bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigating the Effect of Heat Transfer Influenced by the Application of Wavy Corrugated Twisted Tape Inserts in Double Pipe Heat Exchangers
Authors: Kurhade Anant Sidhappa , Bhambare Parimal Sharad , Desai Vijay Pandurang , Murali Govindarajan , Yadav Rahul Shivaji , Patil Prashant , Gadekar Tushar , Biradar Ramdas , Kirpekar Swanand , Charwad Girish Anant , Waware Shital Yashwant
Published: October 2024

This study investigates the heat transfer and friction factor characteristics in a heat exchanger utilizing copper wavy (corrugated) twisted tape inserts. By inducing turbulent flow within the inner tube of the heat exchanger, these inserts generated increased turbulence, thereby enhancing heat transfer and causing a rise in pressure drop. The copper twisted tapes, with various twist ratios (TR=10.7, 8.5, 7.1), measured 1 meter in length and 14 mm in width. The heat exchanger's outer tube was made of mild steel, with an outer diameter of 0.0198 m and an inner diameter of 0.0142 m, while the inner tube was constructed of copper, with an outer diameter of 0.038 m and an inner diameter of 0.032 m. The overall length of the pipe-in-pipe heat exchanger was 1.4 m. Bulk mean temperatures were recorded at different positions for various water flow rates, and new correlations for the Nusselt number and friction factor were derived from the results for the twisted tape inserts. The Reynolds number ranged from 5000 to 17000. Comparative analyses revealed that the wavy twisted tape with a twist ratio of 7.1 provided the highest heat transfer rate, showing a 172% increase in the Nusselt number and a 32.11% increase in the friction factor relative to a smooth tube.
Implementation of ANFIS-based UPQC for Power Quality and Thermal Management Enhancement in the Distribution System
Authors: Veerendra Arigela Satya , Lakshmi Kambampati , Sekhar Chavali Punya , Kappagantula Sivayazi , Sazali Norazlianie , Kadirgama Kumaran
Published: October 2024

Conventional distribution systems generally operate with voltage and current waveforms being sinusoidal, though they slightly deviate from the ideal sinusoidal waveform, which is measured as distortion. The increase in power demand has led to the local generation and storage of power (Micro Grid systems). For its adoption, we need to implement smart grid architecture. Power electronics is a technologically sound way to limit different kinds of power quality (PQ) disturbances. It can also be used to control power flow, boost energy transmission capacity, enhance dynamic behavior and voltage stability, and ensure better power quality at distribution within established bounds. Unified Power Quality Conditioners (UPQC), one of the well-known Flexible AC Transmission System (FACTS) devices, are typically used to address problems in distribution systems such as voltage surges, flickers, neutral current reduction, and PQ. Additionally, thermal management is crucial for maintaining system stability and preventing overheating. While dealing with sensitive loads, a UPQC injects harmonics into the system, which can compromise system stability. This article describes an artificial neural network with harmonics elimination techniques for a modified UPQC connected with a Smart Grid. The performance of the proposed system is evaluated using MATLAB/Simulink software.
Evaluation of Elevated Temperature Oxidation of Higher Manganese Ni-Resist Alloy
Authors: Yaakob Khairul Ihsan , Mohd Rashidi Maarof  , Rosnizan Muhammad Aminuddin
Published: October 2024

Nowadays Nickel was used mostly in battery, elevated temperature application and also corrosive environment. The boost of electric and hybrid vehicle had maximized the usage of Nickel as main composition in alloying industry. As such the Nickel price was at peak and become volatile to interest manufacturer. Among affected compound is Ni-Resist alloy. In this study, an alloy known as ductile Ni-resist alloy was modified to minimize its processing cost by decreasing its Nickel weight percentage. The modification was investigated in order to reduce nickel usage in the alloying composition so the alloying process cost can be minimized. More than 12 wt % chromium and manganese were alloyed with 10 wt % nickel during melting stage. Then, the evaluation of properties, oxidation behavior and its microstructure were examined. The results indicated more carbide was formed which later decreased tensile strength at elevated temperature. Oxidation resistance increased with addition of Mn/wt%. After oxidation at 765oC for 25 hours, there are oxide layers visible on the changed alloy.
Kajian Virtual Etnografi pada Akun Facebook Komunitas Sejarah Cepu
Authors: Wibowo Wasis , Drina Intyaswati
Published: October 2024

Perkembangan teknologi komunikasi dan media sosial memudahkan distribusi informasi yang bersifat lokal ke segala penjuru sehingga dapat diakses secara luas. Penggunaan media sosial Facebook oleh komunitas Sejarah Cepu menyajikan dan mendistribusikan informasi tentang budaya dan sejarah di sekitar wilayah Cepu, Kabupaten Blora, Jawa Tengah, secara lebih detail dan beragam. Informasi yang disajikan melalui media sosial Facebook dapat diakses secara luas oleh siapa saja dan anggota komunitas Sejarah Cepu. Penelitian ini melakukan audit komunikasi Facebook Sejarah Cepu menggunakan metode virtual etnografi dengan data yang diperoleh melalui wawancara, observasi, dan studi pustaka. Peneliti menganalisis konten Facebook Sejarah Cepu, interaksi online di platform ini, dan umpan balik dari pengguna untuk menilai efektivitas platform ini dalam mengkomunikasikan sejarah dan budaya Cepu. Temuan penelitian menunjukkan bahwa Facebook Sejarah Cepu adalah alat yang efektif untuk mengomunikasikan sejarah dan budaya Cepu, tetapi ada beberapa area di mana platform ini dapat ditingkatkan.
Pengaruh Konflik Peran Ganda Dan Kompetensi Dimediasi Oleh Motivasi Kerja Terhadap Kinerja Pegawai (Studi Kasus Pada Pegawai Negeri Sipil Perempuan Di Lingkungan Setda Kabupaten Merauke)
Authors: Fenetruma Zaenab , Tuhumena Ruben , Liswandi Liswandi
Published: October 2024

