Unmixed State Research Articles

Synthesis and characterization of biocompatible silver nanoparticles with increased anti-Diabetic and anti-Microbial effectiveness via the mediation of aquatic plant Hygrophila corymbosa

Using extracts from plants and seaweed to make metal nanoparticles is an interesting topic that has some advantages over more traditional physicochemical methods. Recent developments in nanoscience and nanobiotechnology have made it possible for these breakthroughs. Nevertheless, the production of nanoparticles via the use of aquatic plants and the applications of these particles are not very well recognized. This article described an ecologically friendly method of producing AgNPs by employing the aquatic plant Hygrophila corymbosa as the starting material. The examination of the zeta potential at −31.4 mV reveals that the AgNPs that were synthesized were stable for an extended period of time. The pictures produced by the HR-TEM indicated the presence of polydispersed, spherical-shaped nanoparticles with a size of less than 20 nm and distinct lattice fringes. The unmixed state of the AgNPs is represented by the peak in the EDX spectroscopy that was found at roughly 3 keV. XRD studies revealed that the AgNPs were found to be fcc in nature with miller indices of (111), (200), (220), and (311), and the average particle size was found to be 43 nm. The compounds having functional groups secondary amine, alkane, primary amide, and aldehyde in the plants in charge of the reduction of AgNO3 into AgNPs were listed using FT-IR analysis. Gram-positive bacteria B. subtilis, S. aureus, S. mutans, E. faecalis, andL. salivarius, and gram-negative bacteria P. mirabilis, P. vulgaris, K. pneumoniae, P. aeruginosa, andE. coli, as well as the fungal strains Candida albicans, Aspergillus flavus, and Aspergillus niger, were used to test the anti-microbial activity of the AgNPs produced. The outcome demonstrates the potential anti-microbial activity of the produced AgNPs. The anti-diabetic effect of the produced AgNPs was determined using alpha-amylase inhibition test, and they possess excellent efficacy (IC50 value of 47.72) compared with the standard used. These findings demonstrated that AgNPs synthesized using aquatic plants are highly stable and have a higher potential for biological activities.

“Clutch[ing] Gold”: Wives, Mothers, and Property Law in The Ring and the Book

“Clutch[ing] Gold”: Wives, Mothers, and Property Law in The Ring and the Book Jill Rappoport (bio) In Robert Browning’s epic exploration of a 1698 murder case, Count Guido Franceschini confesses to killing his wife Pompilia, confident that her alleged dishonor justifies his action and, crucially, that the money he married for will pass into his hands despite his guilt. Because his responsibility for the deed is never in question, the poem’s twelve-book, multivocal narration of Guido’s trials uses this murder less to assign blame than to invite assessments of seventeenth-century systems of gender, justice, and property. Those systems may seem remote from the companionate marriages and reformed divorce laws of the nineteenth century, yet The Ring and the Book (1868–1869) also encourages Victorian readers to judge their own present legal system through its critique of the earlier Italian laws, softening the implications of more direct commentary by “Linking our England to his Italy.”1 Along these lines, Pompilia’s tragic union with Guido has been compared to the Victorian marriage market, commonly understood to traffic in women.2 Guido unequivocally views his wife as a possession, “avow[ing that he] dared buy / A girl,” calculating “the market-price” of his title in that exchange, and expecting that “when I buy, timber and twig, a tree— / I buy the song o’ the nightingale inside” (V: ll. 425–426; V: l. 462; V: ll. 605–606). Pompilia’s struggle for ownership has been framed, accordingly, in terms of her claims to body, spirit, and child, rather than to the substantial material wealth for which she acts as conduit. Discussions of material property in the poem, on the other hand, generally emphasize inheritance and its vertical and male lines of descent, focusing on birth and confusion over rightful heirship rather than on wives or marriage (Petch, “Law” p. 318). Yet a wife’s economic agency is central both to the poem’s tragedy and to English legal debates during the years when The Ring and the Book was being written. Whether or not women should lose their claims to property upon marriage or continue to inherit, earn, possess, or alienate independent wealth was a vital question during the 1860s, and Browning’s poem [End Page 1] engages in it, not only through Pompilia and her embattled inheritance but also through the actions of her biological and adoptive mothers. The decades-long Victorian reform of married women’s property law is typically understood in terms of its effects on wives and marriage, but as we will see, the prospect of changing marital rights affected entire families and unsettled other features of Victorian life as well. In its depictions of money-wielding mothers, Browning’s poem reflects cultural tensions regarding these economic developments. By demonstrating sympathy toward disempowered wives along with widespread concern regarding the generational ramifications of maternal economic agency, The Ring and the Book underscores the dissonance in popular attitudes toward women’s property rights shortly before the first legal reforms. If in this telling the “British Public” the poem addresses remains ambivalent,3 depictions of Guido’s trial render a more consistent verdict, finally suggesting the necessity not only of improving individual laws but of altering the court system itself. I. “He Only Stipulated for the Wealth” (VII: l. 779): Property Matters in Marriage The golden “Ring” that opens and names Browning’s poem has invited copious critical interpretation as “a figure, a symbol, say; / A thing’s sign” (I: ll. 31–32).4 But it is also, and essentially, a piece of precious metal. Temporarily mixed with alloy to create a “manageable mass” (I: l. 21), the ring, once shaped, returns to its original, unmixed state: “Prime nature with an added artistry— / No carat lost” (I: ll. 29–30).5 As a costly object of enduring value, this metal— “Gold as it was, is, shall be evermore” (I: l. 28)—introduces the key problem of property into this variably retold trial. Valuable property and the question of whose “it was, is, shall be” motivate adoption, marriage, and murder in The Ring and the Book and explicitly and implicitly figure in the social and...

