scholarly journals An improved and highly efficient geometry for facemasks

2021 ◽  
Author(s):  
Christopher Cappa ◽  
William Ristenpart ◽  
Santiago Barreda ◽  
Nicole Bouvier ◽  
Anthony Wexler ◽  
...  
Keyword(s):  
Respiratory Diseases ◽  
High Efficiency ◽  
Ambient Aerosols ◽  
The Public ◽  
Professional Singers ◽  
Surgical Masks ◽  
Mask Design ◽  
Different Populations ◽  
N95 Respirators ◽  
Better Than

Abstract Wearing masks and face coverings helps reduce transmission of respiratory diseases. Various mask designs exist that target different populations, occupations, and environments. Here, we present evidence that a new facemask design, originally made for professional singers, offers advantages that will strongly benefit the public. Specifically, we show that with proper fitting the reusable cloth singing mask achieves overall filtering efficiencies for both exhaled expiratory aerosols and for inhaled ambient aerosols of >93%, better than surgical masks and approaching N95 respirators. We attribute the high efficiency largely to the mask design, rather than material. The mask design also provides for less inhibited mouth and jaw movement and overall lower humidity within the mask, suggesting it may provide a more palatable, high-efficiency alternative to medical-grade masks for the public.

scholarly journals A highly efficient cloth facemask

2021 ◽  
Author(s):  
Christopher Cappa ◽  
The San Francisco Opera Costume Department ◽  
William Ristenpart ◽  
Santiago Barreda ◽  
Nicole Bouvier ◽  
...  
Keyword(s):  
High Efficiency ◽  
Separation Distance ◽  
Filtration Efficiency ◽  
Ambient Aerosols ◽  
The Public ◽  
Professional Singers ◽  
Surgical Masks ◽  
Mask Design ◽  
N95 Respirators ◽  
Better Than

Abstract Wearing masks and face coverings helps reduce transmission of respiratory diseases. Much prior research on mask filtration efficiency has focused on fabric type, with less consideration given to mask design and shape. Here, we present evidence that increasing the mouth-mask separation distance engenders an increase in the mask-fabric filtration efficiency towards expiratory aerosols emitted via vocalization, which we attribute to a decrease in the expiratory jet velocity and expansion of the breath-mask contact area. We further assess the performance of a new reusable cloth facemask design, originally made for, but not exclusive to, professional singers and having a large mouth-mask separation distance. With proper fitting, these masks achieve overall filtering efficiencies of >93% for both exhaled expiratory aerosols >0.5 microns in diameter from singing and speaking and for inhaled ambient aerosols, better than surgical masks and approaching N95 respirators. Air exchange between the mask deadspace and the ambient environment limits the extent of CO2 buildup and in inhaled air and maintains O2 levels near ambient. The mask design also provides for less inhibited mouth and jaw movement and lower relative humidity, suggesting it may provide a more palatable, high-efficiency alternative to medical-grade masks for the public.

scholarly journals An improved and highly efficient geometry for facemasks

2021 ◽  
Author(s):  
Christopher Cappa ◽  
William Ristenpart ◽  
Santiago Barreda ◽  
Nicole Bouvier ◽  
Anthony Wexler ◽  
...  
Keyword(s):  
High Efficiency ◽  
Separation Distance ◽  
Filtration Efficiency ◽  
Ambient Aerosols ◽  
The Public ◽  
Professional Singers ◽  
Surgical Masks ◽  
Mask Design ◽  
N95 Respirators ◽  
Better Than

Abstract Wearing masks and face coverings helps reduce transmission of respiratory diseases. Much prior research on mask filtration efficiency has focused on fabric type, with little consideration given to mask geometry. Here, we present evidence that increasing the mouth-mask separation distance engenders an increase in the mask-fabric filtration efficiency towards expiratory aerosols emitted via vocalization, which we attribute to a decrease in the expiratory jet velocity. We further assess the performance of a new reusable cloth facemask design, originally made for professional singers and having a large mouth-mask separation distance. With proper fitting, these masks achieve overall filtering efficiencies of >93% for both exhaled expiratory aerosols from singing and speaking and for inhaled ambient aerosols, better than surgical masks and approaching N95 respirators. The mask design also provides for less inhibited mouth and jaw movement, suggesting it may provide a more palatable, high-efficiency alternative to medical-grade masks for the public.

