bluuebunny/crossref_metadata_2025 huggingface dataset:
Individual-based numerical experiment to describe the distribution of floating kelp within the Southern Benguela Upwelling System
Authors: Coppin Ross , Rautenbach Christo , Smit Albertus J.
Published: September 2024

Kelps are resilient organisms, capable of thriving in high-energy wave environments. However, when hydrodynamic drag forces exerted by the wave environment exceed the kelps’ structural limits, individuals become dislodged. Floating kelps generally follow ocean currents, traveling long distances until air-filled structures fail or the epibiont load becomes too great, causing them to sink to the seafloor. The ability of kelp to disperse over vast offshore and nearshore systems makes them important for organic subsidy and as a dispersal vector for marine organisms. Previous research on dislodged macroalgae focused on context-specific rafts, limiting insights into the broader ecological role of floating kelp. This study employed a site-specific Lagrangian trajectory model to describe the spatial distribution of floating Ecklonia maxima along the South African coastline. The model incorporated buoyancy and sinking using site-specific morphological data. Findings revealed that the distribution of floating E. maxima is influenced by oceanographic conditions, and seasonal patterns were also evident. Mesoscale features played a vital role in kelp accumulation on the surface and seafloor and acted as barriers to dispersal. This study offers essential insights into kelp’s role as an organic subsidy and provides numerical evidence for kelp’s potential as a carbon sink, contributing to a better understanding of kelp ecosystems and their ecological functions.
Static perfect fluid spacetime on Riemannian manifolds admitting concurrent-recurrent vector field with Bach tensor
Authors: Praveena M. M. , Kumara H. Aruna , Arjun C. M. , Siddesha M. S.
Published: September 2024

In this paper, we first consider the

𝕊
⁢
ℙ
⁢
𝔽

{\mathbb{SPF}}

equation on a Riemannian CRVF-manifold M and show that either M is Einstein or the potential function is pointwise collinear with ζ on an open set U of M. Next, we show that if a Riemannian CRVF-manifold M is the spatial factor of a

𝕊
⁢
ℙ
⁢
𝔽

{\mathbb{SPF}}

with a Batch tensor then it is a Batch flat space-time manifold.
Development of gelatin nanoparticles for positron emission tomography diagnosis in pancreatic cancer
Authors: Sugo Yumi , Kimura Atsushi , Koizumi Tomoya , Oyama Kotaro , Taguchi Mitsumasa
Published: September 2024

Pancreatic cancer remains difficult to diagnose using currently available imaging probes. Thus, this study aimed to develop a novel imaging agent for the diagnosis of pancreatic cancer using positron emission tomography (PET). Specifically, this study explores gelatin-based nanoparticles fabricated via radiation-induced crosslinking, as gelatin is known for its ability to produce biocompatible materials. Aqueous gelatin solutions were irradiated with γ-rays to produce nanoparticles with average diameters of 5–20 nm via a radiation crosslinking technique. The gelatin nanoparticles were labeled with 64Cu, exhibiting negative surface potentials. Furthermore, the nanoparticles were evaluated in vivo by injecting them into pancreatic tumor-bearing mice. Notably, the nanoparticles accumulated in the tumors. Hence, 64Cu-labeled gelatin nanoparticles show promise as a platform for next-generation PET imaging agents for pancreatic cancer.
Cationic Gemini surfactants: a review on synthesis and their applications
Authors: Naik Bharti , Paranjpe Susmita S. , Madankar Chandu S.
Published: September 2024

The molecules of Gemini surfactants are dimeric and consist of two monomeric surfactant units linked by a spacer. Among them, cationic Gemini surfactants have a wide range of application in various industrial sectors such as pharmaceuticals, home and personal care, corrosion inhibition, etc. Various methods of synthesis have been investigated and tested for the synthesis of cationic Gemini surfactants. The surface properties of Gemini surfactants are highly dependent on various factors like spacer, headgroups, counterions, etc. The cationic Gemini surfactants have lower CMC values as compared to their monomeric analogues. This review highlights the different methods for the synthesis of cationic Gemini surfactants and the applications of these surfactants in different fields are presented.
Recollections of parental psychological control: Associations with dysfunctional individuation, depressive symptoms, and shame and guilt
Authors: Rodger Jillian , Kealy David
Published: September 2024

Excessive parental psychological control may disrupt individuals’ psychosocial development, thus influencing later psychological problems. The present study tests a retrospectively worded Parental Control and Disrespect Scale (PCDS) to examine factor structure and model fit as well as associations with individuation-related difficulties and negative affect. Study measures were completed by 482 adults at a single time-point. Confirmatory factor analysis suggested acceptable model fit of the retrospectively worded PCDS. PCDS scores were significantly associated with dysfunctional individuation, depressive symptoms, and generalized shame and guilt, remaining significant after controlling for age, gender, and neuroticism. Moderation analysis indicated certain associations as stronger among female participants, such that dysfunctional individuation was lower at decreased levels of parental control among women, while generalized guilt was higher at increased parental control among women. Findings support the retrospective use of the PCDS, indicating links between parental psychological control, individuation-related difficulties, and negative affect problems.
Relentless Hope in Action
Authors: Baldiwala Jehanzeb , Shetty Raviraj
Published: September 2024

