Application of Homotopy analysis method to fourth-order parabolic partial differential equations

In this paper, by means of the homotopy analysis method (HAM), the solutions of some fourthorder parabolic partial differential equations are exactly obtained in the form of convergent Taylor series. The HAM contains the auxiliary parameter h that provides a convenient way of controlling the convergent region of series solutions. This analytical method is employed to solve linear examples to obtain the exact solutions. The results reveal that the proposed method is very effective and simple

Effect of different light regimes on the maturational progress of the whitespotted rabbitfish (Siganus sutor)

In this study, the effects of different light regimes on the reproductive activity of a typical Indo-Pacific coral reef rabbitfish, Siganus sutor, were evaluated. Forty-five adult fish were exposed to nine different photoperiod (8L: 16D, 12L: 12D, 16L: 8D) and light intensity (1000, 2000, 3000 lux) combinations with three replicates and five other fishes reared under indoor light condition (Control). Gonadosomatic Index (GSI) and Hepatosomatic Index (HSI) were calculated after 60 days and compared among different experimental regimes in males and females. In the control group, GSI and HSI mean values were 4.67 and 3.24%, respectively, for females and 10.05 and 2.10%, respectively, for males, and these fish showed differences in comparison with the exposed fish. Females kept under 1000 and 2000 lux light intensities had a higher GSI mean value (9.26 and 10.39%, respectively) and also lower average HSI (2.10 and 2.31%, respectively) in 16L: 8D treatment. A similar result was also obtained for males, whereas the 3000 lux light intensity, 8L: 16D day length combination led to more gonadal development (GSIs of 16.41% in females and 12.03% in males). A comparison of results among different photoperiods also confirmed that maturation was induced better in fish maintained under 16L: 8D in both sexes. This investigation revealed the visible role of both photoperiod and light intensity on inducing maturity in the whitespotted rabbitfish, S. sutor. Thus, rearing of adults exposed to an artificial light regime, including 16L: 8D and 2000 lux light intensity, promotes more gonadal development than that occurring in the wild

Comparative effects of pure spirulina powder and other diets on larval growth and survival of green tiger shrimp, Peneaus semisulcatus

This experiment was carried out in Bandargah Station in Bushehr province. Peneaus semisulcatus larvae were fed on Spirulina platensis as supplementation microalgae. In order to use Spirulina platensis in this study, we have to produce biomass and dry production of this microalga. Determination of length and survival rate of Peneaus semisulcatus larvae was carried out as the objective of the study. Treatments including Z plus (as a supplementation without spirulina), M.C.F (as an imported enriched spirulina), the powder combination of Spirulina platensis with Z plus and Spirulina platensis as live food were compared to Cheatocerus microalgae as a control. The experiment was carried out from nauplii stage to early post larvae. The results of the experiment indicated that the powder combination of Spirulina platensis with Z plus treatment has the most survival rate (76.5%). The maximum of length (4.3mm) observed in control (Cheatocerus spp.). The maximum mortality was observed in zoa stage in spirulina microalgae treatment, because the spiral filamentous of Spirulina sp. was large

Evaluation of different dietary protein and energy levels on growth performance and body composition of narrow clawed crayfish (Astacus leptodactylus)

Nine practical diets containing increasing percentages of crude protein (CP) and energy (30%, 35%, 40% and 300kcal/100g, 370kcal/100g and 450kcal/100g) were fed to narrow clawed crayfish (mean individual weight=17±2.3 g) during an 8 week feeding trial. Weight Gain, Feed conversion ratio (FCR), Protein Efficiency Ratio (PER), Net Protein Utilization (NPU), Daily Food Consumption (DFC) and body composition of tail-muscle meat of narrow clawed crayfish were determined. At the conclusion of the experiment, comparing the growth parameters in response to interaction between protein and energy levels demonstrated that dietary number 2 (30/370) resulted in higher WG, NPU, PER, and the lowest FCR whereas dietary number 3 (30:450) showed higher SGR and DFC. Comparison of the body composition results indicates the greatest amount of protein absorption in diet number 2 (30/370). Results from this study indicate that narrow clawed crayfish can be fed a practical diet containing 30% protein and 370 Kcal/100gr. Reducing CP levels in narrow clawed crayfish diets may help reduce operating costs and thereby increase producers’ profits

