An exceptionally preserved Late Devonian actinopterygian provides a new model for primitive cranial anatomy in ray-finned fishes

Science.gov (United States)

Giles, Sam; Darras, Laurent; Clément, Gaël; Blieck, Alain; Friedman, Matt

2015-01-01

Actinopterygians (ray-finned fishes) are the most diverse living osteichthyan (bony vertebrate) group, with a rich fossil record. However, details of their earliest history during the middle Palaeozoic (Devonian) ‘Age of Fishes' remains sketchy. This stems from an uneven understanding of anatomy in early actinopterygians, with a few well-known species dominating perceptions of primitive conditions. Here we present an exceptionally preserved ray-finned fish from the Late Devonian (Middle Frasnian, ca 373 Ma) of Pas-de-Calais, northern France. This new genus is represented by a single, three-dimensionally preserved skull. CT scanning reveals the presence of an almost complete braincase along with near-fully articulated mandibular, hyoid and gill arches. The neurocranium differs from the coeval Mimipiscis in displaying a short aortic canal with a distinct posterior notch, long grooves for the lateral dorsal aortae, large vestibular fontanelles and a broad postorbital process. Identification of similar but previously unrecognized features in other Devonian actinopterygians suggests that aspects of braincase anatomy in Mimipiscis are apomorphic, questioning its ubiquity as stand-in for generalized actinopterygian conditions. However, the gill skeleton of the new form broadly corresponds to that of Mimipiscis, and adds to an emerging picture of primitive branchial architecture in crown gnathostomes. The new genus is recovered in a polytomy with Mimiidae and a subset of Devonian and stratigraphically younger actinopterygians, with no support found for a monophyletic grouping of Moythomasia with Mimiidae. PMID:26423841

Hydrodynamical analysis of the effect of fish fins morphology

Science.gov (United States)

Azwadi Che Sidik, Nor; Yen, Tey Wah

2013-12-01

The previous works on the biomechanics of fishes focuses on the locomotion effect of the fish bodies. However, there is quite a insufficiency in unveiling the respective function of fins when the fishes pose statics and exposed to fluid flow. Accordingly, this paper's focus is to investigate the hydrodynamic effect of the fins configuration to the fluid flow of shark-shaped-inspired structure. The drag and lift coefficient is computed for different cases of fish fins addition and configuration. The k-epsilon turbulence model is deployed using finite volume method with the aid of commercial software ANSYS CFX. The finding will demystify some of the functions of the fish's fins in term of their contribution to the hydrodynamic flow around the fishes.

Age estimation of burbot using pectoral fin rays, brachiostegal rays, and otoliths

Science.gov (United States)

Klein, Zachary B.; Terrazas, Marc M.; Quist, Michael C.

2014-01-01

Throughout much of its native distribution, burbot (Lota lota) is a species of conservation concern. Understanding dynamic rate functions is critical for the effective management of sensitive burbot populations, which necessitates accurate and precise age estimates. Managing sensitive burbot populations requires an accurate and precise non-lethal alternative. In an effort to identify a non-lethal ageing structure, we compared the precision of age estimates obtained from otoliths, pectoral fin rays, dorsal fin rays and branchiostegal rays from 208 burbot collected from the Green River drainage, Wyoming. Additionally, we compared the accuracy of age estimates from pectoral fin rays, dorsal fin rays and branchiostegal rays to those of otoliths. Dorsal fin rays were immediately deemed a poor ageing structure and removed from further analysis. Age-bias plots of consensus ages derived from branchiostegal rays and pectoral fin rays were appreciably different from those obtained from otoliths. Exact agreement between readers and reader confidence was highest for otoliths and lowest for branchiostegal rays. Age-bias plots indicated that age estimates obtained from branchiostegal rays and pectoral fin rays were substantially different from age estimates obtained from otoliths. Our results indicate that otoliths provide the most precise age estimates for burbot.

Design, Implementation and Control of a Fish Robot with Undulating Fins

Directory of Open Access Journals (Sweden)

Mohsen Siahmansouri

2011-11-01

Full Text Available Biomimetic robots can potentially perform better than conventional robots in underwater vehicle designing. This paper describes the design of the propulsion system and depth control of a robotic fish. In this study, inspired by knife fish, we have designed and implemented an undulating fin to produce propulsive force. This undulating fin is a segmental anal fin that produces sinusoidal wave to propel the robot. The relationship between the individual fin segment and phase angles with the overall fin trajectory has also been discussed. This propulsive force can be adjusted and directed for fish robot manoeuvre by a mechanical system with two servomotors. These servomotors regulate the direction and depth of swimming. A wireless remote control system is designed to adjust the servomotors which enables us to control revolution, speed and phase differences of neighbor servomotors of fins. Finally, Field trials are conducted in an outdoor pool to demonstrate the relationship between robotic fish speed and fin parameters like phase difference, the number of phase and undulatory amplitude.

Flow-structure Interaction Modeling of a Fish Caudal Fin during Steady Swimming

Science.gov (United States)

Liu, Geng; Geng, Biao; Zheng, Xudong; Xue, Qian; Dong, Haibo

2017-11-01

It's widely thought that the flexibilities of fish fins play critical roles in propulsive performance enhancement (such as thrust augment and efficiency improvement) in nature. In order to explore the formation mechanisms of the fish fin's flexible morphing and its hydrodynamic benefits as well, a high-fidelity flow-structure/membrane interaction modeling of the fish caudal fin is conducted in this work. Following the realistic configuration of the fish caudal fin, a thin membrane supported by a series of beams is constructed. The material properties of the membrane and the beams are reversely determined by the realistic fin morphing obtained from the high-speed videos and the high fidelity flow-structure interaction simulations. With the accurate material property, we investigate the interplay between structure, kinematics and fluid flow in caudal fin propulsion. Detailed analyses on the relationship between the flexural stiffness, fin morphing patterns, hydrodynamic forces and vortex dynamics are then conducted.

A Middle Triassic thoracopterid from China highlights the evolutionary origin of overwater gliding in early ray-finned fishes.

Science.gov (United States)

Xu, Guang-Hui; Zhao, Li-Jun; Shen, Chen-Chen

2015-01-01

Gliding adaptations in thoracopterid flying fishes represent a remarkable case of convergent evolution of overwater gliding strategy with modern exocoetid flying fishes, but the evolutionary origin of this strategy was poorly known in the thoracopterids because of lack of transitional forms. Until recently, all thoracopterids, from the Late Triassic of Austria and Italy and the Middle Triassic of South China, were highly specialized 'four-winged' gliders in having wing-like paired fins and an asymmetrical caudal fin with the lower caudal lobe notably larger than the upper lobe. Here, we show that the new genus Wushaichthys and the previously alleged 'peltopleurid' Peripeltopleurus, from the Middle Triassic (Ladinian, 235-242 Ma) of South China and near the Ladinian/Anisian boundary of southern Switzerland and northern Italy, respectively, represent the most primitive and oldest known thoracopterids. Wushaichthys, the most basal thoracopterid, shows certain derived features of this group in the skull. Peripeltopleurus shows a condition intermediate between Wushaichthys and Thoracopterus in having a slightly asymmetrical caudal fin but still lacking wing-like paired fins. Phylogenetic studies suggest that the evolution of overwater gliding of thoracopterids was gradual in nature; a four-stage adaption following the 'cranial specialization-asymmetrical caudal fin-enlarged paired fins-scale reduction' sequence has been recognized in thoracopterid evolution. Moreover, Wushaichthys and Peripeltopleurus bear hooklets on the anal fin of supposed males, resembling those of modern viviparious teleosts. Early thoracopterids probably had evolved a live-bearing reproductive strategy. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Fatty acid-binding protein genes of the ancient, air-breathing, ray-finned fish, spotted gar (Lepisosteus oculatus).

Science.gov (United States)

Venkatachalam, Ananda B; Fontenot, Quenton; Farrara, Allyse; Wright, Jonathan M

2018-03-01

With the advent of high-throughput DNA sequencing technology, the genomic sequence of many disparate species has led to the relatively new discipline of genomics, the study of genome structure, function and evolution. Much work has been focused on the role of whole genome duplications (WGD) in the architecture of extant vertebrate genomes, particularly those of teleost fishes which underwent a WGD early in the teleost radiation >230 million years ago (mya). Our past work has focused on the fate of duplicated copies of a multigene family coding for the intracellular lipid-binding protein (iLBP) genes in the teleost fishes. To define the evolutionary processes that determined the fate of duplicated genes and generated the structure of extant fish genomes, however, requires comparative genomic analysis with a fish lineage that diverged before the teleost WGD, such as the spotted gar (Lepisosteus oculatus), an ancient, air-breathing, ray-finned fish. Here, we describe the genomic organization, chromosomal location and tissue-specific expression of a subfamily of the iLBP genes that code for fatty acid-binding proteins (Fabps) in spotted gar. Based on this work, we have defined the minimum suite of fabp genes prior to their duplication in the teleost lineages ~230-400 mya. Spotted gar, therefore, serves as an appropriate outgroup, or ancestral/ancient fish, that did not undergo the teleost-specific WGD. As such, analyses of the spatio-temporal regulation of spotted gar genes provides a foundation to determine whether the duplicated fabp genes have been retained in teleost genomes owing to either sub- or neofunctionalization. Copyright © 2017 Elsevier Inc. All rights reserved.

Water flow and fin shape polymorphism in coral reef fishes.

Science.gov (United States)

Binning, Sandra A; Roche, Dominique G

2015-03-01

Water flow gradients have been linked to phenotypic differences and swimming performance across a variety of fish assemblages. However, the extent to which water motion shapes patterns of phenotypic divergence within species remains unknown. We tested the generality of the functional relationship between swimming morphology and water flow by exploring the extent of fin and body shape polymorphism in 12 widespread species from three families (Acanthuridae, Labridae, Pomacentridae) of pectoral-fin swimming (labriform) fishes living across localized wave exposure gradients. The pectoral fin shape of Labridae and Acanthuridae species was strongly related to wave exposure: individuals with more tapered, higher aspect ratio (AR) fins were found on windward reef crests, whereas individuals with rounder, lower AR fins were found on leeward, sheltered reefs. Three of seven Pomacentridae species showed similar trends, and pectoral fin shape was also strongly related to wave exposure in pomacentrids when fin aspect ratios of three species were compared across flow habitats at very small spatial scales (fish body fineless ratio across habitats or depths. Contrary to our predictions, there was no pattern relating species' abundances to polymorphism across habitats (i.e., abundance was not higher at sites where morphology is better adapted to the environment). This suggests that there are behavioral and/or physiological mechanisms enabling some species to persist across flow habitats in the absence of morphological differences. We suggest that functional relationships between swimming morphology and water flow not only structure species assemblages, but are yet another important variable contributing to phenotypic differences within species. The close links between fin shape polymorphism and local water flow conditions appear to be important for understanding species' distributions as well as patterns of diversification across environmental gradients.

Hox gene clusters in the Indonesian coelacanth, Latimeria menadoensis

Science.gov (United States)

Koh, Esther G. L.; Lam, Kevin; Christoffels, Alan; Erdmann, Mark V.; Brenner, Sydney; Venkatesh, Byrappa

2003-01-01

The Hox genes encode transcription factors that play a key role in specifying body plans of metazoans. They are organized into clusters that contain up to 13 paralogue group members. The complex morphology of vertebrates has been attributed to the duplication of Hox clusters during vertebrate evolution. In contrast to the single Hox cluster in the amphioxus (Branchiostoma floridae), an invertebrate-chordate, mammals have four clusters containing 39 Hox genes. Ray-finned fishes (Actinopterygii) such as zebrafish and fugu possess more than four Hox clusters. The coelacanth occupies a basal phylogenetic position among lobe-finned fishes (Sarcopterygii), which gave rise to the tetrapod lineage. The lobe fins of sarcopterygians are considered to be the evolutionary precursors of tetrapod limbs. Thus, the characterization of Hox genes in the coelacanth should provide insights into the origin of tetrapod limbs. We have cloned the complete second exon of 33 Hox genes from the Indonesian coelacanth, Latimeria menadoensis, by extensive PCR survey and genome walking. Phylogenetic analysis shows that 32 of these genes have orthologs in the four mammalian HOX clusters, including three genes (HoxA6, D1, and D8) that are absent in ray-finned fishes. The remaining coelacanth gene is an ortholog of hoxc1 found in zebrafish but absent in mammals. Our results suggest that coelacanths have four Hox clusters bearing a gene complement more similar to mammals than to ray-finned fishes, but with an additional gene, HoxC1, which has been lost during the evolution of mammals from lobe-finned fishes. PMID:12547909

Correlated evolution of body and fin morphology in the cichlid fishes.

Science.gov (United States)

Feilich, Kara L

2016-10-01

Body and fin shapes are chief determinants of swimming performance in fishes. Different configurations of body and fin shapes can suit different locomotor specializations. The success of any configuration is dependent upon the hydrodynamic interactions between body and fins. Despite the importance of body-fin interactions for swimming, there are few data indicating whether body and fin configurations evolve in concert, or whether these structures vary independently. The cichlid fishes are a diverse family whose well-studied phylogenetic relationships make them ideal for the study of macroevolution of ecomorphology. This study measured body, and caudal and median fin morphology from radiographs of 131 cichlid genera, using morphometrics and phylogenetic comparative methods to determine whether these traits exhibit correlated evolution. Partial least squares canonical analysis revealed that body, caudal fin, dorsal fin, and anal fin shapes all exhibited strong correlated evolution consistent with locomotor ecomorphology. Major patterns included the evolution of deep body profiles with long fins, suggestive of maneuvering specialization; and the evolution of narrow, elongate caudal peduncles with concave tails, a combination that characterizes economical cruisers. These results demonstrate that body shape evolution does not occur independently of other traits, but among a suite of other morphological changes that augment locomotor specialization. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

Note: Dynamic analysis of a robotic fish motion with a caudal fin with vertical phase differences

Science.gov (United States)

Yun, Dongwon; Kim, Kyung-Soo; Kim, Soohyun; Kyung, Jinho; Lee, Sunghwi

2013-03-01

In this paper, a robotic fish with a caudal fin with vertical phase differences is studied, especially focusing on the energy consumption. Energies for thrusting a conventional robotic fish and one with caudal fin with vertical phase differences are obtained and compared each other. It is shown that a robotic fish with a caudal fin with vertical phase differences can save more energy, which implies the efficient thrusting via a vertically waving caudal fin.

Bioinspiration from fish for smart material design and function

International Nuclear Information System (INIS)

Lauder, G V; Madden, P G A; Tangorra, J L; Anderson, E; Baker, T V

2011-01-01

Fish are a potentially rich source of inspiration for the design of smart materials. Fish exemplify the use of flexible materials to generate forces during locomotion, and a hallmark of fish functional design is the use of body and fin deformation to power propulsion and maneuvering. As a result of nearly 500 million years of evolutionary experimentation, fish design has a number of interesting features of note to materials engineers. In this paper we first provide a brief general overview of some key features of the mechanical design of fish, and then focus on two key properties of fish: the bilaminar mechanical design of bony fish fin rays that allows active muscular control of curvature, and the role of body flexibility in propulsion. After describing the anatomy of bony fish fin rays, we provide new data on their mechanical properties. Three-point bending tests and measurement of force inputs to and outputs from the fin rays show that these fin rays are effective displacement transducers. Fin rays in different regions of the fin differ considerably in their material properties, and in the curvature produced by displacement of one of the two fin ray halves. The mean modulus for the proximal (basal) region of the fin rays was 1.34 GPa, but this varied from 0.24 to 3.7 GPa for different fin rays. The distal fin region was less stiff, and moduli for the different fin rays measured varied from 0.11 to 0.67 GPa. These data are similar to those for human tendons (modulus around 0.5 GPa). Analysis of propulsion using flexible foils controlled using a robotic flapping device allows investigation of the effect of altering flexural stiffness on swimming speed. Flexible foils with the leading edge moved in a heave show a distinct peak in propulsive performance, while the addition of pitch input produces a broad plateau where the swimming speed is relatively unaffected by the flexural stiffness. Our understanding of the material design of fish and the control of tissue

87Sr/86Sr isotope ratio analysis by laser ablation MC-ICP-MS in scales, spines, and fin rays as a nonlethal alternative to otoliths for reconstructing fish life history

Science.gov (United States)

Willmes, Malte; Glessner, Justin J. G.; Carleton, Scott A.; Gerrity, Paul C.; Hobbs, James A.

2016-01-01

Strontium isotope ratios (87Sr/86Sr) in otoliths are a well-established tool to determine origins and movement patterns of fish. However, otolith extraction requires sacrificing fish, and when working with protected or endangered species, the use of nonlethal samples such as scales, spines, and fin rays is preferred. Unlike otoliths that are predominantly aragonite, these tissues are composed of biological apatite. Laser ablation multicollector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) analysis of biological apatite can induce significant interference on mass 87, causing inaccurate 87Sr/86Sr measurements. To quantify this interference, we applied LA-MC-ICP-MS to three marine samples (white seabass (Atractoscion nobilis) otolith; green sturgeon (Acipenser medirostris) pectoral fin ray; salmon shark (Lamna ditropis) tooth), and freshwater walleye (Sander vitreus) otoliths, scales, and spines). Instrument conditions that maximize signal intensity resulted in elevated 87Sr/86Sr isotope ratios in the bioapatite samples, related to a polyatomic interference (40Ca31P16O, 40Ar31P16O). Retuning instrument conditions to reduce oxide levels removed this interference, resulting in accurate 87Sr/86Sr ratios across all tissue samples. This method provides a novel, nonlethal alternative to otolith analysis to reconstruct fish life histories.

DNR 100K Lakes - Fishing in the Neighborhood (FiN) Ponds

Data.gov (United States)

Minnesota Department of Natural Resources — This layer represents ponds included in DNR's Fishing in the Neighborhood (FiN) program. This program establishes local ponds to provide urban fishing opportunities...

Actuation of a robotic fish caudal fin for low reaction torque

Science.gov (United States)

Yun, Dongwon; Kim, Kyung-Soo; Kim, Soohyun; Kyung, Jinho; Lee, Sunghee

2011-07-01

In this paper, a novel caudal fin for actuating a robotic fish is presented. The proposed caudal fin waves in a vertical direction with a specific spatial shape, which is determined by a so-called shape factor. For a specific shape factor, a traveling wave with a vertical phase difference is formed on a caudal fin during fin motion. It will be shown by the analysis that the maximum reaction torque at the joint of a caudal fin varies depending on the shape factors. Compared with a conventional plate type caudal fin, the proposed fin with a shape factor of 2π can eliminate the reaction torque perfectly, while keeping the propulsion force unchanged. The benefits of the proposed fin will be demonstrated by experiments.

Evolutionary Trends of the Pharyngeal Dentition in Cypriniformes (Actinopterygii: Ostariophysi)

OpenAIRE

Pasco-Viel, Emmanuel; Charles, Cyril; Chevret, Pascale; Semon, Marie; Tafforeau, Paul; Viriot, Laurent; Laudet, Vincent

2010-01-01

Background : The fish order Cypriniformes is one of the most diverse ray-finned fish groups in the world with more than 3000 recognized species. Cypriniformes are characterized by a striking distribution of their dentition: namely the absence of oral teeth and presence of pharyngeal teeth on the last gill arch (fifth ceratobranchial). Despite this limited localisation, the diversity of tooth patterns in Cypriniformes is astonishing. Here we provide a further description of this diversity usin...

Bio-inspired flexible joints with passive feathering for robotic fish pectoral fins.

Science.gov (United States)

Behbahani, Sanaz Bazaz; Tan, Xiaobo

2016-05-04

In this paper a novel flexible joint is proposed for robotic fish pectoral fins, which enables a swimming behavior emulating the fin motions of many aquatic animals. In particular, the pectoral fin operates primarily in the rowing mode, while undergoing passive feathering during the recovery stroke to reduce hydrodynamic drag on the fin. The latter enables effective locomotion even with symmetric base actuation during power and recovery strokes. A dynamic model is developed to facilitate the understanding and design of the joint, where blade element theory is used to calculate the hydrodynamic forces on the pectoral fins, and the joint is modeled as a paired torsion spring and damper. Experimental results on a robotic fish prototype are presented to illustrate the effectiveness of the joint mechanism, validate the proposed model, and indicate the utility of the proposed model for the optimal design of joint depth and stiffness in achieving the trade-off between swimming speed and mechanical efficiency.

A new grenadier of the genus Hymenocephalus from Tosa Bay, southern Japan (Actinopterygii: Gadiformes: Macrouridae)

DEFF Research Database (Denmark)

Nakayama, Naohide; Endo, Hiromitsu; Schwarzhans, Werner

2015-01-01

Hymenocephalus yamasakiorum, a new species of grenadier fishes, is described from a single specimen collected from Tosa Bay off Aki, Kochi, Japan, at a depth of 320–400 m. The species is distinguished from its 26 known congeners in having the following combination of features: pelvic-fin rays nine......; pectoral-fin rays i16–i17; first dorsal-fin rays II, 10; chin barbel 55 % of head length (HL), its tip extending beyond the hind margin of orbit when laid back; snout moderately high, not depressed, length 28 % HL; orbit diameter 33 % HL; interorbital width 24 % HL; gill rakers on first arch (outer...

Age at maturity of Mediterranean marine fishes

Directory of Open Access Journals (Sweden)

A. C. TSIKLIRAS

2014-07-01

Full Text Available In this review we collected data on the age at maturity (tm and maximum reported age (tmax for 235 stocks of Mediterranean marine fishes, belonging to 82 species, 37 families, 12 orders and 2 classes (Actinopterygii and Elasmobranchii. Among Actinopterygii (mean tm ± SD = 2.20 ± 1.43 y, n = 215, tm ranged from 0.3 y, for the common goby Pomatoschistus microps, to 12 y, for dusky grouper Epinephelus marginatus, while among Elasmobranchii (mean tm ± SD = 5.94 ± 2.47 y, n = 20, tm ranged between 2.7 y, for brown ray Raja miraletus, and 12 y for picked dogfish Squalus acanthias. Overall, the tmax ranged between 1 y, for transparent goby Aphia minuta, and 70 y, for wreckfish Polyprion americanus. The mean tmax of Actinopterygii (tmax ± SD = 10.14 ± 9.42 y was lower than that of Elasmobranchii (tmax ± SD = 14.05 ± 8.47 y. The tm exhibited a strong positive linear relation with tmax for both Actinopterygii (logtm = 0.58 ´ logtmax – 0.25, r2 = 0.51, P < 0.001 and Elasmobranchii (logtm = 0.67 ´ logtmax – 0.006, r2 = 0.51, P = 0.007. The mean tm/tmax did not differ significantly with sex within Actinopterygii (ANOVA: F = 0.27, P = 0.60, n = 90; females: mean ± SD = 0.276 ± 0.143; males: mean ± SD = 0.265 ± 0.138 and Elasmobranchii (ANOVA: F = 1.44, P = 0.25, n = 10; females: mean ± SD = 0.499 ± 0.166; males: mean ± SD = 0.418 ± 0.133. Finally, the dimensionless ratio tm/tmax was significantly lower (ANOVA: F = 31.04, P < 0.001 for Actinopterygii (mean ± SD = 0.270 ± 0.135, n = 180 than for Elasmobranchii, (mean ± SD = 0.458 ± 0.152, n = 20, when stocks with combined sexes were excluded from the analysis.

Fish robotics and hydrodynamics

Science.gov (United States)

Lauder, George

2010-11-01

Studying the fluid dynamics of locomotion in freely-swimming fishes is challenging due to difficulties in controlling fish behavior. To provide better control over fish-like propulsive systems we have constructed a variety of fish-like robotic test platforms that range from highly biomimetic models of fins, to simple physical models of body movements during aquatic locomotion. First, we have constructed a series of biorobotic models of fish pectoral fins with 5 fin rays that allow detailed study of fin motion, forces, and fluid dynamics associated with fin-based locomotion. We find that by tuning fin ray stiffness and the imposed motion program we can produce thrust both on the fin outstroke and instroke. Second, we are using a robotic flapping foil system to study the self-propulsion of flexible plastic foils of varying stiffness, length, and trailing edge shape as a means of investigating the fluid dynamic effect of simple changes in the properties of undulating bodies moving through water. We find unexpected non-linear stiffness-dependent effects of changing foil length on self-propelled speed, and as well as significant effects of trailing edge shape on foil swimming speed.

Evaluation of Artificial Caudal Fin for Fish Robot with Two Joints by Using Three-Dimensional Fluid-Structure Simulation

Directory of Open Access Journals (Sweden)

Yogo Takada

2013-01-01

Full Text Available A fish robot with image sensors is useful to research for underwater creatures such as fish. However, the propulsion velocity of a fish robot is very slow compared with live fish. It is necessary to swim at a speed several times faster than the speed of the current robots for various usages. Therefore, we are searching for the method of making the robot swim fast. The simulation before making the robot is important. We have made the computational simulation program of three-dimensional fluid-structure analysis. The flow around the caudal fin can be examined by analyzing the fin as an elastic body. We compared the results of numerical analysis with the results of PIV measurement. Both were agreed well. Because the performance of a fish robot with two joints is better than that of a fish robot with one joint, we searched for an excellent fin for the fish robot with two joints by using CFD. We confirmed that the swimming performance of a fish robot becomes very good when the caudal fin is rigid except for the root of the fin which is comparatively flexible.

Musculoskeletal anatomy of the pelvic fin of Polypterus: implications for phylogenetic distribution and homology of pre- and postaxial pelvic appendicular muscles.

Science.gov (United States)

Molnar, Julia L; Johnston, Peter S; Esteve-Altava, Borja; Diogo, Rui

2017-04-01

As a member of the most basal clade of extant ray-finned fishes (actinopterygians) and of one of the most basal clades of osteichthyans (bony fishes + tetrapods), Polypterus can provide insights into the ancestral anatomy of both ray-finned and lobe-finned fishes, including those that gave rise to tetrapods. The pectoral fin of Polypterus has been well described but, surprisingly, neither the bones nor the muscles of the pelvic fin are well known. We stained and dissected the pelvic fin of Polypterus senegalus and Polypterus delhezi to offer a detailed description of its musculoskeletal anatomy. In addition to the previously described adductor and abductor muscles, we found preaxial and postaxial muscles similar to those in the pectoral fin of members of this genus. The presence of pre- and postaxial muscles in both the pectoral and pelvic fins of Polypterus, combined with recent descriptions of similar muscles in the lobe-finned fishes Latimeria and Neoceratodus, suggests that they were present in the most recent common ancestor of bony fishes. These results have crucial implications for the evolution of appendicular muscles in both fish and tetrapods. © 2016 Anatomical Society.

The Species and Origin of Shark Fins in Taiwan's Fishing Ports, Markets, and Customs Detention: A DNA Barcoding Analysis.

Science.gov (United States)

Chuang, Po-Shun; Hung, Tzu-Chiao; Chang, Hung-An; Huang, Chien-Kang; Shiao, Jen-Chieh

2016-01-01

The increasing consumption of shark products, along with the shark's fishing vulnerabilities, has led to the decrease in certain shark populations. In this study we used a DNA barcoding method to identify the species of shark landings at fishing ports, shark fin products in retail stores, and shark fins detained by Taiwan customs. In total we identified 23, 24, and 14 species from 231 fishing landings, 316 fin products, and 113 detained shark fins, respectively. All the three sample sources were dominated by Prionace glauca, which accounted for more than 30% of the collected samples. Over 60% of the species identified in the fin products also appeared in the port landings, suggesting the domestic-dominance of shark fin products in Taiwan. However, international trade also contributes a certain proportion of the fin product markets, as four species identified from the shark fin products are not found in Taiwan's waters, and some domestic-available species were also found in the customs-detained sample. In addition to the species identification, we also found geographical differentiation in the cox1 gene of the common thresher sharks (Alopias vulpinus), the pelagic thresher shark (A. pelagicus), the smooth hammerhead shark (Sphyrna zygaena), and the scalloped hammerhead shark (S. lewini). This result might allow fishing authorities to more effectively trace the origins as well as enforce the management and conservation of these sharks.

The Species and Origin of Shark Fins in Taiwan's Fishing Ports, Markets, and Customs Detention: A DNA Barcoding Analysis.

Directory of Open Access Journals (Sweden)

Po-Shun Chuang

Full Text Available The increasing consumption of shark products, along with the shark's fishing vulnerabilities, has led to the decrease in certain shark populations. In this study we used a DNA barcoding method to identify the species of shark landings at fishing ports, shark fin products in retail stores, and shark fins detained by Taiwan customs. In total we identified 23, 24, and 14 species from 231 fishing landings, 316 fin products, and 113 detained shark fins, respectively. All the three sample sources were dominated by Prionace glauca, which accounted for more than 30% of the collected samples. Over 60% of the species identified in the fin products also appeared in the port landings, suggesting the domestic-dominance of shark fin products in Taiwan. However, international trade also contributes a certain proportion of the fin product markets, as four species identified from the shark fin products are not found in Taiwan's waters, and some domestic-available species were also found in the customs-detained sample. In addition to the species identification, we also found geographical differentiation in the cox1 gene of the common thresher sharks (Alopias vulpinus, the pelagic thresher shark (A. pelagicus, the smooth hammerhead shark (Sphyrna zygaena, and the scalloped hammerhead shark (S. lewini. This result might allow fishing authorities to more effectively trace the origins as well as enforce the management and conservation of these sharks.

Non-lethal approach identifies variability of δ15N values in the fin rays of Atlantic Goliath Grouper, Epinephelus itajara

Directory of Open Access Journals (Sweden)

Orian E. Tzadik

2015-06-01

Full Text Available The Atlantic Goliath Grouper, Epinephelus itajara, is critically endangered throughout its range but has begun to show initial signs of recovery in Florida state waters. As the population continues to rebound, researchers face a pressing need to fill the knowledge gaps about this iconic species. Here, we examined the δ15N isotopic records in fin rays collected from Atlantic Goliath Grouper, and related changes of isotopic ratios over time to life history characteristics. Fin-ray analysis was used as a non-lethal technique to sample individuals from two locations at similar latitudes from the west and east coasts of Florida, USA. δ15N data were acquired by mechanically separating the annuli of each fin ray and then analyzing the material in an Irradiance Elemental Analyzer Mass Spectrometer. The δ15N values were consistent among individuals within populations from each coast of Florida, and mirrored the expected changes over the lives of the fish. Overall, differences were found between δ15N values at juvenile life history phases versus adult phases, but the patterns associated with these differences were unique to each coastal group. We demonstrated, for the first time, that δ15N values from fin rays can be used to assess the life histories of Atlantic Goliath Grouper. The non-lethal strategies outlined here can be used to acquire information essential to the management of species of concern, such as those that are threatened or endangered.

Comparative energetics of the 5 fish classes on the basis of dynamic energy budgets

Science.gov (United States)

Kooijman, Sebastiaan A. L. M.; Lika, Konstadia

2014-11-01

The eco-physiology of taxa in an evolutionary context can best be studied by a comparison of parameter values of the energy budget that accounts for the inter-relationships of all endpoints of energy allocation. To this end, the parameters of the standard Dynamic Energy Budget (DEB) model have been estimated for 64 fish species from all 5 fish classes. The values are compared with those of the whole collection of over 300 species from most large animal phyla. The goodness of fit was very high, but the data were rather incomplete, compared with the energy balance for full life cycles. Metabolic acceleration, where maximum specific assimilation and energy conductance increase with length between birth and metabolic metamorphosis, seems to be confined, among fish, to some species of ray-finned fish and seems to have evolved independently several times in this taxon. We introduce a new altriciality index, i.e. the ratio of the maturity levels at puberty and birth, and conclude that ray-finned fish are more altricial, and cartilaginous fish are more precocial than typical animals. Fish allocate more to reproduction than typical animals. Parameter estimates show that 66% of the fish species considered invest less in reproduction than the value that would maximize the reproduction rate of fully grown individuals. By comparison, 85% of all the animal species in the collection do so. Consistent with theoretical expectations, allocation to reproduction and maturity at birth increase with cubed (ultimate structural) length, and reserve capacity with length for non-ray-finned fish, with the consequence that reproduction rate decreases with length. Ray-finned fish, however, have a maturity at birth and a reserve capacity almost independent of length, and a reproduction rate that increases with cubed length. Reserve capacity tends to increase with ultimate length for non-accelerating ray-finned fish, but not for accelerating species. Reproduction rate decreases inter

The Species and Origin of Shark Fins in Taiwan’s Fishing Ports, Markets, and Customs Detention: A DNA Barcoding Analysis

Science.gov (United States)

Chuang, Po-Shun; Hung, Tzu-Chiao; Chang, Hung-An; Huang, Chien-Kang; Shiao, Jen-Chieh

2016-01-01

The increasing consumption of shark products, along with the shark’s fishing vulnerabilities, has led to the decrease in certain shark populations. In this study we used a DNA barcoding method to identify the species of shark landings at fishing ports, shark fin products in retail stores, and shark fins detained by Taiwan customs. In total we identified 23, 24, and 14 species from 231 fishing landings, 316 fin products, and 113 detained shark fins, respectively. All the three sample sources were dominated by Prionace glauca, which accounted for more than 30% of the collected samples. Over 60% of the species identified in the fin products also appeared in the port landings, suggesting the domestic-dominance of shark fin products in Taiwan. However, international trade also contributes a certain proportion of the fin product markets, as four species identified from the shark fin products are not found in Taiwan’s waters, and some domestic-available species were also found in the customs-detained sample. In addition to the species identification, we also found geographical differentiation in the cox1 gene of the common thresher sharks (Alopias vulpinus), the pelagic thresher shark (A. pelagicus), the smooth hammerhead shark (Sphyrna zygaena), and the scalloped hammerhead shark (S. lewini). This result might allow fishing authorities to more effectively trace the origins as well as enforce the management and conservation of these sharks. PMID:26799827

Design and dynamic modeling of electrorheological fluid-based variable-stiffness fin for robotic fish

Science.gov (United States)

Bazaz Behbahani, Sanaz; Tan, Xiaobo

2017-08-01

Fish actively control their stiffness in different swimming conditions. Inspired by such an adaptive behavior, in this paper we study the design, prototyping, and dynamic modeling of compact, tunable-stiffness fins for robotic fish, where electrorheological (ER) fluid serves as the enabling element. A multi-layer composite fin with an ER fluid core is prototyped and utilized to investigate the influence of electrical field on its performance. Hamilton's principle is used to derive the dynamic equations of motion of the flexible fin, and Lighthill's large-amplitude elongated-body theory is adopted to estimate the hydrodynamic force when the fin undergoes base-actuated rotation. The dynamic equations are then discretized using the finite element method, to obtain an approximate numerical solution. Experiments are conducted on the prototyped flexible ER fluid-filled beam for parameter identification and validation of the proposed model, and for examining the effectiveness of electrically controlled stiffness tuning. In particular, it is found that the natural frequency is increased by almost 40% when the applied electric field changes from 0 to 1.5× {10}6 {{V}} {{{m}}}-1.

Fins improve the swimming performance of fish sperm: a hydrodynamic analysis of the Siberian sturgeon Acipenser baerii.

Science.gov (United States)

Gillies, Eric A; Bondarenko, Volodymyr; Cosson, Jacky; Pacey, Allan A

2013-02-01

The flagella of sturgeon sperm have an ultrastructure comprising paddle-like fins extending along most of their length. These fins are seen in several other marine and freshwater fish. The sperm of these fish are fast swimmers and are relatively short lived: it is therefore tempting to think of these fins as having evolved for hydrodynamic advantage, but the actual advantage they impart, at such a small length scale and slow speed, is unclear. The phrase "the fins improve hydrodynamic efficiency" is commonly found in biological literature, yet little hydrodynamic analysis has previously been used to support such conjectures. In this paper, we examine various hydrodynamic models of sturgeon sperm and investigate both swimming velocity and energy expenditure. All of the models indicate a modest hydrodynamic advantage of finned sperm, in both straight line swimming speed and a hydrodynamic efficiency measure. We find a hydrodynamic advantage for a flagellum with fins, over one without fins, of the order of 15-20% in straight line propulsive velocity and 10-15% in a hydrodynamic efficiency measure. Copyright © 2012 Wiley Periodicals, Inc.

A Biologically Derived Pectoral Fin for Yaw Turn Manoeuvres

Directory of Open Access Journals (Sweden)

Jonah R. Gottlieb

2010-01-01

Full Text Available A bio-robotic fin has been developed that models the pectoral fin of the bluegill sunfish as the fish turned to avoid an obstacle. This work involved biological studies of the sunfish fin, the development of kinematic models of the motions of the fin's rays, CFD based predictions of the 3D forces and flows created by the fin, and the implementation of simplified models of the fin's kinematics and mechanical properties in a physical model. The resulting robotic fin produced the forces and flows that drove the manoeuvre and had a sufficiently high number of degrees of freedom to create a variety of non-biologically derived motions. The results indicate that for robotic fins to produce a level of performance on par with biological fins, both the kinematics and the mechanical properties of the biological fin must be modelled well.

Genetic characterization of fin fish species from the Warri River at ...

African Journals Online (AJOL)

SAM

2014-07-02

Jul 2, 2014 ... Genetic characterization of fin fish species from the. Warri River at Ubeji, Niger Delta, Nigeria. Asagbra ..... Prochilodus lineatus, Salminus brasiliensis and Steindachneridion scripta) from Uruguay River basin. Brazilian Archives Biol. Tech. 49(4):589-598. Saad YM, Shaden-Hanafi M, Essa MA, Guerges AA ...

The fishes of Genome 10K

KAUST Repository

Bernardi, Giacomo

2012-09-01

The Genome 10K project aims to sequence the genomes of 10,000 vertebrates, representing approximately one genome for each vertebrate genus. Since fishes (cartilaginous fishes, ray-finned fishes and lobe-finned fishes) represent more than 50% of extant vertebrates, it is planned to target 4,000 fish genomes. At present, nearly 60 fish genomes are being sequenced at various public funded labs, and under a Genome 10K and BGI pilot project. An additional 100 fishes have been identified for sequencing in the next phase of Genome 10K project. © 2012 Elsevier B.V.

The fishes of Genome 10K

KAUST Repository

Bernardi, Giacomo; Wiley, Edward O.; Mansour, Hicham; Miller, Michael R.; Ortí , Guillermo; Haussler, David H.; O'Brien, Stephen J O; Ryder, Oliver A.; Venkatesh, Byrappa

2012-01-01

The Genome 10K project aims to sequence the genomes of 10,000 vertebrates, representing approximately one genome for each vertebrate genus. Since fishes (cartilaginous fishes, ray-finned fishes and lobe-finned fishes) represent more than 50% of extant vertebrates, it is planned to target 4,000 fish genomes. At present, nearly 60 fish genomes are being sequenced at various public funded labs, and under a Genome 10K and BGI pilot project. An additional 100 fishes have been identified for sequencing in the next phase of Genome 10K project. © 2012 Elsevier B.V.

Reconstructing pectoral appendicular muscle anatomy in fossil fish and tetrapods over the fins-to-limbs transition.

Science.gov (United States)

Molnar, Julia L; Diogo, Rui; Hutchinson, John R; Pierce, Stephanie E

2018-05-01

The question of how tetrapod limbs evolved from fins is one of the great puzzles of evolutionary biology. While palaeontologists, developmental biologists, and geneticists have made great strides in explaining the origin and early evolution of limb skeletal structures, that of the muscles remains largely unknown. The main reason is the lack of consensus about appendicular muscle homology between the closest living relatives of early tetrapods: lobe-finned fish and crown tetrapods. In the light of a recent study of these homologies, we re-examined osteological correlates of muscle attachment in the pectoral girdle, humerus, radius, and ulna of early tetrapods and their close relatives. Twenty-nine extinct and six extant sarcopterygians were included in a meta-analysis using information from the literature and from original specimens, when possible. We analysed these osteological correlates using parsimony-based character optimization in order to reconstruct muscle anatomy in ancestral lobe-finned fish, tetrapodomorph fish, stem tetrapods, and crown tetrapods. Our synthesis revealed that many tetrapod shoulder muscles probably were already present in tetrapodomorph fish, while most of the more-distal appendicular muscles either arose later from largely undifferentiated dorsal and ventral muscle masses or did not leave clear correlates of attachment in these taxa. Based on this review and meta-analysis, we postulate a stepwise sequence of specific appendicular muscle acquisitions, splits, and fusions that led from the ancestral sarcopterygian pectoral fin to the ancestral tetrapod forelimb. This sequence largely agrees with previous hypotheses based on palaeontological and comparative work, but it is much more comprehensive in terms of both muscles and taxa. Combined with existing information about the skeletal system, our new synthesis helps to illuminate the genetic, developmental, morphological, functional, and ecological changes that were key components of the

Modeling of robotic fish propelled by an ionic polymer-metal composite caudal fin

Science.gov (United States)

Chen, Zheng; Shatara, Stephan; Tan, Xiaobo

2009-03-01

In this paper, a model is proposed for a biomimetic robotic fish propelled by an ionic polymer metal composite (IPMC) actuator with a rigid passive fin at the end. The model incorporates both IPMC actuation dynamics and the hydrodynamics, and predicts the steady-state speed of the robot under a periodic actuation voltage. Experimental results have shown that the proposed model can predict the fish motion for different tail dimensions. Since its parameters are expressed in terms of physical properties and geometric dimensions, the model is expected to be instrumental in optimal design of the robotic fish.

Structure and mechanical implications of the pectoral fin skeleton in the Longnose Skate (Chondrichthyes, Batoidea).

Science.gov (United States)

Huang, Wei; Hongjamrassilp, Watcharapong; Jung, Jae-Young; Hastings, Philip A; Lubarda, Vlado A; McKittrick, Joanna

2017-03-15

Animal propulsion systems are believed to show high energy and mechanical efficiency in assisting movement compared to artificial designs. As an example, batoid fishes have very light cartilaginous skeletons that facilitate their elegant swimming via enlarged wing-like pectoral fins. The aim of this work is to illustrate the hierarchical structure of the pectoral fin of a representative batoid, the Longnose Skate (Raja rhina), and explain the mechanical implications of its structural design. At the macro level, the pectoral fins are comprised of radially oriented fin rays, formed by staggered mineralized skeletal elements stacked end-to-end. At the micro level, the midsection of each radial element is composed of three mineralized components, which consist of discrete segments (tesserae) that are mineralized cartilage and embedded in unmineralized cartilage. The radial elements are wrapped with aligned, unmineralized collagen fibers. This is the first report of the detailed structure of the ray elements, including the observation of a 3-chain mineralized tesserae. Structural analyses demonstrate that this configuration enhances stiffness in multiple directions. A two-dimensional numerical model based on the morphological analysis demonstrated that the tessera structure helps distributing shear, tensile and compressive stress more ideally, which can better support both lift and thrust forces when swimming without losing flexibility. Batoid fishes have very light cartilaginous skeletons that facilitate their elegant swimming by applying their enlarged wing-like pectoral fins. Previous studies have shown structural features and mechanical properties of the mineralized cartilage skeleton in various batoid fishes. However, the details of the pectoral fin structure at different length scales, as well as the relationship between the mechanical properties and structural design remains unknown. The present work illustrates the hierarchical structure of the pectoral fin of

Parametric study of the swimming performance of a fish robot propelled by a flexible caudal fin

Energy Technology Data Exchange (ETDEWEB)

Low, K H; Chong, C W, E-mail: mkhlow@ntu.edu.s, E-mail: ch0018ee@ntu.edu.s [School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798 (Singapore)

2010-12-15

In this paper, we aim to study the swimming performance of fish robots by using a statistical approach. A fish robot employing a carangiform swimming mode had been used as an experimental platform for the performance study. The experiments conducted aim to investigate the effect of various design parameters on the thrust capability of the fish robot with a flexible caudal fin. The controllable parameters associated with the fin include frequency, amplitude of oscillation, aspect ratio and the rigidity of the caudal fin. The significance of these parameters was determined in the first set of experiments by using a statistical approach. A more detailed parametric experimental study was then conducted with only those significant parameters. As a result, the parametric study could be completed with a reduced number of experiments and time spent. With the obtained experimental result, we were able to understand the relationship between various parameters and a possible adjustment of parameters to obtain a higher thrust. The proposed statistical method for experimentation provides an objective and thorough analysis of the effects of individual or combinations of parameters on the swimming performance. Such an efficient experimental design helps to optimize the process and determine factors that influence variability.

Parametric study of the swimming performance of a fish robot propelled by a flexible caudal fin.

Science.gov (United States)

Low, K H; Chong, C W

2010-12-01

In this paper, we aim to study the swimming performance of fish robots by using a statistical approach. A fish robot employing a carangiform swimming mode had been used as an experimental platform for the performance study. The experiments conducted aim to investigate the effect of various design parameters on the thrust capability of the fish robot with a flexible caudal fin. The controllable parameters associated with the fin include frequency, amplitude of oscillation, aspect ratio and the rigidity of the caudal fin. The significance of these parameters was determined in the first set of experiments by using a statistical approach. A more detailed parametric experimental study was then conducted with only those significant parameters. As a result, the parametric study could be completed with a reduced number of experiments and time spent. With the obtained experimental result, we were able to understand the relationship between various parameters and a possible adjustment of parameters to obtain a higher thrust. The proposed statistical method for experimentation provides an objective and thorough analysis of the effects of individual or combinations of parameters on the swimming performance. Such an efficient experimental design helps to optimize the process and determine factors that influence variability.

Parametric study of the swimming performance of a fish robot propelled by a flexible caudal fin

International Nuclear Information System (INIS)

Low, K H; Chong, C W

2010-01-01

In this paper, we aim to study the swimming performance of fish robots by using a statistical approach. A fish robot employing a carangiform swimming mode had been used as an experimental platform for the performance study. The experiments conducted aim to investigate the effect of various design parameters on the thrust capability of the fish robot with a flexible caudal fin. The controllable parameters associated with the fin include frequency, amplitude of oscillation, aspect ratio and the rigidity of the caudal fin. The significance of these parameters was determined in the first set of experiments by using a statistical approach. A more detailed parametric experimental study was then conducted with only those significant parameters. As a result, the parametric study could be completed with a reduced number of experiments and time spent. With the obtained experimental result, we were able to understand the relationship between various parameters and a possible adjustment of parameters to obtain a higher thrust. The proposed statistical method for experimentation provides an objective and thorough analysis of the effects of individual or combinations of parameters on the swimming performance. Such an efficient experimental design helps to optimize the process and determine factors that influence variability.

Genetic Architecture of the Variation in Male-Specific Ossified Processes on the Anal Fins of Japanese Medaka.

Science.gov (United States)

Kawajiri, Maiko; Fujimoto, Shingo; Yoshida, Kohta; Yamahira, Kazunori; Kitano, Jun

2015-10-28

Traits involved in reproduction evolve rapidly and show great diversity among closely related species. However, the genetic mechanisms that underlie the diversification of courtship traits are mostly unknown. Japanese medaka fishes (Oryzias latipes) use anal fins to attract females and to grasp females during courtship; the males have longer anal fins with male-specific ossified papillary processes on the fin rays. However, anal fin morphology varies between populations: the southern populations tend to have longer anal fins and more processes than the northern populations. In the present study, we conducted quantitative trait locus (QTL) mapping to investigate the genetic architecture underlying the variation in the number of papillary processes of Japanese medaka fish and compared the QTL with previously identified QTL controlling anal fin length. First, we found that only a few QTL were shared between anal fin length and papillary process number. Second, we found that the numbers of papillary processes on different fin rays often were controlled by different QTL. Finally, we produced another independent cross and found that some QTL were repeatable between the two crosses, whereas others were specific to only one cross. These results suggest that variation in the number of papillary processes is polygenic and controlled by QTL that are distinct from those controlling anal fin length. Thus, different courtship traits in Japanese medaka share a small number of QTL and have the potential for independent evolution. Copyright © 2015 Kawajiri et al.

Early Jurassic diversification of pycnodontiform fishes (Actinopterygii, Neopterygii) after the end-Triassic extinction event: evidence from a new genus and species, Grimmenodon aureum.

Science.gov (United States)

Stumpf, Sebastian; Ansorge, Jörg; Pfaff, Cathrin; Kriwet, Jürgen

2017-07-04

A new genus and species of pycnodontiform fishes, Grimmenodon aureum , from marginal marine, marine-brackish lower Toarcian ( Harpoceras exaratum ammonite subzone) clay deposits of Grimmen in northeastern Germany is described. The single specimen represents a diagnostic left prearticular dentition characterized by unique tooth arrangement and ornamentation patterns. Grimmenodon aureum , gen. et sp. nov., is the second unambiguously identified pycnodontiform species from the Early Jurassic, in addition to Eomesodon liassicus from the early Lower Jurassic of western Europe. We also report an indeterminate pycnodontiform tooth crown from the upper Pliensbachian ( Pleuroceras apyrenum ammonite subzone) of the same site. The material expands the Early Jurassic range of pycnodontiforms significantly northwards and confirms their presence before and immediately following the onset of the Toarcian Oceanic Anoxic Event (T-OAE) in the marginal marine ecosystems south of the Fennoscandian Shield. Moreover, the new records indicate that the Early Jurassic diversity of pycnodontiform fishes was greater than previously assumed and probably equaled that of the Late Triassic. Therefore, it is hypothesized that the Triassic-Jurassic mass extinction event did not affect pycnodontiform fishes significantly. Micro-computed tomography was used to study the internal anatomy of the prearticular of Grimmenodon aureum , gen. et sp. nov. Our results show that no replacement teeth were formed within the tooth-bearing bone but rather were added posteriorly to functional teeth. http://zoobank.org/urn:lsid:zoobank.org:pub:A56BDE9C-40C4-4CFA-9C2E-F5FA35A66F2 Citation for this article: Stumpf, S., J. Ansorge, C. Pfaff, and J. Kriwet. 2017. Early Jurassic diversification of pycnodontiform fishes (Actinopterygii, Neopterygii) after the end-Triassic extinction event: Evidence from a new genus and species, Grimmenodon aureum . Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2017.1344679.

Mathematical modelling of a Fin Ray type mechanism, used in the case of the wrist rehabilitation equipment

Directory of Open Access Journals (Sweden)

Filip Ovidiu

2017-01-01

Full Text Available The paper presents the mathematical modelling of some Fin Ray-type mechanism, destined for the wrist-rehabilitation equipment, its driving being made by a pneumatic muscle. The validity of the mathematical modelling of Fin Ray mechanism is verified by threedimensional mechanism made in Pro/Engineer.

Duplication of the dystroglycan gene in most branches of teleost fish

Directory of Open Access Journals (Sweden)

Giardina Bruno

2007-05-01

Full Text Available Abstract Background The dystroglycan (DG complex is a major non-integrin cell adhesion system whose multiple biological roles involve, among others, skeletal muscle stability, embryonic development and synapse maturation. DG is composed of two subunits: α-DG, extracellular and highly glycosylated, and the transmembrane β-DG, linking the cytoskeleton to the surrounding basement membrane in a wide variety of tissues. A single copy of the DG gene (DAG1 has been identified so far in humans and other mammals, encoding for a precursor protein which is post-translationally cleaved to liberate the two DG subunits. Similarly, D. rerio (zebrafish seems to have a single copy of DAG1, whose removal was shown to cause a severe dystrophic phenotype in adult animals, although it is known that during evolution, due to a whole genome duplication (WGD event, many teleost fish acquired multiple copies of several genes (paralogues. Results Data mining of pufferfish (T. nigroviridis and T. rubripes and other teleost fish (O. latipes and G. aculeatus available nucleotide sequences revealed the presence of two functional paralogous DG sequences. RT-PCR analysis proved that both the DG sequences are transcribed in T. nigroviridis. One of the two DG sequences harbours an additional mini-intronic sequence, 137 bp long, interrupting the uncomplicated exon-intron-exon pattern displayed by DAG1 in mammals and D. rerio. A similar scenario emerged also in D. labrax (sea bass, from whose genome we have cloned and sequenced a new DG sequence that also harbours a shorter additional intronic sequence of 116 bp. Western blot analysis confirmed the presence of DG protein products in all the species analysed including two teleost Antarctic species (T. bernacchii and C. hamatus. Conclusion Our evolutionary analysis has shown that the whole-genome duplication event in the Class Actinopterygii (ray-finned fish involved also DAG1. We unravelled new important molecular genetic details

Fish Individual-based Numerical Simulator (FINS): A particle-based model of juvenile salmonid movement and dissolved gas exposure history in the Columbia River Basin

International Nuclear Information System (INIS)

Scheibe, Timothy D.; Richmond, Marshall C.

2002-01-01

This paper describes a numerical model of juvenile salmonid migration in the Columbia and Snake Rivers. The model, called the Fish Individual-based Numerical Simulator or FINS, employs a discrete, particle-based approach to simulate the migration and history of exposure to dissolved gases of individual fish. FINS is linked to a two-dimensional (vertically-averaged) hydrodynamic simulator that quantifies local water velocity, temperature, and dissolved gas levels as a function of river flow rates and dam operations. Simulated gas exposure histories can be input to biological mortality models to predict the effects of various river configurations on fish injury and mortality due to dissolved gas supersaturation. Therefore, FINS serves as a critical linkage between hydrodynamic models of the river system and models of biological impacts. FINS was parameterized and validated based on observations of individual fish movements collected using radiotelemetry methods during 1997 and 1998 . A quasi-inverse approach was used to decouple fish swimming movements from advection with the local water velocity, allowing inference of time series of non-advective displacements of individual fish from the radiotelemetry data. Statistical analyses of these displacements are presented, and confirm that strong temporal correlation of fish swimming behavior persists in some cases over several hours. A correlated random-walk model was employed to simulate the observed migration behavior, and parameters of the model were estimated that lead to close correspondence between predictions and observations

Pectoral fin beat frequency predicts oxygen consumption during spontaneous activity in a labriform swimming fish (Embiotoca lateralis)

DEFF Research Database (Denmark)

Tudorache, Christian; Jordan, Anders D.; Svendsen, Jon Christian

2009-01-01

The objective of this study was to identify kinematic variables correlated with oxygen consumption during spontaneous labriform swimming. Kinematic variables (swimming speed, change of speed, turning angle, turning rate, turning radius and pectoral fin beat frequency) and oxygen consumption (MO2......) of spontaneous swimming in Embiotoca lateralis were measured in a circular arena using video tracking and respirometry, respectively. The main variable influencing MO2 was pectoral fin beat frequency (r (2) = 0.71). No significant relationship was found between swimming speed and pectoral fin beat frequency....... Complementary to other methods within biotelemetry such as EMG it is suggested that such correlations of pectoral fin beat frequency may be used to measure the energy requirements of labriform swimming fish such as E. lateralis in the field, but need to be taken with great caution since movement and oxygen...

Evolutionary trends of the pharyngeal dentition in Cypriniformes (Actinopterygii: Ostariophysi.

Directory of Open Access Journals (Sweden)

Emmanuel Pasco-Viel

Full Text Available BACKGROUND: The fish order Cypriniformes is one of the most diverse ray-finned fish groups in the world with more than 3000 recognized species. Cypriniformes are characterized by a striking distribution of their dentition: namely the absence of oral teeth and presence of pharyngeal teeth on the last gill arch (fifth ceratobranchial. Despite this limited localisation, the diversity of tooth patterns in Cypriniformes is astonishing. Here we provide a further description of this diversity using X-ray microtomography and we map the resulting dental characters on a phylogenetic tree to explore evolutionary trends. RESULTS: We performed a pilot survey of dental formulae and individual tooth shapes in 34 adult species of Cypriniformes by X-ray microtomography (using either conventional X-ray machine, or synchrotron microtomography when necessary or by dissecting. By mapping morphological results in a phylogenetic tree, it emerges that the two super-families Cobitoidea and Cyprinoidea have followed two distinct evolutionary pathways. Furthermore, our analysis supports the hypothesis of a three-row dentition as ancestral for Cyprinoidea and a general trend in tooth row reduction in most derived lineages. Yet, this general scheme must be considered with caution as several events of tooth row gain and loss have occurred during evolutionary history of Cyprinoidea. SIGNIFICANCE: Dentition diversity in Cypriniformes constitutes an excellent model to study the evolution of complex morphological structures. This morphological survey clearly advocates for extending the use of X-ray microtomography to study tooth morphology in Cypriniformes. Yet, our survey also underlines that improved knowledge of Cypriniformes life traits, such as feeding habits, is required as current knowledge is not sufficient to conclude on the link between diet and dental morphology.

