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In this research, all the efforts, based on a series of molecular dynamics simulations on the interfacial process between VOC-contaminated air and acidic sulfate, were made to find how the structures and properties of VOCs are related to the formation of SOAs. The experimental fractional aerosol coefficients (FACs) were used to quantify the SOA formation and 14 VOC species were chosen based on the atmosphere inventory and the FAC magnitude. Finally, the quantitative relationship (QR) was found through the FAC as a function of the two variables the total valid interactions (Tg) and the diffusion coefficient (D), with R square 0.94. Meanwhile, the effect of water was explored and the QR was proved to be rational and reliable. The QR not only explained the SOA formation capacity of VOCs, but could also predict the SOA formation of new molecules.

With the development of clinical medicine-related technologies, the detection of cancer biomarkers has become an essential method for cancer diagnosis. DNA self-assembly is a valuable approach to monitor low-abundance miRNA. Herein, we report a novel DNA jungle biosensor for target-induced enzyme-free and label-free ultrasensitive detection of miRNA-21 in biological samples. The method consists of two parts. The target catalyzes the assembly of the hairpin to form the backbone of the DNA jungle, and the auxiliary probes hybridize to form branches freely and undirectedly. The DNA jungle can be self-assembled seeded from a single target initiator, affording the potential for screening a single target molecule. Vitro assays show that the DNA jungle offers very high amplification efficiency and specificity, with a direct detection limit of 1 aM. This DNA jungle strategy can provide a useful platform for low-abundance biomarker detection for cell biology and diagnostics.

Studies on the assessment of green infrastructure (GI) practice implementation effect and cost efficiency on an urban watershed scale helps the GI practice selection and investment decisions for sponge city construction in China. However, few studies have been conducted for these topics at present. In this study, the Long-Term Hydrologic Impact Assessment&mdash, Low Impact Development (L-THIA-LID) 2.1 model was applied to assess the effectiveness and cost efficiency of GI practices on surface runoff volume reduction in an urban watershed&mdash, the Hexi watershed, Nanjing City, China. Grassed swales, bioretentions, green roofs, rain cisterns, permeable pavements, wet ponds, dry ponds, and wetlands were chosen as potential GI practices for sponge city construction based on feasibility analysis. Results showed that grassed swales were the most cost-effective practice (0.7 CNY/m3/yr), but the total implementation effect of grassed swales was not obvious due to the small area of suitable locations. Permeable pavements performed best on runoff reduction, but the cost efficiency was much lower. Correspondingly, bioretentions were compromise practices. Green roofs were the least cost-effective practices, with the cost efficiency at 122.3 CNY/m3/yr, but it was much lower for rain cisterns, which were 3.2 CNY/m3/yr. Wet ponds, dry ponds, and wetlands were potential practices implemented in development areas, of which dry ponds were the most cost-effective (2.7 CNY/m3/yr), followed by wet ponds (10.9 CNY/m3/yr). The annual runoff volume of the total area could be reduced by up to 47.01% by implementing GI practices in buildup areas. Rain cisterns (RC) and permeable pavements (PP) were the best combination for this area, and bioretentions (BR) and green roofs (GR) followed. Grassed swales (GS1), dry ponds (DP), wet ponds (WP), and wetlands (WL) were not wise choices due to the small suitable location areas. This study also demonstrated the feasibility of the L-THIA-LID 2.1 model for the evaluation of GI practice implementation effects and cost efficiency on urban runoff in sponge city construction in China.

In this study, the growth periods of summer maize was divided into seedling, booting and flowering-grain stage. Based on the simulation results of AquaCrop model, the drought loss sensitivity of summer maize in different growth periods was analyzed. The sensitivity curves fitting using the soil moisture content of the effective root zone and the fixed soil layer both indicated that the booting stage was the most sensitive to water stress, which was the critical period for irrigation, followed by the seedling stage. Compared with the curve parameters fitted by the soil water content of the effective root zone, the maximum Biomass Loss Rate fitted by the fixed soil layer water content was higher and the Drought Hazard Index corresponding to the disaster-causing point and the turning point in the seedling stage moved backward. Accordingly, the best irrigation opportunity may be missed and resulting in a large reduction in production if an irrigation scheme is formulated at the seedling stage based on the sensitivity curve of summer maize fitted by the water content of a fixed soil layer. This study also adapted the Jensen model to calculate the normalized moisture sensitivity coefficient and studied the response of final crop yield to water deficit in different growth periods. The results showed that the normalized moisture sensitivity coefficients at the seedling stage, booting stage, and flowering-grain stage were 0.251, 0.524, 0.224 respectively, which verified the rationality and feasibility of using the cumulative loss of biomass to measure the final yield loss.

