bluuebunny/crossref_metadata_2025 huggingface dataset:
O ENSINO REMOTO DURANTE A PANDEMIA
Authors: COSTA Felipe Soares , MESQUITA Bruno Ribeiro de , RODRIGUES Miguel Antônio
Published: December 2024

As aulas remotas surgiram de repente como uma inovação tecnológica e uma rápida oportunidade para que os alunos de qualquer modalidade de ensino não sofressem extremos atrasos no processo de ensino-aprendizagem e na conclusão do ano letivo em razão da suapensão das aulas presencias em decorrência da pandemia da COVID-19. Diante disso, este trabalho objetiva principalmente investigar a eficácia do ensino remoto implementado durante o período pandêmico em uma turma de 8º ano de uma escola municipal em Uruçuí-PI. A situação problema visou principalmente abordar todas as dificuldades e barreiras enfrentadas especificamente pelos estudantes da disciplina de matemática de como aprender de maneira remota durante esse período e também como deveria ser a qualificação profissional do docente que iria enfrentar esse novo desafio repentino. Essa investigação analisou a nova metodologia de ensino adotada para os alunos a fim de observar as estratégias do ensino remoto com suas aplicações e resultados, verificar as dificuldades envolvendo tanto os professores quanto os alunos com o novo método, além de descrever as ferramentas tecnológicas que foram sendo usadas para ministrar as aulas voltadas para a preparação do aluno e do professor para o uso delas. Neste trabalho, a investigação aborda as formas quantitativa e qualitativa. Os resultados mostraram que as aulas remotas não contribuíam de forma efetiva para o aprendizado dos alunos em razão da dificuldade de manuseio de equipamentos tecnológicos para que o ensino acontecesse de maneira remota. Tudo isso mostrou que a qualificação profissional é de suma importância em qualquer aspecto para a melhoria do processo ensino-aprendizagem.
TRILHA INTERPRETATIVA: ESTRATÉGIA DE CONSERVAÇÃO DA CAATINGA, ASSOCIADA AO ENSINO EM AMBIENTE NÃO FORMAL DE APRENDIZAGEM
Authors: BRAGA DAN VÍTOR VIEIRA , SÁ DANIELA PEREIRA DE BARROS E
Published: December 2024

As trilhas são a principal infraestrutura de manejo de visitantes em áreas naturais, mas se faz necessária a mitigação dos efeitos negativos da visitação em áreas protegidas. A interpretação ambiental tem sido aliada da educação ambiental em Unidades de Conservação. As trilhas na Caatinga permitem que os estudantes compreendam a biodiversidade e os desafios enfrentados em conservação deste bioma. Desta forma, objetivou-se realizar um levantamento das potencialidades interpretativas presentes na “trilha do cruzeiro”, para a subsidiar a implantação de uma trilha autoguiada destinada à sensibilização dos visitantes para a conservação do Bioma Caatinga, bem como para seu uso como instrumento de ensino em ambiente não formal de aprendizagem. A pesquisa foi realizada no município de Salgueiro/PE. A metodologia adotada foi uma pesquisa de campo, com de natureza qualitativa e também de cunho descritivo. Foram mapeados os espaços ao longo da trilha que possuíam potencial interpretativo para a realização de educação ambiental e conscientização acerca da biodiversidade do bioma Caatinga. No inventário dos indivíduos da flora e da fauna presentes da trilha foi realizado o método da caminhada aleatória ao longo da trilha. Posteriormente, os pontos de interpretação identificados foram descritos com o foco no seu potencial em termos de educação ambiental, bem como, da visualização de curiosidades presentes na paisagem da Serra do Cruzeiro. Com base nos resultados apresentados, conclui-se que a trilha da serra do cruzeiro possui elevado potencial de interpretação da paisagem com diferentes focos de interpretação. Faz-se necessário a implantação de infraestruturas de suporte para mitigar os impactos negativos oriundos da visitação e a rede de ensino (básico, técnico e superior) deve incluir esta trilha interpretativa em seu planejamento pedagógico. Por fim, a população da cidade de Salgueiro deve preservar a qualidade ambiental deste monumento natural e também cobrar do poder público as ações necessárias a sua preservação e manutenção.
INTEGRAÇÃO DE METODOLOGIAS ATIVAS NO ENSINO DE GENÉTICA MENDELIANA DURANTE O ISOLAMENTO NA PANDEMIA DE COVID-19
Authors: SOUSA VICTOR ALEXANDRE SILVA , MACIEL WYADYSON FRANCISCO DE SOUSA , MOURA IVANALDO RIBEIRO DE , GOMES DIVAMELIA DE OLIVEIRA BEZERRA , SOBRINHO FRANCISCO DE ASSIS DINIZ
Published: December 2024

A abordagem da genética costuma ser complexa e difícil, principalmente para estudantes em diferentes etapas da educação, um desafio que se acentua no ensino à distância, conforme demonstrado em várias pesquisas. O propósito deste estudo foi analisar a eficácia de metodologias ativas em conjunto com aulas tradicionais no ensino de genética clássica, além de explorar como os alunos percebem a efetividade dessas estratégias. Adotou-se um método híbrido, tanto qualitativo quanto quantitativo, para descrever e investigar os dados de uma amostra de 106 estudantes do curso técnico do IFPI. A pesquisa foi realizada de maneira experimental, com um grupo controle que não participou das metodologias ativas e um grupo experimental que se envolveu em técnicas de ensino interativas, como debates, estudo de casos, simulações e atividades em grupo. Foram utilizados questionários para entender a percepção dos alunos sobre a eficácia e a clareza do conteúdo ensinado. Também foram examinados os obstáculos do ensino remoto, levando em conta a adaptação dos alunos às plataformas online e as dificuldades de engajamento nesse formato. Como era de se esperar, o grupo experimental obteve um desempenho acadêmico superior, refletido nas notas finais, que foram consistentes entre as turmas (9,68, 9,6 e 9,63). Esses achados ressaltam a importância de estratégias que promovem a participação ativa, favorecendo uma melhor retenção do conhecimento e uma experiência de aprendizado mais dinâmica e envolvente. A pesquisa conclui que a combinação de abordagens tradicionais com métodos de ensino ativos, mesmo em um ambiente remoto, é uma estratégia eficaz para o aprendizado da genética. O uso de metodologias ativas não apenas resultou em melhores desempenhos acadêmicos, mas também demonstrou um aumento na satisfação e no interesse dos alunos pela matéria, indicando que a fusão de práticas pedagógicas tradicionais e inovadoras pode beneficiar o ensino de tópicos complexos como a genética.
Mathematical and experimental study of the direct contact membrane distillation method for desalination using a hydrophobic electrospun nanofibers membrane
Authors: Safi Nawras N. , Waisi Basma I.
Published: December 2024

