Academic literature on the topic 'Planar cluster'
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Journal articles on the topic "Planar cluster"
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Kawai, R., J. F. Tombrello, and J. H. Weare. "Li5as a pseudorotating planar cluster." Physical Review A 49, no. 5 (May 1, 1994): 4236–39. http://dx.doi.org/10.1103/physreva.49.4236.
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Wang, Meng-hui, Chen Chen, Sudip Pan, and Zhong-hua Cui. "Planar hexacoordinate gallium." Chemical Science 12, no. 45 (2021): 15067–76. http://dx.doi.org/10.1039/d1sc05089c.
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A star-like texture containing a planar hexacoordinate gallium center is reported in the lowest energy isomer of the GaBe6Au6+ cluster. High thermodynamic and kinetic stability of the title cluster makes it suitable candidate for experimental realization.
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Sucerquia, Daniel, Cristian Parra, Pilar Cossio, and Olga Lopez-Acevedo. "Ab initio metadynamics determination of temperature-dependent free-energy landscape in ultrasmall silver clusters." Journal of Chemical Physics 156, no. 15 (April 21, 2022): 154301. http://dx.doi.org/10.1063/5.0082332.
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Ab initio metadynamics enables the extraction of free-energy landscapes having the accuracy of first-principles electronic structure methods. We introduce an interface between the PLUMED code that computes free-energy landscapes and enhanced-sampling algorithms and the Atomic Simulation Environment (ASE) module, which includes several ab initio electronic structure codes. The interface is validated with a Lennard-Jones cluster free-energy landscape calculation by averaging multiple short metadynamics trajectories. We use this interface and analysis to estimate the free-energy landscape of Ag5 and Ag6 clusters at 10, 100, and 300 K with the radius of gyration and coordination number as collective variables, finding at most tens of meV in error. Relative free-energy differences between the planar and non-planar isomers of both clusters decrease with temperature in agreement with previously proposed stabilization of non-planar isomers. Interestingly, we find that Ag6 is the smallest silver cluster where entropic effects at room temperature boost the non-planar isomer probability to a competing state. The new ASE-PLUMED interface enables simulating nanosystem electronic properties under more realistic temperature-dependent conditions.
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SUBRAMANIAN, G., and DONALD L. KOCH. "Evolution of clusters of sedimenting low-Reynolds-number particles with Oseen interactions." Journal of Fluid Mechanics 603 (April 30, 2008): 63–100. http://dx.doi.org/10.1017/s0022112008000797.
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A theoretical framework is developed to describe, in the limit of small but finite Re, the evolution of dilute clusters of sedimenting particles. Here, Re =aU/ν is the particle Reynolds number, where a is the radius of the spherical particle, U its settling velocity, and ν the kinematic viscosity of the suspending fluid. The theory assumes the disturbance velocity field at sufficiently large distances from a sedimenting particle, even at small Re, to possess the familiar source--sink character; that is, the momentum defect brought in via a narrow wake behind the particle is convected radially outwards in the remaining directions. It is then argued that for spherical clusters with sufficiently many particles, specifically with N much greater than O(R0U/ν), the initial evolution is strongly influenced by wake-mediated interactions; here, N is the total number of particles, and R0 is the initial cluster radius. As a result, the cluster first evolves into a nearly planar configuration with an asymptotically small aspect ratio of O(R0U/N ν), the plane of the cluster being perpendicular to the direction of gravity; subsequent expansion occurs with an unchanged aspect ratio. For relatively sparse clusters with N smaller than O(R0U/ν), the probability of wake interactions remains negligible, and the cluster expands while retaining its spherical shape. The long-time expansion in the former case, and that for all times in the latter case, is driven by disturbance velocity fields produced by the particles outside their wakes. The resulting interactions between particles are therefore mutually repulsive with forces that obey an inverse-square law. The analysis presented describes cluster evolution in this regime. A continuum representation is adopted with the clusters being characterized by a number density field (n(r, t)), and a corresponding induced velocity field (u (r, t)) arising on account of interactions. For both planar axisymmetric clusters and spherical clusters with radial symmetry, the evolution equation admits a similarity solution; either cluster expands self-similarly for long times. The number density profiles at different times are functions of a similarity variable η = (r/t1/3), r being the radial distance away from the cluster centre, and t the time. The radius of the expanding cluster is found to be of the form Rcl (t) = A (ν a)1/3N1/3t1/3, where the constant of proportionality, A, is determined from an analytical solution of the evolution equation; one finds A = 1.743 and 1.651 for planar and spherical clusters, respectively. The number density profile in a planar axisymmetric cluster is also obtained numerically as a solution of the initial value problem for a canonical (Gaussian) initial condition. The numerical results compare well with theoretical predictions, and demonstrate the asymptotic stability of the similarity solution in two dimensions for long times, at least for axisymmetric initial conditions.
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Li, Fang, Jichun Liu, and Yichao Yang. "Non-Planar Cluster Quivers from Surface." Annals of Combinatorics 18, no. 4 (November 13, 2014): 675–707. http://dx.doi.org/10.1007/s00026-014-0247-4.
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Hakula, Harri, and Mikael Laaksonen. "Subspace Reduction for Stochastic Planar Elasticity." Applied Mechanics 3, no. 1 (December 22, 2021): 1–13. http://dx.doi.org/10.3390/applmech3010001.
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Stochastic eigenvalue problems are nonlinear and multiparametric. They require their own solution methods and remain one of the challenge problems in computational mechanics. For the simplest possible reference problems, the key is to have a cluster of at the low end of the spectrum. If the inputs, domain or material, are perturbed, the cluster breaks and tracing of the eigenpairs become difficult due to possible crossing of the modes. In this paper we have shown that the eigenvalue crossing can occur within clusters not only by perturbations of the domain, but also of material parameters. What is new is that in this setting, the crossing can be controlled; that is, the effect of the perturbations can actually be predicted. Moreover, the basis of the subspace is shown to be a well-defined concept and can be used for instance in low-rank approximation of solutions of problems with static loading. In our industrial model problem, the reduction in solution times is significant.
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Schmelzer, Jürn W. P., and Azat O. Tipeev. "Effect of Planar Interfaces on Nucleation in Melting and Crystallization." Entropy 24, no. 8 (July 26, 2022): 1029. http://dx.doi.org/10.3390/e24081029.
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The effect of planar interfaces on nucleation (namely, on the work of critical cluster formation and their shape) is studied both for crystallization and melting. Advancing an approach formulated about 150 years ago by J. W. Gibbs for liquid phase formation at planar liquid–liquid interfaces, we show that nucleation of liquids in the crystal at crystal–vapor planar interfaces proceeds as a rule with a much higher rate compared to nucleation in the bulk of the crystal. Provided the surface tensions crystal–liquid (σcl), liquid–vapor (σlv), and crystal–vapor (σcv) obey the condition σcv=σcl+σlv, the work of critical cluster formation tends to zero; in the range σcv<σcl+σlv, it is less than one half of the work of critical cluster formation for bulk nucleation. The existence of a liquid–vapor planar interface modifies the work of critical cluster formation in crystal nucleation in liquids to a much less significant degree. The work of critical crystal cluster formation is larger than one half of the bulk value of the work of critical cluster formation, reaching this limit at σcv=σcl+σlv. The shape of the critical clusters can be described in both cases by spherical caps with a radius, R, and a width parameter, h. This parameter, h, is the distance from the cutting plane (coinciding with the crystal–vapor and liquid–vapor planar interface, respectively) to the top of the spherical cap. It varies for nucleation of a liquid in a crystal in the range (h/R)≤1 and for crystal nucleation in a liquid in the range 2≥(h/R)≥1. At σcv=σcl+σlv, the ratio (h/R) of the critical cluster for nucleation in melting tends to zero ((h/R)→0). At the same condition, the critical crystallite has the shape of a sphere located tangentially to the liquid–vapor interface inside the liquid ((h/R)≅2). We present experimental data which confirm the results of the theoretical analysis, and potential further developments of the theoretical approach developed here are anticipated.
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Yildirim, E. K. "2D quasi-planar or 3D structures? A comparison between CrBn(n = 2 − 10) wheel-like clusters and their corresponding 3D pyramidal clusters, and their hydrogen storage capability." International Journal of Modern Physics B 29, no. 24 (September 30, 2015): 1550172. http://dx.doi.org/10.1142/s0217979215501726.
