The impact of the pitching motion on the structure of the vortical flow over a slender delta wing under sideslip angle

The primary purpose of this investigation is to observe the effect of the pitching motion on the vortical flow structure and bursting of leading-edge vortices over a delta wing under the sideslip angle, β using a dye visualization technique. In the current work, a delta wing with a sweep angle of Λ = 70° was oscillated in upstroke and downstroke direction to be able to discover the influence of pitching motion on the flow characteristics of the delta wing. The values of mean angles of attack were selected as α_m = 25° and α_m = 35°, and the sideslip angle was altered from β = 0 to 16°. The delta wing oscillated with the various periods of T_e = 5 s, 20 s, and 60 s, respectively. Amplitude of motion was adjusted as α_o =  ± 5°. It is found that the pitching motion of the delta wing under the sideslip angle β varies the location of the vortex bursting and vortical flow structure substantially.

     

Synthesis of a Block Copolymer Consisting of Oligocellulose and Oligochitin

Abstract

Block copolymerization of a hydroxy-terminated oligotriacetylcellulose (1) with a hydroxy-terminated oligodihexanoylchitin (2) was carried out using 4,4′-methylenedi(phenyl isocyanate) as a coupling reagent. The product copolymer has a structure 4 consisting of alternating oligotriacetyl-cellulose and oligodihexanoylchitin units. The complete deprotection of 4 was achieved to give a cellulose-chitin block copolymer 5.     

Development of Novel Indole-Based Bifunctional Aldose Reductase Inhibitors/Antioxidants as Promising Drugs for the Treatment of Diabetic Complications

Aldose reductase (AR, ALR2), the first enzyme of the polyol pathway, is implicated in the pathophysiology of diabetic complications. Aldose reductase inhibitors (ARIs) thus present a promising therapeutic approach to treat a wide array of diabetic complications. Moreover, a therapeutic potential of ARIs in the treatment of chronic inflammation-related pathologies and several genetic metabolic disorders has been recently indicated. Substituted indoles are an interesting group of compounds with a plethora of biological activities. This article reviews a series of indole-based bifunctional aldose reductase inhibitors/antioxidants (ARIs/AOs) developed during recent years. Experimental results obtained in in vitro, ex vivo, and in vivo models of diabetic complications are presented. Structure–activity relationships with respect to carboxymethyl pharmacophore regioisomerization and core scaffold modification are discussed along with the criteria of ‘drug-likeness”. Novel promising structures of putative multifunctional ARIs/AOs are designed.     

About geometrization of the dynamics

The connection between Killing tensors and Lax operators are presented. The Toda lattice case and the Rindler system are analyzed in details.     

Synthesis of Hyperbranched Aminopolysaccharides

Sugar dihydroozaxole monomers with two free hydroxyl groups undergo acid-catalyzed polymerization to hyperbranched aminopolysaccharides [Eq. (a)]. Their molecular weights were determined by the light-scattering method to be between 2.3×10⁵ and 7.6×10⁵. The degree of branching determined by ¹H NMR spectroscopy after reaction with [iPr₂Si(Cl)]₂O is close to the ideal value. Ts=MeC₆H₄SO₂, CSA=10-camphorsulfonic acid.     

Free radical photopolymerization initiated by UV and LED: Towards UV stabilized,tack free coatings

UV stabilizers (UV absorbers and Hindered Amine Light Stabilizers‐HALS) are added to UV‐curable formulations to provide long‐term durability. The influence of HALS and the filtering effect of UV absorbers are investigated under UV and LED irradiation by using different photoinitiating systems in free radical photopolymerization. The contribution of irradiation conditions and initiating systems on the filtering effect is discussed by performing Real‐Time Fourier Transform Infrared Spectroscopy (RT‐FTIR) and Confocal Raman Microscopy. Additionally, to get quantitative information about the light absorbed by the photoinitiator, without and with the filtering issue arising from UV stabilizers, series of calculations are carried out by taking into account the amount of light absorbed by the compounds and the intensity of the incident light. Finally, formulations are optimized with respect to surface inhibition to obtain tack free coatings in air atmosphere in the presence of UV stabilizers under visible light. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 3597–3607     

Intercalation chemistry of aluminium dihydrogentriphosphate with weak bases and polymerization of aniline between its layers

Weak bases such as 2-aminopyridine, 4-aminopyridine,o-phenylenediamine,p-phenylenediamine and aniline were intercalated into aluminium dihydrogentriphosphate (ADHP) using ultrasonic wave irradiation. The interlayer spacing of ADHP increased from 8.1 Å to 12.4–20.0 Å. From the values of the layer expansions and host/guest ratios, bilayer or monolayer structures were considered. Chemical oxidation of the aniline resulted in the formation of polyaniline in the ADHP layers.Author for correspondence.     

Intercalation of Azo Compounds into Layered Aluminium Dihydrogentriphosphate and a Layered Double Hydroxide

The inner surfaces of inorganic layered compounds such as aluminium dihydrogen-triphosphate (ADHP) and layered double hydroxide (LDH) were modified by azo compounds. Upon intercalation of 4-phenylazoaniline and 4,4-azodianiline into ADHP, the interlayer spacing increased from 6.4 to 21.5 Å and 20.6 Å, respectively. The intensity of IR peaks due to P-–OH of ADHP and amino groups of guests decreased by the thermal treatment of the intercalates. The interlayer spacings also decreased to 16.9 Å and 16.7 Å, respectively, indicating a dehydration reaction between P–-OH and amino groups. The LDH inner surface was modified by the reaction with trans-p-phenylazobenzoylchloride (PAB-Cl). Upon surface modification, the interlayer spacing increased from 7.6 Å to about 27 Å. The absorption of this surface-modified LDH near 410 nm increased upon irradiation with UV light and decreased upon irradation with visible light, indicating the occurrence of trans–cis isomerization of PAB-Cl between the layers.     

The effect of an aminoalcohol on the polymerization of acrylates with type II initiators

In this study, the authors report the use of an aliphatic amine and an aromatic aminoalcohol as synergists with various Type II initiators by using Photo-DSC (Photo-differential scanning calorimetry) technique. The photopolymerization of triacrylate and diacrylate was performed under nitrogen atmosphere in the presence of an amine or aminoalcohol with type II initiators, which allowed us to compare the efficiency of the initiating radicals. The oxygen scavenging role of the amine was left out.