bluuebunny/crossref_metadata_2025 huggingface dataset:
Viscosity-Temperature Characteristics and Application of High Borosilicate Glass
Authors: Wang Yan Hang , Han Tao , He Kun , Zu Cheng Kui
Published: April 2020

Viscosity-temperature characteristics of high borosilicate glass were investigated in detail by means of rotor viscometer and dilatometer. The neck-down deformation process of glass tube was simulated by Polyflow software, and the simulation was verified by the secondary drawing of glass perform. The results showed that the high temperature viscosity of borosilicate glass is higher compared to that of ordinary optical glass. In the high temperature stage, the fitting curves of VFT, AV, AG and MYEGA models are all in good agreement with the tested curve. However, in the low temperature stage, only viscosity fitted by VFT model is close to the tested value. Based on Navier-Stokes equation, a mathematical model of neck-down deformation of glass tube during secondary drawing is established. It is found that viscosity is the key material intrinsic factor affecting neck-down process of glass tube. The distribution of inner and outer diameters of glass tube along the drawing direction is simulated and analyzed under different feeding and drawing rates. The deviation between the steady-state dimension simulated and that actually drawn is only ±0.06 mm.
Experimental Study on Thermal Aging Performance of an RDX Based Booster
Authors: Li Hong Bin , Jin Peng Gang , Gao Zan
Published: April 2020

YC-1 booster (96.5% RDX, 3% F2641 and 0.5% graphite) was selected as the research object. Accelerated aging of YC-1 was carried out by 71°C thermal aging tests. The size changes of samples before and after thermal aging were measured. The initiation ability and shock sensitivity of the samples before and after accelerated aging were tested by steel compression test and SSGT small gap test. Through the establishment of equal proportion impact dynamics calculation model, the propagation law of shock wave generated by the explosion of A-= 9 \* ROMANIX-= 1 \* ROMANI was calculated. Test and calculation results show that: The diameter and height of samples increase with the increase of aging time. There was no significant change in the initiation ability of the samples, and the shock wave sensitivity increases first and then decreases with the increase of thermal aging time. The critical thickness of the gap corresponding to the samples aged 0 day, 4days, 19 days, 38 days and 76 days was 6.9mm, 7.0mm, 7.5mm, 8.1mm and 7.8mm, respectively. The corresponding shock wave pressure (without considering the interface reflection) in the gap was 2.91GPa, 2.85 GPa, 2.60 GPa, 2.40 GPa and 2.50 GPa respectively.
The Study and Analysis of Sinter Ores` Fragmentation Situation after Times Continued Drum Test
Authors: Wang Lian Yong , Liu Xian Gyu , Liu Chao
Published: April 2020

The article concludes the drum index and wear index of sinter ores by times continued drum test. Based on the test results, we analysis the fragmentation situation of sinter ores and the principle which effects the grade distribution under drum test. The results show that after drum test, the quality of sinter ores between 0.00-5.00mm and 10.00-16.00mm rises apparently, while other part all get lower. What`s more, when the times of drum test are same, the powdery degree will get bigger if the time is longer. When the time of drum test is same, the powdery degree will get bigger if the times are more. When the times and times are all the same, the powdery degree will be closely, which shows the results fits the Experimental errors.
Performance of 316L Stainless Steel Diffusion Welding during High Temperature Creep
Authors: An Zi Liang , Wang Wei Xin , Wang Zi Ye , Tang Yi Feng
Published: April 2020

The creep and rupture test were carried out on a non-standard specimen of 316L stainless steel (316L-SS) diffused bonding joint. And the θ-projection model was used to analyze the minimum creep strain rate and the remaining life at 500°C/6 MPa when the creep strain is 0.2%. According to the test results, design criterion for the diffusion bonding component at high temperature is established. The rupture experimental results show that the remaining life extrapolated by Larsen-Miller equation is relatively consistent with that calculated by the θ project concept method.
Simulation of Ingotless Rolling-Extruding of Rods from Alloy of Al-Zr System and Investigating into their Properties
Authors: Bespalov Vadim , Sidelnikov Sergey , Sokolov Ruslan , Chumak Alexander , Voroshilov Denis , Rudnitskiy Edvard , Durnopyanov Alexander , Voroshilova Marina
Published: April 2020

Computer simulation of the process of ingotless rolling-extruding (IRE) of aluminum alloy rods with a content of 0.15% zirconium in the Deform 3D software package performed. The temperature, speed and deformation parameters of the treatment of the investigated alloy determined under different process conditions. To check the adequacy of the models, rod samples were made on a CRE-200 laboratory unit at specified processing parameters. Using the Deform 3D software package, the forces acting on the rolls and the extruding die during the IRE determined and their comparison with tensometric experimental data presented. The mechanical properties, electrical resistivity of semi-finished products after processing by the method of ingotless rolling-extruding and for conditions of their heating to 230 °C investigated. Technological recommendations for the manufacture of deformed semi-finished products using the method of ingotless rolling-extruding are proposed.
Study on the Effect of Si-Al Components in Pulverized Coal Ash on Corrosion in Heating Surface of Biomass Boiler
Authors: Li Yun Gang , Wang Yong Zheng , Zhu Wen Bin , Sun Yu
Published: April 2020

