bluuebunny/crossref_metadata_2025 huggingface dataset:
Toward More Accurate Synthetic Reflection Spectra: Improving the Calculations of Returning Radiation
Authors: Mirzaev Temurbek , Riaz Shafqat , Abdikamalov Askar B. , Bambi Cosimo , Dauser Thomas , Garcia Javier A. , Jiang Jiachen , Liu Honghui , Shashank Swarnim
Published: April 2024

We present a new model to calculate reflection spectra of thin accretion disks in Kerr spacetimes. Our model includes the effect of returning radiation, which is the radiation that is emitted by the disk and returns to the disk because of the strong light bending near a black hole. The major improvement with respect to the existing models is that it calculates the reflection spectrum at every point on the disk by using the actual spectrum of the incident radiation. Assuming a lamppost coronal geometry, we simulate simultaneous observations of NICER and NuSTAR of bright Galactic black holes and we fit the simulated data with the latest version of relxill (modified to read the table of reflionx, which is the nonrelativistic reflection model used in our calculations). We find that relxill with returning radiation cannot fit well the simulated data when the black hole spin parameter is very high and the coronal height and disk’s ionization parameter are low, and some parameters can be significantly overestimated or underestimated. We can find better fits and recover the correct input parameters as the value of the black hole spin parameter decreases and the value of the coronal height increases.
Identifying Plasma Fractionation Processes in the Chromosphere Using IRIS
Authors: Long David M. , Baker Deborah , To Andy S. H. , van Driel-Gesztelyi Lidia , Brooks David H. , Stangalini Marco , Murabito Mariarita , James Alexander W. , Mathioudakis Mihalis , Testa Paola
Published: April 2024

The composition of the solar corona differs from that of the photosphere, with the plasma thought to fractionate in the solar chromosphere according to the first ionization potential (FIP) of the different elements. This produces a FIP bias, wherein elements with a low FIP are preferentially enhanced in the corona compared to their photospheric abundance, but direct observations of this process remain elusive. Here, we use a series of spectroscopic observations of active region AR 12759 as it transited the solar disk over a period of 6 days from 2020 April 2–7 taken using the Hinode Extreme ultraviolet Imaging Spectrometer and Interface Region Imaging Spectrograph (IRIS) instruments to look for signatures of plasma fractionation in the solar chromosphere. Using the Si x/S x and Ca xiv/Ar xiv diagnostics, we find distinct differences between the FIP bias of the leading and following polarities of the active region. The widths of the IRIS Si iv lines exhibited clear differences between the leading and following polarity regions, indicating increased unresolved wave activity in the following polarity region compared to the leading polarity region, with the chromospheric velocities derived using the Mg ii lines exhibiting comparable, albeit much weaker, behavior. These results are consistent with plasma fractionation via resonant/nonresonant waves at different locations in the solar chromosphere following the ponderomotive force model, and indicate that IRIS could be used to further study this fundamental physical process.
Visit Nearby Halo Substructures Using LAMOST DR9 MRS Data
Authors: Tang 唐 Xin-Zhe 馨哲 , Zhao 赵 Jing-Kun 景昆 , Yang 杨 Yong 勇 , Ye 叶 Xian-Hao 先豪 , Zhao 赵 Gang 刚 , Gao 高 Qi 启
Published: April 2024

Based on the LAMOST DR9 Medium Resolution Spectra (MRS) catalog, combined with astrometries from Gaia DR3, we conducted an investigation into the substructures in the stellar halo to obtain their chemical and kinematic information. We employed the HDBSCAN algorithm in the (L

z
, E, L

xy
) space for clustering and utilized Mahalanobis distance to merge the clustering results. Ultimately, within the LAMOST DR9 MRS catalog, we identified members of Gaia–Sausage–Enceladus (GSE), Helmi streams, and the high-α disk and in situ halo. Additionally, there are three clusters that cannot be correlated with known substructures. Based on their angular momentum (L

z
) characteristics, we have tentatively named two of them High-L

z
-Cluster-1 (HLC-1) and High-L

z
-Cluster-2 (HLC-2), both exhibiting high angular momentum (L

z
) features. The third cluster, owing to its extremely low L

z
, is termed the Low-L

z
-Cluster. Then detailed analysis about those substructures are executed including member stars’ identification and kinematic and chemical distribution. The resulting GSE member stars exhibit a well-defined metallicity distribution function with its peak at [Fe/H] ∼ −1.2, consistent with previous findings, and we found there appear to be some differences in the distribution on the V
total–r
gal plane between GSE and its included Splash component. Regarding Helmi streams, in the [Mg/Fe]–[Fe/H] plane we detected potential traces of the α-knee phenomenon at [Fe/H] ∼ −1.53. Finally, we tentatively provide the possible origin for the HLC-1 and HLC-2.
Parallel Diffusion Coefficient of Energetic Charged Particles in the Inner Heliosphere from the Turbulent Magnetic Fields Measured by Parker Solar Probe
Authors: Chen Xiaohang , Giacalone Joe , Guo Fan , Klein Kristopher G.
Published: April 2024