The relationship between the mercury concentration in fish muscles and scales/fins and its significance

Czech Academy of Sciences Publication Activity Database

Červenka, R.; Bednařík, A.; Komárek, J.; Ondračková, Markéta; Jurajda, Pavel; Vítek, T.; Spurný, P.

2011-01-01

Roč. 9, č. 6 (2011), s. 1109-1116 ISSN 1895-1066 R&D Projects: GA MŠk LC522 Institutional research plan: CEZ:AV0Z60930519 Keywords : Mercury determination * Fish muscle * Scale * Fin Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 1.073, year: 2011

Undulating fins produce off-axis thrust and flow structures.

Science.gov (United States)

Neveln, Izaak D; Bale, Rahul; Bhalla, Amneet Pal Singh; Curet, Oscar M; Patankar, Neelesh A; MacIver, Malcolm A

2014-01-15

While wake structures of many forms of swimming and flying are well characterized, the wake generated by a freely swimming undulating fin has not yet been analyzed. These elongated fins allow fish to achieve enhanced agility exemplified by the forward, backward and vertical swimming capabilities of knifefish, and also have potential applications in the design of more maneuverable underwater vehicles. We present the flow structure of an undulating robotic fin model using particle image velocimetry to measure fluid velocity fields in the wake. We supplement the experimental robotic work with high-fidelity computational fluid dynamics, simulating the hydrodynamics of both a virtual fish, whose fin kinematics and fin plus body morphology are measured from a freely swimming knifefish, and a virtual rendering of our robot. Our results indicate that a series of linked vortex tubes is shed off the long edge of the fin as the undulatory wave travels lengthwise along the fin. A jet at an oblique angle to the fin is associated with the successive vortex tubes, propelling the fish forward. The vortex structure bears similarity to the linked vortex ring structure trailing the oscillating caudal fin of a carangiform swimmer, though the vortex rings are distorted because of the undulatory kinematics of the elongated fin.

The role of the nervous system in fish evolution

Directory of Open Access Journals (Sweden)

Michael H Hofmann

2015-12-01

Full Text Available The nervous system plays an important role in the evolution and adaptation of animals. All sensory and motor functions as well as cognitive abilities are organized in the brain and spinal cord. Volumetric measurements of different brain regions were made in more than 150 species of ray finned fishes as well as in several outgroups. In Actanthopterygii, the hypothalamus shows greatest enlargement most likely due to an enormous visual input via the nucleus glomerulosos. The telencephalon is highly differentiated in many acanthopterygii, mostly coral reef species, but its relative size is not much effected. There is, however, a clear shift from olfactory to visual functions in ray finned fishes. In species with a highly differentiated telencephalon, the area where place memory may be located is very prominent. In basal ray finned fishes, lungfish, amphibia and elasmobranchs, the olfactory bulb is relatively large and the ratio of the olfactory bulb and telencephalon large as well. This holds also for elopomorpha and spiny eels, but in most other groups vision dominates. Apart from differences between larger clades, variation in brain architecture are also seen in closely related species and even between sexes of the same species. Profound differences are present in the cerebellum between male and female swordtails and in the telencephalon of sticklebacks. Morphometric analysis of brain architecture turned out to be an important tool to study the evolution and adaptations of the brain in fishes.

The extraordinary biology and development of marsupial frogs (Hemiphractidae) in comparison with fish, mammals, birds, amphibians and other animals.

Science.gov (United States)

Del Pino, Eugenia M

2018-01-03

The study of oogenesis and early development of frogs belonging to the family Hemiphractidae provide important comparison to the aquatic development of other frogs, such as Xenopus laevis, because reproduction on land characterizes the Hemiphractidae. In this review, the multinucleated oogenesis of the marsupial frog Flectonotus pygmaeus (Hemiphractidae) is analyzed and interpreted. In addition, the adaptations associated with the incubation of embryos in the pouch of the female marsupial frog Gastrotheca riobambae (Hemiphractidae) and the embryonic development of this frog are summarized. Moreover, G. riobambae gastrulation is compared with the gastrulation modes of Engystomops randi and Engystomops coloradorum (Leptodactylidae); Ceratophrys stolzmanni (Ceratophryidae); Hyalinobatrachium fleischmanni and Espadarana callistomma (Centrolenidae); Ameerega bilinguis, Dendrobates auratus, Epipedobates anthonyi, Epipedobates machalilla, Epipedobates tricolor, and Hyloxalus vertebralis (Dendrobatidae); Eleutherodactylus coqui (Terrarana: Eleutherodactylidae), and X. laevis (Pipidae). The comparison indicated two modes of frog gastrulation. In X. laevis and in frogs with aquatic reproduction, convergent extension begins during gastrulation. In contrast, convergent extension occurs in the post-gastrula of frogs with terrestrial reproduction. These two modes of gastrulation resemble the transitions toward meroblastic cleavage found in ray-finned fishes (Actinopterygii). In spite of this difference, the genes that guide early development seem to be highly conserved in frogs. I conclude that the shift of convergent extension to the post-gastrula accompanied the diversification of frog egg size and terrestrial reproductive modes. Copyright © 2018 Elsevier B.V. All rights reserved.

Plectranthias lamillai, a new Anthiine fish species (Perciformes, Serranidae from the Juan Fernández Archipelago, Chile

Directory of Open Access Journals (Sweden)

José Rodrigo Rojas M.

1998-09-01

Full Text Available Plectranthias lamillai new species, is described and illustrated as a new anthiine serranid fish from Alejandro Selkirk Island, the westernmost island of the Juan Fernández Archipelago, about 700 km west of Chile at 33°45´S, 80°51´W. The following combination of characters distinguishes it from all other serranids: dorsal fin rays X,16; principal caudal-fin rays 17 (8+9; pectoral-fin rays 16; gillrakers 28 (8+20; tubed lateral-line scales 40-41; 10 rows of scales on cheek; maxilla narrow and rounded; posterior margin of bony opercle with three spinous processes, the middle one largest; subopercle 2-6 small serrae; pseudobranch with 24 filaments; circumpeduncular scales 16; pelvic fin inserted beneath base of pectoral fin, the tip reaching a vertical through base of tenth dorsal-fin spine, falling short of the anus; a broad red bar from sixth dorsal-fin spine to base of fifth ray, extending to anus and above anal fin as a narrow band that widens on the peduncle and then bifurcates over the upper and lower margins of the caudal fin; rest of the caudal fin yellowish. Pectoral fins orange; pelvic and anal fins whitish.

A biorobotic pectoral fin for autonomous undersea vehicles.

Science.gov (United States)

Tangorra, James L; Davidson, S Naomi; Madden, Peter G; Lauder, George V; Hunter, Ian W

2006-01-01

A biorobotic fin for autonomous undersea vehicles (AUVs) was developed based on studies of the anatomy, kinematics, and hydrodynamics of the bluegill sunfish pectoral fin. The biorobotic fin was able to produce many of the complex fin motions used by the sunfish during steady swimming and was used to investigate mechanisms of thrust production and control. This biorobotic fin is an excellent experimental tool and is an important first step towards developing propulsive devices that give AUVs maneuvering characteristics that match and exceed those of highly maneuverable fish.

New gadiform fishes (Teleostei, Gadiformes) from the Miocene of Algeria

Science.gov (United States)

Carnevale, Giorgio

2007-02-01

As part of the completion of studies on the Miocene fishes of the Chelif Basin (north-western Algeria), this paper represents a contribution to the knowledge of the Messinian gadiform diversity of this western Mediterranean, semi-enclosed, Neogene basin. A new genus and species of the family Macrouridae is erected ( Razelainia paradoxa n. gen. et sp.), two specimens are tentatively referred to already existing taxa ( Gadiculus cf. jonas; Merluccius cf. merluccius), and a species formerly assigned to the gadid genus Brosme is transferred to the genus Gaidropsarus ( Gaidropsarus murdjadjensis). The macrourid Razelainia paradoxa n. gen. et sp. is characterized by an unusual combination of: plesiomorphic gadiform features, such as low vertebral number (presumed), well-developed caudal-fin rays, presence of a single continuous dorsal fin originating just posterior to the neurocranium, anal-fin rays slightly longer than dorsal-fin rays; and derived, typically macrourid features, such as the presence of spinoid scales and the anterior anal-fin pterygiophores extending forward over the abdominal wall. A paleoecological analysis reveals that the Messinian gadiform assemblage of the Chelif Basin had a subtropical/warm temperate affinity, with a marked north-eastern Atlantic-Mediterranean biogeographic character.

Fish biorobotics: kinematics and hydrodynamics of self-propulsion.

Science.gov (United States)

Lauder, George V; Anderson, Erik J; Tangorra, James; Madden, Peter G A

2007-08-01

As a result of years of research on the comparative biomechanics and physiology of moving through water, biologists and engineers have made considerable progress in understanding how animals moving underwater use their muscles to power movement, in describing body and appendage motion during propulsion, and in conducting experimental and computational analyses of fluid movement and attendant forces. But it is clear that substantial future progress in understanding aquatic propulsion will require new lines of attack. Recent years have seen the advent of one such new avenue that promises to greatly broaden the scope of intellectual opportunity available to researchers: the use of biorobotic models. In this paper we discuss, using aquatic propulsion in fishes as our focal example, how using robotic models can lead to new insights in the study of aquatic propulsion. We use two examples: (1) pectoral fin function, and (2) hydrodynamic interactions between dorsal and caudal fins. Pectoral fin function is characterized by considerable deformation of individual fin rays, as well as spanwise (along the length) and chordwise (across the fin) deformation and area change. The pectoral fin can generate thrust on both the outstroke and instroke. A robotic model of the pectoral fin replicates this result, and demonstrates the effect of altering stroke kinematics on the pattern of force production. The soft dorsal fin of fishes sheds a distinct vortex wake that dramatically alters incoming flow to the tail: the dorsal fin and caudal fin act as dual flapping foils in series. This design can be replicated with a dual-foil flapping robotic device that demonstrates this phenomenon and allows examination of regions of the flapping performance space not available to fishes. We show how the robotic flapping foil device can also be used to better understand the significance of flexible propulsive surfaces for locomotor performance. Finally we emphasize the utility of self

Differential regulation of msx genes in the development of the gonopodium, an intromittent organ, and of the "sword," a sexually selected trait of swordtail fishes (Xiphophorus).

Science.gov (United States)

Zauner, Hans; Begemann, Gerrit; Marí-Beffa, Manuel; Meyer, Axel

2003-01-01

The possession of a conspicuous extension of colored ventral rays of the caudal fin in male fish of swordtails (genus Xiphophorus) is a prominent example for a trait that evolved by sexual selection. To understand the evolutionary history of this so-called sword molecularly, it is of interest to unravel the developmental pathways responsible for extended growth of sword rays during development of swordtail males. We isolated two msx genes and showed that they are differentially regulated during sword outgrowth. During sword growth in juvenile males, as well as during testosterone-induced sword development and fin ray regeneration in the sword after amputation, expression of msxC is markedly up-regulated in the sword forming fin rays. In contrast, msxE/1 is not differentially expressed in ventral and dorsal male fin rays, suggesting a link between the development of male secondary sexual characters in fins and up-regulation of msxC expression. In addition, we showed that msx gene expression patterns differ significantly between Xiphophorus and zebrafish. We also included in our study the gonopodium, a testosterone-dependent anal fin modification that serves as a fertilization organ in males of live-bearing fishes. Our finding that increased levels of msxC expression are associated with the testosterone-induced outgrowth of the gonopodium might suggest either that at least parts of the signaling pathways that pattern the evolutionary older gonopodium have been coopted to evolve a sexually selected innovation such as the sword or that increased msxC expression may be inherent to the growth process of long fin rays in general.

Embedded SMA wire actuated biomimetic fin: a module for biomimetic underwater propulsion

International Nuclear Information System (INIS)

Wang Zhenlong; Hang Guanrong; Wang Yangwei; Li Jian; Du Wei

2008-01-01

An embedded shape memory alloy (SMA) wire actuated biomimetic fin is presented, and based on this module for biomimetic underwater propulsion, a micro robot fish (146 mm in length, 30 g in weight) and a robot squid (242 mm in length, 360 g in weight) were developed. Fish swim by undulating their body and/or fins. Squid and cuttlefish can also swim by undulating their fins. To simplify engineering modeling, the undulating swimming movement is assumed to be the integration of the movements of many flexible bending segments connected in parallel or in series. According to this idea, a biomimetic fin which can bend flexibly was developed. The musculature of a cuttlefish fin was investigated to aid the design of the biomimetic fin. SMA wires act as 'muscle fibers' to drive the biomimetic fin just like the transverse muscles of the cuttlefish fin. During the bending phase, elastic energy is stored in the elastic substrate and skin, and during the return phase, elastic energy is released to power the return movement. Theorem analysis of the bending angle was performed to estimate the bending performance of the biomimetic fin. Experiments were carried out on single-face fins with latex rubber skin and silicone skin (SF-L and SF-S) to compare the bending angle, return time, elastic energy storage and reliability. Silicone was found to be the better skin. A dual-face fin with silicone skin (DF-S) was tested in water to evaluate the actuating performance and to validate the reliability. Thermal analysis of the SMA temperature was performed to aid the control strategy. The micro robot fish and robot squid employ one and ten DF-S, respectively. Swimming experiments with different actuation frequencies were carried out. The speed and steering radius of the micro robot fish reached 112 mm s −1 and 136 mm, respectively, and the speed and rotary speed of the robot squid reached 40 mm s −1 and 22° s −1 , respectively

Fish Allergy

Science.gov (United States)

... Cause Blog Vision Awards Common Allergens Fish Allergy Fish Allergy Learn about fish allergy, how to read ... that you must avoid both. Allergic Reactions to Fish Finned fish can cause severe and potentially life- ...

Effect of morphological fin curl on the swimming performance and station-holding ability of juvenile shovelnose sturgeon

Science.gov (United States)

Deslauriers, David; Johnston, Ryan; Chipps, Steven R.

2016-01-01

We assessed the effect of fin-curl on the swimming and station-holding ability of juvenile shovelnose sturgeon Scaphirhynchus platorynchus (mean fork length = 17 cm; mean weight = 16 g; n = 21) using a critical swimming speed test performed in a small swim chamber (90 L) at 20°C. We quantified fin-curl severity using the pectoral fin index. Results showed a positive relationship between pectoral fin index and critical swimming speed indicative of reduced swimming performance displayed by fish afflicted with a pectoral fin index < 8%. Fin-curl severity, however, did not affect the station-holding ability of individual fish. Rather, fish affected with severe fin-curl were likely unable to use their pectoral fins to position their body adequately in the water column, which led to the early onset of fatigue. Results generated from this study should serve as an important consideration for future stocking practices.

Fish Pectoral Fin Hydrodynamics; Part III: Low Dimensional Models via POD Analysis

Science.gov (United States)

Bozkurttas, M.; Madden, P.

2005-11-01

The highly complex kinematics of the pectoral fin and the resulting hydrodynamics does not lend itself easily to analysis based on simple notions of pitching/heaving/paddling kinematics or lift/drag based propulsive mechanisms. A more inventive approach is needed to dissect the fin gait and gain insight into the hydrodynamic performance of the pectoral fin. The focus of the current work is on the hydrodynamics of the pectoral fin of a bluegill sunfish in steady forward motion. The 3D, time-dependent fin kinematics is obtained via a stereo-videographic technique. We employ proper orthogonal decomposition to extract the essential features of the fin gait and then use CFD to examine the hydrodynamics of simplified gaits synthesized from the POD modes. The POD spectrum shows that the first two, three and five POD modes capture 55%, 67%, and 80% of the motion respectively. The first three modes are in particular highly distinct: Mode-1 is a ``cupping'' motion where the fin cups forward as it is abducted; Mode-2 is an ``expansion'' motion where the fin expands to present a larger area during adduction and finally Mode-3 involves a ``spanwise flick'' of the dorsal edge of the fin. Numerical simulation of flow past fin gaits synthesized from these modes lead to insights into the mechanisms of thrust production; these are discussed in detail.

A non-digging zoobenthivorous fish attracts two opportunistic predatory fish associates

Directory of Open Access Journals (Sweden)

Cristina Sazima

Full Text Available Following behaviour among reef fishes involves mostly a digging nuclear species while foraging, which attracts opportunistic followers preying on the exposed organisms. The flying gurnard Dactylopterus volitans preys on benthic animals, mostly crustaceans and small fishes, scratching and probing the bottom with the inner rays of its pectoral fins. We recorded the flying gurnard being followed by two opportunistic predators, the yellow jack Caranx bartholomaei and the coney Cephalopholis fulva at Fernando de Noronha, off northeast Brazil. Albeit not actually digging the substrate, the flying gurnard acts as a nuclear species by exploring algae tufts and by its wandering near the boulders and ledges, disturbing and flushing out hidden animals which thus become available to predation.

Does fin coloration signal social status in a dominance hierarchy of the livebearing fish Xiphophorus variatus?

Science.gov (United States)

Culumber, Zachary W; Monks, Scott

2014-09-01

In each population of the livebearing fish Xiphophorus variatus, only a small portion of the adult males develop bright yellow-red (YR) coloration on the dorsal and caudal fins. Here we characterized the dominance hierarchy in X. variatus and tested whether YR coloration is related to a male's position in the hierarchy and can therefore serve as a reliable cue to rival males. Populations varied considerably in the frequency of YR males. Across all populations, males with YR coloration were significantly larger than the rest of the males in the population. Observations of aggressive interactions among males in small groups in the laboratory revealed a sized-based dominance hierarchy with YR males at the top. Aggression was more common among males of a similar size and fighting increased as male body size differences decreased. However, despite the reliability of YR coloration as a signal of dominance status, males at lower social ranks did not avoid aggression with YR males and YR males did not experience fewer aggressive attacks compared to non-YR males. Our findings demonstrate that fin coloration is a reliable cue of a male's social status but rival males appear to not use this information to avoid potentially costly interactions with dominant males, suggesting that YR fin coloration has not evolved as a cue in agonistic interactions. Copyright © 2014 Elsevier B.V. All rights reserved.

Preliminary list of endangered fish species (Pisces, Elasmobranchii , Actinopterygii) in Brazil

OpenAIRE

Rosa, Ricardo S; Menezes, Naércio A

1996-01-01

The Brazilian fish fauna is still poorly known with respect to its diversity and conservation status, particularly of freshwater species. Human activities and population growth are rapidly impacting this fauna to an unchecked extent, so that many fish species are presently threatened. Also, some areas have been so critically altered that their fish fauna can no longer be properly inventoried. There is an urgent need to evaluate the conservation status of Brazilian fish species, since none are...

The sexually dimorphic adipose fin is an androgen target tissue in the brown trout (Salmo trutta fario).

Science.gov (United States)

Hisar, Olcay; Sönmez, Adem Yavuz; Hisar, Şükriye Aras; Budak, Harun; Gültepe, Nejdet

2013-04-01

An investigation has been described on the relationship of body length, age and sex with adipose fin length and the number of androgen receptor (AR)-containing cells in the adipose fin as a secondary sexual characteristic for brown trout (Salmo trutta fario). Firstly, body and adipose fin lengths of 2- to 5-year-old brown trout were measured. Thereafter, these fish were killed by decapitation, then their sexes were determined, and adipose fins were excised. The cellular bases of AR binding activities in the adipose fins were analyzed with an antibody against human/rat AR peptide. Immunocytochemistry and western blotting techniques were performed with this antibody. Analysis of morphological measurements indicated that body length and age had a linear relationship with adipose fin length. The coefficients of determination for the body length and age were 0.92 and 0.85 in the male fish and 0.76 and 0.73 in the female fish against the adipose fin length, respectively. At 2 years of age, cells in the adipose fin did not exhibit AR immunoreactivity. However, AR-immunopositive cells were abundant in the adipose fin of 3- to 5-year-old fish. Moreover, the number of AR-immunopositive cells was significantly (P brown trout is a probable target for androgen action and that tissue function or development may to some extent be androgen dependent. In addition, it is likely that such an effect will be mediated by specific androgen receptors.

The Design and Implementation of a Biomimetic Robot Fish

OpenAIRE

Chao Zhou; Min Tan; Nong Gu; Zhiqiang Cao; Shuo Wang; Long Wang

2008-01-01

In this paper, a novel design of a biomimetic robot fish is presented. Based on the propulsion and maneuvering mechanisms of real fishes, a tail mechanical structure with cams and connecting rods for fitting carangiform fish body wave is designed, which provides the main propulsion. Two pectoral fins are mounted, and each pectoral fin can flap separately and rotate freely. Coordinating the movements of the tail and pectoral fins, the robot fish can simulate the movements of fishes in water. I...

Relying on fin erosion to identify hatchery-reared brown trout in a Tennessee river

Science.gov (United States)

Meerbeek, Jonathan R.; Bettoli, Phillip William

2012-01-01

Hatchery-induced fin erosion can be used to identify recently stocked catchable-size brown trout Salmo trutta during annual surveys to qualitatively estimate contributions to a fishery. However, little is known about the longevity of this mark and its effectiveness as a short-term (≤ 1 year) mass-marking technique. We evaluated hatchery-induced pectoral fin erosion as a mass-marking technique for short-term stocking evaluations by stocking microtagged brown trout in a tailwater and repeatedly sampling those fish to observe and measure their pectoral fins. At Dale Hollow National Fish Hatchery, 99.1% (228 of 230) of microtagged brown trout in outdoor concrete raceways had eroded pectoral fins 1 d prior to stocking. Between 34 and 68 microtagged and 26-35 wild brown trout were collected during eight subsequent electrofishing samples. In a blind test based on visual examination of pectoral fins at up to 322 d poststocking, one observer correctly identified 91.7% to 100.0% (mean of 96.9%) of microtagged brown trout prior to checking for microtags. In the laboratory, pectoral fin length and width measurements were recorded to statistically compare the fin measurements of wild and microtagged hatchery brown trout. With only one exception, all pectoral fin measurements on each date averaged significantly larger for wild trout than for microtagged brown trout. Based on the number of pectoral fin measurements falling below 95% prediction intervals, 93.7% (148 of 158) of microtagged trout were correctly identified as hatchery fish based on regression models up to 160 d poststocking. Only 72.2% (70 of 97) of microtagged trout were identified correctly after 160 d based on pectoral fin measurements and the regression models. We concluded that visual examination of pectoral fin erosion was a very effective way to identify stocked brown trout for up to 322 d poststocking.

Investigation of gliding flight by flying fish

Science.gov (United States)

Park, Hyungmin; Jeon, Woo-Pyung; Choi, Haecheon

2006-11-01

The most successful flight capability of fish is observed in the flying fish. Furthermore, despite the difference between two medium (air and water), the flying fish is well evolved to have an excellent gliding performance as well as fast swimming capability. In this study, flying fish's morphological adaptation to gliding flight is experimentally investigated using dry-mounted darkedged-wing flying fish, Cypselurus Hiraii. Specifically, we examine the effects of the pectoral and pelvic fins on the aerodynamic performance considering (i) both pectoral and pelvic fins, (ii) pectoral fins only, and (iii) body only with both fins folded. Varying the attack angle, we measure the lift, drag and pitching moment at the free-stream velocity of 12m/s for each case. Case (i) has higher lift-to-drag ratio (i.e. longer gliding distance) and more enhanced longitudinal static stability than case (ii). However, the lift coefficient is smaller for case (i) than for case (ii), indicating that the pelvic fins are not so beneficial for wing loading. The gliding performance of flying fish is compared with those of other fliers and is found to be similar to those of insects such as the butterfly and fruitfly.

Origin of fin-clipped salmonids collected at two thermal discharges on Lake Michigan

International Nuclear Information System (INIS)

Romberg, G.P.; Thommes, M.M.; Spigarelli, S.A.

1974-01-01

Fin clips observed on fish collected during tagging studies at the Point Beach and Waukegan thermal discharges were recorded and the data were tabulated by species. Using fin clip and fish size, attempts were made to identify probable stocking locations and dates from agency records. Data are presented for lake trout, rainbow trout, brown trout, and Coho salmon. Tables are presented to show probable stocking locations and dates

Live fate-mapping of joint-associated fibroblasts visualizes expansion of cell contributions during zebrafish fin regeneration.

Science.gov (United States)

Tornini, Valerie A; Thompson, John D; Allen, Raymond L; Poss, Kenneth D

2017-08-15

The blastema is a mass of progenitor cells responsible for regeneration of amputated salamander limbs and fish fins. Previous studies have indicated that resident cell sources producing the blastema contribute lineage-restricted progeny to regenerating tissue. However, these studies have labeled general cell types rather than granular cell subpopulations, and they do not explain the developmental transitions that must occur for distal structures to arise from cells with proximal identities in the appendage stump. Here, we find that regulatory sequences of tph1b , which encodes an enzyme that synthesizes serotonin, mark a subpopulation of fibroblast-like cells restricted to the joints of uninjured adult zebrafish fins. Amputation stimulates serotonin production in regenerating fin fibroblasts, yet targeted tph1b mutations abrogating this response do not disrupt fin regeneration. In uninjured animals, tph1b -expressing cells contribute fibroblast progeny that remain restricted to joints throughout life. By contrast, upon amputation, tph1b + joint cells give rise to fibroblasts that distribute across the entire lengths of regenerating fin rays. Our experiments visualize and quantify how incorporation into an appendage blastema broadens the progeny contributions of a cellular subpopulation that normally has proximodistal restrictions. © 2017. Published by The Company of Biologists Ltd.

BIOMETRY AND COMPOSITION OF FISH SPECIES IN OWENA RESERVOIR, ONDO STATE, NIGERIA

Directory of Open Access Journals (Sweden)

FAPOHUNDA Olawumi Oluwafunmilola

2007-11-01

Full Text Available A survey of fish species present in Owena reservoir was conducted between October 2004 and March 2005. Fish samples were taken from the catch of the fishermen operating in the reservoir. The results of the survey showed that 14 fish species belonging to seven families were recorded. Two families namely Characidae and Clariidae constituted the dominant fish families in the reservoir. Among the Characidae, Brycinus nurse (23.1% and among the Clariidae family, Clarias gariepinus (22.8% were dominant. Other fish species with significant abundance were Sarotherodon galilaeus (9.3%, Parachanna obscura (8.0%, Clarias anguillaris (7.7% and Oreochromis niloticus (6.4%. The meristic features of the two most abundant fish species caught are as follows: Brycinus nurse had two dorsal spines with eight dorsal fins, two anal spines with eleven anal fins, 25 caudal fins, one pectoral spine and 13 pectoral fins and two ventral spines with seven ventral fins. Clarias gariepinus had 75 dorsal fins, 31 anal fins, 10 caudal fins, six pectoral fins and five ventral fins. The morphometric features of the two most abundant fish species are: Brycinus nurse: total length: 312mm, standard length: 255mm, head length: 60mm, body length: 90mm and body girth: 190mm. Clarias gariepinus: total length: 265mm, standard length: 240mm, head length: 62mm, body length: 62mm and body girth: 130mm.

Aerodynamic characteristics of flying fish in gliding flight.

Science.gov (United States)

Park, Hyungmin; Choi, Haecheon

2010-10-01

The flying fish (family Exocoetidae) is an exceptional marine flying vertebrate, utilizing the advantages of moving in two different media, i.e. swimming in water and flying in air. Despite some physical limitations by moving in both water and air, the flying fish has evolved to have good aerodynamic designs (such as the hypertrophied fins and cylindrical body with a ventrally flattened surface) for proficient gliding flight. Hence, the morphological and behavioral adaptations of flying fish to aerial locomotion have attracted great interest from various fields including biology and aerodynamics. Several aspects of the flight of flying fish have been determined or conjectured from previous field observations and measurements of morphometric parameters. However, the detailed measurement of wing performance associated with its morphometry for identifying the characteristics of flight in flying fish has not been performed yet. Therefore, in the present study, we directly measure the aerodynamic forces and moment on darkedged-wing flying fish (Cypselurus hiraii) models and correlated them with morphological characteristics of wing (fin). The model configurations considered are: (1) both the pectoral and pelvic fins spread out, (2) only the pectoral fins spread with the pelvic fins folded, and (3) both fins folded. The role of the pelvic fins was found to increase the lift force and lift-to-drag ratio, which is confirmed by the jet-like flow structure existing between the pectoral and pelvic fins. With both the pectoral and pelvic fins spread, the longitudinal static stability is also more enhanced than that with the pelvic fins folded. For cases 1 and 2, the lift-to-drag ratio was maximum at attack angles of around 0 deg, where the attack angle is the angle between the longitudinal body axis and the flying direction. The lift coefficient is largest at attack angles around 30∼35 deg, at which the flying fish is observed to emerge from the sea surface. From glide polar

Experimental parametric study of a biomimetic fish robot actuated by piezoelectric actuators

Science.gov (United States)

Wiguna, T.; Park, Hoon C.; Heo, S.; Goo, Nam S.

2007-04-01

This paper presents an experiment and parametric study of a biomimetic fish robot actuated by the Lightweight Piezocomposite Actuator (LIPCA). The biomimetic aspects in this work are the oscillating tail beat motion and shape of caudal fin. Caudal fins that resemble fins of BCF (Body and Caudal Fin) mode fish were made in order to perform parametric study concerning the effect of caudal fin characteristics on thrust production at an operating frequency range. The observed caudal fin characteristics are the shape, stiffness, area, and aspect ratio. It is found that a high aspect ratio caudal fin contributes to high swimming speed. The robotic fish propelled by artificial caudal fins shaped after thunniform-fish and mackerel caudal fins, which have relatively high aspect ratio, produced swimming speed as high as 2.364 cm/s and 2.519 cm/s, respectively, for a 300 V p-p input voltage excited at 0.9 Hz. Thrust performance of the biomimetic fish robot is examined by calculating Strouhal number, Froude number, Reynolds number, and power consumption.

Genomic Sequence of a Ranavirus Isolated from Short-Finned Eel (Anguilla australis)

DEFF Research Database (Denmark)

Subramaniam, Kuttichantran; Toffan, Anna; Cappellozza, Elisabetta

2016-01-01

The short-finned eel ranavirus (SERV) was isolated from short-finned eel imported to Italy from New Zealand. Phylogenomic analyses revealed that SERV is a unique member of the genus Ranavirus, family Iridoviridae, branching at the base of the tree near other fish ranaviruses....

A review on robotic fish enabled by ionic polymer-metal composite artificial muscles.

Science.gov (United States)

Chen, Zheng

2017-01-01

A novel actuating material, which is lightweight, soft, and capable of generating large flapping motion under electrical stimuli, is highly desirable to build energy-efficient and maneuverable bio-inspired underwater robots. Ionic polymer-metal composites are important category of electroactive polymers, since they can generate large bending motions under low actuation voltages. IPMCs are ideal artificial muscles for small-scale and bio-inspired robots. This paper takes a system perspective to review the recent work on IPMC-enabled underwater robots, from modeling, fabrication, and bio-inspired design perspectives. First, a physics-based and control-oriented model of IPMC actuator will be reviewed. Second, a bio-inspired robotic fish propelled by IPMC caudal fin will be presented and a steady-state speed model of the fish will be demonstrated. Third, a novel fabrication process for 3D actuating membrane will be introduced and a bio-inspired robotic manta ray propelled by two IPMC pectoral fins will be demonstrated. Fourth, a 2D maneuverable robotic fish propelled by multiple IPMC fin will be presented. Last, advantages and challenges of using IPMC artificial muscles in bio-inspired robots will be concluded.

Fatty fish intake and cognitive function: FINS-KIDS, a randomized controlled trial in preschool children.

Science.gov (United States)

Øyen, Jannike; Kvestad, Ingrid; Midtbø, Lisa Kolden; Graff, Ingvild Eide; Hysing, Mari; Stormark, Kjell Morten; Markhus, Maria Wik; Baste, Valborg; Frøyland, Livar; Koletzko, Berthold; Demmelmair, Hans; Dahl, Lisbeth; Lie, Øyvind; Kjellevold, Marian

2018-03-12

Marine resources including fatty fish are important sources of n-3 long chain polyunsaturated fatty acids (n-3 LC-PUFAs), which are important for brain development. To our knowledge, this is the first randomized controlled trial (RCT) investigating the impact of fatty fish on cognition in preschool children. The purpose of the trial was to investigate whether an increased intake of fatty fish compared to meat improves cognitive function in children 4-6 years old. The children (n = 232) in this two-armed RCT, Fish Intervention Studies-KIDS (FINS-KIDS) were recruited from 13 kindergartens in Bergen, Norway. They were randomly assigned to lunch meals with fatty fish (herring/mackerel) or meat (chicken/lamb/beef) three times a week for 16 weeks. The fish and meat were weighed before and after the meals to record the exact consumption (dietary compliance). The primary outcome was cognitive function measured by the Wechsler Preschool and Primary Scale of Intelligence, 3rd edition (WPPSI-III) and fine-motor coordination measured by the 9-Hole Peg Test (9-HPT) at pre- and post-intervention. Biological samples (blood, urine, hair), and questionnaires to the caregivers were included at both time points. Linear mixed effect models with a random intercept for kindergarten were used to analyze changes from pre- to post-intervention in the primary outcome variables. There were 218 children included in the trial (105 in the fish, and 113 in the meat group). The children consumed a mean (standard deviation) of 2070 (978) g fish or 2675 (850) g meat from the study meals (p < 0.0001). The fish group had a significant increase of red blood cell n-3 LC-PUFAs. The intervention had no effect on the WPPSI-III scores (mean change total raw score; fish group 17.7, 95% confidence interval (CI) 14.8-20.7 vs meat group 17.8, 95% CI 15.0-20.6, p = 0.97) in the main analyses. In the sub-analyses, adjusting for dietary compliance, the fish group showed a higher improvement on total raw score (20

The Design and Implementation of a Biomimetic Robot Fish

Directory of Open Access Journals (Sweden)

Chao Zhou

2008-11-01

Full Text Available In this paper, a novel design of a biomimetic robot fish is presented. Based on the propulsion and maneuvering mechanisms of real fishes, a tail mechanical structure with cams and connecting rods for fitting carangiform fish body wave is designed, which provides the main propulsion. Two pectoral fins are mounted, and each pectoral fin can flap separately and rotate freely. Coordinating the movements of the tail and pectoral fins, the robot fish can simulate the movements of fishes in water. In order to obtain the necessary environmental information, several kinds of sensors (video, infrared, temperature, pressure and PH value sensors were mounted. Finally, the realization of the robot fish is presented.

The Design and Implementation of a Biomimetic Robot Fish

Directory of Open Access Journals (Sweden)

Chao Zhou

2008-06-01

Full Text Available In this paper, a novel design of a biomimetic robot fish is presented. Based on the propulsion and maneuvering mechanisms of real fishes, a tail mechanical structure with cams and connecting rods for fitting carangiform fish body wave is designed, which provides the main propulsion. Two pectoral fins are mounted, and each pectoral fin can flap separately and rotate freely. Coordinating the movements of the tail and pectoral fins, the robot fish can simulate the movements of fishes in water. In order to obtain the necessary environmental information, several kinds of sensors (video, infrared, temperature, pressure and PH value sensors were mounted. Finally, the realization of the robot fish is presented.

Fossil-based comparative analyses reveal ancient marine ancestry erased by extinction in ray-finned fishes.

Science.gov (United States)

Betancur-R, Ricardo; Ortí, Guillermo; Pyron, Robert Alexander

2015-05-01

The marine-freshwater boundary is a major biodiversity gradient and few groups have colonised both systems successfully. Fishes have transitioned between habitats repeatedly, diversifying in rivers, lakes and oceans over evolutionary time. However, their history of habitat colonisation and diversification is unclear based on available fossil and phylogenetic data. We estimate ancestral habitats and diversification and transition rates using a large-scale phylogeny of extant fish taxa and one containing a massive number of extinct species. Extant-only phylogenetic analyses indicate freshwater ancestry, but inclusion of fossils reveal strong evidence of marine ancestry in lineages now restricted to freshwaters. Diversification and colonisation dynamics vary asymmetrically between habitats, as marine lineages colonise and flourish in rivers more frequently than the reverse. Our study highlights the importance of including fossils in comparative analyses, showing that freshwaters have played a role as refuges for ancient fish lineages, a signal erased by extinction in extant-only phylogenies. © 2015 John Wiley & Sons Ltd/CNRS.

Combining morphology and genetics in resolving taxonomy--a systematic revision of spined loaches (Genus Cobitis; Cypriniformes, Actinopterygii in the Adriatic watershed.

Directory of Open Access Journals (Sweden)

Ivana Buj

Full Text Available Taxonomic investigation of spined loaches from Dalmatia and Herzegovina was conducted on specimens from 14 localities. The results of the detailed morphological investigations were combined with genetic data (based on one mitochondrial and two nuclear genes in order to resolve the taxonomic status of each Cobitis population. Among the investigated features of external morphology, the appearance of spots on the caudal fin base turned out to have the greatest diagnostic value. Furthermore, the number of branched fin rays enabled the discrimination of several species. No morphometric character alone could ensure determination of any Cobitis species. Nevertheless, groups of populations that are more similar in their body shapes correspond to mitochondrial phylogenetic lineages. Based on molecular genetic markers, Dalmatian and Herzegovinian spined loaches form independent lineages inside the Adriatic phylogenetic group. Mitochondrial DNA phylogenetic reconstruction revealed six monophyletic lineages, corresponding to six species distributed in the investigated area. The population distributed in Mostarsko blato karstic field in Bosnia and Herzegovina is described as a new species based on a unique combination of morphological characters: a single triangular Canestrini scale; usually 51/2 branched anal fin rays, 61/2 branched dorsal fin rays, 14 branched caudal fin rays; no spots in the surface pigmentation layer on the caudal fin base; scales on the body very small.

Growth pattern and natural mortality of elephant fishes (Mormyrus kannume, Mormyridae in the Damietta branch of Nile, Egypt

Directory of Open Access Journals (Sweden)

Evelyn Ragheb

2016-06-01

Full Text Available The present study sheds light on the growth pattern of the elephant snout fish (Mormyrus kannume, Mormyridae in the Damietta branch of the Nile during the period from January to December 2010. This is done through studying the biometric characters, length–weight relationship, condition factors, growth performance index as well as the natural mortality. The linear regression for 15 morphometric characters in total length and 4 morphometric characters in head length was applied. The higher coefficient of the characters’ determinations which fit best was also applied. Five meristic characters were determined (dorsal fin rays, 49–69; pectoral fin rays, 12–15; ventral fin rays, 6; anal fin rays, 17–21 and vertebrae, 49–52. Fish length varied between 14.0 cm and 43.0 cm TL with a modal length range from 19 to 22 cm representing 61.36% of the fish sample. A length–weight relationship using the total weight was found to be LogW = −2.2218 + 3.063LogL (R2 = 0.997 and using the gutted weight was LogW = −2.1549 + 3.003LogL (R2 = 0.995 hence exhibiting isometric growth. The average condition factors for different lengths were 0.76 ± 0.06. The chi-square of the overall sex ratio (male:female = 1:0.42 was significant at P < 0.01. The life span of this species is five years, with individuals of two years of age dominating the population. The different growth parameters were estimated at (K = 0.141, to = −0.271, L∞ = 80.65 cm, W∞ = 4151 g, ФL = 2.96 and ФW = 1.56. The natural mortality was 0.34, the M/K ratio was 2.38 and the variation of M by age model was also computed.

Repeated and Widespread Evolution of Bioluminescence in Marine Fishes.

Directory of Open Access Journals (Sweden)

Matthew P Davis

Full Text Available Bioluminescence is primarily a marine phenomenon with 80% of metazoan bioluminescent genera occurring in the world's oceans. Here we show that bioluminescence has evolved repeatedly and is phylogenetically widespread across ray-finned fishes. We recover 27 independent evolutionary events of bioluminescence, all among marine fish lineages. This finding indicates that bioluminescence has evolved many more times than previously hypothesized across fishes and the tree of life. Our exploration of the macroevolutionary patterns of bioluminescent lineages indicates that the present day diversity of some inshore and deep-sea bioluminescent fish lineages that use bioluminescence for communication, feeding, and reproduction exhibit exceptional species richness given clade age. We show that exceptional species richness occurs particularly in deep-sea fishes with intrinsic bioluminescent systems and both shallow water and deep-sea lineages with luminescent systems used for communication.

Brain structure evolution in a basal vertebrate clade: evidence from phylogenetic comparative analysis of cichlid fishes

Directory of Open Access Journals (Sweden)

Kolm Niclas

2009-09-01

Full Text Available Abstract Background The vertebrate brain is composed of several interconnected, functionally distinct structures and much debate has surrounded the basic question of how these structures evolve. On the one hand, according to the 'mosaic evolution hypothesis', because of the elevated metabolic cost of brain tissue, selection is expected to target specific structures mediating the cognitive abilities which are being favored. On the other hand, the 'concerted evolution hypothesis' argues that developmental constraints limit such mosaic evolution and instead the size of the entire brain varies in response to selection on any of its constituent parts. To date, analyses of these hypotheses of brain evolution have been limited to mammals and birds; excluding Actinopterygii, the basal and most diverse class of vertebrates. Using a combination of recently developed phylogenetic multivariate allometry analyses and comparative methods that can identify distinct rates of evolution, even in highly correlated traits, we studied brain structure evolution in a highly variable clade of ray-finned fishes; the Tanganyikan cichlids. Results Total brain size explained 86% of the variance in brain structure volume in cichlids, a lower proportion than what has previously been reported for mammals. Brain structures showed variation in pair-wise allometry suggesting some degree of independence in evolutionary changes in size. This result is supported by variation among structures on the strength of their loadings on the principal size axis of the allometric analysis. The rate of evolution analyses generally supported the results of the multivariate allometry analyses, showing variation among several structures in their evolutionary patterns. The olfactory bulbs and hypothalamus were found to evolve faster than other structures while the dorsal medulla presented the slowest evolutionary rate. Conclusion Our results favor a mosaic model of brain evolution, as certain

Investigation of Aerodynamic Capabilities of Flying Fish in Gliding Flight

Science.gov (United States)

Park, H.; Choi, H.

In the present study, we experimentally investigate the aerodynamic capabilities of flying fish. We consider four different flying fish models, which are darkedged-wing flying fishes stuffed in actual gliding posture. Some morphological parameters of flying fish such as lateral dihedral angle of pectoral fins, incidence angles of pectoral and pelvic fins are considered to examine their effect on the aerodynamic performance. We directly measure the aerodynamic properties (lift, drag, and pitching moment) for different morphological parameters of flying fish models. For the present flying fish models, the maximum lift coefficient and lift-to-drag ratio are similar to those of medium-sized birds such as the vulture, nighthawk and petrel. The pectoral fins are found to enhance the lift-to-drag ratio and the longitudinal static stability of gliding flight. On the other hand, the lift coefficient and lift-to-drag ratio decrease with increasing lateral dihedral angle of pectoral fins.

Kinematics and energetic benefits of schooling in the labriform fish, striped surfperch Embiotoca lateralis

DEFF Research Database (Denmark)

Johansen, J. L.; Vaknin, R.; Steffensen, John Fleng

2010-01-01

Schooling can provide fish with a number of behavioural and ecological advantages, including increased food supply and reduced predator risk. Previous work suggests that fish swimming using body and caudal fin locomotion may also experience energetic advantages when trailing behind neighbours......, based on correlations between swimming speeds and pectoral fin beat frequency and between swimming speeds and oxygen consumption of solitary fish. In addition, leading individuals in a school were estimated to have higher oxygen consumption than solitary individuals swimming at the same speed, based....... However, little is known about the potential energetic advantages associated with schooling in fish that swim using their pectoral fins. Using the striped surfperch Embiotoca lateralis, a labriform fish that swims routinely with its pectoral fins, we found that pectoral fin beat frequencies were...

Hydrodynamic function of dorsal fins in spiny dogfish and bamboo sharks during steady swimming.

Science.gov (United States)

Maia, Anabela; Lauder, George V; Wilga, Cheryl D

2017-11-01

A key feature of fish functional design is the presence of multiple fins that allow thrust vectoring and redirection of fluid momentum to contribute to both steady swimming and maneuvering. A number of previous studies have analyzed the function of dorsal fins in teleost fishes in this context, but the hydrodynamic function of dorsal fins in freely swimming sharks has not been analyzed, despite the potential for differential functional roles between the anterior and posterior dorsal fins. Previous anatomical research has suggested a primarily stabilizing role for shark dorsal fins. We evaluated the generality of this hypothesis by using time-resolved particle image velocimetry to record water flow patterns in the wake of both the anterior and posterior dorsal fins in two species of freely swimming sharks: bamboo sharks ( Chiloscyllium plagiosum ) and spiny dogfish ( Squalus acanthias ). Cross-correlation analysis of consecutive images was used to calculate stroke-averaged mean longitudinal and lateral velocity components, and vorticity. In spiny dogfish, we observed a velocity deficit in the wake of the first dorsal fin and flow acceleration behind the second dorsal fin, indicating that the first dorsal fin experiences net drag while the second dorsal fin can aid in propulsion. In contrast, the wake of both dorsal fins in bamboo sharks displayed increased net flow velocity in the majority of trials, reflecting a thrust contribution to steady swimming. In bamboo sharks, fluid flow in the wake of the second dorsal fin had higher absolute average velocity than that for first dorsal fin, and this may result from a positive vortex interaction between the first and second dorsal fins. These data suggest that the first dorsal fin in spiny dogfish has primarily a stabilizing function, while the second dorsal fin has a propulsive function. In bamboo sharks, both dorsal fins can contribute thrust and should be considered as propulsive adjuncts to the body during steady

Experimental observation of G banding verifying X-ray workers' chromosome translocation detected by FISH

International Nuclear Information System (INIS)

Sun Yuanming; Li Jin; Wang Qin; Tang Weisheng; Wang Zhiquan

2002-01-01

Objective: FISH is the most effective way of detecting chromosome aberration and many factors affect its accuracy. G-banding is used to verify the results of early X-ray workers' chromosome translocation examined by FISH. Methods: The chromosome translocations of early X-ray workers have been analysed by FISH (fluorescence in situ hybridization) and G-banding, yields of translocation treated with statistics. Results: The chromosome aberrations frequencies by tow methods are closely related. Conclusion: FISH is a feasible way to analyse chromosome aberrations of X-ray workers and reconstruct dose

The fish fauna of Anambra river basin, Nigeria: species abundance and morphometry

Directory of Open Access Journals (Sweden)

Gregory Ejikeme Odo

2009-06-01

Full Text Available The fish yields of most Nigeria inland waters are generally on the decline for causes that may range from inadequate management of the fisheries to degradation of the water bodies. Sustainable exploitation requires knowledge of the ichthyofaunal composition in the water bodies. We did a survey of fish species in Anambra river basin for 22 months. Fish samples were collected using four different gears -hook and line of size 13, caste nets, gill nets, and cages of mesh sizes of 50mm, 75mm, and 100mm each. We recorded 52 fish species belonging to 17 families: 171, 236, and 169 individuals at Ogurugu, Otuocha, and Nsugbe stations respectively. Two families, Characidae, 19.5 %, and Mochokidae, 11.8%, constituted the dominant fish families in the river. The dominant fish species were Citherinus citherius, 9.02%, and Alestes nurse, 7.1%. Other fish species with significant abundance were Synodontis clarias 6.9%, Macrolepidotus curvier 5.7%, Labeo coubie 5.4%, Distichodus rostrtus 4.9%, and Schilbe mystus 4.5%. The meristic features of the two most abundant fish species caught are as follows: Citharinus citharius dorsal fins 20, anal fins 30, caudal fins 21, pectoral fins, 9 and 8 ventral fins, and Alestes nurse 10 dorsal fins, 14 anal fins, 31 caudal fins, 7 pectoral fins and 6 ventral fins. The morphometric features of the two most abundant fish species are Citharinus citharius total length 300mm, standard length 231mm, head length 69mm, body length 101mm, body girth 176 mm, body weight 900mg. Alestes nurse total length 200, standard length 140mm, head length 60mm, body length 80mm, body girth120mm, body weight 400mg. The most abundant animal utilizing the basin was Ardea cinerea(D3 with 22.2% occurrence (D4 and this was followed by Caprini with 13.51%, and Varanus niloticus, 10.04%. The least abundant animals utilizing basin were Chephalophus rufilatus, and Erythrocebus patas, with 0.58% each of occurrence. Rev. Biol. Trop. 57 (1-2: 177-186. Epub

The phylogenetic intrarelationships of spiny-rayed fishes (Acanthomorpha, Teleostei, Actinopterygii: fossil taxa increase the congruence of morphology with molecular data

Directory of Open Access Journals (Sweden)

Donald Davesne

2016-11-01

Full Text Available Acanthomorpha (spiny-rayed fishes is a clade of teleosts that includes more than 15 000 extant species. Their deep phylogenetic intrarelationships, first reconstructed using morphological characters, have been extensively revised with molecular data. Moreover, the deep branches of the acanthomorph tree are still largely unresolved, with strong disagreement between studies. Here, we review the historical propositions for acanthomorph deep intrarelationships and attempt to resolve their earliest branching patterns using a new morphological data matrix compiling and revising characters from previous studies. The taxon sampling we use constitutes a first attempt to test all previous hypotheses (molecular and morphological alike with morphological data only. Our sampling also includes Late Cretaceous fossil taxa, which yield new character state combinations that are absent in extant taxa. Analysis of the complete morphological data matrix yields a new topology that shows remarkable congruence with the well-supported molecular results. Lampridiformes (oarfishes and allies are the sister to all other acanthomorphs. Gadiformes (cods and allies and Zeiformes (dories form a clade with Percopsiformes (trout-perches and the enigmatic Polymixia (beardfish and Stylephorus (tube-eye. Ophidiiformes (cusk-eels and allies and Batrachoidiformes (toadfishes are nested within Percomorpha, the clade that includes most of modern acanthomorph diversity. These results provide morphological synapomorphies and independent corroboration of clades previously only recovered from molecular data, thereby suggesting the emergence of a congruent picture of acanthomorph deep intrarelationships. Fossil taxa play a critical role in achieving this congruence, since a very different topology is found when they are excluded from the analysis.

The heartstrings mutation in zebrafish causes heart/fin Tbx5 deficiency syndrome.

Science.gov (United States)

Garrity, Deborah M; Childs, Sarah; Fishman, Mark C

2002-10-01

Holt-Oram syndrome is one of the autosomal dominant human "heart-hand" disorders, with a combination of upper limb malformations and cardiac defects. Holt-Oram syndrome is caused by mutations in the TBX5 gene, a member of a large family of T-box transcription factors that play important roles in cell-type specification and morphogenesis. In a screen for mutations affecting zebrafish cardiac function, we isolated the recessive lethal mutant heartstrings, which lacks pectoral fins and exhibits severe cardiac dysfunction, beginning with a slow heart rate and progressing to a stretched, non-functional heart. We mapped and cloned the heartstrings mutation and find it to encode the zebrafish ortholog of the TBX5 gene. The heartstrings mutation causes premature termination at amino acid 316. Homozygous mutant embryos never develop pectoral fin buds and do not express several markers of early fin differentiation. The total absence of any fin bud differentiation distinguishes heartstrings from most other mutations that affect zebrafish fin development, suggesting that Tbx5 functions very early in the pectoral fin induction pathway. Moderate reduction of Tbx5 by morpholino causes fin malformations, revealing an additional early requirement for Tbx5 in coordinating the axes of fin outgrowth. The heart of heartstrings mutant embryos appears to form and function normally through the early heart tube stage, manifesting only a slight bradycardia compared with wild-type siblings. However, the heart fails to loop and then progressively deteriorates, a process affecting the ventricle as well as the atrium. Relative to mammals, fish require lower levels of Tbx5 to produce malformed appendages and display whole-heart rather than atrial-predominant cardiac defects. However, the syndromic deficiencies of tbx5 mutation are remarkably well retained between fish and mammals.

A new cichlid fish in the Sahara: The Ounianga Serir lakes (Chad), a biodiversity hotspot in the desert.

Science.gov (United States)

Trape, Sébastien

In the rare perennial bodies of water of the Sahara desert, only a few fish species have survived to increasing aridification since the end of the last humid period at the Holocene, approximately 5000 years BP. Here, I report the occurrence of an undescribed haplochomine cichlid fish in Lake Boukou, one of the seven Ounianga Serir lakes (Chad). These lakes are located in one of the most arid areas of the Sahara desert, but they persist by virtue of subsurface inflow of fresh groundwater from a large fossil aquifer. Astatotilapia tchadensis sp. nov. is characterized by a black bar between eye and corner of mouth, rounded orange spots on anal fin, scales ctenoid, lower limb of first gill arch with 7-8 gill rackers, dorsal fin with 13-14 spines and 9-11 soft rays, anal fin with 3 spines and 8-9 soft rays, 29 or 30 lateral line scales, and lower pharyngeal dentition with enlarged molariform teeth. The new species is easily distinguished from A. desfontainii and A. flaviijosephii, the northernmost haplochromine species currently isolated from its other group members, and appears close to an unnamed species of Lake Chad basin. Ounianga Serir lakes and especially Lake Boukou present a remarkable diversity of fish, the highest known in the Sahara desert with a total of at least six fish species belonging to six genera and three families. They also constitute an exceptional natural landscape inscribed on the UNESCO world heritage list in 2012 and a biodiversity hotspot for desert vertebrate species. Copyright © 2016 Académie des sciences. Published by Elsevier SAS. All rights reserved.

Hydrodynamic study of freely swimming shark fish propulsion for marine vehicles using 2D particle image velocimetry.

Science.gov (United States)

Babu, Mannam Naga Praveen; Mallikarjuna, J M; Krishnankutty, P

Two-dimensional velocity fields around a freely swimming freshwater black shark fish in longitudinal (XZ) plane and transverse (YZ) plane are measured using digital particle image velocimetry (DPIV). By transferring momentum to the fluid, fishes generate thrust. Thrust is generated not only by its caudal fin, but also using pectoral and anal fins, the contribution of which depends on the fish's morphology and swimming movements. These fins also act as roll and pitch stabilizers for the swimming fish. In this paper, studies are performed on the flow induced by fins of freely swimming undulatory carangiform swimming fish (freshwater black shark, L  = 26 cm) by an experimental hydrodynamic approach based on quantitative flow visualization technique. We used 2D PIV to visualize water flow pattern in the wake of the caudal, pectoral and anal fins of swimming fish at a speed of 0.5-1.5 times of body length per second. The kinematic analysis and pressure distribution of carangiform fish are presented here. The fish body and fin undulations create circular flow patterns (vortices) that travel along with the body waves and change the flow around its tail to increase the swimming efficiency. The wake of different fins of the swimming fish consists of two counter-rotating vortices about the mean path of fish motion. These wakes resemble like reverse von Karman vortex street which is nothing but a thrust-producing wake. The velocity vectors around a C-start (a straight swimming fish bends into C-shape) maneuvering fish are also discussed in this paper. Studying flows around flapping fins will contribute to design of bioinspired propulsors for marine vehicles.

Putative relationships among inseminating and externally fertilizing characids, with a description of a new genus and species of Brazilian inseminating fish bearing an anal-fin gland in males (Characiformes: Characidae

Directory of Open Access Journals (Sweden)

Stanley H. Weitzman

Full Text Available A new inseminating fish species of the family Characidae, Bryconadenos tanaothoros, from tributaries of the upper rio Xingu and upper rio Tapajós basins, Mato Grosso, Brazil is described as the type species of a new genus. This new species and the genus are characterized by a glandular organ on the anterior region of the anal fin of sexually mature males, curved lower jaw teeth, and an inseminating reproductive mode. This new genus is hypothesized as most closely related to Attonitus, a genus with three inseminating species from Peru. Bryconadenos and Attonitus are suggested as related to certain inseminating, but undescribed characid species of uncertain relationships that are similar in certain respects to species of the glandulocaudine Planaltina and to the inseminating species of Knodus. These and a few other inseminating characids are included in a previous tentative characid subgroup designated as Clade A. No species among a relatively small sample of the many species of the Clade A genus Bryconamericus were found inseminating, except Bryconamericus pectinatus. However, newly collected specimens of B. pectinatus were found to have caudal-fin squamation like that of the species of Knodus and this species is here tentatively referred to Knodus. Our investigations indicate that at least several species of Knodus, including the type species, Knodus meridae, are not inseminating, but we found two inseminating apparently new characid species that currently would be referred to Knodus. These species lack the derived anal-fin rays present in the males of K. pectinatus. Other Clade A taxa known to be inseminating, such as two species of the large genus Creagrutus, three species of Monotocheirodon (two undescribed, and the species and genera of the characid subfamily Glandulocaudinae are briefly discussed regarding possible relationships to Attonitus and Bryconadenos. The anatomical aspects of the primary and secondary sexual characteristics of

ENERGETIC EXTREMES IN REEF FISH OCCUPYING HARSH HABITATS

DEFF Research Database (Denmark)

Steffensen, John Fleng

2009-01-01

document how relatively small changes in fin morphology has afforded some coral reef fish taxa with exceptional locomotor performance and energetic efficiency, and how this key attribute may have played a key role in the evolution and ecology of several diverse Indo-Pacific reef fish families. Using......-finned counterparts. We discuss how such differences in locomotor efficiency are pivotal to the habitat-use of these fishes, and how eco-energetic models may be used to provide new insights into spatial variations in fish demography and ecology among coral reef habitat zones....

