bluuebunny/crossref_metadata_2025 huggingface dataset:
Mobilier Boulle : trois siècles de restaurations
Authors: Dassas Frédéric
Published: January 2021

La restauration du mobilier en marqueterie de métal est héritière de plus de trois siècles de traditions artisanales et de plusieurs décennies de recherches et de réflexion sur la conservation des œuvres patrimoniales. Un bref rappel des grandes étapes de cette histoire donne le contexte général à partir duquel furent conduits, dès 2008, les travaux sur la collection du musée du Louvre.
A chronological résumé of furniture by Boulle no longer in France, with a focus on the United Kingdom
Authors: Jackson Mia
Published: January 2021

The furniture of André-Charles Boulle is often inextricably linked to the court of Louis XIV and Versailles. Yet this would appear to be something of a mischaracterisation, for only a small percentage of pieces of furniture attributed to Boulle were made for Versailles (and even then, for the Grand Trianon or the Ménagerie rather than the main palace). Indeed, what is surprising for objects so often characterised as the nec plus ultra of French craftsmanship is how internationally travelled they are, and how often their first non-French residence was England.
The treatment of a longcase clock attributed to Jean-Pierre Latz: alternative approaches to the removal of copper corrosion products on Boulle-style marquetry
Authors: Dorscheid Jan , Considine Brian , Khanjian Herant , Wolfe Julie , Heginbotham Arlen
Published: January 2021

A longcase clock attributed to Jean-Pierre Latz from the collection of the Cleveland Museum of Art was treated at the J. Paul Getty Museum in 2012. The clock is dated to 1744 and is decorated with Boulle-style marquetry and elaborate gilt-bronze mounts. As part of the treatment, the tarnished brass marquetry was to be cleaned and brought into visual balance with the mounts’ gilded surfaces. The application of a peelable protein poultice proved effective in removing copper corrosion products from the brass elements without compromising the marquetry and its engravings. Accompanying research has pointed out the vulnerability of aged turtle shell to the heat and alkalinity related to the application of the protein poultice. As a result of this, precautionary measures could be identified.
Identification et provenance de l’écaille de tortue marine en circulation au début du xviiie siècle
Authors: Soulat Jean
Published: January 2021

Entre la fin du xviie et le début du xviiie siècle, les ébénistes parisiens ont utilisé l’écaille de tortue pour orner leur production revêtue de marqueterie Boulle. D’après les archives, il apparaît que cette écaille provenait de tortues marines pêchées dans la mer des Antilles. Débitées sur place, elles étaient acheminées en France par un réseau d’approvisionnement maîtrisé entre la métropole et ses colonies outre-Atlantique. Grâce aux recherches archéologiques et aux analyses archéométriques, on sait désormais que la plupart des écailles employées en France, notamment dans la décoration de mobilier, provenait de la carapace de tortues imbriquées.
L’examen visuel de la fonte, de la ciselure et de la dorure des bronzes d’ornementation du mobilier Boulle du musée du Louvre : rapport d’étape
Authors: Thiriet Éric , Voisot Marc
Published: January 2021

Les auteurs rapportent l’état actuel d’avancement de l’étude des marques de fonderie, ainsi que des techniques de ciselure et de dorure des bronzes du mobilier Boulle à partir des traces observées sur l’avers et le revers des pièces. Ils recensent celles qui sont relatives à l’élaboration des pièces, et celles relatives à des interventions ultérieures. Les observations sont confrontées à l’histoire évolutive des pratiques d’atelier dans chaque discipline. Plusieurs corpus émergent de cette étude, faisant ressortir des groupes cohérents de périodes différentes. Ces éléments contribuent à la compréhension de l’état actuel des œuvres et de leur évolution. L’étude en cours appelle un travail collaboratif pour augmenter les données factuelles que l’on peut traiter et comparer.
Les pigments colorés sous l’écaille et la corne
Authors: Balcar Nathalie
Published: January 2021

La récente campagne de restauration, au sein des ateliers du C2RMF, d’un ensemble de meubles du musée du Louvre décorés de marqueterie Boulle a été l’occasion de s’intéresser aux pigments utilisés pour mettre en couleur les parties en corne et en écaille de tortue. Cette étude conduite exclusivement à partir de micro-prélèvements a confirmé la technicité complexe de la mise en œuvre de ces couleurs.
Archaeometric investigations of the materials and techniques of two red figured kraters by the Painter of Louvre K 240
Authors: Conventi Alberto , D’Ignoti Katia , Lazzarini Lorenzo , Tesser Elena
Published: January 2021

Two very important red figured vases by the Painter of Louvre K 240 – the Acrobat krater preserved in the L. Bernabò-Brea Regional Archaeological Museum of Lipari (Sicily), and the Fleischman krater of the J. Paul Getty Villa (Malibu, Los Angeles) – were submitted to stylistic and archaeometric examination, the latter by powder-XRD, OM on thin sections, SEM + EDS on polished sections, and FTIR to characterise the component materials (ceramic body, black glosses, pigments and media) and the manufacturing technique. The results indicate an identical illitic, slightly calcareous clay used for the manufacture of both vases that were then painted with a very similar slip, then turned a gloss black by firing in a reducing atmosphere. The provenance of the clay could not be precisely determined so far. Both kraters were also painted with a very similar technique, so that it may be concluded that they were produced by the same artist in a unique atelier yet to be identified.
Seasonal emergence patterns ofSitodiplosis mosellana(Diptera: Cecidomyiidae) in the Peace River region, Alberta, Canada
Authors: Jorgensen Amanda , Evenden Maya L. , Olfert Owen , Otani Jennifer
Published: January 2021

