Ridge Features Research Articles

Novel intense blue emitting Bi2Zr2O7:Ce3+ nanocomposites insertion into flexible polymer films for anti-counterfeiting, long-term storage fingerprints, and display device applications

The development of multifunctional organic/inorganic hybrid materials for anti-counterfeiting and food packaging applications can be achieved through the use of polymer nanocomposites containing poly(vinyl alcohol) (PVA) and chitosan (CS), as well as Ce3+-activated Bi2Zr2O7 nanocomposites (PCBC NCs). However, synthetic methods for these nanocomposites are often time- and energy-intensive, leading to heterogeneous films that require compatibilizers to disperse the organic matrix's inorganic nanoparticles (NPs). This study used a simple solution casting approach to impregnate the appropriate phosphor sample into PVA-CS (PC) flexible films, resulting in luminous ink for high-security anti-counterfeiting applications. Using this nanocomposite ink offers an even higher level of security, as the prints can be submerged in copper chloride (CuCl2) aqueous solutions to quench the luminous message. The masked fingerprints used for long-term storage (up to 12 months) exhibit stable level 1–3 ridge features with high contrast and sensitivity, which may improve printing quality and performance in the fight against counterfeiting. In addition, a mathematical model implemented in Python-based software was used to investigate the latent fingerprints of level 1–2 ridge features.

Novel green emanating Sr6Al4Y2O15:Er3+ nanophosphor for thermal sensing, data security and personal identification

A novel Er3+ activated Sr6Al4Y2O15 (SAYO:Er) (1–5 mol %) green emitting nanophosphors (NPs) were fabricated. Prepared samples were confirmed for their nanoregime using the advanced characterization techniques. Photoluminescence (PL) emission spectra showed the strongest peak identified at 564 nm with 4S3/2→4I15/2, which is responsible for the intense green colour. A new fluorescence-based platform has been set up to visualize latent fingerprints (LFPs) and latent lip prints (LLPs). With the exposure to ultraviolet light of wavelength of 375 nm, the level -III ridge features which are generally difficult to observe on various surfaces, LFPs can be observed for longer period due to the dual nature of binding specificity and excellent fluorescence properties. Also the LFPs were resulted in higher contrast, high sensitivity and no background interference. For the first time, the latest versions of YOLOv8x program is used for to study the Level-I and Level-II features are readily visible in the enlarged and minute FP. Thrombosis is considered as a major threat to the society as it leads to death and disability. Despite a number of risk factors, oxidative stress may appear to be the primary marker of thrombosis. Therefore, SAYO:Er is analyzed for its ameliorating effect on oxidative stress and thrombosis. Interestingly, SAYO:Er showed antioxidant property by scavenging the DPPH. In addition, SAYO:Er inhibited platelet aggregation induced by ADP. Overall, the findings made it often evident that SAYO:Er NPs provide a novel approach to advanced technology inmedical and forensic applications.

Contribution of ALOS PALSAR DEM Imagery to the Study of Geological and Morphostructural Lineaments of Boma Trough Block, Onshore Coastal Basin of D.R. Congo

Geological and morphostructural lineaments are considered as the surface expression of geological structures and linear features of valleys, ridges and river drainage systems. Lineaments extracted from satellite images have always been effective in understanding the structural context of a region. The lineaments observed on the surface provide information on the tectonic stresses that have affected an area and give a first impression of the probable existence and orientation of geological structures that may constitute oil traps at depth. This study aims to semi-automatically extract lineaments (by combining the use of GIS software, remote sensing and operator intervention) in Boma Trough Block, an oil block located to the east of D.R. Congo Coastal Basin and still poorly explored. The satellite image used in this work is an ALOS PALSAR DEM with a spatial resolution of 12.5m, enhanced in traditional hillshade (solar azimuth of 315° and 45°) and multidirectional hillshade; which allowed the extraction of 3129 lineaments, with lengths ranging from 0.16 to 3.79 km, oriented on multidirectional hillshade at 47.1% along the NW-SE direction, at 44.1% along the NE-SW, 7.3% for N-S and 1.4% for E-W. Lineament density mapping revealed that areas with high and very high densities cover 43% of ??the study area, where the Precambrian basement is largely outcropping, while low and very low density areas represent 41% and contain sedimentary formations. Areas with moderate densities covered ??16%. The lineaments extracted from the DEM image compared to the reality on the field show a positive correlation. This confirms the important contribution of the processing approach used in this study.

