scholarly journals The Silent Path: The Development of the Single Sleeve Valve Two-Stroke Engine over the Last 110 Years

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 616
Author(s):  
Robert Head ◽  
James Turner
Keyword(s):  
Thermal Expansion ◽  
Gas Exchange ◽  
20Th Century ◽  
Combustion Engine ◽  
Head Cooling ◽  
Initial Work ◽  
Valve Engine ◽  
Operational Issues ◽  
Stroke Engine ◽  
Over Time

At the beginning of the 20th century the operational issues of the Otto engine had not been fully resolved. The work presented here seeks to chronicle the development of one of the alternative design pathways, namely the replacement for the gas exchange mechanism of the more conventional poppet valve arrangement with that of a sleeve valve. There have been several successful engines built with these devices, which have a number of attractive features superior to poppet valves. This review moves from the initial work of Charles Knight, Peter Burt, and James McCollum, in the first decade of the 20th century, through the work of others to develop a two-stroke version of the sleeve-valve engine, which climaxed in the construction of one of the most powerful piston aeroengines ever built, the Rolls-Royce Crecy. After that period of high activity in the 1940s, there have been limited further developments. The patent efforts changed over time from design of two-stroke sleeve-drive mechanisms through to cylinder head cooling and improvements in the control of the thermal expansion of the relative components to improve durability. These documents provide a foundation for a design of an internal combustion engine with potentially high thermal efficiency.

Language Change and Movement as Seen by Historical Linguistics

2018 ◽  
Author(s):  
Derek Nurse
Keyword(s):  
West Africa ◽  
20Th Century ◽  
Language Change ◽  
Historical Linguistics ◽  
Linguistic Features ◽  
Time And Space ◽  
Change Over Time ◽  
Comparative Linguistics ◽  
Language Boundaries ◽  
Over Time

The focus of this chapter is on how languages move and change over time and space. The perceptions of historical linguists have been shaped by what they were observing. During the flowering of comparative linguistics, from the late 19th into the 20th century, the dominant view was that in earlier times when people moved, their languages moved with them, often over long distances, sometimes fast, and that language change was largely internal. That changed in the second half of the 20th century. We now recognize that in recent centuries and millennia, most movements of communities and individuals have been local and shorter. Constant contact between communities resulted in features flowing across language boundaries, especially in crowded and long-settled locations such as most of Central and West Africa. Although communities did mix and people did cross borders, it became clear that language and linguistic features could also move without communities moving.

Assessing the Development of Operator Trust in Automation: A Longitudinal Study of an Autonomous Campus Shuttle

2020 ◽  
Vol 64 (1) ◽  
pp. 1421-1425
Author(s):  
Margaret Fowler ◽  
Farzan Sasangohar ◽  
Bob Brydia
Keyword(s):  
Longitudinal Study ◽  
Significant Relationship ◽  
Autonomous Vehicle ◽  
Student Population ◽  
Tier 1 ◽  
Trust In Automation ◽  
Operational Issues ◽  
The Relationship ◽  
Over Time

A large public tier-1 university hosted an autonomous vehicle on campus for a 12-week demonstration. Throughout the deployment, the vehicle was operated autonomously and used 5 safety operators from the student population to take over shuttle operations, as necessary. Daily and weekly surveys as well as pre-and post-study interviews were used to investigate how operators’ trust developed and changed over time as well as the relationship between trust and operational issues that varied in severity. Results revealed that there was not a significant relationship between trust and severity of operational issues. Trust levels appeared to remain relatively consistent before, during and after the deployment.

An Analytical Study of the Folk Musical Instruments of Meghalaya

2021 ◽  
Vol 66 (1) ◽  
pp. 23-38
Author(s):  
Joyanta Sarkar ◽  
Anil Rai
Keyword(s):  
20Th Century ◽  
Folk Music ◽  
Analytical Study ◽  
Musical Instrument ◽  
Folk Songs ◽  
Musical Instruments ◽  
Indian State ◽  
Material Benefits ◽  
Local Materials ◽  
Over Time

