bluuebunny/crossref_metadata_2025_split huggingface dataset:
High-velocity impact behavior of hybrid fiber-reinforced epoxy composites
Authors: Stephen Clifton , Shivamurthy B. , Mourad Abdel-Hamid I. , Selvam Rajiv 
Published: August 2021

AbstractIn this study, non-hybrid and hybrid (Kevlar, carbon and glass) fabric epoxy composite laminates were fabricated with different stacking sequences by hand lay-up followed by hot-compression molding. Experimental tests were conducted to investigate tensile, flexural, and hardness characteristics. It was found that the stacking sequence did not significantly affect the tensile strength and hardness values of the composites; however, it affected their flexural strength. Damage morphology of the specimens through SEM images showed that the major damage mechanisms in the composites were delamination, fiber breakage, pull-out, and matrix cracking. Based on the static experimental results, the high-velocity impact behavior was investigated through simulation study using LS-DYNA finite element analysis (FEA) software. To study the ballistic impact, a steel projectile with a hemispherical penetrating edge at impact velocities of 100 m.s−1, 250 m.s−1, and 350 m.s−1 was considered. Among non-hybrid fabric epoxy composite specimens, Kevlar/epoxy specimen was found to have the highest impact energy absorption followed by carbon/epoxy and glass/epoxy, respectively. Regarding the hybrid fabric epoxy composite specimens, the ones with Kevlar plies in the rear face exhibited better energy absorption compared to other stacking sequences. The non-hybrid glass/epoxy specimen had the lowest energy absorption and highest post-impact residual velocity of projectile among all specimens. From the FEA results, it was noted that impact resistance of hybrid composites improved when Kevlar fabric was placed in the rear layer. Thus, the stacking sequence was observed to be of substantial importance in the development of fabric-reinforced composite laminates for high-velocity impact applications.
Vibro-acoustic performance of steel–concrete composite and prestressed concrete box girders subjected to train excitations
Authors: Zhang Xun , Luo Hao , Kong Derui , Chen Tao , Li Xi 
Published: August 2021

AbstractOwning to good mechanical properties, steel–concrete composite (SCC) and prestressed concrete (PC) box girders are the types of elevated structures used most in urban rail transit. However, their vibro-acoustic differences are yet to be explored in depth, while structure-radiated noise is becoming a main concern in noise-sensitive environments. In this work, numerical simulation is used to investigate the vibration and noise characteristics of both types of box girders induced by running trains, and the numerical procedure is verified with data measured from a PC box girder. The mechanism of vibration transmission and vibro-acoustic comparisons between SCC and PC box girders are investigated in detail, revealing that more vibration and noise arise from SCC box girders. The vibration differences between them are around 7.7 dB(A) at the bottom plate, 19.3 dB(A) at the web, and 6.7 dB(A) at the flange, while for structure-radiated noise, the difference is around 5.9 dB(A). Then, potential vibro-acoustic control strategies for SCC box girders are discussed. As the vibro-acoustic responses of two types of girders are dominated by the force transmitted to the bridge deck, track isolation is better than structural enhancement. It is shown that using a floating track slab can make the vibration and noise of an SCC box girder lower than those of a PC box girder. However, structural enhancement for the SCC box girder is extremely limited in effects. The six proposed structural enhancement measures reduce vibration by only 1.1–3.6 dB(A) and noise by up to 1.5 dB(A).
Distribution and modes of occurrence of uranium in coals of Eastern Yunnan, China
Authors: Wang Xin , Feng Qiyan , Meng Qingjun , Liu Fei , Cao Qihang , Liu Guijian 
Published: August 2021