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In this study, we investigated stable structures for a transition metal atom–boron (CrB) wheel-like clusters and compared them with their corresponding 3D counterparts by means of density functional theory (DFT). In addition, hydrogen storage capability of the wheel-like system was investigated. All simulations were performed at the B3LYP/TZVP level of theory. We set out a complete route to the formation of CrB wheel-like clusters. Our results showed that, some of the clusters, investigated in this work (CrBn; n = 4, 6, 7, 8), either prefer to be in a 3D geometry rather than 2D quasi-planar or planar geometry. However, hydrogen doping has an interesting effect on both 2D quasi-planar and 3D geometries of this system. Simply it transforms the 3D structure, first, into a 2D quasi-planar, then a planar geometry. Furthermore, our results show that H–cluster interaction is too high for reversible hydrogen storage for these clusters.
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Yang, Yue-Ju, Shi-Xiong Li, De-Liang Chen, and Zheng-Wen Long. "Structural Evolution and Electronic Properties of Selenium-Doped Boron Clusters SeBn0/− (n = 3–16)." Molecules 28, no. 1 (January 1, 2023): 357. http://dx.doi.org/10.3390/molecules28010357.
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A theoretical research of structural evolution, electronic properties, and photoelectron spectra of selenium-doped boron clusters SeBn0/− (n = 3–16) is performed using particle swarm optimization (CALYPSO) software in combination with density functional theory calculations. The lowest energy structures of SeBn0/− (n = 3–16) clusters tend to form quasi-planar or planar structures. Some selenium-doped boron clusters keep a skeleton of the corresponding pure boron clusters; however, the addition of a Se atom modified and improved some of the pure boron cluster structures. In particular, the Se atoms of SeB7−, SeB8−, SeB10−, and SeB12− are connected to the pure quasi-planar B7−, B8−, B10−, and B12− clusters, which leads to planar SeB7−, SeB8−, SeB10−, and SeB12−, respectively. Interestingly, the lowest energy structure of SeB9− is a three-dimensional mushroom-shaped structure, and the SeB9− cluster displays the largest HOMO–LUMO gap of 5.08 eV, which shows the superior chemical stability. Adaptive natural density partitioning (AdNDP) bonding analysis reveals that SeB8 is doubly aromatic, with 6 delocalized π electrons and 6 delocalized σ electrons, whereas SeB9− is doubly antiaromatic, with 4 delocalized π electrons and 12 delocalized σ electrons. Similarly, quasi-planar SeB12 is doubly aromatic, with 6 delocalized π electrons and 14 delocalized σ electrons. The electron localization function (ELF) analysis shows that SeBn0/− (n = 3–16) clusters have different local electron delocalization and whole electron delocalization effects. The simulated photoelectron spectra of SeBn− (n = 3–16) have different characteristic bands that can identify and confirm SeBn− (n = 3–16) combined with future experimental photoelectron spectra. Our research enriches the geometrical structures of small doped boron clusters and can offer insight for boron-based nanomaterials.
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Ye, Fei, Hong Bo Xv, Jin Mei Liu, and Ke Tong. "Effects of Uniaxial Strain on the Structures of Vacancy Clusters in FCC Metals." Materials Science Forum 898 (June 2017): 1340–50. http://dx.doi.org/10.4028/www.scientific.net/msf.898.1340.
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The effects of [001] uniaxial strain on the stable structures and structural evolution of vacancy clusters in fcc metals, Cu, Ni, Al and Fe, have been studied and compared. Under uniaxial strain, the clusters in all these metals tend to align parallel or perpendicular to the strain axis under tensile or compressive strain. Moreover, both the body cluster and the {001} planar cluster become the dominant types. In addition, the stacking fault tetrahedron cluster becomes another dominant type in Al under compressive strain. The cluster structures in Fe are disordered under strain possibly because the pure fcc Fe is thermodynamically unstable under the current simulation condition.
Dissertations / Theses on the topic "Planar cluster"
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Basu, Deepan. "Generalizations and Interpretations of Incipient Infinite Cluster measure on Planar Lattices and Slabs." Doctoral thesis, Universitätsbibliothek Leipzig, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-223724.
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This thesis generalizes and interprets Kesten\'s Incipient Infinite Cluster (IIC) measure in two ways. Firstly we generalize Járai\'s result which states that for planar lattices the local configurations around a typical point taken from crossing collection is described by IIC measure. We prove in Chapter 2 that for backbone, lowest crossing and set of pivotals, the same hold true with multiple armed IIC measures. We develop certain tools, namely Russo Seymour Welsh theorem and a strong variant of quasi-multiplicativity for critical percolation on 2-dimensional slabs in Chapters 3 and 4 respectively. This enables us to first show existence of IIC in Kesten\'s sense on slabs in Chapter 4 and prove that this measure can be interpreted as the local picture around a point of crossing collection in Chapter 5.
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Basu, Deepan [Verfasser], Artem [Akademischer Betreuer] Sapozhnikov, Artem [Gutachter] Sapozhnikov, and Markus [Gutachter] Heydenreich. "Generalizations and Interpretations of Incipient Infinite Cluster measure on Planar Lattices and Slabs / Deepan Basu ; Gutachter: Artem Sapozhnikov, Markus Heydenreich ; Betreuer: Artem Sapozhnikov." Leipzig : Universitätsbibliothek Leipzig, 2017. http://d-nb.info/1240847130/34.
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Penna-Lima, M., J. G. Bartlett, E. Rozo, J. B. Melin, J. Merten, A. E. Evrard, M. Postman, and E. Rykoff. "Calibrating the Planck cluster mass scale with CLASH." EDP SCIENCES S A, 2017. http://hdl.handle.net/10150/625830.
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We determine the mass scale of Planck galaxy clusters using gravitational lensing mass measurements from the Cluster Lensing And Supernova survey with Hubble (CLASH). We have compared the lensing masses to the Planck Sunyaev-Zeldovich (SZ) mass proxy for 21 clusters in common, employing a Bayesian analysis to simultaneously fit an idealized CLASH selection function and the distribution between the measured observables and true cluster mass. We used a tiered analysis strategy to explicitly demonstrate the importance of priors on weak lensing mass accuracy. In the case of an assumed constant bias, b(SZ), between true cluster mass, M-500, and the Planck mass proxy, M-PL, our analysis constrains 1 - b(SZ) = 0.73 +/- 0.10 when moderate priors on weak lensing accuracy are used, including a zero-mean Gaussian with standard deviation of 8% to account for possible bias in lensing mass estimations. Our analysis explicitly accounts for possible selection bias effects in this calibration sourced by the CLASH selection function. Our constraint on the cluster mass scale is consistent with recent results from the Weighing the Giants program and the Canadian Cluster Comparison Project. It is also consistent, at 1.34 sigma, with the value needed to reconcile the Planck SZ cluster counts with Planck's base Lambda CDM model fit to the primary cosmic microwave background anisotropies.
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Ade, P. A. R., N. Aghanim, M. Arnaud, M. Ashdown, J. Aumont, C. Baccigalupi, A. J. Banday, et al. "Planck 2015 results." EDP SCIENCES S A, 2016. http://hdl.handle.net/10150/622773.
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We present the all-sky Planck catalogue of Sunyaev-Zeldovich (SZ) sources detected from the 29 month full-mission data. The catalogue (PSZ2) is the largest SZ-selected sample of galaxy clusters yet produced and the deepest systematic all-sky survey of galaxy clusters. It contains 1653 detections, of which 1203 are confirmed clusters with identified counterparts in external data sets, and is the first SZ-selected cluster survey containing > 10(3) confirmed clusters. We present a detailed analysis of the survey selection function in terms of its completeness and statistical reliability, placing a lower limit of 83% on the purity. Using simulations, we find that the estimates of the SZ strength parameter Y-5R500 are robust to pressure-profile variation and beam systematics, but accurate conversion to Y-500 requires the use of prior information on the cluster extent. We describe the multi-wavelength search for counterparts in ancillary data, which makes use of radio, microwave, infra-red, optical, and X-ray data sets, and which places emphasis on the robustness of the counterpart match. We discuss the physical properties of the new sample and identify a population of low-redshift X-ray under-luminous clusters revealed by SZ selection. These objects appear in optical and SZ surveys with consistent properties for their mass, but are almost absent from ROSAT X-ray selected samples.
