Read by QxMD icon Read


A H Sabry, W Z W Hasan, M Z A Ab Kadir, M A M Radzi, S Shafie
The power system always has several variations in its profile due to random load changes or environmental effects such as device switching effects when generating further transients. Thus, an accurate mathematical model is important because most system parameters vary with time. Curve modeling of power generation is a significant tool for evaluating system performance, monitoring and forecasting. Several numerical techniques compete to fit the curves of empirical data such as wind, solar, and demand power rates...
2018: PloS One
Xiaoyi Wang, Yulong Liao, Huaiwu Zhang, Tianlong Wen, Dainan Zhang, Yuanxun Li, Mingzhen Liu, Faming Li, Qiye Wen, Zhiyong Zhong, Xingtian Yin
Fe3O4 nanoplates were fabricated by an anodic oxidation process and a subsequent water assisted crystallization process at low temperature, which was found to be very efficient and environmentally friendly. The as-prepared Fe3O4 nanoplates have hexagonal outlines with a thickness of about 20 nm. Tremendous grooves were distributed on the entire surfaces of the nanoplates, making the two-dimension nanoplates have a unique 3D morphology. Transmission electron microscopy results confirmed that the single-crystalline nature of the nanoplates was well maintained...
January 19, 2018: ACS Applied Materials & Interfaces
Chao Yang, Xin Xi, Zhi-Guo Yu, Haicheng Cao, Jing Li, Shan Lin, Zhanhong Ma, Lixia Zhao
Based on the laterally porous GaN, we designed and fabricated composite GaN porous structures with both well-ordered lateral and vertical holes. Compared to the plane GaN, the composite porous GaN structure with the combination of the vertical holes can help to reduce the UV reflectance, and increase the saturation photocurrent density during the water splitting by a factor of ~4.5. Furthermore, we investigated the underlying mechanism for the enhancement of the water splitting performance using FDTD method...
January 19, 2018: ACS Applied Materials & Interfaces
Raffaella Micillo, Mariagrazia Iacomino, Marco Perfetti, Lucia Panzella, Kenzo Koike, Gerardino D'Errico, Marco d'Ischia, Alessandra Napolitano
To inquire into the role of the carboxyl group as determinant of the properties of 5,6-dihydroxyindole melanins, melanins from aerial oxidation of 5,6-dihydroxyindole (DHICA) and its methyl ester MeDHICA were comparatively tested for their antioxidant activity. MALDI MS spectrometry analysis of MeDHICA melanin provided evidence for a collection of intact oligomers. EPR analysis showed g-values almost identical and signal amplitudes (ΔB) comparable to those of DHICA melanin, but spin density was one order of magnitude higher, with a different response to pH changes...
January 19, 2018: Pigment Cell & Melanoma Research
Yun Lin, Yang Bai, Yanjun Fang, Zhaolai Chen, Shuang Yang, Xiaopeng Zheng, Shi Tang, Ye Liu, Jingjing Zhao, Jinsong Huang
Two-dimensional (2D) perovskites have been shown to be more stable than their three-dimensional (3D) counterparts due to the protection of the organic ligands. Herein a method is introduced to form 2D/3D stacking structures by the reaction of 3D perovskite with n-Butylamine (BA). Different from regular treatment with n-Butylammonium iodide (BAI) where 2D perovskite with various layers form, the reaction of BA with MAPbI3 only produce (BA)2PbI4, which has better protection due to more organic ligands in (BA)2PbI4 than the mixture of 2D perovskites...
January 19, 2018: Journal of Physical Chemistry Letters
Zhifeng Jiang, Weiming Wan, Huaming Li, Shouqi Yuan, Huijun Zhao, Po Keung Wong
The challenge in the artificial photosynthesis of fossil resources from CO2 by utilizing solar energy is to achieve stable photocatalysts with effective CO2 adsorption capacity and high charge-separation efficiency. A hierarchical direct Z-scheme system consisting of urchin-like hematite and carbon nitride provides an enhanced photocatalytic activity of reduction of CO2 to CO, yielding a CO evolution rate of 27.2 µmol g-1 h-1 without cocatalyst and sacrifice reagent, which is >2.2 times higher than that produced by g-C3 N4 alone (10...