AbstractUranium is an environmentally hazardous element, and is commonly present at trace levels (2.4 μg/g for world coals) in coal deposits. However, selected coal deposits could be highly enriched in uranium. In this study, 15 coal samples were collected from Eastern Yunnan coal deposits, China, aiming to characterize the distribution and the occurrence of uranium in those coals. In studied samples, uranium content varied from 0.36 to 8.28 μg/g, with an average value of 3.76 μg/g. Generally, uranium content in coals from northern coal mines (3.02 ± 2.44 μg/g, n = 5) were lower than it in southern coal mines (4.13 ± 2.30 μg/g, n = 10). Uranium in coal samples showed no obvious correlation with total sulfur, whereas was positively correlated with ash yield. The results of sequential chemical extraction procedure confirm that organic-bound is the dominant occurrence of uranium. The slight enrichment of uranium in studied coals was probably attributed to sedimentation processes, hydrological conditions and tectonic structure of the coal deposits.
Maximal $$L^q$$-Regularity for Parabolic Hamilton–Jacobi Equations and Applications to Mean Field Games
Authors: Cirant Marco , Goffi Alessandro 
Published: August 2021

AbstractIn this paper we investigate maximal $$L^q$$

L
q

-regularity for time-dependent viscous Hamilton–Jacobi equations with unbounded right-hand side and superlinear growth in the gradient. Our approach is based on the interplay between new integral and Hölder estimates, interpolation inequalities, and parabolic regularity for linear equations. These estimates are obtained via a duality method à la Evans. This sheds new light on the parabolic counterpart of a conjecture by P.-L. Lions on maximal regularity for Hamilton–Jacobi equations, recently addressed in the stationary framework by the authors. Finally, applications to the existence problem of classical solutions to Mean Field Games systems with unbounded local couplings are provided.
Entrepreneurial Beliefs and Agency under Knightian Uncertainty
Authors: Westgren Randall E. , Holmes Travis L. 
Published: August 2021

AbstractAt the centenary of Frank H. Knight’s Risk, Uncertainty, and Profit (1921), we explore the continuing relevance of Knightian uncertainty to the theory and practice of entrepreneurship. There are three challenges facing such assessment. First, RUP is complex and difficult to interpret. The key but neglected element of RUP is that Knight’s account is not solely about risk and uncertainty as states of nature, but about how an agent’s beliefs about uncertain outcomes and confidence in those beliefs guide their choices. Second, RUP is Knight’s only effort in this area. His subsequent career led elsewhere, so he did not engage with subsequent interpretations of this work. Third, much of the current literature emphasizes that decisions must be different under the two states of nature with a consequent misunderstanding of entrepreneurial agency. This paper addresses each challenge in sequence. First, we explicate Knight’s (1921) approach and explain why that approach is murky. Second, as a complement to Knight’s interpretation, we examine Frank P. Ramsey’s approach to subjective probabilities to help clarify Knight’s murky approach. What links Knight and Ramsey is a shared pragmatism about entrepreneurial agency under uncertainty that depends upon the beliefs about, and confidence in, their judgments of possible outcomes. This Knight-Ramsey approach does not require actor’s behaviors to be determined by the class of uncertain environment (whether risk, uncertainty, or ambiguity) they face. We focus on the response by the entrepreneur to the existence of uncertainty in all its forms. We argue that this reductive account provides a foundation to examine common problems in management, including managerial hubris, the interaction between entrepreneurs and venture capitalists, and the need for experimentation (such as prototyping and market research) in advance of new product and venture launches. Third, we critique current literature that favors epistemic purism about the ontology of risk and uncertainty and ignores Knight-Ramsey pragmatism in meeting uncertainty, such as using formal and informal institutions for uncertainty mitigation. Our account locates Frank Knight’s subtleties in entrepreneurial behavior firmly in the literature on entrepreneurial agency a century later.
Bidirectional relationship between parental psychological control and adolescent maladjustment
Authors: Yu Xiaoxia , Fu Xinyuan , Yang Zhixu , Zhang Mei , Liu Xiaolan , Fu Yufeng , Lv Yichen 
Published: August 2021

