OPTIMAL ROBUST DESIGN OF NOVEL MATERIALS: PROBLEMS OF STABILITY AND VIBRATIONS

A numerical method for the optimal design of thin anisotropic laminates is presented, layer thicknesses and lamination angles being the design variables. An optimal solution is pursued with respect to frequency domain objectives, e.g. fundamental frequency and Euler critical load. A special feature of the method is the semi-analytical second order design sensitivity that is computed with the aid of a Rayleigh-Ritz analysis approach. A modified sequential quadratic programming scheme is then introduced, where standard quasi-Newton approximations are avoided by an exact calculation of the Hessian matrix. Furthermore, the robustness of the method with respect to scatter in material properties such as mass density and elastic moduli is assessed. A stochastic extension of the Rayleigh-Ritz approach is developed on this purpose that allows the location of those regions in the design space that are most sensitive to physical parameter randomness. This allows the use of a modified objective function that penalizes sensitive solution.     

NMR assessment of water uptake in different Vigna spp. seeds

Water uptake in seeds of ten wild and cultivated Vigna spp. accessions was investigated by NMR Spectroscopy. Water absorbed by the intact seeds was measured at intervals by changes in unabsorbed water using analysis of transverse magnetization decay of water protons. Widely different hydration kinetics of first and higher orders were found amongst the samples. the time required to reach saturation hydration capacity ranged from 3 to 16 h; total amount of absorbed water varied from 1.06 to 1.39g H₂O g⁻¹ sample and kinetic constant from 8.2 to 20.4 10⁻³ min⁻¹.
Accessions with a rough seed coat showed a fast water uptake within the first hour while some accessions smooth seed coat need an activation period of 1–5h.
No significant relationships were found between kinetic constant, absorbed water and protein content or some morphological characteristics (100 seed mass, length/width, width/thickness).
Wild species did not absorb water for days, an attribute related to biological survival, but after dehulling they absorbed water at similar rates to the cultivated cowpeas.
NMR can be a suitable technique to investigate some technological characteristics of legumes related to domestic and industrial processing (cooking, canning). It has potential to give data on the various forms of free and bound water, although this was not fully derived in the present work.     

Asbestos fibres detected by scanning electron microscopy in the gallbladder of patients with malignant pleural mesothelioma (MPM)

Gallbladders from patients affected by both malignant pleural mesothelioma (MPM) and important gallbladder disorders were analyzed to verify the presence of asbestos fibres. Histological thin sections were analyzed by optical microscope and variable pressure scanning electron microscopy coupled with energy dispersive spectroscopy, allowing morphological and chemical characterization of each inorganic phase observed. Fibres of chrysotile and crocidolite, minerals regulated as asbestos, were identified. By immunohistochemical analysis, connective tissue was recognized as the incorporation site. These findings confirm that asbestos fibres can reach the gallbladders of patients with MPM, for whom the development of respiratory diseases confirms asbestos exposure.     

Esters of 1,3,3,-trimethyl-2-oxabicyclo [2.2.2]octan-6-ols: synthesis, odour evaluation and in vitro preliminary toxicity assays

The synthesis of a series of alkyl and arylesters of 1,3,3,-trimethyl-2-oxabicyclo[2.2.2]octan-6-ols (2-cineolylols) is described. All cineole esters obtained were tested for their olfactive character; the esters derived from aryl acyl chlorides were odourless, while aliphatic esters showed interesting multipurpose aromas. Some of these compounds exhibited fruity, woody, green, pine oil and violet-like notes and some showed aromas interesting for foodstuffs. In vitro toxicity tests were carried out on the cyclopropyl ester of 2-cineolylols, the most promising of these compounds as a potential perfume ingredient. In this study, cultured mouse fibroblast L-929 and human keratinocyte NCTC 2544 cell lines were used. The results obtained with the evaluation of three different physiological end points showed that the tested compound possess much lower cytotoxicity than sodium dodecylsulphate (SDS) used as positive control     

Use of a Bovine Heme Iron Concentrate in the Fortification of Biscuits

Biscuits were fortified with 4, 6, 8, and 10% heme iron concentrate (HIC). The 10% fortification level presented problems of poor dough quality. The 4, 6, and 8% levels were evaluated for appearance, flavor, texture, taste and aroma and 6% was chosen as the appropriate fortification level. Protein of the fortified biscuit was 1.6 times higher and iron 8 times higher than that of the unfortified control. A shelf life study showed that at 40°C, lipid peroxidation of the biscuits was considerably higher than at room temperature and a catalytic effect of the HIC on the lipid autooxidation was observed. Under controlled conditions, the biscuits could be satisfactorily stored up to 7 months. The fortification of biscuits with HIC represents an interesting alternative for the prevention of iron deficiency.     

