Kharazmi University

About: Kharazmi University is a education organization based out in Tehran, Iran. It is known for research contribution in the topics: Membrane & Supply chain. The organization has 3395 authors who have published 5321 publications receiving 45645 citations. The organization is also known as: Tarbiat Moallem University of Tehran & Teacher Training University.

Antinociceptive and anti-inflammatory effects of the aerial parts of Artemisia dracunculus in mice.

Abstract: Context: Tarragon (Artemisia dracunculus L., Asteraceae) is an ancient herb, which is widely used as a medicine, flavoring, or fragrance.Objective: To determine the antinociceptive and anti-inflammatory effects of aerial parts of tarragon, we investigated the effects of ethanolic extract of the plant in adult male Balb/c mice.Materials and methods: Antinociceptive activity was determined using formalin, hot-plate, and writhing tests. The effect of the ethanolic extract on acute inflammation was evaluated by xylene-induced ear edema in mice. The ethanolic extract was administered at doses of 5, 10, 50, and 100 mg/kg, i.p. The control group received saline as vehicle of ethanolic extract.Results: Our results showed that the ethanolic extract (50 and 100 mg/kg) decreased both phases of pain in the formalin test (ED50 = 109.66 and 87.13 mg/kg, respectively). In the hot-plate test, the extract (50 and 100 mg/kg) increased pain threshold during 60 min (ED50 = 81.03 mg/kg). The extract (50 and 100 mg/kg)...

Experimental investigation of first and second laws in a direct absorption solar collector using hybrid Fe 3 O 4 /SiO 2 nanofluid

Abstract: In this study, energy and entropy analysis of a residential-type direct absorption solar collector using hybrid Fe3O4/SiO2 nanofluid is evaluated experimentally. The hybrid nanofluid samples are prepared in the different volume ratios of Fe3O4/SiO2 (25:75, 50:50 and 75:25) and different volume fractions (500 ppm, 1000 ppm and 2000 ppm). The appropriate nanofluid samples for using as the working fluid of the collector are chosen based on the results of stability and optical properties of nanofluid. Then, outdoor thermal performance of collector is investigated using the experimental setup based on EN12975-2. Measurement of nanofluid optical properties using the spectrophotometry method shows that the extinction coefficient of 2000 ppm hybrid Fe3O4/SiO2 nanofluid is on average 10 cm−1 higher than that of the base fluid. Results of energy analysis display that the collector efficiency is increased by mass flow rate and volume fraction of nanofluid asymptotically. The asymptotic value is about 83% for 2000 ppm hybrid Fe3O4/SiO2 nanofluid. The findings indicate that the variation of exergy efficiency of a direct absorption solar collector with the volume fraction and mass flow rate is similar to energy efficiency. The enhancement of exergy efficiency is 66.4% for mass flow rates of 0.0225 kg s−1 by increasing the volume fraction from 0 to 2000 ppm. It is also observed that dimensionless entropy generation number is decreased by nanofluid volume fraction and by mass flow rate. The lowest entropy generation number is obtained in the mass flow rate of 0.0225 kg s−1 and the volume fraction of 2000 ppm. The variation of Bejan number by volume fraction shows that the contribution of pressure drop in entropy generation is insignificant.

Intriguing properties of unusual silicon nanocrystals

Abstract: Solar cell technologies are highly dependent on silicon materials and novel nanoclusters with optimal electronic properties. Based on a recent study on ultrastable silicon nanoclusters, an analysis of the effects of modifications of those nanocrystals by carboxylation, amidation, hydroxylation and halogenation has been performed using quantum mechanical methods of study. Here we report the gaps, electronic structures, absorption spectra, and effects on the charge-transfer potential of a collection of modified silicon nanoclusters. The results show that the pristine silicon clusters retain the highest charge-transfer properties and that halogenation impacts on the charge-transfer effects in a proportional fashion to the electronegativity of the employed halogens. Modification with organic molecules does not improve charge-transfer properties, and gives instead the highest reduction of charge-transfer potentials of the silicon clusters. The effects of the modification have also been studied in context with the orbital configurations through wave function analysis, which reveals that the electrostatic properties of the nanoclusters are mainly represented by a significant polarization of the electrostatic energy between the peripheral regions of the clusters and their core, a feature particularly well-preserved in the pristine silicon clusters. Modifying the particles by adding an extra atom at their core shows significant effects on the molecular orbital properties (HOMO/LUMO). However, this modification does not contribute to an actual increase in charge-transfer integrals. The modifications induce, however, interesting effects on the overall configuration of the clusters; i.e., they increase the aromatic character of the inter-atomic bonding pattern. Halogenation has the highest effect on improving aromatic properties for the silicon clusters, where chlorination gives the highest degree of aromaticity. This study introduces valuable electronic data for engineering novel silicon nanoclusters for application in solar cell technologies, computing units, and other fields such as in aerospace engineering.

The Effect of Valgus Control Instruction Exercises on Pain, Strength, and Functionality in Active Females With Patellofemoral Pain Syndrome.

Abstract: Background:Patellofemoral pain syndrome (PFPS) is sometimes related to excessive hip adduction and internal rotation, as well as knee valgus during weightbearing activities in females. Research on ...