Passive cooling in hot,arid regions in developing countries by employing domed roofs and reducing the temperature of internal surfaces

Natural ventilation due to wind effects through buildings employing domed roofs was estimated by a flow network analysis. The dome was assumed to have an opening at its crown. When compared with flat roofs, the domed roofs always increase the air flow rate through the building. The increase in natural ventilation becomes significant in buildings with doors and windows all in one wall, or whenever the wind effects on the building envelope do not produce large pressure differences at the openings.The large air flow rate in the buildings with domed roofs may be utilized to store night air coolness in the structure more effectively and keep the mean radiant temperature of the interior surfaces low for thermal comfort in summer. The lowest internal surface temperatures can be obtained when the surfaces are kept moist and evaporatively cooled.Through a one-dimensional energy analysis the inside surface temperature of a horizontal slab was estimated for various slab materials and thicknesses and external and internal conditions. The inside surface temperature was compared with the case of employing a roof pond. It was found that lower temperatures can be obtained by evaporatively-cooled moist internal surfaces than that which can be obtained by unshaded roof ponds: For a building whose internal surfaces (walls and ceiling) are kept moist a large ventilation rate is needed to prevent water vapor build-up in the space. A domed roof with a hole in its crown can produce the necessary ventilation for such a building.     

Accurate estimation of CO2 adsorption on activated carbon with multi-layer feed-forward neural network (MLFNN) algorithm

Global warming due to greenhouse effect has been considered as a serious problem for many years around the world. Among the different gases which cause greenhouse gas effect, carbon dioxide is of great difficulty by entering into the surrounding atmosphere. So CO₂ capturing and separation especially by adsorption is one of the most interesting approaches because of the low equipment cost, ease of operation, simplicity of design, and low energy consumption.In this study, experimental results are presented for the adsorption equilibria of carbon dioxide on activated carbon. The adsorption equilibrium data for carbon dioxide were predicted with two commonly used isotherm models in order to compare with multi-layer feed-forward neural network (MLFNN) algorithm for a wide range of partial pressure. As a result, the ANN-based algorithm shows much better efficiency and accuracy than the Sips and Langmuir isotherms. In addition, the applicability of the Sips and Langmuir models are limited to isothermal conditions, even though the ANN-based algorithm is not restricted to the constant temperature condition. Consequently, it is proved that MLFNN algorithm is a promising model for calculation of CO₂ adsorption density on activated carbon.     

Functional components,antidiabetic, anti-Alzheimer’s disease,and antioxidant activities of Salvia syriaca L.

Antidiabetic, anti-Alzheimer, general toxicity, and antioxidant activities of Salvia syriaca were evaluated. Phytochemical composition of the essential oil and methanolic extract of the plant were identified using gas chromatography-mass spectrometry and reverse-phase high-performance liquid chromatography-diode array detector techniques, respectively. Essential oil of S. syriaca exhibited strong cytotoxicity, antioxidant, α-amylase, and α-glucosidase inhibitory activities. Gas chromatography-mass spectrometry analysis showed that spathulenol (87.4%), isospathulenol (7.6%), and bornyl acetate (2.7%) are the major compounds in essential oil. High-performance liquid chromatography analysis indicated that rutin, quercetin, apigenin, rosmarinic acid, and ferulic acid are the most abundant phenolic components. S. syriaca could be considered as a valuable source of bioactive natural compounds for functional foods, medical, and pharmaceutical applications.     

Comparative study of the essential oil composition of Salvia urmiensis and its enzyme inhibitory activities linked to diabetes mellitus and Alzheimer’s disease

The genus Salvia has economic importance due to its broad uses in traditional medicine, perfume, food, and pharmaceutical industries. In the present work, various extracts and essential oils of Salvia urmiensis Bunge., were screened for their inhibitory activity against acetylcholinesterase and butyrylcholinesterase, the enzymes linked to neurodegeneration, and against α-amylase and α-glucosidase (involved in diabetes mellitus; DM). Chemical compositions of the essential oils of leaves and flowers of the plant were also determined. The tested samples exhibited moderate to high anti-diabetic potential (IC₅₀ = 8–145 µg/mL) and moderate anticholinesterase activity (IC₅₀ = 44–892 µg/mL). Essential oil of leaves was rich in ester compounds such as ethyl linoleate (19%), methyl hexadecanoate (17%), and methyl linoleate (7.5%). The major compound of essential oil of flowers was 6,10,14-trimethyl-2-pentadecanone (55.7%). This is the first report on the enzyme inhibitory activity of S. urmiensis and also the chemical composition of its leaves and flowers in essential oils. The results indicated that S. urmiensis could be considered a valuable source for functional foods and pharmaceuticals.     

Covalent organic frameworks (COFs) quantum dots as supramolecular cages modified with biochar as nanobio photocatalyst for degradation of organic dyes

In this study, we used co-precipitation assisted solvothermal route to produce self-assembled covalent organic frameworks (COFs) quantum dots modified with biochar structures. In addition, photocatalytic degradation of organic dyes such as methyl red, methyl orange and methyl blue were measured without the need to artificial UV visible light in vitro condition, and degradation rate was estimated at alternate times. The biochar as precursor agent with hydrothermal method as an eco-friendly synthesis route used to provides COFs quantum dot nanostructures with appropriate diameter and size about 3.68 nm. This research presents a new and novel nanocomposite structures with the contribution of biochar as biological material for decolorization of methylene red, orange and blue were calculated using UV–vis spectroscopy. Novel covalent organic frameworks quantum dot membranes with high purity were synthesized and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transition electron microscopy (TEM), Atomic force microscopy (AFM), Fourier transformed infrared spectrum (FT-IR), thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC) and Brunauer–Emmett–Teller (BET) surface area analysis. Results clearly indicate which self-assembled COFs quantum dots as supramolecular cages modified with biochar synthesized with the cost-effective method act as a high performance photocatalyst for degradation of methylene red, orange and blue organic dyes.