In this article we share our understandings of relentless hope; what it looks like when it is practiced and what that makes possible for people and communities, through stories that draw upon our clinical and community engagements. These stories provide an opportunity for those in the space of mental health, community engagements, and advocacy to reflect on hope as little actions that are performed in collaboration with others, imagination as a way to create and hold onto hope, and the construction of relentless hope as a collective movement.
A tale of two sisters – delayed diagnosis of genetic hyperinsulinaemic hypoglycaemia
Authors: Stringer F , Preston C , MacIsaac R , Inchley F , Rivera-Woll L , Farrell S , Sachithanandan N
Published: September 2024

Congenital hyperinsulinism is the leading cause of persistent hypoglycaemia in infants and children; however, it is uncommon to be diagnosed in adulthood. We describe the cases of two sisters who presented with hyperinsulinaemic hypoglycaemia aged 47 and 57 years old, who were subsequently diagnosed with compound heterozygous likely pathogenic variants in the ABCC8 gene, a known cause of monogenic congenital hyperinsulinism. We discuss the typical presenting features, investigation findings, and treatment strategies for patients with this condition.

Learning Points

Congenital hyperinsulinism is a rare cause of hyperinsulinaemic hypoglycaemia diagnosed in adulthood.

Clinical presentation is similar to an insulinoma, and imaging modalities may assist in differentiation.

There are minimal medical therapies currently available for patients non-responsive to diazoxide (such as those with ABCC8 and KCNJ11 variants).

Continuous glucose monitoring can be helpful in giving patients autonomy in managing their disease, as well as relieving anxiety and fear associated with hypoglycaemia.
Geldschöpfung und Geldpolitik im Euroraum: Inwieweit ist Geldpolitik zugleich Strukturpolitik?
Authors: Walter Johann
Published: September 2024

Geschäftsbanken entscheiden darüber, in welchem Umfang und an welcher Stelle im Wirtschaftskreislauf Geld in Umlauf gelangt bzw. wer neues Geld als erstes bekommt (monetäre Allokation). Allerdings steuern geldpolitisch zuständige Zentralbanken, indem sie die Geschäftsbanken zu bestimmten Konditionen mit Zentralbankgeld versorgen. Der Beitrag analysiert den Mechanismus der Geldschöpfung und die Potenziale der Geldpolitik im Euroraum – besonders auch mit Blick auf die Frage, inwieweit Geldpolitik im Sinne einer Struktursteuerung wirkt.
Green Branding
Authors: Kreutzer Ralf T.
Published: September 2024

Im Zuge der nachhaltigen Transformation von Unternehmen kommt dem Green Branding eine Schlüsselrolle zu. Schließlich geht es darum, die „Grünwerdung“ eines Unternehmens über seine Markenführung nach außen zu tragen. Hierbei sind die nachfolgend beschriebenen Aspekte zu berücksichtigen.
Auswirkungen des "demografischen Wandels" auf Betriebe
Authors: Meurer Cornelia , Becker Fred G.
Published: September 2024

Der „demografische Wandel“ hat stark an Fahrt aufgenommen und ist für viele Betriebe Realität. Im Mittelpunkt der Diskussionen steht der Arbeitsund Fachkräftemangel. Nach der Skizzierung der Vorgeschichte des demografischen Wandels zeigt der Artikel dessen quantitativen und qualitativen Facetten auf. Das Konzept der informatorischen Fundierung, mit dem ein spezifischer Betrieb systematisch die Auswirkungen erfassen kann, wird vorgestellt und angewendet. Damit soll gleichzeitig demonstriert werden, wie hilfreich betriebswirtschaftliche Konzepte (auch aus einem Lehrbuch) sein können.
How well can sound tomograms characterize inner-trunk defects in beech trees from a burned plot?
Authors: Musat Elena C.
Published: September 2024

In recent years, forest fires have become increasingly common, but also more damaging phenomena. These aspects are reflected in significant economic losses that affect the quality and quantity of wood volumes that can be used for industrial processing. For this reason, knowing the quality of the wood is important, especially in fire-affected trees. Because visual analyses cannot always reflect the quality of the wood inside the trunk, the present research aimed to evaluate the extent to which modern techniques based on the transfer of sounds can identify internal wood defects. In this sense, 42 tomograms made from beech trees affected by a litter fire were compared with the relative resistances of the wood to drilling and with the real condition of the wood inside the trunk, as made visible through the growth cores taken with a Pressler drill. From the cumulative interpretation of the results, it was found that the trees affected by the fire have serious defects, which lead to the downgrading of the wood and are not reproduced by the tomograph to their true extent. Conversely, sound transfer speeds through wood are influenced by the presence of beech red heartwood, which leads to an increase in sound transfer speeds through wood, and that can alter the accuracy of the tomogram.
Estudiantes sordos como lectores de una novela breve en español: modalidades de lectura individual y de conversación colectiva
Authors: Lapenda María Eugenia
Published: September 2024

