Iranian Journal of science and Technology (A: Siences)
Volume:39 Issue: 2, Spring 2015

This study was conducted to determine taxonomic feature of fishes from the headwaters of three riverine systems in Kohgiluyeh and Boyer-Ahmad province (K & B) in southwestern Iran during 2011 to 2013. Fifteen species belonging to 4 families, and 3 orders from the Karun river system, 10 species belonging to 4 families and 3 orders from the Zohreh river system and 8 species belonging to 2 families and 2 orders from the Jarrahi river system were identified. In total 19 species were collected, including 14 natives, 4 endemics and 1 exotic.

The Normalized Difference Vegetation Index (NDVI) derived from the SPOT 4 satellite has been widely used to monitor moisture-related vegetation condition. The relationship between vegetation and climate index, however, is complex and has not been adequately studied with satellite sensor data. To better understand this relationship, an analysis was conducted on time series of monthly NDVI (1999–2009) during the growing season in the Semnan province. The NDVI was correlated to the Standardized Precipitation Index (SPI), a multiple-time scale meteorological-drought index based on precipitation. The 3 and 24 month SPI were found to have the best correlation with NDVI, indicating lag and cumulative effects of precipitation on vegetation, but the correlation between NDVI and SPI varies significantly between months. Results show that combining NDVI and a climatic index is a suitable method for estimating land cover changes. Steppe range land or class 7 in all stations had a higher correlation between NDVI and SPI. Land covers with vegetation have significant correlations in spring and summer months. The highest correlations occurred during the middle of the growing season, and lower correlations were noted at the beginning and end of the growing season in most of the area. A stepwise regression model showed that the relationship between the NDVI and SPI was significant in both rangelands and forest.

An efficient synthesis of 1, 8-dioxo-octahydroxanthens and 1, 8-dioxo-decahydroacridines from the reaction of 5,5-dimethyl-1,3-cyclohexanedione (dimedone) with aromatic aldehydes bearing electron-donating or withdrawing substituents either in the presence or absence of primary amines has been described in a single pot using a catalytic amounts of aluminum tris (dodecyl sulfate) trihydrate [Al(DS)3·3H2O] as a Lewis acid-surfactant-combined catalyst. Both reactions occurred at 80 oC. 1, 8-dioxo-octahydroxanthens has been synthesized under solvent-free conditions and water is used as a green solvent for the synthesis of 1, 8-dioxo-decahydroacridines. This methodology offers several advantages such as very simple work-up procedure, short reaction times, and mild reaction conditions.

Despite two decades of artificial spawning of wild carp (Cyprinus carpio) to rehabilitate natural populations in the southeastern Caspian Sea, there are still no appropriate physiological criteria for selecting competent brooders during induced spawning. To this end, the plasma concentrations of vitellogenin (Vtg), phosphorus (P) and calcium (Ca) were measured during ovarian development, as potential criteria for selecting ripe brooders. Vtg was measured by ELISA using pure carp Vtg and its specific antibody. P and Ca contents of plasma samples were also determined photometrically and colorimetrically, respectively, by Autoanalyzer using commercial specific kits. The plasma levels of Vtg showed no significant differences during sampling times, whereas its highest significant value (922±301 μg/ml) was recorded in late vitellogenesis (P≤0.05). The plasma concentrations of Ca also showed no significant differences in different stages of ovarian development except for late vitellogenesis (16.65±1.77mg/dl) and during sampling times except for June (17.24±1.76mg/dl) that rose to its peak. The plasma levels of P increased gradually during sampling times and reached maximum value in June (35.22±11.12mg/dl). Level of P also increased gradually during ovarian growth and peaked at late vitellogenesis (33.94±8.02mg/dl) and slowly decreased afterward. The regression analysis indicated that plasma P levels showed a high correlation with plasma Vtg concentrations. Therefore due to easier and lower cost of plasma P measurement in fish in comparison with Vtg, measurement of plasma P levels is recommended as criterion for selecting ripe females for artificial spawning.

Freeze-thaw is one of the most powerful weathering agents that may cause a rapid change in the initial engineering properties of stones, and limit their durability. Freeze-thaw induces stress over the pores’ surface of stones. Consequently, stone durability is closely related to its engineering and physical properties. The purpose of this study is estimating the engineering properties of deteriorated stones after freeze-thaw using multiple regression analysis. For this purpose, laboratory tests were conducted on 14 different building stones, and their petrographical characteristics, and engineering and physical properties were determined as well. Then freeze-thaw action was simulated for 30 cycles, and the engineering properties of stones including Brazilian tensile strength, point load index and P-wave velocity were determined. The statistical models for estimating the engineering properties after freeze-thaw were developed by multiple regression analysis. The models were validated by statistical tests, and the results showed that engineering properties of stones can be estimated after freeze-thaw using their initial engineering and physical properties with good accuracy.

