On a wave dissipation method for offshore aquaculture areas

This paper describes a proposed flexible floating structure to provide a method of wave dissipation for an aquaculture area. The structure is mainly made of net-tubes which are filled with floating balls. A number of ways of placement for the flexible structure have been investigated in hydraulic model studies and the results are presented in this paper. From these studies it is concluded that if a certain number of rows of these floating structures are connected with proper spacings, then the complex floating structure will serve as a good wave sheltering system for an offshore aquaculture area.     

Supplementation of Slow‐Release Melatonin Improves Recovery of Ovarian Cyclicity and Conception in Summer Anoestrous Buffaloes (Bubalus bubalis)

The role of melatonin as a protective neurohormone against restoring cyclicity in summer anoestrous animals in photoperiod species has gained wider acceptance. This study was designed to uncover the evidence the slow‐release melatonin (MLT) has on initiation of ovarian cyclicity and conception rate (CR) in summer anoestrous buffaloes. Thus, buffaloes diagnosed as summer anoestrous (absence of overt signs of oestrus, concurrent rectal examination and radioimmunoassay for serum progesterone at 10 days interval) were grouped as untreated (Group I, sterilized corn oil, n = 8) and treated (Group II, single subcutaneous injection of MLT @18 mg/50 kg bwt in sterilized corn oil, n = 20). Animals treated and detected in oestrus were artificially inseminated (AI) followed by division into Group III (second dose of MLT on 5th day post‐AI, n = 8) and Group IV (no melatonin administration, n = 10). Blood samples were collected at 4 days interval for estimation of serum MLT, progesterone and oestrogen using radioimmunoassay kit. Mean oestrous induction rate (OIR), oestrous induction interval (OII), interoestrous interval (IOI) and CR were estimated. Compared to control, concentration of melatonin was significantly (p < 0.05) higher in treated group ranging from 14.34 ± 1.72 to 412.31 ± 14.47 pg/ml whereas other two hormones did not show any concentration difference. Melatonin‐administered buffaloes showed significantly (p < 0.05) higher (90%) OIR with OII of 18.06 ± 1.57 days. Results showed improvement in conception rate in buffaloes administered with post‐insemination melatonin. It can be concluded from the study that slow‐release melatonin supplementation restored cyclicity in summer anoestrous animals resulting in improvement in conception rate in buffaloes.     

Optimization of lipase-catalyzed synthesis of octyl hydroxyphenylpropionate by response surface methodology

The ability of immobilized lipase Candida antarctica (Novozyme 435) to catalyze the direct esterification of hydroxyphenylpropionic acid and octanol in a solvent-free system was investigated in this study. Response surface methodology (RSM) and five-level-four-factor central composite rotatable design (CCRD) were employed to evaluate the effects of synthesis parameters, such as reaction time, temperature, enzyme amount, and pH memory, on percentage molar conversion of phenolic acid esters. Reaction time, temperature, and enzyme amount were the most important variables. On the basis of canonical analysis and ridge max analysis, the optimum synthesis conditions with 95.9% molar conversion were reaction time of 58.2 h, temperature of 52.9 degrees C, enzyme amount of 37.8% (w/w), and pH memory of pH 7.     

Simultaneous Absorption of SO2 and NO in a Stirred Tank Reactor with NACLO2/NAOH Solutions

The wet scrubbing combined SO_x/NO removal system is one ofthe advanced air pollution control devices. This study tries tounderstand the kinetics of the absorption in the system. The absorption of SO₂ and simultaneous absorption of SO₂ and NO, whose concentrations are typical for flue gases emittedfrom coal-fired power plants, in a stirred tank reactor with NaClO₂/NaOH solutions were carried out at 50 °C.The liquid-side and gas-side mass transfer coefficients of the system were determined. The results indicate that the absorptionof SO₂ is completely gas-film controlled if the NaOH concentration is greater than 0.1 M or the NaClO₂ concentration is greater than 0.2 M. Adding SO₂ would decrease the absorption rate of NO; however, the addition of NO has no effect on the absorption rate of SO₂. The existence of O₂ has no significant effect on the absorption rate of SO₂ and NO in the combined SO_x/NO removal tests.