bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nonlinear Normal Modes-Related Isolated Branches of Subharmonic Solutions for Forced Response Blade-Tip/Casing Contact Problems
Authors: Vadcard Thibaut , Thouverez Fabrice , Batailly Alain 
Published: September 2024

Abstract
This article investigates the emergence of isolated branches of solutions for blade-tip/casing structural contact configurations by means of a numerical procedure relying on Melnikov's energy principle. This study is carried out on the open fan blade model NASA rotor 67 in order to promote the reproducibility of the results. The blade is subjected to an harmonic forcing so as to initiate rubbing interactions. Contact is modeled in the frequency domain by the dynamic Lagrangian frequency-time harmonic balance method (DLFT-HBM) that accounts for vibro-impact as well as dry friction. This paper employs an isola detection procedure that was shown to give accurate results on such highly nonlinear applications. Several types of harmonic forcing are applied to the blade in order to observe subharmonic (i.e., with a fundamental frequency expressed as a fraction of the excitation frequency) isolated solutions. The existence of these solutions is shown to be related to nonlinear normal modes that feature lower periodicities than the excitation. The periodicity of the solutions is assumed to be linked to the periodicity of the nonlinear normal modes from which these solutions emerge. In some configurations, it is shown that nonlinear periodic solutions exist in the form of isolated branches while the main predicted response remains within the linear domain. This behavior is particularly detrimental since numerical strategies tackling nonlinear problems are usually not put to use when the response of the system is expected to be linear. The existence of such solutions is cross-checked by means of reference time integration simulations. Finally, an excitation of random shape is applied to show that this complex phenomenon persists for nonsimplified excitation shapes.
Probabilistic Modeling Geometric Tolerance and Low Cycle Fatigue Life of Gas Turbine Compressor Blade
Authors: Meng Zhiqiang (David) , Bluck Richard , Sjödin Björn 
Published: September 2024

Abstract
This paper presents a probabilistic low cycle fatigue (LCF) assessment for geometric tolerances on high load contact surfaces of gas turbine compressor blades. The typical patterns of the geometric deviations for the root contact flank of the compressor blades are identified and characterized according to coordinate measurement machine (CMM) measurements of the blade root. These typical patterns are closely related to the root form manufacture tools and process. Finite element (FE) models for the typical geometric deviation patterns are created based on nodal coordinates transformation of the surface nodes on the blade root contact flanks and radius. An optimized blade root profile tolerance is established, which enables significant cost saving. The elastic-plastic FE analysis with nonlinear contact model, material strain-life test, response surface, and constrained Monte Carlo simulation are used to create a probabilistic LCF life model for the optimized tolerance. The model quantifies the effect of the geometric deviations, blade mass, and material property on the blade LCF life. The result shows that with the optimized tolerance, the probability of blade LCF failure is very low and acceptable. It is also shown that the strain life material property is the most critical factor for the LCF failure. The root profile tolerance and blade mass are seen to have a much weaker effect on the blade LCF life.
A Review of Numerical Methodologies for Predicting Rotating Stall and Surge in High-Speed Centrifugal Compressors
Authors: Neri Francesco , Hickel Stefan , Pini Matteo 
Published: September 2024

Abstract
High-speed supersonic radial compressors are a critical enabling technology for meeting the requirements of future aviation-propulsion and thermal-management systems. These turbomachines must be designed to be both efficient and robust on the widest possible operating range. Flow instabilities in the form of rotating stall and surge are therefore phenomena that must be accurately predicted early in the design process. Unsteady full-annulus computational fluid dynamics (CFD) can be used to get accurate information about the onset of instabilities, but at the expense of costly simulations. As a result, the design of new compressors continues to rely on existing correlations for the prediction of the critical mass flowrate. This approach, however, leads to suboptimal compressor designs. This article provides a review of the numerical methodologies that can be used for the accurate prediction of the critical mass flowrate in high-speed centrifugal compressors. Methods of different fidelity level and computational cost are described. Two particularly promising models, namely, those proposed by Spakovszky and Sun, are subsequently examined in more detail. Exemplary applications of these two models are finally discussed.
The Effect of Air–Water Mixture on the Dynamic Response of a Hydrodynamic Journal Bearing With Inclined Grooves
Authors: Voitus Anthony , Arghir Mihai , Hassini Mohamed-Amine 
Published: September 2024

