Science.gov

Sample records for medios sin fin

  1. The dependency of different stress-level SiN capping films and the optimization of D-SMT process for the device performance booster in Ge n-FinFETs

    SciTech Connect

    Liao, M.-H. Chen, P.-G.

    2015-08-17

    The capping stressed SiN film is one of the most important process steps for the dislocation stress memorization technique (D-SMT), which has been used widely in the current industry, for the electron mobility booster in the n-type transistor beyond the 32/28 nm technology node. In this work, we found that the different stress-level SiN capping films influence the crystal re-growth velocities along different directions including [100] and [110] directions in Ge a lot. It can be further used to optimize the dislocation angle in the transistor during the D-SMT process and then results in the largest channel stress distribution to boost the device performance in the Ge n-FinFETs. Based on the theoretical calculation and experimental demonstration, it shows that the Ge three dimensional (3D) n-FinFETs device performance is improved ∼55% with the usage of +3 GPa tensile stressed SiN capping film. The channel stress and dislocation angle is ∼2.5 GPa and 30°, measured by the atomic force microscope-Raman technique and transmission electron microscopy, respectively.

  2. Windsurfer Fin

    NASA Technical Reports Server (NTRS)

    1994-01-01

    A NASA report detailing a wind tunnel investigation of a variable camber and twist could effectively reduce drag, thus improving performance. The resulting VooDoo fin is made of composite materials, has a rigid internal spar and a flexible polymer exterior coating. It is computer-designed and exceptionally durable.

  3. Cúmulos abiertos y su medio interestelar

    NASA Astrophysics Data System (ADS)

    Rizzo, J. R.; Arnal, E. M.; Morras, R.; Cappa, C.

    Se analiza la distribución del hidrógeno neutro en la vecindad de cuatro cúmulos abiertos ubicados en el cuarto cuadrante galáctico, con el fin de investigar su posible interacción con el medio interestelar circundante. El estudio se lleva a cabo en base a observaciones de la línea de 21 cm del HI obtenidos con la antena de 30 m del IAR.

  4. Mechanosensation in an adipose fin

    PubMed Central

    2016-01-01

    Adipose fins are found on approximately 20% of ray-finned fish species. The apparently rudimentary anatomy of adipose fins inspired a longstanding hypothesis that these fins are vestigial and lack function. However, adipose fins have evolved repeatedly within Teleostei, suggesting adaptive function. Recently, adipose fins were proposed to function as mechanosensors, detecting fluid flow anterior to the caudal fin. Here we test the hypothesis that adipose fins are mechanosensitive in the catfish Corydoras aeneus. Neural activity, recorded from nerves that innervate the fin, was shown to encode information on both movement and position of the fin membrane, including the magnitude of fin membrane displacement. Thus, the adipose fin of C. aeneus is mechanosensitive and has the capacity to function as a ‘precaudal flow sensor’. These data force re-evaluation of adipose fin clipping, a common strategy for tagging fishes, and inform hypotheses of how function evolves in novel vertebrate appendages. PMID:26984621

  5. Medio Communication: A Conceptualization.

    ERIC Educational Resources Information Center

    Blake, Reed H.

    The classification of communication activity into interpersonal and mass communication is inadequate. A third category, "medio" communication, is also needed. Examples of this third type include point-to-point telecommunication (such as the telephone or mobile radio), surveillance telecommunication, and closed-circuit television. Medio…

  6. Managing asbestos: Ten costly sins

    SciTech Connect

    Denson, F.A.; Onderick, W.A.

    1993-01-01

    This article describes how to build an ongoing, continuous, and improved asbestos management program. Asbestos management is one of the toughest jobs facing a plant or environmental engineer today; even seasoned engineers can make mistakes. Much confusion exists about how best to manage this issue, especially in plant settings. Whether the company is small, medium, or large, asbestos has the power to steal from profits if not managed properly. To help POWER readers examine their current asbestos management programs, here are 10 common errors that could be stopped or avoided by practicing preventive techniques. The 10 costly sins presented are not mutually exclusive, and they certainly are not all-inclusive. They are offered as a way to stimulate ideas on how to build an ongoing, continuous, and improved asbestos management program. These include Sin 1: No written policy. Sin 2: Lack of corporate guidance. Sin 3: Not complying with regulations. Sin 4: Not worrying about other respirable fibers. Sin 5: Lawsuits--not culpable. Sin 6: No visible emissions, no problems. Sin 7: Managing asbestos manually.

  7. FinEx-Fin Experiment On HIFIRE-5

    NASA Astrophysics Data System (ADS)

    Bohrk, H.; Lohle, S.; Fuchs, U.; Elsaber, H.; Weihs, H.

    2011-05-01

    A set of four ceramic fins will fly as a passenger experiment onboard the american- australian hypersonic vehicle HIFiRE-5. The paper describes their lay-out and design. They consist of C/C-SiC and are mounted to the rocket by aluminum fin shoes. With a total of eight implanted thermocouples, the fins serve to determine three-dimensional heat flux to the CMC fins on the basis of a non-integer system identification approach. Both, the approach and the calibration procedure are described. It is, moreover, demonstrated that the fins are ready for flight.

  8. Sailboard Fin Design

    NASA Technical Reports Server (NTRS)

    1992-01-01

    In high performance boardsailing, demands on the vertical fin or "skeg" often produce "spinout" - when the skeg loses horizontal lift creating a force imbalance and causing the tail of the board to slide sideways. Richard Caldwell, RACE Technology, Inc. used NASA airfoil technology to solve this problem and formed a business based on his solution. After determining that the spinout resulted from air ventilating down the low pressure side of the underwater fin, he adapted the airfoil technology to the design of a short board skeg, which would overcome the problem and lower the drag, resulting in improved performance. He patented his RACE 145 foil section, formed his company and later returned to Langley for additional technical assistance. The company's newest product is a rigid sail that also incorporates NASA technology and has excellent performance. This company no longer exists - product is no longer in production.

  9. [Toxicity of puffer fish fins].

    PubMed

    Honda, Shunichi; Ichimaru, Shunichi; Arakawa, Osamu; Takatani, Tomohiro; Noguchi, Tamao; Ishizaki, Shoichiro; Nagashima, Yuji

    2007-10-01

    Puffer fish is prized as a Japanese traditional food and its fin is also used in the cuisine. However, whether the fin is edible or not is determined for convenience from the toxicity of skin, since little information is available about the toxicity of puffer fish fins. In the present study, we examined the toxicity of fins and skin of three toxic species, Takifugu vermicularis, T. snyderi, and T. porphyreus. The toxicity of T. vermicularis fins (< 5-52.4 MU/g) was significantly lower than that of skin (<5-1200 MU/g). HPLC analysis showed that tetrodotoxin was a major toxic principle irrespective of the toxicity value in each tissue of T. vermicularis. In the case of T. snyderi and T. porphyreus, the toxicity of fins was at almost the same level as that of the skin. The toxicity (< 10-12 MU/g) of caudal fins of T. porphyreus was apparently increased to 16.5-22.0 MU/g by drying. However, the toxin amounts in the dried fins were slightly decreased as compared with those of the non-dried fins. These results demonstrate that puffer fish with toxic skin also have toxic fins.

  10. Fully-Implicit Navier-Stokes (FIN-S)

    NASA Technical Reports Server (NTRS)

    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.

  11. Blower Cooling of Finned Cylinders

    NASA Technical Reports Server (NTRS)

    Schey, Oscar W; Ellerbrock, Herman H , Jr

    1937-01-01

    Several electrically heated finned steel cylinders enclosed in jackets were cooled by air from a blower. The effect of the air conditions and fin dimensions on the average surface heat-transfer coefficient q and the power required to force the air around the cylinders were determined. Tests were conducted at air velocities between the fins from 10 to 130 miles per hour and at specific weights of the air varying from 0.046 to 0.074 pound per cubic foot. The fin dimensions of the cylinders covered a range in pitches from 0.057 to 0.25 inch average fin thicknesses from 0.035 to 0.04 inch, and fin widths from 0.67 to 1.22 inches.

  12. Underwater fin swimming in women with reference to fin selection.

    PubMed

    Pendergast, D R; Mollendorf, J; Logue, C; Samimy, S

    2003-01-01

    Underwater swimmers use fins, which provide thrust to overcome drag and propel the diver. The type of fin used has been shown to affect diver performance, however data are lacking for women. The oxygen consumption (VdotO2) of swimming as a function of speed, velocity as a function of kick frequency, maximal speed (v), maximal VdotO2 and the maximal thrust were determined for 8 female divers swimming at 1.25 m depth in a 60 m annular pool. VdotO2 increased as a function of v as; 0.52 + -0.485 V + 2.85 V2 (r2 = 0.996) and 0.12 + 1.52 V +1.275 V2 (r2 = 0.999) for high (5 fins) and low (3 fins) groupings, respectively. Splits, vents and flanges did not significantly affect VdotO2. Kick frequency increased linearly with v, with unique slopes for each fin. Maximal VdotO2 was not affect by fin type (1.46 +/- 0.05 l/min). Velocities that could be stained aerobically were 0.60 +/- 0.02 m/sec on average, with the most flexible fin higher (0.71 m/sec). Maximal v averaged 0.87 +/- 0.03 m/sec, with the most rigid fin lower (0.77 m/sec). Maximal thrust was not affected by fin and averaged 104 +/- 9 N. It can be concluded that female divers preferred the most flexible fins, which were also the most economical. This is most likely due to low leg power, which could also explain the absence of differences in maximal thrust and velocity.

  13. Parametric Fin-Body and Fin-Plate Database for a Series of 12 Missile Fins

    NASA Technical Reports Server (NTRS)

    Allen, Jerry M.

    2001-01-01

    A cooperative experimental investigation has been performed to obtain a systematic fin-body and fin-plate database for a series of 12 missile fins. These data are intended to complement and extend the information contained in the Triservice missile project and to provide a systematic set of experimental data from which fin-body interference factors can be derived. Data were obtained with the fins mounted on both an axisymmetric body and on a flat plate that was used to simulate fin-alone measurements. The experiments were conducted at Mach numbers from 0.60 to 3.95; fin deflection angles of 0 deg, 10 deg, and -10 deg; and angles of attack up to 30 deg on the body and up to 95 deg on the flat plate. The data were obtained from three-component balances attached to the fins and a six-component balance located in the axisymmetric body. The data obtained in this project are documented in tabular form in this report. In addition, selected data are presented in graphical form to illustrate the effects of the test variables. These variables are configuration angle of attack; Mach number; and fin parameters of deflection angle, planform size, taper ratio, and aspect ratio. A very limited comparison with the Triservice missile data is made to illustrate the consistency between the data from these two projects.

  14. The ethics of sin taxes.

    PubMed

    Green, Rebecca

    2011-01-01

    ABSTRACT The current global economic crisis is forcing governments to consider a variety of methods to generate funds for infrastructure. In the United States, smoking-related illness and an obesity epidemic are forcing public health institutions to consider a variety of methods to influence health behaviors of entire target groups. In this paper, the author uses a public health nursing model, the Public Health Code of Ethics (Public Health Leadership Society, 2002), the American Nurses' Association (ANA) Code of Ethics (2001), and other relevant ethical theory to weigh and balance the arguments for and against the use of sin taxes. A position advocating the limited use of sin taxes is supported as a reasonable stance for the public health professional.

  15. Fin-line horn antenna

    DOEpatents

    Reindel, John

    1990-01-01

    A fin line circuit card containing a fin line slot feeds a dipole antenna ich extends a quarterwave outside the waveguide and provides an energy beam focal point at or near the open end of the waveguide. The dipole antenna thus maintains a wide and nearly constant beamwidth, low VSWR and a circular symmetric radiation pattern for use in electronic warfare direction finding and surveillance applications.

  16. IN GRAMMAR'S FALL, WE SINNED ALL.

    ERIC Educational Resources Information Center

    TIBBETTS, A.M.

    THROUGH THEIR LOSS OF FAITH IN TRADITIONAL GRAMMAR, MEN HAVE "SINNED" AND CONTRIBUTED SLIGHTLY BUT IMPORTANTLY TO THE CREATION OF AN AMORAL AND RELATIVISTIC SOCIETY. PROMPTED BY THE SIN OF INTELLECTUAL PRIDE, SOME LINGUISTS SEEM TO ASSUME THAT GRAMMATICAL PROBLEMS CAN BE SOLVED BY RATIOCINATION ALONE. IGNORANCE OF THE PAST--ANOTHER SIN--AND…

  17. Bulk FinFETs with body spacers for improving fin height variation

    NASA Astrophysics Data System (ADS)

    Wei, Xing; Zhu, Huilong; Zhang, Yanbo; Zhao, Chao

    2016-08-01

    A novel FinFET structure with body spacers in sub fin (BSSF) is proposed to improve the fin height variation produced in the manufacturing processes. Device simulation results are presented to show the electrical variations improvement. The effective fin height (Heff) of FinFETs with BSSF is well controlled because it only depends on the silicon epi layer thickness (TSi). Taking advantage of the precisely controlled epitaxy process, Heff uniformity of FinFETs with BSSF is much better than conventional bulk FinFETs. Benefit from the smaller Heff variation, FinFETs with BSSF show much smaller electrical characteristics variation. For n-FinFETs, the Ion variation improves from 33.46% for conventional bulk FinFETs to 8.05% for FinFETs with BSSF. Additionally, manufacturing of FinFETs with BSSF is compatible with that of the state-of-the-art bulk FinFETs, promising for its applications in massive production.

  18. 50 CFR 600.1204 - Shark finning; possession at sea and landing of shark fins.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 10 2011-10-01 2011-10-01 false Shark finning; possession at sea and... PROVISIONS Shark Finning § 600.1204 Shark finning; possession at sea and landing of shark fins. (a)(1) No person aboard a U.S. fishing vessel shall engage in shark finning in waters seaward of the inner...

  19. 50 CFR 600.1204 - Shark finning; possession at sea and landing of shark fins.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Shark finning; possession at sea and... PROVISIONS Shark Finning § 600.1204 Shark finning; possession at sea and landing of shark fins. (a)(1) No person aboard a U.S. fishing vessel shall engage in shark finning in waters seaward of the inner...

  20. 50 CFR 600.1204 - Shark finning; possession at sea and landing of shark fins.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 12 2012-10-01 2012-10-01 false Shark finning; possession at sea and... PROVISIONS Shark Finning § 600.1204 Shark finning; possession at sea and landing of shark fins. (a)(1) No person aboard a U.S. fishing vessel shall engage in shark finning in waters seaward of the inner...

  1. 50 CFR 600.1204 - Shark finning; possession at sea and landing of shark fins.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Shark finning; possession at sea and... PROVISIONS Shark Finning § 600.1204 Shark finning; possession at sea and landing of shark fins. (a)(1) No person aboard a U.S. fishing vessel shall engage in shark finning in waters seaward of the inner...

  2. A Roll, Fin, and Fin Controller Prediction Computer Program.

    DTIC Science & Technology

    1980-06-01

    Reference 1, and specific details of this improve- ment will be published in a future report currently under preparation by Cox. *A complete listing of...effects. CONCLUDING RMARKS This report provides a user’s guide to FINCON, a roll, fin, fin con- troller prediction computer program. No attempt to...180. FLOATIMUOIINU) ROLL I# OA14PUINUI a OUCIIV,1 ROLL 19 IF ( ITEPATE .EQ.0) O T3 98’ ROLL 106 Ise NTIY 0 ROLL lot To 0.0 ROLL lit s0 NTRY - NTYRY I

  3. SIN3A and SIN3B differentially regulate breast cancer metastasis

    PubMed Central

    Lewis, Monica J.; Liu, Jianzhong; Libby, Emily Falk; Lee, Minnkyong; Crawford, Nigel P.S.; Hurst, Douglas R.

    2016-01-01

    SIN3 corepressor complexes play important roles in both normal development and breast cancer. Mammalian cells have two paralogs of SIN3 (SIN3A and SIN3B) that are encoded by distinct genes and have unique functions in many developmental processes. However, specific roles for SIN3A and SIN3B in breast cancer progression have not been characterized. We generated stable knockdown cells of SIN3 paralogs individually and in combination using three non-overlapping shRNA. Stable knockdown of SIN3B caused a significant decrease in transwell invasion through Matrigel and decreased the number of invasive colonies when grown in a 3D extracellular matrix. Conversely, stable knockdown of SIN3A significantly increased transwell invasion and increased the number of invasive colonies. These results were corroborated in vivo in which SIN3B knockdown significantly decreased and SIN3A knockdown increased experimental lung metastases. RNA sequencing was used to identify unique targets and biological pathways that were altered upon knockdown of SIN3A compared to SIN3B. Additionally, we analyzed microarray data sets to identify correlations of SIN3A and SIN3B expression with survival in patients with breast cancer. These data sets indicated that high mRNA expression of SIN3A as well as low mRNA expression of SIN3B correlates with longer relapse free survival specifically in patients with triple negative breast cancer which corresponds with our in vitro and in vivo data. These results demonstrate key functional differences between SIN3 paralogs in regulating the process of breast cancer metastasis and suggest metastasis suppressive roles of SIN3A and metastasis promoting roles of SIN3B. PMID:27780928

  4. 50 CFR 600.1204 - Shark finning; possession at sea and landing of shark fins.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... (including any cargo vessel that received shark fins from a fishing vessel at sea) shall land shark fins... and who lands shark fins harvested in waters seaward of the inner boundary of the U.S. EEZ shall land... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Shark finning; possession at sea...

  5. A biorobotic model of the sunfish pectoral fin for investigations of fin sensorimotor control.

    PubMed

    Phelan, Chris; Tangorra, James; Lauder, George; Hale, Melina

    2010-09-01

    A comprehensive understanding of the control of flexible fins is fundamental to engineering underwater vehicles that perform like fish, since it is the fins that produce forces which control the fish's motion. However, little is known about the fin's sensory system or about how fish use sensory information to modulate the fin and to control propulsive forces. As part of a research program that involves neuromechanical and behavioral studies of the sunfish pectoral fin, a biorobotic model of the pectoral fin and of the fin's sensorimotor system was developed and used to investigate relationships between sensory information, fin ray motions and propulsive forces. This robotic fin is able to generate the motions and forces of the biological fin during steady swimming and turn maneuvers, and is instrumented with a relatively small set of sensors that represent the biological lateral line and receptors hypothesized to exist intrinsic to the pectoral fin. Results support the idea that fin ray curvature, and the pressure in the flow along the wall that represents the fish body, capture time-varying characteristics of the magnitude and direction of the force created throughout a fin beat. However, none of the sensor modalities alone are sufficient to predict the propulsive force. Knowledge of the time-varying force vector with sufficient detail for the closed-loop control of fin ray motion will result from the integration of characteristics of many sensor modalities.

  6. Full regeneration of the tribasal Polypterus fin.

    PubMed

    Cuervo, Rodrigo; Hernández-Martínez, Rocío; Chimal-Monroy, Jesús; Merchant-Larios, Horacio; Covarrubias, Luis

    2012-03-06

    Full limb regeneration is a property that seems to be restricted to urodele amphibians. Here we found that Polypterus, the most basal living ray-finned fish, regenerates its pectoral lobed fins with a remarkable accuracy. Pectoral Polypterus fins are complex, formed by a well-organized endoskeleton to which the exoskeleton rays are connected. Regeneration initiates with the formation of a blastema similar to that observed in regenerating amphibian limbs. Retinoic acid induces dose-dependent phenotypes ranging from inhibition of regeneration to apparent anterior-posterior duplications. As in all developing tetrapod limbs and regenerating amphibian blastema, Sonic hedgehog is expressed in the posterior mesenchyme during fin regeneration. Hedgehog signaling plays a role in the regeneration and patterning processes: an increase or reduction of fin bony elements results when this signaling is activated or disrupted, respectively. The tail fin also regenerates but, in contrast with pectoral fins, regeneration can resume after release from the arrest caused by hedgehog inhibition. A comparative analysis of fin phenotypes obtained after retinoic acid treatment or altering the hedgehog signaling levels during regeneration allowed us to assign a limb tetrapod equivalent segment to Polypterus fin skeletal structures, thus providing clues to the origin of the autopod. We propose that appendage regeneration was a common property of vertebrates during the fin to limb transition.

  7. Performance of synchronized fins in biomimetic propulsion.

    PubMed

    Shoele, Kourosh; Zhu, Qiang

    2015-03-30

    By using a two-dimensional model of ray fins, we numerically investigate the thrust generation by closely-coupled fins with an immersed boundary approach. The concentration is on the performance enhancement through fin-fin interactions and the underlying vortex control mechanisms in three representative systems, a two-fin tandem configuration, a two-fin parallel configuration, and a three-fin triangular configuration. In all these systems the thrust generation can be significantly increased in comparison with single fins. Unlike previous studies of tandem fins, in which the gap and phase lag between the two fins were considered separately, our study shows that the dynamics of the system is determined by a parameter that combines these two (the global phase difference). The optimal performance occurs as this parameter is around π (destructive mode), and the worst performance occurs when it is around 0 (constructive mode). Interestingly, contrary to the vorticity cancellation scenario implied by its name, our simulations show that in the destructive mode there is in fact a wake re-organization mechanism, during which vortices with the same rotational direction shed from the two fins are attracted towards each other and merge. Subsequently, the wake downstream becomes a strong and well-organized reverse Kármán vortex street, which explains the increased thrust. In the parallel system, the best performance occurs in cases when the two fins are in opposites phases. Both the thrust and efficiency increase as the gap between the fins decreases, until a symmetry-breaking instability occurs in the wake and the efficiency starts plunging due to the increase in lateral force generation. In the triangular formation, the highest thrust generation also occurs in the destructive mode. However, no further increase in performance is observed compared with the tandem system.

  8. Fin-mutant female zebrafish (Danio rerio) exhibit differences in association preferences for male fin length

    PubMed Central

    Gumm, Jennifer M.; Snekser, Jennifer L.; Iovine, M. Kathryn

    2009-01-01

    Females often choose to associate with males that have exaggerated traits. In fishes, this may reflect an overall preference for larger size in a potential mate. Female zebrafish (Danio rerio) prefer males with larger bodies but not longer fins. The availability of mutant and transgenic strains of zebrafish make this a unique model system in which to study the role of phenotypic variation in social and sexual behavior. We used mutant strains of zebrafish with truncated (short fin) and exaggerated (long fin) fins to further examine female preferences for fin length in dichotomous association tests. Wild type females showed no preferences between wild type males and short fin mutant males or between wild type males and long fin mutant males. short fin females also showed no preference for short fin males or wild type males while long fin females preferred to associate with long fin males over wild type males. These results suggest that the single gene long fin mutation that results in altered fin morphological may also be involved in a related female association preference. PMID:18848866

  9. Stiffness Modulation of Rayed Fins by Curvature

    NASA Astrophysics Data System (ADS)

    Nguyen, Khoi; Yu, Ning; Venkadesan, Madhusudhan; Bandi, Mahesh; Mandre, Shreyas

    2016-11-01

    Fishes with rayed fins comprise over 99% of all extant fish species. Multifunctional use of fins, from propulsion to station holding, requires substantial modulation of stiffness. We propose that fishes stiffen the fin by curving it transverse to its length. This effect is similar to stiffening a dollar bill by curling it because of curvature-induced coupling of out-of-plane bending with in-plane stretching. Unlike a piece of paper, rayed fins are a composite of rays and membranes. We model this as parallel elastic beams (rays) with springy interconnections (membranes). Our analysis shows that the key parameters stiffening the fin are the ray anisotropy to bending, the misalignment of principal bending directions of adjacent rays, and the membrane elasticity. The composite fin stiffens when the principal bending directions of adjacent rays are misaligned due to fin curvature, which necessarily causes the membrane to stretch. Unlike a homogenous thin sheet, composite rayed structures are able to mimic curvature-induced stiffening by using misaligned rays even if the fin appears geometrically flat. Preliminary radiographic evidence from the rays of fish fins supports such a mechanism. Funding by Human Frontier Science Program.

  10. Heat exchanger with transpired, highly porous fins

    DOEpatents

    Kutscher, Charles F.; Gawlik, Keith

    2002-01-01

    The heat exchanger includes a fin and tube assembly with increased heat transfer surface area positioned within a hollow chamber of a housing to provide effective heat transfer between a gas flowing within the hollow chamber and a fluid flowing in the fin and tube assembly. A fan is included to force a gas, such as air, to flow through the hollow chamber and through the fin and tube assembly. The fin and tube assembly comprises fluid conduits to direct the fluid through the heat exchanger, to prevent mixing with the gas, and to provide a heat transfer surface or pathway between the fluid and the gas. A heat transfer element is provided in the fin and tube assembly to provide extended heat transfer surfaces for the fluid conduits. The heat transfer element is corrugated to form fins between alternating ridges and grooves that define flow channels for directing the gas flow. The fins are fabricated from a thin, heat conductive material containing numerous orifices or pores for transpiring the gas out of the flow channel. The grooves are closed or only partially open so that all or substantially all of the gas is transpired through the fins so that heat is exchanged on the front and back surfaces of the fins and also within the interior of the orifices, thereby significantly increasing the available the heat transfer surface of the heat exchanger. The transpired fins also increase heat transfer effectiveness of the heat exchanger by increasing the heat transfer coefficient by disrupting boundary layer development on the fins and by establishing other beneficial gas flow patterns, all at desirable pressure drops.

  11. Hydrodynamic optimality of ribbon fin shapes

    NASA Astrophysics Data System (ADS)

    Bale, Rahul; Maciver, Malcolm; Patankar, Neelesh

    2011-11-01

    The primary mode of propulsion in gymnotiform and balistiform swimmers is via the undulation of anal and/or dorsal fins, commonly referred to as ribbon fins, attached to a more or less rigid body. Ribbon fins usually have a convex shape as opposed to a rectangular or concave profile. In this work we investigate if there is a hydrodynamic basis underlying this observation. Fully resolved fluid dynamics computations are performed to calculate the mechanical cost of transport (COT) as a measure of swimming efficiency of the fin. We find that the ribbon fin of a black ghost knifefish has lower COT compared to a hypothetical rectangular ribbon fin. In order to quantify this difference in COT between the two fin shapes, we obtain scaling for COT in terms of various parameters which affect the swimming performance of the fin. Using scaling arguments we address the question of how a convex profile, commonly observed in gymnotiform and balistiform swimmers, is optimal compared to rectangular or concave shapes. NSF support is gratefully acknowledged.

  12. Effect of Fin Passage Length on Optimization of Cylinder Head Cooling Fins

    NASA Technical Reports Server (NTRS)

    Siegel, R.; Graham, R. W.

    1977-01-01

    The heat transfer performance of baffled cooling fins on cylinder heads of small, air-cooled, general-aviation aircraft engines was analyzed to determine the potential for improving cooling fin design. Flow baffles were assumed to be installed tightly against the fin end edges, an ideal baffle configuration for guiding all flow between the fins. A rectangular flow passage is thereby formed between each set of two adjacent fins, the fin base surface, and the baffle. These passages extend around each side of the cylinder head, and the cooling air absorbs heat as it flows within them. For each flow passage length, the analysis was concerned with optimizing fin spacing and thickness to achieve the best heat transfer for each fin width. Previous literature has been concerned mainly with maximizing the local fin conductance and has not considered the heating of the gas in the flow direction, which leads to higher wall temperatures at the fin passage exits. If the fins are close together, there is a large surface area, but the airflow is restricted.

  13. Original Sin and T. E. Hulme's Aesthetics

    ERIC Educational Resources Information Center

    Kishler, Thomas C.

    1976-01-01

    T. E. Hulme, a vigorous opponent of romanticism in art, poetry, and philosophy, insisted that the underlying flaw of the romantic view was its rejection of the dogma of Original Sin and the fall of man. His views are explored for the significant bearing they have on the development of aesthetic insight and indirectly on value and outlook.…

  14. Artificial muscle actuators in biorobotic fish fins.

    PubMed

    Phelan, Christopher T; Macdonald, Robert J; Tangorra, James L

    2009-01-01

    Artificial muscle technologies offer the possibility of designing robotic systems that take full advantage of biological architectures. Of current artificial muscle technologies, nickel titanium (Ni-Ti) shape memory alloys are among a few that are readily usable by engineering labs without specialized skills in material science and/or chemistry. Ni-Ti actuators are now being used to replace servomotors in biorobotic fins. This has significantly reduced the volume that is required for actuators, and will enable several fins to be integrated into a multi finned, flexible bodied, biorobotic fish.

  15. Structure of the tail fin in teleosts.

    PubMed

    Becerra, J; Montes, G S; Bexiga, S R; Junqueira, L C

    1983-01-01

    A morphologic study of the structure of the tail fin in eight species of teleosts was performed by aid of the Picrosirius-polarization method, which is a specific histochemical method for the detection of collagen in tissue sections. This structure is composed mainly of skeletal elements, the fin rays, covered by skin. Fin rays are bound to each other and to the surrounding tissues by a series of collagenous ligaments forming a complex, highly pliable and resistant structure. Although the general structural pattern of tail fins was consistent in all species studied, the comparative aspects reported in this paper show that variations in the form and size of their components are responsible for the morphologic diversities which are closely related to specific functional adaptations. Morphometric data on the number and size of actinotrichia in normal adult specimens are presented.

  16. Pectoral fins and paternal quality in sticklebacks.

    PubMed Central

    Künzler, R; Bakker, T C

    2000-01-01

    Sexual selection through female mate choice exerts a strong selection pressure on males' sexual traits, particularly when direct benefits are involved. In species with male parental care, one would expect sexual selection to favour paternal quality, for instance through selection on morphological structures which promote quality. We experimentally studied the influence of pectoral fins on paternal quality in male three-spined sticklebacks (Gasterosteus aculeatus L.). After reductions of fin area to different degrees, similar-sized males had to perform a complete reproductive cycle in enclosures in the field. The collected data on fanning behaviour and egg development showed that a reduction in pectoral fin size affected paternal quality probably through an increased beat frequency of the pectorals. Thus, pectoral fins can potentially signal paternal quality to choosy females. PMID:10874749

  17. Babar: Sin(2beta) With Charm

    SciTech Connect

    Grenier, P.; /Ecole Polytechnique /Clermont-Ferrand U.

    2006-04-12

    We present measurements of time-dependent CP asymmetries of neutral B decays to several charm and charmonium final states. Data have been collected with the BABAR detector at the PEP-II storage ring at the Stanford Linear Accelerator Center. In the absence of penguin contribution, the Standard Model predicts the time-dependent CP asymmetry parameters S and C are to be {eta}{sub CP} sin(2{beta}) and 0, respectively.

  18. The art of fin regeneration in zebrafish.

    PubMed

    Pfefferli, Catherine; Jaźwińska, Anna

    2015-04-01

    The zebrafish fin provides a valuable model to study the epimorphic type of regeneration, whereby the amputated part of the appendage is nearly perfectly replaced. To accomplish fin regeneration, two reciprocally interacting domains need to be established at the injury site, namely a wound epithelium and a blastema. The wound epithelium provides a supporting niche for the blastema, which contains mesenchyme-derived progenitor cells for the regenerate. The fate of blastemal daughter cells depends on their relative position with respect to the fin margin. The apical compartment of the outgrowth maintains its undifferentiated character, whereas the proximal descendants of the blastema progressively switch from the proliferation program to the morphogenesis program. A delicate balance between self-renewal and differentiation has to be continuously adjusted during the course of regeneration. This review summarizes the current knowledge about the cellular and molecular mechanisms of blastema formation, and discusses several studies related to the regulation of growth and morphogenesis during fin regeneration. A wide range of canonical signaling pathways has been implicated during the establishment and maintenance of the blastema. Epigenetic mechanisms play a crucial role in the regulation of cellular plasticity during the transition between differentiation states. Ion fluxes, gap-junctional communication and protein phosphatase activity have been shown to coordinate proliferation and tissue patterning in the caudal fin. The identification of the downstream targets of the fin regeneration signals and the discovery of mechanisms integrating the variety of input pathways represent exciting future aims in this fascinating field of research.

  19. The art of fin regeneration in zebrafish

    PubMed Central

    Pfefferli, Catherine

    2015-01-01

    Abstract The zebrafish fin provides a valuable model to study the epimorphic type of regeneration, whereby the amputated part of the appendage is nearly perfectly replaced. To accomplish fin regeneration, two reciprocally interacting domains need to be established at the injury site, namely a wound epithelium and a blastema. The wound epithelium provides a supporting niche for the blastema, which contains mesenchyme‐derived progenitor cells for the regenerate. The fate of blastemal daughter cells depends on their relative position with respect to the fin margin. The apical compartment of the outgrowth maintains its undifferentiated character, whereas the proximal descendants of the blastema progressively switch from the proliferation program to the morphogenesis program. A delicate balance between self‐renewal and differentiation has to be continuously adjusted during the course of regeneration. This review summarizes the current knowledge about the cellular and molecular mechanisms of blastema formation, and discusses several studies related to the regulation of growth and morphogenesis during fin regeneration. A wide range of canonical signaling pathways has been implicated during the establishment and maintenance of the blastema. Epigenetic mechanisms play a crucial role in the regulation of cellular plasticity during the transition between differentiation states. Ion fluxes, gap‐junctional communication and protein phosphatase activity have been shown to coordinate proliferation and tissue patterning in the caudal fin. The identification of the downstream targets of the fin regeneration signals and the discovery of mechanisms integrating the variety of input pathways represent exciting future aims in this fascinating field of research. PMID:27499869

  20. Stem sarcopterygians have primitive polybasal fin articulation

    PubMed Central

    Zhu, Min; Yu, Xiaobo

    2009-01-01

    Among osteichthyans, basal actinopterygian fishes (e.g. paddlefish and bowfins) have paired fins with three endoskeletal components (pro-, meso- and metapterygia) articulating with polybasal shoulder girdles, while sarcopterygian fishes (lungfish, coelacanths and relatives) have paired fins with one endoskeletal component (metapterygium) articulating with monobasal shoulder girdles. In the fin–limb transition, the origin of the sarcopterygian paired fins triggered new possibilities of fin articulation and movement, and established the proximal segments (stylopod and zeugopod) of the presumptive tetrapod limb. Several authors have stated that the monobasal paired fins in sarcopterygians evolved from a primitive polybasal condition. However, the fossil record has been silent on whether and when the inferred transition took place. Here we describe three-dimensionally preserved shoulder girdles of two stem sarcopterygians (Psarolepis and Achoania) from the Lower Devonian of Yunnan, which demonstrate that stem sarcopterygians have polybasal pectoral fin articulation as in basal actinopterygians. This finding provides a phylogenetic and temporal constraint for studying the origin of the stylopod, which must have originated within the stem sarcopterygian lineage through the loss of the propterygium and mesopterygium. PMID:19324642

  1. Pelvic girdle and fin of Tiktaalik roseae.

    PubMed

    Shubin, Neil H; Daeschler, Edward B; Jenkins, Farish A

    2014-01-21

    A major challenge in understanding the origin of terrestrial vertebrates has been knowledge of the pelvis and hind appendage of their closest fish relatives. The pelvic girdle and appendage of tetrapods is dramatically larger and more robust than that of fish and contains a number of structures that provide greater musculoskeletal support for posture and locomotion. The discovery of pelvic material of the finned elpistostegalian, Tiktaalik roseae, bridges some of these differences. Multiple isolated pelves have been recovered, each of which has been prepared in three dimensions. Likewise, a complete pelvis and partial pelvic fin have been recovered in association with the type specimen. The pelves of Tiktaalik are paired and have broad iliac processes, flat and elongate pubes, and acetabulae that form a deep socket rimmed by a robust lip of bone. The pelvis is greatly enlarged relative to other finned tetrapodomorphs. Despite the enlargement and robusticity of the pelvis of Tiktaalik, it retains primitive features such as the lack of both an attachment for the sacral rib and an ischium. The pelvic fin of Tiktaalik (NUFV 108) is represented by fin rays and three endochondral elements: other elements are not preserved. The mosaic of primitive and derived features in Tiktaalik reveals that the enhancement of the pelvic appendage of tetrapods and, indeed, a trend toward hind limb-based propulsion have antecedents in the fins of their closest relatives.

  2. Pelvic girdle and fin of Tiktaalik roseae

    PubMed Central

    Shubin, Neil H.; Daeschler, Edward B.; Jenkins, Farish A.

    2014-01-01

    A major challenge in understanding the origin of terrestrial vertebrates has been knowledge of the pelvis and hind appendage of their closest fish relatives. The pelvic girdle and appendage of tetrapods is dramatically larger and more robust than that of fish and contains a number of structures that provide greater musculoskeletal support for posture and locomotion. The discovery of pelvic material of the finned elpistostegalian, Tiktaalik roseae, bridges some of these differences. Multiple isolated pelves have been recovered, each of which has been prepared in three dimensions. Likewise, a complete pelvis and partial pelvic fin have been recovered in association with the type specimen. The pelves of Tiktaalik are paired and have broad iliac processes, flat and elongate pubes, and acetabulae that form a deep socket rimmed by a robust lip of bone. The pelvis is greatly enlarged relative to other finned tetrapodomorphs. Despite the enlargement and robusticity of the pelvis of Tiktaalik, it retains primitive features such as the lack of both an attachment for the sacral rib and an ischium. The pelvic fin of Tiktaalik (NUFV 108) is represented by fin rays and three endochondral elements: other elements are not preserved. The mosaic of primitive and derived features in Tiktaalik reveals that the enhancement of the pelvic appendage of tetrapods and, indeed, a trend toward hind limb-based propulsion have antecedents in the fins of their closest relatives. PMID:24449831

  3. Swimming performance of biomimetic trapezoidal elastic fins

    NASA Astrophysics Data System (ADS)

    Spadaro, Michael; Yeh, Peter; Alexeev, Alexander

    2016-11-01

    Using three-dimensional computer simulations, we probe the biomimetic free-swimming of trapezoidal elastic plates plunging sinusoidally in a viscous fluid, varying the frequency of oscillations and plate geometry. We choose the elastic trapezoidal plate geometry because it more closely approximates the shape of real caudal fish fins. Indeed, caudal fins are found in nature in a variety of trapezoidal shapes with different aspect ratios. Because of this, we perform our simulations using plates with aspect ratios varying from the cases where the plate has a longer leading edge and to plates with a longer trailing edge. We find that the trapezoidal fins with the longer trailing edge are less efficient than the rectangular fins at the equivalent oscillation frequencies. This is surprising because many fish found in nature have a widening tail. We relate this to the fact that our model considers fins with uniform thickness whereas fish uses tapered fins. Our results will be useful for the design of biomimetic swimming devices as well as understanding more closely the physics of fish swimming.

  4. Sin3b Interacts with Myc and Decreases Myc Levels*

    PubMed Central

    Garcia-Sanz, Pablo; Quintanilla, Andrea; Lafita, M. Carmen; Moreno-Bueno, Gema; García-Gutierrez, Lucia; Tabor, Vedrana; Varela, Ignacio; Shiio, Yuzuru; Larsson, Lars-Gunnar; Portillo, Francisco; Leon, Javier

    2014-01-01

    Myc expression is deregulated in many human cancers. A yeast two-hybrid screen has revealed that the transcriptional repressor Sin3b interacts with Myc protein. Endogenous Myc and Sin3b co-localize and interact in the nuclei of human and rat cells, as assessed by co-immunoprecipitation, immunofluorescence, and proximity ligation assay. The interaction is Max-independent. A conserved Myc region (amino acids 186–203) is required for the interaction with Sin3 proteins. Histone deacetylase 1 is recruited to Myc-Sin3b complexes, and its deacetylase activity is required for the effects of Sin3b on Myc. Myc and Sin3a/b co-occupied many sites on the chromatin of human leukemia cells, although the presence of Sin3 was not associated with gene down-regulation. In leukemia cells and fibroblasts, Sin3b silencing led to Myc up-regulation, whereas Sin3b overexpression induced Myc deacetylation and degradation. An analysis of Sin3b expression in breast tumors revealed an association between low Sin3b expression and disease progression. The data suggest that Sin3b decreases Myc protein levels upon Myc deacetylation. As Sin3b is also required for transcriptional repression by Mxd-Max complexes, our results suggest that, at least in some cell types, Sin3b limits Myc activity through two complementary activities: Mxd-dependent gene repression and reduction of Myc levels. PMID:24951594

  5. Loads and Pressures on Axisymmetric Bodies with Cruciform Fins

    NASA Technical Reports Server (NTRS)

    Dillenius, M. F. E.; Smith, C. A.

    1983-01-01

    NSWCDM computer program calculates aerodynamic loading and pressure distributions on supersonic configurations consisting of axisymmetric bodies with cruciform or planar canard and tail fins. Versatile program allows for configuration pitched and rolled, and fins deflected. Tail fins are interdigitated with respect to forward fins.

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

    PubMed

    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 <0.01 to 34 ng/mL, with MMHg averaging 62 ± 7% of total Hg. The highest concentrations of MMHg and total Hg were observed in both fins and soup from large, high trophic level 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.

  7. Propulsive Forces of a Biomimetic Undulating Fin

    NASA Astrophysics Data System (ADS)

    Kalumuck, Kenneth; Brandt, Alan; Armand, Mehran

    2007-11-01

    Understanding gained from much recent work on force production mechanisms of aquatic organisms holds great promise for improved undersea vehicle propulsion and maneuvering. One class of fish locomotion is that of the median fin utilized by animals such as squid, cuttlefish, knifefish, and seahorse. It is characterized by undulatory motion that creates traveling waves along the fin. Results of experiments conducted on a submerged mechanical underwater undulating fin test bed are presented. The 0.5 m long fin is mounted to a cylindrical body and consists of a flexible skin attached to ribs driven by an adjustable cam mechanism and variable speed motor that enables changing the characteristics of the undulating wave(s). Forces produced were measured in a captive mode under quiescent conditions as well in the presence of an ambient current. Propulsive forces are characterized as a function of the fin width, oscillation frequency, amplitude, and wavelength. Free swimming experiments were also conducted to determine the point of self propulsion. Flow field structure visualization using dye tracers is presented for selected cases. Estimates of performance and applications for use with larger scale vehicles are discussed.

  8. Visualization of pool boiling on plain micro-fins and micro- fins with sintered perforated foil

    NASA Astrophysics Data System (ADS)

    Pastuszko, R.; Kaniowski, R.

    2016-09-01

    The paper presents visualization investigations of boiling heat transfer over enhanced structures. The experiments were carried out for two kinds of enhanced surfaces: an array of 0.5 mm high micro-fins without covering (plain micro-fins designated as MF) and the surfaces made by sintering micro-fin tops with the copper perforated foil (MF+F). Pool boiling data at atmospheric pressure were obtained for saturated water, ethanol, FC-72 and Novec-649. Visualization studies aimed at identifying nucleation sites and determining the diameter and frequency of departing bubbles. Different pool boiling mechanisms were observed for the plain micro-fins and micro-fins covered with the porous structure.

  9. RF power FinFET transistors with a wide drain-extended fin

    NASA Astrophysics Data System (ADS)

    Chen, Bo-Yuan; Chen, Kun-Ming; Chiu, Chia-Sung; Huang, Guo-Wei; Chen, Hsiu-Chih; Chen, Chun-Chi; Hsueh, Fu-Kuo; Chen, Min-Cheng; Chang, Edward Yi

    2017-04-01

    Drain-extended FinFET transistors for RF power applications have been fabricated and is presented in this paper. Power FinFETs with a wide drain extension are proposed to reduce the drain resistance. Compared with conventional drain-extended FinFETs, our proposed new devices exhibit lower on-resistances and better high-frequency performances while keeping a similar breakdown voltage. The enhancements of the on-resistance and peak cutoff frequency are 16 and 56%, respectively, under an optimal drain-extension layout. These experimental results suggest that FinFET transistors with a wide drain extension could be used for RF power applications, increasing the possibility of integrating RF power parts into future FinFET system-on-a-chip technologies.

  10. Role of Pectoral Fin Flexibility in Robotic Fish Performance

    NASA Astrophysics Data System (ADS)

    Bazaz Behbahani, Sanaz; Tan, Xiaobo

    2017-03-01

    Pectoral fins play a vital role in the maneuvering and locomotion of fish, and they have become an important actuation mechanism for robotic fish. In this paper, we explore the effect of flexibility of robotic fish pectoral fins on the robot locomotion performance and mechanical efficiency. A dynamic model for the robotic fish is presented, where the flexible fin is modeled as multiple rigid elements connected via torsional springs and dampers. Blade element theory is used to capture the hydrodynamic force on the fin. The model is validated with experimental results obtained on a robotic fish prototype, equipped with 3D-printed fins of different flexibility. The model is then used to analyze the impacts of fin flexibility and power/recovery stroke speed ratio on the robot swimming speed and mechanical efficiency. It is found that, in general, flexible fins demonstrate advantages over rigid fins in speed and efficiency at relatively low fin-beat frequencies, while rigid fins outperform flexible fins at higher frequencies. For a given fin flexibility, the optimal frequency for speed performance differs from the optimal frequency for mechanical efficiency. In addition, for any given fin, there is an optimal power/recovery stroke speed ratio, typically in the range of 2-3, that maximizes the speed performance. Overall, the presented model offers a promising tool for fin flexibility and gait design, to achieve speed and efficiency objectives for robotic fish actuated with pectoral fins.

  11. Blue shark Prionace glauca fin-to-carcass-mass ratios in Spain and implications for finning ban enforcement.

    PubMed

    Santana-Garcon, J; Fordham, S; Fowler, S

    2012-04-01

    This study examines the processing of fins from blue sharks Prionace glauca caught by the Spanish longline fleet and landed in Vigo, Spain, and implications of these practices for enforcing the E.U. ban on shark finning, which relies on a maximum fin-to-carcass-mass ratio. Two major sources of variability in fin-to-carcass ratios are quantified and discussed: (1) the fin set (type and number of fins retained from each shark) and (2) the cutting method used to separate fins from carcasses. The significant differences in fin-to-carcass-mass ratios between fin sets or cutting procedure demonstrates that the ratio limit is problematic and, conclusively, in order to facilitate proper enforcement, fishermen should be required to land all sharks with the fins still naturally attached to the bodies.

  12. Experimental and numerical investigation on air-side performance of fin-and-tube heat exchangers with various fin patterns

    SciTech Connect

    Tang, L.H.; Zeng, M.; Wang, Q.W.

    2009-07-15

    Air-side heat transfer and friction characteristics of five kinds of fin-and-tube heat exchangers, with the number of tube rows (N = 12) and the diameter of tubes (D{sub o} = 18 mm), have been experimentally investigated. The test samples consist of five types of fin configurations: crimped spiral fin, plain fin, slit fin, fin with delta-wing longitudinal vortex generators (VGs) and mixed fin with front 6-row vortex-generator fin and rear 6-row slit fin. The heat transfer and friction factor correlations for different types of heat exchangers were obtained with the Reynolds numbers ranging from 4000 to 10000. It was found that crimped spiral fin provides higher heat transfer and pressure drop than the other four fins. The air-side performance of heat exchangers with the above five fins has been evaluated under three sets of criteria and it was shown that the heat exchanger with mixed fin (front vortex-generator fin and rear slit fin) has better performance than that with fin with delta-wing vortex generators, and the slit fin offers best heat transfer performance at high Reynolds numbers. Based on the correlations of numerical data, Genetic Algorithm optimization was carried out, and the optimization results indicated that the increase of VG attack angle or length, or decrease of VG height may enhance the performance of vortex-generator fin. The heat transfer performances for optimized vortex-generator fin and slit fin at hand have been compared with numerical method. (author)

  13. A mathematical model of elastic fin micromotors

    NASA Astrophysics Data System (ADS)

    Lu, Pin; Lee, Kwok Hong; Piang Lim, Siak; Dong, Shuxiang; Zhong Lin, Wu

    2000-08-01

    In the present work, a simplified mathematical model of ultrasonic elastic fin micromotors has been developed. According to the operating principle of this type of motor, the motions of a rotor in each cycle of the stator vibration are divided into several stages based on whether the fin tip and the stator are in contact with slip, contact without slip or separation. The equations of motion of the rotor in each stage are derived. The valid range of the model has been discussed through numerical examples. This work provides an initial effort to construct a model for the elastic fin motor by considering the dynamical deformation of the rotor as well as the intermittent contacts.

  14. The effect of fin ray flexural rigidity on the propulsive forces generated by a biorobotic fish pectoral fin.

    PubMed

    Tangorra, James L; Lauder, George V; Hunter, Ian W; Mittal, Rajat; Madden, Peter G A; Bozkurttas, Meliha

    2010-12-01

    A biorobotic pectoral fin was developed and used to study how the flexural rigidities of fin rays within a highly deformable fish fin affect the fin's propulsive forces. The design of the biorobotic fin was based on a detailed analysis of the pectoral fin of the bluegill sunfish (Lepomis macrochirus). The biorobotic fin was made to execute the kinematics used by the biological fin during steady swimming, and to have structural properties that modeled those of the biological fin. This resulted in an engineered fin that had a similar interaction with the water as the biological fin and that created close approximations of the three-dimensional motions, flows, and forces produced by the sunfish during low speed, steady swimming. Experimental trials were conducted during which biorobotic fins of seven different stiffness configurations were flapped at frequencies from 0.5 to 2.0 Hz in flows with velocities that ranged from 0 to 270 mm s(-1). During these trials, thrust and lift forces were measured, kinematics were recorded in three dimensions, and digital particle image velocimetry was used to evaluate flow hydrodynamics. The results of the trials revealed that slight changes to the fin's mechanical properties or to the operating conditions can have significant impact on the direction, magnitude and time course of the propulsive forces. In general, the magnitude of the 2-D (thrust and lift) propulsive force scaled with fin ray stiffness, and increased as the fin's flapping speed increased or as the velocity of the flow decreased.

  15. Thermoelectric generator with hinged assembly for fins

    DOEpatents

    Purdy, David L.; Shapiro, Zalman M.; Hursen, Thomas F.; Maurer, Gerould W.

    1976-11-02

    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.

  16. Ultra-high aspect-ratio FinFET technology

    NASA Astrophysics Data System (ADS)

    Jovanović, Vladimir; Suligoj, Tomislav; Poljak, Mirko; Civale, Yann; Nanver, Lis K.

    2010-09-01

    FinFETs with ultra-large height-to-width ratio have been processed on (1 1 0) bulk silicon wafers by employing crystallographic etching of silicon with TMAH, which results in nearly vertical sidewalls with a (1 1 1)/<1 1 2> surface orientation. Tall fins, which corresponds to wide transistor channels per single fin offer more efficient use of the silicon area and improved performance for multi-fin devices in high-frequency analog applications. N-channel FinFETs with 1.9-nm-wide fins demonstrate the downscaling potential of the technology and devices with a height of the active part of the fin of 625 nm have the largest aspect-ratio of the fins reported thus far. Both devices with highly and moderately scaled fin-widths exhibit excellent subthreshold performance while electrons have higher mobility in 15-nm-wide FinFETs, which gives them larger on-state currents. The comparison between FinFETs and wide tri-gate devices shows that FinFETs have better current drivability in this simple process, even with larger source/drain series resistances. The differences in threshold voltage and low-field electron mobility between 1.9-nm-wide and 15-nm-wide FinFETs have been related to the increase in subband energies due to carrier confinement in the extremely narrow fins.

  17. Disease, suffering, and sin: one Anglican's perspective.

    PubMed

    Foster, Claire

    2006-08-01

    This article explores some of the implications of understanding sin as failure of perception. The theological underpinning of the argument is the choice made in the Garden of Eden to eat the fruit of the tree of knowledge rather than the fruit of the tree of life, or wisdom. This has led to distorted perception, in which all things are seen as having separate, independent existences rather than joined together by their common divine source and their deep interrelatedness in the covenant made with God. The article discusses the fascination with the principle of respect for autonomy in the light of this theology. It also looks at perceptions of the HIV/AIDS crisis in Africa. It finishes with a definition of repentance that makes right perception possible.

  18. Investigation of negative bias temperature instability dependence on fin width of silicon-on-insulator-fin-based field effect transistors

    SciTech Connect

    Young, Chadwin D. Wang, Zhe; Neugroschel, Arnost; Majumdar, Kausik; Matthews, Ken; Hobbs, Chris

    2015-01-21

    The fin width dependence of negative bias temperature instability (NBTI) of double-gate, fin-based p-type Field Effect Transistors (FinFETs) fabricated on silicon-on-insulator (SOI) wafers was investigated. The NBTI degradation increased as the fin width narrowed. To investigate this phenomenon, simulations of pre-stress conditions were employed to determine any differences in gate oxide field, fin band bending, and electric field profile as a function of the fin width. The simulation results were similar at a given gate stress bias, regardless of the fin width, although the threshold voltage was found to increase with decreasing fin width. Thus, the NBTI fin width dependence could not be explained from the pre-stress conditions. Different physics-based degradation models were evaluated using specific fin-based device structures with different biasing schemes to ascertain an appropriate model that best explains the measured NBTI dependence. A plausible cause is an accumulation of electrons that tunnel from the gate during stress into the floating SOI fin body. As the fin narrows, the sidewall device channel moves in closer proximity to the stored electrons, thereby inducing more band bending at the fin/dielectric interface, resulting in a higher electric field and hole concentration in this region during stress, which leads to more degradation. The data obtained in this work provide direct experimental proof of the effect of electron accumulation on the threshold voltage stability in FinFETs.

  19. Successful euthanasia of a juvenile fin whale.

    PubMed Central

    Daoust, P Y; Ortenburger, A I

    2001-01-01

    A stranded juvenile fin whale was successfully euthanized with an intravenous injection of sedative and cardioplegic drugs. Veterinarians may face a number of serious difficulties if called to perform this task, and advance preparation is required for successful euthanasia of these animals. Images Figure 1. PMID:11272456

  20. Flutter analysis of a sounding rocket fin

    NASA Astrophysics Data System (ADS)

    Natori, M.; Onoda, J.; Kitamura, T.

    The procedures used to characterize the flutter behavior of the fin of the ISAS M-3S II launch vehicle (capable of launching 750 kg to LEO) are described. Consideration is given to supersonic flutter computations, single-point-excitation and vibration testing, construction of flutter models, and transonic wind-tunnel tests. Tables, graphs, diagrams, and photographs are provided.

  1. Wing design and morphology of the harbor porpoise dorsal fin.

    PubMed

    Pavlov, Vadim V

    2003-12-01

    The correlation between skin structure and hydrodynamic design of the dorsal fin of the harbor porpoise (Phocoena phocoena) was examined. For the study of fin morphology and geometry, a scheme of sampling representing a two-parameter mesh on the fin surface was used. At each data point the thickness of the epidermis, papillary and subpapillary layers of the dermis, the ligamentous layer of the fin, as well as the angle formed by the direction of dermal ridges and the fin root chord were measured. On the basis of fin cross-sections the three-dimensional surface models of the fin in a 1 : 1 scale were created with a CAD program. The shape of the model was evaluated by the wing and hydrofoil parameters (angle of leading edge sweep, leading edge radius, maximum thickness of the fin cross-section, and position of maximum thickness from the leading edge). Hydrodynamic performance of the fin cross-sections was studied with a CFD program. Regional variability of the parameters of morphology was compared with spanwise variability of the parameters of cross-sectional geometry. It was found that skin structure parameters correlate with the hydrodynamically relevant parameters of the fin and fin cross-sections. Regularities of skin structure of the harbor porpoise dorsal fin are considered indirect evidence of the adaptation of porpoise skin to the fin flow.

  2. A high aspect ratio silicon-fin FinFET fabricated upon SOI wafer

    NASA Astrophysics Data System (ADS)

    Liaw, Yue-Gie; Liao, Wen-Shiang; Wang, Mu-Chun; Lin, Cheng-Li; Zhou, Bin; Gu, Haoshuang; Li, Deshi; Zou, Xuecheng

    2016-12-01

    Three dimensional (3-D) FinFET devices with an ultra-high Si-fin aspect ratio (Height/Width = 82.9 nm/8.6 nm) have been developed after integrating a 14 Å nitrided gate oxide upon the silicon on insulator (SOI) wafers through an advanced CMOS logic platform. The drive current (ION), off current (IOFF), subthreshold swing (SS), drain-induced barrier lowering (DIBL) and transistor gate delay of 30 nm gate length (Lg) of FinFETs illustrate the promising device performance. The TCAD simulations demonstrate that both threshold voltage (Vth) and off current can be adjusted appropriately through the full silicidation (FUSI) of CoSi2 gate engineering. Moreover, the drive currents of n- and p-channel FinFETs are able to be further enhanced once applying the raised Source/Drain (S/D) approach technology for reducing the S/D resistance drastically.

  3. 14 CFR 23.445 - Outboard fins or winglets.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... surfaces or wings, the horizontal surfaces or wings must be designed for their maximum load in combination... wings by the fins or winglets. (b) If outboard fins or winglets extend above and below the...

  4. 14 CFR 23.445 - Outboard fins or winglets.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... surfaces or wings, the horizontal surfaces or wings must be designed for their maximum load in combination... wings by the fins or winglets. (b) If outboard fins or winglets extend above and below the...

  5. 14 CFR 23.445 - Outboard fins or winglets.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... surfaces or wings, the horizontal surfaces or wings must be designed for their maximum load in combination... wings by the fins or winglets. (b) If outboard fins or winglets extend above and below the...

  6. 14 CFR 23.445 - Outboard fins or winglets.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... surfaces or wings, the horizontal surfaces or wings must be designed for their maximum load in combination... wings by the fins or winglets. (b) If outboard fins or winglets extend above and below the...

  7. 14 CFR 23.445 - Outboard fins or winglets.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... surfaces or wings, the horizontal surfaces or wings must be designed for their maximum load in combination... wings by the fins or winglets. (b) If outboard fins or winglets extend above and below the...

  8. Modeling of nonlinear thermal resistance in FinFETs

    NASA Astrophysics Data System (ADS)

    Krishna Kompala, Bala; Kushwaha, Pragya; Agarwal, Harshit; Khandelwal, Sourabh; Duarte, Juan-Pablo; Hu, Chenming; Singh Chauhan, Yogesh

    2016-04-01

    In this paper, self-consistent three-dimensional (3D) device simulations for exact analysis of thermal transport in FinFETs are performed. We analyze the temperature rise in FinFET devices with the variation in the number of fins (N fin), shape of fins and fin pitch (F pitch). We investigate that the thermal resistance R th has nonlinear dependency on N fin and F pitch. We formulate a model for thermal resistance behavior correctly with N fin and F pitch variation. The proposed formulation is implemented in industry standard Berkeley short-channel independent gate FET model for common multi-gate transistors (BSIM-CMG) and validated with both experimental data and TCAD simulations.

  9. Embryonic development of fin spines in Callorhinchus milii (Holocephali); implications for chondrichthyan fin spine evolution.

    PubMed

    Jerve, Anna; Johanson, Zerina; Ahlberg, Per; Boisvert, Catherine

    2014-01-01

    Fin spines are commonly known from fossil gnathostomes (jawed vertebrates) and are usually associated with paired and unpaired fins. They are less common among extant gnathostomes, being restricted to the median fins of certain chondrichthyans (cartilaginous fish), including chimaerids (elephant sharks) and neoselachians (sharks, skates, and rays). Fin spine growth is of great interest and relevance but few studies have considered their evolution and development. We investigated the development of the fin spine of the chimaerid Callorhinchus milii using stained histological sections from a series of larval, hatchling, and adult individuals. The lamellar trunk dentine of the Callorhinchus spine first condenses within the mesenchyme, rather than at the contact surface between mesenchyme and epithelium, in a manner more comparable to dermal bone formation than to normal odontode development. Trabecular dentine forms a small component of the spine under the keel; it is covered externally with a thin layer of lamellar trunk dentine, which is difficult to distinguish in sectioned adult spines. We suggest that the distinctive characteristics of the trunk dentine may reflect an origin through co-option of developmental processes involved in dermal bone formation. Comparison with extant Squalus and a range of fossil chondrichthyans shows that Callorhinchus is more representative than Squalus of generalized chondrichthyan fin-spine architecture, highlighting its value as a developmental model organism.

  10. Heat Transfer Measurements of Internally Finned Rotating Heat Pipes.

    DTIC Science & Technology

    1983-12-01

    Noncondensable Gases, Rotating Heat Pipe , Performance, Helical and Straight Pin, Internal Heat Transfer Coefficient. AS"RACY (40115111111141 WH ide of* 0686...improvement over the smooth condenser. By helically finning the tube wall in addition to increasing the internal area, the counter-clockwise spiral ... spirally -finned condenser then on the straight-finned condenser. Apparently, during fabrication of the helically -finned condenser, a series of

  11. SKYLAB 4 SATURN IB LAUNCH VEHICLE FIN #6 REPLACEMENT

    NASA Technical Reports Server (NTRS)

    1973-01-01

    SKYLAB 4 SATURN IB LAUNCH VEHICLE FIN #6 REPLACEMENT KSC-373C-0791.03 108-KSC-373C-791.3, P-16627, ARCHIVE-04998 Skylab 4, S1B stage fin replacement, CX. 39B. Preparation for removal of old fin #6 - 2130 hours.

  12. SKYLAB 4 SATURN IB LAUNCH VEHICLE FIN REPLACEMENT

    NASA Technical Reports Server (NTRS)

    1973-01-01

    SKYLAB 4 SATURN IB LAUNCH VEHICLE FIN REPLACEMENT KSC-373C-0791.05 108-KSC-373C-791.5, P-16625, ARCHIVE-04997 Skylab 4, S1B stage fin replacement, CX 39B. Old fin #6 prior to lowering to zero level - 2315 hrs.

  13. Finned Tube With Vortex Generators For A Heat Exchanger.

    DOEpatents

    Sohal, Monohar S.; O'Brien, James E.

    2004-09-14

    A system for and method of manufacturing a finned tube for a heat exchanger is disclosed herein. A continuous fin strip is provided with at least one pair of vortex generators. A tube is rotated and linearly displaced while the continuous fin strip with vortex generators is spirally wrapped around the tube.

  14. Finned Tube With Vortex Generators For A Heat Exchanger.

    DOEpatents

    Sohal, Manohar S.; O'Brien, James E.

    2005-12-20

    A system for and method of manufacturing a finned tube for a heat exchanger is disclosed herein. A continuous fin strip is provided with at one pair of vortex generators. A tube is rotated and linearly displaced while the continuous fin strip with vortex generators is spirally wrapped around the tube.

  15. Dynamic bioaccumulation of organics in finned fish

    SciTech Connect

    Vohra, R.; Cohen, Y.

    1995-12-31

    A compartmental food-chain bioaccumulation model was developed to predict the degree of bioaccumulation of hydrophobic toxins in finned fish under dynamic conditions. The model was developed with the intent of minimizing the number of required user-input parameters while maintaining flexibility of describing a wide range of plausible scenarios. The model is shown to be in excellent agreement with more complex models and with available field data. The effect of various uptake mechanisms, morphometric parameters and species diet on toxin accumulation in finned fish will be illustrated via a number of test cases covering a wide set of species. The integration of the current bioaccumulation model with multimedia chemical transport and fate models such as the recent Integrated Spatial Multimedia Compartmental Model (Cohen and van de Water, in Computer Techniques in Environmental Studies, Vol. 1, Pollution Modeling, Zannetti (Ed.), 1994) will also be described and illustrated via selected test cases.

  16. Sizing-tube-fin space radiators

    NASA Technical Reports Server (NTRS)

    Peoples, J. A.

    1978-01-01

    Temperature and size considerations of the tube fin space radiator were characterized by charts and equations. An approach of accurately assessing rejection capability commensurate with a phase A/B level output is reviewed. A computer program, based on Mackey's equations, is also presented which sizes the rejection area for a given thermal load. The program also handles the flow and thermal considerations of the film coefficient.

  17. Analysis of vortex-induced counter torque and fin pressure on a finned body of revolution.

    SciTech Connect

    Chang, Leyen S.

    2005-09-01

    Finned bodies of revolution firing lateral jets in flight may experience lower spin rates than predicted. This reduction in spin rate is a result of vortices generated by the interaction between the lateral jets and freestream air flowing past the body. The vortices change the pressure distribution on the fins, inducing a counter torque that opposes the desired spin. Wind tunnel data measuring roll torque and fin pressures were collected for a full-scale model at varying angle of attack, roll angle, airspeed, and jet strength. The current analysis builds upon previously written code that computes torque by integrating pressure over the fin surfaces at 0{sup o} angle of attack. The code was modified to investigate the behavior of counter torque at different angles of attack and roll angles as a function of J, the ratio of jet dynamic pressure to freestream dynamic pressure. Numerical error analysis was applied to all data to assist with interpretation of results. Results show that agreement between balance and fin pressure counter torque at 0{sup o} angle of attack was not as close as previously believed. Counter torque at 4{sup o} angle of attack was higher than at 0{sup o}, and agreement between balance and fin pressure counter torque was closer. Plots of differential fin pressure coefficient revealed a region of high pressure at the leading edge and an area of low pressure over the center and aft regions of the tapped surface. Large differences in the counter-torque coefficient were found between various freestream dynamic pressures, especially at Mach 0.95 and 1.1. Roll angle had significant effect only for cases at angle of attack, where it caused counter torque to change unpredictably.

  18. Fluid dynamics of the larval zebrafish pectoral fin and the role of fin bending in fluid transport.

    PubMed

    Green, Matthew H; Curet, Oscar M; Patankar, Neelesh A; Hale, Melina E

    2013-03-01

    Larval zebrafish beat their pectoral fins during many behaviors including low-speed swimming and prey tracking; however, little is known about the functions of these fin movements. Previously, we found experimental support for the function of larval fins in mixing of fluid near the body, which may enhance respiration by diffusion of dissolved oxygen across the skin. Here we use computational fluid dynamics to analyze fluid flow due to the pectoral fin movement. The pectoral fins bend along their proximodistal axis during abduction (fin extension), but remain nearly rigid during adduction (fin flexion). We hypothesize that this asymmetry in bending is critical for fluid mixing near the body and test the effects of fin bending with our simulations. For normal fin beats, we observed similar flow patterns in simulations and experiments. Flow patterns showed fluid stretching and folding, indicative of mixing. When proximodistal bending was removed from fin motion, fins were less effective at transporting fluid in a posterior direction near the body surface, but lateral mixing of fluid near the body was unaffected. Our results suggest that fin bending enhances posterior transport of fluid along the body surface, which may act to aid respiration in combination with lateral stretching and folding of fluid.

  19. Asymmetrically doped stacked channel strained SOI FinFET

    NASA Astrophysics Data System (ADS)

    Dubey, Shashank; Kondekar, Pravin N.

    2017-02-01

    Strained SOI (SSOI) n-channel trigate FinFET is designed with asymmetrically doped stacked channels along the fin height. The OFF current is reduced with respect to lightly doped uniform SSOI FinFET because of band gap modification, originated between highly doped uniaxial strained and lightly doped Si fin. Through TCAD simulation it is observed that for the stacked devices the OFF current is reduced by more than 47%. The performances are also compared with highly doped uniform SSOI FinFETs and the results indicated that these devices have lesser random dopant variation at a moderate cost of ON and OFF current.

  20. El medio interestelar alrededor de estrellas Of

    NASA Astrophysics Data System (ADS)

    Caballero, N.; Cappa, C.

    Se analiza la distribución del hidrógeno neutro interestelar en la vecindad de algunas estrellas Of con el fin de investigar la presencia de burbujas de H I vinculadas a las estrellas. Se determinan los parámetros físicos de las burbujas de H I encontradas y se comparan con estructuras similares vinculadas a estrellas Wolf-Rayet. El estudio se lleva a cabo en base a datos pertenecientes al relevamiento de Weaver y Willians (1973).

  1. Studying Fin Whales with Seafloor Seismic Networks

    NASA Astrophysics Data System (ADS)

    Wilcock, W. S.; Soule, D. C.; Weirathmueller, M.; Thomson, R.

