Dissipation Pattern Research Articles

Hydrolytic Behavior of Novel Pesticide Broflanilide and Its Dissipative Properties in Different Types of Soils.

All pesticides are toxic by nature and pose short- or long-term safety risks to human or the environment, especially when they were used extensively and absence of safety measures. As a new insecticidal active compound with a novel mechanism of action, there is a serious inadequate of information on the hydrolytic behavior of broflanilide in the aqueous environment, as well as its degradation pattern in agricultural soils. In particular, the effects of temperature and pH of the aqueous environment on its hydrolytic behaviors and the dissipation pattern in different types of agricultural soils were still in a dark box. And the further understanding and insights into this insecticidal active ingredient were being deeply conditioned by these doubts. The hydrolysis behavior of broflanilide and the dissipation pattern in soil were systematically investigated by constructing hydrolysis systems with different temperatures and pH values, and conducting spiking experiments in different types of agricultural soil in the laboratory. The obtained results showed that the longest hydrolysis half-life of 10mg/L broflanilide at 25°C was 43.32h (in pH 4.0 buffer), while it was only 12.84h in pH 9.0 buffer. In pH 7.0 buffer, the hydrolysis rate of broflanilide exhibited a significant temperature dependence, as shown by the fact that for every 10°C increase in the system temperature, the corresponding hydrolysis rate will increase about 1.5 times. The dissipation experiments in soils showed that broflanilide was most rapidly dissipated in fluvo-aquic soil (half-life of 1.94days), followed by lime concretion black soil (half-life of 2.53days) and cinnamon soil (half-life of 3.11days), and slower in paddy soil (half-life of 4.03days). It was indicated that broflanilide was a readily degradable pesticide in both aqueous environment and agricultural soil, and it was significantly affected by the temperature and pH of the system.

Determination of residues of two organophosphates and their dissipation pattern by QuEChERS method

Determination of residues of two organophosphates and their dissipation pattern by QuEChERS method

Experimental and theoretical study on an innovative energy absorption structure comprised of composite materials with necked‐down section subject to axial compressive load

AbstractEnergy absorption structure with necked‐down section possesses great application prospect owing to superior energy absorption ability. However, rare studies on this innovation structures were conducted. Therefore, an innovative energy absorption structure which consists of a composite tube and a trigger structure was proposed. In the trigger structure, necked‐down section is included. To investigate effect of thickness of composite tube, diameter variation and angle variation of the necked‐down section on energy absorption performance, 56 kinds of parameter configuration were generated, each of which was repeatedly tested three times. From the results of comprehensive experimental study, it can be concluded there were five different energy dissipation patterns for the proposed energy absorption structure. Different energy dissipation patterns were related to different failure modes. Brittle failure was featured by energy dissipation pattern I and II at stable energy dissipation stage while energy dissipation pattern III and IV played important role in progressive failure. Compared to the brittle failure mode, the SEA and force fluctuation ratio of the progressive failure mode increased and decreased by 48% and 52%, respectively. Energy absorption ability can be described by average compressive load capacity at stable energy dissipation stage, for which the theoretical model was developed. Effectiveness of proposed theoretical model was validated by comparing predicted average compressive load capacity with that obtained from experiment.

Dissipation kinetics and dietary risk assessment of pesticides in/on citrus (mandarin)

