Oil Fractions Research Articles

A critical review on Pulicaria species occurring in Qatar: traditional uses, phytochemistry and biological activities

AbstractIn Qatar, three main species of Pulicaria (from Asteraceae) such as Pulicaria undulata (L.) C.A.Mey, Pulicaria gnaphalodes (Vent.) Boiss. and Pulicaria sicula (L.) Moris are reported. Traditionally, these species have almost the same ethnomedical uses, including their use as herbal tea. This could be because of morphological similarities among some of these species, which also results in taxonomic ambiguity. Altogether, this indicates that these species need to be reviewed comparatively, to understand the phytochemical uniqueness and therapeutic significance of each species individually, including species differentiation at the subspecies level. Hence, this review aims to comparatively review the available literature about traditional uses, phytochemistry, and bio-activities of these species. Being aromatic plants, the chemical composition of essential oils of these species has been extensively studied and reported over 300 volatile organic compounds. Among these, oxygenated monoterpenes and sesquiterpenes are dominant. The diverse and distinguishable composition of essential oils can differentiate P. undulata and Pulicaria crispa (Forssk.) Oliv. (Synonyme: Pulicaria undulata subsp. undulata). Likewise, flavonoids and sesquiterpenes are the most reported classes of compounds in non-essential oil fractions. Various biological and pharmacological activities are reported to the essential oils, crude extracts, and their fractions, or isolated compounds of these species. Among these, antimicrobial, anticancer, and anti-oxidant activities were mostly investigated, mainly under in vitro conditions. Several distinguishable compounds are listed for each species that can potentially be used as chemical markers while characterizing these species. Most of the traditional claims of these species are validated in recent scientific studies. However, further detailed in vivo clinical interventions are needed for their potential use as therapeutic agents.

Nutrient supplementation changes chemical composition of soil organic matter density fractions in desert steppe soil in northern China

The influence of reactive nitrogen (N) and phosphorus (P) supplementation on ecosystem dynamics of soil organic matter (SOM) shows extensive variations. The underlying mechanisms of regulation of the chemical composition and dynamics of different SOM density fractions (DFs) in aggregates in a desert steppe by N and P supplementation are unclear. Here, the chemical composition and organic carbon (C) and N dynamics of various SOM DFs under N and P addition were assessed. Surface soil samples taken at 0–10 cm depth were obtained from 4-year (2017–2021) experiments under four conditions, namely N treatment, P treatment, combined N and P treatment (NP), and no nutrient supplementation (CK), in a desert steppe located in northern China. Nutrient supplementation significantly increased (P < 0.05) SOM content by 8.89–35.4%; however, the total N content remained constant. N addition mainly increased SOM content in the macroaggregates (>0.25 mm), while P enhanced SOM in microaggregates (0.25–0.053 mm) and silt-clay (<0.053 mm). The fine particulate organic matter (fPOM) proportion was increased significantly (P < 0.05) by 18.4% and 16.4% in macro- and microaggregates under N addition, respectively; P addition mainly enhanced mineral-associated SOM (mSOM) proportion in aggregates. N supplementation remarkably enhanced (P < 0.05) fPOM’s organic C content by 27.3% and 32.0%, and N content by 40.9% and 145.7% in macro- and microaggregates, respectively. Single N and P addition promoted the enrichment of labile and resistant organic components in light fraction (LF), respectively. N promoted the enrichment of stable organic components in the mSOM of microaggregates. Nutrient inputs drive mSOM formation through the interaction of carboxyl-C and mineral surface. Based on a stronger δ13C and δ15N signal, N addition enhanced SOM decomposition in aggregates. Nutrient supplementation promoted SOM accumulation through the formation of more stable old C in POM and silt-clay. Our findings suggest that SOM accumulation in desert steppe probably increases following nutrient addition, but the mechanism is different through which N or P enrichment affects soil dynamics and chemical composition of SOM DFs in desert steppe.

