bluuebunny/crossref_metadata_2025 huggingface dataset:
Updating neoclassical economics with contemporary conceptions of homo economicus: a bibliometric analysis
Authors: Munien Inderasan , Telukdarie Arnesh
Published: November 2024

The postulation of rationality pervading neoclassical economics, having found to be lacking in veracity, necessitates an update of Homo economicus in neoclassical economics. An empirical formulation of economics predicated on an evolutionary framework of cognitive development is widely akcnowledged to expand the application and utility of economic models and this study identifies the key research areas associated with the contemporisation of neoclassical economics and reviews the extant body of knowledge on the status of the endeavour. A co-occurring keyword procedure is used to perform a bibliometric analysis to evaluate the extent to which the body of knowledge has progressed with updating the conception of Homo economicus in neoclassical economics. Data obtained from the Scopus and Web of Science databases are subjected to treatment by the procedure which ultimately reflects the relevance and quantity of research output related to the objective of updating neoclassical economics. The results show that, apart from the area of cognitive biases, the research contribution from the identified focus areas are insufficient with 14 of the 18 fields contributing only 12% of the research ouput related to the updating of neoclassical economics. The key insight of this study is that while the failures of neoclassical economics have been well documented in the literature, the effort to improve economic predictions to better approach reality by updating the characterisation of Homo economicus with evidence based findings relating to human behaviour is still immature. It is recommended that the computational and analytical tools endowed by the digital revolution be employed to close the research gap enabling the creation of debiasing strategies and acucrate economic predictions.
Synergistic effects of gamma irradiation/salmide®, a sodium chlorite-based oxy-halogen, on microbiological control and the shelf life of chicken breasts
Authors: Abdelkader Reham M. M. , Abolmaaty Assem , Amin Dina H.
Published: November 2024

A novel portable chamber was developed to extend the shelf life of chicken breasts through a synergistic treatment of gamma irradiation and Salmide®, a sodium chlorite-based oxy-halogen. This combination successfully enhanced the shelf life by utilizing a low dosage of gamma irradiation alongside low concentrations of Salmide (200 ppm sodium chlorite). Fresh chicken breast samples were treated with gamma irradiation, then packed in ice containing Salmide within the portable chamber, and subsequently stored for 20 days in a refrigerator at 4 °C ± 1. The study investigated aerobic bacterial counts, sensory analysis, and Thiobarbituric acid (TBA) levels. Results showed that Salmide alone significantly reduced microbial counts and extended shelf life by 8 days. Gamma irradiation at 1 kGy, either alone or combined with Salmide, caused a sequential reduction in total aerobic bacterial counts by 2,3 logarithmic cycles, respectively, extending the storage period to 12 days. Furthermore, a 16 day shelf life extension was achieved with gamma irradiation at 3 kGy, either alone or in combination with Salmide, resulting in a reduction of total aerobic bacteria by 5 logarithmic cycles. This study is the first to employ Salmide in conjunction with gamma irradiation as an innovative technology in a portable chamber to enhance the safety and shelf life of chicken breasts during storage in the designed portable chamber.
The method of radiation risk assessment based on physico-geographical regionalisation: a case study of Carpathians, Poland
Authors: Jędrzejek Filip , Szarłowicz Katarzyna , Stobiński Marcin
Published: November 2024

Radiological assessment of the environment in expansive territories poses significant challenges due to the complexity of spatial and environmental variables. The aim of this study was to use and present the advantages of a physico-geographical regionalisation methodology to improve the precision and effectiveness of radiological assessments in large areas. The study area was a region of the Polish Carpathian mountains with a territory of 19,600 km2. By integrating geographic information systems (GIS) and radiological data, this research analysed a similarity of environmental attributes (soil type, lithology, mineralogy) and absorbed dose rate (ADR) level from the terrestrial origin for populations. Consistency in terms of the nature and origin of the relief and lithological diversity was a key aspect that distinguished the radiological characteristics. Therefore, consistency was observed at the macroregional level according to physiographic mapping. The study demonstrates the utility of macroregionalisation in capturing spatial ADR heterogeneity and provides a new strategy in radiological monitoring.

Graphical Abstract
Generation of short-term follow-up chest CT images using a latent diffusion model in COVID-19
Authors: Kawata Naoko , Iwao Yuma , Matsuura Yukiko , Higashide Takashi , Okamoto Takayuki , Sekiguchi Yuki , Nagayoshi Masaru , Takiguchi Yasuo , Suzuki Takuji , Haneishi Hideaki
Published: November 2024

Purpose

Despite a global decrease in the number of COVID-19 patients, early prediction of the clinical course for optimal patient care remains challenging. Recently, the usefulness of image generation for medical images has been investigated. This study aimed to generate short-term follow-up chest CT images using a latent diffusion model in patients with COVID-19.

Materials and methods

We retrospectively enrolled 505 patients with COVID-19 for whom the clinical parameters (patient background, clinical symptoms, and blood test results) upon admission were available and chest CT imaging was performed. Subject datasets (n = 505) were allocated for training (n = 403), and the remaining (n = 102) were reserved for evaluation. The image underwent variational autoencoder (VAE) encoding, resulting in latent vectors. The information consisting of initial clinical parameters and radiomic features were formatted as a table data encoder. Initial and follow-up latent vectors and the initial table data encoders were utilized for training the diffusion model. The evaluation data were used to generate prognostic images. Then, similarity of the prognostic images (generated images) and the follow-up images (real images) was evaluated by zero-mean normalized cross-correlation (ZNCC), peak signal-to-noise ratio (PSNR), and structural similarity (SSIM). Visual assessment was also performed using a numerical rating scale.