Fatty fish intake and attention performance in 14-15 year old adolescents: FINS-TEENS - a randomized controlled trial.

Science.gov (United States)

Handeland, Katina; Øyen, Jannike; Skotheim, Siv; Graff, Ingvild E; Baste, Valborg; Kjellevold, Marian; Frøyland, Livar; Lie, Øyvind; Dahl, Lisbeth; Stormark, Kjell M

2017-10-02

Fatty fish is the dominant dietary source of n-3 LCPUFAs but it also contains other micronutrients considered important for brain development and function. To our knowledge, the effect of fatty fish intake on cognitive function in adolescents has not been investigated in randomized controlled trials (RCTs) previously. The aim of the present trial was to investigate whether consumption of fatty fish meals three times per week for 12 weeks could alter attention performance in adolescents compared to similar meals with meat or n-3 LCPUFA supplements. In the Fish Intervention Studies-TEENS (FINS-TEENS), adolescents from eight secondary schools (n = 426; age: 14-15y) were individually randomized. Attention performance was assessed with the d2 test of attention. Differences between groups from pre to post intervention were assessed with linear mixed effect models and general estimates equation. The fish group was set as reference. Dietary compliance was recorded for each meal throughout the trial and controlled for in the adjusted analyses. The improvement in processing speed was significantly lower in the meat (-11.8; 95% CI: -23.3, -0.4) and supplement (-13.4; 95% CI: -24.9, -1.8) group compared to the fish group (reference). The supplement group also showed inferior improvement in total performance (-10.4; 95% CI: -20.0, -0.7) compared to the fish group (reference). The results were slightly affected when controlling for dietary compliance. Omission errors decreased in the meat group compared to the fish group (Incidence rate ratio = 0.85; 95% CI: 0.74, 0.98), but the difference disappeared when controlling for dietary compliance. We observed a small beneficial effect of fatty fish, compared to meat meals and supplements on processing speed. However, these results are difficult to interpret due to low dietary compliance. This study shows that different taste preferences among participants is challenging in intervention trials with food. A prospective cohort

Mechanical design, fabrication, and test of biomimetic fish robot using LIPCA as artificial muscle

Science.gov (United States)

Wiguna, T.; Syaifuddin, M.; Park, Hoon C.; Heo, S.

2006-03-01

This paper presents a mechanical design, fabrication and test of biomimetic fish robot using the Lightweight Piezocomposite Curved Actuator (LIPCA). We have designed a mechanism for converting actuation of the LIPCA into caudal fin movement. This linkage mechanism consists of rack-pinion system and four-bar linkage. We also have tested four types of caudal fin in order to examine effect of different shape of caudal fin on thrust generation by tail beat. Subsequently, based on the caudal fin test, four caudal fins which resemble fish caudal fin shapes of ostraciiform, subcarangiform, carangiform and thunniform, respectively, are attached to the posterior part of the robotic fish. The swimming test using 300 V pp input with 1 Hz to 1.5 Hz frequency was conducted to investigate effect of changing tail beat frequency and shape of caudal fin on the swimming speed of the robotic fish. The maximum swimming speed was reached when the device was operated at its natural swimming frequency. At the natural swimming frequency 1 Hz, maximum swimming speeds of 1.632 cm/s, 1.776 cm/s, 1.612 cm/s and 1.51 cm/s were reached for ostraciiform-, subcarangiform-, carangiform- and thunniform-like caudal fins, respectively. Strouhal numbers, which are a measure of thrust efficiency, were calculated in order to examine thrust performance of the present biomimetic fish robot. We also approximated the net forward force of the robotic fish using momentum conservation principle.

Model identification and controller design of a fish-like robot

Science.gov (United States)

Ariyanto, Irfan; Kang, Taesam; Chan, Wai Leung; Lee, Youngjae

2007-04-01

Robotic fish is an interesting and prospective subject to develop. The simplest fish swimming mode to be mimicked for fish robots is the ostraciiform mode which only requires caudal fin flapping. An almost submerged ostraciiform fish robot was constructed to study its swimming characteristics. The swimming direction can be controlled by changing the mean angle of caudal fin oscillation. Experiments were conducted to study the behavior of the fish robot and in particular, the transfer function between swimming path angular rate and mean angle of the caudal fin oscillation were identified. Error to signal ratio quantity was used to determine how well the model fits with the experimental data. This identification model was used to design a 2-degree-of-freedom PID controller that meets some specific requirements to improve the steering performance.

Design of the FINS-TEENS study: A randomized controlled trial assessing the impact of fatty fish on cognitive performance in adolescents.

Science.gov (United States)

Skotheim, Siv; Dahl, Lisbeth; Handeland, Katina; Frøyland, Livar; Lie, Øyvind; Øyen, Jannike; Kjellevold, Marian; Stormark, Kjell Morten; Graff, Ingvild Eide

2017-08-01

To describe the rationale, study design, population and dietary compliance in a randomized controlled trial (RCT) investigating the effect of fatty fish on cognitive performance and mental health in adolescents. In the Fish Intervention Studies-TEENS (FINS-TEENS) study we individually randomized 478 adolescents (14-15-year-olds) from eight secondary schools in Norway to receive school meal lunches with fatty fish or meat or n-3 supplements three times a week for 12 weeks. Demographic factors, psychological tests and biological measures were collected pre-and post-intervention. Duplicate portions of lunch meals were collected and individual intake recorded throughout the study. In total, 481 out of 785 adolescents (61%) agreed to participate and 34 (7%) dropped out. Breakfast consumption was the only group difference in background characteristics. Analyses of selected nutrients in the lunch meals showed higher levels of n-3 fatty acids, vitamin D and n-6 fatty acids in the fish compared to the meat meals. Dietary compliance (score 0-144) revealed that the intake in the Fish group (mean = 59, standard deviation (SD) = 35) were lower than in the Meat group (mean = 83, SD = 31, p school-based setting. The results also emphasize the importance of collecting detailed records of dietary compliance, as this information is important when interpreting and analysing the outcome of dietary interventions.

Life-long preservation of the regenerative capacity in the fin and heart in zebrafish

Directory of Open Access Journals (Sweden)

Junji Itou

2012-06-01

The zebrafish is a widely used model animal to study the regeneration of organs, such as the fin and heart. Their average lifetime is about 3 years, and recent studies have shown that zebrafish exhibit aging-related degeneration, suggesting the possibility that aging might affect regenerative potential. In order to investigate this possibility, we compared regeneration of the fin and heart after experimental amputation in young (6–12 month old and old (26–36 month old fish. Comparison of recovery rate of the caudal fin, measured every two or three days from one day post amputation until 13 days post amputation, show that fins in young and old fish regenerate at a similar rate. In the heart, myocardium regeneration and cardiomyocyte proliferation occurred similarly in the two groups. Moreover, neo-vascularization, as well as activation of fibroblast growth factor signaling, which is required for neo-vascularization, occurred similarly. The epicardial tissue is a thin layer tissue that covers the heart, and starts to express several genes immediately in response to injury. The expression of epicardial genes, such as wt1b and aldh1a2, in response to heart injury was comparable in two groups. Our results demonstrate that zebrafish preserve a life-long regenerative ability of the caudal fin and heart.

Fully-Implicit Navier-Stokes (FIN-S)

Science.gov (United States)

Kirk, Benjamin S.

2010-01-01

FIN-S is a SUPG finite element code for flow problems under active development at NASA Lyndon B. Johnson Space Center and within PECOS: a) The code is built on top of the libMesh parallel, adaptive finite element library. b) The initial implementation of the code targeted supersonic/hypersonic laminar calorically perfect gas flows & conjugate heat transfer. c) Initial extension to thermochemical nonequilibrium about 9 months ago. d) The technologies in FIN-S have been enhanced through a strongly collaborative research effort with Sandia National Labs.

Undulatory fish swimming : from muscles to flow

NARCIS (Netherlands)

Müller, U.K.; Leeuwen, van J.L.

2006-01-01

Undulatory swimming is employed by many fish for routine swimming and extended sprints. In this biomechanical review, we address two questions: (i) how the fish's axial muscles power swimming; and (ii) how the fish's body and fins generate thrust. Fish have adapted the morphology of their axial

Performance Analysis of a Self-Propelling Flat Plate Fin with Joint Compliance

Science.gov (United States)

Reddy, N. Srinivasa; Sen, Soumen; Pal, Sumit; Shome, Sankar Nath

2017-12-01

Fish fin muscles are compliant and they regulate the stiffness to suit different swimming conditions. This article attempts to understand the significance of presence of compliance in fin muscle with help of a flexible joint flat plate fin model. Blade element method is employed to model hydrodynamics and to compute the forces of interaction during motion of the plate within fluid. The dynamic model of self-propelling fin is developed through multi-body dynamics approach considering the hydrodynamic forces as external forces acting on the fin. The derived hydrodynamic model is validated with experiments on rigid flat plate fin. The effect of the joint stiffness and flapping frequency on the propulsion speed and efficiency is investigated through simulations using the derived and validated model. The propulsion efficiency is found to be highly influenced by the joint stiffness at a given flapping frequency. The fin attained maximum propulsion efficiency when the joint stiffness is tuned to a value at which flapping frequency matches near natural frequency of the fin. At this tuned joint stiffness and flapping frequency, the resulted Strouhal numbers are observed to fall within the optimum range (0.2 to 0.4) for maximized propulsion efficiency of flying birds and swimming aquatic animals reported in literature.

Swimming Performance of Toy Robotic Fish

Science.gov (United States)

Petelina, Nina; Mendelson, Leah; Techet, Alexandra

2015-11-01

HEXBUG AquaBotsTM are a commercially available small robot fish that come in a variety of ``species''. These models have varying caudal fin shapes and randomly-varied modes of swimming including forward locomotion, diving, and turning. In this study, we assess the repeatability and performance of the HEXBUG swimming behaviors and discuss the use of these toys to develop experimental techniques and analysis methods to study live fish swimming. In order to determine whether these simple, affordable model fish can be a valid representation for live fish movement, two models, an angelfish and a shark, were studied using 2D Particle Image Velocimetry (PIV) and 3D Synthetic Aperture PIV. In a series of experiments, the robotic fish were either allowed to swim freely or towed in one direction at a constant speed. The resultant measurements of the caudal fin wake are compared to data from previous studies of a real fish and simplified flapping propulsors.

Spiracular air breathing in polypterid fishes and its implications for aerial respiration in stem tetrapods

Science.gov (United States)

Graham, Jeffrey B.; Wegner, Nicholas C.; Miller, Lauren A.; Jew, Corey J.; Lai, N. Chin; Berquist, Rachel M.; Frank, Lawrence R.; Long, John A.

2014-01-01

The polypterids (bichirs and ropefish) are extant basal actinopterygian (ray-finned) fishes that breathe air and share similarities with extant lobe-finned sarcopterygians (lungfishes and tetrapods) in lung structure. They are also similar to some fossil sarcopterygians, including stem tetrapods, in having large paired openings (spiracles) on top of their head. The role of spiracles in polypterid respiration has been unclear, with early reports suggesting that polypterids could inhale air through the spiracles, while later reports have largely dismissed such observations. Here we resolve the 100-year-old mystery by presenting structural, behavioural, video, kinematic and pressure data that show spiracle-mediated aspiration accounts for up to 93% of all air breaths in four species of Polypterus. Similarity in the size and position of polypterid spiracles with those of some stem tetrapods suggests that spiracular air breathing may have been an important respiratory strategy during the fish-tetrapod transition from water to land.

Propulsion of a fin whale (Balaenoptera physalus): why the fin whale is a fast swimmer.

Science.gov (United States)

Bose, N; Lien, J

1989-07-22

Measurements of an immature fin whale (Balaenoptera physalus), which died as a result of entrapment in fishing gear near Frenchmans Cove, Newfoundland (47 degrees 9' N, 55 degrees 25' W), were made to obtain estimates of volume and surface area of the animal. Detailed measurements of the flukes, both planform and sections, were also obtained. A strip theory was developed to calculate the hydrodynamic performance of the whale's flukes as an oscillating propeller. This method is based on linear, two-dimensional, small-amplitude, unsteady hydrofoil theory with correction factors used to account for the effects of finite span and finite amplitude motion. These correction factors were developed from theoretical results of large-amplitude heaving motion and unsteady lifting-surface theory. A model that makes an estimate of the effects of viscous flow on propeller performance was superimposed on the potential-flow results. This model estimates the drag of the hydrofoil sections by assuming that the drag is similar to that of a hydrofoil section in steady flow. The performance characteristics of the flukes of the fin whale were estimated by using this method. The effects of the different correction factors, and of the frictional drag of the fluke sections, are emphasized. Frictional effects in particular were found to reduce the hydrodynamic efficiency of the flukes significantly. The results are discussed and compared with the known characteristics of fin-whale swimming.

Fluid dynamics of flapping aquatic flight in the bird wrasse: three-dimensional unsteady computations with fin deformation.

Science.gov (United States)

Ramamurti, Ravi; Sandberg, William C; Löhner, Rainald; Walker, Jeffrey A; Westneat, Mark W

2002-10-01

Many fishes that swim with the paired pectoral fins use fin-stroke parameters that produce thrust force from lift in a mechanism of underwater flight. These locomotor mechanisms are of interest to behavioral biologists, biomechanics researchers and engineers. In the present study, we performed the first three-dimensional unsteady computations of fish swimming with oscillating and deforming fins. The objective of these computations was to investigate the fluid dynamics of force production associated with the flapping aquatic flight of the bird wrasse Gomphosus varius. For this computational work, we used the geometry of the wrasse and its pectoral fin, and previously measured fin kinematics, as the starting points for computational investigation of three-dimensional (3-D) unsteady fluid dynamics. We performed a 3-D steady computation and a complete set of 3-D quasisteady computations for a range of pectoral fin positions and surface velocities. An unstructured, grid-based, unsteady Navier-Stokes solver with automatic adaptive remeshing was then used to compute the unsteady flow about the wrasse through several complete cycles of pectoral fin oscillation. The shape deformation of the pectoral fin throughout the oscillation was taken from the experimental kinematics. The pressure distribution on the body of the bird wrasse and its pectoral fins was computed and integrated to give body and fin forces which were decomposed into lift and thrust. The velocity field variation on the surface of the wrasse body, on the pectoral fins and in the near-wake was computed throughout the swimming cycle. We compared our computational results for the steady, quasi-steady and unsteady cases with the experimental data on axial and vertical acceleration obtained from the pectoral fin kinematics experiments. These comparisons show that steady state computations are incapable of describing the fluid dynamics of flapping fins. Quasi-steady state computations, with correct incorporation of

Hydraulic control of tuna fins: A role for the lymphatic system in vertebrate locomotion.

Science.gov (United States)

Pavlov, Vadim; Rosental, Benyamin; Hansen, Nathaniel F; Beers, Jody M; Parish, George; Rowbotham, Ian; Block, Barbara A

2017-07-21

The lymphatic system in teleost fish has genetic and developmental origins similar to those of the mammalian lymphatic system, which is involved in immune response and fluid homeostasis. Here, we show that the lymphatic system of tunas functions in swimming hydrodynamics. Specifically, a musculo-vascular complex, consisting of fin muscles, bones, and lymphatic vessels, is involved in the hydraulic control of median fins. This specialization of the lymphatic system is associated with fish in the family Scombridae and may have evolved in response to the demand for swimming and maneuvering control in these high-performance species. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Aqueous exposure to the progestin, levonorgestrel, alters anal fin development and reproductive behavior in the eastern mosquitofish (Gambusia holbrooki)

Science.gov (United States)

Frankel, Tyler E.; Meyer, Michael T.; Orlando, Edward F.

2016-01-01

Endogenous progestogens are important regulators of vertebrate reproduction. Synthetic progestins are components of human contraceptive and hormone replacement pharmaceuticals. Both progestogens and progestins enter the environment through a number of sources, and have been shown to cause profound effects on reproductive health in various aquatic vertebrates. Progestins are designed to bind human progesterone receptors, but they also have been shown to strongly activate androgen receptors in fish. Levonorgestrel (LNG) activates fish androgen receptors and induces development of male secondary sex characteristics in females of other species. Although behavior has been postulated to be a sensitive early indicator of exposure to certain environmental contaminants, no such research on the reproductive behavior of gestagen-exposed fish has been conducted to date. The goal of our study was to examine the exposure effects of a human contraceptive progestin, LNG, on the reproductive development and behavior of the viviparous eastern mosquitofish (Gambusia holbrooki). Internal fertilization is a requisite characteristic of viviparous species, and is enabled by an androgen driven elongation of the anal fin into the male gonopodium (i.e., phallus). In this study, we exposed adult mosquitofish to ethanol (EtOH control), 10 ng/L, and 100 ng/L LNG for 8 d using a static replacement exposure design. After 8 d, a subset of males and females from each treatment were examined for differences in the 4:6 anal fin ratio. In addition, paired social interaction trials were performed using individual control males and control females or females treated 10 ng/L or 100 ng/L LNG. Female mosquitofish exposed to LNG were masculinized as evidenced by the elongation of the anal fin rays, a feature normal to males and abnormal to females. LNG caused significant increases in the 4:6 anal fin ratios of female mosquitofish in both the 10 ng/L and 100 ng/L treatments, although these

Labriform propulsion in fishes: kinematics of flapping aquatic flight in the bird wrasse Gomphosus varius (Labridae)

Science.gov (United States)

Walker; Westneat

1997-01-01

Labriform, or pectoral fin, propulsion is the primary swimming mode for many fishes, even at high relative speeds. Although kinematic data are critical for evaluating hydrodynamic models of propulsion, these data are largely lacking for labriform swimmers, especially for species that employ an exclusively labriform mode across a broad range of speeds. We present data on pectoral fin locomotion in Gomphosus varius (Labridae), a tropical coral reef fish that uses a lift-based mechanism to fly under water at sustained speeds of 1­6 total body lengths s-1 (TL s-1). Lateral- and dorsal-view video images of three fish swimming in a flow tank at 1­4 TL s-1 were recorded at 60 Hz. From the two views, we reconstructed the three-dimensional motion of the center of mass, the fin tip and two fin chords for multiple fin beats of each fish at each of four speeds. In G. varius, the fin oscillates largely up and down: the stroke plane is tilted by approximately 20 ° from the vertical. Both frequency and the area swept by the pectoral fins increase with swimming speed. Interestingly, there are individual differences in how this area increases. Relative to the fish, the fin tip in lateral view moves along the path of a thin, inclined figure-of-eight. Relative to a stationary observer, the fin tip traces a sawtooth pattern, but the teeth are recumbent (indicating net backwards movement) only at the slowest speeds. Distal fin chords pitch nose downward during the downstroke and nose upward during the upstroke. Hydrodynamic angles of attack are largely positive during the downstroke and negative during the upstroke. The geometry of the fin and incident flow suggests that the fin is generating lift with large upward and small forward components during the downstroke. The negative incident angles during the upstroke suggest that the fin is generating largely thrust during the upstroke. In general, the large thrust is combined with a downward force during the upstroke, but the net

FTR83, a Member of the Large Fish-Specific finTRIM Family, Triggers IFN Pathway and Counters Viral Infection

Directory of Open Access Journals (Sweden)

Christelle Langevin

2017-05-01

Full Text Available Tripartite motif (TRIM proteins are involved in various cellular functions and constitute key factors of the antiviral innate immune response. TRIM proteins can bind viral particles directly, sending them to degradation by the proteasome, or ubiquitinate signaling molecules leading to upregulation of innate immunity. TRIM proteins are present in across metazoans but are particularly numerous in vertebrates where genes comprising a B30.2 domain have been often duplicated. In fish, a TRIM subset named finTRIM is highly diversified, with large gene numbers and clear signatures of positive selection in the B30.2 domain suggesting they may be involved in antiviral mechanisms. finTRIM provides a beautiful model to investigate the primordial implication of B30.2 TRIM subsets in the arsenal of vertebrate antiviral defenses. We show here that ftr83, a zebrafish fintrim gene mainly expressed in the gills, skin and pharynx, encodes a protein affording a potent antiviral activity. In vitro, overexpression of FTR83, but not of its close relative FTR82, induced IFN and IFN-stimulated gene expression and afforded protection against different enveloped and non-enveloped RNA viruses. The kinetics of IFN induction paralleled the development of the antiviral activity, which was abolished by a dominant negative IRF3 mutant. In the context of a viral infection, FTR83 potentiated the IFN response. Expression of chimeric proteins in which the B30.2 domain of FTR83 and the non-protective FTR82 had been exchanged, showed that IFN upregulation and antiviral activity requires both the Ring/BBox/Coiled coil domain (supporting E3 ubiquitin ligase and the B30.2 domain of FTR83. Finally, loss of function experiments in zebrafish embryos confirms that ftr83 mediates antiviral activity in vivo. Our results show that a member of the largest TRIM subset observed in fish upregulates type I IFN response and afford protection against viral infections, supporting that TRIMs are key

Development of low level 226Ra analysis for live fish using gamma-ray spectrometry

Science.gov (United States)

Chandani, Z.; Prestwich, W. V.; Byun, S. H.

2017-06-01

A low level 226Ra analysis method for live fish was developed using a 4π NaI(Tl) gamma-ray spectrometer. In order to find out the best algorithm for accomplishing the lowest detection limit, the gamma-ray spectrum from a 226Ra point was collected and nine different methods were attempted for spectral analysis. The lowest detection limit of 0.99 Bq for an hour counting occurred when the spectrum was integrated in the energy region of 50-2520 keV. To extend 226Ra analysis to live fish, a Monte Carlo simulation model with a cylindrical fish in a water container was built using the MCNP code. From simulation results, the spatial distribution of the efficiency and the efficiency correction factor for the live fish model were determined. The MCNP model will be able to be conveniently modified when a different fish or container geometry is employed as fish grow up in real experiments.

ENERGETIC EXTREMES IN A HOSTILE HABITAT: FISH LOCOMOTION ON WAVE-SWEPT CORAL REEFS

DEFF Research Database (Denmark)

Steffensen, John Fleng

2010-01-01

, and wing-like fins that generate lift-based thrust at high speed. Literally flying underwater, Stethojulis and other winged-fin species are the most abundant fish in wave-swept coral reef habitats. We discuss the extreme swimming performance of these reef fishes within the context of other non......-scombrid and scombrid fishes, and illustrate how such performance has contributed to their domination of shallow coral reef habitats worldwide....

The effect of school meals with fatty fish on adolescents' self-reported symptoms for mental health: FINS-TEENS - a randomized controlled intervention trial.

Science.gov (United States)

Skotheim, Siv; Handeland, Katina; Kjellevold, Marian; Øyen, Jannike; Frøyland, Livar; Lie, Øyvind; Eide Graff, Ingvild; Baste, Valborg; Stormark, Kjell Morten; Dahl, Lisbeth

2017-01-01

There is a growing body of evidence linking fish consumption and n-3 LCPUFAs to mental health. Still, the results from randomized trials with n-3 LCPUFAs show conflicting results, and it is possible that the combined effect of several nutrients in fish may explain the observed associations. To aim of the present study was to investigate if school meals with fatty fish three times per week for 12 weeks could alter mental health in a sample of typically developing adolescents. In the Fish Intervention Studies-TEENS (FINS-TEENS), adolescents from eight secondary schools (n=425) in Norway, were randomized to receive school meals with fatty fish, meat or n-3 LCPUFA supplements. Mental health was assessed with the Strengths and Difficulties Questionnaire (SDQ) and the differences between the groups were assessed with linear mixed effect models, unadjusted and adjusted for baseline and dietary compliance. The results showed no effects of school meals with fatty fish compared to similar meals with meat or n-3 LCPUFAs on the adolescents' self-reported symptom scores for mental health. Among adolescents scoring above the SDQ cut-offs (high-scorers), the fish- improved less than the meat group in the self-reported symptom scores for total difficulties- and emotional problems. However, the findings should be regarded as preliminary, as the analyses for the high-scorer group were underpowered. In conclusion, serving school meals with fatty fish did not alter mental health in a typically developing sample of adolescents. It is possible that serving healthy school meals with meat is more beneficial than similar meals with fatty fish in adolescents scoring high on mental health problems. However, the results should be seen as preliminary, as the dietary compliance in the fish group was low and the analyses in the high score group underpowered. Thus, further studies should investigate the associations between fish consumption and adolescents' mental health.

A Novel Implementation of a Flexible Robotic Fin Actuated by Shape Memory Alloy

Institute of Scientific and Technical Information of China (English)

Qin Yan; Lei Wang; Bo Liu; Jie Yang; Shiwu Zhang

2012-01-01

In this paper,study of a novel flexible robotic-fin actuated by Shape Memory Alloy (SMA) is presented.The developed robotic fin is capable of implementing various 3-Dimensional (3D) motions,which plays an important role in robot propulsion and maneuverability.Firstly,the morphological and mechanics parameters of a real pectoral fin from a carp are investigated.Secondly,a detailed design of the flexible pectoral fin driven by SMA is presented according to the previous morphological and mechanics analyses.Thirdly,a simplified theoretical model on the SMA fin plate is derived.The thermodynamics of the SMA plate and the relationship between curvature and phase transformation are analyzed.Finally,several simulations and model experiments are conducted according to the previous analyses.The results of the experiments are useful for the control of the robotic fin.The experimental results reveal that the SMA actuated fin ray has a good actuating performance.

Cyanobacterial Neurotoxin β-N-Methylamino-L-alanine (BMAA in Shark Fins

Directory of Open Access Journals (Sweden)

John Pablo

2012-02-01

Full Text Available Sharks are among the most threatened groups of marine species. Populations are declining globally to support the growing demand for shark fin soup. Sharks are known to bioaccumulate toxins that may pose health risks to consumers of shark products. The feeding habits of sharks are varied, including fish, mammals, crustaceans and plankton. The cyanobacterial neurotoxin β-N-methylamino-L-alanine (BMAA has been detected in species of free-living marine cyanobacteria and may bioaccumulate in the marine food web. In this study, we sampled fin clips from seven different species of sharks in South Florida to survey the occurrence of BMAA using HPLC-FD and Triple Quadrupole LC/MS/MS methods. BMAA was detected in the fins of all species examined with concentrations ranging from 144 to 1836 ng/mg wet weight. Since BMAA has been linked to neurodegenerative diseases, these results may have important relevance to human health. We suggest that consumption of shark fins may increase the risk for human exposure to the cyanobacterial neurotoxin BMAA.

Vitrification of caudal fin explants from zebrafish adult specimens.

Science.gov (United States)

Cardona-Costa, J; Roig, J; Perez-Camps, M; García-Ximénez, F

2006-01-01

No data on vitrification of tissue samples are available in fishes. Three vitrification solutions were compared: V1: 20% ethylene glycol and 20% dimethyl sulphoxide; V2: 25% propylene glycol and 20% dimethyl sulphoxide, and; V3: 20% propylene glycol and 13% methanol, all three prepared in Hanks' buffered salt solution plus 20 percent FBS, following the same one step vitrification procedure developed in mammals. Caudal fin tissue pieces were vitrified into 0.25 ml plastic straws in 30s and stored in liquid nitrogen for 3 days minimum, warmed (10s in nitrogen vapour and 5s in a 25 degree C water bath) and cultured (L-15 plus 20% FBS at 28.5 degree C). At the third day of culture, both attachment and outgrowing rates were recorded. V3 led to the worst results (8% of attachment rate). V1 and V2 allow higher attachment rates (V1: 63% vs V2: 50%. P < 0.05) but not significantly different outgrowing rates (83% to 94%). Vitrification of caudal fin pieces is advantageous in fish biodiversity conservation, particularly in the wild, due to the simplicity of procedure and equipment.

Magnetic fish-robot based on multi-motion control of a flexible magnetic actuator.

Science.gov (United States)

Kim, Sung Hoon; Shin, Kyoosik; Hashi, Shuichiro; Ishiyama, Kazushi

2012-09-01

This paper presents a biologically inspired fish-robot driven by a single flexible magnetic actuator with a rotating magnetic field in a three-axis Helmholtz coil. Generally, magnetic fish-robots are powered by alternating and gradient magnetic fields, which provide a single motion such as bending the fish-robot's fins. On the other hand, a flexible magnetic actuator driven by an external rotating magnetic field can create several gaits such as the bending vibration, the twisting vibration, and their combination. Most magnetic fish-like micro-robots do not have pectoral fins on the side and are simply propelled by the tail fin. The proposed robot can swim and perform a variety of maneuvers with the addition of pectoral fins and control of the magnetic torque direction. In this paper, we find that the robot's dynamic actuation correlates with the magnetic actuator and the rotating magnetic field. The proposed robot is also equipped with new features, such as a total of six degrees of freedom, a new control method that stabilizes posture, three-dimensional swimming, a new velocity control, and new turning abilities.

Magnetic fish-robot based on multi-motion control of a flexible magnetic actuator

International Nuclear Information System (INIS)

Kim, Sung Hoon; Hashi, Shuichiro; Ishiyama, Kazushi; Shin, Kyoosik

2012-01-01

This paper presents a biologically inspired fish-robot driven by a single flexible magnetic actuator with a rotating magnetic field in a three-axis Helmholtz coil. Generally, magnetic fish-robots are powered by alternating and gradient magnetic fields, which provide a single motion such as bending the fish-robot's fins. On the other hand, a flexible magnetic actuator driven by an external rotating magnetic field can create several gaits such as the bending vibration, the twisting vibration, and their combination. Most magnetic fish-like micro-robots do not have pectoral fins on the side and are simply propelled by the tail fin. The proposed robot can swim and perform a variety of maneuvers with the addition of pectoral fins and control of the magnetic torque direction. In this paper, we find that the robot's dynamic actuation correlates with the magnetic actuator and the rotating magnetic field. The proposed robot is also equipped with new features, such as a total of six degrees of freedom, a new control method that stabilizes posture, three-dimensional swimming, a new velocity control, and new turning abilities. (paper)

Decontamination of salmonella from the coastal fish meals by 60Co γ ray irradiation

International Nuclear Information System (INIS)

Saheki, Kazuaki; Konno, Kenjiro; Sato, Takae; Kawabata, Toshiharu.

1988-01-01

The decontamination fo salmonellae from fish meal samples by irradiation which 60 Co γ ray was examined. Sixteen strains of Salmonella were used. A composite fish meal sample was prepared by mixing with different coastal meals, and after radiation sterilization at a dose of 20 kGy 60 Co γ ray, which was employed as the salmonella-free meal sample. D 10 values of test strains determined in buffered saline were found to range from 0.08 to 0.36 kGy, and inactivation factors at a dose of 1 kGy ranged from 10 2.8 to 10 13 . D 10 values of test strains determined in the salmonella-free meal sample ranged from 0.59 to 1.64 kGy, and the inactivation factors at a dose of 10 kGy were found to range from 10 6.1 to 10 17 . Interestingly the D 10 values of salmonellae determined in fish meal samples were 10 times as much compared with those determined in buffered saline. From the commercial aspects of coastal fish meal production, destruction of salmonellae in fish meals by 60 Co γ ray irradiation was found to be much more practical than other methods such as dry heating and ethylene oxide fumigation. (author)

INVESTIGATING PECTORAL SHAPES AND LOCOMOTIVE STRATEGIES FOR CONCEPTUAL DESIGNING BIO-INSPIRED ROBOTIC FISH

Directory of Open Access Journals (Sweden)

A. I. MAINONG

2017-01-01

Full Text Available This paper describes the performance analysis of a conceptual bio-inspired robotic fish design, which is based on the morphology similar to the boxfish (Ostracion melagris. The robotic fish prototype is driven by three micro servos; two on the pectoral fins, and one on the caudal fin. Two electronic rapid prototyping boards were employed; one for the movement of robotic fish, and one for the force sensors measurements. The robotic fish were built using fused deposition modeling (FDM, more popularly known as the 3D printing method. Several designs of pectoral fins (rectangular, triangular and quarter-ellipse with unchanging the value of aspect ratio (AR employed to measure the performance of the prototype robotic fish in terms of hydrodynamics, thrust and maneuvering characteristics. The analysis of the unmanned robotic system performance is made experimentally and the results show that the proposed bioinspired robotic prototype opens up the possibility of design optimization research for future work.

Effect of the Curved Fin Top Edge on the Electrical Characteristics of FinFETs.

Science.gov (United States)

Ahn, Joonsung; Kim, Tae Whan

2018-03-01

The effect of the curved fin top edge on the electrical characteristics of FinFETs was investigated. The curvature radius of the fin top edge for the FinFETs was changed from 0 to 5 nm in order to determine the optimum condition of the electrical characteristics for the devices. The on-current level of the FinFETs with a curvature radius of 5 nm of fin top edge was 24.45% larger than that of the FinFETs with a cuboid fin. The electron current density and the electron mobility of the fin top edge for the FinFETs were larger than those for the FinFETs with a cuboid fin. The electrical characteristics of the FinFETs with a curvature radius of 5 nm for the fin top edge showed the best performance due to the largest expansion of the effective channel region.

Viral replication in excised fin tissues (VREFT) corresponds with prior exposure of Pacific herring, Clupea pallasii (Valenciennes), to viral haemorrhagic septicaemia virus (VHSV)

Science.gov (United States)

Grady, C.A.; Gregg, J.L.; Wade, R.M.; Winton, J.R.; Hershberger, P.K.

2011-01-01

Procedures for a viral replication in excised fin tissue (VREFT) assay were adapted to Pacific herring, Clupea pallasii, and optimized both to reduce processing time and to provide the greatest resolution between na??ve herring and those previously exposed to viral haemorrhagic septicaemia virus (VHSV), Genogroup IVa. The optimized procedures included removal of the left pectoral fin from a euthanized fish, inoculation of the fin with >105 plaque-forming units (PFU) mL-1 VHSV for 1 h, rinsing the fin in fresh medium six times to remove unadsorbed virions, incubation of the fin in fresh medium for 4 days and enumeration of the viral titre in a sample of the incubation medium by plaque assay. The optimized VREFT assay was effective at identifying the prior exposure history of laboratory-reared Pacific herring to VHSV. The geometric mean VREFT value was significantly greater (P < 0.01) among na??ve herring (1.2 ?? 103 PFU mL-1) than among groups that survived exposure to VHSV (1.0-2.9 ?? 102 PFU mL-1); additionally, the proportion of cultures with no detectable virus was significantly greater (P = 0.0002) among fish that survived exposure to VHSV (39-47%) than among na??ve fish (3.3%). The optimized VREFT assay demonstrates promise for identifying VHSV exposure history and forecasting disease potential in populations of wild Pacific herring. ?? 2010 Blackwell Publishing Ltd.

Fins coloration of perch in relation to external activity concentration of radionuclides

Energy Technology Data Exchange (ETDEWEB)

Yegoreichenkov, E.; Pryakhin, E. [Urals Research Center for Radiation Medicine (Russian Federation); Rudolfsen, G. [Norwegian Radiation Protection Authority and University of Tromsoe (Norway)

2014-07-01

The Techa River is significantly polluted by radionuclides. This time the content of {sup 90}Sr varies from 5 Bq/l in water of lower Techa to 40 Bq/l in higher Techa, and the concentration of {sup 137}Cs fluctuates from background content to 0,5 Bq/l, and tritium from 100 Bq/l to 450 Bq/l. Miass River are not polluted in the same extent. The perch in these rivers are suitable for examine the potential effect of environmental perturbation on carotenoid based coloration. As vertebrates could not produce carotenoids themselves, and would use more carotenoids due to oxidative stress when exposed radiation, we hypothesized that fish caught in upper part of Techa River will be more pale than fish from lower part and the control river Miass. We used a cost effective method to estimate coloration by photographing the fins in standardized setting. The measuring of fish fins as performed under standardized condition by Adobe Photoshop software in color spaces CIE 1976 L*a*b* and sRGB IEC61966-2.1 was used. In sRGB color space the values of Red, Green, Blue channels were measured and an average wave length was calculated as a function of three elementary light streams of different intensity, appeared as reflection from a fin. In L*a*b color space the values of *a and *b channels shows the position of a color in a color space. To evaluate the red color of a perch fin the most usable channel is the *a channel which shows the position of the color on the red-green axis. Due to low sample size we pooled males and females in our analysis. We used three different station in the Techa: RT-1 in the higher Techa, RT-2 in the middle Techa, and RT-3 in lower Techa. As a control group was taken the fish from Miass river (RM station). Our results shows that perch from RT-3 (570.7 nm) significantly differ in coloration from the perch from RT-2 and RT-1 (p=0.00001 and p=0.0014 respectively, hereinafter used Kruskal-Wallis rank sum test with Nemenyi-Damico-Wolfe-Dunn test as post

On the Hydrodynamics of Anomalocaris Tail Fins.

Science.gov (United States)

Sheppard, K A; Rival, D E; Caron, J-B

2018-04-25

Anomalocaris canadensis, a soft-bodied stem-group arthropod from the Burgess Shale, is considered the largest predator of the Cambrian period. Thanks to a series of lateral flexible lobes along its dorso-ventrally compressed body, it is generally regarded as an efficient swimmer, well-adapted to its predatory lifestyle. Previous theoretical hydrodynamic simulations have suggested a possible optimum in swimming performance when the lateral lobes performed as a single undulatory lateral fin, comparable to the pectoral fins in skates and rays. However, the role of the unusual fan-like tail of Anomalocaris has not been previously explored. Swimming efficiency and maneuverability deduced from direct hydrodynamic analysis are here studied in a towing tank facility using a three-vane physical model designed as an abstraction of the tail fin. Through direct force measurements, it was found that the model exhibited a region of steady-state lift and drag enhancement at angles of attack greater than 25° when compared to a triangular-shaped reference model. This would suggest that the resultant normal force on the tail fin of Anomalocaris made it well-suited for turning maneuvers, giving it the ability to turn quickly and through small radii of curvature. These results are consistent with an active predatory lifestyle, although detailed kinematic studies integrating the full organism, including the lateral lobes, would be required to test the effect of the tail fin on overall swimming performance. This study also highlights a possible example of evolutionary convergence between the tails of Anomalocaris and birds, which, in both cases, are well-adapted to efficient turning maneuvers.

Evaluation of pathogenic fungi occurrence in traumatogenic structures of freshwater fish

Directory of Open Access Journals (Sweden)

Fabio Caetano Oliveira Leme

2011-04-01

Full Text Available INTRODUCTION: Fungal infections in human skin, such as sporotrichosis, can occur after fish induced trauma. This work aimed to identify fungi in freshwater fish that are pathogenic to humans. METHODS: Extraction of dental arches from Serrassalmus maculatus (piranha and Hoplias malabaricus (wolf fish, stings from Pimelodus maculatus (mandis catfish, dorsal fin rays from Plagioscion spp. (corvina and Tilapia spp., for culture in Mycosel agar. Some cultures were submitted to DNA extraction for molecular identification by sequencing ITS-5.8S rDNA. RESULTS: Cultures identified most yeast as Candida spp., while sequencing also permitted the identification of Phoma spp. and Yarrowia lipolytica. CONCLUSIONS: While the search for S. schenckii was negative, the presence of fungus of the genera Phoma and Candida revealed the pathogenic potential of this infection route. The genus Phoma is involved in certain forms of phaeohyphomycosis, a subcutaneous mycosis caused by dematiaceous fungi, with reports of infections in human organs and systems. Traumatizing structures of some freshwater fish present pathogenic fungi and this may be an important infection route that must be considered in some regions of Brazil, since there are a large number of a fisherman in constant contact with traumatogenic fish.

Heavy metals analysis in fishes by the X-ray fluorescence method

International Nuclear Information System (INIS)

Perez Novara, Ana Ma.

1986-04-01

Among the sources of contamination in human beings we find ingestion of heavy metals. As it is common practice to pour industrial wastes in waters where fishes feed, some toxic elements present in water may pass to human beings through ingestion. It is therefore important to determine the concentrations of heavy metals present in fishes, mainly in those living in waters close to industrial zones or villages. Concentrations of heavy metals in tissue of fishes amount to ppm, hence making necessary the use of very sensitive analytical techniques which do not require a too complex preparation of the sample in order to avoid the loss or contamination of interesting elements of analysis while handling them, thus falsifying the results. The X-Ray Fluorescence method covers these requirements and is not destructive nor multi-elemental. The development of the technique of element analysis in fishes by X-Ray Fluorescence comprised several aspects. from sampling and storage to quantification, specially stressing the preparation of samples. The work was carried out with a Si-Li detector/monitor for solid state and associated electronic equipment. Cd-109 and Pu-238 sources were used to produce excitation, detection limits near 1 ppm were obtained in the majority of elements the technique attained for the analysis of this kind of samples fulfills the celerity, precision, accuracy, and sensitivity requirements. (author)

Numerical Analysis of Aerodynamic Characteristics of the Finned Surfaces with Cross-inclined Fins

Directory of Open Access Journals (Sweden)

Lagutin A. E.

2016-12-01

Full Text Available This paper presents results of numerical research and analyses air-side hydraulic performance of tube bundles with cross inclined fins. The numerical simulation of the fin-tube heat exchanger was performed using the Comsol Femlab software. The results of modeling show the influence of fin inclination angle and tube pitch on hydraulic characteristics of finned surfaces. A series of numerical tests were carried out for tube bundles with different inclination angles (γ =900, 850, 650, 60, the fin pitch u=4 mm. The results indicate that tube bundles with cross inclined fins can significantly enhance the average integral value of the air flow rate in channel between fins in comparison with conventional straight fins. Aerodynamic processes on both sides of modificated channel between inclined fins were analyzed. The verification procedures for received results of numerical modeling with experimental data were performed.

Frost behavior of a fin surface with temperature variation along heat exchanger fins

International Nuclear Information System (INIS)

Kim, Jung Soo; Kim, Min Soo; Lee, Kwan Soo; Kim, Ook Joong

2007-01-01

This paper presents a mathematical model for predicting the frost behavior formed on heat exchanger fins, considering fin heat conduction under frosting condition. The model is composed of air-side, the frost layer, and fin region, and they are coupled to the frost layer. The frost behavior is more accurately predicted with fin heat conduction considered (Case A) than with a constant fin surface temperature assumed (Case B). The results indicate that the frost thickness and heat transfer rate for Case B are over-predicted in most regions of the fin, as compared to those for Case A. Also, for Case A, the maximum frost thickness varies little with the fin length variations, and the extension of the fin length over 30 mm contributes insignificantly to heat transfer

An IPMC-enabled bio-inspired bending/twisting fin for underwater applications

Science.gov (United States)

Palmre, Viljar; Hubbard, Joel J.; Fleming, Maxwell; Pugal, David; Kim, Sungjun; Kim, Kwang J.; Leang, Kam K.

2013-01-01

This paper discusses the design, fabrication, and characterization of an ionic polymer-metal composite (IPMC) actuator-based bio-inspired active fin capable of bending and twisting motion. It is pointed out that IPMC strip actuators are used in the simple cantilever configuration to create simple bending (flapping-like) motion for propulsion in underwater autonomous systems. However, the resulting motion is a simple 1D bending and performance is rather limited. To enable more complex deformation, such as the flapping (pitch and heaving) motion of real pectoral and caudal fish fins, a new approach which involves molding or integrating IPMC actuators into a soft boot material to create an active control surface (called a ‘fin’) is presented. The fin can be used to realize complex deformation depending on the orientation and placement of the actuators. In contrast to previously created IPMCs with patterned electrodes for the same purpose, the proposed design avoids (1) the more expensive process of electroless plating platinum all throughout the surface of the actuator and (2) the need for specially patterning the electrodes. Therefore, standard shaped IPMC actuators such as those with rectangular dimensions with varying thicknesses can be used. One unique advantage of the proposed structural design is that custom shaped fins and control surfaces can be easily created without special materials processing. The molding process is cost effective and does not require functionalizing or ‘activating’ the boot material similar to creating IPMCs. For a prototype fin (90 mm wide × 60 mm long × 1.5 mm thick), the measured maximum tip displacement was approximately 44 mm and the twist angle of the fin exceeded 10°. Lift and drag measurements in water where the prototype fin with an airfoil profile was dragged through water at a velocity of 21 cm s-1 showed that the lift and drag forces can be affected by controlling the IPMCs embedded into the fin structure. These

CADMIUM, LEAD AND MERCURY CONTENTS IN FISHES – CASE STUDY

Directory of Open Access Journals (Sweden)

Radovan Stanovič

2012-02-01

Full Text Available Fish meat is a perfect foodstuff which is up to standard of rational nourishment. It is source of healthy and good digestible material rich on proteins, minerals and vitamins. Fish muscles especially back and lateral muscles are the most important parts of fish organism consumed for escellent chemical composition. Proteins in fish meat are rich on high aminoacids content. The content of fish fat is usually low with the high proportion of unsaturated fatty acids. Also minerals and B, A and D vitamins are very important components of this foodstuff. According to rational nourishment the fish meat should be consumed minimal 2 times weekly. Our research was focused on analysis of bottomn sediments in water reservoir Kolinany from the aspect of Cd, Hg and Pb contents, the determination of observed heavy metal contents in different parts of carp body and the evaluation of hygienic status and suitability of fish meat for the human consumption. Our results have confirmed the hygienic wholesomeness of bottom sediments in water reservoir Kolinany. The Cd, Pb and Hg contents in sediments represent no risk of their input into the fish organisms. The Cd content in fish meat was lower than maximal available amount given by legislative norms, but in selected parts of fish organism such as skin, gills and fins the Cd hygienic limit is 2.9 – 6.6 times exceeded. The Pb content in fish meat was under the hygienic limit, however in skin, gills and fins the content of this heavy metal was 1.31- 2.64 higher than maximal legislative given value. Fish skin, gills and fins belong to the non cosumed parts of fish body by people. The Hg content in fish meat was also lower than hygienc limit. The highest Hg content was observed in fish muscles (0.0544 mg.kg-1 and the lowest one in fish gonads (0.0058 mg.kg-1. The results of Cd, Pb and Hg content determination in carp body confirmed that fish muscles belong to suitable foodstuffs for the human consumption.

NODC Standard Format Pathology Data Sets (1973-1975): Fin Rot (F006) Data (NODC Accession 0014147)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Fin Rot (F006) dataset contains data from examinations of the biological condition of diseased fishes. For tow samples collected, data include: total number of...

A digest of bony fish tapeworms

Czech Academy of Sciences Publication Activity Database

Scholz, Tomáš; Kuchta, Roman

2017-01-01

Roč. 67, č. 2 (2017), s. 43-58 ISSN 0240-8759 R&D Projects: GA ČR(CZ) GBP505/12/G112 Institutional support: RVO:60077344 Keywords : Cestoda * review * diversity * host associations * distributions * phylogeny * Actinopterygii * biogeography Subject RIV: EG - Zoology OBOR OECD: Zoology Impact factor: 0.343, year: 2016

An Upper Paleocene Antigonia-like fish from Denmark

DEFF Research Database (Denmark)

Bonde, Niels Christensøn

1997-01-01

), but highly derived fishes, toothless with strong body armour and some strong fin spines. The phylogenetic analyses of these fishes indicate that much convergent evolution and a number of reversals must have occurred, both in this very advanced group of "higher" teleosteans and within the acanthopts...

Methylmercury in dried shark fins and shark fin soup from American restaurants.

Science.gov (United States)

Nalluri, Deepthi; Baumann, Zofia; Abercrombie, Debra L; Chapman, Demian D; Hammerschmidt, Chad R; Fisher, Nicholas S

2014-10-15

Consumption of meat from large predatory sharks exposes human consumers to high levels of toxic monomethylmercury (MMHg). There also have been claims that shark fins, and hence the Asian delicacy shark fin soup, contain harmful levels of neurotoxic chemicals in combination with MMHg, although concentrations of MMHg in shark fins are unknown. We measured MMHg in dried, unprocessed fins (n=50) of 13 shark species that occur in the international trade of dried shark fins as well as 50 samples of shark fin soup prepared by restaurants from around the United States. Concentrations of MMHg in fins ranged from 9 to 1720 ng/g dry wt. MMHg in shark fin soup ranged from sharks such as hammerheads (Sphyrna spp.). Consumption of a 240 mL bowl of shark fin soup containing the average concentration of MMHg (4.6 ng/mL) would result in a dose of 1.1 μg MMHg, which is 16% of the U.S. EPA's reference dose (0.1 μg MMHg per 1 kg per day in adults) of 7.4 μg per day for a 74 kg person. If consumed, the soup containing the highest measured MMHg concentration would exceed the reference dose by 17%. While shark fin soup represents a potentially important source of MMHg to human consumers, other seafood products, particularly the flesh of apex marine predators, contain much higher MMHg concentrations and can result in substantially greater exposures of this contaminant for people. Copyright © 2014 Elsevier B.V. All rights reserved.

Sustained periodic terrestrial locomotion in air-breathing fishes.

Science.gov (United States)

Pace, C M; Gibb, A C

2014-03-01

While emergent behaviours have long been reported for air-breathing osteichthyians, only recently have researchers undertaken quantitative analyses of terrestrial locomotion. This review summarizes studies of sustained periodic terrestrial movements by air-breathing fishes and quantifies the contributions of the paired appendages and the axial body to forward propulsion. Elongate fishes with axial-based locomotion, e.g. the ropefish Erpetoichthys calabaricus, generate an anterior-to-posterior wave of undulation that travels down the axial musculoskeletal system and pushes the body against the substratum at multiple points. In contrast, appendage-based locomotors, e.g. the barred mudskipper Periophthalmus argentilineatus, produce no axial bending during sustained locomotion, but instead use repeated protraction-retraction cycles of the pectoral fins to elevate the centre of mass and propel the entire body anteriorly. Fishes that use an axial-appendage-based mechanism, e.g. walking catfishes Clarias spp., produce side-to-side, whole-body bending in co-ordination with protraction-retraction cycles of the pectoral fins. Once the body is maximally bent to one side, the tail is pressed against the substratum and drawn back through the mid-sagittal plane, which elevates the centre of mass and rotates it about a fulcrum formed by the pectoral fin and the ground. Although appendage-based terrestrial locomotion appears to be rare in osteichthyians, many different species appear to have converged upon functionally similar axial-based and axial-appendage-based movements. Based on common forms observed across divergent taxa, it appears that dorsoventral compression of the body, elongation of the axial skeleton or the presence of robust pectoral fins can facilitate effective terrestrial movement by air-breathing fishes. © 2014 The Fisheries Society of the British Isles.

50 CFR 600.1204 - Shark finning; possession at sea and landing of shark fins.

Science.gov (United States)

2010-10-01

... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Shark finning; possession at sea and landing of shark fins. 600.1204 Section 600.1204 Wildlife and Fisheries FISHERY CONSERVATION AND... PROVISIONS Shark Finning § 600.1204 Shark finning; possession at sea and landing of shark fins. (a)(1) No...

Fin Type Variation of Lionhead Strain Goldfish (Carassius auratus Offspring

Directory of Open Access Journals (Sweden)

M. Syaifudin

2007-12-01

Full Text Available  Lionhead strain goldfish (Carassius auratus inheritance produce many variations in phenotype qualitative traits of their offspring that is not common with the parents. Lionhead is an ornamental freshwater fish, they do not have a dorsal fin, but it is a beauty finfish, is popular to the people and have a high economic value. Of the 846 offspring of lionhead is produced in this experiment, and 57,7% of them have dorsal fin (42,3% normal, 13,1% of them have anal fin which did not similar with their parents, 58,6% caudal fin of them did not have similar to their parents. It might be caused by incompletely segregation in meiosis and many gen responsible to certain phenotype trait. Another abnormalities such as no anal fin, blindness, stumped and no pigmen in their gill lamella also occurred. Key words: Inheritance, fin, phenotype, abnormality   ABSTRAK Ikan maskoki strain lionhead menghasilkan keturunan dengan fenotip yang sangat bervariasi dan berbeda dengan induknya. Ikan ini merupakan ikan hias air tawar yang tidak memiliki sirip punggung namun tetap memiliki keindahan, sehingga menjadi begitu populer di masyarakat dan memiliki nilai ekonomi yang tinggi. Sebanyak 846 keturunan (anakan telah dihasilkan dalam percobaan ini, dan sebanyak 57,7% dari populasi tersebut memiliki sirip punggung (berarti 42,3% merupakan keturunan normal, 13,1% memiliki sirip dubur yang tidak mirip dengan induknya. Variasi keturunan ikan maskoki strain lionhead ini disebabkan oleh segregasi yang tidak sempurna dalam proses meiosis dan banyaknya gen yang terlibat dalam pembentukan penotip tertentu. Abnormalitas lainnya juga terjadi pada keturunan ikan maskoki strain lionhead ini, seperti tidak adanya sirip dubur, mata buta, tubuh pendek dan tidak adanya pigmen pada lemela insang Kata kunci: Keturunan, sirip, fenotip, abnormalitas  

Morphological observation and length-weight relationship of critically endangered riverine catfish Rita rita (Hamilton).

Science.gov (United States)

Amin, M R; Mollah, M F A; Taslima, K; Muhammadullah

2014-01-15

The experiment was conducted to investigate the morphological status of the critically endangered riverine catfish Rita rita using morphometric and meristic traits. About 158 species of Rita were collected from the old Brahmaputra river in Mymensingh district and were studied in the laboratory of the Fisheries Biology and Genetics Department, Bangladesh Agricultural University. Measurement of length and weight of Rita were recorded by using measuring scale and electric balance respectively. Significant curvilinear relationship existed between total length and other morphometric characters and between head length and other characters of the head. Relationships between total length and various body measurements of the fish were highly significant (p < 0.01) except the relationship between total length and pelvic fin length of male fish (p < 0.05). In case of meristic characters-dorsal fin rays, pelvic fin rays, pectoral fin rays, anal fin rays, caudal fin rays, number of vertebrae and branchiostegal rays were found to be more or less similar except slight differences. The values of condition factors (k) in the total length body-weight relationships for female and male were found to be 0.41 and 0.38, respectively. The mean values of relative condition factors (kn) were 1.0 and 1.005 for female and male, respectively.

Fungal Infections in Some Economically Important Freshwater Fishes

Directory of Open Access Journals (Sweden)

Zafar Iqbal*, Uzma Sheikh and Rabia Mughal

2012-06-01

Full Text Available Aim of this study was to investigate fungal infections in four species of carps including goldfish, Carassius (C. auratus L.; silver carp, Hypophthalmichthys (H. molitrix Richardsons; rahu, Labeo (L. rohita Hamilton and Ctenopharyngodon (C. idella Valenciennes. Nine specimens of each species were studied for the presence of fungal infections. Infected fishes showed clinical signs such as fungal growth on skin, fins, eyes, eroded fins and scales, hemorrhages on body surface and abdominal distension. The specimens from infected organs of fish were inoculated on each, malt extract, Sabouraud dextrose and potato dextrose agars. The fungal colonies of white, black, green, grey and brown colors were observed in the agar plates. Slides were prepared and stained with 0.05% Trypan blue in lactophenol. C. auratus showed the highest infection rate (44.4% followed by H. molitrix and L. rohita (11.1% each. Five fungal species viz. Aspergillus (33.3%, Penicillium (22.2%, Alternaria (27.7%, Blastomyces spp (11.1% and Rhizopus (5.5% were isolated. Posterior part of the fish had significantly (P=0.05 higher (62.5% infection as compared to anterior part (37.5%. The caudal fin with 31.25% infection was the single most affected area. This study showed that most of the fungi isolated from fishes are considered as normal mycoflora, yet many fungi can cause natural infections in ponds and aquarium.