    2011-12-01

    Baleen whales are found throughout the world's oceans and their welfare captivates the general public. Depending on the species, baleen whales vocalize at frequencies ranging from ~10 Hz to several kilohertz. Passive acoustic studies of whale calls are used to investigate behavior and habitat usage, monitor the recovery of populations from whaling and assess the impacts of anthropogenic sounds. Since airguns are a significant source of sound in the oceans, the research goals of academic seismologists can lead to conflicts with those who advocate for whale conservation while being unwilling to consider the societal benefits of marine geophysical studies. In contrast, studies that monitor earthquakes with ocean bottom seismometers (OBSs) provide an opportunity to enhance studies of baleen whales and improve relationships with environmental advocates. The bandwidth of the typical high-frequency or intermediate-band ocean bottom seismometer overlaps the call frequency of the two largest baleen whale species; blue whales generate sequences of 10- to 20-s-long calls centered at ~16 Hz and fin whales produce long sequences of downswept 1-s-long chirps centered at ~20 Hz. Several studies have demonstrated the potential of OBS networks to monitor calling patterns and determine tracks for fin and blue whales. We will summarize the results from a study to track fin whales near the Endeavour hydrothermal vent fields on the Juan de Fuca Ridge and investigate a potential correlation between the density of whales and enhanced zooplankton found throughout the water column overlying the vent fields. From 2003-2006 an 8-station local seismic network that was designed to monitor hydrothermal earthquakes also recorded ~300,000 fin whale vocalizations, mostly in the fall and winter. Automatic picking and localization techniques that are analogous to those used to analyze earthquakes are employed to determine whale tracks. The tracks are then used to interpret calling patterns in the

  2. Heat Dissipation from a Finned Cylinder at Different Fin-Plane/Air-stream Angles

    NASA Technical Reports Server (NTRS)

    Schey, Oscar W; Biermann, Arnold E

    1932-01-01

    This report gives the results of an experimental determination of the temperature distribution in and the heat dissipation from a cylindrical finned surface for various fin-plane/air-stream angles. A steel cylinder 4.5 inches in diameter having slightly tapered fins of 0.30-inch pitch and 0.6 -inch width was equipped with an electrical heating unit furnishing 13 to 248 B.T.U. per hour per square inch of inside wall area. Air at speeds form 30 to 150 miles per hour was directed at seven different angles from 0 degrees to 90 degrees with respect to the fin planes. The tests show the best angle for cooling at all air speeds to be about 45 degrees. With the same temperature for the two conditions and with an air speed of 76 miles per hour, the heat input to the cylinder can be increased 50 percent at 45 degrees fin-plane/air-stream angle over that at 0 degrees.

  3. Material and fin pitch effect on frosting CO2 in a fin-and-tube heat exchanger

    NASA Astrophysics Data System (ADS)

    Bassila, Joseph; Toubassy, Joseph; Danlos, Amélie; Descombes, Georges; Clodic, Denis

    2017-02-01

    Cryo Pur technology uses cryogenic separation to remove water vapor and carbon dioxide from biogas, in order to obtain bio-methane. To cool down the biogas at a very low temperature, a fin-and-tube heat exchanger is designed. In order to improve the fin-and-tube heat exchanger performance, a model is developed to investigate the material and fin pitch on frosting carbon dioxide. This paper will study the effect of the tubes and the fins material, and the fin pitch effect. The purpose is to extend the duration of a frosting cycle.

  4. Use of biorobotic models of highly deformable fins for studying the mechanics and control of fin forces in fishes.

    PubMed

    Tangorra, James; Phelan, Chris; Esposito, Chris; Lauder, George

    2011-07-01

    Bony fish swim with a level of agility that is unmatched in human-developed systems. This is due, in part, to the ability of the fish to carefully control hydrodynamic forces through the active modulation of the fins' kinematics and mechanical properties. To better understand how fish produce and control forces, biorobotic models of the bluegill sunfish's (Lepomis macrochirus) caudal fin and pectoral fins were developed. The designs of these systems were based on detailed analyses of the anatomy, kinematics, and hydrodynamics of the biological fins. The fin models have been used to investigate how fin kinematics and the mechanical properties of the fin-rays influence propulsive forces and to explore kinematic patterns that were inspired by biological motions but that were not explicitly performed by the fish. Results from studies conducted with the fin models indicate that subtle changes to the kinematics and mechanical properties of fin rays can significantly impact the magnitude, direction, and time course of the 3D forces used for propulsion and maneuvers. The magnitude of the force tends to scale with the fin's stiffness, but the direction of the force is not invariant, and this causes disproportional changes in the magnitude of the thrust, lift, and lateral components of force. Results from these studies shed light on the multiple strategies that are available to the fish to modulate fin forces.

  5. Students Informing Now (S.I.N.) Challenge the Racial State in California without Shame..."SIN Verguenza!"

    ERIC Educational Resources Information Center

    Educational Foundations, 2007

    2007-01-01

    On a cold and wet Friday night in January of 2006, thirteen undergraduate students gathered together in a small room on campus at the University of California, Santa Cruz (UCSC) to found Students Informing Now (S.I.N.). S.I.N. was created to support the AB 504 students, labeled in this country as "illegal aliens." Inspired by Paulo…

  6. Proteomic analysis of zebrafish caudal fin regeneration.

    PubMed

    Saxena, Sandeep; Singh, Sachin K; Lakshmi, Mula G Meena; Meghah, Vuppalapaty; Bhatti, Bhawna; Swamy, Cherukuvada V Brahmendra; Sundaram, Curam S; Idris, Mohammed M

    2012-06-01

    The epimorphic regeneration of zebrafish caudal fin is rapid and complete. We have analyzed the biomechanism of zebrafish caudal fin regeneration at various time points based on differential proteomics approaches. The spectrum of proteome changes caused by regeneration were analyzed among controls (0 h) and 1, 12, 24, 48, and 72 h postamputation involving quantitative differential proteomics analysis based on two-dimensional gel electrophoresis matrix-assisted laser desorption/ionization and differential in-gel electrophoresis Orbitrap analysis. A total of 96 proteins were found differentially regulated between the control nonregenerating and regenerating tissues of different time points for having at least 1.5-fold changes. 90 proteins were identified as differentially regulated for regeneration based on differential in-gel electrophoresis analysis between the control and regenerating tissues. 35 proteins were characterized for its expression in all of the five regenerating time points against the control samples. The proteins identified and associated with regeneration were found to be directly allied with various molecular, biological, and cellular functions. Based on network pathway analysis, the identified proteome data set for regeneration was majorly associated in maintaining cellular structure and architecture. Also the proteins were found associated for the cytoskeleton remodeling pathway and cellular immune defense mechanism. The major proteins that were found differentially regulated during zebrafish caudal fin regeneration includes keratin and its 10 isoforms, cofilin 2, annexin a1, skeletal α1 actin, and structural proteins. Annexin A1 was found to be exclusively undergoing phosphorylation during regeneration. The obtained differential proteome and the direct association of the various proteins might lead to a new understanding of the regeneration mechanism.

  7. Molecular mechanisms underlying the exceptional adaptations of batoid fins

    PubMed Central

    Nakamura, Tetsuya; Klomp, Jeff; Pieretti, Joyce; Schneider, Igor; Gehrke, Andrew R.; Shubin, Neil H.

    2015-01-01

    Extreme novelties in the shape and size of paired fins are exemplified by extinct and extant cartilaginous and bony fishes. Pectoral fins of skates and rays, such as the little skate (Batoid, Leucoraja erinacea), show a strikingly unique morphology where the pectoral fin extends anteriorly to ultimately fuse with the head. This results in a morphology that essentially surrounds the body and is associated with the evolution of novel swimming mechanisms in the group. In an approach that extends from RNA sequencing to in situ hybridization to functional assays, we show that anterior and posterior portions of the pectoral fin have different genetic underpinnings: canonical genes of appendage development control posterior fin development via an apical ectodermal ridge (AER), whereas an alternative Homeobox (Hox)–Fibroblast growth factor (Fgf)–Wingless type MMTV integration site family (Wnt) genetic module in the anterior region creates an AER-like structure that drives anterior fin expansion. Finally, we show that GLI family zinc finger 3 (Gli3), which is an anterior repressor of tetrapod digits, is expressed in the posterior half of the pectoral fin of skate, shark, and zebrafish but in the anterior side of the pelvic fin. Taken together, these data point to both highly derived and deeply ancestral patterns of gene expression in skate pectoral fins, shedding light on the molecular mechanisms behind the evolution of novel fin morphologies. PMID:26644578

  8. Undulating fins produce off-axis thrust and flow structures.

    PubMed

    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.

  9. Touch sensation by pectoral fins of the catfish Pimelodus pictus

    PubMed Central

    Hardy, Adam R.; Steinworth, Bailey M.

    2016-01-01

    Mechanosensation is fundamental to many tetrapod limb functions, yet it remains largely uninvestigated in the paired fins of fishes, limb homologues. Here we examine whether membranous fins may function as passive structures for touch sensation. We investigate the pectoral fins of the pictus catfish (Pimelodus pictus), a species that lives in close association with the benthic substrate and whose fins are positioned near its ventral margin. Kinematic analysis shows that the pectoral fins are held partially protracted during routine forward swimming and do not appear to generate propulsive force. Immunohistochemistry reveals that the fins are highly innervated, and we observe putative mechanoreceptors at nerve fibre endings. To test for the ability to sense mechanical perturbations, activity of fin ray nerve fibres was recorded in response to touch and bend stimulation. Both pressure and light surface brushing generated afferent nerve activity. Fin ray nerves also respond to bending of the rays. These data demonstrate for the first time that membranous fins can function as passive mechanosensors. We suggest that touch-sensitive fins may be widespread in fishes that maintain a close association with the bottom substrate. PMID:26865307

  10. Fin Line Filters Technology and Electronic Warfare.

    DTIC Science & Technology

    1984-12-01

    UNCLASSIFIED SSECURITY CLASSIFICATION OF THIS PAGEt n Date Enteed) 6: t . Approved for public release; distribution unlimited. Fin Line Filters...Form of the Black Box Element 26 3.1 Filter #1, Four Strips 30 3.2 Filter #2, Seven Strips 30 3.3 Filters #3, #4, Two Strips -- 31 3.4 Filter #5 (Z...1.40 cm) Two Strips, with Dielectric 31 3.5 Filters #6, #7, Two Strips ---------------------- 32 3.6 e11 vs. Frequency for a T = 0.2 Inch Inductive Strip

  11. Development and Validation of the Single Item Narcissism Scale (SINS)

    PubMed Central

    Konrath, Sara; Meier, Brian P.; Bushman, Brad J.

    2014-01-01

    Main Objectives The narcissistic personality is characterized by grandiosity, entitlement, and low empathy. This paper describes the development and validation of the Single Item Narcissism Scale (SINS). Although the use of longer instruments is superior in most circumstances, we recommend the SINS in some circumstances (e.g. under serious time constraints, online studies). Methods In 11 independent studies (total N = 2,250), we demonstrate the SINS' psychometric properties. Results The SINS is significantly correlated with longer narcissism scales, but uncorrelated with self-esteem. It also has high test-retest reliability. We validate the SINS in a variety of samples (e.g., undergraduates, nationally representative adults), intrapersonal correlates (e.g., positive affect, depression), and interpersonal correlates (e.g., aggression, relationship quality, prosocial behavior). The SINS taps into the more fragile and less desirable components of narcissism. Significance The SINS can be a useful tool for researchers, especially when it is important to measure narcissism with constraints preventing the use of longer measures. PMID:25093508

  12. Anatomy and early development of the pectoral girdle, fin, and fin spine of sturgeons (Actinopterygii: Acipenseridae).

    PubMed

    Dillman, Casey B; Hilton, Eric J

    2015-03-01

    Acipenseriformes hold an important place in the evolutionary history of bony fishes. Given their phylogenetic position as extant basal Actinopterygii, it is generally held that a thorough understanding of their morphology will greatly contribute to the knowledge of the evolutionary history and the origin of diversity for the major osteichthyan clades. To this end, we examined comparative developmental series from the pectoral girdle in Acipenser fulvescens, A. medirostris, A. transmontanus, and Scaphirhynchus albus to document, describe, and compare ontogenetic and allometric differences in the pectoral girdle. We find, not surprisingly, broad congruence between taxa in the basic pattern of development of the dermal and chondral elements of the pectoral girdle. However, we also find clear differences in the details of structure and development among the species examined in the dermal elements, including the clavicle, cleithrum, supracleithrum, posttemporal, and pectoral-fin spine. We also find differences in the internal fin elements such as the distal radials as well as in the number of fin rays and their association with the propterygium. Further, there are clear ontogenetic differences during development of the dermal and chondral elements in these species and allometric variation in the pectoral-fin spine. The characters highlighted provide a suite of elements for further examination in studies of the phylogeny of sturgeons. Determining the distribution of these characters in other sturgeons may aid in further resolution of phylogenetic relationships, and these data highlight the role that ontogenetic and comparative developmental studies provide in systematics.

  13. The making of differences between fins and limbs

    PubMed Central

    Yano, Tohru; Tamura, Koji

    2013-01-01

    ‘Evo-devo’, an interdisciplinary field based on developmental biology, includes studies on the evolutionary processes leading to organ morphologies and functions. One fascinating theme in evo-devo is how fish fins evolved into tetrapod limbs. Studies by many scientists, including geneticists, mathematical biologists, and paleontologists, have led to the idea that fins and limbs are homologous organs; now it is the job of developmental biologists to integrate these data into a reliable scenario for the mechanism of fin-to-limb evolution. Here, we describe the fin-to-limb transition based on key recent developmental studies from various research fields that describe mechanisms that may underlie the development of fins, limb-like fins, and limbs. PMID:23256837

  14. Pelvic fins in teleosts: structure, function and evolution.

    PubMed

    Yamanoue, Y; Setiamarga, D H E; Matsuura, K

    2010-10-01

    The pelvic fins of teleosts are paired appendages that are considered to be homologous to the hind limbs of tetrapods. Because they are less important for swimming, their morphology and function can be flexibly modified, and such modifications have probably facilitated the adaptations of teleosts to various environments. Recently, among these modifications, pelvic-fin loss has gained attention in evolutionary developmental biology. Pelvic-fin loss, however, has only been investigated in a few model species, and various biological aspects of pelvic fins in teleosts in general remain poorly understood. This review summarizes the current state of knowledge regarding pelvic fins, such as their structure, function and evolution, to elucidate their contribution to the considerable diversity of teleosts. This information could be invaluable for future investigations into various aspects of pelvic fins, which will provide clues to understanding the evolution, diversity and adaptations of teleosts.

  15. fgf20 is essential for initiating zebrafish fin regeneration.

    PubMed

    Whitehead, Geoffrey G; Makino, Shinji; Lien, Ching-Ling; Keating, Mark T

    2005-12-23

    Epimorphic regeneration requires the presence or creation of pluripotent cells capable of reproducing lost organs. Zebrafish fin regeneration is mediated by the creation of blastema cells. Here, we characterize the devoid of blastema (dob) mutant that fails fin regeneration during initial steps, forms abnormal regeneration epithelium, and does not form blastema. This mutation has no impact on embryonic survival. Dob results from an fgf20a null mutation, Y148S. Fgf20a is expressed during initiation of fin regeneration at the epithelial-mesenchymal boundary and later overlaps with the blastema marker msxb. Thus, fgf20a has a regeneration-specific requirement, initiating fin regeneration, and controlling blastema formation.

  16. Grid Fin Stabilization of the Orion Launch Abort Vehicle

    NASA Technical Reports Server (NTRS)

    Pruzan, Daniel A.; Mendenhall, Michael R.; Rose, William C.; Schuster, David M.

    2011-01-01

    Wind tunnel tests were conducted by Nielsen Engineering & Research (NEAR) and Rose Engineering & Research (REAR) in conjunction with the NASA Engineering & Safety Center (NESC) on a 6%-scale model of the Orion launch abort vehicle (LAV) configured with four grid fins mounted near the base of the vehicle. The objectives of these tests were to 1) quantify LAV stability augmentation provided by the grid fins from subsonic through supersonic Mach numbers, 2) assess the benefits of swept grid fins versus unswept grid fins on the LAV, 3) determine the effects of the LAV abort motors on grid fin aerodynamics, and 4) generate an aerodynamic database for use in the future application of grid fins to small length-to-diameter ratio vehicles similar to the LAV. The tests were conducted in NASA Ames Research Center's 11x11-foot transonic wind tunnel from Mach 0.5 through Mach 1.3 and in their 9x7-foot supersonic wind tunnel from Mach 1.6 through Mach 2.5. Force- and moment-coefficient data were collected for the complete vehicle and for each individual grid fin as a function of angle of attack and sideslip angle. Tests were conducted with both swept and unswept grid fins with the simulated abort motors (cold jets) off and on. The swept grid fins were designed with a 22.5deg aft sweep angle for both the frame and the internal lattice so that the frontal projection of the swept fins was the same as for the unswept fins. Data from these tests indicate that both unswept and swept grid fins provide significant improvements in pitch stability as compared to the baseline vehicle over the Mach number range investigated. The swept fins typically provide improved stability as compared to the unswept fins, but the performance gap diminished as Mach number was increased. The aerodynamic performance of the fins was not observed to degrade when the abort motors were turned on. Results from these tests indicate that grid fins can be a robust solution for stabilizing the Orion LAV over a wide

  17. Impacts of plasma-induced damage due to UV light irradiation during etching on Ge fin fabrication and device performance of Ge fin field-effect transistors

    NASA Astrophysics Data System (ADS)

    Mizubayashi, Wataru; Noda, Shuichi; Ishikawa, Yuki; Nishi, Takashi; Kikuchi, Akio; Ota, Hiroyuki; Su, Ping-Hsun; Li, Yiming; Samukawa, Seiji; Endo, Kazuhiko

    2017-02-01

    We investigated the impacts of plasma-induced damage due to UV light irradiation during etching on Ge fin fabrication and the device performance of Ge fin field-effect transistors (Ge FinFETs). UV light irradiation during etching affected the shape of the Ge fin and the surface roughness of the Ge fin sidewall. A vertical and smooth Ge fin could be fabricated by neutral beam etching without UV light irradiation. The performances of Ge FinFETs fabricated by neutral beam etching were markedly improved as compared to those of Ge FinFETs fabricated by inductively coupled plasma etching, in which the UV light has an impact.

  18. First discovery of a primitive coelacanth fin fills a major gap in the evolution of lobed fins and limbs.

    PubMed

    Friedman, Matt; Coates, Michael I; Anderson, Philip

    2007-01-01

    The fossil record provides unique clues about the primitive pattern of lobed fins, the precursors of digit-bearing limbs. Such information is vital for understanding the evolutionary transition from fish fins to tetrapod limbs, and it guides the choice of model systems for investigating the developmental changes underpinning this event. However, the evolutionary preconditions for tetrapod limbs remain unclear. This uncertainty arises from an outstanding gap in our knowledge of early lobed fins: there are no fossil data that record primitive pectoral fin conditions in coelacanths, one of the three major groups of sarcopterygian (lobe-finned) fishes. A new fossil from the Middle-Late Devonian of Wyoming preserves the first and only example of a primitive coelacanth pectoral fin endoskeleton. The strongly asymmetrical skeleton of this fin corroborates the hypothesis that this is the primitive sarcopterygian pattern, and that this pattern persisted in the closest fish-like relatives of land vertebrates. The new material reveals the specializations of paired fins in the modern coelacanth, as well as in living lungfishes. Consequently, the context in which these might be used to investigate evolutionary and developmental relationships between vertebrate fins and limbs is changed. Our data suggest that primitive actinopterygians, rather than living sarcopterygian fishes and their derived appendages, are the most informative comparators for developmental studies seeking to understand the origin of tetrapod limbs.

  19. Development of a bio-inspired transformable robotic fin.

    PubMed

    Yang, Yikun; Xia, Yu; Qin, Fenghua; Xu, Min; Li, Weihua; Zhang, Shiwu

    2016-08-31

    Fish swim by oscillating their pectoral fins forwards and backwards in a cyclic motion such that their geometric parameters and aspect ratios change according to how fast or slow a fish wants to swim; these complex motions result in a complicated hydrodynamic response. This paper focuses on the dynamic change in the shape of a fin to improve the underwater propulsion of bio-inspired mechanism. To do this, a novel transformable robotic fin has been developed to investigate how this change in shape affects the hydrodynamic forces acting on the fin. This robotic fin has a multi-link frame and a flexible surface skin where changes in shape are activated by a purpose designed multi-link mechanism driven by a transformation motor. A drag platform has been designed to study the performance of this variable robotic fin. Numerous experiments were carried out to determine how various controlling modes affect the thrust capability of this fin. The kinematic parameters associated with this robotic fin include the oscillating frequency and amplitude, and the drag velocity. The fin has four modes to control the cyclic motion; these were also investigated in combination with the variable kinematic parameters. The results will help us understand the locomotion performance of this transformable robotic fin. Note that different controlling modes influence the propulsive performance of this robotic fin, which means its propulsive performance can be optimized in a changing environment by adapting its shape. This study facilitates the development of bio-inspired unmanned underwater vehicles with a very high swimming performance.

  20. Osteogenic programs during zebrafish fin regeneration

    PubMed Central

    Watson, Claire J; Kwon, Ronald Y

    2015-01-01

    Recent advances in genomic, screening and imaging technologies have provided new opportunities to examine the molecular and cellular landscape underlying human physiology and disease. In the context of skeletal research, technologies for systems genetics, high-throughput screening and high-content imaging can aid an unbiased approach when searching for new biological, pathological or therapeutic pathways. However, these approaches necessitate the use of specialized model systems that rapidly produce a phenotype, are easy to manipulate, and amenable to optical study, all while representing mammalian bone physiologies at the molecular and cellular levels. The emerging use of zebrafish (Danio rerio) for modeling human disease highlights its potential to accelerate therapeutic and pathway discovery in the mammalian skeleton. In this review, we consider the potential value of zebrafish fin ray regeneration (a rapid, genetically tractable and optically transparent model of intramembranous ossification) as a translational model for such studies. PMID:26421148

  1. Defective fin regeneration in medaka fish (Oryzias latipes) with hypothyroidism.

    PubMed

    Sekimizu, Koshin; Tagawa, Masatomo; Takeda, Hiroyuki

    2007-07-01

    Wild-type medaka are known to have remarkable capabilities of fin, or epimorphic, regeneration. However, a hypothyroid mutant, kamaitachi (kmi), frequently suffers from injury in fins, suggesting an important role of thyroid hormone in fin regeneration. This led us to examine the relationship between thyroid hormone and fin regeneration using medaka as a model. For this, we first set up a medaka experimental system in which the rate of regeneration was statistically analyzed after caudal fin amputation under normal and hypothyroid conditions. As expected, the regeneration of amputated caudal fins was delayed in hypothyroid kmi -/- mutants. We then examined wild-type medaka with thiourea-induced hypothyroidism to evaluate the requirement of thyroid hormone during epimorphic fin regeneration. The results demonstrate that the growth rate of regenerates was much reduced in severely hypothyroid medaka throughout the regeneration period. This reduction in regenerative rate was recovered by exogenous administration of L-thyroxine. The present study is thus the first to report the direct involvement of thyroid hormone in teleost fin regeneration, and provides a basic framework for future molecular and genetic analyses.

  2. Heat Transfer from Finned Metal Cylinders in an Air Stream

    NASA Technical Reports Server (NTRS)

    Biermann, Arnold, E; Pinkel, Benjamin

    1935-01-01

    This report presents the results of tests made to supply design information for the construction of metal fins for the cooling of heated cylindrical surfaces by an air stream. A method is given for determining fin dimensions for a maximum heat transfer with the expenditure of a given amount of material for a variety of conditions of air flow and metals.

  3. The heat transfer of cooling fins on moving air

    NASA Technical Reports Server (NTRS)

    Doetsch, Hans

    1935-01-01

    The present report is a comparison of the experimentally defined temperature and heat output of cooling fins in the air stream with theory. The agreement is close on the basis of a mean coefficient of heat transfer with respect to the total surface. A relationship is established between the mean coefficient of heat transfer, the dimensions of the fin arrangement, and the air velocity.

  4. Rate of Heat Transfer from Finned Metal Surfaces

    NASA Technical Reports Server (NTRS)

    Taylor, G Fayette; Rehbock, A

    1930-01-01

    The object was to evaluate the factors which control the rate of heat transfer to a moving current of air from finned metal surfaces similar to those used on aircraft engine cylinders. The object was to establish data which will enable the finning of cooling surfaces to be designed to suit the particular needs of any specific application. Most of the work was done on flat copper specimens 6 inches square, upon which were mounted copper fins with spacings varying from 1/2 inch to 1/12 inch. All fins were 1 inch deep, 6 inches long, and .020 inch thick. The results of the investigation are given in the form of curves included here. In general, it was found that for specimens of this kind, the effectiveness of a given fin does not decrease very rapidly until its distance from adjacent fins has been reduced to 1/9 or 1/10 of an inch. A formula for the heat transfer from a flat surface without fins was developed, and an approximate formula for the finned specimens is suggested.

  5. The origin of a new fin skeleton through tinkering.

    PubMed

    Stewart, Thomas A

    2015-07-01

    Adipose fins are positioned between the dorsal and caudal fins of many teleost fishes and primitively lack skeleton. In at least four lineages, adipose fins have evolved lepidotrichia (bony fin rays), co-opting the developmental programme for the dermal skeleton of other fins into this new territory. Here I provide, to my knowledge, the first description of lepidotrichia development in an adipose fin, characterizing the ontogeny of the redtail catfish, Phractocephalus hemioliopterus. Development of these fin rays differs from canonical lepidotrich development in the following four ways: skeleton begins developing in adults, not in larvae; rays begin developing at the fin's distal tip, not proximally; the order in which rays ossify is variable, not fixed; and lepidotrichia appear to grow both proximally and distally, not exclusively proximodistally. Lepidotrichia are often wavy, of irregular thickness and exhibit no regular pattern of segmentation or branching. This skeleton is among the most variable observed in a vertebrate appendage, offering a unique opportunity to explore the basis of hypervariation, which is generally assumed to reflect an absence of function. I argue that this variation reflects a lack of canalization as compared with other, more ancient lepidotrichs and suggest developmental context can affect the morphology of serial homologues.

  6. Replacement fin processing for III-V on Si: From FinFets to nanowires

    NASA Astrophysics Data System (ADS)

    Waldron, Niamh; Merckling, Clement; Teugels, Lieve; Ong, Patrick; Sebaai, Farid; Barla, Kathy; Collaert, Nadine; Thean, Voon-Yew (Aaron)

    2016-01-01

    In this paper we review the details and results of the replacement fin process technique used to successfully demonstrate InGaAs based channel devices from FinFets to ultra scaled nanowires on 300 mm Si substrates. For FinFet devices a Mg p-type doping solution was developed to counteract the unintentional n-type doping of the InP buffer layer which resulted in high source-drain leakage. However, the performance of these devices is found to be limited by the Mg doping as the mobility is degraded. By switching to a GAA architecture the problem of source-leakage through the InP buffer is effectively eliminated and best devices with LG = 60 nm have a peak transconductance of 1030 μS/μm with a SSSAT of 125 mV/dec are achieved. A comparison of gate first to gate last processing highlights the importance of using a low thermal budget process to maintain the integrity of the InGaAs/high-K interface. Nanowires with a diameter of 6 nm were demonstrated to show quantization induced immunity to Dit resulting in a SSSAT as low as 66 mV/dec for 85 nm LG devices.

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

    PubMed

    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.

  8. Spectral Domain Analysis of Fin-Line.

    DTIC Science & Technology

    1979-12-01

    For the matrices [ME] and [M5 ], the elements m 11 through m 6 8 are the same. 92 (k lD) 2sinh [ (- 1D ) (hl/D)l ] D) 2 0 mlll j (kclD) 2sin[ (y ,,D...D ) (SD) cosY2 1D -((inD) (8D) cosy 2 "D m24= 0 93 I -j (wLiD) (y 1 ’D)sint (yj1 D) (h 1 /D) IIj (wu~D) (-Y2 D) coshy2 D m 2 6 = _ ww~D) (y2 "D) co s...71 D) (D e 2+(8D) (wilD)(yD) 2a be __* 2 (Ae) * h - ( D) 2 (e -(Ah) +j(kD) 2(a D) 2 A 21 D D D D h h (D) (wu 1D ) (O nD) 2 Ah [sinh2(y1 D) (--)-2

  9. The human dark side: evolutionary psychology and original sin.

    PubMed

    Lee, Joseph; Theol, M

    2014-04-01

    Human nature has a dark side, something important to religions. Evolutionary psychology has been used to illuminate the human shadow side, although as a discipline it has attracted criticism. This article seeks to examine the evolutionary psychology's understanding of human nature and to propose an unexpected dialog with an enduring account of human evil known as original sin. Two cases are briefly considered: murder and rape. To further the exchange, numerous theoretical and methodological criticisms and replies of evolutionary psychology are explored jointly with original sin. Evolutionary psychology can partner with original sin since they share some theoretical likenesses and together they offer insights into the nature of what it means to be human.

  10. Sin, suffering, and the need for the theological virtues.

    PubMed

    Jones, David Albert

    2006-08-01

    This article examines the account of the relationship between sin and suffering provided by J. L. A. Garcia in "Sin and Suffering in a Catholic Understanding of Medical Ethics," in this issue. Garcia draws on the (Roman) Catholic tradition and particularly on the thought of Thomas Aquinas, who remains an important resource for Catholic theology. Nevertheless, his interpretation of Thomas is open to criticism, both in terms of omissions and in terms of positive claims. Garcia includes those elements of Thomas that are purely philosophical, such as natural law and acquired virtue, but neglects the theological and infused virtues, the gifts and fruits of the Holy Spirit, and the beatitudes. These omissions distort his account of the Christian life so that he underplays both the radical problem posed by sin (and suffering), and the radical character of the ultimate solution: redemption in Christ through the grace of the Holy Spirit.

  11. [Serotonin dysfunctions in the background of the seven deadly sins].

    PubMed

    Janka, Zoltán

    2003-11-20

    The symbolic characters of the Seven Deadly Sins can be traced from time to time in the cultural history of human mankind, being directly specified in certain artistic products. Such are, among others, the painting entitled "The Seven Deadly Sins and the Four Lost Things" by Hieronymus Bosch and the poems Divina Commedia and The Foerie Queene by Dante Alighieri and Edmund Spenser, respectively. However, there are several paragraphs referring to these behaviours of the Seven Deadly Sins in the Bible and in the dramas of William Shakespeare. The objective of the present review is to propose that dysfunctions in the central serotonergic system might be involved in the neurobiology of these 'sinful' behaviour patterns. Evidences indicate that behaviour traits such as Accidia (Sloth), Luxuria (Lust, Lechery), Superbia (Pride), Ira (Wrath, Anger), Invidia (Envy), Avaritia (Greed, Avarice), and Gula (Gluttony) can relate to the functional alterations of serotonin in the brain. Results of biochemical and molecular genetic (polymorphism) studies on the human serotonergic system (receptor, transporter, enzyme), findings of functional imaging techniques, effects of depletion (or supplementation) of the serotonin precursor tryptophan, data of challenge probe investigations directed to testing central serotonergic functions, alterations in the peripheral serotonin measures (platelet), and the changes in the CSF 5-hydroxy-indoleacetic acid content indicate such serotonergic involvement. Furthermore, results of animal experiments on behaviour change (aggressive, dominant or submissive, appetite, alcohol preference) attributed to serotonin status modification and the clinically evidenced therapeutic efficacy of pharmacological interventions, based on the modulation and perturbation of the serotonergic system (e.g. selective serotonin reuptake inhibitors), in treating the 'sinful' behaviour forms and analogous pathological states reaching the severity of psychiatric disorders

  12. The pectoral fin of Panderichthys and the origin of digits.

    PubMed

    Boisvert, Catherine A; Mark-Kurik, Elga; Ahlberg, Per E

    2008-12-04

    One of the identifying characteristics of tetrapods (limbed vertebrates) is the presence of fingers and toes. Whereas the proximal part of the tetrapod limb skeleton can easily be homologized with the paired fin skeletons of sarcopterygian (lobe-finned) fish, there has been much debate about the origin of digits. Early hypotheses interpreted digits as derivatives of fin radials, but during the 1990s the idea gained acceptance that digits are evolutionary novelties without direct equivalents in fish fin skeletons. This was partly based on developmental genetic data, but also substantially on the pectoral fin skeleton of the elpistostegid (transitional fish/tetrapod) Panderichthys, which appeared to lack distal digit-like radials. Here we present a CT scan study of an undisturbed pectoral fin of Panderichthys demonstrating that the plate-like 'ulnare' of previous reconstructions is an artefact and that distal radials are in fact present. This distal portion is more tetrapod-like than that found in Tiktaalik and, in combination with new data about fin development in basal actinopterygians, sharks and lungfish, makes a strong case for fingers not being a novelty of tetrapods but derived from pre-existing distal radials present in all sarcopterygian fish.

  13. 3D modeling of dual-gate FinFET.

    PubMed

    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.

  14. Studies in Fin-Line Antenna Design for Phased Array Applications.

    DTIC Science & Technology

    1983-11-01

    bend fin-line ........ 2 2. Extended dielectric fin-lime antenna . . . ............ 4 3. Dielectric rod fin-linm antena ..................... S 4...endftire. Mhe latter Is perhaps the most difficult criterion to satisfy. It is easy to visualize a broadside fin-line antena based on a * * periodic...of endfire fin-line antenas , whose designs are shown in fils. 2-5.* In Fig. 2, an antenna is shown in which the dielectric portion of the fin-line wee

  15. Water flow and fin shape polymorphism in coral reef fishes.

    PubMed

    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 (<100 m) along a reef profile (reef slope, crest, and back lagoon). Unlike fin shape, there were no intraspecific differences in 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

  16. The hydrodynamics of ribbon-fin propulsion during impulsive motion.

    PubMed

    Shirgaonkar, Anup A; Curet, Oscar M; Patankar, Neelesh A; Maciver, Malcolm A

    2008-11-01

    Weakly electric fish are extraordinarily maneuverable swimmers, able to swim as easily forward as backward and rapidly switch swim direction, among other maneuvers. The primary propulsor of gymnotid electric fish is an elongated ribbon-like anal fin. To understand the mechanical basis of their maneuverability, we examine the hydrodynamics of a non-translating ribbon fin in stationary water using computational fluid dynamics and digital particle image velocimetry (DPIV) of the flow fields around a robotic ribbon fin. Computed forces are compared with drag measurements from towing a cast of the fish and with thrust estimates for measured swim-direction reversals. We idealize the movement of the fin as a traveling sinusoidal wave, and derive scaling relationships for how thrust varies with the wavelength, frequency, amplitude of the traveling wave and fin height. We compare these scaling relationships with prior theoretical work. The primary mechanism of thrust production is the generation of a streamwise central jet and the associated attached vortex rings. Under certain traveling wave regimes, the ribbon fin also generates a heave force, which pushes the body up in the body-fixed frame. In one such regime, we show that as the number of waves along the fin decreases to approximately two-thirds, the heave force surpasses the surge force. This switch from undulatory parallel thrust to oscillatory normal thrust may be important in understanding how the orientation of median fins may vary with fin length and number of waves along them. Our results will be useful for understanding the neural basis of control in the weakly electric knifefish as well as for engineering bio-inspired vehicles with undulatory thrusters.

  17. Fish locomotion: kinematics and hydrodynamics of flexible foil-like fins

    NASA Astrophysics Data System (ADS)

    Lauder, George V.; Madden, Peter G. A.

    2007-11-01

    The fins of fishes are remarkable propulsive devices that appear at the origin of fishes about 500 million years ago and have been a key feature of fish evolutionary diversification. Most fish species possess both median (midline) dorsal, anal, and caudal fins as well as paired pectoral and pelvic fins. Fish fins are supported by jointed skeletal elements, fin rays, that in turn support a thin collagenous membrane. Muscles at the base of the fin attach to and actuate each fin ray, and fish fins thus generate their own hydrodynamic wake during locomotion, in addition to fluid motion induced by undulation of the body. In bony fishes, the jointed fin rays can be actively deformed and the fin surface can thus actively resist hydrodynamic loading. Fish fins are highly flexible, exhibit considerable deformation during locomotion, and can interact hydrodynamically during both propulsion and maneuvering. For example, the dorsal and anal fins shed a vortex wake that greatly modifies the flow environment experienced by the tail fin. New experimental kinematic and hydrodynamic data are presented for pectoral fin function in bluegill sunfish. The highly flexible sunfish pectoral fin moves in a complex manner with two leading edges, a spanwise wave of bending, and substantial changes in area through the fin beat cycle. Data from scanning particle image velocimetry (PIV) and time-resolved stereo PIV show that the pectoral fin generates thrust throughout the fin beat cycle, and that there is no time of net drag. Continuous thrust production is due to fin flexibility which enables some part of the fin to generate thrust at all times and to smooth out oscillations that might arise at the transition from outstroke to instroke during the movement cycle. Computational fluid dynamic analyses of sunfish pectoral fin function corroborate this conclusion. Future research on fish fin function will benefit considerably from close integration with studies of robotic model fins.

  18. Virtues of SIN: Can Intensified Public Efforts Help Disadvantaged Immigrants?

    ERIC Educational Resources Information Center

    Aslund, Olof; Johansson, Per

    2011-01-01

    The labor market integration of immigrants is a top political priority throughout the Organization for Economic Cooperation and Development (OECD) countries. Social and fiscal gains, as well as sustained future labor supply make governments search for effective policies to increase employment among the mostly disadvantaged. The author studies SIN,…

  19. Hydrodynamic properties of fin whale flippers predict maximum rolling performance.

    PubMed

    Segre, Paolo S; Cade, David E; Fish, Frank E; Potvin, Jean; Allen, Ann N; Calambokidis, John; Friedlaender, Ari S; Goldbogen, Jeremy A

    2016-11-01

    Maneuverability is one of the most important and least understood aspects of animal locomotion. The hydrofoil-like flippers of cetaceans are thought to function as control surfaces that effect maneuvers, but quantitative tests of this hypothesis have been lacking. Here, we constructed a simple hydrodynamic model to predict the longitudinal-axis roll performance of fin whales, and we tested its predictions against kinematic data recorded by on-board movement sensors from 27 free-swimming fin whales. We found that for a given swimming speed and roll excursion, the roll velocity of fin whales calculated from our field data agrees well with that predicted by our hydrodynamic model. Although fluke and body torsion may further influence performance, our results indicate that lift generated by the flippers is sufficient to drive most of the longitudinal-axis rolls used by fin whales for feeding and maneuvering.

  20. Hydrodynamical analysis of the effect of fish fins morphology

    NASA Astrophysics Data System (ADS)

    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.

  1. The X-38 V-201 Fin Fold Actuation Mechanism

    NASA Technical Reports Server (NTRS)

    Lupo, Christian; Robertson, Brandan; Gafka, George

    2004-01-01

    The X-38 Vehicle 201 (V-201) is a space flight prototype lifting body vehicle that was designed to launch to orbit in the Space Shuttle orbiter payload bay. Although the project was cancelled in May 2003, many of the systems were nearly complete. This paper will describe the fin folding actuation mechanism flight subsystems and development units as well as lessons learned in the design, assembly, development testing, and qualification testing. The two vertical tail fins must be stowed (folded inboard) to allow the orbiter payload bay doors to close. The fin folding actuation mechanism is a remotely or extravehicular activity (EVA) actuated single fault tolerant system consisting of seven subsystems capable of repeatedly deploying or stowing the fins.

  2. Plates of the dinosaur stegosaurus: forced convection heat loss fins?

    PubMed

    Farlow, J O; Thompson, C V; Rosner, D E

    1976-06-11

    It is suggested that the plates along the arched back and tail of Stegosaurus served an important thermoregulatory function as forced convection "fins." Wind tunnel experiments on finned models, internal heat conduction calculations, and direct observations of the morphology and internal structure of stegosaur plates support this hypothesis, demonstrating the comparative effectiveness of the plates as heat dissipaters, controllable through input blood flow rate, temperature, and body orientation (with respect to wind).

  3. Wind Fins: Novel Lower-Cost Wind Power System

    SciTech Connect

    David C. Morris; Dr. Will D. Swearingen

    2007-10-08

    This project evaluated the technical feasibility of converting energy from the wind with a novel “wind fin” approach. This patent-pending technology has three major components: (1) a mast, (2) a vertical, hinged wind structure or fin, and (3) a power takeoff system. The wing structure responds to the wind with an oscillating motion, generating power. The overall project goal was to determine the basic technical feasibility of the wind fin technology. Specific objectives were the following: (1) to determine the wind energy-conversion performance of the wind fin and the degree to which its performance could be enhanced through basic design improvements; (2) to determine how best to design the wind fin system to survive extreme winds; (3) to determine the cost-effectiveness of the best wind fin designs compared to state-of-the-art wind turbines; and (4) to develop conclusions about the overall technical feasibility of the wind fin system. Project work involved extensive computer modeling, wind-tunnel testing with small models, and testing of bench-scale models in a wind tunnel and outdoors in the wind. This project determined that the wind fin approach is technically feasible and likely to be commercially viable. Project results suggest that this new technology has the potential to harvest wind energy at approximately half the system cost of wind turbines in the 10kW range. Overall, the project demonstrated that the wind fin technology has the potential to increase the economic viability of small wind-power generation. In addition, it has the potential to eliminate lethality to birds and bats, overcome public objections to the aesthetics of wind-power machines, and significantly expand wind-power’s contribution to the national energy supply.

  4. Labriform swimming of a ray-strengthened pectoral fin

    NASA Astrophysics Data System (ADS)

    Shoele, Kourosh; Zhu, Qiang

    2009-11-01

    Labriform swimming is a common locomotion mode used by fish in low speed swimming, in which thrust generation is achieved through a combination of flapping and rowing motions of pectoral fins. Pectoral fins of bony fishes usually consist of a soft collagen membrane strengthened by embedded flexible rays. Morphologically, each ray is connected to a group of muscles so that the fish can control the rotational motion of each ray individually, enabling multi-degree of freedom control over the fin motion and deformation. We have developed a fluid-structure interaction model to simulate the kinematics and dynamic performance of a structurally idealized fin. This method includes a boundary-element model of the fluid motion and a fully-nonlinear Euler-Bernoulli beam model of the embedded rays. Using this model we studied thrust generation and propulsion efficiency of the fin at different combinations of parameters. Effects of kinematic as well as structural properties are examined. It has been illustrated that the fish's capacity to control the motion of each individual ray, as well as the anisotropic deformability of the fin determined by distribution of the rays, are essential to high propulsion performance. Specifically, it is found that a reinforced ray at the leading edge leads to performance enhancement.

  5. Slotting Fins of Heat Exchangers to Provide Thermal Breaks

    NASA Technical Reports Server (NTRS)

    Scull, Timothy D.

    2003-01-01

    Heat exchangers that include slotted fins (in contradistinction to continuous fins) have been invented. The slotting of the fins provides thermal breaks that reduce thermal conduction along flow paths (longitudinal thermal conduction), which reduces heat-transfer efficiency. By increasing the ratio between transverse thermal conduction (the desired heat-transfer conduction) and longitudinal thermal conduction, slotting of the fins can be exploited to (1) increase heat-transfer efficiency (thereby reducing operating cost) for a given heat-exchanger length or to (2) reduce the length (thereby reducing the weight and/or cost) of the heat exchanger needed to obtain a given heat transfer efficiency. By reducing the length of a heat exchanger, one can reduce the pressure drop associated with the flow through it. In a case in which slotting enables the use of fins with thermal conductivity greater than could otherwise be tolerated on the basis of longitudinal thermal conduction, one can exploit the conductivity to make the fins longer (in the transverse direction) than they otherwise could be, thereby making it possible to make a heat exchanger that contains fewer channels and therefore, that weighs less, contains fewer potential leak paths, and can be constructed from fewer parts and, hence, reduced cost.

  6. Fin propulsion on a human-powered submarine

    NASA Astrophysics Data System (ADS)

    Anderson, Iain A.; Pocock, Benjamin; Harbuz, Antoni; Algie, Cam; Vochezer, Daniel; Chao, Ryan; Lu, Benjamin

    2015-03-01

    Nearly all surface and underwater vessels are driven by screw propulsion; ideal for coupling to rotary engines and well understood after over a century of development. But most aquatic creatures use fins for swimming. Although there are sound evolutionary reasons why fish have fins and not propellers, they are nevertheless agile, fast and efficient. Although fish-like robots such as the MIT Robotuna are providing good insight into fin-based swimming there are advantages for using humans in the experimental device. Like an airplane test pilot they can write crash reports. We present preliminary observations for the human powered finned submarine: Taniwha. The sub participated in the 2nd European International Submarine races in Gosport UK where it received a trophy for "Best Non-Propeller Performance". Two sets of Hobie Mirage fin drives fixed to the upper and lower rear surfaces of the sub are pedaled by the pilot. The pilot also has two levers at the front, one to pitch a pair of dive planes and one for yawing a large rudder. Good speed, we estimate to be greater than 6 m/s is possible with these fins although we haven't explored their full potential. Straying too near the surface or bottom can lead to an instability, synonymous to a stall, such that control is lost. The mechanism for this will be discussed and solutions offered. Fish are 400 million years in front of us but one day we'll catch them.

  7. Condensation of R-134a vapor over single horizontal circular integral-fin tubes with trapezoidal fins

    SciTech Connect

    Kumar, R.; Varma, H.K.; Mohanty, B.; Agrawal, K.N.

    2000-04-01

    An experimental investigation has been carried out for the condensation of R-134a vapor on four single horizontal circular integral-fin tubes (CIFTs) made of copper. The fins are of trapezoidal shape and the fin density of these tubes has been varied systematically from 934 fpm to 1,875 fpm. All the experimental data have been acquired at the saturation temperature of 312.4 {+-} 0.5 K. The CIFT with 1,560 fpm fin density has been found to be the best-performing tube, as it has provided an enhancement factor (EF) of the order of 5.6. The experimental results are in the best agreement with Honda and Nozu model. This model has predicted 80% of the experimental results in a range of 0--30%.

  8. Fin width dependence on gate controllability of InGaAs channel FinFETs with regrown source/drain

    NASA Astrophysics Data System (ADS)

    Kise, Nobukazu; Kinoshita, Haruki; Yukimachi, Atsushi; Kanazawa, Toru; Miyamoto, Yasuyuki

    2016-12-01

    In this paper, we report on the structure and characteristics of an indium gallium arsenide (InGaAs) channel fin field effect transistor (FinFET) with a regrown source/drain. The fabrication process we propose is suitable for forming a channel with a high aspect ratio. In simulations, the subthreshold characteristics and drain current (Id) were improved by reducing the fin width. Following the simulations, fabricated devices showed improved gate controllability after the fin width was reduced. A short-channel device (Lch = 50 nm, Hfin = 50 nm, and Wfin = 20 nm) showed an Id of 367 μA/μm and a minimum subthreshold swing (SSmin) of 211 mV/dec at Vd = 0.5 V. The maximum-to-minimum Id ratio was 105.

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

    NASA Astrophysics Data System (ADS)

    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.

  10. External fins and ejector action for reducing the infrared emission of engine exhaust ducting

    NASA Technical Reports Server (NTRS)

    Vanfossen, G. J., Jr.

    1975-01-01

    An analytical investigation was conducted to determine the feasibility of using external fins and ejector action on the exhaust ducting of a helicopter to reduce the infrared emission of the aircraft. Temperatures were calculated for both circular disk fins and pin fins. Results show that combining ejector action with fins can lower the metal temperature to acceptable levels at least for high flight speeds.

  11. Subgap conductivity in SIN-junctions of high barrier transparency

    NASA Astrophysics Data System (ADS)

    Lotkhov, S. V.; Balashov, D. V.; Khabipov, M. I.; Buchholz, F.-I.; Zorin, A. B.

    2006-11-01

    We investigate the current-voltage characteristics of high-transparency superconductor-insulator-normal metal (SIN) junctions with the specific tunnel resistance ρ ≲ 30 Ω μm2. The junctions were fabricated from different superconducting and normal conducting materials, including Nb, Al, AuPd and Cu. The subgap leakage currents were found to be appreciably larger than those given by the standard tunnelling model. We explain our results using the model of two-electron tunnelling in the coherent diffusive transport regime. We demonstrate that even in the high-transparency SIN-junctions, a noticeable reduction of the subgap current can be achieved by splitting a junction into several submicron sub-junctions. These structures can be used as nonlinear low-noise shunts in rapid-single-flux-quantum (RSFQ) circuitry for controlling Josephson qubits.

  12. Original Antigenic Sin Response to RNA Viruses and Antiviral Immunity

    PubMed Central

    Park, Mee Sook; Kim, Jin Il; Park, Sehee; Lee, Ilseob

    2016-01-01

    The human immune system has evolved to fight against foreign pathogens. It plays a central role in the body's defense mechanism. However, the immune memory geared to fight off a previously recognized pathogen, tends to remember an original form of the pathogen when a variant form subsequently invades. This has been termed 'original antigenic sin'. This adverse immunological effect can alter vaccine effectiveness and sometimes cause enhanced pathogenicity or additional inflammatory responses, according to the type of pathogen and the circumstances of infection. Here we aim to give a simplified conceptual understanding of virus infection and original antigenic sin by comparing and contrasting the two examples of recurring infections such as influenza and dengue viruses in humans. PMID:27799871

  13. Cytoskeletal dynamics of the teleostean fin ray during fin epimorphic regeneration.

    PubMed

    Santos-Ruiz, Leonor; Santamaría, Jesús Alberto; Becerra, José

    2005-04-01

    Teleost fishes can regenerate their fins by epimorphic regeneration, a process that involves the transition of the formerly quiescent tissues of the stump to an active, growing state. This involves dynamic modifications of cell phenotype and behavior that must rely on alterations of the cytoskeleton. We have studied the spatial and temporal distribution of three main components of the cytoskeleton (actin, keratin and vimentin) in the regenerating fin, in order to establish putative relationships between cell cytoskeleton and cell behavior. According to our results, the massive rearrangement undergone by the epidermis right after injury, which takes place by cell migration, correlates with a transient down-regulation of keratin and a strong up-regulation of actin in the epidermal cells. During the subsequent epidermal growth, based on cell proliferation, keratin normal pattern is recovered while actin is down-regulated, although not to normal (quiescent) levels. The epidermal basal layer in contact with the blastema displays a particular cytoskeletal profile, different to that of the rest of the epidermal cells, which reflects its special features. In the connective tissue compartment, somatic cells do not contain vimentin, but keratin, as intermediate filament. Proliferative and migrative activation of these cells after injury correlates with actin up-regulation. Although this initial activation does not involve keratin down-regulation, blastemal cells were later observed to lack keratin, suggesting that such cytoskeletal modification might be needed for connective tissue cells to dedifferentiate and form the blastema. Cell differentiation in the newly formed, regenerated ray is accompanied by actin down-regulation and keratin up-regulation.

  14. A New Analytic Alignment Method for a SINS.

    PubMed

    Tan, Caiming; Zhu, Xinhua; Su, Yan; Wang, Yu; Wu, Zhiqiang; Gu, Dongbing

    2015-11-04

    Analytic alignment is a type of self-alignment for a Strapdown inertial navigation system (SINS) that is based solely on two non-collinear vectors, which are the gravity and rotational velocity vectors of the Earth at a stationary base on the ground. The attitude of the SINS with respect to the Earth can be obtained directly using the TRIAD algorithm given two vector measurements. For a traditional analytic coarse alignment, all six outputs from the inertial measurement unit (IMU) are used to compute the attitude. In this study, a novel analytic alignment method called selective alignment is presented. This method uses only three outputs of the IMU and a few properties from the remaining outputs such as the sign and the approximate value to calculate the attitude. Simulations and experimental results demonstrate the validity of this method, and the precision of yaw is improved using the selective alignment method compared to the traditional analytic coarse alignment method in the vehicle experiment. The selective alignment principle provides an accurate relationship between the outputs and the attitude of the SINS relative to the Earth for a stationary base, and it is an extension of the TRIAD algorithm. The selective alignment approach has potential uses in applications such as self-alignment, fault detection, and self-calibration.

  15. Four-Fin Bio-Inspired UUV: Modeling and Control Solutions

    DTIC Science & Technology

    2011-01-01

    Mechanical Pectoral Fins in the Horizontal Plane ”, Journal of Oceanic Engineering, Transactions of the IEEE, vol. 25, no. 1, 2000. [5] B. Hobson, M... control deformation pectoral fins [7][8][9]. In our previous work, we concluded that active control over the curvature of the robotic pectoral fins ...MODEL The Four- Fin Vehicle Following the development of an actively controlled curvature robotic fin

  16. A robotic fish caudal fin: effects of stiffness and motor program on locomotor performance.

    PubMed

    Esposito, Christopher J; Tangorra, James L; Flammang, Brooke E; Lauder, George V

    2012-01-01

    We designed a robotic fish caudal fin with six individually moveable fin rays based on the tail of the bluegill sunfish, Lepomis macrochirus. Previous fish robotic tail designs have loosely resembled the caudal fin of fishes, but have not incorporated key biomechanical components such as fin rays that can be controlled to generate complex tail conformations and motion programs similar to those seen in the locomotor repertoire of live fishes. We used this robotic caudal fin to test for the effects of fin ray stiffness, frequency and motion program on the generation of thrust and lift forces. Five different sets of fin rays were constructed to be from 150 to 2000 times the stiffness of biological fin rays, appropriately scaled for the robotic caudal fin, which had linear dimensions approximately four times larger than those of adult bluegill sunfish. Five caudal fin motion programs were identified as kinematic features of swimming behaviors in live bluegill sunfish, and were used to program the kinematic repertoire: flat movement of the entire fin, cupping of the fin, W-shaped fin motion, fin undulation and rolling movements. The robotic fin was flapped at frequencies ranging from 0.5 to 2.4 Hz. All fin motions produced force in the thrust direction, and the cupping motion produced the most thrust in almost all cases. Only the undulatory motion produced lift force of similar magnitude to the thrust force. More compliant fin rays produced lower peak magnitude forces than the stiffer fin rays at the same frequency. Thrust and lift forces increased with increasing flapping frequency; thrust was maximized by the 500× stiffness fin rays and lift was maximized by the 1000× stiffness fin rays.

  17. Non-lethal measurement of pectoral fin aspect ratio in coral-reef fishes.

    PubMed

    Binning, S A; Fulton, C J

    2011-09-01

    This study describes a novel method for measuring pectoral fin aspect ratio (AR) on live coral-reef fishes and tests the method against traditional measurements taken from a dissected fin. No significant differences were detected among repeated fin measurements, which validates the accuracy (intact v. dissected) and precision (repeatability over several days) of fin AR measurements on live fishes. One exception highlighted issues that may arise when working with species prone to fin damage.

  18. Cooling Tests of an Air-Cooled Engine Cylinder with Copper Fins on the Barrel

    DTIC Science & Technology

    1942-07-01

    of the piston thermo- couples aro shown in figures 3 and 4. The locations of the cylinder-surface tiernocc-~ples are shown In figure 5. The crankshaft ...the =esult of improvsd fin design shows that the outside barrel temperature may be a poor crite- rion for barrel cooling. ~or example, at 0.7...dimensions in the L . aluminum-muff design Is reetrieted by limits imposed In maohiriing the fins. With aluminum fins, ae with copper fins, the fin

  19. Vortical structures in the wake of an undulating fin

    NASA Astrophysics Data System (ADS)

    Dewey, Peter A.; Carriou, Antoine; Smits, Alexander J.

    2010-11-01

    Batoid fish such as the manta ray propel themselves through the water by producing a traveling wave motion along the chord of their pectoral fin. Such a motion produces thrust through the development of an unsteady vortex street that results in a jet-like average flow. Digital particle image velocimetry (DPIV) is used to characterize the vortical patterns and structures developed in the wake of a manta ray-like fin. A DC servo motor powers a gear train to produce the traveling wave motion; whose frequency and wave length can be varied. The amplitude of the traveling wave motion linearly increases along the span of the fin. Wake morphologies for a wide spectrum of oscillation frequencies and traveling wave wavelengths are identified. A bifurcation from a 2S wake structure to a 2P wake structure is observed as the traveling wave wavelength is decreased, which corresponds to a decrease in efficiency as reported by Clark and Smits (2006). Alteration of the oscillation frequency, and thus Strouhal number, affects vortex interaction and is found to significantly modify the resulting velocity profiles in the wake of the fin. Notably, increasing the Strouhal number beyond optimal conditions, reported by Clark and Smits, corresponds to a reduction in the extent that the jet-like average flow is observed downstream of the fin.

  20. Kinematics of ribbon-fin locomotion in the bowfin, Amia calva.

    PubMed

    Jagnandan, Kevin; Sanford, Christopher P

    2013-12-01

    An elongated dorsal and/or anal ribbon-fin to produce forward and backward propulsion has independently evolved in several groups of fishes. In these fishes, fin ray movements along the fin generate a series of waves that drive propulsion. There are no published data on the use of the dorsal ribbon-fin in the basal freshwater bowfin, Amia calva. In this study, frequency, amplitude, wavelength, and wave speed along the fin were measured in Amia swimming at different speeds (up to 1.0 body length/sec) to understand how the ribbon-fin generates propulsion. These wave properties were analyzed to (1) determine whether regional specialization occurs along the ribbon-fin, and (2) to reveal how the undulatory waves are used to control swimming speed. Wave properties were also compared between swimming with sole use of the ribbon-fin, and swimming with simultaneous use of the ribbon and pectoral fins. Statistical analysis of ribbon-fin kinematics revealed no differences in kinematic patterns along the ribbon-fin, and that forward propulsive speed in Amia is controlled by the frequency of the wave in the ribbon-fin, irrespective of the contribution of the pectoral fin. This study is the first kinematic analysis of the ribbon-fin in a basal fish and the model species for Amiiform locomotion, providing a basis for understanding ribbon-fin locomotion among a broad range of teleosts.

  1. Further characterization of the F fertility inhibition systems of "unusual" Fin+ plasmids.

    PubMed Central

    Gasson, M J; Willetts, N S

    1977-01-01

    Flac mutants insensitive to transfer inhibition by R factors. JR66a and R485 were isolated and characterized. Representative mutations were cis dominant and are therefore presumed to be at the sites of action, fisU and fisV, respectively, of the FinU and FinV transfer inhibition systems encoded by JR66a and R485. The mutants were used to confirm that the FinU and FinV fertility inhibition systems are different from each other and from the FinOP, FinQ, and FinW systems of R100, R62, and R455, respectively. Together with traO and fisQ mutants of Flac, the new mutants were also used to investigate the nature of the F fertility inhibition systems encoded by a further group of "unusual" Fin+ plasmids. Of these, two incompatibility group X plasmids were found to carry finO+ genes, and of five incompatibility group I plasmids, three encoded FinQ systems, one the FinU system, and one a new system (FinR). Transfer of a variety of derepressed F-like plasmids was inhibited by the FinQ, FinU, and FinV systems, but a quantitatively very different levels; this emphasizes the differences as well as the similarities between the conjugation systems of F-like plasmids. PMID:328480

  2. Further characterization of the F fertility inhibition systems of "unusual" Fin+ plasmids.

    PubMed

    Gasson, M J; Willetts, N S

    1977-08-01

    Flac mutants insensitive to transfer inhibition by R factors. JR66a and R485 were isolated and characterized. Representative mutations were cis dominant and are therefore presumed to be at the sites of action, fisU and fisV, respectively, of the FinU and FinV transfer inhibition systems encoded by JR66a and R485. The mutants were used to confirm that the FinU and FinV fertility inhibition systems are different from each other and from the FinOP, FinQ, and FinW systems of R100, R62, and R455, respectively. Together with traO and fisQ mutants of Flac, the new mutants were also used to investigate the nature of the F fertility inhibition systems encoded by a further group of "unusual" Fin+ plasmids. Of these, two incompatibility group X plasmids were found to carry finO+ genes, and of five incompatibility group I plasmids, three encoded FinQ systems, one the FinU system, and one a new system (FinR). Transfer of a variety of derepressed F-like plasmids was inhibited by the FinQ, FinU, and FinV systems, but a quantitatively very different levels; this emphasizes the differences as well as the similarities between the conjugation systems of F-like plasmids.

  3. Development and Evolution of the Muscles of the Pelvic Fin

    PubMed Central

    Cole, Nicholas J.; Hall, Thomas E.; Don, Emily K.; Berger, Silke; Boisvert, Catherine A.; Neyt, Christine; Ericsson, Rolf; Joss, Jean; Gurevich, David B.; Currie, Peter D.

    2011-01-01

    Locomotor strategies in terrestrial tetrapods have evolved from the utilisation of sinusoidal contractions of axial musculature, evident in ancestral fish species, to the reliance on powerful and complex limb muscles to provide propulsive force. Within tetrapods, a hindlimb-dominant locomotor strategy predominates, and its evolution is considered critical for the evident success of the tetrapod transition onto land. Here, we determine the developmental mechanisms of pelvic fin muscle formation in living fish species at critical points within the vertebrate phylogeny and reveal a stepwise modification from a primitive to a more derived mode of pelvic fin muscle formation. A distinct process generates pelvic fin muscle in bony fishes that incorporates both primitive and derived characteristics of vertebrate appendicular muscle formation. We propose that the adoption of the fully derived mode of hindlimb muscle formation from this bimodal character state is an evolutionary innovation that was critical to the success of the tetrapod transition. PMID:21990962

  4. Lateral Control Jets for Finned Bodies: A Numerical Investigation

    NASA Astrophysics Data System (ADS)

    Graham, Mary Jane; Weinacht, Paul; Brandeis, Julius

    1999-11-01

    The typical jet interaction flow field is complicated due to the jet's interruption of the oncoming external flow. The qualitative features of the jet interaction flow field include regions of shock/boundary layer interaction and flow separation that have an effect on the large regions of the flow field around the body. A detailed numerical study of the interaction between a lateral jet and the external flow has been performed for a variety of missile body geometries at varying Mach numbers. The missile geometries include non-finned axisymmetric bodies and finned bodies with either strakes or aft-mounted tail fins. To obtain the numerical results, both Reynolds-averaged Navier-Stokes and Euler techniques have been applied. The computational results were compared with results from a previously published wind tunnel study that consisted primarily of global force and moment measurements. Good agreement between numerical prediction and experimental results is found.

  5. Atom-probe for FinFET dopant characterization.

    PubMed

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

    2011-05-01

    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° and 45°) 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.

  6. Fluid flow and scalar transport through porous fins

    NASA Astrophysics Data System (ADS)

    Coletti, F.; Muramatsu, K.; Schiavazzi, D.; Elkins, C. J.; Eaton, J. K.

    2014-05-01

    Lotus-type porous metals are a promising alternative for compact heat transfer applications. In lotus-type porous fins, jet impingement and transverse mixing play important roles for heat transfer: jets emerging from the pores impinge on the following fin and enhance heat transfer performance, while the transverse fluid motion advects heat away from the fin surface. By means of magnetic resonance imaging we have performed mean flow and scalar transport measurements through scaled-up replicas of two kinds of lotus-type porous fins: one with a deterministic hole pattern and staggered alignment, and one with a random hole pattern, but the same porosity and mean pore diameter. The choice of geometric parameters (fin spacing, thickness, porosity, and hole diameter) is based on previous thermal studies. The Reynolds number based on the mean pore diameter and inner velocity ranges from 80 to 3800. The measurements show that in the random hole pattern the jet characteristic length scale is substantially larger with respect to the staggered hole pattern. The random geometry also produces long coherent vortices aligned with the streamwise direction, which improves the transverse mixing. The random hole distribution causes the time mean streamlines to meander in a random-walk manner, and the diffusivity coefficient associated to the mechanical dispersion (which is nominally zero in the staggered hole configuration) is several times larger than the fluid molecular diffusivity at the higher Reynolds numbers. From the trends in maximum streamwise velocity, streamwise vorticity, and mechanical diffusivity, it is inferred that the flow undergoes a transition to an unsteady/turbulent regime around Reynolds number 300. This is supported by the measurements of concentration of an isokinetic non-buoyant plume of scalar injected upstream of the stack of fins. The total scalar diffusivity for the fully turbulent regime is found to be 22 times larger than the molecular diffusivity, but

  7. Integral finned heater and cooler for stirling engines

    SciTech Connect

    Corey, John A.

    1984-01-01

    A piston and cylinder for a Stirling engine and the like having top and bottom meshing or nesting finned conical surfaces to provide large surface areas in close proximity to the working gas for good thermal (addition and subtraction of heat) exchange to the working gas and elimination of the usual heater and cooler dead volume. The piston fins at the hot end of the cylinder are perforated to permit the gas to pass into the piston interior and through a regenerator contained therein.

  8. Study of transient behavior of finned coil heat exchangers

    NASA Technical Reports Server (NTRS)

    Rooke, S. P.; Elissa, M. G.

    1993-01-01

    The status of research on the transient behavior of finned coil cross-flow heat exchangers using single phase fluids is reviewed. Applications with available analytical or numerical solutions are discussed. Investigation of water-to-air type cross-flow finned tube heat exchangers is examined through the use of simplified governing equations and an up-wind finite difference scheme. The degenerate case of zero air-side capacitance rate is compared with available exact solution. Generalization of the numerical model is discussed for application to multi-row multi-circuit heat exchangers.

  9. Flutter estimation of S-520 sounding rocket fins

    NASA Astrophysics Data System (ADS)

    Honda, Masahisa; Onoda, Junjiro; Onojima, Noboru; Nakada, Atsushi; Isogai, Koji

    The flutter margin of the fins, which has been improved for S-520 sounding rocket of ISAS, is estimated by wind tunnel tests and numerical flutter analysis. Both methods require stiffness distribution of the fin. In this paper, a new approach of fitting of FEM model to the measured matrix of influence coefficient is applied in order to eliminate the errors in the measured stiffness data, which may otherwise make the mathematical model nonpositive definite. The results of the wind tunnel tests and numerical flutter analysis using the above fitted FEM model stiffness distribution are compared and discussed.

  10. Film Condensation of Steam on Externally Finned Horizontal Tubes.

    DTIC Science & Technology

    1985-03-01

    portion of the tube. Differential eguations were obtained for the height of condensate between fin bases, and tempera - ture distribution along the fin...boiler input power. A more detailed descrip- tion of the boiler power supply is provided by Poole (6]. The internal system pressure was measured manually ...0.2 K ir the steam tempera - ture, or an error of _ 1.0 mmHg in the system pressure would lead to an error of ± 1.2 percent in the non-condensing

  11. Is n sin θ conserved along the light path?

    NASA Astrophysics Data System (ADS)

    Noorbala, Mahdiyar; Sepehrinia, Reza

    2016-03-01

    Snell’s law states that the quantity n{sin}θ is unchanged in refraction of light passing from one medium to another. We inquire whether this is true in the general case where the speed of light varies continuously within a medium. It turns out to be an instructive exercise in application of Snell’s law and Fermat’s principle. It also provides good pedagogical problems in calculus of variations to deal with the subtleties of a variable domain of integration and inclusion of constraints. The final result of these exercises is that, contrary to an initial expectation, the answer to the question in the title is negative.

