1,272 research outputs found
Model charged cylindrical nanopore in a colloidal dispersion: charge reversal, overcharging and double overcharging
Using the hypernetted-chain/mean spherical approximation (HNC/MSA) integral
equations we study the electrical double layer inside and outside a model
charged cylindrical vesicle (nanopore) immersed into a primitive model
macroions solution, so that the macroions are only present outside the
nanopore, i.e., the vesicle wall is impermeable only to the external macroions.
We calculate the ionic and local linear charge density profiles inside and
outside the vesicle, and find that the correlation between the inside and
outside ionic distributions causes the phenomena of overcharging (also referred
to as surface charge amplification) and/or charge reversal. This is the first
time overcharging is predicted in an electrical double layer of cylindrical
geometry. We also report the new phenomenon of double overcharging. The present
results can be of consequence for relevant systems in physical-chemistry,
energy storage and biology, e.g., nanofilters, capacitors and cell membranes.Comment: 10 pages, 4 figure
The (Possibly) Injured Consumer: Standing in Data Breach Litigation
(Excerpt)
This Note will address the question of what factors a prospective plaintiff must display to “push [a] threatened injury of future identity theft beyond the speculative to the sufficiently imminent.” Part I will delve into relevant statistics to identify the characteristics of a data breach that most often lead to eventual identity theft. Part II will explore recent data breach standing cases and analyze the factual differences and legal perspectives that have led to disparate results among the federal circuits. Lastly, Part III will recommend a method for evaluating future data breach standing issues
Overcharging: The Crucial Role of Excluded Volume
In this Letter we investigate the mechanism for overcharging of a single
spherical colloid in the presence of aqueous salts within the framework of the
primitive model by molecular dynamics (MD) simulations as well as
integral-equation theory. We find that the occurrence and strength of
overcharging strongly depends on the salt-ion size, and the available volume in
the fluid. To understand the role of the excluded volume of the microions, we
first consider an uncharged system. For a fixed bulk concentration we find that
upon increasing the fluid particle size one strongly increases the local
concentration nearby the colloidal surface and that the particles become
laterally ordered. For a charged system the first surface layer is built up
predominantly by strongly correlated counterions. We argue that this a key
mechanism to produce overcharging with a low electrostatic coupling, and as a
more practical consequence, to account for charge inversion with monovalent
aqueous salt ions.Comment: 7 pages, 3 figs (4 EPS files). To appear in Europhysics Letter
Entropy driven key-lock assembly
The effective interaction between a sphere with an open cavity (lock) and a
spherical macroparticle (key), both immersed in a hard sphere fluid, is studied
by means of Monte Carlo simulations. As a result, a 2d map of the key-lock
effective interaction potential is constructed, which leads to the proposal of
a self-assembling mechanism: there exists trajectories through which the
key-lock pair could assemble avoiding trespassing potential barriers. Hence,
solely the entropic contribution can induce their self-assembling even in the
absence of attractive forces. This study points out the solvent contribution
within the underlying mechanisms of substrate-protein assembly/disassembly
processes, which are important steps of the enzyme catalysis and protein
mediated transport
May I Hold on to My God as I Die?: An Analysis on a Death Row Inmate\u27s Right to Spiritual Advisors Inside the Execution Chamber
This article analyzes the first amendment right of condemned prisoners to have their spiritual advisor with them up to the point of execution. It dives into a brief yet relevant historical background of the death penalty in the United States. Then it analyzes the specific protections awarded to death penalty inmates up to the point of their executions through R.L.U.I.P.A. At its core, it compares and contrasts two recent decisions by the U.S. Supreme Court: Dunn v. Ray, 139 S. Ct. 661 (2019) and Murphy v. Collier, 139 S. Ct. 1111 (2019), in which the Court reached two different conclusions regarding the matter of a prisoner\u27s right to a spiritual advisor during execution. The comparison is made in the light of the Establishment Clause and Free exercise of religion, as established in the First Amendment of the Constitution. It concludes that denying condemned prisoners a right to have their spiritual advisor with them up to the point of execution is a violation of their First Amendment rights, as guaranteed by the Constitution