Desired highly efficient Eu3+ activated GdCaAl3O7 orange-red emanating nanophosphors for UV excitable forensic and advanced information encryption and decryption applications

In the present work, orange-red emitting Eu3+ (1–8 mol %) doped GdCaAl3O7 nanophosphors are prepared by a simple solution combustion route. X-ray diffraction studies reveal that the prepared phosphors are in the tetragonal phase without any additional impurity peaks. Morphological studies clearly show the irregularly shaped network-type structures of the phosphors. Under UV light excitation (∼393 nm), photoluminescence (PL) emission peaks are recorded at ∼578, 590, 617, 651, and 701 nm, which correspond to the 5D0→7F0, 1, 2, 3, 4 transitions of Eu3+ ions, respectively. The photometric properties of the prepared nanophosphors reveal color tuning from the orange-red region to the pure red region with a color purity of ∼88.14 %. The optimized GdCaAl3O7:Eu3+ (3 mol %) nanophosphor is evaluated from an application perspective by developing latent fingerprints and lip prints. The visualized latent fingerprints under ∼254 and 375 nm excitations undoubtedly reveal levels I–III ridge features on various surfaces. The developed lip prints can discriminate the Suzuki's and Tsuchihashi’s categories. The information encryption and decryption capabilities of the nanophosphor on various surfaces were investigated by following screen printing technology, dip-pen and brush mode. The printed patterns revealed sharp, high resolution, uniform ink distribution under ∼254 nm UV excitation and invisible upon normal light. The overall results revealed that prepared GdCaAl3O7:Eu3+ (1–8 mol %) NPs exhibit excellent structural stability and intensive PL emission endorsing its applicability wide scope of areas.

Potential applications of Fe3+-activated Sr9Al6O18 nanophosphors for fingerprint detection, oxidative stress, and thrombosis treatment

This study reports on the synthesis of Fe3+-activated Sr9Al6O18 nanophosphors (SAO:Fe NPs) using a simple solution combustion process, which emits a pale green light and possesses excellent fluorescence properties. An in-situ powder dusting method was utilized to extract unique ridge features of latent fingerprints (LFPs) on various surfaces using ultra-violet 254 nm excitation. The results showed that SAO:Fe NPs possess high contrast, high sensitivity, and no background interference, enabling the observation of LFPs for longer periods. Poroscopy, which is the examination of sweat pores on the skin's papillary ridges, is important in the identification process, and the YOLOv8x program based on deep convolutional neural networks was used to study the features visible in FPs. The potential of SAO:Fe NPs to ameliorate oxidative stress and thrombosis was analyzed. The results showed that SAO:Fe NPs have antioxidant properties by scavenging 2,2-diphenylpicrylhydrazyl (DPPH) and normalized the stress markers in NaNO2-induced oxidative stress in Red Blood Cells (RBC). In addition, SAO:Fe inhibited platelet aggregation induced by adenosine diphosphate (ADP). Therefore, SAO:Fe NPs may have potential applications in advanced cardiology and forensic sciences. Overall, this study highlights the synthesis and potential applications of SAO:Fe NPs, which can enhance the sensitivity and specificity of fingerprint detection and provide insights into developing novel treatments for oxidative stress and thrombosis.

Pilot Study on the Visualization of Latent Fingerprints and Naked Eye Detection of Hg2+ and Zn2+ Ions in Aqueous Media Using Ninhydrin-Based Thiosemicarbazone.

