scholarly journals Experimental Study on Measurement of Time to Reach Ignition Point Based on Installation of Addressable Detector in Traditional Market

2020 ◽  
Vol 20 (5) ◽  
pp. 113-122
Author(s):  
Jiman Lee ◽  
Semyeoung Lee

Because fire in a traditional market spreads very fast, it is necessary to install an alarm system that can detect the fire early and identify the exact ignition point. The addressable detector can be used to identify the ignition point quickly using the address function. In this study, an existing general-type detector installed in a traditional market was replaced with an addressable detector, and firefighters measured the time taken to reach the initial ignition point. From the experimental results, the average time taken from DaeSin 119 Safety Center to reach the virtual ignition point on the 2<sup>nd</sup> floor of the 2<sup>nd</sup> district of Seomun Market was 3 min 12 s when the <general-type detector-P-type receiver> system was applied. However, the time was 2 min 8 s when the <addressable-type detector-R-type receiver>system was applied. Based on the experimental investigation, it was confirmed that the time required for firefighters to reach the initial ignition point decreased when the existing general-type detector was replaced with the addressable detector.

Author(s):  
Houda Hachem ◽  
Ramla Gheith ◽  
Fethi Aloui ◽  
Sassi Ben Nasrallah

Considering Stirling engines modern applications and cogeneration recovery energy from industrial process, the power of a Stirling prime mover is to be provided at a speed of rotation adapted to the operation of the receiver system (usually a generator) to exploit the performance of this machine under the conditions of its use (ie lowering of the rotational speed and torque transmitted rise or, more rarely, elevated speed and lowering the torque transmitted). Knowing that the hot air engine cannot change speed quickly and in order to have a well designed system, it is important to study the unsteady state conditions. In this work we present an experimental stability analysis of an irreversible heat engine working at different conditions. The experimental study aims at analyzing the effect of working parameters disruption on the stability of the Gamma Stirling engine. Parameters involved in this experimental study are the load pressure of the motor and the load applied to the Stirling engine. The influence of engine operating parameters on its torque and rotational speed is investigated. The time required by a gamma type Stirling engine to stabilize operation after disruption is estimated. Results show that after a small disruption, speed and temperature evolutions decays exponentially to the steady state determined by a relaxation time. It is assumed that the decrease of the applied power load to the engine or the increase of the load pressure leads to a speed up. And that the increase of the applied power load to the engine or the decrease of the load pressure leads to a speed down.


2002 ◽  
Vol 21 (1) ◽  
pp. 79-93 ◽  
Author(s):  
Jack L. Krogstad ◽  
Mark H. Taylor ◽  
Maribeth J. Stock

This experimental study investigates the efficacy of lawyers' letters in providing auditors with corroborating evidence about litigation contingencies. Fifty second- and third-year law students indicate their willingness to provide auditors with estimates of the likelihoods of unfavorable outcomes and potential damages for two realistic litigation cases. The findings indicate that (1) the potential loss of attorney-client privilege and (2) likelihoods of unfavorable litigation outcomes that approach auditors' lower bound for accrual both may inhibit lawyers' responses to auditors. Overall, these findings raise doubts about the efficacy of this widely utilized auditing procedure and lead to concerns about whether litigation contingencies and corresponding losses may be underreported in financial statements.


Author(s):  
LJ. Tanovic ◽  
P. Bojanic ◽  
R. Puzovic ◽  
S. Klimenko

This paper offers an experimental study of the microcutting mechanisms in marble grinding to aid the optimization of the marble grinding process. The necessity for investigating these mechanisms is dictated by the increased use of marble in many applications and the fact that grinding and polishing processes are the dominant technologies used to meet surface finish requirements in this natural material. The experiments are aimed at the determination of the normal component of the cutting force and of the grain traces in microcutting with a single diamond grain. The investigations carried out make provisions for establishing critical grain penetration and cutting depths and allow the prediction of the normal cutting force component as a function of grain penetration speed and depth.


Author(s):  
Harish R ◽  
Ramesh S ◽  
Tharani A ◽  
Mageshkumar P

This paper presents the results of an experimental investigation of the compressive strength of concrete cubes containing termite mound soil. The specimens were cast using M20 grade of concrete. Two mix ratios for replacement of sand and cement are of 1:1.7:2.7 and 1:1.5:2.5 (cement: sand: aggregate) with water- cement ratio of 0.45 and varying combination of termite mound soil in equal amount ranging from 30% and 40% replacing fine aggregate (sand) and cement from 10%,15%,20% were used. A total of 27 cubes, 18 cylinders and 6 beams were cast by replacing fine aggregate, specimens were cured in water for 7,14 and 28 days. The test results showed that the compressive strength of the concrete cubes increases with age and decreases with increasing percentage replacement of cement and increases with increasing the replacement of sand with termite mound soil cured in water. The study concluded that termite mound cement concrete is adequate to use for construction purposes in natural environment.