AbstractA supervised field trial was conducted to evaluate the dissipation pattern and dietary risk assessment of the pesticides, Solomon (recommended dose, X (63+147 g a.i./ha) and double the recommended dose, 2X (126+294 g a.i./ha)); spirotetramat (X dose: 90 g a.i./ha and 2X dose: 180 g a.i./ha) and indaziflam (X dose: 62.5 g a.i./ha and 2X dose: 125 g a.i./ha) in citrus (mandarin) fruits and cropped soil. Solomon and spirotetramet were applied as foliar spray at the fruit development stage and indaziflam was applied directly on to the weeds. Fruit and soil samples thus collected were extracted using a quick, easy, cheap, effective, rugged, and safe analytical method for residue estimation, which was carried out using Gas Chromatography‐Electron Capture Detector for betacyfluthrin and High‐Performance Liquid Chromatography for all other analytes. Residues of betacyfluthrin reached below the determination level (0.05 mg/kg) after the 3rd and 5th day of treatment at X and 2X dosage while imidacloprid and spirotetramat residues reached below the determination level on the 5th and 7th day, respectively. Residues of indaziflam and its metabolites were not detected in any citrus and soil matrices. Dietary risk assessment calculated as hazard quotient and theoretical maximum dietary intake revealed the safety of the pesticides for human consumption after application of these pesticides on citrus.

Uptake of Fungicide Fluopyram from Soil by Scallions during Greenhouse Cultivation.

Unintentional pesticide contamination in rotational crops, often caused by soil contamination from pesticide use in the preceding crops, is a major concern in a positive list system. The residue and dissipation pattern of fluopyram in soil and scallions were investigated to evaluate the uptake of fluopyram from the soil by scallions. In addition, the management concentration in soil (MCsoil) was calculated based on bioconcentration factors (BCFs) and the maximum residue limit (0.2 mg/kg) in leaf-and-stem vegetables. In a field experiment, plots in two different trials, A and B, were treated with 0.06 g fluopyram/m2 and maintained for 30 days according to OECD guidelines. Scallion seedlings were cultivated for 48 days. Soil samples were taken at three different time points: DAP (Days after planting) 0, 34, and 48. Scallion samples were collected at five different time points: DAP 20, 27, 34, 41, and 48. The initial amounts of fluopyram in soil at DAP 0 were 0.94 ± 0.03 and 0.96 ± 0.04 mg/kg in trials A and B, respectively. The half-life of fluopyram in the soil was 87-231 days. Fluopyram uptake by the roots increased over time, but fluopyram residue in the scallions decreased due to the dilution effect caused by an increase in plant weight. The residues in the scallions at DAP 48 were 0.22 ± 0.01 and 0.15 ± 0.01 mg/kg in trials A and B, respectively. The BCFs of scallions for fluopyram were 0.21-0.24 (trial A) and 0.14-0.18 (trial B). The MCsoil was proposed as 0.8 mg/kg, and may be utilized as a safe management guideline for precautionary practices to cultivate safe rotational crops.

Determination of chlorantraniliprole 18.5% SC in the paddy ecosystem and its risk assessment

Chlorantraniliprole belongsto theanthranilic diamide group is widely used against broad range of lepidopteron pests in a variety of vegetable and rice pests includingyellow rice stem borer and leaf folder. Supervised field trials were conducted duringRabi (2018–2019) and Kharif (2019) to evaluate the dissipation pattern and risk assessment of chlorantraniliprole 18.5% SC in paddy ecosystem following foliar application at 30 and 60 g a.i. ha-1 in two different cropping seasons.Modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) technique was used for the extraction of CAP residues with acetonitrile and determined by LC–MS/MS (ESI +).The limit of quantification (LOQ) was 0.01 µg g−1 for paddy leaf, straw, husk, and brown rice, respectively and 0.005 µg g−1 for soil. The average recoveries obtained were 84.30–88.92% from paddy leaf, 94.25–97.81% from straw, 90.21–93.38% from husk, 93.57–96.40% from brown rice and 89.93–91.14% from soil. The residues in paddy leaf dissipated within 35–40 days with a half-life of 4.33–5.07 days in Rabi and 3.92–4.86 days in Kharif at 30 and 60 g a.i. ha−1, respectively. The residues in soil dissipated within 15–21 days with a half-life of 14.44–15.75 days in Rabi and 13.33–14.44 days in Kharif at respective doses. At harvest chlorantraniliprole residues were not detected in straw, husk, and brown rice. The dietary risk of paddy leaf (green fodder) for cattle was found safe for consumption as the hazard index is less than one. Soil ecological risk assessment was found to be less than one (RQ < 0.1) for earthworms (Eisenia foetida) and arthropods (Aphidiusrhopalosiphi). The presentmethod could be useful inthe analysis ofchlorantraniliproleresidues in different cereals and vegetable crop ecosystems and application at recommended dose is safe for the final produce at harvest.