Abstract
Water-lubricated hydrodynamic journal bearings with deep inclined grooves are often used to support radial loads and dampen pump vibrations in nuclear power plants. The inclined grooves increase the pumping effect of the lubricant thus reducing wear and friction during rotor startup and coast-down. The deep grooves also facilitate the removal of debris without damaging the bearing. The load capacity and the stability of this type of bearing are studied in the present work. A sensitivity study of the impact of the number of grooves on bearing performance underlined the superiority of the journal bearing with two inclined grooves. Moreover, these journal bearings may operate with a mixture of water and air. This compressible two-phase lubricant will modify the load capacity and the stability of the journal bearing. The impact of the ingested volume fraction of air is therefore investigated. A physical model of the homogeneous air–water mixture linking the local air volume fraction with the pressure was used in conjunction with the numerical solution of the compressible Reynolds equation on an unstructured grid. It was found that the air ingestion in the two-inclined grooves journal bearing decreases the load capacity but improves the stability for mild and low loads.
Interplay Between Unburned Emissions and NOx Emissions From a Dual Swirl Hydrogen Air Injector
Authors: Magnes Hervé , Vilespy Martin , Selle Laurent , Poinsot Thierry , Schuller Thierry 
Published: September 2024

Abstract
OH planar laser induced fluorescence (OH-PLIF) and particle image velocimetry (PIV) are employed to analyze the structure of hydrogen/air flames stabilized by a dual swirl injection system under globally lean and atmospheric conditions with preheat air temperature varied from ambient up to 673 K. The flames exhibit two distinct reaction branches. The first, located in the central recirculation zone (CRZ), is a diffusion-controlled reaction layer characterized by a relatively large thickness associated with low strain rates. The second branch, stabilized in the shear layer of the swirling jet, is strongly influenced by large coherent structures. Depending on operating conditions, this front may adopt either the form of a fully diffusive strained reaction layer anchored to the hydrogen injector lip or a lifted diffusion front with a leading-edge flame evolving into a partially premixed flame at high air injection velocities. Flue gas analysis indicates NOx emission levels, typically below 10 ppm at 15% O2, for sufficiently large air injection velocities. Air preheating barely increases NOx emissions at lean operating conditions. The injector operational range is constrained only by the ultralean blowout limit reached for global equivalence ratios below 0.02. Furthermore, it demonstrates remarkable resilience to large and rapid drop in fuel flow rate. However, combustion efficiency drops close to the lean blowout (LBO) limit due to intermittent fragmentation of the flame wings that progresses further upstream as the equivalence ratio drops. The results demonstrate that fragmentation arises from the combined effects of a temperature drop in the central recirculation zone and the flame wings being exposed to high shear stress. Additionally, it is shown that combustion efficiency under ultralean conditions improves significantly with an increase in air preheat temperature.
Anti-Inflammatory Effects of Lupeol as a Candidate for New Drug Development
Authors: Park Yun Jin , Park Dong Ho , Bae Jong-Sup 
Published: September 2024

This study explores the anti-inflammatory properties of lupeol, a notable phytosterol found in various medicinal plants, highlighting its potential as a candidate for new drug development. We examined the effects of lupeol on heme oxygenase (HO)-1, cyclooxygenase (COX)-2, and inducible nitric oxide synthase (iNOS) in lipopolysaccharide (LPS)-stimulated human umbilical vein endothelial cells (HUVECs), as well as its impact on inflammatory markers in the lung tissues of LPS-challenged mice. Lupeol treatment enhanced HO-1 production, inhibited nuclear factor (NF)-κB activity, and reduced levels of COX-2/prostaglandin E2 (PGE2) and iNOS/nitric oxide (NO). In addition, lupeol decreased the phosphorylation of signal transducer and activator of transcription 1 (STAT-1) and promoted the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2), enhancing its binding to the anti-oxidant response element (ARE) and subsequently reducing interleukin (IL)-1β expression. In vivo, lupeol significantly lowered iNOS expression and tumor necrosis factor (TNF)-α levels in bronchoalveolar lavage fluid from LPS-treated mice. These findings suggest that lupeol exerts its anti-inflammatory effects by modulating key signaling pathways, positioning it as a promising candidate for the development of novel therapeutics targeting pathological inflammation.
Determination of population stock units of Portunus sanguinolentus (Herbst, 1783) as a non-target species (secondary species) using Truss Network Analysis on Madura Island
Authors: Astuti Anggini F. , Ismet Meutia S. , Zamani Neviaty P. , Madduppa Hawis H. 
Published: September 2024

