Synthesis and Antifungal Activity of Some New Guanidines

The synthesis of some N-subsituted -N'-aryl-N"-ethyl/benzyl guanidines (II) and (III) and their precurser thiocarbamides (I) has been carried out. All these compounds have been screened in vitro for their antifungal activity against Helminthosporium oryzae, Drechlere papendor fii and Alternaria alternata. In general, N-substituted-N'aryl-N"benzyl guanidines except N-(p-pyrolidinopropoxyphenyl)-N'-p-tolyl-N"-benzyl guanidine possess high antifungal activity against all the test fungi at concentration 2% and comparatively less at 0.2% None of these compounds exhibit fungicidal activity at lower concentrations (0.02 and 0.002%)

A new dimeric coumarin from Boenninghausenia albiflora Reichb and Meissner (Rutaceae)

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From Moscow with love

One of the less researched aspects of postcolonial India’s “progressive” culture is its Soviet connection. Starting in the 1950s and consolidating in the 1960s, the Union of Soviet Socialist Republics invested in building up “committed” networks amongst writers, directors, actors, and other theater- and film-practitioners across India. Thus, an entire generation of cultural professionals was initiated into the anticolonial solidarity of emerging Afro-Asian nations that were seen, and portrayed, by the Soviets as being victims of “Western” imperialism. The aspirational figure of the New Soviet Man was celebrated through the rise of a new form of “transactional sociality” (Westlund 2003). This paper looks at selected cases of cultural diplomacy—through the lens of cultural history—between the USSR and India for two decades after India’s Independence, exploring the possibility of theorizing it from the perspective of an anticolonial cultural solidarity that allowed agency to Indian interlocutors

Catalytic effects of Cu-Co* on the thermal decomposition of AN and AN/KDN based green oxidizer and propellant samples

This paper presents the catalytic effects of Cu-Co* catalyst on the decomposition of AN and AN/KDN based oxidizer and propellant samples. Ozawa-Flynn-Wall (OFW) iso-conversional method was used for the kinetic studies and to compute the activation energy (Ea) values for various decomposition steps of the prepared oxidizer and propellant samples in the temperature range of 50–500 °C. TG-DTG experiments were carried out for both oxidizer and propellant samples at the heating rates of 3, 5, and 10 °C/min. AN/KDN based oxidizer samples were prepared by an evaporative co-crystallization method. Citric acid sol-gel method was used for the synthesis of Cu-Co* catalyst. The propellant sample contains HTPB as the fuel binder along with other ingredients such as TDI, DOA, and Glycerol. The Cu-Co* catalyst was used as 2% by weight to the total weight of catalyzed oxidizer and propellant samples. It was observed from the present study that, Cu-Co* catalyst helps in reducing the Ea values for AN and AN based propellant samples. However, with the percentage increment of KDN in the AN crystals, Ea value increases. Further, it was observed that Cu-Co* catalyst stabilizes the initial partial decomposition of KDN. Keywords: AN, KDN, Green oxidizer, Green propellant, Catalytic effect, OFW method, Activation energ

Cu–Co–O nano-catalysts as a burn rate modifier for composite solid propellants

Nano-catalysts containing copper–cobalt oxides (Cu–Co–O) have been synthesized by the citric acid (CA) complexing method. Copper (II) nitrate and Cobalt (II) nitrate were employed in different molar ratios as the starting reactants to prepare three types of nano-catalysts. Well crystalline nano-catalysts were produced after a period of 3 hours by the calcination of CA–Cu–Co–O precursors at 550 °C. The phase morphologies and crystal composition of synthesized nano-catalysts were examined using Scanning Electron Microscope (SEM), Energy Dispersive Spectroscopy (EDS) and Fourier Transform Infrared Spectroscopy (FTIR) methods. The particle size of nano-catalysts was observed in the range of 90 nm–200 nm. The prepared nano-catalysts were used to formulate propellant samples of various compositions which showed high reactivity toward the combustion of HTPB/AP-based composite solid propellants. The catalytic effects on the decomposition of propellant samples were found to be significant at higher temperatures. The combustion characteristics of composite solid propellants were significantly improved by the incorporation of nano-catalysts. Out of the three catalysts studied in the present work, CuCo-I was found to be the better catalyst in regard to thermal decomposition and burning nature of composite solid propellants. The improved performance of composite solid propellant can be attributed to the high crystallinity, low agglomeration and lowering the decomposition temperature of oxidizer by the addition of CuCo-I nano-catalyst