bluuebunny/crossref_metadata_2025 huggingface dataset:
Tanguy, Yves (1900–1955)
Authors: Atkin Will
Published: September 2018

Yves Tanguy was a French painter and one of the principal members of the Surrealist group. His main artistic output consisted of oil paintings, which were characterized by abstract forms rendered three-dimensionally and set in elusive recessional space. His manner of painting was devised according to the Surrealist concept of automatism. Tanguy is well known for his contributions to numerous "exquisite corpse" drawings made collectively with other Surrealists and also for his work based on the concept of the Surrealist Objet [Object] in the mid 1930s. Over many years, he was a regular illustrator for Surrealist publications, including works by André Breton, Benjamin Péret, and in the Surrealist journal Minotaure. During World War II in the early 1940s, Tanguy played a crucial role in bringing the Surrealist group to New York, an exodus that is perceived in the history of modernism as consequential to the development of Abstract Expressionism and the American school of modernist painting. During this period of activity in New York, the formal qualities of particular Surrealist paintings, such as the abstract works of Tanguy and Roberto Matta, proved inspirational for certain Abstract Expressionists’ formal explorations of color, medium, perception, and sensation.
To Ngoc Van (1906–1954)
Authors: Scott Phoebe
Published: September 2018

To Ngoc Van was a notable Vietnamese painter, and one of the first generation of students to graduate from the École des Beaux Arts de l’Indochine, Hanoi, founded in 1925. He was known primarily for his works in oil, which captured the romantic subjects popular in Vietnamese painting of the 1930s and 1940s. As one of the first Vietnamese artists to write and publish art criticism in the local press, he was also influential in shaping the public discourse around Vietnamese modern art. Like many other intellectuals of his generation, he lived through the transition from the colonial period to the anti-colonial, Communist-led revolution, and consequently had to make profound changes to his ideas and practices. During the First Indochina War (1946–1954), he transformed his manner of painting to suit the new ideological environment, creating propaganda works to boost morale, as well as images of peasants and soldiers. However, he was still a strong advocate for the visual arts, and published passionate defenses of creative freedom, artistic education and the practice of modern Vietnamese lacquer painting, despite the ideological pressures of the period.
Wenger, Susanne (1915–2009)
Authors: Probst Peter
Published: September 2018

Susanne Wenger was an Austrian artist and an instrumental figure in the history of Nigerian modernism. Born on July 4, 1915 in the city of Graz, Austria, Wenger first attended the local School of Applied Arts before she moved to Vienna to continue her art education, first at the School of Graphic Design and then, from 1933 to 1935, at the Academy of Art. Like other students, Wenger’s interest was in contemporary post-secessionist movements. The few works remaining from Wenger’s Viennese phase exemplify different styles ranging from pencil studies of plants and animal bodies, executed with an almost photographic precision, to expressionistic and cubist paintings, to surrealist crayon drawings. After the war she moved from Vienna to Paris, where she met editor Ulli Beier (1922–2011). The encounter with Beier marked a profound and lasting shift in Wenger’s life. The two fell in love and decided to spend the next years in Nigeria, where he got a job as a lecturer at the University of Ibandan. What they thought would be an adventure became a confrontation with the colonial reality. The colonial curriculum had an exclusive focus on Western history and culture. Interaction between Nigerians and members of the British faculty hardly existed. While Beier reacted to the colonial reality by seeking refuge in the newly established extramural department, which allowed him to work outside the campus, Wenger’s response was more private and personal. After a severe illness, she embarked on a journey—both spiritual and artistic—which resulted in the so-called "Osogbo experiment."
Adams, Ansel Easton (1902–1984)
Authors: Slipp Naomi
Published: September 2018

Ansel Adams is known for his technically precise, large format photographs of the American western landscape. Self-taught, his father gave him a camera on a 1916 family trip to Yosemite National Park. One year later, he joined the Sierra Club. His life-long environmental activism led to the federal protection of Yosemite. Adams took one of his most famous photographs, Moonrise, Hernandez, New Mexico, in 1941 while photographing national parks for the Department of the Interior. Adams’s early solo exhibitions include the Smithsonian Institution in 1931, followed by a 1936 exhibition at Alfred Stieglitz’s New York gallery, An American Place. Co-founder of f/64, a group dedicated to straight photography, which eschewed manipulation in favour of objectivity, Adams established the Zone System, a method of teaching photographic exposure for precise tonal range. He also authored articles and guides, including Making a Photograph in 1935, and co-founded the photography magazine Aperture in 1952. Creator of the photography department at the California School of Fine Arts and co-founder of the Centre for Creative Photography, Adams was awarded the Presidential Medal of Freedom in 1980 and died in Monterey, California in 1984.
Ballets Russes
Authors: Parton Anthony
Published: September 2018

Founded by the Russian impressario Sergei Diaghilev in 1909, the Ballets Russes played a role of fundamental importance in the development of early twentieth-century modernism. In the course of its twenty-year history, Diaghilev employed the most exciting and forward-thinking artists, composers and choreographers of the time to create over 100 ballets which not only revolutionized the language of dance and reformulated the role of the performing arts by bring modernism onto the stage but also charted a new step forward in inter-disciplinary creation, using the medium of ballet to bring to fruition Richard Wagner’s concept of the Gesamtkunstwerk (‘total art work’).
Cocteau, Jean (1889–1963)
Authors: Leskosky Richard J.
Published: September 2018