Hydrodynamics of vertical jumping in Archer fish

Science.gov (United States)

Techet, Alexandra H.; Mendelson, Leah

2017-11-01

Vertical jumping for aerial prey from an aquatic environment requires both propulsive power and precise aim to succeed. Rapid acceleration to a ballistic velocity sufficient for reaching the prey height occurs before the fish leaves the water completely and experiences a thousandfold drop in force-producing ability. In addition to speed, accuracy and stability are crucial for successful feeding by jumping. This talk examines the physics of jumping using the archer fish as a model. Better known for their spitting abilities, archer fish will jump multiple body lengths out of the water for prey capture, from a stationary position just below the free surface. Modulation of oscillatory body kinematics and use of multiple fins for force production are identified as methods through which the fish can meet requirements for both acceleration and stabilization in limited space. Quantitative 3D PIV wake measurements reveal how variations in tail kinematics relate to thrust production throughout the course of a jumping maneuver and over a range of jump heights. By performing measurements in 3D, the timing, interactions, and relative contributions to thrust and lateral forces from each fin can be evaluated, elucidating the complex hydrodynamics that enable archer fish water exit.

A noninvasive monitoring device for anesthetics in fish

DEFF Research Database (Denmark)

Power, Deborah M.; Fuentes, Juan; Harrison, Adrian Paul

2010-01-01

A noninvasive device capable of recording both gill and lateral fin movements was assembled and used to analyze initial and post-treatment activity frequency (Hz) in fish exposed to anesthetics. Exposure of platy fish (Xiphosphorus maculatus) to saponins from quillaja bark (0.185 mM and 0.555 m...

85 million years of pelagic ecosystem evolution: Pacific Ocean deep-sea ichthyolith records reveal fish community dynamics and a long-term decline in sharks

Science.gov (United States)

Sibert, E. C.; Norris, R. D.; Cuevas, J. M.; Graves, L. G.

2015-12-01

The structure and productivity of open ocean consumers has undergone major changes over the past 85 million years. Here, we present the first long-term detailed records of pelagic fish and sharks utilizing the record of ichthyoliths (teeth and dermal scales) from the deep Pacific Ocean. While the North and South Pacific Oceans show similar patterns throughout the 85 million year history, the North Pacific ichthyolith accumulation is significantly higher than the South Pacific, suggesting that the basin has been a more productive region for tens of millions of years. Fish and sharks were not abundant in the Pacific gyres until ~75 million years ago (Ma) suggesting that neither group was quantitatively important in oligotrophic pelagic food webs prior to the latest Cretaceous. Relative to ray-finned fish, sharks were common in the ancient ocean. Most ichthyolith assemblages have >50% shark dermal scales (denticles), but denticle abundance has been declining in both absolute and relative abundance since the Cretaceous-Paleogene (K/Pg) mass extinction. The accumulation rate of ichthyoliths of both sharks and ray-finned fish was highest in the Early Eocene, during the peak of the Cenozoic 'greenhouse' climate where production of shark dermal denticles and fish teeth increased almost five times over Paleocene production rates. Ichthyolith fluxes fell with cooler climates in the later Eocene and Oligocene, but fish production is almost always higher than in the Cretaceous and Paleocene reflecting the expanded ecological roles and importance of pelagic fish in marine ecosystems. Shark denticle production fell to less than half that of the Cretaceous by 20 Ma when it dropped abruptly to near-zero levels. Currently denticles make up sharks appear to be falling as major pelagic consumers over the Late Cretaceous and Cenozoic, and particularly over the past 20 Ma, perhaps reflecting demographic changes in shark and fish communities, or the rise of resource competition from

Taphonomy of Early Triassic fish fossils of the Vega-Phroso Siltstone Member of the Sulphur Mountain Formation near Wapiti Lake, British Columbia, Canada

Directory of Open Access Journals (Sweden)

Karen Anderson

2013-10-01

Full Text Available The taphonomy of fishes living in lacustrine environments has been extensively studied in both the laboratory and the fossil record; the taphonomy of marine fishes, however, is poorly known. Triassic marine fishes with heavy ganoid and cosmoid scales, which provided protection from rapid taphonomic loss, offer a means to examine marine fish taphonomy in the fossil record. Four genera of Early Triassic fishes (the ray-finned actinopterygians Albertonia, Bobasatrania, Boreosomus, and the lobe-finned coelacanth (sarcopterygian, Whiteia from the Wapiti Lake, British Columbia locality of the Lower Triassic Sulphur Mountain Formation were examined in order to gain a better understanding of the taphonomy of fish in marine environments, determine ambient environmental conditions in the region during the Early Triassic, and ascertain the habitat and mode of life of the fish. Results indicate that environmental conditions that contributed to the preservation of the fossil fishes of the current study included deposition in deep, quiet waters, which reduced the odds of disarticulation, colder waters under higher pressure, which slowed decay and limited postmortem floatation, and waters that were anoxic, which discouraged predators and scavengers. In addition, the thickness of the primitive ganoid and cosmoid scales of the fossil fishes also increased their preservation potential. Taphonomic, physiological and environmental indicators suggest that Whiteia, Albertonia, and possibly Bobasatrania lived in deep, cold waters near the oxygen minimum zone, while Boreosomus lived higher in the water column. While the anatomical and physiological characteristics of modern fishes will likely continue to inhibit marine taphonomy studies, examination of ancient fish, particularly those with ganoid or cosmoid scales, may provide future avenues of research to gain a better understanding of marine fish taphonomy and provide a powerful tool to examine ancient fish behavior

Experimental hydrodynamics of swimming in fishes

Science.gov (United States)

Tytell, Eric Daniel

2005-11-01

The great diversity of fish body shapes suggests that they have adapted to different selective pressures. For many fishes, the pressures include hydrodynamic demands: swimming efficiently or accelerating rapidly, for instance. However, the hydrodynamic advantages or disadvantages to specific morphologies are poorly understood. In particular, eels have been considered inefficient swimmers, but they migrate long distances without feeding, a task that requires efficient swimming. This dissertation, therefore, begins with an examination of the swimming hydrodynamics of American eels, Anguilla rostrata, at steady swimming speeds from 0.5 to 2 body lengths (L) per second and during accelerations from -1.4 to 1.3 L s -2. The final chapter examines the hydrodynamic effects of body shape directly by describing three-dimensional flow around swimming bluegill sunfish, Lepomis macrochirus. In all chapters, flow is quantified using digital particle image velocimetry, and simultaneous kinematics are measured from high-resolution digital video. The wake behind a swimming eel in the horizontal midline plane is described first. Rather than producing a wake with fluid jets angled backwards, like in fishes such as sunfish, eels have a wake with exclusively lateral jets. The lack of downstream momentum indicates that eels balance the axial forces of thrust and drag evenly over time and over their bodies, and therefore do not change axial fluid momentum. This even balance, present at all steady swimming speeds, is probably due to the relatively uniform body shape of eels. As eels accelerate, thrust exceeds drag, axial momentum increases, and the wake approaches that of other fishes. During steady swimming, though, the lack of axial momentum prevents direct efficiency estimation. The effect of body shape was examined directly by measuring flow in multiple transverse planes along the body of bluegill sunfish swimming at 1.2 L s-1. The dorsal and anal fin, neglected in many previous

Oscillatory Adaptive Yaw-Plane Control of Biorobotic Autonomous Underwater Vehicles Using Pectoral-Like Fins

Directory of Open Access Journals (Sweden)

Mugdha S. Naik

2007-01-01

Full Text Available This article considers the control of a biorobotic autonomous underwater vehicle (BAUV in the yaw plane using biologically inspired oscillatory pectoral-like fins of marine animals. The fins are assumed to be oscillating harmonically with a combined linear (sway and angular (yaw motion producing unsteady forces, which are used for fish-like control of BAUVs. Manoeuvring of the BAUV in the yaw plane is accomplished by altering the bias (mean angle of the angular motion of the fin. For the derivation of the adaptive control system, it is assumed that the physical parameters, the hydrodynamic coefficients, and the fin force and moment are not known. A direct adaptive sampled-data control system for the trajectory control of the yaw-angle using only yaw-angle measurement is derived. The parameter adaptation law is based on the normalised gradient scheme. Simulation results for the set point control, sinusoidal trajectory tracking and turning manoeuvres are presented, which show that the control system accomplishes precise trajectory control in spite of the parameter uncertainties.

An IPMC-enabled bio-inspired bending/twisting fin for underwater applications

International Nuclear Information System (INIS)

Palmre, Viljar; Pugal, David; Kim, Sungjun; Kim, Kwang J; Hubbard, Joel J; Fleming, Maxwell; Leang, Kam K

2013-01-01

This paper discusses the design, fabrication, and characterization of an ionic polymer–metal composite (IPMC) actuator-based bio-inspired active fin capable of bending and twisting motion. It is pointed out that IPMC strip actuators are used in the simple cantilever configuration to create simple bending (flapping-like) motion for propulsion in underwater autonomous systems. However, the resulting motion is a simple 1D bending and performance is rather limited. To enable more complex deformation, such as the flapping (pitch and heaving) motion of real pectoral and caudal fish fins, a new approach which involves molding or integrating IPMC actuators into a soft boot material to create an active control surface (called a ‘fin’) is presented. The fin can be used to realize complex deformation depending on the orientation and placement of the actuators. In contrast to previously created IPMCs with patterned electrodes for the same purpose, the proposed design avoids (1) the more expensive process of electroless plating platinum all throughout the surface of the actuator and (2) the need for specially patterning the electrodes. Therefore, standard shaped IPMC actuators such as those with rectangular dimensions with varying thicknesses can be used. One unique advantage of the proposed structural design is that custom shaped fins and control surfaces can be easily created without special materials processing. The molding process is cost effective and does not require functionalizing or ‘activating’ the boot material similar to creating IPMCs. For a prototype fin (90 mm wide × 60 mm long × 1.5 mm thick), the measured maximum tip displacement was approximately 44 mm and the twist angle of the fin exceeded 10°. Lift and drag measurements in water where the prototype fin with an airfoil profile was dragged through water at a velocity of 21 cm s −1 showed that the lift and drag forces can be affected by controlling the IPMCs embedded into the fin structure

Effects of ultra-thin Si-fin body widths upon SOI PMOS FinFETs

Science.gov (United States)

Liaw, Yue-Gie; Chen, Chii-Wen; Liao, Wen-Shiang; Wang, Mu-Chun; Zou, Xuecheng

2018-05-01

Nano-node tri-gate FinFET devices have been developed after integrating a 14 Å nitrided gate oxide upon the silicon-on-insulator (SOI) wafers established on an advanced CMOS logic platform. These vertical double gate (FinFET) devices with ultra-thin silicon fin (Si-fin) widths ranging from 27 nm to 17 nm and gate length down to 30 nm have been successfully developed with a 193 nm scanner lithography tool. Combining the cobalt fully silicidation and the CESL strain technology beneficial for PMOS FinFETs was incorporated into this work. Detailed analyses of Id-Vg characteristics, threshold voltage (Vt), and drain-induced barrier lowering (DIBL) illustrate that the thinnest 17 nm Si-fin width FinFET exhibits the best gate controllability due to its better suppression of short channel effect (SCE). However, higher source/drain resistance (RSD), channel mobility degradation due to dry etch steps, or “current crowding effect” will slightly limit its transconductance (Gm) and drive current.

The GC-heterogeneity of teleost fishes

Directory of Open Access Journals (Sweden)

Gautier Christian

2008-12-01

Full Text Available Abstract Background One of the most striking features of mammalian and birds chromosomes is the variation in the guanine-cytosine (GC content that occurs over scales of hundreds of kilobases to megabases; this is known as the "isochore" structure. Among other vertebrates the presence of isochores depends upon the taxon; isochore are clearly present in Crocodiles and turtles but fish genome seems very homogeneous on GC content. This has suggested a unique isochore origin after the divergence between Sarcopterygii and Actinopterygii, but before that between Sauropsida and mammals. However during more than 30 years of analysis, isochore characteristics have been studied and many important biological properties have been associated with the isochore structure of human genomes. For instance, the genes are more compact and their density is highest in GC rich isochores. Results This paper shows in teleost fish genomes the existence of "GC segmentation" sharing some of the characteristics of isochores although teleost fish genomes presenting a particular homogeneity in CG content. The entire genomes of T nigroviridis and D rerio are now available, and this has made it possible to check whether a mosaic structure associated with isochore properties can be found in these fishes. In this study, hidden Markov models were trained on fish genes (T nigroviridis and D rerio which were classified by using the isochore class of their human orthologous. A clear segmentation of these genomes was detected. Conclusion The GC content is an excellent indicator of isochores in heterogeneous genomes as mammals. The segmentation we obtained were well correlated with GC content and other properties associated to GC content such as gene density, the number of exons per gene and the length of introns. Therefore, the GC content is the main property that allows the detection of isochore but more biological properties have to be taken into account. This method allows detecting

FinTech in Norway : the effect of FinTech on the traditional Norwegian banking sector

OpenAIRE

Omreng, Stian; Gjendem, Ida

2017-01-01

The purpose of this thesis is to investigate the effect of FinTech on the Norwegian banking industry. We investigate the drivers of FinTech, the current and potential Norwegian FinTech market, and the international competitiveness of the Norwegian FinTech movement. We identify nine segments of FinTech within the traditional banking functions Financing, Asset management, Payments and Authentication, and we find the key drivers behind the rapid growth of the FinTech market as cha...

Performance study of a fin and tube heat exchanger with different fin geometry

DEFF Research Database (Denmark)

Singh, Shobhana; Sørensen, Kim; Condra, Thomas Joseph

2016-01-01

This study analyses the effect of different fin geometries on the heat transfer and pressure loss characteristics of a fin and tube heat exchanger. A numerical investigation is carried out on liquid–gas type double-finned tube heat exchanger under cross-flow condition. Three different cross......-sections namely: a) Rectangular, b) Trapezoidal, c) Triangular are adopted to define the fin geometry. The CFD simulations are performed to incorporate coupled steady state conjugate heat transfer with the turbulent flow phenomenon for the Reynolds number in the range of 5000-13000. Dimensionless heat transfer...... models show that triangular fin geometry can provide higher heat transfer performance in comparison to the fins with rectangular and trapezoidal geometry with lower pressure loss and a bonus of 7.27% reduction in weight under similar operating conditions....

Relação preliminar das espécies de peixes (Pisces, Elasmobranchii, Actinopterygii ameaçadas no Brasil Preliminary list of endangered fish species (Pisces, Elasmobranchii , Actinopterygii in Brazil

Directory of Open Access Journals (Sweden)

Ricardo S Rosa

1996-01-01

Full Text Available The Brazilian fish fauna is still poorly known with respect to its diversity and conservation status, particularly of freshwater species. Human activities and population growth are rapidly impacting this fauna to an unchecked extent, so that many fish species are presently threatened. Also, some areas have been so critically altered that their fish fauna can no longer be properly inventoried. There is an urgent need to evaluate the conservation status of Brazilian fish species, since none are presently listed as endangered by federal legislation. Based on a literature search and a survey directed to the Neotropical ichthyologists, we present an unofficial list including a total of 78 threatened fish species (12 elasmobranchs and 66 actinopterygians. Of these, sixteen actinopterygian species are listed as endangered, three elasmobranchs and nine actinopterygians as vulnerable, and seven actinopterygians as rare; 40 species either have indeterminate status or are data deficient to yield an adequate assessment, and three species are listed as extinct or possibly extinct.

Flow and Mass Transfer Performance in Short Pin-Fin Channels with Different Fin Shapes

OpenAIRE

Goldstein, R. J.; Chen, S. B.

1998-01-01

The mass transfer (analogous to heat transfer) and pressure loss characteristics of staggered short pin-fin arrays are investigated experimentally in the range of Reynolds number 3000 to 18,000 based on fin diameter and mean approach-flow velocity. Three different shapes of fins with aspect ratio of 2 are examined: one uniform-diameter circular fin (UDCF) and two stepped-diameter circular fins (SDCF1 and SDCF2). Flow visualization using oil-lampblack reveals complex flow characteristics assoc...

Population trends in Pacific Oceanic sharks and the utility of regulations on shark finning.

Science.gov (United States)

Clarke, Shelley C; Harley, Shelton J; Hoyle, Simon D; Rice, Joel S

2013-02-01

Accurate assessment of shark population status is essential for conservation but is often constrained by limited and unreliable data. To provide a basis for improved management of shark resources, we analyzed a long-term record of species-specific catches, sizes, and sexes of sharks collected by onboard observers in the western and central Pacific Ocean from 1995 to 2010. Using generalized linear models, we estimated population-status indicators on the basis of catch rate and biological indicators of fishing pressure on the basis of median size to identify trends for blue (Prionace glauca), mako (Isurus spp.), oceanic whitetip (Carcharhinus longimanus), and silky (Carcharhinus falciformis) sharks. Standardized catch rates of longline fleets declined significantly for blue sharks in the North Pacific (by 5% per year [CI 2% to 8%]), for mako sharks in the North Pacific (by 7% per year [CI 3% to 11%]), and for oceanic whitetip sharks in tropical waters (by 17% per year [CI 14% to 20%]). Median lengths of silky and oceanic whitetip sharks decreased significantly in their core habitat, and almost all sampled silky sharks were immature. Our results are consistent with results of analyses of similar data sets. Combined, these results and evidence of targeted fishing for sharks in some regional fisheries heighten concerns for sustainable utilization, particularly for oceanic whitetip and North Pacific blue sharks. Regional regulations that prohibit shark finning (removal of fins and discarding of the carcass) were enacted in 2007 and are in many cases the only form of control on shark catches. However, there is little evidence of a reduction of finning in longline fisheries. In addition, silky and oceanic whitetip sharks are more frequently retained than finned, which suggests that even full implementation of and adherence to a finning prohibition may not substantially reduce mortality rates for these species. We argue that finning prohibitions divert attention from

Polonium-210 in dried fin fishes of Tuticorin, Southeast coast of India

International Nuclear Information System (INIS)

Carol, R.; Wesley, S.G.

2013-01-01

Tuticorin is one of the major sea-ports and fish-landing centres in the southeastern coast of India. Most of the fishes landed in this coast are consumed fresh and 40% of the fishes are used in the dried form. 210 Po (t 1/2 = 138.4 days) in marine food has received much interest from the scientific community because of its high toxicity and the radioactive dose it delivers to marine organisms and human beings when compared to anthropogenic radionuclides released into coastal waters. Although many studies have been conducted in fresh fishes from various coasts concerning 210 Po, sufficient data are not available for value-added dried marine fish products. In the present study, 210 Po and 210 Pb were quantified in some commercially important dried fishes and their exposure to humans studied. Polonium-210 was determined after wet digestion and counted using an alpha probe. Overall, the concentration of 210 Po in the dried fish muscle tissue ranged from 1.45 ± 0.82 to 559.23 ± 5.45 Bq kg -1 . The highest concentration in the muscle tissue was recorded for the species Stolephorus brevisensis (559.23 ± 8.9 Bq kg -1 ) belonging to the group Clupeidae and the lowest in Harpodon sp. (Bombay duck). The 210 Po dose receive by the public due to consumption of the dried fishes was found to be in the range of 25.2-350.3 μSV yr -1 and the fish samples were found to be radiologically safe. (author)

The covert world of fish biofluorescence: a phylogenetically widespread and phenotypically variable phenomenon.

Directory of Open Access Journals (Sweden)

John S Sparks

Full Text Available The discovery of fluorescent proteins has revolutionized experimental biology. Whereas the majority of fluorescent proteins have been identified from cnidarians, recently several fluorescent proteins have been isolated across the animal tree of life. Here we show that biofluorescence is not only phylogenetically widespread, but is also phenotypically variable across both cartilaginous and bony fishes, highlighting its evolutionary history and the possibility for discovery of numerous novel fluorescent proteins. Fish biofluorescence is especially common and morphologically variable in cryptically patterned coral-reef lineages. We identified 16 orders, 50 families, 105 genera, and more than 180 species of biofluorescent fishes. We have also reconstructed our current understanding of the phylogenetic distribution of biofluorescence for ray-finned fishes. The presence of yellow long-pass intraocular filters in many biofluorescent fish lineages and the substantive color vision capabilities of coral-reef fishes suggest that they are capable of detecting fluoresced light. We present species-specific emission patterns among closely related species, indicating that biofluorescence potentially functions in intraspecific communication and evidence that fluorescence can be used for camouflage. This research provides insight into the distribution, evolution, and phenotypic variability of biofluorescence in marine lineages and examines the role this variation may play.

Ionic polymer-metal composite enabled robotic manta ray

Science.gov (United States)

Chen, Zheng; Um, Tae I.; Bart-Smith, Hilary

2011-04-01

The manta ray, Manta birostris, demonstrates excellent swimming capabilities; generating highly efficient thrust via flapping of dorsally flattened pectoral fins. In this paper, we present an underwater robot that mimics the swimming behavior of the manta ray. An assembly-based fabrication method is developed to create the artificial pectoral fins, which are capable of generating oscillatory with a large twisting angle between leading and trailing edges. Ionic polymer-metal composite (IPMC) actuators are used as artificial muscles in the fin. Each fin consists of four IPMC beams bonded with a compliant poly(dimethylsiloxane) (PDMS) membrane. By controlling each individual IPMC strips, we are able to generate complex flapping motions. The fin is characterized in terms of tip deflection, tip blocking force, twist angle, and power consumption. Based on the characteristics of the artificial pectoral fin, a small size and free-swimming robotic manta ray is developed. The robot consists of two artificial pectoral fins, a rigid body, and an on-board control unit with a lithium ion rechargeable battery. Experimental results show that the robot swam at a speed of up to 0.055 body length per second (BL/sec).

Novel 14-nm Scallop-Shaped FinFETs (S-FinFETs) on Bulk-Si Substrate

OpenAIRE

Xu, Weijia; Yin, Huaxiang; Ma, Xiaolong; Hong, Peizhen; Xu, Miao; Meng, Lingkuan

2015-01-01

In this study, novel p-type scallop-shaped fin field-effect transistors (S-FinFETs) are fabricated using an all-last high-k/metal gate (HKMG) process on bulk-silicon (Si) substrates for the first time. In combination with the structure advantage of conventional Si nanowires, the proposed S-FinFETs provide better electrostatic integrity in the channels than normal bulk-Si FinFETs or tri-gate devices with rectangular or trapezoidal fins. It is due to formation of quasi-surrounding gate electrod...

Percentage and Intensity in Parasite That Attack Common Carp Fish Cyprinus carpio from Alforat River Breeding Fish Cages Al-Mussayab/Iraq

Directory of Open Access Journals (Sweden)

Hussein Takheal Hussein

2018-05-01

Full Text Available        84 samples of common carp Cyprinus carpio that bird in cages of fishes  birding in AlForat River Al-Mussayab was examined for a period of January until June 2017 .     The fishes was examined for the presence  of Ichthyophthirius multifiliis parasite on the skin, Fins and gills.    The percentage and total mean intensity infection%14.28, 5.6، % 20.23, 6.2,% 27.38 11.5 respectively the monthly changes was Studied and the part of the fish body was chosen according to sex and we recording the highest percentage of infection from April 53.33% and highest intensity in August were the percentage was 21.6%.      There was no recording of differences in chosen of site of infection and also in sex and host either in skin, Fins and gills.

Development of non-lethal monitoring of stable isotopes in asp (Leuciscus aspius): a comparison of muscle, fin and scale tissues

Czech Academy of Sciences Publication Activity Database

Vašek, Mojmír; Vejřík, Lukáš; Vejříková, Ivana; Šmejkal, Marek; Baran, Roman; Muška, Milan; Kubečka, Jan; Peterka, Jiří

2017-01-01

Roč. 785, č. 1 (2017), s. 327-335 ISSN 0018-8158 R&D Projects: GA ČR(CZ) GA15-01625S; GA MŠk(CZ) EE2.3.20.0204 Institutional support: RVO:60077344 Keywords : fish fins * fish scales * fractionation * non-lethal sampling * stable isotopes Subject RIV: EG - Zoology OBOR OECD: Zoology Impact factor: 2.056, year: 2016

Investigation of material efficient fin patterns for cost-effective operation of fin and tube heat exchanger

DEFF Research Database (Denmark)

Singh, Shobhana; Sørensen, Kim; Condra, Thomas Joseph

2017-01-01

Design management of a thermal energy system is a critical part of identifying basic designs that meet large scale user demand under certain operating characteristics. Fin and tube heat exchangers are among the most commonly used thermal energy systems which are generating considerable interest...... and tube heat exchanger. Computational fluid dynamic models of fin and tube heat exchanger with different fin patterns are developed to investigate the fin pattern behavior on heat transfer and pressure loss performance data. In addition, the numerical results are utilized to analyze the engineering design...... scale-up heat exchanger configurations with each fin pattern focusing on the application of chosen fin and tube heat exchanger in marine exhaust gas boiler. The analysis highlights the impact of material efficient fin patterns investigated and predicts that the polynomial and sinusoidal fin patterns...

Differential induction of four msx homeobox genes during fin development and regeneration in zebrafish.

Science.gov (United States)

Akimenko, M A; Johnson, S L; Westerfield, M; Ekker, M

1995-02-01

To study the genetic regulation of growth control and pattern formation during fin development and regeneration, we have analysed the expression of four homeobox genes, msxA, msxB, msxC and msxD in zebrafish fins. The median fin fold, which gives rise to the unpaired fins, expresses these four msx genes during development. Transcripts of the genes are also present in cells of the presumptive pectoral fin buds. The most distal cells, the apical ectodermal ridge of the paired fins and the cleft and flanking cells of the median fin fold express all these msx genes with the exception of msxC. Mesenchymal cells underlying the most distal cells express all four genes. Expression of the msx genes in the fin fold and fin buds is transient and, by 3 days after fertilization, msx expression in the median fin fold falls below levels detectable by in situ hybridization. Although the fins of adult zebrafish normally have levels of msx transcripts undetectable by in situ hybridization, expression of all four genes is strongly reinduced during regeneration of both paired and unpaired fins. Induction of msx gene expression in regenerating caudal fins occurs as early as 30 hours postamputation. As the blastema forms, the levels of expression increase and reach a maximum between the third and fifth days. Then, msx expression progressively declines and disappears by day 12 when the caudal fin has grown back to its normal size. In the regenerating fin, the blastema cells that develop at the tip of each fin ray express msxB and msxC. Cells of the overlying epithelium express msxA and msxD, but do not express msxB or msxC. Amputations at various levels along the proximodistal axis of the fin suggest that msxB expression depends upon the position of the blastema, with cells of the rapidly proliferating proximal blastema expressing higher levels than the cells of the less rapidly proliferating distal blastema. Expression of msxC and msxD is independent of the position of the blastema cell

Body Fineness Ratio as a Predictor of Maximum Prolonged-Swimming Speed in Coral Reef Fishes

Science.gov (United States)

Walker, Jeffrey A.; Alfaro, Michael E.; Noble, Mae M.; Fulton, Christopher J.

2013-01-01

The ability to sustain high swimming speeds is believed to be an important factor affecting resource acquisition in fishes. While we have gained insights into how fin morphology and motion influences swimming performance in coral reef fishes, the role of other traits, such as body shape, remains poorly understood. We explore the ability of two mechanistic models of the causal relationship between body fineness ratio and endurance swimming-performance to predict maximum prolonged-swimming speed (Umax) among 84 fish species from the Great Barrier Reef, Australia. A drag model, based on semi-empirical data on the drag of rigid, submerged bodies of revolution, was applied to species that employ pectoral-fin propulsion with a rigid body at U max. An alternative model, based on the results of computer simulations of optimal shape in self-propelled undulating bodies, was applied to the species that swim by body-caudal-fin propulsion at Umax. For pectoral-fin swimmers, Umax increased with fineness, and the rate of increase decreased with fineness, as predicted by the drag model. While the mechanistic and statistical models of the relationship between fineness and Umax were very similar, the mechanistic (and statistical) model explained only a small fraction of the variance in Umax. For body-caudal-fin swimmers, we found a non-linear relationship between fineness and Umax, which was largely negative over most of the range of fineness. This pattern fails to support either predictions from the computational models or standard functional interpretations of body shape variation in fishes. Our results suggest that the widespread hypothesis that a more optimal fineness increases endurance-swimming performance via reduced drag should be limited to fishes that swim with rigid bodies. PMID:24204575

Studi Analitik dan Numerik Perpindahan Panas pada Fin Trapesium (Studi Kasus pada Finned Tube Heat Exchanger

Directory of Open Access Journals (Sweden)

Ahmad Zaini

2013-09-01

Full Text Available Penambahan fin pada pipa penukar kalor merupakan suatu upaya memperbesar perpindahan kalor konduksi dan konveksi, dengan cara memperluas bidang geometri. Pada penelitian ini dianalisa secara analitik dan numerik perpindahan kalor pada fin dengan profil longitudinal tidak seragam atau berubah terhadap jarak dari dasar fin, dengan memvariasikan ketebalan ujung fin. Hasil dari kedua studi ini tidak jauh berbeda, pada keduanya menjelaskan bahwa fin dengan ketebalan ujung 0,9 mm (fin trapesium terbalik paling baik dari 5 variasi lainnya; serta perubahan temperatur paling besar terjadi pada sepertiga pertama dari panjang  fin, ini artinya pelepasan kalor terbesar terjadi pada daerah tersebut. Perbedaannya adalah pada persentase penurunan temperatur sepanjang  fin terhadap temperatur dasar fin, untuk ketebalan 0,9 mm pada studi analitik sebesar 91,92% dan pada studi numerik sebesar 91,78%. Hal ini berarti metode penyelesaian persamaan diferensial orde 2 dengan koefisien variabel dengan cara pembedahan koefisien variabel pada ODE, sudah benar dan valid. Namun bila ditinjau dari waktu yang diperlukan untuk komputasinya, studi analitik membutuhkan waktu lebih lama. Waktu yang diperlukan dalam komputasinya tergantung dari fungsi koefisien variabel.

The campaign to DNA barcode all fishes, FISH-BOL.

Science.gov (United States)

Ward, R D; Hanner, R; Hebert, P D N

2009-02-01

FISH-BOL, the Fish Barcode of Life campaign, is an international research collaboration that is assembling a standardized reference DNA sequence library for all fishes. Analysis is targeting a 648 base pair region of the mitochondrial cytochrome c oxidase I (COI) gene. More than 5000 species have already been DNA barcoded, with an average of five specimens per species, typically vouchers with authoritative identifications. The barcode sequence from any fish, fillet, fin, egg or larva can be matched against these reference sequences using BOLD; the Barcode of Life Data System (http://www.barcodinglife.org). The benefits of barcoding fishes include facilitating species identification, highlighting cases of range expansion for known species, flagging previously overlooked species and enabling identifications where traditional methods cannot be applied. Results thus far indicate that barcodes separate c. 98 and 93% of already described marine and freshwater fish species, respectively. Several specimens with divergent barcode sequences have been confirmed by integrative taxonomic analysis as new species. Past concerns in relation to the use of fish barcoding for species discrimination are discussed. These include hybridization, recent radiations, regional differentiation in barcode sequences and nuclear copies of the barcode region. However, current results indicate these issues are of little concern for the great majority of specimens.

The Prevalence of Cryptocaryon irritans in wild marine ornamental fish from Vietnam

Science.gov (United States)

Van, K. V.; Nhinh, D. T.

2018-04-01

Wild-caught ornamental marine fish from NhaTrang (Khanh Hoa) and Ha Long (Quang Ninh) in Vietnam were examined over the three sampling batches corresponding to the spring, summer and autumn times for the prevalence of Cryptocaryon irritans. Out of a total of 211 fish (15 species), 143 (67.7 %) were found to be infected with the mean intensity of 7.67 parasites per field of view (x4 magnification). The prevalence of C. irritans in fish caught during the spring (91.0 3% on average) was significantly higher than that of the fish caught during the summer (39.29 %). A wide variation in the prevalence of the parasite was shown among the fish species. The highest prevalence and intensity of the infection occurred in Plataxteira, Diodon holocanthus, Paracanthurus hepatusat 100 % of infection and density of 12 parasites/field of view (x4 magnification) while and the lowest prevalence of C. irritans appeared on Rhinecanthus aculeatus, Zancluscornutus, and Zebrasoma veliferum with less than 50% of fish infected. Clinical signs of fish infected of C. irritans showed such as tiny white spots on skin, gills, and fins; ragged fins, changes in skin colour, cloudy eyes and increase mucus production.

The effects of fatty fish intake on adolescents' nutritional status and associations with attention performance: results from the FINS-TEENS randomized controlled trial.

Science.gov (United States)

Handeland, Katina; Skotheim, Siv; Baste, Valborg; Graff, Ingvild E; Frøyland, Livar; Lie, Øyvind; Kjellevold, Marian; Markhus, Maria W; Stormark, Kjell M; Øyen, Jannike; Dahl, Lisbeth

2018-02-23

Adolescence involves changes in dietary habits that may induce imbalances in the intake of different nutrients. Fish is an important dietary source of omega-3 (n-3) long-chain polyunsaturated fatty acids (LCPUFAs), vitamin D, several minerals and high-quality protein. By using secondary outcomes and exploratory analyses, the aims of this paper were to evaluate if nutritional biomarkers (red blood cell fatty acids, serum (s)-25(OH)D, s-ferritin and urinary iodine concentration (UIC)) were altered during a dietary intervention, and if they mediated previously reported changes in attention performance. In addition, to examine the status of the biomarkers and explore associations between dietary pattern, biomarkers and attention performance cross-sectionally at baseline. The Fish Intervention Studies-TEENS (FINS-TEENS) was a three-armed intervention trial, including adolescents from eight secondary schools (n = 415; age: 14-15y) in Bergen, Norway. Participants were individually randomized to receive either fish meals, meat meals or n-3 LCPUFA supplements, three times a week for a total of 12 weeks. Blood and urine samples were collected pre and post intervention and attention performance was assessed with the d2 test of attention. Analyses of covariance (ANCOVA) assessed differences between groups in changes of biomarkers and linear mixed models were applied in analyses of attention performance and biomarkers. The trial is registered in ClinicalTrials.gov (NCT02350322). At baseline, the mean omega-3 index was 5.8 ± 1.3% and deficient status were identified for s-25(OH)D (54%), s-ferritin (10%) and UIC (40%). The intervention resulted in an increase in DHA and the omega-3 index which was larger in the supplement group compared to the fish and meat group (P < 0.01), and in the fish group compared to the meat group (P < 0.01). No differences between the groups were observed for changes in 25(OH)D, s-ferritin or UIC. None of the biomarkers mediated

A gene expression study of dorso-ventrally restricted pigment pattern in adult fins of Neolamprologus meeli, an African cichlid species

Directory of Open Access Journals (Sweden)

Ehsan Pashay Ahi

2017-01-01

Full Text Available Fish color patterns are among the most diverse phenotypic traits found in the animal kingdom. Understanding the molecular and cellular mechanisms that control in chromatophore distribution and pigmentation underlying this diversity is a major goal in developmental and evolutionary biology, which has predominantly been pursued in the zebrafish model system. Here, we apply results from zebrafish work to study a naturally occurring color pattern phenotype in the fins of an African cichlid species from Lake Tanganyika. The cichlid fish Neolamprologus meeli displays a distinct dorsal color pattern, with black and white stripes along the edges of the dorsal fin and of the dorsal half of the caudal fin, corresponding with differences in melanophore density. To elucidate the molecular mechanisms controlling the differences in dorsal and ventral color patterning in the fins, we quantitatively assessed the expression of 15 candidate target genes involved in adult zebrafish pigmentation and stripe formation. For reference gene validation, we screened the expression stability of seven widely expressed genes across the investigated tissue samples and identified tbp as appropriate reference. Relative expression levels of the candidate target genes were compared between the dorsal, striped fin regions and the corresponding uniform, grey-colored regions in the anal and ventral caudal fin. Dorso-ventral expression differences, with elevated levels in both white and black stripes, were observed in two genes, the melanosome protein coding gene pmel and in igsf11, which affects melanophore adhesion, migration and survival. Next, we predicted potential shared upstream regulators of pmel and igsf11. Testing the expression patterns of six predicted transcriptions factors revealed dorso-ventral expression difference of irf1 and significant, negative expression correlation of irf1 with both pmel and igsf11. Based on these results, we propose pmel, igsf11 and irf1 as

Toward quantum FinFET

CERN Document Server

Wang, Zhiming

2013-01-01

This book reviews a range of quantum phenomena in novel nanoscale transistors called FinFETs, including quantized conductance of 1D transport, single electron effect, tunneling transport, etc. The goal is to create a fundamental bridge between quantum FinFET and nanotechnology to stimulate readers' interest in developing new types of semiconductor technology. Although the rapid development of micro-nano fabrication is driving the MOSFET downscaling trend that is evolving from planar channel to nonplanar FinFET, silicon-based CMOS technology is expected to face fundamental limits in the near future. Therefore, new types of nanoscale devices are being investigated aggressively to take advantage of the quantum effect in carrier transport. The quantum confinement effect of FinFET at room temperatures was reported following the breakthrough to sub-10nm scale technology in silicon nanowires. With chapters written by leading scientists throughout the world, Toward Quantum FinFET provides a comprehensive introductio...

Finding NEMO (novel electromaterial muscle oscillator): a polypyrrole powered robotic fish with real-time wireless speed and directional control

International Nuclear Information System (INIS)

McGovern, Scott; Alici, Gursel; Spinks, Geoffrey; Truong, Van-Tan

2009-01-01

This paper presents the development of an autonomously powered and controlled robotic fish that incorporates an active flexural joint tail fin, activated through conducting polymer actuators based on polypyrrole (PPy). The novel electromaterial muscle oscillator (NEMO) tail fin assembly on the fish could be controlled wirelessly in real time by varying the frequency and duty cycle of the voltage signal supplied to the PPy bending-type actuators. Directional control was achieved by altering the duty cycle of the voltage input to the NEMO tail fin, which shifted the axis of oscillation and enabled turning of the robotic fish. At low speeds, the robotic fish had a turning circle as small as 15 cm (or 1.1 body lengths) in radius. The highest speed of the fish robot was estimated to be approximately 33 mm s −1 (or 0.25 body lengths s −1 ) and was achieved with a flapping frequency of 0.6–0.8 Hz which also corresponded with the most hydrodynamically efficient mode for tail fin operation. This speed is approximately ten times faster than those for any previously reported artificial muscle based device that also offers real-time speed and directional control. This study contributes to previously published studies on bio-inspired functional devices, demonstrating that electroactive polymer actuators can be real alternatives to conventional means of actuation such as electric motors

Finding NEMO (novel electromaterial muscle oscillator): a polypyrrole powered robotic fish with real-time wireless speed and directional control

Science.gov (United States)

McGovern, Scott; Alici, Gursel; Truong, Van-Tan; Spinks, Geoffrey

2009-09-01

This paper presents the development of an autonomously powered and controlled robotic fish that incorporates an active flexural joint tail fin, activated through conducting polymer actuators based on polypyrrole (PPy). The novel electromaterial muscle oscillator (NEMO) tail fin assembly on the fish could be controlled wirelessly in real time by varying the frequency and duty cycle of the voltage signal supplied to the PPy bending-type actuators. Directional control was achieved by altering the duty cycle of the voltage input to the NEMO tail fin, which shifted the axis of oscillation and enabled turning of the robotic fish. At low speeds, the robotic fish had a turning circle as small as 15 cm (or 1.1 body lengths) in radius. The highest speed of the fish robot was estimated to be approximately 33 mm s-1 (or 0.25 body lengths s-1) and was achieved with a flapping frequency of 0.6-0.8 Hz which also corresponded with the most hydrodynamically efficient mode for tail fin operation. This speed is approximately ten times faster than those for any previously reported artificial muscle based device that also offers real-time speed and directional control. This study contributes to previously published studies on bio-inspired functional devices, demonstrating that electroactive polymer actuators can be real alternatives to conventional means of actuation such as electric motors.

Multi-camera volumetric PIV for the study of jumping fish

Science.gov (United States)

Mendelson, Leah; Techet, Alexandra H.

2018-01-01

Archer fish accurately jump multiple body lengths for aerial prey from directly below the free surface. Multiple fins provide combinations of propulsion and stabilization, enabling prey capture success. Volumetric flow field measurements are crucial to characterizing multi-propulsor interactions during this highly three-dimensional maneuver; however, the fish's behavior also drives unique experimental constraints. Measurements must be obtained in close proximity to the water's surface and in regions of the flow field which are partially-occluded by the fish body. Aerial jump trajectories must also be known to assess performance. This article describes experiment setup and processing modifications to the three-dimensional synthetic aperture particle image velocimetry (SAPIV) technique to address these challenges and facilitate experimental measurements on live jumping fish. The performance of traditional SAPIV algorithms in partially-occluded regions is characterized, and an improved non-iterative reconstruction routine for SAPIV around bodies is introduced. This reconstruction procedure is combined with three-dimensional imaging on both sides of the free surface to reveal the fish's three-dimensional wake, including a series of propulsive vortex rings generated by the tail. In addition, wake measurements from the anal and dorsal fins indicate their stabilizing and thrust-producing contributions as the archer fish jumps.

75 FR 14134 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2010-03-24

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... modifications, as required by the Endangered Species Act of 1973 (16 U.S.C. 1531 1543) (ESA), is based on a... trap and beach seine, anesthesize and sample fish for species identification, tags, marks and fin clips...

The major and trace element chemistry of fish and lake water within ...

African Journals Online (AJOL)

Chemical elements in lake water are incorporated into fish tissues through bioconcentration and biomagnification. Lake water and fish tissue samples from 23 lakes, located within 4 major South African catchments, were analysed to investigate the link between element concentrations in lake water and otolith, fin spine, ...

PHASE CHANGE AROUND A FINNED TUBE

Directory of Open Access Journals (Sweden)

Aytunç EREK

2003-01-01

Full Text Available This study presents the heat transfer enhancement in the thermal energy storage system by using radially finned tube. The solution of the system consists of the solving the equations of the heat transfer fluid (HTF, the pipe wall and fin, and the phase change material (PCM as one domain. The control volume finite difference approach and the semi implicit solver (SIS are used to solve the equations. Fully developed velocity distribution is taken in the HTF. Flow parameters (Re number and inlet temperature of coolant and fin parameters (the number of fins, fin length, fin thickness are found to influence solidification fronts and the total stored energy.

Hydrodynamic thrust generation and power consumption investigations for piezoelectric fins with different aspect ratios

Science.gov (United States)

Shahab, S.; Tan, D.; Erturk, A.

2015-12-01

Bio-inspired hydrodynamic thrust generation using piezoelectric transduction has recently been explored using Macro-Fiber Composite (MFC) actuators. The MFC technology strikes a balance between the actuation force and structural deformation levels for effective swimming performance, and additionally offers geometric scalability, silent operation, and ease of fabrication. Recently we have shown that mean thrust levels comparable to biological fish of similar size can be achieved using MFC fins. The present work investigates the effect of length-to-width (L/b) aspect ratio on the hydrodynamic thrust generation performance of MFC cantilever fins by accounting for the power consumption level. It is known that the hydrodynamic inertia and drag coefficients are controlled by the aspect ratio especially for L/bdrag coefficients from the vibration response to harmonic actuation for the first bending mode. Experiments are then conducted for various actuation voltage levels to quantify the mean thrust resultant and power consumption levels for different aspect ratios. Variation of the thrust coefficient of the MFC bimorph fins with changing aspect ratio is also semi-empirically modeled and presented.

Channels with Different Fin Shapes

Directory of Open Access Journals (Sweden)

R. J. Goldstein

1998-01-01

Full Text Available The mass transfer (analogous to heat transfer and pressure loss characteristics of staggered short pin-fin arrays are investigated experimentally in the range of Reynolds number 3000 to 18,000 based on fin diameter and mean approach-flow velocity. Three different shapes of fins with aspect ratio of 2 are examined: one uniform-diameter circular fin (UDCF and two stepped-diameter circular fins (SDCF1 and SDCF2. Flow visualization using oil-lampblack reveals complex flow characteristics associated with the repeated production of horseshoe vortices and fin wakes, and the interactions among these. The SDCF1 and SDCF2 arrays show flow characteristics different from the UDCF array due to downflow from the steps. For all arrays tested, the near-endwall flow varies row by row in the initial rows until it reaches a stable pattern after the third row. The row-averaged Sherwood numbers obtained from the naphthalene sublimation experiment also show a row-by-row variation pattern similar to the flow results. While the SDCF2 array has the highest mass transfer rate, the SDCF1 array has the smallest pressure loss at the same approach-flow velocity. The fin surfaces have higher array-averaged Sherwood number than the endwall and the ratio between these changes with fin shape and Reynolds number. The performance of the pin-fin arrays is analyzed under two different constraints: the mass[heat transfer rate at fixed pumping power, and the mass/heat transfer area and pressure loss to fulfill fixed heat load at a fixed mass flow rate. In both cases, the SDCF2 array shows the best performance.

Cytogenetic adaptive response of cultured fish cells to low doses of X-rays

International Nuclear Information System (INIS)

Kurihara, Yasuyuki; Etoh, Hisami; Rienkjkarn, M.

1992-01-01

The adaptive response was examining chromosomal aberrations and micronucleus in cultured fish cells, ULF-23 (mudminnow) and CAF-31 (gold fish). When cultured fish cells were first irradiated with small doses of X-rays, they became less sensitive to subsequent exposures to high doses. The effective adaptive dose was 4.8 cGy-9.5 cGy. Adaptive doses given cells in the G1 phase were more effective than when given in the S phase. The adaptive response was maximal at 5 hours and disappeared at 10 hours after the adaptive dose. The expression of the response was inhibited by treatment with 3-aminobenzamide, as reported for mammalian cells, and with arabinofuranoside cytosine, an inhibitor of DNA polymerase alpha. Caffeine, an inhibitor of post-replicational repair, had no effect on the response. (author)

Cytogenetic adaptive response of cultured fish cells to low doses of X-rays

Energy Technology Data Exchange (ETDEWEB)

Kurihara, Yasuyuki; Etoh, Hisami (National Inst. of Radiological Sciences, Chiba (Japan)); Rienkjkarn, M.

1992-12-01

The adaptive response was examining chromosomal aberrations and micronucleus in cultured fish cells, ULF-23 (mudminnow) and CAF-31 (gold fish). When cultured fish cells were first irradiated with small doses of X-rays, they became less sensitive to subsequent exposures to high doses. The effective adaptive dose was 4.8 cGy-9.5 cGy. Adaptive doses given cells in the G1 phase were more effective than when given in the S phase. The adaptive response was maximal at 5 hours and disappeared at 10 hours after the adaptive dose. The expression of the response was inhibited by treatment with 3-aminobenzamide, as reported for mammalian cells, and with arabinofuranoside cytosine, an inhibitor of DNA polymerase alpha. Caffeine, an inhibitor of post-replicational repair, had no effect on the response. (author).

The evolution of pharyngognathy: a phylogenetic and functional appraisal of the pharyngeal jaw key innovation in labroid fishes and beyond.

Science.gov (United States)

Wainwright, Peter C; Smith, W Leo; Price, Samantha A; Tang, Kevin L; Sparks, John S; Ferry, Lara A; Kuhn, Kristen L; Eytan, Ron I; Near, Thomas J

2012-12-01

The perciform group Labroidei includes approximately 2600 species and comprises some of the most diverse and successful lineages of teleost fishes. Composed of four major clades, Cichlidae, Labridae (wrasses, parrotfishes, and weed whitings), Pomacentridae (damselfishes), and Embiotocidae (surfperches); labroids have been an icon for studies of biodiversity, adaptive radiation, and sexual selection. The success and diversification of labroids have been largely attributed to the presence of a major innovation in the pharyngeal jaw apparatus, pharyngognathy, which is hypothesized to increase feeding capacity and versatility. We present results of large-scale phylogenetic analyses and a survey of pharyngeal jaw functional morphology that allow us to examine the evolution of pharyngognathy in a historical context. Phylogenetic analyses were based on a sample of 188 acanthomorph (spiny-rayed fish) species, primarily percomorphs (perch-like fishes), and DNA sequence data collected from 10 nuclear loci that have been previously used to resolve higher level ray-finned fish relationships. Phylogenies inferred from this dataset using maximum likelihood, Bayesian, and species tree analyses indicate polyphyly of the traditional Labroidei and clearly separate Labridae from the remainder of the traditional labroid lineages (Cichlidae, Embiotocidae, and Pomacentridae). These three "chromide" families grouped within a newly discovered clade of 40 families and more than 4800 species (>27% of percomorphs and >16% of all ray-finned fishes), which we name Ovalentaria for its characteristic demersal, adhesive eggs with chorionic filaments. This fantastically diverse clade includes some of the most species-rich lineages of marine and freshwater fishes, including all representatives of the Cichlidae, Embiotocidae, Pomacentridae, Ambassidae, Gobiesocidae, Grammatidae, Mugilidae, Opistognathidae, Pholidichthyidae, Plesiopidae (including Notograptus), Polycentridae, Pseudochromidae

Relationships of mercury concentrations across tissue types, muscle regions and fins for two shark species

KAUST Repository

O'Bryhim, Jason R.

2017-01-31

Mercury (Hg) exposure poses a threat to both fish and human health. Sharks are known to bioaccumulate Hg, however, little is known regarding how Hg is distributed between different tissue groups (e.g. muscle regions, organs). Here we evaluated total mercury (THg) concentrations from eight muscle regions, four fins (first dorsal, left and right pectorals, caudal-from both the inner core and trailing margin of each fin), and five internal organs (liver, kidney, spleen, heart, epigonal organ) from two different shark species, bonnethead (Sphyrna tiburo) and silky shark (Carcharhinus falciformis) to determine the relationships of THg concentrations between and within tissue groups. Total Hg concentrations were highest in the eight muscle regions with no significant differences in THg concentrations between the different muscle regions and muscle types (red and white). Results from tissue collected from any muscle region would be representative of all muscle sample locations. Total Hg concentrations were lowest in samples taken from the fin inner core of the first dorsal, pectoral, and caudal (lower lobe) fins. Mercury concentrations for samples taken from the trailing margin of the dorsal, pectoral, and caudal fins (upper and lower lobe) were also not significantly different from each other for both species. Significant relationships were found between THg concentrations in dorsal axial muscle tissue and the fin inner core, liver, kidney, spleen and heart for both species as well as the THg concentrations between the dorsal fin trailing margin and the heart for the silky shark and all other sampled tissue types for the bonnethead shark. Our results suggest that biopsy sampling of dorsal muscle can provide data that can effectively estimate THg concentrations in specific organs without using more invasive, or lethal methods.

An experimental investigation on the airside performance of fin-and-tube heat exchangers having slit fins under wet condition

International Nuclear Information System (INIS)

Kim, Nae Hyun; Kim, Tae Hun

2015-01-01

In this study, the heat transfer and friction characteristics of the 5.3 mm O.D. slit-finned heat exchangers under wet condition have been experimentally investigated. Plain-finned heat exchangers having the same 5.3 mm O.D. tubes are also tested for comparison purpose. The effect of fin pitch on j and f factor is negligible. Slit fin samples yield higher j and f factors than plain fin samples. For one row configuration, the average f factor ratio between slit fin sample and plain fin sample is 2.18. The ratio increases to 2.41 for two row configuration, and to 2.65 for three row configuration. As for the j factor, the ratios are approximately the same (1.61, 1.70 and 1.71 for one, two and three row configuration). Both j and f factor increase as the number of tube row decreases. The same trend is observed for the plain fin samples. At high Reynolds numbers, the j/f ratios of the slit fin are approximately the same as those of the plain fin. At low Reynolds numbers, the j/f ratios of the slit fin are smaller than those of plain fin. Data are compared with existing correlations.

The South American freshwater fish Prochilodus lineatus (Actinopterygii: Characiformes: Prochilodontidae): new species in Vietnamese aquaculture

Czech Academy of Sciences Publication Activity Database

Kalous, L.; Bui, A.T.; Petrtýl, M.; Bohlen, Jörg; Chaloupková, P.

2012-01-01

Roč. 43, č. 6 (2012), 955-958 ISSN 1355-557X Grant - others:MZe(CZ) 29/MZe/B/08-10 Institutional research plan: CEZ:AV0Z50450515 Keywords : exotic species * aquaculture * Prochilodus lineatus Subject RIV: GL - Fishing Impact factor: 1.422, year: 2012

Experimental Investigation on Effect of Fin Shape on the Thermal-Hydraulic Performance of Compact Fin-and-Tube Heat Exchangers

Science.gov (United States)

Moorthy, P.; Oumer, A. N.; Ishak, M.

2018-03-01

The aim of this paper is to investigate the effect of fin shapes on the performance of compact finned flat tube heat exchangers. Three types of fin shapes namely plain, wavy, and rectangular grooved fins attached to three by three arrays of flat tube banks were considered. Moreover, the tubes were deployed in in-line and staggered arrangements. In addition to the fin shapes, the air velocity and the tube inclination angles were varied and the thermal-hydraulic performance was analysed. On the other hand, the temperatures at the tube surfaces were kept constant to produce constant heat flux throughout the study. The results showed that as flowrate increases, the heat transfer increases, however, the friction factor decreases. Staggered arrangement produces higher heat transfer and friction factor than inline fin. Moreover, the rectangular fin is the best in terms of high heat transfer however the drawback of high friction factor leads the fin to have the least efficiency of all. On the other hand, plain fin had the least heat transfer performance however the highest efficiency was achieved. Therefore, plain fin should be used when efficiency is prioritized and rectangular fin when high heat transfer is desired.

Attempt at cloning high-quality goldfish breed 'Ranchu' by fin-cultured cell nuclear transplantation.

Science.gov (United States)

Tanaka, Daisuke; Takahashi, Akito; Takai, Akinori; Ohta, Hiromi; Ueno, Koichi

2012-02-01

The viability of ornamental fish culture relies on the maintenance of high-quality breeds. To improve the profitability of culture operations we attempted to produce cloned fish from the somatic nucleus of the high-quality Japanese goldfish (Carassius auratus auratus) breed 'Ranchu'. We transplanted the nucleus of a cultured fin-cell from an adult Ranchu into the non-enucleated egg of the original goldfish breed 'Wakin'. Of the 2323 eggs we treated, 802 underwent cleavage, 321 reached the blastula stage, and 51 reached the gastrula stage. Two of the gastrulas developed until the hatching stage. A considerable number of nuclear transplants retained only the donor nucleus. Some of these had only a 2n nucleus derived from the same donor fish. Our results provide insights into the process of somatic cell nuclear transplantation in teleosts, and the cloning of Ranchu.

Numeric Simulation on the Performance of an Undulating Fin in the Wake of a Periodic Oscillating Plate

Directory of Open Access Journals (Sweden)

Zhang Yong-Hua

2013-10-01

Full Text Available A two-dimensional unsteady computational fluid dynamics (CFD method using an unstructured, grid-based and unsteady Navier-Stokes solver with automatic adaptive re-meshing to compute the unsteady flow was adopted to study the hydrodynamic interaction between a periodic oscillating plate and a rigid undulating fin in tandem arrangement. The user-defined function (UDF program was compiled to define the undulating and oscillating motion. First, the influence of the distance between the anterior oscillating plate and the posterior undulating fin on the non-dimensional drag coefficient of the fin was investigated. Ten different distances, D=0.2L, 0.4L, 0.6L, 0.8L, 1.0L, 1.2L, 1.4L, 1.6L, 1.8L and 2.0L, were considered. The performance of the fin for different distances (D is different. Second, the plate oscillating angle (5.7°, 10°, 20°, 30°, 40°, 45°, 50° and frequency (0.5 Hz, 1.0 Hz, 1.5 Hz, 2.0 Hz, 2.5 Hz, 3.0 Hz, 3.5 Hz, 4.0 Hz effects on the non-dimensional drag coefficient of the fin were also implemented. The pressure distribution on the fin was computed and integrated to provide fin forces, which were decomposed into lift and thrust. Meanwhile, the flow field was demonstrated and analysed. Based on the flow structures, the reasons for different undulating performances were discussed. It shows that the results largely depend on the distance between the two objects. The plate oscillating angle and frequency also make a certain contribution to the performance of the posterior undulating fin. The results are similar to the interaction between two undulating objects in tandem arrangement and they may provide a physical insight into the understanding of fin interaction in fishes or bio-robotic underwater propulsors that are propelled by multi fins.

