bluuebunny/crossref_metadata_2025 huggingface dataset:
Yapı Makinaları Kullanımında Karşılaşılan İş Kazalarının Azaltılmasına Yönelik Değerlendirmeler ve Öneriler
Authors: YAKAR Halil , TAÇGIN Ertuğrul
Published: May 2020

Sektörde işçi sağlığı ve iş güvenliği yönünden yapılan araştırmalar ve istatistikler dikkatli bir biçimde incelenecek olursa yapı makinaları kaynaklı kazaların ne denli ciddi sonuçlara yol açtığı daha rahat gözlenebilecektir. Yapı makinaları kaynaklı iş kazaları, sonuçları itibari ile sektördeki diğer iş kazaları ile karşılaştırıldığında ölümle ya da sürekli iş görmemezlikle sonuçlanan kazalar bakımından üst sıralarda yer almaktadır. Yapı makinalarının verimlilikte sağladığı avantajların yanı sıra işçi sağlığı ve iş güvenliği bakımından getirdiği risklere bağlı dezavantajları da değerlendirilmelidir. İnşaat sahalarında kullanılan bu makinaların doğurduğu, en ufak bir dikkatsizlikte ciddi sonuçları olan bu iş kazalarından en az hasarla kurtulabilmek için bir takım tedbirler almak zaruri olmuştur. En önemli tedbirler arasında şantiye trafik ve iş güvenliği planının hazırlanması, bu konuda sorumlulukların dağıtılması ve ayrıca operatörlere ve işçilere yönelik eğitimler ile makinaların bakım ve onarımlarının zamanında yapılması gelmektedir. Bu çalışmada öncelikli olarak Türkiye’deki iş kazalarında mevcut olan istatiksel veri bilgilendirmeleri üzerinde durulmuştur. Seçilen saha çalışması sonuçlarını da kullanarak iş makinalarını kullanan operatörlerin eğitimlerinin ve makine hakkındaki bilgi sahibi olmalarının ne kadar önemli olduğuna dikkat çekilmeye çalışılmıştır. Son olarak da operatör eğitimi konusunda Türkiye’deki eksikliğe vurgu yapılmıştır.
The effect of online exchanges via Skype on EFL learners’ achievements
Authors: Furumura Yumiko , Huang Hsin-Chou
Published: May 2020

This study examined whether direct communication with people from other countries using Skype or Line would affect students’ English test scores in listening and reading as well as the development of their curiosity concerning foreign cultures by comparing the data of an experimental group with that of a control group. The former group conducted online exchanges with foreign students, while the latter group did not. As many Japanese companies engaged in international business require high scores in the TOEIC test, which is one of the multiple-choice English tests of listening and reading often used to show each person’s English proficiency, universities in Japan are making efforts to improve their students’ scores in such an English test. Preparation classes for English tests have been offered. However, students have been likely to lose interest in learning English in the circumstances of this learning style. Results of the study indicated that although the aim of exchange activities is to foster students’ curiosity concerning intercultural matters, students experiencing online exchange with skype significantly raised their scores in TOEIC tests in listening and reading after a programme of synchronous exchanges with foreign students, compared with ones who did not experience such online exchanges.
A machine-learning-based cloud detection and thermodynamic-phase classification algorithm using passive spectral observations
Authors: Wang Chenxi , Platnick Steven , Meyer Kerry , Zhang Zhibo , Zhou Yaping
Published: May 2020

Abstract. We trained two Random Forest (RF) machine learning models for cloud mask and
cloud thermodynamic-phase detection using spectral observations from Visible Infrared
Imaging Radiometer Suite (VIIRS)
on board Suomi National Polar-orbiting Partnership (SNPP). Observations from Cloud-Aerosol Lidar
with Orthogonal Polarization (CALIOP) were carefully selected to
provide reference labels. The two RF models were trained for all-day and
daytime-only conditions using a 4-year collocated VIIRS and CALIOP dataset from
2013 to 2016. Due to the orbit difference, the collocated CALIOP and SNPP
VIIRS training samples cover a broad-viewing zenith angle range, which is a
great benefit to overall model performance. The all-day model uses three VIIRS
infrared (IR) bands (8.6, 11, and 12 µm), and the daytime model uses five
Near-IR (NIR) and Shortwave-IR (SWIR) bands (0.86, 1.24, 1.38, 1.64, and 2.25 µm) together with the three IR bands to detect clear, liquid water, and ice
cloud pixels. Up to seven surface types, i.e., ocean water, forest, cropland,
grassland, snow and ice, barren desert, and shrubland, were considered
separately to enhance performance for both models. Detection of cloudy
pixels and thermodynamic phase with the two RF models was compared against
collocated CALIOP products from 2017. It is shown that, when using a conservative
screening process that excludes the most challenging cloudy pixels for
passive remote sensing, the two RF models have high accuracy rates in
comparison to the CALIOP reference for both cloud detection and
thermodynamic phase. Other existing SNPP VIIRS and Aqua MODIS cloud mask and
phase products are also evaluated, with results showing that the two RF
models and the MODIS MYD06 optical property phase product are the top three
algorithms with respect to lidar observations during the daytime. During the
nighttime, the RF all-day model works best for both cloud detection and
phase, particularly for pixels over snow and ice surfaces. The present RF
models can be extended to other similar passive instruments if training
samples can be collected from CALIOP or other lidars. However, the quality
of reference labels and potential sampling issues that may impact model
performance would need further attention.
Toward a variational assimilation of polarimetric radar observations in a convective-scale numerical weather prediction (NWP) model
Authors: Thomas Guillaume , Mahfouf Jean-François , Montmerle Thibaut
Published: May 2020

