Studies on the impact of external fire on the lye of the shelter housing

2021 ◽  
Vol 109 (1) ◽  
pp. 11-16
Author(s):  
A. Baryłka
Keyword(s):  
Numerical Analysis ◽  
Second Stage ◽  
Heating And Cooling ◽  
Flow Through ◽  
Time Changes ◽  
Two Stages ◽  
The Impact ◽  
Fourier Equation ◽  
Practical Implications ◽  
Vast Area

Purpose: The presented article presents a numerical analysis carried out to determine the impact of an external fire taking place on the surface of the ground on the level of stress of the trench shelter casing protected by a layer of soil. Design/methodology/approach: Numerical analysis was carried out in two stages. In the first stage, a quasi-stationary distribution of the initial temperature in the centre of the ground and the shelter casing was sought. In the second stage of the analysis, the effect of the fire was considered according to the profile of time changes in the temperature of the shelter object. Findings: We assume that the trench shelter is in an oblong shape, and the fire extends over a vast area. The area surrounding the shelter casing was treated as a material with average constant thermodynamic values. Research limitations/implications: The process related to heating and cooling the enclosure was described on the basis of the Fourier equation on heat conduction in terms of the heterogeneous nature of the material, primer and concrete. Practical implications: The use of the trench shelter model as a research element in the design of special objects. Originality/value: The methods of non-stationary temperature flow through the ground and the shelter casing used, allows for a very realistic indication of how the housing will behave under the influence of high temperature caused by an external fire. The article can be useful for designers who design underground shelters.

scholarly journals STUDY OF THE EFFECT OF EXAMINATION STRESS ON THE INDICES OF THE MENTAL WORKING CAPACITY OF UNIVERSITY STUDENTS

2019 ◽  
Vol 98 (5) ◽  
pp. 527-533
Author(s):  
Ekaterina S. Grosheva ◽  
N. V. Sokolova ◽  
O. I. Gubina
Keyword(s):  
Correlation Analysis ◽  
Factor Model ◽  
Mental Performance ◽  
Low Level ◽  
Second Stage ◽  
Reactive Anxiety ◽  
Exam Stress ◽  
Group 2 ◽  
Two Stages ◽  
The Impact

Introduction. In this study, there were examined features of the impact of exam stress on mental performance and anxiety level in 2-3 year students of medical and pedagogical universities. Materials and methods. The levels of reactive and personal anxiety were studied according to the C. Spielberger anxiety scale adapted by Yu. L. Khanin, attention was assessed using the Pieron-Rüser test, the Bourdon-Anfimov correction test was used to study the level of mental performance, the type of temperament was determined using a two-factor model of extraversion and neuroticism using questionnaire H.J. Eysenck. The study was implemented in two stages: the first stage - during the semester period, and the second stage - during the examination session. For processing the data obtained during the study, a standard statistical software package was used, and correlation analysis was used to identify the relationships between the variables studied. Results. The assessment of situational anxiety in the second stage showed a statistically significant increase in the number of students with high and extremely high levels of anxiety in 24 and 3 respondents from the 1 group respectively (p ≤ 0.05), and 17 and 3 respondents in group 2, respectively (p ≤ 0.05). Correlation analysis of the relationship between reactive anxiety and mental performance showed a weak and medium correlation among students in both groups. The attention study in both groups showed that in the second stage of the study, the indices change: in 1 group, the proportion of students with a low level of attention increased to 40%, and in 2 the number of students with low and very low level of attention decreased by 2.77% and 11.08%, respectively (p ≤ 0.05). Conclusion. Increased study loads and requirements for students were proved to contribute to an increase in the level of reactive anxiety, in the period between sessions indices of mental performance in students decrease, respectively, and the level of attention declines.

Investigation of the Cost of Future Naval Amphibious Capability

2015 ◽  
Author(s):  
Andrew J. Jones ◽  
Rob Armstrong
Keyword(s):  
Task Group ◽  
Second Stage ◽  
The Creation ◽  
Two Stages ◽  
Vessel Impact ◽  
The Cost ◽  
The Impact

Through the creation of a large number of concept designs, the cost and vessel impact of deploying and supporting amphibious operations has been investigated. The investigation has looked at capabilities such as the transportation and delivery of vehicles, landing craft, aviation and embarked troops in a number of platform types such as LPDs, LHDs and Ro-Ros. A series of trends describing the costs of the capability have been investigated to estimate the cost of individual capabilities within a design. Over the timeframe of the study, vessel manning is predicted to change and a method of predicting the crew requirement has been developed to investigate the impact of reduced manning on amphibious platform designs. This is the first of two stages of work; in the second stage the requirements for a task group will be investigated to determine the best way to deploy capability at a fleet level.

