Shape Of Profile Research Articles

Geometric morphometrics casts light on phylogenetic relevance of cephalopod beak morphological.

The feeding organ of cephalopod species, the beak, can be used to reveal important ecological information. In this study, geometric morphometric approaches were employed to investigate the phylogenetic relevance and classification effect of beak lateral profile shape. The two-dimensional beak morphologies of 1164 pairs of 24 species from 13 genera and five families were constructed, and their evolutionary relationships and taxonomic status were confirmed using geometric morphometrics and molecular biology approaches. We also assessed the phylogenetic signals of beak shape. The analysis results show shape variation in the beak mainly in the rostrum, hood, and lateral wall. The overall shape parameters (all PCs) of the upper and lower beak are more useful for species identification. The shapes of the upper and lower beak show a strong phylogenetic signal, and the phenogram based on the beak shape basically reflected the families' taxonomic positions. We also hypothesized that the shape variation in the beaks of cephalopods may be ascribed to genetic and environmental differences. In summary, beaks are a reliable material for the classification of cephalopod species. Geometric morphometric approaches are a powerful tool to reveal the identification, phylogenetic relevance and phenotypic diversity of beak shape in cephalopods.

Characterization of Physicochemical Properties of Annealed Corn Flour and Starch: A Verification of Meta‐Analysis

AbstractThis study examines the effects of annealing process (temperature 50 °C, moisture content of 80%, for 20 h) on physicochemical characteristics (proximate composition, content of resistant starch (RS) and amylose, degree of starch digestibility, shape and size of starch granules, crystallinity, and starch gelatinization profile) of corn flour and corn starch. Two stages of experiment are as follows: 1) verifying the results of the meta‐analysis of corn starch and flour modification by annealing method and 2) analyzing their physicochemical properties. As a result, annealing significantly improves RS content in both groups, reaching 14.18% in annealed corn flour (AF) (compared to 3.27% in native corn flour (NF)) and 21.87% in annealed corn starch (AS) (compared to 3.82% in native corn starch (NS)). The present work also confirms that the treatment unaltered birefringence properties of all samples. Moreover, pasting properties of corn starch and flour demonstrate remarkable changes. The peak viscosity of AS and NS is higher than AF and NF. In addition, gelatinization seems to occur at similar temperature, but needs extra time for starting gelatinization. XRD analysis reveals A‐type crystalline for all samples, while FTIR analysis evidenced that annealing process alters the regions of amorphous and crystalline.

Soliton solutions to a nonlinear wave equation via modern methods

AbstractIn this pioneering study, we have systematically derived traveling wave solutions for the highly intricate Zoomeron equation, employing well-established mathematical frameworks, notably the modified (G′/G)-expansion technique. Twenty distinct mathematical solutions have been revealed, each distinguished by distinguishable characteristics in the domains of hyperbolic, trigonometric, and irrational expressions. Furthermore, we have used the formidable computational capabilities of Maple software to construct depictions of these solutions, both in two-dimensional and three-dimensional visualizations. The visual representations vividly capture the essence of our findings, showcasing a diverse spectrum of wave profiles, including the kink-type shape, soliton solutions, bell-shaped waveforms, and periodic traveling wave profiles, all of which are clarified with careful precision.

O-GlcNAcylation regulates long-chain fatty acid metabolism by inhibiting ACOX1 ubiquitination-dependent degradation