Wheat midge,Sitodiplosis mosellanaGéhin (Diptera: Cecidomyiidae), is an invasive pest of wheat,Triticumspp. (Poaceae), in North America and is found in all wheat-growing regions of the world. Wheat midge biology, particularly post-diapause emergence of adults, varies with geographic region. The biology of wheat midge has not previously been examined in the northernmost area of its range in Canada – the Peace River region of Alberta. Wheat midge adult emergence was comparedin situto two phenological models of wheat midge emergence developed in other geographic regions. In-field adult emergence did not match the published phenological models. In the Peace River region, adults emerged later than are predicted by both models and precision for both models was low. With the Saskatchewan model, accumulated rainfall that was more than 110 mm in May and early June delayed emergence, whereas accumulated rainfall that was less than 43 mm during that period caused earlier than predicted emergence. Multiple peaks of wheat midge emergence, up to 20 days apart, were observed at some sites, supporting the Jacquemin model depicting “waves” of emergence. Including differences in soil temperature accumulation related to precipitation and optimising the model temperature thresholds would improve accuracy of the current Canadian phenological model in the Peace River region.
Histidine-Rich Glycoprotein Stimulates Human Neutrophil Phagocytosis and Prolongs Survival through CLEC1A
Authors: Takahashi Yohei , Wake Hidenori , Sakaguchi Masakiyo , Yoshii Yukinori , Teshigawara Kiyoshi , Wang Dengli , Nishibori Masahiro
Published: January 2021

Histidine-rich glycoprotein (HRG) is a multifunctional plasma protein and maintains the homeostasis of blood cells and vascular endothelial cells. In the current study, we demonstrate that HRG and recombinant HRG concentration dependently induced the phagocytic activity of isolated human neutrophils against fluorescence-labeled Escherichia coli and Staphylococcus aureus through the stimulation of CLEC1A receptors, maintaining their spherical round shape. The phagocytosis-inducing effects of HRG were inhibited by a specific anti-HRG Ab and enhanced by opsonization of bacteria with diluted serum. HRG and C5a prolonged the survival time of isolated human neutrophils, in association with a reduction in the spontaneous production of extracellular ROS. In contrast, HRG maintained the responsiveness of neutrophils to TNF-α, zymosan, and E. coli with regard to reactive oxygen species production. The blocking Ab for CLEC1A and recombinant CLEC1A-Fc fusion protein significantly inhibited the HRG-induced neutrophil rounding, phagocytic activity, and prolongation of survival time, suggesting the involvement of the CLEC1A receptor in the action of HRG on human neutrophils. These results as a whole indicated that HRG facilitated the clearance of E. coli and S. aureus by maintaining the neutrophil morphology and phagocytosis, contributing to the antiseptic effects of HRG in vivo.
Assessment of the Level and Factors associated with Knowledge, Attitude and Practice of Blood Donation among Medical and Paramedical Personnel in Alert Hospital, Ethiopia
Authors: Teferi Malese Yeshambaw , Woldesenbet Simon Genet , Feleke Solomon Asnakew , Abebe Ermias Hundito , Adane Hawult Taye , Alemayehu Chalachew Misganaw
Published: January 2021

Background

Though there was a high blood supply need in response to high communicable disease and increased emergency conditions; the practice of health professionals and non-health professionals on voluntary blood donation is still unexpectedly low in Ethiopia. Health professionals and non-health professionals working in the health sectors are pivotal in taking the lead to reverse the effect of inadequate blood supply system in the country. Therefore, the study aimed to understand the level and contributing factors of knowledge, attitude and practice of voluntary blood donation among health and non-health professionals in ALERT Hospital, Addis Ababa, Ethiopia.

Design and methods

A cross-sectional study design was conducted among health professionals and non-health professionals in ALERT hospital from 5 to 30 June 2018. A total of 394 hospital staffs participated in this study. A well-structured self-administered questionnaire was used to assess the knowledge, attitude, and practice about voluntary blood donation. The statistical analysis was carried out using R.

Results

A total of 203 (51.5%) participants were females. Only 142(36%) of the participants had voluntary blood donation practice. Among these, 60 (42.3%) of them were donated blood more than once. Occupation is the only factor significantly associated with blood donation practice; health professionals had almost two-fold donation practice than non-health professionals (AOR=1.62; 5% CI: 1.02, 2.57, p=0.042). Occupation has also a strong relationship with knowledge, health professionals had better knowledge than non-professionals with (AOR=2.39; 95% CI: 1.39, 4.12; p=0.002). The result also showed that the educational status of the participants was strongly associated with the blood donors’ attitude with (AOR=3.62; 95%CI: 1.1, 11.93, p=0.035). One hundred and two (72.3%) of the blood donors were motivated to donate blood for charity, 133 (94.3%) individuals were felt good after blood donation and lack of request was the major reason 88.6% that causes the respondents not to donate blood frequently.

