Number Of Rays Research Articles

Early development of smallscale weakfish Cynoscion microlepidotus (Cuvier, 1830) (Sciaenidae: Teleostei).

Larval and transforming stages of smallscale weakfish Cynoscion microlepidotus (Sciaenidae) are described and illustrated based on samples obtained in three different sites along the Brazilian coast: São Marcos Bay (Maranhão state), Camamu Bay (Bahia state), and the Cananéia-Iguape Estuarine System (São Paulo state). Identification of early stages of C. microlepidotus was based on meristic counts, such as number of myomeres (22), number of fin spines and rays (dorsal XI, 24, anal II, 9 and pectoral 19), morphological features (presence of supraoccipital crest in larvae from flexion to transformation stages, branched anal fin spines) and pigmentation pattern. Early stages of this species are likely to be confused with Carangidae and Scorpaenidae due to the presence of a supraoccipital crest, and with the Sciaenidae species Stellifer rastrifer, Macrodon atricauda, M. ancylodon, and Isopistus parvipinnis due to branched anal fin elements. However, a distinction can be made when analyzing the set of characters (morphology, morphometry, pigmentation) in relation to the different stages of development.

Intraspecific variation of <em>Scorpaenopsis possi</em> Randall et Eschmeyer, 2002 (Pisces: Scorpaenidae)

The genus Scorpaenopsis has been intensively studied in recent decades. Sixteen species were known before the revision by Randall and Eschmeyer, who described 8 new species in 2002, and nowadays 29 species are known. Two specimens of Scorpaenopsis from the collection of the Zoological Institute of the Russian Academy of Sciences are intermediate in a number of parameters between Scorpaenopsis possi Randall et Eschmeyer 2002 and Scorpaenopsis eschmeyeri Randall et Greenfield 2004. The range of S. possi extends from the Indian Ocean coast of Africa and the Red Sea to the Marquesas Islands in the Pacific Ocean, the latitude of the range lies between the 30th latitudes of both hemispheres. The species S. eschmeyeri inhabits a much smaller range from the east coast of Australia to the island of Fiji. The aim of this work is to explain the appearance of S. possi, similar to S. eschmeyeri in some morphological diagnostic characters, almost 12,000 km apart from its range. The number of soft rays in the dorsal fin, which is unusual for the genus Scorpaenopsis, is described. Due to the lack of persistent distinguishing characters between S. possi and S. eschmeyeri, it is highly probable that both are conspecific; in that case S. eschmeyeri would be a junior synonym of S. possi.

Investigations on Millimeter-Wave Indoor Channel Simulations for 5G Networks

Due to the extensively accessible bandwidth of many tens of GHz, millimeter-wave (mmWave) and sub-terahertz (THz) frequencies are anticipated to play a significant role in 5G and 6G wireless networks and beyond. This paper presents investigations on mmWave bands within the indoor environment based on extensive simulations; the study considers the behavior of the omnidirectional and directional propagation characteristics, including path loss exponents (PLE) delay spread (DS), the number of clusters, and the number of rays per cluster at different frequencies (28 GHz, 39 GHz, 60 GHz and 73 GHz) in both line-of-sight (LOS) and non-LOS (NLOS) propagation scenarios. This study finds that the PLE and DS show dependency on frequency; it was also found that, in NLOS scenarios, the number of clusters follows a Poisson distribution, while, in LOS, it follows a decaying exponential distribution. This study enhances understanding of the indoor channel behavior at different frequency bands within the same environment, as many research papers focus on single or two bands; this paper considers four frequency bands. The simulation is important as it provides insights into omnidirectional channel behavior at different frequencies, essential for indoor channel planning.

Taxonomy of freshwater gobies of the genus Rhinogobius (Oxudercidae, Gobiiformes) from central Vietnam, with descriptions of two new species

Taxonomy of the genus Rhinogobius was investigated for the first time in Central Vietnam. Five species occurring in this region can be distinguished by shape of their head, number of pectoral-fin rays, vertebral counts, arrangements of scales and cutaneous sensory papillae, and coloration. Two species are described as new, Rhinogobius rong sp. nov. and R. nami sp. nov., and the remaining three were identified as R. taenigena, R. leavelli, and R. similis. Though the morphology of R. leavelli and R. similis differed slightly between localities, counts and measurements overlapped, and coloration was variable. This study tentatively identifies all of those populations as R. leavelli or R. similis, but further research using additional specimens from a wider geographic range is required to clear the identity of the Rhinogobius occurring in this region. Rhinogobius rong, R. similis, and R. leavelli are distributed in both Da Nang City and Thua Thien Hue Province, with the first two species occurring widely in coastal areas, and R. leavelli restricted to inland areas. On the other hand, Rhinogobius nami and R. taenigena occur only in inland areas of Da Nang City and Thua Thien Hue Province, respectively.