Dissipation pattern and safety assessment of fenazaquin and metaflumizone in butterbur (Petasites japonicus)

This study was conducted to investigate the residual behavior and safety assessment of fenazaquin and metaflumizone in butterbur. The samples were periodically harvested, extracted using QuEChERS method, and determined by LC-MS/MS. The linearity of matrix-matched calibration curve was ≥0.99 for both compounds. The average recoveries of fenazaquin and metaflumizone at two fortification levels (0.01 and 0.1 mg kg−1) ranged from 86.6 to 97.2%. The relative standard deviation was <10%. After 7 days, the fenazaquin and metaflumizone initial residues in butterbur were dissipated to 79 and 78%, with the respective half-lives, 3.08 and 3.15 days. The proposed preharvest intervals (PHIs) for fenazaquin is recommended as twice treatment 14 days before harvest and metaflumizone twice treatment 7 days before harvest of butterbur. Risk assessment showed that the acceptable daily intake of fenazaquin and metaflumizone in butterbur was 0.004 and 0.029%, respectively. The respective theoretical maximum daily intakes of fenazaquin and metaflumizone were 58.74 and 15.15%, indicating negligible risk.

Unusual Martian Foreshock Waves Triggered by a Solar Wind Stream Interaction Region

Planetary bow shocks noncollisionally dissipate the incident bulk flow energy of solar wind into some other forms. To what extent and how solar wind disturbances affect the energy dissipation processes at the bow shocks on different planets remain unclear. With the Chinese Tianwen-1 and American Mars Atmosphere and Volatile EvolutioN missions, we present the first observation of significant modifications by a solar wind stream interaction region to the Martian foreshock waves, which are an important energy dissipation product of the bow shock. After the stream interface hitting Mars, an unusual band of foreshock waves emerged, with a central frequency of ∼0.4 Hz and frequency width of ∼0.2 Hz. These waves exhibited highly distorted waveforms, with peak-to-peak amplitudes of 10–25 nT in contrast to a background magnetic field of 6–9 nT. They were approximately elliptically polarized with respect to the wavevector and propagated highly obliquely to the background magnetic field. These waves reported here differed greatly from the commonly known Martian foreshock “30 s waves” and “1 Hz waves,” but resembled, to some extent, the less frequently occurring terrestrial foreshock “3 s waves.” Our present findings may imply an unexpected energy dissipation pattern of the Martian bow shock to the disturbed solar wind, which needs further observational, theoretical, and numerical investigations.

Dissipation kinetics, effect of household processing, and dietary risk assessment of the insecticide chlorantraniliprole residue in bitter gourd and soil

A single quadrupole liquid chromatography-mass spectrometry (LC-MS) method was validated to determine the insecticide chlorantraniliprole residues in bitter gourd fruit, juice, and soil, according to the SANTE guidelines. A linear curve was obtained (R2 &gt; 0.99) with LOD and LOQ at 0.003 mg kg-1 and 0.01 mg kg-1. The accuracy (87–102%) and precision (RSD &lt;5%) of the method was found to be satisfactory. The dissipation pattern of chlorantraniliprole 18.5% SC was studied by spraying twice at ten days intervals, at the recommended dose (X) (25 g a.i. ha-1), and double the recommended dose (2X) (50 g a.i. ha-1). The initial deposit on bitter gourd was 0.72 and 1.41 mg kg-1 and residues persisted up to 15 and 20 days with a half-life of 2.44 and 2.79 days at X and 2X doses, respectively. Simple decontamination techniques were found to reduce residues to the extent of 30 to 80 per cent. The reduction of chlorantraniliprole residues in bitter gourd juice was 40-50 per cent by different washing techniques. The estimated level of Risk quotient indicated (&lt;1) chlorantraniliprole residues pose no dietary risk to consumers at the level detected.

