Miracle-dz/UniFAR-FTUs huggingface dataset:
Electroactivity of Polyaniline Multilayer Films in Neutral Solution and Their Electrocatalyzed Oxidation of β‐Nicotinamide Adenine Dinucleotide

In this paper, we report an alternative simple method to shift the electroactivity of polyaniline (PANI) films to neutral pH conditions by forming multilayer assemblies with poly(anions) using the layer‐by‐layer (LBL) deposition method. A series of self‐assembled PANI multilayer films with poly(anions), such as sulfonated polyaniline (SPANI), poly(acrylic acid) (PAA), poly(vinyl sulfonate) (PVS), and poly(styrene sulfonate) (PSS), were prepared by the LBL method. Their electrochemical behavior and catalytic ability for the oxidation of β‐nicotinamide adenine dinucleotide (NADH) in neutral solution were investigated by electrochemistry (EC) combined with surface plasmon spectroscopy (SPS) and the quartz crystal microbalance (QCM) technique. Results indicated that all the films showed very good stability, reversibility, and electroactivity in neutral solution. All the multilayer films can electrocatalyze the oxidation of NADH, with the catalytic ability of PANI/SPANI being higher than that of the other assemblies under the same conditions. The catalytic abilities of the films with the same thickness prepared by the copolymerization method and the LBL method were also compared.
Air Drying Affects Extractable Sulfate in Soils of Variable Charge: Test of Two Extraction and Two Quantification Methods

Abstract Fertilizer recommendations need to be based on reliable soil sulfate determinations. Airdrying samples changes irreversibly many properties of soils with variable charge and might affect the extractable sulfate. In this study, sulfate extracted from air‐dry and field‐moist samples was compared. Two extracting solutions [water and 00.1 M Ca(H2PO4) 2] and two quantification methods (turbidimetry and ion chromatography) were assayed on A and B horizon samples of five Humic Acrisols from southeast Mexico. Air drying increased water‐extractable sulfate in Ah horizons, whereas in Bt horizons, it increased the 00.1 M Ca(H2PO4)2‐extractable sulfate. Airdrying increased dissolved organic carbon contents in all samples and increased soil acidity and oxalate extractable iron in 70 and 60% of the samples, respectively. Results showed larger coefficients of variation in air‐dried samples. Turbidimetry resulted less sensible than ion chromatography. To enhance sensitivity and reproducibility, particularly organic soil samples should be analyzed field‐moist and by ion chromatography.
Electrochemical Determination of Oxalate at Pyrolytic Graphite Electrodes

The electrocatalytic oxidation of oxalate at several carbon based electrodes including basal plane (BPPG) and edge plane (EPPG) pyrolytic graphite and glassy carbon (GC) electrode, was studied. The electrodes were examined for the sensing of oxalate ions in aqueous solutions and all three electrodes showed a response to oxalate additions. The peak of oxalate oxidation at BPPG electrode appeared at lower potential, +1.13 V vs. SCE, than at EPPG (+1.20 V vs. SCE) and GC electrode (+1.44 V vs. SCE). Oxalate oxidation at BPPG electrode was studied in more details for response characteristics (potential and current), effects of pH, temporal characteristics of response potential and current. The results indicated that oxalate oxidation proceeds as two-electron process at the BPPG electrode with a transfer coefficient β and a diffusion coefficient D evaluated to be 0.45 and 1.03 (±0.04)×10−5 cm2 s−1 respectively. The BPPG electrode was found to be suitable for oxalate determination in aqueous media showing linear response to oxalate concentration with a sensitivity of 0.039 AM−1 and a limit of detection of 0.7 μM.
Quantitative speciation of lead in selected mine tailings from Leadville, CO