Neste artigo é apresentada uma investigação sobre a abordagem de um conto em uma sala de aula de uma escola plurilíngue de Educação Especial em Língua de Sinais Argentina (LSA) e Espanhol na província de Buenos Aires, Argentina. Interessou-me saber como doze crianças surdas do Ensino Básico, com diferentes desempenhos linguísticos nessas línguas, procederam ao texto ficcional em espanhol e também as características da sua posterior participação numa conversa entre leitores. Seguindo uma metodologia etnográfica (por observação e registro), baseada em gravações e anotações feitas em aula e fora dela, xx, descrevo e analiso as estratégias e ações dos participantes da aula para avançar na construção do sentido do texto para xxx. A exploração demonstra o impacto positivo de uma variedade de recursos multimodais e de translinguagem durante leituras individuais e coletivas para desenvolver interpretações cada vez mais baseadas na história com maior atenção à trama do que a detalhes insignificantes e, ao mesmo tempo, para serem “liberados” dele. Da mesma forma, permite reconhecer o poder do ensino na promoção da autonomia na seleção e utilização de estratégias pessoais em complementaridade com contribuições grupais para a construção do sentido dos textos.
Análisis de los Rasgos Distintivos en la Lengua de Señas Peruana (LSP)
Authors: Raico Morales Giovana
Published: September 2024

This research focuses on the following objectives: 1) to document and describe the distinctive function that has phonological value, and 2) to identify the distinctive features in Peruvian Sign Language (PSL) in the area of manual configuration (point of articulation, movement, space) and non-manual features. In this sense, it contributes to the study of one aspect of the phonology of PSL. For this purpose, filming was carried out and language users were consulted. The methodology included fieldwork with a group of deaf people in Lima. This exploration is pioneering for LSP, since it constitutes a first effort to provide empirical evidence on the distinctive functions of manual forms in this system. To this end, it is shown that sign language has a phonology whose basic elements (distinctive features) can be identified using the same methods as in spoken languages.
La enseñanza de la lengua de señas ecuatoriana y su adaptación al Marco Común de Referencia Europeo en Ecuador
Authors: Banet Ponce Jorge Luis , Matts Janine Marie
Published: September 2024

This paper examines Ecuadorian Sign Language teaching from its beginning to the present time and its adaptation to the Common European Framework of Reference for languages by a higher education institution. It reviews the history of language teaching, the history of sign language teaching in the Ecuadorian context, and finally it proposes suggestions for its improvement. It argues that sign language, like any other natural language, should be taught communicatively by appropriately trained language teachers to obtain the best results. These teachers may be native or non-native, as it has already been argued in the teaching of other foreign and second languages. Furthermore, the teaching of Ecuadorian Sign Language should adhere to the guidelines of the Common European Framework of Reference for Languages, just as oral languages in the Ecuadoriancontext do.
Del ruido a la seña. Notas para la formación de una representación del sordo desde los enfoques histórico y cultural
Authors: Cruz Cruz Johan Cristian
Published: September 2024

The purpose of this study is to provide a perspective on the representation of the Deaf, considering historical and cultural aspects. This will contribute to a better understanding of the experience of deaf people and promote a more inclusive and respectful representation of this community. Theoretical elements are presented from the social representations that allow understanding the constitution of the concepts of deaf and deafness. We start from a qualitative and hermeneutic methodology, through a critical reflection on the representation of deaf people in contemporary society and its impact on inclusion and participation. We analyze stereotypes and prejudices that persist and identify progress and challenges in promoting an inclusive culture that is committed to respect for deaf people and diversity, which is reflected in the construction of two sections that analyze the evolution of the concept of collective representation to social representation and social representations of the deaf and deafness. We conclude that the study of Deaf culture and its history can provide insight into the experiences and perspectives of Deaf people and their communities, and promotes greater understanding and acceptance of Deafness as a cultural identity.
The inhomogeneous Riemanian boundary – value problem with infinite index of the logarithmic order ρj ≥ 1 for complex Dini-Lipshitz contour
Authors: Alekna Petras
Published: September 2024

Special choosing entire functions, the general solution of the problem in the class of bounded and analytic functions is obtained.
Algebraic version of convex combination patches
Authors: Karčiauskas Kęstutis
Published: September 2024

There is not abstract.
Some decidable classes of modal logic S5
Authors: Norgėla Stasys
Published: September 2024

There is not abstract.
Analysis of the model reactor dynamics
Authors: Bučys Kostas , Švitra Donatas
Published: September 2024

There is constructed a model of nuclear reactor dynamics with delay in feedback line "power­reactivity" including six groups of delayed neutrons. Using D-partitioning method there is analysed the characteristic quasi-polynomial disposition of roots on complex plane.
Models of vehicle motion
Authors: Listopadslcis Narimantas
Published: September 2024

There is not abstract.
A tool for the analysis of the efficiency of a parallel LU factorization algorithm
Authors: Čiegis Raimondas , Starikovičius Vadimas
Published: September 2024

This paper considers issues on the design of a tool for the analysis of a parallel LU factorization algorithm. The costs of data communication are included into the theoretical model. Problems of defining the optimal number of processors and efficient data distributions among processors are investigated. Results of computational experiments are given.
The probabilistic number theory and continuum
Authors: Stakėnas Vilius
Published: September 2024

