Effect of processing on the composition and oxidative stability of coconut oil

The effect of various processing procedures on the composition and oxidative stability of coconut oil has been studied. The crude oil is relatively stable but major reductions in oxidative stability occur during the bleaching of oil degummed with phosphoric acid; during alkali refining; during the deodorization of oil degummed with citric acid and bleached; and during the deodorization of oil processed with a combined phosphoric acid degumming and bleaching operation. The reasons for the loss of oxidative stability during processing are discussed with reference to changes in the composition of the oil. Residual traces of citric acid or phosphoric acid play an important role in stabilizing processed oils. The tocopherol content is also important, although no additional stabilization of the oil occurs on adding levels of tocopherol above those present naturally in the crude oil. A combined phosphoric acid degumming and bleaching process leads to smaller losses of tocopherols than sequential treatments.     

An ultra-high pressure sensor with cylinder structure

Based on strain-resistance effect, an ultra-high pressure sensor has been developed with the range of 0–500 MPa. It is mainly composed of the elastic element and sensitive element. This sensor’s range is determined by the elastic element’s structure and material. In order to endure the ultra-high pressure, the elastic element’s material is selected as spring steel, and its structures are analyzed and simulated. After that, the metal strain gauge as the sensitive element is packaged on the elastic element. Then the sensor is developed after some compensation processes are carried out. In the end, the sensor is calibrated. The results show that the sensor has good performance, such as the accuracy of 0.35%FS, which meets the requirements of aerospace, weapons and other fields.     

EXPERIMENTAL INVESTIGATIONS INTO THE INFLUENCE OF MAJOR OPERATING PARAMETERS DURING MICRO-ELECTRO DISCHARGE DRILLING OF CEMENTED CARBIDE

Present study investigates the influence of major operating parameters on the performance of micro-EDM drilling of cemented carbide (WC-10wt%Co) and identifies the ideal values for improved performance. The operating parameters studied were electrode polarity, gap voltage, resistance, peak current, pulse duration, pulse interval, duty ratio, electrode rotational speed and EDM speed. The performance of micro-EDM drilling process was evaluated by machining time, material removal rate (MRR), relative electrode wear ratio (RWR), spark gap, surface finish and dimensional accuracy of micro-holes. It has been found that there are two major conflicting issues in the micro-EDM of carbide. If the primary objective is to obtain better surface finish, it can be obtained by the sacrifice of high machining time, low MRR and high RWR. However, for faster micro-EDM, the surface roughness is higher and electrode wear is again much higher. It is concluded that negative electrode polarity, gap voltage of 120 V, resistance of 33 Ω, peak current of 8 A, pulse duration of 21 μs, pulse interval of 30 μs, duty cycle of 0.47, electrode rotational speed of 700 rpm and EDM speed of 10 μm/s can be considered as ideal parameters to provide improved performances during the micro-EDM of WC-Co.     

The effects of processing parameters on formation of nano-spinel (MgAl2O4) from LiCl moltensalt

Nano-MgAl₂O₄ particles were successfully synthesized at 850 °C using the molten-salt method, and the effects of processing parameters, such as temperature, holding time and amount of salt on the crystallization of MgAl₂O₄ were investigated. Nano-alumina, magnesia and lithium chloride were used as starting materials. LiCl molten salt provided a liquid medium for reaction of Al₂O₃ and MgO to form MgAl₂O₄. The results demonstrated that MgAl₂O₄ started to form at about 650 °C and that, after the temperature was increased to 1000 °C, the amounts of MgAl₂O₄ in the resultant powders increased with a concomitant decrease in Al₂O₃ and MgO contents. After washing with hot-distilled water, the samples heated for 3 h at 850 °C were single-phase MgAl₂O₄ with 30–50 nm particle size. Furthermore, the synthesized MgAl₂O₄ particles retained the size and morphology of the Al₂O₃ powders, which indicated that a template formation mechanism dominated the formation of MgAl₂O₄ by molten-salt method.     

Thermal,Mechanical and Morphological Characterization of Jute/Gelatin Composites

Jute fabrics/gelatin biocomposites were fabricated using compression molding. The fiber content in the composite varied from 20–60 wt%. Composites were subjected to mechanical, thermal, water uptake and scanning electron microscopic (SEM) analysis. Composite contained 50 wt% jute showed the best mechanical properties. Tensile strength, tensile modulus, bending strength, bending modulus and impact strength of the 50% jute content composites were found to be 85 MPa, 1.25 GPa, 140 MPa and 9 GPa and 9.5 kJ/m², respectively. Water uptake properties at room temperature were evaluated and found that the composites had lower water uptake compared to virgin matrix.     

