Wood,an essential natural resource in human civilization,remains widely used despite advances in technology and material substitution.The surge in greenhouse gas emissions and environmental concerns accentuates the ne...Wood,an essential natural resource in human civilization,remains widely used despite advances in technology and material substitution.The surge in greenhouse gas emissions and environmental concerns accentuates the need for optimizing wood utilization.Material flow analysis is a powerful tool for tracking material flows and stocks,aiding resource management and environmental decision-making.However,the full extent of its methodological dimensions,particularly within the context of the wood supply chain,remains relatively unexplored.In this study,we delve into the existing literature on wood flow analysis,discussing its primary objectives,materials involved,temporal and spatial scales,data sources,units,and conversion factors.Additionally,data uncertainty,data reconciliation and crucial assumptions in material flow analysis are highlighted in this paper.Key findings reveal the significance of wood cascading and substitution effects by replacing non-wood materials,where they can reduce greenhouse gas emissions more than the natural carbon sink of forests and wood products.The immediate impact of short-term wood cascading might not be as robust as the substitution effect,with energy substitution showcasing better results than material substitution.However,it's crucial to note that these conclusions could experience significant reversal from a long-term and global perspective.Strategies for improving wood efficiency involve maximizing material use,advancing construction technologies,extending product lifespans,promoting cascade use,and optimizing energy recovery processes.The study underscores the need for standardized approaches in wood flow analysis and emphasizes the potential of wood efficiency strategies in addressing environmental challenges.展开更多
In the United States(US),the Surveillance,Epidemiology,and End Results(SEER)program is the only comprehensive source of population-based information that includes stage of cancer at the time of diagnosis and patient s...In the United States(US),the Surveillance,Epidemiology,and End Results(SEER)program is the only comprehensive source of population-based information that includes stage of cancer at the time of diagnosis and patient survival data.This program aims to provide a database about cancer incidence and survival for studies of surveillance and the development of analytical and methodological tools in the cancer field.Currently,the SEER program covers approximately half of the total cancer patients in the US.A growing number of clinical studies have applied the SEER database in various aspects.However,the intrinsic features of the SEER database,such as the huge data volume and complexity of data types,have hindered its application.In this review,we provided a systematic overview of the commonly used methodologies and study designs for retrospective epidemiological research in order to illustrate the application of the SEER database.Therefore,the goal of this review is to assist researchers in the selection of appropriate methods and study designs for enhancing the robustness and reliability of clinical studies by mining the SEER database.展开更多
Integrated traditional Chinese medicine(TCM)and Western medicine(WM)is a new medical science grounded in the knowledge bases of both TCM and WM,which then forms a unique modern medical system in China.Integrated TCM a...Integrated traditional Chinese medicine(TCM)and Western medicine(WM)is a new medical science grounded in the knowledge bases of both TCM and WM,which then forms a unique modern medical system in China.Integrated TCM and WM has a long history in China,and has made important achievements in the process of clinical diagnosis and treatment.However,the methodological defects in currently published clinical practice guidelines(CPGs)limit its development.The organic integration of TCM and WM is a deeper integration of TCM and WM.To realize the progression of"integration"to"organic integration",a targeted and standardized guideline development methodology is needed.Therefore,the purpose of this study is to establish a standardized development procedure for clinical practice guidelines for the organic integration of TCM and WM to promote the systematic integration of TCM and WM research results into clinical practice guidelines in order to achieve optimal results as the whole is greater than the sum of the parts.展开更多
The uniform design and response surface methodology （RSM） are applied to the multi-objective optimization of a 2-D mixed compression scramjet inlet. The set of experimental design points on the design space is selec...The uniform design and response surface methodology （RSM） are applied to the multi-objective optimization of a 2-D mixed compression scramjet inlet. The set of experimental design points on the design space is selected by the uniform design, and the inlet performance is analyzed by computational fluid dynamics （CFD）. Then complete quadratic polynomial response surface approximation models are constructed based on the performance analysis results and then used to replace theoriginal complex inlet performance model. The optimization is conducted using a multi-objective genetic algorithm NSGA-Ⅱ, and the Pareto optimal solution set is obtained. Results show that the uniform design and RSM can reduce the computational complexity of numerical simulation and improve the optimization efficiency.展开更多
English teaching methodology is the guidance in the process of English teaching. Based on the analysis of multi-source data, quantitative research and visualized analysis, we are aimed to analyze the frontier of Engli...English teaching methodology is the guidance in the process of English teaching. Based on the analysis of multi-source data, quantitative research and visualized analysis, we are aimed to analyze the frontier of English teaching methodology and try to explore the advanced English teaching methodology, improve the English teaching and provide the scientific data and appropriate methods for the local English teaching.展开更多
