Effect of refining of crude rice bran oil on the retention of oryzanol in the refined oil

The effect of different processing steps of refining on retention or the availability of oryzanol in refined oil and the oryzanol composition of Indian paddy cultivars and commercial products of the rice bran oil (RBO) industry were investigated. Degumming and dewaxing of crude RBO removed only 1.1 and 5.9% of oryzanol while the alkali treatment removed 93.0 to 94.6% of oryzanol from the original crude oil. Irrespective of the strength of alkali (12 to 20° Be studied), retention of oryzanol in the refined RBO was only 5.4–17.2% for crude oil, 5.9–15.0% for degummed oil, and 7.0 to 9.7% for degummed and dewaxed oil. The oryzanol content of oil extracted from the bran of 18 Indian paddy cultivars ranged from 1.63 to 2.72%, which is the first report of its kind in the literature on oryzanol content. The oryzanol content ranged from 1.1 to 1.74% for physically refined RBO while for alkali-refined oil it was 0.19–0.20%. The oil subjected to physical refining (commercial sample) retained the original amount of oryzanol after refining (1.60 and 1.74%), whereas the chemically refined oil showed a considerably lower amount (0.19%). Thus, the oryzanol, which is lost during the chemical refining process, has been carried into the soapstock. The content of oryzanol of the commercial RBO, soapstock, acid oil, and deodorizer distillate were in the range: 1.7–2.1, 6.3–6.9, 3.3–7.4, and 0.79%, respectively. These results showed that the processing steps—viz., degumming (1.1%), dewaxing (5.9%), physical refining (0%), bleaching and deodorization of the oil—did not affect the content of oryzanol appreciably, while 83–95% of it was lost during alkali refining. The oryzanol composition of crude oil and soapstock as determined by high-performance liquid chromatography indicated 24-methylene cycloartanyl ferulate (30–38%) and campesteryl ferulate (24.4–26.9%) as the major ferulates. The results presented here are probably the first systematic report on oryzanol availability in differently processed RBO, soapstocks, acid oils, and for oils of Indian paddy cultivars.     

Analog/RF and Linearity Distortion Analysis of MgZnO/CdZnO Quadruple-Gate Field Effect Transistor (QG-FET)

Silicon - In this study, the authors propose a novel MgZnO/CdZnO Quadruple-Gate Field Effect Transistor (QG-FET). The analog/RF and linearity distortion performance of the proposed QG-FET has been...     

White Si–O–C Ceramic: Structure and Thermodynamic Stability

While pyrolysis of a polysiloxane precursor in argon typically produces a black amorphous Si–O–C ceramic containing “free” carbon (sp² carbon), pyrolyzing the same precursor in hydrogen leads to a white amorphous ceramic with a negligible amount of sp² carbon and a considerable hydrogen content. ²⁹Si magic‐angle‐spinning nuclear magnetic resonance (MAS NMR) spectroscopy confirms the existence of very similar bonding environments of Si atoms in the Si–O–C network for both samples. In addition, ¹H NMR spectroscopic measurements on both samples reveal that the hydrogen atoms are bonded mainly to carbon. For the thermodynamic analysis, the enthalpies of formation with respect to the most stable components (SiO₂, SiC, C) of the black‐and‐white Si–O–C samples obtained after the pyrolysis at 1100°C are determined using high‐temperature oxidative drop‐solution calorimetry in a molten oxide solvent. The white ceramic is 6 kJ/g‐atom more stable in enthalpy than the black one. Although the role of hydrogen in the thermodynamic stability of the white sample remains ambiguous, the thermodynamic findings and structural analysis suggest that the existence of sp²‐bonded carbon in the amorphous network of polymer derived Si–O–C ceramics does not provide additional thermodynamic stability to the ceramic.     

Recent developments in P(O/S)–N containing flame retardants

Synthesis of organophosphorus compounds containing nitrogen as heteroatom and its application as a flame retardant (FR) have attracted much attention in the academic and industrial communities over the past decade. Such compounds are relatively easy to synthesize and offer advantages such as high thermal stability, which is useful for high temperature processing, improved char stability, density, and yield during the thermal decomposition of polymer, and release phosphorus species active in the flame inhibition process. Though a variety of phosphorus–nitrogen (P–N) compounds can be found in the literature, this review mostly summarizes the recent (since 2013) development in phosphorus (O)-nitrogen containing flame retardants which have been published in peer-reviewed journals. General strategies of synthesizing P(O)–N compounds as FRs from various phosphorus-based starting materials are highlighted in this review. Some of the most common classes of researched P(O)–N containing compounds as FRs include the phosphinamides, phosphonamides, phosphoramides, phosphoramidates, phosphorodiamidates, phosphonamidates and their thio counterparts which are usually obtained via a one- or two-step synthetic strategy. Incorporation of these compounds as FRs in various polymer systems such as polyurethane, epoxy resins, polyamides, cellulose, polylactide, poly(butylene terephthalate), polycarbonates, and acrylonitrile–butadiene–styrene are discussed in detail in this review. Special emphasis on the various fire and thermal performances of the new materials are also summarized. The mechanical performance of new materials and the influence of these additives on polymer processing are also briefly discussed. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 47910.     

Aqueous processing of nickel spent catalyst for a value added product

Nickel was recovered from a fertilizer industry spent catalyst by leaching with nitric acid followed by nickel hydroxide precipitation. The optimization of temperature, initial acid concentration and particle size for leaching of the spent catalyst was done through 2³ factorial design. A maximum extraction of 91.9% was achieved at 90 °C, 1.5M HNO₃ and 62.5 μm particle size. Temperature and acid concentration showed positive effect, while particle size showed no effect. A regression equation was developed and employed to predict conditions for 100% extraction which were experimentally tested. Nickel hydroxide was electrochemically precipitated from the leach liquor and its maximum discharge capacity was found to be 155 mAh/g. A 3-stage counter current leaching circuit was designed to obtain a leach liquor of suitable pH. XRD characterization of the precipitated Ni(OH)₂ shows to consist of both α- and β-forms.     

Corrosion of Borosilicate Glasses Subjected to Aggressive Test Conditions: Structural Investigations

Sodium borosilicate (NBS) and barium sodium borosilicate (BBS) glasses, used for immobilization of high‐level nuclear waste with compositions (SiO₂)_0.477(B₂O₃)_0.239(Na₂O)_0.170(TiO₂)_0.023(CaO)_0.068(Al₂O₃)_0.023 and (SiO₂)_0.482(B₂O₃)_0.244(Na₂O)_0.220(BaO)_0.054 were subjected leaching experiments under hydrothermal conditions in an autoclave at 200°C for different time durations. Morphological and structural transformations associated with leaching, have been monitored with techniques like XRD, SEM, solid‐state nuclear magnetic resonance. XRD and SEM along with NMR studies have confirmed that, upon leaching, formation of an aluminosilicate phase, Zeolite‐P (Na₆Al₆Si₁₀O₃₂·12H₂O), occurs with NBS glass. BBS glass upon subjecting to the same conditions leads to formation of multiple amorphous phases having Q⁴ (silica rich phase) and Q³ structural units of Silicon along with structurally modified residual glass. Upon leaching BO₃ structural units preferentially get released from BBS glass. Comparison of results with international simple glass confirmed that, for the latter, mass loss rates are one order of magnitude lower.