Reduced removal of bacteriophage MS2 in during basin infiltration managed aquifer recharge as basin sand is exposed to infiltration water

Basin infiltration managed aquifer recharge (MAR) is a commonly used method for storing and treating surface water to be used as drinking water. This study examined how the removal of bacteriophage MS2 was affected by the relative age of the sand used for basin infiltration MAR at 4 °C using batch experiments (static and agitated) and column experiments. The sand and the water used in all experiments were characteristic of that used at a basin infiltration MAR scheme in Uppsala, Sweden. Experimental data was fit with numerical models describing the fate and transport of virus in soil—water systems. The “used” sand that had been subjected to intermittent infiltration over a period of 8 years had 15 times the amount of organic carbon than the “new” sand, which had yet to be used for infiltration. Results showed that attachment of MS2 to the new sand in batch experiments was relatively irreversible. Attachment to the used sand was reversible. Inactivation of MS2 was slowed when it was attached to the used sand. Results for the column experiments showed that the removal rate of MS2 was significantly lower in columns of used sand than in columns of new sand. Simulations indicated that MS2 would be entirely removed in the infiltration basins with new sand. Less than 3 log removals was estimated for basins with used sand. Reduced removal of MS2 by the used sand was deemed to be most likely due to organic coatings on the used sand. Results of this study give deeper insight into the mechanisms responsible for removing virus in infiltration basins and how those mechanisms will change as the sand in the basin is exposed to infiltration water.     

基于高阶局部模态的弹性地基上框架结构物理参数识别研究

利用框架结构的整体振动模态信息进行局部损伤的判别具有明显的局限性。高阶模态逐渐被人们认识并用来进行局部物理参数识别并用来进行损伤判别。本文以弹性地基上独立基础的框架结构底层柱为研究对象,利用增加的质量块对柱子进行局部损伤的制造,利用脉冲锤击法和激振器扫频实验进行高阶模态对比测试,利用PolyMAX模态分析方法进行损伤前后高阶模态的识别,发现了“高灵敏度高阶模态”的存在。最后通过两端约束Euler梁的计算模型,通过高阶模态来识别物理参数以及地基参数,其中物理参数结果具有较好的可靠性。     

评价漓江健康的RIVPACS预测模型研究

RIVPACS类河流健康评价模型是广泛应用的河流健康评价工具.利用漓江流域48个样点的底栖动物和环境数据,按照建立RIVPACS模型的方法和步骤,开展预测模型试点研究.48个样点中有32个参照样点,随机选取其中27个用于模型构建.余下的5个参照样点、10个轻至中度干扰样点和6个严重干扰样点用于模型验证.首先通过Bray...     

Analysis of objective functions used in urban runoff models

The objective functions used in parameter estimation in urban runoff models are compared by using a method proposed by Diskin and Simon¹ and the urban runoff model ILLUDAS. Two sets of objective functions, the first one used by Diskin and Simon in their study and a second one which includes other objective functions are used. Rainfall-runoff data from urban watersheds in the US are used in the study. The results indicate that the least squares criterion is the best among those studied.     

导线线圈的射线层析检测

本文选用不同的方法对两个导线线圈进行了射线检测,主要采用透射式工业CT检测和康普顿背散射成像检测两种射线层析检测方法,有效检测了导线线圈内部的缺陷隋况,并指出射线层析检测作为一项新技术和新手段,可充分应用在航天产品的无损检测中。     

基于谱分解的断层自动识别

本文在总结国内外地震勘探解释系统的基础上,以物理地震学为理论基础,利用谱分解、地震信号处理中的偏移技术、模式识别中的分级聚类算法和最小二乘法,提出了自动提取断棱衍射、识别断层的思想.仿真结果表明该思想和方法是可行的.本方法还可用于岩性地球物理勘探.     