Molecular phylogeny and taxonomic review of the family Pomacentridae from Korea

A total of eight genera and 21 species of the family Pomacentridae have been reported in Korea, but the classification is uncertain. Therefore, this study aims to clarify molecular phylogeny and classification of eight genera and 17 species of the family Pomacentridae from Korea based on mtDNA sequences (16S rRNA 473 bp), nDNA sequences (RAG1 812 bp) and morphological traits. Molecular phylogenetic trees (ML, and BI) showed that four groups (Chrominae, Glyphisodontinae, Pomacentrinae, and Microspathodontinae) were largely formed, and monophyletic relationship was observed four groups. Each subfamily is divided by the number of spiniform procurrent caudal rays, the shape and rows of the teeth, and the margin of suborbital and preopercle. Each genus is divided by the number of dorsal fin spines and anal fin soft rays, the shape and rows of the teeth, and body coloration. Through an extensive examination of pomacentrids specimens loaned from museum or universities, it is believed that Chromis analis, Neopomacentrus violascens and Pomacentrus chrysurus are not distributed in Korea in spite of their previous records. Finally, we provide key to the species of the family Pomacentridae from Korea.

Adult caudal fin shape is imprinted in the embryonic fin fold.

Appendage shape is formed during development (and re-formed during regeneration) according to spatial and temporal cues that orchestrate local cellular morphogenesis. The caudal fin is the primary appendage used for propulsion in most fish species, and exhibits a range of distinct morphologies adapted for different swimming strategies, however the molecular mechanisms responsible for generating these diverse shapes remain mostly unknown. In zebrafish, caudal fins display a forked shape, with longer supportive bony rays at the periphery and shortest rays at the center. Here, we show that a premature, transient pulse of sonic hedgehog a (shha) overexpression during late embryonic development results in excess proliferation and growth of the central rays, causing the adult caudal fin to grow into a triangular, truncate shape. Both global and regional ectopic shha overexpression are sufficient to alter fin shape, and forked shape may be rescued by subsequent treatment with an antagonist of the canonical Shh pathway. The induced truncate fins show a decreased fin ray number and fail to form the hypural diastema that normally separates the dorsal and ventral fin lobes. While forked fins regenerate their original forked morphology, truncate fins regenerate truncate, suggesting that positional memory of the fin rays can be permanently altered by a transient treatment during embryogenesis. Ray finned fish have evolved a wide spectrum of caudal fin morphologies, ranging from truncate to forked, and the current work offers insights into the developmental mechanisms that may underlie this shape diversity.

The Modeling of Concentrators for Solar Photovoltaic Systems

Concentrating photovoltaic (CPV) systems have emerged as a transformative technology that incorporates radiation concentrators into the photovoltaic system to enable radiation to be concentrated onto a receiver—the solar cells. Different concentrator configurations have different impacts on the performance of the solar photovoltaic system. This research work aims to analyze the impact of different concentrators, comparing and identifying the most efficient structures for capturing and concentrating solar energy. Aiming at a deep analysis and comparison among concentrators shapes, this research work presents a unique investigation and revision among different structures such as flat, triangular, LFR, and parabolic concentrators. Moreover, since, in the UV–visible–NIR region, metals’ reflectance varies with the incident wavelength, five metals were considered: aluminum, gold, platinum, copper, and silver. Additionally, the research focuses on studying the effects of parameters critical to the quality of the concentration on the power obtained and on the uniformity of the radiation distribution on the surface of the receiver, as well as on the number of solar rays that reach the receiver. The power on the receiver increases proportionally with the number of reflector concentrators in the system and their reflectance. For parabolic geometries, the optical efficiency is affected by the receiver’s shadow on the concentrator and, in the case of the LFR, by a non-ideal alignment of the reflectors in relation to the receiver. However, in parabolic concentrator geometries, uniformity is usually lower, since in these configurations, the radiation is focused on specific areas of the receiver, usually the central zone.

