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The research on entropy generation in a mechanical system is quite imperative owing to its immense applications in the production of advanced cooling devices and medical appliances. The basic need on this research is how to optimize the irreversibilities within the systems and channelize that energy towards the benefit. This study elucidates the entropy generation analysis of a Casson nanofluid near a stagnation point over a lubricated vertical wall. A thin film of shear-thinning liquid with power law index of 0.5 is employed on the wall to ensure the lubrication. The effect of induced magnetic field and the chemical reaction stimulated by the activation energy is also incorporated within the flow. The non-linear PDEs of the substantive problem along with the compatible interfacial and boundary conditions are reverted into ODEs with the aid of suitable similarity transformation, and then cracked numerically using the sixth-order Runge Kutta method assisted with Nachtsheim–Swigert shooting practice. One of the significant findings reveals that the fluid friction irreversibilities in the entropy generation are diminished with the magnetic parameter and the Casson parameter, whereas the thermal irreversibility predominates over the total entropy generation for the escalating values of the activation energy parameter. [ABSTRACT FROM AUTHOR]

The present study covers the fabrication of flexible piezoelectric nanogenerators and their application towards sustainable power generation. The rod-like structure of erbium-doped ZnO (EZ) nanoparticles prepared by the hydrothermal synthesis route was successfully incorporated inside the polyvinylidene fluoride (PVDF) matrix using the solution casting method. Solution casting is an easy and cost-effective method for fabricating laminated, thin, flexible and lightweight EZ-PVDF nanocomposite films. The formation of the desired crystallographic phase of EZ-PVDF nanocomposite films and the presence of rod-like EZ nanoparticles inside the PVDF matrix were confirmed using X-ray diffraction and FESEM. The enhancement of the β-phase fraction of the EZ-PVDF nanocomposite films as compared to bare PVDF was estimated using FTIR spectroscopy. The presence of a ferroelectric phase in the EZ-PVDF nanocomposite films was found due to the formation of a large area of interfaces between the EZ nanoparticles and the PVDF matrix. The maximum polarizations of 0.00696 μC cm-2 and 0.00683 μC cm-2 for two samples (EZP1 and EZP2, respectively) were observed at an electric field of 1.25 kV cm-1. The piezoelectric voltages were observed at relatively low frequencies for both nanocomposite films. The maximum piezoelectric voltages of 18.9 V and 15.5 V were observed at a 1 Hz frequency for EZP1 and EZP2, respectively. The output piezoelectric current of 16.88 mA and the maximum power density of 7773.68 W m-3 for EZP1 ensure its potential as an efficient piezoelectric nanogenerator with greater efficiency than those reported previously in published articles. The change in the piezoelectric voltage response of the nanocomposite films as a function of mechanical movement of human external body parts renders them the most suitable candidate for human--machine interfacing (HMI) applications, such as bending sensors and human motion sensors. [ABSTRACT FROM AUTHOR]

This research is focused on the examination of an unsteady flow of an electromagnetic nanofluid close to a stagnation point over an expanded sheet kept horizontally. Buongiorno's nanofluid model is revised with the combined influence of the externally applied electric and magnetic fluxes. Moreover, the underneath surface offers multiple slips into the nanofluid flow. The leading partial differential equations (PDE) are renovated to the nonlinear ordinary differential equations (ODE) with the assistance of similarity transformations. Thus, the outcomes are received numerically by using the RK-6 with Nachtsheim–Swigert shooting technique. The enlistment of the outcomes for the momentum, energy and concentration profiles along with the skin-friction coefficient (C f x ∗) , Nusselt number (Nu x ∗) and Sherwood number (Sh x ∗) for several parametric values are presented in a graphical and tabular form and discussed in detail. The variation of streamlines with respect to the unsteadiness parameter is also recorded. Statistical inspection reveals that the flow parameters are highly correlated with the wall shear stress, wall heat and mass fluxes. Findings indicate that the escalation of electric flux tries to intensify the hydrodynamic boundary layer meanwhile the magnetic flux assists to stabilize the growth by reducing it for both the steady and unsteady flow patterns. Influence of velocity slip parameter ξ from 0.0 to 1.5 causes the reduction in Nu x ∗ by 16.98% for steady flow while 60.27% for time-dependent flow case. Moreover, we expect that these theoretical findings are very much helpful for several engineering and industrial applications such as polymer sheet productions, manufacturing automobile machines, cooling microelectronic chips, etc. [ABSTRACT FROM AUTHOR]

The COVID-19 is recognized as one of the deadly disease in the history of human life. It is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Since its first case appeared in December 2019 in Wuhan, China, number of COVID-19 cases are still growing worldwide, till now number of confirmed COVID-19 cases reported globally are 594 million and number of fatalities are 6.29 million. It creates panic situation on every individual as well as put an extraordinary challenge on every country, especially on the health care system. The ruthlessness of the disease and its noxious complexities need development of suitable and effective drug on urgent basis to prevent as well as treat COVID-19. Though specific drug with proper efficacy is not yet found, a number of research and clinical trials are still going on to check the suitability and effectiveness of existing drug, i.e. repurposed drug to treat patients of COVID-19. In this article, repurposed drug—arbidol, baricitinib, favipiravir, galidesivir and ribavirin are reported by using Conceptual Density Functional Theory (CDFT) approach. Optimization energy, spin multiplicity, zero point energy correction, CDFT-based descriptors, optical and thermochemical properties of these repurposed drugs are computed and analysed. Result signify that favipiravir is the most reactive compound whereas ribavirin is found as the most stable among these molecular species. Favipiravir has the lowest thermal energy, heat capacity and entropy, whereas arbidol has the maximum thermal energy, heat capacity and entropy. There is an interesting correlation found between optimization energy, zero point energy correction, polarizability and thermochemical properties of these repurposed drugs. [ABSTRACT FROM AUTHOR]

