Input-output relationship and economics of pangas monoculture and carp-pangas polyculture in two districts of Bangladesh

An attempt was made to study the input-output relationships and economics of pangas monoculture and carp-pangas polyculture in Bangladesh. By analyzing the data collected from 50 pangas farms and 55 carp-pangas farms, the study has investigated the production systems of two technologies and the effects of fingerling stocking and applications of feed and fertilizer on fisheries income. The data were collected from the fishermen of Trishal and Bhaluka of Mymensingh district, and Kahaloo and Adamdighee of Bogra district during 2001-02. For pangas monoculture, the stocking density was 31,561 per ha while it was 55,017 per ha in carp-pangas polyculture. Most of the farmers used urea, TSP and lime before stocking. Rice and wheat bran happened to be the most common feed ingredients for both types of culture in general. Other important ingredients used were mustard oil-cakes, rice polish, wheat flour, fish meal, bone meal, soybean meal and poultry litter. In terms of quantities, rice bran and wheat bran dominated the farmers list. Rice and wheat bran together constituted about 60% of all studied feeds. Feed cost constituted 59.13% of total costs for pangas monoculture and 67.44% for carp-pangas polyculture. Per ha productions of pangas and carp-pangas in a single culture cycle were 15,508 kg and 19,745 kg, respectively. Per ha gross profits were estimated to be Tk 310,311 and Tk 464,418 for pangas monoculture and carp-pangas polyculture, respectively. Net profit appeared to be Tk 264,216 per ha for pangas monoculture and Tk 416,509 per ha for carp-pangas polyculture. The BCRs calculated were 1.46 and 1.68 for monoculture and polyculture, respectively. The break-even costs per kg of fish were estimated at Tk 36.93 for pangas and Tk 30.93 for mixed species which was much lower than the prices the producers received. Break-even productions were estimated at 10,702 kg per ha for pangas monoculture and 11,784 kg per ha for carp-pangas polyculture. Fingerling and feed cost, and pond size significantly explained the variation of income from pangas monoculture. These factors have significantly influenced the income from the crop. Functional analysis shows that 1% increase in the feed cost might increase 0.51% of pangas income and 0.41% in carp-pangas income. No other inputs had shown this much of responses to increasing income from a fish

Impacts of technological interventions on fish production and biodiversity of seasonal floodplains in Bangladesh

The Community-based Fish Culture in Seasonal Floodplains and Irrigation Systems (CBFC) project is a five year research project supported by the Challenge Program on Water and Food (CPWF), with the aim of increasing productivity of seasonally occurring water bodies through aquaculture. The project has been implemented in Bangladesh, Cambodia, China, Mali and Vietnam, where technical and institutional options for community based aquaculture have been tested. The project began in 2005 and was completed in March 2010. The objective of the study was to determine the impacts of technological interventions in the floodplains on fish yield and biodiversity benefiting the poor fisher folk and other community people. Technological interventions for fish culture in the floodplains included (a) the installation of low-cost large meshed bamboo fencing at water inlet and outlet points, and setting of ring culverts for maintaining suitable levels of water for fish culture without hampering the production of rice in the upland areas of the floodplains (b) stocking of larger fingerlings at suitable stocking densities of endemic (rohu, catla, mrigal) and exotic (silver carp, bighead carp, common carp/mirror carp) species at 31-48 kg/ha (c) post stocking management; use of extra fencing during over flooding and mobile guarding using boats (d) harvesting management; regulations in harvest for certain period, use of multiple harvesting techniques. These interventions were carried out through CB participation with initial technological and financial support from the Challenge Program Project (CP35).Flood plains, Freshwater aquaculture

Optimization of dose of methyltestosterone (MT) hormone for sex reversal in tilapia (Oreochromis niloticus L.)

This paper describes the optimization of dose of methyltestosteronei (MT) hormone for masculinization of tilapia (Oreochromis niloticus). Five treatments (i.e. T1 T2, T2, T4 and T5) with different doses such as 0, 40, 50, 60 and 65 mg of MT hormone were mixed with per kg of feed for each treatment and fed the fry four times a day up to satiation for a period of 30 days. The stocking density was maintained 10 spawn/liter of water. The growth of fry at different treatments was recorded weekly and mortality was recorded daily. At the end of hormone feeding the fry were reared in hapas fixed in ponds for another 70 days and at the 100th day the fish were sexed by the gonad squashing and aceto-carmine staining method. The analysis of growth data did not show any significant variation in length and weight of fish among the different treatments. High mortality of fry ranging 66% to 81.6% was observed in different treatments and highest mortality was observed during the first twelve days of the experiment. The sex ratio analysis showed that T2 (40 mg/kg) and T5 (65 mg/kg) produced 93.33% of sex reversed male and T3 (50 mg/kg) and T4 (60 mg/kg) produced 96.66% sex reversed male, and these ratios were significantly (p<0.05) different from 1:1 male: female sex ratio. The control, T1 (0 mg/kg) contained 43.33% male progeny. From these results it is suggested that either 50 mg/kg or 60 mg/kg of MT with a feeding period of 30 days could be considered as an optimum dose for masculinization of tilapia (O. niloticus)