Diffusion coefficients of energetic charged particles in turbulent magnetic fields are a fundamental aspect of diffusive transport theory but remain incompletely understood. In this work, we use quasi-linear theory to evaluate the spatial variation of the parallel diffusion coefficient κ
∥ from the measured magnetic turbulence power spectra in the inner heliosphere. We consider the magnetic field and plasma velocity measurements from Parker Solar Probe made during Orbits 5–13. The parallel diffusion coefficient is calculated as a function of radial distance from 0.062 to 0.8 au, and the particle energy from 100 keV to 1 GeV. We find that κ
∥ increases exponentially with both heliocentric distance and energy of particles. The fluctuations in κ
∥ are related to the episodes of large-scale magnetic structures in the solar wind. By fitting the results, we also provide an empirical formula of κ
∥ = (5.16 ± 1.22) × 1018
r
1.17±0.08
E
0.71±0.02 (cm2 s−1) in the inner heliosphere, which can be used as a reference in studying the transport and acceleration of solar energetic particles as well as the modulation of cosmic rays.
Suppression of Star Formation in Galaxy Pairs
Authors: Feng 冯 Shuai 帅 , Shen 沈 Shi-Yin 世银 , Yuan 袁 Fang-Ting 方婷 , Zhong 钟 Wen-Xin 文心 , Cui 崔 Wen-Yuan 文元 , Li 李 Lin-Lin 林林
Published: April 2024

We investigate the suppression of star formation in galaxy pairs based on the isolated galaxy pair sample derived from the Sloan Digital Sky Survey survey. By comparing the star formation rate between late-type galaxies (LTGs) in galaxy pairs and those in the isolated environment, we detect a signal of the suppression of star formation in galaxy pairs at d
p < 100 kpc and 200 kpc < d
p < 350 kpc. The occurrence of the suppression of star formation in these LTGs requires their companion galaxies to have an early-type morphology (n

s
> 2.5). The suppression of star formation in wide galaxy pairs at 200 kpc < d
p < 350 kpc mainly occurs in massive LTGs, while in close galaxy pairs at d
p < 100 kpc, it only appears in LTGs with a massive companion (

log

M

⋆

>
11.0

), nearly independent of their own stellar mass. Based on these findings, we infer that the suppression of star formation in wide galaxy pairs is actually a result of galaxy conformity, while in close galaxy pairs, it stems from the influence of hot circumgalactic medium surrounding companion galaxies.
Study of Magnetic Field and Turbulence in the TeV Halo around the Monogem Pulsar
Authors: Malik Sunil , Yuen Ka Ho , Yan Huirong
Published: April 2024

Magnetic fields are ubiquitous in the interstellar medium, including extended objects such as supernova remnants and diffuse halos around pulsars. Its turbulent characteristics govern the diffusion of cosmic rays and the multiwavelength emission from pulsar wind nebulae (PWNe). However, the geometry and turbulence nature of the magnetic fields in the ambient region of PWN is still unknown. Recent gamma-ray observations from HAWC and synchrotron observations suggest a highly suppressed diffusion coefficient compared to the mean interstellar value. In this study, we present the first direct observational evidence of the orientation of the mean magnetic field and turbulent characteristics by employing a recently developed statistical parameter “Y
turb” in the extended halo around the Monogem pulsar. Our study points to two possible scenarios: nearly aligned toward the line of sight (LOS) with compressible modes dominance or high inclination angle toward the LOS and characterized by Alfvénic turbulence. The first scenario appears consistent with other observational signatures. Furthermore, we report that the magnetic field has an observed correlation length of approximately 3 ± 0.6 pc in the Monogem halo. Our study highlights the pivotal role of magnetic field and turbulence in unraveling the physical processes in TeV halos and cosmic-ray transport.
Mini-RF S-band Radar Characterization of a Lunar South Pole–crossing Tycho Ray: Implications for Sampling Strategies
Authors: Rivera-Valentín Edgard G. , Fassett Caleb I. , Denevi Brett W. , Meyer Heather M. , Neish Catherine D. , Morgan Gareth A. , Cahill Joshua T. S. , Stickle Angela M. , Patterson G. Wesley
Published: April 2024

One of the youngest features on the Moon is Tycho, an 85 km diameter impact crater with a vast ray system that spans much of the lunar nearside. As such, it serves as an important stratigraphic marker for the Moon. One of Tycho’s longest rays crosses the South Pole, where it intersects several candidate landing sites for NASA’s Artemis III mission, which intends to return new lunar samples. Identification of ray-related effects are thus important to understand the provenance of collected material. To help contextualize sampling strategies, here we characterize the South Pole–crossing Tycho ray using monostatic S-band radar observations from the Lunar Reconnaissance Orbiter’s Miniature Radio Frequency instrument. We found that the ray is a ∼15 km wide radar-bright feature extending at least ∼1600 km from Tycho. Polarimetric analysis revealed that the measured radar backscatter is consistent with a terrain enhanced in centimeter-to-decimeter-scale scatterers. Moreover, we found that the abundance of these scatterers likely decreases with distance from the primary crater, suggesting there may be less Tycho-disturbed material, in particular, poleward of 85°S, where the candidate landing sites are located. Nevertheless, we identified craters along the ray and, importantly, within the Haworth candidate landing site that exhibit secondary crater characteristics, such as radar-bright, asymmetric ejecta deposits. We showed, based on solar illumination and topographic slopes, that the likely Tycho-related secondaries within Haworth are accessible by landed missions. Exploration of this site may thus directly sample Tycho-disturbed material, including a nearby permanently shadowed region, providing new insights into lunar surface processes.
Targeted Therapy of Advanced Non-Small Cell Lung Cancer
Authors: Lee Yun-Gyoo , Gil Hyun-Il , Kim Soo Jeong , Lee Hyunjoo , Nam Heerim , Ham Soo-Youn , Kang Du-Young
Published: April 2024

