scholarly journals Numerical Study on Air Egress Velocity of Ancillary Room Pressurization Systems in Apartment Fires

2020 ◽  
Vol 34 (4) ◽  
pp. 78-86
Author(s):  
Byeongjun Kim ◽  
Ying Yan ◽  
Weon Gyu Shin
Keyword(s):  
Flow Rate ◽  
Fire Safety ◽  
Numerical Study ◽  
Soot Concentration ◽  
Apartment House ◽  
Safety Standards ◽  
Air Supply ◽  
High Level ◽  
The Relationship ◽  
Fire Door

In this study, numerical simulations were performed on the air egress velocity of pressurization systems in an ancillary room when a fire occurred in an apartment house. The relationship between the air supply flow rate of a damper and air egress velocity at a fire door is predicted to be linear. Additionally, a minimum flow rate of the damper, which meets national fire safety standards for air egress velocity, i.e., 0.7 m/s can be estimated. Air egress velocity at the fire door is analyzed according to the supply air direction and installation height of the damper. When the damper has an upward supply air direction and is installed at a high level, the egress velocity at the top section of the fire door is larger, whereas the soot concentration at the ancillary room is lower than when the supply direction of the damper is downward. Therefore, it is found that increasing the air egress velocity at the top section of the fire door helps to efficiently prevent the inflow of smoke.

Academic motivation and professional skills development in the Specialty of Social Sciences and Tourism at a public university [Motivación académica y desarrollo de competencias profesionales en la Especialidad de Ciencias Sociales y Turismo de una universidad pública]

2019 ◽  
Vol 1 (2) ◽  
pp. 96
Author(s):  
Ana Cecilia De Paz Lazaro ◽  
Jessica Luz Palomino Collantes
Keyword(s):  
Social Sciences ◽  
Academic Motivation ◽  
Public University ◽  
Skills Development ◽  
Professional Skills ◽  
Research Results ◽  
Competencias Profesionales ◽  
High Level ◽  
The Relationship

The objective of the research is to determine the relationship between academic motivation and the professional skills development in the specialty of Social Sciences and Tourism. The study is quantitative and the design is non-experimental correlational translational. The results indicate that there is a high level relationship (0.914) between the independent academic motivation variable and the professional competences development in the Specialty of Social Sciences and Tourism. In conclusion, motivation is directly related to the professional skills development in the specialty of Social Sciences and Tourism. The research results conclude that there is a high relationship between the variables.

Barriers of physical activity (kinesiophobia) in patients subjected to cardiac rehabilitation

2014 ◽  
Vol 6 (4) ◽  
Author(s):  
Janusz Kocjan ◽  
Andrzej Knapik
Keyword(s):  
Physical Activity ◽  
Cardiac Rehabilitation ◽  
Short Form ◽  
Social Activity ◽  
Self Assessment ◽  
Rehabilitation Process ◽  
Sf 36 ◽  
Polish Version ◽  
High Level ◽  
The Relationship

AbstractBackground: Comprehensive cardiac rehabilitation (CR) is a process designed to restore full physical, psychological and social activity and to reduce cardiovascular risk factors. Fear of movement may contribute to the occurrence and intensification of hypokinesia, and consequently affect the effectiveness of therapy. The aim of the study was to determine the level of barriers of physical activity in patients undergoing cardiac rehabilitation. The relationship between selected determinants (age and health selfassessment) and the kinesiophobia level were also examined.Material/Methods: 115 people aged 40-84 years were examined: 50 females (x = 63.46; SD = 11.19) and 65 males (x = 64.65; SD = 10.59) - patients undergoing cardiac rehabilitation at the Upper-Silesian Medical Centre in Katowice. In the present study, the Polish version of questionnaires: Kinesiophobia Causes Scale (KCS) and Short Form Health Survey (SF-36) were used. Questionnaires were supplemented by authors’ short survey.Results: The patients presented an elevated level of kinesiophobia, both in general as well as in individual components. In women, the kinesiophobia level was higher than in men. The psychological domain was a greater barrier of physical activity than the biological one. Strong, negative correlations of psychological and biological domains of kinesiophobia to physical functioning (SF-36) were noted in women. In the case of men, correlations were weaker, but also statistically significant.Conclusions: 1. Sex differentiates patients in their kinesiophobia level 2. Poor self-assessment of health is associated with a greater intensification of kinesiophobia 3. A high level of kinesiophobia may negatively affect cardiac rehabilitation process