In this report, for the first time, Co2U-type hexaferrite (Ba4Co2Fe36O60) nanomaterials have been considered along with their conjugation with a poly(vinylidene fluoride) (PVDF) matrix for the fabrication of heterostructure composite materials with superior electromagnetic interference shielding effectiveness (SE) that can produce better attenuation of microwave radiation. The high value of magnetizations of ∼7.21 and 10.63 emu/g is significant for the improvement of the shielding effectiveness due to absorption (SEA) of the composite materials. The unique combination of magnetic and dielectric responses of these Co2U-type hexaferrite nanomaterials helps to get significantly high total shielding effectiveness (SET) in their PVDF composite states within the frequency range of 8–18 GHz. A very high value of SET of approximately −83 dB at 14.2 GHz with >99.999 999% of attenuation of incident radiation has been observed for the Co2U-type hexaferrite–PVDF composite materials. The β-phase modified PVDF structure also plays the most important role to generate induced polarization inside the structure of composite materials. Also, this PVDF matrix provides the application friendly laminated structure of Co2U-type hexaferrite–PVDF composite materials. Structural, morphological, and chemical studies reveal the presence of the polycrystalline phase of Co2U-type hexaferrite and β-phase crystallization of polar PVDF in the multi-phase Co2U-type hexaferrite–PVDF composite materials. This study has helped us to understand the importance of magnetic Co2U-type hexaferrite nanomaterials for the fabrication of lightweight, large area, flexible, and thickness-controlled radar absorbing materials to combat against electromagnetic pollution. [ABSTRACT FROM AUTHOR]

The article discusses the use of density functional theory (DFT) in computational chemistry and physics. DFT is a quantum mechanical theory that is widely used to calculate the properties of molecules and materials. It has been applied to various areas of research, including superconductivity, laser impulses, and magnetic characteristics. The article also mentions the limitations of DFT and the development of conceptual DFT. The special issue of the journal focuses on the parameters of conceptual DFT, particularly in relation to chemical reactivity. It includes 18 manuscripts that explore various aspects of CDFT. The goal of the special issue is to facilitate the exchange of ideas and provide a platform for experts to discuss solutions to persistent problems. [Extracted from the article]

[Display omitted] • Co 2 Y-hexaferrite-MoS 2 -PVDF nanocomposite film. • Non-Conducting Polymer Jacket Coated Multi-Layer structure. • Room temperature high magnetic moment of 33.32 emu/g. • High SE A has been observed −51.23 dB at 14.03 GHz frequency. • Potential candidate for EMI shielding application. This article represents the imposing electromagnetic interference (EMI) shielding behaviour of non-conducting polymer jacket-coated Co 2 Y-hexaferrite-MoS 2 binary nanofillers incorporated PVDF multi-layer nanocomposite films. The presence of Co 2 Y-hexaferrite inside PVDF enhanced the magnetic permeability, whereas the incorporation of semiconducting transition metal dichalcogenide (TMDC), MoS 2 , inside the PVDF matrix improves the polarization effects of the nanocomposite films. The crystalline phases corresponding to Co 2 Y-hexaferrite, MoS 2 nanoparticles and the multi-phase nanocomposite films have been justified using XRD analysis and Rietveld refinement study. FESEM micrographs confirm the hexagonal and cotton-ball structures of Co 2 Y-hexaferrite and MoS 2 nanoparticles, respectively; in addition, the presence of Co 2 Y-MoS 2 binary nanofillers inside the PVDF matrix has been confirmed. The stability of the nanocomposite films against electrical breakdown is clearly demonstrated by the minimum leakage current observed at 90 kV/m under J-E characteristics. The room temperature maximum magnetization of 33.32 emu/g of Co 2 Y-hexaferrite at an external magnetic field of 50,000 Oe helps in incurring magnetic losses and the corresponding improvement of shielding effectiveness due to absorption (SE A) of the nanocomposite films. This article demonstrates the modulation of SE A of the nanocomposite films depending on both the binary nanofillers loading percentage inside PVDF and the thickness of the nanocomposite films. Also, a unique mechanism corresponding to the coating of a non-conducting polymer jacket over a multi-layer structure has been opted herein to improve SE A in the frequency range of 12–18 GHz. This unique mechanism demonstrates that the maximum SE A for the non-conducting polymer jacket-coated multi-layer nanocomposite film is −51.23 dB at 14.03 GHz, and the corresponding total shielding effectiveness (SE T) is −74.51 dB at 13.23 GHz, along with > 99.9999 % attenuation. [ABSTRACT FROM AUTHOR]

Intense droughts in recent years are a global concern. The duration and timing of drought for forests have not been researched as much as crops. This study aims to utilize big earth data to analyse the consequences of drought on forest based on drought and vegetation indices derived from remote sensing. The study area is Sal Forest (Shorea robusta) in Bangladesh. Vegetation indices such as NDVI and EVI are correlated with drought indices for the years 2000–2020. The data is collected via Google Earth Engine and the R statistical software environment is used for data analysis. Seasonal adjustment was conducted to remove the biases due to seasonality. Results showed that the timing for the loss of forest vitality is dependent on drought severity. Lagged correlation was used to identify the lags between drought severity and vitality via drought and vegetation indices. From 2000 to 2020, the intensity of drought was moderate (0.95). There is a lag between drought and a decrease in forest vitality. This lag decreases as the severity and duration of drought increase. Severe droughts in Sal Forest create an almost immediate impact with worsening conditions but show a lag of 3–4 months and 2–3 months for low and moderate drought severity, respectively. The NDVI anomaly shows that drought has adverse effects during growth periods. The methodology of this study can be replicated across various forest types, and further improvements would require in situ data coupled with phenological observations. [ABSTRACT FROM AUTHOR]

