bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analytical friction force compensation of flow curves out of layer compression tests with the pin extrusion test
Authors: Lenzen Matthias , Kraus Martin , Merklein Marion 
Published: April 2020

AbstractFor conventional material models like Yld2000-2d or BBC05 the equi-biaxial yield strength is required for the parameter identification. In this context, a commonly used test setup is the hydraulic bulge test. However, an inaccuracy in the characterization of the initial yield strength is present in the hydraulic bulge test. Due to the evaluation of the resulting curvature of the specimen, that is nearly infinite at the onset of yielding, the calculated stress can significant vary. Another proposed test setup for the characterization of the equi-biaxial stress state is the layer compression test. Here, the onset of yielding can be characterized with sufficient accuracy. The disadvantage in this test is the friction between stack and tool that leads to an overestimation of the flow curve. Thus, robust and experimental based friction compensation should be used, to gain a comparable hardening behaviour as in the hydraulic bulge test. In this contribution, the friction in the layer compression test is compensated by characterization of the tribological conditions. Thus, the tribological system consisting of workpiece surface, tool surface and lubricant is characterized using pin extrusion tests. The friction is analysed for the two steel grades DC06 and DP600 and the aluminium AA5182. With the identified friction factors, the measured testing force in the layer compression test is reduced by the portion of friction. For verification, hydraulic bulge tests, which are approximately friction free, are performed and compared with the resulting flow curves of the layer compression tests. Results confirm, that a friction compensation of the layer compression tests lead to a significant improvement of the resulting material parameters in comparison to the hydraulic bulge tests. Additional, a new method for the friction factor characterization is presented that uses in the stress difference of flow curves characterized in hydraulic bulge tests and layer compression tests.
Simulation of elliptic and hypo-elliptic conditional diffusions
Authors: Bierkens Joris , van der Meulen Frank , Schauer Moritz 
Published: April 2020

AbstractSuppose X is a multidimensional diffusion process. Assume that at time zero the state of X is fully observed, but at time
$T>0$
only linear combinations of its components are observed. That is, one only observes the vector
$L X_T$
for a given matrix L. In this paper we show how samples from the conditioned process can be generated. The main contribution of this paper is to prove that guided proposals, introduced in [35], can be used in a unified way for both uniformly elliptic and hypo-elliptic diffusions, even when L is not the identity matrix. This is illustrated by excellent performance in two challenging cases: a partially observed twice-integrated diffusion with multiple wells and the partially observed FitzHugh–Nagumo model.
Thinning and multilevel Monte Carlo methods for piecewise deterministic (Markov) processes with an application to a stochastic Morris–Lecar model
Authors: Lemaire Vincent , Thieullen MichÉle , Thomas Nicolas 
Published: April 2020

AbstractIn the first part of this paper we study approximations of trajectories of piecewise deterministic processes (PDPs) when the flow is not given explicitly by the thinning method. We also establish a strong error estimate for PDPs as well as a weak error expansion for piecewise deterministic Markov processes (PDMPs). These estimates are the building blocks of the multilevel Monte Carlo (MLMC) method, which we study in the second part. The coupling required by the MLMC is based on the thinning procedure. In the third part we apply these results to a two-dimensional Morris–Lecar model with stochastic ion channels. In the range of our simulations the MLMC estimator outperforms classical Monte Carlo.
Joint temporal and contemporaneous aggregation of random-coefficient AR(1) processes with infinite variance
Authors: Pilipauskaitė Vytautė , Skorniakov Viktor , Surgailis Donatas 
Published: April 2020

AbstractWe discuss the joint temporal and contemporaneous aggregation of N independent copies of random-coefficient AR(1) processes driven by independent and identically distributed innovations in the domain of normal attraction of an
$\alpha$
-stable distribution,
$0< \alpha \le 2$
, as both N and the time scale n tend to infinity, possibly at different rates. Assuming that the tail distribution function of the random autoregressive coefficient regularly varies at the unit root with exponent
$\beta > 0$
, we show that, for
$\beta < \max (\alpha, 1)$
, the joint aggregate displays a variety of stable and non-stable limit behaviors with stability index depending on
$\alpha$
,
$\beta$
and the mutual increase rate of N and n. The paper extends the results of Pilipauskaitė and Surgailis (2014) from
$\alpha =2$
to
$0 < \alpha < 2$
.
On the multi-state signatures of ordered system lifetimes
Authors: Yi He , Balakrishnan Narayanaswamy , Cui Lirong 
Published: April 2020

