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فهرست مطالب نویسنده:

javad safari

  • داود مافی غلامی*، جواد صفری، ابوالفضل جعفری

    باتوجه به اهمیت وجود اطلاعات کافی و دقیق از ویژگی های ساختاری مانگروها برای احیاء و توسعه این رویشگاه ها، پژوهش پیش رو به تجزیه و تحلیل و نقشه سازی ویژگی های ساختاری مانگروهای ذخیره گاه زیست کره حرا پرداخته است. بدین منظور با آماربرداری (32 قطعه نمونه با ابعاد 45×45 متر) و ثبت مقادیر قطر تنه در محل یقه، ارتفاع درخت و قطر و ارتفاع تاج در قطعات نمونه و نیز تجزیه و تحلیل رابطه میان مقادیر این مشخصه ها با تصاویر ماهواره لندست 8 سال 2019، ویژگی های ساختاری فرم های رویشگاهی ذخیره گاه نقشه سازی شد. نتایج نشان داد که بین میانگین قطر تنه در محل یقه، ارتفاع درخت، ارتفاع تاج، قطر تاج و مساحت تاج در فرم های رویشگاهی ساحلی و جزیره ای در سطح اطمینان 95 درصد اختلاف معنی دار وجود داشت. نتایج نقشه سازی تغییرات مکانی مشخصه رویشی قطر درختان نشان داد که مقادیر قطر درختان از 7 تا 3/82 سانتی متر در فرم رویشگاهی جزیره ای و از 5/7  تا 2/86 سانتی متر در فرم رویشگاهی ساحلی و ارتفاع درختان نیز از 3/115 تا 1/648 سانتی متر در فرم رویشگاهی جزیره ای و از 2/121 تا 5/675 سانتی متر در فرم رویشگاهی ساحلی متغیر بود. همچنین، نتایج نشان داد که به دلیل تمرکز فرم ساختاری مانگروهای بلند قد و کوتاه قد در گستره های رو به دریا و خشکی ذخیره گاه، به ترتیب بیشترین و کمترین مقادیر مشخصه های رویشی در این حاشیه های ذخیره گاه قرار دارند. نتایج این پژوهش با نقشه سازی مکانی ویژگی ها و درجه توسعه ساختاری فرم های رویشگاهی ذخیره گاه زیست کره حرا، اطلاعات ضروری و مورد نیاز برای اولویت بندی مکانی برنامه های حفاظت و احیای این رویشگاه را فراهم کرده است.

    کلید واژگان: آماربرداری زمینی، مانگرو، گستره روبه خشکی، گستره روبه دریا
    Davood Mafi-Gholami*, Javad Safari, Abolfazl Jaafari

    Given the importance of availability sufficient and accurate information on the structural characteristics of mangroves to develop conservation and restoration programs for these ecosystems, this study investigates and maps the structural characteristics of the coastal and island forms of the mangroves in the Hara Biosphere Reserve. To this end, through a field inventory (32 sample plots with the area of 45 × 45 m) and recording diameter values at the collar location, tree height and diameter and crown height in the sample plots as well as analyzing the relationship between the values of these characteristics using Landsat 8 satellite images of 2019, the structural properties of the habitat forms of the reserve were mapped. The results showed that there was a significant difference between the mean values of diameter, height, canopy height, canopy diameter and area of the canopy in coastal and island form at a 95% level that indicates a higher degree of the structural development of the coastal form than the island form. The results of mapping the spatial variability of tree diameter showed that the trees had a diameter of 7 to 82.3 cm in island vegetation form and from 7.5 to 86.2 cm in coastal vegetation form and height of trees from 113.3 to 1.1. 648 cm in island habitat form and from 121.2 to 675.5 cm in coastal habitat form. The results also showed that due to the concentration of Tall and Dwarf mangroves in the seaward and landward areas of the Hara Biosphere Reserve, the highest and lowest values of vegetative characteristics were in the margins of the reserve, respectively. Spatial mapping of features and degree of the structural development of habitat forms of the mangrove in the Hara Biosphere Reserve provided the necessary information needed for spatial prioritization of conservation and restoration plans.

    Keywords: Field inventory, mangrove, landward area, seaward area
  • Zahra Shokrani, Zohre Zarnegar *, Javad Safari

    An efficient methodology for the preparation of 2-aminothiazoles is achieved by one-pot reaction of methylcarbonyls, thiourea and iodine in the presence of an aluminum oxide nanoparticle as an active nanocatalyst at 85 °C in DMSO solvent. Al2O3 nanoparticles have been prepared via co-precipitation method and their structures were confirmed using Fourier transform infrared radiation (FT-TR), X-ray diffraction (XRD), scanning electron microscopic (SEM), and energy-dispersive analysis of X-ray (EDAX) analyses. Advantages of this efficient synthetic approach include higher purity and excellent yield of products, easy isolation of products and convenient manipulation.

    Keywords: 3-Thiazoles, Al2O3 nanoparticles, Methylcarbonyls, One-pot synthesis, Heterogeneous catalyst
  • Javad Safari, Majid Ahmadzadeh, Zohre Zarnegar *

    In the present study, an attempt has been made to synthesize 3-methyl-4-arylmethylene isoxazole-5(4H)-one derivatives through sonication of hydroxylamine hydrochloride, ethyl acetoacetate and benzaldehyde derivatives in the presence of imidazole as a novel and effective catalyst in aqueous media. This green reaction under ultrasound irradiation has advantageous compared to conventional procedures in view of its shorter reaction times, high isolated yields, avoidance of using organic solvents, simple experimental procedure and workup and energy conservation. A combination of the advantages of ultrasound irradiation, homogeneous catalyst and aqueous media provides an important methodology for carrying out catalytic transformations.