January 19, 2018: Advanced Materials
Haejun Yu, Hye-In Yeom, Jong Woo Lee, Kisu Lee, Doyk Hwang, Juyoung Yun, Jaehoon Ryu, Jungsup Lee, Sohyeon Bae, Seong Keun Kim, Jyongsik Jang
The power conversion efficiency (PCE) of perovskite solar cells (PSCs) has now exceeded 20%; thus, research focus has shifted to establishing the foundations for commercialization. One of the pivotal themes is to curtail the overall fabrication time, to reduce unit cost, and mass-produce PSCs. Additionally, energy dissipation during the thermal annealing (TA) stage must be minimized by realizing a genuine low-temperature (LT) process. Here, tin oxide (SnO2 ) thin films (TFs) are formulated at extremely high speed, within 5 min, under an almost room-temperature environment (<50 °C), using atmospheric Ar/O2 plasma energy (P-SnO2 ) and are applied as an electron transport layer of a "n-i-p"-type planar PSC...
January 19, 2018: Advanced Materials
Jing Cao, Binghui Wu, Ruihao Chen, Youyunqi Wu, Yong Hui, Bing-Wei Mao, Nanfeng Zheng
The power conversion efficiency of perovskite solar cells (PSCs) has ascended from 3.8% to 22.1% in recent years. ZnO has been well-documented as an excellent electron-transport material. However, the poor chemical compatibility between ZnO and organo-metal halide perovskite makes it highly challenging to obtain highly efficient and stable PSCs using ZnO as the electron-transport layer. It is demonstrated in this work that the surface passivation of ZnO by a thin layer of MgO and protonated ethanolamine (EA) readily makes ZnO as a very promising electron-transporting material for creating hysteresis-free, efficient, and stable PSCs...
January 19, 2018: Advanced Materials
Hongcai He, Zhuolin Jiang, Zhaoling He, Tao Liu, Enzhu Li, Bao-Wen Li
An excellent ternary composite photocatalyst consisting of silver orthophosphate (Ag3PO4), attapulgite (ATP), and TiO2 was synthesized, in which heterojunction was formed between dissimilar semiconductors to promote the separation of photo-generated charges. The ATP/TiO2/Ag3PO4 composite was characterized by SEM, XRD, and UV-vis diffuse reflectance spectroscopy. The co-deposition of Ag3PO4 and TiO2 nanoparticles onto the surface of ATP forms a lath-particle structure. Compared with composite photocatalysts consisting of two phases, ATP/TiO2/Ag3PO4 ternary composite exhibits greatly improved photocatalytic activity for degradation of rhodamine B under simulated solar irradiation...
January 18, 2018: Nanoscale Research Letters
Queenie H S Chan, Michael E Zolensky, Yoko Kebukawa, Marc Fries, Motoo Ito, Andrew Steele, Zia Rahman, Aiko Nakato, A L David Kilcoyne, Hiroki Suga, Yoshio Takahashi, Yasuo Takeichi, Kazuhiko Mase
Direct evidence of complex prebiotic chemistry from a water-rich world in the outer solar system is provided by the 4.5-billion-year-old halite crystals hosted in the Zag and Monahans (1998) meteorites. This study offers the first comprehensive organic analysis of the soluble and insoluble organic compounds found in the millimeter-sized halite crystals containing brine inclusions and sheds light on the nature and activity of aqueous fluids on a primitive parent body. Associated with these trapped brines are organic compounds exhibiting wide chemical variations representing organic precursors, intermediates, and reaction products that make up life's precursor molecules such as amino acids...
