WorldWideScience

Sample records for leg fin radiating

  1. Lightweight Radiator Fins for Space Nuclear Power, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase 1 project shall investigate concept radiator fins that incorporate novel carbon materials for improved performance of segmented high temperature...

  2. Convective–radiative radial fins with convective base heating and convective–radiative tip cooling: Homogeneous and functionally graded materials

    International Nuclear Information System (INIS)

    Aziz, A.; Torabi, Mohsen; Zhang, Kaili

    2013-01-01

    Highlights: • Convective–radiative radial fins with base convective heating were analyzed. • Homogeneous material and functionally graded material fins were investigated. • Fin efficiency and the effects of dimensionless parameters in fins were analyzed. - Abstract: This paper studies a radial fin of uniform thickness with convective heating at the base and convective–radiative cooling at the tip. The fin is assumed to experience uniform internal heat generation. The exposed surfaces of the fin lose heat by simultaneous convection and radiation to the surroundings. Two types of fin materials are investigated: homogeneous material and functionally graded material (FGM). For the homogeneous material, the thermal conductivity is assumed to be a linear function of temperature, while for the FGM fin the thermal conductivity is modeled as a linear function of the dimensionless radial coordinate. The analysis is conducted using the differential transformation method (DTM). The accuracy of DTM is verified by comparing the results for the simplified versions of the present model with an exact analytical solution derived here. Once the accuracy of DTM is authenticated, the method is used to generate results for the general problem formulated here. These results illustrate the effects of various dimensionless parameters on the thermal performance of homogeneous material fins and FGM fins

  3. 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.

  4. A Design Procedure for the Weight Optimization of Straight Finned Radiators

    National Research Council Canada - National Science Library

    Harris, Dale

    1966-01-01

    ... practical. In a recent study program of weight optimization of thermoelectric power generators, a technique was established which permits the rapid determination of the geometry of a minimum weight finned radiator system...

  5. Radiation processing for the control of Salmonella in frog legs

    International Nuclear Information System (INIS)

    Nerkar, D.P.; Kumta, U.S.; Sreenivasan, A.

    1976-01-01

    Large consignments of frogs legs are exported annually from India. Failure to satisfy some of the strict microbiological standards, especially in relating to Salmonellae contamination, has resulted in the rejection of large quantities of the product in recent years. This has emphasised the need for better and more effective methods than those currently in use for the elimination of Salmonellae. With a view to developing an irradiation process for the control of this public health problem, commercial samples of frog legs have been screened to assess the incidence of Salmonella. The various serotypes have been identified and their radiation sensitivities determined. Based on these data, a radiation treatment of frozen frog legs for the elimination of Salmonella has been developed. (author)

  6. 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

  7. Analysis of radiative heat transfer impact in cross-flow tube and fin heat exchangers

    Directory of Open Access Journals (Sweden)

    Hanuszkiewicz-Drapała Małgorzata

    2016-03-01

    Full Text Available A cross-flow, tube and fin heat exchanger of the water – air type is the subject of the analysis. The analysis had experimental and computational form and was aimed for evaluation of radiative heat transfer impact on the heat exchanger performance. The main element of the test facility was an enlarged recurrent segment of the heat exchanger under consideration. The main results of measurements are heat transfer rates, as well as temperature distributions on the surface of the first fin obtained by using the infrared camera. The experimental results have been next compared to computational ones coming from a numerical model of the test station. The model has been elaborated using computational fluid dynamics software. The computations have been accomplished for two cases: without radiative heat transfer and taking this phenomenon into account. Evaluation of the radiative heat transfer impact in considered system has been done by comparing all the received results.

  8. 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.

  9. Heat transfer study on convective–radiative semi-spherical fins with temperature-dependent properties and heat generation using efficient computational methods

    International Nuclear Information System (INIS)

    Atouei, S.A.; Hosseinzadeh, Kh.; Hatami, M.; Ghasemi, Seiyed E.; Sahebi, S.A.R.; Ganji, D.D.

    2015-01-01

    In this study, heat transfer and temperature distribution equations for semi-spherical convective–radiative porous fins are presented. Temperature-dependent heat generation, convection and radiation effects are considered and after deriving the governing equation, Least Square Method (LSM), Collocation Method (CM) and fourth order Runge-Kutta method (NUM) are applied for predicting the temperature distribution in the described fins. Results reveal that LSM has excellent agreement with numerical method, so can be suitable analytical method for solving the problem. Also, the effect of some physical parameters which are appeared in the mathematical formulation on fin surface temperature is investigated to show the effect of radiation and heat generation in a solid fin temperature. - Highlights: • Thermal analysis of a semi-spherical fin is investigated. • Collocation and Least Square Methods are applied on the problem. • Convection, radiation and heat generation is considered. • Physical results are compared to numerical outcomes.

  10. Is Leg Length Discrepancy Associated With the Side of Radiating Pain in Patients With a Lumbar Herniated Disc?

    NARCIS (Netherlands)

    ten Brinke, Albert P.T.; van der Aa, Hans E.; van der Palen, Jacobus Adrianus Maria; Oosterveld, Frits P.T.

    1999-01-01

    Study Design. The association between leg length discrepancy and the side of the radiating pain in lumbar disc herniation was investigated in a case series. Objectives. To investigate whether pain tends to radiate into the longer or shorter leg in patients with a lumbar herniated disc. Summary of

  11. 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.

  12. Analog performance of standard and uniaxial strained triple-gate SOI FinFETs under x-ray radiation

    Science.gov (United States)

    Bordallo, C. C. M.; Teixeira, F. F.; Silveira, M. A. G.; Martino, J. A.; Agopian, P. G. D.; Simoen, E.; Claeys, C.

    2014-12-01

    The influence of x-ray irradiation on the main digital and analog parameters of triple gate silicon-on-insulator FinFETs is investigated for unstrained and uniaxially strained devices. Comparing the p- and n-MuGFET response to radiation, x-rays can be more harmful for nMuGFETs than for the p-type counterparts due to the back-interface leakage current, which is generated by the positive charges trapped in the buried oxide. However, in pMuGFETs, the radiation tends to suppress the parasitic back-conduction, resulting in an improvement of the device performance.

  13. Protection by S-2-(3-aminopropylamino)ethylphosphorothioic acid against radiation-induced leg contractures in mice

    International Nuclear Information System (INIS)

    Hunter, N.; Milas, L.