    Keywords: Isoxazoles, Ultrasound irradiation, Imidazole, Catalyst, Water
  • Javad Safari *, Hassan Karbasizadeh, Sayed Hossein Banitaba

    A series of N alkyl 2 ketomethylquinoline derivatives were synthesis by reaction of benzoyl chloride derivatives with N methyl quinaldine iodide in the presence of triethyl amine under microwave irradiation. Enaminone form of the product study by spectroscopy method. The result revealed the N alkyl 2 ketomethylquinoline the fixed enaminone tautomer.

    Keywords: N alkyl 2 ketomethylquinoline, Enaminone, triethyl amine, microwave irradiation, Solvent-free conditions
  • Javad Safari *, Hassan Karbasizadeh, Sayed Hossein Banitaba
    A series of N alkyl 2 ketomethylquinoline derivatives were synthesis by reaction of benzoyl chloride derivatives with N methyl quinaldine iodide in the presence of triethyl amine under microwave irradiation. Enaminone form of the product study by spectroscopy method. The result revealed the  N alkyl 2 ketomethylquinoline the fixed enaminone tautomer.
    Keywords: N alkyl 2 ketomethylquinoline, Enaminone, triethyl amine, Microwave irradiation, Solvent-free conditions
  • Javad Safari, Leila Javadian
    In this paper, Fe3O4-chitosan nanoparticles were prepared by the immobilization of chitosan on the surface of Fe3O4 nanoparticles. Then, the 5-substituted hydantoins were synthesized from the condensation of aldehyde derivatives, ammonium carbonate and zinc cyanide as a well-known cyanating agent by the magnetic Fe3O4-chitosan nanoparticles under neat conditions. Fe3O4-Chitosan nanocatalyst as a renewable hybrid catalyst was easily recovered by an external magnet and reused for 4 times without obvious drop in its catalytic activity. The purpose of this research was to provide an easy method for the synthesis of 5-substituted hydantoins in high yields and short reaction times by a robust and magnetic recoverable catalyst.
    Keywords: Fe3O4, Chitosan, Magnetic catalyst, Hydantoin, Zinc cyanide
  • Javad Safari, Zohre Zarnegar, Simin Naseh, Zahra Akbari
    A simple highly versatile and efficient sonochemical synthesis of 1,2,4,5-tetrasubstituted and 2,4,5-trisubstituted imidazoles is achieved by condensation of 1,2-dicarbonyl compound, aldehyde, ammonium acetate and primary amine using antimony trichloride immobilized on silica gel (SiO2-OSbCl2) as a catalyst in ethanol at moderate temperature. Operational simplicity, practicability and applicability to various substrates make this method an interesting alternative to previously applied procedures. From the environmental standpoint, this eco-friendly green catalyst is stable, highly active, easy to prepare and handle.
    Keywords: SiO2, OSbCl2, Lewis acid, Heterogeneous catalyst, Imidazoles, Sonication
  • Shiva Dehghan Khalili, Sayed Hossein Banitaba, Javad Safari
    A mild, efficient and environmentally friendly method has been developed for the green synthesis of 2,4,5-trisubstituted imidazoles via a three-component one-pot condensation of 1,2-diketones, diammonium hydrogen phosphate, (NH4)2HPO4(DAHP) and aryl aldehydes in waterunder reflux conditions. The DAHP shows remarkable activities for the synthesis of title compounds.The key advantages of this method toward conventional methods are experimental simplicity, good functional group tolerance; excellent yields, short routine, and selectivity without the need for a transition metal or base catalyst.
    Keywords: 2, 4, 5, Trisubstituted imidazoles, Diammonium hydrogen phosphate, Water, Three, component
  • Javad Safari, Soheila Gandomi, Ravandi, Zahra Akbari
    An efficient synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles by one-step condensation of an aldehyde, benzil, ammonium acetate and primary amine in the presence of nanocrystalline magnesium aluminate under microwave irradiation is described. The advantages of this catalyst are including simple work-up, low cost and reusability. Compared with conventional methods, the main advantages of the present procedure are its being a green method, its milder conditions, necessary shorter reaction time, and its higher yields and its selectivity. The structures of products were characterized by 1H NMR, 13C NMR, IR, elemental analyses, MS and UV spectral data. Their melting points were compared with literature report.
    Keywords: Nanocrystalline magnesium aluminate, Imidazoles, Solvent free, MW irradiation, Multi, component reaction
  • Javad Safari, Zohre Zarnegar
    Fe3O4 nanoparticles were prepared by chemical coprecipitation method and was found to be a mild and effective catalyst for the efficient, one-pot, three-component synthesis of 2,4,5-trisubstituted imidazoles at room temperature under ultrasound irradiation. The high yields of products and short reaction time were attributed to the nanosize of about 20 nm in which the catalyst could act as a nanoreactor. This methodology is found to be fairly general and catalyst is easily separated by magnetic devices and can be reused without any apparent loss of activity for the reaction.
    Keywords: Fe3O4 nanoparticles, Imidazole, Heterogeneous catalyst, Ultrasound irradiation
  • Javad Safari *, Hassan Karbasizadeh, Sayed Hossein Banitaba
    A series of N alkyl 2 ketomethylquinoline derivatives were synthesis by reaction of benzoyl chloride derivatives with N methyl quinaldine iodide in the presence of triethyl amine under microwave irradiation. Enaminone form of the product study by spectroscopy method. The result revealed the  N alkyl 2 ketomethylquinoline the fixed enaminone tautomer.
    Keywords: N alkyl 2 ketomethylquinoline, Enaminone, triethyl amine, Microwave irradiation, Solvent-free conditions
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