bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Thermomechanical Treatment Modes on Wear Resistance of Mining Equipment Material
Authors: Chupin S. , Bolobov V.
Published: February 2019

This work presents results of experimental researches of influence of various high-temperature thermomechanical treatment (HTMT) modes in 35KhGSA steel – material applied in rock-destroying cutters – on hardness and wear rate for the most common abrasive rock in mining operations – sandstone. It has been found out that HTMT leads to increase of steel hardness and reduction of wear rate compared to heat treatment applied at manufacture of cutters. The maximal increase of hardness (by 23%) and reduction of wear rate (by 38%) corresponds to the mode of distortion accumulation of ~1,5 at 900 °С at water quenching and tempering at 230 °C. A conclusion that thermomechanical treatment is an effective way to increase the wear resistance of steels applied in the conditions of abrasion wear has been drawn.
Influence of Zirconia Powder Fractional Composition on Microstructure and Properties of Thermal Barrier Coating Obtained by Thermal Spraying
Authors: Hristosova V.Yu. , Bondareva O. S. , Konovalov Sergey V.
Published: February 2019

Thermal spraying is one of the most promising methods for obtaining thermal barrier coatings for aerospace applications. Providing the necessary set of coating properties and their stable reproducibility are an actual task of the modern production. The purpose of this work was to determine the influence of the initial powders fractional composition on the structure and properties of the protective coating. The microstructure and the elemental composition features of the heat-resistant and ceramic layers of the thermal barrier coating are investigated. It is shown that the microstructure, porosity and microhardness of the coating ceramic layer depend on the ZrO2+8%Y2O3initial powder fractional composition. The porosity of the coating and the average pore size increase with increasing particle size of the powder. The maximum value of the ceramic layer microhardness is observed when using a powder fraction of 40-80 μm. The studies have found that microstructure and the necessary combination of coating physical and mechanical properties are achieved during the deposition of zirconia powder fractions 40-80 microns.
Protective Coating Based on Siloxane Polymer Nanopatterned by Alkoxytitanate
Authors: Chukhlanov V.Y. , Selivanov O.G. , Chukhlanova N.V.
Published: February 2019

The paper considers the problems of creating new protective coatings based on organosilicon polymer – polymethylphenylsiloxane, modified with tetraisopropyltitanate. The mechanisms of siloxane polymer nanostructuring have been suggested. The coating surface nanostructure and the impact of material components content and nature on its properties have been studied. To research protective surface nanostructure, the method of atomic-force probe microscopy applying IntegraAura device has been used. Nanoparticles formations with 10-20 nm effective scale have been revealed. Adhesive properties of the protective coating have been studied. Glass and metal adhesion was determined applying the method of detachment from the steel discs substrate using adhesive meter PSO-MG4. The modification was stated not to cause any substantial loss of coating adhesive properties. Simultaneously modification process was accompanied with the increase of relative coating firmness.The developed compounds and corresponding coatings are aimed at protecting buildings and constructions against negative impact of natural and anthropogenic factors.
Effect of Granulometric Component Composition in Cellular Concrete on Cement Consumption Rate
Authors: Vesova L.M.
Published: February 2019

The use of local natural and technogenic raw materialsallows expansion of the raw material base for producing the building materials and reduction of production cost. Creation of low energy-intensive technologies for producing the building materials is a priority for the construction industry. The chemical and mineralogical composition of industrial wastes makes it possible to use them for producing the low-clinker or clinker-free composite binders. Secondary resources can be used as an active mineral additive that would allow to reduce the cement consumption. The properties of cellular concrete depend on the formed cement matrix structure, the strength of the inter-pore partitions. Quality can be managed by directional formation of the mechanical framework. Providing the necessary granulometric composition of the cellular concrete components is decisive for the mechanical framework formation. The inter-pore partition structure in the cellular concrete is a developed silicate matrix formed by hydration products and a siliceous component. Therefore, when designing this structure, an analogy with ordinary dense concrete is quite possible. The basic principle for designing the concrete composition consists in creating a dense packaging of the constituent components.
Prediction of the Mechanical Characteristics of Reinforced Thermoplastic Composite Materials Used in Aviation
Authors: Anoshkin A.N. , Pisarev Pavel V. , Shipunov G.S.
Published: February 2019

Within the framework of the present work, the results of calculation and experimental studies of the mechanical characteristics of textile composites with a thermoplastic matrix are presented. A software module and a numerical model for calculating the effective elastic characteristics of composite materials with a thermoplastic matrix are developed. At the heart of the developed software module implemented in the engineering package ANSYS, the method of averaging by volume, integrated into ANSYS Mechanical, is applied. Based on the results of numerical experiments, effective elastic characteristics for a periodicity cell with an interlacing of 5H Satin and a layered composite material were determined. The verification of the developed numerical models has been carried out.
Structural Analysis of Factors Influencing the Functionality of Subgrade of Transport Constructions
Authors: Dukhovny G. , Zolotykh S. , Bodyakov A.
Published: February 2019

