bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization and impact of planthopper (Sanurus indecora) infestation on kepel (Stelechocarpus burahol) plants
Authors: Saputra Yudha , Anindita Devina Cinantya , Hadiyanti Nugraheni , Supandji Supandji , Hapsari Lia
Published: December 2024

Kepel (Stelechocarpus burahol), designated as the floral identity of the Special Region of Yogyakarta, Indonesia, faces challenges from plant pests that threaten its sustainability. Understanding the morphology and impact of pests such as planthoppers on kepel is crucial for developing effective pest management strategies. Despite its significance, there is a gap in research regarding the specific pests affecting kepel and their impact. This study aims to identify the morphological characteristics of planthopper pests and examine their infestation levels on kepel plants. Using a qualitative method with purposive sampling, samples were collected from kepel plants identified as infected by tree planthoppers. Morphological observations identified the pest species as Sanurus indecora from the Flatidae family. Sampling from two infected plants resulted in 81 nymphs and 16 adult S. indecora. Infestation analysis showed that kepel plant XII.G.D had a 7.4% infestation rate, while XIV.G.II had a 23% infestation rate. These findings highlight the presence and impact of S. indecora on kepel plants, providing critical information for the bioecology of this pest. This study not only fills a research gap by documenting the pests affecting kepel but also contributes to the broader knowledge required for developing targeted pest management strategies, ensuring the conservation and health of kepel plants in Yogyakarta, Indonesia.
SOCIAL WORK-LED COUNSELING STRATEGIES WITH LINGUISTIC APPROACHES FOR SUICIDE PREVENTION IN MARGINALIZED COMMUNITIES
Authors: Yudistira Satria
Published: December 2024

Counseling interventions coordinated by social work are essential for suicide prevention in underprivileged groups. Linguistic methodologies in counseling promote effective communication, improve comprehension, and foster trust between social workers and vulnerable children. This study examines optimal practices for applying counseling strategies that incorporate linguistic sensitivity among two underrepresented communities. The results indicate that this method effectively enhanced children's emotional regulation (80%), self-confidence (75%), and the formation of healthy interpersonal relationships (85%). Nonetheless, obstacles such as stigma associated with mental health care, parental opposition, and resource limitations persist as considerable impediments. Recommendations encompass training social workers in linguistically inclusive communication techniques, enhancing cross-sector policy support, and utilizing technology to broaden program outreach. This study emphasizes that incorporating language and cultural methodologies into social work counseling can effectively mitigate suicide risk in marginalized areas, ensuring communication is socially and culturally pertinent while promoting trust and engagement.
Analysis of the floristic composition of steppe communities of the Caucasian Mineral Waters Region
Authors: Shchukina K. V. , Lysenko T. M. , Shilnikov D. S. , Neshataeva V. Yu. , Kessel D. S. , Liksakova N. S. , Neshataev M. V.
Published: December 2024

A comprehensive analysis of the species composition of the steppe communities of the laccolith mountains of the Caucasus Mineral Waters region (CMW), as well as of Jinal and Borgustan ridges in the vicinity of Kislovodsk was carried out. The research area is located in the Fore-Caucasus, in the south of the Stavropol Territory, and is characterized by a high diversity of steppe-type vegetation communities. The list of the flora of the CMW steppes is based on 294 relevés of steppe vegetation, and comprises 633 vascular plant species belonging to 278 genera and 66 families, which is 28.7% of the flora of the Upper Kuma floristic region. The composition and proportions of the family and generic spectra of the studied communities characterize their floristic composition as predominantly boreal, with several features characteristic of Mediterranean floras. In the composition of the steppe communities of the study area, the leading role belongs to a group of species of boreal range types with the dominance of the Caucasian geographic element. According to the ecological-cenogenetic spectrum, the species composition of the communities of the studied steppes can be characterized as meadow-steppe, with equally represented steppe and meadow components of flora. The main dominants of the steppe communities of the CMW are cespitose grasses, with a large share of rhizomatous polycarpic herbs and tap-rooted polycarpics and monocarpics in the floristic composition. In the studied communities, six endemics of the North Caucasus and three endemics of the Fore-Caucasus were recorded. The results of the complex analysis emphasize the heterogeneity and mountain-steppe nature of the floristic composition of the studied vegetation, caused by its geographical location, a combination of a complex set of conditions (relief, parent rocks, soils, etc.), florogenesis and the history of anthropogenic impact.
Intercellular communications in Chaetopteris plumosa (Sphacelariales, Phaeophyceae)
Authors: Kudryavtseva E. O.
Published: December 2024

This article provides information about the ultrastructure of intercellular communications in Chaetopteris plumosa. The structure and variants of plasmodesmata localization in its cells are described, data on the distances between plasmodesmata and the density of their location in cell walls are provided. In C. plumosa, both independent plasmodesmata and cell wall areas with multiple closely spaced plasmodesmata were found. Such localization of intercellular connections may represent a transitional variant between independent plasmodesmata and pit fields or another variant of plasmodesmata organization previously not described in brown algae. The arrangement of plasmodesmata in Sphacelariaceae is discussed.
The plasmodesmata in C. plumosa have a structure typical of brown algae. In the longitudinal walls of the medulla, there are independent plasmodesmata, the distance between which on sections is (268 ± 147) nm (mean ± SD, n = 255). In the longitudinal and transverse walls of corticating rhizoids, plasmodesmata are often located much more densely and evenly, the distance between them is (90 ± 29) nm (n = 2863), and there are 39 ± 4 (n = 54) plasmodesmata per 1 μm2. It is advisable to classify this variant of localization of plasmodesmata as pit fields or transitional variant between independent plasmodesmata and pit fields.
Species of vascular plants new for the flora of Sakhalin Island
Authors: Sabirova N. D. , Sabirov R. N.
Published: December 2024

