Resource-Efficient Technologies最新文献

This work aims the synthesis and characterization of ZnO/SiO₂ nanocatalyst from plant waste material by green route and application of this ZnO/SiO₂ nanocatalyst for the treatment of petroleum refinery effluent. Butea monosperma (Palash) leaves’ powder was used as reducing and stabilizing agent for synthesis of ZnO/SiO₂ nanocatalyst. Palash leaves contain broad variability of biomolecules which work as reducing and capping agent. In this research work, COD and acenaphthylene which is Polycyclic Aromatic Hydrocarbons (PAH) were degraded by synthesizing ZnO/SiO₂ nanocatalyst under UV-light in an annular photocatalytic reactor. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), FIELD emission gun-Scanning electron microscopy (FEG-SEM), Energy dispersive X-ray (EDX) and Transmission electron microscopy (TEM) analysis confirmed the formation of ZnO/SiO₂ nanocatalyst. Characterization studies revealed that spherical and hexagonal nanoparticles with particle size ranging from 8 ± 5 nm to 40 ± 5 nm and mean particle with diameter of 20 ± 5 nm were synthesized using this method which is stable in the environment. Brunauer, Emmett and Teller (BET) surface area of ZnO/SiO₂ nanocatalyst is found to be 150.25 m²/g. Fractional Factorial design was applied to find optimum condition of process parameters and found that optimum percent. Removal of COD (mg/l), and acenaphthylene were achieved at reaction condition of 1 g/L of ZnO/SiO₂ nanocatalyst loading, 30°C temperature and 4 h reaction time and found that optimum percent removal of COD (mg/l), and acenaphthylene is 75%, and 73% respectively. Various metals, naturally present in palash leaves’ powder, decrease band gap of energy and improve photocatalytic activity of nanocatalyst.

More than 80 percent of all electrical energy customers are electric motors. Therefore one of the prospects of resource-effective technologies in power industry is control of rotating electric equipment condition. Winding defects are one of the main causes of electric motor failures. Reliable control of winding condition is an urgent task of modern electrical engineering technology. The present article is devoted to the research of pulsed method application of transformer winding control for electric motor winding condition control. The procedure of winding condition control technology is described. The proposed method is based on the known pulsed method. The essential difference between the two methods is that only one probing impulse is used which is a probing impulse and response signal at once. The results of diagnostic procedure research at different winding defects are given. It is established that the place of winding damage corresponds to characteristic impulse changes. The defect of definite types causes specific changes of the probing impulse form. Therefore, different winding defects could be found with high accuracy along winding.

In South Asia, a number of developing countries like India, Pakistan, Sri Lanka, Bhutan, Nepal, Afghanistan and Maldives are looking into inexhaustible and repeatable alternative energy sources such as solar, wind, hydro and biomass. Geographically, South Asian countries are located in a region of different climatic conditions such as tropical, humid etc. which provides easy access to a variety of renewable energy sources. The governments of South Asian countries have initiated renewable energy policies to encourage industries and individuals to employ renewable energy powered systems in power applications. This article provides an updated and comprehensive overview of the renewable energy status in the South Asian countries, and it includes an assessment of the region's renewable potential, current installed renewable energy capacity. This paper gives a brief description about energy scenario, renewable energy potential and challenges in South Asian countries. The study also provides the renewable energy policies and recommendation in South Asian countries.

The present work addresses the optimization of process parameters for adsorptive removal of α-toluic acid by calcium peroxide (CaO₂) nanoparticles using response surface methodology (RSM). CaO₂ nanoparticles were synthesized by chemical precipitation method and confirmed by Transmission electron microscopy (TEM) and high-resolution TEM (HRTEM) analysis which shows the CaO₂ nanoparticles size range of 5–15 nm. A series of batch adsorption experiments were performed using CaO₂ nanoparticles to remove α-toluic acid from the aqueous solution. Further, an experimental based central composite design (CCD) was developed to study the interactive effect of CaO₂ adsorbent dosage, initial concentration of α-toluic acid, and contact time on α-toluic acid removal efficiency (response) and optimization of the process. Analysis of variance (ANOVA) was performed to determine the significance of the individual and the interactive effects of variables on the response. The model predicted response showed a good agreement with the experimental response, and the coefficient of determination, (R²) was 0.92. Among the variables, the interactive effect of adsorbent dosage and the initial α-toluic acid concentration was found to have more influence on the response than the contact time. Numerical optimization of process by RSM showed the optimal adsorbent dosage, initial concentration of α-toluic acid, and contact time as 0.03 g, 7.06 g/L, and 34 min respectively. The predicted removal efficiency was 99.50%. The experiments performed under these conditions showed α-toluic acid removal efficiency up to 98.05%, which confirmed the adequacy of the model prediction.