Isopods (Isopoda: Aegidae, Cymothoidae, Gnathiidae associated with Venezuelan marine fishes (Elasmobranchii, Actinopterygii

Directory of Open Access Journals (Sweden)

Lucy Bunkley-Williams

2006-12-01

Full Text Available The parasitic isopod fauna of fishes in the southern Caribbean is poorly known. In examinations of 12 639 specimens of 187 species of Venezuelan fishes, the authors found 10 species in three families of isopods (Gnathiids, Gnathia spp. from Diplectrum radiale *, Heteropriacanthus cruentatus *, Orthopristis ruber * and Trachinotus carolinus *; two aegids, Rocinela signata from Dasyatis guttata *, H. cruentatus *, Haemulon aurolineatum *, H. steindachneri * and O. ruber ; and Rocinela sp. from Epinephelus flavolimbatus *; five cymothoids: Anilocra haemuli from Haemulon boschmae *, H. flavolineatum * and H. steindachneri *; Anilocra cf haemuli from Heteropriacanthus cruentatus *; Haemulon bonariense*, O. ruber*, Cymothoa excisa in H. cruentatus *; Cymothoa oestrum in Chloroscombrus chrysurus, H. cruentatus* and Priacanthus arenatus ; Cymothoa sp. in O. ruber; Livoneca sp. from H. cruentatus *; and Nerocila fluviatilis from H. cruentatus * and P. arenatus *. The Rocinela sp. and A. cf haemuli in the southern Caribbean could represent new species. The abundance of A. cf haemuli appears to have drastically reduced from 1994 to 1999 in the Gulf of Cariaco. The Cymothoa sp. represents an undescribed species that is apparently host specific to O. ruber . It does not occur in the Gulf of Cariaco, but is relatively abundant on the Caribbean coast of Sucre State, Venezuela. The Livoneca sp. is an undescribed species host specific to Diapterus rhombeus, Cymothoa excisa and C. oestrum were thought to have distinct host preferences, but both infected the Heteropriacanthus cruentatus in the present study.Gnathia spp. are reported from Venezuelan waters for the first time. Twenty new host records* are noted. The fish-associated isopod fauna is much more extensive and important than has previously been suspected. Rev. Biol. Trop. 54 (Suppl. 3: 175-188. Epub 2007 Jan. 15.Se conoce muy poco acerca de la fauna de isópodos parásitos de peces en el Caribe Sur. Tras

Do culinary preparations influence 210Po activity concentration in fin fishes?

International Nuclear Information System (INIS)

Praveen Pole, R.P.; Godwin Wesley, S.; Rajan, M.P

2013-01-01

Polonium-210, a member of the 238 U series, is a major source of internal radiation dose to marine organisms and human beings. This naturally occurring radionuclide is responsible for a considerable proportion of radiation exposure of humans, in particular, through consumption of seafood. Considering all these facts, many countries and various international agencies have carried out studies for assessing the levels of 210 Po globally. The volatile nature of 210 Po at high temperatures would significantly reduce its activity concentration in various culinary preparations of seafood. Some studies of fishes have shown no measurable reduction in 210 Po activity in culinary preparations and some authors have reported measurable increase. Based on this scenario, the present study was aimed at estimating 210 Po activity concentrations in different culinary preparations of fishes traditionally prevalent in the coastal region of southern Tamil Nadu. The commonly available fish species (Sardinella sp., Leiognathus sp., Katsuwonus sp., Stolephorus sp. and Chirocentrus sp.) consumed more by the people of this region were collected from nearby fish-landing centre (Kanyakumari and Manakudi). The samples were washed thoroughly with tap water and eviscerated. The fillets were divided into four groups. Fresh fillets analysed as such; A portion of the sample was subjected to oil-frying (with commonly used spices and salt); One portion of the sample was salt-dried; Another portion of the sample was boiled (curry) along with common spices and salt. Ten to twenty grams of each sample was subjected to wet-digestion using 70% conc. HNO 3 followed by the addition of 40% H 2 O 2

Advanced microchannel heat exchanger with S-shaped fins

International Nuclear Information System (INIS)

Tsuzuki, Nobuyoshi; Ishizuka, Takao; Kato, Yasuyoshi; Nikitin, Konstantin

2009-01-01

Fin shape effects on thermal-hydraulic characteristics were studied for a Microchannel Heat Exchanger (MCHE) with S-shaped fins using 3D-CFD and changing the fin parameters: fin angle, overlapping length, fin width, fin length, and edge roundness. The fin angle effect on the pressure drop is consistent with the equation obtained experimentally by Weisbach for a circular bent tube: the pressure drop in the S-shaped fin configuration results from bent flow. The overlap of fins with those located immediately downstream at the offset position provides a guide wing effect that reduces the pressure drop remarkably. The overlap was changed by changing the fin radial position and arc length. The pressure drop was minimized when the downstream fins are placed in the middle of the bent flow channels formed by the fins upstream, which differs from Ito's configuration obtained from experiments with a single bent duct. Regarding arc length, the pressure drop is minimized at the standard overlapping length, which was formed to have the longest arc without a change in channel width. Shorter arc lengths from the optimum value by 30 and 50%, respectively, give 2.4 and 4.6% decreases in the heat transfer rate and 17 and 13% increases in the pressure drop. Thinner fins show better thermal-hydraulic performance for fin widths of 0.2-0.8 mm. However, the pressure drop reduced by the longer fin and heat transfer rate was also reduced. Rounded fins with 0.1 mm radius increased the pressure drop by about 30% compared with that of the fin designed with no roundness. (author)

A new species of parasitic copepod, Sarcotretes umitakae sp. n. (Siphonostomatoida, Pennellidae, on the rattail (Actinopterygii, Macrouridae from the East China Sea, Japan

Directory of Open Access Journals (Sweden)

Daisuke Uyeno

2012-11-01

Full Text Available A new species of copepod, Sarcotretes umitakae sp. n., of the siphonostomatoid family Pennellidae is described based on female specimens from the rattail Coelorinchus jordani Smith and Pope (Actinopterygii: Gadiformes: Macrouridae caught in the East China Sea. This species is characterized by exhibiting the following characters: the large proboscis projects strongly; the head bears paired lateral processes which are bulbous and taper into a slender horn; the twisting neck is significantly longer than the trunk; and the trunk bears an anterior constriction with a reduced abdomen.

Fin shape thermal optimization using Bejan's constuctal theory

CERN Document Server

Lorenzini, Giulio

2011-01-01

The book contains research results obtained by applying Bejan's Constructal Theory to the study and therefore the optimization of fins, focusing on T-shaped and Y-shaped ones. Heat transfer from finned surfaces is an example of combined heat transfer natural or forced convection on the external parts of the fin, and conducting along the fin. Fin's heat exchange is rather complex, because of variation of both temperature along the fin and convective heat transfer coefficient. Furthermore possible presence of more fins invested by the same fluid flow has to be considered.Classical fin theory tri

Experimental Validation of Elliptical Fin-Opening Behavior

Directory of Open Access Journals (Sweden)

James M. Garner

2003-01-01

Full Text Available An effort to improve the performance of ordnance has led to the consideration of the use of folding elliptical fins for projectile stabilization. A second order differential equation was used to model elliptical fin deployment history and accounts for: deployment with respect to the geometric properties of the fin, the variation in fin aerodynamics during deployment, the initial yaw effect on fin opening, and the variation in deployment speed based on changes in projectile spin. This model supports tests conducted at the Transonic Experimental Facility, Aberdeen Proving Ground examining the opening behavior of these uniquely shaped fins. The fins use the centrifugal force from the projectile spin to deploy. During the deployment, the fin aerodynamic forces vary with angle-of-attack changes to the free stream. Model results indicate that projectile spin dominates the initial opening rates and aerodynamics dominate near the fully open state. The model results are examined to explain the observed behaviors, and suggest improvements for later designs.

Comparative Allometric Growth of the Mimetic Ephippid Reef Fishes Chaetodipterus faber and Platax orbicularis.

Directory of Open Access Journals (Sweden)

Breno Barros

Full Text Available Mimesis is a relatively widespread phenomenon among reef fish, but the ontogenetic processes relevant for mimetic associations in fish are still poorly understood. In the present study, the allometric growth of two allopatric leaf-mimetic species of ephippid fishes, Chaetodipterus faber from the Atlantic and Platax orbicularis from the Indo-Pacific, was analyzed using ten morphological variables. The development of fins was considered owing to the importance of these structures for mimetic behaviors during early life stages. Despite the anatomical and behavioral similarities in both juvenile and adult stages, C. faber and P. orbicularis showed distinct patterns of growth. The overall shape of C. faber transforms from a rounded-shape in mimetic juveniles to a lengthened profile in adults, while in P. orbicularis, juveniles present an oblong profile including dorsal and anal fins, with relative fin size diminishing while the overall profile grows rounder in adults. Although the two species are closely-related, the present results suggest that growth patterns in C. faber and P. orbicularis are different, and are probably independent events in ephippids that have resulted from similar selective processes.

Effect of Using Extra Fins on the Pin Fin Classic Geometry for Enhancement Heat Sink Performance using EGM Method

Directory of Open Access Journals (Sweden)

Kadhum Audaa Jehhef

2018-04-01

Full Text Available In the present study, the effect of new cross-section fin geometries on overall thermal/fluid performance had been investigated. The cross-section included the base original geometry of (triangular, square, circular, and elliptical pin fins by adding exterior extra fins along the sides of the origin fins. The present extra fins include rectangular extra fin of 2 mm (height and 4 mm (width and triangular extra fin of 2 mm (base 4 mm (height. The use of entropy generation minimization method (EGM allows the combined effect of thermal resistance and pressure drop to be assessed through the simultaneous interaction with the heat sink. A general dimensionless expression for the entropy generation rate is obtained by considering a control volume around the pin fin including a base plate and applying the conservations equations of mass and energy with the entropy balance. The dimensionless numbers used includes the aspect ratio (ε, Reynolds number (Re, Nusselt number (Nu, and the drag coefficients (CD. Fourteen different cross-section fin geometries are examined for the heat transfer, fluid friction, and the minimum entropy generation rate. The results showed that the Nusselt number increases with increasing the Reynolds number for all employed models. The ellipse models (ET and ER-models give the highest value in the Nusselt number as compared with the classical pin fins. The fin of the square geometry with four rectangular extra fins (SR-models gives an agreement in Nusselt number as compared with the previous study.

A possible cause of sunburn in fish

Science.gov (United States)

1958-01-01

A LESION DESCRIBED AS A GRAY ΡATCH GENERALLY LOCATED ΑΝΤΕRIOR TO THE DORSAL FIN has been associated with high mortality of fish on numerous occasions in production hatcheries throughout the United States. This lesion has been called "sunburn" or "backpeel." No bacteria or other pathogens have been found in fish with these symptoms. For example, at a Montana hatchery in April 1956, mortality of 10 to 15 percent occurred daily and this lesion was the only syndrome found.  On occasion, shade has prevented this condition and even restored affected fish to an apparent normal condition; thus there has seemed to be a correlation between sunshine and the condition in fish. To our knowledge, this has been the only therapy attempted.

Determination of metal balance shift induced in small fresh water fish by X-ray irradiation using PIXE analysis

International Nuclear Information System (INIS)

Yukawa, M.; Aoki, K.; Iso, H.; Kodama, K.; Imaseki, H.; Ishikawa, Y.

2005-01-01

In the environmental pollution studies, it is very important to detect not only pollutants but also changes induced in organisms in the environment with various environmental stresses such as heavy metal toxicity radiation and agricultural chemicals. In the latter, monitoring is carried out using biological indicators to find out the changes, which have wide spectra from visible like deformity of the body to invisible such as changes in some enzyme activities. Changes of the balance of essential elements could occur in organisms to deal with the stresses. If we detect an elemental balance shift, we may see the environmental pollution in its early stages. Moreover, in the actual environment, combined effects, additive or reductive with coexistent elements or other stresses, is an important subject for investigation. Therefore, measurement of many elements in the biological indicator's simultaneously and determination of the distribution in the organisms are useful in clarifying the action of pollutants at sublethal levels. A small fresh water fish, Medaka can be used as one of the biological-indicators for determination of water quality. In the National Institute of Radiological Sciences (NIRS), an inbred strain of Medaka Orizias laptipes was established and has been maintained for the research purposes. Since the genetic background of inbred animals is almost uniform, the individual deviation among animals is very small. This characteristic is very useful to investigate the physiological effects of environmental stresses. We have continued to investigate the balance shift of essential elements induced in the bodies of Medaka by several stresses. In this paper, elemental content in various organs of the X-ray irradiated fish determined by PIXE method are reported in comparison with that of the control fish to observe the effect of the X-rays. Body size of Medaka is about 3 cm long, and the internal organs are very small (about l mm on average). PIXE is the most

The skin: The many functions of fish integument

Science.gov (United States)

Elliott, Diane G.; Farrell, Anthony P.

2011-01-01

The integument or skin is the envelope that not only separates and protects a fish from its environment, but also provides the means through which most contacts with the outer world are made. It is a large organ and is continuous with the linings of all body openings, and also covers the fins. Fish integument is a multifunctional organ, and its components may serve important roles in protection, communication, sensory perception, locomotion, respiration, ion regulation, excretion, and thermal regulation.

Investigations of X-ray irradiation of marine fish aboard

International Nuclear Information System (INIS)

Karnop, G.; Reinacher, E.; Antonacopoulos, N.; Meyer, V.

1976-01-01

Studies on X-ray irradiation of ocean perch, cod and coley (at doses of 50-150 krad) are described. The results show that irradiation within this dose range has no significant effect on the shelf-life of fish stored in ice. Although irradiation positively influenced bacteriological and chemical characteristics (e.g. reduction of total aerobic count, and inhibition of decomposition of N-containing compounds), the organoleptically-limited shelf-life of irradiated specimens was similar to that of non-irradiated specimens. Organoleptic changes in irradiated and in non-irradiated samples differed; this is attributed to the abnormal spoilage flora (mainly radiation-resistant Moraxella spp.) in the irradiated samples. (orig./HP) [de

从FinTech到RegTech

Institute of Scientific and Technical Information of China (English)

孙国峰[1,2

2017-01-01

本文分析FinTech（金融科技）监管的必要性，并介绍了FinTech监管的国际经验，在此基础上提出了我国可以探索将人工智能应用于金融监管，即以RegTech（监管科技）应对FinTech的建议。

Thermal transport in oblique finned microminichannels

CERN Document Server

Fan, Yan; Singh, Pawan Kumar; Lee, Yong Jiun

2015-01-01

The main aim of this book is to introduce and give an overview of a novel, easy, and highly effective heat transfer augmentation technique for single-phase micro/minichannel heat sink. The specific objectives of the volume are to: Introduce a novel planar oblique fin microchannel and cylindrical oblique fin minichannel heat sink design using passive heat transfer enhancement techniques  Investigate the thermal transport in both planar and cylindrical oblique fin structures through numerical simulation and systematic experimental studies. Evaluate the feasibility of employing the proposed solution in cooling non-uniform heat fluxes and hotspot suppression Conduct the similarity analysis and parametric study to obtain empirical correlations to evaluate the total heat transfer rate of the oblique fin heat sink Investigate the flow mechanism and optimize the dimensions of cylindrical oblique fin heat sink Investigate the influence of edge effect on flow and temperature uniformity in these oblique fin chan...

UOP FIN 571 Final Exam Guide New

OpenAIRE

ADMIN

2018-01-01

UOP FIN 571 Final Exam Guide New Check this A+ tutorial guideline at http://www.fin571assignment.com/fin-571-uop/fin-571-final-exam-guide -latest For more classes visit http://www.fin571assignment.com Question 1 The underlying assumption of the dividend growth model is that a stock is worth: A. An amount computed as the next annual dividend divided by the required rate of return. B. An amount computed as the next annual dividend divided by the ma...

First record of the silver-cheeked toad fish Lagocephalus scleratus (Gmelin, 1789 (Actinopterygii: Tetraodontidae from Chennai coastal waters, Southeast India

Directory of Open Access Journals (Sweden)

Krishnan Silambarasan

2017-04-01

Full Text Available The silver-cheeked toad fish, Lagocephalus scleratus, was recorded for the first time on 25 September 2014. Two specimens of this fish species were collected from the by-catch landed by a commercial deep-sea trawler at Kasimedu Fishing Harbour, Chennai coast, Southeast India. The morphometric and meristic characters of the recorded specimens are described and discussed. The specimen was compared with earlier reports.

Early larvae ontogeny of the Neotropical fishes: Prochilodus costatus and P. argenteus (Characiformes: Prochilodontidae).

Science.gov (United States)

dos Santos, José Enemir; Sales, Naiara Guimarães; dos Santos, Marcella Lourenço; Arantes, Fábio Pereira; Godinho, Hugo Pereira

2016-06-01

Early development of fish larvae is a highly dynamic process and its study may provide important information about ontogenetic development, bioenergetic growth, behaviour, taxonomic characteristics for identification in natural environments, identification of spawning areas, and population monitoring. With the aim to provide knowledge about their growth and behaviour, to support larval rearing, and also taxonomic purposes, we studied the life history of the Prochilodus argenteus and P. costatus from hatching until the complete absorption of the yolk. Larvae were obtained through artificial reproduction at the Hydrobiology and Aquaculture Station of Três Marias, Minas Gerais, Brazil. Immediately after hatching, 100 larvae of each species were put in two plastic incubators for conditioning. On a daily basis, larvae behavior was recorded and 14 larvae of each species were collected to analyse body morphology. On the first day after hatching, larvae of P. costatus and P. argenteus showed an elongated and transparent body; the yolk sac was filled with individualized yolk globules. In both species, the embryonic fin rounded the caudal region of the body, the retina was non-pigmented and the gut was obliterated. At the second day post-hatching, larvae of both species dendritic chromatophores had emerged, the mouth was obliterated and the pectoral fin was observed. The larvae showed 38-43 myomeres in P. costatus and 42-43 in P. argenteus. For both species, the gas bladder was inflated and the lumen of the gut was already open. On the third day post-hatching, the mouth of P. costatus and P. argenteus was already open in a sub-terminal position; the retina was pigmented; the gill arches had lamellar protrusions and were partially covered by the operculum. On the fourth day post-hatching, the pigmentation pattern was maintained with greater intensity; the mouth occupied a terminal position, the yolk sac was almost completely reabsorbed, and the pectoral and caudal fins

Tracking transparent monogenean parasites on fish from infection to maturity

Directory of Open Access Journals (Sweden)

Alejandro Trujillo-González

2015-12-01

Full Text Available The infection dynamics and distribution of the ectoparasitic fish monogenean Neobenedenia sp. (Monogenea: Capsalidae throughout its development was examined on barramundi, Lates calcarifer (Bloch (Latidae, by labelling transparent, ciliated larvae (oncomiracidia with a fluorescent dye. Replicate fish were each exposed to approximately 50 fluorescent oncomiracidia and then examined for parasites using an epifluorescence stereomicroscope at 10 time intervals post-exposure (15, 30, 60, 120 min, 24, 48 h, four, eight, 12, and 16 days. Fluorescent labelling revealed that parasites attached underneath and on the surface of the scales of host fish. Parasite infection success was 20% within 15 min, and peaked at 93% two days post-exposure, before gradually declining between four and sixteen days. Differences in parasite distribution on L. calcarifer over time provided strong evidence that Neobenedenia sp. larvae settled opportunistically and then migrated to specific microhabitats. Parasites initially attached (<24 h in greater mean numbers on the body surface (13 ± 1.5 compared to the fins (4 ± 0.42 and head region (2 ± 0.41. Once larvae recruitment had ceased (48 h, there were significantly higher mean post-larvae counts on the head (5 ± 3.4 and fins (12 ± 3 compared to previous time intervals. Neobenedenia sp. aggregated on the eyes, fins, and dorsal and ventral extremities on the main body. As parasites neared sexual maturity, there was a marked aggregation on the fins (22 ± 2.35 compared to the head (4 ± 0.97 and body (9 ± 1.33, indicating that Neobenedenia sp. may form mating aggregations.

Drinking by amphibious fish: convergent evolution of thirst mechanisms during vertebrate terrestrialization.

Science.gov (United States)

Katayama, Yukitoshi; Sakamoto, Tatsuya; Saito, Kazuhiro; Tsuchimochi, Hirotsugu; Kaiya, Hiroyuki; Watanabe, Taro; Pearson, James T; Takei, Yoshio

2018-01-12

Thirst aroused in the forebrain by angiotensin II (AngII) or buccal drying motivates terrestrial vertebrates to search for water, whereas aquatic fish can drink surrounding water only by reflex swallowing generated in the hindbrain. Indeed, AngII induces drinking through the hindbrain even after removal of the whole forebrain in aquatic fish. Here we show that AngII induces thirst also in the amphibious mudskipper goby without direct action on the forebrain, but through buccal drying. Intracerebroventricular injection of AngII motivated mudskippers to move into water and drink as with tetrapods. However, AngII primarily increased immunoreactive c-Fos at the hindbrain swallowing center where AngII receptors were expressed, as in other ray-finned fish, and such direct action on the forebrain was not found. Behavioural analyses showed that loss of buccal water on land by AngII-induced swallowing, by piercing holes in the opercula, or by water-absorptive gel placed in the cavity motivated mudskippers to move to water for refilling. Since sensory detection of water at the bucco-pharyngeal cavity like 'dry mouth' has recently been noted to regulate thirst in mammals, similar mechanisms seem to have evolved in distantly related species in order to solve osmoregulatory problems during terrestrialization.

Ecomorphology and resource use by dominant species of tropical estuarine juvenile fishes

Directory of Open Access Journals (Sweden)

André Luiz Machado Pessanha

Full Text Available Eleven ecomorphological attributes and diet of seventeen juvenile fish species were examined to test the hypothesis that morphological patterns determine resource uses in estuarine habitats. Species were separated according to the apparatus to food capture and habitat use (benthic or pelagic in three different groups: (1 a group with depressed fish body, strong caudal peduncle and enlarged pectoral fins; (2 a second group laterally flattened with a wide protruding mouth, and (3 a third group strongly flattened with small pectorals fins. The following six trophic groups were organized based on prey categories: Zooplanktivores, Benthivores, Omnivores, Detritivores, Macrocarnivores and Insectivores. Significant results (PERMANOVA between ecomorphological indices and habitat and between ecomorphological indices and trophic groups were found. These data indicate that similarity of ecomorphological forms, which minimize the influence of environment and partitioning of food, would help facilitate the co-existence of these fish when they are abundant in this tropical estuary.

A new pachyrhizodontid fish (Actinopterygii, Teleostei from the Muhi Quarry (Albian-Cenomanian, Hidalgo, Mexico

Directory of Open Access Journals (Sweden)

G. Arratia

2018-03-01

Full Text Available A new genus and species – Motlayoichthys sergioi (ZooBank registration: urn:lsid:zoobank.org:pub:2C503741-2362-4234-8CE0-BB7D8BE5A236, urn:lsid:zoobank.org:act:EF5040FD-F306-4C0F-B9DA-2CC696CA349D – from the Cretaceous (Albian-Cenomanian of the Muhi Quarry, Hidalgo, central Mexico is assigned to the family Pachyrhizodontidae based on the presence of the inner premaxillary tooth and a few other cranial characters. Its unique suite of characters, that includes several autapomorphies supports its assignment as a new genus and species, such as the presence of a triangular head with three sides of similar lengths and with its deepest part at the level of the supraoccipital region; the lower jaw projecting anterior to the premaxilla; the ornamentation of cranial bones – especially those of the cheek region – consisting of fine longitudinal crests densely covering the bony surfaces; one or a few deep grooves on the mandibular teeth, which in addition bear acrodin tips ornamented with fine parallel striae; and the position of the dorsal fin, near the posterior margin of the cranium. Motlayoichthys n. gen., together with Michin, Pachyrhizodus, Rhacolepis, and Notelops, is part of the early radiation of pachyrhizodontoids during Albian times.

Assessment of Heavy Metals in the Fish Collected from the River Ravi, Pakistan

Directory of Open Access Journals (Sweden)

Ghazala Jabeen*, Muhammad Javed and Hamda Azmat

2012-01-01

Full Text Available The toxicity of heavy metals viz. aluminium (Al, arsenic (As, barium (Ba, chromium (Cr, nickel (Ni and zinc (Zn in fish at three main public fishing sites of the river Ravi viz. Shahdara bridge, Baloki headworks and Sidhnai barrage has been studied from June, 2009 to May, 2010. The concentrations of heavy metals in the body organs (gills, liver, kidney, intestine, reproductive organs, skin, muscle, fins, scales, bones, fats of three fish species viz. Catla catla, Labeo rohita and Cirrhina mrigala were determined. The present results reveal that the toxicity of metals fluctuated significantly in fish at all the three sampling stations with season. The fish samples collected from all the three sampling stations had significantly higher aluminium and zinc. However, the fish at Sidhnai barrage showed significantly lower metallic toxicity, followed by that at Baloki headworks and Shahdara bridge. Significantly higher metals were observed in fish liver, followed by that of kidney, gills, intestine, reproductive organs, skin, scales, fins, bones, muscle and fats. The accumulation of metals in carnivorous fish body organs showed significantly direct dependence on the metallic toxicity of herbivorous cyprinids. Fish liver and kidney showed significantly higher abilities for the accumulation of all metals while accumulations were lowest in fish muscle and fats. The health status of river Ravi at three main public fishing sites viz. Shahdara bridge, Baloki headworks and Sidhnai barrage, with respect to eco-toxicity of Al, As, Ba, Cr, Ni and Zn was above the recommended permissible standards.

Numerical studies on heat transfer and pressure drop characteristics of flat finned tube bundles with various fin materials

Science.gov (United States)

Peng, Y.; Zhang, S. J.; Shen, F.; Wang, X. B.; Yang, X. R.; Yang, L. J.

2017-11-01

The air-cooled heat exchanger plays an important role in the field of industry like for example in thermal power plants. On the other hand, it can be used to remove core decay heat out of containment passively in case of a severe accident circumstance. Thus, research on the performance of fins in air-cooled heat exchangers can benefit the optimal design and operation of cooling systems in nuclear power plants. In this study, a CFD (Computational Fluid Dynamic) method is implemented to investigate the effects of inlet velocity, fin spacing and tube pitch on the flow and the heat transfer characteristics of flat fins constructed of various materials (316L stainless steel, copper-nickel alloy and aluminium). A three dimensional geometric model of flat finned tube bundles with fixed longitudinal tube pitch and transverse tube pitch is established. Results for the variation of the average convective heat transfer coefficient with respect to cooling air inlet velocity, fin spacing, tube pitch and fin material are obtained, as well as for the pressure drop of the cooling air passing through finned tube. It is shown that the increase of cooling air inlet velocity results in enhanced average convective heat transfer coefficient and decreasing pressure drop. Both fin spacing and tube pitch engender positive effects on pressure drop and have negative effects on heat transfer characteristics. Concerning the fin material, the heat transfer performance of copper-nickel alloy is superior to 316L stainless steel and inferior to aluminium.

Climatic vulnerability of the world’s freshwater and marine fishes

Science.gov (United States)

Comte, Lise; Olden, Julian D.

2017-10-01

Climate change is a mounting threat to biological diversity, compromising ecosystem structure and function, and undermining the delivery of essential services worldwide. As the magnitude and speed of climate change accelerates, greater understanding of the taxonomy and geography of climatic vulnerability is critical to guide effective conservation action. However, many uncertainties remain regarding the degree and variability of climatic risk within entire clades and across vast ecosystem boundaries. Here we integrate physiological estimates of thermal sensitivity for 2,960 ray-finned fishes with future climatic exposure, and demonstrate that global patterns of vulnerability differ substantially between freshwater and marine realms. Our results suggest that climatic vulnerability for freshwater faunas will be predominantly determined by elevated levels of climatic exposure predicted for the Northern Hemisphere, whereas marine faunas in the tropics will be the most at risk, reflecting their higher intrinsic sensitivity. Spatial overlap between areas of high physiological risk and high human impacts, together with evidence of low past rates of evolution in upper thermal tolerance, highlights the urgency of global conservation actions and policy initiatives if harmful climate effects on the world’s fishes are to be mitigated in the future.

Saddle-fin cell transistors with oxide etch rate control by using tilted ion implantation (TIS-fin) for sub-50-nm DRAMs

International Nuclear Information System (INIS)

Yoo, Min Soo; Choi, Kang Sik; Sun, Woo Kyung

2010-01-01

As DRAM cell pitch size decreases, the need for a high performance transistor is increasing. Though saddle-fin (S-fin) transistors have superior characteristics, S-fin transistors are well known to be more sensitive to process variation. To make uniform S-fin transistors, for the first time, we developed a new fin formation method using tilted ion implantation along the wordline direction after a recess gate etch. Due to the increased etch rate of the oxide film by ion implantation damage, fins are made at the bottom channel of the recess gate after wet etching. The resulting tilt implanted saddle-fin (TIS-fin) transistor has remarkably improved characteristics, such as ∼8% subthreshold swing (SS) and a 40% drain induced barrier lowering (DIBL) decrease. Especially, the TIS-fin with a neutral dopant has a reduced threshold voltage (Vth) variation within a wafer (<100 mV), which is comparable with that of a mass-produced sphere-shaped recessed channel array transistor (SRCAT).

Aphanius arakensis, a new species of tooth-carp (Actinopterygii, Cyprinodontidae) from the endorheic Namak Lake basin in Iran

OpenAIRE

Teimori,Azad; Esmaeili,Hamid; Gholami,Zeinab; Zarei,Neda; Reichenbacher,Bettina

2012-01-01

A new species of tooth-carp, Aphanius arakensis sp. n., is described from the Namak Lake basin in Iran. The new species is distinguished by the congeners distributed in Iran by the following combination of characters: 10–12 anal fin rays, 28–32 lateral line scales, 10–13 caudal peduncle scales, 8–10 gill rakers, 12–19, commonly 15–16, clearly defined flank bars in males, a more prominent pigmentation along the flank added by relatively big blotches in the m...

Growth Responses of Fish During Chronic Exposure of Metal Mixture under Laboratory Conditions

Directory of Open Access Journals (Sweden)

Saima Naz and Muhammad Javed

2013-07-01

Full Text Available Growth responses of five fish species viz. Catla catla, Labeo rohita, Cirrhina mrigala, Ctenopharyngodon idella and Hypophthalmichthys molitrix were determined, separately, under chronic exposure of binary mixture of metals (Zn+Ni at sub-lethal concentrations (1/3rd of LC50 for 12 weeks. Randomized complete block design (RCBD was followed to conduct this research work. The groups (10 fish each of Catla catla, Labeo rohita, Cirrhina mrigala, Ctenopharyngodon idella and Hypophthalmichthys molitrix having almost similar weights were investigated for their growth responses and metals bioaccumulation patterns in their body organs during chronic exposure of Zn+Ni mixture. The bioaccumulation of metals in the fish body organs viz. gills, liver, kidney, fins, bones, muscle and skin were also determined before and after growth trails under the stress of metals mixture. The exposure of fish to sub-lethal concentrations of mixture caused significant impacts on the average wet weight increments of five fish species. Ctenopharyngodon idella and Labeo rohita attained significantly higher weights, followed by that of Hypophthalmichthys molitrix, Cirrhina mrigala and Catla catla. However, the growth of metals mixture exposed fish species was significantly lesser than that of control fish (un-stressed. Significantly variable condition factor values reflected the degree of fish well-beings that correlated directly with fish growth and metal exposure concentration. Any significant change in feed intake, due to stress, is reflected in terms of fish growth showing the impacts of metal mixture on fish growth were either additive or antagonist / synergistic. Accumulation of all the metals in fish body followed the general order: liver>kidney>gills> skin >muscle> fins >bones.

Photorepair and excision repair removal of UV-induced pyrimidine dimers and (6-4) photoproducts in the tail fin of the Medaka, Oryzias latipes

International Nuclear Information System (INIS)

Funayama, Tomoo; Mitani, Hiroshi; Shima, Akihiro; Ishigaki, Yasuhito; Matsunaga, Tsukasa; Nikaido, Osamu.

1994-01-01

Induction and repair of UV-B induced DNA damage in the tail fin of the Medaka, were examined immunohistochemically and by the enzyme-linked immunosorbent assay (ELISA). UV-induced DNA damage was detected only in the outermost layer of epithelial cells and did not differ in fishes having different degree of melanization. Both pyrimidine dimers and (6-4) photoproducts in the fin cells were removed by excision repair in the dark, the excision of (6-4) photoproducts being about twice as efficient as that of pyrimidine dimers. The rate of excision repair of UV-induced lesions in fin tissue was three to four times that in cultured Medaka cells, OL32.. In the fin cells, reductions in the numbers of pyrimidine dimers and (6-4) photoproducts were seen after treatment with fluorescent light, whereas less reductions of pyrimidine dimers and no reductions of (6-4) photoproducts were observed in OL32 cells. (author)

Investigation of internally finned LED heat sinks

Science.gov (United States)

Li, Bin; Xiong, Lun; Lai, Chuan; Tang, Yumei

2018-03-01

A novel heat sink is proposed, which is composed of a perforated cylinder and internally arranged fins. Numerical studies are performed on the natural convection heat transfer from internally finned heat sinks; experimental studies are carried out to validate the numerical results. To compare the thermal performances of internally finned heat sinks and externally finned heat sinks, the effects of the overall diameter, overall height, and installation direction on maximum temperature, air flow and heat transfer coefficient are investigated. The results demonstrate that internally finned heat sinks show better thermal performance than externally finned heat sinks; the maximum temperature of internally finned heat sinks decreases by up to 20% compared with the externally finned heat sinks. The existence of a perforated cylinder and the installation direction of the heat sink affect the thermal performance significantly; it is shown that the heat transfer coefficient of the heat sink with the perforated cylinder is improved greater than that with the imperforated cylinder by up to 34%, while reducing the mass of the heat sink by up to 13%. Project supported by the Scientific Research Fund of Sichuan Provincial Education Department (No. 18ZB0516) and the Sichuan University of Arts and Science (No. 2016KZ009Y).

The shark's fin

International Nuclear Information System (INIS)

Listinsky, J.L.; Griffiths, H.J.

1989-01-01

Initial plain film studies of seven patients with facet fracture-dislocations of the cervical spine were examined retrospectively. Rotation of the cross-table lateral film from a standard vetical viewing orientation to a simulated brow-down position allowed easier appreciation of the dislocated pillar in six of the seven patients. The displaced pillar had an appearance similar to that of the dorsal fin of a shark. We conclude that the finding of a shark's fin appearance of an articular pillar in a traumatized patient warrants further radiographic studies. (author). 8 refs.; 3 figs

Room to high temperature measurements of flexible SOI FinFETs with sub-20-nm fins

KAUST Repository

Diab, Amer El Hajj

2014-12-01

We report the temperature dependence of the core electrical parameters and transport characteristics of a flexible version of fin field-effect transistor (FinFET) on silicon-on-insulator (SOI) with sub-20-nm wide fins and high-k/metal gate-stacks. For the first time, we characterize them from room to high temperature (150 °C) to show the impact of temperature variation on drain current, gate leakage current, and transconductance. Variation of extracted parameters, such as low-field mobility, subthreshold swing, threshold voltage, and ON-OFF current characteristics, is reported too. Direct comparison is made to a rigid version of the SOI FinFETs. The mobility degradation with temperature is mainly caused by phonon scattering mechanism. The overall excellent devices performance at high temperature after release is outlined proving the suitability of truly high-performance flexible inorganic electronics with such advanced architecture.

Integrated diversification of locomotion and feeding in labrid fishes.

Science.gov (United States)

Collar, David C; Wainwright, Peter C; Alfaro, Michael E

2008-02-23

An organism's performance of any ecological task involves coordination of multiple functional systems. Feeding performance is influenced by locomotor abilities which are used during search and capture of prey, as well as cranial mechanics, which affect prey capture and processing. But, does this integration of functional systems manifest itself during evolution? We asked whether the locomotor and feeding systems evolved in association in one of the most prominent and diverse reef fish radiations, the Labridae. We examined features of the pectoral fins that affect swimming performance and aspects of the skull that describe force and motion of the jaws. We applied a recent phylogeny, calculated independent contrasts for 60 nodes and performed principal components analyses separately on contrasts for fin and skull traits. The major axes of fin and skull diversification are highly correlated; modifications of the skull to amplify the speed of jaw movements are correlated with changes in the pectoral fins that increase swimming speed, and increases in force capacity of the skull are associated with changes towards fins that produce high thrust at slow speeds. These results indicate that the labrid radiation involved a strong connection between locomotion and feeding abilities.

The prevalence of parasites in ornamental fish from fish market in Medan

Science.gov (United States)

Dewi, R. R.; Desrita; Fadhilla, A.

2018-02-01

Parasites still become the major problem in ornamental fish as the fast grown of its trading in Indonesia. Parasites causes diseases in ornamental fish hence followed by death and reducing its appearence. In this study, the prevalence of parasites in 100 apparently healthy ornamental fishes namely Guppy (Poecilia reticulate) and Goldfish (Carrasius auratus) were determined. The method of this research used was survey in local fish market in Medan from March to May 2017 The aim of this study was to determine the parasite that infects aquarium fishes and find out its prevalence. For this purpose, ornamental fishes were examined for parasites from their skin, fin, gill and intestine using wet mount method under a light microscope. The survey result showed that parasites that infect Guppy and Goldfish were Monogenea (Dactylogyrus sp and Gyrodactylus sp) in their skin and gill, Protozoa (piscinodinium sp) in their gill and Nematoda (Capillaria sp) in abdominal cavity. Prevalence rate of parasites that attack Guppy in Medan is Dactylogyrus sp (8%), Gyrodactylus sp (14 %), Piscinodinium sp (6%) and Capillaria sp (8%). Then, prevalence rate of Capilaria sp that attack Goldfish is 4%. The conclusion of this work revealed that the prevalence rate of ectoparasite and endoparasites in ornamental fishes in Medan had the low rate as well as there was no pathological findings is observed. However, these parasites could be a harmful parasitic diseases in case there is the changes in aquarium environment and improper fish handling.

Parametric CFD Analysis to Study the Influence of Fin Geometry on the Performance of a Fin and Tube Heat Exchanger

DEFF Research Database (Denmark)

Singh, Shobhana; Sørensen, Kim; Condra, Thomas Joseph

2016-01-01

Heat transfer and pressure loss characteristics of a fin and tube heat exchanger are numerically investigated based on parametric fin geometry. The cross-flow type heat exchanger with circular tubes and rectangular fin profile is selected as a reference design. The fin geometry is varied using...... a design aspect ratio as a variable parameter in a range of 0.1-1.0 to predict the impact on overall performance of the heat exchanger. In this paper, geometric profiles with a constant thickness of fin base are studied. Three-dimensional, steady state CFD model is developed using commercially available...... are determined. The best performed geometric fin profile based on the higher heat transfer and lower pressure loss is predicted. The study provides insights into the impact of fin geometry on the heat transfer performance which help escalate the understanding of heat exchanger designing and manufacturing...

Morphology, Kinematics, and Dynamics: The Mechanics of Suction Feeding in Fishes.

Science.gov (United States)

Day, Steven W; Higham, Timothy E; Holzman, Roi; Van Wassenbergh, Sam

2015-07-01

Suction feeding is pervasive among aquatic vertebrates, and our understanding of the functional morphology and biomechanics of suction feeding has recently been advanced by combining experimental and modeling approaches. Key advances include the visualization of the patterns of flow in front of the mouth of a feeding fish, the measurement of pressure inside their mouth cavity, and the employment of analytical and computational models. Here, we review the key components of the morphology and kinematics of the suction-feeding system of anatomically generalized, adult ray-finned fishes, followed by an overview of the hydrodynamics involved. In the suction-feeding apparatus, a strong mechanistic link among morphology, kinematics, and the capture of prey is manifested through the hydrodynamic interactions between the suction flows and solid surfaces (the mouth cavity and the prey). It is therefore a powerful experimental system in which the ecology and evolution of the capture of prey can be studied based on first principals. © The Author 2015. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

Effect of fin pitch and number of tube rows on the air side performance of herringbone wavy fin and tube heat exchangers

International Nuclear Information System (INIS)

Wongwises, Somchai; Chokeman, Yutasak

2005-01-01

An experimental study is conducted to investigate the effects of a fin pitch and number of tube rows on the air side performance of fin and tube heat exchangers having herringbone wavy fin configuration at various fin thicknesses. A total of 10 samples of fin and tube heat exchanger with a tube outside diameter of 9.53mm, transverse tube pitch of 25.4mm and longitudinal tube pitch of 19.05mm, having various fin pitches, number of tube rows and fin thicknesses, are tested in a well insulated open wind tunnel. The heat exchangers are made from aluminium plate finned, copper tube. Ambient air is used as a working fluid in the air side while hot water is used for the tube side. The results are presented as the variation of the Colburn factor and the friction factor with the Reynolds number based on the fin collar outside diameter (Re D c ). The experimental results reveal that the fin pitch has an insignificant effect on the heat transfer characteristic. The friction factor increases with increasing fin pitch when Re D c >2500, approximately. The Colburn factor and the friction factor decrease with increasing number of tube rows when Re D c <4000, approximately. These results remain the same when the fin thickness is changed

Evolution of the branchiostegal membrane and restricted gill openings in Actinopterygian fishes.

Science.gov (United States)

Farina, Stacy C; Near, Thomas J; Bemis, William E

2015-06-01

A phylogenetic survey is a powerful approach for investigating the evolutionary history of a morphological characteristic that has evolved numerous times without obvious functional implications. Restricted gill openings, an extreme modification of the branchiostegal membrane, are an example of such a characteristic. We examine the evolution of branchiostegal membrane morphology and highlight convergent evolution of restricted gill openings. We surveyed specimens from 433 families of actinopterygians for branchiostegal membrane morphology and measured head and body dimensions. We inferred a relaxed molecular clock phylogeny with branch length estimates based on nine nuclear genes sampled from 285 species that include all major lineages of Actinopterygii. We calculated marginal state reconstructions of four branchiostegal membrane conditions and found that restricted gill openings have evolved independently in at least 11 major actinopterygian clades, and the total number of independent origins of the trait is likely much higher. A principal component analysis revealed that fishes with restricted gill openings occupy a larger morphospace, as defined by our linear measurements, than do fishes with nonrestricted openings. We used a decision tree analysis of ecological data to determine if restricted gill openings are linked to certain environments. We found that fishes with restricted gill openings repeatedly occur under a variety of ecological conditions, although they are rare in open-ocean pelagic environments. We also tested seven ratios for their utility in distinguishing between fishes with and without restricted gill openings, and we propose a simple metric for quantifying restricted gill openings (RGO), defined as a ratio of the distance from the ventral midline to the gill opening relative to half the circumference of the head. Functional explanations for this specialized morphology likely differ within each clade, but its repeated evolution indicates a need

Performance of tubes-and plate fins heat exchangers

International Nuclear Information System (INIS)

Rosman, E.C.

1979-11-01

By means of a two-dimensional analysis performance, and using local heat transfer coefficients, the plate fin temperature distribution, the air bulk temperature along the stream path and the fin efficiency can be obtained, for several Reynolds numbers and fin materials. Herein are also presented the average heat transfer coefficients for isothermal plate fins, referring to heat exchangers with central-tube and rear-tube row and to two-row tubes heat exchangers configurations. It is possible to obtain the real tax or the real area of heat transfer, using the average hea transfer coefficients for isothermal plate fins and the fin efficiency. (Author) [pt

Why are there so few fish in the sea?

Science.gov (United States)

Carrete Vega, Greta; Wiens, John J

2012-06-22

The most dramatic gradient in global biodiversity is between marine and terrestrial environments. Terrestrial environments contain approximately 75-85% of all estimated species, but occupy only 30 per cent of the Earth's surface (and only approx. 1-10% by volume), whereas marine environments occupy a larger area and volume, but have a smaller fraction of Earth's estimated diversity. Many hypotheses have been proposed to explain this disparity, but there have been few large-scale quantitative tests. Here, we analyse patterns of diversity in actinopterygian (ray-finned) fishes, the most species-rich clade of marine vertebrates, containing 96 per cent of fish species. Despite the much greater area and productivity of marine environments, actinopterygian richness is similar in freshwater and marine habitats (15 150 versus 14 740 species). Net diversification rates (speciation-extinction) are similar in predominantly freshwater and saltwater clades. Both habitats are dominated by two hyperdiverse but relatively recent clades (Ostariophysi and Percomorpha). Remarkably, trait reconstructions (for both living and fossil taxa) suggest that all extant marine actinopterygians were derived from a freshwater ancestor, indicating a role for ancient extinction in explaining low marine richness. Finally, by analysing an entirely aquatic group, we are able to better sort among potential hypotheses for explaining the paradoxically low diversity of marine environments.

FinFET modeling for IC simulation and design

CERN Document Server

Hu, Chenming; Lu, Darsen D

2015-01-01

This book is the first to explain FinFET modeling for IC simulation and the industry standard - BSIM-CMG - describing the rush in demand for advancing the technology from planar to 3D architecture, as now enabled by the approved industry standard. The book gives a strong foundation on the physics and operation of FinFET, details aspects of the BSIM-CMG model such as surface potential, charge and current calculations, and includes a dedicated chapter on parameter extraction procedures, providing a step-by-step approach for the efficient extraction of model parameters. With this book you will learn: * Why you should use FinFET* The physics and operation of FinFET* Details of the FinFET standard model (BSIM-CMG)* Parameter extraction in BSIM-CMG* FinFET circuit design and simulation * Authored by the lead inventor and developer of FinFET, and developers of the BSIM-CM standard model, providing an experts' insight into the specifications of the standard* The first book on the industry-standard FinFET model - BSIM...

DNA barcoding commercially important fish species of Turkey.

Science.gov (United States)

Keskın, Emre; Atar, Hasan H

2013-09-01

DNA barcoding was used in the identification of 89 commercially important freshwater and marine fish species found in Turkish ichthyofauna. A total of 1765 DNA barcodes using a 654-bp-long fragment of the mitochondrial cytochrome c oxidase subunit I gene were generated for 89 commercially important freshwater and marine fish species found in Turkish ichthyofauna. These species belong to 70 genera, 40 families and 19 orders from class Actinopterygii, and all were associated with a distinct DNA barcode. Nine and 12 of the COI barcode clusters represent the first species records submitted to the BOLD and GenBank databases, respectively. All COI barcodes (except sequences of first species records) were matched with reference sequences of expected species, according to morphological identification. Average nucleotide frequencies of the data set were calculated as T = 29.7%, C = 28.2%, A = 23.6% and G = 18.6%. Average pairwise genetic distance among individuals were estimated as 0.32%, 9.62%, 17,90% and 22.40% for conspecific, congeneric, confamilial and within order, respectively. Kimura 2-parameter genetic distance values were found to increase with taxonomic level. For most of the species analysed in our data set, there is a barcoding gap, and an overlap in the barcoding gap exists for only two genera. Neighbour-joining trees were drawn based on DNA barcodes and all the specimens clustered in agreement with their taxonomic classification at species level. Results of this study supported DNA barcoding as an efficient molecular tool for a better monitoring, conservation and management of fisheries. © 2013 John Wiley & Sons Ltd.

Histopathology of Marine and Freshwater Fish Lymphocytosis Disease Virus (LCDV)

International Nuclear Information System (INIS)

Hossain, M.; Myung-Joo, Oh

2011-01-01

Lymphocytosis disease (LCD) in fishes is caused by the agent called lymphocytosis disease virus (LCDV). LCDV is a chronic and benign virus. The disease affects 96 species of marine and fresh water fishes ranged among 34 families in the world. Affected fish with LCD has a typical external symptom with clusters consisted of enormously hypertrophied dermal cells on the skin and fins. The hypertrophied cells, generally named lymphocytosis cells, have a thick hyaline capsule, an enlarged nucleus and prominent basophilic cytoplasmic inclusions. Among the four species of fishes, olive flounder Paralichthys olivaceus, and rockfish Sebastes schlegeli were marine cultured fish, and gourami Trichogaster leeri and painted glass fish Channa baculis were freshwater ornamental fish. Although LCD causes low mortality, the disfigurement of infected fish can make them unsellable. Thus LCD has resulted in an important economic loss in the aquaculture industry. This study of histopathology may be adequate for a presumptive diagnosis of lymphocytosis diseases both in marine and freshwater fish species. (author)

Design and Fabrication of Soft Morphing Ray Propulsor: Undulator and Oscillator.

Science.gov (United States)

Kim, Hyung-Soo; Lee, Jang-Yeob; Chu, Won-Shik; Ahn, Sung-Hoon

2017-03-01

A soft morphing ray propulsor capable of generating an undulating motion in its pectoral fins was designed and fabricated. The propulsor used shape memory alloy for actuation, and the body was made with soft polymers. To determine the effects of undulation in the fins, two models that differed in terms of the presence of undulation were fabricated using different polymer materials. The experimental models were tested with a dynamometer to measure and compare thrust tendencies. Thrust measurements were conducted with various fin beat frequencies. Using the experimental data, the concept of an optimized standalone version of the ray robot was suggested and its prototype was fabricated. The fabricated robot was able to swim as fast as 0.26 body length per second and 38% more efficient than other smart material-based ray-like underwater robots.

Lionfish predators use flared fin displays to initiate cooperative hunting.

Science.gov (United States)

Lönnstedt, Oona M; Ferrari, Maud C O; Chivers, Douglas P

2014-06-01

Despite considerable study, mystery surrounds the use of signals that initiate cooperative hunting in animals. Using a labyrinth test chamber, we examined whether a lionfish, Dendrochirus zebra, would initiate cooperative hunts with piscine partners. We found that D. zebra uses a stereotyped flared fin display to alert conspecific and heterospecific lionfish species Pterois antennata to the presence of prey. Per capita success rate was significantly higher for cooperative hunters when compared with solitary ones, with hunt responders assisting hunt initiators in cornering the prey using their large extended pectoral fins. The initiators would most often take the first strike at the group of prey, but both hunters would then alternate striking at the remaining prey. Results suggest that the cooperative communication signal may be characteristic to the lionfish family, as interspecific hunters were equally coordinated and successful as intraspecific hunters. Our findings emphasize the complexity of collaborative foraging behaviours in lionfish; the turn-taking in strikes suggests that individuals do not solely try to maximize their own hunting success: instead they equally share the resources between themselves. Communicative group hunting has enabled Pteroine fish to function as highly efficient predators. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Characteristics of fin whale vocalizations recorded on instruments in the northeast Pacific Ocean

Science.gov (United States)

Weirathmueller, Maria Michelle Josephine

This thesis focuses on fin whale vocalizations recorded on ocean bottom seismometers (OBSs) in the Northeast Pacific Ocean, using data collected between 2003 and 2013. OBSs are a valuable, and largely untapped resource for the passive acoustic monitoring of large baleen whales. This dissertation is divided into three parts, each of which uses the recordings of fin whale vocalizations to better understand their calling behaviors and distributions. The first study describes the development of a technique to extract source levels of fin whale vocalizations from OBS recordings. Source levels were estimated using data collected on a network of eight OBSs in the Northeast Pacific Ocean. The acoustic pressure levels measured at the instruments were adjusted for the propagation path between the calling whales and the instruments using the call location and estimating losses along the acoustic travel path. A total of 1241 calls were used to estimate an average source level of 189 +/-5.8 dB re 1uPa 1m. This variability is largely attributed to uncertainties in the horizontal and vertical position of the fin whale at the time of each call, and the effect of these uncertainties on subsequent calculations. The second study describes a semi-automated method for obtaining horizontal ranges to vocalizing fin whales using the timing and relative amplitude of multipath arrivals. A matched filter is used to detect fin whale calls and pick the relative times and amplitudes of multipath arrivals. Ray-based propagation models are used to predict multipath times and amplitudes as function of range. Because the direct and first multiple arrivals are not always observed, three hypotheses for the paths of the observed arrivals are considered; the solution is the hypothesis and range that optimizes the fit to the data. Ray-theoretical amplitudes are not accurate and solutions are improved by determining amplitudes from the observations using a bootstrap method. Data from ocean bottom

Review of the Indo-Pacific labrid fish genus Hemigymnus

OpenAIRE

Randall, John E.

2013-01-01

The labrid fish genus Hemigymnus Günther consists of three relatively large coral-reef species: the wide-ranging Indo-Pacific H. fasciatus (Bloch) and H. melapterus (Bloch), and H. sexfasciatus (Rüppell) of the Red Sea and Gulf of Aden, usually regarded as a synonym of H. fasciatus. It is treated here as a species, distinguished by color pattern, longer pelvic fins of the terminal male, and fewer gill rakers. These three fishes are generally found as solitary individuals over sand or sand-and...

FinTech in Denmark

OpenAIRE

Hategan, Ramona Anamaria; Mockus, Gytis; Trinkunaite, Sarune

2017-01-01

ABSTRACTThe purpose of this paper has been to seek understanding and knowledge of FinTech phenomenon, with a particular focus on the effect of its emergence on the Danish financial sector. We have attempted to answer our initial research question with the help of a theoretical and methodological framework conceived of concepts belonging to Actor-Network Theory, Diffusion of Innovation Theory and alluding to Foucault’s concepts of power, knowledge and discourses. We have followed FinTech as an...

Investigating the effect of non-similar fins in thermoeconomic optimization of plate fin heat exchanger

International Nuclear Information System (INIS)

Hajabdollahi, Hassan

2015-01-01

Thermoeconomic optimization of plate fin heat exchanger with similar (SF) and different (DF) or non-similar fin in each side is presented in this work. For this purpose, both heat exchanger effectiveness and total annual cost (TAC) are optimized simultaneously using multi-objective particle swarm optimization algorithm. The above procedure is performed for various mass flow rates in each side. The optimum results reveal that no thermoeconomic improvement is observed in the case of same mass flow rate in each side while both effectiveness and TAC are improved in the case of different mass flow rate. For example, effectiveness and TAC are improved 0.95% and 10.17% respectively, for the DF compared with SF. In fact, the fin configuration should be selected more compact in a side with lower mass flow rate compared with the other side in the thermoeconomic viewpoint. Furthermore, for the thermodynamic optimization viewpoint both SF and DF have the same optimum result while for the economic (or thermoeconomic) optimization viewpoint, the significant decrease in TAC is accessible in the case of DF compared with SF. - Highlights: • Thermoeconomic modeling of compact heat exchanger. • Selection of fin and heat exchanger geometries as nine decision variables. • Applying MOPSO algorithm for multi objective optimization. • Considering the similar and different fin specification in each side. • Investigation of optimum design parameters for various mass flow rates

Effects of gamma-rays on morphology of the thymus of the adult fish of Oryzias latipes

International Nuclear Information System (INIS)

Ghoneum, M.M.H.; Ijiri, Ken-ichi; Egami, Nobuo

1982-01-01

The effects of gamma-rays on the thymus in the adult fish of Oryzias latipes were studied. Fish were subjected to a single whole-body irradiation of the dose ranging from 0 to 8 kR. Through the histological sections, the quantitative treatment was performed on the changes in thymus volume and mitotic activity of thymocytes after irradiation. The thymus in the irradiated fish exhibited a sudden drop in its volume on day 1-3 post-irradiation, subsequently followed by its regeneration. The change in mitotic index of thymocytes, especially in the regeneration phase, showed a dose-dependent behavior (same level as the control for 10 and 25 R; and overshoot for 100 and 200 R; a gradual recovery for 1 and 2 kR; no mitosis for 4 and 8 kR). (author)

Flexible nanoscale high-performance FinFETs

KAUST Repository

Sevilla, Galo T.

2014-10-28

With the emergence of the Internet of Things (IoT), flexible high-performance nanoscale electronics are more desired. At the moment, FinFET is the most advanced transistor architecture used in the state-of-the-art microprocessors. Therefore, we show a soft-etch based substrate thinning process to transform silicon-on-insulator (SOI) based nanoscale FinFET into flexible FinFET and then conduct comprehensive electrical characterization under various bending conditions to understand its electrical performance. Our study shows that back-etch based substrate thinning process is gentler than traditional abrasive back-grinding process; it can attain ultraflexibility and the electrical characteristics of the flexible nanoscale FinFET show no performance degradation compared to its rigid bulk counterpart indicating its readiness to be used for flexible high-performance electronics.