The information is given on 8 species of vascular plants new for the flora of Sakhalin Island: Arthraxon langsdorffii (Trin.) Hochst., Carex neurocarpa Maxim., Clematis serratifolia Rehder, Digitaria ischaemum (Schreb.) H.L. Muehl., Dracocephalum charkeviczii Prob., Eriochloa villosa (Thunb.) Kunth, Geranium maximowiczii Regel et Maack., and Sisyrinchium septentrionale E.P. Bicknell. The localities of the newly found species are indicated, brief data on their geographical distribution and growing conditions are presented.
Boris Nikolaevich Golovkin (1934–2011): botanist, floriculturist and popularizer of sciencE
Authors: Borovichev E. A. , Viracheva L. L. , Kolomeitseva G. L.
Published: December 2024

The article is devoted to the 90th anniversary of the outstanding Russian botanist, professor, doctor of biological sciences Boris Nikolaevich Golovkin. The main milestones of his biography, an overview of scientific and science-popularizing activities are presented. The article is based on the analysis of published works of the scientist, personal memories and archival materials.
Selective Synthesis of Amino Acid Conjugates of Glycyrrhizic Acid Using N-Oxyphthalimide and N,N′-Dicyclohexylcarbodiimide
Authors: Fairushina A. I. , Petrova S. F. , Baltina L. A.
Published: December 2024

A selective synthesis of amino acid conjugates of glycyrrhizic acid containing amino acid residues in the carbohydrate part of the glycoside was proposed using N-oxyphthalimide (HOPt) and N,N′-dicyclohexylcarbodiimide (DCC), tert-butyl and benzyl/4-nitrobenzyl esters of L-amino acids with yields of 55–60%. Free conjugates of glycyrrhizic acid with valine, isoleucine, methionine, phenylalanine, leucine, tyrosine and glutamic acid were obtained by deblocking the ester groups.
Analysis of ADHD Students' Adversity Quotient and Understanding of Mathematical Concepts
Authors: MZ Zubaidah Amir , Nurhasnawati Nurhasnawati , Hamdani M. Fikri , Jannah Nurul
Published: December 2024

Pembelajaran matematika seringkali dianggap sulit termasuk bagi siswa ADHD. Penelitian ini bertujuan untuk menganalisis antara daya juang (adversity Quotient) siswa ADHD pemahaman konsep matematikanya. Penelitian ini bersifat deskriptif kualitatif dengan studi kasus pada siswa ADHD. Subyek penelitian ini adalah 3 siswa dari tiga SLB di Kota Pekanbaru. Instrumen penelitian ini berupa angket, lembar observasi, dan wawancara. Teknik analisis data dengan menggunakan deskriptif dan triagulasi. Hasil Penelitian: Daya juang siswa ADHD berbeda-beda, tergantung pada tingkat ADHD dan usianya. Rata-rata tingkat Adversity Quotient (AQ) siswa ADHD dalam pembelajaran matematika berada pada kategori sedang. Pemahaman konsep matematika siswa ADHD berada pada kategori sedang. Faktor yang mempengaruhi kemampuannya adalah siswa sering melupakan materi atau konsep sebelumnya. Upaya yang dilakukan guru untuk meningkatkan pemahaman konsep matematika adalah dengan memperbanyak penggunaan media pembelajaran visual, baik 3D maupun 2D, dan belajar dengan cara permainan. Oleh karena itu guru diharapkan menggunakan media visual dalam pembelajaran matematika pada siswa ADHD.
This research aims to describe mathematics teachers' perceptions of geometry concepts Learning mathematics is often considered difficult, including for ADHD students. This study aims to analyze ADHD students' adversity Quotient and their understanding of mathematical concepts. This research is descriptive qualitative with a case study of ADHD students. The subjects of this research were 3 students from three special schools in Pekanbaru City. The instruments for this research are questionnaires, observation sheets and interviews. Data analysis technique using descriptive dan triangulation. Research Results: The fighting power of ADHD students varies, depending on the level of ADHD and age. The average Adversity Quotient (AQ) level of ADHD students in learning mathematics is in the medium category. ADHD students' understanding of mathematical concepts is in the medium category. A factor that influences their ability is that students often forget previous material or concepts. Efforts made by teachers to increase understanding of mathematical concepts are by increasing the use of visual learning media, both 3D and 2D, and learning through games. Therefore, teachers are expected to use visual media in teaching mathematics to ADHD students.
Application of Positive and Negative Board Based on Montessori Method on Junior High School Students' Mathematical Connection Abilities
Authors: Susiaty Utin Desy , Firdaus Muhamad
Published: December 2024

Tujuan dari penelitian ini adalah untuk mengetahui seberapa baik aplikasi papan positif negatif berbasis metode Montessori terhadap kemampuan koneksi matematis siswa SMP. Subjek penelitian adalah siswa di kelas VII SMP. Data dikumpulkan menggunakan teknik pengukuran dan teknik komunikasi tidak langsung. Soal tes kemampuan adalah alat pengumpul data. Berdasarkan hasil pengembangan, penelitian, dan diskusi tentang penggunaan papan positif negatif berbasis metode Montessori terhadap kemampuan koneksi matematis siswa SMP, dapat disimpulkan bahwa pengembangannya mencapai tingkat kelayakan yang sesuai dengan kriteria validitas, praktisitas, dan efektifitas.
The aim of this research is to find out how well the positive and negative board application based on the Montessori method affects junior high school students' mathematical connection abilities. The research subjects were students in class VII of junior high school. Data was collected using measurement techniques and indirect communication techniques. Ability test questions are a data collection tool. Based on the results of development, research and discussions regarding the use of positive and negative boards based on the Montessori method on junior high school students' mathematical connection abilities, it can be concluded that the development has reached a level of feasibility that is in accordance with the criteria of validity, practicality and effectiveness.
Yükseköğretim ve Uluslararası Perspektiften Matematik Öğretmenlerinin Öğretim Uygulamaları: TALIS 2018 Örneği
Authors: Erol Ramazan , Kaya Gürcan , Koyuncu Mahmut Sami
Published: December 2024

