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

Problem of access and rights of fishermen to water bodies in haor areas: a case study

Meat to water ratio used for washing was 1:3 for oil sardine and mackerel; but for pink perch and croaker, it was 1:2. Again the washing process was repeated three times for oil sardine and mackerel; but two times for pink perch and croaker. The washed meat was mixed with 2.5% NaC1 and set at +5°C and +40°C for 1, 2 and 3hrs. The gel strength and expressible water content was measured. Basing on this study, setting temperature at +40°C was selected and with respect to time 1hr for sardine and mackerel and 3hrs for pink perch and croaker was selected

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

Transfer Learning with Deep Convolutional Neural Network (CNN) for Pneumonia Detection using Chest X-ray

Pneumonia is a life-threatening disease, which occurs in the lungs caused by either bacterial or viral infection. It can be life-endangering if not acted upon in the right time and thus an early diagnosis of pneumonia is vital. The aim of this paper is to automatically detect bacterial and viral pneumonia using digital x-ray images. It provides a detailed report on advances made in making accurate detection of pneumonia and then presents the methodology adopted by the authors. Four different pre-trained deep Convolutional Neural Network (CNN)- AlexNet, ResNet18, DenseNet201, and SqueezeNet were used for transfer learning. 5247 Bacterial, viral and normal chest x-rays images underwent preprocessing techniques and the modified images were trained for the transfer learning based classification task. In this work, the authors have reported three schemes of classifications: normal vs pneumonia, bacterial vs viral pneumonia and normal, bacterial and viral pneumonia. The classification accuracy of normal and pneumonia images, bacterial and viral pneumonia images, and normal, bacterial and viral pneumonia were 98%, 95%, and 93.3% respectively. This is the highest accuracy in any scheme than the accuracies reported in the literature. Therefore, the proposed study can be useful in faster-diagnosing pneumonia by the radiologist and can help in the fast airport screening of pneumonia patients.Comment: 13 Figures, 5 tables. arXiv admin note: text overlap with arXiv:2003.1314

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

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)

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