EFFECT OF CARAMELIZATION AND MAILLARD REACTION PRODUCTS ON PEROXIDASE ACTIVITY

Solutions of D-fructose and sucrose were heated, alone and in the presence of glycine. The reaction products were examined in terms of their effects on peroxidase (POD) activity. Compared with glucose mixtures, fructose products had a great inhibiting effect on POD activity, while in the case of Maillard reaction products (MRPs), the differences in antibrowning activity between fructose-glycine and glucose-glycine mixtures were slight. As regards the sucrose and sucrose-glycine solutions, a slight inhibiting effect on POD activity was observed only after sugar hydrolysis. Measurements of the reducing power of sugar and sugar-amino acid solutions showed a correspondence between antioxidant properties of caramelization and Maillard reaction products and their antibrowning effects.     

Synthesis of quaternary ammonium bromides of 5-[4-(ω-dialkylaminoalkoxy)phenyl-methylene]-1, 3, 3-trimethyl-2-oxabicyclo [2.2.2]octan-6-ones as potential UV sunscreens

Materials and methods for the synthesis of eight quaternary ammonium bromides of 5-[4-(ω-dialkylaminoalkoxy)phenylmethylene]-1,3,-trimethyl-2-oxabicyclo[2.2.2]octan-6-ones are illustrated. They were routinely prepared starting from cineole aminoethers by reaction with primary alkyl bromides and their physico-chemical data are reported. These substances have been tested for UV filtering and/or microbiological activity. The substances have their UV absorption maxima at 315–322 nm. Tests on antimicrobial activity were performed using benzalkonium chloride as reference standard. All quaternary ammonium bromides were totally inactive against Escherichia coli (Gram —) and partially active on Staphylococcus aureus (Gram +). These preliminary findings seem to indicate that these new quaternary ammonium bromides could be considered as potential UV sunscreens.     

Crystallographic preferred orientation (CPO) of gypsum measured by electron backscatter diffraction (EBSD)

An investigation by electron backscatter diffraction on gypsum shows that this technique can be used to study the microstructures and crystallographic preferred orientation of gypsum. Presented here are the methods, verification tests and data obtained from a naturally deformed sample of gypsum‐rich rock. The electron backscatter diffraction data show the sample has a strong crystallographic preferred orientation.     

Shelf life of ice-stored redfish, Sebastes marinus and S. mentella

Redfish ( Sebastes marinus and S. mentella ) were caught by an Icelandic trawler, stored at about 0°C in boxes in the hold and landed in a German fishing harbour. Boxed redfish, differing in storage time on board, were subsequently stored in melting ice in the chill store of the laboratory at a temperature of +4°C until the borderline of saleability was reached. the quality loss of the ice-stored redfish was monitored by a number of chemical, physical and microbiological parameters including volatile base nitrogen (TVB-N), trimethylamine (TMA), trimethylamine oxide (TMAO), creatine, ethanol, Fishtester readings and number of cfu. AH parameters were correlated with sensory analysis and time in ice.
The rate of deterioration of iced redfish depended on the conditions of storage. Sensory analysis was the most accurate indicator of the limit of saleability of redfish. Iced redfish, stored mainly in a chill store (4–5°C) onshore, had a shelf-life of 16 to 19 days from catching. Fish stored at 0.5°C in the hold of the fishing vessel had a shelf-life of 22 days: These results reflect the different storage temperatures and the effects of handling, transport and storage damage on the quality of the fish. the Fishtester proved to be very useful for the determination of deterioration. Measuring ethanol, TVB-N and TMA gave no information about quality changes during the first 12 days of storage.     

HEAVY METALS AND OPTICAL WHITENINGS AS QUALITY PARAMETERS OF RECYCLED PAPER FOR FOOD PACKAGING

The aim of the present work was to evaluate the suitability of recycling papers for their possible use in the field of food packaging. Therefore, the amount of some heavy metals (Pb, Cd, Cr, Cr VI, Hg) and the presence/migration of optical whitenings in 14 samples of recycled papers was determined.