Effect Of Sampling Time Research Articles

Vacuum-Assisted Headspace Solid Phase Microextraction for Monitoring Ripening-Induced Changes in Tomato Volatile Profile

This work proposes, for the first time, the use of vacuum-assisted headspace solid phase microextraction (Vac-HS-SPME) for studying the free volatiles in tomato fruits. Initially, a comparative optimization between Vac-HS-SPME and regular HS-SPME was conducted, examining the effects of sampling time (15-60 min) and temperature (40 and 60°C) on the extraction of 29 target compounds from tomato puree samples. Compared to regular HS-SPME, sampling under vacuum resulted in the detection of nine additional analytes at 40°C, and an extra three at 60°C. The optimized methods (45 minutes sampling with Vac-HS-SPME at 40°C and regular HS-SPME at 60°C) were then successfully applied for the semi-quantitative comparison of free volatiles during on-plant ripening. These studies revealed an increase in volatiles across the six ripening stages considered (mature green, breaker, turning, pink, light red and red ripe) that was dominated by aldehydes. Compared to HS-SPME, the optimized Vac-HS-SPME showed substantial improvement in extraction efficiencies, and enabled the detection of key volatiles at earlier ripening stages, such as the breaker and turning stages. Overall, compared to the regular method, this study demonstrated that Vac-HS-SPME is a powerful approach that provides additional insights on free volatiles in fruits, even when sampling at lower temperatures.

Prevalence and abundance of plant-parasitic nematodes in New Zealand maize fields: effects of territory, soil orders, crop stage, and sampling time

ABSTRACT Plant-parasitic nematodes (PPNs) are significant agricultural pests that can reduce maize yields. This study examines the prevalence, abundance, and diversity of PPNs in New Zealand maize fields, focusing on the effects of territory, soil orders, crop stages, and sampling times. Seven PPN genera were identified: Pratylenchus spp. (root-lesion), Helicotylenchus spp. (spiral), Meloidogyne spp. (root-knot), Heterodera spp. (cyst), Paratylenchus spp. (pin), Criconemella spp. (ring), and Tylenchus spp. PPNs were present in 98% of the samples, with Pratylenchus spp. being the most prevalent (91%), followed by Helicotylenchus spp. (38%). Compared to Waikato and Manawatu-Whanganui, Canterbury had the highest nematode populations, particularly of Pratylenchus spp. and Helicotylenchus spp. Brown and pallic soils supported higher PPN abundances. Sampling during the maize harvesting stage and late autumn resulted in the highest nematode populations and diversity indices. Pratylenchus spp. populations often exceeded the economic threshold of 500 Pratylenchus kg−1 of soil, suggesting a significant threat to maize yield in New Zealand. The findings highlight the need for further research to assess the impact of Pratylenchus spp. on maize yield and to develop effective management practices for maize cultivation in the country.

Effect of Blood Sampling Time After Colostrum Intake on the Concentration of Metabolites Indicative of the Passive Immunity Transfer in Newborn Dairy Calves.

Due to the synepitheliochorial placental structure, bovines show no maternal antibody flow from mother to fetus during pregnancy, resulting in an agammaglobulemic newborn [...].

Changes in vaginal cytokines concentrations during artificial insemination and natural service in beef heifers

ObjectiveHeifer development is crucial for the optimization of reproductive efficiency in beef production. Heifer development is largely influenced by nutrition. Nutritional status of these heifers can influence immunological responses that are crucial for reproduction. Commercial Angus heifers (n = 9) were utilized, in a pilot study, to elucidate the effects of sampling time (days 0, 7, 14, 21, 28, and 35), pregnancy status, and type of mating on individual cytokine concentrations and cytokine profiles in the vagina following breeding.ResultsCytokine profiles were analyzed using MetaboAnalyst 5.0 and one-way ANOVAs were performed in R Studio to identify differences in individual cytokines based on sampling time, pregnancy status, and type of mating. Cytokine profiles were different (P = 0.05) 7 days after either mating type. Cytokines, IL-1β, IL-17a, MCP-1, and TNFα were different based on the mating type and pregnancy status. Multiple cytokines, IL-1α, IL-1β, IL-6, IL-8, IL-10, IL-17a, VEGFa, and MIP1α, were different between days regardless of pregnancy status. In conclusion, vaginal cytokines differ based on pregnancy status, type of mating, and time which may be indicative of vital pathways that need to be activated for pregnancy.