Sound transportation infrastructure is critical for economic development and sustainability. Pavement condition is a primary concern among agencies of the roadway infrastructure. Automation has become possible in rece...Sound transportation infrastructure is critical for economic development and sustainability. Pavement condition is a primary concern among agencies of the roadway infrastructure. Automation has become possible in recent years on collecting data and producing results for certain aspects of pavement performance, while challenges remain in several other categories, such as automated cracking survey. This paper reviews the technological advances on automated survey of pavements, and discusses the most recent breakthroughs by the team led by the author in using 3D laser imaging for capturing 1 mm surface images of pavements.展开更多
Oil from seeds of Diospyros lotus was extracted using a conventional method with two different solvents:hexane and petroleum ether. A central composite design with response surface methodology were used to optimize th...Oil from seeds of Diospyros lotus was extracted using a conventional method with two different solvents:hexane and petroleum ether. A central composite design with response surface methodology were used to optimize the process. A second-order polynomial equation was employed, and ANOVA was applied to evaluate the impact of various operating parameters including extraction temperature(x_1; 44.9–70.1 °C), extraction time(x_2;5.0–10.0 h) and solvent to solid ratio(x_3;11.6–28.4 mL g^(-1)), on oil yield. Experiments to validate the model showed decent conformity between predicted and actual values. Extraction conditions for optimal oil yield were 61 °C, 8.75 h extraction duration and 19.25 mL g^(-1) solvent to solid ratio. Under these conditions, the oil yield was predicted to be 5.1340%. Oil samples obtained were then analyzed using gas chromatography. The fatty acid composition revealed the major fatty acids to be oleic acid(C18:1) and linoleic acid(C18:2). The analysis of oil also demonstrated a decent ratio between omega-3 and omega-6 fatty acids. The structure of seeds was imaged using scanning electron microscopy. Oil quality was analyzed thermogravimetrically and by Fourier transform infrared spectroscopy. The assigned nutritional features of the D. lotus oil suggested that it can be used as an edible oil in pharmaceutical and food industry in the future.展开更多
Large scale open cut coal mining operations have significant impacts to groundwater in surrounding areas in both active and post-mining phases. The prediction of water inflows into a surface mine excavation is one of ...Large scale open cut coal mining operations have significant impacts to groundwater in surrounding areas in both active and post-mining phases. The prediction of water inflows into a surface mine excavation is one of the many components involved in mine design phase. Groundwater performance also reacts to mining activities from the operational, economic and safety implications perspective. Under NSW planning legislation, as part of the comprehensive risk assessment, a groundwater impact assessment has to be conducted for a coal project to predict and mitigate the impacts in consideration of the government requirements. In this paper, the groundwater assessment modelling of mine pits was discussed in predicting of groundwater inflows and reviewing analytical and numerical approaches. A methodology of groundwater impact assessment for an open cut mine in NSW with a three-dimensional groundwater flow model Modflow Surfact demonstrated its functions in simulating the project's impacts on the groundwater regime. The key findings with mitigations are discussed and recommended in the paper to reduce impacts on groundwater and fulfil regulation requirements in NSW.展开更多
In this research, the degradation of dibenzothiophene(DBT) was investigated by using Pseudomonas sp. LKY-5 isolated from oil contaminated soil. The response surface methodology(RSM) based on the Box-Behnken design(BBD...In this research, the degradation of dibenzothiophene(DBT) was investigated by using Pseudomonas sp. LKY-5 isolated from oil contaminated soil. The response surface methodology(RSM) based on the Box-Behnken design(BBD) was applied for evaluating the interactive effects of four independent variables including substrate concentration, temperature, pH and agitation rate on the DBT removal response. A total of 29 experiments for four factors at three levels were conducted in present study. A second-order regression model was then developed, and the analysis of variance(ANOVA) illustrated that the proposed quadratic model could be utilized to navigate the design space. The value of determination coefficient(R2=0.953 4) indicated a satisfactory agreement between the quadratic model and the experimental data. It was found that DBT removal was more significantly affected(P<0.000 1) by substrate concentration compared with other three parameters. An 100% degradation of DBT could be obtained by Pseudomonas sp. LKY-5 at a substrate concentration of 100 mg/L.展开更多
The method based on solvent parameters(mass,cycle of acidification, and autodeposition time), combined with response surface methodology(RSM) modeling and optimization, has been developed for maximizing ^(210)Po activ...The method based on solvent parameters(mass,cycle of acidification, and autodeposition time), combined with response surface methodology(RSM) modeling and optimization, has been developed for maximizing ^(210)Po activity in tea samples, as observed by an alpha spectrometer. RSM based on 3-factor and 5-level composite center design was used to obtain the optimal combination of solvent conditions. As solvent parameters for ^(210)Po activity, different masses(0.5, 0.75, 1, 1.5, and 2 g), different cycles of acidification(2, 3, 4, 5, and 6 times), and different autodeposition times(2, 3, 4, 5, and 6 h) were studied. The 3D response surface plot and the contour plot derived from the mathematical models were used to determine the optimal conditions. According to the obtained results, the experimental value of ^(210)Po activity was in good agreement(R^2=0.96) with the value predicted by the model. We found a favorable effect of mass on the ^(210)Po activity(p\0.05).展开更多