The first record of a frogfish, Fowlerichthys scriptissimus (Antennariidae, Lophiiformes, from Korea

Directory of Open Access Journals (Sweden)

Song-Hun Han

2017-02-01

Full Text Available Abstract This is the first report of Fowlerichthys scriptissimus (Lophiiformes, Antennariidae from Korea. A single specimen (291.0 mm SL was collected off the coast of Jejudo Island by gill net on 28 March 2012 and identified with morphological and molecular approaches. The specimen is characterized by having all five pelvic fin rays bifurcate and possessing 20 vertebrae, 13 pectoral-fin rays, and a basidorsal ocellus on the side of the body. This species is distinguishable from other Korean taxa by the number of pectoral fin rays, the bifurcate form of the pelvic rays, and the vertebral count. We add this species to the Korean fish fauna and suggest new Korean names, “Byeol-ssin-beng-i-sok” and “Byeol-ssin-beng-i” for the genus and species, respectively.

Ultrastructural study of the effect of heavy metals on the regenerating tail fin of the teleost fish, Oreochromis niloticus

Directory of Open Access Journals (Sweden)

K.I. Atta

2012-08-01

In the tail fins of the specimens treated with Pb at 0.005 and 0.025 mg/l and Cd at 0.005 and 0.025 mg/l, at the seventh day postamputation, the lepidotrichia forming cells have dense patches of irregular lysosomes, swollen and degranulated rough endoplasmic reticulum, pyknotic mitochondria and vacuolated cytoplasm. In the tail fins of the specimens treated with Hg at 0.0006 mg/l, showed deformation of the lepidotrichia forming cells, there was an invasion of leucocytes and lysosomes. A progressive damage in the cytoplasmic organelles and in the fiber bundles of bones was also found. Also, the presence of collagen fibers as pathological condition.

Implications of fin profiles on overall performance and weight reduction of a fin and tube heat exchanger

DEFF Research Database (Denmark)

Singh, Shobhana; Sørensen, Kim; Simonsen, Anders Schou

2017-01-01

Fin and tube heat exchangers are being used in several industrial applications by means of novel design and optimized performance. Improvements in geometric design may deliver energy efficient and cost-effective heat exchanger performance with reduced weight. In this paper, a systematic study...... on a cross-flow type fin and tube heat exchanger design for a waste heat recovery application is conducted. The geometric profile of the fin is characterized by a dimensionless design variable named aspect ratio which is parametrically varied to obtain different profiles. Two cases, case-I, and case......,000 using computational fluid dynamics. The numerical results obtained for the reference fin profile are verified with the experimental correlations. Dimensionless parameters such as Nusselt number, Euler number, and efficiency index are calculated to predict the overall performance of the heat exchanger...

FinTech in Taiwan: a case study of a Bank's strategic planning for an investment in a FinTech company

OpenAIRE

Hung, Jui-long; Luo, Binjie

2016-01-01

Introduction: Since 2015 is the year of FinTech in Taiwan, it is worth investigating the challenges that emerged when banks were encouraged to invest in FinTech companies for collaboration. This study aims to identify the strategic considerations in the process of searching for FinTech investment targets. Case description: This study used a case study investigation of a top-5 bank in Taiwan. The major data sources include the meeting notes of the FinTech investment task force and interviews w...

A new species of the genus Salaria Forsskål, 1775 (Actinopterygii, Blennidae in Morocco

Directory of Open Access Journals (Sweden)

Yahyaoui, A.

2011-12-01

Full Text Available The North African freshwater fish fauna is scarce compared to other regions of the world, probably due to historical and climatic factors. The western part of North Africa is more diverse than central or eastern areas. Populations of freshwater blennids that have been traditionally ascribed to the species Salaria fluviatilis nowadays inhabit the Sebou basin in Morocco. In this study we demonstrated morphologically and molecularly that these Moroccan populations constitute a new species, for which we provide a formal description. The following diagnostic characters distinguish the newly described species from other freshwater blennids: head without diagonal rows of dark dots or blotches on cheeks; supra-ocular tentacle thick and simple (not branched; 13-15 teeth on the upper jaw and 14-16 on the lower jaw; 16-17 soft anal fin rays; short pre-orbital distance (cephalic index: 2.9-3.8; height of the anterior (spiny part of the dorsal fin short (dorsal fin index: 0.8-1.3 and 34 vertebrae. Mitochondrial and nuclear genetic distances between the new Salaria species and either S. economidisi or S. fluviatilis are high, especially in the mitochondrial control region (18%, while these genetic distances range from 2 to 3% when the nuclear S7 marker is compared. These morphological and molecular characters differentiate the new species from the remaining freshwater species of the genus (Salaria economidisi and S. fluviatilis. The new species is confined to a small restricted area of the Sebou basin in Morocco and should be considered endangered (EN according to the IUCN Red List.La fauna de peces de agua dulce del norte de África es escasa comparada con otras regiones del mundo debido fundamentalmente a factores históricos y climáticos. El oeste del norte de África es más diverso que las regiones del centro y del este. En la cuenca del río Sebou habitan actualmente poblaciones de blenios de agua dulce que han sido tradicionalmente adscritas a la

A NEW SAURICHTHYS (ACTINOPTERYGII FROM THE SPATHIAN (EARLY TRIASSIC OF CHAOHU (ANHUI PROVINCE, CHINA

Directory of Open Access Journals (Sweden)

ANDREA TINTORI

2014-07-01

Full Text Available A new species of Saurichthys, S. majiashanensis , is described. It comes from a series of marine vertebrate-bearing beds of the upper member of the Nanlinghu Formation outcropping in the large quarry at the top of Majiashan (Majia Hill near Chaohu (Hefei City, Anhui Province, China. Its age is Middle Spathian (Olenekian, Early Triassic. This new species deeply differs from the several pre-Spathian species of Saurichthys mainly for having only two longitudinal scale rows together with a reduced grid-like structure for the neural elements in the vertebral column. Further derived characters are in the endoskeleton of the dorsal and anal fin, where radials articulate only to anterior lepidotrichia, the posterior ones being supported by the first scale from the caudal pedicle mid-dorsal and mid-ventral rows, deeply imbedded in the body. In addition, the haemal spines of the caudal region are much enlarged and reversed, with their distal parts pointing forwards. Though the skull is lacking, postcranial characters are enough to justify the erection of a new species. This new Saurichthys species, together with other few actinopterygians, can be considered as the oldest assemblage of the Triassic Middle Fish Fauna, which bloomed probably in the early Anisian and widespread especially all over the Tethys for the Middle Triassic and at least the Carnian in the Late Triassic. This new fish assemblage, together with some of the oldest marine reptiles, is considered as the beginning of the actual Triassic recovery among marine vertebrates.

Modelling of a biologically inspired robotic fish driven by compliant parts

International Nuclear Information System (INIS)

Daou, Hadi El; Salumäe, Taavi; Kruusmaa, Maarja; Chambers, Lily D; Megill, William M

2014-01-01

Inspired by biological swimmers such as fish, a robot composed of a rigid head, a compliant body and a rigid caudal fin was built. It has the geometrical properties of a subcarangiform swimmer of the same size. The head houses a servo-motor which actuates the compliant body and the caudal fin. It achieves this by applying a concentrated moment on a point near the compliant body base. In this paper, the dynamics of the compliant body driving the robotic fish is modelled and experimentally validated. Lighthill’s elongated body theory is used to define the hydrodynamic forces on the compliant part and Rayleigh proportional damping is used to model damping. Based on the assumed modes method, an energetic approach is used to write the equations of motion of the compliant body and to compute the relationship between the applied moment and the resulting lateral deflections. Experiments on the compliant body were carried out to validate the model predictions. The results showed that a good match was achieved between the measured and predicted deformations. A discussion of the swimming motions between the real fish and the robot is presented. (paper)

Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Pacific Southwest). Chinook Salmon.

Science.gov (United States)

1986-04-01

fin is moderately forked; America are distributed from the adipose is stout and prominent; a Sacramento-San Joaquin River system free- tipoed flesh...downstream. Joaquin Rivers to spawn in 1953-83 The completed nest forms an oval de - (data from Taylor 1974; Reavis 1983; pression with a mound of gravel...warmwater fish produc- of engineering requirements and bio- tion and costs . Calif. Dep. Fish logical criteria. U.S. Army Corps Game, Inland Fish

The role of HoxA11 and HoxA13 in the evolution of novel fin morphologies in a representative batoid (Leucoraja erinacea

Directory of Open Access Journals (Sweden)

Shannon N. Barry

2017-12-01

Full Text Available Abstract Background Batoids exhibit unique body plans with derived fin morphologies, such as the anteriorly expanded pectoral fins that fuse to the head, or distally extended anterior pelvic fin lobes used for a modified swimming technique utilized by skates (Rajidae. The little skate (Leucoraja erinacea, exhibits both of these unique fin morphologies. These fin modifications are not present in a typical shark body plan, and little is known regarding the mechanisms underlying their development. A recent study identified a novel apical ectodermal ridge (AER associated with the development of the anterior pectoral fin in the little skate, but the role of the posterior HoxA genes was not featured during skate fin development. Results We present the first evidence for HoxA expression (HoxA11 and HoxA13 in novel AER domains associated with the development of three novel fin morphologies in a representative batoid, L. erinacea. We found HoxA13 expression associated with the recently described novel AER in the anterior pectoral fin, and HoxA11 expression in a novel AER domain in the anterior pelvic fin that we describe here. We find that both HoxA11 and HoxA13 are expressed in claspers, and while HoxA11 is expressed in pelvic fins and claspers, HoxA13 is expressed exclusively in developing claspers of males. Finally, HoxA11 expression is associated with the developing fin rays in paired fins. Conclusion Overall, these results indicate that the posterior HoxA genes play an important role in the morphological evolution of paired fins in a representative batoid. These data suggest that the batoids utilize a unique Hox code, where the posterior HoxA genes exhibit distinct expression patterns that are likely associated with specification of novel fin morphologies.

Strain relaxation of germanium-tin (GeSn) fins

Science.gov (United States)

Kang, Yuye; Huang, Yi-Chiau; Lee, Kwang Hong; Bao, Shuyu; Wang, Wei; Lei, Dian; Masudy-Panah, Saeid; Dong, Yuan; Wu, Ying; Xu, Shengqiang; Tan, Chuan Seng; Gong, Xiao; Yeo, Yee-Chia

2018-02-01

Strain relaxation of biaxially strained Ge1-xSnx layer when it is patterned into Ge1-xSnx fin structures is studied. Ge1-xSnx-on-insulator (GeSnOI) substrate was realized using a direct wafer bonding (DWB) technique and Ge1-xSnx fin structures were formed by electron beam lithography (EBL) patterning and dry etching. The strain in the Ge1-xSnx fins having fin widths (WFin) ranging from 1 μm down to 80 nm was characterized using micro-Raman spectroscopy. Raman measurements show that the strain relaxation increases with decreasing WFin. Finite element (FE) simulation shows that the strain component in the transverse direction relaxes with decreasing WFin, while the strain component along the fin direction remains unchanged. For various Ge1-xSnx fin widths, transverse strain relaxation was further extracted using micro-Raman spectroscopy, which is consistent with the simulation results.

Development of a real-time PCR method coupled with a selective pre-enrichment step for quantification of Morganella morganii and Morganella psychrotolerans in fish products

DEFF Research Database (Denmark)

Podeur, Gaetan; Dalgaard, Paw; Leroi, Francoise

2015-01-01

Histamine fish poisoning is common and due to toxic concentrations of histamine often produced by Gram-negative bacteria in fin-fish products with a high content of the free amino acid histidine. The genus Morganella includes two species previously reported to cause incidents of histamine fish po...

Steady-state and transient heat transfer through fins of complex geometry

Directory of Open Access Journals (Sweden)

Taler Dawid

2014-06-01

Full Text Available Various methods for steady-state and transient analysis of temperature distribution and efficiency of continuous-plate fins are presented. For a constant heat transfer coefficient over the fin surface, the plate fin can be divided into imaginary rectangular or hexangular fins. At first approximate methods for determining the steady-state fin efficiency like the method of equivalent circular fin and the sector method are discussed. When the fin geometry is complex, thus transient temperature distribution and fin efficiency can be determined using numerical methods. A numerical method for transient analysis of fins with complex geometry is developed. Transient temperature distributions in continuous fins attached to oval tubes is computed using the finite volume - finite element methods. The developed method can be used in the transient analysis of compact heat exchangers to calculate correctly the heat flow rate transferred from the finned tubes to the fluid.

Swimbladder on Fish Target Strength

Directory of Open Access Journals (Sweden)

Sunardi

2008-08-01

Full Text Available This paper discusses of target strength (TS for the Selar boops (Oxeye scad and Megalaspis cordyla (Torpedo scad, the most commercially fish in Malaysia. TS can be determined from in situ measurements and acoustic calculation of fish model. TS value, depth, and position (x-y-z of targeted fish can be viewed from echogram using FQ-80 Analyzer by in situ measurement. X-ray imaged can be deployed to develop the acoustic fish model. The percentage of length and upper surface area for swimbladder to body fish of Selar boops more than Megalaspis cordyla can be measured after X-ray process. The percentage of width and volume of swimbladders to its each body are no significantly difference for both fish. These data of swimbladder physic support the result of in situ measurement which TS of Megalaspis cordyla stronger Selar boops.

Hydrodynamic determination of the moving direction of an artificial fin by a harbour seal (Phoca vitulina).

Science.gov (United States)

Wieskotten, S; Dehnhardt, G; Mauck, B; Miersch, L; Hanke, W

2010-07-01

Harbour seals can use their vibrissal system to detect and follow hydrodynamic trails left by moving objects. In this study we determined the maximum time after which a harbour seal could indicate the moving direction of an artificial fish tail and analysed the hydrodynamic parameters allowing the discrimination. Hydrodynamic trails were generated using a fin-like paddle moving from left to right or from right to left in the calm water of an experimental box. The blindfolded seal was able to recognise the direction of the paddle movement when the hydrodynamic trail was up to 35 s old. Particle Image Velocimetry (PIV) revealed that the seal might have perceived and used two different hydrodynamic parameters to determine the moving direction of the fin-like paddle. The structure and spatial arrangement of the vortices in the hydrodynamic trail and high water velocities between two counter-rotating vortices are characteristic of the movement direction and are within the sensory range of the seal.

Open Channel Natural Convection Heat Transfer on a Vertical Finned Plate

International Nuclear Information System (INIS)

Park, Joo Hyun; Heo, Jeong Hwan; Chung, Bum Jin

2013-01-01

The natural convection heat transfer of vertical plate fin was investigated experimentally. Heat transfer systems were replaced by mass-transfer systems, based on the analogy concept. The experimental results lie within the predictions of the existing heat transfer correlations of plate-fin for the natural convections. An overlapped thermal boundary layers caused increasing heat transfer, and an overlapped momentum boundary layers caused decreasing heat transfer. As the fin height increases, heat transfer was enhanced due to increased inflow from the open side of the fin spacing. When fin spacing and fin height are large, heat transfer was unaffected by the fin spacing and fin height. Passive cooling by natural convection becomes more and more important for the nuclear systems as the station black out really happened at the Fukushima NPPs. In the RCCS (Reactor Cavity Cooling System) of a VHTR (Very High Temperature Reactor), natural convection cooling through duct system is adopted. In response to the stack failure event, extra cooling capacity adopting the fin array has to be investigated. The finned plate increases the surface area and the heat transfer increases. However, the plate of fin arrays may increase the pressure drop and the heat transfer decreases. Therefore, in order to enhance the passive cooling with fin arrays, the parameters for the fin arrays should be optimized. According to Welling and Wooldridge, a natural convection on vertical plate fin is function of Gr, Pr, L, t, S, and H. The present work investigated the natural convection heat transfer of a vertical finned plate with varying the fin height and the fin spacing. In order achieve high Rayleigh numbers, an electroplating system was employed and the mass transfer rates were measured using a copper sulfate electroplating system based on the analogy concept

Plate-fin array cooling using a finger-like piezoelectric fan

International Nuclear Information System (INIS)

Shyu, Jin-Cherng; Syu, Jhih-Zong

2014-01-01

In this study, the heat transfer of a plate-fin array cooled by a vibrating finger-like piezoelectric fan comprising four flexible rectangular blades was investigated. The results indicated that the heat transfer enhancement of the fin array cooled by a vibrating piezoelectric fan at x/L = 0.5 and H = 5 mm ranged between 1.5 and 3.3, regardless of the fin array orientation. However, the heat transfer enhancement caused by a fan being placed at either edge of the fin array yielded a dissimilar result between both of the fin array orientations because of the superimposed effects of the boundary layer development and the air flow induced by the fan. This dissimilarity was especially noticeable when the piezoelectric fan was composed of aluminum blades to accommodate the moderate Reynolds number. In addition to the Reynolds number, the ratio of the fan blade vibration envelope to the source area determined the Nu number of the piezoelectric fan-cooled fin array. This design enhanced the fin array heat transfer and reduced cooler volume by embedding multiple vibrating beams into the fin array. -- Highlights: • Heat transfer of a piezoelectric fan-cooled plate-fin array was investigated. • Effects of fan position, fan height and fan material on heat transfer were examined. • Similar heat transfer enhancement range was shown for both fin array orientations. • Fin heat transfer with a running Al fan at x = 0 was higher than that at x = 0.25L. • Besides fan Reynolds number, the area ratio also determined Nu of the fin array

On the hydrodynamics of archer fish jumping out of the water: Integrating experiments with numerical simulations

Science.gov (United States)

Sotiropoulos, Fotis; Angelidis, Dionysios; Mendelson, Leah; Techet, Alexandra

2017-11-01

Evolution has enabled fish to develop a range of thrust producing mechanisms to allow skillful movement and give them the ability to catch prey or avoid danger. Several experimental and numerical studies have been performed to investigate how complex maneuvers are executed and develop bioinspired strategies for aquatic robot design. We will discuss recent numerical advances toward the development of a computational framework for performing turbulent, two-phase flow, fluid-structure-interaction (FSI) simulations to investigate the dynamics of aquatic jumpers. We will also discuss the integration of such numerics with high-speed imaging and particle image velocimetry data to reconstruct anatomic fish models and prescribe realistic kinematics of fish motion. The capabilities of our method will be illustrated by applying it to simulate the motion of a small scale archer fish jumping out of the water to capture prey. We will discuss the rich vortex dynamics emerging during the hovering, rapid upward and gliding phases. The simulations will elucidate the thrust production mechanisms by the movement of the pectoral and anal fins and we will show that the fins significantly contribute to the rapid acceleration.

Collision recognition and direction changes for small scale fish robots by acceleration sensors

Science.gov (United States)

Na, Seung Y.; Shin, Daejung; Kim, Jin Y.; Lee, Bae-Ho

2005-05-01

Typical obstacles are walls, rocks, water plants and other nearby robots for a group of small scale fish robots and submersibles that have been constructed in our lab. Sonar sensors are not employed to make the robot structure simple enough. All of circuits, sensors and processor cards are contained in a box of 9 x 7 x 4 cm dimension except motors, fins and external covers. Therefore, image processing results are applied to avoid collisions. However, it is useful only when the obstacles are located far enough to give images processing time for detecting them. Otherwise, acceleration sensors are used to detect collision immediately after it happens. Two of 2-axes acceleration sensors are employed to measure the three components of collision angles, collision magnitudes, and the angles of robot propulsion. These data are integrated to calculate the amount of propulsion direction change. The angle of a collision incident upon an obstacle is the fundamental value to obtain a direction change needed to design a following path. But there is a significant amount of noise due to a caudal fin motor. Because caudal fin provides the main propulsion for a fish robot, there is a periodic swinging noise at the head of a robot. This noise provides a random acceleration effect on the measured acceleration data at the collision. We propose an algorithm which shows that the MEMS-type accelerometers are very effective to provide information for direction changes in spite of the intrinsic noise after the small scale fish robots have made obstacle collision.

A note on the heat transfer in convective fins

International Nuclear Information System (INIS)

Razelos, P.

1979-01-01

In this paper a generalized approach to the problem of heat transfer through convective fins is given. The proper dimensionless variables, which specify the general problem are identified, and upper bounds of the values of the dimensionless number Nsub(r) defined as 'the ratio of the heat transferred by the fin to that of the corresponding bare surface' are derived. It was shown that these limiting values of the Nsub(r) are 1/√B 1 and √2/B 1 for longitudinal fins and spines respectively, where B 1 is the Biot number hb/k, while for annular fins of constant thickness and hyperbolic profile, Nsub(r) 1 , where K(β) is a number determined by the profile of the fin and the ratio β = x 2 /x 1 of the outside to the inside radii. It was also shown that for longitudinal fins and spinces the possible adverse insulating effect by the use of the fin is avoided, if one selects the value of √hA/kC [de

Criteria for analysis and optimization of longitudinal fins with convective tip

International Nuclear Information System (INIS)

Gomes, E.S.

1983-01-01

The problem of heat transfer in longitudinal fins with the main geometries used in equipaments of heat transfer by convection is analyzed. The equation of energy is solved analytically of several geometries fins, with unidimensional formulation, through the use of the convective heat transfer coefficient. The problem of fin optimization is approached analytically yielding the parameters which allow the maximum heat transfer for each particular material waste in the fin. The use of the insulated tip model suggests the use of fins and its optimization for any Biot number of the fin. The use of the convective tip model allows us to determine when is vantageous or disadvantageous to use fins and when fin optimization is possible according to the value of the Biot number and to a convection parameter on the fin tip. (Author) [pt

Resolving shifting patterns of muscle energy use in swimming fish.

Directory of Open Access Journals (Sweden)

Shannon P Gerry

Full Text Available Muscle metabolism dominates the energy costs of locomotion. Although in vivo measures of muscle strain, activity and force can indicate mechanical function, similar muscle-level measures of energy use are challenging to obtain. Without this information locomotor systems are essentially a black box in terms of the distribution of metabolic energy. Although in situ measurements of muscle metabolism are not practical in multiple muscles, the rate of blood flow to skeletal muscle tissue can be used as a proxy for aerobic metabolism, allowing the cost of particular muscle functions to be estimated. Axial, undulatory swimming is one of the most common modes of vertebrate locomotion. In fish, segmented myotomal muscles are the primary power source, driving undulations of the body axis that transfer momentum to the water. Multiple fins and the associated fin muscles also contribute to thrust production, and stabilization and control of the swimming trajectory. We have used blood flow tracers in swimming rainbow trout (Oncorhynchus mykiss to estimate the regional distribution of energy use across the myotomal and fin muscle groups to reveal the functional distribution of metabolic energy use within a swimming animal for the first time. Energy use by the myotomal muscle increased with speed to meet thrust requirements, particularly in posterior myotomes where muscle power outputs are greatest. At low speeds, there was high fin muscle energy use, consistent with active stability control. As speed increased, and fins were adducted, overall fin muscle energy use declined, except in the caudal fin muscles where active fin stiffening is required to maintain power transfer to the wake. The present data were obtained under steady-state conditions which rarely apply in natural, physical environments. This approach also has potential to reveal the mechanical factors that underlie changes in locomotor cost associated with movement through unsteady flow regimes.

Resolving Shifting Patterns of Muscle Energy Use in Swimming Fish

Science.gov (United States)

Gerry, Shannon P.; Ellerby, David J.

2014-01-01

Muscle metabolism dominates the energy costs of locomotion. Although in vivo measures of muscle strain, activity and force can indicate mechanical function, similar muscle-level measures of energy use are challenging to obtain. Without this information locomotor systems are essentially a black box in terms of the distribution of metabolic energy. Although in situ measurements of muscle metabolism are not practical in multiple muscles, the rate of blood flow to skeletal muscle tissue can be used as a proxy for aerobic metabolism, allowing the cost of particular muscle functions to be estimated. Axial, undulatory swimming is one of the most common modes of vertebrate locomotion. In fish, segmented myotomal muscles are the primary power source, driving undulations of the body axis that transfer momentum to the water. Multiple fins and the associated fin muscles also contribute to thrust production, and stabilization and control of the swimming trajectory. We have used blood flow tracers in swimming rainbow trout (Oncorhynchus mykiss) to estimate the regional distribution of energy use across the myotomal and fin muscle groups to reveal the functional distribution of metabolic energy use within a swimming animal for the first time. Energy use by the myotomal muscle increased with speed to meet thrust requirements, particularly in posterior myotomes where muscle power outputs are greatest. At low speeds, there was high fin muscle energy use, consistent with active stability control. As speed increased, and fins were adducted, overall fin muscle energy use declined, except in the caudal fin muscles where active fin stiffening is required to maintain power transfer to the wake. The present data were obtained under steady-state conditions which rarely apply in natural, physical environments. This approach also has potential to reveal the mechanical factors that underlie changes in locomotor cost associated with movement through unsteady flow regimes. PMID:25165858

Coastal rocky reef fishes of Santa Catarina's northern islands, Brazil

Directory of Open Access Journals (Sweden)

Johnatas Adelir Alves

2015-11-01

Full Text Available The coast of the state of Santa Catarina only has non-biogenic reefs, i.e. rocky and artificial reefs, and is considered the geographic south limit for many reef fish species. At present the diversity of organisms associated with reef environments is threatened. This study aimed to record the number of families and species of reef fish fauna of the north coast of the state of Santa Catarina. The data were collected through underwater visual census performed on Graças archipelago (26°12'S /48º29'W, Tamboretes archipelago (26°22'S/48°31'W and Barra do Sul islands (26°27'S/48º35'W. A total of 166 species was observed (6 elasmobranchii and 160 actinopterygii belonging to 66 families. The families with more species richness were Carangidae (16, Epinephelidae (9, Blenidae (8, Serranidae (7, Haemulidae (6, Sparidae (6 Tetraodontidae (6, Labridae-Scarini (5, Labrisomidae (5 Pomacentridae (5, Lutjanidae (5 and Muraenidae (5. This study add to the current published list, new 115 species, including new occurrences (e.g. Chromis limbata, and some endemic (e.g. Sparisoma amplum, exotic (e.g. Omobranchus punctatus, endangered (e.g. Hippocampus erectus and overexploited (e.g. Lutjanus analis species. Twenty one species are present in the IUCN’s list, twelve in the IBAMA’s list and four in the local list. All elasmobranchii recorded here are considered threatened species, like the brazilian guitarfish (Rhinobatos horkelii, which appears in three red lists, and it is considered critically endangered. All species of Epinephelidae are mentioned in the list of risk categories of the IUCN and five are cited as overexploited or threatened with overexploitation by IBAMA. Among Epinephelidae, the goliath grouper (Epinephelus itajara, is present in all red lists and has specific protection rules in Brazil. The gathered information will allow to take appropriate conservation measures, such as the establishment of marine protected areas, monitoring of fishing

3D modeling of dual-gate FinFET.

Science.gov (United States)

Mil'shtein, Samson; Devarakonda, Lalitha; Zanchi, Brian; Palma, John

2012-11-13

The tendency to have better control of the flow of electrons in a channel of field-effect transistors (FETs) did lead to the design of two gates in junction field-effect transistors, field plates in a variety of metal semiconductor field-effect transistors and high electron mobility transistors, and finally a gate wrapping around three sides of a narrow fin-shaped channel in a FinFET. With the enhanced control, performance trends of all FETs are still challenged by carrier mobility dependence on the strengths of the electrical field along the channel. However, in cases when the ratio of FinFET volume to its surface dramatically decreases, one should carefully consider the surface boundary conditions of the device. Moreover, the inherent non-planar nature of a FinFET demands 3D modeling for accurate analysis of the device performance. Using the Silvaco modeling tool with quantization effects, we modeled a physical FinFET described in the work of Hisamoto et al. (IEEE Tran. Elec. Devices 47:12, 2000) in 3D. We compared it with a 2D model of the same device. We demonstrated that 3D modeling produces more accurate results. As 3D modeling results came close to experimental measurements, we made the next step of the study by designing a dual-gate FinFET biased at Vg1 >Vg2. It is shown that the dual-gate FinFET carries higher transconductance than the single-gate device.

Constructal design of finned tubes used in air-cooled heat exchangers

Energy Technology Data Exchange (ETDEWEB)

Shokouhmand, Hossein; Mahjoub, Shoeib [University of Tehran, Tehran (Iran, Islamic Republic of); Salimpour, Mohammad Reza [Isfahan University of Technology, Isfahan (Iran, Islamic Republic of)

2014-06-15

The present study documents the constructal design and optimization of finned tubes used in air-cooled heat exchangers. The considered tubes are equipped with annular fins. The aim is to minimize the overall thermal resistance by morphing the geometry. The geometrical and thermo-physical parameters considered are the number of fins, ratio of fin height to tube diameter, Stanton number, ratio of fin conductivity to air conductivity, ratio of in-tube fluid conductivity to air conductivity and dimensionless pressure drop. Two constraints are applied in the optimization process: fixed overall volume of heat exchanger and fixed volume fraction of fin material. It is found that there exist optimal values for the number and the height of fins. Moreover, the optimal heat transfer has an extremum in a special volume fraction of fin material.

Constructal design of finned tubes used in air-cooled heat exchangers

International Nuclear Information System (INIS)

Shokouhmand, Hossein; Mahjoub, Shoeib; Salimpour, Mohammad Reza

2014-01-01

The present study documents the constructal design and optimization of finned tubes used in air-cooled heat exchangers. The considered tubes are equipped with annular fins. The aim is to minimize the overall thermal resistance by morphing the geometry. The geometrical and thermo-physical parameters considered are the number of fins, ratio of fin height to tube diameter, Stanton number, ratio of fin conductivity to air conductivity, ratio of in-tube fluid conductivity to air conductivity and dimensionless pressure drop. Two constraints are applied in the optimization process: fixed overall volume of heat exchanger and fixed volume fraction of fin material. It is found that there exist optimal values for the number and the height of fins. Moreover, the optimal heat transfer has an extremum in a special volume fraction of fin material.

Computational thermal analysis of cylindrical fin design parameters and a new methodology for defining fin structure in LED automobile headlamp cooling applications

International Nuclear Information System (INIS)

Sökmen, Kemal Furkan; Yürüklü, Emrah; Yamankaradeniz, Nurettin

2016-01-01

Highlights: • In the study, cooling of LED headlamps in automotive is investigated. • The study is based on free convection cooling of LED module. • Besides free convection, Monte Carlo model is used as radiation model as well. • A new algorithm is presented for designing optimum fin structure. • Suggested algorithm for optimum design is verified by various simulations. - Abstract: In this study, the effects of fin design, fin material, and free and forced convection on junction temperature in automotive headlamp cooling applications of LED lights are researched by using ANSYS CFX 14 software. Furthermore a new methodology is presented for defining the optimum cylindrical fin structure within the given limits. For measuring the performance of methodology, analyses are carried out for various ambient temperatures (25 °C, 50 °C and 80 °C) and different LED power dissipations (0.5 W, 0.75 W, 1 W and 1.25 W). Then, analyses are repeated at different heat transfer coefficients and different fin materials in order to calculate LED junction temperature in order to see if the fin structure proposed by the methodology is appropriate for staying below the given safety temperature limit. As a result, the suggested method has always proposed proper fin structures with optimum characteristics for given LED designs. As another result, for safe junction temperature ranges, it is seen that for all LED power dissipations, adding aluminum or copper plate behind the printed circuit board at low ambient temperatures is sufficient. Also, as the ambient temperature increases, especially in high powered LED lights, addition of aluminum is not sufficient and fin usage becomes essential. High heat transfer coefficient and using copper fin affect the junction temperature positively.

Heat transfer enhancement for fin-tube heat exchanger using vortex generators

International Nuclear Information System (INIS)

Yoo, Seong Yeon; Park, Dong Seong; Chung, Min Ho; Lee, Sang Yun

2002-01-01

Vortex generators are fabricated on the fin surface of a fin-tube heat exchanger to augment the convective heat transfer. In addition to horseshoe vortices formed naturally around the tube of the fin-tube heat exchanger, longitudinal vortices are artificially created on the fin surface by vortex generators. The purpose of this study is to investigate the local heat transfer phenomena in the fin-tube heat exchangers with and without vortex generators, and to evaluate the effect of vortices on the heat transfer enhancement. Naphthalene sublimation technique is employed to measure local mass transfer coefficients, then analogy equation between heat and mass transfer is used to calculate heat transfer coefficients. Experiments are performed for the model of fin-circular tube heat exchangers with and without vortex generators, and of fin-flat tube heat exchangers with and without vortex generators. Average heat transfer coefficients of fin-flat tube heat exchanger without vortex generator are much lower than those of fin-circular tube heat exchanger. On the other hand, fin-flat tube heat exchanger with vortex generators has much higher heat transfer value than conventional fin-circular tube heat exchanger. At the same time, pressure losses for four types of heat exchanger is measured and compared

Numerical study of an innovative design of a finned double-pipe heat exchanger with variable fin-tip thickness

International Nuclear Information System (INIS)

Syed, K.S.; Ishaq, Muhammad; Iqbal, Zafar; Hassan, Ahmad

2015-01-01

Highlights: • Variable fin tip angle significantly effect the velocity and temperature distribution. • Significant gain in the thermal performance with decrease in the friction factor. • Variable fin tip angle must be considered an important parameter in designing finned annulus. - Abstract: The analysis of fully developed laminar convective heat transfer in an innovate design of a finned double-pipe heat exchanger (DPHE) with longitudinal fins of variable thickness of the tip subjected to the constant heat transfer rate boundary conditions is investigated here. The tip thickness is controlled by the ratio of tip to base angles as a parameter whose values varying from 0 to 1 correspond to the fin shapes varying from the triangular to the rectangular cross-section. Upto the knowledge of the authors, this parameter is being introduced for the first time in the literature. Discontinuous Galerkin finite element method (DG-FEM) has been employed in the present work. The overall performance of the proposed DPHE has been investigated by considering the friction factor, the Nusselt number and the j-factor. Upto 178% gain in the Nusselt number and 89% gain in the j-factor have been achieved relative to the rectangular cross-section. Such gains relative to the triangular cross-section are respectively 9.5% and 19%. The results indicate that the newly introduced parameter the ratio of tip to base angles has proved to play significant role in the design of a double-pipe heat exchanger in reducing the cost, weight and frictional loss, in improving the heat transfer rate and making the exchanger energy-efficient. Therefore, it must be considered as an important design parameter for heat exchanger design

High performance flexible CMOS SOI FinFETs

KAUST Repository

Fahad, Hossain M.; Sevilla, Galo T.; Ghoneim, Mohamed T.; Hussain, Muhammad Mustafa

2014-01-01

We demonstrate the first ever CMOS compatible soft etch back based high performance flexible CMOS SOI FinFETs. The move from planar to non-planar FinFETs has enabled continued scaling down to the 14 nm technology node. This has been possible due

Caudal fin allometry in the white shark Carcharodon carcharias: implications for locomotory performance and ecology

Science.gov (United States)

Lingham-Soliar, Theagarten

2005-05-01

Allometric scaling analysis was employed to investigate the consequences of size evolution on hydrodynamic performance and ecology in the white shark Carcharodon carcharias. Discriminant analysis using the power equation y=axb was negative for caudal fin span (S) versus fork length (FL) in C. carcharias. In contrast in two delphinid species, Delphinus capensis and Tursiops aduncus, the span of the flukes versus fork length rises in positive allometric fashion, and strong positive allometry of S versus √A (area) was also recorded. The latter reflects a high lift/drag ratio. S versus √A in C. carcharias displays negative allometry and consequently a lower lift/drag ratio. A lower aspect ratio (AR) caudal fin in C. carcharias compared to that of the delphinids (mean 3.33 and 4.1, respectively) and other thunniform swimmers provides the potential for better maneuverability and acceleration. The liver in sharks is frequently associated with a buoyancy function and was found to be positively allometric in C. carcharias. The overall findings suggest that the negatively allometric caudal fin morphometrics in C. carcharias are unlikely to have deleterious evolutionary fitness consequences for predation. On the contrary, when considered in the context of positive liver allometry in C. carcharias it is hereby suggested that buoyancy may play a dominant role in larger white sharks in permitting slow swimming while minimizing energy demands needed to prevent sinking. In contrast hydrodynamic lift is considered more important in smaller white sharks. Larger caudal fin spans and higher lift/drag ratio in smaller C. carcharias indicate greater potential for prolonged, intermediate swimming speeds and for feeding predominantly on fast-moving fish, in contrast to slow-swimming search patterns of larger individuals for predominantly large mammalian prey. Such data may provide some answers to the lifestyle and widespread habitat capabilities of this still largely mysterious animal.

Ice nucleating particles measured during the laboratory and field intercomparisons FIN-2 and FIN-3 by the diffusion chamber FRIDGE

Science.gov (United States)

Weber, Daniel; Schrod, Jann; Curtius, Joachim; Haunold, Werner; Thomson, Erik; Bingemer, Heinz

2016-04-01

The measurement of atmospheric ice nucleating particles (INP) is still challenging. In the absence of easily applicable INP standards the intercomparison of different methods during collaborative laboratory and field workshops is a valuable tool that can shine light on the performance of individual methods for the measurement of INP [1]. FIN-2 was conducted in March 2015 at the AIDA facility in Karlsruhe as an intercomparison of mobile instruments for measuring INP [2]. FIN-3 was a field campaign at the Desert Research Institutes Storm Peak Laboratory in Colorado in September 2015 [3]. The FRankfurt Ice nucleation Deposition freezinG Experiment (FRIDGE) participated in both experiments. FRIDGE measures ice nucleating particles by electrostatic precipitation of aerosol particles onto Si-wafers in a collection unit, followed by activation, growth, and optical detection of ice crystals on the substrate in an isostatic diffusion chamber [4,5]. We will present and discuss results of our measurements of deposition/condensation INP and of immersion INP with FRIDGE during FIN-2 and FIN-3. Acknowledgements: The valuable contributions of the FIN organizers and their institutions, and of the FIN Workshop Science team are gratefully acknowledged. Our work was supported by Deutsche Forschungsgemeinschaft (DFG) under the Research Unit FOR 1525 (INUIT) and the EU FP7-ENV- 2013 BACCHUS project under Grant Agreement 603445.

Numerical simulation of heat exchangers elliptical tubes and corrugated fins

International Nuclear Information System (INIS)

Borrajo Pérez, Rubén; González Bayón, Juan José; Menéndez Pérez, Alberto

2015-01-01

The intensified heat exchangers fins are widely used in the automotive and domestic industry. The low heat transfer coefficients on the air side are the main reason why these fins of heat exchangers need to be intensified. In this paper, the numerical simulation of a wavy fin type is made with elliptical tubes. The dimensions of the fin is in the range of those used in air conditioning equipment. The friction factor and the mass transfer coefficient as a function of the Reynolds number for this type of fin, always within the laminar regime is determined. The numerical model against experimental results published in the literature is validated. In addition the mechanisms that produce intensified heat transfer fin in such occur. (full text)

Ecomorphological inferences in early vertebrates: reconstructing Dunkleosteus terrelli (Arthrodira, Placodermi) caudal fin from palaeoecological data.

Science.gov (United States)

Ferrón, Humberto G; Martínez-Pérez, Carlos; Botella, Héctor

2017-01-01

Our knowledge about the body morphology of many extinct early vertebrates is very limited, especially in regard to their post-thoracic region. The prompt disarticulation of the dermo-skeletal elements due to taphonomic processes and the lack of a well-ossified endoskeleton in a large number of groups hinder the preservation of complete specimens. Previous reconstructions of most early vertebrates known from partial remains have been wholly based on phylogenetically closely related taxa. However, body design of fishes is determined, to a large extent, by their swimming mode and feeding niche, making it possible to recognise different morphological traits that have evolved several times in non-closely related groups with similar lifestyles. Based on this well-known ecomorphological correlation, here we propose a useful comparative framework established on extant taxa for predicting some anatomical aspects in extinct aquatic vertebrates from palaeoecological data and vice versa. For this, we have assessed the relationship between the locomotory patterns and the morphological variability of the caudal region in extant sharks by means of geometric morphometrics and allometric regression analysis. Multivariate analyses reveal a strong morphological convergence in non-closely related shark species that share similar modes of life, enabling the characterization of the caudal fin morphology of different ecological subgroups. In addition, interspecific positive allometry, affecting mainly the caudal fin span, has been detected. This phenomenon seems to be stronger in sharks with more pelagic habits, supporting its role as a compensation mechanism for the loss of hydrodynamic lift associated with the increase in body size, as previously suggested for many other living and extinct aquatic vertebrates. The quantification of shape change per unit size in each ecological subgroup has allowed us to establish a basis for inferring not only qualitative aspects of the caudal fin

Ecomorphological inferences in early vertebrates: reconstructing Dunkleosteus terrelli (Arthrodira, Placodermi caudal fin from palaeoecological data

Directory of Open Access Journals (Sweden)

Humberto G. Ferrón

2017-12-01

Full Text Available Our knowledge about the body morphology of many extinct early vertebrates is very limited, especially in regard to their post-thoracic region. The prompt disarticulation of the dermo-skeletal elements due to taphonomic processes and the lack of a well-ossified endoskeleton in a large number of groups hinder the preservation of complete specimens. Previous reconstructions of most early vertebrates known from partial remains have been wholly based on phylogenetically closely related taxa. However, body design of fishes is determined, to a large extent, by their swimming mode and feeding niche, making it possible to recognise different morphological traits that have evolved several times in non-closely related groups with similar lifestyles. Based on this well-known ecomorphological correlation, here we propose a useful comparative framework established on extant taxa for predicting some anatomical aspects in extinct aquatic vertebrates from palaeoecological data and vice versa. For this, we have assessed the relationship between the locomotory patterns and the morphological variability of the caudal region in extant sharks by means of geometric morphometrics and allometric regression analysis. Multivariate analyses reveal a strong morphological convergence in non-closely related shark species that share similar modes of life, enabling the characterization of the caudal fin morphology of different ecological subgroups. In addition, interspecific positive allometry, affecting mainly the caudal fin span, has been detected. This phenomenon seems to be stronger in sharks with more pelagic habits, supporting its role as a compensation mechanism for the loss of hydrodynamic lift associated with the increase in body size, as previously suggested for many other living and extinct aquatic vertebrates. The quantification of shape change per unit size in each ecological subgroup has allowed us to establish a basis for inferring not only qualitative aspects of

DETERMINATION OF THE TEMPERATURE DISTRIBUTION THE PERFORATED FINS UNDER

Directory of Open Access Journals (Sweden)

Aziz7 M. Mhamuad

2015-02-01

Full Text Available This work treats the problem of heat transfer for perforated fins under natural convection. The temperature distribution is examined for an array of rectangular fins (15 fins with uniform cross-sectional area (100x270 mm embedded with various vertical body perforations that extend through the fin thickness. The patterns of perforations include 18 circular perforations (holes. Experiments were carried out in an experimental facility that was specifically design and constructed for this purpose. The heat transfer rate and the coefficient of heat transfer increases with perforation diameter increased. 

Chromium Is Elevated in Fin Whale (Balaenoptera physalus) Skin Tissue and Is Genotoxic to Fin Whale Skin Cells

Science.gov (United States)

Wise, Catherine F.; Wise, Sandra S.; Thompson, W. Douglas; Perkins, Christopher; Wise, John Pierce

2015-01-01

Hexavalent chromium (Cr(VI)) is present in the marine environment and is a known carcinogen and reproductive toxicant. Cr(VI) is the form of chromium that is well absorbed through the cell membrane. It is also the most prevalent form in seawater. We measured the total Cr levels in skin biopsies obtained from healthy free-ranging fin whales from the Gulf of Maine and found elevated levels relative to marine mammals in other parts of the world. The levels in fin whale biopsies ranged from 1.71 ug/g to 19.6 ug/g with an average level of 10.07 ug/g. We also measured the cytotoxicity and genotoxicity of Cr(VI) in fin whale skin cells. We found that particulate and soluble Cr(VI) are both cytotoxic and genotoxic to fin whale skin cells in a concentration-dependent manner. The concentration range used in our cell culture studies used environmentally relevant concentrations based on the biopsy measurements. These data suggest that Cr(VI) may be a concern for whales in the Gulf of Maine. PMID:25805270

Evolution of microhabitat association and morphology in a diverse group of cryptobenthic coral reef fishes (Teleostei: Gobiidae: Eviota)

KAUST Repository

Tornabene, Luke; Ahmadia, Gabby N.; Berumen, Michael L.; Smith, David J.; Jompa, Jamaluddì n; Pezold, Frank L.

2013-01-01

Gobies (Teleostei: Gobiidae) are an extremely diverse and widely distributed group and are the second most species rich family of vertebrates. Ecological drivers are key to the evolutionary success of the Gobiidae. However, ecological and phylogenetic data are lacking for many diverse genera of gobies. Our study investigated the evolution of microhabitat association across the phylogeny of 18 species of dwarfgobies (genus Eviota), an abundant and diverse group of coral reef fishes. In addition, we also explore the evolution of pectoral fin-ray branching and sensory head pores to determine the relationship between morphological evolution and microhabitat shifts. Our results demonstrate that Eviota species switched multiple times from a facultative hard-coral association to inhabiting rubble or mixed sand/rubble habitat. We found no obvious relationship between microhabitat shifts and changes in pectoral fin-ray branching or reduction in sensory pores, with the latter character being highly homoplasious throughout the genus. The relative flexibility in coral-association in Eviota combined with the ability to move into non-coral habitats suggests a genetic capacity for ecological release in contrast to the strict obligate coral-dwelling relationship commonly observed in closely related coral gobies, thus promoting co-existence through fine scale niche partitioning. The variation in microhabitat association may facilitate opportunistic ecological speciation, and species persistence in the face of environmental change. This increased speciation opportunity, in concert with a high resilience to extinction, may explain the exceptionally high diversity seen in Eviota compared to related genera in the family. © 2012 Elsevier Inc.

Atom-probe for FinFET dopant characterization

Energy Technology Data Exchange (ETDEWEB)

Kambham, A.K., E-mail: kambham@imec.be [K.U.Leuven, Instituut voor Kern-en Stralings fysika, Celestijnenlaan 200D, B-3001, Leuven (Belgium); IMEC, Kapeldreef 75, B-3001 Leuven (Belgium); Mody, J.; Gilbert, M.; Koelling, S.; Vandervorst, W. [K.U.Leuven, Instituut voor Kern-en Stralings fysika, Celestijnenlaan 200D, B-3001, Leuven (Belgium); IMEC, Kapeldreef 75, B-3001 Leuven (Belgium)

2011-05-15

With the continuous shrinking of transistors and advent of new transistor architectures to keep in pace with Moore's law and ITRS goals, there is a rising interest in multigate 3D-devices like FinFETs where the channel is surrounded by gates on multiple surfaces. The performance of these devices depends on the dimensions and the spatial distribution of dopants in source/drain regions of the device. As a result there is a need for new metrology approach/technique to characterize quantitatively the dopant distribution in these devices with nanometer precision in 3D. In recent years, atom probe tomography (APT) has shown its ability to analyze semiconductor and thin insulator materials effectively with sub-nm resolution in 3D. In this paper we will discuss the methodology used to study FinFET-based structures using APT. Whereas challenges and solutions for sample preparation linked to the limited fin dimensions already have been reported before, we report here an approach to prepare fin structures for APT, which based on their processing history (trenches filled with Si) are in principle invisible in FIB and SEM. Hence alternative solutions in locating and positioning them on the APT-tip are presented. We also report on the use of the atom probe results on FinFETs to understand the role of different dopant implantation angles (10{sup o} and 45{sup o}) when attempting conformal doping of FinFETs and provide a quantitative comparison with alternative approaches such as 1D secondary ion mass spectrometry (SIMS) and theoretical model values. -- Research highlights: {yields} This paper provides the information on how to characterize the FinFET devices using atom probe tomography (APT). {yields} Importance of this work is to assess the performance of these devices at different processing conditions by extracting the compositional profiles. {yields} The performance of these devices depends on the dimensions and the spatial distribution of dopants in source/drain regions

Atom-probe for FinFET dopant characterization

International Nuclear Information System (INIS)

Kambham, A.K.; Mody, J.; Gilbert, M.; Koelling, S.; Vandervorst, W.

2011-01-01

With the continuous shrinking of transistors and advent of new transistor architectures to keep in pace with Moore's law and ITRS goals, there is a rising interest in multigate 3D-devices like FinFETs where the channel is surrounded by gates on multiple surfaces. The performance of these devices depends on the dimensions and the spatial distribution of dopants in source/drain regions of the device. As a result there is a need for new metrology approach/technique to characterize quantitatively the dopant distribution in these devices with nanometer precision in 3D. In recent years, atom probe tomography (APT) has shown its ability to analyze semiconductor and thin insulator materials effectively with sub-nm resolution in 3D. In this paper we will discuss the methodology used to study FinFET-based structures using APT. Whereas challenges and solutions for sample preparation linked to the limited fin dimensions already have been reported before, we report here an approach to prepare fin structures for APT, which based on their processing history (trenches filled with Si) are in principle invisible in FIB and SEM. Hence alternative solutions in locating and positioning them on the APT-tip are presented. We also report on the use of the atom probe results on FinFETs to understand the role of different dopant implantation angles (10 o and 45 o ) when attempting conformal doping of FinFETs and provide a quantitative comparison with alternative approaches such as 1D secondary ion mass spectrometry (SIMS) and theoretical model values. -- Research highlights: → This paper provides the information on how to characterize the FinFET devices using atom probe tomography (APT). → Importance of this work is to assess the performance of these devices at different processing conditions by extracting the compositional profiles. → The performance of these devices depends on the dimensions and the spatial distribution of dopants in source/drain regions. → In this publication we

Study of Swept Angle Effects on Grid Fins Aerodynamics Performance

Science.gov (United States)

Faza, G. A.; Fadillah, H.; Silitonga, F. Y.; Agoes Moelyadi, Mochamad

2018-04-01

Grid fin is an aerodynamic control surface that usually used on missiles and rockets. In the recent several years many researches have conducted to develop a more efficient grid fins. There are many possibilities of geometric combination could be done to improve aerodynamics characteristic of a grid fin. This paper will only discuss about the aerodynamics characteristics of grid fins compared by another grid fins with different swept angle. The methodology that used to compare the aerodynamics is Computational Fluid Dynamics (CFD). The result of this paper might be used for future studies to answer our former question or as a reference for related studies.

Optimization of Peripheral Finned-Tube Evaporators Using Entropy Generation Minimization

OpenAIRE

Pussoli, Bruno; Barbosa Jr., Jader; da Silva, Luciana; Kaviany, Massoud

2012-01-01

The peripheral finned-tube (PFT) is a new geometry for enhanced air-side heat transfer under moisture condensate blockage (evaporators). It consists of individual hexagonal (peripheral) fin arrangements with radial fins whose bases are attached to the tubes and tips are interconnected with the peripheral fins. In this paper, experimentally validated semi-empirical models for the air-side heat transfer and pressure drop are combined with the entropy generation minimization theory to determine ...

Quantitative assessment of accumulation of radionuclides in fish organism in dependence on water temperature

International Nuclear Information System (INIS)

Katkov, A.E.

1980-01-01

Eperimentally studied are the changes of levels of several indices of radionuclide metabolism in fishes in dependence on water temperature at its absorption directly from water and at introduction into the digestive tract. Presented are the coefficients of radionuclide storage by the fish tissues in the dependence on temperature (scales and fins, gills, head, intestines, skin, muscles, axial skeleton) and the coefficients of radionuclide retention in the whole fish. It is shown that the connection between the coefficient of radionuclide storage in the fish organism and water temperature is described by the logarithmic dependence. At the systematic entering of radionuclides into the digestive tract the retention coefficient of them in the organism expressed in the form of the ratio of residual quantity in the fish to the quantity in day dose is constant

Fin de Copenhague

DEFF Research Database (Denmark)

Baumeister, Ruth

2016-01-01

FIN DE COPENHAGUE this book by the Danish Cobra artist Asger Jorn and the French philosopher Guy Debord, is the first in a series of two and was published in 1957, shortly before the authors founded the Situationist International. According to Jorn, upon arrival to Copenhagen, they stole some...

The optimization of longitudinal convective fins with internal heat generation

International Nuclear Information System (INIS)

Razelos, P.

1979-01-01

The solution of the optimization problem for longitudinal convective fins of constant thickness, triangular or parabolic profile, and uniform internal heat generation, is presented. The cases considered are those of a given heat generation density, total heat generation and heat generation per unit width of the fin, when either the heat dissipation or the width of the fin is prescribed. The results are set forth in a nondimensional form, which are presented graphically. The effect of the fin's thermal conductivity upon the optimum dimensions is discussed, and limiting values for the heat generation and the heat dissipation, which may be imposed on the fin for a feasible optimization, are also obtained. (Auth.)

Research on dynamic characteristics of new chaotic-advection fins

International Nuclear Information System (INIS)

Kong Songtao; Dong Qiwu; Liu Minshan; Zhu Qing

2007-01-01

Analysis and the numerical simulation has confirmed that the flow is of the chaotic advection in the flow channel of the new fin. The chaotic advection results in stronger mixing under low Re, and thus enhances the heat transfer and anti-scaling ability. The new fin provides the beneficial exploration to the concept of chaotic advection which applies to the plate-fin heat exchanger. (authors)

Stress analysis of plate-fin structures in recuperator

International Nuclear Information System (INIS)

Matsui, Shingo; Muto, Yasushi; Shiina, Yasuaki

2001-01-01

A high performance compact recuperator with 95% effectiveness is required to achieve a high thermal efficiency power generation of up to 50% in High Temperature Gas Cooled Reactor (HTGR) coupled with closed cycle helium gas turbine. Though a plate-fin type heat exchanger is proposed for this recuperator, much research and development works are needed to establish this high performance goal since there exists no state-of-the-art technology in such a high pressure and high temperature one. One of the important works is to establish the structural analysis and evaluation method in this plate-fin type heat exchanger. This paper describes the results of stress analysis of the plate-fin structure under the internal pressure as the first step of this work. First, the modeling of a unit plate-fin structure for the analysis was examined and a three layers model was confirmed to be most adequate. The stress distribution within the structure was clarified by using this model. Second, the three layers model was simplified to one layer model with sufficient accuracy. By using this model, both the effects of an inclined angle of fin and a thickness of separate on the strength were examined parametrically. Under the relevant design conditions, it was revealed that the optimum inclined angle of fin locates in the neighborhood of 76 degree rather than most difficult fabrication angle 90 degree and there is possibility to adopt thinner thickness than 0.5 mm in the current design. (author)

Strain characterization of FinFETs using Raman spectroscopy

International Nuclear Information System (INIS)

Kaleli, B.; Hemert, T. van; Hueting, R.J.E.; Wolters, R.A.M.

2013-01-01

Metal induced strain in the channel region of silicon (Si) fin-field effect transistor (FinFET) devices has been characterized using Raman spectroscopy. The strain originates from the difference in thermal expansion coefficient of Si and titanium-nitride. The Raman map of the device region is used to determine strain in the channel after preparing the device with the focused ion beam milling. Using the Raman peak shift relative to that of relaxed Si, compressive strain values up to – 0.88% have been obtained for a 5 nm wide silicon fin. The strain is found to increase with reducing fin width though it scales less than previously reported results from holographic interferometry. In addition, finite-element method (FEM) simulations have been utilized to analyze the amount of strain generated after thermal processing. It is shown that obtained FEM simulated strain values are in good agreement with the calculated strain values obtained from Raman spectroscopy. - Highlights: ► Strain is characterized in nanoscale devices with Raman spectroscopy. ► There is a fin width dependence of the originated strain. ► Strain levels obtained from this technique is in correlation with device simulations

Quality improvement on half-fin anchovy (Setipinna taty) fish sauce by Psychrobacter sp. SP-1 fermentation.

Science.gov (United States)

Zheng, Bin; Liu, Yu; He, Xiaoxia; Hu, Shiwei; Li, Shijie; Chen, Meiling; Jiang, Wei

2017-10-01

A method of improving fish sauce quality during fermentation was investigated. Psychrobacter sp. SP-1, a halophilic protease-producing bacterium, was isolated from fish sauce with flavor-enhancing properties and non-biogenic amine-producing activity. The performance of Psychrobacter sp. SP-1 in Setipinna taty fish sauce fermentation was investigated further. The inoculation of Psychrobacter sp. SP-1 did not significantly affect pH or NaCl concentration changes (P > 0.05), although it significantly increased total moderately halophilic microbial count, protease activity, total soluble nitrogen content and amino acid nitrogen content, and also promoted the umami taste and meaty aroma (P sauce quality by fermentation. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

The Influence of Culture on the International Management of Shark Finning

Science.gov (United States)

Dell'Apa, Andrea; Chad Smith, M.; Kaneshiro-Pineiro, Mahealani Y.

