1,461 research outputs found

    Using of Chroococcus SP. to Treat Polluted Water with Cadmium & Nickel

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    Chroococcus sp. was exposed to different concentrations 0.3, 0.5, 1, 2, 3, 4, 5, 6 and 7 ppm, from cadmium and nickel. The results revealed that the ability of the alga to remove cadmium and nickel was increased with the increase of the metal concentration which the alga exposed to them and this case does not record before. This may relate to mechanisms of adsorption and removal which not understood perfectly till now according to many researches that concerned with this field of studies. It was noticed that the removal percentage of cadmium reaches to 77.66 & 76% in the two higher concentrations 6 & 7 ppm, which exposed to the alga till the last day (twelve days) from the experiment, but same percentage (77.66 & 76%) was recorded on the eighth day of the experiment to remove nickel and decrease to 12.5 & 28% on the last day of the experiment for the above two concentrations

    X-Ray Spectral Study of AGN Sources Content in Some Deep Extragalactic XMM-Newton Fields

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    We undertake a spectral study of a sample of bright X-ray sources taken from six XMM-Newton fields at high galactic latitudes, where AGN are the most populous class. These six fields were chosen such that the observation had an exposure time more than 60 ksec, had data from the EPIC-pn detector in the full-Frame mode and lying at high galactic latitude b>25o|b| > 25^o . The analysis started by fitting the spectra of all sources with an absorbed power-law model, and then we fitted all the spectra with an absorbed power-law with a low energy black-body component model.The sources for which we added a black body gave an F-test probability of 0.01 or less (i.e. at 99% confidence level), were recognized as sources that display soft excess. We perform a comparative analysis of soft excess spectral parameters with respect to the underlying power-law one for sources that satisfy this criterion. Those sources, that do not show evidence for a soft excess, based on the F-test probability at a 99% confidence level, were also fitted with the absorbed power-law with a low energy black-body component model with the black-body temperature fixed at 0.1 and 0.2 keV. We establish upper limits on the soft excess flux for those sources at these two temperatures. Finally we have made use of Aladdin interactive sky atlas and matching with NASA/IPAC Extragalactic Database (NED) to identify the X-ray sources in our sample. For those sources which are identified in the NED catalogue, we make a comparative study of the soft excess phenomenon for different types of systems

    Compatibility between the endoparasitoid Hyposoter didymator and the entomopathogenic fungus Metarhizium brunneum: A laboratory simulation for the simultaneous use to control Spodoptera littoralis

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    BACKGROUND The cotton leafworm, Spodoptera littoralis, is one of the most destructive pests in the Mediterranean basin, being predominantly controlled using synthetic chemical pesticides. Strain EAMa 01/58‐Su of the fungus Metarhizium brunneum and the parasitoid Hyposoter didymator are promising biological control agents for this pest. In this study, we assessed the compatibility between these two agents to control S. littoralis under joint attack scenarios. RESULTS Firstly, the direct and indirect effects of the fungus towards parasitoid adults were studied. The fungus significantly decreased life expectancy of the parasitoid (mortality=62.5%; mean lethal concentration=1.85×106 conidia ml‐1; average survival time=92.2h) when applied at high concentrations (108 conidia ml‐1), whereas it did not affect the reproductive potential of the parasitoid females during the three days after treatment. Secondly, the combinations between the two agents to control S. littoralis under different simultaneous use scenarios (inoculation of S. littoralis larvae with the fungus before being exposed to parasitoid females and vice versa) were investigated, with additive effect in all cases. A significant effect on fitness (preimaginal development time and reproductive potential) of the F1 parasitoid generation were detected. Moreover, parasitization significantly reduced the total haemocytes in S. littoralis haemolymph compared with the control, promoting fungal infection. Finally, parasitoids showed a significant preference for non‐inoculated S. littoralis larvae. CONCLUSIONS We demonstrated compatibility (additive effect) between fungus and parasitoid under different joint attack scenarios to control S. littoralis in laboratory conditions. However, this will be supported by our ongoing greenhouse and field studies

