This study proposes a polynomial regression model with Ridge regularization for forecasting the combined renewable energy generation (solar and wind) in Dhaka City. The model was developed using over a decade of meteorological data (2014–2023), capturing non-linear interactions among key predictors such as temperature, wind speed, and solar irradiance. Data preprocessing included normalization and outlier handling. Model performance was evaluated using standard metrics—mean squared error (MSE), mean absolute error (MAE), root mean square error (RMSE), and coefficient of determination (R²)—with 80/20 train-test splitting and 05-fold cross-validation ensuring generalizability. The Ridge-regularized model achieved an R² of 0.99 on the test data, with very low normalized error values (MSE ≈ 2.42 × 10⁻⁸, MAE ≈ 7.59 × 10⁻⁵), corresponding to an RMSE of approximately 1.55 × 10⁻⁴. While these error values are small due to normalization, the R² score provides a robust, scale-independent measure of performance. The high accuracy is supported by the strong correlations among features and the model’s ability to generalize effectively across cross-validation folds. By integrating wind and solar forecasting under a unified framework and applying Ridge regularization to manage multicollinearity, this work offers a reliable and interpretable approach for renewable energy planning in rapidly urbanizing regions.

In South Asia, agriculture heavily relies on groundwater for irrigation. The withdrawal is nearly 250 km3 annually. Approximately, 12 million electric and 10 million diesel water extraction pumps, totaling about 22 million, are in use in this area. In contrast, while PV-powered solar irrigation pumps are becoming more popular, they take up agricultural land, increasing the competition for land resources between food and clean energy production. It is left unattended during the off-season, wasting a lot of potential solar power that could produce green electricity. To address this, an integrated farming model can be established, utilizing existing solar pump facilities for crop cultivation, rearing Black Bengal Goats, and native fish farming. This diversified approach combines sustainable energy solutions with solar irrigation, generating both agricultural products and electricity while maintaining agricultural land for cultivation and promotion of clean energy production. The proposed method has produced both agricultural products and electricity simultaneously. This integrated system offers a solution to the challenges faced in the region, balancing food production and clean energy goals effectively. Bangladesh J. Sci. Ind. Res. 58(3), 163-172, 2023

In the present study, we described the organic dye extraction process from local flowers employing different methods and solvents (a mixture of acetic acid and ethanol, another is only acetic acid); especially we completed our research by exploring dye from red gerbera flower as it showed higher absorbance. Both dry and fresh petals of the flower were used for extracting dyes. The results revealed that the mixture-based dye extraction from dry red gerbera yielded a higher absorbance value of 4.579 a.u., whereas the acetic acid-based extraction from the same source exhibited a lower absorbance value of 2.778 a.u. The choice of solvent for dye extraction was found to significantly influence the absorption spectrum. Additionally, the Beer-Lambert law was employed to analyze the relationship between the absorbance and the concentration of the extracted dyes. For the electrode, a TiO₂ film was created using the spin coating technique. From the XRD graph, we found the band gap energy of TiO₂ which is 2.81eV (annealed at 450°C), the type of nanoparticle of the thin film. Also found a Crystallite size of 32.95nm and a specific Surface Area (SSA) of 43.048 m².g⁻¹, Microstrain (ε) of 5e-3 and Dislocation Density (δ) of 9.2e-4cm⁻².

Biomass can be converted into either heat energy or electrical or energy carriers using both thermo-chemical and bio-chemical conversion. Briquetting is a process where untreated biomass is converted into homogeneous, uniformly sized high density solid blocks. Briquettes are used in boilers, heating plants, thermal power stations and by individual households for heating. Present study focuses on using poultry manure with rice husk and saw dust. Poultry manure mixed with rice husk or saw dust by 60:40 ratio provides comparatively higher bond strength. Calorific value varies significantly with the use of poultry manure and tree leaves as well as its production cost. Pure rice husk contains higher calorific value (HCV) 12.6 MJ/Kg where adding poultry manure reduces its value to 10.3 MJ/Kg and Saw dust shows 10.4 MJ/Kg where pure saw dust has 16.3 MJ/Kg in 60:40 ratios with poultry manure. Addition of 20% tree leaves on weight basis ratio of 40:40:20 with base materials and poultry manure shows 10.5 MJ/Kg and 11.7 MJ/Kg respectively for rice husk and saw dust. Competitive price of briquette for 60:40 ratios with Poultry Manure shows 6 BDT/Kg and 5BDT/Kg when secondary material is added. Moreover, if the machine capacity increases the price is reduced. Dhaka Univ. J. Sci. 71(2): 95-103, 2023 (July)