Bupleurum milamense sp. nov. (Apiaceae) from Milam Valley, Western Himalaya, India

A new species, Bupleurum milamense (Apiaceae) is described from the alpine forest region of the Milam Valley, Uttarakhand, India. The new species is similar to B. gracillimum Klotzsch in the nature of the plant, leaf shape, number of bracts, shorter umbel rays, number, shape and size of bracteoles, bracteoles shorter than the flowers, and number of flowers per umbellules, However, it significantly differs by having an erect stem position, in the number of umbel rays, fruit shape and size, and number of vallecular and commissural vittae. A detailed description, photographs, distribution map, and a comparison with allied species are provided.

Discovery of a ribbon goby, Oxymetopon compressus (Actinopterygii: Gobiiformes: Microdesmidae) in Indian waters: A new westernmost record for the genus Oxymetopon

In October 2023, a single specimen of Oxymetopon compressus Chan, 1966 was retrieved from a discarded catch at the Mudasal Odai fish landing center on the southeast coast of India. This study marks the first record of the genus Oxymetopon in Indian waters, accompanied by a novel maximum length record. Oxymetopon compressus, closely resembles its congener, Oxymetopon formosum Fourmanoir, 1967 in having low supraorbital crest and head markings, but differs in having relatively a higher number of anal fin rays, 29 (vs. 27 in O. formosum). The anal fin count of O. compressus (29) is found higher than the Oxymetopon curticauda Prokofiev, 2016 (21–23) and Oxymetopon filamentosum Fourmanoir, 1967 (26), whereas it is found lower than the Oxymetopon cyanoctenosum Klausewitz et Condé, 1981 and Oxymetopon typus Bleeker, 1861 (31). This study describes the distinctive morphological and coloration patterns of the recorded species.

Protocol optimization for functional cardiac CT imaging using noise emulation in the raw data domain.

Four-dimensional (4D) wide coverage computed tomography (CT) is an effective imaging modality for measuring the mechanical function of the myocardium. However, repeated CT measurement across a number of heartbeats is still a concern. A projection-domain noise emulation method is presented to generate accurate low-dose (mA modulated) 4D cardiac CT scans from high-dose scans, enabling protocol optimization to deliver sufficient image quality for functional cardiac analysis while using a dose level that is as low as reasonably achievable (ALARA). Given a targeted low-dose mA modulation curve, the proposed noise emulation method injects both quantum and electronic noise of proper magnitude and correlation to the high-dose data in projection domain. A spatially varying (i.e., channel-dependent) detector gain term as well as its calibration method were proposed to further improve the noise emulation accuracy. To determine the ALARA dose threshold, a straightforward projection domain image quality (IQ) metric was proposed that is based on the number of projection rays that do not fall under the non-linear region of the detector response. Experiments were performed to validate the noise emulation method with both phantom and clinical data in terms of visual similarity, contrast-to-noise ratio (CNR), and noise-power spectrum (NPS). For both phantom and clinical data, the low-dose emulated images exhibited similar noise magnitude (CNR difference within 2%), artifacts, and texture to that of the real low-dose images. The proposed channel-dependent detector gain term resulted in additional increase in emulation accuracy. Using the proposed IQ metric, recommended kVp and mA settings were calculated for low dose 4D Cardiac CT acquisitions for patients of different sizes. A detailed method to estimate system-dependent parameters for a raw-data based low dose emulation framework was described. The method produced realistic noise levels, artifacts, and texture with phantom and clinical studies. The proposed low-dose emulation method can be used to prospectively select patient-specific minimal-dose protocols for functional cardiac CT.

Simulation of Temperature Field in Steel Billets during Reheating in Pusher-Type Furnace by Meshless Method

Using a meshless method, a simulation of steel billets in a pusher-type reheating furnace is carried out for the first time. The simulation represents an affordable way to replace the measurements. The heat transfer from the billets with convection and radiation is considered. Inside each of the billets, the heat diffusion equation is solved on a two-dimensional central slice of the billet. The diffusion equation is solved in a strong form by the Local Radial Basis Function Collocation Method (LRBFCM) with explicit time-stepping. The ray tracing procedure solves the radiation, where the view factors are computed with the Monte Carlo method. The changing number of billets in the furnace at the start and the end of the loading and unloading of the furnace is considered. A sensitivity study on billets’ temperature evolution is performed as a function of a different number of rays used in the Monte Carlo method, different stopping times of the billets in the furnace, and different spacing between the billets. The temperature field simulation is also essential for automatically optimizing the furnace’s productivity, energy consumption, and the billet’s quality. For the first time, the LRBFCM is successfully demonstrated for solving such a complex industrial problem.

