3,5-Diaryl-4-amino-1,2,4-triazole derivatives as effective corrosion inhibitors for mild steel in hydrochloric acid solution: Correlation between anti-corrosion activity and chemical structure

Protection of Metals and Physical Chemistry of Surfaces - The corrosion inhibition efficiency of newly synthesized 3,5-diaryl-4-amino-1,2,4-triazole derivatives was investigated for mild steel...     

Effect of different starter cultures on the biogenic amines production as a critical control point in fresh fermented sausages

The selection of critical control points is one of the most important steps in the design of a hazard analysis and critical control points system. In this study, the influence of starter culture inoculation on biogenic amine accumulation in fresh fermented sausage as critical control point was studied. The effect of three starter culture Lactobacillus plantarum plus Bifidobacterium lactis, L. plantarum plus Bifidobacterium bifidum or L. plantarum plus B. lactis and B. bifidum on amines production were investigated. Tyramine (TY), Cadaverine (CA), Putrescine (PU), Histamine (HIS) and Tryptamine (TR) contents increased during the fermentation and storage stage, and TY was the prevailing amine in the final product. Sausages produced by fermentation with starters, as compared to natural fermentation (control), had a lower amount of biogenic amine. A great reduction in biogenic amine content was achieved when Bifidobacterium sp. were inoculated, also levels of species of Enterobacteriaceae and Pseudomonas decreased, while lactic acid bacteria counts increased during fermentation and storage.     

Monoclonal antibody-based enzyme immunoassay for detection of porcine plasma in fish surimi

Detection of porcine plasma using indirect ELISA was developed using mAb B4E1 for the prevention of their usage in human food that creates religious and health conflicts. The immunoassay has a CV < 20% and did not cross-react to other meat and non-meat proteins. The sensitivity of the assay is 0.25% (w/w) of porcine plasma in spiked raw and cooked fish surimi. The assay did not produce a false positive result for any of the commercial fish surimi tested that were not contain porcine plasma. Determination of a 60-kDa antigenic protein of porcine blood using Western blot confirmed its presence in the plasma fraction of the porcine blood. Further proteomic analysis involving liquid chromatography–tandem mass spectrometry (LC-MS/MS) revealed the 60-kDa protein to be porcine serum albumin.     

The thermal effect on vibration of zigzag single walled carbon nanotubes using nonlocal Timoshenko beam theory

Based on nonlocal theory of thermal elasticity mechanics, a nonlocal elastic Timoshenko beam model is developed for free vibration analysis of zigzag single-walled carbon nanotube (SWCNT) considering thermal effect. The nonlocal constitutive equations of Eringen are used in the formulations. The equivalent Young’s modulus and shear modulus for zigzag SWCNT are derived using an energy-equivalent model. Results indicate significant dependence of natural frequencies on the temperature change as well as the chirality of zigzag carbon nanotube. These findings are important in mechanical design considerations of devices that use carbon nanotubes.     

Numerical analysis of the crack growth path in the cement mantle of the reconstructed acetabulum

In this study, we use the finite element method to analyze the propagation's path of the crack in the orthopedic cement of the total hip replacement. In fact, a small python statement was incorporated with the Abaqus software to do in loop the following operations: extracting the crack propagation direction from the previous study using the maximal circumferential stresses criterion, drawing the new path, meshing and calculating again (stresses and fracture parameters). The loop is broken when the user's desired crack length is reached (number of propagations) or the value of the mode I stress intensity factor is negative. Results show that the crack propagation's path can be influenced by human body posture. The existing of a cavity in the vicinity of the crack can change its propagation path or can absolutely attract it enough to meet it. Crack can propagate in the outward direction (toward the acetabulum bone) and cannot propagate in the opposite direction, the mode I stress intensity factor increases with the crack length and that of mode II vanishes.     

