Soluble Ratio Research Articles

A Quantitative Approach for Identifying Nitrogen Sources in Complex Yeongsan River Watershed, Republic of Korea, Based on Dual Nitrogen Isotope Ratios and Hydrological Model

Effective management of nitrate loading in complex river systems requires quantitative estimation to trace different nitrogen sources. This study aims to validate an integrated framework using soluble nitrogen isotope ratios (δ15N–NH4 and δ15N–NO3) and hydrological modeling (hydrological simulation program SPARROW) of the main stream and tributaries in the Yeongsan River to determine anthropogenic nitrogen fluxes among different land-use types in the complex river watershed. The δ15N–NH4 and δ15N–NO3 isotopic compositions varied across different land-use types (4.9 to 15.5‰ for δ15N–NH4 and −4.9 to 12.1‰ for δ15N–NO3), reflecting the different sources of nitrogen in the watershed (soil N including synthetic fertilizer N, manure N, and sewage treatment plant effluent N). We compared the soluble nitrogen isotopic compositions (δ15N–NH4 and δ15N–NO3) of the river water with various nitrogen sources (soil N, manure N, and sewage N) to assess their contribution, revealing that N from sewage treatment plant effluent as a point source was dominant during the dry season and N from forest- and soil-derived non-point sources was dominant due to intensive rainfall during the wet season. The coefficient of determination (R2) between the measured pollution load and the predicted pollution load calculated by the SPARROW model was 0.95, indicating a high correlation. In addition, the EMMA-based nitrogen contributions compared to the SPARROW-based nitrogen fluxes were similar to each other, indicating that large amounts of forest- and soil-derived N may be transported to the Yeongsan River watershed as non-point sources, along with the effect of sewage treatment plant effluent N as a point source. This study provides valuable insights for the formulation of management policies to control nitrogen inputs from point and non-point sources across different land-use types for the restoration of water quality and aquatic ecosystems in complex river systems. Given the recent escalation in human activity near aquatic environments, this framework is effective in estimating the quantitative contribution of individual anthropogenic nitrogen sources transported along riverine systems.

Tailored biodegradable films via extrusion blow molding using PBS, PBAT, and TPS

AbstractResearch to replace synthetic polymers with biodegradable polymers is on the rise because common plastics have generated serious ecosystem problems. Films with thermoplastic starch (TPS), poly(butylene succinate) (PBS), poly(butylene adipate‐co‐butylene terephthalate (PBAT), and citric acid (CA) were produced by blown extrusion. They were characterized by blow‐up ratio (BUR), water vapor permeability (WVP), soluble ratio (SR), water sorption isotherm, and thermogravimetric (TG) techniques. Films were uniform and showed BUR > 205%. The different proportions of PBS and PBAT significantly influenced the WVP of the films. All samples had WVP with an order of magnitude similar to other blends with high starch content (10−6 g m−1 day−1 Pa−1). CA efficiently decreased the WVP of the PBS/PBAT/TPS formulations (15/15/70% and 20/10/70% by mass) by 25.2% and 24.7% compared to the acid‐free formulations. There was no significant difference in SR (19.0%–20.1%). These materials were sensitive to moisture since the equilibrium moisture content increased pronouncedly from water activity of 0.5. Films showed good thermal stability, with a maximum decomposition temperature close to pure polyesters. CA did not increase the thermal stability of blends, probably because of the low content used (0.1%). Given the outcomes of this study, these films could be deemed appropriate for applications in food packaging.

Rheological Property for Nutritional Parameters Prediction of the Korla Pear

This study aimed to investigate the feasibility of predicting nutritional parameters of the Korla pear using stress relaxation and creep parameters. A creep-recovery test and stress relaxation test were performed on the pear using a TA-XT plus Texture Analyzer. Creep and stress relaxation properties of the pear were characterized by a generalized Kelvin-Voigt model (six elements) and Maxwell model (seven elements), with coefficients of determination R2 of 0.992 and 0.998, respectively. The partial rheological parameters of the two models were significantly correlated with the total soluble solid (TSS), titratable acidity (TA), and solid acid ratio (RTT) of the pear (p < 0.05). Hence, the constructed stepwise multiple linear regression models can effectively predict three nutritional parameters (correlation coefficient r of prediction model > 0.7). The RMSE value of each nutritional parameters’ prediction model based on the creep parameters was smaller than that of the prediction models based on the stress relaxation parameters. Therefore, the models constructed using creep parameters are more stable and reliable for predicting the nutritional parameters of the Korla pear.