Conclusions

Low blood donation practice of health professionals and non-health professionals was identified from this study. Occupation had significantly associated with blood donation practice. Therefore, targeted interventions aimed at mobilizing hospital staffs and develop accessible blood donation centers are recommended to reverse the effect of inadequate blood supply system in Ethiopia.
Mimesis a duende. Proces kreacji flamenco w świetle koncepcji naśladownictwa w starożytnej estetyce greckiej
Authors: Hliniak Krzysztof
Published: January 2021

The paper describes the relationship between imitation and creativity in flamenco style, referring them to the Greek concept of mimesis and comparing it with the duende concept present in this genre. Although both ideas are separated by two thousand years, they transpire to be unexpectedly convergent in their basic premises. In order to present the phenomenon of duende, the author also attempts a short answer to the question of what the phenomenon of flamenco is, what conditioned its emergence, what its characteristics are, and what forms and styles of flamenco can be currently found. Describing the phantasms about duende and a flamenco show, the author presents the process of creating a flamenco performance and its choreography. The paper refers to the accomplishments of the acclaimed Polish philosopher Władysław Tatarkiewicz, and is also a tribute to the late professor Jagna Dankowska, a sound director, a Professor of Philosophy, a Professor at the Fryderyk Chopin University of Music in Warsaw, who inspired the author to write this text.
Photocatalytic degradation of flumequine by N-doped TiO2 catalysts under simulated sunlight
Authors: Zeng Xiaolan , Sun Xiaozi , Wang Yan
Published: January 2021

Flumequine (FLU) is one of the most used fluoroquinolone antibiotics in intensive aquaculture, however, it has become a typical pollutant in water environment at present due to inappropriate use. Therefore, it is necessary to develop facile techniques for efficient degradation of FLU. In this work, three N-doped TiO2 photocatalysts were synthesized for degradation of FLU. The obtained photocatalysts were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectrum and UV-Vis diffuse reflection spectra (UV-Vis-DRS). The XRD and XPS results from NH4NO3-doped catalyst (TiO2/AN) confirmed that NO3- ions were successfully incorporated into the lattice of TiO2. The TiO2/AN sample exhibited higher photocatalytic performance than other N-doped catalysts under simulated sunlight irradiation, and 100% removal efficiency of FLU was achieved after 4 hours of illumination. The photogenerated holes (h+) and hydroxyl radicals (•OH) are main reactive species involved in the photocatalytic degradation of FLU. Eight intermediates for photocatalytic degradation of FLU were detected and their toxicities to aquatic organisms were predicted. This study might have important implications for further research on the removal of fluoroquinolone antibiotics in wastewater.
What just happened (and keeps on happening)?: The experience of COVID-19 in Canadian pharmacy practice and education
Authors: Austin Zubin
Published: January 2021

The Canadian experience in managing the first wave of COVID-19 highlights the value of unified political leadership, belief in experts, evidence-informed decision making and social cohesion. Though far from perfect, Canada's response was built upon a foundation of universally accessible health care and faith in public health guidance. Community pharmacy has been an integral part of care delivery during COVID-19. As a second or third wave evolves, it is essential to learn from previous experiences to better prepare for what comes next.
Using in silico process simulation tools in pharmacy education: Considerations for pivoting to online learning
Authors: D'Arcy Deirdre M , Pham Thi Thanh Van , Navas Bachiller Marina , Fotaki Nikoletta , Persoons Tim
Published: January 2021

The COVID-19 pandemic has required identification of pharmaceutical learning content and teaching methods which can support attainment of learning outcomes through online delivery. In silico, or computer based, process simulations are ideal tools for incorporation into online programme elements, however the scaffolding of learning with in silico tools requires a structured approach. A previously developed face-to-face workshop, which used in vitro and in silico dissolution testing, was pivoted to an online learning element using an in-house dissolution simulation programme. The learning element was developed through trial and evaluation of experiences of novice, competent and expert user(s). The delivery of the learning element was planned to address three stages of simulation learning according to the Belton model, with accompanying tools developed to aid scaffolding and assessment of competency milestones. The proposed delivery and assessment is suitable for both synchronous and asynchronous learning, and is suitable for incorporation into an Advanced Pharmaceutics module.
Review of Biosynthesis Silver Nanoparticles by Microbiology
Authors: Al-Fatlawy Dr. Hawraa Natiq Kabroot , Rahi Khwla Abd Al Kadhem , Al Zahra Diaa Sarhan Abd , Hudud Samara Rahem , Hussein Hussein Ali , Mohammed Ahmed Hazem
Published: January 2021

Nanotechnology is a multidisciplinary field that evolved within the past few decades and played a substantial role in the environment, industry, agriculture, and pharmacology. Nanoparticles are generally classified based on their dimensionality, morphology, composition, uniformity, and agglomeration. The shape, and morphology of nanoparticles play an essential role in their functionality and toxic effect on the environment and humans. In this review, we discuss the biosynthesis of nanoparticles from microbes. For the biological synthesis of nanoparticles, microbes have been exploited all over the globe. Microbes like bacteria, fungi, and yeasts are mostly preferred for nanoparticles (NPs) synthesis because of their fast growth rate, easy cultivation, and their ability to grow at ambient conditions of temperature, pH, and pressure. Applications of Nanoparticles is a field of research with tremendous prospects for the improvement of the diagnosis and treatment of human diseases. Microbial nanoparticles are found to have vigorous antibacterial activities. The nanoparticles' efficiency is probably due to their larger surface area for enhanced interaction with the micro-organisms. Nanoparticles adhere to the cell membrane and further penetrate inside by interacting with DNA, thereby interfering with the replication process or may attack the respiratory chain of pathogens. A similar bactericidal mechanism of silver nanoparticles obtained from endophytic bacterium Bacillus cereus was observed against pathogenic bacteria like Salmonella typhi, Escherichia coli, Klebsiella pneumonia, Staphylococcus aureus, and Pseudomonas aeruginosa.
LEAKAGE POWER REDUCTION IN CMOS CIRCUITS USING LEAKAGE CONTROL TRANSISTOR TECHNIQUE IN NANOSCALE TECHNOLOGY
Authors: DILIP B. , PRASAD P. SURYA , BHAVANI R. S. G.
Published: January 2021