• Co 2 Z-hexaferrite/rGO/PVDF multi-layers nanocomposites film. • Ferromagnetic nature at RT. • SE A has been observed −54.09 dB at 15.70 GHz frequency. • Co 2 Z-hexaferrite/rGO/PVDF nanocomposite film: potential candidate for EMI shielding application. This report shows impressive electromagnetic interference (EMI) shielding efficiency of laminated nanocomposites of PVDF containing binary nanofillers of rGO and Co 2 Z hexaferrite. These rGO layers in the PVDF matrix in association with magnetic nanofillers have been considered to improve interfacial polarization by accumulating charges at the interfaces of rGO-Co 2 Z hexaferrite-PVDF system. The crystallographic phase, chemical composition, and successful incorporation of the binary nanofillers into PVDF have been verified using XRD, XPS, RAMAN, and FESEM analysis. The J-E analysis of rGO-Co 2 Z hexaferrite-PVDF nanocomposite films confirm that the current density of all the nanocomposite films is very less and found in the order of 10-5 A/m2 under the maximum electric field of 70 kV/m. This indicates the emergence of polarization effect in the nanocomposite films when subjected to high external electric field without having electrical breakdown. The significant magnetization of ∼8.9 emu/g for nanocomposite films, at room temperature is beneficial for boosting the EMI shielding effectiveness due to absorption (SE A). The combination of magnetization and electrical polarization in nanocomposite film helps to attain significantly high total shielding effectiveness (SE T) in the frequency range of 12–18 GHz. The shielding effectiveness study of both mono-layer and multi-layer nanocomposite films have been investigated. Improvement of SE A has also been achieved by the elevation of the thickness of the nanocomposite film within the range of 0.8 to 1.0 mm, which in turn improves SE T to a value of −54.09 dB at 15.70 GHz for multi-layer system of thickness 0.861 mm with >99.999 % of attenuation whereas the mono-layer film of thickness 0.180 mm shows the SE T of −47.03 dB at 14.76 GHz with an attenuation of >99.99 %. [ABSTRACT FROM AUTHOR]

A generalized way to define Minkowski spaces as Banach spaces permits to define with the aid of a metric vector generalized scalar products and hence generalized norms. The possible nullity of some norms in Minkowski spaces leads to define Minkowski hypersurfaces, which can be connected to multidimensional energy surfaces. [ABSTRACT FROM AUTHOR]

Magnetizability (ξ) is an effective yet less explored periodic descriptor. It plays a pivotal role in exploring and elucidating chemical–magnetic interactions. Owing to scarcity of a scale of magnetizability and its atomic data, an empirical relation between magnetizability and radius has been proposed. Magnetizabilities have been computed for atoms of 102 elements of the periodic table. Computed values follow periodicity, observe all sine qua non of periodic properties and obey the minimum magnetizability principle. Also, they present a reasonable relationship with polarizability and ionization potential. An excellent correlation between the calculated molecular magnetizabilities and the existing data strengthens our motivation towards this work. [ABSTRACT FROM AUTHOR]

This report describes the magnetoelectric multiferroic property of Mn 0.5 Cu 0.2 Zn 0.3 Fe 2 O 4 (MCZF) nanofillers embedded PVDF nanocomposite films. The crystallographic phases were confirmed by XRD analysis. MCZF nanofillers inside PVDF were observed in FESEM micrographs. The presence of the magnetic ordering in MCZF-PVDF films and its variation by altering the weight percentage of MCZF-nanofillers in PVDF matrix was found. Nonlinear nature of P-E loop of MCZF-PVDF films clearly indicates room temperature ferroelectric ordering in MCZF-PVDF films. A clear transition from ferroelectric to paraelectric behaviour was also observed in the MCZF-PVDF films. The dielectric response with change in static magnetic field was investigated to show the presence of coupling between magnetic and ferroelectric orderings. These results confirm the presence of type-II multiferroic behaviour owing to the magnetostrictive and piezoelectric phases in MCZF-PVDF films. This novel magnetoelectric multiferroic property of MCZF-PVDF laminated nanocomposite films is very much useful for various device applications. [Display omitted] • Mn–Cu–Zn-Ferrite-PVDF nanocomposites were prepared by the solution casting method. • Nanocomposites are light weight, flexible, and cost effective. • Magnetisation study of Mn–Cu–Zn-Ferrite-PVDF shows at RT. • PE-loop study reveal the presence of polarization of Mn–Cu–Zn-Ferrite-PVDF nanocomposite. • Magnetodielectric study of Mn–Cu–Zn-Ferrite-PVDF shows the presence of multiferroic property. [ABSTRACT FROM AUTHOR]

Y-type strontium hexaferrite (SrY) nanoparticles are prepared by sol gel synthesis route and the nanoparticles are taken with graphene oxide (GO) and reduced graphene oxide (rGO) separately to prepare SrY/GO and SrY/rGO binary nanofillers. These two binary nanofillers reinforced PVDF mono-layer and multi-layer nanocomposite films (SrY/GO/PVDF and SrY/rGO/PVDF) have been prepared to analyse their complex permeability and permittivity, microwave absorption ability in 8–12 GHz (X-band) range. The crystallographic phase, chemical composition and the successful incorporation of the binary nanofillers inside PVDF was confirmed by XRD, XPS, RAMAN and FESEM analysis. J-E characterization of SrY/rGO/PVDF and SrY/GO/PVDF films verify the occurrence of conductive channels inside PVDF matrix for former and the development of polarization effect for later under external electric field. The high magnetization and coercivity of ∼28.24 emu/g and 1200 Oe at room temperature (RT) corresponding to SrY nanoparticles is favourable at incurring high magnetic losses for X-band. A remarkable enhancement in total shielding effectiveness (SE T) from −63.16 dB to −82.53 dB has been observed for multi-layer SrY/GO/PVDF films as compared to its mono-layer structure. The majority of the contribution for SE T is the shielding effectiveness due to absorption (SE A) (−60.11 dB) as compared to the same for reflection (SE R) (−24.26 dB) at a matching frequency of ∼9.6 GHz. However, in case of SrY/rGO/PVDF films the predominance of SE R over SE A has been observed. Therefore, our results could act as a pathway in devising a graphene/polymer-based magneto-electric laminated nanocomposite system for lightweight and customized microwave shield within the X-band frequency. [Display omitted] • Y-type hexaferrite-graphene derivatives-PVDF multi-layered nanocomposite films prepared. • Magnetization of ∼28.24 emu/g and coercivity of 1200 Oe of Y-type hexaferrite have been found. • SE T has been observed −82.53 dB at 9.6 GHz frequency. • Nanocomposite films are found suitable for high SE T with modulated SE A and SE R in X-band. [ABSTRACT FROM AUTHOR]

