Comparison of isotope-based linear and Bayesian mixing models in determining moisture recycling ratio

Stable water isotopes are natural tracers quantifying the contribution of moisture recycling to local precipitation,i.e.,the moisture recycling ratio,but various isotope-based models usually lead to different results,which affects the accuracy of local moisture recycling.In this study,a total of 18 stations from four typical areas in China were selected to compare the performance of isotope-based linear and Bayesian mixing models and to determine local moisture recycling ratio.Among the three vapor sources including advection,transpiration,and surface evaporation,the advection vapor usually played a dominant role,and the contribution of surface evaporation was less than that of transpiration.When the abnormal values were ignored,the arithmetic averages of differences between isotope-based linear and the Bayesian mixing models were 0.9%for transpiration,0.2%for surface evaporation,and–1.1%for advection,respectively,and the medians were 0.5%,0.2%,and–0.8%,respectively.The importance of transpiration was slightly less for most cases when the Bayesian mixing model was applied,and the contribution of advection was relatively larger.The Bayesian mixing model was found to perform better in determining an efficient solution since linear model sometimes resulted in negative contribution ratios.Sensitivity test with two isotope scenarios indicated that the Bayesian model had a relatively low sensitivity to the changes in isotope input,and it was important to accurately estimate the isotopes in precipitation vapor.Generally,the Bayesian mixing model should be recommended instead of a linear model.The findings are useful for understanding the performance of isotope-based linear and Bayesian mixing models under various climate backgrounds.

Heat transfer model for microwave hot in-place recycling of asphalt pavements

In order to solve for temperature fields in microwave heating for recycling asphalt mixtures, a two-dimensional heat transfer model for the asphalt mixtures within the heating range is built based on the theory of unsteady heat conduction. Four onedimensional heat transfer models are established for the asphalt mixtures outside the heating range, which are simplified into four half-infinite solids. The intensity of the radiation electric field is calculated through experiment by using heating water loads. It is suggested that the mathematical model of boundary conditions can be established in two ways, which are theoretical deduction and experimental reverse. The actual temperature field is achieved by fitting temperatures of different positions collected in the heating experiment. The simulant temperature field, which is solved with the Matlab PDE toolbox, is in good agreement with the actual temperature field. The results indicate that the proposed models have high precision and can be directly used to calculate the temperature distribution of asphalt pavements.

A New Model of Recycling Agricultural Production

[Objective] The aim was to research production model of recycling agricul- ture. [Method] The production model of recycling agriculture integrating planting and breeding was explored on basis of pig raising, and maize and peanut planting, with consideration of existing problems of planting and breeding integration in China. [Result] Ecological and economic benefits of pig farms and planting bases increased significantly, and all indices improved in different degrees. [Conclusion] The research provides valuable references for pig raising in China.

Prediction Model-based Multi-objective Optimization for Mix-ratio Design of Recycled Aggregate Concrete

The prediction model for mechanical properties of RAC was established through the Bayesian optimization-based Gaussian process regression(BO-GPR)method,where the input variables in BO-GPR model depend on the mix ratio of concrete.Then the compressive strength prediction model,the material cost,and environmental factors were simultaneously considered as objectives,while a multi-objective gray wolf optimization algorithm was developed for finding the optimal mix ratio.A total of 730 RAC datasets were used for training and testing the predication model,while the optimal design method for mix ratio was verified through RAC experiments.The experimental results show that the predicted,testing,and expected compressive strengths are nearly consistent,illustrating the effectiveness of the proposed method.

Monte Carlo Simulation-based Decision-making Model for the Water Conservation and Intermediate Water Recycling of Conservationminded Buildings

Through analyzing the life cycle cost of the water conservation and intermediate water application project of conservation-minded buildings,net present value(NPV) was applied as the index to establish the life cycle economic decision-making model.Monte Carlo simulation was used in demonstration cases,modeling analysis of water-saving projects in conservation-minded and traditional buildings verified rationality and practicability of this model and simulation method.It was to provide a referential and operable method for the decision-making of conservation-minded construction projects,as well as a scientific approach and theoretic basis for the precise decision-making of government organs,decision-making departments and developers.