Results

Prognostic chest CT images were generated using the diffusion model. Image similarity showed reasonable values of 0.973 ± 0.028 for the ZNCC, 24.48 ± 3.46 for the PSNR, and 0.844 ± 0.075 for the SSIM. Visual evaluation of the images by two pulmonologists and one radiologist yielded a reasonable mean score.

Conclusions

The similarity and validity of generated predictive images for the course of COVID-19-associated pneumonia using a diffusion model were reasonable. The generation of prognostic images may suggest potential utility for early prediction of the clinical course in COVID-19-associated pneumonia and other respiratory diseases.
The Effect of Hidden Damage on Local Process Variability in Al-10 Pct Si Alloy High-Pressure Die Castings
Authors: Olofsson Jakob , Bogdanoff Toni , Tiryakioğlu Murat , Bramann Horst , Sturm Jörg
Published: November 2024

An approach to evaluate and quantify process variability in the mechanical performance of castings is explored. The process variability describes the effect of hidden damage given to the metal before solidification on the material performance measured by elongation to failure. The approach is demonstrated on a casting produced by high-pressure die casting (HPDC) with different filling conditions in serial production. Statistical analyses have been conducted on data obtained from several positions throughout the casting to determine whether a position is performing differently from other positions. The results show that elongation in most positions follows the same Weibull distribution. However, the local evaluation shows that one position stands out and follows a separate distribution. Casting simulations, Digital Image Correlation (DIC), and Scanning Electron Microscopy (SEM) reveal that this position displays an increased amount of hidden damage that causes the local reduction in elongation. The investigated changes in prefill amount do not significantly affect the material quality, which is more controlled by the quality of the melt and the nature of mold filling.
Biochemical and structural characterisation of thermostable acid- and pepsin-soluble collagens from South African Geelbek (Atractoscion aequidens) scales and its potential application in film formation
Authors: Sibiya Hlalanathi , Bhagwat Prashant , Permaul Kugenthiren , Pillai Santhosh
Published: November 2024

Fish processing typically generates large amounts of non-edible by-products, which contain collagen protein as one of the principal constituents. In this study, the biochemical properties, in vitro fibril-forming potential and film-forming potential of acid (ASC)- and pepsin (PSC)-soluble collagens extracted from the scales of geelbek (Atractoscion aequidens) were evaluated. Based on ultraviolet absorption spectroscopy, electrophoretic pattern, Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM) analysis, both ASC and PSC were classified as type I collagen. Further, amino acid composition analyses confirmed the presence of 326 and 319 glycine residues/1000 residues in ASC and PSC, respectively, which is characteristic of collagen. The collagens were thermally stable, with a maximum transition temperature of 112.27 °C for ASC and 113.41 °C for PSC. The collagens also demonstrated excellent fibril-forming potential, as indicated by SEM analysis. Being a bioactive material, the extracted collagen was further utilised to prepare collagen–chitosan films. The presence of collagen–chitosan interaction was revealed by FTIR spectra examination of the films, confirming a favourable modification of collagen’s secondary structure. Colour, differential scanning calorimetry and dynamic mechanical analysis demonstrated that the collagen–chitosan films had moderate colour indices and enhanced thermal properties. Overall, this study offers insights into biomaterial fabrication using geelbek collagen that could potentially be useful in the biomedical and food industries.

Graphical abstract
Construct, merge, solve and adapt
Authors: Blum Christian
Published: November 2024

The CMSA algorithm for combinatorial optimization is a hybrid technique based on repeatedly solving sub-instances to the original problem instance. The incumbent sub-instance is extended at each iteration by the probabilistic generation of valid solutions to the original problem instance and by adding the components found in these solutions to the sub-instance. In addition, the incumbent sub-instance is reduced at each iteration by removing seemingly useless solution components. In recent years the usefulness of the CMSA algorithm has been shown by a range of applications to different combinatorial optimization problems. In this work, we provide a gentle introduction to CMSA by describing the application to the so-called minimum global domination problem as an example.
Optimization of fermentation conditions for microbial transglutaminase production by Streptoverticillium cinnamoneum KKP 1658 using response surface methodology (RSM)
Authors: Kolotylo Vitaliy , Piwowarek Kamil , Synowiec Alicja , Kieliszek Marek
Published: November 2024

