Orthogonal System Research Articles

Influence of polarization on demodulation methods for determining the SRI value for a single TFBG and an orthogonal grating system

This paper presents a comparison of the spectra of single and cascade of two tilted fiber Bragg grating (TFBG) sensors. These sensors are characterized by high sensitivity to the refractive index. The disadvantage of a single TFBG is cross-sensitivity to changes in the polarization of the light introduced to the sensor, which is visible both when analyzing individual modes and when analyzing a wide spectral range with global demodulation algorithms. In response, a cascade structure was created consisting of a set of two TFBGs connected in series with 90 degrees of mutual rotation between them. This work presents a comparison of the polarization cross-sensitivity of sensor spectral demodulation algorithms for measuring the surrounding refractive index (SRI). While maintaining the high accuracy of the SRI measurement typical of TFBG gratings, a cascade of two such gratings properly oriented toward each other allows for a significant reduction in the sensitivity of the SRI measurement to polarization changes. Importantly, the reduction in the polarization cross-sensitivity is significantly greater for the demodulation methods that determine the cutoff wavelength shift; owing to this, a perpendicular TFBG(P-TFBG) measurement system without polarization control remains highly reliable. The application of the proposed P-TFBG system also allows greater SRI sensitivity to be obtained for a single tilted grating with the same tilt angle.

Rate of convergence of certain Fourier series of functions of generalized bounded variation

In this paper, we discuss the rate of convergence of the rational Fourier series and conjugate rational Fourier series of functions of generalized bounded variation. In particular, well- known Wiener’s and Siddiqi’s theorems for functions of p-bounded variation are proved in more general complete rational orthogonal system. Also some results are obtained for a class of functions wider than the class of functions of bounded variation and of {n\alpha }-bounded variation.

Microstructure and development of the dermal ossicles of Antarctopelta oliveroi (Dinosauria, Ankylosauria): A complex morphogenetic system deciphered through three-dimensional X-ray microtomography.

Ankylosaurs were a group of heavily armored non-avian dinosaurs (Dinosauria, Ankylosauria), represented by a relatively abundant fossil record from the Cretaceous of North and South America. Their dermal skeleton was characterized by large osteoderms whose development and functional role have been largely investigated. However, interstitial small ossicles, forming between these osteoderms, have been far more overlooked and it remains unknown whether they were formed through the ossification of a preexisting fibrous matrix of connective tissue (i.e., metaplasia) or by a cell-induced differentiation of new fiber bundles followed by mineralization (i.e., neoplasia sensu (Zeitschrift für Wissenschaftliche Zoologie, 1858, 9, 147)). Here, we propose a hypothesis on the developmental origin of these small ossicles in the ankylosaurian Antarctopelta oliveroi using light microcopy, scanning electron microscopy and three-dimensional virtual histology through propagation phase-contrast synchrotron radiation micro-computed tomography (PPC-SRμCT). Ossicles are located in the dermis. They are composed of two layers: (1) a thin external layer, and (2) a thick basal plate, composed of collagen fiber bundles, which forms the main part of the ossicle. The external layer is made of a smooth, vitreous mineralized tissue that does not look like bone. The basal plate, however, is of osseous origin. In this basal plate, the collagen fiber bundles are organized in two orthogonal systems: one horizontal-observable in cross-sections-and one vertical-observable in the primary plane of sections sensu (Journal of Vertebrate Paleontology, 2004, 24, 874). The horizontal system is itself composed of successive layers of collagen fiber bundles arranged into an orthogonal plywood-like structure. The bundles of the vertical system radiate from the center of the ossicle at the level of the transition between the external layer and the basal plate and run towards the periphery of the basal plate. Their thickness increases from the center of the ossicle towards its periphery. Numerous bundles of the vertical system form thin threads that interweave and penetrate within the thick bundles of the horizontal system. Our new data suggest that the ossicles were at least partially formed by metaplasia, that is, through the ossification of a preexisting fibrous matrix of connective tissue. This process was probably supplemented by a cell-induced differentiation of new fiber bundles laid down prior to their incorporation into the fibrous system and its mineralization. This process looks more akin to neoplasia sensu (Zeitschrift für Wissenschaftliche Zoologie, 1858, 9, 147) than to metaplasia. Consequently, metaplastic and neoplastic processes may coexist in these ossicles with a possible differential expression during ontogeny.

