Fishing with artificial light has become one of the most advanced,efficient,and common methods for the night-time purse seining in Vietnam.This study evaluated the radiation spectrum,CIE chromaticity coordinates,corre...Fishing with artificial light has become one of the most advanced,efficient,and common methods for the night-time purse seining in Vietnam.This study evaluated the radiation spectrum,CIE chromaticity coordinates,correlated color temperature(CCT),catch rate,fuel consumption,and CO_(2)emissions when using Light emitting diode(LED)lamps(0.196 kW)in comparison with the use of metal halide(MH)lights(1 kW)in the offshore purse seine fishery in Quang Tri province,Vietnam.The fishing efficiency of the purse seine fishing boats using LED lamps has increased 1.58 times in catch rate than MH lights,although the energy consumption of LED lamp is 4 times smaller.Fuel consumption of boats per trip using LED lamps was one third of that using MH lights.The use of LED reduced the radiation spectrum,especially the intense UV radiation which negatively affects the health of fishermen.This study also showed the potential of CO_(2)emission reduction up to 1.09 tons of CO_(2)per trip per boat from the use of LED lamps in the offshore purse seine fishing boats.展开更多
Fishermen generally use light as a common way to attract fish in the fishing industry. This study aimed to design a model of an underwater fishing using Light Emitting Diode (LED) lamp which is less costful and suitab...Fishermen generally use light as a common way to attract fish in the fishing industry. This study aimed to design a model of an underwater fishing using Light Emitting Diode (LED) lamp which is less costful and suitable for fishermen of Tanzania. Most fishermen currently use kerosene based lamps like candela which consumes lots of energy leading to high cost in terms of money used to regenerate the energy. This running cost automatically rises up the price of fish in the market. Thus with the use of LED lamp the cost will be reduced. The findings from this study showed that the LED lamp consumes little amount of energy (energy saving) compared to candela lamp which consumes 6 liters of kerosene per 36 hours which is equivalent to three nights, while the LED lamp takes 7 batteries at once for 36 hours. The 6 liters of kerosene cost around 7 USD and that of 7 batteries cost is near 2 USD. The LED lamp can be accessed by only 15 USD the price which is nearly half the price of the candela lamp. The candela lamp in the market is sold around 31 USD. This shows that LED lamp is more efficient in terms of conserving energy and cost effective than candela lamp. It is recommended that fishermen in the fishing industry in Tanzania should employ the usage of underwater LED fishing lamps as they are energy efficient. This will help the fishermen of Tanzania to undertake the fishing activity at low cost which will result to the decrease of price of fish in the market. This shows that this LED lamp has high efficiency and effectiveness to be used by fishermen compared to traditional method used by majority of them.展开更多
The operating circuits for LED （light emitting diode） lamp composed of diodes and DC capacitors only are proposed. The proposed circuit is based on a double-voltage rectifier circuit and a Cockcroft-Walton circuit. ...The operating circuits for LED （light emitting diode） lamp composed of diodes and DC capacitors only are proposed. The proposed circuit is based on a double-voltage rectifier circuit and a Cockcroft-Walton circuit. The circuit can operate LED without flicker, and is free from switching noise since high frequency switching circuit is not used. To replace an AC capacitor by a DC capacitor for the ballast, a diode is connected across the capacitor in parallel, and the operating voltage of LED unit is kept at the value greater than the peak voltage of the input power source. The circuit realizes high efficiency and high input power factor compared with the operating circuits on the market. Cockcroft-Walton-type circuit can operate many LED devices in series connection. Series connection is preferable for fabricating LED unit of a constant voltage characteristic. Moreover, fairly flat waveform of LED operating current is realized by Cockcrofl-Walton-type circuit, even though capacitor ballast is used.展开更多
基金This study was funded by the Hue University DHH 2019-02-109 grant for the project:“Study on the applied LED lamps in offshore seine fishery in Quang Trịprovince”from Hue University,Hue city,Vietnam.
文摘Fishing with artificial light has become one of the most advanced,efficient,and common methods for the night-time purse seining in Vietnam.This study evaluated the radiation spectrum,CIE chromaticity coordinates,correlated color temperature(CCT),catch rate,fuel consumption,and CO_(2)emissions when using Light emitting diode(LED)lamps(0.196 kW)in comparison with the use of metal halide(MH)lights(1 kW)in the offshore purse seine fishery in Quang Tri province,Vietnam.The fishing efficiency of the purse seine fishing boats using LED lamps has increased 1.58 times in catch rate than MH lights,although the energy consumption of LED lamp is 4 times smaller.Fuel consumption of boats per trip using LED lamps was one third of that using MH lights.The use of LED reduced the radiation spectrum,especially the intense UV radiation which negatively affects the health of fishermen.This study also showed the potential of CO_(2)emission reduction up to 1.09 tons of CO_(2)per trip per boat from the use of LED lamps in the offshore purse seine fishing boats.
文摘Fishermen generally use light as a common way to attract fish in the fishing industry. This study aimed to design a model of an underwater fishing using Light Emitting Diode (LED) lamp which is less costful and suitable for fishermen of Tanzania. Most fishermen currently use kerosene based lamps like candela which consumes lots of energy leading to high cost in terms of money used to regenerate the energy. This running cost automatically rises up the price of fish in the market. Thus with the use of LED lamp the cost will be reduced. The findings from this study showed that the LED lamp consumes little amount of energy (energy saving) compared to candela lamp which consumes 6 liters of kerosene per 36 hours which is equivalent to three nights, while the LED lamp takes 7 batteries at once for 36 hours. The 6 liters of kerosene cost around 7 USD and that of 7 batteries cost is near 2 USD. The LED lamp can be accessed by only 15 USD the price which is nearly half the price of the candela lamp. The candela lamp in the market is sold around 31 USD. This shows that LED lamp is more efficient in terms of conserving energy and cost effective than candela lamp. It is recommended that fishermen in the fishing industry in Tanzania should employ the usage of underwater LED fishing lamps as they are energy efficient. This will help the fishermen of Tanzania to undertake the fishing activity at low cost which will result to the decrease of price of fish in the market. This shows that this LED lamp has high efficiency and effectiveness to be used by fishermen compared to traditional method used by majority of them.
文摘The operating circuits for LED （light emitting diode） lamp composed of diodes and DC capacitors only are proposed. The proposed circuit is based on a double-voltage rectifier circuit and a Cockcroft-Walton circuit. The circuit can operate LED without flicker, and is free from switching noise since high frequency switching circuit is not used. To replace an AC capacitor by a DC capacitor for the ballast, a diode is connected across the capacitor in parallel, and the operating voltage of LED unit is kept at the value greater than the peak voltage of the input power source. The circuit realizes high efficiency and high input power factor compared with the operating circuits on the market. Cockcroft-Walton-type circuit can operate many LED devices in series connection. Series connection is preferable for fabricating LED unit of a constant voltage characteristic. Moreover, fairly flat waveform of LED operating current is realized by Cockcrofl-Walton-type circuit, even though capacitor ballast is used.
