bluuebunny/crossref_metadata_2025 huggingface dataset:
Hybrid Family: Interview with Maja Smrekar
Authors: Colner Miha , Smrekar Maja
Published: November 2020

Maja Smrekar is a visual artist addressing current phenomena in contemporary society. Her earlier works often touch upon the mundane permeated by stereotypes of popular culture, the future as understood through fiction, and the ethical aspects of human interventions in nature and natural processes. In 2014, she began performing her continuous work K-9_topology, in which she analyses the causes and consequences of human domination on the planet, and questions the self-evidence of the anthropogenic mentality. During the following four years, this artistic research and extremely interdisciplinary action led her to deeply explore the relationship between a human and a dog. Individual elements of the project were introduced through performance, installation, artist book, and photography. The following interview focuses on this segment of her work; on her reflections on the relationship between a human and an animal; and on certain important social contexts that define her work.

Keywords: contemporary art, human-dog relation, performance art, posthumanism, wildlife domestication
From Postmodernism to Posthumanism: The Photographed Animal
Authors: Baker Carole
Published: November 2020

This essay was inspired by the growing critical and artistic attention currently afforded to the subject of the nonhuman animal within Posthumanism and a curiosity to explore photographic practices that could potentially contribute to this endeavour. An exploration of Postmodernist art practice has revealed a dramatic shift in approach to the nonhuman animal subject; essentially characterised as a move from a sceptical, emotionally-distanced, theoretically-grounded range of practices to those that are emotionally-engaged, affective and ethically responsive. This is not to suggest that this characterises all Posthumanist photographic practices; a number of critical writers ably theorise about global networks, nonhuman photography, abstraction of vision. Instead, I examine photographic practices which are embedded within compassion, generosity, responsibility. This is not a return to the modernist notion of the artist and his or hers creation, but a plea for productive interrelations based on equality and experimentation which will potentially lead to novel ways of living. Keywords: animality, art photography, nonhuman, photography of animals, posthumanism
The Photographs of Dead Animals
Authors: Tekin Nezaket
Published: November 2020

“Why look at animals?” asks art critic John Berger. I would like to address this question by paraprashing it and asking instead, “why look at dead animals?” Extinct or rare animals are the most interesting objects of the camera of curiosities and natural history museums. Hiroshi Sugimoto focuses on the dioramas where animals are shown in their habitats. Lynn Savarese revitalizes taxidermied animals as heroes of a story. Humans and animals have equal value in Michael Ackerman’s photographs. Nobuyoshi Araki’s visual diaries contain stories on life and death. Nezaket Tekin creates utopist scenes using insects. Her other work also involves documenting dead animals.

Keywords: dead animals, dead people, photographs of dead animals, post-mortem photography, spirit photography
If There is No Community, There is No City: Interview with Murat Germen
Authors: Pevec Iza , Germen Murat
Published: November 2020

Public space directs how we live and act, how we socialize and even protest. If there is no community and solidarity there is no city, no civilization; there can only be a »city-state« as the modern version of an empire, says Murat Germen, photographer known for his critical view on the home-town of Istanbul. Muta-morphosis, probably one of his most famous series, uses digital manipulation to show a dark vision of future cities: buildings cramed together as in a strange and dangerous mutation process, almost melting as objects in Dali’s paintings. Through his artworks, text and lectures, Murat Germen criticizes excessive urbanization, motivated by capital and not by human needs. He also documented Gezi Park protests, in which the political aspect of managing the city became very apparent. His photos can be understood as a visual protest and Murat Germen thinks some of them may turn into visual evidence of the urban crime committed by the present Turkish government since 2002, when it came to power.

Keywords: art, art and social power, gentrification, urbanism, visual protest
The Best Weapon is Camera: Interview with Gabriel Uchida
Authors: Hisayasu Louise , Uchida Gabriel
Published: November 2020

Contribution focuses on the series Travelling Through the Territory by Brazilian photographer, Gabriel Uchida, in collaboration with the Uru-eu-wau-wau. In the interview, his experience living and collaborating with the Native peoples of the Amazon, the political climate in Brazil and the unsettling feeling towards the destruction of the Amazon are discussed. Brazil’s historical narrative has largely situated itself in contraposition to Indigenous narratives, which are often marginalized and submerged to a time immemorial. Illegal land invasions, death threats and injustice are on the rise, heightened by the damaging rhetoric of President Bolsonaro. Today, the Indigenous population is inseparable from resistance and protest, photography lends itself as a tool for self-defense and preservation. Besides cameras, the Internet is largely accessible, compact (smartphones) and provides direct contact with global audiences, contributing to the circulation of information and unbiased narratives.

