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Laser synthesis of iron nanoparticle for Fe doped hydroxyapatite coatings
摘要： Thin films of iron doped hydroxyapatite have been prepared by nanosecond Pulsed Laser Deposition (PLD). The composite target used for the deposition has been obtained by mixing commercial hydroxyapatite powder with iron-based nanoparticles produced by femtosecond laser ablation in liquid (LAL) (4% of iron nanoparticles). In fact, LAL technique allows to obtain metallic nanostructures without any toxic chemicals and reagents, with a green approach that is crucial for application in biological and medical technologies. Films have been prepared with substrate temperature growing from room temperature (RT) to 500 °C. The effect of deposition temperature on morphology, composition and structural properties of coatings has been investigated. Films deposited at higher temperature result dense and crystalline, they present microscale and nanoscale structures, an average surface roughness of 0.3 μm and magnetic properties suitable for biomedical applications.
关键词： PLD,Iron doped hydroxyapatite,Laser ablation in liquid,Regenerative orthopedic applications
更新于2025-09-23 15:23:52
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High-<formula><tex>$T_\rm{c}$</tex></formula> Superconducting Fourth-Harmonic Mixer using a Dual-Band Terahertz On-Chip Antenna of High Coupling Efficiency
摘要： This paper presents a dual-band on-chip antenna coupled high-Tc superconducting (HTS) Josephson-junction sub-terahertz (THz) fourth-harmonic mixer. The antenna utilizes a couple of different structured twin-slots to enable the resonant radiations at two frequencies, and integrates a well-designed coplanar waveguide (CPW) network for achieving good radiation coupling and signal isolation characteristics. The electromagnetic (EM) simulations show that coupling efficiencies as high as -4 dB and -3.5 dB are achieved for the 160-GHz and 640-GHz operating frequency bands, respectively. Based on this dual-band antenna, a 640-GHz HTS fourth-harmonic mixer is developed and characterized in a range of operating temperatures. The mixer exhibits a measured conversion gain of around -18 dB at 20 K and -22 dB at 40 K respectively. The achieved intermediate-frequency (IF) bandwidth is larger than 23 GHz. These are the best results reported for HTS harmonic mixers at comparable sub-THz frequency bands to date.
关键词： high-temperature superconductor Josephson junction,dual-band on-chip antenna,terahertz wireless applications,fourth-harmonic mixing,Terahertz mixer
更新于2025-09-23 15:23:52
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Sensing Properties of the <I>N</I>,<I>N</I>′-Dipentyl-3,4,9, 10-Perylenedicarboximide Small Molecule for Different Concentrations and Solvents for Sensor Applications
摘要： In present study, optical parameters based on refractive index of the PTCDI-C5 molecule were calculated using the single oscillator model. Also, significant parameters such as long wavelength refractive index, average oscillator wavelength, lattice dielectric constant, ratio of the carrier concentration to the electron effective mass, carrier concentration and electron effective mass of the PTCDI-C5 molecule were obtained. Then, sensing properties of the PTCDI-C5 molecule for different concentrations and volume percents were investigated and the effects of the concentrations and volume percents on sensing parameters were investigated. Then, the optical properties of the solutions of the PTCDI-C5 semiconductor for different solvents were investigated. Finally, these parameters obtained were discussed for sensor applications and this study was compared with the similar and related studies in the literature. PTCDI-C5 can be used in the fabrication of various sensors due to good soluble, optical, sensitivity and response behaviour.
关键词： Wemple DiDomenico Technique,Sensor Applications,PTCDIC5,One Dimensional Organic Nanostructures,Sensing Parameters,Sensitivity
更新于2025-09-23 15:23:52
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[IEEE 2018 International Conference and Exposition on Electrical And Power Engineering (EPE) - Iasi, Romania (2018.10.18-2018.10.19)] 2018 International Conference and Exposition on Electrical And Power Engineering (EPE) - Achievements and Perspectives in Contactless Power Transmission
摘要： The contactless transmission of electrical power has many important advantages in modern technology through the lack of electrical contacts and therefore of their ageing, the facile use in aggressive or explosive environments, in marine environments, medical applications, in electrical vehicles, in robotics. The efficiency is comparable to the galvanic contact transmission at small and medium distances but there is also the ability to simultaneously transmit energy and data. The paper makes a review of the main recent Romanian and foreign publications on the main techniques of contactless power transmission, regarding the optimization of the coupler 'figure of merit', and compensation topology, using both circuit analysis and FEM analysis. A recent application to contactless transmission via conductive fluids is discussed. Also, there are discussed the perspectives of the research, development and use of the described methods in the following years, in the scope of achieving interoperability, increasing the efficiency and the power transfer.
