As the world’s largest palm oil producer,Indonesia significantly benefits from its palm oil industry but also faces serious environmental challenges from palm oil mill effluent(POME)-a high-strength wastewater contai...As the world’s largest palm oil producer,Indonesia significantly benefits from its palm oil industry but also faces serious environmental challenges from palm oil mill effluent(POME)-a high-strength wastewater containing substantial organic matter,nutrients,suspended solids,and various chemical compounds.Sustainable and effective wastewater treatment strategies are urgently needed to address this issue.This review presents a comprehensive analysis of existing POME treatment technologies,including anaerobic digestion(AD),advanced oxidation processes(AOPs),membrane filtration,adsorption,phytoremediation,and microalgae-based systems.Each method is examined in terms of treatment efficiency,operational feasibility,and potential for imple-mentation under Indonesian conditions.While advanced processes,such as AOPs and membrane filtration,achieve high pollutant removal,they are often limited by operational costs.In contrast,biological approaches,such as AD and phytoremediation,offer both environmental benefits and economic value through the recovery of biogas,biofertilizers,and biomass.This review highlights the potential for integrating wastewater purification with resource recovery and valorization,supporting a shift toward more circular and sustainable management of POME.The insights provided are intended to guide future research,inform policy decisions,and facilitate the industrial adoption of optimized treatment systems.展开更多
In this paper,we consider the maximal positive definite solution of the nonlinear matrix equation.By using the idea of Algorithm 2.1 in ZHANG(2013),a new inversion-free method with a stepsize parameter is proposed to ...In this paper,we consider the maximal positive definite solution of the nonlinear matrix equation.By using the idea of Algorithm 2.1 in ZHANG(2013),a new inversion-free method with a stepsize parameter is proposed to obtain the maximal positive definite solution of nonlinear matrix equation X+A^(*)X|^(-α)A=Q with the case 0<α≤1.Based on this method,a new iterative algorithm is developed,and its convergence proof is given.Finally,two numerical examples are provided to show the effectiveness of the proposed method.展开更多
In this paper,a novel method for investigating the particle-crushing behavior of breeding particles in a fusion blanket is proposed.The fractal theory and Weibull distribution are combined to establish a theoretical m...In this paper,a novel method for investigating the particle-crushing behavior of breeding particles in a fusion blanket is proposed.The fractal theory and Weibull distribution are combined to establish a theoretical model,and its validity was verified using a simple impact test.A crushable discrete element method(DEM)framework is built based on the previously established theoretical model.The tensile strength,which considers the fractal theory,size effect,and Weibull variation,was assigned to each generated particle.The assigned strength is then used for crush detection by comparing it with its maximum tensile stress.Mass conservation is ensured by inserting a series of sub-particles whose total mass was equal to the quality loss.Based on the crushable DEM framework,a numerical simulation of the crushing behavior of a pebble bed with hollow cylindrical geometry under a uniaxial compression test was performed.The results of this investigation showed that the particle withstands the external load by contact and sliding at the beginning of the compression process,and the results confirmed that crushing can be considered an important method of resisting the increasing external load.A relatively regular particle arrangement aids in resisting the load and reduces the occurrence of particle crushing.However,a limit exists to the promotion of resistance.When the strain increases beyond this limit,the distribution of the crushing position tends to be isotropic over the entire pebble bed.The theoretical model and crushable DEM framework provide a new method for exploring the pebble bed in a fusion reactor,considering particle crushing.展开更多
Effective partitioning is crucial for enabling parallel restoration of power systems after blackouts.This paper proposes a novel partitioning method based on deep reinforcement learning.First,the partitioning decision...Effective partitioning is crucial for enabling parallel restoration of power systems after blackouts.This paper proposes a novel partitioning method based on deep reinforcement learning.First,the partitioning decision process is formulated as a Markov decision process(MDP)model to maximize the modularity.Corresponding key partitioning constraints on parallel restoration are considered.Second,based on the partitioning objective and constraints,the reward function of the partitioning MDP model is set by adopting a relative deviation normalization scheme to reduce mutual interference between the reward and penalty in the reward function.The soft bonus scaling mechanism is introduced to mitigate overestimation caused by abrupt jumps in the reward.Then,the deep Q network method is applied to solve the partitioning MDP model and generate partitioning schemes.Two experience replay buffers are employed to speed up the training process of the method.Finally,case studies on the IEEE 39-bus test system demonstrate that the proposed method can generate a high-modularity partitioning result that meets all key partitioning constraints,thereby improving the parallelism and reliability of the restoration process.Moreover,simulation results demonstrate that an appropriate discount factor is crucial for ensuring both the convergence speed and the stability of the partitioning training.展开更多
The application of nitrogen fertilizers in agricultural fields can lead to the release of nitrogen-containing gases(NCGs),such as NO_(x),NH_(3) and N_(2)O,which can significantly impact regional atmospheric environmen...The application of nitrogen fertilizers in agricultural fields can lead to the release of nitrogen-containing gases(NCGs),such as NO_(x),NH_(3) and N_(2)O,which can significantly impact regional atmospheric environment and con-tribute to global climate change.However,there remain considerable research gaps in the accurate measurement of NCGs emissions from agricultural fields,hindering the development of effective emission reduction strategies.We improved an open-top dynamic chambers(OTDCs)system and evaluated the performance by comparing the measured and given fluxes of the NCGs.The results showed that the measured fluxes of NO,N_(2)O and NH_(3)were 1%,2%and 7%lower than the given fluxes,respectively.For the determination of NH_(3) concentration,we employed a stripping coil-ion chromatograph(SC-IC)analytical technique,which demonstrated an absorption efficiency for atmospheric NH_(3) exceeding 96.1%across sampling durations of 6 to 60 min.In the summer maize season,we utilized the OTDCs system to measure the exchange fluxes of NO,NH_(3),and N_(2)O from the soil in the North China Plain.Substantial emissions of NO,NH_(3) and N_(2)O were recorded following fertilization,with peaks of 107,309,1239 ng N/(m^(2)·s),respectively.Notably,significant NCGs emissions were observed following sus-tained heavy rainfall one month after fertilization,particularly with NH_(3) peak being 4.5 times higher than that observed immediately after fertilization.Our results demonstrate that the OTDCs system accurately reflects the emission characteristics of soil NCGs and meets the requirements for long-term and continuous flux observation.展开更多
