bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spectroscopic and Chemical Properties of Ionic Liquids: Computational Study
Authors: Kim Hyung J. 
Published: May 2023

AbstractA brief account is given of highlights of our computational efforts – often in collaboration with experimental groups – to understand spectroscopic and chemical properties of ionic liquids (ILs). Molecular dynamics, including their inhomogeneous character, responsible for key spectral features observed in dielectric absorption, infra‐red (IR) and fluorescence correlation spectroscopy (FCS) measurements are elucidated. Mechanisms of chemical processes involving imidazolium‐based ILs are illustrated for CO2 capture and related reactions, transesterification of cellulose, and Au nanocluster‐catalyzed Suzuki cross‐coupling reaction with attention paid to differing roles of IL ions. A comparison with experiments is also made.
Visualizable intracardiac flow pattern in fetuses with congenital heart defect: pilot study of blood speckle‐tracking echocardiography
Authors: Xu R. , Hou M. , Zhou D. , Liu Y. , Xie L. , Zeng S. 
Published: May 2023

ABSTRACTObjectivesBlood‐flow pattern is an essential factor in cardiovascular development. Recently, blood speckle‐tracking echocardiography (BST) based on high‐frame‐rate ultrasound has emerged as a promising technique for the assessment of blood‐flow patterns and properties. The objectives of this study were to determine the feasibility of BST in the fetus and to assess intracardiac blood‐flow patterns of fetuses with a congenital heart defect (CHD) using this technique.MethodsThis was a prospective study consisting of 35 normal fetuses, 35 fetuses with left‐sided obstructive lesion (LSOL) and 35 fetuses with right‐sided obstructive lesion (RSOL). BST images of fetal intracardiac regions of interest (ROIs), including the left ventricle (LV), right ventricle (RV), ascending aorta (AAo), aortic arch (AA), descending aorta (DAo) and pulmonary artery (PA), were obtained and analyzed. The feasibility of BST was assessed, and blood‐flow pattern and number of vortices in the ROIs were recorded.ResultsThe median gestational age of the fetuses was 24.7 weeks (range, 19.6–34.3 weeks). BST was feasible in 81.6% of cases, and the cut‐off value of depth for an adequate BST image was ≤ 7.9 cm. There were no differences in the presence of vortex/turbulent blood flow in the LV or RV among the three groups. Vortex/turbulent blood flow in the AAo was detected in 0% (0/35), 14.3% (5/35) and 57.1% (20/35) of cases in the control, LSOL and RSOL groups, respectively. The respective values were 5.7% (2/35), 14.3% (5/35) and 51.4% (18/35) for the AA; 0% (0/35), 48.6% (17/35) and 0% (0/35) for the DAo; and 0% (0/35), 40.0% (14/35) and 51.4% (18/35) for the PA. With the exception of the DAo in the RSOL group, vortex/turbulent flow in the great artery ROIs was significantly more common in the LSOL and RSOL groups than in controls (P < 0.01). In the LSOL group, the number of vortices in the AAo, AA, DAo and PA was significantly greater compared with that in controls (P < 0.01). In the RSOL group, the number of vortices in the LV, AAo, AA and PA was significantly greater compared with that in controls (P < 0.01).ConclusionsFetuses with CHD were more likely to exhibit vortex/turbulent blood flow and increased number of vortices in the great arteries compared with healthy controls. Further research is needed to determine the biomechanical effect of blood‐flow patterns, especially vortex flow, on fetal cardiovascular structure and function. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.
On calibrated inverse probability weighting and generalized boosting propensity score models for mean estimation with incomplete survey data
Authors: Kang Joseph , Morris Darcy Steeg , Joyce Patrick , Dompreh Isaac 
Published: May 2023