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Tassion, Vincent. "Planarité et Localité en Percolation." Phd thesis, Ecole normale supérieure de lyon - ENS LYON, 2014. http://tel.archives-ouvertes.fr/tel-01061007.
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Cette thèse s'inscrit dans l'étude mathématique de la percolation, qui regroupe une famille de modèles présentant une transition de phase. Des avancées majeures au cours des quinze dernières années, notamment l'invention du SLE et la preuve de l'invariance conforme de la percolation de Bernoulli critique, nous permettent aujourd'hui d'avoir une image très complète de la percolation de Bernoulli sur le réseau triangulaire. Cependant, de nombreuses questions demeurent ouvertes, et ont motivé notre travail.La première d'entre elle est l'universalité de la percolation plane, qui affirme que les propriétés macroscopiques de la percolation plane critique ne devraient pas dépendre du réseau sous-jacent à sa définition. Nous montrons, dans le cadre de la percolation Divide and Color, un résultat qui va dans le sens de cette universalité et identifions, dans ce contexte, des phénomènes macroscopiques indépendants du réseau microscopique. Une version plus faible d'universalité est donnée par la théorie de Russo-Seymour-Welsh (RSW), et sa validité est connue pour la percolation de Bernoulli (sans dépendance) sur les réseaux plans suffisamment symétriques. Nous étudions de nouveaux arguments de type RSW pour des modèles de percolation avec dépendance. La deuxième question que nous avons abordée est celle de l'absence d'une composante connexe ouverte infinie au point critique, une question importante du point de vue physique, puisqu'elle traduit la continuité de la transition de phase. Dans deux travaux en collaboration avec Hugo Duminil-Copin et Vladas Sidoravicius, nous montrons que la transition de phase est continue pour la percolation de Bernoulli sur le graphe Z^2x{0,...,k}, et pour la percolation FK sur le réseau carré avec paramètre q inférieur ou égal à 4. Enfin, la dernière question qui nous a guidés est la localité du point critique : la donnée des boules de grands rayons d'un graphe suffit-elle à identifier avec une bonne précision la valeur du point critique? Dans un travail en collaboration avec Sébastien Martineau, nous répondons de manière affirmative à cette question dans le cadre des graphes de Cayley de groupes abéliens.
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Erler, Jens [Verfasser]. "Spectro-spatial observations of galaxy clusters with Planck and CCAT-prime / Jens Erler." Bonn : Universitäts- und Landesbibliothek Bonn, 2020. http://d-nb.info/1218475005/34.
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Yahiaoui, Ala-Eddine. "Selective vehicle routing problem : cluster and synchronization constraints." Thesis, Compiègne, 2018. http://www.theses.fr/2018COMP2449/document.
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Le problème de tournées de véhicules (Vehicle Routing Problem - VRP) est un problème d'optimisation combinatoire utilisé généralement pour modéliser et résoudre des différents problèmes rencontrés dans les systèmes logistiques et de transport. Dans cette thèse, nous nous sommes intéressés à l'étude et la résolution d'une classe de problèmes du VRP appelée les problèmes de courses d'orientation (Team Orienteering Problem - TOP). Dans cette catégorie de problèmes, il est a priori impossible de visiter tous les clients en raison de ressources limitées. On associe plutôt un profit à chaque client qui représente sa valeur. Ce profit est collecté lorsque le client est visité par l'un des véhicules disponibles. L'objectif est donc de sélectionner un sous ensemble de clients à servir tout en maximisant le profit total collecté. Dans un premier temps, nous avons introduit une nouvelle généralisation pour le TOP que nous avons appelé le Clustered TOP ou CluTOP. Dans cette variante, les clients sont regroupés en sous-ensembles appelés clusters auxquels nous associons des profits. Pour résoudre cette variante, nous avons proposé un schéma exact basé sur l'approche des plans sécants avec des inégalités valides supplémentaires et des pré-traitements. Nous avons également conçu une méthode heuristique basée sur l'approche order first-cluster second. Cette heuristique hybride combine une heuristique de type Adaptive Large Neighborhood Search qui explore l'espace des solutions et une procédure de découpage qui explore l'espace de recherche des tours géants. De plus, la procédure de découpage est renforcée par une recherche locale afin de mieux explorer l'espace de recherche. Le deuxième problème traité dans ce travail s'appelle le Synchronized Team Orienteering Problem with Time Windows (STOPTW). Cette variante avait été initialement proposée afin de modéliser des scénarios liés à la protection des infrastructures stratégiques menacées par l'avancée des feux de forêts. En plus des contraintes de fenêtres de temps et des visites synchronisées, cette variante considère le cas d'une flotte de véhicules hétérogène. Pour résoudre ce problème, nous avons proposé une méthode heuristique basée sur l'approche GRASP×ILS qui est parvenue à dominer la seule approche existante dans la littérature. La dernière variante du TOP abordée dans cette thèse s'appelle le Set Orienteering Problem (SOP). Les clients dans cette variante sont regroupés en sous-ensembles appelés clusters. Un profit est associé à chaque groupe qui n'est obtenu que si au moins un client est desservi par le véhicule disponible. Nous avons proposé une méthode de coupes avec deux procédures de séparation pour séparer les contraintes d'élimination des sous-tours. Nous avons également proposé un algorithme Mémétique avec une procédure de découpage optimale calculée à l'aide de la programmation dynamiqueThe Vehicle Routing Problem (VRP) is a family of Combinatorial Optimization Problems generally used to solve different issues related to transportation systems and logistics. In this thesis, we focused our attention on a variant of the VRP called the Team Orienteering Problem (TOP). In this family of problems, it is a priory impossible to visit all the customers due to travel time limitation on vehicles. Instead, a profit is associated with each customer to represent its value and it is collected once the customer is visited by one of the available vehicles. The objective function is then to maximize the total collected profit with respect to the maximum travel time. Firstly, we introduced a new generalization for the TOP that we called the Clustered TOP (CluTOP). In this variant, the customers are grouped into subsets called clusters to which we associate profits. To solve this variant, we proposed an exact scheme based on the cutting plane approach with additional valid inequalities and pre-processing techniques. We also designed a heuristic method based on the order first-cluster second approach for the CluTOP. This Hybrid Heuristic combines between an ANLS heuristic that explores the solutions space and a splitting procedure that explores the giant tours search space. In addition, the splitting procedure is enhanced by local search procedure in order to enhance its coverage of search space. The second problem treated in this work is called the Synchronized Team Orienteering Problem with Time Windows (STOPTW). This variant was initially proposed in order to model scenarios related to asset protection during escaped wildfires. It considers the case of a heterogeneous fleet of vehicles along with time windows and synchronized visits. To solve this problem, we proposed a heuristic method based on the GRASP×ILS approach that led to a very outstanding results compared to the literature. The last variant of the TOP tackled in this thesis called the Set Orienteering Problem (SOP). Customers in this variant are grouped into subsets called clusters. Each cluster is associated with a profit which is gained if at least one customer is served by the single available vehicle. We proposed a Branch-and-Cut with two separation procedures to separate subtours elimination constraints. We also proposed a Memetic Algorithm with an optimal splitting procedure based on dynamic programming
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Estay, Huidobro Rodrigo Andrés. "Seismic parameters of space - time clustered mining - induced aftershock sequences applied to seismic hazard in mining." Tesis, Universidad de Chile, 2018. http://repositorio.uchile.cl/handle/2250/168513.