Lung cancer is the leading cause of cancer death in Republic of Korea. After their initial diagnosis, only 10-20% of patients with advanced non-small cell lung cancer (NSCLC) survive for 5 years of longer. Given enormous advances in therapeutics such as novel targeted therapies and immunotherapies, survival rates are improving for advanced patients with NSCLC; 5-year survival rates range from 15% to 50%, contingent upon the biomarker. Detection of the specific molecular alteration as biomarker is thus crucial for identifying subgroups of NSCLC that contain therpapeutically targetable oncogenic drivers. This review examines the process of diagnosing lung adenocarcinoma with dominant biomarkers in order to customize treatment with appropriate targeted therapy.
L’enseignement du droit économique et la transition écologique
Authors: Teller Marina
Published: April 2024

Cette contribution a pour objectif de faire un retour d’expérience sur l’enseignement du droit économique au regard de la transition écologique, après plus d’une décennie d’enseignement de cette discipline au sein de l’Université Côte d’Azur. Quelle est la place de la transition écologique au sein du droit économique ? Plus spécifiquement, ce droit permet-il une meilleure appréhension des enjeux environnementaux que ne le font les autres branches du droit ? Afin de démontrer la pertinence et l’originalité de la méthode du droit économique pour faire face aux défis de la transition écologique, il convient dans un premier temps de rappeler les postulats fondamentaux de cette école de pensée. Il en ressort que seule une méthode substantielle permet de répondre aux enjeux véritablement globaux que soulève cette transition.
La transition écologique et l’enseignement de nouvelles disciplines juridiques écologico-économiques
Authors: Couveinhes Matsumoto Florian
Published: April 2024

Le sujet de la transition écologique remet en cause les catégories disciplinaires établies. Dans le domaine du droit, c’est particulièrement le cas de la division entre droit de l’environnement et droit économique, ou entre le premier et les différentes branches du second. Du point de vue de l’enseignement, répondre à cette remise en cause impose d’élaborer des cours et manuels nouveaux, dépassant le dogme du « soutien mutuel » et faisant face au problème fondamental qui est que les règles du droit économique sont susceptibles d’empêcher le droit de l’environnement d’atteindre ses objectifs, et vice-versa.
Les cliniques juridiques : vecteurs d’innovation de l’enseignement du droit de la transition écologique
Authors: Perelman Jeremy , Bouayad Aurélien , Morin Guerry Anaïs
Published: April 2024

Inspirées en partie par les facultés de droit américaines, les cliniques juridiques se sont développées en France à partir de la fin des années 2000. Leur démultiplication au cours de la précédente décennie révèle la réussite de ce dispositif pédagogique plaçant la pratique et l’action au centre de l’apprentissage du droit. Par l’intermédiaire des projets conduits par les étudiant·es en coopération avec divers types d’acteurs, les cliniques juridiques deviennent des lieux d’expérimentation et de transformation des méthodes d’enseignement du droit. Elles accompagnent l’émergence de concepts et de catégories juridiques nouvelles visant à la concrétisation des intérêts collectifs poursuivis par ces projets. Créé en 2019, le programme « Justice environnementale et transition écologique » (JETE) de la Clinique de l’École de Droit de Sciences Po Paris illustre la richesse des liens tissés entre théorie et pratique dans le cadre de l’enseignement et de la mise en œuvre du droit de la transition écologique.
Enseignement du droit, transition écologique et liberté pédagogique
Authors: Lassalle Maxime
Published: April 2024

L’enseignement du droit va-t-il naturellement évaluer pour appréhender les questions liées à la transition écologique ? N’existe-t-il pas des contraintes structurelles qui orientent l’exercice de la liberté pédagogique des enseignants-chercheurs ? On peut estimer que les programmes de certains concours ou examens auxquels mènent les études en droit ou encore l’approche par compétences pourraient être vus à la fois comme des freins et des leviers conditionnant la place donnée aux enjeux de la transition écologique. Le rôle de ces contraintes structurelles reste toutefois encore très indéterminé.
Exact and least-squares solutions of a generalized Sylvester-transpose matrix equation over generalized quaternions
Authors: Jaiprasert Janthip , Chansangiam Pattrawut
Published: April 2024

We have considered a generalized Sylvester-transpose matrix equation $ AXB + CX^TD = E, $ where $ A, B, C, D, $ and $ E $ are given rectangular matrices over a generalized quaternion skew-field, and $ X $ is an unknown matrix. We have applied certain vectorizations and real representations to transform the matrix equation into a matrix equation over the real numbers. Thus, we have investigated a solvability condition, general exact/least-squares solutions, minimal-norm solutions, and the exact/least-squares solution closest to a given matrix. The main equation included the equation $ AXB = E $ and the Sylvester-transpose equation. Our results also covered such matrix equations over the quaternions, and quaternionic linear systems.
On CR-lightlike submanifolds in a golden semi-Riemannian manifold
Authors: Qayyoom Mohammad Aamir , Bossly Rawan , Ahmad Mobin
Published: April 2024

CR-lightlike submanifolds of a golden semi-Riemannian manifold are the focus of the research presented in this work, which aims to define and investigate these structures. Under the context of a golden semi-Riemannian manifold, we study the properties of geodesic CR-lightlike submanifolds as well as umbilical CR-lightlike submanifolds. In addition, on a golden semi-Riemannian manifold, we find numerous intriguing findings for entirely geodesic and totally umbilical CR-lightlike subamnifolds. Also, we construct an example of a CR-lightlike submanifold of a golden semi-Riemannian manifold.
Tracking control for a class of fractional order uncertain systems with time-delay based on composite nonlinear feedback control
Authors: Xing Guijun , Chen Huatao , Aghayan Zahra S. , Jiang Jingfei , Guirao Juan L. G.
Published: April 2024

