The species composition and nutrition of dominant species of fish of Absheron Gulfs of the Caspian Sea

The analysis of net catches made in Absheron Gulfs of the Caspian Sea during 2011-2012 is provided. The ichthyofauna of Absheron Gulfs, including 26 species found in the North Gulf, and 33 species and subspecies found in the South Gulf was studied for the first time. A taxonomical and ecological diversity of the fish fauna of North and South Absheron Gulfs is characterized. The peculiarities of distribution and population densities of all species of fishes from different families within the studied territories were analyzed. For each of hydrological seasons, numerous, common, infrequent and rare species were revealed. On migration patterns and catch, the lowest biomass of fishes was observed in the warm season, while the highest was in the winter and spring seasons. The tendency of expansion of ranges of some marine fishes - Gasankuli herring Alosa braschnikowi kisselewitschi, Sara herring A. braschnikowi sarensis, big-eyed herring A. braschnikowi autumnalis, Sara shad A.caspia knipowitschi - to the north was recorded

Effect of the heave plate\u27s diameter on the transitional motions of a straked marine circular cylinder under different marine conditions

This numerical study investigated the influence of the heave plate\u27s diameter on the amplitude of the transitional motions of a marine circular cylinder (MCC) with a low aspect ratio under the marine current and regular waves. Due to the experimental model of the straked MCC, different diameters of the circular heave plate were chosen to be installed at the keel of the 3-straked MCC. In this numerical study, the diameter of the heave plate varied from 1.2 to 1.6 DMCC, while other parameters, such as reduced velocity (VR), Reynolds (Re) number, and Froude number, were kept constant. In this study, the transitional motions, including surge, sway, and heave, were analyzed. The results showed that increasing the heave plate\u27s diameter decreased the amplitude of the transitional motions in both marine current and regular waves. Also, the finding revealed that the heave plate not only reduced the amplitude of the heave motion but also decreased the amplitude of surge and sway motions. Moreover, the outcomes indicated that the heave plate\u27s diameter increased by approximately 20%–40% more than the MCC\u27s diameter. This caused the smaller amplitude of the transitional motions under both marine currents and regular waves

Wave Generated by the NACA4412 Hydrofoil near Free Surface

The generation of wave due to moving hydrofoil in steady streams close to a free surface is presented. The potential-based boundary element method is employed to the NACA4412 hydrofoil with linearized dynamic and kinematic boundary conditions on the free surface. The perturbation velocity potential is calculated using the Green formulation and Kutta condition. The numerical results of waves generated by the hydrofoil are presented and discussed at various Froude numbers and immersion depths

Identification of chemical compounds of <em>Nardostachys Jatamansi </em>essence available in Iran

Introduction: With regard to using drugs with plant origin and with the aim of suitable use of these types of drugs and preventing them to be abused, it is necessary to determine the standards of these plants. The aim of the present study was to identify and study chemical compounds of Nardostachys Jatamansi essence in Iran and define monograph of this plant for the Iranian plant pharmacopeia. Methods: In an experimental study the Nardostachys Jatamansi specimen was prepared from the market in Iran. The essence of the plant was prepared by the hydro-distillation in Clevenger apparatus. Essence was obtained as a greenish yellow oil layer with the 0.07 yield. The essence compounds were identified quantitatively by Gas Chromatography-Mass Spectroscopy (GC/MS) method. Results: Totally, 29 compounds were identified in Nardostachys Jatamansi essence. The retention indexes (RI) were only similar with overall standard values in two compounds like mesitylene and P-cymene. In this line the RI values about three compounds of valerenic acid, palmitic acid, and valerenyl isovalerate were determined significantly higher than standard values of RI. Conclusion: The essence prepared from the Nardostachys Jatamansi plant in Iran was different in terms of some compounds and components including valerenic acid, palmitic acid, and valerenyl isovalerate and so it is necessary to identify and register quality and quantity characteristics of compounds available in this plat in the Iranian medicinal plants pharmacopeia.</p

Petrology, geochemistry and tectonomagmatic evolution of Hezar Igneous Complex (Rayen - south of Kerman - Iran): the first description of an arc remnant of the Neotethyan subduction zone

The Hezar Igneous Complex (HIC) in the south-eastern part of Urumieh-Dokhtar magmatic arc, is the most prominent magmatic feature in the Kerman Porphyry Copper Belt, that understanding magmatic evolution of which may shed light on the tectonomagmatic development of this less-studied part of an important magmatic arc in the Neotethys realm. The HIC has been developed in the the intersection of the N-S striking Sabzevaran fault and the NW-SE striking Rafsanjan-Rayen fault. It is indicated that the possible place of the conduit and vent is in Jalas Mountain which has been splitted later by the Sabzevaran fault into Minor and Major Jalas. The current summit had been constructed by ascending magma chamber under the HIC that constitutes the Kamali Mountain at the south of the summit. Some plutonic rocks of the HIC are exposed at Kamali Mountain. The subalkaline rocks of this complex mainly are composed of different pyroclastic and lava flow rocks, acidic to basic in composition, showing the evidences of fractional crystallization and mineral segregation. Sequential explosive and effusive eruptions with Strombolian to Vulcanian types are evident in the successive volcanic layers. The compositional trend shows the melting of spinel lherzolite, not garnet lherzolite. The subduction-related mechanism of the magma genesis has been indicated by IAB nature of the magma formation in geochemical diagrams.publishe

On the Instability of Two Dimensional Backward-Facing Step Flow using Energy Gradient Method

In the present paper, the energy gradient method is implemented to study the instability of 2-D laminar backward-facing step (BFS) flow under different Reynolds numbers and expansion ratios. For this purpose, six different Reynolds numbers (50 ≤ Re ≤ 1000) and two various expansion ratios of 1.9423 and 3 are considered. We compared our results of the present study with existing experimental and numerical data and good agreement is achieved. To study of fluid flow instability, we evaluated the distributions of velocity, vorticity and energy gradient function K. The results of our study show that as the expansion ratio decreases the flow becomes more stable. We also found that the origin of instability in the entire flow field is located on the separated shear layer nearby the step edge. In addition, we approved that the inflection point on the profile of velocity corresponds to the maximum of vorticity resulted to the instability

Two Semi-Analytical Methods Applied to Hydrodynamic Stability of Dean Flow

Hydrodynamic stability of Dean flow is studied using two semi-analytical methods of differential transform method (DTM) and Homotopy perturbation method (HPM). These two methods are evaluated to examine the effectiveness and accuracy of the solution of considered eigenvalue problem. Very good accordance is achieved between our semi-analytical results compared to existing numerical data. Based on our analysis, in the similar number of truncated terms, HPM is more accurate in comparison with DTM. We also concluded that for the higher wave numbers, HPM provide more accurate results with less truncated terms compared to the DTM. Finally, we found the critical Dean number 35.927 corresponding to wave number of 3.952 for onset of instability of Dean flow