Multiple distributed generators for distribution feeder voltage support

Inclusion of voltage support distributed generation (VSDG) can reinforce the feeder voltage of distribution networks, especially in rural/remote areas where voltage dip and frequent blackouts are significant concerns for power utilities. However, installation of multiple distributed generators within a distribution grid system may introduce technical problems in network operation and control, including control interaction and/or voltage instability. This paper addresses the network issues that may occur during multiple VSDG inclusion in the network and presents analytical models and solutions to develop design criteria of VSDG installation in the networks. Voltage sensitivity of lines is investigated and the effect of DG real (P) and reactive (Q) power injections with Q priority is developed for optimal use of VSDG in correcting the network voltage. Interaction among VSDG controllers has been explored and a generalized model is presented to analyze this interaction between any number of VSDGs in the network. The model is tested on a sample VSDG system and test results are presented. The issue of which VSDG must be started recognizing the costs of starting is addressed using an inverse definite minimum time (IDMT) model. A prioritization and coordination scheme for start discrimination of multiple VSDGs is proposed which avoids hunting between multiple generators

Optimum planting date for the maximum tuber yield of tropical sugar beet (Beta vulgaris L.) genotypes in the Old Brahmaputra Floodplain

Planting dates for a crop is a non-monetary input but plays a significant role in increasing the yield crop. Therefore, identifying genotype-specific planting dates is essential for obtaining the economic yield of tropical sugar beet. From this perspective, a field experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University in  Bangladesh, from November 2015 to April 2016. Five sugar beet genotypes: Shubhra, Cauvery, EB-0616, EB-0626, and EB-0809 planted on four dates: 10, 20, 30 November, and 10 December. Treatments were laid out in a split-plot design replicated three times. Data revealed that planting on 10 November date, genotype EB-0809 produced the highest tuber yield, which was significantly superior to any other genotype combined with other planting dates. It was found that every ten days delay of planting from 10 November to 30 December reduced the tuber yield by 30, 43, and 55%, respectively. Results confirmed that planting the EB-0809 genotype on 10 November is ideal to obtain the highest tuber yield of tropical sugar beet in Bangladesh

EFFECTS OF LAND-USE CHANGE ON THE PROPERTIES OF TOP SOIL OF DECIDUOUS SAL FOREST IN BANGLADESH

This study examined the effects of land use change on the physico-chemical properties of top soil in the deciduous Sal forest of Bangladesh. Relatively less disturbed Sal (Shorea robusta Roxb. Ex Gaertn.) forest stands and the nearby stands those were converted into Acacia (Acacia auriculiformis Benth.) plantation and pineapple (Ananus comosus (L.) Merr.) cultivation were selected to examine the effects of land use change on soil properties. For each land use type, soil samples were collected from 4 locations, 50m distant from each other, as replicates. Soil samples were collected at 0-5, 5-10, and 10-15 cm depths. Soil moisture content, conductivity, pH organic C, total N and total P were determined as soil properties. Leaf litter of Sal, Acacia and pineapple was incubation for 90 and 180 days in independent identical soil in order to examine the effects of plant species through leaf litter on the soil chemical nutrient (N and P) status. Data showed that soil moisture content, conductivity and pH were significantly affected by land use but not by depth. However, soil organic C was affected by both land-use type (P< 0.02) and soil depth (P< 0.003), although no significant interactions appeared between these two factors. Soil total N and P did not differ between land use types but by depth and, N and P contents decreased with the increase of depth. Rates of nutrients (N and P) released from Sal, Acacia and pineapple did not differ significantly among them during incubation. Results of the present study reveal that properties of the top soil of the Madhupur Sal forest are different in their responses to the varying land uses. The findings of this study are thus relevant for the sustainable management of the deciduous Sal forest ecosystems

Effect of fertilizer management on growth and yield of fragrant fine rice varieties in rainfed condition

A field experiment was carried out at the Banglasesh Institute of Nuclear Agriculture (BINA) farm, Mymensingh during July to December 2010, to find out optimum variety and optimum fertility management of aromatic fine rice grown in transplant rainfed condition. The experiment was laid out in split-plot design with three replications assigning the variety in the main plot and different fertilizer management in the sub-plot. Results indicated that the effect of aromatic fine rice varieties and fertilizer management showed significant variation in respect of yield contributing characters and yield. At harvest, maximum number of effective tillers/hill (12.7 and 12.5), number of grains/panicle (105.6 and 115.2), 1000 grain weight (13.25 and 19.97 g), grain yield (3.29 and 3.30 t/ha) and straw yield (5.0 and 5.7 t/ha) were obtained from the application of T6 (NPKSZn; RD BARC, 2005) @ 126.9, 19.81, 65, 43.3 and 1.8 kg/ha+Cow dung at 5.0 t/ha) and T9 (Urea super granules (USG) @ 1 (1.8 g) granules/spot) + PKSZn; (RD BARC, 2005 @19.81, 65, 43.3 and 1.8 kg/ha). The fertilizer management T6 (NPKSZn; RD BARC, 2005) @ 126.9, 19.81, 65, 43.3 and 1.8 kg/ha+Cow dung at 5.0 t/ha) and T9 (Urea super granules (USG) @ 1 (1.8 g) granules/spot)+PKSZn; (RD BARC,2005 @ 19.81, 65, 43.3 and 1.8 kg/ha) produced the highest grain yield of Ukunimadhu (2.95 t/ha) and Kataribhog (3.96 t/ha)