In this paper, we dealt with the tracking control problem of a class of fractional-order uncertain systems with time delays. In order to handle the effects brought by the uncertainties, external disturbances, time-delay terms, and to overcome the obstacles caused by inputs saturation, the tracking controller, which consisted of linear control law, nonlinear law, and robust control law proposed in this paper, was designed by combining the composite nonlinear feedback control method and the properties of fractional order operators. Furthermore, the validation of this tracking controller was proved.
Extended existence results of solutions for FDEs of order $ 1 < \gamma\leq 2 $
Authors: Aljurbua Saleh Fahad
Published: April 2024

The focus of our investigation was on determining the existence of solutions for fractional differential equations (FDEs) of order $ 1 < \gamma\leq 2 $ involving the boundary conditions $ \kappa_{0}\phi(0)+\eta_{0}\phi(v) = \mu_{0} $, and $ \kappa_{1}\phi^{'}(0)+\eta_{1}\phi^{'}(v) = \mu_{1} $, for $ \kappa_i, \eta_i, \mu_i \in \mathbb{R}^{+} $. The existence results were based on the Schauder fixed point theorem and the nonlinear alternative of the Leray-Schauder type. Examples were provided to illustrate the results.
Unveiling the dynamics of drug transmission: A fractal-fractional approach integrating criminal law perspectives
Authors: Anjam Yasir Nadeem , Arshad Asma , Alqahtani Rubayyi T. , Arshad Muhammad
Published: April 2024

The excessive use of drugs has become a growing concern in the current century, with the global toll of drug-related deaths and disabilities posing a significant public health challenge in both developed and developing countries. In pursuit of continuous improvement in existing strategies, this article presented a nonlinear deterministic mathematical model that encapsulates the dynamics of drug addiction transmission while considering the legal implications imposed by criminal law within a population. The proposed model incorporated the fractal-fractional order derivative using the Atangana-Baleanu-Caputo ($ \mathbb{ABC} $) operator. The objectives of this research were achieved by examining the dynamics of the drug transmission model, which stratifies the population into six compartments: The susceptible class to drug addicts, the number of individuals receiving drug misuse education, the count of mild drug addicts, the population of heavy-level drug addicts, individuals subjected to criminal law, and those who have ceased drug use. The qualitative analysis of the devised model established the existence and uniqueness of solutions within the framework of fixed-point theory. Furthermore, Ulam-Hyer's stability was established through nonlinear functional analysis. To obtain numerical solutions, the fractional Adam-Bashforth iterative scheme was employed, and the results were validated through simulations conducted using MATLAB. Additionally, numerical results were plotted for various fractional orders and fractal dimensions, with comparisons made against integer orders. The findings underscored the necessity of controlling the effective transmission rate to halt drug transmission effectively. The newly proposed strategy demonstrated a competitive advantage, providing a more nuanced understanding of the complex dynamics outlined in the model.
Some positive results for exponential-kernel difference operators of Riemann-Liouville type
Authors: Mohammed Pshtiwan Othman
Published: April 2024

We established positivity of $ \nabla{f} $ obtained from a systematic computation of a composition of sequential fractional differences of the function $ {f} $ that satisfy certain conditions in a negative lower bound setup. First, we considered the different order sequential fractional differences in which we need a complicated condition. Next, we equalled the order of fractional differences and we saw that a simpler condition will be needed. We illustrated our positivity results for an increasing function of the rising type.
Des grands travaux à l’âge du Bronze... L’enceinte de la Tourelle à Lamballe
Authors: Blanchet Stéphane
Published: April 2024

De grandes enceintes doublées d’un rempart comme celle de la Tourelle à Lamballe ou de Bellevue à Lannion (toutes deux en Côte-d'Armor) ont été récemment découvertes dans le cadre de l’archéologie préventive. D’autres ouvrages fossoyés comme ceux du Val Aubin à Lamballe, de Beg ar Menez Traon à Quimper (Finistère) ou de La Rochette à Mauron (Morbihan) ont été repérés lors de prospections aériennes. Toutes ces structures remarquables tranchent nettement, par leurs dimensions et l’importance des moyens mis en œuvre pour les réaliser, avec les habitats légers et dispersés qui sont généralement mis au jour. À l’instar des imposants tumuli édifiés dans la péninsule armoricaine, ces « grands travaux » posent de nombreuses questions en termes de hiérarchisation de l’occupation et, plus largement, en termes d’organisation sociale.
Ingénierie et grands travaux. Les fondations du cirque d’Arles
Authors: Sintès Claude
Published: April 2024

Le cirque romain d’Arles, dont la construction a démarré dans les années 148-149, a mobilisé des moyens considérables pour son édification : c’est, avec l’amphithéâtre et le forum, l’un des plus importants « grand travaux » entrepris dans cette ville. Le bâtiment, installé dans une terre à portance faible le long du Rhône, a nécessité la mise en œuvre de fondations puissantes, reposant sur un pilotis de bois de grande ampleur. Cet article expose les techniques utilisées par les ingénieurs romains et l’organisation très coordonnée que cela a supposé entre les divers corps de métier impliqués : bucherons, transporteurs, sapeurs puis maçons.
Aménagement d’un site de fond de vallée. Le site de Vesvre à Neuvy-Deux-Clochers
Authors: Mataouchek Victorine
Published: April 2024

