Improved viewing resolution of three-dimensional integral imaging by use of nonstationary micro-optics

We propose the use of synchronously moving micro-optics (lenslet arrays) for image pickup and display in three-dimensional integral imaging to overcome the upper resolution limit imposed by the Nyquist sampling theorem. With the proposed technique, we show experimentally that the viewing resolution can be improved without reducing the three-dimensional viewing aspect of the reconstructed image.     

Dispersive liquid-liquid microextraction for the analysis of three organophosphorus pesticides in real samples by high performance liquid chromatography-ultraviolet detection and its optimization by experimental design

A method was developed for analyzing the organophosphorus pesticides Fenitrothion, Diazinon and Ethion in water samples via dispersive liquid-liquid microextraction and high-performance liquid chromatography. Chloroform and methanol were selected as extraction and dispersive solvents, respectively. Extraction and dispersive solvents (and their volumes), the pH of the sample, and salting out effect were optimized to give a calibration plot that is linear in the range from 10 to 4000 ng.mL^?1. Detection limits are 2 ng.mL^?1 for Fenitrothion and 3 ng.mL^?1 for Diazinon and Ethion. The relative standard deviations for six replicate measurements of 500 ng.mL^?1 of the three pesticides are 3.3, 2.2 and 4.1%, respectively.     

Determination of oil wells productivity using multivariate FTIR data

Traditional methods for productivity surveillance of oil wells mainly are consisted of using test-separator units with expensive devices, protections, inspections, operations, facilities, infrastructures and repairing services. The objective of this work is to utilize a novel approach to predict the accurate productivity of oil wells using a single sample point at the line of blend oil. The present method is based upon performing multivariate regression of infrared spectra, which taken from the real samples of Iranian offshore oil wells. The experimental results revealed that the present approach is appropriate for precocious, quick and reliable surveillance of individual oil wells located in an oil field. The model has predicted the accurate productivity of real oil wells with respect to the current expensive techniques since 2010.     

Extraction of vanadyl porphyrins in crude oil by inclusion dispersive liquid–liquid microextraction and nano-baskets of calixarene

The novelties of this approach are introducing the self-settled dispersive liquid–liquid microextraction technique to remove the centrifuging step, conducting the dispersive liquid–liquid microextraction in complex organic systems, applicability of water as disperser phase, and inclusion microextraction of charged porphyrins by nano-baskets of calix[4]arenes, which act as the settling agents as well as the inclusion ligands. Diacid p-tert-butylcalix[4]arene in the cone conformation was synthesized and used. The related parameters including ligand concentration, volume of water disperser, salt effect, and extraction time were optimized. The linear range, detection limit (S/N?=?3) and precision (RSD, n?=?6) were determined to be 0.2–50, 0.07?μg?L^?1 and 5.3%, respectively. The established method was applied to determine the target compound in five samples of live crude oil, were sampled from an Iranian offshore field. Owing to the overall differences (such as organic media, inclusion extraction, water-soluble ligands, etc.), the comparison of the proposed method with the traditional liquid–liquid microextraction was inapplicable. These results revealed that the new approach is competitive analytical tool and an alternative of the traditional methods in the crude oil and related systems. Moreover, in those systems that the inclusion separation is not requested, it is possible to use a tertiary system including a proper extraction agent/solvent and calixarene phase, as settling agent, along with the aqueous disperser in the organic systems.     

Application of Fourier Transform Infrared in Flow Surveillance of Oil Wells

This article has been retracted.     