Atomic radius plays a key role in the realm of science to understand atomic/molecular physico-chemical properties. Looking at the enormous potential this descriptor has, a model is proposed for absolute radius (r) in terms of electrophilicity index (ω). Atomic radii for 103 elements of the periodic table are reported. Considering the periodic relationship between absolute radius and atomic electrophilicity, this empirical model is proposed invoking regression analysis. The computed radii obey sine qua non of periodic properties. Relativistic effects are also distinct in the newly computed radii. On comparison, the computed data is noted to be in close conformity with the reported radii. Further, some size-dependent properties are calculated by employing the computed absolute radius. These present a substantial periodic behaviour and association with absolute radii. [ABSTRACT FROM AUTHOR]

A new principle known as Minimum Magnetizability Principle has recently been introduced in the context of Density Functional Theory. In order to validate this principle, changes in the magnetizability (Δξ) and its cube-root (Δξ1/3) are computed at B3LYP/LanL2DZ level of theory for some elementary chemical reactions. The principle is found to be valid for 77% of reactions under study. It is observed that the molecules with the lowest sum of ξ or ξ1/3 are generally the most stable. The principle fails to work in the presence of hard species. A comparative study is also made with change in hardness (Δη), electrophilicity index (Δω), polarizability (Δα) and their cube-roots (Δη1/3, Δω1/3, Δα1/3). It is observed that the Minimum Magnetizability Principle is nearly as reliable as Minimum Electrophilicity Principle. It appears that this principle could be helpful in predicting the direction of diverse reactions as well as stable geometrical arrangements. [ABSTRACT FROM AUTHOR]

Detection of entangled states from experimental magnetic susceptibility is reported for an organic radical. The present system exemplifies an ideal spin ½ chain with full isotropy. Experimental susceptibility data are modelled by the formulation described by Bonner and Fisher. An explicit correlation is established between the molecular structure and the spin chain interaction. Using experimental magnetic susceptibility as entanglement witness, entanglement is observed to exist up to 28 K in the present system. Evolution of entanglement with magnetic field is also studied and a surface plot is generated, which clearly exhibits the variation of entanglement with magnetic field and temperature. [ABSTRACT FROM AUTHOR]

Electrophilicity index (ω) is an important theoretical construct of atoms and molecules and is widely used to understand various chemical phenomena and determine physico-chemical properties. Accordingly, it becomes useful to find an accurate expression for it which is free from any inconsistencies. In view of this, a simple yet rigorous expression is proposed to compute Electrophilicity Index. Since our model is based on ionization potential and electron affinity, it provides a more reliable measure for any electronic changes taking place in a species. Our suggested definition is free from any operational and dimensional discrepancies. We have reported atomic electrophilicity indices for 74 elements of the periodic table invoking our proposed ansatz. The proposed model follows all the sine qua non of existing scale of electrophilicity index. Electrophilicity Equalization Principle is also validated through our computed values. In general, the new expression appears to be powerful and suitable for application in diverse realms. [ABSTRACT FROM AUTHOR]

Electronegativity (χ) is an important physico-chemical concept to study the chemical structure and reactivity. Although, the conundrum related to measurement of electronegativity still persists. In view of this fact, a simple yet rigorous scale of electronegativity (χ), invoking an inverse relationship with atomic nucleophilicity index (N), has been proposed for 103 elements of the periodic table. The computed data follows periodicity distinctly satisfying all the sine qua non of a standard scale of electronegativity. Further, electronegativity values display a sound similarity with the standard electronegativity scales validating the suitability of the proposed model. Molecular electronegativities of some polyatomic molecules have also been calculated using the proposed scale of electronegativity. [ABSTRACT FROM AUTHOR]

Multicopper oxidases (MCOs) are produced by microscopic and macroscopic fungal species and are involved in various physiological processes such as morphogenesis, lignin degradation, and defense mechanisms to stress inducing environmental conditions as well as fungal virulence. This review will summarize our current understanding regarding the functions of MCOs present in Saccharomyces cerevisiae and in different human fungal pathogens. Of the two main MCO groups, the first group of MCOs is involved in iron homoeostasis and the second includes laccases. This review will also discuss their role in the pathogenesis of human fungal pathogens. [ABSTRACT FROM AUTHOR]

Geometrical structures, relative stabilities and electronic properties of neutral, cationic and anionic pure gold A u n + 1 λ {\rm{A}}u_{n + 1}^\lambda and Ag-doped bimetallic AgAu n λ (λ = 0 , ± 1 ; n = 1 - 12) {\rm{AgAu}}_n^\lambda \left({\lambda = 0, \pm 1;n = 1 - 12} \right) clusters have been systematically investigated by using density functional theory methodology. The optimized structures show that planar to three-dimensional structural transition occurs at n = 5 for cationic clusters. Due to strong relativistic effect of Au clusters, the ground state configurations of neutral and anionic bimetallic clusters favor planar geometry till n = 12. Silver atoms tend to occupy the most highly coordinated position and form the maximum number of bonds with Au atoms. The computed HOMO-LUMO energy gaps, fragmentation energies and second-order difference of energies show interesting odd-even oscillation behavior. The result indicates that AgAu5, AgAu 2 + {\rm{AgAu}}_2^ + and AgAu 2 - {\rm{AgAu}}_2^ - are the most stable clusters in this molecular system. The DFT based descriptors of bimetallic clusters are also discussed and compared with pure gold clusters. The high value of correlation coefficient between HOMO-LUMO energy gaps and DFT based descriptors supports our analysis. A good agreement between experimental and theoretical data has been obtained in this study. [ABSTRACT FROM AUTHOR]