Pulverized coal ash can be used as an additive to reduce corrosion on heating surface of biomass boiler. Biomass ash and pulverized coal ash were mixed and coated on the metal surface for experiment; the results showed that the corrosion rate of the metal decreases by adding pulverized coal ash. With the increase of additive content, the corrosion gradually reduces. The effect of different pulverized coal ash on corrosion is different, but as the proportion of pulverized coal ash increases, the effect tends to be close. When the molar content of (Si+Al)/(Na+K) is about 2 and the ratio of Si/Al is about 1, the pulverized coal ash additive works best.
2020PMD, 30-years of Translational Mobility Medicine at the time of COVID-19 outbreak: Last-minute forewords from the editor
Authors: Carraro Ugo
Published: April 2020

In the autumn of 2019, the organizers of the 2020 Padua Muscle Days planned an intense program, which was to be held from March 18 to March 21, 2020. The program included eight Scientific Sessions to occur over three full days at either Padova University or the Hotel Augustus on Euganei Hills (Padova), Italy. Abruptly, however, in early January the Coronavirus COVID-19 outbreak started in China and changed the world perspectives and expectations. In Italy, it started in Lombardy and Veneto, two main industrial areas of the country with intense connections and interchanges of people and commercial activities with China. Indeed, the virus was first isolated from a couple of Chinese tourists, who inadvertently incubated the infection during their visit to many towns in Italy. Within the following two weeks, the epidemic had the first Italian cases and victims in an area south of Milan and in a Village of the Euganei Hills (Vo Euganeo, Padova). The village was immediately quarantined, but it was too late. The virus had escaped the area. Thus, it was a mandatory, though difficult decision (made even before the Italian National Government posted rules to be followed to decrease spread of the infection), to post-pone the Padua Muscle Days meeting from 18-21 March, 2020 to 25-28 November, 2020. Luckily, the vast majority of organizers, chairs, speakers, and attendees accepted the decision and have assured their presence in late November, despite the coincidence with the Thanksgiving holiday in the US. Currently, the only changes in the program are the new dates; however, it is difficult to forecast the future. Anyhow, the rationale of the decision to post-pone 2020PMD was reinforced by the actions of many organizers of international events. One of the most recent examples is the March 6, 2020 decision of the leaders of the Experimental Biology Host Societies to cancel Experimental Biology (EB) 2020, set to take place April 4–7 in San Diego, California, USA. All these active civil responses to world dangers are mandatory to avoid those military responses that are easy to start, but provide the worst results. How do we not lose half of the 2020 year? The option is to try to achieve some of the goals of the meeting by long-distance communications. Thus, the Collection of Abstracts will be, as originally planned, e-published in this 30(1) 2020 Issue of the European Journal of Translational Myology (EJTM) together with the many EJTM Communications submitted by speakers and attendees of the 2020PMD. We may also start the process that will implement EMMA, the European Mobility Medicine Association, by circulating a proposal and inviting comments.
On Trudinger-type Inequalities in Orlicz-Morrey Spaces of an Integral Form
Authors: Hurri-Syrjänen Ritva , Ohno Takao , Shimomura Tetsu
Published: April 2020

We give Trudinger-type inequalities for Riesz potentials of functions in Orlicz-Morrey spaces of an integral form over non-doubling metric measure spaces. Our results are new even for the doubling metric measure setting. In particular, our results improve and extend the previous results in Morrey spaces of an integral form in the Euclidean case.
Complex eigenvalue bounds for a Schrödinger operator on the half line
Authors: Ferrulli Francesco , Laptev Ari
Published: April 2020

We derive some bounds on the location of complex eigenvalues for a family of Schrödinger operators

H_{0,\nu}

defined on the positive half line and subject to integrable complex potential. We generalise the results obtained in [14] where the operator does not have a Hardy term and also include the analysis for potentials belonging to weighted

L^p

spaces. Some information on the geometry of the complex region which bounds the eigenvalues of the radial Schrödinger multidimensional operator are then recovered.
Weighted estimates for diffeomorphic extensions of homeomorphisms
Authors: Xu Haiqing
Published: April 2020

Let

\Omega \subset \mathbb R^2

be an internal chord-arc domain and

\varphi : \mathbb S^1 \rightarrow \partial \Omega

be a homeomorphism. Then there is a diffeomorphic extension

h : \mathbb D \rightarrow \Omega

of

\varphi

. We study the relationship between weighted integrability of the derivatives of

h

and double integrals of

\varphi

and of

\varphi^{-1}

.
Two weight inequalities for positive operators: doubling cubes
Authors: Chen Wei , Lacey Michael T.
Published: April 2020

For the maximal operator

M

on

\mathbb{R}^{d}

, and

1 < p,\rho < \infty

, there is a finite constant

D=D _{p, \rho }

so that this holds. For all weights

w,\sigma

on

\mathbb{R}^{d}

, the operator

M(\sigma \cdot)

is bounded from

L^{p}(\sigma )\to L^{p}(w)

if and only if the pair of weights

(w,\sigma)

satisfy the two weight

A_{p}

condition, and this testing inequality holds:

\int_{Q} M(\sigma \mathbf 1_{Q})^{p} dw \lesssim \sigma(Q),

for all cubes

Q

for which there is a cube

P\supset Q

satisfying

\sigma(P) \leq D\sigma(Q)

, and

\ell(P) \geq \rho \ell(Q)

. This was recently proved by Kangwei Li and Eric Sawyer. We give a short proof, which is easily seen to hold for several closely related operators.
Dynamic properties of the dynamical system SFnm(X), SFnm(f))
Authors: Barragán Franco , Santiago-Santos Alicia , Tenorio Jesús F.
Published: April 2020