The Kasian volcanic body is located in the eastern margin of the Zagros thrust belt, close to the Sanandaj-Sirjan metamorphic zone. These volcanic rocks are mainly composed of andesite and andesite-basalt rocks with porphyritic, hypocrystalline porphyritic, hyalo-porphyritic and hyalo-microlitic porphyritic textures. Analyses of the distributions of major, rare earth and trace elements reveal a tholeiitic nature and evidence such as enrichment of Pb and LILE (e.g., U, Rb, Ba), depletion in HFSE (e.g., Nb, Ti, Y), slight enrichment of LREE relative to HREE and trace elements discrimination plots reveal island arc affinity for the Kasian volcanic rocks. Some characteristics like, low Nd/Pb and Ce/Pb values (average 8.76 and 12.70, respectively), high U values and low Nb/U ratios (average 3.52) indicate enrichment of mantle wedge by contribution of slab-derived fluids during dehydration of subducting slab of Neo-Tethys oceanic lithosphere. Moreover, the results show these volcanic rocks to have fractionated as they ascended to higher crustal levels. The results of this study are consistent with the new tectonic scenario for the Sanandaj-Sirjan zone, which suggests that during ocean–ocean subduction (from Jurassic to Cretaceous) an immature island arc developed before the closure of Neo-Tethys ocean.

An efficient and chemoselective procedure for the preparation of 1, 1-diacatates (acylals) from various aldehydes with acetic anhydride in the presence of Brønsted acidic ionic liquid [Msei]Cl as a reusable catalytic system under solvent-free condition at room temperature and short periods of times with excellent yields will be described. The catalyst was easily separated in simple work-up and was recycled several times without loss of reactivity under the described reaction conditions.

Two newly-created water-soluble complexes of palladium (II) /platinum (II) -dithiocarbamate، [Pd/Pt (phen) (pyr-dtc)]NO3 (phen = 1،10-phenanthroline and pyr-dtc = pyrrolidinedithiocarbamate) were synthesized. Also، their chemical characteristics are reported in the current research paper. In these complexes، the dithiocarbamato ligand coordinates to Pt (II) or Pd (II) center with two sulfur atoms as bidentate. They were examined for their cytotoxic properties against chronic myelocytic leukemia K562 cell lines. These complexes showed 50% cytotoxic concentration (Cc50) values much lower than those of cisplatin. The interactions of the two complexes with calf thymus DNA (CT-DNA) were investigated using UV-vis absorption، fluorescence emission، ethidium bromide displacement and gel filtration techniques. The results suggest that these complexes cooperatively bind with and denature the DNA at low concentrations and interact with CT-DNA in the intercalation mode. Gel filtration studies indicate that the binding of complexes with DNA is strong enough not to break readily.

The ground state properties of liquid 𝐻𝑒3 in the presence of magnetic field have been investigated. In our calculations, we have employed a variational many-body formalism using the Lennard-Jones and Aziz inter-atomic potentials. For this system, we have also computed the magnetization in magnetic fields up to 200 T. Our results show no ferromagnetic phase transition induced by the magnetic field. Here, a comparison has also been made between the results of the Lennard-Jones and Aziz potentials.

An improved mixed order model is presented to describe the thermolumunescence (TL) glow peaks. In this model a fraction of charge carriers, which undergo nonradiative recombination following thermal excitation is taken into account. Therefore, it is expected that the proposed model will produce more realistic kinetic parameters than that of mixed order model. The TL glow curves generated by the proposed model are fitted to the glow curves of general order and mixed order models using a curve fitting program. The results are presented and discussed.

Let 𝑀 be a lattice module over the multiplicative lattice 𝐿. 𝑀 is said to be a comultiplication 𝐿-module if for every element 𝑁 of 𝑀 there exists an element 𝑎∈𝐿such that 𝑁(0𝑀:𝑀𝑎. Our objective is to investigate properties of comultiplication lattice modules.

The present study is an attempt to investigate some features of Radial Basis Functions (RBFs) approximation methods related to variational problems. Thereby authors applied some properties of RBFs to develop a direct method which reduces constrained variational problem to a static optimization problem. To assess the applicability and effectiveness of the method, some examples are examined. Dynamic investment problem with free endpoint in unbounded domain is solved, accordingly the effectiveness of the proposed method is verified. To improve the accuracy and stability of the method we have used various shape parameter strategies with equally spaced and scattered centers. Finally, two new shape parameter strategies are proposed and then it is shown that the proposed strategies increase the accuracy and stability of the method.

A projective parameter of a geodesic as solution of certain ODE is defined to be a parameter which is invariant under projective change of metric. Using projective parameter and Poincaré metric, an intrinsic projectively invariant pseudo-distance can be constructed. In the present work, solutions of the above ODE are characterized with respect to the sign of parallel Ricci tensor on a Finsler space. Moreover, the Ricci tensor is used to define a Finsler structure and it is shown that, the pseudo-distance is trivial on complete Finsler spaces of positive semi-definite Ricci tensor and it is a distance on a Finsler space of parallel negative definite Ricci tensor.

Simple harmonizable processes (SHP) introduced by Soltani and Parvardeh (2006) are a large class of nonstationary processes which includes stationary and periodically correlated (PC) processes. Detection and estimation of SHP structure are important problems when dealing with nonstationary data. In this paper, we study the spectral properties of simple processes and propose a method to detect and estimate SHP structure. As an example, we discuss the detection, estimation and prediction of periodically correlated processes. The performance of this method is investigated through extensive Monte Carlo simulations. This method is compatible with other method.