The study of bimetallic nanoalloy clusters is of considerable interest due to its interesting electronic, optical, magnetic and catalytic properties. The geometrical structure and electronic properties of AunPt (n = 1–8) nanoalloy clusters are studied by using the density functional theory methodology. The result exhibits that the ground-state configurations of AunPt clusters favour planar confirmation in this molecular range. The most stable cluster is Au3Pt, which is having rhombus structure with symmetry group C2v and can be considered as building blocks for developing large clusters. The computed HOMO-LUMO energy gap of Au3Pt nanoalloy cluster is 1.741 eV. The energy gap in this particular range supports the use of bimetallic clusters as nonlinear optical devices and optoelectronic materials. The DFT-based global descriptors viz. HOMO-LUMO energy gap, electronegativity, hardness, softness and electrophilicity index are also studied. The computed HOMO-LUMO energy gap and chemical hardness exhibit a pronounced odd-even oscillation behaviour as a function of cluster size, n. [ABSTRACT FROM AUTHOR]

Eicosanoids are bioactive lipid mediators generated in almost all mammalian cells from the oxidation of arachidonic acid and other related twenty-carbon polyunsaturated fatty acids (PUFA). Eicosanoids regulate various physiological functions, including cellular homoeostasis and modulation of inflammatory responses in mammals. The mode of action of these lipid mediators depend on their binding to different G-protein coupled receptors. The three main enzymatic pathways associated with their production are the COX pathway, LOX pathway and cytochrome P450 pathway. Interestingly, investigations have also revealed that several human pathogenic fungi are capable of producing these bioactive lipid mediators; however, the exact biosynthetic pathways and their function in pathogenicity are not yet extensively characterized. The aim of the current review is to summarize the recent discoveries pertaining to eicosanoid production by human pathogenic yeasts with a special focus on the opportunistic human fungal pathogen Candida parapsilosis. [ABSTRACT FROM AUTHOR]

In this study, several simple aspects associated with the periodic table (PT) of the elements are commented. First, the connection of the PT with the structure of a seven‐dimensional Boolean hypercube leads afterward to discuss the nature of those PT elements bearing prime atomic numbers. Second, the use of quantum similarity (QS) to obtain an alternative insight on the PT element relations will be also developed. The foundation of the second part starts admitting that any element of the PT can be attached to a schematic electronic density function, constructed with a single Gaussian function: a Gaussian atomic density function, allowing to consider the PT elements as a set of quantum objects, and permits a straightforward construction of a QS matrix. Such QS scheme can be applied to the whole PT or to any subset of it. Manipulation of the QS matrices attached to any quantum object set allows the evaluation of statistical‐like values, acting as coordinates to numerically or graphically represent the chosen PT atomic element sets. © 2019 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

The present study deals with the possibility that N-dimensional hypercubes vertices could be constructed with chosen sets, composed by a given number of n elements. That is by: n-ary sets. Application of this possibility is discussed using as examples the coloring of graphs and the Erdös–Faber–Lovász conjecture, as well as protein and RNA descriptions. The outcome of this discussion induces a possibility to use p-dimensional hypercube vertices themselves as the possible elements of the n-ary sets as generators of N-dimensional hypercubes. Thus, providing: n = 2 p . [ABSTRACT FROM AUTHOR]

Although in the last decade several fact-checking organizations have emerged to verify misinformation, fake news has continued to proliferate, especially through social media platforms. Even though adopting improved detection strategies is of utmost importance, the fact-checking process could be optimized by verifying whether a claim has been previously fact-checked. Despite some ad-hoc information retrieval approaches having been recently proposed, the utility of modern (neural) retrieval systems have not been investigated yet. In this paper, we consider the standard two-phases retriever-reranker architecture and benchmark different state-of-the-art techniques from the information retrieval and Q&A literature. We design several experiments on a real-world Twitter dataset to analyze the efficiency and the effectiveness of the benchmark approaches. Our results show that combining standard and neural approaches is the most promising research direction to improve retrievers performance and that complex (neural) rerankers might still be efficient in practice since there is no need to process a high number of documents to improve ranking performance. • We address the problem of detecting previously fact-checked information. • Considering the information retrieval task, we define a multi-stage retriever-reranker framework. • We benchmark the state-of-the-art retriever and re-ranker architectures. • We discuss the system's operational settings unveiling its strengths and weaknesses. [ABSTRACT FROM AUTHOR]

Knowledge of the nature of a chemical reactivity descriptor holds immense value to theoretical scientists. An appreciable number of works have been carried out in this realm. Polarizability (α) is one amongst such constructs. Fundamentally, it is a linear response of a systems electron cloud to an external applied electric field. The concept of polarizability is being widely adopted in the contemporary world of chemistry; however a suitable scale of measurement of atomic polarizability is still to be designed. In this work, an ansatz to compute atomic static dipole polarizability is proposed considering the conjoint action of absolute radius (r) and electronegativity (χ) for 103 elements of periodic table. We have evaluated the data invoking regression analysis. The computed data mirrors the periodicity remarkably satisfying all the sine qua non of a standard scale of polarizability. It presents an excellent quantitative correlation with ionization energy. Further, molecular polarizability (αm) is determined conceptualizing the property of additivity. A superior correlation between theoretical vis-à-vis existing molecular polarizabilities is observed. [ABSTRACT FROM AUTHOR]