scholarly journals Short Communication: Health Interventions in Volcanic Eruptions—Community Wearability Assessment of Respiratory Protection against Volcanic Ash from Mt Sinabung, Indonesia

2018 ◽  
Vol 15 (11) ◽  
pp. 2359 ◽  
Author(s):  
Karen Galea ◽  
Judith Covey ◽  
Sari Mutia Timur ◽  
Claire Horwell ◽  
Fentiny Nugroho ◽  
...  
Keyword(s):  
Volcanic Ash ◽  
Short Communication ◽  
High Efficiency ◽  
Volcanic Eruptions ◽  
The Other ◽  
Respiratory Protection ◽  
Industry Standards ◽  
Surgical Masks ◽  
Over The Top ◽  
Better Than

Inhalation of ash can be of great concern for affected communities, during and after volcanic eruptions. Governmental and humanitarian agencies recommend and distribute a variety of respiratory protection (RP), commonly surgical masks but, also, industry-certified N95-style masks. However, there is currently no evidence on how wearable they are within affected populations or how protective wearers perceive them being against volcanic ash (which will influence the likelihood of uptake of recommended interventions). Volunteers living near Mt. Sinabung, Sumatra, Indonesia, participated in a field wearability study, which included a high-efficiency mask certified to industry standards (N95-equiv.); a standard, pleated surgical mask (Surgical); a Basic flat-fold mask (Flat-fold), and the surgical mask plus a scarf tied over the top (Surgical Plus) to improve fit. These types of RP had all performed well during earlier laboratory filtration efficiency tests. The N95-equiv. mask had performed significantly better than the other RP in the subsequent total inward leakage volunteer trials, whilst the Flat-fold and Surgical masks performed poorly, letting in a third of PM2.5 particles (data published elsewhere). Thirty volunteers wore each mask for a 15-min walk before being asked to rate the comfort, breathability and perceived protection and fit of each. After wearing all of the masks, volunteers compared and identified their preferred type of protection. The feedback received from the volunteers suggested that the Surgical Plus and N95-equiv. masks were rated as being significantly hotter and more humid than other masks. The Flat-fold was rated to have better breathability than the other masks. The N95-equiv. mask was ranked as providing the best level of effectiveness of the four masks tested. Ultimately, when asked which type of mask they would choose to wear during ashfall, 33% selected the Flat-fold mask due to its comfort and simplicity, with the Surgical Plus being the least likely to be chosen of the four tested. The study findings are of benefit to agencies who need to make informed decisions on the procurement and distribution of RP for use by those affected in future eruptions and the provision of advice to communities on their usage.

Determinants of English as language choice among Unaccompanied Migrant Children (UMC) in Makassar, Indonesia

2019 ◽  
Vol 2 (2) ◽  
pp. 1-7
Author(s):  
Andi Samsu Rijal ◽  
Andi Mega Januarti Putri
Keyword(s):  
Language Choice ◽  
Migrant Children ◽  
Immigrant Communities ◽  
The Public ◽  
International Language ◽  
Language User ◽  
Public Area ◽  
Better Than ◽  
Language Mastery

The essence of language is human activity. Communication with language is carried out through two basic human activities; speaking and listening during the interaction in a group of people. Immigrants in Makassar city communicate with immigrant communities and Makassar people. They used English and Indonesia to communicate with others. The aims of this article were to find out determinant factors of English as language choice among Unaccompanied Migrant Children (UMC) in Makassar and why they used English as their language choice to communicate with other people out of them. The data were taken from UMC in the shelter under the auspices of Makassar’s Social Office and in the public area of Makassar. This research was a qualitative approach; it was from a sociolinguistic perspective and focuses its analysis with the language choice among UMC. This research showed that most immigrants chose English as their language choice since they were in Makassar because they have acquired better than other international language and it has been mastered naturally by doing social interaction among themselves and people outside their community. UMC had more difficulties to socialize with Indonesian than the adult of Immigrants. Other than their lack of language mastery, they also have the anxiety to adapt to other immigrants and Makassar people. English was used by UMC to show their status as a foreigner who lived in a multicultural situation. Language becomes a power for a human being and it becomes a social identity for language user in one community. During the interaction of UMC in Makassar city, the role of English as an International language is shown.