Investigating the Correlation Between Drug Physical Properties and Physical Characteristics and Drug Entrapment Efficiencies of Chitosan-TPP Nanoparticles

Chitosan nanoparticles (NPs) have been the subject of intensive research. This study aimed to determine how different drug characteristics such as molecular weights, drug solubility in the processing medium, and drug ionization/charge state affected chitosan NPs particularly their percentage entrapment efficiency (% EE) and mean hydrodynamic diameters (MHDs). Drugs with varying molecular weights but of similar aqueous solubilities were chosen and were dissolved in a 2% chitosan-acetic acid solution. Chitosan NPs were formed using by ionic gelation technique using sodium tripolyphosphate (TPP) at specific concentration and volume ratios of chitosan to TPP. NPs containing Enalapril and Paracetamol displayed better short-term stability in terms of MHDs. A direct relationship between MHDs of NPs and chitosan concentrations was found. In comparison, at both low and high admixed drug concentrations and at high chitosan concentration, larger NPs sizes were associated with the lower molecular weight drug (Paracetamol). However, the study did not demonstrate a direct relationship between NPs characteristics such as MHDs and drugs molecular weights. The ZP of Paracetamol-loaded NPs was lowest at high drug concentrations at all chitosan concentrations compared to other drugs-loaded NPs. When compared to drugs with high and low molecular weights, medium molecular weight Atenolol showed the highest % EE. This clearly indicated that there was no direct correlation between drug molecular weight and % EE, but rather other factors influenced on % EE. Nevertheless, an inverse linear relationship with high correlation coefficients was only found when % EE was plotted against each drug molecular weight divided by the ratio of drugs solubilities in acetic acid to their employed concentrations, however the correlation was inconsistent between drugs of varying molecular weights.

Solubility of lamotrigine in age-specific biorelevant media that simulated the fasted- and fed-conditions of the gastric and intestinal environments in pediatrics and adults: implications for traditional, re-formulated, modified, and new oral formulations

BackgroundLamotrigine is an effective antiseizure medication that can be used in the management of focal and generalized epilepsies in pediatric patients. This study was conducted to quantify and compare the solubility of lamotrigine in age-specific biorelevant media that simulated the fasted and fed conditions of the gastric and intestinal environments in pediatrics and adults. Another aim was to predict how traditional, re-formulated, modified, and new oral formulations would behave in the gastric and intestinal environments across different age groups.MethodsSolubility studies of lamotrigine were conducted in 16 different age-specific biorelevant media over the pH range and temperature specified by the current biopharmaceutical classification system-based criteria. The age-specific biorelevant media simulated the environments in the stomach and proximal gastrointestinal tract in both fasted and fed conditions of adults and pediatric sub-populations. The solubility of lamotrigine was determined using a pre-validated HPLC-UV method.ResultsLamotrigine showed low solubility in the 16 age-specific biorelevant media as indicated by a dose number of > 1. There were significant age-specific variabilities in the solubility of lamotrigine in the different age-specific biorelevant media. Pediatric/adult solubility ratios of lamotrigine fell outside the 80-125% range in 6 (50.0%) and were borderline in 3 (25.0%) out of the 12 compared media. These ratios indicated that the solubility of lamotrigine showed considerable differences in 9 out of the 12 (75.0%) of the compared media.ConclusionFuture studies are still needed to generate more pediatric biopharmaceutical data to help understand the performances of oral dosage forms in pediatric sub-populations.

Modeling of the Sintered Density in Cu-Al Alloy Using Machine Learning Approaches.