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Tesis para optar al grado de Doctor en Ingeniería de MinasUna característica común en la minería que se realiza en roca competetente es la sismicidad inducida. Esta es resultado de los cambios en los esfuerzos y el fallamiento de la roca alrededor de las excavaciones mineras. Posterior a un evento sísmico, existe un aumento en los niveles de sismicidad que gradualmente decaen con el tiempo, conocido como una secuencia de réplicas. Restringir el acceso a las áreas de la mina por el tiempo suficiente que permita que ocurra este decaimiento de los eventos sísmicos es el enfoque principal de los protocolos de re entrada. Las propiedades estadísticas de las secuencias de réplicas pueden ser estudiadas mediante tres relaciones o leyes sísmicas: (1) Ley de Gutenberg Richter, (2) Ley de Omori Modificada (MOL) para el decaimiento temporal de la sismicidad, y (3) Ley de Båth para la magnitud de la réplica de mayor magnitud. Esta tesis contiene tres partes principales: estimación y correlaciones de los parámetros de las leyes sísmicas para secuencias de réplicas inducidas por la minería, desarrollo de protocolos de re entrada en el espacio tiempo magnitud y el reconocimiento y comportamiento temporal de secuencias de réplicas usando un aglomeramiento espacio tiempo. En la primera parte, se aplicaron las tres leyes sísmicas, además del modelo estocástico de Reasenberg Jones, para estudiar los parámetros de 11 secuencias sísmicas inducidas por la minería en cuatro minas en Ontario, Canadá. Para proporcionar directrices para el desarrollo del protocolo de re entrada, se estudió y aplicó la dependencia de esto parámetros con la magnitud del evento sísmico principal de la secuencia sísmica. Los resultados obtenidos son coincidentes con los que diferentes autores han estimado en sismicidad tectónica. Sin embargo, aparecen algunas "diferencias de escala", especialmente con el valor b de Gutenberg Richter y el valor p de la ley modificada de Omori, encontrando que, en promedio, hay diferencias de +0.35 y -0.2 respectivamente entre los resultados de la sismicidad inducida y tectónica. La segunda parte corresponde al desarrollo de un protocolo estocástico de re entrada en el espacio tiempo magnitud, utilizando las relaciones entre los parámetros sísmicos inducidos y la magnitud del evento principal. Se define un radio de exclusión y una relación entre el tiempo de máxima curvatura y la magnitud del evento principal. Esto permite construir curvas de decaimiento sísmico, proporcionando información sobre los patrones de decaimiento de una secuencia en curso. Finalmente, se propone un rango de probabilidad de ocurrencia de la réplica de mayor magnitud, basado en el modelo de probabilidad de Reasenberg Jones. La última parte consiste en analizar el comportamiento del agrupamiento de la sismicidad inducida por la minería a través del tiempo y el espacio. Usando el criterio estadístico de Akaike para seleccionar los parámetros del aglomeramiento espacio tiempo, fue posible identificar una secuencia de réplicas asociada a un evento principal con magnitud Mw = 0.7. Además, se encontró que la distancia espacio tiempo aparentemente disminuye su valor antes de que ocurra un evento principal, para luego retornar a su valor normal. Todos los hallazgos anteriores proporcionan una aproximación a pautas concisas y bien justificadas para el desarrollo del protocolo de re entrada.
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Verdier, Loïc. "Détection de structures par combinaison des données Planck et BOSS et détection simultanée d’amas de galaxies dans les données Planck et ROSAT." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS192/document.
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Issus de l'effondrement gravitationnel des fluctuations de matière primordiales, les amas de galaxies sont constitués d'un halo de matière noire, d'un plasma de baryon ou « gaz chaud » et de galaxies. Le comptage des amas apporte des contraintes fortes sur la cosmologie.Mon travail consiste à améliorer la détection de la composante de gaz chaud des amas, à la fois pour des structures proches et lointaines. Ce gaz chaud est détectable dans les cartes du satellite Planck par effet Sunyaev-Zel'dovich et dans les cartes du satellite ROSAT par rayonnement de freinage.La première partie de cette thèse consiste à détecter du gaz chaud dans les cartes de Planck à la position des quasars de l'expérience BOSS, donc dans des structures lointaines.Le signal est dominé par une émission de type poussière. J'ai donc élaboré un filtre capable d'extraire un signal de gaz chaud sous-dominant et de le séparer de l'émission de poussière. Le signal de gaz chaud obtenu par cette approche est significatif pour les structures à redshift z >2.5.La seconde partie de cette thèse, la détection simultanée, est dédiée à la construction d'un filtre capable d'extraire des amas (à z<1.5) individuellement dans les données ROSAT et adapté à la statistique du bruit. Ce filtre est en outre conçu dans la perspective d'être combiné avec le filtre utilisé pour détecter les amas dans les données Planck. L'objectif final étant d'obtenir plus d'amas moins massifsOriginating from the gravitational collapse of the primordial fluctuations of matter, galaxy clusters are the mixture of a dark matter halo, a baryonic plasma also called « hot gas » and several galaxies. Cluster counts provide stringent constraints on cosmology.Improving the detection of the hot gas component in nearby or distant structures is the main goal of my work. We can detect this hot gas in the Planck satellite maps thanks to the Sunyaev-Zel'dovich effect and in the ROSAT satellite maps by bremsstrahlung.The first part of my thesis is dedicated to the detection of hot gas in Planck maps at the positions of BOSS quasars, so in distant structures.Dust-like emission dominates our signal. I developped a new filter in order to separate the possible sub-dominant hot gas emision from the dust one. I get a significnt hot gas signal for structures with redshift z >2.5.In the second part of the thesis, the simultaneous detection, I build a filter suited for extracting clusters (z<1.5) individually in the ROSAT data respecting the noise statitistics. This filter is also designed to be combined with the filter used for detecting clusters in Planck maps. Increasing the number of less massive clusters will be the final goal
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Cortes, João Paulo Soares de. "Controle estrutural e classificação do canal no baixo Tapajós : contribuições para a geomorfologia da Amazônia /." Rio Claro, 2020. http://hdl.handle.net/11449/192952.
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Orientador: George Luiz LuvizottoResumo: A formação das rias fluviais na Amazônia possui uma relação bem conhecida com o processo de avanço do nível do mar durante o Holoceno. Sugestões sobre a presença de controle estrutural e tectônico na gênese destas e de outros elementos do relevo amazônico tem sido levantadas por diversos autores, porém poucos elementos conclusivos foram apresentados até o momento. Este trabalho apresenta, no primeiro momento, uma série de evidências de diferentes fontes mostrando controle estrutural ao longo do ria do Tapajós e em áreas de terra firme adjacentes. A metodologia utilizada, é inovadora por integrar dados geomorfológicos, geológicos e geofísicos (sísmica, magnetometria e gravimetria) obtidos sem custo e disponíveis para grandes áreas, o que é uma grande vantagem em uma zona de difícil acesso como a Amazônia. Trata-se ainda de uma abordagem pouco usual dentro da geomorfologia na qual encontramos resultados muito promissores. Os resultados mostram a influência de elementos estruturais na configuração do relevo amazônico na região do baixo Tapajós. É proposto um modelo de horsts e grábens limitados por lineamentos com direção ENE-WSW com expressão regional. Em seguida apresentamos uma classificação para o canal do Tapajós baseado em variáveis morfométricas extraídas de perfil transversal. A classificação apresenta três trechos distintos para o canal do Tapajós no perímetro analisado, denominados Trecho do Canal Estreito, Baixo Trecho da Ria e Alto Trecho da Ria. Estes trechos possue... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The formation of the fluvial rias in the Amazon has a well-known relationship with the process of sea level transgression during the Holocene. Suggestions about the presence of structural and tectonic control in the genesis of these and other elements of the Amazonian relief have been raised by several authors, but few conclusive elements have been presented so far. This work presents, in the first moment, a series of evidences from different sources showing structural control along the Tapajós Ria and in adjacent land areas. The methodology used is innovative because it integrates geomorphological, geological and geophysical data (seismic, magnetometry and gravimetry) obtained at no cost and available for large areas, which is a great advantage in an area of difficult access such as the Amazon. It is also an unusual approach within geomorphology in which we find very promising results. The results show the influence of structural elements in the configuration of the Amazonian relief in the region of the lower Tapajós. A model of horsts and grabens limited by lineaments with regional expression is proposed. Next, we present a classification for the Tapajós channel based on morphometric variables extracted from transversal profiles. The classification presents three distinct sections for the Tapajós channel in the analyzed perimeter, here called Narrower Channel Reach, Lower Ria Reach and Higher Ria Reach. These reaches have statistical support and agreement with most of the s... (Complete abstract click electronic access below)
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Books on the topic "Planar cluster"
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U.S. Fish and Wildlife Service. Region 1, ed. Lana'i plant cluster recovery plan. Portland, Or: U.S. Fish and Wildlife Service, 1995.
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U.S. Fish and Wildlife Service., ed. Big Island plant cluster recovery plan. Portland, Or: Published by U.S. Fish and Wildlife Service, 1996.
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Patricia, Douglas, and U.S. Fish and Wildlife Service. Region 1., eds. Big Island plant cluster recovery plan. Portland, Or: U.S. Fish and Wildlife Service, 1996.
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U.S. Fish and Wildlife Service. Region 1., ed. Lana'i plant cluster recovery plan. Portland, Or: U.S. Fish and Wildlife Service, 1995.