Efficiencies of filtration sampling and extraction for recovery of viable Staphylococcus aureus bioaerosols

Airborne Staphylococcus aureus is detected in various locations and linked to human infection. Reliable quantification of viable S. aureus bioaerosols by filter-based samplers helps characterize personal exposure, requiring efficient sampling and post-sampling processing. However, the efficiencies of filtration sampling and cell extraction are undetermined for viable S. aureus. In coupled with quantitative PCR and propidium monoazide, the performance of three widely-used samplers (IOM, Button, and Cassette) loaded with polycarbonate (PC) or gelatin filters was evaluated over 30–270 min of sampling and compared to that of BioSampler containing deionized water (DW). Effects of sampler type, filter type, and sampling time on cell recovery efficiency of sampling methods were assessed. Methods to extract cells from filters were also studied. The 1.5-min vortexing in peptone-Tween mixture and 10-min heating in DW were respectively granted optimal for cell extraction from PC and gelatin filters with extraction efficiencies averaged 1.0–1.76 (n = 4). Both Button and IOM with 3-μm gelatin filter performed best to capture S. aureus, significantly greater than Button with 0.8-μm PC by a factor of 9–11 (P < 0.05) and Cassette or IOM with 0.2-μm PC by a factor of 15–79 (P < 0.05). Cassette and IOM with 0.2-μm PC also showed less efficiencies than BioSampler/DW by a factor of 4–16 (P < 0.05). Cell recovery efficiency was not affected by sampling time except for the Button with 0.8-μm PC. Overall, filter type is the most critical factor governing cell recovery efficiency. Button and IOM with gelatin filter and 10-min heating in DW are considered the most efficient filtration sampling and extraction methods for viable S. aureus.

Sample, time, and wording effects on estimating the prevalence of childfree adults: Insights from Japan.

Childfree adults neither have nor want children, but estimates of their prevalence vary widely, leading to ambiguity about how common this family status actually is. The goal of this study is to examine the effects of sample composition, time, and question wording on estimates of the prevalence of childfree adults. We pool 83 nationally representative estimates of the prevalence of childfree adults in Japan since 2000 using meta-regression to identify the influence of sex, marital status, year, and survey question. Prevalence estimates are higher when computed from samples of women than men, from samples of singles than married people, from samples collected more recently, and from surveys asking questions about expectations than wants. Most of the variation in estimates of the prevalence of childfree adults can be attributed to differences in sample composition, time, and question wording. Taking these factors into account, we estimate that over 2.5 million Japanese adults age 18-50, or 5.64% of this population, were childfree in 2020.

Effects of Sampling Time and Depth on Phytoplankton Metrics in Agricultural Irrigation Ponds

Spatiotemporal variations of phytoplankton populations in agricultural irrigation ponds need to be accounted for in order to properly assess water quality. Phytoplankton cell and photosynthetic pigment concentrations are two common metrics used to characterize phytoplankton communities. This work evaluated depth and time of the day as factors affecting discrete sampling of phytoplankton. The abundance of chlorophytes, diatoms, cyanobacteria, flagellates, and dinoflagellates, as well as chlorophyll-a and phycocyanin pigments, were determined in samples taken at the surface and depth, in 0.5 m increments, in three to five spatial replications at 9 a.m., 12 p.m., and 3 p.m. in two ponds in Maryland, USA. Depth was a significant factor for photosynthetic pigment concentration variations in both ponds on most sampling dates and time of day was a significant factor for photosynthetic pigment concentrations in half of the sampling dates. Depth was not a significant factor in cell concentration variations for any of the phytoplankton groups observed, but time of day was a significant factor in 40% of the sampling dates. Two distinct patterns in pigment concentration daily variation were observed. The first featured a continuous increase with depth throughout the day. The second showed maximum concentrations at the surface in the morning changing to maximum concentrations at 0.5 m depth at 12 p.m. and 3 p.m.; these patterns corresponded to different morning solar irradiance levels. This indicates that sampling depth and time can be a significant factor when evaluating photosynthetic pigments and should be accounted for in monitoring programs that rely on pigments for decision-making.

Effect of Sampling Time, Quantification Method, and Tree Sample Pooling on Phytophthora cinnamomi Root Quantities in South African Avocado Orchards.