AbstractIn this paper, the signature of a multi-state coherent system with binary-state components is discussed, and then it is extended to the case of ordered system lifetimes arising from a life-test on coherent multi-state systems with the same multi-state system signature. Some properties of the multi-state system signature and the ordered multi-state system signature are also studied. The results established here are finally explained through some illustrative examples.
Two-micron all-fiberized passively mode-locked fiber lasers with high-energy nanosecond pulse
Authors: Wang Meng , Huang Yijian , Song Zongpeng , Wei Jincheng , Pei Jihong , Ruan Shuangchen 
Published: April 2020

We report on mode-locked thulium-doped fiber lasers with high-energy nanosecond pulses, relying on the transmission in a semiconductor saturable absorber (SESA) and a carbon nanotube (CNTs-PVA) film separately. A section of an SMF–MMF–SMF structure multimode interferometer with a transmission peak wavelength of ∼2003 nm was used as a wavelength selector to fix the laser wavelength. When the SESA acted as a saturable absorber (SA), the mode-locked fiber laser had a maximum output power of ∼461 mW with a pulse energy of ∼0.14 μJ and a pulse duration of ∼9.14 ns. In a CNT-film-based mode-locked fiber laser, stable mode-locked pulses with the maximum output power of ∼46 mW, pulse energy of ∼26.8 nJ and pulse duration of ∼9.3 ns were obtained. To the best of our knowledge, our experiments demonstrated the first 2 μm region ‘real’ SA-based dissipative soliton resonance with the highest mode-locked pulse energy from a ‘real’ SA-based all-fiberized resonator.
VARIETIES OF GREEK: DISORDER AND CONTINUITY
Authors: Colvin Stephen 
Published: April 2020

Social magic always manages to produce discontinuity out of continuity.Social dialect, which can be defined negatively as dialect associated with variables other than geographic region, was hardly recognized as a linguistic category until the twentieth century. Although it has been recognized since antiquity that groups at the bottom of the socio-economic ladder speak differently from the elite, non-elite idioms did not merit serious investigation since they were regarded merely as corrupt or decadent approximations to the prestige variety. There is evidence that the Greeks also recognized gender as a variable in linguistic production. Age occasionally figures in discourse about language, but the association is vaguer since it was tangled up with the idea that earlier generations spoke a better or more authentic form of Greek.
Examining family language policy through realist social theory
Authors: Mirvahedi Seyed Hadi 
Published: April 2020

ABSTRACTIn this article, I argue that one social theory that could help us better understand the interaction between social structure and human agency in the context of family language policy (FLP) research is realist social theory. FLP studies in multilingual contexts have shown that home often becomes a site where dominant societal ideologies and discourses of structuring nature compete with individual views and agency, ultimately informing language behavior. Realist social theory advocates the analytical separation of structure and agency and attributes causal powers to both social structures and individual agency. This conceptualization of structure and agency prevents us from falling into structural determinism or individual voluntarism. Through examining the linguistic ideologies and practices of thirteen mothers of young children in Tabriz, Iran, I illustrate how family language policy emerges in interaction with and response to structural powers. (Family language policy, realist social theory, Iranian Azerbaijanis, agency, social structures, language maintenance)
An Early Roman Fort at Thirkleby, North Yorkshire
Authors: Millett Martin , Brickstock Richard 
Published: April 2020

ABSTRACTThis paper reports the discovery through aerial photography of a Roman fort at Thirkleby, near Thirsk in North Yorkshire. It appears to have two structural phases, and surface finds indicate that it dates from the Flavian period. The significance of its location on the intersection of routes north–south along the edge of the Vale of York and east–west connecting Malton and Aldborough is discussed in the context of Roman annexation of the North.
Maternal profile according to Mediterranean diet adherence and small for gestational age and preterm newborn outcomes
Authors: Peraita-Costa Isabel , Llopis-González Agustín , Perales-Marín Alfredo , Diago Vicente , Soriano Jose Miguel , Llopis-Morales Agustín , Morales-Suárez-Varela María 
Published: April 2020