Yükseköğretim kademesindeki öğretmen yetiştirme sürecinin iyileştirilebilmesi için mevcut öğretmenlerin uygulamalarının incelenmesi önem arz etmektedir. Bu çalışmanın amacı, Uluslararası Öğretme ve Öğrenme Anketi (Teaching and Learning International Survey [TALIS]) 2018 Türkiye örnekleminde yer alan ortaokul ve lise matematik öğretmenlerinin sınıfta kullandıkları öğretim uygulamalarını incelemektir. Araştırmanın çalışma grubunu, TALIS 2018 Türkiye örnekleminde yer alan toplam 1399 matematik öğretmeni oluşturmaktadır. Lise ve ortaokul matematik öğretmenlerinin öğretim uygulamaları puanları karşılaştırıldığında, ortaokul öğretmenleri lehine anlamlı bir farklılık bulunmuştur. Ortaokul ve lise matematik öğretmenlerinin öğretimin anlaşılırlığı puanları arasında anlamlı bir farklılık bulunmamakla birlikte, bilişsel etkinlikler ve sınıf yönetiminde ortaokul öğretmenleri lehine anlamlı bir farklılık bulunmuştur. Zenginleştirilmiş etkinliklerde ise, ortaokul öğretmenlerinin oransal olarak bilgi iletişim teknolojilerini daha sık kullandıkları tespit edilmiştir. Bu bağlamda her iki kademedeki öğretmenler tarafından sınıflarda daha fazla kullanılması için yükseköğretim ders içeriklerinde bilişsel etkinliklerin ve zenginleştirilmiş etkinliklerin kullanımına daha fazla yer verilmesi önerilmektedir.
Yükseköğretimde Kalite
Authors: Yeşilbaş Özenç Yasemin
Published: December 2024

Kalite, bir mal ya da hizmetin, bireylerin ya da örgütlerin ihtiyaçlarını ve beklentilerini karşılayabilecek düzeyde olması olarak tanımlanabilir. Yükseköğretimde kalite ise yükseköğretim kurumlarında görev yapan öğretim elemanlarının profesyonelliğini ve öğrencilerin öğrenme kabiliyetini artıran, çağın gerekliliklerini karşılamaya yönelik yerine getirilmesi gereken niteliklerdir. Bu çalışmada, yükseköğretimde kalitenin temel bileşenleri ve bu bileşenlerin kurumlar üzerindeki etkileri nitel araştırma yöntemlerinden doküman analizi yöntemiyle alanyazındaki çalışmalardan derlenerek sunulmuştur. Araştırma kapsamında, yükseköğretimde kalite, dört kavram çerçevesinde incelenmiştir. Bunlar; kalite güvencesi, toplam kalite yönetimi, hesap verebilirlik ve akreditasyondur. Araştırmada bu dört kavrama ilişkin literatürdeki en güncel ve nitelikli çalışmalar ele alınarak, yükseköğretimde kalite yönetimine dair kapsamlı bir çerçeve sunmak amaçlanmıştır. Kalite güvencesi, yükseköğretim kurumlarının sundukları eğitimin belirlenen standartları karşıladığını ve sürekli iyileştirildiğini güvence altına almak amacıyla uygulanan süreçlerdir. Toplam Kalite Yönetimi, bir örgütün tüm süreçlerinde kaliteyi sürekli iyileştirmeyi hedefleyen yönetim yaklaşımıdır. Hesap verebilirlik, yükseköğretim kurumlarının, sundukları eğitim hizmetleri ve kullandıkları kaynaklar konusunda paydaşlarına ve topluma karşı sorumluluk taşıyarak şeffaf ve denetlenebilir olmalarını ifade ederken; akreditasyon, bir yükseköğretim programının veya kurumunun, belirlenen kalite standartlarına uygun olduğunu resmi olarak doğrulayan dış değerlendirme süreci olarak tanımlanabilir. Yükseköğretimde kaliteye ilişkin kavramların ele alındığı bu çalışmanın, başta yükseköğretim yöneticileri olmak üzere, öğretim elemanlarına ve araştırmacılara katkı sağlaması beklenmektedir.
Asymptotic bounds on the number of the eigenvalues in the gaps of the 2D magnetic Schrödinger operator
Authors: Raikov G.D.
Published: December 2024

We consider the two‐dimensional Schrödinger operator with generically bounded magnetic field, perturbed by a scalar potential $-gV$ , $g \geq 0$ being the coupling constant. We assume that $V$ is non‐negative and decays rapidly at infinity (e.g., $V({\mathbf x})\asymp \vert{\mathbf x}\vert^{-\alpha}$ , $\alpha > 2$ , as $\vert{\mathbf x}\vert\rightarrow \infty$ ). We examine the asymptotic behaviour as $g \rightarrow \infty$ of the eigenvalues situated in the gaps of the spectrum of the unperturbed operator.
Asymptotics of arbitrary order for a thin elastic clamped plate, II. Analysis of the boundary layer terms
Authors: Dauge Monique , Gruais Isabelle
Published: December 2024

This paper is the last of a series of two, where we study the asymptotics of the displacement in a thin clamped plate as its thickness tends to $0$ . In Part I, relying on the structure at infinity of the solutions of certain model problems posed on unbounded domains, we proved that the combination of a polynomial Ansatz (outer expansion) and of a boundary layer Ansatz (inner expansion) yields a complete multi‐scale asymptotics of the displacement and optimal estimates in energy norm. The “profiles” for the boundary layer terms are solutions of such model problems. In this paper, adapting Saint‐Venant’s principle to our framework, we prove the results which we used in Part I.