AbstractIntroductionThis study explores the longitudinal and bidirectional relations between paternal/maternal psychological control and adolescent maladjustment (i.e., internalizing symptoms, aggression, and association with deviant peers).MethodsThis longitudinal investigation was conducted at two time points over a one‐year interval with participants comprising 543 Chinese adolescents aged 10 to 13 (mean age at Time 1 = 11.29; 51.93% girls). The performed measurements encompassed paternal/maternal psychological control, adolescent internalizing symptoms, aggression, association with deviant peers, and demographic information.ResultsThe findings of a cross‐lagged model analysis revealed that paternal psychological control was longitudinally and positively related to adolescent internalizing symptoms and aggression. Maternal psychological control was not significantly related to any domain of adolescent maladjustment. In turn, adolescent association with deviant peers was longitudinally and positively associated with both parents’ psychological control.ConclusionsParental psychological control was bidirectionally associated with adolescent maladjustment in general, and paternal psychological control played a crucial role on adolescent maladjustment in the Chinese cultural context. The study's findings supported the reciprocal model of parent–child interaction, and extended it by highlighting the apprehension of the characteristics of parental impact from a cultural perspective. The study results add to the current scholarly understanding of parental psychological control in the non‐western cultural context.
The Super-Predator Effect: How Negative Targeted Messages Demobilize Black Voters
Authors: Stout Christopher , Baker Keith 
Published: August 2021

AbstractThis article assesses whether messages that are framed to denigrate a politician or political entity in the eyes of a particular group – defined here as negative targeted messages – decreases Blacks' enthusiasm to vote. It also explores why such messages are effective at demobilizing Black voters. Using a survey experiment implemented on a nationally representative sample, the authors find that Blacks are less enthusiastic about voting when presented with evidence of racism within their preferred political party. Whites and Latinxs do not respond similarly to the same stimulus. The findings also demonstrate evidence that the effectiveness of negative targeted messages towards Blacks is driven by the treatment's ability to alter perceptions of party empathy. Overall, the results suggest that targeted negative messages can be effective at depressing Black turnout. However, parties may be able to counter this negative messaging with evidence of outreach to minority communities to demonstrate a greater sense of empathy.
Perspectival usages of French past time verbal tenses: an experimental investigation
Authors: Grisot Cristina , Blochowiak Joanna 
Published: August 2021

AbstractIn this paper, we carried out two experimental studies to investigate whether verbal tenses, in their perspectival usages, give access to the speaker’s perspective. Study 1 is an annotation study in which annotators evaluated corpus excerpts as expressing situations or narrating events in a subjective or objective way. We manipulated access to the verbal tense: half of the annotators saw the tense of the verbs, and half saw only infinitive forms of the verbs. Study 2 is a self-paced reading experiment in which we examined how native speakers of French process utterances with the Passé Simple when it is preceded byaujourd’hui(semantic incompatibility solved pragmatically by perspective-taking),hier(semantic and pragmatic compatibility) anden ce moment(semantic incompatibility which cannot be solved pragmatically). The results of Study 1 suggest that the subjective interpretation of an utterance is not triggered by its verbal tense. Study 2 questions the idea that perspective-taking is a component of speaker’s subjectivity. In general, our experimental findings do not support the hypothesis that verbal tenses give access to speaker’s subjectivity, a theoretical hypothesis which has never before been directly experimentally tested.
Use of Naloxone in 9-1-1 Patients without Respiratory Depression in Los Angeles County, California (USA)
Authors: Jenkins Colin , Levine Michael , Sanko Stephen , Kazan Clayton , Thomas Caroline E. , Eckstein Marc 
Published: August 2021

AbstractIntroduction:Along with an increase in opioid deaths, there has been a desire to increase the accessibility of naloxone. However, in the absence of respiratory depression, naloxone is unlikely to be beneficial and may be deleterious if it precipitates withdrawal in individuals with central nervous system (CNS) depression due to non-opioid etiologies.Objective:The aim of this study was to evaluate how effective prehospital providers were in administering naloxone.Methods:This is a retrospective study of naloxone administration in two large urban Emergency Medical Service (EMS) systems. The proportion of patients who had a respiratory rate of at least 12 breaths per minute at the time of naloxone administration by prehospital providers was determined.Results:During the two-year study period, 2,580 patients who received naloxone by prehospital providers were identified. The median (interquartile range) respiratory rate prior to naloxone administration was 12 (6-16) breaths per minute. Using an a priori respiratory rate of under 12 breaths per minute to define respiratory depression, only 1,232 (47.8%; 95% CI, 50.3%-54.2%) subjects who received naloxone by prehospital providers had respiratory depression.Conclusion:This study showed that EMS providers in Los Angeles County, California (USA) frequently administered naloxone to individuals without respiratory depression.
Financial openness, bank capital flows, and the effectiveness of macroprudential policies
Authors: Jin Hao , Xiong Chen 
Published: August 2021

