Novel fluorescent light-emitting polymer composites bearing 1,2,4-triazole and quinoxaline moieties: Reinforcement and thermal stabilization with silicon carbide nanoparticles by epoxide functionalization

New diamines bearing substituted 1,2,4-triazole and quinoxaline moieties with OCH3 or Br units were successfully synthesized and used for preparation of novel polyamides (PAs) by direct polycondensation with aromatic and aliphatic dicarboxylic acids. Chemical structure of the diamines as well as the resulting polymers was confirmed by elemental analysis, FT-IR and 1H NMR spectroscopic methods. Inherent viscosities of these PAs were in the range of 0.52–0.56 dL/g, they were readily soluble in a variety of organic solvents and formed low-coloured and tough thin films via solution casting. The aromatic PAs exhibited Tg between 284 °C and 300 °C, and their 10% weight loss temperatures were in excess of 420 °C with up to 70% char yield at 600 °C in N2. These PAs emitted green or blue fluorescence in dilute NMP solution and in the solid state. Silicon carbide (SiC) nanoparticles modified by silane coupling agent were used to prepare SiC/PA particle-reinforced composites by solution blending. Thermal properties of nanocomposites by using DMTA, DSC and TGA and also solubility and optical properties were investigated. The results show that both the uniform particle dispersion and the strong chemical bonding between the nanoparticles and the polymer–matrix contributed to the enhanced Tg, storage modulus and thermal stability

Synthesis and characterization of new fluorescent polyimides bearing 1,2,4-triazole and 1,2-diaryl quinoxaline: Study properties and application to the extraction/elimination of metallic ions from aqueous media

In this article, synthesis and characterization of triazole-based polyimides for solid-phase extraction of metal cations is described. For this purpose, new aromatic diamines containing 1,2,4-triazole and substituted 1,2-diaryl quinoxaline units were synthesized and used in polycondensation reaction with aromatic dianhydrates to yield poly(triazole-imide)s (PTAI)s. These polymers had inherent viscosities in the range of 0.58-0.62 dL/g and were readily soluble in a variety of organic solvents; they formed low-colored and tough thin films via solution casting. The PTAIs exhibited Tg between 280 and 338 \ub0C, and their 10% weight loss temperatures were in excess of 540 \ub0C with up to 76% char yield at 700 \ub0C in N2. These polymers emitted green or blue fluorescence in dilute NMP solution and in the solid state. The triazole groups in the polymer chain were efficient chelating/host units for heavy metal ions. One of these polymers, PTAI(1b), was investigated for its extraction capability for environmentally deleterious metal ions such as CrVI, CrIII, CoII, Zn II, PbII, CdII, HgII and Mn II from aqueous solutions either individually or in the mixture and at different pH values. \ua9 2012 Elsevier Ltd. All rights reserved

Gender Inequalities and the Effects of Feminine Artworks on Public Spaces: A Dialogue

Feminist street art aims to transform patriarchal spaces into places of gendered resistance by asserting a feminist presence in the city. Considering this, as well as women’s social life, their struggle against lingering forces of patriarchy, and relating features of inequality (domestic violence), there was a feminist installation artwork by the young Kurdish artist Tara Abdulla that shook the city of Sulaimani in Iraqi Kurdistan on 26 October 2020. She had prepared a 4,800‐meter‐long washing line covered with the clothes of 99,678 Kurdish women who were survivors of sexual and gender‐based violence. They installed it along the busiest street of the city (Salim Street). She used this piece of feminine to express her reaction to the Kurdish society regarding, the abuse that goes on silently, behind closed doors. She also aimed towards normalizing women’s bodies. After the installation, she received many controversial reactions. As her artwork was a pioneering project in line with feminist issues in Kurdistan which preoccupied the city for quite a while, the aim of this article is to investigate the diverse effects of her work on the current dialogue regarding gender inequality in the Kurdish society. To do this, we used the research method of content analysis on big data (Facebook comments) to investigate the public reactions of a larger number of locals. The Feminine effectively exposed some of the deep‐rooted cultural, religious, and social barriers in addressing gender inequalities and silent sexual violence issues in the modern Kurdish patriarchal society

Evaluation of heavy metal content of some lipsticks in Iran market

This study quantitatively estimated heavy metals as cadmium, lead, chromium and nickel (Cd, Pb, Cr and Ni) using flame atomic absorption spectrometry (FAAS) in ten lipstick products sold by local markets in Sari, Mazandaran State, Iran. All the samples were digested in HNO3 and HClO4 and then evaluated for heavy metal contents. All the concentrations are mean value of triplicate experiments for each sample. Analysis of variance (ANOVA) and Tukey post-hoc tests were used to determine significant variations in heavy metal contents and p < 0.05 was considered as significant. The determined range of cadmium, lead, chromium and nickel were 0.01-0.05&nbsp; g /g, 0.18-0.80&nbsp; g/g, 0.06-0.75 g/g, and 0.00-0.34 g/g, respectively. These results showed that nickel and cadmium contents were less than WHO and US FDA safe limit, while for chromium only one samples (No. 5) showed higher concentration than safe limit. The content of lead in all samples were lower than safe limit unless sample 6 which showed high level of lead

The Isaac Newton Telescope Monitoring Survey of Local Group Dwarf Galaxies. IV. The Star Formation History of Andromeda VII Derived from Long-period Variable Stars

We have examined the star formation history (SFH) of Andromeda VII (And VII), the brightest and most massive dwarf spheroidal (dSph) satellite of the Andromeda galaxy (M31). Although M31 is surrounded by several dSph companions with old stellar populations and low metallicity, it has a metal-rich stellar halo with an age of 6–8 Gyr. This indicates that any evolutionary association between the stellar halo of M31 and its dSph system is frail. Therefore, the question is whether And VII (a high-metallicity dSph located ~220 kpc from M31) can be associated with M31's young, metal-rich halo. Here we perform the first reconstruction of the SFH of And VII employing long-period variable (LPV) stars. As the most evolved asymptotic giant branch and red supergiant stars, the birth mass of LPVs can be determined by connecting their near-infrared photometry to theoretical evolutionary tracks. We found 55 LPV candidates within two half-light radii, using multiepoch imaging with the Isaac Newton Telescope in the i and V bands. Based on their birth mass function, the star formation rate (SFR) of And VII was obtained as a function of cosmic time. The main epoch of star formation occurred sime 6.2 Gyr ago with an SFR of 0.006 ± 0.002 M⊙ yr−1. Over the past 6 Gyr, we find slow star formation, which continued until 500 Myr ago with an SFR ~ 0.0005 ± 0.0002 M⊙ yr−1. We determined And VII's stellar mass M = (13.3 ± 5.3) × 106 M⊙ within a half-light radius {r}_{\tfrac{1}{2}}=3\buildrel{\,\prime}\over{.} 8\pm 0\buildrel{\,\prime}\over{.} 3 and metallicity Z = 0.0007, and we also derived its distance modulus of μ = 24.38 mag