In powder metallurgy materials, sintered density in Cu-Al alloy plays a critical role in detecting mechanical properties. Experimental measurement of this property is costly and time-consuming. In this study, adaptive boosting decision tree, support vector regression, k-nearest neighbors, extreme gradient boosting, and four multilayer perceptron (MLP) models tuned by resilient backpropagation, Levenberg-Marquardt (LM), scaled conjugate gradient, and Bayesian regularization were employed for predicting powder densification through sintering. Yield strength, Young's modulus, volume variation caused by the phase transformation, hardness, liquid volume, liquidus temperature, the solubility ratio among the liquid phase and the solid phase, sintered temperature, solidus temperature, sintered atmosphere, holding time, compaction pressure, particle size, and specific shape factor were regarded as the input parameters of the suggested models. The cross plot, error distribution curve, and cumulative frequency diagram as graphical tools and average percent relative error (APRE), average absolute percent relative error (AAPRE), root mean square error (RMSE), standard deviation (SD), and coefficient of correlation (R) as the statistical evaluations were utilized to estimate the models' accuracy. All of the developed models were compared with preexisting approaches, and the results exhibited that the developed models in the present work are more precise and valid than the existing ones. The designed MLP-LM model was found to be the most precise approach with AAPRE = 1.292%, APRE = -0.032%, SD = 0.020, RMSE = 0.016, and R = 0.989. Lately, outlier detection was applied performing the leverage technique to detect the suspected data points. The outlier detection discovered that few points are located out of the applicability domain of the proposed MLP-LM model.

Development of Child-Friendly Oral Formulations Containing Celecoxib: Biopharmaceutical Considerations for Formulation Scientists

Purpose: Recently, different international regulatory agencies and task forces have encouraged the pharmaceutical industry to develop child-friendly oral dosage forms. The biopharmaceutical classification system (BCS) has emerged as a tool that facilitates the development of traditional, reformulated, and novel oral dosage forms. Little research was conducted to evaluate the applicability of the BCS in developing child-friendly oral dosage forms. This study was conducted to assess the effects of age-related developmental changes in the composition and volume of gastrointestinal fluids on the solubility and performance of oral formulations containing celecoxib.
 Methods: Solubility studies were conducted at 37 ºC in the pH range of 1.2 to 6.8 in 13 different age-appropriate biorelevant media that reflected the gastric and proximal small environments in fasted and fed states for adults and pediatric populations. Quantities of celecoxib were determined using a validated HPLC method. The permeability class of celecoxib was determined using in vivo pharmacokinetic parameters, and experimental and computational molecular descriptions.
 Results: The solubility of celecoxib in the adult fed-state simulated gastric fluid was lower than that in the pediatric fed-state gastric media representative of neonates (birth to 28 days) fed soy-based formula. Similarly, the solubility of celecoxib in adult fasted-state simulated intestinal media was lower than that in the pediatric fasted-state intestinal media formulated with bile salt concentrations 50% of the adult levels. However, solubility values of celecoxib were lower in the other pediatric media compared to adult media. The age-appropriate pediatric to adult solubility ratios were outside the 80 to 125% range in 3 and was borderline in 1 out of 9 pediatric to adult solubility ratios.
 Conclusions: The solubility ratios of celecoxib exhibited significant variability in about 44.4% of the media. This indicated that significant age-related variability could be predicted for oral formulations containing celecoxib intended for pediatric use. Formulation scientists should consider the significant biopharmaceutical considerations when developing child-friendly oral formulations.

Prediction of Key Parameters in the Design of CO2 Miscible Injection via the Application of Machine Learning Algorithms

The accurate determination of key parameters, including the CO2-hydrocarbon solubility ratio (Rs), interfacial tension (IFT), and minimum miscibility pressure (MMP), is vital for the success of CO2-enhanced oil recovery (CO2-EOR) projects. This study presents a robust machine learning framework that leverages deep neural networks (MLP-Adam), support vector regression (SVR-RBF) and extreme gradient boosting (XGBoost) algorithms to obtained accurate predictions of these critical parameters. The models are developed and validated using a comprehensive database compiled from previously published studies. Additionally, an in-depth analysis of various factors influencing the Rs, IFT, and MMP is conducted to enhance our understanding of their impacts. Compared to existing correlations and alternative machine learning models, our proposed framework not only exhibits lower calculation errors but also provides enhanced insights into the relationships among the influencing factors. The performance evaluation of the models using statistical indicators revealed impressive coefficients of determination of unseen data (0.9807 for dead oil solubility, 0.9835 for live oil solubility, 0.9931 for CO2-n-Alkane interfacial tension, and 0.9648 for minimum miscibility pressure). One notable advantage of our models is their ability to predict values while accommodating a wide range of inputs swiftly and accurately beyond the limitations of common correlations. The dataset employed in our study encompasses diverse data, spanning from heptane (C7) to eicosane (C20) in the IFT dataset, and MMP values ranging from 870 psi to 5500 psi, covering the entire application range of CO2-EOR. This innovative and robust approach presents a powerful tool for predicting crucial parameters in CO2-EOR projects, delivering superior accuracy, speed, and data diversity compared to those of the existing methods.