Let bn be a sequence of real numbers increasing unboundedly, α > 0 and B(n, α) = [bn α]. The conditions on bn are considered, which imply the regularity of distribution of B(n, α) in arithmetic prog­ressions for almost all α > 0. This allows to develop a piece of probabilistic number theory on sequences B(n, α) for almost all α > 0.
Characterization of the typology of producers in the “sembrando vida” program in Oaxaca, Mexico
Authors: Reynolds Chávez Marco Antonio , Burela Ángel Capetillo , Zetina Lezama Rigoberto , Guerra Mariano Morales , López López Juan Antonio
Published: September 2024

In Mexico, research work documented at plot in the field or producer level is uncommon and with limited information, due to the fact that it is expensive and requires specialized personnel. This research work carried out by the National Institute of Forestry, Agriculture and Livestock Research (INIFAP) and financed by the National Council of Humanities, Science and Technology (CONAHCYT) was based on a field diagnosis to determine the description of the typology of the participating "sowers'' producers enrolled in the Sembrando Vida Program (PSV), of the Federal Goverment of Mexico belonging to the state of Oaxaca, and thus, be able to implement strategies for training and follow-up attention on a massive scale. A total of 383 sample surveys were analyzed from a population of 37,719 small producers representing an estimated crop area of 56,578 hectares distributed in two regions of the state of Oaxaca. It is concluded that the diagnosis continues to be a fundamental information tool to identify and address more precisely and timely the problems at the farmer's plot level and with any type of crop. Another fundamental activity was the visit or technical visits to the territories that are representative of the regions in order to validate the information obtained. With the results obtained in this research, it was possible to address the main problems through personalized and directed technical assistance under the scheme of field schools (learning-by-doing) throughout the development of annual and fruit crops that the planters have in the MIAF within their PUPs (Small Production Units). Likewise, insert the main training needs at the express and consensual request of all program stakeholders: researchers-trainers, PSV technicians and sowers.
Glaciares, patrimonio biocultural Mapuche y estrategias de protección: el glaciar Pichillancahue en los Andes del sur de Chile
Authors: Pilquiman Vera Marisela , Ramírez Stepfanie , Rodríguez Jaramillo Clarena , Merino Espeso Alberto
Published: September 2024

En Chile los enfoques para la protección y ordenación de los glaciares se han ceñido a una categorización y caracterización desde el punto de vista técnico y científico, invisibilizando otras formas de conocimiento ligadas a la salvaguardia de los territorios. Poco se conoce sobre las prácticas de adaptación, relacionamiento, significados y saberes que los pueblos originarios atribuyen a los glaciares andinos. Justamente, en los Andes del sur de Chile, a partir de una investigación acción participativa desarrollada en territorio ancestral del pueblo Mapuche, donde se ubica el glaciar Pichillancahue, se ha buscado reconocer los saberes y prácticas de este pueblo respecto a dicho glaciar, para articularlos en una estrategia de protección de su patrimonio biocultural; en esta se funden y resignifican conocimientos científicos con su propio kimün (conocimiento), revelando respuestas locales y el potencial resiliente de las comunidades mapuche relacionadas a este glaciar. Todo esto, en un territorio que enfrenta conflictos y dinámicas territoriales diversas, producto del cambio climático, el estrés hídrico y la expansión del capital a través de nuevos ejes de acumulación como el turismo masivo.
Nutrition therapy in colorectal cancer patient with severe malnutrition: A case report
Authors: Made Kurnia Alvina  , Wirayanti Putu Diani
Published: September 2024

Background: Malnutrition in cancer patients generally, and in gastrointestinal cancer specifically, is common, that could be from the cancer itself or the treatment. Thus, it is necessary to follow special nutrition rules in patients with colorectal cancer. This study aims to see the progress of the nutritional status of cancer patients treated with special nutrition rules.
Case Description: A 72-year-old man was brought to the ER with the chief complaint of weakness, felt since 1 week ago. Other complaints are loss of appetite and liquid stool. History of weight loss is 12 kg in the last 6 months. He was diagnosed with colorectal cancer 6 months ago. The patient looks pale, with conjunctiva pallor, loss of subcutaneous fat in arms, trunk, and feet, and loss of muscle in the face, ribs, and shoulder. He was then admitted to the ward with a diagnosis of colorectal cancer with severe malnutrition. Nutrition therapy has been given since the beginning. The total energy was 2,100 kkal, with 80gr protein, 280gr carbohydrate, and 70gr fat. The patient was treated for 10 days. Clinically improved: the conjunctiva was no more pallor, arm circumference increased to 19cm, he had gained his appetite, was no longer dripping with norepinephrine, and no longer needed O2 supplementation (SaO2 in room air: 98%).
Conclusion: Cancer treatment causes side effects on nutrition status. It is essential to give special nutrition rules to patients with colorectal cancer. Cancer patients also suffer from inadequate food intake, reduced ability to digest food, and disturbed body homeostasis. Malnutrition, especially in cancer patients, could result in general weakening, lower immunity, prolonged recovery period, and lower tolerance to the side effects of cancer therapy. Early nutrition therapy has a good impact on the nutritional status of the cancer patient.
Implementation of TQM in The Context of Patient Satisfaction in Various Hospitals in Indonesia
Authors: Tedjakusuma Abigail Sulistyani , Wulansari Candra Fitri , Sinaga Grace Krisdayanti , Winata I Putu Arya , Muslimin Mun Randi , Fermina Oktaviana Linda , Pinesa Venda Happy , Veranita Mira , Purwadhi
Published: September 2024

