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A new metal-organic hybrid crystal with excellent transparency in the visible spectrum: Growth, structure and properties of sodium fumarate – Boric acid tetrahydrate
摘要： Single crystals of sodium fumarate-boric acid tetrahydrate (SBF) were grown by a slow evaporation solution technique. The crystal belongs to orthorhombic lattice system. Identification of the functional groups and the nature of bonding involved in this crystal were elucidated by FTIR. The crystal is transparent in the entire visible region with a lower cutoff around 384 nm and the band gap of 5.5 eV. The photoactive material can have the ability to emit fluorescent radiation in the wavelength range of 490 nm. The hydrated crystal is thermally stable; in the receipt of dehydration it loses its stability. The mechanically soft natured crystal obeys the reverse indentation size effect for the applied loads. The elevated dielectric constant and dielectric loss are assisted by the hydrated water and it diminished as the material dehydrates at higher temperature. The slower motion of the dipole induces frequency of the applied field and hence the impedance decreases with increasing frequency.
关键词： soft nature,FTIR,Fluorescent,RISE
更新于2025-09-23 15:23:52
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Comparison between Ferromagnetic and Ferroelectric Optical Switch Devices in Terms of the Response to the Electric Field
摘要： In this work we have studied the electro-optical effect of two types of ferronematic nanoparticles. The first sample doped with magnetic material Fe3O4 and the second sample doped with a ferroelectric material SbSI. The difference in the two types of material that has been vaccinated led to different values of electro-optic properties because of the different susceptibility of materials. We have noticed that the material SbSI was more responsive to the applied electric field due to the nature of the constituent material (electric material) than the Fe3O4 ferromagnetic. The response time for the material SbSI is less than the response time of the ferromagnetic Fe3O4, that led to make the material SbSI best in the optical switch applications.
关键词： Electro-Optic Properties,Response Time,Fall Time,Rise Time,Ferronematic (FN),Threshold Voltage
更新于2025-09-23 15:22:29
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Rise and side infiltration in opals and porous materials for their skin-free replica synthesis
摘要： A floating opal placed on a certain liquid will cause the liquid to climb through the opal gaps, fill all its pores, and stop almost of its upper surface without covering it. A drop of solution with a surface tension much lower than that of water, deposited on a hydrophilic substrate near an opal, rapidly spread over a large surface forming a film which will surround the opal and infiltrate it from the side without covering it. High quality, skin-free, inverse opals can be synthesized by rise and side infiltration of solution in opals. The overlayer absence leads to the fabrication of mechanically robust, crack-free, completely filled photonic crystals which preserve the long rage order of initial opals. Inverse opals of sodium silicate were synthesized starting from polystyrene nanospheres self-assembled through hanging drop technique followed by their rise and side infiltration, casting, and template removal. Crystalline material inverse opals such as glycine, sodium chloride, and sulfur were also synthesized.
关键词： skin-free,photonic crystals,inverse opals,rise infiltration,porous materials
更新于2025-09-23 15:19:57
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Research on optimum slowly-rising driver for electro-optic Q-switched laser
摘要： Electro-optic Q-switch drivers that based on pulse transformer method have been widely used in laser engineering because of the advantages of concise circuits, low supply voltage, low lost, etc., but the long rise time and short pulse duration of the high voltage (HV) pulses have a considerable effect on the Q-switched laser outputs. In this paper, we experimentally investigated the dependence of Q-switched laser outputs on the rise rate of slowly-rising HV pulses in a flash pumped Nd:YAG laser with variable cavity lengths. LiNbO3 Q-switches with various dimensions were used. Based on the experiment results, the optimum slowly-rising HV pulses for any EO Q-switched laser were derived, the only requirement is that voltage near dynamic quarter-wave voltage during the emission of laser pulses. Additionally, the optimum outputs were found to be consistent with the results obtained by using a rapid-switching driver with a rise time of 7 ns. The optimum range of applied voltage was determined to be 0.88 – 1.12 times dynamic quarter-wave voltage.
