Septic tank and agricultural non‐point source pollution within a rural watershed

This investigation addresses the problem of Non‐Point Source (NPS) pollution in the rural Lake Weatherford watershed in Parker County, Texas. This reservoir is the primary municipal water supply for the City of Weatherford, Texas. The principal method of wastewater disposal is the on‐site system or septic tanks for the small residential areas surrounding the reservoir.

Sources of NPS pollution of interest in this watershed include agricultural operations as well as the residential areas. These sites were identified with the aid of aerial photography and field investigation. Suspected NPS problems were substantiated through a sampling program involving chemical and biological testing of the reservoir. Results indicate that there is significant NPS pollution contamination of Lake Weatherford from agricultural sources and seepage from on‐site wastewater disposal systems. Excessive fecal coliform and fecal streptococcus counts (>500 bacteria/100 ml) were generally associated with rainfall events and several samples showed values > 100000 bacteria/100 ml. The fecal coliform/fecal streptococcus ratios indicated contamination from human sources, animal sources, and a combination of both. Nutrient concentrations fluctuated from quite low to high with ammonia as the most consistent problem. High ammonia values were also associated with rainfall events.     

Shake table study of annular baffles in steel storage tanks as sloshing dependent variable dampers

Aboveground steel storage tanks are widely utilized in industrial areas such as oil refineries, petrochemical complexes, oil depots, and etc. Assurance of these infrastructure facilities in high seismic areas is a very important engineering consideration. High amplitude fluid sloshing is one of the widespread causes of steel oil storage tanks during strong earthquakes addressed as an important failure mode. This phenomenon generates additional forces impacting the wall and roof of the tanks. Annular baffles can be used as slosh damping devises to control liquid sloshing within a tank. The main objective of this paper is experimental study of annular baffle effects as anti-sloshing damping devices to reduce fluid wave sloshing height in steel storage tanks typically used in oil and petrochemical complexes during an earthquake. Shake table tests have been used on a reduced scale model steel storage tank in two cases of with and without annular baffles. Three real earthquake ground motion records are used as input base motion. Based on the experimental test results, dynamic characteristics of studied tank models with different filling levels and different baffle dimensions and arrangements have been obtained and summarized in this paper. Also, sloshing heights and convective mode damping values are determined from the test results and compared with API650 code recommendations and recommended equations by other researchers. Generally, the results of this study indicate significant effects of the annular baffles in reducing the fluid wave sloshing height as sloshing dependent variable dampers.     

液化石油气储运容器不同受热条件下的温度压力的估算

提出了液化石油气储运容器在不同受热条件下,容器内的温度和压力的简化的计算方法,可用于此类火灾原因的分析认定、安全分析等,对火灾的扑救也具有十分重要的意义。     

Statistical approach for evaluating the significance of generating new data to the management of the brackish groundwater fields in Kuwait

The brackish groundwater production fields in Kuwait have been drilled intensively during the past three decades. However, poor spatial distribution of some of the measured parameters and limited measurements of others are forcing extended extrapolation during numerical simulations of management schemes. On the other hand, operational, time and budget constraints allow only limited additional field-generated data, raising the question of the significance of their impact on numerical modeling results. This study evaluates this significance by using nearest neighbor statistics and a synthesized data set to assess the impacts of a proposed field investigation on the spatial distribution and kriged values of transmissivity and storage coefficient arrays of the brackish groundwater production fields. A scale for the significance of the impacts was prepared based on the sensitivity of the aquifer system towards the studied properties. The transmissivity data array indicated a 25% reduction in the maximum distance and an 8% increase in the interquartile of the nearest neighbor analysis. The storage coefficient data arrays indicated the extension of the covered area to reach the southern boundary of the study area, which was reflected in more than doubling the maximum distance between the nearest neighbors. For the kriged values of the transmissivity, about 35% of the study area was significantly changed due to the addition of the new data points, while only 10% of the study area was significantly changed for the storage coefficient values. Overall, while the spatial distribution indicators were not conclusive, the significance of the new data was clear in the changes in the kriged values of the aquifer properties. Additionally, this approach highlights the aquifer test locations where the generated data had no impact on the kriged values, which may be utilized for optimizing the allocation and number of the aquifer tests.     

