Effects of Mica, Carnauba Wax, Glycerol, and Sodium Caseinate Concentrations on Water Vapor Barrier and Mechanical Properties of Coated Paper

ABSTRACT: The combined effects of mica (0% to 1.2% [w/w]), carnauba wax (0% to 0.8% [w/w]), glycerol (0% to 6% [w/w]), and sodium caseinate (10% to 13% [w/w]) concentrations on water vapor barrier and mechanical properties of coated paper were studied. A Doehlert matrice was used to investigate the main effects of these factors and their different interactions. The results were analyzed using the response surface methodology. Carnauba wax and glycerol concentrations were the most important parameters affecting water vapor permeability (WVP). Glycerol enhanced WVP as its concentration increased. Carnauba wax and mica factors decreased WVP of coated paper. Conversely, increasing the amount of glycerol led to a decrease in tensile strength (TS) and to an increase in elongation (%E) of the resulting coated papers.     

Rapid Quantification Method of Three <Emphasis Type="Italic">Alternaria</Emphasis> Mycotoxins in Strawberries

Validation of simple and rapid method for three Alternaria mycotoxins determination including alternariol (AOH), alternariol methyl ether (AME) and tentoxin (TEN) in strawberries is described. The extraction procedure was based on a simple liquid–liquid extraction with ethyl acetate, which provided the highest recoveries and the lowest matrix effect. Analytes were determinated by liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS). The obtained relative recoveries were higher than 63 % for the studied mycotoxins in strawberries at the limit of quantification (LQ). Good linearity (r ²?>?0.993) and quantification limits (3–14 ng/g) were obtained. Repeatability, expressed as relative standard deviation, was always lower than 6 %, whereas interday precision was lower than 13 % for the developed method. The method was applied to analyse 24 strawberry samples commercialized in markets of the Valencia city (Spain). Analysed samples were only contaminated with AOH and AME.     

Contribution of surface treatments by esterification and silanization in reinforcing the composites based on Pine cone and Spartium junceum flours and polypropylene

Pine cone and Spartium junceum are readily available cellulosic materials which can be used as reinforcements in thermoplastic-based composites. In the present study, flours issued from Pine cone (PCF) and Spartium junceum (SjF) were first chemically modified with maleic anhydride (MA) and silane. Then, neat and treated flours were incorporated into a polypropylene (PP) matrix and the properties of composites prepared without or with maleic anhydride-grafted-polypropylene (PP-g-MA), added as a compatibilizer, were compared. FTIR analysis proved the efficiency of the treatments in removing some non-cellulosic components and formation of ester linkages due to the reaction between MA and the flours hydroxyl groups. In the case of Silane-PCF, the bands observed around 1730?cm^?1 and 1241?cm^?1 disappeared, thus indicating that the silane treatment allowed the extraction of hemicellulose and lignin from the flour surface. X-rays diffraction results showed that the applied chemical treatments contributed in increasing the flours crystallinity index, which implies that by the removal of the amorphous material covering the fibers, the more crystalline cellulosic component of the fibers is exposed. The incorporation of PCF and SjF increased the composites crystallinity which emphasizes their significant role in heterogeneous nucleating of PP matrix. Additionally, the composites observation by electron microscopy revealed more intimate contact between the flours and PP matrix after surface modification which permitted the dissolution of impurities. As a result, treated PCF and SjF induced a significant increase in the composites resilience and decreased notably their water uptake aptitude relatively to the composites based on untreated flours.     

Alginate coatings containing grapefruit essential oil or grapefruit seed extract for grapes preservation

Biodegradable coatings based on 1% and 2% sodium alginate (NaAlg) with and without grapefruit seed extract (GSE) or grapefruit essential oil (GEO) were applied to table grapes to preserve their quality. Changes in weight loss, firmness and antioxidant activity were assessed over 15 days of cold storage. The effectiveness of developed coatings to control postharvest decay of inoculated grape berries stored for 5 days at 20 °C was also investigated. Biodegradable coatings based on pure NaAlg and those containing GSE were efficient in reducing weight loss and maintaining firmness during storage. Coatings incorporating either GEO or GSE were able to preserve the antioxidant activity of treated grapes and to reduce decay incidence in inoculated fruits. Coatings formulated with 2% NaAlg‐1% GSE showed the greatest preservation of antioxidant activity and the highest antifungal effect, with an effective control of water and firmness losses. These coatings can be recommended for maintaining table grapes quality.     