Abstract. This paper presents the potential of nonlinear and linear versions of an observation operator for simulating polarimetric variables observed by weather radars. These variables, deduced from the horizontally and vertically polarized backscattered radiations, give information about the shape, the phase and the distributions of hydrometeors. Different studies in observation space are presented as a first step toward their inclusion in a variational data assimilation context, which is not treated here.
Input variables are prognostic variables forecasted by the AROME-France numerical weather prediction (NWP) model at convective scale, including liquid and solid hydrometeor contents. A nonlinear observation operator, based on the T-matrix method, allows us to simulate the horizontal and the vertical reflectivities (ZHH and ZVV), the differential reflectivity ZDR, the specific differential phase KDP and the co-polar correlation coefficient ρHV. To assess the uncertainty of such simulations, perturbations have been applied to input parameters of the operator, such as dielectric constant, shape and orientation of the scatterers. Statistics of innovations, defined by the difference between simulated and observed values, are then performed. After some specific filtering procedures, shapes close to a Gaussian distribution have been found for both reflectivities and for ZDR, contrary to KDP and ρHV. A linearized version of this observation operator has been obtained by its Jacobian matrix estimated with the finite difference method. This step allows us to study the sensitivity of polarimetric variables to hydrometeor content perturbations, in the model geometry as well as in the radar one. The polarimetric variables ZHH and ZDR appear to be good candidates for hydrometeor initialization, while KDP seems to be useful only for rain contents. Due to the weak sensitivity of ρHV, its use in data assimilation is expected to be very challenging.
Validation of the vertical profiles of HCl over the wide range of the stratosphere to the lower thermosphere measured by SMILES
Authors: Nara Seidai , Sato Tomohiro O. , Yamada Takayoshi , Fujinawa Tamaki , Kuribayashi Kota , Manabe Takeshi , Froidevaux Lucien , Livesey Nathaniel J. , Walker Kaley A. , Xu Jian , Schreier Franz , Orsolini Yvan J. , Limpasuvan Varavut , Kuno Nario , Kasai Yasuko
Published: May 2020

Abstract. Hydrogen chloride (HCl) is the most abundant (more than 95 %) among inorganic chlorine compounds Cly in the stratosphere. The HCl molecule has been observed to obtain long-term quantitative estimations of total budget of the stratospheric anthropogenic chlorine compounds. In this study, we provided HCl vertical profiles at altitudes of 16–100 km using the superconducting submillimeter-wave limb-emission sounder (SMILES) from space. We used the SMILES Level-2 research product version 3.0.0. The period of the SMILES HCl observation was from October 12, 2009 to April 21, 2010, and the latitude coverage was 40S–65N. The average HCl vertical profile showed an increase with altitude up to the stratopause (~ 45 km), approximately constant values between the stratopause and the upper mesosphere (~ 80 km), and a decrease from the mesopause to the lower thermosphere (~ 100 km). This behavior was observed in the all latitude regions, and reproduced by the SD-WACCM model. We compared the SMILES HCl vertical profiles in the stratosphere and lower mesosphere with HCl profiles from MLS on the Aura satellite, as well as from ACE-FTS on SCISAT and from TELIS (balloon-borne). The TELIS observations were performed using the superconductive limb emission technique, as used by SMILES. The globally averaged vertical HCl profiles of SMILES well agreed with those of MLS and ACE-FTS within 0.25 and 0.2 ppbv between 20 and 40 km, respectively. The SMILES HCl concentration was smaller than those of MLS and ACE/FTS as the altitude increased from 40 km, and the difference was approximately 0.4–0.5 ppbv at 50–60 km. The difference between SMILES and TELIS HCl observations was about 0.3 ppbv in the polar winter region between 20 and 34 km, except near 26 km. SMILES HCl error sources that may cause discrepancies with the other observations are investigated by a theoretical error analysis. We calculated errors caused by the uncertainties of spectroscopic parameters, instrument functions, and atmospheric temperature profiles. The jacobian for the temperature explains the negative bias of the SMILES HCl concentration at 50–60 km. The HCl vertical profile from the middle troposphere to the lower thermosphere is reported for the first time from SMILES observations; the data quality is quantified by comparisons with other measurements and via theoretical error analysis.
A Comparison of Contact Charging and Impact Ionization in Low Velocity Impacts: Implications for Dust Detection in Space
Authors: Antonsen Tarjei , Mann Ingrid , Vaverka Jakub , Nouzak Libor , Fredriksen Åshild
Published: May 2020