AbstractIncomplete data, whether realized from nonresponse in survey data or counterfactual outcomes in observational studies, may lead to biased estimation of study variables. Nonresponse and selection bias may be mitigated with techniques that weight the incomplete data to match characteristics of the partially unobserved complete data. Inverse probability weighting is a widely used method in causal inference that relies on a propensity model to construct adjusted weights; whereas calibration is a common method used by survey statisticians to use constrained optimization to construct adjusted weights. This article reviews inverse probability weighting and entropy balancing calibration by distinguishing them in the statistical sense of variable balancing, extending propensity score construction to include generalized boosting models, and demonstrating the use of inverse probability weighting and calibration separately and together through a widely cited simulation study evaluation.This article is categorized under:
Statistical and Graphical Methods of Data Analysis > Sampling
Data: Types and Structure > Categorical Data
Statistical Learning and Exploratory Methods of the Data Sciences > Modeling Methods
A comparative meta‐analysis of gains in efficiency in Pb‐ and Sn‐based perovskite solar cells over the last decade
Authors: Huang Chengou , Gajewiak Emil , Wright Aidan , Rodriguez‐Kazeem William , Heift Dominikus , Bear Joseph C. 
Published: May 2023

AbstractPerovskite solar cells have seen rapid development over the last decade due to their potential to surpass current market‐leading solar cell technologies. Power conversion efficiency values of perovskite solar cells have reached more than 25 %, making them comparable to their market‐leading silicon‐based counterparts with comparatively few years of development. Whilst large‐scale trials are ongoing, the long‐term stability of perovskite materials remains a significant challenge in their deployment. The first successful perovskite‐based solar cells were lead‐based (Pb‐based). Environmental concerns surrounding Pb‐based perovskites are a significant impediment to their application in industry leading to a substantial increase in research into alternatives that are more environmentally sound.The meta‐analysis study presented in this paper intends to harvest efficiency and synthetic method data from the literature to chart the progress of efficiency over the last decade of BOTH Pb‐ and Sn‐based perovskite solar cells. We then use these data to test the hypothesis: “Did the advancements in the development of earlier Pb‐based perovskite solar cells mean the efficiency of Sn‐based alternatives developed at a faster rate?”The meta‐analysis found that materials engineering, i. e., identifying the suitable materials for perovskite, electron and transport layers and the solution and fabrication process contributed significantly to the rapid annual efficiency growth rates in Pb‐based perovskite solar cells (more than 25 %) from 2011 to 2014. More steady annual efficiency growth rates (2 to 7 %) from 2014 to 2021 are attributed to more advanced compositional engineering, such as optimizing bandgap and addressing stability problems, solution and additive engineering with regard thermal annealing, ageing, doping, improving crystallinity and passivating defects. Ultimately, this report states the challenges Sn‐based perovskite materials face and improvements that will have to be made to become successful on a commercial scale. One of our key findings is the increase in efficiency from 5 % in 2014 to 13 % in 2020 of Sn‐based perovskites making them one of the main contenders to replace Pb‐based perovskites. However, significant challenges remain, including reducing their instability and increasing their efficiencies beyond 20 % to make them competitive against their Pb‐based counterparts.
Nutrients and Eutrophication
Authors: Devlin Michelle , Brodie Jon 
Published: May 2023

AbstractExcess nutrientsfrom fertiliser application, pollution discharge and water regulations outflow through rivers from lands to oceans, seriously impact coastal ecosystems. Terrestrial runoff of waters polluted with nutrients (primarilynitrogen[N] andphosphorus[P] compounds) from point source/s, such as sewage treatment plant (STP) discharges, and diffuse sourcesvia river discharges, such as fertiliser losses, are having devastating adverse effects in coastal and marine ecosystems globally (Carpenter et al., Ecol Appl 8:559–568, 1998; Halpern et al., Science 319:948–952, 2008; Crain et al., Ecol Lett 11:1304–1315, 2008; Smith and Schindler, Trends Ecol Evol 24:201–207, 2009). The nutrients can be dissolved such as dissolved nitrate and Phosphate typically discharged from STPs or agricultural runoff or in a particulate form, often associated with soil erosion.
Metals and Metalloids
Authors: Reichelt-Brushett Amanda , Batley Graeme 
Published: May 2023

AbstractThis chapter introduces you tometalsandmetalloidsthat are a concern to the health of marine ecosystems. It provides a general chemical understanding of important metals and metalloids, their sources, behaviour, impacts and management. Metals, metalloids and non-metals all make up the periodic table (Appendix II) and are classified into these categories according to their properties. Metals are good conductors of heat and electricity and are malleable and ductile, making them very useful to humans and therefore economically valuable. Metalloids sit on the periodic table in a jagged line at the division between metals and non-metals and have intermediate properties.
Overview of Concrete Deterioration Due to Sulphate Attack and Comparison of Its Requirements in International Codes
Authors: Al-Haddad Diala Basim , Jokhio Gul Ahmed , Tair Abid Abu 
Published: May 2023