Here, we described a cheap and effective chemosensor (NHPyTSC) that can distinguish Hg2+ and Zn2+ ions from other metal ions and evaluated this phenomenon using several spectroscopy techniques. With the addition of mercury and zinc ions, the proposed chemosensor in particular showed noticeable changes in color and absorption spectra. Additionally, by including EDTA in the NHPyTSC-Hg2+ and NHPyTSC-Zn2+ solutions, colorimetry readings can be reversed. We developed a molecular-scale sequential information processing circuit and presented the "writing-reading-erasing-reading" and "multiwrite" behaviors in the form of binary logic based on the great reversibility of this process. Moreover, by sequentially adding Hg2+, Zn2+, and EDTA, NHPyTSC imitates a molecular keypad lock and molecular logic gates. Density functional theory (DFT) investigations provided more evidence of the Hg2+ and Zn2+ ions' ability to attach to NHPyTSC. The most interesting part of this work is that a study on the latent fingerprint detection of the powder compound revealed that NHPyTSC exhibits good adherence and finger ridge features without background stains. When compared to black and white fingerprint powders, it is discovered that the NHPyTSC powder produces results that are remarkably clear on the majority of surfaces. This demonstrated their potential for real-world use, particularly in the area of criminal investigations.

Orange-red emitting MoO3:Sm3+ transparent nano-composite films for anti-counterfeiting and data secure applications

Poly(vinyl alcohol) (PVA) and chitosan (CS) based nanocomposites (NCs) filled by various weight percent of modified MoO3:Sm3+ (MS) nanoparticles (NPs). For the preparation, folic acid (FA) up to 150 mg were used via ultrasonication method then was cast to thin films. The changes in the structural properties of the prepared samples were examined by X-ray diffraction. FT-IR spectroscopy indicated the possible interactions of the MS NPs with the PVA/CS backbones through the absorption bands. MS NPs were homogeneously dispersed in the polymer matrix at nanoscale. The photoluminescence (PL) emission spectra of PVA/CS-MS NCs excited by 404 nm wavelength, with the key emission peaks centred at ∼ 563, ∼600 and ∼ 647 nm are mainly attributed to transitions from 4G5/2→6H5/2, 4G5/2→6H7/2, 4G5/2→6H9/2 respectively. The powder dusting method was used to visualize the latent fingerprints (LFPs) on various surfaces under 404 nm excitation. Additionally, PVA/CS matrix was masked on the developed fingerprints (FPs) for long term storage. The results clearly indicated that, the level 1–3 ridge features were stable up to 180 days with superior contrast and sensitivity. The optimized phosphor powder is used to fabricate unclonable security ink and brush mode technique was used to mark on various surfaces and exposed to UV 404 nm light. The results revealed that the present phosphor can garner significant interest for the use in personal identification and security encoding.

Tectono-magmatic evolution of the Greenland−Iceland−Norway ridge complex and the Jan Mayen hotspot in the Arctic Atlantic Ocean: Constraints from in situ trace elements and Sr isotopes of minerals

The subarctic North Atlantic Ocean has experienced a complex and gradual magmatic evolution, including continental breakup, mature seafloor spreading, and episodic ridge jumps. Here, we present new in situ major-element, trace-element, and Sr isotopic compositions for minerals (olivine, clinopyroxene, and plagioclase) from the Jan Mayen microcontinent (Integrated Ocean Drilling Program [IODP] Sites 907 and 985), Reykjanes Ridge (Site 983), Greenland Basin (Site 913), and Knipovich Ridge (Site 911) volcanic samples in the Arctic Atlantic Ocean. The Jan Mayen hotspot−type and Iceland plume−type volcanic rocks have a common magma source. The former were likely derived from the latter by further fractional crystallization, resulting in their distinct geochemical features. The in situ incompatible element and isotopic compositions show that the normal mid-ocean-ridge basalt spreading ridge feature for the older (>14 Ma) system and the enriched plume feature for the younger (1.521 Ma and 1.049 Ma) system likely indicate plume-ridge interaction and the evolution from mid-ocean-ridge−type to plume-type magmatism beneath the Norwegian−Greenland Sea. The disequilibrium of Sr isotopes in plagioclase among the groundmass, phenocryst cores, and rims is likely due to heterogeneous compositions beneath the North Atlantic Ocean basin, with the contamination of thick continental crust and the influence of H2O-enriched melts originating from the deep Iceland plume.

