Correction to: On the optimization of a vertical twisted tape arrangement in a channel subjected to MWCNT–water nanofluid by coupling numerical simulation and genetic algorithm

Journal of Thermal Analysis and Calorimetry - Lignin-based polycaprolactone (PCL) graft copolymers with various graft ratios were prepared by ring-opening reaction in order to design new lignin...     

Synthesis of Novel Dibenzylbutyrolactones as Dimethylmatairesinol Analogues

In this work, (R)‐4‐(3,4‐dimethoxybenzyl)dihydrofuran‐2(3H)‐one was prepared though an efficient and novel method starting from (S)‐5‐((benzyloxy)methyl)dihydrofuran‐2(3H)‐one. Then, it was utilized as a versatile starting material for the synthesis of novel dimethylmatairesinol analogues; dibenzylbutyrolactone derivatives, via the reaction of the later compound and various aromatic aldehydes.     

Multi-reservoir device for detecting a soluble cancer biomarker

By combining the sensing capabilities of nanoscale magnetic relaxation switches (MRS) within multi-reservoir structures, a potentially powerful implantable multiplexed sensor has been developed. MRS are magnetic nanoparticles that decrease the transverse relaxation time (T(2)) of water in the presence of an analyte. The switches encased in polydimethylsiloxane (PDMS) devices with polycarbonate membranes (10 nm pores) have demonstrated in vitro sensing of the beta subunit of human chorionic gonadotrophin (hCG-beta), which is elevated in testicular and ovarian cancer. Devices showed transverse relaxation time (T(2)) shortening by magnetic resonance imaging (MRI) when incubated in analyte solutions of 0.5 to 5 microg hCG-beta mL(-1). The decrease in T(2) was between 9% and 27% (compared to control devices) after approximately 28 h. This prototype device is an important first step in developing an implantable sensor for detecting soluble cancer biomarkers in vivo.     

Attempted syntheses of aminofluorothiophenes

It appeared that a key intermediate for 2-amino-3-fluorothiophene ( 1 ), methyl 3-fluorothiophene-2-carboxylate ( 5 ), had been prepared by a Schiemann reaction of the 3-diazonium salt ( 6 ) in xylenes. This report was not correct. Gomberg coupling products 7 with o-xylene are actually formed. We were able to prepare 5 by using special conditions for the Schiemann reaction. The hydrazide derivative of 5 failed to give 1 under Curtius reaction conditions. Two new acetamidofluorothiophene compounds were prepared using Selectfluor^TM as the fluorinating agent, but no aminofluorothiophenes 1-3 or salts could be obtained by acidic hydrolysis of either amide.     

Synthesis of mixed-donor amido/amino/siloxo ligands from symmetrical diamidosilylether ligands via a retro-Brook rearrangement and their chromium(II) complexes

The dilithio salts of two chelating diamidosilylether ligands undergo a retro-Brook rearrangement from oxygen to the amido-nitrogen, thereby directly yielding a new mixed-donor amido/amino/siloxo ligand. When reacted with chromium(II), siloxo-bridged dimers and a very strong eta(2)-(N,C(ipso)) arylamido interaction are featured.     

Biological Synthesis of Gold Nanoparticles by Fungus <Emphasis Type=Italic>Epicoccum</Emphasis><Emphasis Type=Italic>nigrum</Emphasis>

Gold nanoparticles exhibit unique optical, thermal, chemical and physical properties. The microorganisms have high potential for production of nanoparticles with wide applications. Application of fungi to produce nanoparticles is potentially exciting because of their ability to secrete large amounts of enzymes. In this study, we investigated biosynthesis of gold nanoparticles by the fungus Epicoccum nigrum isolated from Andalian gold mine in north-west of Iran. The gold nanoparticles were produced intra and extracellular by reaction of an aqueous solution of chloroauric acid with the biomass of fungus E. nigrum. The produced gold nanoparticles were in the size range of 5–50 nm in spherical and rod shapes. This is the first report on the biosynthesis of gold nanoparticles by the fungus E. nigrum.     