Identifying the key processes and primary sources of water and nutrient losses is essential for water quantity and quality management in watersheds. This is especially true in the U.S. Corn Belt, which has been recognized as the primary region contributing nutrient loads to the Great Lakes and the Gulf of Mexico. A SWAT (Soil and Water Assessment Tool) model simulation was set up in an agricultural watershed with about 50% tile drainage area in the U.S. Corn Belt to study the water and nutrient balance components for the whole watershed and the corn-soybean rotation system. The SWAT model was improved to consider additional nitrogen and phosphorus loss paths from the soil. The model was comprehensively calibrated and validated for simulating monthly stream flow, total suspended solids (TSS), nutrient loads (including total Kjeldahl nitrogen (TKN), nitrate and nitrite nitrogen (NO

Storm events and soil erosion can adversely impact flood control, soil conservation, water quality, the recreation economy, and ecosystem biodiversity in urban systems. Urban Low Impact Development practices (LIDs) can manage stormwater runoff, control soil losses, and improve water quality. The Water Erosion Prediction Project (WEPP) model has been widely applied to assess the responses of hydrology and soil losses to conservation practices in agricultural and forested areas. This research study is the first to calibrate the WEPP model to simulate streamflow discharge in the Brentwood watershed in Austin, Texas and apply the calibrated WEPP model to assess the impacts of LIDs. The costs and impacts of various LID scenarios on annual water balance, and monthly average, and daily runoff volumes, and sediment losses at hillslopes and at the watershed outlet were quantified and compared. The LID scenarios identified that native planting in Critically Eroding Areas (CEAs), native planting in all suitable areas, native planting in CEAs with detention ponds, and native planting in all suitable areas with detention ponds could reduce the predicted average annual stormwater runoff by 20–24% and sediment losses by 86–94% at the watershed outlet, and reduce the average annual soil loss rates on hillslope profiles in sub-watersheds by 86–87% with the lowest costs (USD 2991/yr–USD 5257/yr). Watershed/field characteristics, locations, areas, costs, and the effectiveness of the LID practices were essential in choosing the LID scenarios. These research results can help guide decision-making on the selection and implementation of the most economical and suitable LID practices to strengthen the climate resilience and environmental sustainability of urban systems.

Rain barrels/cisterns, a popular type of low impact development (LID) practice, can restore urban hydrological processes and decrease municipal water use by harvesting roof runoff for later use, such as landscape irrigation. However, tools to assist decision makers in creating efficient rainwater harvesting and reuse strategies are limited. This study improved the Soil and Water Assessment Tool (SWAT) in simulating the subdaily hydrological impacts of rainwater harvesting for landscape irrigation with rain barrels/cisterns, including the simulation of rainwater harvesting with rain barrels/cisterns, rainwater reuse for auto landscape irrigation, evapotranspiration, initial abstraction, impervious area, soil profile, and lawn management operation. The improved SWAT was applied in the urbanized Brentwood watershed (Austin, TX) to evaluate its applicability and investigate the impacts of rainwater harvesting and reuse strategies on the reductions and reduction efficiencies (reductions per volume of rain barrels/cisterns implemented) of field scale runoff (peak and depth) and watershed scale streamflow (peak and volume) for two storm events. Scenarios explored included different sizes of rain barrels/cisterns, percentages of rooftop areas with rain barrels/cisterns implemented, auto landscape irrigation rates, and landscape irrigation starting times. The performance of rainwater harvesting and reuse strategies, which is determined by features of fields, watersheds, and storm events, varied for different reduction goals (streamflow or runoff, and peak or depth/volume). For instance, the scenario with rain barrel/cistern sizes of 7.5 mm (design runoff depth from treated roof area) and the scenario with 10% of suitable area implemented with rain barrels/cisterns provided the highest peak streamflow reduction efficiency and total streamflow volume reduction efficiency at the watershed scale, respectively for the smaller storm event. To achieve sustainable urban stormwater management, the improved SWAT model has enhanced capability to help stakeholders create efficient rainwater harvesting and reuse strategies to reduce field scale runoff and watershed scale streamflow.

Chlorination is an effective method to control biofilm formation in enclosed pipelines. To date, very little is known about how to control biofilms at the mesoscale in complex pipelines through chlorination. In this study, the dynamic of microbial communities was examined under different residual chlorine concentrations on the biofilms attached to labyrinth channels for drip irrigation using reclaimed water. The results indicated that the microbial phospholipid fatty acids, extracellular polymeric substances, microbial dynamics, and the ace and Shannon microbial diversity indices showed a gradual decrease after chlorination. However, chlorination increased microbial activity by 0.5–19.2%. The increase in the relative abundances of chloride-resistant bacteria (Acinetobacter and Thermomonas) could lead to a potential risk of chlorine resistance. Thus, keeping a low chlorine concentration (0.83 mg l−1 for 3 h) is effective for controlling biofilm formation in the labyrinth channels.

Although words are basic semantic units in text, phrases, and expressions contain additional information, which is important for text classification. To capture this information, traditional algorithms extract composite features via word sequences or co-occurrences, such as bigrams and termsets, but ignore the influence of stop words and punctuation, which results in huge amounts of weak features. In this paper, we propose a text structure-based algorithm to extract composite features. Termsets that cross punctuation marks or stop words in the text are excluded. To eliminate redundancy, a novel discriminative measure containing two factors is suggested. One is employed to measure the relevancy, while the other is incorporated to increase the values of composite features, whose class frequencies are much smaller than those of their sub-features. The experiments on three benchmark datasets with both a support vector machine and a naive Bayes classifier illustrate the effectiveness of the approach.

Cost effectiveness is a major concern when implementing low impact development (LID) practices for urban stormwater management (USWM). To optimize LID layout, an efficient and more reliable method, namely, the Marginal-Cost-based Greedy Strategy (MCGS) was developed based on the economic law of increasing marginal costs (MCs) and the stepwise minimization of MCs. To verify its broad applicability, MCGS was applied in three case studies in China with different system settings and environmental goals. Both Cases I and II were watershed-scale studies in Suzhou City urban districts, but in Case II, the impact of future uncertainties (i.e., climate change, urban expansion, and LID performance degradation) on USWM system performance was considered. Case III was a block-scale study of the Xixian New District (a pilot “Sponge City” in China), which involved a rainwater pipe network and a complicated environmental goal. Compared with the extensively used but complicated NSGA-II, the MCGS performed better in terms of yielding more converged performance trade-offs, providing more choices for city planners, and requiring much less computational resources in all three cases. Meanwhile, MCGS established an optimal pathway for multi-stage LID layout planning. The success of MCGS indicated that the MC of a LID practice determined its favorability in an USWM system.

