scholarly journals Experimental Investigation of the Effect of Heat Flux on the Fire Behavior of Engineered Wood Samples

Fire ◽  
2020 ◽  
Vol 3 (4) ◽  
pp. 61
Author(s):  
Denis Kasymov ◽  
Mikhail Agafontsev ◽  
Vladislav Perminov ◽  
Pavel Martynov ◽  
Vladimir Reyno ◽  
...  

This paper presents the experimental study results on the effect of heat flux emitted by a standard source on the charring and ignition characteristics of wood construction materials (plywood, chipboard, and oriented strand board) using infrared thermography (IRT) in the narrow spectral ranges of infrared wavelength. The time to ignition (TTI), charring rate and depth were obtained for the samples. In addition, the effect of several fire retardants on the charring rate and depth of the samples and TTI was analyzed. All fire retardants contribute to an increase in TTI, which confirms their main function—fire protection. However, the effect of fire retardants differs noticeably depending on the material. A new experimental technique is suggested, with the infrared imaging of the temperature distribution along the end of a sample under the heat flux effect on its frontal surface. The uniqueness of this approach consists in the registration of the entire process of ignition and combustion of the presented materials, which occurs in real time without contact with high spatial and temporal resolution. Using the infrared camera of the research class, it becomes possible to record the entire process from the occurrence of the temperature exposure region to the deep carbonized crater in the body of the material. The results can serve as additional recommendations in the development of fire hazard testing methods for construction materials and fire retardants.

2020 ◽  
Vol 99 (4) ◽  
pp. 379-383
Author(s):  
Vasily N. Afonyushkin ◽  
N. A. Donchenko ◽  
Ju. N. Kozlova ◽  
N. A. Davidova ◽  
V. Yu. Koptev ◽  
...  

Pseudomonas aeruginosa is a widely represented species of bacteria possessing of a pathogenic potential. This infectious agent is causing wound infections, fibrotic cystitis, fibrosing pneumonia, bacterial sepsis, etc. The microorganism is highly resistant to antiseptics, disinfectants, immune system responses of the body. The responses of a quorum sense of this kind of bacteria ensure the inclusion of many pathogenicity factors. The analysis of the scientific literature made it possible to formulate four questions concerning the role of biofilms for the adaptation of P. aeruginosa to adverse environmental factors: Is another person appears to be predominantly of a source an etiological agent or the source of P. aeruginosa infection in the environment? Does the formation of biofilms influence on the antibiotic resistance? How the antagonistic activity of microorganisms is realized in biofilm form? What is the main function of biofilms in the functioning of bacteria? A hypothesis has been put forward the effect of biofilms on the increase of antibiotic resistance of bacteria and, in particular, P. aeruginosa to be secondary in charcter. It is more likely a biofilmboth to fulfill the function of storing nutrients and provide topical competition in the face of food scarcity. In connection with the incompatibility of the molecular radii of most antibiotics and pores in biofilm, biofilm is doubtful to be capable of performing a barrier function for protecting against antibiotics. However, with respect to antibodies and immunocompetent cells, the barrier function is beyond doubt. The biofilm is more likely to fulfill the function of storing nutrients and providing topical competition in conditions of scarcity of food resources.


Author(s):  
А.С. Казицкая ◽  
Т.К. Ядыкина ◽  
М.С. Бугаева ◽  
А.Г. Жукова ◽  
Н.Н. Михайлова ◽  
...  

