Phase Transitions in the BiVO<Subscript>4</Subscript>-<Emphasis Type="Italic">n</Emphasis>PbO (<Emphasis Type="Italic">n</Emphasis> = 1, 2) System: Structural–Electrical Properties Relationships

In a general survey of nPbO-BiVO₄ compounds, interesting phases corresponding to n = 1: PbBiVO₅, and n = 2: Pb₂BiVO₆ are described. A phase transition has been unambiguously characterized for PbBiVO₅. The crystal structures were solved from twinned crystals at room temperature (α phase, triclinic, S.G. P-1) and at 530°C (β phase, monoclinic, C2/m). Powder neutron diffraction experiments confirmed these settings and both room-temperature (RT) and high-temperature (HT) refinements corroborated space group choices, clearing up a literature controversy about the centrosymmetry of the α phase, and identifying structural modifications occurring under the α → β transition. Cationic substitutions for V were tested and PbBi(V_1−x M _x )O₅ (M = P) solid solutions identified. Pb₂BiVO₆ (n = 2) is a compound showing several successive structural transitions, i.e., α → β → δ. Structures of α and δ forms have been previously described from powder diffraction data (x-ray and neutron). In this work, we have refined these structures from single-crystal data, and the resolution of the intermediate β form, so far unsolved, was possible through a stabilization thermal cycle; its complete structural understanding required a 4D formalism. Two new polymorphic phases, α′ and δ′, were obtained by substituting Mn or P for V; their structures are closely related to, respectively, the α phase at room temperature, and the δ phase at 680°C. Electrical conductivities of all structurally characterized compositions were investigated, and correlations were drawn between their conduction properties and structural characteristics. Conductivity properties measured under variable O₂ partial pressures for Pb₂Bi(V_0.75P_0.25)O₆ were interpreted as a mixed ionic–electronic (p-type) conduction mechanism.     

Decision support tool for used oil regeneration technologies assessment and selection

Regeneration is the most efficient way of managing used oil. It saves money by preventing costly cleanups and liabilities that are associated with mismanagement of used oil, it helps to protect the environment and it produces a technically renewable resource by enabling an indefinite recycling potential. There are a variety of processes and licensors currently offering ways to deal with used oils. Selecting a regeneration technology for used oil involves "cross-matching" key criteria. Therefore, the first prototype of spent oil regeneration (SPORE), a decision support tool, has been developed to help decision-makers to assess the available technologies and select the preferred used oil regeneration options. The analysis is based on technical, economical and environmental criteria. These criteria are ranked to determine their relative importance for a particular used oil regeneration project. The multi-criteria decision analysis (MCDA) is the core of the SPORE using the PROMETHEE II algorithm.     

On SISO and MIMO variable structure control of non linear distributed parameter systems: application to fixed bed reactors

This paper deals with the design of variable structure control of distributed parameter systems. The control problem is discussed in relation to a model consisting of a set of non-linear, time varying partial differential equations of hyperbolic type. A formulation of a Single Input–Single Output (SISO) variable structure controller based on the distributed parameter model (late lumping control) is given. An extension to the Multiple Input–Multiple Output (MIMO) case is derived when the control variables are coupled and located on boundary conditions. A theoretical proof of DPS convergence in sliding mode is given. A fixed bed bioreactor in which drinkable water is treated, was used as a simulated example to prove the effectiveness of the control design. The bioreactor must control the harmful component concentrations in such a way that the quality of water fulfils international standards.     

Growth,Proliferation and Metastasis of Prostate Cancer Cells Is Blocked by Low-Dose Curcumin in Combination with Light Irradiation

Although anti-cancer properties of the natural compound curcumin have been reported, low absorption and rapid metabolisation limit clinical use. The present study investigated whether irradiation with visible light may enhance the inhibitory effects of low-dosed curcumin on prostate cancer cell growth, proliferation, and metastasis in vitro. DU145 and PC3 cells were incubated with low-dosed curcumin (0.1–0.4 µg/mL) and subsequently irradiated with 1.65 J/cm² visible light for 5 min. Controls remained untreated and/or non-irradiated. Cell growth, proliferation, apoptosis, adhesion, and chemotaxis were evaluated, as was cell cycle regulating protein expression (CDK, Cyclins), and integrins of the α- and β-family. Curcumin or light alone did not cause any significant effects on tumor growth, proliferation, or metastasis. However, curcumin combined with light irradiation significantly suppressed tumor growth, adhesion, and migration. Phosphorylation of CDK1 decreased and expression of the counter-receptors cyclin A and B was diminished. Integrin α and β subtypes were also reduced, compared to controls. Irradiation distinctly enhances the anti-tumor potential of curcumin in vitro and may hold promise in treating prostate cancer.     

