Search Results (7)

This study investigates the extraction of rhenium using trialkylbenzyl ammonium chloride (TABAC) as an alternative to trialkylamine (TAA) for recovering rhenium from highly diluted solutions. Rhenium, present as ReO₄⁻ over a wide acidity range, was extracted via an anion exchange mechanism in single-stage experiments monitored by inductively coupled plasma mass spectrometry (ICP-MS). Key variables, including pH, acid concentration, and the concentrations of extractant and metal, were examined. The results demonstrated a high extraction efficiency exceeding 99% within a pH range of 2 to 7 and from solutions containing sulfuric or hydrochloric acid at concentrations of 0.1 to 3.0 M (mol/L). However, extraction from nitric acid solutions was less efficient, with less than 30% recovery. Performance for both TAA-kerosene and TABAC-kerosene followed the order H₂SO₄ > HCl > HNO₃. The optimal TABAC concentration was 10⁻² M (mol/L) in kerosene. TABAC also showed higher selectivity than TAA, with separation coefficients Re/Mo = 66.8 and Re/W = 55.8 in 0.1–1.0 M (mol/L) sulfuric acid. Based on equilibrium studies, the complexes formed during extraction were identified as [R₃R′NH]ReO₄. This approach may offer environmentally friendly and cost-effective benefits for large-scale industrial applications, enabling efficient recovery of valuable rhenium while reducing waste and environmental impact. Full article

Time-restricted eating (TRE) is an increasingly popular dietary strategy for weight loss. Recent studies suggest that combining TRE with caloric restriction (CR) may have more favorable effects on both physical and biochemical aspects when compared with CR alone. Therefore, we performed a meta-analysis to compare the effects of TRE with CR vs. CR alone on anthropometric and biochemical measures in overweight or obese adults. We reviewed articles from PubMed, Web of science, EMBASE, and the Cochrane Library published before 25 May 2023. The meta-analysis incorporated data from seven randomized controlled trials of nine interventions, with a total of 231 participants in the TRE with CR group and 227 participants in the CR-only group. Data were analyzed using RewMan version 5.4.1. All results in our meta-analysis were described as mean difference (MD) with 95% confidence interval (Cl). Results showed that TRE with CR compared to CR alone resulted in significantly greater reductions in body weight (MD: −2.11 kg, 95% CI: −2.68 kg to −1.54 kg, p = < 0.00001, I² = 42%), body fat mass (MD: −0.75 kg, 95% CI: −1.35 kg to −0.16 kg, p = 0.01; I² = 0%), and waist circumference (MD: −1.27 cm, 95% CI: −2.36 cm to −0.19 cm, p = 0.02, I² = 0%), while no additional impact of TRE in combination with CR in comparison to CR on serum biochemical parameters were found. Our results suggest that the improvement in biochemical parameters are mainly caused by CR, while improvements in anthropometric parameters are further enhanced by TRE. Full article

Tree water transport and utilization are essential for maintaining ecosystem stability in seasonally arid areas. However, it is not clear how Platycladus orientalis absorbs, consumes via transpiration, and stores water under varying precipitation conditions. Therefore, this study used stem sap flow thermal dissipation probes and hydrogen and oxygen isotope tracing technology to observe different water control treatments in a P. orientalis plantation. We found that the average daily sap flow of P. orientalis under different water control treatments had the following order: no rainfall (NR) < half rainfall (HR) < double rainfall (DR) < natural rainfall (AR). The percentage of nocturnal sap flow was as follows: AR (13.34%) < NR (19.62%) < DR (20.84%) < HR (30.90%). The percentage of water storage was NR (4.13%) < AR (4.49%) < DR (6.75%) < HR (9.29%). The sap flow of P. orientalis was primarily affected by vapor pressure deficit and solar radiation, with a degree of influence of DR < NR < HR < AR. The response of P. orientalis sap flow to environmental factors differed due to the soil changes in relative extractable water (REW) before and after precipitation. During high REW conditions, environmental factors have a higher impact on sap flow. The source of water absorbed changed regularly with the precipitation gradient. When soil water content increased, the water source used by P. orientalis gradually changed to shallow soil. Compared to before and after precipitation, there was no significant change except for NR. P. orientalis could regularly adjust the activities of transpiration water consumption, water storage, and absorption. This adaptive property is conducive to survival through extreme drought stress. Full article

