Base Of Cone Research Articles

Computer aided diagnoses for detecting the severity of Keratoconus

Abstract Problem Corneal topography instruments have limited parameter constraints for calculating precise defect ratios on the basis of the cone base area of the anterior axial curvature map for patients with Keratoconus (KC). Aim The aim of this study is to use thresholding-based segmentation and morphological techniques to calculate the pathological ratio of the keratoconic cornea through cone base area extraction for the detection of KC severity and tracking of disease development. Methods Data were collected from February 2022 to March 2023, comprising 97 cases from private clinics in southern Iraq. Disease severity was categorized into three stages, namely, mild, moderate, and severe, according to the topographic KC classification by a senior ophthalmologist. The Galilei system was used in obtaining the corneal topography images. The study proposed an image analysis method for corneal topography images using MATLAB R2020a. The method had four main steps: preprocessing, image segmentation, morphological processing, and pathological ratio calculation. Moreover, pathological ratio was compared with the KC severity through statistical analysis. A P-value less than 0.05 indicated statistically significant results. Results The majority of the cases in the mild category had a pathological ratio of ≤20%, and the moderate category had a higher prevalence ranging from 21 to 40%. The severe category had the highest distribution (<40%). A P-value of <0.001 indicated significant and clear link between KC stages and pathologic ratio. Conclusion The algorithm used for extracting the cone base area of the keratoconic cornea at different stages was validated by an ophthalmic specialist to ensure that the cone base area was appropriately extracted. The findings may help ophthalmologists to make informed decisions for patients with severe KC and assessments based on the percentage of corneal defects.

Cone array formation on Si surfaces by low-energy He plasma irradiation with magnetron sputtering pre-deposited Ta

Low-energy ion beam irradiation, combined with the introduction of impurities, presents a promising approach for nanopatterning silicon (Si) surfaces. In this research, we investigate the surface evolution of Si (100) surfaces irradiated by 75 eV helium (He) plasma, in the presence of tantalum (Ta), traditionally regarded as an impurity incapable of initiating pattern formation, as evidenced in prior studies. The Ta impurities are pre-deposited onto the Si surfaces using the magnetron sputtering method, which offers a more controlled and quantifiable approach compared with the conventional co-deposition route. After irradiation at 800 K, dense cone arrays are produced on the Si surface. The growth of the cones is explored for fluence spanning (1–10) × 1025 m−2. The cross-sectional scanning electron microscope images indicate that the cone lengths and base width are well characterized by t1/2 dependence. The kinetics of the cone growth follow Fick’s law, characterized by an effective diffusive mechanism with the coefficients of diffusion: D = 6.49 ± 0.83 × 10−16 m−2 s−1. Transmission electron microscope observations reveal that the cone has distinct inner and outer parts with different microstructures and a clear interface. The growth mechanism of these cones is elucidated as a composite process involving preferential sputtering, the destabilizing influence of He bubbles, and the migration of adatoms.

Deep L1 Stochastic Optimal Control Policies for Planetary Soft Landing

In this paper, a novel deep-learning-based solution is introduced to the Powered Descent Guidance problem, grounded in principles of nonlinear Stochastic Optimal Control (SOC) and Feynman–Kac theory. Our algorithm solves the problem by framing it as an L1-SOC problem for minimum fuel consumption. Additionally, it can handle practically useful control constraints and nonlinear dynamics and enforces state constraints as soft constraints. This is achieved by building off of recent work on deep forward-backward stochastic differential equations and differentiable neural-network layers for nonconvex optimization based on stochastic search. In contrast to previous approaches, our algorithm does not require convexification of the constraints or linearization of the dynamics and is empirically shown to be robust to stochastic disturbances and the initial conditions of the spacecraft. After training offline, our control policy can be activated once the spacecraft is within a prespecified radius of the landing zone and at a prespecified altitude, in other words, the base of an inverted cone with the tip at the landing zone. We demonstrate empirically that our controller can successfully and safely land all trajectories initialized in the vicinity of the base of this cone as well as with randomization in the starting velocities and spacecraft mass while minimizing fuel consumption.