Convex feasibility problems are widely used in image reconstruction,sparse signal recovery,and other areas.This paper is devoted to considering a class of convex feasibility problem arising from sparse signal recovery...Convex feasibility problems are widely used in image reconstruction,sparse signal recovery,and other areas.This paper is devoted to considering a class of convex feasibility problem arising from sparse signal recovery.We rst derive the projection formulas for a vector onto the feasible sets.The centralized circumcentered-reection method is designed to solve the convex feasibility problem.Some numerical experiments demonstrate the feasibility and e ectiveness of the proposed algorithm,showing superior performance compared to conventional alternating projection methods.展开更多
Marine thin plates are susceptible to welding deformation owing to their low structural stiffness.Therefore,the efficient and accurate prediction of welding deformation is essential for improving welding quality.The t...Marine thin plates are susceptible to welding deformation owing to their low structural stiffness.Therefore,the efficient and accurate prediction of welding deformation is essential for improving welding quality.The traditional thermal elastic-plastic finite element method(TEP-FEM)can accurately predict welding deformation.However,its efficiency is low because of the complex nonlinear transient computation,making it difficult to meet the needs of rapid engineering evaluation.To address this challenge,this study proposes an efficient prediction method for welding deformation in marine thin plate butt welds.This method is based on the coupled temperature gradient-thermal strain method(TG-TSM)that integrates inherent strain theory with a shell element finite element model.The proposed method first extracts the distribution pattern and characteristic value of welding-induced inherent strain through TEP-FEM analysis.This strain is then converted into the equivalent thermal load applied to the shell element model for rapid computation.The proposed method-particularly,the gradual temperature gradient-thermal strain method(GTG-TSM)-achieved improved computational efficiency and consistent precision.Furthermore,the proposed method required much less computation time than the traditional TEP-FEM.Thus,this study lays the foundation for future prediction of welding deformation in more complex marine thin plates.展开更多
At present,there is currently a lack of unified standard methods for the determination of antimony content in groundwater in China.The precision and trueness of related detection technologies have not yet been systema...At present,there is currently a lack of unified standard methods for the determination of antimony content in groundwater in China.The precision and trueness of related detection technologies have not yet been systematically and quantitatively evaluated,which limits the effective implementation of environmental monitoring.In response to this key technical gap,this study aimed to establish a standardized method for determining antimony in groundwater using Hydride Generation–Atomic Fluorescence Spectrometry(HG-AFS).Ten laboratories participated in inter-laboratory collaborative tests,and the statistical analysis of the test data was carried out in strict accordance with the technical specifications of GB/T 6379.2—2004 and GB/T 6379.4—2006.The consistency and outliers of the data were tested by Mandel's h and k statistics,the Grubbs test and the Cochran test,and the outliers were removed to optimize the data,thereby significantly improving the reliability and accuracy.Based on the optimized data,parameters such as the repeatability limit(r),reproducibility limit(R),and method bias value(δ)were determined,and the trueness of the method was statistically evaluated.At the same time,precision-function relationships were established,and all results met the requirements.The results show that the lower the antimony content,the lower the repeatability limit(r)and reproducibility limit(R),indicating that the measurement error mainly originates from the detection limit of the method and instrument sensitivity.Therefore,improving the instrument sensitivity and reducing the detection limit are the keys to controlling the analytical error and improving precision.This study provides reliable data support and a solid technical foundation for the establishment and evaluation of standardized methods for the determination of antimony content in groundwater.展开更多
Palm oil industry is the most important agro-industry in Malaysia, but its by-product-palm oil mill effluent （POME）, posed a great threat to water environment. In the past decades, several treatment and disposal met...Palm oil industry is the most important agro-industry in Malaysia, but its by-product-palm oil mill effluent （POME）, posed a great threat to water environment. In the past decades, several treatment and disposal methods have been proposed and investigated to solve this problem. A two-stage pilot-scale plant was designed and constructed for POME treatment. Anaerobic digestion and aerobic biodegradation constituted the first biological stage, while ultrafiltration （UF） and reverse osmosis （RO） membrane units were combined as the second membrane separation stage. In the anaerobic expanded granular sludge bed （EGSB） reactor, about 43% organic matter in POME was converted into biogas, and COD reduction efficiency reached 93% and 22% in EGSB and the following aerobic reactor, respectively. With the treatment in the first biological stage, suspended solids and oil also decreased to a low degree. All these alleviated the membrane fouling and prolonged the membrane life. In the membrane process unit, almost all the suspended solids were captured by UF membranes, while RO membrane excluded most of the dissolved solids or inorganic salts from RO permeate. After the whole treatment processes, organic matter in POME expressed by BOD and COD was removed almost thoroughly. Suspended solids and color were not detectable in RO permeate any more, and mineral elements only existed in trace amount （except for K and Na）. The high-quality effluent was crystal clear and could be used as the boiler feed water.展开更多