Phase-controlled field-effect micromixing using AC electroosmosis

The exploration and application of electrokinetic techniques in micro total analysis systems have become ubiquitous in recent years, and scientists are expanding the use of such techniques in areas where comparable active or passive methods are not as successful. In this work, for the first time, we utilize the concept of AC electroosmosis to design a phase-controlled field-effect micromixer that benefits from a three-finger sinusoidally shaped electrodes. Analogous to field-effect transistor devices, the principle of operation for the proposed micromixer is governed by the source-gate and source-drain voltage potentials that are modulated by introducing a phase lag between the driving electrodes. At an optimized flow rate and biasing scheme, we demonstrate that the source, gate, and drain voltage phase relations can be configured such that the micromixer switches from an unmixed state (phase shift of 0°) to a mixed state (phase shift of 180°). High mixing efficiencies beyond 90% was achieved at a volumetric flow rate of 4 µL/min corresponding to ~13.9 mm/s at optimized voltage excitation conditions. Finally, we employed the proposed micromixer for the synthesis of nanoscale lipid-based drug delivery vesicles through the process of electrohydrodynamic-mediated nanoprecipitation. The phase-controlled electrohydrodynamic mixing utilized for the nanoprecipitation technique proved that nanoparticles of improved monodispersity and concentration can be produced when mixing efficiency is enhanced by tuning the phase shifts between electrodes.

An atom probe analysis of self-assembled monolayers: A novel approach to investigate mixed and unmixed self-assembled monolayers (SAMs) on gold

Atom probe tomography was used to analyze self-assembled monolayer of octanethiol and (1H,1H,2H,2H) perfluoro decanethiol (PFDT) in a mixed and unmixed state on a gold surface. The first part of this report, we have analyzed the two SAMs with a direct comparison, whereas in the second part, a binary mixture of these two SAMs (with a 1:1 ratio) are analyzed. Au was taken as a metal substrate in both cases. It has been observed that, although having similar structure and belongs from the same SAMs group, the sequence of evaporation of both chains appeared significantly different molecular fractions in the first case, while in the mixed phase condition the two SAMs chains were arranged in a patchy domain by forming a small nanoscale cluster on the gold surface. Primarily, this study gives an overall understanding of evaporation sequence and surface morphology of the SAMs in an unmixed and mixed condition on the gold substrate, which may lead to the further design process in various applications.

Cutting and shuffling with diffusion: Evidence for cut-offs in interval exchange maps.