Structure and electrical transport properties of pure and Li2O-doped CuO/MgO solid solution

The different electrical properties, σ, ?′, tan δ and E_σ of pure and Li₂O-doped CuO/MgO solid solution were investigated. The mole fraction of CuO (MF) was varied between 0.048 and 0.2. Pure and doped samples were subjected to heat treatments at 673 and 1073 K. The results revealed that the amount of CuO dissolved in MgO lattice increases progressively by increasing the MF as evidenced from the progressive decrease in the intensity of all diffraction lines of undissolved CuO phase. The dissolution process of copper ions in MgO lattice was accompanied by progressive increase in its lattice parameter. This process being conducted at 1073 K was accompanied by a significant progressive increase in the values of σ, ?′ and tan δ with subsequent decrease in the value of E_σ. The increase in the MF value of CuO from 0.048 to 0.2 led to a significant increase in the value of σ_DC, measured at room temperature, from 6.33 × 10⁻¹² to 9.9 × 10⁻¹⁰ Ω⁻¹ cm⁻¹ and E_σ decreases from 0.76 to 0.58 eV.Li₂O doping of the investigated system followed by calcination at 1073 K resulted in a measurable increase in values of σ, ?′ and tan δ with subsequent decrease in E_σ. These results were discussed in the light of the possible effective increase in the charge carriers concentration (Cu²⁺ions dissolved in MgO lattice) and also to an effective increase in mobility of these charge carriers by Li₂O doping.     

Virgin olive oil (VOO) production in Tunisia: The commercial potential of the major olive varieties from the arid Tataouine zone

The commercial potential of olive oils from three consecutive crop years, derived from the main autochthonous olive varieties Chemlali Tataouine, Fakhari Douirat, Zarrazi Douirat and Dhokar Douirat grown in the arid region of Tataounine (Tunisia) was examined with regards to stability and nutrition aspects. Several characteristics such as fatty acid composition, the extremely high phenol-type antioxidant content, and the low levels of green pigments suggested that these oils, the only fat source for the local people, are of promising composition. Efforts to develop commercial products from these varieties could improve antioxidant intake of the local population. The introduction of Good Manufacturing Practices is a prerequisite so that the quality observed for oils obtained by an Abencor system to be achieved also in real life. This can be feasible through appropriate oleoculture, which is often the only viable agricultural activity in remote arid regions such as Tataouine.     

Dietary exposure of Tunisian adult population aged from 19 to 65 years old to pesticides residues

ABSTRACT

Dietary exposure of the Tunisian adult population to pesticide residue was assessed using the Total Diet Study method. In the present study 170 pesticides were searched for in 42 aggregated foods characterised by 64 food samples representing the Tunisian diet. All the food samples were collected, prepared, and analysed for remains of pesticides including organochlorine, organophosphorous, carbamates and pyrethroids. The GC-MS analysis and the LC-MS/MS analysis and some other specific analytical methods were employed for the quantification of the pesticide residues in the food samples. Results revealed that21pesticides reached amounts greater than the LOQ(12.3%) and 149 pesticides reached amounts below the LOD (88%).For the 21 pesticides quantified, the ADI was not exceeded. For the 149 non-quantified pesticides, an interval defined by the lower and upper bounds was defined to assess the dietary exposure of the Tunisian adult population to those pesticides. We conclude that 8 pesticides theoretically exceed the ADI with the 95^th percentile of exposure, those are: Diféthialone, Brodifacoum, Bromadiolone, Glufosinate, Heptachlor, Dieldrin Aldrin Oxydemeton-methyl. This study concludes that there is a low dietary exposure to pesticide residue of the Tunisian adult population. In fact, all the cases where the ADI was exceeded were theoretical due to the lower ADI value used.     

哒嗪与联苯胺的新型共轭共聚物的合成及其表征

报道了联苯二胺在二价镍配合物存在下直接与3,6-二氯哒嗪的格氏(Grignard)试剂共聚合成了联苯二胺与哒嗪共聚物,新合成方法所得的共聚物通过红外光谱(FT IR),核磁共振谱(1H NMR)等进行了表征。该合成方法所得聚合物收率为60%。该类聚合物的紫外-可见吸收光谱中在313 nm处观察到最大吸收峰。根据聚合物的粉末X-射线衍射谱(XRD),热重分析(TG)对所得聚合物的结晶性和热稳定性进行了分析。