Cone Type Research Articles

Numerical and theoretical modeling of water droplet impact on hydrophilic and superhydrophobic cones

The phenomenon of droplet impingement on solid surfaces is prevalent in various natural and industrial contexts. Research on impact dynamics on conical surfaces keeps emerging, with superhydrophobic cones receiving more attention than hydrophilic ones. This study systematically investigates water droplet impact dynamics on both hydrophilic and superhydrophobic cones using a two-phase numerical solver under different Weber numbers (We) and cone angles (φ). Three distinct phases are identified in the We–φ map to describe the different outcomes on each type of cones. Generally, deposition occurs ultimately on hydrophilic cones, whereas rebounding is observed on superhydrophobic ones. The maximum spreading area βAmax on hydrophilic cones depends only slightly on φ but consistently increases with We, following a scaling law of We0.5 at higher We. In contrast, on superhydrophobic cones, βAmax increases significantly with both We and φ, and the exponent in the scaling laws of βAmax with respect to We increases notably as φ increases. Three characteristic times are defined to describe important motion states on both types of cones. Corresponding scaling laws for each time with We are established. Two theoretical models are developed to predict the maximum spreading position for droplets on hydrophilic cones and the rebound position on superhydrophobic cones, respectively. Gravitational potential energy is included in the energy budget for both models, and an auxiliary viscous dissipation due to spontaneous spreading is accounted for the hydrophilic case. Satisfactory agreement between the theoretical and numerical results is achieved.

Variability in oil droplet numbers and proportions in the retinas of anole lizards

Colored oil droplets are a common feature in the cones of almost all diurnal lizards. Using white light microscopy, three chromotypes of droplet can be identified in anoles – yellow, green and colorless. These droplets have been associated with different cone classes using microspectrophotometry. The principal member of double cones contain a yellow droplet while the accessory member contains a diffuse yellow pigment. Both members contain the LWS visual pigment. One class of large single cone contains a yellow droplet and the LWS visual pigment. The two remaining classes of large single cone contain the green droplet and either the LWS or MWS visual pigment. As such, by noting the distribution and numbers of the different droplet chromotypes, information about cone distribution, type, and number can be deduced microscopically. Retinas from three anole species (A. cristatellus, A. sagrei, and A. carolinensis) were isolated, flattened and oriented using the two foveae as landmarks. A 19-gauge needle was used to punch out six full-thickness retinal disks from identical retinal regions from both eyes of the three species. The different oil droplets were microscopically identified by color and counted. In all three species at all six retinal areas, the colorless droplets associated with the UVS and SWS single cones represented approximately 10% of the total droplets counted. However, the proportions of the yellow and green droplets were significantly different between the species. For A. cristatellus, 80% of the droplets were green while 10% were yellow. For A. sagrei approximately 85% of the droplets were yellow while only 5% were green. For A. carolinensis 50% of the droplets were yellow while 40% were green. The possible significance of these variable proportions is discussed in terms of possible effects on color vision and ecotype of the three anoles.

Psychophysics of neon color spreading: Chromatic and temporal factors are not limiting

Neon color spreading (NCS) is an illusory color phenomenon that provides a dramatic example of surface completion and filling-in. Numerous studies have varied both spatial and temporal aspects of the neon-generating stimulus to explore variations in the strength of the effect. Here, we take a novel, parametric, low-level psychophysical approach to studying NCS in two experiments. In Experiment 1, we test the ability of both cone-isolating and equiluminant stimuli to generate neon color spreading for both increments and decrements in cone modulations. As expected, sensitivity was low to S(hort-wavelength) cone stimuli due to their poor spatial resolution, but sensitivity was similar for the other color directions. We show that when these differences in detection sensitivity are accounted for, the particular cone type, and the polarity (increment or decrement), make little difference in generating neon color spreading, with NCS visible at about twice detection threshold level in all cases. In Experiment 2, we use L-cone flicker modulations (reddish and greenish excursions around grey) to study sensitivity to NCS as a function of temporal frequency from 0.5 to 8 Hz. After accounting for detectability, the temporal contrast sensitivity functions for NCS are approximately constant or even increase over the studied frequency range. Therefore there is no evidence in this study that the processes underlying NCS are slower than the low-level processes of simple flicker detection. These results point to relatively fast mechanisms, not slow diffusion processes, as the substrate for NCS.