2014-08-01

Shark finning is prohibited in many countries, but high prices for fins from the Asian market help maintain the international black-market and poaching. Traditional shark fin bans fail to recognize that the main driver of fin exploitation is linked to cultural beliefs about sharks in traditional Chinese culture. Therefore, shark finning should be addressed considering the social science approach as part of the fishery management scheme. This paper investigates the cultural significance of sharks in traditional Chinese and Hawaiian cultures, as valuable examples of how specific differences in cultural beliefs can drive individuals' attitudes toward the property of shark finning. We suggest the use of a social science approach that can be useful in the design of successful education campaigns to help change individuals' attitudes toward shark fin consumption. Finally, alternative management strategies for commercial fishers are provided to maintain self-sustainability of local coastal communities.

Encephalization in tropical teleost fishes and comparison with their mode of life.

Science.gov (United States)

Bauchot, R; Randall, J E; Ridet, J M; Bauchot, M L

1989-01-01

The brains were dissected from a total of 1225 fishes representing 737 species, 310 genera and 113 families of tropical and subtropical teleosts. Each fish was weighed before brain dissection, and each brain weighed after its removal. The encephalization coefficient k was determined for each fish from a quadratic formula; to conveniently compare brain size of one species with that of another, we used an encephalization index so that an encephalization index of 100 is the average for all the species investigated. The encephalization indices for the families of fishes studied varied from 7 for the Moringuidae to 233 for the Coryphaenidae. There is no strong correlation in relative brain size with phylogenetic position. Although there is a general trend for the more highly evolved fishes to have larger brains, this is partially obscured by some high values in certain primitive groups and low ones in the more advanced. Elongate fishes have lower encephalization indices in general. This may in part be related to low phylogenetic position of most elongate species (anguilliform fishes, for example), in part to the greater relative body weight due to the longer vertebral column (and usually more numerous fin rays as as well), and to their usual mode of swimming by lateral undulations of the body (the most primitive type of aquatic locomotion--one in which the spinal cord plays a major role). No difference could be noted in the encephalization indices of herbivorous families of fishes compared to carnivorous ones. Within a genus, among medium to large-size fishes, those species of larger size tend to have lower encephalization indices. This may be related to larger fishes having less to fear of predators. Fishes which in some passive way avoid predation have low indices in general. This is particularly true of benthic species which conceal themselves by flattened form, fleshy protuberances or protective coloration, or which bury in the sediment or take refuge in burrows

The origin and evolution of the surfactant system in fish: insights into the evolution of lungs and swim bladders.

Science.gov (United States)

Daniels, Christopher B; Orgeig, Sandra; Sullivan, Lucy C; Ling, Nicholas; Bennett, Michael B; Schürch, Samuel; Val, Adalberto Luis; Brauner, Colin J

2004-01-01

Several times throughout their radiation fish have evolved either lungs or swim bladders as gas-holding structures. Lungs and swim bladders have different ontogenetic origins and can be used either for buoyancy or as an accessory respiratory organ. Therefore, the presence of air-filled bladders or lungs in different groups of fishes is an example of convergent evolution. We propose that air breathing could not occur without the presence of a surfactant system and suggest that this system may have originated in epithelial cells lining the pharynx. Here we present new data on the surfactant system in swim bladders of three teleost fish (the air-breathing pirarucu Arapaima gigas and tarpon Megalops cyprinoides and the non-air-breathing New Zealand snapper Pagrus auratus). We determined the presence of surfactant using biochemical, biophysical, and morphological analyses and determined homology using immunohistochemical analysis of the surfactant proteins (SPs). We relate the presence and structure of the surfactant system to those previously described in the swim bladders of another teleost, the goldfish, and those of the air-breathing organs of the other members of the Osteichthyes, the more primitive air-breathing Actinopterygii and the Sarcopterygii. Snapper and tarpon swim bladders are lined with squamous and cuboidal epithelial cells, respectively, containing membrane-bound lamellar bodies. Phosphatidylcholine dominates the phospholipid (PL) profile of lavage material from all fish analyzed to date. The presence of the characteristic surfactant lipids in pirarucu and tarpon, lamellar bodies in tarpon and snapper, SP-B in tarpon and pirarucu lavage, and SPs (A, B, and D) in swim bladder tissue of the tarpon provide strong evidence that the surfactant system of teleosts is homologous with that of other fish and of tetrapods. This study is the first demonstration of the presence of SP-D in the air-breathing organs of nonmammalian species and SP-B in actinopterygian

情报研究在FinTech实践中的应用展望%The Application Prospect of Information Science in FinTech Practice

Institute of Scientific and Technical Information of China (English)

徐扬; 刘姝雯; 腾菲; 罗晶

2017-01-01

[目的/意义]针对金融科技(FinTech)发展的特征、现状及问题,探究情报学知识和技术在FinTech实践中的应用和发展方向.[方法/过程]梳理Fintech概念在国内外的发展历程和现状,并从情报学视角,讨论FinTech在特征、应用、监管等方面的研究展望,提出相应的建议.[结果/结论]研究结果表明,情报学与FinTech相辅相成,共同发展.未来,可以进一步强化FinTech业务的信息化与数字化,加强情报分析、商务智能以及情报学视角的大数据分析,为FinTech的发展注入更多的活力.

Forced convection heat transfer correlation for finned plates in a duct

International Nuclear Information System (INIS)

Chae, Myeong-Seon; Moon, Je-Young; Chung, Bum-Jin

2014-01-01

Forced convection heat transfer experiments were conducted for plate-fin in a duct using various fin spacing, fin height, duct width, Reynolds number for Prandtl numbers 2,014. Based upon analogy concept, mass transfer rate were measured instead of heat transfer rates. The heat transfer rates were enhanced with the increase of fin height and decrease of fin spacing as they increase the heat transfer area. Meanwhile, heat transfer rates were impaired with the increase of the duct width as the bypass flows increased to tip clearance region. Forced convection heat transfer correlations were developed for laminar and turbulent flow conditions and for narrow and wide ducts. The work draws attention to the tip clearance on the heat transfer of the finned plate in a duct. (author)

Determination of chromium, mercury, selenium and zinc in marine fish species of Malaysia

International Nuclear Information System (INIS)

Nazaratul Ashifa Abdullah Salim; Wee, B.S.; Ezwiza Sanuri; Mohd Suhaimi Hamzah; Mohd Suhaimi Elias, Shamsiah Abdul Rahman; Azian Hashim

2013-01-01

Full-text: Concentrations of chromium, mercury, selenium and zinc were determined in eight commonly edible marine fish species; mackerel, red snapper, thread fin, tuna, hard tail scads, val, doubled spotted queen fish and shark. This study was based on market basket method were those species were collected from two locations of Kuala Selangor and Kuala Terengganu. All elements were measured using instrumental neutron activation analysis (INAA) technique. The accuracy and precision analysis were checked by analyzing Certified Reference Material (CRM) namely DORM-3 and MAA-2. Elements of interest in the edible parts of the investigated fish were mostly in the permissible safety levels for human consumption based on national and international safety guideline except for mercury where some fishes showed slightly higher concentrations than the guidelines. (author)

A biologically inspired artificial fish using flexible matrix composite actuators: analysis and experiment

International Nuclear Information System (INIS)

Zhang, Zhiye; Philen, Michael; Neu, Wayne

2010-01-01

A bio-inspired prototype fish using the flexible matrix composite (FMC) muscle technology for fin and body actuation is developed. FMC actuators are pressure driven muscle-like actuators capable of large displacements as well as large blocking forces. An analytical model of the artificial fish using FMC actuators is developed and analysis results are presented. An experimental prototype of the artificial fish having FMC artificial muscles has been completed and tested. Constant mean thrusts have been achieved in the laboratory for a stationary fish for different undulation frequencies around 1 Hz. The experimental results demonstrate that a nearly constant thrust can be achieved through tuning of excitation frequency for given body stiffness. Free swimming results show that the prototype can swim at approximately 0.3 m s −1

Externally finned circular tube immerse in a phase-change material

International Nuclear Information System (INIS)

Alves, C.L.F.; Ismail, K.A.R.

1985-01-01

In an attempt to increase the heat transfer rate and reduce the convective currents during the freezing of phase change materials (PCM) in storage tanks, externally finned circular tubes are studied experimentally. The parameters analysed in this work include number of fins, fin length, initial degree of superheat and freezing time

Investigation of thermal effects on FinFETs in the quasi-ballistic regime

Science.gov (United States)

Yin, Longxiang; Shen, Lei; Di, Shaoyan; Du, Gang; Liu, Xiaoyan

2018-04-01

In this work, the thermal effects of FinFETs in the quasi-ballistic regime are investigated using the Monte Carlo method. Bulk Si nFinFETs with the same fin structure and two different gate lengths L g = 20 and 80 nm are investigated and compared to evaluate the thermal effects on the performance of FinFETs in the quasi-ballistic regime. The on current of the 20 nm FinFET with V gs = 0.7 V does not decrease with increasing lattice temperature (T L) at a high V ds. The electrostatic properties in the 20 nm FinFET are more affected by T L than those in the 80 nm FinFET. However, the electron transport in the 20 nm FinFET is less affected by T L than that in the 80 nm FinFET. The electrostatic properties being more sensitive and the electron transport being less sensitive to thermal effects in the quasi-ballistic regime than in the diffusive regime should be considered for effective device modeling and design.

Self-propelled heaving and pitching flexible fin in a quiescent flow

International Nuclear Information System (INIS)

Kim, Boyoung; Park, Sung Goon; Huang, Weixi; Sung, Hyung Jin

2016-01-01

Highlights: • A self-propelled flexible fin with heaving and pitching motions in a quiescent flow has been simulated by using the penalty immersed boundary method. • The cruising speed and the swimming efficiency of the self-propelled fin were determined as functions of the bending coefficient (γ), the heaving amplitude (A_h). • We optimized the cruising speed and the swimming efficiency with respect to γ, f, A_h, A_p, and Δϕ. - Abstract: A self-propelled flexible fin with heaving and pitching motions in a quiescent flow has been simulated by using the penalty immersed boundary method. The flexible fin can move freely in the horizontal direction and the body of the flexible fin moves passively along with the active head motion. The position of the head of the fin was described as a harmonic heaving oscillation in the vertical direction, while the inclination angle of the head was prescribed as a harmonic oscillation with a moving clamped condition for the heaving and pitching fin. The cruising speed and the swimming efficiency of the self-propelled fin were determined as functions of the bending stiffness (γ), the heaving amplitude (A_h), the pitching amplitude (A_p), the flapping frequency (f) and the phase difference (Δϕ) between A_h and A_p. We optimized the cruising speed and the swimming efficiency with respect to γ, f, A_h, A_p and Δϕ. For a certain range of A_p, the swimming efficiency of the heaving and pitching fin is larger than that of a heaving-only fin.

Vortex Shedding from Finned Circular Cylinders

Science.gov (United States)

1980-11-01

FINNED CIRCULAR CYLINDERSo ,rm"" 1..UTNOI .)R*., r. *.040, 111SPOR- / T NuMBII f.John G. elute asOHans J.’/, ugt -. . . , ,<-. -. ,:. =., .. Siil P3RPIO...fins and other sharp protuberances. These purely two-dimensional flows then may be used in a strip theory to include at least some aspects of three...boundary- layer theory . Such a prediction method, together with a technique to provide for a vortex sheet at the separation point, will be included in

Highly flexible SRAM cells based on novel tri-independent-gate FinFET

Science.gov (United States)

Liu, Chengsheng; Zheng, Fanglin; Sun, Yabin; Li, Xiaojin; Shi, Yanling

2017-10-01

In this paper, a novel tri-independent-gate (TIG) FinFET is proposed for highly flexible SRAM cells design. To mitigate the read-write conflict, two kinds of SRAM cells based on TIG FinFETs are designed, and high tradeoff are obtained between read stability and speed. Both cells can offer multi read operations for frequency requirement with single voltage supply. In the first TIG FinFET SRAM cell, the strength of single-fin access transistor (TIG FinFET) can be flexibly adjusted by selecting five different modes to meet the needs of dynamic frequency design. Compared to the previous double-independent-gate (DIG) FinFET SRAM cell, 12.16% shorter read delay can be achieved with only 1.62% read stability decrement. As for the second TIG FinFET SRAM cell, pass-gate feedback technology is applied and double-fin TIG FinFETs are used as access transistors to solve the severe write-ability degradation. Three modes exist to flexibly adjust read speed and stability, and 68.2% larger write margin and 51.7% shorter write delay are achieved at only the expense of 26.2% increase in leakage power, with the same layout area as conventional FinFET SRAM cell.

Global ecological success of Thalassoma fishes in extreme coral reef habitats

KAUST Repository

Fulton, Christopher J.

2016-12-20

Phenotypic adaptations can allow organisms to relax abiotic selection and facilitate their ecological success in challenging habitats, yet we have relatively little data for the prevalence of this phenomenon at macroecological scales. Using data on the relative abundance of coral reef wrasses and parrotfishes (f. Labridae) spread across three ocean basins and the Red Sea, we reveal the consistent global dominance of extreme wave-swept habitats by fishes in the genus Thalassoma, with abundances up to 15 times higher than any other labrid. A key locomotor modification-a winged pectoral fin that facilitates efficient underwater flight in high-flow environments-is likely to have underpinned this global success, as numerical dominance by Thalassoma was contingent upon the presence of high-intensity wave energy. The ecological success of the most abundant species also varied with species richness and the presence of congeneric competitors. While several fish taxa have independently evolved winged pectoral fins, Thalassoma appears to have combined efficient high-speed swimming (to relax abiotic selection) with trophic versatility (to maximize exploitation of rich resources) to exploit and dominate extreme coral reef habitats around the world.

Global ecological success of Thalassoma fishes in extreme coral reef habitats.

Science.gov (United States)

Fulton, Christopher J; Wainwright, Peter C; Hoey, Andrew S; Bellwood, David R

2017-01-01

Phenotypic adaptations can allow organisms to relax abiotic selection and facilitate their ecological success in challenging habitats, yet we have relatively little data for the prevalence of this phenomenon at macroecological scales. Using data on the relative abundance of coral reef wrasses and parrotfishes (f. Labridae) spread across three ocean basins and the Red Sea, we reveal the consistent global dominance of extreme wave-swept habitats by fishes in the genus Thalassoma , with abundances up to 15 times higher than any other labrid. A key locomotor modification-a winged pectoral fin that facilitates efficient underwater flight in high-flow environments-is likely to have underpinned this global success, as numerical dominance by Thalassoma was contingent upon the presence of high-intensity wave energy. The ecological success of the most abundant species also varied with species richness and the presence of congeneric competitors. While several fish taxa have independently evolved winged pectoral fins, Thalassoma appears to have combined efficient high-speed swimming (to relax abiotic selection) with trophic versatility (to maximize exploitation of rich resources) to exploit and dominate extreme coral reef habitats around the world.

Global ecological success of Thalassoma fishes in extreme coral reef habitats

KAUST Repository

Fulton, Christopher J.; Wainwright, Peter C.; Hoey, Andrew; Bellwood, David R.

2016-01-01

Phenotypic adaptations can allow organisms to relax abiotic selection and facilitate their ecological success in challenging habitats, yet we have relatively little data for the prevalence of this phenomenon at macroecological scales. Using data on the relative abundance of coral reef wrasses and parrotfishes (f. Labridae) spread across three ocean basins and the Red Sea, we reveal the consistent global dominance of extreme wave-swept habitats by fishes in the genus Thalassoma, with abundances up to 15 times higher than any other labrid. A key locomotor modification-a winged pectoral fin that facilitates efficient underwater flight in high-flow environments-is likely to have underpinned this global success, as numerical dominance by Thalassoma was contingent upon the presence of high-intensity wave energy. The ecological success of the most abundant species also varied with species richness and the presence of congeneric competitors. While several fish taxa have independently evolved winged pectoral fins, Thalassoma appears to have combined efficient high-speed swimming (to relax abiotic selection) with trophic versatility (to maximize exploitation of rich resources) to exploit and dominate extreme coral reef habitats around the world.

Evolutionary mechanisms that generate morphology and neural-circuit diversity of the cerebellum.

Science.gov (United States)

Hibi, Masahiko; Matsuda, Koji; Takeuchi, Miki; Shimizu, Takashi; Murakami, Yasunori

2017-05-01

The cerebellum is derived from the dorsal part of the anterior-most hindbrain. The vertebrate cerebellum contains glutamatergic granule cells (GCs) and gamma-aminobutyric acid (GABA)ergic Purkinje cells (PCs). These cerebellar neurons are generated from neuronal progenitors or neural stem cells by mechanisms that are conserved among vertebrates. However, vertebrate cerebella are widely diverse with respect to their gross morphology and neural circuits. The cerebellum of cyclostomes, the basal vertebrates, has a negligible structure. Cartilaginous fishes have a cerebellum containing GCs, PCs, and deep cerebellar nuclei (DCNs), which include projection neurons. Ray-finned fish lack DCNs but have projection neurons termed eurydendroid cells (ECs) in the vicinity of the PCs. Among ray-finned fishes, the cerebellum of teleost zebrafish has a simple lobular structure, whereas that of weakly electric mormyrid fish is large and foliated. Amniotes, which include mammals, independently evolved a large, foliated cerebellum, which contains massive numbers of GCs and has functional connections with the dorsal telencephalon (neocortex). Recent studies of cyclostomes and cartilaginous fish suggest that the genetic program for cerebellum development was already encoded in the genome of ancestral vertebrates. In this review, we discuss how alterations of the genetic and cellular programs generated diversity of the cerebellum during evolution. © 2017 Japanese Society of Developmental Biologists.

The Cx43-like connexin protein Cx40.8 is differentially localized during fin ontogeny and fin regeneration.

Directory of Open Access Journals (Sweden)

Sarah V Gerhart

Full Text Available Connexins (Cx are the subunits of gap junctions, membraneous protein channels that permit the exchange of small molecules between adjacent cells. Cx43 is required for cell proliferation in the zebrafish caudal fin. Previously, we found that a Cx43-like connexin, cx40.8, is co-expressed with cx43 in the population of proliferating cells during fin regeneration. Here we demonstrate that Cx40.8 exhibits novel differential subcellular localization in vivo, depending on the growth status of the fin. During fin ontogeny, Cx40.8 is found at the plasma membrane, but Cx40.8 is retained in the Golgi apparatus during regeneration. We next identified a 30 amino acid domain of Cx40.8 responsible for its dynamic localization. One possible explanation for the differential localization is that Cx40.8 contributes to the regulation of Cx43 in vivo, perhaps modifying channel activity during ontogenetic growth. However, we find that the voltage-gating properties of Cx40.8 are similar to Cx43. Together our findings reveal that Cx40.8 exhibits differential subcellular localization in vivo, dependent on a discrete domain in its carboxy terminus. We suggest that the dynamic localization of Cx40.8 differentially influences Cx43-dependent cell proliferation during ontogeny and regeneration.

Performance and optimum design of convective-radiative rectangular fin with convective base heating, wall conduction resistance, and contact resistance between the wall and the fin base

International Nuclear Information System (INIS)

Aziz, Abdul; Beers-Green, Arlen B.

2009-01-01

This paper investigates the performance and optimum design of a longitudinal rectangular fin attached to a convectively heated wall of finite thickness. The exposed surfaces of the fin lose heat to the environmental sink by simultaneous convection and radiation. The tip of the fin is assumed to lose heat by convection and radiation to the same sink. The analysis and optimization of the fin is conducted numerically using the symbolic algebra package Maple. The temperature distribution, the heat transfer rates, and the fin efficiency data is presented illustrating how the thermal performance of the fin is affected by the convection-conduction number, the radiation-conduction number, the base convection Biot number, the convection and radiation Biot numbers at the tip, and the dimensionless sink temperature. Charts are presented showing the relationship between the optimum convection-conduction number and the optimum radiation-conduction number for different values of the base convection Biot number and dimensionless sink temperature and fixed values of the convection and radiation Biot numbers at the tip. Unlike the few other papers which have applied the Adomian's decomposition and the differential quadrature element method to this problem but give illustrative results for specific fin geometry and thermal variables, the present graphical data are generally applicable and can be used by fin designers without delving into the mathematical details of the computational techniques.

A new genus and species of characid fish from the Amazon basin: the recognition of a relictual lineage of characid fishes (Ostariophysi: Cheirodontinae: Cheirodontini

Directory of Open Access Journals (Sweden)

Cristina M. Bührnheim

Full Text Available Amazonspinther dalmata, a new miniature characid from the streams of rio Purus and rio Madeira, right bank tributaries of the rio Amazonas, is described as a new genus and species of the subfamily Cheirodontinae. The unique characters of the new genus and species are the three remarkable black blotches on the base of the dorsal, anal, and caudal fins, the anteriormost proximal radial of the anal fin with an anteriorly extended lamina entering the abdominal cavity, and the extremely elongate caudal peduncle. The reduced number of ventral procurrent caudal-fin rays (7-9, and the hemal spines of only posterior one, two, or sometimes three caudal vertebrae directly articulating with the ventral procurrent caudal-fin rays further diagnoses the new taxon from remaining genera of the tribe Cheirodontini. The results of a phylogenetic analysis strongly support a close relationship between A. dalmata and Spintherobolus in the tribe Cheirodontini on the basis of fifteen unambiguous synapomorphies. Ten of these characters, previously hypothesized as exclusive synapomorphies for Spintherobolus, were now also identified in Amazonspinther, such as the pattern of exposed neuromasts on the head, the presence of a second pseudotympanum anterior to the first pleural rib, and the nearly discoidal coracoid bone. A discussion about the phylogenetic position of the closely related fossil †Megacheirodon to Spintherobolus and Amazonspinther is also provided. Convergent characters shared between Amazonspinther and the characid Priocharax are discussed in relation to miniaturization. Biogeographical implications of the diversification of Amazonspinther, Spintherobolus, and Megacheirodon lineages are discussed.

A numerical method for PCM-based pin fin heat sinks optimization

International Nuclear Information System (INIS)

Pakrouh, R.; Hosseini, M.J.; Ranjbar, A.A.; Bahrampoury, R.

2015-01-01

Highlights: • Optimization of PCM-based heat sink by using the Taguchi method. • Derivation of optimal PCM percentage to reach the maximum critical time. • Optimization is performed for four different critical temperatures. • Effective design factors are fins’ height and fins’ number. • The optimum configuration depends on geometric properties and the critical temperature. - Abstract: This paper presents a numerical investigation on geometric optimization of PCM-based pin fin heat sinks. Paraffin RT44HC is used as PCM while the fins and heat sink base is made of aluminum. The fins act as thermal conductivity enhancers (TCEs). The main goal of the study is to obtain the configurations that maximize the heat sink operational time. An approach witch couples Taguchi method with numerical simulations is utilized for this purpose. Number of fins, fins height, fins thickness and the base thickness are parameters which are studied for optimization. In this study natural convection and PCM volume variation during melting process are considered in the simulations. Optimization is performed for different critical temperatures of 50 °C, 60 °C, 70 °C and 80 °C. Results show that a complex relation exists between PCM and TCE volume percentages. The optimal case strongly depends on the fins’ number, fins’ height and thickness and also the critical temperature. The optimum PCM percentages are found to be 60.61% (corresponds to 100 pin fin heat sink with 4 mm thick fins) for critical temperature of 50 °C and 82.65% (corresponds to 100 pin fin heat sink with 2 mm thick fins) for other critical temperatures

FinTech transformation: how it-enabled innovations shape the financial sector

OpenAIRE

Zavolokina, Liudmila; Dolata, Mateusz; Schwabe, Gerhard

2016-01-01

FinTech, the phenomenon which spans over the areas of information technologies and financial innovation, is currently on the rise and is gaining more and more attention from practitioners, investors and researchers. FinTech is broadly discussed by the media, which constitutes its understanding and represents social opinion, however, this perception of FinTech should be supported by empirical evidences. Therefore, we examine five Swiss FinTech companies through the lens of the conceptual frame...

Paleoserranus lakamhae gen. et sp. nov., a Paleocene seabass (Perciformes: Serranidae) from Palenque, Chiapas, southeastern Mexico

Science.gov (United States)

Cantalice, Kleyton M.; Alvarado-Ortega, Jesús; Alaniz-Galvan, Abril

2018-04-01

Paleoserranus lakamhae gen. et sp. nov. is here described based on well-preserved fossils from the Paleocene marine sediments of the Tenejapa-Lacandón geological unit, belonging to both Division del Norte and Belisario Domínguez quarries, near Palenque, Chiapas, southeastern Mexico. This species exhibits distinctive characters of the order Perciformes, such as the presence of spines in the dorsal, pelvic, and anal fins, as well as the pelvic and pectoral girdles in contact between them. This fish also has neither procurrent spur nor posterior uroneural, characters that support its place within the family Serranidae. It also has a distinctive combination of characters, including a serrated lacrimal and a toothed ectopterygoid, never recorded before among serranids. Additionally, this fossil fish shares some characters with different species nested within the subfamilies Serraninae, Anthiinae, and Ephinephelinae; these include a predorsal formula of 0/0/0 + 2/1 + 1/1; a preopercle with its ventral edge sinuous and showing a strong antrorse spine; its dorsal fin consists of nine spines and eight to ten soft rays; 13 rays in its pectoral fin; and its rounded caudal fin structured with formula I+8-7+I. Paleoserranus lakamhae gen. et sp. nov. is a Serranidae incertae sedis because it does not fit into any subgroup; however, this Paleocene fish is the earliest fossil record of the family Serranidae. The place of occurrence of this new fossil record suggests that the origin and of the seabasses took place in the Caribbean region of North America.

Role of Fish Oil against Physiological Disturbances in Rats Brain Induced by Sodium Fluoride and/or Gamma Rays

International Nuclear Information System (INIS)

Said, U.Z.; El-Tahawy, N.A.; Ibrahim, F.R.; Kamal, G.M.; EL-Sayed, T.M.

2015-01-01

The impacts of environmental and occupational exposure to ionizing radiation and to long-term intake of high levels of fluoride have caused health problems and increasingly alarming in recent years. Fish oil omega-3 (polyunsaturated fatty acids essential fatty acids) is found in the highest concentrations in fish oil, claim a plethora of health benefits. The objective of the present study was to evaluate the role of fish oil rich in omega-3 fatty acids on sodium fluoride (NaF) and or gamma (γ) rays in inducing neurological and biochemical disturbances in rat’s brain cerebral hemispheres. The results revealed that whole body exposure to γ- radiation at 6 Gy applied as fractionated doses (1.5 Gy x 4 times) and/or chronic receipt of NaF solution (0.13 mg/Kg/day) for a period of 28 days, significantly increased brain fluoride and calcium content, decreased level of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) and induced brain oxidative stress which led to neurotransmitters dysfunction. Supplementation of treated rats with fish oil, via gavages, at a dose of 400 mg/kg body wt has significantly modulated oxidative stress and neurotransmitters alterations. It could be concluded that EPA and DHA, found in fish oil, could possibly protect brain from damaging free radicals and consequently minimize the severity of brain biochemical disturbances

Thermohydraulic analysis of smooth and finned annular ducts

International Nuclear Information System (INIS)

Braga, C.V.M.

1987-01-01

The present work is concerned with the turbulent heat transfer and pressure drop in smooth and finned annular ducts overage heat transfer coefficients have been obtained by means of the heat exchanger theory. In addition, friction factors have also been determined. The experiments were performed by utilizing four double-pipe heat exchangers. The flowing fluids, in the heat exchangers, were air and water. The average heat transfer coefficients, for air flowing in the annular section, were determined by measuring the overall heat transfer coefficients of the heat exchangers. In order to attain fully developed conditions, the heat exchangers had a starting length of 30 hydraulic diameters. The thermal boundary conditions consisted of uniform temperature on the inner surface, the outer surface being insulated. The heat transfer coefficients and friction factors are presented in dimensionaless forms, as functions of the Reynolds number of the flow. The results for the smooth and finned annular ducts were compared. The purpose of such comparison was to study the influence of the fins on the pressure drop and heat transfer rate. In the case of the finned nular ducts, it is shown that the fin efficiency has some fluence on the heat transfer rates. The, a two-dimensional at transfer analysis was performed in order to obtain the n efficiency and the annular region efficiency. It is also shown that the overall thermal performance of finned surfaces epends mainly on the Nusselt number and on the region eficiency. These parameters are presented as functions of the Reynolds number of the flow and the geometry of the problem. (author) [pt

Heat transfer and pressure drop characteristics of mini-fin structures

International Nuclear Information System (INIS)

Jiang Peixue; Xu Ruina

2007-01-01

Forced convection heat transfer of air and water in bronze and pure copper mini-fin structures and mini-channel structures was investigated experimentally. The mini-fin dimensions were 0.7 mm x 0.2 mm and 0.8 mm x 0.4 mm. The tests included both staggered diamond-shaped and in-line square mini-fin arrangements. The tests investigated the effects of structures, mini-fin dimensions and arrangement, test section materials, and fluid properties on the convection heat transfer and heat transfer enhancement. For the tested conditions, the convection heat transfer coefficient was increased 9-21 fold for water and 12-38 fold for air in the mini-fin structures compared with an empty plate channel. The friction factor and flow resistance in the mini-channel structures and the in-line square mini-fin arrangement were much less than in the staggered diamond-shaped mini-fin arrangement. For the small channel width, W c = 0.2 mm, the convection heat transfer with the in-line square array structure was more intense than with the staggered diamond-shaped structure, the mini-channel structure or the porous media. For the larger channel width, W c = 0.4 mm, the convection heat transfer in the staggered diamond-shaped array structure was more intense than in the others systems while the in-line square structure had the best overall thermal-hydraulic performance

A Numerical Study of Natural Convection Heat Transfer in Fin Ribbed Radiator

Directory of Open Access Journals (Sweden)

Hua-Shu Dou

2015-01-01

Full Text Available This paper numerically investigates the thermal flow and heat transfer by natural convection in a cavity fixed with a fin array. The computational domain consists of both solid (copper and fluid (air areas. The finite volume method and the SIMPLE scheme are used to simulate the steady flow in the domain. Based on the numerical results, the energy gradient function K of the energy gradient theory is calculated. It is observed from contours of the temperature and energy gradient function that the position where thermal instability takes place correlates well with the region of large K values, which demonstrates that the energy gradient method reveals the physical mechanism of the flow instability. Furthermore, the effects of the fin height, the fin number, and the fin shape on the heat transfer rate are also investigated. It is found that the thermal performance of the fin array is determined by the combined effect of the fin space and fin height. It is also observed that the effect of fin shape on heat transfer is insignificant.

Species composition of the genus Saprolegnia in fin fish aquaculture environments, as determined by nucleotide sequence analysis of the nuclear rDNA ITS regions.

Science.gov (United States)

de la Bastide, Paul Y; Leung, Wai Lam; Hintz, William E

2015-01-01

The ITS region of the rDNA gene was compared for Saprolegnia spp. in order to improve our understanding of nucleotide sequence variability within and between species of this genus, determine species composition in Canadian fin fish aquaculture facilities, and to assess the utility of ITS sequence variability in genetic marker development. From a collection of more than 400 field isolates, ITS region nucleotide sequences were studied and it was determined that there was sufficient consistent inter-specific variation to support the designation of species identity based on ITS sequence data. This non-subjective approach to species identification does not rely upon transient morphological features. Phylogenetic analyses comparing our ITS sequences and species designations with data from previous studies generally supported the clade scheme of Diéguez-Uribeondo et al. (2007) and found agreement with the molecular taxonomic cluster system of Sandoval-Sierra et al. (2014). Our Canadian ITS sequence collection will thus contribute to the public database and assist the clarification of Saprolegnia spp. taxonomy. The analysis of ITS region sequence variability facilitated genus- and species-level identification of unknown samples from aquaculture facilities and provided useful information on species composition. A unique ITS-RFLP for the identification of S. parasitica was also described. Copyright © 2014 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Application of homotopy analysis method and inverse solution of a rectangular wet fin

International Nuclear Information System (INIS)

Panda, Srikumar; Bhowmik, Arka; Das, Ranjan; Repaka, Ramjee; Martha, Subash C.

2014-01-01

Highlights: • Solution of a wet fin with is obtained by homotopy analysis method (HAM). • Present HAM results have been well-validated with literature results. • Inverse analysis is done using genetic algorithm. • Measurement error of ±10–12% (approx.) is found to yield satisfactory reconstructions. - Abstract: This paper presents the analytical solution of a rectangular fin under the simultaneous heat and mass transfer across the fin surface and the fin tip, and estimates the unknown thermal and geometrical configurations of the fin using inverse heat transfer analysis. The local temperature field is obtained by using homotopy analysis method for insulated and convective fin tip boundary conditions. Using genetic algorithm, the thermal and geometrical parameters, viz., thermal conductivity of the material, surface heat transfer coefficient and dimensions of the fin have been simultaneously estimated for the prescribed temperature field. Earlier inverse studies on wet fin have been restricted to the analysis of nonlinear governing equation with either insulated tip condition or finite tip temperature only. The present study developed a closed-form solution with the consideration of nonlinearity effects in both governing equation and boundary condition. The study on inverse optimization leads to many feasible combination of fin materials, thermal conditions and fin dimensions. Thus allows the flexibility for designing a fin under wet conditions, based on multiple combinations of fin materials, fin dimensions and thermal configurations to achieve the required heat transfer duty. It is further determined that the allowable measurement error should be limited to ±10–12% in order to achieve satisfactory reconstruction

Dry/wet performance of a plate-fin air-cooled heat exchanger with continuous corrugated fins

International Nuclear Information System (INIS)

Hauser, S.G.; Kreid, D.K.; Johnson, B.M.

1981-01-01

The performance and operating characteristics of a plate-fin heat exchanger in dry/wet or deluge operations was experimentally determined. Development of the deluge heat/mass transfer model continued. The experiments were conducted in a specially-designed wind tunnel at the PNL. Air that was first heated and humidified to specified conditions was circulated at a controlled rate through a 2 ft x 6 ft heat exchanger module. The heat exchanger used in the tests was a wavy surface, plate fin on tube configuration. Hot water was circulated through the tubes at high flow rates to maintain an essentially isothermal condition on the tube side. Deionized water sprayed on the top of the vertically oriented plate fins was collected at the bottom of the core and recirculated. Instrumentation was provided for measurement of flow rates and thermodynamic conditions in the air, in the core circulation water, and in the deluge water. Measurements of the air side pressure drop and heat rejection rate were made as a function of air flow rate, air inlet temperature and humidity, deluge water flow rate, and the core inclination from the vertical. An overall heat transfer coefficient and an effective deluge film convective coefficient was determined. The deluge model, for predicting heat transfer from a wet finned heat exchanger was further developed and refined, and a major extension of the model was formulated that permits simultaneous calculation of both the heat transfer and evaporation rates from the wetted surface. The experiments showed an increase in the heat rejection rate due to wetting, accompanied by a proportional increase in the air side pressure drop. For operation at the same air side pressure drop, the enhancement ratio Q/sub w//Q/sub d/ varied between 2 and 5 for the conditions tested. Thus, the potential enhancement of heat transfer due to wetting can be substantial

Heat transfer from rotating finned heat exchangers with different orientation angles

Energy Technology Data Exchange (ETDEWEB)

Tawfik, Adel Abdalla [Suez Canal University, Marine Engineering and Naval Architecture Department, Faculty of Engineering, Port Said (Egypt)

2010-03-15

The local and average heat transfer characteristics of spoke like fins that extend outward from a rotating shaft have been determined experimentally. The experiments encompassed a number of geometrical parameters, including the length and chord of the fins, the number of fins deployed around the circumference of the shaft and the orientation angles of the fin. The experiments cover a wider range of rotational speeds, which varies from 25 up to 2,000 rpm. Three wire heat flux sensors have been used in conjunction with a slip ring apparatus to evaluate the local and average heat transfer coefficients. The output results indicated that, the heat transfer transition on rotating fins occurs at Reynolds number lower than encountered on the stationary rectangular fins in crossflow. In general, with non zero incidence angle, the rotating system acts as a fan and creates axial air motion, which enhance the heat transfer rate. However, the effect of orientation angle reduces with increasing the rotational speed. The Nusselt number data are independent of the number of fins in the circumferential array at high rotational speed and are weakly dependent at low Reynolds numbers. To facilitate the use of the results for design, correlations were developed which represent the fin heat transfer coefficient as a continuous function of the investigated independent parameters. (orig.)

Heat transfer and pressure drop characteristics of the tube bank fin heat exchanger with fin punched with flow redistributors and curved triangular vortex generators

Science.gov (United States)

Liu, Song; Jin, Hua; Song, KeWei; Wang, LiangChen; Wu, Xiang; Wang, LiangBi

2017-10-01

The heat transfer performance of the tube bank fin heat exchanger is limited by the air-side thermal resistance. Thus, enhancing the air-side heat transfer is an effective method to improve the performance of the heat exchanger. A new fin pattern with flow redistributors and curved triangular vortex generators is experimentally studied in this paper. The effects of the flow redistributors located in front of the tube stagnation point and the curved vortex generators located around the tube on the characteristics of heat transfer and pressure drop are discussed in detail. A performance comparison is also carried out between the fins with and without flow redistributors. The experimental results show that the flow redistributors stamped out from the fin in front of the tube stagnation points can decrease the friction factor at the cost of decreasing the heat transfer performance. Whether the combination of the flow redistributors and the curved vortex generators will present a better heat transfer performance depends on the size of the curved vortex generators. As for the studied two sizes of vortex generators, the heat transfer performance is promoted by the flow redistributors for the fin with larger size of vortex generators and the performance is suppressed by the flow redistributors for the fin with smaller vortex generators.

Control characteristics for wrap-around fins on cruise missiles configurations

Science.gov (United States)

Sawyer, W. C.; Monta, W. J.; Carter, W. V.; Alexander, W. K.

1981-01-01

This paper presents selected results of a panel loads study conducted as part of the final phase of an extensive investigation of an air-breathing missile concept employing wrap-around aerodynamic surfaces. Typical results for M = 2.36 are presented for the fin load results, plus a brief review of basic results of the previously reported tests. Vapor screen results are also discussed. The present results indicate that the fin load characteristics are nearly identical for planar and curved fins having the same projected planform and would permit the use of planar-surface predictions for supersonic speeds in the preliminary design stages of missiles employing wrap-around curved fins.

Thermal analysis of annular fins with temperature-dependent thermal properties

Institute of Scientific and Technical Information of China (English)

I. G. AKSOY

2013-01-01

The thermal analysis of the annular rectangular profile fins with variable thermal properties is investigated by using the homotopy analysis method (HAM). The thermal conductivity and heat transfer coefficient are assumed to vary with a linear and power-law function of temperature, respectively. The effects of the thermal-geometric fin parameter and the thermal conductivity parameter variations on the temperature distribution and fin efficiency are investigated for different heat transfer modes. Results from the HAM are compared with numerical results of the finite difference method (FDM). It can be seen that the variation of dimensionless parameters has a significant effect on the temperature distribution and fin efficiency.

Characteristics of a micro-fin evaporator: Theoretical analysis and experimental verification

Directory of Open Access Journals (Sweden)

Zheng Hui-Fan

2013-01-01

Full Text Available A theoretical analysis and experimental verification on the characteristics of a micro-fin evaporator using R290 and R717 as refrigerants were carried out. The heat capacity and heat transfer coefficient of the micro-fin evaporator were investigated under different water mass flow rate, different refrigerant mass flow rate, and different inner tube diameter of micro-fin evaporator. The simulation results of the heat transfer coefficient are fairly in good agreement with the experimental data. The results show that heat capacity and the heat transfer coefficient of the micro-fin evaporator increase with increasing logarithmic mean temperature difference, the water mass flow rate and the refrigerant mass flow rate. Heat capacity of the micro-fin evaporator for diameter 9.52 mm is higher than that of diameter 7.00 mm with using R290 as refrigerant. Heat capacity of the micro-fin evaporator with using R717 as refrigerant is higher than that of R290 as refrigerant. The results of this study can provide useful guidelines for optimal design and operation of micro-fin evaporator in its present or future applications.

Pectoral fin contact as a mechanism for social bonding among dolphins

Science.gov (United States)

Dudzinski, Kathleen; Ribic, Christine

2017-01-01

Bottlenose dolphins are large-brained social mammals residing in a fission-fusion society with relationships that are established and maintained over decades. We examined a decade-long data set of inter-individual pectoral fin contact exchanges to better understand how dolphins share information via tactile contact. Sex and age are significant factors in pectoral fin contact within non-kin dolphin dyads. Adult females shared more pectoral fin contacts with other adult females, while younger females showed no pattern of contact. Males shared more pectoral fin contacts with other males as juveniles and as adults, but showed no difference in the number of touches versus rubs as pectoral fin contacts with other males. Whether in the role of initiator as rubber or initiator as rubbee, male dolphins again preferred other males. These results support the notion that dolphins, especially male dolphins, might use pectoral fin contact as one tool in their repertoire for social bonding to establish, maintain and manage their inter-individual relationships. Additionally, it is also likely that the exchange of pectoral fin contact is developed and refined as individuals age, mature socially, and establish their place within a fission-fusion society.

Enhancement of heat transfer. The performance of micro-fin tubes

International Nuclear Information System (INIS)

Muzzio, A.

2001-01-01

Micro-fin tubes are characterised by numerous, very small integral fins that spiral down the inner surface. A very interesting feature of their performance in flow boiling and condensation is a large heat transfer enhancement accompanied by a low pressure drop penalty. This paper presents a general overview of micro-fin tubes and of their performance in evaporation, condensation and single-phase flow [it

Mechanism of tonal noise generation from circular cylinder with spiral fin

Science.gov (United States)

Yamashita, Ryo; Hayashi, Hidechito; Okumura, Tetsuya; Hamakawa, Hiromitsu

2014-12-01

The pitch of the spiral finned tube influences seriously to the acoustic resonance in the heat exchanger. In this research, the flow characteristics in relating to the aeolian tone from the finned cylinder are studied by the numerical simulation. It is observed that the tonal noise generated from the finned tube at two pitch spaces. The ratio of the fin pitch to the cylinder diameter is changed at 0.11 and 0.27. The tone level increases and the frequency decreases with the pitch shorter. The separation flow from the cylinder generates the span-wise vortices, Karman vortices, and the separation flow from the fin generates the stream-wise vortices. When the fin pitch ratio is small, the stream-wise vortices line up to span-wise and become weak rapidly. Only the Karman vortices are remained and integrate in span. So the Karman vortex became large. This causes the low frequency and the large aeolian tone.

Fgf16 is essential for pectoral fin bud formation in zebrafish

International Nuclear Information System (INIS)

Nomura, Ryohei; Kamei, Eriko; Hotta, Yuuhei; Konishi, Morichika; Miyake, Ayumi; Itoh, Nobuyuki

2006-01-01

Zebrafish pectoral fin bud formation is an excellent model for studying morphogenesis. Fibroblast growth factors (Fgfs) and sonic hedgehog (shh) are essential for pectoral fin bud formation. We found that Fgf16 was expressed in the apical ectodermal ridge (AER) of fin buds. A knockdown of Fgf16 function resulted in no fin bud outgrowth. Fgf16 is required for cell proliferation and differentiation in the mesenchyme and the AER of the fin buds, respectively. Fgf16 functions downstream of Fgf10, a mesenchymal factor, signaling to induce the expression of Fgf4 and Fgf8 in the AER. Fgf16 in the AER and shh in the zone of polarizing activity (ZPA) interact to induce and/or maintain each other's expression. These findings have revealed that Fgf16, a newly identified AER factor, plays a crucial role in pectoral fin bud outgrowth by mediating the interactions of AER-mesenchyme and AER-ZPA

Ontogenetic scaling of caudal fin shape in Squalus acanthias (Chondrichthyes, Elasmobranchii): a geometric morphometric analysis with implications for caudal fin functional morphology.

Science.gov (United States)

Reiss, Katie L; Bonnan, Matthew F

2010-07-01

The shark heterocercal caudal fin and its contribution to locomotion are of interest to biologists and paleontologists. Current hydrodynamic data show that the stiff dorsal lobe leads the ventral lobe, both lobes of the tail are synchronized during propulsion, and tail shape reflects its overall locomotor function. Given the difficulties surrounding the analysis of shark caudal fins in vivo, little is known about changes in tail shape related to ontogeny and sex in sharks. A quantifiable analysis of caudal fin shape may provide an acceptable proxy for inferring gross functional morphology where direct testing is difficult or impossible. We examined ontogenetic and sex-related shape changes in the caudal fins of 115 Squalus acanthias museum specimens, to test the hypothesis that significant shape changes in the caudal fin shape occur with increasing size and between the sexes. Using linear and geometric morphometrics, we examined caudal shape changes within the context of current hydrodynamic models. We found no statistically significant linear or shape difference between sexes, and near-isometric scaling trends for caudal dimensions. These results suggest that lift and thrust increase linearly with size and caudal span. Thin-plate splines results showed a significant allometric shape change associated with size and caudal span: the dorsal lobe elongates and narrows, whereas the ventral lobe broadens and expands ventrally. Our data suggest a combination of caudal fin morphology with other body morphology aspects, would refine, and better elucidate the hydrodynamic factors (if any) that underlie the significant shape changes we report here for S. acanthias.

High temperature mechanical properties on multi stage blazed fin body with ultra fine off-set fin for compact heat exchanger

International Nuclear Information System (INIS)

Ishiyama, Shintaro; Muto, Yasushi

2003-01-01

Three stage blazed plate fin body with ultra fine off-set fin (thickness x height x pitch x off-set pitch = 0.22 mm x 1.2 mm x 1.6 mm x 5 mm) for 600 MWt High Temperature Gas Cooled Reactor Gas Turbin (HTGR-GT) system was fabricated and tested on its high temperature mechanical properties and the following results were derived. (1) tested body shows almost the same strength an fatigue behavior of SUS 304 as main structural material at elevated temperatures up to 873 K, (2) static and fatigue fracture mainly occurred at ultra fine off-set and (3) high temperature strength and fatigue life are improved by blazing technique to double side walls of the fin by Ni blaze material. (author)

Fish Swimming and Bird/Insect Flight

Science.gov (United States)

Wu, Theodore Yaotsu

2011-01-01

This expository review is devoted to fish swimming and bird/insect flight. (a) The simple waving motion of an elongated flexible ribbon plate of constant width propagating a wave distally down the plate to swim forward in a fluid, initially at rest, is first considered to provide a fundamental concept on energy conservation. It is generalized to include variations in body width and thickness, with appended dorsal, ventral and caudal fins shedding vortices to closely simulate fish swimming, for which a nonlinear theory is presented for large-amplitude propulsion. (b) For bird flight, the pioneering studies on oscillatory rigid wings are discussed with delineating a fully nonlinear unsteady theory for a two-dimensional flexible wing with arbitrary variations in shape and trajectory to provide a comparative study with experiments. (c) For insect flight, recent advances are reviewed by items on aerodynamic theory and modeling, computational methods, and experiments, for forward and hovering flights with producing leading-edge vortex to yield unsteady high lift. (d) Prospects are explored on extracting prevailing intrinsic flow energy by fish and bird to enhance thrust for propulsion. (e) The mechanical and biological principles are drawn together for unified studies on the energetics in deriving metabolic power for animal locomotion, leading to the surprising discovery that the hydrodynamic viscous drag on swimming fish is largely associated with laminar boundary layers, thus drawing valid and sound evidences for a resounding resolution to the long-standing fish-swim paradox proclaimed by Gray (1936, 1968 ).

Does the water reuse affect the fish growth, welfare quality?

Directory of Open Access Journals (Sweden)

Štěpán Lang

2012-01-01

Full Text Available The fish production in aquaculture is growing from year to year. However capacities of current aquaculture facilities are limited. So the need of intensification of old facilities and building new intensive facilities is obvious. The high intensity of fish culture generates some questions. Could water reuse affect fish growth, welfare, health or quality of final product? A lot of research was performed for this issue but just a few works compared water reuse systems (RAS versus flow thru systems (FTS. A problem with CO2 oversaturation was solved by shallow diffusers. Fin erosion seems to be a problem of high stocking density and system hygienic but it is not related directly to water reuse. A few papers were written about biochemical blood stress markers but it was mostly aimed to acute crowding or changes were found at extreme stocking densities over 124 kg.m3 for rainbow trout and 70 kg.m3 for sea bass. The fish are able to accustom to increased noise produced by RAS equipment very fast so it don’t affect fish negatively. There wasn’t found any prove of main water reuse to fish influence in the available literature. All results indicates that if the ecological parameters are kept in natural range for the fish reared in RAS, there is no negative effect of water reuse on fish.

Fundamental constraints in synchronous muscle limit superfast motor control in vertebrates

DEFF Research Database (Denmark)

Mead, Andrew F; Osinalde, Nerea; Ørtenblad, Niels

2017-01-01

that all known SFMs share multiple functional adaptations that minimize excitation-contraction coupling transduction times. Our results suggest that SFM evolved independently in sound-producing organs in ray-finned fish, birds, and mammals, and that SFM phenotypes operate at a maximum operational speed set...

Effects of fin shape on condensation in herringbone microfin tubes

Energy Technology Data Exchange (ETDEWEB)

Miyara, Akio [Saga University (Japan). Dept. of Mechanical Engineering; Otsubo, Yusuke; Ohtsuka, Satoshi; Mizuta, Yoshihiko [Saga University (Japan). Graduate School of Science and Engineering

2003-06-01

Effects of fin height and helix angle on condensation inside a herringbone microfin tube have been experimentally investigated with five types of herringbone microfin tubes. Heat transfer coefficients are about 2-4 times higher than that of the helical microfin tube under high mass velocity conditions. In the low mass velocity, they are equal to that of the helical microfin tube. The heat transfer enhancement increases with fin height up to 0.18 mm; higher fin heights show enhancement values similar to the 0.18 mm results. Pressure drop increases with the fin height. Larger helix angle yields higher heat transfer and higher pressure drop. For the lowest fin and/or smallest helix angle, the pressure drop is comparable with that of the helical microfin tube, while the heat transfer enhancement is higher. The enhancement mechanism is discussed from flow pattern observations. Effect of mass transfer resistance for R410A is estimated and negligible effects have been proved. (author)

Development of a Simulation Model for Swimming with Diving Fins

Directory of Open Access Journals (Sweden)

Motomu Nakashima

2018-02-01

Full Text Available The simulation model to assess the performance of diving fin was developed by extending the swimming human simulation model SWUM. A diving fin was modeled as a series of five rigid plates and connected to the human model by springs and dampers. These plates were connected to each other by virtual springs and dampers, and fin’s bending property was represented by springs and dampers as well. An actual diver’s swimming motion with fins was acquired by a motion capture experiment. In order to determine the bending property of the fin, two bending tests on land were conducted. In addition, an experiment was conducted in order to determine the fluid force coefficients in the fluid force model for the fin. Finally, using all measured and identified information, a simulation, in which the experimental situation was reproduced, was carried out. It was confirmed that the diver in the simulation propelled forward in the water successfully.

En Defensa del Fin de Lucro en Salud.

Directory of Open Access Journals (Sweden)

Ramón Abel Castaño Yepes

2007-06-01

La quinta premisa se deriva de la cuarta y de la segunda, es decir, que si el diseño del sistema de salud introducido por la Ley 100 tiene como elemento distintivo el fin de lucro, entonces el resultado de dicho diseño tiene que ser indeseable, puesto que el fin de lucro es indeseable...

Effects of the partially movable control fin with end plate of underwater vehicle

Directory of Open Access Journals (Sweden)

Chul-Min Jung

2017-01-01

Full Text Available Underwater torpedo has control fin with very low aspect ratio due to launching from limited size of cylindrical torpedo tube. If the aspect ratio of control fin of underwater vehicle is very low three-dimensional flow around control fin largely reduces control forces. In this study, the end plate was applied to reduce the three-dimensional flow effects of partially movable control fin of underwater vehicle. Through numerical simulations the flow field around control fin was examined with and without end plate for different flap angles. The pressure, vorticity, lift and torque on the control fin were analyzed and compared to experiments. The comparison have shown a reasonable agreement between numerical and experimental results and the effect of end plate on a low aspect ratio control fin. When the end plate was attached to the movable control fin, the lift increased and the actuator shaft torque did not significantly change. As this means less consumption of the actuator shaft torque compared to the control fin that has the same control force, the inner actuator capacity can be reduced and energy consumption can be saved. Considering this, it is expected to be effectively applied to the control fin design of underwater vehicles such as torpedoes.

An experimental investigation into the deployment of 3-D, finned wing and shape memory alloy vortex generators in a forced air convection heat pipe fin stack

International Nuclear Information System (INIS)

Aris, M.S.; McGlen, R.; Owen, I.; Sutcliffe, C.J.

2011-01-01

Forced air convection heat pipe cooling systems play an essential role in the thermal management of electronic and power electronic devices such as microprocessors and IGBT's (Integrated Gate Bipolar Transistors). With increasing heat dissipation from these devices, novel methods of improving the thermal performance of fin stacks attached to the heat pipe condenser section are required. The current work investigates the use of a wing type surface protrusions in the form of 3-D delta wing tabs adhered to the fin surface, thin wings punched-out of the fin material and TiNi shape memory alloy delta wings which changed their angles of attack based on the fin surface temperature. The longitudinal vortices generated from the wing designs induce secondary mixing of the cooler free stream air entering the fin stack with the warmer fluid close to the fin surfaces. The change in angle of the attack of the active delta wings provide heat transfer enhancement while managing flow pressure losses across the fin stack. A heat transfer enhancement of 37% compared to a plain fin stack was obtained from the 3-D tabs in a staggered arrangement. The punched-out delta wings in the staggered and inline arrangements provided enhancements of 30% and 26% respectively. Enhancements from the active delta wings were lower at 16%. However, as these devices reduce the pressure drop through the fin stack by approximately 19% in the de-activate position, over the activated position, a reduction in fan operating cost may be achieved for systems operating with inlet air temperatures below the maximum inlet temperature specification for the device. CFD analysis was also carried out to provide additional detail of the local heat transfer enhancement effects. The CFD results corresponded well with previously published reports and were consistent with the experimental findings. - Highlights: → Heat transfer enhancements of heat pipe fin stacks was successfully achieved using fixed and active delta

Simulation study of a 3-D device integrating FinFET and UTBFET

KAUST Repository

Fahad, Hossain M.; Hu, Chenming; Hussain, Muhammad Mustafa

2015-01-01

By integrating 3-D nonplanar fins and 2-D ultrathin bodies, wavy FinFETs merge two formerly competing technologies on a silicon-on-insulator platform to deliver enhanced transistor performance compared with conventional trigate Fin

Numerical studies of static aeroelastic effects on grid fin aerodynamic performances

Directory of Open Access Journals (Sweden)

Chengde HUANG

2017-08-01

Full Text Available The grid fin is an unconventional control surface used on missiles and rockets. Although aerodynamics of grid fin has been studied by many researchers, few considers the aeroelastic effects. In this paper, the static aeroelastic simulations are performed by the coupled viscous computational fluid dynamics with structural flexibility method in transonic and supersonic regimes. The developed coupling strategy including fluid–structure interpolation and volume mesh motion schemes is based on radial basis functions. Results are presented for a vertical and a horizontal grid fin mounted on a body. Horizontal fin results show that the deformed fin is swept backward and the axial force is increased. The deformations also induce the movement of center of pressure, causing the reduction and reversal in hinge moment for the transonic flow and the supersonic flow, respectively. For the vertical fin, the local effective incidences are increased due to the deformations so that the deformed normal force is greater than the original one. At high angles of attack, both the deformed and original normal forces experience a sudden reduction due to the interference of leeward separated vortices on the fin. Additionally, the increment in axial force is shown to correlate strongly with the increment in the square of normal force.

Integrated Rudder/Fin Concise Control Based on Frequency Domain Analysis

OpenAIRE

W. Guan; Z. J. Su; G. Q. Zhang

2013-01-01

This paper describes a concise robust controller design of integrated rudder and fin control system in use of the closed loop gain shaping algorithm (CGSA) strategy. Compared with the arbitrary selection of weighting function in integrated rudder and fin H∞ mixed sensitivity control design procedures, the CGSA methods provided a relatively more straightforward and concise design method. Simulations were described that the overall performance of each CGSA rudder and fin control loop and the in...

Gene expression profiles of fin regeneration in loach (Paramisgurnus dabryanu).