Increasing the species diversity of the monotypic genus Pariolius Cope 1872 (Siluriformes: Heptapteridae) after more than 150 years

Pariolius is a heptapterid genus represented by P. armillatus that is distributed along the upper Amazon River basin. A taxonomic integrative revision of Pariolius from Colombian Rivers revealed two new species. Several approaches as morphological, morphometric, meristic, osteology and molecular data were used to distinguish between Pariolius species. The two new species are distinguished from congeners by the caudal-fin shape and numbers of rays, colorations patterns and several morphometric characters. The two new species of Pariolius are restricted to tributaries of the Upper Orinoco and Upper Negro rivers in Colombia.

Tropical mobola plum (Parinari Curatellifolia): a full characterization of wood and bark within the scope of biorefineries

Parinari curatellifolia is the main species used to produce charcoal in Angola. Its chemical, anatomical, and thermal properties were analyzed. The bark is dark grey, rough, and corky, and the wood is brown to yellow-red. Compared to wood, bark fibers presented lower length, lumen, and wall thickness. There is not much difference between height and cell numbers of rays. Sieve tube elements appear solitary or in small groups (2–3 cells), and vessels were of two diameter classes but diffuse-porous. Bark basic density was lower than wood (505 kg.m− 3vs. 580 kg.m− 3). The mean chemical composition from bark vs. wood of P. curatellifolia was ash (3.2% vs. 1.6%), total extractives (12.2% vs. 10.0%), total lignin (42.4% vs. 28.4%), and suberin 5.4%. Families identified by GC-MS from DCM extracts were predominated by fatty acids in wood and triterpenoid contents in bark. Bark and wood had higher antioxidant activity in FRAP and DPPH methods. The bark had a monomeric lignin composition richer in guaiacyl-units (25.9% vs. 22.5%) and lower syringyl-units (5.7% vs. 8.5%). Potassium was the most abundant mineral, while the least was cadmium found in wood and bark. Regarding thermal properties, bark presented higher moisture content (9.0% vs. 8.0%), ash (3.33% vs. 1.61%), total volatiles (27.5% vs. 20.7%), lower fixed carbon (69.1% vs. 77.7%) and higher heating value (20.9 MJ/kg vs. 19.1 MJ/kg). According to these characteristics, both biomasses are interesting for developing more value-added products (e.g., charcoal, bio-chemicals with phytochemistry and pharmacology activities) besides burning under the context of biorefineries.

Communication channel parameters estimation using a ray tracing model in heterogeneous networks

Currently, modern networks LTE, Wi-Fi, 5GNR are combined into a single heterogeneous network, which leads to an increase in intra-system interference. According to the integrated optimization method, to distribute data flows in a heterogeneous network, taking into account the intra-system interference influence, the collective dynamic routing method is used. At the analysis stage of this method it is necessary to estimate the channel data rate in all valid routes. To obtain correct channel data rates estimates, it is necessary to reliably estimate the channel matrix. Today, the ray tracing model is widely used to estimate the channel matrix. The verification results of the using ray tracing model given in [1] show the need for additional research to increase the channel matrix estimates reliability. Therefore increasing the reliability of channel matrix transmission coefficients estimates by analyzing the influence of the number of rays taken into account is the actual task. The work analyzes the influence of the number of rays taken into account on the reliability of estimating the complex transmission coefficients of the channel matrix for the cases of the presence and absence of line of sight be-tween the transmitter and the receiver. Expressions are obtained to take into account the influence of diffracted, singly reflected and passed through an obstacle rays. A program has been developed to find all possible rays arriving at the receiver location point and determine their parameters based on a digital 3D map indicating the map objects materials. Using the developed program, it is shown that taking into account the influence of additional rays makes it possible to increase the channel matrix estimation reliability, and therefore, the modified ray tracing model can be used to estimate channel data rates when applying the collective dynamic routing method in heterogeneous net-works.