Introduction: The quality of healthcare in Indonesia has become a crucial factor in ensuring the well-being and satisfaction of patients. In the face of complex challenges in organizing and improving the quality of services to meet the increasingly diverse needs of society, patient satisfaction is a key indicator in assessing service quality. Total Quality Management (TQM) has emerged as a promising approach to improving healthcare institutions' efficiency, effectiveness, and patient satisfaction. This review describes the relationship between TQM implementation and patient satisfaction levels in Indonesian healthcare institutions.
Method: Using the literature review method, this research systematically summarizes relevant findings, aiming to provide greater insight into the impact of TQM on patient experience. The literature examination included understanding the basic concepts of TQM, its principles, and experiences of its application in the context of healthcare institutions. The literature analysis also focused on previous studies addressing the relationship between TQM implementation and patient satisfaction.
Result: Total Quality Management (TQM) implementation significantly improves the quality of healthcare services and, in an indirect context, contributes to improved patient satisfaction. Measures such as active patient participation, effective communication, and a continuous focus on quality improvement have been shown to play a crucial role in increasing patients' positive perceptions of healthcare services.
Conclusion:  The implications of the results of this study provide direction for further research and contribute to the existing literature on healthcare management and quality improvement.
APAKAH CAMPUR KODE BAHASA PADA BALITA BAGIAN DARI LINGUISTIC NEO IMPERIALISM?
Authors: Faizin Barzan , Kalsum Nyimas Umi
Published: September 2024

Interaksi anak balita dengan game online dan tayangan YouTube akan berpengaruh terhadap sikap dan perilaku kebahasaan campur code dalam komunikasi sehari-hari dengan orang-orang di sekitarnya. Penelitian ini bertujuan untuk mengelaborasi jenis campur kode yang dipakai oleh anak beserta konteks tuturannya, dan mengungkap hegemoni bahasa Inggris terhadap bahasa lokal dan Indonesia. Metode yang dipakai dalam studi ini adalah deskriptif kualitatif dengan pendekatan sosiolinguistik untuk mendalami tuturan anak balita yang mencampurkan dua kode, dan pendekatan kritis untuk mengungkap dominasi kultural yang direpresentasikan dalam satuan kebahasaan campur kode. Hasil penelitian menunjukkan bahwa campur kode tipe Penyisipan menempati posisi teratas, yang diikuti campur kode tipe Pemanfaatan, Preferensi, Alternasi, dan terakhir Kongruen. Berdasarkan urutan pemakaian campur kode tersebut, paling tidak ada dua karakteristik pada aktivitas campur kode anak pertama, anak balita cenderung menyisipkan leksem bahasa asing dan gaul secara acak (manasuka) tanpa melihat konteks tuturan. Kedua, anak balita cenderung memilih leksem yang mudah diucapkan karena ia telah menghafalnya dari tontonan atau game yang berulang-ulang ia lihat di internet. Fenomena ini menegaskan berkembangnya neo-imperialsime bahasa karena dorongan yang kuat dari dalam masyarakat yang merasakan keuntungan ekonomis dari penguasaan bahasa Inggris dan rasa percaya diri penutur ketika mampu berbicara bahasa Inggris serta munculnya rasa rendah diri pada sebagian masyarakat Indonesia yang memiliki kemampuan bahasa Inggris yang rendah.
A comprehensive review: Advancements in nanomaterials on the risk prevention, detection, and elimination of mycotoxin contamination
Authors: Ganesan Lavanya , Balasubramanian Balamuralikrishnan , Kumaravel Sri Kalpana , Maluventhen Viji , Arumugan Maruthupandian
Published: September 2024

Mycotoxins are poison that filamentous fungi generate under specific conditions. Mycotoxins in food and feed have a detrimental effect on both human and animal health, resulting in significant financial losses for agriculture sector. Despite the continuing advancement of traditional approaches, modern research trends favor novel alternatives. Therefore, it is crucial to prevent mycotoxin contamination, which has raised concerns around the globe. Recent advancements in the management of mycotoxin contamination have been possible by the application of promising new nanomaterials. Mycotoxins have negative impacts on human health, but nanotechnology methods appear to be viable, efficient, and affordable solutions. This review elucidates information on the incidence and toxicology of mycotoxins. Nanotechnology’s potential for removal of mycotoxins is mentioned briefly. Then, attention is directed on using newly developed nanomaterials to regulate mycotoxin contamination, such as testing, production, inhibition, adsorption, and removal of mycotoxins. The issues regarding the toxicity, incidence, and management of mycotoxins are tentatively presented along with potential prospects for using nanotechnology to remove mycotoxins from food and feed.
Identifying the effect of subgrade layer thickness of soil stabilized with waste foundry sand and fly ash on bearing capacity
Authors: Gunarti Anita Setyowati Srie , Zaika Yulvi , Munawir As’ad , Suryo Eko Andi , Harimurti Harimurti
Published: September 2024