Oil emulsion stability in electrolyzed water solutions

Metastable electrochemically-activated water solutions possess unique properties that make it possible to modify food emulsions. This comparative analysis featured the stability of model oil-in-water emulsions with anolyte or catholyte as a dispersion medium, as well as the physical and morphometric profile of the emulsion system. The research involved emulsions based on anolyte and catholyte. They consisted of refined sunflower oil, emulsifier (lecithin), and stabilizers, which were represented by sodium alginate, sodium carboxymethylcellulose, pectins, and agar. The study also covered such parameters as aggregative stability, viscosity, morphometry, oil particle size, and zeta potential. Anolyte and catholyte affected the process of separation in the model emulsions. The samples stabilized with alginate and sodium carboxymethylcellulose proved to be the most stable emulsions while agar triggered gelation. The effect of substituting tap water with metastable electrolyzed water solutions depended on the oil proportion in the emulsion. Catholyte destabilized the samples with 20% of oil and liquified gel in the samples stabilized with agar. Anolyte was more aggressive in destabilizing emulsions with 30% of oil. The effective viscosity of these emulsions correlated with the stable phase fraction. The anolytebased samples had low effective viscosity. The opposite results for emulsions with different oil fractions may have been caused by interface changes, i.e., surface tension, adsorption, coalescence, etc. In the emulsions with 46% of oil and animal origin emulsifier, neither anolyte nor catholyte had any significant effect on the aggregative stability of the system. The revealed patterns can be used to control the properties of emulsion products with oil phase ≤ 30%, e.g., low-fat mayonnaises, sauces, emulsion drinks, etc. Metastable electrolyzed water solutions may provide a reagent-free control of properties and patterns of finished or semi-finished foods and biological raw materials.

Crop area change in the context of civil war in Tigray, Ethiopia

Abstract Smallholder, rain-fed agriculture has been practiced in Tigray, Ethiopia for thousands of years, so farmers have experience with natural disturbances. However, civil war began in November 2020 and disrupted the agricultural system through theft and destruction of farming implements, livestock, and crops, and threats towards human activity, impacting farmers’ ability to work their land. To investigate effects on agricultural activity we used remote sensing data and machine learning methods to map cropped area across Tigray from 2017 to 2022. Specifically, spectral mixture analysis was applied to Sentinel-2 data to produce green vegetation, non-photosynthetic vegetation, soil, and shade endmember fractions. Monthly medians of these fractions, along with reference data generated by manual interpretation of very high spatial resolution data, were used to drive random forests-based classifications of crop/no-crop for each year. Initially we used a greenness threshold to distinguish between active and abandoned fields for a given year, but when rainfall is adequate, fields abandoned due to conflict can green up with weeds rather than crops, leading to false positive crop detections. In the spring, abandoned fields have a bright soil crust due to a lack of plowing, so these fields were removed from the crop reference data if the March soil endmember fraction anomaly was greater than 0.15. Overall accuracies of the crop/no-crop maps ranged from 80% to 90% for the different districts. Producer’s/user’s accuracies for the crop class ranged from 55%–80%/69%–90%. In 2021, crop area declined by 29% and 20% in West and Northwest Tigray, respectively, corresponding with reports of intense conflict there. The rest of Tigray showed a mix of smaller increases and decreases, indicating more resilience to the regional conflict. Finally, in 2022 we found increases in cropped area relative to 2021, for all districts except West Tigray, indicating recovery except for the areas where conflict was most severe.

Optimizing invasive plant biomass valorization: Deep eutectic solvents pre-treatment coupled with ZSM-5 catalyzed fast pyrolysis for superior bio-oil quality

The primary objective of this study is to explore the application of a deep eutectic solvent, synthesized from lactic acid and choline chloride, in combination with a pre-treatment involving ZSM-5 catalytic fast pyrolysis, aimed at upgrading the quality of bio-oil. Characterization results demonstrate a reduction in lignin content post-treatment, alongside a significant decrease in carboxyls and carbonyls, leading to an increase in the C/O ratio and noticeable enhancement in crystallinity. During catalytic fast pyrolysis experiments, the pre-treatment facilitates the production of oil fractions, achieving yields of 54.53% for total hydrocarbons and 39.99% for aromatics hydrocarbons under optimized conditions. These findings validate the positive influence of the deep eutectic solvent pre-treatment combined with ZSM-5 catalytic fast pyrolysis on the efficient production of bio-oil and high-value chemical derivatives..

