Bonds and optimizing

The present paper defines the optimal extraction window (OEW) for three-phase membrane-based liquidphase microextraction (MP-LPME) in terms of analyte polarity (log P), and anchors this to existing theories for equilibrium partitioning and kinetics. Using deep eutectic solvents (DES) as supported liquid membranes (SLM), we investigated how the OEW was affected by ionic-, hydrogen bond and π-π interactions between the SLM and analyte.

8p viginny 23-12-2022 7 3   Download

The incorporation of N -coordinated benzimidazole complexes of palladium gave high catalytic activity in the Suzuki–Miyaura coupling of aryl halides substrates. After determining the best active catalyst as 5A1, bearing the mesityl substituent on the benzimidazole ring with the Pd(II) ion, optimization studies were carried out via changing the substrate, base, time, atmosphere, and the effect of water. The DMF:H2O (4/1) and Cs2CO3 as base were found to be critical for the efficiency of the reaction yield (100%).

11p langthannam 29-12-2021 10 0   Download

Novel chiral bisoxazoline ligands based on norbornadiene were synthesized and used for the asymmetric Henry reaction. Various aromatic aldehydes were converted into chiral β -nitro alcohols with high yields and moderate to acceptable enantioselectivities under the optimized reaction conditions. The short and efficient synthesis of bisoxazoline ligands, the flexibility in ligand design, coordination to a large number of transition metals, and excellent enantioselectivity in many reactions make these ligands indispensable in asymmetric catalysis.

14p langthannam 29-12-2021 7 0   Download

Ketoprofen and isoniazid together are a potential combination of a nonsteroidal antiinflammatory drug and an antitubercular medicine to treat tuberculosis and associated symptoms like fever and fatigue. The Schiff base of isoniazid with ketoprofen is synthesized in this research. Infrared spectroscopy (IR) and X-ray diffraction (XRD) analysis of the crystal packing proved the formation of the Schiff base and the existence of N-H···O hydrogen bonds between the hydrogen-bonded dimer of the Schiff base.

23p tudichquannguyet 29-11-2021 13 0   Download

The physical and chemical properties of bimetallic nanoparticles can be optimized by tuning the particle composition. In this study, we identified CO adsorption and dissociation energetics on five Pt-Mo nanoparticles at different concentrations, the lowest energy Pt7, Pt6Mo, Pt5Mo2, Pt4Mo3, and Mo7 clusters. We have shown that the CO adsorption and dissociation energies and preferred CO adsorption sites are largely dependent on the composition of the nanoparticles.

20p tudichquannguyet 29-11-2021 3 0   Download

Researchers have studied and evaluated the effects of electrical current frequency (f = 0÷2.000 Hz) on the physicochemical properties (surface tension, dynamic viscosity, specific weight) of wastewater. The effect of electric fields on the physicochemical properties of water, allows it to identify the optimal treatment regimes that promote the intensification of various processes taking place in an aqueous medium or in the presence of water.

7p nguaconbaynhay12 13-06-2021 16 0   Download

Optimized geometries, formation energy, phonon spectra, electronic band structure, and elastic tensor calculation has ensured the energetically, dynamical and mechanical stability for the sheets. Furthermore, the theoretically found nanosheet series possess an intrinsic wide direct band gap preserving from wurtzite tetragonal-based bonding. This high symmetry wide bandgap semiconductor nanosheet series and their derivatives are expected to have broad applications in photocatalysis, and biomedicine.

10p trinhthamhodang9 10-12-2020 11 2   Download

Currently, with the disappearance of fossil energy sources, finding new alternative energy sources is very necessary such as: solar energy, wind energy, tidal energy, flow energy, ... However, these energy sources require high investment capital, large capacity, and bulky size. In circuits requiring small power sources (below 12V), it is not applicable, or only used through intermediate devices such as transformers, current transformers; Therefore, the application of energy from mechanical vibration has been proposed as an optimal measure compared to the above methods..

6p trinhthamhodang9 04-12-2020 9 0   Download

In this work, a theoretical study for platinum(II)-8-hydroxyquinoline-tetrylene complexes [{PtCl–C9H6NO}–NHEPh] (Pt–EPh) is carried out for the first time by using the density functional theory (DFT). Quantum chemical calculations with DFT and charge methods at the BP86 level with basic sets SVP and TZVPP have been perfomed to get insight into the structures and property of Pt–EPh.

