We consider a well-known diffuse interface model for the study of the evolution of an incompressible binary fluid flow in a two or three-dimensional bounded domain. This model consists of a system of ...two evolution equations, namely, the incompressible Navier-Stokes equations for the average fluid velocity
u
coupled with a convective Cahn–Hilliard equation for an order parameter
ϕ
. The novelty is that the system is endowed with boundary conditions which account for a moving contact line slip velocity. The existence of a suitable global energy solution is proven and the convergence of any such solution to a single equilibrium is also established.
Adsorptive chromatography is the gold-standard process for protein purification, where different chemical ligands are attached to polymers for a specific adsorption process. Affinity-based materials ...were developed early in the history of protein purification; they require high-cost chemicals and are labor-intensive, which significantly reduced their industrial applicability.
Ionizing radiation is a cost-effective technology for polymer processing, and it shows a great potential to prepare functional materials. This article illustrates the preparation of protein adsorptive materials by radiation processing. It is shown diverse strategies based on simultaneous radiation-induced grafting polymerization (s-RIGP).
Different natural and commercial materials such as polymeric membranes, sintered polymers, cryogels, polyurethane foams, and cellulose fibers are used as trunk materials for preparing alternative protein adsorptive materials by the s-RiPG. The grafted materials were analyzed from the perspective of protein purification for industrial purposes, where adsorption capacity, hydrodynamic and mechanical properties are studied to be used with complex biological samples.
The scope of this review is about the chronologic investigations on s-RIGP technique applied to prepare materials useful for protein purification, developed in Argentina during the last twenty-five years.
•Preparation of protein adsorptive materials by simultaneous grafting.•Membrane surface modification by simultaneous grafting.•Strategies to modification of adsorption capacity and swelling by simultaneous grafting.•Role of ethanol/water radiolysis in simultaneous grafting.
We consider a system of nonlinear diffusion equations modelling (isothermal) phase segregation of an ideal mixture of
N
≥
2
components occupying a bounded region
Ω
⊂
R
d
,
d
≤
3
. Our system is ...subject to a constant mobility matrix of coefficients, a free energy functional given in terms of
singular entropy
generated potentials and
localized
capillarity effects. We prove well-posedness and regularity results which generalize the ones obtained by Elliott and Luckhaus (IMA Preprint Ser 887, 1991). In particular, if
d
≤
2
, we derive the uniform strict separation of solutions from the singular points of the (entropy) nonlinearity. Then, even if
d
=
3
, we prove the existence of a global (regular) attractor as well as we establish the convergence of solutions to single equilibria. If
d
=
3
, this convergence requires the validity of the asymptotic strict separation property. This work constitutes the first part of an extended three-part study involving the phase behavior of multi-component systems, with a second part addressing the presence of nonlocal capillarity effects, and a final part concerning the numerical study of such systems along with some relevant application.
This review is directed to researchers interested in a new point of view with relevance to nano-biomedicine. The first part covers the uses and potential of diacetylene lipid, ...1,2-bis(10,12-tricosadiynoyl)-sn-glycero-3-phosphocholine (DC8,9PC) in facilitating biological target recognition. The second part concentrates on the use of albumin as a “soft” coating for nanoparticles. This review makes comment on how fabricated nanoparticles will assist with future human health applications.
► PVDF membranes can be modified with glycidyl methacrylate (GMA) by gamma-rays induce graft polymerization method. ► The grafted membrane can be sulfonated by an epoxy opening reaction. ► Modified ...membranes have a higher number of pores and with smaller size than the unmodified one. ► Grafted membranes do not show irreversible fouling. ► Grafted membrane permeates can be directly discharged into the rivers due to the low values of COD measured.
