scholarly journals Characteristics of the Received Signal of an Ultrasonic Sensor Installed in a Chamber with Micro-Leakage

2021 ◽  
Vol 12 (2) ◽  
pp. 1051-1060
Author(s):  
Wonjun Seo ◽  
Seokyeon Im ◽  
Geesoo Lee
Keyword(s):  
High Pressure ◽  
Acoustic Impedance ◽  
Alternative Energy ◽  
Fossil Fuel ◽  
Pressure Change ◽  
Ultrasonic Waves ◽  
Ultrasonic Sensor ◽  
Sensor Signal ◽  
Distribution Method ◽  
Matching Layer

Abstract. As fossil fuel depletion and environmental pollution problems are becoming increasingly more serious, interest in the efficient use of natural resources and alternative energy is rapidly growing. In particular, interest in fuels stored as high-pressure gases such as natural gas and hydrogen is also rising. Ultrasonic waves show various received signals according to characteristics such as density of the medium and acoustic impedance. An experimental study on the detection of the micro-leakage of fuel stored as high-pressure gas was conducted based on the characteristics of ultrasonic waves. First, an ultrasonic sensor was manufactured by selecting the matching layer with consideration of the acoustic impedance. In the experiment, a mass flow controller (MFC) was attached to a perforated hole in the fabricated chamber to generate micro-leakage, and the signal from the receiving ultrasonic sensor was then collected. The envelope signal of the received ultrasonic sensor signal was analyzed through the Gaussian distribution method. The temperature inside the chamber and the received voltage decreased according to a similar trend and showed a nonlinear result. However, the phase of the received ultrasonic sensor signal showed a relatively linear result according to the internal pressure change. Micro-leakage could not be detected with only the received voltage seen by the ultrasonic sensor. Therefore, the phase shift of the receiving ultrasonic sensor can be used to detect micro-leakage in a high-pressure gas tank.

Energetic comparison of some stump-removing methods

2014 ◽  
Vol 10 (1) ◽  
pp. 35-51
Author(s):  
I. Czupy
Keyword(s):  
Alternative Energy ◽  
Fossil Fuel ◽  
Alternating Current ◽  
Above Ground Biomass ◽  
Alternative Energy Sources ◽  
Wide Domain ◽  
Fuel Substitution ◽  
Unused Resource ◽  
Root Connection ◽  
Different Soils

Concerns about climate change and fossil fuel shortages are encouraging interest in stumps, as alternative energy sources. Stumps are an almost unused resource in the context of bio fuels. Stump harvesting signifies an intensification of forest management compared with conventional stem-only or above-ground biomass-only harvesting. There are many benefits of stump harvesting. These include: the production of wood fuel, fossil fuel substitution, and improved soil preparation.Removing tree trunks in Hungary has been going on according to the principle of stump extraction, which means stumps are removed by grabbing technology. Experiments have been carried out to reduce the extraction force. In the Great Hungarian Lowland, where large areas require the operation implementation, stump extraction is done by special, hydraulic driven baggers equipped with a special bucket. During operation of the equipment, we carried out measurements of the extraction force and the time requirement. The experiments are designed to carry out the measurements with different soils and different tree species. According to our proposal the suitable force and torque required to remove stumps can be significantly reduced if before the lifting the soil — root connection is loosened. One of the possible ways to implement this task is the use of vibration. Since relatively great vibration power and wide domain of frequency are necessary, therefore we prepared the loosening machinery elements of alternating-current hydraulics system. Based on constructions variants we created a tractor-mounted experimental alternating-current hydraulic stump-loosening machine. It was designed with the ability to produce horizontal vibration in order to loosen stumps.

RENEWABLE ENERGY INTEGRATION FOR HOT WATER SUPPLY AND HEATING OF BUILDINGS

2021 ◽  
pp. 3-12
Author(s):  
Yu. Selikhov ◽  
K. Gorbunov ◽  
V. Stasov
Keyword(s):  
Solar Energy ◽  
Heat Production ◽  
Heat Supply ◽  
Alternative Energy ◽  
Fossil Fuel ◽  
Heat Pumps ◽  
Climatic Conditions ◽  
Economic Feasibility ◽  
Hot Water ◽  
The Cost

