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This paper aims to define a special case of neutrosophic matrices referred to as Fermatean neutrosophic matrices (FNMs). FNMs were introduced as generalization of Fermatean fuzzy matrices, intuitionistic fuzzy matrices, and Pythagorean neutrosophic matrices. In FNMs, some properties were discussed in connection with the well-known standard operations (⊕, ⊗, ∧ and ∨). In addition, the scalar multiplication (nA) and exponentiation ( 𝐴 𝑛 ) of a Fermatean neutrosophic matrix A were proposed, and their basic properties were investigated. Lastly, a new operation denoted by @ was defined on Fermatean neutrosophic matrices, and some of the properties of these matrices were examined.

Switched reluctance motors (SRM) are receiving extensive attention from the industry because of their simple construction, high reliability and efficiency. Antithetically, controlling SRM is challenging due to its nonlinearities and variable parameters such as speed, torque, flux, etc. In this study, a novel approach is used to control the speed and torque of SRM with various controllers. This methodology integrates model-in-loop (MIL) and hardware-in-loop (HIL) simulations to evaluate the efficiency of SRM in electric vehicles (Evs). To reduce the speed variations in the SRM, PID, intelligent, hybrid, and adaptive supervisory self-learning control approaches (ASSC) are used. The mathematical models of the aforementioned controllers were created in MATLAB/Simulink, and these control approaches are used to reduce speed, torque, and current fluctuations under various load and speed conditions. In this paper, both simulation and experimental work are used to investigate the various dynamic characteristics of the SRM in Evs. From the simulation findings, the proposed ASSC controller exhibits less overshoot (1.05%), settling time (0.02s) and risetime (0.01s) than PID, intelligent and hybrid control approaches. The proposed ASSC method combines numerical data and real-time rules knowledge with ANN to predict error responses in the SR motor. Also, it is significantly reducing the speed, torque, current and flux ripples of the SRM from low to high speed with different load conditions. Further, to verify the simulation results experimental work is conducted and similar results are measured under different load and speed conditions. From experimentation, efficiency maps are developed for PID, intelligent, hybrid, and ASSCs across the entire operating range. The maps show that the controller’s maximum efficiency is, respectively, 85%, 88%, 91%, and 95%. The supervisory controller is 10% more efficient than PID, intelligent, and hybrid controllers in terms of various dynamic characteristics of SRM. From the observations, both experimental and simulation results corroborated that the recommended ASSC improves the SRM efficiency.

Transient microwave reflectance (TMR) measurements are used to characterize the minority carrier lifetime and background carrier concentration of unintentionally doped (UID) Ga0.5As0.5Sb lattice matched to InP at room temperature. A p-i-n sample is measured, with UID GaAsSb as the intrinsic absorber. In addition to UID GaAsSb, we determine the minority carrier lifetime and doping concentration of a buried doped n+ GaAsSb layer. The measured minority carrier lifetimes are 20.5 ± 6.3 and 0.56 ± 0.23 µs for UID and doped GaAsSb, respectively, and comparable to that of lattice matched InGaAs. For both layers, the dominant recombination mechanisms are Shockley–Read–Hall (SRH) and Auger mechanisms. The measured background carrier concentrations are in good agreement with capacitance–voltage (C–V) measurements, with n0 = 1.81 ± 0.61 × 1015 cm−3 by TMR and n0 = 1.5 × 1015 cm−3 by C–V measurements for the UID layer and ND = 5.18 ± 1.42 × 1017 cm−3 by TMR and ND = 3–4 × 1017 cm−3 by C–V measurements for the doped layer. An absorber-only structure was also measured, and we report the SRH lifetime, radiative coefficient, and Auger coefficient for this sample.