    1983-01-01

    S-2-(3-Aminopropylamino)ethylphosphorothioic acid (WR-2721) was shown to provide marked protection against development of radiation-induced leg contractures in C3Hf/Kam mice whose legs were exposed to single doses of gamma-radiation. The radiation doses ranged from 3300 to 6200 rads delivered to the right hind thighs from two parallelly opposed 137Cs sources. WR-2721 was given i.p. 30 min before irradiation. The severity of radiation-induced leg contractures in untreated and WR-2721-treated mice was followed for 342 days after irradiation. The degree of leg contractures in both control and WR-2721-treated mice increased up to 100 days after radiation, when the change stabilized, remaining more or less at the same level to the end of the observation period. During this entire period, the severity of contractures was less in WR-2721-treated mice. The dose-modifying factor for the level of 5 mm reduction in leg extension was 1.5 at 182 days after irradiation. Since WR-2721 did not prevent the radiocurability of 8-mm fibrosarcomas growing in the same legs, these data imply that WR-2721 has a high potential for increasing therapeutic gain when combined with irradiation in the treatment of tumors of an appreciable size

  14. Radioprotection by WR-151327 against the late normal tissue damage in mouse hind legs from gamma ray radiation

    International Nuclear Information System (INIS)

    Matsushita, Satoru; Ando, Koichi; Koike, Sachiko

    1994-01-01

    To evaluate the protective effect of WR-151327 on late radiation-induced damaged to normal tissues in mice, the right hind legs of mice with or without WR-151327 administration (400 mg/kg) were irradiated with 137 Cs gamma rays. Leg contracture and skin shrinkage assays were performed at 380 days after irradiation. The mice were killed on day 400 postirradiation and histological sections of the legs were made. The thickness of the dermis, epidermis, and skin (dermis plus epidermis) was measured. The muscular area of the legs and the posterior knee angle between the femur and tibia were also measured. The left hind legs were similarly assessed as nonirradiated controls. Group means and standard deviations were calculated and dose-response curves were drawn for every endpoint. Then, the dose modifying factor (DMF) for each endpoint and the correlations among endpoints were determined. Latae damage assayed by leg contracture and skin shrinkage progressed with increasing radiation dose. However, it was reduced by drug treatment. The significant effect was indicated for skin shrinkage by a DMF of 1.8 at 35%. The DMF for leg contracture was 1.3 at 6 mm. In the irradiated legs, epidermal hyperplasia and dermal fibrosis in the skin, muscular atrophy, and extension disturbance of the knee joint were observed. These changes progressed with increasing radiation dose. Skin damage assayed by the present endpoints was also reduced by drug treatment by DMFs of 1.4 to 1.7. However, DMFs for damage to the muscle and knee were not determined because no isoeffect was observed. There were good correlations between leg contracture or skin shrinkage and the other endpoints in both untreated and drug-treated mice. WR-151327 has the potential to protect against radiation-induced late normal tissue damage. 17 refs., 6 figs., 2 tabs

  15. Periumbilical Pain with Radiation to Both Legs Following Tarantula Bite; a Case Report

    Directory of Open Access Journals (Sweden)

    Mahboob Pouraghaei

    2015-07-01

    Full Text Available Tarantulas have recently become as pets in most parts of the world that increased the probability of encountering emergency physicians with patients hurt with these spiders. Their attacks usually do not cause general manifestation, however there are some case reports in this regard. Here, a 40-year-old man was reported who was referred to the emergency department with severe periumbilical pain that radiated to both legs and diagnosed as a victim of tarantula bite. Such symptoms usually are belonging to other spiders like Black Widow spider, but it seems that tarantula can mimic them in some cases, too.

  16. Regulation of use of radiation for quarantine purposes; Regulamentacao do uso da radiacao para fins quarentenarios

    Energy Technology Data Exchange (ETDEWEB)

    Itepan, Natanael Marcio, E-mail: natanael.itepan@unianhanguera.edu.b [Faculdade Anhanguera, Piracicaba, SP (Brazil); Costa, Neivaldo; Furlan, Gilberto Ribeiro; Walder, Julio Marcos Melges, E-mail: neivaldo@cena.usp.b, E-mail: gilfurlan@cena.usp.b, E-mail: jmwalder@cena.usp.b [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil)

    2011-07-01

    The main aspects of Instruction No. 9 are: a) the nuclear plant that use ionizing radiation as a phyto sanitary treatment for quarantine purposes, must be accredited by the agency of the Agriculture, Livestock and Supply Ministry (MAPA) and the licensing by the Nuclear Energy National Commission (CNEN) and other regulatory bodies, b) control of the applied dose will follow a standard operating procedure should be performed by independent organization, authorized by the Brazilian ONPF (Phyto sanitary Protection National Organization), c) the unit of radiation treatment should ensure traceability and must maintain records of phyto sanitary treatments, d) there should be bilateral work plan between the ONPF of Brazil and other countries for the established radiation treatment protocol. The ONPF of Brazil is the Sanitary Vegetarian Department. Ionizing radiation (cold pasteurization) is shown in an alternative technology to phyto sanitary control for quarantine purposes. (author)

  17. Closed form solution for a conductive-convective-radiative annular fin with multiple nonlinearities and its inverse analysis

    Science.gov (United States)

    Ranjan, Rajiv; Mallick, Ashis; Prasad, Dilip K.

    2017-03-01

    The performance characteristics and temperature field of conducting-convecting-radiating annular fin are investigated. The nonlinear variation of thermal conductivity, power law dependency of heat transfer coefficient, linear variation of surface emissivity, and heat generation with the temperature are considered in the analysis. A semi-analytical approach, homotopy perturbation method is employed to solve the nonlinear differential equation of heat transfer. The analysis is presented in non-dimensional form, and the effect of various non-dimensional thermal parameters such as conduction-convection parameter, conduction-radiation parameter, linear and nonlinear variable thermal conductivity parameter, emissivity parameter, heat generation number and variable heat generation parameter are studied. For the correctness of the present analytical solution, the results are compared with the results available in the literature. In addition to forward problem, an inverse approach namely differential evolution method is employed for estimating the unknown thermal parameters for a given temperature field. The temperature fields are reconstructed using the inverse parameters and found to be in good agreement with the forward solution.

  18. Venogram - leg

    Science.gov (United States)

    Phlebogram - leg; Venography - leg; Angiogram - leg ... into a vein in the foot of the leg being looked at. An intravenous (IV) line is ... vein. A tourniquet may be placed on your leg so the dye flows into the deeper veins. ...

  19. Acupuncture for radiation or combined treatment induced edema in arms and legs of breast and cervical cancer patients

    International Nuclear Information System (INIS)

    Bardychev, M.S.; Guseva, L.I.; Zubova, N.D.

    1988-01-01

    Acupuncture was carried out in 141 sufferers from delayed radiation injuries to skin and soft tissues. 122 patients (86%) revealed clinical manifestations of edema of varying gravity in arms and legs, while 19 (14%) suffered radiation-induced neufritis or plexitis unaccompanied by edema. Radionuclide and rheographic studies as well as evaluation of hemostatic function showed acupuncture to be an effective treatment for edema and pain. it also improved lymph flow, rheovasographic indexes and normalized hemostasis. The best results were obtained in cases of stage 1-2 edema

  20. Tank Made Of Connected Cooling Fins

    Science.gov (United States)

    Schultz, Donald F.; O'Donnell, John J.

