bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of dimensional accuracy for micro-milled areal material measures with kinematic simulation
Authors: Klauer Katja , Eifler Matthias , Kirsch Benjamin , Böß Volker , Seewig Jörg , Aurich Jan C. 
Published: July 2021

AbstractThe calibration of areal surface topography measuring instruments is of high relevance to estimate the measurement uncertainty and to guarantee the traceability of the measurement results. Calibration structures for optical measuring instruments must be sufficiently small to determine the limits of the instruments.Besides other methods, micro-milling is a suitable process for manufacturing areal material measures. For the manufacturing by micro-milling with ball end mills, the tool radius (effective cutter radius) is the corresponding limiting factor: if the tool radius is too large to penetrate the concave profile details without removing the surrounding material, deviations from the target geometry will occur. These deviations can be detected and excluded before experimental manufacturing with the aid of a kinematic simulation.In this study, a kinematic simulation model for the prediction of the dimensional accuracy of micro-milled areal material measures is developed and validated. Subsequently, a radius study is conducted to determine how the tool radius r of the tool influences the dimensional accuracy of an areal crossed sinusoidal (ACS) geometry according to ISO 25178-70 [1] with a defined amplitude d and period length p. The resulting theoretical surface texture parameters are evaluated and compared to the target values. It was shown that the surface texture parameters deviate from the nominal values depending on the effective cutter radius used. Based on the results of the study, it can be determined with which effective tool radius the measurands Sa and Sq of the material measures are best met. The ideal effective radius for the application considered is between 50 and 75 μm.
Operational complexity and right linear grammars
Authors: Dassow Jürgen 
Published: July 2021

AbstractFor a regular language L, let $${{\,\mathrm{Var}\,}}(L)$$

Var

(
L
)

be the minimal number of nonterminals necessary to generate L by right linear grammars. Moreover, for natural numbers $$k_1,k_2,\ldots ,k_n$$

k
1

,

k
2

,
…
,

k
n

and an n-ary regularity preserving operation f, let $$g_f^{{{\,\mathrm{Var}\,}}}(k_1,k_2,\ldots ,k_n)$$

g
f

Var

(

k
1

,

k
2

,
…
,

k
n

)

be the set of all numbers k such that there are regular languages $$L_1,L_2,\ldots , L_n$$

L
1

,

L
2

,
…
,

L
n

such that $${{\,\mathrm{Var}\,}}(L_i)=k_i$$

Var

(

L
i

)

=

k
i

for $$1\le i\le n$$

1
≤
i
≤
n

and $${{\,\mathrm{Var}\,}}(f(L_1,L_2,\ldots , L_n))=k$$

Var

(
f

(

L
1

,

L
2

,
…
,

L
n

)

)
=
k

. We completely determine the sets $$g_f^{{{\,\mathrm{Var}\,}}}$$

g
f

Var

for the operations reversal, Kleene-closures $$+$$
+
and $$*$$

∗

, and union; and we give partial results for product and intersection.
Heat capacity, entropy, configurational entropy, and viscosity of magnesium silicate glasses and liquids
Authors: Majzlan Juraj , Tangeman Jean A. , Dachs Edgar 
Published: July 2021

AbstractIn this work, five Mg-silicate glasses with compositions between MgSiO$$_3$$

3

and Mg$$_2$$

2

SiO$$_4$$

4

were synthesized by aerodynamic levitation combined with laser melting. Low-temperature heat capacity ($$C_p$$

C
p

) was measured (by relaxation calorimetry in the range 2–310 K) for all of them, with the resulting vibrational entropies at T = 298.15 K: sample MG50 with composition Mg$$_{0.996}$$

0.996

SiO$$_{2.996}$$

2.996

and entropy 72.88 J mol$$^{-1}$$

-
1

K$$^{-1}$$

-
1

; MG54 Mg$$_{1.174}$$

1.174

SiO$$_{3.174}$$

3.174

78.54; MG58 Mg$$_{1.364}$$

1.364

SiO$$_{3.364}$$

3.364

85.05; MG62 Mg$$_{1.611}$$

1.611

SiO$$_{3.611}$$

3.611

91.40; and MG67 Mg$$_{1.907}$$

1.907

SiO$$_{3.907}$$

3.907

102.75. Heat capacity of the glasses is higher than that of the corresponding crystal mixtures below 200 K but plunges below the C$$_{p,\mathrm{crystal}}$$

p
,
crystal

at higher temperatures. High-temperature $$C_p$$

C
p

was measured (by differential scanning calorimetry in the range 300–970 K) for MG50 and MG67 up to $$\approx $$
≈
1000 K. Using our $$C_p$$