This work describes the synthesis of charged poly(vinylidene fluoride) (PVDF) membranes. Cationic membranes were prepared by graft modification using radiation-induced polymerization. Glycidyl methacrylate (GMA) and ethylene glycol dimethacrylate (EDMA) were used as monomers and after graft polymerization the former was sulfonized with sodium sulfite. Membrane characterizations were carried out by FTIR-ATR, SEM-EDS, ionic exchange capacity, hydraulic permeability and liquid–liquid displacement. FTIR-ATR and SEM-EDS analysis revealed that increasing grafting degree increased the amount of the sulfonic group in the membranes. Sulfonated membranes showed smaller pore sizes and higher pore density than the original PVDF membrane. Oil/water ultrafiltration tests with the charged PVDF membranes showed interesting permselectivity performance; high oil retention values (
R
>
98%), low chemical oxygen demand in the permeate solution (COD
<
59
mg
L
−1). In addition, low fouling (<16.6%) and negligible irreversible fouling of the charged membranes was observed during the ultrafiltration tests.
: We apply a utility–based method to obtain the value of a finite–time investment opportunity when the underlying real asset is not perfectly correlated to a traded financial asset. Using the ...comparison principle for the associated variational inequality, we establish several qualitative properties of the optimal investment boundary, in particular its dependence on correlation and risk aversion. We then use a discrete–time algorithm to calculate the indifference value for this type of real option and present numerical examples for the corresponding investment thresholds. We verify that even in the zero correlation case, whereby none of the risk in the project can be hedged in a financial market, the paradigm of real options can still be applied to value an investment decision, since the opportunity to invest still carries an option value above its net present value. In other words, it is time flexibility itself, more than the possibility of replication, that is the source of the extra value of an investment opportunity. This value, however, quickly erodes at higher levels of risk aversion, and even more so when the project is weakly correlated to financial markets.
Robust and cost-effective stimuli-responsive polymers show prominent advantages to be integrated into detection devices. In addition, modified track-etched membranes with chemical-sensing polymers ...possess additional robustness features such as including the sensing material into sub-micron pores. In this study, we report the preparation of track-etched PET membranes with fluorescent response in direct relation to changes in the pH of the environment. Immobilised Fluorescein and Green Fluorescent Protein have been used as pH-sensor elements. The former was not sensitive to pH, while the latter had a similar pH sensitivity to that of the free protein. Modifications of track-etched membranes were carried out by grafting polymerisation initiated by the remnant radicals, a straightforward technique for selective modification of the inner wall of pores. The biosensor prepared with the fluorescent protein was able to sense the pH of a buffer solution in the range 4 to 8. Furthermore, this membrane evidenced capacity to sense the pH of the cell growth by in situ fluorescence intensity detection during E.coli cell culture in microwells.
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We construct an infinite-dimensional information manifold based on exponential Orlicz spaces without using the notion of exponential convergence. We then show that convex mixtures of probability ...densities lie on the same connected component of this manifold, and characterize the class of densities for which this mixture can be extended to an open segment containing the extreme points. For this class, we define an infinite-dimensional analogue of the mixture parallel transport and prove that it is dual to the exponential parallel transport with respect to the Fisher information. We also define α-derivatives and prove that they are convex mixtures of the extremal (±1)-derivatives.
•Introduces persistence theory techniques for dynamical systems into macroeconomics.•Models government spending, subsidies and taxation in a stock-flow consistent way.•Government spending can make ...employment uniformly weakly persistent.•The equilibrium with finite government and private debt ratios is locally stable.•Any equilibrium with infinite debt ratios and collapsing employment can be made unstable.
The basic Keen model is a three-dimensional dynamical system describing the time evolution of the wage share, employment rate, and private debt in a closed economy. In the absence of government intervention this system admits, among others, two locally stable equilibria: one with a finite level of debt and nonzero wages and employment rate, and another characterized by infinite debt and vanishing wages and employment. We show how the addition of a government sector, modelled through appropriately selected functions describing spending and taxation, prevents the equilibrium with infinite debt. Specifically, we show that, by countering the fall in private profits with sufficiently high government spending at low employment, the extended system can be made uniformly weakly persistent with respect to the employment rate. In other words, the economy is guaranteed not to stay in a permanently depressed state with arbitrarily low employment rates.
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