Research on Navigation Line Extraction Algorithm Based on Onion Ridge Edge Features

Aiming at the phenomenon that the existing shallot harvester cannot realize the automatic operation in the harvesting process of green onion, a navigation path acquisition method of green onion harvester is proposed, which is applied to the automatic driving of the shallot harvester. Firstly, the original image is grayed by G-R algorithm, and then the gray image is segmented by maximum inter-class variance method to obtain binaryized image; secondly, the morphological operation is applied to the binary map for noise reduction processing and hole filling to obtain the green onion ridge with good connectivity; then, according to the geometric characteristics of the green onion ridge, the left and right edge feature points of the green onion ridge are detected, and the midpoint of the left and right edge feature points is taken as the navigation key point; finally, the navigation key point is fitted with the least squares method. Gets the navigation line for the green onion ridge. Experimental results show that the proposed algorithm takes about 71ms to process an image with a resolution of 450 pixels and 330 pixels, and the average error angle of the navigation line is 0.649°. The algorithm can accurately and quickly extract the navigation line of the green onion ridge, and can provide accurate navigation information for the automatic driving of the green onion harvester.

Kinematic-chemical Analysis and Time Tagging for the Diagonal Ridge Structure of the Galactic Outer Disk with LAMOST Red-giant Branch Stars

We investigate the kinematic-chemical distribution of red-giant branch stars from the LAMOST survey crossed matched with Gaia DR2 proper motions, and present time tagging for the well-known ridge structures (diagonal distributions for V R in the R, V ϕ plane) in the range of Galactocentric distance R = 8 to 15 kpc. We detect six ridge structures, including five ridges apparent in the radial velocity distribution and three ridges apparent in the vertical velocity, the sensitive time of which to the perturbations are from young population (0–3 Gyr) to old population (9–14 Gyr). Based on an analysis of the evolution of angular momentum distribution, we find that four ridges are relatively stationary, while another is evolving with time, which is confirmed by the difference analysis at different populations and supporting that there might be two kinds of dynamical origins. Furthermore, ridge features are also vividly present in the chemical properties ([Fe/H], [α/Fe]). The comparison between the north and south hemispheres of the Galaxy does show some differences and the ridge features are asymmetrical. Moreover, we find that diagonal ridge structures may affect the shape of the rotation curve, which is manifested as fluctuations and undulations on top of a smooth profile. Finally we speculate that the bar dynamics should be not enough to explain all ridge properties including the break feature in the V Z –L Z plane.

Neighbor Reweighted Local Centroid for Geometric Feature Identification.

Identifying geometric features from sampled surfaces is a significant and fundamental task. The existing curvature-based methods that can identify ridge and valley features are generally sensitive to noise. Without requiring high-order differential operators, most statistics-based methods sacrifice certain extents of the feature descriptive powers in exchange for robustness. However, neither of these types of methods can treat the surface boundary features simultaneously. In this paper, we propose a novel neighbor reweighted local centroid (NRLC) computational algorithm to identify geometric features for point cloud models. It constructs a feature descriptor for the considered point via decomposing each of its neighboring vectors into two orthogonal directions. A neighboring vector starts from the considered point and ends with the corresponding neighbor. The decomposed neighboring vectors are then accumulated with different weights to generate the NRLC. With the defined NRLC, we design a probability set for each candidate feature point so that the convex, concave and surface boundary points can be recognized concurrently. In addition, we introduce a pair of feature operators, including assimilation and dissimilation, to further strengthen the identified geometric features. Finally, we test NRLC on a large body of point cloud models derived from different data sources. Several groups of the comparison experiments are conducted, and the results verify the validity and efficiency of our NRLC method.

