Journal articles: 'Cylindrical topologies'

1

Arango, Ivan, and Catherine Cifuentes. "Design to Achieve Accuracy in Ink-Jet Cylindrical Printing Machines." Machines 7, no. 1 (January 11, 2019): 6. http://dx.doi.org/10.3390/machines7010006.

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Machines for direct digital inkjet printing on cylindrical containers are a new technology out on the market. The commercialization in the industrial sector has been affected by their high precision. This led to the use of mechanisms with narrow manufacturing tolerances and to the searches for topologies that have the least accumulated error without affecting quality. Machines with topologies that work on flat substrates have printing and productivity problems working on cylindrical substrates. This research paper presents the qualitative design of direct digital inkjet printers working over cylindrical substrates comparing five mechanical topologies; three topologies with radial distribution and two topologies with parallel distribution. The aim of these topologies is to find the precision, quality and efficiency of the printer taking into account the restrictions present in its construction. Each topology has separate constitutive mechanisms, the tolerance ranges between the movements of the print head and the substrate in order to determine precision are analyzed. Out of the five topologies described and analyzed in the phase diagram in section 3, three of them meet the requirements. One of the three topologies that meet the requirements is not being developed due to current technological limitations.

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Zhenyang, Lin, and D. Michael P. Mingos. "Theoretical analysis of cluster compounds with cylindrical topologies." Journal of Organometallic Chemistry 339, no. 3 (February 1988): 367–76. http://dx.doi.org/10.1016/s0022-328x(00)99398-7.

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KRASNENKER, A. "DISCONTINUITY OF FOURIER TRANSFORMS OF POISSONIAN TYPE COUNTABLY ADDITIVE MEASURES." Infinite Dimensional Analysis, Quantum Probability and Related Topics 16, no. 01 (March 2013): 1350002. http://dx.doi.org/10.1142/s0219025713500021.

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It is proved in the paper that different natural Fourier transforms (FTs) of the measure mentioned in the title are not continuous with respect to such sufficient topologies as Sazonov and Gross–Sazonov (introduced by Smolyanov [Gross–Sazonov theorem for alternating cylindrical measures, Vestnik Moskov. Univ. (4) (1983) 4–12]) topologies. The motivation of the result is the fact that the FT of the standard Wiener measure is discontinuous in a known sufficient topologies as stated by Smolyanov and Fomin (see e.g., [Measures on Topological Linear Spaces, Uspekhi Mat. Nauk31(4) (1976) 3–56]).

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Jefferies, Brian. "Cylindrical probabilities and the differentiation of vector measures." Nagoya Mathematical Journal 112 (December 1988): 25–51. http://dx.doi.org/10.1017/s0027763000001124.

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There are many results in probability theory on vector spaces which rely implicitly on the approximation of a given cylindrical probability by cylindrical probabilities with moments; for example, this is the basic idea behind the proof of the Radon equivalence of the weak and strong topologies of a metrizable space (Schwartz [13] p. 162). The technique of approximation by cylindrical measures with moments can be systematically developed. In particular, it follows that if each member of a family of cylindrical probabilities with moments is decomposable, then the limits of these cylindrical probabilities are often regular and so they are σ-additive.

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Chen, Kun-Ting, Tim Dwyer, Benjamin Bach, and Kim Marriott. "Rotate or Wrap? Interactive Visualisations of Cyclical Data on Cylindrical or Toroidal Topologies." IEEE Transactions on Visualization and Computer Graphics 28, no. 1 (January 2022): 727–36. http://dx.doi.org/10.1109/tvcg.2021.3114693.

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DREVERMANN, H., C. GRAB, B. S. NILSSON, and R. K. VOGL. "Graphical Concepts for the Representation of Events in High Energy Physics." International Journal of Modern Physics C 02, no. 01 (March 1991): 328–30. http://dx.doi.org/10.1142/s0129183191000421.

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Different methods to graphically represent points and tracks of events, measured with the ALEPH-detector at LEP, are discussed. Special emphasis is put on projections, that are adapted to the cylindrical geometry of the detector, to the track geometry of charged particles moving in a homogeneous magnetic field and to the specific event topologies, encountered in Z0 physics. A new concept, the so-called “V-plot”, is introduced, which incorporates the full three dimensional information of spatial points in a single picture. It is ideally suited for the study of more complicated event topologies, such as e.g. decays of particles within jets, and of the correlation between information from tracking and calorimetric devices. In addition, we propose ways of combining histograms and projections in a single picture. We describe methods of employing colour schemes to facilitate recognition of correlations between hits, tracks and/or subdetectors in different representations.

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DREVERMANN, H., and C. GRAB. "GRAPHICAL CONCEPTS FOR THE REPRESENTATION OF EVENTS IN HIGH ENERGY PHYSICS." International Journal of Modern Physics C 01, no. 01 (April 1990): 147–63. http://dx.doi.org/10.1142/s0129183190000074.