Uranium hexafluoride(UF6)leakage accidents represent one of the most serious classes of accidents in the gasification process in nuclear fuel manufacturing facilities.Common UF6 leakage accidents include various fault...Uranium hexafluoride(UF6)leakage accidents represent one of the most serious classes of accidents in the gasification process in nuclear fuel manufacturing facilities.Common UF6 leakage accidents include various fault conditions,such as pipeline and valve breakages or ruptures and pipeline blockages.By establishing goal-oriented(GO)operators that can represent multi-fault states,this study estimates the probabilities of various fault states corresponding to UF6 leakage accidents in the gasification process using the GO methodology and analyzes the system reliability.This article expands the scope of the GO methodology and provides technical support for reliability analysis using the GO methodology in multi-fault systems.展开更多
This study discussed the application of response surface methodology(RSM)and central composite rotatable design(CCRD)for modeling and optimization of the influence of some operating variables on the performance of a l...This study discussed the application of response surface methodology(RSM)and central composite rotatable design(CCRD)for modeling and optimization of the influence of some operating variables on the performance of a lab scale thickener for dewatering of tailing in the flotation circuit.Four thickener operating variables,namely feed flowrate,solid percent,flocculant dosage and feedwell height were changed during the tests based on CCRD.The ranges of values of the thickener variables used in the design were a feed flowrate of 9–21 L/min,solid percent of 8%–20%,flocculant dosage of 1.25–4.25 g/t and feedwell height of 16–26 cm.A total of 30 thickening tests were conducted using lab scale thickener on flotation tailing obtained from the Sarcheshmeh copper mine,Iran.The underflow solid percent and bed height were expressed as functions of four operating parameters of thickener.Predicted values were found to be in good agreement with experimental values(R2values of 0.992 and 0.997 for underflow solid percent and bed height,respectively).This study has shown that the RSM and CCRD could effciently be applied for the modeling of thickener for dewatering of flotation tailing.展开更多
The conversion of methane to liquid fuels is still in the development process. The modified HZSM-5 by loading with Tungsten （W） enhanced its heat resistant performance, and the high reaction temperature （800℃） di...The conversion of methane to liquid fuels is still in the development process. The modified HZSM-5 by loading with Tungsten （W） enhanced its heat resistant performance, and the high reaction temperature （800℃） did not lead to the loss of W component by sublimation. The loading of ZSM-5 with Tungsten and Copper （Cu） resulted in an increment in the methane conversion, CO2, and C5＋ selectivities. The high methane conversion and C5＋ selectivity, and low H2O selectivity are obtained by using W/3.0Cu/ZSM-5. The optimization of methane conversion over 3.0 W/3.0Cu/ZSM-5 under different temperature and oxygen concentration using response surface methodology （RSM） are studied. The optimum point for methane conversion is 19% when temperature is 753 ℃, and oxygen concentration is 12%. The highest C5＋ selectivity is 27% when temperature is 751 ℃. and oxwen concentration is 11%.展开更多
Coal is the world＇s most abundant energy source because of its abundance and relatively low cost. Due to the scarcity in the supply of high-grade coal, it is necessary to use low-.grade coal for fulfilling energy dem...Coal is the world＇s most abundant energy source because of its abundance and relatively low cost. Due to the scarcity in the supply of high-grade coal, it is necessary to use low-.grade coal for fulfilling energy demands of modern civilization. However, due to ItS high ash and moisture content, low-grade coal exerts the substantial impact on their consumption like pyrolysis, liquefaction, gasification and combus- tion process. The present research aimed to develop the efficient technique for the production of clean coal by optimizing the operating parameters with the help of response surface methodology. The effect of three independent variables such as hydrofluoric acid （HF） concentration （10-20% by vo!ume ）,. temper- ature （60-100 ~C）, and time （90-180 min）, for ash reduction from the low-grade coal was Investigated.. A quadratic model was proposed to correlate the independent variables for maximum ash reduction at the optimum process condition by using central composite design （CC.D）method. The study reveals that HF concentration was the most effective parameter for ash reduction in comparison with time and temper- ature. It may be due to the higher F-statistics value for HF concentration, which effects to large extent of ash reduction. The characterization of coal was evaluated by Fourier transform infrared spectroscopy （FTIR） analysis and Field-emission scanning electron microscopy with energy-dispersive X-ray （FESEM- EDX） analysis for confirmation of the ash reduction.展开更多
The aim of this research was to develop an optimum fermentation and composition model for a new fermented pumpkin-based beverage with high probiotic survival and-glucosidase inhibitory activity.Relationship between fe...The aim of this research was to develop an optimum fermentation and composition model for a new fermented pumpkin-based beverage with high probiotic survival and-glucosidase inhibitory activity.Relationship between fermentation temperature,inoculum and ingredient concentration with response variables(fermentation time at the fermentation endpoint pH 4.5,survival rate of Lactobacillus mali K8 in pumpkin-based beverage treated with simulated gastrointestinal tract enzyme fluids,-glucosidase inhibitory activity and sensory overall acceptability after 4 weeks of refrigerated storage)was investigated using response surface methodology.Optimal formulation was obtained at an approximation of 40%pumpkin puree concentration,8 Log CFU/mL inoculum and at 35℃.The product derived from this optimum formula reached the fermentation endpoint after 28.34±0.10 h and the quality change during 4 weeks storage was studied.The product achieved 88.56±0.67%of L.mali survival after treatment with simulated gastric and intestinal juices;demonstrated 95.89±0.30% α-glucosidase inhibitory activity,as well as scored 6.99±0.40 on sensory overall acceptability after 4 weeks of storage.These findings illustrated that the model is effective in improving probiotic survival and α-glucosidase inhibitory activity with excellent sensory acceptability,thus may offer a dietary means for the management of hyperglycaemia.展开更多