Penelitian ini bertujuan untuk menganalisis pengaruh konflik peran ganda dan kompetensi terhadap kinerja pegawai baik secara langsung maupun tidak langsung melalui motivasi kerja sebagai variable mediasi. Populasi dalam penelitian ini adalah pegawai pada Setda Provinsi Papua yang berjenis kelamin wanita yang berjumlah 56 orang. Sedangkan untuk penentuan sampel dalam penelitian ini penulis menggunakan teknik sensus. Penelitian menggunakan pendekatan kuantitatif dengan metode survey dan menggunakan analisis data Partial Least Square (PLS). Namun sebelum analisis, terlebih dahulu dilakukan uji outer model melalui uji validitas dan reliabilitas. Selanjutnya melakukan uji Inner Model melalui uji R-Square (Coefficient of determination), dan F-Square (f2 effect size). Hasil penelitian menyatakan bahwa konflik peran ganda dan kompetensi berpengaruh positif dan signifikan terhadap motivasi kerja pegawai, selanjutnya diketahui pula konflik peran ganda berpengaruh negative terhadap kinerja, sedangkan kompetensi dan motivasi berpengaruh positif dan signifikan terhadap kinerja pegawai. Kemudian dari pengaruh tidak langsung diketahui bahwa motivasi kerja mampu memediasi konflik peran ganda dan kompetensi terhadap kinerja pegawai pada Setda Provinsi Papua.
Resilience of Space: Application of Text Driven Emotion in Urban Planning
Authors: Akhtaruzzaman Ahmed , Khanam Yearunnessa , Rahman Md. Saifur , Hossen Saikat Sakhawat , Islam Md. Tawshif
Published: October 2024

This study explores the spatial distribution of adaptive cycle phases in Meherpur District, with a particular focus on the rhythm of emotions within the community. By analyzing settlement patterns and incident distribution taken from newspaper, the study identifies key phases of the adaptive cycle—Release (Ω), Reorganization (α), Growth (r), and Conservation (K)— across the unions and paurashavas of Meherpur District. A GIS-based approach was used to map buffer zones and observe how each phase manifests within varying distances from the settlement center. The findings highlight significant fluctuations between release and reorganization phases, suggesting that the region is in a constant state of transformation and recovery. The study also reflects on how these spatial patterns affect resilience, with a particular emphasis on the emotional and psychological landscape of the local population. This comprehensive analysis provides valuable insights into adaptive management and regional development strategies in Meherpur, contributing to a more resilient and emotionally stable community.
Epidemiology, clinical features and predictors of mortality in patients with candidemia in a tertiary care hospital in Turkiye: a single-center retrospective study
Authors: Güngör Kültüral , Yulugkural Zerrin
Published: October 2024

Objective: We aimed to evaluate the epidemiology of candidemia among hospitalized patients and identify risk factors associated with mortality.
Materials and methods: The medical data of 81 adult patients with candidemia who were hospitalized between May 1, 2015 and May 1, 2016 constituted the study. We recorded vital signs, clinical characteristics, ward or intensive care unit (ICU) interventions, comorbidities, and biochemistry findings. To identify factors independently associated with 30-day mortality, a forward conditional inclusion model was used in multivariable logistic regression.
Results: The annual incidence of candidemia was 23 cases per 10000 individuals (0.23%). The three most frequently detected species were C. albicans (46.91%), C. parapsilosis (29.63%) and C. glabrata (8.64%). The 30-day mortality rate was 59.26% (n=48). Multivariable logistic regression showed that older age (OR: 1.037, 95% CI: 1.006 - 1.070, p=0.018), ICU admission (OR: 3.325, 95% CI: 1.132 - 9.766, p=0.029) and acute renal failure (OR: 3.383, 95% CI: 1.024 - 11.173, p=0.046) were independently associated with mortality.
Conclusion: We revealed an annual candidemia incidence of 0.23% and a notably high 30-day mortality rate at our center. Older patients, individuals admitted to the ICU, and those with renal dysfunction may face an elevated risk of mortality, underscoring the importance of close monitoring in these populations. Population-based studies are required to create new approaches to prevent and treat candidemia.
Multidimensional poverty in the Colombian paciﬁc: identiﬁcation, measurement and recent trends
Authors: Sánchez-Torres Roberto Mauricio
Published: October 2024

The Paciﬁc is the region of Colombia with the greatest economic lag and the lowest living standards of its population. The objective of this study is to investigate poverty in the Colombian Paciﬁc, taking as a reference the multidimensional approach, applying diﬀerent identiﬁcation methodologies and aggregation indicators. The main result is that despite the reduction in poverty between 2010 and 2018, it has not been systematic and has presented much more moderate levels than the situation in the rest of the country; in particular, the region has great deﬁciencies in education levels and access to health.
Toward a Self-consistent Evaluation of Gas Dwarf Scenarios for Temperate Sub-Neptunes
Authors: Rigby Frances E. , Pica-Ciamarra Lorenzo , Holmberg Måns , Madhusudhan Nikku , Constantinou Savvas , Schaefer Laura , Deng Jie , Lee Kanani K. M. , Moses Julianne I.
Published: October 2024

