In this paper, a high-sensitivity magnetic field sensor based on a single-mode–tapered small-core–single-mode (STSCS) optical fibre structure is investigated. The tapered small-core section of STSCS ...is surrounded by magnetic fluid (MF) containing ferromagnetic particles (FMPs) of different concentrations. The FMPs align themselves along the magnetic field, depending on the strength of the magnetic field. This alignment of FMPs changes the refractive index around the tapered small-core section, which in turn changes the output spectral response of the STSCS optical fibre structure. The change in spectral response is then calibrated for sensing the magnetic field strength. This paper also investigates the effect of both the taper waist diameter of the STSCS optical fibre structure and the concentration of MF surrounding it on the magnetic field sensitivity. The maximum sensitivity demonstrated in this paper is 0.46 nm/mT for a taper waist diameter of 10 μm surrounded by 1.22% FMPs in the MF. The magnetic sensor demonstrates reversible results, and its effects on the orientation of the magnetic field along the X–Y, X–Z and Y–Z axes are also investigated, which suggest that the sensor is capable of vector magnetic field measurement.
The ecological conservation of large rivers is impossible unless immediate attention is given to protecting their small tributaries at local levels. The natural boundaries of large river basins are ...shrinking because their tributaries and streams of different orders are disappearing at an unprecedented rate. Delineation of the fixed administrative boundaries (AB) to protect the natural boundary of small rivers and their classification into appropriate threatened categories, the present study was carried out on the 54.08 km long Banki River in the Ganga River basin. The > 70% irreversible loss in the number of streams (Nu), length of streams (Lu), and drainage density (Dd) resulted in the conversion of the 6th order Banki into the 4th order river. The extreme morphometric changes result in the Banki watershed being under the "Critically Endangered" category. The drainage density ratio (DdR) and mean stream width (M
) were used to determine the width of AB (W
). The "River Red List Categories and Criteria" are being proposed to strengthen global initiatives at the local levels to protect and conserve inland water bodies and transboundary rivers.
This paper presents the case of an adjunct university professor to illustrate the dilemma of using artificial intelligence (AI) technology to grade student papers. The hypothetical case discusses the ...benefits of using a commercial AI service to grade student papers—including discretion, convenience, pedagogical merits of consistent feedback for students, and advances made in the field that yield high-quality work—all of which are achieved quickly. Arguments against using AI to grade student papers involve cost, privacy, legality, and ethics. The paper discusses career implications for faculty members in both situations and concludes with implications for researchers within the discourse on academic integrity.
This essay critiques the emphasis on detecting artificial intelligence (AI) usage in student submissions and advocates for a shift towards the meaningful integration of AI in education. Citing data ...from Turnitin, it highlights the significant yet understated prevalence of AI in academic work. The discussion underscores the ideological, detection, and moral challenges associated with AI in education, arguing for a reconceptualization of assessment and pedagogy to accommodate AI tools ethically and effectively. It calls for collaborative efforts to redesign curricula and assessments, ensuring educators and students are equipped to navigate the evolving educational landscape. The essay concludes by emphasizing the necessity of preparing graduates for a future in which AI plays a central role in learning and professional practice. Keywords: AI usage detection, ethical AI integration, academic integrity, future of AI in education
Microalgae is a renewable bioresource with the potential to replace the conventional fossil-based industrial production of organic chemicals and pharmaceuticals. Moreover, the microalgal biomass ...contains carotenoids, vitamins, and other biomolecules that are widely used as food supplements. However, the microalgal biomass production, their composition variations, energy-intensive harvesting methods, optimized bio-refinery routes, and lack of techno-economic analysis are the major bottleneck for the life-sized commercialization of this nascent bio-industry. This review discusses the microalgae-derived key bioactive compounds and their applications in different sectors for human health. Furthermore, this review proposes advanced strategies to enhance the productivity of bioactive compounds and highlight the key challenges associated with a safety issue for use of microalgae biomass. It also provides a detailed global scenario and market demand of microalgal bioproducts. In conclusion, this review will provide the concept of microalgal biorefinery to produce bioactive compounds at industrial scale platform for their application in the nutraceutical and pharmaceutical sector considering their current and future market trends.
Display omitted
•Microalgae are bio-factory that produces high value-added compounds (HVAC) from CO2.•Bioprospecting of microalgae strain enhances biomass yield and HVAC contents.•Genetic engineering boosts the accumulation of HVAC in microalgae.•Microalgae HVAC have nutraceuticals, cosmeceutical and pharmaceutical applications.•High demands for algal HVAC help to develop and sustain the circular bioeconomy.
Highlights
Operations of metal oxide semiconductors gas sensors at room temperature under photoactivation are discussed.
Emerging two-dimensional (2D) materials-based gas sensors under light ...illumination are summarized.
The advantages and limitations of metal oxides and 2D-materials-based sensors in gas sensing at room temperature under photoactivation are highlighted.
Room-temperature gas sensors have aroused great attention in current gas sensor technology because of deemed demand of cheap, low power consumption and portable sensors for rapidly growing Internet of things applications. As an important approach, light illumination has been exploited for room-temperature operation with improving gas sensor’s attributes including sensitivity, speed and selectivity. This review provides an overview of the utilization of photoactivated nanomaterials in gas sensing field. First, recent advances in gas sensing of some exciting different nanostructures and hybrids of metal oxide semiconductors under light illumination are highlighted. Later, excellent gas sensing performance of emerging two-dimensional materials-based sensors under light illumination is discussed in details with proposed gas sensing mechanism. Originated impressive features from the interaction of photons with sensing materials are elucidated in the context of modulating sensing characteristics. Finally, the review concludes with key and constructive insights into current and future perspectives in the light-activated nanomaterials for optoelectronic gas sensor applications.
