Toward fully organic rechargeable charge storage devices based on carbon electrodes grafted with redox molecules

Activated carbon powders modified with naphthalimide and 2,2,6,6-tetramethylpiperidine-N-oxyl were assembled into a hybrid electrochemical capacitor containing an organic electrolyte. The fully organic rechargeable system demonstrated an increase in specific capacitance up to 51%, an extended operating voltage of 2.9 V in propylene carbonate, compared to 1.9 V for the unmodified system, and a power 2.5 times higher

High-resolution regional modeling of urban moisture island: mechanisms and implications on thermal comfort

The urban moisture island (UMI) can aggravate the thermal stress due to the urban heat island (UHI) in subtropical and tropical cities. In this study, we investigated the spatiotemporal variation patterns of UMI in Hong Kong, a subtropical coastal city, using the fine-resolution mesoscale Weather Research and Forecasting (WRF) model by integrating local climate zone (LCZ) maps based on the World Urban Database and Access Portal Tools (WUDAPT). Our results show that at regional scale, the UMI phenomenon tends to occur in coastal areas, possibly owing to rich moisture sources from sea breeze and inhibited moisture penetration due to barrier effects of mountains. Specifically, an all-day UMI effect was found in coastal low-density low-rise areas (LCZ5&8&10), while a nocturnal UMI effect and a daytime urban dry island (UDI) effect were found in coastal high-density high-rise areas (LCZ1&2). The UDI effect at daytime can be attributed to strong vertical moisture convection associated with intensive surface sensible heat fluxes in a strongly mixed urban boundary layer (UBL). The UMI effect at night can be attributed to blocked ventilation aisle, inhibited dewfall due to UHI, and weakened upward motion in a stable UBL. On the other hand, UMI can increase regional heat risks with additional 37.5% neighbourhoods in Extreme caution level and additional 6.1% neighbourhoods in Danger level. In addition, the impact of UMI on human thermal stress was found to be dominant at daytime in coastal low-density low-rise areas (LCZ5&8&10) and at nighttime in coastal high-density high-rise areas (LCZ1&2)

Modifying of LiNi0.8Co0.2O2 Cathode Material by Chemical Vapor Deposition Coating to Improve Thermal Stability

In this paper, we tried to find answers to safety problems due to use of transition metal oxide as positive electrodes in the lithium ion batteries. The exothermic reaction at high temperature induced by the contact between positive electrode in the charged state, such as LiNi0.8Co0.2O2 and the liquid electrolyte solution based of LiPF6 (EC, DMC) is reduced by formation of ceramic oxide. Al2O3 – and ZnO-coated are synthesized on the surface of LiNi0.8Co0.2O2 particles by chemical vapor deposition. The influences of deposit on the properties of starting material, in particular the thermal stability, are characterized by using, X-ray diffraction, electrochemical measurements and differential scanning calorimeter (DSC). Al2O3-coated sample show fading specific capacity during the first cycle. However, after several cycles a retention capacity is observed. ZnO-coated LiNi0.8Co0.2O2 is inactive electrochemically as shown by X-rays diffraction pattern by the existence of two phases. With regard to DSC analysis in Al2O3-coated, one observe about 35% of reduction of heat flow during the exothermic reaction. The CVD method must be improved to obtain interesting results with regard to the electrochemical performances of treated material. Keywords: lithium-ion batteries, CVD coating; alumina, layered cathode; electrochemistry, X-ray diffraction Thermal stability

Hyperproliferation and Dysregulation ofIL-4 Expression in NF-ATp-Deficient Mice

AbstractNF-ATp is a member of a family of genes that encodes the cytoplasmic component of the nuclear factor of activated T cells (NF-AT). In this study, we show that mice with a null mutation in the NF-ATp gene have splenomegaly with hyperproliferation of both B and T cells. They also display early defects in the transcription of multiple genes encoding cytokines and cell surface receptors, including CD40L and FasL. A striking defect in early IL-4 production was observed after ligation of the TCR complex by treatment with anti-CD3 in vivo. The transcription of other cytokines including IL-13, GM–CSF, and TNFα was also affected, though to a lesser degree. Interestingly, the cytokines IL-2 and IFNγ were minimally affected. Despite this early defect in IL-4 transcription, Th2 development was actually enhanced at later timepoints as evidenced by increased IL-4 production and IgE levels in situations that favor the formation of Th2 cells both in vitro and in vivo. These data suggest that NF-ATp may be involved in cell growth, and that it is important for the balanced transcription of the IL-4 gene during the course of an immune response.BDY

Can we use local climate zones for predicting malaria prevalence across sub-Saharan African cities?