Railway and highway subgrade is considered to be one of the most vulnerable elements of transport structures. Undoubtedly, its failure may cause serious delays or even traffic interruption. Moreover, subgrade reliability is affected by various material, technological, climatic, as well as, soil-related and geological factors. This paper presents the results of a structural analysis with impact matrix cross-reference multiplication applied to a classification (MICMAC) technique applied for the identification of the most essential factors based on the intensity of their influence on each other. By doing so, an opinion survey was undertaken through expert consultations with industry and academic representatives in the field of construction materials, design, construction and operation of railways and roads in order to increase the subgrade effectiveness and reliability. Based on the outcomes of the derived structural analysis, it can be concluded that the following factors are the most influential: strength, water and physical properties of the top subgrade layer material; optimal subgrade soil moisture monitoring during its maintenance; and construction management of subgrade. Targeted control of the mentioned factors in general, and the top subgrade layer properties in particular, mainly depends on the properties of applied materials. This condition is generic, regardless of a region where railways and roads are being operated.
Investigation of the Influence of the Location of the Unified Mass on the Formed Vibrations of a Thin Containing Extended Shell
Authors: Sysoev O.E. , Dobryshkin A.Y. , Naing Nyein Sit , Baenkhaev A.V.
Published: February 2019

The operation of a structure of thin-walled open cylindrical shells with high economic efficiency is associated with the phenomenon of oscillations and resonance from the effects of cyclic loads and systems of attached masses. The oscillation processes of such structures are not sufficiently studied at present. The article describes a test bench for testing open thin-walled cylindrical shells hinged on the edges that carry a system of attached masses, and the results of experiments on the nature of a reduced-scale shell model are presented. The attached mass system represents metal cylinders of different masses arranged in a certain sequence on the shell body. The experimental dependence of the change in the frequency spectrum of the shell oscillations on the number, mass, and location of the system of attached masses is obtained. A mathematical model is developed for the behavior of an open thin-walled cylindrical shell with a system of attached masses, consistent with the experimental data for forced vibrations of the shell.
Application of Nonwoven Geosynthetic Materials in Construction in Wetlands
Authors: Karpushko Marina O. , Bartolomei Igor L. , Karpushko Elena N. , Zhidelev A.V.
Published: February 2019

The article contains the results of research on the development of optimal in terms of time and complexity of work, energy intensity, consumption of materials and cost, the design of the roadbed for use in the construction of oilfield roads in wetlands. Trunk oil and gas pipelines in Western Siberia and north of the European part of Russia began to be built approximately from the mid-1960s. From the very beginning, designers faced serious problems: complex natural and heavy ground and hydro geological conditions, namely, permafrost soils and swamps. The length of the swamp sections is tens and hundreds of meters, and in some cases – tens of kilometers. Road construction in wetlands is a very difficult engineering task. Conditions of excessive moisture, extremely low load-carrying capacity of marsh soils, a characteristic deficiency of quality mineral materials - all this creates obstacles, the overcoming of which is associated with significant material costs. The average cost of road construction through the swamp is 3-5 times higher than in normal conditions. A constructive solution for the roadbed using a layer of non-woven synthetic material in the cage to ensure year-round and uninterrupted movement of technological transport for maintenance of oil facilities was chosen.
Electron-Induced Effects at Diagnostics and Modification of Ferroelectrics: Mathematical Modelling, Simulation and Optimal Control
Authors: Maslovskaya Anna , Pavelchuk A.
Published: February 2019

The paper is devoted to developing the theoretical basis of the mathematical modelling and computer simulation intended to analyze and control the electron beam-stimulated effects in ferroelectric materials. In order to simulate the electron beam-induced charging dynamics of ferroelectrics the modification of drift-reaction-diffusion model was proposed. The calculation was based on the numerical solution of the continuity equation and Poisson equation. The parameters of the electron irradiation doze and source function were estimated by 3D Monte-Carlo simulation of electron trajectories in the solid specimen. The computation was associated with typical ferroelectrics (LiNbO3, LiTaO3) irradiated by intermediate-energy electron bunches specified for SEM. The contribution roles of drift component as well as diffusion component during dynamic charging process were discussed. The simulation results enable us to predict charge distribution, dynamic of the potential distribution, electric field and electron beam-induced component of polarization at the given experimental parameters. These findings can be used to control polarization switching in ferroelectrics electron beam-irradiated by the SEM techniques.
The Roller Press Required Spreading Force Determination for Obtaining High-Quality Briquettes from Pulverized-Coal Waste of Blast Furnaces
Authors: Shishkin E.A. , Ivanchenko S.N.
Published: February 2019

The briquetted material and pressing surfaces force interaction is considered in the deformation center pressing zone. The investigated material is considered as an elastoplastic medium, described by rheological model: Bingham's body, which most fully reflects the physical medium under study properties. The material stress-strain state is divided into two stages: ideal-elastic and elastoplastic, each described by the obtained equation. Parameters of the force impact of the material on the pressure rolls depending on material physicomechanical characteristics and a press geometrical parameters are obtained.
Cutting Edge: Core Binding Factor β Is Required for Group 2 Innate Lymphoid Cell Activation
Authors: Shen Xiaofei , Liang Mingwei , Chen Xiangyu , Pasha Muhammad Asghar , D’Souza Shanti S. , Hidde Kelsi , Howard Jennifer , Sultana Dil Afroz , Fung Ivan Ting Hin , Ye Longyun , Pan Jiexue , Liu Gang , Drake James R. , Drake Lisa A. , Zhu Jinfang , Bhandoola Avinash , Yang Qi
Published: February 2019