Vision: A specialized pathway for pigment regeneration in cones

Vision relies on two types of photoreceptor cells, rods and cones. Rods outnumber cones in the retinas of humans and most other vertebrate species, yet the contribution of cones to our vision is far more impactful than rods. A new study reveals an elegant enzymatic mechanism that favors light perception by cones under daylight conditions when rods are saturated by light and contribute little to useful vision.

Cone photoreceptor differentiation regulated by thyroid hormone transporter MCT8 in the retinal pigment epithelium

The key role of a thyroid hormone receptor in determining the maturation and diversity of cone photoreceptors reflects a profound influence of endocrine signaling on the cells that mediate color vision. However, the route by which hormone reaches cones remains enigmatic as cones reside in the retinal photoreceptor layer, shielded by the blood-retina barrier. Using genetic approaches, we report that cone differentiation is regulated by a membrane transporter for thyroid hormone, MCT8 (SLC16A2), in the retinal pigment epithelium (RPE), which forms the outer blood-retina barrier. Mct8-deficient mice display hypothyroid-like cone gene expression and compromised electroretinogram responses. Mammalian color vision is typically facilitated by cone types that detect medium-long (M) and short (S) wavelengths of light but Mct8-deficient mice have a partial shift of M to S cone identity, resembling the phenotype of thyroid hormone receptor deficiency. RPE-specific ablation of Mct8 results in similar shifts in cone identity and hypothyroid-like gene expression whereas reexpression of MCT8 in the RPE in Mct8-deficient mice partly restores M cone identity, consistent with paracrine-like control of thyroid hormone signaling by the RPE. Our findings suggest that in addition to transport of essential solutes and homeostatic support for photoreceptors, the RPE regulates the thyroid hormone signal that promotes cone-mediated vision.

Will Japan Sink? ———The Explanation of the Seismo-Geothermics

Using the local earthquake catalog of Japan, based on the author’s original Seismo-Geothermics and it’s working methods, and from the study of the stereoscopic image of seismic cone structure, the independence of seismic cone tectonic activity and the inheritance of volcanic activity, this paper draws a conclusion that the Japanese home islands will not sink as long as earthquake still exists, volcano is still active and their lava cones are still there. In this paper, based on the independence of seismic cone tectonic activities, the general relationship between strong earthquakes, volcanoes and seismic cone tectonics in Japan and its adjacent areas is preliminarily clarified. Relying on the mature seismic data in Japan, Interested parties may be able to find out the prediction methods of intracrustal strong earthquakes and seismic cone type volcanism as soon as possible through the principle and working method of Seismo-Geothermics.

The bug-killer fly Gymnosoma rotundatum (L.) (Diptera: Tachinidae) forms the respiratory funnel independently of the host's immune response.

In internal parasitism, the respiration strategy within the host's body is as essential as evading attack from the host's immune system. Tachinid flies are parasitoids of terrestrial arthropods, mostly insects, during their larval stage. To obtain oxygen while living in the host body, they build a cylindrical structure known as the respiratory funnel at the aperture opened by the tachinid larva on the host integument or trachea. These funnels can be divided morphologically into sheath and cone types. Previous research on sheath-type funnels revealed that they are derived from the encapsulating substance produced by the host's immune system. In contrast, the cone-type funnels cover part of the body of the larval tachinid and may be constructed independently from the host immune system. To determine the mechanisms of cone-type funnel formation, histological observations were carried out on Gymnosoma rotundatum (L.) (Diptera: Tachinidae), which possesses this type of funnel. The respiratory funnel of G. rotundatum was found to be derived from the tube-shaped faeces wrapped with the peritrophic membrane and excreted by the fly larva, not from host tissue or haemocytes. Additionally, secretory glands putatively involved in the funnel formation were discovered around the larval anal plate of G. rotundatum. A comparison of funnel types within Tachinidae revealed that Phasiinae and Dexiinae have cone-type funnels, which may be created by the same mechanism as in G. rotundatum. These new findings suggest that funnel formation that does not use the host immune system is relevant to tachinid phylogeny.

