Asymptotics,Saturation Fronts,and High Resolution Reservoir Characterization

Using an asymptotic methodology we formulate a fast, accurate algorithm for the inversion of multi-phase flow data. The approach is appropriate for many common reservoir production strategies such as CO₂ and water flooding. The technique compares well to a purely numerical method with a significant reduction in computation time. In an application to fractional flow data from the North Robertson field in West Texas, 100,000 permeability and porosity parameters are determined on a workstation. Generally, higher permeability, approaching 1milli-Darcy, is found in the eastern portion of the reservoir. The permeability estimates agree with type curve analysis for material and volumetric balances and a previous numerical pilot-point inversion.     

A Computational Intelligence-Based Genetic Programming Approach for the Simulation of Soil Water Retention Curves

Soil water retention curves are a key constitutive law used to describe the physical behavior of an unsaturated soil. Various computational modeling techniques, that formulate retention curve models, are mostly based on existing soil databases, which rarely consider any effect of stress on the soil water retention. Such effects are crucial in the case of swelling soils. This study illustrates and explores the ability of computational intelligence-based genetic programming to formulate the mathematical relationship between the water content, in terms of degree of saturation, and two input variables, i.e., net stress and suction for three different soils (sand–kaolin mixture, Gaduk Silt and Firouzkouh clay). The predictions obtained from the proposed models are in good agreement with the experimental data. The parametric and sensitivity analysis conducted validates the robustness of our proposed model by unveiling important parameters and hidden non-linear relationships.     

Mitochondria‐Targeting Oxidovanadium(IV) Complex as a Near‐IR Light Photocytotoxic Agent

Oxidovanadium(IV) complexes [VO(L¹)(phen)] ? Cl ( 1 ) and [VO(L²)(L³)] ? Cl ( 2 ), in which HL¹ is 2‐{[(benzimidazol‐2‐yl)methylimino]‐methyl}phenol (sal‐ambmz), HL² is 2‐[({1‐[(anthracen‐9‐yl)methyl]‐benzimidazol‐2‐yl}methylimino)‐methyl]phenol (sal‐an‐ambmz), phen is 1,10‐phenanthroline and L³ is dipyrido[3,2‐a:2′,3′‐c]phenazine (dppz) conjugated to a Gly‐Gly‐OMe dipeptide moiety, were prepared, characterized, and their DNA binding, photoinduced DNA‐cleavage, and photocytotoxic properties were studied. Fluorescence microscopy studies were performed by using complex 2 in HeLa and HaCaT cells. Complex 1 , structurally characterized by X‐ray crystallography, has a vanadyl group in VO₂N₄ core with the VO²⁺ moiety bonded to N,N‐donor phen and a N,N,O‐donor Schiff base. Complex 2 , having an anthracenyl fluorophore, showed fluorescence emission bands at 397, 419, and 443 nm. The complexes are redox‐active exhibiting the V(IV)/V(III) redox couple near ?0.85 V versus SCE in DMF 0.1 M tetrabutylammonium perchlorate (TBAP). Complex 2 , having a dipeptide moiety, showed specific binding towards poly(dAdT)₂ sequence. The dppz‐Gly‐Gly‐OMe complex showed significant DNA photocleavage activity in red light of 705 nm through a hydroxyl radical (^.OH) pathway. Complex 2 showed photocytotoxicity in HaCaT and HeLa cells in visible light (400–700 nm) and red light (620–700 nm), however, the complex was less toxic in the dark. Fluorescence microscopy revealed the localization of complex 2 primarily in mitochondria. Apoptosis was found to occur inside mitochondria (intrinsic pathway) caused by ROS generation.     

A solution-processable electron acceptor based on diketopyrrolopyrrole and naphthalenediimide motifs for organic solar cells

A novel, solution-processable small molecular electron acceptor (HP1) based on diketopyrrolopyrrole and naphthalenediimide fragments was designed and synthesized via a Stille coupling reaction, characterized by spectroscopic means, and exhibited excellent solubility and thermal stability. HP1 exerted strong and very broad absorption tailing into the near infra-red region, with appropriate energy levels matching with the archetypal electron donor, poly(3-hexylthiophene) (P3HT), and afforded 1.02% power conversion efficiency with a high open-circuit voltage (1.05 V) when tested in solution-processable bulk-heterojunction devices.     

