-
دسترسی آزاد مقاله
1 - Effect of different drying methods on Vitamin D content in <i>Agaricus bisporus</i> Mushroom
Anousheh Sharifan Mina Kouhi Qobad Asgari JafarabadiVitamin D is a significant nutrient in a human’s diet and its deficiency has become a noticeable problem in the world. This study tried to evaluate the effective factors in preserving vitamin D in dried mushrooms using sunlight and ultraviolet light (UV-C). The ef چکیده کاملVitamin D is a significant nutrient in a human’s diet and its deficiency has become a noticeable problem in the world. This study tried to evaluate the effective factors in preserving vitamin D in dried mushrooms using sunlight and ultraviolet light (UV-C). The effect of irradiation on vitamin D2 and D3 in Agaricus bisporus mushroom was investigated. In this study, mushrooms were cut (in 5 mm) and dried in two ways of hot air and freeze-drying at 60 ℃ for 60min and -50 ℃ for 24 h respectively, then powdered and after that, the powders were exposed to the sunlight and UV for 5, 15 and 30 min and finally the amount of vitamin D was measured by HPLC spectrometer. The highest vitamin D2 content was observed in a mushroom powder dried by freeze dryer and exposed to sunlight for 5 min and also the one which was irradiated with UV for 30 min. The highest vitamin D3 content was observed in a mushroom powder dried by the hot dryer and exposed to sunlight for 30 min and the mushroom powder dried by freeze dryer and then irradiated with UV for 30 min. Applying ultraviolet light and sunlight in dried mushrooms increased vitamin D levels. The results of this study showed that the drying methods of mushroom were effective in maintaining and increasing the amount of vitamin D3 in the foodstuff. پرونده مقاله -
دسترسی آزاد مقاله
2 - مطالعه فعالیت مهارکنندگی آنتی‌اکسیدان ریبوفلاوین در حضور نور خورشید
الهه وهابی نژاد محمد مومن هرویمقدمه: رادیکال های آزاد، محصولات جانبی طبیعی سوخت و ساز بدن به شمار می روند که در حضور آنتی اکسیدان ها اثر این رادیکال های آزاد خنثی شده و آسیب های ناشی از آنها کمتر می شود. یکی از آنتی اکسیدان های طبیعی ریبوفلاوین می باشد که در بیشتر مواد گیاهی و حیوانی وجود دارد. مولک چکیده کاملمقدمه: رادیکال های آزاد، محصولات جانبی طبیعی سوخت و ساز بدن به شمار می روند که در حضور آنتی اکسیدان ها اثر این رادیکال های آزاد خنثی شده و آسیب های ناشی از آنها کمتر می شود. یکی از آنتی اکسیدان های طبیعی ریبوفلاوین می باشد که در بیشتر مواد گیاهی و حیوانی وجود دارد. مولکول ریبوفلاوین یک ماده حساس به نور نیز هست که از طریق واکنش فوتوشیمیایی باعث ایجاد تغییر شیمیایی در مولکول های مجاور می شود. خاصیت آنتی اکسیدانی ریبوفلاوین متاثر از تابش نور بوده و حساسیت آن به نور باعث بازده بیشتر خاصیت آنتی اکسیدانی آن می شود. مواد و روش ها: در این پژوهش چهار پارامتر مهم شامل دما، غلظت ریبوفلاوین، زمان و تابش دهی نور بر خاصیت آنتی اکسیدانی ریبوفلاوین مورد بررسی قرار گرفت. برای این منظور، فعالیت آنتی اکسیدانی ریبوفلاوین بر اساس فعالیت مهار رادیکال آزاد پایدار دی فنیل پیکریل هیدرازیل (DPPH) به وسیله دستگاه اسپکتروفوتومتر UV-Vis تعیین شد. یافته ها: فعالیت آنتی اکسیدان ریبوفلاوین با افزایش غلظت در گستره غلظتی 7/0-4/0 میلی مولار بیشتر شد. در حضور نور خورشید فعالیت آنتی اکسیدانی ریبوفلاوین به گونه ای است که رادیکال آزاد DPPH را به طور کامل مهار می کند. همچنین در گستره دمایی به کار رفته، با افزایش دما فعالیت آنتی اکسیدان در مهار رادیکال آزاد شدیدتر شده است. از نظر سینتیکی، واکنش مهار رادیکال آزاد DPPH با استفاده از معادله سینتیک مرتبه یک توصیف شد. نتیجه گیری: با توجه به مطالعه انجام شده ریبوفلاوین به عنوان یک ماده حساس نوری دارای خاصیت آنتی اکسیدانی قابل ملاحظه ای در مهار رادیکال آزاد DPPH در حضور نور خورشید می باشد. پرونده مقاله -
دسترسی آزاد مقاله
3 - Aloe Vera gel extract and sunlight mediated synthesis of silver nanoparticles with highly effective antibacterial and anticancer activity
