Biodeterioration of cellulose materials in Karingote, Nileswaram, Kavvayi and Ramapuram Backwater systems of Kerala

The hydrographic conditions prevailing in an estuarine system along the southwest coast of India are described. The nature of destruction of timber in these backwaters has been examined in detail which revealed the existence of 8 species of shipworms, 2 species each of pholads and isopods. The shipworms are represented by Dicyathifer manni, Lyrodus pedicellatus, Teredo furcifera, T. clappi, Nausitora dunlopei, Bankia carinata, B. campanellata; the pholads by Martesia striata and M. (Purticoma) nairi; and the isopods by Sphaeroma terebrans and S. annandalei. The incidence and relative abundance of these pests are discussed in relation to the salinity profile of the estuary.

A comparative study on effects of Immunoster and Immunowall as immunostimulants on some hematological, biochemical and growth indices of farmed great sturgeon juveniles (Huso huso)

Prebiotics are non-digestible food ingredients that profitably affect the host by selectively stimulating the growth and /or activation of one or a limited number of bacteria in the intestine that can enhance host health status. Immunoster (IS) and Immunowall (IW) are prebiotics and immunostimulants derived from the outer cell wall of brewers yeast, Saccharomyces cerevisiae. These substances contain MOS and �-glucans. After a four-week acclimatization period to rearing conditions and basal diet, 450 farmed great sturgeon juveniles weighing 95.58 ± 9.38 g were randomly distributed into 15 fiberglass tanks (2 × 2 × 0.53 m) in five treatments (Control, IS 1%, IW 1%, IS 3%, and IW 3%) in three replicates (completely randomized design) and kept at a density of 30 fish per tank for a period of 8 weeks at water temperature 20.55 ± 5.11ºC, dissolved oxygen 6.73 ± 0.35 mg L-1 and pH 7.92 ± 0.09. IS and IW were added at two levels of 1% and 3% to the basal diet in place of cellulose, except the control. At the beginning, in the middle and at the end of the trial, carcass analysis was done to determine the moisture, protein, fat, ash, and total carbohydrate. Also, blood samples were collected to measure hematological, biochemical and immune indices. At the end of the trial, final weight, final length, body weight increase (BWI), specific growth rate (SGR), average daily growth (ADG), protein efficiency ratio (PER), feed conversion ratio (FCR), and condition factor (CF) in fish fed on IS and IW in both levels 1% and 3% showed some differences. These differences were significant in IS 3% and IW 1% and 3% compared with the control (P<0.05). HSI showed no significant difference (P>0.05) and survival rate was 100% in all treatments. Crude protein of carcass in fish fed on IS and IW at 1% and 3% showed an increase in comparison with the control. There was significant difference between IS 3% and the control in crude protein of carcass (P<0.05). Fish fed on IS and IW at 1% and 3% showed various results in hematological and biochemical factors. It was observed significant difference in MCV between IW 1% and IS 3% compared with the control (P<0.05). Although there was an increase in values of hematocrit, hemoglobin (except IS 1%), WBC (except IW 3%), MCH, neutrophil, total protein, albumin (except IS 3%), K+, and lysozyme in fish fed on IS and IW compared with the control, it was no significant (P>0.05). The maximum count of WBC and the highest value of Ca2+ were seen in IW 1%. The maximum count of lymphocyte, the highest values of total protein, albumin and IgM were recorded in IW 3%. IS 1% had the maximum count of neutrophil and the highest concentration of lysozyme. Based on obtained results, it can be declared that IS and IW at two levels of 1% and 3% can enhance growth performance and feed efficiency and also improve some hematological, biochemical, and immune indices in farmed great sturgeon juveniles.

Study of salinity gradients in the Persian Gulf and an experimental model for electric energy extraction from them using nano-membranes

Salinity gradient power (SGP) is the energy that can be obtained from the mixing entropy of two solutions with a different salt concentration. River estuary, as a place for mixing salt water and fresh water, has a huge potential of this renewable energy. In this study, this potential in the estuaries of rivers leading to the Persian Gulf and the factors affecting it are analysis and assessment. Since most of the full water rivers are in the Asia, this continent with the potential power of 338GW is a second major source of energy from the salinity gradient power in the world (Wetsus institute, 2009). Persian Gulf, with the proper salinity gradient in its river estuaries, has Particular importance for extraction of this energy. Considering the total river flow into the Persian Gulf, which is approximately equal to 3486 m3/s, the amount of theoretical extractable power from salinity gradient in this region is 5.2GW. Iran, with its numerous rivers along the coast of the Persian Gulf, has a great share of this energy source. For example, with study calculations done on data from three hydrometery stations located on the Arvand River, Khorramshahr Station with releasing 1.91M/ energy which is obtained by combining 1.26m3 river water with 0.74 m3 sea water, is devoted to itself extracting the maximum amount of extractable energy. Considering the average of annual discharge of Arvand River in Khorramshahr hydrometery station, the amount of theoretical extractable power is 955 MW. Another part of parameters that are studied in this research, are the intrusion length of salt water and its flushing time in the estuary that have a significant influence on the salinity gradient power. According to the calculation done in conditions HWS and the average discharge of rivers, the maximum of salinity intrusion length in to the estuary of the river by 41km is related to Arvand River and the lowest with 8km is for Helle River. Also the highest rate of salt water flushing time in the estuary with 9.8 days is related to the Arvand River and the lowest with 3.3 days is for Helle River. Influence of these two parameters on reduces the amount of extractable energy from salinity gradient power as well as can be seen in the estuaries of the rivers studied. For example, at the estuary of the Arvand River in the interval 8.9 days, salinity gradient power decreases 9.2%. But another part of this research focuses on the design of a suitable system for extracting electrical energy from the salinity gradient. So far, five methods have been proposed to convert this energy to electricity that among them, reverse electro-dialysis (RED) method and pressure-retarded osmosis (PRO) method have special importance in practical terms. In theory both techniques generate the same amount of energy from given volumes of sea and river water with specified salinity; in practice the RED technique seems to be more attractive for power generation using sea water and river water. Because it is less necessity of salinity gradient to PRO method. In addition to this, in RED method, it does not need to use turbine to change energy and the electricity generation is started when two solutions are mixed. In this research, the power density and the efficiency of generated energy was assessment by designing a physical method. The physical designed model is an unicellular reverse electro-dialysis battery with nano heterogenic membrane has 20cmx20cm dimension, which produced power density 0.58 W/m2 by using river water (1 g NaCl/lit) and sea water (30 g NaCl/lit) in laboratorial condition. This value was obtained because of nano method used on the membrane of this system and suitable design of the cell which led to increase the yield of the system efficiency 11% more than non nano ones.