    1994-01-01

    New method of fabricating fin-cooled tank requires half as many arc-welding passes and features more efficient transfer of heat. Fins integral parts of tank structure. Requires only one welding pass per fin, and pass done on unobstructed inside of tank. With inside welding, fins longer and more closely spaced. Method proposed to build tank with 256 fins. Holds water in which radioisotope heat source immersed before use. Water absorbs bremsstrahlung radiation from isotope, and fins dissipate heat generated by absorption.

  1. Order of 3 May 1988 on treatment of frozen frogs' legs by ionizing radiation

    International Nuclear Information System (INIS)

    1988-01-01

    This order fixes the conditions for the sale of frogs' legs whose microbial decontamination was obtained through exposure to cobalt 60 or cesium 137 gamma-rays or accelerated electron beams with an energy below or equal to 10 Mev [fr

  2. Radiation shielding techniques and applications. 4. Two-Phase Monte Carlo Approach to Photon Streaming Through Three-Legged Penetrations

    International Nuclear Information System (INIS)

    White, Travis; Hack, Joe; Nathan, Steve; Barnett, Marvin

    2001-01-01

    Westinghouse Safety Management Solutions (Westinghouse SMS) has been tasked with providing radiological engineering design support for the new Commercial Light Water Reactor Tritium Extraction Facility (CLWR-TEF) being constructed at the Savannah River Site. The Remote Handling Building (RHB) of the CLWR-TEF will act as the receiving facility for irradiated targets used in the production of tritium for the U.S. Department of Energy (DOE). Because of the high dose rates, approaching 50 000 rads/h (500 Gy/h) from the irradiated target bundles, significant attention has been made to shielding structures within the facility. One aspect of the design that has undergone intense review is the issue of the penetrations through the shield walls of the RHB, which includes heating, ventilation, and air-conditioning ductwork; cylindrical piping penetrations; floor drains; and conduit penetrations. The 'DOE Design Considerations Handbook' suggests that 'straight-line penetration of shield walls should be avoided to prevent radiation streaming', which is a prudent suggestion in this case considering the strength of the source. Therefore, a three-legged penetration approach was adopted for each type of penetration. To incorporate the three-legged penetration approach into the design, certain parameters had to be determined and confirmed as adequate. The main parameter to be determined was a minimum required offset length of the middle leg of the penetration. Additional parameters to be determined were supplemental photon shielding to be added to the interior of the wall to compensate for the void in the concrete created by the penetration, and the minimum necessary overlap dimensions of the supplemental shielding. Further, in cases where the minimum middle-leg offset was not practical, additional shielding requirements were determined for supplemental shielding added to the entrance or exit of the penetration to attenuate radiation scattering down the penetration. Analytical

  3. Viability of Vibrio cholerae 01 on frog legs under frozen and refrigerated conditions and low dose radiation treatment

    International Nuclear Information System (INIS)

    Sang, F.C.; Hugh-Jones, M.E.; Hagstad, H.V.

    1987-01-01

    Frog legs were contaminated with Vibrio cholerae 01, Inaba serotype, EITor biotype. The organism remained viable for more than 28 and 2 d when stored at -20°C and 4°C, respectively. Exposure to a multicuries 60 Cobalt source of 50 and 100 kilorads eliminated V. cholerae from both the frozen and fresh frog legs

  4. Spiral finned crucible pot

    Science.gov (United States)

    Soemowidagdo, Arianto Leman; Tiwan, Widarto, Ardian, Aan

    2018-02-01

    Innovation on a crucible furnace to increase its efficiency in aluminum melting has been done. The innovation was a spiral finned crucible pot. The inclination of the spiral finned was vary of 5, 10, 15, and 20 degrees. The spiral finned effects was determined from the performance test result. A crucible pot without fin was also tested as a control. The crucible pot was examined at the same process condition. The crucible pot with the inclined fin of 10 degrees gives an optimum performance. It gives effective heating rate so that more efficient in LPG consumption. Therefore it saves energy in the aluminum melting process.

  5. Influence of misonidazole, anaesthesia, clamping of the leg and stress of the animal during treatment on the radiation-induced skin reaction of mouse feet

    International Nuclear Information System (INIS)

    Wondergem, J.; Haveman, J.; Schueren, E. van der

    1982-01-01

    The influence of anaesthesia and misonidazole on the 'acute' (average of the scores between day 10 and 30) and 'late' (average of the scores between day 100 and 120) skin reaction of the feet of mice was investigated under two different conditions. Firstly, the legs were kept untaped in the radiation field; secondly, the legs were fixed with surgical tape on the backscatter block. Irradiation was carried out by X-radiation at a dose of 35 Gy. Results showed that stress in unanaesthetized animals has a large influence on the radiation response of mouse skin. Adequate treatment conditions, tranquillizers or anaesthesia can compensate for this factor. Taping of the animals' legs, resulting in clamping, interferes with the assessment of these modalities. No influence of misonidazole on the skin reaction could be demonstrated in conditions where no artificial hypoxia was induced. The importance of taking experimental conditions into account is pointed out for the correct assessment of the effect of radiosensitizers and possibly other anticancer drugs. (U.K.)

  6. Non-steady-state heat transfer of finned surface

    International Nuclear Information System (INIS)

    Okamoto, Y.; Kameoka, T.

    1974-01-01

    For many purposes, the finned surface is being used to increase heat transfer. Heat exchangers and fuel elements of gas cooled nuclear reactors require the use of the finned surface for high flux heat transfer. The problem is analytically treated by deriving a non-steady-state equation of radiative and convective heat transfer of annular and radial fins in case of sudden change of the fin-root temperature or heat flux. The numerical solution of temperature distribution along the fin is obtained for several typical transient cases. (U.S.)

  7. Leg Swelling

    Science.gov (United States)

    ... ed. New York, N.Y.: The McGraw Hill Companies; 2016. http://www.accessmedicine.com. Accessed Dec. 31, ... http://www.mayoclinic.org/symptoms/leg-swelling/basics/definition/SYM-20050910 . Mayo Clinic Footer Legal Conditions and ...

  8. Broken Leg

    Science.gov (United States)

    ... the leg, which can result in a fracture. Stress fractures outside of sport situations are more common in people who have: ... shoes. Choose the appropriate shoe for your favorite sports or activities. And ... can prevent stress fractures. Rotate running with swimming or biking. If ...

  9. 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

  10. Night Leg Cramps

    Science.gov (United States)

    Symptoms Night leg cramps By Mayo Clinic Staff Night leg cramps, also called nocturnal leg cramps, are painful, involuntary contractions or spasms of muscles in your legs, usually occurring when you're in bed. Night ...

  11. Fin Distance Effect at Tube-Fin Heat Exchanger

    Directory of Open Access Journals (Sweden)

    Frana K.