Impact of NDI-Core Substitution on the pH-Responsive Nature of Peptide-Tethered Luminescent Supramolecular Polymers

The pH-responsive nature of two self-assembled NDI-peptide amphiphile conjugates is reported. The diethoxy substituted NDI showed a pH-dependent assembly behaviour, as expected. In contrast, the isopropylamino- and ethoxy-substituted NDI based supramolecular polymer was stable at acidic and basic aqueous conditions. This finding highlights how subtle changes in the molecular design of π-stacked chromophore-peptide conjugates have a drastic impact on their equilibrium structure and ultimately functional properties.     

On invariant convex cones in simple Lie algebras

This paper is devoted to a study and classification ofG-invariant convex cones ing, whereG is a lie group andg its Lie algebra which is simple. It is proved that any such cone is characterized by its intersection withh-a fixed compact Cartan subalgebra which exists by the very virtue of existence of properG-invariant cones. In fact the pair (g,k) is necessarily Hermitian symmetric.     

Palladium-catalyzed cyanation of aryl halides using K4[Fe(CN)6] as cyanide source, water as solvent, and microwave heating

A methodology for the cyanation of aryl iodides and activated aryl bromides is reported using water as the solvent and K₄[Fe(CN)₆] as the cyanide source. Reactions are complete within 20 min.     

Caught in Action: Visualizing Dynamic Nanostructures Within Supramolecular Systems Chemistry

Supramolecular systems chemistry has been an area of active research to develop nanomaterials with life-like functions. Progress in systems chemistry relies on our ability to probe the nanostructure formation in solution. Often visualizing the dynamics of nanostructures which transform over time is a formidable challenge. This necessitates a paradigm shift from dry sample imaging towards solution-based techniques. We review the application of state-of-the-art techniques for real-time, in situ visualization of dynamic self-assembly processes. We present how solution-based techniques namely optical super-resolution microscopy, solution-state atomic force microscopy, liquid-phase transmission electron microscopy, molecular dynamics simulations and other emerging techniques are revolutionizing our understanding of active and adaptive nanomaterials with life-like functions. This Review provides the visualization toolbox and futuristic vision to tap the potential of dynamic nanomaterials.     

Complex solitary waves and soliton trains in KdV and mKdV equations

We demonstrate the existence of complex solitary wave and periodic solutions of theKorteweg-de Vries (KdV) and modified Korteweg-de Vries (mKdV) equations. The solutions ofthe KdV (mKdV) equation appear in complex-conjugate pairs and are even (odd) under thesimultaneous actions of parity (??) and time-reversal (??) operations. The corresponding localized solitons arehydrodynamic analogs of Bloch soliton in magnetic system, with asymptotically vanishingintensity. The ????-odd complex soliton solution is shown to beiso-spectrally connected to the fundamental sech² solution through supersymmetry. Physically, thesecomplex solutions are analogous to the experimentally observed grey solitons of non-liner Schödinger equation, governing the dynamics of shallow waterwaves and hence may also find physical verification.     

Metal-based netropsin mimics showing AT-selective DNA binding and DNA cleavage activity at red light

Copper(II) bis-arginate [Cu(l-arg)2](NO3)2 (1) and [Cu(l-arg)(phen)Cl]Cl (2) as mimics of the minor-groove-binding natural antibiotic netropsin show preferential binding to the AT-rich region of double-stranded DNA. The complexes with a d-d band near 600 nm display oxidative DNA cleavage activity on photoirradiation at UV-A light of 365 nm and at red light of 647.1 nm (Ar-Kr laser) in a metal-assisted photoexcitation process forming singlet oxygen (1O2) species in a type-2 pathway.