ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Publication Date: 2020-06-15
    Description: The main purpose of this paper is to obtain analytical solutions for radiative transfer equations related to the vertical structure of accretion discs with finite optical depth. In the non-grey atmosphere, we employ the optical-depth dependent Eddington factor to define the relationship between the mean intensity and radiation stress tensor. Analytical solutions are achieved for two cases: (i) radiative equilibrium, and (ii) a disc with uniform internal heating and both cases are assumed to be in local thermodynamical equilibrium (LTE), too. These solutions enable us to study probable role of scattering and disc optical depth on the emergent intensity and other radiative quantities. Our results show that for the first case, the surface value of mean intensity with constant Eddington factor is three times larger than that with variable factor. Moreover, scattering has no role in the vertical radiative structure of discs with the assumptions of the first case. On the other hand, for the second case, we encounter reductions in all radiative quantities as the photon destruction probability decreases (which is equivalent to increasing scattering). Furthermore, for both cases with total optical depth less than unity, the outward intensity towards the polar direction becomes less than that from the edges of disc which is contrary to limb-darkening. At the end, we apply our results to find the spectrum from accretion systems, based on two dynamical models. Consequently, we can see that how the total optical depth varies with frequency and causes remarkable changes on the emergent spectra.
    Print ISSN: 0035-8711
    Electronic ISSN: 1365-2966
    Topics: Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    facet.materialart.
    Unknown
    In:  http://aquaticcommons.org/id/eprint/22638 | 18721 | 2018-05-07 22:26:25 | 22638 | Iranian Fisheries Science Research Institute
    Publication Date: 2021-07-08
    Description: Mnemiopsis leidyi (Comb Jelly) is an exotic species which has not been reported from the Caspian Sea till 1999, but it was observed and reported from the southern coasts of Caspian Sea in 1999. Invasion of the Mnemiopsis leidyi to the Caspian Sea pelagic ecosystem has been one of the main difficulties in the past decade. Mnemiopsis leidyi has been brought from the Black Sea to the Caspian Sea by ballast water of ships and it has settled in the southern Caspian Sea through the time. There is a little information regarding the microbial flora in comb jelly but a large number of comb jelly carry natural flora and pathogens located in the coastal waters such as Aeromonas and Vibrio. However, it might have been entered into the Caspian Sea many years ago, but it has recently caused excessive reduction in kilka fish stocks because it is considered as a food competitors for them. The comb jelly may also carry some new microorganisms like parasites and microbial flora to the Caspian Sea. This study was carried out to investigate the parasites and bacterial flora of B. ovata and M. leidyi as probable dangers for the Caspian Sea ecosystem.
    Keywords: Biology ; Ecology ; Parasites ; Bacteria ; Beroe ovata ; Mnemiopsis leidyi ; Caspian Sea ; Iran
    Repository Name: AquaDocs
    Type: article , TRUE
    Format: application/pdf
    Format: application/pdf
    Format: 733-736
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2021-07-16
    Description: The national research plan with title of "Study on health status of Iran Coldwater hatchery and rearing farms" was done in order to identification and tracking of main causative agents of recent mortality in Iran Coldwater hatchery and rearing farms and recognize of infected zones and design of landscape distribution of Epizootic Coldwater fish diseases in the country. This plan was conducted parallel and in same time in some polar provinces of Coldwater fish production such as Mazandaran, Gilan, Ardebil, West Azerbaijan, East Azerbaijan and Kurdistan in three years from 2006-2008. In this regard, about 23,21 and 20 farms in Mazandaran province, 30 farms in West and East Azerbaijan and Kurdistan provinces and 19 farms in Gilan and Ardebil were selected as randomly and tracking were done yearly from 2006-2008. This research was conducted according to regular planning consists of farms visit that was done according to statistical plan and completion of Questionnaires and sampling. The findings in Mazandaran province revealed that fish infections background and infectious diseases were increased in period of 2006-2008. In fact, 56% of all fish farms in 2006, 71% in 2007 and 85% in 2008 were recorded as infected farms. In other side, average weight of fish final products was more 500gr in consume market. So, regarding to long period of fish culture in mentioned fish occurrence of more morbidity could be expected. The streptococcus infections were most important fish bacterial diseases that have more incidence and pathogenicity in collected questionnaires. Also it revealed more occurrences in summer season in above 15oC temperature in affected fish farms. Also, Enteric Redmouth Disease (ERM) and Saprolegniasis were reported as second and third degree in examined farms. Meanwhile, findings of control, prevention and treatment of our survey