    2013-04-01

    Full Text Available Article deals with numerical simulation of the Tube-Fin heat exchanger. Several distances between fins are examined with intence of increasing the cooling output of the heat exchanger. Geometrical model consists of set of 2 fins with input and output area. Calculations covers the area of the gap from 2.25 mm to 4 mm with new fin geometry. For the numerical silumation was used software Ansys Fluent.

  12. Pathological characteristics of extremely severe acute radiation injury in a patient's legs and hands after a very uneven accidental exposure to an extremely high dose of 192Ir

    International Nuclear Information System (INIS)

    Li Qing; Li Guomin; Liu Shujun; Yang Yijing; Li Fumeng; Yang Junhua

    1997-01-01

    The pathological characteristics of an extremely high dose radiation in the legs and hands of a patient is reported. the patient was exposed to 192 Ir γ-rays for 9 hours and 20 minutes, the activity of which was 2.76 TBq. The amputations of the right thigh and left forearm had to be performed 8 days after the irradiation and the debridements and skin graftings were performed on the right hand and the inner side of left knee 55 days after the radiation. Microscopically, massive necrosis of cells of the epidermis, cutaneous appendages, hypodermics and skeletal muscles, and hemorrhage in the dermis, hypodermics and skeletal muscles were seen in the local irradiated parts of the right shank. But the arrector pili muscles in the dermis of the right shank remained. On the fingers and the palm of the left hand, vacuolar degeneration and massive necrosis of the cells of epidermis were present with extensive neutrophil infiltration. Cysts of large or small size were formed from the necrotic cells, separating epidermis from dermis. There were degeneration and necrosis of glandular epithelium cells of sweat glands. Hemorrhage was present in dermis and hypodermics. All the hematopoietic tissues in the bone marrow in the upper ends of the tibia and fibula and in the lower ends of the femur, the radius and the ulna disappeared. Acute radiation ulcers were present on the skin of the left knee and on the skin of the thumb, index finger and middle finger of the right hand. The extremely severe acute radiation injury caused by extremely high dose of 192 Ir led to the necrosis of the extensive soft tissues deep to skeletal muscles and the disappearance of the hematopoietic tissues in the bone marrow

  13. 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)

  14. [Toxicity of puffer fish fins].

    Science.gov (United States)

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

    2007-10-01

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

  15. 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.

  16. Leg Injuries and Disorders

    Science.gov (United States)

    Your legs are made up of bones, blood vessels, muscles, and other connective tissue. They are important for motion ... falling, or having an accident can damage your legs. Common leg injuries include sprains and strains, joint ...

  17. Peripheral artery disease - legs

    Science.gov (United States)

    Peripheral vascular disease; PVD; PAD; Arteriosclerosis obliterans; Blockage of leg arteries; Claudication; Intermittent claudication; Vaso-occlusive disease of the legs; Arterial insufficiency of ...

  18. 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...

  19. Thermal diode cooling fin concept

    International Nuclear Information System (INIS)

    Lyall, H.G.; Watts, J.

    1983-01-01

    The heat input through the finned portions of the walls of a water-filled fuel transport flask during an accidental, hydrocarbon fire can be halved by the replacement of narrow, solid fins by wider, hollow fins of similar pitch. In a flask with lid and base heat-shields this has the effect of reducing mean water temperature rise by about one third. These savings are achieved at the relatively small expense of slightly increased (by about 1 degC/kW of decay heat load) pre-fire normal operating water temperatures. 7 references, 3 figures, 5 tables

  20. Brain radiation - discharge

    Science.gov (United States)

    Radiation - brain - discharge; Cancer-brain radiation; Lymphoma - brain radiation; Leukemia - brain radiation ... Decadron) while you are getting radiation to the brain. It may make you hungrier, cause leg swelling ...

  1. 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.

  2. Leg lengthening - slideshow

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/presentations/100127.htm Leg lengthening - series—Indications To use the sharing features ... with lengthening procedures are the bones of the leg, the tibia and the femur. Surgical treatment may ...

  3. Arterial bypass leg - slideshow

    Science.gov (United States)

    ... medlineplus.gov/ency/presentations/100155.htm Arterial bypass leg - series—Normal anatomy To use the sharing features ... Overview The arteries which supply blood to the leg originate from the aorta and iliac vessels. Review ...

  4. Leg lengthening and shortening

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/002965.htm Leg lengthening and shortening To use the sharing features on this page, please enable JavaScript. Leg lengthening and shortening are types of surgery to ...

  5. Gamma radiation use in Calibration Laboratory of Instituto de Pesquisas em Engenharia Nuclear - IPEN/CNEN-Br for radiation protection calibration purposes; Irradiacao gama no Laboratorio de Calibracao do IPEN para fins de calibracao em radioprotecao

    Energy Technology Data Exchange (ETDEWEB)

    Manzoli, Jose Eduardo [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Dept. de Metrologia das Radiacoes. Lab. de Calibracao de Instrumentos Detectores de Radiacao; Universidade Bandeirante de Sao Paulo, UNIBAN, SP (Brazil). Dept. de Engenharia; Potiens, Maria da Penha Albuquerque [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Dept. de Metrologia das Radiacoes. Lab. de Calibracao de Instrumentos Detectores de Radiacao]. E-mail: jmanzoli@net.ipen.br

    2001-07-01

    The Calibration Laboratory of IPEN, LCI, executes annually almost two thousand tests with gamma radiation in instruments used mainly for Radiation Protection purposes. These tests are performed at special rooms into the irradiation bunker. In order to achieve high quality services, the radiation fields has to be precisely and exactly determined. In this work it is presented many features and procedures applied at gamma ray irradiation rooms of LCI for its accreditation and which made it the most required calibration laboratory for survey meters in Brazil. (author)

  6. 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.

  7. Thermal Characterizations of Exponential Fin Systems

    Directory of Open Access Journals (Sweden)

    A.-R. A. Khaled

    2010-01-01

    Full Text Available Exponential fins are mathematically analyzed in this paper. Two types are considered: (i straight exponential fins and (ii pin exponential fins. The possibility of having increasing or decreasing cross-sectional areas is considered. Different thermal performance indicators are derived. The maximum ratio between the thermal efficiency of the exponential straight fin to that of the rectangular fin is found to be 1.58 at an effective thermal length of 2.0. This ratio is even larger when exponential fins are compared with triangular and parabolic straight fins. Moreover, the maximum ratio between the thermal efficiency of the exponential pin fin to that of the rectangular pin fin is found to be 1.17 at an effective thermal length of 1.5. However, exponential pin fins thermal efficiencies are found to be lower than those of triangular and parabolic pin fins. Moreover, exponential joint-fins may transfer more heat than rectangular joint-fins especially when differences between their senders and receivers portions dimensionless indices are very large. Finally, it is found that increasing the joint-fin exponential index may cause straight exponential joint-fins to transfer more heat than rectangular joint-fins.