AbstractAny material or geometric property change that has an impact on structural performance is known as structural deterioration. Although this phenomenon is gradual, if it is not evaluated and fixed in a timely manner, it will have a severe impact on the structure and, in some historical occasions, may result in collapse. Deterioration has a variety of causes and mechanisms. Some are regarded as external, such as the environment, which is critical in areas with tough climate conditions, as the Arab Gulf, where temperatures and humidity are high, another factor is the low quality of the materials and poor craftsmanship. Depending on the type of materials used in the structure and the environment in which it is created, several precaution approaches for structural degradation may be adapted.Sulphate attack is one of the most widespread deteriorating mechanisms; this type of chemical damage can result in cracks, spalling, and disintegration of the structure, diminishing its strength. This paper presents a thorough investigation of this degrading agent, including its causes, effects, international code provisions, as well as recent studies on the subject with a focus on the Arab Gulf Countries.The outcomes of this study demonstrated that this phenomenon, with its various mechanisms, has a negative impact on structures. Despite the distribution of sulphates in the Gulf, the existence of chloride and the precautionary measures taken successfully limited their impact on structures.
Scale setting and the light baryon spectrum in Nf = 2 + 1 QCD with Wilson fermions
Authors:   The RQCD collaboration, Bali Gunnar S. , Collins Sara , Georg Peter , Jenkins Daniel , Korcyl Piotr , Schäfer Andreas , Scholz Enno E. , Simeth Jakob , Söldner Wolfgang , Weishäupl Simon 
Published: May 2023

AbstractWe determine the light baryon spectrum on ensembles generated by the Coordinated Lattice Simulations (CLS) effort, employingNf= 2 + 1 flavours of non-perturbatively improved Wilson fermions. The hadron masses are interpolated and extrapolated within the quark mass plane, utilizing three distinct trajectories, two of which intersect close to the physical quark mass point and the third one approaching the SU(3) chiral limit. The results are extrapolated to the continuum limit, utilizing six different lattice spacings ranging froma≈ 0.10 fm down to below 0.04 fm. The light pion mass varies fromMπ≈ 429 MeV down to 127 MeV. In general, the spatial extent is kept larger than four times the inverse pion mass and larger than 2.3 fm, with additional small and large volume ensembles to investigate finite size effects. We determine the Wilson flow scales$$ \sqrt{t_{0,\textrm{ph}}}={0.1449}_{(9)}^{(7)}\textrm{fm} $$t0,ph=0.144997fm[1] and$$ {t}_0^{\ast}\approx {t}_{0,\textrm{ph}} $$t0∗≈t0,ph[2] from the octet cascade (Ξ baryon). Determining the light baryon spectrum in the continuum limit, we find the nucleon mass$$ {m}_N={941.7}_{(7.6)}^{(6.5)} $$mN=941.77.66.5MeV and the other stable baryon masses to agree with their experimental values within sub-percent level uncertainties. Moreover, we determine SU(3) and SU(2) chiral perturbation theory low energy constants, including the octet and the Ω baryon sigma termsσπN= 43.9(4.7) MeV,$$ {\sigma}_{\pi \Lambda}={28.2}_{(5.4)}^{(4.3)} $$σπΛ=28.25.44.3MeV,$$ {\sigma}_{\pi \Sigma}={25.9}_{(6.1)}^{(3.8)} $$σπΣ=25.96.13.8MeV,$$ {\sigma}_{\pi \Xi}={11.2}_{(6.4)}^{(4.5)} $$σπΞ=11.26.44.5and$$ {\sigma}_{\pi \Omega}={6.9}_{(4.3)}^{(5.3)} $$σπΩ=6.94.35.3MeV, as well as various parameters, renormalization factors and improvement coefficients that are relevant for simulations with our lattice action.
The Scale of Supersymmetry Breaking and the Dark Dimension
Authors: Anchordoqui Luis A. , Antoniadis Ignatios , Cribiori Niccolò , Lüst Dieter , Scalisi Marco 
Published: May 2023

