Physico-chemical properties of water in shrimp hatcheries of Choebdeh (Abadan), south Iran

For assessing management efficiency in shrimp hatcheries of Choebdeh (Abadan), we surveyed the physico-chemical properties of water in two culture periods during the years 2001-2002. Different physical and chemical factors were measured in hatcheries under Thai and Philippine management methods. We measured factors such as salinity (17.9-35.3 ppt), BOD5 (6.12-8.72 ppm), DO (10.02-13.7 ppm), COD (4-98.9 ppm), NH3 (0-811A ppb), NO2 (10421 ppb), pH (8.04 -8.68), Turbidity (1-33 NTU), Ca (400.4-620.6 ppm), Mg (1104-1968 ppm), total hardness (6000-9400 ppm) and water temperature {25.4-32.4°C) while no amount of SH2 was found in the water samples. The results of this survey were compared with standard levels and safe ranges for aquaculture activities. Most factors were in standard range with only NH3 and NO2 showing a slight excess in some cases. An ANOVA test showed significant differences in levels of oxygen and COD of the tanks at different sampling times

Assessment of building façade performance in-terms of daylighting and associated energy consumption in architectural spaces

This paper examines the effect of vertical and horizontal shading devices on the quality of daylight in buildings and the associated energy saving. Excessive daylight in architectural spaces contributes negatively to the energy consumption in buildings. Blinds and shading devices are good solutions to attenuate the surplus amount of daylight in spaces. Accordingly, this study evaluates the effect of shading devices on the amount of light flux and the associated solar energy in buildings. It estimates the energy consumption attributed to lighting spaces for three common positions of shading devices. Computer simulation strategy was undertaken to correlate the illuminance level in spaces with room geometry and architectural shading elements. The Holophane model for lighting calculations was used to estimate the average illuminance level on workplane and correlate it with the expected saving energy in buildings. The study concluded that there is an optimal orientation for shading devices that keeps the internal illuminance level within the acceptable range with minimum amount of solar heat gain.Keywords: Shading device, Daylight Illuminance, Heat gain, Computer simulation, Energy consumptio

On the Production of Severely Deformed Workpieces in Large Scales: A Step Towards Industrialization

© 2019, The Author(s). Improvement of the functional properties of aluminium and its alloys by grain refinement is an effective way to increase their applications. The capability of severe plastic deformation methods to produce ultrafine-grained materials has been well established. However, their industrial application is limited because of the required additional equipment and limitation of the product size. Due to the direct extrusion characteristic of the simple shear extrusion (SSE) method and consequently the minimal additional tools and expenses, SSE is a good candidate for commercialization. The aim of this research is to scale up the SSE products to facilitate their potential use in practical applications. To overcome the limitation on the length of the plunger and reduce the load of the SSE process, a design is proposed in the current research. Microstructural investigations and mechanical tests of commercial pure aluminium (AA1050) workpieces confirm the effectiveness of the proposed design on the grain refinement and its capability to reduce the processing load

Growth and survival rates, mean weight, food conversion ratio and total harvest in cultured Shrimp Litopenaeus vannamei in Iran