Sugar palm(Arenga pinnata)starch is considered an important renewable,biodegradable,and eco-friendly polymer,which is derived from agricultural by-products and residues,with great potential for the development of bioc...Sugar palm(Arenga pinnata)starch is considered an important renewable,biodegradable,and eco-friendly polymer,which is derived from agricultural by-products and residues,with great potential for the development of biocomposite materials.This research was aimed at investigating the development of TPS biocomposites from A.pinnata palm starch using an extrusion process.Palm starch,glycerol,and stearic acid were extruded in a twin-screw extruder.Scanning electron microscopy(SEM)analysis of TPS showed that the starch granules were damaged and gelatinized in the extrusion process.The density of TPS was 1.3695 g/mL,lower than that of palm starch,and the addition of stearic acid resulted in increased TPS density.X-ray diffraction(XRD)results showed that palm starch had a C-type pattern crystalline structure.The tensile strength,elongation at break,and modulus of elasticity of TPS were 7.19 MPa,33.95%,and 0.56 GPa,respectively.The addition of stearic acid reduced the tensile strength,elongation at break and modulus of elasticity of TPS.The rheological properties,i.e.,melt flow rate(MFR)and viscosity of TPS,were 7.13 g/10 min and 2482.19 Pa.s,respectively.The presence of stearic acid in TPS resulted in increased MFR and decreased viscosity values.The peak gelatinization temperature of A.pinnata palm starch was 70°C,while Tg of TPS was 65°C.The addition of stearic acid reduced the Tg of TPS.The thermogravimetric analysis(TGA)analysis showed that the addition of glycerol and stearic acid decreased the thermal stability,but extended the temperature range of thermal degradation.TPS derived from A.pinnata palm starch by extrusion method has the potential to be applied in industrial practice as a promising raw material for manufacturing bio-based packaging as a sustainable and green alternative to petroleum-based plastics.展开更多
Milk fat contains a variety of nutritive and health-promoting compounds that guard against some disease. In the current system of global competition, when the quality of milk and milk products is not an option but rat...Milk fat contains a variety of nutritive and health-promoting compounds that guard against some disease. In the current system of global competition, when the quality of milk and milk products is not an option but rather a requirement, therefore, determining the purity of milk fat is critical. This study aims to validate analytical methods for detecting palm oil in a mixture of milk fat and palm oil. Methods of this study was involved detection of non-milk fat in fat blinders by determining the saponification value, iodine number, refractive index, butyro refractometer reading, Gas chromatography, Reverse Phase High-performance liquid chromatography, and Fourier transforms Infrared. The results of this study revealed that the saponification value, Iodine number, refractive index, and Butyro Reading could be used to detect the addition of palm oil by a level of 10% - 20% or more to the milk. The level of some fatty acids in the milk as determined by GC, such as myristic acid (C14:0), palmitic acid (C16:0), and stearic acid (C18:0), is correlated well with the level of adding palm oil to milk fat. The determination of cholesterol and β-sito-sterol content by RP-HPLC could be used for the detection of the addition of palm oil to milk fat. The spectrum behavior produced by FTIR spectroscopy in this adulterated sample is almost the same, so this technique could not be used to detect the palm oil in milk fat.展开更多
In date palm Phoenix dactylifera L. male （pollen bearing） and female （fruit bearing） inflorescences are on separate palms. To ensure good fertilization and better yield, artificial pollination is carried out in da...In date palm Phoenix dactylifera L. male （pollen bearing） and female （fruit bearing） inflorescences are on separate palms. To ensure good fertilization and better yield, artificial pollination is carried out in date plantations, where pollen harvested from male flowers are used for artificial pollination which is usually done manually. Often, the availability of male flowers becomes scarce due to the high demand to take up pollination during the short period of time when the female flowers are receptive. We assessed the comparative efficiency of using pollen to manually pollinate female date palm flowers in the field using sponge pieces charged with harvested pollen as compared to the traditional practice of the farmers using male inflorescences. Results revealed that fruit set （%）, fructification （%）, yield per bunch （kg） besides fruit weight, length and breadth were statistically similar in the two pollination methods evaluated. The sponge method of manual pollination can therefore serve as a viable alternative to the traditional method of pollination with the possibility of using stored pollen especially where male palms are scarce and pollen is difficult to obtain.展开更多
The main objective of this study was to investigate the presence of natural endophytic Beauveria bassiana within date palm tissues using molecular technique and measure their field efficacies in controlling Dubas bug,...The main objective of this study was to investigate the presence of natural endophytic Beauveria bassiana within date palm tissues using molecular technique and measure their field efficacies in controlling Dubas bug, Ornmatissus lybicus （Deberg）. Two entomopathogenic B. bassiana isolates （MARD 108 and 100） were isolated from date palm, Phoenix dactylifera L. leaves; in addition, one isolate （MARD 92） originally from soil was identified to have endophytic property. Concentration of 1 × 10^9 conidia/mL of each of three endophytic isolates was used in field experiments targeting Dubas bug nymphs via injection tree trunks. The results indicated that the high mortality rates reached 92%, 96% and 100% with infliction of the three endophytic isolates after 15 d from the treatment. The successful establishment of the fungal isolates in the date palm tissue was determined using B. bassiana species-specific primer for the first time via using conventional polymerase chain reaction （PCR） amplification technique before and after injection, and the positive gel band representation was the identification signs. The novel results depicted for the first time the presence of natural endophytic B. bassiana isolates within date palm tissues and their field efficacies in controlling Dubas bug, O. lybicus （Deberg） infestation.展开更多
