Structure and phase behavior of colloidal dumbbells with tunable attractive interactions

We investigate thermodynamic and structural properties of colloidal dumbbells in the framework provided by the Reference Interaction Site Model (RISM) theory of molecular fluids and Monte Carlo simulations. We consider two different models: in the first one we set identical square-well attractions on the two tangent spheres composing the molecule (SW-SW model); in the second scheme, one of square-well interactions is switched off (HS-SW model). Appreciable differences emerge between the physical properties of the two models. Specifically, the $k \to 0$ behavior of SW-SW structure factors $S(k)$ points to the presence of a gas-liquid coexistence, as confirmed by subsequent fluid phase equilibria calculations. Conversely, the HS-SW $S(k)$ develops a low-$k$ peak, signaling the presence of aggregates; such a process destabilizes the gas-liquid phase separation, promoting at low temperatures the formation of a cluster phase, whose structure depends on the system density. We further investigate such differences by studying the phase behavior of a series of intermediate models, obtained from the original SW-SW by progressively reducing the depth of one square-well interaction. RISM structural predictions positively reproduce the simulation data, including the rise of $S(k \to 0$) in the SW-SW model and the low-$k$ peak in the HS-SW structure factor. As for the phase behavior, RISM agrees with Monte Carlo simulations in predicting a gas-liquid coexistence for the SW-SW model (though the critical parameters appears overestimated by the theory) and its progressive disappearance moving toward the HS-SW model.Comment: 12 pages, 13 figures, 1 table, 78 reference

What is the Future of Work 2022

Thanks to the collective experiences of knowledge workers over the last 24 months of the pandemic we have become better at knowing what’s best done at work, and elsewhere. Our purpose has been to understand how this plays out in the context of a more flexible work landscape. Our next generation of workforce is further accelerating the rate of change with choice and flexibility now driving the conversation and talent war. The trick is how do you manage employee expectations with what your organisation can offer. We have well and truly adjusted our workstyles. Yet we are innately social creatures that thrive with human connection. WHAT WE’VE EXPLORED IS THE SENTIMENT OF GEN Z

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Adventure photography is about going out and getting that shot that you can show people and blow them away. Currently, there are no bags that address the needs of an adventure photographer in the rigorous setting that they encounter. The Wanderer focuses on accessibility, protection and weight distribution, and is designed so you can retrieve your camera, grab the quick shot, and stow the camera away, all without the hassle of digging through your bag

Braid invariants for non-linear differential equations

Vorst, R.C.A.M. van der [Promotor]Berg, G.J.B. van den [Promotor

Verbi in serie: una prospettiva tipologica

The authors acknowledge EPSRC (EP/K503162/1) for funding this research.Na2MoO2−δF4+δ (δ ∼ 0.08) displays a unique variant of the perovskite structure, with simultaneous (Na,vacancy) ordering on the A-site, (Na,Mo) ordering on the B-site, (O,F) ordering on the anion site and an unusual NaNbO3-like octahedral tilt system.Publisher PDFPeer reviewe

Hydrides as high capacity anodes in lithium cells: an Italian “Futuro in Ricerca di Base FIRB-2010” project

Automotive and stationary energy storage are among the most recently-proposed and still unfulfilled applications for lithium ion devices. Higher energy, power and superior safety standards, well beyond the present state of the art, are actually required to extend the Li-ion battery market to these challenging fields, but such a goal can only be achieved by the development of new materials with improved performances. Focusing on the negative electrode materials, alloying and conversion chemistries have been widely explored in the last decade to circumvent the main weakness of the intercalation processes: the limitation in capacity to one or at most two lithium atoms per host formula unit. Among all of the many proposed conversion chemistries, hydrides have been proposed and investigated since 2008. In lithium cells, these materials undergo a conversion reaction that gives metallic nanoparticles surrounded by an amorphous matrix of LiH. Among all of the reported conversion materials, hydrides have outstanding theoretical properties and have been only marginally explored, thus making this class of materials an interesting playground for both fundamental and applied research. In this review, we illustrate the most relevant results achieved in the frame of the Italian National Research Project FIRB 2010 Futuro in Ricerca “Hydrides as high capacity anodes in lithium cells” and possible future perspectives of research for this class of materials in electrochemical energy storage devices

Approximate solution to a hybrid model with stochastic volatility: a singular-perturbation strategy

We study a hybrid model of Sch¨obel-Zhu-Hull-White-type from a singular-perturbationanalysis perspective. The merit of the paper is twofold: On one hand, we find boundary conditions for the deterministic non-linear degenerate parabolic partial differential equation for the evolution of the stock price. On the other hand, we combine two-scales regular- and singular-perturbation techniques to find an approximate solution to the pricing PDE. The aim is to produce an expression that can be evaluated numerically very fast

Simulation of Self-heating Process on the Nanoscale: a Multiscale Approach for Molecular Models of Nanocomposite Materials

We develop a theoretical–computational protocol to simulate Joule heating on nanocomposite materials, allowing to investigate morphology, voltage and concentration effects

1/3 magnetization plateau and frustrated ferrimagnetism in a sodium iron phosphite

AT was supported by the Federal Ministry for Education and Research through the Sofja Kovalevskaya Award of Alexander von Humboldt Foundation. This work was supported in part by Russian Foundation for Basic Research grants 14-02-00111, 14-02-00245, 16-02-00021, from the Ministry of Education and Science of the Russian Federation in the framework of Increase Competitiveness Program of NUST «MISiS» (№ К2-2015-075 and № K4-2015-020) and by Act 211 of the Government of Russian Federation, agreement № 02.A03.21.0006. EAZ, JW and RK acknowledge support by the Excellence Initiative of the German Federal Government and States. PL thanks EPSRC (EP/K503162/1) for partial support of a studentship to IM and the Leverhulme Trust for the award of a post-doctoral fellowship (RPG-2013-343) to LC. SK is grateful for the funding by SSP1458 of the DFG.The sodium-iron phosphite NaFe3(HPO3)2(H2PO3)6 is studied by ac-magnetic susceptibility, pulsed-field magnetization, specific heat, and high-frequency electron spin resonance (HF-ESR) measurements combined with Mössbauer spectroscopy and density-functional calculations. We show that this compound develops ferrimagnetic order below TC = 9.5 K and reveals a magnetization plateau at 1/3-saturation. The plateau extends to Bc ~ 8 T, whereas above Bc the magnetization increases linearly until reaching saturation at Bs ~ 27 T. The Mössbauer spectroscopy reveals two magnetically non-equivalent iron sites with the 2:1 ratio. The HF-ESR spectra are consistent with a two-sublattice ferrimagnet and additionally pinpoint weak magnetic anisotropy as well as short-range spin order that persists well above TC. The ferrimagnetic order in the title compound is stabilized by a network of purely antiferromagnetic exchange interactions. The spin lattice comprises layers coinciding with the crystallographic (10-1) planes, with stronger couplings Ji ~ 1.5 K within the layers and weaker couplings Ji = 0.3−0.4 K between the layers. Both intralayer and interlayer couplings are frustrated. The ensuing ferrimagnetic order arises from a subtle interplay of the frustrated but nonequivalent exchange couplings.PostprintPostprintPeer reviewe