Abstract. We investigate the generation of charge during collision of projectiles with sizes below ~ 1 μm and metal surfaces at speeds ~ 0.1 km/s. This corresponds to speeds above the elastic limit and well below speeds where volume ionization can occur. The conditions that we consider apply to dust particles naturally occurring in space and in Earth's upper atmosphere and their direct impacts on rockets, spacecraft, and impacts of secondary ejecta. We introduce a model of capacitive contact charging in which we allow for projectile fragmentation upon impact, and show that this model describes measurements of metal-metal impacts in the laboratory and in-situ measurements of dust in the Earth's atmosphere well. We have considered the utilization of our model for different scenarios in interplanetary space and in Earth's atmosphere. From this discussion we find it likely that our work can be employed in a number of situations where impact velocities are relatively small. Furthermore, we have discussed the thermodynamics of the low velocity solution of shock wave ionization, and conclude that the impurity charging effect utilized in the much used model of Drapatz and Michel (1974) does not sufficiently describe charge generation at impact speeds below a few kilometers per second. Consequently, impact charging at low speeds cannot be described with a Saha-solution.
Resolution dependence of magnetosheath waves in global hybrid-Vlasov simulations
Authors: Dubart Maxime , Ganse Urs , Osmane Adnane , Johlander Andreas , Battarbee Markus , Grandin Maxime , Pfau-Kempf Yann , Turc Lucile , Palmroth Minna
Published: May 2020

Abstract. Plasma waves are ubiquitous in the Earth's magnetosheath. The most commonly observed waves arise from instabilities generated by temperature anisotropy of the ions, such as the mirror and proton cyclotron instabilities. We investigate here the spatial resolution dependence of the mirror and proton cyclotron instabilities in a global hybrid-Vlasov simulation using the Vlasiator model. We compare the proton velocity distribution functions, power spectra and growth rates of the instabilities in a set of simulations with three different spatial resolutions but otherwise identical set-up. We find that the proton cyclotron instability is absent at the lowest resolution and that only the mirror instability remains, which leads to an increased temperature anisotropy in the simulation. We conclude that the proton cyclotron instability is resolved well enough at the highest spatial resolution and that an increase of resolution does not improve the resolution of the instability enough to justify this increase at the cost of numerical resources in future simulations. We also find that a resolution around 0.6 the inertial length in the solar wind, presents an acceptable minimum spatial resolution in which the proton cyclotron is still correctly resolved. These results should be taken into consideration regarding the optimal grid spacing for the modelling of magnetosheath waves, within available computational resources.
Technical note: Low meteorological influence found in 2019 Amazonia fires
Authors: Kelley Douglas I. , Burton Chantelle , Huntingford Chris , Brown Megan A. J. , Whitley Rhys , Dong Ning
Published: May 2020

Abstract. The sudden increase in Amazon fires early in the 2019 fire season made global headlines. While it has been heavily speculated that the fires were caused by deliberate human ignitions or human-induced landscape changes, there have also been suggestions that meteorological conditions could have played a role. Here, we ask two questions: were the 2019 fires in the Amazon unprecedented in the historical record?; and did the meteorological conditions contribute to the increased burning? To answer this, we take advantage of a recently developed modelling framework which optimizes a simple burnt area model, and whose outputs are described as probability densities. This allowed us to test the probability of the 2019 fire season occurring due to meteorological conditions alone. We show that the burnt area was indeed higher than previous years in regions where there is already substantial deforestation activity in the Amazon, with 11 % of the area recording the highest early season (June–August) burnt area since the start of our observational record. However, areas outside of the regions of widespread deforestation show less burnt area than the historical average, and the optimized model shows that there is a 71 % probability that this low burned area would have been expected over the entire Amazon region, including regions already witnessing deforestation and of high fire occurrence in 2019. We show that there is a
Testing Hypotheses About Glacial Dynamics and the Stage 11 Paradox Using a Statistical Model of Paleo-Climate
Authors: Kaufmann Robert K. , Pretis Felix
Published: May 2020

Abstract. To test hypotheses about glacial dynamics, the Mid-Brunhes event, and the stage 11 paradox, we evaluate the ability of a statistical model to simulate climate during the previous ~800 000 years. Throughout this period, the model simulates the timing and magnitude of glacial cycles, including the saw-tooth pattern in which ice accumulates gradually and ablates rapidly, without nonlinearities or threshold effects. This suggests that nonlinearities and/or threshold effects do not play a critical role in glacial cycles. Furthermore, model accuracy throughout the previous ~800 000 years suggest that changes in glacial cycles associated with the Mid-Brunhes event, which occurs near the division between the out-of-sample period and the in-sample period, are not caused by changes in the dynamics of the climate system. Conversely, poor model performance during MIS stage 11 and Termination V is consistent with arguments that the stage 11 paradox represents a mismatch between orbital geometry and climate. Statistical orderings of simulation errors indicate that periods of reduced accuracy start with significant reductions in the model's ability to simulate carbon dioxide, non-sea-salt sodium, and non-sea-salt calcium. Their importance suggests that the stage 11 paradox is generated by changes in atmospheric and/or oceanic circulation that affect ocean ventilation of carbon dioxide.
Integrating palaeoclimate time series with rich metadata for uncertainty modelling: strategy and documentation of the PalMod 130k marine palaeoclimate data synthesis
Authors: Jonkers Lukas , Cartapanis Olivier , Langner Michael , McKay Nick , Mulitza Stefan , Strack Anne , Kucera Michal
Published: May 2020