Low-dimensional dynamical systems are fruitful models for mixing in fluid and granular flows. We study a one-dimensional discontinuous dynamical system (termed "cutting and shuffling" of a line segment), and we present a comprehensive computational study of its finite-time mixing properties including the effect of diffusion. To explore a large parameter space, we introduce fit functions for two mixing metrics of choice: the number of cutting interfaces (a standard quantity in dynamical systems theory of interval exchange transformations) and a mixing norm (a more physical measure of mixing). We compute averages of the mixing metrics across different permutations (shuffling protocols), showing that the latter averages are a robust descriptor of mixing for any permutation choice. If the decay of the normalized mixing norm is plotted against the number of map iterations rescaled by the characteristic e-folding time, then universality emerges: mixing norm decay curves across all cutting and shuffling protocols collapse onto a single stretched-exponential profile. Next, we predict this critical number of iterations using the average length of unmixed subsegments of continuous color during cutting and shuffling and a Batchelor-scale-type diffusion argument. This prediction, called a "stopping time" for finite Markov chains, compares well with the e-folding time of the stretched-exponential fit. Finally, we quantify the effect of diffusion on cutting and shuffling through a Péclet number (a dimensionless inverse diffusivity), showing that the system transitions more sharply from an unmixed initial state to a mixed final state as the Péclet number becomes large. Our numerical investigation of cutting and shuffling of a line segment in the presence of diffusion thus presents evidence for the latter phenomenon, known as a "cut-off" for finite Markov chains, in interval exchange maps.

Molecular dynamics simulation of Al grain mixing in Fe/Ni matrices and its influence on oxidation

AlxNiyFe(1−x−y) alloys are structural materials with potential application in high-temperature oxidizing environments. These materials are of specific interest as they have the ability to develop an oxidation resistant surface layer. To study diffusion and oxidation processes related to this surface layer formation, the mixing behavior of different sized Al grains in pure Ni and Fe matrices, with approximate grain/matrix atom ratio of 1:3, at temperatures above and below the structure melting point, was studied using ReaxFF-based molecular dynamics simulations. The simulations have been carried out at constant pressure, with temperatures being stepwise ramped over the range of 300-3000 K. For the Ni matrix, our results indicated lower chemical strain energy for Al in the mixed alloy and completion of mixing at a lower temperature for the Fe matrix. These results confirm that the Al-Ni alloy is energetically more stable than the Al-Fe alloy, which is in agreement with experiment. Further, larger Al grains appear to be favorable for mixing with Fe matrix, whereas for Ni matrix, smaller Al grains appear to be favorable. We suggest that this Al grain size effect on mixing matrices is due to the differences in formation energies between Ni/Al and Fe/Al alloys and differences in Ni-Ni and Fe-Fe bond distances. We also performed additional cooling simulations over the temperature range of 3000-300 K. The simulations revealed that for the considered cooling rate Fe alloy solidifies at a lower temperature than Ni alloy. Moreover, both alloys solidify to chemically disordered crystalline structures, of which the Ni structure is less ordered than the Fe structure. Preliminary oxidation simulations of slab structures with single grain indicate that the dynamics of matrix/grain mixing processes have a pronounced influence on the oxidation reactions. We find that Al and Ni atoms in their unmixed state are the most active reactants towards oxygen, while the Al/Ni alloy and pure Fe layers show substantially slower oxidation kinetics.

A quantum solution to Gibbs paradox with few particles

We present a fully quantum solution to the Gibbs paradox (GP) with an illustration based on a gedanken experiment with two particles trapped in an infinite potential well. The well is divided into two cells by a solid wall, which could be removed for mixing the particles. For the initial thermal state with correct two-particle wavefunction according to their quantum statistics, the exact calculations show the entropy changes are the same for boson, fermion and non-identical particles. With the observation that the initial unmixed state of identical particles in the conventional presentations actually is not of a thermal equilibrium, our analysis reveals the quantum origin of the paradox, and confirms Jaynes’ observation that entropy increase in Gibbs mixing is only due to the including more observables. To further show up the subtle role of the quantum mechanism in the GP, we study the different finite size effect on the entropy change and show the work performed in the mixing process is different for various types of particles.

