WorldWideScience

Sample records for higher ed fin

  1. Mitigating Higher Ed Cyber Attacks

    Science.gov (United States)

    Rogers, Gary; Ashford, Tina

    2015-01-01

    In this presentation we will discuss the many and varied cyber attacks that have recently occurred in the higher ed community. We will discuss the perpetrators, the victims, the impact and how these institutions have evolved to meet this threat. Mitigation techniques and defense strategies will be covered as will a discussion of effective security…

  2. HigherEd 2.0: Using social media in engineering education

    OpenAIRE

    Berger, Edward

    2014-01-01

    Social media (blogs, wikis, video, and a digital authoring culture) has emerged in the last decade as a dominant feature of the technology landscape, especially for our current generation of digital-native students. Leveraging these tools for higher education in general, and engineering education in particular, should be of immediate and pressing concern for engineering educators. This discussion summarizes the HigherEd 2.0 project, the creative convergence of higher education and “web 2.0” t...

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

    DEFF Research Database (Denmark)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2018-05-01

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

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

    Science.gov (United States)

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

    2014-10-15

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

  6. FinFET memory cell improvements for higher immunity against single event upsets

    Science.gov (United States)

    Sajit, Ahmed Sattar

    The 21st century is witnessing a tremendous demand for transistors. Life amenities have incorporated the transistor in every aspect of daily life, ranging from toys to rocket science. Day by day, scaling down the transistor is becoming an imperious necessity. However, it is not a straightforward process; instead, it faces overwhelming challenges. Due to these scaling changes, new technologies, such as FinFETs for example, have emerged as alternatives to the conventional bulk-CMOS technology. FinFET has more control over the channel, therefore, leakage current is reduced. FinFET could bridge the gap between silicon devices and non-silicon devices. The semiconductor industry is now incorporating FinFETs in systems and subsystems. For example, Intel has been using them in their newest processors, delivering potential saving powers and increased speeds to memory circuits. Memory sub-systems are considered a vital component in the digital era. In memory, few rows are read or written at a time, while the most rows are static; hence, reducing leakage current increases the performance. However, as a transistor shrinks, it becomes more vulnerable to the effects from radioactive particle strikes. If a particle hits a node in a memory cell, the content might flip; consequently, leading to corrupting stored data. Critical fields, such as medical and aerospace, where there are no second chances and cannot even afford to operate at 99.99% accuracy, has induced me to find a rigid circuit in a radiated working environment. This research focuses on a wide spectrum of memories such as 6T SRAM, 8T SRAM, and DICE memory cells using FinFET technology and finding the best platform in terms of Read and Write delay, susceptibility level of SNM, RSNM, leakage current, energy consumption, and Single Event Upsets (SEUs). This research has shown that the SEU tolerance that 6T and 8T FinFET SRAMs provide may not be acceptable in medical and aerospace applications where there is a very high

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

    Science.gov (United States)

    Kirk, Benjamin S.

    2010-01-01

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

  8. EscapED: A Framework for Creating Educational Escape Rooms and Interactive Games to For Higher/Further Education.

    Directory of Open Access Journals (Sweden)

    Samantha Jane Clarke

    2017-09-01

    Full Text Available Game-based learning (GBL is often found to be technologically driven and more often than not, serious games for instance, are conceptualised and designed solely for digital platforms and state of the art technologies. To encourage a greater discussion on the potential benefits and challenges of a more holistic approach to developing GBL that promote human centered interactions and play for learning, the authors present the escapED programme. The escapED programme was conceived following the recent entertainment trend of escape rooms and is used for developing non-digital GBL approaches within education. escapED aids the design and creation of educational Escape Rooms and Interactive Gaming Experiences for staff and students in further/higher education settings. The paper first presents a pilot study that was used to assess the feasibility and acceptance of University teaching staff of embedding interactive GBL into a higher education environment. The authors then present the escapED theoretical framework that was used to create the prototype game for the pilot study as a tool to aid future design and development of on-site interactive experiences. The paper also presents an external developer report of using the escapED framework to develop a prototype game for teaching research methods to Southampton University students. Finally, the authors present a discussion on the use of the escapED framework so far and plans for future work and evaluation in order to provide engaging alternatives for learning and soft skills development amongst higher education staff andstudents.

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

    Science.gov (United States)

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

    2018-03-01

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

  10. Effects of fin shape on condensation in herringbone microfin tubes

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-06-01

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

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

    International Nuclear Information System (INIS)

    Kim, Nae Hyun; Kim, Tae Hun

    2015-01-01

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

  12. Quality assurance in transnational higher education: a case study of the tropEd network.

    Science.gov (United States)

    Zwanikken, Prisca A C; Peterhans, Bernadette; Dardis, Lorraine; Scherpbier, Albert

    2013-03-27

    Transnational or cross-border higher education has rapidly expanded since the 1980s. Together with that expansion issues on quality assurance came to the forefront. This article aims to identify key issues regarding quality assurance of transnational higher education and discusses the quality assurance of the tropEd Network for International Health in Higher Education in relation to these key issues. Literature review and review of documents. From the literature the following key issues regarding transnational quality assurance were identified and explored: comparability of quality assurance frameworks, true collaboration versus erosion of national education sovereignty, accreditation agencies and transparency. The tropEd network developed a transnational quality assurance framework for the network. The network accredits modules through a rigorous process which has been accepted by major stakeholders. This process was a participatory learning process and at the same time the process worked positive for the relations between the institutions. The development of the quality assurance framework and the process provides a potential example for others.

  13. Channels with Different Fin Shapes

    Directory of Open Access Journals (Sweden)

    R. J. Goldstein

    1998-01-01

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

  14. Fin Ray Stiffness and Fin Morphology Control Ribbon-Fin-Based Propulsion.

    Science.gov (United States)

    Liu, Hanlin; Taylor, Bevan; Curet, Oscar M

    2017-06-01

    Ribbon-fin-based propulsion has rich locomotor capabilities that can enhance the mobility and performance of underwater vehicles navigating in complex environments. Bony fishes using this type of propulsion send one or multiple traveling waves along an elongated fin with the actuation of highly flexible rays that are interconnected by an elastic membrane. In this work, we study how the use of flexible rays and different morphology can affect the performance of ribbon-fin propulsion. We developed a physical model composed of 15 rays that are interconnected with an elastic membrane. We tested four different ray flexural stiffness and four aspect ratios. The robotic model was tested in a low-turbulence flume under two flow conditions ([Formula: see text] wavelength/s). In two experimental sets, we measured fin kinematics, net surge forces, and power consumption. Using these data, we perform a thrust and power analysis of the undulating fin. We present the thrust coefficient, power coefficient, and propulsive efficiency. We find that the thrust generation was linear with the enclosed area swept by the fin, and square of the relative velocity between the incoming flow and traveling wave. The thrust coefficient levels off around 0.5. In addition, for our parameter range, we find that the power consumption scales by the cube of the effective tangential velocity of the rays [Formula: see text] (A is the amplitude of the ray oscillating motion, and [Formula: see text] is the angular velocity). We show that a decay in stiffness decreases both thrust production and power consumption. However, for rays with high flexural stiffness, the difference in thrust compared with rigid rays is minimal. Moreover, our results show that flexible rays can improve the propulsive efficiency compared with a rigid counterpart. Finally, we find that the morphology of ribbon fin affects its propulsive efficiency. For the aspect ratio considered in our experiments, [Formula: see text] was the most

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

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  16. Role of Pectoral Fin Flexibility in Robotic Fish Performance

    Science.gov (United States)

    Bazaz Behbahani, Sanaz; Tan, Xiaobo

    2017-08-01

    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.

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

    Science.gov (United States)

    Ahn, Joonsung; Kim, Tae Whan

    2018-03-01

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

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

    Directory of Open Access Journals (Sweden)

    Zheng Hui-Fan

    2013-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Lagutin A. E.

    2016-12-01

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

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

    International Nuclear Information System (INIS)

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

    2007-01-01

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

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

    International Nuclear Information System (INIS)

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

    2010-01-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Phelan, Chris; Tangorra, James [Department of Mechanical Engineering, Drexel University, Philadelphia, PA 19104 (United States); Lauder, George [Museum of Comparative Zoology, Harvard University, Cambridge, MA 02138 (United States); Hale, Melina, E-mail: tangorra@coe.drexel.ed [Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL 60637 (United States)

    2010-09-15

    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.

  3. 50 CFR 600.1204 - Shark finning; possession at sea and landing of shark fins.

    Science.gov (United States)

    2010-10-01

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

  4. Effect of storage media and time on fin explants culture in the ...

    African Journals Online (AJOL)

    The effect of storage media and time was investigated on fin explants culture in the goldfish (Carassius auratus). Fin explants under sterile conditions were able to produce cells at different storage media and time. On the outgrowth of cells, fin explants stored for seven days before culturing showed significantly higher growth ...

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

    International Nuclear Information System (INIS)

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

    2002-01-01

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

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

    International Nuclear Information System (INIS)

    Shyu, Jin-Cherng; Syu, Jhih-Zong

    2014-01-01

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

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

    Science.gov (United States)

    Binning, Sandra A; Roche, Dominique G

    2015-03-01

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

  8. 3D modeling of dual-gate FinFET.

    Science.gov (United States)

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

    2012-11-13

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

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

    OpenAIRE

    Omreng, Stian; Gjendem, Ida

    2017-01-01

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

  10. The impact of internal longitudinal fins in parabolic trough collectors operating with gases

    International Nuclear Information System (INIS)

    Bellos, Evangelos; Tzivanidis, Christos; Daniil, Ilias; Antonopoulos, Kimon A.

    2017-01-01

    Highlights: • In this study, the impact of internal fins in PTC operating with gases is presented. • Air, helium and CO_2 are tested in smooth absorber and with fins of 5–10 mm and 15 mm. • Greater fin length leads to higher thermal efficiency and 10 mm is the optimum length exergetically. • Helium is the best working fluid exergetically, with CO_2 and air to follow. • Up to 290 °C, helium performs better energetically, while CO_2 in higher temperatures. - Abstract: In this study, the use of internal fins in parabolic trough collectors operating with gas working fluids is examined. Air, helium and carbon dioxide are the investigated working fluids, while Eurotrough ET-150 is the examined solar collector. The design and the simulation of this solar collector are performed with the commercial software Solidworks Flow Simulation. The internal fins lead to higher thermal efficiency but also to higher pressure losses; something very important for the solar fields of Concentrated Power Plants. Thus, the collector is examined energetically and exergetically in order to take into account the increase in the useful output with the simultaneous greater need of pumping power. Various fin lengths are examined and finally the fin of 10 mm was proved to be the most appropriate exergetically. In working fluid comparison, helium is the most efficient working fluid exergetically for all the examined cases. In the thermal efficiency comparison, helium performs better up to 290 °C, while carbon dioxide is the best choice in higher temperature levels. Moreover, the optimum mass flow rate for the helium was proved to be 0.03 kg/s and for the other working fluids the value of 0.015 kg/s seems to lead to the most satisfying results.

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

    OpenAIRE

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

    1998-01-01

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

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

    OpenAIRE

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

    2015-01-01

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

  13. A Comparative Study of Conventional and Tip-Fin Propeller Performance

    DEFF Research Database (Denmark)

    Andersen, Poul

    1997-01-01

    During more than a decade several attempts have been made to obtain higher propeller efficiencies by radically modifying the geometry in the tip region of the blade. In the tip-fin propeller a tip fin or winglet is attached to the blade tip and integrated into the blade in such a way that the bla...

  14. Influence of the degree of thermal contact in fin and tube heat exchanger

    DEFF Research Database (Denmark)

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

    2016-01-01

    Present work aims to investigate the significance of thermal contact area between fins and tubes in a heat exchanger. The heat exchanger type selected for the study is a liquid-gas fin and tube heat exchanger. Four different cases namely I, II, III, and IV, based on a variable degree of thermal...... contact between fins and tubes are investigated. Case-I with 100% thermal contact area between the fin and tube is set as a reference to cases-II, III, and IV with a thermal contact area of approximately 70%, 50%, and 35%, respectively. Three-dimensional (3D) steady-state numerical models based on finite...... and to compare the performance of heat exchanger design in different cases. Comparative analysis indicates a significant influence of the degree of the thermal contact area between fin and tube on the overall performance. Case-I is found to have higher overall heat transfer coefficient of 47.332 W/(m2 K), higher...

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

    DEFF Research Database (Denmark)

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

    2017-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Ahmad Zaini

    2013-09-01

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

  17. Toward quantum FinFET

    CERN Document Server

    Wang, Zhiming

    2013-01-01

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

  18. PHASE CHANGE AROUND A FINNED TUBE

    Directory of Open Access Journals (Sweden)

    Aytunç EREK

    2003-01-01

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

  19. Experimental study on heat transfer performance of fin-tube exchanger and PSHE for waste heat recovery

    Science.gov (United States)

    Chen, Ting; Bae, Kyung Jin; Kwon, Oh Kyung

    2018-02-01

    In this paper, heat transfer characteristics of fin-tube heat exchanger and primary surface heat exchanger (PSHE) used in waste heat recovery were investigated experimentally. The flow in the fin-tube heat exchanger is cross flow and in PSHE counter flow. The variations of friction factor and Colburn j factor with air mass flow rate, and Nu number with Re number are presented. Various comparison methods are used to evaluate heat transfer performance, and the results show that the heat transfer rate of the PSHE is on average 17.3% larger than that of fin-tube heat exchanger when air mass flow rate is ranging from 1.24 to 3.45 kg/min. However, the PSHE causes higher pressure drop, and the fin-tube heat exchanger has a wider application range which leads to a 31.7% higher value of maximum heat transfer rate compared to that of the PSHE. Besides, under the same fan power per unit frontal surface, a higher heat transfer rate value is given in the fin-tube heat exchanger.

  20. The ED use and non-urgent visits of elderly patients.

    Science.gov (United States)

    Gulacti, Umut; Lok, Ugur; Celik, Murat; Aktas, Nurettin; Polat, Haci

    2016-12-01

    To evaluate the use of the emergency department (ED) by elderly patients, their non-urgent visits and the prevalence of main disease for ED visits. This cross-sectional study was conducted on patients aged 65 years and over who visited the ED of a tertiary care university hospital in Turkey between January 2015 and January 2016 retrospectively. A total of 36,369 elderly patients who visited the ED were included in the study. The rate of ED visits by elderly patients was higher than their representation within the general population (p elderly patients visiting polyclinics was 15.8%, the rate of elderly patients visiting the ED was 24.3% (p elderly age groups (p elderly population (17.5%, CI: 17.1-17.9). The proportion of ED visits for non-urgent conditions was 23.4%. Most of the ED visits were during the non-business hours (51.1%), and they were highest in the winter season (25.9%) and in January (10.2%). The hospitalization rate was 9.4%, and 37.9% of hospitalized patients were admitted to intensive care units. The proportion of ED visits by elderly patients was higher than their representation within the general population. Elderly patients often visited the ED instead of a polyclinic. The rate of inappropriate ED use by elderly patients in this hospital was higher than in other countries.

  1. Numerical analysis of steady state and transient analysis of high temperature ceramic plate-fin heat exchanger

    International Nuclear Information System (INIS)

    Nagarajan, Vijaisri; Chen, Yitung; Wang, Qiuwang; Ma, Ting

    2014-01-01

    Highlights: • Rip saw fin design is considered to be the best because it has thin fins and has higher heat transfer coefficient. • Minimum principal stress and maximum safety factor are obtained for the inverted bolt fin design. • Maximum principal stress and minimum safety factor are obtained for triangular fin design. • Thermal stress has significant impact than mechanical stress. • High principal stress is found at the startup and shutdown stage. - Abstract: In this study three-dimensional model of ceramic plate-fin high temperature heat exchanger with different fin designs and arrangements is analyzed numerically using ANSYS FLUENT and ANSYS structural module. The ability of ceramics to withstand high temperature and corrosion makes silicon carbide (SiC) suitable candidate material to be used in high temperature heat exchanger. The operating temperature of heat exchanger is 950 °C and the operating pressure is 1.5 MPa. The working fluids are helium, sulfur trioxide, sulfur dioxide, oxygen and the water vapor. Fluid flow and heat transfer analysis are carried out for steady and transient state in FLUENT. The obtained thermal and pressure load for the steady and transient state from ANSYS FLUENT are imported to ANSYS structural module to obtain the principal stress and the factor of safety. Different arrangements of rectangular fins, triangular fins, inverted bolt fins and ripsaw fins are studied. From the results it is found that the minimum stress and the maximum safety factor are obtained for inverted bolt fins. The triangular fins have the maximum principal stress and minimum factor of safety. However, the fluid flow and heat transfer analysis show inverted bolt fins and triangular fins produce higher pressure drop and friction factor. The steady state maximum principal stress is 10.08 MPa, 9.90 MPa and 11.43 MPa for straight, staggered and top and bottom ripsaw fin arrangement. The corresponding safety factors are 21.80, 21.95 and 19

  2. Experimental research on single phase convection heat transfer in micro-fin tube

    International Nuclear Information System (INIS)

    Fan Guangming; Sun Zhongning; Zhu Sheng

    2011-01-01

    An experimental investigation of heat transfer and flow resistance characteristics of single phase water in three micro-fin tubes with different fin height was conducted. At the same time, the efficiency of micro-fin tubes within the experimental scope was evaluated and the optimal working region was determined. Based on the experimental data in the optimal working region, correlations for predicting the heat transfer and flow resistance were also given by multiple regression method. The result indicates that the micro-fin tubes can greatly enhance the single-phase heat transfer in turbulent flow, and the increase of heat transfer coefficient is higher than the increase of flow resistance. The accuracy of the correlation is very high, of which the deviation from the experimental value is very small. (authors)

  3. The ED use and non-urgent visits of elderly patients

    Directory of Open Access Journals (Sweden)

    Umut Gulacti

    2016-12-01

    Full Text Available Objective: To evaluate the use of the emergency department (ED by elderly patients, their non-urgent visits and the prevalence of main disease for ED visits. Methods: This cross-sectional study was conducted on patients aged 65 years and over who visited the ED of a tertiary care university hospital in Turkey between January 2015 and January 2016 retrospectively. Results: A total of 36,369 elderly patients who visited the ED were included in the study. The rate of ED visits by elderly patients was higher than their representation within the general population (p < 0.001. While the rate of elderly patients visiting polyclinics was 15.8%, the rate of elderly patients visiting the ED was 24.3% (p < 0.001. For both genders, the rates of ED visits for patients between 65 and 74 years old was higher than for other elderly age groups (p < 0.001. The prevalence of upper respiratory tract infection (URTI was the highest within the elderly population (17.5%, CI: 17.1–17.9. The proportion of ED visits for non-urgent conditions was 23.4%. Most of the ED visits were during the non-business hours (51.1%, and they were highest in the winter season (25.9% and in January (10.2%. The hospitalization rate was 9.4%, and 37.9% of hospitalized patients were admitted to intensive care units. Conclusion: The proportion of ED visits by elderly patients was higher than their representation within the general population. Elderly patients often visited the ED instead of a polyclinic. The rate of inappropriate ED use by elderly patients in this hospital was higher than in other countries. Keywords: Non-urgent, Prevalence, Visit, Main disease, Elderly patient, Emergency department

  4. Advanced microchannel heat exchanger with S-shaped fins

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  5. Fin shape thermal optimization using Bejan's constuctal theory

    CERN Document Server

    Lorenzini, Giulio

    2011-01-01

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

  6. Experimental Validation of Elliptical Fin-Opening Behavior

    Directory of Open Access Journals (Sweden)

    James M. Garner

    2003-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Kadhum Audaa Jehhef

    2018-04-01

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

  8. 从FinTech到RegTech

    Institute of Scientific and Technical Information of China (English)

    孙国峰[1,2

    2017-01-01

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

  9. Thermal transport in oblique finned microminichannels

    CERN Document Server

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

    2015-01-01

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

  10. UOP FIN 571 Final Exam Guide New

    OpenAIRE

    ADMIN

    2018-01-01

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

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

    Science.gov (United States)

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

    2017-11-01

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

  12. Study on finned pipe performance as a ground heat exchanger

    Science.gov (United States)

    Lin, Qinglong; Ma, Jinghui; Shi, Lei

    2017-08-01

    The GHEs (ground heat exchangers) is an important element that determines the thermal efficiency of the entire ground-source heat-pump system. The aim of the present study is to clarify thermal performance of a new type GHE pipe, which consists straight fins of uniform cross sectional area. In this paper, GHE model is introduced and an analytical model of new type GHE pipe is developed. The heat exchange rate of BHEs utilizing finned pips is 40.42 W/m, which is 16.3% higher than normal BHEs, based on simulation analyses.

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

    Science.gov (United States)

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

    2017-11-01

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

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

    Science.gov (United States)

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

    1995-02-01

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

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  16. Analytical solution to convection-radiation of a continuously moving fin with temperature-dependent thermal conductivity

    Directory of Open Access Journals (Sweden)

    Moradi Amir

    2013-01-01

    Full Text Available In this article, the simultaneous convection-radiation heat transfer of a moving fin of variable thermal conductivity is studied. The differential transformation method (DTM is applied for an analytic solution for heat transfer in fin with two different profiles. Fin profiles are rectangular and exponential. The accuracy of analytic solution is validated by comparing it with the numerical solution that is obtained by fourth-order Runge-Kutta method. The analytical and numerical results are shown for different values of the embedding parameters. DTM results show that series converge rapidly with high accuracy. The results indicate that the fin tip temperature increases when ambient temperature increases. Conversely, the fin tip temperature decreases with an increase in the Peclet number, convection-conduction and radiation-conduction parameters. It is shown that the fin tip temperature of the exponential profile is higher than the rectangular one. The results indicate that the numerical data and analytical method are in a good agreement with each other.

  17. Experimental research of inclined-micro-fin flat tube on single phase convection heat transfer

    International Nuclear Information System (INIS)

    Fan Guangming; Sun Zhongning; Wang Meng

    2011-01-01

    The experimental research of heat transfer and flow resistance characteristics of single phase water in four inclined-micro-fin flat tubes with different physical dimensions was conducted. At the same time,suitable criteria were selected to evaluate the efficiency of inclined-micro-fin flat tubes within the experimental scope and the optimal working region was determined. The results indicate that inclined-micro-fin flat tubes can greatly enhance the single-phase heat transfer in turbulent flow and the maximum heat transfer coefficient attains to 5.9 times of that in smooth tube. The quantities of heat transfer for inclined-micro-fin flat tubes are three times higher than that of smooth tube with the same of heat exchange area and pump power. (authors)

  18. Investigation of internally finned LED heat sinks

    Science.gov (United States)

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

    2018-03-01

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

  19. The shark's fin

    International Nuclear Information System (INIS)

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

    1989-01-01

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

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

    KAUST Repository

    Diab, Amer El Hajj

    2014-12-01

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

  1. A Biologically Derived Pectoral Fin for Yaw Turn Manoeuvres

    Directory of Open Access Journals (Sweden)

    Jonah R. Gottlieb

    2010-01-01

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

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

    International Nuclear Information System (INIS)

    Wongwises, Somchai; Chokeman, Yutasak

    2005-01-01

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

  3. Experimental Study on Cooling Heat Transfer of Supercritical Carbon Dioxide Inside Horizontal Micro-Fin Tubes

    Science.gov (United States)

    Kuwahara, Ken; Higashiiu, Shinya; Ito, Daisuke; Koyama, Shigeru

    This paper deals with the experimental study on cooling heat transfer of supercritical carbon dioxide inside micro-fin tubes. The geometrical parameters in micro-fin tubes used in the present study are 6.02 mm in outer diameter, 4.76 mm to 5.11 mm in average inner diameter, 0.15 mm to 0.24 mm in fin height, 5 to 25 in helix angle, 46 to 52 in number of fins and 1.4 to 2.3 in area expansion ratio. Heat transfer coefficients were measured at 8-10 MPa in pressure, 360-690 kg/(m2•s) in mass velocity and 20-75 °C in CO2 temperature. The measured heat transfer coefficients of micro-fin tubes were 1.4 to 2 times higher than those of the smooth tube having 4.42 in inner diameter. The predicted heat transfer coefficients using the correlation equation, which was developed for single-phase turbulent fluid flow inside micro-fin-tubes, showed large deviations to the measured values. The new correlation to predict cooling heat transfer coefficient of supercritical carbon dioxide inside micro-fin tubes was developed taking into account the shape of fins based on experimental data empirically. This correlation equation agreed within ±20% of almost all of the experimental data.

  4. Performance of tubes-and plate fins heat exchangers

    International Nuclear Information System (INIS)

    Rosman, E.C.

    1979-11-01

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

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

    Science.gov (United States)

    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.

  6. FinFET modeling for IC simulation and design

    CERN Document Server

    Hu, Chenming; Lu, Darsen D

    2015-01-01

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

  7. A biorobotic pectoral fin for autonomous undersea vehicles.

    Science.gov (United States)

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

    2006-01-01

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

  8. FinTech in Denmark

    OpenAIRE

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

    2017-01-01

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

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

    International Nuclear Information System (INIS)

    Hajabdollahi, Hassan

    2015-01-01

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

  10. Flexible nanoscale high-performance FinFETs

    KAUST Repository

    Sevilla, Galo T.

    2014-10-28

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

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

    DEFF Research Database (Denmark)

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

    2017-01-01

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

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

    OpenAIRE

    Hung, Jui-long; Luo, Binjie

    2016-01-01

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

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

    Science.gov (United States)

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

    2014-01-15

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

  14. Strain relaxation of germanium-tin (GeSn) fins

    Science.gov (United States)

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

    2018-02-01

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

  15. Discharging process of a finned heat pipe–assisted thermal energy storage system with high temperature phase change material

    International Nuclear Information System (INIS)

    Tiari, Saeed; Qiu, Songgang; Mahdavi, Mahboobe

    2016-01-01

    Highlights: • The discharging process of a latent heat thermal energy storage system is studied. • The thermal energy storage system is assisted by finned heat pipes. • The influences of heat pipe spacing and fins geometrical features are studied. • Smaller heat pipe spacing enhances the solidification rate. • Better heat pipe and fin arrangements are determined. - Abstract: This paper presents the results of a numerical study conducted to investigate the discharging process of a latent heat thermal energy storage system assisted by finned heat pipes. A two-dimensional finite volume based numerical model along with enthalpy-porosity technique is employed to simulate the phase change of storage media during the discharging mode. The thermal energy storage system in this study consists of a square container, finned heat pipes, and potassium nitrate (KNO 3 ) as the phase change material. The charging process of the same thermal energy storage system was reported in an early paper by the authors. This paper reports the results of discharging process of the thermal energy storage system. The influences of heat pipe spacing, fin geometry and quantities as well as the effects of natural convection heat transfer on the thermal performance of the storage system were studied. The results indicate that the phase change material solidification process is hardly affected by the natural convection. Decreasing the heat pipe spacing results in faster discharging process and higher container base wall temperature. Increasing the fins length does not change the discharging time but yields higher base wall temperature. Using more fins also accelerates the discharging process and increases the container base wall temperature.

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

    Directory of Open Access Journals (Sweden)

    Taler Dawid

    2014-06-01

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

  17. Open Channel Natural Convection Heat Transfer on a Vertical Finned Plate

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  18. A note on the heat transfer in convective fins

    International Nuclear Information System (INIS)

    Razelos, P.

    1979-01-01

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

  19. Criteria for analysis and optimization of longitudinal fins with convective tip

    International Nuclear Information System (INIS)

    Gomes, E.S.

    1983-01-01

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

  20. Study on Fins' Effect of Boiling Flow in Millimeter Channel Heat Exchanger

    Science.gov (United States)

    Watanabe, Satoshi

    2005-11-01

    Recently, a lot of researches about compact heat exchangers with mini-channels have been carried out with the hope of obtaining a high-efficiency heat transfer, due to the higher ratio of surface area than existing heat exchangers. However, there are many uncertain phenomena in fields such as boiling flow in mini-channels. Thus, in order to understand the boiling flow in mini-channels to design high-efficiency heat exchangers, this work focused on the visualization measurement of boiling flow in a millimeter channel. A transparent acrylic channel (heat exchanger form), high-speed camera (2000 fps at 1024 x 1024 pixels), and halogen lamp (backup light) were used as the visualization system. The channel's depth is 2 mm, width is 30 mm, and length is 400 mm. In preparation for commercial use, two types of channels were experimented on: a fins type and a normal slit type (without fins). The fins are circular cylindrical obstacles (diameter is 5 mm) to promote heat transfer, set in a triangular array (distance between each center point is 10 mm). Especially in this work, boiling flow and heat transfer promotion in the millimeter channel heat exchanger with fins was evaluated using a high-speed camera.

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

    Science.gov (United States)

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

    2011-07-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-06-15

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

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  6. High performance flexible CMOS SOI FinFETs

    KAUST Repository

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

    2014-01-01

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

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

    Science.gov (United States)

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

    2016-04-01

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

  8. Numerical simulation of heat exchangers elliptical tubes and corrugated fins

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  9. ED50 and ED95 of Intrathecal Bupivacaine Coadministered with Sufentanil for Cesarean Delivery Under Combined Spinal-epidural in Severely Preeclamptic Patients

    Institute of Scientific and Technical Information of China (English)

    Fei Xiao; Wen-Ping Xu; Xiao-Min Zhang; Yin-Fa Zhang; Li-Zhong Wang; Xin-Zhong Chen

    2015-01-01

    Background:Spinal anesthesia was considered as a reasonable anesthetic option in severe preeclampsia when cesarean delivery is indicated,and there is no indwelling epidural catheter or contraindication to spinal anesthesia.However,the ideal dose of intrathecal bupivacaine has not been quantified for cesarean delivery for severe preeclamptic patients.This study aimed to determine the ED50 and ED95 of intrathecal bupivacaine for severely preeclamptic patients undergoing elective cesarean delivery.Methods:Two hundred severely preeclamptic patients are undergoing elective cesarean delivery under combined spinal-epidural anesthesia enrolled in this randomized,double-blinded,dose-ranging study.Patients received 4 mg,6 mg,8 mg,or 10 mg intrathecal hyperbaric bupivacaine with 2.5 μg sufentanil.Successful spinal anesthesia was defined as a T6 sensory level achieved within 10 minutes after intrathecal drug administration and/or no epidural supplement was required during the cesarean section.The ED50 and ED95 were calculated with a logistic regression model.Results:ED50 and ED95 ofintrathecal bupivacaine for successful spinal anesthesia were 5.67 mg (95％ confidence interval [CI]:5.20-6.10 mg) and 8.82 mg (95％ CI:8.14-9.87 mg) respectively.The incidence of hypotension in Group 8 mg and Group 10 mg was higher than that in Group 4 mg and Group 6 mg (P ＜ 0.05).The sensory block was significantly different among groups 10 minutes after intrathecal injection (P ＜ 0.05).The use of lidocaine in Group 4 mg was higher than that in other groups (P ＜ 0.05).The use of phenylephrine in Group 8 mg and Group 10 mg was higher than that in the other two groups (P ＜ 0.05).The lowest systolic blood pressure before the infant delivery of Group 8 mg and Group 10 mg was lower than the other two groups (P ＜ 0.05).The satisfaction of muscle relaxation in Group 4 mg was lower than other groups (P ＜ 0.05).There was no significant difference in patients' satisfaction and the newborns

  10. Iterative solution of fluid flow in finned tubes

    International Nuclear Information System (INIS)

    Syed, S.K.; Tuphome, E.G.; Wood, S.A.

    2004-01-01

    A difference-based numerical algorithm is developed to efficiently solve a class of elliptic boundary value problems up to any desired order of accuracy. Through multi-level discretization the algorithm uses the multigrid concept of nested iterations to accelerate the convergence rate at higher discretization levels and exploits the advantages of extrapolation methods to achieve higher order accuracy with less computational work. The algorithm employs the SOR method to solve the discrete problem at each discretization level by using an estimated optimum value of the relaxation parameter. The advantages of the algorithm are shown through comparison with the simple discrete method for simulations of fluid flows in finned circular ducts. (author)

  11. DETERMINATION OF THE TEMPERATURE DISTRIBUTION THE PERFORATED FINS UNDER

    Directory of Open Access Journals (Sweden)

    Aziz7 M. Mhamuad

    2015-02-01

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

  12. The Effect of Fin Pitch on Fluid Elastic Instability of Tube Arrays Subjected to Cross Flow of Water

    Science.gov (United States)

    Desai, Sandeep Rangrao; Pavitran, Sampat

    2018-02-01

    flow capacity of the pump. The tests are carried out first on plain tube arrays to establish the same as the datum case and results are compared to known results of plain tube arrays and hence the quality of the test rig is also assessed. The fluid elastic vibration tests are then carried out on finned tube arrays with coarse and fine fin pitches and effects of fins and fin pitch on instability threshold are shown. The vibration response of the tube is recorded for each gradually increasing flow rates of water till instability point is reached. The parameters at the instability are then presented in terms of dimensionless parameters to compare them with published results. It is concluded that, arrays with higher pitch ratios are unstable at comparatively higher flow velocities and instability threshold for finned tube arrays is delayed due to addition of the fins. Further, it is concluded that, instability threshold for finned tube arrays with fine fin pitch is delayed compared to coarse fin pitch and hence for increased fin density, instability threshold is delayed. The experimental results in terms of critical velocities obtained for different tube arrays subjected to water cross flow will serve as the base flow rates for air-water cross flow experiments to be conducted in the next phase.

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

    Science.gov (United States)

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

    2015-01-01

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

  14. Zgaga, P., Teichler, U., & Brennan, J. (Eds.) (2012). The globalisation challenge for European higher education / Convergence and Diversity, Centres and Peripheries. Frankfurt/M.: Peter Lang. [Book review

    OpenAIRE

    Strajn, Darko

    2013-01-01

    Book review of: Zgaga, P., Teichler, U., & Brennan, J. (Eds.) (2012). The globalisation challenge for European higher education / Convergence and Diversity, Centres and Peripheries. Frankfurt/M.: Peter Lang. 389 pp., ISBN 978-3-631- 6398-5.

  15. Atom-probe for FinFET dopant characterization

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-05-15

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

  16. Atom-probe for FinFET dopant characterization

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  17. Study of Swept Angle Effects on Grid Fins Aerodynamics Performance

    Science.gov (United States)

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

    2018-04-01

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

  18. Optimization of Peripheral Finned-Tube Evaporators Using Entropy Generation Minimization

    OpenAIRE

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

    2012-01-01

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

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

    Science.gov (United States)

    Feilich, Kara L

    2016-10-01

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

  20. Analysis of the heat transfer mechanisms during energy storage in a Phase Change Material filled vertical finned cylindrical unit for free cooling application

    International Nuclear Information System (INIS)

    Solomon, Gnanadurai Ravikumar; Velraj, Ramalingam

    2013-01-01

    Highlights: • Freezing behavior of a PCM, in a cylinder with annular longitudinal fins is presented. • Among various fin heights, 20 mm fin contribute maximum heat transfer enhancement. • Addition of fins plays a contradictory role during the sensible cooling of liquid PCM. • The fin effect along with external cooling, vary the sensible cooling rate of liquid PCM. • The surface convective resistance dominated over the conductive resistance of PCM. - Abstract: The heat transfer performance of the Phase Change Material (PCM) used in free cooling application is low due to poor thermal conductivity. The addition of fins to enhance the heat transfer during solidification process is commonly employed, to address this. However for application such as free cooling, where the driving temperature potential is very less, the present experimental study is intended to investigate the sensible and subcooling phenomena during the outward cylindrical solidification of the PCM stored on the annulus side, along with 8 longitudinal uniformly spaced copper fins of different heights. The performance of the fins during solidification is analyzed, and the best suitable height is arrived at. The addition of fins plays a contradicting role during the sensible cooling of the liquid PCM, due to the suppression of free convection. The external cooling conditions along with the effect of the fin, vary the sensible cooling rate of the liquid PCM, that influences the subcooling effect, and also drifts the temperature at which major phase change occurs. In addition, the effects due to the inlet velocity of the heat transfer fluid, and its temperature on heat transfer are investigated and reported. The increase in velocity decreases the duration of solidification, and this effect is more pronounced towards the entry region, due to the higher local convective heat transfer co-efficient and a comparatively higher driving temperature potential

  1. Fin de Copenhague

    DEFF Research Database (Denmark)

    Baumeister, Ruth

    2016-01-01

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

  2. The optimization of longitudinal convective fins with internal heat generation

    International Nuclear Information System (INIS)

    Razelos, P.

    1979-01-01

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

  3. Heat/mass transfer on effusion plate with circular pin fins for impingement/effusion cooling system with initial crossflow

    International Nuclear Information System (INIS)

    Hong, Sung Kook; Rhee, Dong Ho; Cho, Hyung Hee

    2005-01-01

    Impingement/effusion cooling technique is used for combustor liner or turbine parts cooling in gas turbine engine. In the impingement/effusion cooling system, the crossflow generated in the cooling channel induces an adverse effect on the cooling performance, which consequently affects the durability of the cooling system. In the present study, to reduce the adverse effect of the crossflow and improve the cooling performance, circular pin fins are installed in impingement/effusion cooling system and the heat transfer characteristics are investigated. The pin fins are installed between two perforated plates and the crossflow passes between these two plates. A blowing ratio is changed from 0.5 to 1.5 for the fixed jet Reynolds number of 10,000 and five circular pin fin arrangements are considered in this study. The local heat/mass transfer coefficients on the effusion plate are measured using a naphthalene sublimation method. The results show that local distributions of heat/mass transfer coefficient are changed due to the installation of pin fins. Due to the generation of vortex and wake by the pin fin, locally low heat/mass transfer regions are reduced. Moreover, the pin fin prevents the wall jet from being swept away, resulting in the increase of heat/mass transfer. When the pin fin is installed in front of the impinging jet, the blockage effect on the crossflow enhances the heat/mass transfer. However, the pin fin installed just behind the impinging jet blocks up the wall jet, decreasing the heat/mass transfer. As the blowing ratio increases, the pin fins lead to the higher Sh value compared to the case without pin fins, inducing 16%∼22% enhancement of overall Sh value at high blowing ratio of M=1.5

  4. Research on dynamic characteristics of new chaotic-advection fins

    International Nuclear Information System (INIS)

    Kong Songtao; Dong Qiwu; Liu Minshan; Zhu Qing

    2007-01-01

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

  5. Stress analysis of plate-fin structures in recuperator

    International Nuclear Information System (INIS)

    Matsui, Shingo; Muto, Yasushi; Shiina, Yasuaki

    2001-01-01

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

  6. Strain characterization of FinFETs using Raman spectroscopy

    International Nuclear Information System (INIS)

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

    2013-01-01

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

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

    Science.gov (United States)

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

    2014-08-01

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

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

    Institute of Scientific and Technical Information of China (English)

    徐扬; 刘姝雯; 腾菲; 罗晶

    2017-01-01

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

  9. Forced convection heat transfer correlation for finned plates in a duct

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  10. TED-Ed lessons & TED-Ed clubs: Educational activities to amplify students' voices

    Science.gov (United States)

    Villias, Georgios

    2017-04-01

    TED-Ed lessons and TED-Ed clubs are two powerful educational tools that can be used in today's school classrooms in order to create an educational environment that is engaging for the students and favors their active participation, created and fostered by TED-Ed. TED-Ed is TED's educational initiative, committed to create lessons worth sharing and amplify the voices and ideas of teachers and students around the world. TED-Ed animated lessons are fully organized lessons structured around an animated video that introduces new topics to learners in an exciting, thought-provoking way. These lessons have been created as a result of the cooperation between expert educators and animators and have been uploaded at the TED-Ed platform (http://ed.ted.com). On the other hand, TED-Ed Clubs are also an interesting way to offer students the chance, the voice and the opportunity to express their thoughts, engage actively on these matters and connect with each other, both at a local, as well as at an international level (http://ed.ted.com/clubs). By developing new TED-Ed lessons or by customizing appropriately existing animated TED-Ed lessons (translating, modifying the questions asked, introducing new discussion topics), I have created and implemented in my student-centered, didactic approach, a series of TED-ED animated lessons directly connected with the Greek national science syllabus that were used to spark students curiosity and initiate a further analytical discussion or introduce other relevant educational activities (http://gvillias.wixsite.com/education). Furthermore, at my school, we established Varvakeio TED-Ed Club, an environment that supports and empowers our students to research, develop and disseminate their own personal ideas that worth spreading. During the year, our members were inspired by watching TED talks presented by experts on their field on various different areas, including social, economical, environmental and technological-scientific issues. Our aim

  11. Externally finned circular tube immerse in a phase-change material

    International Nuclear Information System (INIS)

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

    1985-01-01

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

  12. Characterising non-urgent users of the emergency department (ED: A retrospective analysis of routine ED data.

    Directory of Open Access Journals (Sweden)

    Colin O'Keeffe

    Full Text Available The pressures of patient demand on emergency departments (EDs continue to be reported worldwide, with an associated negative impact on ED crowding and waiting times. It has also been reported that a proportion of attendances to EDs in different international systems could be managed in settings such as primary care. This study used routine ED data to define, measure and profile non-urgent ED attendances that were suitable for management in alternative, non-emergency settings.We undertook a retrospective analysis of three years of Hospital Episode and Statistics Accident Emergency (HES A&E data for one large region in England, United Kingdom (April 1st 2011 to March 31st 2014. Data was collected on all adult (>16 years ED attendances from each of the 19 EDs in the region. A validated process based definition of non-urgent attendance was refined for this study and applied to the data. Using summary statistics non-urgent attenders were examined by variables hypothesised to influence them as follows: age at arrival, time of day and day of week and mode of arrival. Odds ratios were calculated to compare non-urgent attenders between groups.There were 3,667,601 first time attendances to EDs, of which 554,564 were defined as non-urgent (15.1%. Non-urgent attendances were significantly more likely to present out of hours than in hours (OR = 1.19, 95% CI: 1.18 to 1.20, P<0.001. The odds of a non-urgent attendance were significantly higher for younger patients (aged 16-44 compared to those aged 45-64 (odds ratio: 1.42, 95% CI: 1.41 to 1.43, P<0.001 and the over 65's (odds ratio: 3.81, 95% CI: 3.78 to 3.85, P<0.001. Younger patients were significantly more likely to attend non-urgently out of hours compared to the 45-64's (OR = 1.24, 95% CI: 1.22 to 1.25, P<0.001 and the 65+'s (OR = 1.38, 95% CI: 1.35 to 1.40, P<0.001. 110,605/554,564 (19.9% of the non-urgent attendances arrived by ambulance, increasing significantly out of hours versus in hours (OR = 2

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

    Science.gov (United States)

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

    2018-04-01

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

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  15. Vortex Shedding from Finned Circular Cylinders

    Science.gov (United States)

    1980-11-01

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

  16. Comparison of heat pump performance using fin-and-tube and microchannel heat exchangers under frost conditions

    International Nuclear Information System (INIS)

    Shao, Liang-Liang; Yang, Liang; Zhang, Chun-Lu

    2010-01-01

    Vapor compression heat pumps are drawing more attention in energy saving applications. Microchannel heat exchangers can provide higher performance via less core volume and reduce system refrigerant charge, but little is known about their performance in heat pump systems under frosting conditions. In this study, the system performance of a commercial heat pump using microchannel heat exchangers as evaporator is compared with that using conventional finned-tube heat exchangers numerically and experimentally. The microchannel and finned-tube heat pump system models used for comparison of the microchannel and finned-tube evaporator performance under frosting conditions were developed, considering the effect of maldistribution on both refrigerant and air sides. The quasi-steady-state modeling results are in reasonable agreement with the test data under frost conditions. The refrigerant-side maldistribution is found remarkable impact on the microchannel heat pump system performance under the frost conditions. Parametric study on the fan speed and the fin density under frost conditions are conducted as well to figure out the best trade-off in the design of frost tolerant evaporators. (author)

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

    Science.gov (United States)

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

    2017-10-01

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

  18. Organochlorine pesticides and polychlorinated biphenyls in fin whales (Balaenoptera physalus) from the Gulf of California.

