Resource-Efficient Technologies最新文献

The purpose of this study was to expand a trouble free biological method for the synthesis of silver nanoparticles using the fruit extract of Capsicum frutescence (Sweet pepper) to act as reducing and stabilizing agent. Water soluble organics played a vital role for the reduction silver ions into silver nanoparticles. The fruit extract was exposed to silver ions and the resultant biosynthesized silver nanoparticles characterized by UV–Vis spectrophotometry indicated the surface plasmon resonance band at 385–435 nm. X-ray diffraction spectrum showed crystalline structure while scanning electron microscope analyses exposed the monodispersed distribution and particle size of 20–25 nm. The elemental analysis displayed strong signal at 3 keV that agrees to silver ions and confirms the presence of metallic silver. The antibacterial activity of silver nanoparticles was determined by agar well diffusion method against gram positive and gram negative bacteria. Maximum and minimum zones of inhibition were renowned against Escherichia coli (11.5 mm) and Bacillus subtilis (10.5 mm), respectively. This study exposed that silver nanoparticles retained good bactericidal activity at 80 µg/ml concentration.

Phytic acid (PA), a molecule with high commercial value, is one of the important component in peanut meal. However, PA has not yet been isolated from peanut meal and played its role. This paper reported the extraction conditions of PA from peanut meal after removed protein. The independent variables were hydrochloric acid (HCl) concentration, solid to liquid ratio, extraction time and extraction temperature. Response surface methodology (RSM) was used to optimize the extraction conditions based on the extraction yield of PA. The results show that the second-order polynomial models derived from responses well with the experimental (R² = 0.9783). The optimal extraction condition was obtained with solid to liquid ratio of 1:16 (g:mL), HCl concentration of 0.02 mol/L, extraction time of 105 min, and extraction temperature of 30°C. At this condition, PA with higher purity were obtained. the extraction ratio was 6.12%, and the content of PA was 182.7 mg/g dry PA extract. The experimental values under optimal condition were in good consistent with the predicted values. The PA extracted from peanut meal was verified qualitatively by IR spectra. The extraction technology of PA from peanut meal has a strong potential for realized high-value utilization of peanut meal.

Novel hybrid exchanger poly-o-toluidine zirconium(IV) phosphotellurite was synthesized and physico-chemical properties of the material were well studied by FTIR, XRD, TGA, SEM-EDX and TEM analysis. The composite exchanger showed good ion exchange capacity and excellent removal potential towards US Environmental Protection Agency listed priority pollutants like chlorobenzene and 1,4-dichlorobenzene. The factors affecting the adsorption like time, pH and temperature were studied in detail using UV spectrophotometry. More than 90% of the pollutants were successfully removed using the exchanger. The composite also showed selectivity towards heavy metal ions, especially mercury ions. The sorption kinetics of the material was studied in detail using pseudo first order and pseudo second order kinetics. The material followed pseudo second order kinetic model indicating chemisorption of the pollutants. The composite can be successfully used for environmental remediation purposes.

The atmospheric concentration of carbon dioxide (CO₂) has been increasing and it remained above 400 ppm throughout the year 2016 for the first time. The aviation industry is a main contributor towards green house gas emission. In this regard, aviation industry as a whole and airports in particular are trying to limit their carbon foot print. A feasible solution is to substitute the conventional electricity energy consumption of airport with clean energy sources. Solar PV route is considered as non polluting source of electricity but MW scale plant requires more land area. Since vast areas are mandatory in airport as buffer zones, this land can be effectively used for utility scale solar PV plant. A 2 MWp onsite solar PV power plant is proposed for Raj Bhoj International Airport (RBIA), India. An online PV simulation tool SISIFO, developed by Universidad Politécnica de Madrid (UPM), has been used to analyse the performance of the proposed plant. The PV module rating, inverter and transformer specifications etc. are provided as per manufacturer's datasheet. The plant is capable of generating 2733.122 MWh of electrical energy annually. The monthly averaged energy yield and performance ratio (PR) are 113.88 kWh/kWp and 85.54% respectively, which are best when compared to similar utility scale PV power plants. The economic and environmental benefits of the proposed plant are also discussed. The PV plant generation capacity can surpass the daily electrical energy consumption of airport. This paves way for RBIA to become second airport in the world to be energy self sufficient through solar power.

The ambient temperature carbon monoxide oxidation is one of the important topics in the present scenario. In this paper, we prepared various types of catalysts from the precursors of cobalt nitrate, cerium nitrate, copper nitrate and manganese nitrate for the oxidation of CO. Among the prepared catalysts, the cerium nitrate precursor showed the best performance for CO oxidation at low temperature. The activity of the catalysts was measured in different calcination conditions like stagnant air, flowing air and reactive calcination (4.5% CO in air). The activity test was done in the reactor under the following reaction conditions: 100 mg of catalyst, 2.5% CO in the air and the reaction temperature was increased from ambient to a higher value at which complete oxidation of CO was achieved. The characterization of the catalyst was done by several techniques like XRD, FTIR, SEM-EDX, XPS and BET. The order of activity for different catalysts was as follows: Ce-Oxide > Mn-Oxide > Cu-Oxide > Co-Oxide.