January 2018: Science Advances
Jae Choul Yu, Ji A Hong, Eui Dae Jung, Da Bin Kim, Soo-Min Baek, Sukbin Lee, Shinuk Cho, Sung Soo Park, Kyoung Jin Choi, Myoung Hoon Song
The beneficial use of a hole transport layer (HTL) as a substitution for poly(3,4-ethlyenedioxythiophene): polystyrene sulfonate (PEDOT:PSS) is regarded as one of the most important approaches for improving the stability and efficiency of inverted perovskite solar cells. Here, we demonstrate highly efficient and stable inverted perovskite solar cells by applying a GO-doped PEDOT:PSS (PEDOT:GO) film as an HTL. The high performance of this solar cell stems from the excellent optical and electrical properties of the PEDOT:GO film, including a higher electrical conductivity, a higher work function related to the reduced contact barrier between the perovskite layer and the PEDOT:GO layer, enhanced crystallinity of the perovskite crystal, and suppressed leakage current...
January 18, 2018: Scientific Reports
Antonio Genova, Erwan Mazarico, Sander Goossens, Frank G Lemoine, Gregory A Neumann, David E Smith, Maria T Zuber
The NASA MESSENGER mission explored the innermost planet of the solar system and obtained a rich data set of range measurements for the determination of Mercury's ephemeris. Here we use these precise data collected over 7 years to estimate parameters related to general relativity and the evolution of the Sun. These results confirm the validity of the strong equivalence principle with a significantly refined uncertainty of the Nordtvedt parameter η = (-6.6 ± 7.2) × 10-5. By assuming a metric theory of gravitation, we retrieved the post-Newtonian parameter β = 1 + (-1...
January 18, 2018: Nature Communications
S Matthew Menke, Alexandre Cheminal, Patrick Conaghan, Niva A Ran, Neil C Greehnam, Guillermo C Bazan, Thuc-Quyen Nguyen, Akshay Rao, Richard H Friend
Donor-acceptor organic solar cells often show low open-circuit voltages (V OC) relative to their optical energy gap (E g) that limit power conversion efficiencies to ~12%. This energy loss is partly attributed to the offset between E g and that of intermolecular charge transfer (CT) states at the donor-acceptor interface. Here we study charge generation occurring in PIPCP:PC61BM, a system with a very low driving energy for initial charge separation (E g-E CT ~ 50 meV) and a high internal quantum efficiency (η IQE ~ 80%)...
January 18, 2018: Nature Communications
Zhiyuan Xu, Jingjing Shi, Muhammad Sohail Haroone, Wenpeng Chen, Shufang Zheng, Jun Lu
Due to the superiority of metal-doped ZnO compared to TiO2, the Zn-M (M = Al3+, Ga3+, Cr3+, Ti4+, Ce4+) mixed metal oxide solid solutions have been extensively studied for photocatalytic and photovoltaic applications. In this work, a systematic research has proceeded for the preparation of a zinc-aluminum oxide semiconductor as a photoanode for the dye-sensitized solar cells (DSSCs) by a simple pyrolysis route with the Zn-Al layered double hydroxide (LDH) as a precursor. The Zn-Al oxide solid solution has been applied for DSSCs as an electron acceptor, which is used to study the influence of different Al content and sintering temperature on the device efficiency...
January 10, 2018: Journal of Colloid and Interface Science
Roman J Dial, Gerard Q Ganey, S McKenzie Skiles
Red-colored secondary pigments in glacier algae play an adaptive role in melting snow and ice. We advance this hypothesis using a model of color-based absorption of irradiance, an experiment with colored particles in snow, and the natural history of glacier algae. Carotenoids and phenols-astaxanthin in snow-algae and purpurogallin in ice-algae-shield photosynthetic apparatus by absorbing over-abundant visible wavelengths, then dissipating the excess radiant energy as heat. This heat melts proximal ice crystals, providing liquid-water in a 0°C environment and freeing-up nutrients bound in frozen water...
