scholarly journals Existing Improvements in Simulation of Fire–Wind Interaction and Its Effects on Structures

Fire ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 27
Author(s):  
Maryam Ghodrat ◽  
Farshad Shakeriaski ◽  
David James Nelson ◽  
Albert Simeoni

This work provides a detailed overview of existing investigations into the fire–wind interaction phenomena. Specifically, it considers: the fanning effect of wind, wind direction and slope angle, and the impact of wind on fire modelling, and the relevant analysis (numerical and experimental) techniques are evaluated. Recently, the impact of fire on buildings has been widely analysed. Most studies paid attention to fire damage evaluation of structures as well as structure fire safety engineering, while the disturbance interactions that influence structures have been neglected in prior studies and must be analysed in greater detail. In this review article, evidence regarding the fire–wind interaction is discussed. The effect of a fire transitioning from a wildfire to a wildland–urban interface (WUI) is also investigated, with a focus on the impact of the resulting fire–wind phenomenon on high- and low-rise buildings.

Author(s):  
Ashish Kumar ◽  
Amar Partap Singh Pharwaha

Background: Patch antennas are composed of the substrate material with patch and ground plane on the both sides of the substrate. The dimensions and performance characteristics of the antenna are highly influenced by the choice of the appropriate substrate depending upon the value of their dielectric constant. Generally, low index substrate materials are used to design the patch antenna but there are also some of the applications, which require the implementation of patch antenna design on high index substrate like silicon and gallium arsenide. Objective: The objective of this article is to review the design of antennas developed on high index substrate and the problems associated with the use of these materials as substrate. Also, main challenges and solutions have been discussed to improve the performance characteristics while using the high index substrates. Method: The review article has divided into various sections including the solution of the problems associated with the high index substrates in the form of micro-machining process. Along with this, types of micro machining and their applications have discussed in detail. Results: This review article investigates the various patch antennas designed with micro-machining technology and also discusses the impact of micro-machining process on the performance parameters of the patch antennas designed on high index substrates. Conclusion: By using the micro-machining process, the performance of patch antenna improves drastically but fabrication and tolerances at such minute structures is very tedious task for the antenna designers.


2021 ◽  
Vol 26 (Sup4) ◽  
pp. S24-S29
Author(s):  
Claire Jeans ◽  
Bena Brown ◽  
Elizabeth C Ward ◽  
Anne E Vertigan

Lymphoedema is a disorder of the lymphatic system that presents as an atypical swelling and accumulation of protein-rich fluid within the interstitial spaces. Head and neck lymphoedema (HNL) is highly prevalent in patients who have been treated for head and neck cancer (HNC) and may manifest externally on the face and neck; internally within the oral cavity, pharynx or larynx; or as a combination of both. HNL is known to contribute to a wide range of physical, functional and psychological issues, and presents several unique challenges in terms of its management. This review article provides an overview of HNL for clinicians and aims to improve awareness of this condition and the impact it has on patients.


Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3009
Author(s):  
Andrius Grigas ◽  
Aurelija Kemzūraitė ◽  
Dainius Steponavičius ◽  
Aušra Steponavičienė ◽  
Rolandas Domeika

Application of hydroponic systems in feed production has not been extensively studied. Therefore, there is insufficient data on the effect of the slope of hydroponic growing trays used in the nutrient film technique on wheat fodder yield and its qualitative parameters. The slope of the trays has only been studied for food crops. This study conducted experimental research using a nutrient film technique hydroponic fodder growing device to evaluate the impact of growing tray slope angle on hydroponic wheat fodder production. The slope angle of the growing trays was changed from 2.0% (1.15°) to 8.0% (4.57°) with increments of 1.5% (0.86°). This research used two different light sources for wheat sprout illumination: indoor lighting (fluorescent lamps) and light-emitting diode illumination. In addition, two nutrient solutions were used for sprout irrigation: tap water and a solution enriched with macro- and microelements. Experimental studies confirmed the hypothesis that the slope angle of growing trays significantly affects the yield of wheat fodder grown for seven days. Analyzing the results, we found that the highest yield of wheat fodder after seven days of cultivation was achieved with growing trays sloped by 6.5% and using indoor lighting. In addition, we achieved the highest wheat fodder dry matter content using a 6.5% slope angle. Experimental studies also confirmed the hypothesis that using macro- and micronutrients in the nutrient solution does not significantly affect the yield of wheat fodder grown hydroponically for seven days.