Loading capacity of welded hollow spherical joints strengthened by cone member

The Welded Hollow Sphere Joint (WHSJ) is frequently employed as a connection form in spatial grid structures. Structures don't retire immediately upon damage, necessitating reinforcement. However, effective solutions for reinforcing WHSJs still have shortcomings in practical engineering applications. Given this research context, a reinforcement scheme for WHSJs is proposed. Feasibility is confirmed through numerical simulation, showing that this reinforcement method is applicable to WHSJs with initial loads, enhancing their mechanical performance without being influenced by the initial loads. The study also initially uncovers the patterns of load-bearing capacity variation with geometric dimensions. Subsequently, an Artificial Neural Network (ANN) is used to predict compressive load-bearing capacity. It utilizes input variables such as sphere diameter (Ds), steel pipe diameter (Dp), reinforcement cone base diameter (Dt), sphere thickness (Ts), steel pipe thickness (Tp), cone thickness (Tt), and cone base angle (θ), with the output being the compressive load-bearing capacity of the welded hollow sphere joint post-reinforcement. Prediction errors are confined to within 10%. Using the Garson algorithm, the sensitivity analysis reveals that steel pipe thickness (Tp) and sphere thickness (Ts) play relatively significant roles in the prediction process.

The dusty heart of Circinus

In this paper we present the first-ever L- and M-band interferometric observations of Circinus, building upon a recent N-band analysis. We used these observations to reconstruct images and fit Gaussian models to the L and M bands. Our findings reveal a thin edge-on disk whose width is marginally resolved and is the spectral continuation of the disk imaged in the N band to shorter wavelengths. Additionally, we find a point-like source in the L and M bands that, based on the LMN-band spectral energy distribution fit, corresponds to the N-band point source. We also demonstrate that there is no trace of direct sightlines to hot dust surfaces in the circumnuclear dust structure of Circinus. By assuming the dust is present, we find that obscuration of AV ≳ 250 mag is necessary to reproduce the measured fluxes. Hence, the imaged disk could play the role of the obscuring “torus” in the unified scheme of active galactic nuclei. Furthermore, we explored the parameter space of the disk + hyperbolic cone radiative transfer models and identify a simple modification at the base of the cone. Adding a cluster of clumps just above the disk and inside the base of the hyperbolic cone provides a much better match to the observed temperature distribution in the central aperture. This aligns well with the radiation-driven fountain models that have recently emerged. Only the unique combination of sensitivity and spatial resolution of the VLTI allows such models to be scrutinized and constrained in detail. We plan to test the applicability of this detailed dust structure to other MATISSE-observed active galactic nuclei in the future.

Monogenetic scoria cone and associated lava flow volume estimates and their controlling factors

Estimating eruption volumes of volcanoes is crucial for studying the development and evolution of volcanoes and assessing volcanic hazards. Volume estimates for polygenetic volcanoes are well-explored but individual monogenetic volcanoes have received less attention. This could be attributed to the lower perceived hazards resulting from their smaller size and rare eruptive occurrences within volcanic fields. However, accurately determining the volume of individual monogenetic volcanoes is significant for understanding volcanic field development and evolution. Estimates of individual monogenetic eruptions may be challenging due to overlapping lava flows from different vents within a volcanic field or underestimation resulting from the breaching of small-volume scoria cones. This study aims to evaluate the relationship between the morphometric parameters of scoria cones and the volumes of associated lava flows using the globally free Advanced Land Observing Satellite (ALOS) World 3D 30 m (AW3D30) DEM, the US National Elevation Dataset (NED) 10 m DEM, and related satellite images and terrain maps. The results show that the diameter of the scoria cone base (Wco) correlates best with the associated lava flow volume, and Wco is the parameter least affected by later onlapping lava flows. Numerous factors influence the volumes of monogenetic volcanic eruptions. The regional tectonic environment, such as tectonic setting and crust thickness, has been found to control Wco and hence the volume of monogenetic volcanoes. Subduction zones and thicker crust settings are characterized by the most voluminous monogenetic volcanoes. These environments facilitate the accumulation of magma, supporting larger volcanic eruptions. Magma density also correlates with monogenetic eruption volume. Lower density magma is more likely to erupt and form larger monogenetic volcanoes. Furthermore, pre-existing crustal weaknesses such as fault systems are the main factors affecting magma movement in monogenetic shallow plumbing systems and facilitate magma ascent to the surface. Local stresses appear to have a lesser influence on eruptive volumes. Magma source shape has minor influence on monogenetic eruption volumes. Evaluation of all these parameters will provide more robust estimates of potential eruption volumes, hence informing volcanic field hazards assessment.

