scholarly journals Designing of Fire Extinguisher Based on Sound Waves

The project titled Designing of Fire Extinguisher Based on Sound Waves is associated with new technique of fire extinguisher. Deals with the fire fighting operations with a quick response time. The purpose of sound wave extinguisher is to find out the range of frequency within which fire can be extinguished. It helps the fire fighter to fight the fire at early stage. Fire can be extinguished between 40Hz to 60Hz and the sound wave can extinguish the fire of all types of flames. The fire suppression needs to be done at the incipient stage where the heat and flame produced by the fire is at the minimum point. The expected outcome of the project will be, to counter the fire at its initial stage for better human safety and protection.

The project titled Design and Improvisation of Fire Fighting Bike is associated with new technique installed on the present firefighting bike. Deals with the firefighting operations with a quick response time.As identical in urban areas the narrow and crowded spaces where the movement of fire engines are not possible the bike plays the upper hand role and work as a life saver.The purpose of firefighting bike is to help the fire fighter to beat the traffic congestion and reach out the place of emergency within time.With all the required firefighting equipment required to overcome a concentrated fire. The fire suppression needs to be done at the incipient stage where the heat and flame produced by the fire is at the minimum point. The expected outcome of the project will be, to counter the fire at its initial stage for better human safety and protection


Author(s):  
C. Vannuffel ◽  
C. Schiller ◽  
J. P. Chevalier

Recently, interest has focused on the epitaxy of GaAs on Si as a promising material for electronic applications, potentially for integration of optoelectronic devices on silicon wafers. The essential problem concerns the 4% misfit between the two materials, and this must be accommodated by a network of interfacial dislocations with the lowest number of threading dislocations. It is thus important to understand the detailed mechanism of the formation of this network, in order to eventually reduce the dislocation density at the top of the layers.MOVPE growth is carried out on slightly misoriented, (3.5°) from (001) towards , Si substrates. Here we report on the effect of this misorientation on the interfacial defects, at a very early stage of growth. Only the first stage, of the well-known two step growth process, is thus considered. Previously, we showed that full substrate coverage occured for GaAs thicknesses of 5 nm in contrast to MBE growth, where substantially greater thicknesses are required.


2021 ◽  
Vol 2 (12(81)) ◽  
pp. 39-43
Author(s):  
M. Ibragimov ◽  
Y. Heydarova ◽  
A. Alizade ◽  
L. Ibragimova

This scientific article discusses the oral manifestations of diseases of the gastrointestinal tract. This problem is relevant both for dentists and family doctors. In medicine, for a long period of time, the relationship between diseases affecting the gastrointestinal tract and their symptoms manifested in the oral cavity has been considered. Many scientists and physicians have dealt with this problem, their several opinions are presented in this article. There is a hypothesis among researchers that the oral cavity is a mirror in which all human diseases can be visible. In the oral cavity, most of the alterations occurring in the organism are manifested, due to which, with an attentive attitude to oral manifestations, the disease can be detected already at the initial stage.


Author(s):  
Ying-Hui Jia ◽  
Fang-Fang Li ◽  
Kun Fang ◽  
Guang-Qian Wang ◽  
Jun Qiu

AbstractRecently strong sound wave was proposed to enhance precipitation. The theoretical basis of this proposal has not been effectively studied either experimentally or theoretically. Based on the microscopic parameters of atmospheric cloud physics, this paper solved the complex nonlinear differential equation to show the movement characteristics of cloud droplets under the action of sound waves. The motion process of individual cloud droplet in a cloud layer in the acoustic field is discussed as well as the relative motion between two cloud droplets. The effects of different particle sizes and sound field characteristics on particle motion and collision are studied to analyze the dynamic effects of thunder-level sound waves on cloud droplets. The amplitude of velocity variation has positive correlation with Sound Pressure Level (SPL) and negative correlation with the frequency of the surrounding sound field. Under the action of low-frequency sound waves with sufficient intensity, individual cloud droplets could be forced to oscillate significantly. The droplet smaller than 40μm can be easily driven by sound waves of 50 Hz and 123.4 dB. The calculation of the collision process of two droplets reveals that the disorder of motion for polydisperse droplets is intensified, resulting in the broadening of the collision time range and spatial range. When the acoustic frequency is less than 100Hz (@ 123.4dB) or the Sound Pressure Level (SPL) is greater than 117.4dB (@ 50Hz), the sound wave can affect the collision of cloud droplets significantly. This study provides theoretical perspective of acoustic effect to the microphysics of atmospheric clouds.


Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3674 ◽  
Author(s):  
Wei Lu ◽  
Yu Lan ◽  
Rongzhen Guo ◽  
Qicheng Zhang ◽  
Shichang Li ◽  
...  