The multiwavelength data from the Solar Dynamics Observatory is extensively used in studying the physics of the Sun and its atmosphere. In this study, we estimate the formation heights of low-corona and chromospheric channels of the Atmospheric Imaging Assembly (AIA) over the atmospheres of sunspot umbrae during the quiet condition period within 20 different active regions. The upward propagating slow magnetoacoustic waves of a 3 minute period, which are perpetually present in sunspots, are utilized for this purpose. Employing a cross-correlation technique, the most frequent time lag between different channel pairs is measured. By combining this information with the local sound speed obtained from the characteristic formation temperatures of individual channels, we estimate the respective formation heights. The median values of formation heights obtained across all active regions in our sample are 356, 368, 858, 1180, and 1470 km, respectively, for the AIA 1600, 1700, 304, 131, and 171 Å channels. The corresponding ranges in the formation heights are 247–453, 260–468, 575–1155, 709–1937, and 909–2585 km, respectively. These values are measured with respect to the Helioseismic Magnetic Imager continuum. We find the formation height of UV channels is quite stable (between 250 and 500 km) and displays only a marginal difference between the AIA 1600 and 1700 Å channels during quiet conditions. On the other hand, the formation height of coronal channels is quite variable.

We study the propagation properties of slow magnetoacoustic waves in a multithermal coronal loop using a 3D MHD model, for the first time. A bundle of 33 vertical cylinders, each of 100 km radius, randomly distributed over a circular region of radius 1 Mm, is considered to represent the coronal loop. The slow waves are driven by perturbing the vertical velocity ( v _z ) at the base of the loop. We apply forward modeling to the simulation results to generate synthetic images in the coronal channels of the Solar Dynamics Observatory/Atmospheric Imaging Assembly. Furthermore, we add appropriate data noise to enable direct comparison with the real observations. It is found that the synthetic images at the instrument resolution show noncospatial features in different temperature channels in agreement with previous observations. Time–distance maps are constructed from the synthetic data to study the propagation properties. The results indicate that the oscillations are only visible in specific channels, depending on the temperature range of the plasma existing within the loop. Additionally, the propagation speed of slow waves is also found to be sensitive to the available temperature range. Overall, we propose that the cross-field thermal properties of coronal structures can be inferred using a combination of numerical simulations and observations of slow magnetoacoustic waves.

Intro: The concurrent reopening of schools, increasing levels of hybrid immunity, and the emergence of the Omicron variant have affected the trajectory of the pandemic in India. We address related questions using the model Indian state of Andhra Pradesh (pop: 53 million). Methods: A compartmental model which describes the disease progression of COVID-19 with two dose vaccination is employed to understand the effect of vaccination, immunity due to infection and VOC Omicron. This is an age- stratified as well as a contact-structured model. The introduction of the Omicron variant is modelled. We studied disease dynamics in a background of seropositivity gained from an earlier wave of infection as well as an ongoing vaccination program, together called ''hybrid immunity''. We demonstrate the effect of school reopening as well as of the Omicron (BA.2) variant on cases across different age-groups. Findings: Reopening schools increases cases in children as compared to adults, although most such cases are asymptomatic or mild. The height of this peak reduced as the background infection-induced seropositivity was increased from 20% to 40%. At reported values of seropositivity of 64%, no discernable peak was seen. We find that in the absence of vaccination, even at such high levels of seroprevalence, the emergence of the Omicron variant would have resulted in a large rise in cases across all age bands. Discussion: In India, the decreasing prevalence of immunologically naïve individuals of all ages helped reduce the number of cases reported once schools were reopened. In addition, hybrid immunity, together with the lower intrinsic severity of disease associated with the Omicron variant, contributed to low reported COVID-19 hospitalizations and deaths. Conclusion: Mathematical modelling provides a powerful way of addressing central questions regarding the trajectory of the pandemic in India, clarifying the role of hybrid immunity.

Investigation of surface recombination is an important area for infrared detectors as the demand for smaller pixels increases. In this study, we use transient microwave reflectance to characterize the minority carrier lifetime of InAsSb nBn structures under three conditions: As-Grown, blanket Barrier-Etched, and SU-8 Passivated blanket barrier-etched. A qualitative comparison of these three samples shows that the minority carrier lifetime decreases for the Barrier-Etched sample compared to the As-Grown sample, indicating that the minority carrier lifetime is sensitive to changes in the sample surface, specifically the introduction of surface states. We compare these samples quantitatively using a polynomial fit (A−1 + Bn + Cn2). We find for the As-Grown sample A = 1.22 ± 0.45 µs, B = 2.5 ± 0.2 × 10−12 cm3/s, and C = 5.004 ± 4.996 × 10−31 cm6/s, for the Barrier-Etched sample A = 1.17 ± 0.40 µs, B = 9.9 ± 0.2 × 10−12 cm3/s, and C = 9.502 ± 9.498 × 10−30 cm6/s, and for the Passivated sample A = 1.34 ± 0.45 µs, B = 5.3 ± 0.5 × 10−12 cm3/s, and C = 5.500 ± 4.500 × 10−33 cm6/s.