Investigating more precisely the structure of the boundary layer terms, we go further in the analysis performed in Part I: the introduction of edge layer terms along the intersections of the clamped face with the top and the bottom of the plate, respectively, allows estimates in higher order norms. These edge layer terms are constructed with the help of stable asymptotics, and are the singular parts of the boundary layer terms. As a by‐product of all these investigations, we obtain expansions and estimates for the stress tensor in various anisotropic norms, and also estimates in $L^\infty$ ‐norm for the displacement field.
Bellman–Isaacs equations of ergodic type related to risk‐sensitive control and their singular limits
Authors: Kaise Hidehiro , Nagai Hideo
Published: December 2024

Bellman–Isaacs equation of ergodic type is studied in paricular case. A solution of the equation related to the principal eigenfunction of the Schrödinger operator is obtained as the limit of the solution of a Bellman–Isaacs equation of discounted type. Furthermore, a singular limit of the equation is studied in relation to semi‐classical analysis.
Asymptotic distribution of eigenvalues for elliptic boundary value problems
Authors: Zielinski Lech
Published: December 2024

We consider the Weyl formula describing the asymptotic behaviour of the number of eigenvalues $N(\lambda)$ for elliptic boundary value problems. The remainder estimate of the form $N(\lambda){\rm O}(\lambda^{-\mu})$ is proved with $\mu<r/(2m)$ in the case of operators of order $2m$ with Hölder coefficients of exponent $r\in \,]0; 1]$ .
Damping estimates for oscillatory integral operators with finite type singularities
Authors: Comech Andrew
Published: December 2024

We derive damping estimates and asymptotics of $L^p$ operator norms for oscillatory integral operators with finite type singularities. The methods are based on incorporating finite type conditions into $L^2$ almost orthogonality technique of Cotlar–Stein.
Error bound in trace norm for Trotter–Kato product formula of Gibbs semigroups
Authors: Ichinose Takashi , Tamura Hideo
Published: December 2024

We study the error bound in the trace norm for the Trotter–Kato exponential product formula of Schrödinger semigroups with a certain class of singular potentials. The error bound heavily depends on the growth and smoothness properties of potentials. As an application, we can also obtain the error estimate in calculating an approximate value of partition function, which is one of the most important quantities in quantum statistical mechanics, by use of the exponential product formula.
Energy‐transport model for a nondegenerate semiconductor: Convergence of the Hilbert expansion in the linearized case
Authors: Génieys S.
Published: December 2024

This paper is concerned with the derivation of an energy‐transport model from the Boltzmann equation for a nondegenerate semiconductor with a parabolic band structure. Electron–electron collisions and elastic collisions (i.e., impurity scattering and the “elastic part” of phonon collisions) are retained as leading order terms. Then, a Hilbert expansion leads to an energy‐transport model, and a Chapman–Enskog expansion leads to the same energy‐transport model if the electric field vanishes. For the case of the Boltzmann equation linearized about a global equilibrium, the convergence of the Hilbert expansion is shown when the electric field vanishes.
Sur un théorème du type de Maillet–Malgrange pour les équations $q$‐différences‐différentielles
Authors: Zhang Changgui
Published: December 2024

On décrit la croissance des coefficients des séries entières solutions formelles d’une équation holomorphe mélangeant opérateurs différentiels et opérateurs aux $q$ ‐différences. Suivant une idée de Malgrange (Asympt. Anal. 2 (1989), 1–4), nous établissons une version généralisée du théorème de Maillet–Malgrange à l’aide du théorème des fonctions implicites.

Abstract. The growth of the coefficients of a formal power series satisfying a holomorphic $q$ ‐difference differential equation is described, where differential and $q$ ‐difference operators are mixed. Following an idea of Malgrange (Asympt. Anal. 2 (1989), 1–4) and using implicit function theorem, a generalization of the Maillet–Malgrange theorem is established.
Stability of ZND detonation waves in the Majda combustion model
Authors: Roquejoffre Jean‐Michel , Vila Jean‐Paul
Published: December 2024

This paper is the first of a series aimed at deriving uniform stability results for strong ZND – Zeldovich–Neumann–Döring – detonation waves, in the context of singular perturbations. In this work, the Majda and Majda–Rosales models with small viscosity are examined, and a dispersion relation accounting for the linear stability of the wave is derived, by means of matched asymptotics. A rigorous justification follows, in which the main difficulty is a uniform spectral estimate.
An inverse problem related to channel scattering operators
Authors: Wang X.P.
Published: December 2024

In this paper, we study the inverse scattering related to a channel scattering operator $S_{\alpha\beta}$ in $N$ ‐body problems. Given the incoming and outgoing channels $\alpha$ , $\beta$ associated with a same, but arbitary cluster decomposition, $a$ , of the $N$ ‐body system, we prove that all effective interactions between the mass‐centers of the clusters in $a$ can be reconstructed from the high energy asymptotics of scattering matrices $S_{\alpha\beta}(\lambda)$ .
Limit behaviour of solutions to a class of boundary value problems with equivalued surface for elliptic equations
Authors: Li Feng‐Quan
Published: December 2024

In this paper, we discuss the limit behaviour of solutions to a class of boundary value problems with equivalued surface for linear elliptic equations when the equivalued surface boundary shrinks to a fixed point on the boundary.
The Child–Langmuir asymptotics for magnetized flows
Authors: Ben Abdallah Naoufel , Degond Pierre , Méhats Florian
Published: December 2024