平衡剖面技术在国内外油气勘探中的最新应用

平衡剖面技术是油气勘探中的一项辅助解释技术,它提供正演与反演两种模拟过程.正演模拟过程可以迅速、有效地检验某种地质假设,为解释人员提供合理的解释模型,同时,正演过程可以动态显示构造变形历史,为研究油气藏的形成、演化提供依据;而反演模拟过程则可以迅速地对剖面解释结果进行合理性检验,避免解释中的随意性,提高剖面解释的质量和效率.本文对平衡剖面有关的概念、原理、应用条件及变形机制等进行了系统归纳与总结,并详细介绍了国内外平衡剖面技术在油气勘探中的最新应用实例.     

地磁场等变线在地磁预报地震中的应用

在地磁绝对观测预报地震中，若充分利用地磁场一般具有规则的等变线分布这一特征，可以使原来仅限于小台距的预报法推广到大台距，并在实践中获得了较理想的结果。这样，解决了台站稀少地区台站观测资料难以用于地震预报的难题，为地磁绝对预测预报地震找到了一种新的途径。     

基于FPGA及DSP的测井遥传信号解码技术

综合化测井数据采集系统的硬件设计采用了可靠性较高的compactPCI总线结构以及FPGA、DSP等技术,软件采用了实时操作系统VxWorks．利用FPGA和DSP技术实现了测井遥传信号的解码,保证了系统的实时性和可靠性能够满足测井采集的要求．系统已在现场应用,验证了设计方案可行的．     

Interpretation of the behaviour of agrowell systems in Sri Lanka using radial flow models

Abstract

This paper describes a study of the use of large diameter “agrowells” used for irrigation in Sri Lanka. Detailed field information for a single location is presented and a numerical radial flow model was used to interpret the field response. Initially the model was used to represent a pumping test in which the pumping and subsequent recovery were monitored. It was then used to investigate the operation of the well during a dry season. Satisfactory agreement could only be obtained when account was taken of the withdrawal of water from below the water table by trees. From the simulation it was possible to show that skilful farming practice could be used in steadily exploiting the resources for irrigation over the whole of the dry season.     

基于能量原理的钢筋混凝土简体结构抗震性能研究

本文通过能量法研究了钢筋混凝土简体结构的抗震性能。文中采用振型分解法按等效单自由度体系求解简体结构的滞回输入能;用pushover法分析了滞回耗能在结构层间的分布规律及结构自身的耗能能力;根据楼层滞回耗能与弹塑性层间位移的关系求出了薄弱层的弹塑性位移。对一高层钢筋混凝土框架-简体结构在7度罕遇地震下的抗震性能进行了评估,通过与非线性动力时程分析的对比,证明了方法的可行性。     

基于能量原理的钢筋混凝土筒体结构抗震性能研究

本文通过能量法研究了钢筋混凝土筒体结构的抗震性能。文中采用振型分解法按等效单自由度体系求解筒体结构的滞回输入能;用pushover法分析了滞回耗能在结构层间的分布规律及结构自身的耗能能力;根据楼层滞回耗能与弹塑性层间位移的关系求出了薄弱层的弹塑性位移。对一高层钢筋混凝土框架-筒体结构在7度罕遇地震下的抗震性能进行了评估,通过与非线性动力时程分析的对比,证明了方法的可行性。     

The use of the Akaike Information Criterion in the identification of an optimum flood frequency model

Abstract

For a long time now, the hydrologist has been faced with the problem of finding which of the many possible probability distribution functions can be used most effectively in flood frequency analyses. This problem has been mainly due to the insufficiency of the conventional goodness-of-fit procedures when used with the typically skewed flood probability distributions. In this study, the Akaike Information Criterion (AIC) goodness-of-fit test is used to identify more objectively the optimum model for flood frequency analysis in Kenya from a class of competing models. The class is comprised of (a) seven three-parameter density functions, namely, log-normal, Pearson, log-Pearson, Fisher-Tippet, log-Fisher-Tippet, Walter Boughton and log-Walter Boughton; and (b) two five-parameter density functions, namely, Wakeby and log-Wakeby. The AIC is also used in this study as a method of testing for the existence of outlier peak-flow values in the peak annual data used. A modified version of the chi-square goodness-of-fit test is also used, but only for the sake of comparison with the AIC.     