Abstract
We argue for a relation between the supersymmetry breaking scale and the measured value of the dark energy density Λ. We derive it by combining two quantum gravity consistency swampland constraints, which tie the dark energy density Λ and the gravitino mass M3/2, respectively, to the mass scale of a light Kaluza-Klein tower and, therefore, to the UV cut-off of the effective theory. Whereas the constraint on Λ has recently led to the Dark Dimension scenario, with a prediction of a single mesoscopic extra dimension of the micron size, we use the constraint on M3/2 to infer the implications of such a scenario for the scale of supersymmetry breaking. We find that a natural scale for supersymmetry signatures is$$ M=\mathcal{O}\left({\Lambda}^{\frac{1}{8}}\right)=\mathcal{O}\left(\textrm{TeV}\right). $$
M
=
O

Λ

1
8

=
O

TeV

.
This mass scale is within reach of LHC and of the next generation of hadron colliders. Finally, we discuss possible string theory and effective supergravity realizations of the Dark Dimension scenario with broken supersymmetry.
Freedom near lightcone and ANEC saturation
Authors: Huang Kuo-Wei , Karlsson Robin , Parnachev Andrei , Valach Samuel 
Published: May 2023

Abstract
Averaged Null Energy Conditions (ANECs) hold in unitary quantum field theories. In conformal field theories, ANECs in states created by the application of the stress tensor to the vacuum lead to three constraints on the stress-tensor three-point couplings, depending on the choice of polarization. The same constraints follow from considering two-point functions of the stress tensor in a thermal state and focusing on the contribution of the stress tensor in the operator product expansion (OPE). One can observe this in holographic Gauss-Bonnet gravity, where ANEC saturation coincides with the appearance of superluminal signal propagation in thermal states. We show that, when this happens, the corresponding generalizations of ANECs for higher-spin multi-stress tensor operators with minimal twist are saturated as well and all contributions from such operators to the thermal two-point functions vanish in the lightcone limit. This leads to a special near-lightcone behavior of the thermal stress-tensor correlators — they take the vacuum form, independent of temperature.
Cyclic products of Szegö kernels and spin structure sums. Part I. Hyper-elliptic formulation
Authors: D’Hoker Eric , Hidding Martijn , Schlotterer Oliver 
Published: May 2023

Abstract
The summation over spin structures, which is required to implement the GSO projection in the RNS formulation of superstring theories, often presents a significant impediment to the explicit evaluation of superstring amplitudes. In this paper we discover that, for Riemann surfaces of genus two and even spin structures, a collection of novel identities leads to a dramatic simplification of the spin structure sum. Explicit formulas for an arbitrary number of vertex points are obtained in two steps. First, we show that the spin structure dependence of a cyclic product of Szegö kernels (i.e. Dirac propagators for worldsheet fermions) may be reduced to the spin structure dependence of the four-point function. Of particular importance are certain trilinear relations that we shall define and prove. In a second step, the known expressions for the genus-two even spin structure measure are used to perform the remaining spin structure sums. The dependence of the spin summand on the vertex points is reduced to simple building blocks that can already be identified from the two-point function. The hyper-elliptic formulation of genus-two Riemann surfaces is used to derive these results, and its SL(2, ℂ) covariance is employed to organize the calculations and the structure of the final formulas. The translation of these results into the language of Riemann ϑ-functions, and applications to the evaluation of higher-point string amplitudes, are relegated to subsequent companion papers.
SYK Model with global symmetries in the double scaling limit
Authors: Narayan Prithvi , Swathi T S 
Published: May 2023

Abstract
We discuss the double scaling limit of the SYK model with global symmetries. We develop the chord diagram techniques to compute the moments of the Hamiltonian and the two point function in the presence of arbitrary chemical potential. We also derive a transfer matrix acting on an auxiliary hilbert space which can capture the chord diagram contributions. We present explicit results for the case of classical group symmetries namely orthogonal, unitary and symplectic groups. We also find the partition functions at fixed charges.
Factors determining the distribution of Erica patches on the Sanetti Plateau, Bale Mountains, Ethiopia
Authors: Mekonnen Betelhem , Glaser Bruno , Zech Michael , Bromm Tobias , Nemmomisa Sileshi , Bekele Tamrat , Zech Wolfgang 
Published: May 2023