    Science.gov (United States)

    Niño-Torres, Carlos Alberto; Zenteno-Savín, Tania; Gardner, Susan C; Urbán R, Jorge

    2010-08-01

    The present study reports unique data on concentrations of several classes of organochlorine pesticides and polychlorinated biphenyls in blubber biopsies from healthy living fin whales (Balaenoptera physalus) from the Gulf of California, Mexico, one of the most isolated and unstudied population in the world. OC levels in this population were generally lower than levels reported in fin whales from other regions. The rank order of OCs were SigmaDDTs (range from 300 to 2400 ng g(-1) lw) > SigmaPCBs (range from 40 to 290 ng g(-1) lw) > SigmaHCHs (range from or = SigmaCHLORs (from pesticide measured was the DDT metabolite, p,p'-DDE. The PCBs 138, 153, and 180 were the most abundant PCBs congeners found in the fin whales samples. Males had significant higher concentrations of SigmaOC, SigmaDDTs and SigmaPCBs than females (P < 0.05), although the p,p'-DDE/SigmaDDTs ratios were similar between the sexes. Although the OC concentrations found in this population were generally below the levels that would be expected to cause deleterious health effects, the maximum values observed (2700 ng g(-1) lw) in some animals were higher than those associated with reproductive effects in whales. Given the small population size and highly isolated characteristics of Gulf of California fin whales, health effects in individuals could readily translate into population-level effects. Future research on this topic will be necessary to better understand the role that these compounds may have on the health of this population.

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

    Directory of Open Access Journals (Sweden)

    Sarah V Gerhart

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

  20. Hydrodynamical analysis of the effect of fish fins morphology

    Science.gov (United States)

    Azwadi Che Sidik, Nor; Yen, Tey Wah

    2013-12-01

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

  1. Changing Public Perceptions of Higher Ed

    Science.gov (United States)

    Harney, John O.

    2018-01-01

    The benefits of going to college and the importance of higher education institutions were once held to be a creed as American as apple pie. But recurring state budget challenges have constrained investment. Consistently rising tuitions--fueled by increasing college costs--have alarmed many. Politics and free-speech controversies have raised…

  2. On the Hydrodynamics of Anomalocaris Tail Fins.

    Science.gov (United States)

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

    2018-04-25

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

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

    International Nuclear Information System (INIS)

    Aziz, Abdul; Beers-Green, Arlen B.

    2009-01-01

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

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Mohsen Siahmansouri

    2011-11-01

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

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

    OpenAIRE

    Zavolokina, Liudmila; Dolata, Mateusz; Schwabe, Gerhard

    2016-01-01

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

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

    Science.gov (United States)

    Bozkurttas, M.; Madden, P.

    2005-11-01

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

  8. Thermohydraulic analysis of smooth and finned annular ducts

    International Nuclear Information System (INIS)

    Braga, C.V.M.

    1987-01-01

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

  9. Heat transfer and pressure drop characteristics of mini-fin structures

    International Nuclear Information System (INIS)

    Jiang Peixue; Xu Ruina

    2007-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Hua-Shu Dou

    2015-01-01

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

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

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

    International Nuclear Information System (INIS)

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

    1981-01-01

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

  13. Heat transfer from rotating finned heat exchangers with different orientation angles

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-03-15

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

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

    Science.gov (United States)

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

    2017-10-01

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

  15. Control characteristics for wrap-around fins on cruise missiles configurations

    Science.gov (United States)

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

    1981-01-01

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

  16. Thermal analysis of annular fins with temperature-dependent thermal properties

    Institute of Scientific and Technical Information of China (English)

    I. G. AKSOY

    2013-01-01

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

  17. Pectoral fin contact as a mechanism for social bonding among dolphins

    Science.gov (United States)

    Dudzinski, Kathleen; Ribic, Christine

    2017-01-01

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

  18. Inform@ed space

    DEFF Research Database (Denmark)

    Bjerrum, Peter; Olsen, Kasper Nefer

    2001-01-01

    Inform@ed space Sensorial Perception And Computer Enchancement - bidrag til Nordisk Arkitekturforskningsforenings IT-konference, AAA april 2001.......Inform@ed space Sensorial Perception And Computer Enchancement - bidrag til Nordisk Arkitekturforskningsforenings IT-konference, AAA april 2001....

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

    International Nuclear Information System (INIS)

    Muzzio, A.

    2001-01-01

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

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

    Science.gov (United States)

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

    2014-12-01

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

  1. Fgf16 is essential for pectoral fin bud formation in zebrafish

    International Nuclear Information System (INIS)

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

    2006-01-01

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

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

    Science.gov (United States)

    Reiss, Katie L; Bonnan, Matthew F

    2010-07-01

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

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

    International Nuclear Information System (INIS)

    Ishiyama, Shintaro; Muto, Yasushi

    2003-01-01

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

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

    Science.gov (United States)

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

    2017-11-01

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

  5. Development of a Simulation Model for Swimming with Diving Fins

    Directory of Open Access Journals (Sweden)

    Motomu Nakashima

    2018-02-01

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

  6. En Defensa del Fin de Lucro en Salud.

    Directory of Open Access Journals (Sweden)

    Ramón Abel Castaño Yepes

    2007-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Chul-Min Jung

    2017-01-01

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

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

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

    KAUST Repository

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

    2015-01-01

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

  10. Higher Ed Meets Public Ed.

    Science.gov (United States)

    Olenick, Mary Jo

    1996-01-01

    The University of Connecticut is revitalizing the Avery Point campus with two new buildings. A Marine Sciences and Technology Center will serve graduate and undergraduate students. A separate Marine Sciences Field Station/Hostel will house Project Oceanology: a science program for students in grades 5-12. (MLF)

  11. Numerical studies of static aeroelastic effects on grid fin aerodynamic performances

    Directory of Open Access Journals (Sweden)

    Chengde HUANG

    2017-08-01

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

  12. Integrated Rudder/Fin Concise Control Based on Frequency Domain Analysis

    OpenAIRE

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

    2013-01-01

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

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

    Science.gov (United States)

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

    2017-11-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-04-15

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

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

    International Nuclear Information System (INIS)

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

    2017-01-01

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

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

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  17. FIN5 positively regulates far-red light responses in Arabidopsis thaliana

    International Nuclear Information System (INIS)

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

    2003-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    钟鸣长

    2016-01-01

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

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

    NARCIS (Netherlands)

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

    1999-01-01

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

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

    Science.gov (United States)

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

    2017-12-01

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

  1. Robotic Pectoral Fin Thrust Vectoring Using Weighted Gait Combinations

    Directory of Open Access Journals (Sweden)

    John S. Palmisano

    2012-01-01

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

  2. TaEDS1 genes positively regulate resistance to powdery mildew in wheat.

    Science.gov (United States)

    Chen, Guiping; Wei, Bo; Li, Guoliang; Gong, Caiyan; Fan, Renchun; Zhang, Xiangqi

    2018-04-01

    Three EDS1 genes were cloned from common wheat and were demonstrated to positively regulate resistance to powdery mildew in wheat. The EDS1 proteins play important roles in plant basal resistance and TIR-NB-LRR protein-triggered resistance in dicots. Until now, there have been very few studies on EDS1 in monocots, and none in wheat. Here, we report on three common wheat orthologous genes of EDS1 family (TaEDS1-5A, 5B and 5D) and their function in powdery mildew resistance. Comparisons of these genes with their orthologs in diploid ancestors revealed that EDS1 is a conserved gene family in Triticeae. The cDNA sequence similarity among the three TaEDS1 genes was greater than 96.5%, and they shared sequence similarities of more than 99.6% with the respective orthologs from diploid ancestors. The phylogenetic analysis revealed that the EDS1 family originated prior to the differentiation of monocots and dicots, and EDS1 members have since undergone clear structural differentiation. The transcriptional levels of TaEDS1 genes in the leaves were obviously higher than those of the other organs, and they were induced by Blumeria graminis f. sp. tritici (Bgt) infection and salicylic acid (SA) treatment. The BSMV-VIGS experiments indicated that knock-down the transcriptional levels of the TaEDS1 genes in a powdery mildew-resistant variety of common wheat compromised resistance. Contrarily, transient overexpression of TaEDS1 genes in a susceptible common wheat variety significantly reduced the haustorium index and attenuated the growth of Bgt. Furthermore, the expression of TaEDS1 genes in the Arabidopsis mutant eds1-1 complemented its susceptible phenotype to powdery mildew. The above evidences strongly suggest that TaEDS1 acts as a positive regulator and confers resistance against powdery mildew in common wheat.

  3. Heat transfer in laminar flow for a finned double - tube

    International Nuclear Information System (INIS)

    Colle, S.

    1977-01-01

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

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

    Science.gov (United States)

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

    2006-01-01

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

  5. Enhanced Freshwater Production Using Finned-Plate Air Gap Membrane Distillation (AGMD

    Directory of Open Access Journals (Sweden)

    Perves Bappy Mohammad Jabed

    2017-01-01

    Full Text Available Air Gap membrane distillation (AGMD, a special type of energy efficient membrane distillation process, is a technology for producing freshwater from waste water. Having some benefits over other traditional processes, this method has been able to draw attention of researchers working in the field of freshwater production technologies. In this study, a basic AGMD system with flat coolant plate has been modified using a specially designed channelled coolant plate of portable size to observe its effect over the production rate and performance of the system. Attempt has been made to increase the amount of distillate flux by using the “fin effect” of the channelled coolant plate. A finned plate have been used instead of a flat coolant plate and experiments were conducted to compare the effect. Coolant temperature and feed temperature of the system have been varied from 10°C to 25°C and 40°C to 70°C respectively. Comparing the data, around 50% to 58% distillate enhancement has been observed for channelled coolant plate. Also, it was seen that the enhancement was higher for higher feed temperatures and coolant temperatures. With these findings, a better performing AGMD module has been introduced to mitigate the scarcity of freshwater.

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

    Science.gov (United States)

    Bose, N; Lien, J

    1989-07-22

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

  7. Nurturing a FinTech Ecosystem

    DEFF Research Database (Denmark)

    Leong, Carmen; Tan, Barney; Xiao, Xiao

    2017-01-01

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

  8. Optimization of geometric parameters of heat exchange pipes pin finning

    Science.gov (United States)

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

    2018-05-01

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

  9. Numerical simulation of natural convection in annuli with internal fins

    International Nuclear Information System (INIS)

    Ha, Man Yeong; Kim, Joo Goo

    2004-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Chii-Dong Ho

    2013-10-01

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

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  12. Fin field effect transistor directionality impacts printing of implantation shapes

    Science.gov (United States)

    Wang, Xiren; Granik, Yuri

    2018-01-01

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

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

    OpenAIRE

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

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Okbaz Abdulkerim

    2017-01-01

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

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

    Science.gov (United States)

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

    2016-05-01

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

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

    Institute of Scientific and Technical Information of China (English)

    熊琦

    2018-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2012-01-01

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

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

    International Nuclear Information System (INIS)

    Fry, C.J.

    1985-08-01

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

  19. Effect of fin attachment on thermal stress reduction of exhaust manifold of an off road diesel engine

    Institute of Scientific and Technical Information of China (English)

    Ali; Akbar; Partoaa; Morteza; Abdolzadeh; Masoud; Rezaeizadeh

    2017-01-01

    The effect of fin attachment on the thermal stress reduction of exhaust manifold of an off road diesel engine(Komatsu HD325-6) was investigated.For doing this,coupled thermo-fluid-solid analysis of exhaust manifold of the off road diesel engine was carried out.The thermal analysis,including thermal flow,thermal stress,and the thermal deformation of the manifold was investigated.The flow inside the manifold was simulated and then its properties including velocity,pressure,and temperature were obtained.The flow properties were transferred to the solid model and then the thermal stresses and the thermal deformations of the manifold under different operating conditions were calculated.Finally,based on the predicted thermal stresses and thermal deformations of the manifold body shell,two fin types as well as body shell thickness increase were applied in the critical induced thermal stress area of the manifold to reduce the thermal stress and thermal deformation.The results of the above modifications show that the combined modifications,i.e.the thickness increase and the fin attachment,decrease the thermal stresses by up to 28% and the contribution of the fin attachment in this reduction is much higher compared to the shell thickness increase.

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

    Science.gov (United States)

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

    2014-01-01

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

  1. Evaluation of integrally finned cladding for LMFBR fuel pins

    International Nuclear Information System (INIS)

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

    1975-01-01

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

  2. Mechanical Ventilation and ARDS in the ED: A Multicenter, Observational, Prospective, Cross-sectional Study.

    Science.gov (United States)

    Fuller, Brian M; Mohr, Nicholas M; Miller, Christopher N; Deitchman, Andrew R; Levine, Brian J; Castagno, Nicole; Hassebroek, Elizabeth C; Dhedhi, Adam; Scott-Wittenborn, Nicholas; Grace, Edward; Lehew, Courtney; Kollef, Marin H

    2015-08-01

    There are few data regarding mechanical ventilation and ARDS in the ED. This could be a vital arena for prevention and treatment. This study was a multicenter, observational, prospective, cohort study aimed at analyzing ventilation practices in the ED. The primary outcome was the incidence of ARDS after admission. Multivariable logistic regression was used to determine the predictors of ARDS. We analyzed 219 patients receiving mechanical ventilation to assess ED ventilation practices. Median tidal volume was 7.6 mL/kg predicted body weight (PBW) (interquartile range, 6.9-8.9), with a range of 4.3 to 12.2 mL/kg PBW. Lung-protective ventilation was used in 122 patients (55.7%). The incidence of ARDS after admission from the ED was 14.7%, with a mean onset of 2.3 days. Progression to ARDS was associated with higher illness severity and intubation in the prehospital environment or transferring facility. Of the 15 patients with ARDS in the ED (6.8%), lung-protective ventilation was used in seven (46.7%). Patients who progressed to ARDS experienced greater duration in organ failure and ICU length of stay and higher mortality. Lung-protective ventilation is infrequent in patients receiving mechanical ventilation in the ED, regardless of ARDS status. Progression to ARDS is common after admission, occurs early, and worsens outcome. Patient- and treatment-related factors present in the ED are associated with ARDS. Given the limited treatment options for ARDS, and the early onset after admission from the ED, measures to prevent onset and to mitigate severity should be instituted in the ED. ClinicalTrials.gov; No.: NCT01628523; URL: www.clinicaltrials.gov.

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

    International Nuclear Information System (INIS)

    Ding Ming; Yan Changqi; Sun Licheng

    2007-01-01

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

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

    Science.gov (United States)

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

    2017-11-01

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

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

    Science.gov (United States)

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

    2013-01-01

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

  6. New EdF's three challenges

    International Nuclear Information System (INIS)

    Lepetit, V.

    2005-01-01

    The opening of 15% of Electricite de France (EdF) capital to the private sector will allow the first world electric utility to raise 7 billions of euros of cash flow. EdF will have also to face the new European situation: a strained market, several consolidations to come and many competitors to deal with. EdF has to re-launch its production tool and to reinforce its interconnection capacities if it wants to stay the number one of power exports in Europe. The integration of Edison company (Italy) by EdF gives access to new gas capacities but other resources have to be found if EdF wants to enlarge its gas offer. A new concentration era is foreseen in Europe and EdF will have to seize the economic growth opportunities in particular in Europe and China. (J.S.)

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

    Science.gov (United States)

    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.

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

    International Nuclear Information System (INIS)

    Peng, Hao; Ling, Xiang; Li, Juan

    2014-01-01

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

  9. Thermoelectric generator with hinged assembly for fins

    International Nuclear Information System (INIS)

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

    1976-01-01

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

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

    International Nuclear Information System (INIS)

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

    2017-01-01

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

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

    Science.gov (United States)

    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."

  12. Combined natural convection heat and mass transfer from vertical fin arrays

    International Nuclear Information System (INIS)

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

    2003-01-01

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

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-07-01

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

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

    Science.gov (United States)

    Juan, Du; Hai-Tao, Zhao

    2018-03-01

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

  16. Numerical Modeling of Transient Heat Transfer in Longitudinal Fin

    Directory of Open Access Journals (Sweden)

    Farshad Panahizadeh

    2017-11-01

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

  17. A thermal study of pipes with outer transverse fins

    Directory of Open Access Journals (Sweden)

    S. Gil

    2016-10-01

    Full Text Available This paper provides results of thermal investigations on pipes with outer transverse fins produced by placing a strip, being a form of helical spring which functions as a radiator, on the basis pipe. The investigations were carried out at the facility that enables measurements with respect to both natural and forced convection. Performance of the investigated pipes was assessed in relation to a non-finned pipe and a pipe welded with the use of Metal Active Gas (MAG technology. The experiments have shown that the finned pipe welding technology does not markedly affect their thermal efficiency, which has been confirmed by performed model calculations, while the welding technology has a crucial impact on their operating performance.

  18. A two-phase flow regime map for a MAPLE-type nuclear research reactor fuel channel: Effect of hexagonal finned bundle

    International Nuclear Information System (INIS)

    Harvel, G.D.; Chang, J.S.

    1997-01-01

    A two-phase flow regime map is developed experimentally and theoretically for a vertical hexagonal flow channel with and without a 36-finned rod hexagonal bundle. This type of flow channel is of interest to MAPLE-type nuclear research reactors. The flow regime maps are determined by visual observations and observation of waveforms shown by a capacitance-type void fraction meter. The experimental results show that the inclusion of the finned hexagonal bundle shifts the flow regime transition boundaries toward higher water flow rates. Existing flow regime maps based on pipe flow require slight modifications when applied to the hexagonal flow channel with and without a MAPLE-type finned hexagonal bundle. The proposed theoretical model agrees well with experimental results

  19. High performance flexible CMOS SOI FinFETs

    KAUST Repository

    Fahad, Hossain M.

    2014-06-01

    We demonstrate the first ever CMOS compatible soft etch back based high performance flexible CMOS SOI FinFETs. The move from planar to non-planar FinFETs has enabled continued scaling down to the 14 nm technology node. This has been possible due to the reduction in off-state leakage and reduced short channel effects on account of the superior electrostatic charge control of multiple gates. At the same time, flexible electronics is an exciting expansion opportunity for next generation electronics. However, a fully integrated low-cost system will need to maintain ultra-large-scale-integration density, high performance and reliability - same as today\\'s traditional electronics. Up until recently, this field has been mainly dominated by very weak performance organic electronics enabled by low temperature processes, conducive to low melting point plastics. Now however, we show the world\\'s highest performing flexible version of 3D FinFET CMOS using a state-of-the-art CMOS compatible fabrication technique for high performance ultra-mobile consumer applications with stylish design. © 2014 IEEE.

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

    OpenAIRE

    Zheng Hui-Fan; Fan Xiao-Wei; Wang Fang; Liang Yao-Hua

    2013-01-01

    A theoretical analysis and experimental verification on the characteristics of a micro-fin evaporator using R290 and R717 as refrigerants were carried out. The heat capacity and heat transfer coefficient of the micro-fin evaporator were investigated under different water mass flow rate, different refrigerant mass flow rate, and different inner tube diameter of micro-fin evaporator. The simulation results of the heat transfer coefficient are fairly in good a...

  1. Fin whales and microplastics: The Mediterranean Sea and the Sea of Cortez scenarios

    International Nuclear Information System (INIS)

    Fossi, Maria Cristina; Marsili, Letizia; Baini, Matteo; Giannetti, Matteo; Coppola, Daniele; Guerranti, Cristiana; Caliani, Ilaria; Minutoli, Roberta; Lauriano, Giancarlo; Finoia, Maria Grazia; Rubegni, Fabrizio; Panigada, Simone; Bérubé, Martine; Urbán Ramírez, Jorge; Panti, Cristina

    2016-01-01

    The impact that microplastics have on baleen whales is a question that remains largely unexplored. This study examined the interaction between free-ranging fin whales (Balaenoptera physalus) and microplastics by comparing populations living in two semi-enclosed basins, the Mediterranean Sea and the Sea of Cortez (Gulf of California, Mexico). The results indicate that a considerable abundance of microplastics and plastic additives exists in the neustonic samples from Pelagos Sanctuary of the Mediterranean Sea, and that pelagic areas containing high densities of microplastics overlap with whale feeding grounds, suggesting that whales are exposed to microplastics during foraging; this was confirmed by the observation of a temporal increase in toxicological stress in whales. Given the abundance of microplastics in the Mediterranean environment, along with the high concentrations of Persistent Bioaccumulative and Toxic (PBT) chemicals, plastic additives and biomarker responses detected in the biopsies of Mediterranean whales as compared to those in whales inhabiting the Sea of Cortez, we believe that exposure to microplastics because of direct ingestion and consumption of contaminated prey poses a major threat to the health of fin whales in the Mediterranean Sea. - Highlights: • Microplastics and phthalates were higher in the Mediterranean Sea than in the Sea of Cortez. • The overlap between the whale feeding areas and high microplastic density shows the risk of interaction. • Data suggest an increasing risk of chemical transfer from microplastic to whales during the foraging. • Mediterranean whales are exposed to higher ecotoxicological threat of than Sea of Cortez whales. - This study identified temporal and regional ecotoxicological variations in free-ranging fin whales inhabiting two seas different characterized by different microplastic abundance.

  2. Optimization design of LED heat dissipation structure based on strip fins

    Science.gov (United States)

    Xue, Lingyun; Wan, Wenbin; Chen, Qingguang; Rao, Huanle; Xu, Ping

    2018-03-01

    To solve the heat dissipation problem of LED, a radiator structure based on strip fins is designed and the method to optimize the structure parameters of strip fins is proposed in this paper. The combination of RBF neural networks and particle swarm optimization (PSO) algorithm is used for modeling and optimization respectively. During the experiment, the 150 datasets of LED junction temperature when structure parameters of number of strip fins, length, width and height of the fins have different values are obtained by ANSYS software. Then RBF neural network is applied to build the non-linear regression model and the parameters optimization of structure based on particle swarm optimization algorithm is performed with this model. The experimental results show that the lowest LED junction temperature reaches 43.88 degrees when the number of hidden layer nodes in RBF neural network is 10, the two learning factors in particle swarm optimization algorithm are 0.5, 0.5 respectively, the inertia factor is 1 and the maximum number of iterations is 100, and now the number of fins is 64, the distribution structure is 8*8, and the length, width and height of fins are 4.3mm, 4.48mm and 55.3mm respectively. To compare the modeling and optimization results, LED junction temperature at the optimized structure parameters was simulated and the result is 43.592°C which approximately equals to the optimal result. Compared with the ordinary plate-fin-type radiator structure whose temperature is 56.38°C, the structure greatly enhances heat dissipation performance of the structure.

  3. A novel louvered fin design to enhance thermal and drainage performances during periodic frosting/defrosting conditions

    International Nuclear Information System (INIS)

    Kim, Min-Hwan; Kim, Hisuk; Kim, Dong Rip; Lee, Kwan-Soo

    2016-01-01

    Highlights: • Thermal and drainage performances of a novel design louvered fin were investigated. • The thermal performance of the asymmetric fin was improved in the re-frosting cycle. • The asymmetric louvered fin exhibited better drainage on the leading edge of fins. • Lower surface tension between fin surface and water droplet improved the drainage. - Abstract: The retention water on fin surface can significantly degrade the thermal performance of heat exchangers under periodic frosting/defrosting conditions, which also leads to a decrease in the energy efficiency of air-source heat pumps. A novel louvered fin design was suggested to improve the drainage and the thermal performance of heat exchanger. The novel louvered fin had an asymmetric louver arrangement by flattening two louvers on the leading edge. The retention water formed on fin surface markedly decreased the heat transfer rate of the conventional symmetric louvered fins in re-frosting cycles. On the other hand, the asymmetric louvered fins improved the drainage performance of the retention water, which enhanced the heat transfer rate. To identify the reason of the difference in drainage performance between two fin geometries, additional experiments were carried out with enlargement models. The improvement in drainage performance of the asymmetric fin design originated from the lowered surface tension between the fin surface and water droplet.

  4. Enhancement of heat transfer from a continuously moving porous fin exposed in convective–radiative environment

    International Nuclear Information System (INIS)

    Bhanja, Dipankar; Kundu, Balaram; Aziz, Abdul

    2014-01-01

    Highlights: • Analytical model for thermal analysis of moving porous fins. • Heat transfer from the fin surface due to convection and radiation. • For practical design aspects, optimization analysis was carried out. • Comparative study was made between the solid and porous moving fins. • Porous moving fin has more heat transfer ability than the stationary fin. - Abstract: In the present article, an exercise has been devoted to establish an analytical model for the determination of temperature distribution, fin efficiency and optimum design parameters of a porous moving fin which is losing heat by simultaneous convection and radiation to its surroundings. For the adaptation of this consideration, the governing equation becomes highly nonlinear. An analytical technique called Adomian decomposition method (ADM) is proposed for the solution methodology. The accuracy of the analytic solution is validated by using a numeric scheme called finite difference method. The results indicate that the numerical data and analytical approach are in agreement with each other. As the present study is an analytic, it is extended to the analysis for determination of optimum dimensions of said fin by satisfying either the maximization of rate of heat transfer for a given fin volume or by the minimization of fin volume for a desired heat transfer rate. The study is further extended to the porous fin in stationary condition and it is found that porous fin in moving condition transfers more heat than stationary condition. Investigation has also been made on solid moving fin to compare the outcomes of these parameters

  5. MobilED: a step backwards to look ahead

    CSIR Research Space (South Africa)

    Van Den Berg, M

    2008-10-01

    Full Text Available Psychology, 52(3), 476-485. Gamache, P. (2002). University Students as Creators of Personal Knowledge: an alternative epistemological view. Teaching in Higher Education, 7(3), 277. Garcia, L., & Quek, F. (1997). Qualitative research in information systems... Kenney & N. Nieveen (Eds.), Educational Design Research (pp. 52-67). London: Routledge. Reeves, T. C., Herrington, J., & Olivier, R. (2005). Design Research: A Socially Responsible Approach to Instructional Technology Research in Higher Education...

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  7. Laser Welding Of Finned Tubes Made Of Austenitic Steels

    Directory of Open Access Journals (Sweden)

    Stolecki M.

    2015-09-01

    Full Text Available This paper describes the technology of welding of finned tubes made of the X5CrNi1810 (1.4301 austenitic steel, developed at Energoinstal SA, allowing one to get high quality joints that meet the requirements of the classification societies (PN-EN 15614, and at the same time to significantly reduce the manufacturing costs. The authors described an automatic technological line equipped with a Trumph disc laser and a tube production technological process. To assess the quality of the joints, one performed metallographic examinations, hardness measurements and a technological attempt to rupture the fin. Analysis of the results proved that the laser-welded finned tubes were performed correctly and that the welded joints had shown no imperfections.

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

    KAUST Repository

    Fahad, Hossain M.

    2015-01-01

    By integrating 3-D nonplanar fins and 2-D ultrathin bodies, wavy FinFETs merge two formerly competing technologies on a silicon-on-insulator platform to deliver enhanced transistor performance compared with conventional trigate FinFETs with unprecedented levels of chip-area efficiency. This makes it suitable for ultralarge-scale integration high-performance logic at and beyond the 10-nm technology node.

  9. Investigation on flow and heat transfer characteristics in rectangular channel with drop-shaped pin fins

    Directory of Open Access Journals (Sweden)

    Fengming Wang

    2012-12-01

    Full Text Available The flow and heat transfer characteristics inside a rectangular channel embedded with pin fins were numerically and experimentally investigated. Several differently shaped pin fins (i.e., circular, elliptical, and drop-shaped with the same cross-sectional areas were compared in a staggered arrangement. The Reynolds number based on the obstructed section hydraulic diameter (defined as the ratio of the total wetted surface area to the open duct volume available for flow was varied from 4800 to 8200. The more streamlined drop-shaped pin fins were better at delaying or suppressing separation of the flow passing through them, which decreased the aerodynamic penalty compared to circular pin fins. The heat transfer enhancement of the drop-shaped pin fins was less than that of the circular pin fins. In terms of specific performance parameters, drop-shaped pin fins are a promising alternative configuration to circular pin fins.

  10. Multi-Mode Electric Actuator Dynamic Modelling for Missile Fin Control

    Directory of Open Access Journals (Sweden)

    Bhimashankar Gurav

    2017-06-01

    Full Text Available Linear first/second order fin direct current (DC actuator model approximations for missile applications are currently limited to angular position and angular velocity state variables. Furthermore, existing literature with detailed DC motor models is decoupled from the application of interest: tail controller missile lateral acceleration (LATAX performance. This paper aims to integrate a generic DC fin actuator model with dual-mode feedforward and feedback control for tail-controlled missiles in conjunction with the autopilot system design. Moreover, the characteristics of the actuator torque information in relation to the aerodynamic fin loading for given missile trim velocities are also provided. The novelty of this paper is the integration of the missile LATAX autopilot states and actuator states including the motor torque, position and angular velocity. The advantage of such an approach is the parametric analysis and suitability of the fin actuator in relation to the missile lateral acceleration dynamic behaviour.

  11. Exergo-economic analysis of finned tube for waste heat recovery including phase change heat transfer

    International Nuclear Information System (INIS)

    Wu, Shuang Ying; Jiu, Jing Rui; Xiao, Lan; Li, You Rong; Liu, Chao; Xu, Jin Liang

    2013-01-01

    In this paper, an exergo-economic criterion, i.e. the net profit per unit transferred heat load, is established from the perspective of exergy recovery to evaluate the performance of finned tube used in waste heat recovery. Also, the dimensionless exergy change number is introduced to investigate the effect of the flow (mechanical) exergy loss rate on the recovered thermal exergy. Selecting R245fa as a working fluid and exhaust flue gas as a heat source, the effects of the internal Reynolds number Re_i, the external Reynolds number Re_o , the unit cost of thermal exergy ε_q , the geometric parameter of finned tube η_oβ and the phase change temperature T_v etc. on the performance of finned tube are discussed in detail. The results show that the higher T_v and η_oβ, and lower Re_i may lead to the negligible flow(mechanical) exergy loss rate. There exists an optimal value of Re_i where the net profit per unit transferred heat load peaks, while the variations of Re_o, ε_q and T_v cause monotonic change of the net profit per unit transferred heat load. The phase change temperature exerts relatively greater influence on the exergo-economic performance of finned tube in comparison with other parameters. And there exists a critical phase change temperature, where the net profit per unit transferred heat load is equal to zero.

  12. FINCRUSH : a computer program for impact analysis of radioactive material transport cask with fins

    International Nuclear Information System (INIS)

    Ikushima, Takeshi

    1997-05-01

    In drop impact analyses for radioactive material transport cask with cooling fins, relationship between fin plastic deformation and fin energy absorption is used. This relationship was obtained by ORNL experiments and MONSER Co. in Canada. Based on ORNL experiments, a computer program FINCRUSH has been developed for rapid safety analysis of cask drop impact to obtain the maximum impact acceleration and the maximum fin deformation. Main features of FINCRUSH are as follows: (1) annulus fins on a cylindrical shell and plate fins on a disk can be treated, (2) it is capable of graphical representations for calculation results and fin absorption energy data and (3) not only main frame computer but also work stations (OS UNIX) and personal computer (OS Windows) are available for use of the FINCRUSH. In the paper, brief illustration of calculation method of FINCRUSH is presented. The second section presents comparisons between FINCRUSH and experimental results. The third section provides a use's guide for FINCRUSH. (author)

  13. FINCRUSH : a computer program for impact analysis of radioactive material transport cask with fins

    Energy Technology Data Exchange (ETDEWEB)

    Ikushima, Takeshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-05-01

    In drop impact analyses for radioactive material transport cask with cooling fins, relationship between fin plastic deformation and fin energy absorption is used. This relationship was obtained by ORNL experiments and MONSER Co. in Canada. Based on ORNL experiments, a computer program FINCRUSH has been developed for rapid safety analysis of cask drop impact to obtain the maximum impact acceleration and the maximum fin deformation. Main features of FINCRUSH are as follows: (1) annulus fins on a cylindrical shell and plate fins on a disk can be treated, (2) it is capable of graphical representations for calculation results and fin absorption energy data and (3) not only main frame computer but also work stations (OS UNIX) and personal computer (OS Windows) are available for use of the FINCRUSH. In the paper, brief illustration of calculation method of FINCRUSH is presented. The second section presents comparisons between FINCRUSH and experimental results. The third section provides a use`s guide for FINCRUSH. (author)

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

    International Nuclear Information System (INIS)

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

    2015-01-01

    The impact of process induced variation on the response of SOI FinFET to heavy ion irradiation is studied through 3-D TCAD simulation for the first time. When FinFET biased at OFF state configuration (V gs = 0, V ds = V dd ) is struck by a heavy ion, the drain collects ionizing charges under the electric field and a current pulse (single event transient, SET) is consequently formed. The results reveal that with the presence of line-edge roughness (LER), which is one of the major variation sources in nano-scale FinFETs, the device-to-device variation in terms of SET is observed. In this study, three types of LER are considered: type A has symmetric fin edges, type B has irrelevant fin edges and type C has parallel fin edges. The results show that type A devices have the largest SET variation while type C devices have the smallest variation. Further, the impact of the two main LER parameters, correlation length and root mean square amplitude, on SET variation is discussed as well. The results indicate that variation may be a concern in radiation effects with the down scaling of feature size. (paper)

  15. Determination of optimum fin profile for a zero-G capillary drained condenser

    Science.gov (United States)

    Mccormick, John A.; Valenzuela, Javier A.; Choudhury, Dipanker

    1990-01-01

    This paper presents the analytical formulation and numerical results for heat transfer in a high heat flux condenser that relies on capillary flow along shaped fins (Gregorig surfaces) and a drainage network embedded in the condenser walls. Results are shown for a variety of fin profile shapes in order to show the geometric trade-offs involved in seeking a maximum effective heat transfer coefficient for the fin. Predictions of the model show excellent agreement with previously reported measurements for steam. Based on this work, a profile has been selected for a 2 kW ammonia condenser currently under development for use in space. In that design the fin half width is 0.5 mm and the model predicts a heat transfer coefficient referred to the base of the fin of 9 W/sq cm deg C for a heat flux of 10/W sq cm at the base.

  16. Thermal performance of circular convective–radiative porous fins with different section shapes and materials

    International Nuclear Information System (INIS)

    Hatami, M.; Ganji, D.D.

    2013-01-01

    Graphical abstract: - Highlights: • LSM is an accurate technique for simulating heat transfer in circular porous fins. • Rectangular, convex, triangular and exponential variable sections are considered. • Radiation and convection from porous fin are considered. • Effects of material and geometry on heat transfer from fins are studied. - Abstract: In this study, heat transfer and temperature distribution equations for circular convective–radiative porous fins are presented. It’s assumed that the thickness of circular fins varies with radius so four different shapes, rectangular, convex, triangular and exponential, are considered. The heat transfer through porous media is simulated using passage velocity from the Darcy’s model. After deriving equation for each geometry, Least Square Method (LSM) and fourth order Runge–Kutta method (NUM) are applied for predicting the temperature distribution in the porous fins. The selected porous fin’s materials are Al, SiC, Cu and Si 3 N 4 . Results reveal that LSM has very effective and accurate in comparison with the numerical results. As a main outcome, Si 3 N 4 -exponential section fin has the maximum amount of transferred heat among other fins

  17. Optimum length of finned pipe for waste heat recovery

    International Nuclear Information System (INIS)

    Soeylemez, M.S.

    2008-01-01

    A thermoeconomic feasibility analysis is presented yielding a simple algebraic optimization formula for estimating the optimum length of a finned pipe that is used for waste heat recovery. A simple economic optimization method is used in the present study by combining it with an integrated overall heat balance method based on fin effectiveness for calculating the maximum savings from a waste heat recovery system

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

    Science.gov (United States)

    Meerbeek, Jonathan R.; Bettoli, Phillip William

    2012-01-01

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

  19. Characterising non-urgent users of the emergency department (ED): A retrospective analysis of routine ED data.

    Science.gov (United States)

    O'Keeffe, Colin; Mason, Suzanne; Jacques, Richard; Nicholl, Jon

    2018-01-01

    The pressures of patient demand on emergency departments (EDs) continue to be reported worldwide, with an associated negative impact on ED crowding and waiting times. It has also been reported that a proportion of attendances to EDs in different international systems could be managed in settings such as primary care. This study used routine ED data to define, measure and profile non-urgent ED attendances that were suitable for management in alternative, non-emergency settings. We undertook a retrospective analysis of three years of Hospital Episode and Statistics Accident Emergency (HES A&E) data for one large region in England, United Kingdom (April 1st 2011 to March 31st 2014). Data was collected on all adult (>16 years) ED attendances from each of the 19 EDs in the region. A validated process based definition of non-urgent attendance was refined for this study and applied to the data. Using summary statistics non-urgent attenders were examined by variables hypothesised to influence them as follows: age at arrival, time of day and day of week and mode of arrival. Odds ratios were calculated to compare non-urgent attenders between groups. There were 3,667,601 first time attendances to EDs, of which 554,564 were defined as non-urgent (15.1%). Non-urgent attendances were significantly more likely to present out of hours than in hours (OR = 1.19, 95% CI: 1.18 to 1.20, Paged 16-44) compared to those aged 45-64 (odds ratio: 1.42, 95% CI: 1.41 to 1.43, Puse the ED to obtain healthcare that could be provided in a less urgent setting and also more likely to do this out of hours. Alternative services are required to manage non-urgent demand, currently being borne by the ED and the ambulance service, particularly in out of hours.

  20. Plan de Mercadeo para una “FinTech”.

    OpenAIRE

    Escalante Lee, Maria Alejandra

    2016-01-01

    Las empresas deben contar con una misión clara, estableciendo los objetivos de apoyo, diseñando una cartera de negocio sólida y coordinar sus estrategias a futuro, con el fin de cumplir las metas propuestas para entregar e intercambiar ofertas que tienen valor para los consumidores, clientes, socios y la sociedad en general. El presente trabajo de grado tiene como objetivo proponer un plan de mercadeo para la empresa Comyno una FinTech ubicada en Frankfurt am Main, en Alemania. Este tiene ...

  1. Integral finned heater and cooler for stirling engines

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    Behbahani, Sanaz Bazaz; Tan, Xiaobo

    2016-05-04

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

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

    Science.gov (United States)

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

    2002-10-01

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

  4. The pelvic fin and girdle of Panderichthys and the origin of tetrapod locomotion.

    Science.gov (United States)

    Boisvert, Catherine A

    2005-12-22

    One of the most marked transformations in the vertebrate transition to land was that of fins to limbs. This transformation involved not only the generation of morphological novelties (digits, sacrum) but also a shift in locomotory dominance from the pectoral to the pelvic appendage. Despite its importance, the transformation from pelvic fin to hindlimb is the least studied and least well-documented part of this transformation, which is bracketed by the osteolepiform Eusthenopteron and the early tetrapods Ichthyostega and Acanthostega, but is not directly illuminated by any intermediate form. Panderichthys is the closest tetrapod relative currently represented by complete fossils, but its pelvic fin skeleton has not been described. Here, I present the only known articulated pelvic fin endoskeleton and associated partial pelvis of Panderichthys. The pelvic girdle is even less tetrapod-like than that of the osteolepiform Eusthenopteron, but the pelvic fin endoskeleton shares derived characteristics with basal tetrapods despite being more primitive than the pectoral fin of Panderichthys. The evolution of tetrapod locomotion appears to have passed through a stage of body-flexion propulsion, in which the pelvic fins played a relatively minor anchoring part, before the emergence of hindlimb-powered propulsion in the interval between Panderichthys and Acanthostega.

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

    Science.gov (United States)

    Mazzariol, Sandro; 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

    2016-02-01

    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.

