Study of seasonal plankton communities changes in the Karoun dam reservoir and their relationship with water quality parameters

This study was under taken at Karoun Lake Dam No.4. (Southwest of Iran). Water samples were collected from March 2012 to February 2013 in three selected silts. Environmental parameters and chlorophyll a concentration were measured, as well as identification and abundance of Phytoplankton communities were studied. According to this study, 30 species of Phytoplankton were identified at four seasons. Most abundance was related to the phyla Bcillariphyta (17 species), Chlorophyta (6 species), Crysophyra (4 species), Dinophyta (2 species) and Cyanophyta (1 species) respectively. The results showed, the maximum rate of chlorophyll a concentration was measured in the warm with minimum level measured in the cold months. The rate of chlorophyll a concentration showed an oligotrophic condition in the lake of karoon 4 dam. positive significant correlation were seen between the parameters of COD,NO3,temperature, pH, turbidity, chlorophyll a and phytoplankton abundance (P<0.01). The chlorophyll a concentration and phytoplankton community had a significant negative correlation with transparency (-P < 0.01). According to this research, 4 phyla of zooplankton was identified, include Rotifera, Protozoa, Cladocera and Copepoda. Overal 43 species were identified at four seasons. Most abundance was related to the phyla Rotifera (27 species), Copepoda (7 species), Cladocera (5 species) and Protozoa (4 species) respectively. The chlorophyll a concentration, amount of phosphate and zooplankton indicator spesies, showed an oligotrophic condition in the lake of karoon 4 dam. A positive significant correlation was seen between all groups of zooplanktons abundance and temperature, as well as chlorophyll a concentration. (P<0.01) , whereas, there was negative correlation whith no significant between DO and zooplankton communities (P>0.05).

Identification of mesopelagic fish (with emphasis on major family) in Iranian water of the Oman Sea

This project was done for identifying the mesopelagic fish of the Iranian waters of Oman Sea, during two year from 2008 to 2010. The specimens were collected using two trawler vessel from nine station. All the specimens were fixed in formalin then in 70% alcohol and carried to the laboratory. In total of 19 species belonged to 14 families of 6 orders identified including: Echinorhinidae, Stomidae, Phosichthyidae, Synodontidae, Paralepididae, Myctophidae, Acropomatidae, Priacanthidae, Pentacerotidae, Champsodontidae, Gempylidae, Trichiuridae, Nomeidae and Congridae. Of which 17 species were identified up to species level including: Echinorhinus brucus, Bathophilus indicus, Chauliodus sloani, Harpadon nehereus, Lestrolepis japonica, Benthosema pterotum, Diaphus garmani, Diaphus effulgens, Bolinichthys photothorax, Acropoma japonicum, Synagrops adeni, Cookeolus boops, Histiopterus typus, Champsodon sagittus, Neoepinnula orientalis, Trichiurus lepturus, Cubiceps baxteri. Vinciguerria was identified up to genus level because only one specimen caught during the survey and one species (Congridae) was identified up to family level because only 3 specimens of this fish in early stage of life were caught and their characters were not suitable for identify up to species level. The highest species belong to Myctophidae family of Myctophiformes order.

The seasonal variations of sea level due to density variations in the Arabian Gulf and Gulf of Oman

From the distribution of oceanographic data (temperature and salinity) in both Arabian Gulf and Gulf of Oman, the steric components (thermal, haline and steric heights) are calculated for the upper 50m layer during different seasons. The analysis reveals relevant evidence, that temperature variations (thermal component) play a role in the fluctuations of sea level within the investigated area. The salinity variations (haline component) is only significant near the entrance. The sea level variations due to density (steric component) is low during winter and spring and high during summer and autumn. The steric height is always lower in the northern and central regions of Arabian Gulf and higher in eastern region of Arabian Gulf and in the Gulf of Oman, i.e. the surface water must flow from the Gulf of Oman to the Arabian Gulf. The steric sea level gradient around the Strait of Hormuz are 0.04 cm/km in winter, 0.04 cm/km in spring, and 0.025 cm/km in summer and 0.014 cm/km in autumn.