The issue of subgrade soil often involves unstable soil properties, such as low bearing capacity, susceptibility to expansion and shrinkage, and vulnerability to erosion and deformation due to traffic loads and weather conditions. Unstable subgrade soil can cause various infrastructure problems, including cracks, settlement, and damage to road surfaces. Therefore, stabilizing subgrade soil is an important step to ensure the reliability and longevity of highways. One effective and sustainable method for subgrade soil stabilization is by utilizing local waste materials. The use of local waste materials such as fly ash (FA) and waste foundry sand (WFS) not only improves the physical and mechanical properties of the soil but also helps reduce environmental impact by repurposing pollutants. This study aims to analyze the effect of the thickness of subgrade layers stabilized with FA and WFS on bearing capacity. The initial stage includes examining the physical and mechanical properties of natural soil and soil stabilized with FA and WFS. The waste content used is 9 % FA and 15 % WFS by dry weight of the soil. Subgrade modeling was conducted using a steel box measuring 60×60×60 cm with a soil thickness of 30 cm. Load testing was carried out on 5 layer variants that had undergone 4 days of curing. The study results found that the ultimate bearing capacity (qult) of 890 kPa was produced by the V4 layer, which is a subgrade with a 30 cm thick layer of soil stabilized with FA and WFS at a settlement of 6 mm. The bearing capacity ratio of 2.87 means that the subgrade with a 30 cm thick layer of soil stabilized with FA and WFS experienced an improvement in bearing capacity of 2.87 times that of the subgrade with untreated soil material. The results obtained can be applied in practice to the local geotechnical conditions of the project site in West Java, including natural soil properties and seasonal changes
Improvement the dielectric and impedance properties of Pb-free Bi0.5Na0.5TiO3-SrTiO3 piezoelectric materials modified by Fe2O3
Authors: Effendi Mukhtar , Rini Nugraheni Puspita , Kurniawan Candra , Cahyanto Wahyu Tri , Widanarto Wahyu
Published: September 2024

The focus of this study is on the Fe2O3-doped Bi0.5Na0.5TiO3-SrTiO3 piezoelectric material. This is important to find ecologically acceptable piezoelectric materials. This research aims to obtain a lead-free piezoelectric material because lead is a material that is not environmentally friendly. An alternative solution is a piezoelectric material based on BNT-ST, which in this case is doped with Fe2O3 material. The study of Fe2O3 doped Bi0.5Na0.5TiO3-SrTiO3 piezoelectric material prepared by the solid-state reaction method was carried out to determine the optimum composition of the material formed. Doping variations are 0; 2.5; 5; 7.5; and 10 in mol %. The examinations were performed using X-ray diffraction (XRD) spectroscopy, a Scanning Electron Microscope (SEM), and an LCR meter. The Fe2O3 doped Bi0.5Na0.5TiO3-SrTiO3 produced a new compound in the form of FeBi5Ti3O15-Na2Ti3O7-SrTiO3 with the crystal structure of cubic, orthorhombic, and monoclinic, as well as the increasing crystalline size with the addition of dopants, exclude at 5 mol % and 7.5 mol %. FeBi5Ti3O15-Na2Ti3O7-SrTiO3 also produces varying particle sizes, which are between 0.88–8.23 µm. From the obtained data, the optimum composition of Fe2O3 doped Bi0.5Na0.5TiO3-SrTiO3 was the 2.5 mol % of Fe2O3 due to it having the highest dielectric constant (er ) and temperature Curie (Tc ), and also the lowest material impedance (Z) with the er of 12.037 at Tc of 400 °C and Z of 135 kΩ. The high piezoelectricity, which is indicated by the high value of the dielectric constant and Curie temperature, is possible due to the presence of a greater number of sodium ions in the Na2Ti3O7 phase. Sodium ions are ions with good electrical storage capabilities. The increase in dielectric constant in the BNT-ST piezoelectric obtained by the addition of Fe2O3 shows that this material can be used as a substitute for lead-based piezoelectric materials so that it is secure for the environment. The piezoelectric material of BNT-ST doped with Fe2O3 earned from this research can be applied to obtain electricity with a optimal value when given mechanical pressure
Construction of mathematical models of thermal conductivity for modern electronic devices with elements of a layered structure
Authors: Havrysh Vasyl , Dzhumelia Elvira , Kachan Stepan , Maikher Viktoria , Rabiichuk Ihor
Published: September 2024

This paper considers a heat conduction process for isotropic layered media with internal thermal heating. As a result of the heterogeneity of environments, significant temperature gradients arise as a result of the thermal load. In order to establish the temperature regimes for the effective operation of electronic devices, linear and non-linear mathematical models for determining the temperature field have been constructed, which would make it possible to further analyze the temperature regimes in these heat-active environments. The coefficient of thermal conductivity for the above structures was represented as a whole using asymmetric unit functions. As a result, the conditions of ideal thermal contact were automatically fulfilled on the surfaces of the conjugation of the layers. This leads to solving one heat conduction equation with discontinuous and singular coefficients and boundary conditions at the boundary surfaces of the medium. For linearization of nonlinear boundary value problems, linearizing functions were introduced. Analytical solutions to both linear and nonlinear boundary value problems were derived in a closed form. For heat-sensitive environments, as an example, the linear dependence of the coefficient of thermal conductivity of structural materials on temperature, which is often observed when solving many practical problems, was chosen. As a result, analytical relations for determining the temperature distribution in these environments were obtained. Based on this, a numerical experiment was performed, and it was geometrically represented depending on the spatial coordinates. This proves that the constructed linear and nonlinear mathematical models testify to their adequacy to the real physical process. They make it possible to analyze heat-active media regarding their thermal resistance. As a result, it becomes possible to increase it and protect it from overheating, which can cause the destruction of not only individual nodes and their elements but also the entire structure
Revealing the influence of systemic risks in the development of enterprises on updating their investment position under entropy conditions
Authors: Mushnykova Svitlana , Prokhorova Viktoriia , Babichev Anatoliy , Abernikhina Iryna , Karlova Olena , Babiak Nataliia
Published: September 2024

