Supercriticial fluid extraction of flavors and fragrances from Hyssopus officinalis L. cultivated in Iran

Hyssopus officinalis L. (hyssop) as a food ingredient has its own importance in flavor industry and also in sauce formulations. Supercritical fluid extraction (SFE) of hyssop, cultivated in Iran, was performed at various pressures, temperatures, extraction (dynamic and static) times and modifier (methanol) concentrations using an orthogonal array design with an OA₂₅(5⁵) matrix conditions. Pressure, temperature and modifier in the SFE system influenced the extraction yield. Also, the composition of the extracted oils was greatly impacted by the operating conditions. Main components of the extracts under different SFE conditions were sabinene (4.2–17.1%, w/w), iso-pinocamphene (0.9–16.5%) and pinocamphene (0.7–13.6%). The extraction of sabinene, for example, was favored at 100 atm, 55 °C, 1.5% (v/v) methanol, 30 min dynamic time and 35 min static time. Use of SFE under different conditions can allow targeting the extraction of different constituents.     

Supercritical CO2 and highly selective aromatase inhibitors: Experimental solubility and empirical data correlation

The solubility of highly selective and potent third-generation aromatase inhibitors includes the non-steroidal agents letrozole and anastrozole and the steroid exemestane in supercritical carbon dioxide (SC-CO₂) has been investigated. The experiments were carried out using the simple and static method at pressures in the range of 12.1–35.5 MPa and temperatures ranging from 308 to 348 K. The mole fraction solubilities ranged from 0.22 × 10⁻⁵ to 1.88 × 10⁻⁴. Solubility data were correlated using six empirical models (Chrastil model, dV–A model, K–J model, Bartle model, Yu model and Gordillo model). The results showed that these models can be applied to satisfactory solubility predictions at different pressures and temperatures. A comparison among the six models revealed that the K–J, and Gordillo models gave much better correlations of the solubility data with an average absolute relative deviation (AARD%) ranging from 0.2 to 2.3 and from 1.6 to 2.5%, respectively. Using the correlation results, the heat of drug–CO₂ solvation and that of drug vaporization was separately approximated in the range of −17.3 to −17.5 and 93.0–112.1 kJ mol⁻¹.     

Thermal and mass transport properties of polyester–cotton plated fabrics in relation to back layer fibre profiles and face layer yarn types

Clothing plays an important role in maintaining thermal equilibrium between a human body and the ambient environment by serving as a medium for heat, moisture vapour and liquid moisture transfer. The ability of fabric to maintain this equilibrium is related to thermo-physiological comfort. Plating is an innovative knitted fabric production technique to obtain bi-layered fabrics. An attempt has been made to engineer plated knit structures with such a combination of fibre cross section in the back (inner/next to skin) and the yarn type in the face (outer) layer, so that a rapid liquid transfer from back layer by wicking and quick liquid absorption and evaporation by the face layer can be achieved. Plated fabrics using the combination of triangular polyester fibre in the back and carded cotton yarn in the face layer showed the higher thermal resistance, higher absorbent capacity and would be warmer to the initial touch. However, the combination of combed cotton yarn with triangular polyester fibre resulted in fabrics with the higher air permeability, moisture vapour transmission rate and transplanar wicking.     

Electrolytic reduction improves treatability of humic acids containing water streams

BACKGROUND: An understanding of the structure of humic acids is essential for their degradation or physical removal from wastewaters. This work aims at targeting the reactivity of these molecules by modifying their properties. Structural alterations were carried out by electrolytically reducing the solution containing humic acid in an electrolytic cell to convert them into less polar structures. RESULTS: Overall it was observed that electrolytic reduction of humic acids strongly facilitated their further treatability. First, the reduced forms of humic acids exhibited improved adsorption on activated carbon. For 1 kW h of electrical energy consumed during electrolytic reduction, the additional chemical oxygen demand (COD) adsorbed was 60 g for a synthetic humic acid solution. Similarly, the additional COD adsorbed (kW h)^?1 was found to be 35 g and 112 g for humic acid‐rich effluent and landfill leachate, respectively. In comparison with non‐reduced control samples, a 200‐fold decrease in the chloroform formation was observed when electrolytically reduced drinking water samples were supplemented with a chlorine dosage of 150 mg L^?1. Moreover, an enhanced membrane flux was obtained with electrically reduced samples, indicating their improved membrane filterability. CONCLUSION: The electrolyzed humus species were characterized by analyzing their surface tension and particle size. This work addresses an alternative technology for the treatment of water streams containing humic acids. Copyright © 2007 Society of Chemical Industry     

Evaluation of some essential oils as botanical fungitoxicants for the protection of stored food commodities from fungal infestation

Essential oils from different parts of 18 plants belonging to 11 families were extracted and tested against two toxigenic strains of Aspergillus flavus Link through the poisoned food technique. The oil of Mentha arvensis was found to be effective against both strains of A. flavus and completely stopped the radial mycelial growth of A. flavus at 0.10 mg mL^?1. It was found to be superior over the synthetic fungicides tested and showed a broad fungitoxic spectrum against A. niger, A. fumigatus, Botryodiplodia theobromae, Cladosporium cladosporioides, Fusarium oxysporum, Helminthosporium oryzae, Macrophomina phaseolina and Sclerotium rolfsii at 0.10 mg mL^?1. The oil completely inhibited the aflatoxin B1 production by the toxigenic strain of A. flavus at 0.05 mg mL^?1. Moreover, the Mentha oil also exhibited potent antioxidant activity in 2,2′‐azino‐bis‐3‐ethylbenzothiazoline‐6‐sulphuric acid (ABTS) bioassay. Keeping in mind the side effects of synthetic pesticides and the global interest in botanical pesticides for plant protection due to their biodegradable nature, M. arvensis oil may be used as a botanical fungitoxicant against fungal attack to stored food commodities. The antiaflatoxigenic and antioxidant nature of the oil suggest the possibility of its exploitation for enhancing the shelf life of stored food commodities. Copyright © 2007 Society of Chemical Industry     

A survey on nature-inspired techniques for computation offloading and service placement in emerging edge technologies

World Wide Web - Internet of Things (IoT) aims to make an environment more innovative and productive by connecting physical things to the internet. Processing generated data from IoT devices and...     

Relationship between mechanical properties of and crack progogation in epoxy resin adhesives

Crack propagation in a series of amine-cured epoxy resin adhesives in both the bulk material and adhesive joints has been studied as a function of the formulation of the resins and the conditions of testing using a linear elastic fracture mechanics approach. In both cases propagation was found to take place in either a stick—slip (unstable) or a continuous (stable) manner; the particular type of propagation depending upon the amount and type of hardener used and the temperature and rate of testing. A constant crack opening displacement (δ) has been shown to be a unique failure criterion for continuous propagation with δ having approximately the same value in both bulk material and joints. However δ was found to increase in the stick—slip mode of propagation. These crack propagation characteristics have been related to the compressive yield behaviour of each material as determined by uniaxial compression tests performed on the epoxy resins. Possible mechanisms of crack propagation have also been discussed.     

Stability of crack propagation in epoxy resins

The propagation of cracks in epoxy resins has been studied using a linear elastic fracture mechanics approach and a double torsion testing geometry. Under constant crosshead displacement rate conditions cracks are found to propagate in an unstable ‘stick-slip’ manner at high temperatures and with low rates of testing whereas at lower temperatures and using higher rates of loading propagation is more stable and cracks propagate in a continuous manner. The presence of liquid water tends to cause a transition from stable to unstable propagation at room temperature. The influence of specimen geometry upon crack stability is also discussed.