The recent JWST detections of carbon-bearing molecules in a habitable-zone sub-Neptune have opened a new era in the study of low-mass exoplanets. The sub-Neptune regime spans a wide diversity of planetary interiors and atmospheres not witnessed in the solar system, including mini-Neptunes, super-Earths, and water worlds. Recent works have investigated the possibility of gas dwarfs, with rocky interiors and thick H2-rich atmospheres, to explain aspects of the sub-Neptune population, including the radius valley. Interactions between the H2-rich envelope and a potential magma ocean may lead to observable atmospheric signatures. We report a coupled interior-atmosphere modeling framework for gas dwarfs to investigate the plausibility of magma oceans on such planets and their observable diagnostics. We find that the surface–atmosphere interactions and atmospheric composition are sensitive to a wide range of parameters, including the atmospheric and internal structure, mineral composition, volatile solubility and atmospheric chemistry. While magma oceans are typically associated with high-temperature rocky planets, we assess if such conditions may be admissible and observable for temperate sub-Neptunes. We find that a holistic modeling approach is required for this purpose and to avoid unphysical model solutions. Using our model framework, we consider the habitable-zone sub-Neptune K2-18 b as a case study and find that its observed atmospheric composition is incompatible with a magma ocean scenario. We identify key atmospheric molecular and elemental diagnostics, including the abundances of CO2, CO, NH3, and, potentially, S-bearing species. Our study also underscores the need for fundamental material properties for accurate modeling of such planets.
SPYGLASS. V. Spatially and Temporally Structured Star-forming Environments in the Cepheus-Hercules Complex
Authors: Kerr Ronan , Kraus Adam L. , Krolikowski Daniel , Bouma Luke G. , Farias Juan P.
Published: October 2024

Young associations record complete histories of star-forming events through their demographics and dynamics, and Gaia has greatly expanded our knowledge of these associations. We present the first structural and dynamical overview study of the Cep-Her Complex, which has recently emerged as the largest stellar population within 500 pc that still lacks substantial follow-up. We reveal that Cep-Her is not a singular association, but rather an amalgam of four, consisting of the older (τ > 100 Myr) open cluster Roslund 6, in addition to three dynamically coherent and highly substructured young associations that we focus on: Orpheus (25–40 Myr), Cinyras (28–43 Myr), and Cupavo (54–80 Myr). With 9552 ± 960 stars in Orpheus, 3872 ± 455 stars in Cinyras, and 8794 ± 1827 stars in Cupavo, all three are among the largest young associations within 500 pc, rivalling major associations like Sco-Cen. Our novel view of the ages and dynamics of these associations reveals evidence for sequential star formation in Cinyras, in addition to a multiorigin pattern of stellar dispersal in Orpheus that may hint to the presence of multiple clouds at formation. Dynamical simulations indicate that, while some embedded open clusters and central components of these associations are converging, they likely lack the mass necessary to capture one another and undergo hierarchical cluster assembly. Our results provide our first view of the complex star-forming environments that gave rise to the associations of Cep-Her, which will serve as important laboratories for future studies of star and planet formation.
Filamentary Molecular Cloud Formation via Collision-induced Magnetic Reconnection in a Cold Neutral Medium
Authors: Kong (孔朔) Shuo , Smith Rowan J. , Whitworth David , Hamden Erika T.
Published: October 2024

We have investigated the possibility of molecular cloud formation via the collision-induced magnetic reconnection (CMR) mechanism of the cold neutral medium (CNM). Two atomic gas clouds with conditions typical of the CNM were set to collide at the interface of reverse magnetic fields. The cloud–cloud collision triggered magnetic reconnection and produced a giant 20 pc filamentary structure that was not seen in the control models without CMR. The cloud, with rich fiber-like substructures, developed a fully molecular spine at 5 Myr. Radiative transfer modeling of dust emission at far-infrared wavelengths showed that the middle part of the filament contained dense cores over a span of 5 pc. Some of the cores were actively forming stars and typically exhibited both connecting fibers in dust emission and high-velocity gas in CO line emission, indicative of active accretion through streamers. Supersonic turbulence was present in and around the CMR filament due to inflowing gas moving at supersonic velocities in the collision midplane. The shocked gas was condensed and transported to the main filament piece by piece by reconnected fields, making the filament and star formation a bottom-up process. Instead of forming a gravitationally bounded cloud that then fragments hierarchically (top-down) and forms stars, the CMR process creates dense gas pieces and magnetically transports them to the central axis to constitute the filament. Since no turbulence is manually driven, our results suggest that CMR is capable of self-generating turbulence. Finally, the resulting helical field should show field reversal on both sides of the filament from most viewing angles.
Collisions Between Dark Matter Confined High Velocity Clouds and Magnetized Galactic Disks: The Smith Cloud. II.
Authors: Shelton R. L. , Goetz E. H. , Galyardt J. E.
Published: October 2024

We present high-resolution simulations of high velocity clouds (HVCs) colliding with the outer part of the Galactic disk. All of the simulations include a 3 × 108
M
⊙ dark matter subhalo. Three simulations model a dark matter subhalo without a gaseous component, while eight simulations model a dark matter subhalo accompanied by a gaseous cloud of mass 2–8 × 106
M
⊙. Half of the simulations include the coherent component of the Galaxy's magnetic field. Each simulation spans ∼40 million years before the collision and ∼40 million years after the collision. The collisions between the gas cloud and disk splash gas into the halo, punch half-kiloparsec-size holes in the disk, and form long-lived, multi-kiloparsec-size shells. Each shell encloses a bubble of relatively cool gas. Holes and shells of these scales would be observable, and some have been observed in the past. We determine the fate of the HVC gas, temperature, composition, and ionization state of the bubble and shell gas, size and longevity of the holes, and effects of cloud density. Simulations show that the clouds do not survive the chaos of passage through the disk, but instead become part of the splash, bubble, and shell. Some dark matter clouds may appear to carry material with them long after the collision, but this material is shell gas that was captured by the dark matter subhalo. These results have ramifications for the Smith Cloud and other clouds hypothesized to have hit the Galactic disk.
Topological Approach to Void Finding Applied to the SDSS Galaxy Map
Authors: Aggarwal Manu , Tonegawa Motonari , Appleby Stephen , Park Changbom , Periwal Vipul
Published: October 2024