NEOKILIANINA CONCAVA RAMALHO, 2015 AND NEOKILIANINA RAHONENSIS (FOURY & VINCENT, 1967): A DIMORPHIC PAIR OF UPPER JURASSIC LARGER BENTHIC FORAMINIFERA?

The species Neokilianina concava Ramalho was described from the Kimmeridgian of Portugal found in the same (isochronous) levels as Neokilianina rahonensis (Foury & Vincent). The external morphology was indicated as the only difference between the two taxa, notably a pronounced concavity in the middle part of the cone base and a wider apical angle in N. concava against N. rahonensis. These differences can reasonably be considered as intraspe-cific variations, reflecting adult test dimorphism between the megalospheric (N. rahonensis) and microspheric specimens (N. concava), also suggested by their isochronous occurrence. The morphological features that were used for species discrimination are well recorded from the two generations (A-, B-forms) of other larger benthic foraminifera including the Orbitolinidae.

Numerical Investigation of the Formation of a Failure Cone during the Pullout of an Undercutting Anchor.

Previously published articles on anchors have mainly focused on determining the pullout force of the anchor (depending on the strength parameters of the concrete), the geometric parameters of the anchor head, and the effective anchor depth. The extent (volume) of the so-called failure cone has often addressed as a secondary matter, serving only to approximate the size of the zone of potential failure of the medium in which the anchor is installed. For the authors of these presented research results, from the perspective of evaluating the proposed stripping technology, an important aspect was the determination of the extent and volume of the stripping, as well as the determination of why the defragmentation of the cone of failure favors the removal of the stripping products. Therefore, it is reasonable to conduct research on the proposed topic. Thus far, the authors have shown that the ratio of the radius of the base of the destruction cone to the anchorage depth is significantly larger than in concrete (~1.5) and ranges from 3.9-4.2. The purpose of the presented research was to determine the influence of rock strength parameters on the mechanism of failure cone formation, including, in particular, the potential for defragmentation. The analysis was conducted with the finite element method (FEM) using the ABAQUS program. The scope of the analysis included two categories of rocks, i.e., those with low compressive strength (<100 MPa) and strong rocks (>100 MPa). Due to the limitations of the proposed stripping method, the analysis was conducted for an effective anchoring depth limited to 100 mm. It was shown that for anchorage depths <100 mm, for rocks with high compressive strength (above 100 MPa), there is a tendency to spontaneously generate radial cracks, leading to the fragmentation of the failure zone. The results of the numerical analysis were verified by field tests, yielding convergent results regarding the course of the de-fragmentation mechanism. In conclusion, it was found that in the case of gray sandstones, with strengths of 50-100 MPa, the uniform type of detachment (compact cone of detachment) dominates, but with a much larger radius of the base (a greater extent of detachment on the free surface).

Numerical Study of a Variable Wall Angle Made of DC01 Steel by Incremental Forming Process

Abstract Nowadays, there is a high demand for rapid prototyping parts and for products manufactured through plastic cold deformation. Incremental forming process is one of many which presents numerous advantages for fast production of complex shape parts. The purpose of this study is to develop a numerical model through finite element analysis to simulate the incremental forming process. For this analysis a variable wall angle part (VWA) which ranges from a 45° wall angle at the higher base of frustrum cone to a 70° wall angle at the base of the shape was proposed. The numerical model showed where the maximum strains are localized, how big the forces are during the process and how much the material thinned. Although the model does not indicate a possible failure of the material, the integrity of the structural stiffness was altered due to a minimum thickness reached of just 0.26mm.