Development of a Swirl Nozzle for Powder Technology

2013 ◽  
Author(s):  
Mehmet Alper Sofuoglu ◽  
Murat Erbas ◽  
Ibrahim Uslan ◽  
Atilla Biyikoglu
Keyword(s):  
Lower Cost ◽  
Nozzle Geometry ◽  
Design Parameters ◽  
Maximum Pressure ◽  
Pressure Data ◽  
Delivery Tube ◽  
Second Stage ◽  
Flow Through ◽  
Two Stages ◽  
Atomization Nozzle

In this study, a gas atomization nozzle for metal powder production has been designed and modeled numerically. The design has been performed in two stages. At the first stage of the design, the size and geometry of the nozzle have been developed to obtain circulated flow through the nozzle as a pre-design. At the second stage, a parametrical analysis has been done using a CFD code. The geometry of the nozzle has been changed and the effect of geometric parameters was determined to find out the more efficient nozzle design parameters. Gas behavior at the nozzle exit and effect of the gas on the melt delivery tube tip has been investigated. Appropriate values for the investigated parameters have been determined to get maximum pressure in vacuum condition at the tip of the melt. The pressure observed at the melt delivery tube was compared with the experimental melt tip pressure data. These results suggest that the CFD solutions can be used in the design of the nozzle. Thus, the lower cost and shorter time would be possible to develop highly efficient nozzle geometry.

scholarly journals Solidification Mechanism of the D-Gun Sprayed Fe-Al Particles

2017 ◽  
Vol 62 (4) ◽  
pp. 2391-2397
Author(s):  
W. Wołczyński ◽  
C. Senderowski ◽  
B. Fikus ◽  
A.J. Panas
Keyword(s):  
Centrifugal Force ◽  
Water Surface ◽  
Solid Shell ◽  
Liquid Droplets ◽  
Liquid Particle ◽  
Second Stage ◽  
Two Stages ◽  
Solidification Mechanism ◽  
The Impact ◽  
Spraying Method

AbstractThe detonation gas spraying method is used to study solidification of the Fe-40Al particles after the D-gun spraying and settled on the water surface. The solidification is divided into two stages. First, the particle solid shell forms during the particle contact with the surrounding air / gas. Usually, the remaining liquid particle core is dispersed into many droplets of different diameter. A single Fe-Al particle is described as a body subjected to a rotation and finally to a centrifugal force leading to segregation of iron and aluminum. The mentioned liquid droplets are treated as some spheres rotated freely / chaotically inside the solid shell of the particle and also are subjected to the centrifugal force. The centrifugal force, and first of all, the impact of the particles onto the water surface promote a tendency for making punctures in the particles shell. The droplets try to desert / abandon the mother-particles through these punctures. Some experimental evidences for this phenomenon are delivered. It is concluded that the intensity of the mentioned phenomenon depends on a given droplet momentum. The droplets solidify rapidly during their settlement onto the water surface at the second stage of the process under consideration. A model for the solidification mechanism is delivered.

scholarly journals Optimal Facility Location Model Based on Genetic Simulated Annealing Algorithm for Siting Urban Refueling Stations

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Dawei Chen ◽  
Shun Zhou ◽  
Yuanchang Xie ◽  
Xuhong Li
Keyword(s):  
Simulated Annealing ◽  
Simulated Annealing Algorithm ◽  
Impact Factors ◽  
Location Decisions ◽  
Second Stage ◽  
Genetic Simulated Annealing Algorithm ◽  
Annealing Algorithm ◽  
Two Stages ◽  
Station Location ◽  
The Impact

This paper analyzes the impact factors and principles of siting urban refueling stations and proposes a three-stage method. The main objective of the method is to minimize refueling vehicles’ detour time. The first stage aims at identifying the most frequently traveled road segments for siting refueling stations. The second stage focuses on adding additional refueling stations to serve vehicles whose demands are not directly satisfied by the refueling stations identified in the first stage. The last stage further adjusts and optimizes the refueling station plan generated by the first two stages. A genetic simulated annealing algorithm is proposed to solve the optimization problem in the second stage and the results are compared to those from the genetic algorithm. A case study is also conducted to demonstrate the effectiveness of the proposed method and algorithm. The results indicate the proposed method can provide practical and effective solutions that help planners and government agencies make informed refueling station location decisions.