Phytophthora cinnamomi is a destructive soilborne pathogen causing Phytophthora root rot on avocados worldwide. Little is known about the effect of root sampling time, root quantification method (quantitative real-time PCR [qPCR] versus baiting), and tree sample pooling strategies on the quantification of the pathogen in roots in avocado orchard trees. This was investigated in six avocado orchards in two climatically different production regions (Mooketsi and Letaba) in the Limpopo Province, South Africa, over a 2-year period. Two different tree sample pooling strategies, consisting of either a four-pooled group (four groups each containing five pooled trees) or a single-pooled group (20 trees pooled) per 1 ha, were both shown to be suitable for quantifying P. cinnamomi in tree roots using qPCR or root baiting. P. cinnamomi root quantities from the two tree sample pooling strategies were significantly correlated for both quantification methods. Both quantification methods were suitable for quantifying the pathogen in roots, although qPCR was superior to root baiting at identifying significant differences in P. cinnamomi quantities among root sampling time points. The effect of sampling time was dependent on the investigated year. In 2017, root quantities, which were only evaluated using qPCR, did not reveal a consistent trend of a specific sampling time yielding the highest root quantities for most of the orchards. However, five of the orchards in 2018, based on the qPCR analyses, contained significantly higher P. cinnamomi root quantities in May (late autumn) than in March (early autumn), August (late winter), and October/November (late spring). In 2018, P. cinnamomi root DNA quantities were significantly positively correlated with the number of soil temperature hours at 20 to 24 and 20 to 29°C 2 months preceding the root sampling dates and negatively correlated with the number of hours at 15 to 19°C 2 months preceding root sampling. Our study has identified P. cinnamomi root quantification methods and tree sample pooling strategies, which will be useful for understanding the biology of the pathogen and when disease management strategies should be in place.

Effects of sampling time and location on the geographical origin traceability of protected geographical indication (PGI) Hongyuan yak milk: Based on stable isotope ratios

Hongyuan yak milk is a protected geographical indication (PGI) product of rich nutritional value, which is popular among consumers. Stable isotope ratio analysis (SIRA) is an effective way to protect the authenticity of the geographical origin of PGI products, and it is crucial to study the factors affecting stable isotopes. Firstly, we proved that the SIRA could be used to identify the geographical origin of Hongyuan yak milk, and that the identification accuracy in combination with δ13C and δ18O was 100 %. Secondly, we analyzed the effect of sampling selection on the stable isotopes of Hongyuan yak milk in practical applications, which showed that sampling time influenced the δ13C, δ2H, and δ18O, while the sampling locations did not. There were interactions between the effect of sampling time and location on δ2H and δ18O. These results provide a reliable method for identifying PGI products and also provide new guidance on sampling models.

Effect of Pasteurization and Sampling Time on Some Immunological and Microbial Properties of Bovine Colostrum

This study was conducted in the laboratory of the Ministry of Science and Technology to estimate the immunological characteristics (IgG, IgA, and IgM) and microbial content in bovine colostrum samples on the first, third, and fifth day of birth, and the effect of pasteurization treatments {pasteurization at 63° C / 30 minutes (LTLT) and pasteurization, at 72° C. / 15 second (HTST)}. Also, to determine the antibacterial activity of colostrum against pathogenic bacteria, including Staphylococcus aureus, Escherichia coli, Salmonella typhi, and Klebsiella oxytoca. The results showed that the HTST pasteurization was the most effective in colostrum samples. The results also showed that the immune globulins in colostrum were high on the first day of birth, then gradually decreased with the increase in the period from birth, and the concentration of IgG immune-globulins was highest in bovine colostrum, followed by IgM and then IgA, which reached 475.24, 185.70 and 162.00 ng ml-1 respectively. Also, the pasteurization treatments led to a significant decrease in the concentration of immune globulins compared with the control treatment (un paseurization). As for microbial content in colostrum, the results showed that the total number of bacteria and the number of coliform bacteria were low on the first day of birth and then increased on the third and fifth day of birth, while the average number of lactic acid bacteria was 2.12, 2.23, and 2.04 log CFU ml-1 respectively, and the pasteurization treatments led to a significant decrease in the microbial content in all samples, the results also showed that the colostrum samples were free of S. aureus, E. coli, and S. typhi bacteria. Regarding testing the antibacterial efficacy of colostrum against pathogenic bacterial isolates, the results showed that the highest inhibition of colostrum was on the first day of birth against S. aureus bacteria at a zone diameter of inhibition of 14 mm, followed by E. coli, then S. typhi and K. oxytoca.