关键词： Electro-optic Q-switching,Lithium niobate crystal,Slow rise time,Q-switch driver,Pulsed laser
更新于2025-09-19 17:13:59
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Direct molecular-level near-field plasmon and temperature assessment in a single plasmonic hotspot
摘要： Tip-enhanced Raman spectroscopy (TERS) is currently widely recognized as an essential but still emergent technique for exploring the nanoscale. However, our lack of comprehension of crucial parameters still limits its potential as a user-friendly analytical tool. The tip’s surface plasmon resonance, heating due to near-field temperature rise, and spatial resolution are undoubtedly three challenging experimental parameters to unravel. However, they are also the most fundamentally relevant parameters to explore, because they ultimately influence the state of the investigated molecule and consequently the probed signal. Here we propose a straightforward and purely experimental method to access quantitative information of the plasmon resonance and near-field temperature experienced exclusively by the molecules directly contributing to the TERS signal. The detailed near-field optical response, both at the molecular level and as a function of time, is evaluated using standard TERS experimental equipment by simultaneously probing the Stokes and anti-Stokes spectral intensities. Self-assembled 16-mercaptohexadodecanoic acid monolayers covalently bond to an ultra-flat gold surface were used as a demonstrator. Observation of blinking lines in the spectra also provides crucial information on the lateral resolution and indication of atomic-scale thermally induced morphological changes of the tip during the experiment. This study provides access to unprecedented molecular-level information on physical parameters that crucially affect experiments under TERS conditions. The study thereby improves the usability of TERS in day-to-day operation. The obtained information is of central importance for any experimental plasmonic investigation and for the application of TERS in the field of nanoscale thermometry.
关键词： surface plasmon resonance,nanoscale thermometry,Tip-enhanced Raman spectroscopy (TERS),spatial resolution,near-field temperature rise
更新于2025-09-19 17:13:59
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High-speed infrared imaging and mesostructural analysis of localized temperature rise in damage and failure behavior of 3-D braided carbon/epoxy composite subjected to high strain-rate compression
摘要： This investigation is aimed to study the dynamic failure behavior of 3-D braided carbon/epoxy composite by capturing the high-speed infrared image and simulating the temperature-rise response under high strain-rate compression. It is found that localized temperature rise is a good indication in damage and failure of the 3-D braided composite. Localized temperature can rise above a hundred degrees Celsius, reaching or even exceeding the Tg of the matrix resin and imperiling the polymer along damage regions in specimen. Temperature rise in localized paths of the specimens was caused by adiabatic shear along the boundaries of braided fibers or inside the fiber bundles. Sustaining decrease in stress after the peak strength is related to shear deformation, temperature rise and progressive damage. There is a correlation among localization of temperature rise, adiabatic shear band, resin softening, damages and failures in the 3-D braided carbon/epoxy composite under dynamic compression loading. For the out-of-plane compression, temperature always conducts from the broken interface to the inside of the fiber bundles along the radial, which will lead to the weakening of resin in fiber bundles. And damages, penetrating cracks and openings are verified with ‘X’-shape localization of temperature rise. With the increase of strain rate, localization of temperature rise indicates that adiabatic shear bands begin to connect together to form larger and longer paths by the mutual shear effect among adjacent fiber bundles. For the in-plane compression, multi-cracks are found by observing the independent ‘zigzag’ shear bands converting to dependent ‘zigzag’ network. The temperature is easily localized at the crimp position of fiber bundle when they forming the ‘zigzag’ localization along the braiding paths of fiber bundles. However, some regions in 3-D braided carbon/epoxy composite have not experienced plastic shear deformation, which are isolated among ‘zigzag’ adiabatic shear network and their boundaries are the very paths for localized temperature rise.
关键词： High strain-rate compression,Braided composite,Adiabatic temperature rise,Thermomechanical failure
更新于2025-09-19 17:13:59
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Line-End Voltage and Voltage Profile along Power Distribution Line with Large-Power Photovoltaic Generation System
摘要： In recent years, the introduction of the photovoltaic generation system (PV system) has been increasing by promoting the use of renewable energy. It has been feared that the reverse current from the PV system may cause an unacceptable level of voltage rise at the interconnection node in the power distribution system. This paper discusses the e?ects of the reverse current on the voltage rise and fall characteristics of the interconnection node and the voltage pro?les along the power distribution line. When the line current on the circuit is small, the voltage on the line monotonically increases from the sending end to the receiving end. When a relatively large current ?ows, it causes a voltage reduction near the distribution substation. Furthermore, on the basis of the voltage aspects in the power distribution system with a large PV system, the allowable limits of the line current and the output power from PV system are investigated.
