scholarly journals Investigation of the bubble structure of hail droplet nuclei

2021 ◽  
Vol 840 (1) ◽  
pp. 012009
Author(s):  
A B Khuchunaev
Keyword(s):  
Bubble Structure ◽  
Droplet Nuclei

scholarly journals Peering inside a cough or sneeze to explain enhanced airborne transmission under dry weather

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kai Liu ◽  
Majid Allahyari ◽  
Jorge S. Salinas ◽  
Nadim Zgheib ◽  
S. Balachandar
Keyword(s):  
High Fidelity ◽  
Substantial Variation ◽  
Ambient Conditions ◽  
Airborne Transmission ◽  
Social Distancing ◽  
Virtual Experiments ◽  
Long Time ◽  
Simulation Results ◽  
High Fidelity Simulations ◽  
Droplet Nuclei

AbstractHigh-fidelity simulations of coughs and sneezes that serve as virtual experiments are presented, and they offer an unprecedented opportunity to peer into the chaotic evolution of the resulting airborne droplet clouds. While larger droplets quickly fall-out of the cloud, smaller droplets evaporate rapidly. The non-volatiles remain airborne as droplet nuclei for a long time to be transported over long distances. The substantial variation observed between the different realizations has important social distancing implications, since probabilistic outlier-events do occur and may need to be taken into account when assessing the risk of contagion. Contrary to common expectations, we observe dry ambient conditions to increase by more than four times the number of airborne potentially virus-laden nuclei, as a result of reduced droplet fall-out through rapid evaporation. The simulation results are used to validate and calibrate a comprehensive multiphase theory, which is then used to predict the spread of airborne nuclei under a wide variety of ambient conditions.

Fiber-tip bubble-structure microcavity sensor

2014 ◽  
Author(s):  
D. Chen ◽  
S. Luo ◽  
X. Ma ◽  
X. Jiang ◽  
G. Feng ◽  
...  
Keyword(s):  
Bubble Structure

Flow visualization of bubble structure in bubble column reactor for fluid mixing

2017 ◽  
Author(s):  
Nur Afizah Ibrahim ◽  
Amir Khalid ◽  
Izzuddin Zaman ◽  
Azwan Sapit ◽  
Bukhari Manshoor
Keyword(s):  
Flow Visualization ◽  
Bubble Column ◽  
Fluid Mixing ◽  
Bubble Column Reactor ◽  
Column Reactor ◽  
Bubble Structure

Airborne Contagion and Air Hygine

PEDIATRICS ◽  
1956 ◽  
Vol 17 (5) ◽  
pp. 802-802
Author(s):  
FRAKLIN H. TOP
Keyword(s):  
Experimental Method ◽  
Golden Age ◽  
Infectious Agents ◽  
Half Century ◽  
Past Half Century ◽  
Spread Of Infection ◽  
Droplet Nuclei ◽  
Past Half

The transmission of infections affecting man has been the object of much thought, theory and conjecture for many centuries. Host to host transfer of infectious agents remained largely in the province of speculation until the "Golden Age of Bacteriology" and the succeeding era of discovery of viruses. In the immediate past half century the experimental method has added considerably to the proposition that certain agents pathogenic to man are transmitted by air. Well's book is a scholarly treatise on a subject to which he has given earnest consideration for over 20 years, namely, the importance of droplets, droplet nuclei and dust in the spread of infection.

scholarly journals TUBERCULOSIS OF RABBITS INDUCED BY DROPLET NUCLEI INFECTION

1948 ◽  
Vol 87 (6) ◽  
pp. 585-594 ◽  
Author(s):  
H. L. Ratcliffe ◽  
W. F. Wells
Keyword(s):  
Inflammatory Response ◽  
Linear Relationship ◽  
Normal Control ◽  
Acquired Resistance ◽  
Single Exposure ◽  
Initial Infection ◽  
Development Of Resistance ◽  
Droplet Nuclei ◽  
Initial Lesions

At intervals from 2 to 11 weeks after normal rabbits had inhaled small numbers of virulent bovine tubercle bacilli as separated cells in droplet nuclei, groups of these animals received a single exposure to reinfection during which each animal inhaled about 20,000 separated bacilli. Normal control rabbits which inhaled this large number of bacilli died within 4 weeks thereafter. Their deaths were attributed to destruction of the lungs by developing initial tubercles. Eleven of 12 rabbits which were reinfected within 4 weeks after initial infection seemed to respond as normal animals. Their lungs were largely replaced by developing reinfection tubercles when they died or were killed within 32 days after reinfection. The inflammatory response of the reinfection tubercles was not consistently different from that of initial tubercles, although reinfection tubercles contained fewer bacilli than initial lesions of the same age. Within 5 weeks after initial infection rabbits apparently had developed immunity to reinfection with virulent bovine tubercle bacilli inhaled as separated cells in droplet nuclei. In some of them, however, exposure to massive inhaled reinfection seemed to stimulate the progress of initial infection. It is suggested that in rabbits the development of resistance to tubercle bacilli does not bear a linear relationship to time, but progresses in steps and within 5 weeks after small initial infection by inhalation is adequate to prevent the growth of separated bacilli when these are deposited upon alveolar walls. It is suggested also that the basic effect of acquired resistance of rabbits to tubercle bacilli is inhibition of multiplication of the bacilli.