In CMOS circuits, as the technology scales down to nanoscale, the sub-threshold leakage current increases with the decrease in the threshold voltage. LECTOR, a technique to tackle the leakage problem in CMOS circuits, uses two additional leakage control transistors, which are self-controlled, in a path from supply to ground which provides the additional resistance thereby reducing the leakage current in the path. The main advantage as compared to other techniques which involves the sleep transistor is that LECTOR technique does not require any additional control and monitoring circuitry, thereby limits the area increase and also the power dissipation in active state. Along with this, the other advantage with LECTOR technique is that it does not affect the dynamic power which is the major limitation with the other leakage reduction techniques.
DETECTING AND EFFECTIVE ROUTING OF TIME CRITICAL EVENTS USING CONGESTION AND DELAY AWARE ROUTING IN WSNS
Authors: CHIRANTHANA H. R. , SRIKANTH P. C.
Published: January 2021

Reliability and timeliness are two essential requirements of successful detection of critical events n Wireless Sensor Networks (WSNs). The base station (BS) is particularly interested about reliable and timely collection of data sent by the nodes close to the ongoing event, and at that time, the data sent by other nodes have little importance. In this paper, we modify Congestion and Delay Aware Routing (CODAR) protocol that tries to route data to the multiple sinks in congestion and delay aware manners. In this case every sensor communicates with the closest sink. If congestion occurs, it also mitigates congestion by utilizing an accurate data-rate adjustment. Each node collects control information from neighbours and works in a distributed manner. Experimental results show that modified CODAR protocol is capable of avoiding and mitigating congestion effectively, and performs better than similar known techniques in terms of reliable and timely event detection.
The problem of continuity in the philosophies of Abu Hamid al-Ghazali and Ibn Khaldun
Authors: Сандыбаев Жалғас
Published: January 2021

The article examines the problems of continuity in the philosophies of the medieval Muslim philosopher Abu Hamid al-Ghazali and Islamic jurist Ibn Khaldun, who had a great influence in various areas of Islamic science. Ibn Khaldun continued al-Ghazali’s idea about a person who forced to communicate with other members of society. Therefore, people with different social status should be treated with respect. Developing this concept, Ibn Khaldun began with the highest posts of the state, namely: ruler, vizier, sultan, akim, leader, etc. Abu Hamid al-Ghazali explains the reasons for the collapse of the government and the state, as well as talks in detail about measures of prevention. Ibn Khaldun describes the stages that a society must go through to become a strong state, thus complementing al-Ghazali’s idea of an ideal society.The author tells that the teachings of Abu Hamid al-Ghazali about morality, power, politics, theology, philosophy, logic, morality and jurisprudence were noticeable not only in the Turds of Ibn Khaldun, who is well known in the historical, philosophical and political world of the Muslim East, but also in the works of many prominent Islamic thinkers. For example, the influence of the doctrine of theology of al-Ghazali was not limited to Fakhriddin ar-Razi, on the contrary, it embraced all the scientists who came after him and survived to these days. Thus, the followers of al-Razi, from Asar ad-Din al-Aybari to Muhammad ibn Namuar al-Khunji, continued the teachings of al-Ghazali.
USE OF SYNERGETIC APPROACH TO STUDY THE CONCEPT OF ALISHER NAVOI’S IDEAL PERSON BASED ON THE EXAMPLE OF THE WORK “MAHBUB UL-KULUB”
Authors: Tursunov Bakhtiyor
Published: January 2021

Based on a synergetic approach, the article makes an attempt to study the issues of a perfect person on the example of the work “Mahbub ul-kulub” by the great poet and thinker Alisher Navoi. In the work of Navoi, the idea of a perfect person is analyzed by studying the instructions given by him on the upbringing and spiritual enlightenment of representatives of various groups and different strata of the society at that time. The poet describes the behavioral characteristics of various social groups and members of the society of his time, explains in a more detail way compared to his other works, and explains which of the characteristics are worthy and should be mastered, and which are not. The thinker emphasizes positive qualities in his work, which are important for achieving harmony in life, and also encourages readers to get rid of negative qualities. Thus, the poet develops noble qualities in the readers and pushes them on the path to improvement. A detailed study of the work of the great thinker shows the relevance of his teachings in the current time.
ГУМАНИТАРЛЫҚ БІЛІМ ЖҮЙЕСІНДЕГІ РУХАНИЛЫҚ: ЛОГИКАЛЫҚ-ӘДІСТЕМЕЛІК АСПЕКТІЛЕР
Authors: Дусипова Айсана , Иманмолдаева Бакиттижамал
Published: January 2021