Keywords: amazon, Brazil, indigenous, marginal narratives, uru-eu-wau-wau
Transvaluation and Aesthetic Displacement: Gezi Park and the Power of Art
Authors: Snyder Stephen
Published: November 2020

The wave of demonstrations that developed out of the Gezi Park sit-ins manifested a form of aesthetic creativity that employed transvaluation and displacement in a way that set them apart from other protests in Turkey and the Arab world. Transvaluation and displacement were arguably among the primary forces that drove the protests following the forceful breakup of the Gezi Park sit-ins. The protests began when police forcefully removed sleeping demonstrators from Gezi Park. To most observers, the police use of violence to clear the park was deemed disproportionate, and the resistance countered the tear gas, truncheons, water cannons, and detentions with a level of aesthetic intensity that surprised detractors as well as supporters. The primary aim of the movement was to protect a park in the center of Istanbul, but the resistance represented a broad coalition of those who opposed what they perceived as the autocratic ruling style of then Prime Minister Recep Tayyip Erdoğan. They ranged from anti-capitalist Muslims to students who simply opposed the Prime Minister’s Islamification of the Turkish public sphere. Examining the way in which transvalution and displacement were used as a response to the force employed by riot police at the direction of the Turkish government shows how political art was employed effectively in the Gezi Park protests. Keywords: aesthetics displacement, art and social power, Gezi Park, political, political art, politics and aesthetics, protest
Semiotics of the Protest
Authors: Paschalidou Maria
Published: November 2020

In the Semiotics of the Protest performed video, I visually examine the key significance of the body and its language for the materialization of the street protest, the vital tool by means of which people reclaim public space and activate it as a political terrain. The video is based on a performance for which I invited a volunteer dancer to “rehearse” public gestures of resistance against oppression. Challenging dominant representations of protestors as “mobs” and protestors’ bodies as irrational and uncontrollable entities, in this performed video, I visually analyse the political demonstration as choreographic tactics executed by bodies which are meaningful and purposeful and which, through their gestures, move forward to social change.

Keywords: participation, performed video, Phantasmagoria, politics and aesthetics, protest as choreography
Actions. Situations. Possible Scenarios.
Authors: Selejan Ileana L.
Published: November 2020

Zigzagging through personal memory and historical episodes of great consequence – the fall of the Berlin wall, the Romanian revolution and the April 2018 protests in Nicaragua – the essay seeks points of connection between the personal and the political, exploring how the two are intimately and inextricably intertwined. The textual approach can be situated in-between historical analysis and auto-biographical fiction; the aim is to enable multi-layered narratives, and contrasting, conflicting temporalities to co-exist. Illustrative of this intent, Romanian artist Călin Man intervenes upon the more well-known documentary photographs referenced in the text, by conflating them with everyday snapshots from the city of Arad taken at different points along the temporal arc described.

Keywords: documentary, memory, personal history, photography, revolution, transnationalism
Digital Intifada: Photography as Protest in Palestine
Authors: Beldea Alex
Published: November 2020

A myriad of images inundates us daily with sequences from a more or less proximate reality, leaving us with the task of negotiating our responses to these representations that empathically seek our attention. The images that we encounter arrive in various forms on various platforms: advertising photographs, surveillance images, selfies, pictures of war or citizen photographs… In the midst of this new and dynamic representational landscape, independent activist groups and photographers documenting injustices around the world have become more prevalent, taking advantage of accessible means of photographic capture and of the possibility for immediate sharing of images with the world. Palestine is one of the places where injustices happen on a daily basis, leaving Palestinians with few and unequal means to respond with a counter narrative. This new online reality with its social media platforms has its own limitations but it is now an important part of their resistance, with photography being used as a form of protest. Citizen and independent photographers, such as Janna Tamimi and the Activestills group, are using these online channels to attest to injustice and oppression themselves, regardless of the presence of the photojournalist as a witness. The professional stance of photojournalists and their objective observations are assumptions that have been fading out, motivating non-professionals from Palestine, and other places, to disseminate imagery with the hope to be seen and to be heard.

Keywords: Citizen Photography, new media, Palestine, protest, social media
An Example of a Diachronic Imagination from the Gezi Uprising
Authors: Batur Ayse Lucie
Published: November 2020

Gezi Uprising was a wave of popular protests and horizontal mobilizations that emerged at the urban center of Istanbul against the destruction of a public park at the end of May 2013 and then quickly spread across the country. Gezi Uprising was marked by a revolutionary visual strategy of commoning images and repurposing them and this helped connect many protesting neighborhoods and locations, and their specific grievances. Along this synchronic imagination of the protest, the circulation of images also fostered a diachronic imagination that connected past struggles and experiences with the current ones, creating a sense of temporal connections of experiences of this newly imagined community. The photocollages of graphic designer and artist Füsun Turcan Elmasoğlu illustrates the mode through which the heightened diachronic imagination was fostered by the collective creativity during the uprising. Elmasoğlu created collages by bringing images that belong to the same place but 38 years apart; images from the large Labor Day demonstration at Taksim Square in 1977, “the Bloody May 1” together with current images of the square.