Microbial transglutaminase (MTG) is an enzyme widely used in the food industry because it creates cross-links between proteins, enhancing the texture and stability of food products. Its unique properties make it a valuable tool for modifying the functional characteristics of proteins, significantly impacting the quality and innovation of food products. In this study, response surface methodology was employed to optimize the fermentation conditions for microbial transglutaminase production by the strain Streptoverticillium cinnamoneum KKP 1658. The effects of nitrogen dose, cultivation time, and initial pH on the activity of the produced transglutaminase were investigated. The significance of the examined factors was determined as follows: cultivation time > nitrogen dose > pH. The interaction between nitrogen dose and cultivation time was found to be crucial, having the second most significant impact on transglutaminase activity. Optimal conditions were identified as 48 h of cultivation with a 2% nitrogen source dose and an initial medium pH of approximately 6.0. Under these conditions, transglutaminase activity ranged from 4.5 to 5.5 U/mL. The results of this study demonstrated that response surface methodology is a promising approach for optimizing microbial transglutaminase production. Future applications of transglutaminase include the development of modern food products with improved texture and nutritional value, as well as its potential use in regenerative medicine for creating biomaterials and tissue scaffolds. This topic is particularly important and timely as it addresses the growing demand for innovative and sustainable solutions in the food and biomedical industries, contributing to an improved quality of life.
Novel microneedle patches for transdermal delivery of AP39, a hydrogen sulphide donor, in the treatment of scenarios mimicking neurological disorders
Authors: Balakrishnan Pavanjeeth , Junaid Sarah , Ahmad Shakil , Wang Keqing , Hindalekar Yukta Sameer , Shokr Hala , Upadhya Manoj , Hopkins Sarah , Sacharczuk Jakub , Singh Rana Karan , Anas Al Tahan Mohamad , Juvale Parag , Chan Felix , Sanchez-Aranguren Lissette , Marwah Mandeep
Published: November 2024

Purpose

Neurodegenerative diseases such as Alzheimer’s disease and Parkinson’s disease are debilitating conditions resulting from a progressive degeneration of nerve cells that is attributed to oxidative stress. Given the role of hydrogen sulphide (H2S), an endogenously produced signalling molecule involved in regulating of oxidative stress, exogenous administration of H2S has been proposed as a potential treatment strategy. This research study involved an investigation into the mechanical properties of microneedles loaded AP39 (a H2S donor), their ability to penetrate skin and effectiveness to deliver AP39 across murine skin. Additionally, the study explored the capability of permeated AP39 to release H2S and thus quench H2O2-induced oxidative stress in neuroblastoma cells, SHSY5Y cells.

Methods

Microneedles were prepared using 20% w/v polyvinyl alcohol (PVA) of either 27,000 or 67,000 molecular weights, with or without trehalose 15% w/v. Mechanical and insertion properties of microneedles were determined and optimised formulation applied to murine skin to observe AP39 flux through the skin. Collected media was applied to a microvasculature blood–brain-barrier model to evidence AP39 permeation, following which, permeated AP39 was applied to an oxidative stress scenario in SHSY5Y cells to assess AP39 potential in limiting oxidative stress.

Results

Microneedle fracture testing observed the microneedles produced from polyvinyl alcohol 67,000 with trehalose were best able to withstand compression force applied. Microneedles formulated from PVA 67,000 were best able to penetrate the parafilm model. Further, the PVA 67,000 with trehalose microneedle formulation was observed to pierce murine skin and deliver 32.84 ± 2.11% of applied AP39 across the skin over 32 h. AP39 transport across the HUVEC microvasculature model gave an apparent membrane permeability of 18.6 ± 1.4. Finally, AP39 attenuated H2O2-induced oxidative stress as well as inflammation in SHSY5Y cells; resulting in reduced neurodegeneration burden.

Conclusion

These findings demonstrate that microneedle patches for the transdermal delivery of AP39 may provide a promising clinical approach in the treatment of neurological disorder associated with oxidative stress.
Benchmark Sample Design for the Validation of Residual Stress Measurements by Diffraction: Insights and Practicalities
Authors: Haribabu Gowtham Nimmal , Canelo-Yubero David , Maawad Emad , Faria Guilherme Abreu , Staron Peter , Schell Norbert , Ramadhan Ranggi Sahmura , Cabeza Sandra , Paecklar Arnold , Pirling Thilo , Withers Philip J. , Roy Matthew J.
Published: November 2024

Non-destructive determination of residual stresses can present significant challenges. Two benchmark samples having the same geometry have been developed which can be measured by diffraction techniques and adapted to other material systems to validate RS measurements. While having the same geometry, one was solely elastically loaded while the other had stresses generated by significant plasticity. Measurements by a neutron diffraction and two synchrotron X-ray diffraction instruments (white beam and monochromatic beam) have been made in the ferrite phase at identical locations on S355 ferrite/pearlite steel benchmark samples. Broadly consistent results (± 30–50 MPa) are obtained across the three diffractometers. These results were corroborated by finite element predictions, with standard deviation on differences between predictions and measurements being  ± 22 MPa for benchmarks with elastic sources of stress and ± 77 MPa for the plastically deformed case. Differences in the stresses were found when making near-surface measurements but only when around 80% of the gauge volume was outside the sample. The larger discrepancies between the measurements and the FE model in the plastic case may be due to plastic load transfer from the softer ferrite to the harder cementite during plastic deformation.
Wafer-Scale Ag2S-Based Memristive Crossbar Arrays with Ultra-Low Switching-Energies Reaching Biological Synapses
Authors: Zhu Yuan , Nyberg Tomas , Nyholm Leif , Primetzhofer Daniel , Shi Xun , Zhang Zhen
Published: November 2024