Investigation of Online Learning Satisfaction During COVID 19: In Relation to Academic Achievement

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Abdul Basith ◽  
Rosmaiyadi Rosmaiyadi ◽  
Susan Neni Triani ◽  
Fitri Fitri
Keyword(s):  
Academic Achievement ◽  
Online Learning ◽  
Random Sampling ◽  
Sampling Technique ◽  
Simple Random Sampling ◽  
Research Data ◽  
Student Academic Achievement ◽  
Learning Satisfaction ◽  
High Level ◽  
The Relationship

The aim of this research is; 1) investigating the level of online learning satisfaction among students during COVID 19; 2) analyzing the influence of differences in gender, years of study, major in determining online learning satisfaction among students during COVID 19; 3) to analyze the relationship between online learning satisfaction and student academic achievement during COVID 19. The population was 656 students at STKIP Singkawang, and then a sample of 357 students (87 males and 270 females) was taken using a simple random sampling technique. The instrument in this study was adapted from Aman's Satisfaction instrument, which was then used to collect research data. Data analysis using SPSS with descriptive statistical techniques, MANOVA, and correlation. The results showed that online learning satisfaction was at a high level, meaning that students were satisfied with the online learning that had been implemented. The major differences have a significant effect on determining online learning satisfaction. Intercorrelation shows that there is a significant relationship on each indicator of online learning satisfaction with academic achievement, meaning that the higher the satisfaction felt by students in online learning, the student's academic achievement will increase.

CHALLENGES OF INTERPRETATION OF GENETIC TEST RESULTS ON THE EXAMPLE OF STUDY OF ENDURANCE

2020 ◽  
Vol 8 (1) ◽  
pp. 75-82
Author(s):  
Elmira Shamsuvaleeva ◽  
Anastasiya Nevmyvaka ◽  
Andrey Nazarenko
Keyword(s):  
Sport Activity ◽  
Computerized Testing ◽  
Daily Routine ◽  
Modern Approach ◽  
Functional Studies ◽  
Sport Training ◽  
Genetic Test Results ◽  
High Level ◽  
Biomedical Education ◽  
The Relationship

The purpose of the research is to study the possibility of predicting the development of aerobic endurance of athletes through a comparative analysis of the outcomes of genetic and computerized testing. Methods and organization of the research. In our research, we used scientific and methodological literature, as well as the outcomes of competitive activity and genetic analysis of a particular athlete. The total number of survey respondents was 158 people including athletes (n = 85) and coaches (n = 73). Results and discussion. Some authors find the relationship between the ability to develop and manifest endurance and the presence of the appropriate alleles of genes: ACE I, ACNT X, ACNT3 (RX, XX), ADRA2A, AMPDI C, PGC1A Gly, NFATC4, UCP2. Most studies reveal the relationship between the ACE gene and endurance supported by the I allele. Genetic foresight of the possibility of developing aerobic endurance of athletes can become the framework for the application of an individual approach in sport training, and contribute to the development of techniques aimed at the refinement of physical qualities. The modern approach to the coaching and competitive activities of athletes should include both genetic and functional studies of the human body. Conclusion. Sport forecast cannot be based solely on genetic testing results. The presence of polymorphisms in one or more genes associated with sport activity is the platform for good performance in a particular sport, but the actual manifestation of genetic predisposition depends on many factors. These factors include nutrition, daily routine and competent organization of the training process, which requires a high level of theoretical and practical competency of coaches in the field of biomedical education.

scholarly journals A Numerical Study of Sub-Millisecond Integrated Mix-and-Inject Microfluidic Devices for Sample Delivery at Synchrotron and XFELs

2021 ◽  
Vol 11 (8) ◽  
pp. 3404
Author(s):  
Majid Hejazian ◽  
Eugeniu Balaur ◽  
Brian Abbey
Keyword(s):  
Molecular Dynamics ◽  
Flow Rate ◽  
Numerical Study ◽  
Three Dimensional ◽  
Microfluidic Devices ◽  
Liquid Jets ◽  
Mixing Efficiency ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
Time Required