  6. Thermal-Hydraulic Performance of a Corrugated Cooling Fin with Louvered Surfaces

    DEFF Research Database (Denmark)

    Sønderby, Simon Kaltoft; Hosseini, Seyed Mojtaba Mir; Rezaniakolaei, Alireza

    2017-01-01

    The main objective of the article is to investigate thermal-hydraulic performance of a corrugated cooling fin with louvered surfaces. The investigation is carried out using the fin geometry of one most commonly used liquid-to-air heat exchangers. The investigation was carried out by numerically...... simulating the airflow with louvered fin geometry. The simulation model was verified by comparing simulated j- and f-factors with the corresponding values of several experimental correlations. The j-factors deviated less than 10.7 % from two of the experimental correlations, whereas deviations ranging...

  7. EDS operator and control software

    International Nuclear Information System (INIS)

    Ott, L.L.

    1985-04-01

    The Enrichment Diagnostic System (EDS) was developed at Lawrence Livermore National Laboratory (LLNL) to acquire, display and analyze large quantities of transient data for a real-time Advanced Vapor Laser Isotope Separation (AVLIS) experiment. Major topics discussed in this paper are the EDS operator interface (SHELL) program, the data acquisition and analysis scheduling software, and the graphics software. The workstation concept used in EDS, the software used to configure a user's workstation, and the ownership and management of a diagnostic are described. An EDS diagnostic is a combination of hardware and software designed to study specific aspects of the process. Overall system performance is discussed from the standpoint of scheduling techniques, evaluation tools, optimization techniques, and program-to-program communication methods. EDS is based on a data driven design which keeps the need to modify software to a minimum. This design requires a fast and reliable data base management system. A third party data base management product, Berkeley Software System Database, written explicitly for HP1000's, is used for all EDS data bases. All graphics is done with an in-house graphics product, Device Independent Graphics Library (DIGLIB). Examples of devices supported by DIGLIB are: Versatec printer/plotters, Raster Technologies Graphic Display Controllers, and HP terminals (HP264x and HP262x). The benefits derived by using HP hardware and software as well as obstacles imposed by the HP environment are presented in relation to EDS development and implementation

  8. Experimental testing of the thermal performance of finned air coolers

    International Nuclear Information System (INIS)

    Imhof, A.; Keller, J.; Koelliker, A.

    1988-05-01

    Finned heat exchangers are often used as regenerators in heat recovery systems or as a heat source for heat pump installations. These exchangers are usually operating as air coolers. Heat is extracted from the air flowing through the heat exchanger. If the fin temperature lies below the dew point at the air inlet, water vapour may be condensed, increasing the thermal performance of the cooler. If the air/water heat exchanger is installed outdoors, the blower is usually mounted directly at the exchaner's case. In general this leads to non-ideal air flow conditions. For the sizing of such components the manufacturers dispose of design rules which are based either on theoretical models or on experiments using a uniform air stream. These rules which are mostly internal codes of the individual companies presumably do not take into account some non-ideal conditions such as an inhomogeneous air flow, a poorly sized blower or an increased pressure drop between the fins due to condensed water vapour. Moreover, these codes are possibly not sophisticated enough to enable a correct sizing of the products for any given condition of operation, especially in heat pumps operating under condensation conditions. Therfore, the Swiss Federal Institute for Reactor Research (EIR) carried out a research program dealing with the thermal performance of commercially available finned air coolers. The results give a strong evidence that the sizing of finned air coolers involving a phase change in one of the heat transfer fluids is not yet a procedure belonging to the common knowledge of most of the manufacturers. Moreover, the correct sizing of the blower is at least as important as the sizing of the finned exchanger itself. However, it is evident that there are companies on the Swiss market which use already reliable design tools. 25 refs., 81 figs., 12 tabs

  9. Fin Type Variation of Lionhead Strain Goldfish (Carassius auratus Offspring

    Directory of Open Access Journals (Sweden)

    M. Syaifudin

    2007-12-01

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

  10. Eddy current test of fin tubes for a heat exchanger

    International Nuclear Information System (INIS)

    KIm, Young Joo; Lee, Se Kyung; Chung, Min Hwa

    1992-01-01

    Eddy current probes were designed for the test of fin tubes. Fin tubes, often used for heat exchangers, have uneven outer and inner surfaces to enhance the heat emission. The surface roughness make it difficult to detect flaws employing eddy current test(ECT). In order to overcome the difficulties we performed two types of works, one is the delopment of ECT probes, and the other is the signal processing including fast Fourier transform and digital filtering. In the development of ECT probes, we adopted empirical design method. Our ECT probes for fin tubes are inside diameter type. And we are specially concerned about geometric features such as the widths of the coils composing an ECT probe. We fabricated four probes with various coil widths. Eddy current test was performed using those ECT probes on specimens with artificial flaws. After analyzing the output signals, we found that, in order for the effective testing, the width of a coil should be determined considering the pitch of the fins of a tube. And we also learned that the frequency filtering could improve the s/n ratio.

  11. Impact of line edge roughness on the performance of 14-nm FinFET: Device-circuit Co-design

    Science.gov (United States)

    Rathore, Rituraj Singh; Rana, Ashwani K.

    2018-01-01

    With the evolution of sub-20 nm FinFET technology, line edge roughness (LER) has been identified as a critical problem and may result in critical device parameter variation and performance limitation in the future VLSI circuit application. In the present work, an analytical model of fin-LER has been presented, which shows the impact of correlated and uncorrelated LER on FinFET structure. Further, the influence of correlated and uncorrelated fin- LER on all electrical performance parameters is thoroughly investigated using the three-dimensional (3-D) Technology Computer Aided Design (TCAD) simulations for 14-nm technology node. Moreover, the impact of all possible fin shapes on threshold voltage (VTH), drain induced barrier lowering (DIBL), on-current (ION), and off-current (IOFF) has been compared with the well calibrated rectangular FinFET structure. In addition, the influence of all possible fin geometries on the read stability of six-transistor (6-T) Static-Random-Access-Memory (SRAM) has been investigated. The study reveals that fin-LER plays a vital role as it directly governs the electrostatics of the FinFET structure. This has been found that there is a high degree of fluctuations in all performance parameters for uncorrelated fin-LER type FinFETs as compared to correlated fin-LER with respect to rectangular FinFET structure. This paper gives physical insight of FinFET design, especially in sub-20 nm technology nodes by concluding that the impact of LER on electrical parameters are minimum for correlated LER.

  12. edX e-learning course development

    CERN Document Server

    Gilbert, Matthew A

    2015-01-01

    If you are an educator creating a course for edX or a corporate trainer using Open edX for large-scale learning and development initiatives, then edX E-Learning Course Development is the ideal book for you.

  13. A successful application of homotopy perturbation method for efficiency and effectiveness assessment of longitudinal porous fins

    International Nuclear Information System (INIS)

    Cuce, Erdem; Cuce, Pinar Mert

    2015-01-01

    Highlights: • Homotopy perturbation method has been applied to porous fins. • Dimensionless efficiency and effectiveness expressions have been firstly developed. • Effects of porous and convection parameters on thermal analysis have been clarified. • Ratio of porous fin to solid fin heat transfer rate has been given for various cases. • Reliability and practicality of homotopy perturbation method has been illustrated. - Abstract: In our previous works, thermal performance of straight fins with both constant and temperature-dependent thermal conductivity has been investigated in detail and dimensionless analytical expressions of fin efficiency and fin effectiveness have been developed for the first time in literature via homotopy perturbation method. In this study, previous works have been extended to porous fins. Governing equations have been formulated by performing Darcy’s model. Dimensionless temperature distribution along the length of porous fin has been determined as a function of porosity and convection parameters. The ratio of porous fin to solid fin heat transfer rate has also been evaluated as a function of thermo-geometric fin parameter. The results have been compared with those of finite difference method for a specific case and an excellent agreement has been observed. The expressions developed are beneficial for thermal engineers for preliminary assessment of thermophysical systems instead of consuming time in heat conduction problems governed by strongly nonlinear differential equations

  14. Comparative study on thermal performance of natural draft cooling towers with finned shells

    International Nuclear Information System (INIS)

    Goodarzi, Mohsen

    2016-01-01

    The cooling efficiency of natural draft cooling towers under crosswind condition should be improved. In the present research work three different externally finned shells were considered for a typical natural draft cooling tower to investigate the cooling improvement. They were numerically simulated under normal and crosswind conditions. Numerical results show that twisting four fin plates over the tower shell along the 45 peripheral angle, could improve the cooling efficiency up to 6.5 %. Because of the periodic shape of the fin plates, the cooling efficiency of the cooling tower with finned shell is less sensitive to the change of wind.

  15. Comparative study on thermal performance of natural draft cooling towers with finned shells

    Energy Technology Data Exchange (ETDEWEB)

    Goodarzi, Mohsen [Bu-Ali Sina Univ., Hamedan (Iran, Islamic Republic of). Dept. of Mechanical Engineering

    2016-10-15

    The cooling efficiency of natural draft cooling towers under crosswind condition should be improved. In the present research work three different externally finned shells were considered for a typical natural draft cooling tower to investigate the cooling improvement. They were numerically simulated under normal and crosswind conditions. Numerical results show that twisting four fin plates over the tower shell along the 45 peripheral angle, could improve the cooling efficiency up to 6.5 %. Because of the periodic shape of the fin plates, the cooling efficiency of the cooling tower with finned shell is less sensitive to the change of wind.

  16. Performance measurement of plate fin heat exchanger by exploration: ANN, ANFIS, GA, and SA

    OpenAIRE

    A.K. Gupta; P. Kumar; R.K. Sahoo; A.K. Sahu; S.K. Sarangi

    2017-01-01

    An experimental work is conducted on counter flow plate fin compact heat exchanger using offset strip fin under different mass flow rates. The training, testing, and validation set of data has been collected by conducting experiments. Next, artificial neural network merged with Genetic Algorithm (GA) utilized to measure the performance of plate-fin compact heat exchanger. The main aim of present research is to measure the performance of plate-fin compact heat exchanger and to provide full exp...

  17. A Preliminary Examination of Loss of Control Eating Disorder (LOC-ED) in Middle Childhood

    Science.gov (United States)

    Matherne, Camden E.; Tanofsky-Kraff, Marian; Altschul, Anne M.; Shank, Lisa M.; Schvey, Natasha A.; Brady, Sheila M.; Galescu, Ovidiu; Demidowich, Andrew P.; Yanovski, Susan Z.; Yanovski, Jack A.

    2015-01-01

    Loss of Control Eating Disorder (LOC-ED) has been proposed as a diagnostic category for children 6–12y with binge-type eating. However, characteristics of youth with LOC-ED have not been examined. We tested the hypothesis that the proposed criteria for LOC-ED would identify children with greater adiposity, more disordered eating attitudes, and greater mood disturbance than those without LOC-ED. Participants were 251 youth (10.29y ± 1.54, 53.8% female, 57.8 % White, 35.5% Black, 2.0% Asian, 4.8% Hispanic, 53.0% overweight). Youth were interviewed regarding eating attitudes and behaviors, completed questionnaires to assess general psychopathology, and underwent measurements of body fat mass. Using previously proposed criteria for LOC-ED, children were classified as LOC-ED (n = 19), LOC in the absence of the full disorder (subLOC, n = 33), and youth not reporting LOC (noLOC, n = 199). LOC-ED youth had higher BMIz (p = 0.001) and adiposity (p = 0.003) and reported greater disordered eating concerns (p eating attitudes (p = 0.02). SubLOC youth had greater disordered eating concerns (p eating cognitions and anthropometric measures compared to youth without LOC-ED. Longitudinal studies are needed to determine if those with LOC-ED are at particularly increased risk for progression of disordered eating and excess weight gain. PMID:25913008

  18. A preliminary examination of Loss of Control Eating Disorder (LOC-ED) in middle childhood.

    Science.gov (United States)

    Matherne, Camden E; Tanofsky-Kraff, Marian; Altschul, Anne M; Shank, Lisa M; Schvey, Natasha A; Brady, Sheila M; Galescu, Ovidiu; Demidowich, Andrew P; Yanovski, Susan Z; Yanovski, Jack A

    2015-08-01

    Loss of Control Eating Disorder (LOC-ED) has been proposed as a diagnostic category for children 6-12years with binge-type eating. However, characteristics of youth with LOC-ED have not been examined. We tested the hypothesis that the proposed criteria for LOC-ED would identify children with greater adiposity, more disordered eating attitudes, and greater mood disturbance than those without LOC-ED. Participants were 251 youth (10.29years±1.54, 53.8% female, 57.8% White, 35.5% Black, 2.0% Asian, 4.8% Hispanic, 53.0% overweight). Youth were interviewed regarding eating attitudes and behaviors, completed questionnaires to assess general psychopathology, and underwent measurements of body fat mass. Using previously proposed criteria for LOC-ED, children were classified as LOC-ED (n=19), LOC in the absence of the full disorder (subLOC, n=33), and youth not reporting LOC (noLOC, n=199). LOC-ED youth had higher BMIz (p=0.001) and adiposity (p=0.003) and reported greater disordered eating concerns (pdisordered eating attitudes (p=0.02). SubLOC youth had greater disordered eating concerns (pdisordered eating cognitions and anthropometric measures compared to youth without LOC-ED. Longitudinal studies are needed to determine if those with LOC-ED are at particularly increased risk for progression of disordered eating and excess weight gain. Published by Elsevier Ltd.

  19. Feasibility Study to Reduce Thermal Resistance of Finned Containment Wall in Simplified OPR1000

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Hwi; Kang, Hie Chan [Kunsan National University, Gunsan (Korea, Republic of); Noh, Hyung Gyun [Pohang University, Pohang (Korea, Republic of)

    2016-05-15

    This concept is securing of cooling capability by using finned containment itself, it could be another alternative for achieving decompression of containment as heat sink. The objective of this study is a feasibility test to estimate the heat transfer performance from the finned containment wall in case of OPR1000. The commercial code, ANSYS CFX 16 was used in this work. The number of grids is about 1.8 million. Therefore, 250mm rebar affects more considerable than that of 50mm to the temperature distribution. For this reasons, temperature distribution of z-axis direction was showed significant changes in (c). The heat transfer in three types of containment was 267.6W, 265.2W and 307.8W, respectively. The Type B case increased up to 15% of heat transfer than the baseline containment building. Three different types of containment wall were tested by numerical simulation to understand the cooling performance of finned containment wall. We can conclude as follows: For the finned containment wall type A that fins are installed inside and outside with the same rebar configuration of conventional containment building, the heat transfer is almost the same as conventional containment wall. The finned containment wall type B that volume fraction of rebar is increased transfer the heat 15% more compared with conventional one. The cross-sectional area or volume fraction of the rebar to attach fin is important to enhance the heat transfer. The fin efficiency of the fin is very low as 3.1% in the present cases.

  20. Role of fin material and nanofluid in performance enhancement of automobile radiator

    Science.gov (United States)

    Jadar, Raju; Shashishekar, K. S.; Channa Keshava Naik, N.

    2018-04-01

    An effective cooling system can avoid engine and its components from overheating and helps in achieving optimum engine performance. This work deals with the fabrication and performance evaluation of an automobile radiator with i) Aluminum fins and ii) Al-MWCNT fins using 0.1 w/v% f-MWCNT nanofluid. F-MWCNT nanoparticles in the base fluid improves the rate of heat transfer in an automobile radiator integrated with Al-MWCNT fins. The enhancement of heat transfer mainly depends on the quantity of F-MWCNT nanoparticles added to the host fluid. During the study it was found that at a low weight by volume concentration of nanofluid the heat transfer enhancement of 8% was achieved using Al-MWCNT fins compared to base fluid.

  1. Inverse analysis of a rectangular fin using the lattice Boltzmann method

    International Nuclear Information System (INIS)

    Bamdad, Keivan; Ashorynejad, Hamid Reza

    2015-01-01

    Highlights: • Lattice Boltzmann method is used to study a transient conductive-convective fin. • LBM and Conjugate Gradient Method (CGM) are used to solve an inverse problem in fins. • LBM–ACGM estimates the unknown boundary conditions of fins accurately. • The accuracy and CPU time of LBM–ACGM are compared to IFDM–ACGM. • LBM–ACGM could be a good alternative for the conventional inverse methods. - Abstract: Inverse methods have many applications in determining unknown variables in heat transfer problems when direct measurements are impossible. As most common inverse methods are iterative and time consuming especially for complex geometries, developing more efficient methods seems necessary. In this paper, a direct transient conduction–convection heat transfer problem (fin) under several boundary conditions was solved by using lattice Boltzmann method (LBM), and then the results were successfully validated against both the finite difference method and analytical solution. Then, in the inverse problem both unknown base temperatures and heat fluxes in the rectangular fin were estimated by combining the adjoint conjugate gradient method (ACGM) and LBM. A close agreement between the exact values and estimated results confirmed the validity and accuracy of the ACGM–LBM. To compare the calculation time of ACGM–LBM, the inverse problem was solved by implicit finite difference methods as well. This comparison proved that the ACGM–LBM was an accurate and fast method to determine unknown thermal boundary conditions in transient conduction–convection heat transfer problems. The findings can efficiently determine the unknown variables in fins when a desired temperature distribution is available

  2. Velocity Deficits in the Wake of Model Lemon Shark Dorsal Fins Measured with Particle Image Velocimetry

    Science.gov (United States)

    Terry, K. N.; Turner, V.; Hackett, E.

    2017-12-01

    Aquatic animals' morphology provides inspiration for human technological developments, as their bodies have evolved and become adapted for efficient swimming. Lemon sharks exhibit a uniquely large second dorsal fin that is nearly the same size as the first fin, the hydrodynamic role of which is unknown. This experimental study looks at the drag forces on a scale model of the Lemon shark's unique two-fin configuration in comparison to drag forces on a more typical one-fin configuration. The experiments were performed in a recirculating water flume, where the wakes behind the scale models are measured using particle image velocimetry. The experiments are performed at three different flow speeds for both fin configurations. The measured instantaneous 2D distributions of the streamwise and wall-normal velocity components are ensemble averaged to generate streamwise velocity vertical profiles. In addition, velocity deficit profiles are computed from the difference between these mean streamwise velocity profiles and the free stream velocity, which is computed based on measured flow rates during the experiments. Results show that the mean velocities behind the fin and near the fin tip are smallest and increase as the streamwise distance from the fin tip increases. The magnitude of velocity deficits increases with increasing flow speed for both fin configurations, but at all flow speeds, the two-fin configurations generate larger velocity deficits than the one-fin configurations. Because the velocity deficit is directly proportional to the drag force, these results suggest that the two-fin configuration produces more drag.

  3. PREFACE: EDS2010 Preface

    Science.gov (United States)

    Heggie, Malcolm I.

    2011-03-01

    The biennial international conference on Extended Defects in Semiconductors started in 1978 with a meeting in Hünfeld, Germany. Subsequent meetings rotated between Poland, France, Great Britain, Germany, Russia and Italy, culminating in EDS2004 in Chernogolovka, EDS2006 in Halle and EDS2008 in Poitiers. EDS2010 was held at the University of Sussex at Brighton, UK from September 19th to 24th. An extension of the tabulation of this history, which first appeared on the EDS2006 website, is given in the attached PDF. It is with sadness that we note one of the founders of the series, Prof. Dr Helmut Alexander, passed away on 3 December 2009 and we were proud to dedicate EDS2010 to his memory. It has become a tradition to make an award in his name, and this year it was made to Ivan Isacov for his poster "Electrical levels of dislocation networks in p- and n-type silicon". A short and warm celebration of Prof. Dr Alexander's life by his friends and colleagues, Prof. Drs Helmut Gottschalk, Eicke Weber and Wolfgang Schröter, is included in this volume. The conference was a forum for the state-of-the-art of investigation and modelling of extended defects in semiconductors. Scientists from universities, research institutes and industry made contributions to a deeper understanding of extended defects, their interaction with point defects and their role in the development of semiconductor technology. The remit of the conference included extended defects, nanostructures, nanoparticles, quantum dots and interfaces within semiconducting materials ranging from narrow to wide band gaps, including graphene-derived materials and diamond. Scientific interests range from defect geometry, electronic structure, dynamics, spectroscopy, microscopy, reactions and chemistry to introduction mechanisms, such as implantation and strained layers and the operation of devices such as integrated circuits, heterostructures, and solar cells. The organisers were confronted with a long period between

  4. Two-dimensional nonlinear transient heat transfer analysis of variable section pin fins

    Energy Technology Data Exchange (ETDEWEB)

    Malekzadeh, P. [Department of Mechanical Engineering, School of Engineering, Persian Gulf University, Boushehr 75168 (Iran); Rahideh, H. [Department of Chemical Engineering, School of Engineering, Persian Gulf University, Boushehr 75168 (Iran)

    2009-04-15

    The two-dimensional nonlinear transient heat transfer analysis of variable cross section pin-fins is studied using the incremental differential quadrature method (IDQM) as a simple, accurate, and computationally efficient numerical tool. The formulations are general so that it can easily be used for arbitrary continuously varying cross section pin fins with the spatial-temperature dependent thermal parameters. On all external surfaces of the pin fin, the convective-radiative condition is considered. The effects of two different types of boundary conditions at the base of pin fin are investigated: time and spatial dependent temperature, and the convection heat transfer. The thermal conductivity of the pin fin is assumed to vary as a linear function of the temperature. The accuracy of the method is demonstrated by comparing its results with those generated by finite difference method. It is shown that using few grid points, results in excellent agreements with those of FDM are obtained. Less computational efforts of the method with respect to finite difference method is shown. (author)

  5. A comparison of pectoral fin contact between two different wild dolphin populations

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2014-07-01

    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.

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

    Science.gov (United States)

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

    2014-06-01

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

  8. EdF: high tension(s) metamorphosis

    International Nuclear Information System (INIS)

    Roussely, F.; Arnoux, P.; Baritault, A.; Alto, P.; Castets, C.; Secondi, J.

    2003-01-01

    Electricite de France, the French electric utility, has to face a formidable mutation. The deregulation of the power market will lead to a social, commercial, judicial, financial and international 'big-bang'. The company has been weakened by disappointing results and by an embarrassing running into debts. This dossier analyzes the consequences of the deregulation of the French power market on the future evolution of EdF. It includes the analysis made by a French economist, E. Cohen, an interview and a portrait of F. Roussely, head of EdF, a presentation of Easenergy, a start-up of EdF which makes partnerships with US energy-related companies, the worries of EdF's employees and the redistribution of the syndicates power inside the company, the controversy around EdF's 2002 results and the points that remained in the shade, EdF's European competitors and the progressive opening of the French power market, EDF's production tool and its availability (58 nuclear reactors, 538 hydroelectric power plants and 26 thermal power plants), the costly foreign markets strategy of EdF and the under-capitalization of the company. (J.S.)

  9. 3-D NUMERICAL STUDY AND COMPARISON OF ECCENTRIC AND CONCENTRIC ANNULAR-FINNED TUBE HEAT EXCHANGERS

    Directory of Open Access Journals (Sweden)

    FAROUK TAHROUR

    2015-11-01

    Full Text Available The use of 3-D computational fluid dynamics (CFD is proposed to simulate the conjugate conduction-convection of heat transfer problems in eccentric annularfinned tube heat exchangers. The numerical simulation results allow us to evaluate the heat transfer coefficient over fin surfaces, the fin efficiency and the pressure drop. The aim of the present paper is to determine the optimum tube position in the circular fin that maximizes heat dissipation and minimizes pressure drop. In addition, this study analyzes the effects of fin spacing and fin tube diameter on heat transfer and flow characteristics for a range of Reynolds numbers, 4500≤Re≤22500. A satisfactory qualitative and quantitative agreement was obtained between the numerical predictions and the results published in the literature. For small fin spacings, the eccentric annular finned tube is more efficient than the concentric one. Among the cases examined, the average heat transfer coefficient of the eccentric annular-finned tube, for a tube shift St =12 mm and a Reynolds number Re = 9923, was 7.61% greater than that of the concentric one. This gain is associated with a 43.09% reduction in pressure drop.

  10. Flexible nanoscale high-performance FinFETs

    KAUST Repository

    Sevilla, Galo T.; Ghoneim, Mohamed T.; Fahad, Hossain M.; Rojas, Jhonathan Prieto; Hussain, Aftab M.; Hussain, Muhammad Mustafa

    2014-01-01

    With the emergence of the Internet of Things (IoT), flexible high-performance nanoscale electronics are more desired. At the moment, FinFET is the most advanced transistor architecture used in the state-of-the-art microprocessors. Therefore, we show

  11. Numerical Study of Compact Plate-Fin Heat Exchanger for Rotary-Vane Gas Refrigeration Machine

    Directory of Open Access Journals (Sweden)

    V. V. Trandafilov

    2017-10-01

    Full Text Available Plate-fin heat exchangers are widely used in refrigeration technique. They are popular because of their compactness and excellent heat transfer performance. Here we present a numerical model for the development, research and optimization of a plate-fin heat exchanger for a rotary-vane gas refrigeration machine. The method of analysis by graphic method of plate - fin heat exchanger is proposed. The model describes the effects of secondary parameters such as axial thermal conductivity through a metal matrix of the heat exchanger. The influence of geometric parameters and heat transfer coefficient is studied. Graphs of dependences of length, efficiency of a fin and pressure drop in a heat exchanger on the thickness of the fin and the number of fins per meter are obtained. To analyze the results of numerical simulation, the heat exchanger was designed in the Aspen HYSYS program. The simulation results show that the total deviation from the proposed numerical model is not more than 15%. 

  12. Optimization analysis of convective–radiative longitudinal fins with temperature-dependent properties and different section shapes and materials

    International Nuclear Information System (INIS)

    Mosayebidorcheh, S.; Hatami, M.; Mosayebidorcheh, T.; Ganji, D.D.

    2015-01-01

    Graphical abstract: Temperature distribution along the fins obtained for different material and section shapes. - Highlights: • The steady state thermal analysis of longitudinal fins is presented. • The properties of fins are assumed as a function of temperature. • The rectangular, convex, triangular and concave profiles are considered for fin shape. • Least Square Method (LSM) is used for solving the governing equation. • Thermal optimization of fin geometry is presented based on maximum value of heat transfer. - Abstract: The main aim of this study is to obtain an optimum design point for fin geometry, so that heat transfer rate reaches to a maximum value in a constant fin volume. Effect of fin thicknesses ratio (τ), convection coefficient power index (m), profile power parameter (n), base thickness (δ) and fin material are evaluated in the fin optimization point for heat transfer rate, effectiveness and efficiency. It’s assumed that the thickness of longitudinal fins varies with length in a special profile, so four different shapes (rectangular, convex, triangular and concave) are considered. In present study, temperature-dependent heat generation, convection and radiation are considered and an analytical technique based on the least square method is proposed for the solution methodology. Results show that by increasing the fin thicknesses ratio, maximum heat transfer rate decreases and Copper among the other materials has the most heat transfer rate in a constant volume.

  13. Swimming performance of a bio-inspired robotic vessel with undulating fin propulsion.

    Science.gov (United States)

    Liu, Hanlin; Curet, Oscar M

    2018-06-18

    Undulatory fin propulsion exhibits high degree of maneuver control -- an ideal for underwater vessels exploring complex environments. In this work, we developed and tested a self-contained, free-swimming robot with a single undulating fin running along the length of the robot, which controls both forward motion and directional maneuvers. We successfully replicated several maneuvers including forward swimming, reversed motion, diving, station-keeping and vertical swimming. For each maneuver, a series of experiments were performed as a function of fin frequency, wavelength and traveling wave direction to measure swimming velocities, orientation angles and mean power consumption. In addition, three-dimensional flow fields were measured during forward swimming and station-keeping using volumetric particle image velocimetry (PIV). The efficiency for forward swimming was compared using three metrics: cost of transport, wave efficiency and Strouhal number. The results indicate that the cost of transport exhibits a V-shape trend with the minimum value at low swimming velocity. The robot can reach optimal wave efficiency and locomotor performance at a range of 0.2 to 0.4 St. Volumetric PIV data reveal the shed of vortex tubes generated by the fin during forward swimming and station keeping. For forward swimming, a series of vortex tubes are shed off the fin edge with a lateral and downward direction with respect to the longitudinal axis of the fin. For station keeping, flow measurements suggest that the vortex tubes are shed at the mid-section of the fin while the posterior and anterior segment of the vortex stay attached to the fin. These results agree with the previous vortex structures based on simulations and 2D PIV. The further development of this vessel with high maneuverability and station keeping performance can be used for oceanography, coastal exploration, defense, oil industry and other marine industries where operations are unsafe or impractical for divers or

  14. A comparison of the analysis of REE-bearing phosphates by standardless EDS and standardised EDS and WDS

    International Nuclear Information System (INIS)

    Griffin, B.J.; Hancock, R.C.; Trautman, R.L.

    2002-01-01

    Full text: Current generation energy dispersive X-ray analysis systems EDS on SEM are user-friendly with 'simple' software interfaces. Minimal training is considered necessary for operation. One aim of this study was to test this hypothesis. The second aim, as a part of other studies, was to compare the results of the x-ray microanalysis of a suite of rare earth element (REE) bearing standard glasses and also a suite of rare earth element (REE) bearing phosphate mineral grains using different analytical systems. Our results from the same sample mounts have been obtained using three analytical systems: an Oxford Instruments ISIS EDS on a JEOL 6400 SEM, a Noran Voyager EDS on a JEOL 6400 SEM and a Moran Scientific WDS package on a JEOL 6400 SEM. A total of forty nine natural mineral grains have been analysed for twenty-two elements, including the REE, Ca, P and F (where possible) by each analytical system. Additional analyses were obtained from simple REE-bearing glass standards, each containing only one REE at around 11 wt %. The natural mineral grain results obtained from the different analytical systems show a number of significant variations. The two EDS datasets are comparable in terms of total REE but generally are a factor of two less than the WDS dataset. Internally the EDS datasets differ in that one set shows consistently a strong negative yttrium oxide result (typically -1 wt %) due to an excessive correction for a strong phosphorus overlap (Ka on La) whereas the second dataset shows the reverse with typically 1 wt % yttrium oxide reported, as a result of inadequate correction of the phosphorus overlap. Major elements are comparable between the standard-based datasets but not with the standardless dataset although all show similar reproducibility. The standard glass results are more coherent and consistent, as would be expected from the simpler composition and higher abundances. One clear outcome from these data is that complex compositions where

  15. The stress characteristics of plate-fin structures at the different operation parameters of LNG heat exchanger

    Directory of Open Access Journals (Sweden)

    Ma Hongqiang

    2018-01-01

    Full Text Available In this paper, the stresses of plate-fin structures at the different operation parameters were analyzed in actual operation process of LNG plate-fin heat exchanger based on finite element method and thermal elastic theory. Stress characteristics of plate-fin structures were investigated at the different operation parameters of that. The results show that the structural failure of plate-fin structures is mainly induced by the maximum shear stress at the brazing filler metal layer between plate and fin while by the maximum normal stress in the region of brazed joint near the fin side. And a crack would initiate in brazed joint near the fin side. The maximum normal stress is also main factor to result in the structural failure of plate-fin structures at the different temperature difference (between Natural Gas (NG and Mixture Refrigerant (MR, MR temperature and NG pressure of LNG heat exchanger. At the same time, the peak stresses obviously increase as the temperature difference, MR temperature and NG pressure increase. These results will provide some constructive instructions in the safe operation of LNG plate-fin heat exchanger in a large-scale LNG cold-box.

  16. Assessment of in vitro antifungal activity of preparation ''fin Candimis'' against Candida strains

    Directory of Open Access Journals (Sweden)

    Anna Głowacka

    2013-12-01

    Full Text Available The aim of the study was to assess the antifungal activity of preparation „fin Candimis” (oregano essential oil against yeast-like strains belonging to the genus Candida. During the investigation, there were used up nine Candida albicans strains and ten C. glabrata strains isolated from different clinical material, along with one C. albicans demonstration strain ATCC 90028. The oregano essential oil, utilized in the study, was obtained from fresh leaves of Origanum vulgare L. and bore a trade name „fin Candimis”. According to data yielded by its manufacturer, concentration of pure oregano essential oil in preparation „fin Candimis” totals up to 210 mg/ml. The susceptibility of the Candida strains to preparation „fin Candimis” was assessed by means of the disc-diffusion method, upon the Sabouraud solid medium (after a 24-hour incubation of the cultures at temperature of 37 degrees centigrade; the oregano essential oil had been diluted in 1 ml of DMSO, according to the geometrical progression. A measure of the antifungal activity of preparation „fin Candimis” was the minimal inhibitory concentration (MIC, in terms of the fungus growth. Preparation „fin Candimis” is capable of being applied in the prevention and treatment of candidiasis – alone, or as a natural adjunctive agent. The C. albicans strains are more susceptible to preparation „fin Candimis” in comparison to the C. glabrata ones.

  17. Thermal management of electronics using phase change material based pin fin heat sinks

    International Nuclear Information System (INIS)

    Baby, R; Balaji, C

    2012-01-01

    This paper reports the results of an experimental study carried out to explore the thermal characteristics of phase change material based heat sinks for electronic equipment cooling. The phase change material (PCM) used in this study is n – eicosane. All heat sinks used in the present study are made of aluminium with dimensions of 80 × 62 mm 2 base with a height of 25 mm. Pin fins acts as the thermal conductivity enhancer (TCE) to improve the distribution of heat more uniformly as the thermal conductivity of the PCM is very low. A total of three different pin fin heat sink geometries with 33, 72 and 120 pin fins filled with phase change materials giving rise to 4%, 9% and 15% volume fractions of the TCE respectively were experimentally investigated. Baseline comparisons are done with a heat sink filled with PCM, without any fin. Studies are conducted for heat sinks on which a uniform heat load is applied at the bottom for the finned and unfinned cases. The effect of pin fins of different volume fractions with power levels ranging from 4 to 8 W corresponding to a heat flux range of 1. 59 to 3.17 kW/m 2 , was explored in this paper. The volume fraction of the PCM (PCM volume / (Total volume – fin volume)) is also varied as 0. 3, 0.6 and 1 to determine the effect of PCM volume on the overall performance of the electronic equipment.

  18. Performance improvement of the finned passive PVT system using reflectors like removable insulation covers

    International Nuclear Information System (INIS)

    Ziapour, Behrooz M.; Palideh, Vahid; Mokhtari, Farhad

    2016-01-01

    Highlights: • A passive PVT system means the combination of a PV panel and a compact solar water heater. • Comparative study was done on performance characteristics in passive and hybrid PVT systems. • Reflectors effects on performance of a finned passive PVT system were numerically studied. • Results show that the finned passive PVT system has higher performance than the hybrid type. • Reflectors reduce the night heat losses and increase the solar radiation rate on PVT system. - Abstract: A passive photovoltaic–thermal system (PVT) is the combination of a photovoltaic (PV) panel and a compact solar water heater for co-generation of heat and electricity. This system bears considerable heat losses to ambient, particularly at noncollection times. One simple way to overcome this problem is to use a removable insulation cover on the collector's outer glazing. In this paper, the effects of the reflectors on day and night performance of a finned passive PVT system were numerically studied. At nonenergy collection time, the reflectors can turn and cover the collector cover glass as a nonconductor material. Simulation results showed that the reflectors reduce the night heat losses and increase the solar radiation rate on the absorber plate. The use of removable insulation reflectors resulted to saving extra sensibly thermal energy. Also, the solar cells power generation (P_s_c), in the case of reflectors installed, was reinforced.

  19. Burnout in the boiling of water and freon-113 on tubes with annular fins

    International Nuclear Information System (INIS)

    Rubin, I.R.; Pul'kin, I.N.; Roizen, L.I.

    1986-01-01

    This paper presents the results of numerical calculations of burnout heat flux associated with the boiling of Freon-113 and water on an annular fin of constant thickness which have been approximated by simple analytical relations. These are used to calculate the critical burnout parameters of tubes with an annular fin assembly. The calculated data may be used for the analysis of tubes with an annular fin assembly over a wide range of variation of the thermophysical properties of the material and geometrical parameters of the fin assembly

  20. Structure optimization and performance experiments of a solar-powered finned-tube adsorption refrigeration system

    International Nuclear Information System (INIS)

    Ji, Xu; Li, Ming; Fan, Jieqing; Zhang, Peng; Luo, Bin; Wang, Liuling

    2014-01-01

    Highlights: • New-structure finned-tube adsorption bed for enhancing heat and mass transfer. • Temperatures on different parts of the adsorption tubes differ little. • Maximum COP of 0.122 and maximum daily ice-making of 6.5 kg are achieved by experiments. • Cooling efficiency of system with valve control higher than that without valve control. - Abstract: A large-diameter aluminum-alloy finned-tube absorbent bed collector was designed and optimized by enhancing the heat and mass transfer in the collector. The collection efficiency of the adsorbent bed collector was between 31.64% and 42.7%, and the temperature distribution in the absorbent bed was relatively uniform, beneficial to adsorption/desorption of the adsorbate in the absorbent bed. A solar-powered solid adsorption refrigeration system with the finned-tube absorbent bed collector was built. Some experiments corresponding to the adsorption/desorption process with and without a valve control were conducted in four typical weather conditions: sunny with clear sky, sunny with partly cloudy sky, cloudy sky and overcast sky. Activated carbon–methanol was utilized as the working pair for adsorption refrigeration in the experiments. The experiments achieved the maximum COP of 0.122 and the maximum daily ice-making of 6.5 kg. Under the weather conditions of sunny with clear sky, sunny with partly cloudy sky, and cloudy sky, ice-making phenomenon were observed. Even in the overcast-sky weather condition, the cooling efficiency of the system still reached 0.039 when the total solar radiation was 11.51 MJ. The cooling efficiency of the solar-powered adsorption refrigeration system with a valve control in the adsorption/desorption process was significantly higher than that without a valve control

  1. Small Tails Tell Tall Tales--Intra-Individual Variation in the Stable Isotope Values of Fish Fin.

    Directory of Open Access Journals (Sweden)

    Brian Hayden

    Full Text Available Fish fin is a widely used, non-lethal sample material in studies using stable isotopes to assess the ecology of fishes. However, fish fin is composed of two distinct tissues (ray and membrane which may have different stable isotope values and are not homogeneously distributed within a fin. As such, estimates of the stable isotope values of a fish may vary according to the section of fin sampled.To assess the magnitude of this variation, we analysed carbon (δ13C, nitrogen (δ15N, hydrogen (δ2H and oxygen (δ18O stable isotopes of caudal fin from juvenile, riverine stages of Atlantic salmon (Salmo salar and brown trout (Salmo trutta. Individual fins were sub-sectioned into tip, mid and base, of which a further subset were divided into ray and membrane.Isotope variation between fin sections, evident in all four elements, was primarily related to differences between ray and membrane. Base sections were13C depleted relative to tip (~1‰ with equivalent variation evident between ray and membrane. A similar trend was evident in δ2H, though the degree of variation was far greater (~10‰. Base and ray sections were 18O enriched (~2‰ relative to tip and membrane, respectively. Ray and membrane sections displayed longitudinal variation in 15N mirroring that of composite fin (~1‰, indicating that variation in15N values was likely related to ontogenetic variation.To account for the effects of intra-fin variability in stable isotope analyses we suggest that researchers sampling fish fin, in increasing priority, 1 also analyse muscle (or liver tissue from a subsample of fish to calibrate their data, or 2 standardize sampling by selecting tissue only from the extreme tip of a fin, or 3 homogenize fins prior to analysis.

  2. Cycle performance of alternative refrigerants for domestic air-conditioning system based on a small finned tube heat exchanger

    International Nuclear Information System (INIS)

    Cheng, Song; Wang, Shuangfeng; Liu, Zhongmin

    2014-01-01

    In order to find alternative refrigerants which exhibit both favorable cycle performance and environmental friendliness, R32 and R290 were utilized to contrast to R22 and R410A as substitutes in the present study. The experiments were conducted with a 5 mm finned tube heat exchanger based on the enthalpy method in a small split household air conditioner. The results showed that in nominal cooling conditions, the COP R of R32 and R290 were 26.8% and 20.4% higher than R22, 7.3% and 2.1% higher than R410A. And in nominal heating conditions, the COP HR of R32 and R290 were both 11.0% higher than R22, 5.3% higher than R410A. The systems with R290 and R32 have similar capacities to that with R22 and R410A in heating mode, but a relatively huge difference of capacities in cooling mode. In consideration of charge amount, R290 could be considered as the most superior alternative refrigerant in air conditioners with the small finned tube heat exchanger. - Highlights: •Comparisons are made in the air conditioner system based on 5 mm tube fin heat exchanger. •The R22 system has a similar performance to others in heating mode while a huge difference in cooling mode. •The optimal charge of R290 is reduced with nearly no decline in the capacity and COP. •SLHX is attached to the system of R290 and successfully promote safety and capacity. •Heat loads are taken into account to evaluate the advantages and disadvantages of R290 and R32

  3. Development of plate-fin heat exchanger for intermediate heat exchanger of high-temperature gas cooled reactor. Fabrication process, high-temperature strength and creep-fatigue life prediction of plate-fin structure made of Hastelloy X

    International Nuclear Information System (INIS)

    Mizokami, Yorikata; Igari, Toshihide; Nakashima, Keiichi; Kawashima, Fumiko; Sakakibara, Noriyuki; Kishikawa, Ryouji; Tanihira, Masanori

    2010-01-01

    The helium/helium heat exchanger (i.e., intermediate heat exchanger: IHX) of a high-temperature gas-cooled reactor (HTGR) system with nuclear heat applications is installed between a primary system and a secondary system. IHX is operated at the highest temperature of 950degC and has a high capacity of up to 600 MWt. A plate-fin-type heat exchanger is the most suitable for IHX to improve construction cost. The purpose of this study is to develop an ultrafine plate-fin-type heat exchanger with a finer pitch fin than a conventional technology. In the first step, fabrication conditions of the ultrafine plate fin were optimized by press tests. In the second step, a brazing material was selected from several candidates through brazing tests of rods, and brazing conditions were optimized for plate-fin structures. In the third step, tensile strength, creep rupture, fatigue, and creep-fatigue tests were performed as typical strength tests for plate-fin structures. The obtained data were compared with those of the base metal and plate-fin element fabricated from SUS316. Finally, the accuracy of the creep-fatigue life prediction using both the linear cumulative damage rule and the equivalent homogeneous solid method was confirmed through the evaluation of creep-fatigue test results of plate-fin structures. (author)

  4. Understanding Fish Linear Acceleration Using an Undulatory Biorobotic Model with Soft Fluidic Elastomer Actuated Morphing Median Fins.

