UV-Based Advanced Oxidation Processes for Antibiotic Resistance Control: Efficiency, Influencing Factors, and Energy Consumption

Antibiotic resistant bacteria(ARB)with antibiotic resistance genes(ARGs)can reduce or eliminate the effectiveness of antibiotics and thus threaten human health.The United Nations Environment Programme considers antibiotic resistance the first of six emerging issues of concern.Advanced oxidation processes(AOPs)that combine ultraviolet(UV)irradiation and chemical oxidation(primarily chlorine,hydrogen peroxide,and persulfate)have attracted increasing interest as advanced water and wastewater treatment technologies.These integrated technologies have been reported to significantly elevate the efficiencies of ARB inactivation and ARG degradation compared with direct UV irradiation or chemical oxidation alone due to the generation of multiple reactive species.In this study,the performance and underlying mechanisms of UV/chlorine,UV/hydrogen peroxide,and UV/persulfate processes for controlling ARB and ARGs were reviewed based on recent studies.Factors affecting the process-specific efficiency in controlling ARB and ARGs were discussed,including biotic factors,oxidant dose,UV fluence,pH,and water matrix properties.In addition,the cost-effectiveness of the UV-based AOPs was evaluated using the concept of electrical energy per order.The UV/chlorine process exhibited a higher efficiency with lower energy consumption than other UV-based AOPs in the wastewater matrix,indicating its potential for ARB inactivation and ARG degradation in wastewater treatment.Further studies are required to address the trade-off between toxic byproduct formation and the energy efficiency of the UV/chlorine process in real wastewater to facilitate its optimization and application in the control of ARB and ARGs.

Experimental salt cavern in offshore ultra-deep water and well designevaluation for CO_(2) abatement

This paper presents a proposal for an experimental salt cavern in offshore ultra-deep water for CO2 abatement,including the instrumentation plan and well conceptual design evaluated for carbon capture and storage(CCS)application.These studies are based on applied computational mechanics associated with field experimentation that has contributed to the technical feasibility of the underground potash mine at the State of Sergipe in Brazil.This knowhow allowed the stability analysis of several salt caverns for brine production at the State of Alagoas in Brazil and to the drilling through stratified thick layers of salt of the pre-salt reservoirs in Santos Basin.Now,this knowledge has been applied in the design of onshore and offshore salt caverns opened by dissolution for storage of natural gas and CO2.The geomechanical study,through the application of computational mechanics,of offshore giant salt caverns of 450 m high by 150 m in diameter,shows that one cavern can store about 4 billion Sm3 or 7.2 million tons of CO2.Before the construction of the giant cavern,which will be the first gas storage offshore in the world,it has been decided to develop an experimental one,with smaller size,to obtained field parameters.The experimental cavern will allow the calibration of parameters to be used in the structural integrity analysis of the cavern and well for storage of natural gas which is rich in CO2 under high pressure.

Numerical Simulation and Analysis of Storm Surges Under Different Extreme Weather Event and Typhoon Experiments in the South Yellow Sea

In this study,a coupled tide-surge-wave model was developed and applied to the South Yellow Sea.The coupled model simulated the evolution of storm surges and waves caused by extreme weather events,such as tropical cyclones,cold waves,extratropical cyclones coupled with a cold wave,and tropical cyclones coupled with a cold wave.The modeled surge level and significant wave height matched the measured data well.Simulation results of the typhoon with different intensities revealed that the radius to the maximum wind speed of a typhoon with 1.5 times wind speed decreased,and its influence range was farther away from the Jiangsu coastal region;moreover,the impact on surge levels was weakened.Thereafter,eight hypothetical typhoons based on Typhoon Chan-hom were designed to investigate the effects of varying typhoon tracks on the extreme value and spatial distribution of storm surges in the offshore area of Jiangsu Province.The typhoon along path 2 mainly affected the Rudong coast,and the topography of the Rudong coast was conducive to the increase in surge level.Therefore,the typhoon along path 2 induced the largest surge level,which reached up to 2.91 m in the radial sand ridge area.The maximum surge levels in the Haizhou Bay area and the middle straight coastline area reached up to 2.37 and 2.08 m,respectively.In terms of typhoons active in offshore areas,the radial sand ridge area was most likely to be threatened by typhoon-induced storm surges.