Marriage and marriage dissolution in a rural area of Bangladesh

The aim of this thesis is to study the age and sex patterns and differentials of marriage formation and marriage dissolution in rural Bangladesh, using a unique set of marital status registration data from the Demographic Surveillance System (DSS) of the International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B) for the years 1975-1979. This study is the first of its kind in Bangladesh to use marital status registration data. In rural Bangladesh marriage is universal and early, especially for females. It appears from this study that female age at first marriage has been increasing somewhat during the past 5 years but for males age at marriage remains almost constant. A pronounced seasonality of marriages prevails in the rural areas of Bangladesh. As in other societies, education has a substantial effect on age at marriage of both males and females. Groom's occupation has only a slight effect on age at marriage. Divorce in rural Bangladesh is frequentand largely occurs early in marriage. Age difference between groom and bride at marriage has a strong impact on the incidence of widowhood. It also has a marked effect on divorce. Education, husband's occupation and religion have a differential influence on the stability of marriage and on remarriage after divorce or widowhood

Synthesis of hydantoin and thiohydantoin related compounds from benzil and study of their cytotoxicity

Condensation of benzil (1) with urea, monophenyl urea and diphenyl urea in the presence of absolute ethanol using 30% aqueous NaOH gave the products 1a, 1b and 1c respectively and also with thiourea, monomethyl thiourea, dimethyl thiourea and diethyl thiourea the products 2a, 2b, 2c and 2d were obtained. Methylation of the product, 2a in the presence of dimethyl formamide (DMF) using K2CO3 formed 2. The compounds 1b, 1c, 2b, 2c and 2 showed highly cytotoxic activity and the compounds 1a, 2a, 2d showed relatively low cytotoxic activity against brine shrimp lethality bioassay

Uncertainty management in multiobjective hydro-thermal self-scheduling under emission considerations

In this paper, a stochastic multiobjective framework is proposed for a day-ahead short-term Hydro Thermal Self-Scheduling (HTSS) problem for joint energy and reserve markets. An efficient linear formulations are introduced in this paper to deal with the nonlinearity of original problem due to the dynamic ramp rate limits, prohibited operating zones, operating services of thermal plants, multi-head power discharge characteristics of hydro generating units and spillage of reservoirs. Besides, system uncertainties including the generating units\u27 contingencies and price uncertainty are explicitly considered in the stochastic market clearing scheme. For the stochastic modeling of probable multiobjective optimization scenarios, a lattice Monte Carlo simulation has been adopted to have a better coverage of the system uncertainty spectrum. Consequently, the resulting multiobjective optimization scenarios should concurrently optimize competing objective functions including GENeration COmpany\u27s (GENCO\u27s) profit maximization and thermal units\u27 emission minimization. Accordingly, the ε-constraint method is used to solve the multiobjective optimization problem and generate the Pareto set. Then, a fuzzy satisfying method is employed to choose the most preferred solution among all Pareto optimal solutions. The performance of the presented method is verified in different case studies. The results obtained from ε-constraint method is compared with those reported by weighted sum method, evolutionary programming-based interactive Fuzzy satisfying method, differential evolution, quantum-behaved particle swarm optimization and hybrid multi-objective cultural algorithm, verifying the superiority of the proposed approach

Optimizing of planting density on the growth and yield of aromatic fine rice in rainfed condition

A field experiment was carried out at the Bangladesh Institute of Nuclear Agriculture (BINA) farm, Mymensingh, Bangladesh during July to December, 2010, in view to find out the optimum plant spacing for the highest yield of aromatic fine rice grown in rain fed season. The experiment was carried out with four aromatic fine rice (V1= BRRI dhan34, V2= Ukunimadhu, V3= Basmati and V4= Kataribhog) and four different plant spacings (S1= 15cm×15cm, S2= 20cm × 15cm, S3= 20cm × 20cm, S4= 20cm × 25cm). The experiment was laid out in split-plot design with three replications assigning variety in the main plot and the spacing in the sub plot. It was observed that almost all the plant characters and yield were significantly affected by the aromatic fine rice and plant spacing. Among the spacings tested against the four varieties, the highest grain yield was obtained at 20 cm × 15 cm and 20 cm × 20 cm spacing. The spacing 20 cm×15 cm and 20 cm × 20 cm were proven more appropriate because it produced more number of effective tillers hill-1 more number of grains panicle-1 and ultimately produced the higher grain yield than other two spacings. Among the varieties Kataribhog, Basmati and Ukunimadhu produced higher grain yield at 20 cm × 15 cm and 20 cm × 20 cm