bluuebunny/crossref_metadata_2025_split huggingface dataset:
Universal law of skin-friction coefficient in a fully developed zero pressure gradient axisymmetric turbulent boundary layer flow
Authors: Ali Sk Zeeshan , Dey Subhasish 
Published: October 2023

Understanding the skin friction in an axisymmetric turbulent boundary layer (ATBL) flow is a key to designing and optimising the flow past axisymmetric bodies, for example, a rocket engine nozzle and a submarine hull. In this study, we propose a universal law of the skin-friction coefficient in an ATBL flow. The flow is steady and fully developed with a zero pressure gradient. The governing equation for the ATBL flow is derived by methodically applying the boundary layer approximation. Subsequently, the scaling law of the Reynolds shear stress, caused by turbulent eddies, at the surface tangential to the wall roughness summits is derived by incorporating the role of transverse curvature. The skin-friction coefficient in a smooth ATBL flow is found to depend on two parameters, namely, the Reynolds number based on the cylinder radius, Rea, and the ratio of boundary layer thickness to cylinder radius, δ/a. The analysis predicts a simple form of the skin-friction coefficient as

${C_f} = 4.56 \times {10^{ - 2}}{[R{e_a}\ln (1 + \delta /a)]^{ - 1/4}}$

, which agrees satisfactorily with the available experimental data and the numerical simulations in all the axisymmetric flow regimes. The proposed law, in the limit of infinite radius, is consistent with the classical law of the skin-friction coefficient in a plane turbulent boundary layer flow as

${C_{f0}}\sim Re_\delta ^{ - 1/4}$

, where Reδ is the Reynolds number based on the boundary layer thickness. This study reveals that, for δ/a < 1, the relative skin-friction coefficient,

$({C_f} - {C_{f0}})/{C_{f0}}$

, follows a linear law with δ

$/$

a.
Persistence of voice pitch bias against policy differences
Authors: Cinar Asli Ceren , Kıbrıs Özgür 
Published: October 2023

AbstractWe use an online experiment to study the relative effect on voter behavior of a candidate’s voice pitch and policy stance. We demonstrate a strong voice-pitch bias: between candidates who are identical in every other aspect, voters are more likely to choose the one with the lower voice-pitch, and more so in elections between men than women candidates. We then introduce a novel phenomenon: persistence of voice-pitch bias is the amount of policy difference needed to compensate for voice-pitch bias. While persistence is also gender-dependent, the effect is now reversed: voice-pitch bias is more persistent in elections between women than men candidates. As a possible mechanism, we show that voters perceive candidates with lower voice-pitch as more competent and trustworthy.
ACHIEVING LOW BACKGROUNDS DURING COMPOUND-SPECIFIC HYDROXYPROLINE DATING: HPLC COLUMN EFFECTS
Authors: Linscott Bethan , Spindler Luke , Cameron Jamie , Chivall David , Wood Rachel 
Published: October 2023

ABSTRACTAccelerator mass spectrometry (AMS) radiocarbon (14C) dating is central to the development of robust chronologies in archaeological and paleoenvironmental contexts spanning the last 50,000 years. For dates to be accurate, samples must be free of exogenous carbon contamination. At the Oxford Radiocarbon Accelerator Unit (ORAU), considerable advancements in the dating of bone collagen have been made through the development of a high performance liquid chromatography (HPLC) method for the dating of the amino acid hydroxyproline, which can mitigate the effects of carbon contamination. However, recent changes in ligand manufacturing methods for the mixed-mode column used in the ORAU protocol (Primesep A, SIELC Technologies; IL, USA) have resulted in unacceptably high analytical backgrounds. Prior to the manufacturing change, backgrounds of > 50k BP were achievable. Since the manufacturing change, a mean background of 32.5k BP has been measured. Due to column bleed, the Primesep A is therefore no longer suitable for 14C measurement of hydroxyproline from older material. Here, we present background data and the chromatography conditions used to isolate hydroxyproline using an alternative column, a preparative-scale Newcrom AH, which shows promising potential as an alternative for the routine isolation and AMS dating of hydroxyproline—especially approaching the age and mass limits of the method.
‘Chống dịch như chống giặc’ (‘Fighting the pandemic like fighting the invader’): Audience agency and historical resources in Vietnam’s early securitisation of Covid-19
Authors: Phan Xuan Dung , Quah Say Jye , To Minh Son 
Published: October 2023