AbstractObjective:The objective was to evaluate maternal Mediterranean diet (MD) pattern adherence during pregnancy and its association with small for gestational age (SGA) and preterm birth. A secondary objective of the current study was to describe the sociodemographic, lifestyle and obstetric profile of the mothers studied as well as the most relevant paternal and newborn characteristics.Design:The current study is a two-phase retrospective population-based study of maternal dietary habits during pregnancy and their effect on newborn size and prematurity. The descriptive first phase examined maternal dietary habits during pregnancy along with the maternal sociodemographic, lifestyle and obstetric profile in a cross-sectional period study. In the second phase, newborn outcomes were evaluated in a nested case–control study. Adherence to MD during pregnancy was measured with the Spanish version of Kidmed index.Setting:Obstetrics ward of the La Fe Hospital in Valencia.Participants:All mother–child pairs admitted after delivery during a 12-month period starting from January 2018 were assessed for eligibility. A total of 1118 provided complete outcome data after signing informed consent.Results:14·5 % met the criteria of poor adherence (PA); 34·8 %, medium adherence (MA); and 50·7 %, optimal adherence (OA). Medium adherence to MD was associated in the adjusted scenarios with a higher risk of giving birth to a preterm newborn. No association was found between MD adherence and SGA.Conclusions:Early intervention programmes geared towards pregnant women, where women were aided in reaching OA to MD, might reduce the risk of preterm newborn.
Citizen Approval of Monetary- vs Goods-For-Votes Exchanges
Authors: Cohen Mollie J. 
Published: April 2020

AbstractDoes citizen approval of vote buying depend on the type of benefit being offered? I answer this question using data from a survey experiment conducted on a nationally representative sample of Nicaraguans in 2017. Nicaraguans report significantly lower approval of money-for votes exchanges compared to goods-for-votes exchanges. Furthermore, reported rates of vote buying are lower in the money condition (4.8%) than in the goods-for-votes condition (7.8%), even though the posttreatment question assessing vote buying experience was identical across conditions. This study echoes other work suggesting the need for care in designing questions about vote buying, as slight changes in question wording that prime participants to think about goods versus monetary exchanges can affect both citizen approval of the behavior and the reported prevalence of vote buying.
A Statistical Analysis of the Fluctuations in the Upstream and Downstream Plasmas of 109 Strong‐Compression Interplanetary Shocks at 1 AU
Authors: Borovsky Joseph E. 
Published: April 2020

AbstractThe upstream and downstream plasmas of 109 strong‐compression forward interplanetary shocks are statistically analyzed using 3‐s measurements from the WIND spacecraft. The goal is a comparison of the fluctuation properties of downstream plasmas in comparison with the fluctuation properties of upstream plasmas in the inertial range of frequencies and the magnetic‐structure range of spatial scales. The shocks all have density compression rations of ~2 or more. When possible, each shock is categorized according to the type of solar wind plasma it propagates through: 15 shocks are in coronal‐hole‐origin plasma, 42 shocks are in streamer‐belt‐origin plasma, 36 shocks are in sector‐reversal‐region plasmas, and 11 shocks are in ejecta plasma. The statistical study examines magnetic field and velocity spectral indices, the Alfvénicity, the fluctuation amplitudes, Alfvén ratios, the degree of plasma inhomogeneity, and Taylor microscales, looking in particular at (1) fluctuation values downstream that are related to fluctuation values upstream and (2) systematic differences in fluctuation values associated with the type of plasma. It is argued that inhomogeneity of the downstream plasma can be caused by spatial variations in the shock normal angle θBn caused by field direction variations in the upstream magnetic structure. The importance of determining the type of plasma that the shock propagates through is established.
Evolution of Infragravity Waves Over a Shoal Under Nonbreaking Conditions
Authors: Li Shaowu , Liao Zhiling , Liu Ye , Zou Qingping 
Published: April 2020