  8. Foot, leg, and ankle swelling

    Science.gov (United States)

    Swelling of the ankles - feet - legs; Ankle swelling; Foot swelling; Leg swelling; Edema - peripheral; Peripheral edema ... Foot, leg, and ankle swelling is common when the person also: Is overweight Has a blood clot in the leg Is older Has ...

  9. Back Pain with Leg Pain.

    Science.gov (United States)

    Vulfsons, Simon; Bar, Negev; Eisenberg, Elon

    2017-07-01

    The clinical diagnostic dilemma of low back pain that is associated with lower limb pain is very common. In relation to back pain that radiates to the leg, the International Association for the Study of Pain (IASP) states: "Pain in the lower limb should be described specifically as either referred pain or radicular pain. In cases of doubt no implication should be made and the pain should be described as pain in the lower limb." Bogduks' editorial in the journal PAIN (2009) helps us to differentiate and define the terms somatic referred pain, radicular pain, and radiculopathy. In addition, there are other pathologies distal to the nerve root that could be relevant to patients with back pain and leg pain such as plexus and peripheral nerve involvement. Hence, the diagnosis of back pain with leg pain can still be challenging. In this article, we present a patient with back and leg pain. The patient appears to have a radicular pain syndrome, but has no neurological impairment and shows signs of myofascial involvement. Is there a single diagnosis or indeed two overlapping syndromes? The scope of our article encompasses the common diagnostic possibilities for this type of patient. A discussion of treatment is beyond the scope of this article and depends on the final diagnosis/diagnoses made.

  10. 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...

  11. 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

  12. 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.

  13. 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.

  14. Venous leg ulcers.

    Science.gov (United States)

    Nelson, E Andrea; Adderley, Una

    2016-01-15

    Leg ulcers usually occur secondary to venous reflux or obstruction, but 20% of people with leg ulcers have arterial disease, with or without venous disorders. Between 1.5 and 3.0 in 1000 people have active leg ulcers. Prevalence increases with age to about 20 in 1000 people aged over 80 years. We conducted a systematic overview, aiming to answer the following clinical questions: What are the effects of treatments for venous leg ulcers? What are the effects of organisational interventions for venous leg ulcers? What are the effects of advice about self-help interventions in people receiving usual care for venous leg ulcers? What are the effects of interventions to prevent recurrence of venous leg ulcers? We searched: Medline, Embase, The Cochrane Library, and other important databases up to March 2014 (Clinical Evidence overviews are updated periodically; please check our website for the most up-to-date version of this overview). At this update, searching of electronic databases retrieved 116 studies. After deduplication and removal of conference abstracts, 63 records were screened for inclusion in the overview. Appraisal of titles and abstracts led to the exclusion of 43 studies and the further review of 20 full publications. Of the 20 full articles evaluated, four systematic reviews were updated and four RCTs were added at this update. We performed a GRADE evaluation for 23 PICO combinations. In this systematic overview, we categorised the efficacy for 13 interventions based on information about the effectiveness and safety of advice to elevate leg, advice to keep leg active, compression stockings for prevention of recurrence, compression bandages and stockings to treat venous leg ulcers, laser treatment (low level), leg ulcer clinics, pentoxifylline, skin grafting, superficial vein surgery for prevention of recurrence, superficial vein surgery to treat venous leg ulcers, therapeutic ultrasound, and topical negative pressure.

  15. ''Del'fin'' high-power laser thermonuclear machine

    International Nuclear Information System (INIS)

    Basov, N.G.; Krokhin, O.N.; Mikhailov, Yu.A.; Sklizkov, G.V.; Fedotov, S.I.

    The high-power 12-channel ''Del'fin'' laser device, designed for high-temperature heating of thermonuclear targets in a spherical irradiation geometry, is described. The device includes a neodymium laser with a maximum radiative energy of approximately 10 kJ, a light pulse lasting 10 -10 -- 10 -9 sec with an irradiation divergence of approximately 5.10 -4 rad, a vacuum chamber in which the laser radiation interacts with a plasma, and a set of devices for laser parameter and plasma diagnostics. The optical design and structural characteristics of the laser system are discussed. Designs for focusing the radiation on a target are analyzed, and the focusing system of the ''Del'fin'' device, permitting a high degree of symmetry of the spherical irradiation of the target with a maximum flux density of approximately 10 15 W/cm 2 on its surface, is described. Also discussed is the problem of realizing the maximum possibilities of heating of spherical thermonuclear targets with the radiation of high-power laser systems. The practically attainable laser radiation parameters are also considered. In the case of a laser system with a series-parallel arrangement of the amplification stages, relationships are obtained which make it possible to analyze the effect of the target and laser parameters on the magnitude of the maximum possible laser pulse energy in a spherical heating geometry. The results obtained were used in the design of the ''Del'fin'' high-power laser device

  16. Dynamically Stable Legged Locomotion.

    Science.gov (United States)

    1983-01-27

    balanced itself in 31) using a tabular ctontrol sclwnme. With only thUiee actuated degrees it used a shuffling gait to balance that reminds one of Charlie ... Chaplin . * The present study explores the control of a physical one-legged hopping machine. The objective of using a machine with only one leg was to

  17. Lyden-af-Leg

    DEFF Research Database (Denmark)

    Toft, Herdis

    Præsentation af seniorforsker-projekt Lyden-af-Leg i et traderingsperspektiv og med indledende fokus på YouTube som traderings-platform.......Præsentation af seniorforsker-projekt Lyden-af-Leg i et traderingsperspektiv og med indledende fokus på YouTube som traderings-platform....

  18. Analysis of Fin Tip Temperature and Fin Efficiency for Different Fingeometries and Materials Using Abaqus

    International Nuclear Information System (INIS)

    Imran, S.; Noor, F.; Ali, H.; Hussain, A.; Ali, Z.; Shad, R.

    2015-01-01

    Fins are widely used in various engineering applications to enhance the rate of heat transfer. The effect of fin geometry and its material on the fin efficiency and the amount of heat transferred are investigated in this study. Rectangular and triangular fin geometries have been considered and two fin materials, aluminium and carbon steel, have been selected. It is found numerically that the fin tip temperature and the fin efficiency are decreased with the increase of the convective heat transfer coefficient. ABAQUS has been used to conduct this numerical study. (author)

  19. 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.