BackgroundCold as a common environmental stress, causes increased heat production, accelerated metabolism and even affects its production performance. How to improve the adaptability of the animal organism to cold has been an urgent problem. As a key hub of lipid metabolism, the liver can regulate lipid metabolism to maintain energy balance, and O-GlcNAcylation is a kind of important PTMs, which participates in a variety of signaling and mechanism regulation, and at the same time, is very sensitive to changes in stress and nutritional levels, and is the body's “stress receptors” and “nutrient receptors”. Therefore, the aim of this experiment was to investigate the effect of cold-induced O-GlcNAcylation on hepatic lipid metabolism, and to explore the potential connection between O-GlcNAcylation and hepatic lipid metabolism. MethodsTo investigate the loss of O-linked N-acetylglucosamine (O-GlcNAc) transferase (OGT) and the precise impacts of additional cold-induced circumstances on liver mass, shape, and metabolic profile, C57 mice were used as an animal model. Using the protein interactions approach, the mechanism of O-GlcNAcylation, as well as the degradation pathway of acyl-Coenzyme A oxidase 1 (ACOX1), were clarified. Additional in vitro analyses of oleic acid (OA) and OGT inhibitor tetraoxan (Alloxan) (Sigma, 2244-11-3) on lipid breakdown in AML-12 cells. ResultsIn C57BL/6 mice, deletion of O-GlcNAcylation disrupted lipid metabolism, caused hepatic edema and fibrosis, and altered mitochondrial apoptosis. This group of modifications was made worse by cold induction. The accumulation of medium- and long-chain fatty acids is a hallmark of lipolysis, which is accelerated by the deletion of O-GlcNAcylation, whereas lipid synthesis is slowed down. The association between ACOX1 and OGT at the K48 gene precludes ubiquitinated degradation.

Automatic extraction of multiple morphological parameters of lunar impact craters

AbstractImpact craters are geomorphological features widely distributed on the lunar surface. Their morphological parameters are crucial for studying the reasons for their formation, the thickness of the lunar regolith at the impact site and the age of the impact crater. However, current research on the extraction of multiple morphological parameters from a large number of impact craters within extensive geographical regions faces several challenges, including issues related to coordinate offsets in heterogeneous data, insufficient interpretation of impact crater profile morphology and incomplete extraction of morphological parameters. To address the aforementioned challenges, this paper proposes an automatic extraction method of morphological parameters based on the digital elevation model (DEM) and impact crater database. It involves the correction of heterogeneous data coordinate offset, simulation of impact crater profile morphology and various impact crater morphological parameter automatic extraction. And the method is designed to handle large numbers of impact craters in a wide range of areas. This makes it particularly useful for studies involving regional‐scale impact crater analysis. Experiments were carried out in geological units of different ages and we analysed the accuracy of this method. The analysis results show that: first, the proposed method has a relatively effective impact crater centre position offset correction. Second, the impact crater profile shape fitting result is relatively accurate. The R‐squared value (R2) is distributed from 0.97 to 1, and the mean absolute percentage error (MAPE) is between 0.032% and 0.568%, which reflects high goodness of fit. Finally, the eight morphological parameters automatically extracted using this method, such as depth, depth–diameter ratio, and internal and external slope, are basically consistent with those extracted manually. By comparing the proposed method with a similar approach, the results demonstrate that it is effective and can provide data support for relevant lunar surface research.

Neutron radiography with simultaneous deformation measurements demand rethinking the modelling of imbibition in cement paste

During capillary imbibition, there are changes in the pore structure that reduce the water ingress rate, leading to anomalous behaviour. However, the relation of those deformations with the C-S-H content is still unclear. We performed simultaneous measurements of external deformations and water ingress through neutron radiography. Cement pastes of water/cement of 0.4 and 0.6, using both Portland and white cement were tested after 1 year curing. Porosity and calcium silicate hydrate (C-S-H) content of the pastes were determined. Strain gauges were attached perpendicular and parallel to the water flow. Results indicate that the degree of internal restriction of the mix influences the shape of the water profile and that C-S-H deformations affect internal changes more than external. Water ingress visualisation indicated the lack of a sharp front during imbibition and the saturation degree variation at the position of the strain gauges. We propose a model to address the dynamic porosity.

Sustainable Development Strategies in Power Systems: Day-Ahead Stochastic Scheduling with Multi-Sources and Customer Directrix Load Demand Response