AbstractVietnam’s initial response to Covid-19 was conspicuous for various reasons, including how its attempt at securitisation drew deeply from historical narratives, symbols, and traditions specific to the Vietnamese experience, as well as how the securitisation project was not simply top-down and state-driven but also featured ground-up participation where the public was mobilised to participate in and actively reiterate securitisation practices. This richly textured empirical case study of the workings of Vietnamese society and politics represents an invitation to explore key debates surrounding securitisation theory. Reflecting on the empirical material of the case, this paper builds on scholarship seeking to highlight the shortcomings of the Copenhagen School’s model of securitisation and from there further explore securitisation theory and its limits. It takes aim at how the audience and its agency is conceptualised in the theory and develops the notions of ‘historical resources’ and ‘activation architecture’ to more adequately explain the processes of securitisation.
Using Sea Level to Determine the Strength, Structure and Variability of the Cape Horn Current
Authors: Zheng Qi , Bingham Rory , Andrews Oliver 
Published: October 2023

AbstractThe Cape Horn Current (CHC) is one of the components of the Antarctic Circumpolar Current system that enables it to fulfill its crucial role as a conduit between ocean basins. Despite this, to‐date there have been very few measurements of CHC strength and none continuous in time or space. Here, we use a combination of ocean models, one free‐running and one data‐assimilating, and satellite altimetry (1993–2021) to estimate the time‐dependent strength of the CHC at 10 transects along its length. We find the time‐mean CHC transport increases from 0.4 ± 0.5 Sv near 49°S to 5.3 ± 2.2 Sv at Cape Horn, with peak‐to‐peak interannual fluctuations of 0.8–3.4 Sv. Although, theoretically, increased run‐off from a wasting Patagonian Ice‐field would strengthen its flow, the CHC appears quite stable over the last 29 years, with little evidence of a coherent, long‐term increase or decrease in the strength of the current.
SM2RAIN-Climate, a monthly global long-term rainfall dataset for climatological studies
Authors: Mosaffa Hamidreza , Filippucci Paolo , Massari Christian , Ciabatta Luca , Brocca Luca 
Published: October 2023

AbstractA reliable and accurate long-term rainfall dataset is an indispensable resource for climatological studies and crucial for application in water resource management, agriculture, and hydrology. SM2RAIN (Soil Moisture to Rain) derived datasets stand out as a unique and wholly independent global product that estimates rainfall from satellite soil moisture observations. Previous studies have demonstrated the SM2RAIN products’ high potential in estimating rainfall around the world. This manuscript describes the SM2RAIN-Climate rainfall product, which uses the European Space Agency (ESA) Climate Change Initiative (CCI) soil moisture v06.1 to provide monthly global rainfall for the 24-year period 1998–2021 at 1-degree spatial resolution. The assessment of the proposed rainfall dataset against different existing state-of-the-art rainfall products exhibits the robust performance of SM2RAIN-Climate in most regions of the world. This performance is indicated by correlation coefficients between SM2RAIN-Climate and state-of-the-art products, consistently exceeding 0.8. Moreover, evaluation results indicate the potential of SM2RAIN-Climate as an independent rainfall product from other satellite rainfall products in capturing the pattern of global rainfall trend.
The metagenomic and metabolomic profile of the gut microbes in Chinese full-term and late preterm infants treated with Clostridium butyricum
Authors: Li Hong , Ma Xingling , Li Yongfu , Liu Qin , Tian Qiuyan , Yang Xiaofeng , Zhou Zhemin , Ren Jing , Sun Bin , Feng Xing , Zhang Hong , Yin Xiaoping , Li Heng , Ding Xin 
Published: October 2023