  12. SInCRe—structural interactome computational resource for Mycobacterium tuberculosis

    PubMed Central

    Metri, Rahul; Hariharaputran, Sridhar; Ramakrishnan, Gayatri; Anand, Praveen; Raghavender, Upadhyayula S.; Ochoa-Montaño, Bernardo; Higueruelo, Alicia P.; Sowdhamini, Ramanathan; Chandra, Nagasuma R.; Blundell, Tom L.; Srinivasan, Narayanaswamy

    2015-01-01

    We have developed an integrated database for Mycobacterium tuberculosis H37Rv (Mtb) that collates information on protein sequences, domain assignments, functional annotation and 3D structural information along with protein–protein and protein–small molecule interactions. SInCRe (Structural Interactome Computational Resource) is developed out of CamBan (Cambridge and Bangalore) collaboration. The motivation for development of this database is to provide an integrated platform to allow easily access and interpretation of data and results obtained by all the groups in CamBan in the field of Mtb informatics. In-house algorithms and databases developed independently by various academic groups in CamBan are used to generate Mtb-specific datasets and are integrated in this database to provide a structural dimension to studies on tuberculosis. The SInCRe database readily provides information on identification of functional domains, genome-scale modelling of structures of Mtb proteins and characterization of the small-molecule binding sites within Mtb. The resource also provides structure-based function annotation, information on small-molecule binders including FDA (Food and Drug Administration)-approved drugs, protein–protein interactions (PPIs) and natural compounds that bind to pathogen proteins potentially and result in weakening or elimination of host–pathogen protein–protein interactions. Together they provide prerequisites for identification of off-target binding. Database URL: http://proline.biochem.iisc.ernet.in/sincre PMID:26130660

  13. Sinning against nature: the theory of background conditions

    PubMed Central

    Blackford, R

    2006-01-01

    Debates about the moral and political acceptability of particular sexual practices and new technologies often include appeals to a supposed imperative to follow nature. If nature is understood as the totality of all phenomena or as those things that are not artificial, there is little prospect of developing a successful argument to impugn interference with it or sinning against it. At the same time, there are serious difficulties with approaches that seek to identify "proper" human functioning. An alternative approach is to understand interference with nature as acting in a manner that threatens basic background conditions to human choice. Arguably, the theory of background conditions helps explain much of the hostility to practices and technologies that allegedly sin against nature. The theory does not, however, entail that appeals to nature are relevant or rational. Such appeals should be subjected to sceptical scrutiny. Indeed, the theory suggests that arguments against practices and technologies that can be seen as contrary to nature sometimes exercise a psychological attraction that is disproportional to their actual cogency. PMID:17074819

  14. Sinning against nature: the theory of background conditions.

    PubMed

    Blackford, R

    2006-11-01

    Debates about the moral and political acceptability of particular sexual practices and new technologies often include appeals to a supposed imperative to follow nature. If nature is understood as the totality of all phenomena or as those things that are not artificial, there is little prospect of developing a successful argument to impugn interference with it or sinning against it. At the same time, there are serious difficulties with approaches that seek to identify "proper" human functioning. An alternative approach is to understand interference with nature as acting in a manner that threatens basic background conditions to human choice. Arguably, the theory of background conditions helps explain much of the hostility to practices and technologies that allegedly sin against nature. The theory does not, however, entail that appeals to nature are relevant or rational. Such appeals should be subjected to sceptical scrutiny. Indeed, the theory suggests that arguments against practices and technologies that can be seen as contrary to nature sometimes exercise a psychological attraction that is disproportional to their actual cogency.

  15. Sin and mental illness in the Middle Ages.

    PubMed

    Kroll, J; Bachrach, B

    1984-08-01

    The modern stereotype that in the Middle Ages there was a general belief that mental illness was caused by sin is reviewed. The authors examined 57 descriptions of mental illness (madness, possession, alcoholism, epilepsy, and combinations thereof) from pre-Crusade chronicles and saints' lives. In only 9 (16%) of these descriptions did the sources attribute the mental illness to sin or wrongdoing, and in these cases the medieval authors appeared to use this attribution for its propaganda value against an enemy of their patron saints, their monastery lands, or their religious values. The medieval sources indicate that the authors were well aware of the proximate causes of mental illness, such as humoral imbalance, intemperate diet and alcohol intake, overwork, and grief. The banality that, since God causes all things he also causes mental illness, was only used by medieval authors under special circumstances and in a minority of cases. It does not constitute evidence of superstitious and primitive notions about mental illness in the early Middle Ages.

  16. Instantaneous Observability of Tightly Coupled SINS/GPS during Maneuvers.

    PubMed

    Jiang, Junxiang; Yu, Fei; Lan, Haiyu; Dong, Qianhui

    2016-05-27

    The tightly coupled strapdown inertial navigation system (SINS)/global position system (GPS) has been widely used. The system observability determines whether the system state can be estimated by a filter efficiently or not. In this paper, the observability analysis of a two-channel and a three-channel tightly coupled SINS/GPS are performed, respectively, during arbitrary translational maneuvers and angle maneuvers, where the translational maneuver and angle maneuver are modeled. A novel instantaneous observability matrix (IOM) based on a reconstructed psi-angle model is proposed to make the theoretical analysis simpler, which starts from the observability definition directly. Based on the IOM, a series of theoretical analysis are performed. Analysis results show that almost all kinds of translational maneuver and angle maneuver can make a three-channel system instantaneously observable, but there is no one translational maneuver or angle maneuver can make a two-channel system instantaneously observable. The system's performance is investigated when the system is not instantaneously observable. A series of simulation studies based on EKF are performed to confirm the analytic conclusions.

  17. Instantaneous Observability of Tightly Coupled SINS/GPS during Maneuvers

    PubMed Central

    Jiang, Junxiang; Yu, Fei; Lan, Haiyu; Dong, Qianhui

    2016-01-01

    The tightly coupled strapdown inertial navigation system (SINS)/global position system (GPS) has been widely used. The system observability determines whether the system state can be estimated by a filter efficiently or not. In this paper, the observability analysis of a two-channel and a three-channel tightly coupled SINS/GPS are performed, respectively, during arbitrary translational maneuvers and angle maneuvers, where the translational maneuver and angle maneuver are modeled. A novel instantaneous observability matrix (IOM) based on a reconstructed psi-angle model is proposed to make the theoretical analysis simpler, which starts from the observability definition directly. Based on the IOM, a series of theoretical analysis are performed. Analysis results show that almost all kinds of translational maneuver and angle maneuver can make a three-channel system instantaneously observable, but there is no one translational maneuver or angle maneuver can make a two-channel system instantaneously observable. The system’s performance is investigated when the system is not instantaneously observable. A series of simulation studies based on EKF are performed to confirm the analytic conclusions. PMID:27240369

  18. [Acedia or the depressed between sin and illness].

    PubMed

    Alliez, J; Huber, J P

    1987-05-01

    Acedia is a term of the classical greek vocabulary that a christian author of the IVth century, Evagre the Pontic, uses in a special sense, to describe a mental state characterized among other things, by disgust and dejection, and which, according to him, falls into what became the first list of deadly sins. The word was conveyed to us by another monk of the egyptian deserts, Jean Cassien, with a change of meaning which made it very difficult to distinguish from sadness: his audience being very different from his predecessor's, as he wrote for Latins, little inclined to anachoretic life but among which developed the first great coenobitic institutions of the Occident. One century later, Pope Gregory the great removes acedia from the list of deadly sins, either because he does not distinguish it from sadness (and laziness) or because he considers it a morbid state and, as such, depending on medical care. The word has nevertheless survived until Thomas Aquinas and later, and its study provides valuable data on the mental states prefiguring our modern depressions.

  19. Transonic static and dynamic stability characteristics of a finned projectile configuration

    NASA Technical Reports Server (NTRS)

    Boyden, R. P.; Brooks, C. W., Jr.; Davenport, E. E.

    1978-01-01

    Static and dynamic stability tests were made of a finned projectile configuration with the aft-mounted fins arranged in a cruciform pattern. The tests were made at free stream Mach numbers of 0.7, 0.9, 1.1, and 1.2 in the Langley 8-foot transonic pressure tunnel. Some of the parameters measured during the tests were lift, drag, pitching moment, pitch damping, and roll damping. Configurations tested included the body with undeflected fins, the body with various fin deflections for control, and the body with fins removed. Theoretical estimates of the stability derivatives were made for the fins on configuration.

  20. Evolution and development of the homocercal caudal fin in teleosts.

    PubMed

    Moriyama, Yuuta; Takeda, Hiroyuki

    2013-10-01

    The vertebrate caudal skeleton is one of the most innovative structures in vertebrate evolution and has been regarded as an excellent model for functional morphology, a discipline that relates a structure to its function. Teleosts have an internally-asymmetrical caudal fin, called the homocercal caudal fin, formed by the upward bending of the caudal-most portion of the body axis, the ural region. This homocercal type of the caudal fin ensures powerful and complex locomotion and is thought to be one of the most important evolutionary innovations for teleosts during adaptive radiation in an aquatic environment. In this review, we summarize the past and present research of fish caudal skeletons, especially focusing on the homocercal caudal fin seen in teleosts. A series of studies with a medaka spontaneous mutant have provided important insight into the evolution and development of the homocercal caudal skeleton. By comparing developmental processes in various vertebrates, we propose a scenario for acquisition and morphogenesis of the homocercal caudal skeleton during vertebrate evolution.

  1. Zebrafish fin regeneration after cryoinjury-induced tissue damage

    PubMed Central

    Chassot, Bérénice; Pury, David

    2016-01-01

    ABSTRACT Although fin regeneration following an amputation procedure has been well characterized, little is known about the impact of prolonged tissue damage on the execution of the regenerative programme in the zebrafish appendages. To induce histolytic processes in the caudal fin, we developed a new cryolesion model that combines the detrimental effects of freezing/thawing and ischemia. In contrast to the common transection model, the damaged part of the fin was spontaneously shed within two days after cryoinjury. The remaining stump contained a distorted margin with a mixture of dead material and healthy cells that concomitantly induced two opposing processes of tissue debris degradation and cellular proliferation, respectively. Between two and seven days after cryoinjury, this reparative/proliferative phase was morphologically featured by displaced fragments of broken bones. A blastemal marker msxB was induced in the intact mesenchyme below the damaged stump margin. Live imaging of epithelial and osteoblastic transgenic reporter lines revealed that the tissue-specific regenerative programmes were initiated after the clearance of damaged material. Despite histolytic perturbation during the first week after cryoinjury, the fin regeneration resumed and was completed without further alteration in comparison to the simple amputation model. This model reveals the powerful ability of the zebrafish to restore the original appendage architecture after the extended histolysis of the stump. PMID:27215324

  2. Hydrodynamics of a Flexible Soft-Rayed Caudal Fin

    PubMed Central

    Iosilevskii, Gil

    2016-01-01

    The paper addresses hydrodynamic performance of a slender swimmer furnished with a flexible small-aspect-ratio soft-rayed caudal fin. The recoil of the fin is found by solving the coupled hydro-elastic problem, in which the structure of the fin is modeled by a cantilever of variable cross section and the hydrodynamic forces acting on it are modeled using the elongated body theory. It is shown that the recoil has practically no effect on the propulsion efficiency of anguilliform swimmers, but has a profound effect on the efficiency of carangiform swimmers, which can increase almost four-fold between low-speed (low-thrust) cruise and high-speed (high-thrust) burst. Whilst the magnitude of this effect furnishes a plausible argument in favor of burst-and-coast locomotion strategies, it also infers that carangiform swimmers cannot rely on elastic recoil of the caudal fin to be efficient throughout the usable speed range, and must actively flex it at low speeds. PMID:27695043

  3. Vortex interactions with flapping wings and fins can be unpredictable.

    PubMed

    Lentink, David; Van Heijst, Gertjan F; Muijres, Florian T; Van Leeuwen, Johan L

    2010-06-23

    As they fly or swim, many animals generate a wake of vortices with their flapping fins and wings that reveals the dynamics of their locomotion. Previous studies have shown that the dynamic interaction of vortices in the wake with fins and wings can increase propulsive force. Here, we explore whether the dynamics of the vortex interactions could affect the predictability of propulsive forces. We studied the dynamics of the interactions between a symmetrically and periodically pitching and heaving foil and the vortices in its wake, in a soap-film tunnel. The phase-locked movie sequences reveal that abundant chaotic vortex-wake interactions occur at high Strouhal numbers. These high numbers are representative for the fins and wings of near-hovering animals. The chaotic wake limits the forecast horizon of the corresponding force and moment integrals. By contrast, we find periodic vortex wakes with an unlimited forecast horizon for the lower Strouhal numbers (0.2-0.4) at which many animals cruise. These findings suggest that swimming and flying animals could control the predictability of vortex-wake interactions, and the corresponding propulsive forces with their fins and wings.

  4. Structure and Organisation of SinR, the Master Regulator of Biofilm Formation in Bacillus subtilis

    PubMed Central

    Colledge, Vicki L.; Fogg, Mark J.; Levdikov, Vladimir M.; Leech, Andrew; Dodson, Eleanor J.; Wilkinson, Anthony J.

    2011-01-01

    sinR encodes a tetrameric repressor of genes required for biofilm formation in Bacillus subtilis. sinI, which is transcribed under Spo0A control, encodes a dimeric protein that binds to SinR to form a SinR–SinI heterodimer in which the DNA-binding functions of SinR are abrogated and repression of biofilm genes is relieved. The heterodimer-forming surface comprises residues conserved between SinR and SinI. Each forms a pair of α-helices that hook together to form an intermolecular four-helix bundle. Here, we are interested in the assembly of the SinR tetramer and its binding to DNA. Size-exclusion chromatography with multi-angle laser light scattering and crystallographic analysis reveal that a DNA-binding fragment of SinR (residues 1–69) is a monomer, while a SinI-binding fragment (residues 74–111) is a tetramer arranged as a dimer of dimers. The SinR(74–111) chain forms two α-helices with the organisation of the dimer similar to that observed in the SinR–SinI complex. The tetramer is formed through interactions of residues at the C-termini of the four chains. A model of the intact SinR tetramer in which the DNA binding domains surround the tetramerisation core was built. Fluorescence anisotropy and surface plasmon resonance experiments showed that SinR binds to an oligonucleotide duplex, 5′-TTTGTTCTCTAAAGAGAACTTA-3′, containing a pair of SinR consensus sequences in inverted orientation with a Kd of 300 nM. The implications of these data for promoter binding and the curious quaternary structural transitions of SinR upon binding to (i) SinI and (ii) the SinR-like protein SlrR, which “repurposes” SinR as a repressor of autolysin and motility genes, are discussed. PMID:21708175

  5. Estudio multifrecuencia del medio interestelar cercano a HD 192281

    NASA Astrophysics Data System (ADS)

    Arnal, E. M.; Cappa, C.; Cichowolski, S.; Pineault, S.; St-Louis, N.

    Una de las causas que modifica la estructura y dinámica del medio interestelar es la acción que los vientos de las estrellas de gran masa ejercen sobre el mismo. En este trabajo, mediante el uso de datos interferométricos obtenidos en la banda de radio en la transición de 21-cm del Hidrógeno neutro y de imágenes de la emisión de continuo en las bandas de 408 y 1420 MHz, de imágenes HIRES del satélite IRAS en 60 y 100 micrones, y de observaciones de continuo obtenidas con radiotelescopios de disco simple en 2695, 4850 y 8350 MHz se ha realizado un estudio multifrecuencia de los efectos que los vientos estelares de HD 192281, una estrella de tipo espectral O5 Vn((f))p, han tenido sobre el medio interestelar que rodea a la misma.

  6. Locomotion of free-swimming ghost knifefish: anal fin kinematics during four behaviors.

    PubMed

    Youngerman, Eric D; Flammang, Brooke E; Lauder, George V

    2014-10-01

    The maneuverability demonstrated by the weakly electric ghost knifefish (Apteronotus albifrons) is a result of its highly flexible ribbon-like anal fin, which extends nearly three-quarters the length of its body and is composed of approximately 150 individual fin rays. To understand how movement of the anal fin controls locomotion we examined kinematics of the whole fin, as well as selected individual fin rays, during four locomotor behaviors executed by free-swimming ghost knifefish: forward swimming, backward swimming, heave (vertical) motion, and hovering. We used high-speed video (1000 fps) to examine the motion of the entire anal fin and we measured the three-dimensional curvature of four adjacent fin rays in the middle of the fin during each behavior to determine how individual fin rays bend along their length during swimming. Canonical discriminant analysis separated all four behaviors on anal fin kinematic variables and showed that forward and backward swimming behaviors contrasted the most: forward behaviors exhibited a large anterior wavelength and posterior amplitude while during backward locomotion the anal fin exhibited both a large posterior wavelength and anterior amplitude. Heave and hover behaviors were defined by similar kinematic variables; however, for each variable, the mean values for heave motions were generally greater than for hovering. Individual fin rays in the middle of the anal fin curved substantially along their length during swimming, and the magnitude of this curvature was nearly twice the previously measured maximum curvature for ray-finned fish fin rays during locomotion. Fin rays were often curved into the direction of motion, indicating active control of fin ray curvature, and not just passive bending in response to fluid loading.

  7. Investigation of contact resistance for fin-tube heat exchanger by means of tube expansion

    NASA Astrophysics Data System (ADS)

    Hing, Yau Kar; Raghavan, Vijay R.; Meng, Chin Wai

    2012-06-01

    An experimental study on the heat transfer performance of a fin-tube heat exchanger due to mechanical expansion of the tube by bullets has been reported in this paper. The manufacture of a fin-tube heat exchanger commonly involves inserting copper tubes into a stack of aluminium fins and expanding the tubes mechanically. The mechanical expansion is achieved by inserting a steel bullet through the tube. The steel bullet has a larger diameter than the tube and the expansion provides a firm surface contact between fins and tubes. Five bullet expansion ratios (i.e. 1.045 to 1.059) have been used in the study to expand a 9.52mm diameter tubes in a fin-tube heat exchanger. The study is conducted on a water-to-water loop experiment rig under steady state conditions. In addition, the effects of fin hardness and fin pitch are investigated in the study. The results indicate that the optimum heat transfer occurred at a bullet expansion ratio ranging from 1.049 to 1.052. It is also observed that larger fin pitches require larger bullet expansion ratios, especially with lower fin hardness. As the fin pitch increases, both fin hardness (i.e. H22 and H24) exhibit increasing heat transfer rate per fin (W/fin). With the H22 hardness temper, the increase is as much as 11% while H24 increases by 1.2%.

  8. Transcriptional components of anteroposterior positional information during zebrafish fin regeneration.

    PubMed

    Nachtrab, Gregory; Kikuchi, Kazu; Tornini, Valerie A; Poss, Kenneth D

    2013-09-01

    Many fish and salamander species regenerate amputated fins or limbs, restoring the size and shape of the original appendage. Regeneration requires that spared cells retain or recall information encoding pattern, a phenomenon termed positional memory. Few factors have been implicated in positional memory during vertebrate appendage regeneration. Here, we investigated potential regulators of anteroposterior (AP) pattern during fin regeneration in adult zebrafish. Sequence-based profiling from tissues along the AP axis of uninjured pectoral fins identified many genes with region-specific expression, several of which encoded transcription factors with known AP-specific expression or function in developing embryonic pectoral appendages. Transgenic reporter strains revealed that regulatory sequences of the transcription factor gene alx4a activated expression in fibroblasts and osteoblasts within anterior fin rays, whereas hand2 regulatory sequences activated expression in these same cell types within posterior rays. Transgenic overexpression of hand2 in all pectoral fin rays did not affect formation of the proliferative regeneration blastema, yet modified the lengths and widths of regenerating bones. Hand2 influenced the character of regenerated rays in part by elevation of the vitamin D-inactivating enzyme encoded by cyp24a1, contributing to region-specific regulation of bone metabolism. Systemic administration of vitamin D during regeneration partially rescued bone defects resulting from hand2 overexpression. Thus, bone-forming cells in a regenerating appendage maintain expression throughout life of transcription factor genes that can influence AP pattern, and differ across the AP axis in their expression signatures of these and other genes. These findings have implications for mechanisms of positional memory in vertebrate tissues.

  9. Locomotor function of the dorsal fin in teleost fishes: experimental analysis of wake forces in sunfish.

    PubMed

    Drucker, E G; Lauder, G V

    2001-09-01

    A key evolutionary transformation of the locomotor system of ray-finned fishes is the morphological elaboration of the dorsal fin. Within Teleostei, the dorsal fin primitively is a single midline structure supported by soft, flexible fin rays. In its derived condition, the fin is made up of two anatomically distinct portions: an anterior section supported by spines, and a posterior section that is soft-rayed. We have a very limited understanding of the functional significance of this evolutionary variation in dorsal fin design. To initiate empirical hydrodynamic study of dorsal fin function in teleost fishes, we analyzed the wake created by the soft dorsal fin of bluegill sunfish (Lepomis macrochirus) during both steady swimming and unsteady turning maneuvers. Digital particle image velocimetry was used to visualize wake structures and to calculate in vivo locomotor forces. Study of the vortices generated simultaneously by the soft dorsal and caudal fins during locomotion allowed experimental characterization of median-fin wake interactions. During high-speed swimming (i.e. above the gait transition from pectoral- to median-fin locomotion), the soft dorsal fin undergoes regular oscillatory motion which, in comparison with analogous movement by the tail, is phase-advanced (by 30% of the cycle period) and of lower sweep amplitude (by 1.0 cm). Undulations of the soft dorsal fin during steady swimming at 1.1 bodylength s(-1) generate a reverse von Kármán vortex street wake that contributes 12% of total thrust. During low-speed turns, the soft dorsal fin produces discrete pairs of counterrotating vortices with a central region of high-velocity jet flow. This vortex wake, generated in the latter stage of the turn and posterior to the center of mass of the body, counteracts torque generated earlier in the turn by the anteriorly positioned pectoral fins and thereby corrects the heading of the fish as it begins to translate forward away from the turning stimulus. One

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

    PubMed

    Gerhart, Sarah V; Eble, Diane M; Burger, R Michael; Oline, Stefan N; Vacaru, Ana; Sadler, Kirsten C; Jefferis, Rebecca; Iovine, M Kathryn

    2012-01-01

    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.

  11. The Cx43-like Connexin Protein Cx40.8 Is Differentially Localized during Fin Ontogeny and Fin Regeneration

    PubMed Central

    Gerhart, Sarah V.; Eble, Diane M.; Burger, R. Michael; Oline, Stefan N.; Vacaru, Ana; Sadler, Kirsten C.; Jefferis, Rebecca; Iovine, M. Kathryn

    2012-01-01

    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. PMID:22347467

  12. evx1 transcription in bony fin rays segment boundaries leads to a reiterated pattern during zebrafish fin development and regeneration.

    PubMed

    Borday, V; Thaëron, C; Avaron, F; Brulfert, A; Casane, D; Laurenti, P; Géraudie, J

    2001-02-01

    The dermoskeleton of zebrafish fins is composed of actinotrichia and segmented bony rays, or lepidotrichia, which grow by successive addition of distal segments. The present study shows that evx1, a new zebrafish even-skipped related gene (Thaëron et al., 2000) displays during bony ray morphogenesis, a unique repetitive expression pattern along the proximodistal axis of the fin. Whole-mount in situ hybridization performed on larvae and adult regenerating fins show that evx1 signal appears as parallel dash lines crossing the width of each developing and regenerating rays, in a ladder-like fashion. Cytological studies show that a subpopulation of bone forming cells (scleroblasts) expresses evx1 at the level of the joint between two adjacent segments except in the apical part of the differentiating ray where evx1 expression precedes the formation of the joint. This distal transcription is turned on again only when the latest differentiating segment reached its final size and might label the putative next segment boundary. This suggests the existence of a molecular mechanism controlling the periodic expression of evx1 which could be involved in the establishment of segment boundaries during fin ray morphogenesis, and could play a key role during dermal skeleton patterning.

  13. Establishment of a biomimetic device based on tri-layer polymer actuators--propulsion fins.

    PubMed

    Alici, Gursel; Spinks, Geoffrey; Huynh, Nam N; Sarmadi, Laleh; Minato, Rick

    2007-06-01

    We propose to use bending type tri-layer polymer actuators as propulsion fins for a biomimetic device consisting of a rigid body, like a box fish having a carapace, and paired fins running through the rigid body, like a fish having pectoral fins. The fins or polymer bending actuators can be considered as individually controlled flexible membranes. Each fin is activated with sinusoidal inputs such that there is a phase lag between the movements of successive fins to create enough thrust force for propulsion. Eight fins with 0.125 aspect ratio have been used along both sides of the rigid body to move the device in the direction perpendicular to the longitudinal axis of the body. The designed device with the paired fins was successfully tested, moving in an organic solution consisting of solvent, propylene carbonate (PC), and electrolyte. The design procedure outlined in this study is offered as a guide to making functional devices based on polymer actuators and sensors.

  14. Actuation of a robotic fish caudal fin for low reaction torque.

    PubMed

    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.

  15. Actuation of a robotic fish caudal fin for low reaction torque

    NASA Astrophysics Data System (ADS)

    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.

  16. Experimental study on thermal performance of micro pin fin heat sinks with various shapes

    NASA Astrophysics Data System (ADS)

    Hua, Junye; Li, Gui; Zhao, Xiaobao; Li, Qihe

    2017-03-01

    This paper presents a visualization experimental study on the heat transfer characteristics of various shapes of micro pin fins, including the circular, ellipse, diamond, square and triangle shape micro pin fin arrays with various equivalent diameters and pin fin density. The influences study of different sizes and shapes of pin fin on Nusselt number and heat transfer coefficient have been conducted. The results show that with the increase of the flow rate, the temperature of the bottom of the experimental section decreases. And the Nusselt number of different shapes of micro pin fins increases with the increase of Re. In which, the heat transfer performance of the ellipse shape pin fin appears better among the other shapes of pin fins. However, the higher pin fin of the ellipse shape density leads to a weaker flow performance. Besides, the micro-scale heat transfer correlation between the Nusselt number and the Reynolds number is fitted based on the experimental data.

  17. Suppression of Sin3A activity promotes differentiation of pluripotent cells into functional neurons

    PubMed Central

    Halder, Debasish; Lee, Chang-Hee; Hyun, Ji Young; Chang, Gyeong-Eon; Cheong, Eunji; Shin, Injae

    2017-01-01

    Sin3 is a transcriptional corepressor for REST silencing machinery that represses multiple neuronal genes in non-neuronal cells. However, functions of Sin3 (Sin3A and Sin3B) in suppression of neuronal phenotypes are not well characterized. Herein we show that Sin3A knockdown impedes the repressive activity of REST and enhances differentiation of pluripotent P19 cells into electrophysiologically active neurons without inducing astrogenesis. It is also found that silencing Sin3B induces neurogenesis of P19 cells with a lower efficiency than Sin3A knockdown. The results suggest that Sin3A has a more profound effect on REST repressive machinery for silencing neuronal genes in P19 cells than Sin3B. Furthermore, we show that a peptide inhibitor of Sin3A-REST interactions promotes differentiation of P19 cells into functional neurons. Observations made in studies using genetic deletion and a synthetic inhibitor suggests that Sin3A plays an important role in the repression of neuronal genes by the REST regulatory mechanism. PMID:28303954

  18. Movement and function of the pectoral fins of the larval zebrafish (Danio rerio) during slow swimming.

    PubMed

    Green, Matthew H; Ho, Robert K; Hale, Melina E

    2011-09-15

    Pectoral fins are known to play important roles in swimming for many adult fish; however, their functions in fish larvae are unclear. We examined routine pectoral fin movement during rhythmic forward swimming and used genetic ablation to test hypotheses of fin function in larval zebrafish. Fins were active throughout bouts of slow swimming. Initiation was characterized by asymmetric fin abduction that transitioned to alternating rhythmic movement with first fin adduction. During subsequent swimming, fin beat amplitude decreased while tail beat amplitude increased over swimming speeds ranging from 1.47 to 4.56 body lengths per second. There was no change in fin or tail beat frequency with speed (means ± s.d.: 28.2±3.5 and 29.6±1.9 Hz, respectively). To examine potential roles of the pectoral fins in swimming, we compared the kinematics of finless larvae generated with a morpholino knockdown of the gene fgf24 to those of normal fish. Pectoral fins were not required for initiation nor did they significantly impact forward rhythmic swimming. We investigated an alternative hypothesis that the fins function in respiration. Dye visualization demonstrated that pectoral fin beats bring distant fluid toward the body and move it caudally behind the fins, disrupting the boundary layer along the body's surface, a major site of oxygen absorption in larvae. Larval zebrafish also demonstrated more fin beating in low oxygen conditions. Our data reject the hypothesis that the pectoral fins of larval zebrafish have a locomotor function during slow, forward locomotion, but are consistent with the hypothesis that the fins have a respiratory function.

  19. Measurement of frost characteristics on heat exchanger fins. Part 2: Data and analysis

    SciTech Connect

    Chen, H.; Thomas, L.; Besant, R.W.

    1999-07-01

    Part 1 of this paper described the frost growth test facility and instrumentation. In Part 2, results are presented for typical operating conditions with frost growth on heat exchanger fins. Typical data are presented for frost height distributions on fins, increase in pressure loss for airflow through a finned test section, frost mass accumulation on fins, and heat rate. Special attention is given to the uncertainty in each of these measurements and calculations.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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.

  2. Self-propelled flexible fin in the wake of a circular cylinder

    NASA Astrophysics Data System (ADS)

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

    2016-11-01

    The behavior of a self-propelled flexible fin behind a circular cylinder in a uniform flow was explored using the immersed boundary method. The transverse heaving motion of the leading edge of the fin was prescribed, whereas the lateral behavior was spontaneously determined by the hydrodynamic interactions between the fin and the fluid environment. Three different behaviors were observed: propulsion upstream, drift downstream, and holding stationary at an equilibrium position. In a uniform flow, the fin could not overcome the positive net drag, and it drifted downstream. By contrast, a fin in the wake of a cylinder was propelled toward the circular cylinder during the heaving motion. The trailing edge of the fin passively fluttered along the oncoming vortices, thereby propelling the fin upstream. During the upstream propulsion behavior, the fin was propelled through the vortex cores. The fin was observed to remain stationary at a heaving frequency equal to the vortex shedding frequency, and a slaloming behavior was observed between the oncoming vortical structures. The fin was not propelled toward the cylinder during the slaloming behavior; rather, it lingered at a certain streamwise distance from the cylinder. Several equilibrium positions were dynamically determined from the interaction between the fin and the vortical fluid environment. The equilibrium position depended on the initial longitudinal position and the phase of the fin heaving motion with respect to the phase of the vortex shedding. The power input required to drive the heaving motion was reduced during the slaloming behavior.

  3. Advanced composite vertical fin for L-1011 aircraft

    NASA Technical Reports Server (NTRS)

    Jackson, A. C.

    1984-01-01

    The structural box of the L-1011 vertical fin was redesigned using advanced composite materials. The box was fabricated and ground tested to verify the structural integrity. This report summarizes the complete program starting with the design and analysis and proceeds through the process development ancillary test program production readiness verification testing, fabrication of the full-scale fin boxes and the full-scale ground testing. The program showed that advanced composites can economically and effectively be used in the design and fabrication of medium primary structures for commercial aircraft. Static-strength variability was demonstrated to be comparable to metal structures and the long term durability of advanced composite components was demonstrated.

  4. Plate-fin panel heat exchanger and panel components thereof

    SciTech Connect

    Heronemus, W.E.

    1985-02-05

    A plate-fin panel for a heat exchanger may be either formed as an aluminum extrusion or fabricated from a corrugated metal sheet sandwiched between two flat metal sheets. The extruded aluminum version may be clad with protective sheet metal jackets made of, or coated with, a corrosion resistant Cu-Ni alloy. Individual panel sections can be joined together by tongue and groove engagement to obtain a total desired panel width if available extrusion press or rolling mill capacity is insufficient. The plate-fin panels are assembled into slotted headering plates, and a layer of synthetic plastics potting compound seals dissimilar metal joints against electrolytic corrosion as well as leakage and provides sufficient adhesive strength to reduce or eliminate the need for welding the panels to the headers. Mechanical brush or hydraulic jet apparatus is capable of continuously or intermittently cleaning slime or encrustations from all panel surfaces exposed to seawater.

  5. Effect of Vapor Velocity during Condensation on Horizontal Finned Tubes

    DTIC Science & Technology

    1988-12-01

    surface area (m2 ) b Fin spacing (mm) Ci Sieder -Tate type coefficient used in Equation (4.5) C p Specific heat of cooling water (J/kgK) Di Inside diameter...and auxiliary condensers, together with the energy lost to the environment. Raw data were processed immediately using an assumed value for the Sieder ...sets were collected, the data were reprocessed using a new Sieder -Tate coefficient found by the modified Wilson method. 40 F. TUBES TESTED For this

  6. Large Scale Density Estimation of Blue and Fin Whales (LSD)

    DTIC Science & Technology

    2014-09-30

    interactions with human activity requires knowledge of how many animals are present in an area during a specific time period. Many marine mammal species...assumptions about animal distribution around the sensors, or both. The goal of this research is to develop and implement a new method for...estimating blue and fin whale density that is effective over large spatial scales and is designed to cope with spatial variation in animal density utilizing

  7. Ancestry of motor innervation to pectoral fin and forelimb

    PubMed Central

    Ma, Leung-Hang; Gilland, Edwin; Bass, Andrew H.; Baker, Robert

    2010-01-01

    Motor innervation to the tetrapod forelimb and fish pectoral fin is assumed to share a conserved spinal cord origin, despite major structural and functional innovations of the appendage during the vertebrate water-to-land transition. In this paper, we present anatomical and embryological evidence showing that pectoral motoneurons also originate in the hindbrain among ray-finned fish. New and previous data for lobe-finned fish, a group that includes tetrapods, and more basal cartilaginous fish showed pectoral innervation that was consistent with a hindbrain-spinal origin of motoneurons. Together, these findings support a hindbrain–spinal phenotype as the ancestral vertebrate condition that originated as a postural adaptation for pectoral control of head orientation. A phylogenetic analysis indicated that Hox gene modules were shared in fish and tetrapod pectoral systems. We propose that evolutionary shifts in Hox gene expression along the body axis provided a transcriptional mechanism allowing eventual decoupling of pectoral motoneurons from the hindbrain much like their target appendage gained independence from the head. PMID:20975699

  8. Heat transfer coefficients for staggered arrays of short pin fins

    NASA Technical Reports Server (NTRS)

    Vanfossen, G. J.

    1981-01-01

    Short pin fins are often used to increase that heat transfer to the coolant in the trailing edge of a turbine blade. Due primarily to limits of casting technology, it is not possible to manufacture pins of optimum length for heat transfer purposes in the trailing edge region. In many cases the pins are so short that they actually decrease the total heat transfer surface area compared to a plain wall. A heat transfer data base for these short pins is not available in the literature. Heat transfer coefficients on pin and endwall surfaces were measured for several staggered arrays of short pin fins. The measured Nusselt numbers when plotted versus Reynolds numbers were found to fall on a single curve for all surfaces tested. The heat transfer coefficients for the short pin fins (length to diameter ratios of 1/2 and 2) were found to be about a factor of two lower than data from the literature for longer pin arrays (length to diameter ratios of about 8).

  9. The effect of ether anesthesia on fin-clipping rate

    USGS Publications Warehouse

    Eschmeyer, Paul H.

    1953-01-01

    As part of an experimental program to learn the effects of stocking lake trout (Salvelinus namaycush) in Lake Superior, 141, 392 fingerlings were marked at the Charlevoix (Michigan) Station of the U.S. Fish and Wildlife Service in October 1952. The adipose fin was removed from all fish, the right pelvic from the remainder. A random sample of 2, 417 of the fish showed an average total length of 4.0 inches (range, 2.7 to 5.4). The mean weight of all fish marked was slightly less than one-third ounce (49 fish per pound). The local women, none of whom had previous experience in the work, were employed to mark the fish. Bone-cutting forceps were used for excision of the fins, and each worker wore a bobbinet glove to facilitate handling of the fish. On alternate days the fish were anesthetized with ether before marking, to determine the effect of its use on the fin-clipping rate.

  10. Prediction of forces and moments on finned bodies at high angle of attack in transonic flow

    SciTech Connect

    Oberkampf, W. L.

    1981-04-01

    This report describes a theoretical method for the prediction of fin forces and moments on bodies at high angle of attack in subsonic and transonic flow. The body is assumed to be a circular cylinder with cruciform fins (or wings) of arbitrary planform. The body can have an arbitrary roll (or bank) angle, and each fin can have individual control deflection. The method combines a body vortex flow model and lifting surface theory to predict the normal force distribution over each fin surface. Extensive comparisons are made between theory and experiment for various planform fins. A description of the use of the computer program that implements the method is given.

  11. Electronic properties of a new structured Sin/O superlattice

    NASA Astrophysics Data System (ADS)

    Yu, S.; Zhang, L.; Xu, Y. X.; Wu, S. Q.; Zhu, Z. Z.

    2016-11-01

    Silicon is a material which dominants the semiconductor industry and has a well-established processing technology based on it. However, silicon has an indirect-bandgap and is not efficient in light emitting. This limits its applications in optoelectronics. In this paper, we proposed a new structural model for the silicon-based superlattice, i.e., the Sin/O one. The model consists of alternating films of n-layers of Si and a monolayer of oxygen along z-direction, together with a surface cell of Si(001) (2×1) reconstruction in the x-y plane. The importance of employing such a Si(001) (2×1) reconstruction is that all the electrons at interface can be strongly bonded. Our results showed interesting electronic properties, e.g., the band folding and large band gap of bulk Si, when the thickness of the silicon layers was increased (but still thin). Our structure might also offer other interesting properties.

  12. Sin and suffering in a Catholic understanding of medical ethics.

    PubMed

    Garcia, J L A

    2006-08-01

    Drawing chiefly on recent sources, in Part One I sketch an untraditional way of articulating what I claim to be central elements of traditional Catholic morality, treating it as based in virtues, focused on the recipients ("patients") of our attention and concern, and centered in certain person-to-person role-relationships. I show the limited and derivative places of "natural law," and therefore of sin, within that framework. I also sketch out some possible implications for medical ethics of this approach to moral theory, and briefly contrast these with the influential alternative offered by the "principlism" of Beauchamp and Childress. In Part Two, I turn to a Catholic understanding of the nature and meaning of human suffering, drawing especially on writings and addresses of the late Pope John Paul II. He reminds us that physical and mental suffering can provide an opportunity to share in Christ's salvific sacrifice, better to see the nature of our earthly vocation, and to reflect on the dependence that inheres in human existence. At various places, and especially in my conclusion, I suggest a few ways in which this can inform bioethical reflection on morally appropriate responses to those afflicted by physical or mental pain, disability, mental impairment, disease, illness, and poor health prospects. My general point is that mercy must be informed by appreciation of the person's dignity and status. Throughout, my approach is philosophical rather than theological.

  13. Fish larvae exploit edge vortices along their dorsal and ventral fin folds to propel themselves

    PubMed Central

    Müller, Ulrike K.; van Leeuwen, Johan L.

    2016-01-01

    Larvae of bony fish swim in the intermediate Reynolds number (Re) regime, using body- and caudal-fin undulation to propel themselves. They share a median fin fold that transforms into separate median fins as they grow into juveniles. The fin fold was suggested to be an adaption for locomotion in the intermediate Reynolds regime, but its fluid-dynamic role is still enigmatic. Using three-dimensional fluid-dynamic computations, we quantified the swimming trajectory from body-shape changes during cyclic swimming of larval fish. We predicted unsteady vortices around the upper and lower edges of the fin fold, and identified similar vortices around real larvae with particle image velocimetry. We show that thrust contributions on the body peak adjacent to the upper and lower edges of the fin fold where large left–right pressure differences occur in concert with the periodical generation and shedding of edge vortices. The fin fold enhances effective flow separation and drag-based thrust. Along the body, net thrust is generated in multiple zones posterior to the centre of mass. Counterfactual simulations exploring the effect of having a fin fold across a range of Reynolds numbers show that the fin fold helps larvae achieve high swimming speeds, yet requires high power. We conclude that propulsion in larval fish partly relies on unsteady high-intensity vortices along the upper and lower edges of the fin fold, providing a functional explanation for the omnipresence of the fin fold in bony-fish larvae. PMID:27009180

  14. Fish larvae exploit edge vortices along their dorsal and ventral fin folds to propel themselves.

    PubMed

    Li, Gen; Müller, Ulrike K; van Leeuwen, Johan L; Liu, Hao

    2016-03-01

    Larvae of bony fish swim in the intermediate Reynolds number (Re) regime, using body- and caudal-fin undulation to propel themselves. They share a median fin fold that transforms into separate median fins as they grow into juveniles. The fin fold was suggested to be an adaption for locomotion in the intermediate Reynolds regime, but its fluid-dynamic role is still enigmatic. Using three-dimensional fluid-dynamic computations, we quantified the swimming trajectory from body-shape changes during cyclic swimming of larval fish. We predicted unsteady vortices around the upper and lower edges of the fin fold, and identified similar vortices around real larvae with particle image velocimetry. We show that thrust contributions on the body peak adjacent to the upper and lower edges of the fin fold where large left-right pressure differences occur in concert with the periodical generation and shedding of edge vortices. The fin fold enhances effective flow separation and drag-based thrust. Along the body, net thrust is generated in multiple zones posterior to the centre of mass. Counterfactual simulations exploring the effect of having a fin fold across a range of Reynolds numbers show that the fin fold helps larvae achieve high swimming speeds, yet requires high power. We conclude that propulsion in larval fish partly relies on unsteady high-intensity vortices along the upper and lower edges of the fin fold, providing a functional explanation for the omnipresence of the fin fold in bony-fish larvae.

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

    SciTech Connect

    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.

  16. A shift in anterior-posterior positional information underlies the fin-to-limb evolution.

    PubMed

    Onimaru, Koh; Kuraku, Shigehiro; Takagi, Wataru; Hyodo, Susumu; Sharpe, James; Tanaka, Mikiko

    2015-08-18

    The pectoral fins of ancestral fishes had multiple proximal elements connected to their pectoral girdles. During the fin-to-limb transition, anterior proximal elements were lost and only the most posterior one remained as the humerus. Thus, we hypothesised that an evolutionary alteration occurred in the anterior-posterior (AP) patterning system of limb buds. In this study, we examined the pectoral fin development of catshark (Scyliorhinus canicula) and revealed that the AP positional values in fin buds are shifted more posteriorly than mouse limb buds. Furthermore, examination of Gli3 function and regulation shows that catshark fins lack a specific AP patterning mechanism, which restricts its expression to an anterior domain in tetrapods. Finally, experimental perturbation of AP patterning in catshark fin buds results in an expansion of posterior values and loss of anterior skeletal elements. Together, these results suggest that a key genetic event of the fin-to-limb transformation was alteration of the AP patterning network.

  17. Experimental investigation of vortices shed by various wing fin configurations. M.S. Thesis. Final Report

    NASA Technical Reports Server (NTRS)

    Iversen, J.; Moghadam, M.

    1981-01-01

    Forty-six different fins, which were members of twelve plan-form families, were tested. A two dimensional Boeing single element airfoil at an angle of attack of eight degrees and a sweepback angle of thirty-two was used to simulate a portion of the wing of a generator aircraft. Various free stream velocities were used to test any individual fin at its particular angle of attack. While the fin itself was mounted on the upper surface of the generator model, the angle of attack of each fin was varied until stall was reached and/or passed. The relative fin vortex strengths were measured in two ways. First, the maximum angular velocity of a four blade rotor placed in the fin vortex center was measured with the use of a stroboscope. Second, the maximum rolling moment on a following wing model placed in the fin vortex center was measured by a force balance.

  18. The influence of culture on the international management of shark finning.

    PubMed

    Dell'Apa, Andrea; Smith, M Chad; 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.

  19. Pectoral Fin of the Megamouth Shark: Skeletal and Muscular Systems, Skin Histology, and Functional Morphology

    PubMed Central

    Tomita, Taketeru; Tanaka, Sho; Sato, Keiichi; Nakaya, Kazuhiro

    2014-01-01

    This is the first known report on the skeletal and muscular systems, and the skin histology, of the pectoral fin of the rare planktivorous megamouth shark Megachasma pelagios. The pectoral fin is characterized by three features: 1) a large number of segments in the radial cartilages; 2) highly elastic pectoral fin skin; and 3) a vertically-rotated hinge joint at the pectoral fin base. These features suggest that the pectoral fin of the megamouth shark is remarkably flexible and mobile, and that this flexibility and mobility enhance dynamic lift control, thus allowing for stable swimming at slow speeds. The flexibility and mobility of the megamouth shark pectoral fin contrasts with that of fast-swimming sharks, such as Isurus oxyrhinchus and Lamna ditropis, in which the pectoral fin is stiff and relatively immobile. PMID:24465959

  20. The Influence of Culture on the International Management of Shark Finning

    NASA Astrophysics Data System (ADS)

    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.

  1. Room-temperature direct band-gap electroluminescence from germanium (111)-fin light-emitting diodes

    NASA Astrophysics Data System (ADS)

    Tani, Kazuki; Saito, Shin-ichi; Oda, Katsuya; Miura, Makoto; Wakayama, Yuki; Okumura, Tadashi; Mine, Toshiyuki; Ido, Tatemi

    2017-03-01

    Germanium (Ge) (111) fins of 320 nm in height were successfully fabricated using a combination of flattening sidewalls of a silicon (Si) fin structure by anisotropic wet etching with tetramethylammonium hydroxide, formation of thin Ge fins by selective Si oxidation in SiGe layers, and enlargement of Ge fins by Ge homogeneous epitaxial growth. The excellent electrical characteristics of Ge(111) fin light-emitting diodes, such as an ideality factor of 1.1 and low dark current density of 7.1 × 10‑5 A cm‑2 at reverse bias of ‑2 V, indicate their good crystalline quality. A tensile strain of 0.2% in the Ge fins, which originated from the mismatch of the thermal expansion coefficients between Ge and the covering SiO2 layers, was expected from the room-temperature photoluminescence spectra, and room-temperature electroluminescence corresponding to the direct band-gap transition was observed from the Ge fins.

  2. Design Optimization of Pin Fin Geometry Using Particle Swarm Optimization Algorithm

    PubMed Central

    Hamadneh, Nawaf; Khan, Waqar A.; Sathasivam, Saratha; Ong, Hong Choon

    2013-01-01

    Particle swarm optimization (PSO) is employed to investigate the overall performance of a pin fin.The following study will examine the effect of governing parameters on overall thermal/fluid performance associated with different fin geometries, including, rectangular plate fins as well as square, circular, and elliptical pin fins. The idea of entropy generation minimization, EGM is employed to combine the effects of thermal resistance and pressure drop within the heat sink. A general dimensionless expression for the entropy generation rate is obtained by considering a control volume around the pin fin including base plate and applying the conservations equations for mass and energy with the entropy balance. Selected fin geometries are examined for the heat transfer, fluid friction, and the minimum entropy generation rate corresponding to different parameters including axis ratio, aspect ratio, and Reynolds number. The results clearly indicate that the preferred fin profile is very dependent on these parameters. PMID:23741525

  3. Cartilage and related tissues in the trunk and fins of teleosts.

    PubMed Central

    Benjamin, M; Ralphs, J R; Eberewariye, O S

    1992-01-01

    The structure and distribution of cartilage and related tissues in the dorsal fin, caudal fin and vertebrae of teleosts were studied in 11 species. With the exception of Zellknorpel, all the tissues previously described in teleost heads were present in the trunk and fins, although they were found in smaller quantities. The distribution of the supporting tissues indicates that they serve different functions. Hyaline cartilage was restricted to vertebral and fin bones undergoing endochondral ossification, fibro/cell-rich cartilage acted as an articular tissue, and hyaline-cell cartilage and its subtypes formed flexible and resilient supports in the caudal fin. Mucous connective tissue was packed as a space-filler around neurovascular bundles in fin rays, and chondroid bone was found beneath articular surfaces. The differences between cranial, and trunk and fin supporting tissues may reflect developmental as well as functional differences between the cranial and postcranial skeleton. Images Fig. 2 Fig. 3 PMID:1294559

  4. Identification of Genetic Suppressors of the Sin3A Knockdown Wing Phenotype

    PubMed Central

    Fox, Stephanie; Gammouh, Sarah; Pile, Lori A.

    2012-01-01

    The role of the Sin3A transcriptional corepressor in regulating the cell cycle is established in various metazoans. Little is known, however, about the signaling pathways that trigger or are triggered by Sin3A function. To discover genes that work in similar or opposing pathways to Sin3A during development, we have performed an unbiased screen of deficiencies of the Drosophila third chromosome. Additionally, we have performed a targeted loss of function screen to identify cell cycle genes that genetically interact with Sin3A. We have identified genes that encode proteins involved in regulation of gene expression, signaling pathways and cell cycle that can suppress the curved wing phenotype caused by the knockdown of Sin3A. These data indicate that Sin3A function is quite diverse and impacts a wide variety of cellular processes. PMID:23166712

  5. First description of a musculoskeletal linkage in an adipose fin: innovations for active control in a primitively passive appendage.

    PubMed

    Stewart, Thomas A; Hale, Melina E

    2013-01-07

    Adipose fins are enigmatic appendages found between the dorsal and caudal fins of some teleostean fishes. Long thought to be vestigial, degenerate second dorsal fins, remnants of the primitive gnathostome condition, adipose fins have since been recognized as novel morphologies. Unique among the fins of extant fishes, adipose fins have uniformly been described as passive structures, with no associated musculature. Here we provide the first description of a musculoskeletal linkage in an adipose fin, identified in the sun catfish Horabagrus brachysoma. Modified supracarinalis posterior muscles insert from the dorsal midline anterior to the adipose fin by tendons onto the fin base. An additional pair of posterior adipose-fin muscles also inserts upon the fin base and lay posterolateral to the fin, superficial to the axial muscle. This musculoskeletal linkage is an evolutionary innovation, a novel mechanism for controlling adipose-fin movement. These muscles appear to exemplify two approaches by which fins evolve to be actively controlled. We hypothesize that the anterior muscles arose through co-option of an existing fin linkage, while the posterior muscles originated as de novo fin muscles. These findings present adipose fins as a rich system within which to explore the evolution of novel vertebrate appendages.

  6. Functional subdivision of fin protractor and retractor muscles underlies pelvic fin walking in the African lungfish Protopterus annectens.

    PubMed

    Aiello, Brett R; King, Heather M; Hale, Melina E

    2014-10-01

    African lungfish Protopterus annectens can produce rotational movements around the joint between the pelvis and the pelvic fin, allowing these animals to walk across benthic substrates. In tetrapods, limb rotation at the hip joint is a common feature of substrate-based locomotion. For sprawling tetrapods, rotation can involve nine or more muscles, which are often robust and span multiple joints. In contrast, P. annectens uses a modest morphology of two fan-shaped muscles, the pelvic fin protractor and retractor, to accomplish this movement. We hypothesized that functional subdivision, coupled with their broad insertions on the femur, allows each of these muscles to pull on the limb from multiple directions and provides a mechanism for fin rotation. To test this hypothesis, we examined the muscle activity at three locations in both the protractor and the retractor muscles during walking. Electromyograms show differences in the timing of muscle activation between dorsal and ventral regions of each muscle, suggesting that each muscle is functionally subdivided once. The subdivisions demonstrate sequential onsets of muscle activity and overlap of activity between regions, which are also features of limb control in tetrapods. These data indicate that subdivisions of protractor and retractor muscles impart functional complexity to a morphologically simple system, and suggest a mechanism that allows lungfish to produce a tetrapod-like walking gait with only two muscles. As one of few extant sarcopterygian fishes, P. annectens may provide important functional data to inform interpretation of limb movement of fossil relatives.

  7. Estudio multifrecuencia del medio interestelar cercano a HD 192281

    NASA Astrophysics Data System (ADS)

    Arnal, E. M.; Cappa, C. E.; Cichowolski, S.; Pineault, S.; St-Louis, N.

    Una de las causas que modifica la estructura y dinámica del medio interestelar es la acción que los vientos de las estrellas de gran masa ejercen sobre el mismo. En este trabajo, mediante el uso de datos interferométricos obtenidos en la banda de radio en la transición de λ˜21-cm del hidrógeno neutro y de imágenes de la emisión de continuo en las bandas de 408 y 1420 MHz, de imágenes HIRES del satélite IRAS en 60 y 100μm, y de observaciones de continuo obtenidas con radiotelescopios de disco simple en 2695, 4850 y 8350 MHz se ha realizado un estudio multifrecuencia de los efectos que los vientos estelares de HD 192281, una estrella de tipo espectral O5,Vn((f))p, han tenido sobre el medio interestelar que rodea a la misma.

  8. An automated procedure for analyzing the effects of vortex-induced fin pressure on roll torque for a finned body of revolution.

    SciTech Connect

    Vijlee, Shazib Z.

    2004-09-01

    In flight tests, certain finned bodies of revolution firing lateral jets experience slower spin rates than expected. The primary cause for the reduced spin rate is the interaction between the lateral jets and the freestream air flowing past the body. This interaction produces vortices that interact with the fins (Vortex-Fin Interaction (VFI)) altering the pressure distribution over the fins and creating torque that counteracts the desired spin (counter torque). The current task is to develop an automated procedure for analyzing the pressures measured at an array of points on the fin surfaces of a body tested in a production-scale wind tunnel to determine the VFI-induced roll torque and compare it to the roll torque experimentally measured with an aerodynamic balance. Basic pressure, force, and torque relationships were applied to finite elements defined by the pressure measurement locations and integrated across the fin surface. The integrated fin pressures will help assess the distinct contributions of the individual fins to the counter torque and aid in correlating the counter torque with the positions and strengths of the vortices. The methodology produced comparisons of the effects of VFI for varying flow conditions such as freestream Mach number and dynamic pressure. The results show that for some cases the calculated counter torque agreed with the measured counter torque; however, the results were less consistent with increased freestream Mach numbers and dynamic pressures.

  9. Performance enhancement of fin attached ice-on-coil type thermal storage tank for different fin orientations using constrained and unconstrained simulations

    NASA Astrophysics Data System (ADS)

    Kim, M. H.; Duong, X. Q.; Chung, J. D.

    2017-03-01

    One of the drawbacks in latent thermal energy storage system is the slow charging and discharging time due to the low thermal conductivity of the phase change materials (PCM). This study numerically investigated the PCM melting process inside a finned tube to determine enhanced heat transfer performance. The influences of fin length and fin numbers were investigated. Also, two different fin orientations, a vertical and horizontal type, were examined, using two different simulation methods, constrained and unconstrained. The unconstrained simulation, which considers the density difference between the solid and liquid PCM showed approximately 40 % faster melting rate than that of constrained simulation. For a precise estimation of discharging performance, unconstrained simulation is essential. Thermal instability was found in the liquid layer below the solid PCM, which is contrary to the linear stability theory, due to the strong convection driven by heat flux from the coil wall. As the fin length increases, the area affected by the fin becomes larger, thus the discharging time becomes shorter. The discharging performance also increased as the fin number increased, but the enhancement of discharging performance by more than two fins was not discernible. The horizontal type shortened the complete melting time by approximately 10 % compared to the vertical type.

  10. Median fin function in bluegill sunfish Lepomis macrochirus: streamwise vortex structure during steady swimming.

    PubMed

    Tytell, Eric D

    2006-04-01

    Fishes have an enormous diversity of body shapes and fin morphologies. From a hydrodynamic standpoint, the functional significance of this diversity is poorly understood, largely because the three-dimensional flow around swimming fish is almost completely unknown. Fully three-dimensional volumetric flow measurements are not currently feasible, but measurements in multiple transverse planes along the body can illuminate many of the important flow features. In this study, I analyze flow in the transverse plane at a range of positions around bluegill sunfish Lepomis macrochirus, from the trailing edges of the dorsal and anal fins to the near wake. Simultaneous particle image velocimetry and kinematic measurements were performed during swimming at 1.2 body lengths s(-1) to describe the streamwise vortex structure, to quantify the contributions of each fin to the vortex wake, and to assess the importance of three-dimensional flow effects in swimming. Sunfish produce streamwise vortices from at least eight distinct places, including both the dorsal and ventral margins of the soft dorsal and anal fins, and the tips and central notched region of the caudal fin. I propose a three-dimensional structure of the vortex wake in which these vortices from the caudal notch are elongated by the dorso-ventral cupping motion of the tail, producing a structure like a hairpin vortex in the caudal fin vortex ring. Vortices from the dorsal and anal fin persist into the wake, probably linking up with the caudal fin vortices. These dorsal and anal fin vortices do not differ significantly in circulation from the two caudal fin tip vortices. Because the circulations are equal and the length of the trailing edge of the caudal fin is approximately equal to the combined trailing edge length of the dorsal and anal fins, I argue that the two anterior median fins produce a total force that is comparable to that of the caudal fin. To provide additional detail on how different positions contribute to

  11. Optimization of an Internally Finned Rotating Heat Pipe.

    DTIC Science & Technology

    1980-09-01

    analysis code within the COPES program, it makes the analysis code much more transportable between different computer systems , a capability which easily... code . In encoding formula (11-11) [1) for mass flow rate in FORTRAN, the’ sin € term was dropped. The correct form of the equation is shown below...15 1. The Sonic Limit ----------------- 15 2. Boiling Limit-------------------16 3. Entrainment Limit ------------------ 17 4. Condensing Limit

  12. Bacillus anthracis sin Locus and Regulation of Secreted Proteases ▿ †

    PubMed Central

    Pflughoeft, Kathryn J.; Sumby, Paul; Koehler, Theresa M.

    2011-01-01

    Bacillus anthracis shares many regulatory loci with the nonpathogenic Bacillus species Bacillus subtilis. One such locus is sinIR, which in B. subtilis controls sporulation, biofilm formation, motility, and competency. As B. anthracis is not known to be motile, to be naturally competent, or to readily form biofilms, we hypothesized that the B. anthracis sinIR regulon is distinct from that of B. subtilis. A genome-wide expression microarray analysis of B. anthracis parental and sinR mutant strains indicated limited convergence of the B. anthracis and B. subtilis SinR regulons. The B. anthracis regulon includes homologues of some B. subtilis SinR-regulated genes, including the signal peptidase gene sipW near the sinIR locus and the sporulation gene spoIIE. The B. anthracis SinR protein also negatively regulates transcription of genes adjacent to the sinIR locus that are unique to the Bacillus cereus group species. These include calY and inhA1, structural genes for the metalloproteases camelysin and immune inhibitor A1 (InhA1), which have been suggested to be associated with virulence in B. cereus and B. anthracis, respectively. Electrophoretic mobility shift assays revealed direct binding of B. anthracis SinR to promoter DNA from strongly regulated genes, such as calY and sipW, but not to the weakly regulated inhA1 gene. Assessment of camelysin and InhA1 levels in culture supernates from sinR-, inhA1-, and calY-null mutants showed that the concentration of InhA1 in the culture supernatant is inversely proportional to the concentration of camelysin. Our data are consistent with a model in which InhA1 protease levels are controlled at the transcriptional level by SinR and at the posttranslational level by camelysin. PMID:21131488

  13. Finned Carbon-Carbon Heat Pipe with Potassium Working Fluid

    NASA Technical Reports Server (NTRS)

    Juhasz, Albert J.

    2010-01-01

    This elemental space radiator heat pipe is designed to operate in the 700 to 875 K temperature range. It consists of a C-C (carbon-carbon) shell made from poly-acrylonitride fibers that are woven in an angle interlock pattern and densified with pitch at high process temperature with integrally woven fins. The fins are 2.5 cm long and 1 mm thick, and provide an extended radiating surface at the colder condenser section of the heat pipe. The weave pattern features a continuous fiber bath from the inner tube surface to the outside edges of the fins to maximize the thermal conductance, and to thus minimize the temperature drop at the condenser end. The heat pipe and radiator element together are less than one-third the mass of conventional heat pipes of the same heat rejection surface area. To prevent the molten potassium working fluid from eroding the C C heat pipe wall, the shell is lined with a thin-walled, metallic tube liner (Nb-1 wt.% Zr), which is an integral part of a hermetic metal subassembly which is furnace-brazed to the inner surface of the C-C tube. The hermetic metal liner subassembly includes end caps and fill tubes fabricated from the same Nb-1Zr alloy. A combination of laser and electron beam methods is used to weld the end caps and fill tubes. A tungsten/inert gas weld seals the fill tubes after cleaning and charging the heat pipes with potassium. The external section of this liner, which was formed by a "Uniscan" rolling process, transitions to a larger wall thickness. This section, which protrudes beyond the C-C shell, constitutes the "evaporator" part of the heat pipe, while the section inside the shell constitutes the condenser of the heat pipe (see figure).

  14. N. meningitidis 1681 is a member of the FinO family of RNA chaperones

    PubMed Central

    Chaulk, Steven; Lu, Jun; Tan, Kemin; Arthur, David C; Edwards, Ross A; Frost, Laura S; Joachimiak, Andrzej

    2010-01-01

    The conjugative transfer of F-like plasmids between bacteria is regulated by the plasmid-encoded RNA chaperone, FinO, which facilitates sense—antisense RNA interactions to regulate plasmid gene expression. FinO was thought to adopt a unique structure, however many putative homologs have been identified in microbial genomes and are considered members of the FinO_conjugation_repressor superfamily. We were interested in determining whether other members were also able to bind RNA and promote duplex formation, suggesting that this motif does indeed identify a putative RNA chaperone. We determined the crystal structure of the N. meningitidis MC58 protein NMB1681. It revealed striking similarity to FinO, with a conserved fold and a large, positively charged surface that could function in RNA interactions. Using assays developed to study FinO-FinP sRNA interactions, NMB1681, like FinO, bound tightly to FinP RNA stem-loops with short 5′ and 3′ single-stranded tails but not to ssRNA. It also was able to catalyze strand exchange between an RNA duplex and a complementary single-strand, and facilitated duplexing between complementary RNA hairpins. Finally, NMB1681 was able to rescue a finO deficiency and repress F plasmid conjugation. This study strongly suggests that NMB1681 is a FinO-like RNA chaperone that likely regulates gene expression through RNA-based mechanisms in N. meningitidis. PMID:21045552

  15. Pectoral fin morphology of batoid fishes (Chondrichthyes: Batoidea): explaining phylogenetic variation with geometric morphometrics.

    PubMed

    Franklin, Oliver; Palmer, Colin; Dyke, Gareth

    2014-10-01

    The diverse cartilaginous fish lineage, Batoidea (rays, skates, and allies), sister taxon to sharks, comprises a huge range of morphological diversity which to date remains unquantified and unexplained in terms of evolution or locomotor style. A recent molecular phylogeny has enabled us to confidently assess broadscale aspects of morphology across Batoidea. Geometric morphometrics quantifies the major aspects of shape variation, focusing on the enlarged pectoral fins which characterize batoids, to explore relationships between ancestry, locomotion and habitat. A database of 253 specimens, encompassing 60 of the 72 batoid genera, reveals that the majority of morphological variation across Batoidea is attributable to fin aspect-ratio and the chordwise location of fin apexes. Both aspect-ratio and apex location exhibit significant phylogenetic signal. Standardized independent linear contrast analysis reveals that fin aspect-ratio can predict locomotor style. This study provides the first evidence that low aspect-ratio fins are correlated with undulatory-style locomotion in batoids, whereas high aspect-ratio fins are correlated with oscillatory locomotion. We also show that it is phylogeny that determines locomotor style. In addition, body- and caudal fin-locomotors are shown to exhibit low aspect-ratio fins, whereas a pelagic lifestyle correlates with high aspect-ratio fins. These results emphasize the importance of phylogeny in determining batoid pectoral fin shape, however, interactions with other constraints, most notably locomotor style, are also highlighted as significant.

  16. Musculoskeletal morphology of the pelvis and pelvic fins in the lungfish Protopterus annectens.

    PubMed

    King, Heather M; Hale, Melina E

    2014-04-01

    The West African lungfish (Protopterus annectens) performs benthic, pelvic fin-driven locomotion with gaits common to tetrapods, the sister group of the lungfishes. Features of P. annectens movement are similar to those of modern tetrapods and include use of the distal region of the pelvic fin as a “foot,” use of the fin to lift the body above the substrate and rotation of the fin around the joint with the pelvis. In contrast to these similarities in movement, the pelvic fins of P. annectens are long, slender structures that are superficially very different from tetrapod limbs. Here, we describe the musculoskeletal anatomy of the pelvis and pelvic fins of P. annectens with dissection, magnetic resonance imaging, histology and 3D-reconstruction methods. We found that the pelvis is embedded in the hypaxial muscle by a median rostral and two dorsolateral skeletal projections. The protractor and retractor muscles at the base of the pelvic fin are fan-shaped muscles that cup the femur. The skeletal elements of the fin are serially repeating cartilage cylinders. Along the length of the fin, repeating truncated cones of muscles, the musculus circumradialis pelvici, are separated by connective tissue sheets that connect the skeletal elements to the skin. The simplicity of the protractor and retractor muscles at the base of the fin is surprising, given the complex rotational movement those muscles generate. In contrast, the series of many repeating segmental muscles along the length of the fin is consistent with the dexterity of bending of the distal limb. P. annectens can provide a window into softtissue anatomy and sarcopterygian fish fin function that complements the fossil data from related taxa. This work, combined with previous behavioral examination of P. annectens, illustrates that fin morphologies that do not appear to be capable of walking can accomplish that function, and may inform the interpretation of fossil anatomical evidence.

  17. Finned-Ladder Slow-Wave Circuit for a TWT

    NASA Technical Reports Server (NTRS)

    Wilson, Jeffrey D.; Wintucky, Edwin G.; Kory, Carol L.

    2004-01-01

    A finned-ladder structure has been invented in an effort to improve the design of the slow-wave circuit of a traveling-wave tube (TWT). The point of departure for the design effort was a prototype TWT that contains a ring-plane slow-wave circuit (see Figure 1). The design effort was a response to the observation that despite the high-power capabilities of the ringplane TWT, its requirement for a high supply voltage and its low bandwidth have made it unacceptable for use outside a laboratory setting.

  18. Radio tracking of a fin whale /Balaenoptera physalus/

    NASA Technical Reports Server (NTRS)

    Ray, G. C.; Wartzok, D.; Mitchell, E. D.; Kozicki, V. M.; Maiefski, R.

    1978-01-01

    Tracking of a fin whale tagged with an implantable beacon transmitter (IBT) is described. The IBT, which was fired from a modified 12-gauge shotgun, weighs 517 g and is 70 cm long, including a 46-cm antenna. Data on whale movement and breathing are presented. Contact was lost after 27.8 hours of intermittent tracking, presumably as a result of battery leakage. Potential range and duration of IBT transmission are considered, and the significance of transmitter location and orientation in the whale blubber is considered.

  19. Involvement of the SIN4 global transcriptional regulator in the chromatin structure of Saccharomyces cerevisiae.

    PubMed Central

    Jiang, Y W; Stillman, D J

    1992-01-01

    We have cloned and sequenced the SIN4 gene and determined that SIN4 is identical to TSF3, identified as a negative regulator of GAL1 gene transcription (S. Chen, R.W. West, Jr., S.L. Johnson, H. Gans, and J. Ma, submitted for publication). Yeast strains bearing a sin4 delta null mutation have been constructed and are temperature sensitive for growth and display defects in both negative and positive regulation of transcription. Transcription of the CTS1 gene is reduced in sin4 delta mutants, suggesting that Sin4 functions as a positive transcriptional regulator. Additionally, a Sin4-LexA fusion protein activates transcription from test promoters containing LexA binding sites. The sin4 delta mutant also shows phenotypes common to histone and spt mutants, including suppression of delta insertion mutations in the HIS4 and LYS2 promoters, expression of promoters lacking upstream activation sequence elements, and decreased superhelical density of circular DNA molecules. These results suggest that the sin4 delta mutation may alter the structure of chromatin, and these changes in chromatin structure may affect transcriptional regulation. Images PMID:1406639

  20. Fgf and Sdf-1 pathways interact during zebrafish fin regeneration.

    PubMed

    Bouzaffour, Mohamed; Dufourcq, Pascale; Lecaudey, Virginie; Haas, Petra; Vriz, Sophie

    2009-06-08

    The chemokine stromal cell-derived factor-1 (SDF1) was originally identified as a pre-B cell stimulatory factor but has been recently implicated in several other key steps in differentiation and morphogenesis. In addition, SDF1 as well as FGF signalling pathways have recently been shown to be involved in the control of epimorphic regeneration. In this report, we address the question of a possible interaction between the two signalling pathways during adult fin regeneration in zebrafish. Using a combination of pharmaceutical and genetic tools, we show that during epimorphic regeneration, expression of sdf1, as well as of its cognate receptors, cxcr4a, cxcr4b and cxcr7 are controlled by FGF signalling. We further show that, Sdf1a negatively regulates the expression of fgf20a. Together, these results lead us to propose that: 1) the function of Fgf in blastema formation is, at least in part, relayed by the chemokine Sdf1a, and that 2) Sdf1 exerts negative feedback on the Fgf pathway, which contributes to a transient expression of Fgf20a downstream genes at the beginning of regeneration. However this feedback control can be bypassed since the Sdf1 null mutants regenerate their fin, though slower. Very few mutants for the regeneration process were isolated so far, illustrating the difficulty in identifying genes that are indispensable for regeneration. This observation supports the idea that the regeneration process involves a delicate balance between multiple pathways.