scholarly journals Assessment of telephone speech perception in individuals who received cochlear implant in the period 1993-2003

CoDAS ◽  
2013 ◽  
Vol 25 (5) ◽  
pp. 400-406 ◽  
Author(s):  
Pricila Perini Rigotti ◽  
Orozimbo Alves Costa ◽  
Maria Cecilia Bevilacqua ◽  
Leandra Tabanez do Nascimento ◽  
Katia de Freitas Alvarenga
Keyword(s):  
Speech Perception ◽  
Cochlear Implant ◽  
Cell Phone ◽  
Rehabilitation Program ◽  
Second Stage ◽  
Auditory Rehabilitation ◽  
Satisfactory Performance ◽  
Telephone Speech ◽  
Two Stages ◽  
The Impact

OBJECTIVE: To evaluate telephone speech perception in individuals who received cochlear implant in the period 1993-2003. METHODS: Twenty seven CI users were divided into pre and post-lingual groups, being the speech perception assessed in two stages: first by a list of sentences imposed on speakerphone with the same mapping used to evaluate the phone and, in a second stage, using the landline, landline phone adapter with CI and cell phone. RESULTS: In the group of pre-lingual hearing loss, 75% of subjects were able to maintain a dialogue with the interlocutor and 19% did so with difficulty. In the post-lingual group, 89% were able to maintain the dialogue with the interlocutor and 11% did so with difficulty. Both groups of subjects pre and post-lingual use the phone as a media, and most have satisfactory performance without the need for aid or CI accessories. CONCLUSION: One of the benefits of the CI is to introduce the life of the hearing impaired phone use regardless of their technology and accessories, as well as with the phone adapter and cell phone. In this study, most individuals CI users showed satisfactory performance in the comprehension of sentence and questions by the telephone, with better performance, although discrete, for the group post-lingual. Thus, there is the importance of careful indication of the IC and auditory rehabilitation program that minimize the impact of deafness in the communication, especially via telephone, regardless of the time when the hearing was acquired. So, this fact improves the conditions for CI users to maintain their daily activities, following the dynamism of contemporary life.

Imaging network design to improve the automated construction progress monitoring process

2019 ◽  
Vol 19 (3) ◽  
pp. 386-404
Author(s):  
Hadi Mahami ◽  
Farnad Nasirzadeh ◽  
Ali Hosseininaveh Ahmadabadian ◽  
Farid Esmaeili ◽  
Saeid Nahavandi
Keyword(s):  
Network Design ◽  
Progress Monitoring ◽  
Cloud Model ◽  
Content Type ◽  
Second Stage ◽  
Monitoring Process ◽  
Close Range ◽  
Two Stages ◽  
Construction Progress Monitoring ◽  
Practical Implications

Purpose This paper aims to propose an automatic imaging network design to improve the efficiency and accuracy of automated construction progress monitoring. The proposed method will address two shortcomings of the previous studies, including the large number of captured images required and the incompleteness and inaccuracy of generated as-built models. Design/methodology/approach Using the proposed method, the number of required images is minimized in two stages. In the first stage, the manual photogrammetric network design is used to decrease the number of camera stations considering proper constraints. Then the image acquisition is done and the captured images are used to generate 3D points cloud model. In the second stage, a new software for automatic imaging network design is developed and used to cluster and select the optimal images automatically, using the existing dense points cloud model generated before, and the final optimum camera stations are determined. Therefore, the automated progress monitoring can be done by imaging at the selected camera stations to produce periodic progress reports. Findings The achieved results show that using the proposed manual and automatic imaging network design methods, the number of required images is decreased by 65 and 75 per cent, respectively. Moreover, the accuracy and completeness of points cloud reconstruction is improved and the quantity of performed work is determined with the accuracy, which is close to 100 per cent. Practical implications It is believed that the proposed method may present a novel and robust tool for automated progress monitoring using unmanned aerial vehicles and based on photogrammetry and computer vision techniques. Using the proposed method, the number of required images is minimized, and the accuracy and completeness of points cloud reconstruction is improved. Originality/value To generate the points cloud reconstruction based on close-range photogrammetry principles, more than hundreds of images must be captured and processed, which is time-consuming and labor-intensive. There has been no previous study to reduce the large number of required captured images. Moreover, lack of images in some areas leads to an incomplete or inaccurate model. This research resolves the mentioned shortcomings.