Solar energy is widely used in solar systems, where economy and ecology are combined. Namely, this represents an important moment in the era of depletion of energy resources. The use of solar energy is a promising economical item for all countries of the world, meeting their interests also in terms of energy independence, thanks to which it is confidently gaining a stable position in the global energy sector. The cost of heat obtained through the use of solar installations largely depends on the radiation and climatic conditions of the area where the solar installation is used. The climatic conditions of our country, especially the south, make it possible to use the energy of the Sun to cover a significant part of the need for heat. A decrease in the reserves of fossil fuel and its rise in price have led to the development of optimal technical solutions, efficiency and economic feasibility of using solar installations. And today this is no longer an idle curiosity, but a conscious desire of homeowners to save not only their financial budget, but also health, which is possible only with the use of alternative energy sources, such as: double-circuit solar installations, geothermal heat pumps (HP), wind power generators. The problem is especially acute in the heat supply of housing and communal services (HCS), where the cost of fuel for heat production is several times higher than the cost of electricity. The main disadvantages of centralized heat supply sources are low energy, economic and environmental efficiency. And high transport tariffs for the delivery of energy carriers and frequent accidents on heating mains exacerbate the negative factors inherent in traditional district heating. One of the most effective energy-saving methods that make it possible to save fossil fuel, reduce environmental pollution, and meet the needs of consumers in process heat is the use of heat pump technologies for heat production.

scholarly journals A Comparative Study on the Efficiency of CFRP and GFRP in the Improvement of Compressive Strength, Acoustic Impedance and Bracing of Filled and Hollow Concrete Columns in Different Layers and Ages

2016 ◽  
Vol 9 (5) ◽  
pp. 110 ◽  
Author(s):  
Mohammadreza Zarringol ◽  
Mohammadehsan Zarringol
Keyword(s):  
Compressive Strength ◽  
Comparative Study ◽  
Ultimate Strength ◽  
Acoustic Impedance ◽  
Concrete Columns ◽  
Concrete Surface ◽  
Ultrasonic Waves ◽  
Shear Strengthening ◽  
Surface Strength ◽  
Strengthening Method

<p>FRP technique is growing in popularity as a modern strengthening method. When it comes to FRP, concrete surface strength plays a determining role in the bond between FRP and concrete. This paper aims to compare the efficiency of CFRP and GFRP in the improvement of compressive strength, acoustic impedance and bracing of filled and hollow concrete columns in different layers and ages. In doing so, we carried out various tests on 18 samples in the ages of 3, 7, 14, 28, 42 and 90 days. According to the results, the strength of un-braced carbon and glass increased by 19-40% and 8-43% respectively and the strength of braced carbon and glass increased by 17-25% and 10-82% respectively. The compressive strength increased by 66% in one-layer CFRP hollow column, 96% in two-layer CFRP hollow column, 123% in three-layer CFRP hollow column, 36% in one-layer GFRP hollow column, 63% in two-layer GFRP hollow column, 105% in three-layer GFRP hollow column, 71% in one-layer CFRP filled column, 138% in two-layer CFRP filled column, 154% in three-layer CFRP filled column, 45% in one-layer GFRP filled column, 79% in two-layer GFRP filled column, and 144% in three-layer GFRP filled column. The ultimate strength of the beams with flexural-shear strengthening was higher than other beams. Also, the increased percentage of fiber resulted in the increased speed of ultrasonic waves. </p>

scholarly journals TECHNIQUE AND DEVICE FOR THE EXPERIMENTAL ESTIMATION OF THE ACOUSTIC IMPEDANCE OF VISCOELASTIC MEDIUM

2017 ◽  
Vol 8 (4) ◽  
pp. 314-326 ◽  
Author(s):  
O. V. Murav’eva ◽  
V. V. Murav’ev ◽  
D. V. Zlobin ◽  
O. P. Bogdan ◽  
V. N. Syakterev ◽  
...  
Keyword(s):  
Acoustic Impedance ◽  
Experimental Evaluation ◽  
Piezoelectric Element ◽  
Electric Circuit ◽  
Biological Tissues ◽  
Ultrasonic Waves ◽  
Acoustic Parameters ◽  
Laboratory Equipment ◽  
Viscoelastic Media ◽  
Silicone Sealant