The authors have characterized Pb speciation in selected tailings from the Leadville, CO, area using a variety of analytical techniques, including X-ray absorption fine structure (XAFS) spectroscopy. Samples from three locations were analyzed, including two chemically distinct tailings piles located within the city limits and tailings material deposited as overbank sediments along the Arkansas River approximately 13 km downstream from Leadville. Extended XAFS (EXAFS) spectra of these multicomponent samples were fit using linear combinations of model compound spectra. In accordance with pH differences among the samples, adsorbed Pb accounts for {approximately}50% of total Pb (Pb{sub T}) in fine fractions of the near-neutral pH Hamms tailings, whereas Pb-bearing jarosites account for the majority of Pb{sub T} in the fine fractions of the low pH Apache and Arkansas River tailings. EXAFS analyses following sequential extraction by MgCl{sub 2} and EDTA show evidence of significant redistribution (readsorption) of Pb during the MgCl{sub 2} extraction and for removal of adsorbed Pb and dissolution of Pb-carbonates during the EDTA extraction. Changes in Pb speciation with water extraction are observed in one sample of Arkansas River tailings. These molecular-scale results show that Pb speciation varies dramatically among environments in the Leadville area and that Pb occursmore » in a number of phases not amenable to definitive characterization by conventional microanalytical and/or chemical extraction techniques. « less
Variable precision, mixed fixed/floating point MAC unit for DNN accelerators

Artificial intelligence has become more popular than ever in past few years. Deep neural networks are being used in various use cases e.g., image processing, data analysis and etc. MAC operations are the core of DNNs thus making MAC units a very crucial element of any DNN accelerator. This paper presents a Variable precision, mixed fixed/floating point MAC unit capable of performing single precision floating-point MAC. Also, proposed MAC unit features additional modes for performing one 32-bit fixed-point MAC or two concurrent 16-bit fixed-point MACs or four concurrent 8-bit fixed-point MACs. Aside from high flexibility in number precision, proposed MAC unit uses recurring Karatsuba algorithm to implement higher bit-count multiplication only by using 8-bit multiplier and 8-bit adders. Proposed MAC unit has achieved 44.64 MOPS in 32-bit floating-point, 44.64 MOPS in 32-bit fixed-point, 89.29 MOPS in 16-bit fixed-point and 178.57 MOPS in 8-bit fixed-point on FPGA board ‘NEXYS 4 DDR’ featuring XILINX ‘xc7al00tcsg324-1’ FPGA chip.
Boolean Scheme for Programming Trial Moves That Involve Molecule Insertion and Removal in Monte Carlo Simulation

A Boolean scheme is presented for programming trial moves that involve molecule insertion and removal in both grand canonical (GCMC) and Gibbs ensemble (GEMC) Monte Carlo simulation methods. The Boolean scheme makes use of logical data type arrays for keeping track of molecules being inserted and removed, instead of the integer index array technique of the traditional Nicholson's scheme. An exploratory evaluation of the relative computational performance of the two schemes is presented. For GCMC simulation of simple fluids, Nicholson's scheme appears to be more efficient than the Boolean scheme. In contrast, for GEMC simulation of vapor-liquid equilibria (VLE) in binary systems, the Boolean scheme seems to become more efficient as the complexity of the intermolecular potential increases. However, considering the limitations intrinsic to any evaluation of computational performance, the two schemes should be regarded as alternative tools to be tried for the particular application of interest to the user.
Photostop: production of zero-velocity molecules by photodissociation in a molecular beam

Photostop is an accessible technique capable of producing atoms or molecules at a standstill in the laboratory frame. Starting with a NO2/Xe molecular beam with a mean velocity of 415 m s−1 and a longitudinal translational temperature of 6 K, NO2 molecules are photodissociated to yield NO(X ) fragments with a recoil speed equal to the molecular beam speed. The fraction of NO fragments that recoil opposite to the molecular beam are produced with a 6 K longitudinal velocity distribution centred at zero. The NO molecules are allowed to ‘evaporate’ from the probe volume by waiting for 10 µs and the molecules left behind are probed with a translational temperature of 1.6 K along the molecular beam axis and an estimated density of 107 cm−3 per quantum state. Through the choice of suitable precursors, the photostop technique has the potential to extend the list of atoms and molecules that can be slowed or trapped. It should be possible to accumulate density in a trap through consecutive loading of multiple pulses. †Current address: AECL Chalk River Laboratories, Deep River ON, K0J 1J0, Canada.
BYPASS: an effective method for the refinement of crystal structures containing disordered solvent regions