A water budget study of Lake Manzalah, Egypt

Based on the freshwater and seawater budgets, the mean in/out water fluxes as well as the monthly changes in freshwater content were determined in Lake Manzalah. About 6693 x 10^6m^3 of fresh and brackish water inflow to the lake annually through the main drains discharging into the southeastern basin. Allowances of precipitation (105.7 x 10^6m^3/y) and evaporation (1075 x 10^6m^3/y) yield a net runoff of 5723 x 10^6m^3/y. The average changes in the freshwater content (dF) of the lake was 547.0 x 10^6m^3 with the maximum i.e. 72.4 x 10^6m^3 in July. Using the quantity of inflowing and outflowing water through Boughaz El-Gamil (Lake-Sea connection), the change in water volume relative to sea level change was 549 x 10^6m^3/y. The sea-level height (dh) induced an average monthly change of 6.5 cm. Using the amount of freshwater discharge as well as the lake volume, the lake water is replaced every 48 days.

Water quality assessment of Sonbolrood River by using hylsenhof index

This research investigates the quality of sonbolrood river by using Hylsenhof HFBI indicators and identified Macroinvertebrates invertebrates community in the family level. This study took place during 1388-1389 with four sampling season in four stations respectively in the forests of Kalyj kheyl village in Savadkuh (first station), industrial area of Islamabad (second Station), earth dam of Sonbolrood (third station) and the Place crosses Sonbolrood with Babolrood river (fourth Station). Macroinvertebrates invertebrates collected by quantitative sampler of Sorbr and they were isolated in laboratory by loop and they were identified in the family level. Generally, Macroinvertebrates of Sonbolrood river were formed three branches: Arthropods and flat worms and mollusks, including 3 tiers, 6 orders and 14 families that showed the maximum diversity and density in autumn and the least diversity and density in summer at all stations, also the third and fourth stations respectively were highest and lowest diversity and density. The water quality of Sonbolrood river based on the water quality Guide(Hylsenhof) is evaluated with excellent condition for all stations except third station. Sonbolrood river with having high slope, rocky and sandy bed, with self-refining act, completely is a proper ecosystem for aquatic organisms, but it is done due to increased organic matter and sewage factory located in industrial zone in the third station and then the increased water pollution caused by nurturing the water warm fish in the earth dam of Sonbolrood. (because of this, the water quality at third station based on the water quality Guide(Hylsenhof) are evaluated in a fairly good condition) and adding domestic sewages of adjacent villages like Seyedkola village and Shirdarkola caused increased pollution and increased trophy of Macroinvertebrates that are resistant to pollution and affect upon Macroinvertebrates community.

The study of different protein in diet and water salinity on growth and survival rate in Pacific white shrimp (Litopenaeus vannamei)