  20. Effects of fin fold mesenchyme ablation on fin development in zebrafish.

    Science.gov (United States)

    Lalonde, Robert L; Akimenko, Marie-Andrée

    2018-01-01

    The evolution of the tetrapod limb involved an expansion and elaboration of the endoskeletal elements, while the fish fin rays were lost. Loss of fin-specific genes, and regulatory changes in key appendicular patterning genes have been identified as mechanisms of limb evolution, however their contributions to cellular organization and tissue differences between fins and limbs remains poorly understood. During early larval fin development, hoxa13a/hoxd13a-expressing fin fold mesenchyme migrate through the median and pectoral fin along actinotrichia fibrils, non-calcified skeletal elements crucial for supporting the fin fold. Fin fold mesenchyme migration defects have previously been proposed as a mechanism of fin dermal bone loss during tetrapod evolution as it has been shown they contribute directly to the fin ray osteoblast population. Using the nitroreductase/metronidazole system, we genetically ablated a subset of hoxa13a/hoxd13a-expressing fin fold mesenchyme to assess its contributions to fin development. Following the ablation of fin fold mesenchyme in larvae, the actinotrichia are unable to remain rigid and the median and pectoral fin folds collapse, resulting in a reduced fin fold size. The remaining cells following ablation are unable to migrate and show decreased actinodin1 mesenchymal reporter activity. Actinodin proteins are crucial structural component of the actinotrichia. Additionally, we show a decrease in hoxa13a, hoxd13a, fgf10a and altered shha, and ptch2 expression during larval fin development. A continuous treatment of metronidazole leads to fin ray defects at 30dpf. Fewer rays are present compared to stage-matched control larvae, and these rays are shorter and less defined. These results suggest the targeted hoxa13a/hoxd13a-expressing mesenchyme contribute to their own successful migration through their contributions to actinotrichia. Furthermore, due to their fate as fin ray osteoblasts, we propose their initial ablation, and subsequent

  1. RESTLESS LEGS SYNDROME

    Directory of Open Access Journals (Sweden)

    Dmitriy Valer'evich Artem'ev

    2009-01-01

    Full Text Available The paper describes the epidemiology, etiology, pathogenesis, clinical picture, diagnosis, differential diagnosis, and treatment of restless legs syndrome. Recommendations are given how to choose therapeutic modalities and drugs in relation to different factors.

  2. Restless legs syndrome.

    Science.gov (United States)

    Venkateshiah, Saiprakash B; Ioachimescu, Octavian C

    2015-07-01

    Restless legs syndrome is a common sensorimotor disorder characterized by an urge to move, and associated with uncomfortable sensations in the legs (limbs). Restless legs syndrome can lead to sleep-onset or sleep-maintenance insomnia, and occasionally excessive daytime sleepiness, all leading to significant morbidity. Brain iron deficiency and dopaminergic neurotransmission abnormalities play a central role in the pathogenesis of this disorder, along with other nondopaminergic systems, although the exact mechanisms are still. Intensive care unit patients are especially vulnerable to have unmasking or exacerbation of restless legs syndrome because of sleep deprivation, circadian rhythm disturbance, immobilization, iron deficiency, and use of multiple medications that can antagonize dopamine. Published by Elsevier Inc.

  3. 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.

  4. 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.

  5. Mathematical Extrapolating of Highly Efficient Fin Systems

    Directory of Open Access Journals (Sweden)

    A.-R. A. Khaled

    2011-01-01

    Full Text Available Different high-performance fins are mathematically analyzed in this work. Initially, three types are considered: (i exponential, (ii parabolic, and (iii triangular fins. Analytical solutions are obtained. Accordingly, the effective thermal efficiency and the effective volumetric heat dissipation rate are calculated. The analytical results were validated against numerical solutions. It is found that the triangular fin has the maximum effective thermal length. In addition, the exponential pin fin is found to have the largest effective thermal efficiency. However, the effective efficiency for the straight one is the maximum when its effective thermal length based on profile area is greater than 1.4. Furthermore, the exponential straight fin is found to have effective volumetric heat dissipation that can be 440% and 580% above the parabolic and triangular straight fins, respectively. In contrast, the exponential pin fin is found to possess effective volumetric heat dissipation that can be 120% and 132% above the parabolic and triangular pin fins, respectively. Finally, new high performance fins are mathematically generated that can have effective volumetric heat dissipation of 24% and 12% above those of exponential pin and straight fins, respectively.

  6. Hybrid radiator cooling system

    Science.gov (United States)

    France, David M.; Smith, David S.; Yu, Wenhua; Routbort, Jules L.

    2016-03-15

    A method and hybrid radiator-cooling apparatus for implementing enhanced radiator-cooling are provided. The hybrid radiator-cooling apparatus includes an air-side finned surface for air cooling; an elongated vertically extending surface extending outwardly from the air-side finned surface on a downstream air-side of the hybrid radiator; and a water supply for selectively providing evaporative cooling with water flow by gravity on the elongated vertically extending surface.

  7. 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.

  8. Venous leg ulcers.

    Science.gov (United States)

    Nelson, E Andrea

    2011-12-21

    Leg ulcers usually occur secondary to venous reflux or obstruction, but 20% of people with leg ulcers have arterial disease, with or without venous disorders. Between 1.5 and 3.0/1000 people have active leg ulcers. Prevalence increases with age to about 20/1000 in people aged over 80 years. We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of standard treatments, adjuvant treatments, and organisational interventions for venous leg ulcers? What are the effects of advice about self-help interventions in people receiving usual care for venous leg ulcers? What are the effects of interventions to prevent recurrence of venous leg ulcers? We searched: Medline, Embase, The Cochrane Library, and other important databases up to June 2011 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). We found 101 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. In this systematic review we present information relating to the effectiveness and safety of the following interventions: compression bandages and stockings, cultured allogenic (single or bilayer) skin replacement, debriding agents, dressings (cellulose, collagen, film, foam, hyaluronic acid-derived, semi-occlusive alginate), hydrocolloid (occlusive) dressings in the presence of compression, intermittent pneumatic compression, intravenous prostaglandin E1, larval therapy, laser treatment (low-level), leg ulcer clinics, multilayer elastic system, multilayer elastomeric (or non-elastomeric) high-compression regimens or bandages, oral treatments (aspirin, flavonoids, pentoxifylline, rutosides, stanozolol, sulodexide

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

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Soo; Kim, Min Soo; Lee, Kwan Soo [Hanyang Univ., Seoul (Korea, Republic of); Kim, Ook Joong [Korea Institute of Machinery and Materials, Daejeon (Korea, Republic of)

    2007-07-01

    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.

  10. 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 contaminant for people. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Numerical and experimental investigation of multi-mode heat transfer in a square cavity with and without triangular fins

    Science.gov (United States)

    Pandey, Sudhanshu; Gedupudi, Sateesh; Venkateshan, S. P.

