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Batteries are a key resource in the quest for sustainable energy. Here, the theoretical basis is presented for a new type of electrochemical concentration cell that might contribute to this enterprise. The cell, which has been successfully demonstrated in the laboratory, incorporates a chemically asymmetric membrane to drive anisotropic diffusion between two solution chambers; the resulting concentration difference powers the cell. In this study, the membrane’s operation is validated via three theoretical approaches: (i) traditional equilibrium thermodynamics; (ii) balancing drift and diffusion current densities; and (iii) the time-independent diffusion equation. The physical criteria for its operation are developed and its dimensionless variables identified. The cell’s maximum instantaneous power density might exceed 107 W/m3. Its self-charging capability should confer multiple advantages over traditional concentration cells (as well as over some voltaics), including improved thermodynamic efficiency, economy, and compactness. Commonalities with other electrochemical systems (e.g., liquid chromatography, metal corrosion, and solid state diodes) are discussed, and a physical instantiation of the cell is reviewed. Recent numerical simulations corroborate its essential processes.

Understanding the formation of substructures in protoplanetary disks is vital for gaining insights into dust growth and the process of planet formation. Studying these substructures in highly embedded Class 0 objects using the Atacama Large Millimeter/submillimeter Array (ALMA), however, poses significant challenges. Nonetheless, it is imperative to do so to unravel the mechanisms and timing behind the formation of these substructures. In this study, we present high-resolution ALMA data at Bands 6 and 4 of the NGC1333 IRAS4A Class 0 protobinary system. This system consists of two components, A1 and A2, separated by 1.8\" and located in the Perseus molecular cloud at \\(\\)293 pc distance. To gain a comprehensive understanding of the dust properties and formation of substructures in the early stages, we conducted a multi-wavelength analysis of IRAS4A1. Additionally, we sought to address whether the lack of observed substructures in very young disks, could be attributed to factors such as high degrees of disk flaring and large scale heights. To explore this phenomenon, we employed radiative transfer models using RADMC-3D. Our multi-wavelength analysis of A1 discovered characteristics such as high dust surface density, substantial dust mass within the disk, and elevated dust temperatures. These findings suggest the presence of large dust grains compared to the ones in the interstellar medium (ISM), greater than 100 microns in size within the region. Furthermore, while there's no direct detection of any substructure, our models indicate that some, such as a small gap, must be present. In summary, this result implies that disk substructures may be masked or obscured by a large scale height in combination with a high degree of flaring in Class 0 disks. [Abridged]

We present ALMA observations of the Orion Nebula that cover the OMC1 outflow region. Our focus in this paper is on compact emission from protoplanetary disks. We mosaicked a field containing \\(\\sim 600\\) near-IR-identified young stars, around which we can search for sub-mm emission tracing dusty disks. Approximately 100 sources are known proplyds identified with HST. We detect continuum emission at 1 mm wavelengths towards \\(\\sim 20\\%\\) of the proplyd sample, and \\(\\sim 8\\%\\) of the larger sample of near-IR objects. The noise in our maps allows 4\\(\\sigma\\) detection of objects brighter than \\(\\sim 1.5\\) mJy, corresponding to protoplanetary disk masses larger than 1.5 M\\(_{\\rm J}\\) (using standard assumptions about dust opacities and gas-to-dust ratios). None of these disks are detected in contemporaneous CO(2-1) or C\\(^{18}\\)O(2-1) observations, suggesting that the gas-to-dust ratios may be substantially smaller than the canonical value of 100. Furthermore, since dust grains may already be sequestered in large bodies in ONC disks, the inferred masses of disk solids may be underestimated. Our results suggest that the distribution of disk masses in this region is compatible with the detection rate of massive planets around M dwarfs, which are the dominant stellar constituent in the ONC.