Olfaction: When Nostrils Compete

In vision, alternating percepts occur when two different visual stimuli are presented separately to the two eyes. By analogy, simultaneous presentation of two different odorants separately to the two nostrils has now been shown to cause alternating odor percepts, an effect termed 'binaral rivalry'.

Effect of Storage Conditions Prior to Mixing of β-TCP Based Bone Cement on the Reaction Products and the Setting

β-tricalcium phosphate (β-TCP) based cement features unique biodegradability and mild temperature rise as a material for bone reconstruction. However, the bone cement often raises a shelf life issue and therefore study was made focusing on the temperature and humidity during storage. With the increase of storing days, the density and compressive strength of hardened cement were found to drastically decrease for the cement powder stored in a mixed state. In addition, the setting property was finally lost at the same time. Such a degradation was more evident at higher temperature and was the result of the formation of dicalcium phosphate anhydrous (DCP) instead of dicalcium phosphate dehydrate (DCPD) during the storage. On the contrary, for the cement stored in an unmixed state, very slight changes were detected in density, compressive strength and setting time with the increase of storing days even if the powders were kept in a humid environment. In the unmixed ones, DCP was not precipitated regardless of the storing temperature. Discussion was made on the condition for precipitating either DCPD or DCP in terms of the amount of water supplied during setting. Practically the work suggested that the β-TCP based cement needs to be conserved at lower temperature and in dry environment as possible to effectively increase the shelf life.

Decompression and unmixing of crystals included in diamonds from the mantle transition zone

A suite of exceptional mineral inclusions in diamonds from the Sao Luiz river, Juina province, Brazil, shows a wide range of garnet/majorite mineral compositions co-existing with clinopyroxene; the overall bulk compositions are eclogitic. The inclusions have a wide variety of textural arrangements, but crystallographic data obtained by EBSD shows that each inclusion consists of a single garnet with constant crystallographic orientation whilst clinopyroxene grains have preferred orientation with relation to garnet {110} and . This suggests that the inclusions were originally single phase majoritic garnets, and that they preserve various states of progressive unmixing (exsolution) into lower pressure garnet and clinopyroxene compositions during transport of the host diamonds towards the Earth’s surface. On the basis of high pressure–temperature experimental data some of the original majoritic garnets must have come from depths of 450 km or more, and therefore resided in the transition zone and asthenospheric upper mantle. Particularly extensive re-equilibration of many inclusions took place at depths of ca 180–200 km (probably close to the base of the continental lithosphere). The partially unmixed state of the inclusions provides a unique opportunity for using mineral diffusion data to roughly estimate the rate of transport through the asthenospheric upper mantle, and within error this rate is found to be broadly compatible with expected transport rates by upper mantle convection or plume flow.

HUNTING THE SCALAR GLUEBALL: PROSPECTS FOR BES III

The search for the ground state scalar glueball G0 is reviewed. Spin zero glueballs will have unique dynamical properties if the [Formula: see text] amplitude is suppressed by chiral symmetry, as it is to all orders in perturbation theory: for instance, mixing of G0 with [Formula: see text] mesons would be suppressed, radiative Ψ decay would be a filter for new physics in the spin zero channel, and the decay [Formula: see text] could be enhanced relative to G0 → ππ. These properties are consistent with the identification of f0(1710) as the largely unmixed ground state scalar glueball, while recent BES data implies that f0(1500) does not contain the dominant glueball admixture. Three hypotheses are discussed: that G0 is 1) predominantly f0(1500) or 2) predominantly f0(1710) or 3) is strongly mixed between f0(1500) and f0(1710).

Kelvin–Helmholtz Instability as a Boundary-Value Problem

The Kelvin–Helmholtz (KH) instability is traditionally viewed as an initial-value problem, wherein wave perturbations of a two-layer shear flow grow over time into billows and eventually generate vertical mixing. Yet, the instability can also be viewed as a boundary-value problem. In such a framework, there exists an upstream condition where a lighter fluid flows over a denser fluid, wave perturbations grow downstream to eventually overturn some distance away from the point of origin. As the reverse of the traditional problem, this flow is periodic in time and exhibits instability in space. A natural application is the mixing of a warmer river emptying into a colder lake or reservoir, or the salt-wedge estuary. This study of the KH instability from the perspective of a boundary-value problem is divided into two parts. Firstly, the instability theory is conducted with a real frequency and complex horizontal wavenumber, and the main result is that the critical wavelength at the instability threshold is longer in the boundary-value than in the initial-value situation. Secondly, mass, momentum and energy budgets are performed between the upstream, unmixed state on one side, and the downstream, mixed state on the other, to determine under which condition mixing is energetically possible. Cases with a rigid lid and free surface are treated separately. And, although the algebra is somewhat complicated, both end results are identical to the criterion for complete mixing in the initial-value problem.