To introduce Litopenaeus vannamei to Iran as a cultured shrimp species, a experimental study was carried out to assess the effects of different stocking densities on growth rate, mean weight, survival rate, food conversion ratio and the total harvest of L. vannamei. Mee post-larval groups (P1,12) of L. vannamei (pond A: 20 PL/m2, pond B: 30 PL/m2 and pond C: 50 PL/m2) with average size 0.9cm and initial mean weight 0.01±0.005g were used in this study. The experiments were carried out in three replications in 9 earthen ponds each half a hectare in size in Khouzestan province, south of Iran during 110 days. The result showed there was no significant correlation (P>0.05) between stocking density and survival rate in the semi intensive culture condition. Mean survival rate among farms were greatest at the lowest density, where mean survival in pond A, B, and C was 88.6%, 83.3%, 73.3%, respectively but the differences were not significant (P>0.05). The results also showed there was no significant relationship (P>0.05) between growth rate and growth days in each experiment. The mean growth rate/days for ponds A, B, and C were calculated at 0.16g/day, 0.16g/day and 0.15g/day, respectively. The food conversion ratio in the end of the study period for ponds A, B and C was 1.01, 1.17 and 1.2, respectively. Shrimp production increased with an increase in stocking density when farm production at Pond A and B indicated a significant difference (P<0.05) compared to that of the pond C. The total shrimp production for ponds A, B and C was calculated at 2803kg/ha, 3146kg/ha and 3972kg/ha, respectively. The water temperature ranged between 28±3°C to 23±3°C, with the highest in July and lowest in September. Salinity ranged between 25±2ppt to 12±3ppt, pH ranged between 8.6±0.2 to 7.50.4 and dissolved oxygen ranged between 5.8± 0.4ppm to 5.3±0.3ppm throughout the study. The study proved that L. vannamei could adapt to common conditions in Iranian shrimp culture environment and also we showed that the species production was higher than the native species already under culture

Ecological study on rearing shrimp ponds (Litopenaeus vannemei) in Choebdeh Abadan

Following to introduce Vannamei shrimp (Litopenaeus vannamei) into Iran aquaculture industries by fisheries organization its postlarvae were successfully reared in ponds in Bushehr and Choebdeh in Khuzestan. Due to activity of Shrimp site and importance of input and output water quality, this study was done in 11 stations including: two stations in Bahmanshir river, two station in C4 and C5 irrigation canals, six staions in active farms along C4 cannel (Yonesi, Mosavei and Salman Zadeh), and C5 cannel (Mohamadi, Khairi and Ashraf Por) and one staion in output draing were selected. Sampling were carried out from May2009 befor beginning stocking to harvest time in October 2009. Physico- chemical parameters and plankton sampled biweekly and benthic animals and heavy metals were sampled monthly. Some parameters such as pH and temperature by using portable multy parameters and others. Analyzed with standard methods. Heavy metals were measured by plarography method (797 Vamtro). Plankton and benthos samples were studied only in Bahmanshir station. According to results the maximum values for DO (11.1 ppm) PO4 (1.86 ppm) NO3 (8.4 ppm) and TSS (4992 ppm), pH (8.4) NO2 (0.18 ppm) BOD5 (9.06 ppm) were measured. In comparison to aquaculture water quality standards except for TSS in river stations others are located in allowable range. We didn’t observed any main changes in water quality from river to output drainage. The results of biotic parameters in river stations showed that diatoms were the most group of phytoplanktons. Zooplankton groups were Copepods, Rotifera and Protozoa. Tintinids and Nematoda larvae were the most abundant zooplankton. Benthic animals were included nine crustacean species and two annelid species. Isopods with 52% were the most and ant group

A study on immunological factors in white spot vaccinated shrimp, Litopenaeus vannamei in comparison to none vaccinated groups

The aim of this study was to evaluate the efficacy of white spot virus vaccine produced by gamma irradiation in the face of Litopenaeus vannamei in comparison with Gracilaria corticata and Saccharomyces cerevisiae Seven hundred and twenty healthy shrimp SPF L. vannamei subadult with average weight of 10±1.02 g were collected and divided into 8 groups. The first group (T1) was fed with commercial pellet as control. The second group (T2) was fed with S. cerevisiae added to shrimp feed (1 g/Kg), the third group (T3) G. corticata so that algae Gracilaria were dried and added to shrimp feed at the rate of 1500 mg per kg and finally, the fourth group (T4) was vaccination group which the shrimp were exposed to the vaccine and injected intramuscularly gamma irradiant WSSV (1µl/gbw) for 10 days. The shrimps of all groups were then injected with WSSV and maintained for 25 days. Results indicated that the survival rates for groups T4, T3 T2 and T1 were 57.05±3.52%, 22.5±0.5%, 15±1.05% and 00.0±0%, respectively. Ultimately, at the end of the study the shrimp group T4 showed higher hematological data: THC, TPP, SOD, POD and PO. The study concluded that gamma irradiant WSSV is effective immunostimulants in shrimp L. vannamei and the immunity has better performances than those of the G. corticata and S. cerevisiae