Group 2 innate lymphoid cells (ILC2) are tissue-resident, long-lived innate effector cells implicated in allergy and asthma. Upon activation, mature ILC2 rapidly secrete large amounts of type-2 cytokines and other effector molecules. The molecular pathways that drive ILC2 activation are not well understood. In this study, we report that the transcriptional controller core binding factor β (CBFβ) is required for ILC2 activation. Deletion or inhibition of CBFβ did not impair the maintenance of ILC2 at homeostasis but abolished ILC2 activation during allergic airway inflammation. Treatment with CBFβ inhibitors prevented ILC2-mediated airway hyperresponsiveness in a mouse model of acute Alternaria allergen inhalation. CBFβ promoted expression of key ILC2 genes at both transcriptional and translational levels. CBF transcriptional complex directly bound to Il13 and Vegfa promoters and enhancers, and controlled gene transcription. CBFβ further promoted ribosome biogenesis and enhanced gene translation in activated ILC2. Together, these data establish an essential role for CBFβ in ILC2 activation.
High-Dimensional Mass Cytometric Analysis Reveals an Increase in Effector Regulatory T Cells as a Distinguishing Feature of Colorectal Tumors
Authors: Norton Samuel E. , Ward-Hartstonge Kirsten A. , McCall John L. , Leman Julia K. H. , Taylor Edward S. , Munro Fran , Black Michael A. , Fazekas de St. Groth Barbara , McGuire Helen M. , Kemp Roslyn A.
Published: February 2019

T cell infiltration of tumors plays an important role in determining colorectal cancer disease progression and has been incorporated into the Immunoscore prognostic tool. In this study, mass cytometry was used to demonstrate a significant increase in the frequency of both conventional CD25+FOXP3+CD127lo regulatory T cells (Tregs) as well as BLIMP-1+ Tregs in the tumor compared with nontumor bowel (NTB) of the same patients. Network cluster analyses using SCAFFoLD, VorteX, and CITRUS revealed that an increase in BLIMP-1+ Tregs was a single distinguishing feature of the tumor tissue compared with NTB. BLIMP-1+ Tregs represented the most significantly enriched T cell population in the tumor compared with NTB. The enrichment of ICOS, CD45RO, PD-1, PDL-1, LAG-3, CTLA-4, and TIM-3 on BLIMP-1+ Tregs suggests that BLIMP-1+ Tregs have a more activated phenotype than conventional Tregs and may play a role in antitumor immune responses.
Failure mechanism of an ancient landslide at Low, Quebec
Authors: Wang B
Published: February 2019

This Open File presents a geotechnical study of a Champlain Sea clay landslide near the municipality of Low, Quebec. The landslide is one of 12 landslides identified from previous studies to have been triggered by an earthquake about 1020 cal yr BP. Geotechnical
studies were conducted to investigate the failure mechanism of the landslide. This is one of three landslides investigated for the purpose of estimating the minimum magnitude of the earthquake. Field tests were conducted in and around the landslide zone. Micro-seismic surveys at 27 locations
indicate the sediment thickness ranging from 10 m to 44 m below the current surface. Cone Penetrometer Tests (CPT) at four locations confirmed the micro-seismic measurements to be fairly accurate. The CPT tip resistance data were calibrated with field Vane Shear Test (VST) results. The soil peak
undrained shear strength (Cu) is found to correlate with depth (H) from the original Champlain Sea surface as Cu = 28 + 1.42H. The test results and other information indicate that the 1020 cal yr BP landslide likely occurred inside a larger landslide zone of a much older age. The landslide is likely
a flake type failure based on the data collected and by comparison with other cases. A slope model is constructed for stability analysis to determine the threshold ground acceleration required to trigger the failure. The resulting minimum horizontal ground acceleration is 0.19
g.
O Olhar do Agente Educador sobre a Constituição Psíquica de Crianças Acolhidas
Authors: Omizzollo Poliana , Silva Milena Da Rosa
Published: February 2019

Este estudo visa compreender, através do olhar de agentes educadores de instituições que acolhem crianças separadas de suas mães, como aquelas se constituem psiquicamente, tendo em vista a relevância da função materna para o desenvolvimento emocional do bebê. A partir da perspectiva dos agentes, refletimos sobre as possibilidades de desenvolvimento que cada criança encontra ao deparar-se privada da convivência com sua família de origem e acolhida em uma instituição. Assim, foram realizadas entrevistas com quatro profissionais que atuam diretamente no cuidado de bebês e crianças pequenas que se encontram em abrigos de Porto Alegre, e analisadas vinhetas de um caso clínico que impulsionou este escrito. A abordagem realizada possibilitou a compreensão de diversos fatores implicados na árdua tarefa do vir a ser enquanto sujeito no âmbito de uma instituição de acolhimento, enfatizando as possibilidades que irrompem quando consideramos um espaço para a escuta clínica. Percebemos, assim, que um vínculo calcado na confiança e na confiabilidade é possível, mas que, geralmente, encontra-se emaranhado por entre as dificuldades inerentes à função.
A Não Relação Sexual Lacaniana em face do Debate entre Gênero e Diferença Sexual
Authors: Cossi Rafael Kalaf
Published: February 2019