A method is described for the least-squares refinement of the atomic parameters of the ordered part of a crystal structure in the presence of disordered solvent areas. Potential solvent regions are identified automatically. The contribution of the observed contents to the total structure factor is calculated via a discrete Fourier transformation, and incorporated in a further least-squares refinement of the ordered part of the structure. The procedure is iterated a few times to convergence. It is found that this mixed discrete-atom and continuous solvent-area model refinement approach greatly improves the quality of discrete atomic parameters, i.e. the geometry and the e.s. d. 's. An electron count over the solvent region in the final difference electron-density map provides a convenient estimate for the number of solvent molecules present in the unit cell. The application of the method to four structures is described.
Cholinesterases in Biorecognition and Biosensors Construction: A Review

Acetylcholinesterase and butyrylcholinesterase are the only two known cholinesterases. Acetylcholinesterase plays an important part in cholinergic system. It terminates neurotransmission by hydrolysis of transmitter acetylcholine. The role of butyrylcholinesterase is not well understood. It is able to detoxify several compounds such as cocaine, succinylcholine, and so forth. The current review is focused on the application of cholinesterases in biorecognition. Cholinesterases are important markers in the body. Butyrylcholinesterase activity in plasma can serve as a liver function test or specific marker for sensitivity to myorelaxants or liver carcinoma. Both cholinesterases can serve as markers of poisoning by some neurotoxic compounds. Nerve agents (sarin, soman, tabun, VX), some Alzheimer disease drugs (galantamine, huperzine, donepezil, rivastigmine), pesticides (carbofuran, trichlorfon, paraoxon, malaoxon), and natural toxins (aflatoxin, pyridostigmine) can act as inhibitors of butyrylcholinesterase and/or acetylcholinesterase. Devices filled with immobilized cholinesterases can be used for the assay of the aforementioned toxins. In this review, methods for examination of cholinesterases activity in the body and in analytical devices are described. Applications, types of diagnosis, and assays are described as well.
Semibatch styrene suspension polymerization processes

Emulsion and suspension polymerization processes have widely been studied for more than 40 years. Although both polymerization processes are performed in heterogeneous media, each one presents its own typical characteristics, such as the particle size distribution, molecular weight distribution, polymer particle nucleation rate, and polymerization rate. In this study, semibatch styrene suspension polymerizations were carried out with feed compositions typical of emulsion processes. The initial reactor charge resembled the recipe of standard styrene suspension polymerizations, and the emulsion polymerization constituents were added during the batch. The influence of the moment at which the emulsion feed was started on the course of the polymerization and the effects of the feed on the polymer properties were analyzed. The polymer particle morphology and the average molecular weights changed very significantly with the emulsion feed time, and the changes could lead to the production of broad molecular weight distributions. Core–shell polymer particles could also be obtained, with the core being formed of polymer particles originating from the suspension polymerization process and the shell being formed of polymer particles originating from the emulsion polymerization. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3021–3038, 2003
Stable 5G Time Domain Resource Configuration for Synchronous Timing Services via Lyapunov Aided DRL

The high-precision clock synchronization is pursued with the consideration of the balance for time-domain resource utilization, when 5G technologies are expected to carry the timing services. Firstly, a clock synchronization model is established in the case that the system exists the observed value loss. The probability distribution of the loss of the observed value is evaluated by a newly proposed delay deterministic confidence method. Then, the error boundness of the clock synchronization is investigated by the Kalman filter algorithm, and the optimization problem for 5G time-domain resource configuration is formulated with guaranteeing the precision of clock synchronization; Finally, the proposed optimization problem is solved by dueling double deep Q-learning-based Lyapunov optimization. The experimental results verify the effectiveness and superiority of the proposed method in terms of the joint optimization of clock synchronization error covariance and throughput.
In-situ monitoring of atmospheric pressure tin oxide CVD using coherent anti-Stokes Raman scattering

Coherent anti-Stokes Raman scattering (CARS) has been used to investigate the mechanisms involved in the atmospheric pressure chemical vapour deposition (CVD) of tin oxide films on glass using dimethyltindichloride (DMT) and oxygen and/or water at 645°C. A novel compact CARS experimental system which operates using a collinear sampling geometry was designed and constructed around a conventional Nd:YAG/dye laser combination. This system facilitates the sampling of gas phase species at specific points within the reactor. This high spatial resolution has been used to investigate the variation in concentration of a major reaction product, methane as a function of position within the reactor. In addition, we report on the likelihood of detection of methyl radicals, which are believed to form via the decomposition of DMT, under growth conditions and the use of CARS in probing the gas-phase temperature within the reactor in an entirely non-invasive manner via analysis of the vibration-rotation structure of the CARS spectra associated with the N 2 process gas.
Mobilization of ferric iron from a calcareous soil by plant‐borne chelators (Phytosiderophores)