Keywords: Gezi Park, protest, radical imagination, social movements, visual culture
Photographs of the Miners’ Raids: Reworking Images of the Past and Negotiating the Present
Authors: Mihalcea Ioan Daniel
Published: November 2020

This paper investigates the conditions in which photojournalistic images of the past are becoming iconic and it also traces the ways in which such images actively negotiate the meanings of particular events. Starting from Robert Hariman and John Lucaites’ iconic photography methodology (2007), this research aims to clarify how iconicity operates in specific situations defined by cultural and digital circumstances. The proposed case study analyses the photographs of the events known as Miners’ Raids that took place in Bucharest, Romania in the aftermath of the December 1989 Revolution. First, through a close reading of the aesthetic qualities of the photographic composition, I investigate how images themselves are sites where meaning is produced and how they have the power to sustain multiple and sometimes contradictory semiotic transcriptions. Second, I trace the circulation and appropriation of these photographs to argue their capacity to generate debates and absorb new meanings in the course of their afterlives. The purpose is to understand how photography can work as a distinct category that can articulate complex ideas, judgments, and dialogue.

Keywords: close reading, dissent, iconic photography, remobilization, Romanian public culture
Evaluation of methods for analyzing early-age cracking risk in concrete walls of tunnel structures
Authors: Tu Anh Do , Luan Minh Ha , Quang Thac Nguyen , Tam Duc Tran , Thang Quoc Tham
Published: November 2020

This paper is concentrated on investigating the modern methods to evaluate the probability of cracking in urban tunnel structures during construction. The study considers the current standard methods for assessing reinforced concrete walls of an urban tunnel, which experienced early-age cracking. The results obtained using guidelines were compared with actual observations of crack widths in the urban tunnel wall. Examples of using specifications in wall design were also described. The proper method is highlighted with suggestions for a possible path for considering early-age thermal and shrinkage effects in urban reinforced concrete tunnel walls
Overview of BIM application for bridge - highway and infrastructure projects in Viet Nam
Authors: Ngo Thanh Thuy , Do Minh Truyen , Huynh Xuan Tin
Published: November 2020

In recent years, the industrial revolution 4.0 has been strongly happening and affecting many industries and fields thanks to the rapid development of science and technology. Many new technologies have been developed and applied in the construction industry, increasing labor productivity and work efficiency, and reducing construction waste. One of these new technologies is Building Information Modeling (BIM), which is being strongly developed and evaluated as a key technology for the construction industry. BIM defines all property information related to a full lifecycle of a target structure, from planning and design to construction, operation, and maintenance. In Vietnam, BIM has been effective for certified projects using state budget, private capital, or foreign investment, and gradually there is a positive change. The goal of this paper is to provide a comprehensive, up to date literature review, analysis of research areas regarding BIM for bridge, highway, infrastructure, and some applications in this domain in Vietnam
Effect of ground granulated blast funrnace slag and fly ash on strength, permeability, and under-water abrasion of fine-grained concrete
Authors: Truong Van Quyet , Nguyen Thanh Sang
Published: November 2020

The utilisation of supplementary cementitious materials (SCMs) is widespread in the concrete industry because of the performance benefits and economic. Ground granulated blast furnace slag (GGBFS) and fly ash (FA) have been used as the SCMs in concrete for reducing the weight of cement and improving durability properties. In this study, GGBFS at different cement replacement ratios of 0%, 20%, 40% and 60% by weight were used in fine-grained concrete. The ternary binders containing GGBFS and FA at cement replacement ratio of 60% by weight have also evaluated. Flexural and compressive strength test, rapid chloride permeability test and under-water abrasion test were performed. Experimental results show that the increase in concrete strength with GGBFS contents from 20% to 40% but at a higher period of maturity (56 days and more). The chloride permeability the under-water abrasion reduced with the increasing cement replacement by GGBFS or a combination of GGBFS and FA
Dye sensitized solar cell (DSC) based on reduced graphene oxide (rGO)-TiO2 nanocomposite photoelectrode and polyaniline (PANI) counter electrode
Authors: Ahmed T.O. , Ogunleye O.O. , Abdulrahaman A.Y. , Alu N.
Published: November 2020

We report the successful application of reduced graphene oxide–titania (rGO–TiO2) nanocomposite as an efficient photoelectrode and an inexpensive polyaniline (PANI) synthesized by in-situ polymerization on graphite foam as a platinum substitute for tri-iodide reduction for dye‐sensitized solar cell (DSC). The bulk carrier concentration and conductivity of the PANI was measured to be 3.02x1017cm-3 and 4.89x10-1 W-1cm-1 respectively. Subsequently, three DSCs were assembled with rGO–TiO2 nanocomposite photoelectrode and PANI as counter electrode for one and the other two assembled using unmodified TiO2 photoelectrode with PANI and platinum as counter electrodes, respectively. The rGO loading allows more dye to be adsorbed due its large surface area thus improving the light harvesting efficiency (LHE). This improvement in LHE increases the short circuit current density (JSC). The JSC increase is more substantial compared to the reduction in VOC; thus, the increase in the efficiency of the cell with rGO-TiO2 nanocomposite electrode. The short circuit current density for the rGO-TiO2 DSC with PANI counter electrode is 0.45mAcm-2 while that for the unmodified TiO2 DSCs with PANI counter electrode and platinum counter electrode are 0.11mAcm-2 and 0.10 mAcm-2 respectively. This corresponds to 76% increase in the current density and it increases collection rate at the photoelectrode leading to enhanced power conversion efficiency of 0.13% compared with 0.04% and 0.02% for the DSCs assembled with unmodified TiO2 under full sunlight illumination (100 mW/cm2, AM 1.5G) as a result of the better charge collection efficiency of rGO, which reduces the back electron transfer process. This represent 69% enhancement of energy conversion efficiency in the DSC consisting of rGO modified TiO2
Analysis of uniaxial compression behavior of hollow concrete block masonry: experimental and analytical approaches
Authors: Bui Thi Loan
Published: November 2020

