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Stable and compact nanosecond pulse seed source with diode laser driven by a high-speed circuit and a temperature control circuit
摘要： We demonstrated a nanosecond pulse seed source with a diode laser (DL) of 1550 nm A short pulse generator and a short pulse driver came to form a high-speed circuit that drove the seed source. A temperature control circuit was employed to control the stability of the laser pulses. The experimental results provided that continuously adjustable 5 kHz to 25 MHz repetition frequency and 3.5 ns to 51 ns pulse duration were acquired. The ?ne tuning of pulse duration of seed signals was realized by adjusting the current of the laser in its operating current range. Stability of the output power over two hours was 0.13% at repetition frequency of 25 MHz and pulse duration of 3.5 ns, respectively.
关键词： Short pulse generator,Temperature control,Short pulse driver,Pulse seed source,Nanosecond pulse
更新于2025-11-28 14:24:03
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A spark discharge generator for scalable aerosol CVD synthesis of single-walled carbon nanotubes with tailored characteristics
摘要： We have designed and built an exhaust-free spark discharge generator for robust aerosol CVD synthesis of single-walled carbon nanotubes. The systematic study has shown the generator to provide a facile and repeatable route to precisely control the size of the catalyst particle and, therefore, carbon nanotube growth. Using a comprehensive set of methods (the analysis of differential mobility of the aerosol particles, optical spectroscopy, scanning and transmission electron microscopy, Raman spectroscopy, and atomic force microscopy) we have revealed the relation between the defectiveness, length, diameter distribution of carbon nanotubes and specific features of a generator such as electrode characteristics (breakdown voltage, composition, and current) as well as the nature of the surrounding media (carrier gas nature, flow rate). The design used has resulted in separation of the nanoparticle formation and carbon nanotube nucleation processes. This provides a mutual independence of the growth parameters and the diameter distribution of the single-walled carbon nanotubes enhancing the scalability of the process. For instance, the breakdown voltage has been shown to have nearly zero effect on diameter and length distribution of carbon nanotubes produced while strictly governing the yield. We focus here on producing specifically short carbon nanotubes (l < 500nm) of pronounced defectiveness for drug delivery and transistor applications.
关键词： single-walled carbon nanotubes,differential mobility analyzer,catalyst activation,spark-discharge generator,aerosol CVD,floating bed reactor
更新于2025-11-14 17:03:37
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[IEEE 2018 2nd School on Dynamics of Complex Networks and their Application in Intellectual Robotics (DCNAIR) - Saratov, Russia (2018.10.8-2018.10.10)] 2018 2nd School on Dynamics of Complex Networks and their Application in Intellectual Robotics (DCNAIR) - Autonomous Power Supply System of Magnetron Generators Group
摘要： The issues which emerge at autonomous power supply system development are considered. The objects of power supply are magnetron generators groups as part of technological complex with a distributed supply of microwave energy.
关键词： solar panels,wind generator,power supply system,diesel generator,magnetron
更新于2025-09-23 15:23:52
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[IEEE 2018 19th International Conference of Young Specialists on Micro/Nanotechnologies and Electron Devices (EDM) - Erlagol (Altai Republic), Russia (2018.6.29-2018.7.3)] 2018 19th International Conference of Young Specialists on Micro/Nanotechnologies and Electron Devices (EDM) - The System of Frequency Matching of the Ultrasonic Generators with the Radiators in “Bulava” Apparatuses
摘要： The article is devoted to the problem concerned with the determination of resonance frequency of the ultrasonic vibrating systems (the radiators) intended for the operation as a part of the ultrasonic technological apparatuses of “Bulava” type.