Noha Mohamed Hossam ElmasryIn this study, a single-step method for green synthesis of silver nanoparticles using Aloe Vera gel extract and sunlight was investigated. The Aloe Vera gel extract is composed of pectins, lignin, and hemicellulose, which can be used in the reduction of silver ions to p چکیده کاملIn this study, a single-step method for green synthesis of silver nanoparticles using Aloe Vera gel extract and sunlight was investigated. The Aloe Vera gel extract is composed of pectins, lignin, and hemicellulose, which can be used in the reduction of silver ions to produce colloidal silver nanoparticles (AgNPs-AV). The preliminary preparation of silver nanoparticles was observed by an immediate color change to brown. The prepared silver nanoparticles were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, dynamic light scattering, and zeta potential measurements. Additionally, the cytotoxicity and antimicrobial activity of AgNPs-AV was tested. Results indicated the formation of stable spherical 90±40nm with a strong absorption peak appears between 400 and 500 nm. 28.7 ±0.781% of breast cancer cells survived after incubation with AgNPs-AV invitro for 72 hrs. In addition to AgNPs-AV inhibited the growth of the most important human skin pathogens (candida albicans, Pseudomonas aeruginosa and Staphylococcus aureus). The largest inhibition zone was observed for candida albicans. This method for synthesis is very fast, produces spherical colloidal silver nanoparticles having an excellent antioxidant activity, high anticancer therapeutic index and very promising antibacterial activity. This greenly synthesized nano-formulation has a great potential to be explored in many different aspects. پرونده مقاله -
دسترسی آزاد مقاله
4 - Facile Synthesis and Investigation of Flower like p-NiO/n-ZnO as Efficient Photocatalyst for Degradation of Erythromycin under Sunlight
Sajad Khamani Mohammad Hossein Ghorbani Leila Torkian Reza Fazaeli Zahra KhodadadiConventional wastewater treatment is not able to effectively removal drugs such as antibiotics, so it is important to remove the remaining antibiotics from the environment. In this research, Zinc oxide (ZnO), nickel oxide (NiO) and p-NiO/n-ZnO heterostructure were synth چکیده کاملConventional wastewater treatment is not able to effectively removal drugs such as antibiotics, so it is important to remove the remaining antibiotics from the environment. In this research, Zinc oxide (ZnO), nickel oxide (NiO) and p-NiO/n-ZnO heterostructure were synthesized. Then, prepared samples were characterized by several techniques. The photocatalytic degradation of erythromycin from aqueous solutions was studied by photocatalysts synthesized under sunlight. Design of Experimental (DOE) was used to evaluate the effective parameters in the degradation process of erythromycin. The effects of pH, time (min), photocatalytic mass (g) and erythromycin concentration (mg/L) were studied. Using Design Expert 7 software, the highest degradation efficiency of erythromycin was found 99.54%, under optimum conditions at pH 3.07, time 101.14 (min), photocatalyst mass 0.13 (g) and erythromycin concentration 41.04 (mg/L). Isothermal studies have shown that the Fritz-Schlander isotherm with the least error with the experimental data of p-NiO/n-ZnO (5%) photocatalytic degradation are the best fit. پرونده مقاله -
دسترسی آزاد مقاله
5 - Aloe Vera gel extract and sunlight mediated synthesis of silver nanoparticles with highly effective antibacterial and anticancer activity