Integrated geophysical survey on the ancient Deák Ferenc Sluice of Hungary

The west channel of the ancient Deák Ferenc which was constructed in 1875 in Hungary was used for controlling the water amount and the east channel was used for the shipping. In the study, four geophysical nondestructive methods were used to this old channel which needs the restoration and reinforcement works. The high-frequency seismic and acoustic measurements were carried out, the resistivity measurements were carried out to map the resistivity distribution of the slab, the seismic direct wave method was used to map the seismic velocities for understanding the stability conditions of the walls and the ground penetrating radar measurements were carried out on the slab and on the walls. The results of integrated study showed us that voids, faults and cracks were detected and the inhomogeneous construction materials were used in the slab. The obtained results emerged that the usage of nondestructive geophysical methods is essential in all stages of restoration and reinforcement works, especially for the ancient structures.     

Object-oriented land cover classification using HJ-1 remote sensing imagery

The object-oriented information extraction technique was used to improve classification accuracy, and addressed the problem that HJ-1 CCD remote sensing images have only four spectral bands with moderate spatial resolution. We used two key techniques: the selection of optimum image segmentation scale and the development of an appropriate object-oriented information extraction strategy. With the principle of minimizing merge cost of merging neighboring pixels/objects, we used spatial autocorrelation index Moran’s I and the variance index to select the optimum segmentation scale. The Nearest Neighborhood (NN) classifier based on sampling and a knowledge-based fuzzy classifier were used in the object-oriented information extraction strategy. In this classification step, feature optimization was used to improve information extraction accuracy using reduced data dimension. These two techniques were applied to land cover information extraction for Shanghai city using a HJ-1 CCD image. Results indicate that the information extraction accuracy of the object-oriented method was much higher than that of the pixel-based method.     

Seismic data reconstruction using multidimensional prediction filters

In this paper we discuss a beyond‐alias multidimensional implementation of the multi‐step autoregressive reconstruction algorithm for data with missing spatial samples. The multi‐step autoregressive method is summarized as follows: vital low‐frequency information is first regularized adopting a Fourier based method (minimum weighted norm interpolation); the reconstructed data are then used to estimate prediction filters that are used to interpolate higher frequencies. This article discusses the implementation of the multi‐step autoregressive method to data with more than one spatial dimension. Synthetic and real data examples are used to examine the performance of the proposed method. Field data are used to illustrate the applicability of multidimensional multi‐step autoregressive operators for regularization of seismic data.     

New Relations of Water Saturation’s Calculus from Well Logs

The saturation in water or hydrocarbon is an important petrophysical parameter used for the evaluation of oil and gas reservoirs. It represents the amount of hydrocarbons in a reservoir. There are many relations to determine the water saturation from well logs by using the physical properties of rocks. The accurate determination of the hydrocarbon formation or the water saturation is given by the accuracy of the parameters used for calculating and by the relations used.     

CT图像的质量分析与控制

本文论述了鉴定ＣＴ图像质量的标准,阐述了提高ＣＴ图像质量的各技术环节,为ＣＴ图像质量控制提出了有效的方法。     

Ground subsidence due to uniform fluid extraction over a circular region within an aquifer

This paper examines the ground subsidence caused by the uniform extraction of fluids from a disc-shaped region located within a poroelastic halfspace. Biot’s theory of poroelasticity is used to examine the problem. The fluid extraction over the circular region at the interior of the poroelastic domain induces time-dependent axisymmetric surface settlements. The theoretical results are also used to examine the accuracy of a multi-physics computational scheme that can be used to examine more complex geological settings.     

Accounting of water flows used in Russian economy and estimation of the water accumulated in exported products

An input–output model was applied to analyze the used freshwater and total used water in Russian economy sectors over 2005–2010. In addition, the sectors that are the main sources of wastewater discharge are identified and the volumes of water sent abroad with exported products are calculated based on data on 2011. The compiled scheme of intersectoral flows and water use in the country can be used as a base for water resources management.