Silver nanoparticles of 15–20 nm size with spherical shape were synthesized from green synthesis method using Datura stramonium leaf extract. Synthesized Ag NPs were studied for their optical, structural, surface morphological and antibacterial properties. The optical study shows that the appearance of SPR peak at 444 nm in the absorption spectrum is affirming the formation of Ag NPs and its high intensity with narrowed width indicating the homogenous size and shape of the Ag NPs. Structural studies reveal the good crystalline nature of face center cubic structure of Ag crystal and preferentially oriented along (111) plane with average crystallite size of 18 nm. FTIR analysis exhibits the possible reducing bio-molecules within the leaf extract. The well defined homogenous spherical shape of the Ag NPs is clearly observed from the TEM studies and lattice fringes spacing of 0.23 nm shows the high crystalline nature of the synthesized Ag NPs. EDAX profile affirms the Ag crystal by the presence of energy peak at 3 eV. The synthesized Ag NPs showed antibacterial activity against E. coli and S. aureus bacteria. However, well pronounced activity was observed against E. coli.

Concerns about the ever increasing quantities of glycerol produced as a by-product of the process of manufacture of bio-diesel serve as a fuel for research about the alternative uses of glycerol. The esterification of glycerol with acetic acid over Cesium supported heteropolyacid (CsPWA) serving as the catalyst was carried out. The products obtained were mono, di and tri acetins which have wide application as biofuels. A series of experiments were carried out with CsPWA as catalyst and parameters considered for studies were temperature, molar ratio of reactants (acetic acid:glycerol) and the catalyst loading weight percent. Each parameter was varied keeping the other two constant and the results were recorded. Temperature was varied from 80°C to 110°C; molar ratio of glycerol to acetic acid is between 3:1 and 9:1 and catalyst loading of 3%w/w to 7%w/w. The yield and conversion varied for different conditions, but in general, the yield of diacetin and triacetin increased with time. Optimum parameters were adjudged to be 110°C with a molar ratio of 9:1 of the reactants and catalyst loading being 5% weight of reaction mixture where maximum glycerol conversion of 98% was obtained. The results obtained indicate that the esterification of glycerol with acetic acid is a consecutive reaction and the kinetic model was developed based on homogeneous first order reaction series by optimization method using MATLAB, and rate constants (k₁, k₂ and k₃) were determined. From the rate constants at different temperatures, using Arrhenius equation the activation energies (E₁, E₂ and E₃) were also determined.

In this study, for the first time the activated carbon has been produced from medlar seed (Mespilus germanica) via chemical activation with KOH. The carbonization process was carried out at different temperatures of 450, 550, 650 and 750°C. The Nitrogen adsorption-desorption, Fourier transform infrared spectroscopy (FTIR) and Field Emission Scanning Electron Microscope (FESEM) analyses were carried out on the adsorbents. The effect of operating parameters, such as pH, initial concentration of Cr(VI), adsorbent dosage and contact time were investigated. The experimental data showed better agreement with the Langmuir model and the maximum adsorption capacity was evaluated to be 200 mg/g. Kinetic studies indicated that the adsorption process follows the pseudo second-order model and the chemical reaction is the rate-limiting step. Thermodynamic parameters showed that the adsorption process could be considered a spontaneous (ΔG < 0), endothermic (ΔH > 0) process which leads to an increase in entropy (ΔS > 0). The application of support vector machine combined with genetic algorithm (SVM-GA) and artificial neural network (ANN) was investigated to predict the percentage of chromium removal from aqueous solution using synthesized activated carbon. The comparison of correlation coefficient (R²) related to ANN and the SVR-GA models with experimental data proved that both models were able to predict the percentage of chromium removal, by synthetic activated carbon while the SVR-GA model prediction was more accurate.

Energy has been recognized as one of the key inputs for the economic growth and social development of a country. India being one of the largest and rapidly growing developing countries, there is an impending energy crisis which requires immediate measures to be adopted. In this situation the concept of Energy Intensity comes under special focus to ensure energy security in an environmentally sustainable way. Energy Intensity of Indian manufacturing industries is among the highest in the world and stands for enormous energy consumption. Hence, reducing the Energy Intensity of Indian manufacturing industries is one of the challenges. This study attempts to analyse the factors which influence the Energy Intensity of Indian manufacturing industries and how they can be improved to reduce the Energy Intensity. The paper considers five of the largest energy consuming manufacturing industrial sectors in India viz. Aluminium, Cement, Iron & Steel Industries, Textile Industries and Fertilizer Industries and conducts a detailed Energy Intensity analysis using the data from PROWESS database of the Centre for Monitoring Indian Economy (CMIE) for the period 2005–2014.

Cereal and legumes meet a considerable requirement of protein and carbohydrate of the local population. Most of the foods are cereal based but some cereal/legume or legume based foods are also common in many countries of Asia and Africa. In present study, the effect of fermentation on total phenolics, antioxidant activity and α-amylase enzyme activity of ethanolic extracts of each of seeds and flours combination (1:1) of Oryza sativa (rice) and Lablab purpureus (seim) was determined. The percentage inhibition of free radicals formation by DPPH and ABTS assays was found maximum i.e. 80.66 ± 0.21, 97.67 ± 0.35 on 4th day of incubation of combined sample of rice and seim seeds fermented with Aspergillus oryzae and Aspergillus awamori, respectively. The increased percentage inhibition of free radical formation of fermented samples was found greater than the non-fermented samples (65.88 ± 0.15, 42.00 ± 0.63). The TPC of substrate i.e. rice:seim seeds (1:1) was also found maximum i.e. 47.53 ± 0.20 on 5th day of fermentation with A. awamori. α-amylase activity of fermented samples was also found higher than that of non fermented samples. Almost similar results were obtained in combined flour extract of both the substrates. Increase in level of α-amylase enzyme during SSF indicates that enzymes produced by microorganisms were responsible for release of bound phenolics which may be responsible for increase in antoxidant activity of extracts of fermented seeds and flour combination a cereal and a legume.