AbstractThe present study investigated the composition, abundance, and diversity of gut microbes in full-term and late-preterm infants from a medical center in eastern China. A total of 144 genomes of stool samples were captured for 16S rRNA metagenomic analyses. A high abundance of commensal intestinal bacteria was detected in these samples such as Phocaeicola vulgatus, Escherichia coli, and Faecalibacterium prausnitzii, indicating a relatively consistent diversity of gut microbes in the present full-term infants aged 38–40 weeks. However, late preterm infants (n = 50) with mandatory antimicrobials feeding exhibited lower diversity but a higher composition of opportunistic pathogens such as Enterococcus species. Centralized on the situation, we explored the regulatory effect of Clostridium butyricum as probiotics on these late preterm infants. The consumption of C. butyricum did not restore the composition of gut microbes altered by antimicrobials to normal levels, although several opportunistic pathogens decreased significantly after probiotic therapy including Staphylococcus aureus, Sphingomonas echinoides, and Pseudomonas putida. We also compared the effects of day-fed versus night-fed probiotics. Intriguingly, the nighttime feeding showed a higher proportion of C. butyricum compared with probiotic day-feeding. Finally, fecal metabolome and metabolites were analyzed in late preterm infants with (n = 20) or without probiotic therapy (n = 20). The KEGG enrichment analysis demonstrated that vitamin digestion and absorption, synaptic vesicle cycle, and biotin metabolism were significantly increased in the probiotic-treated group, while MSEA indicated that a series of metabolism were significantly enriched in probiotic-treated infants including glycerolipid, biotin, and lysine, indicating the complex effects of probiotic therapy on glutathione metabolism and nutrients digestion and absorption in late preterm infants. Overall, this study provided metagenomic and metabolomic profile of the gut microbes in full-term newborns and late preterm infants in eastern China. Further studies are needed to support and elucidate the role of probiotic feeding in late preterm infants with mandatory antimicrobial treatment.
Mathematical modeling of disinformation and effectiveness of mitigation policies
Authors: Butts David J. , Bollman Sam A. , Murillo Michael S. 
Published: October 2023

AbstractDisinformation is spread to manipulate public opinion for malicious purposes. Mathematical modeling was used to examine and optimize several strategies for combating disinformation—content moderation, education, and counter-campaigns. We implemented these strategies in a modified binary agreement model and investigated their impacts on properties of the tipping point. Social interactions were described by weighted, directed, and heterogeneous networks. Real social network data was examined as well. We find that content moderation achieved by removing randomly selected agents who spread disinformation is comparable to that achieved by removing highly influential agents; removing disinformation anywhere in a network could be an effective way to counter disinformation. An education strategy that increases public skepticism was more effective than one that targets already biased agents. Successful counter-campaign strategies required a substantial population of agents to influence other agents to oppose disinformation. These results can be used to inform choices of effective strategies for combating disinformation.
Enhancement of various images using coefficients obtained from a class of Sakaguchi type functions
Authors: Aarthy B. , Keerthi B. Srutha 
Published: October 2023

AbstractDigital image processing has a wide range of uses, including robotics and automated inspection of industrial parts. Other uses include remote sensing using satellites and other spacecraft, image transmission and storage for business applications, medical processing, and Acoustic image processing. The process of highlighting particular intriguing features in a hidden image is known as image enhancement. We can accomplish this by altering the brightness, contrast, etc. The generated output is more suitable than the original image for some particular purposes. The proposed algorithm which is based on the convolution of coefficient bounds of a subclass $$p-\Upsilon {\mathcal {S}}^*(t,\delta ,\mu )$$

p
-
Υ

S

∗

(
t
,
δ
,
μ
)

obtained using Mittag-Leffler type Poisson Distribution is tested on three image data sets with different dimensions and image formats (PNG, JPEG, TIFF, etc.) and its PSNR, SSIM, MSE, RMSE, PCC and MAE values are observed to check the quality of the enhanced images.
The South America Low-Level Jet: form, variability and large-scale forcings
Authors: Jones Charles , Mu Ye , Carvalho Leila M. V. , Ding Qinghua 
Published: October 2023

AbstractNortherly low-level jets (LLJ) along the eastern Andes are important conduits of moisture transport and play central roles in modulating precipitation in South America. This study further investigates the variability of the LLJ during extended austral summers. A new method characterizes the spatial extent of the LLJ and finds four distinct types: Central, Northern, Andes and Peru. We show the existence of specific evolutions such that the LLJ may initiate in the central region, expands along the Andes and terminates in the northern region. Conversely, the LLJ may propagate from north-to-south. The spatiotemporal evolution of the LLJ is remotely forced by Rossby wave trains propagating from the Pacific Ocean towards South America, and the different phases of the wave trains favor the occurrences of Central, Northern or Andes types. Occurrences of Central and Northern types are more frequent in El Niño and La Niña years, respectively. The persistence of precipitation is shown to be directly related to the persistence of the LLJ. Lastly, the Madden-Julian Oscillation plays an important role in generating wave trains modulating the frequency of LLJ, especially the Central type.
Earthquake size distributions are slightly different in compression vs extension
Authors: Taroni Matteo , Carafa Michele Matteo Cosimo 
Published: October 2023