    Science.gov (United States)

    Wen, Li; Ren, Ziyu; Di Santo, Valentina; Hu, Kainan; Yuan, Tao; Wang, Tianmiao; Lauder, George V

    2018-04-10

    Although linear accelerations are an important common component of the diversity of fish locomotor behaviors, acceleration is one of the least-understood aspects of propulsion. Analysis of acceleration behavior in fishes with both spiny and soft-rayed median fins demonstrates that fin area is actively modulated when fish accelerate. We implemented an undulatory biomimetic robotic fish model with median fins manufactured using multimaterial three-dimensional printing-a spiny-rayed dorsal fin, soft-rayed dorsal/anal fins, and a caudal fin-whose stiffnesses span three orders of magnitude. We used an array of fluidic elastomeric soft actuators to mimic the dorsal/anal inclinator and erector/depressor muscles of fish, which allowed the soft fins to be erected or folded within 0.3 s. We experimentally show that the biomimetic soft dorsal/anal fin can withstand external loading. We found that erecting the soft dorsal/anal fins significantly enhanced the linear acceleration rate, up to 32.5% over the folded fin state. Surprisingly, even though the projected area of the body (in the lateral plane) increased 16.9% when the median fins were erected, the magnitude of the side force oscillation decreased by 24.8%, which may have led to significantly less side-to-side sway in the robotic swimmer. Visualization of fluid flow in the wake of median fins reveals that during linear acceleration, the soft dorsal fin generates a wake flow opposite in direction to that of the caudal fin, which creates propulsive jets with time-variant circulations and jet angles. Erectable/foldable fins provide a new design space for bioinspired underwater robots with structures that morph to adapt to different locomotor behaviors. This biorobotic fish model is also a potentially promising system for studying the dynamics of complex multifin fish swimming behaviors, including linear acceleration, steady swimming, and burst and coast, which are difficult to analyze in freely swimming fishes.

  5. Thermal-hydraulic performance of the finned surface of a compact heat exchanger

    International Nuclear Information System (INIS)

    Errasti Cabrera, Michel

    2015-01-01

    In this work the thermal-hydraulic behavior of the finned surface of a compact heat exchanger is obtained in tube-fin configuration corrugated (wavy). Through numerical simulation are determined average values ​​of intensification of heat transfer and pressure loss in the inter-channel finned. The objective is to characterize the surface to use as a reference, to make comparisons with other heat exchange surfaces enhanced using traditional techniques combined with more current, such as vortex generators. The study is conducted in laminar flow, with Reynolds numbers below 1000. In the working model compact exchanger tubes and corrugated fins (wavy) heat is described, and the results of the coefficient of overall heat transfer and the pressure drop are explained from the local characteristics of the velocity field and temperature inside the heat exchanger. (Full text)

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

    Science.gov (United States)

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

    2016-01-01

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

  7. The FinTech phenomenon: antecedents of financial innovation perceived by the popular press

    OpenAIRE

    Zavolokina, Liudmila; Dolata, Mateusz; Schwabe, Gerhard

    2016-01-01

    The financial industry has been strongly influenced by digitalization in the past few years reflected by the emergence of 'FinTech,' which represents the marriage of 'finance' and 'information technology.' FinTech provides opportunities for the creation of new services and business models and poses challenges to traditional financial service providers. Therefore, FinTech has become a subject of debate among practitioners, investors, and researchers and is highly visible in the popular media. ...

  8. Subcooled boiling heat transfer on a finned surface

    International Nuclear Information System (INIS)

    Kowalski, J.E.; Tran, V.T.; Mills, P.J.

    1992-01-01

    Experimental and numerical studies have been performed to determine the heat transfer coefficients from a finned cylindrical surface to subcooled boiling water. The heat transfer rates were measured in an annular test section consisting of an electrically heated fuel element simulator (FES) with eight longitudinal, rectangular fins enclosed in a glass tube. A two-dimensional finite-element heat transfer model using the Galerkin method was employed to determine the heat transfer coefficients along the periphery of the FES surface. An empirical correlation was developed to predict the heat transfer coefficients during subcooled boiling. The correlation agrees well with the measured data. (6 figures) (Author)

  9. Effects of fin pitch and array of the frost layer growth on extended surface of a heat exchanger

    International Nuclear Information System (INIS)

    Yang, Dong Keun; Lee, Kwan Soo

    2003-01-01

    This paper presents the effects of the fin array and pitch on the frost layer growth of a heat exchanger. The numerical results are compared with experimental data of a cold plate to validate the present model, and agree well with experimental data within a maximum error of 8%. The characteristics of the frost formation on staggered fin array are somewhat different from those of in-line array. For fin pitch below 10 mm, the frost layer growth of second fin in the staggered array is affected by that of first fin. The heat transfer of single fin deteriorate with decreasing fin pitch regardless of fin array, however, the thermal performance of a heat exchanger, considering increase of heat surface area, becomes better

  10. Optimization methodology for large scale fin geometry on the steel containment of a Public Acceptable Simple SMR (PASS)

    International Nuclear Information System (INIS)

    Kim, Do Yun; NO, Hee Cheon; Kim, Ho Sik

    2015-01-01

    Highlights: • Optimization methodology for fin geometry on the steel containment is established. • Optimum spacing is 7 cm in PASS containment. • Optimum thickness is 0.9–1.8 cm when a fin height is 10–25 cm. • Optimal fin geometry is determined in given fin height by overall effectiveness correlation. • 13% of material volume and 43% of containment volume are reduced by using fins. - Abstracts: Heat removal capability through a steel containment is important in accident situations to preserve the integrity of a nuclear power plant which adopts a steel containment concept. A heat transfer rate will be enhanced by using fins on the external surface of the steel containment. The fins, however, cause to increase flow resistance and to deteriorate the heat transfer rate at the same time. Therefore, this study investigates an optimization methodology of large scale fin geometry for a vertical base where a natural convection flow regime is turbulent. Rectangular plate fins adopted in the steel containment of a Public Acceptable Simple SMR (PASS) is used as a reference. The heat transfer rate through the fins is obtained from CFD tools. In order to optimize fin geometry, an overall effectiveness concept is introduced as a fin performance parameter. The optimizing procedure is starting from finding optimum spacing. Then, optimum thickness is calculated and finally optimal fin geometry is suggested. Scale analysis is conducted to show the existence of an optimum spacing which turns out to be 7 cm in case of PASS. Optimum thickness is obtained by the overall effectiveness correlation, which is derived from a total heat transfer coefficient correlation. The total heat transfer coefficient correlation of a vertical fin array is suggested considering both of natural convection and radiation. However, the optimum thickness is changed as a fin height varies. Therefore, optimal fin geometry is obtained as a function of a fin height. With the assumption that the heat

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    John Pablo

    2012-02-01

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

  13. Addressing FinFET metrology challenges in 1X node using tilt-beam CD-SEM

    Science.gov (United States)

    Zhang, Xiaoxiao; Zhou, Hua; Ge, Zhenhua; Vaid, Alok; Konduparthi, Deepasree; Osorio, Carmen; Ventola, Stefano; Meir, Roi; Shoval, Ori; Kris, Roman; Adan, Ofer; Bar-Zvi, Maayan

    2014-04-01

    At 1X node, 3D FinFETS raise a number of new metrology challenges. Gate height and fin height are two of the most important parameters for process control. At present there is a metrology gap in inline in-die measurement of these parameters. In order to fill this metrology gap, in-column beam tilt has been developed and implemented on Applied Materials V4i+ top-down CD-SEM for height measurement. A low tilt (5°) beam and a high tilt (14°) beam have been calibrated to obtain two sets of images providing measurement of sidewall edge width to calculate height in the host. Evaluations are done with applications in both gate height and fin height. TEM correlation with R2 being 0.89 and precision of 0.81nm have been achieved on various in-die features in gate height application. Fin height measurement shows less accuracy (R2 being 0.77) and precision (1.49 nm) due to challenges brought by fin geometry, yet still promising as first attempt. Sensitivity to DOE offset, die-to-die and in-die variation is demonstrated in both gate height and fin height. Process defect is successfully captured from inline wafers with gate height measurement implemented in production. This is the first successful demonstration of inline in-die gate height measurement for 14nm FinFET process control.

  14. Ceramic finned-plate recuperator for industrial applications

    Energy Technology Data Exchange (ETDEWEB)

    Coombs, M.; Strumpf, H.; Kotchick, D.

    1985-01-01

    High-level recuperation of high-temperature industrial furnaces offers an economically effective means for improving both process and fuel utilization. A ceramic recuperator capable of operating in fuel gas temperatures of up to 1350/sup 0/C and providing a combustion air preheat temperature of 1100/sup 0/C can provide in excess of 50 percent savings in fuel comsumption over an unrecuperated furnace. This recuperator consists of an array of cast ceramic finned plates. The fin geometries are such that when the plates are stacked together, they form the heat transfer flow passages for both the flue gas and combustion air streams. A reference design for industrial recuperator system was created. The current development efforts conducted on this recuperator concept, as well as plans for future activities, are described.

  15. Dependence and physical exercise: Spanish validation of the Exercise Dependence Scale-Revised (EDS-R).

    Science.gov (United States)

    Sicilia, Alvaro; González-Cutre, David

    2011-05-01

    The purpose of this study was to validate the Spanish version of the Exercise Dependence Scale-Revised (EDS-R). To achieve this goal, a sample of 531 sport center users was used and the psychometric properties of the EDS-R were examined through different analyses. The results supported both the first-order seven-factor model and the higher-order model (seven first-order factors and one second-order factor). The structure of both models was invariant across age. Correlations among the subscales indicated a related factor model, supporting construct validity of the scale. Alpha values over .70 (except for Reduction in Other Activities) and suitable levels of temporal stability were obtained. Users practicing more than three days per week had higher scores in all subscales than the group practicing with a frequency of three days or fewer. The findings of this study provided reliability and validity for the EDS-R in a Spanish context.

  16. The FinTech phenomenon: antecedents of financial innovation perceived by the popular press

    OpenAIRE

    Zavolokina, Liudmila; Dolata, Mateusz; Schwabe, Gerhard

    2016-01-01

    The financial industry has been strongly influenced by digitalization in the past few years reflected by the emergence of “FinTech,” which represents the marriage of “finance” and “information technology.” FinTech provides opportunities for the creation of new services and business models and poses challenges to traditional financial service providers. Therefore, FinTech has become a subject of debate among practitioners, investors, and researchers and is highly visible in the popular media. ...

  17. The use of pelvic fins for benthic locomotion during foraging behavior in Potamotrygon motoro (Chondrichthyes: Potamotrygonidae

    Directory of Open Access Journals (Sweden)

    Akemi Shibuya

    2015-06-01

    Full Text Available Synchronized bipedal movements of the pelvic fins provide propulsion (punting during displacement on the substrate in batoids with benthic locomotion. In skates (Rajidae this mechanism is mainly generated by the crural cartilages. Although lacking these anatomical structures, some stingray species show modifications of their pelvic fins to aid in benthic locomotion. This study describes the use of the pelvic fins for locomotory performance and body re-orientation in the freshwater stingray Potamotrygon motoro (Müller & Henle, 1841 during foraging. Pelvic fin movements of juvenile individuals of P. motoro were recorded in ventral view by a high-speed camera at 250-500 fields/s-1. Potamotrygon motoro presented synchronous, alternating and unilateral movements of the pelvic fins, similar to those reported in skates. Synchronous movements were employed during straightforward motion for pushing the body off the substrate as well as for strike feeding, whereas unilateral movements were used to maneuver the body to the right or left during both locomotion and prey capture. Alternating movements of the pelvic fins are similar to bipedal movements in terrestrial and semi-aquatic tetrapods. The pelvic fins showed coordinated movements during feeding even when stationary, indicating that they have an important function in maintaining body posture (station holding during prey capture and manipulation. The use of pelvic fins during prey stalking may be advantageous because it results in less substrate disturbance when compared to movements generated by pectoral fin undulation. The range of pelvic fin movements indicates more complex control and coordination of the pelvic radial muscles.

  18. Charge based DC compact modeling of bulk FinFET transistor

    Science.gov (United States)

    Cerdeira, A.; Garduño, I.; Tinoco, J.; Ritzenthaler, R.; Franco, J.; Togo, M.; Chiarella, T.; Claeys, C.

    2013-09-01

    Multiple-gate MOSFETs became an industrial reality in the last years. Due to a pragmatic trade-off between CMOS process baselines compatibility, improved performance compared to planar bulk architecture, and cost, bulk FinFETs emerged as the technological solution to provide downscaling for the 14/22 nm technological nodes. In this work, a charge based DC compact model based on the SDDG Model is demonstrated for this new generation of FinFET transistors and describes continuously the transistor characteristics in all operating regions. Validating the model against two bulk FinFET baselines (NMOS, PMOS, various gate lengths and EOT), an excellent agreement is found for transfer and output characteristics (linear and saturation regimes), transconductance/output conductance, and gm/IDS characteristics. Temperature dependence is also taken into account and validated (T range from 25 °C up to 175 °C).

  19. Performance evaluation of a wavy-fin heat sink for power electronics

    International Nuclear Information System (INIS)

    Lorenzini, Marco; Fabbri, Giampietro; Salvigni, Sandro

    2007-01-01

    The almost daily increase in dissipated power per unit area of electronic components sets higher and higher demands on the performance of the heat sinks. These must not only be able to dissipate high heat fluxes, but must also keep costs to a minimum and exhibit a reliable behaviour. In this paper a novel, modular heat sink consisting of elements with wavy fin profile which can be pressed together to construct the component is presented. Its performance under steady-state conditions are assessed for the case of forced convection in terms of velocity distribution in the channels and global thermal resistance. Configurations with uniform and non-uniform heat flux are studied and some considerations are made as to the influence of the spacers between fan and heat sink proper

  20. EDS becoms CERN Openlab contributor

    CERN Multimedia

    2007-01-01

    "EDS announced that it has become an official contributor to CERN openlab. The purpose of the joint project beteween CERN and EDS is to carry out research and development in the field of monitoring, management and operation of grid services." (1 page)

  1. RT-PCR Analysis of ED-A,ED-B, and IIICS Fibronectin Domains: A New Screening Marker For Bladder Cancer

    Directory of Open Access Journals (Sweden)

    M Ahmadi Javid

    2004-12-01

    Full Text Available Background: Fibronectin seems to play a very important role in the progression and invasion of bladder cancer. EDA, EDB, and IIICS domains of fibronectin are not expressed in the adult persons but they’re expressed in different cancers. The aim of this study is to investigate the mRNA of fibronectin in transitional carcinoma cells (TCC of bladder to study these domains. Methods: A total of 20 patients with known bladder cancer were studied. Two of them excluded since their excised tissues were not enough for both the pathological examination and RNA study. Another 20 (control group were normal volunteers who needed bladder operations. The excised tissue was immediately transferred to RNAlater (Ambion,TX. RNA was extracted via RNAWIZ (Ambion, TX. cDNA was made via RevertAid First Strand cDNA Synthesis Kit (Fermentas. PCR of the cDNAs was performed using primers for EDA, EDB, and IIICS (Eurogentec,Belgium. Results: For the first time, we present the expression of the oncofetal fibronectin mRNA in the transitional cell carcinoma of bladder. The high grade muscle invasive (G3T2 tumor, expressed ED-A, ED-B, and IIICS. Expression of ED-A, ED-B, and IIICS was confirmed in the two patients with G3T1 TCC. The four patients with G2Ta and G3Ta expressed both ED-A and ED-B. The four patients with G1T1 tumor expressed ED-A only, similar to the nine patients with G1Ta tumor. None of the normal volunteers expressed the oncofetal extra domains. The sensitivity of ED-A positive fibronectin RNA for detecting TCC of any kind is 100%, and of ED-B was only 35%. The specificity of ED-B positive fibronectin RNA for the high grade TCC is 100%. Conclusion: ED-A, ED-B, and IIICS could be used as useful markers for the diagnosis and following up of bladder carcinoma. Keywords: Transitional Cell Carcinoma, bladder cancer, fibronectin, RT-PCR, oncofetal.

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

    Science.gov (United States)

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

    2002-10-01

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

  3. Aluminum-based one- and two-dimensional micro fin array structures: high-throughput fabrication and heat transfer testing

    International Nuclear Information System (INIS)

    Primeaux, Philip A; Zhang, Bin; Zhang, Xiaoman; Miller, Jacob; Meng, W J; KC, Pratik; Moore, Arden L

    2017-01-01

    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 µ m 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. (paper)

  4. Performance and cost benefits analysis of double-pass solar collector with and without fins

    International Nuclear Information System (INIS)

    Fudholi, Ahmad; Sopian, Kamaruzzaman; Ruslan, Mohd Hafidz; Othman, Mohd Yusof

    2013-01-01

    Highlights: • The thermal performances and cost analysis of the double-pass solar collector with and without fins absorber were discussed. • The theoretical and experimental study on the double-pass solar air collector with and without fins absorber was conducted. • The ratio of AC/AEG or the cost benefit ratio was presented. • The double-pass solar collector with fins absorber is more cost-effective compared to without fins absorber. - Abstract: The performance and cost benefit analysis of double-pass solar collector with and without fins have been conducted. The theoretical model using steady state analysis has been developed and compared with the experimental results. The performance curves of the double-pass solar collector with and without fins, which included the effects of mass flow rate and solar intensity on the thermal efficiency of the solar collector, were obtained. Results indicated that the thermal efficiency is proportional to the solar intensity at a specific mass flow rate. The thermal efficiency increased by 9% at a solar intensity of 425–790 W/m 2 and mass flow rate of 0.09 kg/s. The theoretical and experimental analysis showed a similar trend as well as close agreement. Moreover, a cost-effectiveness model has been developed examine the cost benefit ratio of double-pass solar collector with and without fins. Evaluation of the annual cost (AC) and the annual energy gain (AEG) of the collector were also performed. The results show that the double-pass solar collector with fins is more cost-effective compared to the double-pass solar collector without fins for mass flow rate of 0.01–0.07 kg/s. Also, simulations were obtained for the double-pass solar collector with fins at Nusselt number of 5.42–36.21. The energy efficiency of collector increases with the increase of Nusselt number. The results show that by increasing the Nusselt number simultaneously would drop the outlet temperature at any solar intensity. Increase in Nusselt number

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

    DEFF Research Database (Denmark)

    Subramaniam, Kuttichantran; Toffan, Anna; Cappellozza, Elisabetta

    2016-01-01

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

  6. Ballistic electron transport calculation of strained germanium-tin fin field-effect transistors

    International Nuclear Information System (INIS)

    Lan, H.-S.; Liu, C. W.

    2014-01-01

    The dependence of ballistic electron current on Sn content, sidewall orientations, fin width, and uniaxial stress is theoretically studied for the GeSn fin field-effect transistors. Alloying Sn increases the direct Γ valley occupancy and enhances the injection velocity at virtual source node. (112 ¯ ) sidewall gives the highest current enhancement due to the rapidly increasing Γ valley occupancy. The non-parabolicity of the Γ valley affects the occupancy significantly. However, uniaxial tensile stress and the shrinkage of fin width reduce the Γ valley occupancy, and the currents are enhanced by increasing occupancy of specific indirect L valleys with high injection velocity

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

    International Nuclear Information System (INIS)

    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

    2015-01-01

    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

  8. Experimental studies of Savonius wind turbines with variations sizes and fin numbers towards performance

    Science.gov (United States)

    Utomo, Ilham Satrio; Tjahjana, Dominicus Danardono Dwi Prija; Hadi, Syamsul

    2018-02-01

    The use of renewable energy in Indonesia is still low. Especially the use of wind energy. Wind turbine Savonius is one turbine that can work with low wind speed. However, Savonius wind turbines still have low efficiency. Therefore it is necessary to modify. Modifications by using the fin are expected to increase the positive drag force by creating a flow that can enter the overlap ratio of the gap. This research was conducted using experimental approach scheme. Parameters generated from the experiment include: power generator, power coefficient, torque coefficient. The experimental data will be collected by variation of fin area, horizontal finning, at wind speed 3 m/s - 4,85 m/s. Experimental results show that with the addition of fin can improve the performance of wind turbine Savonius 11%, and by using the diameter of 115 mm fin is able to provide maximum performance in wind turbine Savonius.

  9. DETERMINATION OF TEMPERATURE DISTRIBUTION FOR ANNULAR FINS WITH TEMPERATURE DEPENDENT THERMAL CONDUCTIVITY BY HPM

    Directory of Open Access Journals (Sweden)

    Davood Domairry Ganji

    2011-01-01

    Full Text Available In this paper, homotopy perturbation method has been used to evaluate the temperature distribution of annular fin with temperature-dependent thermal conductivity and to determine the temperature distribution within the fin. This method is useful and practical for solving the nonlinear heat transfer equation, which is associated with variable thermal conductivity condition. The homotopy perturbation method provides an approximate analytical solution in the form of an infinite power series. The annular fin heat transfer rate with temperature-dependent thermal conductivity has been obtained as a function of thermo-geometric fin parameter and the thermal conductivity parameter describing the variation of the thermal conductivity.

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

    International Nuclear Information System (INIS)

    Wang, Y; Zhao, X; Tang, G

    2015-01-01

    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. (paper)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-12-15

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

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

    Science.gov (United States)

    Low, K H; Chong, C W

    2010-12-01

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

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

    International Nuclear Information System (INIS)

    Low, K H; Chong, C W

    2010-01-01

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

  14. Thermal performance of a porus radial fin with natural convection and radiative heat losses

    Directory of Open Access Journals (Sweden)

    Darvishi M.T.

    2015-01-01

    Full Text Available An analytic (series solution is developed to describe the thermal performance of a porous radial fin with natural convection in the fluid saturating the fin and radiation heat loss from the top and bottom surfaces of the fin. The HAM results for the temperature distribution and base heat flux are compared with the direct numerical results and found to be very accurate.

  15. The impact of age and gender on resource utilization and profitability in ED patients seen and released.

    Science.gov (United States)

    Henneman, Philip L; Nathanson, Brian H; Ribeiro, Kara; Balasubramanian, Hari

    2014-10-01

    To determine how age and gender impact resource utilization and profitability in patients seen and released from an Emergency Department (ED). Billing data for patients seen and released from an Emergency Department (ED) with >100,000 annual visits between 2003 and 2009 were collected. Resource utilization was measured by length of stay (placement in ED bed to leaving the bed) and direct clinical costs (e.g., ED nursing salary and benefits, pharmacy and supply costs, etc.) estimated using relative value unit cost accounting. The primary outcome of profitability was defined as contribution margin per hour. A patient's contribution margin by insurance type (excluding self-pay) was determined by subtracting direct clinical costs from facility contractual revenue. Results are expressed as medians and US dollars. In 523 882 outpatient ED encounters, as patients' aged, length of stay and direct clinical cost increased while the contribution margin and contribution margin by hour decreased. Women of childbearing age (15-44) had higher median length of stay (2.1 hours), direct clinical cost ($149), and contribution margin per hour ($103/hour) than men of same age (1.7, $131, $85/hour, respectively). Resource utilization and profitability by gender were similar in children and adults over 45. Resource utilization increased and profitability decreased with increasing age in patients seen and released from an ED. The care of women of childbearing age resulted in higher resource utilization and higher profitability than men of the same age. No differences in resource utilization or profitability by gender were observed in children and adults over 45. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Performance ‘S’ Type Savonius Wind Turbine with Variation of Fin Addition on Blade

    Science.gov (United States)

    Pamungkas, S. F.; Wijayanto, D. S.; Saputro, H.; Widiastuti, I.

    2018-01-01

    Wind power has been receiving attention as the new energy resource in addressing the ecological problems of burning fossil fuels. Savonius wind rotor is a vertical axis wind turbines (VAWT) which has relatively simple structure and low operating speed. These characteristics make it suitable for areas with low average wind speed as in Indonesia. To identify the performance of Savonius rotor in generating electrical energy, this research experimentally studied the effect of fin addition for the ‘S’ shape of Savonius VAWT. The fin is added to fill the space in the blade in directing the wind flow. This rotor has two turbine blades, a rotor diameter of 1.1 m and rotor height of 1.4 m, used pulley transmission system with 1:4.2 multiplication ratio, and used a generator type PMG 200 W. The research was conducted during dry season by measuring the wind speed in the afternoon. The average wind speed in the area is 2.3 m/s with the maximum of 4.5 m/s. It was found that additional fin significantly increase the ability of Savonius rotor VAWT to generate electrical energy shown by increasing of electrical power. The highest power generated is 13.40 Watt at a wind speed of 4.5 m/s by adding 1 (one) fin in the blade. It increased by 22.71% from the rotor blade with no additional fin. However, increasing number of fins in the blade was not linearly increase the electrical power generated. The wind rotor blade with 4 additional fins is indicated has the lowest performance, generating only 10.80 Watt electrical power, accounted lower than the one generated by no fin-rotor blade. By knowing the effect of the rotor shape, the rotor dimension, the addition of fin, transmission, and generator used, it is possible to determine alternative geometry design in increasing the electrical power generated by Savonius wind turbine.

  17. Optimum design of vaporizer fin with liquefied natural gas by numerical analysis

    International Nuclear Information System (INIS)

    Jeong, Hyo Min; Chung, Han Shik; Lee, Sang Chul; Kong, Tae Woo; Yi, Chung Seub

    2006-01-01

    Generally, the temperature drop under 0 .deg. C on vaporizer surface creates frozen dews. This problem seems to increase as the time progress and humidity rises. In addition, the frozen dews create frost deposition. Consequently, heat transfer on vaporizer decreases because frost deposition causes adiabatic condition. Therefore, it is very important to solve this problem. This paper aims to study of the optimum design of used vaporizer at local LNG station. In this paper, experimental results were compared with numerical results. Geometries of numerical and experimental vaporizers were identical. Studied parameters of vaporizer are angle between two fins (Φ) and fin thickness (TH F ). Numerical analysis results were presented through the correlations between the ice layer thickness (TH ICE ) on the vaporizer surface to the temperature distribution of inside vaporizer (T IN ), fin thickness (TH F ), and angle between two fins (Φ). Numerical result shows good agreement with experimental outcome. Finally, the correlations for optimum design of vaporizer are proposed on this paper

  18. Phenotypic variation in dorsal fin morphology of coastal bottlenose dolphins (Tursiops truncatus off Mexico

    Directory of Open Access Journals (Sweden)

    Eduardo Morteo

    2017-06-01

    Full Text Available Geographic variation in external morphology is thought to reflect an interplay between genotype and the environment. Morphological variation has been well-described for a number of cetacean species, including the bottlenose dolphin (Tursiops truncatus. In this study we analyzed dorsal fin morphometric variation in coastal bottlenose dolphins to search for geographic patterns at different spatial scales. A total of 533 dorsal fin images from 19 available photo-identification catalogs across the three Mexican oceanic regions (Pacific Ocean n = 6, Gulf of California n = 6 and, Gulf of Mexico n = 7 were used in the analysis. Eleven fin shape measurements were analyzed to evaluate fin polymorphism through multivariate tests. Principal Component Analysis on log-transformed standardized ratios explained 94% of the variance. Canonical Discriminant Function Analysis on factor scores showed separation among most study areas (p < 0.05 with exception of the Gulf of Mexico where a strong morphometric cline was found. Possible explanations for the observed differences are related to environmental, biological and evolutionary processes. Shape distinction between dorsal fins from the Pacific and those from the Gulf of California were consistent with previously reported differences in skull morphometrics and genetics. Although the functional advantages of dorsal fin shape remains to be assessed, it is not unlikely that over a wide range of environments, fin shape may represent a trade-off among thermoregulatory capacity, hydrodynamic performance and the swimming/hunting behavior of the species.

  19. Differentiation of chondrocytes and scleroblasts during dorsal fin skeletogenesis in flounder larvae.

    Science.gov (United States)

    Suzuki, Tohru; Haga, Yutaka; Takeuchi, Toshio; Uji, Susumu; Hashimoto, Hisashi; Kurokawa, Tadahide

    2003-01-01

    In teleosts, the embryonic fin fold consists of a peridermis, an underlying epidermis and a small number of mesenchymal cells. Beginning from such a simple structure, the fin skeletons, including the proximal and distal radials and lepidotrichia (finrays), develop in the dorsal fin fold at the larval stage. Their process of skeletogenesis and embryonic origin are unclear. Using flounder larvae, we report the differentiation process for chondrocytes and scleroblasts prior to fin skeletogenesis and the effects of retinoic acid (RA) on it. In early larvae, the mesenchymal cells grow between the epidermis and spinal cord to form a line of periodical condensations, which are proximal radial primordia, to produce chondrocytes. The prescleroblasts, which ossify the proximal radial cartilages, differentiate in the mesenchymal cells remaining between the cartilages. Then, mesenchymal condensations occur between the distal ends of the proximal radials, forming distal radial primordia, to produce chondrocytes. Simultaneously, condensations occur between the distal radial primordia and peridermis, which are lepidotrichia primordia, to produce prescleroblasts. Exogenous RA specifically inhibits the mesenchymal condensation prior to the proximal radial formation together with the down-regulation of sonic hedgehog (shh) and patched (pta) expression, resulting in the loss of proximal radials. Thus, it was indicated that differentiation of the precursor cells of radials and lepidotrichia begins in the proximal part of the fin fold and that the initial mesenchymal condensation prior to the proximal radial formation is highly susceptible to the effects of RA. Lepidotrichia formation does not occur where proximal radials are absent, indicating that lepidotrichia differentiation requires interaction with the radial cartilages. To examine the suggestion that neural crest cells contribute to the medial fin skeletons, we localized the HNK-1 positive cells in flounder embryos and slug and

  20. CFD analysis of fin tube heat exchanger with a pair of delta winglet vortex generators

    International Nuclear Information System (INIS)

    Hwang, Seong Won; Kim, Dong Hwan; Min, June Kee; Jeong, Ji Hwan

    2012-01-01

    Among tubular heat exchangers, fin tube types are the most widely used in refrigeration and air-conditioning equipment. Efforts to enhance the performance of these heat exchangers included variations in the fin shape from a plain fin to a slit and louver type. In the context of heat transfer augmentation, the performance of vortex generators has also been investigated. Delta winglet vortex generators have recently attracted research interest, partly due to experimental data showing that their addition to fin-tube heat exchangers considerably reduces pressure loss at heat transfer capacity of nearly the same level. The efficiency of the delta winglet vortex generators widely varies depending on their size and shape, as well as the locations where they are implemented. In this paper, the flow field around delta winglet vortex generators in a common flow up arrangement was analyzed in terms of flow characteristics and heat transfer using computational fluid dynamics methods. Flow mixing due to vortices and delayed separation due to acceleration influence the overall fin performance. The fin with delta winglet vortex generators exhibited a pressure loss lower than that of a plain fin, and the heat transfer performance was enhanced at high air velocity or Reynolds number

  1. CFD analysis of fin tube heat exchanger with a pair of delta winglet vortex generators

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Seong Won; Kim, Dong Hwan; Min, June Kee; Jeong, Ji Hwan [Pusan National Univ., Busan (Korea, Republic of)

    2012-09-15

    Among tubular heat exchangers, fin tube types are the most widely used in refrigeration and air-conditioning equipment. Efforts to enhance the performance of these heat exchangers included variations in the fin shape from a plain fin to a slit and louver type. In the context of heat transfer augmentation, the performance of vortex generators has also been investigated. Delta winglet vortex generators have recently attracted research interest, partly due to experimental data showing that their addition to fin-tube heat exchangers considerably reduces pressure loss at heat transfer capacity of nearly the same level. The efficiency of the delta winglet vortex generators widely varies depending on their size and shape, as well as the locations where they are implemented. In this paper, the flow field around delta winglet vortex generators in a common flow up arrangement was analyzed in terms of flow characteristics and heat transfer using computational fluid dynamics methods. Flow mixing due to vortices and delayed separation due to acceleration influence the overall fin performance. The fin with delta winglet vortex generators exhibited a pressure loss lower than that of a plain fin, and the heat transfer performance was enhanced at high air velocity or Reynolds number.

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

    Science.gov (United States)

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

    2013-03-01

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

  3. State of FinTech in Europe: Mutation perspectives of the banking sector

    OpenAIRE

    Marasco, Marco

    2017-01-01

    This paper studies the relationship between FinTech start-ups and the banking sector. The aim is to assess the impact that the FinTech sector might have on the business model and profitability of banks. Master [120] en sciences de gestion (Mons), Université catholique de Louvain, 2017

  4. Experimental study on the thermal hydraulic performance of plate-fin heat exchangers for cryogenic applications

    Science.gov (United States)

    Jiang, Qingfeng; Zhuang, Ming; Zhang, Qiyong; Zhu, Zhigang; Geng, Maofei; Sheng, Linhai; Zhu, Ping

    2018-04-01

    Efficient and compact plate-fin heat exchangers are critical for large-scale helium liquefaction/refrigeration systems as they constitute major part in the cold box. This study experimentally explores the heat transfer and pressure drop behaviors of helium gas at low temperature in four types of plate-fin channels, namely offset-strip and perforated fins, with different geometrical parameters. A series of cryogenic experiments at approximately liquid nitrogen temperature are carried out to measure the Colburn j factors and Fanning friction f factors with a wide range of Reynolds number. Besides, to reveal the performance variations under different operating temperatures, comparative experiments respectively conducted at room temperature and liquid nitrogen temperature are implemented. The results show that in comparison with the performance data at room temperature, most of j factors are relatively smaller perhaps because the lower aluminum thermal conductivity and higher Prandtl Number at low temperature. Meanwhile, the f factors corresponding to cryogenic conditions exhibit slightly larger even though the core pressure drops show considerable reductions. In contrast to the calculated results from the frequently-used performance curves (Chen and Shen, 1993), the Root Mean Squared Errors of j and f values are correlated within 8.38% and 6.97% for one perforated fin core, 41.29% and 34.97% for three OSF cores, respectively. For OSFs, further comparisons with the previous empirical correlations from literatures are conducted to verify the accuracy of each correlation. Generally, most of the calculated results predict acceptably within the deviations of ±25% for the j factors, while the predicted results express relatively large deviations for the f factors. Therefore, it may be revealed that most of the existing correlations were not able to accurately predict the experimental data in consideration of the performance differences under realistic cryogenic operating

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

    Science.gov (United States)

    Lingham-Soliar, Theagarten

    2005-05-01

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

  6. Del fin de la guerra fria al comienzo de la guerra sin fin

    OpenAIRE

    Ferrier, Jean Pierre

    2006-01-01

    El Profesor Ferrier nos describe los acontecimientos de la sociedad internacional en los ultimos 15 años y señala la profunda diferencia entre "la estabilidad" durante la guerra fría y la "revolucion" que se ha producido en el escenario internacional a partir de la caida del muro de Berlin. Hace especial referencia al comportamiento de la superpotencia (Estados Unidos) y su guerra sin fin contra los "nuevos enemigos" en los diferentes teatros internacionales en su lucha por imponer el "Bien" ...

  7. Numerical analysis on interactions between fluid flow and structure deformation in plate-fin heat exchanger by Galerkin method

    Science.gov (United States)

    Liu, Jing-cheng; Wei, Xiu-ting; Zhou, Zhi-yong; Wei, Zhen-wen

    2018-03-01

    The fluid-structure interaction performance of plate-fin heat exchanger (PFHE) with serrated fins in large scale air-separation equipment was investigated in this paper. The stress and deformation of fins were analyzed, besides, the interaction equations were deduced by Galerkin method. The governing equations of fluid flow and heat transfer in PFHE were deduced by finite volume method (FVM). The distribution of strain and stress were calculated in large scale air separation equipment and the coupling situation of serrated fins under laminar situation was analyzed. The results indicated that the interactions between fins and fluid flow in the exchanger have significant impacts on heat transfer enhancement, meanwhile, the strain and stress of fins includes dynamic pressure of the sealing head and flow impact with the increase of flow velocity. The impacts are especially significant at the conjunction of two fins because of the non-alignment fins. It can be concluded that the soldering process and channel width led to structure deformation of fins in the exchanger, and degraded heat transfer efficiency.

  8. Effect of fin-endwall fillet on thermal hydraulic performance of airfoil printed circuit heat exchanger

    International Nuclear Information System (INIS)

    Ma, Ting; Xin, Fei; Li, Lei; Xu, Xiang-yang; Chen, Yi-tung; Wang, Qiu-wang

    2015-01-01

    Printed circuit heat exchanger (PCHE) is recommended to be used for intermediate heat exchanger in Very High Temperature Reactor (VHTR). One of the key features is that it is manufactured by the photochemical etching in order to maintain the internal structure and metal properties. In this paper, a photochemical etching experiment is conducted to manufacture the airfoil PCHE plate. The result indicates that the airfoil fin is not an ideal airfoil profile, but has a fin-endwall fillet. For the purpose of simplifying the numerical model and saving computational time, a validated model with a single fluid is used to further study the effect of fin-endwall fillet on the thermal hydraulic performance of airfoil PCHE. It is found that the fin-endwall fillet can increase the heat transfer and pressure drop in the cases with the non-dimensional longitudinal pitch being 1.63. The effect of fin-endwall fillet on thermal hydraulic performance decreases with the increase of transverse pitch, but the longitudinal pitch has little effect when the non-dimensional longitudinal pitch is greater than 1.88. In the studied cases, the maximum difference of Nusselt number and friction factor between the two models with and without fin-endwall fillet is up to 6.7% and 6.4%. - Highlights: • Fillets are formed in the endwall of airfoil fins during the photochemical etching. • Two-fluid model can be replaced by single-fluid model to perform simulation. • Fin-endwall fillet can increase heat transfer and pressure drop at ζ_l = 1.63. • Effect of fin-endwall fillet decreases as transverse pitch increases at ζ_l = 1.63. • Longitudinal pitch has little effect at ζ_l ≥ 1.88.

  9. Ballistic electron transport calculation of strained germanium-tin fin field-effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Lan, H.-S. [Graduate Institute of Electronics Engineering and Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan (China); Liu, C. W., E-mail: chee@cc.ee.ntu.edu.tw [Graduate Institute of Electronics Engineering and Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan (China); Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, Taiwan (China)

    2014-05-12

    The dependence of ballistic electron current on Sn content, sidewall orientations, fin width, and uniaxial stress is theoretically studied for the GeSn fin field-effect transistors. Alloying Sn increases the direct Γ valley occupancy and enhances the injection velocity at virtual source node. (112{sup ¯}) sidewall gives the highest current enhancement due to the rapidly increasing Γ valley occupancy. The non-parabolicity of the Γ valley affects the occupancy significantly. However, uniaxial tensile stress and the shrinkage of fin width reduce the Γ valley occupancy, and the currents are enhanced by increasing occupancy of specific indirect L valleys with high injection velocity.

  10. Experimental investigations of heat transfer from an internally finned two phase closed thermosyphon

    International Nuclear Information System (INIS)

    Naresh, Y.; Balaji, C.

    2017-01-01

    Highlights: • Experimental investigations on an internally finned vertical thermosyphon. • Two fluids – water and acetone considered. • Optimum fill ratio determined to be 50%. • Addition of internal fins at the condenser leads to improved thermal performance. - Abstract: This paper reports the results of an experimental investigation of heat transfer from an internally finned thermosyphon charged with either water or acetone. Six constant area fins with a rectangular cross section are placed internally along the length at the condenser section. The ratio of initial liquid pool volume to the evaporator volume, known as the filling ratio in a thermosyphon system, has been varied in this study. Experiments are carried out for filling ratios of 20, 50, and 80% for two working fluids (i) water and (ii) acetone. Results show that a fill ratio of 50% gives better heat transfer performance. Providing internal fins at the condenser produces additional condensation which improves the thermal performance of the thermosyphon by 17% in terms of the temperature reduction at the source and sink and 35.48% in terms of reduction in thermal resistance at lower heat inputs. The thermosyphon is tested between power levels of 50 and 275 W.

  11. Development of structural design procedure of plate-fin heat exchanger for HTGR

    Energy Technology Data Exchange (ETDEWEB)

    Mizokami, Yorikata, E-mail: yorikata_mizokami@mhi.co.jp [Mitsubishi Heavy Industries, Ltd., 1-1, Wadasaki-cho 1-Chome, Hyogo-ku, Kobe 652-8585 (Japan); Igari, Toshihide [Mitsubishi Heavy Industries, Ltd., 5-717-1, Fukahori-machi, Nagasaki 851-0392 (Japan); Kawashima, Fumiko [Kumamoto University, 39-1 Kurokami 2-Chome, Kumamoto 860-8555 (Japan); Sakakibara, Noriyuki [Mitsubishi Heavy Industries, Ltd., 5-717-1, Fukahori-machi, Nagasaki 851-0392 (Japan); Tanihira, Masanori [Mitsubishi Heavy Industries, Ltd., 16-5, Konan 2-Chome, Minato-ku, Tokyo 108-8215 (Japan); Yuhara, Tetsuo [The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Hiroe, Tetsuyuki [Kumamoto University, 39-1 Kurokami 2-Chome, Kumamoto 860-8555 (Japan)

    2013-02-15

    Highlights: ► We propose high temperature structural design procedure for plate-fin heat exchanger ► Allowable stresses for brazed structures will be newly discussed ► Validity of design procedure is confirmed by carrying out partial model tests ► Proposed design procedure is applied to heat exchangers for HTGR. -- Abstract: Highly efficient plate-fin heat exchanger for application to HTGR has been focused on recently. Since this heat exchanger is fabricated by brazing a lot of plates and fins, a new procedure for structural design of brazed structures in the HTGR temperature region up to 950 °C is required. Firstly in this paper influences on material strength due to both thermal aging during brazing process and helium gas environment were experimentally examined, and failure mode and failure limit of brazed side-bar structures were experimentally clarified. Secondly allowable stresses for aging materials and brazed structures were newly determined on the basis of the experimental results. For the purpose of validating the structural design procedure including homogenization FEM modeling, a pressure burst test and a thermal fatigue test of partial model for plate-fin heat exchanger were carried out. Finally, results of reference design of plate-fin heat exchangers of recuperator and intermediate heat exchanger for HTGR plant were evaluated by the proposed design criteria.

