Manufacture of a transformer oil from egyptian paraffinic base stocks via a hydrogenation process

This paper describes work aimed at producing a high‐quality transformer oil from local Egyptian paraffinic base stock by hydrogenation, or hydrogenation plus sulphonation. Analysis showed that the neutral base oil 70N was suitable for producing transformer oil. This neutral base oil was chemically treated by hydrogenation under various conditions of temperature, pressure, and time, using two different catalysts, and by hydrogenation followed by sulphonation using optimum conditions. Optimum hydrogenation conditions were achieved by using a Ni/Mo (10 wt. %) catalyst, at 275°C and 100 psi pressure for 60 min, while optimum sulphonation conditions were achieved in previous work by using oleum or SO₃ gas at a concentration of 6 wt. % at 35°C for 60 min. Laboratory results and field trials indicated that the neutral paraffinic base oil when so treated meets the IEC 296 international specification for transformer oil, with the exception of the pour point (−18°C). However, this pour point is not relevant in certain hot climatic conditions. Evaluation of the treated oil with commercial transformer oil has shown its potential for use.     

Mid‐node admissible spaces for quadratic triangular 2D finite elements with one edge curved

A robust element distortion metric, based on the new concept of mid‐node admissible spaces, for two‐dimensional quadratic triangular finite elements is developed. The metric is based on the Jacobian determinant over the entire element, without requiring that it actually be computed everywhere on the element. The metric is relatively inexpensive to compute, especially for mildly distoted elements. The metric is able to detect elementsof poor quality that other distortion metrics fall to detect. It also has the ability to approve elements of good quality regardless of the extent to which they may appear geometrically distorted. Copyright © 2001 John Wiley & Sons, Ltd.     

Preparation of polyaniline and studying its electrical conductivity

Polyaniline was prepared by chemical methods. Its electrical conductivity was measured. The electrical conductivity of polyaniline salt and polyaniline base were compared with composites prepared by the hot press of polyaniline base with KBr, Co(CH₃COO)₂, and picric acid. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1658–1665, 2000     

Synthesis and characterization of novel organotin monomers and copolymers and their antibacterial activity

Two novel organotin monomers, (N‐tri‐n‐butyltin) maleimide and m‐acryloylamino‐(tri‐n‐butyltin benzoate), were synthesized. Copolymerization of these two monomers with styrene was carried out in the bulk at 65°C using asobisisobutyronitrile as the free radical initiator. The monomers and copolymers were characterized by elemental analysis; the molecular weights of the copolymers were determined by GPC, solubility, IR, and ¹H‐NMR spectral studies. The antibacterial activities of the synthesized organotin monomers and copolymers toward various types of bacteria were also reported. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 740–745, 2000     

Physico‐chemical and technological studies on sugar beet roots

The morphological and chemical characteristics of ten varieties of sugar beet roots were evaluated during the season of 1996–1997. The best morphological characteristics were found in Top, Ito and Pamela varieties. The highest expected technological yield of sugar was found in Pamela and Top. The chemical constituents of different varieties of sugar‐beet roots showed significant differences. The suitability of sugar beet juice for preparing beet syrup as a new product was also evaluated and compared with sugar cane syrup. Purified beet‐syrups concentrated under vacuum or under atmospheric pressure showed more stability during storage than sugar cane syrup. The effect of storage conditions (at cold storage and at room temperature) and packaging materials (glass and polyethylene high‐density bottles) on properties of beet‐syrup and sugar cane syrup were also studied.     

Forced in-plane flow through complex deformable structures: Influence of an imposed curve

Forced in-plane flow of liquids through contiguous flat and curved regions of confined fabrics has been studied both as a general phenomenon and for predicting the flow of polymers during injection molding of monolithic composite structures with complex configurations. A controlled pressure difference is applied to drive the flow, while the mass flow rate is measured gravimetrically by Liquid/Air Displacement Analysis (LADA). Measurements have been carried out along fabric paths that are first vertical, then curved, and finally horizontal. Fluid flow equations have been adapted for analyzing flow in the flat sections, leading to the evaluation of permeability constants and capillary pressures. A saturated flow rate measured at constant hydrodynamic pressure is used to evaluate the overall permeability coefficient of the encapsulated fabric. Data are presented showing that permeability can be reduced as a consequence of flow through the curved region.     