Design of novel phenothiazine-based push-pull photoinitiators for visible light with high activity, good solubility and low migration

Using phenothiazine as electron donor group, four novel visible light photoinitiators (10-methyl-phenothiazine-2-yl) (phenyl)methanone (MPO), (10-methyl-phenothiazine-2,8-diyl) bis(phenylmethanone) (MPBO), (E)-1-(10-methyl-phenothiazine-2-yl)-3-phenylprop-2-en-1-one (MPPO) and (2E,2′E)-1,1′-(10-methyl-phenothiazine-2,8-diyl) bis(3-phenylprop-2-en-1-one) (MPBPO) with D-A structure were synthesized by one-step method. The effect of conjugated structure and CC bond on the photophysical properties, solubility and migration ratio was discussed. With the degree of conjugation and the number of CC bond increases, the maximum absorption wavelength redshifted from 385 nm (MPO) to 414 nm (MPBO) and 400 nm (MPPO) to 430 nm (MPBPO) respectively. The charge transfer between the two-component photoinitiator system (Iod as co-initiator) can significantly improve the photopolymerization efficiency, the final CC double bond conversion can reach to 80 %, and the drying time of coatings was within 5–20 s. Moreover, all MPO, MPBO, MPPO and MPBPO have good solubility in different solvents and monomers. In addition, MPO, MPBO, MPPO and MPBPO shown low migration ratio and low cytotoxicity performance.

Oil solubility effect on evaporation performance with R290 as refrigerant

The increasing awareness of the environmental impact of traditional refrigerants (such as R-404A, R-407C, R-134A, etc.) makes the demand for alternatives more urgent. Natural refrigerant propane (R-290) has a similar cooling capacity to R-22, that is attracting a great deal of attention in RAC. Toward better understanding of oil-presence effect on the evaporator performance working with R-290, the absorption behavior of R-290 in three kinds of oils (PAG 68, POE 75, PVE 68) were measured from 283.15 to 343.15 K using an isochoric saturation method. From the calculated results, the NRTL model could successfully represent the solubility of R-290/oil mixtures. Upon the experimental data, new pressure-enthalpy-vapor quality (p-h-X) diagrams were given for pure R-290 and R-290/oil blends. Isotherms of R-290/oil mixtures were divided into two regions, that is mainly related to solubility and oil circulation mass ratio. Oil-present impact on enthalpy changes in the evaporator, as well as the non-evaporation quality of R-290 at the evaporator outlet, were investigated. There is a positive correlation between enthalpy change rate and superheat, and an obviously negative correlation between enthalpy change rate and oil circulation mass fraction. Non-evaporation quality decreases with increasing superheat and increases with increasing oil circulation mass fraction.

Metrological Evaluation of the Compatibility of Two Different Digital Density Meter Adjustment Methods

Brazilian regulation requires the test methods for analysing the shrinkage factor, and the solubility ratio in crude oils must be estimated under the measurement conditions for appropriation. Since these physicochemical parameters depend upon the density, a Brazilian oil company proposed an adapted and more user-friendly methodology for adjusting the digital density meter under high pressure and temperature conditions. This study aimed to evaluate the metrological compatibility of this proposal by comparing it with the fit model presented by a manufacturer of a digital densimeter and with the tabulated reference values of fluid density. Since the density data behaviour presented non-normal distributions, the Wilcoxon signed-rank test showed metrological compatibility between the approaches studied in the pressure range from 0 psi to 1200 psi (8.273709 MPa) and the temperature range from 5 °C to 70 °C.

