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دسترسی آزاد مقاله
1 - Dielectric, electro-optical and spectroscopic properties of silver doped zinc oxide-ferroelectric liquid crystal composite system
Kaushlendra Agrahari Sanjeev Trivedi Ram Awasthi Vivek Nautiyal Rakesh Sonker Rajiv ManoharIn the present study, silver doped zinc oxide nanoparticles (NPs) have been added in the pristine ferroelectric liquid crystal (FLC). The dielectric, electro-optical and spectroscopic properties was investigated of the pristine FLC and FLC-NPs composite system. The disp چکیده کاملIn the present study, silver doped zinc oxide nanoparticles (NPs) have been added in the pristine ferroelectric liquid crystal (FLC). The dielectric, electro-optical and spectroscopic properties was investigated of the pristine FLC and FLC-NPs composite system. The dispersion of NPs into the pristine FLC material sturdily influences the various properties of composite system. Due to dispersion of NPs, a rapid increment in the dielectric permittivity and faster switching was observed for the FLC-NPs composite system. Absorbance of the UV light got diminished in the presence of silver doped zinc oxide NPs. Photoluminescence emission of the pristine FLC material has been quenched after the addition of NPs and a red shift was also detected. The possible applications of this investigation have been suggested in the letter. پرونده مقاله -
دسترسی آزاد مقاله
2 - Effect of ion trapping behavior of TiO2 nanoparticles on different parameters of weakly polar nematic liquid crystal
Geeta Yadav Rohit Katiyar Govind Pathak Rajiv ManoharAbstractIn the present investigation, TiO2-doped weakly polar nematic liquid crystal (NLC) has been studied. This study mainly focuses on dielectric, electro-optical and optical properties of pure NLC and doped systems. Variation in different parameters like dielectric چکیده کاملAbstractIn the present investigation, TiO2-doped weakly polar nematic liquid crystal (NLC) has been studied. This study mainly focuses on dielectric, electro-optical and optical properties of pure NLC and doped systems. Variation in different parameters like dielectric permittivity, dielectric loss, dielectric anisotropy and conductivity has been noticed. Permittivity of the doped system is almost the same as undoped system. With doping concentration, the ionic contribution to the dielectric loss as observed in low-frequency region has been suppressed and the shift in relaxation frequency toward higher frequency side has also been observed. The electrical conductivity and threshold voltage have been decreased with increasing concentration of nanoparticles (NPs). The continuous increase in dielectric anisotropy with increasing the concentration of NPs has also been observed. These results have been attributed to the trapping capability of free ions by TiO2 NPs. Further, we focused on the study of photoluminescence (PL), UV absorbance and Fourier transformed infrared spectroscopy (FTIR) of pure and doped systems. The continuous increase in PL intensity without any shift in emission peak has been observed for doped systems. Enhancement in UV absorbance with increasing concentration of NPs has also been observed. The effect of NPs doping on molecular dynamics of NLC can be clearly seen by FTIR study. The results suggest that the TiO2 NP-doped weakly polar NLC can have significant improved dielectric, electro-optical and optical properties. This makes the weakly polar NLC to be a potential candidate for many applications. پرونده مقاله -
دسترسی آزاد مقاله
3 - Comparison of food intake groups, dietary oxygen radical absorbance capacity (ORAC), and their relationship with atherogenic indices of plasma in patients with metabolic syndrome and healthy individuals
