Application Fields Research Articles

Production of Nitrogen Dioxide, NO2-, Anion from Dissociative Electron Attachment to Nitromethane below 1 eV and Its Temperature Dependence: Direct vs Dipole Bound Mediated Processes.

Reaction induced by slow electrons is implicated in a large field of research and applications. Below 3-4 eV, dissociative electron attachment efficiently fragments molecules via (1) shape resonance or (2) mediated by the formation of a dipole bound anion. While the temperature dependence of process 1 is well-known, that of 2 is not clearly established. Nitromethane is the prototypical molecule for which the electron attachment leads to the formation of both a dipole bound and a covalent anion. We provide here a comprehensive study of the fragmentation of nitromethane by <1 eV electron and the unusual temperature effects attributed principally to process 2.

Inkjet assisted manufacturing of untethered magnetic devices: A comparison between three routes to pattern artificial water striders

AbstractUntethered devices controlled by an external magnetic field are becoming more and more widely used in a wealth of applicative fields: medicine, precise micromanipulation, and environment management. Their production strongly relies on the use of complex and time-consuming technologies typically borrowed from the microelectronic field. In an attempt to reduce costs and enhance manufacturing flexibility, additive manufacturing has been investigated as a relevant alternative for untethered microrobots production. Between the large number of additive manufacturing technologies, inkjet printing is relatively poorly investigated for the production of this kind of devices, and the present work aims at exploring its potential. The work establishes a comparison between different approaches for the inkjet manufacturing of magnetically guidable microdevices. In particular, it focuses on the manufacturing of fully inkjet-printed magnetic devices by proposing two methods of production. The first consists in the electroless metallization of non-magnetic devices printed with SU-8 resin, while the second is based on the inkjet printing of a dispersion of magnetic nanoparticles in SU-8 resin. As a result, inkjet-printed devices controllable by an external magnetic field can be obtained. Multi-step and one-step production methods are compared in terms of quality of the obtained elements, easiness of production, and mechanical properties. The morphology of the finished devices, their surface quality, and their magnetic actuability are analyzed and discussed.

ACP-Net: Asymmetric Center Positioning Network for Real-Time Text Detection

Scene text detection is crucial across numerous application fields. However, despite the emphasis on real-time performance in scene text detection, most existing detection models utilize the Feature Pyramid Network (FPN) for feature extraction, often disregarding its inherent limitations. Integrating high-resolution multi-channel features into FPN requires substantial computational resources. While FPN treats local and global features equally and is stable in various applications, its suitability for text-specific features is questionable. To this end, we propose the Asymmetric Center Positioning Network (ACP-Net) to replace FPN, achieving accuracy and real-time text detection in complex scenarios. ACP-Net features an asymmetric feature structure with independent branches for global and local information, along with an adaptive weighted fusion module to capture long-range dependencies effectively. In addition, a text center positioning module enhances text feature understanding by learning feature centers. Comprehensive evaluations across various terminals confirmed ACP-Net’s superior accuracy and speed.

Research on Intelligent Digital Manufacturing Platform Based on Artificial Intelligence Deep Neural Network

In today’s information age, intelligent manufacturing has become a significant trend of future industrial development. The neural network plays a vital role as the basis of smart manufacturing. This is a kind of intelligent algorithm that can simulate human brain organization, with strong learning ability and computing power, and has achieved remarkable results in the application field; the most typical representative is deep neural network, especially in recent years, an artificial intelligence developed based on deep neural network has entered the application stage, providing a new idea and model for industrial production. Based on this, taking the clothing production process as an example, this paper combined transfer learning and network fine-tuning technology to build a Faster RCNN model based on the ResNet-101 network to realize the positioning and recognition of clothing style map features and create an intelligent generation platform for clothing process flow on this basis.

Effect of Hexamethylenetetramine concentration on the structural, morphological, optical and bactericidal action of Eu-doped TiO2 quantum dots derived through wet chemical method

