Magnesium hydroxide/melamine phosphate borate (nano MH/MPB), a novel nano-composition intumescent flame retardant, was synthesized with the in-situ reaction method from MgCl2·6H2O sodium hydroxide (NaOH) and melamine phosphate borate (MPB) in the absence of H2O. The structure of the product was confirmed by EDAX IR and XRD. The effects of reaction temperature and time on the dimension of magnesium hydroxide were observed. The effects of mass ratio of magnesium hydroxide to MPB on the flame retardancy of nano-MH/MPB/EP were examined with the limiting oxygen test. The results show that the optimal condition of synthesis of MH/MPB is mMH/mMPB = 0.25, reacting under 75 ℃ for 30 minutes. Finally, the mechanism for flame retardancy of nano-MH/MPB/EP was pilot studied by means of IR of char layer and TG of MH/MPB.
Dust is one of the atmospheric pollutants that have adverse environmental effects and consequences. Dust fall contains particles of 100 microns or even smaller ones, which fall from the atmosphere onto the earth surface. The aim of this study is to determine the concentration of lead in dust fall samples in order to study the pollution level of this element in Zahedan, Sistan and Baluchistan Province, Iran. Therefore, sampling was carried out using 30 marble dust collectors (MDCO) for 3 months in the spring of 2015 to investigate the quantitative variation and spatial analysis of lead content in dust fall. These dust collectors were placed at 30 stations on the building roofs with a height of approximately 1.5 meters across the city. According to the results, the mean lead concentration in the spring was 90.16 mg/kg. In addition, the zoning map of lead content shows that the lowest level of lead was measured at Imam Khomeini station while the highest amount of lead appeared in Mostafa Khomeini station.
New hybrid magnetic materials based on HDPE filled with Со and Ni nanoparticles have been prepared via the metal vapor synthesis. Properties of the metal-polymer composites have been elucidated as a function of MVS parameters and metal nature. The Faraday method has been applied to characterize the magnetic properties of the systems. The microstructure of the samples has been studied with a number of X-ray and synchrotron techniques, including XRD, EXAFS and SAXS. Core-level and valence band spectra were measured by XPS. The peak at binding energy of 282.8 eV characteristic of C-Ni bond was recorded in the C 1s spectrum. It was shown that properties of nanocomposite materials with similar compositions are determined both by the synthesis conditions and post-synthesis factors.
Marine geological maps of the Campania region have been constructed both to a 1:25.000 and to a 1:10.000 scale in the frame of the research projects financed by the Italian National Geological Survey, focusing, in particular, on the Gulf of Naples (Southern Tyrrhenian Sea), a complex volcanic area where volcanic and sedimentary processes strongly interacted during the Late Quaternary and on the Cilento Promontory offshore. In this paper, the examples of the geological sheets n. 464 “Isola di Ischia” and n. 502 “Agropoli” have been studied. The integration of the geological maps with the seismo-stratigraphic setting of the study areas has also been performed based on the realization of interpreted seismic profiles, providing interesting data on the geological setting of the subsurface. The coastal geological sedimentation in the Ischia and Agropoli offshore has been studied in detail. The mapped geological units are represented by: i) the rocky units of the acoustic basement (volcanic and/or sedimentary); ii) the deposits of the littoral environment, including the deposits of submerged beach and the deposits of toe of coastal cliff; iii) the deposits of the inner shelf environment, including the inner shelf deposits and the bioclastic deposits; iv) the deposits of the outer shelf environment, including the clastic deposits and the bioclastic deposits; v) the lowstand system tract; vi) the Pleistocene relict marine units; vii) different volcanic units in Pleistocene age. The seismo-stratigraphic data, coupled with the sedimentological and environmental data provided by the geological maps, provided us with new insights on the geologic evolution of this area during the Late Quaternary.
This study adopts a discursive and analytical perspective to explore how technological advances are reconfiguring the dynamics of the global labour market, with special attention to the phenomenon of microwork. Microwork, characterised by short, fragmented tasks carried out through digital platforms and geographically distributed, has seen exponential growth, particularly in nations with lower economic development. This type of work shows a growing distinction between tasks of a complex and creative nature and those of a repetitive and monotonous nature that do not require advanced skills to perform. This differentiation can intensify wage disparities between developed and developing countries, as well as contribute to the precariousness of work in activities considered less complex and valued. The article highlights the emergence of unstable and poorly paid jobs that do not require specific qualifications and discusses their impact on social security systems in countries where labour regulations are insufficient. Using a theoretical-methodological approach, the research examines the role of artificial intelligence in the rise of micro-labour and its socio-economic implications. It concludes that despite the flexibility and short-term earning opportunities offered by microwork, it poses considerable challenges in terms of income security, workers’ rights, and social protection, emphasising the need for regulatory measures to mitigate its adverse effects on vulnerable communities.
Cysteine is one of the body’s essential amino acids to build proteins. For the early diagnosis of a number of diseases and biological issues, L-cysteine (L-Cys) is essential. Our study presents an electrochemical sensor that detects L-cysteine by immobilizing the horseradish peroxidase (HRP) enzyme on a reduced graphene oxide (GCE) modified glassy carbon electrode. The morphologies and chemical compositions of synthesized materials were examined using Fourier transform infrared spectroscopy (FTIR) and field-emission scanning electron microscopy (FESEM). The modified electrode’s electrochemical behavior was investigated using cyclic voltammetry (CV). Cyclic voltammetry demonstrated HRP/rGO/GCE has better electrocatalytic activity than bare GCE in the oxidation of L-cysteine oxidation in a solution of acetate buffer. The electrochemical sensor had a broad linear range of 0 µM to 1 mM, a 0.32 µM detection limit, and a sensitivity of 6.08 μA μM−1 cm−2. The developed sensor was successfully used for the L-cysteine detection in a real blood sample with good results.
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