Evaluation on knowledge extraction and machine learning in resolving Malay word ambiguity

The involvement of linguistic professionals in resolving the ambiguity of a word within a particular context will produce a concise meaning of the words that are found in the lexical knowledge based collection. Motivated from that issue, we employed lexical knowledge and machine learning approach which includes the integration of data or/and information from the lexical knowledge based, that is Malay collections which linked to the ambiguous words. We used the most open class word and removed the stop words from the targeted sentences. Experiments have been conducted with and without lexical knowledge on 50 ambiguous words. The Word Sense Disambiguation (WSD) method is determined by machine learning, corpus based approaches namely Malay-Malay corpus and English-Malay corpus. The results show that the proposed method has improved the precision in resolving ambiguity.Keywords: ambiguity; lexical knowledge; machine learning; Malay wor

МОЛЕКУЛЯРНАЯ КЛАССИФИКАЦИЯ ШТАММОВ ECHINOCOCCUS GRANULOSUS ОТ КРУПНОГО РОГАТОГО СКОТА В ЛИВИИ

This study demonstrates the distribution of various E. granulosus strains in sheep, cattle and camel. The common sheep strain G1 is mainly found in sheep and cattle, but also parasitized camels. In contrast, the camel strain G6 is found mainly in camels and rarely in sheep and cattle. However, the study also revealed the possible presence of cryptic species that are closely related to both genotypes in livestock of Libya as evident by high mutations in several specimens. Based on the occurrence of overlapping hosts of E. granulosus in Libya, more research on the transmission cycles and genotypes of E. granulosus in Libya is required. In addition, it is suggested that surveys on potential intermediate hosts, including in humans with dogs as the major final host in Libya using higher resolution molecular tools such as microsatellite markers is recommended.В данном исследовании представлено распространение различных штаммов E. granulosus овцы, крупного рогатого скота и верблюда. Обычный вид овечьего штамма G1 обнаруживают, в основном, у овец и крупного рогатого скота, однако верблюды также могут быть заражены этим штаммом.Напротив, верблюжий штамм G6, чаще всего, находили у верблюдов и реже у овец и крупного рогатого скота.Однако, в ходе исследований установлена вероятность наличия криптических видов, тесно связанных с обоими генотипами крупного рогатого скота в Ливии, что является подтверждением высокого уровня мутаций у некоторых видов.Исходя из того, что на территории Ливии отмечается преобладание хозяев штамма E. granulosus, необходимо провести дополнительные исследования циклов передачи инвазии и генотипов E. granulosus. Кроме того, рекомендуется провести обследование потенциальных промежуточных хозяев, включая частных владельцев собак, являющихся дефинитивными хозяевами, используя при этом молекулярные устройства высокого разрешения, такие как микросателлитные маркеры

Direct Torque Control System and Sensorless Technique of Permanent Magnet Synchronous Motor

AbstractThe direct torque control theory has achieved great success in the control of induction motors. However, in the DTC drive system of Permanent Magnet Synchronous Machine (PMSM) proposed a few years ago, there are many basic theoretical problems that must be clarified. This paper describes an investigation about the effect of the zero voltage space vectors in the DTC system of PMSM and points out that if using the zero voltage space vectors rationally, not only can the DTC system be driven successfully but also the torque ripple is reduced and the performance of the system is improved. This paper also studies the sensorless technique in the DTC system of PMSM and configures the DTC system of PMSM with sensorless technique including zero voltage space vectors. Numerical simulations and experimental tests have proved the theory correct. In the condition of sensorless, the DTC system of PMSM is wide-rangely speed adjusting, and the ratio of speed adjustment is 1:100

Thermochemistry and Kinetics of the Thermal Degradation of 2-Methoxyethanol as Possible Biofuel Additives

Oxygenated organic compounds derived from biomass (biofuel) are a promising alternative renewable energy resource. Alcohols are widely used as biofuels, but studies on bifunctional alcohols are still limited. This work investigates the unimolecular thermal degradation of 2-methoxyethanol (2ME) using DFT/BMK and ab initio (CBS-QB3 and G3) methods. Enthalpies of the formation of 2ME and its decomposition species have been calculated. Conventional transition state theory has been used to estimate the rate constant of the pyrolysis of 2ME over a temperature range of 298–2000 K. Production of methoxyethene via 1,3-H atom transfer represents the most kinetically favored path in the course of 2ME pyrolysis at room temperature and requires less energy than the weakest C α − C β simple bond fission. Thermodynamically, the most preferred channel is methane and glycoladhyde formation. A ninefold frequency factor gives a superiority of the C α − C β bond breaking over the C γ − O β bond fission despite comparable activation energies of these two processes. © 2019, The Author(s).Scopu