MUNDANE MIRACLES IN AWADH. ENCOUNTERS WITH THE REVEALED AND THE HIDDEN

2020 ◽  
pp. 130-140
Author(s):  
Maxim B. Demchenko ◽  
Keyword(s):  
The Other ◽  
Local People ◽  
Natural Phenomena ◽  
Mughal Empire ◽  
The Public ◽  
British Raj ◽  
The Subject ◽  
Other World ◽  
Better Than

The sphere of the unknown, supernatural and miraculous is one of the most popular subjects for everyday discussions in Ayodhya – the last of the provinces of the Mughal Empire, which entered the British Raj in 1859, and in the distant past – the space of many legendary and mythological events. Mostly they concern encounters with inhabitants of the “other world” – spirits, ghosts, jinns as well as miraculous healings following magic rituals or meetings with the so-called saints of different religions (Hindu sadhus, Sufi dervishes),with incomprehensible and frightening natural phenomena. According to the author’s observations ideas of the unknown in Avadh are codified and structured in Avadh better than in other parts of India. Local people can clearly define if they witness a bhut or a jinn and whether the disease is caused by some witchcraft or other reasons. Perhaps that is due to the presence in the holy town of a persistent tradition of katha, the public presentation of plots from the Ramayana epic in both the narrative and poetic as well as performative forms. But are the events and phenomena in question a miracle for the Avadhvasis, residents of Ayodhya and its environs, or are they so commonplace that they do not surprise or fascinate? That exactly is the subject of the essay, written on the basis of materials collected by the author in Ayodhya during the period of 2010 – 2019. The author would like to express his appreciation to Mr. Alok Sharma (Faizabad) for his advice and cooperation.

scholarly journals Performance of Seven Consumer Sleep-Tracking Devices Compared with Polysomnography

SLEEP ◽  
2020 ◽  
Author(s):  
Evan D Chinoy ◽  
Joseph A Cuellar ◽  
Kirbie E Huwa ◽  
Jason T Jameson ◽  
Catherine H Watson ◽  
...  
Keyword(s):  
Performance Measures ◽  
Gold Standard ◽  
High Performance ◽  
Sleep Stage ◽  
Sleep Laboratory ◽  
Sleep Assessment ◽  
Sleep Condition ◽  
Different Populations ◽  
Tracking Devices ◽  
Better Than

Abstract Study Objectives Consumer sleep-tracking devices are widely used and becoming more technologically advanced, creating strong interest from researchers and clinicians for their possible use as alternatives to standard actigraphy. We therefore tested the performance of many of the latest consumer sleep-tracking devices, alongside actigraphy, versus the gold-standard sleep assessment technique, polysomnography (PSG). Methods In total, 34 healthy young adults (22 women; 28.1 ± 3.9 years, mean ± SD) were tested on three consecutive nights (including a disrupted sleep condition) in a sleep laboratory with PSG, along with actigraphy (Philips Respironics Actiwatch 2) and a subset of consumer sleep-tracking devices. Altogether, four wearable (Fatigue Science Readiband, Fitbit Alta HR, Garmin Fenix 5S, Garmin Vivosmart 3) and three non-wearable (EarlySense Live, ResMed S+, SleepScore Max) devices were tested. Sleep/wake summary and epoch-by-epoch agreement measures were compared with PSG. Results Most devices (Fatigue Science Readiband, Fitbit Alta HR, EarlySense Live, ResMed S+, SleepScore Max) performed as well as or better than actigraphy on sleep/wake performance measures, while the Garmin devices performed worse. Overall, epoch-by-epoch sensitivity was high (all ≥0.93), specificity was low-to-medium (0.18-0.54), sleep stage comparisons were mixed, and devices tended to perform worse on nights with poorer/disrupted sleep. Conclusions Consumer sleep-tracking devices exhibited high performance in detecting sleep, and most performed equivalent to (or better than) actigraphy in detecting wake. Device sleep stage assessments were inconsistent. Findings indicate that many newer sleep-tracking devices demonstrate promising performance for tracking sleep and wake. Devices should be tested in different populations and settings to further examine their wider validity and utility.

scholarly journals High-Efficiency Intracavity Continuous-Wave Green-Light Generation by Quasiphase Matching in a Bulk Periodically Poled MgO:LiNbO3 Crystal

