Efficiency of two rearing environments in culture and effect on growth performance of beluga (Huso huso) were investigated. In accordance two group of three years beluga (Average weight of 9.93±0.305 and 10±0.5Kg) density (0.5 and 25 kg/m2)) with 3 replicate were stocked in two culture environment and reared with formulated diet including protein 43% and energy 22 MJ/kg for 12 month from 2014.6.19 to 2015.9.10 A.D. in the end of rearing period, indices of final weight, final biomass, daily growth and body percent weight fish reared in cement tank (20.1±0.6, 2016.66±5.77, 0.112±0.00239 and 102.35±1.1 kg) were significantly higher than fish reared in POND (17.4±0.4, 1746.66±7.2, 0.082±0.118 and 74.15 ±4.71 kg), respectively) P<0.05). Food efficiency ratio between two group were not significantly different (P>0.05). Result of this study indicated that except of primary cost of building Cement tank, beluga prebroodstocking in cement tank is better than POND for result of increasing of growth, thrift in culture rearing and more effective management.

Iran has limited water resources that require preservation and reducing water loss from reservoirs, especially in arid and semi arid regions. There are a number of methods available for to control water loss from reservoirs and canals. CONCRETE linings in water reservoirs and PONDs are durable, but their efficiency is limited. Geomembrane sheets are another method of controlling leakage from water reservoirs. In this research, high density polyethylene was used to lining a CONCRETE water reservoir to test its suitability for water proofing and chemical resistance. The benefits and drawbacks of this new lining material were investigated in the design, execution and operation stages. Subsequently, the effectiveness of this liner to control water loss was tested under different. The results showed that a geomembrane liner over a CONCRETE lining requires special consideration during design, installation and maintenance and accessories such as pipes and sumps to reduce excessive stress on the liner. The analysis of water leakage from the liner showed that proper design and installation of the liner and accessories reduce water loss about 38% and limit leakage to 16.9 mm/day/m2.

Background: Waste stabilization PONDs are simplest systems applied by human to treat the biological degradable materials. Today, computerized tools and special mathematical modeling is used to manage environmental systems problems. System Dynamics is a system for problems analys is when time is a significant factor. It includes the way action and reaction of system is encountered by external thistles.Methods: After sampling and testing, phosphorus was modeled by using mathematical relationships and system Dynamics method. After making the initial model and its testing, the model was calibrated using three months data from facultative POND in Yazd city in Iran.Results: Algal growth rate, phosphorus settling rate and losses due to algal respiration and excretion were from important agents. Respiration rate of herbivorous zooplankton, non living carbon hydrolysis rate and phosphorous to chlorophyll ratio were from low important agents.Respiration rate of carnivorous zooplankton and phosphorous to carbon ratio were from unimportant agents.Conclusion: In comparison with other models, our System Dynamics Model needs low data. This is also a cheap model and we perceived good operation of it. In sensitive analysis, algal growth rate and phosphorus settling rate were important in phosphorus removal. So, we can manage facultative POND better with increasing retention time in POND. Phosphorous to chlorophyll ratio had low important role in this model. Thus, system can tolerate phosphorous variations in inlet wastewater with sufficient algal growth. Respiration rate of carnivorous zooplankton and phosphorous to carbon ratio do not limit system equilibrium. Ability of the model increases with sufficient retention time and further data. System Dynamics ecological models give useful information for facultative PONDs. It is recommended this model be used for management affairs and overall assessment of facultative PONDs. For more precise assessment, it is apposite to use two or three dimensions models substitute zero dimensions models.

One of the important issues in the production of CONCRETE is environmental variability that affects the CONCRETE and elements constructed from this material. Due to the importance of different characteristics of CONCRETE in short- and long-term conditions, this article aims to investigate the influence of initial temperature conditions of self-compacting CONCRETE on its long-term characteristics and determine the initial optimal temperature of CONCRETE. For these purposes, several experiments under three temperature conditions of 5, 20, and 40 degree-of-Celsius were conducted to evaluate the rheology and mechanical properties of fresh CONCRETE in the range of 7 and 28 days. In these experiments, alternative mineral admixtures of cement such as micro-silica, fly ash, and zeolite were used to build the CONCRETE specimens. Results demonstrate that the mechanical properties of the specimens increase with increasing initial temperature in the short term, while such properties significantly decrease in the long term compared to the specimens constructed under lower initial temperature. Moreover, the fluidity of self-compacting CONCRETE increases with increasing initial temperature.

Rainwater storage is very important as a sustainable and practical solution for managing water resources, especially in places with dry and semi-arid conditions such as Iran. This method has been considered as a strategic solution in response to environmental challenges and agricultural and drinking needs. There are various structures for collecting and storing rainwater, the most important of which is the reservoir in Hormozgan. The possibility of using the rainwater stored in this POND to irrigate urban greenery has been the focus and goal of this research. For this purpose, Bibi POND in Qeshm Island was chosen. For this purpose, the volume of water stored in this POND was calculated. Next, other parks and green spaces around the POND were investigated and their area and details were estimated. The results showed that there are 73 trees and shrubs and about 3400 m2 of green space (grass) in this park and its surrounding area. Estimates showed that the main reservoir of the covered POND and the open side POND are able to store about 400 and 1000 m3 of water, respectively, and this volume of water can supply the water needed for irrigating the green space of the park and the adjacent area in the major part of the year or at least in the stressful time (warm season). This issue will show the unique capacity of such structures for non-drinking purposes in urban environments and therefore should be considered in the planning and management of urban runoff.

In this study, a comprehensive mathematical model is developed to study the water evaporation process and brine concentration in a solar POND to recover the valuable salts in Bandar Imam Petrochemical Company. In this model, the energy source is just solar irradiation. The solar irradiation depends on the geographic characteristics of the location. The present model accounts for heat losses from (the surface of) the POND such as convection, conduction, radiation, and evaporation losses. Also, the wind effect and the variation of the brine physical properties with salinity are considered in the model. The mathematical results are also compared with experimental data. The results show that there are good agreement between the mathematical predictions and experimental data and the developed model can predict the variation of concentration and salt recovery accurately. Finally, by considering all important parameters, the developed model was applied to determine the optimum size of solar evaporation POND based on the concentration and initial volume of brine.

Despite demanding for aquaculture products have been continuing to grow, developing this diverse enterprise is limited by lack of adequate water resources and lands. To overcome these issues, intensive aquaculture facilities could be used with water recirculating or reuse systems. One of these innovative facilities is in-POND raceway system (IPR). IPRs are effective intensive aquaculture facilities for regions with high water consumption and limited land resources and they are categorized as hybrid or integrated systems. In fact, this system overcomes the problems and bottlenecks of each system by combining various features and advantages of other aquaculture systems. These developing facilities are consisting of several rectangular raceways installed in a POND. IPRs design is more efficient than the PONDs and cages due to greater accessibility for feeding, grading, harvesting, and disease treatments and by comparing with other systems, it has significantly more profit and production yield. This study reviews the main components, stocking, feeding, and aquaculture management of fish in IPRs.