This article focuses on the uniaxial compression behavior of concrete hollow brick masonry assembly. This study was performed both by experimental and analytical approaches. In the first experimental part, the compression tests were done according to the European standard EN1052-1. It is highlighted from the tests that this concrete hollow brick masonry is a very high dispersive material and that the compression behavior of this masonry is similar and depends principally on that of bricks. In addition, the vertical splitting failure modes reflect the effect of "expanding/restraining" for this type of masonry and the elastic properties determined from these tests are comparable with the values found in the literature. Then, in the analytical approach, the simple calculations were done by different existed models to predict the compressive strength of masonry prism. A comparison of the results obtained by using these models with those of experimentation shows that only the model which takes into account the effect of vertical joints is mostly adapted for the safe design of this masonry prism under uniaxial compression load.
A Novel Framework for Context Based Distributed Focused Crawler (CBDFC)
Authors: Gupta Pooja , Sharma Ashok , Gupta J. P. , Bhatia Komal
Published: November 2020

Focused crawling aims to search only the relevant subset of the WWW for a specific topic of user interest; leading to the necessity to decide about the relevancy of a document to the topic of interest; especially when the user is not perfect in specifying the exact context of the topic. This paper provides a novel framework of a context based distributed focused crawler that maintains an index of web documents pertaining to the context of keywords resulting in storage of more related documents.
Intelligent Transport Systems in Commercial Vehicle Operations
Authors: Agrawala Sunil , Kallianpur Harish
Published: November 2020

Intelligent Transportation Systems (ITS) is the application of computers, communications and sensor technology to improve the efficiency or safety of surface transportation systems. The ITS initiative has been taken up by most developed countries including US, Canada, Australia and the European Union. This paper introduces ITS and its vision to save time, money and human lives. ITS can be applied to the entire spectrum of the transportation industry. This includes Freeway, Incident & Emergency Management, Electronic Toll Collection, Arterial Management, Travelers Information Systems, Advanced Public Transportation Systems, Commercial Vehicle Operations, etc. However the primary focus in this paper is on introducing the application of ITS technologies in the realm of Commercial Vehicle Operations (CVO). The paper covers the three major capability areas namely safety information exchange, electronic screening and electronic credentialing, giving details on the ongoing initiatives and the different technologies applied in the respective areas as well as the benefits offered by the same. The ITS initiative has caught up in a big way in the United States. The U.S. Department of Transportation (U.S. DOT) has sponsored and undertaken a program called Commercial Vehicle Information Systems and Networks (CVISN) Model Deployment Initiative (MDI). The goal of the CVISN initiative has been to assist each state in US to achieve "ambitious but achievable" level of deployment of ITS technology in all the three areas of commercial vehicle operations by establishing an organizational framework among state agencies and motor carriers for cooperative system development and creating a CVISN design architecture which can evolve and accommodate new technologies.
Greedy Selection of Materialized Views
Authors: Kumar T.V. Vijay , Ghoshal Aloke
Published: November 2020

Greedy based approach for view selection at each step selects a beneficial view that fits within the space available for view materialization. Most of these approaches are focused around the HRU algorithm, which uses a multidimensional lattice framework to determine a good set of views to materialize. The HRU algorithm exhibits high run time complexity as the number of possible views is exponential with respect to the number of dimensions. The PGA algorithm provides a scalable solution to this problem by selecting views for materialization in polynomial time relative to the number of dimensions. This paper compares the HRU and the PGA algorithm. It was experimentally deduced that the PGA algorithm, in comparison with the HRU algorithm, achieves an improved execution time with lowered memory and CPU usages. The HRU algorithm has an edge over the PGA algorithm on the quality of the views selected for materialization.
Precise Descriptions of VLC Synchronization with CSP Semantic Models
Authors: Fong A.C.M .
Published: November 2020

Variable length codes (VLC) have found widespread applications due to their inherent coding efficiency. However, encoder-decoder synchronization becomes critically important for VLC to operate properly. Traditional treebased techniques lack the scalability to analyse the synchronization behaviours of VLC, and simulation techniques are typically used instead for large code sets. Building on an initial paper in which we first described an application of CSP to this domain, we present further advances in this paper. The contributions of this paper are twofold. First, we describe a novel application of the CSP stable failure model to completely describe the VLC synchronization mechanisms. Consequently, we concisely characterize bit patterns that can bring about rapid synchronization. The overall goal is to advance our understanding in this important area of research through an established formal description technique originally developed and used within the computing research community.
Hardening of UNIX Operating System
Authors: Patra Prof. (Dr.) P.K . , Pradhan P.L.
Published: November 2020