Fractionation of metals in soil for strawberry cultivation: Effect on metal migration in food chain and application in risk assessment

Although trace metals in strawberry production system have attracted growing attention, little is known about metal fractionation in soil for strawberry cultivation. We hypothesized that the metal fractions in soil influenced by strawberry production had significant effect on food chain transport of metals and their risk in soil. Here, samples of strawberries and soil were gathered in the Yangtze River Delta, China to verify the hypothesis. Results showed that the acid-soluble Cr, Cd, and Ni in soil for strawberry cultivation were 21.5%–88.3% higher than those in open field soil, which enhanced uptake and bioaccessible levels of these metals in strawberries. Overall, the ecological, mobility, and health risks of Pb, Zn, Ni, and Cu in soil were at a low level. However, the ecological risk of bioavailable Cd, mobility risk of Cd, and cancer risk of bioavailable Cr in over 70% of the soil samples were at moderate, high, and acceptable levels, respectively. Since the increased acid-soluble Cr and Ni in soil were related to soil acidification induced by strawberry production, nitrogen fertilizer application should be optimized to prevent soil acidification and reduce transfer of Cr and Ni. Additionally, as Cd and organic matter accumulated in soil, the acid-soluble Cd and the ecological and mobility risks of Cd in soil were enhanced. To decrease transfer and risk of Cd in soil, organic fertilizer application should be optimized to mitigate Cd accumulation, alter organic matter composition, and subsequently promote the transformation of bioavailable Cd into residual Cd in soil.

Application of Luminescent Effects In CdSe/CdS/ZnS Quantum Dots for the Determination of Sulphur-Containing Impurities in Mixtures of Hydrocarbons and Oils

The article is dedicated to the development of a new method for the sulphur-containing compound impurities analysis in mixtures of liquid hydrocarbons and corresponding oil fractions, based on the quenching of CdSe/CdS/ZnS quantum dots photoluminescence effect. The control of quantitative content of such impurities in oil samples is very important for the organization of the processes of its further processing and subsequent wide practical application. The work uses specially developed methods for the synthesis of CdSe/CDs/ZnS quantum dots, containing a semiconductor core, coated with a composite shell consisting of semiconductor and dielectric layers, as well as a fluorinated polymer porous layer. This technique made it possible to achieve a high quantum yield of photoluminescence (80–90) %, high temporal stability of luminescence in the range of (580–650) nm, as well as good compatibility of quantum dots with liquid hydrocarbon media. For the analysis, a special luminescent sensor was manufactured, which allows measuring the presence of organic sulphur-containing impurities with high sensitivity: (10–5 – 10–4) mg/kg. The technique is low-cost, allows the use of compact equipment and can be used to conduct operational analysis in real time.

Исследование условий теплового самовозгорания тяжелых углеводородов (на примере битумов) на развитой поверхности волокнистой негорючей теплоизоляции

Experimental and analytical studies of thermal spontaneous combustion of substances of heavy oil fraction distilling (fuel oil, bitumen, tar) when contacting with a developed surface of non-flammable fibrous (such as slag and glass wool, fiberglass) material of thermal insulation of a tank have been conducted based on the example of bitumen. Experimental studies and calculations have shown that on the developed surface of fibrous materials impregnated with bitumen, the process of bitumen decomposition involving the generation of thermal and thermal-oxidative degradation products of heavy hydrocarbons able to auto-ignite (ignite spontaneously on the developed non-flammable fibrous surface) or ignite in case of availability of ignition source is possible under certain conditions at relatively low temperatures (~120 °С and lower), i.e., at temperatures close to the maximum process temperature (~180 °С) and significantly lower temperatures compared to the temperature of spontaneous ignition of bitumen (~330–380 °С). The calculations of thermal flows have shown how (via what methods) the thermal conductivity of thermal insulation impregnated with bitumen can be improved and, thereby, the probability of its spontaneous combustion can be reduced or prevented. Based on experimental and analytical studies and calculations, the proposals for preventing spontaneous combustion of thermal insulation materials of storage tanks for bitumen and other hydrocarbons of high distillation of petroleum products have been formulated.