A model for computing the atomic compressibility (β) based on two periodic descriptors, namely, absolute radius (r) and atomic electrophilicity index (ω), is proposed as β ∝ r 2 / ω The ansatz is invoked to compute compressibilities of atoms of 57 elements of the periodic table. The computed atomic data exhibits all sine qua non of periodic properties. Further, the concept group compressibility (Gβ) is also established invoking additivity property using some molecules with different functional groups and consequently utilized in correlating with molecular polarizability. Since toxicity prediction is an imperative need of the hour, chemical reactivity descriptors are of paramount importance in the study of toxicological behaviour along with a lot of other molecular reactivity studies within a Quantitative Structure–Activity Relationship (QSAR) context. Hence, this quantity is applied in the modelling of toxicological property through QSAR and a comprehensive study is performed in an effort to investigate and validate the application of compressibility in determining its toxicological power. Consequently, varied 209 organic molecules are selected for studying the toxic effect on Tetrahymena pyriformis. A QSAR model is constructed in terms of compressibility which offers a superior prediction of toxicity independently without adopting additional descriptors or properties as in some other QSAR studies. [ABSTRACT FROM AUTHOR]

The impression of multiple convective conditions on Falkner‐Skan flow along a permeable static/moving wedge is demonstrated here. The Carreau nanofluid model depending on the power law index is incorporated with the effects of thermophoresis and Brownian motion. A suitable similarity conversion is consumed to bring out the nonlinear ordinary differential equations (ODEs) from the partial differential system. The transformed system is tackled via analytical and numerical procedure by homotopy perturbation method and RK‐5 with shooting technique, respectively. Numerical computations assert that the growth of concentration and temperature boundary layer widths are in an inversely proportional relation to the permeability of the medium, whereas reverse effect is observed for conduction convection and conduction diffusion parameters. Also, with the enhancement of Brownian motion parameter, the rate of heat transport gets reduced for static wedge by 14.25% whereas for moving wedge the reduction is 10.61%. Another significant observation shows that the growth in mass transport with conduction diffusion is 17.65% greater for moving wedge in contrast to static one in accordance with other governing parameters. [ABSTRACT FROM AUTHOR]

Nano clusters of Copper sulfides (CuS) have paramount importance due to its significant adsorption property and non-toxic behaviour. In this report, nanoalloy clusters of (CuS)n; (n = 1-8) have been theoretically analyzed in terms of Conceptual Density Functional Theory (CDFT) based descriptors, aiming to explore its electronic and other properties. Global DFT based descriptors have been computed for ground state configurations and low-lying isomers of (CuS)n clusters. Computed HOMO-LUMO gaps, lying in the range of 1.25-3.53 eV, indicate that (CuS)n clusters may be utilized as renewable energy sources specially in photocatalysis and solar cell applications. A statistical correlation has been established between electronic and photo-catalytic properties of copper-sulfide clusters with their computational counterparts. The close agreement between experimental and computed data supports our analytical approach. [ABSTRACT FROM AUTHOR]

Abstract While there has been a plethora of approaches for detecting disjoint communities from real-world complex networks, some methods for detecting overlapping community structures have also been recently proposed. In this work, we argue that, instead of developing separate approaches for detecting overlapping communities, a promising alternative is to infer the overlapping communities from multiple disjoint community structures. We propose an ensemble-based approach, called EnCoD, that leverages the solutions produced by various disjoint community detection algorithms to discover the overlapping community structure. Specifically, EnCoD generates a feature vector for each vertex from the results of the base algorithms and learns which features lead to detect densely connected overlapping regions in an unsupervised way. It keeps on iterating until the likelihood of each vertex belonging to its own community maximizes. Experiments on both synthetic and several real-world networks (with known ground-truth community structures) reveal that EnCoD significantly outperforms nine state-of-the-art overlapping community detection algorithms Finally, we show that EnCoD is generic enough to be applied to networks where the vertices are associated with explicit semantic features. To the best of our knowledge, EnCoD is the second ensemble-based overlapping community detection approach after MEDOC Chakraborty (2016). [ABSTRACT FROM AUTHOR]

Most past work on honeypots has made two assumptions: (i) they assume that the only defensive measure used is a honeypot mechanism, and (ii) they do not consider both rational and subrational adversaries and do not reason with an adversary model when placing honeypots. However, real-world system security officers use a mix of instruments such as traditional defenses (e.g. firewalls, intrusion detection systems), and honeypots form only one portion of the strategy.Moreover, the placement of traditional defenses and honeypots cannot be done independently. In this paper, we consider a Stackelbergstyle game situation where the defender models the attacker and uses that model to identify the best placement of traditional defenses and honeypots. We provide a formal definition of undamaged asset value (i.e. the value that is not compromised by the attacker) under a given defensive strategy and show that the problem of finding the best placement so as to maximize undamaged asset value is NP-hard.We propose a greedy algorithm and show via experiments, both on real enterprise networks and on ones generated by the well-known network simulation tool NS-2, that our algorithm quickly computes near optimal placements. As such, our method is both practical and effective. [ABSTRACT FROM AUTHOR]

Detecting and analyzing dense groups or communities from social and information networks has attracted immense attention over the last decade due to its enormous applicability in different domains. Community detection is an ill-defined problem, as the nature of the communities is not known in advance. The problem has turned even more complicated due to the fact that communities emerge in the network in various forms such as disjoint, overlapping, and hierarchical. Various heuristics have been proposed to address these challenges, depending on the application in hand. All these heuristics have been materialized in the form of new metrics, which in most cases are used as optimization functions for detecting the community structure, or provide an indication of the goodness of detected communities during evaluation. Over the last decade, a large number of such metrics have been proposed. Thus, there arises a need for an organized and detailed survey of the metrics proposed for community detection and evaluation. Here, we present a survey of the start-of-the-art metrics used for the detection and the evaluation of community structure. We also conduct experiments on synthetic and real networks to present a comparative analysis of these metrics in measuring the goodness of the underlying community structure. [ABSTRACT FROM AUTHOR]

