Solid-state electrolytes such as cubic Li6.25Al0.25La3Zr2O12 (LLZO) can enable solid-state batteries, metallic lithium anodes and higher voltage cathodes. However, the stability of cubic LLZO is ...affected by current density. In beta alumina solid electrolyte, microstructural failure was caused by Na dendrite penetration, and was shown to be a function of the fracture toughness, KIC. The relationship between dendrite penetration and KIC indicates electronic failure is related to creation of microstructural damage, and the microstructural damage may be used as an indicator of imminent electronic failure. To monitor microstructural damage during cycling, we developed a non-invasive, in-situ cell monitoring apparatus to help to correlate mechanical stability with Li-ion current density in LLZO. A pulse-echo transducer was integrated into all solid-state Li-LLZO-Li cells. The capability enables the characterization of microscopic inhomogeneities through the careful measurement of changes to the elastic moduli. The elastic moduli and fracture toughness have been previously reported for dense (>99%) specimens, but monitoring of the relative change in moduli during cycling has not been explored. In this study, an acoustic monitoring method is presented to monitor LLZO specimens during cycling.
•Dendrite penetration in solid state electrolytes causes short-circuiting.•Acoustic pulse-echo technique monitors changes in microstructural integrity in-situ.•Can observe dendrite propagation by reduction in stiffness.
The developments in lithographic tools for the production of an integrated circuit (IC) are ruled by 'Moore's Law': the density of components on an IC doubles in about every two years. The ...corresponding size reduction of the smallest detail in an IC entails several technological breakthroughs. The wafer scanner, the exposure system that defines those details, is the determining factor in these developments. This review deals with those aspects of the positioning systems inside these wafer scanners that enable the extension of Moore's Law into the future. The design of these systems is increasingly difficult because of the accuracy levels in the sub-nanometre range coupled with motion velocities of several metres per second. In addition to the use of feedback control for the reduction of errors, high-precision model-based feed-forward control is required with an almost ideally reproducible motion-system behaviour and a strict limitation of random disturbing events. The full mastering of this behaviour even includes material drift on an atomic scale and is decisive for the future success of these machines.
The oxide known as LLZO, with nominal composition Li7La3Zr2O12, is a promising solid electrolyte for Li-based batteries due to its high Li-ion conductivity and chemical stability with respect to ...lithium. Solid electrolytes may also enable the use of metallic Li anodes by serving as a physical barrier that suppresses dendrite initiation and propagation during cycling. Prior linear elasticity models of the Li electrode/solid electrolyte interface suggest that the stability of this interface is highly dependent on the elastic properties of the solid separator. For example, dendritic suppression is predicted to be enhanced as the electrolyte’s shear modulus increases. In the present study a combination of first-principles calculations, acoustic impulse excitation measurements, and nanoindentation experiments are used to determine the elastic constants and moduli for high-conductivity LLZO compositions based on Al and Ta doping. The calculated and measured isotropic shear moduli are in good agreement and fall within the range of 56–61 GPa. These values are an order of magnitude larger than that for Li metal and far exceed the minimum value (∼8.5 GPa) believed to be necessary to suppress dendrite initiation. These data suggest that LLZO exhibits sufficient stiffness to warrant additional development as a solid electrolyte for Li batteries.
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•Endmember extraction and soft modeling in hyperspectral Raman imaging are compared.•Three simulated cases, a pharmaceutical sample, and plastic foils were studied.•VCA outputs can be ...used as initialization for MCR-ALS.•Pure pixels are required for extracting pure variables by VCA, but not for MCR-ALS.
Hyperspectral Raman imaging not only offers spectroscopic fingerprints but also reveals morphological information such as spatial distributions in an analytical sample. However, the spectrum-per-pixel nature of hyperspectral imaging (HSI) results in a vast amount of data. Furthermore, HSI often requires pre- and post-processing steps to extract valuable chemical information. To derive pure spectral signatures and concentration abundance maps of the active spectroscopic compounds, both endmember extraction (EX) and Multivariate Curve Resolution (MCR) techniques are widely employed. The objective of this study is to carry out a systematic investigation based on Raman mapping datasets to highlight the similarities and differences between these two approaches in retrieving pure variables, and ultimately provide guidelines for pure variable extraction. Numerical simulations and Raman mapping experiments on a mixture of pharmaceutical powders and on a layered plastic foil sample were conducted to underscore the distinctions between MCR and EX algorithms (in particular Vertex Component Analysis, VCA) and their outputs. Both methods were found to perform well if the dataset contains pure pixels for each of the individual components. However, in cases where such pure pixels do not exist, only MCR was found to be capable of extracting the pure component spectra.