The Child–Langmuir asymptotics of the so‐called 1.5‐dimensional Vlasov–Maxwell, modelling cross field diodes, is investigated. A set of limit problems including magnetically insulated and noninsulated regimes are exhibited and analyzed. The solutions of the Vlasov–Maxwell system are shown to converge towards a solution of the limiting problem.
Asymptotic behavior of the solutions of monotone problems in flat cylinders
Authors: Sili A.
Published: December 2024

We consider a vectorial monotone problem posed on a cylinder ${\varOmega}^\varepsilon=\omega\times (0,\varepsilon L)$ of $\mathbb{R}^N$ and we study its limit behavior as $\varepsilon$ goes to $0$ . We show that the limit solution solves an elliptic system posed on $\omega$ . We give also a corrector result as well as an error estimate under some regularity hypotheses.
Asymptotic behaviour of elliptic systems with mixed absorption and source terms
Authors: Bidaut‐Véron Marie‐Francoise , Grillot Philippe
Published: December 2024

We study the limit behaviour near the origin of the nonnegative solutions of the semilinear elliptic system [Formula: see text] where $p,q,a,b\in \mathbb{R},$ with $p,q>0$ , $pq\neq 1$ . We give a priori estimates without any restriction on the values of $p$ and $q$ .
Long‐time asymptotics of non‐decaying solutions of the $(2+1)$‐dimensional Gardner equation
Authors: Anders I.
Published: December 2024

We prove the existence of non‐decaying real solutions of the $(2+1)$ ‐dimensional Gardner equation, vanishing when $x\to +\infty$ . We give asymptotic formulae for the solutions in terms of infinite series of asymptotic solitons with curved lines of constant phase and varying amplitude for $\vert t\vert \to\infty$ .
Distribution of the resonances and local energy decay in the transmission problem
Authors: Popov Georgi , Vodev Georgi
Published: December 2024

We study the resonances associated to the transmission problem for a strictly convex obstacle provided that the speed of propagation of the waves in the interior of the obstacle is strictly greater than the speed in the exterior. We prove that there are no resonances in a region of the form ${\rm Im}\,z\leqslant C_1|z|^{-1},\ |{\rm Re}\,z|\geqslant C_2>0$ . Using this we obtain some uniform estimates on the decay of the local energy.
Homogenization with multiple scales
Authors: Tassa Tamir
Published: December 2024

We study the homogenization of oscillatory solutions of partial differential equations with a multiple number of small scales. We consider a variety of problems – nonlinear convection–diffusion equations with oscillatory initial and forcing data, the Carleman model for the discrete Boltzman equations, and two‐dimensional linear transport equations with oscillatory coefficients. In these problems, the initial values, force terms or coefficients are oscillatory functions with a multiple number of small scales – $f(x,{x}/{{\varepsilon}_1},\ldots,{x}/{{\varepsilon}_n})$ . The essential question in this context is what is the weak limit of such functions when ${\varepsilon}_i \downarrow 0$ and what is the corresponding convergence rate. It is shown that the weak limit equals the average of $f(x,\cdot)$ over an affine submanifold of the torus $T^n$ ; the submanifold and its dimension are determined by the limit ratios between the scales, $\alpha_i= \lim {{\varepsilon}_1}/{{\varepsilon}_i}$ , their linear dependence over the integers and also, unexpectedly, by the rate in which the ratios ${{\varepsilon}_1}/{{\varepsilon}_i}$ tend to their limit $\alpha_i$ . These results and the accompanying convergence rate estimates are then used in deriving the homogenized equations in each of the abovementioned problems.
Boundary layer analysis in the homogenization of neutron transport equations in a cubic domain
Authors: Bal Guillaume
Published: December 2024

The homogenization of neutron transport source problems in a finite domain with periodic structure is considered. It is known that the solution of such problems can be factored asymptotically as the product of two terms. The first one gives the local behavior of the neutron transport and is a solution of a periodic transport equation. The second term contains the large scale fluctuations of the neutron density and is a solution of a homogeneous diffusion equation in finite domain. In this paper we present a detailed analysis of the first‐order correction to the expansion that accounts for the neutron leakage at the boundary of the domain. We study a multi‐dimensional boundary layer equation by considering half‐space problems with heterogeneous boundary conditions and exponentially decaying source terms. Modified boundary conditions are then obtained for the homogeneous diffusion equation.
On blow‐up and asymptotic behavior of solutions to a nonlinear parabolic equation of second order
Authors: Boni Théodore K.
Published: December 2024

We obtain some sufficient conditions under which solutions to a nonlinear parabolic equation of second order with nonlinear boundary conditions exist globally or blow up in a finite time. We also give the asymptotic behavior of solutions which tend to zero as $t\rightarrow\infty$ . Finally, we obtain the asymptotic behavior near the blow‐up time of certain blow‐up solutions and describe their blow‐up set.
Homogenization of the Ginzburg–Landau functional with a surface energy term
Authors: Berlyand Leonid
Published: December 2024

We study a nonlinear homogenization problem in perforated domains for the Ginzburg–Landau functional with a surface energy integral term which was introduced in the theory of liquid crystals. Under certain conditions between the inclusion size and the order of the surface energy integral we compute the nonlinear homogenized problem and prove the convergence of the solutions. An additional relation between the domain size and physical parameters provides the uniqueness of the homogenized limit. Our proof is based on a variational approach and does not require strict periodicity of the perforated domains.
Global existence of small solutions to the generalized derivative nonlinear Schrödinger equation
Authors: Hayashi Nakao , Miao Changxing , Naumkin Pavel I.
Published: December 2024