Let X be a continuum and let n be a positive integer. We consider the hyperspaces Fn(X) and SFn(X). If m is an integer such that n > m ≥ 1, we consider the quotient space SFnm(X). For a given map f : X → X, we consider the induced maps Fn(f) : Fn(X) → Fn(X), SFn(f) : SFn(X) → SFn(X) and SFnm(f) : SFnm(X) → SFnm(X). In this paper, we introduce the dynamical system (SFnm(X), SFnm (f)) and we investigate some relationships between the dynamical systems (X, f), (Fn(X), Fn(f)), (SFn(X), SFn(f)) and (SFnm(X), SFnm(f)) when these systems are: exact, mixing, weakly mixing, transitive, totally transitive, strongly transitive, chaotic, irreducible, feebly open and turbulent.
Existence of Picard operator and iterated function system
Authors: Garg Medha , Chandok Sumit
Published: April 2020

In this paper, we define weak θm− contraction mappings and give a new class of Picard operators for such class of mappings on a complete metric space. Also, we obtain some new results on the existence and uniqueness of attractor for a weak θm− iterated multifunction system. Moreover, we introduce (α, β, θm)− contractions using cyclic (α, β)− admissible mappings and obtain some results for such class of mappings without the continuity of the operator. We also provide an illustrative example to support the concepts and results proved herein.
Predicting the maximum aa/Ap index through its relationship with the preceding minimum
Authors: Du Zhanle
Published: April 2020

Abstract. Predicting the strength and peak time of geomagnetic activity for the ensuing cycle 25 is important in space weather service for planning future space missions. The minimum aa geomagnetic index around the solar minimum has been often used to predict the maximum amplitude of sunspot cycle, but seldom used to directly predict the maximum aa index. This study analyzed the relationships between the maxima and minima of both the geomagnetic aa and Ap indices for the 11-year cycle. The maximum aa index is found to be well correlated to the preceding minimum with a correlation coefficient of r = 0.860. As a result, the maximum aa index for the ensuing cycle 25 is predicted to be aamax(25) = 26.9 ± 2.6. This value is equivalent to Apmax(25) = 17.3 ± 1.8 ± 1.2 if employing the high correlation between aa and Ap (r = 0.939). The maximum Ap index is also found to be well correlated to the preceding minimum with a correlation coefficient of r = 0.862. Based on this correlation, the maximum Ap index is predicted to be a slightly higher value of Apmax(25) = 19.0 ± 1.6. The rise time of the aa (Ap) index for the 11-year cycle is found to be nearly uncorrelated to the following maximum, r = −0.16 (−0.17). If the data point for cycle 24 (which is far from others) were not considered, the rise time of the Ap index for the 11-year cycle would be weakly correlated to the following maximum, r = −0.404 at a confidence level of 62 %. The rise time for cycle 25 would be roughly estimated to be 89.9 ± 31.6 (months), implying that the geomagnetic activity for the ensuing cycle 25 would peak around April 2025 ± 32 months.
Structural characterization of the equatorial F region plasma irregularities in the multifractal context
Authors: Joshi Neelakshi , Rosa Reinaldo R. , Savio Siomel , Kherani Esfhan Alam , de Meneses Francisco Carlos , Stephany Stephan , Muralikrishna Polinaya
Published: April 2020

Abstract. In the emerging ionosphere–space–weather paradigm, investigating the dynamical properties of ionospheric plasma irregularities using advanced computational nonlinear algorithms provide new insights into their turbulent-seeming nature, for instance, the evidence of energy distribution via a multiplicative cascade. In this study, we present a multifractal analysis of the equatorial F region in situ data obtained from two different experiments performed at Alcântara (2.4∘ S, 44.4∘ W), Brazil, to explore their scaling structures. The first experiment observed several medium- to large-scale plasma bubbles whereas the second experiment observed vertical uplift of the base of the F region. The multifractal detrended fluctuation analysis and the p-model fit are used to analyze the plasma density fluctuation time series. The result shows the presence of multifractality with degree of multifractality 0.53–0.93 and 0.3≤p≤0.4 cascading probability for the first experiment. Other experimental data also exhibit multifractality with degree of multifractality 0.19–0.27 and 0.42≤p≤0.44 cascading probability in ionospheric plasma irregularities. Our results confirm the nonhomogeneous nature of plasma irregularities and characterize the underlying nonhomogeneous multiplicative cascade hypothesis in the ionospheric medium. Differences in terms of scaling and complexity in the data belonging to different types of phenomena are also addressed.
Oxygen isotope composition of waters recorded in carbonates in strong clumped and oxygen isotopic disequilibrium
Authors: Thaler Caroline , Katz Amandine , Bonifacie Magali , Ménez Bénédicte , Ader Magali
Published: April 2020