Malaria burden is increasing in sub-Saharan cities because of rapid and uncontrolled urbanization. Yet very few studies have studied the interactions between urban environments and malaria. Additionally, no standardized urban land-use/land-cover has been defined for urban malaria studies. Here, we demonstrate the potential of local climate zones (LCZs) for modeling malaria prevalence rate (PfPR2-10) and studying malaria prevalence in urban settings across nine sub-Saharan African cities. Using a random forest classification algorithm over a set of 365 malaria surveys we: (i) identify a suitable set of covariates derived from open-source earth observations; and (ii) depict the best buffer size at which to aggregate them for modeling PfPR2-10. Our results demonstrate that geographical models can learn from LCZ over a set of cities and be transferred over a city of choice that has few or no malaria surveys. In particular, we find that urban areas systematically have lower PfPR2-10 (5%-30%) than rural areas (15%-40%). The PfPR2-10 urban-to-rural gradient is dependent on the climatic environment in which the city is located. Further, LCZs show that more open urban environments located close to wetlands have higher PfPR2-10. Informal settlements - represented by the LCZ 7 (lightweight lowrise) - have higher malaria prevalence than other densely built-up residential areas with a mean prevalence of 11.11%. Overall, we suggest the applicability of LCZs for more exploratory modeling in urban malaria studies. © 2020 The Author(s). Published by IOP Publishing Ltd.info:eu-repo/semantics/publishe

Composite Electrodes for Electrochemical Supercapacitors

Manganese dioxide nanofibers with length ranged from 0.1 to 1 μm and a diameter of about 4–6 nm were prepared by a chemical precipitation method. Composite electrodes for electrochemical supercapacitors were fabricated by impregnation of the manganese dioxide nanofibers and multiwalled carbon nanotubes (MWCNT) into porous Ni plaque current collectors. Obtained composite electrodes, containing 85% of manganese dioxide and 15 mass% of MWCNT, as a conductive additive, with total mass loading of 7–15 mg cm−2, showed a capacitive behavior in 0.5-M Na2SO4 solutions. The decrease in stirring time during precipitation of the nanofibers resulted in reduced agglomeration and higher specific capacitance (SC). The highest SC of 185 F g−1 was obtained at a scan rate of 2 mV s−1 for mass loading of 7 mg cm−2. The SC decreased with increasing scan rate and increasing electrode mass

Upper Pliocene to Lower Pleistocene volcanic complexes and Upper Neogene deformation in the south-central Andes (36°30′-38°S)

The Agrio (37º51´S-70º26´W), Vilú Mallín (37º28´S-70º45´W), Trohunco (37º18´S-71º01´W), Domuyo (36º38´S-70º26´W) and Los Cardos-Centinela (37º06´S-70º52´W) volcanic complexes in Argentina are the principal Upper Pliocene to Lower Pleistocene volcanic complexes that occur in the Main Andean Cordillera east of the modern volcanic front in Chile, in the Southern Volcanic zone.Volcanic rocks from these centers along with their stratigraphic relations with nearby Neogene volcanic units provide constraints on the age and style of Neogene deformation in the modern backarc of the Southern Volcanic Zone between 36°30´ and 38°S. New and published radiometric ages and stratigraphic and structural relations show that the region was affected by a latest Miocene compressional deformation that took place between 9 and 6.8 Ma.A heterogeneous picture emerges for the younger deformation of the region which lies along the Quaternary orogenic front.The most important structures include a NNW-trending fault system that joins the Trohunco and Los Cardos-Centinela complexes and is characterized by compressive deformation, and a NE-trending extensional fault system along which the Agrio caldera, Vilú Mallín and Domuyo volcanic complexes are aligned. Overall, the backarc in this region was affected by compressional deformation in the late Miocene and subjected to tectonic collapse and transpressional deformation during the late Pliocene to Quaternary.Fil: Miranda, Fernando. Secretaría de Industria y Minería. Servicio Geológico Minero Argentino; ArgentinaFil: Folguera Telichevsky, Andres. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Geología. Laboratorio de Tectónica Andina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Leal, Pablo Rodrigo. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Geología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Naranjo, José Antonio. Servicio Nacional de Geología y Minería; ChileFil: Pesce, Abel. Secretaría de Industria y Minería. Servicio Geológico Minero Argentino; Argentin