A simple and rapid flow injection chemiluminescence determination of cysteine with Ru(phen)3(2+)-Ce(IV) system

A new chemiluminescence system was developed for the determination of cysteine by flow injection system. This method is based on the reaction of L-cysteine with Ru(phen)3(2+) and Ce(IV) to produce chemiluminescence. The calibration curve was linear over the range 8.0x10(-7) to 4.0x10(-5) and 4.0x10(-5) to 1.0x10(-3) M with a detection limit of 7.0x10(-7) M (S/N=3). The relative standard deviation of 4.0x10(-6) M cysteine was found 3.5% (n=10). The influence of potential interfering substances was studied. The proposed method was successfully applied for the flow injection determination of cysteine in the real samples with minimum sampling rate of 90 sample/h.     

In situ high-temperature X-ray diffraction,FT-IR and thermal analysis studies of the reaction between natural hydroxyapatite and aluminum powder

Journal of Thermal Analysis and Calorimetry - The present work focuses on the study of the effects of mechanical activation on the reaction between hydroxyapatite (HAp) and aluminum metal powder...     

Porous triazine polymer: A novel catalyst for the three-component reaction

A new porous triazine-based covalent organic polymer (Triazine-COP) was prepared through the Schiff-base condensation of 2,4,6-tris(4-formyl phenoxy)-1,3,5-triazine and 4,4′-oxydianiline, under sonication. The synthesized Triazine-COP with a high surface area was stable in water and other organic solvents. In the next step, Au (III) ions were immobilized on the nitrogen-rich Triazine-COP that on the reduction with NaBH₄ produced the heterogeneous catalyst of gold clusters in nanosize (Au-NCs@Triazine-COPs). It was applied as an efficient catalyst for the A³ coupling reaction of alkynes, aldehydes with and amines. Both electron-withdrawing/releasing groups produced the corresponding propargylamines with high yields. The high activity of the Au-NCs@Triazine-COPs in this reaction was because of the nanoporous structure of the support that enables the high dispersion and an unhindered open environment for the NCs. The catalyst was reused up to 7 times without significant loss in activity.     

Virtual Materials Intelligence for Design and Discovery of Advanced Electrocatalysts

Similar to advancements gained from big data in genomics, security, internet of things, and e-commerce, the materials workflow could be made more efficient and prolific through advances in streamlining data sources, autonomous materials synthesis, rapid characterization, big data analytics, and self-learning algorithms. In electrochemical materials science, data sets are large, unstructured/heterogeneous, and difficult to process and analyze from a single data channel or platform. Computer-aided materials design together with advances in data mining, machine learning, and predictive analytics are expected to provide inexpensive and accelerated pathways towards tailor-made functionally optimized energy materials. Fundamental research in the field of electrochemical energy materials focuses primarily on complex interfacial phenomena and kinetic electrocatalytic processes. This perspective article critically assesses AI-driven modeling and computational approaches that are currently applied to those objects. An application-driven materials intelligence platform is introduced, and its functionalities are scrutinized considering the development of electrocatalyst materials for CO₂ conversion as a use case.     

Determination of <Superscript>68</Superscript>Ga production parameters by different reactions using ALICE and TALYS codes

Gallium-68 (T _1/2 = 68 min, I _β+ = 89%) is an important positron-emitting radionuclide for positron emission tomography and used in nuclear medicine for diagnosing tumours. This study gives a suitable reaction to produce ⁶⁸Ga. Gallium-68 excitation function via ⁶⁸Zn(p, n)⁶⁸Ga, ⁶⁸Zn(d, 2n)⁶⁸Ga, ⁷⁰Zn(p, 3n)⁶⁸Ga and ⁶⁵Cu(α, n)⁶⁸Ga reactions were calculated by ALICE-91 and TALYS-1.0 codes. The calculated excitation function of ⁶⁸Zn(p, n)⁶⁸Ga reaction was compared with the reported measurement and evaluations. Requisite thickness of the targets was obtained by SRIM code for each reaction. The ⁶⁸Ga production yield was evaluated using excitation function and stopping power.      

Nonlinear Degenerate Anisotropic Elliptic Equations with Variable Exponents and L1 Data

This paper is devoted to the study of a nonlinear anisotropic elliptic equation with degenerate coercivity, lower order term and L¹ datum in appropriate anisotropic variable exponents Sobolev spaces. We obtain the existence of distributional solutions.     

Well surveillance using multivariate thermal measurements

Traditional methods to measure and survey the productivity of oil wells mainly consisted of using test-separator units with expensive instrumental, mechanical, electrical, piping, and safety devices along with technical and protective inspections, repair and operation services, facilities, and infrastructures. Their inherent limitations are time and cost consuming, uncertainty of well isolation in test separator, and need to close the co-line wells, which are diminished using multivariate thermal well testing. In this study, an alternative method is presented using multivariate regression on thermal analysis data. The objective of this study, which covered three distinctive major fields of statistics, thermal analysis, and well testing, is predicting the accurate productivity of oil wells using a single sample point at the blend oil pipeline. This method is based in performing multivariate regression of thermogravimetric data obtained from the samples of Iranian offshore oil wells. The results revealed that the used model appropriate for crude oil blends, which thermal traces significantly differ from each other. The calculated error function corrected the blend equation by considering the eutectic points and catalytic pyrolysis in lower and higher temperatures, respectively. The model predicted the accurate productivity of oil wells in real samples of blend oil pipeline.     

Acoustic roles of the laryngeal cavity in vocal tract resonance

The acoustic effects of the laryngeal cavity on the vocal tract resonance were investigated by using vocal tract area functions for the five Japanese vowels obtained from an adult male speaker. Transfer functions were examined with the laryngeal cavity eliminated from the whole vocal tract, volume velocity distribution patterns were calculated, and susceptance matching analysis was performed between the laryngeal cavity and the vocal tract excluding the laryngeal cavity (vocal tract proper). It was revealed that the laryngeal cavity generates one of the formants of the vocal tract, which is the fourth in the present study. At this formant, the resonance of the laryngeal cavity (the 1/4 wavelength resonance) induces the open-tube resonance of the vocal tract proper (the 3/2 wavelength resonance). At the other formants, on the other hand, the vocal tract proper acts as a closed tube, because the laryngeal cavity has only a small contribution to generating these formants and the effective closed end of the whole vocal tract is the junction between the laryngeal cavity and the vocal tract proper.     

Thermal and tensile loading effects on size-dependent vibration response of traveling nanobeam by wavelet-based spectral element modeling

This paper presents a novel approach for size-dependent vibration response of a nanostructure under tensile and thermal loads, traveling in its axial direction at a constant velocity. The traveling nanostructure is modeled as an Euler–Bernoulli nanobeam based on modified couple stress theory. Wavelet-based spectral element model (WSEM) is performed for analyzing vibration of the system. Imposing WSEM reduces the governing partial differential equation of the system to a set of ordinary differential equations. The roles of nanobeam velocity, tensile and thermal loads on vibration and wave characteristics, and divergence/flutter instability are scrutinized by WSEM. The validity and accuracy of resulting responses are inspected by comparing with numeric values obtained from spectral element and finite element methods, and whenever possible, with those available in the literature.