A survey on health status of marine fish in Bandar-e-Imam station

Mariculture is one of the most important sub sector fisheries industry in Asia-pacific region. There are over 40 marine fish species commonly cultured, such as groupers (Epinephlus spp.), snappers (Lutjanus spp.) and Asian sea bass (Lattes calcarifer). But this industry in Southeast Asia experienced serious disease problem since the late 1980s. Khouzestan province has a coastal line about 200 km with many Creek and suitable area for Mariculture. Marine fish culture in Khouzestan province in floating net cages was successfully initiated in Ghazaleh Creek following development of Epinephlus coioides artificial seed production in the 1372. This study has been conducted since 1384 to 1387 in Bandar-e-Imam station. The aim of this research project was to determine the health management status in cage and hatchery, identification of marine fish pathogens (Bacteria, Fungi and parasite), examination of heavy metal in cages sediment and test the physico chemical factors of water in cages and hatchery. Different parts of broodstocks body and fingerlings including intestine, gills and body surface were examined. In this study, 18 Genus and species of bacteria such as Vibrio alginolyticus, Vibrio anguillarum, Vibrio splendidus, Vibrio vulnificus, Plesiomonas shigelloides, Aeromonas hydrophila, Aeromonas caviae, Pseudomonas sp. were diagnosed. Also 7 Genus and species of fungi such as: Aspergillus Niger, Aspergillus flavus, Aspergillus fumigatus, Penicillium sp. And Fusarium sp. Were isolated. In this survey following of disease appearance parasites such as; protozoans Amyloodinium sp. And Trichodina sp. In E.coioides and Acanthopagrus latus and Sparidentex hasta, monogean such as Benedenia sp. In E.coioides and S. hasta, isopoda probably Nerocila sp. In nasal cavity of E.coioides and copepods such as: Caligus sp. And Lernanthropus sp. In A.latus and S.hasta were identified. In this study, microorganisms (bacteria, fungi and parasites) isolated from three different marine fishes species, were reported for the first time in Iran. The range of the physico-chemical parameters of water in cages were: DO (5.42-10.24 ppm), BOD5 (1.51-10.24 ppm), No_2 (0.0197-0.89 ppm), No_3 (3.53-11.93 ppm), Po_4 (0.965-6.05 ppm), turbidity (4-58 NTU) and ammonia (0.0008-0.03 ppm). According to the results parameters such as nitrate, nitrite and turbidity were found more than standard levels. Heavy metals: Ni and Pb relatively high observed

Identification and characterization of pathogenic viruses in aquatic animal using advanced techniques in order to develop rapid diagnostic kit (shrimp viral disease kit as well as TSV, HPV and MBV )

Shrimp production increasing rapidly in the world and in2013 the production reaches 4.2 MT. In Iran the shrimp production is under development and estimated in 1393, 20 thousand tons produced. In this regards the important subject is health and disease in shrimp farm. The white spot syndrome virus for second time appears in chabahar and damage many farms. Because the aquaculture activity expand in the world in national, regional and international scale, many emerge disease are endanger. In this regard the viral disease is very important and not only decrease the production but also has a side effect in business and national economy. For control and prevention the viral disease, the accurate methods such as PCR kit were developed. In this project the PCR methods with sensitivity, specificity and efficacy was designed and used for detection viral disease. Many viruses have several serotypes and in different area maybe new serotype induce the disease. For this reason, the specific kit will be design. Three viruses consist of MBV, TSV and IHHNV are very pathogenic in shrimp farm and need the specific PCR kit for detection them. In this project the MBV virus was identified and designs a new primer with Oligo software and the primer amplified a part of DNA with 185 bp in the gel. The specificity and sensitivity of primer were checked by IQ2000 Kit and the primer used for detection unknown samples

Epidemiological study on some environmental and management parameters affecting on WSD occurrence in Fenneropenaeus indicus and Penaeus vannamei