Jean Cocteau (Jean Maurice Eugène Clément Cocteau) was an influential, prolific, multi-talented French artist, writer, critic and filmmaker. He wrote poetry, plays, libretti for ballets, journals, and screenplays; he adapted his own and others’ writing for the stage and screen. He illustrated books, painted, created mosaics, tapestries, and stained glass windows, and designed sets and costumes. He also occasionally appeared on stage and in films and starred (essentially playing himself) in his last film Le Testament d’Orphée [The Testament of Orpheus] (1960). Outside France, Cocteau remains best known for his films and for his plays, which regularly continue to be staged around the world.

Cocteau was born in Maisons-Lafitte, France, on July 5, 1889, to a wealthy, art-conscious family and began to attract attention with his poetry in his late teens. He was friends with and collaborated creatively with the most prominent artists of his time. Pablo Picasso, Amedeo Modigliani, and photographer Man Ray, for example, all did portraits of him. It was to a young Cocteau in 1912 that ballet impresario Sergei Diaghilev issued his famous challenge, ‘Etonne-moi!’ [‘Astonish me!’].
Hamsun, Knut (1859–1952)
Authors: Krouk Dean
Published: September 2018

Norwegian writer Knut Hamsun’s novels anticipated modernist psychological fiction and influenced a generation of major European figures. Winner of the 1920 Nobel Prize in literature, Hamsun wrote over thirty works in various genres, including both experimental modernist and neorealist novels. In the final decades of his life, Hamsun became a Nazi sympathizer during the German occupation of Norway, which has complicated his literary legacy.

Hamsun was born as Knut Pedersen in central Norway in 1859, but moved to the coastal north of the country while very young. He grew up with little formal education, writing his first works of imaginative fiction in the late 1870s. Hamsun made two extended stays in the USA in the 1880s, when he worked on farms and gave lectures about contemporary European and Scandinavian literature.
Duchamp, Marcel (1887-1968)
Authors: Gee Malcolm , Amit Rea
Published: September 2018

Duchamp was one of the most influential and original artists of the 20th century. He rejected the constraints of painting and believed (both as an intellectual and in his material practice) that contemporary art should reconnect with its history in a radical, transgressive manner. La Mariée mise à nu par ses célibataires, même (The Bride Stripped Bare by her Bachelors, Even—‘The Large Glass’) (1915–1923) exemplified the complexity and daring of his ideas, which were re-revealed in his striking last work Étant Donnés (1946–1966), a secret installation that was only made public after his death. His concept of the ‘Readymade’ defied established notions of authorship and contributed to the opening up of the field of art later associated with postmodernism.
Eliot, Thomas Stearns (1888–1965)
Authors: Templeton Erin
Published: September 2018

Thomas Stearns Eliot (1888–1965) was an essayist, editor, playwright, poet, and publisher. He was awarded the Nobel Prize in Literature in 1948. He is perhaps best known for his long poem The Waste Land.

Eliot was born in St. Louis, Missouri and attended Harvard University, where he earned his bachelor’s degree in philosophy. Eliot’s postgraduate studies in philosophy took him to the Sorbonne in 1910/11 and to Oxford in 1914. Once he arrived in England, however, he spent much of his time in London. There he met two of the most influential people of his literary life: the American poet Ezra Pound and a young Englishwoman named Vivienne Haigh-Wood, whom Eliot would marry in 1915 after a four-month courtship. Pound encouraged Eliot, who had been planning an academic career, to keep writing poetry and to submit "The Love Song of J. Alfred Prufrock" to Poetry magazine for publication. In addition to writing poetry, Eliot also took a position with Lloyd’s Bank in 1917, managing foreign accounts. Pound and Eliot frequently collaborated and critiqued each other’s work throughout the 1920s and 1930s and remained friends until Eliot’s death, despite divergent political and religious paths. The most famous of these collaborations, The Waste Land, has been documented in a published facsimile edition of the poem (1972) that reveals Pound’s numerous comments on Eliot’s manuscript. The Waste Land is revolutionary both in its form, free verse, and its subject matter, which links urbanization, technology, sexuality, and post-war alienation to dozens of classical allusions in seven languages. The poem is a pastiche of voices and fragments linked both thematically and tonally.
Ellington, Duke (1899–1974)
Authors: Garlitz Dustin
Published: September 2018

Duke Ellington was an American jazz composer, pianist, and big-band leader who authored over 1,000 compositions throughout his career. Having studied piano since the age of seven, Ellington relocated to New York City as part of the Great Migration and became a prominent musical figure in the Harlem Renaissance. He recorded full-length studio albums in quartet and trio settings with high modernists John Coltrane and Charles Mingus. Ellington was posthumously awarded a Pulitzer Prize Special Citation on the centennial of his birth in 1999, recognising his musical genius, his evocation of the principles of democracy through jazz, and his significant contributions to modern culture and the arts. Giddins and DeVeaux (2009) argue that Ellington’s compositions have been the most performed pieces in jazz written by any one composer.
Gauguin, Paul (1848-1903)
Authors: Atkin Will
Published: September 2018