Este trabalho tem por finalidade examinar certa faceta da polêmica que gira em torno dos termos diferença dos sexos, gênero e diferença sexual em repercussão no campo psicanalítico. Inicialmente, versa sobre a incorporação de gender como instrumento da pesquisa sobre a sexualidade efetuada por Robert Stoller. Sua tese a respeito do núcleo de identidade de gênero foi analisada por Judith Butler e serviu-lhe de contraponto para o desenvolvimento de sua noção de performatividade de gênero. Acompanhamos a polêmica concernente à noção de diferença sexual em psicanálise. Se, por um lado, é interpretada pelos estudos de gênero como mantenedora duma norma binária que é avessa à multiplicidade; por outro, tem o mérito de resguardar o termo sexo, justamente este que é excluído do espectro contemplado por gênero e é exaltado pelo feminismo francês. Constatamos que a proposição stolleriana também foi criticada por Jacques Lacan no contexto de sua elaboração da noção de semblante do seminário XVIII, que prevê uma espécie de relação entre os sexos. Por fim, defendemos que Lacan não recorre à diferença sexual nem a gênero visando defini-los, mas entra nesse debate privilegiando a relação entre um sexo e outro enquanto impossível, concepção que é subsumida na expressão diferença dos sexos e que foi tema tratado extensamente e com grande rigor de formalização em sua teoria da sexuação.
Semelhanças e Especificidades entre os Estudos do Ócio e os Estudos do Lazer
Authors: Maciel Marcos Gonçalves , Saraiva Luiz Alex Silva , Martins José Clerton Oliveira
Published: February 2019

As concepções teóricas dos estudos do ócio e dos estudos do lazer apresentam semelhanças e especificidades quanto à análise dos fenômenos culturais. Assim, o objetivo deste trabalho é analisar essas duas perspectivas considerando suas abordagens conceituais. Para tanto, conduzimos uma pesquisa bibliográfica, por meio de uma revisão narrativa. As análises realizadas indicam que há distinções referentes aos aspectos filosófico, ontológico, epistemológico, axiológico e temporal. Todavia, apresentam similaridade em relação à subjetividade/atitude e à intervenção pedagógica. Embora singulares, ambas as áreas podem estabelecer um dialogismo para a construção de conhecimentos que compreendam os fenômenos sociais do ócio e do lazer enquanto desenvolvimento pessoal e coletivo.
The 2015–2016 Carbon Cycle As Seen from OCO-2 and the Global In Situ Network
Authors: Crowell Sean , Baker David , Schuh Andrew , Basu Sourish , Jacobson Andrew R. , Chevallier Frederic , Liu Junjie , Deng Feng , Feng Liang , Chatterjee Abhishek , Crisp David , Eldering Annmarie , Jones Dylan B. , McKain Kathryn , Miller John , Nassar Ray , Oda Tomohiro , O'Dell Christopher , Palmer Paul I. , Schimel David , Stephens Britton , Sweeney Colm
Published: February 2019

Abstract. The Orbiting Carbon Observatory-2 has been on orbit since 2014, and its global coverage holds the potential to reveal new information about the carbon cycle through the use of top-down atmospheric inversion methods combined with column average CO2 retrievals. We employ a large ensemble of atmospheric inversions utilizing different transport models, data assimilation techniques and prior flux distributions in order to quantify the satellite-informed fluxes from OCO-2 Version 7r land observations and their uncertainties at continental scales. Additionally, we use in situ measurements to provide a baseline against which to compare the satellite-constrained results. We find that within ensemble spread, in situ observations and satellite retrievals constrain a similar global total carbon sink of 3.7 ± 0.5 PgC, and 1.5 ± 0.6 PgC per year for global land, for the 2015–2016 annual mean. This agreement breaks down on smaller regions, and we discuss the differences between the experiments. Of particular interest is the difference between the different assimilation constraints in the tropics, with the largest differences occurring in tropical Africa, which could be an indication of the global perturbation from the 2015–2016 El Niño. Evaluation of posterior concentrations using TCCON and aircraft observations gives some limited insight into the quality of the different assimilation constraints, but the lack of such data in the tropics inhibits our ability to make strong conclusions there.
X-band dual-polarization radar-based hydrometeor classification for Brazilian tropical precipitation systems
Authors: Ribaud Jean-François , Machado Luiz Augusto Toledo , Biscaro Thiago
Published: February 2019

