Browsing by Author "ISLAM, MOHAMMAD DIDARUL"

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    EFFECT OF NEEM OIL AND NEEM LEAF EXTRACT ON MORTALITY, GROWTH AND FEEDING RESPONSES OF JUTE HAIRY CATERPILLAR, Spilarctia obliqua (Walker)
    (Department of Entomology, Sher-e-Bangla Agricultural University, Dhaka-1207, 2006-06) ISLAM, MOHAMMAD DIDARUL
    Experiments were conducted in the I)ivision of Entomology. Bangladesh Jute Research Institute, Manik Mia Avenue. Dhaka. to study the clTbct of Neem oil and Neem leaf extract on mortality, growth and feeding responses ofjute haiiy caterpillar. Spilarctia obliqua (Walker). To evaluate the efficacy or neem products on the larval mortal fly. third. Iourth and ti (lii instar larvae were allowed to feed on jute leaves treated with neem extract (1:20) and nccm oil at 0.5. 1.0. 2.5 and 5.0% emulsified with 0.1% Nikalin and their modality were recorded at different days after treatment. Maximum percent larval mortality occurred at the higher two concentratiOns (2.5 and 5.0%) in each instar. Neem lealextract (1:20) and lower concentratIons (0.5 and 1.0%) of neeni oil. signiticantly increased the larval mortality. flue median lethal dose (11)50) values of neem oil for different larval instars at above concentration were also determined. The effect of neem oil on growth and feeding respohises were evaluated by exposing fourth instar larvae to lOad treated with riccni oil at 0.5% concentration either for 48 hours (48 hrs treatment) or continuously throughout the larval period (continuous trcatment).Neeni oil exhibited growth inhibiting etiCets on the developing larvae and reduced the food consumption as compared to control. Ilie effects were more pronounced in continuous treatment. Such efiCets on development were prolongation of larval period. reduction in the larval size, blackish spots on the larval body. hairless larvae and development of abnonnal pupae. Adults developed from treated larvae were malformed or had crippled wings. Neem served as a potential growth inhibitor and feeding deterrent against S. ohl:qua and it can be integrated with appropriate cultural and biological pest control tactics.
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    EFFECT OF SOILING ON SOLAR PANELS: IN-FIELD OUTPUT CHARACTERIZATION FOR CLEANING-CYCLE AND ECONOMIC ANALYSIS
    (Department of Electrical, Electronic and Communication Engineering, MIST, 2023-04) ISLAM, MOHAMMAD DIDARUL
    Photovoltaics (PV) system is a prominent renewable energy technology that converts sunlight into electricity. This study investigates the impact of uniform and non-uniform soiling on the performance of photovoltaic (PV) panels. Soiling refers to the accumulation of dust on the surface of solar panels. This reduces the amount of sunlight reaching the solar cells and thus decreases the energy output. Uniform soiling occurs when the dust is evenly distributed on the surface, while non-uniform soiling occurs when the dust is unevenly distributed. In this thesis, we have conducted experiments and analyses using two types of mainstream PV technology (namely, monofacial and bifacial panels) to evaluate the respective effects of soiling. For uniform soiling conditions, we analyze the (i) tiltdependent soiling rate and (ii) the techno-economic analysis under the soiling-cleaning cycle. Firstly, we developed an empirical soiling rate model that helped us to estimate the tilt-dependent soiling rate of that particular location. This implies the soiling rate at an arbitrary tilt can be estimated if we know the soiling rate of only one tilt angle PV panel. Secondly, we analyzed the energy output revenue of various tilt angle PV panels under uniform soiling conditions. From this analysis result, we were able to determine the optimum cleaning cycle for each tilt angle. We also conducted a techno-economic analysis based on the optimum cleaning cycle condition. Finally, at the optimum cleaning cycle, a PV panel can generate the maximum revenue. Therefore, the PV power plant should adhere to the optimum cleaning cycle to maximize its revenue. The PV power plant should follow the optimum cleaning cycle procedure to maximize its revenue. The study finds that the soiling rate is inversely proportional to the tilt angle, meaning that higher tilt angles have lower soiling rates or vice-versa. The study shows that a 30° tilt angle PV panel has maximum revenue and energy generation in Dhaka. The optimum cleaning cycle ranges from 4 to 6 days depending on the tilt angle. Furthermore, non-uniform soiling conditions and partial shading have been analyzed through our designed I-V scanner. This study aims to understand the effect of partial shading and non-uniform soiling on PV panels by conducting various controlled experiments. The experiments show that non-uniform soiling, such as bird droppings, significantly affects the PV panel output and can cause a drastic reduction in energy production. Therefore, immediate cleaning intervention is necessary to mitigate the effect of non-uniform soiling on PV panels. The study in this thesis is important for PV power plants to maximize their revenue by balancing the revenue and the net cleaning cost. The study enhances the understanding of soiling physics and its effect on the solar panel tilt angle for the South Asian region. The study also provides insights into the effect of uniform and non-uniform soiling on the solar panel energy output using infield characterization.