Increasing the installed capacity of renewable energy sources (RESs) in the power system is significant for advancing sustainable development. As the proportion of RESs rapidly increases in power systems, the inherent stochasticity and variability of renewable energies significantly reduce the regulatory capacity of generation resources. To compensate for the lack of power system flexibility, it is necessary to coordinate the participation of load-side resources in demand response (DR). Therefore, this paper proposes a solution to the diminished flexibility of power systems. It introduces a day-ahead stochastic scheduling model for an integrated thermal-hydro-wind-solar system. This model relies on customer directrix load (CDL) to efficiently absorb RES output. CDL represents an ideal load profile shape. Firstly, the stochastic scenario sets of RES output were modeled using Monte Carlo simulations, and the complementary characteristics between wind and solar output are considered using Copula theory. Then, CDL is introduced into day-ahead scheduling model, which considers relevant demand-side responsive load constraints. Secondly, customer-side DR effectiveness model is proposed to obtain the shaping load profile after DR, based on quantitative customer response effectiveness evaluation metrics. Lastly, system-side stochastic scheduling model of high-proportion RES power system is proposed based on the shaping load profile. Case studies were conducted on a modified IEEE-6 bus system. These studies show that the model effectively addresses the uncertainty of RES. It improves the power system’s regulation capability. Additionally, it promotes the absorption of RES.

Revised estimates of NO2 reductions during the COVID-19 lockdowns using updated TROPOMI NO2 retrievals and model simulations

The TROPOspheric Monitoring Instrument (TROPOMI) observed unprecedented declines in NO2 vertical column densities (VCD) over the world's most densely populated cities during the 2020 COVID-19 lockdowns. These favorable changes in NO2 air quality were correlated with sharp reductions in traffic volume and economic activity during the lockdowns. In this comprehensive global study, we provide revised estimates of the declines in anthropogenic emissions for 36 megacities using a novel methodology for disentangling the anthropogenic emissions from the meteorological transport and natural variability. We further quantify the uncertainty associated with changes in the a priori profile shape information during the lockdowns due to reduced emissions. Satellite NO2 retrieval techniques calculate an air mass factor that requires a priori NO2 profile shape information representative of the local atmosphere. This information, which is typically obtained from a chemical transport model (CTM), was not available for the early studies. This study also accounts for the satellite sampling errors resulting from the selective sampling of non-cloudy scenes during the study period. For our analysis, we used CTM simulations that were generated with and without COVID-impacted emissions. We perform retrievals of tropospheric NO2 columns with the NASA NO2 algorithm, and then use observed and simulated data to disentangle the meteorological transport from the contribution due anthropogenic emissions. We found that the meteorological transport was most significant source of variability ranging between −35% and 22% of the change total tropospheric VCD. We also find that not accounting for changes in the a priori NO2 profile shape information during the lockdowns resulted in systematic retrieval errors that were up to 12% of the estimated decline, and the elimination of cloud contaminated scenes resulted in sampling errors that in general ranged between varied ±15%.

Triaxial Schwarzschild models of NGC 708: a 10-billion solar mass black hole in a low-dispersion galaxy with a Kroupa IMF

ABSTRACT We report the discovery of a (1.0 ± 0.28) × 1010 M⊙ supermassive black hole (BH) at the centre of NGC 708, the Brightest Cluster Galaxy of Abell 262. Such high BH masses are very rare and allow to investigate BH–host galaxy scaling relations at the high mass end, which in turn provide hints about the (co)evolution of such systems. NGC 708 is found to be an outlier in all the canonical scaling relations except for those linking the BH mass to the core properties. The galaxy mass-to-light ratio points to a Kroupa IMF rather than Salpeter, with this finding confirmed using photometry in two different bands. We perform this analysis using our novel triaxial Schwarzschild code to integrate orbits in a five-dimensional space, using a semiparametric deprojected light density to build the potential and non-parametric line-of-sight velocity distributions (LOSVDs) derived from long-slit spectra recently acquired at Large Binocular Telescope (LBT) to exploit the full information in the kinematic. We find that the galaxy geometry changes as a function of the radius going from prolate, nearly spherical in the central regions to triaxial at large radii, highlighting the need to go beyond constant shape profiles. Our analysis is only the second of its kind and will systematically be used in the future to hunt supermassive BH in giant ellipticals.

Acetazolamide Challenge Changes Outer Retina Bioenergy-Linked and Anatomical OCT Biomarkers Depending on Mouse Strain.