The structure of the low redshift Universe is dominated by a multiscale void distribution delineated by filaments and walls of galaxies. The characteristics of voids, such as morphology, average density profile, and correlation function, can be used as cosmological probes. However, their physical properties are difficult to infer due to shot noise and the general lack of tracer particles used to define them. In this work, we construct a robust, topology-based void-finding algorithm that utilizes Persistent Homology to detect persistent features in the data. We apply this approach to a volume-limited subsample of galaxies in the SDSS I/II Main Galaxy catalog with the r-band absolute magnitude brighter than M

r
= −20.19, and a set of mock catalogs constructed using the Horizon Run 4 cosmological N-body simulation. We measure the size distribution of voids, their averaged radial profile, sphericity, and the centroid nearest neighbor separation, using conservative values for the threshold and persistence. We find 32 topologically robust voids in the SDSS data over the redshift range 0.02 ≤ z ≤ 0.116, with effective radii in the range 21−56 h
−1 Mpc. The median nearest neighbor void separation is found to be ∼57 h
−1 Mpc, and the median radial void profile is consistent with the expected shape from the mock data.
A Comprehensive Study of Open Cluster Chemical Homogeneity Using APOGEE and Milky Way Mapper Abundances
Authors: Sinha Amaya , Zasowski Gail , Frinchaboy Peter , Cunha Katia , Souto Diogo , Tayar Jamie , Stassun Keivan
Published: October 2024

Stars in an open cluster are assumed to have formed from a broadly homogeneous distribution of gas, implying that they should be chemically homogeneous. Quantifying the level to which open clusters are chemically homogeneous can therefore tell us about interstellar medium pollution and gas mixing in progenitor molecular clouds. Using Sloan Digital Sky Survey (SDSS)-V Milky Way Mapper and SDSS-IV Apache Point Observatory Galaxy Evolution Experiment DR17 abundances, we test this assumption by quantifying intrinsic chemical scatter in up to 20 different chemical abundances across 26 Milky Way open clusters. We find that we can place 3σ upper limits on open cluster homogeneity within 0.02 dex or less in the majority of elements, while for neutron capture elements, as well as those elements having weak lines, we place limits on their homogeneity within 0.2 dex. Finally, we find that giant stars in open clusters are ∼0.01 dex more homogeneous than a matched sample of field stars.
New species, new geographical records and taxonomical notes on North and Central American Cerambycidae and Disteniidae (Coleoptera, Chrysomeloidea)
Authors: Santos-Silva Antonio , Botero Juan Pablo , Pérez-Flores Oscar
Published: October 2024

Elytrimitatrix (Grossifemora) pubescens Santos-Silva & Hovore, 2008 (Disteniidae) is redescribed based on three males, morphological and chromatic variation in the species is reported. The unknown female of Neocompsa flavoquadripunctata Botero & Santos-Silva, 2022 is shortly described and a new Mexican state record is provided. The absence of the paratype of Nealcidion bruchi (Melzer, 1934) in the MZSP collection (see acronym below) is reported, and the date of description of the species is commented. Alphinellus Bates, 1881 is transferred from Acanthocinini to Desmiphorini. Alphinellus minimus Bates, 1881 is recorded for the first time from the Mexican state of Campeche and from Guatemala. Three new species are described: Psyrassa peninsularissp. nov. (Cerambycidae, Cerambycinae, Elaphidiini) from Mexico (Quintana Roo); Pseudastylopsis skillmanisp. nov. (Cerambycidae, Lamiinae, Acanthocinini), from Guatemala; and Eranina amaurasp. nov. (Cerambycidae, Lamiinae, Hemilophini), from Guatemala.
The genus Colydium Fabricius in Europe (Coleoptera, Zopheridae, Colydiinae) with description of a new species, Colydium noblecourti sp. nov.
Authors: Parmain Guilhem , Eckelt Andreas , Schuh Rudolf
Published: October 2024

A new species of the genus Colydium Fabricius, 1792 (Coleoptera, Zopheridae, Colydiinae), Colydium noblecourtisp. nov. is described. An illustrated and updated key for the identification of the Western Palearctic species of Colydium is presented. Distribution maps for the three species are provided.
Managing Stress From a Systemic Perspective: Occupational Stress Models
Authors: Banu Sophia , Shamim Afroz , Sanchez Roberto D. , Memon Raheel Imtiaz , Moukaddam Nidal
Published: October 2024

The World Health Organization (WHO) defines stress as a “state of worry or mental tension caused by a difficult situation.” Burnout results from chronic occupational stress that has not been well managed, and is the result of both systemic and personal factors. Systemic structures and planning to optimize work environments are the focus of occupational stress models. To effectively manage stress and avoid the detrimental effects of neglecting both its acute and chronic consequences (such as decreased productivity, low morale, interpersonal conflicts, absenteeism, and other negative outcomes), it is essential to examine various occupational stress models to determine root causes and identify issues at the work unit level.[Psychiatr Ann. 2024;54(10):e287–e291.]
Assessing the Responses of Large Language Models (ChatGPT-4, Claude 3, Gemini, and Microsoft Copilot) to Frequently Asked Questions in Retinopathy of Prematurity: A Study on Readability and Appropriateness
Authors: Ermis Serhat , Özal Ece , Karapapak Murat , Kumantaş Ebrar , Özal Sadık Altan
Published: October 2024

Purpose

To assess the appropriateness and readability of responses provided by four large language models (LLMs) (ChatGPT-4, Claude 3, Gemini, and Microsoft Co-pilot) to parents' queries pertaining to retinopathy of prematurity (ROP).