The adsorption of Pb²⁺ from aqueous solutions by sorbents based on calcium silicates, obtained in multi-component systems CaCl₂–Na₂SiO₃–H₂O (sorbent I) and CaSO₄·2H₂O–SiO₂·nH₂O–KOH–H₂O (sorbent II), was studied. Surface area of the two sorbents was found to be 100 and 40 m²/g respectively. The sorption capacities of the adsorbent materials were found to be 3.6 l/mmol and 8.4 l/mmol respectively. Characterization of the sorbent materials was carried out. The equilibrium data was fitted in Langmuir's isotherm and the adsorption capacity of the adsorbent materials was determined. The distribution coefficients at Pb²⁺ ions for the sorbents were determined at different ratios of solid and liquid phases.

The present study was conducted to find out the effect of solid state fermentation on release of phenolics and subsequently on improvement of antioxidant activity of fermented seed and flour of Lablab purpureus (seim), using GRAS filamentous fungi i.e. Aspergillus awamori and Aspergillus oryzae. Significant increase in TPC level was observed on 5th day of fermentation of seed and flour with A. awamori and A. oryzae as compared to non-fermented ones. In DPPH and ABTS antioxidant assay, maximum activity was noticed in fermented ethanolic extract of seim seed with A. awamori and A. oryzae on 3rd and 4th day of incubation, respectively. The findings showed higher antioxidant activity formation in fermented seim seed than flour. Significant increase in enzyme activity of α-amylase was also contributed by SSF. This study demonstrated that fermented seed and flour of seim are better source of phytochemicals compared to the non-fermented ones.

In this study, an original and green procedure of processing waste of the citrus fruits was developed using the concept of bio-refinery, innovative techniques “ultrasound” and “micro-wave”, and a green solvent “limonene” to recover carotenoids. Essential oil extraction was performed by Solvent Free Microwave Extraction (SFME) and compared to steam distillation (SD). The essential oil yields were comparable for both processes: 4.02 ± 0.23% for SFME and 4.16 ± 0.05% for SD. After that, carotenoid extraction from citrus peels was performed by ultrasound-assisted extraction (UAE) and conventional extraction (CE) using d-limonene obtained starting from essential oil, as a solvent, and then compared to n-hexane extract. Response surface methodology (RSM) using central composite designs (CCD) approach was launched to investigate the influence of process variables on the ultrasound-assisted extraction (UAE). The statistical analysis revealed that the optimized conditions of ultrasound power, temperature and time were 208 W cm⁻², 20 °C and 5 min giving carotenoid content of 11.25 mg L⁻¹. Compared to the conventional extraction, (UAE) gave an increase of 40% in carotenoid content. The comparison to n-hexane extract gave no significant changes in carotenoid content. Combination of microwave, ultrasound and d-limonene obtained from a bio-refinery of a by-product of citrus fruits industry allow us to develop a very good environmental green approach giving high added values compounds, with a saving of time, and a complete valorisation of waste.

Building-Integrated Photovoltaic (BIPV) is a smart energy production system that incorporates solar PV panels as part of the roof, windows, facades and shading devices. When active heat recovery is combined with BIPV systems either in closed loop (like PV-T with liquid loop) or in an open loop with forced air they are known as building-integrated photovoltaic-thermal (BIPVT systems). This paper reviews the BIPV and BIPVT technology. The paper shows various technologies involved in BIPV and BIPVT as well as their function, cost and aesthetics. In addition a review of the application of BIPV and BIPVT installations is described. In comparison to BIPV systems, BIPVT system has significant benefits and potential for wide use in buildings. The building integrated photovoltaic-thermal system design (BIPVT) is also becoming popular among architects and design engineers.

The paper describes the results of experimental and numerical research of the thickness of the molten bath and the surface erosion of a substance under the influence of compression plasma flows. It has been demonstrated that the formation of the shock-compressed layer affects the melted depth and the mass erosion from the surface of the treated target.