Investigating laser rapid manufacturing for Inconel-625 components

This paper presents an investigation of laser rapid manufacturing (LRM) for Inconel-625 components. LRM is an upcoming rapid manufacturing technology, it is similar to laser cladding at process level with different end applications. In general, laser-cladding technique is used to deposit materials on the substrate either to improve the surface properties or to refurbish the worn out parts, while LRM is capable of near-net shaping the components by layer-by-layer deposition of the material directly from CAD model. In the present study, a high-power continuous wave (CW) CO₂ laser system, integrated with a co-axial powder-feeding system and a three-axis workstation were used. The effect of processing parameters during LRM of Inconel-625 was studied and the optimum set of parameters for the maximum deposition rate was established employing Orthogonal L9 array of Taguchi technique. Results indicated that the powder feed rate and the scan speed contributed about 56% and 26%, respectively to the deposition rate, while the influence of laser power was limited to 10% only. Fabricated components were subjected to non-destructive testing (like—ultrasonic testing, dye-penetrant testing), tensile testing, impact testing, metallographic examinations and micro-hardness measurement. The test results revealed defect-free material deposition with improved mechanical strength without sacrificing the ductility.     

Cyclopolymerization of diallylamine derivatives in dimethyl sulfoxide

Diallyl quaternary ammonium chlorides, bromides and N-alkyldiallylamine hydrochlorides were polymerized with ammonium persulfate (APS) in dimethyl sulfoxide (DMSO). The dependences of yield and molecular weight of polymers on polymerization conditions were examined and quaternary ammonium chlorides were found to have better polymerizability than bromides. The poly(diallyl quaternary ammonium chlorides) obtained with APS—DMSO system are expected to have quite high molecular weights, as determined from the measurement of limiting viscosity numbers of the polymers in NaCl aqueous solution.     

Synthesis of some novel substituted quinolines as potent analgesic agents

Summary 2-Chloroquinoline-3-carbaldehyde and 2-chloro-4-methylquinoline-3-carbaldehyde have been prepared from acetanilide and acetoacetanilidevia a Vilsmeier-Haack reaction. Upon reaction with phenyl hydrazine, hydroxylamine, urea, and thiourea in presence of acetic acid, these chloroaldehydes afforded the title compounds which exhibit a several times higher analgesic activity than noramidopyrine (NAP).

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Synthese einiger neuer substituierter Chinoline als stark analgetisch wirkende Substanzen

Zusammenfassung 2-Chlorchinolin-3-carbaldehyd und 2-Chlor-4-methylchinolin-3-carbaldehyd wurden, ausgehend von Acetanilid und Acetylacetanilid, über eineVilsmeier-Haack-Reaktion hergestellt. Reaktion dieser chlorsubstituierten Aldehyde mit Phenylhydrazin, Hydroxylamin, Harnstoff und Thioharnstoff ergab die Titelverbindungen, deren analgetische Aktivität jene von Noramidopyrin (NAP) um ein Mehrfaches übertrifft.

     

Kinetics of non-isothermal decomposition of acid maleato complexes of some bivalent metals

McGinn et al. [1] and Misra and Naik [2] studied the complexing capacity of maleic acid with metals. Edge [3] reported his findings on the pyrolysis of normal nickel maleato. This note is concerned with the estimation of kinetic parameters of the non-isothermal decomposition of acid maleato complexes of Co(II), Cu(II), Ni(II) and Cd(II).     

Molecular dynamics simulation of poly(3‐hexylthiophene) helical structure In Vacuo and in amorphous polymer surrounding

The stability of poly(3‐hexylthiophene) (P3HT) helical structure has been investigated in vacuo and in amorphous polymer surrounding via molecular dynamics‐based simulations at temperatures below and above the P3HT melting point. The results show that the helical chain remains stable at room temperature both in vacuo and in amorphous surrounding, and promptly loses its structure at elevated temperatures. However, the amorphous surrounding inhibits the destruction of the helix at higher temperatures. In addition, it is shown that the electrostatic interactions do not significantly affect the stability of the helical structure. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 2448–2456     

Quantitative Relationships Between Molecular Descriptors,Chromatographic Retention Behavior,and In Vitro Antituberculosis Activity of Phytol Derivatives

JPC – Journal of Planar Chromatography – Modern TLC - The lipophilic character of phytol derivatives has been studied using reverse-phase planar chromatographic procedures....