The Event Horizon Telescope, a global submillimeter wavelength very long baseline interferometry array, produced the first image of supermassive black hole M87* showing a ring of diameter θd = 42 3 ...as, inferred a black hole mass of M = (6.5 0.7) × 109M , and allowed us to investigate the nature of strong-field gravity. The observed image is consistent with the shadow of a Kerr black hole, which according to the Kerr hypothesis describes the background spacetimes of all astrophysical black holes. The hypothesis, a strong-field prediction of general relativity, may be violated in the modified theories of gravity that admit non-Kerr black holes. Here, we use the black hole shadow to investigate the constraints when rotating regular black holes (non-Kerr) can be considered as astrophysical black hole candidates, paying attention to three leading regular black hole models with additional parameters g related to nonlinear electrodynamics charge. Our interesting results based on the systematic bias analysis are that rotating regular black holes shadows may or may not capture Kerr black hole shadows, depending on the values of the parameter g. Indeed, the shadows of Bardeen black holes (g 0.26M), Hayward black holes (g 0.65M) and non-singular black holes (g 0.25M) are indistinguishable from Kerr black hole shadows within the current observational uncertainties, and thereby they can be strong viable candidates for the astrophysical black holes. Whereas Bardeen black holes (g ≤ 0.30182M), Hayward black holes (g ≤ 0.73627M), and non-singular black holes (g ≤ 0.30461M), within the 1 region for θd = 39 as, are consistent with the observed angular diameter of M87*.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of COVID-19, so understanding its biology and infection mechanisms is critical to facing this major medical ...challenge. SARS-CoV-2 is known to use its spike glycoprotein to interact with the cell surface as a first step in the infection process. As for other coronaviruses, it is likely that SARS-CoV-2 next undergoes endocytosis, but whether or not this is required for infectivity and the precise endocytic mechanism used are unknown. Using purified spike glycoprotein and lentivirus pseudotyped with spike glycoprotein, a common model of SARS-CoV-2 infectivity, we now demonstrate that after engagement with the plasma membrane, SARS-CoV-2 undergoes rapid, clathrin-mediated endocytosis. This suggests that transfer of viral RNA to the cell cytosol occurs from the lumen of the endosomal system. Importantly, we further demonstrate that knockdown of clathrin heavy chain, which blocks clathrin-mediated endocytosis, reduces viral infectivity. These discoveries reveal that SARS-CoV-2 uses clathrin-mediated endocytosis to gain access into cells and suggests that this process is a key aspect of virus infectivity.
Rotating black hole in Rastall theory Kumar, Rahul; Ghosh, Sushant G.
European physical journal. C, Particles and fields,
09/2018, Letnik:
78, Številka:
9
Journal Article
Recenzirano
Odprti dostop
Rotating black hole solutions in theories of modified gravity are important as they offer an arena to test these theories through astrophysical observation. The non-rotating black hole can be hardly ...tested since the black hole spin is very important in any astrophysical process. We present rotating counterpart of a recently obtained spherically symmetric exact black hole solution surrounded by perfect fluid in the context of Rastall theory, viz, rotating Rastall black hole that generalize the Kerr–Newman black hole solution. In turn, we analyze the specific cases of the Kerr–Newman black holes surrounded by matter like dust and quintessence fields. Interestingly, for a set of parameters and a chosen surrounding field, there exists a critical rotation parameter (
a
=
a
E
), which corresponds to an extremal black hole with degenerate horizons, while for
a
<
a
E
, it describes a non-extremal black hole with Cauchy and event horizons, and no black hole for
a
>
a
E
with value
a
E
is also influenced by these parameters. We also discuss the thermodynamical quantities associated with rotating Rastall black hole, and analyze the particle motion with the behavior of effective potential.
Understanding the complex nature of wear behavior of materials at high-temperature is of fundamental importance for several engineering applications, including metal processing (cutting, forming, ...forging), internal combustion engines, etc. At high temperatures (up to 1000 °C), the material removal is majorly governed by the changes in surface reactivity and wear mechanisms. The use of lubricants to minimize friction, wear and flash temperature to prevent seizing is a common approach in engine tribology. However, the degradation of conventional liquid-based lubricants at temperatures beyond 300 °C, in addition to its harmful effects on human and environmental health, is deeply concerning. Solid lubricants are a group of compounds exploiting the benefit of wear diminishing mechanisms over a wide range of operating temperatures. The materials incorporated with solid lubricants are herein called 'self-lubricating' materials. Moreover, the possibility to omit the use of conventional liquid-based lubricants is perceived. The objective of the present paper is to review the current state-of-the-art in solid-lubricating materials operating under dry wear conditions. By opening with a brief summary of the understanding of solid lubrication at a high temperature, the article initially describes the recent developments in the field. The mechanisms of formation and the nature of tribo-films (or layers) during high-temperature wear are discussed in detail. The trends and ways of further development of the solid-lubricating materials and their future evolutions are identified.
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