Fingerprint classification combined with Gabor filter and convolutional neural network

A fingerprint is an impression left by the friction ridges of a human finger. A fingerprint classification system groups fingerprint according to their characteristics and therefore helps to match a fingerprint against an extensive database of fingerprints. The Henry classification system is widely used among fingerprint classification systems. Some researchers have used traditional machine learning or deep learning for fingerprint classification. Nevertheless, traditional algorithms cannot extract the depth features of the fingerprint, and most deep learning algorithms lack fingerprint image enhancement. So, this paper combined the Gabor Filter and Convolutional Neural Network to extract fingerprint features. The model has two channels, one is a Deep Convolutional Neural Network (DCNN), and the other is a Shallow Convolutional Neural Network (SCNN). The DCNN consists of a neural network with eight layers, which can extract deep features of the fingerprint. The SCNN consists of Gabor Filter and a neural network with two layers that can extract features from clear fingerprint images. This paper uses NIST Special Database 4 for experiments. Experimental results show that the model proposed in this paper has achieved 91.4% accuracy. Compared with other algorithms, this model has higher accuracy than others. It shows that combined with the Gabor Filter and Convolutional Neural Network can better extract the ridge features of fingerprint images.

MORGen: an Algorithm to Compute Spreading Centre and Transform Geometries from Simple Initial Plate Boundaries and Euler Rotations

The age structure of the global ocean floor is a key feature in paleogeographic reconstructions, which in turn forms the quantitative basis for Earth System Science. However, much of the ocean floor in paleogeographic reconstructions has been lost to subduction. The age structure of such lost ocean floor is constructed from the reconstructions of adjacent continents, using the relative rotations, around Euler poles to predict the geometry of spreading centres and transform faults. Building such mid-ocean ridge features in paleogeographic reconstructions is laborious, as it requires redrawing of ridge-transform systems upon every Euler pole shift in the model. In this paper, we present the Mid-Ocean Ridge Generator (MORGen) algorithm, based on pyGPlates. MORGen reduces the laborious task by automating the drawing of mid-ocean ridge geometries from geometrically simple plate boundary input assuming ridge-perpendicular spreading and adjusts ridge geometries in a simplest-scenario fashion by gradually adjusting ridge orientation and transform fault length upon Euler pole shifts, inspired by observations from the modern sea floor. The code takes as input curved line features, representing approximate divergent plate boundaries, and a set of Euler poles. These are then converted into spreading centre-transform geometries. Upon Euler pole shifts, the geometries are adjusted to fit the set of small circles and great circles dictated by the new Euler pole. For studies of paleo-environment and paleo-oceanography MORGen can be used in combination with other algorithms for full reconstructions of ocean floors, including their age, bathymetry, and roughness. For in-situ preserved ocean floor, the paleo-age distribution can be reconstructed directly in high resolution from geophysical and geological data from the modern ocean floor and MORGen would not normally be the option of choice. In cases where models contain ocean floor that has now been subducted, MORGen straightforwardly facilitates mid-ocean ridge geometry reconstruction. To illustrate how well the MORGen algorithm reproduces real ocean floor age structure, we show a synthetic ridge evolution for the South Atlantic and Southern Oceans and compare this to geophysically constrained ocean floor geometry. In addition, we show examples of use cases where direct (re)construction of mid ocean ridges is not possible: now-subducted ocean basins in the Mediterranean region and an ocean in a future supercontinent scenario.

Supplying a medieval metropolis: water management and agriculture in the hinterland of early Islamic Basra

Following its foundation in the 630s CE, medieval Basra rapidly expanded to became one of the most populous cities of southern Iraq and the wider Gulf region. At its foundation, the city’s surrounding environment appears to have been poorly suited to sustaining a large urban population. This paper examines the different ways in which the early Islamic population of Basra transformed the immediate environs of the city to improve the urban water supply and the agricultural potential of the city’s hinterland. In particular, this included the construction of substantial canals connecting Basra with sources of water such as the marshes to the north of the city and the Shaṭṭ al-cArab—the river which forms at the confluence of the Tigris and Euphrates and flows past Basra to the Gulf. The tidal influence of the Gulf causes the water level of the Shaṭṭ al-cArab to rise and fall daily and, by exploiting this characteristic, the medieval population of Basra could irrigate large swathes of land surrounding the city. Analysis of historic satellite imagery reveals possible evidence for the infrastructure that made this possible—including the remains of field systems bounded by, and interspersed with, canals as well as large raised linear ridge features which occur in tandem with relict canal systems. This paper critically assesses the evidence for the dating of these features, potential scenarios for how they functioned and their relationship to the medieval city of Basra.