关键词： frequency control system,generator,resonance matching,Ultrasound
更新于2025-09-23 15:23:52
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Surface potential tailoring of PMMA fibers by electrospinning for enhanced triboelectric performance
摘要： Triboelectric generators rely on contact-generated surface charge transfer between materials with different electron affinities to convert mechanical energy into useful electricity. The ability to modify the surface chemistry of polymeric materials can therefore lead to significant enhancement of the triboelectric performance. Poly(methyl methacrylate) (PMMA) is a biocompatible polymer commonly used in medical applications, but its central position on the triboelectric series, which empirically ranks materials according to their electron-donating or electron accepting tendencies, renders it unsuitable for application in triboelectric generators. Here, we show that the surface potential of PMMA fibers produced by electrospinning can be tailored through the polarity of the voltage used during the fabrication process, thereby improving its triboelectric performance, as compared to typically spin-coated PMMA films. The change in surface chemistry of the electrospun PMMA fibers is verified using X-ray photoelectron spectroscopy, and this is directly correlated to the changes in surface potential observed by Kelvin probe force microscopy. We demonstrate the enhancement of triboelectric energy harvesting capability of the electrospun PMMA fibers, suggesting that this surface potential modification approach can be more widely applied to other materials as well, for improved triboelectric performance.
关键词： Energy harvesting,Triboelectric generator,Surface chemistry,Kelvin probe force microscopy,Electrospinning,Poly(methyl methacrylate)
更新于2025-09-23 15:23:52
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[IEEE 2018 Conference on Electrotechnology: Processes, Models, Control and Computer Science (EPMCCS) - Kielce, Poland (2018.11.12-2018.11.14)] 2018 Conference on Electrotechnology: Processes, Models, Control and Computer Science (EPMCCS) - Investigation and Determination of Efficiency of the Waste Heat Recovery System Using Peltier Modules
摘要： High efficiency technology of waste heat energy utilization would change the face of the energy market. Due to the fact that the energy system and transport are based on fossil fuels, there is a huge potential for its efficient use. Despite the fact that the technology of Peltier semiconductor modules has been known for many years, there are no solutions that might be commonly disseminated. There is also a deficit of available sources that in a transparent, coherent and synthetic way could provide guidelines for the constructors of such devices, and show how much energy they can generate and what efficiency they have. Moreover, the Peltier modules available on the market are burdened with many stereotypes. When trying to use this technology, it should be remembered that in addition to the Peltier phenomenon, the module's operation is based on four other physical phenomena: two of them have a negative impact and they determine the practically obtained parameters of the Peltier module. These are: Joule effect and heat conduction phenomenon. The other two phenomena: Seebeck and Thomson ones, play slightly smaller roles. The aim of the authors was to investigate the self-made model of a thermoelectric generator TEG, constructed using Peltier modules. The paper presents the results of measurements and the method of determining the electrical efficiency of this model. Additionally, a temperature range was determined at that such recovery has a measurable utilitarian aspect and economic sense. The limitations of semiconductor technology of Peltier cells have been given, and design guidelines at construction process of such systems to optimize their efficiency are presented.
关键词： Seebeck effect,thermoelectric generator TEG,determination of efficiency,Peltier module
更新于2025-09-23 15:23:52
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High Bandwidth Non-Resonant High Voltage Generator for X-Ray Systems
摘要： High-voltage supplies for medical X-ray systems require up to 150 kV DC at up to 100 kW to supply the tube. The challenge for the power supply however is not only to deal with the high voltage and high power demand, but also to provide short voltage rise- and fall times in the range of 100μs. A coupled interleaved circuit variant of a single active bridge concept, the coupled interleaved single active bridge converter, is demonstrated in this work providing very fast output voltage control due to its non-resonant structure. The conduction modes of the circuit are analysed in detail and compared to the uncoupled interleaved single active bridge approach, demonstrating the advantages of low inverter RMS current, zero voltage switching (or at least zero current switching) over the full operating range with constant switching frequency. Analytic expressions for the output current-duty cycle relationship are provided. Experiments on a 60 kW (low voltage equivalent) prototype show that rise times as low as five switching cycles are possible, allowing to reach the target of 100μs rise time using a switching frequency of only 50 kHz.