Enhanced Spatial Modulation Based Orthogonal Time Frequency Space System

Enhanced Spatial Modulation Based Orthogonal Time Frequency Space System

Fluorescence spatial anisotropy of emission dipoles in an orthogonal imaging system

In this study, we explore the relatively unexplored spatially anisotropic fluorescence emission induced by rotationally polarized excitation light in orthogonal imaging systems, a phenomenon that is particularly pronounced in orthogonal setups compared to coaxial configurations. Despite its significance, this aspect has been largely neglected, given the prevalent use of coaxial Fluorescence Polarization Microscope (FPM) setups. Our research endeavors to bridge this gap by formulating a physical model to investigate the polarization-dependent emission of dipoles and the corresponding fluorescence signal within an orthogonal imaging configuration. Additionally, we introduce the Fluorescence Spatial Anisotropy Index (FSAI) to quantify fluorescence spatial anisotropy.

საქართველოს რელიეფის მორფოსტრუქტურული ანალიზი

As a result of the morphostructural analysis of the relief of Georgia, a scheme of tectonic faults has been compiled, the validity of which has been reinforced by the study of space materials. The faults represent straight-line structures and create an orthogonal diagonal system grid. The scheme explains the morphology of many geological structures and geological outcrops, as well as the peculiarities of the location of mineral deposits.

A Hybrid Network Integrating MHSA and 1D CNN–Bi-LSTM for Interference Mitigation in Faster-than-Nyquist MIMO Optical Wireless Communications

To mitigate inter-symbol interference (ISI) caused by Faster-than-Nyquist (FTN) technology in a multiple input multiple output (MIMO) optical wireless communication (OWC) system, we propose an ISI cancellation algorithm that combines multi-head self-attention (MHSA), a one-dimensional convolutional neural network (1D CNN), and bi-directional long short-term memory (Bi-LSTM). This hybrid network extracts data features using 1D CNN and captures sequential information with Bi-LSTM, while incorporating MHSA to comprehensively reduce ISI. We analyze the impact of antenna numbers, acceleration factors, wavelength, and turbulence intensity on the system’s bit error rate (BER) performance. Additionally, we compare the waveform graphs and amplitude–frequency characteristics of FTN signals before and after processing, specifically comparing sampled values of four-pulse-amplitude modulation (4PAM) signals with those obtained after ISI cancellation. The simulation results demonstrate that within the Mazo limit for selecting acceleration factors, our proposal achieves a 7 dB improvement in BER compared to the conventional systems without deep learning (DL)-based ISI cancellation algorithms. Furthermore, compared to systems employing a point-by-point elimination adaptive pre-equalization algorithm, our proposal exhibits comparable BER performance to orthogonal transmission systems while reducing computational complexity by 31.15%.

Research on the laser melting coating process of an AlCoCrFeNi high‐entropy alloy

AbstractLaser cladding technology is an advanced surface modification technique that has gained significant attention in various fields due to its energy savings, efficiency, and environmental friendliness. This paper discusses the preparation of AlCoCrFeNi high‐entropy alloy (HEA) coatings on the surface of a 5083 aluminum alloy using laser cladding technology under the Ar gas conditions. An orthogonal test system was used to optimize the laser cladding process parameters. The microstructure, as well as the mechanical, frictional, and electrochemical properties of the HEA coatings, were comparatively analyzed under the two process conditions S4 and S10. The results indicate that, under S10, the HEA coatings exhibit optimal surface quality. The coatings contained a mixture of Face‐centered cubic (FCC) and Body‐centered cubic (BCC) phases. Microscopic examination revealed three distinct areas: dark, gray, and off‐white. The coatings can significantly improve the wear and corrosion resistance of the alloy substrate. For the best results, it is set the laser power to 200 W, the laser scanning distance to .05 mm, and the laser scanning rate to 1250 mm/s. This present study offers a novel technical foundation for the fabrication of HEA coatings.