Abstract. Palaeoclimate data hold the unique promise of providing a long-term
perspective on climate change and as such can serve as an important
benchmark for climate models. However, palaeoclimate data have generally
been archived with insufficient standardisation and metadata to allow for
transparent and consistent uncertainty assessment in an automated way.
Thanks to improved computation capacity, transient palaeoclimate simulations
are now possible, calling for data products containing multi-parameter time
series rather than information on a single parameter for a single time
slice. Efforts are underway to simulate a complete glacial–interglacial
cycle using general circulation models (https://www.palmod.de/, last access: 6 May 2020), and to confront these
simulations with palaeoclimate data, we have compiled a multi-parameter
marine palaeoclimate data synthesis that contains time series spanning 0 to
130 000 years ago. We present the first version of the data product that
focuses exclusively on time series for which a robust chronology based on
benthic foraminifera δ18O and radiocarbon dating is available.
The product contains 896 time series of eight palaeoclimate parameters from
143 individual sites, each associated with rich metadata, age–depth model
ensembles, and information to refine and update the chronologies. This
version contains 205 time series of benthic foraminifera δ18O;
169 of benthic foraminifera δ13C; 131 of seawater temperature;
174 and 119 of planktonic foraminifera δ18O and δ13C; and 44, 38 and 16 of carbonate, organic carbon and biogenic silica
content, respectively. The data product is available in three formats (R,
LiPD and netCDF) facilitating use across different software and operating
systems and can be downloaded at https://doi.org/10.1594/PANGAEA.908831 (Jonkers et al., 2019). This
data descriptor presents our data synthesis strategy and describes the
contents and format of the data product in detail. It ends with a set of
recommendations for data archiving.
Key Landscapes for Conservation Land Cover and Change
Monitoring Thematic and Validation Datasets for Sub-Saharan
Africa
Authors: Szantoi Zoltan , Brink Andreas , Lupi Andrea , Mannone Claudio , Jaffrain Gabriel
Published: May 2020

Abstract. Threats to biodiversity pose an enormous challenge for Africa. Mounting social and economic demands on natural resources increasingly threaten key areas for conservation. Effective protection of sites of strategic conservation importance requires timely and highly detailed geospatial monitoring. Larger ecological zones and wildlife corridors warrant monitoring as well, as these areas have an even higher degree of pressure and habitat loss. To address this, a satellite imagery based monitoring workflow to cover at-risk areas at various details was developed. During the program's first phase, a total of 560,442 km2 area in Sub-Saharan Africa was covered, from which 153,665 km2 were mapped with 8 land cover classes while 406,776 km2 were mapped with up to 32 classes. Satellite imagery was used to generate dense time series data from which thematic land cover maps were derived. Each map and change map were fully verified and validated by an independent team to achieve our strict data quality requirements. The independent validation datasets for each KLCs are also described and presented here (The complete dataset available at Szantoi et al., 2020B https://doi.org/10.1594/PANGAEA.914261, and a demonstration dataset at Szantoi et al., 2020C https://doi.pangaea.de/10.1594/PANGAEA.915849).
The challenges of an in situ validation of a non-equilibrium model of soil heat and moisture dynamics during fires
Authors: Massman William J.
Published: May 2020

Abstract. With the increasing frequency and severity of fire there is an increasing desire to better manage fuels and minimize, as much as possible, the impacts of fire on soils and other natural resources. Piling and/or burning slash is one method of managing fuels and reducing the risk and consequences of wildfire, but the repercussions to the soil, although very localized, can be significant and often irreversible. In an effort to provide a tool to better understand the impact of fire on soils, this study outlines the improvements to and the in-situ validation of a non-equilibrium model for simulating the coupled interactions and transport of heat, moisture and water vapor during fires. Improvements to the model eliminate two important (but heretofore universally overlooked) inconsistencies: one that describes the relationship between evaporation and condensation in the parameterization of the non-equilibrium vapor source term and the other, is the incorrect use of the apparent thermal conductivity in the soil heat flow equation. The first of these enhanced the stability and performance of the model. The second is an important improvement in the model's physical realism, but had less of an impact on the model's performance and stability than the first. The model validation uses (in-situ temperature, soil moisture, and heat flux) data obtained in a 2004 experimental slash pile burn. Important temperature dependent corrections to the instruments used for measuring soil heat flux and moisture are also discussed and assessed. Despite any possible ambiguities in the calibration the sensors or the simplicity of the parameterization of the surface heating function, the difficulties and complexities of formulating the upper boundary condition, and the obvious complexities of the dynamic response of the soil's temperature and heat flux, the model produced at least a very credible, if not surprisingly good, simulation of the observed data. This study then continues with a discussion and sensitivity analysis of some important feedbacks (some of which are well known and others that are more hypothetical) that are not included in the present (or any extant) model, but undoubtedly are dynamically influencing the physical properties of the soil in-situ during the fire and thereby modulating the behavior of the soil temperature and moisture. This manuscript concludes with a list of possible future observational and modeling studies and how they would advance the research and findings discussed here.
Hydrology and Water Resources Management in Ancient India
Authors: Singh Pushpendra Kumar , Dey Pankaj , Jain Sharad Kumar , Mujumdar Pradeep
Published: May 2020