Noha Mohamed H.M. El-MasryIn this study, a single-step method for green synthesis of silver nanoparticles usingAloe Vera gel extract and sunlight was investigated. The Aloe Vera gel extractis composed of pectins, lignin, and hemicellulose, which can be used in thereduction of silver ions to prod چکیده کاملIn this study, a single-step method for green synthesis of silver nanoparticles usingAloe Vera gel extract and sunlight was investigated. The Aloe Vera gel extractis composed of pectins, lignin, and hemicellulose, which can be used in thereduction of silver ions to produce colloidal silver nanoparticles (AgNPs-AV). Thepreliminary preparation of silver nanoparticles was observed by an immediatecolor change to brown. The prepared silver nanoparticles were characterizedby transmission electron microscopy, Fourier transform infrared spectroscopy,dynamic light scattering, and zeta potential measurements. Additionally, thecytotoxicity and antimicrobial activity of AgNPs-AV was tested. Results indicatedthe formation of stable spherical 90±40nm with a strong absorption peak appearsbetween 400 and 500 nm. 28.7 ±0.781% of breast cancer cells survived afterincubation with AgNPs-AV invitro for 72 hrs. In addition to AgNPs-AV inhibitedthe growth of the most important human skin pathogens (candida albicans,Pseudomonas aeruginosa and Staphylococcus aureus). The largest inhibitionzone was observed for candida albicans. This method for synthesis is very fast,produces spherical colloidal silver nanoparticles having an excellent antioxidantactivity, high anticancer therapeutic index and very promising antibacterialactivity. This greenly synthesized nano-formulation has a great potential to beexplored in many different aspects. پرونده مقاله -
دسترسی آزاد مقاله
6 - Highly Porous Bi(III) Modified Rice Husk Silica Photocatalyst for the Photocatalytic Removal of Cationic Methylene Blue
Normawati Jasni Anwar Iqbal N. H. H Abu Bakar Dede Heri Yuli Yanto Hor Jia Yi Noor Haida Mohd Kaus Mohd Norazmi Ahmad Sri MulijaniA series of bismuth-silicate photocatalysts were synthesized via the sol-gel method for photodegradation of methylene blue (MB) under sunlight irradiation, utilizing rice husk ash as a silica precursor. The scanning electron microscopy/energy dispersive X-ray (SEM/EDX) چکیده کاملA series of bismuth-silicate photocatalysts were synthesized via the sol-gel method for photodegradation of methylene blue (MB) under sunlight irradiation, utilizing rice husk ash as a silica precursor. The scanning electron microscopy/energy dispersive X-ray (SEM/EDX) analysis detected Bi content in 3-10 wt% range. Furthermore, it can be seen that the porosity decreased as the Bi concentration increased. The N2 adsorption-desorption analysis indicates the presence of mesopores with an average diameter of 297-554 Å with Brunauer–Emmett–Teller (BET) surface area of 5.6-30.5 m2/g. The photocatalyst with a Bi concentration of 4 wt% (RHSBi-A2) was the most active in the photodegradation of MB; the removal reached 90% within 4 h. The photodegradation is proposed to be driven by superoxide ( ), hydroxyl (•OH) radicals, and hole (h+) based on the valence band (VB) and conduction band (CB) potentials. The porous silica framework is proposed to act as an electron reservoir, allowing better MB adsorption and enhancing light absorption. پرونده مقاله -
دسترسی آزاد مقاله
7 - Effects of Atmospheric Changes on Reducing the Performance of Solar Panels by Particle Swarm Optimization Algorithm
Shahrokh Jalili Elay MehrpourazariSolar energy as the most important source of renewable energy is an important alternative to fossil and non-renewable energies. This energy source, in addition to many benefits, is also very sensitive to environmental changes. Atmospheric changes can be expressed as a m چکیده کاملSolar energy as the most important source of renewable energy is an important alternative to fossil and non-renewable energies. This energy source, in addition to many benefits, is also very sensitive to environmental changes. Atmospheric changes can be expressed as a main factor in reducing the performance of Solar Cells. In this study, by using particle swarm optimization algorithm, the amount of solar energy dissipation in solar panels affected by atmospheric changes (the most important factor), including radiation, precipitation and wind, has been investigated. For this