Analysis of coupled system of q$$ q $$‐fractional Langevin differential equations with q$$ q $$‐fractional integral conditions

In this dissertation, we study the coupled system of ‐fractional Langevin differential equations involving ‐Caputo derivative having ‐fractional integral conditions. With the help of some adequate conditions, we investigate the uniqueness and existence of mild solution of the aforementioned system. We also analyze various kinds of Ulam's stability. Banach fixed point theorem and Leray–Schauder of cone type are used to illustrate the existence and uniqueness results. We also used non‐linear functional analysis methods to explore variety of stability types. An example is provided to clearly demonstrate our theoretical outcomes.

Ultraviolet vision in anemonefish improves colour discrimination.

In many animals, ultraviolet (UV) vision guides navigation, foraging, and communication, but few studies have addressed the contribution of UV signals to colour vision, or measured UV discrimination thresholds using behavioural experiments. Here, we tested UV colour vision in an anemonefish (Amphiprion ocellaris) using a five-channel (RGB-V-UV) LED display. We first determined that the maximal sensitivity of the A. ocellaris UV cone was ∼386 nm using microspectrophotometry. Three additional cone spectral sensitivities had maxima at ∼497, 515 and ∼535 nm. We then behaviourally measured colour discrimination thresholds by training anemonefish to distinguish a coloured target pixel from grey distractor pixels of varying intensity. Thresholds were calculated for nine sets of colours with and without UV signals. Using a tetrachromatic vision model, we found that anemonefish were better (i.e. discrimination thresholds were lower) at discriminating colours when target pixels had higher UV chromatic contrast. These colours caused a greater stimulation of the UV cone relative to other cone types. These findings imply that a UV component of colour signals and cues improves their detectability, which likely increases the prominence of anemonefish body patterns for communication and the silhouette of zooplankton prey.

Performance of tri-tubular conical energy absorber under axial compression

Quasi static axial compression loading on tri-tubular cone (TC) has been carried out using LS-DYNA finite element analysis method. Tri-tubular cones of three arrangements; the first arrangement (model TC-1) consists of cone heights of 50 mm, 75 mm and 100 mm where the inner cone is the maximum height. The second arrangement (model TC-2) consists of cone heights of 100 mm, 75 mm, and 50 mm where the outer cone is the maximum height. The third arrangement (model TC-3) consists of three cones of the same height of 100 mm. Cone semi vertex angle of 20o was maintained for all tri-tubular cones tested. Materials used for this research are glass, jute and jute-glass/epoxy. Crashworthiness analyses were performed to investigate the effect of material used, and tri-tubular cone arrangement on peak load. Crush efficiency, and absorbed energy were drawn and discussed. Failure mechanism of the fractured specimens was also discussed. Effect of number of layers and fiber stacking sequence were also investigated. Results show that the cone arrangement TC-3 gives better performance than the cone arrangement TC-2 followed by the cone arrangement TC-1. Maximum load obtained by tri-tubular cone type TC-3 was found higher 7.09% and 14.96% than TC-2 and TC-1 respectively for glass/epoxy. Material saving was achieved by using tri-tubular cones of different heights under compression. Material used has significant influence on the absorbed energy. Failure mode of tri-tubular conical energy absorber was presented and discussed.

A multi‐primary trichromator to derive individual color matching functions and cone spectral sensitivities

