Chemical and nutritional quality of fermented fish silage containing potato extracts, formalin or ginger extracts

Fermented fish silages were prepared from whole tilapia (Oreochromis niloticus), 15% molasses and 5% Lactobacillus plantarum starter culture. After fermentation for 72 h, potato extracts (PE), formalin or ginger extracts (GE) were added at 5 ml/kg silage as proteolytic inhibitor or lipid antioxidant, and incubated at 30°C for 30 days. The effects of presence or absence of these additives on various protein and lipid quality parameters were periodically examined. PE had a slight and insignificant effect on protein solubilization and proteolytic activity; hence it was not effective as a proteolytic inhibitor. Formalin prevented further hydrolysis of protein and reduced ammonia production. GE proved effective as an antioxidant in fermented tilapia silage, as the thiobarbituric acid value remained low after 30 days' incubation. The tilapia silages were incorporated into dry tilapia diets and the digestibility of nutrients determined. The formalin-treated tilapia silage diet gave significantly reduced (P < 0·5) digestibility of dry matter, nitrogen or lipid compared to the control, PE-treated or GE-treated silage diets.     

Narrow-linewidth fibre laser with integral fibre grating

The fabrication and operation of an Nd3+-doped silica single-mode fibre laser using a distributed fibre grating as the feedback element is reported. The laser had a threshold of less than 2mW, a slope efficiency of 19% and an output bandwidth at the lasing wavelength of 1.084?m of 16 GHz, significantly narrower than the conventional cavity design.     

Efficient diode-pumped CW and Q-switched single-mode fibre laser

We report the efficient operation an Nd3+-doped silica single-mode fibre laser pumped by a GaAlAs laser diode. A CW output power in excess of 1 mW at 1.088 ?m has been obtained with a slope efficiency of 33%. Q-switched operation of this device is also reported.     

Continuous-wave oscillation of a monomode thulium-doped fibre laser

Laser emission in the wavelength band 1.88-1.96 μm has been observed in a monomode fibre doped with thulium. When pumped with a dye laser at 797 nm an absorbed threshold power of 21 mW and a slope efficiency of 13% were obtained     

Diode-laser-pumped Nd3+-doped fibre laser operating at 938 nm

We report the efficient diode-laser-pumped operation of an Nd3+-doped single-mode fibre laser at 938 nm on the three- level transition 4F3/2?4I9/2. An output power in excess of 3 mW has been obtained with a threshold of 1.9 mW.     

Single-longitudinal-mode operation of an Nd3+-dopedfibre laser

Report the first operation of an Nd³⁺-doped monomode fibre laser oscillating in a single longitudinal mode. The laser incorporated an integral fibre grating used as a narrowband reflector. The lasing linewidth was measured as 1.3 MHz FWHM as a wavelength of 1082 nm