Author(s):  
O. Maistrenko ◽  
O. Karavanov ◽  
A. Shcherba

It is established that the role of reconnaissance and fire systems in the implementation of enemy fire damage in military conflicts occurring at the beginning of the XXI century. Increased  to 75%. However, it was found that the effectiveness of these systems depends on the quality of their equipment. The main factors that are often not taken into account in the acquisition are the possibility, interoperability, stability of each element, the impact of elements on the stability of each other and the functioning of the RVS as a whole. The analysis of recent research and publications has shown that as of today, the approaches to determining the composition of reconnaissance fire systems taking into account these factors are not justified. Given the above, it was decided to conduct a structural and functional analysis of the reconnaissance fire system and the decomposition of its functions and subsystems. To this end, based on the method of cluster analysis, an algorithm for combining a set of tasks performed by reconnaissance and fire systems into groups has been developed and substantiated. The method of expert evaluation was used to obtain substantiated data on the implementation of such a merger. According to the proposed algorithm, the main tasks were first identified, which involve reconnaissance and fire systems. Subsequently, an expert group was formed and the coefficient of relative competence of each member of the expert group was determined. The experts were then asked to combine the identified tasks according to their characteristics into an arbitrary number of groups. After processing the opinions of experts, 10 characteristic groups were identified. Finally, the experts were asked to combine the obtained groups in such a way that each association consisted of similar objects and the objects of different associations differed significantly. The results of the work revealed the functional interconnectedness of the tasks, processes and subsystems of the reconnaissance and fire system. It is also established that a typical reconnaissance fire system will consist of three subsystems (control, reconnaissance and fire influence), which perform specific functions for each of them.


Author(s):  
Blanka Klimova ◽  
Marcel Pikhart

Facebook is undoubtedly the most popular social network site nowadays with over two billion users. Therefore, there has been research exploring its potential as a learning environment for various fields of education, including learning English as a foreign language (EFL). As the findings of research studies indicate, Facebook is especially used in developing productive language skills, such as writing, which is considered to be the least popular and the most difficult skill to master. Thus, the purpose of this article is to explore the impact of Facebook on developing writing skills in learning English as a foreign language. The methodology is based on the search for available studies on the research topic, i.e., the impact of Facebook on developing writing skills in EFL, in the world’s databases: Web of Science and Scopus. The search was not limited by any time period. The results of this review article reveal that using Facebook has a positive effect on developing writing skills in EFL classes, especially in shaping and organizing ideas, enhancing motivation, developing and supporting collaboration among peers, improving vocabulary, and reducing students’ shyness. However, more experimental research should be done in this area to reveal other aspects of the writing process, such as communicative language competence, which can be improved by using Facebook, as well as address researchers from continents other than Asia.


2015 ◽  
Vol 8 (3) ◽  
pp. 108-113 ◽  
Author(s):  
Benjamin O Black ◽  
Séverine Caluwaerts ◽  
Jay Achar

Ebola viral disease’s interaction with pregnancy is poorly understood and remains a particular challenge for medical and para-medical personnel responding to an outbreak. This review article is written with the benefit of hindsight and experience from the largest recorded Ebola outbreak in history. We have provided a broad overview of the issues that arise for pregnant women and for the professionals treating them during an Ebola outbreak. The discussion focuses on the specifics of Ebola infection in pregnancy and possible management strategies, including the delivery of an infected woman. We have also discussed the wider challenges posed to pregnant women and their carers during an epidemic, including the identification of suspected Ebola-infected pregnant women and the impact of the disease on pre-existing health services. This paper outlines current practices in the field, as well as highlighting the gaps in our knowledge and the paramount need to protect the health-care workers directly involved in the management of pregnant women.


2003 ◽  
Vol 40 (2) ◽  
pp. 186-189 ◽  
Author(s):  
N. Johnson ◽  
Jonathan R. Sandy

Objective The use of ultrasound for the prenatal diagnosis of cleft lip and palate has aided considerably in the early diagnosis of orofacial clefting. The impact and consequences of this need to be considered as the reliability and validity of ultrasound diagnosis increases. This review article considers a number of these issues as well as up-to-date information on the quality of the technique.


Author(s):  
Mohamed Gharib ◽  
Ali Tavakoli ◽  
Yildirim Hurmuzlu

This paper presents the solution of the impact problem for a sliding/bouncing baton on flat and inclined planes subject to surface friction. The baton is assumed to have unilaterally constrained motion, which means one end slides on the ground while the other end collides with the ground. We use the impulse momentum approach and incorporate the impulse correlation ratio (ICR) hypothesis to solve the ground impact problem when the system has unilaterally constrained dynamics. Parametric investigations were carried out to examine the effect of the baton’s length and the inclined wall slope angle on the impulse correlation ratio. Numerical simulation and experiments were carried out to validate the model.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Yangchun Han ◽  
Jiulong Cheng ◽  
Weifeng Zheng ◽  
Shijun Ding

In order to evaluate the uplift bearing capacity of belled piers beside slopes, a series of numerical simulations are carried out based on field tests data. First, a number of uplift loading tests of full-scale belled piers are carried out on the project site of transmission line in Anhui Province, China. Second, a slope-foundation model for numerical modeling is proposed and calibrated based on field tests data. The behavior of belled piers adjacent to slopes subject to uplift load is studied by numerical modeling. The impact of three parameters, including distance (a) from the belled pier to the crest of the slope, slope angle (β), and embedment depth (h) of the belled pier, has been investigated on the uplift capacity of the belled pier. Based on the simulation results, an attenuation coefficient (ω) is put forward for evaluating the reduction of uplift bearing capacity of the belled pier. The results show that the coefficient ω is negatively correlated with distance a and depth h, and the influence of distance a is greater than that of depth h according to the results of variance analysis, but the difference is not significant by F test. Moreover, the empirical equation between attenuation coefficient ω and three key factors a, β, and h had been presented by a series of fitting.


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