Determination of the growth rates of Spirolina and Cheatoceros algae in urban waste sewage and their capability to deplete nitrate and phosphate content in the sewage

The application of cyanobacterial and diatom cultures for the treatment of industrial effluents has been well recognized.In this study aimed to evaluate the effect of urban sewage on growth of Spirolina plantensis and Chaetoceros muelleri. The experiment was conducted in 6 treatments as a growth medium. Result showed that in treatment 5 maximum cell densities was (565×102±237.7) at day7 thus treatment 5 has best condition for growth S. plantensis and in treatment 3 maximum cell density was (825×104±92) at day13.Treatment 5 has best condition for growth C. muelleri. Total chlorophyll a, contents (μg/1) recorded in S. Plantensi sand C. muelleri was highest at treatment 3(0.21±0.07) and treatment 4(0.23± 0.10) respectively. In present investigation, both the algal species can be good potential to growth in urban sewage. The urban sewage removal efficiency of C. muelleri was higher as compare to S.plantensis which can be recommended for phytoremediation purpose.Keywords: Spirolina; Chaetoceros;Nitrate and phosphate; Chlorophyll a;Urban sewage; Depletio

Estimation of population dynamics parameters of Scomberomorus commerson using modal progression method in the Hormouzgan province waters

Scombermorus commerson is one of the most important commercial fish species in the Persian Gulf and Sea of Oman. To arrange for a sustainable fishing pattern, growth parameters, mortality and exploitation rates of the fish were estimated. Fish length data were collected from 4515 fishes, science April 2007 to March 2008 in three major artisanal fish-landing sites Bandar Lengeh, Bandar Abbas and Bandar Jask in Hormouzgan province waters. The Von Bertalanffy growth parameters (L∞ K and t _(0)) were estimated at 150.24 (cm), 0.66 year ^(-1) and -0.157 year, respectively. The results showed that S. commerson grows very fast in the first 2 years. The results indicated that S. commerson attains its fork length 80.3 cm at the end of first year. The fork length attained at the end of the second, third and fourth years were 114.1, 131.6 and 140.6 cm, respectively. Growth performance index (f) was calculated at 4.1 which were in agreement with the findings of the other studies in the Indian Ocean. Total, natural, fishing mortality and exploitation rate were estimated at 2.11, 0.67, 1.44 year ^(-1) and 0.64, respectively. Five cohorts were distinguished based on Bhattacharya's method

The Effect of Surface Roughness of Inconel 738 Superalloy on the Adhesive Properties of 8YSZ Coatings Deposited by Electrophoretic Deposition (EPD)

The electrophoretic deposition coating method has recently received attention as a new method for thermal barrier coating due to its advantages such as the simplicity of the method, controllability of the process, and the need for simple equipment. In this study 8 wt % yttria- stabilized zirconia was deposited on Inconel 738 substrate at room temperature by electrophoretic deposition. Before deposition, the substrates were treated by sand blasting treatment (by silica sands with different sizes) and roughness in the range of Ra=1 and Ra=3 was achieved on the substrate surfaces. The coated samples were sintered at 1100 °C temperature under controlled atmosphere (Ar atmosphere). X-Ray diffraction, scanning electron microscopy and thermal shock resistance technics were used to investigating of structural and phase properties and adhesiveness between coatings and substrates. Results from thermal shock resistance test show that by increasing roughness number, the thermal shock resistance ability first increased and then decreased. In addition, according to SEM images, increasing of roughness number, causes decrease the microcracks that creating in the coating surface. The best result was observed for coatings deposed on substrate with Ra=2

First record of the Thuridilla indopacifica Gosliner, 1995 (Sacoglossa, Plakobranchidae) from the Gulf of Oman, Iran

Thuridilla indopacifica Gosliner, 1995 (Sacoglossa, Plakobranchidae) is a rare species in the Sacoglossan nudibranch that only reported from the South Africa and Western Australia. This study records T. indopacifica from the Gulf of Oman for the first time showing its expansion to the northwest of Indian Ocean