Abstract. Paleoenvironmental reconstructions, which are mainly retrieved
from oxygen isotope (δ18O) and clumped isotope (Δ47) compositions of carbonate minerals, are compromised when carbonate
precipitation occurs in isotopic disequilibrium. To date, knowledge of
these common isotopic disequilibria, known as vital effects in biogenic
carbonates, remains limited, and the potential information recorded by
δ18O and Δ47 offsets from isotopic equilibrium
values is largely overlooked. Additionally, in carbonates formed in isotopic
equilibrium, the use of the carbonate δ18O signature as a
paleothermometer relies on our knowledge of the paleowaters' δ18O value, which is often assumed. Here, we report the largest Δ47 offsets observed to date (as much as −0.270 ‰),
measured on microbial carbonates that are strongly linked to carbonate
δ18O offsets (−25 ‰) from equilibrium.
These offsets are likely both related to the microorganism metabolic
activity and yield identical erroneous temperature reconstructions.
Unexpectedly, we show that the δ18O value of the water in which
carbonates precipitated, as well as the water–carbonate δ18O
fractionation dependence on temperature at equilibrium, can be retrieved from
these paired δ18O and Δ47 disequilibrium values
measured in carbonates. The possibility to retrieve the δ18O
value of paleowaters, sediments' interstitial waters or organisms' body
water at the carbonate precipitation loci, even from carbonates formed in
isotopic disequilibrium, opens long-awaited research avenues for both
paleoenvironmental reconstructions and biomineralization studies.
Impact of ambient conditions on the Si isotope fractionation in marine pore fluids during early diagenesis
Authors: Geilert Sonja , Grasse Patricia , Doering Kristin , Wallmann Klaus , Ehlert Claudia , Scholz Florian , Frank Martin , Schmidt Mark , Hensen Christian
Published: April 2020

Abstract. Benthic fluxes of dissolved silicon (Si) from sediments into the water
column are driven by the dissolution of biogenic silica (bSiO2) and
terrigenous Si minerals and modulated by the precipitation of authigenic Si
phases. Each of these processes has a specific effect on the isotopic
composition of silicon dissolved in sediment pore fluids, such that the
determination of pore fluid δ30Si values can help to decipher
the complex Si cycle in surface sediments. In this study, the δ30Si signatures of pore fluids and bSiO2 in the Guaymas Basin
(Gulf of California) were analyzed, which is characterized by high
bSiO2 accumulation and hydrothermal activity. The δ30Si
signatures were investigated in the deep basin, in the vicinity of a
hydrothermal vent field, and at an anoxic site located within the pronounced
oxygen minimum zone (OMZ). The pore fluid δ30Sipf
signatures differ significantly depending on the ambient conditions. Within
the basin, δ30Sipf is essentially uniform, averaging
+1.2±0.1 ‰ (1 SD). Pore fluid δ30Sipf values from within the OMZ are significantly lower
(0.0±0.5 ‰, 1 SD), while pore fluids close to the
hydrothermal vent field are higher (+2.0±0.2 ‰,
1SD). Reactive transport modeling results show that the δ30Sipf is mainly controlled by silica dissolution (bSiO2 and
terrigenous phases) and Si precipitation (authigenic aluminosilicates).
Precipitation processes cause a shift to high pore fluid δ30Sipf signatures, most pronounced at the hydrothermal site.
Within the OMZ, however, additional dissolution of isotopically depleted Si
minerals (e.g., clays) facilitated by high mass accumulation rates of
terrigenous material (MARterr) is required to promote the low δ30Sipf signatures, while precipitation of authigenic
aluminosilicates seems to be hampered by high water ∕ rock ratios. Guaymas OMZ
δ30Sipf values are markedly different from those of the
Peruvian OMZ, the only other marine OMZ setting where Si isotopes have been
investigated to constrain early diagenetic processes. These differences
highlight the fact that δ30Sipf signals in OMZs worldwide
are not alike and each setting can result in a range of δ30Sipf values as a function of the environmental conditions. We
conclude that the benthic silicon cycle is more complex than previously
thought and that additional Si isotope studies are needed to decipher the
controls on Si turnover in marine sediment and the role of sediments in the
marine silicon cycle.
The Half-order Energy Balance Equation, Part 1: The homogeneous HEBE and long memories
Authors: Lovejoy Shaun
Published: April 2020

Abstract. The original Budyko–Sellers type 1-D energy balance models (EBMs) consider the Earth system averaged over long times and applies the continuum mechanics heat equation. When these and the more phenomenological zero (horizontal) – dimensional box models are extended to include time varying anomalies, they have a key weakness: neither model explicitly nor realistically treats the surface radiative – conductive surface boundary condition that is necessary for a correct treatment of energy storage. In this first of a two part series, we apply standard Laplace and Fourier techniques to the continuum mechanics heat equation, solving it with the correct radiative – conductive BC's obtaining an equation directly for the surface temperature anomalies in terms of the anomalous forcing. Although classical, this equation is half – not integer – ordered: the Half - ordered Energy Balance Equation (HEBE). A quite general consequence is that although Newton's law of cooling holds, that the heat flux across surfaces is proportional to a half (not first) ordered derivative of the surface temperature. This implies that the surface heat flux has a long memory, that it depends on the entire previous history of the forcing, the relationship is no longer instantaneous. We then consider the case where the Earth is periodically forced. The classical case is diurnal heat forcing; we extend this to annual conductive – radiative forcing and show that the surface thermal impedance is a complex valued quantity equal to the (complex) climate sensitivity. Using a simple semi-empirical model, we show how this can account for the phase lag between the summer maximum forcing and maximum surface temperature Earth response. In part II, we extend all these results to spatially inhomogeneous forcing and to the full horizontally inhomogeneous problem with spatially varying specific heats, diffusivities, advection velocities, climate sensitivities. We consider the consequences for macroweather forecasting and climate projections.
Interacting tipping elements increase risk of climate domino effects under global warming
Authors: Wunderling Nico , Donges Jonathan F. , Kurths Jürgen , Winkelmann Ricarda
Published: April 2020

