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Highly enhanced photoelectrochemical cathodic protection performance of the preparation of magnesium oxides modified TiO2 nanotube arrays
摘要： The magnesium oxide modified TiO2 nanotube arrays (TiO2 NTs) was prepared to investigate the photoelectrochemical (PEC) cathodic protection performance to 304 stainless steel (SS 304). With the annealing treatment at different temperature, the surface of the modified materials changed remarkably. The film-like Mg(OH)2 obtained at 400 °C transformed to MgO particles after treatment at 500 °C and 600 °C. Further thermal processing at 700 °C enables MgTixOy@TiO2 shell-core structure. Using photoelectrochemical approaches to study the series samples, the cathodic protection performance of the modified TiO2 NTs has significantly improved. The magnesium oxides modified TiO2 NTs treated at 600 °C (Ti-Mg-O 600) shows the best PEC cathodic protection to the underneath steel. Further investigation shows that the highly enhanced PEC cathodic protection performance of Ti-Mg-O 600 was attributed to the effective separation of photogenerated carriers, the increase of carrier concentration and the negative shift of the conduction band potential.
关键词： Magnesium oxides,Modified TiO2,TiO2 nanotube arrays,Photoelectrochemical cathodic protection
更新于2025-09-23 15:22:29
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Highly-transparent, UV-B protective Al-Zn-O films with potential application in greenhouse screen systems
摘要： Extremely thin, Al-Zn-O composite films (21±6 nm) are deposited on fused silica substrates under various percentages of oxygen in the oxygen/argon gas mixture (3, 4.5, 6, and 7.5 %). The films are prepared by a cylindrical DC magnetron sputtering system, utilizing a single compound target. The effects of the oxygen percentage on the compositional, morphological, and optical properties of the films are investigated by energy-dispersive X-ray spectroscopy, scanning electron microscopy, UV-Visible spectrophotometry, and atomic force microscopy. The chemical composition of the films is Al1 Z1+X O with 0.2<X<1. The average visible transmittance of 93.6% with a high level of uniformity is obtained when the sputtering deposition performs under the oxygen percentage of 6%. It is found that the optical band gap of the films can be tailored towards higher energy by increasing oxygen percentage; however, the adjustable range is not so significant. The results offer cost-efficient films with high, uniform transmittance in the visible region and with an ability to attenuate more than 10% of incident UV-B radiation (280-315 nm). This type of films can potentially be included in greenhouse screen systems to effectively protect the plants from the elevated UV-B radiation without altering natural conditions.
关键词： Al-Zn-O film,cylindrical DC magnetron sputtering,band gap tailoring,effective UV-B protection of plants
更新于2025-09-23 15:22:29
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Evaluating impact damage to fabric-based personal armor by infrared NDT
摘要： The paper considers the thermo-mechanical mechanism of interaction between the damage agents and armor protection made of polymer fabrics. A simplified mathematical model is proposed to describe the deceleration of a damage agent within an armor fabric due to the dissipation of energy expended on irreversible stretching deformations of fabric fibers, as well as fiber slipping friction and material heating. Woven fabric layers are replaced by solid layers characterized by averaged stiffness and viscosity. A discrete numerical model of a solid material is proposed to reduce a problem with a finite number of degrees of freedom; motion equations are obtained on the basis of the Lagrange equations of the second kind, and for their integration, a stable non-conservative difference scheme is used. The software implementation is based on a functional-object paradigm which allows the modeling of conjugated processes. The parameters of governing equations are identified by using the experimental data. Some illustrative examples of interaction between damage agents and armor barriers with different arrangement of fibers are presented. The proposed model can be used to predict the quality of armor protection with the changing number and location of fibers, as well as to test the armor protection by applying the technique of infrared thermography.
