Operationally Efficient Propulsion System Study (OEPSS) data book. Volume 4: OEPSS design concepts

This study was initiated to identify operations problems and cost drivers for current propulsion systems and to identify technology and design approaches to increase the operational efficiency and reduce operations costs for future propulsion systems. To provide readily usable data for the Advanced Launch System (ALS) program, the results of the OEPSS study have been organized into a series of OEPSS Data Books. This volume describes three propulsion concepts that will simplify the propulsion system design and significantly reduce operational requirements. The concepts include: (1) a fully integrated, booster propulsion module concept for the ALS that avoids the complex system created by using autonomous engines with numerous artificial interfaces; (2) an LOX tank aft concept which avoids potentially dangerous geysering in long LOX propellant lines; and (3) an air augmented, rocket engine nozzle afterburning propulsion concept that will significantly reduce LOX propellant requirements, reduce vehicle size and simplify ground operations and ground support equipment and facilities

The effect of zeolite (Clinoptilolite) in removing ammonia lethal concentration in Rainbow Trout (Oncorhynchus mykiss)

Clinoptilolite efficiency on absorption of ammonia in rainbow trout was studied. The fish specimens weighted 9.5-21g and were exposed to four different concentrations of total ammonia as N-NH4 including: 10, 15, 20, and .25mg/l. A group of 13 fish was considered as control. Lethal concentration was determined after 24 hours. Under stable temperature and pH conditions (T= 16±1 C, pH= 7.7±1), the lethal concentration of total N-NH4 was 25mg/l (as ionized N-NH3=0.44mg/l based on temperature and pH). In lethal concentrations of ammonia, different amounts of zeolite (2, 5, 10, 13 and 15g/l) were used. Application of 15g/l of the zeolite prevented mortalities in the fish. A significant difference was found in reduction of total ammonia and total hardness through application of zeolite after 24 hours (P<0.01). The maximum mortalities occurred in early time of experiment. The histopathological lesions of gill, kidney and liver were studied

Prevention of acute ammonia toxicity in beluga, Huso huso, using natural zeolite

This study was accomplished to examine the efficiency of natural zeolite in preventing acute toxicity of total ammonia to Huso huso. The study was performed using Water Static Method in 96 hours. Fish averaged 46 ± 5 g in weight and 22 ± 4 cm in total length were exposed to four different concentrations (15, 30, 50, 75 mgL-1) of ammonia and a group was considered as control. Under stable condition, the lethal concentration of ionized ammonia was 75 mgL-1 in 96 hours. In the lethal concentration of total ammonia, different amounts of 5, 10, 15 g.L-1 granulated clinoptilolite zeolite were used. Results indicated significant differences between treatments and control (p<0.05). By increasing Clinoptilolite zeolite in each treatment, the survival rate of fish also increased significantly (p<0.05). In lethal concentration of ammonia, the use of 15 g.L-1 zeolite could prevent the mortality rate. Histopathological findings showed that major lesions in gill filaments included hemorrhage, hyperemia, hyperplasia, epithelial cells necrosis. There were hemorrhage, hyperemia, degenerated tubules of kidney, expansion of Bowman's capsule in kidney and hepatocytes necrosis in liver

Comparison of the digestive enzyme activities in Artemia urmiana from nauplii to adult stages using different diets

Due to the importance of adult Artemia in aquaculture, information regarding the digestive enzyme activities variation with inexpensive diets has great importance in Artemia at different life stages. In this study, the effect of different inexpensive diets on digestive enzyme activities, including trypsin, amylse and lipase of Artemia urmiana was investigated in different life stages. The experiment was carried out with 5 treatments and each with 2 replicates over 15 days using 5 diets (wheat meal, common carp diet, soy meal, a mixture of soy meal and canola meal (compound diet 1) and a mixture of soy meal and wheat meal (compound diet 2) in a completely random design. Nauplii were introduced to their cultivation environments after hatching and the digestive enzyme activities were measured in days 5, 10 and 15 of the experiment. Positive and significant correlation were observed between the crude protein content of the diets and trypsin activity (0.74), the carbohydrate content of the diets and amylase activity (0.49), and crude fat content of the diets and lipase activity (0.84). The activities of all enzymes were increased with the Artemia development in this study. During the experimental period, the trypsin, activities were increased in all treatments with the exception of wheat meal treatment, amylase activities were increased in all treatments and lipase activities were increased in all treatments with the exception of common carp diet and wheat meal treatments. Digestive enzyme activities were affected by the diets and Artemia life stages. Regarding the increasing digestive enzyme activities until adult stage in Artemia urmiana, using adult Artemia urmiana decreases pressure on resources of Artemia cyst and nauplii in natural environments. In addition, this condition may result in more economic returns and better quality of adult Artemia compared to its cyst and nauplii