This backstory features the perspectives of three group leaders of a Franco-Indian collaboration on the origin of life, involving efforts to engineer evolvable chemical systems. The researchers explain how they overcame the difficulties to bring empiricist and theorist cultures together and the importance of such synergy for the future of origin of life research.

Background doping polarity is a critical design parameter for the performance of many optoelectronic devices, including avalanche photodiodes. We have applied a technique by using capacitance–voltage (CV) measurements on double mesa structures with a p-i-n or n-i-p homojunction to determine the background polarity type of the unintentionally doped intrinsic region. Because CV measurements scale with the size of the mesa, they support design flexibility in producing variable-sized top and bottom mesa diameters. In this work, we grew, fabricated, and tested AlGaAsSb and AlInAsSb random alloy double mesa p-i-n structures and undertook CV measurements at 295, 150, and 77 K. It was found that the capacitance varied with the top mesa diameter for both material systems, and not the bottom mesa diameter, indicating that the unintentionally doped intrinsic region is n-type in nature.

Regular functions from infinite words to infinite words can be equivalently specified by MSO-transducers, streaming $\omega$-string transducers as well as deterministic two-way transducers with look-ahead. In their one-way restriction, the latter transducers define the class of rational functions. Even though regular functions are robustly characterised by several finite-state devices, even the subclass of rational functions may contain functions which are not computable (by a Turing machine with infinite input). This paper proposes a decision procedure for the following synthesis problem: given a regular function $f$ (equivalently specified by one of the aforementioned transducer model), is $f$ computable and if it is, synthesize a Turing machine computing it. For regular functions, we show that computability is equivalent to continuity, and therefore the problem boils down to deciding continuity. We establish a generic characterisation of continuity for functions preserving regular languages under inverse image (such as regular functions). We exploit this characterisation to show the decidability of continuity (and hence computability) of rational and regular functions. For rational functions, we show that this can be done in $\mathsf{NLogSpace}$ (it was already known to be in $\mathsf{PTime}$ by Prieur). In a similar fashion, we also effectively characterise uniform continuity of regular functions, and relate it to the notion of uniform computability, which offers stronger efficiency guarantees.

The current exploration work focuses on the fabrication of aluminum 7075 matrix composites built up with different weight levels of titanium carbide particles by a traditional stir casting process. In particular, the combination of high hardness and flexible modulus, low density, great wettability, and low synthetic reactivity with aluminum melt makes TiC particle an attractive material. From 0% to 6 wt.% of reinforcement is introduced in steps of 3 wt.%. Aluminum matrix composites are studied in depth to learn more about their microstructures and mechanical properties. TiC particles were uniformly dispersed in the aluminum lattice, as shown by scanning electron micrographs of the material’s microstructure. As the weight of the TiC particles in the aluminum lattice increases, so does the density of the composites. The X-ray diffraction technique has also been used to detect the phase of TiC particles. As the amount of TiC particles in the aluminum matrix increases, the material’s mechanical properties, such as ultimate tensile strength and hardness, increase at the expense of ductility. The preorganized composites have also undergone fractography testing.

The impact of wear factors on composite materials is examined in this article. Stir casting was used to produce AA7075 alloys with varied nano-zirconium boride weight ratios. The dry sliding wear test was done utilizing pin-on-disc test equipment. The L27 orthogonal array was built by Taguchi’s experiments for optimization. We calculated the proportion of responses that could be attributed to the input parameters using SNR and ANOVA. The rate of wear and the frictional coefficient raised with the highest loading level. Load concentration had an extreme impact on wear rate, coefficient of friction, sliding distance, and speed. Nano-zirconium boride particles placed in the matrix alloy prohibited any material loss. Zirconium boride nanoparticles were applied to AA7075 to increase its wear resistance.