AbstractMeasuring color matching differences between observers is an important means of investigating individual differences in human color vision. In this article, we introduce a new LED‐based visual trichromator with which we have estimated color matching functions and cone spectral sensitivities in a group of five normal observers. The trichromator has side‐by‐side semi‐circular matching fields that are illuminated by two spectrally tunable LED light sources, each comprised of 18 LEDs with center wavelengths ranging from 400 to 700 nm. We used Maxwell's method to derive a set color match. A fixed triplet of red‐green‐blue (RGB) primaries produced the white standard field of 120 cd/m2 in one field. The other field, the mixture field, was illuminated by one of 11 different triplets of lights with various center wavelengths. Observers adjusted the intensities of the triplets in the mixture field to match the white standard field. All matches were made for field diameters of 2° and 10° of visual angle to allow comparisons with colorimetric standards and were repeated five times. Calibrations and tests showed that the trichromator and the measurements were stable and repeatable. Grassmann's laws predict that at the 11 color matches the excitations in the three cone types should be the same. Consequently, we can use those matches and a model of how cone spectral sensitivities vary between individuals to estimate the three underlying corneal cone spectral sensitivities for each observer (and thus how they vary from the standard (or mean) observer). We find good agreement with the CIE 2006 standards, but our observers show small but consistent differences.

Retinal Structure of Poecilia sphenops: Photoreceptor Mosaics, Synaptic Ribbon Patterns, and Glial Cell Expressions.

The specific arrangement and distribution of photoreceptors in the retina can vary among different fish species, with each species exhibiting adaptations related to its habitat, behavior, and visual requirements. Poecilia sphenops, a diurnal fish, was the focus of this study. The retinas of a total of eighteen Molly fish were investigated utilizing light and electron microscopy. The retina exhibited a square mosaic pattern of the inner segments of cones. This pattern comprised double cones positioned along the sides of a square, with two types of single cones situated at the center and corners of the square arrangement across the entire retina. The corner cones were slightly shorter than the central ones. Additionally, the outer plexiform layer contained both cone pedicles and rod spherules. The rod spherule consisted of a single synaptic ribbon arranged in a triad or quadrat junctional arrangement within the invaginating free ends of the horizontal and bipolar cell processes. On the other hand, cone pedicles have more than one synaptic ribbon in their junctional complex. The inner nuclear layer consisted of the amacrine, bipolar, Müller, and horizontal cell bodies. Müller cell processes, expressing GFAP, extended across all retinal layers, segmenting the deeper retina into alternating fascicles of optic axons and ganglion cells. The outer and inner plexiform layers showed many astrocyte cell processes expressing GFAP. In conclusion, the current study is the first record of the retinal structures of Molly fish. This study illustrated the mosaic arrangement of photoreceptors and GFAP expression patterns of astrocytes and Müller cells. The presence of three cone types, coupled with a sufficient number of rods, likely facilitates motion awareness for tasks like finding food and performing elaborate mating ceremonies.

On the Solvability of Iterative Systems of Fractional-Order Differential Equations with Parameterized Integral Boundary Conditions

The aim of this paper is to determine the eigenvalue intervals of $\mu_{\mathtt{k}},~1\le \mathtt{k}\le \mathtt{n}$ for which an iterative system of a class of fractional-order differential equations with parameterized integral boundary conditions (BCs) has at least one positive solution by means of standard fixed point theorem of cone type. To the best of our knowledge, this will be the first time that we attempt to reach such findings for the topic at hand in the literature. The obtained results in the paper are illustrated with an example of their feasibility.

The impact of 3-dimensional anode geometry on the electrochemical response of high temperature gas evolution reactions in molten salts

Bulk electrodes are used in molten salt electrolysis as consumable graphite anodes for existing aluminium production (producing CO2) as well as for oxygen evolution anodes in future zero emission manufacturing processes, such as direct iron electrolysis. Here, graphite electrodes with different geometry, roughness, density, and size were assessed for their kinetic behaviour and gas evolution stability in a molten alkali-metal (Li-Na-K) carbonate salt at 600 °C. It is suggested through comparative assessment of controlled electrode sizes and geometry that radial diffusion at a small (5 mm diameter disc) electrode is likely to influence performance. Roughened electrodes and electrodes of varying porosity also impacted polarisation behaviour which was ascribed to changes in electrolyte wetting observed in separate studies, conducted under similar conditions. It was also seen that 3-dimensional cone and slant type electrodes on angles of 75° increased the electrode performance. Enhanced kinetics were observed by a decreasing Tafel slope from 254 mV.decade−1 to 188 mV.decade−1 for 45° and 75° slant electrodes, respectively. The apparent improved performance for identical electrode material is discussed to involve influence from radial diffusion of reactants, modified via electrode geometry. Additional work is required to confirm this. It was concluded that to fairly compare oxidation of graphite materials in molten carbonate salts, electrodes of 10 mm diameter equivalent should have the same geometry and consistent inclination angle (of below 45°), as well as control of bulk density and resulting porosity. This observation may well also apply to other systems and should be considered in experimental design.