AbstractIn the Bale Mountains, the ericaceous belt ranges between 3200 and 3800 m asl. Studies indicate an expansion on the Sanetti Plateau at the end of the Late Glacial and during the early Holocene. Currently, only patches of Erica growing between boulders are found on the Plateau, while most of the landscape above 3800 m asl is covered by afro-alpine plants. Driving factors for Erica patches above the upper ericaceous ecotone is a matter of debate. This study evaluates site variables and biogeochemical properties of soils under Erica patches and nearby Erica-free control to understand the environmental conditions responsible for the patchy occurrence of Erica on the Sanetti Plateau. Except for the boulder richness, Erica and control plots have comparable topography, soil texture, and electrical conductivity. However, soils below Erica patches have higher total organic carbon, nitrogen, carbon-to-nitrogen ratios, and black carbon contents than the control plots indicating fresh organic matter input and availability of combustible fuel. This implies that Erica did not fully cover the control plots in former times. Carbon and nitrogen stocks were slightly higher in control plots due to the lower stone contents of the profiles. In addition, soils of the Erica plots showed more positive δ13C values than the control soils, possibly attributed to water stress. In general, the relief and soil conditions of control plots may support the growth of Erica. However, Erica growing between boulders seems to benefit from the favorable microclimate and physical protection against grazing and fire.
Holistic plug-n-play autonomous solar system integration: a real-life small-scale demonstration—a practical approach
Authors: Dimara Asimina , Sougles Christos , Athanasiou Sotirios , Grigoropoulos Konstantinos , Sfakianou Panagiota , Papaioannou Alexios , Krinidis Stelios , Triantafyllidis Dimitrios , Tzitzios Ioannis , Anagnostopoulos Christos-Nikolaos , Karamanidis Aristoklis , Saltagianni Vaia , Ioannidis Dimosthenis , Tzovaras Dimitrios 
Published: May 2023

AbstractAutonomous PV systems offer a substitute for or a safety net against the transmission and distribution companies’ rising and expanding electricity delivery fees. Across the world, delivery fees have climbed by about 3% annually while the cost of energy supply has only gone up by 5% over the past 15 years. In this paper, the drawbacks of PV system integration are highlighted while introducing a unique autonomous PV system. The system is also constructed in a reproducible way so that it can be duplicated. Replicability is showcased by the presentation of two separate PV systems that were created and evaluated using the same methodology. One system uses Si-based conventional photovoltaics, while the other uses dye-sensitized solar cells. The systems that are being offered also support remote connections, allowing all of the data from the PV system to be transmitted to a single endpoint (e.g., a visualization platform). Moreover, the system’s batteries were modified to accommodate the two PV systems. Finally, experimental results showcase the operability of the proposed architecture.
Dual sourcing inventory management with nonconsecutive lead times from a supply chain perspective: a numerical study
Authors: Hamdouch Younes , Boulaksil Youssef , Ghoudi Kilani 
Published: May 2023

AbstractWe study a stochastic multi-period two-echelon dual sourcing inventory system where the buyer can source a product from two different suppliers: a regular and an expedited supplier. The regular supplier is a low-cost offshore supplier, whereas the expedited supplier is a responsive nearshore supplier. Such dual sourcing inventory systems have been well studied in the literature, mostly being solely evaluated from the buyer’s perspective. Since the buyer’s decisions have an impact on the supply chain profit, we adopt the perspective of the entire supply chain, i.e., by taking the suppliers explicitly into consideration. In addition, we study this system for general (nonconsecutive) lead times for which the optimal policy is unknown or very complex. We numerically compare the performance of two different policies in a two-echelon setting: the Dual-Index Policy (DIP) and the Tailored Base-Surge Policy (TBS). From earlier studies we know that when the lead time difference is one period, DIP is optimal from the buyer’s perspective, but not necessarily from the supply chain perspective. On the other hand, when the lead time difference grows to infinity, TBS becomes optimal for the buyer. In this paper, we evaluate the policies numerically (under various conditions) and we show that from a supply chain perspective, TBS typically outperforms DIP at a limited lead time difference of a few time periods. Based on data collected from 51 manufacturing firms, the results of our paper imply for many supply chains with a dual sourcing setting that TBS quickly becomes a beneficial policy alternative, especially given its simple and appealing structure.