This paper examines the performance of a Direct Contact Membrane Distillation (DCMD) system experimentally and theoretically. The system uses a super hydrophobic electrospun nanofiber membrane to desalinate water. Investigations were carried out into how the feed concentration, feed flow rate, and feed temperature affected permeate flux. as system operating parameters to aid in comprehending the factors impacting the DCMD process. The application of DOE and Taguchi methods achieved statistical optimization of the DCMD process's performance. In addition, the study of mass and heat transport in DCMD was described by a theoretical model. While the feed concentration (0- 210 g/L) significantly affected flux, the feed's temperature (35-55 °C) and flow rate (0.2-0.6 L/min) mostly dominated the impact on system performance. The created model numerically solved the DCMD process using MATLAB software, describing it as a system of nonlinear equations. Various operating conditions were used to investigate the efficiency of the superhydrophobic electrospun nanofiber membrane in treating 210 g/L NaCl salt water. Changing the feed temperature and concentration affected the hypothetically suggested path across the membrane, according to the simulation results presented in this paper. Excellent agreement was observed between the experiment results and the constructed model's predicted results. Every instance maintained a high salt rejection rate (over 99.9%). The DCMD produced a gain output ratio (GOR) of 0.87 and a temperature polarization coefficient of 0.78 to 0.91. The system achieved a maximum thermal efficiency of 73.5%. The optimal parameters, which are 70 g/L, 0.6 L/min, and 55°C.
Pleomorphic dermal sarcoma of the scalp with intracranial space involvement: management of a rare entity. Illustrative case
Authors: Altieri Roberto , Cuomo Roberto , Vitale Giovanni , Limongelli Sebastiano , Massariello Domenico , La Rocca Giuseppe , Corvino Sergio , Barbarisi Manlio
Published: December 2024

BACKGROUND

Exophytic tumors of the calvaria (ETCs) remain a challenging pathology because of their complex management. The authors discuss the case of a woman with a large exophytic mass of the right frontotemporal region and underline their decision-making process on the management of this unique case and possible similar ones.

OBSERVATIONS

Neuroradiological findings showed a calvarial tumor with both epicranial and intracranial extension involving the frontotemporal bone with a mixed component (lytic and sclerotic) and dural infiltration with a pseudonodular pattern. A wide en bloc excision from the skin to the dura mater was performed. The compound 5-aminolevulinic acid (5-ALA) was not very useful in identifying the tumor boundaries. One-step cranioplasty and a skin pedicle flap were used to reconstruct the anatomical defect. Acellular dermal matrix was used to repair the uncovered calvaria. Pathological examination confirmed the diagnosis of pleomorphic dermal sarcoma (PDS).

LESSONS

In the evaluation of an ETC, PDS should be considered. Wide en bloc excision, if achievable, should be considered the gold standard. The 5-ALA was not helpful, and a pedicle skin flap could be considered as a less invasive alternative to microsurgical reconstruction. The use of an acellular matrix implant on the contralateral exposed galea increases the rate of reconstruction success.

https://thejns.org/doi/10.3171/CASE24457
Reakcija kadifice (Tagetes erecta) i petunije (Petunia hybrida) na različite tretmane vodnog stresa
Authors: Marković Monika , Kšenek Mihaela , Barač Željko , Matoša Kočar Maja , Jug Irena , Ravlić Marija
Published: December 2024

Istraživanje je provedeno u kontinentalnoj Hrvatskoj, Požega, 2019. godine. Cilj istraživanja bio je proučiti rast i kvalitetu kadifice (Tagetes erecta) i petunije (Petunia hybrida), u pogledu morfoloških karakteristika (broj cvjetova/cvatova i grana po biljci, visinu biljke, masu svježeg cvijeta/cvati, i promjer cvijeta/ cvati) i estetske vrijednosti cvijeta/cvati u odnosu na različite razine vodnog stresa. Istraživanje u posudama je provedeno u plasteniku, postavljeno kao slučajni blok raspored u tri ponavljanja. Tretmani navodnjavanja su: a1 – 70 % retencijskog kapaciteta (RK), a2 – 85 % RK i a3 – 100 % RK supstrata. Vlažnost supstrata ima značajan (p<0,01) utjecaj na svježu nadzemnu masu kadifice, masu svježe cvati i promjer cvati te značajan (p<0,05) utjecaj na visinu biljke. Kod petunije, različiti tretmani navodnjavanja pokazali su značajan (p<0,01) utjecaj na broj grana po biljci te značajan (p<0,05) utjecaj na broj cvjetova po biljci, svježu nadzemnu masu i promjer cvijeta. Sva promatrana morfološka svojstva su se proporcionalno povećavala s povećanjem obroka navodnjavanja, osim broja cvatova i grana kadifice, pri čemu su najveće vrijednosti zabilježene na tretmanu blagim vodnim stresom (a2).
Utjecaj oprašivača na proizvodnju lubenice
Authors: Juran Ivan , Lovasić Karla , Drmić Zrinka , Gotlin Čuljak Tajana
Published: December 2024