Performance Analysis of Multiple-Input Multiple-Output Orthogonal Frequency Division Multiplexing System using Arithmetic Optimization Algorithm

This research aims to optimize the interference mitigation and improve system performance metrics, such as bit error rates, inter-carrier interference (ICI), and inter-symbol interference (ISI), by integrating the Redundant Discrete Wavelet Transform (RDWT) with the Arithmetic Optimization Algorithm (AOA). This will increase the spectral efficiency of MIMO-OFDM systems for ultra-high data rate (UHDR) transmission in 5G networks. The most important contribution of this study is the innovative combination of RDWT and AOA, which effectively addresses the down sampling issues in DWT-OFDM systems and significantly improves both error rates and data rates in high-speed wireless communication. Fifth-generation wireless networks require transmission at ultra-high data rates, which necessitates reducing ISI and ICI. Multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) is employed to achieve the UHDR. The bandwidth and orthogonality of DWT-OFDM (discrete wavelet transform-based OFDM) are increased; however system performance is degraded due to down sampling. The redundant discrete wavelet transform (RDWT) is proposed for eliminating down sampling complexities. Simulation results demonstrate that RDWT effectively lowers bit error rates, ICI, and ISI by increasing the carrier-to-interference power ratio (CIR). The Arithmetic Optimization Algorithm is used to optimize ICI cancellation weights, further enhancing spectrum efficiency. The proposed method is executed in MATLAB and achieves notable performance gains: up to 82.95% lower error rates and 39.88% higher data rates compared to the existing methods. Conclusion: The integration of RDWT with AOA represents a significant advancement in enhancing the spectral efficiency of MIMO-OFDM systems for UHDR transmission in 5G networks. The proposed method not only enhances system performance but also lays a foundation for future developments in high-speed wireless communication by addressing down sampling issues and optimizing interference mitigation.

Unsupervised detection and mapping of sparks in the Electrochemical Discharge Machining (ECDM) process

Material removal in electrochemical discharge machining is caused by sparks generated in a tool immersed in an electrolytic solution. Being the primary machining agent in this non-contact machining process, mapping the locations of microscopic sparks is of great interest. The distribution of sparks around the tool surface could give insights into the machined hole properties like the size, surface finish, and depth as compared to the machining parameters such as applied voltage, tool size, rotation speed, and feed rate. This paper is focused on detecting sparks in photographs of the ECDM process captured using a high-speed camera. A novel approach of using a tri-planar reflective surface for capturing the location of sparks in 3D space using a 2D camera output is attempted. Traditional spark detection methods use neural network classifiers that need labeled data for training. This labeled data often comes from human intervention and contains inherent biases that could lead to misclassification. In this paper, an unsupervised spark detection methodology is demonstrated, which eliminates the need for human intervention and relies on the number of neighboring pixels detected in regions of interest (ROIs). The feasibility of using adaptive background modeling to classify thousands of images and identify the ones with sparks is demonstrated in this work. The masking technique combining effects of erosion followed by dilation is used to determine the exact boundaries of the spark contours in every image. Centroids for each of these contours are then transformed from the skewed coordinate system as observed in camera images, to a three-dimensional orthogonal coordinates system centered around the tool. The same procedure is repeated for various voltages to benchmark the distribution of sparks around a tool tip in an ECDM process.

Dynamic Response Analysis of Asphalt Pavement under Pavement-Unevenness Excitation

This paper investigates and analyzes the dynamic response of asphalt pavement under pavement-unevenness excitation based on an orthogonal vector function system and efficient DVP (dual variable and position) method. Firstly, starting from the pavement unevenness of the vehicle excitation source, the pavement-unevenness excitation is established by using the filtered white-noise method, and the random load of the vehicle model is obtained by simulation. Then, based on the basic governing equation of the road-surface problem under the random load, the analytical solution of the road-surface mechanical response is obtained by using the orthogonal vector function system and DVP method. The effects of pavement-unevenness grade, vehicle speed, vehicle load, interlayer contact condition, and transverse isotropy on the mechanical response of the road surface are analyzed via the analytical results. The results show that DVP can effectively solve the dynamic response of pavements under the excitation of pavement unevenness; in addition, it can also be applied to certain situations, such as transverse isotropy of materials and interface conditions. The results show that the pavement unevenness does not affect the average stress and strain of each layer but has a significant effect on the peak value and dispersion degree. An increase in vehicle speed causes a peak in strain and a larger coefficient of variation. Poor bonding between interfaces can lead to increased stress and strain at the bottom of the surface layer.