The purpose of this study was to test the hypothesis that optical coherence tomography (OCT) bioenergy-linked and anatomical biomarkers are responsive to an acetazolamide (ACZ) provocation. C57BL/6J mice (B6J, a strain with relatively inefficient mitochondria) and 129S6/ev mice (S6, a strain with relatively efficient mitochondria) were given a single IP injection of ACZ (carbonic anhydrase inhibitor) or vehicle. In each mouse, the Mitochondrial Configuration within Photoreceptors based on the profile shape Aspect Ratio (MCP/AR) index was determined from the hyper-reflective band immediately posterior to the external limiting membrane (ELM). In addition, we tested for ACZ-induced acidification by measuring contraction of the external limiting membrane-retinal pigment epithelium (ELM-RPE) thickness; the hyporeflective band (HB) signal intensity at the photoreceptor tips was also examined. Finally, the nuclear layer thickness was measured. In response to ACZ, MCP/AR was greater-than-vehicle in B6J mice and lower-than-vehicle in S6 mice. ACZ-treated B6J and S6 mice both showed ELM-RPE contraction compared to vehicle-treated mice, consistent with dehydration in response to subretinal space acidification. The HB intensity at the photoreceptor tips and the outer nuclear layer thickness (B6J and S6), as well as the inner nuclear layer thickness of B6J mice, were all lower than vehicle following ACZ. Photoreceptor respiratory efficacy can be evaluated in vivo based on distinct rod mitochondria responses to subretinal space acidification measured with OCT biomarkers and an ACZ challenge, supporting and extending our previous findings measured with light-dark conditions.

Characteristics of turbulent flow around bridge abutments in the presence of vegetation in channel bed under ice-covered flow conditions

During winter, ice cover frequently forms on the water surface of rivers with vegetated channel beds in cold regions. The investigation of the impacts of both ice cover and channel bed vegetation on flow structures around bridge abutments is essential for engineers to gain a comprehensive understanding of the complex interactions occurring in such a situation. In the present study, the flow structure around a rectangular bridge abutment in the presence of vegetation under ice-covered conditions has been studied. Considering different vegetation densities by arranging vegetation elements in square and staggered configurations, this study incorporates the influence of ice covers with different roughness, namely smooth and rough ice cover. Key turbulence parameters, including turbulence intensity, Reynolds shear stress (RSS), and turbulent kinetic energy (TKE), are also examined based on laboratory experiments. Results show that the shape of velocity profiles for flow over a vegetated channel bed changes from an S-shaped curve under an open flow condition to a convex shape under ice-covered conditions. The effects of an ice cover and vegetation on the flow around the bridge abutment create unpredictable turbulence intensity patterns. Under a rough-covered flow condition, there appears a larger area with negative Reynolds shear stress (RSS) downstream of the abutment. Turbulent kinetic energy (TKE) under ice-covered conditions has substantially lower magnitudes than in open flow conditions.

A.C.I.D – an improved LSD technique for accurate line profile retrieval

ABSTRACT Stellar activity and planetary effects induce radial velocity (RV) offsets and cause temporal distortions in the shape of the stellar line profile. Hence, accurately probing the stellar line profile offers a wealth of information on both the star itself and any orbiting planets. Typically, cross-correlation functions (CCFs) are used as a proxy for the stellar line profile. The shape of CCFs, however, can be distorted by line blending and aliasing limiting the stellar and planetary physics that can be probed from them. Least-squares deconvolution (LSD) offers an alternative that directly fits the mean line profile of the spectrum to produce a high-precision profile. In this paper, we introduce our novel method ACID (Accurate Continuum fItting and Deconvolution) that builds on LSD techniques by simultaneously fitting the spectral continuum and line profile as well as performing LSD in effective optical depth. Tests on model data revealed ACID can accurately identify and correct the spectral continuum to retrieve an injected line profile. ACID was also applied to archival High Accuracy Radial-velocity Planet Searcher (HARPS) data obtained during the transit of HD189733b. The application of the Reloaded Rossiter–McLaughlin technique to both ACID profiles and HARPS CCFs shows ACID residual profiles improved the out-of-line root mean square (RMS) by over 5 per cent compared to CCFs. Furthermore, ACID profiles are shown to exhibit a Voigt profile shape that better describes the expected profile shape of the stellar line profile. This improved representation shows that ACID better preserves the stellar and planetary physics encoded in the stellar line profile shape for slow rotating stars.