Abstract
The blue swimming crab is one of the fishery commodities that constitute the major component of Indonesia’s third highest export products after shrimp and fish. The slightly expensive crabs in the market include Portunus pelagicus, which is commonly found in Indonesia alongside Portunus sanguinolentus. However, P. sanguinolentus is considered a secondary species due to the lower catch numbers in the country, specifically on Madura Island. The research about this particular crab is still very limited and the importance of information on secondary species stock units is to restore degraded ecosystems through appropriate programmes. Truss Network Analysis (TNA) was applied to measure the crab’s morphometric characteristics. The Kruskal–Wallis test, cluster analysis, and discriminant analysis were the statistical methods used to identify the stock units. The results showed different characteristics of swimming crabs in four locations on Madura Island, namely in the Bangkalan, Sampang, Pamekasan, and Sumenep Regencies. These indicated that different characteristics exist in male crabs found in Bangkalan, Sumenep, and Sampang, which have the highest level of similarity. In contrast, the females formed two clusters consisting of the groups Sampang and Sumenep, as well as Bangkalan and Pamekasan. The group differences show the potential of all crabs in the four locations to have more than one stock unit, hence their management needs to be differentiated.
A long-term capture-mark-recapture survey of the European lobster, Homarus gammarus (Linnaeus, 1758) (Decapoda, Nephropidae) at Aguda’s Beach in north Portugal
Authors: Weber Mike , Pinho Ruben 
Published: September 2024

Abstract
The European lobster population on Aguda’s Beach was studied between 2006 and 2023 through an annual capture-mark-recapture survey. The primary objective was to assess the abundance, sex ratio, and growth of lobsters, serving as a basis for future investigations on population density, survival, migration, and site fidelity. In the 18-years sampling period, 5 traps were set on 892 fishing days, from May and September each year, resulting in the capture of 320 lobsters in an experimental fishing area covering approximately 0.4 km2, off Aguda’s Beach. The catch rate of the experimental fishery varied from 0.01 to 0.15 lobsters per trap, with an overall mean of 0.07 animals per trap. To augment the number of tagged individuals for the survey, 397 lobsters were obtained over the years from the local commercial fishery, which operated in an area approximately 10 times as large as the experimental fishing area. Out of the total number of 717 lobsters, 512 specimens were marked and released in the experimental fishing area. Between 2009 and 2022, 31 males and 15 females were caught again, resulting in a mean recapture rate of 8.9%. The maximum time a lobster spent at sea before being recaptured was 11.9 years, while the minimum was 2 months. Over the 18-year survey period, the mean absolute growth rate of 46 recaptured lobsters was 467 ± 33 g SE (standard error) and 3.3 ± 0.2 cm CL (carapace length) per year. Males achieved an average rate of 509 ± 38 g and 3.1 ± 0.3 cm CL, while females presented a rate of 379 ± 58 g and 3.6 ± 0.3 cm CL.
The findings of this long-term survey did not support a decline in the lobster population at Aguda’s Beach over time, what might be attributed to the decrease of the commercial fishing activity. Additionally, the population also seemed to exhibit a certain mobility, as evidenced by reduced recapture rates in recent years. The range of annual growth rates indicated a diverse composition of the population, with male lobsters exhibiting growth patterns similar to females but revealing greater activity, which led to recapture rates nearly twice as high.
The comparison of morphological characters, ovarian histology and gene expression levels between intersex and normal Eriocheir sinensis (Decapoda, Varunidae)
Authors: Lu Wentao , Aamoum Oussama , Feng Tianyi , Mo Nan , Han Rui , Shao Shucheng , Cui Zhaoxia 
Published: September 2024