Directed evolution of an orthogonal transcription engine for programmable gene expression in eukaryotes.

T7 RNA polymerase has enabled orthogonal control of gene expression and recombinant protein production across diverse prokaryotic host chassis organisms for decades. However, the absence of 5' methyl guanosine caps on T7 RNAP derived transcripts has severely limited its utility and widespread adoption in eukaryotic systems. To address this shortcoming, we evolved a fusion enzyme combining T7 RNAP with the single subunit capping enzyme from African swine fever virus using Saccharomyces cerevisiae. We isolated highly active variants of this fusion enzyme, which exhibited roughly two orders of magnitude higher protein expression compared to the wild-type enzyme. We demonstrate the programmable control of gene expression using T7 RNAP-based genetic circuits in yeast and validate enhanced performance of these engineered variants in mammalian cells. This study presents a robust, orthogonal gene regulatory system applicable across diverse eukaryotic hosts, enhancing the versatility and efficiency of synthetic biology applications.

AARS1 and AARS2 sense L-lactate to regulate cGAS as global lysine lactyltransferases.

L-lactate modifies proteins through lactylation1, but how this process occurs is unclear. Here we identify the alanyl-tRNA synthetases AARS1 and AARS2 (AARS1/2) as intracellular L-lactate sensors required for L-lactate to stimulate the lysine lactylome in cells. AARS1/2 and the evolutionarily conserved Escherichia coli orthologue AlaRS bind to L-lactate with micromolar affinity and they directly catalyse L-lactate for ATP-dependent lactylation on the lysine acceptor end. In response to L-lactate, AARS2 associates with cyclic GMP-AMP synthase (cGAS) and mediates its lactylation and inactivation in cells and in mice. By establishing a genetic code expansion orthogonal system for lactyl-lysine incorporation, we demonstrate that the presence of a lactyl moiety at a specific cGAS amino-terminal site abolishes cGAS liquid-like phase separation and DNA sensing in vitro and in vivo. A lactyl mimetic knock-in inhibits cGAS, whereas a lactyl-resistant knock-in protects mice against innate immune evasion induced through high levels of L-lactate. MCT1 blockade inhibits cGAS lactylation in stressed mice and restores innate immune surveillance, which in turn antagonizes viral replication. Thus, AARS1/2 are conserved intracellular L-lactate sensors and have an essential role as lactyltransferases. Moreover, a chemical reaction process of lactylation targets and inactivates cGAS.

Numerical analysis of fractional‐order Euler–Bernoulli beam model under composite model

The primary objective of this study is to develop a new constitutive model by combining a fractional‐order Kelvin–Voigt model with an Abel dashpot element in parallel. Subsequently, this new model will be incorporated into the Euler–Bernoulli beam's governing equation, utilizing shifted Legendre polynomials as basis functions, a classical orthogonal polynomial system, to solve the fractional‐order partial differential equations. By comparing the numerical solutions with the analytical solutions, we aim to evaluate the applicability of shifted Legendre polynomials in solving such problems and the accuracy of the obtained numerical solutions. Furthermore, we will investigate the performance of viscoelastic HDPE beams under different loading conditions and conduct a comparative analysis of the displacements of HDPE beams under the new constitutive model and the traditional fractional‐order Kelvin–Voigt model. Through this research, we hope to gain a deeper understanding of the characteristics of fractional‐order phenomena and provide more accurate and efficient numerical simulation and analysis methods for the field of structural mechanics, promoting the development of related engineering applications.