  12. La Sociedad del Conocimiento y el Fin de la Escuela

    OpenAIRE

    Rodríguez Rojas, Pedro

    2004-01-01

    Educere:Una Brizna de Aliento en el Tiempo Rivas, Pedro El Paradigma Reinante y su Paideia Alonso, Leonor La Experiencia Contemporánea como Expresión del Fin de una ÉticaAlgunas Ideas desde la Postmodernidad para Releer el Dato Educativo Perdomo, José Camilo La Sociedad del Conocimiento y el Fin de la Escuela Rodríguez Rojas, Pedro Escuela, Alteridad y Experiencia de SíLa Producción Pedagógica del Sujeto Valera Villegas, G...

  13. Classical Lie Point Symmetry Analysis of a Steady Nonlinear One-Dimensional Fin Problem

    Directory of Open Access Journals (Sweden)

    R. J. Moitsheki

    2012-01-01

    Full Text Available We consider the one-dimensional steady fin problem with the Dirichlet boundary condition at one end and the Neumann boundary condition at the other. Both the thermal conductivity and the heat transfer coefficient are given as arbitrary functions of temperature. We perform preliminary group classification to determine forms of the arbitrary functions appearing in the considered equation for which the principal Lie algebra is extended. Some invariant solutions are constructed. The effects of thermogeometric fin parameter and the exponent on temperature are studied. Also, the fin efficiency is analyzed.

  14. Performance analysis of pin fins with temperature dependent thermal parameters using the variation of parameters method

    Directory of Open Access Journals (Sweden)

    Cihat Arslantürk

    2016-08-01

    Full Text Available The performance of pin fins transferring heat by convection and radiation and having variable thermal conductivity, variable emissivity and variable heat transfer coefficient was investigated in the present paper. Nondimensionalizing the fin equation, the problem parameters which affect the fin performance were obtained. Dimensionless nonlinear fin equation was solved with the variation of parameters method, which is quite new in the solution of nonlinear heat transfer problems. The solution of variation of parameters method was compared with known analytical solutions and some numerical solution. The comparisons showed that the solutions are seen to be perfectly compatible. The effects of problem parameters were investigated on the heat transfer rate and fin efficiency and results were presented graphically.

  15. Hearing of Mr. Francois Roussely, President of EdF; Audition de M. Francois Roussely, President d'EdF

    Energy Technology Data Exchange (ETDEWEB)

    Roussely, F. [Electricite de France (EDF), 75 - Paris (France)

    2005-07-01

    This document is the proceedings of the hearing of F. Roussely, President of Electricite de France (EdF), at the commission of economic affairs of the French house of commons, about the advisability of the construction of the EPR (European pressurized reactor) demonstration plant and about its possible financing by EdF. In a first part, F. Roussely recalls the European context of deregulation of energy markets and its impact of the French electric power industry (opening of the French market, industrial and social actions of EdF, need of a new generation of nuclear reactor, preservation of EdF's energy mix, warranty of public utility, un-bundling between energy trade and distribution, EdF's turnover and profitability, EdF's foreign daughter companies). In a second part, F. Roussely answers a series of questions asked by the different members of the commission concerning the different points presented in the first part. (J.S.)

  16. Entropy generation and optimization of laminar convective heat transfer and fluid flow in a microchannel with staggered arrays of pin fin structure with tip clearance

    International Nuclear Information System (INIS)

    Shi, Zhongyuan; Dong, Tao

    2015-01-01

    Highlights: • Entropy generation from heat transfer and flow friction are investigated synthetically. • The impact of correlated variables, dimensionless tip clearance, aspect ratio and Reynolds number, are discussed. • Physical interpretation of the result from multiobjective entropy generation minimization is presented. - Abstract: Entropy generation rate accounting for heat transfer and flow friction is presented for the flow in microchannel with staggered pin fin arrays, clearance existing between the pin fin tip and the shroud plate. Within the scope of the present work, entropy generation rate due to heat transfer is levels of magnitude higher than that from flow friction, which is nonetheless not negligible considering its scaling effect on the pumping power consumption, for all cases under investigation. For the pin fin structure with high aspect ratio (height-to-diameter), the effect of tip clearance was found more pronounced with a conductive nature competing with the convective. When this ratio is low, the convective effect dominates the variation of entropy generation by heat transfer and flow friction, the effect of the clearance gap favored by higher aspect ratio. The entropy minimization method is applied to seek for an optimal combination of all impact factors under investigation. The Pareto frontier along with its corresponding solution sets are obtained by Multiobjective Optimization Genetic Algorithm. The solution sets acquired for the scenario with high-aspect-ratio pin fin fall within the region of lower pin fin density where the trade off between the convective and the conductive effects is identified. On the other hand, dominated by the convective nature, the solution sets for cases with lower aspect ratio are in principle located at the upper bounds

  17. Optimization of fin geometry in heat convection with entransy theory

    International Nuclear Information System (INIS)

    Cheng Xue-Tao; Xu Xiang-Hua; Liang Xin-Gang; Zhang Qin-Zhao

    2013-01-01

    The entransy theory developed in recent years is used to optimize the aspect ratio of a plate fin in heat convection. Based on a two-dimensional model, the theoretical analysis shows that the minimum thermal resistance defined with the concept of entransy dissipation corresponds to the maximum heat transfer rate when the temperature of the heating surface is fixed. On the other hand, when the heat flux of the heating surface is fixed, the minimum thermal resistance corresponds to the minimum average temperature of the heating surface. The entropy optimization is also given for the heat transfer processes. It is observed that the minimum entropy generation, the minimum entropy generation number, and the minimum revised entropy generation number do not always correspond to the best heat transfer performance. In addition, the influence factors on the optimized aspect ratio of the plate fin are also discussed. The optimized ratio decreases with the enhancement of heat convection, while it increases with fin thermal conductivity increasing. (general)

  18. Effect of Collector Aspect Ratio on the Thermal Performance of Wavy Finned Absorber Solar Air Heater

    OpenAIRE

    Abhishek Priyam; Prabha Chand

    2016-01-01

    A theoretical investigation on the effect of collector aspect ratio on the thermal performance of wavy finned absorber solar air heaters has been performed. For the constant collector area, the various performance parameters have been calculated for plane and wavy finned solar air heaters. It has been found that the performance of wavy finned solar air heater improved with the increase in the collector aspect ratio. The performance of wavy finned solar air heater has been found 30 percent hig...

  19. BAT摩拳擦掌布局FinTech

    Institute of Scientific and Technical Information of China (English)

    薛健

    2016-01-01

    数据显示,2015年亚太区FinTech领域投资额的90%集中在中国,而BAT等互联网巨头则参与投资了40%以上的项目。花旗发布的一份研究报告显示,中国FinTech公司的用户数已经等同甚至超越中国最大的银行,并且＂主要归因于阿里、百度、腾讯等互联网巨头在电子商务、第三方支付、网络借贷上的努力＂。

  20. Effects of Tube Diameter and Tubeside Fin Geometry on the Heat Transfer Performance of Air-Cooled Condensers

    Science.gov (United States)

    Wang, H. S.; Honda, Hiroshi

    A theoretical study has been made on the effects of tube diameter and tubeside fin geometry on the heat transfer performance of air-cooled condensers. Extensive numerical calculations of overall heat transfer from refrigerant R410A flowing inside a horizontal microfin tube to ambient air were conducted for a typical operating condition of the air-cooled condenser. The tubeside heat transfer coefficient was calculated by applying a modified stratified flow model developed by Wang et al.8). The numerical results show that the effects of tube diameter, fin height, fin number and helix angle of groove are significant, whereas those of the width of flat portion at the fin tip, the radius of round corner at the fin tip and the fin half tip angle are small.

  1. Hand-held ultrasound serving three EDs.

    Science.gov (United States)

    2007-02-01

    Having a portable ultrasound available to your ED will enable you to perform scans during the nighttime hours, instead of having patients wait for several hours until the radiology department opens. Additional time can be saved by having a technologist read the scans, which frees your ED physicians for other duties. Having ED docs contact the technologist directly, rather than going through a resident, also saves valuable time. Arriving at a diagnosis more quickly provides a boost to patient safety.

  2. Modeling Nanoscale FinFET Performance by a Neural Network Method

    Directory of Open Access Journals (Sweden)

    Jin He

    2017-07-01

    Full Text Available This paper presents a neural network method to model nanometer FinFET performance. The principle of this method is firstly introduced and its application in modeling DC and conductance characteristics of nanoscale FinFET transistor is demonstrated in detail. It is shown that this method does not need parameter extraction routine while its prediction of the transistor performance has a small relative error within 1 % compared with measured data, thus this new method is as accurate as the physics based surface potential model.

  3. FinTech的发展现状与金融创新分析

    Institute of Scientific and Technical Information of China (English)

    韩梅

    2016-01-01

    FinTech借助于大数据和科技创新的双重驱动，使得过去无法实现的金融服务如数据反欺诈、智能投顾、快速交易验证等成为现实。 FinTech同传统金融机构一道在重新定义现代金融、设计新的商业模式，给金融行业带来了众多的变革，从零售、支付和转账、财富管理、交易经纪、保险乃至监管都在被FinTech强力改变。 FinTech将很快取代互联网金融，进入主流市场。

  4. Studi Eksperimental Vertical Axis Wind Turbine Tipe Savonius dengan Variasi Jumlah Fin pada Sudu

    Directory of Open Access Journals (Sweden)

    Ola Dwi Sandra Hasan

    2013-09-01

    Full Text Available Salah satu  teknologi sistem konversi energi angin  yang ada adalah turbin Savonius yang merupakan salah satu jenis Vertical Axis Wind Turbine ( VAWT . Turbin Savonius  memiliki  karakteristik strating torsi yang baik, mudah dalam pembutannya dan dapat menerima angin dari segala arah namun kekurangan yang dimiliki adalah coefficient of power (Cp turbin yang rendah. Untuk itu banyak dilakukan penelitian untuk meningkatkan efisiensi dari turbin Savonius. Salah satunya adalah penambahan end plate yang mampu meningkatkan perbedaan tekanan dari kedua sisi sudu sehingga memperbesar drag positif turbin. Untuk itu pada penelitian ini dilakukan variasi jumlah penambahan fin pada sudu. Variasi jumlah fin yang dilakukan adalah 1,2,4 dan 7 fin serta pengujian dengan menggunakan generator dan tanpa generator. Dari hasil pengujian, variasi fin yang dapat meningkatkan Cp turbin Savonius adalah variasi 1 fin jika dibandingkan  turbin standarnya dengan nilai Cp sebesar 0,11.  SKEA turbin Savonius menggunakan generator 12 V;400W dapat  menghasilkan daya maksimal 5,71 Watt pada putaran 134 rpm

  5. Turbulent Heat Transfer of a Finned Plate in a Duct as Tip Clearance Changes

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hae-Kyun; Chung, Bum-Jin [Kyung Hee University, Yongin (Korea, Republic of)

    2015-05-15

    Fins are employed to enhance the cooling performance of a system. There are a number of studies relevant to geometry of fins. Meanwhile, the studies relevant to tip clearance, have not performed enough, which is the distance between the tips of the fins and the wall. We investigated the optimal tip clearance, which maximizes the heat transfers by experimental and numerical analyses with wider range of Re{sub Dh} than the previous studies. Turbulent heat transfers of a finned plate were measured. For an extended range of tip clearance and Re{sub Dh} than other studies. A joint experimental and numerical analyses was performed to measure heat transfers. Mass transfer experiments using electroplating system was used and FLUENT 6.3.26 was used for the calculation. For the narrow tip clearances below 5 mm, were investigated by numerical method only. The bypass flow to the tip clearance region contributes to heat transfer area at the tip clearance region and does not contributes that of the fin region. Thus, the optimal tip clearance was founded and it exists vicinity of 0.2 mm.

  6. Cabaña ED

    Directory of Open Access Journals (Sweden)

    Lorena Troncoso Valencia

    2018-01-01

    Full Text Available Este proyecto denominado Cabaña Ed, de la arquitecta chilena Lorena Troncoso Valencia, es parte de una serie de obras emplazadas en la comuna de Pinto, Región de Ñuble de Chile. Zona de frondosa vegetación de árboles autóctonos y con fugas visuales hacia la cordillera de los Andes. La Cabaña Ed, donde predomina el uso de la madera, se integra muy sutilmente con ese entorno natural. Cabin ED, by the Chilean architect Lorena Troncoso Valencia, is part of a series of works located in the commune of Pinto, Ñuble Region, Chile. This area is characterized by lush vegetation of native trees and visual towards the Andes leaks. In this project the use of wood predominates, which is subtly integrated with the natural environment. In the edition of REVISTARQUIS 11, another project of the architect, located in that same zone of tourist development was presented.

  7. A Cross-Layer Framework for Designing and Optimizing Deeply-Scaled FinFET-Based Cache Memories

    Directory of Open Access Journals (Sweden)

    Alireza Shafaei

    2015-08-01

    Full Text Available This paper presents a cross-layer framework in order to design and optimize energy-efficient cache memories made of deeply-scaled FinFET devices. The proposed design framework spans device, circuit and architecture levels and considers both super- and near-threshold modes of operation. Initially, at the device-level, seven FinFET devices on a 7-nm process technology are designed in which only one geometry-related parameter (e.g., fin width, gate length, gate underlap is changed per device. Next, at the circuit-level, standard 6T and 8T SRAM cells made of these 7-nm FinFET devices are characterized and compared in terms of static noise margin, access latency, leakage power consumption, etc. Finally, cache memories with all different combinations of devices and SRAM cells are evaluated at the architecture-level using a modified version of the CACTI tool with FinFET support and other considerations for deeply-scaled technologies. Using this design framework, it is observed that L1 cache memory made of longer channel FinFET devices operating at the near-threshold regime achieves the minimum energy operation point.

  8. Poor Dietary Guidelines Compliance among Low-Income Women Eligible for Supplemental Nutrition Assistance Program-Education (SNAP-Ed

    Directory of Open Access Journals (Sweden)

    Shinyoung Jun

    2018-03-01

    Full Text Available The Supplemental Nutrition Assistance Program-Education (SNAP-Ed program aims to improve nutritional intakes of low-income individuals (<185% poverty threshold. The objective of this study was to describe the compliance with Dietary Guidelines for Americans (DGA recommendations for fruits, vegetables, and whole grains among SNAP-Ed eligible (n = 3142 and ineligible (n = 3168 adult women (19–70 years nationwide and SNAP-Ed participating women in Indiana (n = 2623, using the NHANES 2007–2012 and Indiana SNAP-Ed survey data, respectively. Sensitivity analysis further stratified women by race/ethnicity and by current SNAP participation (<130% poverty threshold. Nationally, lower-income women were less likely to meet the fruit (21% vs. 25% and vegetable (11% vs. 19% guidelines than higher-income women, but did not differ on whole grains, which were ~5% regardless of income. The income differences in fruit and vegetable intakes were driven by non-Hispanic whites. Fewer SNAP-Ed-eligible U.S. women met fruit (21% vs. 55% and whole grain (4% vs. 18% but did not differ for vegetable recommendations (11% vs. 9% when compared to Indiana SNAP-Ed women. This same trend was observed among current SNAP participants. Different racial/ethnic group relationships with DGA compliance were found in Indiana compared to the nation. Nevertheless, most low-income women in the U.S. are at risk of not meeting DGA recommendations for fruits (79%, vegetables (89%, and whole grains (96%; SNAP-Ed participants in Indiana had higher compliance with DGA recommendations. Increased consumption of these three critical food groups would improve nutrient density, likely reduce calorie consumption by replacing high calorie choices, and improve fiber intakes.

  9. Design and Analyze a New Measuring Lift Device for Fin Stabilizers Using Stiffness Matrix of Euler-Bernoulli Beam.

    Directory of Open Access Journals (Sweden)

    Lihua Liang

    Full Text Available 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

  10. Biology-Inspired Robust Dive Plane Control of Non-Linear AUV Using Pectoral-Like Fins

    Directory of Open Access Journals (Sweden)

    Subramanian Ramasamy

    2010-01-01

    Full Text Available The development of a control system for the dive plane control of non-linear biorobotic autonomous underwater vehicles, equipped with pectoral-like fins, is the subject of this paper. Marine animals use pectoral fins for swimming smoothly. The fins are assumed to be oscillating with a combined pitch and heave motion and therefore produce unsteady control forces. The objective is to control the depth of the vehicle. The mean angle of pitch motion of the fin is used as a control variable. A computational-fluid-dynamics-based parameterisation of the fin forces is used for control system design. A robust servo regulator for the control of the depth of the vehicle, based on the non-linear internal model principle, is derived. For the control law derivation, an exosystem of third order is introduced, and the non-linear time-varying biorobotic autonomous underwater vehicle model, including the fin forces, is represented as a non-linear autonomous system in an extended state space. The control system includes the internal model of a k-fold exosystem, where k is a positive integer chosen by the designer. It is shown that in the closed-loop system, all the harmonic components of order up to k of the tracking error are suppressed. Simulation results are presented which show that the servo regulator accomplishes accurate depth control despite uncertainties in the model parameters.

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

    Science.gov (United States)

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

    2015-10-28

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

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

    Science.gov (United States)

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

    2013-04-01

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

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

    Science.gov (United States)

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

    2013-02-01

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

  14. Introduction of anti-rolling active vertical fin and its application to maneuverability for displacement-type super high speed ship. 2nd Report.; Haisuiryogata chokosokusen no yokoyure seishiyo active suichoku fin no donyu to sojuseieno oyo

    Energy Technology Data Exchange (ETDEWEB)

    Hirayama, T; Saito, Y [Yokohama National University, Yokohama (Japan). Faculty of Engineering; Niihara, Y [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

    1997-12-31

    Discussed herein are the effects of vertical fin projecting downwards from the bottom of a displacement-type superhigh-speed ship, installed to improve its transverse stability and turning ability. The system for simultaneously controlling rudder and vertical fin by the optimum regulator was studied for maneuverability in directional following waves and smooth water, and maneuverability was simulated numerically. A ship is greatly rolled and sloped when running in waves. It is found that the vertical fin shows a high anti-rolling effect when the ship runs straight. The optimum regulator greatly improves maneuverability in waves, reducing rolling by 92%. Increased rolling with the vertical fin, observed in the previous study in directional following waves, is found to be due to the rudder. The optimum position of the fin is determined to control transverse sloping of a turning ship in a superhigh-speed region. 21 refs., 12 figs., 4 tabs.

  15. Introduction of anti-rolling active vertical fin and its application to maneuverability for displacement-type super high speed ship. 2nd Report.; Haisuiryogata chokosokusen no yokoyure seishiyo active suichoku fin no donyu to sojuseieno oyo

    Energy Technology Data Exchange (ETDEWEB)

    Hirayama, T.; Saito, Y. [Yokohama National University, Yokohama (Japan). Faculty of Engineering; Niihara, Y. [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

    1996-12-31

    Discussed herein are the effects of vertical fin projecting downwards from the bottom of a displacement-type superhigh-speed ship, installed to improve its transverse stability and turning ability. The system for simultaneously controlling rudder and vertical fin by the optimum regulator was studied for maneuverability in directional following waves and smooth water, and maneuverability was simulated numerically. A ship is greatly rolled and sloped when running in waves. It is found that the vertical fin shows a high anti-rolling effect when the ship runs straight. The optimum regulator greatly improves maneuverability in waves, reducing rolling by 92%. Increased rolling with the vertical fin, observed in the previous study in directional following waves, is found to be due to the rudder. The optimum position of the fin is determined to control transverse sloping of a turning ship in a superhigh-speed region. 21 refs., 12 figs., 4 tabs.

  16. PENGUKURAN KUALITAS LAYANAN DENGAN HIGHER EDUCATION PERFORMANCE (HEdPERF DAN HIGHER EDUCATION SERVICE QUALITY (HiEdQUAL

    Directory of Open Access Journals (Sweden)

    Ika Widya Ardhyani

    2017-06-01

    Full Text Available Kualitas layanan merupakan kunci sukses dalam pemasaran dan bisnis strategi. Peningkatan kualitas layanan terhadap perguruan tinggi merupakan hal yang perlu mendapatkan prioritas, karena kualitas layanan berhubungan erat dengan peningkatan keuntungan kompetitif. UMAHA merupakan universitas swasta di Sidoarjo. Sejak didirikan tahun 1998 hingga 2015 animo masyarakat terhadap UMAHA terus mengalami peningkatan hal ini ditunjukkan dengan semakin meningkatnya jumlah mahasiswa yang mendaftar. Namun disisi lain masih terjadi keluhan-keluhan terhadap pelayanan akademik. Berdasarkan hal tersebut, maka pengukuran kualitas layanan pendidikan yang akurat sangat penting dilakukan untuk mendapatkan gambaran yang lebih baik dan menjadi pedoman dalam melakukan suatu perbaikan. Item-item dalam penelitian ini diadaptasi dari instrumen HEdPERF dan HiEdQUAL. Pengukuran kualitas layanan dalam penelitian ini akan dilakukan dengan responden dosen, staf administrasi dan mahasiswa sebagai pelanggan perguruan tinggi. Kuesioner digunakan untuk memperoleh data, berupa harapan dan persepsi. Teknik pengambilan sampel yang digunakan dalam penelitian ini adalah cluster sampling. Data yang diperoleh dianalisis dengan menggunakan uji validitas dan uji reliabilitas. Kualitas layanan akan di ukur dengan menggunakan model diskonfirmasi SERVQUAL, yang mendefinisikan kualitas dalam hal perbedaan yang muncul antara harapan pelanggan dan persepsi layanan yang sebenarnya. Hasil perhitungan skor SERVQUAL untuk ketiga responden, menunjukkan masing-masing item belum dapat memenuhi harapan pelanggan. Hal ini ditunjukkan dengan hasil perhitungan semua item yang bernilai negatif.

  17. On the quantitativeness of EDS STEM

    Energy Technology Data Exchange (ETDEWEB)

    Lugg, N.R. [Institute of Engineering Innovation, The University of Tokyo, 2-11-16, Yayoi, Bunkyo-ku, Tokyo 113-8656 (Japan); Kothleitner, G. [Institute for Electron Microscopy and Nanoanalysis, Graz University of Technology, Steyrergasse 17, 8010 Graz (Austria); Centre for Electron Microscopy, Steyrergasse 17, 8010 Graz (Austria); Shibata, N.; Ikuhara, Y. [Institute of Engineering Innovation, The University of Tokyo, 2-11-16, Yayoi, Bunkyo-ku, Tokyo 113-8656 (Japan)

    2015-04-15

    Chemical mapping using energy dispersive X-ray spectroscopy (EDS) in scanning transmission electron microscopy (STEM) has recently shown to be a powerful technique in analyzing the elemental identity and location of atomic columns in materials at atomic resolution. However, most applications of EDS STEM have been used only to qualitatively map whether elements are present at specific sites. Obtaining calibrated EDS STEM maps so that they are on an absolute scale is a difficult task and even if one achieves this, extracting quantitative information about the specimen – such as the number or density of atoms under the probe – adds yet another layer of complexity to the analysis due to the multiple elastic and inelastic scattering of the electron probe. Quantitative information may be obtained by comparing calibrated EDS STEM with theoretical simulations, but in this case a model of the structure must be assumed a priori. Here we first theoretically explore how exactly elastic and thermal scattering of the probe confounds the quantitative information one is able to extract about the specimen from an EDS STEM map. We then show using simulation how tilting the specimen (or incident probe) can reduce the effects of scattering and how it can provide quantitative information about the specimen. We then discuss drawbacks of this method – such as the loss of atomic resolution along the tilt direction – but follow this with a possible remedy: precession averaged EDS STEM mapping. - Highlights: • Signal obtained in EDS STEM maps (of STO) compared to non-channelling signal. • Deviation from non-channelling signal occurs in on-axis experiments. • Tilting specimen: signal close to non-channelling case but atomic resolution is lost. • Tilt-precession series: non-channelling signal and atomic-resolution features obtained. • Associated issues are discussed.

  18. Out-of-plane strain effect on silicon-based flexible FinFETs

    KAUST Repository

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

    2015-01-01

    Summary form only given. We report out-of-plane strain effect on silicon based flexible FinFET, with sub 20 nm wide fins and hafnium silicate based high-κ gate dielectric. Since ultra-thin inorganic solid state substrates become flexible with reduced thickness, flexing induced strain does not enhance performance. However, detrimental effects arise as the devices are subject to various out-of-plane stresses (compressive and tensile) along the channel length.

  19. Out-of-plane strain effect on silicon-based flexible FinFETs

    KAUST Repository

    Ghoneim, Mohamed T.

    2015-06-21

    Summary form only given. We report out-of-plane strain effect on silicon based flexible FinFET, with sub 20 nm wide fins and hafnium silicate based high-κ gate dielectric. Since ultra-thin inorganic solid state substrates become flexible with reduced thickness, flexing induced strain does not enhance performance. However, detrimental effects arise as the devices are subject to various out-of-plane stresses (compressive and tensile) along the channel length.

  20. Transient data acquisition techniques under EDS

    International Nuclear Information System (INIS)

    Telford, S.

    1985-06-01

    This paper is the first of a series which describes the Enrichment Diagnostic System (EDS) developed for the MARS project at Lawrence Livermore National Laboratory. Although EDS was developed for use on AVLIS, the functional requirements, overall design, and specific techniques are applicable to any experimental data acquisition system involving large quantities of transient data. In particular this paper will discuss the techniques and equipment used to do the data acquisition. Included are what types of hardware are used and how that hardware (CAMAC, digital oscilloscopes) is interfaced to the HP computers. In this discussion the author will address the problems encountered and the solutions used, as well as the performance of the instrument/computer interfaces. The second topic the author will discuss is how the acquired data is associated to graphics and analysis portions of EDS through efficient real time data bases. This discussion will include how the acquired data is folded into the overall structure of EDS providing the user immediate access to raw and analyzed data. By example you will see how easily a new diagnostic can be added to the EDS structure without modifying the other parts of the system. 8 figs

  1. FLOW DISTRIBUTION IN A SOLAR COLLECTOR PANEL WITH HORIZONTAL FINS

    DEFF Research Database (Denmark)

    Fan, Jianhua; Shah, Louise Jivan; Furbo, Simon

    2005-01-01

    The objective of this work is to theoretically and experimentally investigate the flow and temperature distribution in a solar collector panel with an absorber consisting of horizontal fins. Fluid flow and heat transfer in the collector panel are studied by means of computational fluid dynamics...... (CFD) calculations. Further, experimental investigations of a 12.5 m² solar collector panel with 16 parallel connected horizontal fins are carried out. The flow distribution through the absorber is evaluated by means of temperature measurements on the backside of the absorber tubes. The measured...

  2. FinTech来袭：重塑金融格局

    Institute of Scientific and Technical Information of China (English)

    李淼

    2016-01-01

    所谓FinTech,就是一种运用高科技来促使金融服务更加富有效率的商业模式。作为当下欧美金融圈、互联网圈极其风靡的概念,FinTech的核心是技术驱动金融创新,用创新的方法和模式改善用户体验,提高服务效率,重塑金融格局。

  3. EMG changes in thigh and calf muscles in fin swimming exercise.

    Science.gov (United States)

    Jammes, Y; Delliaux, S; Coulange, M; Jammes, C; Kipson, N; Brerro-Saby, C; Bregeon, F

    2010-08-01

    Because previous researchers have reported a reduced lactic acid production that accompanies a delayed or an absent ventilatory threshold (VTh) in water-based exercise, we hypothesized that the metaboreflex, activated by muscle acidosis, might be absent in fin swimming. This motor response, delaying the occurrence of fatigue, is characterized by a decreased median frequency (MF) of electromyographic (EMG) power spectrum. Seven healthy subjects performed a maximal fin swimming exercise protocol with simultaneous recordings of surface EMGs in VASTUS MEDIALIS (VM), TIBIALIS ANTERIOR (TA) and GASTROCNEMIUS MEDIALIS (GM). We computed the root mean square (RMS) and MF and recorded the compound evoked muscle potential (M-wave) in VM. We also measured the propulsive force and oxygen uptake (VO (2)), and determined VTh. VTh was absent in 4/7 subjects and measured at 70-90% of VO (2max) in the other three. In the three studied muscles, the global EMG activity (RMS) increased while the MF decreased in proportion of VO (2), the MF changes being significantly higher in VM (-29%) and GM (-39%) than in TA (-19%). Because no M-wave changes were noted, the MF decline was attributed to the recruitment of low-frequency, fatigue-resistant motor units. Our most important finding is the persistence of the metaboreflex even in a situation of reduced muscle acidosis. (c) Georg Thieme Verlag KG Stuttgart . New York.

  4. An experimental study of three-dimensional shock wave/boundary layer interactions generated by sharp fins

    Science.gov (United States)

    Lu, F. K.; Settles, G. S.; Bogdonoff, S. M.

    1983-01-01

    The interaction between a turbulent boundary layer and a shock wave generated by a sharp fin with leading edge sweepback was investigated. The incoming flow was at Mach 2.96 and at a unit Reynolds number of 63 x 10 to the 6th power 0.1 m. The approximate incoming boundary layer thickness was either 4 mm or 17 mm. The fins used were at 5 deg, 9 deg and 15 deg incidence and had leading edge sweepback from 0 deg to 65 deg. The tests consisted of surface kerosene lampblack streak visualization, surface pressure measurements, shock wave shape determination by shadowgraphs, and localized vapor screen visualization. The upstream influence lengths of the fin interactions were correlated using viscous and inviscid flow parameters. The parameters affecting the surface features close to the fin and way from the fin were also identified. Essentially, the surface features in the farfield were found to be conical.

  5. Laminar fluid flow and heat transfer in a fin-tube heat exchanger with vortex generators

    Energy Technology Data Exchange (ETDEWEB)

    Yanagihara, J.I.; Rodriques, R. Jr. [Polytechnic School of Univ. of Sao Paolo, Sao Paolo (Brazil). Dept. of Mechanical Engineering

    1996-12-31

    Development of heat transfer enhancement techniques for fin-tube heat exchangers has great importance in industry. In recent years, heat transfer augmentation by vortex generators has been considered for use in plate fin-tube heat exchangers. The present work describes a numerical investigation about the influence of delta winglet pairs of vortex generators on the flow structure and heat transfer of a plate fin-tube channel. The Navier-Stokes and Energy equations are solved by the finite volume method using a boundary-fitted coordinate system. The influence of vortex generators parameters such as position, angle of attack and aspect ratio were investigated. Local and global influences of vortex generators in heat transfer and flow losses were analyzed by comparison with a model using smooth fin. The results indicate great advantages of this type of geometry for application in plate fin-tube heat exchangers, in terms of large heat transfer enhancement and small pressure loss penalty. (author)

  6. Laminar fluid flow and heat transfer in a fin-tube heat exchanger with vortex generators

    Energy Technology Data Exchange (ETDEWEB)

    Yanagihara, J I; Rodriques, R Jr [Polytechnic School of Univ. of Sao Paolo, Sao Paolo (Brazil). Dept. of Mechanical Engineering

    1997-12-31

    Development of heat transfer enhancement techniques for fin-tube heat exchangers has great importance in industry. In recent years, heat transfer augmentation by vortex generators has been considered for use in plate fin-tube heat exchangers. The present work describes a numerical investigation about the influence of delta winglet pairs of vortex generators on the flow structure and heat transfer of a plate fin-tube channel. The Navier-Stokes and Energy equations are solved by the finite volume method using a boundary-fitted coordinate system. The influence of vortex generators parameters such as position, angle of attack and aspect ratio were investigated. Local and global influences of vortex generators in heat transfer and flow losses were analyzed by comparison with a model using smooth fin. The results indicate great advantages of this type of geometry for application in plate fin-tube heat exchangers, in terms of large heat transfer enhancement and small pressure loss penalty. (author)

  7. Cumulative effects of using pin fin heat sink and porous metal foam on thermal management of lithium-ion batteries

    International Nuclear Information System (INIS)

    Mohammadian, Shahabeddin K.; Zhang, Yuwen

    2017-01-01

    Highlights: • 3D transient thermal analysis of a pouch Li-ion cell has been carried out. • Using pin fin heat sink improves the temperature reduction at low pumping powers. • Using pin fin heat sink enhances the temperature uniformity at low air flow rates. • Porous aluminum foam insertion with pin fins improves temperature reduction. • Porous aluminum foam insertion with pin fins enhances temperature uniformity. - Abstract: Three-dimensional transient thermal analysis of an air-cooled module was carried out to investigate cumulative effects of using pin fin heat sink and porous metal foam on thermal management of a Li-ion (lithium-ion) battery pack. Five different cases were designed as Case 1: flow channel without any pin fin or porous metal foam insertion, Case 2: flow channel with aluminum pin fins, Case 3: flow channel with porous aluminum foam pin fins, Case 4: fully inserted flow channel with porous aluminum foam, and Case 5: fully inserted flow channel with porous aluminum foam and aluminum pin fins. The effects of porous aluminum insertions, pin fin types, air flow inlet temperature, and air flow inlet velocity on the temperature uniformity and maximum temperature inside the battery pack were systematically investigated. The results showed that using pin fin heat sink (Case 2) is appropriate only for low air flow velocities. In addition, the use of porous aluminum pin fins or embedding porous aluminum foam inside the air flow channel (Cases 3 and 4) are not beneficial for thermal management improvement. The combination of aluminum pin fins and porous aluminum foam insertion inside the air flow channel (Case 5) is a proper option that improves both temperature reduction and temperature uniformity inside the battery cell.

  8. Electrochemical behavior of tube-fin assembly for an aluminum automotive condenser with improved corrosion resistance

    Science.gov (United States)

    Pech-Canul, M. A.; Guía-Tello, J. C.; Pech-Canul, M. I.; Aguilar, J. C.; Gorocica-Díaz, J. A.; Arana-Guillén, R.; Puch-Bleis, J.

    An aluminum automotive condenser was designed to exhibit high corrosion resistance in the seawater acetic acid test (SWAAT) combining zinc coated microchannel tubes and fins made with AA4343/AA3003(Zn)/AA4343 brazing sheet. Electrochemical measurements in SWAAT solution were carried out under laboratory conditions using tube-fin assembly and individual fin and tube samples withdrawn from the condenser core. The aim was to gain information on the protective role of the zinc sacrificial layer and about changes in corrosion behavior as a function of immersion time. External corrosion of the tube-fin system was simulated by immersion of mini-core samples under open circuit conditions. The corrosion rate increased rapidly during the first 6 h and slowly afterwards. The short time behavior was related to the dissolution of the oxide film and fast dissolution of the outermost part of the zinc diffusion layer. With the aid of cross-sectional depth corrosion potential profiles, it was shown that as the sacrificial layer gets dissolved, the surface concentration of zinc decreases and the potential shifts to less negative values. The results of galvanic coupling of tube and fins in a mini-cell showed that the tube became the anode while the fins exhibited cathodic behavior. An evolution in the galvanic interaction was observed, due to the progressive dissolution of the sacrificial zinc layer. The difference of uncoupled potentials between tube and fins decreased from 71 mV to 32 mV after 84 h of galvanic coupling. At the end of such period there was still a part of the zinc sacrificial layer remaining which would serve for protection of the tube material for even longer periods and there were indications of slight corrosion in the fins.

  9. Electrochemical behavior of tube-fin assembly for an aluminum automotive condenser with improved corrosion resistance

    Directory of Open Access Journals (Sweden)

    M.A. Pech-Canul

    Full Text Available An aluminum automotive condenser was designed to exhibit high corrosion resistance in the seawater acetic acid test (SWAAT combining zinc coated microchannel tubes and fins made with AA4343/AA3003(Zn/AA4343 brazing sheet. Electrochemical measurements in SWAAT solution were carried out under laboratory conditions using tube-fin assembly and individual fin and tube samples withdrawn from the condenser core. The aim was to gain information on the protective role of the zinc sacrificial layer and about changes in corrosion behavior as a function of immersion time. External corrosion of the tube-fin system was simulated by immersion of mini-core samples under open circuit conditions. The corrosion rate increased rapidly during the first 6 h and slowly afterwards. The short time behavior was related to the dissolution of the oxide film and fast dissolution of the outermost part of the zinc diffusion layer. With the aid of cross-sectional depth corrosion potential profiles, it was shown that as the sacrificial layer gets dissolved, the surface concentration of zinc decreases and the potential shifts to less negative values. The results of galvanic coupling of tube and fins in a mini-cell showed that the tube became the anode while the fins exhibited cathodic behavior. An evolution in the galvanic interaction was observed, due to the progressive dissolution of the sacrificial zinc layer. The difference of uncoupled potentials between tube and fins decreased from 71 mV to 32 mV after 84 h of galvanic coupling. At the end of such period there was still a part of the zinc sacrificial layer remaining which would serve for protection of the tube material for even longer periods and there were indications of slight corrosion in the fins. Keywords: Aluminum, Automotive, Corrosion, Galvanic, Zn coating

  10. Collector Efficiency in Downward-Type Double-Pass Solar Air Heaters with Attached Fins and Operated by External Recycle

    Directory of Open Access Journals (Sweden)

    Chii-Dong Ho

    2012-07-01

    Full Text Available The collector efficiency in a downward-type double-pass external-recycle solar air heater with fins attached on the absorbing plate has been investigated theoretically. Considerable improvement in collector efficiency is obtainable if the collector is equipped with fins and the operation is carried out with an external recycle. Due to the recycling, the desirable effect of increasing the heat transfer coefficient compensates for the undesirable effect of decreasing the driving force (temperature difference of heat transfer, while the attached fins provide an enlarged heat transfer area. The order of performances in the devices of same size is: double pass with recycle and fins > double pass with recycle but without fins > single pass without recycle and fins.

  11. Effect of Ion Flux (Dose Rate) in Source-Drain Extension Ion Implantation for 10-nm Node FinFET and Beyond on 300/450mm Platforms

    Science.gov (United States)

    Shen, Ming-Yi

    The improvement of wafer equipment productivity has been a continuous effort of the semiconductor industry. Higher productivity implies lower product price, which economically drives more demand from the market. This is desired by the semiconductor manufacturing industry. By raising the ion beam current of the ion implanter for 300/450mm platforms, it is possible to increase the throughput of the ion implanter. The resulting dose rate can be comparable to the performance of conventional ion implanters or higher, depending on beam current and beam size. Thus, effects caused by higher dose rate must be investigated further. One of the major applications of ion implantation (I/I) is source-drain extension (SDE) I/I for the silicon FinFET device. This study investigated the dose rate effects on the material properties and device performance of the 10-nm node silicon FinFET. In order to gain better understanding of the dose rate effects, the dose rate study is based on Synopsys Technology CAD (TCAD) process and device simulations that are calibrated and validated using available structural silicon fin samples. We have successfully shown that the kinetic monte carlo (KMC) I/I simulation can precisely model both the silicon amorphization and the arsenic distribution in the fin by comparing the KMC simulation results with TEM images. The results of the KMC I/I simulation show that at high dose rate more activated arsenic dopants were in the source-drain extension (SDE) region. This finding matches with the increased silicon amorphization caused by the high dose-rate I/I, given that the arsenic atoms could be more easily activated by the solid phase epitaxial regrowth process. This increased silicon amorphization led to not only higher arsenic activation near the spacer edge, but also less arsenic atoms straggling into the channel. Hence, it is possible to improve the throughput of the ion implanter when the dopants are implanted at high dose rate if the same doping level

  12. A least squares method for a longitudinal fin with temperature dependent internal heat generation and thermal conductivity

    International Nuclear Information System (INIS)

    Aziz, A.; Bouaziz, M.N.

    2011-01-01

    Highlights: → Analytical solutions for a rectangular fin with temperature dependent heat generation and thermal conductivity. → Graphs give temperature distributions and fin efficiency. → Comparison of analytical and numerical solutions. → Method of least squares used for the analytical solutions. - Abstract: Approximate but highly accurate solutions for the temperature distribution, fin efficiency, and optimum fin parameter for a constant area longitudinal fin with temperature dependent internal heat generation and thermal conductivity are derived analytically. The method of least squares recently used by the authors is applied to treat the two nonlinearities, one associated with the temperature dependent internal heat generation and the other due to temperature dependent thermal conductivity. The solution is built from the classical solution for a fin with uniform internal heat generation and constant thermal conductivity. The results are presented graphically and compared with the direct numerical solutions. The analytical solutions retain their accuracy (within 1% of the numerical solution) even when there is a 60% increase in thermal conductivity and internal heat generation at the base temperature from their corresponding values at the sink temperature. The present solution is simple (involves hyperbolic functions only) compared with the fairly complex approximate solutions based on the homotopy perturbation method, variational iteration method, and the double series regular perturbation method and offers high accuracy. The simple analytical expressions for the temperature distribution, the fin efficiency and the optimum fin parameter are convenient for use by engineers dealing with the design and analysis of heat generating fins operating with a large temperature difference between the base and the environment.