Paul Gauguin was a Parisian-born French artist who was for a time associated with the Neo-Impressionist and Symbolist movements in painting. Having turned to a career as an artist relatively late, after working as a stockbroker, he became a remarkable presence within the French avant-garde. His activities as an artist fall, broadly, into two professional phases. The first phase of Gauguin’s career is characterized by his work in France up until 1891. During this early part of his career, he became closely linked to the Neo-Impressionist circle and learned his technical practice from painters such as Camille Pissaro (1830–1903). Later on in this period, he famously became acquainted with Vincent van Gogh (1853–1890) in a tumultuous and short-lived professional relationship. Towards the end of this phase of activity in France, he became involved with the Symbolist movement through his friendship with the poet Charles Morice (1860–1919). The second phase of Gauguin’s career is characterized by his activities in French Polynesia, where, from 1891 until his death in 1903, he sought to develop a primitivist approach to art based on Polynesian traditions. During this later period, he also produced a significant body of writing on art and his travels.
Ernest Hemingway
Authors: Moddelmog Debra
Published: September 2018

Ernest Hemingway (1899-1961) was an American writer who burst onto the modernist literary scene in Paris during the 1920s and subsequently became one of the most famous authors of the twentieth century. He developed a minimalist style characterized by an emotionally detached point of view, understated irony, the omission of key information from the story’s telling, and the conveyance of psychological states through exterior details. Although this style was frequently imitated and parodied, Hemingway actually experimented with style and narrative form throughout his career, for example using more complex sentence structures and forms (such as in his unfinished land-sea-air trilogy) in his later work.
Kafka, Franz (1883–1924)
Authors: Langlois Christopher
Published: September 2018

Franz Kafka was born 3 July 1883 to a bourgeois family in Prague, the Czech capital that in the late nineteenth century belonged to the Austro-Hungarian Empire. Although his nationality was therefore Austro-Hungarian, Kafka’s parents, Hermann Kafka and Julie Lowy were Jewish, and under the reign of Franz Josef I, Austrian Jews were widely regarded as second-class citizens. As head of a Jewish family growing up in Czech-speaking Prague, Hermann Kafka strongly insisted that his children be raised to speak and act German, the de facto language and identity of social and cultural prestige in Prague during this period. While Kafka exhibited a keen interest in literature and art from a very young age, his notoriously overbearing father was insistent that he should receive education and training for a professional or administrative career, which would allow him to provide his future family with the same level of upper-middle class affluence that Hermann had provided for Franz. Kafka reluctantly capitulated, and on 18 June 1906 he successfully completed a Doctorate in Law from the Ferdinand-Karls University in Prague.
Wassily Kandinsky (1866-1944)
Authors: Washton Long Rose Carol
Published: September 2018

Kandinsky’s commitment to abstraction in painting and theory has attracted the attention of artists and critics throughout the twentieth century. His major manifesto Über des Geistige in der Kunst [On the Spiritual in Art], which described abstraction as a stimulus to a new world order, went through three editions by March of 1912. This publication as well as the establishment with the painter Franz Marc of the exhibition group and yearbook Der Blaue Reiter in 1911, insured the fame of his large-sized and vividly colored oils, some bearing titles such as Composition and Improvisation to emphasize the relation of painting with music, then thought to be the least representational and thus the most ideal of all the arts.

Like other artists and writers of his generation who had absorbed symbolist, theosophical, and anarchist beliefs, Kandinsky felt that he had to engage his audience in a struggle to understand his painting in order to lead them to a greater awareness of the cosmic orders. Naturalism was too descriptive of the physical world, but in 1912 he did not believe that his audience, and even others artists, were ready for abstraction.
Pavlova, Anna (1881-1931)
Authors: Casey Carrie Gaiser
Published: September 2018

Considered the most expressively gifted ballerina of her generation, Russian dancer Anna Pavlova introduced ballet to a world audience through 23 years of nearly constant touring. Pavlova’s talent resided in her ability to convey subjective and emotional experience through conventional ballet material, rather than in avant-garde experimentation. While the themes of her ballets pegged her as a traditionalist, Pavlova’s career mirrored forward-thinking trends in dance through her embrace of a freer style, her commitment to popularising ballet worldwide and her experiments with dances from other cultures.
The Great War (1914–1918)
Authors: Frayn Andrew , Sheehan Paul
Published: September 2018

The Great War was fought from 1914 to 1918, and was officially ended in 1919 by the Treaty of Versailles. Its primary locus was the trench war on the Western Front between the Entente Powers (the British, French, and Russian empires, the US from 1917, and many other nations) and the Central Powers (the German, Austro-Hungarian, and Ottoman empires and Bulgaria). By the time the armistice was signed at Compiègne, at 11 a.m on November 11, 1918, almost nine million combatants had been killed. It was the first truly global war, whose modernity was felt in its scale, technology, and the corresponding speed with which events could be reported. The impact of the war was unavoidable in Europe and was felt in literature at the levels of content and form, in modernist prose and poetry, by men and women, combatants and civilians.
Sartre, Jean-Paul (1905–1980)
Authors: Koenig Raphael , Vial Caroline
Published: September 2018