Cone allometry and seed protection from fire are similar in serotinous and nonserotinous conifers.

Serotiny is an adaptive trait that allows certain woody plants to persist in stand-replacing fire regimes. However, the mechanisms by which serotinous cones avoid seed necrosis and nonserotinous species persist in landscapes with short fire cycles and serotinous competitors remain poorly understood. To investigate whether ovulate cone traits that enhance seed survival differ between serotinous and nonserotinous species, we examined cone traits in 24 species within Pinaceae and Cupressaceae based on physical measurements and cone heating simulations using a computational fluid dynamics model. Fire-relevant cone traits were largely similar between cone types; those that differed (e.g. density and moisture) conferred little seed survival advantage under simulated fire. The most important traits influencing seed survival were cone size and seed depth within the cone, which was found to be an allometric function of cone mass for both cone types. Thus, nonserotinous cones should not suffer significantly greater seed necrosis than serotinous cones of equal size. Closed nonserotinous cones containing mature seeds may achieve substantial regeneration after fire if they are sufficiently large relative to fire duration and temperature. To our knowledge, this is the most comprehensive study of the effects of fire-relevant cone traits on conifer regeneration supported by physics-based fire simulation.

Effect of an Exhaust Heat Exchanger with Inserts on the Performance of Thermoelectric Generators

A thermoelectric generator is used as a waste heat recovery system for generating electric power. The thermoelectric generator system consists of an exhaust heat exchanger, a thermoelectric module, and a water heat exchanger. The aim of the current work is to explore different types of inserts used in the test section of the exhaust heat exchanger and power generation of thermoelectric generators at different operating conditions. An experimental setup has been developed for conducting experimental investigation on thermoelectric generators to find the effect of the exhaust heat exchanger (EHE) with inserts on the performance of thermoelectric generators. The cone (G-type test section) and cone-cylinder (H-type test section) type inserts were introduced to enhance the performance of the thermoelectric generator. Compared with an insert-free (empty, F-type) thermoelectric generator with cone and cone-cylinder type inserts in terms of the output power, the average heat transfer rate and convection heat transfer coefficient of F-type, G-type, and H-type test sections of the EHE are 358, 468, and 459 W and 76, 100, and 97 W/m2K, respectively. It shows that the G-type test section of EHE exchanges more heat from engine exhaust to the hot surface of the thermoelectric module through the wall of the EHE. The G-type test section created more temperature difference; obviously, it generated more power output. It was observed that the G-type and H-type test sections of exhaust heat exchangers improved average maximum output power by 29.49% and 26.11% than that by the F-type test section of heat exchanger, respectively. The F-type, G-type, and H-type test sections of exhaust heat exchangers showed a maximum average efficiency of 0.80, 0.78, and 0.70%, respectively.

Structural optimization of trays in bolt support systems

Abstract Fiber reinforced polymer (FRP) have the advantages of high strength, corrosion resistance, and low density, which are widely used to serve as tray products in bolt support systems. As a key component, the low mechanical load-bearing capacity of trays significantly limits their widespread application. Besides, there is no corresponding theoretical calculations and strength analysis methods for the structural design. The aim of this study is to optimize the tray structure and improve its load-bearing capacity. Through theoretical calculations and finite element numerical analysis, the effect of inner surface taper and stiffener height on the load-bearing capacity of the tray under the application of constant axial force is investigated. The results show that first of all, the larger the inner surface taper is, the better the load capacity of the tray. Second, the special-shaped truncated cone type displayed better load capacity than the stiffener tray. Third, the higher the design height of the stiffener is, the smaller the deformation and shear stress on the top of the inner surface of the tray, and better load capacity is achieved. We believe that this study provides theoretical guidance for the structural design of high-performance FRP trays.