Research on the Transformation Mechanism of Soil Cadmium Fractions under the Conditions of Freeze-thaw and Crude Oil Contamination in Wetlands in the Songnen Plain, China

Environmental changes can significantly affect heavy metals behave in soil. Currently, we know little about the impact of crude oil contamination on heavy metal fractions in soil, with few studies available on heavy metal fraction transformation under the composite action of freeze-thaw and crude oil contamination. In this study, soil samples were collected from the Momoge Wetland in the Songnen Plain. Properties including pH, cation exchange capacity, calcium carbonate, free iron oxide, dissolved organic carbon, microbial biomass carbon, and cadmium (Cd) fractions under freeze-thaw, crude oil contamination, and the two combined (composite action) were analysed. The results show that under freeze-thaw, crude oil contamination, and composite action, soil properties changed significantly; soil water-soluble Cd content significantly increased by 54.17%, 62.50%, and 33.33% from control levels, respectively; soil ion-exchangeable Cd content decreased significantly by 10.90%, 23.73%, and 18.64% from control levels, respectively; soil residual Cd content significantly increased by 80.36%, 94.64%, and 132.14% from control levels, respectively; carbonate-bound, humic acid-bound, Fe-Mn oxide-bound, and strongly organic-bound Cd did not change significantly. Soil dissolved organic carbon, pH, CaCO3, and free iron oxide were significantly correlated with water-soluble, ion-exchangeable, carbonate-bound, and Fe-Mn oxide-bound Cd, respectively. This study provides a theoretical basis for evaluating soil Cd behaves in crude oil contaminated wetlands in cold regions.

Modifying the gas-oil ratio and water cut of a PVT lookup table using correlations for fluid volatility

PVT lookup tables with fixed fluid composition are widely used by simulation software packages to model complex multiphase flow in petroleum production systems. These tables contain pre-calculated values of various fluid properties, including phase fractions, densities, viscosities, and other properties that are relevant to fluid behaviour. The pre-calculated values are based on a given set of pressures, temperatures, and composition. The tables enable efficient and accurate simulations by reducing computational load. However, they are created for fluids with fixed total composition, which limits their use for modelling fluids with varying gas-oil ratios and water cuts.To address this limitation, this work introduces a novel methodology for adjusting the gas-oil ratio and water cut within a given PVT table without changing the composition of the fluid. The methodology relies on correlations developed for volatility, estimating bubble- and dewpoint pressures when adjusting gas-oil ratio and water cut. The model demonstrates remarkable efficacy, achieving excellent agreement with bubble- and dewpoint pressures, yielding average absolute relative errors of only 0.85% and 0.68% respectively for gas-oil ratio adjustments, and 0.97% for water cut adjustments. It is further demonstrated that the new model accurately predicts phase fractions of typical volatile oils below the critical temperature and black oils when adjusting the gas-oil ratio and water cut. Additionally, the model can provide rough estimates for volatile oils above the critical temperature and for gas condensates. Moreover, model reliability is expected if the gas-oil ratio and water cut adjustments are kept within a range of 20–180% of the original values.The work provides a valuable approach to improve the flexibility of fixed composition PVT lookup tables for simulating multiphase production systems.

Partitioning and Mobility of Chromium in Iron-Rich Laterites from an Optimized Sequential Extraction Procedure.

Chromium (Cr) leached from iron (Fe) (oxyhydr)oxide-rich tropical laterites can substantially impact downstream groundwater, ecosystems, and human health. However, its partitioning into mineral hosts, its binding, oxidation state, and potential release are poorly defined. This is in part due to the current lack of well-designed and validated Cr-specific sequential extraction procedures (SEPs) for laterites. To fill this gap, we have (i) first optimized a Cr SEP for Fe (oxyhydr)oxide-rich laterites using synthetic and natural Cr-bearing minerals and laterite references, (ii) used a complementary suite of techniques and critically evaluated existing non-laterite and non-Cr-optimized SEPs, compared to our optimized SEP, and (iii) confirmed the efficiency of our new SEP through analyses of laterites from the Philippines. Our results show that other SEPs inadequately leach Cr host phases and underestimate the Cr fractions. Our SEP recovered up to seven times higher Cr contents because it (a) more efficiently dissolves metal-substituted Fe phases, (b) quantitatively extracts adsorbed Cr, and (c) prevents overestimation of organic Cr in laterites. With this new SEP, we can estimate the mineral-specific Cr fractionation in Fe-rich tropical soils more quantitatively and thus improve our knowledge of the potential environmental impacts of Cr from lateritic areas.