Jean-Paul Sartre was a French philosopher, left-wing political activist, playwright, and novelist. One of the leading French public intellectuals of the twentieth century, he was a key figure in the intellectual field in the decade following the Second World War. Influenced by Edmund Husserl, Martin Heidegger, and Marxism, he was a major theorist of existentialism. For Sartre, human nature is not a given but derives from personal choice. Based on ontological reflection, Sartre’s existentialism thus leads to the practical realm of ethics and politics by laying emphasis on the moral responsibility of the individual cut off from the thing-in-itself and condemned to be free.
Collins, Janet (1917–2003)
Authors: Lewin Yaël
Published: September 2018

Magical on stage, elusive off stage, Janet Collins was an enigmatic and complex presence in twentieth-century dance. As the first full-time African American ballerina at the Metropolitan Opera in 1951, she broke the color barrier and generated international headlines—no small feat in an era when racial tension and discrimination continued to prevail. This celebrated achievement placed her in the pantheon of pioneering African Americans and became the triumph for which she was most remembered. Yet Collins also succeeded as a unique concert dance soloist and choreographer, fusing disparate techniques and influences in her creations—an approach that was in keeping with modernist experimentations and set her apart from many of her dancing peers. As a result of these dual identities, she serves as a pivotal figure in the lineage of African American cultural history, and as one of the distinguished women of her generation who helped propel the evolution of American dance.
Degradation Kinetics and Secondary Organic Aerosol Formation from Eugenol by Hydroxyl Radicals
Authors: Liu Changgeng , Liu Yongchun , Chen Tianzeng , Liu Jun , He Hong
Published: September 2018

Abstract. Methoxyphenols are an important organic component of wood-burning emissions and considered to be potential precursors of secondary organic aerosols (SOA). In this work, the rate constant and SOA formation potential for the OH-initiated reaction of 4-allyl-2-methoxyphenol (eugenol) were investigated for the first time in an oxidation flow reactor (OFR). The rate constant was (8.01 ± 0.40) × 10−11 cm3 molecule−1 s−1 as determined by the relative rate method. The SOA yield first increased and then decreased as a function of OH exposure, and was also dependent on eugenol concentration. The maximum SOA yields (0.11–0.31) obtained at different eugenol concentrations could be expressed well by an one-product model. The carbon oxidation state (OSC) increased linearly and significantly as OH exposure rose, indicating that a high oxidation degree was achieved for SOA. In addition, the presence of SO2 (0–198 ppbv) and NO2 (0–109 ppbv) was conducive to increasing SOA yield, for which the maximum enhancement values were 38.57 % and 19.17 %, respectively. The N / C ratio (0.032–0.043) indicated that NO2 participated in the OH-initiated reaction, subsequently forming organic nitrates. The results could be helpful for further understanding the SOA formation potential from the atmospheric oxidation of methoxyphenols and the atmospheric aging process of smoke plumes from biomass-burning emissions.
First Measurement of Atmospheric Mercury Species in Qomolangma Nature
Preserve, Tibetan Plateau, and Evidence of Transboundary Pollutant Invasion
Authors: Lin Huiming , Tong Yindong , Yin Xiufeng , Zhang Qianggong , Zhang Hui , Zhang Haoran , Chen Long , Kang Shichang , Zhang Wei , Schauer James , de Foy Benjamin , Bu Xiaoge , Wang Xuejun
Published: September 2018

Abstract. Located in the world’s ‘Third Pole’ and a remote region connecting the Indian Ocean plate and the Eurasian plate, Qomolangma National Nature Preserve (QNNP) is an ideal region to study the long-range transport of atmospheric pollutants. In this study, gaseous elemental mercury (GEM), gaseous oxidized mercury (GOM) and particle-bound mercury (PBM) were continuously measured during the Indian monsoon transition period in QNNP. A slight increase in GEM concentration was observed from the period preceding the Indian Summer Monsoon (1.31±0.42 ng m−3) to the Indian Summer Monsoon period (1.44±0.36 ng m−3), while significant decreases were observed in GOM and PBM concentrations, decreasing from 35.2±18.7 to 19.1±11.0 pg m−3 and from 30.5±12.6 to 24.7±19.9 pg m−3, respectively. A unique daily pattern of GEM concentration in QNNP was observed, with a peak value before sunrise and a low value at noon. Unexpectedly, GOM concentrations (with a mean value of 21.3±13.5 pg m−3) in this region were considerably higher than the values in other clean or even polluted regions. A cluster analysis indicated that the air masses transported to QNNP changed significantly at different stages of the monsoon, and the major potential Hg sources shifted from north India and west Nepal to east Nepal and Bangladesh. With large coverage of glacier in QNNP, local glacier winds could enforce the transboundary transport of pollutants and transport the polluted air masses to the Tibetan Plateau. It should be noted that the atmospheric Hg concentrations in QNNP are higher than the reported values in some background regions, which addresses the need for a more specific identification of Hg sources in QNNP and the importance of international cooperation for global Hg controls.
Characterization of flow recirculation zones in complex terrain using multi-lidar measurements
Authors: Menke Robert , Vasiljević Nikola , Mann Jakob , Lundquist Julie K.
Published: September 2018