Seamount seascape composition and configuration shape Southwest Indian Ridge fish assemblages

Seamounts are commercially important fishing grounds. Yet, little is known about their physical characteristics as fish habitat, important for informing conservation and ecosystem-based management.This study examines how multiscale seabed spatial heterogeneity influences commercially important fish families at three Southwest Indian Ridge seamounts (Coral Seamount, Melville Bank and Atlantis Bank). We quantified seascape heterogeneity from bathymetry and geomorphological habitat maps and identified 15 focal fish families from video data. Fish-habitat associations were examined using spatial pattern metrics that measured terrain morphology, seascape composition (variety and relative abundance of patch types) and seascape configuration (spatial arrangement of patches). Broader seascape context was characterised by geographic location and water depth. Multivariate regression trees and random forests modelled fish-habitat associations and identified the most influential explanatory variables.Assemblage characteristics and individual families were strongly influenced by geographic location and depth, and at finer scales (500 m buffers) seascape composition and configuration helped explain fish-habitat associations. Spatially continuous summit habitat and complex shaped ridge features supported high abundance and diversity of commercial fish families. Metrics of seascape composition and configuration (i.e., habitat size, shape and structural connectivity) had higher predictive power than the terrain metrics commonly used in developing proxies for deep-water fish species and biodiversity.These outcomes indicate that seascape metrics, commonly applied on land and in shallow marine environments, are also relevant environmental predictors of fish distributions in deep-sea environments. We highlight strong context dependency and depth-specific associations that hinder attempts to draw wider generalisations on fish-seascape linkages for seamounts.

Benthic megafaunal biodiversity of the Charlie-Gibbs fracture zone: spatial variation, potential drivers, and conservation status

The Charlie-Gibbs Fracture Zone (CGFZ) is a prominent geological feature offsetting the Mid-Atlantic Ridge (MAR), consisting of two parallel fractures, creating a highly variable seafloor bathymetry. It has been defined as the most important latitudinal biodiversity transitional zone on the MAR. Despite this recognition, the faunal communities living on the fracture zone have not been extensively described. A remotely operated vehicle (ROV) was utilised during the TOSCA (Tectonic Ocean Spreading at the Charlie-Gibbs Fracture Zone) survey. The survey included five ROV video transects at depths between 560 and 2900 m. The objectives of the study were to use this video footage to quantify benthic megafaunal density and biodiversity patterns on the CGFZ and their environmental drivers. Species accumulation curves and generalised additive modelling show that depth and the presence of hard substrates play an important role in explaining species richness and abundance at the CGFZ. Coral taxa showed highest abundance between depths of 1500 and 2000 m, while sponge taxa were more abundant between 1750 and 2250 m. A dense sponge aggregation was identified on a ridge feature at 2250 m depth. The high biodiversity and presence of dense sponge aggregations and coral gardens found in this study highlight the need for detailed surveys to help support decisions made by governing bodies on the protection status of the CGFZ.

Thin film rheology via focused laser spike thermocapillary dewetting

Focused laser spike (FLaSk) dewetting employs a localized heat source to create thermocapillary-induced trench-ridge morphologies. Using a universal heating substrate coupled with optical microscopy, we have studied the dewetted ridge feature for several distinct thin films of glass-forming materials. The evolution of the ridge’s radius over time can be modeled to derive a maximum dewetted radius and a characteristic decay time. The decay time shows an Arrhenius behavior when compared to the mean melt pool temperature, leading to a characteristic activation energy. An effective viscosity can also be defined. These descriptors demonstrate FLaSk’s potential for rapid metrology.