We produced wood–plastic composite board by using sawmill wastage of mahogany（Swietenia macrophylla） wood and low density polyethylene.We used multi-response optimization to optimize the process parameters of compo...We produced wood–plastic composite board by using sawmill wastage of mahogany（Swietenia macrophylla） wood and low density polyethylene.We used multi-response optimization to optimize the process parameters of composite board production including mixing ratio,fire retardant（%） and pressing time（min）.We investigated the effects of these three process parameters in the mechanical and physical properties of the composite board.Afterwards,Box–Behnken design was performed as response surface methodology with desirability functions to attain the optimal level of mixing ratio,fire retardant and pressing time（min）.The maximum modulus of elasticity（MOE） and modulus of rupture（MOR） were achieved at the optimal conditions of wood plastic mixing ratio of60：40,pressing time of 9 min and zero fire retardant percentage.The optimized MOR and MOE were 13.12 and1,781.0 N mm-2,respectively.展开更多
The present study highlighted the use of modified H-ZSM-5 （Meso-HZ-5） as heterogeneous catalyst for the synthesis of octyl levulinate biolubricant by catalytic esterification of biomass derived renewable levulinic a...The present study highlighted the use of modified H-ZSM-5 （Meso-HZ-5） as heterogeneous catalyst for the synthesis of octyl levulinate biolubricant by catalytic esterification of biomass derived renewable levulinic acid （LA） with n-octanol. The process variables such as catalyst loading （X1）, n-octanol to LA molar ratio （X2） and reaction temperature （X3） were optimized through response surface methodology （RSM）, using Box-Behnken model. Analysis of variance was performed to determine the adequacy and significance of the quadratic model. The yield of octyl levulinate was obtained to be 99% at optimum process parameters. The developed quadratic model was found to be adequate and statistically accurate with correlation value （R2） of 0.9971 to predict the yield of octyl levulinate biolubricant. The study was also extended on the validation of theoretical and experimental data, including catalyst reusability.展开更多
Air pollution is a major health problem in developing countries and has adverse effects on human health and the environment. Non-thermal plasma is an effective air pollution treatment technology. In this research, the...Air pollution is a major health problem in developing countries and has adverse effects on human health and the environment. Non-thermal plasma is an effective air pollution treatment technology. In this research, the performance of a dielectric barrier discharge(DBD) plasma reactor packed with glass and ceramic pellets was evaluated in the removal of SO_2 as a major air pollutant from air in ambient temperature. The response surface methodology was used to evaluate the effect of three key parameters(concentration of gas, gas flow rate, and voltage) as well as their simultaneous effects and interactions on the SO2 removal process. Reduced cubic models were derived to predict the SO_2 removal efficiency(RE) and energy yield(EY). Analysis of variance results showed that the packed-bed reactors(PBRs) studied were more energy efficient and had a high SO2 RE which was at least four times more than that of the non-packed reactor. Moreover, the results showed that the performance of ceramic pellets was better than that of glass pellets in PBRs. This may be due to the porous surface of ceramic pellets which allows the formation of microdischarges in the fine cavities of a porous surface when placed in a plasma discharge zone. The maximum SO_2 RE and EY were obtained at 94% and 0.81 g kWh^(-1),respectively under the optimal conditions of a concentration of gas of 750 ppm, a gas flow rate of 2lmin^(-1), and a voltage of 18 kV, which were achieved by the DBD plasma packed with ceramic pellets. Finally, the results of the model's predictions and the experiments showed good agreement.展开更多
By using a mixture of N2 and H2S as the simulated APG(associated petroleum gas), the desulfurization experiment was performed in a cross-flow rotating packed bed(RPB) based on the chelated iron oxidation-reduction met...By using a mixture of N2 and H2S as the simulated APG(associated petroleum gas), the desulfurization experiment was performed in a cross-flow rotating packed bed(RPB) based on the chelated iron oxidation-reduction method. In order to determine the operating conditions of the system, the effects of the concentration of Fe3+ ions(ranging from 0.1 to 0.2 mol/L), the liquid-gas volume ratio(ranging from 15 to 25 L/m3) and the high gravity factor(ranging from 36 to 126) on the removal of H2 S were studied by means of the Box-Behnken design(BBD) under response surface methodology(RSM). The overall results have demonstrated that the BBD with an experimental design can be used effectively in the optimization of the desulfurization process. The optimal conditions based on both individualized and combined responses(at a Fe3+ ion concentration of 0.16 mol/L, a liquid-gas volume ratio of 20.67 L/m3 and a high gravity factor of 87) were found. Under this optimum condition, the desulfurization efficiency could reach 98.81% when the H2 S concentration was 7 g/m3 in APG. In this work, the sulfur product was analyzed by X-ray diffraction(XRD), scanning electron microscopy(SEM) and the energy dispersive X-ray spectrometer(EDX). The results of analysis show that the sulfur is made of the high-purity orthorhombic crystals, which are advantageous to environmental conservation.展开更多