Abstract. The dominant hydrometeor types associated with Brazilian tropical
precipitation systems are identified via research X-band dual-polarization
radar deployed in the vicinity of the Manaus region (Amazonas) during both
the GoAmazon2014/5 and ACRIDICON-CHUVA field experiments. The present study
is based on an agglomerative hierarchical clustering (AHC) approach that
makes use of dual polarimetric radar observables (reflectivity at horizontal
polarization ZH, differential reflectivity ZDR, specific
differential-phase KDP, and correlation coefficient ρHV) and
temperature data inferred from sounding balloons. The sensitivity of the
agglomerative clustering scheme for measuring the intercluster
dissimilarities (linkage criterion) is evaluated through the wet-season
dataset. Both the weighted and Ward linkages exhibit better abilities to
retrieve cloud microphysical species, whereas clustering outputs associated
with the centroid linkage are poorly defined. The AHC method is then applied
to investigate the microphysical structure of both the wet and dry seasons.
The stratiform regions are composed of five hydrometeor classes: drizzle,
rain, wet snow, aggregates, and ice crystals, whereas convective echoes are
generally associated with light rain, moderate rain, heavy rain, graupel,
aggregates, and ice crystals. The main discrepancy between the wet and dry
seasons is the presence of both low- and high-density graupel within
convective regions, whereas the rainy period exhibits only one type of
graupel. Finally, aggregate and ice crystal hydrometeors in the tropics are
found to exhibit higher polarimetric values compared to those at
midlatitudes.
A new method to determine the aerosol optical properties from multiple wavelength O4 absorptions by MAX-DOAS observation
Authors: Xing Chengzhi , Liu Cheng , Wang Shanshan , Hu Qihou , Liu Haoran , Tan Wei , Zhang Wenqiang , Li Bo , Liu Jianguo
Published: February 2019

Abstract. Ground based Multi-AXis Differential Optical Absorption Spectroscopy (MAX-DOAS) observation was carried out from November 2016 to February 2017 in Beijing, China to measure the O4 absorptions in UV and visible bands and further to illustrate its relationship with aerosol optical properties (AOPs) under different the weather types. According to relative humidity, visibility and PM2.5, we classified the observation periods into clear, non-haze, haze, heavy-haze, fog and rainy five different weather conditions. There are obvious differences for measured AOPs under different weather conditions, especially scattering coefficient (σsca) and absorption coefficient (σabs). It was also found that both the O4 Differential Slant Column Densities (DSCDs) at UV and visible bands varied in the order of clear days > non-haze days > haze days > heavy-haze days > fog days. The correlation coefficients (R2) between O4 DSCDs at 360.8 and 477.1 nm mainly varied in the order of clear days > non-haze days > haze days > heavy-haze days. Based on the statistics of O4 DSCDs at elevation angle 1o with the corresponding linear regression between UV and visible bands of segmental periods, the relationships between O4 DSCDs and AOPs were established. It mainly should be clear or non-haze days when the correlation slope is greater than 1.0, correlation coefficient (R2) greater than 0.9 and O4 DSCDs mainly greater than 2.5 × 1043 molec cm−2. Meanwhile, σsca and σabs are less than 45 and 12 Mm−1, respectively. For haze or heavy-haze days, the correlation slope is less than 0.6, R2 less than 0.8 and O4 DSCDs mainly less than 1.3 × 1043 molec cm−2, under which σsca and σabs are mainly located at 200–900 and 20–60 Mm−1. Additionally, the determination method was well validated based on another MAX-DOAS measurement at Gucheng from 19 to 27 November 2016. For more precise and accurate inversion of AOPs, more detailed look-up tables for O4 multiple wavelength absorptions need to developed. Furthermore, the vertical spatial-resolved aerosol scattering and absorption information is worthy of being expected by using DSCDs at different elevation angles.
Carbon balance of a restored and cutover raised bog: implications for restoration and comparison to global trends
Authors: Swenson Michael M. , Regan Shane , Bremmers Dirk T. H. , Lawless Jenna , Saunders Matthew , Gill Laurence W.
Published: February 2019

Abstract. The net ecosystem
exchange (NEE) and methane (CH4) flux were measured by chamber
measurements for five distinct ecotypes (areas with unique eco-hydrological
characteristics) at Abbeyleix Bog in the Irish midlands over a 2-year
period. The ecotypes ranged from those with high-quality peat-forming
vegetation to communities indicative of degraded, drained conditions. Three
of these ecotypes were located in an area where peat was extracted by hand
and then abandoned and left to revegetate naturally at least 50 years prior
to the start of the study. Two of the ecotypes were located on an adjacent
raised bog, which although never mined for peat, was impacted by shallow
drainage and then restored (by drain blocking) 6 years prior to the start of
the study. Other major aspects of the carbon (C) balance, including dissolved
organic carbon (DOC), dissolved inorganic carbon (DIC), and open-water
CO2 evasion, were quantified for a catchment area at the study site
over the same 2-year period. The ecotype average annual ecotype C balance
ranged from a net C sink of -58±60 g C m−2 yr−1,
comparable to studies of intact peatlands, to a substantial C source of +205±80 g C m−2 yr−1, with NEE being the most variable component
of the C balance among the five ecotypes. Ecotype annual CH4 flux ranged from 2.7±1.4 g C-CH4 m−2 yr−1 to 14.2±4.8 g C-CH4 m−2 yr−1. Average annual aquatic C
losses were 14.4 g C m−2 yr−1
with DOC, DIC, and CO2 evasion of 10.4 g C m−2 yr−1,
1.3 g C m−2 yr−1, and 2.7 g C m−2 yr−1, respectively.
A statistically significant negative correlation
was found between the mean annual water table (MAWT) and the plot-scale NEE
but not the global warming potential (GWP). However, a significant negative
correlation was observed between the plot-scale percentage of Sphagnum moss cover and the
GWP, highlighting the importance of regenerating this keystone genus as a
climate change mitigation strategy in peatland restoration. The data from
this study were then compared to the rapidly growing number of peatland C
balance studies across boreal and temperate regions. The trend in NEE and
CH4 flux with respect to MAWT was compared for the five ecotypes in
this study and literature data from degraded/restored/recovering peatlands,
intact peatlands, and bare peat sites.
Multi-source global wetland maps combining surface water imagery and groundwater constraints
Authors: Tootchi Ardalan , Jost Anne , Ducharne Agnès
Published: February 2019