Microfluidic devices which integrate both rapid mixing and liquid jetting for sample delivery are an emerging solution for studying molecular dynamics via X-ray diffraction. Here we use finite element modelling to investigate the efficiency and time-resolution achievable using microfluidic mixers within the parameter range required for producing stable liquid jets. Three-dimensional simulations, validated by experimental data, are used to determine the velocity and concentration distribution within these devices. The results show that by adopting a serpentine geometry, it is possible to induce chaotic mixing, which effectively reduces the time required to achieve a homogeneous mixture for sample delivery. Further, we investigate the effect of flow rate and the mixer microchannel size on the mixing efficiency and minimum time required for complete mixing of the two solutions whilst maintaining a stable jet. In general, we find that the smaller the cross-sectional area of the mixer microchannel, the shorter the time needed to achieve homogeneous mixing for a given flow rate. The results of these simulations will form the basis for optimised designs enabling the study of molecular dynamics occurring on millisecond timescales using integrated mix-and-inject microfluidic devices.

scholarly journals Model of thermal buoyancy in cavity-ventilated roof constructions

2021 ◽  
pp. 174425912098418
Author(s):  
Toivo Säwén ◽  
Martina Stockhaus ◽  
Carl-Eric Hagentoft ◽  
Nora Schjøth Bunkholt ◽  
Paula Wahlgren
Keyword(s):  
Analytical Model ◽  
Flow Rate ◽  
Numerical Study ◽  
Air Flow ◽  
Wind Pressure ◽  
Air Flow Rate ◽  
Test Set ◽  
Air Cavity ◽  
Thermal Buoyancy ◽  
The Impact

Timber roof constructions are commonly ventilated through an air cavity beneath the roof sheathing in order to remove heat and moisture from the construction. The driving forces for this ventilation are wind pressure and thermal buoyancy. The wind driven ventilation has been studied extensively, while models for predicting buoyant flow are less developed. In the present study, a novel analytical model is presented to predict the air flow caused by thermal buoyancy in a ventilated roof construction. The model provides means to calculate the cavity Rayleigh number for the roof construction, which is then correlated with the air flow rate. The model predictions are compared to the results of an experimental and a numerical study examining the effect of different cavity designs and inclinations on the air flow rate in a ventilated roof subjected to varying heat loads. Over 80 different test set-ups, the analytical model was found to replicate both experimental and numerical results within an acceptable margin. The effect of an increased total roof height, air cavity height and solar heat load for a given construction is an increased air flow rate through the air cavity. On average, the analytical model predicts a 3% higher air flow rate than found in the numerical study, and a 20% lower air flow rate than found in the experimental study, for comparable test set-ups. The model provided can be used to predict the air flow rate in cavities of varying design, and to quantify the impact of suggested roof design changes. The result can be used as a basis for estimating the moisture safety of a roof construction.

scholarly journals Integrated Magnetohydrodynamic Pump with Magnetic Composite Substrate and Laser-Induced Graphene Electrodes

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1113
Author(s):  
Mohammed Asadullah Khan ◽  
Jürgen Kosel
Keyword(s):  
Magnetic Flux ◽  
Flow Rate ◽  
Magnetic Composite ◽  
Propulsive Force ◽  
Closed Channel ◽  
Lab On Chip ◽  
Composite Substrate ◽  
On Chip ◽  
High Level ◽  
Moving Parts

An integrated polymer-based magnetohydrodynamic (MHD) pump that can actuate saline fluids in closed-channel devices is presented. MHD pumps are attractive for lab-on-chip applications, due to their ability to provide high propulsive force without any moving parts. Unlike other MHD devices, a high level of integration is demonstrated by incorporating both laser-induced graphene (LIG) electrodes as well as a NdFeB magnetic-flux source in the NdFeB-polydimethylsiloxane permanent magnetic composite substrate. The effects of transferring the LIG film from polyimide to the magnetic composite substrate were studied. Operation of the integrated magneto hydrodynamic pump without disruptive bubbles was achieved. In the studied case, the pump produces a flow rate of 28.1 µL/min. while consuming ~1 mW power.

scholarly journals Dynamics of Single Droplet Splashing on Liquid Film by Coupling FVM with VOF