Dissipation of Four Typical Insecticides on Strawberries and Effects of Different Household Washing Methods

The dissipation patterns of chlorfenapyr, cyenopyrafen, indoxacarb, and spirotetramat on strawberries and the effects of different household washing methods were investigated. A risk assessment was also conducted by monitoring the insecticide residues detected. The concentrations ranged from 0.011 to 0.27 mg/kg for chlorfenapyr, 0.064 to 0.99 mg/kg for cyenopyrafen, 0.042 to 0.53 mg/kg for indoxacarb, and from 0.25 to 1.3 mg/kg for spirotetramat, which were all below the maximum residue limits (MRLs) reported. Soaking the fruit in solution and then rinsing with running water (B) led to better residue removal (40.9 ± 23.7%) than only soaking in solution (A) (24.7 ± 22.5%). However, neither method decreased chlorfenapyr concentrations, suggesting that the physical-chemical properties of chlorfenapyr could also affect its removal on strawberries. Regarding the different washing solutions in method B, 3% vinegar (removal efficiency: 48.7%) and 3% salt (45.7%) were the most efficient, followed by 3% green tea (38.9%), and tap water only (24.6%). Additionally, the estimated risk quotients (RQs) for strawberry consumption for women were about 1.5 times higher than those observed for men, but both were lower than 1, suggesting minimal risk to humans.

Shake table tests on 1:2 reduced scale masonry house with the application of horizontal seismic bands

The safety of people's lives is crucial in structures that provide shelter. Earthquakes are a major natural disaster that have claimed thousands of lives over the years, but other factors can also cause damage to these structures. Building collapses are often due to their inability to endure the seismic loading, not the earthquake itself. Most residential buildings are masonry structures. There are many strategies for enhancing structural behavior, but very little research has been done on masonry structures, which house about 1/3rd of the world's population. This study focuses on characterization of seismic response using shake table tests to assess the dynamic behavior of masonry structures when horizontal seismic bands are applied. Horizontal seismic band is one of the traditional techniques used in masonry structure. Three reduced scale models were constructed with one using a reinforced concrete band, one with a timber band, and one without a band. All models were constructed using extruded earth block and mud mortar, common building materials in developing nations. The models were tested on a shake table using the same loading signal to compare their response behavior. A high-speed camera was also used to capture images; accelerometers and displacement sensors were installed to record the response. Digital Image Correlation (DIC), which provides non-contact optical measurement, has been essential in obtaining full-field measurement. The results showed significant improvement in the seismic response of structures with horizontal seismic bands. The behaviors are compared in terms of natural frequency, damping, energy dissipation, and crack propagation patterns using two types of materials as seismic bands.

A Comprehensive Review of Pesticide Residues in Peppers

Pesticides are chemicals that are used to control pests such as insects, fungi, and weeds. Pesticide residues can remain on crops after application. Peppers are popular and versatile foods that are valued for their flavor, nutrition, and medicinal properties. The consumption of raw or fresh peppers (bell and chili) can have important health benefits due to their high levels of vitamins, minerals, and antioxidants. Therefore, it is crucial to consider factors such as pesticide use and preparation methods to fully realize these benefits. Ensuring that the levels of pesticide residues in peppers are not harmful to human health requires rigorous and continuous monitoring. Several analytical methods, such as gas chromatography (GC), liquid chromatography (LC), mass spectrometry (MS), infrared spectroscopy (IR), ultraviolet-visible spectroscopy (UV-Vis), and nuclear magnetic resonance spectroscopy (NMR), can detect and quantify pesticide residues in peppers. The choice of analytical method depends on the specific pesticide, that is being tested for and the type of sample being analyzed. The sample preparation method usually involves several processes. This includes extraction, which is used to separate the pesticides from the pepper matrix, and cleanup, which removes any interfering substances that could affect the accuracy of the analysis. Regulatory agencies or food safety organizations typically monitor pesticide residues in peppers by stipulating maximum residue limits (MRLs). Herein, we discuss various sample preparation, cleanup, and analytical techniques, as well as the dissipation patterns and application of monitoring strategies for analyzing pesticides in peppers to help safeguard against potential human health risks. From the authors' perspective, several challenges and limitations exist in the analytical approach to monitoring pesticide residues in peppers. These include the complexity of the matrix, the limited sensitivity of some analytical methods, cost and time, a lack of standard methods, and limited sample size. Furthermore, developing new analytical methods, using machine learning and artificial intelligence, promoting sustainable and organic growing practices, improving sample preparation methods, and increasing standardization could assist efficiently in analyzing pesticide residues in peppers.