A theoretical model on carbon nanotube-based upper convective Maxwell nanofluid flow with thermal and velocity slip boundary conditions is thoroughly presented here. To formulate the viscoelastic relaxation framework on boundary layer flow uniquely, Cattaneo-Christov heat flux model is employed in the momentum equation. The dominating equations and boundary conditions are turned into system of ordinary boundary value problem by using proper transformations, and hence, the similarity solutions are gained numerically by applying Runge-Kutta fourth-order method with shooting practice. The impacts of the governing parameters upon the flow and temperature are represented in tabular as well as in graphical form and discussed in detail. The findings elucidate that both the velocity and temperature are inverse functions of thermal relaxation time for single-walled and multi-walled carbon nanotube-based nanofluids. Fluid relaxation parameter is positively correlated with skin friction and rate of heat transport for both types of nanofluids, but the temperature slip makes a contrary with the same. [ABSTRACT FROM AUTHOR]

Lipid mediators, derived from arachidonic acid metabolism, play an important role in immune regulation. The functions of bioactive eicosanoids range from modulating cytokine signaling and inflammasome formation to anti-inflammatory and pro-resolving activities. Human pathogenic fungi such as Candida albicans, Candida parapsilosis, Cryptococcus neoformans and Aspergillus fumigatus have been shown to produce such lipid mediators, associated with their virulence. To date, investigations into the molecular mechanisms of fungal eicosanoid biosynthesis in different species have revealed that several genes are associated with prostaglandin production. However, these routes remain uncharacterized in C. parapsilosis with early results suggesting it uses pathways distinct from those found in C. albicans. Therefore, we aimed to identify and characterize C. parapsilosis genes involved in eicosanoid biosynthesis. Following arachidonic acid treatment of C. parapsilosis cells, we identified several genes interfering with prostaglandin production. Out of the identified genes, homologues of a multi copper oxidase (FET3), an Acyl-CoA thiolase (POT1) and an Acyl-CoA oxidase (POX1-3) were found to play a significant role in prostaglandin synthesis. Furthermore, all three genes were confirmed to enhance C. parapsilosis pathogenicity, as the corresponding deletion mutants were cleared more efficiently by human macrophages and induced higher levels of pro-inflammatory cytokines. In addition, the mutants were less virulent than the wild-type strain in a mouse model of systemic infection. Taken together, we identified three genes that regulate eicosanoid biosynthesis in C. parapsilosis and impact the fungus' virulence. [ABSTRACT FROM AUTHOR]

The current special issue of Neurocomputing was designed to encourage researchers from interdisciplinary domains working on multilingual social media analytics to think beyond the conventional way of combating online hostile posts. The special issue was primarily based on the theme of the First Workshop on Combating Online Hostile Posts in Regional Languages during Emergency Situation (CONSTRAINT) (https://lcs2.iiitd.edu.in/CONSTRAINT-2021/), held with AAAI'2021. We invited a few good quality papers accepted in CONSTRAINT to submit an extended version. We also made the call open for the general audience. The special issue broadly focused on three major points: (i) Regional language: the offensive posts under inspection may be written in low-resource regional languages (e.g., Tamil, Urdu, Bangali, Polish, Czech, Lithuanian, etc.). (ii) Emergency situation: The proposed solutions should be able to tackle misinformation during emergency situations where, due to the lack of enough historical data, learning models need to adopt additional intelligence to handle emerging and novel posts. (iii) Early detection: Since the impact of misinformation during emergency situations is highly detrimental to the society (e.g., health-related misadvice during a pandemic can cost human lives), we encourage the solutions to be able to detect such hostile posts as early as possible after their appearance on social media. [ABSTRACT FROM AUTHOR]

Detailed experimental investigation of thermal and magnetic properties are presented for Cu(NH 3 ) 4 SO 4 ·H 2 O, an ideal uniform Heisenberg spin ½ chain compound. A comparison of these properties with relevant spin models is also presented. Temperature dependent magnetic susceptibility and specific heat data have been compared with the exact solution for uniform Heisenberg chain model derived by means of Bethe ansatz technique. Magnetization isotherms measured as a function of field are analyzed using the numerical results simulated by Quantum Monte Carlo technique. Specific heat as a function of magnetic field (up to 7T) and temperature (down to 2 K) is reported. Subsequently, the data are compared with the corresponding theoretical curves for infinite Heisenberg spin ½ chain model with J = 6 K. Moreover, internal energy and entropy are calculated by analyzing the experimental specific heat data. Magnetic field and temperature dependent behavior of entropy and internal energy are in good agreement with the theoretical predictions. [ABSTRACT FROM AUTHOR]

The heat absorber uses in solar power plants have generally low energy adaptation owing to large emissive losses at high temperature. Recently, nanofluid based solar energy absorber have acknowledged immense scientific curiosity to competent share and store the thermal energy. Here we examine theoretically the natural convective flow of an Ag nanoparticle based nanofluid flow along an inclined flat sheet embedded in a Darcy-Forchheimer permeable medium coexistence of solar radiation. By use of similarity transformations, the fundamental partial differential system and boundary conditions are tackled numerically using Runge-Kutta Gill based shooting procedure. The impacts of governing parameters upon the flow, temperature, Nusselt number and skin friction coefficient are represented tabular as well as in graphical form. [ABSTRACT FROM AUTHOR]

The area of this research reveals the heat and mass transport of a Jeffrey nanofluid in the direction of a stagnation point coexisting with magnetic field and melting heat transport. The fundamental PDEs are converted to a set of nonlinear ODEs with the guidance of some appropriate similarity transformations. The result is gained analytically by Differential Transformation method (DTM) and a comparison with the numerical solutions obtained by Runge-Kutta Gill based shooting procedure is framed. Numerical outcomes for non-dimensional temperature, nanoparticle concentration, Nusselt number and Sherwood number for different parameters indulging the flow are offered through charts and figures. In occurrence of a magnetic flux, the melting heat effect enhances nanoparticle concentration distribution, whereas the reverse effect is noticed for temperature. Nusselt number falls with Thermophoresis and melting heat transport, while Sherwood number rises with magnetic field and stretching ratio of the sheet. [ABSTRACT FROM AUTHOR]

