Pervaporation of MTBE/methanol mixtures through PVA membranes

Sorption and pervaporation experiments were carried outwith PVA/PAA cross-linked membranes for the separation of azeotropic methyl tert-butyl ether and methanol mixtures. The influence of the PVA/PAA ratio and liquid mixture composition were investigated. With increasing PAA content in the membranes, solubilities and fluxes decreased and selectivities increased. Total sorption and fluxes increased with increasing concentration of McOH. Increasing the concentration of McOH resulted in decreasing selectivities. Because of polarity, McOH permeated selectively through the membranes. Sorption results showed the same tendency with pervaporation results.     

Polymeric Side Chain Thioxanthone Photoinitiator for Free Radical Polymerization

Summary Side chain thioxanthone-containing polymer (PSt-TX) was synthesized and characterized by modification of polystyrene prepared by Atom Transfer Radical Polymerization. PSt-TX exhibits absorption characteristics similar to that of the unsubstitued thioxanthone. Its capability to act as initiator for the polymerization of methyl methacrylate was also examined.     

Heterogeneous catalytic degradation of cyanide using copper-impregnated pumice and hydrogen peroxide

The main objective of this research was to investigate the oxidative destruction of free cyanide with hydrogen peroxide and copper-impregnated pumice as a heterogeneous catalyst. Original or copper-impregnated pumices added alone were not effective adsorbents of negatively charged cyanide ions due to incompatible surface interactions. Peroxide and original pumices added together were also ineffective in removing cyanide. However, for all of the three natural pumices tested with various particle size fractions, the use of copper-impregnated pumices and peroxide together significantly enhanced both the initial rate and extent of cyanide removal. Although copper-impregnated specific surface area was the major factor affecting the rate and extent of cyanide destruction for a particular pumice source with similar surface chemistries, the type of surface chemistry (i.e., specific functional groups) within different pumice sources also appears to be a very important factor. Lower rates and extents of cyanide removals were observed at pH 11 compared to pH 8 probably because of the negative impacts of alkaline conditions in terms of scavenging peroxide and forming more negatively charged pumice surfaces. Both the initial rate and ultimate extent of cyanide removals were generally higher at a temperature of 20 degrees C compared with those found at 10 degrees C. The use of copper-impregnated pumice as a light, cheap, readily available, natural, and porous heterogeneous catalyst either in completely mixed/suspended or fixed-bed reactor configurations may be an effective treatment technology for cyanide removal from solution. This new approach may minimize downstream metal removal problems experienced in conventional cyanide oxidation technologies.     

Copper oxide- and copper-modified antibacterial ceramic surfaces

In the present study, copper oxide (CuO) and copper (Cu) particles were characterized and investigated to observe the effects of antimicrobial activity on ceramic tile surfaces. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques were used for particle characterization. A new formulation of antimicrobial glaze was achieved by the combination of two glaze compositions with different Cu and CuO content to obtain micro–nano hybrid surface morphology to provide the antibacterial property. Surface morphology of coated ceramic surfaces was examined by SEM in detail and water contact angles were measured with goniometer. The relationships between antibacterial effect, phase evolution, surface topography, and wettability of surfaces were determined. The tenorite phase of CuO was observed on both Cu- and CuO-modified surfaces. Both Cu and CuO particles in glazed ceramic surfaces showed the similar antibacterial activity against Staphylococcus aureus and Escherichia coli. The antibacterial activity was dependent on mainly tenorite phase crystallization. The amount of the tenorite phase that was slightly higher in the case of Cu-incorporated surfaces instead of CuO and hence the bactericidal effect was slightly more pronounced. Although the developed surfaces are not hydrophobic, they show antibacterial properties.     

Real time selection of scheduling rules and knowledge extraction via dynamically controlled data mining

A new scheduling system for selecting dispatching rules in real time is developed by combining the techniques of simulation, data mining, and statistical process control charts. The proposed scheduling system extracts knowledge from data coming from the manufacturing environment by constructing a decision tree, and selects a dispatching rule from the tree for each scheduling period. In addition, the system utilises the process control charts to monitor the performance of the decision tree and dynamically updates this decision tree whenever the manufacturing conditions change. This gives the proposed system the ability to adapt itself to changes in the manufacturing environment and improve the quality of its decisions. We implement the proposed system on a job shop problem, with the objective of minimising average tardiness, to evaluate its performance. Simulation results indicate that the performance of the proposed system is considerably better than other simulation-based single-pass and multi-pass scheduling algorithms available in the literature. We also illustrate knowledge extraction by presenting a sample decision tree from our experiments.     