Measuring the characteristics of process fluids allows us to evaluate their quality, biological tissues – to differentiate healthy tissues and tissues with pathologies. Measuring the characteristics of process fluids allows us to evaluate their quality, biological tissues – to differentiate healthy tissues and tissues with pathologies. One of the complex acoustic parameters is the impedance, which allows one to fully evaluate the characteristics of viscoelastic media. Most of impedance methods of measurements require using two or more reference media and the availability of calibrated acoustic transducers. The aim of this work ware introduced a methods and construction for the experimental evaluation of the longitudinal and shear impedance of viscoelastic media based on measuring the parameters of the amplitude-frequency characteristics and calculating the elements of the electric circuit for replacing the piezoelectric element which vibrating in the test medium.The paper introduces a methods and construction of the experimental evaluation of the impedances of viscoelastic media. The suggested methods is allowed measuring longitudinal and shear impedances and determining velocities of longitudinal and transverse ultrasonic waves and the values of the elastic moduli of viscoelastic media, including in various aggregate states. The technique is fairly simple to implement and can be reproduced using simple laboratory equipment.The obtained values of the acoustic impedances of the investigated media are in satisfactory agreement with their reference data. In contrast to the known methods for determining the acoustic impedance, the developed technique allows us to estimate with sufficient accuracy the parameter of the shear impedance of viscoelastic media that is difficult to measure at the frequencies of the megahertz range, which determines the shear modulus of the material and characterizes its resistance to shear deformations. The results of the implementation of the developed technique for the estimation of acoustic parameters for a number of media with zero shear elasticity (alcohol, acetone) and viscoelastic media (glycerin, architectural clay, silicone sealant and glue МР-55 before and after polymerization) are presented.

scholarly journals High Frequency Ultrasonic Wave Propagation in  Anisotropic Materials

2021 ◽  
Author(s):  
◽  
Andrew Paul Dawson
Keyword(s):  
Wave Propagation ◽  
Ultrasonic Wave ◽  
High Frequency ◽  
Guided Wave ◽  
Ultrasonic Waves ◽  
Tissue Characterisation ◽  
Ultrasonic Wave Propagation ◽  
Matching Layer ◽  
Fibrous Tissues ◽  
Wave Modes

<p>The influence of highly regular, anisotropic, microstructured materials on high frequency ultrasonic wave propagation was investigated in this work. Microstructure, often only treated as a source of scattering, significantly influences high frequency ultrasonic waves, resulting in unexpected guided wave modes. Tissues, such as skin or muscle, are treated as homogeneous by current medical ultrasound systems, but actually consist of highly anisotropic micron-sized fibres. As these systems increase towards 100 MHz, these fibres will significantly influence propagating waves leading to guided wave modes. The effect of these modes on image quality must be considered. However, before studies can be undertaken on fibrous tissues, wave propagation in more ideal structures must be first understood. After the construction of a suitable high frequency ultrasound experimental system, finite element modelling and experimental characterisation of high frequency (20-200 MHz) ultrasonic waves in ideal, collinear, nanostructured alumina was carried out. These results revealed interesting waveguiding phenomena, and also identified the potential and significant advantages of using a microstructured material as an alternative acoustic matching layer in ultrasonic transducer design. Tailorable acoustic impedances were achieved from 4-17 MRayl, covering the impedance range of 7-12 MRayl most commonly required by transducer matching layers. Attenuation coefficients as low as 3.5 dBmm-1 were measured at 100 MHz, which is excellent when compared with 500 dBmm-1 that was measured for a state of the art loaded epoxy matching layer at the same frequency. Reception of ultrasound without the restriction of critical angles was also achieved, and no dispersion was observed in these structures (unlike current matching layers) until at least 200 MHz. In addition, to make a significant step forward towards high frequency tissue characterisation, novel microstructured poly(vinyl alcohol) tissue-mimicking phantoms were also developed. These phantoms possessed acoustic and microstructural properties representative of fibrous tissues, much more realistic than currently used homogeneous phantoms. The attenuation coefficient measured along the direction of PVA alignment in an example phantom was 8 dBmm-1 at 30 MHz, in excellent agreement with healthy human myocardium. This method will allow the fabrication of more realistic and repeatable phantoms for future high frequency tissue characterisation studies.</p>

Classification of Iron Meteorites with High Frequency Ultrasonic Waves

2019 ◽  
Vol 24 (2) ◽  
pp. 277-284
Author(s):  
Dris El Abassi ◽  
Bouazza Faiz ◽  
Abderrahmane Ibhi ◽  
Idris Aboudaoud
Keyword(s):  
Phase Velocity ◽  
Acoustic Impedance ◽  
Nickel Content ◽  
Normal Incidence ◽  
Ultrasonic Pulse ◽  
Ultrasonic Waves ◽  
Iron Meteorites ◽  
Acoustic Transducer ◽  
Pulse Echo ◽  
Non Destructive

