Pipe Service Age Effect on Chlorine Decay in Drinking‐Water Transmission and Distribution Systems

Maintaining acceptable quality of water transported in the transmission and distribution system requires the chlorination of water beyond the treatment plant. While flowing through pipes, the chlorine concentration decreases for different reasons. Reaction with the pipe material itself and the reaction with both the biofilm and tubercles formed on the pipe wall are known as pipe wall demand. This varies with pipe parameters. The aim of this paper was to assess the impact of the service age of pipes on the chlorine wall decay constant. One hundred and fifty three pipe sections of different sizes and four different pipe materials were collected and tested for their chlorine first‐order wall decay constants. The results showed that pipe service age was an important factor that must not be ignored. For the range of the 55 years of pipe service age used in this study, the change in the wall decay ranged from 8 to 531% of the corresponding values in the recently installed pipes. The effect of service age on the wall decay constants was most evident in steel pipes. Other important findings were reached.     

Shkol’noe gold deposit, the Russian Northeast

The Shkol’noe deposit is localized in a small granitoid stock, the root portion of which is traced using geophysical data to a depth of 5–8 km. The high-grade gold ore (33 gpt Au) is enriched in silver and principally differs in ore composition from the previously studied mesothermal gold-quartz and epithermal gold-silver deposits in the Russian Northeast. The main reserves of the Shkol’noe deposit concentrate in bonanzas (20% of the total volume of orebodies). The internal deformation is related to the rearrangement of matter in freibergite; exsolution structures in fahlore and native gold are related to postmineral metamorphism. It is suggested that the ore of the Shkol’noe deposit occupies a transitional position between porphyrytype and epithermal levels of ore deposition.     

The microstructural properties and deformation environments of the Kugarchi folded complex,Southern Urals

The Kugarchi folded complex is located on the western slope of the Southern Urals; it is a region of complex disharmonic folding in the Lower Carboniferous limestones. We revealed and studied two systems of mineral veins and accompanying veinlets in limestones. The microstructural analysis was used to recognize several deformation stages and orientations of the principal strain directions. This folded complex is interpreted to have formed under conditions close to uniaxial compression accompanied by a progressive change in the extensional strain direction from vertical to horizontal.     

Modeling approaches and strategies for data-scarce aquifers: example of the Dar es Salaam aquifer in Tanzania

Management of groundwater resources can be improved by using groundwater models to perform risk analyses and to improve development strategies, but a lack of extensive basic data often limits the implementation of sophisticated models. Dar es Salaam in Tanzania is an example of a city where increasing groundwater use in a Pleistocene aquifer is causing groundwater-related problems such as saline intrusion along the coastline, lowering of water-table levels, and contamination of pumping wells. The lack of a water-level monitoring network introduces a problem for basic data collection and model calibration and validation. As a replacement, local water-supply wells were used for measuring groundwater depth, and well-top heights were estimated from a regional digital elevation model to recalculate water depths to hydraulic heads. These were used to draw a regional piezometric map. Hydraulic parameters were estimated from short-time pumping tests in the local wells, but variation in hydraulic conductivity was attributed to uncertainty in well characteristics (information often unavailable) and not to aquifer heterogeneity. A MODFLOW model was calibrated with a homogeneous hydraulic conductivity field and a sensitivity analysis between the conductivity and aquifer recharge showed that average annual recharge will likely be in the range 80–100 mm/year.     

Inverted basin analysis and geological modeling, Razzak Oil Field, Western Desert, Egypt

This paper deals with a geological modeling based on seismic and well data of the Razzak Oil Field, located in northwestern desert of Egypt aimed mainly at improving the knowledge on inversion tectonics in the sedimentary basin corresponding to the oil field. Contour maps of significant seismic horizons corresponding to the top of Meso-Cenozoic formations which represent the stratigraphic traps of the oil field (top Apollonia, top Abu Roash “G,” top Bahariya, and top Alamein) are presented. The final model consists of geological cross-sections showing the inversion basin in the Razzak Oil Field. From the seismic data interpretation and modeling, we have different results matching with regional tectonic and transcurrent motion model. There are two main fault trends: the first one was northeast–southwest matching the Jurassic rift where the Jurassic is characterized by normal faults that formed in conjunction with the opening of the Neo-Tethys, and the other fault trend is northwest–southeast matching with Cretaceous faults. This is followed by a period of compressive tectonism (Syrian Arc deformation) in which two of the Jurassic normal faulted blocks (one at the northern part and the other at the southern part of the Qattara–Alamein ridge in the Razzak field) are reactivated as reverse faulted by Eocene–Early Oligocene time.     