Against Restitution

Recently, states and other institutions have undertaken to make restitution for past abuses. Distinctions need to be made between various kinds of restitutive practices that rest on quite different normative grounds. Moreover, the core idea of restitution, in attaching obligation to particular historically grounded relationships, is questionable, and what is being attempted is better explained and justified in terms of a number of standard principles of justice of a non-restitutive kind; for although there is, in principle, a clear case of restitutive justice, its elements rarely, if ever, exist in the real world in an unmixed state. Although there are significant objections to deriving local obligations from principles of universal justice, they have no force in this case. Policies termed ‘restitutive’ may well be justifiable, but they are misdescribed.

Mixing of iron with various metals by high-energy ball milling of elemental powder mixtures

The alloying of Fe with T=V, Cr and Mn by high-energy ball milling of elemental powder mixtures has been studied from the scale of a powder particle down to the atomic scale using X-ray and neutron diffraction, Mossbauer spectrometry and magnetic measurements for Fe1−xTx alloys with x=0.50, 0.65 for T=V, x=0.50, 0.70 for T=Cr and x=0.72 for T=Mn. Different alloying behaviours are observed according to T once powder particles have the final composition. The rather fast mechanical alloying of Fe with Mn reflects the statistical nature of the milling process in contrast to the slow mixing of Fe with V and of Fe with Cr. Hyperfine magnetic field distributions remain stationary in shape in the last milling stage at room temperature both for T=V and T=Cr. Magnetic measurements evidence the persistence with milling time of a large population of nanometer-sized Fe-Cr zones that are superparamagnetic at room temperature and at 400 K. By contrast, room-temperature Mossbauer spectra show only a single line for long milling times. The unmixed stationary state of milled p-Fe0.7Cr0.3 is discussed in the light of a recent model of systems driven by competing dynamics.

Phase diagrams of bcc alloys at low temperatures with ballistic atom movements.

Kinetic Monte Carlo simulations were used to determine the steady states of equiatomic bcc alloys with first- and second-nearest-neighbor (1NN and 2NN) effective pair interactions. Atom movements occurred with a vacancy mechanism, and were of two types: thermal and ballistic. The phase diagram in the space spanned by the 1NN and 2NN interaction strengths was determined for thermal atom movements alone, and with some ballistic atom movements. With increasing temperature, the region of B32 phase receded against the adjacent regions of B2 order and unmixed states. With some ballistic atom movements, however, the region of B32 order encroached on the adjacent regions of B2 order and unmixed state. The shifts in phase boundaries are attributed to differences in how the internal energies of the different phases are affected by ballistic atom movements. Local fluctuations in the internal energy density in the presence of ballistic atom movements caused two-phase regions in the phase diagram.

Reply to Greg Holloway

HOLLOWAY (1993, hereafter GH) states that YAMAZAKI and KAMYKOWSKI (1991, hereafter YK) used a random walk model inconsistent with the continuity condition of an incompressible fluid. Because a spatial dependence of diffusivity induces an advectionlike effect, YK's formulation results in unmixed state from a completely mixed state. Based on his mathematical reasoning GH is correct. However, one must be careful in making comments on an immature subject since it may put constraints on creative thinking. We argue that GH's comments are not appropriate for the following reasons: (1) GH does not consider the bottom line of our work; (2) GH does not mention the theories of stochastic differential equations. As we clearly stated in YK, our original intent was to investigate the spatial dependence of the diffusivity effect from a Lagrangian point of view because previous studies traditionally were based on Eulerian modelling and almost always used a constant diffusivity coefficient. We did not propose our model as a perfect solution to bio-physical coupling problems. Also, we did not claim that the way the initial cluster of particles dispersed into the resulting trajectories or distributions (not aggregations as stated by GH) necessarily was right. Instead, we merely hoped that our model would serve as a reference point for future development. GH criticizes a minor inconsistency in our Lagrangian random walk model and does not consider how much this mathematical problem alters the final conclusions. Although GH claims that our formalism is incorrect, we disagree with his reasoning. In YK, we avoided the details of random walk theories in order to focus the application on the bio-physical coupling problem. We now mention why equation (2) of YK, namely,