We present the results of an ultrasonic pulse-echo technique and its potential to classify iron meteorites into hexahedrites, octahedrites and ataxites by determining their acoustic impedance and phase velocity. Our technique has been adapted from those used in the field of ultrasonic non-destructive investigation of a variety of materials. The main advantage of our technique is that it does not need any preparation of the meteorites like cutting and etching and therefore is rapid, easy and non-destructive. In essence, a broadband acoustic transducer is used in a monostatic pulse-echo configuration which means that both the transducer and the meteorite sample are located in a water bath and adjusted in the way that the ultrasonic pulse shit the meteorite sample at normal incidence. Then the reflected pulses from the front and rear faces of the meteorite sample are measured with the emitting transducer, digitally recorded and processed to analyze the signal. After Fourier transforming the echoed pulses from the front and the rear face of the meteorite sample, the calculated reflection coefficients yield the phase velocity and the acoustic impedance. Our study investigates a variety of iron meteorites collected in Morocco and other countries and it helps to understand how the nickel content of these meteorites affects the acoustic impedance. It reveals that the acoustic impedance of iron meteorites increases with increasing nickel content, so that a further refinement of our technique might have the potential to classify iron meteorites directly and reliably into hexahedrites, octahedrites and ataxites without destroying them.

scholarly journals Oil Prices, Fossil-Fuel Stocks and Alternative Energy Stocks

2015 ◽  
Vol 7 (7) ◽  
Author(s):  
N. Alper Gormus ◽  
Ugur Soytas ◽  
J. David Diltz
Keyword(s):  
Alternative Energy ◽  
Fossil Fuel ◽  
Oil Prices

scholarly journals Myth v. Fact

2011 ◽  
Vol 133 (01) ◽  
pp. 24-29 ◽  
Author(s):  
John Reilly ◽  
Allison Crimmins
Keyword(s):  
Energy Demand ◽  
Alternative Energy ◽  
Nuclear Energy ◽  
Fossil Fuels ◽  
Fossil Fuel ◽  
Primary Energy ◽  
Electricity Production ◽  
Energy Prices ◽  
Primary Energy Demand ◽  
Business As Usual

This article predicts future global energy demand under a business-as-usual scenario. According to the MIT projections, conventional technology supported by fossil fuels will continue to dominate under a business-as-usual scenario. In fact, in the absence of climate policies that would impact energy prices, fossil fuels will supply nearly 80% of global primary energy demand in 2100. Alternative energy technologies will expand rapidly. Non-fossil fuel use will grow from 13% to 20% by 2100, with renewable electricity production expanding nearly tenfold and nuclear energy increasing by a factor of 8.5. However, those sources currently provide such a small share of the world's energy that even rapid growth is not enough to significantly displace fossil fuels. In spite of the growth in renewables, the projections indicate that coal will remain among the least expensive fuel sources. Non-fossil fuel alternatives, such as renewable energy and nuclear energy, will be between 40% and 80% more expensive than coal.

scholarly journals Widely used catalysts in biodiesel production: a review

RSC Advances ◽  
2020 ◽  
Vol 10 (68) ◽  
pp. 41625-41679
Author(s):  
Bishwajit Changmai ◽  
Chhangte Vanlalveni ◽  
Avinash Prabhakar Ingle ◽  
Rahul Bhagat ◽  
Lalthazuala Rokhum
Keyword(s):  
Energy Demand ◽  
Alternative Energy ◽  
Fossil Fuels ◽  
Fossil Fuel ◽  
Environmental Problems ◽  
Biodiesel Production

An ever-increasing energy demand and environmental problems associated with exhaustible fossil fuels have led to the search for an alternative energy. In this context, biodiesel has attracted attention worldwide as an alternative to fossil fuel.

Wind Potential Assessment for the Utilization from Wind Energy in the Household Level: A Case Study of Nakhonratchasima Thailand

2016 ◽  
Vol 835 ◽  
pp. 749-752
Author(s):  
Yuttachai Keawsuntia
Keyword(s):  
Wind Speed ◽  
Wind Energy ◽  
Alternative Energy ◽  
Energy Resource ◽  
Energy Utilization ◽  
Distribution Method ◽  
Household Level ◽  
Wind Speed Data ◽  
Wind Potential

Wind energy is an important alternative energy resource because of it clean, does not cause pollution and it can be used as replacement of a fossil fuel energy. Utilization of the wind energy, the wind speed data has to be analyzed to make sure before use it. In this article is to present the wind speed data analysis by using Weibull distribution method. Wind speed data from the meteorological station at Pakchong district, Nakhonratchasima province, Thailand was used as the case study. The results show that this area has wind speed about 2.5 to 3.5 m/s. The average wind power density was 17.513 W/m2 and the total wind energy was 153.9819 kW·hr/m2 per year. This wind potential of this area can be used for water pumping and electricity generating for use in a household.

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