  13. Experimental Study on the Airside Performance of Aluminum Heat Exchangers Having Slim Louver Fins

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Nae Hyun [Incheon Nat’l Univ., Incheon (Korea, Republic of); Cho, Honggi [Samsung Electronics Daejeon, Suwon (Korea, Republic of)

    2017-09-15

    Recent trends in slim air conditioners require heat exchangers of reduced flow depth. In this study, slim louver fin geometry was obtained using predictive correlations. The deduced geometry yielded 10 mm flow depth, 0.9 mm louver pitch, and 35° louver angle. Samples were made and tests were conducted. The new slim sample yielded 36% higher j factor and 2.3% higher f factor compared with those of the standard sample. This implies that 26% reduction of heat exchanger volume was possible by reducing the flow depth. In addition, the j/f1/3 of the slim sample was 55% larger than that of the standard sample. Furthermore, the results are compared with predictions made using existing correlations.

  14. Experimental Study on the Airside Performance of Aluminum Heat Exchangers Having Slim Louver Fins

    International Nuclear Information System (INIS)

    Kim, Nae Hyun; Cho, Honggi

    2017-01-01

    Recent trends in slim air conditioners require heat exchangers of reduced flow depth. In this study, slim louver fin geometry was obtained using predictive correlations. The deduced geometry yielded 10 mm flow depth, 0.9 mm louver pitch, and 35° louver angle. Samples were made and tests were conducted. The new slim sample yielded 36% higher j factor and 2.3% higher f factor compared with those of the standard sample. This implies that 26% reduction of heat exchanger volume was possible by reducing the flow depth. In addition, the j/f1/3 of the slim sample was 55% larger than that of the standard sample. Furthermore, the results are compared with predictions made using existing correlations.

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

    Science.gov (United States)

    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

  16. Numerical study of finned heat pipe-assisted thermal energy storage system with high temperature phase change material

    International Nuclear Information System (INIS)

    Tiari, Saeed; Qiu, Songgang; Mahdavi, Mahboobe

    2015-01-01

    Highlights: • A finned heat pipe-assisted latent heat thermal energy storage system is studied. • The effects of heat pipes spacing and fins geometrical features are investigated. • Smaller heat pipes spacing and longer fins improve the melting rate. • The optimal heat pipe and fin arrangements are determined. - Abstract: 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 and 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 (decreasing the heat pipe spacing) 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. It was also shown that number of the fins does not have a significant effect on the performance of the system

  17. MicroED data collection and processing

    Energy Technology Data Exchange (ETDEWEB)

    Hattne, Johan; Reyes, Francis E.; Nannenga, Brent L.; Shi, Dan; Cruz, M. Jason de la [Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147 (United States); Leslie, Andrew G. W. [Medical Research Council Laboratory of Molecular Biology, Cambridge (United Kingdom); Gonen, Tamir, E-mail: gonent@janelia.hhmi.org [Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147 (United States)

    2015-07-01

    The collection and processing of MicroED data are presented. MicroED, a method at the intersection of X-ray crystallography and electron cryo-microscopy, has rapidly progressed by exploiting advances in both fields and has already been successfully employed to determine the atomic structures of several proteins from sub-micron-sized, three-dimensional crystals. A major limiting factor in X-ray crystallography is the requirement for large and well ordered crystals. By permitting electron diffraction patterns to be collected from much smaller crystals, or even single well ordered domains of large crystals composed of several small mosaic blocks, MicroED has the potential to overcome the limiting size requirement and enable structural studies on difficult-to-crystallize samples. This communication details the steps for sample preparation, data collection and reduction necessary to obtain refined, high-resolution, three-dimensional models by MicroED, and presents some of its unique challenges.

  18. POPs in free-ranging pilot whales, sperm whales and fin whales from the Mediterranean Sea: Influence of biological and ecological factors

    Energy Technology Data Exchange (ETDEWEB)

    Pinzone, Marianna [Laboratory of Oceanology, MARE Centre, B6c, University of Liege, B6c, Allée du 6 Août, 4000 Liege (Belgium); Budzinski, Hélène [ISM/LPTC, Laboratory of Physical and Chemical Chemistry, University of Bordeaux I, 351 Cours de la Libération, 33405 Bordeaux (France); CNRS, EPOC, UMR 5805, F-33400 Talence (France); Tasciotti, Aurélie; Ody, Denis [WWF-France, 6 Rue des Fabres, 13001 Marseille France (France); Lepoint, Gilles; Schnitzler, Joseph [Laboratory of Oceanology, MARE Centre, B6c, University of Liege, B6c, Allée du 6 Août, 4000 Liege (Belgium); Scholl, George [CART, Laboratory of Mass Spectrometry LSM, University of Liege, B6C, Allée du 6 Août, 4000, Liege (Belgium); Thomé, Jean-Pierre [CART, Laboratory of Animal Ecology and Ecotoxicology LEAE, University of Liege, B6c, Allée du 6 Août 11, 4000 Liege (Belgium); Tapie, Nathalie [ISM/LPTC, Laboratory of Physical and Chemical Chemistry, University of Bordeaux I, 351 Cours de la Libération, 33405 Bordeaux (France); CNRS, EPOC, UMR 5805, F-33400 Talence (France); Eppe, Gauthier [CART, Laboratory of Mass Spectrometry LSM, University of Liege, B6C, Allée du 6 Août, 4000, Liege (Belgium); Das, Krishna, E-mail: krishna.das@ulg.ac.be [Laboratory of Oceanology, MARE Centre, B6c, University of Liege, B6c, Allée du 6 Août, 4000 Liege (Belgium)

    2015-10-15

    The pilot whale Globicephala melas, the sperm whale Physeter macrocephalus, and the fin whale Balaenoptera physalus are large cetaceans permanently inhabiting the Mediterranean Sea. These species are subjected to numerous anthropogenic threats such as exposure to high levels of contaminants. Therefore, selected persistent organic pollutants POPs (29 PCBs, 15 organochlorine compounds, 9 PBDEs and 17 PCDD/Fs) were analysed in blubber biopsies of 49 long-finned pilot whales, 61 sperm whales and 70 fin whales sampled in the North Western Mediterranean Sea (NWMS) from 2006 to 2013. Contamination profile and species feeding ecology were then combined through the use of stable isotopes. δ{sup 13}C, δ{sup 15}N values and POPs levels were assessed through IR-MS and GC–MS respectively. To assess the toxic potency of the dioxin-like compounds, the TEQ approach was applied. δ{sup 15}N values were 12.2±1.3‰ for sperm whales, 10.5±0.7‰ for pilot whales and 7.7±0.8‰ in fin whales, positioning sperm whales at higher trophic levels. δ{sup 13}C of the two odontocetes was similar and amounted to −17.3±0.4‰ for sperm whales and −17.8±0.3‰ for pilot whales; whilst fin whales were more depleted (−18.7±0.4‰). This indicates a partial overlap in toothed-whales feeding habitats, while confirms the differences in feeding behaviour of the mysticete. Pilot whales presented higher concentrations than sperm whales for ΣPCBs (38,666±25,731 ng g{sup −1} lw and 22,849±15,566 ng g{sup −1} lw respectively), ΣPBDEs (712±412 ng g{sup −1} lw and 347±173 ng g{sup −1} lw respectively) and ΣDDTs (46,081±37,506 ng g{sup −1} lw and 37,647±38,518 ng g{sup −1} lw respectively). Fin whales presented the lowest values, in accordance with its trophic position (ΣPCBs: 5721±5180 ng g{sup −1} lw, ΣPBDEs: 177±208 ng g{sup −1} lw and ΣDDTs: 6643±5549 ng g{sup −1} lw). Each species was characterized by large inter-individual variations that are more

  19. POPs in free-ranging pilot whales, sperm whales and fin whales from the Mediterranean Sea: Influence of biological and ecological factors

    International Nuclear Information System (INIS)

    Pinzone, Marianna; Budzinski, Hélène; Tasciotti, Aurélie; Ody, Denis; Lepoint, Gilles; Schnitzler, Joseph; Scholl, George; Thomé, Jean-Pierre; Tapie, Nathalie; Eppe, Gauthier; Das, Krishna

    2015-01-01

    The pilot whale Globicephala melas, the sperm whale Physeter macrocephalus, and the fin whale Balaenoptera physalus are large cetaceans permanently inhabiting the Mediterranean Sea. These species are subjected to numerous anthropogenic threats such as exposure to high levels of contaminants. Therefore, selected persistent organic pollutants POPs (29 PCBs, 15 organochlorine compounds, 9 PBDEs and 17 PCDD/Fs) were analysed in blubber biopsies of 49 long-finned pilot whales, 61 sperm whales and 70 fin whales sampled in the North Western Mediterranean Sea (NWMS) from 2006 to 2013. Contamination profile and species feeding ecology were then combined through the use of stable isotopes. δ 13 C, δ 15 N values and POPs levels were assessed through IR-MS and GC–MS respectively. To assess the toxic potency of the dioxin-like compounds, the TEQ approach was applied. δ 15 N values were 12.2±1.3‰ for sperm whales, 10.5±0.7‰ for pilot whales and 7.7±0.8‰ in fin whales, positioning sperm whales at higher trophic levels. δ 13 C of the two odontocetes was similar and amounted to −17.3±0.4‰ for sperm whales and −17.8±0.3‰ for pilot whales; whilst fin whales were more depleted (−18.7±0.4‰). This indicates a partial overlap in toothed-whales feeding habitats, while confirms the differences in feeding behaviour of the mysticete. Pilot whales presented higher concentrations than sperm whales for ΣPCBs (38,666±25,731 ng g −1 lw and 22,849±15,566 ng g −1 lw respectively), ΣPBDEs (712±412 ng g −1 lw and 347±173 ng g −1 lw respectively) and ΣDDTs (46,081±37,506 ng g −1 lw and 37,647±38,518 ng g −1 lw respectively). Fin whales presented the lowest values, in accordance with its trophic position (ΣPCBs: 5721±5180 ng g −1 lw, ΣPBDEs: 177±208 ng g −1 lw and ΣDDTs: 6643±5549 ng g −1 lw). Each species was characterized by large inter-individual variations that are more related to sex than trophic level, with males presenting higher

  20. Structure and Output Characteristics of a TEM Array Fitted to a Fin Heat Exchanger

    Science.gov (United States)

    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.

  1. Thermal performance analysis of optimized hexagonal finned heat sinks in impinging air jet

    Energy Technology Data Exchange (ETDEWEB)

    Yakut, Kenan, E-mail: kyakut@atauni.edu.tr [Department of Mechanical Engineering, Faculty of Engineering, Atatürk University, 25100, Erzurum (Turkey); Yeşildal, Faruk, E-mail: fayesildal@agri.edu.tr [Department of Mechanical Engineering, Faculty of Patnos Sultan Alparslan Natural Sciences and Engineering, Ağrı İbrahim Çeçen University, 04100, Ağrı (Turkey); Karabey, Altuğ, E-mail: akarabey@yyu.edu.tr [Department of Machinery and Metal Technology, Erciş Vocational High School, Yüzüncü Yıl University, 65400, Van (Turkey); Yakut, Rıdvan, E-mail: ryakut@kafkas.edu.tr [Department of Mechanical Engineering, Faculty of Engineering and Architecture, Kafkas University, 36100, Kars (Turkey)

    2016-04-18

    In this study, thermal performance analysis of hexagonal finned heat sinks which optimized according to the experimental design and optimization method of Taguchi were investigated. Experiments of air jet impingement on heated hexagonal finned heat sinks were carried out adhering to the L{sub 18}(2{sup 1*}3{sup 6}) orthogonal array test plan. Optimum geometries were determined and named OH-1, OH-2. Enhancement efficiency with the first law of thermodynamics was analyzed for optimized heat sinks with 100, 150, 200 mm heights of hexagonal fin. Nusselt correlations were found out and variations of enhancement efficiency with Reynolds number presented in η–Re graphics.

  2. The use of hand paddles and fins in front crawl: biomechanical and physiological responses

    Directory of Open Access Journals (Sweden)

    Cristiano Cardoso de Matos

    2013-04-01

    Full Text Available Paddles and fins are used during swim training and practice as tools for improving performance. The use of these equipment can alter physiological and kinematic parameters of swimming. The purpose of this literature review was to present and discussthe effects of paddles and fins on kinematic and physiological variables in front crawl,and provide update on the topic for teachers, researchers, coaches and swimmers. Thirty articles were reviewed. To crawl, paddles can change the averages of stroke length and stroke rate, the average swimming speed, the absolute duration of the stroke phases and the index of coordination. Fins can modify the average stroke rate, the average swimming speed, the kick frequency and deep, and the energy cost. We found no studies that verified the longitudinal effects of the use of paddles and fins on these parameters.

  3. A three-dimensional numerical study and comparison between the air side model and the air/water side model of a plain fin-and-tube heat exchanger

    International Nuclear Information System (INIS)

    Borrajo-Pelaez, R.; Ortega-Casanova, J.; Cejudo-Lopez, J.M.

    2010-01-01

    CFD is becoming an important heat exchanger research technique. It constitutes an inexpensive prediction method, avoiding the need of testing numerous prototypes. Current work in this field is mostly based on air flow models assuming constant temperature of fin-and-tube surface. The purpose of this paper is to present an enhanced model, whose innovation lies in considering additionally the water flow in the tubes and the conduction heat transfer through the fin and tubes, to demonstrate that the neglect of these two phenomena causes a simulation result accuracy reduction. 3-D Numerical simulations were accomplished to compare both an air side and an air/water side model. The influence of Reynolds number, fin pitch, tube diameter, fin length and fin thickness was studied. The exchanger performance was evaluated through two non-dimensional parameters: the air side Nusselt number and a friction factor. It was found that the influence of the five parameters over the mechanical and thermal efficiencies can be well reported using these non-dimensional coefficients. The results from the improved model showed more real temperature contours, with regard to those of the simplified model. Therefore, a higher accuracy of the heat transfer was achieved, yielding better predictions on the exchanger performance.

  4. Single basin solar still with fin for enhancing productivity

    International Nuclear Information System (INIS)

    Velmurugan, V.; Gopalakrishnan, M.; Raghu, R.; Srithar, K.

    2008-01-01

    Distilled water productivity of the single basin solar still is very low. In this work, to augment evaporation of the still basin water, fins were integrated at the basin of the still. Thus production rate accelerated. Also, for further increase in exposure area sponges were used. Experimental results were compared with ordinary basin type still and still with wicks. The governing energy balance equations were solved analytically and compared with experimental results. It was found that 29.6% productivity increased, when wick type solar still was used, 15.3% productivity increased when sponges were used and 45.5% increased when fins were used. A good agreement had been achieved with theoretical results

  5. Ed Watson 1940-2006

    CERN Multimedia

    2006-01-01

    Ed Watson arrived at CERN in March 1973 to work on digital electronics and CAMAC systems under Bob Dobinson, after many years at Rolls Royce in Scotland. He joined the European Muon Collaboration in 1976, where he played a major role in the design, deployment and running of its data acquisition system (DAQ) with David Botterill, Bob Dobinson, and Vicky White. The CAMAC-ROMULUS system was by far the largest and most advanced of its time, and it became a defining standard for DAQ systems for years to come. Ed was deeply involved in the detailed planning of the control rooms and the experiment cabling, as well as sharing the responsibility for the CAMAC readout system. He had a real talent for trouble shooting and played a vital part in supporting the experiment throughout its lifetime. He offered great moral support to the younger members of the collaboration and helped them a great deal with their work. The EMC had a wonderful social life to which Ed was a major contributor - who can forget its barbecues?  In...

  6. Ed Watson - 1940-2006

    CERN Multimedia

    2006-01-01

    Ed Watson passed away suddenly on 1 August in Geneva, he was 66. He leaves his wife and two children. Ed Watson arrived at CERN in March 1973 to work on digital electronics and CAMAC systems under Bob Dobinson, after many years at Rolls Royce in Scotland. He joined the European Muon Collaboration in 1976, where he played a major role in the design, deployment and running of its data acquisition system (DAQ) with David Botterill, Bob Dobinson, and Vicky White. The CAMAC-ROMULUS system was by far the largest and most advanced of its time, and it became a defining standard for DAQ systems for years to come. Ed was deeply involved in the detailed planning of the control rooms and the experiment cabling, as well as sharing the responsibility for the CAMAC readout system. He had a real talent for trouble shooting and played a vital part in supporting the experiment throughout its lifetime. He offered great moral support to the younger members of the collaboration and helped them a great deal with their work. The...

  7. Synchronous seasonal change in fin whale song in the North Pacific.

    Directory of Open Access Journals (Sweden)

    Erin M Oleson

    Full Text Available 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.

  8. Liquid-metal pin-fin pressure drop by correlation in cross flow

    International Nuclear Information System (INIS)

    Wang, Zhibi; Kuzay, T.M.; Assoufid, L.

    1994-01-01

    The pin-fin configuration is widely used as a heat transfer enhancement method in high-heat-flux applications. Recently, the pin-fin design with liquid-metal coolant was also applied to synchrotron-radiation beamline devices. This paper investigates the pressure drop in a pin-post design beamline mirror with liquid gallium as the coolant. Because the pin-post configuration is a relatively new concept, information in literature about pin-post mirrors or crystals is rare, and information about the pressure drop in pin-post mirrors with liquid metal as the coolant is even more sparse. Due to this the authors considered the cross flow in cylinder-array geometry, which is very similar to that of the pin-post, to examine the pressure drop correlation with liquid metals over pin fins. The cross flow of fluid with various fluid characteristics or properties through a tube bank was studied so that the results can be scaled to the pin-fin geometry with liquid metal as the coolant. Study lead to two major variables to influence the pressure drop: fluid properties, viscosity and density, and the relative length of the posts. Correlation of the pressure drop between long and short posts and the prediction of the pressure drop of liquid metal in the pin-post mirror and comparison with an existing experiment are addressed

  9. Analysis and Evaluation of a Vapor-Chamber Fin-Tube Radiator for High-Power Rankine Cycles

    National Research Council Canada - National Science Library

    Haller, Henry

    1965-01-01

    An analytical investigation of a flat, direct- condensing fin-tube radiator employing segmented vapor-chamber fins as a means of improving heat rejection was performed A for illustrative high-power...

  10. Study on heat and mass transfer characteristics of humid air-flow in a fin bundle

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong-Hwi [Air-Conditioner Research Laboratory, LG Electronics, Seoul 153-082 (Korea); Koyama, Shigeru; Kuwahara, Ken [Department of Energy and Environmental Engineering, Kyushu University, Kasuga, Fukuoka 816-8580 (Japan); Kwon, Jeong-Tae [Department of Mechanical Engineering, Hoseo University, Asan, Chungnam 336-795 (Korea); Park, Byung-Duck [School of Mechanical and Automotive Engineering, Kyungpook National University, Sangju, Gyeongbuk 742-711 (Korea)

    2010-11-15

    This paper deals with the heat and mass transfer characteristics of humid air-flow under frosting conditions. A slit fin bundle was used for the simulation of fins of a heat exchanger. The effects of the cooling block temperature, air humidity and air velocity on the frosting characteristics were experimentally investigated. The frosted mass was affected considerably by the cooling block temperature and air humidity. However, the effect of air velocity on it was not so large. The pressure drop was affected remarkably by all experimental parameters in this study. Local heat flux distribution and frost thickness distribution on each fin were predicted from the measured fin temperatures and the mass and energy conservation equations on the frost surface and inside the frost layer. (author)

  11. Desalination of effluent using fin type solar still

    Energy Technology Data Exchange (ETDEWEB)

    Velmurugan, V. [Department of Mechanical Engineering, Infant Jesus College of Engineering, Thoothukudi, Tamil Nadu 628 851 (India); Deenadayalan, C.K.; Vinod, H.; Srithar, K. [Department of Mechanical Engineering, Thiagarajar College of Engineering, Madurai, Tamil Nadu 625 015 (India)

    2008-11-15

    In this work, an attempt is made to produce potable water from industrial effluents. An ordinary basin type solar still integrated with fins at the basin plate is used for experimentation. Since industrial effluent is used as feed, before this still, an effluent settling tank is provided to get clarified effluent. This effluent settling tank is fabricated with three chambers, consists of pebble, coal and sand for settling the impurities and removing the bacteria in the effluents. Sponges, pebbles, black rubber and sand are used in the fin type single basin solar still for enhancing the yield. Results show that the productivity increases considerably due to this modification. A theoretical analysis is also carried out which, closely converges with experimental results. The economic analysis proved that the approximate payback period of such kinds of still is 1 year. (author)

  12. Experimental Study of Heat Transfer Enhancements from Array of Alternate Rectangular Dwarf Fins at Different Inclinations

    Science.gov (United States)

    Awasarmol, Umesh Vandeorao; Pise, Ashok T.

    2018-02-01

    The main objective of this experimental work is to investigate and compare heat transfer enhancement of alternate dwarf fin array at different angles of inclination. In this study, the steady state heat transfer from the full length fin arrays and alternate dwarf fin arrays are measured in natural convection and radiation environment. Largest increase in the Nusselt number was achieved with alternate dwarf fin at angle of orientation 90°, which shows about 28% enhanced heat transfer coefficient as opposed to the full-length fin array with 25% saving in material. In case of non-black FAB, contribution of radiation heat transfer is found to be very small nearly within 1% of the heater input. After coating lamp black contribution of radiation heat transfer is found to increase to about 3-4% of the heater input in the range of temperatures considered in this study.

  13. Numerical study of the thermo-flow performances of novel finned tubes for air-cooled condensers in power plant

    Science.gov (United States)

    Guo, Yonghong; Du, Xiaoze; Yang, Lijun

    2018-02-01

    Air-cooled condenser is the main equipment of the direct dry cooling system in a power plant, which rejects heat of the exhaust steam with the finned tube bundles. Therefore, the thermo-flow performances of the finned tubes have an important effect on the optimal operation of the direct dry cooling system. In this paper, the flow and heat transfer characteristics of the single row finned tubes with the conventional flat fins and novel jagged fins are investigated by numerical method. The flow and temperature fields of cooling air for the finned tubes are obtained. Moreover, the variations of the flow resistance and average convection heat transfer coefficient under different frontal velocity of air and jag number are presented. Finally, the correlating equations of the friction factor and Nusselt number versus the Reynolds number are fitted. The results show that with increasing the frontal velocity of air, the heat transfer performances of the finned tubes are enhanced but the pressure drop will increase accordingly, resulting in the average convection heat transfer coefficient and friction factor increasing. Meanwhile, with increasing the number of fin jag, the heat transfer performance is intensified. The present studies provide a reference in optimal designing for the air-cooled condenser of direct air cooling system.

  14. ED leadership competency matrix: an administrative management tool.

    Science.gov (United States)

    Propp, Douglas A; Glickman, Seth; Uehara, Dennis T

    2003-10-01

    A successful ED relies on its leaders to master and demonstrate core competencies to be effective in the many arenas in which they interact and are responsible. A unique matrix model for the assessment of an ED leadership's key administrative skill sets is presented. The model incorporates capabilities related to the individual's cognitive aptitude, experience, acquired technical skills, behavioral characteristics, as well as the ability to manage relationships effectively. Based on the personnel inventory using the matrix, focused evaluation, development, and recruitment of ED key leaders occurs. This dynamic tool has provided a unique perspective for the evaluation and enhancement of overall ED leadership performance. It is hoped that incorporation of such a model will similarly improve the accomplishments of EDs at other institutions.

  15. FinTech Market Development Perspectives

    OpenAIRE

    Kalmykova, Ekaterina Yurievna; Ryabova, Anna

    2016-01-01

    Fast development of technologies has led to emergence of the new market – FinTech – which is very attractive for investors today. By now this market has a great number of different concepts: P2P-crediting, E-wallets, Bitcoins, mPOS-acquiring, T-commerce, mobile banks, etc. Many of these tools have already heavily entered our ordinary life. People can obtain any credits through special services on the Internet from other users without participation of banks, pay by credit card using mobile dev...

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

    Science.gov (United States)

    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).

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

    Directory of Open Access Journals (Sweden)

    Andrew T Fields

    Full Text Available 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.

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

    International Nuclear Information System (INIS)

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

    2009-01-01

    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

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

    Directory of Open Access Journals (Sweden)

    Zhang Yong-Hua

    2013-10-01

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

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

    Science.gov (United States)

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

    2017-03-15

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

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

    Directory of Open Access Journals (Sweden)

    Junji Itou

    2012-06-01

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

  2. 香港金融科技的未来%La future de FinTech à Hong Kong

    Institute of Scientific and Technical Information of China (English)

    香港金融发展局; 杨鑫

    2017-01-01

    FinTech - l'innovation financiére grace à la technologie - a le potentiel d'apporter des améliorations substantielles de la productivité et de la qualité des services financiers à Hong Kong. Hong Kong, avec son grand secteur financier, est en mesure de gagner de la tendance FinTech et de perdre à d'autres centres si cela ne fonctionne pas. Ce rapport propose une stratégie FinTech comprenant cinq programmes FinTech - Cyber sécurité, paiement et réglement de titre un identifiant numérique et KYC, WealthTech, InsurTech et RegTech - pris en charge par un bureau FinTech par lequel le territoire peut être avancé de maniére décisive.

  3. Web 2.0 in Dutch Higher Education

    NARCIS (Netherlands)

    Westera, Wim

    2009-01-01

    Westera, W. (2008). Web 2.0 in Dutch Higher Education. In J. Armstrong & T. Franklin (Eds.), A Review of Current and Developing International Practice in the Use of Social Networking (Web 2.0) in Higher Education (pp. 61-71). Bristol: Clex.

  4. DOE Solid-State Lighting in Higher Ed Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Naomi J.; Curry, Ku' Uipo J.

    2010-07-20

    The focus of the workshop was on higher education facilities because college and university campuses are an important market for lighting products and they use almost every kind of luminaire on the market. This workshop was seen as a chance for SSL manufacturers large and small to get the inside scoop from a group of people that specify, pay for, install, use, maintain, and dispose of lighting systems for nearly every type of application. Workshop attendees explored the barriers to SSL adoption, the applications where SSL products could work better than existing technologies, and where SSL luminaires are currently falling short. This report summarizes the Workshop activities and presentation highlights.

  5. TechEdSat

    Data.gov (United States)

    National Aeronautics and Space Administration — TechEdSat is a 1U CubeSat built by San Jose State University in partnership with NASA Ames Research Center and AAC Microtec. Its mission is to evaluate Space...

  6. Survey of Regulations Applicable to the Finned Containment in Korean Nuclear Power Plant for Light Water Reactor

    International Nuclear Information System (INIS)

    Noh, Hyung Gyun; Kang, Hie Chan

    2016-01-01

    In severe accident, the molten corium would discharge into the reactor cavity and interact with water and concrete of cavity. Molten corium includes non-oxidation metals such as Zr, Fe and Cr. These metal species reacted with water emit hydrogen gas. In addition to this, a mount of steam can be emitted to the containment such as steam line break accident. As a result, steam and hydrogen gas can pressurize containment over the design pressure and threaten its integrity. For this reasons, a concept equipped with finned on the containment building was proposed for coping with prolonged accident. Finned containment can enhance heat transfer to the ambient, and the building itself is working as a heat sink. Multiple metal fins and metal rod are penetrated into containment wall, and the rods are working as an additional path of heat removal. To be accepted in the nuclear power plants, this configuration should satisfy the requirement of heat removal and follow all regulations related with containment also. For applying to Korean nuclear power plants, the finned containment should follow all regulations specialized in Korea such as Nuclear regulatory criteria for light water reactor and Guidelines of nuclear safety examination for light water reactor. A concept of containment as a passive cooling system has been proposed. Furthermore, the new containment concept can be applied on the real containment which satisfies the various regulations. Finned containment would be expected positive effects on heat removal from the containment. If the fins are properly welded to the liner, finned containment could satisfy the leak tightness and prevention of external influences. Finned containment could be favorable to protect external impact like aircraft crash because of the additional structural integrity by the fins

  7. Survey of Regulations Applicable to the Finned Containment in Korean Nuclear Power Plant for Light Water Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Hyung Gyun [Pohang University, Pohang (Korea, Republic of); Kang, Hie Chan [Kunsan University, Gunsan (Korea, Republic of)

    2016-05-15

    In severe accident, the molten corium would discharge into the reactor cavity and interact with water and concrete of cavity. Molten corium includes non-oxidation metals such as Zr, Fe and Cr. These metal species reacted with water emit hydrogen gas. In addition to this, a mount of steam can be emitted to the containment such as steam line break accident. As a result, steam and hydrogen gas can pressurize containment over the design pressure and threaten its integrity. For this reasons, a concept equipped with finned on the containment building was proposed for coping with prolonged accident. Finned containment can enhance heat transfer to the ambient, and the building itself is working as a heat sink. Multiple metal fins and metal rod are penetrated into containment wall, and the rods are working as an additional path of heat removal. To be accepted in the nuclear power plants, this configuration should satisfy the requirement of heat removal and follow all regulations related with containment also. For applying to Korean nuclear power plants, the finned containment should follow all regulations specialized in Korea such as Nuclear regulatory criteria for light water reactor and Guidelines of nuclear safety examination for light water reactor. A concept of containment as a passive cooling system has been proposed. Furthermore, the new containment concept can be applied on the real containment which satisfies the various regulations. Finned containment would be expected positive effects on heat removal from the containment. If the fins are properly welded to the liner, finned containment could satisfy the leak tightness and prevention of external influences. Finned containment could be favorable to protect external impact like aircraft crash because of the additional structural integrity by the fins.

  8. Solving the worldwide emergency department crowding problem - what can we learn from an Israeli ED?

    Science.gov (United States)

    Pines, Jesse M; Bernstein, Steven L

    2015-01-01

    ED crowding is a prevalent and important issue facing hospitals in Israel and around the world, including North and South America, Europe, Australia, Asia and Africa. ED crowding is associated with poorer quality of care and poorer health outcomes, along with extended waits for care. Crowding is caused by a periodic mismatch between the supply of ED and hospital resources and the demand for patient care. In a recent article in the Israel Journal of Health Policy Research, Bashkin et al. present an Ishikawa diagram describing several factors related to longer length of stay (LOS), and higher levels of ED crowding, including management, process, environmental, human factors, and resource issues. Several solutions exist to reduce ED crowding, which involve addressing several of the issues identified by Bashkin et al. This includes reducing the demand for and variation in care, and better matching the supply of resources to demands in care in real time. However, what is needed to reduce crowding is an institutional imperative from senior leadership, implemented by engaged ED and hospital leadership with multi-disciplinary cross-unit collaboration, sufficient resources to implement effective interventions, access to data, and a sustained commitment over time. This may move the culture of a hospital to facilitate improved flow within and across units and ultimately improve quality and safety over the long-term.

  9. Multi-boiling Heat Transfer Analysis of a Convective Straight Fin with Temperature-Dependent Thermal Properties and Internal Heat Generation

    Directory of Open Access Journals (Sweden)

    Gbeminiyi Sobamowo

    2017-10-01

    Full Text Available In this study, by using the finite volume method, the heat transfer in a convective straight fin with temperature-dependent thermal properties and an internal heat generation under multi-boiling heat transfer modes are analyzed. In this regard, the local heat transfer coefficient is considered to vary within a power-law function of temperature. In the present study, the coexistence of all the boiling modes is taken into consideration. The developed heat transfer models and the corresponding numerical solutions are used to investigate the effects of various thermo-geometric parameters on the thermal performance of the longitudinal rectangular fin. The results shows that the fin temperature distribution, the total heat transfer, and the fin efficiency are significantly affected by the thermo-geometric parameters of the fin and the internal heat generation within the fin. The obtained results can provide a platform for improvements in the design of the fin in the heat transfer equipment.

  10. Heat transfer and pressure drop amidst frost layer presence for the full geometry of fin-tube heat exchanger

    International Nuclear Information System (INIS)

    Kim, Sung Jool; Choi, Ho Jin; Ha, Man Yeong; Kim, Seok Ro; Bang, Seon Wook

    2010-01-01

    The present study numerically solves the flow and thermal fields in the full geometry of heat exchanger modeling with frost layer presence on the heat exchanger surface. The effects of air inlet velocity, air inlet temperature, frost layer thickness, fin pitch, fin thickness, and heat exchanger shape on the thermo-hydraulic performance of a fin-tube heat exchanger are investigated. Heat transfer rate rises with increasing air inlet velocity and temperature, and decreasing frost layer thickness and fin pitch. Pressure drop rises with increasing air inlet velocity and frost layer thickness, and decreasing fin pitch. The effect of fin thickness on heat transfer and pressure drop is negligible. Based on the present results, we derived the correlations, which express pressure drop and temperature difference between air inlet and outlet as a function of air inlet velocity and temperature, as well as frost layer thickness

  11. Strain characterization of fin-shaped field effect transistors with SiGe stressors using nanobeam electron diffraction

    International Nuclear Information System (INIS)

    Kim, Sun-Wook; Byeon, Dae-Seop; Jang, Hyunchul; Koo, Sang-Mo; Ko, Dae-Hong; Lee, Hoo-Jeong

    2014-01-01

    This study undertook strain analysis on fin-shaped field effect transistor structures with epitaxial Si 1−x Ge x stressors, using nano-beam electron diffraction and finite elements method. Combining the two methods disclosed dynamic strain distribution in the source/drain and channel region of the fin structure, and the effects of dimensional factors such as the stressor thickness and fin width, offering valuable information for device design.

  12. Strain characterization of fin-shaped field effect transistors with SiGe stressors using nanobeam electron diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sun-Wook; Byeon, Dae-Seop; Jang, Hyunchul; Koo, Sang-Mo; Ko, Dae-Hong, E-mail: dhko@yonsei.ac.kr [Department of Materials Science and Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Lee, Hoo-Jeong, E-mail: hlee@skku.edu [Department of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2014-08-25

    This study undertook strain analysis on fin-shaped field effect transistor structures with epitaxial Si{sub 1−x}Ge{sub x} stressors, using nano-beam electron diffraction and finite elements method. Combining the two methods disclosed dynamic strain distribution in the source/drain and channel region of the fin structure, and the effects of dimensional factors such as the stressor thickness and fin width, offering valuable information for device design.

  13. TechEdSat Nano-Satellite Series Fact Sheet

    Science.gov (United States)

    Murbach, Marcus; Martinez, Andres; Guarneros Luna, Ali

    2014-01-01

    TechEdSat-3p is the second generation in the TechEdSat-X series. The TechEdSat Series uses the CubeSat standards established by the California Polytechnic State University Cal Poly), San Luis Obispo. With typical blocks being constructed from 1-unit (1U 10x10x10 cm) increments, the TechEdSat-3p has a 3U volume with a 30 cm length. The project uniquely pairs advanced university students with NASA researchers in a rapid design-to-flight experience lasting 1-2 semesters.The TechEdSat Nano-Satellite Series provides a rapid platform for testing technologies for future NASA Earth and planetary missions, as well as providing students with an early exposure to flight hardware development and management.

  14. QR Codes in Higher Ed: Fad or Functional Tool?

    Science.gov (United States)

    Gradel, Kathleen; Edson, Alden J.

    2013-01-01

    As higher education grapples with addressing the 21st century needs of learners, technology is a pervasive concern. Waters (2012) painted a picture of three historical "screens," namely the television screen, the computer monitor, and today's mobile device screen. As mobile devices become increasingly commonplace in the workplace and on the…

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

    KAUST Repository

    O'Bryhim, Jason R.

    2017-01-31

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

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

    Science.gov (United States)

    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.

  17. ED breast cases and other breast emergencies.

    Science.gov (United States)

    Khadem, Nasim; Reddy, Sravanthi; Lee, Sandy; Larsen, Linda; Walker, Daphne

    2016-02-01

    Patients with pathologic processes of the breast commonly present in the Emergency Department (ED). Familiarity with the imaging and management of the most common entities is essential for the radiologist. Additionally, it is important to understand the limitations of ED imaging and management in the acute setting and to recognize when referrals to a specialty breast center are necessary. The goal of this article is to review the clinical presentations, pathophysiology, imaging, and management of emergency breast cases and common breast pathology seen in the ED.

  18. Numerical Study of Thermal and Flow Characteristics of Plate-Fin Heat Sink with Longitudinal Vortex Generator Installed on the Ground

    Directory of Open Access Journals (Sweden)

    Yen-Tso Chang

    2014-01-01

    Full Text Available This study applied the commercial software ANSYS CFD (FLUENT, for simulating the transient flow field and investigating the influence of each parameter of longitudinal vortex generators (LVGs on the thermal flux of a plate-fin heat sink. Vortex generator was set in front of plate-fin heat sink and under the channel, which was in common-flow-down (CFD and common-flow-up (CFU conditions, which have the result of vortex generator of delta winglet pair (DWP. In this study the parameters were varied, such as the minimum transverse distance between winglet pair, the attack angle of the vortex generator, fins number, the fin height, and the distance between the vortex generator and plate-fin. The coolant fluid flew into the fin-to-fin channel and pushed the vortex from different geometry toward the bottom. This phenomenon took off the heat from the plate to enhance the heat transfer. The numerical results indicated that the LVGs located close to the plate-fin heat sink are zero with the attack angle being 30°, presenting optimal overall conditions.

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

    KAUST Repository

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

    2017-01-01

    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

  20. Performance enhancement in uniaxially tensile stressed GeSn n-channel fin tunneling field-effect transistor: Impact of stress direction

    Science.gov (United States)

    Wang, Hongjuan; Han, Genquan; Jiang, Xiangwei; Liu, Yan; Zhang, Chunfu; Zhang, Jincheng; Hao, Yue

    2017-04-01

    In this work, the boosting effect on the performance of GeSn n-channel fin tunneling FET (nFinTFET) enabled by uniaxial tensile stress is investigated theoretically. As the fin rotates within the (001) plane, the uniaxial tensile stress is always along its direction. The electrical characteristics of tensile-stressed GeSn nFinTFETs with point and line tunneling modes are computed utilizing the technology computer aided design (TCAD) simulator in which the dynamic nonlocal band-to-band tunneling (BTBT) algorithm is employed. In comparison with the relaxed devices, tensile-stressed GeSn nFinTFETs achieve a substantial enhancement in band-to-band tunneling generation rate (G BTBT) and on-state current I ON owing to the reduced bandgap E G induced by the tensile stress. Performance improvement of GeSn nFinTFETs induced by tensile stress demonstrates a strong dependence on channel direction and tunneling modes. Under the same magnitude of stress, line-nFinTFETs obtain a more pronounced I ON enhancement over the transistors with point tunneling mode.

  1. Fluid-cooled heat sink with improved fin areas and efficiencies for use in cooling various devices

    Science.gov (United States)

    Bharathan, Desikan; Bennion, Kevin; Kelly, Kenneth; Narumanchi, Sreekant

    2015-04-21

    The disclosure provides a fluid-cooled heat sink having a heat transfer base and a plurality of heat transfer fins in thermal communication with the heat transfer base, where the heat transfer base and the heat transfer fins form a central fluid channel through which a forced or free cooling fluid may flow. The heat transfer pins are arranged around the central fluid channel with a flow space provided between adjacent pins, allowing for some portion of the central fluid channel flow to divert through the flow space. The arrangement reduces the pressure drop of the flow through the fins, optimizes average heat transfer coefficients, reduces contact and fin-pin resistances, and reduces the physical footprint of the heat sink in an operating environment.

  2. A Study on Aspect Ratio of Heat Dissipation Fin for the Heat Dissipation Performance of Ultra Constant Discharge Lamp

    Science.gov (United States)

    Ko, Dong Guk; Cong Ge, Jun; Im, Ik Tae; Choi, Nag Jung; Kim, Min Soo

    2018-01-01

    In this study, we analyzed the heat dissipation performance of UCD lamp ballast fin with various aspect ratios. The minimum grid size was 0.02 mm and the number of grid was approximately 11,000. In order to determine the influence of the aspect ratio on the heat dissipation performance of UCD lamp ballast fin, the heat transfer area of the fin was kept constant at 4 mm2. The aspect ratios of the fin were 2 mm: 2 mm (basic model), 1.5 mm: 2.7 mm and 2.7 mm: 1.5 mm, respectively. The heat flux and heat flux time at fin were kept constant at 1×105 W/m2 and 10 seconds, respectively. The heat dissipation performance by the fin was the best at an aspect ratio of 1.5 mm: 2.7 mm.

  3. Higher Dietary Energy Density is Associated with Stunting but not Overweight and Obesity in a Sample of Urban Malaysian Children.

    Science.gov (United States)

    Shariff, Zalilah Mohd; Lin, Khor Geok; Sariman, Sarina; Siew, Chin Yit; Yusof, Barakatun Nisak Mohd; Mun, Chan Yoke; Lee, Huang Soo; Mohamad, Maznorila

    2016-01-01

    Although diets with high energy density are associated with increased risk of overweight and obesity, it is not known whether such diets are associated with undernutrition. This study assessed the relationship between dietary energy density (ED) and nutritional status of 745 urban 1- to 10-year-old children. Dietary intakes were obtained using food recall and record for two days. Dietary energy density was based on food and caloric beverages. Higher dietary ED was associated with lower intakes of carbohydrate, sugar, vitamins C and D, and calcium but higher fat, fiber, iron, and folate intakes. While intakes of fruits and milk/dairy products decreased, meat, fish, and legume intakes increased with higher dietary ED. Stunting, but not other growth problems, was associated with higher dietary ED. Future studies should confirm the cause-and-effect relationship between higher dietary ED and stunting.

