Size related feeding patterns and electivity indices of silver barb (Barbodes gonionotus Bleeker) from a pond, Bangladesh

The feeding patterns with respect to quality and quantity of food of silver barb, Barbodes gonionotus varied with their size and development. The results indicated that the fish in the size group I (7-25 mm TL) were fairly omnivore with particular liking for rotifera, green and blue-green algae while the size group II (25.1-44 mm TL) and III (44.1-55 mm TL) were omnivore with higher tendency of feeding on debris, aquatic plants, green algae, blue-green algae and rotifera. However, the fish of the size group IV (55.1-80 mm TL) were found to be herbivore with feeding preference for aquatic plants, green and blue-green algae. In all the size groups, debris was the most dominant food item. Feeding preference of the fish showed clear ontogenetic shift. The electivity indices revealed that the fish were selective feeder

Study of Thyristor Controlled Series Capacitor (TCSC) as a useful FACTS Device

For transmission of large amounts of electric power, AC in the overwhelming majority of cases is the established as well as the most cost effective option at hand. In cases of long distance transmission, as in interconnection of power systems, care has to be taken for safeguarding of synchronism as well as stable system voltages in the interconnection, particularly for extreme load conditions and in conjunction with system faults. Use of Thyristor Controlled Series Capacitor (TCSC) as Flexible AC Transmission System (FACTS) device brings a number of benefits for the user of the grid, all contributing to an increase of the power transmission capability of new as well as existing transmission lines. These benefits include improvement in system stability, voltage regulation, reactive power balance, load sharing between parallel lines and reduction in transmission losses

An analysis of selecting proper locations for installment of wind power plant considering terrain effect

This paper presents the analysis of wind speed data of eight different sites collected from the Meteorological Department of Bangladesh by choosing the proper sites at best possible seasons of the year at different heights with the terrain effect consideration to show the prospect of utilizing the wind power by installing wind turbine effectively. This proposal is expected to make the best use of reasonable wind speed available in these sites for particular seasons of the year to extract power to contribute by reducing country's power crisis. Again the proposed system can be of hybrid type (i.e. solar-wind or wind-tidal) to make the best use of the plant when there is not adequate wind speed to extract power from it

An analysis & design on micro generation of a domestic solar-wind hybrid energy system for rural & remote areas - Perspective Bangladesh

Utilization of renewable energy resources have been the most important & prospective field to seek new energy sources to meet up the increasing demand in power all over the world specially in a developing country like Bangladesh. Among the renewable resources, wind & solar being the most popular ones due to abundant, ease of accessibility and convertibility to the electricity. This paper presents the analysis and design of a hybrid solar-wind system for micro generation for domestic purpose in the rural & remote areas of our country where continuous power supply from central grid has been a great is problem and sometimes for some remote places it's economically not viable at all as far as our country is concerned. We propose such a hybrid system which is expected to run effectively under a microcontroller to utilize the maximum possible solar & wind resources to reduce the demands on national grid for on-grid region as well as to supply power to those places where there is no grid line (i.e. off-grid region)

Distribution, prevalence and intensity of protozoan and monogenean parasites of carp fingerlings in selected nursery ponds

An experiment was carried out on the distribution, prevalence and intensity of infestation of protozoan and monogenean parasites of carp fingerlings in two selected areas of Bangladesh. Six hundred and forty fingerlings of seven species viz. Catla calla, Hypophthalmicthys molitrix, Labeo rohita, Ctenophalyngodon idella, Cyprinus carpio, Barbodes gonionotus and Cirrhinus cirrhosus from different nursery ponds of Shambhuganj, Mymensingh, and Santaher, Bogra were examined during this investigation. This study revealed that carp fingerlings carried a large number of protozoan and monogenean parasites. Different protozoan parasites viz Trichodina domerguei, Trichodina reticulata, Myxobolus koi, Chilodonella cyprini and monogenean parasites such as Dactylogyrus extensus, Dactylogyrus catlarius and Dactylogyroides tripathi were identified in the experimental fishes throughout the study period. It has been observed that distribution, prevalence and intensity of parasite in carp fingerlings are species and zone specific. In case of C. cirrhosus, the highest prevalence of protozoan parasite viz Trichodina domerguei were 93.75% and 75.92% in Santhahar and Shambhuganj area respectively. Irrespective of host, the most prevalent ectoparasite was Dactylogyrus extensus, followed by Myxobolus koi, Chilodonella cyprini and Dactylogyroides tripathi. Relatively higher mortality of carp fingerlings was found at younger stage. The highest prevalent parasitic species was identified as Trichodina domerguei followed by Trichodina reticulata and Dactylogyrus catlarius were found 93.75% in Cirrhinus cirrhosus, 68.75% in Cyprinus carpio and 39.44% in Hypophthalmicthys molitrix respectively