Cosmological and idealized simulations of dark matter haloes with velocity-dependent, rare and frequent self-interactions

ABSTRACT Dark matter self-interactions may have the capability to solve or at least mitigate small-scale problems of the cosmological standard model, Lambda cold dark matter. There are a variety of self-interacting dark matter models that lead to distinguishable astrophysical predictions and hence varying success in explaining observations. Studies of dark matter (DM) density cores on various mass scales suggest a velocity-dependent scattering cross-section. In this work, we investigate how a velocity dependence alters the evolution of the DM distribution for frequent DM scatterings and compare to the velocity-independent case. We demonstrate that these cases are qualitatively different using a test problem. Moreover, we study the evolution of the density profile of idealized DM haloes and find that a velocity dependence can lead to larger core sizes and different time-scales of core formation and core collapse. In cosmological simulations, we investigate the effect of velocity-dependent self-interaction on haloes and satellites in the mass range of ≈1011–$10^{14} \, \mathrm{M_\odot }$. We study the abundance of satellites, density, and shape profiles and try to infer qualitative differences between velocity-dependent and velocity-independent scatterings as well as between frequent and rare self-interactions. We find that a strongly velocity-dependent cross-section can significantly amplify the diversity of rotation curves, independent of the angular dependence of the differential cross-section. We further find that the abundance of satellites in general depends on both the velocity dependence and the scattering angle, although the latter is less important for strongly velocity-dependent cross-sections.

Mechanism and Prevention of Main Roadway Roof Shock in Strong-Bump Coal Seam with Asymmetric Goaf

In response to the increasingly severe situation of main roadway shock in coal seams, with a focus on the strong-bump coal seam in main roadways under an asymmetric goaf in a certain mine, theoretical analysis, numerical simulation, and engineering practices were employed. This study investigated factors influencing main roadway roof shock damage, changes in roof stress, and characteristics of overlying strata movement. This research unveiled the mechanism and prevention of roof shock in main roadways of strong-bump coal seams in an asymmetric goaf. The research results indicate that the influencing factors of main roadway roof shock damage can be divided into two categories: “strata-support” structure strength and surrounding rock stress. For the determination of the “strata-support” structure, in the case of strong bumps in coal seam roadways influenced by the asymmetric goaf, the key factors contributing to shock damage are the side abutment pressure on the coal pillar in the goaf and the activity level of the roof strata. The distribution of roof stress in the main roadway undergoes continuous changes as district faces are sequentially mined. When the goaf area on the west side gradually increases towards the south, the roof stress in the main roadway consistently rises, and the stress increment follows a pattern of initial increase followed by a decrease. The strata structure of the main roadway roof gradually transforms from an “asymmetric T” shape to a “symmetric T” shape in the transverse profile, and with the evolution of the roof rock layer structure, the mutual feedback effect of strata activity on both sides of the roadway gradually strengthens. Affected by the asymmetric goaf, the main roadway in the district undergoes three different stages: one side of subcritical mining influence → both sides of subcritical mining influence → one side of subcritical mining and one side of critical mining influence. In addition, comprehensively considering the impact of various factors in different stages, the theoretical criteria for roof shock failure in the main roadway are determined. The formulation of an optimized position for the main roadway and a scheme for depressurization through deep-hole blasting in the roof reduce the stress level in the surrounding rock of the main roadway, effectively preventing the occurrence of roof shock in the asymmetric goaf of the coal seam main roadway.

Estimating the parameters of competitive Langmuir adsorption isotherms from measured responses to rectangular pulse injections exploiting equilibrium theory

Knowledge of adsorption isotherms is essential for the design and optimization of chromatographic separation processes. Since the experimental determination of these thermodynamic functions is a complicated and time consuming task, there is a need to develop methods which are fast and easy to apply. An attractive group of methods is based on neglecting in the analysis of measured dynamic elution profiles all kinetic effects. These methods assume the validity of an isotherm model equation and exploit the possibility to solve analytically the column mass balance equations of the equilibrium model. If just the dispersive part of an elution profile is, the method is known as “elution by characteristic point” (ECP). The ECP method has been applied successfully to analyse column effluent profiles of single component dissolved in a mobile phase. This work extends the ECP method to analyse just the shapes of elution profiles recorded after injecting samples that contain two key components to be separated. The extended ECP method requires recording only one overloaded elution profile for the two-component mixture and offers a fast and efficient way to estimate isotherm model parameters. The method is in particular attractive if there is limited access to the pure components, as for example in cases of enantiomers. The underlying theory is presented and applied for the case that the adsorption equilibria can be described satisfactorily by the classical competitive Langmuir model. Core of the theory are the available analytical equations describing the outlet concentration profiles of the two solutes for the equilibrium controlled case the. Considering a case study, it is shown that the extended ECP method can be applied successfully for columns characterized by 2500 or more theoretical plates. However, the method can be useful also for columns with lower efficiency. It provides then a rough estimation regarding the isotherm courses.