AbstractThe earthquake size distribution is described by an exponential function governed by the b-value parameter. It has already been proven that the b-value depends on the differential stress and tectonic settings. Here, we propose a new method to group earthquakes using the kinematics of the interseismic geodetic strain rates and horizontal stress directions. We select the Italian peninsula as a case study, and we find that the b-value is significantly larger in the extensional setting than in the compressional one, although these differences are much smaller than previously reported. We also show that spatial fragmentation of uniform tectonic regimes leads to inaccurate b-value estimation due to the undersampling of earthquake size distribution. Given these results, we conclude that stress directions and geodetic data complement other geological or geophysical information and reduce the arbitrariness in drawing zones for a seismotectonic model.
Tandem phospha-Michael addition/cyclization/dehydration of 2-hydroxychalcones with H-phosphine oxides for the synthesis of 4-phosphorylated 4H-chromenes
Authors: Wen Zhong , Yang Kai-Cheng , Zheng Shi-Lu , Zhang Yu-Shan , Wang Sheng-Jun , Ni Hai-Liang , Chen Long 
Published: October 2023

A Hg(OTf)2-catalyzed tandem phospha-Michael addition/cyclization/dehydration of 2-hydroxychalcones with H-phosphine oxides was reported, which allowed construction of C–P and C–O bonds in newly generated 4-phosphorylated 4H-chromenes in good yields.
Finite‐time adaptive fuzzy tracking control for high‐order nonlinear time‐delay systems with dead‐zone
Authors: Lu Kexin , Wang Huanqing 
Published: October 2023

AbstractIn this paper, the adaptive fuzzy finite‐time tracking control problem is studied for a class of non‐strict feedback high‐order time‐delay systems with unknown dead‐zone. The fuzzy logic systems are introduced to approximate the uncertain nonlinear functions in the system. The Lyapunov–Krasovskii (L–K) functional technology is used to compensate for the unknown time delays. In addition, based on the backstepping technique and finite‐time theory, an adaptive fuzzy finite‐time tracking controller is designed to ensure that the closed‐loop system is semi‐global practical finite‐time stability, and the tracking error can converge to a small neighbourhood around the origin within a finite time. Finally, the rationality of the proposed method is verified by simulation results.
Ambiguity function analysis of iridium burst transmissions for opportunistic navigation
Authors: Luo Ruidan , Chen Xiao , Wu Zhongwang , Li Yaping 
Published: October 2023

AbstractThe objective of this work is to investigate the Ambiguity Function (AF) characterization of the Iridium L‐band downlink burst transmissions under single burst and multiband multi‐burst mode to demonstrate its suitability and capability as Signal of OPportunity (SoOP) for navigation. The Iridium bursts are collected and examined by demodulating without any prior knowledge for frame verification. The comprehensive analysis and theoretical model of the two mode AFs are presented and verified to evaluate the waveform properties with resolution and sidelobes in both the Doppler and delay domains. Degradation in AF resulting from signal model and multiband channel combination is characterized to exploit the trade‐offs for selection and utilization of the Iridium burst. It has been found that the single burst even with maximum length of 20.32 ms appears available but far from excellent for navigation, while the multiband mode produces significant improvements over the time delay and Doppler resolution as well as a certain degradation on the AF sidelobes. Issues relating to the Iridium bursts utilization have been identified.
Research on dual‐winding permanent magnet generator system with integrated dual‐channel controller
Authors: Han Jianbin , Zhang Zhuoran 
Published: October 2023