关键词： methods,wireless power transfer,perspectives,topologies,applications
更新于2025-09-23 15:22:29
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Recent Trends Concerning Upconversion Nanoparticles and Near-IR Emissive Lanthanide Materials in the Context of Forensic Applications
摘要： Upconversion nanoparticles (UCNPs) are materials that, upon absorbing multiple photons of low energy (e.g. infrared radiation), subsequently emit a single photon of higher energy, typically within the visible spectrum. The physics of these materials have been the subject of detailed investigations driven by the potential application of these materials as medical imaging devices. One largely overlooked application of UCNPs is forensic science, wherein the ability to produce visible light from infrared light sources would result in a new generation of fingerprint powders that circumvent background interference which can be encountered with visible and ultraviolet light sources. Using lower energy, infrared radiation would simultaneously improve the safety of forensic practitioners who often employ light sources in less than ideal locations. This review article covers the development of UCNPs, the use of infrared radiation to visualise fingerprints by the forensic sciences, and the potential benefits of applying UCNP materials over current approaches.
关键词： Upconversion nanoparticles,Fingerprint visualisation,Near-IR emissive lanthanide materials,Forensic applications,NIR emission
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE International Conference on RFID Technology & Application (RFID-TA) - Macau, Macao (2018.9.26-2018.9.28)] 2018 IEEE International Conference on RFID Technology & Application (RFID-TA) - A Multi-Antenna SAR-based method for UHF RFID Tag Localization via UGV
摘要： This paper presents a multi-antenna approach of the phase-based SARFID method to locate static tags by employing two UHF-RFID reader antennas installed on an Unmanned Grounded Vehicle (UGV). The UGV is remote-controlled and equipped with Laser Range Finder sensors to move inside an indoor environment, and the knowledge of its trajectory is achieved through a Simultaneous Localization And Mapping procedure. By processing the phase data collected from each reader antenna, different matching functions can be obtained and combined to improve the estimation of the bi-dimensional tag position. Differently from other localization techniques, neither reference tags (anchor tags), nor large phased array antennas are required.
关键词： Multiple RFID Antennas,UGV,UHF-RFID localization,SLAM,Robot,RFID retail applications,RFID UGV,Passive UHF-RFID system,SARFID
更新于2025-09-23 15:22:29
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Semi-Automatic Red Blood Cells Counting in Microscopic Digital Images
摘要： The main purpose of this study is to employ the modern technologies and techniques to semi-automate the quantification process of the Red Blood Cells in Microscopic thin blood smear digital images. The process needs to be more accurate, efficient and universal then the currently practiced methods. The study considers the process to be semi-automated for two reasons, i.e. due to the critical aspect life and due to the diverse nature of the Red Blood Cells in cluster formation. The Methodology of this study involved interactive simple cuts and morphological operations for splitting clusters of Red Blood Cells while counting is carried out through labeling matrix. The Red Blood Cells counting is part of the complete blood count test and is frequently suggested by the Physician to know the number of Red Blood Cells in the patient’s body. The proposed method considers for counting process of the Red Blood Cells first split the clusters and then count the Red Blood Cells. The proposed method achieved an overall True Positive Rate (TPR) of 0.997%, True Negative Rate (TNR) of 0.00265%, accuracy of 0.998% and average error rate of 0.001375% tested on 50 images, data set also on the same number of images linear correlation coefficient R2 is 0.997 between manual and semi-automatic counting of Red Blood Cells.
