Composition and oxidative stability of soybean oil in mixtures with jojoba oil

Improvement of the oxidative stability of soybean oil (SBO) by blending with jojoba oil (JO) was investigated. SBO in the presence of 5, 10, 15 and 20 wt‐% of JO was subjected to accelerated storage at 60 °C. Peroxide values (PV), anisidine values (AV), UV absorption characteristics (K₂₃₂ and K₂₇₀ values), and headspace volatiles were determined to monitor the oxidative stability of oil samples. JO was effective in reducing the formation of hydroperoxides and volatile compounds in SBO. The effect was remarkable in SBO/JO blends containing 15 and 20% JO, which showed significant reductions in PV, AV and volatile content with respect to pure SBO. The increased oxidative stability of SBO/JO blends could not be attributed to JO tocopherols, since the addition of JO to SBO significantly reduced the tocopherol content of SBO. Besides the tocopherol content and unsaturation degree of SBO and JO, the effect of the JO ester structure on the oxidative stability of the blends is discussed. The enhanced chemical and flavor stabilities of SBO/JO blends with respect to pure SBO may make a significant contribution to improve the shelf life of SBO by reducing the deterioration reactions related to lipid peroxidation.     

DSC study on the melting properties of palm oil, sunflower oil, and palm kernel olein blends before and after chemical interesterification

Changes in DSC melting properties of palm oil (PO), sunflower oil (SFO), palm kernel olein (PKOo), and their belends in various ratios were studied by using a combination of blending, and chemical interesterification (CIE) techniques and determining total melting (ΔH _f ) and partial melting (ΔH _i°C ) enthalpies. Blending and CIE significantly modified the DSC melting properties of the PO/SFO/PKOo blends. PO and blends containing substantial amounts of PO and PKOo experienced an increase in their DSC ΔH _f and ΔH _i°C following CIE. The DSC ΔH _f and ΔH _i°C of PKOo, blends of PO/SFO at 1∶1 and 1∶3 ratios, and all blends of PKOo/SFO significantly decreased after CIE. The DSC ΔH _f and ΔH _i°C of SFO changed little following CIE. Randomization of FA distribution within and among TAG molecules of PO and PKOo led to modification in TAG composition of the PO/PKOo blends and improved miscibility between the two fats and consequently diminished the eutectic interaction that occurred between PO and PKOo.     

The nonchalant magnetic ordering of vacancies in graphene

Magnetic properties of graphene monolayer with mono-, di-, and tri-vacancies are studied using spin polarized density functional theory. Detailed analysis of the projected density of the state shows that the magnetic moment associated with single vacancy is due to the combination of p_z π-bonding orbital and partially delocalized sp or sp² hybridized orbitals. A study on 6 × 6 and 9 × 9 supercell reveals the delocalized nature is size independent. The very small energy difference between ferro, anti-ferro and non magnetic states in di- and tri- vacancies predict the nonchalant magnetic ordering for vacancies. Our computational results explain the experimental observations in a recent publication by Nair et al. (2013), that the magnetic response of graphene is paramagnetic, and the single vacancy has a magnetic moment contributed by both itinerant p_z orbitals and localized dangling bond. Magnetic moment associated with triple vacancy configuration is 1 μB. This moment is purely localized moment with no role played by p_z orbitals in contrast to the magnetic moment associated with single vacancy. The hydrogen passivation of tri-vacancy reveals that the conductivity in the tri-vacancy can be varied from a p type to intrinsic semiconductor type.     

Insight into the vacancy effects on mechanical and electronic properties of Tantalum Silicide

The effects of the vacancies on the structural stability, elastic constants, elastic moduli, brittle-to-ductile transition and electronic properties of Tantalum Silicide (TaSi₂) are investigated in detail by first-principles calculations. The values of vacancy formation energy confirm that the perfect TaSi₂ and TaSi₂ with different atomic vacancies can exhibit the structural stability at ground state. It is found that Ta atom vacancies are more stable than Si atom vacancies in TaSi₂ with vacancies. The elastic constants and elastic moduli describe the mechanical behavior for TaSi₂ and TaSi₂ with vacancies. The different atomic vacancies weaken the elastic stiffness for TaSi₂. But the values of B/G confirm that the brittle-to-ductile transition occurs with different atomic vacancies for TaSi₂. Although these vacancies make the shear and volume deformation resistance of TaSi₂ weaker, they obviously improve the brittle behavior of TaSi₂. The difference charge density and electronic structures are calculated to discuss and analyze the structural stability and mechanical properties for the perfect TaSi₂ and TaSi₂ with vacancies.     