In this work, an attempt was made to machine the AZ91/5B4C/5Gr hybrid composites in a castor oil electric discharge medium with an objective of attaining green environment. The hybrid composites were produced using stir casting technique in a protective environment. Experiments were conducted by varying dielectric fluid (castor oil and hydrocarbon oil), tool materials (copper, graphite, and brass), polarity, current, pulse-on time, and gap distance in Al2O3 mixed dielectric medium. L36 Taguchi approach was adopted for the design of experiments, and machining performance was accessed in terms of material removal rate (MRR), tool wear rate (TWR), and surface roughness (Ra). Because of castor oil’s high thermal conductivity, high kinematic viscosity, and lower dielectric strength, the specimen exhibits 5% higher MRR than EDM oil. When the electrodes were connected to the negative polarity, the Ra was 1.72 μm and 3.66 μm at positive polarity; however, at negative polarity, the TWR was higher than the MRR. The high density and specific heat of castor oil facilitate flushing and uniform heat distribution; as a result, the composite had a Ra of 2.52 μm compared to 2.86 μm when machined with conventional EDM oil. Surface topography showed the specimen machined with hydrocarbon dielectric medium proffers black spots, which were eliminated in castor dielectric medium. Best parametric combination was selected by the Relative Index Method optimization technique.

Today’s modern, dynamic world would be impossible to imagine without the concept of composite material advancement. Various studies are being conducted in this area in order to reach the desired level. In terms of compatibility, natural fibre reinforced polymer-based composites and synthetic fibre composites are very similar. Because they are lightweight, nontoxic, and nonabrasive, they are very popular with consumers. They are also readily available and affordable. Composite materials made from natural fibre have superior mechanical properties compared to those made from synthetic fibre. As part of this research, an epoxy-based composite with bamboo and sisal fibre reinforcement is examined. Reinforced with epoxy resin, bamboo fibre and sisal fibre are used to make composite materials. The effect of adding bamboo fibre and sisal fibre in various weight percentages on the mechanical behaviour of composites is investigated.

Aluminium (Al) thin films (thickness ranging between 500 and 600 nm) were deposited on stainless-steel substrates at varying radio-frequency (RF) power by magnetron sputtering at a constant substrate temperature of 90°C. Characterisations were undertaken by field emission scanning electron microscopy (FESEM), optical surface profilometry (OSP), atomic force microscopy (AFM), X-ray diffraction (XRD), selected Fourier-transform infrared spectroscopy (FTIR), nanoindentation, and micro-scratch tests. At high RF powers (300–350 W), there was the formation of less porous, dense, and continuous Al thin films with better resistance to scratch failure. The high roughness on films deposited at 200 and 250 W was due to high porosity and oxides observed on the FESEM micrographs.

The present study focuses on the evaluation of the effect of engine parameters on the characteristics of a GDI engine by CFD analysis. The analysis was carried out at three engine speeds (2000, 3000, and 4000 rev/min), at three compression ratios (10, 11, and 12) and at three fuel injection pressures (200, 300, and 400 bar). The overall equivalence ratio of the in-cylinder mixture was maintained at 0.75 in all the above cases. Finally, it is observed that, the turbulent kinetic energy and tumble ratio were more sensitive to the engine speed than to other parameters. The fuel injection pressure was found to play a vital role in obtaining combustible mixture near the spark plug at the time of spark. In addition, a low heat release rate occurred at the engine speed of 4000 rev/min compression ratio of 10 and fuel injection pressure of 200 bar. Keywords: GDI engine, Engine parameters, CFD, Performance characteristics

Abstract We discuss the complete sets of the off-shell nilpotent (i.e. $$s^2_{(a)b} = 0$$ s ( a ) b 2 = 0 ) and absolutely anticommuting (i.e. $$s_b s_{ab} + s_{ab} s_b = 0$$ s b s a b + s a b s b = 0 ) Becchi–Rouet–Stora–Tyutin (BRST) $$(s_b)$$ ( s b ) and anti-BRST $$(s_{ab})$$ ( s a b ) symmetries for the $$(3+1)$$ ( 3 + 1 ) -dimensional (4D) gauge-invariant massive 2-form theory within the framework of an augmented superfield approach to the BRST formalism. In this formalism, we obtain the coupled (but equivalent) Lagrangian densities which respect both BRST and anti-BRST symmetries on the constrained hypersurface defined by the Curci–Ferrari type conditions. The absolute anticommutativity property of the (anti-) BRST transformations (and corresponding generators) is ensured by the existence of the Curci–Ferrari type conditions which emerge very naturally in this formalism. Furthermore, the gauge-invariant restriction plays a decisive role in deriving the proper (anti-) BRST transformations for the Stückelberg-like vector field.