Changes of hormones (T3, T4 and cortisol) and ions (Na+ , Cl, K+ ) during smoltification in Salmo trutta caspius Kessler 1877

Salmo trutta caspius is an important and economic fish in the Caspian Sea has several morphological and physiological changes during smoltification. In this study, Hormonal (T3, T4 & Cortisol) and ionic (Na+ , Cl & K+ ) changes in the serum were determined during the period of smoltification in 5, 10, 15 & 20g of hatchery reared salmo trutta caspius in different seasons (spring, summer, autumn & winter). Hormones were measured by Eliza and Radio Immuno Assay, Na+ and K+ using flame photometer, Cl by colorimeter. T3 and T4 were quite high in spring, especially in the juvenile of 20g. Cortisol was quite low in spring and summer in all of weight groups. Ionic changes showed no significant differences with weight, but it was significantly different among seasons. This result suggests that analyzing the plasma thyroid hormones and ionic provide useful information about the optimal time of transferring Caspian Sea trout from fresh water to sea water. It is concluded that the juvenile fish of 20g shows a better smoltification process in the spring

An investigation on relationship of chemical indices of kilka (Clupeonella engrauliformis) with weight loss during cold storage at -18C

We studied the relationship between physical and chemical properties of frozen kilka with weight loss for packed and unpacked products during storage at amal 8 ' C. Statistical analysis of the results including variance, Duncan test and ANOVA showed relationships existed between changes in Total Volatile Nitrogen (TVN), Peroxide Value (PV), pH, moisture, organoleptic properties of frozen packed and unpacked kilka with product weight losses during cold storage at -18°C. The statistical treatment of the results showed that weight losses for packed samples in comparison to unpacked one at the level of P<0.0I was significant. The weight losses, changes of TVN, PV, pH and moisture losses for unpacked samples were 1.5, 1.35, and 4.5, 132 and 1.32 times more in comparison to the packed one, respectively. Also, the statistical analysis of the results showed a correlation between weight losses in unpacked samples of frozen kilka and the measured factors. The results of chemical and physical properties measured for packed samples of frozen kilka during cold storage and their statistical analysis showed a significant correlation P<0.01 between weight losses and the changes in TVN from 7 to 28mg/100gr, PV from 2.28 to 6.01meq/kg, pH from 6.08 to 6.37 and 1.72% loss in the moisture of the samples. According to these results and the organoleptic tests, the shelf life for packed and unpacked frozen kilka in cold storage at 48°C, is recommended 60 and 30 days, respectively

Effect of copper sulphate on behavioral and histopathological changes in roach, Rutilus rutilus caspicus

The research was accomplished in order to study behavioral and histopathological effects of Copper on Rutilus rutilus caspicus under experimental condition. The study was performed using Water Static Method during 96 hours. 15 fish with averaged weight 2±0.5 g in weight were encountered to different concentrations (0, 0.1, 0.2, 0.3, 0.4 mg/l) of Copper. A group of fish was considered as control. Under stable condition and aeration, the lethal concentration was 0.4 mg/l. Results indicated that there was significant differences between treatments when copper concentration increased (p<0.05). It was found that in the high concentration of Copper nominal signs of toxicity such as convulsion, air gulping and flared operculum were observed. Histopathological sings were hyperplasia, edema, hyperemia, hemorrhage, expansion of Bowman’s capsule and hepatocytes necrosis. In control group no lesion was observed

SEX-SPECIFIC RESTORATION OF MK-801-INDUCED SENSORIMOTOR GATING DEFICIT BY ENVIRONMENTAL ENRICHMENT

Despite ample evidence of N-methyl-D-aspartate (NMDA) receptor dysfunction in schizophrenia, no study has addressed the effects of enriched environment (EE) on sensorimotor gating deficits induced by postnatal NMDA receptor blockade. We evaluated the effect of EE on sensorimotor gating (measured by prepulse inhibition, PPI), or on sensorimotor gating deficit induced by the NMDA receptor antagonist (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cy clohepten-5,10-imine maleate (MK-801) in both sexes of Wistar rats. Rats were injected with MK-801 (1 mg/kg) on postnatal days (P) 6–10. EE was provided from birth up to the time of experiments on P28–30 or P58–60. PPI data were collected at three prepulse intensities and then averaged to yield global PPI. MK-801 treatment reduced PPI significantly in both sexes. While EE per se had no significant effect on PPI, it restored MK-801-induced PPI deficit only in male rats. An extended period of EE did not influence PPI deficit in female rats. Our results indicate that postnatal exposure to MK-801 may exert long-lasting effects on neuronal circuits underlying sensorimotor gating. Sex-specific modulation of such effects by EE suggests sexually dimorphic mechanisms are involved. � 2015 IBRO. Published by Elsevier Ltd. All rights reserved