  1. Implication of type 3 deiodinase induction in zebrafish fin regeneration.

    PubMed

    Bouzaffour, Mohamed; Rampon, Christine; Ramaugé, Martine; Courtin, Françoise; Vriz, Sophie

    2010-08-01

    Thyroid hormones are critical determinants of cellular differentiation. We used the zebrafish model to evaluate the involvement of thyroid hormones in regeneration processes after caudal fin amputation. We examined early events following fin amputation, i.e., blastema formation and nerve repair by growth cone formation. Here, we show that the abolition of thyroid gland activity by methimazole treatment had no effect on blastema formation, but slowed growth cone formation of the lateral line. Conversely, the addition of exogenous thyroid hormones enhanced growth cone formation without affecting blastema formation. However, amputation triggered a strong induction in the blastema of type 3 deiodinase mRNA and enzymatic activity, which degrades thyroid hormone (TH). We therefore blocked deiodinase activity with iopanoic acid (IOP) and saw a reduction in blastema formation, suggesting that local degradation of TH is permissive for cell proliferation in the blastema. The effect of IOP on the blastema required endogenous or exogenous TH. Our findings support a model in which local degradation of TH by type 3 deiodinase is permissive for epimorphic regeneration.

  2. Lionfish predators use flared fin displays to initiate cooperative hunting

    PubMed Central

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

    2014-01-01

    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. PMID:24966203

  3. Vitrification of caudal fin explants from zebrafish adult specimens.

    PubMed

    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.

  4. FinFET and UTBB for RF SOI communication systems

    NASA Astrophysics Data System (ADS)

    Raskin, Jean-Pierre

    2016-11-01

    Performance of RF integrated circuit (IC) is directly linked to the analog and high frequency characteristics of the transistors, the quality of the back-end of line process as well as the electromagnetic properties of the substrate. Thanks to the introduction of the trap-rich high-resistivity Silicon-on-Insulator (SOI) substrate on the market, the ICs requirements in term of linearity are fulfilled. Today partially depleted SOI MOSFET is the mainstream technology for RF SOI systems. Future generations of mobile communication systems will require transistors with better high frequency performance at lower power consumption. The advanced MOS transistors in competition are FinFET and Ultra Thin Body and Buried oxide (UTBB) SOI MOSFETs. Both devices have been intensively studied these last years. Most of the reported data concern their digital performance. In this paper, their analog/RF behavior is described and compared. Both show similar characteristics in terms of transconductance, Early voltage, voltage gain, self-heating issue but UTBB outperforms FinFET in terms of cutoff frequencies thanks to their relatively lower fringing parasitic capacitances.

  5. Fgf signalling controls diverse aspects of fin regeneration.

    PubMed

    Shibata, Eri; Yokota, Yuki; Horita, Natsumi; Kudo, Akira; Abe, Gembu; Kawakami, Koichi; Kawakami, Atsushi

    2016-08-15

    Studies have shown that fibroblast growth factor (Fgf) signalling is necessary for appendage regeneration, but its exact function and the ligands involved during regeneration have not yet been elucidated. Here, we performed comprehensive expression analyses and identified fgf20a and fgf3/10a as major Fgf ligands in the wound epidermis and blastema, respectively. To reveal the target cells and processes of Fgf signalling, we performed a transplantation experiment of mesenchymal cells that express the dominant-negative Fgf receptor 1 (dnfgfr1) under control of the heat-shock promoter. This mosaic knockdown analysis suggested that Fgf signalling is directly required for fin ray mesenchyme to form the blastema at the early pre-blastema stage and to activate the regenerative cell proliferation at a later post-blastema stage. These results raised the possibility that the early epidermal Fgf20a and the later blastemal Fgf3/10a could be responsible for these respective processes. We demonstrated by gain-of-function analyses that Fgf20a induces the expression of distal blastema marker junbl, and that Fgf3 promotes blastema cell proliferation. Our study highlights that Fgfs in the wound epidermis and blastema have distinct functions to regulate fin regeneration cooperatively.

  6. Mechanism of tonal noise generation from circular cylinder with spiral fin

    NASA Astrophysics Data System (ADS)

    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.

  7. A Chemical Screen to Identify Novel Inhibitors of Fin Regeneration in Zebrafish

    PubMed Central

    Oppedal, Douglas

    2010-01-01

    Abstract We performed a chemical screen to look for novel inhibitors of zebrafish caudal fin regeneration. In a pilot screen, 520 compounds were tested. Two compounds, budesonide and AGN192403, abrogated fin regeneration. One compound in particular, AGN192403, targets the imidazoline receptor, a pathway not previously linked to fin regeneration. In addition to inhibiting regeneration of the adult fin, AGN192403 also blocked regeneration of the larval fin fold. Finally, the inhibitory effect of AGN192403 on fin regeneration persisted after removal of the drug. These studies demonstrate that chemical screening is feasible in adult zebrafish and that it is a reasonable strategy to use for exploring the biology of regeneration. PMID:20384483

  8. Synchronized swimming: coordination of pelvic and pectoral fins during augmented punting by the freshwater stingray Potamotrygon orbignyi.

    PubMed

    Macesic, Laura J; Mulvaney, Dana; Blevins, Erin L

    2013-06-01

    Benthic animals live at the juncture of fluid and solid environments, an interface that shapes many aspects of their behavior, including their means of locomotion. Aquatic walking and similar substrate-dependent forms of underwater propulsion have evolved multiple times in benthic invertebrate and vertebrate taxa, including batoid elasmobranchs. Skates (Rajidae) use the pelvic fins to punt across the substrate, keeping the pectoral fin disc still. Other batoids combine pelvic fin motions with pectoral fin undulation in augmented punting, but the coordination of these two modes has not been described. In this study of an augmented punter, the freshwater stingray Potamotrygon orbignyi, we demonstrate the synchrony of pelvic and pectoral fin cycles. The punt begins as the pelvic fins, held in an anterior position, are planted into the substrate and used to push the body forward. Meanwhile, a wave of pectoral fin undulation begins, increasing to maximum height just before the cycle's halfway point, when the pelvic fins reach their furthest posterior extension. The pectoral fin wave subsides as the pelvic fins return to their starting position for subsequent punts. Despite definitive links between pectoral and pelvic fin activity, we find no significant relationship between pectoral fin kinematics (frequency, wave height, and wave speed) and punt performance. However, slip calculations indicate that pectoral undulation can produce thrust and augment punting. Pelvic fin kinematics (frequency and duty factor) have significant effects, suggesting that while both sets of fins contribute to thrust generation, the pelvic fins likely determine punt performance.

  9. Flow structure of natural dehumidification over a horizontal finned-tube

    NASA Astrophysics Data System (ADS)

    Hirbodi, Kamran; Yaghoubi, Mahmood

    2016-08-01

    In the present study, structure of water drops formation, growth, coalescence and departure over a horizontal finned-tube during natural dehumidification is investigated experimentally. Starting time of repelling the drops as well as heat transfer rate and the rate of dripping condensates in quasi-steady-state conditions are presented. Furthermore, cold airflow pattern around the horizontal finned-tube is visualized by using smoke generation scheme during natural dehumidification process. The finned-tube has a length of 300 mm, and inner and outer fin diameters, fin thickness and fin spacing are 25.4, 56, 0.4 and 2 mm, respectively. The tests are conducted in an insulated control room with dimensions of 5.8 m × 3 m × 4 m. Ambient air temperature, relative humidity and fin base temperature are selected from 25 to 35 °C, from 40 to 70 % and from 4 to 8 °C, respectively. Observations show that natural condensation from humid air over the test case is completely dropwise. Droplets only form on the edge of the fin and lateral fin surfaces remain almost dry. Dehumidification process over the tested finned-tube is divided into four stages; nucleation, formation, growth and departure of drops. It is also observed that the condensate inundation leaves the tube bottom in the form of droplets. Smoke visualization depicts that humid airflows downward around the cold finned-tube surface without noticeable turbulence and separation in the initial stages of dehumidification process. But the airflow has some disturbances in the intermediate stage and especially during drop departure on the edge of the fins.

  10. Effects of fin clipping on survival and position-holding behavior of brown darters, Etheostoma edwini

    USGS Publications Warehouse

    Champagne, C.E.; Austin, J.D.; Jelks, H.L.; Jordan, F.

    2008-01-01

    Advent of the polymerase chain reaction (PCR) has allowed conservation biologists to use small portions of tissue to obtain genetic material for population genetic and taxonomic study. Fin clips are used extensively in large-sized fishes, but it is unclear how clipping enough fin tissue for genetic analysis will affect survival of smaller fishes such as minnows and darters, which are among the most threatened organisms in North America. We tested for effects of fin clipping on survival and swimming performance of non-threatened Brown Darters (Etheostoma edwini) in order to justify similar tissue collection in co-occurring endangered Okaloosa Darters (E. okaloosae). We collected 48 E. edwini from a small stream in northwest Florida, transported them to the laboratory, and randomly assigned them to one of three experimental groups: control, entire right pectoral fin removed, or rear half of caudal fin removed. Successful amplification of DNA indicated that our fin clips were large enough for genetic analysis using PCR. No mortality occurred during a two-month observation period. Fin regeneration was almost complete and we could not visually distinguish clipped fins from control fins after two months. We then randomly assigned fish into the same three experimental groups, clipped fins, and evaluated their ability to hold position at 20 cm/sec in an experimental flow chamber. Neither fish size nor treatment type affected position-holding behavior. Fin clipping does not adversely affect survival and swimming performance of E. edwini maintained in the laboratory. Additional research on the effects of fin clipping on small-sized fishes should be conducted in the field to evaluate survival under natural conditions. ?? 2008 by the American Society of Ichthyologists and Herpetologists.

  11. Efficient heat-transfer surfaces assembled from partially finned flat-oval tubes

    NASA Astrophysics Data System (ADS)

    Pis'mennyi, E. N.

    2011-04-01

    The state of finned convective heat-transfer surfaces and prospects for using them in power engineering and industry are briefly reviewed. The characteristics of a heat-recovery economizer made of partially finned flat-oval tubes are presented by way of comparing them with design versions employing known types of finned tubes, and the results gained from its operation downstream of a PTVM-30M boiler are given.

  12. Development of a Four-Fin Bio-Inspired UUV: CFD Studies

    DTIC Science & Technology

    2012-09-04

    curvature of the robotic pectoral fins was necessary to achieve precise low-speed maneuverability of UUVs in highly time-varying external force... Robotic Pectoral Fin ,” 2007 IEEE Int. Conf. on Robotics and Automation, Roma, Italy. 9. Geder, J., Ramamurti, R., Palmisano, J., Pruessner, M...UUV) with four actively controlled curvature flapping fins is described. Three dimensional unsteady flow computations past several configuration of

  13. Predicting propulsive forces using distributed sensors in a compliant, high DOF, robotic fin.

    PubMed

    Kahn, Jeff C; Peretz, David J; Tangorra, James L

    2015-05-18

    Engineered robotic fins have adapted principles of propulsion from bony-finned fish, using spatially-varying compliance and complex kinematics to produce and control the fin's propulsive force through time. While methods of force production are well understood, few models exist to predict the propulsive forces of a compliant, high degree of freedom, robotic fin as it moves through fluid. Inspired by evidence that the bluegill sunfish (Lepomis macrochirus) has bending sensation in its pectoral fins, the objective of this study is to understand how sensors distributed within a compliant robotic fin can be used to estimate and predict the fin's propulsive force. A biorobotic model of a bluegill sunfish pectoral fin was instrumented with pressure and bending sensors at multiple locations. Experiments with the robotic fin were executed that varied the swimming gait, flapping frequency, stroke phase, and fin stiffness to understand the forces and sensory measures that occur during swimming. A convolution-based, multi-input-single-output (MISO) model was selected to model and study the relationships between sensory data and propulsive force. Subsets of sensory data were studied to determine which sensor modalities and sensor placement locations resulted in the best force predictions. The propulsive forces of the fin were accurately predicted using the linear MISO model on intrinsic sensory data. Bending sensation was more effective than pressure sensation for predicting propulsive forces, and the importance of bending sensation was consistent with several results in biology and engineering studies. It was important to have a spatial distribution of sensors and multiple sensory modalities in order to predict forces across large changes to dynamics. The relationship between propulsive forces and intrinsic sensory measures is complex, and good models should allow for temporal lags between forces and sensory data, changes to the model within a fin stroke, and changes to the

  14. The Influence of Wall Conductivity of Film Condensation with Integral Fin Tubes

    DTIC Science & Technology

    1993-09-23

    horizontal finned tubes made of copper, aluminum , copper nickel(90/10), and stainless steel(316) was studied using a condenser test rig at both vacuum and...TT (Twisted Tape) and WM (Wire Mesh) are type of Inserts) 81 Figure 5.8 Comparison of Rectangular Shaped Finned Tubes to Previous Data for Aluminum ...Shallow Radiussed Root (SRRT) Finned Tubes of Aluminum and Stainless Steel Materials .. ....... .. 90 Figure 5.17 Comparison of Heat Transfer

  15. Behavioral Context of Blue and Fin Whale Calling for Density Estimation

    DTIC Science & Technology

    2014-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Behavioral context of blue and fin whale calling for...in which we will determine the context-appropriate call production rates for blue and fin whales in the Southern California Bight, with the end goal...of facilitating density estimation from passive acoustic data. OBJECTIVES Before a reliable estimate of blue and fin whale call production rates

  16. Fin-Body Interaction and its Hydrodynamic Benefits in Fish's Steady Swimming

    NASA Astrophysics Data System (ADS)

    Liu, Geng; Ren, Yan; Dong, Haibo; Lauder, George

    2016-11-01

    In many past studies on fish swimming, the hydrodynamics of fish caudal fins were investigated separately. However, fish body inevitably interacts with the caudal fin since the fin flaps in the wake of the body during swimming. In this work, an integrated experimental and computational approach has been used to investigate hydrodynamic performance improvement and the vortex dynamics associated with the fin-body interactions of a jack fish in steady swimming. Realistic 3D jack fish geometry and the undulatory kinematics are reconstructed based on the output of a high-speed photogrammetry system. Hydrodynamic performance and wake structures are simulated by an in-house immersed-boundary-method flow solver. It is found that the body-fin interactions enhance the thrust production of the caudal fin by more than 30% compared to that produced by an isolated caudal fin. Further analysis on the vortex dynamics has shown that the vortices shed from the posterior part of the fish body are captured by the leading edge portion of the caudal fin. This further enhances the strength of the leading-edge vortex attaching to the caudal fin and results in larger thrust production. This work reveals a potential performance enhancement mechanism in fish's steady swimming. This work was supported by NSF CBET-1313217 and ONR MURI N00014-14-1-0533.

  17. Heat transfer, erosion and acid condensation characteristics for novel H-type finned oval tube

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Zhao, X.; Tang, G.

    2015-09-01

    Low efficiency of heat transfer, acid corrosion and erosion of economizers affect the economy and security in coal-fired power plants significantly. The H-type finned oval tube is proposed to alleviate these problems. Based on the H-type finned oval tube, we investigated three novel types of fins, including bleeding dimples, longitudinal vortex generators (LVGs), and compound dimple-LVG. We considered the three aspects together, and obtained the heat transfer, acid condensation rate and erosion loss. The results show that the tube bank with the new structured fins can improve the performance on the three aspects, and the compound dimple-LVG performs the highest comprehensive effect.

  18. Genetic and developmental basis for fin shape variation in African cichlid fishes.

    PubMed

    Navon, Dina; Olearczyk, Nathan; Albertson, R Craig

    2017-01-01

    Adaptive radiations are often characterized by the rapid evolution of traits associated with divergent feeding modes. For example, the evolutionary history of African cichlids is marked by repeated and coordinated shifts in skull, trophic, fin and body shape. Here, we seek to explore the molecular basis for fin shape variation in Lake Malawi cichlids. We first described variation within an F2 mapping population derived by crossing two cichlid species with divergent morphologies including fin shape. We then used this population to genetically map loci that influence variation in this trait. We found that the genotype-phenotype map for fin shape is largely distinct from other morphological characters including body and craniofacial shape. These data suggest that key aspects of fin, body and jaw shape are genetically modular and that the coordinated evolution of these traits in cichlids is more likely due to common selective pressures than to pleiotropy or linkage. We next combined genetic mapping data with population-level genome scans to identify wnt7aa and col1a1 as candidate genes underlying variation in the number of pectoral fin ray elements. Gene expression patterns across species with different fin morphologies and small molecule manipulation of the Wnt pathway during fin development further support the hypothesis that variation at these loci underlies divergence in fin shape between cichlid species. In all, our data provide additional insights into the genetic and molecular mechanisms associated with morphological divergence in this important adaptive radiation.

  19. The evolutionary history of the development of the pelvic fin/hindlimb

    PubMed Central

    Don, Emily K; Currie, Peter D; Cole, Nicholas J

    2013-01-01

    The arms and legs of man are evolutionarily derived from the paired fins of primitive jawed fish. Few evolutionary changes have attracted as much attention as the origin of tetrapod limbs from the paired fins of ancestral fish. The hindlimbs of tetrapods are derived from the pelvic fins of ancestral fish. These evolutionary origins can be seen in the examination of shared gene and protein expression patterns during the development of pelvic fins and tetrapod hindlimbs. The pelvic fins of fish express key limb positioning, limb bud induction and limb outgrowth genes in a similar manner to that seen in hindlimb development of higher vertebrates. We are now at a point where many of the key players in the development of pelvic fins and vertebrate hindlimbs have been identified and we can now readily examine and compare mechanisms between species. This is yielding fascinating insights into how the developmental programme has altered during evolution and how that relates to anatomical change. The role of pelvic fins has also drastically changed over evolutionary history, from playing a minor role during swimming to developing into robust weight-bearing limbs. In addition, the pelvic fins/hindlimbs have been lost repeatedly in diverse species over evolutionary time. Here we review the evolution of pelvic fins and hindlimbs within the context of the changes in anatomical structure and the molecular mechanisms involved. PMID:22913749

  20. Notch regulates blastema proliferation and prevents differentiation during adult zebrafish fin regeneration.

    PubMed

    Münch, Juliane; González-Rajal, Alvaro; de la Pompa, José Luis

    2013-04-01

    Zebrafish have the capacity to regenerate several organs, including the heart and fins. Fin regeneration is epimorphic, involving the formation at the amputation plane of a mass of undifferentiated, proliferating mesenchymal progenitor-like cells, called blastema. This tissue provides all the cell types that form the fin, so that after damage or amputation the fin pattern and structure are fully restored. How blastema cells remain in this progenitor-like state is poorly understood. Here, we show that the Notch pathway plays an essential role during fin regeneration. Notch signalling is activated during blastema formation and remains active throughout the regeneration process. Chemical inhibition or morpholino-mediated knockdown of Notch signalling impairs fin regeneration via decreased proliferation accompanied by reduced expression of Notch target genes in the blastema. Conversely, overexpression of a constitutively active form of the Notch1 receptor (N1ICD) in the regenerating fin leads to increased proliferation and to the expansion of the blastema cell markers msxe and msxb, as well as increased expression of the proliferation regulator aldh1a2. This blastema expansion prevents regenerative fin outgrowth, as indicated by the reduction in differentiating osteoblasts and the inhibition of bone regeneration. We conclude that Notch signalling maintains blastema cells in a plastic, undifferentiated and proliferative state, an essential requirement for fin regeneration.

  1. Mathematical equations for heat conduction in the fins of air-cooled engines

    NASA Technical Reports Server (NTRS)

    Harper, R R; Brown, W B

    1923-01-01

    The problem considered in this report is that of reducing actual geometrical area of fin-cooling surface, which is, of course, not uniform in temperature, to equivalent cooling area at one definite temperature, namely, that prevailing on the cylinder wall at the point of attachment of the fin. This makes it possible to treat all the cooling surface as if it were part of the cylinder wall and 100 per cent effective. The quantities involved in the equations are the geometrical dimensions of the fin, thermal conductivity of the material composing it, and the coefficient of surface heat dissipation between the fin and the air streams.

  2. Testing Momentum Enhancement of Ribbon Fin Based Propulsion Using a Robotic Model With an Adjustable Body

    NASA Astrophysics Data System (ADS)

    English, Ian; Curet, Oscar

    2016-11-01

    Lighthill and Blake's 1990 momentum enhancement theory suggests there is a multiplicative propulsive effect linked to the ratio of body and fin heights in Gymnotiform and Balistiform swimmers, which propel themselves using multi-rayed undulating fins while keeping their bodies mostly rigid. Proof of such a momentum enhancement could have a profound effect on unmanned underwater vehicle design and shed light on the evolutionary advantage to body-fin ratios found in nature, shown as optimal for momentum enhancement in Lighthill and Blake's theory. A robotic ribbon fin with twelve independent fin rays, elastic fin membrane, and a body of adjustable height was developed specifically to experimentally test momentum enhancement. Thrust tests for various body heights were conducted in a recirculating flow tank at different flow speeds and fin flapping frequencies. When comparing thrust at different body heights, flow speeds, and frequencies to a 'no-body' thrust test case at each frequency and flow speed, data indicate there is no momentum enhancement factor due to the presence of a body on top of an undulating fin. This suggests that if there is a benefit to a specific ratio between body and fin height, it is not due to momentum enhancement.

  3. Experimental investigation of wing fin configurations for alleviation of vortex wakes of aircraft

    NASA Technical Reports Server (NTRS)

    Rossow, V. J.

    1978-01-01

    A variety of fin configurations were tested on a model of the Boeing B747 in 40 by 80 foot wind tunnels. The test results confirmed that a reduction in wake rolling moment was brought about by the vortex shed by the fins so that a wide range of designs can be used to achieve wake alleviation. It was also found that the reduction in wake-induced rolling moments was especially sensitive to the location of the smaller fins on the wing and that the penalties in lift and drag can probably be made negligible by proper fin design.

  4. Dma1-dependent degradation of SIN proteins during meiosis in Schizosaccharomyces pombe.

    PubMed

    Krapp, Andrea; Simanis, Viesturs

    2014-07-15

    The Schizosaccharomyces pombe septation initiation network (SIN) is required for cytokinesis during vegetative growth and for spore formation during meiosis. Regulation of the SIN during mitosis has been studied extensively, but less is known about its meiotic regulation. Here, we show that several aspects of SIN regulation differ between mitosis and meiosis. First, the presence of GTP-bound Spg1p is not the main determinant of the timing of Cdc7p and Sid1p association with the spindle pole body (SPB) during meiosis. Second, the localisation dependencies of SIN proteins differ from those in mitotic cells, suggesting a modified functional organisation of the SIN during meiosis. Third, there is stage-specific degradation of SIN components in meiosis; Byr4p is degraded after meiosis I, whereas the degradation of Cdc7p, Cdc11p and Sid4p occurs after the second meiotic division and depends upon the ubiquitin ligase Dma1p. Finally, Dma1p-dependent degradation is not restricted to the SIN, as we show that Dma1p is needed for the degradation of Mcp6p (also known as Hrs1p) during meiosis I. Taken together, these data suggest that stage-specific targeted proteolysis plays an important role in regulating meiotic progression.

  5. Ceramic Technology Project database: September 1990 summary report. [SiC, SiN, whisker-reinforced SiN, ZrO-toughened aluminas, zirconias, joints

    SciTech Connect

    Keyes, B.L.P.

    1992-06-01

    Data generated within the Ceramic Technology Project (CTP) represent a valuable resource for both research and industry. The CTP database was created to provide easy access to this information in electronic and hardcopy forms by using a computerized database and by issuing periodic hardcopy reports on the database contents. This report is the sixth in a series of semiannual database summaries and covers recent additions to the database, including joined brazed specimen test data. It covers 1 SiC, 34 SiN, 10 whisker-reinforced SiN, 2 zirconia-toughened aluminas, 8 zirconias, and 34 joints.

  6. Distinct requirements for Sin3a in perinatal male gonocytes and differentiating spermatogonia.

    PubMed

    Gallagher, Shannon J; Kofman, Amber E; Huszar, Jessica M; Dannenberg, Jan-Hermen; DePinho, Ronald A; Braun, Robert E; Payne, Christopher J

    2013-01-01

    Chromatin modifier Swi-independent 3a (SIN3A), together with associated histone deacetylases, influences gene expression during development and differentiation through a variety of transcription factors in a cell-specific manner. Sin3a is essential for the maintenance of inner cell mass cells of mouse blastocysts, embryonic fibroblasts, and myoblasts, but is not required for the survival of trophectoderm or Sertoli cells. To better understand how this transcriptional regulator modulates cells at different developmental stages within a single lineage, we used conditional gene targeting in mice to ablate Sin3a from perinatal quiescent male gonocytes and from postnatal differentiating spermatogonia. Mitotic germ cells expressing stimulated by retinoic acid gene 8 (Stra8) that lacked Sin3a exhibited increased DNA damage and apoptosis, yet collectively progressed through meiosis and spermiogenesis and generated epididymal sperm at approximately 50% of control levels, sufficient for normal fertility. In contrast, perinatal gonocytes lacking Sin3a underwent rapid depletion that coincided with cell cycle reentry, exhibiting 2.5-fold increased histone H3 phosphorylation upon cycling that suggested a prophase/metaphase block; germ cells were almost entirely absent two weeks after birth, resulting in sterility. Gene expression profiling of neonatal testes containing Sin3a-deleted gonocytes identified upregulated transcripts highly associated with developmental processes and pattern formation, and downregulated transcripts involved in nuclear receptor activity, including Nr4a1 (Nur77). Interestingly, Nr4a1 levels were elevated in testes containing Stra8-expressing, Sin3a-deleted spermatogonia. SIN3A directly binds to the Nr4a1 promoter, and Nr4a1 expression is diminished upon spermatogonial differentiation in vitro. We conclude that within the male germline, Sin3a is required for the mitotic reentry of gonocytes, but is dispensable for the maintenance of differentiating

  7. Direct and social genetic parameters for growth and fin damage traits in Atlantic cod (Gadus morhua)

    PubMed Central

    2014-01-01

    Background The aim of the study was to estimate genetic parameters for direct and social genetic effects (SGE) for growth and welfare traits in farmed Atlantic cod (Gadus morhua). A SGE refers to the effect of an individual’s genes on trait performance of its social partners. In total, 2100 individually tagged juveniles from 100 families at an average age of 222 days post-hatching were used. Each family was separated into three groups of seven fish, and were randomly assigned to 100 experimental tanks, together with fish from two other families. Body weight and length of the first, second and third dorsal fin and the caudal fin measured by digital image analysis were measured at the start of the experiment, after two weeks, and after six weeks. Fin erosion was scored subjectively after six weeks. Variance components estimated using a conventional animal model were compared to those of an animal model including a SGE. Results Heritabilities from the conventional animal model ranged from 0.24 to 0.34 for body weight and 0.05 to 0.80 for fin length. Heritabilities for fin erosion were highest for the first dorsal fin (0.83 ± 0.08, mean ± standard error) and lowest for the third dorsal fin (0.01 ± 0.04). No significant SGE were found for body weight, whereas SGE for fin lengths were significant after two and six weeks. Contributions to the total heritable variance were equal to 21.5% (6.1 ± 2.1) for the direct effect, 33.1% (9.4 ± 3.2) for the direct-social covariance, and 45.4% (12.9 ± 4.1) for the social variance for length of the first dorsal fin. For fin erosion, SGE were only significant for the second and third dorsal fin. Conclusions Including SGE for fin length and fin erosion in the animal model increased the estimated heritable variation. However, estimates of total heritable variances were inaccurate and a larger experiment is needed to accurately quantify total heritable variance. Despite this, our results demonstrate that

  8. A new system for analyzing swim fin propulsion based on human kinematic data.

    PubMed

    Nicolas, Guillaume; Bideau, Benoit; Bideau, Nicolas; Colobert, Briac; Le Guerroue, Gaël; Delamarche, Paul

    2010-07-20

    The use of swim fins has become popular in various water sport activities. While numerous models of swim fin with various innovative shapes have been subjectively designed, the exact influence of the fin characteristics on swimming performance is still much debated, and remains difficult to quantify. To date, the most common approach for evaluating swim fin propulsion is based on the study of "swimmer-fins" as a global system, where physiological and/or biomechanical responses are considered. However, reproducible swimming technique is difficult (or even impossible) to obtain on human body and may lead to discrepancies in data acquired between trials. In this study, we present and validate a new automat called HERMES which enables an evaluation of various swim fins during an adjustable, standardized and reproducible motion. This test bench reliably and accurately reproduces human fin-swimming motions, and gives resulting dynamic measurements at the ankle joint. Seven fins with various geometrical and mechanical characteristics were tested. For each swim fin, ankle force and hydromechanical efficiency (useful mechanical power output divided by mechanical power input delivered by the motors) were calculated. Efficiencies reported in our study were high (close to 70% for some swim fins) over a narrow range of Strouhal number (St) and peaks within the interval 0.2fin kinematics and material (design and mechanical properties) on the wake structure and on efficiency.

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

    NASA Astrophysics Data System (ADS)

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

    2008-04-01

    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.

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

    USGS Publications Warehouse

    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.

  11. The fin de siècle thesis.

    PubMed

    Staley, Richard

    2008-12-01

    This paper examines the relations between John Heilbron's argument that fin de siècle physicists adjusted the image and substance of their discipline to cultural concerns, and Paul Forman's approach to acau-sality in the Weimar period. In addition to their focus on representation rather than truth, adherents of the "descriptionist" epistemologies that Heilbron identified also promoted an emphasis on method, statistical rather than causal explanations, historical understandings of epistemology, and stressed the relations between physics and other disciplines. Their views provide an intellectual context--within the physics discipline--for at least some part of what Forman had described as a capitulation to the hostile social environment expressed in Oswald Spengler's Der Untergang des Abendlandes.

  12. Hyaluronic acid synthesis is required for zebrafish tail fin regeneration

    PubMed Central

    Ouyang, Xiaohu; Panetta, Nicholas J.; Talbott, Maya D.; Payumo, Alexander Y.; Halluin, Caroline; Longaker, Michael T.

    2017-01-01

    Using genome-wide transcriptional profiling and whole-mount expression analyses of zebrafish larvae, we have identified hyaluronan synthase 3 (has3) as an upregulated gene during caudal fin regeneration. has3 expression is induced in the wound epithelium within hours after tail amputation, and its onset and maintenance requires fibroblast growth factor, phosphoinositide 3-kinase, and transforming growth factor-ß signaling. Inhibition of hyaluronic acid (HA) synthesis by the small molecule 4-methylumbelliferone (4-MU) impairs tail regeneration in zebrafish larvae by preventing injury-induced cell proliferation. In addition, 4-MU reduces the expression of genes associated with wound epithelium and blastema function. Treatment with glycogen synthase kinase 3 inhibitors rescues 4-MU-induced defects in cell proliferation and tail regeneration, while restoring a subset of wound epithelium and blastema markers. Our findings demonstrate a role for HA biosynthesis in zebrafish tail regeneration and delineate its epistatic relationships with other regenerative processes. PMID:28207787

  13. Computational nano OPC DFM for LV Fin-type SRAM

    NASA Astrophysics Data System (ADS)

    Kadota, Kazuya

    2016-05-01

    Design For Manufacturing (DFM) where the state-of-the-art nano-devices of the sub-20nm node to a subject, for each of the technology has been intricately sophisticated, comprehensive optimization to predict the performance of the device came become very important. [1] To get effective solutions on these subjects, one of the lithographic key is a nano Optical Proximity Correction (OPC) control with SMO technology, and another is TCAD approach using the most advanced computer simulations. And, it is very important to obtain DFM solutions by integrating both. On the other hand, to meet the needs of low-voltage drive and the characteristic variability reduction, in order to obtain a state-of-the-art device performance, the Fin-type transistors are introduced globally as the mainstream because of wider process control margin. This paper, from the point of view of the sub-20nm node DFM, the simulation are conducted on ArF-imm. technology with SMO in SPT, DPT and QPT on TachyonTM [2], and the guideline of design rules are obtained. Furthermore, the simulated transistor pattern shape are directly migrated into TCAD process flow on HyENEXSSTM [3]. Then calculated I-V characteristics on 6 transistors under the various parameters on TCAD, and finally summarized Static Noise Margin (SNM) of SRAMs. Here, various parameters that determine the performance of SRAMs (Fin width, height, angle, dopant concentrations, electric field strength, work function, drive voltage, and operation speed) are intentionally varied and calculated on the TCAD. This computational method is highly sophisticated DFM technology to predict for the leading-edge nano-devices toward for the sub-20nm nodes era [4] [5] [6] [7] .

  14. Material and structural properties of fin whale (Balaenoptera physalus) Zwischensubstanz.

    PubMed

    Pinto, Sheldon J D; Shadwick, Robert E

    2013-08-01

    The oral anatomy of the fin whale (Balaenoptera physalus) consists of several major structures crucial to its engulfment method of feeding, such as stiff keratinized baleen plates, a large flaccid tongue, and a prominent vomer. One under-documented part of this anatomy is the cream white Zwischensubstanz that holds the baleen plates to the rostrum at their dorsal base. The mechanical and structural properties of Zwischensubstanz play a key role in baleen plate dynamics and, on the grand scale, contribute to baleen whales' filtration efficiency and attainment of large body size. Compression and tensile tests on the Zwischensubstanz sampled from an 18 m fin whale showed that this material unexpectedly exhibits linear isotropic behaviour with Elastic Modulus of 2.56 ± 0.60 MPa and hysteresis of 0.44 ± 0.02 in compression despite apparent unidirectional growth. Acting similar to a soft rubber, the Zwischensubstanz absorbs and dissipates the enormous forces acting on baleen plates during engulfment feeding while maintaining spacing between the plates to maximize filtration efficiency. Microscopic analysis provided images of connective tissue papillae penetrating the base of the Zwischensubstanz and developing within it to emerge as fully formed, keratinized baleen plates. The plates develop from the papillae and a connective tissue sheet within the 5-7 cm deep Zwischensubstanz. The Zwischensubstanz provides a keratin matrix of concentrically oriented fibers around each papilla forming the hard baleen plates and frayed fringes used for filter feeding. During this formation, the Zwischensubstanz remains unchanged and appears to slough away to allow the baleen plate to grow unhindered.

  15. Opsin gene duplication and divergence in ray-finned fish.

    PubMed

    Rennison, Diana J; Owens, Gregory L; Taylor, John S

    2012-03-01

    Opsin gene sequences were first reported in the 1980s. The goal of that research was to test the hypothesis that human opsins were members of a single gene family and that variation in human color vision was mediated by mutations in these genes. While the new data supported both hypotheses, the greatest contribution of this work was, arguably, that it provided the data necessary for PCR-based surveys in a diversity of other species. Such studies, and recent whole genome sequencing projects, have uncovered exceptionally large opsin gene repertoires in ray-finned fishes (taxon, Actinopterygii). Guppies and zebrafish, for example, have 10 visual opsin genes each. Here we review the duplication and divergence events that have generated these gene collections. Phylogenetic analyses revealed that large opsin gene repertories in fish have been generated by gene duplication and divergence events that span the age of the ray-finned fishes. Data from whole genome sequencing projects and from large-insert clones show that tandem duplication is the primary mode of opsin gene family expansion in fishes. In some instances gene conversion between tandem duplicates has obscured evolutionary relationships among genes and generated unique key-site haplotypes. We mapped amino acid substitutions at so-called key-sites onto phylogenies and this exposed many examples of convergence. We found that dN/dS values were higher on the branches of our trees that followed gene duplication than on branches that followed speciation events, suggesting that duplication relaxes constraints on opsin sequence evolution. Though the focus of the review is opsin sequence evolution, we also note that there are few clear connections between opsin gene repertoires and variation in spectral environment, morphological traits, or life history traits.

  16. Quasi-stationary phase change heat transfer on a fin

    NASA Astrophysics Data System (ADS)

    Orzechowski, Tadeusz; Stokowiec, Katarzyna

    2016-03-01

    The paper presents heat transfer research basing on a long fin with a circular cross-section. Its basis is welded to the pipe where the hot liquid paraffin, having a temperature of 70°C at the inflow, is pumped. The analyzed element is a recurrent part of a refrigeration's condenser, which is immersed in a paraffin. The temperature of the inflowing liquid is higher than the temperature of the melting process for paraffin, which allows the paraffin to liquify. The temperature at the basis of the rib changes and it is assumed that the heat transfer is quasi-stationary. On this basis the estimation of the mean value of heat transfer coefficient was conducted. The unsteady thermal field of the investigated system was registered with an infrared camera V50 produced by a Polish company Vigo System. This device is equipped with a microbolometric detector with 384 × 288 elements and the single pixel size 25 × 25 μm. Their thermal resolution is lower than 70 mK at a temperature of 30 °C. The camera operates at 7,5 ÷ 14 μm long-wave infrared radiation range. For a typical lens 35 mm the special resolution is 0.7 mrad. The result of the calculations is mean heat transfer coefficient for the considered time series. It is equal to 50 W m -2 K-1 and 47 W m -2 K-1 on the left and right side of the fin, respectively. The distance between the experimental data and the curve approximating the temperature distribution was assessed with the standard deviation, Sd = 0.04 K.

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

    PubMed

    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.

  18. Los plaguicidas y la contaminacion del medio ambiente Venezolano

    USGS Publications Warehouse

    Stickel, L.F.; Stickel, W.H.

    1972-01-01

    RESUMEN DE RECOMENDACIONES Recomendaciones para el Programa de Investigacion: 1. Establecer un sistema de muestreo biologico para detectar los niveles tendencias de los productos quimicos toxicos en un peque?o numero de si tios representativos. 2. Mantener continua vigilancia de la contaminacion ambiental, mediante la seleccion acertadamente dirigida de las zonas afectadas y de las fuentes de contaminacion. 3. Realizar estudios acerca de las poblaciones de animales silvestres, y del exito de los procesos reproductivos de las especies o grupos clayes de animales que se consideran mas gravemente afectados. 4. Preparar recomendaciones para una accion gubernamental de proteccion al hombre, a la fauna silvestre y al medio ambiente. Recomendaciones para la Accion Administrativa: 1. Establecer limites a la tolerancia de los residuos de plaguicidas en los alimentos. Constituye una medida clave para disminuir la contaminacion ambiental. 2. Establecer normas de calidad del agua para las corrientes, represas, la gos y otros cuerpos. Es la segunda medida clave para reducir la contaminacion del ambiente 3. Exigir un tratamiento adecuado de los efluentes industriales, especialmente antes de que se construyan las nuevas plantas. 4. Exigir a los agricultores que en el uso de plaguicidas sigan los consejos tecnicos autorizados y negar a los vendedores el derecho a recomendar productos por su cuenta. 5. Tomar medidas para recoger y eliminar los recipientes y sobrantes de los plaguicidas.

  19. Interaction of Vortex Breakdown with a Flexible Fin and its Control, Phase-3

    DTIC Science & Technology

    2007-11-02

    1 INTERACTION OF VORTEX BREAKDOWN WITH A FLEXIBLE FIN AND ITS CONTROL, PHASE - 3 . Final Report submitted to Dr. Charbel N Raffoul Chief of Aeronautical...NUMBER F61775-01-WE006 5b. GRANT NUMBER 4. TITLE AND SUBTITLE Interaction of Vortex Breakdown with a Flexible Fin and its Control, Phase - 3 5c. PROGRAM

  20. Mediterranean Fin Whales (Balaenoptera physalus) Threatened by Dolphin MorbilliVirus

    PubMed Central

    Centelleghe, Cinzia; Beffagna, Giorgia; Povinelli, Michele; Terracciano, Giuliana; Cocumelli, Cristiano; Pintore, Antonio; Denurra, Daniele; Casalone, Cristina; Pautasso, Alessandra; Di Francesco, Cristina Esmeralda; Di Guardo, Giovanni

    2016-01-01

    During 2011–2013, dolphin morbillivirus was molecularly identified in 4 stranded fin whales from the Mediterranean Sea. Nucleoprotein, phosphoprotein, and hemagglutinin gene sequences of the identified strain were highly homologous with those of a morbillivirus that caused a 2006–2007 epidemic in the Mediterranean. Dolphin morbillivirus represents a serious threat for fin whales. PMID:26812485

  1. Fin-efficiency calculation for condensation in the presence of noncondensable gases

    NASA Astrophysics Data System (ADS)

    Panchal, C. B.

    Plate-fin heat exchangers are being considered for many condenser applications. They are commonly used for the gas-separation process because they can provide a high thermal performance to obtain a low mean-temperature difference, essential for the gas-separation process. Plate-fin heat exchangers are also considered for the heat-pump system using nonazeotropic refrigerant mixtures. The brazed plate-fin condenser was considered to be a leading candidate for the Ocean Thermal Energy Conversion (OTEC) system, where high-performance heat exchangers are essential for maintaining a low mean-temperature difference. Calculation of the fin efficiency is difficult for condensation in the presence of noncondensable gases due to the spatial variation of the interfacial temperature. An analysis was carried out to develop a simplified method to calculate the fin efficiency for condensation of a vapor in the presence of noncondensable gases. The analysis includes the variation in the interfacial temperature along the fin surface. Appropriate assumptions are made to simplify the coupled heat-conduction equation in the fin and the heat/mass fluxes at the interface. The resulting expression for the fin efficiency includes mass-flux parameters, and it is similar to the common expression used for single-phase flow.

  2. Performance analysis of device-level SINS/ACFSS deeply integrated navigation method

    NASA Astrophysics Data System (ADS)

    Zhang, Hao; Qin, Shiqiao; Wang, Xingshu; Jiang, Guangwen; Tan, Wenfeng

    2016-10-01

    The Strap-Down Inertial Navigation System (SINS) is a widely used navigation system. The combination of SINS and the Celestial Navigation System (CNS) is one of the popular measures to constitute the integrated navigation system. A Star Sensor (SS) is used as a precise attitude determination device in CNS. To solve the problem that the star image obtained by SS under dynamic conditions is motion-blurred, the Attitude Correlated Frames (ACF) is presented and the star sensor which works based on ACF approach is named ACFSS. Depending on the ACF approach, a novel device-level SINS/ACFSS deeply integrated navigation method is proposed in this paper. Feedback to the ACF process from the error of the gyro is one of the typical characters of the SINS/CNS deeply integrated navigation method. Herein, simulation results have verified its validity and efficiency in improving the accuracy of gyro and it can be proved that this method is feasible in theory.

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

    PubMed

    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.

  4. [Characteristics of the reparative regeneration of fins in the polypterid fish (Polypteridae, Actinopterygii)].

    PubMed

    Nikiforova, A I; Golichenkov, V A

    2012-01-01

    Epimorphic regeneration of fins was studied in different ray-finned fishes (Actinopterygii), but species representing the phylogenetically basal lineages of the taxon have remained outside the attention of researchers. Information on the regenerative abilities of these groups is important both for understanding the evolutionary origins of the epimorphic regeneration phenomenon and for assessing the universality of regenerative potencies in Actinopterygii. Addressing this problem, we studied for the first time fin regeneration in two members of the archaic family Polypteridae: the ropefish (Erpetoichthys calabaricus) and the Senegal bichir (Polypterus senegalus). Along with the ability to regenerate the bony rays of fins, widespread among Actinopterygii, polypterids show the ability to effectively regenerate the endoskeleton and musculature of their fins. This unusual feature allows us to suggest polypterids as new model organisms for the study of the mechanisms of vertebrate limb regeneration.

  5. The pectoral fin of Tiktaalik roseae and the origin of the tetrapod limb.

    PubMed

    Shubin, Neil H; Daeschler, Edward B; Jenkins, Farish A

    2006-04-06

    Wrists, ankles and digits distinguish tetrapod limbs from fins, but direct evidence on the origin of these features has been unavailable. Here we describe the pectoral appendage of a member of the sister group of tetrapods, Tiktaalik roseae, which is morphologically and functionally transitional between a fin and a limb. The expanded array of distal endochondral bones and synovial joints in the fin of Tiktaalik is similar to the distal limb pattern of basal tetrapods. The fin of Tiktaalik was capable of a range of postures, including a limb-like substrate-supported stance in which the shoulder and elbow were flexed and the distal skeleton extended. The origin of limbs probably involved the elaboration and proliferation of features already present in the fins of fish such as Tiktaalik.

  6. Two-dimensional study of fluid interaction with ray-strengthened fin using immersed boundary method

    NASA Astrophysics Data System (ADS)

    Shoele, Kourosh; Zhu, Qiang

    2010-11-01

    Labriform swimming is a common locomotion mode used by fish in low speed swimming, in which thrust generation is achieved through a combination of flapping and rowing motions of pectoral fins. Pectoral fins of bony fishes usually consist of a soft collagen membrane strengthened by embedded flexible rays, rendering anisotropic flexibility. We developed a fluid-structure interaction model based on immersed boundary method to simulate the kinematics and dynamic performance of an idealized 2D fin by considering the flow within one cross-sectional plane. The rays are represented as springs between target points and actual points along the fin, and the membrane is modeled as inextensible beams between the actual points. Using this model we studied thrust generation and propulsion efficiency of the fin at different combinations of parameters. Effects of Reynolds number, flapping frequency as well as different stiffnesses of the rays are studied.

  7. Protection of Wild Adult Steelhead in Idaho by Adipose Fin Removal: 1984-1985 Annual Report.

    SciTech Connect

    Duke, Rodney C.

    1986-03-01

    All Idaho hatchery-reared steelhead released in the spring of 1985 received an adipose fin clip to differentiate between natural or wild and hatchery, fish, thus allowing for protection of wild fish in the sport harvest. Between 25 September and 14 December 1984, 6,360,542 steelhead trout (Salmo gairdneri) were marked by excising the adipose fin. A total of 10,336 man hours were required to complete the operation. Clip quality and healing, mortality, and adipose fin composition were determined. Quality checks indicated less than 1% of the fish had more than 25% of the fin remaining. Combined mortality at all three hatcheries was 0.3% of the total fish marked. Observed and in vivo test showed complete healing of the excision within 3-4 weeks (observed) and 22 days (in vivo). Bibliographies were compiled for fin regeneration, marked fish survival, hooking mortality, and related catch-and-release studies.

  8. The Saccharomyces cerevisiae Fin1 protein forms cell cycle-specific filaments between spindle pole bodies.

    PubMed

    van Hemert, Martijn J; Lamers, Gerda E M; Klein, Dionne C G; Oosterkamp, Tjerk H; Steensma, H Yde; van Heusden, G Paul H

    2002-04-16

    The FIN1 gene from the yeast Saccharomyces cerevisiae encodes a basic protein with putative coiled-coil regions. Here we show that in large-budded cells a green fluorescent protein-Fin1 fusion protein is visible as a filament between the two spindle pole bodies. In resting cells the protein is undetectable, and in small-budded cells it is localized in the nucleus. During late mitosis it localizes on the spindle pole bodies. Filaments of cyano fluorescent protein-tagged Fin1 colocalize with filaments of green fluorescent protein-tagged Tub1 only in large-budded cells. By electron and atomic force microscopy we showed that purified recombinant Fin1p self-assembles into filaments with a diameter of approximately 10 nm. Our results indicate that the Fin1 protein forms a cell cycle-specific filament, additional to the microtubules, between the spindle pole bodies of dividing yeast cells.

  9. The Saccharomyces cerevisiae Fin1 protein forms cell cycle-specific filaments between spindle pole bodies

    PubMed Central

    van Hemert, Martijn J.; Lamers, Gerda E. M.; Klein, Dionne C. G.; Oosterkamp, Tjerk H.; Steensma, H. Yde; van Heusden, G. Paul H.

    2002-01-01

    The FIN1 gene from the yeast Saccharomyces cerevisiae encodes a basic protein with putative coiled-coil regions. Here we show that in large-budded cells a green fluorescent protein-Fin1 fusion protein is visible as a filament between the two spindle pole bodies. In resting cells the protein is undetectable, and in small-budded cells it is localized in the nucleus. During late mitosis it localizes on the spindle pole bodies. Filaments of cyano fluorescent protein-tagged Fin1 colocalize with filaments of green fluorescent protein-tagged Tub1 only in large-budded cells. By electron and atomic force microscopy we showed that purified recombinant Fin1p self-assembles into filaments with a diameter of ≈10 nm. Our results indicate that the Fin1 protein forms a cell cycle-specific filament, additional to the microtubules, between the spindle pole bodies of dividing yeast cells. PMID:11929974

  10. Sin(x)**2 + cos(x)**2 = 1. [programming identities using comparative combinatorial substitutions

    NASA Technical Reports Server (NTRS)

    Stoutemyer, D. R.

    1977-01-01

    Attempts to achieve tasteful automatic employment of the identities sin sq x + cos sq x = 1 and cos sq h x -sin sq h x = 1 in a manner which truly minimizes the complexity of the resulting expression are described. The disappointments of trigonometric reduction, trigonometric expansion, pattern matching, Poisson series, and Demoivre's theorem are related. The advantages of using the method of comparative combinatorial substitutions are illustrated.

  11. People Who Have Committed a Certain Sin Ought to Be Dead

    ERIC Educational Resources Information Center

    Leenaars, Antoon A.

    2006-01-01

    People who have committed a certain sin ought to be dead; I am a person who has committed that sin; therefore, I ought to be dead. Thus is the logic of a suicidal mind. Lester, Szaz, and others argue the "sinner" should always be allowed to kill him/herself. Shneidman, Leenaars and others do not agree. Once one knows the suicidal mind, it is easy…

  12. Pits, a protein interacting with Ttk69 and Sin3A, has links to histone deacetylation

    PubMed Central

    Liaw, Gwo-Jen

    2016-01-01

    Histone deacetylation plays an important role in transcriptional repression. Previous results showed that the genetic interaction between ttk and rpd3, which encodes a class I histone deacetylase, is required for tll repression. This study investigated the molecular mechanism by which Ttk69 recruits Rpd3. Using yeast two-hybrid screening and datamining, one novel protein was found that weakly interacts with Ttk69 and Sin3A, designated as Protein interacting with Ttk69 and Sin3A (Pits). Pits protein expressed in the early stages of embryos and bound to the region of the tor response element in vivo. Expanded tll expression patterns were observed in embryos lacking maternal pits activity and the expansion was not widened by reducing either maternal ttk or sin3A activity. However, in embryos with simultaneously reduced maternal pits and sin3A activities or maternal pits, sin3A and ttk activities, the proportions of the embryos with expanded tll expression were significantly increased. These results indicate that all three gene activities are involved in tll repression. Level of histone H3 acetylation in the tll proximal region was found to be elevated in embryo with reduced these three gene activities. In conclusion, Ttk69 causes the histone deacetylation-mediated repression of tll via the interaction of Pits and Sin3A. PMID:27622813

  13. Pits, a protein interacting with Ttk69 and Sin3A, has links to histone deacetylation.

    PubMed

    Liaw, Gwo-Jen

    2016-09-13

    Histone deacetylation plays an important role in transcriptional repression. Previous results showed that the genetic interaction between ttk and rpd3, which encodes a class I histone deacetylase, is required for tll repression. This study investigated the molecular mechanism by which Ttk69 recruits Rpd3. Using yeast two-hybrid screening and datamining, one novel protein was found that weakly interacts with Ttk69 and Sin3A, designated as Protein interacting with Ttk69 and Sin3A (Pits). Pits protein expressed in the early stages of embryos and bound to the region of the tor response element in vivo. Expanded tll expression patterns were observed in embryos lacking maternal pits activity and the expansion was not widened by reducing either maternal ttk or sin3A activity. However, in embryos with simultaneously reduced maternal pits and sin3A activities or maternal pits, sin3A and ttk activities, the proportions of the embryos with expanded tll expression were significantly increased. These results indicate that all three gene activities are involved in tll repression. Level of histone H3 acetylation in the tll proximal region was found to be elevated in embryo with reduced these three gene activities. In conclusion, Ttk69 causes the histone deacetylation-mediated repression of tll via the interaction of Pits and Sin3A.

  14. Widespread Collaboration of Isw2 and Sin3-Rpd3 Chromatin Remodeling Complexes in Transcriptional Repression

    PubMed Central

    Fazzio, Thomas G.; Kooperberg, Charles; Goldmark, Jesse P.; Neal, Cassandra; Basom, Ryan; Delrow, Jeffrey; Tsukiyama, Toshio

    2001-01-01

    The yeast Isw2 chromatin remodeling complex functions in parallel with the Sin3-Rpd3 histone deacetylase complex to repress early meiotic genes upon recruitment by Ume6p. For many of these genes, the effect of an isw2 mutation is partially masked by a functional Sin3-Rpd3 complex. To identify the full range of genes repressed or activated by these factors and uncover hidden targets of Isw2-dependent regulation, we performed full genome expression analyses using cDNA microarrays. We find that the Isw2 complex functions mainly in repression of transcription in a parallel pathway with the Sin3-Rpd3 complex. In addition to Ume6 target genes, we find that many Ume6-independent genes are derepressed in mutants lacking functional Isw2 and Sin3-Rpd3 complexes. Conversely, we find that ume6 mutants, but not isw2 sin3 or isw2 rpd3 double mutants, have reduced fidelity of mitotic chromosome segregation, suggesting that one or more functions of Ume6p are independent of Sin3-Rpd3 and Isw2 complexes. Chromatin structure analyses of two nonmeiotic genes reveals increased DNase I sensitivity within their regulatory regions in an isw2 mutant, as seen previously for one meiotic locus. These data suggest that the Isw2 complex functions at Ume6-dependent and -independent loci to create DNase I-inaccessible chromatin structure by regulating the positioning or placement of nucleosomes. PMID:11533234

  15. AUV Positioning Method Based on Tightly Coupled SINS/LBL for Underwater Acoustic Multipath Propagation.

    PubMed

    Zhang, Tao; Shi, Hongfei; Chen, Liping; Li, Yao; Tong, Jinwu

    2016-03-11

    This paper researches an AUV (Autonomous Underwater Vehicle) positioning method based on SINS (Strapdown Inertial Navigation System)/LBL (Long Base Line) tightly coupled algorithm. This algorithm mainly includes SINS-assisted searching method of optimum slant-range of underwater acoustic propagation multipath, SINS/LBL tightly coupled model and multi-sensor information fusion algorithm. Fuzzy correlation peak problem of underwater LBL acoustic propagation multipath could be solved based on SINS positional information, thus improving LBL positional accuracy. Moreover, introduction of SINS-centered LBL locating information could compensate accumulative AUV position error effectively and regularly. Compared to loosely coupled algorithm, this tightly coupled algorithm can still provide accurate location information when there are fewer than four available hydrophones (or within the signal receiving range). Therefore, effective positional calibration area of tightly coupled system based on LBL array is wider and has higher reliability and fault tolerance than loosely coupled. It is more applicable to AUV positioning based on SINS/LBL.

  16. FEM simulation for cold press forging forming of the round-fin heat sink

    NASA Astrophysics Data System (ADS)

    Wang, Kesheng; Han, Yu; Zhang, Haiyan; Zhang, Lihan

    2013-05-01

    In this paper, the finite element method is used to investigate the forming process of cold press forging for the round-fin heat sink in the automotive lighting. A series of simulations on the round-fin heat sink forming using the program DEFORM were carried out. The blank thickness and friction coefficient on the formation of round-fin were studied, and the tooling structure with counterpressure on the heat sink formation was also investigated. The results show that the blank thickness is very good for the round-fin formation, and the thicker the blank is, the better the round-fin can be formed; and also When both the punch-blank interface and the die-blank interface have the same value of friction factor, the larger value of friction factor is in favor of round-fin forming, the further investigation reveals that the friction at the punch-blank interface has more significant effect on preventing the initiation of flow-through compared with the friction at the die-blank interface, which implies that the punch-blank interface has more significant effect on the material flow in the formation of round-fin. Meanwhile, The tooling structure with counterpressure is helpful to the formation of round-fin heat sink, which not only ensures the height of each round-fin on the heat sink is uniform but also retards the initiation of flow-through on the reverse side of round-fin. In addition, the experiments of press forging process were conducted to validate the finite element analysis, and the simulation results are in good agreement with the experimental data.

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

    NASA Astrophysics Data System (ADS)

    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.

  18. Specific requirement of the chromatin modifier mSin3B in cell cycle exit and cellular differentiation.

    PubMed

    David, Gregory; Grandinetti, Kathryn B; Finnerty, Patricia M; Simpson, Natalie; Chu, Gerald C; Depinho, Ronald A

    2008-03-18

    The Sin3-histone deacetylase (HDAC) corepressor complex is conserved from yeast to humans. Mammals possess two highly related Sin3 proteins, mSin3A and mSin3B, which serve as scaffolds tethering HDAC enzymatic activity, and numerous sequence-specific transcription factors to enable local chromatin regulation at specific gene targets. Despite broad overlapping expression of mSin3A and mSin3B, mSin3A is cell-essential and vital for early embryonic development. Here, genetic disruption of mSin3B reveals a very different phenotype characterized by the survival of cultured cells and lethality at late stages of embryonic development with defective differentiation of multiple lineages-phenotypes that are strikingly reminiscent of those associated with loss of retinoblastoma family members or E2F transcriptional repressors. Additionally, we observe that, whereas mSin3B(-/-) cells cycle normally under standard growth conditions, they show an impaired ability to exit the cell cycle with limiting growth factors. Correspondingly, mSin3B interacts physically with the promoters of known E2F target genes, and its deficiency is associated with derepression of these gene targets in vivo. Together, these results reveal a critical role for mSin3B in the control of cell cycle exit and terminal differentiation in mammals and establish contrasting roles for the mSin3 proteins in the growth and development of specific lineages.

  19. Opposite side jet charge tagging and measurement of CP asymmetry parameter $\\sin_{2\\beta}$ at D0

    SciTech Connect

    Zhang, Xiaojian

    2004-01-01

    This dissertation describes the first CP asymmetry parameter sin(2β) measurement by the DO collaboration, sing the opposite side jet charge tagging algorithm in determining B-flavor. The time integrated measurement yields sin(2β) = 0.82 ± 1.80, and the time dependent measurement gives sin(2β) = 1.80 ± 1.15.

  20. Synthesis of FinP RNA by plasmids F and pSLT is regulated by DNA adenine methylation.

    PubMed Central

    Torreblanca, J; Marqués, S; Casadesús, J

    1999-01-01

    DNA adenine methylase mutants of Salmonella typhimurium contain reduced amounts of FinP, an antisense RNA encoded by the virulence plasmid pSLT. Lowered FinP levels are detected in both Dam- FinO+ and Dam- FinO- backgrounds, suggesting that Dam methylation regulates FinP production rather than FinP half-life. Reduced amounts of F-encoded FinP RNA are likewise found in Dam- mutants of Escherichia coli. A consequence of FinP RNA scarcity in the absence of DNA adenine methylation is that Dam- mutants of both S. typhimurium and E. coli show elevated levels of F plasmid transfer. Inhibition of F fertility by the S. typhimurium virulence plasmid is also impaired in a Dam- background. PMID:10408954

  1. Simulation model finned water-air-coil withoutcondensation

    SciTech Connect

    Wetter, Michael

    1999-01-01

    A simple simulation model of a finned water-to- air coil without condensation is presented. The model belongs to a collection of simulation models that allows eficient computer simulation of heating, ventilation, and air-conditioning (HVAC) systems. The main emphasis of the models is short computation time and use of input data that are known in the design process of an HVAC system. The target of the models is to describe the behavior of HVAC components in the part load operation mode, which is becoming increasingly important for energy efficient HVAC systems. The models are intended to be used for yearly energy calculation or load calculation with time steps of about 10 minutes or larger. Short-time dynamic effects, which are of interest for different aspects of control performance, are neglected. The part load behavior of the coil is expressed in terms of the nominal condition and the dimensionless variation of the heat transfer with change of mass flow and temperature on the water side and the air side. The effectiveness- NTU relations are used to parametrize the convective heat transfer at nominal conditions and to compute the part load conditions. Geometrical data for the coil are not required, The calculation of the convective heat transfer coefficients at nominal conditions is based on the ratio of the air side heat transfer coefficients multiplied by the fin eficiency and divided by the water side heat transfer coefficient. In this approach, the only geometrical information required are the cross section areas, which are needed to calculate the~uid velocities. The formulas for estimating this ratio are presented. For simplicity the model ignores condensation. The model is static and uses only explicit equations. The explicit formulation ensures short computation time and numerical stability. This allows using the model with sophisticated engineering methods such as automatic system optimization. The paper fully outlines the algorithm description and its

  2. Calling behavior of blue and fin whales off California

    NASA Astrophysics Data System (ADS)

    Oleson, Erin Marie

    Passive acoustic monitoring is an effective means for evaluating cetacean presence in remote regions and over long time periods, and may become an important component of cetacean abundance surveys. To use passive acoustic recordings for abundance estimation, an understanding of the behavioral ecology of cetacean calling is crucial. In this dissertation, I develop a better understanding of how blue (Balaenoptera musculus) and fin (B. physalus ) whales use sound with the goal of evaluating passive acoustic techniques for studying their populations. Both blue and fin whales produce several different call types, though the behavioral and environmental context of these calls have not been widely investigated. To better understand how calling is used by these whales off California I have employed both new technologies and traditional techniques, including acoustic recording tags, continuous long-term autonomous acoustic recordings, and simultaneous shipboard acoustic and visual surveys. The outcome of these investigations has led to several conclusions. The production of blue whale calls varies with sex, behavior, season, location, and time of day. Each blue whale call type has a distinct behavioral context, including a male-only bias in the production of song, a call type thought to function in reproduction, and the production of some calls by both sexes. Long-term acoustic records, when interpreted using all call types, provide a more accurate measure of the local seasonal presence of whales, and how they use the region annually, seasonally and daily. The relative occurrence of different call types may indicate prime foraging habitat and the presence of different segments of the population. The proportion of animals heard calling changes seasonally and geographically relative to the number seen, indicating the calibration of acoustic and visual surveys is complex and requires further study on the motivations behind call production and the behavior of calling whales

  3. Escaping Flatland: three-dimensional kinematics and hydrodynamics of median fins in fishes.

    PubMed

    Tytell, Eric D; Standen, Emily M; Lauder, George V

    2008-01-01

    Fish swimming has often been simplified into the motions of a two-dimensional slice through the horizontal midline, as though fishes live in a flat world devoid of a third dimension. While fish bodies do undulate primarily horizontally, this motion has important three-dimensional components, and fish fins can move in a complex three-dimensional manner. Recent results suggest that an understanding of the three-dimensional body shape and fin motions is vital for explaining the mechanics of swimming, and that two-dimensional representations of fish locomotion are misleading. In this study, we first examine axial swimming from the two-dimensional viewpoint, detailing the limitations of this view. Then we present data on the kinematics and hydrodynamics of the dorsal fin, the anal fin and the caudal fin during steady swimming and maneuvering in brook trout, Salvelinus fontinalis, bluegill sunfish, Lepomis macrochirus, and yellow perch, Perca flavescens. These fishes actively move the dorsal and anal fins during swimming, resulting in curvature along both anterio-posterior and dorso-ventral axes. The momentum imparted to the fluid by these fins comprises a substantial portion of total swimming force, adding to thrust and contributing to roll stability. While swimming, the caudal fin also actively curves dorso-ventrally, producing vortices separately from both its upper and lower lobes. This functional separation of the lobes may allow additional control of three-dimensional orientation, but probably reduces swimming efficiency. In contrast, fish may boost the caudal fin's efficiency by taking advantage of the flow from the dorsal and anal fins as it interacts with the flow around the caudal fin itself. During maneuvering, fish readily use their fins outside of the normal planes of motion. For example, the dorsal fin can flick laterally, orienting its surface perpendicular to the body, to help in turning and braking. These data demonstrate that, while fish do move

  4. Propulsion efficiency of bodies appended with multiple flapping fins: When more is less

    NASA Astrophysics Data System (ADS)

    Bandyopadhyay, Promode R.; Leinhos, Henry A.

    2013-04-01

    Underwater animals propel themselves by flapping their pectoral and caudal fins in a narrow range of frequencies, given by Strouhal number St, to produce transitional vortex jets (St is generally expressed non-dimensionally as the product of flapping frequency and stroke (arc) length divided by forward speed). The organized nature of the selection of St and of the vortex jet is thought to maximize hydrodynamic efficiency, although the exact mechanism is not known. Our recent Stuart-Landau equation models, which have self-regulation properties, indicate that the fin and its jet vortices couple. Temporal maps of forces in single isolated fins show a bimodal behavior in certain ranges of the transitional Reynolds number; this behavior bears resemblance to neural bifurcation properties that owe their origin to the self-regulation mechanism. In view of our theoretical and biorobotic evidence of self-regulation in single flapping fins, we explore if this property is altered in a fin-appended body, the goal being to understand how the narrow selection of St, self-regulation, and maximization of hydrodynamic efficiency are related. Swimming vehicles of 1-m scale have been built where a rigid cylindrical body is appended with six flapping fins, three at each end. The fins are rigid, have a rounded leading edge and a laminar section (NACA 0012), and are hinged at one end. The planform is an abstracted version of the penguin wing; it has low aspect ratio and a chord Reynolds number that varies in the transitional range from 10 000 to 60 000. The fin geometry, Reynolds number range, and the nonflexible nature of the main body are in common with those in penguins, and the length and displacement volume are similar to those of sharks. The maximum hydrodynamic efficiency of the fin-appended body (0.40) is lower than that of the single fin (0.57), but is close to that of a fish using several fins. The propulsion density (kW/m3 of displacement volume) of the fin-appended cylinder

  5. First-principles study on the structural, elastic and electronic properties of Ti2SiN under high pressure

    NASA Astrophysics Data System (ADS)

    Li, Hui; Wang, Zhenjun; Sun, Guodong; Yu, Pengfei; Zhang, Wenxue

    2016-07-01

    The structural, elastic and electronic properties of Ti2SiN under pressure range of 0-50 GPa have been systemically investigated by first-principles calculations. It is found that both Poisson's ratio and shear anisotropy factor of Ti2SiN increase with pressure, and Ti2SiN is elastic anisotropic. The DOS and Mulliken population analysis have been explored, which indicts that Ti2SiN is metallic-covalent-ionic in nature. The present calculations may contribute preliminary results and a better understanding of Ti2SiN for its applications under high pressure environments.