В условиях непрерывного воздействия неблагоприятных факторов окружающей и производственной среды на человека особую актуальность приобретает изучение механизмов, поддерживающих гомеостаз организма. Длительное поступление фторидов в организм приводит к формированию хронической фтористой интоксикации, патогенез которой вызывает многочисленные споры и дискуссии. До сих пор недостаточно внимания уделяется изучению висцеральной патологии, обусловленной нарушениями иммунного статуса в условиях воздействия на организм соединений фтора. Практически отсутствуют исследования по изучению иммунной реактивности, определяющей морфофункциональный характер ответной реакции печени на ранних стадиях развития фтористой интоксикации. Цель работы - изучение действий патофизиологических механизмов иммунной реактивности печени при субхроническом действии на организм соединений фтора. Методика. Опыты проведены на 210 лабораторных крысах-самцах массой 180-220 г., разделенных на 2 группы: контрольную (n=80) и группу животных с субхроническим действием фторида натрия (n=130). Экспериментальные животные в течение 12 нед имели свободный доступ к водному раствору фторида натрия (концентрация 10 мг/л, что составляет суточную дозу фтора 1,2 мг/кг массы тела). Для изучения иммунологических и биохимических показателей забирали кровь из хвостовой вены через 1, 3, 6, 9, 12 нед от начала эксперимента. Для оценки состояния гуморального звена иммунитета определяли уровень сывороточных иммуноглобулинов (IgA, IgG, IgM) иммуноферментным анализом с помощью наборов реактивов ЗАО «Вектор-Бест» (Новосибирск). Уровень сывороточных цитокинов: TNF-α, IL-1β, 2, 4, 6, 10 определяли на анализаторе Multiskan EX методом иммуноферментного анализа с использованием наборов «Вектор Бест» (Новосибирск). Подсчет общего количества лейкоцитов произведен классическим способом в камере Горяева, анализ лейкоцитарной формулы - в окрашенных мазках периферической крови. Метаболические изменения оценивали по активности ферментов в ткани печени: щелочной фосфатазы (ЩФ), аланин- и аспартатаминотрансфераз (АЛТ, АСТ), лактатдегидрогеназы (ЛДГ), гаммаглутамилтранспептидазы (γ-ГТ). Активность ферментов определяли унифицированными методами с помощью наборов реактивов ЗАО «Вектор-Бест» (Новосибирск) на фотометре PM-750 (Германия). Гистологические исследования печени осуществляли после декапитации крыс, проводимой под эфирным наркозом. Результаты. Показано, что субхроническое воздействие фторида натрия сопровождается формированием внутриклеточных и внутрисосудистых повреждений печени. Активация медиаторов воспаления и развитие иммунологических нарушений в динамике эксперимента способствуют формированию системной воспалительной реакции, которая приводит к появлению стойких морфологических нарушений в печени и изменению активности ферментов основных метаболических путей. Заключение. Полученные результаты могут быть использованы при разработке и проведении профилактических мероприятий в условиях воздействия на организм высоких концентраций фтора с последовательным применением детоксикационной, иммуномодуляторной и органопротекторной коррекции. Studying mechanisms, which maintain the body homeostasis, is particularly important in the conditions of continuous impact of adverse environmental and manufacturing factors. Long-term exposure to fluorides leads to chronic fluoric intoxication, the pathogenesis of which is a subject of multiple controversy and discussions. Not enough attention is still paid to elucidating the visceral pathology associated with fluorine-induced immune disorders. There are virtually no studies of immune reactions that define the morphofunctional nature of the liver response to early stages of fluoric intoxication. Aim. To study pathophysiological mechanisms of hepatic immune reactivity in subchronic exposure of the body to fluorine compounds. Methods. Experiments were performed on 210 male rats weighing 180-220 g. The animals were divided into two groups: 1) control (n=80) and 2) subchronic exposure to sodium fluoride (n=130). The rats had free access to a 10 mg/l aqueous solution of sodium fluoride (daily dose, 1.2 mg/kg body weight) for 12 weeks. Blood was withdrawn from the caudal vein at 1, 3, 6, 9, and 12 weeks of the experiment for immunological and biochemical tests. Histological study of the liver was performed after decapitation of rats under ether anesthesia. Results. The subchronic exposure to sodium fluoride was associated with intracellular and intravascular damage of the liver. Activation of inflammatory mediators and development of immunological disorders during the experiment contributed to a systemic inflammatory reaction, which resulted in persistent morphological injuries of the liver and changes in enzyme activities in major metabolic pathways. Conclusion. The study results can be used for development and implementation of preventive measures against the effects of high fluorine concentrations, which would include a successive use of detoxification, immunomodulation and organ protection.


Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4339
Author(s):  
Marta Mańkowska ◽  
Michał Pluciński ◽  
Izabela Kotowska ◽  
Ludmiła Filina-Dawidowicz

The world-wide crisis caused by the Coronavirus disease 2019 (COVID-19) pandemic had a significant impact on the global economy functioning and the sustainable development of supply chains. The changes also affected seaports being the key links of maritime supply chains. The purpose of the research study described in this article was to identify the sources and kinds of disruptions observed in various maritime supply chains as a result of the COVID-19 pandemic and their impact on the operations of various types of seaport terminals, namely those serving bulk (universal, specialised) and general cargoes (universal, specialised). An additional purpose was to identify the dependencies between the type of terminal and its main function, and the tactical decisions adopted by the particular terminals. The research was carried out using the multiple-case study method. The study covered some selected port terminals functioning in Polish seaports (Gdańsk, Szczecin, Świnoujście), applying direct, semi-structured in-depth interviews. The analysis of the results was carried out using the inductive reasoning method. The research study has shown that as a result of the COVID-19 pandemic some maritime supply chains ceased to exist, some of them were operating with decreased cargo volumes, while in other cases the transshipment volumes actually rose during the pandemic. Among terminal operators’ tactical responses to disruptions in maritime supply chains, there were pro-active and adaptive measures. Pro-active (offensive) measures included actions taken by an enterprise in order to engage in new maritime supply chains, and even participating in establishing new maritime chains in response to limitations caused by the pandemic. Adaptive (defensive) measures covered actions taken by the port terminals as a consequence of changes in the existing maritime supply chains, caused by the pandemic in the port’s foreland or hinterland. The research study results revealed that the terminals extent of engagement and tactical decisions related to the pandemic were depended on the type of terminal (universal or specialised) and its main function played within a supply chain.