Best management practices (BMPs) are popular approaches used to improve hydrology and water quality. Uncertainties in BMP effectiveness over time may result in overestimating long-term efficiency in watershed planning strategies. To represent varying long-term BMP effectiveness in hydrologic/water quality models, a high level and forward-looking modeling framework was developed. The components in the framework consist of establishment period efficiency, starting efficiency, efficiency for each storm event, efficiency between maintenance, and efficiency over the life cycle. Combined, they represent long-term efficiency for a specific type of practice and specific environmental concern (runoff/pollutant). An approach for possible implementation of the framework was discussed. The long-term impacts of grass buffer strips (agricultural BMP) and bioretention systems (urban BMP) in reducing total phosphorus were simulated to demonstrate the framework. Data gaps were captured in estimating the long-term performance of the BMPs. A Bayesian method was used to match the simulated distribution of long-term BMP efficiencies with the observed distribution with the assumption that the observed data represented long-term BMP efficiencies. The simulated distribution matched the observed distribution well with only small total predictive uncertainties. With additional data, the same method can be used to further improve the simulation results. The modeling framework and results of this study, which can be adopted in hydrologic/water quality models to better represent long-term BMP effectiveness, can help improve decision support systems for creating long-term stormwater management strategies for watershed management projects.

Among all coating methods, atomic layer deposition (ALD), which can provide a precise thickness control at the angstrom or the monolayer level, appears to be one of the most promising techniques. To investigate the interfacial charge-transfer mechanism from semiconductor–molecule–metal systems, the order of different layers is very essential because the charge-transfer process can be affected by the interfacial contact order of different materials. Also, for TiO2/MBA/Ag charge-transfer (CT) investigation, homogeneous assembling of TiO2 with precisely controllable thickness is of great importance because the energy level of semiconductor is sensitive to its size at the nanoscale. Here, unlike previous 3D composite CT models, our semiconductor–molecule–metal interfacial CT models are fabricated with the ALD and e-beam evaporation techniques, which ensures the accuracy of the CT investigation. The surface-enhanced Raman scattering (SERS) technique is adopted in the investigation of the interfacial charge-tra...

One of the important challenges in electron beam lithography is nanofabrication on nonflat or irregular surfaces. Although spin coating is the most popular technique for resist coating, it is not suitable for nonflat, irregular substrates because a uniform film cannot be achieved on those surfaces. Here, it is demonstrated that single layer surface-grafted PMMA can be used as a negative-tone e-beam resist, and it can be applied to nonflat, irregular surfaces as well as flat, conventional surfaces. Although it is well known that heavily exposed PMMA undergoes cross-linking and works as a negative-tone e-beam resist when developed by solvent, solvent does not work as a developer for negative-tone single-layer surface-grafted PMMA. Instead, thermal treatment at 360 °C for 1 min is used to develop PMMA.

Various computer models, ranging from simple to complex, have been developed to simulate hydrology and water quality from field to watershed scales. However, many users are uncertain about which model to choose when estimating water quantity and quality conditions in a watershed. This study compared hydrologic/water quality models including Spreadsheet Tool for the Estimation of Pollutant Load (STEPL)-Purdue, Soil and Water Assessment Tool (SWAT), High Impact Targeting (HIT), Long-Term Hydrologic Impact Assessment (L-THIA), Pollutant Load (PLOAD), Spatially and Temporally Distributed Model for Phosphorus Management (STEM-P), Region 5, and ensemble modeling (using STEPL-Purdue, SWAT, L-THIA, PLOAD, and STEM-P). Model capabilities, inputs, and underlying methods to estimate streamflow, surface runoff, baseflow, nutrients, and sediment were examined. Uncalibrated, calibrated, and validated outputs of these models and uncalibrated ensemble modeling in estimating water quantity and quality for a 41.5 km2 agricultural watershed in Northeastern Indiana were explored, and suggestions were provided on the selection and use of models. Models need to be selected carefully based on the simulation objectives, data availability, model characteristics, time constraints, and project budgets.

To address the harmful algal blooms problem in Lake Erie, one solution is to determine the most cost-effective strategies for implementing agricultural best management practices (BMPs) in the Maumee River watershed. An optimization tool, which combines multi-objective optimization algorithms, SWAT (Soil and Water Assessment Tool), and a computational efficient framework, was created to optimally identify agricultural BMPs at watershed scales. The optimization tool was demonstrated in the Matson Ditch watershed, an agricultural watershed in the Maumee River basin considering critical areas (25% of the watershed with the greatest pollutant loadings per area) and the entire watershed. The initial implementation of BMPs with low expenditures greatly reduced pollutant loadings; beyond certain levels of pollutant reductions, additional expenditures resulted in less significant reductions in pollutant loadings. Compared to optimization for the entire watershed, optimization in critical areas can greatly reduce computational time and obtain similar optimization results for initial reductions in pollutant loadings, which were 10% for Dissolved Reactive Phosphorus (DRP) and 38% for Total Phosphorus (TP); however, for greater reductions in pollutant loadings, critical area optimization was less cost-effective. With the target of simultaneously reducing March–July DRP/TP losses by 40%, the optimized scenario that reduced DRP losses by 40% was found to reduce 51.1% of TP; however, the optimized scenario that reduced TP losses by 40% can only decrease 11.3% of DRP. The optimization tool can help stakeholders identify optimal types, quantities, and spatial locations of BMPs that can maximize reductions in pollutant loadings with the lowest BMP costs.