  6. Evolution of Venomous Cartilaginous and Ray-Finned Fishes.

    PubMed

    Smith, W Leo; Stern, Jennifer H; Girard, Matthew G; Davis, Matthew P

    2016-11-01

    Venom and its associated delivery systems have evolved in numerous animal groups ranging from jellyfishes to spiders, lizards, shrews, and the male platypus. Building off new data and previously published anatomical and molecular studies, we explore the evolution of and variation within venomous fishes. We show the results of the first multi-locus, ordinal-level phylogenetic analysis of cartilaginous (Chondrichthyes) and ray-finned (Actinopterygii) fishes that hypothesizes 18 independent evolutions of this specialization. Ancestral-states reconstruction indicates that among the 2386-2962 extant venomous fishes, envenomed structures have evolved four times in cartilaginous fishes, once in eels (Anguilliformes), once in catfishes (Siluriformes), and 12 times in spiny-rayed fishes (Acanthomorpha). From our anatomical studies and phylogenetic reconstruction, we show that dorsal spines are the most common envenomed structures (∼95% of venomous fish species and 15 independent evolutions). In addition to envenomed spines, fishes have also evolved venomous fangs (2% of venomous fish species, two independent evolutions), cleithral spines (2% of venomous fish species, one independent evolution), and opercular or subopercular spines (1% of venomous fish species, three independent evolutions).

  7. Morphometric Characteristics and Fin Dimorphism between Male and Female on the Marine Medaka, Oryzias dancena

    PubMed Central

    Im, Jae Hyun; Gil, Hyun Woo; Lee, Tae Ho; Kong, Hee Jeong; Ahn, Cheol Min; Kim, Bong Seok; Kim, Dong Soo; Zhang, Chang Ik; Park, In-Seok

    2016-01-01

    ABSTRACT Sexual dimorphism is the most conspicuous difference between the sexes. This study examines possible sexual dimorphism and the relative growth patterns of morphometric characteristics in the marine medaka, Oryzias dancena for their potential to help differentiate between males and females of this species. The von Bertalanffy growth parameters estimated by a non-linear regression method were L∞=30.2 mm, K=3.22/year, and τ0=-0.05. All 18 characteristics measured showed a difference between males and females from 70 days after hatching. Each of these characteristics were significantly different between sexes (ANCOVA, P<0.05), and the ratio of standard length between sexes showed that males were larger than females for all five morphometric measurements. Fin length measurements were taken for 21 distances of anal fin and 7 distances of dorsal fin between landmarks. There were all differences for all dorsal fin rays between the males and the females and there is significant difference in 70 days after their hatch when the sexual dimorphism is presented. The significant difference (P<0.05) in fin ray for male and female was more greatly seen as they grow. Male marine medaka showed more rapid growth than females, with longer length, dorsal fins and anal fins. Differences in these characteristics will be useful during experiments when it is necessary to differentiate between sexes of marine medaka. PMID:28144638

  8. A shift in anterior–posterior positional information underlies the fin-to-limb evolution

    PubMed Central

    Onimaru, Koh; Kuraku, Shigehiro; Takagi, Wataru; Hyodo, Susumu; Sharpe, James; Tanaka, Mikiko

    2015-01-01

    The pectoral fins of ancestral fishes had multiple proximal elements connected to their pectoral girdles. During the fin-to-limb transition, anterior proximal elements were lost and only the most posterior one remained as the humerus. Thus, we hypothesised that an evolutionary alteration occurred in the anterior–posterior (AP) patterning system of limb buds. In this study, we examined the pectoral fin development of catshark (Scyliorhinus canicula) and revealed that the AP positional values in fin buds are shifted more posteriorly than mouse limb buds. Furthermore, examination of Gli3 function and regulation shows that catshark fins lack a specific AP patterning mechanism, which restricts its expression to an anterior domain in tetrapods. Finally, experimental perturbation of AP patterning in catshark fin buds results in an expansion of posterior values and loss of anterior skeletal elements. Together, these results suggest that a key genetic event of the fin-to-limb transformation was alteration of the AP patterning network. DOI: http://dx.doi.org/10.7554/eLife.07048.001 PMID:26283004

  9. Inhibition of caudal fin regeneration in Corydoras aeneus by lithium chloride.

    PubMed

    Zarnescu, Otilia; Stavri, Simona; Moldovan, Lucia

    2013-03-01

    In the present study we examined the effects of lithium chloride on the Corydoras aeneus caudal fin regeneration. After caudal fin amputation, the fish were exposed 3h daily to 35 mM lithium chloride for 9 days. The effects of lithium chloride treatment were evaluated by analyzing the caudal fin structure at 3, 6 and 9 days after amputation. Comparison of normal and LiCl treated fish clearly shows that regeneration of amputated caudal fins was inhibited or delayed after lithium treatment. By the third day after amputation (dpa) either no epidermal cap or blastema ever formed or the epidermal cap had an abnormal morphology in lithium treated fish. By the 3 and 6 dpa no lepidotrichial matrix deposition was observed in the lithium treated fish compared to control fish. Unlike the control fish that completely regenerate their caudal fins after 9 dpa and have fully mineralized lepidotrichia, lithium treated fish have small blastema. In some treated fish, small amounts of new lepidotrichial matrix were observed at this time, in some fin rays. Ultrastructural observations have shown differences between control and lithium treated fish. Thus, in the lithium treated fish we observed expanded intercellular spaces between epidermal cells and many apoptotic cells. Results of this study suggest the use of this model in elucidating the molecular mechanisms that are responsible for regeneration of complex structures such as fish fins.

  10. A novel trapezoid fin pattern applicable for air-cooled heat sink

    NASA Astrophysics Data System (ADS)

    Chen, Chien-Hung; Wang, Chi-Chuan

    2015-11-01

    The present study proposed a novel step or trapezoid surface design applicable to air-cooled heat sink under cross flow condition. A total of five heat sinks were made and tested, and the corresponding fin patterns are (a) plate fin; (b) step fin (step 1/3, 3 steps); (c) 2-step fin (step 1/2, 2 steps); (d) trapezoid fin (trap 1/3, cutting 1/3 length from the rear end) and (e) trapezoid fin (trap 1/2, cutting 1/2 length from the rear end). The design is based on the heat transfer augmentation via (1) longer perimeter of entrance region and (2) larger effective temperature difference at the rear part of the heat sink. From the test results, it is found that either step or trapezoid design can provide a higher heat transfer conductance and a lower pressure drop at a specified frontal velocity. The effective conductance of trap 1/3 design exceeds that of plate surface by approximately 38 % at a frontal velocity of 5 m s-1 while retains a lower pressure drop of 20 % with its surface area being reduced by 20.6 %. For comparisons exploiting the overall thermal resistance versus pumping power, the resultant thermal resistance of the proposed trapezoid design 1/3, still reveals a 10 % lower thermal resistance than the plate fin surface at a specified pumping power.

  11. Temperature-Sensitive Mutations That Cause Stage-Specific Defects in Zebrafish Fin Regeneration

    PubMed Central

    Johnson, S. L.; Weston, J. A.

    1995-01-01

    When amputated, the fins of adult zebrafish rapidly regenerate the missing tissue. Fin regeneration proceeds through several stages, including wound healing, establishment of the wound epithelium, recruitment of the blastema from mesenchymal cells underlying the wound epithelium, and differentiation and outgrowth of the regenerate. We screened for temperature-sensitive mutations that affect the regeneration of the fin. Seven mutations were identified, including five that fail to regenerate their fins, one that causes slow growth during regeneration, and one that causes dysmorphic bumps or tumors to develop in the regenerating fin. reg5 mutants fail to regenerate their caudal fins, whereas reg6 mutants develop dysmorphic bumps in their regenerates at the restrictive temperature. Temperature-shift experiments indicate that reg5 and reg6 affect different stages of regeneration. The critical period for reg5 occurs during the early stages of regeneration before or during establishment of the blastema, resulting in defects in subsequent growth of the blastema and failure to differentiate bone-forming cells. The critical period for reg6 occurs after the onset of bone differentiation and during early stages of regenerative outgrowth. Both reg5 and reg6 also show temperature-sensitive defects in embryonic development or in ontogenetic outgrowth of the juvenile fin. PMID:8601496

  12. Morphogen-based simulation model of ray growth and joint patterning during fin development and regeneration.

    PubMed

    Rolland-Lagan, Anne-Gaëlle; Paquette, Mathieu; Tweedle, Valerie; Akimenko, Marie-Andrée

    2012-03-01

    The fact that some organisms are able to regenerate organs of the correct shape and size following amputation is particularly fascinating, but the mechanism by which this occurs remains poorly understood. The zebrafish (Danio rerio) caudal fin has emerged as a model system for the study of bone development and regeneration. The fin comprises 16 to 18 bony rays, each containing multiple joints along its proximodistal axis that give rise to segments. Experimental observations on fin ray growth, regeneration and joint formation have been described, but no unified theory has yet been put forward to explain how growth and joint patterns are controlled. We present a model for the control of fin ray growth during development and regeneration, integrated with a model for joint pattern formation, which is in agreement with published, as well as new, experimental data. We propose that fin ray growth and joint patterning are coordinated through the interaction of three morphogens. When the model is extended to incorporate multiple rays across the fin, it also accounts for how the caudal fin acquires its shape during development, and regains its correct size and shape following amputation.

  13. The Effect of Caudal Fin Shape on the Hydrodynamics of Swimming

    NASA Astrophysics Data System (ADS)

    Daghooghi, Mohsen; Borazjani, Iman

    2011-11-01

    The caudal fin is thought to be the main thrust generator in body/caudal fin swimmers because the largest undulations occur at the caudal fin. The shape of the fin could possibly be one of the most important factors in thrust generation for such swimmers. However, investigating this experimentally is quite challenging due to the issues in controlling and measuring forces on different appendages of live fish. We can investigate the effect of caudal fin shape through controlled numerical simulations. We construct virtual swimmers with different caudal fin shapes but with the same projected area. We attach trapezoidal and heterocercal shapes of caudal fins (e.g. observed in trouts and sharks, respectively) to a mackerel body and test these swimmers beside the original mackerel with a hemocercal tail. We prescribe the same carangiform kinematics to all virtual swimmers and carry out self-propelled simulations under similar conditions, i.e., the undulations are prescribed while motion of the center of mass is calculated. The simulations are continued until the quasi-steady state is reached, in which the swimmers are compared in terms of different performance measures. This work was partly supported by the Center for Computational Research at the University at Buffalo.

  14. Fluid Dynamics of Biomimetic Pectoral Fin Propulsion Using Immersed Boundary Method

    PubMed Central

    Li, Ningyu; Su, Yumin

    2016-01-01

    Numerical simulations are carried out to study the fluid dynamics of a complex-shaped low-aspect-ratio pectoral fin that performs the labriform swimming. Simulations of flow around the fin are achieved by a developed immersed boundary (IB) method, in which we have proposed an efficient local flow reconstruction algorithm with enough robustness and a new numerical strategy with excellent adaptability to deal with complex moving boundaries involved in bionic flow simulations. The prescribed fin kinematics in each period consists of the power stroke and the recovery stroke, and the simulations indicate that the former is mainly used to provide the thrust while the latter is mainly used to provide the lift. The fin wake is dominated by a three-dimensional dual-ring vortex wake structure where the partial power-stroke vortex ring is linked to the recovery-stroke ring vertically. Moreover, the connection of force production with the fin kinematics and vortex dynamics is discussed in detail to explore the propulsion mechanism. We also conduct a parametric study to understand how the vortex topology and hydrodynamic characteristics change with key parameters. The results show that there is an optimal phase angle and Strouhal number for this complicated fin. Furthermore, the implications for the design of a bioinspired pectoral fin are discussed based on the quantitative hydrodynamic analysis. PMID:27478363

  15. Pectoral fins aid in navigation of a complex environment by bluegill sunfish under sensory deprivation conditions.

    PubMed

    Flammang, Brooke E; Lauder, George V

    2013-08-15

    Complex structured environments offer fish advantages as places of refuge and areas of greater potential prey densities, but maneuvering through these environments is a navigational challenge. To successfully navigate complex habitats, fish must have sensory input relaying information about the proximity and size of obstacles. We investigated the role of the pectoral fins as mechanosensors in bluegill sunfish swimming through obstacle courses under different sensory deprivation and flow speed conditions. Sensory deprivation was accomplished by filming in the dark to remove visual input and/or temporarily blocking lateral line input via immersion in cobalt chloride. Fish used their pectoral fins to touch obstacles as they swam slowly past them under all conditions. Loss of visual and/or lateral line sensory input resulted in an increased number of fin taps and shorter tap durations while traversing the course. Propulsive pectoral fin strokes were made in open areas between obstacle posts and fish did not use the pectoral fins to push off or change heading. Bending of the flexible pectoral fin rays may initiate an afferent sensory input, which could be an important part of the proprioceptive feedback system needed to navigate complex environments. This behavioral evidence suggests that it is possible for unspecialized pectoral fins to act in both a sensory and a propulsive capacity.

  16. Aryl hydrocarbon receptor activation impairs extracellular matrix remodeling during zebra fish fin regeneration.

    PubMed

    Andreasen, Eric A; Mathew, Lijoy K; Löhr, Christiane V; Hasson, Rachelle; Tanguay, Robert L

    2007-01-01

    Adult zebra fish completely regenerate their caudal (tail) fin following partial amputation. Exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) inhibits this regenerative process. Proper regulation of transcription, innervation, vascularization, and extracellular matrix (ECM) composition is essential for complete fin regeneration. Previous microarray studies suggest that genes involved in ECM regulation are misexpressed following activation of the aryl hydrocarbon receptor. To investigate whether TCDD blocks regeneration by impairing ECM remodeling, male zebra fish were i.p. injected with 50 ng/g TCDD or vehicle, and caudal fins were amputated. By 3 days postamputation (dpa), the vascular network in the regenerating fin of TCDD-exposed fish was disorganized compared to vehicle-exposed animals. Furthermore, immunohistochemical staining revealed that axonal outgrowth was impacted by TCDD as early as 3 dpa. Histological analysis demonstrated that TCDD exposure leads to an accumulation of collagen at the end of the fin ray just distal to the amputation site by 3 dpa. Mature lepidotrichial-forming cells (fin ray-forming cells) were not observed in the fins of TCDD-treated fish. The capacity to metabolize ECM was also altered by TCDD exposure. Quantitative real-time PCR studies revealed that the aryl hydrocarbon pathway is active and that matrix-remodeling genes are expressed in the regenerate following TCDD exposure.

  17. Fish's Muscles Distortion and Pectoral Fins Propulsion of Lift-Based Mode

    NASA Astrophysics Data System (ADS)

    Yang, S. B.; Han, X. Y.; Qiu, J.

    As a sort of MPF(median and/or paired fin propulsion), pectoral fins propulsion makes fish easier to maneuver than other propulsion, according to the well-established classification scheme proposed by Webb in 1984. Pectoral fins propulsion is classified into oscillatory propulsion, undulatory propulsion and compound propulsion. Pectoral fins oscillatory propulsion, is further ascribable to two modes: drag-based mode and lift-based mode. And fish exhibits strong cruise ability by using lift-based mode. Therefore to robot fish design using pectoral fins lift-based mode will bring a new revolution to resources exploration in blue sea. On the basis of the wave plate theory, a kinematic model of fish’s pectoral fins lift-based mode is established associated with the behaviors of cownose ray (Rhinoptera bonasus) in the present work. In view of the power of fish’s locomotion from muscle distortion, it would be helpful benefit to reveal the mechanism of fish’s locomotion variation dependent on muscles distortion. So this study puts forward the pattern of muscles distortion of pectoral fins according to the character of skeletons and muscles of cownose ray in morphology and simulates the kinematics of lift-based mode using nonlinear analysis software. In the symmetrical fluid field, the model is simulated left-right symmetrically or asymmetrically. The results qualitatively show how muscles distortion determines the performance of fish locomotion. Finally the efficient muscles distortion associated with the preliminary dynamics is induced.

  18. Neural network detected in a presumed vestigial trait: ultrastructure of the salmonid adipose fin.

    PubMed

    Buckland-Nicks, J A; Gillis, M; Reimchen, T E

    2012-02-07

    A wide variety of rudimentary and apparently non-functional traits have persisted over extended evolutionary time. Recent evidence has shown that some of these traits may be maintained as a result of developmental constraints or neutral energetic cost, but for others their true function was not recognized. The adipose fin is small, fleshy, non-rayed and located between the dorsal and caudal fins on eight orders of basal teleosts and has traditionally been regarded as vestigial without clear function. We describe here the ultrastructure of the adipose fin and for the first time, to our knowledge, present evidence of extensive nervous tissue, as well as an unusual subdermal complex of interconnected astrocyte-like cells equipped with primary cilia. The fin contains neither adipose tissue nor fin rays. Many fusiform actinotrichia, comprising dense striated macrofibrils, support the free edge and connect with collagen cables that link the two sides. These results are consistent with a recent hypothesis that the adipose fin may act as a precaudal flow sensor, where its removal can be detrimental to swimming efficiency in turbulent water. Our findings provide insight to the broader themes of function versus constraints in evolutionary biology and may have significance for fisheries science, as the adipose fin is routinely removed from millions of salmonids each year.

  19. The Oldest Actinopterygian Highlights the Cryptic Early History of the Hyperdiverse Ray-Finned Fishes.

    PubMed

    Lu, Jing; Giles, Sam; Friedman, Matt; den Blaauwen, Jan L; Zhu, Min

    2016-06-20

    Osteichthyans comprise two divisions, each containing over 32,000 living species [1]: Sarcopterygii (lobe-finned fishes and tetrapods) and Actinopterygii (ray-finned fishes). Recent discoveries from China highlight the morphological disparity of early sarcopterygians and extend their origin into the late Silurian [2-4]. By contrast, the oldest unambiguous actinopterygians are roughly 30 million years younger, leaving a long temporal gap populated by fragments and rare body fossils of controversial phylogenetic placement [5-10]. Here we reinvestigate the enigmatic osteichthyan Meemannia from the Early Devonian (∼415 million years ago) of China, previously identified as an exceptionally primitive lobe-finned fish [3, 7, 11, 12]. Meemannia combines "cosmine"-like tissues taken as evidence of sarcopterygian affinity with actinopterygian-like skull roof and braincase geometry, including endoskeletal enclosure of the spiracle and a lateral cranial canal. We report comparable histological structures in undoubted ray-finned fishes and conclude that they are general osteichthyan features. Phylogenetic analysis places Meemannia as an early-diverging ray-finned fish, resolving it as the sister lineage of Cheirolepis [13] plus all younger actinopterygians. This brings the first appearance of ray-fins more in line with that of lobe-fins and fills a conspicuous faunal gap in the otherwise diverse late Silurian-earliest Devonian vertebrate faunas of the South China Block [4].

  20. Collagen duplicate genes of bone and cartilage participate during regeneration of zebrafish fin skeleton.

    PubMed

    Duran, I; Csukasi, F; Taylor, S P; Krakow, D; Becerra, J; Bombarely, A; Marí-Beffa, M

    2015-01-01

    The zebrafish fin is widely used as a model for skeleton regeneration. For years, the nature of the fin skeleton has been controversial as its extracellular matrix shows hybrid characteristics of both bone and cartilage. The presence of co-orthologs genes also increases the complexity of these tissues. In this article, we have identified and described the expression of fibrillar collagens in zebrafish fin skeleton. We found that genes coding for types I, II, V, XI and XXVII collagens are duplicated, showing in several cases, different expression domains. We also identified specific genomic features, such as the presence of type XXIV collagen and the absence of type III collagen in the zebrafish genome. Our study showed that actinotrichia-forming cells and osteoblasts synthesize a wide variety of these fibrillar collagens during fin regeneration. An intertrichial domain expressing most of the collagens was located in the transition between the mesenchyme condensations of actinotrichia and lepidotrichia and may determine an important niche associated with fin skeleton morphogenesis. We also confirmed the hybrid nature of the fin exoskeleton and provided a complete description of those fibrillar collagens expressed during the formation of the fin skeleton.

  1. Bichir microRNA repertoire suggests a ray-finned fish affinity of Polypteriforme.

    PubMed

    Yang, Liandong; Zhang, Zhaolei; He, Shunping

    2015-07-25

    The phylogenetic position of Polypteriforme (bichirs) remains elusive, despite extensive research both on morphological and molecular datasets. Unfortunately morphological cladistic analyses and molecular phylogenetic analyses had reached conflicting conclusions, as Polypteriformes were either grouped with lobe-finned fishes (Sarcopterygii) or ray-finned fishes (Actinopterygii), or even classified as their own group, the Brachiopterygii. In this study, we applied a third independent source of datasets, the presence versus absence of microRNAs, to re-investigate the phylogenetic relationship of bichirs. Through deep sequencing of small RNA library, we showed that bichirs should be grouped into ray-finned fishes rather than lobe-finned fishes. Phylogenetic analysis confirmed that bichirs were placed as the most basal member of the ray-finned fishes. Bichirs shared five unique microRNA families with teleostei, which were not found in any other species investigated to date. Bichirs have also retained three of five microRNAs that were previously deemed to be lost exclusively in teleostei. Furthermore, we report more than one hundred novel microRNAs that are unique to bichir. The identification of microRNAs in bichir provides overwhelming evidence for their affinity of ray-finned fishes. The sarcopterygian-like characteristics such as lobed fins, paired ventral lungs, and external gills in juveniles should not be considered as derived traits shared with those of sarcopterygians.

  2. Line profile measurement of advanced-FinFET features by reference metrology

    NASA Astrophysics Data System (ADS)

    Takamasu, Kiyoshi; Iwaki, Yuuki; Takahashi, Satoru; Kawada, Hiroki; Ikota, Masami; Yamaguchi, Atsuko; Lorusso, Gian F.; Horiguchi, Naoto

    2015-03-01

    A novel method of sub-nanometer uncertainty for the line profile measurement using TEM (Transmission Electron Microscope) images is proposed to calibrate CD-SEM (Critical Dimension Scanning Electron Microscope) line width measurement and to standardize line profile measurement through reference metrology. The proposed method has been validated for profile of Si line and photoresist features in our previous investigations. In this article, we apply the methodology to line profile measurements of advanced-FinFET (Fin-shaped Field-Effect Transistor) features. The FinFET features are sliced as thin specimens of 100 nm thickness by FIB (Focused Ion Beam) micro sampling system. Cross-sectional images of the specimens are obtained then by TEM. The profiles of fin, hardmask and dummy gate of FinFET features are evaluated using TEM images. The width of fin, the length of hardmask, and the length of dummy gate of FinFET features are measured and compared to CD-SEM measurement. The TEM results will be used to implement CD-SEM and CD-AFM reference metrology.

  3. Wnt11-R signaling regulates a calcium sensitive EMT event essential for dorsal fin development of Xenopus

    PubMed Central

    Garriock, Robert J.; Krieg, Paul A.

    2007-01-01

    In the frog embryo, a sub-population of trunk neural crest (NC) cells undergoes a dorsal route of migration to contribute to the mesenchyme in the core of the dorsal fin. Here we show that a second population of cells, originally located in the dorsomedial region of the somite, also contributes to the fin mesenchyme. We find that the frog orthologue of Wnt11 (Wnt11-R) is expressed in both the NC and somite cell populations that migrate into the fin matrix. Wnt11-R is expressed prior to migration and persists in the mesenchymal cells after they have distributed throughout the fin. Loss of function studies demonstrate that Wnt11-R activity is required for an epithelial to mesenchymal transformation (EMT) event that precedes migration of cells into the fin matrix. In Wnt11-R depleted embryos, the absence of fin core cells leads to defective dorsal fin development and to collapse of the fin structure. Experiments using small molecule inhibitors indicate that dorsal migration of fin core cells depends on calcium signaling through calcium/calmodulin-dependent kinase II (CaMKII). In Wnt11-R depleted embryos, normal migration of NC cells and dorsal somite cells into the fin and normal fin development can be rescued by stimulation of calcium release. These studies are consistent with a model in which Wnt11-R signaling, via a downstream calcium pathway, regulates fin cell migration and, more generally, indicates a role for non-canonical Wnt signaling in regulation of EMT. PMID:17240368

  4. Oil-flow study of a Space Shuttle orbiter tip-fin controller

    NASA Technical Reports Server (NTRS)

    Helms, V. T., III

    1983-01-01

    Possible use of tip-fin controllers instead of a vertical tail on advanced winged entry vehicles was examined. Elimination of the vertical tail and using tip-fins offers the advantages of positive yaw control at high angles of attack and a potential weight savings. Oil-flow technique was used to obtain surface flow patterns on a tip-fin installed on a 0.01-scale Space Shuttle orbiter model for the purpose of assessing the extent of flow interference effects on the wing and tip-fin which might lead to serious heating problems. Tests were conducted in air at Mach 10 for a free-stream Reynolds numbers of .000113 at 20, 30, and 40 degree angle of attack and sideslip angles of 0 and 2 degree. Elevon deflections of -10, 0, and 10 degree and tip-fin control-surface deflections of 0, 20, and 40 degree were employed. Test results were also used to aid in the interpretation of heating data obtained on a Shuttle orbiter tip-fin on another model in a different facility. A limited comparison of oil-flow patterns and heat-transfer data is included. It was determined that elevon deflection angles from -10 to 10 degree and sideslip angles up to 2 degree have very little effect on tip-fin surface flow patterns. Also, there is a minimum of interference between the tip-fin and the wing. The most significant flow interactions occur on the tip-fin onboard surface as a result of its control-surface deflections.

  5. A robotic device with a passive undulating ribbon fin: kinematics and propulsive performance

    NASA Astrophysics Data System (ADS)

    Liu, Hanlin; Curet, Oscar

    2015-11-01

    Many aquatic animals swim with high maneuverability using undulating ribbon fins. In this type of swimming, the organism propels by sending one or multiple traveling waves along an elongated fin. In previous work, robotic models with fully actuated fins where the parameters of the traveling waves are fully prescribed have been used to study the propulsive performance and fluid dynamics of this type of propulsion. However, less work has been done in ribbon fins with passively undulating waves. In this work, we use a robotic device to study the kinematics and propulsive performance of a passively undulating ribbon fin. The physical model is composed of fifteen rays interconnected with a membrane. Only two rays are actuated while the other rays are free to rotate through a common axis. The robotic fin was tested in a flume at different flow conditions. In a series of experiments we measured fin kinematics, propulsive forces and power consumption. As the leading two rays are actuated, a traveling wave with decaying amplitude passes through the passive rays. As the frequency of the actuated rays increases, the enclosed area of the undulating wave and the traveling wave frequency increase while the wavelength decreases. Our data also show that the propulsive force generated by the fin scaled with the enclosed area and the square of the relative velocity between incoming flow and traveling wave. These results suggest that both natural swimmers and underwater vehicles using ribbon-fin-based propulsion can potentially take advantage of passive undulating waves. National Science Foundation Grant No. 1420774

  6. Roles for the Saccharomyces cerevisiae SDS3, CBK1 and HYM1 genes in transcriptional repression by SIN3.

    PubMed Central

    Dorland, S; Deegenaars, M L; Stillman, D J

    2000-01-01

    The Saccharomyces cerevisiae Sin3 transcriptional repressor is part of a large multiprotein complex that includes the Rpd3 histone deacetylase. A LexA-Sin3 fusion protein represses transcription of promoters with LexA binding sites. To identify genes involved in repression by Sin3, we conducted a screen for mutations that reduce repression by LexA-Sin3. One of the mutations identified that reduces LexA-Sin3 repression is in the RPD3 gene, consistent with the known roles of Rpd3 in transcriptional repression. Mutations in CBK1 and HYM1 reduce repression by LexA-Sin3 and also cause defects in cell separation and altered colony morphology. cbk1 and hym1 mutations affect some but not all genes regulated by SIN3 and RPD3, but the effect on transcription is much weaker. Genetic analysis suggests that CBK1 and HYM1 function in the same pathway, but this genetic pathway is separable from that of SIN3 and RPD3. The remaining gene from this screen described in this report is SDS3, previously identified in a screen for mutations that increase silencing at HML, HMR, and telomere-linked genes, a phenotype also seen in sin3 and rpd3 mutants. Genetic analysis demonstrates that SDS3 functions in the same genetic pathway as SIN3 and RPD3, and coimmunoprecipitation experiments show that Sds3 is physically present in the Sin3 complex. PMID:10655212

  7. sinI- and expR-dependent quorum sensing in Sinorhizobium meliloti.

    PubMed

    Gao, Mengsheng; Chen, Hancai; Eberhard, Anatol; Gronquist, Matthew R; Robinson, Jayne B; Rolfe, Barry G; Bauer, Wolfgang D

    2005-12-01

    Quorum sensing (QS) in Sinorhizobium meliloti, the N-fixing bacterial symbiont of Medicago host plants, involves at least half a dozen different N-acyl homoserine lactone (AHL) signals and perhaps an equal number of AHL receptors. The accumulation of 55 proteins was found to be dependent on SinI, the AHL synthase, and/or on ExpR, one of the AHL receptors. Gas chromatography-mass spectrometry and electrospray ionization tandem mass spectrometry identified 3-oxo-C(14)-homoserine lactone (3-oxo-C(14)-HSL), C(16)-HSL, 3-oxo-C(16)-HSL, C(16:1)-HSL, and 3-oxo-C(16:1)-HSL as the sinI-dependent AHL QS signals accumulated by the 8530 expR(+) strain under the conditions used for proteome analysis. The 8530 expR(+) strain secretes additional, unidentified QS-active compounds. Addition of 200 nM C(14)-HSL or C(16:1)-HSL, two of the known SinI AHLs, affected the levels of 75% of the proteins, confirming that their accumulation is QS regulated. A number of the QS-regulated proteins have functions plausibly related to symbiotic interactions with the host, including ExpE6, IdhA, MocB, Gor, PckA, LeuC, and AglE. Seven of 10 single-crossover beta-glucuronidase (GUS) transcriptional reporters in genes corresponding to QS-regulated proteins showed significantly different activities in the sinI and expR mutant backgrounds and in response to added SinI AHLs. The sinI mutant and several of the single-crossover strains were significantly delayed in the ability to initiate nodules on the primary root of the host plant, Medicago truncatula, indicating that sinI-dependent QS regulation and QS-regulated proteins contribute importantly to the rate or efficiency of nodule initiation. The sinI and expR mutants were also defective in surface swarming motility. The sinI mutant was restored to normal swarming by 5 nM C(16:1)-HSL.

  8. Development of the activated diffusion brazing process for fabrication of finned shell to strut turbine blades

    NASA Technical Reports Server (NTRS)

    Wilbers, L. G.; Berry, T. F.; Kutchera, R. E.; Edmonson, R. E.

    1971-01-01

    The activated diffusion brazing process was developed for attaching TD-NiCr and U700 finned airfoil shells to matching Rene 80 struts obstructing the finned cooling passageways. Creep forming the finned shells to struts in combination with precise preplacement of brazing alloy resulted in consistently sound joints, free of cooling passageway clogging. Extensive tensile and stress rupture testing of several joint orientation at several temperatures provided a critical assessment of joint integrity of both material combinations. Trial blades of each material combination were fabricated followed by destructive metallographic examination which verified high joint integrity.

  9. Fin-Opening Dynamics for an 8-Inch Gun Launched Extended-Range Guided Projectile

    DTIC Science & Technology

    1978-12-11

    including-the.’ addition of more fin bending degrees of freedom. Comparison was made between the analysis results and a limited amount of experimental...involved in eqn. 3 are developed in Appendix A. The solution procelure for numerizal analysis involves expressing the equations in matrix form as: a q = g...15Y5T E M7PNE L~~ FIG.5: PLATE ELEMENT LAYOUT FOR FIN kI rhe fin element model was used as data input to a structural analysis program, SAP IV

  10. Numerical solution for laminar film condensation of pure refrigerant on a vertical finned surface

    SciTech Connect

    Yu, Jian; Matsumoto, Tatsuya; Koyama, Shigeru

    1999-07-01

    Plate-fin heat exchangers are widely used in chemical plants for their high heat transfer performance, and have attracted special interests recently in heat pump and refrigeration systems. Many researchers have studied this kind of heat exchanger in single-phase region in detail, but most of these studies could not be extended to two-phase flow region. In the present study, a numerical analysis for the laminar film condensation on a finned vertical surface is carried out to clarify the heat transfer characteristics of plate-fin condensers. In the analysis the following assumptions are employed. (1) The bulk vapor is pure and saturated, and the effect of viscous shear of vapor on the liquid film is negligible. (2) The condensed liquid flows not only in vertical direction by gravitational force, but in horizontal direction by surface tension. (3) The heat conduction in the fin is one-dimensional, and the base surface temperature is a constant. (4) The effect of curvature of liquid film surface in z direction is not considered on the distribution of liquid film thickness and heat transfer characteristics. The governing equation of the liquid film thickness and one-dimensional heat conduction equation in the fin are numerically solved using the finite difference method. Three-dimensional distribution of the condensed liquid film thickness, the pressure and the radius of liquid film in horizontal direction, the distributions of average heat flux and the Nusselt number along the vertical direction are obtained. From a series of calculation results, the effects of fin pitch, fin height, fin thickness, fin length and the radius of concave joint region of base plate and fin on the liquid film shape are shown, and the effects of the fin shape parameters on heat transfer enhancement ratio are examined. The average Nusselt number on a vertical finned surface, Nu{sub m}, are correlated by the Bond number Bo, the Galileo number Ga{sub L}, the phase change number Ph, and the

  11. Thermal Analysis of the X-38 Aft Fin During Re-Entry

    NASA Technical Reports Server (NTRS)

    Hong, Andrew E.

    1999-01-01

    This document contains the details of the thermal analysis of the X-38 aft fin during re-entry. This analysis was performed in order to calculate temperature response of the aft fin components. This would be provided as input to a structural analysis and would also define the operating environment for the electromechanical actuator (EMA). The calculated structural temperature response would verify the performance of the thermal protection system (TPS). The geometric representation of the aft fin was derived from an I-DEAS finite element model that was used for structural analysis. The thermal mass network model was derived from the geometric representation.

  12. Effect of caudal fin flexibility on the propulsive efficiency of a fish-like swimmer.

    PubMed

    Bergmann, M; Iollo, A; Mittal, R

    2014-09-25

    A computational model is used to examine the effect of caudal fin flexibility on the propulsive efficiency of a self-propelled swimmer. The computational model couples a penalization method based Navier-Stokes solver with a simple model of flow induced deformation and self-propelled motion at an intermediate Reynolds number of about 1000. The results indicate that a significant increase in efficiency is possible by careful choice of caudal fin rigidity. The flow-physics underlying this observation is explained through the use of a simple hydrodynamic force model and guidelines for bioinspired designs of flexible fin propulsors are proposed.

  13. A Numerical Study on Hydrodynamics of Pectoral Fin Locomotion in Batoid Fishes

    NASA Astrophysics Data System (ADS)

    Hu, W. R.

    The mechanics of aquatic locomotion are of interest to biologists, dynamicists and engineers. Batoid fishes (skates and rays) propel themselves through the water primarily with their greatly expanded pectoral fins (pectoral-fin-based locomotion). Batoids exhibit two modes of pectoral swiminng behavior: (1) undulatory locomotion, termed ‘rajiform’, and (2) oscillatory locomotion, termed ‘mobuliform’. A computational study on the unsteady hydrodynamics of pectoral fin locomotion of Rhinoptera Bonasus and Dasyatis Sabina is carried out and presented, which represent the undulatory and oscillatory locomotion, respectively. Unsteady hydrodynamics around a pectoral fin is solved by a time-accurate solution of incompressible, laminar Navier-Stokes equations. Kinematic data of the pectoral fin locomotion used in the computational modeling are based on the experimental results. The pressure distribution of the pectoral fin was computed and integrated to give forces which were decomposed into lift and thrust. The velocity and vorticity field variation on the surface of pectoral fins and in the near-wake was computed throughout the swimming cycle. In the present study, we analyzed and compared the hydrodynamics and mechanmism of the Batoid pectoral fin locomotion between the two modes, and discovered how these patterns change with controllable factors, such as Renolds number, frequency, amplitude etc. The results show that forces on the fins of Rhinoptera Bonasus are much larger than that of Dasyatis Sabina. The load-bearing areas of Rhinoptera Bonasus are at the areas from the leading edge to the medial of the wing; while the load-bearing area of Dasyatis Sabina is the whole wavy fin. These characters are associated with the morphology of the wing skeleton. The propulsive mechanism of pectoral-fin-based locomotion is similar to that of the caudal-fin-based locomotion. A strong backward jet-stream in the wake contributes the net thrust, which is induced by the

  14. Cooling system having reduced mass pin fins for components in a gas turbine engine

    DOEpatents

    Lee, Ching-Pang; Jiang, Nan; Marra, John J

    2014-03-11

    A cooling system having one or more pin fins with reduced mass for a gas turbine engine is disclosed. The cooling system may include one or more first surfaces defining at least a portion of the cooling system. The pin fin may extend from the surface defining the cooling system and may have a noncircular cross-section taken generally parallel to the surface and at least part of an outer surface of the cross-section forms at least a quartercircle. A downstream side of the pin fin may have a cavity to reduce mass, thereby creating a more efficient turbine airfoil.

  15. Investigation of defect-induced abnormal body current in fin field-effect-transistors

    SciTech Connect

    Liu, Kuan-Ju; Tsai, Jyun-Yu; Lu, Ying-Hsin; Liu, Xi-Wen; Chang, Ting-Chang; Chen, Ching-En; Yang, Ren-Ya; Cheng, Osbert; Huang, Cheng-Tung

    2015-08-24

    This letter investigates the mechanism of abnormal body current at the linear region in n-channel high-k/metal gate stack fin field effect transistors. Unlike body current, which is generated by impact ionization at high drain voltages, abnormal body current was found to increase with decreasing drain voltages. Notably, the unusual body leakage only occurs in three-dimensional structure devices. Based on measurements under different operation conditions, the abnormal body current can be attributed to fin surface defect-induced leakage current, and the mechanism is electron tunneling to the fin via the defects, resulting in holes left at the body terminal.

  16. Fin whale vocalizations observed with ocean bottom seismometers of cabled observatories off east Japan Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Iwase, Ryoichi

    2015-07-01

    Fin whale vocalizations were found in the archived waveform data from both hydrophones and ocean bottom seismometers (OBSs) of a cabled observatory off Kushiro-Tokachi in Hokkaido. A fin whale was localized on the basis of the incident orientation estimated with a single OBS and the time difference of multipath arrival of sound pressure data from a hydrophone. Furthermore, several fin whale vocalizations were found in the archived OBS waveform data from other cabled observatories off east Japan Pacific Ocean. These findings suggest that the cabled OBSs would be significant apparatuses for real-time monitoring of the presence of baleen whales around Japan.

  17. SinEx DB: a database for single exon coding sequences in mammalian genomes.

    PubMed

    Jorquera, Roddy; Ortiz, Rodrigo; Ossandon, F; Cárdenas, Juan Pablo; Sepúlveda, Rene; González, Carolina; Holmes, David S

    2016-01-01

    Eukaryotic genes are typically interrupted by intragenic, noncoding sequences termed introns. However, some genes lack introns in their coding sequence (CDS) and are generally known as 'single exon genes' (SEGs). In this work, a SEG is defined as a nuclear, protein-coding gene that lacks introns in its CDS. Whereas, many public databases of Eukaryotic multi-exon genes are available, there are only two specialized databases for SEGs. The present work addresses the need for a more extensive and diverse database by creating SinEx DB, a publicly available, searchable database of predicted SEGs from 10 completely sequenced mammalian genomes including human. SinEx DB houses the DNA and protein sequence information of these SEGs and includes their functional predictions (KOG) and the relative distribution of these functions within species. The information is stored in a relational database built with My SQL Server 5.1.33 and the complete dataset of SEG sequences and their functional predictions are available for downloading. SinEx DB can be interrogated by: (i) a browsable phylogenetic schema, (ii) carrying out BLAST searches to the in-house SinEx DB of SEGs and (iii) via an advanced search mode in which the database can be searched by key words and any combination of searches by species and predicted functions. SinEx DB provides a rich source of information for advancing our understanding of the evolution and function of SEGs.Database URL: www.sinex.cl.

  18. SinEx DB: a database for single exon coding sequences in mammalian genomes

    PubMed Central

    Jorquera, Roddy; Ortiz, Rodrigo; Ossandon, F.; Cárdenas, Juan Pablo; Sepúlveda, Rene; González, Carolina; Holmes, David S.

    2016-01-01

    Eukaryotic genes are typically interrupted by intragenic, noncoding sequences termed introns. However, some genes lack introns in their coding sequence (CDS) and are generally known as ‘single exon genes’ (SEGs). In this work, a SEG is defined as a nuclear, protein-coding gene that lacks introns in its CDS. Whereas, many public databases of Eukaryotic multi-exon genes are available, there are only two specialized databases for SEGs. The present work addresses the need for a more extensive and diverse database by creating SinEx DB, a publicly available, searchable database of predicted SEGs from 10 completely sequenced mammalian genomes including human. SinEx DB houses the DNA and protein sequence information of these SEGs and includes their functional predictions (KOG) and the relative distribution of these functions within species. The information is stored in a relational database built with My SQL Server 5.1.33 and the complete dataset of SEG sequences and their functional predictions are available for downloading. SinEx DB can be interrogated by: (i) a browsable phylogenetic schema, (ii) carrying out BLAST searches to the in-house SinEx DB of SEGs and (iii) via an advanced search mode in which the database can be searched by key words and any combination of searches by species and predicted functions. SinEx DB provides a rich source of information for advancing our understanding of the evolution and function of SEGs. Database URL: www.sinex.cl PMID:27278816

  19. A Positive Feedback Loop between Akt and mTORC2 via SIN1 Phosphorylation.

    PubMed

    Yang, Guang; Murashige, Danielle S; Humphrey, Sean J; James, David E

    2015-08-11

    The mechanistic target of rapamycin complex 2 (mTORC2) regulates cell survival and cytoskeletal organization by phosphorylating its AGC kinase substrates; however, little is known about the regulation of mTORC2 itself. It was previously reported that Akt phosphorylates the mTORC2 subunit SIN1 at T86, activating mTORC2 through a positive feedback loop, though another study reported that S6K phosphorylates SIN1 at the same site, inhibiting mTORC2 activity. We performed extensive analysis of SIN1 phosphorylation upon inhibition of Akt, S6K, and mTOR under diverse cellular contexts, and we found that, in all cell lines and conditions studied, Akt is the major kinase responsible for SIN1 phosphorylation. These findings refine the activation mechanism of the Akt-mTORC2 signaling branch as follows: PDK1 phosphorylates Akt at T308, increasing Akt kinase activity. Akt phosphorylates SIN1 at T86, enhancing mTORC2 kinase activity, which leads to phosphorylation of Akt S473 by mTORC2, thereby catalyzing full activation of Akt.

  20. Phylogenetic informativeness reconciles ray-finned fish molecular divergence times

    PubMed Central

    2014-01-01

    Background Discordance among individual molecular age estimates, or between molecular age estimates and the fossil record, is observed in many clades across the Tree of Life. This discordance is attributed to a variety of variables including calibration age uncertainty, calibration placement, nucleotide substitution rate heterogeneity, or the specified molecular clock model. However, the impact of changes in phylogenetic informativeness of individual genes over time on phylogenetic inferences is rarely analyzed. Using nuclear and mitochondrial sequence data for ray-finned fishes (Actinopterygii) as an example, we extend the utility of phylogenetic informativeness profiles to predict the time intervals when nucleotide substitution saturation results in discordance among molecular ages estimated. Results We demonstrate that even with identical calibration regimes and molecular clock methods, mitochondrial based molecular age estimates are systematically older than those estimated from nuclear sequences. This discordance is most severe for highly nested nodes corresponding to more recent (i.e., Jurassic-Recent) divergences. By removing data deemed saturated, we reconcile the competing age estimates and highlight that the older mtDNA based ages were driven by nucleotide saturation. Conclusions Homoplasious site patterns in a DNA sequence alignment can systematically bias molecular divergence time estimates. Our study demonstrates that PI profiles can provide a non-arbitrary criterion for data exclusion to mitigate the influence of homoplasy on time calibrated branch length estimates. Analyses of actinopterygian molecular clocks demonstrate that scrutiny of the time scale on which sequence data is informative is a fundamental, but generally overlooked, step in molecular divergence time estimation. PMID:25103329

  1. Line edge roughness induced threshold voltage variability in nano-scale FinFETs

    NASA Astrophysics Data System (ADS)

    Rathore, Rituraj Singh; Sharma, Rajneesh; Rana, Ashwani K.

    2017-03-01

    In aggressively scaled devices, the FinFET technology has become more prone to line edge roughness (LER) induced threshold voltage variability. As a result, nano scale FinFET structures face the problem of intrinsic statistical fluctuations in the threshold voltage. This paper describes the all LER induced variability of threshold voltage for 14 nm underlap FinFET using 3-D numerical simulations. It is concluded that percentage threshold voltage (VTH) fluctuations referenced with respect to rectangular FinFET can go up to 8.76%. This work has also investigated the impact of other sources of variability such as random dopant fluctuation, work function variation and oxide thickness variation on threshold voltage.

  2. Experimental study of heat transfer and thermal performance with longitudinal fins of solar air heater

    PubMed Central

    Chabane, Foued; Moummi, Noureddine; Benramache, Said

    2013-01-01

    The thermal performance of a single pass solar air heater with five fins attached was investigated experimentally. Longitudinal fins were used inferior the absorber plate to increase the heat exchange and render the flow fluid in the channel uniform. The effect of mass flow rate of air on the outlet temperature, the heat transfer in the thickness of the solar collector, and the thermal efficiency were studied. Experiments were performed for two air mass flow rates of 0.012 and 0.016 kg s−1. Moreover, the maximum efficiency values obtained for the 0.012 and 0.016 kg s−1 with and without fins were 40.02%, 51.50% and 34.92%, 43.94%, respectively. A comparison of the results of the mass flow rates by solar collector with and without fins shows a substantial enhancement in the thermal efficiency. PMID:25685486

  3. Experimental study of heat transfer and thermal performance with longitudinal fins of solar air heater.

    PubMed

    Chabane, Foued; Moummi, Noureddine; Benramache, Said

    2014-03-01

    The thermal performance of a single pass solar air heater with five fins attached was investigated experimentally. Longitudinal fins were used inferior the absorber plate to increase the heat exchange and render the flow fluid in the channel uniform. The effect of mass flow rate of air on the outlet temperature, the heat transfer in the thickness of the solar collector, and the thermal efficiency were studied. Experiments were performed for two air mass flow rates of 0.012 and 0.016 kg s(-1). Moreover, the maximum efficiency values obtained for the 0.012 and 0.016 kg s(-1) with and without fins were 40.02%, 51.50% and 34.92%, 43.94%, respectively. A comparison of the results of the mass flow rates by solar collector with and without fins shows a substantial enhancement in the thermal efficiency.

  4. The giant fiber and pectoral fin adductor motoneuron system in the hatchetfish.

    PubMed

    Gilat, E; Hall, D H; Bennett, M V

    1986-02-12

    In the medulla of the hatchetfish each Mauthner fiber forms chemical synapses on a number of large myelinated axons termed giant fibers. The giant fibers form rectifying electrotonic synapses on pectoral fin adductor motoneurons, and in this fish bilateral pectoral fin adduction is an important component of the Mauthner fiber-mediated escape reflex. The branching patterns of giant fibers were determined by intracellular injection of Lucifer yellow. Dye coupling to the motoneuron somata was not observed, although a low level of transfer might have been obscured by autofluorescence. Individual giant fibers terminate primarily on pectoral fin motoneurons contralateral to their cell bodies, but may also send a branch back across the midline to ipsilateral motoneurons. The rostral process of each giant fiber ends on neurons presumably associated with cranial musculature. The number and geometry of the pectoral fin motoneurons were determined using Golgi and Nissl staining and serial reconstruction methods.

  5. Total Ionizing Dose Effects on Strained Ge pMOS FinFETs on Bulk Si

    DOE PAGES

    Zhang, En Xia; Fleetwood, Daniel M.; Hachtel, Jordan A.; ...

    2016-12-02

    In this paper, we have characterized the total ionizing dose response of strained Ge p MOS FinFETs built on bulk Si using a fin replacement process. Devices irradiated to 1.0 Mrad(SiO2) show minimal transconductance degradation (less than 5%), very small Vth shifts (less than 40 mV in magnitude) and very little ON/OFF current ratio degradation (<5%), and only modest variation in radiation response with transistor geometry (typically less than normal part-to-part variation). Both before and after irradiation, the performance of these strained Ge p MOS FinFETs is far superior to that of past generations of planar Ge p MOS devices.more » Finally, these improved properties result from significant improvements in processing technology, as well as the enhanced gate control provided by the strained Ge FinFET technology.« less

  6. Total Ionizing Dose Effects on Strained Ge pMOS FinFETs on Bulk Si

    SciTech Connect

    Zhang, En Xia; Fleetwood, Daniel M.; Hachtel, Jordan A.; Oak Ridge National Lab. , Oak Ridge, TN ; Liang, Chundong; Reed, Robert A.; Alles, Michael L.; Schrimpf, Ronald D.; Linten, Dimitri; Mitard, Jerome; Chisholm, Matthew F.; Pantelides, Sokrates T.; Oak Ridge National Lab. , Oak Ridge, TN

    2016-12-02

    In this paper, we have characterized the total ionizing dose response of strained Ge p MOS FinFETs built on bulk Si using a fin replacement process. Devices irradiated to 1.0 Mrad(SiO2) show minimal transconductance degradation (less than 5%), very small Vth shifts (less than 40 mV in magnitude) and very little ON/OFF current ratio degradation (<5%), and only modest variation in radiation response with transistor geometry (typically less than normal part-to-part variation). Both before and after irradiation, the performance of these strained Ge p MOS FinFETs is far superior to that of past generations of planar Ge p MOS devices. Finally, these improved properties result from significant improvements in processing technology, as well as the enhanced gate control provided by the strained Ge FinFET technology.

  7. Numerical study of thermal performance of perforated circular pin fin heat sinks in forced convection

    NASA Astrophysics Data System (ADS)

    Wen, Mao-Yu; Yeh, Cheng-Hsiung

    2016-12-01

    This paper presents a numerical simulation of the heat transfer performance under forced convection for two different types of circular pin fin heat sinks with (Type A) and without (Type B) a hollow in the heated base. COMSOL Multiphysics, which is used for the thermal hydraulic analyses, has proven to be a powerful finite-element-based simulation tool for solving multiple physics-based systems of partial and ordinary differential equations. The standard κ- ɛ two-equations turbulence model is employed to describe the turbulent structure and behavior. The numerical results are validated with the experimental results, and are shown to be in good agreement. The effects of the Reynolds number, height of the fin, finning factor and the perforated base plate on the heat-transfer coefficient are investigated and evaluated. The present study strongly recommends the use of a small hollow ( (Dh /Db ) < 0.15 ) constructed in the base plate of the pin fin heat sink.

  8. Supersonic aerodynamic characteristics of a series of wrap-around-fin missile configurations

    NASA Technical Reports Server (NTRS)

    Fournier, R. H.

    1977-01-01

    A parametric study of wrap-around-fin missile configurations was conducted at Mach numbers from 1.60 to 2.86 in the Langley Unitary Plan wind tunnel. The fin configurations investigated included variations in chord length, leading edge sweep, thickness ratio, and leading edge shape. The investigation also included a smooth and a stepped-down afterbody required for flush retraction of the wrap-around-fin configuration. The investigation indicated no unusual longitudinal characteristics; however, all the wrap-around-fin configurations tested indicated erratic lateral behavior, particularly in the form of induced roll at zero angle of attack and irregular variations of roll with angle of attack and Mach number. The magnitude of rolling moment at an angle of attack of 0 deg is estimated to represent approximately 0.25 deg or less roll control deflection. The stepped-down afterbody has a marked effect on reducing the induced roll.

  9. In vivo electroporation of morpholinos into the regenerating adult zebrafish tail fin.

    PubMed

    Hyde, David R; Godwin, Alan R; Thummel, Ryan

    2012-03-29

    Certain species of urodeles and teleost fish can regenerate their tissues. Zebrafish have become a widely used model to study the spontaneous regeneration of adult tissues, such as the heart, retina, spinal cord, optic nerve, sensory hair cells, and fins. The zebrafish fin is a relatively simple appendage that is easily manipulated to study multiple stages in epimorphic regeneration. Classically, fin regeneration was characterized by three distinct stages: wound healing, blastema formation, and fin outgrowth. After amputating part of the fin, the surrounding epithelium proliferates and migrates over the wound. At 33 °C, this process occurs within six hours post-amputation (hpa, Figure 1B). Next, underlying cells from different lineages (ex. bone, blood, glia, fibroblast) re-enter the cell cycle to form a proliferative blastema, while the overlying epidermis continues to proliferate (Figure 1D). Outgrowth occurs as cells proximal to the blastema re-differentiate into their respective lineages to form new tissue (Figure 1E). Depending on the level of the amputation, full regeneration is completed in a week to a month. The expression of a large number of gene families, including wnt, hox, fgf, msx, retinoic acid, shh, notch, bmp, and activin-betaA genes, is up-regulated during specific stages of fin regeneration. However, the roles of these genes and their encoded proteins during regeneration have been difficult to assess, unless a specific inhibitor for the protein exists, a temperature-sensitive mutant exists or a transgenic animal (either overexpressing the wild-type protein or a dominant-negative protein) was generated. We developed a reverse genetic technique to quickly and easily test the function of any gene during fin regeneration. Morpholino oligonucleotides are widely used to study loss of specific proteins during zebrafish, Xenopus, chick, and mouse development. Morpholinos basepair with a complementary RNA sequence to either block pre-mRNA splicing or m

  10. Characterization of Si-N films prepared by reactive ion beam sputtering

    NASA Astrophysics Data System (ADS)

    Aggarwal, M. D.; Ashok, S.; Fonash, S. J.

    1982-05-01

    Application of silicon-nitride (Si-N) as a passivant in com-pound semiconductor technology requires a low-temperature deposition process to prevent dissociation of the volatile constituents of the semiconductor. With this in mind, an exploratory study of Si-N films prepared at room temperature using low-energy, reactive ion-beam sputtering has been carried out. The electrical and optical characteristics of the films have been studied, and an annealing step is found necessary to reduce the conductivity of the nitride and im-prove the interfacial properties.

  11. Measurement of sin 2β with hadronic and previously unused muonic J/ψ decays

    NASA Astrophysics Data System (ADS)

    Aubert, B.; Barate, R.; Boutigny, D.; Gaillard, J.-M.; Hicheur, A.; Karyotakis, Y.; Lees, J. P.; Robbe, P.; Tisserand, V.; Zghiche, A.; Palano, A.; Pompili, A.; Chen, J. C.; Qi, N. D.; Rong, G.; Wang, P.; Zhu, Y. S.; Eigen, G.; Ofte, I.; Stugu, B.; Abrams, G. S.; Borgland, A. W.; Breon, A. B.; Brown, D. N.; Button-Shafer, J.; Cahn, R. N.; Charles, E.; Day, C. T.; Gill, M. S.; Gritsan, A. V.; Groysman, Y.; Jacobsen, R. G.; Kadel, R. W.; Kadyk, J.; Kerth, L. T.; Kolomensky, Yu. G.; Kral, J. F.; Kukartsev, G.; Leclerc, C.; Levi, M. E.; Lynch, G.; Mir, L. M.; Oddone, P. J.; Orimoto, T. J.; Pripstein, M.; Roe, N. A.; Romosan, A.; Ronan, M. T.; Shelkov, V. G.; Telnov, A. V.; Wenzel, W. A.; Ford, K.; Harrison, T. J.; Hawkes, C. M.; Knowles, D. J.; Morgan, S. E.; Penny, R. C.; Watson, A. T.; Watson, N. K.; Goetzen, K.; Held, T.; Koch, H.; Lewandowski, B.; Pelizaeus, M.; Peters, K.; Schmuecker, H.; Steinke, M.; Boyd, J. T.; Chevalier, N.; Cottingham, W. N.; Kelly, M. P.; Latham, T. E.; Mackay, C.; Wilson, F. F.; Abe, K.; Cuhadar-Donszelmann, T.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; Thiessen, D.; Kyberd, P.; McKemey, A. K.; Blinov, V. E.; Bukin, A. D.; Golubev, V. B.; Ivanchenko, V. N.; Kravchenko, E. A.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Yushkov, A. N.; Best, D.; Bruinsma, M.; Chao, M.; Kirkby, D.; Lankford, A. J.; Mandelkern, M.; Mommsen, R. K.; Roethel, W.; Stoker, D. P.; Buchanan, C.; Hartfiel, B. L.; Shen, B. C.; del Re, D.; Hadavand, H. K.; Hill, E. J.; Macfarlane, D. B.; Paar, H. P.; Rahatlou, Sh.; Schwanke, U.; Sharma, V.; Berryhill, J. W.; Campagnari, C.; Dahmes, B.; Kuznetsova, N.; Levy, S. L.; Long, O.; Lu, A.; Mazur, M. A.; Richman, J. D.; Verkerke, W.; Beck, T. W.; Beringer, J.; Eisner, A. M.; Heusch, C. A.; Lockman, W. S.; Schalk, T.; Schmitz, R. E.; Schumm, B. A.; Seiden, A.; Turri, M.; Walkowiak, W.; Williams, D. C.; Wilson, M. G.; Albert, J.; Chen, E.; Dubois-Felsmann, G. P.; Dvoretskii, A.; Hitlin, D. G.; Narsky, I.; Porter, F. C.; Ryd, A.; Samuel, A.; Yang, S.; Jayatilleke, S.; Mancinelli, G.; Meadows, B. T.; Sokoloff, M. D.; Abe, T.; Blanc, F.; Bloom, P.; Chen, S.; Clark, P. J.; Ford, W. T.; Nauenberg, U.; Olivas, A.; Rankin, P.; Roy, J.; Smith, J. G.; van Hoek, W. C.; Zhang, L.; Harton, J. L.; Hu, T.; Soffer, A.; Toki, W. H.; Wilson, R. J.; Zhang, J.; Aleksan, R.; Emery, S.; Gaidot, A.; Ganzhur, S. F.; Giraud, P.-F.; Hamel de Monchenault, G.; Kozanecki, W.; Langer, M.; Legendre, M.; London, G. W.; Mayer, B.; Schott, G.; Vasseur, G.; Yeche, Ch.; Zito, M.; Altenburg, D.; Brandt, T.; Brose, J.; Colberg, T.; Dickopp, M.; Dubitzky, R. S.; Hauke, A.; Lacker, H. M.; Maly, E.; Müller-Pfefferkorn, R.; Nogowski, R.; Otto, S.; Schubert, J.; Schubert, K. R.; Schwierz, R.; Spaan, B.; Wilden, L.; Bernard, D.; Bonneaud, G. R.; Brochard, F.; Cohen-Tanugi, J.; Grenier, P.; Thiebaux, Ch.; Vasileiadis, G.; Verderi, M.; Khan, A.; Lavin, D.; Muheim, F.; Playfer, S.; Swain, J. E.; Andreotti, M.; Azzolini, V.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Cibinetto, G.; Luppi, E.; Negrini, M.; Piemontese, L.; Sarti, A.; Treadwell, E.; Anulli, F.; Baldini-Ferroli, R.; Calcaterra, A.; de Sangro, R.; Falciai, D.; Finocchiaro, G.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Zallo, A.; Buzzo, A.; Capra, R.; Contri, R.; Crosetti, G.; Lo Vetere, M.; Macri, M.; Monge, M. R.; Passaggio, S.; Patrignani, C.; Robutti, E.; Santroni, A.; Tosi, S.; Bailey, S.; Morii, M.; Won, E.; Bhimji, W.; Bowerman, D. A.; Dauncey, P. D.; Egede, U.; Eschrich, I.; Gaillard, J. R.; Morton, G. W.; Nash, J. A.; Sanders, P.; Taylor, G. P.; Grenier, G. J.; Lee, S.-J.; Mallik, U.; Cochran, J.; Crawley, H. B.; Lamsa, J.; Meyer, W. T.; Prell, S.; Rosenberg, E. I.; Yi, J.; Biasini, M.; Pioppi, M.; Davier, M.; Grosdidier, G.; Höcker, A.; Laplace, S.; Le Diberder, F.; Lepeltier, V.; Lutz, A. M.; Petersen, T. C.; Plaszczynski, S.; Schune, M. H.; Tantot, L.; Wormser, G.; Brigljević, V.; Cheng, C. H.; Lange, D. J.; Wright, D. M.; Bevan, A. J.; Coleman, J. P.; Fry, J. R.; Gabathuler, E.; Gamet, R.; Kay, M.; Parry, R. J.; Payne, D. J.; Sloane, R. J.; Touramanis, C.; Back, J. J.; Harrison, P. F.; Shorthouse, H. W.; Strother, P.; Vidal, P. B.; Brown, C. L.; Cowan, G.; Flack, R. L.; Flaecher, H. U.; George, S.; Green, M. G.; Kurup, A.; Marker, C. E.; McMahon, T. R.; Ricciardi, S.; Salvatore, F.; Vaitsas, G.; Winter, M. A.; Brown, D.; Davis, C. L.; Allison, J.; Barlow, N. R.; Barlow, R. J.; Hart, P. A.; Jackson, F.; Lafferty, G. D.; Lyon, A. J.; Weatherall, J. H.; Williams, J. C.; Farbin, A.; Jawahery, A.; Kovalskyi, D.; Lae, C. K.; Lillard, V.; Roberts, D. A.; Blaylock, G.; Dallapiccola, C.; Flood, K. T.; Hertzbach, S. S.; Kofler, R.; Koptchev, V. B.; Moore, T. B.; Saremi, S.; Staengle, H.; Willocq, S.; Cowan, R.; Sciolla, G.; Taylor, F.; Yamamoto, R. K.; Mangeol, D. J.; Milek, M.; Patel, P. M.; Robertson, S. H.; Lazzaro, A.; Palombo, F.; Bauer, J. M.; Cremaldi, L.; Eschenburg, V.; Godang, R.; Kroeger, R.; Reidy, J.; Sanders, D. A.; Summers, D. J.; Zhao, H. W.; Brunet, S.; Cote-Ahern, D.; Taras, P.; Nicholson, H.; Raven, G.; Cartaro, C.; Cavallo, N.; de Nardo, G.; Fabozzi, F.; Gatto, C.; Lista, L.; Paolucci, P.; Piccolo, D.; Sciacca, C.; Losecco, J. M.; Gabriel, T. A.; Brau, B.; Gan, K. K.; Honscheid, K.; Hufnagel, D.; Kagan, H.; Kass, R.; Pulliam, T.; Wong, Q. K.; Brau, J.; Frey, R.; Potter, C. T.; Sinev, N. B.; Strom, D.; Torrence, E.; Colecchia, F.; Dorigo, A.; Galeazzi, F.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simonetto, F.; Stroili, R.; Tiozzo, G.; Voci, C.; Benayoun, M.; Briand, H.; Chauveau, J.; David, P.; de La Vaissière, Ch.; del Buono, L.; Hamon, O.; John, M. J.; Leruste, Ph.; Ocariz, J.; Pivk, M.; Roos, L.; Stark, J.; T'jampens, S.; Therin, G.; Manfredi, P. F.; Re, V.; Behera, P. K.; Gladney, L.; Guo, Q. H.; Panetta, J.; Angelini, C.; Batignani, G.; Bettarini, S.; Bondioli, M.; Bucci, F.; Calderini, G.; Carpinelli, M.; del Gamba, V.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Marchiori, G.; Martinez-Vidal, F.; Morganti, M.; Neri, N.; Paoloni, E.; Rama, M.; Rizzo, G.; Sandrelli, F.; Walsh, J.; Haire, M.; Judd, D.; Paick, K.; Wagoner, D. E.; Cavoto, G.; Danielson, N.; Elmer, P.; Lu, C.; Miftakov, V.; Olsen, J.; Smith, A. J.; Tanaka, H. A.; Varnes, E. W.; Bellini, F.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Mazzoni, M. A.; Morganti, S.; Pierini, M.; Piredda, G.; Safai Tehrani, F.; Voena, C.; Christ, S.; Wagner, G.; Waldi, R.; Adye, T.; de Groot, N.; Franek, B.; Geddes, N. I.; Gopal, G. P.; Olaiya, E. O.; Xella, S. M.; Purohit, M. V.; Weidemann, A. W.; Yumiceva, F. X.; Aston, D.; Bartoldus, R.; Berger, N.; Boyarski, A. M.; Buchmueller, O. L.; Convery, M. R.; Coupal, D. P.; Dong, D.; Dorfan, J.; Dujmic, D.; Dunwoodie, W.; Field, R. C.; Glanzman, T.; Gowdy, S. J.; Grauges-Pous, E.; Hadig, T.; Halyo, V.; Hryn'ova, T.; Innes, W. R.; Jessop, C. P.; Kelsey, M. H.; Kim, P.; Kocian, M. L.; Langenegger, U.; Leith, D. W.; Luitz, S.; Luth, V.; Lynch, H. L.; Marsiske, H.; Messner, R.; Muller, D. R.; O'Grady, C. P.; Ozcan, V. E.; Perazzo, A.; Perl, M.; Petrak, S.; Ratcliff, B. N.; Roodman, A.; Salnikov, A. A.; Schindler, R. H.; Schwiening, J.; Simi, G.; Snyder, A.; Soha, A.; Stelzer, J.; Su, D.; Sullivan, M. K.; Va'Vra, J.; Wagner, S. R.; Weaver, M.; Weinstein, A. J.; Wisniewski, W. J.; Wright, D. H.; Young, C. C.; Burchat, P. R.; Edwards, A. J.; Meyer, T. I.; Petersen, B. A.; Roat, C.; Ahmed, S.; Alam, M. S.; Ernst, J. A.; Saleem, M.; Wappler, F. R.; Bugg, W.; Krishnamurthy, M.; Spanier, S. M.; Eckmann, R.; Kim, H.; Ritchie, J. L.; Schwitters, R. F.; Izen, J. M.; Kitayama, I.; Lou, X. C.; Ye, S.; Bianchi, F.; Bona, M.; Gallo, F.; Gamba, D.; Borean, C.; Bosisio, L.; della Ricca, G.; Dittongo, S.; Grancagnolo, S.; Lanceri, L.; Poropat, P.; Vitale, L.; Vuagnin, G.; Panvini, R. S.; Banerjee, Sw.; Brown, C. M.; Fortin, D.; Jackson, P. D.; Kowalewski, R.; Roney, J. M.; Band, H. R.; Dasu, S.; Datta, M.; Eichenbaum, A. M.; Johnson, J. R.; Kutter, P. E.; Li, H.; Liu, R.; di Lodovico, F.; Mihalyi, A.; Mohapatra, A. K.; Pan, Y.; Prepost, R.; Sekula, S. J.; von Wimmersperg-Toeller, J. H.; Wu, J.; Wu, S. L.; Yu, Z.; Neal, H.

    2004-03-01

    We report a measurement of the CP-violation parameter sin 2β with B0→J/ψK0S decays in which the J/ψ decays to hadrons or to muons that do not satisfy our standard identification criteria. With a sample of 88 million BB¯ events collected by the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC, we reconstruct 100±17 such events, with J/ψ→π+π-π0 being the most prevalent, and measure sin 2β=1.56±0.42(stat)±0.21(syst).

  12. Plasmid-amplified comS enhances genetic competence and suppresses sinR in Bacillus subtilis.

    PubMed

    Liu, L; Nakano, M M; Lee, O H; Zuber, P

    1996-09-01

    The establishment of genetic competence in Bacillus subtilis is controlled by a vast signal transduction network involving the products of genes that function in several postexponential-phase processes. Two of these proteins, SinR and DegU, serve as molecular switches that influence a cell's decision to undergo either sporulation or genetic competence development. In order to determine the roles of SinR and DegU in competence control, multicopy suppression experiments with plasmid-amplified comS, SinR, and degU genes were undertaken. Multicopy comS was found to elevate competence gene transcription and transformation efficiency in both wild-type and sinR mutant cells but not in degU mutant cells. Multicopy degU failed to suppress comS or sinR mutations. No suppression of comS or degU by multicopy sinR was observed. The expression of a comS'::'lacZ translational fusion and srf-lacZ operon fusion was examined in sinR cells and cells bearing plasmid-amplified sinR. The expression of comS'::'lacZ gene fusion was reduced by the sinR mutation, but both comS'::'lacZ and srf-lacZ were repressed by multicopy sinR. Cells bearing plasmid-amplified sinR were poorly competent. These results suggest that sinR is required for optimal comS expression but not transcription from the srf promoter and that SinR at high concentrations represses srf transcription initiation.