Abstract. Because flow recirculation can generate significant amounts of turbulence, it can impact the success of wind energy projects. This study uses unique Doppler lidar observations to quantify occurrences of flow recirculation on lee sides of ridges. An extensive dataset of observations of flow over complex terrain is available from the Perdigão-2017 field campaign over a period of three months. The campaign site was selected because of the unique terrain feature of two nearly parallel ridges with a valley-to-ridge-top height difference of about 200 m and a ridge-to-ridge distance of 1.4 km. Six scanning Doppler lidars probed the flow field in several vertical planes orthogonal to the ridges using range-height-indicator scans. With this lidar setup, we achieved vertical scans of the recirculation zone at three positions along two parallel ridges. We construct a method to identify flow recirculation zones in the scans, as well as define characteristics of these zones. According to our data analysis, flow recirculation, with reverse flow wind speeds greater than 0.5 m s−1, occurs over 50 % of the time when the wind direction is perpendicular to the direction of the ridges. Atmospheric conditions, such as atmospheric stability and wind speed, affect the occurrence of flow recirculation. Flow recirculation occurs more frequently during periods with wind speeds above 8 m s−1. Recirculation within the valley affects the mean wind and turbulence fields at turbine heights on the downwind ridge in magnitudes significant for wind resource assessment.
The North Sea surge of 31 October–1 November 2006 during Storm Britta
Authors: Kettle Anthony James
Published: September 2018

Abstract. Offshore energy infrastructure, including the petroleum and wind energy
sectors, are susceptible to damage and interruption by extreme meteorological
events. In northwest Europe and especially the North Sea, these extreme
meteorological events are mostly associated with severe storms in the autumn
and winter seasons. In the North Sea, storm surges have an impact on the
offshore energy sector mainly from the flooding of port facilities and from
strong ocean currents causing extra structural loading and bottom scouring.
Storm Britta on 31 October–1 November 2006 was an important North Sea storm
with a high surge along the coast of the Netherlands and Germany and a
significant number of high wave reports. The paper presents an analysis of
the national tide gauge records of the United Kingdom, the Netherlands,
Germany, and Denmark to spectrally isolate and reconstruct time series
components corresponding to the storm surge, semi-diurnal tide, and short
period contribution. The semi-diurnal tides and storm surge during Storm
Britta are tracked counter-clockwise around the North Sea from Scotland to
northern Denmark. The storm surge was remarkable for its pronounced peak in
the coastal area between the Netherlands and Germany with no precedent in the
∼100 year measurement record. The short period component of the tide
gauge records show large oscillations during the height of the storm that may
correspond with reports of unusually high waves at nearby coastal locations.
Advancements in the Aerosol Robotic Network (AERONET) Version 3 Database – Automated Near Real-Time Quality Control Algorithm with Improved Cloud Screening for Sun Photometer Aerosol Optical Depth (AOD) Measurements
Authors: Giles David M. , Sinyuk Alexander , Sorokin Mikhail S. , Schafer Joel S. , Smirnov Alexander , Slutsker Ilya , Eck Thomas F. , Holben Brent N. , Lewis Jasper , Campbell James , Welton Ellsworth J. , Korkin Sergey , Lyapustin Alexei
Published: September 2018

Abstract. The Aerosol Robotic Network (AERONET) provides highly accurate, ground-truth measurements of the aerosol optical depth (AOD) using Cimel Electronique Sun/Sky radiometers for more than 25 years. In Version 2 (V2) of the AERONET database, the near real-time AOD was semi-automatically quality controlled utilizing mainly cloud screening methodology, while additional AOD data contaminated by clouds or affected by instrument anomalies were removed manually before attaining quality assured status (Level 2.0). The large growth in the number of AERONET sites over the past 25 years resulted in significant burden to manually quality control millions of measurements in a consistent manner. The AERONET Version 3 (V3) algorithm provides fully automatic cloud screening and instrument anomaly quality controls. All of these new algorithm updates apply to near real-time data as well as post-field deployment processed data, and AERONET reprocessed the database in 2018. A full algorithm redevelopment provided the opportunity to improve data inputs and corrections such as unique filter specific temperature characterizations for all visible and near-infrared wavelengths, updated gaseous and water vapor absorption coefficients, and ancillary data sets. The Level 2.0 AOD quality assured data set is now available within a month after post-field calibration, reducing the lag time from up to several months. Near real-time estimated uncertainty is determined using data qualified as V3 Level 2.0 AOD and considering the difference between the AOD computed with the pre-field calibration and AOD computed with pre-field and post-field calibration. This assessment provides a near real-time uncertainty estimate where average differences of AOD suggest a +0.02 bias and one sigma uncertainty of 0.02, spectrally, but the bias and uncertainty can be significantly larger for specific instrument deployments. Long-term monthly averages analyzed for the entire V3 and V2 databases produced average differences (V3–V2) of +0.002 with a ±0.02 standard deviation, yet monthly averages calculated using time-matched observations in both databases were analyzed to compute an average difference of −0.002 with a ±0.004 standard deviation. The high statistical agreement in multi-year monthly averaged AOD validates the advanced automatic data quality control algorithms and suggests that migrating research to the V3 database will corroborate most V2 research conclusions and likely lead to more accurate results in some cases.
Trends in the atmospheric water vapour estimated
from GPS data for different elevation cutoff angles
Authors: Ning Tong , Elgered Gunnar
Published: September 2018