The effect of ocean acidification on growth and calcification of the marine algae Emiliania huxleyi was investigated in a series of mesocosm experiments where enclosed water volumes that comprised a natural plankton community were exposed to different carbon dioxide (CO2) concentrations. Calcification rates observed during those experiments were found to be highly variable, even among replicate mesocosms that were subject to similar CO2 perturbations. Here, data from an ocean acidification mesocosm experiment are reanalysed with an optimality-based dynamical plankton model. According to our model approach, cellular calcite formation is sensitive to variations in CO2 at the organism level. We investigate the temporal changes and variability in observations, with a focus on resolving observed differences in total alkalinity and particulate inorganic carbon (PIC). We explore how much of the variability in the data can be explained by variations of the initial conditions and by the level of CO2 perturbation. Nine mesocosms of one experiment were sorted into three groups of high, medium, and low calcification rates and analysed separately. The spread of the three optimised ensemble model solutions captures most of the observed variability. Our results show that small variations in initial abundance of coccolithophores and the prevailing physiological acclimation states generate differences in calcification that are larger than those induced by ocean acidification. Accordingly, large deviations between optimal mass flux estimates of carbon and of nitrogen are identified even between mesocosms that were subject to similar ocean acidification conditions. With our model-based data analysis we document how an ocean acidification response signal in calcification can be disentangled from the observed variability in PIC.

To describe the underlying processes involved in oceanic plankton dynamics is crucial for the determination of energy and mass flux through an ecosystem and for the estimation of biogeochemical element cycling. Many planktonic ecosystem models were developed to resolve major processes so that flux estimates can be derived from numerical simulations. These results depend on the type and number of parameterizations incorporated as model equations. Furthermore, the values assigned to respective parameters specify a model's solution. Representative model results are those that can explain data; therefore, data assimilation methods are utilized to yield optimal estimates of parameter values while fitting model results to match data. Central difficulties are (1) planktonic ecosystem models are imperfect and (2) data are often too sparse to constrain all model parameters. In this review we explore how problems in parameter identification are approached in marine planktonic ecosystem modelling. We provide background information about model uncertainties and estimation methods, and how these are considered for assessing misfits between observations and model results. We explain differences in evaluating uncertainties in parameter estimation, thereby also discussing issues of parameter identifiability. Aspects of model complexity are addressed and we describe how results from cross-validation studies provide much insight in this respect. Moreover, approaches are discussed that consider time- and space-dependent parameter values. We further discuss the use of dynamical/statistical emulator approaches, and we elucidate issues of parameter identification in global biogeochemical models. Our review discloses many facets of parameter identification, as we found many commonalities between the objectives of different approaches, but scientific insight differed between studies. To learn more from results of planktonic ecosystem models we recommend finding a good balance in the level of sophistication between mechanistic modelling and statistical data assimilation treatment for parameter estimation.

The rapid damping of slow magnetoacoustic waves in the solar corona has been extensively studied in previous years. Most studies suggest that thermal conduction is a dominant contributor to this damping, albeit with a few exceptions. Employing extreme-ultraviolet (EUV) imaging data from SDO/AIA, we measure the damping lengths of propagating slow magnetoacoustic waves observed in several fan-like loop structures using two independent methods. The dependence of the damping length on temperature has been studied for the first time. The results do not indicate any apparent decrease in damping length with temperature, which is in contrast to the existing viewpoint. Comparing with the corresponding theoretical values calculated from damping due to thermal conduction, it is inferred that thermal conduction is suppressed in hotter loops. An alternative interpretation that suggests thermal conduction is not the dominant damping mechanism, even for short period waves in warm active region loops, is also presented.