  13. Atmospheric icing intensity on slowly rotating hexagonal prism and cylinder with fins

    NASA Astrophysics Data System (ADS)

    Mughal, Umair Najeeb; Virk, Muhammad Shakeel

    2017-01-01

    Atmospheric ice accretion intensities on constantly slowly rotating hexagonal prism with six fins and constantly slowly rotating cylinder with four fins were studied using experimental and mathematical analysis. The experimental intensities were compared with the existing ice accretion intensity models of Makkonen. Based upon this study a forced rotation constant and generalized windward area ratio is proposed to be added in the existing intensity models, in order to validate the experimental observations.

  14. Finned double-tube PCM system as a waste heat storage

    NASA Astrophysics Data System (ADS)

    Alhamdo, M. H.; Theeb, M. A.; Golam, A. S.

    2015-11-01

    In this work, focus is taken on developing a waste heat recovery system for capturing potential of exhaust heat from an air conditioner unit to be reused later. This system has the ability to store heat in phase change material (PCM) and then release it to a discharge water system when required. To achieve this goal, a system of Finned, Water-PCM, Double tube (FWD) has been developed and tested. Different profiles of fins attached to the (FWD) system have been investigated for increasing the thermal conductivity of the PCM. These include using Circular Finned, Water-PCM, Double tube (CFWD) system; Longitudinal Finned, Water-PCM, Double tube (LFWD) system; Spiral Finned, Water-PCM, Double tube (SFWD) system; as well as; Without Fins, Water-PCM, Double tube (WFWD) system. An experimental test rig that attached to an air-conditioner unit has been built to include 32- tubes of the FWD systems for both vertical and horizontal layouts during charging and water discharging processes. Results show a significant performance improvement when using spiral and circular fins during charging process at vertical position. However, longitudinal and without fins showed better performance in horizontal position. Overall, the developed SFWD system in vertical position has been found to exhibit the most effective type due to the fastest PCM melting and solidification. As compared to the WFWD system, the FWD systems have been found to increase the PCM temperature gain of about 15.3% for SFWD system; 8.2% for CFWD; and 4.3% for LFWD system.

  15. Sexual Dimorphism and Geographic Variation in Dorsal Fin Features of Australian Humpback Dolphins, Sousa sahulensis.

    PubMed

    Brown, Alexander M; Bejder, Lars; Parra, Guido J; Cagnazzi, Daniele; Hunt, Tim; Smith, Jennifer L; Allen, Simon J

    2016-01-01

    Determining the sex of free-ranging cetaceans can be challenging. Sexual dimorphism among external features may allow inferences on sex, but such patterns may be difficult to detect and are often confounded by age and geographic variation. Dorsal fin images of 107 female and 54 male Australian humpback dolphins, Sousa sahulensis, from Western Australia (WA) and Queensland (QLD) were used to investigate sex, age and geographic differences in colouration, height/length quotient and number of notches. Adult males exhibited more dorsal fin notches (p<0.001) and a significantly greater loss of pigmentation on the upper half of their dorsal fins (p<0.001) than did adult females. These differences likely reflect that males experience a higher frequency and/or intensity of intraspecific aggression than females. In QLD, heavily spotted dorsal fins were more frequent among females than males (p<0.001). Logistic regression analyses revealed that dorsal fin spotting and loss of pigmentation on the upper half of the dorsal fin provided the best model parameters for predicting the sex of sampled adults, with 97% accuracy. This technique offers a rapid, non-invasive method for predicting sex in Australian humpback dolphins, which could potentially be applied to populations throughout their range. In contrast to adults, presumed immature animals showed little or no loss of pigmentation or spotting; however, the rate of development of these features remains unknown. There were pronounced differences between QLD and WA in the intensity of spotting on dorsal fins and the extent of pigmentation loss around the posterior insertion and trailing edge of the dorsal fin. While based on a limited sample size, these geographic differences may have conservation implications in terms of population subdivision and should be investigated further.

  16. Filmwise Condensation on Low Integral-Fin Tubes of Different Diameter

    DTIC Science & Technology

    1988-12-01

    41 5.1 SUMMARY OF SIEDER -TATE COEFFICIENTS ......................... 60 5.2 SUMMARY OF R- 113...smooth tube (m 2 ) Ci Sieder -Tate-type coefficient Cp specific heat at constant pressure (J/kg K) Df fin diameter (m) Dr root diameter (m) e fin height (m...coefficients be known. During this study, 46 Sieder -Tate -type and Nusselt-type equations were used to represent the inside and outside, respectively. ko.14

  17. Fin-tail coordination during escape and predatory behavior in larval zebrafish.

    PubMed

    McClenahan, Phil; Troup, Michael; Scott, Ethan K

    2012-01-01

    Larval zebrafish innately perform a suite of behaviors that are tightly linked to their evolutionary past, notably escape from threatening stimuli and pursuit and capture of prey. These behaviors have been carefully examined in the past, but mostly with regard to the movements of the trunk and tail of the larvae. Here, we employ kinematics analyses to describe the movements of the pectoral fins during escape and predatory behavior. In accord with previous studies, we find roles for the pectoral fins in slow swimming and immediately after striking prey. We find novel roles for the pectoral fins in long-latency, but not in short-latency C-bends. We also observe fin movements that occur during orienting J-turns and S-starts that drive high-velocity predatory strikes. Finally, we find that the use of pectoral fins following a predatory strike is scaled to the velocity of the strike, supporting a role for the fins in braking. The implications of these results for central control of coordinated movements are discussed, and we hope that these results will provide baselines for future analyses of cross-body coordination using mutants, morphants, and transgenic approaches.

  18. Aerodynamic characteristics of the orbital reentry vehicle experimental probe fins in a supersonic flow

    NASA Astrophysics Data System (ADS)

    Watanabe, Mitsunori; Sekine, Hideo; Tate, Atsushi; Noda, Junichi

    1994-04-01

    The aerodynamic characteristics of probe fins with a sweep angle of 60 deg, which are equipped on the Orbital Reentry Experiment (OREX) vehicle to measure the surrounding ionized gas temperature and electron number density distributions in the high temperature communication black out regions, have been measured in the supersonic wind tunnel of the National Aerospace Laboratory and compared with those of the fins of 0 deg sweep angles. Since the probes are to be embedded in the boundary layer where the local Mach number is less than 2.5 over the OREX surface at a hypersonic flight speed, the aerodynamic characteristics in supersonic regions are needed to estimate the rolling moments of fins caused by the error of the installation angles. The lift coefficient slope of the probe fins decreases as the Mach number increases, being less than the values for the 0 deg sweep fins. The drag coefficient depends highly on the sweep angle of the fins in Mach number regions less than 2.5.

  19. Pool boiling on surfaces with mini-fins and micro-cavities

    NASA Astrophysics Data System (ADS)

    Pastuszko, Robert; Piasecka, Magdalena

    2012-11-01

    The experimental studies presented here focused on pool boiling heat transfer on mini-fin arrays, mini-fins with perforated covering and surfaces with micro-cavities. The experiments were carried out for water and fluorinert FC-72 at atmospheric pressure. Mini-fins of 0.5 and 1 mm in height were uniformly spaced on the base surface. The copper foil with holes of 0.1 mm in diameter (pitch 0.2/0.4 mm), sintered with the fin tips, formed a system of connected perpendicular and horizontal tunnels. The micro-cavities were obtained through spark erosion. The maximal depth of the craters of these cavities was 15 - 30 μm and depended on the parameters of the branding-pen settings. At medium and small heat fluxes, structures with mini-fins showed the best boiling heat transfer performance both for water and FC-72. At medium and high heat fluxes (above 70 kW/m2 for water and 25 kW/m2 for FC-72), surfaces with mini-fins without porous covering and micro-cavities produced the highest heat transfer coefficients. The surfaces obtained with spark erosion require a proper selection of geometrical parameters for particular liquids - smaller diameters of cavities are suitable for liquids with lower surface tension (FC-72).

  20. Line-edge roughness induced single event transient variation in SOI FinFETs

    NASA Astrophysics Data System (ADS)

    Weikang, Wu; Xia, An; Xiaobo, Jiang; Yehua, Chen; Jingjing, Liu; Xing, Zhang; Ru, Huang

    2015-11-01

    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 (Vgs = 0, Vds = Vdd) 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.

  1. Measurement of frost characteristics on heat exchanger fins. Part 1: Test facility and instrumentation

    SciTech Connect

    Thomas, L.; Chen, H.; Besant, R.W.

    1999-07-01

    A special test facility was developed to characterize frost growing on heat exchanger fins where the cold surfaces and the air supply conditions were similar to those experienced in freezers, i.e., cold surface temperatures ranging from {minus}35 C to {minus}40 C, air supply temperatures from {minus}10 C to {minus}20 C, and 80% to 100% relative humidity (RH). This test facility included a test section with removable fins to measure the frost height and mass concentration. Frost height on heat exchanger fins was measured using a new automated laser scanning system to measure the height of frost and its distribution on selected fins. The increase in air pressure loss resulting from frost growth on the fins was measured directly in the test loop. The frost mass accumulation distribution was measured for each test using special pre-etched fins that could be easily subdivided and weighed. The total heat rate was measured using a heat flux meter. These frost-measuring instruments were calibrated and the uncertainty of each is stated.

  2. Indirect adaptive output feedback control of a biorobotic AUV using pectoral-like mechanical fins.

    PubMed

    Naik, Mugdha S; Singh, Sahjendra N; Mittal, Rajat

    2009-06-01

    This paper treats the question of servoregulation of autonomous underwater vehicles (AUVs) in the yaw plane using pectoral-like mechanical fins. The fins attached to the vehicle have oscillatory swaying and yawing motion. The bias angle of the angular motion of the fin is used for the purpose of control. Of course, the design approach considered here is applicable to AUVs for other choices of oscillation patterns of the fins, which produce periodic forces and moments. It is assumed that the vehicle parameters, hydrodynamic coefficients, as well the fin forces and moments are unknown. For the trajectory control of the yaw angle, a sampled-data indirect adaptive control system using output (yaw angle) feedback is derived. The control system has a modular structure, which includes a parameter identifier and a stabilizer. For the control law derivation, an internal model of the exosignals (reference signal (constant or ramp) and constant disturbance) is included. Unlike the direct adaptive control scheme, the derived control law is applicable to minimum as well as nonminimum phase biorobotic AUVs (BAUVs). This is important, because for most of the fin locations on the vehicle, the model is a nonminimum phase. In the closed-loop system, the yaw angle trajectory tracking error converges to zero and the remaining state variables remain bounded. Simulation results are presented which show that the derived modular control system accomplishes precise set point yaw angle control and turning maneuvers in spite of the uncertainties in the system parameters using only yaw angle feedback.

  3. Comparison of rainbow smelt age estimates from fin rays and otoliths

    USGS Publications Warehouse

    Walsh, M.G.; Maloy, A.P.; O'Brien, T. P.

    2008-01-01

    Rainbow smelt Osmerus mordax, although nonnative, are an important component of the offshore food web in the Laurentian Great Lakes. In Lake Ontario, we estimate ages of rainbow smelt annually to study population dynamics such as year-class strength and age-specific growth and mortality. Since the early 1980s, we have used pectoral fin rays to estimate rainbow smelt ages, but the sectioning and mounting of fin rays are time and labor intensive. Our objective was to assess the feasibility of using otoliths rather than fin rays to estimate rainbow smelt ages. Three readers interpreted the ages of 172 rainbow smelt (60-198 mm total length) based on thin sections of pectoral fin rays, whole otoliths with no preparation, and whole otoliths that had been cleared for 1 month in a 70:30 ethanol : glycerin solution. Bias was lower and precision was greater for fin rays than for otoliths; these results were consistent for comparisons within readers (first and second readings by one individual; three readers were used) and between readers (one reading for each reader within a pair). Both otolith methods appeared to misclassify age-1 rainbow smelt. Fin ray ages had the highest precision and provided the best approximation of age estimates inferred from the Lake Ontario population's length frequency distribution and from our understanding of this population. ?? American Fisheries Society 2008.

  4. Resolution of ray-finned fish phylogeny and timing of diversification.

    PubMed

    Near, Thomas J; Eytan, Ron I; Dornburg, Alex; Kuhn, Kristen L; Moore, Jon A; Davis, Matthew P; Wainwright, Peter C; Friedman, Matt; Smith, W Leo

    2012-08-21

    Ray-finned fishes make up half of all living vertebrate species. Nearly all ray-finned fishes are teleosts, which include most commercially important fish species, several model organisms for genomics and developmental biology, and the dominant component of marine and freshwater vertebrate faunas. Despite the economic and scientific importance of ray-finned fishes, the lack of a single comprehensive phylogeny with corresponding divergence-time estimates has limited our understanding of the evolution and diversification of this radiation. Our analyses, which use multiple nuclear gene sequences in conjunction with 36 fossil age constraints, result in a well-supported phylogeny of all major ray-finned fish lineages and molecular age estimates that are generally consistent with the fossil record. This phylogeny informs three long-standing problems: specifically identifying elopomorphs (eels and tarpons) as the sister lineage of all other teleosts, providing a unique hypothesis on the radiation of early euteleosts, and offering a promising strategy for resolution of the "bush at the top of the tree" that includes percomorphs and other spiny-finned teleosts. Contrasting our divergence time estimates with studies using a single nuclear gene or whole mitochondrial genomes, we find that the former underestimates ages of the oldest ray-finned fish divergences, but the latter dramatically overestimates ages for derived teleost lineages. Our time-calibrated phylogeny reveals that much of the diversification leading to extant groups of teleosts occurred between the late Mesozoic and early Cenozoic, identifying this period as the "Second Age of Fishes."

  5. A comparison of pectoral fin contact behaviour for three distinct dolphin populations.

    PubMed

    Dudzinski, Kathleen M; Gregg, Justin D; Paulos, Robin D; Kuczaj, Stan A

    2010-06-01

    Tactile exchanges involving the pectoral fin have been documented in a variety of dolphin species. Several functions (e.g., social, hygienic) have been offered as possible explanations for when and why dolphins exchange pectoral fin contacts. In this study, we compared pectoral fin contact between dolphin dyads from three distinct dolphin populations: two groups of wild dolphins; Atlantic spotted dolphins (Stenella frontalis) from The Bahamas and Indo-Pacific bottlenose dolphins (Tursiops aduncus) from around Mikura Island, Japan; and one group of captive bottlenose dolphins (Tursiops truncatus) residing at the Roatan Institute for Marine Sciences, Anthony's Key Resort. A number of similarities were observed between the captive and wild groups, including; rates of pectoral fin contact, which dolphin initiated contact, posture preference, and same-sex rubbing partner preference. Unlike their wild counterparts, however, dolphins in the captive study group engaged in petting and rubbing at equal rates, females were more likely to contact males, males assumed the various rubbing roles more frequently than females, and calves and juveniles were more likely to be involved in pectoral fin contact exchanges. These results suggest that some aspects of pectoral fin contact behaviour might be common to many dolphin species, whereas other aspects could be species specific, or could be the result of differing environmental and social conditions.

  6. A novel mini-DNA barcoding assay to identify processed fins from internationally protected shark species.

    PubMed

    Fields, Andrew T; Abercrombie, Debra L; Eng, Rowena; Feldheim, Kevin; Chapman, Demian D

    2015-01-01

    There is a growing need to identify shark products in trade, in part due to the recent listing of five commercially important species on the Appendices of the Convention on International Trade in Endangered Species (CITES; porbeagle, Lamna nasus, oceanic whitetip, Carcharhinus longimanus scalloped hammerhead, Sphyrna lewini, smooth hammerhead, S. zygaena and great hammerhead S. mokarran) in addition to three species listed in the early part of this century (whale, Rhincodon typus, basking, Cetorhinus maximus, and white, Carcharodon carcharias). Shark fins are traded internationally to supply the Asian dried seafood market, in which they are used to make the luxury dish shark fin soup. Shark fins usually enter international trade with their skin still intact and can be identified using morphological characters or standard DNA-barcoding approaches. Once they reach Asia and are traded in this region the skin is removed and they are treated with chemicals that eliminate many key diagnostic characters and degrade their DNA ("processed fins"). Here, we present a validated mini-barcode assay based on partial sequences of the cytochrome oxidase I gene that can reliably identify the processed fins of seven of the eight CITES listed shark species. We also demonstrate that the assay can even frequently identify the species or genus of origin of shark fin soup (31 out of 50 samples).

  7. Parametric study of propeller boss cap fins for container ships

    NASA Astrophysics Data System (ADS)

    Lim, Sang-Seop; Kim, Tae-Won; Lee, Dong-Myung; Kang, Chung-Gil; Kim, Soo-Young

    2014-06-01

    The global price of oil, which is both finite and limited in quantity, has been rising steadily because of the increasing requirements for energy in both developing and developed countries. Furthermore, regulations have been strengthened across all industries to address global warming. Many studies of hull resistance, propulsion and operation of ships have been performed to reduce fuel consumption and emissions. This study examined the design parameters of the propeller boss cap fin (PBCF) and hub cap for 6,000TEU container ships to improve the propulsion efficiency. The design parameters of PBCF have been selected based on the geometrical shape. Computational fluid dynamics (CFD) analysis with a propeller open water (POW) test was performed to check the validity of CFD analysis. The design of experiment (DOE) case was selected as a full factorial design, and the experiment was analyzed by POW and CFD analysis. Analysis of variance (ANOVA) was performed to determine the correlation among design parameters. Four design alternatives of PBCF were selected from the DOE. The shape of a propeller hub cap was selected as a divergent shape, and the divergent angle was determined by the DOE. Four design alternatives of PBCF were attached to the divergent hub cap, and the POW was estimated by CFD. As a result, the divergent hub cap with PBCF has a negative effect on the POW, which is induced by an increase in torque coefficient. A POW test and cavitation test were performed with a divergent hub cap with PBCF to verify the CFD result. The POW test result showed that the open water efficiency was increased approximately 2% with a divergent hub cap compared to a normal cap. The POW test result was similar to the CFD result, and the divergent hub cap with the PBCF models showed lower open water efficiency. This was attributed to an increase in the torque coefficient just like the CFD results. A cavitation test was performed using the 2 models selected. The test result showed

  8. Formation of SiN Films by Plazma-Enhanced Chemical Vapor Deposition Using [(CH3)2N]3SiN3

    NASA Astrophysics Data System (ADS)

    Kitoh, Hideyuki; Muroyama, Masakazu

    1994-12-01

    An organic source gas, tris-dimethyl-amino-silyl-azide (TDSA, [(CH3)2N]3SiN3), was newly synthesized and utilized for the deposition of a passivation film of sub-half-micrometer devices. Deposition temperature dependence of the film formed by plasma-enhanced chemical vapor deposition (PECVD) using TDSA was investigated and step coverage of the TDSA film was examined. As a result, it was clarified that hydrocarbon content in the film decreased with increasing deposition temperature. The bottom step coverage of the films formed using TDSA was greatly improved compared to that of the conventional silicon nitride film.

  9. Ten Sins Challenging Education in the Contemporary Global Era: A Philosophical Essay

    ERIC Educational Resources Information Center

    Sinagatullin, Ilghiz M.

    2004-01-01

    According to this author, the modern epoch is characterized by a decrease of vital spirituality and an increase of materialistic values and virtues. This article discusses what the author views as the ten sins challenging education in the contemporary global era. These are: (1) the shrinking of spiritual values; (2) corruption; (3) sexual…

  10. How Secondary Schools Can Avoid the Seven Deadly School "Sins" of Inclusion

    ERIC Educational Resources Information Center

    Worrell, Jamie L.

    2008-01-01

    As more students with disabilities are included in general education classrooms, many obstacles must be overcome before parents, teachers, students, and administrators deem inclusion effective. This article identifies seven "sins", which are barriers to inclusive practices in secondary schools: Negative teacher perspectives; lack of knowledge…

  11. Sin Fronteras Boy: Students Create Collaborative Websites to Explore the Border

    ERIC Educational Resources Information Center

    Cornell, Grace

    2012-01-01

    Around one table, four 4th-grade girls chat quietly as they write on their laptops: Ruby interviews Alejandra about her experience crossing the U.S.-Mexico border as a 6-year-old. Meanwhile, Cindy turns notes from an interview with her uncle into a narrative about his immigration experience. Next to them, four boys work on the "Sin Fronteras…

  12. Plagiarism and Other Sins Seem Rife in Science Journals, a Digital Sleuth Finds

    ERIC Educational Resources Information Center

    Guterman, Lila

    2008-01-01

    Faculty members gnash their teeth and wring their hands when students plagiarize. They cry for offenders to be punished. But now an online text-search program directed at their own work suggests that professors in biomedicine may be just as guilty of paper-writing sins. More than 70,000 article abstracts appeared disturbingly similar to other…

  13. Roots of Sin and Destruction of the Religious Education in the Shia Belief

    ERIC Educational Resources Information Center

    Sadeghiyan, Mehri

    2016-01-01

    The religious Education is one of the key components of the present age detachment from which poses numerous problems for the society Islamic. One of the factors effective in the destruction of the religious Education is the roots of sin avoiding which can lead to the improvement of the religious Education of the members of the society. Thus, the…

  14. Speed-dependent intrinsic caudal fin muscle recruitment during steady swimming in bluegill sunfish, Lepomis macrochirus.

    PubMed

    Flammang, Brooke E; Lauder, George V

    2008-02-01

    There are approximately 50 muscles that control tail fin shape in most teleost fishes, and although myotomal muscle function has been extensively studied, little work has been done on the intrinsic musculature that controls and shapes the tail. In this study we measured electrical activity in intrinsic tail musculature to determine if these muscles are active during steady rectilinear locomotion, and to compare intrinsic muscle recruitment patterns to previous data on myotomal muscle fibers. Five bluegill sunfish (Lepomis macrochirus) were anaesthetized and electrode wires surgically placed into a total of 24 intrinsic caudal muscles, up to 13 at a time, and activity was correlated with synchronous recordings from myotomal fibers in the caudal peduncle. After recovery, fish swam steadily at speeds of 0.5, 1.2 and 2.0 L s(-1), while filmed from lateral, posterior and ventral views simultaneously at 250 frames s(-1). Comparison among speeds confirmed that muscle recruitment varies significantly with speed. At 0.5 L s(-1), the caudal fin was generally not used for propulsion, and swimming was accomplished primarily through body undulations. Intrinsic caudal muscle activity at this speed was intermittent and variable. At 1.2 and 2.0 L s(-1), the supracarinalis and infracarinalis muscles acted on the dorsal- and ventral-most fin rays, respectively, to expand the surface area of the caudal fin. The interradialis muscles adducted individual fin rays, dorsally to ventrally, following activation of the hypochordal longitudinalis. Contralateral muscle activity of interradialis muscles occurred as the caudal fin crossed the mean direction of travel and fin height was greatest, whereas ipsilateral activity of carinalis muscles occurred near points of maximum excursion of the fin, at speeds of 1.2 and 2.0 L s(-1), after fin height was lowest. Burst intensity increased with swimming speed, suggesting stiffening of the tail fin against imposed hydrodynamic loads. Activity

  15. Energetics of median and paired fin swimming, body and caudal fin swimming, and gait transition in parrotfish (Scarus schlegeli) and triggerfish (Rhinecanthus aculeatus).

    PubMed

    Korsmeyer, Keith E; Steffensen, John Fleng; Herskin, Jannik

    2002-05-01

    To determine the energetic costs of rigid-body, median or paired-fin (MPF) swimming versus undulatory, body-caudal fin (BCF) swimming, we measured oxygen consumption as a function of swimming speed in two MPF swimming specialists, Schlegel's parrotfish and Picasso triggerfish. The parrotfish swam exclusively with the pectoral fins at prolonged swimming speeds up to 3.2 total lengths per second (L s(-1); 30 min critical swimming speed, U(crit)). At higher speeds, gait transferred to a burst-and-coast BCF swimming mode that resulted in rapid fatigue. The triggerfish swam using undulations of the soft dorsal and anal fins up to 1.5 L s(-1), beyond which BCF undulations were recruited intermittently. BCF swimming was used continuously above 3.5 L s(-1), and was accompanied by synchronous undulations of the dorsal and anal fins. The triggerfish were capable of high, prolonged swimming speeds of up to 4.1 L s(-1) (30 min U(crit)). In both species, the rates of increase in oxygen consumption with swimming speed were higher during BCF swimming than during rigid-body MPF swimming. Our results indicate that, for these species, undulatory swimming is energetically more costly than rigid-body swimming, and therefore support the hypothesis that MPF swimming is more efficient. In addition, use of the BCF gait at higher swimming speed increased the cost of transport in both species beyond that predicted for MPF swimming at the same speeds. This suggests that, unlike for terrestrial locomotion, gait transition in fishes does not occur to reduce energetic costs, but to increase recruitable muscle mass and propulsive surfaces. The appropriate use of the power and exponential functions to model swimming energetics is also discussed.

  16. Biomechanical model of batoid (skates and rays) pectoral fins predicts the influence of skeletal structure on fin kinematics: implications for bio-inspired design.

    PubMed

    Russo, R S; Blemker, S S; Fish, F E; Bart-Smith, H

    2015-06-16

    Growing interest in the development of bio-inspired autonomous underwater vehicles (AUVs) has motivated research in understanding the mechanisms behind the propulsion systems of marine animals. For example, the locomotive behavior of rays (Batoidea) by movement of the pectoral fins is of particular interest due to their superior performance characteristics over contemporary AUV propulsion systems. To better understand the mechanics of pectoral fin propulsion, this paper introduces a biomechanical model that simulates how batoid skeletal structures function to achieve the swimming locomotion observed in nature. Two rays were studied, Dasyatis sabina (Atlantic ray), and Rhinoptera bonasus (cownose ray). These species were selected because they exhibit very different swimming styles (undulation versus oscillation), but all use primarily their pectoral fins for propulsion (unlike electric rays or guitarfishes). Computerized tomography scans of each species were taken to image the underlying structure, which reveal a complex system of cartilaginous joints and linkages. Data collected from these images were used to quantify the complete skeletal morphometry of each batoid fin. Morphological differences were identified in the internal cartilage arrangement between each species including variations in the orientation of the skeletal elements, or radials, and the joint patterns between them, called the inter-radial joint pattern. These data were used as the primary input into the biomechanical model to couple a given ray skeletal structure with various swimming motions. A key output of the model is an estimation of the uniaxial strain that develops in the skeletal connective tissue in order for the structure to achieve motions observed during swimming. Tensile load tests of this connective tissue were conducted to further investigate the implications of the material strain predictions. The model also demonstrates that changes in the skeletal architecture (e.g., joint

  17. Three-dimensional numerical simulation of hydrodynamic interactions between pectoral-fin vortices and body undulation in a swimming fish

    NASA Astrophysics Data System (ADS)

    Yu, Cheng-Lun; Ting, Shang-Chieh; Yeh, Meng-Kao; Yang, Jing-Tang

    2011-09-01

    We investigated numerically the hydrodynamic interactions between pectoral-fin vortices and body undulation in a fish swimming with carangiform locomotion at a Reynolds number of 3.3 × 104; the three-dimensional, viscous, incompressible, Navier-Stokes equations were solved with a finite-volume method. For a fish swimming with the pectoral fins abducted, we characterized the wake flow structures, forces, and power consumption with respect to various Strouhal numbers. The numerical results reveal that a pair of vortices is formed immediately behind the abducted pectoral fins of a swimming fish. There exist hydrodynamic interactions between the pectoral-fin vortices and the undulating fish body. For Strouhal numbers in a range 0.2-0.8, the body undulation impedes the shedding of pectoral-fin vortices, resulting in vortices closely attached to the pectoral fins. In contrast, for Strouhal number = 0.1, the pectoral-fin vortices are shed from the pectoral fins and drift downstream. The low-pressure suction forces arising from the shed pectoral-fin vortices facilitate lateral movements of the fish body, decreasing the power consumption. This phenomenon indicates the possibility for an actual fish to harvest energy from the shed pectoral-fin vortices.

  18. Anatomy and muscle activity of the dorsal fins in bamboo sharks and spiny dogfish during turning maneuvers.

    PubMed

    Maia, Anabela; Wilga, Cheryl D

    2013-11-01

    Stability and procured instability characterize two opposing types of swimming, steady and maneuvering, respectively. Fins can be used to manipulate flow to adjust stability during swimming maneuvers either actively using muscle control or passively by structural control. The function of the dorsal fins during turning maneuvering in two shark species with different swimming modes is investigated here using musculoskeletal anatomy and muscle function. White-spotted bamboo sharks are a benthic species that inhabits complex reef habitats and thus have high requirements for maneuverability. Spiny dogfish occupy a variety of coastal and continental shelf habitats and spend relatively more time cruising in open water. These species differ in dorsal fin morphology and fin position along the body. Bamboo sharks have a larger second dorsal fin area and proportionally more muscle insertion into both dorsal fins. The basal and radial pterygiophores are plate-like structures in spiny dogfish and are nearly indistinguishable from one another. In contrast, bamboo sharks lack basal pterygiophores, while the radial pterygiophores form two rows of elongated rectangular elements that articulate with one another. The dorsal fin muscles are composed of a large muscle mass that extends over the ceratotrichia overlying the radials in spiny dogfish. However, in bamboo sharks, the muscle mass is divided into multiple distinct muscles that insert onto the ceratotrichia. During turning maneuvers, the dorsal fin muscles are active in both species with no differences in onset between fin sides. Spiny dogfish have longer burst durations on the outer fin side, which is consistent with opposing resistance to the medium. In bamboo sharks, bilateral activation of the dorsal in muscles could also be stiffening the fin throughout the turn. Thus, dogfish sharks passively stiffen the dorsal fin structurally and functionally, while bamboo sharks have more flexible dorsal fins, which result from a

  19. Annual Acoustic Presence of Fin Whale (Balaenoptera physalus) Offshore Eastern Sicily, Central Mediterranean Sea.

    PubMed

    Sciacca, Virginia; Caruso, Francesco; Beranzoli, Laura; Chierici, Francesco; De Domenico, Emilio; Embriaco, Davide; Favali, Paolo; Giovanetti, Gabriele; Larosa, Giuseppina; Marinaro, Giuditta; Papale, Elena; Pavan, Gianni; Pellegrino, Carmelo; Pulvirenti, Sara; Simeone, Francesco; Viola, Salvatore; Riccobene, Giorgio

    2015-01-01

    In recent years, an increasing number of surveys have definitively confirmed the seasonal presence of fin whales (Balaenoptera physalus) in highly productive regions of the Mediterranean Sea. Despite this, very little is yet known about the routes that the species seasonally follows within the Mediterranean basin and, particularly, in the Ionian area. The present study assesses for the first time fin whale acoustic presence offshore Eastern Sicily (Ionian Sea), throughout the processing of about 10 months of continuous acoustic monitoring. The recording of fin whale vocalizations was made possible by the cabled deep-sea multidisciplinary observatory, "NEMO-SN1", deployed 25 km off the Catania harbor at a depth of about 2,100 meters. NEMO-SN1 is an operational node of the European Multidisciplinary Seafloor and water-column Observatory (EMSO) Research Infrastructure. The observatory was equipped with a low-frequency hydrophone (bandwidth: 0.05 Hz-1 kHz, sampling rate: 2 kHz) which continuously acquired data from July 2012 to May 2013. About 7,200 hours of acoustic data were analyzed by means of spectrogram display. Calls with the typical structure and patterns associated to the Mediterranean fin whale population were identified and monitored in the area for the first time. Furthermore, a background noise analysis within the fin whale communication frequency band (17.9-22.5 Hz) was conducted to investigate possible detection-masking effects. The study confirms the hypothesis that fin whales are present in the Ionian Sea throughout all seasons, with peaks in call detection rate during spring and summer months. The analysis also demonstrates that calls were more frequently detected in low background noise conditions. Further analysis will be performed to understand whether observed levels of noise limit the acoustic detection of the fin whales vocalizations, or whether the animals vocalize less in the presence of high background noise.

  20. Early evolution of the lungfish pectoral fin endoskeleton: evidence from the Middle Devonian (Givetian) Pentlandia macroptera

    NASA Astrophysics Data System (ADS)

    Jude, Emma; Johanson, Zerina; Kearsley, Anton; Friedman, Matt

    2014-08-01

    As the closest living relatives of tetrapods, lungfishes are frequently used as extant models for exploring the fin-to-limb transition. These studies have generally given little consideration to fossil taxa. This is because although lungfish fins are relatively common in the fossil record, the internal structure of these fins is virtually unknown. Information on pectoral-fin endoskeletons in fossil representatives of Dipnomorpha (the lungfish total group) is limited to poorly preserved remains in the lungfish Dipterus and Conchopoma and more complete material in the porolepiform Glyptolepis. Here we describe a well-preserved pectoral-fin endoskeleton in the Middle Devonian (Givetian) lungfish Pentlandia macroptera from the John O’Groats fish bed, Caithness, northeastern Scotland. The skeleton is in association with a cleithrum and clavicle, and consists of a series of at least eight mesomeres. Extensive series of preaxial and postaxial radials are present. Some of the radials are jointed, but none branch. No mesomere articulates with multiple radials on either its pre- or post-axial face. The first two mesomeres, corresponding to the humerus and ulna, bear well-developed axial processes. Uniquely among dipnomorphs, a distinct ossification centre corresponding to the radius is present in Pentlandia. A review of anatomy and development of the pectoral-fin endoskeleton in the living Neoceratodus is presented based on cleared and stained material representing different size stages. These developmental data, in conjunction with new details of primitive lungfish conditions based on Pentlandia, highlight many of the derived features of the pectoral-fin skeleton of Neoceratodus, and clarify patterns of appendage evolution within the dipnomorphs more generally.

  1. Annual Acoustic Presence of Fin Whale (Balaenoptera physalus) Offshore Eastern Sicily, Central Mediterranean Sea

    PubMed Central

    Sciacca, Virginia; Caruso, Francesco; Beranzoli, Laura; Chierici, Francesco; De Domenico, Emilio; Embriaco, Davide; Favali, Paolo; Giovanetti, Gabriele; Larosa, Giuseppina; Marinaro, Giuditta; Papale, Elena; Pavan, Gianni; Pellegrino, Carmelo; Pulvirenti, Sara; Simeone, Francesco; Viola, Salvatore; Riccobene, Giorgio

    2015-01-01

    In recent years, an increasing number of surveys have definitively confirmed the seasonal presence of fin whales (Balaenoptera physalus) in highly productive regions of the Mediterranean Sea. Despite this, very little is yet known about the routes that the species seasonally follows within the Mediterranean basin and, particularly, in the Ionian area. The present study assesses for the first time fin whale acoustic presence offshore Eastern Sicily (Ionian Sea), throughout the processing of about 10 months of continuous acoustic monitoring. The recording of fin whale vocalizations was made possible by the cabled deep-sea multidisciplinary observatory, “NEMO-SN1”, deployed 25 km off the Catania harbor at a depth of about 2,100 meters. NEMO-SN1 is an operational node of the European Multidisciplinary Seafloor and water-column Observatory (EMSO) Research Infrastructure. The observatory was equipped with a low-frequency hydrophone (bandwidth: 0.05 Hz–1 kHz, sampling rate: 2 kHz) which continuously acquired data from July 2012 to May 2013. About 7,200 hours of acoustic data were analyzed by means of spectrogram display. Calls with the typical structure and patterns associated to the Mediterranean fin whale population were identified and monitored in the area for the first time. Furthermore, a background noise analysis within the fin whale communication frequency band (17.9–22.5 Hz) was conducted to investigate possible detection-masking effects. The study confirms the hypothesis that fin whales are present in the Ionian Sea throughout all seasons, with peaks in call detection rate during spring and summer months. The analysis also demonstrates that calls were more frequently detected in low background noise conditions. Further analysis will be performed to understand whether observed levels of noise limit the acoustic detection of the fin whales vocalizations, or whether the animals vocalize less in the presence of high background noise. PMID:26581104

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

    PubMed

    O'Bryhim, Jason R; Adams, Douglas H; Spaet, Julia L Y; Mills, Gary; Lance, Stacey L

    2017-04-01

    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.

  3. A Theoretical Study of Steady State and Transient Condensation on Axisymmetric Fins Under Combined Capillary and Gravitational Forces

    NASA Astrophysics Data System (ADS)

    Kostoglou, M.; Karapantsios, T. D.; Buffone, C.; Glushchuk, A.; Iorio, C.

    2016-10-01

    The present work attempts to model the case of combined gravitational and capillary motion of condensate for an axisymmetric fin under steady and transient fin operation conditions. The focus here is to examine the structure of the mathematical problem and to develop suitable numerical techniques rather than yield information on the macroscopic condensate flow rate and fin efficiency. The problem is formulated starting from general conditions and is simplified step by step by introducing corresponding assumptions. The particular fin shape of a paraboloid from revolution is chosen and the equations are properly non-dimensionalized. A vast reduction of the number of problem parameters is achieved in this way. The cases of isothermal fin, steady state operation and dynamic operation are treated separately using specialized numerical solution techniques developed for each case in order to improve computational efficiency and accuracy. Typical results of fin temperature and condensate film thickness are presented and discussed.

  4. Three-Dimensional Numerical Analysis of Laminar Heat Exchanger with Respect to Fin Shape and Fan Performance

    NASA Astrophysics Data System (ADS)

    Park, S. M.; Kim, J. Y.; Seol, S. S.; Lee, D. J.; Lee, M. C.

    2010-06-01

    The performances of the fin-and-tube heat exchangers with wavy or plain fins were numerically investigated using a commercial code based on the finite volume method implementing SIMPLE algorithm. The relations among the heat transfer performance, pressure and the fin shape were taken into consideration with the performance characteristic of the fan installed in the real heat exchanger. Generally, a heat exchanger with wavy fins shows better performance than that with plain fins under the same air flow rate. However, the performance of a heat exchanger was mainly affected by the performance characteristics of the installed fans. In case that a fan whose air flow rate remarkably changes by the minor pressure variation, the performance characteristic of the fan was much more important than the fin shape with respect to heat transfer rate. This is attributed to the fact that the air flow rates of fans were varied with the pressure loss of the heat exchanger.

  5. The effect of diet on dorsal fin erosion in steelhead trout (Oncorhynchus mykiss)

    USGS Publications Warehouse

    Lellis, W.A.; Barrows, F.T.

    1997-01-01

    A 2 X 2 factorial experiment of diet type (krill vs. fish meal) and steroid supplementation (0 vs. 30 ??g 17??-methyltestosterone kg-1) was conducted to determine the effects on dorsal fin erosion in steelhead trout. Triplicate tanks of 250 fry were fed one of the four diets at a rate calculated to produce 115 g fish in 34 weeks. Fish were transferred to larger tanks when mean density index reached 0.40. Dorsal fin index (DFI, measured as mean dorsal fin height X 100/total fish length) was greater (P < 0.001) among fish fed krill-based diets than for fish fed fish-based diets at weeks 12, 22, and 34 of the trial. Added testosterone decreased (p = 0.04) DFI among fish fed the krill diet at week 12 but otherwise had no effect on fin condition. Addition of testosterone to either diet type decreased (P = 0.02) critical thermal maximum, which is a measure of fish resistance to thermal stress. The results suggest that diet composition can influence the rate of dorsal fin erosion in steelhead trout through a metabolic, behavioral, or combined change.

  6. The fin-to-limb transition as the re-organization of a Turing pattern.

    PubMed

    Onimaru, Koh; Marcon, Luciano; Musy, Marco; Tanaka, Mikiko; Sharpe, James

    2016-05-23

    A Turing mechanism implemented by BMP, SOX9 and WNT has been proposed to control mouse digit patterning. However, its generality and contribution to the morphological diversity of fins and limbs has not been explored. Here we provide evidence that the skeletal patterning of the catshark Scyliorhinus canicula pectoral fin is likely driven by a deeply conserved Bmp-Sox9-Wnt Turing network. In catshark fins, the distal nodular elements arise from a periodic spot pattern of Sox9 expression, in contrast to the stripe pattern in mouse digit patterning. However, our computer model shows that the Bmp-Sox9-Wnt network with altered spatial modulation can explain the Sox9 expression in catshark fins. Finally, experimental perturbation of Bmp or Wnt signalling in catshark embryos produces skeletal alterations which match in silico predictions. Together, our results suggest that the broad morphological diversity of the distal fin and limb elements arose from the spatial re-organization of a deeply conserved Turing mechanism.

  7. Sounds from airguns and fin whales recorded in the mid-Atlantic Ocean, 1999-2009.

    PubMed

    Nieukirk, Sharon L; Mellinger, David K; Moore, Sue E; Klinck, Karolin; Dziak, Robert P; Goslin, Jean

    2012-02-01

    Between 1999 and 2009, autonomous hydrophones were deployed to monitor seismic activity from 16° N to 50° N along the Mid-Atlantic Ridge. These data were examined for airgun sounds produced during offshore surveys for oil and gas deposits, as well as the 20 Hz pulse sounds from fin whales, which may be masked by airgun noise. An automatic detection algorithm was used to identify airgun sound patterns, and fin whale calling levels were summarized via long-term spectral analysis. Both airgun and fin whale sounds were recorded at all sites. Fin whale calling rates were higher at sites north of 32° N, increased during the late summer and fall months at all sites, and peaked during the winter months, a time when airgun noise was often prevalent. Seismic survey vessels were acoustically located off the coasts of three major areas: Newfoundland, northeast Brazil, and Senegal and Mauritania in West Africa. In some cases, airgun sounds were recorded almost 4000 km from the survey vessel in areas that are likely occupied by fin whales, and at some locations airgun sounds were recorded more than 80% days/month for more than 12 consecutive months.

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

    PubMed Central

    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 2.86 days and were quicker compared with that in the UV only group (4.21 days); (2) zebrafish fins in the UV+comfrey (50 and 100 ppm) groups were 2.05 and 3.25 times more likely to return to normal than those in the UV only group; and (3) comfrey leave extracts had UV-absorbance abilities and significantly reduced ROS production in UV-exposed zebrafish embryos, which may attenuate UV-mediated apoptosis. In conclusion, comfrey leaves extracts may have the potential to be developed as UV-protective agents to protect zebrafish embryos from UV-induced damage. PMID:25352712

  9. Age-dependent decline in fin regenerative capacity in the short-lived fish Nothobranchius furzeri

    PubMed Central

    Wendler, Sebastian; Hartmann, Nils; Hoppe, Beate; Englert, Christoph

    2015-01-01

    The potential to regenerate declines with age in a wide range of organisms. A popular model system to study the mechanisms of regeneration is the fin of teleost fish, which has the ability to fully regrow upon amputation. Here, we used the short-lived killifish Nothobranchius furzeri to analyse the impact of aging on fin regeneration in more detail. We observed that young fish were able to nearly completely (98%) regenerate their amputated caudal fins within 4 weeks, whereas middle-aged fish reached 78%, old fish 57% and very old fish 46% of their original fin size. The difference in growth rate between young and old fish was already significant at 3 days post amputation (dpa) and increased with time. We therefore hypothesized that early events are crucial for the age-related differences in regenerative capacity. Indeed, we could observe a higher percentage of proliferating cells in early regenerating fin tissue of young fish compared with aged fish and larger fractions of apoptotic cells in aged fish. Furthermore, young fish showed peak upregulation of several genes involved in fgf and wnt/β-catenin signalling at an earlier time point than old fish. Our findings suggest that regenerative processes are initiated earlier and that regeneration overall is more efficient in younger fish. PMID:26121607

  10. Age-dependent decline in fin regenerative capacity in the short-lived fish Nothobranchius furzeri.

    PubMed

    Wendler, Sebastian; Hartmann, Nils; Hoppe, Beate; Englert, Christoph

    2015-10-01

    The potential to regenerate declines with age in a wide range of organisms. A popular model system to study the mechanisms of regeneration is the fin of teleost fish, which has the ability to fully regrow upon amputation. Here, we used the short-lived killifish Nothobranchius furzeri to analyse the impact of aging on fin regeneration in more detail. We observed that young fish were able to nearly completely (98%) regenerate their amputated caudal fins within 4 weeks, whereas middle-aged fish reached 78%, old fish 57% and very old fish 46% of their original fin size. The difference in growth rate between young and old fish was already significant at 3 days post amputation (dpa) and increased with time. We therefore hypothesized that early events are crucial for the age-related differences in regenerative capacity. Indeed, we could observe a higher percentage of proliferating cells in early regenerating fin tissue of young fish compared with aged fish and larger fractions of apoptotic cells in aged fish. Furthermore, young fish showed peak upregulation of several genes involved in fgf and wnt/β-catenin signalling at an earlier time point than old fish. Our findings suggest that regenerative processes are initiated earlier and that regeneration overall is more efficient in younger fish.

  11. Mixed convection flow of nanofluid in a square enclosure with an intruded rectangular fin

    NASA Astrophysics Data System (ADS)

    Cong, Ran; Zhou, Xuanyu; De Souza Machado, Bruno; Das, Prodip K.

    2016-07-01

    Mixed convection flow in enclosures has been a subject of interest for many years due to their ever increasing applications in solar collectors, electronic cooling, lubrication technologies, food processing, and nuclear reactors. In comparison, little effort has been given to the problem of mixed convection in enclosures filled with nanofluids, while the addition of nanoparticles in a fluid base to alter specific material properties is considered a feasible solution for many heat transfer problems. Mixed convection of nanofluids is a challenging problem as the addition of nanoparticles changes the fluid's thermo-physical properties as well as due to the complex interactions among inertia, viscous, and buoyancy forces. In this study, a two-dimensional steady-state numerical model has been developed to investigate mixed convection flow of nanofluids in a square enclosure with an intruded rectangular fin and to optimize the fin geometry for maximizing the heat transfer using the Constructal design. The model has been developed using ANSYS-FLUENT for various fin geometries. Flow fields, temperature fields, and heat transfer rates are examined for different values of Rayleigh and Reynolds numbers for several geometries of the fin with the aim of maximizing the heat transfer from the fin to the surrounding flow. Outcome of this study provides important insight into the heat transfer behavior of nanofluids, which will help in developing novel geometries with enhanced and controlled heat transfer for solar collectors and electronic devices.

  12. Blue and fin whale call source levels and propagation range in the Southern Ocean.

    PubMed

    Sirović, Ana; Hildebrand, John A; Wiggins, Sean M

    2007-08-01

    Blue (Balaenoptera musculus) and fin whales (B. physalus) produce high-intensity, low-frequency calls, which probably function for communication during mating and feeding. The source levels of blue and fin whale calls off the Western Antarctic Peninsula were calculated using recordings made with calibrated, bottom-moored hydrophones. Blue whales were located up to a range of 200 km using hyperbolic localization and time difference of arrival. The distance to fin whales, estimated using multipath arrivals of their calls, was up to 56 km. The error in range measurements was 3.8 km using hyperbolic localization, and 3.4 km using multipath arrivals. Both species produced high-intensity calls; the average blue whale call source level was 189+/-3 dB re:1 microPa-1 m over 25-29 Hz, and the average fin whale call source level was 189+/-4 dB re:1 microPa-1 m over 15-28 Hz. Blue and fin whale populations in the Southern Ocean have remained at low numbers for decades since they became protected; using source level and detection range from passive acoustic recordings can help in calculating the relative density of calling whales.

  13. The fin-to-limb transition as the re-organization of a Turing pattern

    PubMed Central

    Onimaru, Koh; Marcon, Luciano; Musy, Marco; Tanaka, Mikiko; Sharpe, James

    2016-01-01

    A Turing mechanism implemented by BMP, SOX9 and WNT has been proposed to control mouse digit patterning. However, its generality and contribution to the morphological diversity of fins and limbs has not been explored. Here we provide evidence that the skeletal patterning of the catshark Scyliorhinus canicula pectoral fin is likely driven by a deeply conserved Bmp–Sox9–Wnt Turing network. In catshark fins, the distal nodular elements arise from a periodic spot pattern of Sox9 expression, in contrast to the stripe pattern in mouse digit patterning. However, our computer model shows that the Bmp–Sox9–Wnt network with altered spatial modulation can explain the Sox9 expression in catshark fins. Finally, experimental perturbation of Bmp or Wnt signalling in catshark embryos produces skeletal alterations which match in silico predictions. Together, our results suggest that the broad morphological diversity of the distal fin and limb elements arose from the spatial re-organization of a deeply conserved Turing mechanism. PMID:27211489

  14. Evolutionary multiobjective design of a flexible caudal fin for robotic fish.

    PubMed

    Clark, Anthony J; Tan, Xiaobo; McKinley, Philip K

    2015-11-25

    Robotic fish accomplish swimming by deforming their bodies or other fin-like appendages. As an emerging class of embedded computing system, robotic fish are anticipated to play an important role in environmental monitoring, inspection of underwater structures, tracking of hazardous wastes and oil spills, and the study of live fish behaviors. While integration of flexible materials (into the fins and/or body) holds the promise of improved swimming performance (in terms of both speed and maneuverability) for these robots, such components also introduce significant design challenges due to the complex material mechanics and hydrodynamic interactions. The problem is further exacerbated by the need for the robots to meet multiple objectives (e.g., both speed and energy efficiency). In this paper, we propose an evolutionary multiobjective optimization approach to the design and control of a robotic fish with a flexible caudal fin. Specifically, we use the NSGA-II algorithm to investigate morphological and control parameter values that optimize swimming speed and power usage. Several evolved fin designs are validated experimentally with a small robotic fish, where fins of different stiffness values and sizes are printed with a multi-material 3D printer. Experimental results confirm the effectiveness of the proposed design approach in balancing the two competing objectives.

  15. Observation and understanding of anisotropic strain relaxation in selectively grown SiGe fin structures.

    PubMed

    Schulze, A; Loo, R; Ryan, P; Wormington, M; Favia, P; Witters, L; Collaert, N; Bender, H; Vandervorst, W; Caymax, M

    2017-04-07

    The performance of heterogeneous 3D transistor structures critically depends on the composition and strain state of the buffer, channel and source/drain regions. In this paper we used an in-line high resolution x-ray diffraction (HRXRD) tool to study in detail the composition and strain in selectively grown SiGe/Ge fin structures with widths down to 20 nm. For this purpose we arranged fins of identical dimensions into larger arrays which were then analyzed using an x-ray beam several tens of micrometers in size. Asymmetric reciprocal space maps measured both parallel and perpendicular to the fins allowed us to extract the lattice parameters in all three spatial directions. Our results demonstrate an anisotropic in-plane strain state of the selectively grown SiGe buffer in case of narrower fins with significantly reduced relaxation in the direction along the fin. This observation was verified using nano-beam electron diffraction, and is explained based on the reduced probability for dislocation half-loops to evolve in trenches narrower than a few times the critical radius. Moreover, we introduce and discuss in detail a methodology for the determination of the composition in case of an anisotropic in-plane strain state which differs from the procedure commonly used for blanket layers. Our findings verify the importance of in-line HRXRD measurements for process development and monitoring as well as the fundamental study of relaxation and defect formation in confined volumes.

  16. Fin-and-tube heat exchanger material and inlet velocity effect under frosting conditions

    NASA Astrophysics Data System (ADS)

    Keryakos, Elie; Toubassy, Joseph; Danlos, Amélie; Clodic, Denis; Descombes, Georges

    2017-02-01

    The frosting fin-and-tube heat exchanger used in this study is implemented in the dehydration process of a biogas upgrading pilot. Water is separated from the biogas by frosting it at very low temperatures on the cold surfaces of the fin-and-tube heat exchanger. Once frosted, a defrosting system is used to remove water from the process. The main interest of this study is the frosting system. The effects of the biogas velocity, fin material, tube material and frost layer thickness on the performance of the fin-and-tube heat exchanger are investigated. Increasing the biogas velocity tends to increase the frosting layer thickness and the external pressure drop. This will lead to decrease the heat exchanger performance and the frosting cycle duration. The thermal conductivity of the fins and tubes has a major effect on the performance of the heat exchanger. Higher thermal conductivity decreases the heat exchanged surface. A numerical model has been developed, then numerical and experimental results extracted from a biogas upgrading pilot are compared.

  17. Age estimation for shovelnose sturgeon: A cautionary note based on annulus formation in pectoral fin rays

    USGS Publications Warehouse

    Whiteman, K.W.; Travnichek, V.H.; Wildhaber, M.L.; DeLonay, A.; Papoulias, D.; Tillett, D.

    2004-01-01

    Numerous studies have examined the age and growth of shovelnose sturgeon Scaphirhynchus platorynchus, but only one study attempted to validate age estimation techniques. Therefore, our objective was to use marginal increment analysis to validate annulus formation in pectoral fin rays of shovelnose sturgeon collected from the Missouri River. We also compared the precision of age estimates between two different readers. Marginal increment distance indicated that for most of the populations an opaque band was laid down in pectoral fin rays during the summer. However, opaque bands were formed throughout the year in some individuals, which could be problematic when using fin rays for age estimation. The agreement of age estimates by two readers for shovelnose sturgeon was only 18%, and differences in ages between the two readers increased for older fish. The presence of split annuli, false annuli, spawning bands, imbedded rays, and deteriorating sections made individual growth rings difficult to separate. Our findings verified that opaque bands are formed annually during the summer in the pectoral fin rays of most shovelnose sturgeon, but some individuals form opaque bands during other times. Pectoral fin rays will probably continue to be the most practical method of age estimation in shovelnose sturgeon, but ages estimated by this method should be used with caution.

  18. Structure and Output Characteristics of a TEM Array Fitted to a Fin Heat Exchanger

    NASA Astrophysics Data System (ADS)

    Zhang, Z.; Chen, L. N.; Chen, Z. J.; Xiao, G. Q.; Liu, Z. J.

    2015-06-01

    In the design of a thermoelectric generator, both the heat transfer area and the number of thermoelectric modules (TEMs) should be increased accordingly as the generator power increases; crucially, both aspects need to be coordinated. A kilowatt thermoelectric generator with a fin heat exchanger is proposed for use in a constant-speed diesel generator unit. Interior fins enhance convective heat transfer, whereas an exterior fin segment increases the heat transfer area. The heat transfer surface is double that of a plane heat exchanger, and the temperature field over the exterior fins is constrained to a one-dimensional distribution. Between adjoining exterior fins, there is a cooling water channel with trapezoid cross-section, enabling compact TEMs and cooling them. Hence, more TEMs are built as a series-parallel array of TEMs with lower resistance and more stable output current. Under nonuniform conditions, to prevent circulation and energy loss, bypass diodes and antidiodes are added. Experiments and numerical calculations show that, with matching and optimization of the heat exchanger and TEM array, a stable maximum output power is obtainable from the interior of the thermoelectric generator system, which can be connected to an external maximum power point tracking system.

  19. Simulation and characterization of stress in FinFETs using novel LKMC and nanobeam diffraction methods

    NASA Astrophysics Data System (ADS)

    Yiluan, Guo; Guilei, Wang; Chao, Zhao; Jun, Luo

    2015-08-01

    A new simulation method and test instrument has been adopted to verify the traditional stress simulation in FinFET. First, a new algorithm named lattice kinetic Monte Carlo (LKMC) is used to simulate the SiGe epitaxy in source/drain regions and the stress distribution is consequently extracted after the LKMC simulation. Systematic comparison between the traditional polyhedron method and the LKMC method is carried out. The results confirm that extracted stress from both methods is consistent, which verifies the validity of traditional polyhedron method for the purpose of simulating stress in FinFET. In the following experiment, p-type FinFETs with SiGe stressors in source/drain regions are fabricated. The nano beam diffraction (NBD) method is employed to characterize the strain in Si fin. The strain value from the NBD test agrees well with the value extracted from traditional polyhedron simulation. Project supported by the “National S&T Major Project 02”, the Opening Project of Microelectronics Devices & Bulk Si FinFET Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences (No. 2013ZX02303007-001).

  20. A comparison of pectoral fin contact between two different wild dolphin populations

    USGS Publications Warehouse

    Dudzinski, K.M.; Gregg, J.D.; Ribic, C.A.; Kuczaj, S.A.

    2009-01-01

    Contact behaviour involving the pectoral fin has been documented in a number of dolphin species, and various explanations about its function have been offered. Pectoral fin contact can take a variety of forms, and involves a number of body parts and movements, likely differing depending upon social or ecological context. For this study, we compare the pectoral fin contact behaviour of two species of wild dolphins: Indo-Pacific bottlenose dolphins (Tursiops aduncus) from around Mikura Island, Japan, and Atlantic spotted dolphins (Stenella frontalis) from The Bahamas. The two study populations exhibit surprising similarity in the ways in which pectoral fin contacts are used, despite differences in species and environmental conditions at the two sites. Differences in contact rates for calves between the two sites suggest that calf-focused aggression from adult dolphins is more prevalent at Mikura than in The Bahamas. Our results suggest that pectoral fin contact behaviour seems to be driven primarily by social pressures, and may be similar in function to allogrooming described in primates. ?? 2008 Elsevier B.V.

  1. How predation shaped fish: the impact of fin spines on body form evolution across teleosts

    PubMed Central

    Price, S. A.; Friedman, S. T.; Wainwright, P. C.

    2015-01-01

    It is well known that predators can induce morphological changes in some fish: individuals exposed to predation cues increase body depth and the length of spines. We hypothesize that these structures may evolve synergistically, as together, these traits will further enlarge the body dimensions of the fish that gape-limited predators must overcome. We therefore expect that the orientation of the spines will predict which body dimension increases in the presence of predators. Using phylogenetic comparative methods, we tested this prediction on the macroevolutionary scale across 347 teleost families, which display considerable variation in fin spines, body depth and width. Consistent with our predictions, we demonstrate that fin spines on the vertical plane (dorsal and anal fins) are associated with a deeper-bodied optimum. Lineages with spines on the horizontal plane (pectoral fins) are associated with a wider-bodied optimum. Optimal body dimensions across lineages without spines paralleling the body dimension match the allometric expectation. Additionally, lineages with longer spines have deeper and wider body dimensions. This evolutionary relationship between fin spines and body dimensions across teleosts reveals functional synergy between these two traits and a potential macroevolutionary signature of predation on the evolutionary dynamics of body shape. PMID:26559954

  2. Comparison of fin ray sampling methods on white sturgeon Acipenser transmontanus growth and swimming performance.

    PubMed

    Nguyen, P L; Jackson, Z J; Peterson, D L

    2016-02-01

    Effects of two fin-ray sampling methods on swimming performance, growth and survival were evaluated for hatchery-reared sub-adult white sturgeon Acipenser transmontanus. Fish were subjected to either a notch removal treatment in which a small section was removed from an anterior marginal pectoral-fin ray, or a full removal treatment in which an entire marginal pectoral-fin ray was removed. Control fish did not have fin rays removed, but they were subjected to a sham operation. A modified 3230 l Brett-type swim tunnel was used to evaluate 10 min critical station-holding speeds (SCSH ) of A. transmontanus, immediately after the fin ray biopsies were obtained with each method. Survival and growth were evaluated over a 6 month period for a separate group of fish subjected to the same biopsy methods. Mean ± S.E. 10 min SCSH were 108·0 ± 2·3, 110·0 ± 2·6 and 115·0 ± 3·5 cm s(-1) for the notch removal group, full removal group and control group, respectively, and were not significantly different among treatments. Behavioural characteristics including tail-beat frequency and time spent hunkering were also not significantly different among treatment groups swimming at the same speeds. There were no mortalities and relative growth was similar among treatment groups. Average biopsy time for the notch removal method was lower and the wounds appeared to heal more quickly compared with the full removal method.

  3. Effect of Triangular Fins on Critical Heat Flux in Ethanol-cooled Combustion Chamber

    NASA Astrophysics Data System (ADS)

    Takegoshi, Masao; Suzuki, Ryosuke; Saito, Toshihito; Ono, Fumiei; Hiraiwa, Tetsuo; Tomioka, Sadatake

    A pressure-fed engine with a regeneratively-cooled combustion chamber is studied in JAXA. Operation chamber pressure is approximately 1 MPa. A proposed propellant combination is liquid oxygen and ethanol. However, it is necessary to understand the critical heat flux when ethanol is used as a coolant for regeneratively-cooled combustion chamber because the saturation pressure of it is 6.3 MPa. In general, it is known that the cooling wall with fins improves the cooling performance. In this study, the effect of triangular fins on critical heat flux of ethanol in ethanol-cooled combustion chamber was investigated. As the result, it was found that the critical heat flux of cooling wall with triangular fins was 23 % higher than that of that without fin in the same velocity condition of the coolant. The critical heat flux increases by the triangular fins on the cooling surface due to the effect of the combination cooling with film boiling and nucleate boiling.

  4. A flow separation study over a shortfin mako shark pectoral fin

    NASA Astrophysics Data System (ADS)

    Bradshaw, Michael; Lang, Amy; Wahidi, Redha; Smith, Drew; Motta, Philip

    2011-11-01

    Many animals possess performance enhancing mechanisms, such as the denticles found on the skin of the shortfin mako shark (Isurus oxyrinchus). The shortfin mako, one of the fastest sharks on the planet, is covered by small, tooth-like scales that vary in bristling capability. Previous biological findings have shown that the scales increase in flexibility from the leading to trailing edge over the pectoral fin. As this fin is a primary control surface, the scale bristling may provide a mechanism for separation control that leads to decreased drag and increased maneuverability. Such findings can potentially lead to the development of similar micro-scale mechanisms to improve the efficiency of aerospace design. A left pectoral fin (71 cm span) was tested in a water tunnel facility under static and dynamic conditions. Digital Particle Image Velocimetry (DPIV) was used to characterize the flow over the fin. Various angles of attack at two speeds were tested (Re of 44,500 and 68,000). Two chord-wise locations, approximately mid-span where three-dimensional effects were minimized, were viewed to analyze the flow. After the initial testing, the fin was painted to eliminate the effect of the scales and retested to observe flow separation. Supported by REU SITE EEC grant number 1062611.

  5. Observation and understanding of anisotropic strain relaxation in selectively grown SiGe fin structures

    NASA Astrophysics Data System (ADS)

    Schulze, A.; Loo, R.; Ryan, P.; Wormington, M.; Favia, P.; Witters, L.; Collaert, N.; Bender, H.; Vandervorst, W.; Caymax, M.

    2017-04-01

    The performance of heterogeneous 3D transistor structures critically depends on the composition and strain state of the buffer, channel and source/drain regions. In this paper we used an in-line high resolution x-ray diffraction (HRXRD) tool to study in detail the composition and strain in selectively grown SiGe/Ge fin structures with widths down to 20 nm. For this purpose we arranged fins of identical dimensions into larger arrays which were then analyzed using an x-ray beam several tens of micrometers in size. Asymmetric reciprocal space maps measured both parallel and perpendicular to the fins allowed us to extract the lattice parameters in all three spatial directions. Our results demonstrate an anisotropic in-plane strain state of the selectively grown SiGe buffer in case of narrower fins with significantly reduced relaxation in the direction along the fin. This observation was verified using nano-beam electron diffraction, and is explained based on the reduced probability for dislocation half-loops to evolve in trenches narrower than a few times the critical radius. Moreover, we introduce and discuss in detail a methodology for the determination of the composition in case of an anisotropic in-plane strain state which differs from the procedure commonly used for blanket layers. Our findings verify the importance of in-line HRXRD measurements for process development and monitoring as well as the fundamental study of relaxation and defect formation in confined volumes.

  6. A Novel Mini-DNA Barcoding Assay to Identify Processed Fins from Internationally Protected Shark Species

    PubMed Central

    Fields, Andrew T.; Abercrombie, Debra L.; Eng, Rowena; Feldheim, Kevin; Chapman, Demian D.

    2015-01-01

    There is a growing need to identify shark products in trade, in part due to the recent listing of five commercially important species on the Appendices of the Convention on International Trade in Endangered Species (CITES; porbeagle, Lamna nasus, oceanic whitetip, Carcharhinus longimanus scalloped hammerhead, Sphyrna lewini, smooth hammerhead, S. zygaena and great hammerhead S. mokarran) in addition to three species listed in the early part of this century (whale, Rhincodon typus, basking, Cetorhinus maximus, and white, Carcharodon carcharias). Shark fins are traded internationally to supply the Asian dried seafood market, in which they are used to make the luxury dish shark fin soup. Shark fins usually enter international trade with their skin still intact and can be identified using morphological characters or standard DNA-barcoding approaches. Once they reach Asia and are traded in this region the skin is removed and they are treated with chemicals that eliminate many key diagnostic characters and degrade their DNA (“processed fins”). Here, we present a validated mini-barcode assay based on partial sequences of the cytochrome oxidase I gene that can reliably identify the processed fins of seven of the eight CITES listed shark species. We also demonstrate that the assay can even frequently identify the species or genus of origin of shark fin soup (31 out of 50 samples). PMID:25646789

  7. Aluminum-based one- and two-dimensional micro fin array structures: high-throughput fabrication and heat transfer testing

    NASA Astrophysics Data System (ADS)

    Primeaux, Philip A.; Zhang, Bin; Zhang, Xiaoman; Miller, Jacob; Meng, W. J.; KC, Pratik; Moore, Arden L.

    2017-02-01

    Microscale fin array structures were replicated onto surfaces of aluminum 1100 and aluminum 6061 alloy (Al1100/Al6061) sheet metals through room-temperature instrumented roll molding. Aluminum-based micro fin arrays were replicated at room temperature, and the fabrication process is one with high throughput and low cost. One-dimensional (1D) micro fin arrays were made through one-pass rolling, while two-dimensional (2D) micro fin arrays were made by sequential 90° cross rolling with the same roller sleeve. For roll molding of 1D micro fins, fin heights greater than 600 µm were achieved and were shown to be proportional to the normal load force per feature width. At a given normal load force, the fin height was further shown to scale inversely with the hardness of the sheet metal. For sequential 90° cross rolling, morphologies of roll molded 2D micro fin arrays were examined, which provided clues to understand how plastic deformation occurred under cross rolling conditions. A series of pool boiling experiments on low profile Al micro fin array structures were performed within Novec 7100, a widely used commercial dielectric coolant. Results for both horizontal and vertical surface orientations show that roll molded Al micro fin arrays can increase heat flux at fixed surface temperature as compared to un-patterned Al sheet. The present results further suggest that many factors beyond just increased surface area can influence heat transfer performance, including surface finish and the important multiphase transport mechanisms in and around the fin geometry. These factors must also be considered when designing and optimizing micro fin array structures for heat transfer applications.

  8. Flight investigation of effects of a fan-in-fin yaw control concept on helicopter flying-quality characteristics

    NASA Technical Reports Server (NTRS)

    Kelley, H. L.; West, T. C.

    1974-01-01

    Flight-test results which describe flying-quality factors related to the fan-in-fin yaw control concept as utilized on a pre-production version of a European helicopter are presented. Design compromises to be considered with this concept are also presented. The large, fixed vertical fin associated with the fan-in-fin system was helpful in maneuvering flight, but introduced several flying-quality problems when combined with the fan.