A spiral sound wave transducer comprised of longitudinal vibrating elements has been proposed. This transducer was made from eight uniform radial distributed longitudinal vibrating elements, which could effectively generate low frequency underwater acoustic spiral waves. We discuss the production theory of spiral sound waves, which could be synthesized by two orthogonal acoustic dipoles with a phase difference of 90 degrees. The excitation voltage distribution of the transducer for emitting a spiral sound wave and the measurement method for the transducer is given. Three-dimensional finite element modeling (FEM)of the transducer was established for simulating the vibration modes and the acoustic characteristics of the transducers. Further, we fabricated a spiral sound wave transducer based on our design and simulations. It was found that the resonance frequency of the transducer was 10.8 kHz and that the transmitting voltage resonance was 140.5 dB. The underwater sound field measurements demonstrate that our designed transducer based on the longitudinal elements could successfully generate spiral sound waves.


1988 ◽  
Vol 108 ◽  
pp. 99-100
Author(s):  
Masa-aki Kondo

Concerning the scattering of OB stars in the HR diagram (Humphry 1980), the effects of overshooting of convective core (Maeder 1984), mass loss (cf. chiosi and Maeder 1986), and generous stability criterion of semi-convection (Stothers and Chin 1976) have been discussed. Here, we will note the dredge up effect is caused by the sound waves emitted from a convective core.The sound mode of nonradial oscillation, with the spherical harmonics Ylm(θ, ϕ) and the frequency ω, can exist in the propagation zone, where the bottom boundary locates at the position of , and the upper boundary does near the photosphere. Here, Ll is called as the Lamb frequency, and cs is the sound velocity.


2020 ◽  
Vol 7 (7) ◽  
pp. 505-510
Author(s):  
Sarang Choudhary ◽  
Aditi Gupta ◽  
Sudhanshu Sukhwal

2011 ◽  
Vol 63 (4) ◽  
pp. 921-932 ◽  
Author(s):  
Vesna Lackovic ◽  
Irena Tanaskovic ◽  
Dj. Radak ◽  
Vesna Nesic ◽  
Z. Gluvic ◽  
...  

Atherosclerosis represents a complex disease which encompasses all the components of the vascular wall. Nevertheless, according to all known theories of the pathogenesis of atherosclerosis, the key role in this process belongs to the endothelial cells, i.e. the changes that they are subjected to especially during the initial stage of the lesion. In this review we have attempted, according to the results of our continuous research and numerous data from available modern literature, to show the cytohistological characteristics of endothelial cells, as well as the changes they are subjected to in all stages of atherosclerosis. In the first part we have reviewed the ultrastructure, function and pathology of the endothelium, subcellular organization of the endothelial cells, their specific characteristics, micro compartments and intercellular junctions. In the second part we have described the morphological and functional changes of endothelial cells during atherosclerosis. Special attention is given to the role of endothelial cells in the development of the initial stage of lesion: endothelial dysfunction, factors that cause the increased expression of adhesion molecules in endothelial cells and mechanisms that cause leukocytes to migrate through the endothelial layer to subendothelial connective tissue in the early stage of atherosclerosis.


2020 ◽  
Author(s):  
Kyu Hye Choi ◽  
Han Hee Lee ◽  
Seung-Eun Jung ◽  
Kyung-Sin Park ◽  
Joo-Hyun O ◽  
...  

Abstract Background Early-stage primary gastrointestinal (GI) low-grade B-cell lymphoma shows good therapeutic response to primary radiotherapy. However, there is no clear guideline for the evaluation of response to radiation therapy currently. The aim of this study was to analyze the relationship between the best response time and the clinical course after radiotherapy. Methods Patients who underwent radiotherapy for treatment of primary GI low-grade B-cell lymphoma from September 2007 to December 2018 at Seoul St. Mary's Hospital were included. Early responders were defined by best response within 6 months after radiotherapy, and delayed responders after 6 months. Clinical and pathological factors associated with delayed response and survival analyses were performed to investigate the recurrence and survival during follow-up. Results A total of 43 patients were evaluated and the number of gastric mucosa-associated lymphoid tissue and duodenal follicular lymphoma was 36 and 7, respectively. All of 43 patients showed complete remission to radiotherapy and the best response time after radiotherapy was a median of 3 months. There were 8 delayed responders with a median duration of 8.9 months. Early and delayed responders were characterized by a significant difference in depth of invasion beyond the mucosal layer. Conclusions Delayed responders did not show differences in oncological outcomes compared with early responders. They were allowed to watch and wait for an additional 6 to 12 months without further treatment.


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