Beyond Simpson's Rule: Accounting for Orientation and Ellipticity Assumptions.

Simpson's biplane rule (SBR) is considered the gold standard method for left ventricle (LV) volume quantification from echocardiography but relies on a summation-of-disks approach that makes assumptions about LV orientation and cross-sectional shape. We aim to identify key limiting factors in SBR and to develop a new robust standard for volume quantification. Three methods for computing LV volume were studied: (i) SBR, (ii) addition of a truncated basal cone (TBC) to SBR and (iii) a novel method of basal-oriented disks (BODs). Three retrospective cohorts representative of the young, adult healthy and heart failure populations were used to study the impact of anatomical variations in volume computations. Results reveal how basal slanting can cause over- and underestimation of volume, with errors by SBR and TBC >10 mL for slanting angles >6°. Only the BOD method correctly accounted for basal slanting, reducing relative volume errors by SBR from -2.23 ± 2.21% to -0.70 ± 1.91% in the adult population and similar qualitative performance in the other two cohorts. In conclusion, the summation of basal oriented disks, a novel interpretation of SBR, is a more accurate and precise method for estimating LV volume.

Hazardous Changes in Soil CO2 Emissions at Vulcano, Italy, in 2021

AbstractThe La Fossa volcano on the Island of Vulcano, Italy, showed signs of more energetic fumarolic–solfataric activity during 2021. Several increases in volcanic gas emissions and seismicity, namely, “crisis,” punctuated the passive degassing at Vulcano that had ensued after the last 1888–1890 vulcanian eruption. Most of the gases (i.e., up to 90%) were emitted at the crater cone while the diffuse degassing of CO2 at Vulcano Porto accounted for more than 10% of the volcanic emissions. Two anomalous degassing zones at the base of the volcanic cone (i.e., Palizzi and Faraglione) showed notable changes in the gas output during the volcanic crisis. In these zones, increases of soil CO2 flux (φCO2) had several practical implications other than of volcanological interest, owing to the risk related to people's exposure to volcanic gas emissions. The results of this study reveal variations of the average φCO2 from 74 g m−2 d−1 during September 2021 to 370 g m−2 d−1 in November 2021, which were 27% and 538% higher than the statistical background since 1988 (φCO2 ≈ 58 g m−2 d−1), respectively. These observations helped in volcanic surveillance at Vulcano. The soil CO2 partitioning determined using both φCO2 and carbon isotope measurements, helped track changes in the volcanic CO2 output from 9.97 · 104 to 101.15 · 104 kg d−1. Estimates for volcanic CO2 suggest that the instability of a magmatic body caused a transition from background fumarolic–solfataric activity toward an unrest event after September 2021.

Impact of Wavy Wall Surface on Hypersonic Boundary-Layer Instability of Sharp Cone Model

A comprehensive investigation of the impact of wavy wall on hypersonic boundary layers is carried out in a Mach 6 Ludwieg tube based on a 7 deg half-angle sharp cone. Linear stability theory is applied on the cone base flow with both smooth and wavy surfaces first. The evaluation of amplification rate as well as the frequency of instability waves reveals that the second mode instability is suppressed downstream of the wavy wall region. The development of instabilities is then characterized using surface flush-mounted pressure sensors and focused laser differential interferometer (FLDI). The FLDI measurement is conducted within the wavy wall zone both at troughs and at crests. Good agreement is found between the surface pressure measurement and computation, except that instability waves are invisible shortly downstream of the wavy wall. Additionally, bispectral analysis indicates that the nonlinear interaction of instability waves downstream of the wavy wall region is suppressed. FLDI measurement along the streamwise direction shows that the second mode instability waves disappear in the wavy wall region, and the boundary-layer transition process is delayed. Spatial measurement with FLDI of boundary layer identifies various types of disturbance at the troughs and crests; moreover, the co-existence of low-frequency and high-frequency disturbances is observed off the wall surface downstream of the wavy wall.

