Saturation Point Research Articles

Perceptual saturation in deterrence: Examining the nonlinear relationships between arrest rate signal and perceptions of risk and reward

PurposeExamining the functional form of the relationships between arrest rate signal and perceptions of risk and reward among active young offenders previously adjudicated of a serious offense. MethodsGeneralized additive mixed models were used to analyze data from 745 individuals in the Pathways to Desistance study. ResultsIncreasing arrest rate had a positive but diminishing nonlinear effect on risk and a negative but approximately linear effect on rewards. A saturation point was observed in the influence of arrest rate on perceptions of risk, where further increases in arrest rate did not correspond to appreciable changes in perceptions of risk. ConclusionsThe findings suggest a potential upper limit to the effectiveness of increased arrest rate in deterring crime through increasing risk perceptions and underscore the need for policy strategies beyond increasing experienced punishment certainty. However, the findings also highlight potential methodological concerns of using arrest rate as a predictor of perceptions, especially among a sample with large variation in offending frequencies. Research should account for the nonlinearity between punishment and perceived risk and reward, especially in samples with heterogeneous offending experience.

Research on the influence of dynamic contact angle of mercury meniscus on the interpretation of rock pore throat radius in mercury intrusion experiments

Addressing the lack of measurement methods for dynamic contact angles of mercury meniscus in mercury intrusion porosimetry experiments and the unclear understanding of the impact of dynamic contact angles on the interpretation of pore throat radius in rocks, a new type of closed mercury intrusion characteristic curve (O-R curve) is constructed utilizing the withdrawal curve O and the secondary injection curve R obtained from the experiments. Based on the excellent wetting and de-wetting correlation characteristics at the equal mercury saturation points on this curve, a method for measuring the dynamic contact angles of mercury meniscus (O-R loop method) is established. Taking the Chang 63 tight oil reservoir samples from the Nanliang Oilfield in the Ordos Basin of China as an example, this method is applied to investigate the dynamic contact angles of mercury meniscus in mercury intrusion porosimetry experiments and the impact on the interpretation of pore throat radius in rocks. The results indicate that the dynamic contact angles of mercury meniscus changes significantly during the experiments, which cannot be ignored. And the smaller pore throats lead to more severe deformation of mercury meniscus, resulting in higher wetting resistance coefficients and hysteresis angles. Calculations reveal that the pore throat radius interpreted using the modified Washburn equation (which adopts dynamic contact angles) are generally larger than those interpreted using the conventional Washburn equation (which adopts static contact angles), with relative errors ranging from 12.2% to 54.7%. The smaller the pore throats, the larger the relative errors. The analysis shows that the conventional Washburn equation significantly underestimates the reservoir pore throat radius due to the neglect of the dynamic contact angle, while the modified Washburn equation provides more accurate interpretation. Overall, this research provides a method for calculating the dynamic contact angle in mercury intrusion porosimetry experiments and has important reference significance for the accurate interpretation of rock pore throat radius.

Towards an ecosystem capacity to stabilise organic carbon in soils.

Soil organic carbon (SOC) accrual, and particularly the formation of fine fraction carbon (OCfine), has a large potential to act as sink for atmospheric CO2. For reliable estimates of this potential and efficient policy advice, the major limiting factors for OCfine accrual need to be understood. The upper boundary of the correlation between fine mineral particles (silt + clay) and OCfine is widely used to estimate the maximum mineralogical capacity of soils to store OCfine, suggesting that mineral surfaces get C saturated. Using a dataset covering the temperate zone and partly other climates on OCfine contents and a SOC turnover model, we provide two independent lines of evidence, that this empirical upper boundary does not indicate C saturation. Firstly, the C loading of the silt + clay fraction was found to strongly exceed previous saturation estimates in coarse-textured soils, which raises the question of why this is not observed in fine-textured soils. Secondly, a subsequent modelling exercise revealed, that for 74% of all investigated soils, local net primary production (NPP) would not be sufficient to reach a C loading of 80 g C kg-1 silt + clay, which was previously assumed to be a general C saturation point. The proportion of soils with potentially enough NPP to reach that point decreased strongly with increasing silt + clay content. High C loadings can thus hardly be reached in more fine-textured soils, even if all NPP would be available as C input. As a pragmatic approach, we introduced texture-dependent, empirical maximum C loadings of the fine fraction, that decreased from 160 g kg-1 in coarse to 75 g kg-1 in most fine-textured soils. We conclude that OCfine accrual in soils is mainly limited by C inputs and is strongly modulated by texture, mineralogy, climate and other site properties, which could be formulated as an ecosystem capacity to stabilise SOC.

