Applied Research最新文献

Memory shape magnetic alloys, especially Heusler alloys, are important materials in replacing conventional cooling with magnetic systems. In the present study off stoichiometric Heusler alloys with nominal composition Χ₅₀Υ_25+xΖ_25-x (X = Ni; Y = Mn; Z = Sn; x = 13, 14) were prepared by arc melting followed by thermal treatment. Structural properties were analyzed with X-ray diffraction at room temperature (RT) and at elevated temperatures, above the martensite—austenite transition area, to determine the relevant crystallographic parameters and observe the transition. Martensite stabilization at RT appears to be a challenge, coexistence of martensite—austenite phases were observed and calculated for both 38–12 and 39–11 (16% and 12% austenite, respectively). Magnetization measurements versus temperature and field were recorded in the areas of interest where 1st order transitions were expected (355 K for x = 13 and 408 K for x = 14), and the magnetic entropy's changes (ΔS_m) were determined [0.4 (J/kgK) for x = 13 and 0.3 J/(kgK) for x = 14; H_max = 1 T]. The complex character of the magnetic properties and their dependence on Mn-Sn ratio and on the distance between Mn atoms is discussed. The structure and the lattice parameters were determined using an anisotropic strain broadening model; stress and strain were detected in the structure due to crystal phase coexistence.

The present study focuses on the modification induced by 200 MeV Ag¹⁵⁺ and 100 MeV O⁷⁺ ion irradiations on the structural, surface morphological, and magnetic properties of radio frequency sputtered CoFe₂O₄ (CFO) thin films grown on SiO₂/Si (100) substrates. X-ray diffraction shows amorphization of the CFO thin films when irradiated with Ag ions and varies with fluences. This effect is absent in the case of O ion irradiated CFO films. These results are consistent with the measurements from the Raman spectroscopy, where the intensities of E_g and T_2g modes are significantly reduced and further disappear in the high fluence. The surface morphology of the O ion irradiated films is dramatically different from the pristine and Ag ion irradiated films where the surfaces appear in nanopillars-like patterns. The topography of the O ion irradiated films appears to be like hill and valley structures, the roughness first increases (from 10.11 to 24.39 nm). Then it decreases to 18.93 nm on further increasing ion fluence. The coercivity, remnant magnetization, and saturation magnetization increase upon irradiation at low fluence 5 × 10¹¹ions/cm² for both the ion beams and then downturn with the increase of fluence 5 × 10¹²ions/cm². The changes in the magnetic and structural characteristics are ascribed to the defects induced by ion irradiation. These results are understood based on the structural and surface modifications induced by the electronic excitation of Ag and O ions. The study depicts that a controlled selection of ions and beam fluence can tailor the structure, morphology, and magnetic properties of ferrite films.

Insects are a major part of the planet's ecosystem and their vital role as pollinators for agriculture is undisputed. Alongside factors as climate change or loss of habitats, rising use of pesticides emerges as a key threat to insect populations. For fighting this man-made problem, development of an easy, fast, sensitive, and non-invasive biosensor for determining pesticide toxicity may help to ban harmful substances and formulations. Here, a biosensor based on Sf21 (Spodoptera frugiperda) insect cells as sensors and electric cell-substrate impedance sensing (ECIS) as physical transducer is described. Sf21 cell suspensions and well-defined pesticide solutions were mixed immediately before seeding on planar gold-film electrodes. The capacitance at 20 kHz was recorded as a function of time as a measurand for cell adhesion providing dose–response profiles of pesticide impact. For future in-field applications, decoupling of the cell culture routines from the actual cytotoxicity assay is mandatory. Thus, suspensions of Sf21 cells were cryopreserved at –80°C in the wells of multielectrode arrays and thawed anytime for conducting the assays. Five pesticides were tested for their concentration-dependent cytotoxicity expressed as EC₅₀ values by ECIS and validated using the well-established WST-1 cell viability assay. Results were found to be in good agreement. Our studies revealed cytotoxic effects of some pesticides sold for home usage far below the recommended concentration and were found to be more toxic than formulations sold for agricultural industry only.

Plasmonic gratings provide an advantageous platform for fluorescence sensing due to their compatibility with functionalization techniques, imaging detection, and the potential for signal enhancement. Among traditional fluorescence detection methods, microscopes are commonly used tools. The interaction between dye fluorescence processes and the plasmonic modes of the grating strongly depends on the measurement configuration and is influenced by the dispersion and spectral characteristics of the plasmonic modes. In our study, we investigated the angular behavior of the fluorescence emission from ATTO700 dye by varying the collection angle using a standard optical microscope coupled with a spectrometer. Our results show a clear dependence of fluorescence emission in terms of spectral shape on the collection angle that can be attributed to plasmonic mode dispersion.

Conventional synthetic sorbents for oil spill cleanup are the most widely employed materials, although a major drawback is the extensive chemical modification that they have undergone, making them economically and environmentally nonsustainable. The use of inexpensive, abundant, nontoxic, biodegradable, and reusable lignocellulosic materials might be an alternative to conventional sorbents, with obvious positive impact on sustainability and circular economy. The present study subsequently utilizes the well-established process, of converting grape molasses—a byproduct of the winemaking industry that represents a typical and abundant source of biomass—into a laser-assisted graphene-like product (LA-B). Comparative experiments were carried out with two additional materials that are similarly produced by the same laser-assisted method, yet use synthetic polyimide foil and tape polymers as precursors, namely LA-F and LA-T. The results showed that diesel oil adsorption capacity of LA-B was 33.5 g/g, while the ultraoleophilic LA-T adsorbed 57 g/g and LA-F adsorbed 41 g/g. Furthermore, the crude oil uptake was 31.1, 56.0, and 38.6 g/g for LA-B, LA-T, and LA-F, respectively. The adsorption of oil on the used materials could be well-described by pseudo-second-order kinetics, showing that over 80% of oil was removed from the water within 15 min.