2020 ◽  
Vol 45 (2) ◽  
pp. 40-48
Author(s):  
A. J. Atansuyi ◽  
U. C. Ihendu ◽  
C. A. Chineke

This study was conducted to determine the growth performance, correlation and regression estimates of seven-chicken strains in South-western Nigeria using a total of 300 day-old chicks. The birds were divided into seven groups based on their strain. The seven strains are Normal feather (NF), Fulani ecotype (FE), Frizzle feather (FF), naked neck (NN) and Transylvania indigenous strains while Hubbard and Marshal were meat-type exotic chickens. There were forty- five (45) unsexed day-old chicks in each strain except the Frizzle feather that were 30 in number. Completely randomized design (CRD) was used for the trial that lasted for 8 weeks. The birds were fed experimental diets ad libitum throughout the period of the study. Results showed that there were significant differences (p<0.05) in the initial and final weights of the birds. It was observed that exotic strains weighed heavier (3569.73gHB) than their indigenous counterparts (1391.11gNF). However, the Fulani ecotype weighed heaviest (1840.99g) among Nigeria indigenous strains during the experimental period. This showed that FE strains are generally heavy breed chicken and could be incorporated into a meat producing indigenous chicken if improved upon. The result of the correlation coefficients showed that a very strong, positive and highly significant (P<0.001) relationship existed between body weights and linear body measurements as most of the values are (>0.40). All the body parameter examined had significant (p<0.01) and direct relationship with the body weight. Shoulder-to-tail length (STL) had the highest coefficient of 0.98.The high correlation estimates obtained in this study could be as a result of pleiotropy, heterozygosity or linkage of genes in the birds. The three functions were highly significant (p<0.05) for all the parameters studied. This shows that the functions well described the parameters. On the basis of coefficient of determination (R ), the body weight of poultry birds at any age can be predicted most accurately with BRG using cubic function.


Author(s):  
Nageeb AGM Hassan ◽  
Sabrina Ait Gacem ◽  
Afnan Abdul-Hameed Al-Qaysi ◽  
Maryam Jaafar AlAani

Background: Most of individuals do not prefer consulting a physician when they suffer from mild to moderate pain or fever and they tend to get over the counter drugs (OTC) from the pharmacy. Non-steroidal anti-inflammatory (NSAIDs) consumption pattern and self-medication behavior is a common practice especially during adolescence. Many self-medication behaviors were observed from individuals especially students which use NSAIDs frequently and that might lead to some unwanted effects due to improper knowledge and awareness. Although NSAIDs are considered as safe medications in general, but serious side effects are still present and can affect different parts of the body. Objectives: Our study aims to assess the correlation between several types of pain and self-medication pattern of Paracetamol and NSAIDs among university students in UAE. Methods: This was a cross-sectional study that was conducted among individuals aged 17 years and above from different nationalities and specialties from June till July 2018. The data were obtained through a validated self-administrated questionnaire that was distributed as a hardcopy as well as online. Data collection took place in UAE universities targeting 345 university students. The data were analyzed using SPSS version 20 and the results were considered significant at the 0.05 level with a 95% Confidence interval. Results: The current study results show that (67%) of individuals use pain medications to relief pain associated with headache. The majority of individuals reported that they suffer from pain at least one day weekly (26.4%). The pain that mostly led individuals to take pain medications is headache and it is accounts for (67%). The most frequently used pain medication is Paracetamol (80.9%) followed by Ibuprofen, Mefenamic acid and Diclofenac (35.4%, 17.1% and 13.6%) respectively. It was observed that (28.4%) of individuals use more than one pain medication at the same time. The results show that there was a significant correlation between the intake of Mefenamic acid for pain and individuals that reported the use of pain medications for menstrual pain [p=0.000, OR: 5.223, 95% CI: 2.73 - 9.96]. The significant intake of Aspirin for back pain [p=0.020, OR: 3.239, 95% CI: 1.159 - 9.05] and Diclofenac for both muscles pain and back pain back pain [p=0.000, OR: 3.061, 95% CI: 1.792 - 5.228), p=0.000, OR: 3.037, 95% CI: 1.789 - 5.15 respectively] and Paracetamol for both toothache and fever [p=0.002, OR: 1.220, 95% CI: 1.120 - 1.32 and p=0.044, OR: 1.137, 95% CI: 1.027 - 1.259 respectively]. The following NSAIDs showed a significant correlation with the intake of pain medications for toothache: Aspirin [p=0.018, OR: 3.167, 95% CI: 1.171 - 8.56], Ibuprofen [p=0.004, OR: 1.618, 95% CI: 1.201 - 2.17] and Diclofenac [p=0.000, OR: 2.692, 95% CI: 1.591 - 4.55]. Only Paracetamol was found to have a significant correlation for the use during fever [p=0.044, OR: 1.137, 95% CI: 1.027 - 1.259] while other pain medications were found to have a negative correlation. Conclusion: The majority of respondents use the pain medications to relief headache and the most frequently used pain medication was Paracetamol. A significant correlation was observed between the intake of Mefenamic acid for pain and individuals that reported the use of pain medications for menstrual pain as well as Aspirin intake for back pain, Diclofenac for muscles pain and back pain. Only Paracetamol was found to have a significant correlation for the use during fever while other pain medications were found to have a negative correlation.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Chunhui Huo ◽  
Javaria Hameed ◽  
Muhammad Waqas Sadiq ◽  
Gadah Albasher ◽  
Wedad Alqahtani