Dissipation kinetics of co-formulation with two herbicides, clodinafop-propargyl and oxyfluorfen, in/on onion (Allium cepa) samples.

Supervised field trail on dissipation of co-formulation with herbicides clodinafop-propargyl and oxyfluorfen in spring onion showed similar pattern of dissipation during two different seasons. Residues of clodinafop-propargyl reached ≤ limit of quantitation (LOQ, 0.05mgkg-1) on 3rd day after application at both standard and double dose during both the seasons. Oxyfluorfen residues followed first-order kinetics in both the doses during first season with half-life of 0.81 to 3.14days. The residues of clodinafop-propargyl were detected in soil at both the doses during first season. However, residues were ≤ LOQ (0.05mgkg-1) during second season. The residues of oxyfluorfen were detected only in double dose during first season in soil. In all other cases and in onion bulb, residues were ≤ LOQ (0.05mgkg-1) at the time of harvest. As the residues were either ≤ LOQ (0.05mgkg-1) on 3rd day or have a half-life of 3.14days, the co-formulation can be used safely, provided a pre harvest interval (PHI) of 3days is followed. On the basis of maximum residue limits (MRLs) in other commodities and from the data of present study, a default MRL of 0.05mgkg-1 is proposed for both the pesticides.

Compressive Strength of Chipped Rubber Aggregate Concrete: A Review

Concrete is a widely used material for construction therefore, it is necessary to identify materials that are economical, environmentally friendly, easily available, and prevention of environmental damage while sourcing the materials, hence the aim of this study. The current study’s objective is to have a comprehensive study on the previous research identifying the effects of chipped rubber as concrete coarse aggregate and the compressive strength (fc) of the concrete and to identify areas of relevance for better sustainability to reduce the rate of waste rubber and degradation of the environment. To achieve the objectives of this study, a review of previous research works was conducted and analyzed. A comprehensive study on the fc of chipped rubber coarse aggregate concrete (RCAC) was studied by reviewing previous research. The addition of chipped rubber in concrete to a specific ratio can enhance or reduce the concrete fc. But a reduction in the rubber concrete’s fc can be seen when the rubber content ratio exceeded 20%. When the chipped tyre rubber is treated with coupling agents, an increase in the concrete fc can be seen. The use of chipped rubber in concrete production reduces environmental degradation and proves as a step toward the sustainable development goal (SDG). Chipped RCAC mixtures are weaker than regular concrete mixtures. RCAC on the other hand is more ductile and has a better energy dissipation pattern. The fc of concrete was found to be affected by substituting concrete aggregates with rubber.