2014 ◽  
Vol 606 ◽  
pp. 147-151 ◽  
Author(s):  
M.S. Somia Alfatih ◽  
M. Salman Leong ◽  
L.M. Hee

Bispectral analysis is one of the relatively more recent tools in signal processing used for detection and identification of higher harmonics in a signal. It is also acknowledged to be one of Higher Order Spectral Analysis (HOSA) effective tools for detecting nonlinear behavior in mechanical systems. In this study, vibration sources in a hydraulic machine which may have features of nonlinear behavior were investigated. An experimental study was undertaken to formulate a more sensitive and effective method using Bispectral analysis to diagnose cavitation in a centrifugal pump facility. Cavitation was induced on the suction side of the pump. The cavitation signal was analyzed with and without induced cavitation conditions at different locations on the pump, and analyzed using FFT and bispectrum methods. It was observed that bispectral analysis could be used as an early indicator of cavitation with changes for severity of cavitation.


2017 ◽  
Vol 38 (7) ◽  
pp. 955-958 ◽  
Author(s):  
Tuan-Khoa Nguyen ◽  
Hoang-Phuong Phan ◽  
Toan Dinh ◽  
Jisheng Han ◽  
Sima Dimitrijev ◽  
...  

Author(s):  
Svetlana Sineva ◽  
Jeff Chen ◽  
Taufiq Hidayat ◽  
Maksym Shevchenko ◽  
Peter C. Hayes ◽  
...  

Abstract Laboratory experimental study was undertaken to characterise the four-phase slag/matte/metal/tridymite equilibria of the Cu-Fe-O-S-Si system at 1473 K [1200°C], 1523 K [1250° C] and 1573 [1300°C] in a "closed" system without interaction with gas phase. The research methodology involved high temperature equilibration, ultra-fast quenching of the equilibrated samples followed by quantitative measurement of the equilibrated phases by electron probe X-ray microanalysis. Attainment of chemical equilibrium was carefully checked by the 4-points test approach. The results obtained in the present study provide reliable fundamental experimental information, which is crucial for the development and optimisation of the multicomponent thermodynamic database for copper-containing systems.


1995 ◽  
Vol 39 (01) ◽  
pp. 95-101
Author(s):  
Cherng-Yuan Lin ◽  
Chein-Ming Lin ◽  
Che-Shiung Cheng

An experimental investigation is presented of the influences of emulsification of marine fuel oils A and C with water on the micro-explosion phenomenon and combustion characteristics of a burning droplet. The amount of surfactant and water-to-oil ratio by volume in the emulsion are varied to observe the variations of ignition delay, flame length, time required to attain the maximum flame length, duration as well as intensity of micro-explosion, flame appearance, and overall burning time. The measurements show that the emulsification effects on the combustion of marine fuel oils A and C are different. A droplet of C-oil emulsion is shown to be influenced by the addition of water and surfactant more significantly. The micro-explosion phenomena of droplets of A-and C-oil emulsions are seen to occur after and before their ignition, respectively. In addition, separate combinations of water and surfactant content exist for these fuel oils to achieve better emulsification effects on combustion. Droplets of emulsions with W/O = 15/85, E% = 2% for fuel oil A and W/O = 25/75, E% = 1% for fuel oil C are found to have the most violent droplet-disruption phenomenon and the longest flame length.


1963 ◽  
Vol 18 (5) ◽  
pp. 1041-1042 ◽  
Author(s):  
Curt A. Wiederhielm

A system which permits continuous recording of dimensions of microscopic blood vessels is described. The system utilizes information contained in the video signal of a television microscope to develop an analog voltage proportional to the time required for the electron beam to sweep across the image of the blood vessel. This time interval is also proportional to the dimension of the vessel. Calibration of the system yielded a standard error of estimate of ±3.7 μ on a series of glass capillaries, ranging in size from 15 to 150 μ. The rise time of the system was in the order of 40 msec. Long- and short-term drift was less than 3 μ/hr. The system is used in an experimental study of viscoelastic properties of small arteries and arterioles. microcirculation; viscoelastic properties; frog mesentery Submitted on April 17, 1963


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