Modal parameters can accurately characterize the structural dynamic properties and assess the physical state of the structure.Therefore,it is particularly significant to identify the structural modal parameters accordi...Modal parameters can accurately characterize the structural dynamic properties and assess the physical state of the structure.Therefore,it is particularly significant to identify the structural modal parameters according to the monitoring data information in the structural health monitoring(SHM)system,so as to provide a scientific basis for structural damage identification and dynamic model modification.In view of this,this paper reviews methods for identifying structural modal parameters under environmental excitation and briefly describes how to identify structural damages based on the derived modal parameters.The paper primarily introduces data-driven modal parameter recognition methods(e.g.,time-domain,frequency-domain,and time-frequency-domain methods,etc.),briefly describes damage identification methods based on the variations of modal parameters(e.g.,natural frequency,modal shapes,and curvature modal shapes,etc.)and modal validation methods(e.g.,Stability Diagram and Modal Assurance Criterion,etc.).The current status of the application of artificial intelligence(AI)methods in the direction of modal parameter recognition and damage identification is further discussed.Based on the pre-vious analysis,the main development trends of structural modal parameter recognition and damage identification methods are given to provide scientific references for the optimized design and functional upgrading of SHM systems.展开更多
To analyze the differences in the transport and distribution of different types of proppants and to address issues such as the short effective support of proppant and poor placement in hydraulically intersecting fract...To analyze the differences in the transport and distribution of different types of proppants and to address issues such as the short effective support of proppant and poor placement in hydraulically intersecting fractures,this study considered the combined impact of geological-engineering factors on conductivity.Using reservoir production parameters and the discrete elementmethod,multispherical proppants were constructed.Additionally,a 3D fracture model,based on the specified conditions of the L block,employed coupled(Computational Fluid Dynamics)CFD-DEM(Discrete ElementMethod)for joint simulations to quantitatively analyze the transport and placement patterns of multispherical proppants in intersecting fractures.Results indicate that turbulent kinetic energy is an intrinsic factor affecting proppant transport.Moreover,the efficiency of placement and migration distance of low-sphericity quartz sand constructed by the DEM in the main fracture are significantly reduced compared to spherical ceramic proppants,with a 27.7%decrease in the volume fraction of the fracture surface,subsequently affecting the placement concentration and damaging fracture conductivity.Compared to small-angle fractures,controlling artificial and natural fractures to expand at angles of 45°to 60°increases the effective support length by approximately 20.6%.During hydraulic fracturing of gas wells,ensuring the fracture support area and post-closure conductivity can be achieved by controlling the sphericity of proppants and adjusting the perforation direction to control the direction of artificial fractures.展开更多
The palm vein authentication technology is extremely safe, accurate and reliable as it uses the vascular patterns contained within the body to confirm personal identification. The pattern of veins in the palm is compl...The palm vein authentication technology is extremely safe, accurate and reliable as it uses the vascular patterns contained within the body to confirm personal identification. The pattern of veins in the palm is complex and unique to each individual. Its non-contact function gives it a healthful advantage over other biometric technologies. This paper presents an algebraic method for personal authentication and identification using internal contactless palm vein images. We use MATLAB image processing toolbox to enhance the palm vein images and employ coset decomposition concept to store and identify the encoded palm vein feature vectors. Experimental evidence shows the validation and influence of the proposed approach.展开更多
This study assessed the effect of processing method on the carotenoid profile of oil from three varieties of Nigerian oil palm fruits (Elaise guinensis). Specific varieties of the Elaise guinensis, which are the dura,...This study assessed the effect of processing method on the carotenoid profile of oil from three varieties of Nigerian oil palm fruits (Elaise guinensis). Specific varieties of the Elaise guinensis, which are the dura, pesifera and tenera were obtained from National Institute for Oil Palm Research (NIFOR) in Edo state, Nigeria. The samples were divided into two and processed using two different methods as commonly practiced in south-eastern Nigeria, the hot and cold processes. The oil extracted from each of the processes was then analyzed for oil characteristics using standard analytical methods while the carotenoid profile was analyzed using HPLC C-21 column. The results generated were subjected to the one-way analysis of variance (ANOVA). The results of carotenoid constituent identified include: lutein, neurosporene (trans), neurosporene (cis), α-Zeacarotene(cis), α-Zeacarotene(trans), phytoene, phytofluene, β-zeacarotene, 13 and 13’ cis α-carotene, 13 cis β-carotene, trans α-carotene, 9 cis α-carotene, trans β-carotene, αcarotene a(cis), α-carotene b(cis), α-carotene (trans), γ-carotene (trans), γ-carotene b(cis), lycopene (cis) and lycopene (trans). The results of physicochemical characteristics of the oil samples extracted range from 0.922 ± 0.004 - 0.916 ± 0.001 for specific gravity (SG), 8.10 ± 0.17 - 4.88 ± 0.04 mg KOH/g for acid value, 4.29% ± 0.02% - 2.44% ± 0.02% for free fatty acid value (FFA), 6.00 ± 0.21 to 204.67 ± 0.98 mgKOH/g for saponification value and 9.53 ± 0.23 - 5.25 ± 0.33 mEq/kg;for peroxide value while the carotenoids values were between 53.735 ± 0.10 and 123.389 ± 0.20 mg/100g. From the result, we can observe that the main constituent of the palm oil carotenoid is the β-carotene which makes up to about 80% of the total carotene. Statistical analysis revealed that no significant difference exists between the mean of each of the processing methods on the carotenoid profile of the oil sample analyzed.展开更多
There are many factors affecting the performance of a treatment system especially in the treatment of palm oil mill effluent （POME） as its contains high amounts of suspended solid, low pH, high salt content and high...There are many factors affecting the performance of a treatment system especially in the treatment of palm oil mill effluent （POME） as its contains high amounts of suspended solid, low pH, high salt content and high chemical oxygen demand （COD）. However, one factor at a time approach is complicated method in establishing relationship between multiple parameters. Response surface methodology （RSM） is a recommended approach as it is widely used to analyze and study the interactions between multiple parameters and provides optimum output as well as minimizing the defects which result in good treatment system. This paper overviews the recent and current research in the application of RSM in optimizing the treatment development of POME.展开更多
基金supporting the research project under the USK Leading Research Program-Doctoral Acceleration Scheme(PRRU-PD,Grant Number:444/UN11.2.1/PG.01.03/SPK/PTNBH/2024)coordinated by the Institute for Research and Community Services(LPPM-USK).