The discovery that half of the mammalian protein-coding genome is regulated by the circadian clock has clear implications for medicine. Recent studies demonstrated that the circadian clock influences ...therapeutic outcomes in human heart disease and cancer. However, biological time is rarely given clinical consideration. A key barrier is the absence of information on tissue-specific molecular rhythms in the human body. We have applied the cyclic ordering by periodic structure (CYCLOPS) algorithm, designed to reconstruct sample temporal order in the absence of time-of-day information, to the gene expression collection of 13 tissues from 632 human donors. We identified rhythms in gene expression across the body; nearly half of protein-coding genes were shown to be cycling in at least 1 of the 13 tissues analyzed. One thousand of these cycling genes encode proteins that either transport or metabolize drugs or are themselves drug targets. These results provide a useful resource for studying the role of circadian rhythms in medicine and support the idea that biological time might play a role in determining drug response.
•We study dynamic coalition formation, applied to climate cooperation.•Our model allows for multiple rounds of negotiations.•Countries join the coalition and sign an agreement to prevent inefficient ...delay.•We are able to explain the formation of large coalitions in equilibrium.
We introduce a novel framework for analyzing coalition formation, applied to climate cooperation. Our model allows for multiple rounds of negotiations and is able to explain the formation of large coalitions. The incentive of each coalition member to join and subsequently to sign a long-term contract is to prevent inefficient delay that arises as soon as a single country deviates. This undermines the free-rider incentive that destabilizes large coalitions in static coalition formation games. The equilibrium coalition size is then determined by a “threshold effect” due to which deviations of coalition members become unprofitable for sufficiently large coalitions.
A simple model of panic buying Schmidt, Robert C.; Westbrock, Bastian; Hoegen, Hendrik
Journal of economic behavior & organization,
12/2023, Volume:
216
Journal Article
Peer reviewed
We study a simple dynamic model to rationalize episodes of excess demand that resemble “panic buying” episodes in actual markets. In such episodes, consumers compete for a scarce good. Scarcity is ...triggered by an anticipated negative supply shock that takes place in a future period with positive probability. To avoid the risk of non-consumption, consumers can stockpile the good in earlier periods. We demonstrate that these stockpiling decisions can reinforce each other, creating a cascade of excess demand in several periods similar to “panic buying” episodes observed, for instance, during the Corona crisis. In our model, stockpiling is always detrimental to welfare, and we develop a suitable policy response.
Pituitary adenomas are rare in children and adolescents and although mostly benign, they can sometimes be challenging to manage due to their locally invasive nature. In this study, we examined the ...clinicopathologic features of 42 pituitary adenomas in patients ≤21 years of age. The youngest patient was 8 years old (median age: 18 years), and the female-to-male ratio was 1.8:1. Five patients had recurrence after resection. There was no obvious difference between the recurrent rates in the typical (11.7%) and atypical adenomas (12.5%) based on the 2004 WHO classification. However, the recurrence rate was much higher in adenomas with an elevated proliferation index of ≥3% (20.8%) or with evidence of local invasion (18.2%). Adenomas with combination of an elevated proliferation index of ≥3% and imaging evidence of local invasion had the highest recurrence rate of 25%. In summary, pituitary adenomas are more frequent in adolescents as compared with children and are more common in girls. An elevated proliferation index of ≥3% and evidence of local invasion on imaging seem to correlate with a high probability of recurrence. Furthermore, we observe rarity of α-thalassemia/mental retardation syndrome X-linked (ATRX) protein loss (surrogate to ATRX mutation) in these tumors without any connotation on prognosis.
Neuronal oscillations allow for temporal segmentation of neuronal spikes. Interdependent oscillators can integrate multiple layers of information. We examined phase-phase coupling of theta and gamma ...oscillators in the CA1 region of rat hippocampus during maze exploration and rapid eye movement sleep. Hippocampal theta waves were asymmetric, and estimation of the spatial position of the animal was improved by identifying the waveform-based phase of spiking, compared to traditional methods used for phase estimation. Using the waveform-based theta phase, three distinct gamma bands were identified: slow gamma(S) (gamma(S); 30-50 Hz), midfrequency gamma(M) (gamma(M); 50-90 Hz), and fast gamma(F) (gamma(F); 90-150 Hz or epsilon band). The amplitude of each sub-band was modulated by the theta phase. In addition, we found reliable phase-phase coupling between theta and both gamma(S) and gamma(M) but not gamma(F) oscillators. We suggest that cross-frequency phase coupling can support multiple time-scale control of neuronal spikes within and across structures.
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