A similarity theory of approximate deconvolution models of turbulence

We apply the phenomenology of homogeneous, isotropic turbulence to the family of approximate deconvolution models proposed by Stolz and Adams. In particular, we establish that the models themselves have an energy cascade with two asymptotically different inertial ranges. Delineation of these gives insight into the resolution requirements of using approximate deconvolution models. The approximate deconvolution model's energy balance contains both an enhanced energy dissipation and a modification to the model's kinetic energy. The modification of the model's kinetic energy induces a secondary energy cascade which accelerates scale truncation. The enhanced energy dissipation completes the scale truncation by reducing the model's micro-scale from the Kolmogorov micro-scale.     

Multielement analysis and antioxidant capacity of Merlot wine clones developed in Montenegro

The overall aim of this paper was to compare the multielement composition and antioxidant capacity of two Montenegrin Merlot wines obtained from specific vine clones (VCR1 and VCR 101) along with commercial Merlot wine throughout the consecutive vintages in 2010 and 2011. Elemental composition was analysed using inductively coupled plasma optical emission spectrometry (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS). Additionally, antioxidant capacity was assessed by cyclic voltammetry. VCR 1 wine from 2011 stood out for its elemental composition. On the other hand, antioxidant capacity of VCR 101 wines was the highest one for the both vintages. According to the experimental data obtained, all three wines are good source of essential elements and products with a significant antioxidant activity and specific geographical origin.     

Self-assembled diisocyanide monolayer films on gold and palladium

Self-assembled monolayers (SAMs) of the aromatic diisocyanides, 1,4-phenylenediisocyanide, 2,3,5,6-tetramethyl-1,4-phenylenediisocyanide, 4,4'-biphenyldiisocyanide, 3,3',5,5'-tetramethyl-4,4'-biphenyldiisocyanide, and 4,4' '-p-terphenyldiisocyanide, were prepared on gold and palladium surfaces. The SAMs were characterized by ellipsometry, polarization-modulated infrared reflection-absorption spectroscopy (PM-IRRAS), and grazing-angle attenuated total reflectance infrared spectroscopy (GATR). Based on the position of the metal-coordinated isocyanide stretching band, the SAMs on gold were found to bind in the terminal (eta(1)) geometry, while the SAMs on palladium prefer a different geometry which is possibly a triply bridging (mu(3)-eta(1)) geometry. A side-reaction of the unbound isocyanide in the SAM was identified as oxidation to an isocyanate group.     

Synthesis of the new, weakly coordinating anions [RB(C6F5)3]- (R = CH2Me, CHMe2, CH2CMe3); utilization of [HNMe2Ph][Me3CCH2B(C6F5)3] to activate zirconocene catalysts for propylene polymerization

The compound [HNMe2Ph][NpB(C6F5)3](Np =(CH3)3CCH2) reacts with dimethylzirconocenes to give active propylene polymerization catalysts which are significantly more active and give higher molecular weight polypropylene than do the catalysts obtained using B(C6F5)3; the [NpB(C6F5)3]- anion is for steric reasons more weakly coordinating than is [MeB(C6F5)3]-.     

Compound A Increases Cell Infiltration in Target Organs of Acute Graft-versus-Host Disease (aGVHD) in a Mouse Model

Systemic steroids are used to treat acute graft-versus-host disease (aGVHD) caused by allogenic bone marrow transplantation (allo-BMT); however, their prolonged use results in complications. Hence, new agents for treating aGVHD are required. Recently, a new compound A (CpdA), with anti-inflammatory activity and reduced side effects compared to steroids, has been identified. Here, we aimed to determine whether CpdA can improve the outcome of aGVHD when administered after transplantation in a mouse model (C57BL/6 in B6D2F1). After conditioning with 9Gy total body irradiation, mice were infused with bone marrow (BM) cells and splenocytes from either syngeneic (B6D2F1) or allogeneic (C57BL/6) donors. The animals were subsequently treated (3 days/week) with 7.5 mg/kg CpdA from day +15 to day +28; the controls received 0.9% NaCl. Thereafter, the incidence and severity of aGVHD in aGVHD target organs were analyzed. Survival and clinical scores did not differ significantly; however, CpdA-treated animals showed high cell infiltration in the target organs. In bulk mixed lymphocyte reactions, CpdA treatment reduced the cell proliferation and expression of inflammatory cytokines and chemokines compared to controls, whereas levels of TNF, IL-23, chemokines, and chemokine receptors increased. CpdA significantly reduced proliferation in vitro but increased T cell infiltration in target organs.     

A dispersive liquid–liquid microextraction based on a task-specific ionic liquid for enrichment of trace quantity of cadmium in water and food samples

In this work, a hydrophilic task-specific ionic liquid (TSIL) of 1-chloroethyl-3-methylimidazolium chloride functionalized with 8-hydroxyquinoline was used in a dispersive liquid–liquid microextraction method followed by flame atomic absorption spectrometry for the enrichment and determination of trace amounts of cadmium (Cd²⁺) ions. The simultaneous chelation and extraction of Cd²⁺ ions was carried out by the TSIL. Fine droplets of the water-immiscible TSIL containing target analyte were generated in situ by addition of an anion exchanger potassium hexafluorophosphate (KPF₆) salt to the sample tube. After phase separation by centrifugation for 4 min, the sedimented TSIL was diluted with acidified ethanol for measurement of Cd²⁺ content. Some significant parameters influence the preconcentration of Cd²⁺ ions such as sample pH, TSIL volume, amount of KPF₆, non-ionic surfactant and salt concentration were investigated. Under the optimal conditions, calibration curve was linear in the range of 5–250 µg L^?1 Cd²⁺ with correlation coefficient of 0.9975 and a detection limit of 0.55 µg L^?1. The relative standard deviation for six replicate measurements of 50 µg L^?1 Cd²⁺ was 1.5%. The method was successfully applied for the extraction and determination of Cd²⁺ ions in water and food samples.     