文摘As the world’s largest palm oil producer,Indonesia significantly benefits from its palm oil industry but also faces serious environmental challenges from palm oil mill effluent(POME)-a high-strength wastewater containing substantial organic matter,nutrients,suspended solids,and various chemical compounds.Sustainable and effective wastewater treatment strategies are urgently needed to address this issue.This review presents a comprehensive analysis of existing POME treatment technologies,including anaerobic digestion(AD),advanced oxidation processes(AOPs),membrane filtration,adsorption,phytoremediation,and microalgae-based systems.Each method is examined in terms of treatment efficiency,operational feasibility,and potential for imple-mentation under Indonesian conditions.While advanced processes,such as AOPs and membrane filtration,achieve high pollutant removal,they are often limited by operational costs.In contrast,biological approaches,such as AD and phytoremediation,offer both environmental benefits and economic value through the recovery of biogas,biofertilizers,and biomass.This review highlights the potential for integrating wastewater purification with resource recovery and valorization,supporting a shift toward more circular and sustainable management of POME.The insights provided are intended to guide future research,inform policy decisions,and facilitate the industrial adoption of optimized treatment systems.
基金Supported in part by Natural Science Foundation of Guangxi(2023GXNSFAA026246)in part by the Central Government's Guide to Local Science and Technology Development Fund(GuikeZY23055044)in part by the National Natural Science Foundation of China(62363003)。
文摘In this paper,we consider the maximal positive definite solution of the nonlinear matrix equation.By using the idea of Algorithm 2.1 in ZHANG(2013),a new inversion-free method with a stepsize parameter is proposed to obtain the maximal positive definite solution of nonlinear matrix equation X+A^(*)X|^(-α)A=Q with the case 0<α≤1.Based on this method,a new iterative algorithm is developed,and its convergence proof is given.Finally,two numerical examples are provided to show the effectiveness of the proposed method.
基金supported by Anhui Provincial Natural Science Foundation(2408085QA030)Natural Science Research Project of Anhui Educational Committee,China(2022AH050825)+3 种基金Medical Special Cultivation Project of Anhui University of Science and Technology(YZ2023H2C008)the Excellent Research and Innovation Team of Anhui Province,China(2022AH010052)the Scientific Research Foundation for High-level Talents of Anhui University of Science and Technology,China(2021yjrc51)Collaborative Innovation Program of Hefei Science Center,CAS,China(2019HSC-CIP006).
文摘In this paper,a novel method for investigating the particle-crushing behavior of breeding particles in a fusion blanket is proposed.The fractal theory and Weibull distribution are combined to establish a theoretical model,and its validity was verified using a simple impact test.A crushable discrete element method(DEM)framework is built based on the previously established theoretical model.The tensile strength,which considers the fractal theory,size effect,and Weibull variation,was assigned to each generated particle.The assigned strength is then used for crush detection by comparing it with its maximum tensile stress.Mass conservation is ensured by inserting a series of sub-particles whose total mass was equal to the quality loss.Based on the crushable DEM framework,a numerical simulation of the crushing behavior of a pebble bed with hollow cylindrical geometry under a uniaxial compression test was performed.The results of this investigation showed that the particle withstands the external load by contact and sliding at the beginning of the compression process,and the results confirmed that crushing can be considered an important method of resisting the increasing external load.A relatively regular particle arrangement aids in resisting the load and reduces the occurrence of particle crushing.However,a limit exists to the promotion of resistance.When the strain increases beyond this limit,the distribution of the crushing position tends to be isotropic over the entire pebble bed.The theoretical model and crushable DEM framework provide a new method for exploring the pebble bed in a fusion reactor,considering particle crushing.
基金funded by the Beijing Engineering Research Center of Electric Rail Transportation.
文摘Effective partitioning is crucial for enabling parallel restoration of power systems after blackouts.This paper proposes a novel partitioning method based on deep reinforcement learning.First,the partitioning decision process is formulated as a Markov decision process(MDP)model to maximize the modularity.Corresponding key partitioning constraints on parallel restoration are considered.Second,based on the partitioning objective and constraints,the reward function of the partitioning MDP model is set by adopting a relative deviation normalization scheme to reduce mutual interference between the reward and penalty in the reward function.The soft bonus scaling mechanism is introduced to mitigate overestimation caused by abrupt jumps in the reward.Then,the deep Q network method is applied to solve the partitioning MDP model and generate partitioning schemes.Two experience replay buffers are employed to speed up the training process of the method.Finally,case studies on the IEEE 39-bus test system demonstrate that the proposed method can generate a high-modularity partitioning result that meets all key partitioning constraints,thereby improving the parallelism and reliability of the restoration process.Moreover,simulation results demonstrate that an appropriate discount factor is crucial for ensuring both the convergence speed and the stability of the partitioning training.
基金supported by the National Key Research and Develop-ment Program(No.2022YFC3701103)the National Natural Science Foundation of China(Nos.42130714 and 41931287).
