Disinfection of aquarium effluents by chlorination and UV treatment

The study was conducted to investigate the efficacy of chlorine and UV irradiation in disinfecting aquarium effluent. A non-agglutinating, a virulent strain of Aeromonas salmonicida (NCIMB 11 02) was used as the test organism. Effluents from a fish tank were inoculated with a suspension of test organisms and subsequently treated with different concentrations of hypochlorite and UV irradiation separately and simultaneously. When used alone, 1.0 ppm hypochlorite reduced the viable cell count from 6.5 log to 3.0 log within 20 minutes of contact period. On the other hand, when used in combination with UV irradiation only 0.5 ppm hypochlorite exerted the same bactericidal effect within the same contact period as was observed with 1.0 ppm hypochlorite alone. This result indicated that required dose of disinfectant for the disinfection of aquarium effluents can be considerably reduced when it is used in combination with UV irradiation.

Effect of combined thyroxine and cortisol treatment on hatching of eggs, post-embryonic growth and survival of larvae of Heteropneustes fossilis

In order to record the effects of thyroxine and cortisol (individual/combined) on hatching, post-embryonic growth and survival of larvae of Heteropneustes fossilis, newly fertilized eggs were given bath immersion treatments of L-thyroxine (T sub(4); 0.05 mg/l), cortisol (0.50 mg/l) and T sub(4)+ cortisol (0.05 mg/l+0.50 mg/l) for 15 days. Hatching of eggs, growth and survival of the larvae improved significantly (P<0.001) in the hormone treated groups as compared to those of control. The frequency of deformities was reduced in the combined hormone treatment group. The present observations suggest that the advanced digestive function probably induced by T sub(4)+cortisol treatment might have resulted in improvement in food utilization during the critical phases of first feeding and promoted vital developmental processes resulting in uniform growth, decreased mortality, better survival and transformation of larvae to juveniles. This combined hormone therapy appears to have practical utility in fish hatchery practice for better success in larval rearing.

Pickle curing of fish using tartaric acid and garlic as preservatives

Tartaric acid and garlic have proved highly satisfactory as pickling agents when used in combination, giving fishery products of good appearance, texture, taste and shelf life. Full details of the pickling method are given.

Halichondria sulfonic acid, a new HIV-1 inhibitory guanidino-sulflonic acid, and halistanol sulfate isolated from the marine sponge Halichondria rugosa Ridley & Dendy

A new sulfur-containing guanidino derivative, halichondria sulfonic acid (1) showing anti-HIV-1 activity, and halistanol trisulfate (2) with anti-tumor activity have been isolated from the marine sponge Halichondria rugosa Ridley & Dendy collected in the

Evaluation and comparison of ozone, hydrogen peroxide and physical treatment on fungal infection prevention and hatching rate of Iranian sturgeon (Acipenser persicus)

Ozone due to having low half-life and devoid of environmental harmful effects is recognized as one of the most effective disinfectant and fungicide in aquaculture. The objective of this study is to consider the effects of periodicay ozonation, hydrogen peroxide treatment, and physical treatment capability in hatching rate enhancement. Three concentrations of 0.05, 0.1 and 0.15 ppm ozone (10 min) and peroxide hydrogen with dose of 500 and 1000 ppm in two procedures accompanied with physical treatment and without physical treatment were examined on hatching rate. In the first year, Egg ozonation (0.1 ppm) with physical treatment have been resulted the greatest hatching rate (81.4%). In the second year, egg treatment with 1000 ppm hydrogen peroxide with physical treatment have been showed the greatest hatching rate (78%). Average hatching rate for the blank control treatment (without disinfectin and physical treatment) was 32.7%. From the economic viewpoint, 0.05 ppm ozone with physical treatment, due to considerable minimizing at consumption energy and ozonation system retention costs, indicated as the best treatment than other ozone treatments for fungal control. Very low correlation (r=-0.14) have been observed between hatchery water temperature and fungal infection percentage in control treatment.

Performance of magnesia cements in porous blocks in acid and magnesium environments

The performance of porous blocks containing three different reactive magnesia-based cements - namely magnesia alone, magnesium oxide: Portland cement (PC) in 1:1 ratio, cured in ambient conditions, and magnesia alone, cured at elevated carbon dioxide conditions, in hydrochloric acid and magnesium sulfate solution - was investigated. Different aggressive chemical solution conditions were used, to which the samples were exposed for up to 12 months and then tested for strength and microstructure. The performance was also compared with that of standard PC-based blocks. The results showed the significant resistance to chemical attack offered by magnesia, both alone and with PC blend in the porous blocks when cured under ambient carbon dioxide conditions, and confirmed the much poorer performance of blocks made from PC alone. The blocks of solely magnesia cured in elevated carbon dioxide conditions, at 20% concentration, showed slightly lower resistance to acid attack than PC; however, the resistance to sulfate attack was much higher. © 2012 Thomas Telford Ltd.