We present ALMA 850 \\(\\mu\\)m continuum observations of the Orion Nebula Cluster that provide the highest angular resolution (\\(\\sim 0\\rlap{.}''1 \\approx 40\\) AU) and deepest sensitivity (\\(\\sim 0.1\\) mJy) of the region to date. We mosaicked a field containing \\(\\sim 225\\) optical or near-IR-identified young stars, \\(\\sim 60\\) of which are also optically-identified \"proplyds\". We detect continuum emission at 850 \\(\\mu\\)m towards \\(\\sim 80\\)% of the proplyd sample, and \\(\\sim 50\\)% of the larger sample of previously-identified cluster members. Detected objects have fluxes of \\(\\sim 0.5\\)-80 mJy. We remove sub-mm flux due to free-free emission in some objects, leaving a sample of sources detected in dust emission. Under standard assumptions of isothermal, optically thin disks, sub-mm fluxes correspond to dust masses of \\(\\sim 0.5\\) to 80 Earth masses. We measure the distribution of disk sizes, and find that disks in this region are particularly compact. Such compact disks are likely to be significantly optically thick. The distributions of sub-mm flux and inferred disk size indicate smaller, lower-flux disks than in lower-density star-forming regions of similar age. Measured disk flux is correlated weakly with stellar mass, contrary to studies in other star forming regions that found steeper correlations. We find a correlation between disk flux and distance from the massive star \\(\\theta^1\\) Ori C, suggesting that disk properties in this region are influenced strongly by the rich cluster environment.

We document that ownership by officers and directors of publicly traded firms is on average higher today than earlier in the century. Managerial ownership has risen from 13 percent for the universe of exchange-listed corporations in 1935, the earliest year for which such data exist, to 21 percent in 1995. We examine in detail the robustness of the increase and explore hypotheses to explain it. Higher managerial ownership has not substituted for alternative corporate governance mechanisms. Lower volatility and greater hedging opportunities associated with the development of financial markets appear to be important factors explaining the increase in managerial ownership.

ABSTRACT Ephemeral wetlands, such as vernal pools and playas, have become increasingly threatened by a variety of destructive human practices, including off-highway vehicle (OHV) activity. Among the resident animals that may be adversely affected are the branchiopod crustaceans which produce desiccation resistant cysts to withstand the pools' dry periods. We report a quantitative investigation of the force required to crush individual branchiopod cysts of 8 species: Branchinecta lynchi, B. sandiegonensis, B. mackini, Streptocephalus woottoni, Thamnocephalus platyurus, Linderiella occidentalis, Lepidurus lemmoni, and Triops longicaudata. Very small forces of less than 1 newton crushed dry cysts. Wet cysts were even more fragile; many were crushed under less than 7 X 10-2 newtons. Differences in vulnerability were found within and between taxa and may be related to cyst morphology. Knowledge of these effects should be taken into consideration when developing management strategies for ephemeral wetlands.

We present dynamical masses for 23 pre-main sequence K- and M-type stars in the Upper Scorpius star-forming region. These masses were derived from the Keplerian rotation of CO disk gas using the MCMC radiative-transfer package pdspy and a flared-disk model with 15 free parameters. We compare our dynamical masses to those derived from five pre-main sequence evolutionary models, and find that most models consistently underestimate stellar mass by \\(\\)25%. Models with updated treatment of stellar magnetic fields are a notable exception \\(-\\) they consistently return stellar masses in good agreement with the dynamical results. We find that the magnetic models' performance is valid even at low masses, in contrast with some literature results suggesting they may overestimate stellar mass for M\\(_\\) \\(\\) 0.6 M\\(_\\). Our results are consistent with dynamical versus isochronal evaluations for younger samples (e.g. Taurus, 1-3 Myr), and extend the systematic evaluation of stellar evolutionary models up to stars \\(\\)11 Myr in age. Finally, we derive disk dust masses to evaluate whether using dynamical masses versus isochronal masses changes the slope of the log(M\\(_dust\\))\\(-\\)log(M\\(_\\)) relation. We derive a slightly shallower relation using dynamical masses versus isochronal masses, but the slopes of these relations agree within uncertainties. In all cases, we derive a steeper-than-linear relation for log(M\\(_dust\\))\\(-\\)log(M\\(_\\)), consistent with previous literature results for Upper Sco.