Iranian Journal of science and Technology (A: Siences)
Volume:39 Issue: 3, Summer 2015

The complex-step derivative approximation is applied to compute numerical derivatives. In this study, we propose a new formula of fractional complex-step method utilizing Jumarie definition. Based on this method, we illustrated an approximate analytic solution for the fractional Cauchy-Euler equations. Application in image denoising is imposed by introducing a new fractional mask depending on such a solution.

The effects of conduction band nonparabolicity, aluminum concentration and external electric field on the charge density and binding energy of an on-center hydrogenic donor impurity in a spherical quantum dot which is located at the center of a cylindrical nano-wire are studied. The energy eigenvalues and the corresponding wave functions are calculated using finite difference approximation within the effective mass framework. The results reveal that the binding energies (I) decrease as the electric field increases, (II) become negligible for large values of electric field, (III) increase as the aluminum concentration increases and (IV) the conduction band nonparabolicity has a noticeable effect on the binding energy, and hence should be taken into account.

In this paper the synthesis of some new polyaromatic monocyclic β-lactams has been reported. These cycloadducts have been synthesized by the [2+2] ketene-imine cycloaddition reaction known as the Staudinger reaction. All of the products have been fully characterized by IR, 1H-NMR, 13C-NMR, mass spectroscopy and elemental analyses. The X-ray crystal structure of a cis β-lactam has been also presented. The cycloaddition reaction was found to be totally diastereoselective leading exclusively to the formation of the cis-β-lactams for 3c-e, 3g, 3i-k, 3p and the rest were found to be totally trans.

Human mitochondrial DNA (mtDNA) is 16,569 base pairs (bp) in length, coding for 37 genes. During the course of evolution, nearly all the genes expressing ribosomal proteins and ribosomal RNAs (rRNA) genes have been transferred from the mitochondria to the nucleus. However, mitochondrial DNA contains two ribosomal RNAs genes (12S and 16S), which have not yet transferred to the nucleus. These two, should, soon or later, end up in the nucleus. What does the future likely hold for these genes? In the nucleus everything has already been prepared, since all of the ribosomal protein genes are now chromosomally encoded, and nucleolar organizers, the nucleolus, and 45 rDNA are developed waiting for 12S rRNA and 16S rRNA genes to join them, thus enabling the formation of the third DNA-containing organelle, the ribosomal compartment. What could be the reason for this major event in the existence of life on Earth as it is currently understood? The advent of the ribosomal organelle will likely have an enormous impact on reproductive characteristics and on intellectual (thoughts, abstract and complex ideas, imagination, dreams, spirit) activity of the brain. Could this be the answer to the question: Are humans still evolving?

Early Triassic carbonate ramp sediments of the lower part of the Elika Formation are known as Vermicular limestone. In the Moro Mountain, northwest Iran, the Vermicular limestone includes bioturbated dolomitic mudstone, bioclastic packstone and grainstone, algal calcirudite and intraclastic grainstone. These sediments accumulated in their lower part in open marine subtidal and shoal environments, changing upward to lagoonal and intertidal environments. Heavily bioturbated gray mudstone formed under quiet water conditions in lagoon and lower intertidal environments. Storm processes and high salinity indicative of an arid environment influenced the activities and distribution of euryhaline and/or opportunistic trace-makers. The low biodiversity of the trace-maker community is reflected by the low ichno-diversity, the sole trace fossil being abundant Planolites.

In this paper, the quintic B-spline collocation scheme is employed to approximate numerical solution of the KdV-like Rosenau equation. This scheme is based on the Crank-Nicolson formulation for time integration and quintic B-spline functions for space integration. The unconditional stability of the present method is proved using Von- Neumann approach. Since we do not know the exact solution of the nonlinear KdV-like Rosenau equation, a comparison between the numerical solutions on a coarse mesh and those on a refine mesh is made to show the efficiency of discussed method.

This paper aims to study a generalized double sinh-Gordon equation, which appears in several physical phenomena such as integrable quantum field theory, kink dynamics and fluid dynamics. Lie symmetry analysis together with the simplest equation method is used to obtain exact solutions for this equation. Moreover, we derive conservation laws for the equation by using two different approaches, namely, the direct method and the new conservation theorem due to Ibragimov.