purpose, a comparative method with the base state has been used and the amount of difference between the two results in the solar cells is measured. In this regard, created solar cells in Maragheh city are considered as the basis for analysis. Based on the results of measurements and simulation by particle swarm optimization algorithm, the maximum atmospheric effect is related to the variations curve of the precipitation and then the variations curve of the radiation (shadow). Also, wind changes have had the least impact on reducing the performance of solar panels in the area. پرونده مقاله -
دسترسی آزاد مقاله
8 - Evaluation of energy loss in solar panels in day-night circulation by MATLAB
Elay Mehrpourazari Shahrokh JaliliFossil fuels as known as non-renewal sources which are mostly affect environment very adverse were extraction operations are costly which that the new-energy sources application is widely considered. The solar panels are the most effective devices for receive and contro چکیده کاملFossil fuels as known as non-renewal sources which are mostly affect environment very adverse were extraction operations are costly which that the new-energy sources application is widely considered. The solar panels are the most effective devices for receive and control solar energy which focused on this study. The most important issue in solar cells is the problem of energy dissipation during day-night cycles. For this purpose, the particle swarm optimization (PSO) and perturb & observe (P&O) algorithms are utilized for evaluate the energy dissipation amounts were implemented in MATLAB. As basic of the analysis, Maragheh city's solar cells site is conducted to assessments. According to the results, the P&O method as well as PSO is suited for single-element solar radiation and for radiation/time response at tracking of maximum power point tracking (MPPT) were related to the day-night cycles. پرونده مقاله -
دسترسی آزاد مقاله
9 - Effects of Location in the Tree Canopy on Some Quality Characteristics of Fresh Pistachio Fruit
Behzad Saffari HamidReza AkhavanFresh pistachio fruit cv. Kalleghochi was harvested from the exterior and interior parts of the tree canopy in four geographical directions. The fruit position in exterior and interior parts of the tree canopy has a significant influence on the number of nuts per ounce, چکیده کاملFresh pistachio fruit cv. Kalleghochi was harvested from the exterior and interior parts of the tree canopy in four geographical directions. The fruit position in exterior and interior parts of the tree canopy has a significant influence on the number of nuts per ounce, pistachio splitting, hull weight, shell weight, kernel weight, colour indices and total anthocyanin content. Results indicated that the number of nuts per ounce, pistachio splitting, kernel weight, red skin colour (a*) and total anthocyanin content of outer-canopy fruits were higher than the fruits from inner-canopy fruits. Pistachio splitting was highest (98.6%) in outer-canopy in comparison to inner-canopy (50.3%) fruits. Results also indicated that the sunlight exposure increased red colour development and accumulation of anthocyanins. The total anthocyanin contents of hull in outer-canopy were 91% higher than those in inner-canopy fruits. Therefore, phenolic accumulation in pistachio hull maybe takenintoconsiderationas an important source of functional compounds in food systems with health promoting effects and antimicrobial activity. Results of this study suggest that the fruit position within the canopy is an important factor in determining physicochemical characteristics of pistachio fruit. پرونده مقاله
سکوی نشر دانش
سند یا سکوی نشر دانش ،سامانه ای جهت مدیریت حوزه علمی و پژوهشی نشریات دانشگاه آزاد می باشد
پیوندهای سایت
مراکز مرتبط
پشتیبانی
صفحات رسمی
حقوق این وب‌سایت متعلق به سامانه مدیریت نشریات دانشگاه آزاد اسلامی است.
حق نشر © 1403-1400