Methods

A total of 60 frequently asked questions were collated and categorized into six distinct sections. The responses generated by the LLMs were evaluated by three experienced ROP specialists to determine their appropriateness and comprehensiveness. Additionally, the readability of the responses was assessed using a range of metrics, including the Flesch-Kincaid Grade Level (FKGL), Gunning Fog (GF) Index, Coleman-Liau (CL) Index, Simple Measure of Gobbledygook (SMOG) Index, and Flesch Reading Ease (FRE) score.

Results

ChatGPT-4 demonstrated the highest level of appropriateness (100%) and performed exceptionally well in the Likert analysis, scoring 5 points on 96% of questions. The CL Index and FRE scores identified Gemini as the most readable LLM, whereas the GF Index and SMOG Index rated Microsoft Copilot as the most readable. Nevertheless, ChatGPT-4 exhibited the most intricate text structure, with scores of 18.56 on the GF Index, 18.56 on the CL Index, 17.2 on the SMOG Index, and 9.45 on the FRE score. This suggests that the responses demand a college-level comprehension.

Conclusions

ChatGPT-4 demonstrated higher performance than other LLMs in responding to questions related to ROP; however, its texts were more complex. In terms of readability, Gemini and Microsoft Copilot were found to be more successful.

[
J Pediatr Ophthalmol Strabismus
. 20XX;XX(X):XXX–XXX.]
On univalent spirallike log-harmonic mappings
Authors: Wang Chuang , Mo Junzhe , Liu Zhihong
Published: October 2024

This study investigates univalent log-harmonic mappings, a class of functions that map the unit disk into the complex plane. First, we establish the necessary and sufficient conditions for univalent log-harmonic mappings to map the unit disk onto a spirallike region. We then explore the relationship between starlike harmonic mappings and spirallike log-harmonic mappings, providing several examples to illustrate our results. Finally, under specific conditions, we present growth and covering theorems for univalent log-harmonic mappings and determine the radius of spirallikeness for starlike log-harmonic mappings.
XOR count and block circulant MDS matrices over finite commutative rings
Authors: Ali Shakir , Alali Amal S. , Khan Atif Ahmad , Wijayanti Indah Emilia , Wong Kok Bin
Published: October 2024

Block circulant MDS matrices are used in the design of linear diffusion layers for lightweight cryptographic applications. Most of the work on construction of block circulant MDS matrices focused either on finite fields or $ GL(m, \mathbb{F}_2) $. The main objective of this paper is to extend the above study of block circulant MDS matrices to finite commutative rings. Additionally, we examine the behavior of the XOR count distribution under different reducible polynomials of equal degree over $ \mathbb{F}_2 $. We show that the determinant of a block circulant matrix over a ring can be expressed in a simple form. We construct $ 4 \times 4 $ and $ 8 \times 8 $ block circulant matrices over a ring. Furthermore, for non-negative integer $ l $, we identify the conditions under which a ring $ \mathfrak{R}_l = \frac{\mathbb{F}_2[x]}{\langle (f(x))^{2^l} \rangle} $, contains a finite field of order $ 2^m $, where $ f(x) $ is an irreducible polynomial of degree $ m $. To facilitate efficient implementation, we analyze XOR distributions within specific rings, such as $ R_1 = \frac{\mathbb{F}_2[x]}{\langle (1+x^2+x^6) \rangle} $ and $ R_2 = \frac{\mathbb{F}_2[x]}{\langle (1+x^4+x^6) \rangle} $. Our calculations reveal distinct XOR distributions when utilizing two reducible polynomials of equal degree, with XOR count distributions 776 and 764, respectively. However, when using irreducible polynomials of the same degree, the XOR count distributions remain the same. This difference is advantageous for applications in lightweight cryptography.
Weak Hardy spaces associated with para-accretive functions and their applications
Authors: Wang Yan , Dong Xintian , Liao Fanghui
Published: October 2024

In this paper, we introduced a new class of weak Hardy spaces, denoted by $ H^{p, \infty}_b $, and provided an analysis of their atomic decomposition. As an application, we established the boundedness of Calderón-Zygmund operators (CZOs) from $ H^p $ to $ H^{p, \infty}_b $ including cases at the critical exponent

   \begin{document}$ p = \frac{n}{n+\delta}, $\end{document}

where $ \delta $ represents the regularity index of the distributional kernel. Moreover, the boundedness of CZOs from $ H^{p, \infty} $ to $ H^{p, \infty}_b $ was demonstrated for

   \begin{document}$ \frac{n}{n+\delta}
Interval edge colorings of the generalized lexicographic product of some graphs
Authors: Jin Meiqin , Chen Ping , Tian Shuangliang
Published: October 2024