Persistence of Combination Fungicide, Fluopyram + Tebuconazole Residues and its Risk Assessment in Kidney Bean

Background: Kidney bean is a protein rich legume crop largely cultivated in hilly tracts of India. Fungal diseases are major biotic constraints causing severe yield losses and fluopyram and tebuconazole are most commonly used for the management of powdery mildew and anthracnose diseases. Hence, studies were taken on dissipation pattern and dietary risk assessment of fungicides to establish consumer safety. Methods: A simple QuEChERS analytical method was developed and validated for the analysis of fluopyram its metabolite and tebuconazole in kidney bean immature green pods, mature pods, seeds and soil and analyzed in liquid chromatograph mass spectrometer (LC-MS). The combination fungicide was applied as foliar spray at 125+125 and 250+250 g a.i. ha-1 on kidney bean thrice at 10 days interval. Residues were determined in immature green pods, dry mature pods and soil. Immature green pods were collected on 0 (within 2 hours after last spray), 1, 3, 5, 7, 10, 15 and 20 days after third spray and in dry mature pods and soil collected at the time of harvest. Result: The average recovery and RSD were in the range of 81.63 - 95.48% and 0.55-5.10%, with 0.01 and 0.05 µg mL-1 as LOD and LOQ. The initial concentrations were 0.55 and 1.04 mg kg-1 for fluopyram and 0.57 and 1.03 mg kg-1 for tebuconazole in standard and double dose, respectively. The half-lives were 3.67-4.07 days for fluopyram and 3.86-4.18 days for tebuconazole in standard and double dose. Dietary intake risk of fluopyram and tebuconazole from kidney bean is negligible for adult men, women and children based on RQ values ( less than 1).

Ultra-low cycle fatigue performance of grid structure with bolted spherical joints

This study aimed to investigate the effect of the specification of each grid structure component on the ultra-low cycle fatigue performance of the rod element of a grid structure with bolted spherical joints. Thus, an ultra-low cycle fatigue test of three identical composite steel tube and bolted sphere specimens was performed. The test was performed under three kinds of constant amplitude loading regimes for large axial cyclic plastic strain loads. Based on steel ductility damage and initial geometric defects, a finite element simulation of the test was then conducted using Abaqus/Explicit, which was calibrated according to the test results. In addition, parametric numerical simulations were performed to analyze the effects of different steel tube slenderness ratios, bolt diameters, and steel tube wall thicknesses on the seismic performances of the composite steel tube and bolted sphere specimens. The results indicated that the specimen dissipated energy mainly through material damage in the plastic hinge region in the middle of the steel tube. The steel tube slenderness ratio mainly affected the fatigue life and energy dissipation capacity of the specimen. Further, the ultimate tensile and compressive bearing capacity as well as deformation capacity of the specimen both increased with increasing steel tube wall thickness. Finally, the energy dissipation pattern of the specimen was most sensitive to the bolt diameter; thus, the energy dissipation capacity of the steel tube can be fully utilized only by selecting the bolt specification that matches the rod element.

Numerical Modeling of Liquefaction-Induced Downdrag: Validation against Centrifuge Model Tests

Earthquake-induced soil liquefaction can cause soil settlement around piles, resulting in drag load and pile settlement after shaking stops. Estimating the axial load distribution and pile settlement is important for designing and evaluating the performance of axially loaded piles in liquefiable soils. Commonly used neutral plane solution methods model the liquefiable layer as an equivalent consolidating clay layer without considering the sequencing and pattern of excess pore pressure dissipation and soil settlement. Moreover, changes in the pile shaft and the tip resistance due to excess pore pressures are ignored. A TzQzLiq numerical model was developed using the existing TzLiq material and the new QzLiq material for modeling liquefaction-induced downdrag on piles. The model accounts for the change in the pile’s shaft and tip capacity as free-field excess pore pressures develop or dissipate in soil. The developed numerical model was validated against data from a series of large centrifuge model tests, and the procedure for obtaining the necessary information and data from those is described. Additionally, a sensitivity study on TzLiq and QzLiq material properties was performed to study their effect on the developed drag load and pile settlement. Analysis results show that the proposed numerical model can reasonably predict the time histories of axial load distribution and settlement of axially loaded piles in liquefiable soils both during and postshaking.