Abstract. We have processed 20 years of GPS data from 8 sites in Sweden and 5 sites in Finland, using two different elevation cutoff angles 10° and 25°, to estimate the atmospheric integrated water vapour (IWV). We have also tested three additional elevation-angle-dependent parameters in the GPS data processing, i.e., (1) two different mapping functions, (2) with or without second order corrections for ionospheric effects, and (3) with or without elevation dependent data weighting. The results show that all these three parameters have insignificant impacts on the resulting linear IWV trends. We compared the GPS-derived IWV trends to the corresponding trends from radiosonde data at 7 nearby (
An improved low power measurement of ambient NO2 and O3 combining electrochemical sensor clusters and machine learning
Authors: Smith Kate R. , Edwards Peter M. , Ivatt Peter D. , Lee James D. , Squires Freya , Dai Chengliang , Peltier Richard E. , Evans Mat J. , Lewis Alastair C.
Published: September 2018

Abstract. Low cost sensors (LCS) are an appealing solution to the problem of spatial resolution in air quality measurement, but they currently do not have the same analytical performance as regulatory reference methods. Individual sensors can be susceptible to analytical cross interferences, have random signal variability and experience drift over short, medium and long timescales. To overcome some of the performance limitations of individual sensors we use a clustering approach using the instantaneous median signal from six identical electrochemical sensors to minimise the randomised drifts and inter-sensor differences. We report here a low power analytical device (
Sensitivity of GNSS tropospheric gradients to processing options
Authors: Kačmařík Michal , Douša Jan , Zus Florian , Václavovic Pavel , Balidakis Kyriakos , Dick Galina , Wickert Jens
Published: September 2018

Abstract. An analysis of processing settings impact on estimated tropospheric gradients is presented. The study is based on the benchmark data set collected within the COST GNSS4SWEC action with observations from 430 GNSS reference stations in central Europe for May and June 2013. Tropospheric gradients were estimated in eight different variants of GNSS data processing using Precise Point Positioning with the G-Nut/Tefnut software. The impact of the gradient mapping function, elevation cut-off angle, GNSS constellation and real-time versus post-processing mode were assessed by comparing the variants by each to other and by evaluating them with respect to tropospheric gradients derived from two numerical weather prediction models. Generally, all the solutions in the post-processing mode provided a robust tropospheric gradient estimation with a clear relation to real weather conditions. The quality of tropospheric gradient estimates in real-time mode mainly depends on the actual quality of the real-time orbits and clocks. Best results were achieved using the 3° elevation angle cut-off and a combined GPS + GLONASS constellation. Systematic effects of up to 0.3 mm were observed in estimated tropospheric gradients when using different gradient mapping functions which depend on the applied observation elevation-dependent weighting. While the latitudinal troposphere tilting causes a systematic difference in the north gradient component on a global scale, large local wet gradients pointing to a direction of increased humidity cause systematic differences in both gradient components depending on the gradient direction.
Optical flow models as an open benchmark for radar-based
precipitation nowcasting (rainymotion v0.1)
Authors: Ayzel Georgy , Heistermann Maik , Winterrath Tanja
Published: September 2018

Abstract. Quantitative precipitation nowcasting (QPN) has become an essential technique in various application contexts, such as early warning or urban sewage control. A common heuristic prediction approach is to track the motion of precipitation features from a sequence of weather radar images, and then to extrapolate that motion to the imminent future (minutes to hours), assuming that the intensity of the features remains constant (Lagrangian persistence). In that context, optical flow has become one of the most popular tracking techniques. Yet, the present landscape of computational QPN models still struggles with producing open software implementations. Focusing on this gap, we have developed and extensively benchmarked a stack of models based on different optical flow algorithms for the tracking step, and a set of parsimonious extrapolation procedures based on image warping and advection. We demonstrate that these models provide skillful predictions comparable with or even superior to state-of-the-art operational software. Our software library (rainymotion) for precipitation nowcasting is written in Python programming language, and openly available at GitHub (https://github.com/hydrogo/rainymotion). That way, the library may serve as a tool for providing fast, free and transparent solutions that could serve as a benchmark for further model development and hypothesis testing – a benchmark that is far more advanced than the conventional benchmark of Eulerian persistence commonly used in QPN verification experiments.
The onset of chaos in nonautonomous dissipative dynamical systems: a low-order ocean-model case study
Authors: Pierini Stefano , Chekroun Mickaël D. , Ghil Michael
Published: September 2018