On Nanobubble Dynamics under an Oscillating Pressure Field during Salting-out Effects and Its DLVO Potential

We have investigated the origin, stability, and nanobubble dynamics under an oscillating pressure field followed by the salting-out effects. The higher solubility ratio (salting-out parameter) of the dissolved gases and pure solvent nucleates nanobubbles during the salting-out effect, and the oscillating pressure field enhances the nanobubble density further as solubility varies linearly with gas pressure by Henry's law. A novel method for refractive index estimation is developed to differentiate nanobubbles and nanoparticles based on the scattering intensity of light. The electromagnetic wave equations have been numerically solved and compared with the Mie scattering theory. The scattering cross-section of the nanobubbles was estimated to be smaller than the nanoparticles. The DLVO potentials of the nanobubbles predict the stable colloidal system. The zeta potential of nanobubbles varied by generating nanobubbles in different salt solutions, and it is characterized by particle tracking, dynamic light scattering, and cryo-TEM. The size of nanobubbles in salt solutions was reported to be higher than that in pure water. The novel mechanical stability model is proposed by considering both ionic cloud and electrostatic pressure at the charged interface. The ionic cloud pressure is derived by electric flux balance, and it is found to be twice the electrostatic pressure. The mechanical stability model for a single nanobubble predicts the existence of stable nanobubbles in the stability map.

Development of an Amorphous Solid Dispersion Formulation for Mitigating Mechanical Instability of Crystalline Form and Improving Bioavailability for Early Phase Clinical Studies.

In this work, an amorphous solid dispersion (ASD) formulation was systematically developed to simultaneously enhance bioavailability and mitigate the mechanical instability risk of the selected crystalline form of a development drug candidate, GDC-0334. The amorphous solubility advantage calculation was applied to understand the solubility enhancement potential by an amorphous formulation for GDC-0334, which showed 2.7 times theoretical amorphous solubility advantage. This agreed reasonably well with the experimental solubility ratio between amorphous GDC-0334 and its crystalline counterpart (∼2 times) in buffers of a wide pH range. Guided by the amorphous solubility advantage, ASD screening was then carried out, focusing on supersaturation maintenance and dissolution performance. It was found that although the type of polymer carrier did not impact ASD performance, the addition of 5% (w/w) sodium dodecyl sulfate (SDS) significantly improved the GDC-0334 ASD dissolution rate. After ASD composition screening, stability studies were conducted on selected ASD powders and their hypothetical tablet formulations. Excellent stability of the selected ASD prototypes with or without tablet excipients was observed. Subsequently, ASD tablets were prepared, followed by in vitro and in vivo evaluations. Similar to the effect of facilitating the dissolution of ASD powders, the added SDS improved the disintegration and dissolution of ASD tablets. Finally, a dog pharmacokinetic study confirmed 1.8 to 2.5-fold enhancement of exposure by the developed ASD tablet over the GDC-0334 crystalline form, consistent with the amorphous solubility advantage of GDC-0334. A workflow of developing an ASD formulation for actual pharmaceutical application was proposed according to the practice of this work, which could provide potential guidance for ASD formulation development in general for other new chemical entities.

In situ characterization of tamarind (Tamarindus indica L.) fruit and spotting sweet tamarind types in Palakkad gap of Kerala

AbstractKerala, a humid tropical southern state, is the third largest producer of Tamarind (Tamarindus indica L.) in India. This tree spice is an important livelihood option for the rural society, especially in Palakkad district which is the lead producer of tamarind in the state with a few accepted primitive cultivars, viz. ‘valanpuli’, ‘madhurapuli’ and ‘thenpuli’. A survey was conducted to identify the fruit variability and document the sweet tamarind types of Palakkad. This study revealed the variability and weight of 30 fruits was seen to be the most indicative variable of tamarind in Kerala. The pod length varied from 5.28 to 23.41 cm and fruit weight from 4.83 to 43.40 g. Hierarchical clustering on principal component analysis resulted in six clusters. The clusters I, IV and V represented collections with fruit weight more than 20 g. Box plot diagrams revealed the high real pulp value in sample KTJ 162 (9.57) and high fruit length in KTJ 44 (21.68 cm). Among 113 collections, 18 samples were collected as perceived sweet types based on local enquiry. In the scatter plot between total soluble solids and ratio between total soluble solids and total titrable acidity, two samples were spotted as sweet types with acidity below 8%. Further molecular characterization and systematic crop improvement programmes are required for conserving the eroding gene pool of tamarind in Kerala and to develop sweet types for commercial production.