Precise synthesis of In–Bi alloy nanodroplets through controlled surface reactions on a Si(111) surface at ambient temperature

The synthesis of alloy nanocatalysts with controllable sizes and shapes is a critical prerequisite for vapor–liquid–solid (VLS) growth of one-dimensional nanostructures. In this work, we comprehensively examined surface reactions between evaporated In atoms and a Bi thin film on a Si(111) surface at ambient temperature. InBi2 liquid nanodroplets nucleate and grow during initial vapor–solid (VS) reaction between the In vapor and surface Bi atoms, and the reaction proceeds until a saturation point is reached, following which InBi2 begins to catalyze subsequent VLS growth of various nanocrystals under persistent In-beam flux. The scaled size distribution of individual InBi2 nanodroplets could be explained adequately using the classical capillary nucleation theory, which suggests that the simultaneous homogeneous nucleation of InBi2 nanodroplets occurs during the vapor–solid (VS) reaction of In and Bi.

Association between depression and infertility based on the PHQ-9 score: Analyses of NHANES 2013-2018.

Over the past decade, nationally representative research elucidating the association between depression and infertility has been notably lacking. Our study aimed to investigate the association between depression and infertility among women of childbearing age. Our study encompassed 3,654 women aged 18 to 45 years from the National Health and Nutrition Examination Survey (NHANES) 2013-2018. Infertility was defined as a positive response to the query: "Have you attempted to conceive for a minimum of one year without achieving pregnancy?" Depression was evaluated by the Patient Health Questionnaire (PHQ-9) score (range, 0-27). Multiple logistic regression analyses and subgroup analyses stratified by age and race/ethnicity were conducted to investigate the association between depression and infertility. Furthermore, fitted smoothing curves and threshold effect analysis were utilized to depict the nonlinear relationship. Total PHQ-9 score was associated with infertility in the fully adjusted model (OR 1.04, 95% CI 1.01-1.07, P = 0.010), and this relationship exhibited a non-linear pattern, reaching a saturation point at 13, as substantiated by the fitting of smoothed curves. Additionally, the association remained robust when stratified by age but not by race/ethnicity. Cross-sectional design and recall biases. In this cross-sectional study, depression was associated with infertility among women of childbearing age in the fully adjusted models. This observed association holds potential relevance for clinicians tasked with enhancing psychological well-being during infertility management strategies.

Response of photosynthetic characteristics and yield of grape to different CO2 concentrations in a greenhouse.

Due to the enclosed environment of greenhouse grape production, the supply of CO2 required for photosynthesis is often insufficient, leading to photosynthetic downregulation and reduced yield. Currently, the optimal CO2 concentration for grape production in greenhouses is unknown, and the precise control of actual CO2 levels remains a challenge. This study aims to investigate the effects of different CO2 concentrations on the photosynthetic characteristics and yield of grapes, to validate the feasibility of a CO2 gas irrigation system, and to identify the optimal CO2 concentration for greenhouse grape production. In this study, a CO2 gas irrigation system combining CO2 enrichment and gas irrigation techniques was used with a 5-year-old Eurasian grape variety (Vitis vinifera L.) 'Flame Seedless.' Four CO2 concentration treatments were applied: 500 ppm (500 ± 30 µmol·mol-1), 700 ppm (700 ± 30 µmol·mol-1), 850 ppm (850 ± 30 µmol·mol-1), and 1,000 ppm (1,000 ± 30 µmol·mol-1). As CO2 concentration increased, chlorophyll a, chlorophyll b, and carotenoids in grape leaves all reached maximum values at 700 ppm and 850 ppm during the same irrigation cycle, while the chlorophyll a/b ratio was lower than at other concentrations. The net photosynthetic rate (Pn) and water use efficiency (WUE) of grape leaves were the highest at 700 ppm. The transpiration rate and stomatal conductance at 700 ppm and 850 ppm were significantly lower than those at other concentrations. The light saturation point and apparent quantum efficiency reached their maximum at 850 ppm, followed by 700 ppm. Additionally, the maximum net photosynthetic rate, carboxylation efficiency, electron transport rate, and activities of SOD, CAT, POD, PPO, and RuBisCO at 700 ppm were significantly higher than at other concentrations, with the highest yield recorded at 14.54 t·hm-2. However, when the CO2 concentration reached 1,000 ppm, both photosynthesis and yield declined to varying degrees. Under the experimental conditions, the optimal CO2 concentration for greenhouse grape production was 700 ppm, with excessive CO2 levels gradually inhibiting photosynthesis and yield. The results provide a theoretical basis for the future application of CO2 fertilization and gas irrigation techniques in controlled greenhouse grape production.

