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161.
Ponnusamy Edwin Samson Selvadurai Senthil Kumaran Shanmugam Vigneshwaran Das Oisik 《先进技术聚合物》2023,34(1):363-376
This study investigated the dynamic mechanical properties of hybrid intraply carbon/E-glass epoxy composites with different orientations and stacking sequences under different loading conditions with increasing temperature. A neat epoxy and five various hybrid composites such as Carbon (0°)/E-glass (90°), Carbon (45°)/E-glass (135°), Carbon (90°)/E-glass (0°), Carbon/E-glass (alternating layer), and Carbon/E-glass (alternating layer 45°) were manufactured. Three-point bending test and dynamic mechanical test were conducted to understand the flexural modulus and viscoelastic behavior (storage modulus, loss modulus, and loss tangent) of the composites. Dynamic mechanical test was performed with the dual cantilever method, at four different frequencies (1, 5, 10, and 20 Hz) and temperatures ranging from 30 to 150°C. The experimental results of storage modulus, loss modulus, and loss tangents were compared with the theoretical findings of neat epoxy and various hybrid composites. The glass transition temperature (Tg) increased with the increase in frequency. A linear fit of the natural log of frequency to the inverse of absolute temperature was plotted in the activation energy estimation. The interphase damping (tanδi) between plies and the strength indicator (Si) of the hybrid composites were estimated. It was observed that the neat epoxy had more insufficient storage and loss modulus and a high loss tangent at all the frequencies whereas hybrid composites had high storage and loss modulus and a low loss tangent for all the frequencies. Compared with other hybrid composites, Carbon (90°)/E-glass (0°) had higher strength and activation energy. The result of reinforcement of hybrid fiber in neat epoxy significantly increases the material's strength and stability at higher temperatures whereas decreasing free molecular movement. 相似文献
162.
This article describes some of the exciting results obtained during the study of the gelation behavior of bile acid derivatives in the authors laboratory. The serendipitous discovery of charge-transfer interaction promoted gelation of organic solvents by (steroid)pyrene derivatives/TNF is presented. In this class of molecules, the effect of the location of the chiral center in chiral gelators on the overall chirality of the aggregates in the gel was studied. Also described are the aggregation behavior of bile acid based aqueous gelators which led us to postulate design principals to obtain bile acid based aqueous/organogelators. 相似文献
163.
Karunakaran Balaji Jagadish Vijayakumar Ponnusamy Kasirajan Sankaran Sivanesan Senthilkumar Rajagopalan Vijayaraghavan Jayaraman Selvaraj Maria Francis Yuvaraj 《Molecules (Basel, Switzerland)》2021,26(21)
Chemicals can induce nephrotoxicity, with damage to different segments of the nephron and deterioration of renal function. Nephrotoxicity due to exposure to a toxin such as carbon tetrachloride, sodium oxalate, or heavy metals is the most common cause of kidney injury. The current study aimed to evaluate the protective effects of Celastrus paniculatus seed extract against lead-acetate-induced nephrotoxicity by evaluating the histopathology, immunohistochemistry, ultrastructure, and phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway. Twenty-four rats were divided into four groups (n = 6 per group): group 1 contained normal animals and served as the control; group 2 received lead acetate (30 mg/kg body weight (b.w.)/day, oral); group 3 received lead acetate and the standard drug N-acetylcysteine (NAC, 200 mg/kg b.w./day, oral); and group 4 received lead acetate and the ethanolic extract of C. paniculatus seed (EECP; 800 mg/kg b.w./day, oral). Treatment was given for 28 consecutive days. The data were analyzed using one-way analysis of variance with SIGMA PLOT 13 using SYSTAT software followed by Newman–Keul’s test for comparison between the groups. EECP ameliorated the adverse changes caused by lead acetate. PI3K and AKT messenger RNA (mRNA) levels were diminished in lead-acetate-treated rats. Treatment with EECP inhibited the occurrence of shrunken cells, the atrophy of glomeruli, and degenerative changes in renal tubules caused by lead acetate. Interestingly, the PI3K and AKT mRNA levels were significantly increased in EECP-treated animals. Our results clearly evidence for the first time that C. paniculatus seed extract inhibits lead-acetate-induced detrimental changes in kidneys by regulating PI3K/AKT signaling pathways. 相似文献
164.
Meccanica - The paper deals with the study of effect of gravity modulation on double-diffusive convection in a dielectric liquid for the cases of rigid-rigid and free-free boundaries. Using a... 相似文献
165.
Gurusamy Harichandran Savarimuthu David Amalraj Ponnusamy Shanmugam 《Journal of Saudi Chemical Society》2018,22(2):208-217
A one-pot Amberlite IRA-400 Cl resin catalyzed the in-situ generation of imines from various aldehydes and primary amines followed by reduction with sodium borohydride affording corresponding secondary amines. The secondary amines thus obtained were utilized for the IRA-400 Cl resin catalyzed multicomponent synthesis of 3-aminoalkylated indoles using a number of aldehydes and indole. Mild condition, easy work-up, and environmentally benign nature of the synthetic strategy make it both practical and attractive. 相似文献
166.
In this article, we prove several different improved versions of the classical Bohr's inequality. All the results are proved to be sharp. 相似文献
167.
Ponnusamy Sami Kandasamy Venkateshwari Natarajan Mariselvi Arunachalam Sarathi Kasi Rajasekaran 《Transition Metal Chemistry》2009,34(7):733-737
The rates of the electron transfer reaction of l-cysteine and thioglycolic acid with the polyoxometalate, [PVVW11O40]4−, have been measured spectrophotometrically in aqueous acid medium. The polyoxometalate oxidizes cysteine to cystine and thioglycolic
acid to dithioglycolic acid and gets reduced to heteropoly blue, [PVIVW11O40]5−. The order of the reaction with respect to oxidant is one, whereas the reaction shows second order dependence on the substrates.
The rate–pH profile shows that both the unionized and ionized thiol groups of the substrates are active species involved in
electron transfer. A suitable mechanism has been proposed for the title reaction based on the results of kinetic studies. 相似文献
168.
The main aim of this paper is to study the Lipschitz continuity of certain \((K, K^{\prime })\)-quasiconformal mappings with respect to the distance ratio metric, and the Lipschitz continuity of the solution of a quasilinear differential equation with respect to the distance ratio metric. 相似文献
169.
170.
In this paper, we study the Dini functions and the cross-product of Bessel functions. Moreover, we are interested on the monotonicity patterns for the cross-product of Bessel and modified Bessel functions. In addition, we deduce Redheffer-type inequalities, and the interlacing property of the zeros of Dini functions and the cross-product of Bessel and modified Bessel functions. Bounds for logarithmic derivatives of these functions are also derived. The key tools in our proofs are some recently developed infinite product representations for Dini functions and cross-product of Bessel functions. 相似文献