Photocatalytic coatings have the potential to contribute to the purification of water via an advanced oxidation process (AOP). A commonly used method for analyzing the mechanism of the photocatalytic performance of a given reactor type is to document the degradation behavior in a solution containing methylene blue. However, since methylene blue is rather unstable, the degradation results should be viewed critically. In this work, the degradation behavior of a test solution with methylene blue on quartz glass surfaces coated with photocatalytic titanium dioxide (TiO₂) of the anatase modification was investigated through a variety of different light sources. The coating was deposited by physical vapor deposition (PVD) with the reactive pulsed DC magnetron sputtering ion plating (MSIP) method described in the study by Desch and Lake, while the quartz glasses were coated with a 100 nm thick TiO₂ coating on the outside. The same glasses were used for all experiments with TiO₂. In the determination of the degradation rate, additional experiments were performed using pure quartz glass without any coating, which made it possible to examine the influence of different light sources on the degradation rate of methylene blue in general. Three different light sources, namely UV-A, UV-C, and simple fluorescent lamps were used in this study. The concentration of methylene blue was recorded by photo spectrometer in 10-min increments throughout the experiment and the experiments were performed for 24 h in all cases. Our data indicates that the methylene blue test is a poor method because the degradation rate is not clearly differentiable due to the low stability of the test substance. Without including reference testing in the absence of a catalyst, data may be subject to misinterpretation.

This study demonstrates evidence that the mass transfer process of an enzyme (a biocatalyst) is the rate-limiting step in the starch hydrolysis reaction during food digestion. The significance of this work has been to compare the reaction rate of starch hydrolysis by salivary enzymes with the mass transfer rate of rate-limiting enzymes. This research has applied mass transfer and reaction engineering theory in a quantitative study of starch hydrolysis, and a dimensionless group, the Damköhler number (Da), has been calculated based on glucose measurements from a beaker and stirrer system. The values of the Da number in this study (0.3–19) indicate that both the time constant for mass transfer and the time constant for reaction are significant parameters. Scanning electron microscopy images emphasize that compression (simulated mastication) helps to break the plant cell wall of starch. Mass-transfer resistance needs to be considered during food digestion studies. The Da numbers are significantly affected by both compression forces (internal mass-transfer coefficients) and stirrer speeds (external mass-transfer coefficients) in this beaker and stirrer system.

Aerosol jet printing is a promising technology for printing functional materials on a variety of substrates with high precision and resolution. This technology has the potential to revolutionize the manufacturing industry by providing a low-cost, high-resolution printing technique that can be used to produce additively printed electronics, sensors, and energy devices. However, the optimization of this process has traditionally relied on time-consuming trial-and-error methods, hampering its efficiency and scalability. Machine learning (ML) models have the potential to overcome these challenges and improve the quality, speed, and efficiency of the printing process. In this paper, we propose an approach that leverages ML algorithms to streamline and enhance the aerosol jet printing optimization process. Our methodology involves data collection through systematic experimentation with various parameter settings. This data set serves as the foundation for training different ML model capable of predicting printed line characteristics and optimal printing process parameter. We validate our approach by performing experiments on different inks, and we compare the results of our ML-based optimization approach to those obtained using traditional trial-and-error methods. The results demonstrate that our approach offers significantly higher accuracy and efficiency. To enhance our approach's accessibility and ease of use, we incorporate AutoML techniques which automates the process of selecting the most suitable ML algorithms and hyperparameters, reducing the burden of manual configuration. Furthermore, we introduce a user-friendly web-based interface that facilitates the entire ML pipeline, from data preprocessing to prediction and batch processing. This interface empowers users to efficiently manage and manipulate their data, select appropriate ML algorithms, and execute predictions, ultimately improving accuracy and model performance.

This study demonstrates integration of a zeolite material in a ceramic microcomponent intended for use in sampling and analysis of environmental carbon dioxide (CO₂). The zeolite material was integrated in bulk form, allowing for adsorption of large quantities of CO₂ compared to previous integration attempts as thin films. To obtain a porous bulk material, an injectable slurry was developed, where expandable polymeric microspheres were added as a sacrificial template. By varying water and sphere contents of the slurry, it was possible to tune the porosity of the zeolite material between 55% and 72%. This in turn affected the flow resistance of the microcomponents, where an increase in the porosity of the filling from 62% to 72% reduced the flow resistance from 84 to 28 kPa min cm⁻³. In addition, the spheres facilitated complete fillings free from cracks. The zeolite material was seen to retain its ability to adsorb CO₂ after processing, but it was not possible to quantify the level of retention compared to unprocessed zeolite.

This paper presents a simple method to transform two-dimensional data sets into a format that can be easily processed into sound files. These files can be loaded into software wavetable synthesizers to create audible forms of data that can represent complex information. Some background about sonification will be discussed, and the simple method developed here will be applied to graphene optoelectronics. Some key illustrative examples will be used to demonstrate the method, including data sets from previous work on light emission from graphene field effect transistors. We use the sonification method to show how changes in observed phenomena (e.g., light emission intensity and spectral shape) result in changes of the resulting sound (such as the timbre). Demonstrations are included in video format to hear and illustrate the method and resulting effects.