697 research outputs found
Unveiling the Interplay of Structural and Electrochemical Degradation of LiNiMnCoO Cathode Material for Li-Ion Batteries
Nickel-rich layered oxides, crucial for high-energy-density Li-ion batteries, face challenges in cycle life due to intricate chemomechanical degradation. This study pioneers a comprehensive approach, integrating nano X-ray computed tomography and advanced electrochemical methods, to untangle the interplay of degradation mechanisms in complex composite electrodes. The evolution of cracking in Nickel-rich cathodes is meticulously quantified under diverse operating conditions. Surprisingly, our findings unveil that, contrary to conventional wisdom, crack formation is not the primary driver of capacity decay in Nickel-rich cathodes. Instead, the limiting factor emerges from the interplay between cycling-induced cracks and a progressively growing resistivity. Cracks, amplifying electrochemically active surfaces, foster side reactions, elevating resistance, and consequently diminishing capacity and current rate capability. This novel insight redirects attention to the dynamic resistivity growth, pinpointing operating conditions as a critical contributor. This work not only advances our understanding of Nickel-rich cathode degradation but also provides a framework for strategic mitigation strategies
Identificação e clonagem de promotores raiz-específicos de eucalipto.
A utilização de promotores tecido - específicos é uma das principais estratégias para direcionar a expres são de transgenes a determinados órgãos ou tipos celulares . Por isso, o objetivo deste trabalho foi a clonagem de promotores raiz - específicos , a partir de dados de RNA - Seq obtidos de bibliotecas de raiz, xilema e folha de eucalipto. Dois genes com padrão d e expressão preferencial em raiz foram inicialmente selecionados para isolamento da região promotora. Fragmentos de 1kb foram clonados em vetor binário pCAMBIA2301, fusionados ao gene repórter da beta - glucuronidase (GUS) , para transformação de Populus trem ula x Populus alba via Agrobacterium tumefaciens .Edição dos anais do 3º Simpósio de Bioquímica e Biotecnologia, 2013. Londrina
Manual de biossegurança em laboratórios da Embrapa Florestas.
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Proposed physiologic functions of boron in plants pertinent to animal and human metabolism.
Boron has been recognized since 1923 as an essential micronutrient element for higher plants. Over the years, many roles for boron in plants have been proposed, including functions in sugar transport, cell wall synthesis and lignification, cell wall structure, carbohydrate metabolism, RNA metabolism, respiration, indole acetic acid metabolism, phenol metabolism and membrane transport. However, the mechanism of boron involvement in each case remains unclear. Recent work has focused on two major plant-cell components: cell walls and membranes. In both, boron could play a structural role by bridging hydroxyl groups. In membranes, it could also be involved in ion transport and redox reactions by stimulating enzymes like nicotinamide adenine dinucleotide and reduced (NADH) oxidase. There is a very narrow window between the levels of boron required by and toxic to plants. The mechanisms of boron toxicity are also unknown. In nitrogen-fixing leguminous plants, foliarly applied boron causes up to a 1000% increase in the concentration of allantoic acid in leaves. In vitro studies show that boron inhibits the manganese-dependent allantoate amidohydrolase, and foliar application of manganese prior to application of boron eliminates allantoic acid accumulation in leaves. Interaction between borate and divalent cations like manganese may alter metabolic pathways, which could explain why higher concentrations of boron can be toxic to plants
Iris Yellow Spot Virus in the Netherlands: Occurence in Onion and Confirmation of Transmission by Thrips tabaci
Since its first detection in the Netherlands in 1992, Iris yellow spot virus (IYSV, genus Tospovirus) has been reported worldwide in Allium crops, in a few ornamentals and in a small number of weeds. After recent findings of IYSV in Alstroemeria and Eustoma in the Netherlands, a number of neighbouring onion fields were surveyed. In 2005 and 2006, only few infected plants were found with obvious symptoms of IYSV. In 2007, after sampling and testing small leaf samples with various types of damage, including small brown-yellow colored spots and spots with thrips feeding damage, a high percentage of plants were found with positive IYSV scores in ELISA. Infection by IYSV could be confirmed in most ELISA-positive samples by RT-PCR. Under laboratory conditions, evidence was obtained that Thrips tabaci acts as a vector for this virus. Acquisition of the IYSV from infected Datura stramonium plants resulted in virus uptake and replication in over 60% of the thrips exposed, as determined by Western blotting and immunolocalisation of the virus in the foregut, and in epithelial and midgut muscle cells using antibodies against both the viral N and NSs proteins. Successful transmission of IYSV to seedlings of Emilia sonchifolia was observed, however, only at low frequency under the laboratory conditions used
Co-designing the next generation of home energy management systems with lead-users
Home energy management systems are widely promoted as essential components of future low carbon economies. It is argued in this paper that assumptions surrounding their deployment, and the methods used to design them, emerge from discredited models of people and energy. This offers an explanation for why their field trial performance is so inconsistent. A first of a kind field trial is reported. Three eco communities took part in a comprehensive participatory design exercise as lead users. The challenge was to help users synchronise their energy use behaviours with the availability of locally generated renewable energy sources. To meet this aim, a set of highly novel Home Energy Management interfaces were co-designed and tested. Not only were the designs radically different to the norm, but they also yielded sustained user engagement over a six-month follow-up period. It is argued that user-centred design holds the key to unlocking the energy saving potential of new domestic technologies, and this study represents a bold step in that direction
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