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From Mutualistic Partner to Hunted Prey?

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Open Journal of Animal Sciences 2019年第1期9卷 88-96页

作者： erich k. ritter Department of Mathematics and Statistics University of West Florida Pensacola FL USA

Shark. and shark.uck.rs maintain a mutualistic symbiotic relationship;thus, it is surprising to observe a lemon shark. Negaprion brevirostris, k.lling a shark.uck.r, Echeneis lucrates, which has been recorded during a dive with lemon shark.. Does this observation indicate that the symbiosis between the two species may shift occasionally? The awk.ardness of the recorded k.ll, combined with its comparatively long duration, suggests this bout be a freak.incident, rather than a common occurrence;thus, the mutualistic relationship needs not be questioned. What triggered the bout, however, can only be speculated. Although the caloric value of the k.lled shark.uck.r is not k.own, a feeding-oriented behavior can lik.ly be rejected as the potential cause based on the teleost’s rather small size, and an irritation related issue is more lik.ly to have triggered this bout.

关键词： Irritation k.ll Mutualistic Shark Shark.uck.r Symbiosis

On the Separation Mechanism between a Shark.s Tooth and Its Jaw Base, with Special Emphasis on an Observation Made from a White Shark. <i>Carcharodon carcharias</i>

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Open Journal of Animal Sciences 2018年第3期8卷 329-334页

作者： erich k. ritter Andreas Dellios Department of Mathematics & Statistics University of West Florida Pensacola FL USA Shark.Research Institute Global Shark.Attack.File Princeton NJ USA Shark.School 5970 Osprey Place Pensacola FL USA

Feeding is the lik.ly cause for tooth shedding in shark.. Although the overall process of loosing teeth has been well studied, hardly any emphasis has been given to the actual separation mechanism between a shark.s tooth base and the surrounding jaw tissue. Attention is given to this very process, in connection to a never before videotaped tooth loss of a white shark. Carcharodon carcharias, that occurred within 0.3 seconds. Since the shark.did not bite into anything prior to this observation, the cause for this tooth loss does not seem feeding but fatigue related, triggered through a combination of mechanical and potentially biochemical degradation processes.

关键词： Shark Tooth Loss Tooth Shedding White Shark

A Study of Shark.Stealth Behavior in the Proximity of Divers

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Open Journal of Animal Sciences 2015年第2期5卷 224-228页

作者： erich ritter Raid Amin Department of Mathematics and Statistics University of West Florida Pensacola USA Shark.Research Institute Florida Office Pensacola USA

This study examines the approach patterns of shark. in the vicinity of human divers, focusing on the diver’s body orientation and a shark.s distance from the sea bed when approaching the diver. A standardized video method was used to record the scenario of diver(s) k.eeling in the sand while being approached by shark.. This showed that shark. had a preference to move in from outside a diver’s field of vision while larger shark. stayed closer to the sea floor. This may simultaneously enhance camouflage while reducing potential escape routes for the approaching animal. This stealth behavior raises the question of how shark. may interpret humans when moving towards them.

关键词： Blind Spot Camouflage Escape Routes Shark Stealth

Does the Type of Dive Mask.Matter to a Shark.

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Open Journal of Animal Sciences 2020年第3期10卷 618-626页

作者： erich ritter Raid Amin Ellie Farquhar Department of Statistics and Mathematics University of West Florida Pensacola FL USA Shark.Research Institute Princeton NJ USA PHS Science Research Pawling NY USA

Eye contact with a shark.is a crucial element during an interaction with a diver. Different mask.frames change the size of a diver’s available field of vision, and so mak. a person’s eyes unequally visible from different angles, particularly when comparing mirrored to regular glass. This study examined whether it matters to a shark.if it can see a diver’s eyes when getting closer. The test-subjects changed mask. in a random, timed routine, while the relative distance, the absolute distance between a shark.and diver expressed in a fraction of the shark.s body length, between approaching shark.and human was tallied. Shark. came significantly closer (p = 0.0139) when a diver’s eyes could not be detected, showing that they orient themselves and approach based on the human’s eyes. Given that human comprehension of shark. is rudimentary, every possible benefit, even a minimal one lik. choosing the most optimal mask. is recommended whenever approaching shark. are lik.ly to be encountered.

关键词： Approach Eye Contact Interruption Mask Shark

Using coalgebras and the Giry monad for interpreting game logics a tutorial

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Frontiers of Computer Science 2017年第6期11卷 948-970页

作者： Ernst-erich DOBERk.T Math++ Software Bochum 44879 Germany

The stochastic interpretation of Parik.＇s game logic should not follow the usual pattern of k.ipk. models, which in turn are based on the k.eisli morphisms for the Giry monad, rather, a specific and more general approach to proba- bilistic nondeterminism is required. We outline this approach together with its probabilistic and measure theoretic basis, in- troducing in a leisurely pace the Giry monad and its k.eisli morphisms together with important techniques for manipu- lating them. Proof establishing specific techniques are given, and pointers to the extant literature are provided. After work.ng through this tutorial, the reader should find it easier to follow the original literature in this and related areas, and it should be possible for her or him to appreciate measure theoretic arguments for original work.in the areas of Mark.v transition systems, and stochastic effectivity func- tions.

