Simple and lowecost transition metal-free borophosphate glass catalyst for aromatic alcohol oxidation by sodium hypochlorite

The oxidation of primary and secondary alcohols to their respective aldehydes/ketones is one of the most important reactions in fine chemistry due to the industrial application of these products. Based on this, a large number of new catalysts and oxidants have been tested using this reaction as a catalytic model, mainly looking for a process that ensures high aldehyde selectivity. In this paper, we have used moisture stable borophosphate glass doped with 10 mol% Al2O3 as a heterogeneous catalyst in the oxidation of sodium hypochlorite, an effective, greener, and low-cost oxidant, using acetonitrile as solvent under mild conditions. The glass catalyst mass and the particle size were evaluated, as were the reaction temperature and oxidant amount, to determine the ideal reaction conditions where the conversions achieved 87.0 mol% for 1-phenylethanol to acetophenone and 79.4 mol% for benzyl alcohol to benzaldehyde, with benzaldehyde selectivity above 95%. Although sodium hypochlorite is a strong oxidant, benzaldehyde was the main product of the oxidation of benzyl alcohol due to the formation of a biphasic organic-aqueous system that protects the aldehyde from oxidation and allows the reaction to occur without the use of a phase transfer catalyst (PTC). HPLC analysis of both phases showed that alcohols, aldehyde, and ketone were mostly present in the organic phase (concentrations above 98.7%). During the reaction, a small amount of alcohol is transferred to the aqueous phase, where the oxidation took place. Once formed, the products are transferred back to the organic phase. ICP-OES analysis indicates that borophosphate glass acts in the reaction by partially releasing phosphate-based groups, reducing the pH of hypochlorite to 9. In this sense, borophosphate glasses prove to be a simple and inexpensive alternative for the development of new catalysts

Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

Search for supersymmetry in events with one lepton and multiple jets in proton-proton collisions at root s=13 TeV

Peer reviewe

Search for anomalous couplings in boosted WW/WZ -> l nu q(q)over-bar production in proton-proton collisions at root s=8TeV

Peer reviewe

Self-supported nickel nanoparticles on germanophosphate glasses : synthesis and applications in catalysis

The development of supported catalysts based on simple procedures without waste products and timeconsuming steps is highly desirable. In this paper, self-supported nickel-based nanoparticles were obtained at the surface of the germanophosphate glasses by bottom-up process and evaluated as potential catalysts for the benzyl alcohol oxidation and bis(indolyl)methanes synthesis. A classical meltquenching technique was used for preparing the nickel-doped germanophosphate glasses, followed by annealing under a hydrogen atmosphere at 400 C for two different times. The approach enabled the synthesis of self-supported nanoparticles as a homogeneous film, covering the glass surface. The physical and chemical properties of synthesized glasses were characterized by UV-vis and Raman spectroscopies and thermal analysis. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were performed to monitor the growth process, morphology and chemical bonding structure of the nanoparticles surface

Search for high-mass Zγ\mathrm{ Z }\gamma resonances in proton-proton collisions at s=\sqrt{s}= 8 and 13 TeV using jet substructure techniques

A search for massive resonances decaying to a Z boson and a photon is performed in events with a hadronically decaying Z boson candidate, separately in light-quark and b quark decay modes, identified using jet substructure and advanced b tagging techniques. Results are based on samples of proton-proton collisions collected with the CMS detector at the LHC at center-of-mass energies of 8 and 13 TeV, corresponding to integrated luminosities of 19.7 and 2.7 inverse femtobarns, respectively. The results of the search are combined with those of a similar search in the leptonic decay modes of the Z boson, based on the same data sets. Spin-0 resonances with various widths and with masses in a range between 0.2 and 3.0 TeV are considered. No significant excess is observed either in the individual analyses or the combination. The results are presented in terms of upper limits on the production cross section of such resonances and constitute the most stringent limits to date for a wide range of masses

Search for single production of vector-like quarks decaying to a Z boson and a top or a bottom quark in proton-proton collisions at s=13 \sqrt{s}=13 TeV

A search for single production of vector-like quarks, T and B, decaying into a Z boson and a top or a bottom quark, respectively, is presented. The search is performed using data collected by the CMS experiment at the LHC in proton-proton collisions at $\sqrt{s}=13$ TeV, corresponding to an integrated luminosity of 2.3fb$^{−1}$. An exotic T quark production mode through the decay of a heavy Z′ resonance is also considered. The search is performed in events with a Z boson decaying leptonically, accompanied by a bottom or a top quark decaying hadronically. No excess of events is observed over the standard model background expectation. Products of production cross section and branching fraction for T and B quarks from 1.26 and 0.13 pb are excluded at 95% confidence level for the range of resonance mass considered, which is between 0.7 and 1.7 TeV. Limits on the product of the Z′ boson production cross section and branching fraction, with the Z′ boson decaying to the Tt final state, are set between 0.31 and 0.13 pb, for Z′ boson masses in the range from 1.5 to 2.5 TeV. This is the first search at 13 TeV for single production of vector-like quarks in events with a Z boson decaying leptonically accompanied by boosted jets

Measurement of the semileptonic tt‾+γ \mathrm{t}\overline{\mathrm{t}} + \gamma production cross section in pp collisions at s=8 \sqrt{s}=8 TeV

A measurement of the cross section for top quark-antiquark ( $\mathrm{t}\overline{\mathrm{t}}$ ) pairs produced in association with a photon in proton-proton collisions at $\sqrt{s}=8$ TeV is presented. The analysis uses data collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 19.7 fb$^{1}$. The signal is defined as the production of a $\mathrm{t}\overline{\mathrm{t}}$ pair in association with a photon having a transverse energy larger than 25 GeV and an absolute pseudorapidity smaller than 1.44. The measurement is performed in the fiducial phase space corresponding to the semileptonic decay chain of the $\mathrm{t}\overline{\mathrm{t}}$ pair, and the cross section is measured relative to the inclusive $\mathrm{t}\overline{\mathrm{t}}$ pair production cross section. The fiducial cross section for associated $\mathrm{t}\overline{\mathrm{t}}$ pair and photon production is found to be 127 ±27 (stat+syst) fb per semileptonic final state. The measured value is in agreement with the theoretical prediction