Self-consistent quasi-particle model

Here we review the recently developed self-consistent quasi-particle model of QGP and apply it to fit the lattice QCD data on (2+1) flavor QGP.     

Fixed point theorems for generalized weakly S-contractive mappings in partial metric spaces

In this paper, we establish some unique xed point theorems for generalized weakly S-contractive with nondecreasing and weakly increasing mappings in complete partial metric space. Also, we give some examples for strengthens of our main results.     

Conic mixed-integer rounding cuts

A conic integer program is an integer programming problem with conic constraints. Many problems in finance, engineering, statistical learning, and probabilistic optimization are modeled using conic constraints. Here we study mixed-integer sets defined by second-order conic constraints. We introduce general-purpose cuts for conic mixed-integer programming based on polyhedral conic substructures of second-order conic sets. These cuts can be readily incorporated in branch-and-bound algorithms that solve either second-order conic programming or linear programming relaxations of conic integer programs at the nodes of the branch-and-bound tree. Central to our approach is a reformulation of the second-order conic constraints with polyhedral second-order conic constraints in a higher dimensional space. In this representation the cuts we develop are linear, even though they are nonlinear in the original space of variables. This feature leads to a computationally efficient implementation of nonlinear cuts for conic mixed-integer programming. The reformulation also allows the use of polyhedral methods for conic integer programming. We report computational results on solving unstructured second-order conic mixed-integer problems as well as mean–variance capital budgeting problems and least-squares estimation problems with binary inputs. Our computational experiments show that conic mixed-integer rounding cuts are very effective in reducing the integrality gap of continuous relaxations of conic mixed-integer programs and, hence, improving their solvability. This research has been supported, in part, by Grant # DMI0700203 from the National Science Foundation.     

Single Step Synthesis of MoSe2−MoO3 Heterostructure for Highly Sensitive Amperometric Detection of Nitrite in Water Samples of Industrial Areas

The present work reports a simple and single‐step hydrothermal synthesis of MoSe₂?MoO₃ composite for highly sensitive and selective electrochemical oxidation of nitrite. FESEM of the MoSe₂?MoO₃ hybrid revealed the formation of composite as laminated structure of different sizes piled up together as finger‐like MoSe₂ bars whilst other physico‐chemical characterizations (XRD, FTIR, UV‐Vis, XPS) confirmed that co‐existence of MoO₃ as a major by‐product of hydrothermal synthesis. The as‐fabricated MoSe₂?MoO₃ composite based nitrite sensor showed remarkable selectivity and reproducibility with <3s of response time, excellent sensitivity and detection limit of 10.84 A M^?1 cm^?2 (R²=0.996) and 0.1 μM, respectively, in the range of 2.5–80 μM. The obtained sensitivity can be credited to the high surface area obtained from 1T phase MoSe₂ and α phase MoO₃ as the sensing material. The developed sensor was effectively evaluated for electrochemical recognition of nitrite in the water samples (potable and tap water) gathered from an industrial area. This new and efficient MoSe₂?MoO₃ based electrode material offers a new frontier for the progress of a novel composites by simple and single‐step approach which can be used for progress of non‐enzymatic and inexpensive electrochemical sensors for a wide range of analytical applications.     

Detecting lateral interfaces with focus‐engineered coherent anti‐Stokes Raman scattering microscopy

Focus‐engineered coherent anti‐Stokes Raman scattering (FE‐CARS) microscopy is used to highlight the lateral interfaces between chemically distinct media. Interface highlighting is achieved by using a HG10 mode for the Stokes laser beam and a HG00 mode for the pump laser beam in the forward detection scheme. The spectral and the orientation dependence of FE‐CARS are found to be in agreement with theoretical predictions. A brief discussion on the relevance of this technique for imaging third‐order nonlinear susceptibility interfaces in thin samples of biological or chemical importance is presented. Copyright © 2008 John Wiley & Sons, Ltd.     

Lewis acid metal ion-exchanged MAPO-36 molecular sieve: Characterisation and catalytic activity

Magnesium aluminophosphate-36 (MAPO-36) molecular sieve was synthesised hydrothermally and subjected to wet ion-exchange with Fe³⁺, Zn²⁺, La³⁺ or Ce³⁺. They were characterised by using XRD, SEM, temperature programmed desorption (TPD) of ammonia and thermogravimetric analysis (TGA). The XRD patterns of ion-exchanged MAPO-36 exhibit similar features to that of MAPO-36, which revealed no structural degradation during ion-exchange. TPD (ammonia) showed selective ion-exchange of strong acid sites for Fe³⁺, La³⁺ and Ce³⁺ but not for Zn²⁺. Based on the results of TGA the actual species involved in the ion-exchange is suggested to be M(OH)₂⁺, which upon calcination converted to MO⁺ where M is Fe³⁺, La³⁺ or Ce³⁺. tert-Butylation of phenol was carried out in the vapour phase as a probe reaction to examine the catalytic activity of MAPO-36 and ion-exchanged MAPO-36 molecular sieves. The ion-exchanged catalysts were found to be more active than the parent MAPO-36 and also showed higher selectivity to 4-tert-butylphenol.     