Use of liquid carbon dioxide to remove hexane from soybean oil

Liquid carbon dioxide (L-CO₂) was investigated as a means to separate hexane from the mixture of soybean oil (SBO) and hexane resulting from the hexane extraction of soybeans. Using a fractionation tower, 5 vol of CO₂ (i.e., 100, 200, 300, 500, and 1000 L expanded gas) were passed through 50 mL of two concentrations of n-hexane (i.e., 10 and 25% w/w) in SBO. After passing through the hexane/SBO mixture, the expanded CO₂ was passed through a chilled collection flask to capture extracted hexane and SBO. The raffinate SBO was removed from the column and analyzed for residual hexane using International Organization for Standardization Method 9832:2002. Residual hexane decreased as the amount of L-CO₂ used increased and was less than 20 ppm after 200 L of CO₂. The amount of SBO extracted increased with the volume of CO₂ used. Significantly more SBO and hexane were collected from the 25% sample than the 10% sample. During the extraction of the mixture, the CO₂ selectively carried over TG with lower M.W. This research demonstrates the ability to use L-CO₂ to remove haxane from mixtures of hexane and SBO at both low pressures and temperatures.     

Low-temperature synthesis one-dimensional Ag2CO3/SnFe2O4 Z-scheme with excellent visible-light photoactivity

In this study, Ag₂CO₃/SnFe₂O₄ (Ag₂CO₃/SFO) photocatalyst was prepared by a simple hydrothermal-ultrasonic method for the efficient degradation of ciprofloxacin and phenol. The SFO nanoparticles were attached on the surface of Ag₂CO₃ rods synthesized by a low-temperature precipitation method, resulting a unique 1D/0D morphology, which increased the number of active sites. Due to introduction of magnetic SFO, Ag₂CO₃/SFO exhibited excellent magnetic recovery performance. When the mass fraction of SFO was 5%, the degradation efficiency of composite photocatalyst was the highest, the degradation rate for ciprofloxacin was 6.5 and 1.5 times higher than pure SFO and Ag₂CO₃, respectively. The improved photoactivity of Ag₂CO₃/SFO should be attributed to the construction of heterojunction with tight interface, which boosts the separation and transfer of photoinduced electron and hole pairs. On the basis of experimental results, a possible Z-scheme photocatalytic mechanism was discussed. Additionally, the excellent photostability of Ag₂CO₃/SFO was proved by a cycle experiment.     

Evaluation of physicochemical and biological properties of SnO2 and Fe doped SnO2 nanoparticles

In recent decades, nanoparticle synthesis has been used for various physical and chemical methods. However, different toxic chemicals are used during this synthesis process to address these concerns, which has multiple effects on environmental toxicity and high cost. To avoid these problems, we need a cost-effective and environmentally friendly approach. In this study, green synthesis was used to make tin oxide (SnO₂) and ferrous doped tin oxide (SFO) nanoparticles (NPs) from Morinda citrifolia leaf extracts. The X-ray diffraction patterns of SnO₂ and SFO NPs reveal a tetragonal crystalline structure. From the FESEM image of synthesized SnO₂ and SFO NPs, their spherical structure and chemical composition were identified by EDX spectrum. Through the DLS spectrum, the hydrodynamic size was observed at 66 and 61 nm for SnO₂ and SFO NPs, respectively. In the FTIR spectrum, the O–Sn–O stretching vibration peak arises at (606 & 509 cm^?1 for SnO₂ NPs) and (613 & 538 cm^?1 for SFO NPs). Photoluminescence is used in materials to detect surface defects and impurity levels. The antibacterial activity of the SnO₂, SFO NPs, and conventional antibiotics like amoxicillin NPs is effectively inhibited against S. aureus and E. coli bacterial strains. SFO NPs exhibit a higher antibacterial activity as compared to SnO₂ and amoxicillin. The anticancer efficacy of increased SFO NPs compared to SnO₂ NPs was tested against (MDA-MB-237) human breast cancer cells. These results suggest that Fe ions modified SnO2 NPs could be used in healthcare industrial applications to improve human health.     