Evaluation of the effectiveness of green infrastructure (GI) practices on improving site hydrology and water quality and their associated cost could provide valuable information for decision makers when creating development/re-development strategies. In this study, a watershed scale rainfall-runoff model (the Long-Term Hydrologic Impact Analysis - Low Impact Development model, the L-THIA-LID 2.1 model) was enhanced to improve its simulation of urban water management practices including GI practices. The enhanced model (L-THIA-LID 2.2) is capable of: simulating in more detail impervious surfaces including sidewalks, roads, driveways, and parking lots; conducting cost calculations for converting these impervious surfaces to porous pavements; and, selecting suitable areas for bioretention in the study area. The effectiveness of GI practices on improving hydrology and water quality in a combined sewer overflow urban watershed—the Darst Sewershed in the City of Peoria, IL—was examined in eleven simulation scenarios using 8 practices. The total cost and the cost effectiveness for each scenario considering a 20-year practice lifetime were calculated. Results showed: combined implementation of GI practices performed better than applying individual practices alone; adoption levels and combinations of GI practices could potentially reduce runoff volume by 0.2–23.5%, TSS by 0.18–30.8%, TN by 0.2–27.9%, and TP by 0.2 to 28.1%; adding more practices did not necessarily achieve substantial runoff and pollutant reductions based on site characteristics; the most cost-effective scenario out of eleven considered had an associated cost of $9.21 to achieve 1 m3 runoff reduction per year and $119 to achieve 1 kg TSS reduction per year assuming residents' cooperation in implementing GI practices on their properties; adoption of GI practices on all possible areas could potentially achieve the greatest runoff and pollutant reduction, but would not be the most cost-effective option. This enhanced model can be applied to different locations to support assessing the beneficial uses of GI practices.

Choline chloride based deep eutectic solvents have showed great potential in lignocellulosic biomass pretreatment. In this study, for DES pretreatment with different hydrogen bond donners of different raw materials under different reaction conditions, multivariate analysis methods including principal component analysis and partial least squares analysis were used for reveal the pretreatment mechanism by evaluating the inner relationships among 42 key process factors. Furthermore, based on molecular simulation, the detailed relationships between key variables were further analyzed. Meanwhile, four-dimensional color graphs were used to intuitively reveal the synergistic influence of multivariate conditions variables on pretreatment effect to obtain better economic benefits and energy consumption indicators for DES pretreatment. The results showed that HBD hydrophilic ability, HBD polarity, HBD acidity, HBD ability to form hydrogen bonds, molar ratio of HBD to choline chloride and pretreatment severity had great influence on the Choline chloride based deep eutectic solvents pretreatment effect.

Reusing biogas slurry (BS) in agricultural drip irrigation systems may provide a solution to deal with the adverse environmental impacts of applying BS. Biofouling and scaling are two leading issues in drip irrigation emitters. This study investigated a practice that applied electromagnetic fields (EMFs) to control biofilms and scales. The bacterial communities and mineral precipitations in the clogging substances of emitters were determined. Results showed that EMFs inhibited the growth of microbes, and influenced BS physicochemical parameters. Consequently, EMFs shifted the bacterial communities with reduced diversities. Network analyses revealed that bacterial species under EMFs treatments showed lower average connectivities and simpler interactions, which were responsible for the decreases of extracellular polymers substances (EPS). Moreover, EMFs treatments not only reduced the carbonates in emitters, but also prevented the depositions of phosphates, silicates, and quartzes. EMFs also had impacts on the lattice parameters and crystal volumes of carbonates. In addition, the changes in bacterial communities and EPS contents were associated with the reductions of various minerals. Accordingly, EMFs effectively mitigated biofilms and scales with the fixed clogging substances reduced by 29.1–53.8 %. These findings demonstrated that applying EMFs is an effective anti-biofouling and anti-scaling treatment with potential applications in BS irrigation systems.

Sensitivity analysis of a model can identify key variables affecting the performance of the model. Uncertainty analysis is an essential indicator of the precision of the model. In this study, the sensitivity and uncertainty of the Long-Term Hydrologic Impact Assessment-Low Impact Development 2.1 (L-THIA-LID 2.1) model in estimating runoff and water quality were analyzed in an urbanized watershed in central Indiana, USA, using Sobol′‘s global sensitivity analysis method and the bootstrap method, respectively. When estimating runoff volume and pollutant loads for the case in which no best management practices (BMPs) and no low impact development (LID) practices were implemented, CN (Curve Number) was the most sensitive variable and the most important variable when calibrating the model before implementing practices. When predicting water quantity and quality with varying levels of BMPs and LID practices implemented, Ratio_r (Practice outflow runoff volume/inflow runoff volume) was the most sensitive variable and therefore the most important variable to calibrate the model with practices implemented. The output uncertainty bounds before implementing BMPs and LID practices were relatively large, while the uncertainty ranges of model outputs with practices implemented were relatively small. The limited observed data in the same study area and results from other urban watersheds in scientific literature were either well within or close to the uncertainty ranges determined in this study, indicating the L-THIA-LID 2.1 model has good precision.