Changes in soil organic matter, plant nutrients and system productivity under conservation agricultural practices in the rice-jute cropping system

Soil organic matter (SOM) is central to soil quality and nutrient cycling. In Bangladesh, depletion of soil fertility is a serious threat to sustainability of agricultural production due to high cropping intensity and agriculture practices based on conventional tillage and residue removal (Rijpma and Jahiruddin, 2004). In this situation, CA practices (minimum tillage, crop residue retention and diverse crop rotations) could be a good option for the improvement of soil quality and crop productivity in Bangladesh. However, CA practices are poorly developed for intensive rice-based cropping system and their effect on SOM, plant nutrients and system productivity have not yet been properly addressed. Hence, the present study was undertaken to monitor the changes in SOM and other plant nutrients with system productivity under CA practices in the rice-jute cropping system in the Low Ganges River Floodplain of Bangladesh

Salinity tolerance of black gram cultivars during germination and early seedling growth

A laboratory experiment regarding germination and seedling growth test was conducted with three black gram genotypes tested under three salinity levels (0, 75 and 150 mM), for 10 days, in sand culture within small plastic pot, to investi-gate the germination and seedling growth characteristics. Different germination traits of all black gram genotypes, like germina-tion percentage (GP), germination rate (GR), coefficient of velocity of germination (CVG) greatly reduced, as well as mean germination time (MGT) increased with increasing salt stress. At high salt stress, BARI Mash-3 provided the highest GP reduction (28.58%), while the lowest was recorded (15.79% to control) in BARI Mash-1. Salinity have the negative impact on shoot and root lengths, fresh and dry weights. The highest (50.32% to con-trol) and lowest reduction (36.39%) of shoot length were recorded in BARI Mash-2 and BARI Mash-1, respectively, under 150 mM NaCl saline conditions. There were signifi-cant reduction of root lengths, root fresh and dry weight, shoot length, shoot fresh and dry weight in all genotypes under saline condition. The genotypes were arranged as BARI Mash-1 > BARI Mash-3 > BARI Mash-2, with respect to salinity tolerance

Secrecy performance of α − κ − µ shadowed fading channel

In this paper, the physical layer security aspects of a wireless framework over α − κ − µ shadowed (AKMS) fading channel are examined by acquiring closed-form novel expressions of average secrecy capacity, secure outage probability (SOP), and strictly positive secrecy capacity. The lower bound of SOP is derived along with the asymptotic expression of SOP at the high signal-to-noise ratio regime in order to achieve secrecy diversity gain. Capitalizing on these expressions, the consequences due to the simultaneous occurrence of fading and shadowing are quantified. Finally, Monte-Carlo simulations are demonstrated to assess the correctness of the expressions

Germination of black gram (VIGNA MUNGO L.) seed is influenced by different storage containers and storage periods

A laboratory test was carried out to examine the influence of various storage containers and periods on the germination percentage of black gram seed. In this research, three seed containers, viz. sealed tin container, poly bag and gunny bag were used to store the seeds, as well as seeds were stored for three different storage periods, viz. 15, 30 and 45 days and thereby conducted germination tests. The results revealed that storage and storage periods considerably influenced the germination percentage (GP) of black gram seed. The highest GP of 87.73% was found in the seeds stored at sealed tin container, while the lowest GP (71.08%) was observed in the seeds stored in gunny bag. Among the three storage containers, the GP reduced rapidly in the seeds stored in gunny bags (6.52%), followed by poly bag (18.98%). The maximum values of GP (85.43%) of black gram seed were recorded when 15 days after storage (DAS), whereas the lowest GP (68.33%) was at 45 DAS, and the GP decreased noticeably with the increase of storage periods from 15 to 30 and to 45 DAS. In combination influence of storage containers and storage periods, the maximum GP (85.90%) was recorded at when seeds kept in sealed tin container with stored for the shortest duration (15 DAS), while the minimum (58.11%) was recorded in the seeds stored in gunny bag for the longest period with 45 DAS. Seeds stored in the sealed tin containers exhibited an excellent performance regarding GP with the shortest storage periods and, thereby, black gram should be kept in sealed tin containers or like this air tight containers for storage, as well as seeds should be sun dried after a short period for maintaining seed quality