Memristive crossbar arrays (MCAs) offer parallel data storage and processing for energy-efficient neuromorphic computing. However, most wafer-scale MCAs that are compatible with complementary metal-oxide-semiconductor (CMOS) technology still suffer from substantially larger energy consumption than biological synapses, due to the slow kinetics of forming conductive paths inside the memristive units. Here we report wafer-scale Ag2S-based MCAs realized using CMOS-compatible processes at temperatures below 160 °C. Ag2S electrolytes supply highly mobile Ag+ ions, and provide the Ag/Ag2S interface with low silver nucleation barrier to form silver filaments at low energy costs. By further enhancing Ag+ migration in Ag2S electrolytes via microstructure modulation, the integrated memristors exhibit a record low threshold of approximately − 0.1 V, and demonstrate ultra-low switching-energies reaching femtojoule values as observed in biological synapses. The low-temperature process also enables MCA integration on polyimide substrates for applications in flexible electronics. Moreover, the intrinsic nonidealities of the memristive units for deep learning can be compensated by employing an advanced training algorithm. An impressive accuracy of 92.6% in image recognition simulations is demonstrated with the MCAs after the compensation. The demonstrated MCAs provide a promising device option for neuromorphic computing with ultra-high energy-efficiency.
Synergistic Effect of TiO₂ Nanorods Incorporated with Graphene Oxide for Photocatalytic Degradation of Multiple Dyes
Authors: Bhattacharyya Bagmita , Geetha Mithra , Anwar Hayarunissa , Zaidi Shabi Abbas , Sadasivuni Kishor Kumar , Mohamed Maimoona , Sheikh Hanan , Alfarwati Sarya Muhannad , Jarrar Rouzait Anwar
Published: November 2024

The treatment of dye-contaminated wastewater is essential for mitigating environmental and health risks. In this study, we developed a novel nanocomposite, TiO₂-incorporated graphene oxide (TiO₂@GOn), aimed at enhancing the photocatalytic degradation of neutral red dye, which served as the target analyte. The photocatalysis technique was employed, leveraging the excitation of TiO₂ under UV light to generate reactive oxygen species for efficient dye degradation. TiO₂ nanorods were combined with graphene oxide to form the TiO₂@GOn nanocomposite, designed to improve charge separation and enhance catalytic activity. Nanocomposite characterization was carried out using X-ray diffraction (XRD) to determine crystallographic structure, scanning electron microscopy (SEM) to visualize surface morphology, and UV–Vis spectroscopy to evaluate the optical properties and photocatalytic behavior. The TiO₂@GOn nanocomposite demonstrated a synergistic catalytic effect, outperforming pristine TiO₂ and graphene oxide individually in dye degradation. This study introduces a highly efficient nanomaterial for environmental applications, offering a sustainable approach to the treatment of dye pollutants in wastewater.
Similarity between oxygen evolution in photosystem II and oxygen reduction in cytochrome c oxidase via proton coupled electron transfers. A unified view of the oxygenic life from four electron oxidation–reduction reactions
Authors: Yamaguchi Kizashi , Miyagawa Koichi , Shoji Mitsuo , Isobe Hiroshi , Kawakami Takashi
Published: November 2024

Basic concepts and theoretical foundations of broken symmetry (BS) and post BS methods for strongly correlated electron systems (SCES) such as electron-transfer (ET) diradical, multi-center polyradicals with spin frustration are described systematically to elucidate structures, bonding and reactivity of the high-valent transition metal oxo bonds in metalloenzymes: photosystem II (PSII) and cytochrome c oxidase (CcO). BS hybrid DFT (HDFT) and DLPNO coupled-cluster (CC) SD(T0) computations are performed to elucidate electronic and spin states of CaMn4Ox cluster in the key step for oxygen evolution, namely S4 [S3 with Mn(IV) = O + Tyr161-O radical] state of PSII and PM [Fe(IV) = O + HO-Cu(II) + Tyr161-O radical] step for oxygen reduction in CcO. The cycle of water oxidation catalyzed by the CaMn4Ox cluster in PSII and the cycle of oxygen reduction catalyzed by the CuA-Fea-Fea3-CuB cluster in CcO are examined on the theoretical grounds, elucidating similar concerted and/or stepwise proton transfer coupled electron transfer (PT-ET) processes for the four-electron oxidation in PSII and four-electron reduction in CcO. Interplay between theory and experiments have revealed that three electrons in the metal sites and one electron in tyrosine radical site are characteristic for PT-ET in these biological redox reaction systems, indicating no necessity of harmful Mn(V) = O and Fe(V) = O bonds with strong oxyl-radical character. Implications of the computational results are discussed in relation to design of artificial systems consisted of earth abundant transition metals for water oxidation.

Graphical abstract
Fundamental understanding of voltage decay in Li-rich Mn-based layered oxides cathode materials
Authors: Xie Huixian , Xiao Jiacheng , Chen Hongyi , Zhang Boyang , Hui Kwun Nam , Zhang Shanqing , Liu Chenyu , Luo Dong , Lin Zhan
Published: November 2024