(Pb0.97La0.02)(Zr75Sn0.25-x Tix)O3 (0.08 ≤ x ≤ 0.11) ceramics at morphotropic phase boundary (MPB) were fabricated by the conventional solid–state reactions, and the major phase was changed from tetragonal antiferroelectric phase to rhombohedral ferroelectric phase (AFET-FER) as the increase of Ti/Sn. The dielectric properties in original states and the poled states were systematically studied. Dielectric constant of the electric-induced AFET poled states was greater than the virgin state, then approached and become less as the compositions moved to FER phase. Moreover, there was a dielectric anomaly for FER poled sample on heating, but not observed in cooling cycle and AFET sample, which was a FE-AFE phase transition confirmed by dielectric constant as functions of temperature and electric field, and the abnormal dielectric behavior become more obviously with electric field increasing. This results are useful to understand the dielectric properties and phase transition in AFE and FE materials.

A decision support tool, which links a hydrologic/water quality model (L-THIA-LID 2.1) with optimization algorithms (AMALGAM) using a computational efficiency framework (MLSOPT), was developed to optimally implement BMPs and LID practices to reduce runoff and pollutant loads. The decision support tool was applied in the Crooked Creek watershed, Indiana, USA. For initial expenditures on practices, the environmental benefits increased rapidly as expenditures increased. However, beyond certain expenditure levels, additional spending did not result in noticeable additional environmental impacts. Compared to random placement of practices, the optimization strategy provided 3.9-7.7 times the level of runoff/pollutant load reductions for the same expenditures. To obtain the same environmental benefits, costs of random practices placement were 4.2-14.5 times the optimized practice placement cost. The decision support tool is capable of supporting decision makers in optimally selecting and placing BMPs and LID practices to obtain maximum environmental benefits with minimum costs. A decision support tool was developed to optimally implement BMPs/LID practices.Decision support tool was applied at Crooked Creek watershed in Indiana, USA.Decision support tool is capable of optimally implementing BMPs/LID practices.

Low-impact development (LID) practices are gaining popularity as an approach to manage stormwater close to the source. LID practices reduce infrastructure requirements and help maintain hydrologic processes similar to predevelopment conditions. Studies have shown LID practices to be effective in reducing runoff and improving water quality. However, little has been done to aid decision makers in selecting the most effective practices for their needs and budgets. The long-term hydrologic impact assessment LID model was applied to four neighborhoods in Lafayette, Indiana using readily available data sources to compare LID practices by analyzing runoff volumes, implementation cost, and the approximate period needed to achieve payback on the investment. Depending on the LID practice and adoption level, 10-70% reductions in runoff volumes could be achieved. The cost per cubic meter of runoff reduction was highly variable depending on the LID practice and the land use to which it was applied, ranging from around $3 to almost $600. In some cases the savings from reduced runoff volumes paid back the LID practice cost with interest in less than 3 years, while in other cases it was not possible to generate a payback. Decision makers need this information to establish realistic goals and make informed decisions regarding LID practices before moving into detailed designs, thereby saving time and resources.

(Pb0.97La0.02) (Zr0.5Sn0.5−xTix)O3 (0.04

Deep eutectic solvent (DES) has been considered as a novel green solvent for lignocellulosic biomass pretreatment. The efficiency of DES pretreatment is affected by the synergy of various process parameters. The study of effect of DES physicochemical properties and pretreatment reaction conditions on the mechanism of lignocellulose biomass fractionation was of great significance for the development of biomass conversion. Form the view of process control, this review summarized recent advances in DES pretreatment, analyzed the challenges, and prospected the future development of this research field.

As an urban fringe district, the Ecorse River watershed is faced with increased impervious area caused by urban expansion. Effects of Green Infrastructure (GI) practice implementation were simulated with the Long-Term Hydrologic Impact Assessment-Low Impact Development 2.1 model (L-THIA-LID 2.1). Suitable locations of each GI practice were identified, based on construction condition requirements and demand on GI practices in the study area. Using the data of 2011, various GI practice combination scenarios were explored according to the cost-efficiency of each GI practice. GI practice implementation scenarios in 2050 were also simulated based on projected land use and rainfall data. Results show that grassed swales, rain barrels (residential areas) and dry ponds were the top three most cost-efficient GI practices, with the cost at $1.5/m³/yr, $3.0/m³/yr and $3.4/m³/yr, respectively. Green roofs with rain cisterns (industrial and commercial area) were the most expensive GI practices, with the cost at $92.9/m³/yr. With the increase of investment in GI practices, the changing curves of the annual runoff volume, Total Nitrogen (TN) load and Total Phosphorus (TP) load reduction ratios match the law of diminishing marginal utility. The scenario with grassed swales, rain barrels, dry ponds and porous pavement would be the most cost-efficient scenario for runoff water quantity reduction. In addition, the scenario with additional wet ponds would be the most cost-efficient one for TN load and TP load reduction. GI practices in each scenario for expected 2050 conditions show better effectiveness on water quantity and quality management.