Nutritional Sources and Anticancer Potential of Phenethyl Isothiocyanate: Molecular Mechanisms and Therapeutic Insights

Phenethyl isothiocyanate (PEITC), a compound derived from cruciferous vegetables, has garnered attention for its anticancer properties. This review synthesizes existing research on PEITC, focusing on its mechanisms of action in combatting cancer. PEITC has been found to be effective against various cancer types, such as breast, prostate, lung, colon, and pancreatic cancers. Its anticancer activities are mediated through several mechanisms, including the induction of apoptosis (programmed cell death), inhibition of cell proliferation, suppression of angiogenesis (formation of new blood vessels that feed tumors), and reduction of metastasis (spread of cancer cells to new areas). PEITC targets crucial cellular signaling pathways involved in cancer progression, notably the Nuclear Factor kappa-light-chain-enhancer of activated B cells (NF-κB), Protein Kinase B (Akt), and Mitogen-Activated Protein Kinase (MAPK) pathways. These findings suggest PEITC's potential as a therapeutic agent against cancer. However, further research is necessary to determine the optimal dosage, understand its bioavailability, and assess potential side effects. This will be crucial for developing PEITC-based treatments that are both effective and safe for clinical use in cancer therapy.     

Aflatoxin B1, ochratoxin A and zearalenone in sorghum grains marketed in Tunisia

A total of 64 samples of sorghum (37 Tunisian sorghum samples and 27 Egyptian sorghum samples) were collected during 2011–2012 from markets in Tunisia. Samples were analysed for contamination with aflatoxin B1, ochratoxin A and zearalenone by High-Performance Liquid Chromatography Coupled with Fluorescence Detection (HPLC-FLD). Aflatoxin B1 was found in 38 samples in the range 0.03–31.7 µg kg^?1. Ochratoxin A was detected in 24 samples with concentrations ranging from 1.04 to 27.8 µg kg^?1. Zearalenone was detected in 21 samples and the concentration varied between 3.7 and 64.5 µg kg^?1. ANOVA analysis of the influence of the country of origin on the incidence and concentration of mycotoxins in the samples studied showed no significant difference (P > 0.05) between the two batches of samples for each of the three mycotoxins studied. The studied mycotoxins contaminate sorghum and may also co-exist because of the diversity of the mycobiota in this cereal.     

Effect of processing technique on the dispersion of carbon nanotubes within polypropylene carbon nanotube‐composites and its effect on their mechanical properties

Carbon nanotube‐reinforced polymer composites are being investigated as promising new materials having enhanced physical and mechanical properties. With regards to mechanical behavior, the enhancements reported thus far by researchers are lower than the theoretical predictions. One of the key requirements to attaining enhanced behavior is a uniform dispersion of the nanotubes within the polymer matrix. Although solvent mixing has been used extensively, there are concerns that any remaining solvent within the composite may degrade its mechanical properties. In this work, a comparison is carried out between solvent and “solvent‐free” dry mixing for dispersing multiwall carbon nanotubes in polypropylene before further melt mixing by extrusion. Various weight fractions of carbon nanotubes (CNTs) are added to the polymer and their effect on the mechanical properties of the resulting composites is investigated. Enhancements in yield strength, hardness, and Young's modulus when compared with the neat polymer, processed under similar conditions, are observed. Differences in mechanical properties and strain as a function of the processing technique (solvent or dry) are also clearly noted. In addition, different trends of enhancement of mechanical properties for the solvent and dry‐mixed extrudates are observed. Dry mixing produces composites with the highest yield strength, hardness, and modulus at 0.5 wt% CNT, whereas solvent mixing produces the highest mechanical properties at CNT contents of 1 wt%. It is believed that this difference is primarily dependent on the dispersion of CNTs within the polymer matrix which is influenced by the processing technique. Field emission scanning electron microscopy analysis shows the presence of clusters in large wt% CNT samples produced by dry mixing. Samples produced by solvent mixing are found to contain homogeneously distributed CNTs at all CNT wt fractions. CNT pull‐out is observed and may explain the limited enhancement in mechanical properties. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers     

Highly basic CaO nanoparticles in mesoporous carbon materials and their excellent catalytic activity

Highly basic CaO nanoparticles immobilized mesoporous carbon materials (CaO-CMK-3) with different pore diameters have been successfully prepared by using wet-impregnation method. The prepared materials were subjected to extensive characterization studies using sophisticated techniques such as XRD, nitrogen adsorption, HRSEM-EDX, HRTEM and temperature programmed desorption of CO2 (TPD of CO2). The physico-chemical characterization results revealed that these materials possess highly dispersed CaO nanoparticles, excellent nanopores with well-ordered structure, high specific surface area, large specific pore volume, pore diameter and very high basicity. We have also demonstrated that the basicity of the CaO-CMK-3 samples can be controlled by simply varying the amount of CaO loading and pore diameter of the carbon support. The basic catalytic performance of the samples was investigated in the base-catalyzed transesterification of ethylacetoacetate by aryl, aliphatic and cyclic primary alcohols. CMK-3 catalyst with higher CaO loading and larger pore diameter was found to be highly active with higher conversion within a very short reaction time. The activity of 30% CaO-CMK3-150 catalyst for transesterification of ethylacetoacetate using different alcohols increases in the following order: octanol > butanol > cyclohexanol > benzyl alcohol > furfuryl alcohol.