C
p

data, selected data for entropies of fusion, $$C_p$$

C
p

of crystals, and fictive temperatures, the configurational entropy ($$S_\mathrm{conf}$$

S
conf

) at glass transition temperature ($$T_\mathrm{g}$$

T
g

) were calculated. For the near-forsterite glass MG67, the $$S_\mathrm{conf}$$

S
conf

is 1.9 J mol$$^{-1}$$

-
1

K$$^{-1}$$

-
1

at $$T_\mathrm{g}$$

T
g

= 1040 K. As this small value is a difference of several large numbers, its uncertainty is relatively high; we consider a conservative estimate of 15 J mol$$^{-1}$$

-
1

K$$^{-1}$$

-
1

. Using the expression $$\log \eta = A + B/[T S_\mathrm{conf}(T)]$$

log
η
=
A
+
B
/
[
T

S
conf

(
T
)

]

, the available experimental viscosities ($$\eta $$
η
) and the temperature-dependent configurational entropy from our work, we refined the parameters $$A = -2.34$$

A
=
-
2.34

and $$B = 76,500$$

B
=
76
,
500

for this equation, with $$S_\mathrm{conf} (T) = 1.90+(83.7 \ln (T/1040))$$

S
conf

(
T
)

=
1.90
+

(
83.7
ln

(
T
/
1040
)

)

. The configurational entropy for the enstatitic MG50 glass is 16.8 J mol$$^{-1}$$

-
1

K$$^{-1}$$

-
1

at $$T_\mathrm{g}$$

T
g

= 1063 K. The presented data can be combined with enthalpies of formation and thermophysical properties of Mg-silicate glasses for models that could elucidate geological and geophysical observations in the crust and mantle of the Earth.
Management of cell death in parasitic infections
Authors: Bosurgi Lidia , Rothlin Carla V. 
Published: July 2021

AbstractFor a long time, host cell death during parasitic infection has been considered a reflection of tissue damage, and often associated with disease pathogenesis. However, during their evolution, protozoan and helminth parasites have developed strategies to interfere with cell death so as to spread and survive in the infected host, thereby ascribing a more intriguing role to infection-associated cell death. In this review, we examine the mechanisms used by intracellular and extracellular parasites to respectively inhibit or trigger programmed cell death. We further dissect the role of the prototypical “eat-me signal” phosphatidylserine (PtdSer) which, by being exposed on the cell surface of damaged host cells as well as on some viable parasites via a process of apoptotic mimicry, leads to their recognition and up-take by the neighboring phagocytes. Although barely dissected so far, the engagement of different PtdSer receptors on macrophages, by shaping the host immune response, affects the overall infection outcome in models of both protozoan and helminth infections. In this scenario, further understanding of the molecular and cellular regulation of the PtdSer exposing cell-macrophage interaction might allow the identification of new therapeutic targets for the management of parasitic infection.
Experimental evaluation of methodologies for single transient cavitation bubble generation in liquids
Authors: Podbevšek Darjan , Lokar Žiga , Podobnikar Jure , Petkovšek Rok , Dular Matevž 
Published: July 2021

AbstractSingle bubble dynamics are of fundamental importance for understanding the underlying mechanisms in liquid–vapor transition phenomenon known as cavitation. In the past years, numerous studies were published and results were extrapolated from one technique to another and further on to “real-world” cavitation. In the present paper, we highlight the issues of using various experimental approaches to study the cavitation bubble phenomenon and its effects. We scrutinize the transients bubble generation mechanisms behind tension-based and energy deposition-based techniques and overview the physics behind the bubble production. Four vapor bubble generation methods, which are most commonly used in single bubble research, are directly compared in this study: the pulsed laser technique, a high- and low-voltage spark discharge and the tube arrest method. Important modifications to the experimental techniques are implemented, demonstrating improvement of the bubble production range, control and repeatability. Results are compared to other similar techniques from the literature, and an extensive report on the topic is given in the scope of this work. Simple-to-implement techniques are presented and categorized herein, in order to help with future experimental design. Repeatability and sphericity of the produced bubbles are examined, as well as a comprehensive overview on the subject, listing the bubble production range and highlighting the attributes and limitation for the transient cavitation bubble techniques.Graphic abstract
Diastolic dysfunction in individuals with and without heart failure with preserved ejection fraction
Authors: Wenzel Jan-Per , Kellen Ramona Bei der , Magnussen Christina , Blankenberg Stefan , Schrage Benedikt , Schnabel Renate , Nikorowitsch Julius 
Published: July 2021