Recently, it has been established that bacteria are quickly developing resistance to traditional antibiotics; as a result, one of the most significant challenges facing the healthcare sector is treating illnesses linked to bacterial infections. In this work, we used a simple wet chemical approach to easily prepare pure TiO2 and Eu-doped TiO2 quantum dots (QDs) with different hexamethylenetetramine (HMT) concentrations: 0.1, 0.15, and 0.2 M. As indicated by XRD results, the pure TiO2 possesses the tetragonal anatase phase, while the Eu-doped TiO2 samples prepared with the support of HMT content during sample synthesis promotes the amorphous phase. The Eu-doped TiO2 sample prepared at 0.1 M HMT has an almost uniform distribution of ultra-fine QDs, with an average particle size distribution of 2.05 ± 0.17 nm, according to the TEM image. The Eu 3d core level doublet at 1134.29 and 1164.21 eV, which correspond to Eu3+3d5/2 and Eu3+3d3/2, respectively, is displayed in the XPS data for the sample prepared at 0.1 M HMT. Based on the findings of the Tauc plot, the sample prepared at 0.2 M HMT is found to have a larger optical band gap than the pure TiO2 and Eu-doped TiO2 samples prepared at different HMTA concentrations. According to antibacterial tests, the zone of inhibition for E. coli increases from 7 ± 0.55 to 12 ± 0.60 when the concentration of the Eu-doped TiO2 sample prepared at 0.15 M HMT is increased from 100 to 300 µg/mL. In the field of biomedical application, this enhanced antibacterial activity of Eu-doped TiO2 QDs can be utilized to create a potent medication for bacterial resistance.

Maillard Type Reaction for Electroless Copper Plating onto Ceramic Nanoparticles

A high demand for oxide dispersion strengthened (ODS) materials arose in wide fields of application. The electroless plating method has been presented as an elegant way to overcome different surface energies and obtain metal‐plated ceramics. However, copper electroless plating is still performed under harsh conditions with toxic and expensive reagents, including noble metals and harsh reducing agents like formaldehyde and hydrazine. To create a pure copper metal matrix in an environmentally friendly and efficient way a previously reported method is advanced in a way that naturally occurring amino acids are utilized. A screening of several amino acids leads to an improvement in phase purity and atomic efficiency. Therefore, a Maillard type reaction with lysine as amino compound is reported to show the best results in the particle coating for all ceramic nanoparticles evaluated. The metal plating results in uniform round micro particles showing a homogeneous coating. In order to obtain copper matrix composites, the prepared particles are successfully implemented in a PBF‐LB/M process after mixing with a highly conductive copper alloy. The resulting products were investigated by transmission electron microscopy, scanning electron microscopy, powder X‐ray diffraction, and optical density measurements.

The JANNuS-Saclay platform: New developments for the understanding of evolutions under irradiation in materials

The JANNuS-Saclay multi-irradiation platform includes a triple beam facility coupled to an in-situ Raman spectrometer, established at CEA Saclay in 2009. In addition to the triple-beam chamber, two single-beam chambers are set up. Sample temperature can be varied from −180 °C to 800 °C, and at −260 °C or at 1200 °C in dedicated devices. The platform is also equipped with a multi-ion Beam Analysis chamber. JANNuS Saclay facility is a powerful tool to understand the changes generated by irradiation in materials, especially in nuclear application fields. This paper presents the recent facility developments since 2020.

Room-temperature phosphorescence and aggregation behavior in chiral heavy-atom-free organic molecules

Purely organic room temperature phosphorescence materials (RTP) have attracted much attention recently, but most of them are substituted with heavy atoms to enhance the intersystem crossing (ISC), which requires complicated design and synthesis. Herein, we report four chiral heavy-atom-free small molecules which integrate properties of aggregation and long-lifetime room temperature phosphorescence. The phosphorescence lifetime of synthesized chiral molecules is measured to be 150 ms, and the phosphorescence quantum yield reaches 15 % at room temperature. The twisted chiral conformation of four molecules not only affect aggregation photoluminescence properties but also can synergistically stabilize triplet exciton in the triplet excited states for excellent ISC efficiency. This strategy enriches the application fields of chiral aggregated long-lifetime room temperature phosphorescent materials.

Preliminary investigation of nanofibrous membranes for sound absorption

Nanofibrous membranes show interesting mechanical properties, low thickness and lightness, besides the possibility of using a great variety of polymers. The electrospinning technique makes possible the production of polymeric random nanofibres to form nonwoven membranes, which are currently used in several application fields, such as filtration, biomedicine, biomechanics, electronics, and composite materials. Their application in the automotive and aerospace engineering field could bring significant benefits to the acoustic comfort design. However, their acoustics properties still need to be further assessed. This study investigates the acoustic absorption of electrospinning-made nanofibrous membranes in Nylon 66 with different fibre diameters and mat thicknesses. Morphological and thermal characterisation of the electrospun membranes have been assessed via Scanning Electron Microscope (SEM) and Differential Scanning Calorimetry (DSC), respectively. The acoustic absorption characteristics of various samples changing fibre diameter, membrane thickness and mounting conditions were tested in the impedance tube. The results showed more relevant acoustic absorption properties in the nanofibrous membrane coupled with a polyester fibre. Further studies will clarify if filament direction and constituent material can be improved for a more durable and resistant membrane application.