"Meghalaya is a richly inhabited Indian state. Drums, flutes of bamboo and hand-held small cymbals are a common ensemble. The advent of Christianity in the middle of the 20th century marked the start of a decline in tribal popular music. Over time, Meghalaya’s music scene has evolved, attracting many talented artists and bands from both traditional and not-so traditional genres. Any of the most recent Meghalaya musicians and bands is: The Plague Throat, Kerios Wahlang, Cryptographik Street Poets, etc., Soulmate, Lou Majaw, and Snow White. Meghalaya’s music is characterised by traditional instruments and folk songs. The Musical Instruments of Meghalaya are made from local materials. Meghalayan people honour powerful natural forces and aim to pacify animistic spirits and local gods. The instruments are made of bamboo, flesh, wood, and animal horn. Any one of these musical instruments is considered to have the ability to offer material benefits. The Meghalaya musical instrument is an essential part of traditional folk music in the region. In this article, we offer an overview of the folk musical instruments of Meghalaya. Keywords: Idiophone, Aerophone, Chordophone, Membranophone, Trumpet. "

Historical and logical analysis of research on the development of professional value orientations of students in the context of Internet socialization

2020 ◽  
pp. 7-14
Author(s):  
Marina S. Chvanova ◽  
Irina A. Kiselyova
Keyword(s):  
Young People ◽  
20Th Century ◽  
Value Orientations ◽  
Logical Analysis ◽  
Early 20Th Century ◽  
Logical Sequence ◽  
Characteristic Features ◽  
Over Time ◽  
Professional Value

We examine the formation of the concept of “value orientations”, “professional value orientations of students”. The classification is presented taking into account the following profes-sional value orientations: “professional and personal”, “professional and group”, “social and pro-fessional”. Professional value orientations are analyzed taking into account their importance, with subdivision into instrumental and terminal ones. We consider the development of professional value orientations in a historical and logical sequence with a change of stages, with characteristic features, taking into account the presented classification. The following periods are considered: the second half of the 19th – early 20th century, 20–40s of the 20th century, 50–60s of the 20th century, 60–80s of the 20th century, 80–90s of the 20th century, 21th century. The characteristic features of the stage, the means of influencing the value orientations of young people, are analyzed, which made it possible to identify the transformation of professional value orientations over time, including in the context of Internet socialization.

scholarly journals The Birth and Death of the Russian House in the Priargun’ie Three Rivers Region, People’s Republic of China (1)

Folklorica ◽  
2015 ◽  
Vol 18 ◽  
Author(s):  
Vladimir Klyaus
Keyword(s):  
20Th Century ◽  
19Th Century ◽  
Early 20Th Century ◽  
Traditional Practices ◽  
Soviet Rule ◽  
Late 19Th Century ◽  
Republic Of China ◽  
Three Rivers Region ◽  
Three Rivers ◽  
Over Time

This article considers the remnants of Russian ritual practices surrounding houses in the Priangun’ie region of China. This region was populated by Russians from the late 19th century on. A large group of immigrants (Russian, Tungus and Buriat) immigrated there from the Transbaikal region of Russia after the establishment of Soviet rule in the early 20th century. The paper examines what remains of Russian traditional practices, how they have been blended with native Chinese traditions, and adapted over time to reflect intermarriage between people of Chinese or Tungus and Russian descent.

scholarly journals Cartographic depiction of religious buildings and cemeteries on cadastral maps created during the first cadastral survey of Bosnia and Herzegovina

Geoadria ◽  
2015 ◽  
Vol 20 (2) ◽  
Author(s):  
Nedim Tuno ◽  
Jusuf Topoljak ◽  
Admir Mulahusić ◽  
Mithad Kozličić
Keyword(s):  
20Th Century ◽  
Bosnia And Herzegovina ◽  
Religious Communities ◽  
Early 20Th Century ◽  
Religious Buildings ◽  
Cadastral Maps ◽  
Archival Documents ◽  
Over Time

This paper deals with cartographic depictions of religious facilities and cemeteries in Bosnia and Herzegovina on cadastral maps created during the Austro-Hungarian administration. It shows how cartographic depictions of these plans changed over time, based on collections of topographic symbols published in the late 19th and the early 20th century. Relevant cartographic sources depicting religious buildings were identified and collected through analysis of genuine archival documents, i.e. relevant cartographical sources of different scales and types. The research of the materials resulted in a scientific description of the most important aspects of religious facilities belonging to different religious communities in Bosnia and Herzegovina.