In this research reared white western shrimp (Litopenaeus vannamei ,Boone, 1931) with five diet with five different protein level contain 20%, 25%, 30%, 35% and 40% and three salinity level contain 15-17 ppt, 27-30 ppt,and 40-45 ppt researched protein percent effect and water salinity on growth, survival, feed conversion ratio, hemolymph osmolatity, hemolymph protein and corpse protein contain. In this research was 15 sorrow with 3 repeat and used from 45 tanks with 300 liters capacity. Shrimps first weight average was about 2 grams and after 60 days culture cropped down results: Shrimps biomass growth in 15-17 ppt salinity was higher than anther salinities who had meaning different with growth in 40-45 ppt salinity ( p< 0.05). But hadn’t meaning different with growth 27-30 ppt salinity. survival rate in 15-17 ppt salinity was 97.03 who was lower than another salinities. survival percent in 24-30 ppt salinity and 40-45 ppt salinity was 99.33% Highest biomass growth in different diets was in diet number 5 with 40 percent protein that it had meaning different with another diets (p<0.05) . although with informed to product expense in different diets. One kilogram shrimp product expense in different diets hadn’t meaning different (P<0.05) Survival rate in different diets hadn’t meaning different lowest feed conversion ratio was 1.67 in 15-14 salinity that hadn’t meaning different with another salinities also corpse protein quantity in different salinities and different diets hadn’t meaning different. Hemolymph Osmolality in 15-17 ppt salinity was 573.88 mOsm/kg had meaning different with hemolymph osmolality in 27-30 ppt salinity that was 650. 380 mOsm/kg and in 40-45 ppt salinity was 630.38 mOsm/kg. Hemolymph protein in 15-17 ppt salinity was 124.72 mg/ml had meaning different with hemlymph protein in 27-30 ppt salinity that was 136.52 mg/ml but hadn’t meaning different with hemolymph protein in 40-45 ppt salinity that was 128.84 mg/ml. Hemolymph protein in different diets hadn’t meaning different (p<0.05). Keywords: shrimp, Litopenaeus vannamei, protein , salinity, growth, survival rate, FCR, hemolymph osmolality, hemolymph protein.

The residue measurment of pesticide in water and biota of the Sorkhrood River in the south of the Caspian Sea

Pesticide residue is considered as a crucial factor in the fresh water ecosystem pollution of north Iran (Esp. Gillan and Mazandaran provinces). It is also regarded dangerous to the health of human being and animals. In this research , pesticide residue in 3 species of fish was gauged in stations of the Haraz river , the Sorkhrood river , and the Caspian sea. The sampeles were taken during 27 mounths (started in April 97 and ended to June 99). The maximum level of pesticide in water was found in July 98 for lindine at 12.4 ppb. The level of chlorinated pesticide residue recorded at 63 ppb in April 98. The level of. organophosphorus pesticides residue in water was at 1.75 ppb in Aug 97. The toxicity of the mentioned pesticide and bioaccomulation were taken into account in conducting this researched.

Interactions of dietary levels of protein and energy on rainbow trout (Oncorhynchus mykiss) in desert brackish water

A 3x3 factorial experiment was conducted to determine the optimum protein to energy (P/E) ratio for rainbow trout in brackish water. Three crud protein levels and three energy levels at each protein level were utilized. Diets were made in semi-purified that in all of them fish meal, casein and gelatin as the sources of protein and dextrin, starch and oil as the sources of energy were used. Each of experimental diets was fed to triplicate groups of 20 fish with an average individual weight of 81.5 g in 9 2000-1 flow trough fiberglass tanks. During this experiment water temperature, dissolved oxygen, PH and EC were 15±2°C, 6.5-8.1 mg/1, 7.7-8.6 and 25400 grills respectively. The diets were fed at a rate between 1.6-2 wet body weight% per day depended to water temperature in three equal rations and adjusted two weekly for 84 days. At each of protein levels, weight gain percent (%WG), average daily growth percent (%ADG), protein efficiency ratio (PER), apparent net protein utilization percent (%ANPU), or percent of protein deposited, specific growth rate (SGR) and condition factor (CF) were found to increase and food conversion ratio (FCR) was found to decrease with an increasing energy levels from 370 to 430 Kcal/100g. Fish fed a 35% protein, 430 Kcal/100g energy diet with a P/E ratio of 81.4 mg protein/ Kcal PFV energy, attained the best growth performance. Fat and moisture of carcass were affected by protein and energy levels of test diets while protein and ash of carcass were relatively constant in different treatments.

QM/MM simulation of liquid water with an adaptive quantum region.

