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On the effect of pitch and yaw angles in oblique impacts of smallcaliber projectiles

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Defence Technology（防务技术） 2024年第1期31卷 73-94页

作者： Teresa Fras French-German Research Institute of saint-Louis(ISL) Saint-LouisFrance

A terminal ballistic analysis of the effects of 7.62 mm × 51 AP P80 rounds on inclined high-strength armor steel plates is the focus of the presented *** findings of an instrumented ballistic testing combined with 3D advanced numerical simulations performed using the IMPETUS Afea? software yielded the *** experimental verification proved that slight differences in the pitch-andyaw angles of a projectile upon an impact caused different damage types to the projectile’s *** residual velocities predicted numerically were close to the experimental values and the calculated core deviations were in satisfactory agreement with the experimental *** extended matrix of the core deviation angles with combinations of pitch-and-yaw upon impact angles was subsequently built on the basis of the numerical *** presented experimental and numerical investigation examined thoroughly the influence of the initial pitch and yaw angles on the after-perforation projectile’s performance.

关键词： Ballistic impact Small-caliber projectile Pitch and yaw impact angles Shadowgraphy IMPETUS Afea Numerical simulations

Seasonal changes in hermit Thrush (Catharus guttatus) song syntax

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Avian Research 2024年第2期15卷 172-179页

作者： Sean P.Roach Luke C.McLean Jeff W.MacLeod Leslie S.Phillmore Psychology Department University of New Brunswick Saint John100 Tucker Park RoadSaint JohnNBCanada Department of Psychology and Neuroscience Dalhousie University1355 Oxford StHalifaxNSB3H 4J1Canada

In many songbird species,birdsong features phonological syntax,meaning that the units within their vocal se-quences are ordered in a non-random way that adheres to a *** such syntactical patterns have been richly described in many species,comparatively little is known about how those patterns contribute to song achieving its important *** each of song’s main functions,territorial defense and mate attraction,evidence of a role for syntax is *** species for which syntax has been thoroughly described is the hermit Thrush(Catharus guttatus),which presents song types from their repertoires in a semi-predictable order and,in doing so,rapidly cycle up and down the frequency *** objective of the present study was to explore the importance of song syntax in the hermit Thrush through a within-subject examination of how measures of syntax,such as the predictability of song type order within song sequences,shift over the breeding *** hypothesized that,if such syntactical characteristics are important to breeding behaviour,they would be most prominent at the start of the breeding season when activity associated with territory establishment and mate attraction is most *** revealed that,as predicted,the rigidness of song type ordering within se-quences was highest at the start of the season and declined *** song type sequences were most predictable at the vitally important early part of the breeding season fit our hypothesis that this aspect of song syntax is important to song’s functions related to territory establishment and/or mate *** work will clarify whether that role relates to one of song’s two main functions or serves song transmission in some broader way.

关键词： Birdsong hermit Thrush Seasonal change Stereotypy Syntax

Strong Subgame Consistency of the Core in Stochastic Network Formation Games

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Journal of the Operations Research Society of China 2024年第1期12卷 189-213页

作者： Ping Sun Elena Parilina Faculty of Applied Mathematics and Control Processes Saint Petersburg State UniversitySaint Petersburg199034Russia

We consider a model of network formation as a stochastic game with random duration proposed initially in Sun and Parilina(Autom Remote Control 82(6):1065–1082,2021).In the model,the leader first suggests a joint project to other players,i.e.,the network connecting ***,the players are allowed to form fresh links with each other updating the initially proposed *** stage payoff of any player is defined depending on the network *** are two types of randomness in the network formation process:(i)links may fail to be formed with different probabilities although players intend to establish them,(ii)the game process may terminate at any stage or transit to the next stage with a certain probability ***,a network is formed as a result of players’decisions and realization of random *** cooperative version of the stochastic game is *** particular,we examine the properties of subgame consistency as well as strong subgame consistency of the *** provide a payment mechanism or regularization of the core elements to sustain its subgame consistency and avoid the player’s deviations from the cooperative *** addition,the distribution procedure of the core elements is regularized in case there are negative payments to achieve only nonnegative payments to the players at any *** sufficient condition of a strongly subgame consistent core is also *** illustrate our theoretical results with a numerical example.

关键词： Stochastic game Network formation Core Strong subgame consistency

Opinion Dynamics in Two-Layer Networks with hypocrisy

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Journal of the Operations Research Society of China 2024年第1期12卷 109-132页

作者： Chi Zhao Elena Parilina saint Petersburg State University Saint Petersburg199034Russia Qingdao University School of Mathematics and StatisticsQingdao 266071ShandongChina

We propose a general concealed voter model(GCVM),in which individuals interact in two layers and can exchange their opinions in the internal *** interaction is not allowed in a *** exchanging opinions in the internal layer,we mean that individuals share their real or internal opinions with their close *** process of opinion formation in GCVM is presented in the *** make the series of numerical simulations of GCVM with different network structures(both external and internal)and get some counterintuitive *** instance,we find out that sometimes with a relatively simple network structure of an external layer the consensus within the individuals’opinions cannot be reached,and if individuals in the network are not good at expressing their opinions publicly(in an external layer),exchanging opinions with their close friends(in an internal layer)is almost useless.