Deconvolution of spatially averaged shock wave forms

Noncontact optical methods (e.g., shadowgraphy, schlieren, and interferometry) allow visualization of propagating shock waves, avoid sensor-field interaction, and retain the potential for very high bandwidth. The heterodyne Mach-Zehnder interferometer produces quantifiable noncontact samples of the accumulated phase shifts induced by a shock wave, as viewed through its beam projection. This instrument is commercially available as a Laser Doppler Vibrometer (LDV). For shocked wave fields in air obeying spherical symmetry, point values for density and overpressure can be inferred. An important shortcoming for inference quality is the finite spatial dependence of the probe beam cross section, the profile shape itself serving to limit both the spatial resolution and the measurement bandwidth. We propose to model both of these effects of spatial averaging by constructing a model waveform and a model beam profile, convolving them, and comparing the result to synthesized LDV output. Mismatch between the convolved result and spatially averaged measurement can be quantified by a cost function, which is minimized via gradient descent.

Modeling the scattering polarization in the solar Ca I 4227Å line with angle-dependent PRD effects and bulk velocities

Context. Modeling the scattering polarization signals of strong chromospheric lines requires solving the radiative transfer problem for polarized radiation, out of local thermodynamic equilibrium, taking partial frequency redistribution (PRD) effects into account. This problem is extremely challenging from a computational standpoint and, so far, most studies have been carried out by either modeling PRD effects under the angle-average approximation or by considering academic models of the solar atmosphere. Thanks to a new solution strategy, applicable to atomic systems that allow for a linearization of the problem, accurate solutions can now be routinely obtained in realistic 1D models, taking angle-dependent (AD) PRD effects into account. Aims. This work is aimed at assessing the suitability and performance of this new approach to handling dynamic scenarios. At the same time, it aims to explore the joint impact of magnetic fields and bulk velocities on the scattering polarization profiles of strong resonance lines, accounting for AD PRD effects and considering more realistic atmospheric models than in previous investigations. Methods. By using a two-level atomic model for neutral calcium, we synthesized the intensity and polarization profiles of the Ca I 4227 Å line. Our calculations were performed in 1D atmospheric models, both semi-empirical and extracted from 3D magnetohydrodynamic simulations, including vertical bulk velocities and magnetic fields of arbitrary strength and orientation, both constant and varying with height. Results. We obtained accurate solutions after only a few iterations across all considered scenarios. Even when formulating the problem in the observer’s reference frame, the frequency and angular grids required for accurate results were easily manageable. The calculated profiles showed the expected signatures of bulk velocities: wavelength shifts, enhancement of the line-core polarization amplitude, and prominent asymmetries in the wing signals. The results obtained in atmospheric models with complex thermal, dynamic, and magnetic structures unveiled the broad diversity of features in the emergent radiation that can be expected from realistic scenarios. Conclusions. The presented results assess the suitability of the proposed solution strategy and its parallel implementation, thus supporting its generalization to the 3D case. Our applications in increasingly realistic atmospheric models showed the difficulty related to precisely establishing the individual weight of bulk velocities and magnetic fields in the shape of the emergent profiles. This highlights the need to account for both these physical ingredients to perform reliable inversions of observed scattering polarization profiles.