Science.gov (United States)

Li, Li; He, Jingya; Wang, Linlin; Chen, Weihua; Chang, Zhongjie

2017-11-01

Teleost fins can regenerate accurate position-matched structure and function after amputation. However, we still lack systematic transcriptional profiling and methodologies to understand the molecular basis of fin regeneration. After histological analysis, we established a suppression subtraction hybridization library containing 418 distinct sequences expressed differentially during the process of blastema formation and differentiation in caudal fin regeneration. Genome ontology and comparative analysis of differential distribution of our data and the reference zebrafish genome showed notable subcategories, including multi-organism processes, response to stimuli, extracellular matrix, antioxidant activity, and cell junction function. KEGG pathway analysis allowed the effective identification of relevant genes in those pathways involved in tissue morphogenesis and regeneration, including tight junction, cell adhesion molecules, mTOR and Jak-STAT signaling pathway. From relevant function subcategories and signaling pathways, 78 clones were examined for further Southern-blot hybridization. Then, 17 genes were chosen and characterized using semi-quantitative PCR. Then 4 candidate genes were identified, including F11r, Mmp9, Agr2 and one without a match to any database. After real-time quantitative PCR, the results showed obvious expression changes in different periods of caudal fin regeneration. We can assume that the 4 candidates, likely valuable genes associated with fin regeneration, deserve additional attention. Thus, our study demonstrated how to investigate the transcript profiles with an emphasis on bioinformatics intervention and how to identify potential genes related to fin regeneration processes. The results also provide a foundation or knowledge for further research into genes and molecular mechanisms of fin regeneration. Copyright © 2017 Elsevier B.V. All rights reserved.

Comprehensive performance comparison of airfoil fin PCHEs with NACA 00XX series airfoil

Energy Technology Data Exchange (ETDEWEB)

Chen, Fei, E-mail: chenfei@iet.cn [Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190 (China); Heating Technology Research and Development Center, Beijing District Heating Group, Beijing 100028 (China); Zhang, Lishen, E-mail: lishenzhang@sina.com [Heating Technology Research and Development Center, Beijing District Heating Group, Beijing 100028 (China); Huai, Xiulan, E-mail: hxl@iet.cn [Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190 (China); Li, Jufeng, E-mail: lijufeng.net@163.com [Nuclear and Radiation Safety Center, Ministry of Environmental Protection, Beijing 100082 (China); Zhang, Hang, E-mail: zhanghang@iet.cn [Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190 (China); Liu, Zhigang, E-mail: zgliu9322@163.com [Energy Research Institute of Shandong Academy of Sciences, Jinan, Shandong 250014 (China)

2017-04-15

Highlights: • Pressure drop of NACA 0020 airfoil fin PCHE reduces strikingly in comparison with the zigzag PCHE. • Pressure drop of NACA 00XX airfoil fin PCHE decreases as airfoil thickness increases. • Heat transfer performance of NACA 00XX airfoil fin PCHE increases as airfoil thickness rises. • Comprehensive performance of NACA 00XX airfoil fin PCHE degrades as airfoil thickness increases. - Abstract: Printed circuit heat exchanger (PCHE) can be used in supercritical carbon dioxide (S-CO{sub 2}) Brayton cycle. The present study compares NACA 0020 airfoil fin PCHE with conventional zigzag PCHE by numerical analysis. Pressure drop of the former has a striking reduction while maintaining excellent heat transfer performance. Comparison on four NACA 00XX series airfoil fin PCHEs is performed to investigate the influence of airfoil profile on flow and heat transfer performance. With a fixed vertical pitch, heat transfer performance of NACA series airfoil fin PCHE increases as airfoil thickness increases. However, comprehensive performance, in which both flow and heat transfer are taken into account, degrades with increasing airfoil thickness. Among four NACA airfoil fin PCHEs presented in this paper, NACA 0010 airfoil fin PCHE demonstrates the best comprehensive performance.

Comprehensive performance comparison of airfoil fin PCHEs with NACA 00XX series airfoil

International Nuclear Information System (INIS)

Chen, Fei; Zhang, Lishen; Huai, Xiulan; Li, Jufeng; Zhang, Hang; Liu, Zhigang

2017-01-01

Highlights: • Pressure drop of NACA 0020 airfoil fin PCHE reduces strikingly in comparison with the zigzag PCHE. • Pressure drop of NACA 00XX airfoil fin PCHE decreases as airfoil thickness increases. • Heat transfer performance of NACA 00XX airfoil fin PCHE increases as airfoil thickness rises. • Comprehensive performance of NACA 00XX airfoil fin PCHE degrades as airfoil thickness increases. - Abstract: Printed circuit heat exchanger (PCHE) can be used in supercritical carbon dioxide (S-CO_2) Brayton cycle. The present study compares NACA 0020 airfoil fin PCHE with conventional zigzag PCHE by numerical analysis. Pressure drop of the former has a striking reduction while maintaining excellent heat transfer performance. Comparison on four NACA 00XX series airfoil fin PCHEs is performed to investigate the influence of airfoil profile on flow and heat transfer performance. With a fixed vertical pitch, heat transfer performance of NACA series airfoil fin PCHE increases as airfoil thickness increases. However, comprehensive performance, in which both flow and heat transfer are taken into account, degrades with increasing airfoil thickness. Among four NACA airfoil fin PCHEs presented in this paper, NACA 0010 airfoil fin PCHE demonstrates the best comprehensive performance.

Necropsy report of a fin whale (Balaenoptera physalus) stranded in Denmark in 2010

DEFF Research Database (Denmark)

Alstrup, Aage K. O.; Hedayat, Abdi; Jensen, Trine Hammer

2013-01-01

There is little detailed information on stranded fin whales (Balaenoptera physalus) in the scientific literature (Notarbartolo di Sciara et al., 2003). In Denmark, at least eight fin whales stranded between the years 1603 and 1958 (Kinze, 1995). On 16 June 2010, a live subadult or adult male fin...... whale stranded in the Bay of Vejle (55º 69' N, 9º 58' E), Denmark. Despite several attempts, it was not possible to rescue the fin whale, which was only partially exposed by the water. The fin whale succumbed after 5 d stranded in shallow water. The dead fin whale was transported to a nearby pier...

FIN5 positively regulates far-red light responses in Arabidopsis thaliana

International Nuclear Information System (INIS)

Cho, D.S.; Hong, S.H.; Nam, H.G.; Soh, M.S.

2003-01-01

We report the characterization of a semi-dominant mutation fin5-1 (far-red insensitive 5-1) of Arabidopsis, which was isolated from genetic screening of phytochrome A (phyA) signaling components. Plants with the fin5-1 mutation exhibited a long hypocotyl phenotype when grown under far-red (FR) light, but not under red light. Physiological analyses implied that FIN5 might be differentially involved in diverse responses that are regulated by phyA under continuous FR light. Anthocyanin accumulation, gravitropic response of hypocotyl growth, and FR light-preconditioned blocking of greening were also impaired in the fin5-1 mutant, whereas photoperiodic floral induction was not, if at all, significantly affected. Moreover, light-regulated expression of the CHS, PORA and PsbS genes was attenuated in fin5-1 mutant plants, while the light-induced expression of CAB was normal. The mutation exhibited semi-dominance regarding control of hypocotyl growth in FR light. We suggest that FIN5 defines a novel branch in the network of phyA signaling in Arabidopsis. (author)

新加坡FinTech生态系统建设及其启示%Singapore’s FinTech Ecological System Construction and Its Enlightenment

Institute of Scientific and Technical Information of China (English)

钟鸣长

2016-01-01

Since the financial crisis, the integration of finance and technology has become a new trend in global economic development, and become a hot issue in the political, business, and academic attention. Singapore government maps out a strategy and introduces a series of policies to build FinTech ecosystem, such as financial support, establishing FinTech SUB, and implementing regulatory sandbox. Thus, Singapore will transform the existing financial system, construct the FinTech hub, and become an intelligent country of S&T and intelligent financial center. However, Internet finance in China is still at the stage of FinTech1.0 currently, which appears to be fast, slant, and disordered. So it is urgent to be transformed and upgraded. Meanwhile, we should not only be fully aware of the necessity and urgency of FinTech ecosystem development, clarify the relation between Internet financial and FinTech, but also we should learn from Singapore’s advanced experience to develop the FinTech ecosystem in all aspects, for example, setting up specialized management institutions, determining specific development goals, providing financial support, promoting “Regulatory Sandbox”, mobilizing domestic and international market resources, and exerting the role of the government, market, and enterprises.%金融危机以来，金融与科技的融合成为全球经济发展的一股新潮流和趋势，成为政、商、学界关注的热点话题。新加坡从资金支持、搭建创业加速平台、推行监管沙盒等方面推出了打造FinTech生态系统的组合拳，旨在改造现有金融体系、建设FinTech枢纽中心，立志成为世界智慧科技大国和智慧金融中心。中国互联网金融目前总体上还处于FinTech1.0阶段，呈现一种“快、偏、乱”的现象，亟需转型与升级。因此，我们不仅要充分意识到FinTech产业发展的必要性和紧迫性，厘清互联网金融与Fin

The performance of a new gas to gas heat exchanger with strip fin

NARCIS (Netherlands)

Wang, J.; Hirs, Gerard; Rollmann, P.

1999-01-01

A compact gas to gas heat exchanger needs large heat transfer areas on both fluid sides. This can be realised by adding secondary surfaces. The secondary surfaces are plate fin, strip fin, and louvered fin, etc. The fins extend the heat transfer surfaces and promote turbulence. This paper presents a

Robotic Pectoral Fin Thrust Vectoring Using Weighted Gait Combinations

Directory of Open Access Journals (Sweden)

John S. Palmisano

2012-01-01

Full Text Available A method was devised to vector propulsion of a robotic pectoral fin by means of actively controlling fin surface curvature. Separate flapping fin gaits were designed to maximize thrust for each of three different thrust vectors: forward, reverse, and lift. By using weighted combinations of these three pre-determined main gaits, new intermediate hybrid gaits for any desired propulsion vector can be created with smooth transitioning between these gaits. This weighted gait combination (WGC method is applicable to other difficult-to-model actuators. Both 3D unsteady computational fluid dynamics (CFD and experimental results are presented.

Heat transfer in laminar flow for a finned double - tube

International Nuclear Information System (INIS)

Colle, S.

1977-01-01

An analitical study of the steady-state heat transfer in laminar flow in finned double-tube heat exchangers is presented. The fins are plane, straight and continous, equally spaced and are fixed over the external surface of the inner tube. A constant peripheral temperature distribution is assumed to apply over the inner tube surface and each fin, and a constant peripheral heat flux is assumed to apply over the outer tube surface, while the overall heat flux is suposed to be uniform in the longitudinal direction of the duct. The prediction of the thermal performance of the finned double-tube is made by means of the relationship between the Nusselt number, the boundary conditions and the geometric characteristcs of the duct. (author) [pt

An in vivo analysis of Cr6+ induced biochemical, genotoxicological and transcriptional profiling of genes related to oxidative stress, DNA damage and apoptosis in liver of fish, Channa punctatus (Bloch, 1793).

Science.gov (United States)

Awasthi, Yashika; Ratn, Arun; Prasad, Rajesh; Kumar, Manoj; Trivedi, Sunil P

2018-07-01

Present study was designed to assess the hexavalent chromium (Cr 6+ ) mediated oxidative stress that induces DNA damage and apoptosis in adult fish, Channa punctatus (35 ± 3.0 g; 14.5 ± 1.0 cm; Actinopterygii). Fishes were maintained in three groups for 15, 30 and 45 d of exposure periods. They were treated with 5% (Group T1) and 10% (Group T2) of 96 h-LC 50 of chromium trioxide (Cr 6+ ). Controls were run for the similar duration. A significant (p < 0.05) increment in the activities of antioxidant enzymes, SOD and CAT in liver tissues of the exposed fish evinces the persistence of oxidative stress. A significant (p < 0.05) increase in induction of micronuclei (MN) coupled with transcriptional responses of target genes related to antioxidant enzymes, DNA damage and apoptosis (sod, cat, gsr, nox-1, p53, bax, bcl-2, apaf-1 and casp3a) establishes the impact of oxidative stress due to in vivo, Cr 6+ accumulation in liver as compared to control (0 mg/L), in a dose and exposure-dependent manner. Initially, the increased level of reactive oxygen species (ROS) in liver coincided with that of enhanced mRNA expression of antioxidant enzymes, sod, cat, gsr and nox-1 but, later, the overproduction of ROS, after 45 d of exposure of Cr 6+ , resulted in a significant (p < 0.05) up-regulation of p53. Our findings also unveil that the up-regulation of bax, apaf-1 and casp3a and down-regulation of bcl-2 are associated with Cr 6+ -induced oxidative stress mediated-apoptosis in liver of test fish. Aforesaid molecular markers can, thus, be efficiently utilized for bio-monitoring of aquatic regimes and conservation of fish biodiversity. Copyright © 2018 Elsevier B.V. All rights reserved.

Nurturing a FinTech Ecosystem

DEFF Research Database (Denmark)

Leong, Carmen; Tan, Barney; Xiao, Xiao

2017-01-01

Financial technology, or FinTech, involves the design and delivery of financial products and services through technology. It impacts financial institutions, regulators, customers, and merchants across a wide range of industries. Pervasive digital technologies are challenging the fundamentals...... of the highly regulated financial sector, leading to the emergence of non-traditional payment systems, peer-to-peer money exchanges and increased turbulence in currency markets. This case study explores the development of a FinTech company in China that offers microloans to college students. Five lessons...... learned are presented for organizations to better manage the challenges and to leverage the opportunities amidst the disruption of financial sector. Our findings also shed light on how digital technology 1) offers the strategic capability for a firm to occupy a market niche in financial sector, 2) enables...

Optimization of geometric parameters of heat exchange pipes pin finning

Science.gov (United States)

Akulov, K. A.; Golik, V. V.; Voronin, K. S.; Zakirzakov, A. G.

2018-05-01

The work is devoted to optimization of geometric parameters of the pin finning of heat-exchanging pipes. Pin fins were considered from the point of view of mechanics of a deformed solid body as overhang beams with a uniformly distributed load. It was found out under what geometric parameters of the nib (diameter and length); the stresses in it from the influence of the washer fluid will not exceed the yield strength of the material (aluminum). Optimal values of the geometric parameters of nibs were obtained for different velocities of the medium washed by them. As a flow medium, water and air were chosen, and the cross section of the nibs was round and square. Pin finning turned out to be more than 3 times more compact than circumferential finning, so its use makes it possible to increase the number of fins per meter of the heat-exchanging pipe. And it is well-known that this is the main method for increasing the heat transfer of a convective surface, giving them an indisputable advantage.

Numerical simulation of natural convection in annuli with internal fins

International Nuclear Information System (INIS)

Ha, Man Yeong; Kim, Joo Goo

2004-01-01

The solution for the natural convection in internally finned horizontal annuli is obtained by using a numerical simulation of time-dependent and two-dimensional governing equations. The fins existing in annuli influence the flow pattern, temperature distribution and heat transfer rate. The variations of the fin configuration suppress or accelerate the free convective effects compared to those of the smooth tubes. The effects of fin configuration, number of fins and ratio of annulus gap width to the inner cylinder radius on the fluid flow and heat transfer in annuli are demonstrated by the distribution of the velocity vector, isotherms and streamlines. The governing equations are solved efficiently by using a parallel implementation. The technique is adopted for reduction of the computation cost. The parallelization is performed with the domain decomposition technique and message passing between sub-domains on the basis of the MPI library. The results from parallel computation reveal in consistency with those of the sequential program. Moreover, the speed-up ratio shows linearity with the number of processor

Collector Efficiency in Downward-Type Internal-Recycle Solar Air Heaters with Attached Fins

Directory of Open Access Journals (Sweden)

Chii-Dong Ho

2013-10-01

Full Text Available The internal-recycle operation effect on collector efficiency in downward-type rectangular solar air heaters with attached fins is theoretically investigated. It is found that considerable collector efficiency is obtainable if the collector has attached fins and the operation is carried out with internal recycling. The recycling operation increases the fluid velocity to decrease the heat transfer resistance, compensating for the undesirable effect of decreasing the heat transfer driving force (temperature difference due to remixing. The attached fins provide an enlarged heat transfer area. The order of performance in a device of same size is: double pass with recycle and fins > double pass with recycle but without fins > single pass without recycle and fins.

Fin field effect transistor directionality impacts printing of implantation shapes

Science.gov (United States)

Wang, Xiren; Granik, Yuri

2018-01-01

In modern integrated circuit (IC) fabrication processes, the photoresist receives considerable illumination energy that is reflected by underlying topography during optical lithography of implantation layers. Bottom antireflective coating (BARC) is helpful to mitigate the reflection. Often, however, BARC is not used, because its removal is technically challenging, in addition to its relatively high economic cost. Furthermore, the advanced technology nodes, such as 14/10-nm nodes, have introduced fin field effect transistor (FinFET), which makes reflection from nonuniform silicon substrates exceptionally complicated. Therefore, modeling reflection from topography becomes obligatory to accurately predict printing of implantation shapes. Typically, FinFET is always fixed in one direction in realistic designs. However, the same implantation rectangle may be oriented in either horizontal or vertical direction. Then, there are two types of relations between the critical dimension (CD) and FinFET, namely a parallel-to and a perpendicular-to relation. We examine the fin directionality impact on CD. We found that this impact may be considerable in some cases. We use our in-house rigorous optical topography simulator to reveal underlining physical reasons. One of the major causes of the CD differences is that in the parallel orientation, the solid sidewalls of the fins conduct considerable light reflections unlike for the perpendicular orientation. This finding can aid the compact modeling in optical proximity correction of implantation masks.

Protective Role of Comfrey Leave Extracts on UV-induced Zebrafish Fin Damage

OpenAIRE

Cheng, Chien-Chung; Chou, Chi-Yuan; Chang, Yao-Chin; Wang, Hsuan-Wen; Wen, Chi-Chung; Chen, Yau-Hung

2014-01-01

In zebrafish, UV exposure leads to fin malformation phenotypes including fin reduction or absence. The present study evaluated UV-protective activities of comfrey leaves extracts in a zebrafish model by recording fin morphological changes. Chemopreventive effects of comfrey leave extracts were evaluated using Kaplan-Meier analysis and Cox proportional hazards regression. The results showed that (1) the mean times of return to normal fin in the UV+comfrey (50 and 100 ppm) groups were 3.43 and ...

Computational investigation of heat transfer and pressure drop in a typical louver fin-and-tube heat exchanger for various louver angles and fin pitches

Directory of Open Access Journals (Sweden)

Okbaz Abdulkerim

2017-01-01

Full Text Available In this study 3-D numerical simulations on heat transfer and pressure drop characteristics for a typical louver fin-and- double-row tube heat exchanger were carried out. The heat transfer improvement and the corresponding pressure drop amounts were investigated depending on louver angles, fin pitch and Reynolds number, and reported in terms of Colburn j-factor and Fanning friction factor f. The heat transfer improvement and the corresponding pressure drop amounts were investigated depending on louver angles between 20° ≤Ө≤ 30°, louver pitch of Lp=3.8 mm and frontal velocities of U between 1.22 m/s - 3 m/s. In addition, flow visualization of detailed flow features results, such as velocity vectors, streamlines and temperature counters have been shown to understand heat transfer enhancement mechanism. The present results indicated that louver angle and fin pitch noticeably affected the thermal and hydraulic performance of heat exchanger. It has been seen that increasing louver angle, increases thermal performance while decreasing hydraulic performance associated to pressure drop for fin pitches of 3.2 mm and 2.5 mm. Fin pitch determines the flow behaviour that for fin pitch of 2 mm, increasing louver angle decreased heat transfer and pressure drop. Velocity vectors and streamlines give considerable information about the flow whether it is duct directed or louver directed. For all conditions the flow is louver directed.

Characteristics and formation mechanism for stainless steel fiber with periodic micro-fins

Science.gov (United States)

Tang, Tao; Wan, Zhenping; Lu, Longsheng; Tang, Yong

2016-05-01

Metal fibers have been widely used in many industrial applications due to their unique advantages. In certain applications, such as catalyst supports or orthopedic implants, a rough surface or tiny outshoots on the surface of metal fibers to increase surface area are needed. However, it has not been concerned about the surface morphologies of metal fiber in the current research of metal fiber manufacturing. In this paper, a special multi-tooth tool composed of a row of triangular tiny teeth is designed. The entire cutting layer of multi-tooth tool bifurcates into several thin cutting layers due to tiny teeth involved in cutting. As a result, several stainless steel fibers with periodic micro-fins are produced simultaneously. Morphology of periodic micro-fins is found to be diverse and can be classified into three categories: unilateral plane, unilateral tapering and bilateral. There are two forming mechanisms for the micro-fins. One is that periodic burrs remained on the free side of cutting layer of a tiny tooth create micro-fins of stainless steel fiber produced by the next neighboring tiny tooth; the other is that the connections between two fibers stuck together come to be micro-fins if the two fibers are finally detached. Influence of cutting conditions on formation of micro-fins is investigated. Experimental results show that cutting depth has no significant effect on micro-fin formation, high cutting speed is conducive to micro-fin formation, and feed should be between 0.12 mm/r and 0.2 mm/r to reliably obtain stainless steel fiber with micro-fins. This research presents a new pattern of stainless steel fiber characterized by periodic micro-fins formed on the edge of fiber and its manufacturing method.

印度尼西亚FinTech生态圈的发展及机遇%Development and Opportunities of FinTech Ecosystem in Indonesia

Institute of Scientific and Technical Information of China (English)

熊琦

2018-01-01

印尼FinTech是新兴行业,自2014年以来呈现井喷式增长,其生态圈竞争优势主要体现在需求方面:潜在市场巨大,资本投入增长迅猛,但人才优势尚显不足,政策上积极学习国际经验,已推出"监管沙盒"和针对P2P的严格管控法规,从长远看能促进FinTech包容性发展;印尼银行渗透率低,银行分支机构少,物理基础设施建设不足,且印尼人的FinTech意识较弱,中国FinTech企业在印尼的个人消贷和中小企业融资领域将大有作为;可加大对印尼的资金支持以帮助当地建设,更好地进行合作发展FinTech行业,实现共赢.

Stabilization of gene expression and cell morphology after explant recycling during fin explant culture in goldfish

International Nuclear Information System (INIS)

Chenais, Nathalie; Lareyre, Jean-Jacques; Le Bail, Pierre-Yves; Labbe, Catherine

2015-01-01

The development of fin primary cell cultures for in vitro cellular and physiological studies is hampered by slow cell outgrowth, low proliferation rate, poor viability, and sparse cell characterization. Here, we investigated whether the recycling of fresh explants after a first conventional culture could improve physiological stability and sustainability of the culture. The recycled explants were able to give a supplementary cell culture showing faster outgrowth, cleaner cell layers and higher net cell production. The cells exhibited a highly stabilized profile for marker gene expression including a low cytokeratin 49 (epithelial marker) and a high collagen 1a1 (mesenchymal marker) expression. Added to the cell spindle-shaped morphology, motility behavior, and actin organization, this suggests that the cells bore stable mesenchymal characteristics. This contrast with the time-evolving expression pattern observed in the control fresh explants during the first 2 weeks of culture: a sharp decrease in cytokeratin 49 expression was concomitant with a gradual increase in col1a1. We surmise that such loss of epithelial features for the benefit of mesenchymal ones was triggered by an epithelial to mesenchymal transition (EMT) process or by way of a progressive population replacement process. Overall, our findings provide a comprehensive characterization of this new primary culture model bearing mesenchymal features and whose stability over culture time makes those cells good candidates for cell reprogramming prior to nuclear transfer, in a context of fish genome preservation. - Highlights: • Recycled fin explants outgrow cells bearing stable mesenchymal traits. • Cell production and quality is enhanced in the recycled explant culture system. • Fresh fin primary culture is highly variable and loose epithelial traits over time

Stabilization of gene expression and cell morphology after explant recycling during fin explant culture in goldfish

Energy Technology Data Exchange (ETDEWEB)

Chenais, Nathalie; Lareyre, Jean-Jacques; Le Bail, Pierre-Yves; Labbe, Catherine, E-mail: catherine.labbe@rennes.inra.fr

2015-07-01

The development of fin primary cell cultures for in vitro cellular and physiological studies is hampered by slow cell outgrowth, low proliferation rate, poor viability, and sparse cell characterization. Here, we investigated whether the recycling of fresh explants after a first conventional culture could improve physiological stability and sustainability of the culture. The recycled explants were able to give a supplementary cell culture showing faster outgrowth, cleaner cell layers and higher net cell production. The cells exhibited a highly stabilized profile for marker gene expression including a low cytokeratin 49 (epithelial marker) and a high collagen 1a1 (mesenchymal marker) expression. Added to the cell spindle-shaped morphology, motility behavior, and actin organization, this suggests that the cells bore stable mesenchymal characteristics. This contrast with the time-evolving expression pattern observed in the control fresh explants during the first 2 weeks of culture: a sharp decrease in cytokeratin 49 expression was concomitant with a gradual increase in col1a1. We surmise that such loss of epithelial features for the benefit of mesenchymal ones was triggered by an epithelial to mesenchymal transition (EMT) process or by way of a progressive population replacement process. Overall, our findings provide a comprehensive characterization of this new primary culture model bearing mesenchymal features and whose stability over culture time makes those cells good candidates for cell reprogramming prior to nuclear transfer, in a context of fish genome preservation. - Highlights: • Recycled fin explants outgrow cells bearing stable mesenchymal traits. • Cell production and quality is enhanced in the recycled explant culture system. • Fresh fin primary culture is highly variable and loose epithelial traits over time.

The FLUFF code for calculating finned surface heat transfer -description and user's guide

International Nuclear Information System (INIS)

Fry, C.J.

1985-08-01

FLUFF is a computer code for calculating heat transfer from finned surfaces by convection and radiation. It can also represent heat transfer by radiation to a partially emitting and absorbing medium within the fin cavity. The FLUFF code is useful not only for studying the behaviour of finned surfaces but also for deriving heat fluxes which can be applied as boundary conditions to other heat transfer codes. In this way models of bodies with finned surfaces may be greatly simplified since the fins need not be explicitly represented. (author)

Evaluation of integrally finned cladding for LMFBR fuel pins

International Nuclear Information System (INIS)

Cantley, D.A.; Sutherland, W.H.

1975-01-01

An integral fin design effectively reduces the coolant temperature gradients within an LMFBR subassembly by redistributing coolant flow so as to reduce the maximum cladding temperature and increase the duct wall temperature. The reduced cladding temperatures are offset by strain concentrations resulting from the fin geometry, so there is little net effect on predicted fuel pin performance. The increased duct wall temperatures, however, significantly reduce the duct design lifetime so that the final conclusion is that the integral fin design is inferior to the standard wire wrap design. This result, however, is dependent upon the material correlations used. Advanced alloys with improved irradiation properties could alter this conclusion

Experimental study of flow friction characteristics of integral pin-fin tubes

International Nuclear Information System (INIS)

Ding Ming; Yan Changqi; Sun Licheng

2007-01-01

Friction characteristics of integral pin-fin tubes, through which lubricating-oil flowed vertically, were studied experimentally. Effects of the pitch, the height of fins and the machining direction on friction coefficient were analyzed. The experimental results showed that the friction coefficient of the integral pin-fro tube was obviously lager than that of smooth tube. Compared with other influential factors, the effect of the height of fins was dominant. Because the three-dimensional pin fin could disturb and destroy the boundary layer, when the Reynolds Number reached 200-300, the friction coefficient curve began to bend, that was, a turning point was appeared in the friction coefficient curve. (authors)

Comprehensive study of flow and heat transfer at the surface of circular cooling fin

Science.gov (United States)

Mityakov, V. Yu; Grekov, M. A.; Gusakov, A. A.; Sapozhnikov, S. Z.; Seroshtanov, V. V.; Bashkatov, A. V.; Dymkin, A. N.; Pavlov, A. V.; Milto, O. A.; Kalmykov, K. S.

2017-11-01

For the first time is proposed to combine heat flux measurements with thermal imaging and PIV (particle image velocimetry) for a comprehensive study of flow and heat transfer at the surface of the circular cooling fin. The investigated hollow fin is heated from within with saturated water steam; meanwhile the isothermal external surface simulates one of the perfect fin. Flow and heat transfer at the surface of the solid fin of the same size and shape, made of titanium alloy is investigated in the same regimes. Gradient Heat Flux Sensors (GHFS) were installed at different places of the fin surface. Velocity field around a cylinder, temperature field at the surface of the fin and heat flux for each rated time were obtained. Comprehensive method including heat flux measurement, PIV and thermal imaging allow to study flow and heat transfer at the surface of the fin in real time regime. The possibility to study flow and heat transfer for non-isothermal fins is shown; it is allow to improve traditional calculation of the cooling fins.

Antioxidant and Antiproliferative Activities of Heated Sterilized Pepsin Hydrolysate Derived from Half-Fin Anchovy (Setipinna taty

Directory of Open Access Journals (Sweden)

Dongfeng Wang

2011-06-01

Full Text Available In this paper we studied the antioxidant and antiproliferative activities of the heated pepsin hydrolysate from a marine fish half-fin anchovy (HAHp-H. Furthermore, we compared the chemical profiles including the amino acid composition, the browning intensity, the IR and UV-visible spectra, and the molecular weight distribution between the half-fin anchovy pepsin hydrolysate (HAHp and HAHp-H. Results showed that heat sterilization on HAHp improved the 1,1-diphenyl-2-picryl-hydrazil (DPPH radical-scavenging activity and reducing power. In addition, the antiproliferative activities were all increased for HAHp-H on DU-145 human prostate cancer cell line, 1299 human lung cancer cell line and 109 human esophagus cancer cell line. The contents of free amino acid and reducing sugar of HAHp-H were decreased (P < 0.05. However, hydrophobic amino acid residues and the browning intensity of HAHp-H were increased. FT-IR spectroscopy indicated that amide I and amide III bands of HAHp-H were slightly modified, whereas band intensity of amide II was reduced dramatically. Thermal sterilization resulted in the increased fractions of HAHp-H with molecular weight of 3000–5000 Da and below 500 Da. The enhanced antioxidant and antiproliferative activities of HAHp-H might be attributed to the Maillard reaction.

Propulsive forces of mudskipper fins and salamander limbs during terrestrial locomotion: implications for the invasion of land.

Science.gov (United States)

Kawano, Sandy M; Blob, Richard W

2013-08-01

The invasion of land was a pivotal event in vertebrate evolution that was associated with major appendicular modifications. Although fossils indicate that the evolution of fundamentally limb-like appendages likely occurred in aquatic environments, the functional consequences of using early digited limbs, rather than fins, for terrestrial propulsion have had little empirical investigation. Paleontological and experimental analyses both have led to the proposal of an early origin of "hind limb-driven" locomotion among tetrapods or their ancestors. However, the retention of a pectoral appendage that had already developed terrestrial adaptations has been proposed for some taxa, and few data are available from extant functional models that can provide a foundation for evaluating the relative contributions of pectoral and pelvic appendages to terrestrial support among early stem tetrapods. To examine these aspects of vertebrate locomotor evolution during the invasion of land, we measured three-dimensional ground reaction forces (GRFs) produced by isolated pectoral fins of mudskipper fishes (Periophthalmus barbarus) during terrestrial crutching, and compared these to isolated walking footfalls by the forelimbs and hind limbs of tiger salamanders (Ambystoma tigrinum), a species with subequally-sized limbs that facilitate comparisons to early tetrapods. Pectoral appendages of salamanders and mudskippers exhibited numerous differences in GRFs. Compared with salamander forelimbs, isolated fins of mudskippers bear lower vertical magnitudes of GRFs (as a proportion of body weight), and had GRFs that were oriented more medially. Comparing the salamanders' forelimbs and hind limbs, although the peak net GRF occurs later in stance for the forelimb, both limbs experience nearly identical mediolateral and vertical components of GRF, suggesting comparable contributions to support. Thus, forelimbs could also have played a significant locomotor role among basal tetrapods that had limbs

Performance investigation of an innovative offset strip fin arrays in compact heat exchangers

International Nuclear Information System (INIS)

Peng, Hao; Ling, Xiang; Li, Juan

2014-01-01

Highlights: • The effect of fin pitch, length and bending distance on thermal performance were presented. • The corresponding Re C values at the j and f slope changes are in the range of 2000–2100. • The numerical results showed a good agreement with the experimental data. • Local high Nu values near the channel inlet, decreasing through the flow directions. - Abstract: Experimental and numerical studies on the flow and heat transfer characteristics for an innovative offset strip fins compact heat exchangers were performed. First, five fin schemes were investigated with various air flow velocities and a constant inlet steam pressure by experiments. The Reynolds number ranged from 500 to 5000 at the air side. The experimental results indicated that the fin pitch (P f ), fin length (L f ) and fin bending distance (C f ) have a significant influence on thermal performance of fins. The Colburn factor j, friction factor f and ‘point of transition’ were calculated from the experimental data. Then, the thermal–hydraulic performances of the novel offset strip fins were analyzed numerically. The simulation results obtained are in agreement with experimental data. Based on these simulations, the maximum values for local Nu number are at the channel inlet which is due to the thermal entrance effect. The longitudinal vortexes near the fin region will increase velocity gradient and reduce the thickness of boundary layer to improve heat transfer. The main conclusion draws from this work will be helpful for future development and design of a high-efficiency heat exchangers involving offset strip fin structures

Thermoelectric generator with hinged assembly for fins

International Nuclear Information System (INIS)

Purdy, D.L.; Shapiro, Z.M.; Hursen, T.F.; Maurer, G.W.

1976-01-01

A cylindrical casing has a central shielded capsule of radioisotope fuel. A plurality of thermonuclear modules are axially arranged with their hot junctions resiliently pressed toward the shield and with their cold junctions adjacent a transition member having fins radiating heat to the environment. For each module, the assembly of transition member and fins is hinged to the casing for swinging to permit access to and removal of such module. A ceramic plate having gold layers on opposite faces prevents diffusion bonding of the hot junction to the shield

Heat transfer enhancement of phase change materials by fins under simultaneous charging and discharging

International Nuclear Information System (INIS)

Joybari, Mahmood Mastani; Haghighat, Fariborz; Seddegh, Saeid; Al-Abidi, Abduljalil A.

2017-01-01

Highlights: • CFD simulation of a finned triplex tube heat exchanger with PCM under simultaneous charging and discharging. • Developed fin configurations for SCD, compatible with natural convection. • More fins enhanced the heat transfer as long as natural convection was not suppressed. • Longer fins enhanced the heat transfer as long as natural convection was not suppressed. • The effect of fin thickness was negligible, similar to non-SCD conditions. - Abstract: Due to the inherent intermittency of renewable energy sources such as solar, latent heat thermal energy storage in phase change materials (PCMs) has received considerable attention. Among several techniques to enhance PCMs’ thermal conductivity, the majority of studies have focused on fin integration due to its simplicity, ease of manufacturing, and low cost. In this study, utilization of extended surfaces (by longitudinal fins) was investigated by development of a numerical model to study the performance of a triplex tube heat exchanger (TTHX) equipped with a PCM under simultaneous charging and discharging (SCD). Governing equations were developed and numerically solved using ANSYS Fluent v16.2. Three conventional fin geometries and six developed fin configurations were compared based on the temperature, liquid fraction, and natural convection behavior under both SCD and non-SCD conditions. The intensity of natural convection was investigated for different fins for the inside heating/outside cooling scenario based on the solid–liquid interface evolution over time. The results indicated that since the buoyancy forces induce upward melted PCM motion, the inner hot tube requires fins on its lower half, while the outer cold one should be extended from its upper half. It was concluded that the case with 3 hot tube fins and 1 cold tube fin is most compatible with natural convection and provides the best performance under SCD conditions.

Data on volatile compounds in fermented materials used for salmon fish sauce production.

Science.gov (United States)

Nakano, Mitsutoshi; Sagane, Yoshimasa; Koizumi, Ryosuke; Nakazawa, Yozo; Yamazaki, Masao; Watanabe, Toshihiro; Takano, Katsumi; Sato, Hiroaki

2018-02-01

This article describes the analysis of volatile compounds in fermented materials used for salmon fish sauce production via gas chromatography/mass spectrometry (GC/MS). Ten types of fish sauces were produced from raw salmon materials, including various proportions of flesh, viscera, inedible portion (heads, fins, and backbones), and soft roe, by mixing them with salt and allowing them to ferment for up to three months. The volatile compounds were captured by a solid-phase microextraction method and then applied to GC/MS for separation and identification of the compounds in the fish sauce products. The number of volatile compounds identified in the starting materials varied from 15 to 29 depending on the ingredients. The number of compounds in the final fish sauce products was reduced by 3.4-94.7% of that in the original material. The retention times and names of the identified compounds, as well as their relative peak areas, are provided in a Microsoft Excel Worksheet.

Combined natural convection heat and mass transfer from vertical fin arrays

International Nuclear Information System (INIS)

Giri, A.; Narasimham, G.S.V.L.; Krishna Murthy, M.V.

2003-01-01

Natural convection transport processes play an important role in many applications like ice-storage air-conditioning. A mathematical formulation of natural convection heat and mass transfer over a shrouded vertical fin array is developed. The base plate is maintained at a temperature below the dew point of the surrounding moist air. Hence there occurs condensation of moisture on the base plate, while the fins may be partially or fully wet. A numerical study is performed by varying the parameters of the problem. The local and average Nusselt numbers decrease in streamwise direction and tend to approach fully developed values for sufficiently large values of the fin length. The results show that beyond a certain streamwise distance, further fin length does not improve the sensible and latent heat transfer performance, and that if dry fin analysis is used under moisture condensation conditions, the overall heat transfer will be underestimated by about 50% even at low buoyancy ratios

Optimization of convective-radiative fins by using differential quadrature element method

International Nuclear Information System (INIS)

Malekzadeh, P.; Rahideh, H.; Karami, G.

2006-01-01

A first endeavor to exploit the differential quadrature element method (DQEM) as a simple, accurate and computationally efficient numerical tool for the shape optimization of convective-radiating extended surfaces or fins is made. The formulations are general so that the spatial and spatial-temperature dependent geometrical and thermal parameters can easily be implemented. The thermal conductivity of the fin is assumed to vary as a linear function of the temperature. The effects of a convective-radiative condition at the fin tip and effective convective condition at the fin base are considered. The optimization of fins with uniform and step cross-sections is investigated. The accuracy of the method is demonstrated by comparing its results with those generated by Adomian's decomposition technique, Taylor transformation technique and finite difference method. It is shown that, using few grid points, highly accurate results are obtained. Less computational effort of the method with respect to the finite difference method is shown

Numerical simulation of a plate-fin heat exchanger with offset fins using porous media approach

Science.gov (United States)

Juan, Du; Hai-Tao, Zhao

2018-03-01

In this paper, the study was focused on a double flow plate-fin heat exchanger (PFHE) whose heat transfer element was offset staggered fin. Numerical simulations have been carried out to investigate the thermodynamic characteristics of a full-size PFHE via the porous media approach. Based on the numerical model, the effects of the dynamic viscosity and the locations of the inlet and outlet tubes on flow distribution and pressure drop of the PFHE were studied. The results showed that flow distribution of the PFHE was improved by increasing the dynamic viscosity. Therefore, the relationship between flow distribution and pressure drop was analyzed under various inlet velocity, and a correlation among flow distribution, pressure drop, and Reynolds number was derived. Finally, the middle-based strategy was proposed and numerically verified to improve flow distribution of the PFHE.

Numerical Modeling of Transient Heat Transfer in Longitudinal Fin

Directory of Open Access Journals (Sweden)

Farshad Panahizadeh

2017-11-01

Full Text Available The main objective of the present numerical study is to investigate the transient heat transfer in one kind of all-purpose longitudinal fin with the triangular profile. The lateral surface of the concerned fin and the tip of it are subjected to general situations included heat flux at the base and insulation on the tip. For this study developed a one dimensional in house code written by Fortran 90 programming language by using finite difference method with an implicit scheme in unsteady state condition. Generally, the result of this study in time variation state after 700 seconds is steady. The results also show the fin efficiency by increasing the time of study decreases due to a reduction in the total heat transfer which is happened in the fin. The grid independence study shows that for the number of nodes greater than 20 the result will not be changed and same as before. Finally, the result of Fortran code verified by commercial CFD code which relies on finite difference method and it was shown have a consistent agreement

Effect of storage media and time on fin explants culture in the ...

African Journals Online (AJOL)

The effect of storage media and time was investigated on fin explants culture in the goldfish (Carassius auratus). Fin explants under sterile conditions were able to produce cells at different storage media and time. On the outgrowth of cells, fin explants stored for seven days before culturing showed significantly higher growth ...

A thermal study of pipes with outer transverse fins

Directory of Open Access Journals (Sweden)

S. Gil

2016-10-01

Full Text Available This paper provides results of thermal investigations on pipes with outer transverse fins produced by placing a strip, being a form of helical spring which functions as a radiator, on the basis pipe. The investigations were carried out at the facility that enables measurements with respect to both natural and forced convection. Performance of the investigated pipes was assessed in relation to a non-finned pipe and a pipe welded with the use of Metal Active Gas (MAG technology. The experiments have shown that the finned pipe welding technology does not markedly affect their thermal efficiency, which has been confirmed by performed model calculations, while the welding technology has a crucial impact on their operating performance.

High performance flexible CMOS SOI FinFETs

KAUST Repository

Fahad, Hossain M.

2014-06-01

We demonstrate the first ever CMOS compatible soft etch back based high performance flexible CMOS SOI FinFETs. The move from planar to non-planar FinFETs has enabled continued scaling down to the 14 nm technology node. This has been possible due to the reduction in off-state leakage and reduced short channel effects on account of the superior electrostatic charge control of multiple gates. At the same time, flexible electronics is an exciting expansion opportunity for next generation electronics. However, a fully integrated low-cost system will need to maintain ultra-large-scale-integration density, high performance and reliability - same as today\\'s traditional electronics. Up until recently, this field has been mainly dominated by very weak performance organic electronics enabled by low temperature processes, conducive to low melting point plastics. Now however, we show the world\\'s highest performing flexible version of 3D FinFET CMOS using a state-of-the-art CMOS compatible fabrication technique for high performance ultra-mobile consumer applications with stylish design. © 2014 IEEE.

Characteristics of a micro-fin evaporator: Theoretical analysis and experimental verification

OpenAIRE

Zheng Hui-Fan; Fan Xiao-Wei; Wang Fang; Liang Yao-Hua

2013-01-01

A theoretical analysis and experimental verification on the characteristics of a micro-fin evaporator using R290 and R717 as refrigerants were carried out. The heat capacity and heat transfer coefficient of the micro-fin evaporator were investigated under different water mass flow rate, different refrigerant mass flow rate, and different inner tube diameter of micro-fin evaporator. The simulation results of the heat transfer coefficient are fairly in good a...

The potency of curing fish waste pellet for growth and protein level of African sharptooth catfish (Clarias gariepinus)

Science.gov (United States)

Nurhayati, Awik Puji Dyah; Febiyani, Asti R.

2017-06-01

Fish curing in Kenjeran, Surabaya produces waste such as fish offal, tail and fins which still has some nutrients, especially protein content, so it can be used as fish feed. Fish feed is an important factor in fish growth. Farmers usually use commercial fish pellets, but the price is relatively more expensive. Curing fish waste which is less expensive can be used as materials for pellets. The purpose of this study is to utilize curing fish waste as a material fish pellets for growth African catfish. Experimental design of this research is Completely Randomized Design (CRD) with 1 factorial. The pellets varieties were of K.0, K.1, K.2, K.3, and K.4. The pellets were given to the fish for 30 days. Data of growth rate, survival rate and FCR and protein level data of the pellet and the fish flesh were analyzed by one-way ANOVA statistical method. The analysis shows that the K.4 treatment has a best result of relatively growth of length (72.64%)and relatively growth of weight (488,97%). Protein level of fish flesh is 20.97%. The survival rate of 98%, FCR most efficient pellets exist is K.4.

Optimization design of LED heat dissipation structure based on strip fins

Science.gov (United States)

Xue, Lingyun; Wan, Wenbin; Chen, Qingguang; Rao, Huanle; Xu, Ping

2018-03-01

To solve the heat dissipation problem of LED, a radiator structure based on strip fins is designed and the method to optimize the structure parameters of strip fins is proposed in this paper. The combination of RBF neural networks and particle swarm optimization (PSO) algorithm is used for modeling and optimization respectively. During the experiment, the 150 datasets of LED junction temperature when structure parameters of number of strip fins, length, width and height of the fins have different values are obtained by ANSYS software. Then RBF neural network is applied to build the non-linear regression model and the parameters optimization of structure based on particle swarm optimization algorithm is performed with this model. The experimental results show that the lowest LED junction temperature reaches 43.88 degrees when the number of hidden layer nodes in RBF neural network is 10, the two learning factors in particle swarm optimization algorithm are 0.5, 0.5 respectively, the inertia factor is 1 and the maximum number of iterations is 100, and now the number of fins is 64, the distribution structure is 8*8, and the length, width and height of fins are 4.3mm, 4.48mm and 55.3mm respectively. To compare the modeling and optimization results, LED junction temperature at the optimized structure parameters was simulated and the result is 43.592°C which approximately equals to the optimal result. Compared with the ordinary plate-fin-type radiator structure whose temperature is 56.38°C, the structure greatly enhances heat dissipation performance of the structure.

A novel louvered fin design to enhance thermal and drainage performances during periodic frosting/defrosting conditions

International Nuclear Information System (INIS)

Kim, Min-Hwan; Kim, Hisuk; Kim, Dong Rip; Lee, Kwan-Soo

2016-01-01

Highlights: • Thermal and drainage performances of a novel design louvered fin were investigated. • The thermal performance of the asymmetric fin was improved in the re-frosting cycle. • The asymmetric louvered fin exhibited better drainage on the leading edge of fins. • Lower surface tension between fin surface and water droplet improved the drainage. - Abstract: The retention water on fin surface can significantly degrade the thermal performance of heat exchangers under periodic frosting/defrosting conditions, which also leads to a decrease in the energy efficiency of air-source heat pumps. A novel louvered fin design was suggested to improve the drainage and the thermal performance of heat exchanger. The novel louvered fin had an asymmetric louver arrangement by flattening two louvers on the leading edge. The retention water formed on fin surface markedly decreased the heat transfer rate of the conventional symmetric louvered fins in re-frosting cycles. On the other hand, the asymmetric louvered fins improved the drainage performance of the retention water, which enhanced the heat transfer rate. To identify the reason of the difference in drainage performance between two fin geometries, additional experiments were carried out with enlargement models. The improvement in drainage performance of the asymmetric fin design originated from the lowered surface tension between the fin surface and water droplet.

Enhancement of heat transfer from a continuously moving porous fin exposed in convective–radiative environment

International Nuclear Information System (INIS)

Bhanja, Dipankar; Kundu, Balaram; Aziz, Abdul

2014-01-01

Highlights: • Analytical model for thermal analysis of moving porous fins. • Heat transfer from the fin surface due to convection and radiation. • For practical design aspects, optimization analysis was carried out. • Comparative study was made between the solid and porous moving fins. • Porous moving fin has more heat transfer ability than the stationary fin. - Abstract: In the present article, an exercise has been devoted to establish an analytical model for the determination of temperature distribution, fin efficiency and optimum design parameters of a porous moving fin which is losing heat by simultaneous convection and radiation to its surroundings. For the adaptation of this consideration, the governing equation becomes highly nonlinear. An analytical technique called Adomian decomposition method (ADM) is proposed for the solution methodology. The accuracy of the analytic solution is validated by using a numeric scheme called finite difference method. The results indicate that the numerical data and analytical approach are in agreement with each other. As the present study is an analytic, it is extended to the analysis for determination of optimum dimensions of said fin by satisfying either the maximization of rate of heat transfer for a given fin volume or by the minimization of fin volume for a desired heat transfer rate. The study is further extended to the porous fin in stationary condition and it is found that porous fin in moving condition transfers more heat than stationary condition. Investigation has also been made on solid moving fin to compare the outcomes of these parameters

Whole-body calcium flux rates in cichlid teleost fish Oreochromis mossambicus adapted to freshwater

International Nuclear Information System (INIS)

Flik, G.; Fenwick, J.C.; Kolar, Z.; Mayer-Gostan, N.; Wendelaar Bonga, S.E.

1985-01-01

Radiotracer techniques were used to measure influx and efflux rates of Ca 2+ in freshwater-adapted Oreochromis mossambicus. The influx rate of Ca 2+ is related to body weight (W) as Fin = 50W0.805 nmol Ca 2+ /h. For a 20-g fish the calculated influx rate was 558 nmol Ca 2+ /h, and this was attributed largely to extraintestinal uptake since the drinking rate was estimated to be only 28 microliter water/h, which corresponds to an intake of 22.4 nmol Ca 2+ /h. The Ca 2+ efflux rate was calculated using the initial rate of appearance of radiotracer in the ambient water and the specific activity of plasma Ca 2+ . Tracer efflux rates were constant over 6-8 h, which indicated that there was no substantial loss of tracer in either the urine or the feces because this would have resulted in random bursts of tracer loss. Efflux rates then primarily represent integumentary and presumably branchial efflux rates. The efflux rate of Ca 2+ is related to body weight as Fout = 30W0.563 nmol Ca 2+ /h, which means an efflux rate of 162 nmol Ca 2+ /h for a 20-g fish. The net whole-body Ca 2+ influx, calculated as Fnet = Fin - Fout, was 396 nmol/h for a 20-g fish, which proves that the ambient water is an important source of Ca 2+

First records of scale deformities in seven freshwater fish species (Actinopterygii: Percidae and Cyprinidae) collected from three ponds in the Czech Republic

Czech Academy of Sciences Publication Activity Database

Rutkayová, J.; Jawad, L.; Nebesářová, Jana; Beneš, K.; Petrášková, E.; Näslund, J.

2016-01-01

Roč. 46, č. 3 (2016), s. 225-238 ISSN 0137-1592 Institutional support: RVO:60077344 Keywords : fish * scale abnormality * adverse environment * Cyprinidae * Percidae Subject RIV: EG - Zoology Impact factor: 0.670, year: 2016

Laser Welding Of Finned Tubes Made Of Austenitic Steels

Directory of Open Access Journals (Sweden)

Stolecki M.

2015-09-01

Full Text Available This paper describes the technology of welding of finned tubes made of the X5CrNi1810 (1.4301 austenitic steel, developed at Energoinstal SA, allowing one to get high quality joints that meet the requirements of the classification societies (PN-EN 15614, and at the same time to significantly reduce the manufacturing costs. The authors described an automatic technological line equipped with a Trumph disc laser and a tube production technological process. To assess the quality of the joints, one performed metallographic examinations, hardness measurements and a technological attempt to rupture the fin. Analysis of the results proved that the laser-welded finned tubes were performed correctly and that the welded joints had shown no imperfections.

Simulation study of a 3-D device integrating FinFET and UTBFET

KAUST Repository

Fahad, Hossain M.

2015-01-01

By integrating 3-D nonplanar fins and 2-D ultrathin bodies, wavy FinFETs merge two formerly competing technologies on a silicon-on-insulator platform to deliver enhanced transistor performance compared with conventional trigate FinFETs with unprecedented levels of chip-area efficiency. This makes it suitable for ultralarge-scale integration high-performance logic at and beyond the 10-nm technology node.

Investigation on flow and heat transfer characteristics in rectangular channel with drop-shaped pin fins

Directory of Open Access Journals (Sweden)

Fengming Wang

2012-12-01

Full Text Available The flow and heat transfer characteristics inside a rectangular channel embedded with pin fins were numerically and experimentally investigated. Several differently shaped pin fins (i.e., circular, elliptical, and drop-shaped with the same cross-sectional areas were compared in a staggered arrangement. The Reynolds number based on the obstructed section hydraulic diameter (defined as the ratio of the total wetted surface area to the open duct volume available for flow was varied from 4800 to 8200. The more streamlined drop-shaped pin fins were better at delaying or suppressing separation of the flow passing through them, which decreased the aerodynamic penalty compared to circular pin fins. The heat transfer enhancement of the drop-shaped pin fins was less than that of the circular pin fins. In terms of specific performance parameters, drop-shaped pin fins are a promising alternative configuration to circular pin fins.

Multi-Mode Electric Actuator Dynamic Modelling for Missile Fin Control

Directory of Open Access Journals (Sweden)

Bhimashankar Gurav

2017-06-01

Full Text Available Linear first/second order fin direct current (DC actuator model approximations for missile applications are currently limited to angular position and angular velocity state variables. Furthermore, existing literature with detailed DC motor models is decoupled from the application of interest: tail controller missile lateral acceleration (LATAX performance. This paper aims to integrate a generic DC fin actuator model with dual-mode feedforward and feedback control for tail-controlled missiles in conjunction with the autopilot system design. Moreover, the characteristics of the actuator torque information in relation to the aerodynamic fin loading for given missile trim velocities are also provided. The novelty of this paper is the integration of the missile LATAX autopilot states and actuator states including the motor torque, position and angular velocity. The advantage of such an approach is the parametric analysis and suitability of the fin actuator in relation to the missile lateral acceleration dynamic behaviour.

FINCRUSH : a computer program for impact analysis of radioactive material transport cask with fins

International Nuclear Information System (INIS)

Ikushima, Takeshi

1997-05-01

In drop impact analyses for radioactive material transport cask with cooling fins, relationship between fin plastic deformation and fin energy absorption is used. This relationship was obtained by ORNL experiments and MONSER Co. in Canada. Based on ORNL experiments, a computer program FINCRUSH has been developed for rapid safety analysis of cask drop impact to obtain the maximum impact acceleration and the maximum fin deformation. Main features of FINCRUSH are as follows: (1) annulus fins on a cylindrical shell and plate fins on a disk can be treated, (2) it is capable of graphical representations for calculation results and fin absorption energy data and (3) not only main frame computer but also work stations (OS UNIX) and personal computer (OS Windows) are available for use of the FINCRUSH. In the paper, brief illustration of calculation method of FINCRUSH is presented. The second section presents comparisons between FINCRUSH and experimental results. The third section provides a use's guide for FINCRUSH. (author)

FINCRUSH : a computer program for impact analysis of radioactive material transport cask with fins

Energy Technology Data Exchange (ETDEWEB)

Ikushima, Takeshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1997-05-01

In drop impact analyses for radioactive material transport cask with cooling fins, relationship between fin plastic deformation and fin energy absorption is used. This relationship was obtained by ORNL experiments and MONSER Co. in Canada. Based on ORNL experiments, a computer program FINCRUSH has been developed for rapid safety analysis of cask drop impact to obtain the maximum impact acceleration and the maximum fin deformation. Main features of FINCRUSH are as follows: (1) annulus fins on a cylindrical shell and plate fins on a disk can be treated, (2) it is capable of graphical representations for calculation results and fin absorption energy data and (3) not only main frame computer but also work stations (OS UNIX) and personal computer (OS Windows) are available for use of the FINCRUSH. In the paper, brief illustration of calculation method of FINCRUSH is presented. The second section presents comparisons between FINCRUSH and experimental results. The third section provides a use`s guide for FINCRUSH. (author)

Line-edge roughness induced single event transient variation in SOI FinFETs

International Nuclear Information System (INIS)

Wu Weikang; An Xia; Jiang Xiaobo; Chen Yehua; Liu Jingjing; Zhang Xing; Huang Ru

2015-01-01

The impact of process induced variation on the response of SOI FinFET to heavy ion irradiation is studied through 3-D TCAD simulation for the first time. When FinFET biased at OFF state configuration (V gs = 0, V ds = V dd ) is struck by a heavy ion, the drain collects ionizing charges under the electric field and a current pulse (single event transient, SET) is consequently formed. The results reveal that with the presence of line-edge roughness (LER), which is one of the major variation sources in nano-scale FinFETs, the device-to-device variation in terms of SET is observed. In this study, three types of LER are considered: type A has symmetric fin edges, type B has irrelevant fin edges and type C has parallel fin edges. The results show that type A devices have the largest SET variation while type C devices have the smallest variation. Further, the impact of the two main LER parameters, correlation length and root mean square amplitude, on SET variation is discussed as well. The results indicate that variation may be a concern in radiation effects with the down scaling of feature size. (paper)

Determination of optimum fin profile for a zero-G capillary drained condenser

Science.gov (United States)