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Different methods to graphically represent points and tracks of events, measured with the ALEPH-detector at LEP, are discussed. Special emphasis is put on projections, that are adapted to the cylindrical geometry of the detector, to the track geometry of charged particles moving in a homogeneous magnetic field and to the event topologies, encountered in Z0 physics. A new concept, the so-called "V-plot", is introduced, which incorporates the full three-dimensional information of spatial points in a single picture. It is ideally suited for the study of more complicated event topologies, such as e.g. decays of particles within jets, and of the correlation between tracks and calorimeter clusters. In addition, we propose ways of combining histograms and projections to incorporate the tracking and calorimetric information into a single picture. We describe methods of employing colour schemes to facilitate recognition of correlations between hits, tracks and/or subdetectors in different representations.

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Zhong, B., and N. Qin. "Non-inertial multiblock Navier-Stokes calculation for hovering rotor flowfields using relative velocity approach." Aeronautical Journal 105, no. 1049 (July 2001): 379–89. http://dx.doi.org/10.1017/s000192400001229x.

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AbstractA three dimensional Navier-Stokes solver is presented for calculating the hovering rotor flowfield using Osher's approximate Riemann solver. The Navier-Stokes equations are recast in the attached blade relative system using relative flow velocities as variables. Multiblock techniques are used to obtain a structured grid around the blade. A modified MUSCL scheme is proposed to alleviate the inaccuracy in the discretisation of the relative variable formulation. The calculations are performed for a two-bladed model rotor on C-H, O-O and C-H cylindrical grid topologies respectively. Computational solutions show reasonably good agreement with the experimental data for different lifting cases. The difficulty and suitability of different grid topologies for capturing the tip vortex is illustrated. The differences between Euler and Navier-Stokes solutions and between wake modelling and wake capturing approaches are also revealed. The results indicate that the relative velocity approach can give reasonable results for hovering rotor flowfields if due care is taken in minimising possible numerical errors.

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Qing, Xue, Tiago J. Pereira, Dieter Slos, Marjolein Couvreur, and Wim Bert. "A new species of Malenchus (Nematoda: Tylenchomorpha) with an updated phylogeny of the Tylenchidae." Nematology 20, no. 9 (2018): 815–36. http://dx.doi.org/10.1163/15685411-00003177.

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Summary The family Tylenchidae is one of most abundant and diverse nematode groups found in soil habitats. In this study, a new species named Malenchus cylindricus sp. n. is described based on light and scanning electron microscopy and molecular data. The new species is characterised by elongate-cylindrical vulva-anus body shape and a narrow annulation. We updated the phylogeny of Tylenchidae by including molecular data for the rare genera Miculenchus and Tenunemellus and by improving the morphological characterisation of the genus Lelenchus. Additionally, we compared the effect of alignment methods on the tree topologies and branch support values. The results suggest that the position of subfamily Ecphyadophorinae within Tylenchidae needs to be further revised. Phylogenies inferred from different sequence-based alignments were relatively more similar (i.e., tree topology and branch support) to one another than to secondary structure-aided methods. Finally, conflicting branch support values can be reconciled by properly selecting the alignment method.

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Wu, Chi, and Lianwei Li. "Unified description of transportation of polymer chains with different topologies through a small cylindrical pore." Polymer 54, no. 5 (February 2013): 1463–65. http://dx.doi.org/10.1016/j.polymer.2012.12.074.

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Mersini-Houghton, Laura. "Antioscillons from bubble collisions at finite temperature." International Journal of Modern Physics D 23, no. 06 (May 2014): 1450055. http://dx.doi.org/10.1142/s0218271814500552.

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We study the role of the topology of bubbles at finite temperatures plays on collisions and the existence of new field configurations. We show that in the case of false vacuum decay at finite temperature, the cylindrical symmetry of bubbles admits a new exotic field with negative energies, the antiperiodic "twisted" field. New field configurations arise generically, not only at finite temperatures but whenever a cluster of bubbles resulting from collisions form nontrivial topologies. The interaction of both configurations induces instabilites on the bubble. Collisions of bubbles occupied by the new fields can lead to the emergence of new structures, named antioscillons.

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Komarov, I. I. "DEVELOPMENT AND RESEARCH OF THE TOPOLOGY OF COOLING BAFFLES FOR BLADES OF THE AXIAL CARBON DIOXIDE TURBINES." Eurasian Physical Technical Journal 19, no. 2 (40) (June 15, 2022): 48–57. http://dx.doi.org/10.31489/2022no2/48-57.

