Tautomerism and Reactions of 1H-1,2,4-Triazole-5-thiones with Hydrazonoyl Halides

The acid dissociation constants (K_a) of a series of 3,4-diaryl-1H-1,2,4-triazole-5-thiones ( 1 ) were determined and were found to correlated linearly with Hammett substituent constants; log K_a = 1.06 σ_x − 11.01. Such a result indicates that 1 exists essentially in one tautomeric form namely the thione form. Reactions of 1 with hydrazonoyl chlorides 2 gave the thiohydrazides 5 . Similiar reaction of 3-phenyl-1H(4H)- 1,2,4-triazole-5-thione 1g with 2a gave the thiohydrazide 5h which was converted into 1,3,5-triphenyl-1,2,4-triazolo[3,4-c]-1,2,4-triazole ( 9 ). The latter was also prepared from 3-phenyl-5-methylthio-4H-1,2,4-triazole ( 6 ) and 2a . The mechanism of the reaction of 1 with 2 is discussed.     

Study of the recrystallization process of AlMgSi alloys containing transition elements

The addition of small amounts of the transition elements such as Zr, Mn and Cr, which have a low solubility in the α-aluminium solid solution and thus form dispersoids, to AlMgSi alloys showed that these elements inhibit recrystallization when the alloys are pre-heated prior to deformation. The formation of coarse particles during casting is mainly due to the presence of Fe. This type of particles found, even, in solution treated samples. The particles, with a diameter exceeding 3 μm, accelerate the recrystallization as they provide good sites for nucleation of recrystallization. Precipitate free zones (PFZ's) developed around the coarse particles favour nucleation of recrystallization by subgrain growth. The presence of dispersoid particles is found to shift the recrystallization energy peak towards higher temperatures. Intermediate annealing before deformation allowed to achieve a high rate of deformation by cold rolling due to the removal of the solute from the matrix by the formation of the hardening phases. Optical and transmission electron microscopy, hardness measurements and differential scanning calorimetry (DSC) were used to study the kinetics of precipitation and recrystallization of the AlMgSi alloys.     

Preservation of fatty duck liver by high pressure treatment

Fatty liver samples from duck were treated with high pressures and packaged in multilayer films. Microbiological analysis, permeability of the films to oxygen and fat loss, caused by melting, were assessed after pressure or thermal treatment. Microbiological analysis showed a noteworthy reduction in the total aerobic mesophilic flora and eradication of the coliform flora, whichever film or treatment was used. Nevertheless, a significant bacterial flora was observed during storage at 4 °C from 42 days with a polyethylene/polyamide/polyethylene film and a sample which had been treated with pressure. But, treatment at 550 MPa for 55 °C and 20 min, in combination with two low oxygen permeability films (ethylene and vinyl alcohol copolymer) gave a product with long storage life (90 days) at 4 °C and a significant reduction in the melting of lipids.     

Preparation and catalytic activity of nanostructured Pd catalysts supported on hydrogenotitanate nanotubes

Nanostructured palladium particles (nanorods, icosahedra, cubes) were synthesized in aqueous solution using a seeding-mediated approach with a structure-directing agent. These nanostructured Pd particles were then impregnated onto hydrogenotitanate nanotubes using two different impregnation procedures. The as-prepared catalysts were then tested in the selective hydrogenation of cinnamaldehyde at 323 K under 10 bars of H₂. The selectivity is influenced by the morphology of the Pd nanostructured particles with a higher selectivity into saturated alcohols when the proportion of (111) Pd sites increases.     

Analysis of two particular iterative learning control schemes in frequency and time domains

This paper deals with iterative learning control design for multiple-input multiple-output (MIMO), linear time-invariant (LTI) systems. Two particular ILC schemes are considered and analyzed in both frequency and time domains. Some remarks on the convergence, implementation, robustness with respect to disturbances and reinitialization errors, as well as positive realness issues related to both schemes are provided.     

Fuzzy classification in dynamic environments

The persistence and evolution of systems essentially depend on their adaptivity to new situations. As an expression of intelligence, adaptivity is a distinguishing quality of any system that is able to learn and to adjust itself in a flexible manner to new environmental conditions and such ability ensures self-correction over time as new events happen, new input becomes available, or new operational conditions occur. This requires self-monitoring of the performance in an ever-changing environment. The relevance of adaptivity is established in numerous domains and by versatile real-world applications. The present paper presents an incremental fuzzy rule-based system for classification purposes. Relying on fuzzy min–max neural networks, the paper explains how fuzzy rules can be continuously online generated to meet the requirements of non-stationary dynamic environments, where data arrives over long periods of time. The approach proposed to deal with an ambient intelligence application. The simulation results show its effectiveness in dealing with dynamic situations and its performance when compared with existing approaches.     

Strain–Stress Formation During Stationary and Intermittent Drying of Deformable Media

The goal of this work is to study the effect of different drying conditions on the induced stresses within deformable media, the drying kinetics, and the energy consumption. A comparison between stationary and intermittent drying with periodically changing air temperature was performed. A theoretical formulation of the coupled heat, mass, and momentum transfers in saturated porous media was established. The model is based on the averaging theory. The thermo-hydro-mechanical coupling was closed using the effective stress theory of Terzaghi. In this approach, the viscoelastic behavior of the medium was considered. A bi-dimensional-shaped bentonite sample was used for numerical tests. The evolution of drying kinetics and stresses within the material during drying at constant and intermittent conditions was presented. It was observed that a non-stationary drying with smaller period applied at the end of the constant drying rate phase has the best effects on the product quality and energy gain without considerably extending the drying time.     

Triacylglycerols and Phospholipids Composition of Caper Seeds (<Emphasis Type="Italic">Capparis spinosa</Emphasis>)

The goal of this study is to evaluate for the first time the composition of triacylglycerols (TAG) using ESI-TOF-MS and phospholipids species using HPLC–ESI-TOF-MS of two Capparis spinosa seed oil populations. Results show that LOO, LOP, LLO, OOO, PLL and POO were the major molecular species of triacylglycerol detected in caper seeds; where L represents linoleic acid; O, oleic acid; and P, palmitic acid. The TAG composition was significantly different among the two C. spinosa populations. In Ghar el Melh population, LOO (15.7%) was detected as the dominant TAG molecular species, followed by LOP (13.2%), LLO (12.0%) and OOO (11.4%); while, the dominant fraction was LLO (14.2%) followed by LOO (14.1%), LOP (11.5%) and PLL (10.5%) in Chouigui samples. The major component in the phospholipids fraction was phosphatidylinositol (ca. 54–91%), followed by phosphatidylglycerol, phosphatidylethanolamine and phosphatidic acid. A variety of molecular species within each class were identified. The major component in all phospholipids species contains a C-18:1 lipid chain. C16:0/C18:2-PI (ca. 28–31%) was the most abundant PI. PG species were mainly C18:2/C18:1-PG (25–32%). The major PE was C18:1/C18:1-PE (44–75%). The major PA species was C18:1/C18:1-PA (22–24%).