Ionic liquid [Hmim]HSO4-promoted one-pot oxidative conjugate addition of sulfur-centred nucleophiles to Baylis-Hillman adducts

The first example of the one-pot oxidative conjugate addition of sulfur-centred nucleophiles to Baylis-Hillman adducts is reported. The reaction involves oxidation of Baylis-Hillman adducts with NaNO₃ in the Brønsted acidic ionic liquid [Hmim]HSO₄ to give [E]-α-cyanocinnamaldehydes followed by conjugate hydrothiocyanation/hydrosulfenylation with NH₄SCN/PhSH to afford the corresponding β-thiocyanato (or β-phenylsulfenyl)-α-cyanohydrocinnamaldehydes diastereoselectively in 76-89% yields in a one-pot procedure. After isolation of the product, the ionic liquid [Hmim]HSO₄ could be easily recycled for further use.     

A substituent directed regioselective synthesis of aryl/pyronyl pendant unusual adipate and tetrahydronaphthalene

An efficient regioselective synthesis of pyronyl pendant ethyl methylthiocarbonylalkanoates 5 has been delineated from the base catalyzed reaction of suitably functionalized 2-pyranone 1 and 2-carbethoxycycloalkanones 2, 6 through successive substitution and regioselective ring opening by in situ generated mercaptide ion. To assess the effect of C-4 substituent on regioselectivity, reactions of 6-aryl-3-cyano-4-(piperidin-1-yl)-2-oxopyran 8 with 2-carbethoxycyclohexanone 6a and 2-carbethoxy-2-methylcyclohexanone 6b were carried out separately under analogous reaction conditions but the compounds isolated were identical and characterized as 4-aryl-8-methyl-2-piperidin-1-yl-5,6,7,8-tetrahydronaphthalene-1-carbonitriles 9. Ethyl 2-(5-amino-4′-bromo-4,6-dicyanobiphenyl-3-yl)-5-methylsulfanylcarbonylpentanoate 10 has also been prepared through base catalyzed ring transformation of ethyl 2-[6-(4-bromophenyl)-3-cyano-2-oxo-2H-pyran-4-yl]-5-methylsulfanylcarbonylpentanoate 5d by malononitrile in DMF.     

Solution decomposition of the layered double hydroxide of Co with Fe: phase segregation of normal and inverse spinels

The nitrate-intercalated layered double hydroxide of Co with Fe decomposes on hydrothermal treatment to yield an oxide residue at a temperature as low as 180 degrees C. The oxide product is phase segregated into a Co(3)O(4)-type normal spinel and a CoFe(2)O(4)-type inverse spinel. Phase segregation is facilitated as decomposition in a solution medium takes place by dissolution of the precursor hydroxide followed by reprecipitation of the oxide phases. In contrast, thermal decomposition takes place at 400 degrees C. This temperature is inadequate to induce diffusion in the solid state whereby phase segregation into the thermodynamically stable individual spinels is suppressed. The result is a single-phase metastable mixed spinel oxide. This is rather uncommon in that a hydrothermal treatment yields thermodynamically stable products where as thermal decomposition yields a metastable product.     

Metal carbonates: alternative to metal oxides for supercapacitor applications? A case study of MnCO<Subscript>3</Subscript> vs MnO<Subscript>2</Subscript>

We report here the potential competency of MnCO₃ versus MnO₂ for supercapacitor applications. MnCO₃ was synthesized by a hydrothermal method using KMnO₄ as a manganese source and either sugar or pyrrole as carbon source. MnCO₃ synthesized using sugar and pyrrole as carbon source is referred hereafter as MnCO₃(s) and MnCO₃(p), respectively. The synthesized products were characterized by powder X-ray diffraction, scanning electron microscopic and transmission electron microscopic studies. Microscopic studies revealed that MnO₂ possesses micro-flower-like morphology constructed by self-assembled nano-petals. While the morphology of MnCO₃(s) is sub-micron size particles of different shape, the morphology of MnCO₃(p) is crystalline particles of 10–20 nm dia. The capacitive characteristics of MnO₂, MnCO₃(s) and MnCO₃(p) were evaluated in aqueous 0.1 M Mg(ClO₄)₂ electrolyte between 0 and 1 V using cyclic voltammetry and galvanostatic charge/discharge cycling. Specific capacitance (SC) values of 216 and 296 F g^?1 obtained for MnCO₃(s) and MnCO₃(p) are 35 and 85 % higher than SC value of 160 F g^?1 obtained for MnO₂, respectively. Besides better capacitive storage characteristics, MnCO₃(s) and MnCO₃(p) have also exhibited better rate capability and cycle life than MnO₂.