Pfadunabhängiges mit sichtbarem Licht adressierbares orthogonales Photoschalten für Anwendungen in multi‐photochromomen Polymeren und molekularen Computern

AbstractSynthetische molekulare Photoschalter sind als hochpräzise Werkzeuge zur Einführung von Lichtadressierbarkeit auf kleinster Ebene in den Mittelpunkt der Forschung gerückt. Heute sind sie in allen Bereichen der angewandten Chemie zu finden, sei es in der Materialforschung, chemischen Biologie, Katalyse oder Nanotechnologie. Für einen nächsten Schritt in der Anwendbarkeit ist vollständig orthogonales Photoschalten besonders wünschenswert, aber bis heute ist eine solche unabhängige Adressierbarkeit verschiedener Photoschalter eine große Herausforderung. In dieser Arbeit präsentieren wir das erste Beispiel für ein vollständig durch sichtbares Licht adressierbares und pfadunabhängiges orthogonales Photoschalten. Durch die Kombination von zwei kürzlich entwickelten indigoiden Photoschaltern – ein peri‐Anthracenthioindigo und ein auf Rhodanin‐basiertes Chromophor – wird ein Schaltsystem mit vier Zuständen geschaffen, wobei jeder Zustand in hoher Ausbeute völlig unabhängig und ausnahmslos mit sichtbarem Licht angesteuert werden kann. Die vier Zustände führen zu vier verschiedenen Farben, die auf eine feste Polymermatrix übertragen werden können, wodurch ein vielseitiges photochromes Material mit multiplen Zuständen entsteht. Darüber hinaus wird die Kombination mit einem Fluoreszenzfarbstoff als dritter Komponente gezeigt, was die Anwendbarkeit dieses orthogonalen Photoschaltersystems in der molekularen Logik und Informationsverarbeitung ermöglicht.

Path-Independent All-Visible Orthogonal Photoswitching for Applications in Multi-Photochromic Polymers and Molecular Computing.

Synthetic molecular photoswitches have taken center stage as high-precision tools to introduce light-responsiveness at the smallest scales. Today they are found in all areas of applied chemistry, covering materials research, chemical biology, catalysis, or nanotechnology. For a next step of applicability truly orthogonal photoswitching is highly desirable but to date such independent addressability of different photoswitches remains to be highly challenging. In this work we present the first example of all-visible, all-light responsive, and path independent orthogonal photoswitching. By combining two recently developed indigoid photoswitches -peri-anthracenethioindigo and a rhodanine-based chromophore - a four-state system is established and each state can be accessed in high yields completely independently and also with visible light irradiation only. The four states give rise to four different colors, which can be transferred to a solid polymer matrix yielding a versatile multi-state photochromic material. Further, combination with a fluorescent dye as third component is possible, demonstrating applicability of this orthogonal photoswitching system in all-photonic molecular logic behavior and information processing.

Insights into phosphoethanolamine cellulose synthesis and secretion across the Gram-negative cell envelope

Phosphoethanolamine (pEtN) cellulose is a naturally occurring modified cellulose produced by several Enterobacteriaceae. The minimal components of the E. coli cellulose synthase complex include the catalytically active BcsA enzyme, a hexameric semicircle of the periplasmic BcsB protein, and the outer membrane (OM)-integrated BcsC subunit containing periplasmic tetratricopeptide repeats (TPR). Additional subunits include BcsG, a membrane-anchored periplasmic pEtN transferase associated with BcsA, and BcsZ, a periplasmic cellulase of unknown biological function. While cellulose synthesis and translocation by BcsA are well described, little is known about its pEtN modification and translocation across the cell envelope. We show that the N-terminal cytosolic domain of BcsA positions three BcsG copies near the nascent cellulose polymer. Further, the semicircle’s terminal BcsB subunit tethers the N-terminus of a single BcsC protein in a trans-envelope secretion system. BcsC’s TPR motifs bind a putative cello-oligosaccharide near the entrance to its OM pore. Additionally, we show that only the hydrolytic activity of BcsZ but not the subunit itself is necessary for cellulose secretion, suggesting a secretion mechanism based on enzymatic removal of translocation incompetent cellulose. Lastly, protein engineering introduces cellulose pEtN modification in orthogonal cellulose biosynthetic systems. These findings advance our understanding of pEtN cellulose modification and secretion.