Қазіргі уақытта адамзаттың өсіп келе жатқан қажеттіліктері мен биосфераның салыстырмалы түрде шектеулі мүмкіндіктері арасындағы қайшылықтар антропосфераның одан әрі өмір сүруіне қауіп төндіретіні белгілі болды. Жаһандану жағдайында рухани құндылықтар жүйесінің мәселелері өзекті болып отыр. Мақалада руханилық ұғымын әдіснамалық түсіну тәсілдері, анықтама-лық мәндері мен мағынасы қарастырылды. Руханилықтың жалпы түсіндірмелері, руханилық түсіндірілуіндегі логикалық қайшылықтар талданды. Руханилық мәдениеттің бөлшегі ретінде гуманитарлық білім жүйесінде адам мен руханилық арасындағы арақатынас талданды. Сондықтан руханилықты, тұтас тұрғыдан, яғни жан-жақты және интегративті анықтама ретінде тұтас көзқарас тұрғысынан түсіну керектігін алға тартамыз
BEPS EYLEM PLANLARI KAPSAMINDA TÜRK VERGİ MEVZUATINDA YAPILAN DEĞİŞİKLİKLER
Authors: Gedik Gülşen
Published: January 2021

Yurtiçi vergi matrağı erozyonu ve karın aktarılması (Base Erosion and Profit Shifting- BEPS) çok uluslu işletmeler tarafından kullanılan vergi ödemekten kaçınma amaçlı vergi yasalarındaki boşlukları kullanan vergi planlama stratejilerine gönderme yapmaktadır. Gelişmiş ülkelerin kurumlar vergisi esası BEPS’den büyük ölçüde ayrılmaktadır. OECD, 2015 tarihinde 13 final raporu yayınlamış ve BEPS projesi kapsamında açıklamalara yer vermiştir. BEPS Eylem Planları OECD üyesi tüm ülkeler için katı hukuk kuralları gibi bağlayıcı olmamakla birlikte referans alınması ve iç mevzuat değişiklikleri yapılması önemlidir. Türkiye de BEPS Eylem Planları kapsamında mevzuatta bazı değişiklikler yapmış; ancak tüm tavsiyelere uygun bir strateji hala geliştirememiştir.
Measurement Report: Online Measurement of Gas-Phase Nitrated
Phenols Utilizing CI-LToF-MS: Primary Sources and Secondary
Formation
Authors: Song Kai , Guo Song , Wang Haichao , Yu Ying , Wang Hui , Tang Rongzhi , Xia Shiyong , Gong Yuanzheng , Wan Zichao , Lv Daqi , Tan Rui , Zhu Wenfei , Shen Ruizhe , Li Xin , Yu Xuena , Chen Shiyi , Zeng Liming , Huang Xiaofeng
Published: January 2021

Abstract. To investigate the composition, variation, and sources of nitrated phenols (NPs) in the winter of Beijing, gas-phase NPs were measured by using a chemical ionization long time-of-flight mass spectrometer (CI-LToF-MS). A box model was applied to simulate the secondary formation process of NPs. In addition, the primary sources of NPs were resolved by non-negative matrix factorization (NMF) model. Our results showed that secondary formation contributed 38 %, 9 %, 5 %, 17 % and almost 100 % of the ambient nitrophenol (NP), methyl-nitrophenol (MNP), dinitrophenol (DNP), methyl-dinitrophenol (MDNP or DNOC), and dimethyl-nitrophenol (DMNP). Phenol-OH reaction was the predominant loss pathway (46.7  %) during the heavy pollution episode, which produced phenoxy radical (C6H5O). The phenoxy radical consequently reacted with NO2, and produced nitrophenol. By estimating the primarily emitted phenol from the ratio of phenol/CO from freshly emitted vehicle exhaust, this study proposed that oxidation of primary phenol contributes much more nitrophenol (37 %) than that from benzene oxidation ( 50 %) to the gas-phase NPs. The industry source contributed 30 % and 9 % to DNP and MDNP, respectively, which was non-negligible. The concentration weighted trajectory (CWT) analysis demonstrated that regional transport from provinces that surround the Yellow and Bohai Seas contributed more primary NPs to Beijing. Both primary sources and secondary formation in either local or regional scale should be considered when making NPs control policies.
Dust Induced Atmospheric Absorption Improves Tropical
Precipitations In Climate Models
Authors: Balkanski Yves , Bonnet Rémy , Boucher Olivier , Checa-Garcia Ramiro , Servonnat Jérôme
Published: January 2021

Abstract. The amount of shortwave radiation absorbed by dust has remained uncertain. We have developed a more accurate representation of dust absorption that is based on the observed dust mineralogical composition and accounts for very large particles. We analyze the results from two fully-coupled climate simulations of 100 years in terms of their simulated precipitation patterns against observations. A striking benefit of the new dust optical and physical properties is that tropical precipitations over Sahel, tropical North Atlantic and West Indian Ocean are significantly improved compared to observations, without degrading precipitations elsewhere. This alleviates a persistent bias in earth system models that exhibit a summer African monsoon that does not reach far enough North. We show that the improvement results from a thermodynamical and dynamical response to dust absorption is unrelated to natural variability. Aerosol absorption induces more water vapor advection from the ocean to the Sahel, thereby providing an added supply of moisture available for precipitation. This work thus provides a path towards improving precipitation patterns in these regions by more realistically accounting for both physical and optical properties of the aerosol.
Evaluation of single-footprint AIRS CH4 profile retrieval uncertainties using aircraft profile measurements
Authors: Kulawik Susan S. , Worden John R. , Payne Vivienne H. , Fu Dejian , Wofsy Steven C. , McKain Kathryn , Sweeney Colm , Daube Jr. Bruce C. , Lipton Alan , Polonsky Igor , He Yuguang , Cady-Pereira Karen E. , Dlugokencky Edward J. , Jacob Daniel J. , Yin Yi
Published: January 2021