Exploring the Psychosocial Challenges Experienced by Teenage Student Mothers in Senior High Schools in Asene Manso Akroso District, Ghana.

Purpose: This study explored the psychosocial challenges experienced by teenage student mothers in senior high schools in Asene Manso Akroso District, Ghana. Methodology: The qualitative research approach was employed to understand and explore the psychosocial challenges experienced by teenage student mothers in senior high schools in Asene Manso Akroso District. Purposive sampling method was used to select the population of the study. Data saturation point was used to select a sample of twelve teenage student mothers from a population of fifty-five teenage student mothers from the two senior high schools in the district. Interview guide was used for the data collection and content analysis was used to analyse the data. Findings: The study revealed that teenage student mothers were ridiculed and rejected by their peers in school. It was also found that the teenage student mothers felt lonely and isolated as most of their friends shunned them for fear of being classified in the same category with teen mothers. Unique contribution to theory, practice and policy: It is therefore, recommended that guidance and counselling units in senior high schools should liaise with school authorities to provide academic and social support systems to help them adjust into the school system

Synergistic influences of ground granulated blast-furnace slag and silica fume on the viscosity of extremely low W/B cement pastes

Particularly with a low water/binder ratio, the synergistic effects of supplemental cementitious materials (SCMs) have drawn a lot of interest in improving the characteristics of cement-based products. The effects of SCMs, such as silica fume (SF) and ground granulated blast furnace slag (GGBS) with varying fineness, on the setting time, saturation point, and viscosity of ultra-high performance cement pastes (UHPCP), are examined experimentally in this work. 56 mixes with various SF and BFS substitutions and exceptionally low water/binder ratios (0.16, 0.20) were used in the experiments. This work demonstrates the synergistic effects of SCMs from several angles, including the UHPCP fresh characteristics. It is shown that carefully regulating the water/binder ratio, the BFS fineness, and most significantly the addition of an ideal SF content will have a beneficial synergistic effect on the fresh qualities of UHPCP. However, utilizing high BFS replacement is discouraged as it may have a negative impact on viscosity.

From few large to many small investments: lessons for adaptive irrigation development in an uncertain world

Conventional approaches to irrigation development involve large lumpsum investments in big infrastructure that cannot adapt to changing climate and socio-economic conditions. There is an urgent need for alternative ways of investing in smallholder irrigation in Sub-Saharan Africa (SSA) that are adaptive and avoid capital lock-in. Adaptive Investment Pathways (AdIP), inspired by the Dynamic Adaptive Policy Pathways (DAPP) concept, proposes stepwise investments to support smallholder irrigation development. AdIP builds resilience to future shocks through dynamic and flexible investment plans instead of investing in single static solutions. To develop an empirical grounding for operationalizing AdIP, we draw lessons from three case studies representing different stages of irrigation development along shallow sand river aquifers in Kenya and Zimbabwe. We retrospectively analyse the nature of investments at farm and landscape scales, and the type of risks and opportunities that farmers respond to. We find that in face of risks, farmers diversify their livelihoods, make small investments incrementally especially in response to opportunities and risks created by external triggers, and pause or reorient activity when they reach saturation points, i.e., biophysical or socio-political limits to their development objective, here irrigation development. Governments and external agencies can support smallholder irrigation development in SSA through targeted landscape scale investments that address saturation points faced by smallholders. This requires a robust participatory monitoring framework to identify and respond to saturation points, and a re-thinking of financing mechanisms which do not measure progress against a fixed schedule of investments, but instead measure continuous progress towards the development objective.