Deduction and experimental investigation of constitutive relation of liquefaction of saturated sand

According to the existing problems of liquefaction models of saturated sand that were put forward under dynamic action,on the basis of Handin-Drnevich model,a new calculating model of the dynamic constitutive relation of saturated sand was put forward.The model was based on the basic hypothesis of instantaneous limit balance according to the basic principle that the stress estate is the destroyed condition was not overstepped.The calculated method of increment nonlinear was referenced and combined with the excellence of the model of distributed particles.The process of vibrating liquefaction of saturated sand was divided into some areas.And the phenomena of shearing dilatation and unloading shrink of saturated sand were considered.On above basic a new calculating constitutive relation model was proposed.There are a few parameters in the model.The physical means of the parameters are very evident and quantized.They could be obtained from the dynamic triaxial test in door.The model was contrasted and validated with the results of the dynamic triaxial test in door.The comparison of the results of the dynamic triaxial test in door and the calculating results of the model indicates that all sorts of phenomenon appearing in the process of liquefaction of saturated sand could be more perfectly reflected by the model.Especially at the initial stage of development of pore water pressure and strain of saturated sand,the results of the dynamic triaxial test in door are consistent with the calculated results of the model very much.But there is some difference between the results at the anaphase of development of pore water pressure and strain.On the path of stress,the calculating and experimenting ultimate state surfaces are almost identical.

3D Nonlinear Numerical Simulation of Intact and Debonded Reinforced Concrete Beams

To study the behaviour of reinforced concrete (RC) structures with sections of concrete removed and the reinforcement exposed, 3D nonlinear numerical analysis was performed upon both intact and debonded RC beams by using finite element techniques. The deformational characteristics and the ultimate loads were obtained through numerical models, as well as crack and stress distributions. The failure modes can also be deduced from computational results. Compared with intact beams, the normal assumptions of plane section behaviour is not hold true and the patterns of stress and strain are different in debonded RC beams. The numerical results show good consistency with experimental data. This kind of numerical simulation is a supplement to existing codes.

Prediction of Strength Properties of Soft Soil Considering Simple Soil Parameters

Cohesion is an important soil strength parameter for the overall structure and quality of building foundations as well as slope stability. For a civil engineering project, cohesion (c) can be determined directly from mainly unconfined compression tests, direct shear tests, and triaxial tests of soil. However, it’s quite challenging to collect soil samples as there are time and cost constraints, as well as a diversity of soil deposits. Hence, this research aims to demonstrate a simplified method in order to determine the strength parameter of cohesive soil. Here, we propose an alternative solution adopting statistical correlations and machine learning techniques to establish correlations between the liquid limit, plastic limit, moisture content and %fine of soil with the strength parameter. In laboratory testing, these parameters can be obtained easily and these tests are relatively simple, quick to perform and also comparatively inexpensive. Hence, several test results were used from 100 boreholes which were soft soil or silty clay-type soil. Using the collected in-situ and lab test results of soil samples, a Multiple Linear Regression (MLR), Random Forest Regression (RFR) and Machine Learning (ML) model will be developed to establish a relationship between cohesion and the available test results. In order to assess the performances of both models, several performance indicators like: correlation coefficient (R2), mean squared error (MSE), root mean square error (RMSE), and mean average error (MAE) will be used. These correlation coefficients will be used to demonstrate the prediction capacity and accuracy of both models. It should be noted that this approach will substitute the conventional testing required for strength parameters, which is both expensive and time-consuming.

Eigenfrequency analysis of bridges using a smartphone and a novel low-cost accelerometer prototype

Researchers are paying increasing attention to the development of low-cost and microcontroller-based accelerometers,in order to make structural health monitoring feasible for conventional bridges with limited monitoring budget.Parallel with the low-cost sensor development,the use of the embedded accelerometers of smartphones for eigenfrequency analysis of bridges is becoming popular in the civil engineering literature.This paper,for the first time in the literature,studies these two promising technologies by comparing the noise density and eigenfrequency analysis of a self-developed,validated and calibrated low-cost Internet of things based accelerometer LARA(low cost adaptable reliable accelerometer)with those of a state of the art smartphone(iPhone XR).The eigenfrequency analysis of a footbridge in San Sebastian,Spain,showed that the embedded accelerometer of the iPhone XR can measure the natural frequencies of the under study bridge.

