The efficacy of Natural diatomaceous (DE) alone and combined with three fungal pathogens: Beauveria bassiana, Metarhizium anisopliae and Isaria fumosorosea against three moth species, Plodia interpunctella, Ephestia cautella and E. kuehniella was evaluated. Modified diatoms with Calcium hydroxide (Ca-DE) and modified diatoms with Sodium hydroxide (Na-DE) were the highlight treatments against tested insects and achieved the highest mortality percentages. E. kuehniella achieved the highest tolerant to tested DEs. B. bassiana was the most effective fungus alone against the three tested insects. Ca-DE and Na-DE treatments strongly enhanced the potency of the tested fungi. E. kuehniella was more susceptible to M. anisopliae and B. bassiana. Larvae of P. interpunctella and E. cautella were more tolerant to I. fumosorosea alone than E. kuehniella. In most cases, DE combinations with tested fungi had synergistic effects, while in E. cautella, modified diatoms with Aluminium hydroxide (Al-DE) decreased the efficacy of M. anisopliae and I. fumosorosea. Also, Al-DE and DE impaired the efficacy of I. fumosorosea against E. kuehniella. The egg production was highly suppressed by combination of Ca-DE followed by Na-DE with tested fungi in comparison to untreated control. The combination of Ca-DE/Beauveria bassiana strongly suppressed the number of deposited eggs of P. interpunctella (54.6±5.8 eggs/female), in comparison to untreated control (288.3±3.4 eggs/female).The most effective DEs modification were Ca-DE and Na-DE had insecticidal, repellent and ovicidal effects against tested insects and they had synergistic effects on the potency of tested fungi.

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Fire performance of polypropylene (PP) containing different percentages of ammonium polyphosphate (APP) with montmorillonite (Mt) or treated montmorillonite (MtT) was carried out by using the cone calorimeter test (CCT). Different samples from ammonium polyphosphate and montmorillonite were mixed with 90% polypropylene. The characterization of the prepared samples indicates that there is incorporation between the components of the samples. Heat release rate (HRR), peak heat release rate (PHRR), average heat release rate (Av-HRR), and time to ignition (TTI) of the samples were obtained from the cone calorimeter test. Also, the fire performance index (FPI) and the fire growth rate (FIGRA) were calculated. The interpretation of the curves and the parameters results from the cone calorimeter test which indicates that the addition of montmorillonite to APP increases its action as a flame retardant for PP. Moreover, the samples contain acid treatment montmorillonite showed an increase in the efficiency of ammonium polyphosphate when used. This result may be due to an increase in the SiO2 content by acid treatment.

KEYWORDSCerium phosphate, CePO4, nanoparticles with hexagonal or monoclinic phase was synthesized by the reaction between Ce(SO4)2.4H2O and two different phosphate sources, H3PO4 and Na2HPO4. The obtained gel was dried and calcined at different temperatures (200, 400, and 800 о C). The effects of the precursor materials and the calcination temperatures on the produced phases were studied. Both X-ray diffraction (XRD) and infrared spectroscopy (IR) were used to follow the changes in the phase structure for the produced samples. The thermal behaviour of the as prepared samples was studied by using differential scanning calorimetric (DSC) and thermogravimetric analysis (TGA). The morphology, crystallinity and particle size of the produced samples as prepared and calcinated were characterized by transmission electron microscope (TEM). The analysis of TEM results indicated that CePO4 was prepared in nano-sized particles.Cerium phosphate Synthesis X-ray diffraction IR DSC/TGA TEM

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T HIS study demonstrates the utilization of phosphogypsum waste for preparation of hydroxyapatite, lanthanum-doped hydroxyapatite and cerium-doped hydroxyapatite. Three concentrations of doping for each rare earth elements were prepared (0.25, 0.5, 0.75 weight %) respectively to be used as nanoparticles fillers additive to enhance the antibacterial activity, mechanical properties and bioactivity of conventional polymethyl methacrylate based bone cements. The prepared nanoparticles fillers are incorporated manually in 20 weight % to conventional polymethyl methacrylate bone cement to achieve polymethyl methacrylate cement composites. The results revealed that cerium-doped in 0.5 weight % with hydroxyapatite / polymethyl methacrylate cement composite permits remarkable increase in antibacterial activity against Staphylococcus aureus, while preserving a reasonably adequate compressive strength, and showed much higher calcium and phosphorus ions release (P-value ≤ 0.05). Within limitation of this study, the results are indicating the opportunity of the innovative bone cement for dental and orthopedic applications.

The main purpose of this work was to boost the surface and adsorption characteristics of diatomite (D) through chemical modifications with chitosan (DC), chitosan/titanium isopropoxide (DCTi), or chitosan/ graphene oxide (DCGr), respectively. Physicochemical characteristics of the prepared samples were investigated using SEM, TEM, XRD, FTIR, TGA, and porosity measurements. The impact of such modifiers into the D surface on the removal efficiency of chromium (VI) ions and methylene blue dye was studied in an equilibrium mode. Langmuir and Freundlich isotherms were used to analyze the adsorption data. Modifiers considerably enhanced the surface and textural properties of D through insertion of the main surface functional groups of chitosan and graphene oxide together compared to chitosan and titanium isopropoxide together or chitosan alone. In addition, the total surface area and total pore volume parameters of the unmodified D sample were improved greatly from 16.5 m2/g, 0.036 cm3/g to 39.8 m2/g and 0.174 cm3/g for DCGr, while they were 17.7 m2/g and 0.132 cm3/g for DC. The best adsorption results were well-defined with the Langmuir isotherm equilibrium model. Accordingly, the DCGr sample exhibited the highest uptake of Cr(VI) (about 167 mg/g) and methylene blue (66.7 mg/g). Hence, the chemical modification strategy of diatomite performed by using chitosan and graphene oxide significantly boosted the surface active sites and porosity properties and thus gave rise to the high adsorption capacity of Cr(VI) and methylene blue dye from wastewater. Hence, these findings affirmed the validity of the current strategy for surface modification of diatomite with chitosan and graphene oxide.

To study the effects of the precursor materials on the structure, the morphology, and the thermal stability of Mg(OH)2 particles, five samples were prepared by using the same method. The produced powder was characterized by using FTIR, XRD, SEM, and TEM, and the thermal stability was studied by using the thermogravimetric analysis. This study aims to use the advantage prepared material as a flame-retardant for the polymeric materials. The characterization of the obtained samples shows that Mg(OH)2 is formed in hexagonal phase and arranged in different shapes. The analysis of the data obtained from the TGA shows that Mg(OH)2 in general decomposed in three steps, the first one due to the water content and the other volatile materials, the second step represents the decomposition of Mg(OH)2 to produce MgO, and the third step represents the conversion of MgO to glassy layer. The samples prepared in presence of the surfactants gave a higher value for the formation of the glassy layer so that it is recommended to use this sample as flame retardant for the polymeric materials.