Impact of cone base diameter on outcomes of deep anterior lamellar keratoplasty in keratoconus.

To evaluate the outcomes of deep anterior lamellar keratoplasty (DALK) in treatingkeratoconus in relation to cone base diameter (CBD). A retrospective study. Sixty-one eyes of 49 keratoconus patients who underwent DALK between 2009 and 2018 were enrolled. Preoperative and postoperative uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), spherical equivalent, and astigmatism were measured. Scheimpflug tomography (Pentacam) was used to measure the cone base area (CBA) and CBD using MATLAB software. The mean age of the patients was 20.8 ± 6.1years old, and the mean follow-up time was 27.3 ± 15.2months. Mean UCVA improved from 1.23 ± 0.48 to 0.57 ± 0.27 (LogMAR, 95% CI [0.52, 0.80]; P < 0.001), whereas mean BCVA improved from 0.98 ± 0.55 to 0.18 ± 0.13 (95% CI [0.66, 0.94]; P < 0.001). The mean spherical equivalent decreased by 4.53 ± 5.65 D (95% CI [- 6.25, - 2.82]; P < 0.001), with little change in astigmatism (95% CI [- 1.39, 0.64]; P = 0.457). The postoperative BCVA in the patients with CBD < 5.07mm and corneal curvature ≥ 55D was significantly better than those whose CBD ≥ 5.07mm (0.14 ± 0.09 vs 0.25 ± 0.15, P = 0.001). The follow-up time was negatively correlated with the BCVA (P = 0.004). In this study, outcomes of DALK in keratoconus were related to CBD and corneal curvature. Patients with large CBD (≥ 5.07mm) where the corneal curvature ≥ 55D are more likely to have poor visual outcomes after DALK.

Central vs. lateral growth and evolution of the < 100 ka Peinado composite volcano, southern Central Volcanic Zone of the Andes

Composite volcanoes often display shifts in activity between central and lateral vents that are related to the local stress field and the underlying magmatic plumbing system. The Quaternary Peinado composite volcano in the southern Central Volcanic Zone (CVZ) of the Andes exhibits a striking symmetrical configuration of lateral vents around a main central cone and vent. In this contribution, we carry out detailed mapping, morphometric analysis and unspiked K-Ar dating, together with petrographic and whole-rock major oxides, trace element and Sr-Nd-Pb isotopic analyses, to constrain the growth history of the volcano and the interplay between central and lateral activity. Ten new unspiked K-Ar ages ranging between 36.8 ± 3.8 and 72.6 ± 8.0 ka highlight that Peinado is a young potentially active volcano. A main central cone-building stage ≥70–60 ka of mostly andesitic composition formed the bulk of the edifice. During this stage, vents around the cone base erupted basaltic andesite lava flows that are among the most mafic compositions of CVZ composite volcanoes, possibly related to the location of Peinado on an alignment of mafic monogenetic centers. At ~50–40 ka, the locus of activity shifted to mid-flank vents emplaced around the central vent, with eruption of andesite > basaltic andesite lava flows of similar composition to the central cone. Minor coeval-to-younger activity from the central vent was progressively more felsic, with eruption of dacitic lavas and block and ash flows, and possibly minor fallout. The shift of the bulk of activity from the central to the lateral mid-flank vents was likely related to the effects of the edifice load and magma compositions, with more mafic and dense magmas erupting preferentially through the flank vents and more differentiated magmas from the central vent. Although activity has been dominantly mafic and effusive, an evolution towards more felsic products from the central vent suggests that future activity may be somewhat explosive. The particular configuration of the lateral vents and structures around the central cone, together with other features, point towards a possible future collapse of the edifice, either a sector collapse or a caldera collapse.

