2,115 research outputs found

    Some biological aspects of four marine fish species in Iraqi marine waters, northwest Arabian Gulf

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    The study described some biological characteristics of four commercially important fish species in Iraqi marine waters including Planiliza klunzengeri, P. subviridis, Acanthopagrus arabicus and Otolithes ruber from February 2020 to January 2021. The length and weight of individual fish caught were measured. The length-weight relationships were W= 0.027L2.715 for P. klunzengeri,  W= 0.034L2.670 for P. subviridis,  W= 0.030L2.867 for A. arabicus and W= 0.023L2.755 for O. ruber, and all species indicated negative allometric growth. The lower values of the relative condition factor (Kn) were found at the mid-lengths of P. klunzingeri and P. subviridis, and the large individuals for A. arabicus and O. ruber. Scales were used for age determination and measurements, and the back-calculated lengths-at-ages were calculated using the body proportional formula. Asymptotic total lengths (L∞) estimated were 29.6, 32.8, 44.9 and 70.6 cm for P. klunzengeri, P. subviridis, A. arabicus and O. ruber, respectively. These results could assist in fisheries management for the sustainable exploitation of these commercially important species in Iraqi marine waters

    Antifungal and Antioxidant Activity of Asteriscus graveolens subsp. odorus Essential Oil

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    The essential oil of air-dried Asteriscus graveolens subsp. odorus, plant of southern Morocco, obtained by hydrodistillation were analysed by capillary gas chromatography-mass spectrometry (GC-MS). Twenty eight compound accounting 69.14% of the total oil was identified. The oxygenated sesquiterpenes 6-oxocyclonerolidol (30.72%) and epi-?-cadinol (14.50%) were the main constituents. The essential oil was tested for antifungal activity through mycelial growth inhibition tests in vitro against three agricultural pathogenic fungi: Penicillium digitatum, P. expansum and Botrytis cinerea. The essential oil at 125, 150, 200, 250, 500, 1000 and 2000 ppm was highly effective against mycelial growth of P. digitatum with 100% inhibition from the first day of incubation. Complete inhibition was also observed at 150, 200, 250, 500, 1000 and 2000 ppm concentrations of the essential oil from the first day of incubation for P. expansum. The doses 500, 1000 and 2000 ppm showed a percentage inhibition of 100% from day one for B. cinerea. Asteriscus graveolens subsp. odorus essential oil was also tested at different concentrations on Citrus fruits (Citrus reticulata Blanco cv. Nules) inoculated with P. digitatum (105 conidia ml-1, giving a fungistatic or fungicidal effect. In addition, the oil was subjected to screening for its possible antioxidant activity. For that, the in vitro assay based on the scavenging of the stable radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) was used. The Asteriscus graveolens subsp. odorus essential oil gave a value of CI50 0.2498 mg/ml. It inhibition percentage of free radical was slightly lower than that of BHT (the control compound) for all concentrations used. Our findings demonstrate that Asteriscus graveolens subsp. odorus essential oil possesses antioxidant and antifungal activities that might be a natural potential source of preservative and antifungal compounds used in food, in cosmetics and in pharmaceuticals products. Keywords: Medicinal plant, antifungal activity, antioxidant activity, citrus fruits, natural product

    Abundant soliton solution for the time-fractional stochastic Gray-Scot model under the influence of noise and M-truncated derivative

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    In this study, we investigate the abundant soliton solutions for the time-fractional stochastic Gray-Scot (TFSGS) model analytically. The Gray-Scot model is considered under the influence of M-truncated derivative and multiplicative time noise. This is a reaction–diffusion chemical concentration model that explains the irreversible chemical reaction process. The M-truncated derivative is applied for the fractional version while Brownian motion is taken in the sense of time noise. The novel mathematical technique is used to obtain the abundant families of soliton solutions. These solutions are explored in the form of shock, complicated solitary-shock, shock-singular, and periodic-singular types of single and combination wave structures. During the derivation, the rational solutions also appear. Moreover, we use MATHEMATICA 11.1 tools to plot our solutions and exhibit several three-dimensional, two-dimensional, and their corresponding contour graphs to show the fractional derivative and Brownian motion impact on the soliton solutions of the TFSGS model. We show that the TFDGS model solutions are stabilized at around zero by the multiplicative Brownian motion. These wave solutions represent the chemical concentrations of the reactants