To satisfy the needs of modern intelligent society for power supplies with long-endurance ability, Li-rich Mn-based layered oxides (LRMOs) are receiving much attention because of their ultrahigh capacity. However, their real-world implementation is hindered by the serious voltage decay, which results in a continuous decrease in energy density. The understanding on voltage decay still remains a mystery due to the complicated hybrid cationic-anionic redox and the serious surface-interface reactions in LRMOs. Moreover, some of the mechanisms are occasionally contradictory, indicating that the origin of voltage decay is still unclear. As a result, none of the innovative strategies proposed on the basis of mechanisms has effectively alleviated the problem of voltage decay, and voltage decay becomes a long-term distress of LRMOs. Therefore, it is particularly crucial to sort out the mutual relation of various mechanisms, which helps to go back to the source of voltage decay. In this review, we summarize the current mechanisms of voltage decay as structural evolution and oxygen chemistry, and attempt to trace the origin of voltage decay for LRMOs. In addition, we discuss how current researches address the issue with generalized guidance in designing appropriate strategies based on mechanisms.
In vitro slow-growth conservation, acclimatization, and genetic stability of virus-free apple plants
Authors: Lu Xian , Sun Pengpeng , Liu Ruihan , Wang Caiwen , Tong Lu , Tahir Muhammad Mobeen , Ma Xiaoyan , Bao Junhua , Zhang Dong , Wang Minrui , An Na
Published: November 2024

In vitro slow-growth storage has long played an important role in maintaining valuable horticultural materials. It is particularly applicable to the conservation of virus-free materials recovered from meristem culture or shoot-tip cryotherapy. In this study, the apple cultivar ‘Yanfu-6’ and the rootstock genotype ‘Qingzhen-1’ obtained from a virus disinfection program were compared during the establishment of in vitro slow-growth storage programs. At room temperature (25℃), combining with 4.5% sucrose or 0.5% mannitol, extended the conservation period of ‘Yanfu-6’ and ‘Qingzhen-1’to 5 and 9 months, respectively. Decreasing the temperature to 12℃ led to further reduced shoot growth, extending the conservation period to 9 months for ‘Yanfu-6’, while more than 80% of ‘Qingzhen-1’ shoots could be recovered after one year of storage. Similarly, high rooting and acclimatization success levels were obtained for ‘Qingzhen-1’ after one-year storage at 12℃, as well as for the plants that underwent monthly subcultures, but not for ‘Yanfu-6’. The inability to root in ‘Yanfu-6’ was overcome by micrografting onto rootstock ‘Qingzhen-1’, which resulted in a rooting percentage of 83% and an acclimatization success of 77%. In the analysis of genetic stability by next-generation sequencing, reduced levels of single nucleotide polymorphism (SNPs) and insertions and deletions (InDels) were detected in ‘Qingzhen-1’ shoots recovered after one-year storage at 12℃, as compared with shoots that underwent regular subcultures. These results highlight the use of in vitro slow-growth program assisted with micrografting for the conservation of valuable horticultural species.
Dynamic metabolomic and transcriptomic profiling reveals yellow flower development in Camellia perpetua, a rare continuously flowering golden Camellia species
Authors: Zhu Xianliang , Jiang Haidu , Pan Xinfeng , Fu Jiaxin , Peng Lihui , Zhang Jin , Tang Jianmin , Zou Rong , Zhao Bo , Wei Xiao , Chai Shengfeng
Published: November 2024

The golden camellia, a highly valued ornamental plant, belongs to the Chrysantha section, the sole group in the Camellia genus that produces yellow flowers. The cultivation and broader application of this unique species have been significantly hindered by the scarcity of golden camellia and the limited knowledge of the molecular mechanisms governing yellow flower development. To investigate the dynamics of metabolite accumulation and gene expression during the yellow flower formation of C. perpetua, a continuously flowering golden camellia, a comprehensive metabolomic and transcriptomic analysis was performed across five distinct developmental stages. This analysis identified 1,160 metabolites, with flavonoids constituting the largest proportion at 21.6%. Comparative transcriptomic profiling indicated that differentially expressed genes (DEGs) associated with photosynthesis were predominantly active during the early stages of flower development, while DEGs involved in the flavonoid biosynthesis pathway showed a marked increase as the flowers matured. The integrated metabolomic and transcriptomic data highlighted the pivotal regulatory role of the flavonoid biosynthesis pathway in the formation of yellow flowers in C. perpetua, identifying 50 key genes and 17 crucial metabolites and mapping their interaction networks. Furthermore, weighted gene co-expression network analysis pinpointed several hub genes, such as flavonol synthase, which are likely critical to flavonoid production due to their elevated expression levels, particularly in the early bud and yellowing phases. This study provides valuable insights into the molecular pathways that underlie yellow flower development in golden camellia species.
The influence of wind and basin geometry on surge attenuation along a microtidal channel in the western Baltic Sea
Authors: Kiesel Joshua , Knies Arne , Vafeidis Athanasios T.
Published: November 2024

The capacity of river mouths to reduce storm surge water levels upstream, referred to as along-estuary attenuation, has been assessed by several studies. The coastal protection function of semi-enclosed water bodies such as lagoons and channels with narrow inlets remains less explored and generalization is hampered by differences in morphology and hydrodynamic forcing. Here we use a hydrodynamic model to investigate surge attenuation along a microtidal channel with a narrow inlet at the Baltic Sea coast of Germany called The Schlei. We quantify the importance of wind and the contribution of the barrier spit system, which is constricting the inlet, to the reduction of water levels at the landward end of the channel. In addition, we explore the role of dikes in the region for the reduction of peak water levels and coastal flooding. We find effective along-channel attenuation inside The Schlei in its current state, which is mostly a result of the channel’s narrows. However, reduction rates decrease under simplified sea-level rise scenarios. Furthermore, along-channel attenuation is highly variable and can change to substantial amplification depending on hydrometeorological forcing. The barrier spit contributes to along-channel attenuation whereas the effect of existing dikes (or their removal) for along-channel attenuation is negligible.
Crypto-Asset Market Abuse Under EU MiCA
Authors: Barczentewicz Mikołaj , de Gândara Gomes André
Published: November 2024