Operating system hardening is the process to address security weaknesses in the operation systems by implementing the latest operating system patches, hot fixes and updates as well as follow up the specific procedures and policies to reduce attacks and system down time.
Empowerment of UMKM in Bone-Bone Village, North Luwu Regency through the Nanda Karya Savings and Loan Cooperative
Authors: Parwati Nunuk , Rifuddin Burhan
Published: November 2020

This research discusses how the efforts to empower UMKM are owned by people who do not have higher education and need business capital through the Nanda Work Savings and Loan Cooperative in Bone-Bone Village, Luwu Utara Regency). The method used is descriptive qualitative research methods, and data sources used primary data through field studies and secondary data through literature studies, with data collection techniques observation, interviews, and documentation. The data analysis technique uses three processes: data reduction, data presentation, and conclusion. Based on the results, it is concluded that the role of the Karya Nanda cooperative in community empowerment helps the government to reduce the number of unemployed and help the community to lend funds as the start of their business capital, as for the obstacles found in cooperative management, namely that there are still many people who invest their capital in outside parties or non-cooperatives.
Factors Influencing the Potential User's Acceptance of Rocab Mobile Application for Public Transportation in Palestine: Insights from Innovation Diffusion Theory and Technology Acceptance Model
Authors: Ajouz Mousa , Salhab Aseel , Idais Aseel
Published: November 2020

This study aimed to investigate the factors that influence the potential user's acceptance of Rocab mobile application for public transportation in Palestine.

This study adopts a quantitative method through 116 electronic questionnaires that developed based on innovation diffusion theory and technology acceptance model. The data were collected based on judgment sampling, which is a purposive sampling technique, meanwhile, partial least squares structural equation modelling (PLS-SEM) analysis was conducted on data elicited from potential users using the Smart-PLS analysis program.

The results showed that 66.3 per cent of the variation in the adoption of Rocab application can be explained by the structural model provided by this research. The results demonstrated that there is a significant effect of relative advantage, compatibility, complexity, and observability on perceived usefulness. The results also showed that the relative advantage, complexity, and observability have a significant effect on perceived ease of use, while compatibility effect on perceived ease of use was found not supported by the collected data. Additionally, perceived usefulness and perceived ease of use were both significantly related to attitude, and, in turn, attitude positively influenced future usage intention to use Rocab application. Overall, it was also found 74.59 per cent of the respondents are willing to use Rocab application in the future.

The originality of this research lies in investigating empirically the factors that influence the potential user's acceptance of Rocab mobile application for public transportation in Palestine which is rare in the literature. This will benefit researchers, the business community as well as policymakers.
The Impact of Applying Lean Manufacturing Fundamentals on the Improvement of Manufacturing Performance: A Case Study at the Yemeni National Company for Sponge and Plastic Industry
Authors: Alhmiari Ali Mohammad Abd Aljbar , Albaheery Abdulwahab Abdulhameed Mohammed Saif
Published: November 2020

The study aimed at investigating the impact of applying lean manufacturing fundamentals on the improvement of manufacturing performance at the Yemeni National Company for Sponge and Plastic Industry (NCSPI). The study adopted the descriptive and analytical approach by using the case study method. A questionnaire was used for collecting data. After analyzing the data, the study findings revealed that there was a significant positive effect for the application of the lean manufacturing fundamentals on improving the manufacturing Performance in the Yemeni National Company for Sponge and Plastic Industry. The fundamentals were ranked in this order: cellular manufacturing; continuous improvement; automatic detection of a defect; and workplace organization. The study recommended that the Yemeni National Company for Sponge and Plastic Industry should give more care to achieve the integration of all Fundamentals of Lean manufacturing for a direct and effective impact on Manufacturing Performance Improvement.
Scant evidence for a volcanically forced winter warming over Eurasia following the Krakatau eruption of August 1883
Authors: Polvani Lorenzo M. , Camargo Suzana J.
Published: November 2020

Abstract. A recent study has presented compelling new evidence suggesting that
the observed Eurasian warming in the winter following the 1992
Pinatubo eruption was, in all likelihood, unrelated to the presence of
volcanic aerosols in the stratosphere. Building on that study, we
turn our attention to the only other low-latitude eruption in the
instrumental period with a comparably large magnitude: the Krakatau
eruption of August 1883. We study the temperature anomalies
in the first winter following that eruption in detail, analyzing (1)
observations, (2) reanalyses, and (3) models. Three findings emerge
from our analysis. First, the observed post-Krakatau winter warming
over Eurasia was unremarkable (only between 1σ and 2σ of the distribution from 1850 to present). Second, reanalyses based on
assimilating surface pressure alone indicate the existence of very
large uncertainties, so much so that a Eurasian cooling is not
incompatible with those reanalyses. Third, models robustly show the
complete absence of a volcanically forced Eurasian winter warming: here, we analyze both a 100-member initial-condition ensemble and 140
simulations from Phase 5 of the Coupled Model Intercomparison Project.
This wealth of evidence strongly suggests that, as in the case of
Pinatubo, the observed warming over Eurasia in the winter of 1883–84
was, in all likelihood, unrelated to the Krakatau eruption. This,
taken together with a similar result for Pinatubo, leads us to
conclude that if volcanically forced Eurasian winter warming exists at
all, an eruption with a magnitude far exceeding these two events would
be needed to produce a detectable surface warming.
Study on variations in lidar ratios for Shanghai based on Raman
lidar
Authors: Liu Tongqiang , He Qianshan , Chen Yonghang , Liu Jie , Liu Qiong , Gao Wei , Huang Guan , Shi Wenhao
Published: November 2020