Čovjekove intenzivne djelatnosti uzrokovale su brojne promjene u prirodi, među kojima i narušenost bioraznolikosti i pad brojnosti oprašivača koji posljedično dovode do problema u poljoprivrednoj proizvodnji i ekonomskih gubitaka. Proizvodnja kultura čiji prinos uvelike ovisi o oprašivanju kukcima, poput lubenice, postaje sve zahtjevnija. Cilj istraživanja bio je utvrditi brojnost i vrste oprašivača na cvjetnim pojasevima implementiranim u usjev lubenice, usporediti broj prisutnih oprašivača na cvjetnim pojasevima s brojem oprašivača prisutnih u dijelu usjeva lubenice bez cvjetnog pojasa te utvrditi utjecaj oprašivača na prinos lubenice. Cvjetni pojas posijan je u lokalitetu Tovarnik. Bioraznolikost biljnih vrsta unutar cvjetnog pojasa i dijela usjeva lubenice bez cvjetnog pojasa istraživana je na sljedeći način: određena su tri zamišljena područja površine 3x3 m na kojima je napravljena procjena cvatućih biljaka iz porodica Fabaceae, Apiaceae, Asteraceae, Brassicaceae, Lamiaceae, te ostalog zasijanog i samoniklog cvijeća. Postotak cvatućih biljnih vrsta određen je prema zadanoj skali. Bioraznolikost oprašivača (Apis sp., Bombus sp., Megachilidae i Andrenidae) na dijelu usjeva lubenice s cvjetnim pojasom i dijelu usjeva lubenice bez cvjetnog pojasa praćena je na sljedeći način: unutar cvjetnog pojasa izabrana je traka dužine 50 m na kojoj su određena tri zamišljena područja veličine 3x3 m, a na svakom se zamišljenom području 4 min promatrao i bilježio broj oprašivača bez promjene položaja. Utjecaj cvjetnog pojasa na prinos lubenice određen je prosječnim brojem plodova lubenice po biljci i prosječnom masom plodova lubenice na polju lubenice s cvjetnim pojasom i na polju lubenice bez cvjetnog pojasa. Udio oprašivača u ukupno zabilježenoj entomofauni u lokalitetu Tovarnik bio je veći u usjevu lubenice s cvjetnom pojasu u odnosu na usjev lubenice bez cvjetnog pojasa. Prosječan broj plodova lubenice po biljci na dijelu usjeva lubenice s cvjetnim pojasom iznosio je 1,78, što je za 25,8 % više u odnosu na dio usjeva bez zasijanog cvjetnog pojasa gdje je prosječan broj plodova lubenice po biljci bio 1,32. Prosječna masa ploda lubenice po biljci na dijelu usjeva lubenice s cvjetnim pojasom iznosila je 7,1 kg, odnosno bila je 40,99 % veća u odnosu na dio usjeva lubenice bez cvjetnog pojasa gdje je prosječna masa ploda po biljci iznosila 4,19 kg.
Tindak Pidana Atas Perambahan Hutan Ilegal Dihubungkan Dengan Putusan Pengadilan Negeri Sungailiat Nomor 188/Pid.B/Lh/2020/Pn Sgl
Authors: Cecep Ramdani  , Nur Kholim
Published: December 2024

Penerapan sanksi terhadap perambahan hutan ilegal merupakan bagian penting dari penegakan hukum lingkungan, termasuk dalam konteks Undang-Undang Penegakan Hukum Perlindungan Lingkungan Hidup atau undang-undang lain yang relevan.  langkah yang biasanya dilakukan dalam penerapan sanksi terhadap perambahan hutan ilegal yaitu seperti penegakan Hukum oleh pihak berwenang, seperti lembaga pengawas lingkungan, kepolisian, atau instansi lain yang bertanggung jawab, melakukan penyelidikan untuk mengidentifikasi dan mengumpulkan bukti terkait aktivitas perambahan hutan illegal, penyitaan barang Bukti barang bukti berupa alat, kendaraan, atau hasil perambahan hutan yang disita sebagai bukti pelanggaran hukum, penyidikan dan penuntutan penyidikan dilakukan untuk menentukan siapa yang bertanggung jawab atas perambahan hutan ilegal tersebut penuntutan dilakukan oleh jaksa penuntut umum dengan berdasarkan bukti yang ditemukan, pengadilan jika terdakwa terbukti bersalah, sidang pengadilan akan menetapkan sanksi yang sesuai sesuai dengan ketentuan hukum yang berlaku sanksi tersebut bisa berupa denda, kerugian ganti rugi, atau bahkan hukuman penjara tergantung pada tingkat pelanggaran dan hukuman yang dijatuhkan oleh pengadilan.
Pemanfaatan media sosial upaya meningkatkan penjualan UMKM di Cikarang Utara
Authors: Maulana Suherdi , Wulandari Fitri Meiyla , Nurfatimah Siti , Amelia Maria , Elviani Sinta
Published: December 2024

Sektor Usaha Mikro, Kecil, dan Menengah (UMKM) menghadapi berbagai tantangan di era saat ini, termasuk penurunan penjualan, keterbatasan modal, gangguan distribusi, serta kesulitan dalam memperoleh bahan baku. Selain itu, pelaku UMKM perlu menyesuaikan orientasi pemasaran mereka karena meningkatnya persaingan. Banyak UMKM mulai beralih ke perdagangan elektronik (e-commerce) untuk mendukung peningkatan penjualan. Namun, transisi ini sering terkendala oleh keterbatasan kemampuan teknis para pelaku UMKM dalam memanfaatkan teknologi digital. Kegiatan pengabdian ini bertujuan untuk meningkatkan pemahaman dan keterampilan pelaku UMKM di Kecamatan Cikarang Utara, Kabupaten Bekasi, terkait pemanfaatan media sosial sebagai alat promosi dan penjualan yang efektif serta efisien. Selain itu, kegiatan ini juga mencakup pendampingan dalam penggunaan berbagai platform marketplace berbasis internet untuk mendukung pemasaran produk. Metode yang digunakan dalam kegiatan ini adalah pendekatan kontekstual, dimulai dengan penyampaian materi teori yang dilanjutkan dengan lokakarya praktis, termasuk proses unggah produk oleh para pelaku UMKM secara langsung. Hasil dari kegiatan ini menunjukkan peningkatan pemahaman mitra terkait strategi pemasaran melalui media sosial, kemampuan dalam membuat toko daring di marketplace, serta keterampilan untuk secara mandiri memanfaatkan media sosial sebagai sarana promosi produk mereka.
Penanganan lava tour merapi dalam hukum lingkungan serta pengelolaan sumber daya alam
Authors: Putra I Komang Ary Dharma , Kadek Julia Mahadewi
Published: December 2024