Energy-driven fracture and instability of deeply buried rock under triaxial alternative fatigue loads and multistage unloading conditions: Prior fatigue damage effect

Rock failure subjected to respective cyclic loading or unloading have been well investigated, however, the energy mechanism of deeply buried rock under alternative cyclic loading and unloading are not well understood. This work aims to reveal the effect of prior fatigue damage on rock fracture and energy evolution characteristics subjected to triaxial alternative cyclic loads and unloading confining pressure. Testing results show that rock stress strain responses, deformation, energy dissipation, and mesoscopic crack pattern are all impacted by the prior fatigue damage. The incremental radial and volumetric strain at the unloading confining pressure stage (UCPS) is larger than the cyclic loading stage (CLS), and their relationships and the confining pressure are revealed. The total energy, elastic energy, and radial strain energy increases and dissipated energy decreases with the increase of disturbed cycles. The relationship between strain energy and confining stress was established at both the UCPS and CLS, it is found that dissipated energy at the UCPS is larger than at the CLS. A series of post-test CT images reveal the internal failure modes and confirm the effect of the number of disturbed cycles on energy release and dissipation. It is suggested that the consumed energy is not proportional to the crack scale, the formation of shear cracks consumes much more energy than those of tensile cracks.

Symmetric Heat Transfer Pattern of Fuel Assembly Subchannels in a Sodium-Cooled Fast Reactor

The method outlined in this paper is convenient and effective for studying the thermal performance of fuel assemblies cooled with sodium fast reactors using the subchannel procedure. To initially study an optimization model for a symmetric single fuel assembly heat transfer pattern analysis in a fast sodium-cooled reactor based on subchannel calculations, this paper innovatively proposes a subchannel heat transfer analysis method with the entransy dissipation theory, which can solve the limitations and inaccuracies of the traditional entropy method such as poor applicability for heat transfer processes without functional conversion and the paradox of entropy production of heat exchangers. The symmetric distributions of the thermal-hydraulic parameters such as coolant flow rate, coolant temperature, cladding temperature, and fuel pellet temperature were calculated, and the entransy dissipation calculation method corresponding to the fuel assembly subchannels was derived based on the entransy theory. The effect of subchannel differences on the thermal-hydraulic parameters and the symmetric distribution pattern of entransy dissipation during the cooling process of the fuel assembly was analyzed and compared from the symmetrical arrangement of subchannels in the axial and radial directions.

A Free-Space-Based Model for Predicting Peanut Moisture Content during Natural Drying

This study aimed to investigate the water dissipation pattern from peanut pods under natural drying conditions after harvest. The Shandong peanut Luhua 22 was used to examine the effects of varying moisture content, bulk density, and porosity on the relative permittivity of the peanut at a signal frequency of 5.8 GHz. The peanut dielectric constant, porosity, and bulk density were used as inputs and peanut kernel moisture as outputs. Support vector regression (SVR), extreme learning machine (ELM), sparrow search algorithm-support vector regression (SSA-SVR), and sparrow search algorithm-extreme learning machine (SSA-ELM) were used to create a prediction model of peanut kernel moisture content. The results show that the water content of peanut kernels decreased in a fast and then slow manner throughout the drying process and that the water content of kernels was stable at 5–8% at the end of drying. The relative permittivity of peanut kernels increased with an increase in the water content and bulk density but decreased with an increase in porosity. The developed SVR, ELM, SSA-SVR, and SSA-ELM water-content prediction models were validated and analyzed in this study, with the model test set coefficients of determination of 0.936, 0.949,0.984, and 0.994, respectively. In comparison to SVR, ELM, and SSA-SVR, the SSA-ELM root mean square error was reduced by 0.0080, 0.0060, and 0.0012, respectively. According to the findings, the ELM neural network model, which is based on the optimization of the SSA, has an improved prediction accuracy. This prediction model provides a theoretical foundation for the variations in peanut seed moisture content during the natural drying process after harvesting peanuts in Shandong, which will be useful for future peanut storage and transportation.