Understanding the surface generation mechanism during micro-scratching of Ti-6Al-4V

A lot of grinding research in the past has been emulated using single grit scratching. This limits studying surface generation mechanism due to overlapping scratches inherent to the grinding process. It not only affects the surface generation mechanism, but also limits studying elastic recovery which has a significant effect on the final form and topography including the roughness generated after grinding. Taking Ti-6Al-4V as a testbed, this investigation was directed on comparing single scratches with adjacent scratches, which are often referred to as double scratches in literature. During the experiments, the effect of scratch speed and the scratch separation distance on the cutting forces, material pile-up area ratio (PA), groove depth, material removal area (MRA), and sub-surface deformation were investigated. It was found that the scratch speed significantly affects the pile-up and groove depth because of phenomena like stress build-up and elastic recovery. A complementary analytical model of ploughing and shearing forces developed here led to the observation that the minimum chip thickness can only be around 0.1 to 0.2 times the radius of the indenter. Elastic recovery was found to be larger at the middle of the scratch, which was confirmed by the stress-strain relations derived from the FEM simulations. It was also observed that the spacing between two subsequent scratches can significantly affect the scratched surface quality. These experiments show that the severe ploughing and mid-region ridge features can be avoided by having the scratch pitch to be at least one third of the grit tip radius.

SiO2@LaOF:Eu3+ in white light emitting diodes optic efficiency enhancement

The earliest intense red hue compound of SiO2@LaOF:Eu3+ core-shell nanostructures (NS) was created utilizing a basic solvothermal technique and heat processing. The produced core-shell particles are spherical, non-agglomerated, and have restricted size dispersion. Photoluminescence (PL) radiation spectra exhibit sharp maximums in 593, 611, and 650 nm, corresponding with 5D0 -- 7FJ (J=0, 1, 2) Eu3+ conversions. The Judd-Ofelt (J-O) hypothesis helps determine the spectrum strength indices and Eu-O ligand activities. The CIE coordinates are x=0.63, y=0.36, nearly equal the NTSC coordinates which are x=0.67, y=0.33. Because of the CCT level of 3475 K, which is lower than 5000 K, this phosphor is appropriate for warm light-emitting diodes. To visualize latent fingermarks both porous and non-porous substrates, the fluorescent labeling marker adapted core-cover SiO2 (coat III)@LaOF:Eu3+ (5 mol%) was utilized. With no background influence, the fingermarks obtained are exceedingly sensible and exclusive, permitting for fingerprint ridge features ranging from level-I to level-III. The findings indicate the significant enhancement in the illumination of corecover NS as a responsive operational nanoparticle for increased forensics and firm status illuminating implementations.

Axisymmetric ridges and circumferential buckling of indented shells of revolution.

When poking a thin shell-like structure, like a plastic water bottle, experience shows that an initial axisymmetric dimple forms around the indentation point. The ridge of this dimple, with increasing indentation, eventually buckles into a polygonal shape. The polygon order generally continues to increase with further indentation. In the case of spherical shells, both the underlying axisymmetric deformation and the buckling evolution have been studied in detail. However, little is known about the behavior of general geometries. In this work we describe the geometrical and mechanical features of the axisymmetric ridge that forms in indented general shells of revolution with non-negative Gaussian curvature and the conditions for circumferential buckling of this ridge. We show that under the assumption of "mirror buckling," a single unified description of this ridge can be written if the problem is nondimensionalized using the local slope of the undeformed shell midprofile at the ridge radial location. However, in dimensional form the ridge properties evolve in quite different ways for different midprofiles. Focusing on the indentation of shallow shells of revolution with constant Gaussian curvature, we use our theoretical framework to study the properties of the ridge at the circumferential buckling threshold and evaluate the validity of the mirror buckling assumption against a linear stability analysis on the shallow shell equations, showing very good agreement. Our results highlight that circumferential buckling in indented thin shells is controlled by a complex interplay between the geometry and the stress state in the ridge. The results of our study will provide greater insight into the mechanics of thin shells. This could enable indentation to be used as a means to measure the mechanical properties of a wide range of shell geometries or used to design shells with specific mechanical behaviors.