Abstract After labelling a calcareous soil with 59Fe, the mobilization of labelled Fe by root exudates of Fe‐deficient barley plants (Hordeum vulgare L.) was studied in vitro at pH 7.4 in short term experiments of up to 48 h. These root exudates contain chelators (phytosiderophores) which form stable FeIII chelates (ferrated phytosiderophores) . Compared to the control (CaSO4), the mobilization rate of labelled Fe within the first 16 h. was increased by phytosiderophores (10‐5M) by a factor between 10 and 20. At chelator concentrations of 10‐5M, the microbial siderophore, Desferal (ferrioxamine B methane sulfonate), was somewhat more effective than phytosiderophores in mobilization of labelled Fe, whereas the synthetic chelator DTPA (diethylenetriamine pentaacetic acid) was ineffective under these conditions. Decreasing the accessibility of 59FeIII at the soil surface by shaking the labelled soil with increasing phosphate concentrations substantially decreased the amount of labelled Fe mobilized by phytos.
Supercritical antisolvent micronization of natural carotene by the SEDS process through prefilming atomization

Natural carotene is micronized by the SEDS process through prefilming atomization (SEDS−PA) with the aim of evaluating the efficiency of prefilming atomization, examining the variation of carotene purity induced by the SEDS−PA process and studying the influence of operating variables on the particle size (PS) of the carotene precipitates. The carotene/dichloromethane solution to be atomized is driven through a liquid distributor with spiral slots in the prefilming atomizer as a thin film swirling at 45°. At the exit of the atomizer, the atomizing supercritical CO2 (SC-CO2) stream impinges on the film at 45°. Through the impingement and the use of swirling, the annular solution film is disintegrated into fine drops, and the mixing of the SC-CO2 and solution is intensified. Compared to the process in which solution is driven through the inner capillary of the atomizer while SC-CO2 is driven through its annular passage, the SEDS−PA process can obtain smaller droplets and finer microparticles with a narrower .
Interaction Between Lu Cations And 2:1 Aluminosilicates Under Hydrothermal Treatment

Smectites are considered to be an important component in backfill barriers due to their marked swelling and high cation exchange capacity. Both properties are affected considerably when these clays transform under natural conditions. However, we have recently described a chemical interaction between high-activity radionuclide simulators and smectites which could prove to be effective at immobilizing radionuclides definitively. Investigating the efficiency of this mechanism, independent of bentonite ageing, is a challenge. For this purpose, the reactivity shown by a non-expandable layered aluminosilicate, muscovite, has been compared to that shown by an expandable one, beidellite. Both samples were treated hydrothermally with a solution of lutetium nitrate, and the transformations were studied by X-ray diffraction, nuclear magnetic resonance and scanning electron microscopy/energy dispersive X-ray analysis. Lutetium cations react with the silicon framework of both 2:1 layered aluminosilicates under hydrothermal conditions, and new phases, lutetium disilicate, kaolinite, boehmite and natrosilite are generated. The results demonstrate that the efficiency of the chemical mechanism is not determined by the swelling and the cation exchange capacity of 2:1 layered aluminosilicates. Thus, the rare earth disilicate formation might account for the success of the clay barrier, once bentonite has lost its swelling and cation exchange capacity.
Drug Discovery: A History (Sneader, Walter)

Sneader’s expertise in pharmacy and medicinal chemistry is put to good use as he weaves the story of the development of therapeutic drugs from the beginning of human history. The book is written to appeal to a general audience, but certainly its complete and comprehensive presentation would satisfy even a specialist in medicinal and pharmaceutical chemistry.
Application of synthetic jets to low Reynolds number biosensor microfluidic flows for enhanced mixing: a numerical study using the lattice Boltzmann method

