Variety identification of seeds is crucial to guarantee crop quality and yield, as well as to ensure the quality and nutritional value of processed maize products. This study proposes a methodology for identifying maize seed varieties based on hyperspectral imaging (HSI) combined with deep learning. The mean spectra of the endosperm side (E1), non-endosperm side (N1), and both sides fused (F1) of maize seeds were extracted, followed by spectral pre-processing using Savitzky-Golay (SG) smoothing and multiplicative scatter correction (MSC), and feature wavelengths were selected from the spectral data using the competitive adaptive reweighted sampling (CARS) algorithm. K-nearest neighbor (KNN), decision tree (DT), support vector machine (SVM), random forest (RF), partial least squares discriminant analysis (PLS-DA), and convolutional neural networks with multi-scale feature fusion (CNN-MFF) were utilized to construct the discriminant models. The study results show that the model established using the spectra of F1 obtains better performance than E1 and N1, with an accuracy of more than 87.22 % on the prediction set. The CNN-MFF model built based on full and feature wavelengths obtained optimal results with accuracies of 97.78 % and 96.11 % on the prediction set, respectively, which proves that the CNN based on multi-scale feature fusion has better applicability and stability. In addition, visualization methods were used to demonstrate the recognition results to visualize the model's classification performance. In summary, using HSI and deep learning for the variety identification of maize seeds is feasible. The proposed method has significant potential for application in spectral analysis and can provide a reference for the online detection of seed quality in crops such as maize. Combining spectroscopic methods to analyze the distribution information of its internal nutrient elements can contribute to directing maize food processing and improving the utilization value of by-products.
Food processing and manufacture, Physical and theoretical chemistry
Gradient coil is an essential component of a magnetic resonance imaging (MRI) scanner. To achieve high spatial resolution and imaging speed, a high-efficiency gradient coil with high slew rate is required. In consideration of the safety and comfort of the patient, the mechanical stability, acoustic noise and peripheral nerve stimulation (PNS) are also need to be concerned for practical use. In our previous work, a high-efficiency whole-body gradient coil set with a hybrid cylindrical-planar structure has been presented, which offers significantly improved coil performances. In this work, we propose to design this transverse gradient coil system with transformed magnetic gradient fields. By shifting up the zero point of gradient fields, the designed new Y-gradient coil could provide enhanced electromagnetic performances. With more uniform coil winding arrangement, the net torque of the new coil is significantly reduced and the generated sound pressure level (SPL) is lower at most tested frequency bands. On the other hand, the new transverse gradient coil designed with rotated magnetic gradient fields produces considerably reduced electric field in the human body, which is important for the use of rapid MR sequences. It's demonstrated that a safer and patient-friendly design could be obtained by using transformed magnetic gradient fields, which is critical for practical use.
Physical and theoretical chemistry, Analytical chemistry
Chadha Utkarsh, Zablotny Kinga, Mallampati Aishwarya
et al.
Nanotechnology has demonstrated its potential for advancing sustainable agriculture. This article explores new advancements in nanotechnology in agriculture, including plant extraction and validation, by emphasizing nano-fertilizers, nano-pesticides, nano-biosensors, and nanoenergy recycling processes. Nanomaterials are important for the formation, transport, and degradation of soil toxins and are a fundamental starting point for various biotic and abiotic rehabilitation processes. Research on nanoparticles’ remediation applications and soil stay insufficient and are generally restricted. When integrated into agricultural systems, nanomaterials may influence the soil quality and plant development examined by setting their impacts on supplement discharge in target soils, soil biota, soil natural matter, and plant morphological and physiological reactions. The current research works show that the seed coat acts as a barrier to nanomaterial penetration, in which both the seed coat and cell wall allowed easy water passage. Additionally, the uptake, movement, and associated defense mechanisms of nanomaterials within plants have been investigated. Future research directions have been identified to further the study toward the sustainable development of nano-enabled agriculture.
Using modern ab-initio calculations, in this work, we systematically studied the intercalation of potassium atoms into a hybrid two-layer graphene/ MoS2 structure. In the course of the study, concentrations of potassium atoms were determined at which the formation energy is negative. So, in particular, when the concentration of potassium atoms (in relation to molybdenum atoms) is not more than x=0,43, formation of a layer of potassium atoms between the graphene/ MoS2 layers is energetically favorable. Beginning with the concentration of potassium atoms x>0,75, an increase in the distance between the graphene and MoS2 layers is observed, which further leads to destruction of the structure. Calculation of charges showed that a potassium atom at low concentrations gives up about 0,8-0,85 electrons, 0,35 of which flow on carbon atoms, and 0,4-0,5 to molybdenum disulfide. Calculation of the difference in electron densities showed that the bond between the layers of graphene, molybdenum and potassium disulfide has a covalent nature.
A triphenylamine-based conjugated polymer (PTPA-NO2)-PTH poly[4-(nitro)triphenylamine-thiophene] with multiple active polymerization sites has been prepared as the cathode material. First, the crystal phase structure, surface morphology and element states were characterized by XRD, SEM and XPS in turn, the dispersed porous arthicstructure supply a rich electrochemical interface and ion channels to improve its electrode reactivity. By calculating the energy level of HOMO and LUMO orbitals, we find that the conductivity and conjugation ability are enhanced. Then the electrochemical charge and discharge performance, CV and EIS of the battery were also tested, because of the nitro electron-absorbing functional unit are introduced in the triphenylamine skeleton, the copolymer perform a reversible specific capacity of 772.4 mAh/g with two significant charge-discharge voltage platforms under different reaction mechanisms after 500 cycling, even when the current density is 1600mA/g, this composite material still maintain a high capacity of 550mAh/g with the efficiency ≥99%.