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U.S. Fish and Wildlife Service. Region 1, ed. Recovery plan for Koolau Mountain Plant Cluster. Portland, Or: The Service, 1996.
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U.S. Fish and Wildlife Service. Region 1. Recovery plan for the Molokai plant cluster. Portland, Or: U.S. Fish and Wildlife Service, 1996.
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Recovery plan for the Molokai plant cluster. Portland, Or: U.S. Fish and Wildlife Service, 1996.
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U.S. Fish and Wildlife Service. Region 1., ed. Recovery plan for Koolau Mountain Plant Cluster. Portland, Or: The Service, 1996.
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Sharpe, Elizabeth. Recovery plan for the Waianae plant cluster. Portland, Or: U.S. Fish and Wildlife Service, Pacific Region, 1995.
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Sharpe, Elizabeth. Recovery plan for the Waianae plant cluster. Portland, Or: U.S. Fish and Wildlife Service, Pacific Region, 1995.
Find full textBook chapters on the topic "Planar cluster"
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Berger, André, Alexander Grigoriev, and Andrej Winokurow. "A PTAS for the Cluster Editing Problem on Planar Graphs." In Approximation and Online Algorithms, 27–39. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-51741-4_3.
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Borisov, Alex B., and Charles K. Rhodes. "Stable Power Compression with Efficient Relativistic UV Channel Formation in Cluster Targets." In Planar Waveguides and other Confined Geometries, 207–25. New York, NY: Springer New York, 2014. http://dx.doi.org/10.1007/978-1-4939-1179-0_9.
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Pascoli, G. "A Simple Model for Growth of a Planar Hydrogenated Carbon Cluster under Interstellar or Circumstellar Conditions." In Planetary Nebulae, 268. Dordrecht: Springer Netherlands, 1997. http://dx.doi.org/10.1007/978-94-011-5244-0_122.
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Henckel, Dietrich, Kester von Kuczkowski, Petra Lau, Elke Pahl-Weber, and Florian Stellmacher. "CLUSTER." In Planen – Bauen –Umwelt, 94–120. Wiesbaden: VS Verlag für Sozialwissenschaften, 2010. http://dx.doi.org/10.1007/978-3-531-92288-1_3.
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Angelini, Patrizio, and Giordano Da Lozzo. "Beyond Clustered Planar Graphs." In Beyond Planar Graphs, 211–35. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-6533-5_12.
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Zhang, Xiaobo. "Cluster-Based Agricultural Development: A Comparison Between China and Africa." In Emerging-Economy State and International Policy Studies, 317–28. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-5542-6_23.
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AbstractClusters for high-value crops are ubiquitous in China and in African countries. Drawing from three case studies (potato cluster in China, medicinal and aromatic cluster in Egypt, and dates cluster in Tunisia), this chapter discusses the major challenges facing cluster development and the roles of different agents (e.g., entrepreneurs, business associations, and local governments). Cluster development involves supply-side or demand-side bottlenecks along the way, which are beyond the capacity of individual enterprises. Whether a cluster can develop to the next stage depends crucially upon whether the bottlenecks can be resolved. Because the bottlenecks are context- and temporal-specific, it would be impossible for a planner or outsider donor to prescribe a one-size-fits-all intervention to overcome all the binding constraints. Instead, local elites, such as business leaders and local officials, can play a greater role in identifying the emerging bottlenecks and figuring out indigenous solutions. In China, because local governments have an embedded interest in promoting local economic development, they are keen to provide local public goods or initiate joint actions to address the successive binding constraints and facilitate cluster development. By comparison, the role of the local government is more muted in Africa, limiting the growth potential of agricultural clusters.
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Poppa, H., C. A. Papageorgopoulos, F. Marks, and E. Bauer. "Growth and Properties of Particulate Fe Films Vapor Deposited in UHV on Planar Alumina Substrates." In Metal Clusters, 179–89. Berlin, Heidelberg: Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-71571-6_25.
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Cohn, Haldan. "Direct Fokker-Planck Calculations." In Dynamics of Star Clusters, 161–78. Dordrecht: Springer Netherlands, 1985. http://dx.doi.org/10.1007/978-94-009-5335-2_20.
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Morgan, Frank. "The Space of Planar Soap Bubble Clusters." In Imagine Math 6, 135–44. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-93949-0_12.
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Feng, Qing Wen, Robert F. Cohen, and Peter Eades. "How to draw a planar clustered graph." In Lecture Notes in Computer Science, 21–30. Berlin, Heidelberg: Springer Berlin Heidelberg, 1995. http://dx.doi.org/10.1007/bfb0030816.
Full textConference papers on the topic "Planar cluster"
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Zhai, Zongyu, Ernesto Fonseca, Ali Azad, and Barbara Cox. "A New Tool for Multi-Cluster & Multi-Well Hydraulic Fracture Modeling." In SPE Hydraulic Fracturing Technology Conference. SPE, 2015. http://dx.doi.org/10.2118/spe-173367-ms.
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Abstract Unconventional gas and tight oil reservoirs require cost-effective fracturing technologies to optimize cost versus productivity and ensure viable commercial development. Horizontal wells together with completion techniques to initiate transverse fractures have been the key to unlocking these vast resources. Variables in the completion design for fracture stimulation in a horizontal well include injection rate, fluid properties, solid loading, well spacing, cluster spacing, and the sequence and timing of pumping stages between wells in a multi-well pad. An optimized design is critical to improve hydrocarbon production and to reduce the cost. However in current practice, multi-cluster and multi-well design is primarily based on progressive experience and is typically of standardized design in a given area (e.g. the clusters and wells are evenly distributed). This is due in part by the limitations of existing hydraulic fracturing simulators, including: 1. An assumption of planar fractures; 2. Fracture interference within and among stages and adjacent wells is ignored; and 3. Numerical instability when modeling systems with large dimensionless toughness e.g. slick water injection into high-toughness rock. This paper describes an emerging non-planar 3D fracturing software package with the capability to simulate interference between hydraulic fractures propagating from multiple clusters and multiple wells. Thus, both simultaneous and sequential multiple fracture propagation can be modeled. Furthermore, numerical instability with large dimensionless toughness is solved and makes it possible to predict the fracture geometry equally well for slick water fluids. The case study in this paper shows how fracture interference and proppant distribution occurs within a stage as well as between well and stages. The simulated fracture patterns can be matched with field microseismic data and the simulated pressure trend is in agreement with field operational data. Using this approach, multi-cluster and multi-well designs can be optimized in a manner not previously possible.
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Chen, Teng-Teng, Lai-Sheng Wang, Jun Li, Xin Chen, Wan-Lu Li, Gary Lopez, and Tian Jian. "PLANAR CoB18− CLUSTER: A NEW MOTIF FOR HETERO- AND METALLO-BOROPHENES." In 71st International Symposium on Molecular Spectroscopy. Urbana, Illinois: University of Illinois at Urbana-Champaign, 2016. http://dx.doi.org/10.15278/isms.2016.wg05.
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Folluo, Carley, Caroline Chick Jarrold, Jarrett Mason, and Abbey McMahon. "PLANAR ION FUNNEL FOR IMPROVED CONTROL OF ION TRANSMISSION AND TEMPERATURE IN CLUSTER STUDIES." In 74th International Symposium on Molecular Spectroscopy. Urbana, Illinois: University of Illinois at Urbana-Champaign, 2019. http://dx.doi.org/10.15278/isms.2019.fc05.
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Mahboobi, S. H., A. Meghdari, N. Jalili, and F. Amiri. "Qualitative Study of Nanocluster Positioning Process: 2D Molecular Dynamics Simulations." In ASME 2008 International Mechanical Engineering Congress and Exposition. ASMEDC, 2008. http://dx.doi.org/10.1115/imece2008-66049.
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One of the key factors in the assembly of nanoclusters is the precise positioning of them by a manipulation system. Currently the size of clusters used as building blocks is shrinking down to a few nanometers. In such cases, the particle nature of matter plays an important role in the manipulator/cluster/substrate interactions. Having a deeper insight to the aforementioned nanoscale interactions is crucial for prediction and understanding of the behavior of nanoclusters during the positioning process. In the present research, 2D molecular dynamics simulations have been used to investigate such behaviors. Performing planar simulations can provide a fairly acceptable qualitative tool for our purpose while the computation time is greatly reduced in comparison to 3D simulations. The system consists of a tip, cluster and substrate. The focus of the present research is on ultra-fine metallic nanoclusters. To perform this research, Nose-Hoover dynamics and Sutton-Chen interatomic potential will be used to investigate the behavior of the above system which is made from different transition metals. The effects of material type, tip form and manipulation strategy on the success of the process have been investigated by planar molecular dynamics. Such qualitative simulation studies can evaluate the chance of success of a certain nanopositioning scenario regarding different working conditions before consuming large-scale computation time or high experimental expenses.