Modified polysaccharides for use in enhanced oil recovery applications

Aqueous solutions of a charged hydrophobically modified hydroxyethylcellulose (HM-HEC(−)) exhibit high viscosities even at low polymer concentrations (0.2 wt%), which is an interesting feature in connection with enhanced oil recovery. This polymer was synthesized for this work. Effects of temperature and addition of sodium dodecyl sulfate (SDS) or hydroxypropyl-β-cyclodextrin (HP-β-CD) on the viscosity properties of a semidilute solution of HM-HEC(−) are examined. The results for the HM-HEC(−)/SDS system disclose strong interactions between HM-HEC(−) and SDS at low level of SDS addition, and this leads to a significant viscosification of the polymer-surfactant mixture. At higher surfactant concentrations the association complexes are disrupted. A strong temperature effect of the viscosity is observed at moderate levels of SDS addition, with lower values of the viscosity at elevated temperatures because of enhanced polymer chain mobility that breaks up the associations. Addition of HP-β-CD monomers to the HM-HEC(−) solution generates decoupling of associations via inclusion complex formation with the polymer hydrophobic tails and the viscosity decreases. By using temperature and addition of these co-solutes, it is demonstrated that the viscosity of the polymer solution can be tuned over a large range of viscosity values.     

Stereoselective Synthesis and Structure of New Types of Calix[4]resorcinarenes. Complexation of Tetrakis(O,O‐Phosphorus)Bridged‐Calix[4]resorcinarenes with Heavy Metal Atoms

The acid‐catalyzed (with HCl) condensation reactions of resorcinol ( 1 ) with 1‐naphthaldehyde ( 2 ) and isobutyraldehyde ( 3 ) furnished the tetrameric macrocyclic compounds 4 and 6 . Detailed NMR‐investigations of the acetylated tetrameric species 5 surprisingly support a structure not in agreement with the expected all‐cis conformation. The chair conformation (C_2h symmetry) of the acetylated derivative 5 was established through a crystal X‐ray diffraction study. The naphthyl substituents are arranged in trans position above and below the plane made up by the resorcinol units. The reaction of resorcinol 1 with isobutyraldehyde, in accord with expectation, led to the calix[4]resorcinaren ( 6 ). The ¹H NMR spectra of compound 6 and 7 appeared at room temperature as broad signals, indicating a conformation of C_2v symmetry. The reaction of the C‐methyl‐tetrakis‐P‐(chlorodioxaphosphocin)‐calix[4]resorcinarenes ( 8 ) and ( 10 ) with suitable N‐trimethylsilyl organic amines were conducted in tetrahydrofuran suspension, furnishing the P–N‐substituted calix[4]resorcinarenes ( 9 ) and ( 11 ). While in the complexation of C‐methyl‐tetrabromotetrakis‐P‐(dimethylaminodioxaphosphocin)‐calix[4]resorcinarene ( 13 ) with (tht)AuCl (tht = tetrahydrothiophene) the expected, neutral tetra‐substituted complex 15 was formed, the reaction of 13 with moist acetonitrile led to the anionic atomic framework 14 . X‐ray structure determinations of the complexes 14 and 15 show that both possess the cone conformation. In the gold complex 15 , the Au–Cl groups form a loose aggregate, with three Au…Cl contacts of 316–340 pm; one of the groups points towards the centre of the cone. The copper(I) complex 14 displays crystallographic mirror symmetry, with a central Cu₄Cl₅ unit involving tetrahedrally coordinated copper.     

Application of a new potentiometric method for determination of phosphate based on a surfactant-modified zeolite carbon-paste electrode (SMZ-CPE)

A phosphate-selective electrode based on surfactant-modified zeolite (SMZ) particles into carbon-paste has been proposed (SMZ-CPE). The electrode was fully characterized in terms of composition, response time, ionic strength, thermal stability and usable pH range. The electrode containing 20% SMZ exhibited linear response range to phosphate species in the range of 1.58 × 10⁻⁵ to 1.00 × 10⁻² M with a detection limit of 1.28 × 10⁻⁵ M and a Nernstian slope of 29.9 ± 0.9 mV per decade of phosphate concentration. The electrode response to phosphate remains constant in the pH range of 4-12 and in the presence of 1 × 10⁻⁴ to 4 × 10⁻³ M NaNO₃. The response of the electrode reaches equilibrium within several seconds after immersing the electrode in phosphate solution. Common anions such as Cl⁻, Br⁻, I⁻, NO₃⁻, SO₄²⁻ and Cr₂O₇²⁻ have little effect on the determination of phosphate but AsO₄³⁻ shows some interference. A successful application of the electrode for determination of phosphate in a fertilizer, using direct potentiometry, is presented. The electrode was also used for the potentiometric titration of phosphate. The validation of the obtained results in each case was proved by statistical methods.