Abstract
This study explores the primary characteristics of intersexuality in Eriocheir sinensis in aquacultural environments. We employed a variety of research methods, including morphological observations, histological analysis, transcriptome analysis, and 3D reconstruction techniques, to comprehensively examine the phenomenon of intersexuality in this species. Our findings indicate that most intersex E. sinensis in aquaculture may be genetically female crabs undergoing masculinization processes. These crabs exhibit a combination of both external and internal sexual characteristics, with the extent of intersexuality varying among individuals. While these intersex crabs may engage in normal mating behaviour, the structures of their abnormal internal reproductive system may impede proper fertilization, ovulation, or egg production. Additionally, we found that the androgenic gland (AG) in intersex crabs did not inhibit ovarian development. Our study provides insights into the potential mechanisms underlying intersex occurrence in E. sinensis and contributes to the improvement of aquaculture practices, a reduction in the incidence of intersex crabs, and the safeguarding of consumer health.
A new species of Pseudodiaptomus (Copepoda, Calanoida, Pseudodiaptomidae) from the coastal waters of northern Taiwan with notes on co-occurring and previously recorded species
Authors: Nishida Shuhei , Machida Ryuji , Hwang Jiang-Shiou 
Published: September 2024

Abstract
We investigated the species diversity of the demersal copepod genus Pseudodiaptomus in the coastal waters of northern Taiwan, and recorded four species new to Taiwanese waters: P. echinatus n. sp., P. ishigakiensis Nishida, 1985, P. philippinensis Walter, 1986, and P. zhengi Wang & Guo, 2019. Pseudodiaptomus echinatus n. sp. is distinguished from the allied species P. serricaudatus (Scott T., 1894) by the female genital double-somite, which is laterally swollen and of subequal length and width, and the male fifth leg, the right endopod of which is oval with a row of spinules increasing in size toward the tip, and the first exopod segment of which has a distomedial digitiform process with rounded tip. In addition, out of the 11 nominal species previously recorded from Taiwanese waters, we found only three species (P. annandalei Sewell, 1919, P. bispinosus Walter, 1984, P. trihamatus Wright, 1937). We were unable to confirm the presence of P. forbesi (Poppe & Richard, 1890), P. incisus Shen & Lee, 1963, P. inopinus Burckhardt, 1913, P. marinus Sato, 1913, P. pacificus Walter, 1986, P. penicillus Li & Huang, 1984, P. poplesia (Shen, 1955), and P. serricaudatus (T. Scott, 1894) by a critical review of available literature based on morphology, locality, habitat, etc. In this regard, it is necessary for a future study to try to verify the presence of these eight species in Taiwanese waters.
Nutrient absorption and storage roles of hepatopancreas, gills, and muscles during moulting in Macrobrachium nipponense (Decapoda, Caridea, Palaemonidae): insights into phosphorus, calcium, and magnesium dynamics
Authors: Zheng Xirui , Zhao Weihong , Zhang Honglei , Liu Xingyu , Zhang Yuxia , Mao Airong , Gao Zhigang 
Published: September 2024