SMS spam filtering and thread identification using bi-level text classification and clustering techniques

2016 ◽  
Vol 43 (1) ◽  
pp. 75-87 ◽  
Author(s):  
Naresh Kumar Nagwani ◽  
Aakanksha Sharaff
Keyword(s):  
State Of The Art ◽  
Binary Classification ◽  
Spam Detection ◽  
Spam Filtering ◽  
Clustering Techniques ◽  
Second Stage ◽  
Classification Technique ◽  
Two Stages ◽  
The Impact ◽  
Non Negative Matrix Factorization

SMS spam detection is an important task where spam SMS messages are identified and filtered. As greater numbers of SMS messages are communicated every day, it is very difficult for a user to remember and correlate the newer SMS messages received in context to previously received SMS. SMS threads provide a solution to this problem. In this work the problem of SMS spam detection and thread identification is discussed and a state of the art clustering-based algorithm is presented. The work is planned in two stages. In the first stage the binary classification technique is applied to categorize SMS messages into two categories namely, spam and non-spam SMS; then, in the second stage, SMS clusters are created for non-spam SMS messages using non-negative matrix factorization and K-means clustering techniques. A threading-based similarity feature, that is, time between consecutive communications, is described for the identification of SMS threads, and the impact of the time threshold in thread identification is also analysed experimentally. Performance parameters like accuracy, precision, recall and F-measure are also evaluated. The SMS threads identified in this proposed work can be used in applications like SMS thread summarization, SMS folder classification and other SMS management-related tasks.

Selection of the optimum tooth profile for plastic cycloidal gears

2014 ◽  
Vol 228 (18) ◽  
pp. 3395-3404 ◽  
Author(s):  
Krzysztof Biernacki
Keyword(s):  
Numerical Analysis ◽  
Gear Tooth ◽  
Strain Analysis ◽  
Tooth Profile ◽  
Correction Coefficient ◽  
Second Stage ◽  
Geometrical Characteristics ◽  
Stress And Deformation ◽  
Two Stages ◽  
Selection Of

Cycloidal gears make up the main working unit of hydraulic gerotor machines. In the article, a question of a more efficient application of plastics in building the gears is discussed. The discussion is based on a numerical strain analysis which was done by means of the finite elements method. The stress and deformation values in the operating cycloidal gears were specified. The numerical analysis was carried out in two stages in order to determine the optimum gear tooth profile. The profile depends on the tooth height and on the tooth correction coefficient. At the first stage, the optimum tooth height coefficient λ was calculated. Having determined the optimum value λ, the analysis was continued, and at the second stage, the optimum correction coefficient v for the gears at an earlier selected constant value λ was defined. The analysis results were useful in selecting parameters for determining the geometrical characteristics of the cycloidal gears. The parameters were then used in defining the most suitable tooth profile for the hydraulic machine featuring the cycloidal gears.

scholarly journals Policies for Improving PM2.5 Particles and GHGs Emissions in a Maritime Port of Taiwan: Evidence Based on the INDC and GGRMA Regulations

2021 ◽  
Vol 9 (12) ◽  
pp. 1315
Author(s):  
Ching-Chih Chang ◽  
Yi-An Tsai
Keyword(s):  
Pollution Reduction ◽  
Evidence Based ◽  
Second Stage ◽  
Reduce Emissions ◽  
Set Up ◽  
Liquid Natural Gas ◽  
Two Stages ◽  
The Impact ◽  
Policy Proposals ◽  
Port Of Kaohsiung

The impact of possible emission reduction policies designed to reduce port emissions in the Port of Kaohsiung in Taiwan was analyzed, focusing on ways to reduce air pollution from CO2, CH4, N2O, PM10, PM2.5, NOx, and SOx generated by vessels, cranes, and truck tractors in the port. This paper was set up in two stages to determine how pollution reduction policies could reach the 2030 and in 2050 goals. The results showed that emissions of CO2, CH4, N2O, PM10, PM2.5, NOx, and SOx could be reduced by 46%, 26%, 25%, 77%, 77%, 76%, and 68%, respectively, in the first stage (in 2030, INDC), and by 57%, 59%, 53%, 79%, 79%, 80%, and 69%, respectively, in the second stage (in 2050, GGGRMA), as compared to 2005 data. This paper concludes as follows: (1) for vessels, the use of liquid natural gas is the best way to reduce GHGs when navigating by water; (2) for bridge cranes, electrification is the better policy during operation; (3) in the case of truck tractors, the generation of battery-electric power is the best way to reduce emissions. These policy proposals for improving air quality can be applied to all ports in Taiwan.

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