Resource-Efficient Technologies最新文献

Siderophores are small molecules that can easily bind to ferric iron. As a chelating agent, they transport iron molecules inside the bacterial cell for various biochemical reactions. Due to its various applications in medicinal, industrial and environmental related aspects, this paper deals with characterization and optimization of few siderophores producing bacteria from the soil samples, collected from Chikkamagaluru district, Karnataka. The siderophores production was assayed qualitatively and quantitatively through Chrome Azurol S and the results showed positive for the strains VITVK5 and VITVK6 that grown in succinate medium. Further characterization and optimization results revealed that both the bacterium has the ability to yield siderophores (∼60–80% units) in the optimum condition of pH 8, at 37°C with glucose and sucrose as a carbon source and NaNO3 as a nitrogen source. Thus, the study concludes that strains VITVK5 and VITVK6 can be promising candidates for the siderophores production which can play major applications in medicinal and industrial aspects.

The vapour recompression scheme (VRC) has been very effective in continuous distillation for energy intensification. The applicability of this scheme for the separation of multicomponent wide boiling constituents in batch distillation is a major challenge, because of the unsteady nature of the batch. In this study, the vapour recompression scheme has been implemented for the separation of multicomponent wide boiling constituents in the batch distillation. For the optimal usage of energy from compressed vapours manipulation of top tray vapour or external energy is done. A comparative study of the vapour recompressed batch distillation having a variable speed single compressor (SVRBD) and double stage compressor (DVRBD) with conventional batch distillation in terms of energy savings and total annualized cost is done. The VRC schemes achieve an energy savings of 50% and 10.03% total annualized cost (TAC) for SVRBD and DVRBD achieve 52% energy savings and 12.21% TAC with a payback period of 10 years.

The nano-sized particles make an imprint on us in our daily lives and it has great importance in the numerous fields of biotechnology like the food industry, medical and industrial field. Gold nanoparticles are one of the widely used particles as it has many therapeutic applications, such as drug delivery system for many diseases like cancer, cardiovascular diseases, diabetes mellitus etc. biosensors, and environmental applications of dye degradation, bioremediation of toxic chemicals present in the environment (soil and atmosphere). Gold nanoparticles synthesis by the green route has become the latest development, because of the bioavailability of sources like plants or microorganisms, and it also reduces the utilization of toxic chemicals. This review explains the various microorganisms like bacteria, algae, fungi, actinomycetes and yeast involved in the synthesis of these nanoparticles also elucidate the size, shape and functional groups involved in the synthesis of nanoparticles and its applications.

The work presents real-time data acquisition and monitoring of solar photovoltaic modules using LabVIEW. A graphical program has been developed to obtain efficiency and fill factor of solar PV module. A front panel is designed, displaying all the acquired data such as; voltage, current, solar radiation, ambient temperature, humidity, Current vs. Voltage and Power vs. Voltage graphs which make it very useful to understand the performance behavior of the solar photovoltaic module in real time. Data acquisition and monitoring for solar panels of different ratings are carried out. This tool is an effective platform for experimental study in the laboratory of different solar photovoltaic modules with access to real-time data.

The main objective of this study is to analyze the drying behavior of cashew nut experimentally in a solar biomass hybrid dryer using mathematical models. Suitability of fifteen different mathematical drying models available in the literature is used to describe the drying characteristics of cashew. Experimental data of moisture ratio, temperature and relative humidity obtained from different dryer conditions were fitted to the various empirical drying models. The performance of the drying model was compared based on their correlation co-efficient (R²), Root Mean Square Error (RMSE) and Reduced Chi-Square (χ²) between the observed moisture ratios. The two terms and Midilli models showed the best fit under solar drying. Page model was found to be the best model for describing the thin layer drying behavior of cashew for biomass drying and hybrid drying.

The present study aims at finding out the optimum parameters for the extraction of components from Betel leaves possessing medicinal applications using ethanol solvent by Soxhlet apparatus. The optimum conditions for the extract were calculated based on the extract yield by varying four parameters: material quantity (A: 2–4 g), solvent quantity (B: 250–300 ml), mantle temperature (C: 65–75 °C) and extraction time (D: 1–3 hours) and optimized using a four factor three level Box–Behnken response surface design (BBD) coupled with desirability function methodology. Results showed that temperature and extraction time had significant effect on yield of extract. Optimum conditions for highest yield of extract (10.94%) are as follows: material quantity (2 g), solvent quantity (281.4 ml), temperature (72 °C) and time (3 hours). The extract at the maximum yield condition was analyzed for phytocomponents by FTIR and GC–MS. The results indicated the presence of Hydroxy chavicol (69.46%), 4-Chromanol (24%) and Eugenol (4.86%), which possess wide application including as antioxidant, anti-inflammatory, anti-platelet and antithrombotic, antibacterial and antifungal agents.