Effects of biochar immobilization of Serratia sp. F4 OR414381 on bioremediation of petroleum contamination and bacterial community composition in loess soil

Petroleum hydrocarbons pose a significant threat to human health and the environment. Biochar has increasingly been utilized for soil remediation. This study investigated the potential of biochar immobilization using Serratia sp. F4 OR414381 for the remediation of petroleum-contaminated soil through a pot experiment conducted over 90 days. The treatments in this study, denoted as IMs (maize straw biochar-immobilized Serratia sp. F4), degraded 82.5% of the total petroleum hydrocarbons (TPH), 59.23% of the aromatic, and 90.1% of the saturated hydrocarbon fractions in the loess soils. During remediation, the soil pH values decreased from 8.76 to 7.33, and the oxidation-reduction potential (ORP) increased from 156 to 229 mV. The treatment-maintained soil nutrients of the IMs were 138.94 mg/kg of NO3- -N and 92.47 mg/kg of available phosphorus (AP), as well as 11.29% of moisture content. The activities of soil dehydrogenase (SDHA) and catalase (CAT) respectively increased by 14% and 15 times compared to the CK treatment. Three key petroleum hydrocarbon degradation genes, including CYP450, AJ025, and xylX were upregulated following IMs treatment. Microbial community analysis revealed that a substantial microbial population of 1.01E+ 09 cells/g soil and oil-degrading bacteria such as Salinimicrobium, Saccharibacteria_genera_incertae_sedis, and Brevundimonas were the dominant genera in IMs treatment. This suggests that the biochar immobilized on Serratia sp. F4 OR414381 improves soil physicochemical properties and enhances interactions among microbial populations, presenting a promising and environmentally friendly approach for the stable and efficient remediation of petroleum-contaminated loess soil.

Catalytic Pyrolysis of Naomaohu Coal Using Combined CaO and Ni/Olivine Catalysts for Simultaneously Improving the Tar and Gas Quality

Catalytic pyrolysis of low-rank coal is currently an effective method for producing high-quality tar and gas. In this study, catalytic upgrading of volatiles from Naomaohu (NMH) coal pyrolysis has been conducted in a two-stage fixed-bed reactor using combined CaO and Ni/olivine (Ni-loaded olivine) catalysts. The effect of catalyst distribution modes and catalytic temperature on the tar and gas quality has been investigated. Simulated distillation and GC-MS analysis have been used to investigate the distribution of tar components. The results indicated that the light oil fraction in tar dramatically increased due to the combination of CaO and Ni/olivine. The CaO-Ni/olivine mode is especially better compared to the layouts of the Ni/olivine-CaO mode and the mixed mode. The CaO-Ni/olivine mode ensures a higher light fraction in tar at 69.3% and a light oil fraction at 29.8% at a catalytic temperature of 450 °C, while the heavy tar fraction decreased to 30.7%. Meanwhile, the contents of benzene (heteroatomic substituents) in tar significantly increased from 2.55% to 6.45% compared with the blank test. In this scenario, CaO breaks down macromolecular compounds in tar and cleaves long-chain esters to produce aliphatic hydrocarbons. These hydrocarbons are then dehydrogenated to produce lighter aromatic hydrocarbons over the CaO surface. Subsequently, the volatiles pass through the Ni/olivine catalysis, where ether compounds are produced by means of dehydration reactions. In addition, the CaO absorbs the CO2 in the pyrolysis gas, leading to an elevation of CH4 and H2 concentration. Particularly, the concentration of H2 significantly increased from 16.2% to 30.37%, while the concentration of CO2 significantly decreased from 37.9% to 10.57%. These findings suggest that the usage of combined CaO and Ni/olivine catalysts is beneficial for improving both the tar and gas quality.

Thin-film composite membranes with contorted monomer for high-flux isothermal refining

The development of isothermal refining processes is important because of the high energy demands of crude oil separation. Membrane technology provides separation efficiency and low carbon footprint. This efficiency can be fine-tuned and enhanced by modifying the chemistry of the membrane selective layer. Herein, we describe the fabrication of membranes by interfacial polymerization using a combination of contorted fluorinated monomer bearing six fluorine atoms and trimesoyl chloride in the organic phase. A fluorinated m-phenylene diamine was added to the aqueous phase. This approach produces membranes with high surface roughness, increases their hydrophobicity and promotes the transport of hydrocarbons with high selectivity and toluene permeance (15.6 L m−2 h−1 bar−1). Successful evaluations were conducted for the fractionation of crude oil, confirming the potential for application in the petrochemical industry.