The Effect of Papaya Leaf Concentration and Fermentation Time on The Decafeination Process of Robusta Coffee

High level of caffeine in Robusta coffee requires the reduction of level to accommodate person with low caffeine tolerance. The wet fermentation process with papaya leaf extract containing the papain enzyme was used to decaffeinate the coffee. This study aimed to investigate the effects of papaya leaf extract concentration and sampling time on the decaffeination of Robusta coffee green beans. The papaya leaf extract concentration ranged from 10% to 80% (w/v), with fermentation lasting 6 to 72 hours. The caffeine content was measured using a UV-Vis spectrophotometer, and organoleptic tests were performed on 40 untrained panelists. The results showed that both the concentration of papaya leaf extract and the fermentation time influenced the decaffeination. The optimum result was obtained after 48 hours of fermentation with 80% (w/v) papaya leaf extract resulting in a caffeine content of 0.268% (w/w) from an initial content of 1.20% (w/w), representing a 77.82% decrease in caffeine level efficiency. Fermented coffee was preferred by 58% of panellists over unfermented coffee. These findings imply that papain found in papaya leaves can reduce caffeine levels while also improving flavor and aroma.

Comparison of Sampling Designs for Soil Sediment Source Fingerprinting

ABSTRACT Sediment fingerprinting is increasingly being used to provide information that can help guide management decisions at the watershed scale. The objectives of this study were to investigate the implications of different sediment fingerprinting sampling designs on characterizing sediment dynamics in the Beheshtabad Watershed in Chaharmahal va Bakhtiari Province, western Iran. First, nitrogen, organic carbon, phosphorus, potassium, calcium, sodium, zinc, manganese, iron, and lime fingerprints were used to discriminate among four potential sediment sources including agricultural topsoil, rangeland, as well as rainfed and urban lands. Then, the suspended sediment was collected from drainage areas at five sites. Nested and local-location fingerprinting sampling designs were employed to evaluate the influence of geomorphic connectivity and land use on apportionment results by using the same source and sediment data set. By averaging all locations using the nested method, agricultural land with an average of 69% had the highest contribution to sedimentation followed by rainfed land with an average of 19.9%, rangeland with an average of 6.8%, and urban lands with an average of 5.99%. Compared to the mean of the total method samples, the local method showed greater soil loss from agricultural lands and lower soil loss from rangeland and rainfed lands. Generally, surface soil in sediments came from agricultural land use. According to the results, total nitrogen, phosphorus, organic carbon, and calcium were the optimum tracers that correctly distinguished source samples. Overall, each of the two fingerprinting sampling designs provided the same information. Thus, the fingerprinting method can determine the sources of sediments. Given the importance of the fingerprinting method, future studies can focus on determining the appropriate combination of tracers and the effect of sediment sampling time.

Clinical implications of imprecise sampling time for 10- and 30-min thyrotropin-releasing hormone stimulation tests in horses.

The thyrotropin-releasing hormone (TRH) stimulation test is used to diagnose pituitary pars intermedia dysfunction (PPID) using 10- or 30-min protocols. Imprecise sampling time for the 10-min protocol can lead to misdiagnoses. To determine the effect of imprecise sampling time for the 30-min protocol of the TRH stimulation test. In vivo experiment. Plasma immunoreactive adrenocorticotropin (ACTH) concentrations were measured 9, 10, 11, 29, 30 and 31 min after intravenous administration of 1 mg of TRH in 15 control and 12 PPID horses. Differences in ACTH concentrations between sampling times, variability in ACTH concentrations between protocols, and diagnostic classification of PPID were assessed using Friedman's test, Bland-Altman plots, and Fisher's exact test, respectively, with 95% confidence intervals reported and significance set at p < 0.05. Imprecise sampling time resulted in variable ACTH concentrations, but significant differences in absolute ACTH concentrations were not detected for imprecise sampling within each protocol or between protocols. Imprecise sampling changed PPID diagnostic classification for 3/27 (11 [4-28] %) horses for both protocols. Using the 30-min protocol as a reference, 1/12 (8 [1-35] %) horses returned a negative test result and 5/12 (42 [19-68] %) horses returned equivocal test results that would be considered positive in practice due to the presence of supportive clinical signs. Limited sample size and inter-horse variability reduced the ability to detect small but potentially relevant differences. Overall, the impact of imprecise sampling was not significantly different between the 10- and 30-min TRH stimulation test protocols. However, diagnostic classification for PPID would have varied between the 10- and 30-min protocols in this population, if clinical signs had been ignored. Precise timing during TRH stimulation tests and contextual interpretation of ACTH concentrations remain fundamental for the diagnosis of PPID.