The concept of macro scale synthetic jets has been applied to the low Reynolds number channel flows associated with biosensor microfluidics. The current numerical investigation utilizes a hybrid approach of the lattice Boltzmann method for flow field computations and the convection-diffusion equation for passive scalar transport. The study presents results for various synthetic jet geometries, jet inlet conditions, scaling issues and Reynolds numbers. The results indicate limited effects due to synthetic jet cavity-slot geometry and that the synthetic jet imparts momentum to the channel flow thus enhancing fluid mixing.
Emotions Studied by Computer Scientists and Psychologists — A Complementary Perspective

Affective scientists from different fields work together to describe, understand, and harness human emotions. One specific collaboration between computer scientists and psychologists created the new field of affective computing. Computer scientists bring to the field perspective resulting from education in Physical Sciences and Engineering, whereas psychologists from Social Sciences and Humanities. This article first addresses three issues in studying emotions that are usually approached differently in psychology and computer science: defining emotions, ethical considerations, and exploring emotional data. With the bibliometric data, we show that interdisciplinary teams are exceptions, which may limit the scope of research on emotions. Next, we argue that presented different perspectives complement rather than exclude each other. Thus, we advocate for creating multidisciplinary initiatives that bring unique benefits. Our perspective provides an additional impulse to bring our fields together and encourage multidisciplinary discussions on advancing the science of emotions.
A new cyclic N-halamine biocidal polymer

A new biocidal polymer is described. The compound, poly(1,3-dichloro-5-methyl-5-(4'-vinylphenyl)-hydantoin), is prepared in a three-step synthesis from commercial polystyrene. It is insoluble in water and common organic solvents and acts as a contact biocide for contanainated water or air flowed through it. It does not leach organic impurities or levels of free chlorine greater than 1 part per million into flowing water and, thus, may represent a innovation in disinfection technology
A series of 1D, 2D and 3D coordination polymers based on a 5-(benzonic-4-ylmethoxy)isophthalic acid: syntheses, structures and photoluminescence

Seven new coordination polymers, namely, [Zn(HL)(H2O)] (1), [Zn(HL)(phen)]·1.5H2O (2), [Zn(HL)(L1)] (3), [Zn2(HL)2(L2)2]·2H2O (4), [Zn(HL)(L3)0.5] (5), [Zn(HL)(L4)] (6) and [Cu2(L)(OH)(H2O)]·0.5H2O (7) (H3L = 5-(benzonic-4-ylmethoxy) isophthalic acid, phen = 1,10-phenathroline, L1 = 1,2-bis(1,2,4-triazole-1-yl)ethane, L2 = 1,3-bis(1,2,4-triazole-1-yl)propane, L3 = 1,6-bis(1,2,4-triazole-1-yl)hexane and L4 = 4,4′-bis(1,2,4-triazole-1-ylmethyl)biphenyl), have been hydrothermally synthesized and characterized by single-crystal X-ray diffraction. In compounds 1–6, the H3L ligand is partially deprotonated to form HL2−, while it is completely deprotonated in 7. Compound 1 shows a 3D framework with 4-connected (42·7·83)2 topology. Compound 2 displays a 1D ribbon structure. The neighboring ribbons are further linked by hydrogen-bonding interactions to form a 3D supramolecular architecture. Compound 3 exhibits a 2D undulated sheet. The sheets are further penetrated into each other to give rise to a 3D polycatenation structure. Compound 4 displays a 2D supramolecular layer structure. Compound 5 shows a 3D (3,6)-connected (4·8)(4·82·103) net. Compound 6 reveals a 3D four-fold interpenetrating diamondoid architecture. Compound 7 displays a (3,8)-connected (4·62)(44·68·812·104) topology. These compounds have been characterized by powder X-ray diffractions (PXRD) and thermal gravimetric analyses (TGA). In addition, the photoluminescent behaviours of 1–6 have been investigated in detail.
Nonlinear Low-level Controller Design for an Autonomous Surface Vehicle

Autopilots are widely used in modern marine crafts; they can help skippers maneuvering their vehicles as desired. This paper presents an approach for controlling the heading and the speed of an ASV, which are designed using Lyapunov theory. The proposed autopilot is developed according to a vessel dynamic model with three degrees of freedom which is inspired from Fossen's model. The developed heading controller is validated by simulation to prove its effectiveness.