Abstract. Many maps of open water and wetlands have been developed based on three main
methods: (i) compiling national and regional wetland surveys,
(ii) identifying inundated areas via satellite imagery and (iii) delineating
wetlands as shallow water table areas based on groundwater modeling. However,
the resulting global wetland extents vary from 3 % to 21 % of the
land surface area because of inconsistencies in wetland definitions and
limitations in observation or modeling systems. To reconcile these
differences, we propose composite wetland (CW) maps, combining two classes of
wetlands: (1) regularly flooded wetlands (RFWs) obtained by overlapping
selected open-water and inundation datasets; and (2) groundwater-driven
wetlands (GDWs) derived from groundwater modeling (either direct or
simplified using several variants of the topographic index). Wetlands are
statically defined as areas with persistent near-saturated soil surfaces
because of regular flooding or shallow groundwater, disregarding most human
alterations (potential wetlands). Seven CW maps were generated at 15 arcsec
resolution (ca. 500 m at the Equator) using geographic information system
(GIS) tools and by combining one RFW and different GDW maps. To validate this
approach, these CW maps were compared with existing wetland datasets at the
global and regional scales. The spatial patterns were decently captured, but
the wetland extents were difficult to assess compared to the dispersion of
the validation datasets. Compared with the only regional dataset encompassing
both GDWs and RFWs, over France, the CW maps performed well and better than
all other considered global wetland datasets. Two CW maps, showing the best
overall match with the available evaluation datasets, were eventually
selected. These maps provided global wetland extents of 27.5 and
29 million km2, i.e., 21.1 % and 21.6 % of the global land area,
which are among the highest values in the literature and are in line with
recent estimates also recognizing the contribution of GDWs. This wetland
class covers 15 % of the global land area compared with 9.7 % for RFW
(with an overlap of ca. 3.4 %), including wetlands under canopy and/or
cloud cover, leading to high wetland densities in the tropics and small
scattered wetlands that cover less than 5 % of land but are highly
important for hydrological and ecological functioning in temperate to arid
areas. By distinguishing the RFWs and GDWs based globally on uniform
principles, the proposed dataset might be useful for large-scale land surface
modeling (hydrological, ecological and biogeochemical modeling) and
environmental planning. The dataset consisting of the two selected CW maps
and the contributing GDW and RFW maps is available from PANGAEA at
https://doi.org/10.1594/PANGAEA.892657 (Tootchi et al., 2018).
A decade of detailed observations (2008–2018) in steep bedrock permafrost at Matterhorn Hörnligrat (Zermatt, CH)
Authors: Weber Samuel , Beutel Jan , Da Forno Reto , Geiger Alain , Gruber Stephan , Gsell Tonio , Hasler Andreas , Keller Matthias , Lim Roman , Limpach Philippe , Meyer Matthias , Talzi Igor , Thiele Lothar , Tschudin Christian , Vieli Andreas , Vonder Mühll Daniel , Yücel Mustafa
Published: February 2019

Abstract. The PermaSense project is an ongoing interdisciplinary effort between geo-science and engineering disciplines started in 2006 with the goals to make observations possible that previously have not been possible. Specifically the aims are to obtain measurements data in unprecedented quantity and quality based on technological advances. This paper describes a unique ten+ year data record obtained from in-situ measurements in steep bedrock permafrost in an Alpine environment on the Matterhorn Hörnligrat, Zermatt Switzerland at 3500 m a.s.l. Through the utilization of state-of-the-art wireless sensor technology it was possible to obtain more data of higher quality, make this data available in near real-time and tightly monitor and control the running experiments. This data set (DOI: https://doi.org/10.1594/PANGAEA.897640, Weber et al., 2019a) constitutes the longest, densest and most diverse data record in the history of mountain permafrost research worldwide with 17 different sensor types used at 29 distinct sensor locations consisting of over 114.5 million data points captured over a period of ten+ years. By documenting and sharing this data in this form we contribute to making our past research reproducible and facilitate future research based on this data e.g. in the area of analysis methodology, comparative studies, assessment of change in the environment, natural hazard warning and the development of process models.
Aging of basalt volcanic systems and decreasing CO2 consumption by weathering
Authors: Börker Janine , Hartmann Jens , Romero-Mujalli Gibran , Li Gaojun
Published: February 2019