关键词： photovoltaic generation system,voltage rise,reverse current,power distribution system,voltage profile
更新于2025-09-16 10:30:52
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[IEEE 2019 International Conference on Information and Communications Technology (ICOIACT) - Yogyakarta, Indonesia (2019.7.24-2019.7.25)] 2019 International Conference on Information and Communications Technology (ICOIACT) - Optical Fiber Network Design in East Nusa Tenggara Based on Palapa Ring Project
摘要： Bandwidth capacity and high data rates improvement in Eastern Indonesia become an important aspects in empowering communities that is aimed to facilitating access to information in various sectors. The East Palapa Ring Package project was launched by the Ministry of Communication and Information to meet these needs. The design of optical fiber networks in East Nusa Tenggara Province was carried out in this study to support that project. This province is one of the area that has a high data rates needs especially for the security and tourism sector, because its territory is directly adjacent to other countries and has a high potential of tourism there. A total of 22 routes connecting districts / cities in East Nusa Tenggara were proposed by using Power Link Budget and Rise Time Analysis. From the results, it is known that the Power Loss and Dispersion Time in the proposed network do not exceed the permitted limits, which are 53 dBm and 233.33 ps respectively. Therefore, the proposed optical fiber network is in accordance with the expected and feasible targets to be carried out.
关键词： rise time analysis,optical fiber network,palapa ring project,link budget analysis
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Study on Temperature Rise Characteristic of LED Lighting Fixture under Different Conditions
摘要： The temperature rise characteristic of LED lighting fixture under different conditions was studied in the paper. The experimental results showed that the temperature rise of LED lighting fixture under the condition of with cover and no dust was about 1.5 times higher than that of LED lighting fixture under the condition of no cover and with dust. Apparently, the influence of the cover on the heat dissipation of LED lighting fixture was much larger than the dust.
关键词： Cover,Thermal Resistance,Temperature Rise,Heat Dissipation,LED lighting fixture,Dust
更新于2025-09-16 10:30:52
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Comparison of the Amount of Temperature Rise in the Pulp Chamber of Teeth Treated With QTH, Second and Third Generation LED Light Curing Units: An In Vitro Study
摘要： Introduction: This in vitro study was designed to measure and compare the amount of temperature rise in the pulp chamber of the teeth exposed to different light curing units (LCU), which are being used for curing composite restorations. Methods: The study was performed in two settings; first, an in vitro and second was mimicking an in vivo situation. In the first setup of the study, three groups were formed according to the respective three light curing sources. i.e. quartz-tungsten-halogen (QTH) unit and two light-emitting diode (LED) units (second and third generations). In the in vitro setting, direct thermal emission from three light sources at 3 mm and 6 mm distances, was measured with a k-type thermocouple, and connected to a digital thermometer. For a simulation of an in vivo situation, 30 premolar teeth were used. Class I Occlusal cavity of all the teeth were prepared and they were restored with incremental curing of composite, after bonding agent application. While curing the bonding agent and composite in layers, the intrapulpal temperature rise was simultaneously measured with a k-type thermocouple. Results: The first setting of the study showed that the heat produced by irradiation with LCU was significantly less at 6 mm distance when compared to 3 mm distance. The second setting of the study showed that the rise of intrapulpal temperature was significantly less with third generation LED light cure units than with second generation LED and QTH light cure units. Conclusion: As the distance from the light source increases, less irradiation heat is produced. Third generation LED lights cause the least temperature change in the pulp chamber of single rooted teeth.
关键词： LED dental curing lights,temperature,QTH units,LED lights,pulp chambers,third generation LED lights,intrapulpal temperature rise
更新于2025-09-11 14:15:04