Species diversity in Iran aquaculture

Species diversity of aquaculture based on introduction of endemic and exotic species, for various object to aquaculture industry. AS FAO reports in 2012, about 558 different aquatic species have been used for aquaculture production. Among these, 130 marine fishes, 169 fresh water fishes, 45 species of migratory fishes, 62 crustacean, 35 aquatic plants, 4 aquatic products (pearl,), 98 invertebrates and finally 15 other aquatics included. Increasing of world aquaculture production depended on species diversity, and exotic species play the highest rank in this field. Aquaculture development program in Iran emphasized special attention on species diversity since last half century. Wide studies and researches devoted on biology, and exotic species. Iran aquaculture industry studied 27 different exotic species, and 28 endemic species for aquaculture development and sea ranching program. In addition, about 250 different ornamental aquatics, mainly non- native included in house- aquariums. Six different exotic species have the main aquaculture production in cold water, warm water and sea water environments. Rainbow trout is the main species in cold- water, while high valued endemic species of Caspian salmon has not any role in aqua culture production. In warm water fish group, chines carps and common carp are main species, but endemic species same as shirbot, Gattan, Benny and Schizotrox have not used in aquaculture production. Despite of wide researches on marine fishes of north and south sea, not endemic fishes included in aquaculture production. The new developing production of marine fish relied on non- native fish. Although specific duration of shrimp culture based on endemic species of Penaeus indicus, it is about of 10 years that shrimp production relied on exotic species of P.vannamei. In case of sturgeon fish, this new enterprise based on endemic species of Huso huso. Finally, the aquaculture industry of Iran same as most other countries relies on exotic species

Effects of different levels of energy and protein sources on the growth performance, feeding, survival rate and the chemical body composition of juvenile Pacific white shrimp (Litopenaeus vannamei)

The present study was carried out in order to establish an economical effective diet for the Pacific white shrimp in the southern part conditions of Iran. Three dietary energy levels (E1=262, E2=312, E3=362 Kcal 100 g^-1 diet) and 6 ratios of fish meal (FM): soybean meal (SBM) [(P1= 100% FM+ 0% SBM), (P2= 80% FM+ 20% SBM), (P3= 60% FM+ 40% SBM), (P4= 40% FM+ 60% SBM), (P5= 20% FM+ 80% SBM), (P6= 0% FM+ 100% SBM)], 18 experimental diets were prepared. Completely randomized design was used to assign 54 polyethylene 300 litre round tanks provided by aeration and was stocked by 19 juvenile shrimp as 3 replicates to each treatment. Shrimps average weight was about 0.77 g at the start. After 56 days culture period, maximum growth and nutritional performance were observed in the P6E1 and P5E1 treatments. In addition, the highest survival rate of the shrimps was observed in the P1E1, P1E2, P3E3 and P5E3 treatments. Results indicated that protein, fat, fiber and ash contents of carcase were significantly affected by the treatments (P<0.05). Results of the present study suggest the replacement possibility of at least 80% of dietary fishmeal by soybean meal in the diet of Pacific white shrimp in the conditions of southern part of Iran

Replacing of live food with artificial diet on growth and survival rates of white leg shrimp (Litopenaeus vannamei) larvae