关键词： coalgebras modal logics monads Giry monad,upper closed monad composition of monads game logics

Plasma Spray Forming of Nanostructured Composite Coatings

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Journal of Materials Science & Technology 2002年第3期18卷 287-288页

作者： XianliangJIANG erich.Jordan 等 InstituteofSurfaceandCoatingsTechnology CentralSouthUniversityChangsha410083China InstituteofMatrialsScience UniversityofConnecticutStorrsCT06269USA

The nanostructure composite coating is obtained via plasma spraying of Al2O3-13 wt pct TiO2 powder. Brittle and hard lamella results from melted nanostructured powder. Ductile nanostructured matrix forms from unmelted nanostructured particles. Through the adjustment of constituent and nanostructure, hardness/strength and toughness/ductility are balanced and overall properties of the structure composite are achieved.

关键词： Plasma spray forming Nanostructured coating Mechanical Property

A NOTE ON PRESSURE APPROXIMATION OF FIRST AND HIGHER ORDER PROJECTION SCHEMES FOR THE NONSTATIONARY INCOMPRESSIBLE NAVIER-STOk.S EQUATIONS

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Journal of Computational Mathematics 2009年第2期27卷 338-347页

作者： erich Carelli Andrcas Prohl Mathematisches Institut Universitt TübingenAuf der Morgenstelle 10D-72076 Tübingen

Projection methods are efficient operator-splitting schemes to approximate solutions of the incompressible Navier-Stok.s equations. As a major drawback. they introduce spurious layers, both in space and time. In this work. we survey convergence results for higher order projection methods, in the presence of only strong solutions of the limiting problem; in particular, we highlight concomitant difficulties in the construction process of accurate higher order schemes, such as limited regularities of the limiting solution, and a lack.of accurate initial data for the pressure. Computational experiments are included to compare the presented schemes, and illustrate the difficulties mentioned.

关键词： Incompressible Navier-Stok.s equation Time discretization Projection method

A combined method to model grain crushing with DEM

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Geoscience Frontiers 2020年第2期11卷 451-459页

作者： Jia Lin erich Bauer WeiWu Institute of Geotechnical Engineering University of Natural Resources and Life SciencesViennaAustria Institute of Applied Mechanics Graz University of TechnologyGrazAustria

This paper presents a combined method to model grain crushing effects with discrete element *** method combines the two most commonly used concepts to model grain crushing in DEM,*** replacement method and the agglomerate method,so that it is both accurate and *** method can be easily *** performance is shown by several DEM simulations of biaxial *** with different crush-abilities are *** simulation results with and without grain crushing are compared and *** change of grain size distribution due to grain crushing is also investigated.

关键词： Grain crushing Discrete element method Granular material

Strength, deformability and permeability of k.k.ritic rock. from the Gotthard base tunnel

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Journal of Rock.Mechanics and Geotechnical Engineering 2023年第9期15卷 2224-2237页

作者： Martin Vogelhuber erich Pimentel Georgios Anagnostou ETH Zurich ZurichSwitzerland

The 57-k. long,new Gotthard Base Tunnel(GBT)crosses over a 1.1-k. long stretch containing k.k.rites,*** rock. which,depending on the degree of tectonisation,may exhibit severe squeezing behaviour upon tunnel *** tunnel stretch was already identified as a k.y problem in the early planning phase,necessitating intensive geological exploration and laboratory investigations over a 14-year period,including research and development in experimental *** laboratory investigations for the GBT provided not only a considerable amount of data about the geotechnical parameters of the k.k.rites,but also valuable information about their basic behaviour and the adequacy of various testing techniques for this type of ***,by using specially designed testing equipment and procedures,it was shown that,(1)conventional rock.mechanics triaxial tests cannot provide reliable results for k.k.rites;(2)the k.k.rites obey the principle of effective stress in Terzaghi’s classical form and consequently it is indispensable to measure the pore pressure during triaxial testing,analogously to the consolidated drained(CD)and consolidated undrained(CU)tests in soil mechanics;(3)the effects of a possible loss of water and desaturation during sampling,transport,storage and preparation of specimens can be successfully mitigated by subjecting the specimens to flow-through before the actual triaxial testing;and,(4)CD tests on partially saturated specimens that are obtained by means of flow-through can provide reliable and reproducible *** saves a significant amount of time,allows a greater number of tests to be performed,and allows results to be obtained more quick.y,which is particularly important for decision-mak.ng during tunnel advance.

关键词： Squeezing Pore pressure Triaxial testing