AbstractThis paper quantitatively examines the macroeconomic and welfare effects of macroprudential policies in open economies. We develop a small open economy dynamic stochastic general equilibrium (DSGE) model, where banks choose their funding sources (domestic vs. foreign deposits) and are subject to financial constraints. Our model predicts that banks reduce leverage in response to a macroprudential policy tightening, but increasingly rely on foreign funding. This endogenous shifts of funding composition significantly undermine the stabilizing effect and welfare gains of macroprudential policies. Our results also suggest macroprudential policies are less effective in financially more open economies, and optimal policy should take capital flows into consideration. Finally, we find empirical support for the model predictions in a group of developing and emerging economies.
Estimating the FOMC’s interest rate rule with variable selection and partial regime switching
Authors: Check Adam 
Published: August 2021

AbstractWhen studying the Federal Open Market Committee’s (FOMC’s) interest rate rule, some authors, such as Gonzalez-Astudillo [(2018) Journal of Monetary, Credit, and Banking 50(1), 115–154.], find evidence for changes in inflation and output gap responses. Others, such as Sims and Zha [(2006) American Economic Review 96(1), 54–81.], only find evidence for a change in the variance of the interest rate rule. In this paper, I develop a new two-regime Markov-switching model that probabilistically performs variable selection and identification of parameter change for each variable in the model. I find substantial evidence that there have been changes in the FOMC’s response to the unemployment gap and in the volatility of the rule. When the FOMC responds strongly to the unemployment gap, I find a bimodal density for the inflation response coefficient. Despite the bimodal density, there is a low probability that there have been changes in the FOMC’s response to inflation.
Volume and Heat Transport in the South China Sea and Maritime Continent at Present and the End of the 21st Century
Authors: Samanta Dhrubajyoti , Goodkin Nathalie F. , Karnauskas Kristopher B. 
Published: August 2021

AbstractOcean transports through the Southeast Asian Seas connect the western tropical Pacific and Indian Oceans, thereby exerting an important role in regional and global climate. High‐resolution regional ocean model simulations over the South China Sea (SCS) and maritime continent are used to study the mean and seasonally varying thermohaline structure and volume transport through the straits surrounding the SCS. Diversity in the vertical structure of these straits is not only indicative of the role of widely varying bathymetry but also strong seasonality associated with monsoonal currents. The presence of a Pacific water mass in intermediate and deep layers of the Luzon Strait points to a key pathway between the Pacific and Indian Oceans. Further, examining a suite of global, high‐resolution model simulations reveals the projected changes in the regional upper ocean transports due to anthropogenic radiative forcing by the end of the 21st century. The global models predict an increase in heat and volume transport through the Luzon and Karimata Straits, and a decrease thereof through the Makassar and Lombok Straits by the end of the century. Overall, these changes impute additional net convergence of heat and volume in the SCS, a significant reduction of sea surface salinity and mixed layer depth, and an increase in the upper‐ocean heat content of the region. As the SCS serves as a regional heat capacitor and is impacted by the global thermohaline circulation locally via Indonesian Throughflow, these predicted changes have the potential to impact climate over the Indo‐Pacific region and globally.
Linking Dominant Rainfall‐Runoff Event Hydrologic Response Dynamics With Nitrate and Chloride Load Estimates of Three Boreal Shield Catchments
Authors: Ross C. A. , Casson N. J. , Tenuwara M. 
Published: August 2021