For the first time white spot disease (WSD) was reported in shrimp farms of khoozestan province, in southwest of IRAN in 2002. Then in 2005 the neighbor province, boushehr, was contaminated. In 2008 WSD outbreak reported in sistan-bloochestan province in southeast of Iran. In 2015 all of southern shrimp farms of country except Hormozgan, the middle southern province, which has remained free of WSD, are being contaminated. White Spot disease suspended shrimp culture in thousands hectares of shrimp farms. Considering that white spot disease has not been observed in Hormozgan province yet, the question is; to what extent environmental and management factors participated in preventing WSD outbreak or cause WSD outbreak. In this study (20102012), the effects of environmental factors and management, stressors that decrease immune system function of shrimp are discussed. In addition, the role of pathogen as the main factor of outbreak is discussed. The goal of this study is to define environmental parameters and management practices associates with outbreak of white spot disease in affected provinces and discover reasons of being Hormozgan province free of this disease. In this study the role of the local environmental factors and management practice stressors in susceptibility to WSD was determine. Both the effects of environmental factors in water of ponds including total ammonia, nitrogen, dissolved oxygen, pH, salinity, transparency, and temperature and management issues related to biosecurity are studied. There were overlaps on physical and chemical parameter values obtained in clear areas with contaminated areas .Results of the data analysis suggest that lack of association with WSD incidence was 7 times greater than WSD incidence despite of disease outbreak in sistan-bloochestan province, so other sources of white spot disease virus incidence was suspected in affected areas. Histopathological examinations and polymerase chain reaction (PCR) tests during project performance did not reveal white spot disease virus evidences in post larvae examined from khoozestan province stocked in farms but disease outbreak was happened in that farms , so we suspected to management practice include feed , pond preparation and carrier of disease. Recorded values of temperature and salinity in some months during inspection in Hormozgan province specified stressful condition that may lead to WSD outbreak, however the disease did not appear. Therefore the hypothesis that the water physical and chemical conditions are reasons to prevent disease outbreak in Hormozgan province is being rejected. The policy of Hormozgan’s fishery authorities, to replaced Fenneropenaeus indicus with specific pathogen free Litopenaeus vannamei, that is more resistant to some of diseases, before incidence of WSD in farms and to before being endemic in the Hormozgan province, made an advantage compare to affected southern provinces that introduced Litopenaeus vannamei after WSD prevalence to their farms. However it does not guarantee to maintain current trend of being Hormozgan province farms free of white spot disease. Therefore establishing the principals of biosecurity are strongly emphasized. Strategies taken by the proficient authorities in preparation of SPF shrimp broodstock can be the most important factor in preventing WSD. Regarding biosecurity principals purchased feed must be free of shrimp head powder. Construction the new shrimp farms should be as far as it could be away from contaminated areas

Direct torque control of induction machines utilizing 3-level cascaded H-bridge multilevel inverter and fuzzy logic

This paper proposes the use of a 3-level Cascaded H-Bridge Multilevel Inverter (CHMI) topology which results in further torque ripple minimization compared to the 2-level inverter-based Direct Torque Control (DTC). This is due to the increase in the inverter switching voltage vectors that allows minimization of the torque error. This in turn can reduce the Total Harmonic Distortion (THD) of the output voltage and current as well. This paper also presents two different control methods in selecting the appropriate output voltage vector for reducing the torque and flux error to zero. The first is based on the conventional DTC scheme using a pair of hysteresis comparators and look-up table to select the output voltage vector for controlling the torque and flux. The second is based on a new fuzzy logic controller (FLC) with Sugeno as its inference method to select the output voltage vector by replacing the hysteresis comparators and look-up table in the conventional DTC scheme. The latter has solved the problem of variable switching frequency which is the main characteristic of the former. By using FLC DTC not only the flux ripples reduce significantly but also the THD of the phase current decreases since a more sinusoidal current waveform is achieved. The simulation results have proven that by using the 3-level CHMI, torque ripple reduction is obtained compared to the 2-level inverter-based DTC while fuzzy DTC shows reduction in the stator flux ripples and the THD of the phase current