We study the global in time existence of small solutions to the generalized derivative nonlinear Schrödinger equations of the form [Formula: see text] where the space dimension $ n \geqslant 3 $ , the initial data $ u_0 $ are sufficiently small, $\bar u$ is the complex conjugate of $u$ and the nonlinear term $\mathcal{N}$ is a smooth complex valued function $\mathbf{C}\times \mathbf{C}^n\times \mathbf{C}\times \mathbf{C}^n\rightarrow \mathbf{C}$ . We assume that ${\mathcal N}$ is a quadratic function in the neighborhood of the origin and always includes at least one derivative, that is, $|{\mathcal N}(u,w,\bar u,\bar w)| \leqslant C|w|(|u|+|w|)$ , for small $u$ and $w$ in the case of space dimensions $n = 3, 4$ . As a typical example we consider the case of the polynomial type nonlinearity of the form [Formula: see text] with $ w = (w_j)_{1\leqslant j\leqslant n}$ , $ \lambda_{\alpha\beta\gamma} \in \mathbf{C} $ , $l\geqslant 2,$ $m \geqslant 1$ for $ n=3,4$ , and $m \geqslant 0$ for $ n\geqslant 5 $ .

We prove the global existence of solutions to the Cauchy problem (A) under the condition that the initial data $u_0 \in \mathbf{H}^{[n/2]+5,0} \cap \mathbf{H}^{[n/2]+3,2}$ , where $\mathbf{H}^{m,s} = \{ \phi \in \mathbf{L}^2;\ \|\phi\|_{m,s} = \|(1+x^2)^{s/2} (1-\Delta)^{m/2}\phi\|_{\mathbf{L}^2} <\infty\}$ is the weighted Sobolev space. We also show the existence of the usual scattering states. Our result for $n=3,4$ is an improvement of Hayashi and Hirata, Nonlinear Anal. 31 (1998), 671–685.
Error estimation in the Bernoulli–Navier model for elastic rods
Authors: Irago H. , Viaño J.M.
Published: December 2024

Let $u(\varepsilon)$ be the rescaled three‐dimensional displacement field solution of the linear elastic model for a clamped prismatic straight rod ${\varOmega}^\varepsilon$ having cross section with diameter of order $\varepsilon$ , and let $u^0$ be the corresponding Bernoulli–Navier displacement. In this article we establish that the error $\|u(\varepsilon)-u^0\|_{1,{\varOmega}}$ in the reference space $[H^1({\varOmega})]^3$ is of order $\varepsilon^{1/2}$ . We mainly use an auxiliar corrector function and we prove that this estimation cannot be improved using other corrector functions of the same family.
Homogenization of a class of degenerate parabolic equations
Authors: Paronetto F.
Published: December 2024

In this paper we study the homogenization problem of a sequence of degenerate linear parabolic operators [Formula: see text] ( $\gamma, \beta \geq 0$ ), where the matrix of the coefficients $a(y,\tau)$ verifies the degenerate elliptic condition $\lambda(y)\vert \xi\vert ^2\leq (a(y,\tau)\cdot \xi,\xi)\leq L\lambda(y) \vert \xi\vert ^2$ , $\lambda$ being a weight satisfying a Muckenhoupt’s condition ( $\lambda\in A_2$ ) and $(\mu,\lambda)$ being a pair of weights satisfying a generalized Muckenhoupt’s condition.
A class of singularly perturbed singular Volterra integral equations
Authors: Skinner L.A.
Published: December 2024

A uniformly valid asymptotic expansion is established for the solution to certain singularly perturbed generalized Abel integral equations. The results are applied to a problem in heat conduction.
Evolution of adiabatically perturbed resonant states
Authors: Perelman Galina
Published: December 2024

We describe the long time behavior of the resonant states for a class of Hamiltonians adiabatically depending on time in the case where the lifetime of the resonance is comparable with the adiabatic scale.
Expansion of the inverse of positive‐definite Toeplitz operators over polytopes
Authors: Kateb Djalil , Seghier Abdellatif
Published: December 2024

Let $\tilde\varLambda $ be a polytope in $\mathbb{R}^d$ , $\varLambda =\tilde\varLambda \cap\mathbb{Z}^{d}$ be its trace on the group $\mathbb{Z}^{d}$ and let $T_{\varLambda }(f)$ be a Toeplitz operator, with a positive symbol $f\in L^{\infty}(\mathbb{T}^{d})$ , defined on the Hardy space $H^2(\varLambda )$ . With some additional assumptions on $f$ , a purely algebraic inverse formula of $T_{\varLambda }(f)$ is given. The geometric properties of the operators are highlighted when $\varLambda $ is inflated to get $\varLambda _\lambda =\lambda \varLambda $ with $\lambda=2^{m}$ chosen sufficiently large. A localization result for the inverse operator is obtained. When we are sufficiently close to a $(d-k)$ ‐dimensional face of the inflated polytope, the localized inversion formula is reduced to those operators reflecting this proximity. Subsequently an analogue of the strong Szegő limit theorem is stated; a $d+1$ order asymptotics formula of the trace of the inverse is given that connects each operator of the sum with some geometric measures of our polytope (volume, area, $\,\ldots$ ). Furthermore, the results of Thorsen and Doktorski are retrieved with the help of the Ehrart lattice enumerator formula.
Some generalizations of the Cahn–Hilliard equation
Authors: Miranville Alain
Published: December 2024

Our aim in this article is to discuss some questions related to the existence and uniqueness of solutions and on the existence of finite dimensional attractors for Cahn–Hilliard type equations. Compared to the classical Cahn–Hilliard equation, these models take into account the anisotropy of the material, the work of internal microforces and the deformations of the material.
Asymptotic analysis of the Navier–Stokes system in a plane domain with thin channels
Authors: Maz’ya V.G. , Slutskii A.S.
Published: December 2024

A flow of viscous incompressible fluid in a domain $&OHgr;_ϵ$ depending on a small parameter $ϵ$ is considered. The domain $&OHgr;_ϵ$ is the union of a domain $&OHgr;_0$ with piecewise smooth baundary and thin channels with width of order $ϵ$ . Every channel contains one angle point of the domain $&OHgr;_0$ near the channel’s inlet.