Recycling Strategy and Recyclability Assessment Model Based on the Artificial Neural Network

Now, a rapidly growing concern for the environmental protection and resource utilization has stimulated many new activities in the in dustrialized world for coping with urgent environmental problems created by the steadily increasing consumption of industrial products. Increasingly stringent r egulations and widely expressed public concern for the environment highlight the importance of disposing solid waste generated from industrial and consumable pr oducts. How to efficiently recycle and tackle this problem has been a very impo rtant issue over the world. Designing products for recyclability is driven by environmental and economic goals. To obtain good recyclability, two measures can be adopted. One is better recycling strategy and technology; the other is design for recycling (DFR). The recycling strategies of products generally inclu de: reuse, service, remanufacturing, recycling of production scraps during the p roduct usage, recycle (separation first) and disposal. Recyclability assessment is a very important content in DFR. This paper first discusses the content of D FR and strategies and types related to products recyclability, and points out th at easy or difficult recyclability depends on the design phase. Then method and procedure of recyclability assessment based on ANN is explored in detail. The pr ocess consists of selection of the ANN input and output parameters, control of t he sample quality and construction and training of the neural network. At la st, the case study shows this method is simple and operative.

Environmental and economic benefit of recycling model of packaging waste:a case study on aluminum

In order to achieve sustainable utilization of natural resources, save energy and protect environment and ecosystem, it is important for a region or a nation to develop and implement a viable waste recycling model from both theoretical and practical point of view. Some packaging recycling models operated in developed countries are introduced in this article. Aluminium can recovery and recycling is emphasized. Cost effective, economic and environmental benefit of different models are compared and analyzed. The result shows that all recycling models have their characteristics due to the initial purpose of recovery and the situation of the implementing country. However, all the models contribute to the reduction of municipal solid waste disposal and resources conservation.

Pricing Game Model of Wasted Clothing Recycling and Remanufacturing Based on Government Subsidy

In the global environment of pursuing resource regeneration and green environmental protection, more and more wasted clothing need to be solved. In order to make full use of the wasted clothing and save land and soil resources, an idea of wasted clothing's recycling and remanufacturing is put forward. In the new idea a pricing game model is established basing on Stacklberg differential game theory between traditional and remanufactured clothing. In this model, the differences in consumers' willingness to pay and the government's subsidies are considered. Government's optimal subsidy are obtained which ensure not only the interests of manufacturers but also environmental reputation and maximum social benefits. The study is helpful to push the wasted clothing's recycling and remanufacturing plan. It makes some index more precise quantification as government's subsidy, manufacturers and the social benefits. Government and manufactures can make the detailed cooperation plan reference to it.

Global Analysis of Beddington-DeAngelis Type Chemostat Model with Nutrient Recycling and Impulsive Input

In this paper, a Beddington-DeAngelis type chemostat model with nutrient recycling and impulsive input is considered. Except using Floquet theorem, introducing a new method combining with comparison theorem of impulse differential equation and by using the Liapunov function method, the sufficient and necessary conditions on the permanence and extinction of the microorganism are obtained. Two examples are given in the last section to verify our mathematical results. The numerical analysis shows that if only the system is permanent, then it also is globally attractive.

Development and Evaluation of Innovative Recycling Intervention Program Using the Health Belief Model (HBM)

The purpose of this study was to assess the effectiveness of interventions based on health promotion theories in changing the recycling behavior of the targeted population. The study focused on the development and evaluation of innovative recycling education programs that address energy recovery, recycling, and waste management. The study applied Health Belief Model-(HBM) as an approach to motivate recycling behaviors and to evaluate the impact of the applied approaches on recycling set-out rates and participation. A total of 102 households from a Midwestern city participated in this study. The study was conducted over a period of six months. A Likert scale questionnaire was used to collect data on recycling and environmental knowledge, skills, behavior, and attitudes. The other set of data was the weight of recyclables that was obtained at each participant’s curb four times over the six months period of interventions. Results indicated a significant increase in average set out rates of recyclables among HBM participants (21.34 lbs. pre-test to 59.3 lbs. post-test). It was concluded that HBM educational approaches can be effective in motivating recycling. This study signifies the need for renewed effort in motivating individuals, households or businesses to recycle. Not every community or city significantly participates in recycling. Innovative strategies as well the application of approaches in the theories of behavioral change can positively influence recycling and overall waste reduction behaviors.

Recycling economy development model and macroeconomic policy

To develop circular economy is an important way to implement sustainable development strategies. This paper discusses the theoretical origin of the circular economy, and clarifies the mechanism development of circular economy. Combined with the status quo of China＇s economic development, it analyzed the facing problems in the development of circular economy. Our country has carried on the positive exploration and practice in the use of the concept of circular economy to promote sustainable development, and China＇s circular economy is transferred from the start-up phase to promote the establishment of policy mechanisms. Circular economy strategy will also begin to implement in some of China＇s mega-cities. Faced with the arrival of the circular economy, we should look to a higher level up to explore how people should take effective measures to turn challenges into opportunities.