Synthesis, Structure, and Actual Applications of Double Metal Cyanide Catalysts.

Double metal cyanide (DMC) complexes represent a unique family of materials with an open framework structure. The main current application of these complexes in chemical industry is their use as catalysts (DMCCs) of the ring-opening polymerization of propylene oxide (PO), yielding branched polyols, highly demanded in production of polyurethanes and surfactants. The actual problem of chemical fixing carbon dioxide from the atmosphere gave new impetus to the development of DMCCs, which turned out to be effective in oxirane/CO2 copolymerization. In recent years, new types and formulations of DMCCs were created, so that greater understanding of the reaction mechanisms was achieved and new fields of catalytic applications were found. In the present review, we summarized background and actual information about the synthesis, structure, and mechanisms of the action of DMCCs, as well as their application in the development of new materials and fine chemicals.

Structural and optical properties of Ce-stabilized tetragonal phase and intense blue emission of monoclinic phase in ZrO2 nanoparticles

Structural and optical properties of Ce-stabilized tetragonal zirconium dioxide (ZrO2) and intense blue emission of monoclinic ZrO2 are presented in this paper. Nanoparticles of ZrO2 in the stabilized tetragonal and monoclinic phases have been prepared by the solution combustion method. X-ray diffraction studies and Rietveld refinement of the diffraction pattern show the stabilization of ZrO2 in the tetragonal phase (t-ZrO2) with Ce doping. It is the host-dopant ionic size mismatch that leads to lattice distortion and hence the t-ZrO2 stabilized phase. Raman modes confirm the phase transformation from the monoclinic to a tetragonal phase of ZrO2. The presence of oxygen vacancies and surface states in the samples play a role in altering the optical band gap. The dopant Ce-ions create defects/oxygen vacancies, which act as the trapping sites for electrons and holes/the donor and vacancy-related impurity levels. It is transition between these levels or between delocalized conduction bands that lead to band gap reduction. Photoluminescence studies reveal the presence of structural phase transformation dependent emission bands. The monoclinic phase (m-ZrO2) exhibits an intense blue emission originating from the asymmetric and unusual oxygen coordination of Zr in the m-ZrO2. The chromaticity coordinates indicate that the prepared material and adopted strategies are suitable in the field of optoelectronic application.

Sandwich structures in bio-composite material for sustainable acoustic solutions

The use of bio-based materials in acoustic applications has gained a lot of attention recently as a functional and environmentally friendly alternative for synthetic materials. This is because conventional synthetic fibers have a significant impact on the environment and the health risks of people. The focus is now on developing composite systems that minimize environmental harm by using energy and materials more efficiently, and by substituting synthetic or petroleum-based materials with more sustainable options, such as natural fibers. These natural fibers are favoured for their biodegradability, sustainability, and widespread availability, earning them the label of "green materials." Thus, this paper aims to investigate the soundproofing capabilities of a novel sandwich structure composed of hemp fibers and bio-epoxy resin, aiming to broaden the application field of natural fiber composite materials.

A phenomenon-based approach to handling multiple paradigms: Investigating power in international knowledge transfer through active categorization

In this article, we propose a phenomenon-based approach as a suitable way of handling multiple paradigms in practice. We implement the phenomenon-based approach by means of active categorization to be differentiated into three steps – differentiation, integration, and patterning – and apply this approach to international knowledge transfer (IKT) in multinational enterprises (MNE). Via differentiation, we classify the IKT literature into six theoretical perspectives. Via integration, we identify power as the common element underlying knowledge transfer in MNEs. This leads us to conceptualize power as an influence on IKT through the paradigms and power assumptions of the Burrell-Morgan matrix and the characteristics of power proposed by Clegg. Via patterning, we draw implications for phenomenon-based multi-paradigm research, such as the dominance of regulative and functionalist power-assumptions over interpretive and critical ones and structural power lenses over rules of practice. We deduce recommendations and propose research questions for multi-paradigm research. With our conceptual frame, we enable researchers and practitioners to conceptualize power in more sophisticated ways. We contribute to multi-paradigm studies in Cross Cultural Management by exemplifying the benefits and implications of a phenomenon-based approach as a way to handle multiple paradigms in practice and propose further fields of application.