An edge-coloring of a graph $ G $ with colors $ 1, \ldots, t $ is an interval $ t $-coloring if all colors are used and the colors of edges incident to each vertex of $ G $ are distinct and form an interval of integers. A graph $ G $ is interval colorable if it has an interval $ t $-coloring for some positive integer $ t $. For an interval colorable graph $ G $, the least and the greatest values of $ t $ for which $ G $ has an interval $ t $-coloring are denoted by $ w(G) $ and $ W(G) $. Let $ G $ be a graph with vertex set $ V(G) = \{u_1, \ldots, u_{m}\} $, $ m\geq2 $, and let $ h_m = (H_i)_{i\in\{1, \ldots, m\}} $ be a sequence of vertex-disjoint with $ V(H_i) = \{x_1^{(i)}, \ldots, x_{n_i}^{(i)}\} $, $ n_i\geq 1 $. The generalized lexicographic products $ G[h_m] $ of $ G $ and $ h_m $ is a simple graph with vertex set $ \cup_{i = 1}^{m}V(H_i) $, in which $ x_p^{(i)} $ is adjacent to $ x_q^{(j)} $ if and only if either $ u_i = u_j $ and $ x_p^{(i)}x_q^{(i)}\in E(H_i) $ or $ u_iu_j\in E(G) $. In this paper, we obtain several sufficient conditions for the generalized lexicographic product $ G[h_m] $ to have interval colorings. We also present some sharp bounds on $ w(G[h_m]) $ and $ W(G[h_m]) $ of $ G[h_m] $.
Asymptotic behavior of the wave equation solution with nonlinear boundary damping and source term of variable exponent-type
Authors: Al-Mahdi Adel M. , Al-Gharabli Mohammad M. , Kafini Mohammad
Published: October 2024

In this study, a nonlinear damped wave equation within a bounded domain was considered. We began by demonstrating the global existence of solutions through the application of the well-depth method. Following this, a general decay rate for the solutions was established using the multiplier method alongside key properties of convex functions. Notably, these results were derived without the imposition of restrictive growth assumptions on the frictional damping, making this work an improvement and extension of previous findings in the field.
Identifiability investigation of within-host models of acute virus infection
Authors: Liyanage Yuganthi R. , Heitzman-Breen Nora , Tuncer Necibe , Ciupe Stanca M.
Published: October 2024

Uncertainty in parameter estimates from fitting within-host models to empirical data limits the model's ability to uncover mechanisms of infection, disease progression, and to guide pharmaceutical interventions. Understanding the effect of model structure and data availability on model predictions is important for informing model development and experimental design. To address sources of uncertainty in parameter estimation, we used four mathematical models of influenza A infection with increased degrees of biological realism. We tested the ability of each model to reveal its parameters in the presence of unlimited data by performing structural identifiability analyses. We then refined the results by predicting practical identifiability of parameters under daily influenza A virus titers alone or together with daily adaptive immune cell data. Using these approaches, we presented insight into the sources of uncertainty in parameter estimation and provided guidelines for the types of model assumptions, optimal experimental design, and biological information needed for improved predictions.
An epidemiological modeling investigation of the long-term changing dynamics of the plague epidemics in Hong Kong
Authors: Musa Salihu S. , Zhao Shi , Mkandawire Winnie , Colubri Andrés , He Daihai
Published: October 2024

Identifying epidemic-driving factors through epidemiological modeling is a crucial public health strategy that has substantial policy implications for control and prevention initiatives. In this study, we employ dynamic modeling to investigate the transmission dynamics of pneumonic plague epidemics in Hong Kong from 1902 to 1904. Through the integration of human, flea, and rodent populations, we analyze the long-term changing trends and identify the epidemic-driving factors that influence pneumonic plague outbreaks. We examine the dynamics of the model and derive epidemic metrics, such as reproduction numbers, that are used to assess the effectiveness of intervention. By fitting our model to historical pneumonic plague data, we accurately capture the incidence curves observed during the epidemic periods, which reveals some crucial insights into the dynamics of pneumonic plague transmission by identifying the epidemic driving factors and quantities such as the lifespan of flea vectors, the rate of rodent spread, as well as demographic parameters. We emphasize that effective control measures must be prioritized for the elimination of fleas and rodent vectors to mitigate future plague outbreaks. These findings underscore the significance of proactive intervention strategies in managing infectious diseases and informing public health policies.
Arrogancia, desconfianza y desafección. Una aproximación desde la epistemología de la virtud
Authors: Velasco Arias Gonzalo
Published: October 2024

La desafección política puede vincularse con la comprobada desconfianza en las instituciones de intermediación más relevantes en las democracias representativas: partidos políticos y medios de comunicación. La relativa cronificación de esta desconfianza se explica por una generalización de disposiciones subjetivas de arrogancia epistémica y de confianza ilusoria, que suponen o bien una renuncia o bien un mal uso de los criterios para evaluar la confidencialidad de las mediaciones. Para diagnosticar las situaciones y valorar posibilidades de respuesta, se propone un análisis fundamentado en el marco teórico de la epistemología de la virtud y de la epistemología social basada en sistemas. Contra las narrativas nostálgicas excepcionalistas sobre la sociedad digitalizada, se apuntará como línea de indagación constructiva al estudio de formas de reelaboración de la confianza que asuman de forma realista la fragmentación del espacio público digitalizado.
Navigating Central-Local Dynamics
Authors: Ho Wing-chung
Published: October 2024

This paper examines the central-local relation between Beijing and Hong Kong in the final stage of the COVID-19 combat, by analyzing Hong Kong's policy responses regarding public space governance in 2022. Drawing on the combined theoretical insights of governance diffusion and political steering, this study investigates how Hong Kong governed its public spaces during the dramatic shifting pandemic measures – from China's initial “zero-tolerance” policy at the start of 2022, to the complete embrace of the global “co-existence” norm towards the end of the year. Through the analysis of publicly available data, the findings not only offer nuanced insights into the complex central-local dynamics in governance during the pandemic, but also highlight the broader implications of the rise of authoritarian statehood in potentially threatening the sustainability of Hong Kong's neoliberal governance system in the future.
3D-Printed Flexible Polyacrylamide/Alginate Gel Polymer Electrolyte for Zinc-Ion Batteries
Authors: Wongduangpa Napassorn , Poompiew Nutthapong , Aumnate Chuanchom , Potiyaraj Pranut
Published: October 2024