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Currently, there is an increase in average annual temperature and climate change across the various continents. Carbon dioxide emissions from energy facilities contributed to this condition. Implementation of oxy-fuel cycles is a promising solution for reducing carbon dioxide emissions from the energy sector. To date, the most efficient oxy-fuel cycle is the Allam cycle. In this cycle supercritical carbon dioxide acts as a working fluid of the cycle, wherein СО2’s temperature upstream of the turbine is 1,150 °С and the pressure is 30 MPa. Due to the high temperature of the working fluid, it is necessary to cool first stages of the carbon dioxide turbine. The feature of considered cooling system in this turbine is that carbon dioxide being used as a refrigerant too. This paper investigated two topologies of convective cooling systems in the carbon dioxide turbine’s nozzle blade as well as considers an option for increasing the intensity of heatexchange through the use of helical ribbing in the cylindrical cooling baffle. Numerical simulation involving the ANSYS software package was performed for two topologies of the cooling baffles arrangement in the nozzle blade body: configuration 1 -with 17 baffles of 1 mm diameter, configuration 2 -with three baffles of the blade profile shape. Configuration 1 proved to be more efficient: the Nusselt number has a value of 117, and average value of the heat transfer coefficient on the refrigerant side is 6,413 W/m2∙K. The effect of using helical ribbing in the cooling cylindrical baffle of the blade under study was investigated, which enabled to reduce the metal temperature by 54 °С on average and doubled the heat transfer coefficient.

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Jeong, Sang Min, and Massimo Ruzzene. "Analysis of Vibration and Wave Propagation in Cylindrical Grid-Like Structures." Shock and Vibration 11, no. 3-4 (2004): 311–31. http://dx.doi.org/10.1155/2004/629240.

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The wave propagation in and the vibration of cylindrical grid structures are analyzed. The grids are composed of a sequence of identical elementary cells repeating along the axial and the circumferential direction to form a two-dimensional periodic structure. Two-dimensional periodic structures are characterized by wave propagation patterns that are strongly frequency dependent and highly directional. Their wave propagation characteristics are determined through the analysis of the dynamic properties of the unit cell. Each cell here is modelled as an assembly of curved beam elements, formulated according to a mixed interpolation method. The combined application of this Finite Element formulation and the theory of two-dimensional periodic structures is used to generate the phase constant surfaces, which define, for the considered cell lay-out, the directions of wave propagation at assigned frequencies. In particular, the directions and frequencies corresponding to wave attenuation are evaluated for cells of different size and geometry, in order to identify topologies with attractive wave attenuation and vibration confinement characteristics. The predictions from the analysis of the phase constant surfaces are verified by estimating the forced harmonic response of complete cylindrical grids, obtained through the assembly of the unit cells. The considered analysis provides invaluable guidelines for the investigation of the dynamic properties and for the design of grid stiffened cylindrical shells with unique vibration confinement characteristics.

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Lian-wei, Li, Jin Fan, He Wei-dong, and Wu Chi. "How Do Polymer Chains with Different Topologies Pass Through a Cylindrical Pore under an Elongational Flow Field." Acta Polymerica Sinica 014, no. 1 (April 11, 2014): 1–21. http://dx.doi.org/10.3724/sp.j.1105.2014.13390.

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Katsigiannopoulos, Dimitrios, Eftychia Grana, Konstantina Tsitoni, Ioannis Moutsios, Gkreti-Maria Manesi, Evgeniia A. Nikitina, Nikolaos Chalmpes, et al. "Structure/Properties Relationship of Anionically Synthesized Diblock Copolymers “Grafted to” Chemically Modified Graphene." Polymers 13, no. 14 (July 14, 2021): 2308. http://dx.doi.org/10.3390/polym13142308.

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A novel approach to obtaining nanocomposite materials using anionic sequential polymerization and post-synthetic esterification reactions with chemically modified graphene sheets (CMGs) is reported. The anionically synthesized diblock copolymer precursors of the PS-b-PI-OH type were grafted to the chemically modified –COOH groups of the CMGs, giving rise to the final composite materials, namely polystyrene-b-poly(isoprene)-g-CMGs, which exhibited enhanced physicochemical properties. The successful synthesis was determined through multiple molecular characterization techniques together with thermogravimetric analysis for the verification of increased thermal stability, and the structure/properties relationship was justified through transmission electron microscopy. Furthermore, the arrangement of CMGs utilizing lamellar and cylindrical morphologies was studied in order to determine the effect of the loaded CMGs in the adopted topologies.

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Slavík, Martin, Kristína Kovalčíková, Hynek Bachratý, Katarína Bachratá, and Monika Smiešková. "Processing of Cells’ Trajectories Data for Blood Flow Simulation Model*." EPJ Web of Conferences 180 (2018): 02092. http://dx.doi.org/10.1051/epjconf/201818002092.

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Simulations of the red blood cells (RBCs) flow as a movement of elastic objects in a fluid, are developed to optimize microfluidic devices used for a blood sample analysis for diagnostic purposes in the medicine. Tracking cell behaviour during simulation helps to improve the model and adjust its parameters. For the optimization of the microfluidic devices, it is also necessary to analyse cell trajectories as well as likelihood and frequency of their occurrence in a particular device area, especially in the parts, where they can affect circulating tumour cells capture. In this article, we propose and verify several ways of processing and analysing the typology and trajectory stability in simulations with single or with a large number of red blood cells (RBCs) in devices with different topologies containing cylindrical obstacles.