Abstract. A four-dimensional nonlinear spectral ocean model is used
to study the transition to chaos induced by periodic forcing in systems that
are nonchaotic in the autonomous limit. The analysis relies on the
construction of the system's pullback attractors (PBAs) through ensemble
simulations, based on a large number of initial states in the remote past. A
preliminary analysis of the autonomous system is carried out by investigating
its bifurcation diagram, as well as by calculating a metric that measures the
mean distance between two initially nearby trajectories, along with the
system's entropy. We find that nonchaotic attractors can still exhibit
sensitive dependence on initial data over some time interval; this apparent
paradox is resolved by noting that the dependence only concerns the phase of
the periodic trajectories, and that it disappears once the latter have
converged onto the attractor. The periodically forced system, analyzed by the
same methods, yields periodic or chaotic PBAs depending on the periodic
forcing's amplitude ε. A new diagnostic method – based on the
cross-correlation between two initially nearby trajectories – is proposed
to characterize the transition between the two types of behavior. Transition
to chaos is found to occur abruptly at a critical value εc
and begins with the intermittent emergence of periodic oscillations with
distinct phases. The same diagnostic method is finally shown to be a useful
tool for autonomous and aperiodically forced systems as well.
Channel flow, tectonic overpressure, and exhumation of high-pressure rocks in the Greater Himalayas
Authors: Marques Fernando O. , Mandal Nibir , Ghosh Subhajit , Ranalli Giorgio , Bose Santanu
Published: September 2018

Abstract. The Himalayas are the archetype of continental collision, where a number of long-standing fundamental problems persist in the Greater Himalayan Sequence (GHS): (1) contemporaneous reverse and normal faulting, (2) inversion of metamorphic grade, (3) origin of high- (HP) and ultrahigh-pressure (UHP) rocks, (4) mode of ductile extrusion and exhumation of HP and UHP rocks close to the GHS hanging wall, (5) flow kinematics in the subduction channel, and (6) tectonic overpressure, here defined as TOP  = P∕PL where P is total (dynamic) pressure and PL is lithostatic pressure. In this study we couple Himalayan geodynamics to numerical simulations to show how one single model, upward-tapering channel (UTC) flow, can be used to find a unified explanation for the evidence. The UTC simulates a flat-ramp geometry of the main underthrust faults, as proposed for many sections across the Himalayan continental subduction. Based on the current knowledge of the Himalayan subduction channel geometry and geological/geophysical data, the simulations predict that a UTC can be responsible for high TOP ( > 2). TOP increases exponentially with a decrease in UTC mouth width, and with an increase in underthrusting velocity and channel viscosity. The highest overpressure occurs at depths  < −60 km, which, combined with the flow configuration in the UTC, forces HP and UHP rocks to exhume along the channel's hanging wall, as in the Himalayas. By matching the computed velocities and pressures with geological data, we constrain the GHS viscosity to be  ≤ 1021 Pa s, and the effective convergence (transpression) to a value  ≤ 10 %. Variations in channel dip over time may promote or inhibit exhumation (> or < 15°, respectively). Viscous deformable walls do not affect overpressure significantly enough for a viscosity contrast (viscosity walls to viscosity channel) of the order of 1000 or 100. TOP in a UTC, however, is only possible if the condition at the bottom boundary is no-outlet pressure; otherwise it behaves as a leaking boundary that cannot retain dynamic pressure. However, the cold, thick, and strong lithospheres forming the Indian and Eurasian plates are a good argument against a leaking bottom boundary in a flat-ramp geometry, and therefore it is possible for overpressure to reach high values in the GHS.
A simple improvement of a tip loss model for actuator disc and actuator line simulations
Authors: Pirrung Georg Raimund , van der Laan Maarten Paul
Published: September 2018

Abstract. The loading of a wind turbine decreases towards the blade tip due to the velocities induced by the tip vortex and due to the spanwise flow. This tip loss effect has to be taken into account when performing actuator disc simulations, where the single blades of the turbine are not modeled, and when performing actuator line simulations, where the resolution typically is not fine enough to properly resolve the tip vortex. A widely used method applies a factor on the axial and tangential loading of the turbine. This factor decreases when approaching the blade tip. It has been shown that the factor should be different for the axial and tangential loading of the turbine due to the rotation of the resulting force vector at the airfoil sections caused by the induced velocity. The present article contains the derivation of a simple correction for the tangential load factor that takes this rotation into account. The correction does not need any additional curve fitting but just depends on the local airfoil characteristics and angle of attack.
The Effectiveness of Online Stress Management Training Interventions: A Systematic Literature Review
Authors: Van Wingerden MBA MCC Jessica , Derks Daantje
Published: September 2018

The central aim of this systematic literature review study was to investigate the effectiveness of online stress management training interventions that aimed to improve employees’ well-being. The study focused both on the effectiveness of online stress management training interventions and the sustainability of the intervention effects over time. Within this literature review 18 intervention studies, conducted worldwide among 3085 participants between 2002 and 2017, were evaluated. Methodological quality was examined using the Mixed Methods Appraisal Tool (MATT). In general, the main outcomes showed that most of the interventions turned out to be effective in decreasing employees’ levels of stress. In addition, some of these studies also revealed sustainability of intervention effects over time. This suggests that online stress management interventions are a promising tool for organizations to foster employee well-being.
Quality Improvement and Time to Lift the Ban on Mobile Phones in Secondary Schools
Authors: Promise Zvavahera , Farai Chigora
Published: September 2018