关键词： rouleaux splitting,healthcare applications,Clustered red blood cells,complete blood test,occlusions
更新于2025-09-23 15:22:29
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A Novel Stereo Vision Measurement System Using Both Line Scan Camera and Frame Camera
摘要： In the product surface defect detection system, the detection accuracy can be greatly improved if the surface grayscale image and depth image can be adopted simultaneously. Existing 3-D cameras have the problem in precise registration of 2-D images and 3-D data, which results in inflexibility and inevitable error in practical vision tasks. Hence, we propose a novel stereo vision measurement system which is able to simultaneously acquire registered scan grayscale images and depth images without special data registration algorithm as well as the calibration method. The proposed measurement system mainly consists of a line laser system, a line scan camera, and a frame camera. The line scan camera captures clear images of objects illuminated by the line laser. In addition, the line scan camera and the frame camera form a stereo vision sensor. In this case, the line laser stripe provides location feature of the matching point for frame camera. The epipolar constraint implements the matching process between the line scan camera and the frame camera. Finally, the stereo vision measurement model is utilized to realize the 3-D coordinate reconstruction, and the z-axis coordinate is used to generate depth image. The proposed system can simultaneously obtain the image and depth information corresponding to each pixel by means of a push sweep. In the experiment, the measurement system can achieve the accuracy of 0.13 mm within a measurement range of 500 mm × 300 mm × 200 mm.
关键词： Fault diagnosis,machine vision,visual system,measurement,laser measurement applications
更新于2025-09-23 15:22:29
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The effect of size and aspect ratio on the trapped field properties of single grain, Y–Ba–Cu–O bulk superconductors
摘要： Bulk, single grain (RE)Ba2Cu3O7?δ [(RE)BCO, where RE is a rare earth element or yttrium] high temperature superconductors exhibit significant potential for use in a variety of engineering applications due to their ability to trap large magnetic fields, which can be up to ten times greater than those generated by conventional, iron-based magnets. Limitations on the maximum size to which single grains can be grown, however, are a major obstacle to the further development of these materials. Indeed, multiple samples are often required to achieve the required superconducting properties in particular applications. The geometry of bulk (RE)BCO single grain samples plays an important role in determining the superconducting properties of a given technical arrangement. In order to gain a better understanding of the full application potential of bulk single grain superconductors, three relatively long, cylindrical YBCO single grains of different diameters were fabricated and their trapped field and total trapped flux measured at 77 K as a function of sample height. The effects of size and aspect ratio of YBCO single grains on these key applied properties have been investigated experimentally and the results compared qualitatively with the predictions of an established theoretical model. Conclusions based on the trapped field measurements on a variety of single grain samples are presented in this study and the possibilities of using assemblies of smaller samples for engineering devices, in particular, are discussed.
关键词： distribution of the trapped field,aspect ratio,assemblies,bulk superconductors,applications
更新于2025-09-23 15:22:29
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GaN Integration Technology, an Ideal Candidate for High-Temperature Applications: A Review
摘要： In many leading industrial applications such as aerospace, military, automotive, and deep-well drilling, extreme temperature environment is the fundamental hindrance to the use of microelectronic devices. Developing an advanced technology with robust electrical and material properties dedicated for high-temperature environments represents a significant progress allowing to control and monitor the harsh environment regions. It may avoid using cooling structures while improving the reliability of the whole electronic systems. As a wide bandgap semiconductor, gallium nitride is considered as an ideal candidate for such environments, as well as in high-power and high-frequency applications. We review in this paper the main reasons that offer superiority to GaN devices over better-known technologies such as silicon (Si), silicon-on-insulator, gallium arsenide (GaAs), silicon germanium (SiGe), and silicon carbide (SiC). The theory of operation and main challenges at high temperature are discussed, notably those related to materials and contacts. In addition, the main limitations of GaN, including the technological (thermal and chemical) and intrinsic (current collapse and device self-heating) features are provided. In addition, the GaN devices recently developed for high-temperature applications are examined.
关键词： wide-bandgap semiconductors,high-temperature electronics,Extreme temperature applications,gallium-nitride technology
更新于2025-09-23 15:22:29