Abstract. Accurate Lidar ratios (LR) and better understanding of their variation characteristics can not only improve the retrieval accuracy of parameters from elastic lidar, but also play an important role in assessing the impacts of aerosols on the climate. Using the observational data of Raman lidar in Shanghai from 2017 to 2019, the LR at 355 nm were retrieved and their variations and influencing factors were analyzed. Within the height range of 0.5 km–5 km, about 90 % of the LR were distributed in 10 sr–80 sr with an average value of 41.0 ± 22.5 sr, and the LR decreased with the increase of height. The volume depolarization ratios (δ) were positively correlated with LR, and they also decreased with the increase of height, indicating that the vertical distribution of particle shape was one of the influencing factors of the variations of LR with height. LR had a strong dependence on the original source of the air masses. Affected by the aerosol transported from northwest of Shanghai, the average LR was the largest, 44.2 ± 24.7 sr, accompanied by the most irregular particle shape. The vertical distributions of LR were affected by the atmospheric turbidity, with the greater gradient of LR under the clean conditions. The LR above 1 km could be more than 80 sr, when Shanghai was affected by the biomass burning aerosols.
Effectiveness of emission control to reduce PM2.5 pollution of Central China during winter haze episodes under various potential synoptic controls
Authors: Yan Yingying , Zhou Yue , Kong Shaofei , Lin Jintai , Wu Jian , Zheng Huang , Zhang Zexuan , Bai Yongqing , Ling Zhang , Liu Dantong , Zhao Tianliang
Published: November 2020

Abstract. Currently solving the severe particle pollution in autumn and winter is the key to further improve the air quality of China. The source contributions and transboundary transport of fine particles (PM2.5) in pollution episodes are closely related to large-scale or synoptic-scale atmospheric circulation. Under different synoptic conditions, how to effectively reduce emissions to control haze pollution is rarely reported. In this study, we classify the synoptic conditions over Central China from 2013 to 2018 by using Lamb-Jenkension method and the NCEP/NCAR FNL operational global analysis data. The effectiveness of emission control to reduce PM2.5 pollution during winter haze episodes under potential synoptic controls is simulated by GEOS-Chem model. Among the ten identified synoptic patterns, four types account for 87 % of the total pollution days. Two typical synoptic modes of them are characterized by small surface wind speed and stable weather conditions/high relative humidity (A/C-type) over Central China due to a high-pressure system/a southwest trough low-pressure system, blocking pollutants dispersion. Sensitivity simulations show that these two heavy pollution processes are mainly contributed by local emission sources with ~82 % for A-type and ~85 % for C-type, respectively. The other two patterns lead to pollution of transportation characteristics affected by northerly/southerly winds (NW/SW-type), carrying air pollution from northern/southern China to Central China. The contribution of pollution transportation from North/South China is 36.9 %/7.6 % of PM2.5 and local emission sources contribute 41 %/69 %. We also estimate the effectiveness of emission reduction in these four typical severe pollution synoptic processes. By only reducing SO2 and NOx emission and not controlling NH3, the enhanced nitrate counteracts the effect of sulfate reduction on PM2.5 mitigations with less than 4% decrease in PM2.5. In addition, to effectively mitigate haze pollution in NW/SW-type synoptic controlled episodes, local emission control actions should be in coordination with regional collaborative actions.
Applying machine learning methods to detect convection using
GOES-16 ABI data
Authors: Lee Yoonjin , Kummerow Christian D. , Ebert-Uphoff Imme
Published: November 2020