Lava Tour Merapi adalah salah satu destinasi wisata berbasis lingkungan yang memanfaatkan lanskap pasca-erupsi Gunung Merapi yang berada di Kawasan Rawan Bencana (KRB) III Kabupaten Sleman, Daerah Istimewa Yogyakarta. Wisata ini memperkenalkan sejarah dan dampak dari bencana alam sekaligus memberikan kesempatan unik bagi pengunjung untuk menjelajahi area yang terkena dampak erupsi dengan kendaraan off-road. Tetapi, dalam pengembangan wisata ini berdampak pada terganggunya keseimbangan hidrologi, dan hilangnya spesies flora yang berfungsi sebagai penahan tanah. Isu kritis yang melibatkan banyak pemangku kepentingan, seperti pemerintah daerah, pengelola pariwisata, masyarakat lokal, dan pemain komersial. Berdasarkan isu-isu tersebut, penelitian ini bertujuan untuk menganalisis pengelolaan Lava Tour Merapi dalam perspektif hukum lingkungan dan pengelolaan sumber daya alam yang berkelanjutan. Penelitian ini menggunakan pendekatan kualitatif dengan desain deskriptif-analitis yang bertujuan untuk memahami secara mendalam fenomena pengeolaan Lava Tour Merapi dalam konteks hukum lingkungan dan pengelolaan sumber daya alam melalui kegiatan Cimpony Visit Nasional Vol. 2. Hasil studi menunjukkan perlunya edukasi lingkungan bagi wisatawan dan kerja sama dengan masyarakat lokal dalam meningkatkan kesadaran akan pentingnya konservasi. Regulasi Undang-Undang No 23 Tahun 2024 dapat melindungi lingkungan dan masyarakat di sekitar kawasan wisata Lava Tour Merapi.
Amino acid substitution patterns in the E6 and E7 Proteins of HPV type 16: Phylogeography and Evolution
Authors: Zelenova E. E. , Karlsen A. A. , Avdoshina D. V. , Kyuregyan K. K. , Belikova M. G.
Published: December 2024

The E6 and E7 proteins of human papillomavirus (HPV) play a key role in the oncogenesis of papillomavirus infection. Data on the variability of these proteins are limited, and the factors affecting their variability are poorly understood. We analyzed the variability of the currently known sequences of HPV type 16 (HPV16) E6 and E7 proteins, taking into account their geographic origin and year of sample collection, as well as the direction of their evolution in major geographic regions of the world. All sequences belonging to HPV16 genome fragments encoding E6 and E7 oncoproteins were downloaded from the NCBI GenBank database on October 6, 2022. Samples were filtered according to the following parameters: the sequence includes at least one of the two whole open reading frames, the collection date and the country of origin are known. A total of 3,651 full-genome nucleotide sequences encoding the E6 protein and 4,578 full-genome nucleotide sequences encoding the E7 protein were sampled. The nucleotide sequences obtained after sampling and alignment were converted to amino acid sequences and analyzed using MEGA11, R, RStudio, Jmodeltest 2.1.20, BEAST v1.10.4, Fastcov, and Biostrings software. The highest variability in E6 protein structure was recorded at positions 17, 21, 32, 85, and 90, while in E7, positions 28, 29, 51, and 77 were the most variable. The samples were divided geographically into 5 heterogeneous groups: African, European, American, Southwest and South Asia and Southeast Asia. Unique amino acid substitutions (AA-substitutions) in the E6/E7 proteins of HPV16, presumably characteristic of certain ethnic groups, were identified for a number of countries. They are mainly localized in sites of known B- and T-cell epitopes and relatively rarely in structural and functional domains. The revealed differences in AA-substitutions in different ethnic groups and their colocalization with clusters of B- and T-cell epitopes suggest their possible relationship with the geographical distribution of alleles and haplotypes of the major histocompatibility complex (HLA). This may lead to the recognition of a different set of B- and T-cell epitopes of the virus, resulting in regional differences in the direction of epitope drift. Phylogenetic analysis of the nucleotide sequences encoding the E6 protein of HPV16 revealed a common ancestor, confirmed regional clustering of the E6 protein gene sequences by the set of the most common AA-substitutions, and identified cases of reversion of individual AA-substitutions when the virus distribution region changed. For the E7 protein, a similar analysis was not possible due to high sequence homology. Covariance analysis of the pooled sample revealed that there was no relationship between amino acid residues in the E6 protein, in the E7 protein, and between E6 and E7. Data obtained are important for the development of therapeutic vaccines against HPV of high carcinogenic risk.
MEASUREMENT OF THE RATES OF THE 102Pd(𝑛, γ)103Pd AND 102Ru(𝑛, γ)103Ru REACTIONS IN THE HORIZONTAL CHANNEL OF THE IR-8 REACTOR AT NRC “KURCHATOV INSTITUTE”
Authors: Zagryadsky V. A , Korolev K. O , Kravets Y. M , Kuznetsova T. M , Kurochkin A. V , Makoveeva K. A , Skobelin I. I , Strepetov A. N , Udalova T. A
Published: December 2024

