25 research outputs found

    Photochemical reduction of silver nitrate to nano silver using stannous chloride, ctab and daylight irradiation

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    Silver nanoparticles (NPs) were synthesized and stabilized by a simple method in aqueous solution, by the reduction of silver nitrate with stannous chloride (SnCl2.2H2O) and cetyl trimethyl ammonium bromide (CTAB)through day light irradiation. Thereby, the silver nanoparticles were colloidally stabilized by CTAB as a surfactant. The synthesis of silver NPs with different size were possible by changing the reaction conditions such as reagent ratio. The silver NPs were characterized by Dynamic Light Scattering (DLS) and UV-visible spectroscopy. A very strong plasmon resonance peak at 400-500 nm in the UV-visible spectra is a clear consequence of the silver NPs production. The synthesized silver NPs showed good stability by using CTAB. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2063

    Effect of Roasting on Fatty Acid Profile of Brown and Yellow Varieties of Flaxseed (Linum usitatissimum L)

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    Purpose: To monitor changes in fatty acid profiles of brown and yellow varieties of flaxseeds in the raw and roasted states using gas chromatography (GC).Methods: Samples of flaxseeds were extracted with n-hexane in a Soxhlet apparatus for 8 h. Methylesterification of the samples was performed by methanolic boron trifluoride (BF3-MeOH) method according to American Oil Chemists' Society (AOCS). Fatty acid (FA), analyzed using GC equipped with a split/splitless capillary injector and flame ionization detector (FID).Results: The results indicate that lipid content varied with the type of seed. Seed oil content was 53.31 ± 0.30 and 45.20 ± 0.20 % for roasted and unroasted brown flax, respectively, and 10.25 ± 0.04 % for the yellow type. The yellow and roasted brown type, at 300oC, showed the lowest and highest oil content, respectively. The highest calculated oxidizability (COX) value was found for the unroasted brown type (13.19 ± 0.01 %) whilst the lowest amount was observed for the roasted brown seed at 350oC (12.79 ± 0.01 %). COX value for yellow type was 5.62 ± 0.01 %.Conclusion: This study shows that the fatty acids content of flaxseeds vary with roasting conditions. This is significant because flax seed fatty acid composition influences the applications of the oil.Keywords: Oil, Flaxseed, Roasting, Fatty acid, Linum usitatissimum, Calculated oxidizability valu

    Constipation and laxative herbs in Iranian traditional medicine

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    Context: Constipation is one of the most prevalent gastrointestinal disorders and is characterized by stiffness of waste and difficult defecation. In modern medicine, different laxative drugs are used for the treatment of constipation, but they are not without side effects. Nonetheless, the appropriate use of herbal medicines can be beneficial for treating this disorder. Therefore, this study attempted to draw together some pharmacological and medical insights into the management of constipation through the use of Iranian traditional medicine (ITM). Evidence Acquisition: In this review article, we initially researched constipation and laxative herbs using some of the most famous ancient medical and pharmacological textbooks pertaining to Iranian medicine written from the 10th to 18th century AD. This includes The canon of medicine by Avicenna (10th and 11th centuries, Beirut publication), Makhzan-ol-advie by Aghili (18th century, Tehran University of Medical Science Press), and Al-shamel by Gharashi (13th century, Caltural foundation Publication). Then we extracted the names and laxative mechanisms of some herbs prescribed for constipation through ITM. Finally, a search of scientific databases such as PubMed and Google Scholar was performed to find related works concerning laxative mechanisms. Results: In ITM doctrine, laxatives are weak purgatives that lead to the defecation of waste from the gastrointestinal tract. From this perspective, laxative herbs can be classified into two groups based on their nature: laxative herbs with a hot nature cause the dilution and flowing of humors, but herbs with a cold nature function as laxatives due to their mucilage properties. Each of the laxatives was used in accordance with the primary reason for constipation. Conclusions: This study presents medical and pharmacological approaches in ITM for dealing with complications arising from constipation. Considering the optimistic results, these herbs can be used as a means of constipation management and further investigation into this area can potentially lead to the formulation of new drugs. © 2016, Iranian Red Crescent Medical Journal

    Evaluating the Effects of Dual Frequency Sonication Parameters on Acoustic Cavitation by Chemical Dosimeter Using Iodide

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    Abstract: Background and Aims: Production of acoustic cavitation by sonication has been recently recommended as a targeted treatment. The experimental results from studies indicate that the activity of cavitation generated by bi- or multi-frequency ultrasound irradiation is higher than that caused by single frequency irradiation. In this study, effects dual (1 MHz and 40 kHz) and single frequency sonication on acoustic cavitation were investigated by chemical dosimeter using iodide. Methods: In this study, we investigated the exposure parameters in low level dual-frequency ultrasound in near fields of 40 kHz and 1 MHz in the progressive wave mode by chemical dosimeter using iodide. Finally, the effective protocol for enhancement of the inertial cavitation activity was determined. Results: It has been shown that the dosimeter absorbance in the continuous mode sonication is more than the pulse mode. Moreover, significant correlations were found between the time and intensity of single and dual frequency sonication and the iodide dosimeter absorbance. In constant energy, inertial cavitation activity in the pulse mode remained approximately constant. Among different combinations, the combined ultrasound sonication in continuous mode could produce a more remarkable enhancement of the inertial cavitation activity (1.78 times) than the algebraic sum. Conclusion: Simultaneous combined dual frequency sonication is more effective than single frequency sonication in producing the inertial cavitation activity. Keywords: Ultrasound waves, Acoustic cavitation, Dual frequency sonication, Chemical dosimeter using iodid

    A new topology for unipolar brushless DC motor drive with high power factor

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    Drug release behavior of electrospun twisted yarns as implantable medical devices

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    In this study, twisted drug-loaded poly(L-lactide) (PLLA) and hybrid poly(L-lactide)/poly(vinyl alcohol) (PLLA/PVA) yarns were produced using an electrospinning technique based on two oppositely charged nozzles. Cefazolin, an antibiotic drug was incorporated in the yarn fibers by addition to the PLLA electrospinning solution. Morphological studies showed that independent of the twist rate, uniform and smooth fibers were formed. The diameter of the electrospun fibers in the yarns decreased at higher twist rates but produced yarns with larger diameters. At increasing twist rates the crystallinity of the fibers in the yarns increased. In the presence of cefazolin the fiber diameter, yarn diameter and crystallinity were always lower than in the non-drug loaded yarns. In addition the yarn mechanical properties revealed a slightly lower strength, modulus and elongation at break upon drug loading. The effect of the twist rate on the cefazolin in vitro release behavior from both PLLA and hybrid yarns revealed similar profiles for both types of drug-loaded yarns. However, the total amount of drug released from the hybrid PLLA/PVA yarns was significantly higher. The release kinetics over a period of 30 d were fitted to different mathematical models. Cefazolin release from electrospun PLLA yarns was governed by a diffusion mechanism and could best be fitted by Peppas and Higuchi models. The models that were found best to describe the drug release mechanism from the hybrid PLLA/PVA yarns were a first-order model and the Higuchi model

    Motor Integrated Permanent Magnet Gear with a Wide Torque-Speed Range

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    On Line Current Monitoring and Application of a Residual Method for Eccentricity Fault Detection

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    This work concerns the monitoring and diagnosis of faults in induction motors. We develop an approach based on residual analysis of stator currents to detect and diagnose faults eccentricity static, dynamic and mixed in three phase induction motor. To simulate the behavior of motor failure, a model is proposed based on the approach of magnetically coupled coils. The simulation results show the importance of the approach applied for the detection and diagnosis of fault in three phase induction motor
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