This paper examines the torque ripple and cogging torque variation in surface mounted permanent magnet synchronous motors with skewed rotor. The effect of slot/pole combinations and magnet shapes on the magnitude and harmonic content of torque waveforms in a PMSM drive has been studied. Finite element analysis (FEA) and experimental results show that for certain magnet designs and configurations the skewing with steps does not necessarily reduce the ripple in the electromagnetic torque, but may cause it to increase. The electromagnetic torque waveforms including cogging torque have been analyzed for four different PMSM configurations having the same envelop dimensions and output characteristics.

A study was conducted to estimate heterosis of 21 tomato cross combinations involving seven parents at the experimental field of Olericulture Division of HRC, BARI during the winter season of [2005][2006]. Analysis of variance indicated highly significant differences for all the characters suggesting the presence of genetic variability among the studied materials. Three combinations (P2 × P3, P3 × P4, P3 × P5) showed significant early flowering, while two P1 × P7 (16.67%) and P1 × P2 (12.44%) for individual fruit weight. In the study, the cross combinations P4 × P7 (62.31%), P2 × P6 (37.44%), P4 × P6 (34.77%), P2 × P7 (33.67%), P3 × P7 (32.09%), and P3 × P4 (29.82%) manifested higher heterosis over better parent for yield per plant.

A field experiment on French bean taking the variety BARI Jhar Shim-2 was conducted with five levels of Nitrogen (0, 40, 80, ) and four levels of each of phosphorous (0, 40, 80 and 120

Twenty pumpkin (Cucurbita moschata) genotypes were characterized for morphological and yield attributes in northern area of Bangladesh during kharif season of 2006. The range of first flowering was at 52.0-73.7 days. The early flowering and early maturity was observed in BD-227 genotype. The range of variability was distinct for vine length at harvest, leaf length, leaf diameter, number of branches per plant. The vine length was maximum (400cm) in BD-242 and minimum (169cm) in BD-255. Leaf length ranged from 30.6-47.2 cm in different genotypes and the number of branches per plant varied from 2.0-4.7. The number of branches per plant was maximum (4.7) in BD-270. Entry BD-268 produced maximum number of fruits (15.7) per plant and the minimum (2.0) was in BD-251. The maximum average fruit weight (4.2kg) was in BD-250 and minimum (1.5kg) in BD-257. There was significant variation with regards to yield of different pumpkin genotypes, which was varied from 5.9-36.0 kg. Among the twenty one pumpkin germplasm, the maximum fruit yield (36.1kg/plant) was recorded in BD-243 genotype which was closely related to BD-234 genotype (31.1kg/plant) and minimum (5.9kg/plant) was in BD-270. The qualitative characteristics of these pumpkin genotypes showed also variation in fruit colour and flesh colour. The over all performance among the genotypes, BD-243, BD-268, BD-242, BD-234, BD-288, BD-250 and BD-227 may be utilized in breeding program.

Textile industries release huge amount of effluents to aquatic systems, which contain toxic and hazardous pollutants degrading the environment. A laboratory scale study was conducted to characterize physicochemical parameters of local textile industrial effluents and evaluate their impact on aquatic macrophytes and algae. Total suspended solids (TSS) and total dissolved solid (TDS) was found 100 to 336 mg/L and 1856 to 4356 mg/L, respectively. The recorded pH was 9.6 to 11.2 and temperature 40.5 to 43°C. Dissolved oxygen (DO), biological oxygen demand (BOD) and chemical oxygen demand (COD) was recorded 0.11 to 0.5, 151.24 to 299.1 and 652.8 to 2304 mg/L, respectively. Electrical conductivity (EC) was monitored 2210 to 6020 μs/cm; salinity was found 1.1 to 3.3 ‰, and color 1890.75 to 5625 PCU. Zinc (Zn), cadmium (Cd), copper (Cu) were 0.0838 to 0.596, 0.0 to 0.0006, 0.018 to 0.1727 ppm, respectively. Except heavy metals concentrations all of the physicochemical parameters were found beyond the standard limit set by department of Environment (DoE). Textile industrial effluents showed the toxic effects on aquatic macrophytes and algae, as aquatic macrophytes could hardly survive 2 days on textile effluents and noticeable reduction of algal concentration was found when grown on textile effluents. Key words: Textile effluents; Toxic effects; Physicochemical parameter; Aquatic macrophytes; Algae DOI: 10.3329/bjsir.v45i1.5187 Bangladesh J. Sci. Ind. Res. 45(1), 79-84, 2010