Effects of Fats and Oils on Rheological, Fatty Acid Profile and Quality Characteristics of South Indian Parotta

Keeping in view the present day demand for foods with healthy fats, the effect of different fats namely hydrogenated fat (HF) and bakery fat (BF); oils—sunflower oil (SFO), soyabean oil (SBO), olive oil (OLO), palm oil (POO) and coconut oil (CNO) separately at the level of 7.5 % on the rheological, fatty acid profile and quality characteristics of parotta was studied. Addition of fats and oils decreased Farinograph water absorption, Amylograph peak viscosity, Alveograph resistance of dough to deformation and increased average abscissa at rupture. In the micrographs of parotta dough with fats, the protein matrix appeared thick and intact, whereas in the case of parotta dough with oils the protein matrix appeared slightly less intact. The spread ratio and overall quality of parotta with oils were higher than fats. The highest overall quality score was observed for parotta with OLO, followed in decreasing order by SFO, SBO, CNO, POO, HF and BF. Determination of fatty acid profile showed that the parottas with fats contained a high amount of trans fatty acids (TFA), while parottas with oils had no TFA. During storage up to 48 h, the parottas with oils remained softer than the parottas with fats.     

Plasma Phospholipid Fatty Acid and Ex Vivo Neutrophil Responses are Differentially Altered in Dogs Fed Fish- and Linseed-Oil Containing Diets at the Same n-6:n-3 Fatty Acid Ratio

The effect of diets containing either 18-carbon n-3 fatty acids (FA) or 20/22-carbon n-3 FA on canine plasma and neutrophil membrane fatty acid composition, superoxide and leukotriene B₄ and B₅ production when fed at the same n-6:n-3 fatty acid ratio was investigated. Four groups of ten dogs each were fed a low fat basal diet supplemented with safflower oil (SFO), beef tallow (BTO), linseed oil (LSO), or Menhaden fish oil (MHO) for 28 days. Dietary fat provided 40.8% of energy and the n-6:n-3 of the diets were ~100:1, 9.7:1, 0.38:1, and 0.34:1 for the SFO, BTO, LSO and MHO groups, respectively. The MHO and LSO groups had increased incorporation of EPA and DPA in both the plasma and neutrophil membranes compared to the BTO and SFO groups. DHA was observed in the MHO but not in the LSO group. Neutrophils from the MHO diet fed dogs had less LTB₄ and greater LTB₅ than the other three groups. The LSO group also showed a reduction in LTB₄ and greater LTB₅ production compared to the SFO and BTO groups. Both LSO and MHO groups had lower superoxide production compared to the SFO and BTO groups. Diets containing 18 or 20/22 carbon n-3 FA fed at the same n-6:n-3 resulted in differential incorporation of long chain n-3 FA into neutrophil membranes. Thus, fatty acid type and chain length individually affect neutrophil membrane structure and function and these effects exist independent of dietary total n-6:total n-3 FA ratios.     

Semiconductor nanomembranes: a platform for new properties via strain engineering

??-Al₂O₃ is a porous metal oxide and described as a defective spinel with some cationic vacancies. In this work, we calculate the electronic density of states and band structure for the bulk of this material. The calculations are performed within the density functional theory using the full potential augmented plan waves plus local orbital method, as embodied in the WIEN2k code. We show that the modified Becke-Johnson exchange potential, as a semi-local method, can predict the bandgap in better agreement with the experiment even compared to the accurate but much more expensive green function method. Moreover, our electronic structure analysis indicates that the character of the valence band maximum mainly originates from the p orbital of those oxygen atoms that are close to the vacancy. The charge density results show that the polarization of the oxygen electron cloud is directed toward aluminum cations, which cause Al and O atoms to be tightly connected by a strong dipole bond.     