Combining Desulfurisation Gypsum and Polyacrylamide to Reduce Soil Salinity and Promote Buckwheat Photosynthesis

ABSTRACTSoil salinisation poses a significant threat to global agricultural production and food security. China is among the countries most severely impacted by soil salinisation. To investigate the improvement technology for saline–alkali stress in buckwheat, a typical multigrain crop in northwest China, a coupling regulation study using desulfurisation gypsum and polyacrylamide (PAM) was conducted in 2019 and 2020. Desulfurisation gypsum was applied at 0, 5.5, 11, 16.5 and 22 kg·ha−1, while PAM was applied at 0, 15, 30, 45 and 60 kg·ha−1. The results demonstrated that applying 11 t·ha−1 desulfurisation gypsum and 30 kg·ha−1 PAM effectively reduces soil salinity and pH, averaging 81.79% and 6.07%, respectively. Furthermore, it did not cause soil heavy metal pollution and created the best soil environment for buckwheat growth. Among the models tested, the nonrectangular hyperbolic model was the most accurate in describing buckwheat's photosynthetic light response. The optimal treatment for achieving the best photosynthetic performance—measured by apparent quantum efficiency, maximum net photosynthetic rate, light compensation point, light saturation point, dark respiration rate, stomatal conductance, intercellular CO2 concentration, transpiration rate, leaf water use efficiency and yield—was achieved through applying 11 t·ha−1 desulfurisation gypsum and 30 kg·ha−1 PAM. Therefore, desulfurised gypsum and PAM should be applied at 11 t·ha−1 and 30 kg·ha−1, respectively, to improve buckwheat's adaptability to different light intensities while promoting its photosynthetic response in saline–alkali soils. This study provides an effective technical scheme for reducing salt and promoting the growth of crops under salinity stress, which is of great significance for improving salinity land in arid areas.

Analyzing Misinformation Claims During the 2022 Brazilian General Election on WhatsApp, Twitter, and Kwai

Abstract This study analyzes misinformation claims sent to fact-checking organizations on WhatsApp during the 2022 Brazilian general election and compares them with content from Twitter and Kwai (a popular video-sharing application similar to TikTok). Given the democratic importance of accurate information during elections, multiple fact-checking organizations collaborated to collect and respond to misinformation via WhatsApp tiplines and power a fact-checking feature within a chatbot operated by Brazil’s election authority, the Tribunal Superior Eleitoral (TSE). We partnered with TSE and three fact-checking organizations and collected social media data to study how misinformation claims propagate across platforms. We observed little overlap between the users of different fact-checking tiplines and a high correlation between the number of users and the amount of unique content, suggesting that WhatsApp tiplines are far from reaching a saturation point. Similarly, we also found little overlap in content across platforms, indicating the need for further research with cross-platform approaches to identify misinformation dynamics.

Photosynthetic responses of switchgrass to light and CO2 under different precipitation treatments

AbstractSwitchgrass (Panicum virgatum L.) is a prominent bioenergy crop with robust resilience to environmental stresses. However, our knowledge regarding how precipitation changes affect switchgrass photosynthesis and its responses to light and CO2 remains limited. To address this knowledge gap, we conducted a field precipitation experiment with five different treatments, including −50%, −33%, 0%, +33%, and +50% of ambient precipitation. To determine the responses of leaf photosynthesis to CO2 concentration and light, we measured leaf net photosynthesis of switchgrass under different CO2 concentrations and light levels in 2020 and 2021 for each of the five precipitation treatments. We first evaluated four light and CO2 response models (i.e., rectangular hyperbola model, nonrectangular hyperbola model, exponential model, and the modified rectangular hyperbola model) using the measurements in the ambient precipitation treatment. Based on the fitting criteria, we selected the nonrectangular hyperbola model as the optimal model and applied it to all precipitation treatments, and estimated model parameters. Overall, the model fit field measurements well for the light and CO2 response curves. Precipitation change did not influence the maximum net photosynthetic rate (Pmax) but influenced other model parameters including quantum yield (α), convexity (θ), dark respiration (Rd), light compensation point (LCP), and saturated light point (LSP). Specifically, the mean Pmax of five precipitation treatments was 17.6 μmol CO2 m−2 s−1, and the ambient treatment tended to have a higher Pmax. The +33% treatment had the highest α, and the ambient treatment had lower θ and LCP, higher Rd, and relatively lower LSP. Furthermore, precipitation significantly influenced all model parameters of CO2 response. The ambient treatment had the highest Pmax, largest α, and lowest θ, Rd, and CO2 compensation point LCP. Overall, this study improved our understanding of how switchgrass leaf photosynthesis responds to diverse environmental factors, providing valuable insights for accurately modeling switchgrass ecophysiology and productivity.