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BRØNS, MORTEN, LARS KØLLGAARD VOIGT, and JENS NØRKÆR SØRENSEN. "Streamline topology of steady axisymmetric vortex breakdown in a cylinder with co- and counter-rotating end-covers." Journal of Fluid Mechanics 401 (December 25, 1999): 275–92. http://dx.doi.org/10.1017/s0022112099006588.

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Using a combination of bifurcation theory for two-dimensional dynamical systems and numerical simulations, we systematically determine the possible flow topologies of the steady vortex breakdown in axisymmetric flow in a cylindrical container with rotating end-covers. For fixed values of the ratio of the angular velocities of the covers in the range from −0.02 to 0.05, bifurcations of recirculating bubbles under variation of the aspect ratio of the cylinder and the Reynolds number are found. Bifurcation curves are determined by a simple fitting procedure of the data from the simulations. For the much studied case of zero rotation ratio (one fixed cover) a complete bifurcation diagram is constructed. Very good agreement with experimental results is obtained, and hitherto unresolved details are determined in the parameter region where up to three bubbles exist. For non-zero rotation ratios the bifurcation diagrams are found to change dramatically and give rise to other types of bifurcations.

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Dietz, Daniel, and Andreas Binder. "Bearingless PM-synchronous machine with axial active magnetic bearing fed by zero-sequence current." e & i Elektrotechnik und Informationstechnik 138, no. 2 (February 25, 2021): 62–69. http://dx.doi.org/10.1007/s00502-021-00867-4.

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AbstractA novel inverter supply for bearingless PM-synchronous motors with magnetic suspension allows the reduction of the number of power electronic switches. Hence, all six motional degrees of freedom of bearingless AC machines may be controlled via 3-phase inverter topologies. In this paper, instead of a bearingless motor consisting of two half motors, one bearingless motor with an additional radial active magnetic bearing is treated. Bearingless machines with cylindrical rotors in contrast to double cone rotors generate – apart from the electromagnetic torque – only radial magnetic forces. Hence, an axial magnetic bearing is used.For this bearing, there is no need for a feeding converter bridge as the bearing coil is fed by the zero-sequence current of the feeding 3-phase inverters. The bearing coil is placed between the two star points of the motor winding. The zero-sequence current amplitude is adjusted by the 3-phase inverters via pulse width modulation. The feasibility of this kind of axial position control is proven by simulation as well as with an experiment with a 1 kW prototype motor up to 60000 min−1.

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Ling, Zheng, Xie Ronglu, Wang Yi, and Adel El-Sabbagh. "Topology Optimization of Constrained Layer Damping on Plates Using Method of Moving Asymptote (MMA) Approach." Shock and Vibration 18, no. 1-2 (2011): 221–44. http://dx.doi.org/10.1155/2011/830793.

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Damping treatments have been extensively used as a powerful means to damp out structural resonant vibrations. Usually, damping materials are fully covered on the surface of plates. The drawbacks of this conventional treatment are also obvious due to an added mass and excess material consumption. Therefore, it is not always economical and effective from an optimization design view. In this paper, a topology optimization approach is presented to maximize the modal damping ratio of the plate with constrained layer damping treatment. The governing equation of motion of the plate is derived on the basis of energy approach. A finite element model to describe dynamic performances of the plate is developed and used along with an optimization algorithm in order to determine the optimal topologies of constrained layer damping layout on the plate. The damping of visco-elastic layer is modeled by the complex modulus formula. Considering the vibration and energy dissipation mode of the plate with constrained layer damping treatment, damping material density and volume factor are considered as design variable and constraint respectively. Meantime, the modal damping ratio of the plate is assigned as the objective function in the topology optimization approach. The sensitivity of modal damping ratio to design variable is further derived and Method of Moving Asymptote (MMA) is adopted to search the optimized topologies of constrained layer damping layout on the plate. Numerical examples are used to demonstrate the effectiveness of the proposed topology optimization approach. The results show that vibration energy dissipation of the plates can be enhanced by the optimal constrained layer damping layout. This optimal technology can be further extended to vibration attenuation of sandwich cylindrical shells which constitute the major building block of many critical structures such as cabins of aircrafts, hulls of submarines and bodies of rockets and missiles as an invaluable design tool.

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Douglas, Hume B., Robin Kundrata, Adam J. Brunke, Hermes E. Escalona, Julie T. Chapados, Jackson Eyres, Robin Richter, et al. "Anchored Phylogenomics, Evolution and Systematics of Elateridae: Are All Bioluminescent Elateroidea Derived Click Beetles?" Biology 10, no. 6 (May 21, 2021): 451. http://dx.doi.org/10.3390/biology10060451.