Replacing live food with artificial diets in aquatic larviculture, especially in shrimp larvae not only is caused convenience feeding, but also in economical view is very important. With this object, in this survey, a density of 100.L -1 white leg shrimp larvae in 9 nutritional treatments each with three replicates were cultured in 20L tanks each one was held with 10L of 30% salty water using one air stone. The larvae were fed 4 times.day-1 with different diets, including live foods (Cheatoceros gracilis and Artemia nauplii), artificial diets (handmade and imported) and different combinations. The results showed that the growth rate and survival percentage in larvae fed with combination feed treatments, were more desirable than those fed with food and feed treatments and feeding with homemade and imported feeds alone, raised high mortality in shrimp larvae during the experiment. Also, it was denoted that even if the zoea larvae has been fed with live food, feeding with 100% artificial diets for the resting larviculture period won't be possible because of decreasing significantly in growth rate, total length and survival percent of shrimp larvae, compare to the other treatments. In addition, replacing partly of live food with artificial diet without adverse affects on growth and survival rates of white leg shrimp larvae will be possible and the observation supported that the handmade feed with given formulation, had more suitable results comparing to the imported one for mixing with live food economically. Therefore, we recommend that a mixture the formulated diet and algae plus Artemia nauplii is used for culturing white shrimp larvae

Analytical solution of BVPs for fourth-order integrodifferential equations by using homotopy analysis method

Abstract:An analytic technique, the homotopy analysis method (HAM), is applied to obtain the approximate analytical solutions of fourth-order integro-differential equations. The homotopy analysis method (HAM) is one of the most effective method to obtain the exact and approximate solution and provides us with a new way to obtain series solutions of such problems. HAM contains the auxiliary parameter ℏ, which provides us with a simple way to adjust and control the convergence region of series solution. It is shown that the solutions obtained by the Adomian decomposition method (ADM) and the homotopy-perturbation method (HPM) are only special cases of the HAM solutions. we have shown that fourth-order boundary value problems can be transformed into a system of differential equations and integro-differential equation, which can be solved by using homotopy analysis method. Several examples are given to illustrate the efficiency and implementation of the method

Effect of Zataria multiflora Boiss essential oil on the growth of Staphylococcus aureus in the light salted fillets of silver carp (Hypophthalmichthys molitrix)

The effects of different concentrations of Zataria multiflora essential oils at concentrations of 0, 0.005, 0.015, 0.045, 0.135, 0.405 and 0.810% on the growth of Staphylococcus aureus were studied in a food model system, light salted fillets of silver carp (Hypophthalmichthys molitrix) at storage temperature of 10ºC for 21 days. The results showed that there was no significant difference in bacterial growth between samples treated with different concentrations of Z. multiflora essential oil and control group immediately post-inoculation. However, there was significant difference in growth of S. aureus between samples treated with concentration of 0.135 of Z. multiflora essential oil and control samples (P0.05) except of 1-day post-storage. The most inhibitorial effects were observed in the samples treated with 0.405% and 0.8 10% of Z. multiflora essential oil up to 9 and 12 days post- storage, respectively

Optimal conditions for tissue growth and branch induction of Gracilariopsis persica

The species Gracilariopsis persica was first described by Bellorin et al. (2008). G. persica grows from late September to July and shows high growth rate from January to May in the Persian Gulf. Tissue growth and branch induction of red seaweed, Gracilariopsis persica from the Persian Gulf investigated under various culture levels of temperature, light intensity, photoperiod, salinity, initial length, propagule density and chemical preservatives. Optimal size of propagules used as seed was 2 cm and faster growth of tissue and branch induction obtained at lower density. The apical part of the G. persica showed as the starting point of growth. The G. persica showed optimal growth in PES medium at 24°C, 60μmol m-2 s-1 light intensity, 12L: 12D and salinity of 39‰. But maximum branch production occurred under condition of 24°C, 20 μmol m-2 s-1 light intensity, photoperiod of 16L: 8D and salinity 39‰. Addition of chemical preservatives of p-hydroxybenzoic acid and potassium sorbate in culture medium showed marginal suppression on tissue growth and branch induction, that suitable for preparation of semi-axenic culture condition