We prove the existence of a solution (v $_ϵ,p_ϵ$ ) to the Navier–Stokes system such that in a neighbourhood of an angle point of the domain $&OHgr;_0$ the pair (v $_ϵ,p_ϵ$ ) is equal, up to a term with finite kinetic energy, to the Jeffery–Hamel solution which describes a plane viscous source (or sink) flow between the sides of the angle. In the channels the pair (v $_ϵ,p_ϵ$ ) asymptotically coincides with the Poiseuille solution. Asymptotic expressions for the kinetic energy and the Dirichlet integral of (v $_ϵ,p_ϵ$ ) are obtained.
Time‐dependent Stokes flow through a randomly perforated porous medium
Authors: Wright Steve
Published: December 2024

An incompressible fluid is assumed to satisfy the time‐dependent Stokes equations in a porous medium. The porous medium is modeled by a bounded domain in $R^n$ that is perforated for each ε > 0 by ε‐dilations of a subset of $R^n$ arising from a family of stochastic processes which generalize the homogeneous random fields. The solution of the Stokes equations on these perforated domains is homogenized as ε → 0 by means of stochastic two‐scale convergence in the mean, and the homogenized limit is shown to satisfy a two‐pressure Stokes system containing both deterministic and stochastic derivatives and a Darcy‐type law with memory which generalizes the Darcy law obtained for fluid flow in periodically perforated porous media.
Thin ferromagnetic films
Authors: Ammari Habib , Halpern Laurence , Hamdache Kamel
Published: December 2024

The effect of thin ferromagnetic films is studied in this paper. We shall adopt the Landau–Lifschitz–Gilbert equation as a phenomenological model for the ferromagnetic materials. Asymptotic analysis of the fields and the magnetization vector inside thin ferromagnetic films are performed and their convergences are established. Our results reveal the physical nature of this nonlinear model. They also provide an effective method for overcoming the computational difficulties that arise in thin ferromagnetic coatings.
Long‐time diffusive behavior of solutions to a hyperbolic relaxation system
Authors: Liu Hailiang , Natalini Roberto
Published: December 2024

We study the large time behavior of the solutions to the Cauchy problem for the system with relaxation source ut+vx=0, vt+a2ux=f(u)−v, with $(x,t)\in{\mathbb{R}} \times{\mathbb{R}} ^{+}$ , for the initial data (u,v)=(u0,v0) at t=0, with $u_{0},v_{0}\in L^{1}({\mathbb{R}})\cap L^{\infty}({\mathbb{R}})$ , f(u)=αu2/2 and |v0|≤au0. Under the sub‐characteristic condition we show that, as t→∞, the component u tends towards a fundamental solution of the convection‐diffusion equation ut+f(u)x=a2uxx in the Lp norm, at a rate faster than t−(p−1)/2p.
The grazing collision limit for the Boltzmann–Lorentz model
Authors: Buet C. , Cordier S. , Lucquin‐Desreux B.
Published: December 2024

The Lorentz operators are derived from either Boltzmann or Fokker–Planck collisions operators when considering a mixture of species with disparate masses [8]. The Fokker–Planck operator is the so called “grazing collision limit” of the Boltzmann operator as proved in [1,12,7]. In our simpler case, we improve the results by proving uniform in time convergence and by controling the speed of the trend to equilibrium. The results are based on a spectral analysis of the operators which share the same basis of eigenfunctions.
Semi‐classical counting function with application to quantum current
Authors: Butler J.
Published: December 2024

We obtain a new two‐term asymptotic formula for the counting function of eigenvalues of h pseudodifferential operators in the limit as h→0. Recent results concerning clustering of eigenvalues obtained in [7] follow in corollary and, as an application, we consider the semi‐classical behaviour of the quantum current studied recently in [2].
Coercive approximation of viscoplasticity and plasticity
Authors: Chełmiński Krzysztof
Published: December 2024

This work generalizes the result from [9], and for all viscoplastic models of monotone‐gradient type presents a convergence result of the coercive approximation (see [4]) to a global solution of the original noncoercive problem. In the case of elasto‐perfect plasticity we approximate the model of Prandtl and Reuss by a sequence of the coercive Melan–Prager models.
Sur les modèles discrets de l'équation de Boltzmann avec termes linéaires et quadratiques
Authors: Yamazaki Mitsuru
Published: December 2024

Dans cet article, on étudie les modèles discrets de l'équation de Boltzmann avec termes linéaires et quadratiques dans l'espace unidimensionnel. On montre d'abord l'existence d'une solution avec estimation explicite pour les modèles droite‐gauche, une généralisation des modèles de Broadwell. Après avoir montré l'existence globale d'une solution (resp. avec estimation explicite) pour les modèles discrets à données (localement) bornées (resp. et sommable), on étudie le comportement asymptotique des solutions et montre deux phémonénas distinctes correspondant aux conditions imposées pour les coefficients de termes linéaires.
Asymptotic stability of almost periodic systems of impulsive differential‐difference equations
Authors: Stamov Gani T.
Published: December 2024

By means of piecewise continuous functions which are analogues of Lyapunov's functions sufficient conditions for the asymptotic stability of almost periodic systems of impulsive differential‐difference equations are obtained.
Diffusion driven by collisions with the boundary
Authors: Degond P. , Mancini S.
Published: December 2024