Flexible and wearable electronics are increasingly popular and utilized in various forms. Batteries have become essential as an energy source for wearable electronics. To meet demands of such electronics, these batteries must remain flexible, lightweight, possess good electrochemical performance, customizable shape, and ensure safety. Zinc-ion batteries (ZIBs) have emerged as a promising energy source for these applications. However, ZIBs encounter challenges due to the lack of flexible electrolytes. Polyacrylamide (PAM) is a polymer widely used as gel polymer electrolytes (GPEs) owing to its versatile electrical conductivity and excellent flexibility. However, PAM alone lacks the mechanical strength required to support flexible and wearable electronics adequately. To address this limitation, alginate (Alg), a polysaccharide with good compatibility with PAM, is incorporated in varying concentrations (0-3 %wt.) to form interpenetrating networks (IPN) hydrogels, with a chemical network of PAM and a physical network of alginate to enhance the overall mechanical properties. Following this, the 3D-printed PAM/Alg hydrogels are immerged in a 2M ZnSO4 electrolyte to create PAM/Alg gel polymer electrolytes (PAM/Alg-GPEs). This process significantly improves the mechanical properties of PAM/Alg-GPEs. Subsequently, the ionic conductivity of these 3D-printed PAM/Alg-GPEs is evaluated using electrochemical impedance spectroscopy (EIS). The results demonstrate that PAM/Alg-GPEs exhibit the desired flexibility along with sufficient electrochemical performance, making them promising candidates for use as wearable electrolytes in zinc-ion batteries.
Synthesis of Silver Nanoparticles with Syzygium aromaticum Leaves Extract as Antioxidant and Antimicrobial Materials
Authors: Madiabu Mohammad Jihad , Aziz Ilyas Taufik Abdul , Supriyono Supriyono , Putra Arie Pratama , Cahyotomo Anom , Panglipur Hanum Sekar
Published: October 2024

Silver nanoparticles (AgNPs) have attracted attention due to their unique properties and potential application. This research aimed to do green synthesis of AgNPs with Syzygium aromaticum leaves extract (SALE) and evaluate their antibacterial and antioxidant activities. Syzygium aromaticum leaves were extracted using distilled water at 70 °C for 30 min and the results were characterized with FTIR. AgNPs were synthesized by mixing AgNO3 precursor with SALE. The effects of parameters such as volume ratio of AgNO3 precursor to SALE, AgNO3 concentrations, and synthesis times were investigated. The synthesized AgNPs were characterized using UV-Vis spectrophotometer, FTIR, and TEM. Antibacterial activity of SALE and AgNPs was investigated against Escherichia coli (E.coli) and Bacillus subtilis (B. subtilis) with disc diffusion method and antioxidant activity was tested with DPPH method. The FTIR characterization revealed that SALE and resulting AgNPs contain O-H, C-H, C=O, C=C, C-O, and C≡C functional groups. The UV-Vis characterization demonstrated that AgNPs exhibited an absorption peak at λ = 420 nm indicating surface plasmon resonance. The optimal volume ratio of AgNO3 to SALE, AgNO3 concentrations, and synthesis time for AgNPs synthesis was achieved at 10:3, 5 mM, and 60 min respectively. TEM characterization indicated that AgNPs have spherical form and sizes ranging from 14 to 32 nm. The antibacterial testing revealed that AgNPs have antibacterial activities against E. coli and B. subtilis with inhibition zone values are 8,38 ± 0,48 and 6,88 ± 1,47 respectively. Additionally, antioxidant testing presented that the IC50 values were 85.05 µg/mL for SALE and 34.71 µg/mL for AgNPs. The results indicate that green synthesis of AgNPs from AgNO3 precursor with SALE was done successfully and this nanoparticle has good antibacterial and antioxidant activities.
Comparative Study of Raw and Water Rinsed Loa Janan’s Bituminous Coal Structure
Authors: Mutrofin Siti , Retnowati Rurini , Tjahjanto Rachmat Triandi , Kendek Johan , Noor Aswad Muhammad
Published: October 2024

East Kalimantan’s Coal has total humidity level at 18.21%, inherent humidity of 12.39%, fly ash content of 5.18%, volatile compounds of 38.22% and heat content of 6084 kcal/kg. However, chemical composition, functional group and crystallinity of raw and water rinsed Loa Janan bituminous coal have not been reported elsewhere. This research aims to investigate whether water rinsed treatment affects the structure of the coal or not. Coal size at 100 mesh-200 mesh is divided into 2, labeled as bituminous (a) stands for raw bituminous and bituminous (b) is for water rinsed-one. The bituminous (a) was analyzed using scanning electron miscroscopy (SEM)-energy dispersive xray (EDX), x-ray fluorescence (XRF), fourier transform infrared (FTIR) and powder x-ray diffraction (p-XRD) spectrophotometer. Meanwhile, bituminous (b) was heated at 40°C for 10 hours, cooled, rinsed using aquademin (1:5), stirred for 3 hours at 1500 rpm, and filtered. The bituminous (b) was heated at 40°C for another 10 hours and was characterized using the same technique as conducted to bituminous (a). Images revealed by SEM-EDX confirms the morphology ang topology of bituminous coal and the carbon content of them are 70.24% ± 0.87 (coal a) and 70.73% ± 0.08 (coal b). X-ray fluorescence analysis revealed that the bituminous (a) consisted of: Fe (46%), Si (21.5%), Al (5.4%) and bituminous (b): Fe (45%), Si (18.4%), Al (4.5%). There is a significant difference of their infrared spectra, both showed the peak at 1620 cm-1 (C=C) for carbon aromatic vibration. The wide area of peak at 3423 cm-1 is responsible for OH stretching vibration. Peaks intensity at 1620 cm-1 and 3420 cm-1 of bituminous (b) increased about 43.11% and 43.34%, respectively. The crystallinity degree of bituminous (b) (47.56%) is lower than that of bituminous (a) (69.72%). A sharp peak of XRD spectrum located at 2θ of 26.6o (hkl = 002) was responsible for both quartz and graphite.
A Novel Synthesis Route of Phenyl Quinoline from Nitrochalcone with Hydrazine Hydrate in the Presence of Pd/C
Authors: Hidayah Nurul , Purwono Bambang , Kumalasari Ika Dyah
Published: October 2024