The main purpose of this paper is to provide a summarized general guideline to aid decision making of choosing the type of fatigue analysis approach,best suited for modelling and evaluating high-cycle fatigue damage i...The main purpose of this paper is to provide a summarized general guideline to aid decision making of choosing the type of fatigue analysis approach,best suited for modelling and evaluating high-cycle fatigue damage in welded structural joints.It describes how addition of stress concentration and stress direction information into fatigue assessment methodology affect simulated fatigue damage accumulation results and when it is beneficial or necessary to use a particular fatigue damage estimation approach.The focus is on stress-life curve based approaches,particularly when deciding between variants of nominal,hot-spot or multiaxial fatigue assessment approaches for evaluating fatigue damage within welded joint structures.Evaluation is illustrated through application of proposed methodology to choose and perform fatigue assessment for a non-conventional load-bearing tubular joint structure within a floating lemniscate crane upper arm,which has been observed of being prone to aggressive crack propagation within its welds.Damage within the structure is estimated using two non-optimal fatigue analysis approaches to verify applicability of proposed selection methodology.Results are then summarized through comparative assessment and findings are discussed based on what leads to result changes within each fatigue damage analysis approach.展开更多
基金The China Scholarship Council finances this research (Grant number CSC202010220001)。
文摘Wood,an essential natural resource in human civilization,remains widely used despite advances in technology and material substitution.The surge in greenhouse gas emissions and environmental concerns accentuates the need for optimizing wood utilization.Material flow analysis is a powerful tool for tracking material flows and stocks,aiding resource management and environmental decision-making.However,the full extent of its methodological dimensions,particularly within the context of the wood supply chain,remains relatively unexplored.In this study,we delve into the existing literature on wood flow analysis,discussing its primary objectives,materials involved,temporal and spatial scales,data sources,units,and conversion factors.Additionally,data uncertainty,data reconciliation and crucial assumptions in material flow analysis are highlighted in this paper.Key findings reveal the significance of wood cascading and substitution effects by replacing non-wood materials,where they can reduce greenhouse gas emissions more than the natural carbon sink of forests and wood products.The immediate impact of short-term wood cascading might not be as robust as the substitution effect,with energy substitution showcasing better results than material substitution.However,it's crucial to note that these conclusions could experience significant reversal from a long-term and global perspective.Strategies for improving wood efficiency involve maximizing material use,advancing construction technologies,extending product lifespans,promoting cascade use,and optimizing energy recovery processes.The study underscores the need for standardized approaches in wood flow analysis and emphasizes the potential of wood efficiency strategies in addressing environmental challenges.
基金Guangdong Provincial Key Laboratory of Traditional Chinese Medicine Informatization(2021B1212040007)Clinical Frontier Technology Program of the First Affiliated Hospital of Jinan University,China(JNU1AF-CFTP-2022-a01235)Science and Technology Projects in Guangzhou,China(202201020054,2023A03J1032).
文摘In the United States(US),the Surveillance,Epidemiology,and End Results(SEER)program is the only comprehensive source of population-based information that includes stage of cancer at the time of diagnosis and patient survival data.This program aims to provide a database about cancer incidence and survival for studies of surveillance and the development of analytical and methodological tools in the cancer field.Currently,the SEER program covers approximately half of the total cancer patients in the US.A growing number of clinical studies have applied the SEER database in various aspects.However,the intrinsic features of the SEER database,such as the huge data volume and complexity of data types,have hindered its application.In this review,we provided a systematic overview of the commonly used methodologies and study designs for retrospective epidemiological research in order to illustrate the application of the SEER database.Therefore,the goal of this review is to assist researchers in the selection of appropriate methods and study designs for enhancing the robustness and reliability of clinical studies by mining the SEER database.
基金supported by the National Natural Science Foundation of China(82174230)the Fundamental Research Funds for the Central Universities(2042022kf1213)。
文摘Integrated traditional Chinese medicine(TCM)and Western medicine(WM)is a new medical science grounded in the knowledge bases of both TCM and WM,which then forms a unique modern medical system in China.Integrated TCM and WM has a long history in China,and has made important achievements in the process of clinical diagnosis and treatment.However,the methodological defects in currently published clinical practice guidelines(CPGs)limit its development.The organic integration of TCM and WM is a deeper integration of TCM and WM.To realize the progression of"integration"to"organic integration",a targeted and standardized guideline development methodology is needed.Therefore,the purpose of this study is to establish a standardized development procedure for clinical practice guidelines for the organic integration of TCM and WM to promote the systematic integration of TCM and WM research results into clinical practice guidelines in order to achieve optimal results as the whole is greater than the sum of the parts.
文摘The uniform design and response surface methodology （RSM） are applied to the multi-objective optimization of a 2-D mixed compression scramjet inlet. The set of experimental design points on the design space is selected by the uniform design, and the inlet performance is analyzed by computational fluid dynamics （CFD）. Then complete quadratic polynomial response surface approximation models are constructed based on the performance analysis results and then used to replace theoriginal complex inlet performance model. The optimization is conducted using a multi-objective genetic algorithm NSGA-Ⅱ, and the Pareto optimal solution set is obtained. Results show that the uniform design and RSM can reduce the computational complexity of numerical simulation and improve the optimization efficiency.