Geochronological evolution of the potentially active Iliniza Volcano (Ecuador) based on new K-Ar ages

The youngest volcanism of the Ecuadorian Volcanic Front (Western Cordillera) is mainly dominated by highly explosive events, including the growth and violent destruction of lava domes, and the formation of thick pyroclastic sequences. Deposits associated with such eruptive dynamics have been identified at Iliniza, a compound volcano located in the Western Cordillera with a poorly defined evolutionary history. We present the first K-Ar ages of Iliniza volcano combined with stratigraphic data, numerical reconstructions, and geochemical analyses, providing a new perspective on its evolution. Our results show that Iliniza volcano is much younger than previously proposed. The Iliniza twin-peaked shape is the result of the superposition of two andesitic to dacitic stratovolcanoes. (1) The North Iliniza (NI) edifice was constructed by two lava successions and an intermediate satellite vent, showing a short range of mainly effusive activity between 123 ± 6 and 116 ± 2 ka. (2) The South Iliniza (SI) edifice began its construction through the Lower SI stage when massive lavas dated at ~45 ka formed a basal cone. During the Upper SI stage, the uppermost part of this edifice was destroyed by the highly explosive Jatuncama phase (VEI 5) leaving a 30–40 m-thick ignimbrite sequence. The subsequent extrusion of several dacitic lava domes reconstructed the South Iliniza summit at around 35 ka. The Terminal SI stage corresponds to the emission of several andesitic lavas between 31 ± 4 and 25 ± 3 ka. The Iliniza eruptive activity extended into the Late Pleistocene and Holocene with the extrusion of the Tishigcuchi lava dome, and the emission of the Pongo lava flow dated at 6 ± 4 ka. Based on the proposed eruptive history, we suggest that a revised volcanic hazard assessment of the potentially active Iliniza volcano is required.

Redescription of Ransomnema bravoae Sánchez-Velázquez, 1981 (Ransomnematoidea: Ransomnematidae) from Anadenobolus putealis Loomis, 1969 (Diplopoda: Rhinocricidae) from Mexico

Summary Ransomnema bravoae from the intestine of the endemic rhinocricid, Anadenobolus putealis, from Mexico, is redescribed. This species was originally described from the spirobolid Hiltonius carpinus from Morelos State, Mexico. A redescription is presented and a neotype proposed due to the loss of the type material. Ransomnema bravoae can be distinguished from all other described species of Ransomnema by the presence of a cervical expansion extending from the base of the buccal cone to approximately the last one-third of the muscular pharynx and is offset by a slight constriction at the termination point, the presence of broad lateral alae beginning at the cervical expansion termination and terminating at the phasmids, the size and distribution of the male caudal papillae, and the size of the spicules, the right spicule being 3-4 times longer than the left. Ransomnema bravoae resembles R. alatum and R. bursatum in the presence of lateral alae but differs markedly in their distribution along the body. The right spicule is within the size range of that of R. longispiculum. Males of R. bravoae possess the usual papillal composition of the genus and are very similar to that of R. christiei in that the last pair of papillae is arranged in tandem. It is similar to species where males possess three precloacal papillae placed on lateral protuberances, showing morphological affinities to Caribbean species R. artigasi and R. habanense from Cuba.

Simulation investigation of the spontaneous motion behaviors of underwater oil droplets on a conical surface.

A conical surface can realize the spontaneous transportation of micro-sized oil droplets in an aqueous environment without energy input, exhibiting great potential for applications in microfluidics, chemical micro-reactors, water remediation, etc. However, the precise manipulation of an oil droplet on a cone is still very challenging because the dynamic behavior of a droplet on a cone is not fully understood. Herein, the dynamic behavior of oil droplets on a cone is quantitively studied via numerical simulations, and the effects of wettability, apex angle, and droplet size on the droplet's dynamic behavior are systematically analyzed. The results show that the moving velocity and transport distance of the droplet on the cone are highly related to the droplet shape on the cone. It was found that a clamshell-shaped droplet moves faster than a barrel-shaped droplet. Besides, the clamshell-shaped droplet with a larger size, on the cone with a smaller apex angle and smaller contact angle tends to obtain a faster moving speed and a longer transportation distance. The droplet shape adopted on the cone was determined by the cone wettability and the size of the droplet relative to the local curvature of the cone. It was found that the oil droplet tends to form a barrel shape on the cone with a highly oleophilic and small apex angle, and tends to form a clamshell shape on cones with a highly oleophobic and large apex angle. In addition, the droplet might transit from a barrel shape to a clamshell shape when it moves from the cone tip to the cone base, and the trigger time of the transit is negatively correlated with the contact angle and apex angle of the cone. This work provides a microscale understanding of the dynamic behavior of an underwater oil droplet on a cone, and also offers theoretical guidance for manipulating the behavior of a droplet on a cone and for the rational design of cone surfaces for spontaneous droplet transport and droplet collection.

