71 research outputs found

    Kinematical analysis of the nutation speed reducer

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    This paper discusses the development of a Nutating Speed Reducer (NSR) which is characterized by high reduction ratio, high tooth contact ratio, very high torque to weight/volume ratio, quiet and smooth operation under load and very high efficiency. All of these advantages are due to the presence of conjugate face-gear pairs, which incorporate each other, which called nutating/rotating gear mechanism. Details of the NSR, its kinematics, gear tooth load capacity, and mesh efficiency are explained. The NSR component speeds and speed reduction ratios of the NSR are calculated. Effect of the varying nutation angles on the geometry of the NSR is discussed and compared

    Preliminary cultivation of silver bream (Sparidentexhasta) in earthen pond using available artificial fish feed in Chowibdeh site-Abadan southern Iran

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    Possibility of rearing silver bream (Sparidentex hasta) in the earthen pond was experimented using 2 types of available artificial trout feed (FFT and GFT1). The experiment was carried out in 2 phases in Shahid-Kiani Extension Shrimp Farm in Chowibdeh Shrimp Site-Abadan Southern Iran, and earthen ponds with 0.25 ha. Area were used for both phases of the study. Juvenile fish of 3.2 g initial weight with the density of 9324 ind./ha. Were stocked for 196 days in the first phase. The initial weight, stocking density and rearing period of the fish in the second phase were 108.60 g, 9800 ind./ha. And 237 days respectively. Maximum amount of WG, FCR, PER and SVR of the fish in the first phase of the study were 100.12 g, more than 6, 0.38 and 55.32% respectively. WG and SR of the fish in the second phase respectively were 417 g and 20.74%. The Salinity of pond water was in the range between 9 and 22 ppt, and the water temperature was between 8.3 Φ―C (mid December morning) and 34.8 Φ―C (early Sep....

    Pliminary rearing of sea bream (Acanthapagrus latus) in the ground pond in the Choweibdeh (Abadan) using available artificial feed

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    This study has been carried out to evaluate the possibility to culture shanak (yellow fin seabream: Acanthopagrus latus) fish in the ground pond. The study including two experiments. In the first experiment two commercial available feeds (403 as shrimp food and F.F.T as trout food both produced by Chineh company) are used to evaluate the growth performance of the bream Juvenile produced artificially in the Bandar Imam Mariculture Research Stationin weghing 2.72- 3.54 g. To perform the first experiment 6 ground ponds each with 0.25 ha area are used as replicates 3 ponds randomly allocated to each food. 5000 in dividual juvenile fishes are stocked in each pond. After 116 days rearing period well growth performances are achieved for both foods with no significant difference (P 0.05) between them, although better growth performances are observed for F.F.T food. The final weight (WE), SVR ,FCR and SGR of shanak for F.F.T food respectively were 23.29 Β± 11.14, 95.98% Β±0.78, 1.39 Β±0.26 and 3.47Β±0.23 where for 403 food were 22.08Β±9.95 , 89.67%Β±8.75 , 1.53Β±0.12 and 3.25Β±0.33 respectively. In the second experiment in which only trout food was used the target was to examine the growth parameters of shanak juvenile in a full rearing period (198 days) in the ground pond. Juvenile fishes with 36.53 g were used with same methods adopted for the first experiment. The final weight of 206.3 g is achieved by 89.35% SVR and 1.92 of FCR. Results of this experiment showed that the growth quickly improved with fast rate along with the increment of temperature and salinity up to 25ΒΊC and 14 ppt respectively. There after by the raising the temperature and salinity more than 25 ΒΊC and 14ppt respectively the growth reduced

    Determination of the best protein to energy level for rearing silver sea bream (Sparidentex hasta) in the fingerling stage

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    This research has been carried out to study on the effect of different levels of protein (45, 50, 55 and 60%) and energy (20, 22 and 24 KJ/g) on growth performances, survival rate, nutrition factors and chemical composition of juvenile fish of silver sea bream (Sparidentex hasta) wheighing 27 grams.The experiment was done with 12 treatments and 3 replicate for each treatment. The rearing period was 56 days in 300 liter polyethylene tanks (with 200 liter water volume and with water exchange of 1 liter/min). In each tank eighteen fish were stocked. Biometry was done in every two weeks. At the end of experiment one fish was used for chemical analysis of body. Finally, with consider to obtain results from Two-way ANOVA, the 50% of protein level and 22 KJ/g of energy level is suitable for making nutrition for this species

    Effects of dietary protein and energy levels on the growth, feed utilization and body composition of yellow fin seabream Acanthopagrus latus juvenile

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    A feeding trial was carried out where, three protein concentrations [45%, 55% and 65%, crude protein (CP)] was fed to yellow fin sea bream (Acanthopagrus latus) fingerlings at three dietary energy concentrations [20, 22and 24 Kj g-1 crude energy (CE)] ,to determine the protein and energy requirement for this species. Triplicate groups of 20 fish (average weight 12Β±.2g) was each stocked in 300-L fiberglass tanks and fed twice a day to apparent satiation. After 8 weeks, the survival was independent of the dietary treatments, but the average fish weight gain (AWG), specific growth rate (SGR), food conversion ratio (FCR) and feed efficiency ratio (FER) were significantly affected by dietary protein (P 0.05). PER, PR, GER, VSI and IFR increased with the increase of energy from 20 to 24 Kj g-1 at the same protein level. Carcass moisture, fat and ash contents were affected by dietary protein and energy levels (P<0.05). Carcass energy content increased with increasing dietary energy, but carcass moisture was decreased with increasing dietary energy from 20 to 24 Kj g-1.. It was concluded that the optimum dietary protein and energy level for growth of juvenile yellow fin sea bream maybe 562-574.7 g kg-1diet and 21.9- 24.56 Kj g-1 respectively

    Kinematical analysis of the nutation speed reducer

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    This paper discusses the development of a Nutating Speed Reducer (NSR) which is characterized by high reduction ratio, high tooth contact ratio, very high torque to weight/volume ratio, quiet and smooth operation under load and very high efficiency. All of these advantages are due to the presence of conjugate face-gear pairs, which incorporate each other, which called nutating/rotating gear mechanism. Details of the NSR, its kinematics, gear tooth load capacity, and mesh efficiency are explained. The NSR component speeds and speed reduction ratios of the NSR are calculated. Effect of the varying nutation angles on the geometry of the NSR is discussed and compared
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