文摘English teaching methodology is the guidance in the process of English teaching. Based on the analysis of multi-source data, quantitative research and visualized analysis, we are aimed to analyze the frontier of English teaching methodology and try to explore the advanced English teaching methodology, improve the English teaching and provide the scientific data and appropriate methods for the local English teaching.
文摘Sound transportation infrastructure is critical for economic development and sustainability. Pavement condition is a primary concern among agencies of the roadway infrastructure. Automation has become possible in recent years on collecting data and producing results for certain aspects of pavement performance, while challenges remain in several other categories, such as automated cracking survey. This paper reviews the technological advances on automated survey of pavements, and discusses the most recent breakthroughs by the team led by the author in using 3D laser imaging for capturing 1 mm surface images of pavements.
基金the University of Kashan, especially the Deputy of Research, for financial support (Grant: Pajoohaneh #1394/12)
文摘Oil from seeds of Diospyros lotus was extracted using a conventional method with two different solvents:hexane and petroleum ether. A central composite design with response surface methodology were used to optimize the process. A second-order polynomial equation was employed, and ANOVA was applied to evaluate the impact of various operating parameters including extraction temperature(x_1; 44.9–70.1 °C), extraction time(x_2;5.0–10.0 h) and solvent to solid ratio(x_3;11.6–28.4 mL g^(-1)), on oil yield. Experiments to validate the model showed decent conformity between predicted and actual values. Extraction conditions for optimal oil yield were 61 °C, 8.75 h extraction duration and 19.25 mL g^(-1) solvent to solid ratio. Under these conditions, the oil yield was predicted to be 5.1340%. Oil samples obtained were then analyzed using gas chromatography. The fatty acid composition revealed the major fatty acids to be oleic acid(C18:1) and linoleic acid(C18:2). The analysis of oil also demonstrated a decent ratio between omega-3 and omega-6 fatty acids. The structure of seeds was imaged using scanning electron microscopy. Oil quality was analyzed thermogravimetrically and by Fourier transform infrared spectroscopy. The assigned nutritional features of the D. lotus oil suggested that it can be used as an edible oil in pharmaceutical and food industry in the future.
文摘Large scale open cut coal mining operations have significant impacts to groundwater in surrounding areas in both active and post-mining phases. The prediction of water inflows into a surface mine excavation is one of the many components involved in mine design phase. Groundwater performance also reacts to mining activities from the operational, economic and safety implications perspective. Under NSW planning legislation, as part of the comprehensive risk assessment, a groundwater impact assessment has to be conducted for a coal project to predict and mitigate the impacts in consideration of the government requirements. In this paper, the groundwater assessment modelling of mine pits was discussed in predicting of groundwater inflows and reviewing analytical and numerical approaches. A methodology of groundwater impact assessment for an open cut mine in NSW with a three-dimensional groundwater flow model Modflow Surfact demonstrated its functions in simulating the project's impacts on the groundwater regime. The key findings with mitigations are discussed and recommended in the paper to reduce impacts on groundwater and fulfil regulation requirements in NSW.
基金support provided by the Fundamental Research Funds for the Central Universities (No. 12CX06043A) of Chinathe Key Laboratory of Marine Spill Oil Identification and Damage Assessment Technology,SOA(No. 201407)
文摘In this research, the degradation of dibenzothiophene(DBT) was investigated by using Pseudomonas sp. LKY-5 isolated from oil contaminated soil. The response surface methodology(RSM) based on the Box-Behnken design(BBD) was applied for evaluating the interactive effects of four independent variables including substrate concentration, temperature, pH and agitation rate on the DBT removal response. A total of 29 experiments for four factors at three levels were conducted in present study. A second-order regression model was then developed, and the analysis of variance(ANOVA) illustrated that the proposed quadratic model could be utilized to navigate the design space. The value of determination coefficient(R2=0.953 4) indicated a satisfactory agreement between the quadratic model and the experimental data. It was found that DBT removal was more significantly affected(P<0.000 1) by substrate concentration compared with other three parameters. An 100% degradation of DBT could be obtained by Pseudomonas sp. LKY-5 at a substrate concentration of 100 mg/L.
文摘The method based on solvent parameters(mass,cycle of acidification, and autodeposition time), combined with response surface methodology(RSM) modeling and optimization, has been developed for maximizing ^(210)Po activity in tea samples, as observed by an alpha spectrometer. RSM based on 3-factor and 5-level composite center design was used to obtain the optimal combination of solvent conditions. As solvent parameters for ^(210)Po activity, different masses(0.5, 0.75, 1, 1.5, and 2 g), different cycles of acidification(2, 3, 4, 5, and 6 times), and different autodeposition times(2, 3, 4, 5, and 6 h) were studied. The 3D response surface plot and the contour plot derived from the mathematical models were used to determine the optimal conditions. According to the obtained results, the experimental value of ^(210)Po activity was in good agreement(R^2=0.96) with the value predicted by the model. We found a favorable effect of mass on the ^(210)Po activity(p\0.05).
文摘Uranium hexafluoride(UF6)leakage accidents represent one of the most serious classes of accidents in the gasification process in nuclear fuel manufacturing facilities.Common UF6 leakage accidents include various fault conditions,such as pipeline and valve breakages or ruptures and pipeline blockages.By establishing goal-oriented(GO)operators that can represent multi-fault states,this study estimates the probabilities of various fault states corresponding to UF6 leakage accidents in the gasification process using the GO methodology and analyzes the system reliability.This article expands the scope of the GO methodology and provides technical support for reliability analysis using the GO methodology in multi-fault systems.
