Microgrid finance,revenue, and regulation considerations

This article is intended to serve as an introduction to planning considerations for decision makers of critical public and large private infrastructures and assets pursuing microgrids. The specific planning considerations outlined in this article include gathering regulatory and financial information necessary to facilitate technical and economic analysis, project evaluation, and implementation. This will inform preliminary analysis, site screening, and feasibility studies, as well as provide an overview of financial mechanisms available for microgrids.     

Performance analysis of hybrid/single nanofluids on augmentation of heat transport in lid-driven undulated cavity

This numerical study reveals the heat transfer performance of hybrid/single nanofluids inside a lid-driven sinusoidal trapezoidal-shaped enclosure. The right and left inclined surfaces of the trapezium have been considered as insulated, whereas the bottom sinusoidal wavy and the flat top surfaces of the enclosure as hot and cold, respectively. The governing partial differential equations of fluid's velocity and temperature have been resolved by applying the finite element method. The implications of Prandtl number (4.2-6.2), Richardson number (0.1-10.0), undulation number (0-3), nanoparticles volume fraction (0%-3%), and nanofluid/base fluid (water, water–copper (Cu), water–Cu–carbon nanotube, water–Cu–copper oxide (CuO), water–Cu–TiO₂, and water–Cu–Al₂O₃) on the velocity and temperature profiles have been studied. Simulated findings have been represented by means of streamlines, isothermal lines, and average Nusselt number of above-mentioned hybrid nanofluids for varying the governing parameters. The comparison of heat transfer rates using hybrid nanofluids and pure water has been also shown. The heat transfer rate is increased about 15% for varying Richardson number from 0.1 to 10.0. Blending of two nanoparticles suspension in base fluid has a higher heat transfer rate—approximately 5% than a mononanoparticle. Moreover, a higher average Nusselt number is obtained by 14.7% using the wavy surface than the flat surface of the enclosure. Thus, this study showed that applying hybrid nanofluid may be beneficial to obtain expected thermal performance.     

Fast removal of Pb(II) and Cu(II) from contaminated water by groundwater treatment waste: impact of sorbent composition

ABSTRACT

A non-hazardous groundwater treatment waste (GWTW) was examined as a low-cost sorbent for Pb(II) and Cu(II) ions. The content of the dominant elements in GWTW was as follows: 78% Fe₂O₃, 7.4% P₂O₅, 7.4% CaO and 5.2% SiO₂. The removal of Pb(II) and Cu(II) was fast, and more than 67–95% of ions were accumulated by GWTW during the first 3 min. The sorption capacity of GWTW depends on solution pH, concentration and temperature. Equilibrium data fitted well with Langmuir–Freundlich and Langmuir-partition models. The inherently formed nano-adsorbent could be utilized for the treatment of water contaminated with Pb(II) and Cu(II) ions.     

Lighting preferences in office spaces concerning the indoor thermal environment

The accurate prediction of the visual comfort zone in an indoor environment is difficult as it depends on many parameters. This is especially the case for large compact urban areas in which the density and shadow from neighboring buildings can limit the accessible daylighting in indoor spaces. This paper investigates the satisfaction range for illuminance regarding indoor air temperature in office buildings and the significant parameters affecting this range in six office buildings in Tehran, Iran. Lighting comfort has been evaluated by a subjective survey (509 total responses) and field measurement. The questionnaires were filled out in 146 and 109 rooms in summer and winter, respectively. The results show that the illuminance should not be less than 550 lx, while illuminance between 600 and 650 lx provides the highest satisfaction level. The satisfaction with lighting level is affected by individual parameters such as age, type of activity, and environmental parameters such as window orientation, external obscurations, and season. A relationship was observed between lighting level satisfaction and thermal condition acceptance, and the overall comfort depends more on thermal conditions than the lighting level.     

Investigation of charge transport mechanism in semiconducting La<Subscript>0.5</Subscript>Ca<Subscript>0.5</Subscript>Mn<Subscript>0.5</Subscript>Fe<Subscript>0.5</Subscript>O<Subscript>3</Subscript> manganite prepared by sol–gel method

Here in, we report the charge transport mechanism in semiconducting La_0.5Ca_0.5Mn_0.5Fe_0.5O₃ (LCMFO) polycrystalline material synthesized via sol–gel auto combustion route. X-ray diffraction (XRD) analysis confirmed the orthorhombic phase of the prepared material. Temperature dependent resistivity and impedance spectroscopy measurements have been carried out to probe the dielectric and electrical conduction mechanism which revealed a change of Mott variable range to the small polaronic hopping conduction mechanism around 303 K. The complex impedance and modulus spectra undoubtedly showed the contribution of both grain and grain boundary effect on the conduction properties of LCMFO. An equivalent circuit [(R_gbQ_gb) (R_gQ_g)] model has been used to address the electrical parameters associated with the different phases (grains and grain boundaries) having different relaxation times. The values of resistances of two phases obtained after fitting the equivalent circuit in the nyquist plot have been analyzed which confirmed the change of conduction mechanism around 303 K. The resultant change in conduction mechanism is also supported by the conductivity plots.     

