The effects of ionic size asymmetry on long-range electrostatic interactions in electrolyte solutions are investigated within the primitive model. Using the formalism of dressed ion theory we analyze correlation functions from Monte Carlo simulations and the hypernetted chain approximation for size asymmetric 1:1 electrolytes. We obtain decay lengths of the screened Coulomb potential, effective charges of ions, and effective permittivity of the solution. It is found that the variation of these quantities with the degree of size asymmetry depends in a quite intricate manner on the interplay between the electrostatic coupling and excluded volume effects. In most cases the magnitude of the effective charge of the small ion species is larger than that of the large species; the difference increases with increasing size asymmetry. The effective charges of both species are larger (in absolute value) than the bare ionic charge, except for high asymmetry where the effective charge of the large ions can become smaller than the bare charge.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1063/1.1843811 | DOI Listing |
J Acoust Soc Am
January 2025
Department of Hearing and Speech Sciences, University of Maryland, College Park, Maryland 20742, USA.
Threshold estimation procedures are widely used to measure the stimulus level corresponding to a specified probability of response. The weighted up-and-down procedure, familiar to many due to its use in standard pure-tone audiometry, allows the experimenter to target any probability of response by using different ascending and descending step sizes. Unfortunately, thresholds have a signed mean error that made using weighted staircases inadvisable.
View Article and Find Full Text PDFAnat Rec (Hoboken)
January 2025
Muséum national d'Histoire naturelle, Centre de Recherche en Paléontologie-Paris (CR2P), UMR 7207 MNHN/CNRS/UPMC, Sorbonne Université, Paris, France.
Pangolins are the most heavily trafficked mammals in the world, largely because of the high demand for their keratinous scales from the traditional Chinese medicine market. While seizures of pangolin material are largely composed of isolated scales, efficient approaches to reach species-level identification are missing. This mostly originates from the lack of comparative studies on the shape of pangolin scales, resulting in knowledge gaps on the imbricated effects of serial, ontogenetic, and evolutionary variations.
View Article and Find Full Text PDFJ Orthop Surg Res
January 2025
Center for Rehabilitation Research, School of Allied Health Sciences, Texas Tech University Health Sciences Center, Lubbock, TX, USA.
Background: The sacroiliac joints (SIJ) are specialized articulations in the pelvis that allow load transfer between the upper and lower body. Traumatic pelvic disruption often requires surgical fixation of at least one of these joints. Subsequent SIJ pain is associated with asymmetries in joint laxity or stiffness.
View Article and Find Full Text PDFAJNR Am J Neuroradiol
January 2025
From the Division of Neuroradiology, Department of Radiology (M.T.W., A.M., C.A.P.F.A., O.S, E.S.S.), and Department of Obstetrics and Gynecology (N.K.), Children's Hospital of Philadelphia, Philadelphia, PA, USA; Perelman School of Medicine (M.T.W., N.K., E.S.S.), Philadelphia, PA, USA; Division of Neuroradiology, Department of Radiology (C.A.P.F.A), Boston Children's Hospital, Boston, MA, USA; and Harvard Medical School (C.A.P.F.A), Boston, MA, USA.
Background And Purpose: Frontal paraventricular cystic changes have a varied etiology that includes connatal cysts, subependymal pseudocysts, necrosis, and enlarged perivascular spaces. These may be difficult to distinguish by neuroimaging and have a variety of associated prognoses. We aim to refine the neuroimaging definition of frontal horn cysts and correlate it with adverse clinical conditions.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Institute of Environmental Engineering, Department of Civil, Environmental and Geomatic Engineering, ETH Zürich, Zürich 8093, Switzerland.
Chemotaxis enables marine bacteria to increase encounters with phytoplankton cells by reducing their search times, provided that bacteria detect noisy chemical gradients around phytoplankton. Gradient detection depends on bacterial phenotypes and phytoplankton size: large phytoplankton produce spatially extended but shallow gradients, whereas small phytoplankton produce steeper but spatially more confined gradients. To date, it has remained unclear how phytoplankton size and bacterial swimming speed affect bacteria's gradient detection ability and search times for phytoplankton.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!