Modelling Recycling Targets:Achieving a 50%Recycling Rate for Household Waste in Denmark

Within the European Union (EU) a paradigm shift is currently occurring in the waste sector, where EU waste directives and national waste strategies are placing emphasis on resource efficiency and recycling targets. The most recent Danish resource strategy calculates a national recycling rate of 22% for household waste, and sets an ambitious goal of a 50% recycling rate by 2020. This study integrates the recycling target into the FRIDA model to project how much waste and from which streams should be diverted from incineration to recycling in order to achieve the target. Furthermore, it discusses how the existing technological, organizational and legislative frameworks may affect recycling activities. The results of the analysis show that with current best practice recycling rates, the 50% recycling rate cannot be reached without recycling of household biowaste. It also shows that all Danish municipalities will need to make efforts to recover all recyclable fractions, and that the increased recycling efforts of only selected municipalities will not be sufficient to reach the target.

Impact of recycling improvement on the life cycle of phosphorus

Access to natural resources is increasingly more difficult and more costly, partly due to their economic significance and to continuous increase of their global consumption in the recent years. In the case of phosphorus (P), which is a critical raw material, geological distribution of its primary nonrenewable source (phosphate rock) is concentrated in particular regions leading to high supply risk of this raw material. In Europe (EU-28), where phosphate rock reserves are scarce, import of phosphorus has been the main source of supply. It means that Europe relies highly on the foreign exporters. From decision makers' perspective, recycling of phosphorus was taken into account as one of the possible solutions to decrease the dependence on imports and extraction of reserves. The question, however, is to what extent does the recycling of phosphorus help in reducing the reliance on typical supply resources? Hence, the main objective of this paper is to quantify the dynamic flow of phosphorus and show potential benefits of its recycling in Europe. This article presents a system dynamics model for representation of the element P flow and helps to quantify to what extent the recycled phosphorus could mitigate its criticality. Analysis of the results supports previous studies indicating the high reliance ofEU on P imports, estimating around 96% as the reliance percentage on imports. The results imply that improving P recycling has the potential to decrease the level of P imports to a certain extent, which may reach 79%.

Mathematical models for properties of mortars with admixtures and recycled fine aggregates from demolished concretes

In order to expand the engineering application of recycle aggregate mortars （RAM） with aggregates from demolished concretes, the models for the properties of RAM and the replacement rate of these recycled fine aggregates were proposed. First, different kinds of mathematical models for the basic properties （compressive strength, water retention rate, and consistency loss） of RAM with two kinds of admixtures, thickening powders （TP） and self-made powdery admixtures （SSCT） designed for RAM, and the replacement rates were established, while the average relative errors and relative standard errors of these models were calculated. Additionally, the models and their error analyses for the curves of drying shrinkage and curing time of RAM ＋ SSCT at different replacement rates were put forward. The results show that polynomial functions should be used to calculate the basic properties of RAM ＋ TP and RAM ＋ SSCT at different replacement rates. In addition, polynonfial functions are the most optimal models for the sharp shrinkage sections in the curves of drying shrinkage-curing time of RAM ＋ SSCT, while exponential functions should be used as the models for the slow shrinkage sections and steady shrinkage sections.

Quantifying the Spatial Characteristics of the Moisture Transport Affecting Precipitation Seasonality and Recycling Variability in Central Asia

Moisture contribution and transport pathways for Central Asia(CA)are quantitatively examined using the Lagrangian water cycle model based on reanalysis and observational data to explain the precipitation seasonality and the moisture transport variation during 1979-2015.Westerly-related(northwesterly and westerly)transport explains 42%of CA precipitation and dominates in southwest CA,where precipitation is greatest in the cold season.Southeast CA,including part of Northwest China,experiences its maximum precipitation in the warm season and is solely dominated by southerly transport,which explains about 48%of CA precipitation.The remaining 10%of CA precipitation is explained by northerly transport,which steadily impacts north CA and causes a maximum in precipitation in the warm season.Most CA areas are exposed to seasonally varying moisture transport,except for southeast and north CA,which are impacted by southerly and northerly transport year-round.In general,the midlatitude westerlies-driven transport and the Indian monsoon-driven southerly-related transport explain most of the spatial differences in precipitation seasonality over CA.Moreover,the contribution ratio of local evaporation in CA to precipitation exhibits significant interdecadal variability and a meridionally oriented tripole of moisture transport anomalies.Since the early 2000s,CA has experienced a decade of anomalously low local moisture contribution,which seems jointly determined by the weakened moisture contribution from midlatitudes(the Atlantic,Europe,and CA itself)and the enhanced contribution from high latitudes(West Siberia and the Arctic)and tropical areas(South Asia and the Indian Ocean).