Silicon Application Enhances the Photosynthetic Pigments and Phenolic/Flavonoid Content by Modulating the Phenylpropanoid Pathway in Common Buckwheat under Aluminium Stress

Silicon - Silicon (Si) is very effective in the amelioration of heavy metal (HM) stress in different crop plants. This investigation was conducted to assess the protective role of Si in modulating...     

Antimicrobial and antioxidant activities of Chinese sumac (Rhus typhina L.) fruit extract

Sumac plant (Rhus typhina) is mainly used for forestation and gardening, whereas its fruit can be used to prepare a kind of beverage called “sumac-ade” and to treat gastrointestinal disorders. This study aimed at assaying the antimicrobial and antioxidant activities of R. typhina growing in China. The antimicrobial activity of R. typhina fruit extract was tested against twelve strains including Gram-positive and Gram-negative bacteria as well as yeasts. The extract showed a strong antimicrobial activity with a concentration-dependence and a broad antimicrobial spectrum for all tested bacteria species. Bacillus cereus and Helicobacter pylori were found to be the most sensitive Gram-positive and Gram-negative bacteria respectively, with a minimum inhibitory concentration (MIC) of 0.10%. However, yeasts exhibited much lower sensitivity, with MICs of 0.60–0.75%. Furthermore, the antioxidant activity of the extract was investigated, including scavenging activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals (0.016 mg/ml as IC₅₀ value) and reducing power (IC₅₀ value of 0.041 mg/ml). To our knowledge, this is the first report on the biological activities of R. typhina fruit extract and our findings suggest the possibility of using the fruit of R. typhina as a novel source of natural antimicrobial and antioxidant agents for the food and pharmaceutical industries.     

汽油中烃类物质的太赫兹时域光谱研究

本文应用太赫兹时域光谱技术研究了在室温氮气环境下催化裂化汽油中芳烃、烯烃的光学性质,以芳烃中二甲苯、均三甲苯及烯烃中二异丁烯为例,分析了含有不同浓度二甲苯、均三甲苯和二异丁烯的催化裂化汽油在太赫兹波段的光谱效应。结果表明,汽油中不同浓度的芳烃和烯烃具有不同的吸收谱和折射率特性。根据太赫兹光谱包含的特征信息能够对汽油中芳烃、烯烃成分进行定性分析,从而为汽油中烃含量的定量检测做基础。     

Distribution of almond polyphenols in blanch water and skins as a function of blanching time and temperature

The distribution of polyphenols in blanched almond skins and blanch water, as a function of time and temperature, was quantified using negative ion electrospray time-of-flight mass spectrometry (ESI TOF MS). Almonds were blanched in 25° (RT) and 100 °C (HW) water for up to 10 min. At 10 min, ∼30% (25°) and 90% (100 °C) of the polyphenols quantified had leached from the skins into the blanch water. Many of the compounds precipitated from the blanch water due to limited water solubility, as evidenced by a logarithmic fit to kinetic data (1st order kinetics). The rate of procyanidin degradation into smaller polymeric units (e.g., catechin and epicatechin) also increased as a function of time and temperature. Finally, hydration in RT water increased the extraction efficiency of phenolics by 25%. This work shows that the blanch water, in particular the 100 °C blanch water, was rich in polyphenols and supports exploration of alternative uses for blanch water.     

The Binding of Anionic Dyes by Cross-Linked Cationic Starches

Adsorption of anionic dyes on the cross-linked with epichlorohydrin starches containing quaternary ammonium groups (CCS) was investigated and compared with that of modified starches containing only quaternary ammonium groups (CS). The adsorption of anionic dyes on CS and CCS closely follows the Langmuir model of adsorption. The computed Langmuir saturation capacity Q _o increases with increasing degree of substitution (DS) of CS or CCS and has the value from 0.81 mol/kg to 3.22 mol/kg for CCS and from 0.88 mol/kg to 1.87 mol/kg for CS. The effectiveness of the cationic groups in dye binding was about 1 mol/equiv for CSS with DS from 0.47 to 0.62 and all the cationic groups had attached one anionic groups of the dye. Increasing DS of CS decreases the effectiveness of dye binding due to the increase in solubility of CS, and the soluble part of CS binds the dye as a typical soluble polyelectrolyte. CCS are more suitable than CS for the anionic dye adsorption from a textile dyeing solution. DS of CCS should be about 0.5–0.6. They adsorb the anionic dyes in few minutes and acts in the wide range of pH of the solutions. The Langmuir saturation capacity Q _o and the effectiveness of the cationic groups in dye binding increase with an increase of the adsorption temperature. The positive values of the enthalpy and entropy suggest that the adsorption is endothermic and during the adsorption of the anionic dye on CCS the randomness of the system increases.