Les fouilles entreprises dans le sous-sol de la tour de Vesvre à Neuvy-deux-clochers, dans le Cher, ont donné l'opportunité d'étudier les phases de construction d'une plate-forme seigneuriale du début du Xe siècle, implantée dans un fond de vallée humide. Après le défrichement de la zone, la plate-forme a été constituée par une alternance de couches de débris végétaux et de couches d'argile, l'ensemble étant maintenu par différents types d'armatures internes, en bois ou en pierre. Les couches de végétaux contenaient de nombreux déchets d'activités artisanales qui ont donné la possibilité de mieux comprendre la vie autour du chantier. De même, l'étude carpologique et xylologique des débris végétaux a permis de restituer l'environnement naturel du site et la manière dont il a été exploité.
Les puits du second âge du Fer à Toulouse. Dix ans de recherches préventives : problématiques, méthodes, résultats et perspectives
Authors: Requi Christophe
Published: April 2024

Les fouilles préventives menées dans le quartier Saint-Roch/Saint-Agne de Toulouse ont permis de reconsidérer le dossier des puits toulousains du second âge du fer. Les dépôts identifiés en leur sein avaient longtemps caractérisé la fonction de ces puits : funéraire ou cultuelle. Grâce à une méthodologie adaptée et à la pérennité des équipes de recherches, nous avons reconstitué le cycle d’utilisation de ces structures : de leur conception à leur découverte par l’archéologue. Ces résultats associés aux études géomorphologiques du secteur permettent d’envisager sérieusement une fonction en relation avec la gestion de l’eau. Des dépôts sont parfois identifiés au sein de ces puits à eau, en général juste avant la phase d’abandon, mais ils ne caractérisent plus la fonction primaire du puits. Cette évolution de l'interprétation conduit donc à considérer ces derniers comme des indices d’habitat au sens large et à les intégrer désormais à la sphère de la vie quotidienne.
La lutte contre les discriminations : chronique de l’activité du Défenseur des droits en 2023
Authors: Durand Jeanne , Mokhnachi Cassandre
Published: April 2024

Au cours de l’année 2023, le Défenseur des droits (DDD) a une fois encore été saisi à de multiples reprises en matière de discrimination. Pour l’examen des situations, l’autorité indépendante réalise une analyse approfondie, ce qui lui permet de caractériser des discriminations, même lorsqu’elles ne sont pas visibles de prime abord. Par ailleurs, les observations que le DDD peut présenter au juge - que celui-ci l’ait ou non sollicité - sont un éclairage utile. Néanmoins, l’analyse comparative entre les décisions du Défenseur et les décisions rendues par les juridictions conduisent à relativiser l’influence de l’Institution.
Synthesis and Characterization of Enhanced Proton-Conducting Nafion® 117- Silica Composite Membranes for Fuel Cell Applications
Authors: Segale Mayetu E. , Mokrani Touhami , Sigwadi Rudzani A.
Published: April 2024

Nafion®/silica nanocomposite membranes were prepared by impregnation method from Nafion® 117 and sol-gel pre-synthesized n-octadecyl-trimethoxy silane (C18TMS) coated silica nanoparticles. The scanning electron microscope (SEM) of pristine silica particles displayed monodispersed nanospheres with diameters ranging from 150-350 nm; while Brunauer-Emmett-Teller (BET) analysis presented 760 m2/g BET surface area, a micropore-mesopore bimodal distribution of micropore systems with respective pore volume at 14.6 Å and 17.0 Å (2.01 x 10-3 cm3/g.Å), as well as the prolific mesopores centered at 29.5 Å (5.64 x 10-2 cm3/g.Å). Characterization of Nafion® 117 based membranes on SEM, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and x-ray diffraction (XRD), and tensile stress exhibited varying surface morphology with silica loadings, structural interaction between membrane support and the ion exchanger, thermal stabilities (up to 330 °C), crystalline nature, and reasonable mechanical stability of nanocomposite membranes. The maximum water uptake (44.8 %) and proton conductivity of (1.14 x10-2 S/cm) were obtained on low Nafion®/SiO2 (5%) loaded membrane. While both composite membranes displayed the improved reduction in methanol permeability, 2.43x10-07 cm2/s at 80 °C was obtained with high Nafion®/SiO2 (10%) loading. Improved water uptake and proton conductivity substantiate the high ion exchange capacity (IEC) of 1.81 meq.g-1 when compared to IEC of 0.93 meq.g-1 [pristine Nafion®] and 1.46 meq.g-1 [Nafion®/SiO2 (10%)]. The increase in IEC value may be due to the high acid functionalization of additional sulfonic acid groups surrounded by hydrophilic segments of nanosilica, which improves the properties of the membrane. The high proton conductivity coupled with great water retention capabilities indicated that the Nafion®/SiO2 nanocomposite membranes could be utilized as proton exchange membranes for medium temperature methanol fuel cells. Keywords: Fuel cells; nanocomposite membrane; SiO2 nanofillers; methanol permeability; ion exchange capacity
Temperature Etching and Metallic Agent Concentration Effect on Structure, Morphology and Wettability of Silicon Nanowires
Authors: Lamrani S. , Hadjersi T. , Amirouche S. , Oussaf N. , Mebarki M. , Belhoucif R.
Published: April 2024