关键词： Opinion dynamics Voter model Concealed voter model General concealed voter model

Competitive Resource Allocation Among Urban Congestion Areas in a Modern Big City

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Journal of the Operations Research Society of China 2024年第1期12卷 133-153页

作者： Alexander Krylatov Anastasiya Raevskaya Institute of Applied Mathematical Research of the Karelian Research Centre of the Russian Academy of Sciences Petrozavodsk185910Russia saint Petersburg State University Saint Petersburg199034Russia

The continuing growth of modern big cities leads to their spatial expansion and the emergence of new road connections and urban *** where large transportation flows of pedestrians,passengers,and drivers come together create demand points,which attract business companies that strive to allocate their resources in the most sought-after ***,the law of supply and demand restrains companies from allocating all their resources solely in the most popular congestion areas since the more valuable an urban area,the higher the cost to be paid for a resource unit allocation *** a result,companies act in a non-cooperative manner and try to minimize their own overall costs when allocating resources across available commercial areas in a big ***-cooperative behavior of companies leads to the problem of Nash equilibrium search in the game of competing *** this paper,we study the corresponding resource allocation game under affine cost functions and obtain Nash equilibrium strategies in explicit *** findings allow us to develop a simple procedure for computing Nash equilibria in the game of companies allocating their resources among urban congestion *** computational study demonstrates the dependence of the average price for resource allocation on the number of players and their resource *** outcome of the paper contributes to flow theory and seems to be fresh and useful for managers.

关键词： Resource allocation Nash equilibrium Affine costs

Utilizing Iso-Value Field Curves in Lieu of Magnetic Field Lines Amid Infinite and Parallel Electrical Wires

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Open Journal of Applied Sciences 2024年第1期14卷 70-84页

作者： Geoffroy Auvert INPG Grenoble Alpes University Saint Martin d’Hères France

Building on a new model proposed recently for calculating constant electro-magnetic field values, the present article explores the electro-magnetic field configuration generated by parallel electrical wires. This imposes a reevaluation of the drawing procedure for constructing field curves with a constant field values around multiple parallel electrical conducting wires. To achieve this, we employ methods akin to those used for creating contours on topographical maps, ensuring a consistent numerical field value along the entire length of the field curves. Subsequent calculations will be conducted for scenarios where wires are not parallel.

关键词： Specific Field Value Parallel Electrical Wires Magnetic Field Vector Field around Parallel Wires Topographic Level Map

COVID-19/Tuberculosis Co-Infection at the Epidemic Treatment Center (ETC) of saint-Louis (Senegal): About 9 Cases

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Advances in Infectious Diseases 2024年第1期14卷 56-66页

作者： Alassane Dièye Moustapha Diedhiou Papa Latyr Junior Diouf Mba Bambo Diakhaby Demba Makalou Samba Niang Diatou Dia-Gueye Amadou Diop Dia Ibrahima Louis Martin Dieng Seynabou Lô Ndéye Méry Dia-Badiane health Sciences Training and Research Unit Gaston Berger University Saint-Louis Senegal Department of Medicine Saint-Louis Regional Hospital Saint-Louis Senegal Infectious and Tropical Diseases Clinic of Fann Dakar Senegal

Introduction: COVID-19 is a global public health emergency that can cause acute respiratory distress syndrome. In countries where tuberculosis (TB) is endemic, coinfection of COVID-19 and TB is often encountered, which increases the risk of developing severe forms of COVID-19. Objectives: The aim of this study was to determine the prevalence of COVID-19/TB coinfection at the Epidemic treatment center (ETC) in saint-Louis (Senegal) and to describe the epidemiological, clinical, paraclinical, and outcome profile of co-infected patients. Patients and Methods: This is a retrospective, cross-sectional, descriptive cohort study based on the records of COVID-19/ TB co-infected patients who were hospitalized at the ETC in saint-Louis (Senegal) over an 18-month period from March 2020 to September 2021. Results: Out of a total of 454 hospitalizations, we collected records of 9 patients co-infected with COVID-19/TB, resulting in a prevalence of 2%. The study included patients with a median age of 34 years (range: 10-86 years), with a male predominance (7 cases) and a sex ratio of 3.5. The majority of patients (88.9%) had severe forms of COVID-19. Dyspnea and cough were reported in all patients (100%). Pulmonary TB was the most frequent localization, with 9 cases. The diagnosis of COVID-19 was confirmed by nasopharyngeal PCR in all patients (100%). Bacilloscopy was positive in 3 out of 5 cases. One patient tested positive for GeneXpert? MTB/RIF without rifampicin resistance. All patients were prescribed the hydroxychloroquine-azithromycin combination and anti-tuberculosis treatment. Out of the nine patients, four recovered (44.4%) and five died (55.5%). Conclusion: COVID-19/TB coinfection had a low prevalence in our cohort, but was associated with a high mortality due to the frequent occurrence of severe forms of the disease.