Industrial electrochemistry, Physical and theoretical chemistry
This work demonstrates fabrication and performance (towards ofloxacin (OFL) detection) of a unique electrochemical sensor, composed of p-aminobenzene sulfonic acid (ASBA) and grapheme (GR). For this purpose, a glassy carbon electrode (GCE) was coated by GR using electrochemical deposition and then electro-polymerized by ABSA. The surface and morphology of the resulting composite pABSA/GR/GCE were analyzed using scanning electron microscopy. Oxidation peak currents obtained from the differential pulse voltammograms with the assistance of the composite pASBA/GR/GCE showed linear correlation to the OFL concentrations in the 0.1-40 μmol/L range with the detection limits of acetaminophen is 0.03 μmol/L (S/N = 3). We also demonstrated OFL detection using pASBA/GR/GCE in pharmaceutical formulations. These results indicate that pASBA/GR/GCE has very strong potential as an electro-analytical sensor for the detection of components in pharmaceutical formulations.
Industrial electrochemistry, Physical and theoretical chemistry
Definition of the variational limit for the Schrodinger torsion equation solution was considered. Energies of levels and transitions at the variational limits were calculated for different basis sets. With many modeling potentials it was shown that the quantity of reliable calculated levels linearly depends on the number of the basis functions. This number (the number of the maximum reliable state) was recommended as a measure of the basis efficiency. The slope of the straight line for the planar wave basis dependence is approximately equal to 1,03.
Graphene oxide (GO) was decorated by 3-aminopropyltriethoxysilane (APTES) through the reactions of carboxylic and epoxide groups with amino groups. Then, the chemically bonded ceramic coatings were prepared with the addition of functionalized GO. The dispersion quality of GO in the ceramic matrix was examined by scanning electron microscopy (SEM), which revealed no cracks or space between GO and ceramic matrix. The corrosion protection of the ceramic coatings was characterized by potentiodynamic polarization testing after immersion in 3.5 wt% NaCl solution for 10 h at room temperature. The corrosion resistance of the ceramic coatings was remarkably improved with the addition of the functionalized GO. The protection efficiency of the ceramic coatings increased to 90% with the addition of 0.6 wt% functionalized GO. The enhancement of the anticorrosion performance was mainly attributed to the barrier properties of the well-dispersed functionalized GO in the ceramic matrix.
Industrial electrochemistry, Physical and theoretical chemistry
Development of high-efficiency electrocatalysts for a hydrogen evolution reaction (HER) is of great importance for the sustainable production of hydrogen that is necessary to relieve the energy crisis. Construction of a non-noble metal organic-inorganic hybrid structure with excellent HER activity is the key issue in electro-catalytic fields. Here, we demonstrate a facile synthetic route to prepare a flower-like MoS2/CNFs hybrid structure with a high concentration of active edges sites using a hydrothermal method. The hybrid structure exhibits brilliant electro-catalytic performance in the HER process with an overpotential of 45 mV and the lower Tafel slope of 58 mV dec-1, as well as a remarkable durability. The excellent HER activity of the MoS2/CNFs hybrid structure is attributed to the high number of exposed active edges sites, high conductivity of carbon nanofibers (CNFs) and the high surface area of the CNFs mat.
Industrial electrochemistry, Physical and theoretical chemistry
Advanced bioelectronic devices, such as high-power biofuel cells (BFCs) and highly efficient biosensors, are limited by the difficulty of electron transfer between enzymes and electrodes. Previously reported methods for achieving electron transfer from enzymes to electrodes have relied on the use of complex biomolecule immobilization procedures, complicated matrix materials, or enzyme engineering, resulting in potential relative toxicity, high cost, as well as limited stability. Here, we report a facile method for the rapid preparation of a glucose oxidase (GOx) anode with direct electron transfer (DET) for glucose BFCs and biosensors. GOx is directly incorporated into pretreated carbon paper (CP) by adjusting the pH of the incubation medium during the immobilization process. Eexcellent bioelectrocatalytic activity is obtained when GOx is incorporated into CP near the pI of GOx. The electron transfer rate constant (ks) and the apparent Michaelis-Menten constant (KMapp) are estimated to be 12.08 ± 1.0 s-1 and 0.13 ± 0.01 mM, respectively. These findings may be extended to the development of highly conductive nanomaterials and the immobilization of other enzymes or biomolecules, providing a promising platform for the development of BFCs, biosensors, and other bioelectrochemical devices.
Industrial electrochemistry, Physical and theoretical chemistry
Chi-Yuan Lee, Sheng-Ming Chuang, Shuo-Jen Lee
et al.
Proton exchange membrane fuel cell (PEMFC) performance and the life of internal components are affected by the acidic environment. When the operating temperature of fuel cell and the relative humidity is too high, the working efficiency of the fuel cell will decrease, and shorten the life of internal component. PH sensors are brittle, bulky and expensive, so the sensor cannot be embedded inside the fuel cell. Therefore, this work applied the micro-electro-mechanical systems (MEMS) technology to develop flexible micro pH sensors. The advantages of flexible micro pH sensors include their flexibility, against acidic environment and ability to be placed anywhere in a fuel cell.
Industrial electrochemistry, Physical and theoretical chemistry