  4. Macrofauna edáfica asociada con sistemas agroforestales en la Amazonía Colombiana

    Directory of Open Access Journals (Sweden)

    Juan Carlos Suárez Salazar

    2015-07-01

    Full Text Available La densidad, riqueza y diversidad de la macrofauna edáfica son afectadas, entre otros factores, por la configuración de los agroecosistemas y la estacionalidad de la precipitación. Con el fin de evaluar estos efectos en mayo y noviembre de 2011, correspondientes a épocas de máxima y mínima precipitación, respectivamente, se realizaron estudios sobre la composición de la macrofauna edáfica asociada con los arreglos agroforestales ubicados en el Centro de Investigaciones Macagual Cesar Augusto Estrada González, Amazonia, Caquetá, Colombia. El experimento se dispuso en un diseño completo al azar bifactorial con cuatro tratamientos (arreglos agroforestales: AB = abarco - Cariniana pyriformis Miers; CH = caucho Hevea brasiliensis (Willd. ex A. Juss. Müll. Arg. ; CP = caucho-parica Schizolobium amazonicum Huber; UV = uvito Genipa Americana L. y dos épocas (máxima y mínima precipitación, y cuatro repeticiones en parcelas divididas. Para explorar las relaciones entre los órdenes de macrofauna, se realizó un análisis de componentes principales y se evalúo el efecto de los arreglos agroforestales con una prueba de Monte Carlo. Los resultados mostraron que la densidad de la macrofauna fue mayor en el periodo de máxima precipitación (1129 individuos en comparación con el de mínima (598 individuos. Los arreglos agroforestales influyen sobre la presencia o ausencia de algunos grupos taxonómicos (P < 0.05 como Homoptera (Insecta y Raphidioptera (Insecta; además los UV y AB pueden favorecer a la macrofauna del estrés por sequía

  5. Mixed convection heat transfer between a steam / non-condensable gas mixture and an inclined finned tube bundle

    Energy Technology Data Exchange (ETDEWEB)

    Cachard, F. de; Lomperski, S.; Monauni, G.R. [Paul Scherrer Inst. (PSI), Villigen (Switzerland). Lab. for Thermal-Hydraulics

    1999-07-01

    An experimental and analytical program was performed at PSI to study the performance of a finned-tube condenser in the presence of non-condensable gases at low gas mass fluxes. The model developed for this application includes mixed convection heat transfer between the vapour/non-condensable mixture and the finned-tubes, heat conduction through the fins and tubes, and evaporative heat transfer inside the tubes. The finned-tubes condenser model has been assessed against data obtained at the PSI LINX facility with two test condensers. For the 62 LINX experiments performed, the model predictions are very good, i.e., less than 10 % standard deviation between experimental and predicted results. (authors)

  6. Discipline-Specific Compared to Generic Training of Teachers in Higher Education.

    Science.gov (United States)

    Silva-Fletcher, Ayona; May, Stephen A

    A recurrent theme arising in the higher education sector is the suitability and effectiveness of generic versus discipline-specific training of university teachers, who are often recruited based on their disciplinary specialties to become teachers in higher education. We compared two groups of participants who had undergone training using a generic post-graduate certificate in higher education (PGCertGeneric) versus a discipline-specific course in veterinary education (PGCertVetEd). The study was conducted using a survey that allowed comparison of participants who completed PGCertGeneric (n=21) with PGCertVetEd (n=22). Results indicated that participants from both PGCertGeneric and PGCertVetEd considered teaching to be satisfying and important to their careers, valued the teaching observation component of the course, and identified similar training needs. However, the participants of the PGCertVetEd felt that the course made them better teachers, valued the relevance of the components taught, understood course design better, were encouraged to do further courses/reading in teaching and learning, changed their teaching as a result of the course, and were less stressed about teaching as compared to the PGCertGeneric participants (p<.05). It is likely that the PGCertVetEd, which was designed and developed by veterinarians with a wider understanding of the veterinary sector, helped the participants perceive the training course as suited to their needs.

  7. Improvement in Student Science Proficiency Through InSciEd Out

    Science.gov (United States)

    Sonju, James D.; Leicester, Jean E.; Hoody, Maggie; LaBounty, Thomas J.; Frimannsdottir, Katrin R.; Ekker, Stephen C.

    2012-01-01

    Abstract Integrated Science Education Outreach (InSciEd Out) is a collaboration formed between Mayo Clinic, Winona State University, and Rochester Public Schools (MN) with the shared vision of achieving excellence in science education. InSciEd Out employs an equitable partnership model between scientists, teachers, education researchers, and the community. Teams of teachers from all disciplines within a single school experience cutting-edge science using the zebrafish model system, as well as current pedagogical methods, during a summer internship at the Mayo Clinic. Within the internship, the teachers produce new curriculum that directly addresses opportunities for science education improvement at their own school. Zebrafish are introduced within the new curriculum to support a living model of the practice of science. Following partnership with the InSciEd Out program and 2 years of implementation in the classroom, teacher-interns from a K–8 public school reported access to local scientific technology and expertise they had not previously recognized. Teachers also reported improved integration of other disciplines into the scientific curriculum and a flow of concepts vertically from K through 8. Students more than doubled selection of an Honors science track in high school to nearly 90%. 98% of students who took the Minnesota Comprehensive Assessments in their 5th and 8th grade year (a span that includes 2 years of InSciEd Out) showed medium or high growth in science proficiency. These metrics indicate that cooperation between educators and scientists can result in positive change in student science proficiency and demonstrate that a higher expectation in science education can be achieved in US public schools. PMID:23244687

  8. Impact of residual defects caused by extension ion implantation in FinFETs on parasitic resistance and its fluctuation

    Science.gov (United States)

    Matsukawa, Takashi; Liu, Yongxun; Mori, Takahiro; Morita, Yukinori; Otsuka, Shintaro; O'uchi, Shin-ichi; Fuketa, Hiroshi; Migita, Shinji; Masahara, Meishoku

    2017-06-01

    The influence of extension doping on parasitic resistance and its variability has been investigated for FinFETs. Electrical characterization of FinFETs and crystallinity evaluation of the doped fin structure are carried out for different fin thicknesses and different donor species for ion implantation, i.e., As and P. Reducing the fin thickness and the use of donor species with a larger mass cause serious degradation in the variability and median value of the parasitic resistance. Crystallinity evaluation by transmission electron microscope reveals that significant crystal defects remain after dopant activation annealing for the cases of smaller fin thickness and the implanted dopant with a larger mass. The unrecovered defects cause serious degradation in the parasitic resistance and its variability. In 1998, he joined the Electrotechnical Laboratory, which is former organization of National Institute of Advanced Industrial Science and Technology (AIST). He has been working on development of front-end process technology, variability issues of the FinFETs and technologies for suppressing the variability. He is now a group leader of the AIST and leads the research on the silicon-based CMOS devices. He is a member of the IEEE Electron Devices Society, and the Japan Society of Applied Physics.

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

    Directory of Open Access Journals (Sweden)

    Foued Chabane

    2014-03-01

    Full Text Available 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.

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

    Science.gov (United States)

    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.

  11. Design of spiral fin type condenser for hydrogen cryogenic distillation column

    International Nuclear Information System (INIS)

    Iwai, Yasunori; Nishi, Masataka; Yamanishi, Toshihiko

    2005-08-01

    The purpose of this paper is the proposal of new concept condenser for hydrogen cryogenic distillation column of Hydrogen Isotope Separation System (ISS) in a fusion reactor, and the establishment of numerical evaluation method of the hydrogen isotope inventory in the condenser. A large amount of hydrogen isotopes including high concentration of tritium, radioactive hydrogen isotope, has been handled in the cryogenic distillation column. Therefore, from the safety point of view, cryogenic coolant tube was commonly arranged to surround the condensed area to prevent the mixing of tritium into the coolant. This inevitable arrangement leads the difficulty in the minimization of the condenser. The scale of condenser has influence on the scale of the ISS and its earthquake-resistance. The spiral fin type condenser, which introduces fins inside it and in coolant tube to enhance heat exchange, is proposed as a new concept condenser for hydrogen cryogenic distillation column to miniaturize the condenser. The volume of spiral fin type condenser is estimated to become less than half of that of coil tube type condenser currently in use. Accordingly, it is found that the adoption of spiral fin type condenser realizes the significant miniaturization of the ISS. Moreover, the numerical evaluation method of the hydrogen isotope inventory in the condenser is proposed. The validity of this method was confirmed by the experimental data. The synthetic design of the condenser for the hydrogen cryogenic distillation column is achieved by the combination of the proposed new concept condenser with the numerical evaluation method of the hydrogen isotope inventory. (author)

  12. Erectile Dysfunction (ED)

    Science.gov (United States)

    ... Talking to Your Kids About VirginityTalking to Your Kids About Sex Home Diseases and Conditions Erectile Dysfunction (ED) Condition ... Well-Being Mental Health Sex and Birth Control Sex and Sexuality Birth Control ... and Toddlers Kids and Teens Pregnancy and Childbirth Women Men Seniors ...

  13. Trends in Hospital Admission and Surgical Procedures Following ED visits for Diverticulitis

    Directory of Open Access Journals (Sweden)

    Margaret B. Greenwood-Ericksen

    2016-06-01

    Full Text Available Introduction: Diverticulitis is a common diagnosis in the emergency department (ED. Outpatient management of diverticulitis is safe in selected patients, yet the rates of admission and surgical procedures following ED visits for diverticulitis are unknown, as are the predictive patient characteristics. Our goal is to describe trends in admission and surgical procedures following ED visits for diverticulitis, and to determine which patient characteristics predict admission. Methods: We performed a cross-sectional descriptive analysis using data on ED visits from 2006-2011 to determine change in admission and surgical patterns over time. The Nationwide Emergency Department Sample database, a nationally representative administrative claims dataset, was used to analyze ED visits for diverticulitis. We included patients with a principal diagnosis of diverticulitis (ICD-9 codes 562.11, 562.13. We analyzed the rate of admission and surgery in all admitted patients and in low-risk patients, defined as age <50 with no comorbidities (Elixhauser. We used hierarchical multivariate logistic regression to identify patient characteristics associated with admission for diverticulitis. Results: From 2006 to 2011 ED visits for diverticulitis increased by 21.3% from 238,248 to 302,612, while the admission rate decreased from 55.7% to 48.5% (-7.2%, 95% CI [–7.78 to -6.62]; p<0.001 for trend. The admission rate among low-risk patients decreased from 35.2% in 2006 to 26.8% in 2011 (-8.4%, 95% CI [–9.6 to –7.2]; p<0.001 for trend. Admission for diverticulitis was independently associated with male gender, comorbid illnesses, higher income and commercial health insurance. The surgical rate decreased from 6.5% in 2006 to 4.7% in 2011 (-1.8%, 95% CI [–2.1 to –1.5]; p<0.001 for trend, and among low-risk patients decreased from 4.0% to 2.2% (- 1.8%, 95% CI [–4.5 to –1.7]; p<0.001 for trend. Conclusion: From 2006 to 2011 ED visits for diverticulitis increased

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

    Science.gov (United States)

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

    2017-04-01

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

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

    Science.gov (United States)

    Bazaz Behbahani, Sanaz; Tan, Xiaobo

    2017-08-01

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

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

    Directory of Open Access Journals (Sweden)

    Mugdha S. Naik

    2007-01-01

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

  17. Structure of catalase determined by MicroED

    Science.gov (United States)

    Nannenga, Brent L; Shi, Dan; Hattne, Johan; Reyes, Francis E; Gonen, Tamir

    2014-01-01

    MicroED is a recently developed method that uses electron diffraction for structure determination from very small three-dimensional crystals of biological material. Previously we used a series of still diffraction patterns to determine the structure of lysozyme at 2.9 Å resolution with MicroED (Shi et al., 2013). Here we present the structure of bovine liver catalase determined from a single crystal at 3.2 Å resolution by MicroED. The data were collected by continuous rotation of the sample under constant exposure and were processed and refined using standard programs for X-ray crystallography. The ability of MicroED to determine the structure of bovine liver catalase, a protein that has long resisted atomic analysis by traditional electron crystallography, demonstrates the potential of this method for structure determination. DOI: http://dx.doi.org/10.7554/eLife.03600.001 PMID:25303172

  18. Taphonomic evidence for high-speed adapted fins in thunniform ichthyosaurs

    Science.gov (United States)

    Lingham-Soliar, Theagarten; Plodowski, Gerhard

    2007-01-01

    Ichthyosaurs have been compared with the fast-swimming thunniform groups of marine vertebrates, tuna, lamnid sharks, and dolphins, based on similarity of shape of the body and locomotory organs. In addition to shape, high-tensile stiffness of the control surfaces has been shown to be essential in maximizing hydrodynamic efficiency in extant thunniform swimmers. To date, there has been no evidence of a stiffening support system for the dorsal fin and dorsal lobe of the caudal fin in ichthyosaurs, the sole stiffening structure of the ventral lobe being an extension of the vertebral column along its leading edge. Stenopterygius SMF 457 is arguably the best soft-tissue preserved ichthyosaur specimen known. Here, we examine soft-tissue preservation in this specimen in the control surfaces and provide the first evidence of a complex architecture of stiff fibers in the dorsal and caudal fins. We find by comparisons and by analogy that these fibers provided a remarkable mechanism for high tensile stiffness and efficiency of the locomotory organs virtually identical to that of the great white shark, Carcharodon carcharias. It is the first mechanostructural study of the control surfaces of a Jurassic ichthyosaur that adds essential evidence in support of the view that these forms were high-speed thunniform swimmers.

  19. Simple and accurate solution for convective-radiative fin with temperature dependent thermal conductivity using double optimal linearization

    International Nuclear Information System (INIS)

    Bouaziz, M.N.; Aziz, Abdul

    2010-01-01

    A novel concept of double optimal linearization is introduced and used to obtain a simple and accurate solution for the temperature distribution in a straight rectangular convective-radiative fin with temperature dependent thermal conductivity. The solution is built from the classical solution for a pure convection fin of constant thermal conductivity which appears in terms of hyperbolic functions. When compared with the direct numerical solution, the double optimally linearized solution is found to be accurate within 4% for a range of radiation-conduction and thermal conductivity parameters that are likely to be encountered in practice. The present solution is simple and offers superior accuracy compared with the fairly complex approximate solutions based on the homotopy perturbation method, variational iteration method, and the double series regular perturbation method. The fin efficiency expression resembles the classical result for the constant thermal conductivity convecting fin. The present results are easily usable by the practicing engineers in their thermal design and analysis work involving fins.

  20. Experimental Investigation of Temperature Distribution along the Length of Uniform Area Fin for Forced and Free Convection

    Science.gov (United States)

    Kannojiya, Vikas; Sharma, Riya; Gaur, Rahul; Jangra, Anil; Yadav, Pushpender; Prajapati, Pooja

    2018-03-01

    The overheating of an industrial component sometimes may leads to system failure. The convection heat transfer from a heated surface can be effectively enhanced by employing fins on that surface. This Paper emphasizes on the experimental investigation of temperature distribution along the length of pin shaped fin. The analysis is performed on a 100 mm long fin made up of brass with 19.6 mm diameter having thermal conductivity as 111 W/m.K. Temperature at different section of the fin along its length is evaluated experimentally and theoretically. The influence of convection mode viz natural & forced convection and variable heat input on the temperature distribution is evaluated. The result outcomes are then compared with the widely accepted analytical relations. A comparison of convective heat transfer coefficient for uniform and non-uniform area fin is also presented. The results by experimental and analytical method are found to be in good agreement for free convection phenomenon.

  1. A comparative analysis on the shed vortices from the wake of finned, foam-wrapped cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Khashehchi, Morteza [Department of Agro-Technology, College of Aburaihan, University of Tehran, Tehran (Iran, Islamic Republic of); Ashtiani Abdi, Iman; Hooman, Kamel, E-mail: m.khashehchi@ut.ac.ir [School of Mechanical and mining Engineering, University of Queensland, Brisbane (Australia)

    2017-08-15

    The wake characteristics behind a finned and a foam-wrapped circular cylinder has been compared in a study (Khashehchi et al 2014 Exp. Therm. Fluid Sci. 52 328–38) done by the Authors. In this paper, the shed vortices from the wake of the same cylinders have been studied. Shedding in a bluff body has an important effect on increasing the pressure drop downstream of the object. Here, we have used particle image velocimetry to investigate the detached vortices from the wake behind a foam-wrapped and a finned cylinder. The standard case of cross-flow over a bare cylinder, i.e. no surface extension, has also been tested as a benchmark. The experiments have been performed for Reynolds numbers 2000 based on the mean air velocity and the cylinder’s outer diameter. To identify the features of each aforementioned case, linear stochastic estimation has been applied to the velocity fields. Results show that unlike the fin, adding foam to the cylinder surface increases the size of detached vortices and amplifies the core strength. Moreover, foam-wrapped cylinder in contrast to the finned one produces strong three-dimensionality. Interestingly, finned cylinder’s results show less three-dimensionality compared to the bare cylinder. (paper)

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Po-Shun Chuang

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

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

    International Nuclear Information System (INIS)

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

    1974-01-01

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

  5. Hearing of Mr. Francois Roussely, President of EdF

    International Nuclear Information System (INIS)

    Roussely, F.

    2005-01-01

    This document is the proceedings of the hearing of F. Roussely, President of Electricite de France (EdF), at the commission of economic affairs of the French house of commons, about the advisability of the construction of the EPR (European pressurized reactor) demonstration plant and about its possible financing by EdF. In a first part, F. Roussely recalls the European context of deregulation of energy markets and its impact of the French electric power industry (opening of the French market, industrial and social actions of EdF, need of a new generation of nuclear reactor, preservation of EdF's energy mix, warranty of public utility, un-bundling between energy trade and distribution, EdF's turnover and profitability, EdF's foreign daughter companies). In a second part, F. Roussely answers a series of questions asked by the different members of the commission concerning the different points presented in the first part. (J.S.)

  6. An experimental study on the effect of low fin tube geometry on pool boiling of a LiBr solution

    International Nuclear Information System (INIS)

    Kim, Nae Hyun

    2015-01-01

    Pool boiling heat transfer coefficients of a LiBr solution were obtained for seven low fin tubes having different fin pitch and fin height. The test range covered saturation pressure from 7.38kPa to 101.3kPa, heat flux from 20 kW/m 2 to 40 kW/m 2 and LiBr concentration from 0% to 50%. The optimum fin geometry for the present experimental range turned out to be 26 fpi with 0.18 mm fin height.The advantage of added heat transfer area and the disadvantage of slower bubble growth and departure appear to have yielded an optimum fin pitch. The heat transfer coefficient decreased as saturation pressure decreased and Libr concentration increased. The reason may be attributed to the low saturation pressure, which increased the bubble departure diameter and decreased the bubble departure frequency. As the LiBr concen reation increased, the saturation temperature increased and the mass diffusion rate decreased, which resulted in a reduced heat transfer coefficient. The heat transfer coefficients of the low fin tube were greater than those of the smooth tube. Correlations were developed based on the present data

  7. Annular convective-radiative fins with a step change in thickness, and temperature-dependent thermal conductivity and heat transfer coefficient

    Science.gov (United States)

    Barforoush, M. S. M.; Saedodin, S.

    2018-01-01

    This article investigates the thermal performance of convective-radiative annular fins with a step reduction in local cross section (SRC). The thermal conductivity of the fin's material is assumed to be a linear function of temperature, and heat transfer coefficient is assumed to be a power-law function of surface temperature. Moreover, nonzero convection and radiation sink temperatures are included in the mathematical model of the energy equation. The well-known differential transformation method (DTM) is used to derive the analytical solution. An exact analytical solution for a special case is derived to prove the validity of the obtained results from the DTM. The model provided here is a more realistic representation of SRC annular fins in actual engineering practices. Effects of many parameters such as conduction-convection parameters, conduction-radiation parameter and sink temperature, and also some parameters which deal with step fins such as thickness parameter and dimensionless parameter describing the position of junction in the fin on the temperature distribution of both thin and thick sections of the fin are investigated. It is believed that the obtained results will facilitate the design and performance evaluation of SRC annular fins.

  8. The ED use and non-urgent visits of elderly patients

    OpenAIRE

    Gulacti, Umut; Lok, Ugur; Celik, Murat; Aktas, Nurettin; Polat, Haci

    2016-01-01

    Objective: To evaluate the use of the emergency department (ED) by elderly patients, their non-urgent visits and the prevalence of main disease for ED visits. Methods: This cross-sectional study was conducted on patients aged 65 years and over who visited the ED of a tertiary care university hospital in Turkey between January 2015 and January 2016 retrospectively. Results: A total of 36,369 elderly patients who visited the ED were included in the study. The rate of ED visits by elderly patien...

  9. Mixed convection flow of nanofluid in a square enclosure with an intruded rectangular fin

    International Nuclear Information System (INIS)

    Cong, Ran; Zhou, Xuanyu; De Souza Machado, Bruno; Das, Prodip K.

    2016-01-01

    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.

  10. Mixed convection flow of nanofluid in a square enclosure with an intruded rectangular fin

    Energy Technology Data Exchange (ETDEWEB)

    Cong, Ran; Zhou, Xuanyu; De Souza Machado, Bruno; Das, Prodip K., E-mail: prodip.das@ncl.ac.uk [School of Mechanical and Systems Engineering Newcastle University Newcastle upon Tyne, NE1 7RU United Kingdom (United Kingdom)

    2016-07-12

    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.

  11. Mixed convection flow of nanofluid in a square enclosure with an intruded rectangular fin

    Science.gov (United States)

    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. Performance measurement of plate fin heat exchanger by exploration: ANN, ANFIS, GA, and SA

    Directory of Open Access Journals (Sweden)

    A.K. Gupta

    2017-01-01

    Full Text Available An experimental work is conducted on counter flow plate fin compact heat exchanger using offset strip fin under different mass flow rates. The training, testing, and validation set of data has been collected by conducting experiments. Next, artificial neural network merged with Genetic Algorithm (GA utilized to measure the performance of plate-fin compact heat exchanger. The main aim of present research is to measure the performance of plate-fin compact heat exchanger and to provide full explanations. An artificial neural network predicted simulated data, which verified with experimental data under 10–20% error. Then, the authors examined two well-known global search techniques, simulated annealing and the genetic algorithm. The proposed genetic algorithm and Simulated Annealing (SA results have been summarized. The parameters are impartially important for good results. With the emergence of a new data-driven modeling technique, Neuro-fuzzy based systems are established in academic and practical applications. The neuro-fuzzy interference system (ANFIS has also been examined to undertake the problem related to plate-fin heat exchanger performance measurement under various parameters. Moreover, Parallel with ANFIS model and Artificial Neural Network (ANN model has been created with emphasizing the accuracy of the different techniques. A wide range of statistical indicators used to assess the performance of the models. Based on the comparison, it was revealed that technical ANFIS improve the accuracy of estimates in the small pool and tropical ANN.

  13. Relationships between chemical structure, mechanical properties and materials processing in nanopatterned organosilicate fins

    Directory of Open Access Journals (Sweden)

    Gheorghe Stan

    2017-04-01

    Full Text Available The exploitation of nanoscale size effects to create new nanostructured materials necessitates the development of an understanding of relationships between molecular structure, physical properties and material processing at the nanoscale. Numerous metrologies capable of thermal, mechanical, and electrical characterization at the nanoscale have been demonstrated over the past two decades. However, the ability to perform nanoscale molecular/chemical structure characterization has only been recently demonstrated with the advent of atomic-force-microscopy-based infrared spectroscopy (AFM-IR and related techniques. Therefore, we have combined measurements of chemical structures with AFM-IR and of mechanical properties with contact resonance AFM (CR-AFM to investigate the fabrication of 20–500 nm wide fin structures in a nanoporous organosilicate material. We show that by combining these two techniques, one can clearly observe variations of chemical structure and mechanical properties that correlate with the fabrication process and the feature size of the organosilicate fins. Specifically, we have observed an inverse correlation between the concentration of terminal organic groups and the stiffness of nanopatterned organosilicate fins. The selective removal of the organic component during etching results in a stiffness increase and reinsertion via chemical silylation results in a stiffness decrease. Examination of this effect as a function of fin width indicates that the loss of terminal organic groups and stiffness increase occur primarily at the exposed surfaces of the fins over a length scale of 10–20 nm. While the observed structure–property relationships are specific to organosilicates, we believe the combined demonstration of AFM-IR with CR-AFM should pave the way for a similar nanoscale characterization of other materials where the understanding of such relationships is essential.

  14. Inverse scaling trends for charge-trapping-induced degradation of FinFETs performance

    OpenAIRE

    Amoroso, Salvatore Maria; Georgiev, Vihar P.; Gerrer, Louis; Towie, Ewan; Wang, Xingsheng; Riddet, Craig; Brown, Andrew Robert; Asenov, Asen

    2014-01-01

    In this paper, we investigate the impact of a single discrete charge trapped at the top oxide interface on the performance of scaled nMOS FinFET transistors. The charge-trapping-induced gate voltage shift is simulated as a function of the device scaling and for several regimes of conduction-from subthreshold to ON-state. Contrary to what is expected for planar MOSFETs, we show that the trap impact decreases with scaling down the FinFET size and the applied gate voltage. By comparing drift-dif...

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

    Directory of Open Access Journals (Sweden)

    Shannon N. Barry

    2017-12-01

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

  16. Efficiency analysis of straight fin with variable heat transfer coefficient and thermal conductivity

    International Nuclear Information System (INIS)

    Sadri, Somayyeh; Raveshi, Mohammad Reza; Amiri, Shayan

    2012-01-01

    In this study, one type of applicable analytical method, differential transformation method (DTM), is used to evaluate the efficiency and behavior of a straight fin with variable thermal conductivity and heat transfer coefficient. Fins are widely used to enhance heat transfer between primary surface and the environment in many industrial applications. The performance of such a surface is significantly affected by variable thermal conductivity and heat transfer coefficient, particularly for large temperature differences. General heat transfer equation related to the fin is derived and dimensionalized. The concept of differential transformation is briefly introduced, and then this method is employed to derive solutions of nonlinear equations. Results are evaluated for several cases such as: laminar film boiling or condensation, forced convection, laminar natural convection, turbulent natural convection, nucleate boiling, and radiation. The obtained results from DTM are compared with the numerical solution to verify the accuracy of the proposed method. The effects of design parameters on temperature and efficiency are evaluated by some figures. The major aim of the present study, which is exclusive for this article, is to find the effect of the modes of heat transfer on fin efficiency. It has been shown that for radiation heat transfer, thermal efficiency reaches its maximum value

  17. The Impact of "ED" on Educational Research.

    Science.gov (United States)

    Florio, David H.

    1980-01-01

    The purposes, structure, and component parts of the newly formed Department of Education (ED) organizations from which educational research programs will be administered are discussed. As the climate surrounding ED changes, opportunities to take advantage of the elevated status of research will be presented. (Author/RL)

  18. Emergency Department (ED, ED Observation, Day Hospital, and Hospital Admissions for Adults with Sickle Cell Disease

    Directory of Open Access Journals (Sweden)

    Susan Silva

    2018-02-01

    Full Text Available Introduction: Use of alternative venues to manage uncomplicated vaso-occlusive crisis (VOC, such as a day hospital (DH or ED observation unit, for patients with sickle cell anemia, may significantly reduce admission rates, which may subsequently reduce 30-day readmission rates. Methods: In the context of a two-institution quality improvement project to implement best practices for management of patients with sickle cell disease (SCD VOC, we prospectively compared acute care encounters for utilization of 1 emergency department (ED; 2 ED observation unit; 3 DH, and 4 hospital admission, of two different patient cohorts with SCD presenting to our two study sites. Using a representative sample of patients from each institution, we also tabulated SCD patient visits or admissions to outside hospitals within 20 miles of the patients’ home institutions. Results: Over 30 months 427 patients (297 at Site 1 and 130 at Site 2 initiated 4,740 institutional visits, totaling 6,627 different acute care encounters, including combinations of encounters. The range of encounters varied from a low of 0 (203 of 500 patients [40.6%] at Site 1; 65 of 195 patients [33.3%] at Site 2, and a high of 152 (5/month acute care encounters for one patient at Site 2. Patients at Site 2 were more likely to be admitted to the hospital during the study period (88.4% vs. 74.4%, p=0.0011 and have an ED visit (96.9% vs. 85.5%, p=0.0002. DH was used more frequently at Site 1 (1.207 encounters for 297 patients at Site 1, vs. 199 encounters for 130 patients at Site 2, and ED observation was used at Site 1 only. Thirty-five percent of patients visited hospitals outside their home academic center. Conclusion: In this 30-month assessment of two sickle cell cohorts, healthcare utilization varied dramatically between individual patients. One cohort had more hospital admissions and ED encounters, while the other cohort had more day hospital encounters and used a sickle cell disease

  19. Estrabismo após toxina botulínica para fins estéticos

    Directory of Open Access Journals (Sweden)

    Marta Halfeld Ferrari Alves Lacordia

    2011-06-01

    Full Text Available RESUMO Nas últimas décadas, a toxina botulínica tem sido aplicada para fins terapêuticos em inúmeras afecções. A toxina do tipo A foi aprovada primeiramente em 1989 para o uso em estrabismo, blefaroespasmo e espasmo hemifacial de pacientes maiores que 12 anos de idade. A observação de que pacientes tratados de blefaroespasmo com toxina botulínica apresentavam um efeito adicional de diminuição das rugas de expressão inspirou estudos sobre a aplicação cosmética da toxina. Recentemente, a toxina botulínica do tipo A foi aprovada para fins estéticos. Este trabalho relata um caso de ocorrência de estrabismo após aplicação de toxina botulínica na face para fins estéticos.

  20. Copper vertical micro dendrite fin arrays and their superior boiling heat transfer capability

    Science.gov (United States)

    Wang, Ya-Qiao; Lyu, Shu-Shen; Luo, Jia-Li; Luo, Zhi-Yong; Fu, Yuan-Xiang; Heng, Yi; Zhang, Jian-Hui; Mo, Dong-Chuan

    2017-11-01

    Micro pin fin arrays have been widely used in electronic cooling, micro reactors, catalyst support, and wettability modification and so on, and a facile way to produce better micro pin fin arrays is demanded. Herein, a simple electrochemical method has been developed to fabricate copper vertical micro dendrite fin arrays (Cu-VMDFA) with controllable shapes, number density and height. High copper sulphate concentration is one key point to make the dendrite stand vertically. Besides, the applied current should rise at an appropriate rate to ensure the copper dendrite can grow vertically on its own. The Cu-VMDFA can significantly enhance the heat transfer coefficient by approximately twice compared to the plain copper surface. The Cu-VMDFA may be widely used in boiling heat transfer areas such as nuclear power plants, electronic cooling, heat exchangers, and so on.

  1. FinFET centric variability-aware compact model extraction and generation technology supporting DTCO

    OpenAIRE

    Wang, Xingsheng; Cheng, Binjie; Reid, David; Pender, Andrew; Asenov, Plamen; Millar, Campbell; Asenov, Asen

    2015-01-01

    In this paper, we present a FinFET-focused variability-aware compact model (CM) extraction and generation technology supporting design-technology co-optimization. The 14-nm CMOS technology generation silicon on insulator FinFETs are used as testbed transistors to illustrate our approach. The TCAD simulations include a long-range process-induced variability using a design of experiment approach and short-range purely statistical variability (mismatch). The CM extraction supports a hierarchical...

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

    Science.gov (United States)

    Weirathmueller, Maria Michelle Josephine

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

  3. Results from the FIN-2 formal comparison

    Science.gov (United States)

    Connolly, Paul; Hoose, Corinna; Liu, Xiaohong; Moehler, Ottmar; Cziczo, Daniel; DeMott, Paul

    2017-04-01

    During the Fifth International Ice Nucleation Workshop (FIN-2) at the AIDA Ice Nucleation facility in Karlsruhe, Germany in March 2015, a formal comparison of ice nucleation measurement methods was conducted. During the experiments the samples of ice nucleating particles were not revealed to the instrument scientists, hence this was referred to as a "blind comparison". The two samples used were later revealed to be Arizona Test Dust and an Argentina soil sample. For these two samples seven mobile ice nucleating particle counters sampled directly from the AIDA chamber or from the aerosol preparation chamber at specified temperatures, whereas filter samples were taken for two offline deposition nucleation instruments. Wet suspension methods for determining IN concentrations were also used with 10 different methods employed. For the wet suspension methods experiments were conducted using INPs collected from the air inside the chambers (impinger sampling) and INPs taken from the bulk samples (vial sampling). Direct comparisons of the ice nucleating particle concentrations are reported as well as derived ice nucleation active site densities. The study highlights the difficulties in performing such analyses, but generally indicates that there is reasonable agreement between the wet suspension techniques. It is noted that ice nucleation efficiency derived from the AIDA chamber (quantified using the ice active surface site density approach) is higher than that for the cold stage techniques. This is both true for the Argentina soil sample and, to a lesser extent, for the Arizona Test Dust sample too. Other interesting effects were noted: for the ATD the impinger sampling demonstrated higher INP efficiency at higher temperatures (>255 K) than the vial sampling, but agreed at the lower temperatures (<255K), whereas the opposite was true for the Argentina soil sample. The results are analysed to better understand the performance of the various techniques and to address any

  4. Out-of-Plane Strain Effects on Physically Flexible FinFET CMOS

    KAUST Repository

    Ghoneim, Mohamed T.

    2016-05-18

    We present a comprehensive electrical performance assessment of hafnium silicate (HfSiOₓ) high-κ dielectric and titanium-nitride (TiN) metal-gate-integrated FinFET-based complementary-metal-oxide-semiconductor (CMOS) on flexible silicon on insulator. The devices were fabricated using the state-of-the-art CMOS technology and then transformed into flexible form by using a CMOS-compatible maskless deep reactive-ion etching technique. Mechanical out-of-plane stresses (compressive and tensile) were applied along and across the transistor channel lengths through a bending range of 0.5-5 cm radii for n-type and p-type FinFETs. Electrical measurements were carried out before and after bending, and all the bending measurements were taken in the actual flexed (bent) state to avoid relaxation and stress recovery. Global stress from substrate bending affects the devices in different ways compared with the well-studied uniaxial/biaxial localized strain. The global stress is dependent on the type of channel charge carriers, the orientation of the bending axis, and the physical gate length of the device. We, therefore, outline useful insights on the design strategies of flexible FinFETs in future free-form electronic applications.

  5. Hydrodynamics of a robotic fish tail: effects of the caudal peduncle, fin ray motions and the flow speed.

    Science.gov (United States)

    Ren, Ziyu; Yang, Xingbang; Wang, Tianmiao; Wen, Li

    2016-02-08

    Recent advances in understanding fish locomotion with robotic devices have included the use of biomimetic flapping based and fin undulatory locomotion based robots, treating two locomotions separately from each other. However, in most fish species, patterns of active movements of fins occur in concert with the body undulatory deformation during swimming. In this paper, we describe a biomimetic robotic caudal fin programmed with individually actuated fin rays to mimic the fin motion of the Bluegill Sunfish (Lepomis macrochirus) and coupled with heave and pitch oscillatory motions adding to the robot to mimic the peduncle motion which is derived from the undulatory fish body. Multiple-axis force and digital particle image velocimetry (DPIV) experiments from both the vertical and horizontal planes behind the robotic model were conducted under different motion programs and flow speeds. We found that both mean thrust and lift could be altered by changing the phase difference (φ) from 0° to 360° between the robotic caudal peduncle and the fin ray motion (spanning from 3 mN to 124 mN). Notably, DPIV results demonstrated that the caudal fin generated multiple wake flow patterns in both the vertical and horizontal planes by varying φ. Vortex jet angle and thrust impulse also varied significantly both in these two planes. In addition, the vortex shedding position along the spanwise tail direction could be shifted around the mid-sagittal position between the upper and lower lobes by changing the phase difference. We hypothesize that the fish caudal fin may serve as a flexible vectoring propeller during swimming and may be critical for the high maneuverability of fish.

  6. Discipline, availability of electronic resources and the use of Finnish National Electronic Library - FinELib

    Directory of Open Access Journals (Sweden)

    Sanna Torma

    2004-01-01

    Full Text Available This study elaborated relations between digital library use by university faculty, users' discipline and the availability of key resources in the Finnish National Electronic Library (FinELib, Finnish national digital library, by using nationwide representative survey data. The results show that the perceived availability of key electronic resources by researchers in FinELib was a stronger predictor of the frequency and purpose of use of its services than users' discipline. Regardless of discipline a good perceived provision of central resources led to a more frequent use of FinELib. The satisfaction with the services did not vary with the discipline, but with the perceived availability of resources.

  7. Pdlim7 is required for maintenance of the mesenchymal/epidermal Fgf signaling feedback loop during zebrafish pectoral fin development

    Directory of Open Access Journals (Sweden)

    Klosowiak Julian

    2010-10-01

    Full Text Available Abstract Background Vertebrate limb development involves a reciprocal feedback loop between limb mesenchyme and the overlying apical ectodermal ridge (AER. Several gene pathways participate in this feedback loop, including Fgf signaling. In the forelimb lateral plate mesenchyme, Tbx5 activates Fgf10 expression, which in turn initiates and maintains the mesenchyme/AER Fgf signaling loop. Recent findings have revealed that Tbx5 transcriptional activity is regulated by dynamic nucleocytoplasmic shuttling and interaction with Pdlim7, a PDZ-LIM protein family member, along actin filaments. This Tbx5 regulation is critical in heart formation, but the coexpression of both proteins in other developing tissues suggests a broader functional role. Results Knock-down of Pdlim7 function leads to decreased pectoral fin cell proliferation resulting in a severely stunted fin phenotype. While early gene induction and patterning in the presumptive fin field appear normal, the pectoral fin precursor cells display compaction and migration defects between 18 and 24 hours post-fertilization (hpf. During fin growth fgf24 is sequentially expressed in the mesenchyme and then in the apical ectodermal ridge (AER. However, in pdlim7 antisense morpholino-treated embryos this switch of expression is prevented and fgf24 remains ectopically active in the mesenchymal cells. Along with the lack of fgf24 in the AER, other critical factors including fgf8 are reduced, suggesting signaling problems to the underlying mesenchyme. As a consequence of perturbed AER function in the absence of Pdlim7, pathway components in the fin mesenchyme are misregulated or absent, indicating a breakdown of the Fgf signaling feedback loop, which is ultimately responsible for the loss of fin outgrowth. Conclusion This work provides the first evidence for the involvement of Pdlim7 in pectoral fin development. Proper fin outgrowth requires fgf24 downregulation in the fin mesenchyme with subsequent

  8. Aluminum fin-stock alloys

    International Nuclear Information System (INIS)

    Gul, R.M.; Mutasher, F.

    2007-01-01

    Aluminum alloys have long been used in the production of heat exchanger fins. The comparative properties of the different alloys used for this purpose has not been an issue in the past, because of the significant thickness of the finstock material. However, in order to make fins lighter in weight, there is a growing demand for thinner finstock materials, which has emphasized the need for improved mechanical properties, thermal conductivity and corrosion resistance. The objective of this project is to determine the effect of iron, silicon and manganese percentage increment on the required mechanical properties for this application by analyzing four different aluminum alloys. The four selected aluminum alloys are 1100, 8011, 8079 and 8150, which are wrought non-heat treatable alloys with different amount of the above elements. Aluminum alloy 1100 serve as a control specimen, as it is commercially pure aluminum. The study also reports the effect of different annealing cycles on the mechanical properties of the selected alloys. Metallographic examination was also preformed to study the effect of annealing on the precipitate phases and the distribution of these phases for each alloy. The microstructure analysis of the aluminum alloys studied indicates that the precipitated phase in the case of aluminum alloys 1100 and 8079 is beta-FeAI3, while in 8011 it is a-alfa AIFeSi, and the aluminum alloy 8150 contains AI6(Mn,Fe) phase. The comparison of aluminum alloys 8011 and 8079 with aluminum alloy 1100 show that the addition of iron and silicon improves the percent elongation and reduces strength. The manganese addition increases the stability of mechanical properties along the annealing range as shown by the comparison of aluminum alloy 8150 with aluminum alloy 1100. Alloy 8150 show superior properties over the other alloys due to the reaction of iron and manganese, resulting in a preferable response to thermal treatment and improved mechanical properties. (author)

  9. EDS Coal Liquefaction Process Development. Phase V. Laboratory evaluation of the characteristics of EDS Illinois bottoms

    Energy Technology Data Exchange (ETDEWEB)

    Lao, T C; Levasseur, A A

    1984-02-01

    This interim report documents work carried out by Combustion Engineering, Inc. under a contract to Exxon Research and Engineering Company to develop a conceptual Hybrid Boiler design fueled by the vacuum distillation residue (vacuum bottoms) derived from Illinois No. 6 coal in the EDS Coal Liquefaction Process. This report was prepared by Combustion Engineering, Inc., and is the first of two reports on the predevelopment phase of the Hybrid Boiler program. This report covers the results of a laboratory investigation to assess the fuel and ash properties of EDS vacuum bottoms. The results of the laboratory testing reported here were used in conjunction with Combustion Engineering's design experience to predict fuel performance and to develop appropriate boiler design parameters. These boiler design parameters were used to prepare the engineering design study reported in EDS Interim Report FE-2893-113, the second of the two reports on the predevelopment phase of the Hybrid Boiler Program. 46 figures, 29 tables.

  10. Fast breeder cladding tubes provided with helical fins

    International Nuclear Information System (INIS)

    Baumgaertner, E.; Hoffmann, H.; Miller, H.; Jacobi, O.; Bojarski, E.; Freund, D.; Reiser, H.