The combined effects of surface rotation and using binary nanoparticles on the phase change process in a 3D complex-shaped vented cavity with ventilation ports were studied during nanofluid convection. The geometry was a double T-shaped rotating vented cavity, while hybrid nanofluid contained binary Ag–MgO nano-sized particles. One of the novelties of the study was that a vented cavity was first used with the phase change–packed bed (PC–PB) system during nanofluid convection. The PC–PB system contained a spherical-shaped, encapsulated PCM paraffin wax. The Galerkin weighted residual finite element method was used as the solution method. The computations were carried out for varying values of the Reynolds numbers ($100\le \mathrm{Re}\le 500$), rotational Reynolds numbers ($100\le \mathrm{Rew}\le 500$), size of the ports ($0.1L1\le di\le 0.5L1$), length of the PC–PB system ($0.4L1\le L0\le L1$), and location of the PC–PB ($0\le yp\le 0.25H$). In the heat transfer fluid, the nanoparticle solid volume fraction amount was taken between 0 and $0.02\%$. When the fluid stream (Re) and surface rotational speed increased, the phase change process became fast. Effects of surface rotation became effective for lower values of Re while at Re = 100 and Re = 500; full phase transition time (tp) was reduced by about 39.8% and 24.5%. The port size and nanoparticle addition in the base fluid had positive impacts on the phase transition, while 34.8% reduction in tp was obtained at the largest port size, though this amount was only 9.5%, with the highest nanoparticle volume fraction. The length and vertical location of the PC–PB system have impacts on the phase transition dynamics. The reduction and increment amount in the value of tp with varying location and length of the PC–PB zone became 20% and 58%. As convection in cavities with ventilation ports are relevant in many thermal energy systems, the outcomes of this study will be helpful for the initial design and optimization of many PCM-embedded systems encountered in solar power, thermal management, refrigeration, and many other systems. Full article

Risk-taking is part of the multidimensional nature of impulsivity, consisting of an active engagement in behaviors or choices with potentially undesirable results, with probability as the cost for an expected reward. In order to understand the neurophysiological activity during risky behavior and its relationship with other dimensions of impulsivity, we have acquired event-related-potential (ERP) data and self-reported impulsivity scores from 17 non-clinical volunteers. They underwent high-resolution electroencephalography (HR-EEG) combined with an adapted version of the Balloon Analogue Risk Task (BART), and completed the Barratt Impulsiveness Scale (BIS-10) and the Urgency, Premeditation, Perseverance, Sensation Seeking, Impulsive Behavior Scale (UPPS). The ERP components were sensitive to valence (FRN, P300) and risk/reward magnitude (SPN, RewP). Our main finding evidenced a positive correlation between the amplitude of the P300 component following positive feedback and both the global UPPS score and the (lack of) perseverance UPPS subscale, significant for several adjacent electrodes. This finding might suggest an adaptive form of impulsive behavior, which could be associated to the reduction on the difference of the P300 amplitude following negative and positive feedback. However, further investigation with both larger clinical and non-clinical samples is required. Full article

The reward system has been implicated as a potential neural mechanism underlying social-communication deficits in individuals with autism spectrum disorder (ASD). However, it remains unclear whether the neural reward system in ASD is sensitive to behavioral interventions. The current study measured the reward positivity (RewP) in response to social and nonsocial stimuli in seven adolescents with ASD before and after participation in the Program for the Education and Enrichment of Relational Skills (PEERS^®) intervention. This study also included seven neurotypical adolescents who were tested at two time points but did not receive intervention. We examined the RewP across the course of a task by comparing brain activity during the first versus second half of trials to understand patterns of responsivity over time. Improvements in social skills and decreased social-communication impairments for teens with ASD were observed after PEERS^®. Event-related potential (ERP) results suggested increased reward sensitivity during the first half of trials in the ASD group after intervention. Adolescents with ASD who exhibited less reward-related brain activity before intervention demonstrated the greatest behavioral benefits from the intervention. These findings have implications for how neuroscience can be used as an objective outcome measure before and after intervention in ASD. Full article

This paper analyses the recent recurring dieback and growth decline of Black pine (P. nigra Arn. var austriaca) in the Keszthely mountains of south-west Hungary, and their relations to water deficits due to droughts. These relations were studied in five stands with low soil water storage capacity for the period 1981–2016. The vitality was assessed using 60 tree-ring samples and changes in remotely sensed vegetation activity indices, i.e., the normalized difference vegetation index (NDVI) and the normalized difference infrared index (NDII). Water deficit was estimated by using meteorological drought indices such the standardized precipitation–evapotranspiration index (SPEI) and the forestry aridity index (FAI), as well as the relative extractable water (REW), calculated by the Brook90 hydrological model. Results revealed a strong dependency of annual tree ring width on the amount of water deficit as measured by all the above estimators, with the highest correlation shown by the summer REW. Droughts also showed a long-term superimposed effect on tree growth. NDII seemed to be more sensitive to drought conditions than NDVI. The robust dependency of tree growth on the summer water availability combined with the projected increasing aridity might lead to decreasing growth of Black pine in Hungary towards the end of the century. We thus argue that the suggestion by several papers that Black pine can be a possible substitute species in the Alpine and Mediterranean region in the future should be revisited. Full article