Abstract. Hydrologic knowledge in India has a historical footprint extending over several millenniums through the Harappan Civilisation (~ 3000 BC–1500 BC) and the Vedic period (~ 1500–500 BC). As in other ancient civilisations across the world, the need to manage water propelled the growth of hydrologic science in ancient India also. Most of the ancient hydrologic knowledge, however, has remained hidden and unexplored to the world at large till the recent times. In this paper, we provide some fascinating glimpses into the hydrological, hydraulic and related engineering knowledge that existed in ancient India, as discussed in contemporary literature and in the recent explorations and findings. The Vedas, particularly, the Rigveda, Yajurveda and Atharvaveda have many references to water cycle and associated processes, including water quality, hydraulic machines and other structures and nature-based solutions (NBS) for water management. The Harappan Civilization epitomizes the level of development of water sciences in ancient India that includes construction of sophisticated hydraulic structures, wastewater disposal systems based on centralized and decentralized concepts as well as methods for wastewater treatments. The Mauryan empire (~ 322 BC–185 BC) is credited as the first hydraulic civilization characterised by construction of dams with spillways, reservoirs, channels equipped with spillways, pynes and Ahars, understanding of water balance, development of water pricing systems, measurement of rainfall and knowledge of the various hydrological processes. As we investigate deeper into hydrologic references in ancient literature, including the Indian mythology, many fascinating dimensions of the early scientific endeavours of Indians emerge.
Modeling inorganic carbon dynamics in the Seine River continuum in France
Authors: Marescaux Audrey , Thieu Vincent , Gypens Nathalie , Silvestre Marie , Garnier Josette
Published: May 2020

Abstract. Inland waters are an active component of the carbon cycle where
transformations and transports are associated with carbon dioxide (CO2) outgassing. This study estimated CO2 emissions from the human-impacted Seine River (France) and provided a detailed budget of aquatic carbon transfers for organic and inorganic forms, including the in-stream metabolism along the whole Seine River network. The existing process-based biogeochemical pyNuts-Riverstrahler model was supplemented with a newly developed inorganic carbon module and simulations were performed for the recent time period 2010–2013. New input constraints for the modeling of riverine inorganic carbon were documented by field measurements and complemented by analysis of existing databases. The resulting dissolved inorganic carbon (DIC) concentrations in the Seine aquifers ranged from 25 to 92 mg C L−1, while in wastewater treatment plant (WWTP) effluents our DIC measurements averaged 70 mg C L−1. Along the main stem of the Seine River, simulations of DIC, total alkalinity, pH and CO2 concentrations were of the same order of
magnitude as the observations, but seasonal variability was not always well
reproduced. Our simulations demonstrated the CO2 supersaturation with respect to atmospheric concentrations over the entire Seine River network. The most significant outgassing was in lower-order streams while peaks were simulated downstream of the major WWTP effluent. For the period studied (2010–2013), the annual average of simulated CO2 emissions from the Seine drainage network were estimated at 364±99 Gg C yr−1. Results from metabolism analysis in the Seine hydrographic network
highlighted the importance of benthic activities in headwaters while
planktonic activities occurred mainly downstream in larger rivers. The net
ecosystem productivity remained negative throughout the 4 simulated years
and over the entire drainage network, highlighting the heterotrophy of the
basin. Highlights
CO2 emission from the Seine River was estimated at 364±99 Gg C yr−1 with the Riverstrahler model. CO2 riverine concentrations are modulated by groundwater discharge and instream metabolism. CO2 emissions account for 31 % of inorganic carbon exports, the rest being exported as DIC.
Extreme wave analysis based on atmospheric pattern classification: an application along the Italian coast
Authors: De Leo Francesco , Solari Sebastián , Besio Giovanni
Published: May 2020

Abstract. This paper provides a methodology for classifying samples of significant wave-height peaks in homogeneous subsets in terms of the atmospheric circulation patterns behind the observed extreme wave conditions. Then, a methodology is given for the computation of the overall extreme value distribution by starting from the distributions fitted to each single subset. To this end, the k-means clustering technique is used to classify the shape of the wind fields that occurred simultaneously to and prior to the occurrences of the extreme wave events. This results in a small number of characteristic circulation patterns related to as many subsets of extreme wave values. After fitting an extreme value distribution to each subset, bootstrapping is used to reconstruct the omni-circulation pattern's extreme value distribution. The methodology is applied to several locations along the Italian buoy network, and it is concluded from the obtained results that it yields a two-fold advantage: first, it is capable of identifying clearly differentiated subsets driven by homogeneous circulation patterns; second, it allows one to estimate high-return-period quantiles consistent with those resulting from the usual extreme value analysis. In particular, the circulation patterns highlighted are analyzed in the context of the Mediterranean Sea's atmospheric climatology and are shown to be due to well-known cyclonic systems typically crossing the Mediterranean basin.
Forecasting dam height and stability of dams formed by rock slope failures in Norway
Authors: Oppikofer Thierry , Hermanns Reginald L. , Jakobsen Vegard U. , Böhme Martina , Nicolet Pierrick , Penna Ivanna
Published: May 2020