Metastasis is one of the main causes of relapse and subsequent high mortality from cancer. Metastases can contain very few cells and spread throughout the body. Despite the existing variety of diagnostic imaging methods, in practice, the resolution of none of them allows one to unambiguously diagnose the presence of a tumor (clump of cancer cells) smaller than 1–2 mm in size. After surgery and tumor removal, patients are typically offered chemotherapy, external beam radiation therapy, or α- or β-emitter radionuclide therapy. This therapy has side effects that lead to additional risks and may interfere with continued treatment. Recently, a number of works, in contrast to the traditional approach, have proposed using “short-range” radionuclides instead of α- or β-emitters [1–3]. It is convenient to use Auger or conversion electron emitters as “short-acting” therapeutic agents. Auger electrons and conversion electrons have a short range and high specific linear energy loss in biological tissue; they are capable of damaging cells within a few tens of microns, but do not have a radiotoxic effect over l ng distances, without damaging healthy cells and tissues. The most efficient and convenient Auger and conversion electron emitters for practical use include 103mRh (𝑇1/2 = = 56.1 min), which has the lowest ratio of the number of γ quanta to electrons [1] and can be obtained by a generator method. The predecessors of 103mRh (𝑇1/2 = 56.1 min) in the generator can be 103Ru (𝑇1/2 = = 39.247 days) or 103Pd (𝑇1/2 = 16.99 days). In order to clarify the prospects for producing these precursors, we have measured the rates of reactions 102Ru(𝑛, γ)103Ru and 102Pd(𝑛, γ)103Pd upon neutron irradiation of metal ruthenium of natural isotopic composition and metal palladium, enriched in the 102Pd isotope to 96.36%, in a horizontal experimental channel of the IR-8 reactor.
KLEIN–GORDON EQUATION, QUNTUM RELATIVISTIC HYDRODYNAMICS AND QUANTUM SHOCK WAVES IN DESCRIBING COLLISIONS OF ATOMIC NUCLEI
Authors: D’yachenko A. T
Published: December 2024

In this work, the equations of quantum relativistic hydrodynamics are obtained from the effective Klein–Fock–Gordon equation taking into account dissipation. Taking into account dissipation in the Klein–Gordon equation leads to the need to introduce an additional thermal term and an equation for it. As a result, a closed system of equations was obtained taking into account non-equilibrium processes, which makes it possible to describe the dynamics of the process of collisions of atomic nuclei and calculate the yield of secondary particles. Solving the resulting equations makes it possible to identify quantum shock waves and the time evolution of the resulting hot spot. The calculated spectra of emitted protons in heavy ion collisions are compared with available experimental data.
REGULARIZATION OF THE SOLUTION OF DEGENERATE SYSTEMS OF ALGEBRAIC EQUATIONS BY THE EXAMPLE OF IDENTIFICATION OF THE VIRIAL EQUATION OF STATE OF A REAL GAS
Authors: Vikulov A. G
Published: December 2024

To carry out the thermodynamic calculation of the cycle in the two-phase region, an equation of state of the working fluid is necessary, as which a virial equation with unknown temperature functions is used. A degenerate system of algebraic equations is constructed with respect to unknown coefficients, which are the values of virial functions on a discrete temperature grid. Based on the regularization method, a variational iterative algorithm for solving a degenerate system of equations has been developed. A computational experiment has been conducted to confirm the efficiency of the method.
MDM ALGORITHM AND SYLVESTER’S PROBLEM
Authors: Malozemov V. N , Solovyova N. A , Tamasyan G. Sh
Published: December 2024

When developing numerical methods for solving nonlinear minimax problems, the following auxiliary problem arose: in the convex hull of some finite set in Euclidean space, find the point with the lowest norm. In 1971, B. Mitchell, V. Demyanov and V. Malozemov proposed a non-standard algorithm for solving this problem, which later became known as the MDM algorithm (based on the capital letters of the authors’ surnames). This article discusses a specific minimax problem: to find a ball of the smallest volume containing a given finite set of points. It is called the Sylvester problem and is a special case of the Chebyshev center of the set problem. The convex quadratic programming problem with simplex constraints is compared to the Sylvester problem. To solve this problem, the article suggests using a variant of the MDM algorithm. With its help, a minimizing sequence of plans is built, such that only two components differ from neighboring plans. The numbers of these components are selected based on certain optimality conditions. The weak convergence of the obtained sequence of plans is proved, from which follows the norm convergence of the corresponding sequence of vectors to the only solution of the Sylvester problem. Four typical examples on the plane are given.
ON NEW CLASSES OF SOLUTIONS TO THE PROBLEM OF σ-COMMUTATION (σ ̸= 0, ±1) OF THE TOEPLITZ AND HANKEL MATRICES WITHIN THE FRAMEWORK OF A UNIFIED APPROACH
Authors: Chugunov V. N , Ikramov Kh. D
Published: December 2024

In the previous work by the authors, a unified approach to the design of pairs of matrices (𝑇, 𝐻) solving the problem of σ-commutation of Toeplitz and Hankel matrices was proposed. In this paper, this approach is applied to the derivation of new classes of solutions.
THE USE OF UNIVERSAL FAST TRIGONOMETRIC INTERPOLATION AND EXTRAPOLATION TO DETERMINE THE COORDINATES OF THE LAUNCH POINT OF THE AIRCRAFT
Authors: Chernyshov A. D , Nikiforova O. Yu , Goryainov V. V , Rukin I. G
Published: December 2024

The basics of fast trigonometric interpolation are given for nonperiodic functions, making it possible to obtain an approximate solution with high accuracy. Formulas are obtained to calculate the coordinates of the launch point of an aircraft with high accuracy due to the simultaneous application of the method for universal fast trigonometric interpolations and the method for extrapolations at the ends of a certain specified segment. Numerical experiments show that after the launch of the first aircraft the coordinates of the launching mechanism can be determined in 7 seconds with an accuracy up to 10−17 m.
GENERALIZATION OF THE SCATTERING MATRIX METHOD TO PROBLEMS IN NONLINEAR DISPERSING MEDIA
Authors: Belov A. A , Dombrovskaya Zh. O
Published: December 2024