This study was conducted over three months from March to May 2018, at a time when modern mobile phones possess various functions that are invaluable for learning, teaching and communication purposes. Whilst some countries with a quest to improve quality of education, have embraced the continuously evolving technological capacities of mobile phones for educational purposes, secondary school pupils in Zimbabwe are prohibited from using mobile phones in class as these are viewed to be disruptive rather than useful. This study investigated stakeholders’ perceptions of potential utilisation of cell phones by secondary school students as learning tools that enhance quality of education. The sample included 15 secondary schools in Mazowe District. From these, the District Education Officials, headmasters, teachers, pupils and parents were given questionnaires to complete. Validation interviews were conducted for triangulation purposes. The findings revealed strong positive responses in favour of allowing the utilisation of mobile phones as learning tools in Zimbabwean secondary schools although some challenges in the implementation process were cited. These included possibilities of: student distraction in class; cheating; inappropriate video recording of class events and the publication of captured material on social platforms which could be harmful to other learners and the school. The issue of cost of data also came up. The study recommended the removal of the blanket ban on the use of mobile phones; instead, school authorities were encouraged to focus on developing strategies for addressing the implementation challenges cited. It is also critical to make sure that accessible cheap data be made available to learners in secondary schools. Schools in Zimbabwe should form networks so that cheap data is made available by sharing the networks. Schools in Zimbabwe, like institutions of higher learning, are encouraged to embrace the National Research and Education Network (NREN) concept which specialises in internet service provision dedicated to supporting the needs of education in Zimbabwe.
La investigación científica en Honduras desde los ámbitos económico, educativo y de salud en el periodo 1980-2015: una caracterización
Authors: Medina Edwin , Cárcamo Pérez Anayensy , Vaquedano Arely
Published: September 2018

Este artículo plantea reunir las tendencias sobre la discusión actual de la investigación científica dentro del sector económico, educativo y salud en Honduras (1980-2015), generando una visión más amplia, no sólo como práctica académica a nivel de universidades e instituciones aisladas o como un simple enfoque teórico o paradigmático, sino como una práctica social en la que los investigadores y las instituciones asuman la investigación científica como un medio de contribuir al desarrollo del país mediante planteamientos propios de gestión del desarrollo, de introducir cambios encaminados a mejorar el sistema y a la aplicación de los conocimientos para transformar la realidad. Además de la caracterización de las investigaciones en estas tres áreas, se cuenta con las valoraciones de varios expertos en cada área, lo que permite un análisis del impacto que esta ha tenido, sus fortalezas y las oportunidades de mejora. Se consideran estos tres ámbitos de investigación por su relación con el desarrollo humano. En este sentido se vuelve imperante conocer y explorar cual es el estado de las investigaciones científicas en Honduras dado que estos son indicadores clave para la construcción y medición de indicadores de Desarrollo Humano.
Epistemología de la formación docente: una mirada crítica
Authors: Umanzor Pastor
Published: September 2018

Este ensayo sugiere una revisión de conceptos con origen universal y que se utilizan en la formación de profesionales de la educación de manera indistinta, lo que origina confusiones a la hora de diferenciar la formación de docentes de la formación docente. Igual sucede con los conceptos: métodos, técnicas, estrategias, procedimientos y procesos. Por experiencia propia y en conversaciones con diferentes profesionales en distintas universidades, profesores y estudiantes los aceptan como conceptos conocidos, aunque con diferentes significados.De lo que trata el ensayo es intentar diferenciar esos conceptos y dar una perspectiva académica a la formación docente, que debe ser el resultado del intercambio de conocimientos sustantivos y sintácticos de las ciencias particulares y, principalmente, de los conocimientos pedagógico-didácticos-psicológicos atinentes al hecho formador: un profesor debe saber enseñar.
Dynamic Indicators of a Corn Ear Threshing Process Influenced by the Threshing-Separation Unit Load
Authors: KINIULIS Valdas , STEPONAVIČIUS Dainius , KEMZŪRAITĖ Aurelija , ANDRIUŠIS Albinas , JUKNEVIČIUS Darius
Published: September 2018

Corn ear feed rate variations in the threshing-separation unit of a combine harvester have a significant impact on the dynamic indicators of the threshing process. In this study, we conducted experiments using a stationary tangential threshing device and measured the forces acting on the rear part of the concave as well as the torque of the rotating cylinder during a threshing process. The ThreshLab software was developed for this purpose. We found that increasing the corn ear feed rate made the threshing process more even, due to decreasing the fluctuation of forces acting on the rear part of the concave and torque of the rotating cylinder. The corn ear threshing process may be more stable if the threshing cylinder is fitted with filler plates (FP-II). A comparison of the results obtained for variations in the forces acting on the rear part of the concave with those obtained for variations in the total torque of resistance and the speed of the threshing cylinder revealed a linear correlation between these parameters at varied feed rates.
DOI: http://dx.doi.org/10.5755/j01.mech.24.4.20721