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Hossain, Md Rakib, Milon, Syed Mahedi Hasan, Md Kamal Hossain, Jahirul Islam Khandaker, Farid Ahmed, and Md Abul Hossain. "The planar B6 cluster as a motif for doping metal cation (Al3+): A DFT study." In 2017 2nd International Conference on Electrical & Electronic Engineering (ICEEE). IEEE, 2017. http://dx.doi.org/10.1109/ceee.2017.8412919.
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Tillman, S. T., K. Annamalai, and J. A. Caton. "Liftoff and Blow Off Characteristics of Laminar Non-Premixed Planar Jets." In ASME 1997 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1997. http://dx.doi.org/10.1115/imece1997-0872.
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Abstract The NOx emission from gas burners is essentially due to thermal NOx occuring at temperatures above 1500 K. Lean combustion reduces the flame temperature and hence thermal NOx production. However, operation at leaner mixtures creates problems in flame stability. It is well established that the closer the standoff distance of the flame to the burner, the more stable the flame. In the current paper, the liftoff and blow off characteristics of two dimensional planar jets (width/length ≪ 1) have been analyzed. The equations of mass, momentum, energy, and species have been transformed from compressible to incompressible form, then normalized, and converted into ordinary differential equations using an appropriate similarity variable, η. Explicit mixing solutions are obtained for a range of Schmidt numbers. The mixing solutions for single jets are used to determine flame standoff distance by matching the local axial velocity on the stoichiometric contour with the laminar burning velocity. The blow off velocity is then deduced. It has been verified, but not reported here, that the results are qualitatively similar for circular jets. It is envisioned that this model will be extrapolated to include multiple planar/cluster jets and thus allow the effect of flame interaction on liftoff height and blow off velocity to be studied.
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Holla, V. Devaraja, S. S. Krishnan, and B. Gurumoorthy. "Onvex Partitioning Approach for the Construction of Solid Model From Measured Point Data." In ASME 1998 Design Engineering Technical Conferences. American Society of Mechanical Engineers, 1998. http://dx.doi.org/10.1115/detc98/dac-5565.
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Abstract This paper describes an algorithm for the construction of solid model from measured point data using Convex Partitioning approach. Convex Partitioning approach is based on the idea that any non-convex body can be viewed as a combination of several convex pieces. The input constitutes a set or cluster of points, measured on each face of the object, which is obtained by scanning the part. Points in each cluster are used to fit a plane or a non-planar surface depending upon the type of face. Partitioning is done along the planes till one gets all the convex pieces. The individual convex pieces are then combined together to get the final model of the object. The definition of convex partition is relaxed for objects having curved faces, to be an object with all its edges convex. Apart from allowing the construction of solid model from measured point data, the output (convex pieces) obtained from this approach is useful in planning for rapid prototyping and feature suppression in finite element analysis.
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Nakamura, H. "Spontaneous phase separation to antiferromagnetic and spin-singlet states in the square-planar cluster compound V4S9Br4 observed by NMR and NQR$." In SOLID STATE PHYSICS: Proceedings of the 56th DAE Solid State Physics Symposium 2011. AIP, 2012. http://dx.doi.org/10.1063/1.4709875.
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Chelu, Cristina, Carmen Varlam, Gheorghe Titescu, and Gallia Butnaru. "Diversitatea moleculară a două ecotipuri de Datura inoxia provenite din vestul şi estul României." In International Scientific Symposium "Plant Protection – Achievements and Prospects". Institute of Genetics, Physiology and Plant Protection, Republic of Moldova, 2020. http://dx.doi.org/10.53040/9789975347204.03.
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Molecular Diversity of two Ecotypes of Datura inoxia Originating from Western and Eastern Romania. To characterize genomic variation among genotypes, we have performed RAPD analysis using ten random primers. The results yielded 88 bands out of which 39 were polymorphic. The primers US1 and US7 showed 87.71% and 72.72% polymorphism respectively. The least polymorphism was shown by primer US9 (12.50%). The primer US15 did not produce any bands suggesting the absence of matching sequences in the genomic DNA. The dendrogram classified ecotypes into two clusters (A and B); cluster B possess three sub-clusters: B1 - Socodor 2; B2 - Flamura 1 and Flamura 2, and B3 - Flamura 3. Overall, the values of genetic similarity between ecotypes were low pointing out their particular origin and “evolution”.
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Gontcharov, G., A. Mosenkov, M. Khovritchev, V. Il’in, A. Marchuk, S. Savchenko, A. Smirnov, and P. Usachev. "The properties of Galactic globular clusters from Gaia EDR3 and other data compared with theoretical isochrones." In ASTRONOMY AT THE EPOCH OF MULTIMESSENGER STUDIES. Proceedings of the VAK-2021 conference, Aug 23–28, 2021. Crossref, 2022. http://dx.doi.org/10.51194/vak2021.2022.1.1.182.
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We fit theoretical isochrones from different models of internal structure and evolution of stars to photometric data for thestars in globular clusters of our Galaxy. To select cluster members, determine cluster sizes and calculate systemic propermotions, we use parallaxes and proper motions from Gaia EDR3. To calculate the most probable distance, age, interstellarextinction in a variety of filters and differential reddening in cluster fields, we use photometry in more than 26 filters betweenthe ultraviolet and mid-infrared waverange from HST, Gaia EDR3, Pan-STARRS DR1, DES, SDSS, unWISE, SAGE andother datasets in combination with the PARSEC, MIST, DSEP, and BaSTI-IAC isochrones, as for the solar metallicityscale as for alpha- and helium-enriched scales. The metallicity and enrichment of the clusters is taken from spectroscopicobservations and tested for compliance with the photometric results. We carry out a thorough analysis of random andsystematic uncertainties of the obtained results. The derived extinctions in many filters allow us to estimate an empiricalextinction law for each cluster. A complete analysis has been performed for five clusters (NGC288, NGC362, NGC5904,NGC6205, and NGC6218), a preliminary analysis, based on the Gaia EDR3 astrometry and photometry only, has beendone for 38 more clusters. The main conclusions are as follows. First, unprecedentedly accurate astrometry of Gaia EDR3allows us to segregate the cluster members from fore- and background stars and to indicate that the size of many clustersis much larger than previously thought. Second, the distances, derived by us from the photometry-to-isochrone fitting, arestill more precise than distances from the Gaia EDR3 parallaxes. Third, contrary to the popular 2D reddening maps ofSchlegel-1998 and Planck, we found no clusters at high Galactic latitudes with an extinction A V < 0.1. Fourth, for thehorizontal branch second parameter quartet NGC 288–NGC 362–NGC 5904–NGC 6218, the age is undoubtedly the secondparameter.
Reports on the topic "Planar cluster"
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Iyer, Ananth V., Konstantina Gkritza, Steven R. Dunlop, Dutt J. Thakkar, Raul Candanedo, Srinath Jayan, Pooja Gupta, et al. Last Mile Delivery and Route Planning for Freight. Purdue University, 2021. http://dx.doi.org/10.5703/1288284317315.
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This report analyzes anticipated list mile challenges in Indiana by using a scenario-based approach to develop forecasts of GDP growth and thus freight growth across industry clusters in Indiana counties; potential congestion implied by this growth; and a proactive plan to add capacity to alleviate the congestion. We use a quantitative approach to aggregate ramp level flows, industry cluster locations, county layout, and economic activity to develop our recommendations. We develop forecasts through the year 2050 based on long-term planning approaches used by other states (California, Ohio, and Utah). We use data from global databases that consider different possible geo-political scenarios and regulatory choices to scale it down to county-level impact. At the same time, we track industry cluster locations within each county, ramps from interstates, and distances to travel within the counties to reach freight destinations. The result is a report that combines macro trends with micro detail to develop potential capacity bottlenecks.