  9. Design and Analyze a New Measuring Lift Device for Fin Stabilizers Using Stiffness Matrix of Euler-Bernoulli Beam.

    PubMed

    Liang, Lihua; Sun, Mingxiao; Shi, Hongyu; Luan, Tiantian

    2017-01-01

    Fin-angle feedback control is usually used in conventional fin stabilizers, and its actual anti-rolling effect is difficult to reach theoretical design requirements. Primarily, lift of control torque is a theoretical value calculated by static hydrodynamic characteristics of fin. However, hydrodynamic characteristics of fin are dynamic while fin is moving in waves. As a result, there is a large deviation between actual value and theoretical value of lift. Firstly, the reasons of deviation are analyzed theoretically, which could avoid a variety of interference factors and complex theoretical derivations. Secondly, a new device is designed for direct measurement of actual lift, which is composed of fin-shaft combined mechanism and sensors. This new device can make fin-shaft not only be the basic function of rotating fin, but also detect actual lift. Through analysis using stiffness matrix of Euler-Bernoulli beam, displacement of shaft-core end is measured instead of lift which is difficult to measure. Then quantitative relationship between lift and displacement is defined. Three main factors are analyzed with quantitative relationship. What is more, two installation modes of sensors and a removable shaft-end cover are proposed according to hydrodynamic characteristics of fin. Thus the new device contributes to maintenance and measurement. Lastly, the effectiveness and accuracy of device are verified by contrasting calculation and simulation on the basis of actual design parameters. And the new measuring lift method can be proved to be effective through experiments. The new device is achieved from conventional fin stabilizers. Accordingly, the reliability of original equipment is inherited. The alteration of fin stabilizers is minor, which is suitable for engineering application. In addition, the flexural properties of fin-shaft are digitized with analysis of stiffness matrix. This method provides theoretical support for engineering application by carrying out finite

  10. Experimental investigation for the performance of triangular fin array within a rectangular enclosure in natural convection dominated region

    NASA Astrophysics Data System (ADS)

    Dwivedi, Ankur; Das, Debasish

    2016-12-01

    This study investigates the performance of triangular fin array within a rectangular enclosure with heated bottom wall experimentally at a wide range of Rayleigh number (295214 ≤ Ra ≤ 773410) for different fin height values (12.5 mm ≤ L ≤ 37.5 mm) and fin spacing values (25 mm ≤ S ≤ 100 mm). A new correlation is also proposed for the Nusselt number which is demonstrated the satisfactory capture of the correct qualitative behaviour of system performance.

  11. Design and Analyze a New Measuring Lift Device for Fin Stabilizers Using Stiffness Matrix of Euler-Bernoulli Beam

    PubMed Central

    Liang, Lihua; Sun, Mingxiao; Shi, Hongyu; Luan, Tiantian

    2017-01-01

    Fin-angle feedback control is usually used in conventional fin stabilizers, and its actual anti-rolling effect is difficult to reach theoretical design requirements. Primarily, lift of control torque is a theoretical value calculated by static hydrodynamic characteristics of fin. However, hydrodynamic characteristics of fin are dynamic while fin is moving in waves. As a result, there is a large deviation between actual value and theoretical value of lift. Firstly, the reasons of deviation are analyzed theoretically, which could avoid a variety of interference factors and complex theoretical derivations. Secondly, a new device is designed for direct measurement of actual lift, which is composed of fin-shaft combined mechanism and sensors. This new device can make fin-shaft not only be the basic function of rotating fin, but also detect actual lift. Through analysis using stiffness matrix of Euler-Bernoulli beam, displacement of shaft-core end is measured instead of lift which is difficult to measure. Then quantitative relationship between lift and displacement is defined. Three main factors are analyzed with quantitative relationship. What is more, two installation modes of sensors and a removable shaft-end cover are proposed according to hydrodynamic characteristics of fin. Thus the new device contributes to maintenance and measurement. Lastly, the effectiveness and accuracy of device are verified by contrasting calculation and simulation on the basis of actual design parameters. And the new measuring lift method can be proved to be effective through experiments. The new device is achieved from conventional fin stabilizers. Accordingly, the reliability of original equipment is inherited. The alteration of fin stabilizers is minor, which is suitable for engineering application. In addition, the flexural properties of fin-shaft are digitized with analysis of stiffness matrix. This method provides theoretical support for engineering application by carrying out finite

  12. Structural and electronic properties of Si(n), Si(n)-, and PSi(n-1) clusters (2 < or = n < or = 13): Theoretical investigation based on ab initio molecular orbital theory.

    PubMed

    Nigam, Sandeep; Majumder, Chiranjib; Kulshreshtha, S K

    2006-08-21

    The geometric and electronic structures of Si(n), Si(n)-, and PSi(n-1) clusters (2 < or = n < or = 13) have been investigated using the ab initio molecular orbital theory formalism. The hybrid exchange-correlation energy functional (B3LYP) and a standard split-valence basis set with polarization functions (6-31+G(d)) were employed to optimize geometrical configurations. The total energies of the lowest energy isomers thus obtained were recalculated at the MP2/aug-cc-pVTZ level of theory. Unlike positively charged clusters, which showed similar structural behavior as that of neutral clusters [Nigam et al., J. Chem. Phys. 121, 7756 (2004)], significant geometrical changes were observed between Si(n) and Si(n)- clusters for n = 6, 8, 11, and 13. However, the geometries of P substituted silicon clusters show similar growth as that of negatively charged Si(n) clusters with small local distortions. The relative stability as a function of cluster size has been verified based on their binding energies, second difference in energy (Delta2 E), and fragmentation behavior. In general, the average binding energy of Si(n)- clusters is found to be higher than that of Si(n) clusters. For isoelectronic PSi(n-1) clusters, it is found that although for small clusters (n < 4) substitution of P atom improves the binding energy of Si(n) clusters, for larger clusters (n > or = 4) the effect is opposite. The fragmentation behavior of these clusters reveals that while small clusters prefer to evaporate monomer, the larger ones dissociate into two stable clusters of smaller size. The adiabatic electron affinities of Si(n) clusters and vertical detachment energies of Si(n)- clusters were calculated and compared with available experimental results. Finally, a good agreement between experimental and our theoretical results suggests good prediction of the lowest energy isomeric structures for all clusters calculated in the present study.

  13. Bicarbonate Plays a Critical Role in the Generation of Cytotoxicity during SIN-1 Decomposition in Culture Medium

    PubMed Central

    Shirai, Kyo; Okada, Tatsumi; Konishi, Kanako; Murata, Hiroshi; Akashi, Soichiro; Sugawara, Fumio; Watanabe, Nobuo; Arai, Takao

    2012-01-01

    3-Morpholinosydnonimine (SIN-1) is used as a donor of peroxynitrite (ONOO−) in various studies. We demonstrated, however, that, the cell-culture medium remains cytotoxic to PC12 cells even after almost complete SIN-1 decomposition, suggesting that reaction product(s) in the medium, rather than ONOO−, exert cytotoxic effects. Here, we clarified that significant cytotoxicity persists after SIN-1 decomposes in bicarbonate, a component of the culture medium, but not in NaOH. Cytotoxic SIN-1-decomposed bicarbonate, which lacks both oxidizing and nitrosating activities, degrades to innocuous state over time. The extent of SIN-1 cytotoxicity, irrespective of its fresh or decomposed state, appears to depend on the total number of initial SIN-1 molecules per cell, rather than its concentration, and involves oxidative/nitrosative stress-related cell damage. These results suggest that, despite its low abundance, the bicarbonate-dependent cytotoxic substance that accumulates in the medium during SIN-1 breakdown is the cytotoxic entity of SIN-1. PMID:22848780

  14. Constructing a Counternarrative: Students Informing Now (S.I.N.) Reframes Immigration and Education in the United States

    ERIC Educational Resources Information Center

    Dominguez, Neidi; Duarte, Yazmin; Espinosa, Pedro Joel; Martinez, Luis; Nygreen, Kysa; Perez, Renato; Ramirez, Izel; Saba, Mariella

    2009-01-01

    The work of Students Informing Now (S.I.N.), an immigrant student organization at the University of California, Santa Cruz, is described in this column. The authors argue that S.I.N.'s diverse activities and textual products construct a counternarrative that challenges and reframes the debate on undocumented students and immigration. Focusing on…

  15. Rapid Transfer Alignment of MEMS SINS Based on Adaptive Incremental Kalman Filter

    PubMed Central

    Chu, Hairong; Sun, Tingting; Zhang, Baiqiang; Zhang, Hongwei; Chen, Yang

    2017-01-01

    In airborne MEMS SINS transfer alignment, the error of MEMS IMU is highly environment-dependent and the parameters of the system model are also uncertain, which may lead to large error and bad convergence of the Kalman filter. In order to solve this problem, an improved adaptive incremental Kalman filter (AIKF) algorithm is proposed. First, the model of SINS transfer alignment is defined based on the “Velocity and Attitude” matching method. Then the detailed algorithm progress of AIKF and its recurrence formulas are presented. The performance and calculation amount of AKF and AIKF are also compared. Finally, a simulation test is designed to verify the accuracy and the rapidity of the AIKF algorithm by comparing it with KF and AKF. The results show that the AIKF algorithm has better estimation accuracy and shorter convergence time, especially for the bias of the gyroscope and the accelerometer, which can meet the accuracy and rapidity requirement of transfer alignment. PMID:28098829

  16. AUV Underwater Positioning Algorithm Based on Interactive Assistance of SINS and LBL

    PubMed Central

    Zhang, Tao; Chen, Liping; Li, Yao

    2015-01-01

    This paper studies an underwater positioning algorithm based on the interactive assistance of a strapdown inertial navigation system (SINS) and LBL, and this algorithm mainly includes an optimal correlation algorithm with aided tracking of an SINS/Doppler velocity log (DVL)/magnetic compass pilot (MCP), a three-dimensional TDOA positioning algorithm of Taylor series expansion and a multi-sensor information fusion algorithm. The final simulation results show that compared to traditional underwater positioning algorithms, this scheme can not only directly correct accumulative errors caused by a dead reckoning algorithm, but also solves the problem of ambiguous correlation peaks caused by multipath transmission of underwater acoustic signals. The proposed method can calibrate the accumulative error of the AUV position more directly and effectively, which prolongs the underwater operating duration of the AUV. PMID:26729120

  17. Rapid Transfer Alignment of MEMS SINS Based on Adaptive Incremental Kalman Filter.

    PubMed

    Chu, Hairong; Sun, Tingting; Zhang, Baiqiang; Zhang, Hongwei; Chen, Yang

    2017-01-14

    In airborne MEMS SINS transfer alignment, the error of MEMS IMU is highly environment-dependent and the parameters of the system model are also uncertain, which may lead to large error and bad convergence of the Kalman filter. In order to solve this problem, an improved adaptive incremental Kalman filter (AIKF) algorithm is proposed. First, the model of SINS transfer alignment is defined based on the "Velocity and Attitude" matching method. Then the detailed algorithm progress of AIKF and its recurrence formulas are presented. The performance and calculation amount of AKF and AIKF are also compared. Finally, a simulation test is designed to verify the accuracy and the rapidity of the AIKF algorithm by comparing it with KF and AKF. The results show that the AIKF algorithm has better estimation accuracy and shorter convergence time, especially for the bias of the gyroscope and the accelerometer, which can meet the accuracy and rapidity requirement of transfer alignment.

  18. An Improved Inertial Frame Alignment Algorithm Based on Horizontal Alignment Information for Marine SINS.

    PubMed

    Che, Yanting; Wang, Qiuying; Gao, Wei; Yu, Fei

    2015-10-05

    In this paper, an improved inertial frame alignment algorithm for a marine SINS under mooring conditions is proposed, which significantly improves accuracy. Since the horizontal alignment is easy to complete, and a characteristic of gravity is that its component in the horizontal plane is zero, we use a clever method to improve the conventional inertial alignment algorithm. Firstly, a large misalignment angle model and a dimensionality reduction Gauss-Hermite filter are employed to establish the fine horizontal reference frame. Based on this, the projection of the gravity in the body inertial coordinate frame can be calculated easily. Then, the initial alignment algorithm is accomplished through an inertial frame alignment algorithm. The simulation and experiment results show that the improved initial alignment algorithm performs better than the conventional inertial alignment algorithm, and meets the accuracy requirements of a medium-accuracy marine SINS.

  19. AUV Underwater Positioning Algorithm Based on Interactive Assistance of SINS and LBL.

    PubMed

    Zhang, Tao; Chen, Liping; Li, Yao

    2015-12-30

    This paper studies an underwater positioning algorithm based on the interactive assistance of a strapdown inertial navigation system (SINS) and LBL, and this algorithm mainly includes an optimal correlation algorithm with aided tracking of an SINS/Doppler velocity log (DVL)/magnetic compass pilot (MCP), a three-dimensional TDOA positioning algorithm of Taylor series expansion and a multi-sensor information fusion algorithm. The final simulation results show that compared to traditional underwater positioning algorithms, this scheme can not only directly correct accumulative errors caused by a dead reckoning algorithm, but also solves the problem of ambiguous correlation peaks caused by multipath transmission of underwater acoustic signals. The proposed method can calibrate the accumulative error of the AUV position more directly and effectively, which prolongs the underwater operating duration of the AUV.

  20. Deacetylase inhibitors dissociate the histone-targeting ING2 subunit from the Sin3 complex

    PubMed Central

    Smith, Karen T.; Martin-Brown, Skylar A.; Florens, Laurence; Washburn, Michael P.; Workman, Jerry L.

    2010-01-01

    Summary Histone deacetylase (HDAC) inhibitors are in clinical development for several diseases, including cancers and neurodegenerative disorders. HDACs1 and 2 are among the targets of these inhibitors and are part of multisubunit protein complexes. HDAC inhibitors (HDACi) block the activity of HDACs by chelating a zinc molecule in their catalytic sites. It is not known if the inhibitors have any additional functional effects on the multisubunit HDAC complexes. Here, we find that suberoylanilide hydroxamic acid (SAHA), the recently FDA approved HDACi, causes the dissociation of the PHD-finger containing ING2 subunit from the Sin3 deacetylase complex. Loss of ING2 disrupts the in vivo binding of the Sin3 complex to the p21 promoter, an important target gene for cell growth inhibition by SAHA. Our findings reveal a new molecular mechanism by which HDAC inhibitors disrupt deacetylase function. PMID:20142042

  1. Subcooled freon-11 flow boiling in top-heated finned coolant channels with and without a twisted tape

    NASA Technical Reports Server (NTRS)

    Smith, Alvin; Boyd, Ronald D., Sr.

    1989-01-01

    An experimental study was conducted in top-heated finned horizontal tubes to study the effect of enhancement devices on flow boiling heat transfer in coolant channels. The objectives are to examine the variations in both the mean and local (axial and circumferential) heat transfer coefficients for circular coolant channels with spiral finned walls and/or spiral fins with a twisted tape, and improve the data reduction technique of a previous investigator. The working fluid is freon-11 with an inlet temperature of 22.2 C (approximately 21 C subcooling). The coolant channel's exit pressure and mass velocity are 0.19 M Pa (absolute) and 0.21 Mg/sq. ms, respectively. Two tube configurations were examined; i.e., tubes had either 6.52 (small pitch) or 4.0 (large pitch) fins/cm of the circumferential length (26 and 16 fins, respectively). The large pitch fins were also examined with a twisted tape insert. The inside nominal diameter of the copper channels at the root of the fins was 1.0 cm. The results show that by adding enhancement devices, boiling occurs almost simultaneously at all axial locations. The case of spiral fins with large pitch resulted in larger mean (circumferentially averaged) heat transfer coefficients, h sub m, at all axial locations. Finally, when twisted tape is added to the tube with large-pitched fins, the power required for the onset of boiling is reduced at all axial and circumferential locations.

  2. Subcooled freon-11 flow boiling in top-heated finned coolant channels with and without a twisted tape

    NASA Astrophysics Data System (ADS)

    Smith, Alvin; Boyd, Ronald D., Sr.

    An experimental study was conducted in top-heated finned horizontal tubes to study the effect of enhancement devices on flow boiling heat transfer in coolant channels. The objectives are to examine the variations in both the mean and local (axial and circumferential) heat transfer coefficients for circular coolant channels with spiral finned walls and/or spiral fins with a twisted tape, and improve the data reduction technique of a previous investigator. The working fluid is freon-11 with an inlet temperature of 22.2 C (approximately 21 C subcooling). The coolant channel's exit pressure and mass velocity are 0.19 M Pa (absolute) and 0.21 Mg/sq. ms, respectively. Two tube configurations were examined; i.e., tubes had either 6.52 (small pitch) or 4.0 (large pitch) fins/cm of the circumferential length (26 and 16 fins, respectively). The large pitch fins were also examined with a twisted tape insert. The inside nominal diameter of the copper channels at the root of the fins was 1.0 cm. The results show that by adding enhancement devices, boiling occurs almost simultaneously at all axial locations. The case of spiral fins with large pitch resulted in larger mean (circumferentially averaged) heat transfer coefficients, h sub m, at all axial locations. Finally, when twisted tape is added to the tube with large-pitched fins, the power required for the onset of boiling is reduced at all axial and circumferential locations.

  3. Allometric growth of the trunk leads to the rostral shift of the pelvic fin in teleost fishes.

    PubMed

    Murata, Yumie; Tamura, Mika; Aita, Yusuke; Fujimura, Koji; Murakami, Yasunori; Okabe, Masataka; Okada, Norihiro; Tanaka, Mikiko

    2010-11-01

    The pelvic fin position among teleost fishes has shifted rostrally during evolution, resulting in diversification of both behavior and habitat. We explored the developmental basis for the rostral shift in pelvic fin position in teleost fishes using zebrafish (abdominal pelvic fins) and Nile tilapia (thoracic pelvic fins). Cell fate mapping experiments revealed that changes in the distribution of lateral plate mesodermal cells accompany the trunk-tail protrusion. Presumptive pelvic fin cells are originally located at the body wall adjacent to the anterior limit of hoxc10a expression in the spinal cord, and their position shifts rostrally as the trunk grows. We then showed that the differences in pelvic fin position between zebrafish and Nile tilapia were not due to changes in expression or function of gdf11. We also found that hox-independent motoneurons located above the pelvic fins innervate into the pelvic musculature. Our results suggest that there is a common mechanism among teleosts and tetrapods that controls paired appendage positioning via gdf11, but in teleost fishes the position of prospective pelvic fin cells on the yolk surface shifts as the trunk grows. In addition, teleost motoneurons, which lack lateral motor columns, innervate the pelvic fins in a manner independent of the rostral-caudal patterns of hox expression in the spinal cord.

  4. Climatic controls on debris-flow activity and sediment aggradation: The Del Medio fan, NW Argentina

    NASA Astrophysics Data System (ADS)

    Savi, Sara; Schildgen, Taylor F.; Tofelde, Stefanie; Wittmann, Hella; Scherler, Dirk; Mey, Jürgen; Alonso, Ricardo N.; Strecker, Manfred R.

    2016-12-01

    In the Central Andes, several studies on alluvial terraces and valley fills have linked sediment aggradation to periods of enhanced sediment supply. However, debate continues over whether tectonic or climatic factors are most important in triggering the enhanced supply. The Del Medio catchment in the Humahuaca Basin (Eastern Cordillera, NW Argentina) is located within a transition zone between subhumid and arid climates and hosts the only active debris-flow fan within this intermontane valley. By combining 10Be analyses of boulder and sediment samples within the Del Medio catchment, with regional morphometric measurements of nearby catchments, we identify the surface processes responsible for aggradation in the Del Medio fan and their likely triggers. We find that the fan surface has been shaped by debris flows and channel avulsions during the last 400 years. Among potential tectonic, climatic, and autogenic factors that might influence deposition, our analyses point to a combination of several favorable factors that drive aggradation. These are in particular the impact of occasional abundant rainfall on steep slopes in rock types prone to failure, located in a region characterized by relatively low rainfall amounts and limited transport capacity. These characteristics are primarily associated with the climatic transition zone between the humid foreland and the arid orogen interior, which creates an imbalance between sediment supply and sediment transfer. The conditions and processes that drive aggradation in the Del Medio catchment today may provide a modern analog for the conditions and processes that drove aggradation in other nearby tributaries in the past.

  5. Molecular signaling networks that choreograph epimorphic fin regeneration in zebrafish - a mini-review.

    PubMed

    Tal, Tamara L; Franzosa, Jill A; Tanguay, Robert L

    2010-01-01

    This short review provides a current synopsis of caudal fin regeneration in zebrafish with an emphasis on the molecular signaling networks that dictate epimorphic regeneration. At the outset, the fundamentals of caudal fin architecture and the stages of epimorphic regeneration are described. This is followed by a detailed look at the main networks implicated in fin regeneration, namely the Wnt, fibroblast growth factor, activin-betaA, retinoic acid and hedgehog signaling pathways. Throughout this mini-review, these molecular networks are examined through the lens of wound healing, blastema formation or regenerative outgrowth, three of the main stages of epimorphic regeneration. Next, the emerging role of noncoding RNAs as regulators of regeneration and mechanisms of regenerative termination are discussed. Finally, the implications for future research and the broader field of regenerative medicine are examined.

  6. Tetrapod limb and sarcopterygian fin regeneration share a core genetic programme

    PubMed Central

    Nogueira, Acacio F.; Costa, Carinne M.; Lorena, Jamily; Moreira, Rodrigo N.; Frota-Lima, Gabriela N.; Furtado, Carolina; Robinson, Mark; Amemiya, Chris T.; Darnet, Sylvain; Schneider, Igor

    2016-01-01

    Salamanders are the only living tetrapods capable of fully regenerating limbs. The discovery of salamander lineage-specific genes (LSGs) expressed during limb regeneration suggests that this capacity is a salamander novelty. Conversely, recent paleontological evidence supports a deeper evolutionary origin, before the occurrence of salamanders in the fossil record. Here we show that lungfishes, the sister group of tetrapods, regenerate their fins through morphological steps equivalent to those seen in salamanders. Lungfish de novo transcriptome assembly and differential gene expression analysis reveal notable parallels between lungfish and salamander appendage regeneration, including strong downregulation of muscle proteins and upregulation of oncogenes, developmental genes and lungfish LSGs. MARCKS-like protein (MLP), recently discovered as a regeneration-initiating molecule in salamander, is likewise upregulated during early stages of lungfish fin regeneration. Taken together, our results lend strong support for the hypothesis that tetrapods inherited a bona fide limb regeneration programme concomitant with the fin-to-limb transition. PMID:27804976

  7. Non-Fourier Thermoelastic Analysis of an Annular Fin with Variable Convection Heat Transfer Coefficient

    NASA Astrophysics Data System (ADS)

    Lee, Haw-Long; Chang, Win-Jin; Chen, Wen-Lih; Yang, Yu-Ching

    2012-06-01

    This paper numerically investigates the hyperbolic thermoelastic problem of an annular fin. The ambient convection heat transfer coefficient of the fin is assumed to be spatially varying. The major difficulty in dealing with such problems is the suppression of numerical oscillations in the vicinity of a jump discontinuity. An efficient numerical scheme involving hybrid application of Laplace transform and control volume method in conjunction with hyperbolic shape functions is used to solve the linear hyperbolic heat conduction equation. The transformed nodal temperatures are inverted to the physical quantities by using numerical inversion of the Laplace transform. Then the stress distributions in the annular fin are calculated subsequently. The results in the illustrated examples show that the application of hyperbolic shape functions can successfully suppress the numerical oscillations in the vicinity of jump discontinuities.

  8. Control Law Synthesis for Vertical Fin Buffeting Alleviation Using Strain Actuation

    NASA Technical Reports Server (NTRS)

    Nitzsche, F.; Zimcik, D. G.; Ryall, T. G.; Moses, R. W.; Henderson, D. A.

    1999-01-01

    In the present investigation, the results obtained during the ground test of a closed-loop control system conducted on a full-scale fighter to attenuate vertical fin buffeting response using strain actuation are presented. Two groups of actuators consisting of piezoelectric elements distributed over the structure were designed to achieve authority over the first and second modes of the vertical fin. The control laws were synthesized using the Linear Quadratic Gaussian (LQG) method for a time-invariant control system. Three different pairs of sensors including strain gauges and accelerometers at different locations were used to close the feedback loop. The results demonstrated that measurable reductions in the root-mean-square (RMS) values of the fin dynamic response identified by the strain transducer at the critical point for fatigue at the root were achieved under the most severe buffet condition. For less severe buffet conditions, reductions of up to 58% were achieved.

  9. Thrust production and wake structure of a batoid-inspired oscillating fin.

    PubMed

    Clark, R P; Smits, A J

    2006-01-01

    Experiments are reported on the hydrodynamic performance of a flexible fin. The fin replicates some features of the pectoral fin of a batoid fish (such as a ray or skate) in that it is actuated in a travelling wave motion, with the amplitude of the motion increasing linearly along the span from root to tip. Thrust is found to increase with non-dimensional frequency, and an optimal oscillatory gait is identified. Power consumption measurements lead to the computation of propulsive efficiency, and an optimal efficiency condition is evaluated. Wake visualizations are presented, and a vortex model of the wake near zero net thrust is suggested. Strouhal number effects on the wake topology are also illustrated.

  10. Thermal analysis of a finned-tube LHTS module for a solar dynamic power system

    NASA Astrophysics Data System (ADS)

    Seeniraj, R. V.; Velraj, R.; Lakshmi Narasimhan, N.

    This paper investigates the transient behaviour of a finned tube latent heat thermal storage (LHTS) module that is put into use in space based power systems, or such similar energy storage applications. The shell side of the module is loaded with phase change material (PCM) while the tubes carry the heat transfer fluid (HTF). Thin circumferential fins are added externally onto the tube surface at equal spacings. The LHTS module is mathematically modeled with an enthalpy based method and the resulting system of conjugate governing equations is numerically solved for charging mode. The influence of various parameters viz. geometrical, thermophysical and various non-dimensional numbers on the performance of the unit is studied. Numerical results indicate an appreciable enhancement in the energy storage process with the addition of fins in the module for an effective utilisation of the available solar energy during the active phase of the orbit orcharging cycle.

  11. Performance enhancement of AlGaN/GaN nanochannel omega-FinFET

    NASA Astrophysics Data System (ADS)

    Im, Ki-Sik; Seo, Jae Hwa; Vodapally, Sindhuri; Kang, In Man; Lee, Jae-Hoon; Cristoloveanu, Sorin; Lee, Jung-Hee

    2017-03-01

    Novel AlGaN/GaN omega-shaped nanochannel FinFETs with fin width of 50 nm were successfully fabricated using TMAH lateral wet etching with ALD HfO2 sidewall spacer. This fin structure apparently exhibited the current spreading in the access region, which results in the suppression of the drain lag effect at high drain voltage and sharp switching performance with subthreshold swing of 57-65 mV/decade. Excellent on- and off-state state performances for the fabricated device prove that the omega-shaped gate structure not only exhibits excellent gate controllability, but also decouples the active nano-channel region from the underlying thick buffer. The proposed device is very promising candidate for high-performance device applications.

  12. Stabilization of ion concentration polarization layer using micro fin structure for high-throughput applications.

    PubMed

    Kim, Kihong; Kim, Wonseok; Lee, Hyekyung; Kim, Sung Jae

    2017-03-09

    Ion concentration polarization (ICP) has been extensively researched concerning new fundamentals in nanoscale electrokinetics and novel engineering applications. While biomedical and environmental ICP applications have a number of advantages compared to conventional methods, the technique has suffered from the critical limitation of low processing capacity because it has been usually presented in a micro/nanofluidic platform. In this paper, we devised micro fin structures inside a macroscale high-throughput ICP device and successfully demonstrated a stable formation of ICP layer and its performance. Since the fin structures created surface conductive fluidic circumstances and assisted in physically suppressing undesirable electrokinetic vortices generated in this fluidic regime, ICP was stably generated even in this macroscale system. Finally, batch-type droplet ICP preconcentrator and continuous-type ICP separator were introduced as examples for high-throughput millimeter-scale ICP devices using the implanted fin structures.

  13. Nanofluid jet impingement heat transfer characteristics in the rectangular mini-fin heat sink

    NASA Astrophysics Data System (ADS)

    Naphon, Paisarn; Nakharintr, Lursukd

    2012-11-01

    The nanofluid jet impingement heat transfer characteristics in a rectangular mini-fin heat sink are studied. The heat sink is fabricated from aluminum by a wire electrical discharge machine. The nanofluid is a mixture of deionized water and nanoscale TiO2 particles with a volume nanoparticle concentration of 0.2%. The results obtained for nanofluid jet impingement cooling in the rectangular mini-fin heat sink are compared with those found in the water jet impingement cooling. The effects of the inlet temperature of the nanofluid, its Reynolds number, and the heat flux on the heat transfer characteristics of the rectangular mini-fin heat sink are considered. It is found that the average heat transfer rates for the nanofluid as coolant are higher than those for deionized water.

  14. A Novel Scheme for DVL-Aided SINS In-Motion Alignment Using UKF Techniques

    PubMed Central

    Li, Wanli; Wang, Jinling; Lu, Liangqing; Wu, Wenqi

    2013-01-01

    In-motion alignment of Strapdown Inertial Navigation Systems (SINS) without any geodetic-frame observations is one of the toughest challenges for Autonomous Underwater Vehicles (AUV). This paper presents a novel scheme for Doppler Velocity Log (DVL) aided SINS alignment using Unscented Kalman Filter (UKF) which allows large initial misalignments. With the proposed mechanism, a nonlinear SINS error model is presented and the measurement model is derived under the assumption that large misalignments may exist. Since a priori knowledge of the measurement noise covariance is of great importance to robustness of the UKF, the covariance-matching methods widely used in the Adaptive KF (AKF) are extended for use in Adaptive UKF (AUKF). Experimental results show that the proposed DVL-aided alignment model is effective with any initial heading errors. The performances of the adaptive filtering methods are evaluated with regards to their parameter estimation stability. Furthermore, it is clearly shown that the measurement noise covariance can be estimated reliably by the adaptive UKF methods and hence improve the performance of the alignment. PMID:23322105

  15. Methylglyoxal modification of mSin3A links glycolysis to angiopoietin-2 transcription.

    PubMed

    Yao, Dachun; Taguchi, Tetsuya; Matsumura, Takeshi; Pestell, Richard; Edelstein, Diane; Giardino, Ida; Suske, Guntram; Ahmed, Naila; Thornalley, Paul J; Sarthy, Vijay P; Hammes, Hans-Peter; Brownlee, Michael

    2006-01-27

    Methylglyoxal is a highly reactive dicarbonyl degradation product formed from triose phosphates during glycolysis. Methylglyoxal forms stable adducts primarily with arginine residues of intracellular proteins. The biologic role of this covalent modification in regulating cell function is not known. Here, we report that in retinal Müller cells, increased glycolytic flux causes increased methylglyoxal modification of the corepressor mSin3A. Methylglyoxal modification of mSin3A results in increased recruitment of O-GlcNAc transferase to an mSin3A-Sp3 complex, with consequent increased modification of Sp3 by O-linked N-acetylglucosamine. This modification of Sp3 causes decreased binding of the repressor complex to a glucose-responsive GC box in the angiopoietin-2 promoter, resulting in increased Ang-2 expression. A similar mechanism involving methylglyoxal-modification of other coregulator proteins may play a role in the pathobiology of a variety of conditions associated with changes in methylglyoxal concentration, including cancer and diabetic vascular disease.

  16. Initial Alignment of Large Azimuth Misalignment Angles in SINS Based on Adaptive UPF

    PubMed Central

    Sun, Jin; Xu, Xiao-Su; Liu, Yi-Ting; Zhang, Tao; Li, Yao

    2015-01-01

    The case of large azimuth misalignment angles in a strapdown inertial navigation system (SINS) is analyzed, and a method of using the adaptive UPF for the initial alignment is proposed. The filter is based on the idea of a strong tracking filter; through the introduction of the attenuation memory factor to effectively enhance the corrections of the current information residual error on the system, it reduces the influence on the system due to the system simplification, and the uncertainty of noise statistical properties to a certain extent; meanwhile, the UPF particle degradation phenomenon is better overcome. Finally, two kinds of non-linear filters, UPF and adaptive UPF, are adopted in the initial alignment of large azimuth misalignment angles in SINS, and the filtering effects of the two kinds of nonlinear filter on the initial alignment were compared by simulation and turntable experiments. The simulation and turntable experiment results show that the speed and precision of the initial alignment using adaptive UPF for a large azimuth misalignment angle in SINS under the circumstance that the statistical properties of the system noise are certain or not have been improved to some extent. PMID:26334277

  17. Initial Alignment of Large Azimuth Misalignment Angles in SINS Based on Adaptive UPF.

    PubMed

    Sun, Jin; Xu, Xiao-Su; Liu, Yi-Ting; Zhang, Tao; Li, Yao

    2015-08-31

    The case of large azimuth misalignment angles in a strapdown inertial navigation system (SINS) is analyzed, and a method of using the adaptive UPF for the initial alignment is proposed. The filter is based on the idea of a strong tracking filter; through the introduction of the attenuation memory factor to effectively enhance the corrections of the current information residual error on the system, it reduces the influence on the system due to the system simplification, and the uncertainty of noise statistical properties to a certain extent; meanwhile, the UPF particle degradation phenomenon is better overcome. Finally, two kinds of non-linear filters, UPF and adaptive UPF, are adopted in the initial alignment of large azimuth misalignment angles in SINS, and the filtering effects of the two kinds of nonlinear filter on the initial alignment were compared by simulation and turntable experiments. The simulation and turntable experiment results show that the speed and precision of the initial alignment using adaptive UPF for a large azimuth misalignment angle in SINS under the circumstance that the statistical properties of the system noise are certain or not have been improved to some extent.

  18. Regulatory mutations in Sin recombinase support a structure-based model of the synaptosome

    PubMed Central

    Rowland, Sally-J; Boocock, Martin R; McPherson, Arlene L; Mouw, Kent W; Rice, Phoebe A; Stark, W Marshall

    2009-01-01

    The resolvase Sin regulates DNA strand exchange by assembling an elaborate interwound synaptosome containing catalytic and regulatory Sin tetramers, and an architectural DNA-bending protein. The crystal structure of the regulatory tetramer was recently solved, providing new insights into the structural basis for regulation. Here we describe the selection and characterization of two classes of Sin mutations that, respectively, bypass or disrupt the functions of the regulatory tetramer. Activating mutations, which allow the catalytic tetramer to assemble and function independently at site I (the crossover site), were found at ∼20% of residues in the N-terminal domain. The most strongly activating mutation (Q115R) stabilized a catalytically active synaptic tetramer in vitro. The positions of these mutations suggest that they act by destabilizing the conformation of the ground-state site I-bound dimers, or by stabilizing the altered conformation of the active catalytic tetramer. Mutations that block activation by the regulatory tetramer mapped to just two residues, F52 and R54, supporting a functional role for a previously reported crystallographic dimer–dimer interface. We suggest how F52/R54 contacts between regulatory and catalytic subunits might promote assembly of the active catalytic tetramer within the synaptosome. PMID:19508283

  19. Resolution of ray-finned fish phylogeny and timing of diversification

    PubMed Central

    Near, Thomas J.; Eytan, Ron I.; Dornburg, Alex; Kuhn, Kristen L.; Moore, Jon A.; Davis, Matthew P.; Wainwright, Peter C.; Friedman, Matt; Smith, W. Leo

    2012-01-01

    Ray-finned fishes make up half of all living vertebrate species. Nearly all ray-finned fishes are teleosts, which include most commercially important fish species, several model organisms for genomics and developmental biology, and the dominant component of marine and freshwater vertebrate faunas. Despite the economic and scientific importance of ray-finned fishes, the lack of a single comprehensive phylogeny with corresponding divergence-time estimates has limited our understanding of the evolution and diversification of this radiation. Our analyses, which use multiple nuclear gene sequences in conjunction with 36 fossil age constraints, result in a well-supported phylogeny of all major ray-finned fish lineages and molecular age estimates that are generally consistent with the fossil record. This phylogeny informs three long-standing problems: specifically identifying elopomorphs (eels and tarpons) as the sister lineage of all other teleosts, providing a unique hypothesis on the radiation of early euteleosts, and offering a promising strategy for resolution of the “bush at the top of the tree” that includes percomorphs and other spiny-finned teleosts. Contrasting our divergence time estimates with studies using a single nuclear gene or whole mitochondrial genomes, we find that the former underestimates ages of the oldest ray-finned fish divergences, but the latter dramatically overestimates ages for derived teleost lineages. Our time-calibrated phylogeny reveals that much of the diversification leading to extant groups of teleosts occurred between the late Mesozoic and early Cenozoic, identifying this period as the “Second Age of Fishes.” PMID:22869754

  20. Body wall development in lamprey and a new perspective on the origin of vertebrate paired fins.

    PubMed

    Tulenko, Frank J; McCauley, David W; Mackenzie, Ethan L; Mazan, Sylvie; Kuratani, Shigeru; Sugahara, Fumiaki; Kusakabe, Rie; Burke, Ann C

    2013-07-16

    Classical hypotheses regarding the evolutionary origin of paired appendages propose transformation of precursor structures (gill arches and lateral fin folds) into paired fins. During development, gnathostome paired appendages form as outgrowths of body wall somatopleure, a tissue composed of somatic lateral plate mesoderm (LPM) and overlying ectoderm. In amniotes, LPM contributes connective tissue to abaxial musculature and forms ventrolateral dermis of the interlimb body wall. The phylogenetic distribution of this character is uncertain because lineage analyses of LPM have not been generated in anamniotes. We focus on the evolutionary history of the somatopleure to gain insight into the tissue context in which paired fins first appeared. Lampreys diverged from other vertebrates before the acquisition of paired fins and provide a model for investigating the preappendicular condition. We present vital dye fate maps that suggest the somatopleure is eliminated in lamprey as the LPM is separated from the ectoderm and sequestered to the coelomic linings during myotome extension. We also examine the distribution of postcranial mesoderm in catshark and axolotl. In contrast to lamprey, our findings support an LPM contribution to the trunk body wall of these taxa, which is similar to published data for amniotes. Collectively, these data lead us to hypothesize that a persistent somatopleure in the lateral body wall is a gnathostome synapomorphy, and the redistribution of LPM was a key step in generating the novel developmental module that ultimately produced paired fins. These embryological criteria can refocus arguments on paired fin origins and generate hypotheses testable by comparative studies on the source, sequence, and extent of genetic redeployment.

  1. Machine-Thermal Coupling Stresses Analysis of the Fin-Type Structural Thermoelectric Generator

    NASA Astrophysics Data System (ADS)

    Zhang, Zheng; Yue, Hao; Chen, Dongbo; Qin, Delei; Chen, Zijian

    2017-02-01

    The design structure and heat-transfer mechanism of a thermoelectric generator (TEG) determine its body temperature state. Thermal stress and thermal deformation generated by the temperature variation directly affect the stress state of thermoelectric modules (TEMs). Therefore, the rated temperature and pressing force of TEMs are important parameters in TEG design. Here, the relationships between structural of a fin-type TEG (FTEG) and these parameters are studied by modeling and "machine-thermal" coupling simulation. An indirect calculation method is adopted in the coupling simulation. First, numerical heat transfer calculations of a three-dimensional FTEG model are conducted according to an orthogonal simulation table. The influences of structural parameters for heat transfer in the channel and outer fin temperature distribution are analyzed. The optimal structural parameters are obtained and used to simulate temperature field of the outer fins. Second, taking the thermal calculation results as the initial condition, the thermal-solid coupling calculation is adopted. The thermal stresses of outer fin, mechanical force of spring-angle pressing mechanism, and clamping force on a TEM are analyzed. The simulation results show that the heat transfer area of the inner fin and the physical parameters of the metal materials are the keys to determining the FTEG temperature field. The pressing mechanism's mechanical force can be reduced by reducing the outer fin angle. In addition, a corrugated cooling water pipe, which has cooling and spring functionality, is conducive to establishing an adaptable clamping force to avoid the TEMs being crushed by the thermal stresses in the body.

  2. Loss of fish actinotrichia proteins and the fin-to-limb transition.

    PubMed

    Zhang, Jing; Wagh, Purva; Guay, Danielle; Sanchez-Pulido, Luis; Padhi, Bhaja K; Korzh, Vladimir; Andrade-Navarro, Miguel A; Akimenko, Marie-Andrée

    2010-07-08

    The early development of teleost paired fins is strikingly similar to that of tetrapod limb buds and is controlled by similar mechanisms. One early morphological divergence between pectoral fins and limbs is in the fate of the apical ectodermal ridge (AER), the distal epidermis that rims the bud. Whereas the AER of tetrapods regresses after specification of the skeletal progenitors, the AER of teleost fishes forms a fold that elongates. Formation of the fin fold is accompanied by the synthesis of two rows of rigid, unmineralized fibrils called actinotrichia, which keep the fold straight and guide the migration of mesenchymal cells within the fold. The actinotrichia are made of elastoidin, the components of which, apart from collagen, are unknown. Here we show that two zebrafish proteins, which we name actinodin 1 and 2 (And1 and And2), are essential structural components of elastoidin. The presence of actinodin sequences in several teleost fishes and in the elephant shark (Callorhinchus milii, which occupies a basal phylogenetic position), but not in tetrapods, suggests that these genes have been lost during tetrapod species evolution. Double gene knockdown of and1 and and2 in zebrafish embryos results in the absence of actinotrichia and impaired fin folds. Gene expression profiles in embryos lacking and1 and and2 function are consistent with pectoral fin truncation and may offer a potential explanation for the polydactyly observed in early tetrapod fossils. We propose that the loss of both actinodins and actinotrichia during evolution may have led to the loss of lepidotrichia and may have contributed to the fin-to-limb transition.

  3. [Attenuated total reflection-fourier transform infrared spectroscopic study of dried shark fin products].

    PubMed

    Han, Wan-qing; Luo, Hai-ying; Xian, Yan-ping; Luo, Dong-hui; Mu, Torng-na; Guo, Xin-dong

    2015-02-01

    Sixty-four pieces of shark fin dried products (including real, fake and artificial shark fin products) and real products coated with gelatin were rapidly and nondestructively analyzed by attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR). The characteristic of IR spectrograms among the above four kinds of samples were systematically studied and comparied, the results showed that the spectrograms of the same kind of samples were repeatable, and different kinds of shark fin products presented significant differences in the spectrograms, which mainly manifested as the specific absorption peaks of amido bonds in protein (1650, 1544 cm(-1)) and skeletal vibration in polysaccharide (1050 cm(-1)). The spectrograms of real shark fins were characterized by the strong absorption peaks of protein characteristic amide I and II absorbent (1650, 1544 cm(-1)) and relatively weak C--O--C vibration absorbent (1050 cm(-1)) owing to the high content of protein and relatively low level of polysaccharide. For fake shark fin products that were molded form by mixing together with the offcut of shark, collagen and other substances, the introduction of non-protein materials leaded to the weaker amido bonds absorbent than real products along with a 30 cm(-1) blue shift of amide I absorbent. Opposite to the real sample, the relatively strong absorption peak of polysaccharide (approximately 1047 cm(-1)) and barely existed amide absorbent were the key features of the spectrogram of artificial samples, which was synthersized by polysaccharide like sodium alginate. Real samples coated with gelatin, the peak strength of protein and polysaccharide were decreased simultaneously when the data collection was taken at the surface of sample, while the spectrogram presented no significant difference to real samples when the data was collected in the section. The results above indicated that by analyzing the characteristic of IR spectrograms and the value range of Apro

  4. Recent Improvements to the Finite-Fault Rupture Detector Algorithm: FinDer II

    NASA Astrophysics Data System (ADS)

    Smith, D.; Boese, M.; Heaton, T. H.

    2015-12-01

    Constraining the finite-fault rupture extent and azimuth is crucial for accurately estimating ground-motion in large earthquakes. Detecting and modeling finite-fault ruptures in real-time is thus essential to both earthquake early warning (EEW) and rapid emergency response. Following extensive real-time and offline testing, the finite-fault rupture detector algorithm, FinDer (Böse et al., 2012 & 2015), was successfully integrated into the California-wide ShakeAlert EEW demonstration system. Since April 2015, FinDer has been scanning real-time waveform data from approximately 420 strong-motion stations in California for peak ground acceleration (PGA) patterns indicative of earthquakes. FinDer analyzes strong-motion data by comparing spatial images of observed PGA with theoretical templates modeled from empirical ground-motion prediction equations (GMPEs). If the correlation between the observed and theoretical PGA is sufficiently high, a report is sent to ShakeAlert including the estimated centroid position, length, and strike, and their uncertainties, of an ongoing fault rupture. Rupture estimates are continuously updated as new data arrives. As part of a joint effort between USGS Menlo Park, ETH Zurich, and Caltech, we have rewritten FinDer in C++ to obtain a faster and more flexible implementation. One new feature of FinDer II is that multiple contour lines of high-frequency PGA are computed and correlated with templates, allowing the detection of both large earthquakes and much smaller (~ M3.5) events shortly after their nucleation. Unlike previous EEW algorithms, FinDer II thus provides a modeling approach for both small-magnitude point-source and larger-magnitude finite-fault ruptures with consistent error estimates for the entire event magnitude range.

  5. RNase E affects the expression of the acyl-homoserine lactone synthase gene sinI in Sinorhizobium meliloti.

    PubMed

    Baumgardt, Kathrin; Charoenpanich, Pornsri; McIntosh, Matthew; Schikora, Adam; Stein, Elke; Thalmann, Sebastian; Kogel, Karl-Heinz; Klug, Gabriele; Becker, Anke; Evguenieva-Hackenberg, Elena

    2014-04-01

    Quorum sensing of Sinorhizobium meliloti relies on N-acyl-homoserine lactones (AHLs) as autoinducers. AHL production increases at high population density, and this depends on the AHL synthase SinI and two transcriptional regulators, SinR and ExpR. Our study demonstrates that ectopic expression of the gene rne, coding for RNase E, an endoribonuclease that is probably essential for growth, prevents the accumulation of AHLs at detectable levels. The ectopic rne expression led to a higher level of rne mRNA and a lower level of sinI mRNA independently of the presence of ExpR, the AHL receptor, and AHLs. In line with this, IPTG (isopropyl-β-D-thiogalactopyranoside)-induced overexpression of rne resulted in a shorter half-life of sinI mRNA and a strong reduction of AHL accumulation. Moreover, using translational sinI-egfp fusions, we found that sinI expression is specifically decreased upon induced overexpression of rne, independently of the presence of the global posttranscriptional regulator Hfq. The 28-nucleotide 5' untranslated region (UTR) of sinI mRNA was sufficient for this effect. Random amplification of 5' cDNA ends (5'-RACE) analyses revealed a potential RNase E cleavage site at position +24 between the Shine-Dalgarno site and the translation start site. We postulate therefore that RNase E-dependent degradation of sinI mRNA from the 5' end is one of the steps mediating a high turnover of sinI mRNA, which allows the Sin quorum-sensing system to respond rapidly to changes in transcriptional control of AHL production.

  6. Condensation heat transfer and pressure drop of R-134a saturated vapour inside a brazed compact plate fin heat exchanger with serrated fin

    NASA Astrophysics Data System (ADS)

    Ramana Murthy, K. V.; Ranganayakulu, C.; Ashok Babu, T. P.

    2017-01-01

    This paper presents the experimental heat transfer coefficient and pressure drop measured during R-134a saturated vapour condensation inside a small brazed compact plate fin heat exchanger with serrated fin surface. The effects of saturation temperature (pressure), refrigerant mass flux, refrigerant heat flux, effect of fin surface characteristics and fluid properties are investigated. The average condensation heat transfer coefficients and frictional pressure drops were determined experimentally for refrigerant R-134a at five different saturated temperatures (34, 38, 40, 42 and 44 °C). A transition point between gravity controlled and forced convection condensation has been found for a refrigerant mass flux around 22 kg/m2s. In the forced convection condensation region, the heat transfer coefficients show a three times increase and 1.5 times increase in frictional pressure drop for a doubling of the refrigerant mass flux. The heat transfer coefficients show weak sensitivity to saturation temperature (Pressure) and great sensitivity to refrigerant mass flux and fluid properties. The frictional pressure drop shows a linear dependence on the kinetic energy per unit volume of the refrigerant flow. Correlations are provided for the measured heat transfer coefficients and frictional pressure drops.

  7. The pectoral fin muscles of the coelacanth Latimeria chalumnae: Functional and evolutionary implications for the fin-to-limb transition and subsequent evolution of tetrapods.

    PubMed

    Miyake, Tsutomu; Kumamoto, Minayori; Iwata, Masamitsu; Sato, Ryuichi; Okabe, Masataka; Koie, Hiroshi; Kumai, Nori; Fujii, Kenichi; Matsuzaki, Koji; Nakamura, Chiho; Yamauchi, Shinya; Yoshida, Kosuke; Yoshimura, Kohtaroh; Komoda, Akira; Uyeno, Teruya; Abe, Yoshitaka

    2016-09-01

    To investigate the morphology and evolutionary origin of muscles in vertebrate limbs, we conducted anatomical dissections, computed tomography and kinematic analyses on the pectoral fin of the African coelacanth, Latimeria chalumnae. We discovered nine antagonistic pairs of pronators and supinators that are anatomically and functionally distinct from the abductor and adductor superficiales and profundi. In particular, the first pronator and supinator pair represents mono- and biarticular muscles; a portion of the muscle fibers is attached to ridges on the humerus and is separated into two monoarticular muscles, whereas, as a biarticular muscle, the main body is inserted into the radius by crossing two joints from the shoulder girdle. This pair, consisting of a pronator and supinator, constitutes a muscle arrangement equivalent to two human antagonistic pairs of monoarticular muscles and one antagonistic pair of biarticular muscles in the stylopod between the shoulder and elbow joints. Our recent kinesiological and biomechanical engineering studies on human limbs have demonstrated that two antagonistic pairs of monoarticular muscles and one antagonistic pair of biarticular muscles in the stylopod (1) coordinately control output force and force direction at the wrist and ankle and (2) achieve a contact task to carry out weight-bearing motion and maintain stable posture. Therefore, along with dissections of the pectoral fins in two lungfish species, Neoceratodus forsteri and Protopterus aethiopicus, we discuss the functional and evolutionary implications for the fin-to-limb transition and subsequent evolution of tetrapods. Anat Rec, 299:1203-1223, 2016. © 2016 Wiley Periodicals, Inc.

  8. The Effect of Baffles on the Temperature Distribution and Heat-transfer Coefficients of Finned Cylinders

    NASA Technical Reports Server (NTRS)

    Schey, Oscar W; Rollin, Vern G

    1936-01-01

    This report presents the results of an investigation to determine the effect of baffles on the temperature distribution and the heat-transfer coefficient of finned cylinders. The tests were conducted in a 30-inch wind tunnel on electrically heated cylinders with fins of 0.25 and 0.31 inch pitch. The results of these tests showed that the use of integral baffles gave a reduction of 31.9 percent in the rear wall temperatures and an increase of 54.2 percent in the heat transfer coefficient as compared with a cylinder without baffles.

  9. Finned tube heat exchangers: state of the art for the air side

    SciTech Connect

    McQuiston, F. C.

    1980-01-01

    The findings of various investigators during the past ten years has greatly enhanced our ability to analyze, model, design, and optimize the finned tube heat exchangers so widely used in the HVAC business. The effect of rows, fin pitch, and other geometric parameters are now well understood and generalized heat transfer correlations are available. The relation between heat and mass transfer has been much better defined and good correlations have been developed. Some advances have also been made in modeling techniques especially where partially dry cooling and dehumidifying coils are involved. All of these factors are reviewed to concisely summarize what is now available to the heat exchanger analyst.

  10. Shuttle vertical fin flowfield by the direct simulation Monte Carlo method

    NASA Technical Reports Server (NTRS)

    Hueser, J. E.; Brock, F. J.; Melfi, L. T.

    1985-01-01

    The flow properties in a model flowfield, simulating the shuttle vertical fin, determined using the Direct Simulation Monte Carlo method. The case analyzed corresponds to an orbit height of 225 km with the freestream velocity vector orthogonal to the fin surface. Contour plots of the flowfield distributions of density, temperature, velocity and flow angle are presented. The results also include mean molecular collision frequency (which reaches 1/60 sec near the surface), collision frequency density (approaches 7 x 10 to the 18/cu m sec at the surface) and the mean free path (19 m at the surface).

  11. Visualization of the Design Space of a Caudal Fin with Hydro-Elastic Effect

    NASA Astrophysics Data System (ADS)

    Shimizu, Eriko; Jeong, Shinkyu; Obayashi, Shigeru; Isogai, Koji

    Performance of a fish caudal fin is brought out from many factors, such as the shape, the movement and the elasticity. The present study treats all of these factors simultaneously and attempts to visualize the complex design space using Kriging and SOM. As a result, the present study succeeded in visualizing the complex structure of the design space of the oscillating wing (caudal fin), and the combined effects of the design variables are shown. This data will become extremely useful for practical design of fish robots and other nautical machines.

  12. Experimental investigations and validation of two dimensional model for multistream plate fin heat exchangers

    NASA Astrophysics Data System (ADS)

    Goyal, Mukesh; Chakravarty, Anindya; Atrey, M. D.

    2017-03-01

    Experimental investigations are carried out using a specially developed three-layer plate fin heat exchanger (PFHE), with helium as the working fluid cooled to cryogenic temperatures using liquid nitrogen (LN2) as a coolant. These results are used for validation of an already proposed and reported numerical model based on finite volume analysis for multistream (MS) plate fin heat exchangers (PFHE) for cryogenic applications (Goyal et al., 2014). The results from the experiments are presented and a reasonable agreement is observed with the already reported numerical model.

  13. Indoor test for thermal performance evaluation of seven Elcam fin-tube solar collector configurations

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The test procedure used and the results obtained from an evaluation test program conducted to obtain thermal performance data on seven Elcam fin-tube solar collector configurations under simulated conditions are described. These tests were made using the Marshall Space Flight Center solar facilities. The Elcam fin-tube (liquid) solar collectors each consist of an absorber plate 5.9 inches wide by 83 inches long and a type M copper tube of 0.569 inch nominal inside diameter. No cover plate was used with any of the specimens. The uniqueness of each of the seven configurations is described, and tests were performed on each separate configuration.

  14. Evolutionary developmental transition from median to paired morphology of vertebrate fins: Perspectives from twin-tail goldfish.

    PubMed

    Abe, Gembu; Ota, Kinya G

    2016-12-07

    Vertebrate morphology has been evolutionarily modified by natural and/or artificial selection. The morphological variation of goldfish is a representative example. In particular, the twin-tail strain of ornamental goldfish shows highly diverged anal and caudal fin morphology: bifurcated anal and caudal fins. Recent molecular developmental genetics research revealed that a stop codon mutation in one of the two recently duplicated chordin genes is important for the highly diverged fin morphology of twin-tail goldfish. However, some issues still need to be discussed in the context of evolutionary developmental biology (evo-devo). For example, the bifurcated anal and caudal fins of twin-tail goldfish provided early researchers with insights into the origin of paired fins (pectoral and pelvic fins), but no subsequent researchers have discussed this topic. In addition, although the fossil jawless vertebrate species Euphanerops is also known to have had a bifurcated anal fin, how the bifurcated anal fin of twin-tail goldfish is related to that of fossil jawless vertebrate species has never been investigated. In this review, we present an overview of the early anatomical and embryological studies of twin-tail goldfish. Moreover, based on the similarity of embryonic features between the secondarily bifurcated competent stripe in twin-tail goldfish and the trunk bilateral competent stripes in conventional gnathostomes, we hypothesized that they share the same molecular developmental mechanisms. We also postulate that the bifurcated anal fin of Euphanerops might be caused by the same type of modification of dorsal-ventral patterning that occurs in the twin-tail goldfish, unlike the previously suggested evolutionary process that required the co-option of paired fin developmental mechanisms. Understanding the molecular developmental genetics of twin-tail goldfish allows us to further investigate the evolutionary developmental mechanisms of the origin of paired fins.

  15. Substrate specificity of TOR complex 2 is determined by a ubiquitin-fold domain of the Sin1 subunit.

    PubMed

    Tatebe, Hisashi; Murayama, Shinichi; Yonekura, Toshiya; Hatano, Tomoyuki; Richter, David; Furuya, Tomomi; Kataoka, Saori; Furuita, Kyoko; Kojima, Chojiro; Shiozaki, Kazuhiro

    2017-03-07

    The target of rapamycin (TOR) protein kinase forms multi-subunit TOR complex 1 (TORC1) and TOR complex 2 (TORC2), which exhibit distinct substrate specificities. Sin1 is one of the TORC2-specific subunit essential for phosphorylation and activation of certain AGC-family kinases. Here, we show that Sin1 is dispensable for the catalytic activity of TORC2, but its conserved region in the middle (Sin1CRIM) forms a discrete domain that specifically binds the TORC2 substrate kinases. Sin1CRIM fused to a different TORC2 subunit can recruit the TORC2 substrate Gad8 for phosphorylation even in the sin1 null mutant of fission yeast. The solution structure of Sin1CRIM shows a ubiquitin-like fold with a characteristic acidic loop, which is essential for interaction with the TORC2 substrates. The specific substrate-recognition function is conserved in human Sin1CRIM, which may represent a potential target for novel anticancer drugs that prevent activation of the mTORC2 substrates such as AKT.

  16. Substrate specificity of TOR complex 2 is determined by a ubiquitin-fold domain of the Sin1 subunit

    PubMed Central

    Tatebe, Hisashi; Murayama, Shinichi; Yonekura, Toshiya; Hatano, Tomoyuki; Richter, David; Furuya, Tomomi; Kataoka, Saori; Furuita, Kyoko; Kojima, Chojiro; Shiozaki, Kazuhiro

    2017-01-01

    The target of rapamycin (TOR) protein kinase forms multi-subunit TOR complex 1 (TORC1) and TOR complex 2 (TORC2), which exhibit distinct substrate specificities. Sin1 is one of the TORC2-specific subunit essential for phosphorylation and activation of certain AGC-family kinases. Here, we show that Sin1 is dispensable for the catalytic activity of TORC2, but its conserved region in the middle (Sin1CRIM) forms a discrete domain that specifically binds the TORC2 substrate kinases. Sin1CRIM fused to a different TORC2 subunit can recruit the TORC2 substrate Gad8 for phosphorylation even in the sin1 null mutant of fission yeast. The solution structure of Sin1CRIM shows a ubiquitin-like fold with a characteristic acidic loop, which is essential for interaction with the TORC2 substrates. The specific substrate-recognition function is conserved in human Sin1CRIM, which may represent a potential target for novel anticancer drugs that prevent activation of the mTORC2 substrates such as AKT. DOI: http://dx.doi.org/10.7554/eLife.19594.001 PMID:28264193

  17. Assessment of Caudal Fin Clips as a Non-lethal Technique for Predicting Muscle Tissue Mercury Concentrations in Largeouth Bass

    EPA Science Inventory

    The statistical relationship between total mercury (Hg) concentration in clips from the caudal fin and muscle tissue of largemouth bass (Micropterus salmoides) from 26 freshwater sites in Rhode Island, USA was developed and evaluated to determine the utility of fin clip analysis ...

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

    PubMed

    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.

  19. Effects of Fin Leading Edge Sweep on Shock-Shock Interaction at Mach 6

    NASA Technical Reports Server (NTRS)

    Berry, Scott A.; Nowak, Robert J.

    1996-01-01

    The effects of fin leading edge sweep on peak heating rates due to shock-shock interaction have been experimentally examined in the Langley 20-Inch Mach 6 Tunnel. The shock interaction was produced by the intersection of a planar incident shock (16.8 deg shock angle relative to the freestream, generated by a 9 deg wedge) with the bow shock formed around a O.5-inch diameter cylindrical leading edge fin. Heating distributions along the leading edge stagnation line have been obtained using densely spaced thin film resistive-type sensors. Schlieren images were obtained to illustrate the very complex shock-shock interactions. The fin leading edge sweep angle was varied from 15-degrees swept back to 45-degrees swept forward for a freestream unit Reynolds number of 2 x 10(exp 6)/ft. Two models were utilized during the study, one with 0.025-inch spacing between gage centers, and the other 0.015-inch spacing. Gage spatial resolution on the order of 0.015-in appeared to accurately capture the narrow spike in heating. Peak heating due to shock interaction was maximized when the fin was swept forward 15 deg and 25 deg, both promoting augmentations about 7 times the baseline value. The schlieren images for these cases revealed Type 4 and Type 3 interactions, respectively.

  20. Underlapped FinFET on insulator: Quasi3D analytical model

    NASA Astrophysics Data System (ADS)

    Kumari, Vandana; Sharmetha, K.; Saxena, Manoj; Gupta, Mridula

    2017-03-01

    The work presented in this paper analyse the influence of gate underlap region (present either near the source end or near the drain end) on the performance of FinFET using an efficient quasi 3D analytical model carried out by using separation of variable technique. Various parameters analysed in this work are: surface potential, electric field, threshold voltage (Vth), Subthreshold slope (SS), Drain Induced Barrier Lowering (DIBL) and sub-threshold drain current for different channel and underlap length. Analytical results obtained from the developed model are validated by 3-D ATLAS device simulation software results. Analog and RF performance metrics are also extracted for different lengths of underlap region and compared with the conventional FinFET through extensive device simulation. The influence of the back gate voltage on the electrostatics of the underlap FinFET is also investigated. The single stage common source amplifier using conventional and underlap FinFET has also been analysed. Apart from this, switching speed of the device is also investigated by comparing Ion/Ioff ratio and delay for different underlap and channel length.

  1. Synchronous seasonal change in fin whale song in the North Pacific.

    PubMed

    Oleson, Erin M; Širović, Ana; Bayless, Alexandra R; Hildebrand, John A

    2014-01-01

    Fin whale (Balaenoptera physalus) song consists of down-swept pulses arranged into stereotypic sequences that can be characterized according to the interval between successive pulses. As in blue (B. musculus) and humpback whales (Megaptera novaeangliae), these song sequences may be geographically distinct and may correlate with population boundaries in some regions. We measured inter-pulse intervals of fin whale songs within year-round acoustic datasets collected between 2000 and 2006 in three regions of the eastern North Pacific: Southern California, the Bering Sea, and Hawaii. A distinctive song type that was recorded in all three regions is characterized by singlet and doublet inter-pulse intervals that increase seasonally, then annually reset to the same shorter intervals at the beginning of each season. This song type was recorded in the Bering Sea and off Southern California from September through May and off Hawaii from December through April, with the song interval generally synchronized across all monitoring locations. The broad geographic and seasonal occurrence of this particular fin whale song type may represent a single population broadly distributed throughout the eastern Pacific with no clear seasonal migratory pattern. Previous studies attempting to infer population structure of fin whales in the North Pacific using synchronous individual song samples have been unsuccessful, likely because they did not account for the seasonal lengthening in song intervals observed here.

  2. Analysis and design of a flat central finned-tube radiator

    NASA Technical Reports Server (NTRS)

    Auer, B. M.; Haller, H. C.; Krebs, R. P.

    1971-01-01

    Computer program based on fixed conductance parameter yields minimum weight design. Second program employs variable conductance parameter and variable ratio of fin length to tube outside radius, and is used for radiator designs with geometric limitations. Major outputs of the two programs are given.

  3. Transonic solutions of a wing/pylon/finned store using hybrid domain decomposition

    NASA Technical Reports Server (NTRS)

    Newman, James C., III; Baysal, Oktay

    1992-01-01

    Transonic Euler calculations about a complex multicomponent configuration are presented. The 3D Euler equations are solved utilizing an upwind-biased, alternating direction implicit, approximately factored, multigrid algorithm. Computational results are compared to experimental data of the finned store in a carriage position.

  4. Geometric sensitivity of electrochemical fin shape on three dimensional microstructure network conductivity analysis

    NASA Astrophysics Data System (ADS)

    DeGostin, Matthew B.; Nakajo, Arata; Cassenti, Brice N.; Peracchio, Aldo A.; Nelson, George J.; Chiu, Wilson K. S.

    2015-09-01

    A rapid microstructural assessment tool has previously been developed to support electrode design efforts by modeling charge transport and surface electrochemistry through networks of transport channels represented by ideal axisymmetric electrochemical fins. Analytical solutions have allowed these fins to take the form of a positive curvature sphere, a neutral curvature conical frustum, and a negative curvature smooth exponential profile. The present paper aims to enhance the geometric sensitivity of the network modeling tool by fitting ideal fin shapes to individual channels within the microstructure via dimensionless parameters describing channel morphology. The tool is used to directly compute effective transport properties of a range of microstructures, including artificial packed sphere structures and real solid oxide fuel cell electrode and gas membrane material microstructures imaged by X-ray nanotomography. Results obtained are compared with detailed finite element analyses and predictions from percolation theory. It is shown that the model can capture transport losses associated with microstructure on the particle scale, highlighting its potential as a less computationally demanding complement to detailed numerical models such as finite element or lattice Boltzmann methods for preliminary electrode design screening. Results also emphasize the importance of capturing local microstructural effects of specific transport networks, as electrochemical fin results provide more accurate performance predictions than percolation theory for structures near their percolation threshold.

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

    PubMed Central

    Mondo, Kiyo; Hammerschlag, Neil; Basile, Margaret; Pablo, John; Banack, Sandra A.; Mash, Deborah C.

    2012-01-01

    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. PMID:22412816

  6. Creatine supplementation improves the anaerobic performance of elite junior fin swimmers.

    PubMed

    Juhász, Imre; Györe, I; Csende, Zs; Rácz, L; Tihanyi, J

    2009-09-01

    The objective of this study was to determine whether creatine supplementation (CrS) could improve mechanical power output, and swimming performance in highly trained junior competitive fin swimmers. Sixteen male fin swimmers (age:15.9+/-1.6 years) were randomly and evenly assigned to either a creatine (CR, 4x5 g/day creatine monohydrate for 5 days) or placebo group (P, same dose of a dextrose-ascorbic acid placebo) in a double-blind research. Before and after CrS the average power output was determined by a Bosco-test and the swimming time was measured in two maximal 100 m fin swims. After five days of CrS the average power of one minute continuous rebound jumps increased by 20.2%. The lactate concentration was significantly less after 5 minutes restitution at the second measurement in both groups. The swimming time was significantly reduced in both first (pre: 50.69+/-1.41 s; post: 48.86+/-1.34 s) and second (pre: 50.39+/-1.38 s; post: 48.53+/-1.35 s) sessions of swimming in CR group, but remained almost unchanged in the P group.The results of this study indicate that five day Cr supplementation enhances the dynamic strength and may increase anaerobic metabolism in the lower extremity muscles, and improves performance in consecutive maximal swims in highly trained adolescent fin swimmers.

  7. Mature osteoblasts dedifferentiate in response to traumatic bone injury in the zebrafish fin and skull.

    PubMed

    Geurtzen, Karina; Knopf, Franziska; Wehner, Daniel; Huitema, Leonie F A; Schulte-Merker, Stefan; Weidinger, Gilbert

    2014-06-01

    Zebrafish have an unlimited capacity to regenerate bone after fin amputation. In this process, mature osteoblasts dedifferentiate to osteogenic precursor cells and thus represent an important source of newly forming bone. By contrast, differentiated osteoblasts do not appear to contribute to repair of bone injuries in mammals; rather, osteoblasts form anew from mesenchymal stem cells. This raises the question whether osteoblast dedifferentiation is specific to appendage regeneration, a special feature of the lepidotrichia bone of the fish fin, or a process found more generally in fish bone. Here, we show that dedifferentiation of mature osteoblasts is not restricted to fin regeneration after amputation, but also occurs during repair of zebrafish fin fractures and skull injuries. In both models, mature osteoblasts surrounding the injury downregulate the expression of differentiation markers, upregulate markers of the pre-osteoblast state and become proliferative. Making use of photoconvertible Kaede protein as well as Cre-driven genetic fate mapping, we show that osteoblasts migrate to the site of injury to replace damaged tissue. Our findings suggest a fundamental role for osteoblast dedifferentiation in reparative bone formation in fish and indicate that adult fish osteoblasts display elevated cellular plasticity compared with mammalian bone-forming cells.