基金supported by the National Iranian Copper Industry Co.
文摘This study discussed the application of response surface methodology(RSM)and central composite rotatable design(CCRD)for modeling and optimization of the influence of some operating variables on the performance of a lab scale thickener for dewatering of tailing in the flotation circuit.Four thickener operating variables,namely feed flowrate,solid percent,flocculant dosage and feedwell height were changed during the tests based on CCRD.The ranges of values of the thickener variables used in the design were a feed flowrate of 9–21 L/min,solid percent of 8%–20%,flocculant dosage of 1.25–4.25 g/t and feedwell height of 16–26 cm.A total of 30 thickening tests were conducted using lab scale thickener on flotation tailing obtained from the Sarcheshmeh copper mine,Iran.The underflow solid percent and bed height were expressed as functions of four operating parameters of thickener.Predicted values were found to be in good agreement with experimental values(R2values of 0.992 and 0.997 for underflow solid percent and bed height,respectively).This study has shown that the RSM and CCRD could effciently be applied for the modeling of thickener for dewatering of flotation tailing.
文摘The conversion of methane to liquid fuels is still in the development process. The modified HZSM-5 by loading with Tungsten （W） enhanced its heat resistant performance, and the high reaction temperature （800℃） did not lead to the loss of W component by sublimation. The loading of ZSM-5 with Tungsten and Copper （Cu） resulted in an increment in the methane conversion, CO2, and C5＋ selectivities. The high methane conversion and C5＋ selectivity, and low H2O selectivity are obtained by using W/3.0Cu/ZSM-5. The optimization of methane conversion over 3.0 W/3.0Cu/ZSM-5 under different temperature and oxygen concentration using response surface methodology （RSM） are studied. The optimum point for methane conversion is 19% when temperature is 753 ℃, and oxygen concentration is 12%. The highest C5＋ selectivity is 27% when temperature is 751 ℃. and oxwen concentration is 11%.
文摘Coal is the world＇s most abundant energy source because of its abundance and relatively low cost. Due to the scarcity in the supply of high-grade coal, it is necessary to use low-.grade coal for fulfilling energy demands of modern civilization. However, due to ItS high ash and moisture content, low-grade coal exerts the substantial impact on their consumption like pyrolysis, liquefaction, gasification and combus- tion process. The present research aimed to develop the efficient technique for the production of clean coal by optimizing the operating parameters with the help of response surface methodology. The effect of three independent variables such as hydrofluoric acid （HF） concentration （10-20% by vo!ume ）,. temper- ature （60-100 ~C）, and time （90-180 min）, for ash reduction from the low-grade coal was Investigated.. A quadratic model was proposed to correlate the independent variables for maximum ash reduction at the optimum process condition by using central composite design （CC.D）method. The study reveals that HF concentration was the most effective parameter for ash reduction in comparison with time and temper- ature. It may be due to the higher F-statistics value for HF concentration, which effects to large extent of ash reduction. The characterization of coal was evaluated by Fourier transform infrared spectroscopy （FTIR） analysis and Field-emission scanning electron microscopy with energy-dispersive X-ray （FESEM- EDX） analysis for confirmation of the ash reduction.
基金The authors would like to appreciate and acknowledge ASEAN University Network(AUN)and Korea Association of the Southeast Asian Studies for providing financial support under ASEAN-ROK Academic Exchange Programme 2016/2017Universiti Sains Malaysia(USM)Vice Chancellor Award Scholarship and grant(RUI,1001/PTEKIND/811339).
文摘The aim of this research was to develop an optimum fermentation and composition model for a new fermented pumpkin-based beverage with high probiotic survival and-glucosidase inhibitory activity.Relationship between fermentation temperature,inoculum and ingredient concentration with response variables(fermentation time at the fermentation endpoint pH 4.5,survival rate of Lactobacillus mali K8 in pumpkin-based beverage treated with simulated gastrointestinal tract enzyme fluids,-glucosidase inhibitory activity and sensory overall acceptability after 4 weeks of refrigerated storage)was investigated using response surface methodology.Optimal formulation was obtained at an approximation of 40%pumpkin puree concentration,8 Log CFU/mL inoculum and at 35℃.The product derived from this optimum formula reached the fermentation endpoint after 28.34±0.10 h and the quality change during 4 weeks storage was studied.The product achieved 88.56±0.67%of L.mali survival after treatment with simulated gastric and intestinal juices;demonstrated 95.89±0.30% α-glucosidase inhibitory activity,as well as scored 6.99±0.40 on sensory overall acceptability after 4 weeks of storage.These findings illustrated that the model is effective in improving probiotic survival and α-glucosidase inhibitory activity with excellent sensory acceptability,thus may offer a dietary means for the management of hyperglycaemia.