关键词： Armor protection,mathematical model,irreversible deformation,infrared thermography,energy absorption,numerical scheme,composite material,fiber friction
更新于2025-09-23 15:22:29
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Avalia??o do conhecimento de médicos n?o radiologistas sobre aspectos relacionados à radia??o ionizante em exames de imagem
摘要： Objective: To assess the non-radiologist physicians’ knowledge on the use of ionizing radiation in imaging. Materials and Methods: Cross-sectional study utilizing an anonymous questionnaire responded by physicians in clinical and surgical specialties, divided into two parts as follows: one including questions about the physicians’ characteristics, frequency of imaging studies requests and participation in professional updating events, and another part including multiple choice questions approaching general knowledge about radiation, optimization principles and radioprotection. Results: From a total of 309 questionnaires, 120 (38.8%) were responded, 50% by physicians in surgical specialties and 50% in clinical specialties; respectively 45% and 2.5% of physicians responded that magnetic resonance imaging and ultrasonography use ionizing radiation. Overall, the average grade was higher for surgical specialists with no significant difference, except for the question about exposure in pregnant women (p = 0.047). Physicians who are professionally updated, particularly those attending clinical meetings (p = 0.050) and participating in teaching activities (p = 0.047), showed statistically superior knowledge about ionizing radiation as compared with others. Conclusion: The non-radiologist physicians’ knowledge is heterogeneous and in some points needs to be improved. Multidisciplinary clinical meetings and teaching activities are important ways to disseminate information on the subject.
关键词： Questionnaire.,Knowledge,Ionizing radiation,Imaging diagnosis,Physicians,Radiation protection
更新于2025-09-23 15:22:29
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Study on 4H-SiC GGNMOS based ESD Protection Circuit with Low Trigger Voltage Using Gate-Body Floating Technique for 70 V Applications
摘要： In this letter, we propose a 4H-SiC based electrostatic discharge (ESD) protection circuit with a new structure that has low on-resistance and good high-temperature characteristics while improving the high triggering voltage by applying an improved floating technology to the 4H-SiC grounded-gate n-type metal–oxide–semiconductor (GGNMOS) for 70V applications. Electrical characteristics of the 4H-SiC-based conventional GGNMOS, floating-body NMOS (FBNMOS), and the proposed ESD protection circuit were compared and analyzed using the transmission-line pulse test. To verify the high-temperature characteristics of the proposed 4H-SiC-based ESD protection circuit, its thermal reliability was measured at high temperatures (300–500 K).
关键词： FBNMOS,electrostatic discharge protection,trigger voltage,GFNMOS,GGNMOS,4H-SiC
更新于2025-09-23 15:22:29
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A highly efficient reduced graphene oxide/SnO2/TiO2 composite as photoanode for photocathodic protection of 304 stainless steel
摘要： A new photoanode RGO/SnO2/TiO2 nanocomposite material with a heterojunction structure was fabricated via hydrothermal method. The RGO/SnO2/TiO2 composite with different graphene content were prepared to explore optimal photoelectrochemical properties compared with pure TiO2. The morphology, structure and optical property of the obtained composite were characterized by TEM, FTIR, XRD and UV–vis. The photocathodic protection effect and anticorrosion properties of the nanocomposite for 304 stainless steel (304SS) were investigated by photocurrent density, open circuit potential, Tafel polarization curves and electrochemical impedance spectroscopy. The results show that compared with pure TiO2, the composite can provide an effective protection for 304SS not only under white light irradiation but also in the dark, and the optimal sample electrode potentials negatively shifted to ?590 mV under illumination. The possible photocathodic protection mechanism of the composite was also proposed.
关键词： Photocathodic protection,Corrosion resistance,Electrochemical properties,Graphene,Heterojunction
更新于2025-09-23 15:22:29
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A Novel Transmitting Module Self-Monitoring Protection System Based On MEMS Sensors and Actuators
摘要： Design, fabrication, and measurements of a novel transmitting module self-monitoring protection system are presented in this letter. Such a system is based on micro-electromechanical systems (MEMS) sensors and actuators for monitoring and protecting the microwave amplifier circuit. The transmitting module self-monitoring protection system consists of the RF MEMS switches, the directional coupler, and the MEMS power sensors. When the microwave amplifier circuit is at an abnormal state ("open," "short," or "overload"), the transmitting module self-monitoring protection system can isolate the microwave amplifier circuit out of order and reconfigure the transmitting module into impedance matching within 36 ms. When the microwave amplifier circuit is at the overload state, the error between the set switching power and the actual switching power is less than 9%. The measured results agree well with the theory.