    Morphological assessment of Niger Kuri cattle using multivariate methods

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    A total of 406 adult cows and 34 bulls belonging to the Niger Kuri cattle population were assessed for 16 body measurements and 11 qualitative traits to contribute to the characterization of this unique cattle breed. Body measurements included facial, horn, ear and rump lengths; facial, cranial, shoulder, pelvic and ischium widths; height at withers and at hips; muzzle circumference; heart girth; body and tail lengths; and thorax depth. Qualitative traits included cephalic profile, ear shape, muzzle pigmentation, eyelid pigmentation, hoof pigmentation, horn colour, dewlap size, backline profile, horn shape, spotting pattern, and coat colour pattern. Data were analysed jointly with 377 individuals from four other West African taurine cattle breeds (N’Dama, Lagunaire, Lobi and Somba) using multivariate statistical methods, including canonical and correspondence analyses. Among the breeds analysed, Kuri cattle had the highest mean values for all body measurements: height at withers and body length had mean values of 124.0 ± 0.4 and 146.8 ± 1.0 cm in Kuri cows, respectively, and 126.0 ± 2.2 and 155.7 ± 3.6 cm, respectively, in Kuri bulls. Canonical analysis allowed the construction of contour plots to illustrate the high differentiation between Kuri cattle and the other breeds, regardless of the sex of the individuals. Further, the Mahalanobis distance matrices showed that pairs involving Kuri cattle had the higher differentiation of these populations. Correspondence analysis carried out on these 11 qualitative traits allowed the researchers to ascertain a clear differentiation between the Kuri and the other taurine cattle breeds. The N’Dama, Lagunaire, Lobi, and Somba breeds did not show clear differentiation at qualitative-type trait level with 75% confidence regions computed for these four breeds being highly intermingled. In the current data, Kuri cattle had the highest frequency in qualitative features, such as concave cephalic profile, dropped ears, non-pigmented muzzle and grey-coloured horns, which are absent in West African taurine and zebu cattle breeds, according to the literature. The current evidence would suggest that unique Kuri cattle type features may result from breeding decisions rather than from zebu admixture. This work confirms that at type trait level Kuri cattle is a unique population within the West African taurine cattle group. The implementation of genetic analyses aiming at ascertaining the degree of uniqueness of the breed is advised.Keywords: Body measurements, Bos taurus, multivariate analyses, qualitative traits, West African cattl

    Effects of sand and gating architecture on the performance of foot valve lever casting components used in pump industries

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    Funding Information: The authors thank Kalasalingam Academy of Research and Education, Krishnankoil for providing the facilities for various tests and characterizations. The King Saud University authors extend their appreciation to the Deanship of Scientific Research at King Saud University for funding the work through the research group project no. RG-148. This Research was funded by King Mongkut's University of Technology North Bangkok has received funding support from the National Science, Research and Innovation Fund (NSRF) (Grant No. KMUTNB-MHESI-64-16.1). Publisher Copyright: © 2021 The Author(s)This work addresses manufacture, testing and simulation of foot valve lever (FVL) for monoblock pump industry, using a cost-effective casting design process. The impact of different types of sands, such as air-set, dry and sodium silicate as well as gating designs, namely H-, U- and O-type, were studied with respect to surface roughness and porosity. The mold pattern was produced using additive manufacturing (AM) technology. Both experimental and numerical investigations were performed on the temperature distribution of molten metal at random locations for the different gating configurations or designs, considering mold filling and solidification. It was evident from the experimental investigation that contribution of air-set sand and O-type gating architecture showed limited consistency effects. Importantly, gating architecture was the most influential parameter to determine all specified quality outcomes, independent of sand mold. An order of O < H < U-type was obtained from the gating designs for minimal surface roughness and percentage of porosity. Furthermore, the microstructure analysis depicted only an irregular defect with minimum quantity at both surface and cross-section of O-type at two different locations. Optimum pouring temperatures of 740, 750 and 790 °C were obtained for mold filling of all 24 components of H-, O- and U-type of gating designs, respectively. The varying solidification temperature was observed from real time thermocouple reading, which was in close agreement with the numerical simulation. Evidently, O-type of gating design exhibited best performance for large-scale development of the FVL in terms of surface roughness, porosity and cooling effects.Peer reviewe
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