revealed that using of antibiotics and detergent materials were increased in mentioned province. Indeed, 34.7% of all fish farms in 2006, 71.4% in 2007 and 75% in 2008 have applied treatment operation and using of detergent materials in affected farms. In other side, frequent using of Erythromycin antibiotic was reported several times in 2008 so fish farmer faced to Bacterial resistance and should be using from Florfenicol as alternative antibacterial. Also, in feed sampling from all fish farms about 3 fish farms in 2006 and 5 fish farms in 2008 were faced with food poisoning that originated from high TVN and peroxidase in fish food consumed. These farms revealed mass mortality that stopped after change feeding regime. In conclusion absence of fish health management could be considered as main agent of mentioned mortality in Mazandaran province. The findings of our survey in West and East Azerbaijan and Kurdistan revealed that absence of sufficient experiences in fish farmers and their neglect from water quality concepts, farm cleanness, using of suitable detergent materials for fish ponds and instruments and disability in continuous monitoring of physic-chemical factors of consumed water could be considered as most important problems. So, fish morbidity and mortality, growth decrement and low production rate were expected. Unfortunately, despite the occurrence of infectious and non- infectious diseases in examined fish farms, there were no documents and information about diseases history, clinical signs in dead fish, feeding regime, fish mortality (rate of daily mortality, age and weight of moribund fish), treatment operation, drugs usage, growth rate, physico-chemical factors and fish density. So planning for control and prevention of mentioned diseases were unsuccessful in affected fish farms. Also, occurrence of some epizootic fish viral diseases such as VHS, IPN and IHN were observed frequently with mass mortality about 40100% in some examined fish farms that produced some tragic economic lost in the mentioned provinces. Similarly, some bacterial, fungal and parasitic diseases were observed repeatedly in some inspected farms such as Flavobacterium, streptococcus infections. Also, some unknown causative agents in parasitic diseases were observed several times such as Dactylogyrus, Gyrodactylus, Ichthyophthirius multifiliis, Trichodina, Chilodonella, Diplostomum and fungal diseases such as Saprolegniasis. In conclusion it seems that absence of fish health management, inadequate rate of hygienic technical services, absence of quarantine programs for transfer of new eyed-eggs, juvenile and live broodstocks packages without health certificates from authorized organizations, uncontrolled entry of foreign eyed-eggs (France, Denmark, Australia and Armenia) and neglect in using of suitable detergent materials for fish ponds, instruments, consumed water and infected eggs, not screening of broodstocks in hatcheries could be considered as most important causative agents in occurrence of infectious diseases and main problems in affected farms in mentioned provinces. Similarly, our findings in Gilan and Ardebil provinces revealed that their problems were similar to other provinces. In fact, neglect in establish of necessary Infrastructures in fish farms and dereliction in health management concepts could be considered as main reasons of occurrence of fish infectious and non-infectious diseases in studied fish farms in mentioned provinces. In fact, often fish farms visited hadn't suitable structures without control and prevention approach. There were not observed detergent using, quarantine programs and prevention methods. Entrance of unknown persons, birds and wild animals were ordinary in mentioned farms. Unfortunately level of farmer’s knowledge was low and no training courses and extension programs were planned by authorized organizations. Meanwhile, food storages were unsuitable and food packages were stored in inappropriate situation so poisoning conditions were increased in examined farms. In conclusion it could be finalized that Coldwater fish farms in Gilan and Ardebil provinces situated in insufficient position and correction of current situation are needed urgently. In final elicitation, it would be mentioned that lack of basic infrastructures could be introduced as most important reasonfor spread of diseases, mortality and related economic losses in studied provinces. Therefore, attention to environmental affairs and access to Sustainable Development are recommended. Also consideration of biosecurity regulations and health management concepts would be important requirements for modification and reformation of Coldwater fish farms in examined provinces towards A Better Tomorrow.
    Keywords: Aquaculture ; Iran ; Mazandaran Province ; Gilan province ; Ardebil Province ; West Azerbaiejan Province ; East Azerbaiejan Province ; Kordestan provinceColdwater ; Fish farm ; Health situation ; Health management ; Diseases ; Survey ; Rearing ; Hatcheries ; Enteric redmouth disease ; Saprolegniasis ; Bacterial ; Florfenicol ; Sampling ; Dactylogyrus ; Gyrodactylus ; Ichthyophthirius multifiliis
    Repository Name: AquaDocs
    Type: monograph
    Format: application/pdf
    Format: application/pdf
    Format: 250
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    facet.materialart.