Abstract. An ability to accurately detect convective regions is essential for initializing models for short term precipitation forecasts. Radar data are commonly used to detect convection, but radars that provide high temporal resolution data are mostly available over land and the quality of the data tends to degrade over mountainous regions. On the other hand, geostationary satellite data are available nearly anywhere and in near-real time. Current operational geostationary satellites, the Geostationary Operational Environmental Satellite-16 (GOES-16) and -17 provide high spatial and temporal resolution data, but only of cloud top properties. One-minute data, however, allow us to observe convection from visible and infrared data even without vertical information of the convective system. Existing detection algorithms using visible and infrared data look for static features of convective clouds such as overshooting top or lumpy cloud top surface, or cloud growth that occurs over periods of 30 minutes to an hour. This study represents a proof-of-concept that Artificial Intelligence (AI) is able, when given high spatial and temporal resolution data from GOES-16, to learn physical properties of convective clouds and automate the detection process. A neural network model with convolutional layers is proposed to identify convection from the high-temporal resolution GOES-16 data. The model takes five temporal images from channel 2 (0.65 μm) and 14 (11.2 μm) as inputs and produces a map of convective regions. In order to provide products comparable to the radar products, it is trained against Multi-Radar Multi-Sensor (MRMS), which is a radar-based product that uses rather sophisticated method to classify precipitation types. Two channels from GOES-16, each related to cloud optical depth (channel 2) and cloud top height (channel 14), are expected to best represent features of convective clouds: high reflectance, lumpy cloud top surface, and low cloud top temperature. The model has correctly learned those features of convective clouds, and resulted reasonably low false alarm ratio (FAR) and high probability of detection (POD). However, FAR and POD can vary depending on the threshold, and a proper threshold needs to be chosen based on the purpose.
N2O isotope approaches for source partitioning of N2O production and estimation of N2O reduction – validation with the 15N gas-flux method in laboratory and field studies
Authors: Lewicka-Szczebak Dominika , Lewicki Maciej Piotr , Well Reinhard
Published: November 2020

Abstract. The approaches based on natural abundance N2O stable
isotopes are often applied for the estimation of mixing proportions
between various N2O-producing pathways as well as for
estimation of the extent of N2O reduction to
N2. But such applications are associated with numerous
uncertainties; hence, their limited accuracy needs to be considered.
Here we present the first systematic validation of these methods for
laboratory and field studies by applying the 15N gas-flux
method as the reference approach. Besides applying dual-isotope plots for interpretation of
N2O isotopic data, for the first time we propose a three
dimensional N2O isotopocule model based on Bayesian
statistics to estimate the N2O mixing proportions and
reduction extent based simultaneously on three N2O isotopic
signatures (δ15N, δ15NSP, and
δ18O). Determination of the mixing proportions of
individual pathways with N2O isotopic approaches often appears
imprecise, mainly due to imperfect isotopic separation of the
particular pathways. Nevertheless, the estimation of N2O
reduction is much more robust, when applying an optimal calculation
strategy, typically reaching an accuracy of N2O residual
fraction determination of about 0.15.
Particulate rare earth element behavior in the North Atlantic (GEOVIDE cruise)
Authors: Lagarde Marion , Lemaitre Nolwenn , Planquette Hélène , Grenier Mélanie , Belhadj Moustafa , Lherminier Pascale , Jeandel Catherine
Published: November 2020

Abstract. Particulate concentrations of the 14 Rare Earth Elements (PREE), yttrium, and 232-thorium were measured in 200 samples collected in the epipelagic (ca. 0–200 m) and mesopelagic (ca. 200–1500 m) zones of the North Atlantic during the GEOVIDE cruise (May/June 2014, R/V
Pourquoi Pas?, GEOTRACES GA01), providing the most detailed snapshot of the
PREE distribution in the North Atlantic so far. Concentrations of
particulate cerium (PCe) varied between 0.2 and 16 pmol L−1, while particulate neodymium (PNd) concentrations ranged between
0.1 and 6.1 pmol L−1. Particulate ytterbium (PYb)
concentrations ranged between 0.01 and 0.50 pmol L−1.
In addition, this study showed that PREE distributions were also controlled
by the biological production in the upper sunlit ocean and by
remineralization processes in the mesopelagic area. Low surface
concentrations combined with normalized PREE patterns displaying a negative
Ce anomaly and HREE enrichments pointed to freshly formed biogenic particles
imprinting the seawater signature. A significant relationship between
biogenic silica (BSi) and PHREE was also observed in the Labrador and
Irminger seas, due to the occurrence of strong diatom blooms at the sampling time. In order to identify dissolved-particulate processes independent of
the ionic radius, we used PHo∕PY ratios and showed that absorption processes
were predominant in the upper ocean, while adsorption processes dominated at deeper depths. This study highlighted different lithogenic fractions of PREE and dispersion depending on the shelf: off the Iberian margin, up to 100 % of the PREE were determined to have a lithogenic origin. This lithogenic input spread
westward along an intermediate nepheloid layer (INL), following isopycnals
up to 1700 km away from the margin. In contrast, along the Greenland and
Newfoundland margins, the circulation maintained lithogenic inputs of PREE
along the coasts.
Decoupling salinity and carbonate chemistry: Low calcium ion
concentration rather than salinity limits calcification in Baltic
Sea mussels
Authors: Sanders Trystan , Thomsen Jörn , Müller Jens Daniel , Rehder Gregor , Melzner Frank
Published: November 2020

Abstract. The Baltic Sea has a salinity gradient decreasing from fully marine (> 25) in the West to below 7 in the Central Baltic Proper. Reef forming mytilid mussels exhibit decreasing growth when salinity
Compound high temperature and low chlorophyll extremes in the
ocean over the satellite period
Authors: Le Grix Natacha , Zscheischler Jakob , Laufkötter Charlotte , Rousseaux Cécile S. , Frölicher Thomas L.
Published: November 2020