The effect of magnetic and optic field in water electrolysis

Hydrogen production via water electrolysis was studied under the effect of magnetic and optical field. A diode solid state laser at blue, green and red were utilized as optical field source. Magnetic bar was employed as external magnetic field. The green laser has shown a greatest effect in hydrogen production due to its non-absorbance properties in the water. Thus its intensity of electrical field is high enough to dissociation of hydronium and hydroxide ions during orientation toward polarization of water. The potential to break the autoprotolysis and generate the auto-ionization is the mechanism of optical field to reveal the hydrogen production in water electrolysis. The magnetic field effect is more dominant to enhance the hydrogen production. The diamagnetic property of water has repelled the present of magnetic in water. Consequently the water splitting occurs due to the repulsive force induced by the external magnetic field. The magnetic distributed more homogenous in the water to involve more density of water molecule. As a result hydrogen production due to magnetic field is higher in comparison to optical field. However the combination both fields have generated superior effect whereby the hydrogen yields nine times higher in comparison to conventional water electrolysis.     

Surface modification of henequen (Agave fourcroydes) fibers by ultraviolet curing with 2‐hydroxyethylacrylate and ethylacrylate: Effect of additives on degradable properties

Henequen fibers were grafted with a double impregnating monomer 2‐hydroxyethylacrylate (HEA) and ethylacrylate (EA) to improve the physicomechanical properties. The fibers soaked in different concentration (1–10%) of monomer + MeOH solution along with photoinitiator Irgacure 907 [2%] were cured under ultraviolet (UV) lamp at different UV radiation intensities (2–14 passes). Concentration of monomer at different radiation intensities was optimized with extent of mechanical properties such as polymer loading, tensile strength, and elongation at break. Enhanced tensile strength (268%) and elongation at break (110%) were achieved by the polymer treated fibers than untreated virgin fibers. We observed that, henequen fibers treated by 3% EA showed better physico‐mechanical properties than those treated by 5% HEA. The tensile properties of henequen fibers treated by 3% EA can be enhanced by adding aloxysilane; 3‐(trimethoxysilyl) propylmethacrylate additives with bulk monomer EA (3%). The degradability of the treated and untreated fibers due to accelerated weathering were also studied and it has been found that surface modified henequen fibers produced more resistivity towards different weathering conditions than untreated fibers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4000–4006, 2006     

Synthesis of a polyaminophosphonate and its evaluation as an antiscalant in desalination plant

The cationic monomer, N,N‐diallyl‐3‐(diethylphosphonato)propylammonium chloride, was cyclopolymerized in aqueous solutions using t‐butylhydroperoxide (TBHP) or ammonium persulfate (APS) as initiators to afford a cationic polyelectrolyte (CPE) having a (diethylphosphonato)propyl pendent. The CPE on acidic hydrolysis of the diester groups gave pH‐responsive polyzwitterionic acid (PZA) which on treatment with one and two equivalents NaOH gave zwitterionic/anionic polyelectrolyte (ZAPE) and dianionic polyelectrolyte (DAPE), respectively. The solution properties of the CPE, PZA, ZAPE, and DAPE were investigated in detail by viscometric technique. For the purpose of comparison, the solution properties of the polymers were correlated to a structurally similar polyzwitterion (PZ) having monoethylphosphonate and NH⁺ groups. When performance evaluation was carried out for application in reverse osmosis (RO) plants, DAPE at a concentration of 10 ppm in brackish water feed proved very effective as an inhibitor against calcium sulfate scale. POLYM. ENG. SCI., 54:166–174, 2014. © 2013 Society of Plastics Engineers     

Arsenic removal with iron(II) and iron(III) in waters with high silicate and phosphate concentrations

Arsenic removal by passive treatment, in which naturally present Fe(II) is oxidized by aeration and the forming iron(III) (hydr)oxides precipitate with adsorbed arsenic, is the simplest conceivable water treatment option. However, competing anions and low iron concentrations often require additional iron. Application of Fe(II) instead of the usually applied Fe(III) is shown to be advantageous, as oxidation of Fe(II) by dissolved oxygen causes partial oxidation of As(III) and iron(III) (hydr)oxides formed from Fe(II) have higher sorption capacities. In simulated groundwater (8.2 mM HCO3(-), 2.5 mM Ca2+, 1.6 mM Mg2+, 30 mg/L Si, 3 mg/L P, 500 ppb As(III), or As(V), pH 7.0 +/- 0.1), addition of Fe(II) clearly leads to better As removal than Fe(III). Multiple additions of Fe(II) further improved the removal of As(II). A competitive coprecipitation model that considers As(III) oxidation explains the observed results and allows the estimation of arsenic removal under different conditions. Lowering 500 microg/L As(III) to below 50 microg/L As(tot) in filtered water required > 80 mg/L Fe(III), 50-55 mg/L Fe(II) in one single addition, and 20-25 mg/L in multiple additions. With As(V), 10-12 mg/L Fe(II) and 15-18 mg/L Fe(III) was required. In the absence of Si and P, removal efficiencies for Fe(II) and Fe(III) were similar: 30-40 mg/L was required for As(II), and 2.0-2.5 mg/L was required for As(V). In a field study with 22 tubewells in Bangladesh, passive treatment efficiently removed phosphate, but iron contents were generally too low for efficient arsenic removal.