Quinoline is widely known to have many biological activities. Therefore, the development of the synthesis method of a quinoline derivative framework is a priority. A phenyl quinoline derivative, 6,7-dimethoxy-2-phenylquinoline Q1, has been successfully synthesized via a novel one-pot reaction that involves reduction, cyclization, and followed by dehydration of nitrochalcone derivate, 3-(4,5-dimethoxy-2-nitrophenyl)-1-phenylprop-2-en-1-one C1. The reaction was carried out using 80 % hydrazine hydrate in the presence of 10% Pd/C as a catalyst in an ethanol medium. Target compound Q1 was afforded in a good yield of 69.18% in a relatively short reaction time of ±2 h.
Study of the Activator Effects on the Specific Surface Area of Porous Carbon and its Performance as Lithium-Sulfur Battery Cathode
Authors: Suryana Nana , Mudaim Sarifah , Nurhilal Otong , Hidayat Sahrul
Published: October 2024

A study was conducted to investigate the effect of activator types KOH, ZnCl2, and H3PO4 on the specific surface area of porous carbon and its performance as a Li-S battery. Porous carbon was synthesized from candlenut shells through a carbonization process at 700 °C using three types of activator solutions with a concentration of 0.36 M. The porous carbon activated with KOH achieved the best results, with a specific surface area of 681 m²g-1. The porous carbon candlenut shell-sulfur (PCCS-S) composite was obtained by the solid-state reaction method in a ratio of 1:2.5 w% and heat-treated at 155 °C to form the PCCS-S composite. The PCCS-S composite was then made into a slurry and coated onto Al-foil to obtain a layer of electrodes with a thickness of 200 µm. The PCCS-S cathode was then assembled into a coin battery with lithium metal as the anode and an electrolyte of 1.0 M LiTFSi solution dissolved in 1,3-dioxolane (DOL) and 1,2-dimethoxyethane (DME) (v/v, 1:1). Charge-discharge characterization was carried out at a charge rate of 1 C for 50 cycles. Characterization shows that the performance of the PCCS-S KOH composite cathode Li-S battery is stable at a specific capacity of 324 mAhg-1 after the first 10 cycles, with an average Coulombic efficiency of around 86.8 %.
A Facile Two-Step Utilization of Sorghum Waste Derived Activated Carbon
Authors: Ikhsanudin Muhammad Nur , Apriliyani Enni , Yudha Cornelius Satria
Published: October 2024

Sorghum (Sorghum bicolor (L.) Moench) is an agricultural commodity that produces waste, including stems, during its cultivation. Sorghum stems can be used as an alternative precursor for forming activated carbon (AC) with a high surface area by utilizing ZnCl2 as an activator and followed by a pyrolysis process at 750 °C under N2 gas. In this study, AC from sorghum stems was sequentially used as an adsorbent for heavy metals in wastewater, as well as applied as an anode material for lithium-ion batteries. From the characterization analysis, the synthesized AC has an amorphous structure, a high carbon content of > 90%, and a surface area of 1189 m2/g. AC was applied to adsorb 10, 50, and 100 ppm of metal cobalt (Co) at 30 °C. The adsorption isotherm and kinetics of metal Co showed an adsorption capacity of around 28.2 mg/g. The Langmuir isotherm model also describes Co adsorption and follows the pseudo-first-order equation. As for the Li-ion anode material, the ACs material is fabricated on a cylindrical battery with LiNi0.8Co0.1Mn0.1O2 as the counter cathode material. The specific discharge capacity results are 104 mAh/g at the voltage window of 2.7-4.3 V. The sequential utilization of sorghum stem-derived activated carbon can improve the product’s sustainability, and such an approach is promising to be applied in other biomass-based waste treatments.Keywords: Activated carbon, adsorption, battery, biomass, sorghum
Influence of Silicon Carbide Incorporation on Thermal and Ablation Properties of Carbon Fabric-Phenolic Resin Composites
Authors: Praveen Kumar Basingala , Naidu N.V. Swamy
Published: October 2024

To shield re-entry spacecraft from the extreme heat experienced during hypersonic flight through a planet's or the earth's atmosphere, thermal protection systems (TPS) were developed. This work involved the fabrication of composites using a polyacrylonitrile (PAN) based carbon fabric (Cf)-phenolic resin matrix (PR) modified with different weight percentages (wt.%) of silicon carbide (SiC), namely 0 wt.% (Cf/PR), 1wt.%, 3wt.%, and 5wt.%. The composites were prepared using the hydraulic hot press method. The manufactured composites were analyzed for their thermal conductivity and resistance to ablation using an oxyacetylene torch test. Furthermore, the ablated composites underwent X-ray diffraction (XRD), revealing a SiO2 compound layer on the ablated composite surface. The experimental results demonstrated that the Cf/PR composites modified with 3wt.% of SiC exhibited superior characteristics. The composites consist of 3wt.% Cf/PR-SiC exhibited a thermal conductivity value of 0.57 W/m K. Additionally, these composites showed a noticeable decrease in the mass ablation rate (MAR) at 0.0052 mm/sec and linear ablation rates (LAR) at 0.025061 gm/sec. This study proposed an effective way to improve the thermal and ablation characteristics of TPS materials.