Abstract
Aim
Left ventricular diastolic dysfunction (DD), a common finding in the general population, is considered to be associated with heart failure with preserved ejection faction (HFpEF). Here we evaluate the prevalence and correlates of DD in subjects with and without HFpEF in a middle-aged sample of the general population.

Methods and results
From the first 10,000 participants of the population-based Hamburg City Health Study (HCHS), 5913 subjects (mean age 64.4 ± 8.3 years, 51.3% females), qualified for the current analysis. Diastolic dysfunction (DD) was identified in 753 (12.7%) participants. Of those, 11.2% showed DD without HFpEF (ALVDD) while 1.3% suffered from DD with HFpEF (DDwHFpEF). In multivariable regression analysis adjusted for major cardiovascular risk factors, ALVDD was associated with arterial hypertension (OR 2.0, p < 0.001) and HbA1c (OR 1.2, p = 0.007). Associations of both ALVDD and DDwHFpEF were: age (OR 1.7, p < 0.001; OR 2.7, p < 0.001), BMI (OR 1.2, p < 0.001; OR 1.6, p = 0.001), and left ventricular mass index (LVMI). In contrast, female sex (OR 2.5, p = 0.006), atrial fibrillation (OR 2.6, p = 0.024), CAD (OR 7.2, p < 0.001) COPD (OR 3.9, p < 0.001), and QRS duration (OR 1.4, p = 0.005) were strongly associated with DDwHFpEF but not with ALVDD.

Conclusion
The prevalence of DD in a sample from the first 10,000 participants of the population-based HCHS was 12.7% of whom 1.3% suffered from HFpEF. DD with and without HFpEF showed significant associations with different major cardiovascular risk factors and comorbidities warranting further research for their possible role in the formation of both ALVDD and DDwHFpEF.
Analysis of tribological behaviour of titanium nitride-coated stainless steel with the use of wavelet-based methods
Authors: Łępicka Magdalena , Górski Grzegorz , Grądzka-Dahlke Małgorzata , Litak Grzegorz , Ambrożkiewicz Bartłomiej 
Published: July 2021

AbstractTribological behaviour is characterized by the strong nonlinear effects in its response, which are hardly identified with standard signal processing methods. One of the challenges in the analysis of wear phenomena is identification of its propagation and potential quantification. In our study, we propose application of wavelet-based methods, i.e. continuous wavelet transform and scale index for analysis of the dynamical response in the tribological pair. The analysed parameter will be the coefficient of friction, which is slightly changing with wear of the tribological pair. The performed analysis shows the variable response of the system in each considered state. Moreover, results obtained with wavelets are useful for its determination. The proposed methods can be particularly useful in the transportation applications, where the quantification of the friction force between the sliding counterparts is a crucial parameter, responsible for the power losses. Early and efficient identification of wear allows to predict damage and avoid undesirable downtime or time-consuming exchange of a worn out part.
Soil Denitrification, the Missing Piece in the Puzzle of Nitrogen Budget in Lowland Agricultural Basins
Authors: Soana Elisa , Vincenzi Fabio , Colombani Nicolò , Mastrocicco Micòl , Fano Elisa Anna , Castaldelli Giuseppe 
Published: July 2021

