Lepidium sativum (LS) is an annual plant that has been used for the treatment of many ailments. The ethanol extracts of pinnately-lobed (PL), pinnately-compound (PC), and pinnately-veined (PV) leaves ...of LS were examined for their total polyphenol and flavonoid contents, and their phenolic acid (namely caffeic acid (CA), p-coumaric acid (PA), and ferulic acid (FA)) contents were determined using reverse-phase high-performance liquid chromatography-photodiode array (HPLC/PDA) analysis. Among the three leaf types, the highest average total polyphenol content was found in PV (79.87 mg GAE/g extract), whereas PC showed the highest average total flavonoid content (53.35 mg QE/g extract). According to the HPLC/PDA results, PV exhibited a high amount of CA (78.60 µg/g extract) and FA (1,722.85 µg/g extract), whereas a high content of PA (258.72 µg/g extract) was detected in PC. Higher amounts of the phytochemical compounds PV and PC might be indicative of their superior biological activities compared to PL. To the best of our knowledge, this study is the first to quantify and compare the total polyphenol, flavonoid, and phenolic acid contents in three different leaf types of LS. KCI Citation Count: 0
We have fabricated as-grown ZnO nanorods (NRs) and carbon-assisted NR arrays on semi-insulating (100)-oriented Si substrates. We compared the structural and luminescent properties of them. ...High-resolution transmission microscopy, field emission scanning electron microscopy, x-ray diffraction and energy-dispersive x-ray revealed that the as-grown ZnO NRs and carbon-assisted ZnO NRs were single crystals with a hexagonal wurtzite structure, and grew with a c-axis orientation perpendicular to the Si substrate. These measurements show that the carbon-assisted ZnO NRs were better synthesized vertically on an Si substrate compared to the as-grown ZnO NRs. Photoluminescence measurements showed that luminescence intensity of the carbon-assisted ZnO NRs was enhanced compared to the as-grown ZnO NRs. The enhanced luminescence intensity of the carbon-assisted ZnO demonstrates the possible improvement in the performance of photovoltaic nanodevices based on ZnO-like materials. This method can be applied to the fabrication of well-aligned ZnO NRs used widely in optoelectronic devices.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
This study aimed to identify the phytochemical constituents of Lactuca serriola leaves and perform quantitative analysis of the methanol (MeOH) extract of L. serriola, L. indica, L. raddeana, L. ...sativa, and L. triangulata. Six compounds were isolated from the MeOH extracts of L. serriola using open column chromatography and identified as protocatechuic acid (1), caffeic acid (2), cynaroside (3), apigenin 7-glucuronide (4), luteolin (5), and apigenin (6) using 1 H-, 13 C-nuclear magnetic resonance, and mass spectrometry. Quantitative analysis of the six compounds was performed on the MeOH extract of Lactuca species using high-performance liquid chromatography (HPLC) and an ultraviolet (UV). A reverse-phased column was used, and the UV absorbance was set to 280 nm. The contents of compounds 2 and 3 were the highest (1.58 and 2.64 mg/g ext., respectively) in L. serriola extracts. However, compounds 4 and 6 were higher (1.46 and 0.40 mg/g ext., respectively) in L. triangulata. These results provide quantitative data for the application of Lactuca species in the pharmaceutical and functional food industries.
We show that low field magnetoelectric (ME) properties of helimagnets Ba0.5Sr1.5Zn2(Fe1-xAlx)12O22 can be efficiently tailored by the Al-substitution level. As x increases, the critical magnetic ...field for switching electric polarization is systematically reduced from approximately 1 T down to approximately 1 mT, and the ME susceptibility is greatly enhanced to reach a giant value of 2.0x10{4} ps/m at an optimum x=0.08. We find that control of the nontrivial orbital moment in the octahedral Fe sites through the Al substitution is crucial for fine-tuning the magnetic anisotropy and obtaining the conspicuously improved ME characteristics.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
This study aimed to investigate the effect of suppressing transpiration on the physiological characteristics of trees and identify suitable indicators to assess tree vitality. Three seedlings of ...Zelkova serrata were used: a control, a unit treated on the upper sides of the leaves (TU), and a unit treated on double sides of the leaves (TD). Changes in photosynthetic rate, transpiration rate, sap velocity, and bark temperature following the suppression of transpiration were measured. The transpiration rate and other physiological characteristics of TU were not significantly different from those of the control except for photosynthetic rate. However, TD showed a significantly lower photosynthetic rate, transpiration rate, and sap velocity compared to the control. The bark temperature of TD was not significantly higher than that of the control and TU. Our findings indicate that photosynthetic rate and sap velocity were positively correlated with transpiration rate, whereas bark temperature was negatively correlated. Furthermore, photosynthetic rate showed the most significant linear relationship with transpiration rate, suggesting the photosynthetic rate is a suitable physiological indicator to evaluate the vitality of Z. serrata.
