The impact of different preservation procedures, including formalin fixation, ethanol preservation, and freezing, on the morphometric traits of fish preserved in museum specimens is tested in three different cichlid species: Oreochromis aureus (Steindachner, 1864), Coptodon zillii (Gervais, 1848), and Oreochromis niloticus (Linnaeus, 1758). The primary goal was to determine morphometric differences resulting from these procedures and identify correction values to reconstruct the original dimensions of the body. Our results support that shrinkage of morphological variables, such as total length (TL), standard length (SL),and head length (HL), is present in the three methods tested, depending on species, measurement, and treatment. This shrinkage is also supported by a least-squares regression analysis showing that length loss increases proportionally with larger fish sizes for the species under study. These findings are important as they confirm the differences observed among preservatives in all species, supporting the argument against significant morphometric biases related to freezing, while suggesting that standardized protocols be used with fixatives. These findings not only offer directions for those working with fish collections but also highlight the need for thorough documentation of preservation methods, in order to help future taxonomical and ecological research in ichthyology
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In this work, metal oxide nanostructures, mainly copper oxide (CuO), nickel oxide (NiO), titanium dioxide (TiO2), and multilayer structure, were synthesized by the DC reactive magnetron sputtering technique. The effect of deposition time on the spectroscopic characteristics, as well as on the nanoparticle size, was determined. A long deposition time allows more metal atoms sputtered from the target to bond to oxygen atoms and form CuO, NiO, or TiO2 molecules deposited as thin films on glass substrates. The structural characteristics of the final samples showed high structural purity as no other compounds than CuO, NiO, and TiO2 were found in the final samples. Also, the prepared multilayer structures did not show new compounds other than th
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Biodiesel is an environmentally friendly fuel and a good substitution for the fossil fuel. However, the purity of this fuel is a major concern that challenges researchers. In this study, a calcium oxide based catalyst has been prepared from local waste eggshells by the calcination method and tested in production biodiesel. The eggshells were powdered and calcined at different temperatures (700, 750, 800, 850 and 900 °C) and periods of time (1, 2, 3, 4 and 5 hr.). The effect of calcination temperature and calcination time on the structure and activity of the solid catalyst were examined by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Brunaure-Emmett-Teller (BET). The optimum catalyst performance was obtained at 900 °C
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The extraction of Eucalyptus oil from Iraqi Eucalyptus Camadulensis leaves was studded using water distillation methods. The amount of Eucalyptus oil has been determined in a variety of extraction temperature and agitation speed. The effect of water to Eucalyptus leaves (solvent to solid) ratio and particle size of Eucalyptus leaves has been studied in order to evaluate the amount of Eucalyptus oil. The optimum experimental condition for the Eucalyptus oil extraction was established as follows: 100˚C extraction temperature, 200 rpm agitation speed; 0.5 cm leave particle size and 6:1 ml: g amount of water to eucalyptus leaves Ratio.
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