Agricultural conservation practices, or agricultural best management practices (BMPs), can reduce nutrient loading and help address harmful algal blooms (HABs). HABs in the western basin of Lake Erie, which are largely caused by phosphorus losses from the Maumee River watershed, are critical in the recent years. In this study, a new BMP cost tool was developed. Then the Soil and Water Assessment Tool (SWAT) and the new BMP cost tool were integrated to explore efficiencies and cost-effectiveness of BMPs in an agricultural catchment of the Maumee River watershed with various scenarios. The scenarios included individual BMPs applied in 100% of suitable areas, individual BMPs targeting Dissolved Reactive Phosphorus (DRP) and Total Phosphorus (TP) critical areas, and BMPs implemented in series. In addition, a cost-effective approach for the selections and placements of BMPs in agricultural watersheds was developed as an alternative to running complex optimization tools that are not applicable to large watersheds. The cost-effective approach applied BMPs based on cost-effectiveness rankings starting from the most cost-effective one. Results showed that: (1) BMPs implemented in series, which reduced pollutant loads more than individual BMPs, were not as cost-effective as some individual BMPs; (2) among all scenarios, filter strips targeting DRP/TP critical areas were the most cost-effective in reducing yearly/spring DRP/TP losses; (3) to obtain the watershed management plan goal of reducing March-July DRP/TP losses by 40%, implementing BMPs one by one in critical areas based on the cost-effectiveness rankings of individual BMPs in DRP/TP critical areas was the most cost-effective; and (4) the simulation results, modeling tools, and cost-effective approach can help create agricultural BMP strategies to cost-efficiently improve water quality.

The property of piezoelectric material was one of the keys to optimize energy harvester based on piezoelectric effect. In this paper, the relation between the parameters of piezoelectric material and the performance of circular diaphragm energy harvester was studied. Theoretical analysis and idiographic experiment were combined to estimate the dependence of output power on the material parameters: piezoelectric coefficient d 33 and dielectric constant e. The results show piezoelectric material with high-d 33 and low-e was good for increasing the output power of energy harvester, and the influence of piezoelectric coefficient is more obvious than that of dielectric constant. Among soft PZT, material PZT-51 could best fit energy harvesting. By optimizing PZT material, the energy harvester using single piezoelectric circular diaphragm could generate a maximum power of 9.08 mW for a matching load about 45 kΩ and a tip mass of 30 gat its resonant frequency of 178 Hz.

North China Plain is one of the most important grain-producing areas in China. Because of unevenly distributed precipitation in this semi-arid area, crop production largely relies on underground blue water (UBW) to irrigate, overexploitation of which causes a lot of environmental problems. In this paper, we first defined the representative division of winter wheat irrigation water production efficiency with a support vector machine and genetic algorithm coupling algorithm, then established a model for evaluating the comparative advantage of UBW production efficiency by combining the effective precipitation with the UBW depth, calculated its value in each city, and further proposed the reasonable irrigation water requirement and its distribution under different grain reserves at the targeting year. The result showed that when the typical precipitation (P) is 25% in a targeting year, there is no need to irrigate with UBW; when P = 50%, supplying 5% of total winter wheat production (TWP) could save 15% of UBW; when P = 75%, supplying 5% of TWP could save 11% of UBW; and when P = 75%, supplying 10% of TWP could save up to 28% of UBW.

Using reclaimed water has become one of the most effective ways to solve the problem of urban water shortage. Using mixtures of sodium bentonite and clay to reduce infiltration is an important safeguard measure to meet the need of groundwater recharge and water quality safety. The microscopic structure of sodium bentonite was studied with environmental scanning electron microscopy. The effect of different mix ratios of sodium bentonite and clay on the performance of reducing infiltration was studied with constant head infiltration experiments and adsorption of ammonium and phosphate with the batch method. The results showed that the dry particles of sodium bentonite had lamellar and compact structure, after absorbing water, and both the number and size of pores gradually reduced to become uniform distributions. With the increase of bentonite mix ratio (10–20 % of the total dry weight), the infiltration coefficient of the mixed materials decreased exponentially (R2 = 0.95). Linear, Freundlich, and Langmuir equations could be used to describe adsorption of N/P on the mixed materials. There were significant correlations between adsorption parameters (Sm and MBC) and bentonite mix ratio. The effect of removing ammonium with mixtures was better than that of phosphate. Considering synthetically the capability of reducing infiltration and decontamination, a mixture of 19 % bentonite and 81 % clay was a suitable model in the Yongding River in Beijing plain segment.

The adverse influence of urban development on hydrology and water quality can be reduced by applying best management practices (BMPs) and low impact development (LID) practices. This study applied green roof, rain barrel/cistern, bioretention system, porous pavement, permeable patio, grass strip, grassed swale, wetland channel, retention pond, detention basin, and wetland basin, on Crooked Creek watershed. The model was calibrated and validated for annual runoff volume. A framework for simulating BMPs and LID practices at watershed scales was created, and the impacts of BMPs and LID practices on water quantity and water quality were evaluated with the Long-Term Hydrologic Impact Assessment-Low Impact Development 2.1 (L-THIA-LID 2.1) model for 16 scenarios. The various levels and combinations of BMPs/LID practices reduced runoff volume by 0 to 26.47%, Total Nitrogen (TN) by 0.30 to 34.20%, Total Phosphorus (TP) by 0.27 to 47.41%, Total Suspended Solids (TSS) by 0.33 to 53.59%, Lead (Pb) by 0.30 to 60.98%, Biochemical Oxygen Demand (BOD) by 0 to 26.70%, and Chemical Oxygen Demand (COD) by 0 to 27.52%. The implementation of grass strips in 25% of the watershed where this practice could be applied was the most cost-efficient scenario, with cost per unit reduction of $1m3/yr for runoff, while cost for reductions of two pollutants of concern was $445 kg/yr for Total Nitrogen (TN) and $4871 kg/yr for Total Phosphorous (TP). The scenario with very high levels of BMP and LID practice adoption (scenario 15) reduced runoff volume and pollutant loads from 26.47% to 60.98%, and provided the greatest reduction in runoff volume and pollutant loads among all scenarios. However, this scenario was not as cost-efficient as most other scenarios. The L-THIA-LID 2.1 model is a valid tool that can be applied to various locations to help identify cost effective BMP/LID practice plans at watershed scales.