Study on the spectrum model of light response of Manglietia yuyuanensis

Abstract To study the spectral characteristics of the photosynthetic response of Manglietia yuyuanensis, this paper uses a self-developed monochromatic light generator to generate 22 kinds of monochromatic light, and measures the net photosynthetic rate of Manglietia yuyuanensis under the irradiation of 22 kinds of monochromatic light, then obtains its light response curve under different wavelengths. The right-angle hyperbolic correction model was used to fit the light response curves under each kind of monochromatic light, and the completed spectrum of the light saturation points of Manglietia yuyuanensis was obtained. It makes up for the disadvantage that the self-developed monochromatic light generator cannot detect the light saturation point of the plant under some monochromatic light due to the low radiation intensity. This paper supposes that the coefficients α, β, γ, and Rd in the right-angle hyperbolic correction model are functions related to the wavelength λ, then fits a Gaussian function of α, β, γ, and Rd to wavelength λ. From the fitting results, the fitting degree of α, β, and γ can reach 0.8 or more, which indicates the fitting effect is good. The fitting degree of Rd is about 0.5. According to the fitting function, a new photosynthesis model related to wavelength and light radiation was obtained, and the fitting degree of the data by the new model is good, laying a foundation for future research on photosynthetic response curves of other plants.

Evaluation of three granular activated carbon filters for the treatment of collections foul air entering a water resource recovery facility.

The treatment of raw foul air that could escape to the atmosphere from the head space of the incoming wastewater sewer lines into a Southern California Water Resource Recovery Facility was evaluated by using a 1/20th scale pilot unit consisting of three different granular activated carbon filter technologies, operating side by side, under similar operating conditions, each having an average 3.8-s contact time. The three activated carbon filters contained each 0.07 m3 of coconut, coal, and coconut mixed with permanganate media. The foul air entering the granular activated carbon filters contained 82% to 83% relative humidity. No moisture removal mechanism was used prior to treatment. The removal of six different odor characters from eight chemical odorants present in the foul air were assessed. These were rotten egg (hydrogen sulfide), rotten vegetables (methyl mercaptan), canned corn (dimethyl sulfide), rotten garlic (dimethyl disulfide), earthy/musty (2-methyl isoborneol and 2-isopropyl 3-methoxy pyrazine), and fecal (skatole and indole). This is the first time a study evaluates the removal of specific odors by simultaneously employing sensory analyses using the odor profile method, which defines the different odor characters and intensities, together with chemical analyses of the odorants causing these odors. The results show that the three granular activated carbon filters, before hydrogen sulfide breakthrough, provided significant improvement in odor intensity and odorant removal. Breakthrough was reached after 57 days for the coconut mixed with permanganate, 107 days for the coconut, and 129 days for the coal granular activated carbon filter. Breakthrough (the critical saturation point of the activated carbon media) was considered reached when the hydrogen sulfide percentage removal diminished to 90% and continued downward. The coconut mixed with permanganate granular activated carbon filter provided the best treatment among the media tested, achieving very good reduction of odorants, as measured by chemical analyses, and reasonable removal of odor intensities, as measured by the odor profile method. The coconut mixed with permanganate granular activated carbon is recommended for short-term odor control systems at sewer networks or emergency plant maintenance situations given its shorter time to breakthrough compared with the other granular activated carbons. The coal and coconut granular activated carbon filters are generally used as the last stage of an odor treatment system. Because of the observed poor to average performance in removing odorants other than hydrogen sulfide, the treatment stage(s) prior to the use of these granulated activated carbons should provide a good methyl mercaptan removal of at least 90% in order to avoid the formation of dimethyl disulfide, which, in the presence of moisture in the carbon filter, emit the characteristic rotten garlic odor. The differences observed between the performances based on odorant removal by chemical analysis compared with those based on sensorial analyses by the odor profile method indicate that both analyses are required to understand more fully the odor dynamics. PRACTITIONER POINTS: Three virgin granulated activated carbon media were evaluated in a field pilot unit using raw collections foul air. Coal, coconut, and coconut mixed with permanganate were tested until breakthrough. Samples were analyzed both chemically (odorants) and sensorially (odors). Coconut mixed with permanganate proved to be the media that better reduced odorants and odors.