Abstract. Basalt weathering is one of many relevant processes balancing the global
carbon cycle via land–ocean alkalinity fluxes. The CO2 consumption by
weathering can be calculated using alkalinity and is often scaled with
runoff and/or temperature. Here, it is tested if the surface age distribution
of a volcanic system derived by geological maps is a useful proxy for
changes in alkalinity production with time. A linear relationship between temperature normalized alkalinity fluxes and
the Holocene area fraction of a volcanic field was identified using
information from 33 basalt volcanic fields, with an r2=0.93. This
relationship is interpreted as an aging function and suggests that fluxes
from Holocene areas are ∼10 times higher than those from old
inactive volcanic fields. However, the cause for the decrease with time is
probably a combination of effects, including a decrease in alkalinity
production from material in the shallow critical zone as well as a decline
in hydrothermal activity and magmatic CO2 contribution. The addition of
fresh reactive material on top of the critical zone has an effect in young
active volcanic settings which should be accounted for, too. A comparison with global models suggests that global alkalinity fluxes
considering Holocene basalt areas are ∼60 % higher than the
average from these models imply. The contribution of Holocene areas to the
global basalt alkalinity fluxes is today however only ∼5 %,
because identified, mapped Holocene basalt areas cover only ∼1 %
of the existing basalt areas. The large trap basalt proportion on the
global basalt areas today reduces the relevance of the aging effect.
However, the aging effect might be a relevant process during periods of
globally intensive volcanic activity, which remains to be tested.
Integration of remote sensing and geographic information systems for geological fault detection on the island of Crete, Greece
Authors: Elhag Mohamed , Alshamsi Dalal
Published: February 2019

Abstract. Fracture systems are of great importance in the field of structural geology.
Faults commonly afford easy passage to groundwater and fluids such as
hydrothermal fluids and magmas or even contribute to earthquake hazard
monitoring. For a geologist, it is not always easy to discern such
morphotectonic structures at close range. Both remote sensing techniques and
spatial modeling permit the recognition and better understanding of the
brittle tectonics in an area. This study was an effort to delineate the
tectonic structures on Crete by combining Sentinel-2 satellite
data and spatial data. For the enhancement and better discrimination of
photolineaments primarily recognized on satellite imagery, a variety of
enhancement techniques has been applied. The evaluation of a photolineament
as a potential fracture zone was based on several factors: the DEM of the
study area, the shaded relief, the slopes and corresponding aspects, the
drainage network, the geology and general observations on vegetative coverage
appearance. The application of these methods revealed several fracture zones,
which we recommend be certified by field investigations. Fault-mapping
results may be used for a variety of geological and hydrogeological studies.
Indicative places of a large concentration of groundwater are of vital
importance for subsequent exploitation by areas of need. The present work may
provide useful information for further analysis by geophysicists and
seismologists.
Land surface model photosynthesis and parameter calibration for boreal sites with adaptive population importance sampler
Authors: Mäkelä Jarmo , Knauer Jürgen , Aurela Mika , Black Andrew , Heimann Martin , Kobayashi Hideki , Lohila Annalea , Mammarella Ivan , Margolis Hank , Markkanen Tiina , Susiluoto Jouni , Thum Tea , Viskari Toni , Zaehle Sönke , Aalto Tuula
Published: February 2019

Abstract. We calibrated the JSBACH model with six different stomatal conductance formulations using measurements from 10 FLUXNET coniferous evergreen sites in the Boreal zone. The parameter posterior distributions were generated by adaptive population importance sampler and the optimal values by a simple stochastic optimisation algorithm. The observations used to constrain the model are evapotranspiration (ET) and gross primary production (GPP). We identified the key parameters in the calibration process. These parameters control the soil moisture stress function and the overall rate of carbon fixation. We were able to improve the coefficient of determination and the model bias with all stomatal conductance formulations. There was no clear candidate for the best stomatal conductance model, although certain versions produced better estimates depending on the examined variable (ET, GPP) and the used metric. We were also able to significantly enhance the model behaviour during a drought event in a Finnish Scots pine forest site. The JSBACH model was also modified to use a delayed effect of temperature for photosynthetic activity. This modification enabled the model to correctly time and replicate the springtime increase in GPP (and ET) for conifers throughout the measurements sites used in this study.
Regionally refined capability in E3SM Atmosphere Model Version 1 (EAMv1) and applications for high-resolution modelling
Authors: Tang Qi , Klein Stephen A. , Xie Shaocheng , Lin Wuyin , Golaz Jean-Christophe , Roesler Erika L. , Taylor Mark A. , Rasch Philip J. , Bader David C. , Berg Larry K. , Caldwell Peter , Giangrande Scott , Neale Richard , Qian Yun , Riihimaki Laura D. , Zender Charles S. , Zhang Yuying , Zheng Xue
Published: February 2019

