Effect of peel and seed removal on the nutritional value and antioxidant activity of tomato (Lycopersicon esculentum L.) fruits

The effect of peel and seed removal, two commonly practiced procedures either at home or by the processing industry, on the physicochemical properties, bioactive compounds contents and antioxidant capacity of tomato fruits of four typical Portuguese cultivars (cereja, chucha, rama and redondo) were appraised. Both procedures caused significant nutritional and antioxidant activity losses in fruits of every cultivar. In general, peeling was more detrimental, since it caused a higher decrease in lycopene, bcarotene, ascorbic acid and phenolics contents (averages of 71%, 50%, 14%, and 32%, respectively) and significantly lowered the antioxidant capacity of the fruits (8% and 10%, using DPPH. and b-carotene linoleate model assays, correspondingly). Although seeds removal favored the increase of both color and sweetness, some bioactive compounds (11% of carotenoids and 24% of phenolics) as well as antioxidant capacity (5%) were loss. The studied cultivars were differently influenced by these procedures. The fruits most affected by peeling were those from redondo cultivar (-66% lycopene, -44% b-carotene, -26% ascorbic acid and -38% phenolics). Seeds removal, in turn, was more injurious for cereja tomatoes (-10% lycopene, -38% b-carotene, -25% ascorbic acid and -63% phenolics). Comparatively with the remaining ones, the rama fruits were less affected by the trimming procedures.

Effect of temperature on the shear strength of aluminium single lap bonded joints for high temperature applications

An experimental and numerical investigation into the shear strength behaviour of adhesive single lap joints (SLJs) was carried out in order to understand the effect of temperature on the joint strength. The adherend material used for the experimental tests was an aluminium alloy in the form of thin sheets, and the adhesive used was a high-strength high temperature epoxy. Tensile tests as a function of temperature were performed and numerical predictions based on the use of a bilinear cohesive damage model were obtained. It is shown that at temperatures below Tg, the lap shear strength of SLJs increased, while at temperatures above Tg, a drastic drop in the lap shear strength was observed. Comparison between the experimental and numerical maximum loads representing the strength of the joints shows a reasonably good agreement.

Adherend thickness effect on the tensile fracture toughness of a structural adhesive using an optical data acquisition method

Adhesive bonding is nowadays a serious candidate to replace methods such as fastening or riveting, because of attractive mechanical properties. As a result, adhesives are being increasingly used in industries such as the automotive, aerospace and construction. Thus, it is highly important to predict the strength of bonded joints to assess the feasibility of joining during the fabrication process of components (e.g. due to complex geometries) or for repairing purposes. This work studies the tensile behaviour of adhesive joints between aluminium adherends considering different values of adherend thickness (h) and the double-cantilever beam (DCB) test. The experimental work consists of the definition of the tensile fracture toughness (GIC) for the different joint configurations. A conventional fracture characterization method was used, together with a J-integral approach, that take into account the plasticity effects occurring in the adhesive layer. An optical measurement method is used for the evaluation of crack tip opening and adherends rotation at the crack tip during the test, supported by a Matlab® sub-routine for the automated extraction of these quantities. As output of this work, a comparative evaluation between bonded systems with different values of adherend thickness is carried out and complete fracture data is provided in tension for the subsequent strength prediction of joints with identical conditions.

Siderophore Production by Bacillus megaterium: Effect of Growth Phase and Cultural Conditions

Siderophore production by Bacillus megaterium was detected, in an iron-deficient culture medium, during the exponential growth phase, prior to the sporulation, in the presence of glucose; these results suggested that the onset of siderophore production did not require glucose depletion and was not related with the sporulation. The siderophore production by B. megaterium was affected by the carbon source used. The growth on glycerol promoted the very high siderophore production (1,182 μmol g−1 dry weight biomass); the opposite effect was observed in the presence of mannose (251 μmol g−1 dry weight biomass). The growth in the presence of fructose, galactose, glucose, lactose, maltose or sucrose, originated similar concentrations of siderophore (546–842 μmol g−1 dry weight biomass). Aeration had a positive effect on the production of siderophore. Incubation of B. megaterium under static conditions delayed and reduced the growth and the production of siderophore, compared with the incubation in stirred conditions.

Effect of Adherend Recessing on the Tensile Strength of Single Lap Joints

Bonded joints are gaining importance in many fields of manufacturing owing to a significant number of advantages to the traditional methods. The single lap joint (SLJ) is the most commonly used method. The use of material or geometric changes in SLJ reduces peel and shear peak stresses at the damage initiation sites. In this work, the effect of adherend recessing at the overlap edges on the tensile strength of SLJ, bonded with a brittle adhesive, was experimentally and numerically studied. The recess dimensions (length and depth) were optimized for different values of overlap length (LO), thus allowing the maximization of the joint’s strength by the reduction of peak stresses at the overlap edges. The effect of recessing was also investigated by a finite element (FE) analysis and cohesive zone modelling (CZM), which allowed characterizing the entire fracture process and provided joint strength predictions. For this purpose, a static FE analysis was performed in ABAQUS1 considering geometric nonlinearities. In the end, the experimental and FE results revealed the accuracy of the FE analysis in predicting the strength and also provided some design principles for the strength improvement of SLJ using a relatively simple and straightforward technique.

Nonlinear dynamics of the patient’s response to drug effect during general anesthesia

In today’s healthcare paradigm, optimal sedation during anesthesia plays an important role both in patient welfare and in the socio-economic context. For the closed-loop control of general anesthesia, two drugs have proven to have stable, rapid onset times: propofol and remifentanil. These drugs are related to their effect in the bispectral index, a measure of EEG signal. In this paper wavelet time–frequency analysis is used to extract useful information from the clinical signals, since they are time-varying and mark important changes in patient’s response to drug dose. Model based predictive control algorithms are employed to regulate the depth of sedation by manipulating these two drugs. The results of identification from real data and the simulation of the closed loop control performance suggest that the proposed approach can bring an improvement of 9% in overall robustness and may be suitable for clinical practice.

Effect of active components from Garlic on AGEs formation

Advanced glycation end-products are Maillard reaction products that are found in thermal processed food. This compounds are often referred as unhealthy for human diet, namely because of their capacity to form amino-acid dimers. There is a broad range of answers to get about how these products are formed, how they interact with the organism and how these reactions can be inhibited to prevent the referred effects. Some compounds from garlic are thought to be able to inhibit these reactions. This study using spectrophotometric, High Performance Liquid Chromatography-Tandem Mass Spectrometry (HPLC-MS/MS) and Fourier transformed infrared spectroscopy (FTIR) analysis, helps to understand better not only not only the effect of some compounds obtained from garlic, diallyl sulfide (DAS), diallyl disulfide (DADS) and diallyl trisulfide (DATS), on these AGEs production reaction, but also helped to understand better the reaction itself.