In recent years, much attention has been paid to integrated photonics devices based on nonlinear media. A generalization of the transfer matrix method to problems in plane-parallel layered media with quadratic and cubic nonlinearity is proposed. Incident radiation can be either a monochromatic wave or a non-monochromatic pulse. Previously, such problems could only be solved using grid methods. The proposed approaches significantly expand the field of applicability of matrix methods and radically exceed the efficiency of the known grid methods.
COMPARATIVE ANALYSIS OF THE INFLUENCE OF SURFACE QUANTUM EFFECTS ON THE OPTICAL CHARACTERISTICS OF NANOPARTICLES OF ALKALI AND NOBLE METALS
Authors: Eremin Yu. A , Lopushenko V. V
Published: December 2024

Based on the discrete element method, a mathematical model has been built making it possible to carry out a comparative analysis of the influence of volume and surface quantum effects on the optical properties of alkali and noble metal nanoparticles located in a dense external environment. A significant difference in the manifestations of volume and surface quantum effects in alkali metal nanoparticles has been detected. In particular, in such particles plasmon resonance in the case of volume quantum effect shifts to the shortwave region (blue shift) while the surface effect leads to a shift to the longwave region (red shift). It is shown that this shift significantly depends on the density of the environment and can reach 50 nm in the spectral region.
NUMERICAL DIAGNOSTICS OF THE DESTRUCTION OF A SOLUTION OF ONE THERMOELECTRIC SEMICONDUCTOR MODEL
Authors: Korpusov M. O , Shafir R. S , Matveyeva A. K
Published: December 2024

A system of equations with nonlinearity with respect to the potential of the electric field and temperature is proposed, describing the heating process of semiconductor elements of an electric board, and over time, thermal and electrical “breakdowns” may occur. The paper considers a method for the numerical diagnosis of solution destruction. In the process of numerical investigation of this problem, an approach was used based on the reduction of the initial system of partial differential equations to a differential algebraic system, followed by the solution of this system using a one-stage Rosenbrock scheme with a complex coefficient. Numerical diagnostics of the destruction of the exact solution of the specified system of equations was based on the method for calculating a posteriori asymptotically accurate error estimate obtained when calculating an approximate solution on successively thickening grids. Numerical estimates of the moment of destruction are obtained for various initial conditions.
ON AN APPROACH TO IMPROVING THE ACCURACY AND EFFICIENCY OF THE ROMB METHOD FOR SOLVING THE UNSTEADY HEAT CONDUCTION EQUATION
Authors: Moiseev N. Ya
Published: December 2024

A modification of the ROMB method is presented for numerically solving unsteady nonlinear heat conduction equations. The modified difference schemes are conservative and, for smooth solutions, approximate the model differential equations with constant coefficients with second-order accuracy in both time and space. First differential approximations are provided for the modified difference schemes, enabling the assessment of approximation errors in the schemes.
ESTIMATES OF SOLUTIONS FOR A CLASS OF NONAUTONOMOUS SYSTEMS OF NEUTRAL TYPE WITH CONCENTRATED AND DISTRIBUTED DELAYS
Authors: Matveeva I. I
Published: December 2024

A class of systems of nonautonomous differential equations of neutral type with concentrated and distributed delays is considered. By using a Lyapunov–Krasovskii functional, estimates are established imply whether the solutions are stable. In the case of exponential stability, estimates for the stabilization rate of the solutions at infinity are given.
COMPUTATION OF UNSTEADY SWIRLING FLOWS IN NOZZLES AND PIPES BY APPLYING A NEW LOCALLY IMPLICIT GODUNOV-TYPE SCHEME
Authors: Zaitsev N. A , Rykov Yu. G
Published: December 2024

A new class of numerical schemes for calculating unsteady swirling flows in nozzles and pipes based on compressible inviscid gas equations is presented. The main advantage of these schemes is their ability to efficiently handle unsteady problems with multiple scales. The construction of such schemes is based on the well-known Godunov approach, which involves calculating fluxes at the faces of computational cells (volumes) by solving auxiliary one-dimensional problems in the vicinity of each face and approximating conservation laws. The scheme switches from an explicit method to an implicit one for flux calculation based on an analysis of the current solution near the cell face. The scheme is absolutely stable and does not generate spurious oscillations. Its effectiveness is demonstrated in the calculation of unsteady swirling flows in nozzles and pipes. Specifics of setting up problems of this type are investigated, and options for proper problem formulation are proposed. Properties of the solution for swirling flows with a central body covering only part of the symmetry axis in the computational domain are also studied.
ON SPECTRAL PORTRAITS OF NEAREST NEIGHBOR GRAPH INCIDENCE MATRICES
Authors: Kislitsyn A. A
Published: December 2024

This paper explores the possibility of applying S.K. Godunov’s method of constructing spectral portraits of matrices to estimate the rank of special types of matrices that appear in various applications, such as nearest neighbor graph structure analysis, finite automata theory, and sparse matrix spectrum estimation. A computational algorithm for generating an ensemble of random distance matrices and the associated nearest neighbor graphs is described. Based on computational experiments, parameters of the vertex degree distribution of random nearest neighbor graphs are evaluated. These estimates are feasible because the distribution is independent of the random distance function and follows a multivariate normal distribution. It is proven that the rank of the incidence matrix of a nearest neighbor graph equals the total number of vertices with in-degree 0 and 1, and the rank distribution of such a matrix is derived. It is also shown that, in this context, a method based on analyzing the vertex degree distribution is highly effective for determining the matrix rank.
LOCALIZATION OF EIGENFUNCTIONS OF THE DIRICHLET PROBLEM NEAR A CONTOUR AT THE BOUNDARY OF A THIN DOMAIN
Authors: Nazarov S. A.
Published: December 2024