Bioremediation of Oil-Contaminated Soils of the Zhanazhol Deposit from West Kazakhstan by Pseudomonas mendocina H-3

The culture of Pseudomonas mendocina H-3 was selected as the microorganism for oil destruction, and its effect on oil-contaminated soil from the Zhanazhol deposit in West Kazakhstan was studied. After conducting model laboratory experiments, field experiments were carried out. Six and twelve months after the treatment of the oil-contaminated field with microorganisms, the amount of oil fractions in the soil decreased noticeably, while the content of asphaltenes remained constant. Analyses show that the composition of the oil fraction changes—the concentration of paraffin-naphthenic—polycycloaromatic components decreases, whereas the relative amount of mono- and bicycloaromatic hydrocarbons increases. The results of the efficiency assessment showed that the use of Pseudomonas mendocina H-3 cell suspension in natural conditions leads to a decrease in the content of hydrocarbons in the soil from 55 to 70%. The lower efficiency of bioremediation with cell cultures in field experiments (on average, 61%) compared with laboratory model studies (reduction of oil content to 79%) is apparently associated with climatic conditions.

Comparison of Antioxidants to Increase the Oxidation Stability of Pyrolysis Oils of Three Plastics Using Iodine Value

Pyrolysis is an excellent method for recovering mixed and contaminated plastics that are no longer recyclable. Special attention must be paid to the stability of the fuel to avoid the formation of undesirable products. This can be achieved by additives such as antioxidants. In this study, high-density polyethylene, polypropylene, and polystyrene plastic waste are slowly pyrolyzed to a maximum of 470 degrees Celsius. A gasoline fraction (0–190 °C) and a diesel fraction (190–320 °C) are then obtained from these. Three antioxidants are added to these fractions: pyrocatechol, phenol, and freshly produced algal pyrolysis oil; the latter is described in the literature as containing particularly high levels of antioxidants. The oxidation stability of these mixtures and the change in the iodine number over time are measured using a newer method than the commonly used method of Wijs. Phenol improves the oxidation stability best, followed successively by algae pyrolysis oil and pyrocatechol. The oxidation stability of the gasoline fraction of the polypropylene pyrolysis oil with phenol is 49% higher than that of the same fraction without antioxidants.

Nitrogen addition enhances nitrogen but not carbon mineralization in aggregate size fractions of soils in a Pinus massonia plantation

IntroductionAtmospheric nitrogen (N) deposition can impact the levels of soil organic carbon (SOC) and total nitrogen (total N) by altering the soil N availability. However, the effect of N input on the mineralization of SOC and total N in various soil aggregate size fractions requires further clarification.MethodsThe soil samples were collected from a Pinus massoniana plantation situated in the Three Gorges Reservoir Area of China. Over a period of three years, the soils from the plantation were subjected to four different levels of nitrogen addition (0 [N0], 30 [N30], 60 [N60], and 90 [N90] kg N ha−1 yr−1). The impact of N addition on the mineralization of SOC and total N in aggregates was evaluated through an incubation experiment, encompassing four aggregate sizes (2000 − 8000, 1000 − 2000, 250 − 1000, and &amp;lt; 250 μm).ResultsThe &amp;lt; 250 μm fraction showed the highest levels of cumulative C mineralization, while the lowest levels were observed in the 2000 − 8000 μm fraction. Compared to the &amp;lt; 250 um fraction, a drop of 9 − 21% in cumulative C mineralization was observed in the 2000 − 8000 μm fraction, indicating that soil aggregates enhance the stability of C in the soil. Cumulative N mineralization levels were consistently at their lowest in the 2000 − 8000 μm fraction, indicating aggregates reducing mineralization-related N loss. Adding N to forest soil samples led to a reduction in cumulative C mineralization. In contrast, an opposite trend was observed in the cumulative N mineralization after adding N in microaggregates. Nitrification was the main contributor to net N mineralization. SOC and total levels increased in response to N30 and N60. N addition leads to an increase in the weight ratio of the 1000 − 2000 μm fraction. Moreover, N90 was linked to decreases in microbial biomass C and N.DiscussionThese findings confirm that the structural characteristics of soil aggregates play a crucial role in sequestering organic carbon and total N sequestration in the presence of N deposition, while highlighting N loss from the soil caused by N input.