A study on dissociation of sII krypton hydrate and the effect of hydrocarbon guest molecules as stabilizer by molecular dynamics simulation

In this paper, the characteristics of structure II krypton hydrate are studied by molecular dynamics simulation under isobaric-isothermal (NPT) ensemble condition. The dissociation process of the hydrate is simulated and the effect of krypton (Kr) and various types of hydrocarbon guest molecules (HGMs) on the stability of the hydrate structure is investigated during the simulation time of 1 ns. The studied HGMs are propane, isobutane, neopentane, cyclopropane, cyclobutane, cyclopentane and cyclopentene. The structural change of the Kr-hydrate is analyzed with the radial distribution function, mean square displacement and diffusion coefficient. As temperature increases, the obtained results indicate a gradual increase in the Kr-hydrate cell size, which leads to distortion of the hydrate lattice and escaping of the encapsulated Kr molecules from the hydrate structure to form small bubbles of Kr aggregated in the aqueous solution.     

Application of nano-baskets in metabolomics

A novel approach for inclusion extraction and fingerprinting of metabolite was introduced base upon the emulsion liquid membrane-nuclear magnetic resonance (ELM-NMR) technique. The objective of this method is optimizing the fingerprints, minimizing the metabolic variation from analysis, increasing the likelihood differences, and obtaining the maximum extraction yield. Low molecular weight metabolites in rat serum were recovered by ELMs using three nano-baskets of calix[4]crowns-3 as emulsifier and carrier. The yields of ELMs were optimized by the method of once at a time. According to the NMR data, the maximum metabolic variation was achieved using scaffold 4 (4 wt%), n-decane membrane, stirring rate of 300 rpm, treat and phase ratios of 0.3 and 0.8, respectively. According to the NMR data, the results revealed that calixcrowns 6 and 9 tend to extract non-specific macromolecules and the repeatability of fingerprints for 4-mediated ELM was more than two others. The yield of extractions was obtained to be higher for n-decane and lower for carbon tetrachloride. Using different membrane types, the fingerprints by chlorinated liquid membranes were more repeatable than toluene or n-decane.     

Coarse Grained Molecular Dynamics Simulation of Nanoconfined Water

A coarse‐grained (CG) model for the simulation of nanoconfined water between graphene surfaces is developed. For this purpose, mixed‐grained simulations are done, in which the two‐site water model of Riniker and van Gunsteren [S. Riniker, W. F. van Gunsteren, J. Chem. Phys. 2011 , 134, 084110] is simulated between atomistically resolved graphene surfaces. In the developed pure CG model, the two interaction sites of water and a combination of eight carbon atoms in the graphene surface are grouped together to construct water and surface CG beads. The pure CG potentials are constructed by iteratively matching the radial distribution functions and the density profiles of water beads in the pore with the corresponding mixed‐grained distributions. The constructed potentials are shown to be pore‐size transferable, capable of predicting structural properties of confined water over the whole range of pore sizes, ranging from extremely narrow pores to bulk water. The model is used to simulate a number of nanoconfined systems of a variety of pore sizes at constant temperature, constant parallel component of pressure, and constant surface area of the confining surfaces. The model is shown to predict the layering of water in contact with the surfaces, and the solvation force is in complete agreement with the mixed‐grained model. It is shown that water molecules in the pore have smaller parallel diffusion coefficients compared to bulk water. Well‐organized layers beside the surfaces are shown to have lower diffusion coefficients than diffuse layers. More information on the dynamics of water in the pore is obtained by calculating the rate of water exchange between slabs parallel to the surfaces. The time scale to achieve equilibrium for this process, depending on the pore width and on the degree of layering of water beside the surfaces, is a few nanoseconds in nanometric pores.     

Digital broadband linearization technique and its application to photonic time-stretch analog-to-digital converter

Suppression of distortion induced by nonlinearity in a dynamical system (such as an analog optical link) is very challenging, particularly for a wide-bandwidth signal. Conventional compensation techniques are computationally intensive, significantly limiting their realization in real-time applications. Here, we propose and demonstrate an efficient digital postprocessing technique to suppress distortions added to a wideband signal by a nonlinear system with memory effect. Experimentally, digital broadband linearization of the photonic time-stretch analog-to-digital converter (TSADC) is demonstrated. In case of TSADC, a dynamic range improvement of >15 dB compared to conventional memory-less correction method is achieved.