A DFT study of electronic structures, energies, and molecular properties of lithium bis[croconato]borate and its derivatives

Theoretical studies on electrolyte salts, lithium bis[croconato(2-)]borate (LBCB) and its derivatives, lithium [croconato(2-) salicylato(2-)]borate (LCSB), and bis[salicylato(2-)]borate (LBSB) are carried out using density functional theory (DFT) method and B3LYP theory level for the first time. Bidentate structures involving two oxygen atoms are preferred. Based on these conformations, a linear correlation was observed between the highest occupied molecular orbital (HOMO) energies and the limiting oxidation potentials measured by linear sweep voltammetry, which supports experimental results that strongly electron-withdrawing substituent anions are more resistant against oxidation than their organic counterparts. The correlations were also observed between ionic conductivity and binding energy, solubility and theoretical set of parameters of anion_, thermal stability and the hardness (η)_. Wave function analyses have been performed by natural bond orbital (NBO) method to further investigate the cation-anion interactions.     

The passivity of AISI 316L stainless steel in 0.05 M H2SO4

The passivity of AISI 316L stainless steel (AISI 316L) in 0.05 M H₂SO₄, in the steady-state condition, has been explored using various electrochemical techniques, including potentiostatic polarization, electrochemical impedance spectroscopy (EIS), and Mott–Schottky analysis. Based on the Mott–Schottky analysis in conjunction with the point defect model (PDM), it was shown that the calculated donor density decreases exponentially with increasing passive film formation potential. The thickness of the barrier layer was increased linearly with the film formation potential. These observations were consistent with the predictions of the PDM, noting that the point defects within the barrier layer of the passive film are metal interstitials, oxygen vacancies, or both. Also no evidence for p-type behavior was obtained, indicating that cation vacancies do not have any significant population density in the passive film.     

Low-temperature phase behavior of vegetable oil/co-solvent blends as alternative diesel fuel

Vegetable oils (triacylglycerols) have many characteristics that make them attractive candidates as renewable alternative fuels for compression-ignition (diesel) engines. Unfortunately, vegetable oils are too viscous to be compatible with modern direct-injection diesel fuel systems and engines. Co-solvent blending is a simple and flexible technology that reduces viscosity by mixing the oil with low molecular weight alcohol. A co-solvent (A), consisting, of surfactant plus an amphiphilic compound, is added to solubilize otherwise nearly immiscible oil-alcohol mixtures into a single-layer (isotropic) solution. This work examines low-temperature phase behavior of two soybean oil (SBO)/methanol mixtures solubilized by A=unsaturated long-chain (C₁₈) fatty alcohol/medium-chain alkanol (n-butanol and 2-octanol), one SBO/methanol mixture solubilized by A=triethylammonium linoleate/2-octanol, and one SBO/95 wt% ethanol (E95) mixture solubilized by n-butanol. The E95-blend was further blended in 1∶1 (vol/vol) mixtures with No. 2 diesel fuel. Two types of anisotropic phase behavior were observed; formation of a cloudy layer of solid crystals suspended in bulk solution (Type 1) and formation of two immiscible liquid layers (Type II). The type of phase separation in a given solution was influenced by phase separation temperature (T _ϕ) relative to the crystallization characteristics of compounds in the SBO and fatty alcohol or amine constituents present in solution. Solutions with relatively low T _ϕ values experienced crystallization of small solid particles favoring Type 1 separations. Conversely, solutions with T _ϕ sufficient to avert crystallization of high melting point compounds favored Type II separations where T _ϕ=critical solution temperature (T _critical). Increasing the A/oil (SBO or No. 2 diesel/SBO mixture) mass ratio decreased T _ϕ while increasing the mass fraction of alcohol (methanol or E95) increased T _ϕ. This work shows that vegetable oil/A-based blends can be formulated with cold flow properties superior with respect to cloud point and comparable with respect to kinematic viscosity (v) of methyl soyate (biodiesel), either neat or blended with petroleum middle distillates. Retired     

Effect of laser power density on the electrochromic properties of WO3 films obtained by pulsed laser deposition

Pulsed laser deposition (PLD) was used to prepare tungsten trioxide (WO₃) films on ITO substrates with a varying laser power density of 4.0–5.5 W/cm². XPS indicated that when the laser power density decreased, the peak positions of the W 4f and O 1s orbits shifted slightly to low energy due to the difference in oxygen vacancies. As the laser power density decreased, W⁶⁺ gradually replaced the lattice position of O^2?, increasing oxygen vacancies in the lattice. The transmittance modulated values (ΔT) were over 44% at 830 nm, indicating strong absorption by the WO₃ thin films in the near-infrared ray. The switching time of the WO₃ thin films between bleached states and coloured states decreased as the laser power density increased due to the amorphous structure, morphology, and lower oxygen deficiency at a high power density. The high ΔT and very fast switching time of t_b (1.09 s) and t_c (6.01 s) demonstrated the excellent electrochromic (EC) properties of the WO₃ films prepared by PLD.     

