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Design, and optimization of ultrasonic reactors are important objectives in sonochemical processing. The recent expansion of the use of ultrasonic reactors in various research areas all faces the problem of scaling up from laboratory results to industrial purposes. A traditional ultrasonic reactor usually has several issues, such as low effectiveness as well as complex and unstable system performance,...
The impedance of sample 18650 format cylindrical lithium ion battery cells has been measured over the frequency range from 100 kHz to 200 MHz using a vector network analyser. The results indicate that these cells exhibit a small resistance and inductive reactance, both reaching around 2 Ω at 200 MHz, which do not vary significantly when generating a DC current.
Design and optmiziation of ultrasonic reactors are important objectives in sonochemical processing. The recent expansion of the use of ultrasonic reactors in various research projects all faces the problem of scaling up laboratory results for industrial use. A traditional ultrasonic reactor usually has several issues, such as low effectiveness and complex and unstable system performance, which all...
Cortical bone porosity (Ct. Po) and pore diameter (Po. Dm) are important factors in determining bone toughness and strength [1–2]. However, the current standard diagnosis, dual-energy X-ray absorptiometry (DXA), doesnot have the sensitivity to those factors. Due to the strong specular reflection from the bone surface and high acoustic attenuation of cortical bone tissue, conventional ultrasound is...
In this paper, we report the development of miniaturized forward-looking transducers for microbubble-mediated intravascular ultrasound-enhanced thrombolysis (UET). UET has shown its efficacy for thrombo-occlusive disease by enhancing penetration of thrombolytic drugs into clots, reducing the required dose. In this study, we adopted a previously-developed forward-looking, stacked type transducer for...
Current IVUS probe utilizes an outer proximal motor and a flexible drive shaft transmitting rotational motion through the bending vessel segment. However, the load-bearing shaft through the long bending vessel generally rotates at unstable speed, leading to image distortions. One way to overcome the drawback is to develop a self-spin transducer driven by a micro motor inside the probe. In this study,...
Sub-diffraction imaging, also known as super-resolution (SR) imaging, is a novel method that can overcome the fundamental diffraction limit by localizing spatially isolated microbubbles (MBs). A low concentration of MBs is required to achieve isolated signals in microvasculature, which is especially challenging in cancerous tissue due to high vessel density and slow flow. This study proposes a frequency...
The phase transition of nanodroplet has great potential in localized therapy, e.g. gas embolotherapy, drug delivery and the extravascular tumor-targeted theranostics. To improve the temporal and spatial resolution and reduce the energy threshold of nanodroplet phase transition, photoacoustic cavitation (PAC) using synergistic laser and ultrasound was introduced and compared with acoustic droplet vaporization...
The purpose of this investigation is to present a Ku-Band Helix Traveling Wave Tube Amplifier (TWTA) design and simulation procedure with considering initial design assumptions. The design process which consists of four critical steps is stated. Firstly, required input parameters such as dc beam current (Io), dc beam voltage (Vo) and frequency band of operation are chosen. Determination of the design...
This paper illustrates the design, implementation and modelling of the extensor pneumatic muscle actuator (PMA). The extensor soft actuator has a vital feature of ability to bend and extend, and that give it the flexibility to use in numerous applications. The extended behaviour of this actuator is modelled mathematically to be used to predict the length of a wide range of actuators at different air...
The article represents vortex progressive equipment, which allows to generate nanoporous structure either on the surface of ammonium nitrate granules, or inside them. Therefore there is a possibility to get pores of various sizes in the inner, central and outer layers of granules. The engineering calculation algorithm of vortex granulator is investigated. The research results show that vortex devices...
The high voltage condenser bushing is a critical component found in all electrical networks and whose failure can have serious consequences. Thermal and electrical stresses, ambient conditions, and other factors place high demands on bushings. Proper condition assessment is essential to maintain a high system availability. The most commonly used advanced tools are the Dielectric Frequency Response...
Experiments with real-world non-NIR illumination as well as wavelength-specific acquisition settings are conducted with respect to impact on iris recognition performance, in particular considering variations in genuine score distribution. Illumination includes daylight, light bulbs, fluorescent tubes, halogen lamps, and mixed modes, while acquisition is done in visible wavelength, near infrared wavelength,...
Falling sphere viscometer is one of the most commonly used techniques in experimentally determining fluid viscosity. This method requires the measurement of the terminal velocity of a falling sphere inside the fluid, which remains a challenging and costly task, especially if high precision is required. This paper presents the development of a low-cost visionbased falling sphere viscometer. The velocity...
The public transports provide an ideal means to enable contagious diseases transmission. This paper introduces a novel idea to detect co-location of people in such environment using just the ubiquitous geomagnetic field sensor on the smartphone. Essentially, given that all passengers must share the same journey between at least two consecutive stations, we have a long window to match the user trajectory...
The rhodium-carbon (Rh-C) eutectic-point (1657 °C) cell having an outer diameter of 44 mm and a height of 297 mm was constructed for thermocouple calibration. The melting and freezing curves at the Rh-C eutectic point were evaluated using type R thermocouples. The repeatability of the melting and freezing curves, the effect of the surrounding temperature, and the heat flux effect in the cell were...
The Concentrated Solar Power — CSP — has been used to generate electricity since 70s. However, on Brazil the technology is still under development, and even though there are not commercial power plants installed, many studies and some research projects are being developed to establish the feasibility of this technology. This paper presents a general analysis of CSP economic aspects influenced by its...
Millions of surveillance cameras operate at 24×7 generating huge amount of visual data for processing. However, retrieval of important activities from such a large data can be time consuming. Thus, researchers are working on finding solutions to present hours of visual data in a compressed, but meaningful way. Video synopsis is one of the ways to represent activities using relatively shorter duration...
The heightened utilization of ionizing radiation for diagnostic and beneficial purposes, the expeditious progress in nuclear reactors, as well as the risks of radioactive waste have raised significant safety and health concerns for the people working with radiation and the general public. While some exposure to radiation is acceptable, radiation monitoring should be done to keep the levels of radiation...
We describe a traveling wave terahertz (0.75–1.1 THz) amplifier that uses a meandering TE01 waveguide coupled to a plasma beam and discuss its design, microfabrication, and cold/hot tests. Motivations for using plasmas instead of electron beams are: 1) thermionic emission required in e-beam generation can be replaced with gas ionization, 2) electrostatic lenses and magnetic focusing structures can...
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