文摘We produced wood–plastic composite board by using sawmill wastage of mahogany（Swietenia macrophylla） wood and low density polyethylene.We used multi-response optimization to optimize the process parameters of composite board production including mixing ratio,fire retardant（%） and pressing time（min）.We investigated the effects of these three process parameters in the mechanical and physical properties of the composite board.Afterwards,Box–Behnken design was performed as response surface methodology with desirability functions to attain the optimal level of mixing ratio,fire retardant and pressing time（min）.The maximum modulus of elasticity（MOE） and modulus of rupture（MOR） were achieved at the optimal conditions of wood plastic mixing ratio of60：40,pressing time of 9 min and zero fire retardant percentage.The optimized MOR and MOE were 13.12 and1,781.0 N mm-2,respectively.
基金supported by CSIR-XII FYP Networking Project BLB
文摘The present study highlighted the use of modified H-ZSM-5 （Meso-HZ-5） as heterogeneous catalyst for the synthesis of octyl levulinate biolubricant by catalytic esterification of biomass derived renewable levulinic acid （LA） with n-octanol. The process variables such as catalyst loading （X1）, n-octanol to LA molar ratio （X2） and reaction temperature （X3） were optimized through response surface methodology （RSM）, using Box-Behnken model. Analysis of variance was performed to determine the adequacy and significance of the quadratic model. The yield of octyl levulinate was obtained to be 99% at optimum process parameters. The developed quadratic model was found to be adequate and statistically accurate with correlation value （R2） of 0.9971 to predict the yield of octyl levulinate biolubricant. The study was also extended on the validation of theoretical and experimental data, including catalyst reusability.
基金financially supported by the Tarbiat Modares University of Tehran。
文摘Air pollution is a major health problem in developing countries and has adverse effects on human health and the environment. Non-thermal plasma is an effective air pollution treatment technology. In this research, the performance of a dielectric barrier discharge(DBD) plasma reactor packed with glass and ceramic pellets was evaluated in the removal of SO_2 as a major air pollutant from air in ambient temperature. The response surface methodology was used to evaluate the effect of three key parameters(concentration of gas, gas flow rate, and voltage) as well as their simultaneous effects and interactions on the SO2 removal process. Reduced cubic models were derived to predict the SO_2 removal efficiency(RE) and energy yield(EY). Analysis of variance results showed that the packed-bed reactors(PBRs) studied were more energy efficient and had a high SO2 RE which was at least four times more than that of the non-packed reactor. Moreover, the results showed that the performance of ceramic pellets was better than that of glass pellets in PBRs. This may be due to the porous surface of ceramic pellets which allows the formation of microdischarges in the fine cavities of a porous surface when placed in a plasma discharge zone. The maximum SO_2 RE and EY were obtained at 94% and 0.81 g kWh^(-1),respectively under the optimal conditions of a concentration of gas of 750 ppm, a gas flow rate of 2lmin^(-1), and a voltage of 18 kV, which were achieved by the DBD plasma packed with ceramic pellets. Finally, the results of the model's predictions and the experiments showed good agreement.
基金financially supported by the National Science Foundation of China (No. 21376229)the Science and Technology Development Plan of Shanxi Province (No. 20130321035-02)
文摘By using a mixture of N2 and H2S as the simulated APG(associated petroleum gas), the desulfurization experiment was performed in a cross-flow rotating packed bed(RPB) based on the chelated iron oxidation-reduction method. In order to determine the operating conditions of the system, the effects of the concentration of Fe3+ ions(ranging from 0.1 to 0.2 mol/L), the liquid-gas volume ratio(ranging from 15 to 25 L/m3) and the high gravity factor(ranging from 36 to 126) on the removal of H2 S were studied by means of the Box-Behnken design(BBD) under response surface methodology(RSM). The overall results have demonstrated that the BBD with an experimental design can be used effectively in the optimization of the desulfurization process. The optimal conditions based on both individualized and combined responses(at a Fe3+ ion concentration of 0.16 mol/L, a liquid-gas volume ratio of 20.67 L/m3 and a high gravity factor of 87) were found. Under this optimum condition, the desulfurization efficiency could reach 98.81% when the H2 S concentration was 7 g/m3 in APG. In this work, the sulfur product was analyzed by X-ray diffraction(XRD), scanning electron microscopy(SEM) and the energy dispersive X-ray spectrometer(EDX). The results of analysis show that the sulfur is made of the high-purity orthorhombic crystals, which are advantageous to environmental conservation.
文摘The main purpose of this paper is to provide a summarized general guideline to aid decision making of choosing the type of fatigue analysis approach,best suited for modelling and evaluating high-cycle fatigue damage in welded structural joints.It describes how addition of stress concentration and stress direction information into fatigue assessment methodology affect simulated fatigue damage accumulation results and when it is beneficial or necessary to use a particular fatigue damage estimation approach.The focus is on stress-life curve based approaches,particularly when deciding between variants of nominal,hot-spot or multiaxial fatigue assessment approaches for evaluating fatigue damage within welded joint structures.Evaluation is illustrated through application of proposed methodology to choose and perform fatigue assessment for a non-conventional load-bearing tubular joint structure within a floating lemniscate crane upper arm,which has been observed of being prone to aggressive crack propagation within its welds.Damage within the structure is estimated using two non-optimal fatigue analysis approaches to verify applicability of proposed selection methodology.Results are then summarized through comparative assessment and findings are discussed based on what leads to result changes within each fatigue damage analysis approach.
