When Bigger Is Not Greener: Ensuring the Sustainability of Power- to-Gas Hydrogen on a National Scale

As the prices of photovoltaics and wind turbines continue to decrease, more renewable electricity-generating capacity is installed globally. While this is considered an integral part of a sustainable energy future by many nations, it also poses a significant strain on current electricity grids due to the inherent output variability of renewable electricity. This work addresses the challenge of renewable electricity surplus (RES) utilization with target-scaling of centralized power-to-gas (PtG) hydrogen production. Using the Republic of Korea as a case study, due to its ambitious plan of 2030 green hydrogen production capacity of 0.97 million tons year-1, we combine predictions of future, season-averaged RES with a detailed conceptual process simulation for green H2 production via polymer electrolyte membrane (PEM) electrolysis combined with a desalination plant in six distinct scale cases (0.5-8.5 GW). It is demonstrated that at scales of 0.5 to 1.75 GW the RES is optimally utilized, and PtG hydrogen can therefore outperform conventional hydrogen production both environmentally (650-2210 Mton CO2 not emitted per year) and economically (16-30% levelized cost reduction). Beyond these scales, the PtG benefits sharply drop, and thus it is answered how much of the planned green hydrogen target can realistically be if on an industrial scale

Papilledema due to Cerebral Venous Sinus Thrombosis

The diagnosis of cerebral venous thrombosis is challenging due to a wide range of clinical manifestations. Headache is the most common presenting symptom. Papilledema is present in about 28% of patients with cerebral venous thrombosis. We report the diagnosis of sinus thrombosis in two patients with blurred vision and asymptomatic optic disc swelling

Optimal dose reduction algorithm using an attenuation-based tube current modulation method for cone-beam CT imaging.

To reduce the radiation dose given to patients, a tube current modulation (TCM) method has been widely used in diagnostic CT systems. However, the TCM method has not yet been applied to a kV-CBCT system on a LINAC machine. The purpose of this study is to investigate if a TCM method would be desirable in a kV-CBCT system for image-guided radiation therapy (IGRT) or not. We have developed an attenuation-based TCM method using prior knowledge from planning CT images of patients. The TCM method can provide optimized dose reductions without degrading image quality for kV-CBCT imaging. Here, we investigate whether or not our suggested TCM method is desirable to use in kV-CBCT systems to confirm and revise the exact position of a patient for IGRT. Patients go through diagnostic CT scans for RT planning; therefore, using information from prior CT images can enable estimations of the total X-ray attenuation through a patient's body in a CBCT setting for radiation treatment. Having this planning CT image allows to use the proposed TCM method in RT. The proposed TCM method provides a minimal amount of current for each projection, as well as total current, required to reconstruct the current modulated CBCT image with an image quality similar to that of CBCT. After applying a calculated TCM current for each projection, projection images were acquired and the current modulated CBCT image was reconstructed using a FDK algorithm. To validate the proposed approach, we used a numerical XCAT phantom and a real ATOM phantom and evaluated the performance of the proposed method via visual and quantitative image quality metrics. The organ dose due to imaging radiation was calculated in both cases and compared using the GATE simulation toolkit. As shown in the quantitative evaluation, normalized noise and SSIM values of the TCM were similar to those of conventional CBCT images. In addition, the proposed TCM method yielded comparable image quality to that of conventional CBCT images for both simulations and experimental studies as organ doses were decreased. We have successfully demonstrated the feasibility and dosimetric merit of a prototypical TCM method for kV-CBCT via simulations and experimental study. The results indicate that the proposed TCM method and overall framework can be a viable option for CBCT imaging that utilizes an optimal dose reduction without degrading image quality. Thus, this method reduces the probability for side effects due to radiation exposure

Enhancement of Field Effect Mobility Due to Surface-Mediated Molecular Ordering in Regioregular Polythiophene Thin Film Transistor

With the aim of enhancing the field-effect mobility by promoting surface-mediated two-dimensional molecular ordering in self-aligned regioregular poly(3-hexylthiophene) (P3HT) we have controlled the intermolecular interaction at the interface between P3HT and the insulator substrate by using self-assembled,.monolayers (gams) functionalized with various groups (-NH2, -OH, and -CH3)- We have found that, depending on the properties of the substrate surface, the P3HT nanocrystals adopt two different orientations -parallel and perpendicular to the insulator, substrate- which have field-effect mobilities that differ by more than a factor of 4, and that are as high as 0.28 cm(2) V-1, s(-1). This surprising increase in field-effect mobility arises in particular for the perpendicular orientation of the nanocrystals withrespect to the insulator substrate. Further, the perpendicular orientation of P3HT nanocrystals can be explained by the following factors: the unshared electron pairs of the SAM end groups, the pi-H interactions between the thienyl -backbone bearing pi-systems and the H (hydrogen) atoms of the SAM end groups, and interdigitation between the alkyl chains of P3HT and them alkyl. chains of the SAMsclose27930

The Influence of Light Wavelength on Resveratrol Content and Antioxidant Capacity in <i>Arachis hypogaeas</i> L.

The quality and intensity of light can have a huge influence on plant growth and bioactive compound production. Compared to conventional lighting, very little is known about the influence of light emitting diodes (LED) irradiation on the antioxidant and antimicrobial properties and resveratrol content of peanut sprouts. This study was aimed at understanding the effects of LED light on the growth and antioxidant capacity of peanut sprouts. The resveratrol concentration was determined by liquid chromatography–tandem mass spectrometry. Peanut sprouts grown under blue LED light exhibited a higher total resveratrol content grown than those under fluorescent light and other LED light sources. The highest total phenolic content was recorded in the case of blue LED. The 1,1-diphenyl-2-picrylhydrazyl and 2,2-azino-bis 3-ethylbenzothiazoline-6-sulfonic acid radical scavenging values of blue LED‒treated and micro-electrodeless light-treated sprouts were significantly (p Escherichia coli, Klebsiella pneumonia, and Vibrio litoralis. The present study revealed that the application of LEDs during the peanut sprouts growth improves the antioxidant activity, resveratrol concentration, and metabolite accumulation

Effect of Al incorporation on the performance and reliability of p-type metal-oxide-semiconductor field effect transistors

This study examined the performance and reliability of HfO2 gate dielectrics in p-type metal-oxide-semiconductor field effect transistors (pMOSFETs) capped with Al or Al2O3. The presence of Al capping deteriorated the pMOSFET scalability and channel mobility compared to Al2O3 capping. Al capping caused a higher rate of Al diffusion in the HfO2 dielectric layer, reducing the device performance and oxide thickness scaling. This degradation of the negative bias temperature instability of the Al-incorporated sample was attributed to decay of the interface quality rather than to a decrease in charge trapping in the bulk high-k dielectric. (C) 2012 Elsevier B.V. All rights reserved.11Nsciescopu

Bias dependence of PBTI degradation mechanism in metal-oxide-semiconductor field effect transistors with La-incorporated hafnium-based dielectric

Metal-oxide-semiconductor field effect transistors (MOSFETs) with various concentrations of La incorporated in Hf-based dielectrics were characterized to evaluate the effect of La on devices&apos; reliability. Compared with the small dependence of positive bias stress instability (PBTI) on stress bias in samples without La incorporation, significant dependence of PBTI degradation on stress bias was observed in the La-incorporated samples. HRTEM analysis and flat band voltage modulation data supported the interface dipole model, suggesting that this bias dependence of PBTI degradation in the La-incorporated samples could be explained by changes of electron tunneling mechanism due to interface dipoles.close2