Drip irrigation frequency has important impacts on crop growth, soil moisture, nutrient, salinity and sub- stances' accumulation in the irrigation system as well as drip irrigation emitter clogging. However, previous studies on reasonable drip irrigation frequency merely focused on crop yield and quality, soil water and salinity transporting, neglecting its impact on the high-efficiency operation of the drip irrigation system. Studies on reasonable reclaimed water drip irrigation frequency were more insufficient. There- fore, the drip irrigation emitter clogging experiment using reclaimed water was accomplished in the wastewater treat- ment plant, and then, the effects of different irrigation fre- quencies, including once/2 days (IF 1/2 ), once/4 days (IF 1/4 ), once/8 days (IF1/8) and once/16 days (IF1/16), on dynamic emitters' outflows and biofilms' growth were studied. The results showed that emitter clogging degrees increased with shorter drip irrigation interval, mainly because that dis- charge ratio variation (Dra) and Christiansen uniformity coefficient (CU) both decreased. After the system accumu- latively run 540 h, the smallest Dra and CU were observed in high-frequency drip irrigation treatment (IF 1/2 ) as 30.98

Biofilms, abundantly attached on the surfaces of multiple media (such as pebbles and aquatic plants) in rivers or lakes reusing reclaimed water (RW), are of great significance to contaminants’ self-purification of water bodies. In this paper, the nitrogen and phosphate adsorption characteristics of such biofilms were studied by the batch method, using biofilms cultivated under an outdoor simulative process. Two types of RW treated by anaerobic-anoxic-oxic process (A2/O) and cyclic activated sludge technology (CASS), and surface water (NW) were chosen as the experimental water bodies. And the glasses of surface roughness of 0.1, 1.0, and 10 μm, respectively, were used as the substrates, where the biofilms adhere to them. The results indicated that the isothermal adsorption of biofilms for ammonia nitrogen and phosphates was proved to conform to the Langmuir and the Freundlich equation, whereas the adsorption capacity was significantly lower than that of soils and sediments limited by the pore structure and surface area. There were also significant differences between the adsorption behaviors. The distribution coefficients were ranked as K dCASS > K dNW > K dA 2 /O, and the maximum adsorption capacities (S m), under these conditions were ranked as S mA 2 /O > S mNW > S mCASS, while other parameters did not change regularly. Extracellular polymers ( $$R^{ 2}_{\text{N}}$$ = 0.95**, $$R^{ 2}_{\text{p}}$$ = 0.84**), iron oxides ( $$R^{ 2}_{\text{N}}$$ = 0.86**, $$R^{ 2}_{\text{p}}$$ = 0.68*), and aluminum oxides ( $$R^{ 2}_{\text{N}}$$ = 0.95**, $$R^{ 2}_{\text{p}}$$ = 0.81**) in the biofilms had a significant impact on the S m for ammonia and phosphates. The roughness of media surfaces also had a considerable influence on the S m, which was in the order of S m10μm > S m0.1μm > S m1.0μm, whereas other parameters did not change regularly. The research aimed to provide theory reference for in situ decontamination of RW in rivers or lakes.

Nutrient loading from the Maumee River watershed is a significant reason for the harmful algal blooms (HABs) problem in Lake Erie. The nutrient loading from urban areas needs to be reduced with the installation of green infrastructure (GI) practices. The Long-Term Hydrologic Impact Assessment-Low Impact Development 2.1 (L-THIA-LID 2.1) model was used to explore the influences of land use (LU) and climate change on water quantity and quality in Spy Run Creek watershed (SRCW) (part of Maumee River watershed), decide whether and where excess phosphorus loading existed, identify critical areas to understand where the greatest amount of runoff/pollutants originated, and optimally implement GI practices to obtain maximum environmental benefits with the lowest costs. Both LU/climate changes increased runoff/pollutants generated from the watershed. Areas with the highest runoff/pollutant amount per area, or critical areas, differed for various environmental concerns, land uses (LUs), and climates. Compared to optimization considering all areas, optimization conducted only in critical areas can provide similar cost-effective results with decreased computational time for low levels of runoff/pollutant reductions, but critical area optimization results were not as cost-effective for higher levels of runoff/pollutant reductions. Runoff/pollutants for 2011/2050 LUs/climates could be reduced to amounts of 2001 LU/climate by installation of GI practices with annual expenditures of $0.34 to $2.05 million. The optimization scenarios that were able to obtain the 2001 runoff level in 2011/2050, can also reduce all pollutants to 2001 levels in this watershed.