Economy Analysis of a Recycle Model of End-of-Life Vehicle

In order to evaluate recycle economy of end-of-life vehicles quantitatively,an economy model based on a recycle model of end-of-life vehicles and recycle cost analysis. With a practical example of recycling engines of end-of-life vehicles ,the validity of the recycle economy model and good recycle economy of the end-of-life vehicle engine were justified. It is concluded that ① remanufacture-ability of the part or component of the vehicles; ② the organization and management level of a recycle corporation; ③ policies and regulations of the government are crucial factors to raise the recycle economy of the end-of-life vehicle.

Physical Model of Drying Shrinkage of Recycled Aggregate Concrete

We prepared concretes（RC0, RC30, and RC100） with three different mixes. The poresize distribution parameters of RAC were examined by high-precision mercury intrusion method（MIM） and nuclear magnetic resonance（NMR） imaging. A capillary-bundle physical model with random-distribution pores（improved model, IM） was established according to the parameters, and dry-shrinkage strain values were calculated and verified. Results show that in all pore types, capillary pores, and gel pores have the greatest impacts on concrete shrinkage, especially for pores 2.5-50 and 50-100 nm in size. The median radii are 34.2, 31, and 34 nm for RC0, RC30, and RC100, respectively. Moreover, the internal micropore size distribution of RC0 differs from that of RC30 and RC100, and the pore descriptions of MIM and NMR are consistent both in theory and in practice. Compared with the traditional capillary-bundle model, the calculated results of IM have higher accuracy as demonstrated by experimental verifi cation.

The Impacts of Agricultural Machinery Purchase Subsidies on Mechanized Crop Residue Recycling

Crop residue recycling can improve the quality of the cropland,and it has multiple economic and ecological benefits.However,such practice is with low adoption due to different constraints.In this paper,we use the survey data from Baoding,Hebei province,and use the probit model to explore how the agricultural machinery purchase subsidies affect the mechanized crop residue recycling.The results showed that several factors that affect farmers in adopting the practice of mechanized crop residue crop recycling.Among these factors,the cost of adopting such practice is significant.The agricultural machinery purchase subsidies can effectively reduce the cost of such practice,as well as promote mechanized crop residue recycling.The paper also proposed several actions in the future.They include increasing the subsidies on agricultural machinery purchase and increasing farmers' awareness on crop residue recycling.

Litterfall production modeling based on climatic variables and nutrient return from stands of Eucalyptus grandis Hill ex Maiden and Pinus taeda L.

Native grasslands in the Pampas of South America are increasingly being replaced by Eucalyptus and Pinus stands.The short rotation regimes used for the stands require high nutrient levels,with litterfall being a major source of nutrient return.To model the litterfall production using climatic variables and assess the nutrient return in 14-year-old Eucalyptus grandis and Pinus taeda stands,we measured litter production over 2 years,using conical litter traps,and monitored climatic variables.Mean temperature,accumulated precipitation,and mean maximum vapor pres-sure deficit at the seasonal level influenced litterfall produc-tion by E.grandis;seasonal accumulated precipitation and mean maximum temperature affected litterfall by P.taeda.The regression tree modeling based on these climatic vari-ables had great accuracy and predictive power for E.grandis(N=33;MAE(mean absolute error)=0.65;RMSE(root mean square error)=0.91;R^(2)=0.71)and P.taeda(N=108;MAE=1.50;RMSE=1.59;R^(2)=0.72).The nutrient return followed a similar pattern to litterfall deposition,as well as the order of importance of macronutrients(E.grandis:Ca>N>K>Mg>P;P.taeda:N>Ca>K>Mg>P)and micronutrients(E.grandis and P.taeda:Mn>Fe>Zn>Cu)in both species.This study constitutes a first approximation of factors that affect litterfall and nutrient return in these systems.

The Behavior of Recycled Concrete through the Application of an Isotropic Damage Model

The main goal of this paper is to describe the mechanical behavior of the CDW recycled concrete in compression, using an isotropic damage model adapted to the variation of the replacement rate of natural aggregates by recycled ones. The isotropic model by Mazars was used as a constitutive equation for the CDW concrete and its adjustment parameters, A and B, were written as quadratic polynomials according to the aggregates replacement rate. The model was evaluated for conventional and recycled concretes. For the latter ones, the aggregates replacement ratios evaluated were 50% and 100%. The results show good approximation between the analytical and numerical values obtained with the adapted isotropic damage model and experimental concrete results for both compressive and flexural strength.