Response of Growth Characteristics and Yield of Broccoli Hybrids to Foliar Spraying with Copper Nanoparticles

The field experiment was conducted during the agricultural season 2021-2022 at the research station of the Department of Horticulture and Landscaping, College of Agriculture, University of Diyala to study the effect of foliar feeding with nano and chelated copper for five broccoli hybrids. The study included two factors; The first factor is five broccoli hybrids: Jassmine (V1), 2004 (V2), Zen (V3), Matsuri (V4) and Danar (V5). The second factor has four application treatments of spraying copper: these are, zero concentration, which is spraying with distilled water only (F0), the second is chelated copper 40 mg L-1 (F2), the third is nano-copper 10 mg L-1 (F3) and the fourth is nano-copper 20 mg L-1. The experiment was performed at a split plot system and according to a randomized complete block design (RCBD). The data were collected and analysed statistically using the statistical program (SAS) and the averages were compared with Duncan’s polynomial test at the 0.05 probability level. The number of leaves, the percentage of dry matter in the leaves, the plant yield per square meter, the early appearance of the curd, the percentage of total soluble solids in the curd, and the concentration of vitamin C in the broccoli were examined. The results of the experiment showed the superiority of the Danar hybrid in the number of leaves, while the Zen hybrid was superior in the diameter of the stem and the 2004 hybrid was distinguished in the percentage of dry matter in the leaves, the early appearance of the curd, the highest yield per square meter, the best total soluble solids ratio, and the highest concentration of vitamin C in the curd. The results also showed that foliar spraying with nano-copper had a positive effect on most vegetative growth characteristics and yield, as the spraying with a concentration of 20 mg L-1 of nano-copper outperformed the percentage of dry matter in the leaves as for the number of leaves and stem diameter, the highest values were recorded in the plant yield per square meter, in the percentage of total soluble solids, and the concentration of vitamin C in the crop.

Nutritional profile and functional properties of coconut water marketed in the streets of Abidjan (Côte d'Ivoire)

Abidjan, the economic capital of Côte d'Ivoire, has several coconut water sale points in the streets. This natural beverage was very appreciated by people. Coconut waters from several varieties of coconut trees were proposed to consumers. Thus, the biochemical, nutritional, and microbiological properties of coconut water could be influenced by the variety of coconut tree. The purpose of this study was to provide the social and scientific data of coconut water sold in Abidjan streets. The study has been carried in two steps. The first step aimed to determine the knowledge level of coconut water and the reasons for consumption and the second phase regarded to analyse physicochemical, biochemical and functional properties of coconut water samples from different varieties of coconut trees. The survey through questionnaire revealed that coconut water was well known by consumers (100%) and it was consumed for its strengthen (33.33%), digestive (29.33%) and refreshing (28.34%) properties. Physicochemical, biochemical and functional properties were influenced by the variety of coconut tree. Microbiological quality of all samples in this study was not acceptable. Microbial load requires Aerobic Mesophilic Germs (AMG) to have a count of less than 5.103 UFC/mL, fewer than 10 total coliforms, and no faecal coliforms. Coconut water samples from coconut tree dwarf (CWD) were characterized by contents of fat (0.335%), titratable acidity (0.202%), total flavonoids (0.381 µg/mL QE), total phenols (0.177 µg/mL GAE), proteins (0.291%), phosphorus (0.05 mg/L) and energy value (20.21 Kcal/100 mL). The coconut water samples from coconut tree tall (CWT) were characterized by calcium (1.14 mg/L), pH (5.59), ash (0.470%), total soluble solids (5.06 °Brix), moisture (94.96%) and Calcium phosphorus ratio contents (Ca:P) (57). The coconut water samples from the streets (CWS) were characterized by contents of fiber (0.0355%), carbohydrate (4.38%), dry matter (5.09%), (total coliforms ((1.4 ± 0.4)108)CFU/mL, aerobic mesophilic germs ((4.7 ± 1.2)109)CFU/mL, antiradical activity (DPPH) (65.14±0.005%), condensed tannins (0.260±0.05 µg/mL CE) and of phosphorus (0.05 mg/L). Overall, statistical analyses showed a significant difference (P<0.05) between the samples. In sum, although coconut water is a natural beverage, it may not be appropriate for human consumption in some cases.