Evaluation of the effect of fennel (Foeniculum vulgare Mill) essential oil addition on the quality parameters and shelf‐life prediction of yoghurt

Yoghurt was prepared by adding three concentrations of fennel essential oil (FEO) (2.5, 5 and 7.5 µL) in 100 mL of pasteurised milk. Fennel essential oil did not affect the viability of yoghurt starters during fermentation. Based on sensory analysis, only the 5‐µL FEO concentration was incorporated in order to investigate the physicochemical and microbiological properties of enriched yoghurt during storage. Results showed that FEO in yoghurt did not significantly affect the quality after acidification (P > 0.05). However, total solid content, syneresis and lightness (L*) differed significantly (P < 0.05). Bacterial counts indicated that the control yoghurt had the highest values. Fortified yoghurt had an increased shelf life of 29 days.     

Antioxidant,lipase and ACE-inhibitory properties of camel lactoferrin and its enzymatic hydrolysates

The antioxidant and the lipase and the angiotensin-converting enzyme (ACE) inhibitory properties of camel lactoferrin and its hydrolysates elaborated with four proteolytic enzymes (trypsin, α-chymotrypsin, pancreatin and papain) were assessed. Lactoferrin was purified from camel colostrum using cation exchange chromatography. Camel lactoferrin hydrolysates showed different degrees of hydrolysis, reverse phase-HPLC profiles and molecular weight distributions, reflecting heterogeneity in terms of polarity and molecular weight of the generated peptides. Camel lactoferrin hydrolysates exhibited higher antioxidant, lipase and ACE inhibitory activities than native lactoferrin. Pancreatin-generated hydrolysates showed the highest lipase inhibitory activity (48.1%), while papain-generated hydrolysates presented the greatest ACE inhibitory activity (89.14%).     

Idea,process and analyses of hydrogen production from atmospheric pollutant

With the considerable amounts of Sulfur dioxide (SO₂) discharged from the sulfuric acid production unit of the Tunisian Chemical Group (TCG), questions have arisen regarding the treatment of this very dangerous atmospheric pollutant which is crucial. Here, we used SO₂ to produce hydrogen. Sulfur dioxide was fed into a PEM electrolysis, the dissolved SO₂ was oxidized at the anode to produce sulfuric acid, whereas hydrogen was produced at the cathode. By measurements on site complemented by mass balances, we determined the quantities of sulfur dioxide regenerated in the atmosphere. We focused on the startup stage which is the most polluting as the amount of sulfur dioxide generated during this step is enormous. By simulation with Aspen Plus we found that two processes were possible to realize this idea; one with absorption and the other with compression. The same software was used to determine the operating parameters that can run the processes, taking into account the permissible level of SO₂ released into the atmosphere and the production of the highest amount of hydrogen. After a comparative study between the two processes, we selected the process with absorption. An exergetic study was conducted. The exergy loss of the absorption process was equivalent to 563 kJ/mol of H₂. This amount is low compared to other methods. The results show that the new process has the highest exergy efficiency (η_Ex = 90%). This was achieved through Life Cycle Analyses (LCA) which showed that the process with absorption had the highest impact on marine aquatic Eco-toxicity, whereas other impact categories were relatively insignificant.     

Effects of highly purified sardine proteins on lipid peroxidation and reverse cholesterol transport in rats fed a cholesterol-rich diet

The effect of highly purified sardine proteins was compared with that of casein on serum and lipoproteins lipid peroxidation and reverse cholesterol transport. Lecithin:cholesterol acyltransferase (LCAT) activity, high density lipoproteins (HDL₂ and HDL₃) composition and serum lipid and lipoproteins peroxidation were determined in rats fed a cholesterol-rich diet. Hypercholesterolemic rats were divided into two groups fed diets enriched with cholesterol and containing 20% of highly purified sardine proteins (SPc) or casein (CASc) for 28 days. A control group was fed a standard diet (CAS). Compared with CAS and CASc, the thiobarbituric acid reactive substances (TBARS) concentrations of low density lipoprotein (LDL)–HDL₁ in SPc were 3.5- and 1.7-fold higher compared with casein diets. TBARS in HDL₂ and HDL₃ were, respectively, 2.3- and 1.6-fold lower in SPc compared with CASc. In SPc group, LCAT activity was higher compared to CASc and CAS (P < 0.05). Purified sardine proteins had no beneficial effects on LDL-cholesterol and lipid peroxidation. However, they reduced HDL oxidation and improved reverse cholesterol transport, in the hypercholesterolemic rat.