8p nguaconbaynhay9 03-12-2020 18 1   Download

Our study includes the optimization of the geometries, the calculation of the binding energies and relevant vibrational frequencies along with a natural bond orbital analysis including the charges on the different atoms, the occupation of selected antibonding orbitals and the hyperconjugation energies.

8p tamynhan8 04-11-2020 8 0   Download

Tumor angiogenesis, essential for tumor growth and metastasis, is tightly regulated by VEGF/VEGFR and PDGF/PDGFR pathways, and therefore blocking those pathways is a promising therapeutic target. Compared to sunitinib, the C(5)-Br derivative of 2-pyrrolidone-fused (2-oxoindolin-3-ylidene)methylpyrrole has significantly greater in vitro activities against VEGFR-2, PDGFRβ, and tube formation.

17p vijiraiya2711 27-05-2020 11 0   Download

The simulation results show that three to five bond funds reduce standard deviation of terminal wealth by 50% and about 100 funds reduce the standard deviation by 90%. Given the annualized marginal cost of 0.13% for bond funds, bond investors should hold three to five funds. However, equity investors who want to diversify need only one to two bond funds, regardless of risk measures. Holding more than two bond funds does not reduce portfolio risk much further especially for portfolios with high equity weights.

26p covid19 19-04-2020 11 0   Download

During the first weeks of hospitalization, premature babies and their parents encounter difficulties in establishing early bonds and interactions. Only a few studies have explored what caregivers can do to meet parents' needs in relation to these interactions and help optimize them.

9p vivalanbo2711 19-03-2020 14 0   Download

In this paper we present a rigorous, yet easy to apply method that substitutes those tedious techniques and error prone procedures that are currently used in finding optimal portfolios. Our work is not to support or dispute the applicability of the Mean-Variance optimization method in finance; we simply offer a robust approach to find all the characteristics of any efficient portfolios, with or without bonds.

13p trinhthamhodang2 21-01-2020 18 0   Download

Quantitative structure-activity relationship and molecular docking studies were carried out on a series of quinazolinonyl analogues as anticonvulsant inhibitors. Density Functional Theory (DFT) quantum chemical calculation method was used to find the optimized geometry of the anticonvulsants inhibitors. Four types of molecular descriptors were used to derive a quantitative relation between anticonvulsant activity and structural properties. The relevant molecular descriptors were selected by Genetic Function Algorithm (GFA).

11p kequaidan1 16-11-2019 12 1   Download

Research results on 3D modeling of the diamond grain and its bearing layer when sintering diamond grinding wheels are provided in this paper. The influence of the main characteristics of the wheel materials and the wheel production process, namely the quantity of metallic phase within diamond grain, coefficient of thermal expansion of the metallic phase, the modulus of elasticity of bond material and sintering temperature, on the internal stresses arising in grains is investigated. The results indicate that the stresses in the grains are higher in the areas around the metallic phase.

8p kequaidan1 16-11-2019 17 0   Download

This paper focuses on those structural models with an endogenous default barrier where firms optimally choose a default boundary so as to maximize the equity value. The analysis commences to cover avowedly theoretical frameworks from pioneering works by Black-Scholes (1973) and Merton (1974) on zero-coupon debts to later extensions of those models for a more complex debt structure to include coupon perpetual bonds (Leland, 1994) and of arbitrage maturity or rolledover debts (Leland and Toft, 1996).

26p viartemis2711 22-10-2019 10 1   Download

Topic 11 - Fixed income portfolio optimization. After completing this topic, you should be able to: Manage the interest rate risk of fixed income portfolios; compute portfolio value, income, duration, convexity compute effective duration; optimize liabilities funding (pension) using duration and convexity; optimize fixed income portfolios using duration and convexity.

17p shiwo_ding8 25-06-2019 22 0   Download

We propose a dynamic stochastic accumulation model for determining optimal decision between stock and bond investments during accumulation of pension savings. Stock prices are assumed to be driven by the geometric Brownian motion. Interest rates are modeled by means of the Cox-Ingersoll-Ross model. The optimal decision as a solution to the corresponding dynamic stochastic program is a function of the duration of saving, the level of savings and the short rate.

24p vinguyentuongdanh 19-12-2018 28 0   Download

A benzothiazolium-derived colorimetric and fluorescent chemosensor (L) for detection of mercury ions has been prepared. The detection limits of the colorimetric and fluorescent method for mercury ions are 15.3 and 11.8 ppb, respectively, much lower than the reported chemosensors based on similar derivatives of benzothiazolium.

7p lamtan3547 04-11-2018 29 1   Download