Development of decision support system for fastener selection in product recovery oriented design

Among the important strategies in sustainable product development is by maintaining product recovery and prolonging product life which are highly dependent on the ease of disassembly. When considering the design for disassembly, there are many fastener-associated factors to be considered such as structural, disassembly process and the pre-disassembly process. There are very few designs for disassembly methods that support the selection of fasteners for design for disassembly (DfD) concepts. Most of the tools developed are more applicable during later stages of the design process when more product information is available. The process of selecting a fastener for its functional characteristics itself is often vague. Additionally, the requirements for disassemblability further complicate the process. This paper proposes the development of a multi-criteria decision making model to assist designers in selecting fasteners for DfD. PROMETHEE was used to build a decision-making model to help the designers in selecting the fasteners that could perform their intended functions with ease of disassembly. A design case study is described to reflect the usefulness of the fasteners selection model.     

Microwave-Assisted Bleaching of Wool Fabrics

Microwave irradiation was used to reduce consumption of energy and time during bleaching of wool fabrics with hydrogen peroxide. The effect of some reaction conditions; viz. hydrogen peroxide concentration, treatment time, presence of stabilizer, on degree of whiteness imparted to bleached wool, was studied systematically. Comparative study between bleaching of wool using microwave irradiation and conventional heating was undergone. The effect of bleaching of wool on its morphological structure was assigned by scanning electron microscopy. The change in some chemical and physicomechanical characteristics of bleached wool was monitored; namely whiteness index, alkali solubility, wettability, critical surface area, tensile strength, and elongation at break, of the treated as well as untreated fabrics were measured. The microwave-assisted bleaching of wool resulted in improved degree of whiteness comparable to that is obtained using conventional heating method. However, the microwave-assisted bleached wool shows lower degree of deterioration than that of conventionally bleached wool. The COD and BOD of the wool bleaching effluents were determined.     

Occurrence of deoxynivalenol in durum wheat in Tunisia

Wheat is frequently contaminated by the deoxynivalenol (DON) which is a member of the trichotecene family, the most important group of mycotoxins produced by the Fusarium moulds. As Tunisian population is a big consumer of cereals mainly durum wheat, human exposure to DON can be, consequently high. This survey was performed to study the occurrence of DON in Tunisian durum wheat area during the crop of 2007. A total of 65 samples of durum wheat from five cultivating locations in the North of Tunisia, the major cropping area, were analysed. To detect and to quantify the mycotoxin DON, an efficient HPLC/UV method was developed, including immunoaffinity step for DON extraction from durum wheat followed by liquid chromatography (LC) for quantification. As DON is a water soluble toxin, the extraction procedure from wheat samples was performed using water. Samples were centrifuged then passed through the immunoaffinity columns. After column’s washing, the toxin was slowly eluted by methanol. Wheat sample extracts were injected to the LC system set at a wavelength of 220 nm. From 65 samples, 83% showed DON contamination with averages ranging from 12.8 ± 5% to 30.5 ± 13.3% μg/g exceeding the maximum permitted limit of 1.75 μg/g set by the European Commission in wheat.     

Comparison of Estimation Capabilities of the Artificial Neural Network with the Wavelet Neural Network in Lipase-Catalyzed Synthesis of Triethanolamine-Based Esterquats Cationic Surfactant

In this study, estimation capabilities of the artificial neural network (ANN) and the wavelet neural network (WNN) based on genetic algorithm were investigated in a synthesis process. An enzymatic reaction catalyzed by Novozym 435 was selected as the model synthesis process. The conversion of enzymatic reaction was investigated as a response of five independent variables; enzyme amount, reaction time, reaction temperature, substrates molar ratio and agitation speed in conjunction with an experimental design. After training of the artificial neurons in ANN and WNN, using the data of 30 experimental points, the products were used for estimation of the response of the 18 experimental points. Estimated responses were compared with the experimentally determined responses and prediction capabilities of ANN and WNN were determined. Performance assessment indicated that the WNN model possessed superior predictive ability than the ANN model, since a very close agreement between the experimental and the predicted values was obtained.     

Novel interpenetrating amphiphilic Co‐networks based on compatibilized NBR/SBR‐montmorillonite composites: A study on the oil absorption characteristics

This work explores the fabrication of novel amphiphilic interpenetrating co‐network structures that may afford a reasonable solution to the problem of oil spills. It depends upon compatibilization of the binary immiscible rubber blend, containing the polar acrylonitrile–butadiene rubber and the non‐polar styrene–butadiene rubber. The compatibilization process was accomplished successfully using organic‐inorganic hybrid structures based on montmorillonites, priory treated with a hydrophobic cationic agent to different levels so that they acquire wide range of amphiphilicity. With achieving the goal of compatibilization using bi‐polar montmorillonites, the formed amphiphilic interpenetrating network structures are thought to qualify as oil absorbent materials for oils exhibiting a broad spectrum of hydrophilicity/hydrophobicity. For this purpose, toluene, which exhibits both polar and non‐polar characters, was chosen as model to predict the oil absorption and swelling extent as a function of the clay philicity. The capacity of oil uptake showed good correlation to the cross‐linking density. The combination of both polar and non‐polar moieties in polymer structures used as oil absorptive materials provides a good tool to control the properties of the resulting materials supposing that the polarity and/or content of the inserted clay are the key variables: toughness offers buoyancy, stability, and easy recovery of absorbed oils irrespective of their polarity. Furthermore, the recovered oil‐swelled materials are suitable for regular oil‐refining processes (economic, no waste, green approach). The developed materials in this work are additionally advantageous because of cost‐effective concerns with respect to other developed materials in recent years in particular in the presence of the clay as one of the main constituents of these structures. This approach can reduce the environmental impacts from oil spills and help recover one of most precious natural resources. POLYM. COMPOS., 36:1494–1501, 2015. © 2014 Society of Plastics Engineers     