This study identifies the impact of systemic risks on the company's strategic development prospects through attracting investments and ensuring their insurance protection. The company's strategic development model predetermines the level of its investment activity at various stages of the life cycle. This is important because there is an urgent need for the Ukrainian economy to attract foreign investment for the post-war reconstruction of the country. But there are objective difficulties associated with the complication of actualizing the investment position of enterprises in the leading sectors of the economy, taking into account the challenges and threats caused by the military aggression of the Russian Federation. Conditions of entropy, which indicate unpredictability and variability in the business environment, expose enterprises to great risks. It was determined that the investment position of the business entity should correlate with the strategic model of its development and represent a balanced mechanism. This has made it possible to reasonably systematize the risk of investment activities and approaches to their management. Statistical analysis became the basis for evaluating the dynamics of direct and capital investments in the leading sectors of the Ukrainian economy. The results gave grounds for asserting a significant deterioration of the investment climate in Ukraine as a result of the war. The level of direct and capital investments is low. We focused attention on the possibility of flexible adjustment of strategic development plans to unforeseen risks. The proposed recommendations, unlike existing ones, consist of a combination of state and market levers to stimulate investments in the economy of Ukraine. Existing military risks restrain the investment activity of stakeholders. Therefore, the conditions for the practical implementation of the mechanism of distribution and reduction of risks are the formation of insurance protection of investments for investors
Determining the aerodynamic performance of a high-speed unmanned marine wig craft
Authors: Dreus Andrii , Aleksieienko Serhii , Nekrasov Valerii
Published: September 2024

The study object of this paper is the aerodynamic processes during the movement of an unmanned aerial vehicle flying low over the underlying surface. The ground effect is known to enhance the aerodynamic performance of low-flying aircraft, particularly larger ones. However, this effect is most noticeable for large objects. Unmanned vehicles are typically characterized by their relatively compact geometry. This study explores the aerodynamic processes involved in the flight of a small-sized vehicle using the principle of dynamic support over a surface. The particular prototype of the unmanned aerial vehicle suggested by the authors has been examined herein. The aim of the study is to evaluate the aerodynamic forces affecting a small-sized unmanned high-speed vehicle that employs the dynamic principle of support over the surface (WIG craft) by using CFD modeling. In contrast to most available studies on the ground effect, a 3D problem statement was used in this work. Computational experiments have visualized the physical fields surrounding an aircraft in flight over the ground. This study determines how the distance from the surface affects the aerodynamic properties of a small-sized aircraft, as well as the height of the effective zone where ground effect influences the small-sized WIG craft within . It has been shown that approaching the surface leads to a shift in the center of pressure of the vehicle, which leads to a change in aerodynamic momentum. This phenomenon must be taken into account when designing a control system to provide a stable flight. The study's findings are directly relevant for the development of a type of unmanned vehicles that use the dynamic principle of support over the surface.
Devising a calculation method for modern structures of current-conducting elements in large electric machines in a three-dimensional statement
Authors: Tretiak Oleksii , Smyk Serhii , Kravchenko Stanislav , Smakhtin Serhii , Brega Dmytro , Zhukov Anton , Serhiienko Serhii , Don Yevhen
Published: September 2024

The jumpers of rotor pole-to-pole connections are highly stressed elements in a hydraulic generator structure. These assemblies often fail due to deformation that exceeds the size of an air gap. Existing methods do not take into account the thermal component and attempts to improve the design are not based on mathematical models that make it possible to perform calculations with an accuracy of more than 50 %. The method devised in this work makes it possible to obtain boundary conditions of the third kind on the basis of three-dimensional mathematical modeling of the ventilation system of the hydraulic unit without simplifications. The method accuracy is explained by taking into account the spatial thermal component. The heat transfer coefficient determined by this method in the pole-to-pole connections area was ~250 W/(m2·K). Using FEM, mathematical modeling of the thermal stress state of pole-to-pole connections was carried out, taking into account mechanical and thermal factors. This made it possible to design the improved connection structure with additional fastening elements, which make it possible to reduce the displacement to 0.03 mm, and the stress to 53 MPa at the rotor rotation frequency of 880 rpm. This design makes it possible to enable reliable operation of the hydraulic unit under the condition of increasing the rotor rotation frequency to overspeed with disconnected combinatorial dependence, provided that the actual stresses are 0.95 % of the material yield strength. The convergence of the values obtained by the proposed method and by the HSS method exceeded 99 %. The practical result is the proposals for the hydraulic generator design modernization
Building a fuzzy model for determining the level of social well-being of the population
Authors: Sharkadi Marianna , Dorovtsi Adam
Published: September 2024