Simulation and optimization approach for uncertainty-based short-term planning in open pit mines

Accuracy in predictions leads to better planning with a minimum of opportunity lost. In open pit mining,the complexity of operations, coupled with a highly uncertain and dynamic production environment,limit the accuracy of predictions and force a reactive planning approach to mitigate deviations from original plans. A simulation optimization framework/tool is presented in this paper to account for uncertainties in mining operations for robust short-term production planning and proactive decision making. This framework/tool uses a discrete event simulation model of mine operations, which interacts with a goalprogramming based mine operational optimization tool to develop an uncertainty based short-term schedule. Using scenario analysis, this framework allows the planner to make proactive decisions to achieve the mine's operational and long-term objectives. This paper details the development of simulation and optimization models and presents the implementation of the framework on an iron ore mine case study for verification through scenario analysis.

Evaluation of mobility impact on urban work zones using statistical models

This work correlated the detailed work zone location and time data from the Wis LCS system with the five-min inductive loop detector data. One-sample percentile value test and two-sample Kolmogorov-Smirnov(K-S) test were applied to compare the speed and flow characteristics between work zone and non-work zone conditions. Furthermore, we analyzed the mobility characteristics of freeway work zones within the urban area of Milwaukee, WI, USA. More than 50% of investigated work zones have experienced speed reduction and 15%-30% is necessary reduced volumes. Speed reduction was more significant within and at the downstream of work zones than at the upstream.

Rockfall localization from seismic polarization considering multiple triaxial geophones and frequency bands

Boulder/rock mass movements generate ground vibrations that can be recorded by geophone networks.Generally,there are two methods applied to rockfall trajectory reconstruction or rockfall seismic localization.One method uses seismic wave arrival times and is achieved by minimizing the differences in signal arrival times between multiple stations by grid map searching.The other method uses seismic polarization and is achieved by calculating eventsource back azimuths from the seismic polarizations of rockfall signals.In this study,we proposed the use of an overdetermined matrix for joint localization based on the polarization method.The overdetermined matrix considers the contributions of all geophones in the network,and at each geophone is assigned a different weight according to the recorded signal qualities and the reliability of the calibrated back azimuths.This method shows a great advantage relative to the case in which only two sensors are employed.Besides,we suggested three marker parameters for proper frequency band selection in back azimuth calculations:energy,rectilinearity,and a special permanent frequency band(SPF).We found that the back azimuths calculated with energy and an SPF are generally close to the real back azimuths measured in the field,while the SPF is limited by seismic attenuation due to a long-distance propagation.The localization results of rockfalls were validated by using field camera videos and in situ calibrations.Three typical cases and 43 artificially released rockfalls are presented in this paper.The proposed method provides an interesting way to locate rockfall events and track rockfall trajectories and avoids the difficulties of obtaining accurate arrival times,as required by the arrival times method.

Use of ANSYS for Thermal Analysis in Mass Concrete

With the increasing development of Brazil in recent years, major engineering construction works have been designed and built, partieutarly those involving large volumes of mass concrete, such as in the case of dams. Mass concrete, due to its large size and volume, presents a considerable temperature rise caused by cement grain hydration. This temperature rise can be sufficient to cause concrete crack and/or cracking, which may lead to serious problems. In this paper, we sought to study heat generation and temperature field in mass concrete through ANSYS software, which uses finite element method to analyze the problem. This program allows temperatures to be checked for different concrete ages. With that, it is possible to evaluate the temperatures obtained and the factors influencing the results in a short period of time at a low cost. With the help of the software, it is possible to check the temperatures for different concrete properties by analyzing them on different concreting days. Therefore, it was possible to establish that the properties of the concrete directly influence the temperature evolution phenomenon.