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Click-beetles (Coleoptera: Elateridae) are an abundant, diverse, and economically important beetle family that includes bioluminescent species. To date, molecular phylogenies have sampled relatively few taxa and genes, incompletely resolving subfamily level relationships. We present a novel probe set for anchored hybrid enrichment of 2260 single-copy orthologous genes in Elateroidea. Using these probes, we undertook the largest phylogenomic study of Elateroidea to date (99 Elateroidea, including 86 Elateridae, plus 5 non-elateroid outgroups). We sequenced specimens from 88 taxa to test the monophyly of families, subfamilies and tribes. Maximum likelihood and coalescent phylogenetic analyses produced well-resolved topologies. Notably, the included non-elaterid bioluminescent families (Lampyridae + Phengodidae + Rhagophthalmidae) form a clade within the otherwise monophyletic Elateridae, and Sinopyrophoridae may not warrant recognition as a family. All analyses recovered the elaterid subfamilies Elaterinae, Agrypninae, Cardiophorinae, Negastriinae, Pityobiinae, and Tetralobinae as monophyletic. Our results were conflicting on whether the hypnoidines are sister to Dendrometrinae or Cardiophorinae + Negastriinae. Moreover, we show that fossils with the eucnemid-type frons and elongate cylindrical shape may belong to Eucnemidae, Elateridae: Thylacosterninae, ancestral hard-bodied cantharoids or related extinct groups. Proposed taxonomic changes include recognition of Plastocerini as a tribe in Dendrometrinae and Hypnoidinae stat. nov. as a subfamily within Elateridae.

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Hedayatian, Mohammad, A. R. Daneshmehr, and G. H. Liaghat. "The Efficiency of Auxetic Cores in Sandwich Beams Subjected to Low-Velocity Impact." International Journal of Applied Mechanics 12, no. 06 (July 2020): 2050061. http://dx.doi.org/10.1142/s1758825120500611.

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This paper experimentally investigates the behavior of sandwich beam with auxetic core subjected to low-velocity impact loading. Two types of sandwich beams with different topologies of auxetic cellular cores were produced. Furthermore, a test procedure involving a cylindrical impactor was developed, and a parametric study was designed and performed. The results revealed that, at the same level of impact energy, the peak load decreased by increasing the re-entrant angle would make the auxetic sample with the highest re-entrant angle an ideal candidate for protective applications. However, in other applications where the structure needs to be protected from damage at a higher level of impact energy, the auxetic sample with the lowest re-entrant angle exhibited the best performance due to the highest amount of failure energy. Finally, the results showed that once the core structure changed from the conventional to auxetic, the energy level leading to damage to the structure increased so that it was escalated by a factor of 2 in the auxetic sample compared to the conventional sample. This is due to the negative Poisson’s ratio effect of structure that makes unit cells be drawn into the projectile impact area and, in turn, the structure is strengthened.

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Kantoch, Robert, Agnieszka Wawrzak, and Artur Tyliszczak. "Numerical analysis of influence of various bluff-body shapes on diffusion flame dynamics." Journal of Physics: Conference Series 2367, no. 1 (November 1, 2022): 012016. http://dx.doi.org/10.1088/1742-6596/2367/1/012016.

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Abstract In this paper, various bluff-body shapes (cylindrical, square, star) and two different surface topologies (smooth, wavy) are applied as passive tools for controlling a non-premixed hydrogen flame in a combustion chamber. We focus on the dynamics of the flame and its time-averaged characteristics in the close vicinity of an injection system within formed recirculation zones and also in a far-field. The research is performed with the help of large-eddy simulations (LES) method using the ANSYS Fluent software and a high-order academic code SAILOR. Flame behaviour is found to be strongly dependent on the geometry of the bluff-body whereas its wall topology affects the flame characteristics only slightly. In the cases with the square and star bluff-body, small vortical structures originating at the corners deform large vortical structures created by the Kelvin-Helmholtz instability mechanism. This intensifies the mixing and combustion process and, in the configuration with the square shape bluff-body, translates to the shortening of the recirculation zone by 15% of the equivalent bluff-body diameter and the flame, which in the axis develops closer to the bluff-body. The star shape leads to the most uniform flame at the radial border or the recirculation zone.

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Xavier, P., A. Ghani, D. Mejia, M. Miguel-Brebion, M. Bauerheim, L. Selle, and T. Poinsot. "Experimental and numerical investigation of flames stabilised behind rotating cylinders: interaction of flames with a moving wall." Journal of Fluid Mechanics 813 (January 17, 2017): 127–51. http://dx.doi.org/10.1017/jfm.2016.864.

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Steady methane/air laminar premixed flames stabilised on a cylindrical bluff body subjected to a continuous rotation are analysed using joint direct numerical simulations (DNS) and experiments. DNS are carried out using a 19 species scheme for methane/air combustion and a lumped model to predict the cylinder temperature. Rotation of the cylinder induces a symmetry breaking of the flow, and leads to two distinct flame branches in the wake of the cylinder. DNS are validated against experiments in terms of flame topologies and velocity fields. DNS are then used to analyse flame structures and thermal effects. The location and structure of the two flames are differently modified by rotation and heat transfer: a superadiabatic flame branch stabilises close to the hot cylinder and burns preheated fresh gases while a subadiabatic branch is quenched over a large zone and anchors far downstream of the cylinder. Local flame structures are shown to be controlled to first order by the local enthalpy defect or excess due to heat transfer between the cylinder and the flow. An analysis of the local wall heat flux around the cylinder shows that, for low rotation speeds, the superadiabatic flame branch contributes to wall heat fluxes that considerably exceed typical values found for classical flame/wall interactions. However, for high rotation speeds, fluxes decrease because the cylinder is surrounded by a layer of burned gases that dilute incoming reactants and shield it from the flame.