Effect of cooling rate on crystallization behavior of milk fat fraction/sunflower oil blends

The effect of cooling rate (slow: 0.1°C/min; fast: 5.5°C/min) on the crystallization kinetics of blends of a highmelting milk fat fraction and sunflower oil (SFO) was investigated by pulsed NMR and DSC. For slow cooling rate, the majority of crystallization had already occurred by the time the set crystallization temperature had been reached. For fast cooling rate, crystallization started after the samples reached the selected crystallization temperature, and the solid fat content curves were hyperbolic. DSC scans showed that at slow cooling rates, molecular organization took place as the sample was being cooled to crystallization temperature and there was fractionation of solid solutions. For fast cooling rates, more compound crystal formation occurred and no fractionation was observed in many cases. The Avrami kinetic model was used to obtain the parameters k _n and n for the samples that were rapidly cooled. The parameter k _n decreased as supercooling decreased (higher crystallization temperature) and decreased with increasing SFO content. The Avrami exponent n was less than 1 for high supercoolings and close to 2 for low supercoolings, but was not affected by SFO content.     

Trans-free margarine from highly saturated soybean oil

Highly saturated (HS) soybean oil (SBO), which contained 23.3% palmitic acid (C_16:0) and 20.0% stearic acid (C_18:0), was interesterified at 70°C in preparation for the processing of a trans-free margarine. High-performance liquid chromatography analysis of the triacylglycerides and analysis of the sn-2 fatty acid composition showed no further change after 10 min of interesterification. The interesterified HS SBO had a slip melting point of 34.5°C, compared with 9.5°C in the non-interesterified HS SBO, and increased melting and crystallization temperatures were found using differential scanning calorimetry. Analysis of solid-fat content by nuclear magnetic resonance revealed the presence of only a small amount of solids above 33°C. A 50:50 blend of interesterified HS SBO and SBO with a typical fatty acid composition was used to make the margarine. Compared to commercial soft-tub margarine, the maximal peak force on the texture analyzer of this blended margarine was about 2.3 times greater, the hardness about 2.6 times greater, and adhesiveness about 1.5 times greater. There were small but statistically significant differences (α=0.05) in the sensory properties of spreadability, graininess, and waxiness between the commercial and blended margarines at 4.5°C and, except for graininess, at 11.5°C. These very small differences suggest a potential use for HS SBO in margarine products.     

An ab initio study on properties of cationic chalcogen bonds in XF2Y+⋯NCZ (X═H,CN, F; Y═S,Se; Z═H,Cl, Br) complexes

The geometries, interaction energies, and bonding properties of cationic chalcogen bonds are studied in binary complexes XF₂Y⁺?NCZ (X═H, CN, F; Y═S, Se; Z═H, Cl, Br). The nature of these interactions is studied by a vast number of methods, including molecular electrostatic potential (MEP), Noncovalent Interaction Index (NCI), quantum theory of atoms in molecules (QTAIM), and natural bond orbital (NBO) analyses. The interaction energies of these complexes vary between ?20.94?kcal/mol in HF₂S⁺?NCH and ?33.72?kcal/mol in F₃Se⁺?NCBr. According to the QTAIM analysis, all these cationic chalcogen bonds are classified as a closed-shell interaction with a partial covalent character. Moreover, cooperative effects between cationic chalcogen bond and hydrogen or halogen bond interactions are studied in ternary XF₂Y⁺?NCZ?NH₃ complexes. These cooperative effects are analyzed in terms of the parameters derived from the QTAIM and NBO analyses, and electron density difference plots.     