Transducer and base compliance alter the in situ 6 dof force measured from muscle during an isometric contraction in a multi-joint limb.

Although musculoskeletal models are commonly used, validating the muscle actions predicted by such models is often difficult. In situ isometric measurements are a possible solution. The base of the skeleton is immobilized and the endpoint of the limb is rigidly attached to a 6-axis force transducer. Individual muscles are stimulated and the resulting forces and moments recorded. Such analyses generally assume idealized conditions. In this study we have developed an analysis taking into account the compliances due to imperfect fixation of the skeleton, imperfect attachment of the force transducer, and extra degrees of freedom (dof) in the joints that sometimes become necessary in fixed end contractions. We use simulations of the rat hindlimb to illustrate the consequences of such compliances. We show that when the limb is overconstrained, i.e., when there are fewer dof within the limb than are restrained by the skeletal fixation, the compliances of the skeletal fixation and of the transducer attachment can significantly affect measured forces and moments. When the limb dofs and restrained dofs are matched, however, the measured forces and moments are independent of these compliances. We also show that this framework can be used to model limb dofs, so that rather than simply omitting dofs in which a limb does not move (e.g., abduction at the knee), the limited motion of the limb in these dofs can be more realistically modeled as a very low compliance. Finally, we discuss the practical implications of these results to experimental measurements of muscle actions.

Relationship between the allelopathic activity and molecular structure of hydroxyl derivatives of benzoic acid and their effects on cyanobacterium Microcystis aeruginosa

The antialgal activities of benzoic acid, 2-hydroxybenzoic acid (salicylic acid), 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, 3,5-dihydroxybenzoic acid and 3,4,5-trihydroxybenzoic acid (gallic acid) were studied on the growth of two strains of Microcystis aeruginosa (toxic FACHB 942 and non-toxic 469). The results showed that the sequence of 50% growth inhibition concentration (ErC50) of 6- compounds for both strains of M. aeruginosa followed the same order: gallic acid > 3,5-dihydroxybenzoic acid > 4-hydroxybenzoic acid > salicylic acid > 3-hydroxybenzoic acid > benzoic acid. The position and the numbers of hydroxy groups between the hydroxy group and carboxyl influenced the antialgal effects of phenolic acids. We also investigated the joint effects of benzoic acid, 4-hydroxybenzoic acid and 3,4,5-trihydroxybenzoic acid on the growth of M. aeruginosa ( toxic FACHB 942). The mixture of phenolic allelochemicals showed the synergistic effects.

Photodegradation of 2-naphthol in aqueous solutions in the presence of humic acid and ferric ions

In this work, the photodegradation of the carcinogenic pollutant 2-naphthol in aqueous solution containing Aldrich humic acid (HA) and ferric ions (Fe(III)) under 125 W and 250 W high pressure mercury lamp (HPML, lambda >= 365 nm) irradiation was investigated. The photooxidation efficiencies were dependent on the pH values, light intensities and Fe(III)/HA concentration in the water, with higher efficiency at pHs 3-4, and 50 mu mol l(-1) Fe(III) with 20 mg l(-1) HA under 250 W HPML. The initial rate of photooxidation increases with increasing, the initial concentration of 2-naphthol from 10 mu mol l(-1) to 100 mu mol l(-1), while do not change at 50 and 100 mu mol l(-1). However, higher removal efficiency of 2-naphthol is achieved at its lower initial concentration of 10 mu mol l(-1), and initial rate of photooxidation is 0.193 mu mol l(-1) min(-1). Dissolved oxygen (DO) plays an important role in the system containing Fe(III)-HA complexes in which Fenton and photo-Fenton reactions were enhanced in the environment. Hydroxyl radicals produced in HA solution with or without ferric ions were determined by using benzene as free radical scavenger and phenol as scavenging products proportional to hydroxyl radicals. By using UV-Vis and excited fluorescence spectrum techniques, the main photooxidation products, which have higher absorption in the region of 240-340 nm, were found, and the mechanisms for the oxidative degradation is proposed.