The new EU Markets in Crypto-Assets Regulation (“MiCA”) emphasises the prevention of market abuse as one of its five main objectives. This paper critically analyzes MiCA’s provisions on market abuse (Title VI), applying the new rules to the primary categories of crypto-asset market integrity risks to provide a coherent interpretation. In doing so, we consider both the pre-existing legal framework for protecting market integrity, chiefly the Market Abuse Regulation (“MAR”), and the unique features of crypto-asset markets. We find that by largely replicating MAR, MiCA presents “new wine in old bottles” challenges, as crypto-assets introduce novel issues that the legislator attempts to address with a subset of existing tools. The extent to which “decentralized finance” (DeFi) activities will incur liability under MiCA’s anti-market abuse provisions remains unclear, particularly regarding various blockchain network participants. Furthermore, classifying MEV strategies as market abuse may prove difficult. The absence of certain safe-harbor provisions present in MAR, such as those for self-insiders and buy-back and stabilisation schemes, may create uncertainty and potentially chill legitimate market behavior under MiCA.
Rotating attosecond electron sheets and ultra-brilliant multi-MeV γ-rays driven by intense laser pulses
Authors: Hu Li-Xiang , Yu Tong-Pu , Cao Yue , Chen Min , Zou De-Bin , Yin Yan , Sheng Zheng-Ming , Shao Fu-Qiu
Published: November 2024

Isolated multi-MeV

$\gamma$

-rays with attosecond duration, high collimation and beam angular momentum (BAM) may find many interesting applications in nuclear physics, astrophysics, etc. Here, we propose a scheme to generate such

$\gamma$

-rays via nonlinear Thomson scattering of a rotating relativistic electron sheet driven by a few-cycle twisted laser pulse interacting with a micro-droplet target. Our model clarifies the laser intensity threshold and carrier-envelope phase effect on the generation of the isolated electron sheet. Three-dimensional numerical simulations demonstrate the

$\gamma$

-ray emission with 320 attoseconds duration and peak brilliance of

$9.3\times 10^{24}$

photons s

${}^{-1}$

mrad

${}^{-2}$

mm

${}^{-2}$

per 0.1

$\%$

bandwidth at 4.3 MeV. The

$\gamma$

-ray beam carries a large BAM of

$2.8 \times 10^{16}\mathrm{\hslash}$

, which arises from the efficient BAM transfer from the rotating electron sheet, subsequently leading to a unique angular distribution. This work should promote the experimental investigation of nonlinear Thomson scattering of rotating electron sheets in large laser facilities.
Judgments and beliefs about climate change: measurement, stability, and behavioral consequences
Authors: Hilbig Benjamin E.
Published: November 2024

In light of the growing threat of climate change and urgency of mitigation at the societal and individual level, an exponentially growing body of research has addressed how and what people think about climate change—ranging from basic judgments of truth and attitudes about risk to predictions of future outcomes. However, the field is also beset by a striking variety of items and scales used to measure climate change beliefs, with notable differences in content, untested structural assumptions, and unsatisfactory or unknown psychometric properties. In a series of four studies (total N = 2,678), scales for the assessment of climate change beliefs are developed that are comprehensive and balanced in content and psychometrically sound. The latent construct structure is tested, and evidence of high rank-order stability (1-year retest-reliability) and predictive validity (for policy preferences and actual behavior) provided.
Slip due to kink propagation at the liquid–solid interface
Authors: Çam Metehan , Goedde Christopher G. , Lichter Seth
Published: November 2024

In Couette flow, the liquid atoms adjacent to a solid substrate may have a finite average tangential velocity relative to the substrate. This so-called slip has been observed frequently. However, the particular molecular-level mechanisms that give rise to liquid slip are poorly understood. It is often assumed that liquid slip occurs by surface diffusion whereby atoms independently move from one substrate equilibrium site to another. We show that under certain conditions, liquid slip is due not to singular independent molecular motion, but to localized nonlinear waves that propagate at speeds that are orders of magnitude greater than the slip velocity at the liquid–solid interface. Using non-equilibrium molecular dynamics simulations, we find the properties of these waves and the conditions under which they are to be expected as the main progenitors of slip. We also provide a theoretical guide to the properties of these nonlinear waves by using an augmented Frenkel–Kontorova model. The new understanding provided by our results may lead to enhanced capabilities of the liquid–solid interface, for heat transfer, mixing, and surface-mediated catalysis.
Active wake-flow control for a notchback Ahmed body driven by a genetically inspired optimization
Authors: He Kan , Minelli Guglielmo , Su Xinchao , Huang Ning , Krajnović Siniša
Published: November 2024