Abstract. Based on an inventory of 69 dams formed by rock slope failures in southwestern Norway and published landslide dam inventories from other parts of the World we developed semi-empirical relationships linking the maximum dam height (HD.max in m) to dam volume (VD in 106 m3) and other relevant parameters such as valley width (WV in m) or dam area (AD in km2). Power-laws are obtained for HD.max = f(VD) and HD.max = f(VD, WV), while a linear relationship links HD.max to the ratio VD / AD. For dams in southwestern Norway, the linear relationship HD.max = 1.75 × VD / AD has least uncertainties and provides best results when comparing predicted dam heights with a validation dataset composed of existing dams in northern Norway and numerically modelled dams for possible rock slope failures. To assess the stability of future dams we use the predicted dam heights in the dimensionless blockage index DBI and relating this index to the probability of dam failure derived from our dataset and other published databases on landslide dams. This study underlines the potential of semi-empirical relationships for assessing dam height and stability that needs to be included in preliminary hazard and risk assessment for unstable rock slopes, because damming of a river is an important secondary effect of landslides due to upstream flooding and possible outburst floods in case of dam failure.
Assessment of responses of North Atlantic winter SST to the NAO in 13 CMIP5 models on the interannual scale
Authors: Jing Yujie , Li Yangchun , Xu Yongfu
Published: May 2020

Abstract. This study evaluates the response of winter-averaged sea surface temperature (SST) to the winter North Atlantic Oscillation (NAO) simulated by 13 CMIP5 Earth System Models in the North Atlantic (NA) (0–65° N) on the interannual scale. Only 7 models can reproduce an observed tripolar pattern of the response of SST anomalies to the NAO, and most of the models cannot generate the observed impact of variations of the turbulent heat flux on the response of SST anomalies to the NAO. In the subpolar NA (45–65° N) where the influences of sensible/latent heat fluxes on SST are obvious, most of the models simulate a positive response of SST to the turbulent heat flux in the large area of this region, which is opposite to the observations, and probably generate the incorrect positive response of SST to the NAO in some models. In the subtropical NA (25–45° N), the observations show a significant influence of latent heat flux (LHF) on SST, but the overestimated oceanic role in the interaction of the LHF and SST in most CMIP5 models results in an incorrect positive response of SST anomalies to the LHF anomalies in a large area of the subtropical NA. Besides the turbulent heat flux, the meridional advection is also important to the change of the SST in the NA. The analysis of the simulated and observed results shows that NAO-driven meridional advection can cause the increase/decrease of SST during the positive phase of the NAO in the subtropical/subpolar NA. This is probably one of the main causes why the models can simulate the realistic positive response of SST anomalies to the NAO in the subtropical NA, but the strength of the positive response is relatively weak.
In situ hydromechanical responses during well drilling recorded by distributed fiber-optic strain sensing
Authors: Zhang Yi , Lei Xinglin , Hashimoto Tsutomu , Xue Ziqiu
Published: May 2020

Abstract. Drilling fluid infiltration during well drilling induces pore pressure and strain perturbations in neighboured reservoir formations. In this study, we in situ monitored such small strain changes (~ 20 µε) using fiber-optic distributed strain sensing in two observation wells with different distances (approximately 3 m and 9 m) from a new drilling wellbore in a shallow water aquifer. The results suggest that the drilling induced hydromechanical deformations that occurred at depths of both wells are indicative of the impact zones of fluid invasion and reservoir permeability structure (heterogeneity). A hydraulic diffusion model is used to interpret the strain evolution. The method and data would be useful for understanding reservoir pressure communications, determining the zones for fluid productions or injections (e.g., for CO2 storage), and optimizing reservoir management and utilization.
A surrogate model approach for associating wind farm load variations with turbine failures
Authors: Schröder Laura , Dimitrov Nikolay Krasimirov , Verelst David Robert
Published: May 2020

Abstract. In order to ensure structural reliability, wind turbine design is typically based on the assumption of gradual degradation of material properties (fatigue loading). However, the relation between the wake-induced load exposure of turbines and the reliability of their major components has not been sufficiently well defined and demonstrated. This study suggests a methodology that makes it possible to correlate loads with reliability of turbines in wind farms in a computationally efficient way by combining physical modeling with machine learning. It can be used for estimating the current health state of a turbine and enables a more precise prediction of the load budget, i.e. the effect of load-induced degradation and faults on the operating costs of wind farms. The suggested approach is demonstrated on an offshore wind farm for comparing performance, loads and lifetime estimations against recorded main bearing failures from maintenance reports. The validation of the estimated power against the 10-min SCADA power signals shows that the surrogate model is able to capture the power performance relatively well with a 1.5 % average error in the prediction of the Annual Energy Production (AEP). It is found that turbines positioned at the border of the wind farm with a higher expected AEP are estimated to experience earlier main bearing failures.
Diplomacy and Trade: The Current Contradictory Relations between the United States and Bolivia
Authors: Langer Erick D.
Published: May 2020