    2018-03-01

    Numerical and experimental studies on laminar natural convection and radiation in a differentially heated cavity with/without triangular fins are presented. The square cavity is filled with air (Pr = 0.71). The top and bottom walls are adiabatic, while the active (hot) and cold walls are isothermal. Triangular conductive fins made of highly conductive material are placed on the heated and cooled vertical surfaces of a square cavity. The effects of pertinent parameters on fluid flow and heat transfer characteristics are studied. The governing differential equations, assuming laminar flow, are solved using the commercial software FLUENT. Experiments have been carried out for three different configurations viz square cavity without fins, square cavity with two fins on vertical walls and square cavity with continuous fins on vertical walls. Rayleigh number varies from 1.18 × 105 to 2.15 × 105 for the first experiment (square cavity without fins). The other two experiments with fins have been conducted for six different heat inputs. The numerical results have been validated against the experimental results obtained. It is concluded that the triangular fins on isothermal walls enhance the heat transfer in the cavity. Natural convection is influenced by wall surface emissivity. The square cavity with continuous fins is more effective than square cavity with two fins on vertical isothermal walls.

  12. Heat exchanger with transpired, highly porous fins

    Science.gov (United States)

    Kutscher, Charles F.; Gawlik, Keith

    2002-01-01

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

  13. 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).

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

    Science.gov (United States)

    Siegel, R.; Graham, R. W.

    1977-01-01

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

  15. 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."

  16. Radiation

    International Nuclear Information System (INIS)

    2013-01-01

    The chapter one presents the composition of matter and atomic theory; matter structure; transitions; origin of radiation; radioactivity; nuclear radiation; interactions in decay processes; radiation produced by the interaction of radiation with matter

  17. 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

  18. ORTHOPEDIC LEG BRACE

    Science.gov (United States)

    Myers, William Neil (Inventor)

    2005-01-01

    Knee braces generally have been rigid in both the knee bending direction and in the knee straightening direction unless a manually operated release is incorporated in them to allow the knee to bend. Desirably a braced knee joint should effectively duplicate the compound, complex, actions of a normal knee. The key to knee braces is the knee joint housing. The housing herein carries a number of cam action pawls. with teeth adapted to engage the internal teeth of a ratchet ring mounted in the housing. Cam action return springs and the shape of the cam action pawl teeth allow rotation of the ratchet ring in a leg straightening direction while still supporting a load. The leg can then be extended during walking while at the same time being prevented by the cam action pawls from buckling in the knee bending direction.

  19. Legāti

    OpenAIRE

    Segliņa, Aiga

    2010-01-01

    Autore teorētiski analizē legāta jēdzienu testamentārās mantošanas ietvaros un atspoguļo praktiska pētījuma rezultātus. Teorētiskā daļa apskata legāta nodibināšanas formu un spēkā esamību, tā iegūšanu un atraidīšanu, izpildi un zaudēšanu, novēlējuma robežas un aprobežojumus. Pētījums veikts aptaujas veidā ar mērķi noskaidrot, cik liela Latvijas iedzīvotāju daļa apzinās legāta nodrošinātās priekšrocības testamentārajā mantošanā. Apskatīts notāra neitralitātes jautājums attiecībā pret mantošana...

  20. Stable walking with asymmetric legs

    International Nuclear Information System (INIS)

    Merker, Andreas; Rummel, Juergen; Seyfarth, Andre

    2011-01-01

    Asymmetric leg function is often an undesired side-effect in artificial legged systems and may reflect functional deficits or variations in the mechanical construction. It can also be found in legged locomotion in humans and animals such as after an accident or in specific gait patterns. So far, it is not clear to what extent differences in the leg function of contralateral limbs can be tolerated during walking or running. Here, we address this issue using a bipedal spring-mass model for simulating walking with compliant legs. With the help of the model, we show that considerable differences between contralateral legs can be tolerated and may even provide advantages to the robustness of the system dynamics. A better understanding of the mechanisms and potential benefits of asymmetric leg operation may help to guide the development of artificial limbs or the design novel therapeutic concepts and rehabilitation strategies.

  1. 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....

  2. 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...

  3. Effect of Fin Porosity on Wake Geometry for Flapping Fins at Intermediate Reynolds Number

    Science.gov (United States)

    Chen, J.; Xia, B.; Krueger, P. S.

    2017-11-01

    Low aspect ratio flapping fins generate interesting 3-dimensional flow structures as has been observed, for example, in studies of fish swimming. As the Reynolds number is reduced, the exact geometry of the fin is less important and even certain amounts of porosity might be allowed without significantly affecting propulsive performance. These effects are investigated experimentally using flapping rectangular fins of aspect ratio 2 at Reynolds numbers in the range 100 - 1000. The experiments were conducted using a water tunnel to supply the free stream flow and the fin flapping parameters were set to provide a Strouhal number (based on amplitude of the fin tip motion) in the range 0.15 - 0.35. Phase-averaged measurements were made of the 3-dimensional, volumetric flow field, allowing visualization of the typical shed vortex structure behind the fin and calculation of time averaged thrust and propulsive efficiency. Results comparing the flow structure in the fin wake and the resulting propulsive performance will be presented for several fins with different planform porosities where the porosities are set using arrays of holes in the fins. This material is based on the work supported by the National Science Foundation under Grant No. 1510707.

  4. 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.

  5. 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)

  6. Leg cramps and restless legs syndrome during pregnancy.

    Science.gov (United States)

    Hensley, Jennifer G

    2009-01-01

    Sleep disturbance during pregnancy can result in excessive daytime sleepiness, diminished daytime performance, inability to concentrate, irritability, and the potential for an increased length of labor and increased risk of operative birth. Sleep disturbance may be the result of a sleep disorder, such as leg cramps, a common yet benign disorder, or restless legs syndrome, a sensorimotor disorder. Both disrupt sleep, are distressing to the pregnant woman, and mimic one another and other serious disorders. During pregnancy, up to 30% of women can be affected by leg cramps, and up to 26% can be affected by restless legs syndrome.

  7. [Swollen leg with blisters].

    Science.gov (United States)

    Rafeiner, Ph; Templeton, A J; Vonesch, H J

    2005-10-05

    We report the case of a 84-year-old woman suffering from strong pain in her right leg initially resembling thrombosis of deep veins. Eight hours after admission a superficial blister developed at the calf with following hemorrhagic aspect and spontanous eruption of clear yellowish fluid. Later on a new blister appeared at the thigh. The patient died 33 hours after admission of streptococcal toxic shock syndrome. The latter was based on a necrotizing fasciitis. Streptoccus pyogenes (group A) could be cultivated from the blood and fluid of the blister. We discuss the clinical presentation of necrotizing fasciitis with "pain out of proportion" as characteristic complaint and the appropriate management.

  8. Textiloma in the leg

    Directory of Open Access Journals (Sweden)

    Patel Amol

    2007-01-01

    Full Text Available Textiloma is defined as a tumor formed due to retained gauze. It is rarely reported in the musculoskeletal system. We are presenting a case with a soft tissue swelling over the lateral aspect of the lower third of the leg, come for implant removal of the distal tibia and fibular fracture. We removed the soft tissue mass enbloc thinking it to be a benign tumor. On cutting the mass on the operation table, a gauze piece encased by fibrous tissue was found. Textiloma can present as tumoral forms and can mimic as a pseudo-tumor.