Nitrogen and carbon fractionation in planetary magma oceans and origin of the superchondritic C/N ratio in the bulk silicate Earth

Volatiles are important for planetary geodynamics, climate, and habitability. The C/N ratio of the bulk silicate Earth (BSE) is superchondritic, which provides a useful tool for understanding the origin of Earth's volatiles. The Earth accreted largely from differentiated planetesimals and embryos, and the fate of nitrogen and carbon in magma oceans (MOs) of such rocky bodies is key in shaping the BSE's C/N ratio. Here we present experiments performed at 0.3–3 GPa and 1400–1600°C to determine both the solubility and partitioning of nitrogen and carbon between Fe-rich metallic and silicate melts at graphite-saturation and the saturation of N2-rich gas. The quenched samples were analyzed by electron microprobe, secondary ion mass spectrometry, and Raman spectroscopy for their N–C–H–O contents and speciation. Our results show that the C/N solubility ratios of the silicate melts (ppm/ppm by wt.) are a multi-function of pressure, temperature, silicate melt composition, and mainly oxygen fugacity (fO2), and increase from 0.01 to 1.6 with increasing fO2 from IW-3.7 to IW+0.4 (IW refers to the iron–wüstite buffer). Raman spectra and theoretical considerations reveal that the main species in silicate melts are N2, N3−, and N–H in the case of nitrogen, and CO, CO2−3, and C–H in the case of carbon. Nitrogen and carbon may also form complex species, which, however, could not be identified presently. The metal/silicate partition coefficients of nitrogen and carbon DN,Cmetal/silicate are 1–114 and 34–3050, respectively. The DCmetal/silicate/DNmetal/silicate ratios are 1.5–1100, which decrease with increasing pressure, fO2, and the water content in silicate melts. Our results imply that N–C fractionation could occur during core-formation and silicate MO degassing. For a rocky body starting with a chondritic C/N ratio, core-formation would result in a superchondritic C/N ratio in its core if that rocky body is S- and Si-poor. However, a superchondritic C/N ratio can also be achieved in the silicate mantle through C-saturation coupled with preferential nitrogen degassing and loss into space, if the rocky body is oxidized and has a S-rich core, or is reduced and has a Si-rich core. Both Earth's accretion of planetesimals and embryos with cores as the major nitrogen and carbon reservoirs, and Earth's disequilibrium accretion of C-saturated embryos through core–core merging, could have helped establish the BSE's superchondritic C/N ratio. During Earth's accretion of the last few giant impactors, multiple episodes of MO degassing and erosion-induced atmospheric loss would have also favored the formation of a superchondritic C/N ratio in the BSE, due to the oxidized nature of Earth's surface MO (fO2 > IW) and the preferential loss of nitrogen into space. Finally, we emphasize that oxidization of emulsified planetesimal cores in Earth's upper mantle during its final accretion stages could have further helped establish the BSE's superchondritic C/N ratio. Accordingly, the BSE's superchondritic C/N ratio may be an outcome of combined processes operating both on the accreted planetesimals and embryos and on the proto-Earth itself.