The simulation of complex chemical systems often requires a multi-level description, in which a region of special interest is treated using a computationally expensive quantum mechanical (QM) model while its environment is described by a faster, simpler molecular mechanical (MM) model. Furthermore, studying dynamic effects in solvated systems or bio-molecules requires a variable definition of the two regions, so that atoms or molecules can be dynamically re-assigned between the QM and MM descriptions during the course of the simulation. Such reassignments pose a problem for traditional QM/MM schemes by exacerbating the errors that stem from switching the model at the boundary. Here we show that stable, long adaptive simulations can be carried out using density functional theory with the BLYP exchange-correlation functional for the QM model and a flexible TIP3P force field for the MM model without requiring adjustments of either. Using a primary benchmark system of pure water, we investigate the convergence of the liquid structure with the size of the QM region, and demonstrate that by using a sufficiently large QM region (with radius 6 Å) it is possible to obtain radial and angular distributions that, in the QM region, match the results of fully quantum mechanical calculations with periodic boundary conditions, and, after a smooth transition, also agree with fully MM calculations in the MM region. The key ingredient is the accurate evaluation of forces in the QM subsystem which we achieve by including an extended buffer region in the QM calculations. We also show that our buffered-force QM/MM scheme is transferable by simulating the solvated Cl(-) ion.

Near-complete transuranic waste incineration in a thorium fuelled pressurised water reactor

The production of long-lived transuranic (TRU) waste is a major disadvantage of fission-based nuclear power. Incineration, and virtual elimination, of waste stockpiles is possible in a thorium (Th) fuelled critical or subcritical fast reactor. Fuel cycles producing a net decrease in TRUs are possible in conventional pressurised water reactors (PWRs). However, minor actinides (MAs) have a detrimental effect on reactivity and stability, ultimately limiting the quality and quantity of waste that can be incinerated. In this paper, we propose using a thorium-retained-actinides fuel cycle in PWRs, where the reactor is fuelled with a mixture of thorium and TRU waste, and after discharge all actinides are reprocessed and returned to the reactor. To investigate the feasibility and performance of this fuel cycle an assembly-level analysis for a one-batch reloading strategy was completed over 125 years of operation using WIMS 9. This one-batch analysis was performed for simplicity, but allowed an indicative assessment of the performance of a four-batch fuel management strategy. The build-up of 233U in the reactor allowed continued reactive and stable operation, until all significant actinide populations had reached pseudo-equilibrium in the reactor. It was therefore possible to achieve near-complete transuranic waste incineration, even for fuels with significant MA content. The average incineration rate was initially around 330 kg per GW th year and tended towards 250 kg per GW th year over several decades: a performance comparable to that achieved in a fast reactor. Using multiple batch fuel management, competitive or improved end-of-cycle burn-up appears achievable. The void coefficient (VC), moderator temperature coefficient (MTC) and Doppler coefficient remained negative. The quantity of soluble boron required for a fixed fuel cycle length was comparable to that for enriched uranium fuel, and acceptable amounts can be added without causing a positive VC or MTC. This analysis is limited by the consideration of a single fuel assembly, and it will be necessary to perform a full core coupled neutronic-thermal-hydraulic analysis to determine if the design in its current form is feasible. In particular, the potential for positive VCs if the core is highly or locally voided is a cause for concern. However, these results provide a compelling case for further work on concept feasibility and fuel management, which is in progress. © 2011 Elsevier Ltd. All rights reserved.

The potential of Nakivubo swamp (papyrus wetland) in maintaining water quality of inner Murchison bay - Lake Victoria

Nakivubo swamp (papyrus wetland) is located in the south east of the city of Kampala, Uganda. This swamp has been receiving waste water from Nakivubo channel for more than two decades. This investigation was aimed at monitoring the level of pollutants (nutrients and faecal coliforms) as the waste water filtrates through the swamp and the flow patterns of waste water through the swamp. From this preliminary investigation it was found out that the waste water is not evenly distributed over the swamp. Also high levels of pollutants seem to filtrate through the swamp and enter Inner Murchison Bay - Lake Victoria. Further research is under way to investigate in more detail the capacity of Nakivubo swamp to remove nutrients/pollutants from waste water flowing through it and the dominant mechanisms/processes involved.