Testing pulsation diagnostics in the rapidly oscillating magnetic Ap star γ Equ using near-infrared CRIRES+ observations

Context. Pulsations of rapidly oscillating Ap stars and their interaction with the stellar magnetic field have not been studied in the near-infrared (near-IR) region despite the benefits these observations offer compared to visual wavelengths. The main advantage of the near-IR is the quadratic dependence of the Zeeman effect on the wavelength, as opposed to the linear dependence of the Doppler effect. Aims. To test pulsation diagnostics of roAp stars in the near-IR, we aim to investigate the pulsation behaviour of one of the brightest magnetic roAp stars, γ Equ, which possesses a strong surface magnetic field of the order of several kilogauss and exhibits magnetically split spectral lines in its spectra. Methods. Two magnetically split spectral lines belonging to different elements, the triplet Fe I at 1563.63 nm and the pseudo-doublet Ce III at 1629.2 nm, were recorded with CRIRES+ over about one hour in the H band with the aim of understanding the character of the line profile variability and the pulsation behaviour of the magnetic field modulus. Results. The profile shapes of both studied magnetically split spectral lines vary in a rather complex manner probably due to a significant decrease in the strength of the longitudinal field component and an increase in the strength of the transverse field components over the last decade. A mean magnetic field modulus of 3.9 kG was determined for the Zeeman triplet Fe I at 1563.63 nm, whereas for the pseudo-doublet Ce III at 1629.2 nm we observe a much lower value of only about 2.9 kG. For comparison, a mean field modulus of 3.4kG was determined using the Zeeman doublet Fe II at 6249.25 in optical PEPSI spectra recorded just about two weeks before the CRIRES+ observations. Different effects that may lead to the differences in the field modulus values are discussed. Our measurements of the mean magnetic field modulus using the line profiles recorded in different pulsational phase bins suggest a field modulus variability of 32 G for the Zeeman triplet Fe I at 1563.63 nm and 102 G for the pseudo-doublet Ce III at 1629.2 nm.

Deconstructing Photospheric Spectral Lines in Solar and Stellar Flares

During solar flares, spectral lines formed in the photosphere have been shown to exhibit changes to their profiles despite the challenges of energy transfer to these depths. Recent work has shown that deep-forming spectral lines are subject to significant contributions from regions above the photosphere throughout the flaring period, resulting in a composite emergent intensity profile from multiple layers of the atmosphere. We employ radiative–hydrodynamic and radiative transfer calculations to simulate the response of the solar/stellar atmosphere to electron beam heating and synthesize spectral lines of Fe i to investigate the line-of-sight velocity fields information available from Doppler shifts of the emergent intensity profile. By utilizing the contribution function to deconstruct the line profile shape into its constituent sources, we show that variations in the line profiles are primarily caused by changes in the chromosphere. Up-flows in this region were found to create blueshifts or false redshifts in the line core dependent on the relative contribution of the chromosphere compared to the photosphere. In extreme solar and stellar flare scenarios featuring explosive chromospheric condensations, redshifted transient components can dominate the temporal evolution of the profile shape, requiring a tertiary component consideration to fully characterize. We conclude that deep-forming lines require a multicomponent understanding and treatment, with different regions of the spectral line being useful for probing individual regions of the atmosphere’s velocity flows.

A Study on Crenulate - Shaped Bays in Coastline of Sri Lanka

Various research studies have been reported in the literature investigating the crenulate-shaped bays that are frequently seen in coastlines all over the world and these coastal bays are recognized as the most stable naturally forming beaches under oblique wave attacks mostly due to swell dominant seas. Although many crenulated bays exist in Sri Lanka coastline, no considerable attention has been given so far to investigate their characteristics. The authors have studied the temporal and spatial variations of crenulated bays in many parts of the coastline of Sri Lanka using Google Earth images. Based on the detailed analysis carried out to investigate the shape of the bay profiles using empirical formulations, a hyperbolic tangent formula has been identified as the best fit for crenulated bays in the coastline of Sri Lanka. Considering various coastal sectors and monsoon seasons, different relationships have been derived between the coefficients a and b of the hyperbolic tangent formula. A relationship that has been developed co-relating the coefficient a with few coastal parameters is also discussed. Since many parts of the Sri Lanka coastline are subjected to severe erosion despite the construction of a variety of shore protection structures in traditional ways, a new approach is suggested for carrying out such work where the coastal structures will be aligned in predetermined directions depending on the coastal stretch so that stable crenulated bays will be naturally formed in between these structures, stabilizing the entire coastal stretch. This approach will be very useful in managing coastal erosion problem in the future.