Abstract. We evaluate the uncertainties of methane optimal estimation retrievals from single-footprint thermal infrared observations from the Atmospheric Infrared Sounder (AIRS). These retrievals are primarily sensitive to atmospheric methane in the mid-troposphere through the lower stratosphere
(∼2 to ∼17 km). We compare them to in situ observations made from aircraft during the
HIAPER Pole to Pole Observations (HIPPO) and Atmospheric Tomography Mission (ATom) campaigns, and
from the NOAA GML aircraft network, between the surface and 5–13 km, across a range of
years, latitudes between 60∘ S to 80∘ N, and over land and ocean. After a
global, pressure-dependent bias correction, we find that the land and ocean have similar biases
and that the reported observation error (combined measurement and interference errors) of
∼27 ppb is consistent with the SD between aircraft and individual AIRS
observations. A single observation has measurement (noise related) uncertainty of
∼17 ppb, a ∼20 ppb uncertainty from radiative interferences (e.g., from
water or temperature), and ∼30 ppb due to “smoothing error”, which is partially
removed when making comparisons to in situ measurements or models in a way that accounts for this
regularization. We estimate a 10 ppb validation uncertainty because the aircraft typically
did not measure methane at altitudes where the AIRS measurements have some sensitivity, e.g., the
stratosphere, and there is uncertainty in the truth that we validate against. Daily averaging only
partly reduces the difference between aircraft and satellite observation, likely because of
correlated errors introduced into the retrieval from temperature and water vapor. For example,
averaging nine observations only reduces the aircraft–model difference to ∼17 ppb
vs. the expected ∼10 ppb. Seasonal averages can reduce this ∼17 ppb
uncertainty further to ∼10 ppb, as determined through comparison with NOAA aircraft,
likely because uncertainties related to radiative effects of temperature and water vapor are
reduced when averaged over a season.
Quantifying organic matter and functional groups in particulate
matter filter samples from the southeastern United States – Part 2:
Spatiotemporal Trends
Authors: Boris Alexandra J. , Takahama Satoshi , Weakley Andrew T. , Debus Bruno M. , Shaw Stephanie L. , Edgerton Eric S. , Joo Taekyu , Ng Nga L. , Dillner Ann M.
Published: January 2021

Abstract. Organic species within atmospheric particles vary widely in molecular structure. The variety of molecules that comprise the aerosol make it rich in information about its sources and chemical lifecycle but also make particulate organic matter (OM) difficult to characterize and quantify. In Part 1 of this pair of papers, we described a direct method for measuring the composition and concentration of OM in aerosol samples that is compatible with routine monitoring of air quality. This method uses Fourier Transform Infrared (FT-IR) spectrometry of filter-based aerosol samples to quantify bonds, or functional groups, that represent the majority of organic composition; summation of these functional groups gives OM. In this paper, functional group composition and OM concentrations are directly measured in eight years of aerosol samples collected at two rural and two urban sites in the Southeastern Aerosol Research and Characterization (SEARCH) network. FT-IR spectrometry with a multivariate calibration is used to quantify the concentrations of aliphatic C-H (aCH), carboxylic acid (COOH), oxalate (oxOCO; representing carboxylates), non-acid and non-oxalate carbonyl (naCO), and alcohol O-H (aCOH) in approximately 3500 filter samples collected every third day from 2009 through 2016. In addition, measurements are made on samples from all days in 2016. A decline in the total OM is observed from 2011 to 2016 that is caused by decreases in the more oxygenated functional groups (carboxylic acid and oxalate) and is attributed to anthropogenic SO2 and/or volatile organic compound (VOC) emissions reductions. The trend in OM composition is consistent with those observed using more time- and labor-intensive analytical techniques. Concurrently, the fractional contributions of aCOH and naCO to OM increased, which might be linked to monoterpene-derived secondary OM, with possible influences from decreasing NOx and/or increasing O3 concentrations. In addition, this work demonstrates that OM to organic carbon (OM / OC) ratios in the Southeast U.S. (SE U.S.) did not appreciably change over the study time period, as a result of these competing functional group contributions to OM. Monthly observations support the sources suggested by these overall trends, including strong biogenic and photo-oxidation influences, while daily samples from 2016 further elucidate the consistent impact of meteorology and biomass burning events on shorter term OM variability, including prescribed burning in the winter/spring and wildfires in the autumn. These shorter-term and spatial observations thus reinforce the results of the broader dataset and serve to evaluate the applicability of FT-IR spectrometry measurement to trends analysis on various timescales relevant to routine monitoring of aerosol composition.
A Lagrangian study of the contribution of the Canary coastal upwelling to the nitrogen budget of the open North Atlantic
Authors: Hailegeorgis Derara , Lachkar Zouhair , Rieper Christoph , Gruber Nicolas
Published: January 2021