文摘The application of nitrogen fertilizers in agricultural fields can lead to the release of nitrogen-containing gases(NCGs),such as NO_(x),NH_(3) and N_(2)O,which can significantly impact regional atmospheric environment and con-tribute to global climate change.However,there remain considerable research gaps in the accurate measurement of NCGs emissions from agricultural fields,hindering the development of effective emission reduction strategies.We improved an open-top dynamic chambers(OTDCs)system and evaluated the performance by comparing the measured and given fluxes of the NCGs.The results showed that the measured fluxes of NO,N_(2)O and NH_(3)were 1%,2%and 7%lower than the given fluxes,respectively.For the determination of NH_(3) concentration,we employed a stripping coil-ion chromatograph(SC-IC)analytical technique,which demonstrated an absorption efficiency for atmospheric NH_(3) exceeding 96.1%across sampling durations of 6 to 60 min.In the summer maize season,we utilized the OTDCs system to measure the exchange fluxes of NO,NH_(3),and N_(2)O from the soil in the North China Plain.Substantial emissions of NO,NH_(3) and N_(2)O were recorded following fertilization,with peaks of 107,309,1239 ng N/(m^(2)·s),respectively.Notably,significant NCGs emissions were observed following sus-tained heavy rainfall one month after fertilization,particularly with NH_(3) peak being 4.5 times higher than that observed immediately after fertilization.Our results demonstrate that the OTDCs system accurately reflects the emission characteristics of soil NCGs and meets the requirements for long-term and continuous flux observation.
基金Supported by the Natural Science Foundation of Guangxi Province(Grant Nos.2023GXNSFAA026067,2024GXN SFAA010521)the National Natural Science Foundation of China(Nos.12361079,12201149,12261026).
文摘Convex feasibility problems are widely used in image reconstruction,sparse signal recovery,and other areas.This paper is devoted to considering a class of convex feasibility problem arising from sparse signal recovery.We rst derive the projection formulas for a vector onto the feasible sets.The centralized circumcentered-reection method is designed to solve the convex feasibility problem.Some numerical experiments demonstrate the feasibility and e ectiveness of the proposed algorithm,showing superior performance compared to conventional alternating projection methods.
基金Supported by the National Natural Science Foundation of China under Grant No.51975138the High-Tech Ship Scientific Research Project from the Ministry of Industry and Information Technology under Grant No.CJ05N20the National Defense Basic Research Project under Grant No.JCKY2023604C006.
文摘Marine thin plates are susceptible to welding deformation owing to their low structural stiffness.Therefore,the efficient and accurate prediction of welding deformation is essential for improving welding quality.The traditional thermal elastic-plastic finite element method(TEP-FEM)can accurately predict welding deformation.However,its efficiency is low because of the complex nonlinear transient computation,making it difficult to meet the needs of rapid engineering evaluation.To address this challenge,this study proposes an efficient prediction method for welding deformation in marine thin plate butt welds.This method is based on the coupled temperature gradient-thermal strain method(TG-TSM)that integrates inherent strain theory with a shell element finite element model.The proposed method first extracts the distribution pattern and characteristic value of welding-induced inherent strain through TEP-FEM analysis.This strain is then converted into the equivalent thermal load applied to the shell element model for rapid computation.The proposed method-particularly,the gradual temperature gradient-thermal strain method(GTG-TSM)-achieved improved computational efficiency and consistent precision.Furthermore,the proposed method required much less computation time than the traditional TEP-FEM.Thus,this study lays the foundation for future prediction of welding deformation in more complex marine thin plates.
基金supported by the National Natural Science Foundation of China(Project No.42307555).
文摘At present,there is currently a lack of unified standard methods for the determination of antimony content in groundwater in China.The precision and trueness of related detection technologies have not yet been systematically and quantitatively evaluated,which limits the effective implementation of environmental monitoring.In response to this key technical gap,this study aimed to establish a standardized method for determining antimony in groundwater using Hydride Generation–Atomic Fluorescence Spectrometry(HG-AFS).Ten laboratories participated in inter-laboratory collaborative tests,and the statistical analysis of the test data was carried out in strict accordance with the technical specifications of GB/T 6379.2—2004 and GB/T 6379.4—2006.The consistency and outliers of the data were tested by Mandel's h and k statistics,the Grubbs test and the Cochran test,and the outliers were removed to optimize the data,thereby significantly improving the reliability and accuracy.Based on the optimized data,parameters such as the repeatability limit(r),reproducibility limit(R),and method bias value(δ)were determined,and the trueness of the method was statistically evaluated.At the same time,precision-function relationships were established,and all results met the requirements.The results show that the lower the antimony content,the lower the repeatability limit(r)and reproducibility limit(R),indicating that the measurement error mainly originates from the detection limit of the method and instrument sensitivity.Therefore,improving the instrument sensitivity and reducing the detection limit are the keys to controlling the analytical error and improving precision.This study provides reliable data support and a solid technical foundation for the establishment and evaluation of standardized methods for the determination of antimony content in groundwater.
文摘Palm oil industry is the most important agro-industry in Malaysia, but its by-product-palm oil mill effluent （POME）, posed a great threat to water environment. In the past decades, several treatment and disposal methods have been proposed and investigated to solve this problem. A two-stage pilot-scale plant was designed and constructed for POME treatment. Anaerobic digestion and aerobic biodegradation constituted the first biological stage, while ultrafiltration （UF） and reverse osmosis （RO） membrane units were combined as the second membrane separation stage. In the anaerobic expanded granular sludge bed （EGSB） reactor, about 43% organic matter in POME was converted into biogas, and COD reduction efficiency reached 93% and 22% in EGSB and the following aerobic reactor, respectively. With the treatment in the first biological stage, suspended solids and oil also decreased to a low degree. All these alleviated the membrane fouling and prolonged the membrane life. In the membrane process unit, almost all the suspended solids were captured by UF membranes, while RO membrane excluded most of the dissolved solids or inorganic salts from RO permeate. After the whole treatment processes, organic matter in POME expressed by BOD and COD was removed almost thoroughly. Suspended solids and color were not detectable in RO permeate any more, and mineral elements only existed in trace amount （except for K and Na）. The high-quality effluent was crystal clear and could be used as the boiler feed water.
