Current-source parallel-resonant DC/DC converter

This paper introduces, analyzes, and experimentally verifies a novel DC/DC converter called the current-source parallel-resonant converter. The converter consists of a large choke inductor, two switches, and a parallel-resonant circuit. Each switch consists of a MOSFET in series with a diode. It has a nonpulsating input current with a very low AC ripple. The MOSFETs are driven with respect to ground and, therefore, have a simple gate-drive circuit. The analysis of the converter is carried out in the frequency domain using Fourier series techniques. Analytical expressions are derived for performance parameters of the converter. A prototype of the converter circuit was designed, built, and tested. The theoretical results were in good agreement with the experimental results     

Comparative Analysis of the Physico-Chemical,Thermal, and Oxidative Properties of Winged Bean and Soybean Oils

To explore possible food applications, the oxidative stability, antioxidants contents (tocopherols and tocotrienols), thermal properties, and solid fat content of winged bean oil were investigated along with soybean oil for comparison. Results showed that winged bean oil was significantly (p < 0.05) resistant to oxidation (27 h) compared to soybean oil (9 h) heated at 110^oC for 32 h, due presumably to the presence of alpha tocotrienol and the high behemic acid content. The high content of tocopherols, 230 mg/100 g in soybean oil did not contribute much to its oxidation stability. At around 25^oC, winged bean oil contained about 15% solid fat content with <1% in soybean oil. Soybean oil, however, had better levels of the omega-3 and omega-6 fatty acids with a ratio of 7.6:1, falling within the range of 5:1 and 10:1 recommended by the Food and Agriculture Organization/World Health Organization, when compared to winged bean oil having a ratio of 34.4:1. The positional fatty acids esterified as stearoyl, palmitoyl, behemoyl or lignoceroyl triacylglycerides species, PSP, PPP, PLB, POB and SSlg+PBP overwhelmed the unsaturated FAs of winged bean oil for free radical reaction and also conferred it high thermal conductivity. The high oxidative stability, solid fat content, and thermal conductivity of winged bean oil coupled with its crystalization characteristics confirmed it to be good material for frying and for making zero-trans-fat margarines and spreads.     

Comparative Study of Table Margarine Prepared from Moringa oleifera Seed Oil‐Palm Stearin Blend and Commercial Margarines: Composition,Thermal, and Textural Properties

This study aims to produce an oleic acid‐rich table margarine from Moringa oleifera seed oil (MoO)‐palm stearin (PS) blend (70:30, w/w) and compare its composition, thermal behavior, and textural properties during storage with those of commercial margarines (CM1 and CM2). The major fatty acid in MoO/PS blend, CM1 and CM2 is oleic acid (67.85%, 38.54%, and 35.35%, respectively). Hence, many of their triacylglycerols are derived from the acid. MoO/PS blend has a higher complete melting temperature (43.50 °C) compared to CM1 (35.50 °C) and CM2 (35.53 °C). The solid fat content (SFC) of MoO/PS blend at 10 °C (28.7%) is lower than CM1 (32%) and CM2 (68.4%). However, the MoO/PS blend has a higher SFC (6.47%) at 35 °C compared to CMs. At 20 °C, the viscosity of experimental blend margarine (EBM) decreases but CM1 and CM2 increase at the end of the storage study. After 8 weeks of storage, all margarines are harder and CM2 is the hardest. The adhesiveness of EMB and CM2 is similar to the fresh samples while CM1 is more adhesive after storage. In short, it is possible to produce an oleic acid‐enriched margarine from MoO/PS blend that has better textural properties. Practical Applications: Moringa oleifera seed oil is one of the superior oils that contains high levels of oleic acid. However, its high iodine value and low melting point limit its application in the production of margarine. This study shows that direct blending of M. oleifera seed oil with palm stearin could produce margarine with high oleic acid contents and better textural properties in terms of viscosity, hardness, and adhesiveness. The informative data provide supporting evidence for blending of M. oleifera seed oil with palm stearin to produce margarine that could overcome the issues that hinder the M. oleifera seed oil from being produced into margarine.     