The Use of Model-Predicted Internal States from Locally Linear, Gain-Scheduled, Reduced-Order Physics-Based Models in Model-Predictive Control Strategies

The objective of the research is to develop reduced-order state-space models that can predict internal states that are not directly observable with existing sensors. In doing so, battery management systems (BMS) can make real-time control decisions based upon sensor inferences. For example, estimating local electrode Li and electrolyte Li-ion concentrations or local electrostatic potential differences between electrode and electrolyte phases offer valuable knowledge in predicting behaviors such as Li plating, dendrite growth, or electrode fracture. Such indirect predictive capabilities, for example, can enable fast-charging protocols that avoid damage mechanisms.This talk explores the mathematical feasibility of estimating local Li concentrations and electrostatic potentials using observed current-voltage sequences. The approach for determining internal battery states begins with an estimator that uses observed input-output data from a physics-based reduced-order state-space model. If the model satisfies the property of observability, a sufficiently long window of input-output data can predict unique internal-state trajectories that are compatible with the observable data. The research considers understanding the effects of sampling time and state of charge on internal-state observability.Efficient estimation algorithms must incorporate battery physics and chemistry yet be sufficiently simple as to run in real-time on a battery management system (BMS). The present research first develops a physics-based pseudo-two-dimensional (P2D) model, which describes battery thermodynamics, transport, and kinetics, results in a system of nonlinear, coupled, differential-algebraic equations that can be solved computationally, but too slow for real-time implementation. The P2D model is then reduced to a gain-scheduled, locally linear, state-space model that can be run in real-time. Both models are implemented within the MATLAB/Simulink framework that facilitates development and evaluation of control strategies.

Experimental study of mutual effects of high carrier frequency, dead-time and control sample time on IPMSM core loss under SiC inverter excitation

This paper experimentally analyzes the core loss characteristics of an interior permanent magnet synchronous motor (IPMSM) excited by a SiC inverter with the sinusoidal pulse-width modulation (PWM) and high modulation index of 1.1 considering the mutual effects of the high carrier frequencies of up to 200 kHz, different dead-times of 250 and 1000 ns, control sample times of 100–1000 μs, and stator core temperature. The experimental IPMSM drive system is operated in load condition with a torque of 1.05 Nm and rotational velocity of 1500 rpm. Furthermore, the ringing phenomenon and rise time in the motor voltage are measured and analyzed using a high-resolution oscilloscope that has a superior sampling rate of up to 5 giga-samples per second (GS/s), which helps to thoroughly examine the impact of the SiC inverter excitation on the motor core loss. The relations of the total harmonic distortion (THD) of the measured motor voltage and current and the distortions in the magnetic flux density through the stator core to the IPMSM core loss properties are also evaluated. Lastly, explanations and insights based on physics of the obtained results are presented.

Microbial fertilizer regulates C:N:P stoichiometry and alleviates phosphorus limitation in flue-cured tobacco planting soil

Fertilization can be optimized and managed during the flue-cured tobacco growing period by studying the response of soil and microbial biomass stoichiometric characteristics to fertilization. In this study, we investigated the effect of compound fertilizers combined with microbial fertilizer treatments on the stoichiometric characteristics of the rhizosphere soil and the limitations of microbial resources during the flue-cured tobacco growing period. The results indicated that soil and microbial C:N:P varied greatly with the growing period. The effect of sampling time was usually greater than that of fertilization treatment, and microbial C:N:P did not vary with the soil resource stoichiometric ratio. The microbial metabolism of the tobacco-growing soil was limited by phosphorus after extending the growing period, and phosphorus limitation gradually increased from the root extension to the maturation periods but decreased at harvest. The rhizosphere soil microbial nitrogen and phosphorus limitations were mainly affected by soil water content, soil pH, microbial biomass carbon, and the ratio of microbial biomass carbon to microbial biomass phosphorus. Applying microbial fertilizer reduced phosphorus limitation. Therefore, applying microbial fertilizer regulated the limitation of microbial resources by affecting the soil and microbial biomass C:N:P in flue-cured tobacco rhizosphere soils.