HeLiPR: Heterogeneous LiDAR dataset for inter-LiDAR place recognition under spatiotemporal variations

Place recognition is crucial for robot localization and loop closure in simultaneous localization and mapping (SLAM). Light Detection and Ranging (LiDAR), known for its robust sensing capabilities and measurement consistency even in varying illumination conditions, has become pivotal in various fields, surpassing traditional imaging sensors in certain applications. Among various types of LiDAR, spinning LiDARs are widely used, while non-repetitive scanning patterns have recently been utilized in robotics applications. Some LiDARs provide additional measurements such as reflectivity, Near Infrared (NIR), and velocity from Frequency modulated continuous wave (FMCW) LiDARs. Despite these advances, there is a lack of comprehensive datasets reflecting the broad spectrum of LiDAR configurations for place recognition. To tackle this issue, our paper proposes the HeLiPR dataset, curated especially for place recognition with heterogeneous LiDARs, embodying spatiotemporal variations. To the best of our knowledge, the HeLiPR dataset is the first heterogeneous LiDAR dataset supporting inter-LiDAR place recognition with both non-repetitive and spinning LiDARs, accommodating different field of view (FOV)s and varying numbers of rays. The dataset covers diverse environments, from urban cityscapes to high-dynamic freeways, over a month, enhancing adaptability and robustness across scenarios. Notably, HeLiPR dataset includes trajectories parallel to MulRan sequences, making it valuable for research in heterogeneous LiDAR place recognition and long-term studies. The dataset is accessible at https://sites.google.com/view/heliprdataset.

Anatomical Study for Wood Identification of Shorea Species in Sri Lanka

Wood anatomy is a rapid method for identifying different timber species. Shorea is a diverse genus of trees in the subfamily Dipterocarpaceae and encompasses a group of some 470 tree species that dominate much of the tropical forests of South and Southeast Asia. Many of these are valued commercially for their hardwoods. However, the anatomical identification of Shorea sp. in Sri Lanka has not been fully studied yet. Six Shorea species available in the lowland wet agroecological zone in Ratnapura District, in Sri Lanka, were selected for this study. The study was conducted in the wood Science laboratory of the State Timber Corporation, Sri Lanka. Six Shorea species, including Beraliya dun (S. disticha), Navada dun (S. stupularis), Dun (S. zeylanica), Yakahalu dun (S. trapezifolia), Yakal dun (S. astylosa) and Thiniya dun (S. congestiflora) were used to identify the variation of wood anatomical features to differentiate the species. As a reference, the Publication List of the International Association of Wood Anatomists on anatomical characteristics was used. To determine the microscopic features, six wood sections (Radial, Tangential, and Transverse sections of the wood) representing each species were employed. The anatomical characteristics of the timber were examined using Micrometrics SE Premium 4 software. According to the results, Yakahal Dun species showed the highest number of vessels and Navada represented the lowest number of vessels. The highest value for the vessel diameter showed the Thiniya species and the lowest for the Dun. Beraliya species showed the highest no of rays and the lowest number of rays showed in Yakahalu dun. A Dichotomous key was developed for the exact identification of Shorea species based on the anatomical characteristics.
 
 Keywords: Dichotomous key, IAWA features, Identification, Shore sp., Wood anatomy

Optimal parameters of Monte Carlo ray tracing solver with line-by-line spectral database for radiation modeling in fire

Thermal radiation is an important heat transfer mechanism in fire, but its modeling has often been over-simplified due to computational expense. In this study, we assess whether the Monte Carlo ray tracing (MCRT) method using the line-by-line (LBL) spectral database can serve as a fast and accurate candidate for solving radiation in fire. Using a snapshot extracted from a previous well-resolved simulation of a small turbulent pool fire, the radiation field is solved using a recently developed MCRT-LBL solver with three varying parameters: the number of rays per computational cell, the energy emission scheme, and the resolution of the LBL database. The energy equation is subsequently solved for one time step to assess the propagation of statistical noise into the temperature field. The radiative absorption is well predicted even with only one ray emitted per cell. Adaptive emission, where more rays are emitted at locations with stronger volumetric radiative emission, converges faster than the standard approach, where the same number of rays are emitted from every cell, although the advantage of the former is only pronounced when a sufficiently large number of rays are emitted. The statistical noise is smoothed in the calculation of the radiative heat source because the radiative emission is always predicted accurately regardless of the solver’s parameters. Further damping is provided by the energy equation, yielding a temperature field with negligible noise. Coarsening the LBL database only marginally affects the accuracy of the results, but it reduces the memory required to store the data to less than 10% of that of the original database. Lastly, when soot dominates radiative emission, the statistical noise of the radiation source is further reduced. In conclusion, the study indicates reasonable feasibility for applying MCRT-LBL in fire modeling, and we will further demonstrate this possibility in future studies using larger fires.