Physical interpretation of invariance of vector differential operators in three orthogonal coordinate systems and a case study of wall and globe of death

In the present study, the effect of operators on fundamental physical quantities in three orthogonal coordinate systems was analyzed using differential equations. The mathematical expression for the position vector and its magnitude, velocity, &acceleration in three orthogonal coordinate systems were obtained from the geometry of the figure and differentiation. The derivations of operation of vector differential operators (curl and diversions) on position vectors were derived, and their physical significance was illustrated. Similarly, the operation of the Laplacian operator on the magnitude of the position vector was also studied. The study highlighted the invariance in the results of all operations in three orthogonal coordinate systems. An investigation has been performed to describe the wall of death and the globe of death problem in appropriate orthogonal coordinate systems. The interpretations in terms of velocity, acceleration, and the net force acting on the vehicle are explained in detail.

Rheological analysis of pressure-driven Jeffrey fluid flow between corrugated porous curved walls with slip constraints

Pressure-driven movement is a fundamental concept with numerous applications in various industries, scientific disciplines, and fields of engineering. Its proper execution is vital for promoting revolutionary innovations and providing solutions in numerous sectors. Therefore, this article scrutinizes the pressure-driven flow of a magnetized Jeffrey fluid between two curved corrugated walls. The geometry of the channel is represented mathematically in an orthogonal curvilinear coordinate system. The corrugation grooves are described by sinusoidal functions with phase differences between the corrugated curved walls. The boundary perturbation method is used to find the analytical solution for the velocity and temperature taking the corrugation amplitude as the perturbation parameter. Furthermore, the volumetric flow rate, skin friction coefficient, and local Nusselt numbers are precisely calculated numerically for a variety of parameters, with the results presented comprehensively in tabular form. The impact of dissimilar parameters, such as the curvature parameter, wave number, magnetic parameter, Darcy number, thermal radiation, heat source/sink parameter, Jeffery fluid parameter, and amplitude parameter, on the flow fields is analyzed through graphical and tabular forms and discussed in detail. The results show that the velocity profile increases due to the curvature parameter and the Jeffrey fluid parameter. However, it decreases due to the magnetic parameter. The temperature distribution rises with the thermal slip and heat source/sink parameters. Meanwhile, it declined for the radiation parameter and the curvature parameter. The model can be used to simulate blood flow in arteries with varying geometries and magnetic fields, aiding in the study of cardiovascular diseases and the design of medical devices such as stents.

Rheological study of water-based Cu nanofluid between two corrugated curved walls under constant pressure gradient

Nanofluids have captured the attention of scientists due to their superior thermophysical properties compared to ordinary liquids. Consequently, nanofluids serve as suitable cooling agents applicable to systems requiring swift response to thermal changes, such as vehicle engines. Therefore, the current article scrutinizes the characteristics of heat transfer on the pressure-driven flow of magnetized nanofluid between two curved corrugated surfaces in the presence of heat generation/absorption. Copper oxide nanoparticles (Cu) have been combined with pure water to form a nanofluid called Cu/H2O. The geometry of the channel is represented mathematically in an orthogonal curvilinear coordinate system. The corrugation grooves are described by sinusoidal functions with phase differences between the corrugated curved walls. The boundary perturbation method is used to find the analytical solution for the velocity field, temperature field, and volumetric flow rate taking the corrugation amplitude as the perturbation parameter. The impact of dissimilar parameters such as the curvature parameter (0.5≤k≤10), wave number (1≤α≤3), magnetic parameter (1≤M≤5), and wave amplitude (0.1≤ε≤0.8) on the flow fields are analyzed through graphs and discussed in detail. The results show that the peak of the velocity increases with the radius of curvature and the width of the channel for a constant pressure gradient. If we increase the magnetic parameter from 1 to 4, the velocity profile at the specified point decreases by 30 %. If we increase the heat source/sink parameter from 2 to 5, the temperature profile at the specified point increases by approximately 17 %. The flow rate is increased by the corrugations for any phase difference between the corrugated curved walls depending on the corrugation wavenumber and the channel radius of curvature.