Abstract 122: Compression-Induced Ventilation Volumes Decrease with Chest Compression Depth and Prolonged CPR

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Simone Ordelman ◽  
Paul Aelen ◽  
Paul van Berkom ◽  
Gerrit J Noordergraaf
Keyword(s):  
Gas Exchange ◽  
Endotracheal Tube ◽  
Chest Compression ◽  
Minute Ventilation ◽  
Time Effect ◽  
Chest Compressions ◽  
Initial Value ◽  
Compression Depth ◽  
Minute Period ◽  
Over Time

Introduction: Compression-induced ventilation may aid gas exchange during CPR. We hypothesized that the amount of gas moving in and out of the lungs depends on chest compression depth. Methods: VF was induced in five female, anesthetized and intubated pigs of about 30 kg. After 30 seconds of non-intervention time, chest compressions were started and maintained at a rate of 100 compressions per minute. Every two minutes chest compression depth was altered, resulting in 14 minutes of CPR with a depth sequence of 4 cm, 3 cm, 4 cm, 5 cm, 5.5 cm, 5 cm and 4 cm. Ventilations were performed manually with a bag-valve device 10 times per minute during continuous chest compressions by a dedicated expert. Airway flow was measured at the end of the endotracheal tube. Compression-induced ventilation was determined from the periods between the manual ventilations. The average compression-induced minute ventilation volume was determined over the last minute of each two minute period of CPR at each specific chest compression depth. Results: The compression-induced ventilation volume in the first period of CPR at 4 cm of depth was 1.6 ± 0.9 L/min (about 4% of total ventilation volume). The figure shows how the compression-induced ventilation volume decreases with increasing chest compression depth, relative to this initial value. CPR with a chest compression depth of 4 cm was performed three times in each pig, and the corresponding compression-induced ventilation volumes decreased with time. This suggested that there might be just a time effect (e.g. atelectasis). However, the final compression depth of 4 cm resulted in larger compression-induced ventilation volumes than the preceding 5 cm and 5.5 cm compression depths, indicating that the decreased volume over time could not purely be a time effect, but must also be an effect of the depth. Conclusion: In conclusion, compression-induced ventilation volume appears to decrease with deeper chest compressions as well as with prolonged CPR.

Djalkiri

2021 ◽  
Keyword(s):  
20Th Century ◽  
Early 20Th Century ◽  
Philosophical Foundations ◽  
Collaborative Community ◽  
Arnhem Land ◽  
New Type ◽  
The University ◽  
The Relationship ◽  
Over Time

Djalkiri are “footprints" – ancestral imprints on the landscape that provide the Yolŋu people of eastern Arnhem Land with their philosophical foundations. This book describes how Yolŋu artists and communities keep these foundations strong, and how they have worked with museums to develop a collaborative, community-led approach to the collection and display of their artwork. It includes contributions from Yolŋu elders and artists as well as Indigenous and non-Indigenous historians and curators. Together they explore how the relationship between communities and museums has changed over time. From the early 20th century, anthropologists and other collectors acquired artworks and objects and took photographs in Arnhem Land that became part of collections at the University of Sydney. Later generations of Yolŋu have sought out these materials and, with museum curators, proposed a new type of relationship, based on a deeper respect for Yolŋu intellectual frameworks and a commitment to their central role in curation. This book tells some of their stories.

The Theoretical Foundations and Historical Development of Interdisciplinarity

2017 ◽  
pp. 1-13
Author(s):  
Mohammed Nasser Al-Suqri ◽  
Salim Said AlKindi
Keyword(s):  
20Th Century ◽  
Historical Development ◽  
Early 20Th Century ◽  
Theoretical Understanding ◽  
Research And Education ◽  
Theoretical Foundations ◽  
Over Time

The concept of interdisciplinarity has a long history but interpretations of this term and the importance of interdisciplinarity in research and education have varied over time. This chapter traces the theoretical understanding and historical development of interdisciplinarity to provide background and context for the book. First it examines the ways in which interdisciplinarity and similar phenomena have been conceptualized in the literature. A roughly chronological account of the main theoretical and empirical developments in interdisciplinarity is then set out, divided into three main periods dating from the early 20th century to the present day.

Propaganda

2018 ◽  
Author(s):  
David Beard
Keyword(s):  
Public Relations ◽  
20Th Century ◽  
Political Communication ◽  
Democratic Society ◽  
Political Organizations ◽  
Distorted Communication ◽  
The Masses ◽  
Over Time

Propaganda is the term for a variety of communication phenomena developed in the 20th century. As such, its meaning has changed over time from a largely neutral description of public relations and political communication towards an account of systematically distorted communication. The earliest major American proponent of the term, Edward Bernays (1891–1995), claimed that the ‘conscious and intelligent manipulation of the organized habits and opinions of the masses is an important element in democratic society’ (Bernays, 1928: 1). Bernays believed that ‘propaganda’, for him, a political variation on public relations work, was a tool used by political organizations and eventually businesses to organize and manipulate the desires, actions and will of the masses.

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