大型石油储罐消防设计研究

根据我国大型储罐设置的特点,分析了大型石油储罐在储存、转运过程中潜在的火灾危险。通过对千例石油火灾案例统计分析,获得了石油储罐发生火灾的主要原因。在此基础上,从石油储罐工艺设计、布局、防火和灭火等角度出发,分析大型石油储罐常用的类型、材料和防腐处理技术;研究储罐的布置间距;总结大型储罐消防设计中采用的防、灭火技术措施。论文研究的成果,可供实践工程参考。     

调蓄池在区域水系生态治理中的应用

在串湖流域黑臭水体污染治理过程中,调蓄池起到了合流污水截流及初期雨水面源污染控制的作用。本工程根据汇水分区的划分,共设置11座调蓄池,总调蓄容积为130500m^3。调蓄池的设置可最大限度地消减排入河道的污染物,同时对于控制初期雨水带来的面源污染至关重要。     

基于Abaqus软件的并行计算集群平台构建与优化方法

根据有限元显式算法和隐式算法的特点,研究了岩土工程动力分析并行计算集群系统的硬件要求、集群系统的构建方法,构建了基于EM64T硬件构架、双路Intel Xeon处理器、Linux操作系统和64位Abaqus软件的32CPU并行计算集群平台,测试了存储子系统对集群性能的影响,比较了两种千兆以太网络作为集群子网络的性能优化方法。以地下结构的地震反应分析为例,测试了优化前后该集群系统的计算速度,发现两种以太网络性能优化方法都可以有效提高集群计算速度。列举了该集群系统在深水桥梁基础流固耦合动力分析、地下结构地震反应分析和快速轨道交通环境振动分析中的应用,显示了该集群在显式算法、隐式算法及小规模、大规模数值计算问题中的并行计算效率,证明所构建的Abaqus数值模拟并行计算集群平台能够满足计算规模、计算精度和时效性的要求。     

稠油罐底泥碳化处理技术研究与应用*

为解决油田生产过程中产生的稠油罐底泥的环境污染和资源浪费问题,在分析含油污泥性质和特点的基础上开发了稠油罐底泥碳化处理工艺及配套装置。介绍了该技术的原理及工艺流程,在小试、中试研究的基础上,进行了工业化应用,稠油罐底泥的处理效果表明:油气回收率可达90%以上,轻质油品占回收油总量的78%以上,焚烧处理后的残渣未检出矿物油;烟气和废水相关项目的监测值符合相关标准。     

Multi-hazard failure assessment of atmospheric storage tanks during hurricanes

Hurricane as one of the most destructive natural hazards can make a devastating impact on the industrial equipment, especially atmospheric storage tanks, leading to the release of stored chemicals and disastrous safety and environmental issues. These catastrophic consequences are caused not only by strong winds but also by the torrential rainfall and inundating floods. The objective of this study is to present a risk-based methodology for assessing and reducing the vulnerability of atmospheric storage tanks to hurricanes. Considering the shell buckling, flotation, sliding, and roof sinking as dominant failure modes of atmospheric storage tanks during hurricanes, Bayesian network (BN) has been employed to combine the failure modes while considering their conditional dependencies. The probability updating feature of the developed BN was employed to indicate that the flood is the most critical hazard during hurricanes while the impact of wind and rainfall cannot be neglected. Extending the developed BN to an influence diagram, the cost-benefit filling of storage tanks with water prior to the advent of hurricanes was shown as a viable measure for reducing the damage probability. The results show that the proposed methodology can be used as an effective decision support tool for assessing and reducing the vulnerability of atmospheric storage tanks to natural hazards.     

基于Tanks 4.0.9d模型的石化储罐VOCs排放定量方法研究

石化储罐VOCs排放是石化行业重要的VOCs排放源之一.为了掌握石化储罐VOCs的排放情况,研究了基于Tanks4.0.9d模型计算各种类型储罐VOCs排放量的方法,并对卧式固定顶罐、立式固定顶罐、内浮顶罐和外浮顶罐的VOCs排放量进行了实例计算.同时,探讨了在国内使用Tanks 4.0.9d模型时需要考虑的所在地气象数据、储罐密封情况、储存物质的参数选择及参数单位换算问题.Tanks 4.0.9d模型可以作为一种方便且准确性较高的石化储罐VOCs排放定量方法在国内推广使用.