Pavement Friction and Skid Resistance Measurement Methods: A Literature Review

Driving safety is of significance in the automobile industry and transportation systems. Pavement skid resistance has long been recognized as the most important parameter in reducing traffic accidents especially in wet conditions. The knowledge of the friction coefficient and skid resistance is very valuable information for safety enhancement of roads. Thus, it is important to find proper methods for measuring skid resistance and frictional properties of the pavement surface. There is a wide range of measurement methods and devices for measuring skid resistance. This paper presents a review on the research studies that have been done on characterization of the frictional properties of the pavement surface and discussed methods used for measurement and evaluation of texture characteristics and the strengths and weaknesses of these methods. Finally, some ideas have been suggested to develop new methods for better and proper measurement of skid resistance.

Seismic hazard prediction using multispectral amplification maps in a complex topographic area: A case study of Qiaozhuang town, Sichuan Province, Southwest China

Earthquakes can cause widely distributed slope failures and damage in mountainous areas.The accurate prediction of ground motions in mountainous areas is essential for managing the seismic risk of urban cities near mountains but is restricted primarily by complex seismic site amplification effects in areas of uneven terrain.This study selected Qiaozhuang town located in the Qingchuan–Pingwu fault zone,Southwest China,as a case study.A simulator for mapped seismic responses using a hybrid model(Si Se RHMap)was applied to compute the multispectral seismic topographic amplification maps at the three slope units surrounding Qiaozhuang town(Weigan hill,Mt.Dong,and Mt.Shizi).Post-earthquake damage survey maps,1 D seismic site response spectral ratios,and H/V spectral ratios of earthquake data were used to validate the computed seismic site amplification factors and resonance frequencies.The results suggest that strong topographic amplification effects usually occur at distinct slope locations,such as hilltops,convex slope positions,upslope,and narrow ridges.The computed topographic amplification factors in the study area reached up to 2.4 at upslope or hilltops,and the resonance frequencies were between 3 and 10 Hz.Topographic effects can be as important as stratigraphic effects when assessing seismic amplification effects in the study area.We conclude that both topographic and stratigraphic effects should be considered in the comprehensive seismic hazard assessment of the study area or other similar mountain towns.

Agricultural Water Conservation in the High Plains Aquifer and Arikaree River Basin

Yuma County is the top crop producing County in Colorado that is dependent on groundwater supplies from the High Plains aquifer for irrigation. The Arikaree River, a tributary of the Republican River in eastern Colorado, is supplied with water from the High Plains aquifer. The Arikaree River alluvium is also a habitat for many terrestrial invertebrates and the threatened Hybognathus hankinsoni (Brassy Minnow). The constant demand on the High Plains aquifer has created declining water levels at the linear rate of 0.183 m/year with the deepest pool in the Arikaree River drying up in 8 to 12 years. In addition to the demands for habitats, the surrounding irrigated agricultural lands require water for crop production. These challenges are currently confronting farmers in eastern Colorado and this research presents possible alternatives to meet these demands. This research presents a combination water balance model, water conservation model, and water conservation survey results from farmers in eastern Colorado to identify alternatives to extend the life of the Arikaree River. The first alternative was to examine the reduction in irrigation water from removing the 18 alluvial irrigation wells that could extend the Arikaree River pools from drying up for 30 years. The other scenario found that water conservation practices with participation of 43%, 57%, and 62% of farmers would extend the drying time to 20, 30, and 40 years, respectively. The final alternative studied was the required participation in conservation practices to stop the decline of the High Plains Aquifer. The analysis found that 77% participation of farmers in all conservation alternatives or reducing pumping by 62.9% would be necessary to stabilize the High Plains Aquifer.

Validity of a Making Method for a Homogeneous Specimen Using Micro-wave

It is too difficult for a compacted specimen of unsaturated clay prepared and used in a laboratory test to have homogeneous water content and porosity. Although there have been many hydraulic and mechanical studies, there are few papers related to homogeneity of specimen. However, it is clear that homogeneity of specimen influences mechanical properties. In this paper, the use of micro-waves is proposed as method for making homogeneous specimens. The study results indicate that specimens made by micro-waves are more homogeneous than compacted specimens.