  8. Cyanobacterial neurotoxin β-N-methylamino-L-alanine (BMAA) in shark fins.

    PubMed

    Mondo, Kiyo; Hammerschlag, Neil; Basile, Margaret; Pablo, John; Banack, Sandra A; Mash, Deborah C

    2012-02-01

    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.

  9. Control of unsteady shock-induced turbulent boundary layer separation upstream of blunt fins

    NASA Technical Reports Server (NTRS)

    Kleifges, K.; Dolling, D. S.

    1993-01-01

    Fluctuating wall pressure measurements have been made on centerline upstream of blunt fins in a Mach 5 turbulent boundary layer. Standard time series analysis and conditional sampling algorithms have been used to examine the effects of leading edge sweepback, leading edge shape, and fin root modifications on the fluctuating pressures. Leading edge sweep considerably reduces the mean and rms pressure loading at the fin root, the extent of the region of unsteady separation shock motion, and the separation length. The frequency of pressure fluctuations in the intermittent region increases with leading edge sweepback, while the spectral content of pressure fluctuations in the separated region is virtually unchanged by leading edge sweep. A swept hemicylindrically blunted root fillet reduces the centerline upstream influence and intermittent region length by 50 percent, and reduces the mean and rms pressure loading at the fin root by about 75 percent and 95 percent respectively. Experiments using hemicylindrical, wedge shaped and flat leading edges show that while separated flow scales increase with increasing 'bluntness', intermittent region length and root loading decrease, and separation shock frequency increases.

  10. FINS: A Guide to the LaConner School District's Program In Fishing Industry Specialization.

    ERIC Educational Resources Information Center

    Avery, Paul J.; And Others

    Fishing Industry Specialization, or FINS, is a 2-year alternative education program designed in 1979 by the LaConner (Washington) School District to encourage high school completion by students wanting to enter the fishing industry. With encouragement from the Swinomish Indian Tribe and help from an active citizens advisory board, school officials…

  11. Quantitative assessment of the regenerative and mineralogenic performances of the zebrafish caudal fin

    PubMed Central

    Cardeira, João; Gavaia, Paulo J.; Fernández, Ignacio; Cengiz, Ibrahim Fatih; Moreira-Silva, Joana; Oliveira, Joaquim Miguel; Reis, Rui L.; Cancela, M. Leonor; Laizé, Vincent

    2016-01-01

    The ability of zebrafish to fully regenerate its caudal fin has been explored to better understand the mechanisms underlying de novo bone formation and to develop screening methods towards the discovery of compounds with therapeutic potential. Quantifying caudal fin regeneration largely depends on successfully measuring new tissue formation through methods that require optimization and standardization. Here, we present an improved methodology to characterize and analyse overall caudal fin and bone regeneration in adult zebrafish. First, regenerated and mineralized areas are evaluated through broad, rapid and specific chronological and morphometric analysis in alizarin red stained fins. Then, following a more refined strategy, the intensity of the staining within a 2D longitudinal plane is determined through pixel intensity analysis, as an indicator of density or thickness/volume. The applicability of this methodology on live specimens, to reduce animal experimentation and provide a tool for in vivo tracking of the regenerative process, was successfully demonstrated. Finally, the methodology was validated on retinoic acid- and warfarin-treated specimens, and further confirmed by micro-computed tomography. Because it is easily implementable, accurate and does not require sophisticated equipment, the present methodology will certainly provide valuable technical standardization for research in tissue engineering, regenerative medicine and skeletal biology. PMID:27991522

  12. Numerical study of finned heat pipe-assisted latent heat thermal energy storage system

    NASA Astrophysics Data System (ADS)

    Tiari, Saeed; Qiu, Songgang; Mahdavi, Mahboobe

    2014-11-01

    In the present study the thermal characteristics of a finned heat pipe-assisted latent heat thermal energy storage system are investigated numerically. A transient two dimensional finite volume based model employing enthalpy-porosity technique is implemented to analyze the performance of a thermal energy storage unit with square container and high melting temperature phase change material. The effects of heat pipe spacing, fin length and numbers as well as the influence of natural convection on the thermal response of the thermal energy storage unit have been studied. The obtained results reveal that the natural convection has considerable effect on the melting process of the phase change material. Increasing the number of heat pipes leads to the increase of melting rate and the decrease of base wall temperature. Also, the increase of fin length results in the decrease of temperature difference within the phase change material in the container, providing more uniform temperature distribution. Furthermore, it is showed that the number of fins does not affect the performance of the system considerably.

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

    PubMed

    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.

  14. A 0.7-V Opamp in Scaled Low-Standby-Power FinFET Technology

    NASA Astrophysics Data System (ADS)

    O'Uchi, Shin-Ichi; Endo, Kazuhiko; Matsukawa, Takashi; Liu, Yongxun; Nakagawa, Tadashi; Ishikawa, Yuki; Tsukada, Junichi; Yamauchi, Hiromi; Sekigawa, Toshihiro; Koike, Hanpei; Sakamoto, Kunihiro; Masahara, Meishoku

    This paper demonstrates a FinFET operational amplifier (opamp), which is suitable to be integrated with digital circuits in a scaled low-standby-power (LSTP) technology and operates at extremely low voltage. The opamp is consisting of an adaptive threshold-voltage (Vt) differential pair and a low-voltage source follower using independent-double-gate- (IDG-) FinFETs. These two components enable the opamp to extend the common-mode voltage range (CMR) below the nominal Vt even if the supply voltage is less than 1.0V. The opamp was implemented by our FinFET technology co-integrating common-DG- (CDG-) and IDG-FinFETs. More than 40-dB DC gain and 1-MHz gain-bandwidth product in the 500-mV-wide input CMR at the supply voltage of 0.7V was estimated with SPICE simulation. The fabricated chip successfully demonstrated the 0.7-V operation with the 480-mV-wide CMR, even though the nominal Vt was 400mV.

  15. The role of tip deflection on the thrust produced by rigid flapping fins

    NASA Astrophysics Data System (ADS)

    Huera-Huarte, Francisco; Gharib, Morteza

    2015-11-01

    It is well known that flexibility plays an important role in the propulsion performance and efficiency of oscillating fin based propulsion systems. Compliance is one of the aspects that has received more attention, as it seems to be a common feature in nature's flyers and swimmers. Active control strategies are also common in nature. We will show how by deflecting only the last 10% of length of a rigid fin, at the tip, the thrust can be changed dramatically. This can be thought as an alternative to passive flexibility for controlling very efficiently the momentum transfer in the wake and therefore the thrust generation when flapping. A series of experiments have been carried with a robotic fin that allowed the control of its flapping kinematics as well as the control of the motions of its tip independently. We will be showing situations in which the tip was kept at a certain fixed position during a power stroke, and others in which it moved either in-phase or out-of-phase with the fin. The observed thrust and wake dynamics will be discussed for all these situations. The authors would like to acknowledge the financial support provided by the Gordon and Betty Moore Foundation and by the Spanish Ministerio de Economia y competitividad (MINECO) through grant DPI2012-37904. Visiting Associate in Aerospace, California Institute of Technology.

  16. Unsteady Aerodynamic Simulations of a Finned Projectile at a Supersonic Speed With Jet Interaction

    DTIC Science & Technology

    2014-06-01

    The conical nose is 2.84 cal. long and is followed by a 7.16-cal cylindrical section. Four rectangular planform fins are located on the back end of...Turbulence Modeling for Unsteady Flow With Acoustic Resonance ; AIAA Paper 00-0473. Presented at 38th AIAA Aerospace Sciences Conference, Reno, NV

  17. Development of a robotic endoscope that locomotes in the colon with flexible helical fins.

    PubMed

    Shikanai, M; Murai, N; Itoh, K; Ishii, H; Takanishi, A; Tanoue, K; Ieiri, S; Konishi, K; Hasizume, M

    2009-01-01

    The purpose of this study was to develop a robotic endoscope that is low invasive, easy to operate and capable of locomotion from the rectum to the appendix in the human body. We believe that it would contribute to relieving pain in patients. We therefore developed a robotic endoscope that consists of a front and rear body with clockwise and anticlockwise helical fins, respectively. The front and rear bodies are connected via a DC motor. This robot moves forward in the colon by rotating the front body in the clockwise direction and the rear body in the anticlockwise direction. In addition, the radius of each helical fin can be changed by blowing air into a balloon implemented under each fin using an air compressor. Before experiments with animals, we performed experiments to evaluate the mechanical performance and safety of the robot. We confirmed that the maximum radius of the fins was less than the maximum radius of the colon by blowing air continuously into the balloons. We then confirmed that the robot can locomote in the colon without invasion of scratch and make short hole by performing an in-vivo experiment in live swine.

  18. Geometric sensitivity of electrochemical fin shape on three dimensional microstructure network conductivity analysis

    SciTech Connect

    DeGostin, Matthew B.; Nakajo, Arata; Cassenti, Brice N.; Peracchio, Aldo A.; Nelson, George J.; Chiu, Wilson K. S.

    2015-09-01

    A rapid microstructural assessment tool has previously been developed to support electrode design efforts by modeling charge transport and surface electrochemistry through networks of transport channels represented by ideal axisymmetric electrochemical fins. Analytical solutions have allowed these fins to take the form of a positive curvature sphere, a neutral curvature conical frustum, and a negative curvature smooth exponential profile. Our paper aims to enhance the geometric sensitivity of the network modeling tool by fitting ideal fin shapes to individual channels within the microstructure via dimensionless parameters describing channel morphology. The tool is used to directly compute effective transport properties of a range of microstructures, including artificial packed sphere structures and real solid oxide fuel cell electrode and gas membrane material microstructures imaged by X-ray nanotomography. The results we obtained are compared with detailed finite element analyses and predictions from percolation theory. It is shown that the model can capture transport losses associated with microstructure on the particle scale, highlighting its potential as a less computationally demanding complement to detailed numerical models such as finite element or lattice Boltzmann methods for preliminary electrode design screening. Results also emphasize the importance of capturing local microstructural effects of specific transport networks, as electrochemical fin results provide more accurate performance predictions than percolation theory for structures near their percolation threshold.

  19. Endoskeletal structure in Cheirolepis (Osteichthyes, Actinopterygii), An early ray-finned fish.

    PubMed

    Giles, Sam; Coates, Michael I; Garwood, Russell J; Brazeau, Martin D; Atwood, Robert; Johanson, Zerina; Friedman, Matt

    2015-09-01

    As the sister lineage of all other actinopterygians, the Middle to Late Devonian (Eifelian-Frasnian) Cheirolepis occupies a pivotal position in vertebrate phylogeny. Although the dermal skeleton of this taxon has been exhaustively described, very little of its endoskeleton is known, leaving questions of neurocranial and fin evolution in early ray-finned fishes unresolved. The model for early actinopterygian anatomy has instead been based largely on the Late Devonian (Frasnian) Mimipiscis, preserved in stunning detail from the Gogo Formation of Australia. Here, we present re-examinations of existing museum specimens through the use of high-resolution laboratory- and synchrotron-based computed tomography scanning, revealing new details of the neuro-cranium, hyomandibula and pectoral fin endoskeleton for the Eifelian Cheirolepis trailli. These new data highlight traits considered uncharacteristic of early actinopterygians, including an uninvested dorsal aorta and imperforate propterygium, and corroborate the early divergence of Cheirolepis within actinopterygian phylogeny. These traits represent conspicuous differences between the endoskeletal structure of Cheirolepis and Mimipiscis. Additionally, we describe new aspects of the parasphenoid, vomer and scales, most notably that the scales display peg-and-socket articulation and a distinct neck. Collectively, these new data help clarify primitive conditions within ray-finned fishes, which in turn have important implications for understanding features likely present in the last common ancestor of living osteichthyans.

  20. Transient laminin beta 1a Induction Defines the Wound Epidermis during Zebrafish Fin Regeneration.

    PubMed

    Chen, Chen-Hui; Merriman, Alexander F; Savage, Jeremiah; Willer, Jason; Wahlig, Taylor; Katsanis, Nicholas; Yin, Viravuth P; Poss, Kenneth D

    2015-08-01

    The first critical stage in salamander or teleost appendage regeneration is creation of a specialized epidermis that instructs growth from underlying stump tissue. Here, we performed a forward genetic screen for mutations that impair this process in amputated zebrafish fins. Positional cloning and complementation assays identified a temperature-sensitive allele of the ECM component laminin beta 1a (lamb1a) that blocks fin regeneration. lamb1a, but not its paralog lamb1b, is sharply induced in a subset of epithelial cells after fin amputation, where it is required to establish and maintain a polarized basal epithelial cell layer. These events facilitate expression of the morphogenetic factors shha and lef1, basolateral positioning of phosphorylated Igf1r, patterning of new osteoblasts, and regeneration of bone. By contrast, lamb1a function is dispensable for juvenile body growth, homeostatic adult tissue maintenance, repair of split fins, or renewal of genetically ablated osteoblasts. fgf20a mutations or transgenic Fgf receptor inhibition disrupt lamb1a expression, linking a central growth factor to epithelial maturation during regeneration. Our findings reveal transient induction of lamb1a in epithelial cells as a key, growth factor-guided step in formation of a signaling-competent regeneration epidermis.

  1. Numerical Analysis on Adsorption Characteristics of Activated Carbon/Ethanol Pair in Finned Tube Type Adsorber

    NASA Astrophysics Data System (ADS)

    Makimoto, Naoya; Kariya, Keishi; Koyama, Shigeru

    The cycle performance of adsorption cooling system depends on the thermophysical properties of the adsorbent/refrigerant pair and configuration of the adsorber/desorber heat exchanger. In this study, a twodimensional analysis is carried out in order to clarify the performance of the finned tube type adsorber/desorber heat exchanger using a highly porous activated carbon powder (ACP)/ethanol pair. The simulation results show that the average cooling capacity per unit volume of adsorber/desorber heat exchanger and coefficient of performance (COP) can be improved by optimizing fin thickness, fin height, fin pitch and tube diameter. The performance of a single stage adsorption cooling system using ACP/ethanol pair is also compared with that of activated carbon fiber (ACF)/ethanol pair. It is found that the cooling capacities of each adsorbent/refrigerant pair increase with the decrease of adsorption/desorption time and the cooling capacity of ACP/ethanol pair is approximately 2.5 times as much as that of ACF/ethanol pair. It is also shown that COP of ACP/ethanol pair is superior to that of ACF/ethanol pair.

  2. Study on turbulent flow and heat transfer performance of tubes with internal fins in EGR cooler

    NASA Astrophysics Data System (ADS)

    Liu, Lin; Ling, Xiang; Peng, Hao

    2015-01-01

    In this paper, flow and heat transfer performances of the tubes with internal longitudinal fins in Exhaust Gas Recirculation (EGR ) cooler were investigated by three-dimension computation and experiment . Each test tube was a single-pipe structure, without inner tube. Three-dimension computation was performed to determine the thermal characteristics difference between the two kinds of tubes, that is, the tube with an inner solid staff as a blocked structure and the tube without the blocked structure. The effects of fin width and fin height on heat transfer and flow are examined. For proving the validity of numerical method, the calculated results were compared with corresponding experimental data. The tube-side friction factor and heat transfer coefficient were examined. As a result, the maximum deviations between the numerical results and the experimental data are approximately 5.4 % for friction factor and 8.6 % for heat transfer coefficient, respectively. It is found that two types of internally finned tubes enhance significantly heat transfer. The heat transfer of the tube with blocked structure is better, while the pressure drop of the tube without blocked structure is lower. The comprehensive performance of the unblocked tube is better to applied in EGR cooler.

  3. Genomic and structural investigation on dolphin morbillivirus (DMV) in Mediterranean fin whales (Balaenoptera physalus)

    PubMed Central

    Beffagna, Giorgia; Centelleghe, Cinzia; Franzo, Giovanni; Di Guardo, Giovanni; Mazzariol, Sandro

    2017-01-01

    Dolphin morbillivirus (DMV) has been deemed as one of the most relevant threats for fin whales (Balaenoptera physalus) being responsible for a mortality outbreak in the Mediterranean Sea in the last years. Knowledge of the complete viral genome is essential to understand any structural changes that could modify virus pathogenesis and viral tissue tropism. We report the complete DMV sequence of N, P/V/C, M, F and H genes identified from a fin whale and the comparison of primary to quaternary structure of proteins between this fin whale strain and some of those isolated during the 1990–‘92 and the 2006–‘08 epidemics. Some relevant substitutions were detected, particularly Asn52Ser located on F protein and Ile21Thr on N protein. Comparing mutations found in the fin whale DMV with those occurring in viral strains of other cetacean species, some of them were proven to be the result of diversifying selection, thus allowing to speculate on their role in host adaptation and on the way they could affect the interaction between the viral attachment and fusion with the target host cells. PMID:28134317

  4. Stability and control characteristics of a monoplanar missile configuration with triform-tail-fin arrangements at Mach numbers from 1.70 to 2.86

    NASA Technical Reports Server (NTRS)

    Lamb, M.

    1981-01-01

    A wind-tunnel missile model with either a lower vertical tail fin with a pair of horizontal fins having 0 deg, 22.5 deg, or 30 deg dihedral or an upper vertical tail fin with horizontal fins having 0 deg, -22.5 deg, or -30 deg dihedral was investigated. The results indicated that those configurations with horizontal fins at or below the horizontal plane had nearly linear pitching-moment characteristics, while those with the horizontal fins above the horizontal plane experienced pitch-up which increased with increasing horizontal-fin-dihedral angle. At zero angle of attack, the configurations were directionally stable at most test Mach numbers. Generally, those configurations with the upper vertical fin had positive effective dihedral at zero angle of attack, while those with he lower vertical fin had negative effective dihedral. For roll control, three deflected tail fins produced more total roll control than two horizontal fins. For yaw control, three tail fins deflected equally or differentially produced more total yaw control than the single vertical fin.

  5. Local Heat Transfer for Finned-Tube Heat Exchangers using Oval Tubes

    SciTech Connect

    O'Brien, James Edward; Sohal, Manohar Singh

    2000-08-01

    This paper presents the results of an experimental study of forced convection heat transfer in a narrow rectangular duct fitted with either a circular tube or an elliptical tube in crossflow. The duct was designed to simulate a single passage in a fin-tube heat exchanger. Heat transfer measurements were obtained using a transient technique in which a heated airflow is suddenly introduced to the test section. High-resolution local fin-surface temperature distributions were obtained at several times after initiation of the transient using an imaging infrared camera. Corresponding local fin-surface heat transfer coefficient distributions were then calculated from a locally applied one-dimensional semi-infinite inverse heat conduction model. Heat transfer results were obtained over an airflow rate ranging from 1.56 x 10-3 to 15.6 x 10-3 kg/s. These flow rates correspond to a duct-height Reynolds number range of 630 – 6300 with a duct height of 1.106 cm and a duct width-toheight ratio, W/H, of 11.25. The test cylinder was sized such that the diameter-to-duct height ratio, D/H is 5. The elliptical tube had an aspect ratio of 3:1 and a/H equal to 4.33. Results presented in this paper reveal visual and quantitative details of local fin-surface heat transfer distributions in the vicinity of circular and oval tubes and their relationship to the complex horseshoe vortex system that forms in the flow stagnation region. Fin surface stagnation-region Nusselt numbers are shown to be proportional to the square-root of Reynolds number.

  6. A strange and surprising debate: mountains, original sin and 'science' in seventeenth-century England.

    PubMed

    Wragge-Morley, Alexander

    2009-06-01

    It could come as a shock to learn that some seventeenth-century men of science and learning thought that mountains were bad. Even more alarmingly, some thought that God had imposed them on the earth to punish man for his sins. By the end of the seventeenth century, surprisingly many English natural philosophers and theologians were engaged in a debate about whether mountains were 'good' or 'bad', useful or useless. At stake in this debate were not just the careers of its participants, but arguments about the best ways of looking at and reckoning with 'nature' itself.

  7. Measurement of sin(2beta) in Tree-dominated B^0-Decays and Ambiguity Removal

    SciTech Connect

    Lacker, Heiko

    2007-03-05

    The most recent results from the B-factories on the time-dependent CP asymmetries measured in B{sup 0}-decays mediated by b {yields} c{bar c}s quark-transitions are reviewed. The Standard Model interpretation of the results in terms of the parameter sin 2{beta} leads to a four-fold ambiguity on the unitarity triangle {beta} which can be reduced to a two-fold ambiguity by measuring the sign of the parameter cos 2{beta}. The results on cos 2{beta} obtained so far are reviewed.

  8. Measurement of Sin(2beta) in Tree Dominated B0 Decays And Ambiguity Removal

    SciTech Connect

    Lacker, H.; /Dresden, Tech. U.

    2007-11-20

    The most recent results from the B-factories on the time-dependent CP asymmetries measured in B{sup 0}-decays mediated by b {yields} c{bar c}s quark-transitions are reviewed. The Standard Model interpretation of the results in terms of the parameter sin 2{beta} leads to a four-fold ambiguity on the unitarity triangle {beta} which can be reduced to a two-fold ambiguity by measuring the sign of the parameter cos 2{beta}. The results on cos2{beta} obtained so far are reviewed.

  9. Totally asymmetric simple exclusion process with entrance rate sin(x)

    NASA Astrophysics Data System (ADS)

    Liang, Yifan; Chen, Xiaoyu; Liu, Yanna; Xiao, Song

    2017-03-01

    In recently, traffic jams have become the focus and one used different approaches to study them. In this paper, the function of sin(x) is used to simulate the enter rate α of the peak period to work. The mean field approach has been used to calculate the phase diagrams and these results were compared with Monte Carlo simulations. They are good agreement. When traffic accidents occur at the exit, the exit rate β will be less than 1 and traffic jams will occur. Different fixed the exit rate β is used to calculate the additional energy consumption. The additional energy consumption will increase with the reducing of the exit rate β.

  10. Effects of Tumor Necrosis Factor Alpha on Sin Nombre Virus Infection In Vitro

    PubMed Central

    Khaiboullina, Svetlana F.; Netski, Dale M.; Krumpe, Peter; St. Jeor, Stephen C.

    2000-01-01

    Previous data indicate that immune mechanisms may be involved in developing capillary leakage during Sin Nombre virus (SNV) infection. Therefore, we investigated production of tumor necrosis factor alpha (TNF-α) by human alveolar macrophages and human umbilical vein endothelial cells (HUVEC) after infection with SNV. In addition, we examined the effect of TNF-α on HUVEC monolayer leakage. Our results reveal that although TNF-α decreases accumulation of viral nucleoproteins, TNF-α levels do not change in SNV-infected cells. In addition, supernatants from SNV-infected human alveolar macrophages did not cause a significant increase in endothelial monolayer permeability. PMID:11090198

  11. First Insertions of Carbene Ligands into Ge-N and Si-N Bonds.

    PubMed

    Álvarez-Rodríguez, Lucía; Cabeza, Javier A; García-Álvarez, Pablo; Gómez-Gallego, Mar; Merinero, Alba D; Sierra, Miguel A

    2017-03-28

    The insertion of carbene ligands into Ge-N (three examples) and Si-N (one example) bonds has been achieved for the first time by treating Fischer carbene complexes (M=W, Cr) with bulky amidinatotetrylenes (E=Ge, Si). These reactions, which start with a nucleophilic attack of the amidinatotetrylene heavier group 14 atom to the carbene C atom, proceed through a stereoselective insertion of the carbene fragment into an E-N bond of the amidinatotetrylene ENCN four-membered ring, leading to [M(CO)5 L] derivatives in which L belongs to a novel family of tetrylene ligands comprising an ECNCN five-membered ring.

  12. Rajiform locomotion: three-dimensional kinematics of the pectoral fin surface during swimming in the freshwater stingray Potamotrygon orbignyi.

    PubMed

    Blevins, Erin L; Lauder, George V

    2012-09-15

    Rajiform locomotion in fishes is dominated by distinctive undulations of expanded pectoral fins. Unlike other fishes, which typically interact with the fluid environment via multiple fins, undulating rays modulate a single control surface, the pectoral disc, to perform pelagic locomotion, maneuvering and other behaviors. Complex deformations of the broad, flexible pectoral fins occur as the undulating wave varies in three dimensions; pectoral fin kinematics and changes in waveform with swimming speed cannot be fully quantified by two-dimensional analyses of the fin margin. We present the first three-dimensional analysis of undulatory rajiform locomotion in a batoid, the freshwater stingray Potamotrygon orbignyi. Using three cameras (250 frames s(-1)), we gathered three-dimensional excursion data from 31 points on the pectoral fin during swimming at 1.5 and 2.5 disc lengths s(-1), describing the propulsive wave and contrasting waveforms between swimming speeds. Only a relatively small region of the pectoral fin (~25%) undulates with significant amplitude (>0.5 cm). Stingrays can maintain extreme lateral curvature of the distal fin margin in opposition to induced hydrodynamic loads, 'cupping' the edge of the pectoral fin into the flow, with potential implications for drag reduction. Wave amplitude increases across both anteroposterior and mediolateral fin axes. Along the anteroposterior axis, amplitude increases until the wave reaches mid-disc and then remains constant, in contrast to angulliform patterns of continuous amplitude increase. Increases in swimming speed are driven by both wave frequency and wavespeed, though multivariate analyses reveal a secondary role for amplitude.

  13. The reliability and validity of assessing medio-lateral patellar position: a systematic review.

    PubMed

    Smith, Toby O; Davies, Leigh; Donell, Simon T

    2009-08-01

    Medio-lateral patellar position is regarded as a sign of patellofemoral pain syndrome and patellar instability. Its assessment is important in accurately performing patellofemoral therapeutic taping techniques. The purpose of this paper is to systematically review the literature to determine the reliability and validity of evaluating medio-lateral patellar position. An electronic database search was performed accessing AMED, British Nursing Index, CINAHL, the Cochrane database, EMBASE, Ovid Medline, Physiotherapy Evidence Database (PEDro), PubMed and Zetoc to July 2008. Conference proceedings and grey literature were also scrutinised for future publications. All human subject, clinical trials, assessing the inter- or intra-tester reliability, or the criterion validity, were included. A CASP tool was employed to evaluate methodological quality. Nine papers including 237 patients (306 knees) were reviewed. The findings of this review suggest that the intra-tester reliability of assessing medio-lateral patellar position is good, but that inter-tester reliability is variable. The criterion validity of this test is at worse moderate. These are based on a limited evidence-base. Further study is recommended to compare the McConnell (1986) [McConnell J. The management of chondromalacia patellae: a long term solution. Australian Journal of Physiotherapy 1986;32(4):215-23] and Herrington (2002) [Herrington LC. The inter-tester reliability of a clinical measurement used to determine the medial/lateral orientation of the patella. Manual Therapy 2002;7(3):163-7] methods of assessing medio-lateral patellar position in patients with well-defined patellofemoral disorders.

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

    NASA Astrophysics Data System (ADS)

    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

  15. An SINS/GNSS Ground Vehicle Gravimetry Test Based on SGA-WZ02.

    PubMed

    Yu, Ruihang; Cai, Shaokun; Wu, Meiping; Cao, Juliang; Zhang, Kaidong

    2015-09-16

    In March 2015, a ground vehicle gravimetry test was implemented in eastern Changsha to assess the repeatability and accuracy of ground vehicle SINS/GNSS gravimeter-SGA-WZ02. The gravity system developed by NUDT consisted of a Strapdown Inertial Navigation System (SINS), a Global Navigation Satellite System (GNSS) remote station on test vehicle, a GNSS static master station on the ground, and a data logging subsystem. A south-north profile of 35 km along the highway in eastern Changsha was chosen and four repeated available measure lines were obtained. The average speed of a vehicle is 40 km/h. To assess the external ground gravity disturbances, precise ground gravity data was built by CG-5 precise gravimeter as the reference. Under relative smooth conditions, internal accuracy among repeated lines shows an average agreement at the level of 1.86 mGal for half wavelengths about 1.1 km, and 1.22 mGal for 1.7 km. The root-mean-square (RMS) of difference between calculated gravity data and reference data is about 2.27 mGal/1.1 km, and 1.74 mGal/1.7 km. Not all of the noises caused by vehicle itself and experiments environments were eliminated in the primary results. By means of selecting reasonable filters and improving the GNSS observation conditions, further developments in ground vehicle gravimetry are promising.

  16. An SINS/GNSS Ground Vehicle Gravimetry Test Based on SGA-WZ02

    PubMed Central

    Yu, Ruihang; Cai, Shaokun; Wu, Meiping; Cao, Juliang; Zhang, Kaidong

    2015-01-01

    In March 2015, a ground vehicle gravimetry test was implemented in eastern Changsha to assess the repeatability and accuracy of ground vehicle SINS/GNSS gravimeter—SGA-WZ02. The gravity system developed by NUDT consisted of a Strapdown Inertial Navigation System (SINS), a Global Navigation Satellite System (GNSS) remote station on test vehicle, a GNSS static master station on the ground, and a data logging subsystem. A south-north profile of 35 km along the highway in eastern Changsha was chosen and four repeated available measure lines were obtained. The average speed of a vehicle is 40 km/h. To assess the external ground gravity disturbances, precise ground gravity data was built by CG-5 precise gravimeter as the reference. Under relative smooth conditions, internal accuracy among repeated lines shows an average agreement at the level of 1.86 mGal for half wavelengths about 1.1 km, and 1.22 mGal for 1.7 km. The root-mean-square (RMS) of difference between calculated gravity data and reference data is about 2.27 mGal/1.1 km, and 1.74 mGal/1.7 km. Not all of the noises caused by vehicle itself and experiments environments were eliminated in the primary results. By means of selecting reasonable filters and improving the GNSS observation conditions, further developments in ground vehicle gravimetry are promising. PMID:26389916

  17. Preparation and combustion of coal-water fuel from the Sin Pun coal deposit, southern Thailand

    SciTech Connect

    1997-05-01

    In response to an inquiry by the Department of Mineral Resources in Thailand, the Energy & Environmental Research Center (EERC) prepared a program to assess the responsiveness of Sin Pun lignite to the temperature and pressure conditions of hot-water drying. The results indicate that drying made several improvements in the coal, notably increases in heating value and carbon content and reductions in equilibrium moisture and oxygen content. The equilibrium moisture content decreased from 27 wt% for the raw coal to about 15 wt% for the hot-water-dried (HWD) coals. The energy density for a pumpable coal-water fuel (CWF) indicates an increase from 4500 to 6100 Btu/lb by hot-water drying. Approximately 650 lb of HWD Sin Pun CWF were fired in the EERC`s combustion test facility. The fuel burned extremely well, with no feed problems noted during the course of the test. Fouling and slagging deposits each indicated a very low rate of ash deposition, with only a dusty layer formed on the cooled metal surfaces. The combustor was operated at between 20% and 25% excess air, resulting in a flue gas SO{sub 2} concentration averaging approximately 6500 parts per million.

  18. Measurement of the CP Asymmetry Amplitude sin(2β with B0 Mesons

    NASA Astrophysics Data System (ADS)

    Aubert, B.; Boutigny, D.; Gaillard, J.-M.; Hicheur, A.; Karyotakis, Y.; Lees, J. P.; Robbe, P.; Tisserand, V.; Zghiche, A.; Palano, A.; Pompili, A.; Chen, J. C.; Qi, N. D.; Rong, G.; Wang, P.; Zhu, Y. S.; Eigen, G.; Ofte, I.; Stugu, B.; Abrams, G. S.; Borgland, A. W.; Breon, A. B.; Brown, D. N.; Button-Shafer, J.; Cahn, R. N.; Charles, E.; Gill, M. S.; Gritsan, A. V.; Groysman, Y.; Jacobsen, R. G.; Kadel, R. W.; Kadyk, J.; Kerth, L. T.; Kolomensky, Yu. G.; Kral, J. F.; Leclerc, C.; Levi, M. E.; Lynch, G.; Mir, L. M.; Oddone, P. J.; Orimoto, T. J.; Pripstein, M.; Roe, N. A.; Romosan, A.; Ronan, M. T.; Shelkov, V. G.; Telnov, A. V.; Wenzel, W. A.; Harrison, T. J.; Hawkes, C. M.; Knowles, D. J.; O'Neale, S. W.; Penny, R. C.; Watson, A. T.; Watson, N. K.; Deppermann, T.; Goetzen, K.; Koch, H.; Lewandowski, B.; Peters, K.; Schmuecker, H.; Steinke, M.; Barlow, N. R.; Bhimji, W.; Boyd, J. T.; Chevalier, N.; Clark, P. J.; Cottingham, W. N.; Mackay, C.; Wilson, F. F.; Abe, K.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; Thiessen, D.; Jolly, S.; McKemey, A. K.; Blinov, V. E.; Bukin, A. D.; Buzykaev, A. R.; Golubev, V. B.; Ivanchenko, V. N.; Korol, A. A.; Kravchenko, E. A.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Yushkov, A. N.; Best, D.; Chao, M.; Kirkby, D.; Lankford, A. J.; Mandelkern, M.; McMahon, S.; Stoker, D. P.; Buchanan, C.; Chun, S.; Hadavand, H. K.; Hill, E. J.; Macfarlane, D. B.; Paar, H.; Prell, S.; Rahatlou, Sh.; Raven, G.; Schwanke, U.; Sharma, V.; Berryhill, J. W.; Campagnari, C.; Dahmes, B.; Hart, P. A.; Kuznetsova, N.; Levy, S. L.; Long, O.; Lu, A.; Mazur, M. A.; Richman, J. D.; Verkerke, W.; Beringer, J.; Eisner, A. M.; Grothe, M.; Heusch, C. A.; Lockman, W. S.; Pulliam, T.; Schalk, T.; Schmitz, R. E.; Schumm, B. A.; Seiden, A.; Turri, M.; Walkowiak, W.; Williams, D. C.; Wilson, M. G.; Chen, E.; Dubois-Felsmann, G. P.; Dvoretskii, A.; Hitlin, D. G.; Porter, F. C.; Ryd, A.; Samuel, A.; Yang, S.; Jayatilleke, S.; Mancinelli, G.; Meadows, B. T.; Sokoloff, M. D.; Barillari, T.; Bloom, P.; Ford, W. T.; Nauenberg, U.; Olivas, A.; Rankin, P.; Roy, J.; Smith, J. G.; van Hoek, W. C.; Zhang, L.; Harton, J. L.; Hu, T.; Krishnamurthy, M.; Soffer, A.; Toki, W. H.; Wilson, R. J.; Zhang, J.; Altenburg, D.; Brandt, T.; Brose, J.; Colberg, T.; Dickopp, M.; Dubitzky, R. S.; Hauke, A.; Maly, E.; Müller-Pfefferkorn, R.; Otto, S.; Schubert, K. R.; Schwierz, R.; Spaan, B.; Wilden, L.; Bernard, D.; Bonneaud, G. R.; Brochard, F.; Cohen-Tanugi, J.; Ferrag, S.; T'jampens, S.; Thiebaux, Ch.; Vasileiadis, G.; Verderi, M.; Anjomshoaa, A.; Bernet, R.; Khan, A.; Lavin, D.; Muheim, F.; Playfer, S.; Swain, J. E.; Tinslay, J.; Falbo, M.; Borean, C.; Bozzi, C.; Piemontese, L.; Sarti, A.; Treadwell, E.; Anulli, F.; Baldini-Ferroli, R.; Calcaterra, A.; de Sangro, R.; Falciai, D.; Finocchiaro, G.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Zallo, A.; Bagnasco, S.; Buzzo, A.; Contri, R.; Crosetti, G.; Lo Vetere, M.; Macri, M.; Monge, M. R.; Passaggio, S.; Pastore, F. C.; Patrignani, C.; Robutti, E.; Santroni, A.; Tosi, S.; Bailey, S.; Morii, M.; Bartoldus, R.; Grenier, G. J.; Mallik, U.; Cochran, J.; Crawley, H. B.; Lamsa, J.; Meyer, W. T.; Rosenberg, E. I.; Yi, J.; Davier, M.; Grosdidier, G.; Höcker, A.; Lacker, H. M.; Laplace, S.; Le Diberder, F.; Lepeltier, V.; Lutz, A. M.; Petersen, T. C.; Plaszczynski, S.; Schune, M. H.; Tantot, L.; Trincaz-Duvoid, S.; Wormser, G.; Bionta, R. M.; Brigljević, V.; Lange, D. J.; van Bibber, K.; Wright, D. M.; Bevan, A. J.; Fry, J. R.; Gabathuler, E.; Gamet, R.; George, M.; Kay, M.; Payne, D. J.; Sloane, R. J.; Touramanis, C.; Aspinwall, M. L.; Bowerman, D. A.; Dauncey, P. D.; Egede, U.; Eschrich, I.; Morton, G. W.; Nash, J. A.; Sanders, P.; Smith, D.; Taylor, G. P.; Back, J. J.; Bellodi, G.; Dixon, P.; Harrison, P. F.; Potter, R. J.; Shorthouse, H. W.; Strother, P.; Vidal, P. B.; Cowan, G.; Flaecher, H. U.; George, S.; Green, M. G.; Kurup, A.; Marker, C. E.; McMahon, T. R.; Ricciardi, S.; Salvatore, F.; Vaitsas, G.; Winter, M. A.; Brown, D.; Davis, C. L.; Allison, J.; Barlow, R. J.; Forti, A. C.; Jackson, F.; Lafferty, G. D.; Lyon, A. J.; Savvas, N.; Weatherall, J. H.; Williams, J. C.; Farbin, A.; Jawahery, A.; Lillard, V.; Roberts, D. A.; Schieck, J. R.; Blaylock, G.; Dallapiccola, C.; Flood, K. T.; Hertzbach, S. S.; Kofler, R.; Koptchev, V. B.; Moore, T. B.; Staengle, H.; Willocq, S.; Brau, B.; Cowan, R.; Sciolla, G.; Taylor, F.; Yamamoto, R. K.; Milek, M.; Patel, P. M.; Palombo, F.; Bauer, J. M.; Cremaldi, L.; Eschenburg, V.; Kroeger, R.; Reidy, J.; Sanders, D. A.; Summers, D. J.; Hast, C.; Taras, P.; Nicholson, H.; Cartaro, C.; Cavallo, N.; de Nardo, G.; Fabozzi, F.; Gatto, C.; Lista, L.; Paolucci, P.; Piccolo, D.; Sciacca, C.; Losecco, J. M.; Alsmiller, J. R.; Gabriel, T. A.; Brau, J.; Frey, R.; Iwasaki, M.; Potter, C. T.; Sinev, N. B.; Strom, D.; Torrence, E.; Colecchia, F.; Dorigo, A.; Galeazzi, F.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simonetto, F.; Stroili, R.; Voci, C.; Benayoun, M.; Briand, H.; Chauveau, J.; David, P.; de La Vaissière, Ch.; del Buono, L.; Hamon, O.; Leruste, Ph.; Ocariz, J.; Pivk, M.; Roos, L.; Stark, J.; Manfredi, P. F.; Re, V.; Speziali, V.; Gladney, L.; Guo, Q. H.; Panetta, J.; Angelini, C.; Batignani, G.; Bettarini, S.; Bondioli, M.; Bucci, F.; Calderini, G.; Campagna, E.; Carpinelli, M.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Marchiori, G.; Martinez-Vidal, F.; Morganti, M.; Neri, N.; Paoloni, E.; Rama, M.; Rizzo, G.; Sandrelli, F.; Triggiani, G.; Walsh, J.; Haire, M.; Judd, D.; Paick, K.; Turnbull, L.; Wagoner, D. E.; Albert, J.; Danielson, N.; Elmer, P.; Lu, C.; Miftakov, V.; Olsen, J.; Schaffner, S. F.; Smith, A. J.; Tumanov, A.; Varnes, E. W.; Bellini, F.; Cavoto, G.; del Re, D.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Leonardi, E.; Mazzoni, M. A.; Morganti, S.; Piredda, G.; Safai Tehrani, F.; Serra, M.; Voena, C.; Christ, S.; Wagner, G.; Waldi, R.; Adye, T.; de Groot, N.; Franek, B.; Geddes, N. I.; Gopal, G. P.; Xella, S. M.; Aleksan, R.; Emery, S.; Gaidot, A.; Giraud, P.-F.; de Monchenault, G. Hamel; Kozanecki, W.; Langer, M.; London, G. W.; Mayer, B.; Schott, G.; Serfass, B.; Vasseur, G.; Yeche, Ch.; Zito, M.; Purohit, M. V.; Weidemann, A. W.; Yumiceva, F. X.; Adam, I.; Aston, D.; Berger, N.; Boyarski, A. M.; Convery, M. R.; Coupal, D. P.; Dong, D.; Dorfan, J.; Dunwoodie, W.; Field, R. C.; Glanzman, T.; Gowdy, S. J.; Grauges, E.; Haas, T.; Hadig, T.; Halyo, V.; Himel, T.; Hryn'ova, T.; Huffer, M. E.; Innes, W. R.; Jessop, C. P.; Kelsey, M. H.; Kim, P.; Kocian, M. L.; Langenegger, U.; Leith, D. W.; Luitz, S.; Luth, V.; Lynch, H. L.; Marsiske, H.; Menke, S.; Messner, R.; Muller, D. R.; O'Grady, C. P.; Ozcan, V. E.; Perazzo, A.; Perl, M.; Petrak, S.; Quinn, H.; Ratcliff, B. N.; Robertson, S. H.; Roodman, A.; Salnikov, A. A.; Schietinger, T.; Schindler, R. H.; Schwiening, J.; Simi, G.; Snyder, A.; Soha, A.; Spanier, S. M.; Stelzer, J.; Su, D.; Sullivan, M. K.; Tanaka, H. A.; Va'Vra, J.; Wagner, S. R.; Weaver, M.; Weinstein, A. J.; Wisniewski, W. J.; Wright, D. H.; Young, C. C.; Burchat, P. R.; Cheng, C. H.; Meyer, T. I.; Roat, C.; Henderson, R.; Bugg, W.; Cohn, H.; Izen, J. M.; Kitayama, I.; Lou, X. C.; Bianchi, F.; Bona, M.; Gamba, D.; Bosisio, L.; della Ricca, G.; Dittongo, S.; Lanceri, L.; Poropat, P.; Vitale, L.; Vuagnin, G.; Panvini, R. S.; Banerjee, Sw.; Brown, C. M.; Fortin, D.; Jackson, P. D.; Kowalewski, R.; Roney, J. M.; Band, H. R.; Dasu, S.; Datta, M.; Eichenbaum, A. M.; Hu, H.; Johnson, J. R.; Liu, R.; di Lodovico, F.; Mohapatra, A.; Pan, Y.; Prepost, R.; Scott, I. J.; Sekula, S. J.; von Wimmersperg-Toeller, J. H.; Wu, J.; Wu, S. L.; Yu, Z.; Neal, H.

    2002-10-01

    We present results on time-dependent CP asymmetries in neutral B decays to several CP eigenstates. The measurements use a data sample of about 88×106 ϒ(4S)-->BB¯ decays collected between 1999 and 2002 with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. We study events in which one neutral B meson is fully reconstructed in a final state containing a charmonium meson and the other B meson is determined to be either a B0 or B¯0 from its decay products. The amplitude of the CP asymmetry, which in the standard model is proportional to sin(2β, is derived from the decay-time distributions in such events. We measure sin(2β=0.741+/-0.067(stat)+/-0.034(syst) and |λ|=0.948+/-0.051(stat)+/-0.030(syst). The magnitude of λ is consistent with unity, in agreement with the standard model expectation of no direct CP violation in these modes.

  19. The two-loop electroweak bosonic corrections to sin2 ⁡ θeffb

    NASA Astrophysics Data System (ADS)

    Dubovyk, Ievgen; Freitas, Ayres; Gluza, Janusz; Riemann, Tord; Usovitsch, Johann

    2016-11-01

    The prediction of the effective electroweak mixing angle sin2 ⁡θeffb in the Standard Model at two-loop accuracy has now been completed by the first calculation of the bosonic two-loop corrections to the Z b bar b vertex. Numerical predictions are presented in the form of a fitting formula as function of MZ ,MW ,MH ,mt and Δα, αs. For central input values, we obtain a relative correction of Δκb(α2 , bos) = - 0.9855 ×10-4, amounting to about a quarter of the fermionic corrections, and corresponding to sin2 ⁡ θeffb = 0.232704. The integration of the corresponding two-loop vertex Feynman integrals with up to three dimensionless parameters in Minkowskian kinematics has been performed with two approaches: (i) Sector decomposition, implemented in the packages FIESTA 3 and SecDec 3, and (ii) Mellin-Barnes representations, implemented in AMBRE 3/MB and the new package MBnumerics.

  20. Stress engineering in GaN structures grown on Si(111) substrates by SiN masking layer application

    SciTech Connect

    Szymański, Tomasz Wośko, Mateusz; Paszkiewicz, Bogdan; Paszkiewicz, Regina

    2015-07-15

    GaN layers without and with an in-situ SiN mask were grown by using metal organic vapor phase epitaxy for three different approaches used in GaN on silicon(111) growth, and the physical and optical properties of the GaN layers were studied. For each approach applied, GaN layers of 1.4 μm total thickness were grown, using silan SiH{sub 4} as Si source in order to grow Si{sub x}N{sub x} masking layer. The optical micrographs, scanning electron microscope images, and atomic force microscope images of the grown samples revealed cracks for samples without SiN mask, and micropits, which were characteristic for the samples grown with SiN mask. In situ reflectance signal traces were studied showing a decrease of layer coalescence time and higher degree of 3D growth mode for samples with SiN masking layer. Stress measurements were conducted by two methods—by recording micro-Raman spectra and ex-situ curvature radius measurement—additionally PLs spectra were obtained revealing blueshift of PL peak positions with increasing stress. The authors have shown that a SiN mask significantly improves physical and optical properties of GaN multilayer systems reducing stress in comparison to samples grown applying the same approaches but without SiN masking layer.

  1. Blue and Fin Whale Habitat Modeling from Long-Term Year-Round Passive Acoustic Data from the Southern California Bight

    DTIC Science & Technology

    2014-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Blue and Fin Whale Habitat Modeling from Long-Term Year...predictive, year-round habitat models of the presence of calling blue and fin whales in the Southern California Bight, to facilitate Navy’s operational...calling blue and fin whales in the Southern California Bight (SCB). We will also investigate the scales over which blue and fin whales respond to their

  2. The influence of a medio-lateral unstable sole on invertor and evertor activation while descending stairs

    PubMed Central

    Yang, Ki-sik; Park, Kyungyeon; Choi, Bo-ram

    2016-01-01

    [Purpose] This study examined the effects of a medio-lateral unstable sole on invertor and evertor activation while descending stairs. [Subjects and Methods] The subjects were 30 university students with no history of ankle sprain. They descended stairs while wearing the medio-lateral unstable sole or with bare feet. Electromyography was used to record the activity of the tibialis anterior and peroneus longus and brevis muscles and paired t-tests were used to assess statistical significance. [Results] The medio-lateral unstable sole group showed increased tibialis anterior and peroneus longus and brevis muscle activation compared to the barefoot group. [Conclusion] Medio-lateral unstable sole can be used with exercises to prevent further ankle damage by activating both the inversion and eversion muscles. PMID:27630412

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

    PubMed

    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

  4. Temperature dependency of double material gate oxide (DMGO) symmetric dual-k spacer (SDS) wavy FinFET

    NASA Astrophysics Data System (ADS)

    Pradhan, K. P.; Priyanka; Sahu, P. K.

    2016-01-01

    Symmetric Dual-k Spacer (SDS) Trigate Wavy FinFET is a novel hybrid device that combines three significant and advanced technologies i.e., ultra-thin-body (UTB), FinFET, and symmetric spacer engineering on a single silicon on insulator (SOI) platform. This innovative architecture promises to enhance the device performance as compared to conventional FinFET without increasing the chip area. For the first time, we have incorporated two different dielectric materials (SiO2, and HfO2) as gate oxide to analyze the effect on various performance metrics of SDS wavy FinFET. This work evaluates the response of double material gate oxide (DMGO) on parameters like mobility, on current (Ion), transconductance (gm), transconductance generation factor (TGF), total gate capacitance (Cgg), and cutoff frequency (fT) in SDS wavy FinFET. This work also reveals the presence of biasing point i.e., zero temperature coefficient (ZTC) bias point. The ZTC bias point is that point where the device parameters become independent of temperature. The impact of operating temperature (T) on above said various performances are also subjected to extensive analysis. This further validates the reliability of DMGO-SDS FinFET and its application opportunities involved in modeling analog/RF circuits for a broad range of temperature applications. From extensive 3-D device simulation, we have determined that the inclusion of DMGO in SDS wavy FinFET is superior in performance.

  5. High-fin staggered tube banks: Heat transfer and pressure drop for turbulent single phase gas flow

    NASA Astrophysics Data System (ADS)

    1986-10-01

    This Data Item ESDU 86022 is an addition to the Heat Transfer Sub-series. New correlations are presented for external heat transfer coefficient and static pressure loss for single phase flow over plain circular fins of either retangular or tapered cross section on round tubes. The correlations were derived by a regression analysis of experimental results extracted from the literature for a wide range of tube bundle configurations. Fin densities of 4 to 11 per inch (equivalent to fin pitches of 6.4 to 2.3 mm) tube outside diameters of 3/8 to 2 inch (10 to 51 mm), fin heights of 1/4 to 5/8 inch (6 to 16 mm), and ratios of fin tip to fin root diameter of 1.2 to 2.4 were covered. For heat transfer the range of Reynolds number based on tube outer diameter was from 2,000 to 40,000 and for pressure drop from 5,000 to 50,000. Comparison of the prediction with experiment shows that for heat transfer 85% of the data points were within 10% of estimated and for pressure drop 72% were within 10%. A comprehensive worked example showing the use of the method for an air cooled heat exchanger bundle is included. The applicability of this method to nonintegral fins is considered and factors influencing the thermal resistance of the interface are discussed. Effects of fouling are also briefly covered.

  6. Static Longitudinal Stability of a Rocket Vehicle Having a Rear-Facing Step Ahead of the Stabilizing Fins

    NASA Technical Reports Server (NTRS)

    Keynton, Robert J.

    1961-01-01

    Tests were conducted at Mach numbers of 3.96 and 4.65 in the Langley Unitary Plan wind tunnel to determine the static longitudinal stability characteristics of a fin-stabilized rocket-vehicle configuration which had a rearward facing step located upstream of the fins. Two fin sizes and planforms, a delta and a clipped delta, were tested. The angle of attack was varied from 6 deg to -6 deg and the Reynolds number based on model 6 length was about 10 x 10. The configuration with the larger fins (clipped delta) had a center of pressure slightly rearward of and an initial normal-force-curve slope slightly higher than that of the configuration with the smaller fins (delta) as would be expected. Calculations of the stability parameters gave a slightly lower initial slope of the normal-force curve than measured data, probably because of boundary-layer separation ahead of the step. The calculated center of pressure agreed well with the measured data. Measured and calculated increments in the initial slope of the normal-force curve and in the center of pressure, due to changing fins, were in excellent agreement indicating that separated flow downstream of the step did not influence flow over the fins. This result was consistent with data from schlieren photographs.

  7. An exclusively mesodermal origin of fin mesenchyme demonstrates that zebrafish trunk neural crest does not generate ectomesenchyme.

    PubMed

    Lee, Raymond Teck Ho; Knapik, Ela W; Thiery, Jean Paul; Carney, Thomas J

    2013-07-01

    The neural crest is a multipotent stem cell population that arises from the dorsal aspect of the neural tube and generates both non-ectomesenchymal (melanocytes, peripheral neurons and glia) and ectomesenchymal (skeletogenic, odontogenic, cartilaginous and connective tissue) derivatives. In amniotes, only cranial neural crest generates both classes, with trunk neural crest restricted to non-ectomesenchyme. By contrast, it has been suggested that anamniotes might generate derivatives of both classes at all axial levels, with trunk neural crest generating fin osteoblasts, scale mineral-forming cells and connective tissue cells; however, this has not been fully tested. The cause and evolutionary significance of this cranial/trunk dichotomy, and its absence in anamniotes, are debated. Recent experiments have disputed the contribution of fish trunk neural crest to fin osteoblasts and scale mineral-forming cells. This prompted us to test the contribution of anamniote trunk neural crest to fin connective tissue cells. Using genetics-based lineage tracing in zebrafish, we find that these fin mesenchyme cells derive entirely from the mesoderm and that neural crest makes no contribution. Furthermore, contrary to previous suggestions, larval fin mesenchyme cells do not generate the skeletogenic cells of the adult fin, but persist to form fibroblasts associated with adult fin rays. Our data demonstrate that zebrafish trunk neural crest does not generate ectomesenchymal derivatives and challenge long-held ideas about trunk neural crest fate. These findings have important implications for the ontogeny and evolution of the neural crest.

  8. Thermocouple Positioning For The Application Of The Non-Integer System Identification Approach To HIFIRE-5 Fins

    NASA Astrophysics Data System (ADS)

    Lohle, Stefan; Bohrk, Hannah; Fuchs, Ulf

    2011-05-01

    The German Aerospace Center developed a ceramic fin experiment (FinEx) for HIFiRE-5 flight in order to test the performance of new structure designs during hyper- sonic flight. Aero-thermal analysis is provided by 8 thermocouple data channels for all four symmetrically arranged fins. In this paper the analysis of the geometry and thermophysical characteristics of the fins to optimize thermocouple positioning is discussed. The main goal is to gather as much information as possible from these few temperature sensors in these three dimensional structures. Not only is the absolute temperature value of interest but also the reason of the temperature rise. A thorough calculation of the temperature gradients in the fin structure is used to define an optimal positioning layout, where particular focus lies on the localization of the heat fluxes at the surface from the in-depth thermocouple measurement. In conclusion, two fins are equipped with 3 thermocouples each and two are equipped with only 1 thermocouple. The paper closes with some first results based on the calibration data of the fins and the nominal trajectory values.

  9. Two methods of tuning threshold voltage of bulk FinFETs with replacement high-k metal-gate stacks

    NASA Astrophysics Data System (ADS)

    Xu, Miao; Zhu, Huilong; Zhang, Yanbo; Xu, Qiuxia; Zhang, Yongkui; Qin, Changliang; Zhang, Qingzhu; Yin, Huaxiang; Xu, Hao; Chen, Shuai; Luo, Jun; Li, Chunlong; Zhao, Chao; Ye, Tianchun

    2017-03-01

    In this work, we propose two threshold voltage (VTH) tuning methods for bulk FinFETs with replacement high-k metal gate. The first method is to perform a vertical implantation into fin structure after dummy gate removal, self-aligned forming halo & punch through stop pocket (halo & PTSP) doping profile. The second method is to execute P+/BF2+ ion implantations into the single common work function (WF) layer in N-/P-FinFETs, respectively. These two methods have been investigated by TCAD simulations and MOS-capacitor experiments respectively, and then integrated into FinFET fabrication successfully. Experimental results show that the halo & PTSP doping profile can reduce VTH roll off and total variation. With P+/BF2+ doped WF layer, the VTH-sat shift -0.43 V/+1.26 V for N-FinFETs and -0.75 V/+0.11 V for P-FinFETs, respectively, with gate length of 500 nm. The proposed two methods are simple and effective for FinFET VTH tuning, and have potential for future application of massive production.

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

    PubMed

    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.

  11. Constraints on starting and stopping: behavior compensates for reduced pectoral fin area during braking of the bluegill sunfish Lepomis macrochirus.

    PubMed

    Higham, Timothy E; Malas, Brett; Jayne, Bruce C; Lauder, George V

    2005-12-01

    Many natural animal movements involve accelerating from a standstill and then stopping. Obstacles in natural environments often limit the straight-line distance available for movement, and decreased braking ability theoretically can limit speed for short distances. Consequently, braking ability can be important for avoiding collisions with obstacles and exploiting resources effectively in complex environments. A presumed morphological correlate of improved braking performance in fish is increased pectoral fin area, because most fish protract these structures as they decelerate. However, the kinematics and modulation of velocity during starting and stopping are poorly understood for most species of fish as well as most species of animals. Thus, for bluegill sunfish Lepomis macrochirus with complete and partially ablated pectoral fins (35% original fin area), we analyzed high speed video recordings (200 images s-1) of predatory attacks with a start and stop in a short, standardized distance (40 cm). We quantified body displacement, velocity, acceleration, deceleration and several fin angle variables during each feeding. Unexpectedly, several variables including maximum velocity and maximum deceleration (grand means 72 cm s-1 and -512 cm s-2, respectively) did not change significantly with reduced pectoral fin area. The average values of braking movements of the median and caudal fins did increase with decreased pectoral fin area but lacked statistically significant differences. The primary mechanism of attaining similar braking performance with decreased area of the pectoral fins was that they were protracted significantly more (mean difference=42 degrees) and with a significantly faster average velocity of protraction. Thus, pectoral fin area appears unlikely to be the primary constraint on braking performance for this particular task.

  12. Advances in Understanding the Role of Aerosols on Ice Clouds from the Fifth International Ice Nucleation (FIN) Workshops

    NASA Astrophysics Data System (ADS)

    Cziczo, D. J.; Moehler, O.; DeMott, P. J.

    2015-12-01

    The relationship of ambient aerosol particles to the formation of ice-containing clouds is one of the largest uncertainties in understanding climate. This is due to several poorly understood processes including the microphysics of how particles nucleate ice, the number of effective heterogeneous ice nuclei and their atmospheric distribution, the role of anthropogenic activities in producing or changing the behavior of ice forming particles and the interplay between effective heterogeneous ice nuclei and homogeneous ice formation. Our team recently completed a three-part international workshop to improve our understanding of atmospheric ice formation. Termed the Fifth International Ice Nucleation (FIN) Workshops, our motivation was the limited number of measurements and a lack of understanding of how to compare data acquired by different groups. The first activity, termed FIN1, addressed the characterization of ice nucleating particle size, number and chemical composition. FIN2 addressed the determination of ice nucleating particle number density. Groups modeling ice nucleation joined FIN2 to provide insight on measurements critically needed to model atmospheric ice nucleation and to understand the performance of ice chambers. FIN1 and FIN2 took place at the Aerosol Interaction and Dynamics in the Atmosphere (AIDA) chamber at the Karlsruhe Institute of Technology. A particular emphasis of FIN1 and FIN2 was the use of 'blind' intercomparisons using a highly characterized, but unknown to the instrument operators, aerosol sample. The third activity, FIN3, took place at the Desert Research Institute's Storm Peak Laboratory (SPL). A high elevation site not subject to local emissions, SPL allowed for a comparison of ice chambers and subsequent analysis of the ice residuals under the challenging conditions of low particle loading, temperature and pressure found in the atmosphere. The presentation focuses on the improvement in understanding how mass spectra from different

  13. Developmental change in the function of movement systems: transition of the pectoral fins between respiratory and locomotor roles in zebrafish.

    PubMed

    Hale, Melina E

    2014-07-01

    An animal may experience strikingly different functional demands on its body's systems through development. One way of meeting those demands is with temporary, stage-specific adaptations. This strategy requires the animal to develop appropriate morphological states or physiological pathways that address transient functional demands as well as processes that transition morphology, physiology, and function to that of the mature form. Recent research on ray-finned (actinopterygian) fishes is a developmental transition in function of the pectoral fin, thereby providing an opportunity to examine how an organism copes with changes in the roles of its morphology between stages of its life history. As larvae, zebrafish alternate their pectoral fins in coordination with the body axis during slow swimming. The movements of their fins do not appear to contribute to the production of thrust or to stability but instead exchange fluid near the body for cutaneous respiration. The morphology of the larval fin includes a simple stage-specific endoskeletal disc overlaid by fan-shaped adductor and abductor muscles. In contrast, the musculoskeletal system of the mature fin consists of a suite of muscles and bones. Fins are extended laterally during slow swimming of the adult, without the distinct, high-amplitude left-right fin alternation of the larval fin. The morphological and functional transition of the pectoral fin occurs through juvenile development. Early in this period, at about 3 weeks post-fertilization, the gills take over respiratory function, presumably freeing the fins for other roles. Kinematic data suggest that the loss of respiratory function does not lead to a rapid switch in patterns of fin movement but rather that both morphology and movement transition gradually through the juvenile stage of development. Studies relating structure to function often focus on stable systems that are arguably well adapted for the roles they play. Examining how animals navigate

  14. Developmental Change in the Function of Movement Systems: Transition of the Pectoral Fins between Respiratory and Locomotor Roles in Zebrafish

    PubMed Central

    Hale, Melina E.

    2014-01-01

    An animal may experience strikingly different functional demands on its body’s systems through development. One way of meeting those demands is with temporary, stage-specific adaptations. This strategy requires the animal to develop appropriate morphological states or physiological pathways that address transient functional demands as well as processes that transition morphology, physiology, and function to that of the mature form. Recent research on ray-finned (actinopterygian) fishes is a developmental transition in function of the pectoral fin, thereby providing an opportunity to examine how an organism copes with changes in the roles of its morphology between stages of its life history. As larvae, zebrafish alternate their pectoral fins in coordination with the body axis during slow swimming. The movements of their fins do not appear to contribute to the production of thrust or to stability but instead exchange fluid near the body for cutaneous respiration. The morphology of the larval fin includes a simple stage-specific endoskeletal disc overlaid by fan-shaped adductor and abductor muscles. In contrast, the musculoskeletal system of the mature fin consists of a suite of muscles and bones. Fins are extended laterally during slow swimming of the adult, without the distinct, high-amplitude left-right fin alternation of the larval fin. The morphological and functional transition of the pectoral fin occurs through juvenile development. Early in this period, at about 3 weeks post-fertilization, the gills take over respiratory function, presumably freeing the fins for other roles. Kinematic data suggest that the loss of respiratory function does not lead to a rapid switch in patterns of fin movement but rather that both morphology and movement transition gradually through the juvenile stage of development. Studies relating structure to function often focus on stable systems that are arguably well adapted for the roles they play. Examining how animals navigate

  15. Three-dimensional Finite Elements Method simulation of Total Ionizing Dose in 22 nm bulk nFinFETs

    NASA Astrophysics Data System (ADS)

    Chatzikyriakou, Eleni; Potter, Kenneth; Redman-White, William; De Groot, C. H.

    2017-02-01

    Finite Elements Method simulation of Total Ionizing Dose effects on 22 nm bulk Fin Field Effect Transistor (FinFET) devices using the commercial software Synopsys Sentaurus TCAD is presented. The simulation parameters are extracted by calibrating the charge trapping model to experimental results on 400 nm SiO2 capacitors irradiated under zero bias. The FinFET device characteristics are calibrated to the Intel 22 nm bulk technology. Irradiation simulations of the transistor performed with all terminals unbiased reveal increased hardness up to a total dose of 1 MRad(SiO2).

  16. The chemokine SDF-1 regulates blastema formation during zebrafish fin regeneration.

    PubMed

    Dufourcq, Pascale; Vriz, Sophie

    2006-10-01

    The work presented in this study focuses on blastema formation in epimorphic regeneration. We describe the expression pattern of Sdf1a and Sdf1b (the chemokines stromal-cell-derived factor-1a and 1b) and their two receptors Cxcr4a and Cxcr4b during zebrafish fin regeneration. We demonstrate that Sdf1a/Cxcr4a plays a critical role in fin regeneration and more precisely in epidermal cell proliferation, an important process for blastema formation. In mammals, a single cxcr4 gene is involved both in chemotaxis and cell proliferation and survival; we discuss in this study a possible functional division of the two cxcr4 zebrafish genes.

  17. High temperature study of flexible silicon-on-insulator fin field-effect transistors

    SciTech Connect

    Diab, Amer; Torres Sevilla, Galo A.; Ghoneim, Mohamed T.; Hussain, Muhammad M.

    2014-09-29

    We report high temperature electrical transport characteristics of a flexible version of the semiconductor industry's most advanced architecture: fin field-effect transistor on silicon-on-insulator with sub-20 nm fins and high-κ/metal gate stacks. Characterization from room to high temperature (150 °C) was completed to determine temperature dependence of drain current (I{sub ds}), gate leakage current (I{sub gs}), transconductance (g{sub m}), and extracted low-field mobility (μ{sub 0}). Mobility degradation with temperature is mainly caused by phonon scattering. The other device characteristics show insignificant difference at high temperature which proves the suitability of inorganic flexible electronics with advanced device architecture.

  18. Numerical and experimental investigations of transient behaviour of compact plate fin heat exchanger

    NASA Astrophysics Data System (ADS)

    Chakravarty, Abhilash; Goyal, M.; Chakravarty, A.; Joemon, V.

    2017-02-01

    In this paper, models for the transient simulation of a 2 stream plate fin heat exchanger (PFHE) with offset strip fins (OSF) have been formulated based on unsteady mass and energy conservation equations. The behaviour of a PFHE during start up, cool down and during a ramp change in the inlet temperature of one of the fluids have been studied with the help of these models. Initially, a simplified model considering constant helium properties is developed. This model is further evolved to take into account the temperature dependence of helium properties in the cryogenic temperature domain, along with axial heat conduction (AHC) and thermal capacity of the metal separating plate. Computer codes based on the models have been developed to simulate PFHE behaviour. Experiments at room temperature have been carried out for code validation. It has been found that the model based on constant helium properties is sufficient to predict behaviour of the heat exchanger under room temperature conditions.

  19. The Practical Calculation of the Aerodynamic Characteristics of Slender Finned Vehicles

    NASA Technical Reports Server (NTRS)

    Barrowman, James S.

    1967-01-01

    The basic objective of this thesis is to provide a practical method of computing the aerodynamic characteristics of slender finned vehicles such as sounding rockets, high speed bombs, and guided missiles. The aerodynamic characteristics considered are the normal force coefficient derivative, c(sub N(sub alpha)); center of pressure, bar-X; roll forcing moment coefficient derivative, c(sub l(sub delta)); roll damping moment coefficient derivative, c(sub l(sub p)); pitch damping moment coefficient derivative, c(sub mq); and the drag coefficient, c (sub D). Equations are determined for both subsonic and supersonic flow. No attempts is made to analyze the transonic region. The general configuration to which the relations are applicable is a slender axisymmetric body having three or four fins.

  20. Caudal fin in the white shark, Carcharodon carcharias (Lamnidae): a dynamic propeller for fast, efficient swimming.

    PubMed

    Lingham-Soliar, Theagarten

    2005-05-01

    The caudal peduncle and caudal fin of Carcharodon carcharias together form a dynamic locomotory structure. The caudal peduncle is a highly modified, dorsoventrally compressed and rigid structure that facilitates the oscillations of the caudal fin. Its stiffness appears to be principally achieved by a thick layer of adipose tissue ranging from 28-37% of its cross-sectional area, reinforced by cross-woven collagen fibers. Numerous overlying layers of collagen fibers of the stratum compactum, oriented in steep left- and right-handed helices (approximately 65 degrees to the shark's long axis), prevent bowstringing of the perimysial fibers, which lie just below the dermal layer. Perimysial fibers, muscles, and the notochord are restricted to the dorsal lobe of the caudal fin and comprise the bulk of its mass. Adipose tissue reinforces the leading edge of the dorsal lobe of the caudal fin and contributes to maintaining the ideal cross-sectional geometry required of an advanced hydrofoil. Most of the mass of the ventral lobe consists of the ceratotrichia or fin rays separated by thin partitions of connective tissue. Dermal fibers of the stratum compactum of the dorsal lobe occur in numerous distinct layers. The layers are more complex than in other sharks and appear to reflect a hierarchical development in C. carcharias. The fiber layer comprises a number of thick fiber bundles along the height of the layer and the layers get thicker deeper into the stratum compactum. Each of these layers alternates with a layer a single fiber-bundle deep, a formation thought to give stability to the stratum compactum and to enable freer movements of the fiber system. In tangential sections of the stratum compactum the fiber bundles in the dorsal lobe can be seen oriented with respect to the long axis of the shark at approximately 55-60 degrees in left- and right-handed helices. Because of the backward sweep of the dorsal lobe (approximately 55 degrees to the shark's long axis) the right