    Characterization of Niti Super Elasticity Shape Memory Alloys

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    Ni-Ti samples were prepared by powder metallurgy. The prepared samples were master samples M1 (55% Ni- 45%Ti) and M2 (56% Ni- 44%Ti). The additive percentage of Ta was 5%, 7% and 9% to master sample M1 and M2, while Nb addition was 1%, 2% and 4% to M1 and M2. The pressure of pressing was 800 Mpa. The samples were sintered at 950 °C for a time of 9 hr. Samples were then examined by using SEM technique, XRD, DSC, Vickers hardness. The porosity was measured according to Archimedes method. Scanning electronic microscopy images showed that most prepared samples have porosity, which in turn imparts decreasing microhardness values across the surface. Better increase of microhardness values is found in M2+5%Ta. Scanning electron microscopy indicated also the best martensitic structure in M1+4% Nb and M2+4%Nb. X-ray diffraction observations indicated that NiTi, Ni3Ti and NiTi2 phases exist in all samples. NiTi phase is playing a dramatic role in enhancing shape memory effect and superelasticity. DSC results show that transformation temperatures range in (46-134°C). This indicates that all samples at room temperature have one phase which is martensite

    Chemical Composition and Anticandidal Effect of Three Thymus Species Essential Oils from Southwest of Morocco against the Emerging Nosocomial Fluconazole-Resistant Strains

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    The purpose of this present work is to study the essential oils composition of three endemic Thymus species from southwest of Morocco: Thymus satureioides Coss., Thymus pallidus Batt. and Thymus leptobotrys Murb., as well as their antifungal activity towards nineteen strains of emerging nosocomial Fluconazole-resistant Candida species. The chemical composition of the essential oils was determined by capillary gas chromatographic-mass spectrometry analysis. The results reveal qualitative and quantitative variation in composition of Thymus species. Seventy-three different compounds, 56 for T. satureioides accounting for 99.97% of the total essential oil, 52 for T. pallidus, accounting for 98.94% of the total essential oil, and 40 for T. leptobotrys accounting for 99.20%, were determined. The results obtained for the anticandidal disc-diffusion assay shows that the 19 strains of Candida species tested were inhibited by the Moroccan Thymus essential oils to a varying degree, with the diameters of the inhibition zone ranging from 49±1.00 to 85±1.15 mm. There were significant differences (p ? 0.05) in the antifungal activities of the essential oils on all species tested who showed larger inhibition zones than the positive control fluconazole and amphotericine B. Candida albicans showed a high sensitivity to essential oils of Thymus pallidus and Thymus leptobotrys compared with essential oil of Thymus satureioides and controls. While non- albicans Candida species showed less sensitivity to essential oils of Thymus pallidus and Thymus leptobotrys and are more sensitive to essential oils of Thymus satureioides than Candida albicans. Interestingly C. krusei, C. dubliniensis and C. glabrata were found to be resistant to conventional antifungal (fluconazole and amphotericine B), while our essential oils tested were able to inhibit the growth of Candida strains resistant to antifungal agents. The value of Minimal inhibitory concentration (MIC) and Minimal Fungicidal Concentration (MFC) of the Thymus essential oils studied ranges from 0.33 mg/mL to 0.91 mg/mL. All the essential oils possessed higher antifungal potential than classical fungicide. Keywords: Thymus species, essential oils, anticandidal activity, Nosocomial fluconazole-resistant strains

    Caracterización de los lodos de la depuradora de Sadat (Minufiya, Egipto) para la obtención de un material vitrocerámico

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    Muchos problemas ambientales actuales están relacionados con los desechos industriales y municipales (lodos de depuradora, etc.), debidos al gran volumen que se genera, así como a los elementos peligrosos que incluyen en ellos (metales pesados). Su almacenamiento, tratamiento y transporte conlleva también costos económicos. En Egipto en el año 2002 se generaron de 12 a 15 kg/año por habitante de materia sólida procedente de los lodos de depuradora. En la actualidad, el destino principal de estos lodos es su vertido en el desierto
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