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Iyer, Ananth V., Konstantina Gkritza, Steven R. Dunlop, Dutt J. Thakkar, Raul Candanedo, Srinath Jayan, Pooja Gupta, et al. Last Mile Delivery and Route Planning for Freight. Purdue University, 2021. http://dx.doi.org/10.5703/1288284317315.
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This report analyzes anticipated list mile challenges in Indiana by using a scenario-based approach to develop forecasts of GDP growth and thus freight growth across industry clusters in Indiana counties; potential congestion implied by this growth; and a proactive plan to add capacity to alleviate the congestion. We use a quantitative approach to aggregate ramp level flows, industry cluster locations, county layout, and economic activity to develop our recommendations. We develop forecasts through the year 2050 based on long-term planning approaches used by other states (California, Ohio, and Utah). We use data from global databases that consider different possible geo-political scenarios and regulatory choices to scale it down to county-level impact. At the same time, we track industry cluster locations within each county, ramps from interstates, and distances to travel within the counties to reach freight destinations. The result is a report that combines macro trends with micro detail to develop potential capacity bottlenecks.
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Michelmore, Richard, Eviatar Nevo, Abraham Korol, and Tzion Fahima. Genetic Diversity at Resistance Gene Clusters in Wild Populations of Lactuca. United States Department of Agriculture, February 2000. http://dx.doi.org/10.32747/2000.7573075.bard.
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Genetic resistance is often the least expensive, most effective, and ecologically-sound method of disease control. It is becoming apparent that plant genomes contain large numbers of disease resistance genes. However, the numbers of different resistance specificities within a genepool and the genetic mechanisms generating diversity are poorly understood. Our objectives were to characterize diversity in clusters of resistance genes in wild progenitors of cultivated lettuce in Israel and California in comparison to diversity within cultivated lettuce, and to determine the extent of gene flow, recombination, and genetic instability in generating variation within clusters of resistance genes. Genetic diversity of resistance genes was analyzed in wild and cultivated germplasm using molecular markers derived from lettuce resistance gene sequences of the NBS-LRR type that mapped to the major cluster if resistance genes in lettuce (Sicard et al. 1999). Three molecular markers, one microsatellite marker and two SCAR markers that amplified LRR- encoding regions, were developed from sequences of resistance gene homologs at the Dm3 cluster (RGC2s) in lettuce. Variation for these markers was assessed in germplasm including 74 genotypes of cultivated lettuce, L. saliva and 71 accessions of the three wild Lactuca spp., L. serriola, L. saligna and L. virosa that represent the major species in the sexually accessible genepool for lettuce. Diversity was also studied within and between natural populations of L. serriola from Israel and California. Large numbers of haplotypes were detected indicating the presence of numerous resistance genes in wild species. We documented a variety of genetic events occurring at clusters of resistance genes for the second objective (Sicard et al., 1999; Woo el al., in prep; Kuang et al., in prepb). The diversity of resistance genes in haplotypes provided evidence for gene duplication and unequal crossing over during the evolution of this cluster of resistance genes. Comparison of nine resistance genes in cv. Diana identified 22 gene conversion and five intergenic recombinations. We cloned and sequenced a 700 bp region from the middle of RGC2 genes from six genotypes, two each from L. saliva, L. serriola, and L. saligna . We have identified over 60 unique RGC2 sequences. Phylogenetic analysis surprisingly demonstrated much greater similarity between than within genotypes. This led to the realization that resistance genes are evolving much slower than had previously been assumed and to a new model as to how resistance genes are evolving (Michelmore and Meyers, 1998). The genetic structure of L. serriola was studied using 319 AFLP markers (Kuang et al., in prepa). Forty-one populations from Turkey, Armenia, Israel, and California as well as seven European countries were examined. AFLP marker data showed that the Turkish and Armenian populations were the most polymorphic populations and the European populations were the least. The Davis, CA population, a recent post-Columbian colonization, showed medium genetic diversity and was genetically close to the Turkish populations. Our results suggest that Turkey - Armenia may be the center of origin and diversity of L. serriola and may therefore have the greatest diversity of resistance genes. Our characterization of the diversity of resistance genes and the genetic mechanisms generating it will allow informed exploration, in situ and ex situ conservation, and utilization of germplasm resources for disease control. The results of this project provide the basis for our future research work, which will lead to a detailed understanding of the evolution of resistance genes in plants.
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Russo, Margherita, Fabrizio Alboni, Jorge Carreto Sanginés, Manlio De Domenico, Giuseppe Mangioni, Simone Righi, and Annamaria Simonazzi. The Changing Shape of the World Automobile Industry: A Multilayer Network Analysis of International Trade in Components and Parts. Institute for New Economic Thinking Working Paper Series, January 2022. http://dx.doi.org/10.36687/inetwp173.
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In 2018, after 25 years of the North America Trade Agreement (NAFTA), the United States requested new rules which, among other requirements, increased the regional con-tent in the production of automotive components and parts traded between the three part-ner countries, United States, Canada and Mexico. Signed by all three countries, the new trade agreement, USMCA, is to go into force in 2022. Nonetheless, after the 2020 Presi-dential election, the new treaty's future is under discussion, and its impact on the automo-tive industry is not entirely defined. Another significant shift in this industry – the acceler-ated rise of electric vehicles – also occurred in 2020: while the COVID-19 pandemic largely halted most plants in the automotive value chain all over the world, at the reopen-ing, the tide is now running against internal combustion engine vehicles, at least in the an-nouncements and in some large investments planned in Europe, Asia and the US. The definition of the pre-pandemic situation is a very helpful starting point for the analysis of the possible repercussions of the technological and geo-political transition, which has been accelerated by the epidemic, on geographical clusters and sectorial special-isations of the main regions and countries. This paper analyses the trade networks emerg-ing in the past 25 years in a new analytical framework. In the economic literature on inter-national trade, the study of the automotive global value chains has been addressed by us-ing network analysis, focusing on the centrality of geographical regions and countries while largely overlooking the contribution of countries' bilateral trading in components and parts as structuring forces of the subnetwork of countries and their specific position in the overall trade network. The paper focuses on such subnetworks as meso-level structures emerging in trade network over the last 25 years. Using the Infomap multilayer clustering algorithm, we are able to identify clusters of countries and their specific trades in the automotive internation-al trade network and to highlight the relative importance of each cluster, the interconnec-tions between them, and the contribution of countries and of components and parts in the clusters. We draw the data from the UN Comtrade database of directed export and import flows of 30 automotive components and parts among 42 countries (accounting for 98% of world trade flows of those items). The paper highlights the changes that occurred over 25 years in the geography of the trade relations, with particular with regard to denser and more hierarchical network gener-ated by Germany’s trade relations within EU countries and by the US preferential trade agreements with Canada and Mexico, and the upsurge of China. With a similar overall va-riety of traded components and parts within the main clusters (dominated respectively by Germany, US and Japan-China), the Infomap multilayer analysis singles out which com-ponents and parts determined the relative positions of countries in the various clusters and the changes over time in the relative positions of countries and their specialisations in mul-tilateral trades. Connections between clusters increase over time, while the relative im-portance of the main clusters and of some individual countries change significantly. The focus on US and Mexico and on Germany and Central Eastern European countries (Czech Republic, Hungary, Poland, Slovakia) will drive the comparative analysis.
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Alfano, James, Isaac Barash, Thomas Clemente, Paul E. Staswick, Guido Sessa, and Shulamit Manulis. Elucidating the Functions of Type III Effectors from Necrogenic and Tumorigenic Bacterial Pathogens. United States Department of Agriculture, January 2010. http://dx.doi.org/10.32747/2010.7592638.bard.