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 841
Author(s):  
Yuzhen Jin ◽  
Huang Zhou ◽  
Linhang Zhu ◽  
Zeqing Li
Keyword(s):  
Liquid Film ◽  
Weber Number ◽  
Stokes Equations ◽  
Numerical Study ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Single Droplet ◽  
Navier Stokes Equations ◽  
Volume Method ◽  
The Relationship

A three-dimensional numerical study of a single droplet splashing vertically on a liquid film is presented. The numerical method is based on the finite volume method (FVM) of Navier–Stokes equations coupled with the volume of fluid (VOF) method, and the adaptive local mesh refinement technology is adopted. It enables the liquid–gas interface to be tracked more accurately, and to be less computationally expensive. The relationship between the diameter of the free rim, the height of the crown with different numbers of collision Weber, and the thickness of the liquid film is explored. The results indicate that the crown height increases as the Weber number increases, and the diameter of the crown rim is inversely proportional to the collision Weber number. It can also be concluded that the dimensionless height of the crown decreases with the increase in the thickness of the dimensionless liquid film, which has little effect on the diameter of the crown rim during its growth.

scholarly journals The relationship between time to a high COVID-19 response level and timing of peak daily incidence: an analysis of governments’ Stringency Index from 148 countries

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Yan Ma ◽  
Shiva Raj Mishra ◽  
Xi-Kun Han ◽  
Dong-Shan Zhu
Keyword(s):  
Standard Error ◽  
Daily Basis ◽  
Linear Regression Models ◽  
Response Level ◽  
Peak Number ◽  
Epidemic Curve ◽  
Government Response ◽  
Early Arrival ◽  
High Level ◽  
The Relationship

Abstract Background The transmission dynamics and severity of coronavirus disease 2019 (COVID-19) pandemic is different across countries or regions. Differences in governments’ policy responses may explain some of these differences. We aimed to compare worldwide government responses to the spread of COVID-19, to examine the relationship between response level, response timing and the epidemic trajectory. Methods Free publicly-accessible data collected by the Coronavirus Government Response Tracker (OxCGRT) were used. Nine sub-indicators reflecting government response from 148 countries were collected systematically from January 1 to May 1, 2020. The sub-indicators were scored and were aggregated into a common Stringency Index (SI, a value between 0 and 100) that reflects the overall stringency of the government’s response in a daily basis. Group-based trajectory modelling method was used to identify trajectories of SI. Multivariable linear regression models were used to analyse the association between time to reach a high-level SI and time to the peak number of daily new cases. Results Our results identified four trajectories of response in the spread of COVID-19 based on when the response was initiated: before January 13, from January 13 to February 12, from February 12 to March 11, and the last stage—from March 11 (the day WHO declared a pandemic of COVID-19) on going. Governments’ responses were upgraded with further spread of COVID-19 but varied substantially across countries. After the adjustment of SI level, geographical region and initiation stages, each day earlier to a high SI level (SI > 80) from the start of response was associated with 0.44 (standard error: 0.08, P < 0.001, R2 = 0.65) days earlier to the peak number of daily new case. Also, each day earlier to a high SI level from the date of first reported case was associated with 0.65 (standard error: 0.08, P < 0.001, R2 = 0.42) days earlier to the peak number of daily new case. Conclusions Early start of a high-level response to COVID-19 is associated with early arrival of the peak number of daily new cases. This may help to reduce the delays in flattening the epidemic curve to the low spread level. Graphic abstract

scholarly journals Report on the 18th International Symposium on Geo-disaster Reduction and the 4th Gu Dezhen Lecture, 20–22 November 2020, Beijing, China

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Shengwen Qi ◽  
Ning Liang ◽  
Kongming Yan ◽  
Zili Dai ◽  
Fawu Wang
Keyword(s):  
International Symposium ◽  
Disaster Reduction ◽  
High Level ◽  
The Relationship ◽  
Beijing China

AbstractThe 18th International Symposium on Geo-disaster Reduction (ISGdR) was held on 20–22 November in Beijing, China, focusing on the theme of “Improving the Relationship between Geoenvironment and Society”. In this symposium, a high-level Gu Dezhen Lecture and a number of keynote and invited lectures provided a platform for scientists, industrial professionals and students to share their researches and exchange novel ideas on geo-disaster reduction in a hybrid way of offline and online.

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