Objective: The quantitative measurement and antecedents of doctoral well-being have not been sufficiently explored in the extant literature, creating a significant gap based on alarming statistics of high attrition rates and psychological distress among PhD scholars. Therefore, based on the theory of conservation of resources, our study examines the role of personal resources such as harmonious passion (HP), Grit, and psychological capital (PsyCap) in enhancing PhD students' well-being. Additionally, it proposes a novel conceptualisation of doctoral well-being, combining research engagement (eudaimonic well-being) and satisfaction (hedonic well-being). Method: We use structural equation modelling to analyse data collected from 239 doctoral students in India's higher educational institutions (HEI). Results: The results show that HP and Grit are significantly and positively associated with doctoral students' well-being while PsyCap partially mediates the relationship of HP and Grit with well-being. Conclusions: HP and Grit are personal resources which can enhance doctoral students' well-being. PsyCap assists in this process through resource gain whereby students with higher personal resources could gather further resources, leading to hedonic and eudaimonic well-being. The study also highlights practical implications for supervisors and management of HEIs.

We report photophysical properties of a nanocomposite consisting of perovskite quantum cuboids (QCs) formed by CsPbBr3 and a wide temperature range nematic liquid crystal. Contrary to observations made with conventional II-VI quantum dots dispersed in a liquid crystal, the used QCs form, under the influence of the nematic orientation, linear assemblies over macroscopic length scales evidenced by polarizing optical microscopy. Interestingly, the linear assembly is actually caused by such an anisotropic arrangement at the nm scale, as seen in TEM images. Thin films of the nanocomposite exhibiting this unique and fascinating character exhibit absorption and emission features, which are quite appealing. These include retention of the sharp bandwidth of emission characteristic of the native QCs and establishment of dual anisotropies, arising from the values being different along the director as well in the two directions orthogonal to it. We also present data on voltage-driven switching between one of the anisotropic limits.

We report on a dual-band [mid/long-wave infrared (MWIR and LWIR)] InAs/GaSb strained layer superlattice detector with a pBp architecture. Fifty percent cutoff wavelengths of 5 and 9 μm were obtained with diffusion-limited behavior for midwave IR absorber. At 77 K, the peak D* values were equal to 5 × 1011 Jones (Vb = +0.1 V, λ = 5 μm) and 2.6 × 1010 Jones (Vb = -0.4 V, λ = 9 μm). The corresponding values of responsivity and quantum efficiency were 1.6 A/W and 39% (MWIR) and 1.3 A/W and 17% (LWIR).

We derive the complete set of off-shell nilpotent and absolutely anticommuting Becchi-Rouet-Stora-Tyutin (BRST), anti-BRST, and (anti-)co-BRST symmetry transformations for all the fields of the modified version of two (1+1)-dimensional (2D) Proca theory by exploiting the “augmented” superfield formalism where the (dual-)horizontality conditions and (dual-)gauge invariant restrictions are exploited together. We capture the (anti-)BRST and (anti-)co-BRST invariance of the Lagrangian density in the language of superfield approach. We also express the nilpotency and absolute anticommutativity of the (anti-)BRST and (anti-)co-BRST charges within the framework of augmented superfield formalism. This exercise leads to some novel observations which have, hitherto, not been pointed out in the literature within the framework of superfield approach to BRST formalism. For the sake of completeness, we also mention, very briefly, a unique bosonic symmetry, the ghost-scale symmetry, and discrete symmetries of the theory and show that the algebra of conserved charges provides a physical realization of the Hodge algebra (satisfied by the de Rham cohomological operators of differential geometry).

Objectives: Acinetobacter spp. has emerged as a threat to the healthcare workers throughout the globe, owing to its property of multidrug resistance. The aim of the present study was to evaluate the antimicrobial resistance patterns of Acinetobacter spp. among indoor and out patients in our hospital and compare the resistance patterns in India and abroad. Materials and Methods: In this retrospective study, which was carried out over a period of one year, a total of 5593 clinical specimens of pus and purulent fluids were examined and antimicrobial resistance pattern for Acinetobacter spp. using Modified Stoke’s were evaluated. Also a comparison was done with the other similar studies. Statistical Analysis: Using the proportions of sensitive and resistant, the statistical analysis was done. The total, mean and percentage were calculated by using SPSS. Results: A high level of antimicrobial multidrug-resistance was found in almost all the clinical isolate. Our study was also found to be concordant with the results of other studies. Conclusion: There is an emerging need for identification of the genes and mechanisms for multidrug resistance among Acinetobacter spp.