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Soil heavy metal pollution promotes extracellular enzyme production by mediating microbial community structure during vegetation restoration of metallic tailing reservoir
No full textOrganic fertilizer amendment decreased N2O/(N2O+N2) ratio by enhancing the mutualism between bacterial and fungal denitrifiers in high nitrogen loading arable soils
No full textVolatile resistive switching characteristics of molecular beam epitaxy grown HfO2 thin films
No full textIn this work, we have explored the structure, morphology and resistive switching aspects of molecular beamepitaxy grown HfO2 thin films fabricated on highly doped p-type Si substrate at substrate temperatures of 300and 500 ◦C. Both films correspond to the monoclinic phase (P21/c) of HfO2 and exhibit single crystallinestructure with a preferred orientation along (111). The density of the HfO2 layer is found to be 9.1 and 9.2 g/cm3,whereas the root mean square roughness is 1.3 and 2.4 nm in the films grown at 300 and 500 ◦C, respectively.Both films have an average grain size of ~ 140 nm. These HfO2 films demonstrate forming free volatile resistiveswitching behavior with SET voltage of − 3.1 and − 3.6 V, along with the ON/OFF ratio of ~ 2 and ~ 4 for thefilms deposited at substrate temperatures of 300 and 500 ◦C, respectively. For the films grown at 300 ◦C and500 ◦C, the retention time is found to be 20 and 30 s, respectively. Memory device based on HfO2 film withhigher substrate temperature exhibits a better ON/OFF ratio due to higher crystallinity and the availability ofmore oxygen vacancies. A comprehensive mechanism of resistive switching is also discussed in this article,considering the transport of oxygen vacancies and the electromigration of Ag ions
Controlling the Cold-Set Gelation of Bovine Serum Albumin Protein using Alcohol and Ionic Surfactant
No full textHeating of globular protein solutions usually leads to protein denaturation and subsequent gelation at high temperatures. Under “cold gelation”, protein forms a gel at a much lower temperature than its original gelation temperature (TG), which can be achieved by modifying various physicochemical conditions such as the pH of the solution, the presence of salts, etc. In this study, we investigated the cold gelation of Bovine Serum Albumin (BSA) protein induced by ethanol and controlled by ionic surfactant, using small-angle neutron scattering (SANS), dynamic light scattering (DLS), and rheology The results show that the TG of the protein with ethanol is systematically decreased as compared to the that of pure BSA solutions (~80 ◦C), reaching ~60 ◦C at 10 wt% ethanol, ~55 ◦C at 20 wt% and finally as low as ~38 ◦C in presence of 30 wt% ethanol in the solution. Rheo-logical measurements demonstrate a significant strengthening of the gel network, with the enhancement in storage modulus (G′) from ~20 Pa at 0 wt% to ~250 Pa at 30 wt% ethanol. Structural characterization reveals an increase in fractal dimension with rising ethanol content, indicating denser and more branched gel networks. Interestingly, the addition of the anionic surfactant sodium dodecyl sulfate (SDS) inhibits the alcohol-assisted cold gelation of BSA protein, depending upon the relative amount of ethanol and SDS in solution. The results are explained based on the interplay of interactions in the protein, manipulated by the presence of alcohol, elevated temperatures, and ionic surfactant. Our study highlights the tunability of gelation pathways and offers useful inputs for controlled protein gelation in biomaterial and food industry
In situ Al2O3 atomic layer deposition on pristine (0 0 1) GaAs: interface chemistry and its implication on charge carrier recombination and Fermi level pinning
No full textCharacterisation of the N-Methyltransferase SgPsmC: Application in the Kinetic Resolution of Pyrroloindolines
No full textReappraisal of Jin's visibility through fire smoke experiment: Insights into signage visibility and the impact of ambient light
No full textJin's experiments in the 1970s contributed to fire evacuation research, but only examined relatively high ambient light levels. By replicating the Jin's experimental setup and varying ambient light level, we explore the relationship between smoke extinction coefficient, background illumination and signage emitting light intensity under low-light real-world emergency scenarios. Firstly, we confirm Jin's observation of a linear relationship between smoke extinction coefficient (sigma) and visibility distance (V), although our measurements of sigma are 7–11% higher under equivalent signage luminance. Our findings on the sigma versus normalized brightness at a 15.5 m distance align with Jin's results, while a 20% discrepancy is observed at 10.5 m and 5.5 m distances. At high ambient light (180 lx), the K=sigma*V is comparable in Jin's experiment (from 5 to 8) and this work (from 4.7 to 9.5). However, at low ambient light (less than 22 lx), the signage remains visible in higher smoke extinction coefficients (with K from 6 to 11). The critical extinction coefficient decreases by nearly 40% for every 5 m increase in visibility distance. This work deepens the understanding of smoke visibility under a dark fire environment, which may help guide fire signage design and inspire new fire evacuation research
Contrasting temperature response of photosynthesis in early- and late-successional tree species from a reforested Neotropical forest
No full textThe Atlantic Forest is critically threatened by habitat fragmentation, requiring various restoration efforts to restore essential ecosystem functions. However, with the projected rise in extreme weather events such as heatwaves and droughts, the success of ecological restoration will depend on species’ ability to perform at higher temperatures. To better understand the thermal response of tree species in restored Atlantic Forest areas, we measured carbon assimilation under saturating light (Asat), the maximum rate of RuBP carboxylation (VCmax), the rate of electron transport (Jmax), and stomatal conductance (gs) in six species from contrasting successional groups in a restored area, across a range of leaf temperatures to determine their thermal optima for each parameter (TOptA, TOptV, TOptJ, and TOpgs, respectively). We tested the difference in thermal optima between early- and late-successional species and examined stomatal and biochemical control over TOptA. As a result, no significant differences were found in the photosynthetic thermal optimum between successional groups. Additionally, TOptgs was most strongly correlated with TOptA. However, TOptA in early successional species exhibited a stronger relationship with TOptJ, which contradicts findings in the literature for tropical biomes. These contrasting results raise important questions about the ecological and physiological mechanisms that may differ between reforested and natural ecosystems. Consequently, further research is needed to better understand species acclimation and adaptation in restored areas
Emulation-based self-supervised SIF retrieval in the O-A absorption band with HyPlant
No full textThe retrieval of sun-induced fluorescence (SIF) from hyperspectral imagery requires accurate atmospheric compensation to correctly disentangle its small contribution to the at-sensor radiance from other confounding factors. In spectral fitting SIF retrieval approaches this compensation is estimated in a joint optimization of free variables when fitting the measured at-sensor signal. Due to the computational complexity of Radiative Transfer Models (RTMs) that satisfy the level of precision required for accurate SIF retrieval, fully joint estimations are practically unachievable with exact physical simulation. We present in this contribution an emulator-based spectral fitting method neural network (EmSFMNN) approach integrating RTM emulation and self-supervised training for computationally efficient and accurate SIF retrieval in the O-A absorption band of HyPlant imagery. In a validation study with in-situ top-of-canopy SIF measurements we find improved performance over traditional retrieval methods. Furthermore, we show that the model predicts plausible SIF emission in topographically variable terrain without scene-specific adaptations. Since EmSFMNN can be adapted to hyperspectral imaging sensors in a straightforward fashion, it may prove to be an interesting SIF retrieval method for other sensors on airborne and spaceborne platforms