Abstract. There exists a range of subsystems in the climate system exhibiting threshold behaviour which could be triggered under global warming within this century resulting in severe consequences for biosphere and human societies. While their individual tipping thresholds are fairly well understood, it is of yet unclear how their interactions might impact the overall stability of the Earth's climate system. This cannot be studied yet with state-of-the-art Earth system models due to computational constraints as well as missing and uncertain process representations of some tipping elements. Here, we explicitly study the effects of known physical interactions between the Greenland and West Antarctic Ice Sheet, the Atlantic Meridional Overturning Circulation, the El-Nino Southern Oscillation and the Amazon rainforest using a conceptual network approach. We analyse the risk of domino effects being triggered by each of the individual tipping elements under global warming in equilibrium experiments, propagating uncertainties in critical temperature thresholds and interaction strengths via a Monte-Carlo approach. Overall, we find that the interactions tend to destabilise the network. Furthermore, our analysis reveals the qualitative role of each of the five tipping elements showing that the polar ice sheets on Greenland and West Antarctica are oftentimes the initiators of tipping cascades, while the AMOC acts as a mediator, transmitting cascades. This implies that the ice sheets, which are already at risk of transgressing their temperature thresholds within the Paris range of 1.5 to 2 °C, are of particular importance for the stability of the climate system as a whole.
Focus on glaciers: a geo-photo exposition on the vanishing beauty
Authors: Rossi Giuliana , Bohm Gualtiero , Saraò Angela , Cotterle Diego , Facchin Lorenzo , Giurco Paolo , Lucchi Renata Giulia , Musco Maria Elena , Petrera Francesca , Picotti Stefano , Salon Stefano
Published: April 2020

Abstract. The encounter of scientific research, respect for the environment, and passion for photography created, throughout the years, an exceptional heritage of images shot by researchers and technicians of the National Institute of Oceanography and Applied Geophysics – OGS, during the scientific expeditions all over the world. The OGS researches in the fields of Earth and Ocean Sciences, to widen the scientific knowledge, to raise the environmental awareness and conservation of natural resources, and to mitigate the natural risks. In this paper, we describe the exposition of artistic pictures that we set up to draw the attention of the general public to the effects of global warming. In our exhibition, the glaciers run the performance, with the infinite grey-blue shadows, the shapes, worthy of a great sculptor, the contact with the rock or the sea, sometimes sharp and dramatic, sometimes so nuanced to appear as a water-colour. The beauty of the images attracts the attention of the public on unknown realities and allows us to document the dramatic retreat of the Alpine glaciers, and to show the majesty of the Arctic and Antarctic landscapes jeopardised by the climate change. Glaciers are, in fact, almost all in a negative mass-balance, and with the present warming trend, they will vanish. The authors were present at the exhibition, and the visitors could satisfy their curiosity on the research issues, the context in which the pictures were shot, technical details, or aesthetic choices. The choice of the location allowed to reach a broad public of adults, in the working-age, often challenging to reach. The paper presents a summary of this experience, of importance both for the authors and the visitors.
The Making of the New European Wind Atlas – Part 2: Production and Evaluation
Authors: Dörenkämper Martin , Olsen Bjarke T. , Witha Björn , Hahmann Andrea N. , Davis Neil N. , Barcons Jordi , Ezber Yasemin , García-Bustamante Elena , González-Rouco J. Fidel , Navarro Jorge , Sastre-Marugán Mariano , Sīle Tija , Trei Wilke , Žagar Mark , Badger Jake , Gottschall Julia , Sanz Rodrigo Javier , Mann Jakob
Published: April 2020

Abstract. This is the second of two papers that document the creation of the New European Wind Atlas (NEWA). In Part 1, we described the sensitivity experiments and accompanying evaluation done to arrive at the final mesoscale model setup used to produce the mesoscale wind atlas. In this paper, Part 2, we document how we made the final wind atlas product, covering both the production of the mesoscale climatology generated with the Weather Research and Forecasting (WRF) model and the microscale climatology generated with the Wind Atlas Analysis and Applications Program (WAsP). The paper includes a detailed description of the technical and practical aspects that went into running the mesoscale simulations and the downscaling using WAsP. We show the main results from the final wind atlas and present a comprehensive evaluation of each component of the NEWA model chain using observations from a large set of tall masts located all over Europe. The added value of the WRF and WAsP downscaling of wind climatologies is evaluated relative to the performance of the driving ERA5 reanalysis and shows that the WRF downscaling reduces the mean wind speed bias and spread relative to that of ERA5 from −1.50 ± 1.30 to 0.02 ± 0.78 ms−1. The WAsP downscaling has an added positive impact relative to that of the WRF model in simple terrain. In complex terrain, where the assumptions of the linearised flow model break down, both the mean bias and spread in wind speed are worse than the mesoscale results.
Physics-inspired integrated space-time Artificial Neural Networks for regional groundwater flow modeling
Authors: Ghaseminejad Ali , Uddameri Venkatesh
Published: April 2020