    1977-04-01

    Development of fast breeder tubes with helical fins started around 1966. The development was initiated mainly by the search for a more favorable alternative to the conventional spacers such as grids and spiral wires. First of all the possibility was investigated of fabricating them on an industrial scale. The first thermohydraulic and fluiddynamic tests were made in parallel by AEG, GfK and Interatom. Besides the possibility of industrial fabrication the problems of non-destructive testing for geometry and material defects had to be treated with priority. In this report the different stages of development are shown and, finally, two rather large projects are described. These projects are the study ready for the licensing procedure concerning the irradiation of finned tube oxide fuel elements in KNK II and the already completed 19-rod fuel element bundle irradiation experiment Mol 7D of GfK performed in the 500 kW sodium loop of the Belgian BR2 reactor. In this BR2 experiment the maximum target burnup of 85,000 MWd/t of oxide was attained without trouble. (orig.) [de

  11. An experimental investigation on air-side performances of finned tube heat exchangers for indirect air-cooling tower

    Directory of Open Access Journals (Sweden)

    Du Xueping

    2014-01-01

    Full Text Available A tremendous quantity of water can be saved if the air cooling system is used, comparing with the ordinary water-cooling technology. In this study, two kinds of finned tube heat exchangers in an indirect air-cooling tower are experimentally studied, which are a plain finned oval-tube heat exchanger and a wavy-finned flat-tube heat exchanger in a cross flow of air. Four different air inlet angles (90°, 60 °, 45°, and 30° are tested separately to obtain the heat transfer and resistance performance. Then the air-side experimental correlations of the Nusselt number and friction factor are acquired. The comprehensive heat transfer performances for two finned tube heat exchangers under four air inlet angles are compared. For the plain finned oval-tube heat exchanger, the vertical angle (90° has the worst performance while 45° and 30° has the best performance at small ReDc and at large ReDc, respectively. For the wavy-finned flat-tube heat exchanger, the worst performance occurred at 60°, while the best performance occurred at 45° and 90° at small ReDc and at large ReDc, respectively. From the comparative results, it can be found that the air inlet angle has completely different effects on the comprehensive heat transfer performance for the heat exchangers with different structures.

  12. Experimental analysis on frosting characteristic of SK-type finned refrigerating heat exchanger with large-diameter circular holes

    International Nuclear Information System (INIS)

    Fang, Zhao-song; Wang, Hou-hua; Zhang, Jie; Wu, Wei-wei

    2014-01-01

    This paper presents the construction of both a plane fin-and-tube heat exchanger and a SK-type fin-and-tube heat exchanger. Based on plane fin-and-tube heat exchanger, comparative industrial prototype experiments of SK-type fin-and-tube heat exchanger energy efficiency performance were carried out in the artificial climate chamber. Test results confirmed several findings: when the amount of the refrigerant charged is the same and face velocity u = 3.75 m s −1 , SK-type fin-and-tube heat exchanger refrigeration capacity increases by an average of 9.13%; energy consumption reduces by an average of 11.25%, coefficient of performance (COP) of heat exchanger increases by an average of 22.65% with continuous operation during the first 2 h. Also, when the operation time exceeds 2 h, the COP of both types of heat exchangers are both less than 0.6, illustrating that under frost conditions, the defrost interval should not be too long, otherwise energy consumption may sharply spike. - Highlights: •The large holes of SK-type induced the generation of turbulence flow. •The refrigeration capacity and COP of SK-type exceeds that of plane one. •The SK-type fin-and-tube heat exchanger is a new kind of heat transfer equipment. •The defrost interval should not exceed 2 h under frost conditions

  13. Exploring the relationship between general practice characteristics, and attendance at walk-in centres, minor injuries units and EDs in England 2012/2013: a cross-sectional study.

    Science.gov (United States)

    Tammes, Peter; Morris, Richard W; Brangan, Emer; Checkland, Kath; England, Helen; Huntley, Alyson; Lasserson, Daniel; MacKichan, Fiona; Salisbury, Chris; Wye, Lesley; Purdy, Sarah

    2016-10-01

    For several years, EDs in the UK NHS have faced considerable increases in attendance rates. Walk-in centres (WiCs) and minor injuries units (MIUs) have been suggested as solutions. We aimed to investigate the associations between practice and practice population characteristics with ED attendance rates or combined ED/WiC/MIU attendance, and the associations between WiC/MIU and ED attendance. We used general practice-level data including 7462 English practices in 2012/2013 and present adjusted regression coefficients from linear multivariable analysis for relationships between patients' emergency attendance rates and practice characteristics. Every percentage-point increase in patients reporting inability to make an appointment was associated with an increase in emergency attendance by 0.36 (95% CI 0.06 to 0.66) per 1000 population. Percentage-point increases in patients unable to speak to a general practitioner (GP)/nurse within two workdays and patients able to speak often to their preferred GP were associated with increased emergency attendance/1000 population by 0.23 (95% CI 0.05 to 0.42) and 0.10 (95% CI 0.00 to 0.19), respectively. Practices in areas encompassing several towns (conurbations) had higher attendance than rural practices, as did practices with more non-UK-qualified GPs. Practice population characteristics associated with increased emergency attendance included higher unemployment rates, higher percentage of UK whites and lower male life expectancy, which showed stronger associations than practice characteristics. Furthermore, higher MIU or WiC attendance rates were associated with lower ED attendance rates. Improving availability of appointments and opportunities to speak a GP/nurse at short notice might reduce ED attendance. Establishing MIUs and WiCs might also reduce ED attendance. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  14. Transient heat transfer in longitudinal fins of various profiles with ...

    Indian Academy of Sciences (India)

    School of Computational and Applied Mathematics, University of the Witwatersrand, ... by frequent encounters of fin problems in many engineering applications to enhance heat transfer. In recent .... where β is the thermal conductivity gradient.

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

    Science.gov (United States)

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

    2016-01-01

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

  16. Species composition of the international shark fin trade assessed through a retail-market survey in Hong Kong.

    Science.gov (United States)

    Fields, Andrew T; Fischer, Gunter A; Shea, Stanley K H; Zhang, Huarong; Abercrombie, Debra L; Feldheim, Kevin A; Babcock, Elizabeth A; Chapman, Demian D

    2018-04-01

    The shark fin trade is a major driver of shark exploitation in fisheries all over the world, most of which are not managed on a species-specific basis. Species-specific trade information highlights taxa of particular concern and can be used to assess the efficacy of management measures and anticipate emerging threats. The species composition of the Hong Kong Special Administrative Region of China, one of the world's largest fin trading hubs, was partially assessed in 1999-2001. We randomly selected and genetically identified fin trimmings (n = 4800), produced during fin processing, from the retail market of Hong Kong in 2014-2015 to assess contemporary species composition of the fin trade. We used nonparametric species estimators to determine that at least 76 species of sharks, batoids, and chimaeras supplied the fin trade and a Bayesian model to determine their relative proportion in the market. The diversity of traded species suggests species substitution could mask depletion of vulnerable species; one-third of identified species are threatened with extinction. The Bayesian model suggested that 8 species each comprised >1% of the fin trimmings (34.1-64.2% for blue [Prionace glauca], 0.2-1.2% for bull [Carcharhinus leucas] and shortfin mako [Isurus oxyrinchus]); thus, trade was skewed to a few globally distributed species. Several other coastal sharks, batoids, and chimaeras are in the trade but poorly managed. Fewer than 10 of the species we modeled have sustainably managed fisheries anywhere in their range, and the most common species in trade, the blue shark, was not among them. Our study and approach serve as a baseline to track changes in composition of species in the fin trade over time to better understand patterns of exploitation and assess the effects of emerging management actions for these animals. © 2017 The Authors. Conservation Biology published by Wiley Periodicals, Inc. on behalf of Society for Conservation Biology.

  17. The role of tip deflection on the thrust produced by rigid flapping fins

    Science.gov (United States)

    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.

  18. Heat transfer augmentation along the tube wall of a louvered fin heat exchanger using practical delta winglets

    Energy Technology Data Exchange (ETDEWEB)

    Lawson, Michael J.; Thole, Karen A. [Mechanical and Nuclear Engineering Department, The Pennsylvania State University, University Park, PA 16802 (United States)

    2008-05-15

    Delta winglets are known to induce the formation of streamwise vortices and increase heat transfer between a working fluid and the surface on which the winglets are placed. This study investigates the use of delta winglets to augment heat transfer on the tube surface of louvered fin heat exchangers. It is shown that delta winglets placed on louvered fins produce augmentations in heat transfer along the tube wall as high as 47% with a corresponding increase of 19% in pressure losses. Manufacturing constraints are considered in this study whereby piercings in the louvered fins resulting from stamping the winglets into the louvered fins are simulated. Comparisons of measured heat transfer coefficients with and without piercings indicate that piercings reduce average heat transfer augmentations, but significant increases still occur with respect to no winglets present. (author)

  19. Numerical model of a thermoelectric generator with compact plate-fin heat exchanger for high temperature PEM fuel cell exhaust heat recovery

    DEFF Research Database (Denmark)

    Xin, Gao; Andreasen, Søren Juhl; Chen, Min

    2012-01-01

    on a finite-element approach. On each discretized segment, fluid properties, heat transfer process and TEG performance are locally calculated for higher model precision. To benefit both the system design and fabrication, the way to model TEG modules is herein reconsidered; a database of commercialized compact......This paper presents a numerical model of an exhaust heat recovery system for a high temperature polymer electrolyte membrane fuel cell (HTPEMFC) stack. The system is designed as thermoelectric generators (TEGs) sandwiched in the walls of a compact plate-fin heat exchanger. Its model is based...... plate-fin heat exchangers is adopted. Then the model is validated against experimental data and the main variables are identified by means of a sensitivity analysis. Finally, the system configuration is optimized for recovering heat from the exhaust gas. The results exhibit the crucial importance...

  20. Ed overcrowding – matematic models for integrated solutions and decisions

    OpenAIRE

    ROTARU, LUCIANA TEODORA; BĂNICIOIU - COVEI, MIHAI

    2017-01-01

    Dear Editor In Chief, We are writing to You in line with an very interesting point of view regarding the Emergency Department (ED) development. The paper titled Improving Emergency Department Capacity Efficiency, published in your Journal 2016; 12(1): 52- 57, as an original articles, spotlight solution for ED crowding. So we are proposing a mathematics models for reciprocal accommodation of patients flows to the response capacity of the ED. ED overcrowding ...

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-07-01

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

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

    Science.gov (United States)

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

    2017-08-15

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

  4. Enhanced heat transfer in partially open square cavities with thin fin by using electric field

    International Nuclear Information System (INIS)

    Kasayapanand, N.; Kiatsiriroat, T.

    2009-01-01

    Numerical modeling of the electric field effect on the natural convection in the partially open square cavities with thin fin attached is investigated. The interactions among electric, flow, and temperature fields are analyzed by using a computational fluid dynamics technique. It is found that the flow and heat transfer enhancements are a decreasing function of the Rayleigh number. Moreover, the volume flow rate and heat transfer coefficient are substantially improved by electrohydrodynamic especially at low aperture size, high aperture position, and high inclined angle. Surprisingly, the maximum convective heat transfer is obtained at the minimum electrical energy consumption by placing electrodes at a suitable position. The optimum electrode arrangements for both single fin and multiple fins are also achieved

  5. Multiphysics Numerical Modeling of a Fin and Tube Heat Exchanger

    DEFF Research Database (Denmark)

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

    2015-01-01

    In the present research work, a modeling effort to predict the performance of a liquid-gas type fin and tube heat exchanger design is made. Three dimensional (3D) steady state numerical model is developed using commercial software COMSOL Multiphysics based on finite element method (FEM......). For the purposes here, only gas flowing over the fin side is simulated assuming constant inner tube wall temperature. The study couples conjugate heat transfer mechanism with turbulent flow in order to describe the temperature and velocity profile. In addition, performance characteristics of the heat exchanger...... design in terms of heat transfer and pressure loss are determined by parameters such as overall heat transfer coefficient, Colburn j-factor, flow resistance factor, and efficiency index. The model provides useful insights necessary for optimization of heat exchanger design....

  6. Response surface method optimization of V-shaped fin assisted latent heat thermal energy storage system during discharging process

    Directory of Open Access Journals (Sweden)

    Sina Lohrasbi

    2016-09-01

    Full Text Available Latent Heat Thermal Energy Storage Systems (LHTESS containing Phase Change Material (PCM are used to establish balance between energy supply and demand. PCMs have high latent heat but low thermal conductivity, which affects their heat transfer performance. In this paper, a novel fin array has been optimized by multi-objective Response Surface Method (RSM based on discharging process of PCM, and then this fin configuration is applied on LHTESS, and comparison between full discharging time by applying this fin array and LHTESS with other fin structures has been carried out. The employed numerical method in this paper is Standard Galerkin Finite Element Method. Adaptive grid refinement is used to solve the equations. Since the enhancement technique, which has been employed in the present study reduces the employed PCM mass, maximum energy storage capacity variations have been considered. Therefore phase change expedition and maximum energy storage capacity have been considered as the objectives of optimization and the importance of second objective is indicated which is proposed as the novelty here. Results indicate that considering maximum energy storage capacity as the objective of optimization procedure leads to efficient shape design of LHTESS. Also employing optimized V-shaped fin in LHTESS, expedites discharging process considerably in comparison with the LHTESS without fin.

  7. Electrostatic-Dipole (ED) Fusion Confinement Studies

    Science.gov (United States)

    Miley, George H.; Shrestha, Prajakti J.; Yang, Yang; Thomas, Robert

    2004-11-01

    The Electrostatic-Dipole (ED) concept significantly differs from a "pure" dipole confinement device [1] in that the charged particles are preferentially confined to the high-pressure region interior of the dipole coil by the assistance of a surrounding spherical electrostatic grid. In present ED experiments, a current carrying coil is embedded inside the grid of an IEC such as to produce a magnetic dipole field. Charged particles are injected axisymmetrically from an ion gun (or duo-plasmatron) into the center of the ED confinement grid/dipole ring where they oscillate along the magnetic field lines and pass the peak field region at the center of the dipole region. As particles begin accelerating away from the center region towards the outer electrostatic grid region, they encounter a strong electrostatic potential (order of 10's of kilovolts) retarding force. The particles then decelerate, reverse direction and re-enter the dipole field region where again magnetic confinement dominates. This process continues, emulating a complex harmonic oscillator motion. The resulting pressure profile averaged over the field curvature offers good plasma stability in the ED configuration. The basic concept and results from preliminary experiments will be described. [1] M.E. Mauel, et al. "Dipole Equilibrium and Stability," 18th IAEA Conference of Plasma Phys. and Control. Nuclear Fusion, Varenna, Italy 2000, IAEA-F1-CN-70/TH

  8. Fin efficiency in 2D with convection at the tip and dissymmetry of exchange

    International Nuclear Information System (INIS)

    Bouaziz, Najib

    2009-01-01

    To determine the overall effective surface in the heat exchangers, it is necessary to know the fin efficiency accurately. An analytical formula, taking into account the convective heat at the tip and an unequal exchange in 2D case is derived. Some differences were found between 1D and our expression. The dissymmetry of exchange has a strong effect on the fin efficiency and convection at the tip cannot be ignored.

  9. Computer-Aided Simulations of Convective Heat Transfer in a Wedged Channel with Pin-Fins at Various Outlet Arrangements and Nonuniform Diameters

    Directory of Open Access Journals (Sweden)

    Qitao Zhou

    2013-01-01

    Full Text Available The turbine blade works at high thermal loads, especially the trailing edge of the blade due to the hot gas leakage flow. Pin-fins are well recognized as a kind of effective device to augment the convective heat transfer and effectively cool the trailing edge. In this paper, the cooling effectiveness of chordwise outlet pin-fins distance and inner pin fin diameter is, respectively, studied on the heat transfer and flow friction of the trailing edge of the blade with software CFX. A 90 deg turn cooling wedge passage with cylindrical pin-fins is used to model the trailing edge. Results show that the pin-fins distance at the outlet and the arithmetic arrangement of the inner pin-fins diameter both are vital factors to influence the cooling effectiveness in the trailing edge of the blade.

  10. A Numerical Study on Heat Transfer and Flow Characteristics of a Finned Downhole Coaxial Heat Exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Park, Chun Dong; Lee, Dong Hyun; Park, Byung-Sik; Choi, Jaejoon [Korea Institute of Energy Research (KIER), Daejeon (Korea, Republic of)

    2017-02-15

    In this study, the flow and heat transfer characteristics of the finned annular passage were investigated numerically. The annular passage simulates co-axial geothermal heat exchanger, and fins are installed on its inner wall to reduce heat loss from the production passage (annulus) to injection passage (inner pipe). A commercial CFD program, Ansys Fluent, was used with SST k-ω turbulence model. The effects of the geometric parameters of the fin on the inner tube were analyzed under the periodic boundary condition. The result indicated that most parameters had a tendency to increase with an increase in the height and angle of the fin. However, it was confirmed that the Nusselt number of the inner tube on the coaxial 15, 5, 0.3 was lower than that of the smooth tube. Additionally, the Nusselt number of the inner tube exhibited a tendency of decreasing with a decrease in the spacing in Coaxial 15, S{sub f}, 0.3.

  11. High temperature study of flexible silicon-on-insulator fin field-effect transistors

    KAUST Repository

    Diab, Amer El Hajj

    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 (Ids), gate leakage current (Igs), transconductance (gm), and extracted low-field mobility (μ0). 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.

  12. Is the case-mix of patients who self-present to ED similar to general practice and other acute-care facilities?

    Science.gov (United States)

    Harris, Tim; McDonald, Keith

    2014-12-01

    To benchmark walk-in presentations to emergency departments (ED) with those presenting to other local acute healthcare facilities. A large teaching hospital with an annual ED census of 140, 000 adult patients and surrounding associated acute healthcare providers. A random sample of 384 patients who self-presented to the ED was obtained. Benchmarking data were drawn from two general practices; the Tower Hamlets Community Services walk-in centre (co-located on-site with the ED) and the GP-run out-of-hours service. The case-mix presenting to the ED was characterised by a higher proportion of injuries and chest pain, but fewer simple infections and non-traumatic musculoskeletal conditions as compared to other acute care facilities in our region. Patients with injuries and possible cardiac chest pain were more likely to attend the ED, and those with infection or musculoskeletal problems less likely, as compared with other acute healthcare facilities. The population presenting to the ED is distinct from that presenting to general practice, out-of-hours clinics, or walk-in centres. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  13. Batoid locomotion: effects of speed on pectoral fin deformation in the little skate, Leucoraja erinacea.

    Science.gov (United States)

    Di Santo, Valentina; Blevins, Erin L; Lauder, George V

    2017-02-15

    Most batoids have a unique swimming mode in which thrust is generated by either oscillating or undulating expanded pectoral fins that form a disc. Only one previous study of the freshwater stingray has quantified three-dimensional motions of the wing, and no comparable data are available for marine batoid species that may differ considerably in their mode of locomotion. Here, we investigate three-dimensional kinematics of the pectoral wing of the little skate, Leucoraja erinacea , swimming steadily at two speeds [1 and 2 body lengths (BL) s -1 ]. We measured the motion of nine points in three dimensions during wing oscillation and determined that there are significant differences in movement amplitude among wing locations, as well as significant differences as speed increases in body angle, wing beat frequency and speed of the traveling wave on the wing. In addition, we analyzed differences in wing curvature with swimming speed. At 1 BL s -1 , the pectoral wing is convex in shape during the downstroke along the medio-lateral fin midline, but at 2 BL s -1 the pectoral fin at this location cups into the flow, indicating active curvature control and fin stiffening. Wing kinematics of the little skate differed considerably from previous work on the freshwater stingray, which does not show active cupping of the whole fin on the downstroke. © 2017. Published by The Company of Biologists Ltd.

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

    Science.gov (United States)

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

    2015-01-01

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

  15. El fin del sueño tecnológico

    Directory of Open Access Journals (Sweden)

    Jaime de Cendra de Larragan

    2013-03-01

    Full Text Available Como ya afirmaba Aristóteles, Todos los hombres actúan movidos por un fin, este seria la meta intencional de todos nuestros actos, el norte que guía nuestras decisiones. Pero si tal fin es puesto en duda, si desaparece del horizonte humano, entonces se abre una brecha que es necesario colmar. El paso de un saber sapiencial a uno técnico que comienza con Bacon ira acompañado de una perdida de ese telos de la naturaleza. El vacío dejado por esa ausencia será colmado con el n propio de la tecnología que sigue la dinámica del progreso. De ese modo el n del hombre es sustituido por el n de la tecnología lo que le llevara a una situación de perdida progresiva de libertad. ¿Cómo responder a esa situación deshumanizante?

  16. Volumetric PIV of multiple free-swimming maneuvers generated by the KnifeBot: a biomimetic vessel propelled by an undulating fin

    Science.gov (United States)

    Liu, Hanlin; Troolin, Daniel; Hortensius, Ruben; Pothos, Stamatios; Curet, Oscar

    2017-11-01

    An undulating fin represents a remarkable propulsion model for underwater vehicles due to its high propulsive efficiency and considerable locomotor capabilities. In this work, we used a bio-inspired vessel, the KnifeBot to demonstrate the maneuverability of undulating fin propulsion, including forward-backward swimming, station keeping and vertical swimming. This self-contained robotic system uses an undulating ventral fin as the propulsor and features a slender 3D-printed hull with 16 motors, 2 batteries and electronic boards encapsulated inside. We tested the robot in a water-filled tank and used volumetric particle image velocimetry (V3V PIV) to investigate the three-dimensional flow features and vortex structures generated by the undulating ribbon fin in free-swimming maneuvers. Our results indicate that in the forward swimming, a series of vortex tubes are shed off the fin edge. A streamwise jet at an oblique angle to the fin is generated in association with the vortex tubes propelling the robot forward as well as pitching it up. For the hovering maneuver with inward counter-propagating waves. The streamlines develop vertically downward with the tip vortex shed from the fin edge. This downward jet provides substantial heave force for the robot to swim upward or perform station keeping. Our findings will be useful for understanding the mechanical basis of undulating fin propulsion and facilitate the development of bio-inspired vehicles using undulatory propellers. Office of Naval Research under Award Number N00014-16-1-2505.

  17. CFD Simulations of a Finned Projectile with Microflaps for Flow Control

    Directory of Open Access Journals (Sweden)

    Jubaraj Sahu

    2017-01-01

    Full Text Available This research describes a computational study undertaken to determine the effect of a flow control mechanism and its associated aerodynamics for a finned projectile. The flow control system consists of small microflaps located between the rear fins of the projectile. These small microflaps alter the flow field in the aft finned region of the projectile, create asymmetric pressure distributions, and thus produce aerodynamic control forces and moments. A number of different geometric parameters, microflap locations, and the number of microflaps were varied in an attempt to maximize the control authority generated by the flaps. Steady-state Navier-Stokes computations were performed to obtain the control aerodynamic forces and moments associated with the microflaps. These results were used to optimize the control authority at a supersonic speed, M=2.5. Computed results showed not only the microflaps to be effective at this speed, but also configurations with 6 and 8 microflaps were found to generate 25%–50% more control force than a baseline 4-flap configuration. These results led to a new optimized 8-flap configuration that was further investigated for a range of Mach numbers from M=0.8 to 5.0 and was found to be a viable configuration effective in providing control at all of these speeds.

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

    DEFF Research Database (Denmark)

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

    2009-01-01

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

  19. Fetal and early post-natal mineralization of the tympanic bulla in fin whales may reveal a Hitherto undiscovered evolutionary trait.

    Directory of Open Access Journals (Sweden)

    Bruno Cozzi

    Full Text Available The evolution of the cetacean skeleton followed a path that differentiated this group from other terrestrial mammals about 50 million years ago [1], and debate is still going on about the relationships between Cetacea and Artiodactyla [2], [3], [4]. Some skeletal traits of the basilosaurids (the more advanced forms of Archaeocetes, such as the expansion of the peribullary air sinuses, dental modification and vertebral size uniformity [5] are maintained and further emphasized also in contemporary odontocetes and mysticetes. Using Dual-Energy X-Ray Absorptiometry here we report that the deposition of bone mineral in fetal and newborn specimens of the fin whale Balaenoptera physalus is remarkably higher in the bulla tympanica than in the adjacent basal skull or in the rest of the skeleton. Ossification of the tympanic bulla in fetal Artiodactyla (bovine, hippopotamus is minimal, becomes sensible after birth and then progresses during growth, contrarily to the precocious mineralization that we observed in fin whales. Given the importance of the ear bones for the precise identification of phylogenetic relationship in therian evolution [6], this feature may indicate a specific evolutionary trait of fin whales and possibly other cetacean species or families. Early mineralization of the tympanic bulla allows immediate sound conduction in the aquatic medium and consequently holds potential importance for mother-calf relationship and postnatal survival.

  20. Thermal performance of a spirally coiled finned tube heat exchanger under wet-surface conditions

    International Nuclear Information System (INIS)

    Wongwises, Somchai; Naphon, Paisarn

    2006-01-01

    This paper is a continuation of the author's previous work on spiral coil heat exchangers. In the present study, the heat transfer characteristics and the performance of a spirally coiled finned tube heat exchanger under wet-surface conditions are theoretically and experimentally investigated. The test section is a spiral-coil heat exchanger which consists of a steel shell and a spirally coiled tube unit. The spiral-coil unit consists of six layers of concentric spirally coiled finned tubes. Each tube is fabricated by bending a 9.6 mm diameter straight copper tube into a spiral-coil of four turns. The innermost and outermost diameters of each spiral-coil are 145.0 and 350.4 mm, respectively. Aluminium crimped spiral fins with thickness of 0.6 mm and outer diameter of 28.4 mm are placed around the tube. The edge of fin at the inner diameter is corrugated. Air and water are used as working fluids in shell side and tube side, respectively. The experiments are done under dehumidifying conditions. A mathematical model based on the conservation of mass and energy is developed to simulate the flow and heat transfer characteristics of working fluids flowing through the heat exchanger. The results obtained from the present model show reasonable agreement with the experimental data

  1. Thermal performance analysis and optimum design parameters of heat exchanger having perforated pin fins

    International Nuclear Information System (INIS)

    Sahin, Bayram; Demir, Alparslan

    2008-01-01

    This paper reports the heat transfer enhancement and corresponding pressure drop over a flat surface equipped with circular cross section perforated pin fins in a rectangular channel. The channel had a cross section area of 100-250 mm 2 . The experiments covered the following ranges: Reynolds number 13500-42,000, clearance ratio (C/H) 0, 0.33 and 1 and interfin spacing ratio (S y /D) 1.208, 1.524, 1.944 and 3.417. Correlation equations were developed for the heat transfer, friction factor and enhancement efficiency. The experimental results showed that the use of circular cross section pin fins may lead to heat transfer enhancement. Enhancement efficiencies varied between 1.4 and 2.6 depending on clearance ratio and interfin spacing ratio. Using a Taguchi experimental design method, optimum design parameters and their levels were investigated. Nusselt number and friction factor were considered as performance parameters. An L 9 (3 3 ) orthogonal array was selected as an experimental plan. First of all, each goal was optimized separately. Then, all the goals were optimized together, considering the priority of the goals, and the optimum results were found to be Reynolds number of 42,000, fin height of 50 mm and streamwise distance between fins of 51 mm

  2. Some exact solutions of nonlinear fin problem for steady heat transfer in longitudinal fin with different profiles

    CSIR Research Space (South Africa)

    Mhlongo, MD

    2014-05-01

    Full Text Available and heat transfer coefficient.This work has been extended in [11] whereby the introduction of the Kirchhoff transformation linearized the one-dimensional fin problem when heat transfer is a differential consequence of thermal conductivity. Symmetry methods... 𝑥 ( 𝜉 ) , 𝜁 𝑥𝑥 = 𝐷 𝑥 (𝜁 𝑥 ) − 𝜃 󸀠󸀠 𝐷 𝑥 ( 𝜉 ) , (46) 10 Advances in Mathematical Physics Table 10: Lie bracket of the admitted symmetry algebra for𝑚 ̸= 𝑛, 𝑛 ̸= − 1 and various 𝑓(𝑥). 𝑓(𝑥) = 𝑥 𝑎 𝑎 = 0 𝑛 arbitrary 𝑓(𝑥) = 𝑥𝑎...

  3. Finned tube heat exchangers. (Latest citations from the EI Compendex*plus database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-04-01

    The bibliography contains citations concerning theoretical studies and applications of finned tubing in a variety of heat exchanger design configurations. The effects of turbulent and laminar flow are presented in terms of heat transfer for both external and internal finned surfaces. Energy conservation and waste heat recovery systems are featured and the use of refrigerants is also included. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  4. Moments of disaster response in the emergency department (ED).

    Science.gov (United States)

    Hammad, Karen S; Arbon, Paul; Gebbie, Kristine; Hutton, Alison

    2017-11-01

    We experience our lives as a series of memorable moments, some good and some bad. Undoubtedly, the experience of participating in disaster response, is likely to stand out as a memorable moment in a nurses' career. This presentation will describe five distinct moments of nursing in the emergency department (ED) during a disaster response. A Hermeneutic Phenomenological approach informed by van Manen underpins the research process. Thirteen nurses from different countries around the world participated in interviews about their experience of working in the ED during a disaster. Thematic analysis resulted in five moments of disaster response which are common to the collective participant experience. The 5 themes emerge as Notification (as a nurse finds out that the ED will be receiving casualties), Waiting (waiting for the patients to arrive to the ED), Patient Arrival (the arrival of the first patients to the ED), Caring for patients (caring for people affected by the disaster) and Reflection (the moment the disaster response comes to an end). This paper provides an in-depth insight into the experience of nursing in the ED during a disaster response which can help generate awareness and inform future disaster preparedness of emergency nurses. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  5. Predicting tularemia with clinical, laboratory and demographical findings in the ED.

    Science.gov (United States)

    Yapar, Derya; Erenler, Ali Kemal; Terzi, Özlem; Akdoğan, Özlem; Ece, Yasemin; Baykam, Nurcan

    2016-02-01

    We aimed to determine clinical, laboratory and demographical characteristics of tularemia on admission to Emergency Department (ED). Medical data of 317 patients admitted to ED and subsequently hospitalized with suspected tularemia between January 1, 2011, and May 31, 2015, were collected. Patients were divided into 2 groups according to microagglutination test results, as tularemia (+) and tularemia (-). Of the 317 patients involved, 49 were found to be tularemia (+) and 268 were tularemia (-). Mean age of the tularemia (+) patients was found to be higher than that of tularemia (-) patients. When compared to tularemia (-) patients, a significant portion of patients in tularemia (+) patients were elderly, living in rural areas and had contact with rodents. When clinical and laboratory findings of the 2 groups were compared, any statistical significance could not be determined. Tularemia is a disease of elderly people living in rural areas. Contact with rodents also increases risk of tularemia in suspected patients. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Numerical analysis of natural convection and radiation heat transfer from various shaped thin fin-arrays placed on a horizontal plate-a conjugate analysis

    International Nuclear Information System (INIS)

    Dogan, M.; Sivrioglu, Mecit; Yılmaz, Onder

    2014-01-01

    Highlights: • Optimum fin shape is determined for natural convection and radiation heat transfer. • Fin array with the optimum shape has a much greater average heat transfer coefficient. • The most important factors affecting the heat transfer coefficient are determined. - Abstract: Steady state natural convection and radiation heat transfer from various shaped thin fin-arrays on a horizontal base plate has been numerically investigated. A conjugate analysis has been carried out in which the conservation equations of mass, momentum and energy for the fluid in the two fin enclosure are solved together with the heat conduction equation in the fin and the base plate. Heat transfer by radiation is also considered in analysis. The heat transfer coefficient has been determined for each of the fin array considered in the present study at the same base and the same total area. The results of the analysis show that there are some important geometrical factors affecting the design of fin arrays. Taking into consideration these factors, an optimum fin shape that yields the highest average heat transfer coefficient has been determined

  7. Performance analysis and optimization of radiating fins with a step change in thickness and variable thermal conductivity by homotopy perturbation method

    Science.gov (United States)

    Arslanturk, Cihat

    2011-02-01

    Although tapered fins transfer more rate of heat per unit volume, they are not found in every practical application because of the difficulty in manufacturing and fabrications. Therefore, there is a scope to modify the geometry of a constant thickness fin in view of the less difficulty in manufacturing and fabrication as well as betterment of heat transfer rate per unit volume of the fin material. For the better utilization of fin material, it is proposed a modified geometry of new fin with a step change in thickness (SF) in the literature. In the present paper, the homotopy perturbation method has been used to evaluate the temperature distribution within the straight radiating fins with a step change in thickness and variable thermal conductivity. The temperature profile has an abrupt change in the temperature gradient where the step change in thickness occurs and thermal conductivity parameter describing the variation of thermal conductivity has an important role on the temperature profile and the heat transfer rate. The optimum geometry which maximizes the heat transfer rate for a given fin volume has been found. The derived condition of optimality gives an open choice to the designer.

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

    Data.gov (United States)

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

  9. Three-dimensional Finite Elements Method simulation of Total Ionizing Dose in 22 nm bulk nFinFETs

    Energy Technology Data Exchange (ETDEWEB)

    Chatzikyriakou, Eleni, E-mail: ec3g12@soton.ac.uk; Potter, Kenneth; Redman-White, William; De Groot, C.H.

    2017-02-15

    Highlights: • Simulation of Total Ionizing Dose using the Finite Elements Method. • Carrier generation, transport and trapping in the oxide. • Application in three-dimensional bulk FinFET model of 22 nm node. • Examination of trapped charge in the Shallow Trench Isolation. • Trapped charge dependency of parasitic transistor current. - Abstract: 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 SiO{sub 2} 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(SiO{sub 2}).

  10. The impact of FinTech start-ups on incumbent retail banks' share prices

    OpenAIRE

    Li, Yinqiao; Spigt, Renée; Swinkels, Laurens

    2017-01-01

    Background: This study aims to clarify the role of FinTech digital banking start-ups in the financial industry. We examine the impact of the funding of such start-ups on the stock returns of 47 incumbent US retail banks for 2010 to 2016. Methods: To capture the importance of FinTech start-ups, we use data on both the dollar-volume of funding and number of deals. We relate these to the stock returns with panel data regression methods. Results: Our results indicate a positive relationship exist...

  11. Post Irradiation Examination Results of the NT-02 Graphite Fins NUMI Target

    Energy Technology Data Exchange (ETDEWEB)

    Ammigan, K. [Fermilab; Hurh, P. [Fermilab; Sidorov, V. [Fermilab; Zwaska, R. [Fermilab; Asner, D. M. [PNL, Richland; Casella, Casella,A.M [PNL, Richland; Edwards, D. J. [PNL, Richland; Schemer-Kohrn, A. L. [PNL, Richland; Senor, D. J. [PNL, Richland

    2017-02-10

    The NT-02 neutrino target in the NuMI beamline at Fermilab is a 95 cm long target made up of segmented graphite fins. It is the longest running NuMI target, which operated with a 120 GeV proton beam with maximum power of 340 kW, and saw an integrated total proton on target of 6.1 1020. Over the last half of its life, gradual degradation of neutrino yield was observed until the target was replaced. The probable causes for the target performance degradation are attributed to radiation damage, possibly including cracking caused by reduction in thermal shock resistance, as well as potential localized oxidation in the heated region of the target. Understanding the long-termstructural response of target materials exposed to proton irradiation is critical as future proton accelerator sources are becoming increasingly more powerful. As a result, an autopsy of the target was carried out to facilitate post-irradiation examination of selected graphite fins. Advanced microstructural imaging and surface elemental analysis techniques were used to characterize the condition of the fins in an effort to identify degradation mechanisms, and the relevant findings are presented in this paper.

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

    Science.gov (United States)

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

    2013-02-01

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

  13. Reconsideration of data and correlations for plate finned-tube heat exchangers

    Science.gov (United States)

    Otović, Milena; Mihailović, Miloš; Genić, Srbislav; Jaćimović, Branislav; Milovančević, Uroš; Marković, Saša

    2018-04-01

    This paper deals with heat exchangers having plain finned tubes in staggered (triangular) pattern. The objective of this paper is to provide the heat transfer and friction factor correlation which can be used in engineering practice. For this purpose, the experimental data of several (most cited) authors who deal with this type of heat exchangers are used. The new correlations are established to predict the air-side heat transfer coefficient and friction factor as a function of the Reynolds number and geometric variables of the heat exchanger - tube diameter, tube pitch, fin spacing, tube rows, etc. In those correlations the characteristic dimension in Reynolds number is calculated by using the new parameter - volumetric porosity. Also, there are given the errors of those correlations.

  14. The dlx5a/dlx6a genes play essential roles in the early development of zebrafish median fin and pectoral structures.

    Directory of Open Access Journals (Sweden)

    Eglantine Heude

    Full Text Available The Dlx5 and Dlx6 genes encode homeodomain transcription factors essential for the proper development of limbs in mammalian species. However, the role of their teleost counterparts in fin development has received little attention. Here, we show that dlx5a is an early marker of apical ectodermal cells of the pectoral fin buds and of the median fin fold, but also of cleithrum precursor cells during pectoral girdle development. We propose that early median fin fold establishment results from the medial convergence of dlx5a-expressing cells at the lateral edges of the neural keel. Expression analysis also shows involvement of dlx5a during appendage skeletogenesis. Using morpholino-mediated knock down, we demonstrate that disrupted dlx5a/6a function results in pectoral fin agenesis associated with misexpression of bmp4, fgf8a, and1 and msx genes. In contrast, the median fin fold presents defects in mesenchymal cell migration and actinotrichia formation, whereas the initial specification seems to occur normally. Our results demonstrate that the dlx5a/6a genes are essential for the induction of pectoral fin outgrowth, but are not required during median fin fold specification. The dlx5a/6a knock down also causes a failure of cleithrum formation associated with a drastic loss of runx2b and col10a1 expression. The data indicate distinct requirements for dlx5a/6a during median and pectoral fin development suggesting that initiation of unpaired and paired fin formation are not directed through the same molecular mechanisms. Our results refocus arguments on the mechanistic basis of paired appendage genesis during vertebrate evolution.

  15. The dlx5a/dlx6a Genes Play Essential Roles in the Early Development of Zebrafish Median Fin and Pectoral Structures

    Science.gov (United States)

    Heude, Églantine; Shaikho, Sarah; Ekker, Marc

    2014-01-01

    The Dlx5 and Dlx6 genes encode homeodomain transcription factors essential for the proper development of limbs in mammalian species. However, the role of their teleost counterparts in fin development has received little attention. Here, we show that dlx5a is an early marker of apical ectodermal cells of the pectoral fin buds and of the median fin fold, but also of cleithrum precursor cells during pectoral girdle development. We propose that early median fin fold establishment results from the medial convergence of dlx5a-expressing cells at the lateral edges of the neural keel. Expression analysis also shows involvement of dlx5a during appendage skeletogenesis. Using morpholino-mediated knock down, we demonstrate that disrupted dlx5a/6a function results in pectoral fin agenesis associated with misexpression of bmp4, fgf8a, and1 and msx genes. In contrast, the median fin fold presents defects in mesenchymal cell migration and actinotrichia formation, whereas the initial specification seems to occur normally. Our results demonstrate that the dlx5a/6a genes are essential for the induction of pectoral fin outgrowth, but are not required during median fin fold specification. The dlx5a/6a knock down also causes a failure of cleithrum formation associated with a drastic loss of runx2b and col10a1 expression. The data indicate distinct requirements for dlx5a/6a during median and pectoral fin development suggesting that initiation of unpaired and paired fin formation are not directed through the same molecular mechanisms. Our results refocus arguments on the mechanistic basis of paired appendage genesis during vertebrate evolution. PMID:24858471

  16. El fin del petróleo

    OpenAIRE

    Fontaine, Guillaume

    2007-01-01

    En el momento en que los demócratas de los Estados Unidos han encabezado, al parecer, la cruzada mundial contra el cambio climático, quizá no es inútil leer (o releer) el ensayo del periodista Paul Roberts, publicado a finales del 2004 bajo el título llamativo de "El fin del petróleo". En efecto, cuando se reactivan las recetas del "charity business" (como eran los megaconciertos contra la hambruna y la sequía en Somalia, o para la liberación de Mandela) para salvar nuestro planeta, y m...

  17. Mixed convection heat transfer between a steam/non-condensable gas mixture and an inclined finned tube bundle

    Energy Technology Data Exchange (ETDEWEB)

    De Cachard, F.; Lompersky, S.; Monauni, G.R. [Paul Scherrer Institute, Villigen (Switzerland). Thermal Hydraulic Lab.

    1999-07-01

    An experimental and analytical program was performed at PSI (Paul Scherrer Institute) to study the performance of a finned-tube condenser in the presence of non-condensable gases at low gas mass fluxes. The model developed for this application includes mixed convection heat transfer between the vapour/non-condensable mixture and the finned tubes, heat conduction through the fins and tubes, and evaporative heat transfer inside the tubes. On the gas, heat transfer correlations are used, and the condensation rate is calculated using the heat/mass transfer analogy. A combination of various available correlations for forced convection in staggered finned tube bundles is used, together with a correction accounting for superimposed natural convection. For the condensate heat transfer resistance, the beatty and Katz model for gravity driven liquid films on the tubes is used. The fine efficiency is accounted for using classical iterative calculations. Evaporative heat transfer inside the tubes is predicted using the Chen correlation. The finned tube condenser model has been assessed against data obtained at the PSI LINX facility with two test condensers. For the 62 LINX experiments performed, the model predictions are very good, i.e., less then 10% standard deviation between experimental and predicted results.

  18. 2003 annual results of EdF group

    International Nuclear Information System (INIS)

    2004-03-01

    The Electricite de France (EdF) group Board of Directors, meeting on March 11, 2004, under the Chairmanship of Francois Roussely, reviewed the audited consolidated financial statements for the year ended 12/31/2003. This document presents the consolidated results of EdF group for 2003: consolidated financial statements, highlights of the year, focus on 2003 events, commercial results, EDF in Europe and worldwide, EDF France highlights, key figures. (J.S.)

  19. Stability Criterion for a Finned Spinning Projectile

    OpenAIRE

    S. D. Naik

    2000-01-01

    The state-of-the-art in gun projectile technology has been used for the aerodynamic stabilisation.This approach is acceptable for guided and controlled rockets but the free-flight rockets suffer fromunacceptable dispersion. Sabot projectiles with both spin and fms developed during the last decadeneed careful analysis. In this study, the second method of Liapunov has been used to develop stability criterion for a projectile to be designed with small fins and is made to spin in the flight. This...

  20. First integrals and analytical solutions of the nonlinear fin problem ...

    Indian Academy of Sciences (India)

    2016-07-06

    Jul 6, 2016 ... As stated in [3,4], in the engineering applications, fins are used to facilitate .... This method can be applied when the differential equa- tion does not have a ... method is extended to fractional differential equations. [16]. Now, we ...

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