Bacterial communities along parrot digestive and respiratory tracts: the effects of sample type, species and time

Digestive and respiratory tracts are inhabited by rich bacterial communities that can vary between their different segments. In comparison with other bird taxa with developed caeca, parrots that lack caeca have relatively lower variability in intestinal morphology. Here, based on 16S rRNA metabarcoding, we describe variation in microbiota across different parts of parrot digestive and respiratory tracts both at interspecies and intraspecies levels. In domesticated budgerigar (Melopsittacus undulatus), we describe the bacterial variation across eight selected sections of respiratory and digestive tracts, and three non-destructively collected sample types (faeces, and cloacal and oral swabs). Our results show important microbiota divergence between the upper and lower digestive tract, but similarities between respiratory tract and crop, and also between different intestinal segments. Faecal samples appear to provide a better proxy for intestinal microbiota composition than the cloacal swabs. Oral swabs had a similar bacterial composition as the crop and trachea. For a subset of tissues, we confirmed the same pattern also in six different parrot species. Finally, using the faeces and oral swabs in budgerigars, we revealed high oral, but low faecal microbiota stability during a 3-week period mimicking pre-experiment acclimation. Our findings provide a basis essential for microbiota-related experimental planning and result generalisation in non-poultry birds.

Rumen protozoa population and carbohydrate-digesting enzymes in sheep fed a diet supplemented with hydrolysable tannins

Abstract The aim of the study was to compare the effect of adding different sources of hydrolysable tannins to the sheep diet on protozoa population and carbohydrate digestion in the rumen. The study was performed in 3 Polish Lowland ewes fistulated to the rumen in a 3 × 3 Latin square design. Control sheep (CON) received (g/d): meadow hay (600), barley meal (300), soybean meal (100) and vitamin-mineral premix (20). Sheep from the experimental groups were additionally administered 12.6 g/kg DM oak bark extract (OAK) and 3.91 g/kg DM tannic acid (TAN ). The net consumption of tannins was approx. 0.4% DM for both additives. Regarding the count of protozoa, a significant interaction between diet and sampling time was documented for all ciliates (P&lt;0.01), with a significant effect of both factors when considered separately. Experimental diets reduced the number of total protozoa and Entodinium spp. (before feeding, 2 and 4 h after feeding; P&lt;0.01), while increasing the abundance of Isotricha spp. population (4 h after feeding; P&lt;0.01) in the rumen. Interestingly, the count of Ophryoscolex spp. after feeding the TAN diet increased before feeding and 2 h after feeding in comparison to the CON and OAK groups, respectively, and subsequently decreased compared to the CON diet (4 and 8 h after feeding, P&lt;0.01). A significant interaction between the diet and sampling time was observed for xylanolytic activity (P&lt;0.01) in the rumen, with a significant effect of sampling time, which decreased its activity in CON (after feeding) and OAK sheep (2 h after feeding; P&lt;0.01). For amylolytic activity (P&lt;0.10), there was a trend towards a significant interaction between experimental factors, with a significant effect on both diet and sampling time. Detailed analysis showed that the TAN diet significantly reduced amylolytic activity 2 h after feeding compared to the CON group (P&lt;0.05). In conclusion, the TAN diet significantly reduced the number of total protozoa and Entodinium spp., which consequently reduced amylolytic activity in the rumen, without any significant effect on pH and carbohydrate fermentation in the rumen.

Study on the Equivalence of Metallic-Cerium-Simulated Uranium-Aerosol Generation under Fire

Uranium aerosols are released from uranium-containing materials in high-temperature environments caused by nuclear accidents or other processes. Research on the generation characteristics of uranium aerosols under such conditions is an important part of nuclear-safety analysis. In this experiment, the similarity between metal cerium aerosols and uranium material aerosols was evaluated from the aspects of particle size distribution and source term. Combined with the experiment data, the effect of air flow rate and sampling time is discussed. The calculation result of the air release fraction (ARF) is 6.07 × 10−3–4.8 × 10−2, and the respirable fraction (RF) is 0.810–0.978, respectively, showing that the size distribution of particles and ARF of the cerium aerosol are different from the results of the uranium aerosols in the literature, while the RF is similar to the results obtained by using the uranium–niobium alloy in the literature.

A New Simulation‐Optimization Framework for Estimation of Submarine Groundwater Discharge Based on Hydrodynamic Modeling and Isotopic Data

AbstractEstimation of submarine groundwater discharge (SGD) has traditionally relied on isotopic mass balance calculation, which is a form of regional box modeling. Here we propose an entirely new approach for SGD estimation by coupling a general marine hydrodynamic simulation model with a global optimization algorithm. The newly developed approach has the distinct advantage of being able to map the spatial distribution of SGD. The results of this study show that the estimated SGD exhibits a strong spatial heterogeneity. Furthermore, this study underscores the important effect of isotope sampling time on SGD estimation. Thus, the fluctuation of seawater level and a lag in isotope activity to water level changes should be considered to assure the representativeness of measured isotope activities. Overall, the simulation‐optimization framework adds a versatile and powerful new tool for more detailed SGD estimation.