Abstract. An integrated space-time Artificial Neural Network (ANN) model inspired by the governing groundwater flow equation was developed to test whether a single ANN is capable of modeling regional groundwater flow systems. Model-independent entropy measures and random forest (RF) based feature selection procedures were used to identify suitable inputs for ANNs. L2 regularization, 5-fold cross-validation, and adaptive stochastic gradient descent (ADAM) algorithm led to a parsimonious ANN model for a 30 691 km2 agriculturally intensive area in the Ogallala Aquifer of Texas. The model testing at 38 independent wells during the 1956–2008 calibration period showed no overfitting issues and highlighted the model's ability to capture both the observed spatial dependence and temporal variability. The forecasting period (2009–2015) was marked by extreme climate variability in the region and served to evaluate the extrapolation capabilities of the model. While ANN models are universal interpolators, the model was able to capture the general trends and provided groundwater level estimates that were better than using historical means. Model sensitivity analysis indicated that pumping was the most sensitive process. Incorporation of spatial variability was more critical then capturing groundwater level persistence. The use of the standardized precipitation-evapotranspiration (SPEI) index as a surrogate for pumping was generally adequate but was unable to capture the heterogeneous groundwater extraction preferences of farmers under extreme climate conditions.
Design and implementation of a mobile device app for network-based earthquake early warning systems (EEWSs): application to the PRESTo EEWS in southern Italy
Authors: Colombelli Simona , Carotenuto Francesco , Elia Luca , Zollo Aldo
Published: April 2020

Abstract. A fundamental feature of any earthquake early warning system is the ability
of rapidly broadcast earthquake information to reach a wide audience of potential
end users and stakeholders, in an intuitive, customizable way. Smartphones
and other mobile devices are nowadays continuously connected to the Internet
and represent the ideal tools for earthquake alerts dissemination to inform
a large number of users about the potential damaging shaking of an impending
earthquake. Here we present a mobile app (named ISNet EWApp or simply EWApp) for Android devices which
can receive the alerts generated by a network-based Early Warning system.
Specifically, the app receives the earthquake alerts generated by the PRESTo
EEWS, which is currently running on the accelerometric stations of the
Irpinia Seismic Network (ISNet) in southern Italy. In the absence of alerts,
EWApp displays the standard bulletin of seismic events that have occurred within
the network. In the event of a relevant earthquake, the app has a
dedicated module to predict the expected ground-shaking intensity and the
available lead time at the user's position and to provide customized messages
to inform the user about the proper reaction to adopt during the alert. We first
present the architecture of both the network-based system and EWApp and then describe its essential operational modes. The app is designed in a way
that is easily exportable to any other network-based early warning system.
Baroclinic and barotropic instabilities in planetary atmospheres: energetics, equilibration and adjustment
Authors: Read Peter , Kennedy Daniel , Lewis Neil , Scolan Hélène , Tabataba-Vakili Fachreddin , Wang Yixiong , Wright Susie , Young Roland
Published: April 2020

Abstract. Baroclinic and barotropic instabilities are well known as the mechanisms responsible for the production of the dominant energy-containing eddies in the atmospheres of Earth and several other planets, as well as Earth's oceans. Here we consider insights provided by both linear and nonlinear instability theories into the conditions under which such instabilities may occur, with reference to forced and dissipative flows obtainable in the laboratory, in simplified numerical atmospheric circulation models and in the planets of our solar system. The equilibration of such instabilities is also of great importance in understanding the structure and energetics of the observable circulation of atmospheres and oceans. Various ideas have been proposed concerning the ways in which baroclinic and barotropic instabilities grow to a large amplitude and saturate whilst also modifying their background flow and environment. This remains an area that continues to challenge theoreticians and observers, though some progress has been made. The notion that such instabilities may act under some conditions to adjust the background flow towards a critical state is explored here in the context of both laboratory systems and planetary atmospheres. Evidence for such adjustment processes is found relating to baroclinic instabilities under a range of conditions where the efficiency of eddy and zonal-mean heat transport may mutually compensate in maintaining a nearly invariant thermal structure in the zonal mean. In other systems, barotropic instabilities may efficiently mix potential vorticity to result in a flow configuration that is found to approach a marginally unstable state with respect to Arnol'd's second stability theorem. We discuss the implications of these findings and identify some outstanding open questions.
Cenozoic deformation in the Tauern Window (Eastern Alps) constrained by in situ Th-Pb dating of fissure monazite
Authors: Ricchi Emmanuelle , Bergemann Christian A. , Gnos Edwin , Berger Alfons , Rubatto Daniela , Whitehouse Martin J. , Walter Franz
Published: April 2020

Abstract. Thorium–lead (Th-Pb) crystallization
ages of hydrothermal monazites
from the western, central and eastern Tauern Window provide new insights
into Cenozoic tectonic evolution of the Tauern metamorphic dome. Growth
domain crystallization ages range from 21.7 ± 0.4 to 10.0 ± 0.2 Ma.
Three major periods of monazite growth are recorded between
∼ 22–20 (peak at 21 Ma), 19–15 (major peak at 17 Ma) and
14–10 Ma (major peak around 12 Ma), respectively, interpreted to be
related to prevailing N–S shortening, in association with E–W extension,
beginning strike-slip movements and reactivation of strike-slip faulting.
Fissure monazite ages largely overlap with zircon and apatite fission track
data. Besides tracking the thermal evolution of the Tauern dome, monazite
dates reflect episodic tectonic movement along major shear zones that took
place during the formation of the dome. Geochronological and structural data
from the Pfitschtal area in the western Tauern Window show the existence of
two cleft generations separated in time by 4 Ma and related to strike-slip
to oblique-slip faulting. Moreover, these two phases overprint earlier
phases of fissure formation.
Highlights.
In situ dating of hydrothermal monazite-(Ce). New constraints on the exhumation of the Tauern metamorphic dome. Distinct tectonic pulses recorded from east to west.
Deciphering the metamorphic evolution of the Pulo do Lobo metasedimentary domain (SW Iberian Variscides)
Authors: Pérez-Cáceres Irene , Martínez Poyatos David Jesús , Vidal Olivier , Beyssac Olivier , Nieto Fernando , Simancas José Fernando , Azor Antonio , Bourdelle Franck
Published: April 2020