Abstract
Phosphorus, calcium, and magnesium are pivotal elements in the exoskeleton of crustaceans, playing a crucial role in the moulting stages. As crustaceans cannot synthesize these nutrients, their acquisition relies on external sources, with tissues such as the hepatopancreas and gills actively participating in this process. Studying changes in phosphorus, calcium, and magnesium concentrations in these tissues is essential for a comprehensive understanding of their role in nutrient absorption during the moulting stages. The hepatopancreas, gills, muscles, and carapace of Macrobrachium nipponense (De Haan, 1849) were taken from the premoult, postmoult, and intermoult stages to study the changes in phosphorus, calcium and magnesium contents in the hepatopancreas, gills, muscles, and carapace during the moulting process of M. nipponense. Three parallel experiments were measured in each stage, and 10-20 prawns were mixed for each stage. Phosphorus content per tissue unit weight was measured using the vanadium-molybdenum yellow colorimetric method, and calcium and magnesium content per unit weight of tissue were measured using atomic absorption spectrophotometry. Phosphorus in the hepatopancreas and gills increased significantly from the premoult stage to the postmoult stage (), and magnesium also showed the same trend. Calcium in the hepatopancreas was significantly highest in the premoult phase, whereas phosphorus was significantly highest in the postmoult stage (). The hepatopancreas Ca/P ratio decreased significantly before and after moulting, while it increased significantly in the gills (). The results show that the hepatopancreas and gills are the main tissues that absorb phosphorus, calcium, and magnesium. The hepatopancreas absorbs and stores calcium earlier than phosphorus. The changes in the Ca/P ratio of the hepatopancreas and gills found that M. nipponense consumes more phosphorus than calcium during moulting and growth, and the gills have a better ability to absorb calcium than phosphorus.
Phylogenetic placement of the Neotropical endemic genus Hydrodessus J. Balfour-Browne, 1953 (Coleoptera: Dytiscidae) based on larval morphology
Authors: Benetti Cesar J. , Michat Mariano C. , Alarie Yves , Hamada Neusa 
Published: September 2024

Abstract
The phylogenetic relationships of members of the hydroporine tribe Bidessini (and particularly of the Neotropical endemic genus Hydrodessus J. Balfour-Browne, 1953) are investigated based on a cladistic analysis of larval characteristics, including 26 Hydroporinae species in 25 genera. For this purpose, the larvae of Hydrodessus latotibialis Miller, 2016 are described for the first time including detailed morphometric and chaetotaxic analyses of the cephalic capsule, head appendages, legs, last abdominal segment and urogomphi. Larval morphology supports a monophyletic origin of the Bidessini based on the absence of the primary pore ABc, a unique feature within Hydroporinae. Hydrodessus was recovered as sister to other Bidessini studied, being characterized by several unique character states. This result supports a previous hypothesis of a basal position of this genus within Bidessini based on adult characters. The presence of natatory setae on femur, tibia and tarsus could represent an adaption to life in lotic environments.
The Role of Parliament in Times of Constitutional Crisis – The Case Study of Poland
Authors: Milczarek Ewa 
Published: September 2024

Abstract
The article analyses the role of parliament in the face of a constitutional crisis, drawing on Poland’s experience from 2015–2023. The issue discussed focuses on the impact of changes to the judiciary and other key democratic institutions, which have resulted in Poland being perceived as a state with illiberal constitutionalism or authoritarian populism. The article emphasises the importance of analysing patterns and scenarios of constitutional crisis, pointing to the ‘avalanche effect’ whereby changes in one country can affect other countries in the region. The paper focuses on the role of the parliament as a key democratic body responding to difficult challenges and attempts to curb violations of the rule of law in Poland. The research objective is to analyse the constitutional mechanisms conducive to the protection of the rule of law during periods of populist rule, and by analysing these aspects, the paper contributes to the debate on the condition of contemporary parliamentarism.
Economic Growth and Stable Employment in the West African Economic and Monetary Union
Authors: Sangare Vassy Pierre , Kouakou Kouadio Clément , Djezou Wadjamsse Beaudelaire , Ble Caroline 
Published: September 2024

This article explores the impact of the institutional environment on the ability of economic growth to generate stable employment in West African Economic and Monetary Union (WAEMU) countries. Using an autoregressive distributed lag (ARDL) model on panel data from 1996 to 2021, we find a positive correlation between economic growth and stable employment in the short and long term. Services and industry are the primary sources of stable jobs in the long run. Furthermore, institutional factors speed up employment adjustment to equilibrium during economic shocks. Specifically, controlling corruption, government efficiency and regulation quality enhance economic growth’s impact on stable job creation. Therefore, pursuing a structural transformation of the WAEMU’s economies and enhancing the institutional environment is imperative to ensure job stability. JEL Codes: C23, E24, J2, O55