Abstract. Extreme events severely impact marine organisms and ecosystems. Of particular concern are compound events, i.e., when conditions are extreme for multiple potential ecosystem stressors such as temperature and chlorophyll. Yet, little is known about the occurrence, intensity and duration of such compound high temperature (aka marine heatwaves – MHWs) and low chlorophyll (LChl) extreme events, whether their distributions have changed in the past decades and what the potential drivers are. Here we use satellite-based sea surface temperature and chlorophyll concentration estimates to provide a first assessment of such compound extreme events. We reveal hotspots of compound MHW and LChl events in the equatorial Pacific, along the boundaries of the subtropical gyres, in the northern Indian Ocean, and around Antarctica. In these regions, compound events that typically last one week occur three to seven times more often than expected under the assumption of independence between MHWs and LChl events. The occurrence of compound MHW and LChl events varies on seasonal to interannual timescales. At the seasonal timescale, most compound events occur in summer in both hemispheres. At the interannual time-scale, the frequency of compound MHW and LChl events is strongly modulated by large-scale modes of natural climate variability such as the El Niño-Southern Oscillation, whose positive phase is associated with increased compound event occurrence in the eastern equatorial Pacific and in the Indian Ocean by a factor of up to four. Our results provide a first understanding of where, when and why compound MHW and LChl events occur. Further studies are needed to identify the exact physical and biological drivers of these potentially harmful events in the ocean and their evolution under global warming.
Contribution to the crystal chemistry of lead-antimony sulfosalts: systematic Pb-versus-Sb crossed substitution in the plagionite homologous series, Pb2N − 1(Pb1 − xSbx)2(Sb1 − xPbx)2Sb6S13+2N
Authors: Moëlo Yves , Biagioni Cristian
Published: November 2020

Abstract. The plagionite homologous series contains four well-defined members with the general formula Pb1+2NSb8S13+2N: fülöppite (N=1), plagionite (N=2), heteromorphite (N=3), and semseyite (N=4). The crystal structure of several natural and synthetic samples of fülöppite, plagionite, and semseyite have been refined through single-crystal X-ray diffraction, confirming the systematic Pb-versus-Sb crossed substitution observed previously in semseyite and fülöppite. This crossed substitution takes place mainly in two adjacent cation sites in the middle of the constitutive SnS-type layer. The substitution coefficient x appears variable, even for a given species, with the highest values observed in synthetic fülöppite samples. The developed structural formula of the plagionite homologues can be given as Pb2N−1(Pb1−xSbx)2(Sb1−xPbx)2Sb6S13+2N. In the studied samples, x varies between ∼ 0.10 and 0.40. In the ribbons within the SnS-type layer, (Pb∕Sb) mixing can be considered the result of the combination, in a variable ratio, of two cation sequences, i.e. (Sb–Sb–Sb)–Pb–Sb–(…), major in plagionite and semseyite, and (Sb–Sb–Sb)–Sb–Pb–(…), major in fülöppite and, probably, in heteromorphite. The published crystal structure of synthetic “Pb-free fülöppite” is revised according to this approach. It would correspond to a Na derivative, with a proposed structural formula of (Na0.5Sb0.5)(Na0.2Sb0.8)2(Na0.3Sb0.7)2Sb6S15, ideally Na1.5Sb9.5S15. In fülöppite, increasing x induces a flattening of the unit cell along c, with a slight volume decrease. Such a general Pb-versus-Sb crossed substitution would attenuate steric distortions in the middle of the SnS-type layer of the plagionite homologous series. Crystallization kinetics seem the main physical factor that controls such an isochemical substitution.
ESD Ideas: Long-period tidal forcing in geophysics – application to
ENSO, QBO, and Chandler wobble
Authors: Pukite Paul R.
Published: November 2020

Abstract. Apart from its known impact to variations in the Earth's length-of-day (LOD) variations, the role of long-period tidal forcing cycles in geophysical behaviours has remained relatively unexplored. To extend this idea, tidal forcing is considered as a causative mechanisms to the following cyclic processes: El Niño Southern Oscillation (ENSO), Quasi-Biennial Oscillation (QBO), and the Chandler wobble. Subtle mathematical insights are required to make the connection to the observed patterns as the underlying periods are not strictly commensurate in relation to harmonics of the tidal cycles. There are three cyclic perturbations in the Earth's behavior that scientists have had difficulty pinning down. The actual understanding is so poor that there is no clear consensus for any of the behaviors, and the actual mechanism in each is considered an as-yet unresolved mystery. One behavior has to do with an oceanic cycle (ENSO), one with an atmospheric cycle (QBO), and one with the solid Earth (Chandler wobble). A consensus agreement is lacking in each of these three behaviors in spite of the fact that there may be an obvious yet mathematically-challenging common-mode cause tying them together. The challenge lies in simplifying the math of fluid dynamics and applying the appropriate signal processing techniques. With that, an elegant analytical framework can be applied to perhaps solve the mystery once and for all.