AbstractDenitrification is a key process buffering the environmental impacts of agricultural nitrate loads but, at present, remains the least understood and poorly quantified sink in nitrogen budgets at the watershed scale. The present work deals with a comprehensive and detailed analysis of nitrogen sources and sinks in the Burana–Volano–Navigabile basin, the southernmost portion of the Po River valley (Northern Italy), an intensively cultivated (> 85% of basin surface) low-lying landscape. Agricultural census data, extensive monitoring of surface–groundwater interactions, and laboratory experiments targeting N fluxes and pools were combined to provide reliable estimates of soil denitrification at the basin scale. In the agricultural soils of the basin, nitrogen inputs exceeded outputs by nearly 40% (~ 80 kg N ha−1year−1), but this condition of potential N excess did not translate into widespread nitrate pollution. The general scarcity of inorganic nitrogen species in groundwater and soils indicated limited leakage and storage. Multiple pieces of evidence supported that soil denitrification was the process that needed to be introduced in the budget to explain the fate of the missing nitrogen. Denitrification was likely boosted in the soils of the studied basin, prone to waterlogged conditions and consequently oxygen-limited, owing to peculiar features such as fine texture, low hydraulic conductivity, and shallow water table. The present study highlighted the substantial contribution of soil denitrification to balancing nitrogen inputs and outputs in agricultural lowland basins, a paramount ecosystem function preventing eutrophication phenomena.
Sex-specific growth of nestlings of the Whiskered Tern Chlidonias hybrida, a species with sexual size dimorphism and female brood desertion
Authors: Banach Agata , Neubauer Grzegorz , Flis Adam , Ledwoń Mateusz 
Published: July 2021

AbstractThe growth of a nestling during the first few weeks after hatching is crucial for its further life and is sensitive to the conditions experienced during this period. Among species exhibiting Sexual Size Dimorphism (SSD), one of the most important factors influencing growth parameters is the sex of the hatchlings. In this study, we tested whether sex and other factors (hatching date, egg volume, brood size and sex ratio in the brood) were related to sex on growth parameters in Whiskered Tern(Chlidonias hybrida) chicks. In this species, males are 3%–10% larger than females when adult. At hatching, only the total head length was greater in males than females, but values close to fledging were greater for most of the measured parameters (3%—tarsus, 4%—total head length, 13%—body mass). Moreover, the maximum body mass growth rate was higher in males but females entered the rapid growth phase somewhat earlier and achieved the final total head length sooner. Nestling growth was also significantly correlated with brood size and hatching date, though mostly negatively (e.g. lower tarsus and total head length asymptote, lower maximum growth rate and growth rate constant of total head length in bigger and later clutches). The occurrence of SSD during the nestling period and higher maximum growth rate of body mass in males indicates that the costs of raising sons may be higher than of raising daughters. However, we did not find evidence of either sex-biased nestling mortality or skewed sex ratio.
Immundefiziente Labortiere im System des Tierschutzrechts
Authors: Iglauer Franz , Martínez José , Schenkel Johannes 
Published: July 2021

ZusammenfassungZucht und Haltung immundefizienter Labortiere wurden bislang nicht als Tierversuch gewertet, soweit
die Tiere mit an Sicherheit grenzender Wahrscheinlichkeit nicht aufgrund des Immundefekts leiden müssen.
Das aufgrund des Wahrscheinlichkeitsmaßstabs hinzunehmende Restrisiko, insbesondere durch äußere
Ereignisse hat sich in der versuchstierkundlichen Praxis nicht realisiert. Trotzdem wertet die EU-Kommission
nunmehr Zucht und Haltung immundefizienter Labortiere grundsätzlich als Tierversuch – mit erheblichem
administrativem Mehraufwand in den mit Tieren forschenden Wissenschaften und der behördlichen Praxis.
Im Folgenden wird aus versuchstierkundlicher und rechtlicher Perspektive festgestellt, dass diese Neubewertung
der Kommission weder sachgemäß noch verhältnismäßig ist.
International cooperation on financial market regulation
Authors: Abendschein Michael , Gölz Harry 
Published: July 2021

AbstractAt the latest the global financial crisis has raised the awareness of the need for a globally coordinated financial market regulation. Even though the necessity to cooperate is widely acknowledged, cooperation is often limited in practice. This article characterizes the formation of self-enforcing international financial regulation agreements. Our analysis allows to evaluate the desirability and feasibility of cooperative solutions and explains the challenges associated with the process of cooperation. We model the cooperation of national financial regulators in a game-theoretical framework that considers financial stability to be an impure public good. Joint national supervisory effort is supposed to increase aggregate welfare in terms of a more stable financial system both on a global and on a local level by simultaneously generating incentives to free-ride. Our analysis in general indicates the difficulty of reaching a fully cooperative solution. In our basic version of the model we show that partial cooperation of two or three countries is stable and improves the welfare of all countries relative to the non-cooperative Nash equilibrium. Further analyses highlight the role of additional club benefits. When signatory countries of a coalition gain benefits over and above the joint welfare maximization, stable coalitions of any size become feasible.
In-plane lateral cyclic behaviour of lime-mortar and clay-brick masonry walls in dry and wet conditions
Authors: Elghazouli A. Y. , Bompa D. V. , Mourad S. A. , Elyamani A. 
Published: July 2021