AbstractThe present paper aims to clarify the mechanism of infragravity wave (IGW) energy amplification over nearshore shoals reported in recent studies. Wave transformation and energy transfer between short waves (SWs) and IGWs were investigated using SWASH model for nonbreaking random waves propagating over trapezoid shoals with different bottom slopes. It was found that the time lag of IGWs relative to SW groups is the major mechanism for energy transfer from SWs to IGWs and the amplification of IGW energy over all segments of the shoal. The time lag is generated on the front slope and enlarged on the plateau of the shoal, decreases on the rear slope with higher decreasing rates on milder slopes. Over the rear slope, the evolution of IGWs depends on the relative importance of deshoaling and nonlinear energy transfer. It was found that nonlinear energy transfer dominates over the rear slope gentler than 1/60, causing the IGW energy to increase over the first half of the deshoaling process and decrease over the second half whereas deshoaling dominates for steeper rear slope and the IGW energy decay over the whole slope. It is demonstrated numerically and theoretically that the shoals with gentler bottom slopes amplify the IGW energy more effectively by providing longer distance for nonlinear energy transfer to build up. The persistent nonlinear energy transfer on the plateau indicates the important role of wave spatial evolution history in the subsequent IGWs evolution. Strong free IGWs were detected on leeward of the shoal, possibly due to release of topography‐induced additional bound IGWs.
Four Theories of the Madden‐Julian Oscillation
Authors: Zhang C. , Adames Á. F. , Khouider B. , Wang B. , Yang D. 
Published: April 2020

AbstractStudies of the Madden‐Julian Oscillation (MJO) have progressed considerably during the past decades in observations, numerical modeling, and theoretical understanding. Many theoretical attempts have been made to identify the most essential processes responsible for the existence of the MJO. Criteria are proposed to separate a hypothesis from a theory (based on the first principles with quantitative and testable assumptions, able to predict quantitatively the fundamental scales and eastward propagation of the MJO). Four MJO theories are selected to be summarized and compared in this article: the skeleton theory, moisture‐mode theory, gravity‐wave theory, and trio‐interaction theory of the MJO. These four MJO theories are distinct from each other in their key assumptions, parameterized processes, and, particularly, selection mechanisms for the zonal spatial scale, time scale, and eastward propagation of the MJO. The comparison of the four theories and more recent development in MJO dynamical approaches lead to a realization that theoretical thinking of the MJO is diverse and understanding of MJO dynamics needs to be further advanced.
Changes in Physical Properties of Everglades Peat Soils Induced by Increased Salinity at the Laboratory Scale: Implications for Changes in Biogenic Gas Dynamics
Authors: Sirianni Matthew J. , Comas Xavier 
Published: April 2020

AbstractSaltwater intrusion due to sea level rise is a major concern for the Florida Everglades because it may induce shifts in ecosystem productivity and physical soil properties. However, the effects of saline water intrusion into the current carbon gas dynamics of the Everglades (particularly in terms of biogenic gas production and emissions, i.e., CH4 and CO2) are still uncertain. In this work, we present a laboratory‐based study to simulate how sea level rise may alter the physical properties (i.e., hydraulic conductivity) of peat soils from the Everglades and consequently affect the accumulation and release of biogenic gases within the peat matrix. Peat monoliths collected from the Everglades were subjected to progressive increases in salinity from a NaCl solution, and changes to the biogenic gas dynamics regime were simultaneously monitored using a combination of time‐lapse ground‐penetrating radar measurements, manometers, time‐lapse photography, and gas traps. Physical changes to the peat matrix at each salinity interval were assessed using constant head permeameter tests. Consistent with previous research, results show that a progressive increase in salinity (from fresh to saltwater) results in (1) a progressive increase in hydraulic conductivity and (2) a progressive decrease in gas content within the peat matrix (i.e., production) and gas releases. This work has implications for better understanding the potential effects of saltwater intrusion into freshwater peatland systems in the Everglades, particularly in terms of carbon gas dynamics.
Estimating the Occurrence of Geomagnetic Activity Using the Hilbert‐Huang Transform and Extreme Value Theory
Authors: Elvidge Sean 
Published: April 2020