基金from The Hitachi Global Foundation Asia Innovation Award 2020.Also,the authors thank the facilities,scientific and technical support from Advanced Characterization Laboratories Serpong and Cibinong,National Research and Innovation Institute through E-Layanan Sains,Badan Riset dan Inovasi Nasional(BRIN).
文摘Sugar palm(Arenga pinnata)starch is considered an important renewable,biodegradable,and eco-friendly polymer,which is derived from agricultural by-products and residues,with great potential for the development of biocomposite materials.This research was aimed at investigating the development of TPS biocomposites from A.pinnata palm starch using an extrusion process.Palm starch,glycerol,and stearic acid were extruded in a twin-screw extruder.Scanning electron microscopy(SEM)analysis of TPS showed that the starch granules were damaged and gelatinized in the extrusion process.The density of TPS was 1.3695 g/mL,lower than that of palm starch,and the addition of stearic acid resulted in increased TPS density.X-ray diffraction(XRD)results showed that palm starch had a C-type pattern crystalline structure.The tensile strength,elongation at break,and modulus of elasticity of TPS were 7.19 MPa,33.95%,and 0.56 GPa,respectively.The addition of stearic acid reduced the tensile strength,elongation at break and modulus of elasticity of TPS.The rheological properties,i.e.,melt flow rate(MFR)and viscosity of TPS,were 7.13 g/10 min and 2482.19 Pa.s,respectively.The presence of stearic acid in TPS resulted in increased MFR and decreased viscosity values.The peak gelatinization temperature of A.pinnata palm starch was 70°C,while Tg of TPS was 65°C.The addition of stearic acid reduced the Tg of TPS.The thermogravimetric analysis(TGA)analysis showed that the addition of glycerol and stearic acid decreased the thermal stability,but extended the temperature range of thermal degradation.TPS derived from A.pinnata palm starch by extrusion method has the potential to be applied in industrial practice as a promising raw material for manufacturing bio-based packaging as a sustainable and green alternative to petroleum-based plastics.
文摘Milk fat contains a variety of nutritive and health-promoting compounds that guard against some disease. In the current system of global competition, when the quality of milk and milk products is not an option but rather a requirement, therefore, determining the purity of milk fat is critical. This study aims to validate analytical methods for detecting palm oil in a mixture of milk fat and palm oil. Methods of this study was involved detection of non-milk fat in fat blinders by determining the saponification value, iodine number, refractive index, butyro refractometer reading, Gas chromatography, Reverse Phase High-performance liquid chromatography, and Fourier transforms Infrared. The results of this study revealed that the saponification value, Iodine number, refractive index, and Butyro Reading could be used to detect the addition of palm oil by a level of 10% - 20% or more to the milk. The level of some fatty acids in the milk as determined by GC, such as myristic acid (C14:0), palmitic acid (C16:0), and stearic acid (C18:0), is correlated well with the level of adding palm oil to milk fat. The determination of cholesterol and β-sito-sterol content by RP-HPLC could be used for the detection of the addition of palm oil to milk fat. The spectrum behavior produced by FTIR spectroscopy in this adulterated sample is almost the same, so this technique could not be used to detect the palm oil in milk fat.
文摘In date palm Phoenix dactylifera L. male （pollen bearing） and female （fruit bearing） inflorescences are on separate palms. To ensure good fertilization and better yield, artificial pollination is carried out in date plantations, where pollen harvested from male flowers are used for artificial pollination which is usually done manually. Often, the availability of male flowers becomes scarce due to the high demand to take up pollination during the short period of time when the female flowers are receptive. We assessed the comparative efficiency of using pollen to manually pollinate female date palm flowers in the field using sponge pieces charged with harvested pollen as compared to the traditional practice of the farmers using male inflorescences. Results revealed that fruit set （%）, fructification （%）, yield per bunch （kg） besides fruit weight, length and breadth were statistically similar in the two pollination methods evaluated. The sponge method of manual pollination can therefore serve as a viable alternative to the traditional method of pollination with the possibility of using stored pollen especially where male palms are scarce and pollen is difficult to obtain.
文摘The main objective of this study was to investigate the presence of natural endophytic Beauveria bassiana within date palm tissues using molecular technique and measure their field efficacies in controlling Dubas bug, Ornmatissus lybicus （Deberg）. Two entomopathogenic B. bassiana isolates （MARD 108 and 100） were isolated from date palm, Phoenix dactylifera L. leaves; in addition, one isolate （MARD 92） originally from soil was identified to have endophytic property. Concentration of 1 × 10^9 conidia/mL of each of three endophytic isolates was used in field experiments targeting Dubas bug nymphs via injection tree trunks. The results indicated that the high mortality rates reached 92%, 96% and 100% with infliction of the three endophytic isolates after 15 d from the treatment. The successful establishment of the fungal isolates in the date palm tissue was determined using B. bassiana species-specific primer for the first time via using conventional polymerase chain reaction （PCR） amplification technique before and after injection, and the positive gel band representation was the identification signs. The novel results depicted for the first time the presence of natural endophytic B. bassiana isolates within date palm tissues and their field efficacies in controlling Dubas bug, O. lybicus （Deberg） infestation.