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Many phytopathogenic bacteria use a type III protein secretion system (T3SS) to inject type III effectors into plant cells. In the experiments supported by this one-year feasibility study we investigated type III effector function in plants by using two contrasting bacterial pathogens: Pseudomonas syringae pv. tomato, a necrotrophic pathogen and Pantoea agglomerans, a tumorigenic pathogen. The objectives are listed below along with our major conclusions, achievements, and implications for science and agriculture. Objective 1: Compare Pseudomonas syringae and Pantoea agglomerans type III effectors in established assays to test the extent that they can suppress innate immunity and incite tumorigenesis. We tested P. agglomerans type III effectors in several innate immunity suppression assays and in several instances these effectors were capable of suppressing plant immunity, outputs that are suppressed by P. syringae effectors. Interestingly, several P. syringae effectors were able to complement gall production to a P. agglomerans pthGmutant. These results suggest that even though the disease symptoms of these pathogens are dramatically different, their type III effectors may function similarly. Objective 2: Construct P. syringae mutants in different combinations of type III-related DNA clusters to reduce type III effector redundancy. To determine their involvement in pathogenicity we constructed mutants that lack individual and multiple type III-related DNA clusters using a Flprecombinase-mediated mutagenesis strategy. The majority of single effector mutants in DC3000 have weak pathogenicity phenotypes most likely due to functional redundancy of effectors. Supporting this idea, Poly-DNAcluster deletion mutants were more significantly reduced in their ability to cause disease. Because these mutants have less functional redundancy of type III effectors, they should help identify P. syringae and P. agglomerans effectors that contribute more significantly to virulence. Objective 3: Determine the extent that P. syringae and P. agglomerans type III effectors alter hormone levels in plants. Inhibition of auxin polar transport by 2,3,5-triiodobenzoic acid (TIBA) completely prevented gall formation by P. agglomerans pv. gypsophilae in gypsophila cuttings. This result supported the hypothesis that auxin and presumably cytokinins of plant origin, rather than the IAA and cytokinins secreted by the pathogen, are mandatory for gall formation. Transgenic tobacco with pthGshowed various phenotypic traits that suggest manipulation of auxin metabolism. Moreover, the auxin levels in pthGtransgenic tobacco lines was 2-4 times higher than the control plants. External addition of auxin or cytokinins could modify the gall size in gypsophila cuttings inoculated with pthGmutant (PagMx27), but not with other type III effectors. We are currently determining hormone levels in transgenic plants expressing different type III effectors. Objective 4: Determine whether the P. agglomerans effectors HsvG/B act as transcriptional activators in plants. The P. agglomerans type III effectors HsvG and HsvB localize to the nucleus of host and nonhost plants and act as transcription activators in yeast. Three sites of adjacent arginine and lysine in HsvG and HsvB were suspected to act as Nuclear localization signals (NLS) domains. A nuclear import assay indicated two of the three putative NLS domains were functional NLSs in yeast. These were shown to be active in plants by fusing HsvG and HsvB to YFP. localization to the nucleus was dependent on these NLS domains. These achievements indicate that our research plan is feasible and suggest that type III effectors suppress innate immunity and modulate plant hormones. This information has the potential to be exploited to improve disease resistance in agricultural crops.
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Heblich, Stephan, Marlon Seror, Hao Xu, and Yanos Zylberberg. Industrial Clusters in the Long Run: Evidence from Million-Rouble Plants in China. Cambridge, MA: National Bureau of Economic Research, December 2022. http://dx.doi.org/10.3386/w30744.
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Lindow, Steven, Yedidya Gafni, Shulamit Manulis, and Isaac Barash. Role and In situ Regulation of Growth Regulators Produced in Plant-Microbe Interactions by Erwinia herbicola. United States Department of Agriculture, August 1992. http://dx.doi.org/10.32747/1992.7561059.bard.
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The main objective of this work was to gain a better understanding of how some strains of Erwinia herbicola have evolved into serious plant pathogens while also commonly existing as epiphytes on the surface of healthy plants. The focus of our studies was to determine the nature of, and regulation, of virulence factors, including the phytohormones IAA and cytokinins, which are encoded on a large plasmid (pPATH) found in gall-forming strains of this species. In addition, the in situ regulation and contribution to epiphytic fitness of a second, chromosomal, IAA biosynthetic locus (ipdC) was determined to ascertain the relative contribution of the two redundant IAA-biosynthetic pathways to the biology of E. herbicola. Genes (pre-etz and etz) conferring production of cytokinins were clustered immediately 3' of the iaaM and iaaH genes conferring IAA boisynthesis on pPATH. A new insertion-like element, IS1327, was also found immediately 3' of etz on pPATH, suggesting that these virulence factors were all introduced onto pPATH from another pathogenic bacterium. Mutants of E. herbicola in which etz, iaaH, and iaaM, but not ipdC, were disrupted caused smaller galls to form on gypsophila plants. In contrast, ipdC but not iaaH or iaaM mutants of E. herbicola exhibited reduced ability to grow and survive on plant surfaces. Transcription of ipdC was induced when cells were on plants compared to in culture, suggesting that idpC may play a selective role in fitness on leaves.
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Handa, Avtar K., Yuval Eshdat, Avichai Perl, Bruce A. Watkins, Doron Holland, and David Levy. Enhancing Quality Attributes of Potato and Tomato by Modifying and Controlling their Oxidative Stress Outcome. United States Department of Agriculture, May 2004. http://dx.doi.org/10.32747/2004.7586532.bard.
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General The final goal and overall objective of the current research has been to modify lipid hydroperoxidation in order to create desirable phenotypes in two important crops, potato and tomato, which normally are exposed to abiotic stress associated with such oxidation. The specific original objectives were: (i) the roles of lipoxygenase (LOX) and phospholipids hydroperoxide glutathione peroxidase (PHGPx) in regulating endogenous levels of lipid peroxidation in plant tissues; (ii) the effect of modified lipid peroxidation on fruit ripening, tuber quality, crop productivity and abiotic stress tolerance; (iii) the effect of simultaneous reduction of LOX and increase of PHGPx activities on fruit ripening and tuber quality; and (iv) the role of lipid peroxidation on expression of specific genes. We proposed to accomplish the research goal by genetic engineering of the metabolic activities of LOX and PHGPx using regulatable and tissue specific promoters, and study of the relationships between these two consecutive enzymes in the metabolism and catabolism of phospholipids hydroperoxides. USA Significant progress was made in accomplishing all objectives of proposed research. Due to inability to regenerate tomato plants after transforming with 35S-PHGPx chimeric gene construct, the role of low catalase induced oxidative stress instead of PHGPx was evaluated on agronomical performance of tomato plant and fruit quality attributes. Effects of polyamine, that protects DNA from oxidative stress, were also evaluated. The transgenic plants under expressing lipoxygenase (LOX-sup) were crossed with catalase antisense (CAT-anti) plants or polyamine over producing plants (SAM-over) and the lines homozygous for the two transgenes were selected. Agronomical performance of these line showed that low catalase induced oxidative stress negatively affected growth and development of tomato plants and resulted in a massive change in fruit gene expression. These effects of low catalase activity induced oxidative stress, including the massive shift in gene expression, were greatly overcome by the low lipoxygenase activity. Collectively results show that oxidative stress plays significant role in plant growth including the fruit growth. These results also for the first time indicated that a crosstalk between oxidative stress and lipoxygenase regulated processes determine the outcome during plant growth and development. Israel Regarding PHGPx, most of the study has concentrated on the first and the last specific objectives, since it became evident that plant transformation with this gene is not obvious. Following inability to achieve efficient transformation of potato and tomato using a variety of promoters, model plant systems (tobacco and potato cell cultures, tobacco calli and plantlets, and Arabidopsis) were used to establish the factors and to study the obstacles which prohibited the regeneration of plants carrying the genetic machinery for overproduction of PHGPx. Our results clearly demonstrate that while genetic transformation and over-expression of PHGPx occurs in pre-developmental tissue stage (cell culture, calli clusters) or in completed plant (Arabidopsis), it is likely that over-expression of this enzyme before tissue differentiation is leading to a halt of the regeneration process. To support this assumption, experiments, in which genetic engineering of a point-mutated PHGPx gene enable transformation and over-expression in plants of PhSPY modified in its catalytic site and thus inactive enzymatically, were successfully carried out. These combined results strongly suggest, that if in fact, like in animals and as we established in vitro, the plant PHGPx exhibits PH peroxidase activity, these peroxides are vital for the organisms developmental process.
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Iyer, Ananth, Barry Partridge, and Mary Pilotte. Understanding the Impact of INDOT Projects on Automotive Industry Cluster Logistics Costs: A Case Study of the Honda Plant. West Lafayette, Indiana: Purdue University, 2011. http://dx.doi.org/10.5703/1288284314309.
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Abdelaziz, Fatma, Nancy Abdelghany, Mia Ellis, Amy William, and Xiaobo Zhang. Cluster-based development in Egypt: A study of external shocks to the leather and medicinal and aromatic plant sectors. Washington, DC: International Food Policy Research Institute, 2021. http://dx.doi.org/10.2499/p15738coll2.134948.
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