Stability of the periodic decomposition structure in Cu-Ni-Fe alloys under irradiation

The influence of irradiation on the morphology and kinetics of decomposition of Cu-Ni-Fe alloys within the miscibility gap has been investigated. These alloys decompose into a periodic two phase structure with a characteristic length which can be controlled by thermal treatment to between 2 and 20 nm. The paper treats the relevance of the primary knock-on energy for the irradiation effect on the decomposition structure and kinetics. The alloys were irradiated with 150 keV protons and 300 keV Cu + ions. The irradiation effect consisted of an enhancement of the decomposition rate for the proton case and resolution of the unmixed state for Cu ions. A model for the radiation effects considers radiation enhanced diffusion as the cause for unmixing of the alloy and cascade mixing as the cause for resolution of the unmixed state. Quantitative evaluation of the data yields an effective spheric volume of precipitate resolution having a radius of 2.6 nm.

Visualization of interfacial urethane polymerizations by means of a new microstage reactor

Mixing activated polymerizations, such as RIM urethane polymerizations, may evolve from an imperfectly mixed state; this can drastically modify the characteristics of the polymer formed. Here we focus on the basic building block of the unmixed state: a single interface between reactive monomers. We present a reactor which allows the visualization of the inerface by using an optical microscope and use it to document a variety of phenomena for two and three component urethane polymerizations: (1) the interface may or may not be stable, producing fingering, roll cells, or spontaneous generation of interfacial area, (2) different types of domains (e.g. crystalline or phase-separated) may be formed on opposite sides of the interface, and (3) hard and soft domains may be segregated for the three component polymerization due to diffusional effects.

Mixing of tt-bar bound states with the Z boson.

We take seriously the possibility that tt-bar bound states are within several GeV/c/sup 2/ of the Z-boson mass and make a careful study of this possible near degeneracy using the mass-mixing formalism. Most of the decay width of vector states below the open-top threshold comes from mixing with the Z. In the idealized situation where there is no coupling of the unmixed tt-bar state to e/sup +/e/sup -/ and ff-bar, the amplitude for e/sup +/e/sup -/..-->..ff-bar has an exact zero at the unmixed mass. Correspondingly, in the physical situation of nonzero couplings, the cross section for e/sup +/e/sup -/..-->..ff-bar exhibits deep minima. We investigate as well the effects of complex mixing matrix elements above the open-top threshold, and calculate longitudinal polarization and forward-backward asymmetries, where there are large enhancements near tt-bar resonance masses.

The effects of the dynamical Jahn-Teller interaction on the EPR of shallow acceptors in GaP

Morgan (1) has shown that as a result of the dynamical Jahn-Teller interaction each of four components of the Γ 8 valence band in a cubic semiconductor is mixed with other components by lattice distortions of symmetry E( Γ 3) and T 2( Γ 5). The resultant vibronic state has the same symmetry as the unmixed state ( gG 8) but shows different paramagnetic behavior. The g values of the EPR spectrum depend on the strength of the dynamical Jahn-Teller interaction. The effective strength of the interaction can be varied by application of a uniaxial stress. We have carried out EPR measurements on single crystals of GaP doped with C, Zn and Cd acceptors and determined both the isotropic and anisotropic g values as functions of the applied uniaxial stress. Their variation is consistent with the theory of Morgan (1) when we assume that for the shallower acceptors C and Zn, the coupling is predominantly from lattice distortions of symmetry E( T 3) whereas the comparatively deeper acceptor Cd is more strongly coupled to lattice distortions of T 2( Γ 5) symmetry.