    Unknown
    Iranian Fisheries Science Research Institute | Tehran, Iran
    In:  http://aquaticcommons.org/id/eprint/25216 | 18721 | 2018-09-05 16:41:56 | 25216 | Iranian Fisheries Science Research Institute
    Publication Date: 2021-07-16
    Description: The project was carried out between March of 2007 and November of 2009.Five laboratories of research center (Clinical pathology, Plankton, Molecular genetics, Pollutants, Analysis Instrument were selected for accreditation. The main stages for establishment of the system consisted of: 1-Conducting a gap analysis to compare the present state of the laboratories with ISO/IEC 17025 Training 2 General requirements for the competence of testing and calibration laboratories Validation of methods Estimation of uncertainty Internal audits 3- Performing of technical and management requirements 4-Submit of quality manual to Iran Accreditation System (IAS) in order to accredit In January of 2010 the laboratories were accredited by Iran Accreditation System (IAS). The main results were including: 1-Increase the accuracy of measurement 2-Improvement of the Repeatability and Reproducibility of the test methods 3-Traceability and standardization of test methods 4- Calibration of measurement instruments 6- Updating of test methods 7-Standardization of physical condition of the laboratories 8- Getting the certification from Iran Accreditation System (IAS).
    Keywords: Information Management ; Iran ; Standardization ; ISO/IEC 17025 ; Laboratory ; Accreditation ; Calibration ; Ecological institute of Caspian sea
    Repository Name: AquaDocs
    Type: monograph
    Format: application/pdf
    Format: application/pdf
    Format: 63
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2021-07-16
    Description: Bacterial flora and parasitic fauna of M. leidyi an exotic invader jelly fish to Caspian Sea ecosystem and B. ovata to Black sea an alternative biological control agent was studied. During summer 1382 to spring 1383, using routine Bacteriological work. 72 sample of sea water Caspian Sea obtained from depth 20 and 50 meters, 36 sample of M. leidyi from depth 20 meters, 10 sample of B. ovata and 3 sample of sea water (Black sea) were collected and according to Bacteriological was studied. 216 sample of M. leidyi from depth 10 to 50 meters of Caspian Sea and 47 sample of B. ovata from Black and Marmarreh Sea (Turkey) were collected and was studied. In this study no parasite from was identified in M. leidyi (Caspian sea) but 64 percentage and 73 percentage of B. ovata (Marmarreh and Black sea respectively) contaminated to Trichodina ctenophore at varians concentration B. ovata of Black sea (130 min 1050 max) and B. ovata Marmarre sea (420 min 2100 max). While B. ovata kept at high salinity of 21 ppt was more contaminated with this pretrichial protozoan (Trichodina) than in low salinity (12/5 ppt). in comparision of bacterial flore in two cetenophore (M. leidyi and B. ovata) was observed that some of bacteria such as micrococcus sp, Aeromonas sp. Bacillus coagulans in both ctenophore and some other bacteria such as Agromobacterium and chromobacterium only observed in B. ovata but other researcher have reported fram Caspin sea and some of bacteria to specific Shewanella , Vibrio harveiy and bacillus linens was observed in B. ovata . Of course specific bacteria cannot transfer to Caspian Sea (different of salinity black sea (2/1%) to Caspian Sea (1/25 %)). Therefore if B. ovata to introduce to south Caspian Sea for biological control population M. leidyi. it is necessary at first some of viral pathogen in aquatic animal (fish) such as VNN, IPN,IHN,VHS,SVC was studied and then with confidence 95% non-infestation B. ovata to viruses and pass from bath anti parasite and anti-bacterial must be introduce to south Caspian sea.
    Keywords: Ecology ; Health ; Iran ; Caspian Sea ; Black sea ; Parasite ; Bacteria ; Beroe ovata ; Mnemiopsis leidyi ; Agromobacterium ; Chromobacterium
    Repository Name: AquaDocs
    Type: monograph
    Format: application/pdf
    Format: application/pdf
    Format: 55
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    facet.materialart.