Preparation of Sb:SnO2 thin films and its effect on opto-electrical properties

The present study focuses on pure and antimony (Sb)-doped tin oxide thin film and its influence on their structural, optical, and electrical properties. Both undoped and Sb-doped SnO₂ thin films have been grown by using simple, inexpensive pyrolysis spray technique. The deposition temperature was optimized to 450 °C. X-ray diffractions pattern have revealed that the films are polycrystalline and have tetragonal rutile-type crystal structure. Undoped SnO₂ films grow along (110) preferred orientation, while the Sb-doped SnO₂ films grow along (200) direction. The size of Sb-doped tin oxide crystals changes from 26.3 to 58.0 nm when dopant concentration is changed from 5 to 25 wt%. The transmission spectra revealed that all the samples are transparent in the visible region, and the optical bandgap varies between 3.92 and 3.98 eV. SEM analysis shows that the surface morphology and grain size are affected by the doping rate. All the films exhibit a high transmittance in the visible region and show a sharp fundamental absorption edge at about 0.38–0.40 nm. The maximum electrical conductivity of 362.5 S/cm was obtained for the film doped with 5 wt% Sb. However, the carrier concentration is increased from 0.708?×?10¹⁸ to 4.058?×?10²⁰ cm³. The electrical study reveals that the films have n-type electrical conductivity and depend on Sb concentration. We observed a decrease in sheet resistance and resistivity with the increase in Sb dopant concentration. For the dopant concentration of 5 wt% of Sb in SnO₂, the Rs and ρ were found minimum with the values of 88.55 (Ω cm^?2) and 2.75 (Ω cm), respectively. We observed an increase in carrier concentration and a decrease in mobility with the addition of Sb up to 25 wt%. The highest figure of merit values 2.5?×?10^–3 Ω^?1 is obtained for the 5wt% Sb, which may be considered potential materials for solar cells' transparent windows.

     

The bi-objective two-dimensional loading vehicle routing problem with partial conflicts

The two-dimensional loading vehicle routing problem with partial conflicts combines two NP-hard problems: the classical vehicle routing problem and the two-dimensional bin-packing problem with partial conflicts. This new variant of transportation problems is inspired from hazardous materials classification and compatibilities, where some materials can be partially conflicting. In this case, they can be loaded together but an additional constraint on the distance separating them must be respected. We propose in this paper an NSGA-II algorithm to perform a bi-objective study in which the minimization of the total cost of transportation as well as the load balancing between different routes in terms of used area of vehicles are the considered objectives. The first results for this new problem are presented, using benchmarks available in the literature that have been adapted to deal with the problem. Moreover, the adding value of path relinking is proved with different statistical measurements.     

Adsorption of Cu(II) from industrial liquid waste on Na-bentonite and Al-PILC following a full factorial design

The paper reports a study of the performance of Maghnia bentonite in a purified and modified state for the removal of Cu(II) from industrial liquid waste in the region of Oran (North West Algeria). Bentonite was firstly treated to produce a Na-bentonite, then modified with an aluminum solution containing molar ratio OH/Al of 1.8 and finally calcined at 450 °C. The polymer [AlO₄Al₁₂(OH)₂₄(H₂O)₁₂]⁷⁺ formed in solution was adsorbed by surface complexation on the bentonite, which is known to have a high capacity to fix metal cations. The prepared materials were characterized by DRX, BET and EDX. In order to find the optimum conditions, a full factorial design of 2⁴ allowed us to determine the main effects and interactions of the factors studied: pH, mass of materials, contact time and temperature. The results obtained show that the best rate of adsorption of copper requires a pH = 10, a mass = 0.8 g, a stirring time = 80 min, and a temperature = 25 °C. The adsorption capacity of treated bentonite increased considerably from 4.147 mg/g for Na-bentonite to 7.173 mg/g for pillared aluminum bentonite. This shows the strong adsorption of copper compared with Na-bentonite, caused by its high surface area.