PurposeThis paper aims to provide a valid insight into consumers' minds while considering word of mouth (WOM), brand image and uniqueness as independent variables while considering the tourism industry as the primary stakeholder.Design/methodology/approachThe study adopts qualitative research methods and data collected from 1,033 respondents using convenience sampling methodology. The data are collected from different tourists spots in China and Pakistan. The PROCESS macro was utilized in this study using SPSS version 25.0 to inspect the impacts by using Model 4 and the conditional effects indirectly by utilizing Model 14.FindingsCustomer's intimacy, search for novel and unexplored destinations highlight WOM interactions and perceived service value. Service value, interactional justice and professional attitude of hotel management mediated all the given relationships significantly. The brand image does not mediate any significant associations. Perceived service value and brand image predict customer's loyalty, and WOM is the direct measure of their intentions, and these variables are market trend indicators. A tourist's response toward different destinations is described in this study with comparative analysis of Chinese and Pakistani tourists. The study results showed a significantly positive relationship between hotel management professional behavior, customer's loyalty, customer's intimacy and WOM.Research limitations/implicationsThe recruited population might not be represented as the broader and larger visitor population, resulting in restricting establishing tactics. Moreover, this study's results provide significant insight into a tourism industry, hence providing a chance to manage customer loyalty better.Social, managerial and theoretical implicationsThis study contributes significantly to the body of knowledge and provides remarkable insight from the managerial perspective. Interactional justice results in significant value for hotel management directors and top management, front desk staff and operatives and front level employees and managers. Consumer sensitivity of fairness in interpersonal dealings calls for behavioral changes in frontline employees, especially those directly dealing with hotel visitors. Hotel staff and management should formulate a system to deal with the demands and needs of visitors. It should describe the rights and obligations of visitors and ensure that each customer is treated equally and with respect. Customers should be motivated to read the survey questionnaires kept in their rooms and offer their views on the services provided. This strategy might increase the customers' sense of empowerment and leading to notions of fairness in individual encounters.Originality/valueThis study provides an insight into the customer's minds while considering essential variables that include WOM, brand image, perceived service value and uniqueness.


2016 ◽  
Vol 12 (5) ◽  
pp. 24
Author(s):  
Majed F. Mujalli ◽  
Maen Z. Zakarneh ◽  
Ala’a Kh. Abu Aloyoun

<p>The aim of the study was to investigate the common sports injuries among physical activities practitioners at the physical fitness centers in Jordan. Study sample consisted of (272) volunteered male (n=221) and female (n=51) (age 30±3). Researchers used a special form used to evaluate athletic injuries. After collecting and analyzing the data. Results showed that the most common sports injuries among sample of the study was muscular tears 27.7%, muscle spasm 20.7%, and tears ligament 20.2%. And the most exposed parts of the body to injury is the lumbar area 26.8%, elbows 16.9%, followed by shoulders 8.9%. Also the study results revealed that the most cusses of injuries was over training 24.14%. Poor warm-up 22.1% and bad technic 11.3%. Bodies-building was the most type of activities subjects to injury with 18.8%. Physical Fitness 6.6% and weight loss 27.7. Results also showed that physical therapy was the most means of treating injuries 54.14%, drugs therapy 33.3% and surgical intervention 4.2%. Also the study shows that males are more exposed to injuries than females.</p><p>Conclusions: These finding indicate that sports injures is part of physical</p><p>Activities participations, preventive measures should be taken by participant's the researchers recommended the need for physical and medical checkup before participation in physical activity at the physical fitness centers.</p>