scholarly journals Pneumococcal pneumonia and invasive pneumococcal disease: immunopathogenesis and diagnosis

Pneumologia ◽  
2019 ◽  
Vol 68 (1) ◽  
pp. 8-14
Author(s):  
Gina Amanda ◽  
Dianiati Kusumo Sutoyo ◽  
Erlina Burhan
Keyword(s):  
Immune System ◽  
Invasive Pneumococcal Disease ◽  
Pneumococcal Disease ◽  
Pneumococcal Pneumonia ◽  
Bacterial Load ◽  
Adaptive Immune System ◽  
Signs And Symptoms ◽  
Community Acquired Pneumonia ◽  
High Bacterial Load ◽  
Droplet Nuclei

Abstract Streptococcus pneumoniae is the most common aetiology of community-acquired pneumonia (CAP). It has many virulence factors, the most important being a polysaccharide capsule (Cps). There are 97 different serotypes of pneumococcal based on Cps which include both colonization and invasive serotypes. Pneumococcal pneumonia may exist as a result of either aspiration of bacteria in the nasopharynx or inhalation of droplet nuclei which contains bacteria until they reach the lower respiratory tract. This condition will activate both innate and adaptive immune system. The diagnosis of pneumococcal pneumonia is established in a patient who has the signs and symptoms of pneumonia, accompanied by the detection of S. pneumoniae in microbiology examination. Pneumococcus may also penetrate into a normally sterile site such as bloodstream, meninges, and pleural cavity, and infection of pneumococcus in those sites are defined as an invasive pneumococcal disease (IPD). High bacterial load, dysfunction of the immune system, and co-colonization of another microorganism may also lead to IPD.

scholarly journals KNOWLEDGE, ATTITUDE, AND PRACTICE OF COUGH ETIQUETTE IN PATIENTS WITH TUBERCULOSIS IN THE COMMUNITY HEALTH CENTERS

2018 ◽  
Vol 4 (5) ◽  
pp. 482-491
Author(s):  
Desy Indra Yani ◽  
Yayat Fajar Hidayat ◽  
Afif Amir Amrullah
Keyword(s):  
Community Health ◽  
Community Health Centers ◽  
Acid Fast Bacillus ◽  
Mean Value ◽  
Health Care Facilities ◽  
Health Centers ◽  
Cross Sectional ◽  
Attitude And Practice ◽  
Droplet Nuclei ◽  
Knowledge Attitude And Practice

Background: Tuberculosis is the major global health problem. A high number of tuberculosis cases are as a result of the disease spreads through droplet nuclei which mainly through a cough. Transmission prevention of tuberculosis is important to lower the rate of new infection. Since the transmission is through a cough, therefore, one of the preventive behaviors is by implementing the good and right cough etiquette. Objectives: The aim of this study was to find out the overview of knowledge, attitude and practice of cough etiquette in patients with tuberculosis. Methods: This study was descriptive quantitative with the cross-sectional approach. The population were all patients with Acid-Fast Bacillus (AFB) and tuberculosis registered in Community Health Centers of Rancaekek, Linggar and Nanjung Mekar in Bandung, Indonesia. A total sampling was used with a total number of 52 patients. Data on knowledge, attitude, and practice were measured via validated questionnaires and observation sheets. Frequency distribution, mean and median were used for data analysis. Results: Of the total respondents, 65.4% of the respondents had good knowledge about cough etiquette (median value 83.33 and IQR 20), 50.9% had negative cough etiquette attitude (mean value 47.87 and SD 5.885), and 63.5% had bad practice in cough etiquette (median value 5 and IQR 2). Conclusions: The result of this study is expected to be an input for primary health care facilities in doing improvement in delivering health education to patients with tuberculosis and their families about the good and right cough etiquette, which focus on the affective and psychomotor aspects to prevent the spread of tuberculosis and decrease its infection. This article has been corrected. A separate erratum can be seen at  https://doi.org/10.33546/bnj.1153

scholarly journals A Numerical Study of the Formation of a Conical Cavitation Bubble Structure at Low Ultrasonic Frequency

2015 ◽  
Vol 70 ◽  
pp. 1070-1073 ◽  
Author(s):  
C. Vanhille ◽  
C. Campos-Pozuelo ◽  
C. Granger ◽  
B. Dubus
Keyword(s):  
Cavitation Bubble ◽  
Numerical Study ◽  
Ultrasonic Frequency ◽  
Bubble Structure
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