92 research outputs found

    A Comparative Study on Spinel Iron-cobalt Oxide Prepared by Co-precipitation and Hydrothermal Routes

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    Spinel iron-cobalt oxide was synthetized by coprecipitation and hydrothermal process. The nanostruc-tures of the prepared samples were characterized as functions of the calcination temperature and the hy-drothermal synthesis time, using X-ray powder diffractometry (XRD) and nitrogen adsorption–desorption technique ( BET, BJH ). Using chloride salts as start materials and both of sodium hydroxide and ammo-nia as precipitating agents; The results show that the CoFe2O4 obtained has a mesoporous structure with a pore distribution strongly depending on the experimental conditions. The crystallite size and lattice pa-rameter showed a same variation as function of ( i ) the calcination temperature in the coprecipitation method, ( ii ) the synthesis time in the hydrothermal process. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3509

    Eco-friendly synthesis from industrial wastewater of Fe and Cu nanoparticles over NaX zeolite and activity in 4-nitrophenol reduction

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    We deposited Fe and Cu over zeolite NaX (Fe/NaX and Cu/NaX) by adsorption from effluent industrial wastewater. We synthesized the zeolite NaX by the hydrothermal method. 5g of NaX completely adsorbed 350 and 380mg of Fe and Cu from the industrial wastewater, respectively, in 6h. The distribution of Fe and Cu over the NaX was uniform and amounted at 14 and 18mass%, respectively. Fe and Cu modify the morphology of the NaX zeolite: the particle size increased from 9\uce\ubcm to 10\uce\ubcm for the former and decreased to 3\uce\ubcm for the latter. Fe/NaX and Cu/NaX are less crystalline than NaX. BET analysis showed that the specific surface area decreased by 30% and 50% compared to NaX for Fe/NaX and Cu/NaX, but the ratio between meso- and micropores increased by 7 and 13 times, respectively. Fe/NaX and Cu/NaX synthesized by adsorption from industrial wastewater reduced +99% of 4-p-nitrophenol to 4-aminophenol in less than 100s, which is comparable to noble metal

    Determinants of Employees’ Performance in Selected Business Sector in Palestine: Moderating role of Islamic Value System

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    This paper highlights relationship between servant leadership and employee performance and moderation of Islamic value system in selected Business Sector in Palestine.Employees’ performance is seemed to be related with factors like servant leadership, and Islamic value system, which were conceptually discussed.Overall, the present study offers a beneficial insight to the importance of servant leadership and value system from the view point of Islam and servant leadership behavior in business sector in order to attain excellent employee performance.Further, the results might help future research to study the effect of Islamic value system, servant leadership in producing other intended outcomes.This paper also highlights findings from its pilot study, preliminary discussion and recommendations are posted toward the end of this paper

    the forest vegetation of the tolfa ceriti mountains northern latium central italy

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    The Forest Vegetation of the Tolfa-Ceriti Mountains (Northern Latium - Central Italy)The forests of the Tolfa-Ceriti mountains (Latium, central Italy) were investigated through a phytosociological approach. 249 relevés were performed and treated with multivariate analysis. 13 woodland communities were identified, of which 7 belong toQuercetalia pubescenti-petraeae, 1 toFagetalia sylvaticae, 1 toPopuletaliaand 4 toQuercetalia ilicis. The thermophilous Turkey oak-forests occurring on the trachytic hills of the Ceriti Mountains and on the flysch substrates of the Tolfa Mountains were included inRubio peregrinae-Quercetum cerridisass. nova.Quercus cerrisandFraxinus angustifoliasubsp.oxycarpawoodland communities of the footslopes have been ascribed toFraxino oxycarpae-Quercetum cerridis, while the widespread mesophilus Turkey oak forests have been ascribed toMelico-Quercetum cerridis. Cephalantero longifoliae-Quercetum cerridishas been restricted to acid and oligotrophic soils.Quercus petraeawoodlands, occurring on trachytic substrates have been described as a new association namedCarici olbiensis-Quercetum petraeaeass. nova. All these mixed oak woods have been included in the allianceCrataego laevigatae-Quercion cerridisArrigoni 1997. The nomenclatural problems concerning the prior nameTeucrio siculi-Quercion cerridisUbaldi 1988 are also discussed. The beech forests of the higher altitudes have been included inFraxino orni-Fagetum sylvaticae, while theAlnus glutinosaravine woodlands have been described as belonging to the new associationPolysticho setiferi-Alnetum glutinosae. Secondary communities ofAcer monspessulanumandAcer campestredeveloped on flysch substrates, and ofErica arboreaandArbutus unedo(Erico-Arbutetum unedonis) developed on trachytic substrates, have also been identified. Finally two types ofQuercus ilexwood have been identified:Cyclamino repandi-Quercetum ilicis, on sandstones, and the new associationArbuto unedonis-Quercetum ilicisass. nova on volcanic soils. This latter community can be considered as a coenological and geographical vicariant in central Italy of the sicilianErico-Quercetum ilicis

    Analysis of forest fires causes and their motivations in northern Algeria: the Delphi method

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    Forest fires in Algeria are mostly human-caused and result from local social behavior, whether voluntary (arson) or involuntary (negligence). Understanding the reasons why fires start is, therefore, a crucial factor in preventing or reducing their incidence, developing significant prevention efforts and designing specific fire prevention campaigns. The Delphi method is a promising tool for improving knowledge about how fire starts and why, and above all helps reduce the number of fires started by unknown causes, the majority type in Algeria. The Delphi method uses a set of procedures for eliciting and refining the opinions of a panel of experts on a particular subject of interest. This method was used in three case studies, in coastal or inner wilayas (provinces) selected from a highly fire-prone area in north-central Algeria. Results showed the traditional use of fire in agriculture and forestry, in situations related to land use changes and in interpersonal conflicts are the major causes of voluntary fires. For involuntary events (negligence), experts unanimously identified the importance of the restart of fire, caused by fire crews who do not ensure the mopping up of controlled fires (91.49%) and the negligent use of agricultural fires, particularly stubble burning (80.14%). For voluntary fires (arson), results highlight the importance of fires set for land use changes (77.30%), pyromania (67.38%) and honey gathering (62.41%). Illegal dumping and burning of garbage was also mentioned by responders in all study-areas
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