Abstract. Climate simulation with more accurate process-level representation at finer resolutions is a pressing need in order to provide actionable information to policy-makers regarding extreme events in a changing climate. Computational limitation is a major obstacle for building, and running high-resolution (HR, here 0.25° average grid spacing at the equator) models (HRM). A more affordable path to HRM is to use a global regionally refined model (RRM), which only simulates a portion of the globe at HR while the remaining is at low-resolution (LR, 1°). In this study, we compare the Energy Exascale Earth System Model (E3SM) atmosphere model version 1 (EAMv1) RRM with the HR mesh over the contiguous United States (CONUS) to its corresponding globally uniform LR and HR configurations, as well as to observations and reanalysis data. The RRM has a significantly reduced computational cost (roughly proportional to the HR mesh size) relative to the globally uniform HRM. Over the CONUS, we evaluate the simulation of important dynamical and physical quantities as well as various precipitation measures. Differences between the RRM and HRM over the HR region are predominantly small, demonstrating that the RRM reproduces both well- and poorly simulated behaviours of the HRM over the CONUS. Further analysis based on RRM simulations with the LR vs. HR model parameters reveals that RRM performance is greatly influenced by the different parameter choices used in the LR and HR EAMv1. This is a result of the poor scale-aware behaviour of physical parameterizations, especially for variables influencing sub-grid scale physical processes. RRM can serve as a useful framework to test physics schemes across a range of scales, leading to improved consistency in future E3SM versions. Applying nudging-to-observations techniques within the RRM framework also demonstrates significant advantages over a free-running configuration for use as a testbed, and as such represents an efficient and more robust physics testbed capability. Our results provide additional confirmatory evidence that the RRM is an efficient and effective approach for HRM development and hydrologic research.
System-level design studies for large rotors
Authors: Zalkind Daniel S. , Ananda Gavin K. , Chetan Mayank , Martin Dana P. , Bay Christopher J. , Johnson Kathryn E. , Loth Eric , Griffith D. Todd , Selig Michael S. , Pao Lucy Y.
Published: February 2019

Abstract. We examine the effect of rotor design choices on the power capture and structural loading of each major wind turbine component. A steady-state, harmonic model derived from simulations using the NREL aeroelastic code FAST is developed to reduce computational expense while evaluating design trade-offs for rotors with radii greater than 100 m. Design studies are performed, which focus on blade aerodynamic and structural parameters as well as different hub configurations and nacelle placements atop the tower. The effects of tower design and closed-loop control are also analyzed. Design loads are calculated according to the IEC design standards and used to calibrate the harmonic model and quantify uncertainty. Our design studies highlight both industry trends and innovative designs: we progress from a conventional, upwind, 3-bladed rotor, to a rotor with longer, more slender blades that is downwind and 2-bladed. For a 13 MW design, we show that increasing the blade length by 25 m while decreasing the induction factor of the rotor increases annual energy capture by 11 % while constraining peak blade loads. A downwind, 2-bladed rotor design is analyzed, with a focus on its ability to reduce peak blade loads by 10 % per 5 deg. of cone angle, and also reduce total blade mass. However, when compared to conventional, 3-bladed, upwind designs, the peak main bearing load of the up-scaled, downwind, 2-bladed rotor is increased by 280 %. Optimized teeter configurations and individual pitch control can reduce non-rotating damage equivalent loads by 45 % and 22 %, respectively, compared with fixed-hub designs.
Aggregate poll Web site use across the 2016 United States presidential election
Authors: Hopp Toby , Sheehan Kim
Published: February 2019

This study examined citizens’ use of poll aggregation Web sites over the last nine weeks of the 2016 United States presidential campaign. The results suggested that usage frequency increases as election day approaches. Moreover, those with high levels of political interest and those that actively use media to obtain political information are most likely to access poll aggregation Web sites.
Sharing economy as an anti-concept
Authors: Pedroni Marco
Published: February 2019

The “sharing economy”, a term often used interchangeably with the “collaborative economy” and “collaborative consumption”, is a recurrent topic both in public and academic debate on new Web-based services characterized by forms of peer-to-peer or business-to-peer sharing. This paper investigates it theoretically as an “anti-concept”, that is, an unnecessary and rationally unusable label forged to replace a concept endowed with greater legitimacy. A critique of the sharing economy as a common-sense construct is carried out in order to suggest its rejection as an analytical and interpretative category and to question any unconditioned cultural legitimacy of the sharing economy under its promoters’ economic interests. Four main critical issues are discussed: (a) the contradiction between the relational and the commercial dimension; (b) regulatory challenges related to the dimensions of labour, trust, risk and agency; (c) the injunction to share; and (d) the consequences of the sharing economy in terms of social change. The notion of neoliberal entanglement economy is proposed to replace that of sharing economy.
On the ethical and political agency of online reputation systems
Authors: Wilson Anna , De Paoli Stefano
Published: February 2019

Social and socioeconomic interactions and transactions often require trust. In digital spaces, the main approach to facilitating trust has effectively been to try to reduce or even remove the need for it through the implementation of reputation systems. These generate metrics based on digital data such as ratings and reviews submitted by users, interaction histories, and so on, that are intended to label individuals as more or less reliable or trustworthy in a particular interaction context. We undertake a disclosive archaeology (Introna, 2014) of typical reputation systems, identifying relevant figuration agencies including affordances and prohibitions, (cyborg) identities, (cyborg) practices and discourses, in order to examine their ethico-political agency. We suggest that conventional approaches to the design of such systems are rooted in a capitalist, competitive paradigm, relying on methodological individualism, and that the reputation technologies themselves thus embody and enact this paradigm within whatever space they operate. We question whether the politics, ethics and philosophy that contribute to this paradigm align with those of some of the contexts in which reputation systems are now being used, and suggest that alternative approaches to the establishment of trust and reputation in digital spaces need to be considered for alternative contexts.