Islamic Azad University North Tehran Branch

About: Islamic Azad University North Tehran Branch is a education organization based out in Tehran, Iran. It is known for research contribution in the topics: Adsorption & Catalysis. The organization has 868 authors who have published 968 publications receiving 9987 citations.

Poly[propane-1,3-diammonium [cuprate(II)-bis­(μ2-pyridine-2,3-dicarboxyl­ato)] trihydrate]

Abstract: The title polymeric compound {(C3H12N2)[Cu(C7H3NO4)2]·3H2O}n or {(pnH2)[Cu(py-2,3-dc)2]·3H2O}n (pn is propane-1,3-diamine and py-2,3-dcH2 is pyridine-2,3-dicarboxylic acid), was synthesized by reaction of copper(II) chloride dihydrate with a proton-transfer compound, propane-1,3-diammonium pyridine-2,3-dicarboxyl­ate or (pnH2)(py-2,3-dc), in aqueous solution. The anion is a six-coordinate complex (site symmetry \overline{1}), with a distorted octa­hedral geometry around CuII, consisting of two bidentate pyridine-2,3-dicarboxyl­ate groups and two O atoms of bridging ligands from (py-2,3-dc)2− fragments, which are located in trans positions. The (pnH2)2+ cation is disordered over two sites by the center of inversion. Inter­molecular hydrogen bonds, π–π [centroid–centroid distances of 3.539 (3) A] and C—O⋯π stacking inter­actions [O⋯Cg = 3.240 (5) A; Cg is the center of the pyridine ring], connect the various components into a supra­molecular structure.

Essential Oil Composition of the Endemic Species of Pycnocycla caespitosa Boiss. & Hausskn.

Abstract: The essential oil content in the aerial parts of the endemic species Pycnocycla caespitosa growing wild in the south of Iran was found to be 0.25 % based on the fresh weight. The oil was analyzed by GC and GC-MS. Fifty one constituents, representing 97.4 % of the oil were identified. The major components of the oil were β-eudesmol (20.3 %), 2,3,6-trimethyl benzaldehyde (13.2 %), Z-β-ocimene (6.1 %), α-pinene (5.9 %), spathulenol (4.6 %) and ρ-cymene (4.3 %).

An Efficient Acoustic Scattering Model Based on Target Surface Statistical Descriptors for Synthetic Aperture Sonar Systems

Abstract: Acoustic scattering as the perturbation of an incident acoustic field from an arbitrary object is a critical part of the target-recognition process in synthetic aperture sonar (SAS) systems. The complexity of scattering models strongly depends on the size and structure of the scattered surface. In accurate scattering models including numerical models, the computational cost significantly increases with the object complexity. In this paper, an efficient model is proposed to calculate the acoustic scattering from underwater objects with less computational cost and time compared with numerical models, especially in 3D space. The proposed model, called texture element method (TEM), uses statistical and structural information of the target surface texture by employing non-uniform elements described with local binary pattern (LBP) descriptors by solving the Helmholtz integral equation. The proposed model is compared with two other well-known models, one numerical and other analytical, and the results show excellent agreement between them while the proposed model requires fewer elements. This demonstrates the ability of the proposed model to work with arbitrary targets in different SAS systems with better computational time and cost, enabling the proposed model to be applied in real environment.