Comparative Microstructural Evaluation of Wood in Three Dominant Ziziphus Species of Desert Ecosystem (Cholistan), Pakistan

The present microstructural evaluation was carried out on the woods of three ethnobotanically important local fruit trees, namely, Ziziphus mauritiana Lam., Z. spina-christi (L.) Willd., and Z. nummularia (Burm.f.) Wight and Arn., of family Rhamnaceae from Cholistan Desert of Pakistan. Wood samples were sectioned with sliding sledge microtome to make permanent slides for observing different anatomical parameters under the light microscope. All selected species were observed to have diffuse‐porous wood with indistinct growth rings. The vessels were rounded in outline in all the species studied and found mostly solitary or in radial multiples of 2 in Ziziphus mauritiana and Z. nummularia, while in radial multiples of 2 to 5 in Z. spina-christi. The intervessel pits were scalariform to opposite. The rays were uniseriate in Ziziphus mauritiana, while mostly were biseriate in Ziziphus spina-christi. Simple perforation plates and diffuse, confluent, and vasicentric types of axial parenchyma were present in all the selected species. The fibers were thin‐walled and nonseptate. One‐way ANOVA followed by the Tukey test was conducted to observe different anatomical variations within selected species. Principal component analysis revealed correlations among studied anatomical parameters. The number of rays per mm was comparatively larger in Ziziphus nummularia, showing its greater susceptibility to wood‐deteriorating agents than in other selected species. The Runkel ratio indicated the selected species suitable for making paper.

Iterative taxonomy reveals a new species of Cambeva (Siluriformes: Trichomycteridae) with intraspecific variation from the rio Piquiri and Ivaí basin, upper rio Paraná basin, Brazil

Abstract A new species of Cambeva occurring in the rio Piquiri and Ivaí, upper rio Paraná basin, Brazil, is described using the combination of morphological and molecular data. The new species is distinguished from most congeners by the presence of a notch in the posterior portion of the metapterygoid, number of branchiostegal rays, opercular and interopercular odontodes, and ribs. In addition, the results corroborated the existence of a single species with wide intraspecific variation in body coloration. The type-locality is within the area of influence of the Perobas Biological Reserve, a Conservation Unit in the Paraná State, composed of two Atlantic Forest physiognomic forms. Considering that the upper rio Paraná basin is an area of significant anthropic influence, it is crucial to describe and preserve species to understand their ichthyofauna.

Ray Tracing and Simulation of Parabolic Dish Collectorusing Soltrace for Vehicle Applications

Concentrated solar power has the potential to produce large-scale renewable energy sources. Concentrated solar energy is produced using mirrors, reflective materials, or lenses on conical surfaces such as a parabolic dishes, parabolic troughs, towers, Fresnel reflector systems, and dish sterling collectors. The concentrated light source was converted into heat energy, which drove the heat engine into an electrical power generator. To gain more heat energy, the solar rays must be trapped and concentrated on their conical focus points. To increase the net overall efficiency of the system, it is vital to know the optical performances of the subsystem formed by the solar receiver and the parabolic concentrator. In this study, a beam of incident solar rays was traced on a parabolic dish collector, and a simulation is performed for concentrator behaviour using the ray-tracing code SolTrace developed by the NREL laboratory. For an incident radiation of 1000 W/m2 (considering 10000 photon rays), their optical performance and solar heat flux were simulated. The results show that the number of elements in SolTrace varies depending on the CFD mesh density, the number of rays utilised in the Monte Carlo technique and their impact on generating a resolution-independent solution. Investigating the ray tracing of the disc concentrator, the propulsive energy for viable applications can be analysed.