Study of the turbulence in the air-side and water-side boundary layers in experimental laboratory wind induced surface waves

This study detailed the structure of turbulence in the air-side and water-side boundary layers in wind-induced surface waves. Inside the air boundary layer, the kurtosis is always greater than 3 (the value for normal distribution) for both horizontal and vertical velocity fluctuations. The skewness for the horizontal velocity is negative, but the skewness for the vertical velocity is always positive. On the water side, the kurtosis is always greater than 3, and the skewness is slightly negative for the horizontal velocity and slightly positive for the vertical velocity. The statistics of the angle between the instantaneous vertical fluctuation and the instantaneous horizontal velocity in the air is similar to those obtained over solid walls. Measurements in water show a large variance, and the peak is biased towards negative angles. In the quadrant analysis, the contribution of quadrants Q2 and Q4 is dominant on both the air side and the water side. The non-dimensional relative contributions and the concentration match fairly well near the interface. Sweeps in the air side (belonging to quadrant Q4) act directly on the interface and exert pressure fluctuations, which, in addition to the tangential stress and form drag, lead to the growth of the waves. The water drops detached from the crest and accelerated by the wind can play a major role in transferring momentum and in enhancing the turbulence level in the water side.On the air side, the Reynolds stress tensor's principal axes are not collinear with the strain rate tensor, and show an angle α σ≈=-20°to-25°. On the water side, the angle is α σ≈=-40°to-45°. The ratio between the maximum and the minimum principal stresses is σ a/σ b=3to4 on the air side, and σ a/σ b=1.5to3 on the water side. In this respect, the air-side flow behaves like a classical boundary layer on a solid wall, while the water-side flow resembles a wake. The frequency of bursting on the water side increases significantly along the flow, which can be attributed to micro-breaking effects - expected to be more frequent at larger fetches. © 2012 Elsevier B.V.

Water, salt water, and alkaline solution uptake in epoxy thin films

As a means of characterizing the diffusion parameters of fiber reinforced polymer (FRP) composites within a relatively short time frame, the potential use of short term tests on epoxy films to predict the long-term behavior is investigated. Reference is made to the literature to assess the effectiveness of Fickian and anomalous diffusion models to describe solution uptake in epoxies. The influence of differing exposure conditions on the diffusion in epoxies, in particular the effect of solution type and temperature, are explored. Experimental results, where the solution uptake in desiccated (D) or undesiccated (U) thin films of a commercially available epoxy matrix subjected to water (W), salt water (SW), or alkali concrete pore solution (CPS) at either 20 or 60°C, are also presented. It was found that the type of solution did not significantly influence the diffusion behavior at 20°C and that the mass uptake profile was anomalous. Exposure to 60°C accelerated the initial diffusion behavior and appeared to raise the level of saturation. In spite of the accelerated approach, conclusive values of uptake at saturation remained elusive even at an exposure period of 5 years. This finding questions the viability of using short-term thin film results to predict the long-term mechanical performance of FRP materials. © 2013 Wiley Periodicals, Inc.

Simultaneous determination of microcystin contaminations in various vertebrates (fish, turtle, duck and water bird) from a large eutrophic Chinese lake, Lake Taihu, with toxic Microcystis blooms