Layered two‐dimensional materials have attracted much attention because of their interesting physical properties for nanoelectronic and optoelectronic applications. In this work, Gallium Selenide ...(GaSe) nanosheets are exfoliated by the shear exfoliation method to produce dispersion of various GaSe nanosheets. The morphological features are examined using Raman Spectroscopy and Atomic Force Microscopy and the optical band gap was estimated to be 2.1 eV using Tauc's Plot. The heterojunction comprising GaSe nanosheets and n‐type silicon was fabricated which exhibits rectifying behavior and also prominent photoresponse was observed. The obtained results suggest the potential of shear exfoliated GaSe nanosheets for photodetection and next‐generation optoelectronics.
Gallium selenide (GaSe) nanosheets are exfoliated by the shear exfoliation method to produce dispersion of various GaSe nanosheets. The morphological features are examined using Raman spectroscopy and atomic force microscopy and the optical band gap was estimated to be 2.1 eV using Tauc's plot. The heterojunction comprising GaSe nanosheets and n‐type silicon is fabricated which exhibits rectifying behavior and also prominent photoresponse is observed. The obtained results suggest the potential of shear exfoliated GaSe nanosheets for photodetection and next‐generation optoelectronics.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Four compounds were isolated from Salvia plebeia aerial parts. Silica gel open column chromatography with a gradient elution system was used to isolate and purify these compounds. Nuclear magnetic ...resonance spectroscopy and mass spectroscopy were used for structural elucidation and identification, while electronic circular dichroism was used to confirm the absolute configuration. The structures were determined to be β- sitosterol (1), (–)-1S,5S,8S,10R-1-acetoxy-8-hydroxy-2-oxoeudesman- 3,7(11)-dien-8,12-olide (2), ursolic acid (3), and N-methylhydroxylamine (4). Compounds 2 and 4 were isolated for the first time from this plant. Compound 2 was quantitatively analyzed via HPLC/UV. The results showed that the methanol extract of S.
plebeia had a higher content of compound 2 (1.20 mg/g) than the ethanol extract (0.55 mg/g). This study could be used as a preliminary step in conducting HPLC/UV analysis of sesquiterpenoids in S. plebeia extract to assess their bioavailability and potency. KCI Citation Count: 0
In order to fundamentally understand the secondary hydriding mechanism of zirconium alloy cladding, the reaction of commercial Zircaloy-4 tubes with hydrogen and steam mixture was studied using a ...thermo-gravimetric analyser with two variables, H2/H2O ratio and temperature. Phenomenological analysis revealed that in the steam starvation condition, i.e., when the H2/H2O ratio is greater than 104, hydriding is the dominant reaction and the weight gain increases linearly after a short incubation time. On the other hand, when the gas ratio is 5 × 102 or 103, both hydriding and oxidation reactions take place simultaneously, leading to three distinct regimes: primary hydriding, enhanced oxidation, and massive hydriding. Microstructural changes of oxide demonstrate that when the weight gain exceeds a certain critical value, massive hydriding takes place due to the significant localized crack development within the oxide, which possibly simulates the secondary hydriding failure in a defective fuel operation. This study reveals that the steam starvation condition above the critical H2/H2O ratio is only a necessary condition for the secondary hydriding failure and, as a sufficient condition, oxide needs to grow sufficiently to reach the critical thickness that produces substantial crack development. In other words, in a real defective fuel operation incident, the secondary failure is initiated only when both steam starvation and oxide degradation conditions are simultaneously met. Therefore, it is concluded that the indispensable time for the critical oxide growth primarily determines the triggering time of massive hydriding failure.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
•Estimation method of the fundamental frequency in the EOL fuel assembly is suggested.•Bending energy is used to identify the fundamental frequency.•Prediction error can be minimized when the ...deflection shape resembles the first mode shape.•Test examples show that the suggested method is reliable.
This paper develops a methodology to predict the End-Of-Life (EOL) fundamental frequency of a Pressurized Water Reactor (PWR) fuel assembly using lateral bending test data. Bending energy, developed from the lateral bending tests, is utilized to predict the first mode natural frequency. It is shown that the estimation provides reasonable results when the deflected shape is close to the first mode shape. One can evaluate the structural integrity against earthquakes by utilizing a simulation tool that uses the physical information of the fuel assembly. One of the important pieces of information for the simulation is the first natural frequency of the fuel assembly, because the dominant frequency components of the reactor motion are close to the fundamental frequency of the fuel assembly. When the EOL information is unavailable, the unknown EOL fundamental frequency can be identified directly through tests. However, it is almost impossible to build a specific fuel assembly when the fuel assembly is no longer produced. Therefore, this paper suggests using the load-to-deflection curve from the static bending test to predict the fundamental frequency of the EOL fuel assembly. Estimation errors are also discussed, and it is shown that the errors can be minimized using the bending energy considering the deflected bending shape that is the most similar to the fundamental mode shape. Two test examples are discussed, and the results show that the suggested method provides reliable results.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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