Exploration of Multiverse Activities of Endocannabinoids in Biological Systems

Over the last 25 years, the human endocannabinoid system (ECS) has come into the limelight as an imperative neuro-modulatory system. It is mainly comprised of endogenous cannabinoid (endocannabinoid), cannabinoid receptors and the associated enzymes accountable for its synthesis and deterioration. The ECS plays a proven role in the management of several neurological, cardiovascular, immunological, and other relevant chronic conditions. Endocannabinoid or endogenous cannabinoid are endogenous lipid molecules which connect with cannabinoid receptors and impose a fashionable impact on the behavior and physiological processes of the individual. Arachidonoyl ethanolamide or Anandamide and 2-arachidonoyl glycerol or 2-AG were the endocannabinoid molecules that were first characterized and discovered. The presence of lipid membranes in the precursor molecules is the characteristic feature of endocannabinoids. The endocannabinoids are released upon rapid enzymatic reactions into the extracellular space via activation through G-protein coupled receptors, which is contradictory to other neurotransmitter that are synthesized beforehand, and stock up into the synaptic vesicles. The current review highlights the functioning, synthesis, and degradation of endocannabinoid, and explains its functioning in biological systems.     

Biodegradation of Wool by Bacteria and Fungi and Enhancement of Wool Quality by Biosurfactant Washing

Biodegradation of Ryeland and Shetland wool by Bacillus subtilis W3 and Streptomyces albidoflavus were investigated. The effect of treating raw wool with Rhamnolipid was also studied. It is shown that the wool surface morphology is improved with effective displacement of surface contaminants revealing a smooth outer cuticle layer after just 2 days. These results have important practical implications for the establishment of a quick and easy biodegradable process for wool scouring finishing in textile industry or for the pre-treatment of keratinous waste materials before degradation by bacteria or fungi. This methodology provides an environmentally friendly alternative to conventional chemical pre-treatments.     

Application of Headspace Solid-Phase Microextraction and Gas Chromatography for the Analysis of Furfural in Crude Palm Oil

Processing of vegetative material containing pentoses has been shown to result in the formation of furfural. Furfural exhibits a spectrophotometric absorption peak at 518 nm when complexed with aniline acetate. Headspace solid-phase microextraction (HS-SPME) method has been successfully used to confirm the presence of furfural in crude palm oil (CPO). Solid phase microextraction (SPME) fiber composed of divinylbenzene/Carboxen/polydimethylsiloxane (DVB/PDMS/CAR) was used to absorb the volatiles in the headspace of the oil. The isolated compounds from the fiber was desorbed and separated on a capillary polar column of a gas chromatograph. Response surface methodology (RSM) was used to optimize the SPME fiber condition for maximum absorption of furfural from CPO. The optimized temperature and time for furfural extraction onto the SPME fiber are 70 °C for 40 min. Oils obtained from the mill were found to contain between 2 and 13% furfural.     

Extraction of oil from tiger nut (Cyperus esculentus L.) with supercritical carbon dioxide (SC-CO2)

Supercritical carbon dioxide (SC-CO₂) was used to extract oil from tiger nuts and the physicochemical properties and the impact of extraction conditions [i.e., temperature (40 °C–80 °C), pressure (20–40 MPa) and time (60–360 min)] on the oil yield were studied. The response surface analysis results revealed that the oil yield was significantly (P < 0.05) influenced by the main effect of the extraction pressure, extraction time and their quadratic effects respectively. However, the interaction between the extraction temperature and time had no significant (P > 0.05) effect on the oil yield. The highest oil yield was 26.28 g/100 g sample after 210 min of extraction time at 30.25 MPa and 60 °C respectively. The fatty acid composition of oils obtained by SC-CO₂ and Soxhlet showed marked variation. Also, the fatty acid composition varied depending on the operating conditions. The viscosity of the oil decreased with the increase in temperature.