This paper presents a new procedure for finding the optimal placement of the phasor measurement units (PMUs) in modern power grids to achieve full network observability under normal operating conditions, and also abnormal operating conditions such as a single line or PMU outage, while considering the availability of PMU measuring channels. The proposed modeling framework is implemented using the fuzzy binary linear programming (FBLP) technique. Linear fuzzy models are proposed for the objective function and constraints alike. The proposed procedure is applied to five benchmark systems such as the IEEE 14-bus, 30-bus, 39-bus, 57-bus, and 118-bus. The numerical results demonstrate that the proposed framework is capable of finding a fine-tuned optimal solution with a simple model and acceptable solution characteristics compared with early works in the literature. Besides, four evaluation indices are introduced to assure the various criteria under study such as the observability depth, measurement redundancy, and robustness of the method under contingencies. The results show that full network observability can be met under normal conditions using 20% PMUs penetration; however, under contingencies, approximately 50% PMUs penetration is required. The novelty of the proposed procedure has proven the capability of the proposed linear fuzzy models to find better optimal number of PMUs with lower number of channels compared to other algorithms under various operating conditions. Hence, the proposed work represents a potential tool to monitor power systems, and it will help the operators in a smart grid environment.

Quenching characteristics of metallic vertical rod with an internal heater has been investigated in pure water and water-based nanofluid with alumina nanoparticles of 0.001% by volume. Initial temperature of the testing rod (12 mm diameter and 1000 mm length) ranges from 200 °C to 250 °C. The internal heater may be used to simulate the decay heat generated by the nuclear fuel rod after the power plant shutdown. Tests have been performed with varied range of experimental conditions of decay heat, constant water and nanofluid flow rates. The cooling curves follow a general trend of a rapid temperature drop up to almost 100 °C of the rod surface temperature irrespective of the operating parameters and the location of the thermocouple. The obtained results during quenching process indicated that HTC (heat transfer coefficient) for nanofluids are more than de-ionized water. It was also observed that in identical circumstances, the quenching time of the specimen in Al₂O₃ nanofluid considerably decreased as compared to water. The results exhibit that nanofluids can enhance the reflood heat transfer performance in terms of quenching rate for a long vertical rod causing liquid-droplets-induced depositions of nanoparticles resulting in making a pre-coating effect characterized by higher wettability.

Silver nanoparticles biosynthesis has received increasing attention in the field of nanotechnology due to their antimicrobial and biomedical applications. Green synthesis of metal nanoparticles is anticipated as a cost effective and eco-friendly alternative in the current research scenario. With this aim, the aqueous extracts made from the aerial parts of Lippia nodiflora were used as the reducing agents to synthesize silver nanoparticles (AgNPs) and their antioxidant, antibacterial and cytotoxic properties have also been evaluated. The biosynthesized AgNPs were characterized by UV–Visible Spectroscopy, Fourier-Transform Infrared Spectroscopy (FTIR) and X-Ray Diffraction (XRD) analysis. The AgNPs were found to be stable at −25.2 mV through zeta potential study. The morphology and size of synthesized silver nanoparticles were confirmed by Scanning Electron Microscope with energy dispersive spectra (SEM-EDX) and Transmission Electron Microscopy (TEM) analysis with size range from 30 to 60 nm. Biosynthesized AgNPs exhibited strong antioxidant activity as well as showed potent antibacterial activity against human pathogenic bacteria. The cytotoxicity study of AgNPs was also revealed against MCF-7 breast cancer cell lines in a dose-dependent manner. The recognized bioactivity confirmed by the synthesized AgNPs directs towards the clinical use as an antioxidant, antibacterial and cytotoxic agent.

This paper presents an application of Doppler SODAR (Sound Detection and Ranging) system for the assessment of wind characteristics at an onshore site in Tamil Nadu, India. The wind speed is statistically analyzed by means of Weibull distribution function and results were used to compute several characteristics parameters related to wind energy applications and no significant discrepancies were observed. The characteristics of wind shear coefficient were evaluated for different altitudes. The vertical profile of wind speed measured from SODAR system was compared with existing models. Furthermore, the turbulence characteristics were analyzed and compared along with the turbulence intensity. From the economic point of view the SODAR system was found to be cost-effective at higher heights. The results of this study are expected to provide useful information for the deployment of remote sensing instruments for wind energy development in India.