Diplomatic relations between Bolivia and the United States have been difficult since Evo Morales became president in 2006. Despite these poor relations and even despite the abrogation of the ATPDEA (Andean Trade Promotion and Drug Eradication Act) in 2008, commerce between Bolivia and the United States has increased more than during governments allied with the United States. These conclusions show that the state of diplomatic relations are not necessarily indicative of the intensity of trade between countries.
Moving from collaboration to critical dialogue in action in education
Authors: Matusov Eugene , Pease-Alvarez Lucinda
Published: May 2020

The purpose of this article is to examine and conceptualize our pedagogical and organizational experiences and understandings of how undergraduates and instructors participating in the UC-Links Project from Fall 1996 to Spring 1997 learned together through their engagements in undergraduate courses and afterschool activities with predominantly Mexican-descent children at a local community center. We had started our project privileging collaboration and collaborative guidance as the way to approach our collective engagements; however, the events in the project pushed us to reconsider our practice. It took us 25 years to completely understand that what we have come to call “critical dialoguing in action” is how we now conceive of innovative organizational and pedagogical practice, which stands in contrast to the pedagogical and organizational notion of collaboration. We describe the efforts and struggles participants, including ourselves, encountered developing, implementing, and communicating about innovative teaching approaches and practices that we originally thought aimed to promote meaningful and collaborative learning. We call particular attention to dilemmas participants faced dialoguing about the dynamic teaching/learning processes that emerged in our project. These experiences prompted us to characterize our vision for participants’ involvement in the project as “critical dialoguing in action,” which contributed to our ongoing analysis and understanding of emerging dilemmas in our work.
COVID-19: ¿(in)seguridad sin (in)movilidad? Acercando la política de la movilidad a los Estudios Críticos de Seguridad
Authors: Iranzo Ángela
Published: May 2020

El artículo reflexiona sobre tres ideas: la pandemia de COVID-19, la seguridad y la movilidad. Si bien la potencial amenaza del coronavirus depende del movimiento (propagación, transmisión, infección), el movimiento y la movilidad son un “punto ciego” en los Estudios Críticos de Seguridad. El artículo propone analizar el nexo pandemia-seguridad a través de la lente de la política de la movilidad y explorar las ventajas analíticas de acercar el Paradigma de las Nuevas Movilidades a los Estudios Críticos de Seguridad. Argumenta que esta lente puede ayudar a explicar cómo intersectan y coproducen mutuamente las (in)movilidades e (in)seguridades asociadas a la pandemia. Además, al abordar el nexo pandemia-seguridad como parte de la política de la movilidad, emergen desafíos relevantes para los enfoques críticos de seguridad como explicar la dimensión discursiva en relación a otras como el movimiento y la experiencia; la acción de agencias humanas y no humanas; y las diferentes localizaciones del poder en sentido “multi-lugar”.
Teacher Professional Development in Language-Driven CLIL: A Case Study
Authors: Banegas Dario Luis
Published: May 2020

The professional development of and language integrated learning (CLIL) continues to be a niche in the language education literature, particularly in Latin America. The aim of this study is to explore the effects of a continuing professional development course delivered in 2018 to support language-driven CLIL implementation in state secondary schools in Argentina. Built as a case study, the investigation draws on data from one teacher collected through multiple sources for triangulation purposes. Two research questions guided the study: 1) What beliefs does a teacher have of language-driven CLIL? and 2) What are the effects of a continuing professional development course on language-driven CLIL targeted at EFL secondary school teachers? Findings show that authenticity, rather than language-content integration, is a salient feature of language-driven CLIL in this teacher’s practice. Findings also reveal that CLIL success depends on learners’ English language proficiency. Drawing on its teacher’s beliefs of CLIL, the course had an impact on the teacher’s identity as a materials developer and autonomous and critical practitioner who could theorize by reflecting on her practices and the readings provided by the course tutor.
Establishing Teacher-Student Rapport in an English-Medium Instruction Class
Authors: Santana Josefina del Carmen
Published: May 2020

English-medium instruction classes in higher education are increasing in countries where English is not the first language. Though these courses offer advantages, they also offer concerns and challenges. One of these challenges is creating a rapport between a teacher and students who are working in a language that is not their own. Rapport is important because it has been linked to academic performance. This study explored possible differences in rapport between two groups of students who were taking a class on Communications Research at a Mexican university. One group took the class in their native language, Spanish, and the other one took the class in English. The teacher, the programme, and the materials were identical in both cases; they only differed in the language of instruction. The study is qualitative in the ethnographic tradition. Videos of classroom interactions were used as a data source, which were analysed and coded. Codes were based on rapport-building activities. The teacher’s log and the nine-item Student-Instructor Rapport scale complemented the study. The videos showed evidence of rapport-building activities in both the Spanish and English groups. The results of the scale showed that the students in the English group perceived a stronger rapport between the instructor and the students, than those in the Spanish group.
Resonance Frequency Assessment: The Challenge of Standardizing Heart Rate Variability Biofeedback Research
Authors: Shaffer Fredric
Published: May 2020