Ultrastructure of the larval eyes of the hangingfly Terrobittacus implicatus (Mecoptera: Bittacidae)

The fine structure of the larval eyes of the hangingfly Terrobittacus implicatus (Huang & Hua) was investigated using scanning and transmission electron microscopy. The results show that the larval eyes of T. implicatus each consist of seven spaced ommatidia. Each ommatidium is composed of a corneal lens with about 45 lamellae, a tetrapartite eucone type of crystalline cone, eight retinula cells, two primary pigment cells, and an undetermined number of secondary pigment cells. The rhabdomeres of eight retinula cells effectively fuse into a centrally-fused, tiered funnel-shaped rhabdom extending from the base of the crystalline cone deeply into the ommatidium. In light of different positions in the ommatidium, the retinula cells can be divided into four distal and four proximal retinula cells. Pigment cells envelop the entire ommatidium. Electron-lucent vesicles are abundant throughout the cytoplasm of the eight retinula cells. The larval ommatidia of T. implicatus are similar to those of the Panorpidae, except for the distal retinula cells that also participate in the formation of the proximal rhabdom. In this case, the larval eyes of T. implicatus may lie in the transitional stage during the larval eye evolution of insects from ommatidia to stemmata.

Design of pulse cleaning device for single-filter cartridge dust collector by multi-factor orthogonal method based numerical simulation

To solve the problem of difficulty in dust removal from single-filter cartridge dust collector equipment in confined space, an orthogonal experimental design and numerical simulation methods were adopted to optimize the ash-cleaning device. The study found that the diameter of the cone base has a greater impact on the pulse cleaning performance of the dust collector than the angle of the cone, and the installation height L has the least impact. When the optimal parameters θ = 55°, D = 80 mm, L = 0 mm, compared with the traditional dust collector, the average dust concentration at the outlet of the equipment is reduced by 11.5%, the number of cleanings is reduced by 37.5%, and the pressure at the lower part of the filter cartridge is reduced. 34.7%, the upper part increased by about 53.9%. The problem of uneven cleaning of filter cartridges in confined spaces is solved, and equipment performance is improved.

Design and Analysis of Modified Base Frame of a Cone Crusher

Crushing is the process of reducing the size of ore into definite smaller sizes. Cone crusher is a size reduction mechanical equipment which crushes the large sized limestone and dolomite particles by squeezing it between gyrating spindles. Crusher must be mounted on a frame to be coupled with the motor drive. A base frame is designed in such a way that it acts as a platform for motor and cone crusher. As the motor and cone crusher performs its operations at higher frequencies, the base frame tends to fail because of the mechanical vibrations of system and larger torques induced in the mechanism between cone crusher and base frame. Failure of base frame is prevented by using the better I-Section beams whose strength and rigidity is high. Compensators absorbs the vibrations and helps the system to attain equilibrium. A set of compensators are placed all along the I-Section. These compensators are grounded using mechanical fasteners. In the course of this research it is observed that beam has a larger tendency of failure at certain cross sections. Stiffeners could be inserted at those locations for the better rigidity, support and strength of the entire structure. Modelling and Analysis is done individually to motor frame, crusher frame and on the entire assembly. An optimum system frequency was used, for the assembly to be at equilibrium in the dynamic conditions.