This paper explores active wake-flow control on a notchback Ahmed body using genetically inspired optimization. Hotwire and particle image velocimetry measurements record velocity data and flow structures in the wake. Pulsed jets at four actuation slots (two at the roof trailing edge, two at the side trailing edges) dynamically control the wake to minimize aerodynamic drag. The study achieves up to 9.2 % (without consideration of energy consumption) drag reduction, primarily by manipulating vortices from the roof rear end. The paper elucidates the underlying flow mechanism and evaluates various actuation strategies, highlighting how optimal control leads to reattachment of wake separation at the rear slant, diminishing the slant bubble and promoting downstream reattachment for enhanced drag reduction.
Existence of Bolgiano–Obukhov scaling in the bottom ocean?
Authors: Huang Peng-Qi , Guo Shuang-Xi , Zhou Sheng-Qi , Cen Xian-Rong , Qu Ling , Zhu Ming-Quan , Lu Yuan-Zheng
Published: November 2024

The seminal Bolgiano–Obukhov (BO) theory established the fundamental framework for turbulent mixing and energy transfer in stably stratified fluids. However, the presence of BO scalings remains debatable despite their being observed in stably stratified atmospheric layers and convective turbulence. In this study, we performed precise temperature measurements with 51 high-resolution loggers above the seafloor for 46 h on the continental shelf of the northern South China Sea. The temperature observation exhibits three layers with increasing distance from the seafloor: the bottom mixed layer (BML), the mixing zone and the internal wave zone. A BO-like scaling

$\alpha =-1.34\pm 0.10$

is observed in the temperature spectrum when the BML is in a weakly stable stratified (

$N\sim 0.0018$

rad s

$^{-1}$

) and strongly sheared (

$Ri\sim 0.0027$

) condition, whereas in the unstably stratified convective turbulence of the BML, the scaling

$\alpha =-1.76\pm 0.10$

clearly deviated from the BO theory but approached the classical

$-$

5/3 scaling in isotropic turbulence. This suggests that the convective turbulence is not the promise of BO scaling. In the mixing zone, where internal waves alternately interact with the BML, the scaling follows the Kolmogorov scaling. In the internal wave zone, the scaling

$\alpha =-2.12 \pm 0.15$

is observed in the turbulence range and possible mechanisms are provided.
Turbulence distortion and blockage in the induction zone of a horizontal axis turbine
Authors: Gouder Kevin , Milne Ian A. , Graham Mike
Published: November 2024

Wind tunnel measurements of the incident turbulent velocity fields and axial forces on a horizontal axis turbine and porous disc analogues are reported. The models were tested in both a simulated atmospheric boundary layer (ABL) and in grid turbulence, allowing for a range of turbulence length scale to rotor diameter ratios to be considered. A theoretical framework to account for the combined effect of distortion and potential flow blocking in the induction zone is presented. In the case of very large length-scale turbulence to diameter ratios, where distortion effects are minimal, a quasi-steady approach is adopted for the effect of blocking. For the small length-scale ratio limit, the method is developed from the classical analyses for rapid distortion of turbulence and blockage from flow through a porous sheet of resistance. For general length-scale ratios, an efficient prediction method based on interpolation between the two length-scale ratio extremes is established. For very large length-scale ratios, a quasi-steady theory without distortion is appropriate for a rotor or disc in a simulated ABL. The small length-scale theory is applicable for tests conducted in grid turbulence. The results of the study can inform the prediction and interpretation of typical measurements of turbulence within the induction zone and the fluctuating loads on a rotor, at both prototype and full scale. This is of particular importance to fatigue load assessments.
Experimental characterization and similarity scaling of smooth-body flow separation and reattachment on a two-dimensional ramp geometry
Authors: Simmons D.J. , Thomas F.O. , Corke T.C. , Gluzman I.
Published: November 2024

The results of an experimental investigation of smooth-body adverse pressure gradient (APG) turbulent boundary layer flow separation and reattachment over a two-dimensional ramp are presented. These results are part of a larger archival smooth-body flow separation data set acquired in partnership with NASA Langley Research Center and archived on the NASA Turbulence Modeling Resource website. The experimental geometry provides initial canonical turbulent boundary layer growth under nominally zero pressure gradient conditions prior to encountering a smooth, two-dimensional, backward facing ramp geometry onto which a streamwise APG that is fully adjustable is imposed. Detailed surface and off-surface flow field measurements are used to fully characterize the smooth-body APG turbulent boundary layer separation and reattachment at multiple spanwise locations over the ramp geometry. Unsteady aspects of the flow separation are characterized. It is shown that the first and second spatial derivatives of the streamwise static surface pressure profile are sufficient to determine key detachment and reattachment locations. The imposed streamwise APG gives rise to inflectional mean velocity profiles and the associated formation of an embedded shear layer, which is shown to play a dominant role in the subsequent flow development. Similarity scaling is developed for both the mean velocity and turbulent stresses that is found to provide self-similar collapse of profiles for different regions of the ramp flow. Despite the highly non-equilibrium flow environment, a new similarity scaling proved capable of providing self-similar turbulent stress profiles over the full streamwise extent of flow separation and downstream reattachment.
Flow structures and combustion regimes in an axisymmetric scramjet combustor with high Reynolds number
Authors: Tang Tao , Sun Mingbo , Yan Bo , Wang Zhenguo , Yu Jiangfei , Huang Yuhui , Wang Hongbo , Zhu Jiajian
Published: November 2024