Cognitive Plasticity in Foraging Vespula germanica Wasps
Vespula germanica (F.) (Hymenoptera: Vespidae) is a highly invasive social wasp that exhibits a rich behavioral repertoire in which learning and memory play a fundamental role in foraging. The learning abilities of these wasps were analyzed while relocating a food source and whether V. germanica foragers are capable of discriminating between different orientation patterns and generalizing their choice to a new pattern. Foraging wasps were trained to associate two different stripe orientation patterns with their respective food locations. Their response to a novel configuration that maintained the orientation of one of the learned patterns but differed in other aspects (e.g. width of stripes) was then evaluated. The results support the hypothesis that V. germanica wasps are able to associate a particular oriented pattern with the location of a feeder and to generalize their choice to a new pattern, which differed in quality, but presented the same orientation
The electrical double layer for a fully asymmetric electrolyte around a spherical colloid: an integral equation study
The hypernetted chain/mean spherical approximation (HNC/MSA) integral
equation is obtained and solved numerically for a totally asymmetric primitive
model electrolyte around a spherical macroparticle. The ensuing radial
distribution functions show a very good agreement when compared to our Monte
Carlo and molecular dynamics simulations for spherical geometry and with
respect to previous anisotropic reference HNC calculations in the planar limit.
We report an analysis of the potential vs charge relationship, radial
distribution functions, mean electrostatic potential and cumulative reduced
charge for representative cases of 1:1 and 2:2 salts with a size asymmetry
ratio of 2. Our results are collated with those of the Modified Gouy-Chapman
(MGC) and unequal radius Modified Gouy-Chapman (URMGC) theories and with those
of HNC/MSA in the restricted primitive model (RPM) to assess the importance of
size asymmetry effects. One of the most striking characteristics found is
that,\textit{contrary to the general belief}, away from the point of zero
charge the properties of an asymmetric electrical double layer (EDL) are not
those corresponding to a symmetric electrolyte with the size and charge of the
counterion, i.e. \textit{counterions do not always dominate}. This behavior
suggests the existence of a new phenomenology in the EDL that genuinely belongs
to a more realistic size-asymmetric model where steric correlations are taken
into account consistently. Such novel features can not be described by
traditional mean field theories like MGC, URMGC or even by enhanced formalisms,
like HNC/MSA, if they are based on the RPM.Comment: 29 pages, 13 figure
Acceptability of yacon flakes (Smallanthus sonchifolia) for dietary use with inulin
"This study aimed to elaborate on yacon flakes and determine the proximal composition of
fresh yacon and final flakes, made at different temperatures (120°C, 150°C and 180°C) for
20 mins. We measured the acceptability of the sensory attributes: taste, texture, odour and
colour and the global acceptability at the laboratory level, using semi-trained panellists
and an unstructured hedonic scale. The acceptability of the flakes was measured at
different temperatures. Our results indicate that the flakes made at 180°C had the highest
acceptance (87%), and the flakes made at 120°C had 80% of unacceptability. Our data
were analysed according to the analysis of variance (ANOVA) and Tukey's test. We found
significant differences between the averages of the taste scores (T0:7.1; T1:7.6; T2:6.7;
T3:4.6), p<0.05; texture (T0:7.1; T1:7.2; T2:5.7; T3:4.5), p<0.05; and odour (T0:7.2;
T1:7.6; T2:5.1; T3:3.3), p<0.05. The amount of fructooligosaccharides on a fresh basis
was Ⱦ±SD (31.60±0.650) and on a dry basis (37.44±1DS). Microbiological analysis
shows that the flakes are fit for human consumption. It is concluded that yacon flakes
contain significant amounts of inulin, being a good substitute alternative for the
preparation of snack-type dietetic products
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