The resonance frequency (RF) is the rate at which a system, like the cardiovascular system, can be activated or stimulated for maximal variability. Precise RF measurement is needed to standardize training protocols to help researchers determine the importance of RF breathing in achieving clinical and optimal performance outcomes. Lehrer and colleagues have developed and standardized a psychometrically reliable RF measurement protocol that can facilitate training and replication. This article provides a detailed description of their protocol and explains the nuanced decision-making process involved in identifying the RF. The validity and reproducibility of results using this protocol depend on quality control in (a) confirming that individuals successfully follow a breathing pacer, and (b) manually removing artifacts from data records. While this protocol requires an electrocardiogram or photoplethysmograph sensor and a respirometer, professionals should consider the addition of autonomic, musculoskeletal, and respiratory measures to better understand the patterns of physiological activity produced by different breathing rates.
Factors and survival of exclusive breastfeeding in preterm infants upon discharge at six months of age
Authors: Gallegos-Martínez Josefina , Reyes-Hernández Jaime , Torres-Carreón Fátima de San Carlos , Cuéllar-Miranda Blanca Esther , Leite Adriana , Scochi Carmen Gracinda
Published: May 2020

Introduction and objective: Reducing the neonatal mortality rate in half is an objective proposed by WHO for the year 2025 through coverage strategies from the prenatal stage, delivery, birth, and hospitalization, one of these low-cost strategies is exclusive breastfeeding (EBF) in preterm infants, that contributes to the prevention of neonatal mortality, a population that contributes in the first place to neonatal mortality. The objective of this study was to identify the frequency and survival of exclusive breastfeeding and related factors in premature infants of two referral hospitals, one of them certified as Baby-Friendly Hospital Initiative (BFHI).Methods: Follow-up study of 111 premature infants after hospital discharge with equivalent corrected age among hospitals: BFHI 36.1 ± 1.6; non-BFHI (nBFHI) 36.4 ± 1.8 weeks (p ≥ .05). Data collection carried out from February 2016 to March 2017, through records in clinical files and surveys of mothers upon hospital discharge and by telephone during follow-up after 15 days post-discharge, 3, and 6 months of extrauterine life. Kaplan-Meier analysis to determine breastfeeding survival over time, and with Pearson’s r with significance p ≤ .05, the relation was established between EBF with sociodemographic, perinatal, and clinical status factors of the child.Results: Urban maternal origin (68.1%), maternal age (25.7 ± 7.9 years), schooling < 12 years (56.6%). EBF upon discharge on 45/111 dyads (40.5%), 15 days post-discharge 35/73 (47.9%), third month 23/61 (37.7%) and sixth month 7/44 (15.9%). EBF survival was 15 days post-discharge, at this cut-off point, among the correlated factors are: “having received guidance to use Exclusive Breastfeeding until the sixth month of extrauterine life of the premature child” positively correlated with EBF (r = 0.294, p ≤ .05), “the maternal perception that her milk dried” correlated negatively with EBF (r = -0.313, p ≤ .01), if “breastfeeding caused anxiety to the mother” it positively correlated with artificial feeding (AF) (r = 0.237, p ≤ .05).Conclusions: Exclusive breastfeeding in premature infants is below WHO standard, it is favorably related to maternal orientation, and barriers are maternal perceptions of non-milk supply and anxiety. It could be encouraged through actions carried out in hospitals certified with the Baby-Friendly Hospital Initiative and follow up with post-discharge breastfeeding at least to the sixth month of life of premature infants. Similar studies should establish better monitoring mechanisms to avoid losses during the follow-up.
Apresentação do dossiê – coetaneidade, pós-colonialidade, diáspora(s) e africanidade(s): caminhos dos estudos africanos no Brasil
Authors: Muller Paulo Ricardo , Araújo Melvina Afra Mendes de
Published: May 2020

Os conceitos de coetaneidade e pós-colonialidade referem-se a movimentos de ampliação das perspectivas a partir das quais as Ciências Sociais abordam o continente africano contemporaneamente, suscitando críticas ao caráter eurocêntrico de seu referencial mais clássico. Experiências de pesquisa em contextos africanos, sobretudo em Países Africanos de Língua Oficial Portuguesa (PALOP), são um componente significativo do processo de internacionalização da pesquisa e da pós-graduação em Ciências Sociais e produz aportes fundamentais para a consolidação da Educação das Relações Étnico-Raciais (ERER) nas instituições de ensino brasileiras, afirmando-se, assim, a relevância da temática proposta. Este dossiê reúne artigos dedicados à compreensão da contemporaneidade do continente africano tanto por meio de análises de processos históricos à luz de novos conceitos e abordagens das Ciências Sociais quanto da rediscussão de determinados pressupostos teórico-metodológicos à luz de novas questões, problemas, conflitos e práticas sociais. Para apresentá-lo, este artigo percorre a construção e as principais críticas aos dois conceitos que o estruturam: coetaneidade e pós-colonialidade. Ao final, buscamos mostrar como as limitações e potencialidades desses conceitos se tornam mais evidentes em diálogo com os conceitos de africanidade e de diáspora.