Abstract. The Pulo do Lobo domain is one of the units exposed within the orogenic
suture zone between the Ossa-Morena and the South Portuguese zones in the SW
Iberian Variscides. This metasedimentary unit has been classically
interpreted as a Rheic subduction-related accretionary prism formed during
pre-Carboniferous convergence and eventual collision between the South
Portuguese Zone (part of Avalonia) and the Ossa-Morena Zone (peri-Gondwanan
terrane). Discrete mafic intrusions also occur within the dominant Pulo do
Lobo metapelites, related to an intra-orogenic Mississippian transtensional
and magmatic event that had a significant thermal input. Three different
approaches have been applied to the Devonian–Carboniferous phyllites and
slates of the Pulo do Lobo domain in order to study their poorly known
low-grade metamorphic evolution. X-ray diffraction (XRD) was used to
identify the mineralogy and measure crystallographic parameters (illite
“crystallinity” and K-white mica b-cell dimension). Compositional maps of
selected samples were obtained from electron probe microanalysis, which
allowed for processing with XMapTools software, and chlorite semiempirical and
thermodynamic geothermometry was performed. Thermometry based on Raman
spectroscopy of carbonaceous material (RSCM) was used to obtain peak
temperatures. The microstructural study shows the existence of two phyllosilicate growth
events in the chlorite zone, the main one (M1) related to the
development of a Devonian foliation S1 and a minor one (M2)
associated with a crenulation cleavage (S2) developed in middle–upper
Carboniferous times. M1 entered well into epizone (greenschist facies)
conditions. M2 conditions were at lower temperature, reaching the
anchizone–epizone boundary. These data accord well with the angular
unconformity that separates the Devonian and Carboniferous formations of the
Pulo do Lobo domain. The varied results obtained by the different approaches
followed, combined with microstructural analysis, provide different
snapshots of the metamorphic history. Thus, RSCM temperatures are higher in
comparison with the other methods applied, which is interpreted to reflect a
faster re-equilibration during the short-lived thermal Mississippian event.
Regarding the metamorphic pressure, the data are very homogeneous: very low
celadonite content (0 %–10 %) in muscovite (and low values of K-white mica
b-cell dimension; 8.995 Å mean value), indicating a low
pressure–temperature gradient, which is unexpected in a subduction-related
accretionary prism.

Highlights
A multidisciplinary approach has been applied to study the metamorphism of
the Pulo do Lobo metapelites. Devonian metamorphism entered epizone conditions. Carboniferous metamorphism reached the anchizone–epizone boundary. The inferred low-pressure gradient is incompatible with a subduction-related
accretionary prism.
Seasonal and interannual variability of sea-ice state variables: Observations and predictions for landfast ice in northern Alaska and Svalbard
Authors: Oggier Marc , Eicken Hajo , Jin Meibing , Høyland Knut
Published: April 2020

Abstract. Validation of sea-ice models, representation of sea-ice processes in large-scale models, and regional planning around ice use and hazards requires climatological ice property data. We summarize key ice properties, in particular temperature and salinity, representative of broader Arctic conditions, from long-term observations near Utqiaġvik, Alaska and Van Mijen Fjord, Svalbard. Additionally, we simulate salinity and temperature profiles using the Los Alamos sea-ice model (CICE) in stand-alone mode, forced with meteorological data for both locations. We compare observations and model results by aggregating profiles using a degree day model and statistical analysis to create ice property climatologies, which describe the seasonal evolution of sea ice. During the growth season, the CICE model accurately replicates ice property evolution for both salinity (R = 0.7) and temperature (R = 0.9). While the model initiates ice desalination at melt onset, and reproduces the temperature field well through melt (R = 0.9), model salinities later tend towards an asymptotic value of 5 ‰ (R = 0.3). This suggests that the model does not fully capture the desalination processes and their impact on ice physico-chemical properties during the melt season. Overall, the standard deviation of the model remains similar to the natural sea-ice variability throughout the season. Despite mismatches during the melt season, the CICE model shows promise for simulating the seasonal evolution of salinity and temperature profiles, which may serve as proxies for bulk ice properties that constrain transport of heat and mass through sea ice. Our findings highlight the necessity for a large number of observations throughout the year to create an effective model benchmarking dataset.
The Life Cycle of Upper-Level Troughs and Ridges: A Novel Detection Method, Climatologies and Lagrangian Characteristics
Authors: Schemm Sebastian , Sprenger Michael
Published: April 2020