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Sreenivasaprasad, S., B. M. Meehan, P. R. Mills, and A. E. Brown. "Phylogeny and systematics of 18 Colletotrichum species based on ribosomal DNA spacer sequences." Genome 39, no. 3 (June 1, 1996): 499–512. http://dx.doi.org/10.1139/g96-064.

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The potential use of the ribosomal DNA internal transcribed spacer (ITS) sequences in understanding the phylogeny and systematics of Colletotrichum species has been evaluated. Sequence data from a limited number of isolates revealed that in Colletotrichum species the ITS 1 region (50.3% variable sites) shows a greater degree of intra- and inter-specific divergence than ITS 2 (12.4% variable sites). Nucleotide sequences of the ITS 1 region from 93 isolates representing 18 Colletotrichum species were determined. Data for 71 of these isolates where molecular and morphological identities concurred were used for phylogenetic analysis. The size of the ITS 1 region varied from 159 to 185 base pairs. Maximum intraspecific divergence was recorded with C. acutatum (5.8%), and C. capsici showed the greatest level of interspecific divergence (8.9–23.3%). Parsimony and distance analyses gave similar tree topologies. The bootstrapped consensus parsimony tree divided the 18 Colletotrichum species into six phylogenetic groups, designated 1–6. These groups, however, are not congruent with species clusterings based on spore shape. For example, the straight cylindrical spored species were represented both in groups 1 and 6; group 6 also included the falcate fusiform spored species C. capsici. The molecular evidence suggests refinement of the species concepts of some of the taxa examined. In group 6, divergence between C. gloeosporioides and C. fuscum (0.6–3.0%) or C. kahawae (0.6–3.0%) or C. fragariae (0.6–4.2%) overlap the divergence (3.6%) within C. gloeosporioides. It is suggested that C. fuscum as well as C. kahawae and C. fragariae fall within the group species C. gloeosporioides. ITS 1 data enabled clear distinction (7.1%) of Colletotrichum isolates from maize and sorghum into C. graminicola and C. sublineolum, respectively (group 2). Species such as C. acutatum, C. coccodes, C. dematium, and C. trichellum can be clearly distinguished based on ITS 1 sequence divergence, but C. destructivum cannot be confidently separated (98% homology) from C. linicola. Colletotrichum dematium f. truncatum is distinct (12.9%) from C. dematium and should probably be called C. truncatum. Key words : Colletotrichum species, rDNA, ITS 1, nucleotide sequence, phylogeny, systematics.

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Wang, Qiang, Ming Hong, and Zhongqing Su. "A sparse sensor network topologized for cylindrical wave-based identification of damage in pipeline structures." Smart Materials and Structures 25, no. 7 (May 31, 2016): 075015. http://dx.doi.org/10.1088/0964-1726/25/7/075015.

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Mulligan, T., and C. T. Russell. "Multispacecraft modeling of the flux rope structure of interplanetary coronal mass ejections: Cylindrically symmetric versus nonsymmetric topologies." Journal of Geophysical Research: Space Physics 106, A6 (June 1, 2001): 10581–96. http://dx.doi.org/10.1029/2000ja900170.

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Brew, Lewis, William Obeng-Denteh, and David Delali Zigli. "Application of Homotopy to the Ageing Process of Human Body Within the Framework of Algebraic Topology." Journal of Mathematics Research 11, no. 4 (July 11, 2019): 21. http://dx.doi.org/10.5539/jmr.v11n4p21.

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This paper presents the ageing process of the human body from the homotopy concept in the algebraic topology. The compact connected human body with boundary is assumed to be topologically equivalent to a cylinder. The complex connected cylindrical shape of the body x=S^1*I, described by the functions f,h: x→x is a Cartesian product of the vertical interval I=[0,β] and a circle S^1. The initial state of the body x=S^1*I is the topological shape of the infant. The ageing process called the homotopy is the family of continuous functions f_t(x) on the interval I=[0,α] where α>β and t≥β. It is an increasing sequence of the function f_t(x) of the body x=S^1*I. The homotopy relates the topological shape of the infant to the topological shape of the adult. The homology theory assigns to the human body (x) a sequence of abelian groups H_n(x) for n=0,1,2…and to the continuous function a sequence of homomorphism. The homology group characterizes the number and continuity of the compact surface of human body. The study excludes genetic, hormonal, environmental and other factors in the ageing process and recognizes the fact that ageing continues throughout life, through childhood, and adolescence into adulthood. Topologically the infant is equal to the adult since the infant continuously grows into the adult. The study found an algebraic way of relating homotopy to the process of ageing of human body. It was also established that this could offer other topologists useful topological tips in the application of homotopy to other physical continuous processes.    