关键词： Microelectromechanical systems (MEMS) power sensor,microwave amplifier circuit,RF MEMS switch,self-monitoring protection
更新于2025-09-23 15:22:29
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CoPi/Co(OH)2 Modified Ta3N5 as New Photocatalyst for Photoelectrochemical Cathodic Protection of 304 Stainless Steel
摘要： In this work, CoPi and Co(OH)2 nanoparticles were deposited on the surface of Ta3N5 nanorod-arrays to yield a novel broad-spectrum response photocatalytic material for 304 stainless steel photocatalytic cathodic protection. The Ta3N5 nanorod-arrays were prepared by vapor-phase hydrothermal (VPH) and nitriding processes and characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV-Vis spectroscopy, respectively, to obtain morphologies, crystal structures, surface compositions, and light response range. In order to analyze the performance improvement mechanism of CoPi/Co(OH)2 on Ta3N5 nanorod-arrays, the electrochemical behavior of modi?ed and unmodi?ed Ta3N5 was obtained by measuring the open circuit potential and photocurrent in 3.5 wt% NaCl solution. The results revealed that the modi?ed Ta3N5 material better protects 304 stainless steel at protection potentials reaching ?0.45 V.
关键词： CoPi/Co(OH)2 modi?cation,cathodic protection,Ta3N5 nanorod-arrays,photocatalysis
更新于2025-09-23 15:22:29
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[IEEE ESSCIRC 2019 - IEEE 45th European Solid State Circuits Conference (ESSCIRC) - Cracow, Poland (2019.9.23-2019.9.26)] ESSCIRC 2019 - IEEE 45th European Solid State Circuits Conference (ESSCIRC) - A 26-Gb/s 3-D-Integrated Silicon Photonic Receiver in BiCMOS-55 nm and PIC25G With a?? 15.2-dBm OMA Sensitivity
摘要： This paper deals with those measures against overvoltage taken when protecting buildings occupied by people or animals. Such overvoltages can appear in the case of ground fault if the grounding system of the building is located within a potential funnel of a transmission tower's grounding system. This paper presents an entire concept regarding protection against any potential rise within the building. Computations of electrical potential on the grounding system having been performed using data obtained by measurements. This includes equipotential bonding, overvoltage protection of the building, and a transformer substation with metal–oxide varistors and gas-discharge arresters installed on the low-voltage line. A simulation model for the entire overvoltage protection based on known mathematical models has been merged within this paper. Adequate overvoltage protection elements were selected for protection against potential rises in the grounding systems of buildings on the basis of computation results.
关键词： Gas-discharge arrester (GDA),grounding electrodes,overvoltage protection,grounding system,metal-oxide varistor
更新于2025-09-23 15:21:01
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A Local measurement based protection technique for distribution system with photovoltaic plants
摘要： Inverter interfaced distributed generation units contribute limited fault current and thereby the current magnitude-based protection schemes find limitation for such situations. Change in penetration level of renewable energy sources with time makes available protection schemes more challenging. The distinction between load and fault current is an issue and with high resistance fault, level of fault current and load current becomes comparable. In this paper, local measurement-based protection technique is proposed that uses current and voltage signals to derive accurate protection decision for a distribution system in the presence of distributed generation units. The method uses real and reactive power calculated at the relay point for the decision. The performance of the algorithm is tested for a 33 bus distribution system simulated using DIgSILENT PowerFactory. Considering such units, the method is tested for both islanded and grid-connected modes, the varying level of distributed generation penetration and for different fault resistances. The results demonstrate the strength of the proposed method over available techniques. The proposed method is also validated using hardware-in-loop testing using Arduino NANO microcontroller and OPAL-RT simulator in real-time.
关键词： DIgSILENT PowerFactory,protection technique,photovoltaic plants,Arduino NANO,OPAL-RT simulator,distributed generation units,local measurement
更新于2025-09-23 15:21:01