در هنگام جستجو کلمه در قسمت عنوان میتوانید کلمات مورد جستجو را با کاراکتر (-) جدا کنید.
کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Journal of Simulation and Analysis of Novel Technologies in Mechanical Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی:
- چکیده:
- چکیده انگلیسی: Fracture assessment of U- and V-notches is important in mechanical engineering. One can use the J-integral as fracture parameter in order to predict the critical fracture load in notches. The critical value of the J-integral in cracks is a function of the material properties. In notches, however, the material properties as well as the notch dimensions affect this critical value (named fracture toughness). So, one should carry out a complex and time-consuming experiment in order to find the fracture toughness. In this paper, a practical equation has been derived to evaluate the critical value of the J-integral in blunt V-notches under Mode I loading. By means this new expression, only the notch dimensions and the critical value of the J-integral in cracks should be known. In this paper, the effect of the notch angle, the control volume radius to the notch root radius ratio (Rc/ρ), and the Poisson’s ratio on the J-integral and the critical value of the J-integral have been studied. Results have shown that by increasing the notch angle and the Poisson’s ratio, the fracture toughness decreases. However, the fracture toughness increases by increasing the Rc/ρ ratio.
- انتشار مقاله: 05-07-1394
- نویسندگان: F. Noori-Azghad,H. Khademizadeh,E. Barati
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Fisheries Sciences
- نوع مقاله: Journal Article
- کلمات کلیدی: Growth,Immune response,Rainbow trout,Disease resistance,Plant protein,Blood indices
- چکیده:
- چکیده انگلیسی: The aim of this study was to examine the effects of replacing fish meal with plant sources on growth performance, immune responses, hematological parameters and disease resistance in rainbow trout. In this study, mean of initial body weight of fish was 15±2 g and the experiment was carried out for a period of 60 days. Four experimental diets were formulated to replace 0, 40, 70 and 100% fish meal with plant protein sources (wheat gluten, corn gluten and soybean meal). According to results, higher plant protein inclusions (70 and 100%) resulted in undesirable effects on growth, nutritional indices, serum total immunoglobulin and alternative complement activity (P < 0.05). Otherwise, results suggested that it is possible to replace 40% of fish meal with plant counterparts without any noticeable negative effects on growth and humeral immune parameters (lysozyme activity and total antibody) (P > 0.05). Furthermore, replacement of fish meal with plant sources in all treatments had no significant effects on blood parameters (hematocrit, hemoglobin, white blood cells, hetrophil and lymphocytes count). Finally, no significant differences were observed in fish mortality after 15 days of challenges with Yersinia ruckeri among treatments (P > 0.05).
- انتشار مقاله: 12-10-1396
- نویسندگان: R. Jalili,A. Tukmechi,N. Agh,F. Noori,A. Ghasemi
- مشاهده
- جایگاه : پژوهشی
- مجله: Archives of Razi Institute
- نوع مقاله: Journal Article
- کلمات کلیدی: Medicinal herbs,Histopathology,Cineol,Oncorhynchus mykiss,Streptococcus iniae
- چکیده:
- چکیده انگلیسی: Some of the medicinal plants have antibacterial contents and appear to be proper alternatives for antibiotics in the treatment of streptococcal disease, which causes plenty of mortalities in fish farms annually. Therefore, this study investigated the therapeutic effect of Aloe vera and Salvia officinalis hydroethanolic extracts against Streptococcus iniae in rainbow trout. Plant extracts components were analyzed by Gas chromatography-mass spectrometry method and tested in vitro against S. iniae by disk diffusion assay. In in vivo, 480 rainbow trout (10±0.1 g) were distributed in 9 groups (with 3 replication), and all groups (except for the first group as the negative control that was injected with 100 µl of physiologic serum) were injected by 100 µl of LD50 (3.66×108.5CFU/ml) of S. iniae suspension, intraperitoneally. The fish of groups were treated by A. vera and S. officinalis extracts in doses 0 (positive control group was fed by commercial diet without plant extract), 0.5, 1, and 1.5% (supplemented diet) and 80 mg/kg body weight erythromycin for the next 10 days. At the end of the study period, tissue samples of the gills and livers of all groups were taken for the histopathological lesion assay. The results showed that A. vera and S. officinalis had antibacterial components as Cineol, and S. iniae was sensitive to both A. vera (MBC=4.067 mg/ml) and S. officinalis (MBC=5.185 mg/ml) extracts. At the end of the treatment period, there were no significant differences among erythromycin, A. vera (1.5%), and A. vera (1%) in terms of the mortality of the infected fish (P˂0.05). Moreover, A. vera (1.5%) showed a significantly lower mortality rate, compared to the positive control (P˂0.05). A. vera (1.5%) was the best group to moderate all histopathological lesions, compared to other groups. Accordingly, A. vera (1.5 %) is useful to treat streptococcosis (caused by S. iniae) and alter gill and liver histopathological lesions in rainbow trout.
- انتشار مقاله: 04-06-1397
- نویسندگان: A. A. Tafi,S. Meshkini,A. Tukmechi,M. Alishahi,F. Noori
- مشاهده