关键词： DC-DC power conversion,high bandwidth,high voltage generator,X-ray generator
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE Industry Applications Society Annual Meeting (IAS) - Portland, OR, USA (2018.9.23-2018.9.27)] 2018 IEEE Industry Applications Society Annual Meeting (IAS) - Design and Control of Solar PV-Pico Hydro Based Microgrid
摘要： This study deals with a solar photovoltaic (PV) and pico-hydro based microgrid having a battery energy storage (BES), which transfers uninterruptable power across voltage source converter (VSC) at the common coupling point (CCP). Only one VSC in this system, has the competency to eradicate the power quality problems, compensation of harmonics current, regulation of frequency and voltage under varying loads. A battery energy storage (BES), which is coupled directly to the DC bus, manages the power flow under the changes in loading and variable power generation. A synchronous reluctance generator (SYRG) for pico-hydro generation is used because of its reliability, and cost-effectiveness than other such as permanent magnet brushless generators synchronous generator. The SRFT (Synchronous Reference Frame Theory) control is used to control the system frequency and voltage at PCC. The proposed system uses an INC (Incremental Conductance) technique for extraction of maximum power from a PV array. The smooth performance of the microgrid under various operating conditions, is demonstrated through experimental results, which meet power quality requirement of the IEEE 519 standard.
关键词： Pico-Hydro generation,BES (Battery Energy Storage),Microgrid,SyRG (Synchronous Reluctance Generator),PV (Photovoltaic),Power Quality
更新于2025-09-23 15:22:29
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[IEEE 2018 International Flexible Electronics Technology Conference (IFETC) - Ottawa, ON, Canada (2018.8.7-2018.8.9)] 2018 International Flexible Electronics Technology Conference (IFETC) - A Comparitive Study of On-Chip Clock Generators Using a-IGZO TFTs for Flexible Electronic Systems
摘要： This paper presents a comparitive study of ring oscillators (RO) using amorphous Indium Gallium Zinc Oxide (a-IGZO) thin-film transistors (TFTs) to implement on-chip clock generator for flexible electronic systems. A five-stage RO has been implemented with different inverter topologies using IGZO TFTs, which includes Diode connected load, Capacitive bootstrapping (BS), Pseudo-CMOS and Pseudo-CMOS bootstrapping architectures. These topologies have been simulated using in-house IGZO TFT models under similar conditions using different power supplies (10 V, 15 V and 20 V) in cadence environment. Among all architechtures Capacitive bootstrapping RO has ensured highest frequency of operation in the order of MHz and an output swing of 82% of VDD. Whereas, Pseudo-CMOS based RO provides the lowest power consumption in the order of μW with an output swing of 57% of VDD. On the other hand, the combination of Pseudo CMOS and bootstrapping has ensured highest voltage swing of 95% of VDD. In terms of power delay product (PDP) BS RO is superior with respect to other topologies. This work provides a clear insight to the designer to choose a particular topology for given application, mainly for on-chip clock generation for flexible electronic systems based on the requirements.
关键词： Bootstrapping,Ring Oscillator,Flexible on-chip clock generator,Pseudo-CMOS,a-IGZO TFTs
更新于2025-09-23 15:22:29
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Microfluidic Long-Term Gradient Generator with Axon Separation Prototyped by 185 nm Diffused Light Photolithography of SU-8 Photoresist
摘要： We have developed a cast micro?uidic chip for concentration gradient generation that contains a thin (~5 μm2 cross-sectional area) microchannel. The diffusion of diffused 185 nm ultraviolet (UV) light from an inexpensive low-pressure mercury lamp exposed a layer of the SU-8 photoresist from the backside and successfully patterned durable 2 μm-high microchannel mold features with smooth bell-shaped sidewalls. The thin channel had appropriate ?ow resistance and simultaneously satis?ed both the rapid introduction of test substance and long-term maintenance of gradients. The average height and width at the half height of the channel, de?ned by a 2 μm-wide line mask pattern, were 2.00 ± 0.19 μm, and 2.14 ± 0.89 μm, respectively. We were able to maintain the concentration gradient of Alexa Fluor 488 ?uorescent dye inside or at the exit of the thin microchannel in an H-shaped micro?uidic con?guration for at least 48 h. We also demonstrated the cultivation of chick embryo dorsal root ganglion neuronal cells for 96 h, and the directional elongation of axons under a nerve growth factor concentration gradient.
关键词： prototyping,axon elongation,micro?uidic gradient generator,SU-8,microchannel
更新于2025-09-23 15:22:29