Preparation of high-quality alkylated gasoline with low alkane-to-alkene ratio catalyzed by polyether-based Brønsted-Lewis acidic deep eutectic solvent

In this study, the solubility of isobutane in different types of polyethers was evaluated. Macroscopic and microscopic simulations of molecular bonding of isobutane to polyethers such as PEG200 and PPG200 were performed. The solubility of isobutane in different polyethers with different degrees of polymerization was investigated. The solubility of isooctane—the main alkylated gasoline product—in different polyethers was also determined. Based on the solubility ratios of isobutane and isooctane in the same polyether, PEG200 was selected as a component of a deep eutectic solvent (DES), which was then used for catalyzing the alkylation of isobutane and isobutene to prepare alkylated gasoline. Owing to the good solubility of isobutane in polyether, a three-component Brønsted–Lewis acidic DES catalyst, InCl3/PEG200/TfOH, could be used to prepare high-quality alkylated gasoline (conversion rate: 89.12%, C8 selectivity: 82.83%) at a low alkane-to-alkene ratio (5:1). Moreover, owing to its poor solubility to isooctane, the DES catalyst could be easily separated from alkylated gasoline. This DES catalyst retains its high catalytic activity over seven cycles.

Responses of soil microorganisms, enzyme activities and nutrient contents to inter-row grass ploughing and returning to the field in a natural sod culture apple orchard.

Natural sod culture in orchard is an effective measure to improve the orchard productivity and promote the sustainable production. To explore the effects of inter-row grass ploughing and returning on soil biological cha-racteristics and nutrient contents, we examined the effects of different grass returning to the field on the amount of soil microorganisms, enzyme activities and nitrogen and potassium contents of 0-20 cm soil layer. There are three treatments, cleaning tillage as the control (CK), conventional mowing management (NG), and soil ploughing annually under natural sod culture with conventional mowing condition (NGR) treatments. The results showed that soil microorganisms were dominated by bacteria, followed by actinomycetes, with the least fungi. Compared with CK, both NG and NGR treatments significantly improved the abundance of soil bacteria and fungi, with the strongest effects in NGR treatment, and significantly increased the soil urease, sucrase and catalase activities by 59.0%, 20.7%, 38.3% and 73.5%, 45.9%, 67.8%, respectively. NGR treatment significantly increased soil nitrogen and potassium contents, with the contents of ammonium nitrogen, nitrate nitrogen, particulate organic nitrogen, microbial biomass nitrogen, available potassium and water-soluble potassium being 1.5, 1.8, 1.6, 2.0, 1.3 and 1.4 times of that in CK, respectively. NGR significantly increased soluble sugar content and sugar acid ratio and subsequently improved fruit quality. Overall, NGR increased soil microbial abundance, enzyme activities, nitrogen, potassium contents and fruit quality, which could be a feasible management of inter-row grasses in the natural sod culture apple orchard.

Selection of Enzymatic Treatments for Upcycling Lentil Hulls into Ingredients Rich in Oligosaccharides and Free Phenolics

In this study, the comprehensive chemical characterization of red lentil hulls obtained from the industrial production of football and split lentils was described. The lentil hulls were rich in dietary fiber (78.43 g/100 g dry weight with an insoluble to soluble fiber ratio of 4:1) and polyphenols (49.3 mg GAE/g dry weight, of which 55% was bound phenolics), which revealed the suitability of this lentil by-product as a source of bioactive compounds with recognized antioxidant and prebiotic properties. The release of oligosaccharides and phenolic compounds was accomplished by enzymatic hydrolysis, microwave treatment and a combination of both technologies. The key role played by the selection of a suitable enzymatic preparation was highlighted to maximize the yield of bioactive compounds and the functional properties of the lentil hull hydrolysates. Out of seven commercial preparations, the one with the most potential for use in a commercial context was Pectinex® Ultra Tropical, which produced the highest yields of oligosaccharides (14 g/100 g lentil hull weight) and free phenolics (45.5 mg GAE/100 g lentil hull weight) and delivered a four-fold increase in terms of the original antioxidant activity. Finally, this enzyme was selected to analyze the effect of a microwave-assisted extraction pretreatment on the yield of enzymatic hydrolysis and the content of free phenolic compounds and oligosaccharides. The integrated microwave and enzymatic hydrolysis method, although it increased the solubilization yield of the lentil hulls (from 25% to 34%), it slightly decreased the content of oligosaccharides and proanthocyanidins and reduced the antioxidant activity. Therefore, the enzymatic hydrolysis treatment alone was more suitable for producing a lentil hull hydrolysate enriched in potential prebiotics and antioxidant compounds.