Abstract. A novel method is introduced to identify and track the life cycle of upper-level troughs and ridges. The aim is to close the existing gap between methods that detect the initiation phase of upper-level Rossby wave development and methods that detect Rossby wave breaking and decaying waves. The presented method quantifies the horizontal trough and ridge orientation and identifies the corresponding trough and ridge axes. The trough and ridge axes allow us to study the dynamics of pre- and post-trough or ridge regions separately. The tracking allows us to study the temporal evolution of the trough or ridge orientation. The method is based on the curvature of the geopotential height at a given isobaric surface and is computationally efficient. First, the algorithm is introduced in detail, and several illustrative applications, such as a downstream development from the North Atlantic into the Mediterranean, and seasonal climatologies are discussed. For example, the climatological trough and ridge orientations reveal strong zonal and meridional asymmetry. Over land, most troughs and ridges are anticyclonically oriented, while they are cyclonically oriented over the main oceanic storm tracks. The cyclonic orientation increases towards the poles, while the anticyclonic orientation increases towards the equator. Trough detection frequencies are climatologically high downstream of the Rocky Mountains and over East Asia and Eastern Europe, but are remarkably low downstream of Greenland. Furthermore, the detection frequencies of troughs are high at the end of the Pacific storm track, but no comparable signal is seen over the North Atlantic. During El Niño-affected winters, troughs and ridges tilt anomalously strong cyclonically over North America and the North Atlantic, in agreement with previous findings based on traditional variance-based diagnostics such as E vectors. During La Niña the situation is essentially reversed. Finally, the identified troughs and ridges are used as starting points for 24-hour backward parcel trajectories, and a discussion of the distribution of pressure, potential temperature and potential vorticity changes along the flow path is provided to give insight into the three-dimensional nature of troughs and ridges.
The Impact of On-duty Emergency Medicine Trainees on Left-Without-Being-Seen Rates in an Academic Emergency Department
Authors: Jenkins Dominic , Pathan Sameer , Moinudheen Jibin , Qureshi Raheel , Qureshi Isma , Farook Saleem , Thomas Stephen
Published: April 2020

Objectives: One of the endpoints for assessing the emergency department (ED) performance is the left-without-being-seen (LWBS) proportion. This study aimed to evaluate the impact of increasing proportions of on-duty emergency medicine (EM) trainees on LWBS rates in clinical shifts. Methods: The study was conducted at an urban-academic-ED (annual census: 452,757) over a period of one year. We employed multivariate linear regression (p < 0.05) defining significance to identify and adjust for multiple LWBS influencers related to patient care. Results: After analyzing over 1098 shifts, the median LWBS rate was 8.9% (interquartile range 5.3% to 13.5%). The increasing number of EM trainees in the ED did not adversely impact the LWBS; the opposite was noted. In univariate analysis, the increasing proportion of on-duty EM trainee physicians was significantly (p < 0.001) associated with a decrease in the LWBS rates. The multivariate model adjusted for the statistically significant and confounding LWBS influencers, with an absolute increase of 1% in trainees’ proportion of overall on-duty physician coverage, was associated with an absolute decrease of 2.1% in LWBS rates (95% confidence interval 0.43% to 3.8%, p = 0.014). Conclusions: At the study site, there was a statistically and operationally significant improvement in LWBS associated with partial replacement of board-certified specialist-grade EM physicians with EM residents and fellow trainees.
Rubén Darío y el origen de la modernidad poética en Hispanoamérica.
Authors: Ruiz Víctor
Published: April 2020

En su libro Celebración al Modernismo Saúl Yurkievich afirma que la Vanguardia, en su afán por imponer un presente vertiginoso, impulsado hacia el futuro, borró todo legado con el pasado inmediato. Los vanguardistas renegaron categóricamente de todas las escuelas anteriores a ellos, “sin vislumbrar, como en antas revoluciones, que todos sus  propósitos y logro habían germinado poco antes”. En pocas palabras, el crítico argentino confirma lo que Octavio Paz en Los Hijos de Limo llamó la tradición de la ruptura, ese vaivén de fracturas, interrupciones, cambios y rebeliones que se suceden de una generación a otra. Según Paz nuestra tradición está hecha de interrupciones y cada ruptura con ella es un regreso al pasado, es decir, un regreso a la tradición: la tradición de la ruptura
Hongos del Caribe nicaragüense. Resumen de especies de dos estudios hechos en la Reserva Biológica Indio Maíz
Authors: Saldívar Gómez Iris Lilliam
Published: April 2020

En la última década han sido realizados dos estudios importantes sobre hongos en el Caribe nicaragüense. Ambos estudios están aislados en el tiempo, sin embargo proveen de una importante base científica que ayuda a entender la composición de la biota fúngica de nuestro Caribe. Este artículo es un resumen de ambas investigaciones en las cuales se presenta una lista de las especies de hongos encontradas en ambos estudios y se muestran con especial interés algunas especies que tienen importancia por su comestibilidad, El artículo contiene además fotografías de hongos que incluyen algunas de las especies mencionadas.
Murciélagos (quirópteros) del Centro de Transferencia Agroforestal CeTAF, en Bluefields
Authors: Siu Estrada Eduardo , Ebanks Mongalo Billy , Suárez Sánchez Juan , Octavio Saldaña Jordan Ch. , Aguirre Obando Yury , Rivas S. Enoc
Published: April 2020

Esta investigación es un aporte que enriquece los datos sobre mamíferos del país. En el Caribe nicaragüense no se ha realizado hasta la fecha una caracterización taxonómica de las especies de murciélagos. En este número de Wani tenemos el gusto de publicar un estudio que identifica una lista de especies de quirópteros que habitan en la Región Autónoma de la Costa Caribe Sur. Para tal efecto fueron establecidas dos zonas de muestreos en las cuales se utilizaron dos redes de neblina de medida estándar (12 m x 2.5 m y 30 mm de luz de malla), una por cada sitio de muestreo. Esto permitió identificar 11 especies de murciélagos distribuidos en tres familias y cuatro sub órdenes. Fueron identificadas especies insectívoras y frutívoras.