Deflection and Performance Analysis of Shape Memory Alloy-Driven Fiber–Elastomer Composites with Anisotropic Structure

Due to their advantageous characteristics, shape memory alloys (SMAs) are prominent representatives in smart materials. They can be used in application fields such as soft robotics, biomimetics, and medicine. Within this work, a fiber–elastomer composite with integrated SMA wire is developed and investigated. Bending and torsion occur when the SMA is activated because of the anisotropic structure of the textile. The metrological challenge in characterizing actuators that perform both bending and torsion lies in the large active deformation of the composite and the associated difficulties in fully imaging and analyzing this with optical measurement methods. In this work, a multi-sensor camera system with up to four pairs of cameras connected in parallel is used. The structure to be characterized is recorded from all sides to evaluate the movement in three-dimensional space. The energy input and the time required for an even deflection of the actuator are investigated experimentally. Here, the activation parameters for the practical energy input required for long life with good deflection, i.e., good efficiency, were analyzed. Different parameters and times are considered to minimize the energy input and, thus, to prevent possible overheating and damage to the wire. Thermography is used to evaluate the heating of the SMA wire at different actuation times over a defined time.

Epitaxial growth of bottom-crosslinked ZnGa2O4 nanowire arrays on c-plane GaN/Al2O3 substrate

The epitaxial growth of highly ordered ZnGa2O4 nanowire arrays and the construction of connectivity states between the individually segregated nanowires would significantly improve the performance of ZnGa2O4-based devices and expand their application fields. Herein, a strategy to construct high crystalline quality and well-aligned bottom-crosslinked ZnGa2O4 nanowire arrays along seven equivalent crystallographic directions of [111], [111̅], [11̅1], [1̅11], [11̅1̅], [1̅11̅] and [1̅1̅1] on Au-coated (0001) GaN/Al2O3 substrates using chemical vapor deposition (CVD) is proposed. The vapor-liquid-solid (VLS) mechanism dominates the entire growth process. The horizontal nanowires induced to nucleate and grow by catalyst droplets encountered and then turned towards inclined nanowires. Meanwhile, catalyst droplets that failed to move horizontally were enclosed by horizontal nanowires, resulting in the induction of perpendicular nanowire growth. The film-like horizontal nanowires connected all the inclined and perpendicular nanowires to form the bottom-crosslinked nanowire arrays. Additionally, the morphology, structure and optical properties of the ZnGa2O4 nanowire arrays, as well as the influence of Au layer thickness and growth time on the growth of ZnGa2O4 nanowires, were further characterized and thoroughly investigated. The proposed strategy achieved the growth of epitaxial well-aligned ZnGa2O4 nanowire arrays with bottom cross-linking, which is conducive to the application of ZnGa2O4 nanowires in optoelectronics.

A high-efficiency and selective fluorescent assay for the detection of tetracyclines

Tetracyclines (TCs) rank second globally in the use of animal infection therapy and animal husbandry as growth promoters among all antibiotics. However, large amounts of TCs residue in food products and more than 75% of TCs are excreted into the environment, causing adverse effects on the ecological system and human health. It has been challenging to simultaneously realize low-cost, rapid, and highly selective detection of TCs. Here, inspired by the fluorogenic reactions between resorcinol and catecholamines, we find the fluorescence quenching ability of tetracycline (TC) and firstly propose a fluorescent “turn-off” detection of TC using dopamine and 4-fluororesorcinol. The optimal reaction condition for the fluorescent assay is investigated and the optimized probe showed a good limit of detection (LOD of 1.7 µM) and a wide linear range (10 µM to 350 µM). Moreover, this fluorescent assay proved to be an effective tool for detecting TC in river, Sprite, and beer samples, which represent the aquatic environments and food and may contain tetracyclines residues. Finally, the high selectivity of the method for TC has been confirmed by eliminating the interference from common substances. The proposed strategy provides a high-efficiency and selective solution for the detection of TCs in environment and food and the application fields of this fluorescent assay could be further expanded in the future.

Simulation-based effective comparative analysis of neuron circuits for neuromorphic computation systems

The spiking neural networks (SNN) which are inspired by the human brain offers wider scope for application in the growth of neuromorphic computing systems due to their brain level computational capabilities, reduced power consumption, minimal data movement cost, and among other advantages. Spike-based neurons and synapses are the essential building blocks of SNN, and their efficient implementation is vital to its performance enhancement. In this regard, the design and implementation of spiking neurons have been the major focus among the researchers. In this paper, functioning of different leaky integrate fire (LIF)-based spiking neuron circuits like frequency adaptable CMOS-based LIF, resistor-capacitor-based (RC) LIF, and volatile memristor-based LIF are subjected to comparison. The work mainly focuses on revealing analysis of spike duration and amplitude, number of spikes produced during excitation period, threshold operation, field of application, and various other significant parameters of aforementioned neuron circuits. Extensive simulations of these circuits are carried out utilizing the Cadence Virtuoso simulation environment in order to validate their behavior. Further, a brief comparative analysis is executed considering into account the attributes like circuit complexity, supply voltage, firing rate, membrane capacitance, nature of input/output, refractory mechanism, and energy consumption per spike. This work seeks to assist researchers in selecting an appropriate LIF model to efficiently construct memristors and/or non-memristors based SNN for certain application.