Light and electron microscopic observations on retinal neurons of red-tail shark (Epalzeorhynchos bicolor H. M. Smith, 1931).

The structure of photoreceptors (PR) and the arrangement of neurons in the retina of red-tail shark were investigated using light and electron microscopy. The PR showed a mosaic arrangement and included double cones, single cones (SC), and single rods. Most cones occur as SC. The ratio between the number of cones and rods was 3:1.39 (±0.29). The rods were tall that reached the pigmented epithelium. The outer plexiform layer (OPL) showed a complex synaptic connection between the horizontal and photoreceptor terminals that were surrounded by Müller cell processes. Electron microscopy showed that the OPL possessed both cone pedicles and rod spherules. Each rod spherule consisted of a single synaptic ribbon within the invaginating terminal endings of the horizontal cell (hc) processes. In contrast, the cone pedicles possessed many synaptic ribbons within their junctional complexes. The inner nuclear layer consisted of bipolar, amacrine, Müller cells, and hc. Müller cells possessed intermediate filaments and cell processes that can reach the outer limiting membrane and form connections with each other by desmosomes. The ganglion cells were large multipolar cells with a spherical nucleus and Nissl' bodies in their cytoplasm. The presence of different types of cones arranged in a mosaic pattern in the retina of this species favors the spatial resolution of visual objects. RESEARCH HIGHLIGHTS: This is the first study demonstrating the structure and arrangement of retinal neurons of red-tail shark using light and electron microscopy. The current study showed the presence of different types of cones arranged in a mosaic pattern that may favor the spatial resolution of visual objects in this species. The bipolar, amacrine, Müller, and horizontal cells could be demonstrated.

Mapping Cones on Mars in High-Resolution Planetary Images with Deep Learning-Based Instance Segmentation

Cones are among the significant and controversial landforms on Mars. Martian cones exhibit various morphological characteristics owing to their complex origin, and their precise origin remains an active research topic. A limited number of cones have been manually mapped from high-resolution images in local areas, and existing detection methods are only applicable to a single type of cone that has a similar morphology and spatial distribution, leading to the vast majority remaining unidentified. In this paper, a novel cone identification approach is proposed that is specially designed for adequately recognizing cones from different regions in high-resolution planetary images. First, due to the lack of a publicly available cone database for reference, we annotated 3681 cones according to the literature on manual interpretation and the cone information provided by the Lunar and Planetary Laboratory (IRL) in HiRISE images. Then, the cone identification problem was converted into an instance segmentation task, i.e., a cone identification approach was designed based on deep neural networks. The Feature Pyramid Network-equipped Mask R-CNN was utilized as the detection and segmentation model. Extensive experiments were conducted for fine recognition of Martian cones with HiRISE. The results show that the proposed approach achieves high performance; it especially efficiently detects multiple types of cones while generating accurate segmentation to describe the geometry contour of cones. Finally, a Martian cone dataset with deep learning-based instance segmentation (DL-MCD) was built, containing 3861 cones for exploring geological processes on the surface of Mars.

Design and analysis of radio frequency window for the China Fusion Engineering Test Reactor ion cyclotron range of frequency heating system.

The Ion Cyclotron Range of Frequency (ICRF) heating system of the China Fusion Engineering Test Reactor (CFETR) is intended to provide plasma heating with a minimum power output of 20MW, which demands the Radio Frequency (RF) window to possess a higher performance requirement. This paper presents the design of an RF window for the CFETR ICRF heating system and focuses primarily on the design and confirmation of its electromagnetic performance. The RF window can be effectively matched in the operating frequency range and has an S11 of under -59 dB. The geometry of the cone type ceramics was optimized to reduce the surface tangential electric field distribution. An analysis of the electric field distribution of the RF window at 50kV indicates that the pressure side was below 2.3 kV/mm and the vacuum side was below 1.3 kV/mm. Furthermore, a transmission line test bench with an open-terminated setup was constructed to conduct withstand voltage tests on the mockup, and the results showed that the mockup could withstand 62kV for 2s and 47kV for 120s.