Attenuation of the effect of salinity on redwood (Caesalpinia platyloba) by saline compost

The objective of this research is to evaluate the effect of saline compost on the attenuation of salinity stress in palo colorado (Caesalpinia platyloba). A representative sample of saline soil was taken at Ciudad Universitaria Intercultural, sieved (mesh < 5mm) and composted with cattle manure and Cynodon dactylon garden grass pruning, in a 3:1:1 ratio (stubble: manure: saline soil), for 120 days, the characterization consisted of measuring the bulk density (DA), saturation point, pH and EC of the saturated paste extract. The effect of different concentrations of NaCl on the in vitro germination of palo colorado seeds was evaluated in a randomized complete block design with two substrates (blocks), B1) sand-perlite; B2) sand-perlite-salt compost, five treatments 0 M, 0.3 M, 0.4 M, 0.5 M and 0.6 M of NaCl, eight replicates per treatment. The control irrigation was with distilled water. The plants transference to polyethylene cups was fifteen days after sowing; the cups had the same substrate mixture. The variables measured were survival, leaf biomass and dry root biomass. The EC decreased during composting, from 9.45 dS/m low to 2.4 dS/m; the pH of the samples did not show a significant difference. It is concluded that neither the substrate nor the NaCl concentration significantly influenced the germination of palo colorado seeds, and that the saline compost had no effect on the mitigation of salt stress in palo colorado plants.

Optimization and mass transfer analysis under the ribs of multi-serpentine flow fields

This study aims to enhance the performance of Proton Exchange Membrane Fuel Cell (PEMFC) by optimizing the design of a three-channel serpentine flow field. The focus is on the introduction of sub-channels beneath the flow field ribs, utilizing the pressure differential between the main and sub-channels to strengthen lateral convection under the ribs, thus achieving uniform distribution of reaction gases. Using Computational Fluid Dynamics (CFD) methods, the performance of traditional and optimized flow fields were compared across various metrics. The results show that the introduction of sub-channels significantly improves gas mass transfer efficiency, enhances the uniformity of oxygen concentration and current density, and optimizes water content on the proton exchange membrane. At a voltage of 0.5 V, the Improved Serpentine Flow Field (ISCF) exhibits a notable enhancement in current density, increasing from 1.501 A/cm2 in the Traditional Serpentine Flow Field (TCSF) to 1.654 A/cm2 in the ISCF. This represents a significant 10 % increase in current density. Concurrently, the uniformity index climbs from 0.84 to 0.898, marking a 7 % improvement in uniformity. Furthermore, the ISCF design achieves a substantial reduction in pressure drop, decreasing from 1631 Pa to 1212 Pa, a reduction of 26 %. Additionally, the expansion of sub-channel width markedly boosts cell performance, whereas the Increase in sub-channel height reaches a saturation point beyond a certain threshold, indicating an optimal range for dimensional adjustments.

Influence of hydrogen sulfide on gas-water interface in underground hydrogen storage: A molecular dynamics study

In this study, we investigate the dynamics of interfacial tension (IFT) between residual pore water and gas mixtures containing H2, CH4, and H2S within subsurface porous media, essential for underground hydrogen storage (UHS) systems. Utilizing molecular dynamics simulations, we established specific IFT correlations across a spectrum of H2S concentrations, ranging from 5 % to 80 %, under the conditions of 14.5 MPa and 343 K. Our results demonstrate a marked decrease in IFT, with a notable 12 % reduction observed even at a minimal H2S concentration of 5 % for H2S-H2 mixtures, contrasting with a 6 % reduction in H2S-CH4 mixtures, and reaching a saturation point at concentrations exceeding 80 %. The presence of CH4 at the interface mitigates the reduction in IFT caused by H2S, underscoring the complexity of gas interactions in subsurface storage. These insights into the molecular dynamics at the gas-water interface carry significant implications for the optimization of UHS operations, informed by the substantial variations in IFT with different H2S concentrations.