AbstractUnderstanding hydrological dynamics in boreal Shield catchments is critical for projecting changes in stream runoff and chemistry in a region that is, sensitive to climate change. Previous work has mostly focused on a limited number of events over one or a few seasons because of the relative scarcity of high‐frequency datasets and automated tools for rainfall‐runoff event delineation. For the boreal region, a greater understanding of seasonality in hydrologic response and solute export related to rainfall‐initiated events is needed, as significant shifts in hydrologic regimes from climate change are expected. This study aimed to help resolve these knowledge gaps by assessing event‐scale hydrologic response dynamics and stream loads of nitrate and chloride using long‐term data from three boreal Shield catchments. Hydrometric and stream chemistry data from 2001 to 2018 were analyzed to delineate rainfall‐runoff events and estimate event nitrate and chloride loads. Event hydrologic response and loads were highly variable, especially with respect to catchment runoff initiation. Only subtle differences in hydrologic response dynamics were observed between summer and fall events, while seasonal differences in event nitrate and chloride loads were most statistically significant. Interestingly, a wide range of rainfall‐runoff events classified by response magnitude and timing was associated with differences in nitrate and chloride export. This study further confirms the utility of long‐term high‐frequency datasets and illustrates the need for additional work to further assess long‐term changes in event‐based hydrologic response and stream solute concentrations in the boreal region.
Coulomb Stress Modeling and Seismicity in the Western Himalaya, India Since 1905: Implications for the Incomplete Ruptures of the Main Himalayan Thrust
Authors: Parija Mahesh Prasad , Kumar Sushil , Tiwari V. M. , Biswal Shubhasmita , Biswas Arkoprovo , Velliyidathu Arjun 
Published: August 2021

AbstractThe along‐strike terminations of seismic ruptures on the Main Himalayan Thrust (MHT), western Himalayan segment, due to four earthquakes of magnitude (Mw) ≥ 6.6 in 1905–2019 are investigated using the Coulomb failure criterion. For the 1975 Kinnaur earthquake (Mw 6.8), stress perturbations are controlled by the secondary fault structures, which generated stress heterogeneities within the study area and have limited the mainshock rupture propagation in the NW‐SE direction along strike, impeding the rupture to reach the Himalayan front. The ramp geometry of the MHT played a significant role during the 1991 Uttarkashi and 1999 Chamoli earthquakes, inhibiting the seismic ruptures from accelerating toward the surface. Besides, the geometry marks the presence of complex Lesser Himalayan duplexes, which accumulates the resultant coseismic stress from the two earthquakes. The Coulomb stress modeling of the studied earthquakes suggests a lateral increase in stress interactions along the strike for the 1905 Kangra, the 1991 Uttarkashi, and the 1999 Chamoli events and across the strike for the 1975 Kinnaur earthquake in the western Himalaya. Finally, we infer that the tectonic loading of the MHT dominates the present‐day stress perturbations in the western Himalaya.
Longitudinal Evolution of the Velocity of Subauroral Polarization Streams (SAPS) in Different Phases of Magnetic Storms: SuperDARN Observations
Authors: Zhang Qiang , Liu Yong C.‐M. , Zhang Q.‐H. , Xing Zan‐Yang , Ma Yu‐Zhang 
Published: August 2021

AbstractInvestigations of the evolution of subauroral polarization streams (SAPS) are important to understand the plasma transport processes in the polar ionosphere. In this article, three cases of SAPS evolution are analyzed using the observations made by the Super Dual Auroral Radar Network mid‐latitude radar chain, Special Sensor Ultraviolet Spectrographic Imagers instrument and Active Magnetosphere and Planetary Electrodynamics Response Experiment. The three cases occur in the main phase, beginning of recovery phase and end of recovery phase of three magnetic storms. The cases last from 1.5 to 2 h during 1800–0300 MLT (magnetic local time). The observations show that the SAPS velocity evolution is strongly controlled by the ring current injection during the storm main phase. The responses of SAPS velocity are prompt and appear first near the dusk side and then expand to the night side. Besides, the SAPS velocity has a good linear correlation (R = −0.85) with SYMH index during the evolution of the magnetic storm. The SAPS velocity also shows dependence on the AE index and interplanetary magnetic field (IMF) Bz. The correlations between SAPS velocity and AE/Bz increase with the decay of the magnetic storm. However, the effect of substorm/IMF on SAPS velocity is not strong compared to that of the magnetic storm.