AbstractThis paper presents an experimental investigation into the structural and material response of ambient-dry and wet clay-brick/lime-mortar masonry elements. In addition to cyclic tests on four large-scale masonry walls subjected to lateral in-plane displacement and co-existing compressive gravity load, the study also includes complementary tests on square masonry panels under diagonal compression and cylindrical masonry cores in compression. After describing the specimen details, wetting method and testing arrangements, the main results and observations are provided and discussed. The results obtained from full-field digital image correlation measurements enable a detailed assessment of the material shear-compression strength envelope, and permit a direct comparison with the strength characteristics of structural walls. The full load-deformation behaviour of the large-scale walls is also evaluated, including their ductility and failure modes, and compared with the predictions of available assessment models. It is shown that moisture has a notable effect on the main material properties, including the shear and compression strengths, brick–mortar interaction parameters, and the elastic and shear moduli. The extent of the moisture effects is a function of the governing behaviour and material characteristics as well as the interaction between shear and precompression stresses, and can lead to a loss of more than a third of the stiffness and strength. For the large scale wall specimens subjected to lateral loading and co-existing compression, the wet-to-dry reduction was found to be up to 20% and 11% in terms of stiffness and lateral strength, respectively, whilst the ductility ratio diminished by up to 12%. Overall, provided that the key moisture-dependent material properties are appropriately evaluated, it is shown that analytical assessment methods can be reliably adapted for predicting the response, in terms of the lateral stiffness, strength and overall load-deformation, for both dry and wet masonry walls.
Comparative assessment of finite element macro-modelling approaches for seismic analysis of non-engineered masonry constructions
Authors: Ravichandran Nagavinothini , Losanno Daniele , Parisi Fulvio 
Published: July 2021

AbstractAll around the world, non-engineered masonry constructions (NECs) typically have high vulnerability to seismic ground motion, resulting in heavy damage and severe casualties after earthquakes. Even though a number of computational strategies have been developed for seismic analysis of unreinforced masonry structures, a few studies have focussed on NECs located in developing countries. In this paper, different modelling options for finite element analysis of non-engineered masonry buildings are investigated. The goal of the study was to identify the modelling option with the best trade-off between computational burden and accuracy of results, in view of seismic risk assessment of NECs at regional scale. Based on the experimental behaviour of a single-storey structure representative of Indian non-engineered masonry buildings, the output of seismic response analysis of refined 3D models in ANSYS was compared to that of a simplified model based on 2D, nonlinear, layered shell elements in SAP2000. The numerical-experimental comparison was carried out under incremental static lateral loading, whereas nonlinear time history analysis was performed to investigate the dynamic performance of the case-study structure. Analysis results show that the simplified model can be a computationally efficient modelling option for both nonlinear static and dynamic analyses, particularly in case of force-based approaches for design and assessment of base isolation systems aimed at the large-scale seismic vulnerability mitigation of NECs.
How history of mathematics can help to face a crisis situation: the case of the polemic between Bernoulli and d’Alembert about the smallpox epidemic
Authors: Gosztonyi Katalin 
Published: July 2021

AbstractIn this article, I present the eighteenth century’s polemic of Bernoulli and d’Alembert concerning the smallpox epidemic and a prevention method called inoculation. Through an analysis of the polemic and the related resources, I show that this historical debate has various interests for mathematics education; and more specifically it can help teachers to confront dilemmas emerging with the COVID-19 pandemic (for example if a teacher should talk about it in class or not, how to help students to interpret the statistical data and the mathematical models connected to the pandemic and more generally, how to deal with the confusions and concerns emerging in connection to the pandemic). I describe the documents related to the historical polemic as transitional objects, having a potential to reveal the teachers’ own professional or personal experiences, reflections and questions, and to stimulate dialogue with them on these issues. I illustrate this proposition by the presentation of an online reading seminar realized with a French group of teachers in April 2020.