This paper considers objects that affect the social security of the country. The complexity of such objects makes the development of computer systems in sociological research a difficult algorithmic task because of information uncertainty. Human thinking is based on inaccurate, approximate data, the analysis of which makes it possible to formulate clear decisions. In practice, there are usually no precise mathematical models that describe social objects. In such cases, it is advisable to use fuzzy mathematics as a tool for solving this problem. The main advantage of this approach compared to other artificial intelligence methods is the ability to interpret the results obtained. To assess the level of social well-being of the population, we used the mathematical apparatus of fuzzy set theory and fuzzy inference. The study is based on the OECD Better Life Index, which was developed by the Organization for Economic Cooperation and Development (OECD) to help countries assess and improve the quality of life of their citizens. In the course of the study, a fuzzy inference system was built to measure the social well-being of the population based on the indicators of the OECD Better Life Index. Since determining the level of social well-being is a complex task, a hierarchical structure with two main groups of social well-being indicators was constructed to simplify it. The resultant system evaluates each social indicator included in the OECD’s Better Life Index. Using the fuzzy inference model built, it was possible to assess the social well-being of the country’s population in a simple and transparent way in comparison with the OECD member countries. The results of the study make it possible to understand which indicators of social well-being of the country’s population are desirable or need to be improved in the future
Segmentation of image from a first-person-view unmanned aerial vehicle based on a simple ant algorithm
Authors: Khudov Hennadii , Hridasov Illia , Khizhnyak Irina , Yuzova Iryna , Solomonenko Yuriy
Published: September 2024

The object of this study is the process of image segmentation from the First Person View (FPV) of an unmanned aerial vehicle (UAV). The main hypothesis of the study assumes that the use of a simple ant algorithm could ensure the necessary quality of the segmented image.
The segmentation method, unlike the known ones, takes into account the number of ants in the image, weight, initial amount and evaporation rate of the pheromone, the "greediness" of the algorithm and provides:
– preliminary selection of individual channels of the Red-Green-Blue (RGB) color space;
– preliminary placement of ants according to the uniform law;
– determining the routes of ants;
– taking into account the attractiveness of the route for each ant;
– change (adjustment) in the concentration of ant pheromones;
– calculation of the probability of movement (transition) of the ant on the movement route;
– determination of the objective function at the j-th iteration and its minimization;
– determining the coordinates of the route of movement (movement) of ants;
– verification of the fulfillment of the stop condition;
– determination of the best routes found by ants;
– calculation of the brightness of the pixels of the segmented image in each channel of the RGB color space;
– further combining the results of channel segmentation.
An experimental study of image segmentation from UAV FPV based on a simple ant algorithm was conducted. The specified object of interest on the segmented image has a certain structure, unevenness of the contours, and can be further used for decoding, categorization, etc. Unlike the object of interest, the background ("garbage" objects) in the segmented image do not have a stable structure and can be further filtered out.
It has been established that the segmented image by the known method based on the gradient module has a low contrast value, there are gaps in the segmented pixels of the object of interest. A segmented image using a method based on a simple ant algorithm is free from that drawback.
Identifying the evolution of through cracks in iron-reinforced hollow slabs under the influence of a standard fire temperature mode
Authors: Sidnei Stanislav , Myroshnyk Oleh , Kovalov Andrii , Veselivskyi Roman , Hryhorenko Kostiantyn , Shnal Taras , Matsyk Ihor
Published: September 2024

The object of this study is the fire resistance of reinforced concrete hollow slabs at the onset of the limit state of loss of integrity. The problem of accurate modeling of the formation and development of cracks in concrete was investigated.
The paper reports an analysis of the results of the stress-strain state of a reinforced concrete hollow slab during fire exposure for devising a method for evaluating the fire resistance of such structures upon the onset of the limit state of loss of integrity.
According to EN 1992-1-2, the determination of fire resistance of structures is provided by calculation methods, however, there is no such procedure for reinforced concrete hollow slabs. Many scientific works offer refined methods for evaluating only the loss of load-bearing and heat-insulating capabilities, leaving aside the issue of loss of integrity. Thus, this can lead to a biased evaluation of reinforced concrete hollow floor slabs according to the criterion of the limit state of loss of integrity, which in turn can put under a threat to the fire safety of buildings, which threatens the life and health of people.
According to the results of the calculation, a parameter has been determined, according to which the onset of the limit state of fire resistance, in particular, the loss of integrity, was established. Summarizing the damage distributions, it was assumed that in the case of reaching the critical plastic deformation of 2.5e-3 in concrete finite elements, they are excluded from the general set of finite elements. Thus, in the case of the formation of through cracks, the removal of finite elements is taken as a parameter to identify the onset of the limit state of loss of integrity. According to the results of the computational experiment, it was established that through cracks in a fragment of a reinforced concrete hollow slab are formed in 44 min. According to the results of the research, the method of evaluating the fire resistance of such structures based on the onset of the limit state of loss of integrity has been substantiated. Such a method could be applied during design, which provides an opportunity to determine the limit of fire resistance in reinforced concrete hollow slabs