This study investigates the flow structures and combustion regimes in an axisymmetric cavity-based scramjet combustor with a total temperature of 1800 K and a high Reynolds number of approximately 1 × 107. The hydroxyl planar laser-induced fluorescence technique, along with the broadband flame emission and CH* chemiluminescence, is employed to visualize the instantaneous flame structure in the optically accessible cavity. The jet-wake flame stabilization mode is observed, with intense heat release occurring in the jet wake upstream of the cavity. A hybrid Reynolds-averaged Navier–Stokes/large-eddy simulation approach is performed for the 0.18-equivalent-ratio case with a pressure-corrected flamelet/progress variable model. The combustion regime is identified mainly in the corrugated or wrinkled flamelet regime (approximately 102 < Da < 104, 103 < Ret < 105 where

$Da$

is the Damköhler number and

$Re_t$

is the turbulent Reynolds number). The combustion process is jointly dominated by supersonic combustion (which accounts for approximately 58 %) and subsonic combustion, although subsonic combustion has a higher heat release rate (peak value exceeding 1 × 109 J (m3s)−1). A partially premixed flame is observed, where the diffusion flame packages a considerable quantity of twisted premixed flame. The shockwave plays a critical role in generating vorticity by strengthening the volumetric expansion and baroclinic torque term, and it can facilitate the chemical reaction rates through the pressure and temperature surges, thereby enhancing the combustion. Combustion also shows a remarkable effect on the overall flow structures, and it drives alterations in the vorticity of the flow field. In turn, the turbulent flow facilitates the combustion and improves the flame stabilization by enhancing the reactant mixing and increasing the flame surface area.
Turbulence statistics and structures in fully developed open channel flows with periodic surface coverages
Authors: Liu Xiaodong , Law Adrian Wing-Keung
Published: November 2024

Modular floating solar farms exhibit periodic open surface coverages due to the strip configuration of floating modules that support the photovoltaic (PV) panels on top. The associated modulations in the surface boundary layer and its turbulence characteristics are investigated in the present study under fully developed open channel flows. Different coverage percentages of 100 % (i.e. full cover), 60 %, 30 % and 0 % (i.e. open surface) were tested and measurements were obtained using particle image velocimetry. The results showed that the turbulence statistics are similar when the coverage decreases from 100 % to 60 %. However, with 30 %, both the turbulence intensities and Reynolds stresses increase substantially, reaching up to 50 % higher compared with the 100 % coverage, and the boundary layer thickness increases by more than 25 %. The local skin friction beneath the openings increases by 50 %. Analysis of spanwise vortices and premultiplied spectra indicates that the periodic coverage elongates the hairpin vortex packets and reduces their inclination angle, imposing limitations on sustainable coherent structures. At 30 %, flow detachment and smaller-scale vortices become dominant, reducing the mean velocities and increasing the turbulence intensities. Decreasing coverage percentage with flow detachment also shifts the energy transfer to higher wavenumbers, increasing energy dissipation and decreasing the bulk flow velocity. The kinetic energy and Reynolds stress carried by very large-scale motions decreases from 40 %–50 % with the 100 % and 60 % coverage to around 30 %–40 % with the 30 % coverage. Further research studies involving spanwise heterogeneity, higher Reynolds number and varying submergence of PV modules are needed for environmental considerations.
Viscous Marangoni migration of an inviscid bubble by surfactant spreading: an exactly solvable model
Authors: Crowdy Darren G.
Published: November 2024

A model is formulated of a two-dimensional migrating, or swimming, inviscid bubble in a viscous fluid whose unsteady displacement is caused by the spreading over its surface of an initial distribution of insoluble surfactant. Assuming small capillary and Reynolds numbers, and a linear equation of state giving the surface tension as a function of surfactant concentration, the quasi-steady Stokes flow around the bubble is found analytically and explicit formulas are determined for the time-dependent bubble speed and its final overall displacement. At infinite surface Péclet number this is done using a complex version of the method of characteristics to solve a complex partial differential equation of Burgers type. For a finite non-zero surface Péclet number, the problem is shown to be linearizable by a complex variant of the classical Cole–Hopf transformation. The formulation allows general statements to be made on the bubble speed and its total net displacement in terms of the initial surfactant distribution. A weak finite-time singularity in the surface activity associated with an isolated clean point on the bubble surface is also identified and studied in detail.
Ocean literacy and how serious games can play a part: the case of the jellyfish and the microplastics governance game MoreGoJelly!
Authors: Tiller Rachel , Ahlquist Ina Helene , Almås Håvard , Cowan Emily , Dankel Dorothy , Hakvåg Magnus
Published: November 2024

Serious games are a method that can be used to reach the public on complex topics related to the ocean. Although games used for learning generally, and ocean literacy specifically, have developed gradually since the 1970s, it was not until the popularization of digital games, around the turn of the millennium, that serious games rose to prominence in academia. Since then, vast amounts of serious games research have been published each year – chiefly on digital games, but also increasingly on hybrid and analogue games. In this article, we present results from a series of serious games that were played in three geographical regions in Norway with future-generation stakeholders and tie this to ocean literacy. We report on the potential benefits of serious games for learning and motivation based on these results. The games were played within the context of the United Nations Decade of Ocean Science, the sustainable development goals and multilevel governance, with a special focus on microplastic pollution and jellyfish blooms. We argue that using serious games can be beneficial not just for outreach but also as a tool for unintrusive collection of qualitative data in the form of narratives from transcriptions post-gaming session and contribute to ocean literacy.