The fabrication of a non-doped red organic light-emitting device (OLED) has been developed using naturally occurring curcumin as an emissive layer of OLED. In this research, the electroluminescent spectrum (EL) of curcumin as a donor-acceptor-donor (D-A-D) chromophore was obtained at wavelength of 612 nm. Also, the maximum external quantum efficiencies (EQE) for this device was measured and found to be 0.029 %. The device was characterized by low driving voltage below 1 V at a current density of 7 mA/cm2. High color purity with Commission International de l’Eclairage coordinates was measured and found to be (0.544, 0.441). Quantum mechanical calculations were achieved base on DFT/B3LYP/6-311G (d,p) level of theory to rationalize the optical properties, indicating the optimized energy and computing the HOMO-LUMO values. Good conformity was observed between theoretical and experimental data.

The current status and distribution of the dragonflies (Anisoptera) of Pakistan were studied during 2005-2009. Two dragonfly species were identified for the first time from Pakistan. Among these, Rhodothemis rufa is a red, medium-sized dragonfly. Lamelligomphus biforceps is also reported for the first time from Pakistan and re-described owing to having minor taxonomic differences from that of Fraser’s description. Some notes on the color, literature records and geographical distributions are summarized.

Inhibitory Effect of three benzothiazole derivatives (1, 3-benzothiazol-2-amine (BTA), 6-methyl-1, 3-benzothiazol-2-amine (MBTA) and 2-amino-1, 3-benzothiazole-6-thiol (TBTA)) on corrosion of carbon steel has been studied using density functional theory (DFT) method in gas and aqueous phases. Quantum chemical parameters such as EHOMO (highest occupied molecular orbital energy), ELUMO (lowest unoccupied molecular orbital energy), hardness (η), polarizability (α), surface area and total negative charges on atoms (TNC) have been calculated at the B3LYP level of theory with 6-311++G** basis set. The Mulliken charges of the molecules were also computed and Atoms-in-Molecule (AIM) method suggested the Fe-inhibitor interactions in these compounds are partially covalent and partially electrostatic. In good agreement with the experimental data, theoretical results showed the order of inhibitory efficiency is TBTA > MBTA > BTA.

We study the eigenenergies and eigenfunctions of the ground and first excited states (GFES) of an electron strongly coupled to the LO-phonon in an asymmetry quantum dot (AQD) under an applied electric field by using a variational method of the Pekar type (VMPT). This AQD two-level system may be viewed as a single qubit. When the electron is in the superposition state (SS) of the GFES, the effects of the electric field and temperature on the oscillating period (OP), the time evolution of the electron’s probability density (PD) and the coherence time (CT) are obtained. Our numerical results show that the electron’s PD and its OP will increase (decrease) with increasing temperature in low (high) temperature regime. The electron’s PD will decrease (increase) with increasing electron-phonon (EP) coupling strength in low (high) temperature regime. The OP is an increasing function of the electric field and will decrease obviously (increase tardily) with increasing EP coupling strength when the temperature is in lower (higher) rgime. The CT is an increasing function of the electric field, but a decreasing function of the coupling strength.

An endochitinase gene (chit36) was isolated from the biocontrol fungus Trichoderma atroviride. Chit36 was overexpressed under the CaMV35S constitutive promoter in canola. Transformation of cotyledonary petioles was achieved via Agrobacterium tumefaciens. The insertion of transgene was verified by PCR and DNA dot blotting. RT-PCR analysis indicated that the transgenic canola was able to express chit36 gene. Also, we used a transgenic over-expression approach in order to investigate antifungal activity of expressed chit36 on Sclerotiana sclerotiorum. Antifungal activity was detected in crude protein extracts from transgenic canola using radial diffusion assay. Also, lesion sizes of transgenic canola by S. sclerotiorum were significantly retarded compared to non transgenic canola plant using detached leaf assay.

Because of the everyday use of power generators in Iraq, which exist in residential neighborhoods, it is necessary to study the impact on soils and plants surrounding areas of those generators. Lead is one the most heavy metals released especially, as a result of the combustion of diesel fuel during operation of the powered generators. However, a study was conducted to investigate the lead concentration in soils and Bitter orange leaves affected by powered generators. Forty-eight soil s and sixteen plant samples were collected nearby and around the powered generators. It was found that soil and plant samples that fall under the influence of more than one generator exhibit higher concentration of lead than the soil and plant samples collected from the sites affected by one generator only, also the geographical location of the area in terms of the proximity of other pollutants, such as roads and factories in addition to the movement of wind are all factors that affect the concentration of lead in the soil and thus in the plant located there.

The energy loss of a 3-dimensional harmonic oscillator due to the quadrupole radiation in quadratic f (R) gravity is calculated.