    Unknown
    Iranian Fisheries Science Research Institute | Tehran, Iran
    In:  http://aquaticcommons.org/id/eprint/25699 | 18721 | 2018-10-10 08:54:02 | 25699 | Iranian Fisheries Science Research Institute
    Publication Date: 2021-07-16
    Description: Mullet and mullet products have considerable economic importance at a regional level, especially around the Caspian Sea. The leaping mullet constitutes an important part of their production. This study is the first detailed work on the age and growth of the leaping mullet (Liza saliens) from September 2012 to March 2013 in the Southern coast of the Caspian Sea. Age and growth determinations were based upon the scale samples taken from 102 fish. Marginal increment analysis was used to validate age determination. The back-calculated lengths stage estimated from the scale showed no differences between in this study. The maximum age of leaping mullet in the Southern coast of the Caspian Sea was 5 years for males and 6 years for females. The von Bertalanffy growth functions were Lt=30.415(1-e-0.275(t+0.645)) for males and Lt=34.832(1-e 0.211(t+1.009)) for females. A large spread and length overlap characterized the age groups. The estimated Length Weight relationships were common for the two sexes (W=0.079L3 ). The slope (b) values of the length-weight relationship showed that weight of leaping grey mullet in Mazandaran increased associated with length in isometric. The mean condition factor for males, females and all specimens were determined as 0.908, 0.900 and 0.897, respectively. According to sex groups, the mean condition factor of males was slightlyhigher than that of females. The total length for leaping grey mullet was determined as 23.3 cm.
    Keywords: Aquaculture ; Iran ; Caspian Sea ; Age determination ; Fish scale ; Liza saliens ; Back calculation
    Repository Name: AquaDocs
    Type: monograph
    Format: application/pdf
    Format: application/pdf
    Format: 66
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    facet.materialart.
    Unknown
    Iranian Fisheries Science Research Institute | Tehran, Iran
    In:  http://aquaticcommons.org/id/eprint/25529 | 18721 | 2018-10-05 15:51:43 | 25529 | Iranian Fisheries Science Research Institute
    Publication Date: 2021-07-16
    Description: Indicator of bacteria such total coliforms and fecal coliforms are one of the most important environmental factors that effect on water quality. Haraz river is one of three rivers in north of country and it originate from central Alborz. Overall, discharge of unborn sewage, agriculture pesticides, seasonal raining was caused decreasing of quality of the river. Therefore, quality and quantity of the grandwater, surface water and sewage in different zone of this river such Mangol dam is necessary. In this study, total coliforms and fecal coliforms and nematode ovary in 13 stations of Haraz including Sorkhrood, Klodeh, Amol Esar Town, Helomsar, Mangol dam, Karesang, Jalav bridge, Norroud, Tehran 115, Larijan, Abeask, Lasem, Lar (pleur) were surveyed. ECC Chrome agar was used for counting and isolation of coliforms groups and nematode ovary counting was done as formal – ether sedimentation method. The results showed that maximum and minimum of total coliforms in surface water was observed in Sorkhrood (9.4 CFU/100ml) and Lasem (4.2CFU/100ml) and also maximum and minimum of fecal coliforms in Sorkhrood (3/2 CFU / ml) and Lasem (1/1CFU/100ml) respectively. Maximum and minimum of these bacteria in ground water were Abeask (4 CFU /100ml) and Helomsar (9/1 CFU/100ml) (for total coliforms) and Abeask (7/1 CFU/100ml) and Helomsar, Klodeh and Larijan (2/1 CFU/100ml) (for fecal coliforms) respectively. Maximum and minimum of total and fecal coliforms in sewage were Norroud (1/3 CFU/100ml) and Amole Esar Town (2/2 CFU/100ml) (for total coliforms) and Norroud (6/1 CFU/100ml) and Amole Esar Town and Tehran 115 (2/1 CFU/100ml) (for fecal coliforms) respectively. Ovary of Nematode in sewage was 30 and 124 in Norroud and Amole Esar Town respectively. The conclusion of this study was showed that quality of Haraz is low level and not proper for drinking and swimming.
    Keywords: Health ; Iran ; Mazandaran province ; Haraz River ; Mangal Dam ; Surface water ; Groundwater ; Sewage ; Coliforms ; Nematodes ; Bacteria ; Agriculture ; Sedimentation
    Repository Name: AquaDocs
    Type: monograph
    Format: application/pdf
    Format: application/pdf
    Format: 48
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...