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28

Berselli, Giovanni, Giovanni Scirè Mammano, and Eugenio Dragoni. "Design of a Dielectric Elastomer Cylindrical Actuator With Quasi-Constant Available Thrust: Modeling Procedure and Experimental Validation." Journal of Mechanical Design 136, no. 12 (October 20, 2014). http://dx.doi.org/10.1115/1.4028277.

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A novel design for a dielectric elastomer (DE) actuator is presented. The actuator is obtained by coupling a cylindrical DE film with a series of slender beams axially loaded beyond their buckling limit. Similar to previous published solutions, where different actuator geometries were coupled with compliant mechanisms of various topologies, the elastic beams are designed so as to provide a suitable compensating force that allows obtaining a quasi-constant available thrust along the entire actuator stroke. Whilst the elastic beam are sized on the basis of an analytical procedure, the overall system performance is evaluated by means of multiphysics finite element (FE) analysis, accounting for the large deflection of the buckled-beam springs (BBSs) and for the DE material hyperelasticity. Numerical and experimental results are finally provided, which demonstrate the prediction capabilities of the proposed modeling method and confirm that well-behaved cylindrical actuators can be conceived and produced.

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Frank, Alexander, Johannes Sturm, Marco Steinhardt, Alexander Rheinfeld, and Andreas Jossen. "Impact of Current Collector Design and Cooling Topology on Fast Charging of Cylindrical Lithium-Ion Batteries." ECS Advances, October 6, 2022. http://dx.doi.org/10.1149/2754-2734/ac97e0.

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Abstract The 18650 and 21700 cell format are state of the art for high-energy cylindrical lithium-ion batteries, while Tesla proposed the new 4680 format with a continuous "tabless" design as the choice for electric vehicle applications. Using an experimentally validated multidimensional multiphysics model describing a high energy NMC811/Si-C cylindrical lithium-ion battery, the effects of tabless design and cooling topologies are evaluated for 18650, 21700, and 4680 cell formats under varying charging protocols. Mantle cooling is found to be the most efficient cooling topology for a segmented tab design, whereas tab cooling performs equally well for tabless cells and achieves better performance for the 4680 format. By massively reducing polarization drops (approx. 250 mV at 3C) and heat generation inside the current collectors (up to 99%), the tabless design increases cell homogeneity and enables format-independent scalability of fast-charging performance with a tab-cooling topology. In addition, the 0 to 0.8 SoC charge time can be reduced by 4 to 10 minutes compared to cells with a segmented tab design, resulting in 16.2 minutes for the 18650 and 21700, and 16.5 minutes for the larger 4680 cell format.

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30

Jung, Ki-Ho, Hyun-Chul Lee, Joseph S. Ajiboye, Seong-Hoon Kang, and Yong-Taek Im. "The Effect of Surface Conditions on Friction by Tip Test." Journal of Tribology 132, no. 1 (November 9, 2009). http://dx.doi.org/10.1115/1.4000273.

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In the present investigation, a tip test based on upsetting and backward extrusion was utilized to characterize the effect of surface roughness of the billet and forming tools, and the type of lubricants on friction. For the test, cylindrical specimens made of aluminum alloys of 6061-O and 2024-O, and single punch and two die sets with different surface topologies, were used with four lubricants such as VG32, VG100, corn oil, and grease. The load levels and tip distances were measured for both materials, and compared with each other to determine shear friction factors at the punch and counter punch interfaces separately, depending on the variation in surface topologies and lubrications using finite element simulations. As a result, a linear relationship among the dimensionless load, tip distance, and shear friction factors at the punch and counter punch interfaces was derived for the experimental conditions investigated. The slope change of this linear relationship from negative to positive clearly depends on the variation in surface conditions at the billet/punch and billet/counter punch interfaces. Also, it was demonstrated that the dimensionless tip distance for the frictionless case can be extrapolated from the experimental data. This value can be used for characterizing the relative effect on friction due to surface conditions at the punch and counter punch, and lubrication quality of the lubricant for the given processing conditions.

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Wu, Kexin. "Study on aerodynamic features of rod thrust vector control for physical applications." Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering, May 15, 2022, 095441002210953. http://dx.doi.org/10.1177/09544100221095363.