关键词： COVID-19 Tuberculosis saint-Louis Senegal

Performance of a horizontal Flow Constructed Reed Bed Filter for Municipal Wastewater Treatment: The Case Study of the Prototype Installed at Gaston Berger University, saint-Louis, Senegal

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Natural Resources 2024年第1期15卷 1-16页

作者： Abdou Khafor Ndiaye Falilou Coundoul Abdoulaye Deme Antonina Torrens Armengol Abdoulaye Senghor UFR of Applied Sciences and Technology Gaston Berger University of Senegal Saint-Louis Senegal Polytechnic Institute of saint-Louis (IPSL) Gaston Berger University of Saint-Louis Saint-Louis Senegal Department of Biology Healthcare and Environment Faculty of Pharmacy and Food Sciences University of Barcelona Barcelona Spain Sanitation Department Ministry in Charge of Sanitation Dakar Senegal

In saint-Louis, Senegal, a constructed wetland with horizontal flow reed beds (Fha and Fhb) has demonstrated significant efficacy in treating municipal wastewater. Analyzing various treatment stages, the system showed only a slight temperature variation, from an influent average of 26.3°C to an effluent of 24.7°C. Electrical conductivity decreased from 1331 mS/cm to 974.5 mS/cm post-primary treatment, with suspended solids (SS) dramatically reduced from 718.9 mg/L to 5.7 mg/L in the final effluent. Biochemical oxygen demand (BOD5) and chemical oxygen demand (COD) saw a notable decrease, from initial levels of 655.6 mg/L and 1240 mg/L to 2.3 mg/L and 71.3 mg/L, respectively. Nitrogenous compounds (N-TN) and phosphates () also decreased significantly, indicating the system’s nutrient removal capacity. Microbiological analysis revealed a reduction in fecal coliforms from 7.5 Ulog/100ml to 1.8 Ulog/100ml and a complete elimination of helminth eggs. The presence of Phragmites and Typha was instrumental in enhancing these reductions. The system’s compliance with the Senegalese standards for disposal into natural environments, WhO recommendations for unrestricted water reuse in irrigation, and the European legislation for water reuse was established. The effluent quality met the stringent criteria for various classes of agricultural reuse, illustrating the system’s potential for sustainable water management. This wetland model presents a robust solution for water-stressed regions, ensuring environmental protection while supporting agricultural needs. The study calls for ongoing research to further refine the system for optimal, reliable wastewater treatment and water resource sustainability.

关键词： Constructed Wetlands horizontal Flow Reed Beds Wastewater Treatment Phragmites and Typha Plants Physicochemical Pollutant Removal Microbiological Indicators Fecal Coliforms and helminth Eggs Water Quality Improvement Senegal Water Reuse Standards Sustainable Water Management Agricultural Irrigation Reuse Nutrient Removal Efficiency Environmental Engineering Ecological Sanitation Systems

Ion-conducting Membranes Based on Bacterial Cellulose Nanofibers Modified by Poly(sodium acrylate-co-2-acrylamido-2-methylpropanesulfonic acid)

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Chinese Journal of Polymer Science 2024年第3期42卷 333-343,I0007页

作者： Elizaveta V.Batishcheva Nikolay N.Smirnov Natalya V.Bobrova Maria P.Sokolova Michael A.Smirnov Institute of Macromolecular Compounds Russian Academy of SciencesBolshoy pr.31Saint Petersburg 199004Russia

Green method for preparation of ion-conducting membranes(ICM) based on bacterial cellulose nanofibers(CNF) modified by a copolymer of sodium acrylate and 2-acrylamido-2-methylpropanesulfonic acid was elaborated. FTIR and NMR data confirmed grafting of polyacrylate onto cellulose surface. Formation of porous structure of the ICM was controlled by SEM and AFM. The maximal ionic conductivity of the membranes reaches 1.5 and 3.1 mS·cm^(-1)(60 ℃ and 98% relative humidity) when they are saturated with water or h_2SO_4(1 mol·L^(-1)) electrolyte,respectively. Prepared ICM was tested as a separator in a symmetrical supercapacitor with electrodes based on polyaniline hydrogel. The assembled cell demonstrate ability to operate at high current density up to 100 A·g^(-1) maintaining specific capacitance 165 F·g^(-1). Maximal specific capacitance of 289 F·g^(-1) was achieved at current density 1 A·g^(-1). Retaining of 90% of initial capacitance after 10000 of charge-discharge cycles proves high electrochemical stability of prepared ICM.

关键词： Bacterial cellulose Ion conductivity Porous membrane Supercapacitor