We consider the spectral Dirichlet problem for the Laplace operator in a thin three-dimensional domain of a variable thickness which admits a maximum value at a smooth closed contour either inside the longitudinal cross-section, or at its boundary. We find out asymptotic expansions of the eigenvalues which involve eigenvalues of the harmonic oscillator at the axis or the half-axis as well as of a certain second order ordinary differential equation at the contour. The eigenfuctions are localized in the vicinity of the contour.
SOLVABILITY OF NONLINEAR BOUNDARY VALUE PROBLEMS FOR DIFFERENTIAL EQUILIBRIUM EQUATIONS OF NON-FLAT TIMOSHENKO TYPE SHELLS OF NON-ZERO GAUSSIAN CURVATURE IN ISOMETRIC COORDINATES
Authors: Timergaliev S. N.
Published: December 2024

We study the solvability of a boundary value problem for a system of five nonlinear second-order partial differential equations under given nonlinear boundary conditions, which describes the equilibrium state of elastic non-flat inhomogeneous isotropic shells with loose edges in the framework of the Timoshenko shear model, referred to isometric coordinates.The boundary value problem is reduced to a nonlinear operator equation with respect to generalized displacements in Sobolev space, the solvability of which is established using the principle of compressed mappings.
INTEGRATION OF THE NEGATIVE ORDER MODIFIED KORTEWEG–DE VRIES EQUATION WITH A LOADED TERM IN THE CLASS OF PERIODIC FUNCTIONS
Authors: Urazboev G. U. , Khasanov M. M. , Ismoilov O. B.
Published: December 2024

Spectral data of the Dirac operator with periodic potential are found. This operator is associated with the negative order modified Korteweg–de Vries equation with a loaded term. The obtained results make it possible to construct a solution to the negative order modified Korteweg–de Vries equation with a loaded term in the class of periodic functions using the inverse spectral problem method. The solvability of the Cauchy problem for an infinite system of Dubrovin–Trubovitz differential equations in the class of three times continuously differentiable periodic functions is proved.
Management of territorial risks of development and security of social-natural-technogenic systems
Authors: Bychkov I. V. , Taseiko O. V. , Postnikova U. S. , Moskvichev V. V. , Shokin Yu. I.
Published: December 2024

The relevance of the study is due to the need to provide the governing bodies of the constituent entities of the Russian Federation with tools that allow identifying key problems and priority areas for sustainable development of the socio-, eco- and technosphere of each territory, taking into account the characteristics of natural and geographical conditions, industrial potential, population, and infrastructure. An approach to constructing a mathematical model for managing territorial development risks is proposed using municipalities as an example. A municipality is considered as a socio-natural-technogenic system characterized by a set of basic risks of the socio-, eco- and technosphere, and the security of the socio-natural-technogenic system is a property of a territorial entity taking into account interrelated development risks. The authors argue that reducing complex risk is possible by increasing the security of the territory. Quantitative assessments of the level of complex risk for three large cities of the Siberian Federal District were made, and the values of risk change with an increase in security were obtained.
“I am a happy person because my job and hobby coincide”. To the 90th anniversary of the birth of academician N.A. Plate
Authors: Maksimov A. L. , Kalashnikova I. S.
Published: December 2024

The article is dedicated to the memory of the outstanding Russian scientist Nikolai Alfredovich Plate, whose ninetieth birthday is celebrated in 2024. The authors analyze his contribution to the development of polymer chemistry, his role as an organizer of science, his significance in the international cooperation of the Russian Academy of Sciences.
Formation specifics of engineering geological conditions in Belarus under the influence of erosion processes
Authors: Pavlovsky A. I. , Galkin A. N. , Krasovskaya I. A. , Shershnev O. V.
Published: December 2024

The article presents the results of a comprehensive study of the development conditions and features of water erosion manifestation in various natural and economic settings as an important condition of the formation of engineering geological features of the territory. The authors have established that the development, forms of manifestation and intensity of water erosion processes in the territory of Belarus, with all the diversity of natural and economic situations, are controlled by the energy potential of the relief, the basin structure of the territory and human economic activity. Engineering geological conditions were typified for the development of water erosion processes. The most complex engineering geological situations are observed within the marginal glacial uplands, which have a high energy potential of the topography, a two-rock type of ground massif, and a complex basin structure; as well as in areas of active economic development.
Physicochemical mechanics of disperse porous materials as a new approach to assessing mechanical stability of clay soils
Authors: Osipov V. I. , Sokolov V. N. , Karpenko F. S.
Published: December 2024

Data are presented on the discrepancy between theoretical calculations and experimental results on assessing the strength of fine dispersed bodies including clay soils. Physicochemical processes operating on the surface of dispersed particles are considered upon interaction of latter with water and the formation of adsorbed water films producing disjoining pressure. The presence of films exerting the disjoining effect controls the development of various types of contacts between soil particles in the course of lithogenesis, i. e., coagulational, transitional, and phase contacts. These contacts are the most important factors influencing the behavior of clay soils. The study dwells on the effect of contact types on the state, deformability and stability of clay soils under external impact. It is concluded that the assessment of clay behavior should be based on physicochemical mechanics, patterns of contact interactions in fine-grained soils, and statistical analysis of experimentally obtained parameters of the mechanical properties of clays.
INFINITE ALGEBRAIC INDEPENDENCE OF POLYADIC SERIES WITH PERIODIC COEFFICIENTS
Authors: Chirskii V. G
Published: December 2024