Mohammadreza Esfehani Farzad Eidi Ariyo MovahediThe increasing prevalence of metabolic syndrome on the one hand and its relationship with other chronic non-communicable diseases on the other hand has led to many studies to investigate the causes of metabolic syndrome or its components. This study was a case-control s چکیده کاملThe increasing prevalence of metabolic syndrome on the one hand and its relationship with other chronic non-communicable diseases on the other hand has led to many studies to investigate the causes of metabolic syndrome or its components. This study was a case-control study that was performed on 160 men and women (80 individuals with metabolic syndrome and 80 healthy individuals) with a mean age of 47.8 years. In this study, demographic questionnaires, 147-item feed frequency, anthropometric and body composition information, blood pressure, and a fasting blood sample were taken from all subjects. All data were analyzed using SPSS software. People with metabolic syndrome had higher intakes of cereals, offal, fruits, oils, and snacks, and the differences were significant. Also, the mean atherogenic plasma index (AIP), cardiac risk ratio, and atherogenic coefficient (AC) in the group of patients with metabolic syndrome were higher significant than in the patients. However, there was no significant difference between the ORAC diet in the healthy and affected groups. There was also no association between dietary ORAC and AIP. Among the food groups, only nuts and viscera were not associated with the ORAC diet, but more food groups such as legumes, meats, fast foods, vegetables, spices, nuts, tea, coffee, and sugars were not associated with AIP. The results also showed that according to AIP values, 71.3% of healthy people are at risk of developing metabolic syndrome. According to the results, it seems that indicators related to the quality of dietary fat have an effective role in the development of metabolic syndrome and its components. However, the ORAC index did not have a significant effect on the development of the metabolic syndrome and its components and was associated only with the intake of many food groups. پرونده مقاله -
دسترسی آزاد مقاله
4 - معرفی دوکفهای( Corbicula fluminea ) به عنوان جاذب زیستی آلاینده نانوذرات اکسید روی در دوره کوتاه مدت
فاطمه بهاروند فاطمه پرویزی امیر قادرمزی زهرا عرب علی اکبر هدایتی محمدشریف رنجبردراین مطالعه میزان جذب مستقم نانوذرات اکسید روی توسط دوکفه ای Corbicula fluminea در دوره کوتاه مدت 48 ساعتی بررسی گردید. تعداد مورد نیاز دوکفه ایCorbicula fluminea با دامنه طولی cm 9/0±5/2 از محیط طبیعی استحصال گردید. نمونه ها به آزمایشگاه انتقال داده شدند و برای چکیده کاملدراین مطالعه میزان جذب مستقم نانوذرات اکسید روی توسط دوکفه ای Corbicula fluminea در دوره کوتاه مدت 48 ساعتی بررسی گردید. تعداد مورد نیاز دوکفه ایCorbicula fluminea با دامنه طولی cm 9/0±5/2 از محیط طبیعی استحصال گردید. نمونه ها به آزمایشگاه انتقال داده شدند و برای رفع استرس به مدت 10 در آکواریم قرار گرفتند. نانوذرات با استفاده از دستگاه التراسونیک با 400 دور در دقیقه پخش گردید. جهت یک فاز شدن آب مخازن دوکفه ای با محلول نانو ذره از دستگاه هموژنایزر با 14000 دور در دقیقه استفاده شد و تیمارها با غلظت های 25/. ؛ 5/ 2و ppm 25 مواجهه داده شدند و گروه کنترل فاقد نانوذره در نظر گرفته شد. انباشت نانو ذرات در توده بافتی دوکفه ای با دستگاه ICP و نحوه توزیع نانوذرات در مخازن دوکفه ای با تست DLS سنجیده شد. نتایج مربوط بهICP نشان داد بیشترین میزان انباشت نانوذرات دربدن دوکفه ای در کمترین غلظت مواجهه (P < 0.05) مشاهده شد. و کمترین میزان جذب در بالاترین غلظت مواجهه به صورت معنی داری (P < 0.05) نسبت به سایر تیمارها مشاهده شد. نتایج تست DLS نشان داد که ذرات از لحاظ اندازه بین 100-10 نانومتر بوده اند که مؤید عدم ترسیب و هموژن بودن نانوذرات در کف مخازن حاوی دوکفه ای بوده است. بر اساس نتایج به دست آمده از این مطالعه می توان گفت میزان جذب در دوکفه ای به عنوان شاخص بسیار مناسبی جهت پایش اثرات نانو ذرات اکسیدروی در محیط های آبی پیشنهاد می شود پرونده مقاله
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