We present a mathematically rigorous derivation of a diffusion model previously introduced by the first author to model the diffusion of charged‐particles moving in the gap between two plane parallel plates. The particles are subject to crossed electric and magnetic fields and to collisions against the surface of the solid plates. The surface collisions are supposed to be elastic. Under appropriate scaling assumptions, the particle distribution function converges to a function of the energy and of the longitudinal position coordinates only, which evolves in time according to a diffusion equation. A rigorous convergence proof is given. The proof relies on precise estimates on the trace of the distribution function at the boundary.
Inviscid boundary conditions and stability of viscous boundary layers
Authors: Rousset Frédéric
Published: December 2024

We study the set of residual boundary conditions for a one‐dimensional hyperbolic system of conservation laws set in x>0 which appears when the diffusion coefficient of Dirichlet's problem for a parabolic perturbation tends to zero. We show that this set is a submanifold in a vicinity of a point where the Evans function of the associated profile of boundary layer is such that D(0)≠0.

Next we linearize a multidimensional hyperbolic problem about a constant state in the set of residual conditions and a viscous approximation about the associated profile of boundary layer. We show that the Evans function for the viscous problem reduces in the long‐wave limit to the Lopatinsky determinant. We deduce that inviscid well‐posedness is necessary for stability of the boundary layer.
Exact controllability of semilinear plate equations
Authors: Zhang Xu
Published: December 2024

In this paper, we obtain the exact controllability for a class of semilinear plate equations under a superlinear growth assumption on the nonlinearity. For this purpose, we need an explicit observability estimate for the linear plate equation with a potential, which is derived by means of Carleman estimates together with the usual energy estimate.
Effective boundary conditions for thin ferromagnetic coatings. Asymptotic analysis of the 1D model
Authors: Haddar H. , Joly P.
Published: December 2024

We justify, for a simplified non‐linear law of ferromagnetic materials, the use of effective boundary conditions in order to simulate the effect of thin ferromagnetic coatings in electromagnetic scattering problems. The numerical comparisons between exact an approximate solutions have been done in [2], and the present work quantifies the error with respect to the coating thickness.
Asymptotics for the vortex condensate solutions in Chern–Simons–Higgs theory
Authors: Han Jongmin
Published: December 2024

In this paper we study asymptotic behaviors of the maximal vortex condensate solutions in the Chern–Simons–Higgs theory when the coupling parameter κ goes to zero. Using Tarantello's weak convergence result for F12 [16], we derive the weak convergence of A0/κ. As a consequence we compute the locally uniform convergence rate of Higgs fields, |�κ|2→1, away from the vortices and the blow‐up rate of |ψκj|2 at the vortex point pj.
A hierarchy of hydrodynamic models for plasmas. Quasi‐neutral limits in the drift‐diffusion equations
Authors: Jüngel Ansgar , Peng Yue‐Jun
Published: December 2024

This paper is a continuation of a series of papers in which (quasi‐) hydrodynamic models for plasmas are rigorously derived by means of asymptotic analysis. Here, the quasi‐neutral limit (zero‐Debye‐length limit) in the drift‐diffusion equations is performed in the two cases: weakly ionized plasmas and not weakly ionized plasmas.

The model consists of the continuity equations for the electrons and ions, the constitutive relations for the particle current densities, and the Poisson equation for the electrostatic potential in a bounded domain. In the case of a weakly ionized plasma, the continuity equation for the electrons is replaced by a relation between the electrostatic potential and the electron density such that the Poisson equation becomes nonlinear. The equations are complemented by mixed Dirichlet–Neumann boundary conditions and initial conditions.

The quasi‐neutral limits are shown without assuming compatibility conditions on the boundary densities. The proofs rely on the use of the so‐called entropy functional which yields appropriate uniform estimates, and compensated compactness methods.
Uniform rates of decay for full von Kármán systems of dynamic viscoelasticity with memory
Authors: Muñoz Rivera Jaime E. , Perla Menzala Gustavo
Published: December 2024

In this paper we consider the dynamical full von Kármán system of equations for viscoelastic plates. The main result of this paper says that the uniform rate of decay of the energy function associated with the system depends on the rate of decay of the relaxation functions. Our result can be seem as a refinement of our previous work [23] on the so called “modified” von Kármán model in which case the in‐plane displacements are not taken into account.
A BGK approximation to nonlinear parabolic initial‐boundary value problems
Authors: Guarguaglini F.R. , Terracina A.
Published: December 2024

We present a relaxation semilinear system of conservation laws with source which approximates nonlinear parabolic equations with initial and boundary conditions. The system can be interpreted as a BGK (Bhatnagar, Gross, Krook) model with a finite number of velocities. We prove the well‐posedness of the model, a priori estimates and we obtain the convergence towards the solution of the parabolic problem. Moreover we prove a similar result for a weakly degenerate problem.
Estimates of the constants in generalized Ingham's inequality and applications to the control of the wave equation
Authors: Jaffard Stéphane , Micu Sorin
Published: December 2024

We are considering Ingham's inequality (see [8]) for a family of exponential functions {eiλnt}n≥1, in the case in which the distance |λn+1−λn| between two consecutive exponents becomes smaller and smaller for |n|≤N but there still exists an asymptotic gap sufficiently large. We give explicit estimates for the two constants appearing in the inequality and we analyze how does the small gap between the first exponents affect the constants. These results are applied to a control problem for the wave equation in a case in which the geometric condition for controllability, deduced in [4], are not satisfied.
Spectral asymptotic in the large coupling limit
Authors: Bruneau Vincent , Carbou Gilles
Published: December 2024

In this paper, we study a singular perturbation of an eigenvalues problem related to supra‐conductor wave guides. Using boundary layer tools we perform a complete asymptotic expansion of the eigenvalues as the conductivity tends to +∞.