Consider sequences of integers 𝑎𝑛(𝑘,𝑗), 𝑘 = 1, … , 𝑇𝑗, 𝑗 = 1, … , 𝑚 such that 𝑎𝑛(𝑘,𝑗) = 𝑎𝑛(𝑘+,𝑇𝑗)𝑗 , 𝑗 = 1, … , 𝑚, 𝑘 = 1, … , 𝑇𝑗, 𝑛 = 0, 1, …, and consider the series 𝐹𝑗,𝑘(𝑧) = ∞ ∑ 𝑛=0 𝑎(𝑘,𝑗)𝑛 𝑛!𝑧𝑛, 𝑘 = 1, … , 𝑇𝑗, 𝑗 = 1, … , 𝑚. The conditions are established under which the set of series 𝐹𝑗,𝑘(𝑧), 𝑘 = 2, … , 𝑇𝑗, 𝑗 = 1, … , 𝑚 and the Euler series Φ(𝑧) = ∞ ∑ 𝑛=0 𝑛!𝑧𝑛 are algebraically independent over ℂ(𝑧) and for any algebraic integer γ ≠ 0, their values at the point γ are infinitely algebraically independent.
ON NUMERICAL BEAMFORMING FOR ACOUSTIC SOURCE IDENTIFICATION BASING ON SUPERCOMPUTER SIMULATION DATA
Authors: Plaksin G. M. , Kozubskaya T. K. , Sofronov I. L.
Published: December 2024

The paper is devoted to the method of numerical beamforming for processing spatio-temporal data obtained from supercomputer simulation of aeroacoustics problems, in order to localize a distributed acoustic source formed by interaction of turbulent flow and an aircraft or its elements in flight mode, and to determine its amplitude-frequency characteristics. Mathematically, the proposed method is based on solving the inverse problem of restoring the right-hand side in the Helmholtz equation for sources of monopole and dipole types. Compared to an analogue intended for the analysis of experimental measurements, the new method has significant advantages and allows generalization to the case of correlated sources. In the paper, the capabilities of the method are demonstrated by solving the problem of identifying an acoustic source that is generated by an upswept aircraft wing with deployed high-lift devices in landing mode.
«A SWARM OF NAMES»: FROM THE JUBILEE OF N. V. BUGAEV (1900) TO THE HONORING OF KOROBKIN IN ANDREI BELY’S NOVEL MOSCOW (1926)
Authors:   A. M. Gorky Institute of World Literature, Russian Academy of Sciences, Spivak Monika Lvovna
Published: December 2024

The episode of honoring Professor Korobkin in the novel Moscow is based on real events, reinterpreting the celebration of the publication of the 20th issue of Matematicheskij Sbornik magazine at the Moscow Mathematical Society, which grew into a benefit event for N. V. Bugaev, Andrei Bely’s father. The characters in the analyzed episode are real people, historical personae (under their actual surnames) and characters with fictitious names. The article lists the participants of N. V. Bugaev anniversary who were subsequently introduced into the novel under their own names. The analysis of the characters presented under fictitious names leads to their real prototypes from the milieu of Professor N. V. Bugaev or Andrei Bely.
S. A. SOKOLOV’S BUREAU OF PROVINCIAL PRESS AS A CONDUIT BETWEEN MODERNIST WRITERS AND THEIR READERS
Authors:   European University at St. Petersburg, Glukhovskaia Elena Aleksandrovna
Published: December 2024

The article traces the history of the Bureau of Provincial Press, which was organized in Moscow in late 1907. Using the newspaper data and archival sources, the article reconstructs the history of the Bureau’s creation and identifies both the writers from the metropolis and the provincial newspapers that collaborated with it. Even though the Bureau lasted for less than a year, it made a major contribution to the popularization of Modernist literature among a wide readership.
AN UNKNOWN ST. PETERSBURG FEUILLETON BY I. A. GONCHAROV
Authors:   Institute of Russian Literature (Pushkinskij Dom), Russian Academy of Sciences, Gus’kov Sergei Nikolaevich ,   National Research University Higher School of Economics (St. Petersburg)
Published: December 2024

The article provides the attribution of the feuilleton, published in the newspaper Severnaya Pochta. The researcher proves I. A. Goncharov’s authorship by a set of factors: his life circumstances, genre, thematic and textual parallels with his other texts.
THE “GRIBOEDOV EPISODE” IN THE SECOND CHAPTER OF “A JOURNEY TO ARZRUM”
Authors:   The Institute of Russian Literature (Pushkin House) of the Russian Academy of Sciences, Fomichev Sergei Alexandrovich
Published: December 2024

The article substantiates (as opposed
to the point of view of A. A. Dolinin) the
fi ctionality in Pushkin’s description of his
meeting in 1829 with the ashes of Griboyedov in Gergery, which, according to
rumors, became known to Bulgarin as
early as 1830. The ubiquitous journalist
could have well found out about Pushkin’s
intention to publish (following the article
“Georgian Military Road”) in Literaturnaya Gazeta a corresponding article (which, apparently, was not censored at
that time) in order to descredit Bulgarin’s
memoirs about Griboyedov. It is no coincidence, therefore, that before the opening
words of the Griboyedov episode in the
autograph of “A Journey to Arzrum” the
words “Article II” appeared at the margins (presumably in Pletnev’s hand).
HOW A “LITTLE MASTERPIECE” IS MADE NOTES ON PUSHKIN’S MADRIGAL “THE LAST FLOWERS ARE DEARER...”
Authors:   The Institute of Russian Literature (Pushkin House) of the Russian Academy of Sciences, Kardash Elena Valerievna
Published: December 2024

This article presents a detailed historical and literary commentary on Pushkinʼs madrigal ”The Last Flowers Are Dearer...” (1825). The author highlights a
range of pretexts and probable sources of
the poem and traces its relations to the
18th and early 19th century French cultural
tradition (“the language of fl owers”, adaptations of Ovid’s poem “Ars amatoria”,
libertine narrative), thus demonstrating
how it becomes for the poet an instrument
to transform the standard elegiac plot.
Thus, the madrigal is considered in the
context of critical and literary debates of
the fi rst half of the 1820s on the ways to
overcome the elegiac canon.