Propagation of waves in nonlocal porous multi-phase nanocrystalline nanobeams under longitudinal magnetic field

ABSTRACT

This article investigates wave propagation behavior of a multi-phase nanocrystalline nanobeam subjected to a longitudinal magnetic field in the framework of nonlocal couple stress and surface elasticity theories. In this model, the essential measures to describe the real material structure of nanocrystalline nanobeams and the size effects were incorporated. This non-classical nanobeam model contains couple stress effect to capture grains micro-rotations. Moreover, the nonlocal elasticity theory is employed to study the nonlocal and long-range interactions between the particles. The present model can degenerate into the classical model if the nonlocal parameter, couple stress and surface effects are omitted. Hamilton’s principle is employed to derive the governing equations which are solved by applying an analytical method. The frequencies are compared with those of nonlocal and couple stress-based beams. It is showed that wave frequencies and phase velocities of a nanocrystalline nanobeam depend on the grain size, grain rotations, porosities, interface, magnetic field, surface effect and nonlocality.     

An equation of state contribution for dipolar and quadrupolar square-well fluids

A dipolar–quadrupolar contribution to the residual Helmholtz energy for a polar square well (a square well plus either a point dipole or a point quadrupole) fluid is developed based on the Padé approximation. Taking the square well system as reference, the contribution is formulated using an expansion for radial distribution function of the reference system. In addition to square well potential parameters the contribution depends only on dipole and quadrupole moments. This term is added as perturbation to a generalized equation of state for square well fluids. The results are then compared with the available simulation data in the literature. With the new equation obtained, it was possible to predict liquid–vapour equilibrium properties and critical properties of polar square well fluids more accurately than with available perturbation theories for multipolar square well systems. Application of the equation of state to a real dipolar (water) and a real quadrupolar (carbon dioxide) fluid indicated that the polar contribution greatly improved the predictions of saturation properties. Accurate prediction of critical properties for polar square well fluids remains as a challenge. This work can be useful in the development of better equations of state.     

Pitzer and Pitzer–Simonson–Clegg Modeling Approaches: Ternary HCl + 2-Propanol + Water Electrolyte System

Despite its success for modeling electrolyte thermodynamics in aqueous media, the use of the Pitzer approach for the investigation of electrolytes in nonaqueous or in mixed solvent media is still very limited. Further, a review of the literature reveals that there are no more than a few research groups who have used the exact form of the Pitzer–Simonson–Clegg (PSC) ion-interaction approach for the investigation of electrolytes in mixed solvent systems. As a continuation of our previous studies, the present investigation reports modeling of HCl in the 2-propanol + water mixed solvent system with the Pitzer, PSC and an extended form of the PSC ion-interaction approaches using the experimental potentiometric data from a cell containing pH glass membrane and Ag/AgCl electrodes. The electrochemical measurements were performed over the HCl molality range from 0.01 to 4.5 mol⋅kg⁻¹ in mixed 2-propanol (x%)+water (100−x%) solvents, with different solvent percent mass fractions (x%=10,20,30,40 and 50%) at 298.15±0.05 K.     

Visible light transmission properties of double metal thin gold films with sub-wavelength hole arrays

The transmission spectrum of linearly polarized visible light through double metal thin films perforated with nano-hole arrays is investigated and simulated by using the three dimensional finite-difference time-domain method. The results show that the transmission spectra can be controlled by changing the longitudinal interval G between films and, their lateral displacements L_x and L_y, which are parallel and perpendicular to the polarization direction of the incident light, respectively. We have two important peaks (due to guided mode and SP mode) in these spectrums. The variation in longitudinal distance results a wavelength shift in guided mode peak of transmission spectrum while the wavelength of SP mode peak remains fixed. The lateral displacement L_x leads to the higher transmission of the guided mode peak, while the lateral displacement L_y suppresses the transmission of this peak. Here we try to discuss the physical explanations of these spectral behaviours by surface plasmon waves on the metal films and by using the concepts of surface plasma (SP) and guided modes in our double metal structure.