Abstract. Structural, Morphologycal and Wettability of SiliconNanowires (SiNWs) elaborated using Ag assisted electroless chemical etching are investigated. Prior the etching, Ag nanoparticles (AgNPs) were deposited at room temperature in a HF/AgNO3 solution with different concentration of AgNO3. The XRD spectra of the Ag NPs deposit show a good crystallinity. The effects of temperature etching bath and concentrations of AgNO3 on the etching process were examined. The morphological study, performed using a Scanning Electron Microscopy (SEM), shows porous silicon layer of 2µm for the lower temperature etching. For 25°C, perpendicular silicon nanowires about 15µm were formed. For the higher etching temperature (50°C), the silicon nanowire about 50 nm in diameter and 50µm in length were formed. The impact of Ag concentration on the SiNWs formation is examined in the second part of the present work. It is shown that the etching depth decreases as the Ag concentration decreases with values of 2.8 μm and 2 μm for concentrations of 0.025M and 0.0125M, respectively. The hydrophobicity of the samples was monitored by measuring the contact angle between a drop of water and the sample surface. It was established that the morphology is strongly influenced by etching conditions and their wettability changes from superhydrophilic to hydrophobic. FTIR analysis confirms the oxide-free silicon nanowires.
Synthesis and Optical Properties of CH3NH3PbI3 Nanorods with Defects States
Authors: Najih Hassan , Labchir Nabil , Tihane Abdellah , Narjis Abdelfattah , Atourki Lahoucine , Elfanaoui Abdessalam , Ihlal Ahmed
Published: April 2024

In this work, methylammonium lead halide CH3NH3PbI3 (MAPI3) perovskite nanorods were synthesized by the sol gel-spray ultrasonic method. The XRD pattern exhibits peaks assigned to the tetragonal MAPI3 structure with a residual PbI2 phase. SEM and AFM images show the formation of nanorods like picture with rough surface. The Raman spectrum was visualized to show various vibration modes in the film. Photoluminescence data revealed one emission peak at 786 nm (1.58 eV) in the band gap band, which was confirmed by the UV-Vis spectrum. The slight difference between the found band gap energy and the ideal one is explained in terms of shallow trap states.
Agricultural Waste Valorization for Nanoparticles Synthesis and Enhancement of Vapour Compression Refrigeration System’s Performance
Authors: Ajayi Oluseyi O. , Ogbonnaya Mercy , Ogo-Ozegbe Oge , Popoola Patricia Abimbola
Published: April 2024

Waste management has been a major concern in the society and agricultural wastes can be utilized in the synthesis of nanoparticles and deployed in the vapour compression refrigeration system (VCRS) to enhance its performance. This study analysed the thermophysical properties, performance, energy consumption, pull-down time, and capacities of VCRS using bio-nanoparticles produced from orange and pineapple peels. Eco-friendly refrigerants R600a and R134a with pure polyolester (POE) as the lubricating oil for the compressor were used. The nanolubricants were dispersed in three volume fractions of 0.05%, 0.10% and 0.20% concentration in the lubricant using the two-step method. The degradation of nanolubricants were analysed by examining the thermophysical properties of the nanolubricants before and after use in the VCRS. At 0.2% volume concentration, optimum COP of 6.31 and 5.01 were obtained for pineapple and orange peels respectively for R600a. The nanolubricants of orange peels with the volume fraction of 0.2% had the best pull-down time with a temperature of-2oC. The lowest power consumption was observed for 0.1% volume concentration of pineapple nanolubricants while 0.2% volume concentration of orange nanolubricants was observed to have the least power consumption. Considering the R134a refrigerant, the volume concentration with the optimum COP was 0.1 vol% concentration for the orange bio-based nanolubricants with an increase in the COP of 36.3% when compared with pure R134a while 0.2 vol% had the best pull-down time with a temperature of-3oC. There was a 14.2% drop in the power consumption of 0.1 vol% concentration of pineapple nanolubricants when compared to the various concentrations of the bio-based nanolubricants. From this study, the optimum performance was observed at 0.20 vol% concentration for the orange and pineapple nanolubricants with a relatively less power consumption. R600a refrigerant can completely replace R134a in its use in refrigeration systems and achieve similar pull-down time and coefficient of performance when bio-nanolubricants are utilized in the systems.
Evaluation of Cleaning Soiled Deposits and Crusts from Archaeological Glass Using Laser Treatment with Ag/Au Nanoparticles
Authors: Eloriby Rania Abdel Gwad , ELsayed Ghada Omar , Mahmoud Hisham Imam
Published: April 2024

The study aims to evaluate the effect of silver and gold nanoparticles during the laser cleaning process of glass artifacts. It is the first time that nanoparticles have been used to clean antique glass, as far as the authors are aware. In the context of this study, work was done on glass samples extracted from excavations that suffer from dense layers of corrosion products, soil deposits, brittle, easy to break, and cannot bear pressure. To characterize the investigated glass shards and assess the cleaning procedure, a variety of analytical techniques, including the transmission electron microscope (TEM), digital microscope, stereomicroscope, scanning electron microscope (SEM-EDX), X-ray diffraction (XRD), and color change measurement, have been used. The XRD analysis revealed different minerals such as ferrosilite, hillebrandite, and jacobsite, in the black corrosion layer, and calcite, syngenite, and arcanite in the white crust layer. The results of the microscopic examination employed in the evaluation procedure demonstrated that using Ag NPs with laser perfectly removed the tough crust layers without scratching the surface. The cleaned surface became smooth, homogenous and more transparent. The elemental analysis results by (SEM-EDX) revealed a significant reduction in the proportion elements of the (Al, Fe, p, and Mg) in the corrosion layer and their loss in the cleaned areas. Measurement of color change indicated that laser-treated glass samples with the addition of Ag NPs gave higher (ΔE*), confirming the influential role of this method in cleaning archaeological glass. It was also observed that the effect of Ag NPs with Laser assistance decreases the required time for the cleaning process. Thus the heat generated by the laser-treated was reduced, so the laser-treated with Ag NPs is recommended for use in the archaeological glass cleaning process.
Altering β Cell Antigen Exposure to Exhausted CD8+ T Cells Prevents Autoimmune Diabetes in Mice
Authors: De George David J , Jhala Gaurang , Selck Claudia , Trivedi Prerak , Brodnicki Thomas C , Mackin Leanne , Kay Thomas W , Thomas Helen E , Krishnamurthy Balasubramanian
Published: April 2024