Low-temperature flow properties of vegetable oil/cosolvent blend diesel fuels

Vegetable oils are an attractive renewable source for alternative diesel fuels. However, the relatively high kinematic viscosity of vegetable oils must be reduced to make them more compatible with conventional compression-ignition engines and fuel systems. Cosolvent blending is a low-cost and easy-to-adapt technology that reduces viscosity by diluting the vegetable oil with a low-M.W. alcohol (methanol or ethanol). The cosolvent (A), which consists of one or more amphiphilic compounds, is added to solubilize the otherwise nearly immiscible oil-polar alcohol mixture. This work investigates cold flow properties and phase equilibrium behavior associated with blends consisting of soybean oil (SBO) and methanol where A=8∶1 (mol) n-butanol/oleyl alcohol; 6∶1 (mol) 2-octanol/triethylammonium linoleate; and 4∶1 (mol) 2-octanol/Unadol 40 (alcohols from SBO FA); and a blend of 2∶1 (vol/vol) No. 2 diesel fuel/SBO and 95% ethanol where A=n-butanol. Cloud point (CP), pour point, cold filter plugging point (CFPP), and low-temperature flow test (LTFT) results were compared with corresponding phase separation temperature (T _ϕ) data measured at equilibrium. Although CP data were measured under non-equilibrium experimental conditions, a nearly linear correlation was found between T _ϕ and CP. Statistical analysis showed that T _ϕ may also be correlated with CFPP and LTFT. Analysis of heating and cooling DSC curves indicated that peak temperatures may be employed to predict cold flow properties and T _ϕ behavior for SBO/cosolvent blends. Cooling curve parameters correlated more readily than heating curve parameters. Finally, relatively low quantities of heat evolved during freezing indicated that crystallization in the SBO/cosolvent blends studied in this work occurs easily during cooling.     

Investigations on the matrix composite [BiFeO3(BFO)-ZnFe2O4 (ZFO)-SrFe12O19(SFO)]’s magneto-dielectric characteristics and its application of technology

Citrate auto-combustion method was employed to create Bi-perovskite (BFO), Zn-ferrite (ZFO) and Sr-hexaferrites (SFO) nanoparticles, which were then mixed up to form matrix composite which used to separate the lead metal ions from wastewater. Based on XRD peaks, the crystallite size was between 30 and 52 nm. The particles' FTIR spectra clearly show that each synthesized compound has unique functional groups. The samples had agglomeration, with each agglomerate including many grains, as shown by the SEM micrographs. The energy band gap of SFO was enhanced and reduced from 3.5 to 1.5 eV by adding BFO and ZFO. For magnetic study, T_C as well as μ_eff of BFO and ZFO were improved by adding SFO. While the dielectric properties for pure SFO was enhanced after adding BFO and ZFO in the nanocomposite, in this research paper author succeed in preparing nanosample with upgrading magnetic, optical and electric properties more than individual samples’ properties. The synthetic BFO/ZFO/SFO nanocomposite produced impressive results in the treatment of wastewater due to their enormous surface area, regulated size, well-defined structure, and high magnetic, optical and electric properties. Kinetic and isotherm analysis are applied to the experimental results. The high correlation coefficient indicates the adsorption of heavy metal ions, which is described by the Langmuir and Freundlich isotherms (R²). For the 97% removal of Pb (II) from wastewater at a contact duration of 40 min at room temperature and pH 7.     

Effect of Acid Value on TBHQ and BHT Losses in Heating Oils: Identification of the Esterification Products of TBHQ and Free Fatty Acids

The loss of phenolic antioxidants is one of the major problems associated with the food frying process. As temperature increases and heating time is prolonged, losses of both tertiary butylhydroquinone (TBHQ) and butylated hydroxytoluene (BHT) are significantly increased. In this work, the effect of different types of free fatty acids (FFA) and the acid value (AV) of soybean oil (SBO) on TBHQ and BHT losses during heating were systematically studied. The results showed that the higher the AV of SBO at 120 or 180 °C, the greater the TBHQ loss. The type of FFA also had an observable effect on TBHQ losses at both temperatures, whereas FFA type had no effect on BHT losses. Employing high performance liquid chromatography and liquid chromatography–mass spectra (LC–MS analysis, it was determined that esterification of TBHQ with FFA (C_8:0, C_18:0, C_18:1) occurred at 120 or 180 °C, whereas esterification of BHT with FFA (C_8:0, C_18:0, C_18:1) in SBO was not observed. Nuclear magnetic resonance analysis showed that esterification occurred at the 4-position of TBHQ.