Activity responses of a mammal community to a 17-year cicada emergence event

Abstract During a limited period in the summer of 2021, 17-year cicada species (Magicicada cassini, M. septendecula, M. septendecim) represented a large pulse of easily accessible food unique to forest ecosystems in the eastern United States. Using trail cameras and acoustic recorders, we tested whether the activity levels of 8 mammal species in northwestern Indiana shifted in response to spatial and temporal variation in cicada densities from 18 May to 20 June 2021. Cicada densities varied temporally and spatially across all study sites. Most mammal species with sufficient data showed no response to cicada emergence, including 2 tree squirrel species, Peromyscus mice, Eastern Chipmunks (Tamias striatus), and 2 species of bats. Raccoons (Procyon lotor), likely cicada predators, showed a quadratic or more complex activity response to cicada abundance, indicating a potential saturation point at densities near 1 cicada per m2. Surprisingly, White-tailed Deer (Odocoileus virginianus) activity decreased to almost 0 at the same cicada densities when we expected no change in activity. While size or accessibility may exclude cicadas as prey for small and volant mammals, our results suggest predation and satiation by Raccoons. In contrast, deer may be avoiding areas of cicada abundance due to other stimuli, such as high noise output, which may decrease their ability to detect predators.

Cadmium exposure on physiological responses of Erythrophleum fordii seedlings: A comparative study

The adaptability and tolerance of native species to heavy metal-contaminated soils can provide crucial insights for the development of effective heavy metal remediation strategies. Erythrophleum fordii (E. fordii) is a native hardwood species endemic to southern China that exhibits nitrogen fixation and soil improvement capabilities. This study examined the growth and physiological responses of E. fordii seedlings to varying cadmium (Cd) concentrations (control, Cd50, Cd100, Cd150, corresponding to 0, 50, 100, and 150 ppm), aimed to ascertain its potential role in phytoremediation efforts. Current results demonstrated that a moderate concentration of Cd (Cd50) significantly enhanced several plant characteristics, including plant height, root biomass, stem biomass, net photosynthetic rate, maximum net photosynthetic rate, and light saturation point. These observed improvements ranged from 12.15 % to 32.88 %, compared with control. Conversely, the highest Cd level (Cd150) resulted in substantial reductions in plant height, root biomass, chlorophyll content, and gas exchange parameters. Furthermore, malondialdehyde content increased markedly at Cd100 and Cd150 levels by 68.86 % and 118.92 %, respectively. The activities of antioxidant enzymes (superoxide dismutase, peroxidase, and catalase) and the content of osmotic regulatory substances (soluble protein and soluble sugar) reached their peaks at Cd100 level, increased by 32.61–88.39 %. This indicated E. fordii's capacity to mitigate Cd-induced stress. Significant correlations were observed between growth indicators, chlorophyll content, and net photosynthetic rate, as well as between antioxidant enzymes and osmotic substances. The principal component analysis highlighted the superior performance of E. fordii in Cd50 treatment. The results revealed that moderate Cd promoted growth, photosynthetic activity, and physiological resilience in E. fordii, whereas the highest concentration of Cd (Cd150) was detrimental. These findings offer perceptiveness to the cultivation of E. fordii and its tolerance to heavy metals, with implications for the remediation of Cd-contaminated soils.

Flow boiling heat transfer characteristics and mechanism analysis of high-pressure water in parallel twin narrow rectangular channels

Experimental investigations on the flow boiling heat transfer characteristics of high-pressure water are carried out in parallel twin narrow rectangular channels. An integrated structure was utilized to define the geometry of the test section in this study. The cross-sectional size of a single channel measures 60 × 2 mm, with an effective heating and flow length of 1450 mm. Experiments encompass a range of pressures 10–16 MPa, mass flux 500–1500 kg m−2·s−1 and heat flux 100–300 kW m−2. First, the heat transfer characteristics in the parallel twin channels are determined. Results show the heat transfer and flow distribution between the twin channels are generally balanced, with only a slight fluctuation observed near the saturation point. Besides, for one narrow rectangular channel, the boiling heat transfer coefficient is found to be essentially affected by the system parameters. The increases in mass flux, heat flux, and pressure will all exert the promotion of boiling enhancement. Among these factors, pressure and heat flux have a relatively more pronounced impact. In addition, heat transfer mechanisms in narrow rectangular channel with a large aspect ratio under high-pressure conditions are analyzed in detail. The transverse buoyancy effect has been identified as a significant factor in the regions of single-phase forced convection and partial subcooled boiling. Once the heat transfer reaches the stage dominated by nucleate boiling, the bubble nucleation and motion behaviors constitute the primary factors of heat transfer enhancement, under the coupling effects of channel structure and high-pressure conditions.