Influence of Micro- and Nanonatural Fillers on Mechanical and Physical Properties of Foamed SMA Composites

This study is to investigate the reinforcing effects of fillers on mechanical and physical properties of foamed styrene-maleic anhydride (SMA) composites. According to the results, the best foaming was determined for starch reinforced SMA composite. The best result of expansion ratio was found as 22.75% to SMA/starch composites. Stereo light microscopy results demonstrated that the foamed cell distribution is heterogeneous and composed of two sections. The minimum density was found as 0.64 g/cm³ for foamed SMA/starch composites. Mechanical properties of all foamed composites were found to be low as compared to neat SMA composite.     

The evaluation of procedures for dyeing silk with buckthorn and walloon oak on the basis of colour changes and fastness characteristics

In this study, silk fabric samples were dyed according to various procedures with buckthorn (Rhamnus petiolaris Boiss) and walloon oak (Quercus ithaburensis Decaisne) extracts. Reversed‐phase high‐performance liquid chromatography with diode‐array detection was utilised for the identification of dyes present in the dyed silk fabrics and the plant extracts. The extraction of dyes was carried out with a hydrochloric acid/methanol/water (2:1:1; v/v/v) mixture. The colour coordinates of the silk fabrics were measured, and the rubbing, wash and light fastness properties of the dyed silk materials were determined and are discussed.     

Shelf-life of infrared dry-roasted almonds

Infrared heating was recently used to develop a more efficient roasting technology than traditional hot air roasting. Therefore, in this study, we evaluated the shelf-life of almonds roasted with three different approaches, namely infrared (IR), sequential infrared and hot air (SIRHA) and regular hot air (HA). Nine medium roasted almond samples produced by the aforementioned heating methods were processed at three different temperatures (130, 140 and 150 °C), packed in paper bags and then stored at 37 °C for three, six or eight months. Shelf-life of the roasted almonds was determined by measuring the changes in colour, peroxide value, moisture content, water activity, volatile components and sensory quality. No significant difference was observed in moisture content and water activity among the almond samples processed with different roasting methods and stored under the same conditions. GC/MS analysis showed that aldehydes, alcohols, and pyrazines were the main volatile components of almonds. Aliphatic aldehydes such as hexanal, (E)-2-octenal, and nonanal were produced as off-odours during storage. Although the overall quality of roasted almonds produced with SIRHA and HA heating was similar during the first three months of storage, their peroxide value and concentration of aliphatic aldehydes differed significantly for different roasting methods and increased significantly in all roasted samples during storage. We postulate that hexanal and nonanal might be better indicators of the shelf life of roasted almonds than the current standard, peroxide value.     

Infrared pasteurization of raw almonds

Due to outbreaks of salmonellosis associated with whole raw almonds, an infrared (IR) pasteurization process was investigated for its efficacy in improving the safety of raw almonds. After almonds were heated to 100, 110 and 120 °C with IR, they were cooled at ambient temperature to a holding temperature of 70, 80 or 90 °C before being transferred to a custom-designed holding device for different time periods up to 60 min. We observed that holding almonds at 90 °C for 10-15 min reduced the Pediococcus population size by more than 5-log and holding at 80 °C for longer than 22 min provided more than 4-log reduction, thus satisfying the targeted 4-log reduction required in the almond industry. The L^∗a^∗b^∗ color values of whole almonds were not affected significantly (P > 0.05) by the IR process whereas the a^∗ and b^∗ color values of ground almonds changed significantly (P < 0.05). The sensory panel did not detect any significant difference (P > 0.01) in appearance, texture, flavor and overall quality of pasteurized almonds compared with untreated samples.     

The Genus Heracleum: A Comprehensive Review on Its Phytochemistry,Pharmacology, and Ethnobotanical Values as a Useful Herb

Heracleum species, also known as hogweed, are traditionally used as food additives, spices, and flavoring agents. Moreover, these plants are widely used in folklore medicine for the treatment of many disorders such as inflammation, flatulence, stomachache, epilepsy, psoriasis, and as carminative, wound healing, antiseptic, antidiarrheal, tonic, digestive, pain killer, analgesic, and anticonvulsant agents. The genus Heracleum has broad pharmacological activities: anti‐inflammatory, antimicrobial, anticholinesterase, anti‐oxidant, antiviral, cytotoxic, and anticarcinogenic. A total of 94 compounds have been isolated from plants of the Heracleum genus, all indicating vital biological activities. Also, about 50 compounds have been identified as major components in their essential oils. The genus is rich in several types of bioactive coumarin compounds, with huge potential for the discovery of new coumarins. Various parts of these plants produce essential oils (mainly aliphatic esters and monoterpenes) with a wide spectrum of biological activities. Heracleum species have great potential for applications in the food, cosmetics, perfumery, and pharmaceutical industries due to their broad ethnobotanical uses and pharmacological properties. Accordingly, this review aims to categorize updated and comprehensive information on ethnobotanical uses, phytochemistry, and pharmacology of Heracleum species in order to open new perspectives for future studies, including possible uses as functional ingredients in food products.