2019 ◽  
Vol 47 (1) ◽  
pp. 37-47 ◽  
Author(s):  
Heather Moorefield-Lang

Purpose What happens when a librarian outgrows their maker learning location or transfers to a new library? The purpose of this study is to explore the planning process for second and/or new library makerspaces. Is the planning more intentional? Is there more focus on how the makerspace should be put together for the community served? Is the community further involved? This study will explore those questions and more. Design/methodology/approach Using content analysis, the perspectives of practicing librarians in the achievement of subsequent makerspaces are examined. Data include librarian interviews, an analysis using NVivo 11 through the lens of design thinking, and a final review using member checking by each research participant. Findings Makerspaces continue to grow in popularity in school and public/community libraries. What is unexplored is the moving from a first makerspace to the implementation of a second and/or new maker learning location. More intentional planning is involved. The community served by the library is further engaged in the planning. Study results illustrate the value that community insight and intentional planning play in the design and implementation of makerspaces. Originality/value Makerspaces in libraries continue to grow in popularity; in turn, the body of peer-reviewed, scholarly publications also continues to grow. Librarians in the field are beginning to move from their first to second makerspaces. This study investigates those perspectives. Much can be gained from the experiences of those who have implemented their second or third makerspace.


2013 ◽  
Vol 594-595 ◽  
pp. 503-510
Author(s):  
T.I.T. Noor Hasanah ◽  
D.C. Wijeyesekera ◽  
Ismail bin Bakar ◽  
Wahab Saidin

Applications of lightweight construction materials enable the design and construction in challenging, difficult and demanding scenarios. Construction materials with enhanced stiffness as in sandwich panels, large portable structures and floating foundations are examples of such materials. The advent of cellular structure technology has actively introduced innovation and enabled design and construction, meeting engineering requirements such as in the construction of the body of air crafts. Cellular mat structures present in the minimum, triple benefits in being lightweight, load sharing and minimising non-uniform deformation. This paper further explores the use of recycled plastic waste as the base material for an innovative geomaterial. The combination of cellular structure, mat structure and use of recycled waste material is a desirable development in manufacturing. Paper also outlines the techno social benefit of adopting such material in construction. Other application-specific benefits related to cellular mats are those like noise reduction, energy absorption, thermal insulation, mechanical damping. This paper specifically presents the development of a new multifunctional lightweight material is been proposed as an invective innovation for highway construction on challenging ground condition.


2005 ◽  
Vol 133 (Suppl. 1) ◽  
pp. 9-15 ◽  
Author(s):  
Marija Mostarica-Stojkovic

The main function of the immune system is to protect the body by responding to invading microorganisms. Immunologic tolerance is the basic property of the immune system that provides for self/non-self discrimination so that the immune system can protect the host from external pathogens without reacting against itself. Central tolerance is achieved by the clonal deletion of self-reactive lymphocytes expressing receptors with high avidity for self. Autoreactive lymphocytes which escaped selection in the central lymphoid organs are present in the peripheral repertoire but but are kept under control by multiple diverse peripheral tolerance mechanisms acting either directly on the self-reactive T cell (T-cell intrinsic) or indirectly via additional cells (T-cell extrinsic). Intrinsic mec hanisms include ignorance of autoantigens, anergy, phenotype skewing or activation-induced cell death of autoreactive T lymphocytes, while extrinsic mechanisms act through immature and/ or tolerogenic dendritic cells as well as different types of regulatory cells. Autoimmune diseases are associated with humoral or cell-mediated immune reactions against one or more of the body?s own constituents. Activation and clonal expansion of autoreactive lymhocytes is a crucial step in the pathogenesis of autoimmune diseases. They result from the complex interactions between genetic traits and environmental factors, among which infections are the most likely cause. Several basic mechanisms may be operating whereby an infectious agent actually induces apparent autoimmne reactivity including molecular mimicry, bystander activation, induction of costimulation, polyclonal activation, altered processing and expression of cryptic antigens. Although many questions regarding autotolerance and etiop athogenestis of autoimmunity have yet to be resolved, it is evident that multiple overlapping pathways are operative in establishing, maintaining and breaking autotolerance, as well as during the initiation, progression, and final effector phases of autoimmunity.


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