Cosmological constant influence on cosmic string spacetime

We investigate the line element of spacetime around a linear cosmic string in the presence of a cosmological constant. We obtain the metric and argue that it should be discarded because of asymptotic considerations. Then a time dependent and consistent form of the metric is obtained and its properties are discussed.Comment: 3 page

Knowledge-Based Collaborative Lean Manufacturing Management (KBCLMM) system

The objective of this research paper is to demonstrate the application of hybrid Knowledge-Based System, Gauging Absences of Pre-Requisites (GAP), and Analytic Hierarchy Process (AHP) approaches for selecting the improvement programs for Collaborative Lean Manufacturing Management (CLMM) System.In this research, a generic Knowledge-Based System is developed to measure the level of CLMM adoption in automotive manufacturers compared to the ideal system. Using the embedded GAP and AHP technique, the key lean manufacturing improvement programs can be prioritised by using both qualitative and quantitative criteria.The analysis covers the planning stage of the KBCLMM. The utilisation of the approach is demonstrated with an illustrative example

Production of monosex female population of rainbow trout by use of 17-B estradiol as direct method

In many species of finfish, females exhibit higher growth rates than males and achieve larger sizes. In addition, in some species, males mature before reaching marketable size. Therefore, there is great interest from the fish farmers to produce all-female stocks. In this project tried to reversing the sex of rainbow trout larvae by 17 estradiol and direct method, further more finding the optimum dose of this natural estrogen for endocrine sex reversion of Rainbow trout (O. mykiss). Four experimental treatments were designed with doses of 10, 20, 30 and 40 mg/kgf. Trout which treated with 40 mg/kgf yielded 96% female and greatest growth

Comparison of growth and survival rate between import and native rainbow trout (Oncorhynchus mykiss)

Rainbow trout is only species of cold water fishes which is rearing and propagation in Iranian fishery farms. Along of develop aquaculture industries increase request of best produces such as trout eyed eggs and larva. For this reason fishery farmers must be to provide that the way of import of other countries, such as: Denmark, Norway and France. As for this importance subject and unknown basic information about preference ratio for doing it, we needed to study about that to answer the suppliant questions. In this study carried out 3 test groups (3 treatments with 3 repetitions) and compared specific growth rate (SGR), condition factor (CF) and survival rate (SVR) between in this groups. Statistical analysis were significantly difference of increase rate of length and weight in French group with other groups (p<0.05). Compared of main factors (SGR, CF, SVR) in French test group were significantly difference with other groups (p<0.05). Survival rate percentage in Iranian treatments (SVR=%67) were significantly with the others (p<0.05). This ratio respectively in Danish and French treatment was %54 and %48

Investigation of breeding and culture in Iranian cichlid (Iranocichla hormuzensis) as endemic and ornamental species

Iranian Cichlid is an invaluable ornamental species which is domesticated in Iran and called Iranocichla hormuzensis scientifically, is living in the Hormoz zone, Shahou River (between Bandar Abbas and Haji Abad). The first phase of the research project started in September of 2012 and lasted about 18 months, focused on adapting the wild cichlids to cope with the aquarium environment. Therefore, about 63 male and female of Iranian cichlids collected from the natural habitat, Shahou River, then moved to the nearest city, Bandar Abbas to and released in aquariums which were filled by water of River where they were living. After few days they moved to “innovative aquaculture technologies research station” and reared in 100 liter glass tanks to monitor their behaviors. By initial days, the Cichlids seemed to be stressed out significantly, they were flashing, hitting them to the aquarium, trying to jump out and get discolored due to strange environment. By days, the stressful treats decreased and the experiments coped with the new environment. At the next step, schools of 5-7 fish organized to pear up. The mortality rate collected daily and accidental biometry recorded fortnightly. The rearing temperature adjusted and was stable at 37˚C. Finally, the Cichlids were completely adopted and prepared for mating and breeding

Cryopreservation of rainbow trout (Onchorhynchus mykiss) semen

Breeding has moved beyond the point of simply propagating random stock. Genetic potential can be improved by establishing and crossing genetically defined strains, crossing species and manipulating gametes. Some of these activities require cryopreservation of semen. Cryopreserved sperm could also be a means of exchange of genetic material between locations and populations when transportation of live fish is restricted. In this study we had a survey on rainbow trout sperm quality in Genetic and Breeding Center for Coldwatwr Fishes, Shahid Motahari, Yasouj. Then Cryopreservation trials on rainbow trout (Oncorhynchus mykiss) sperm were carried out using six basic extenders. Egg batches of 25 g were inseminated with semen frozen in five 0.5-ml straws. Thowing temperature of cryopreserved sperm also was tested. In anather trial we investigate different cryoprotectant. The result showd that the best period for sperm collection in this center was from Novamber to January. The best extender based on sperm motility parameters were extender 2 and 1 with 57.2 and 56.9% fertilisatin rates, respectively. So this two extender were used in the further experiments. The best thowing temperathre was 25°C in 30s. Testing different cryoprotectant, adding 10% methanol to extender 1 gave the highest fertilization rate (64.6%) among cryoprotectant that used with this extender. In the other extender (2) adding 5% DMSO and mixture of 5% DMSO and 1% glycerol gave the highest fertilization rates (64.8% and 67.0%, respectively). In conclusion using extender 1 and 2 with mentioned cryoprotectant and thowing rate of 25°C in 30 s was recammended for rainbow trout sperm cryopreservation