This is the first to conduct Simultaneous determination of microcystin (MC) contaminations in multi-groups of vertebrates (fish, turtle, duck and water bird) from Lake Taihu with Microcystis blooms. MCs (-RR, -YR, -LR) in Microcystis scum was 328 mu g g(-1) DW. MCs reached 235 mu g g(-1) DW in intestinal contents of phytoplanktivorous silver carp, but never exceeded 0.1 mu g g(-1) DW in intestinal contents of other animals. The highest MC content in liver of fish was in Carassius auratus (150 ng g(-1) DW), followed by silver carp and Culter ilishaeformis, whereas the lowest was in common carp (3 ng g(-1) DW). In livers of turtle, duck and water bird, MC content ranged from 18 to 30 ng g(-1) DW. High MC level was found in the gonad, egg yolk and egg white of Nycticorax nycticorax and Anas platyrhynchos, suggesting the potential effect of MCs on water bird and duck embryos. High MC contents were identified for the first time in the spleens of N. nycticorax and A. platyrhynchos (6.850 and 9.462 ng g(-1) DW, respectively), indicating a different organotropism of MCs in birds. Lakes with deaths of turtles or water birds in the literatures had a considerably higher MC content in both cyanobacteria and wildlife than Lake Taihu, indicating that toxicity of cyanobacteria may determine accumulation level of MCs and consequently fates of aquatic wildlife. (C) 2009 Elsevier B.V. All rights reserved.

How polluted is the Yangtze River? Water quality downstream from the Three Gorges Dam

The concentrations of major anions and cations, nitrogen and phosphorus, dissolved and particulate trace elements, and organic pollutants were determined for the middle and lower reaches of the Yangtze River (Changjiang) from below the Three Gorges Dam (TGD) to the mouth at Shanghai in November 2006. The concentration of dissolved inorganic phosphate (DIP) was constant at a low level of 6-8 mu gP/L, but the concentration of nitrate (NO3-) approximately doubled downstream and was closely correlated with K+. This translated to a daily load of well over 1000 It of dissolved inorganic nitrogen (DIN) at Datong. The average concentrations of dissolved Pb (0.078 +/- 0.023 mu g/L), Cd (0.024 +/- 0.009 mu g/L), Cr(0.57 +/- 0.09 mu g/L), Cu (1.9 +/- 0.7 mu g/L), and Ni (0.50 +/- 0.49 mu g/L) were comparable with those in other major world rivers, while As (3.3 +/- 1.3 mu g/L) and Zn (1.5 +/- 0.6 mu g/L) were higher by factors of 5.5 and 2.5, respectively. The trace element contents of suspended particles of As (31 +/- 28 mu g/g), Pb (83 +/- 34 mu g/g), and Ni (52 +/- 16 mu g/g) were close to maximum concentrations recommended for rivers by the European Community (EC). The average concentrations of Cd (2.6 +/- 1.6 mu g/g), Cr (185 +/- 102 mu g/g), Cu (115 +/- 106 mu g/g), and Zn (500 +/- 300 mu g/g) exceeded the EC standards by a factor of two, and Hg (4.4 +/- 4.7 mu g/g) by a factor of 4 to 5. Locally occurring peak concentrations exceed these values up to fourfold, among them the notorious elements As, Hg, and Tl. All dissolved and particulate trace element concentrations were higher than estimates made twenty years ago [Zhang, J., Geochemistry of trace metals from Chinese river/estuary systems: an overview. Estuar Coast Shelf Sci 1995; 41: 631-658.]. The enormous loads of anthropogenic pollutants disposed to the river were diluted by the large water discharge of the Yangtze even during the lowest flow resulting in the relatively low concentration levels of trace elements and organic pollutants observed. We estimated loads of e.g. As, Pb and Ni to the East China Sea to be about 4600 kg As d(-1), 3000 kg Pb d(-1), and 2000 kg Ni d(-1). About 6000 t d(-1) of dissolved organic carbon (DOC) was delivered into the sea at the time of our cruise. We tested for 236 organic pollutants, and only the most infamous were found to be barely above detection limits. We estimated that the load of chlorinated compounds, aromatic hydrocarbons, phenols, and PAHs were between 500 and 3500 kg d(-1). We also detected eight herbicides entering the estuary with loads of 5-350 kg d(-1). The pollutant load, even when at low concentrations, are considerable and pose an increasing threat to the health of the East China Sea ecosystem. (c) 2008 Elsevier B.V. All rights reserved.