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Mechanical thrust vector control is a classical and important branch in the vectoring control field, offering an extremely reliable control effect. In this article, a simple technology using a cylindrical rod has been numerically investigated to achieve jet controls for three-dimensional conical axisymmetric nozzles. Complex flow phenomena caused by the cylindrical rod on a flat plate and in a converging–diverging nozzle are elucidated with the purpose of a profound understanding of this technique for physical applications. Published experimental data are used to validate the dependability of current CFD results. A grid sensitivity study is carried through and analyzed. The result section discusses the impacts of three factors on performance, involving the rod penetration height, rod location, and nozzle pressure ratio. Significant vectoring performance variations and flow topologies descriptions are illuminated in full detail. When the rod penetration height changes, this technique has an effective control range, namely H/Rt ≤ 0.4. In this effective control range, the vectoring angle and efficiency increase and the thrust coefficient decreases with a deeper rod insertion. As the rod location moves downstream towards the nozzle exit, the vectoring angle increases and the thrust coefficient decays. Moreover, the direction of jet deflection remarkably varies for diverse rod locations. While the nozzle pressure ratio increases, the vectoring angle initially increases to reach the maximum level and then decays slightly. Meanwhile, the thrust coefficient continuously increases.

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32

Chakraborty, Nilanjan, Raheel Rasool, Umair Ahmed, and Markus Klein. "Relations Between Statistics of Three-Dimensional Flame Curvature and its Two-Dimensional Counterpart in Turbulent Premixed Flames." Flow, Turbulence and Combustion, August 23, 2022. http://dx.doi.org/10.1007/s10494-022-00358-2.

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AbstractThe relations between the actual flame curvature probability density function (PDF) evaluated in three-dimensions and its two-dimensional counterpart based on planar measurements have been analytically derived subject to the assumptions of isotropy and statistical independence of various angles and two-dimensional curvature. These relations have been assessed based on Direct Numerical Simulation (DNS) databases of turbulent premixed (a) statistically planar and (b) statistically axisymmetric Bunsen flames. It has been found that the analytically derived relation interlinking the PDFs of actual three-dimensional curvature and its two-dimensional counterpart holds reasonably well for a range of curvatures around the mean value defined by the inverse of the thermal flame thickness for different turbulence intensities across different combustion regimes. The flame surface is shown to exhibit predominantly two-dimensional cylindrical curvature but there is a significant probability of finding saddle type flame topologies and this probability increases with increasing turbulence intensity. The presence of saddle type flame topologies affects the ratios of second and third moments of two-dimensional and three-dimensional curvatures. It has been demonstrated that the ratios of second and third moments of two-dimensional and three-dimensional curvatures cannot be accurately predicted based on two-dimensional measurements. The ratio of the third moments of two-dimensional and three-dimensional curvatures remains positive and thus the qualitative nature of curvature skewness can still be obtained based on two-dimensional curvature measurements. As the curvature skewness is often taken to be a marker of the Darrius-Landau instability, the conclusion regarding the presence of this instability can potentially be taken from the two-dimensional curvature measurements.

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Gharehdash, Saba, Bre-Anne Louise Sainsbury, Milad Barzegar, Igor B. Palymskiy, and Pavel A. Fomin. "Topology and hydraulic permeability estimation of explosively created fractures through regular cylindrical pore network models." Engineering Computations ahead-of-print, ahead-of-print (January 7, 2021). http://dx.doi.org/10.1108/ec-04-2020-0229.

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Purpose This research study aims to develop regular cylindrical pore network models (RCPNMs) to calculate topology and geometry properties of explosively created fractures along with their resulting hydraulic permeability. The focus of the investigation is to define a method that generates a valid geometric and topologic representation from a computational modelling point of view for explosion-generated fractures in rocks. In particular, extraction of geometries from experimentally validated Eulerian smoothed particle hydrodynamics (ESPH) approach, to avoid restrictions for image-based computational methods. Design/methodology/approach Three-dimensional stabilized ESPH solution is required to model explosively created fracture networks, and the accuracy of developed ESPH is qualitatively and quantitatively examined against experimental observations for both peak detonation pressures and crack density estimations. SPH simulation domain is segmented to void and solid spaces using a graphical user interface, and the void space of blasted rocks is represented by a regular lattice of spherical pores connected by cylindrical throats. Results produced by the RCPNMs are compared to three pore network extraction algorithms. Thereby, once the accuracy of RCPNMs is confirmed, the absolute permeability of fracture networks is calculated. Findings The results obtained with RCPNMs method were compared with three pore network extraction algorithms and computational fluid dynamics method, achieving a more computational efficiency regarding to CPU cost and a better geometry and topology relationship identification, in all the cases studied. Furthermore, a reliable topology data that does not have image-based pore network limitations, and the effect of topological disorder on the computed absolute permeability is minor. However, further research is necessary to improve the interpretation of real pore systems for explosively created fracture networks. Practical implications Although only laboratory cylindrical rock specimens were tested in the computational examples, the developed approaches are applicable for field scale and complex pore network grids with arbitrary shapes. Originality/value It is often desirable to develop an integrated computational method for hydraulic conductivity of explosively created fracture networks which segmentation of fracture networks is not restricted to X-ray images, particularly when topologic and geometric modellings are the crucial parts. This research study provides insight to the reliable computational methods and pore network extraction algorithm selection processes, as well as defining a practical framework for generating reliable topological and geometrical data in a Eulerian SPH setting.

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Journal articles on the topic 'Cylindrical topologies'

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