夏季副高与海温的相互关系及副高预测

通过分析夏季西太平洋副高与前期12月至后期11月的赤道太平洋和北太平洋海温的相关系数分布图,综合比较副高面积指数、西伸脊点和脊线位置与海温的相关关系,讨论副高对海温的反馈作用以及海温与夏季副高的物理联系模型,为副高预测提供依据.     

The early phase of multiple proto-stellar system emerging from collapse of molecular cloud under various initial thermal states

We report on the short timescale intensity fluctuations of PSR B1133+16 and PSR B1237+25 due to scintillation at 1.54 GHz. The structure functions of intensity fluctuations are constructed and the linear fittings are applied to the structure regime in log–log plots to get the slope values. The slope of the SFs for PSR B1237+25 are less than that of PSR B1133+16, and both of them are much less than 2. For PSR B1133+16, the slope values agree very well with a Kolmogorov spectrum predicted value 5/3, whereas PSR B1237+25 not. We investigate the dynamic spectrum and obtain its auto-correlation function (ACF). Scintillation parameters are obtained by fitting to the autocorrelation function of the dynamic spectrum. The observed diffractive interstellar scintillation (DISS) timescales agree well with the observations and are consistent with some expected values, but the observed de-correlation frequency bandwidths are much less than predicted ones. The expected refractive interstellar scintillation (RISS) timescales are also estimated by using our derived diffractive scintillation parameters. They are consistent with the timescales of slow pulse intensity fluctuations. We proposed that the short timescale of pulse intensity variations caused by the DISS are modulated by the slow variations due to the effects of RISS.     

地下巷道弹性位移反分析各种优化方法的探讨

探讨了６种最优化方法（鲍威尔法、单纯形加速法、阻尼最小二乘法、变尺度法、模式搜索法和变量轮换法）在巷道弹性位移反分析中的应用情况。从参数初始点的选择、收敛速度、收敛精度和可靠性方面评价了这６种无约束最优化方法的优劣。     

Potential use of faujasite–phillipsite and phillipsite–chabazite tuff in purification of treated effluent from domestic wastewater treatment plants

Characterization of zeolitic tuff from Jabal Hannoun (HN) and Mukawir (MR) was carried out to examine the ability of using low-cost natural materials in domestic wastewater treatment. The grain size between 0.3 and 1 mm (0.3–1 mm) of the HN and MR has the highest total zeolite grade (faujasite–phillipsite and phillipsite–chabazite) and suitable cation exchange capacity. They were used as fixed-bed ion exchangers and adsorbents. The zeolitic tuff efficiently removed the organic and nitrogen compounds, Pb and Zn from the effluent. One bed volume (1 BV) of the zeolitic tuff is capable to remove up to 95 % of total organic carbon form 500 BV of the effluent. The removal percent of total nitrogen by HN and MR is close to 95 and 90 %, respectively. The zeolitic tuff has an excellent efficiency to remove Pb and Zn from the effluent. 1 BV of HN completely cleans Zn and Pb from 680 and 730 BV of the effluent, respectively, whereas 1 BV of MR is able to clean completely Zn and Pb from 500 and 685 BV of the effluent, respectively. The greater performance of the HN compared with the MR may be explained by its higher zeolites grade and presence of faujasite.     

Spatial crime distribution and prediction for sporting events using social media

ABSTRACT

Sporting events attract high volumes of people, which in turn leads to increased use of social media. In addition, research shows that sporting events may trigger violent behavior that can lead to crime. This study analyses the spatial relationships between crime occurrences, demographic, socio-economic and environmental variables, together with geo-located Twitter messages and their ‘violent’ subsets. The analysis compares basketball and hockey game days and non-game days. Moreover, this research aims to analyze crime prediction models using historical crime data as a basis and then introducing tweets and additional variables in their role as covariates of crime. First, this study investigates the spatial distribution of and correlation between crime and tweets during the same temporal periods. Feature selection models are applied in order to identify the best explanatory variables. Then, we apply localized kernel density estimation model for crime prediction during basketball and hockey games, and on non-game days. Findings from this study show that Twitter data, and a subset of violent tweets, are useful in building prediction models for the seven investigated crime types for home and away sporting events, and non-game days, with different levels of improvement.