Stabilization of Pickering emulsions by oxidized starch/zein nanoparticle complexes

In this study, oxidized starch (OS)/zein nanoparticles (ZNP) complexes were prepared and used to stabilize Pickering emulsions. The effect of starch oxidation using three levels of sodium hypochlorite (2.0%, 3.0%, 4.0% active chlorine, dry basis) on the properties of OS/ZNP complexes and complex-stabilized Pickering emulsions were evaluated. The interaction between oxidized starch and zein nanoparticles was confirmed by X-ray diffractometry (XRD) and Fourier transform infrared (FT-IR) spectrometry. The presence of oxidized starch improved the wettability of OS/ZNP complexes. The optimum contact angle (θ) of OS/ZNP complexes was 90.88°, when starch was oxidized with 3.0% active chlorine (3.0% OS). The appearance, micromorphology and oil droplet-size distribution suggested that OS/ZNP complex-stabilized Pickering emulsions were formed. Rheological measurements indicated that Pickering emulsions showed shear-thinning behavior. Furthermore, the viscoelasticity of Pickering emulsions was dependent on the oxidized starch and oil fractions. Stability test showed that the stability of Pickering emulsion can be improved by increasing the oil fraction from 20% to 50%, and Pickering emulsion stabilized by 3.0% OS/ZNP complexes had the highest stability. This work provides information on OS/ZNP complex-stabilized Pickering emulsions.

Oil spill risk analysis for the NEOM shoreline

A risk analysis is conducted considering an array of release sources located around the NEOM shoreline. The sources are selected close to the coast and in neighboring regions of high marine traffic. The evolution of oil spills released by these sources is simulated using the MOHID model, driven by validated, high-resolution met-ocean fields of the Red Sea. For each source, simulations are conducted over a 4-week period, starting from first, tenth and twentieth days of each month, covering five consecutive years. A total of 180 simulations are thus conducted for each source location, adequately reflecting the variability of met-ocean conditions in the region. The risk associated with each source is described in terms of amount of oil beached, and by the time required for the spilled oil to reach the NEOM coast, extending from the Gulf of Aqaba in the North to Duba in the South. To further characterize the impact of individual sources, a finer analysis is performed by segmenting the NEOM shoreline, based on important coastal development and installation sites. For each subregion, source and release event considered, a histogram of the amount of volume beached is generated, also classifying individual events in terms of the corresponding arrival times. In addition, for each subregion considered, an inverse analysis is conducted to identify regions of dependence of the cumulative risk, estimated using the collection of all sources and events considered. The transport of oil around the NEOM shorelines is promoted by chaotic circulations and northwest winds in summer, and a dominant cyclonic eddy in winter. Hence, spills originating from release sources located close to the NEOM shorelines are characterized by large monthly variations in arrival times, ranging from less than a week to more than 2 weeks. Similarly, large variations in the volume fraction of beached oil, ranging from less then 50% to more than 80% are reported. The results of this study provide key information regarding the location of dominant oil spill risk sources, the severity of the potential release events, as well as the time frames within which mitigation actions may need to deployed.

Chemical Composition and Bioactivity of Dill Seed (Anethum graveolens L.) Essential Oil from Plants Grown under Shading

This study determined the content and composition of dill seed (Anethum graveolens L.) essential oil under varying light conditions: non-shaded plants in open fields and plants covered with pearl shade nets (40% shade index). Essential oil was extracted using Clevenger hydrodistillation. The essential oil content was 4.63% for non-shaded plants and 4.81% for shaded plants. GC/MS analysis revealed twenty-one and twenty-two components in dill seed from non-shaded and shaded plants, respectively. The terpenic fraction of essential oil from non-shaded plants consisted mainly of oxygen-containing monoterpene derivatives (53.6%), with carvone (46.1%) as the primary component, followed by monoterpene hydrocarbons (46.4%), predominantly limonene (43.8%). Essential oil from shaded plants contained a higher content of carvone (49.8%) and a lower content of limonene (37.8%) compared to essential oil from non-shaded plants. Non-shaded plant essential oil exhibited stronger antioxidant activity (EC50 value: 26.04 mg mL−1) than shaded plant essential oil (54.23 mg mL−1). Dill seed essential oil showed the most potent antimicrobial activity (disc diffusion method) against Escherichia coli (inhibition zone: 15–18 mm). Shaded plants demonstrated a positive influence of essential oil against Klebsiella pneumoniae. Carvone and its derivatives, as the main components, hold significant potential in the food industry and alternative medicines. A practical implication of this study could be higher plant densities or intercropping of dill, as it thrives with minimal light.