-world example to demonstrate the practicality and efficiency of the optimization method.     

江西省水库大坝注册登记管理的实践及其思考

水库大坝注册登记工作是对水库安全监管的重要措施，制定明确的注册实施方案和工作要求，规定注册登记的范围、职责分工、工作程序、时间要求和工作方法，强调各级水行政主管部门对各水库大坝注册登记信息审核，保障了江西省水库大坝注册登记工作顺利进行，达到了水库大坝安全监管工作科学规范化管理的目的。     

Hydropower for sustainable water and energy development

Turkey has a total gross hydropower potential of 433 GWh/year, but only 125 GWh/year of the total hydroelectric potential of Turkey can be economically used. By the commissioning of new hydropower plants, which are under construction, 36% of the economically usable potential of the country would be tapped. Turkey presently has considerable renewable energy sources. The most important renewable sources are hydropower, biomass, geothermal, solar and wind. Turkey's geographical location has several advantages for extensive use of most of these renewable energy sources. Over the last two decades, global electricity production has more than doubled and electricity demand is rising rapidly around the world as economic development spreads to emerging economies. Not only has electricity demand increased significantly, it is the fastest growing end-use of energy. Therefore, technical, economic and environmental benefits of hydroelectric power make it an important contributor to the future world energy mix, particularly in the developing countries.