2008 ◽  
Vol 2008 ◽  
pp. 1-4 ◽  
Author(s):  
Shaowei Chu ◽  
Ying Zhang ◽  
Bin Wang ◽  
Yong Bi
Keyword(s):  
High Efficiency ◽  
Continuous Wave ◽  
Green Light ◽  
Frequency Doubling ◽  
Green Laser ◽  
Periodically Poled ◽  
Output Stability ◽  
532 Nm ◽  
Better Than ◽  
Quasiphase Matching

908 mW of green light at 532 nm were generated by intracavity quasiphase matching in a bulk periodically poled MgO:LiNbO3 (PPMgLN) crystal. A maximum optical-to-optical conversion efficiency of 33.5% was obtained from a 0.5 mm thick, 10 mm long, and 5 mol% MgO:LiNbO3 crystal with an end-pump power of 2.7 W at 808 nm. The temperature bandwidth between the intracavity and single-pass frequency doubling was found to be different for the PPMgLN. Reliability and stability of the green laser were evaluated. It was found that for continuous operation of 100 hours, the output stability was better than 97.5% and no optical damage was observed.

YOU ARE WHAT THEY SEE

PEDIATRICS ◽  
1977 ◽  
Vol 60 (3) ◽  
pp. 312-312
Author(s):  
P. H. Rhodes
Keyword(s):  
Education And Training ◽  
Public Image ◽  
Value Judgments ◽  
The Public ◽  
High Level ◽  
And Training ◽  
Better Than

The value judgments about medicine are contributed to by the public image. Formerly this has been one of a devoted, caring, self-sacrificing, somewhat unworldly group of people, dedicated to their work for the suffering and diseased. But the doctors are not separate from society and they are affected by its values. These have been adopted by the profession so that it is coming to be seen as no worse and no better than any other group of comparable education and training. Its status has diminished and this has called into question its compensation at a high level. Status cannot be maintained when its base has been eroded.

New opportunities of halotherapy in the prevention and medical rehabilitation of children

2021 ◽  
pp. 37-47
Author(s):  
Alina Vyacheslavovna Chervinskaya ◽  
Irena Vladimirovna Pogonchenkova ◽  
Maya Alekseevna Khan ◽  
Natalya Anatolievna Mikitchenko ◽  
Natalya Anatolievna Lyan
Keyword(s):  
Sodium Chloride ◽  
Bronchial Asthma ◽  
Respiratory Diseases ◽  
High Efficiency ◽  
Medical Rehabilitation ◽  
Favorable Effect ◽  
Group Method ◽  
Biophysical Properties ◽  
Pediatric Practice ◽  
Highly Dispersed

The article is devoted to new possibilities of using halotherapy in the prevention, treatment and medical rehabilitation of children. In recent years, active work has been carried out to develop new effective methods of reproducing the aerodispersed medium in the form of haloingalation therapy or by group method — in the conditions of a halochamber. The therapeutic effect of halotherapy is determined by the biophysical properties of a dry highly dispersed aerosol of sodium chloride. The paper presents the biophysical properties of the main active factor of halotherapy, i.e. a dry highly dispersed aerosol of sodium chloride, and reveals some aspects of the formation of the mechanism of therapeutic action. The anti-inflammatory, draining, mucolytic, immunomodulatory, sanogenetic effect of haloaerosol is shown. In pediatric practice, haloaerosol therapy is used for medical rehabilitation of children with respiratory diseases (bronchial asthma, bronchitis), ENT pathology (rhinosinusitis, tonsillitis, pharyngitis), skin diseases. Halotherapy is the method of choice in the prevention of acute respiratory diseases and improving the health of children in general education institutions. The high efficiency of the complex application of halotherapy in various diseases in children has been established. A promising direction for the development of halotherapy is the development of combined exposure technologies. The high efficiency of the use of haloingalation therapy in combination with magnetic therapy in the treatment of acute rhinosinusitis in children has been proven. Based on the conducted studies, a favorable effect of the use of halotherapy and flutter therapy on clinical and functional parameters in children with bronchial asthma was revealed. The data on the possibility of combined use of halotherapy with a pulsed low-frequency electrostatic field in the medical rehabilitation of children suffering from bronchial asthma are presented. Simplicity, safety, the possibility of personalization of exposure and good tolerability by children expands the possibilities for using halotherapy in pediatric practice.

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