Behaviors of Bellows-Like Origami Patterned Tubes with Trapezoidal Patterns

In this paper, we show one of the possibility utilizing typical origami structures for civil engineering fields such as the bridge bearing support. We numerically investigate axial spring constants and buckling behaviors of bellows-like origami tube structures. The bellows-like origami tube structures, which can be folded because of elastic deformations, work as a kind of spring. If the initial heights of the bellows-like origami tubes are less than 90% of the height of the prismatic tubes without bellows-like folded lines, the spring constants of the bellows-like tubes are very low compared with those of the prismatic tubes. The buckling loads and patterns of the bellows-like tubes vary depending on the initial heights of the tubes.

Seismic performance of isolation system of rolling friction with springs

In order to study an isolation system of rolling friction with springs, computer programs were compiled to evaluate the seismic performance based on its movement characteristics. Through the programs, the influences of various seismic performance factors, e.g., rolling friction coefficient, spring constant, were systematically investigated. Results show that by increasing the rolling friction coefficient, the structural relative displacement due to seismic load effectively decreases, while the structural response magnitude varies mainly depending on the correlations between the following factors: the spring constant, the earthquake intensity, and the rolling friction coefficient. Furthermore, increasing the spring constant can decrease the structural relative displacement, as well as residual displacement, however, it increases the structural response magnitude. Finally, based on the analyses of various seismic performance factors subjected to the scenario earthquakes, optimized theoretical seismic performance can be achieved by reasonably combining the spring constant and the rolling friction coefficient.

堆肥对重金属污染的水稻根际土壤细菌群落的剂量依赖性影响

在复合重金属污染的水稻土壤中分别添加1%、5%和10%(质量分数)的堆肥,150 d后观察土壤微生物群落的结构和组成变化。研究发现,堆肥对根际细菌群落的影响表现出剂量依赖效应。低等(1%)和中等(5%)堆肥添加量对根际细菌群落结构的影响比对非根际细菌群落的影响更大。根际土壤细菌多样性在添加堆肥后明显低于非根际土壤细菌多样性。冗余分析(RDA)结果表明,根际和非根际细菌群落对土壤理化性质(如p H、Pb、Cd和Cu含量)变化的响应不同,可能是根际和非根际细菌群落差异的原因之一。因此,在农业管理中应该考虑堆肥的施加对根际微生物的影响。

EBEX-2000湍流热通量订正和地表能量平衡闭合问题研究

运用EBEX-2000实验资料,分析超声虚温订正和Webb订正对湍流热通量计算的影响及这两种订正的主要控制因子,并在对湍流热通量进行修正的基础上简单讨论了能量平衡闭合率（EBR）的影响因子,结合实际的天气、地形条件给出了比较合理的解释。研究结果表明：超声虚温订正值为–40~2 W/m^2,有明显日变化,均值为8 W/m^2,主要受大气稳定度和水汽垂直梯度影响;Webb订正值范围为5~14 W/m^2,订正量均值较小,约1.8 W/m^2,白天为正值,夜间为负值,主要受波文比和空气比湿的影响,出现较大修订值的几率很小;30min平均的能量平衡闭合比率（EBR）约为0.63,其日变化幅度剧烈,日变化幅度及夜间离散度很大,并且随土壤含水量的突然上升而急剧下降。

一个三维水动力学模型及其在水环境中的适用性试验

发展了一个三维水动力学模型。该模型在水底磨擦项计算中，采用了流速的平方根法；在湍流扩散系数的估算中，采用了带稳定度函数的参数化方案；对垂直方向上的坐标进行了压缩，引入σ坐标；对时间变量则采用了分离模式技术，即外部模式（快过程）与内部模式（慢过程）；而求解外部模式时，采用了显式一隐式格式交错法（ＡＤＩ），从而使模型不仅计算时间缩短，且可应用于水很深而水平空间尺度很小，又有热力分层的水域中。最后作为该模型的一个实用性试验，选择了美国犹他州Ｅａｓｔ Ｃａｎｙｏｎ水库，利用该模型探讨了温跃层对风、人流及出流变化的响应情况。