AbstractIn this paper extreme value theory (EVT) has been used to estimate the return levels for geomagnetic activity based on the aa index. The aa index is the longest, continuously recorded, geomagnetic data set (from 1868 to present). This long, 150‐year data set is an ideal candidate for extreme value analysis. However, the data are not independent and identically distributed as required for EVT since they are impacted by the approximately 11‐year solar cycle. The Hilbert‐Huang transform has been used to identify the solar cycle component in the data, and the data have been split into solar maximum and minimum times. In these two regimes the generalized extreme value distribution has been fit to the data sets. These have also been combined for an estimate of the overall return times. The results suggest that the largest event in the database (March 1989) is a 1‐in‐25‐year event. However, considering separate solar maximum and minimum times has a large impact on the return times. During solar minimum conditions the return time of the March 1989 event is 130 years. This suggests that the occurrence of extreme space weather events is conditionally dependent on where in the solar cycle we are.
Diversity and dynamics of relevant nanoplanktonic diatoms in the Western English Channel
Authors: Arsenieff Laure , Le Gall Florence , Rigaut-Jalabert Fabienne , Mahé Frédéric , Sarno Diana , Gouhier Léna , Baudoux Anne-Claire , Simon Nathalie 
Published: April 2020

Abstract
In the ocean, Bacillariophyta are one of the most successful protistan groups. Due to their considerable biogeochemical implications, diatom diversity, development, and seasonality have been at the center of research, specifically large-sized species. In comparison, nanoplanktonic diatoms are mostly disregarded from routine monitoring and are often underrepresented in genetic reference databases. Here, we identified and investigated the temporal dynamics of relevant nanodiatoms occurring in the Western English Channel (SOMLIT-Astan station). Coupling in situ and laboratory approaches, we revealed that nano-species from the genera Minidiscus and Thalassiosira are key components of the phytoplankton community that thrive in these coastal waters, but they display different seasonal patterns. Some species formed recurrent blooms whilst others were persistent year round. These results raise questions about their regulation in the natural environment. Over a full seasonal cycle at the monitoring station, we succeeded in isolating viruses which infect these minute diatoms, suggesting that these mortality agents may contribute to their control. Overall, our study points out the importance of considering nanodiatom communities within time-series surveys to further understand their role and fate in marine systems.
Syntrophic splitting of central carbon metabolism in host cells bearing functionally different symbiotic bacteria
Authors: Ankrah Nana Y D , Wilkes Rebecca A , Zhang Freya Q , Zhu Dantong , Kaweesi Tadeo , Aristilde Ludmilla , Douglas Angela E 
Published: April 2020

Abstract
Insects feeding on the nutrient-poor diet of xylem plant sap generally bear two microbial symbionts that are localized to different organs (bacteriomes) and provide complementary sets of essential amino acids (EAAs). Here, we investigate the metabolic basis for the apparent paradox that xylem-feeding insects are under intense selection for metabolic efficiency but incur the cost of maintaining two symbionts for functions mediated by one symbiont in other associations. Using stable isotope analysis of central carbon metabolism and metabolic modeling, we provide evidence that the bacteriomes of the spittlebug Clastoptera proteus display high rates of aerobic glycolysis, with syntrophic splitting of glucose oxidation. Specifically, our data suggest that one bacteriome (containing the bacterium Sulcia, which synthesizes seven EAAs) predominantly processes glucose glycolytically, producing pyruvate and lactate, and the exported pyruvate and lactate is assimilated by the second bacteriome (containing the bacterium Zinderia, which synthesizes three energetically costly EAAs) and channeled through the TCA cycle for energy generation by oxidative phosphorylation. We, furthermore, calculate that this metabolic arrangement supports the high ATP demand in Zinderia bacteriomes for Zinderia-mediated synthesis of energy-intensive EAAs. We predict that metabolite cross-feeding among host cells may be widespread in animal–microbe symbioses utilizing low-nutrient diets.