AbstractThis article presents a dual‐winding permanent magnet generator (PMG) system with integrated dual‐channel controller to meet the requirements of high power density, high reliability, and high output performance of aircraft electric power system. The dual‐winding of the PMG are designed to have the same phase spatially, with which the same rotor position can be applied in independent vector control. In addition, a dual‐channel controller is applied to control the two sets of windings, which achieves high‐performance control under normal state and fault‐tolerant control under fault state. The integrated dual‐channel controller integrates two sets of main power circuits into one controller and uses a main control unit, which simplifies the PMG system leading to reduction in the overall volume and weight. Reliability analysis of dual‐winding PMG system is proposed to be compared with that of the single‐winding PMG system. A dual‐winding cooperative control strategy and a fault‐tolerant control strategy are proposed to achieve high‐performance control of DC‐link voltage under normal condition and redundant functions under fault condition. As a result, the reliability of the PMG system is improved. The experimental results validate the effectiveness of the proposed PMG system and the control strategy.
anti-Selective Synthesis of Substituted β-Homoprolines by Rhodium Alkyl Nitrene C–H Insertion
Authors: Noda Hidetoshi , Shibasaki Masakatsu , Tang Xinxin 
Published: October 2023

AbstractA range of β-homoprolines was prepared with high anti-selectivity. An intramolecular C–H insertion reaction involving a rhodium alkyl nitrene is a key step in the ring construction. The carboxylic acid in the products can serve as a springboard for further downstream transformations.
A melhora da mobilidade e da força isométrica do tronco se correlacionam com a melhora da dor e da incapacidade após a reabilitação multimodal para dor lombar?
Authors: Jain Shikha , Shetty Gautam M. , Linjhara Sanya , Chutani Neha , Ram C. S. 
Published: October 2023

Resumo
Objetivo Determinar a correlação entre a amplitude de movimento (ADM) do tronco pós-tratamento e a força isométrica do tronco (FIT) e a dor e a incapacidade em pacientes submetidos à reabilitação multimodal para dor lombar (DL).
Métodos Neste estudo de coorte prospectiva, 122 pacientes submetidos à reabilitação multimodal para DL foram analisados. Foram comparados os escores de escala numérica de dor pré- e pós-tratamento (END) e do índice de incapacidade Oswestry (Oswestry disability index – ODI), a ADM do tronco e a FIT. A correlação de Pearson foi utilizada para determinar a correlação entre desfechos clínicos e a ADM e a FIT pós-tratamento.
Resultados Ao final do tratamento, as médias de ADM (p < 0,0001) e ODI (p < 0,0001), as ADMs médias de extensão (p < 0,0001) e a flexão (p < 0,0001) do tronco melhoraram significativamente. Da mesma forma, a FIT pós-tratamento, as FITs médias de extensão (p < 0,0001) e flexão (p < 0,0001) melhoraram significativamente. Houve uma correlação fraca entre o escore do END e a ADM de extensão (r = -0,24, p = 0,006) e força de flexão (r = -0,28, p = 0,001) pós-tratamento, assim como entre o escore de ODI e FIT de extensão (r = -0,30, p = 0,0007) e flexão (r = -0,28, p = 0,001) pós-tratamento.
Conclusão Apesar da melhora significativa da dor, capacidade, ADM do tronco e FIT com tratamento multimodal, houve uma fraca correlação entre dor pós-tratamento e função e ADM e FIT de tronco. A melhora da dor e da função com o tratamento de reabilitação física para DL é um fenômeno complexo e precisa de uma investigação mais aprofundada.
Wine conceptualizing and lexicalization in Indo-European
languages
Authors: Fernandez Sanchez Eulalio 
Published: October 2023

Abstract
Translation and typological studies have traditionally evidenced
the significant prevalence of the lexeme ‘wine’ in most Indo-European-based
languages. The somehow universal presence of this term has been explained by
the insight provided by etymologists, linguists, historians, archaeologists
and anthropologists, amongst others. Such an interdisciplinary approach
unveils the complex network of factors required for understanding the
context in which this term was originated within a particular culture, at a
given time in history and how it became part of the lexicon of most
languages not only spoken in Europe, but also in other language families.
Based on that interdisciplinary evidence, it is possible to
ascertain when and how the term ‘wine’
arose and spread west and east all over Europe, Indo-Asia and down to the
north of Africa. Our contribution intends to broaden this approach by
introducing a new question, that is, why. Whether a single
process of conceptualizing originated in just one Indo-European language or
an analogous process resulting from a similar morphological process, the
lexicalization of ‘wine’ has proved successful. We will endeavour to explain
the reasons for that successful choice, which no doubt reveals that it was
not an arbitrary one but based on a socio-linguistic context that favoured
culturally the choice of an existing root and the lexicalization of
grammatical and phonological varieties in different Indo-European
languages.”