Chronic destruction of insulin-producing pancreatic β cells by T cells results in autoimmune diabetes. Similar to other chronic T cell–mediated pathologies, a role for T cell exhaustion has been identified in diabetes in humans and NOD mice. The development and differentiation of exhausted T cells depends on exposure to Ag. In this study, we manipulated β cell Ag presentation to target exhausted autoreactive T cells by inhibiting IFN-γ–mediated MHC class I upregulation or by ectopically expressing the β cell Ag IGRP under the MHC class II promotor in the NOD8.3 model. Islet PD-1+TIM3+CD8+ (terminally exhausted [TEX]) cells were primary producers of islet granzyme B and CD107a, suggestive of cells that have entered the exhaustion program yet maintained cytotoxic capacity. Loss of IFN-γ–mediated β cell MHC class I upregulation correlated with a significant reduction in islet TEX cells and diabetes protection in NOD8.3 mice. In NOD.TII/8.3 mice with IGRP expression induced in APCs, IGRP-reactive T cells remained exposed to high levels of IGRP in the islets and periphery. Consequently, functionally exhausted TEX cells, with reduced granzyme B expression, were significantly increased in these mice and this correlated with diabetes protection. These results indicate that intermediate Ag exposure in wild-type NOD8.3 islets allows T cells to enter the exhaustion program without becoming functionally exhausted. Moreover, Ag exposure can be manipulated to target this key cytotoxic population either by limiting the generation of cytotoxic TIM3+ cells or by driving their functional exhaustion, with both resulting in diabetes protection.
Evaluation of bond strength in customizing fiber post using translucent resins photoactivated by different light-emitting diodes
Authors: Barros Antonia Patricia O. , Costa Joatan Lucas de Sousa Gomes , de Melo Alencar Cristiane , Galvani Lucas David , Dantas Andrea Abi Rached , Kuga Milton Carlos
Published: April 2024

Aims:

The objective of the study was to evaluate two translucent resin composite systems for customizing light-polymerized fiber posts with light-emitting diode (LED) curing units regarding adhesion using conventional cement at 24 h and 6 months.

Settings and Design:

This was an experimental in vitro study.

Methods:

Forty roots were prepared and divided into four groups (n = 10): ZV-Z350 resin and LED Valo; ZR-Z350 resin and LED Radii-Cal; OV-Opallis resin and LED Valo; and OR-Opallis resin and LED Radii-Cal. The fiber post was customized and cemented with conventional resin cement and was photoactivated by two different sources.

Statistical Analysis Used:

The data were subjected to two-way ANOVA and Tukey’s post hoc tests (P = 0.05). The data regarding the pattern of adhesive failures were described in terms of the frequency of occurrence in each third of the postspace.

Results:

Both at 24 h and 6 months, bond strength among groups was similar, regardless of the analyzed postspace 3rd (P > 0.05). Adhesive failure Type 4 was the most frequent in all thirds.

Conclusions:

Customizing the fiber post with Z350 and Opallis has the same effect on bond strength and adhesive failure pattern, regardless of the LED curing units used for photopolymerization.
Morphometric analysis of the relationship between maxillary posterior teeth and maxillary sinus floor in central Indian population: A cone-beam computed tomography study
Authors: Akotiya Bhavya Rajendra , Surana Anjali , Chauhan Priya , Saha Suparna G. , Agarwal Rolly S. , Vashisht Anu
Published: April 2024

Background:

The relationship between the maxillary sinus (MS) and the root apices of posterior teeth is of significant clinical relevance as it influences the diagnosis and treatment planning when operating in the posterior areas of the maxilla. The aim of this study, therefore, is to assess this anatomic relationship and evaluate the propensity of roots of posterior maxillary teeth to be intruded into the MS space using cone-beam computed tomography (CBCT) scanning.

Materials and Methods:

One thousand CBCT scans of patients, aged 20 years or above, were analyzed in the study. The distance from the MS floor to the root apices of the posterior teeth was measured and the relationship between the MS and the posterior teeth roots were recorded, based on Kwak’s and Didilescu’s classification.

Results:

Based on Kwak’s classification, type I configuration was frequently observed in the maxillary posterior teeth, followed by type II. Based on Didilescu’s classification, the longest distance, among premolars, was observed between the palatal root of the left 1st premolar and MS, i.e., 8.2467 mm. Among molars, the longest distance was observed between mesiobuccal root of the right first molar and MS, i.e., 5.8966 mm. The shortest distance, among premolars, was observed between the buccal root of the left second premolar and MS, i.e., 3.5500 mm, and among molars, the shortest distance was between the mesiobuccal root of the left second molar and MS, i.e., 1.3556 mm.