The elemental variance between the "rice" and "non-rice" portions of Maifanitum and its health risk assessment

BackgroundMaifanitum, a mineral used in Chinese medicine, was first documented during the Song Dynasty (960-1279). Historical records suggest its multifaceted therapeutic properties, including detoxification and stasis resolution, necrosis removal and tissue regeneration, diuretic and calculi dissolution and prolonging life. The concentration of elements in Maifanitum may vary depending on its origin, different parts, which can affect its effectiveness in different fields of applications. Therefore, the analysis of elements in Maifanitum and the subsequent health risk assessment have been conducted. This provides an important basis for the quality control and application safety of Maifanitum. MethodThe analytical techniques employed in this study are inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometry (ICP-OES), utilized for the quantitative assessment of 60 elements (Refer to Appendix 1) within Maifanitum samples. Based on the test results, chemometric methods are employed to evaluate the characteristics and differences in elemental concentration from different sources and locations. Additionally, a preliminary health risk assessment is conducted for Maifanitum from different origins and various parts. ResultsWe have established a fingerprint of the elements within Maifanitum, demonstrating a commendable level of similarity. The findings from hierarchical cluster analysis（HCA） corroborated with those from principal component analysis (PCA), collectively unveiling a systematic profile of elemental disparities between Maifanitum samples of diverse origins and applications. It also revealed that there are differences in the concentration of Al, Ga, Be, Hf, Na, Sn, Ti, Zr, Gd, Tb, Sr, Pb, Ce, Ba and other elements in different parts of Maifanitum. While Cd, As, and Cu levels in all samples were within the permissible limits as defined by the Chinese Pharmacopeia, Pb concentrations in the majority of samples were found to surpass these standards, albeit slightly in the ''non-rice'' fraction. The assessment of both beneficial and deleterious elements indicates that the ''non-rice'' fraction of Maifanitum possesses superior quality attributes. Moreover, the overall concentration of rare earth elements in Maifanitum is substantially below the established lower threshold for daily human consumption, with no immediate evidence suggesting any adverse health risks. ConclusionThis study provides a basis for the quality control and safety evaluation of Maifanitum in clinical use.

Stochastic stability of random stacking of blocks

The paper explores the stability of a tower obtained by stacking identical rectangular blocks on top of each other with an inherent randomness due to slight positional offsets between successive blocks. With probabilistic modeling techniques, the diffusive behavior of the stacking process is studied and the collapse is seen as a first passage time problem. In the considered model, alignment errors are idealized as independent Gaussian random variables with zero mean and given standard deviation. We derive expressions for the joint probability density functions of block positions, and analyze their correlation. The study extends to the stochastic stability of a stack of given height, by exploring the statistical characteristics of the center of gravity of the part of tower above each block. Eventually, the probabilistic analysis of collapse is developed to quantify the statistics of the number of blocks that can be heaped up before the tower topples. Although this problem may initially appear playful, it offers an illustrated introduction to first passage problems on a non homogenous process. From a practical standpoint, this analysis offers a simple understanding of the influence of alignment errors on the overall stability of a stack, which may find several fields of application.

Structuring of electrorheological fluids in polymer matrices for miniature actuators

Miniature actuators are utilized in various application fields, from robotics to medical devices, where compact dimensions, precise movements, and cost-effectiveness are crucial factors. Particularly for applications like braille displays, there is a critical demand for lightweight, portable, and affordable actuators to integrate into daily life for visually impaired people. However, existing actuation technologies such as electroactive polymers, electrorheological materials, and piezoelectric elements often do not meet the specific requirements of miniature actuators, especially for braille displays. Therefore, this study investigates the behavior of electrorheological fluids incorporated into polymer matrices of cellulose and proteins for miniature actuators to overcome the primary challenge of sedimentation through the structuring of the liquid. The gel formulations are tested in three distinct setups: the V-shaped, horizontal plates, and valve system. These experiments demonstrated immediate structural changes in the gel formulations, achieving reversible movement. Furthermore, the valve setup even enabled the analysis of the strength of the hardened mixtures by the resistance against applied air pressure. The results demonstrate that incorporating electrorheological fluids into polymer matrices is not only feasible but also preserves the characteristic behavior of electrorheological fluids under electrical field exposure. This behavior validates the applicability and suitability of modified electrorheological fluid mixtures in miniature actuators.