January 15, 2018: FEMS Microbiology Ecology
Prabhakarn Arunachalam, Maged N Shaddad, Mohamed A Ghanem, Abdullah M Al-Mayouf, Mark T Weller
Photoanodes fabricated by the electrophoretic deposition of a thermally prepared zinc tantalum oxynitride (ZnTaO₂N) catalyst onto indium tin oxide (ITO) substrates show photoactivation for the oxygen evolution reaction (OER) in alkaline solutions. The photoactivity of the OER is further boosted by the photodeposition of cobalt phosphate (CoPi) layers onto the surface of the ZnTaO₂N photoanodes. Structural, morphological, and photoelectrochemical (PEC) properties of the modified ZnTaO₂N photoanodes are studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet visible (UV-Vis) diffuse reflectance spectroscopy, and electrochemical techniques...
January 18, 2018: Nanomaterials
Miao Xie, Fu-Quan Bai, Jinjian Wang, Yue-Qing Zheng, Zhenyang Lin
Dye sensitizers play an important role in dye-sensitized solar cells (DSSCs). As a promising strategy for the design of novel porphyrin sensitizers, the asymmetric modification of the porphyrin ring to meso-link porphyrin sensitizer has emerged in recent years, which can improve the light-harvesting properties and enhance the electron distribution. In this work, in order to reveal the essence of the effect of unsymmetrical substitution on the performance of β-link porphyrin dyes in DSSCs, four kinds of common β-link porphyrin dyes with different structures are calculated by using density functional theory (DFT) and time-dependent density functional theory (TD-DFT)...
January 18, 2018: Physical Chemistry Chemical Physics: PCCP
Min Wu, Juan Li, Ruqin Zhang, Xia Tian, Zhaoxiang Han, Xiaoqing Lu, Kunpeng Guo, Zhike Liu, Zhongqiang Wang
Two spiroannulated molecular structures with dithiafulvenyl units functionalized at the 2,2',7,7'- (SFX-DTF1) and 2,3',6,'7- (SFX-DTF2) positions of a spiro[fluorene-9,9'-xanthene] core were synthesized. Studies revealed the hole mobility was significantly influenced by the dithiafulvenyl functionalized positions in the molecular structure. To explore their primary applications as hole-transporting materials in perovskite solar cells, SFX-DTF1-based devices exhibited a power conversion efficiency of 10.67% without the use of p-type dopants, yielding good air stability...
January 18, 2018: Organic Letters
Kifle Z Aregahegn, Michael J Ezell, Barbara J Finlayson-Pitts
The environmental fates of nitenpyram (NPM), a widely used neonicotinoid insecticide, are not well known. A thin solid film of NPM deposited on a germanium attenuated total reflectance (ATR) crystal was exposed to radiation from a low-pressure mercury lamp at 254 nm, or from broadband low pressure mercury photolysis lamps centered at 350 or 313 nm. The loss during photolysis was followed in time using FTIR. The photolysis quantum yields (), defined as the number of NPM molecules lost per photon absorbed, were determined to be (9...
January 18, 2018: Environmental Science & Technology
Silvia Mariotti, Oliver S Hutter, Laurie J Phillips, Peter J Yates, Biswajit Kundu, Ken Durose
In this manuscript, the inorganic perovskite CsPbI2Br is investigated as a photovoltaic material that offers higher stability than the organic-inorganic hybrid perovskite materials. It is demonstrated that CsPbI2Br does not irreversibly degrade to its component salts as in the case of methylammonium lead iodide but instead is induced (by water vapor) to transform from its metastable brown cubic (1.92 eV band gap) phase to a yellow phase having a higher band gap (2.85 eV). This is easily reversed by heating to 350 °C in a dry environment...
January 18, 2018: ACS Applied Materials & Interfaces
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"