Drip irrigation is the most effective and reliable method for reclaimed water irrigation. The water usually contains a lot of suspended particles, metal salt ions, organisms and microbial communities, which will enhance the possibility of emitter clogging or more complex clogging mechanism. Emitter clogging has become one of the key problems to the application and popularization of the drip irrigation technology. In this paper, we selected four kinds of pressure-compensating emitters and four kinds of non-pressure-compensating emitters, and executed the experiment of drip irrigation with on-site reclaimed water treated with cyclic activated sludge system (CASS). The emitter discharge ratio variation (Dra), coefficient of uniformity (CU) and clogging rate distribution were analyzed to evaluate the emitter clogging characteristics after eliminating the effect of temperature and pressure on the emitter outflow by data correction. The results showed that Dra and CU varied in three periods as system operation. The beginning of experiment was the fluctuated balance period, Dra and CU recurrent fluctuated in 5 %, and the emitters clogged at some spots after the system run 36–48 h. Then the two parameters varied linearly in 60–108 h, tuning into the initiate linear period, as the non-pressure-compensating emitters got an obvious linear change than the pressure-compensating ones with the gradient changed from −0.094 to 0.042 and −0.073 to 0.047, respectively. Some of the emitters have a significant difference on these two parameters at this stage. After the restarting in the second year, Dra and CU decreased sharply. The maximum decrement was, respectively, 9.6 and 10.7 %. Then they varied in line with a greater slope degree as all emitters reached the significant level, the gradient ranges were −0.176 to 0.115 and −0.216 to 0.117, respectively. This stage was called the accelerated linear period. Seriously clogged and completely clogged emitters appeared, and both Dra and CU dropped down to 38.7 and 41.5 %. Various degrees of clogged emitters often emerged in the end part of lateral at first then propelled to the head gradually, the completely clogged emitters in the end accounted for more than 73.0 % when the system run 540 h. Comprehensively considered, the pressure-compensating emitters and cusp-shaped saw-tooth non-pressure-compensating emitters with short flow path are recommended in reclaimed water drip irrigation. These researches are aimed to provide references explaining the emitter clogging mechanism of reclaimed water drip irrigation as well as its technological application and popularization.

A CubeSat is a type of miniaturized and modular satellite designed for space research or technology demonstration. By filling the unused capacity of major launch vehicles, CubeSats significantly lower the cost of entry to the space. To reduce the energy loss at the solar panel coverglass on CubeSats, the authors investigated the potential of the biomimetic moth-eye antireflection (MEAR) technique which features a gradient refractive index. A novel fabrication process combining nanosphere lithography, reactive-ion etching, and dry oxidation for patterning glass with moth-eye structures was reported that allows for the production of well-defined nanopillars with tunable sidewall profiles. The thermal annealing treatment of colloidal particles was introduced for making MEAR structures for which partial deformation of nanospheres was achieved. The broadband and omnidirectional antireflective performance of fabricated glasses was experimentally demonstrated by using a spectrophotometer and ellipsometer. A significant 10% decrease of reflectance throughout the measured spectral range was observed at a high incident angle of 75°.A CubeSat is a type of miniaturized and modular satellite designed for space research or technology demonstration. By filling the unused capacity of major launch vehicles, CubeSats significantly lower the cost of entry to the space. To reduce the energy loss at the solar panel coverglass on CubeSats, the authors investigated the potential of the biomimetic moth-eye antireflection (MEAR) technique which features a gradient refractive index. A novel fabrication process combining nanosphere lithography, reactive-ion etching, and dry oxidation for patterning glass with moth-eye structures was reported that allows for the production of well-defined nanopillars with tunable sidewall profiles. The thermal annealing treatment of colloidal particles was introduced for making MEAR structures for which partial deformation of nanospheres was achieved. The broadband and omnidirectional antireflective performance of fabricated glasses was experimentally demonstrated by using a spectrophotometer and ellipsometer. A sign...

The depth of the flow path of a drip irrigation emitter can affect the anti-clogging ability of a drip irrigation system by changing the flow velocity distribution and material transportation process. In order to evaluate these effects, in this paper a drip irrigation experiment using reclaimed water was performed, and four types of emitters with four flow path depths were chosen for the experiment. The dynamic outflow changes of the emitters were tested with constant intervals and the surface topographical characteristics of biofilms at the inlets and outlets of emitters and the inner lateral walls were tested with the 3D-WLSI (3D white-light scanning interferometer). Thus, the effect of flow path depth on emitter clogging was analysed. The results showed that emitter clogging with different degrees in the 204 hrs was observed. The discharge ratio variation (Dra) and coefficient of uniformity (CU) of emitters all slightly decreased with fluctuant changes. Moreover, clogged emitters were more likely to occur at the end part of the lateral, which revealed obvious difference among emitters with different flow path depths. The average thickness (Sd) and relative average thickness (RSd) of biofilms increased with deeper flow path, while surface topographical characteristics of biofilms varied from smooth to rough. On the other hand, the average thickness and relative thickness of the biofilms at different positions of the lateral represented the order as: Sd head

Realizing the internal flow visualization inside the drip irrigation emitter is the basis of optimizing the labyrinth path structure and promoting its anti-clogging capability. The Computational Fluid Dynamics (CFD) method has become an effective approach to research the water movement in the labyrinth path of the drip irrigation emitter. In this paper, the standard k-epsilon model and the Large Eddy Simulation method (LES) were applied to analyze the flow characteristic in the drip irrigation emitter. The results showed that the LES model was more effective to simulate the flow characteristics in the flow path of drip irrigation emitters. Based on this model, the energy dissipation mechanism was explained with the velocity and pressure values from local regions to the whole flow path, and the study of the flow path anti-clogging performance was carried out by way of analyzing the velocity distribution characteristics in different cross sections of the same structure unit. (C) 2011 Elsevier Ltd. All rights reserved.