Abstract. The Canary Current System (CanCS) is a major eastern boundary upwelling system (EBUS), known for its high nearshore productivity and for sustaining a large fishery. It is also an important but not well quantified source of nitrogen to the adjacent oligotrophic subtropical gyre of the North Atlantic. Here, we use a Lagrangian modeling approach to quantify this offshore transport and investigate its timescales, reach and contribution to the fueling of productivity in the offshore regions. In our Lagrangian model, we release nearly 10 million particles off the northwestern African coast and then track all those that enter the nearshore region and upwell along the coast between 14 and 35∘ N. We then follow them as they are transported offshore, also tracking the biogeochemical transformations, permitting us to construct biogeochemical budgets along the offshore moving particles. The three-dimensional velocity field as well as the biogeochemical tracers and fluxes are taken from an eddy-resolving configuration of the Regional Ocean Modeling System (ROMS). Our Lagrangian model analysis reveals a very intense offshore transport of nitrogen, with about 20 %–40 % in the form of organic nitrogen. The transport varies greatly along the coast. Even though the central CanCS (21–28∘ N) transports the largest amount of water offshore, its offshore transport of nitrogen is somewhat smaller than that in the southern CanCS (14–21∘ N), primarily because of the higher nitrogen content of the upwelling waters there. Around one-third of the total offshore transport of water occurs around major capes along the CanCS. The persistent filaments associated with these capes are responsible for an up to 4-fold enhancement of the offshore transport of water and nitrogen in the first 400 km. Much of this water and nitrogen stems from upwelling at quite some distance from the capes, confirming the capes' role in collecting water from along the coast. North of Cape Blanc and within the first 500 km from the coast, water recirculation is a dominant feature of offshore transport. This process, likely associated with mesoscale eddies, tends to reduce the efficiency of offshore transport. The Canary upwelling is modeled to supply around 44 and 7 mmol N m−2 yr−1 to the North Atlantic Tropical Gyral (NATR) and the North Atlantic Subtropical Gyral East (NASE) Longhurst provinces, respectively. In the NATR, this represents nearly half (53 ± 26 %) of the estimated total new production, while in the NASE, this fraction is small (4 ± 2 %). Our results highlight the importance of the CanCS upwelling as a key source of nitrogen to the open North Atlantic and stress the need for improving the representation of EBUS in global coarse-resolution models.
Sequential changes in ocean circulation and biological export productivity during the last glacial–interglacial cycle: a model–data study
Authors: O'Neill Cameron M. , Hogg Andrew McC. , Ellwood Michael J. , Opdyke Bradley N. , Eggins Stephen M.
Published: January 2021

Abstract. We conduct a model–data analysis of the marine carbon cycle to understand and quantify the drivers of atmospheric CO2 concentration during the last glacial–interglacial cycle. We use a carbon cycle box model, “SCP-M”, combined with multiple proxy data for the atmosphere and ocean, to test for variations in ocean circulation and Southern Ocean biological export productivity across marine isotope stages spanning 130 000 years ago to the present. The model is constrained by proxy data associated with a range of environmental conditions including sea surface temperature, salinity, ocean volume, sea-ice cover and shallow-water carbonate production. Model parameters for global ocean circulation, Atlantic meridional overturning circulation and Southern Ocean biological export productivity are optimized in each marine isotope stage against proxy data for atmospheric CO2, δ13C and Δ14C and deep-ocean δ13C, Δ14C and CO32-. Our model–data results suggest that global overturning circulation weakened during Marine Isotope Stage 5d, coincident with a ∼ 25 ppm fall in atmospheric CO2 from the last interglacial period. There was a transient slowdown in Atlantic meridional overturning circulation during Marine Isotope Stage 5b, followed by a more pronounced slowdown and enhanced Southern Ocean biological export productivity during Marine Isotope Stage 4 (∼ −30 ppm). In this model, the Last Glacial Maximum was characterized by relatively weak global ocean and Atlantic meridional overturning circulation and increased Southern Ocean biological export productivity (∼ −20 ppm during MIS 3 and MIS 2). Ocean circulation and Southern Ocean biological export productivity returned to modern values by the Holocene period. The terrestrial biosphere decreased by 385 Pg C in the lead-up to the Last Glacial Maximum, followed by a period of intense regrowth during the last glacial termination and the Holocene (∼ 600 Pg C). Slowing ocean circulation, a colder ocean and to a lesser extent shallow carbonate dissolution contributed ∼ −70 ppm to atmospheric CO2 in the ∼ 100 000-year lead-up to the Last Glacial Maximum, with a further ∼ −15 ppm contributed during the glacial maximum. Our model results also suggest that an increase in Southern Ocean biological export productivity was one of the ingredients required to achieve the Last Glacial Maximum atmospheric CO2 level. We find that the incorporation of glacial–interglacial proxy data into a simple quantitative ocean transport model provides useful insights into the timing of past changes in ocean processes, enhancing our understanding of the carbon cycle during the last glacial–interglacial period.
A 14-yr Circum-Antarctic Iceberg Calving Dataset Derived from
Continuous Satellite Observations
Authors: Qi Mengzhen , Liu Yan , Liu Jiping , Cheng Xiao , Feng Qiyang , Shen Qiang , Yu Zhitong
Published: January 2021