• X-type hexaferrite-PVDFnanocompositeswere prepared by the solution casting method. • Nanocompositesare light weight, flexible, andcost effective. • EMI SE is high, attenuation is high, and the band width is high ∼6 GHz. • In GHz region,complexpermeability and permittivity are responsible for high SE. • X-type hexaferrite-PVDF: most efficient for the fabrication of EMI shielding jacket. In the present report, X-type hexaferrite-poly(vinylidene fluoride) laminated nanocomposite films have been fabricated by the solution casting method. The coexistence of a large magnetic moment of these X-type hexaferrite nanoparticles and a large electric dipole moment of polar PVDF matrix in the nanocomposite state make them more suitable for a wide range of EMI shielding applications. The high EMI shielding effectiveness of −69.5 dB at 9.9 and 11.7 GHz and −84.8 dB at 12.5 GHz and −83.8 dB at 14.1 GHz by the nanocomposite films have been observed. The high attenuation (>99.999999%) and wide bandwidth offers a completely unique nanocomposite material for the fabrication of affluent Radar Absorbing Materials (RAMs) to perform against the pollution caused by the high frequency EM radiations. Herein, the article also proposes the fabrication of electromagnetic shielding jacket and its application in daily life to combat against EM pollution. [ABSTRACT FROM AUTHOR]

Modulations of dielectric response and the investigation of magnetic property due to the percentage variation (3, 5 and 7 wt%) of chromium ion doping in 5 wt% yttrium doped-ZnO nanomaterials are considered in this report. The rods like Cr3+ and Y3+co-doped ZnO nanomaterials with polycrystalline single phase of wurtzite lattice structure are prepared by hydrothermal synthesis route. Frequency and temperature dependent dielectric response of all the co-doped ZnO nanomaterials were investigated in this report and the observation suggests that the dielectric permittivity of these co-doped ZnO nanomaterials can be modulated based on the site selectivity of the cationic dopants like Cr3+ or Y3+in between the lattice sites and the interstitial sites inside the host ZnO lattice structure. In addition, low temperature (10 K) magnetic ordering with 'S' shape hysteresis loop are observed. The hysteresis curve has been fitted and contribution of each magnetic phase (paramagnetic and ferromagnetic) has been extracted. This report is not only helpful to understand the modulation of dielectric response of ZnO like semiconducting materials depending on site selectivity of the cationic dopants inside the lattice structure of ZnO but also explore the underlying physics of DMS system consisting of multiple magnetic phases. This study shows that the semiconductors based dielectric materials are more effective for tailor made applications in various dielectric devices. [Display omitted] • Y3+ and Cr3+ ions co-doped ZnO was prepared by hydrothermal method. • Rod like structures were obtained for all the co-doped ZnO nanomaterials. • Defect states in co-doped ZnO were confirmed by PL spectra. • Co-doped ZnO shows significant magnetic response at low temperature. • Dielectric response has been observed in co-doped ZnO nanomaterials. [ABSTRACT FROM AUTHOR]

Detection of non-overlapping and overlapping communities are essentially the same problem. However, current algorithms focus either on finding overlapping or non-overlapping communities. We present a generalized framework that can identify both non-overlapping and overlapping communities, without any prior input about the network or its community distribution. To do so, we introduce a vertex-based metric, GenPerm, that quantifies by how much a vertex belongs to each of its constituent communities. Our community detection algorithm is based on maximizing the GenPerm over all the vertices in the network. We demonstrate, through experiments over synthetic and real-world networks, that GenPerm is more effective than other metrics in evaluating community structure. Further, we show that due to its vertex-centric property, GenPerm can be used to unfold several inferences beyond community detection, such as core-periphery analysis and message spreading. Our algorithm for maximizing GenPerm outperforms six state-of-the-art algorithms in accurately predicting the ground-truth labels. Finally, we discuss the problem of resolution limit in overlapping communities and demonstrate that maximizing GenPerm can mitigate this problem. [ABSTRACT FROM AUTHOR]

Experimental realization of magnetic field induced singlet to triplet transition is reported for NH 4 CuPO 4 ·H 2 O, a two spin cluster material with isotropic Heisenberg interaction. Experimental magnetization and specific heat data have been collected as a function of temperature and magnetic field. Experimental data have been analyzed in terms of Heisenberg dimer model. Two quantum complementary observables representing local and non-local properties of the spins are constructed using the experimental data and a clear evidence of singlet to triplet transition is observed through partial quantum information sharing when the magnetic field is swept through a particular value. Signature of this transition has also been captured when specific heat is measured as a function of magnetic field. Furthermore, using the experimental specific heat data, magnetic energy values are calculated and their variations are captured as a function of magnetic field and temperature. [ABSTRACT FROM AUTHOR]

Molecular dynamics (MD) is a powerful tool for calculating several thermo-physical properties of wide range of materials. In this study, the diffusivities (D) of two widely used long chain molecules MHA and ODT are calculated at various temperatures using MD simulations coupled with Einstein relationship. Four different kinds of forcefields COMPASS, UFF, CVFF and PCFF are employed in the MD simulation and the results are compared. Diffusivity values are evaluated in a humid environment in presence of water molecules. [ABSTRACT FROM AUTHOR]

It plays a vital role in scientometrics, bibliometrics, webometrics, and altmetrics, which require applying sophisticated algorithms to curate and derive useful insights from scholarly data. In scientific data mining, document classification is needed to categorize scientific papers into topics, keywords, etc. The past two decades have witnessed the rapid growth of scientific publications in all areas of research. [Extracted from the article]