Conclusion:

From the present study, it may be concluded that, among the central Indian population, mesiobuccal root of the second molars and buccal root of the second premolars show the closest proximity to the MS floor. Therefore, any surgical or endodontic intervention in the vicinity of these roots must be performed with utmost care.
Efficiency of a high-speed handpiece with anti-retraction adapter to minimize cross-contamination during the routine dental procedure: A clinical study
Authors: Subhiksha S. R. , Arul Buvaneshwari , Natanasabapathy Velmurugan
Published: April 2024

Background:

This study aimed to detect the efficiency of anti-retraction adapter (ARA) attached to a handpiece (HP).

Materials and Methods:

Two types of dental HP with and without the ARA were used in this study. A total of 30 sets of samples were obtained from two groups and were subjected to a real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and microbial culture for quantitative analysis of total bacterial and Legionella count.

Statistical Analysis Used:

The data obtained were tabulated using the Statistical Package for the Social Sciences (SPSS, IBM version 26.0) for statistical analysis.

Results:

The water samples were analyzed using PCR, Legionella-specific PCR, and culture-based analysis. In Groups 1 and 2, there was no significant difference between bacterial load in the water samples taken from both HP and coupling of the Dental Unit Waterline (DUWL).

Conclusions:

The reduction in bacterial load in DUWLs analyzed using quantitative RT-PCR was similar in both experimental groups. Overall, the bacterial load was lower in the group with ARA when compared to the group without ARA but not statistically significant. ARA was not effective in reducing the Legionella species load in DUWLs.
Improving Performance of the Typical User in the Indoor Cooperative NOMA Millimeter Wave Networks with Presence of Walls
Authors: Lam Sinh Cong , Tran Xuan Nam
Published: April 2024

INTRODUCTION: The beyond 5G millimeter wave cellular network system is expecting to provide the high quality of service in indoor areas. OBJECTIVES: Due to the high density of obstacles, the cooperative communication technique is employed to improve the user's desired signal power by finding more than one appropriate station to serve that user. METHODS: While the conventional system utilizes additional equipment such as Reconfigurable Intelligent Surfaces (RIS) and relays to enable the cooperative features, the paper introduces a new network paradigm that utilizes the second nearest Base Station (BS) of the typical user as the Decode and Forward (DF) relay. Thus, depends on the success of decoding the message from the user' serving BS of the second nearest BS, the typical user can work with and without assistance from the relay whose operation follows the discipline of the power-domain NOMA technique. In the case of with relay assistance, the Maximum Ratio Combining technique is utilized by the typical user to combine the desired signals. RESULTS: To examine the performance of the proposed system, the Nakagami-m and the newly developed path loss model, which considers the density of walls and their properties, are adopted to derive the coverage probability of the user with and without relay assistance. The closed-form expressions of this performance metric are derived by Gauss quadrature and Welch-Satterthwaite approximation.
Optimising Deep Neural Networks for Tumour Diagnosis Algorithms Based on Improved MRFO Algorithm
Authors: Han Binbin , Zhang Fuliang , Chang Zhenyun , Feng Fang
Published: April 2024

INTRODUCTION: Cancer has become one of the most prevalent diseases with the highest mortality rate in the world, and timely detection and early acceptance of medical therapeutic interventions are effective means of controlling the progression of cancer patients and improving their post-intervention outcomes.OBJECTIVES: To make the defects of incomplete features, low accuracy and low real-time performance of current tumour diagnosis methods.METHODS: This paper proposes a tumour diagnosis method based on the improved MRFO algorithm to improve the optimization process of DBN network parameters. Firstly, the diagnostic features are extracted by analysing the tumour diagnosis identification problem; then, the manta ray foraging optimization algorithm is improved by combining the good point set initialization strategy, the adaptive control parameter strategy and the distribution estimation strategy, and the tumour diagnostic model based on the improved manta ray foraging optimization algorithm to optimize the parameters of the depth confidence network is constructed; finally, the high accuracy and real-time performance of the proposed method are verified by the analysis of simulation experiments.RESULTS: The results show that the proposed method improves the accuracy of the diagnostic model.CONLUSION: Addresses the problem of poor accuracy and real-time availability of tumour diagnostic methods.
3D Convolutional Neural Networks for Predicting Protein Structure for Improved Drug Recommendation
Authors: Kiran Sree Pokkuluri , Devi N SSSN Usha
Published: April 2024

INTRODUCTION: Protein structure prediction is critical for recommendation personalized medicine and drug discovery. This paper introduces a robust approach using 3D Convolution Neural Networks (3D CNN’s) to improve the accuracy of the structure of protein structure thus contributing for the drug recommendation system.
OBJECTIVES: In contrast to conventional techniques, 3D CNNs are able to identify complicated folding patterns and comprehend the subtle interactions between amino acids because they are able to capture spatial dependencies inside protein structures.
METHODS: Data sets are collected from Protein Data Bank, including experimental protein structures and the drugs that interact with them, are used to train the model. With the efficient processing of three-dimensional data, the 3D CNNs exhibit enhanced capability in identifying minute structural details that are crucial for drug binding. This drug recommendation system novel method makes it easier to find potential drugs that interact well with particular protein structures.
RESULTS: The performance of the proposed classifier is compared with the existing baseline methods with various parameters accuracy, precision, recall, F1 score, mean squared error (MSE)  and area under the receiver operating characteristic curve (AUC-ROC).
CONCLUSION: Deep learning and 3D structural insights work together to create a new generation of tailored and focused therapeutic interventions by speeding up the drug development process and improving the accuracy of pharmacological recommendations.