Filtration in hydrophobic media: 2. A triglyceride partition phenomenon as observed by tangential filtration of butter oil

Having demonstrated a partition of a hydrophobic medium (butter oil) under crossflow filtration and having tentatively explained the phenomenon on stereochemical and saturation basis, the molecular partition was studied by tangential filtration. Under specific hydrodynamic conditions, a filtration phenomenon was demonstrated. The solid fat content (SFC) at 20°C of the fractions obtained was investigated accordingly. When the molecular partition takes place, an SFC divergency between the permeate and the retentate is observed. The amplitude of the divergency depends on experimental conditions.     

Ultrastructure of low-fat ground beef patties with added whey protein concentrate

Microstructure of gels formed at 71°C from different mixtures of beef myofibril protein (BMP; 6.1% protein) and whey protein (WP) were studied by transmission electron microscopy (TEM). At a ratio of30:10 (w/w) of whey protein concentrate (WPC; 79.5% protein) to BMP, WP formed a network of aggregated clusters in which beef myofibril proteins were embedded. WP apparently acts as a filler and possibly as a cementing agent for the meat pieces. At a lower ratio of 10:30 (wl w), the WP aggregates occupied and increased the interstitial spaces between the myofibril protein and reinforced the network. The location of WP in the interstitial spaces might explain its water binding ability in beef patties formulated with WP and water. WP protected the beef myofibril protein structure during heating as less disintegration in the Z-line was observed in gels with WP compared to the control. Low-fat (10% fat) ground beef patties with added 10% water and 1–4% whey protein concentrate (WPC), cooked to three different internal temperatures (60, 70 and 80°C), were evaluated for their cooking characteristics and examined by TEM. For all levels of addition, WPC improved the cooking yield compared to a non-formulated control of 10% fat. Fat retention was also improved at the highest level of WPC addition. The increased cooking yield was shown to be caused principally by the better water retention. The textural parameters, hardness and chewiness, were not affected by WPC addition but increased with increasing cooking temperature. These temperature-induced changes were matched by marked changes to the ultrastructure of the meat products.     

A review of bread qualities and current strategies for bread bioprotection: Flavor,sensory, rheological,and textural attributes

The unequivocal economical and social values of bread as a staple food commodity lead to constant interests in optimizing its postproduction quality and extending its shelf life, which is related to the maintenance and enhancement of flavors and textural properties, and finally, to the delay of microbial spoilage. The latter has been the subject of a multitude of studies and reviews, in which the different approaches and views were discussed. However, variations in bread freshness, flavor, and textural quality are still of concerns for the bread making industry, in conjunction with the expectation from consumers for bread products with high-quality attributes and free of synthetic ingredients that satisfy their pleasure and their sustainable lifestyle. This review mainly focuses on the quality profiles of bread, including flavor, rheological, textural, and sensorial aspects; on the modalities to assess them; as well as on the conventional and emerging approaches developed so far over the past decades. The applications of lactic acid bacteria (LAB) and enzymes as bioprotective technologies are examined and discussed, along with active packaging and novel processing technologies for either the maintenance or improvement of bread qualities during storage.     

The behaviour of Arabian donkey milk during acidification compared to bovine milk

To better understand the fermentation kinetic of Arabian donkey milk, its physicochemical properties, conductivity and viscosity were assessed during acidification, and compared to that of the bovine milk. Donkey milk showed a shorter latency phase and slightly lower acidification rate than bovine milk. Measurement of electric conductivity during acidification showed that maximum demineralisation of casein micelles occurred at around pH_I 5.44 for donkey milk and pH_I 5.16 for bovine milk. Donkey milk was also found to be less viscous. The technological characteristics of donkey milk were different from those of bovine milk due to intrinsic physicochemical properties of both milks.     

Crystallization behaviour and hardness of glass ceramics rich in nanocrystals of ZrO2

This research is mainly directed toward the development of hardness of glass ceramic by adding different amounts of ZrO₂ to the glass and by applying different heat-treatments. Differential thermal analysis (DTA), X-ray diffraction (XRD) and Scanning electron microscope (SEM) were used to study the crystallization behaviour of the glass samples. The only observed crystalline phases were tetragonal and monoclinic zirconia. Hardness was found to increase by increasing time and temperature of heat-treatment due to the formation of monoclinic phase as a result of the martensitic reaction. This transformation opposes crack opening.