基金supported by the Innovation Foundation of Provincial Education Department of Gansu(2024B-005)the Gansu Province National Science Foundation(22YF7GA182)the Fundamental Research Funds for the Central Universities(No.lzujbky2022-kb01)。
文摘Modal parameters can accurately characterize the structural dynamic properties and assess the physical state of the structure.Therefore,it is particularly significant to identify the structural modal parameters according to the monitoring data information in the structural health monitoring(SHM)system,so as to provide a scientific basis for structural damage identification and dynamic model modification.In view of this,this paper reviews methods for identifying structural modal parameters under environmental excitation and briefly describes how to identify structural damages based on the derived modal parameters.The paper primarily introduces data-driven modal parameter recognition methods(e.g.,time-domain,frequency-domain,and time-frequency-domain methods,etc.),briefly describes damage identification methods based on the variations of modal parameters(e.g.,natural frequency,modal shapes,and curvature modal shapes,etc.)and modal validation methods(e.g.,Stability Diagram and Modal Assurance Criterion,etc.).The current status of the application of artificial intelligence(AI)methods in the direction of modal parameter recognition and damage identification is further discussed.Based on the pre-vious analysis,the main development trends of structural modal parameter recognition and damage identification methods are given to provide scientific references for the optimized design and functional upgrading of SHM systems.
基金funded by the project of the Major Scientific and Technological Projects of CNOOC in the 14th Five-Year Plan(No.KJGG2022-0701)the CNOOC Research Institute(No.2020PFS-03).
文摘To analyze the differences in the transport and distribution of different types of proppants and to address issues such as the short effective support of proppant and poor placement in hydraulically intersecting fractures,this study considered the combined impact of geological-engineering factors on conductivity.Using reservoir production parameters and the discrete elementmethod,multispherical proppants were constructed.Additionally,a 3D fracture model,based on the specified conditions of the L block,employed coupled(Computational Fluid Dynamics)CFD-DEM(Discrete ElementMethod)for joint simulations to quantitatively analyze the transport and placement patterns of multispherical proppants in intersecting fractures.Results indicate that turbulent kinetic energy is an intrinsic factor affecting proppant transport.Moreover,the efficiency of placement and migration distance of low-sphericity quartz sand constructed by the DEM in the main fracture are significantly reduced compared to spherical ceramic proppants,with a 27.7%decrease in the volume fraction of the fracture surface,subsequently affecting the placement concentration and damaging fracture conductivity.Compared to small-angle fractures,controlling artificial and natural fractures to expand at angles of 45°to 60°increases the effective support length by approximately 20.6%.During hydraulic fracturing of gas wells,ensuring the fracture support area and post-closure conductivity can be achieved by controlling the sphericity of proppants and adjusting the perforation direction to control the direction of artificial fractures.
文摘The palm vein authentication technology is extremely safe, accurate and reliable as it uses the vascular patterns contained within the body to confirm personal identification. The pattern of veins in the palm is complex and unique to each individual. Its non-contact function gives it a healthful advantage over other biometric technologies. This paper presents an algebraic method for personal authentication and identification using internal contactless palm vein images. We use MATLAB image processing toolbox to enhance the palm vein images and employ coset decomposition concept to store and identify the encoded palm vein feature vectors. Experimental evidence shows the validation and influence of the proposed approach.
文摘This study assessed the effect of processing method on the carotenoid profile of oil from three varieties of Nigerian oil palm fruits (Elaise guinensis). Specific varieties of the Elaise guinensis, which are the dura, pesifera and tenera were obtained from National Institute for Oil Palm Research (NIFOR) in Edo state, Nigeria. The samples were divided into two and processed using two different methods as commonly practiced in south-eastern Nigeria, the hot and cold processes. The oil extracted from each of the processes was then analyzed for oil characteristics using standard analytical methods while the carotenoid profile was analyzed using HPLC C-21 column. The results generated were subjected to the one-way analysis of variance (ANOVA). The results of carotenoid constituent identified include: lutein, neurosporene (trans), neurosporene (cis), α-Zeacarotene(cis), α-Zeacarotene(trans), phytoene, phytofluene, β-zeacarotene, 13 and 13’ cis α-carotene, 13 cis β-carotene, trans α-carotene, 9 cis α-carotene, trans β-carotene, αcarotene a(cis), α-carotene b(cis), α-carotene (trans), γ-carotene (trans), γ-carotene b(cis), lycopene (cis) and lycopene (trans). The results of physicochemical characteristics of the oil samples extracted range from 0.922 ± 0.004 - 0.916 ± 0.001 for specific gravity (SG), 8.10 ± 0.17 - 4.88 ± 0.04 mg KOH/g for acid value, 4.29% ± 0.02% - 2.44% ± 0.02% for free fatty acid value (FFA), 6.00 ± 0.21 to 204.67 ± 0.98 mgKOH/g for saponification value and 9.53 ± 0.23 - 5.25 ± 0.33 mEq/kg;for peroxide value while the carotenoids values were between 53.735 ± 0.10 and 123.389 ± 0.20 mg/100g. From the result, we can observe that the main constituent of the palm oil carotenoid is the β-carotene which makes up to about 80% of the total carotene. Statistical analysis revealed that no significant difference exists between the mean of each of the processing methods on the carotenoid profile of the oil sample analyzed.
文摘There are many factors affecting the performance of a treatment system especially in the treatment of palm oil mill effluent （POME） as its contains high amounts of suspended solid, low pH, high salt content and high chemical oxygen demand （COD）. However, one factor at a time approach is complicated method in establishing relationship between multiple parameters. Response surface methodology （RSM） is a recommended approach as it is widely used to analyze and study the interactions between multiple parameters and provides optimum output as well as minimizing the defects which result in good treatment system. This paper overviews the recent and current research in the application of RSM in optimizing the treatment development of POME.