Abstract. Iceberg calving is the main process that facilitates the dynamic mass loss of ice sheets into the ocean, which accounts for approximately half of the net mass loss of all Antarctic ice shelves. Fine-scale calving variability observations can help reveal the involved calving mechanisms and identify the principal processes that influence how the changing climate affects the mass loss of ice sheets. Iceberg calving from specific ice shelves or regions has been monitored before, but there is still a lack of consistent, long-term and high-precision records on independent calving events for all Antarctic ice shelves. In this study, we developed a circum-Antarctic annual iceberg calving product measuring every independent calving event larger than 1 km2 that occurred from August 2005 to August 2019. We first simulated the expansion of the coastline according to ice velocity, and then manually delineated the calved areas, which are considered to be the differences between the simulated coastline and the actual coastline derived from the corresponding satellite imagery, based on 15 years of continuous multisource optical and synthetic aperture radar images. This product provides detailed information on each calving event, including the associated year of occurrence, area, size, average thickness, mass, recurrence interval, type, and measurement uncertainties. In total, 1786 annual calving events occurred on the Antarctic ice shelves from August 2005 to August 2019. The average annual calving area was measured as 3411.4 km2 with an uncertainty value of 17.1 km2, and the average calving rate was measured as 771.1 Gt/yr with an uncertainty value of 10.2 Gt/yr. The calving frequency, area, and mass fluctuated moderately during the first decade, followed by a dramatic increase from 2015/16 to 2018/19. During the dataset period, large ice shelves, such as the Ronne-Filchner, Ross and Amery Ice Shelves, advanced with low calving frequency, while small and medium-sized ice shelves retreated and calved more frequently. Iceberg calving is most prevalent in West Antarctica, followed by the Antarctic Peninsula and Wilkes Land in East Antarctica. The annual circum-Antarctic iceberg calving dataset provides consistent and precise calving observations with the longest time coverage. The dataset provides multidimensional variables for each independent calving event that can be used to study detailed spatiotemporal variations in Antarctic iceberg calving. The dataset can also be used to study ice sheet mass balance, calving mechanisms and the responses of iceberg calving to climate change. The dataset is shared via Global Change Data Repository (href="http://www.geodoi.ac.cn/WebEn/doi.aspx?Id=1516), and entitled Annual iceberg calving dataset of the Antarctic ice shelves (2005–2019) with DOI: https://doi.org/10.3974/geodb.2020.04.09.V1.
Optimization of the sulfate aerosol hygroscopicity parameter in WRF-Chem
Authors: Kim Ah-Hyun , Yum Seong Soo , Chang Dong Yeong , Park Minsu
Published: January 2021

Abstract. A new sulfate aerosol hygroscopicity parameter (κSO4) parameterization is suggested that is capable of considering the two major sulfate aerosols, H2SO4 and (NH4)2SO4, using the molar ratio of ammonium to sulfate (R). An alternative κSO4 parameterization method is also suggested that utilizes typical geographical distribution patterns of sulfate and ammonium, which can be used when ammonium data are not available for model calculation. Using the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem), the impacts of different κSO4 parameterizations on cloud microphysical properties and cloud radiative effects in East Asia are examined. Comparisons with the observational data obtained from an aircraft field campaign suggest that the new κSO4 parameterizations simulate more reliable aerosol and cloud condensation nuclei concentrations, especially over the sea in East Asia, than the original κSO4 parameterization in WRF-Chem that assumes sulfate aerosols as (NH4)2SO4 only. With the new κSO4 parameterizations, the simulated cloud microphysical properties and precipitation became significantly different, resulting in a greater cloud albedo effect of about −1.5 W m−2 in East Asia than that with the original κSO4 parameterization. The new κSO4 parameterizations are simple and readily applicable to numerical studies investigating the impact of sulfate aerosols in aerosol–cloud interactions without additional computational expense.
Approximate Representations of Shaped Pulses Using the Homotopy
Analysis Method
Authors: Crawley Timothy , Palmer III Arthur G.
Published: January 2021

Abstract. The evolution of nuclear spin magnetization during a radiofrequency pulse in the absence of relaxation or coupling interactions can be described by three Euler angles. The Euler angles in turn can be obtained from the solution of a Riccati differential equation; however, analytic solutions exist only for rectangular and chirp pulses. The Homotopy Analysis Method is used to obtain new approximate solutions to the Riccati equation for shaped radiofrequency pulses in NMR spectroscopy. The results of even relatively low orders of approximation are highly accurate and can be calculated very efficiently. The Homotopy Analysis Method is powerful and flexible and is likely to have other applications in theoretical magnetic resonance.
A 30 m scale modeling of extreme gusts during Hurricane Irma (2017) landfall on very small mountainous islands in the Lesser Antilles
Authors: Cécé Raphaël , Bernard Didier , Krien Yann , Leone Frédéric , Candela Thomas , Péroche Matthieu , Biabiany Emmanuel , Arnaud Gael , Belmadani Ali , Palany Philippe , Zahibo Narcisse
Published: January 2021

Abstract. In view of the high vulnerability of the small islands of the Lesser Antilles to cyclonic hazards, realistic very fine scale numerical simulation of hurricane-induced winds is essential to prevent and manage risks. The present innovative modeling aims at combining the most realistically simulated strongest gusts driven by tornado-scale vortices within the eyewall and the most realistic complex terrain effects. The Weather Research and Forecasting (WRF) model with the nonlinear backscatter and anisotropy (NBA) large eddy simulation (LES) configuration was used to reconstruct the devastating landfall of category 5 Hurricane Irma (2017) on Saint Barthélemy and Saint Martin. The results pointed out that the 30 m scale seems necessary to simulate structures of multiple subtornadic-scale vortices leading to extreme peak gusts of 132 m s−1 over the sea. Based on the literature, such extreme gust values have already been observed and are expected for category 5 hurricanes like Irma. Risk areas associated with terrain gust speed-up factors greater than 1 have been identified for the two islands. The comparison between the simulated gusts and the remote sensing building damage highlighted the major role of structure strength linked with the
socio-economic development of the territory. The present modeling method could be easily extended to other small mountainous islands to improve the
understanding of observed past damage and to develop safer urban management
and appropriate building standards.