  9. Optimum design of a radial heat sink with a fin-height profile for high-power LED lighting applications

    International Nuclear Information System (INIS)

    Jang, Daeseok; Yook, Se-Jin; Lee, Kwan-Soo

    2014-01-01

    Highlights: • A radial heat sink was designed for high-power LED lighting applications. • Fin-height profiles reflecting the chimney-flow characteristics of a radial heat sink were proposed. • Multi-disciplinary optimization was carried out to simultaneously minimize the thermal resistance and mass. • The cooling performance of the optimized design showed improvement without additional mass increment. - Abstract: Light-emitting diode (LED) lighting offers greater energy efficiency than conventional lighting. However, if the heat from the LEDs is not properly dissipated, the lifespan and luminous efficiency are diminished. In the present study, a heat sink of LED lighting was optimized with respect to its fin-height profile to obtain reliable cooling performance for high-power LED lighting applications. Natural convection and radiation heat transfer were taken into consideration and an experiment was conducted to validate the numerical model. Fin-height profiles reflecting a three-dimensional chimney-flow pattern were proposed. The outermost fin height, the difference between fin heights, and the number of fin arrays were adopted as design variables via sensitivity analysis, and the heat sink configuration was optimized in three dimensions. Optimization was conducted to simultaneously minimize the thermal resistance and mass. The result was compared with the Pareto fronts of a plate-fin heat sink examined in a previous study. The cooling performance of the optimized design showed an improvement of more than 45% while preserving a mass similar to that of the plate-fin heat sink

  10. Study of noise sources of image for optimization of radiation doses in skull computerized tomography; Estudo das fontes de ruido da imagem para fins de otimizacao das doses na tomografia computadorizada de cranio

    Energy Technology Data Exchange (ETDEWEB)

    Medeiros, R.B.; Garos, K.A.C. [UNIFESP - Universidade Federal de Sao Paulo, SP (Brazil)]. E-mail: rbitelli@cfrh.epm.br

    2001-07-01

    Our goal was to evaluate the exposure factors that can change the image noise of head CT in different slices thicknesses. We have evaluated the images noise at several mAs varying from 50 to 800 mAs for 100, 120 and 140 kVp as tension values. The images uniformity were determined for all technical exposure conditions. We did not observed any important noise reduction for values up 200 mAs which can justify the increase of radiation doses through the increase of mAs. (author)

  11. 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.

  12. Hegel y el fin del arte

    Directory of Open Access Journals (Sweden)

    Óscar Cubo Ugarte

    2010-03-01

    Full Text Available Uno de los puntos de mayor interés del pensamiento estético de Hegel procede de sus Lecciones de estética, y es aquel que afirma y tematiza el fin del arte. Para entender el sentido y el alcance de esta idea, presentamos en este trabajo el modo como Hegel trata el problema del arte dentro de su filosofía especulativa y en especial en sus Lecciones de Estética. Por medio de este proceso de contextualización rastreamos finalmente las distintas interpretaciones que se han producido en nuestros días acerca de la provocativa tesis del fin del arte y dejamos planteada también la cuestión del lugar que ocupa o puede ocupar el arte después del mencionado fin del arte.

  13. Differentiating nocturnal leg cramps and restless legs syndrome.

    Science.gov (United States)

    Rana, Abdul Qayyum; Khan, Fatima; Mosabbir, Abdullah; Ondo, William

    2014-07-01

    Leg pain and discomfort are common complaints in any primary physician's clinic. Two common causes of pain or discomfort in legs are nocturnal leg cramps (NLC) and restless leg syndrome (RLS). NLC present as painful and sudden contractions mostly in part of the calf. Diagnosis of NLC is mainly clinical and sometimes involves investigations to rule out other mimics. RLS is a condition characterized by the discomfort or urge to move the lower limbs, which occurs at rest or in the evening/night. The similarity of RLS and leg cramps poses the issue of errors in diagnosing and differentiating the two. In this paper we review the pathopysiology of each entity and their diagnosis as well as treatment. The two conditions are then compared to appreciate the differences and similarities. Finally, suggestions are recommended for complete assessment.

  14. Heat Transfer Analysis of Fin Tube

    International Nuclear Information System (INIS)

    Jeon, Woo-Jin; Choi, Cheng-Ryul

    2015-01-01

    This paper describes a preliminary numerical analysis of fin tube used for a heat exchanger of the air-water cooling system. The internal flow in a fin tube is steam and the external of the fin is cooled by air. Cooling system in a nuclear power plant can be divided into two categories; 1) active pump driven system powered by alternating current and 2) passive cooling system drived by natural circulation phenomena. After the accident in Hukushima Nuclear Power Plants, the importance of the passive cooling system that can provide a long-term cooling of reactor decay heat during station blackout condition is emphasized. However, the effectiveness of passive cooling system based on cooling water is limited by the capacity of water storage tank. To overcome the limit due to the exhaustion of the cooling water, an natural convection air cooling system is proposed. As the air operated cooling system utilizes natural circulation phenomena of air, it does not require cooling water. However, the heat transfer area of the air operated cooling system should be increased much as the heat removal capacity per unit area is much lower than that of water cooling system. The air-water combined cooling system can resolve this excess increase of the heat transfer area in the air operated cooling system. This air-water cooling system can be also used in the passive containment cooling system. The effect of design parameters such as fin tube arrangement, the fin height, and pitch has been analyzed and the chimney effect on the simulation of heat transfer in a heat exchanger is evaluated. The internal flows in a fin tube heat exchanger for natural circulation flow condition and forced convection (suction) condition were investigated

  15. Superconducting niobium cavity with cooling fins

    International Nuclear Information System (INIS)

    Isagawa, Shigeru.

    1978-04-01

    Cooling efficiency of a superconducting cavity is shown to be improved by applying a fin structure. Internal heating can be suppressed in a certain degree and the higher rf field is expected to be reached on surfaces of the cavity which is immersed in superfluid He 4 liquid. The rf measurements were made on a C-band niobium cavity with cylindrical and circular fins around the wall. Fields of 39 mT and 25 MV/m were attained for TM 010 mode cavity after surface treatments including high temperature annealing in a UHV furnace. (auth.)

  16. Klinefelter Syndrome With Leg Ulcers

    Directory of Open Access Journals (Sweden)

    Narendra G

    1999-01-01

    Full Text Available Leg ulcers are frequently caused by venous insufficiency, arterial insufficiency, neuropathy, or a combination of these factors. Klinefelter syndrome in association with chronic leg ulcers have been reported earlier. We report a case of Klinefelter syndrome with non- healing ulcer. The diagnosis of the Klinefelter syndrome was confirmed by karyotyping.

  17. Leg CT scan

    Science.gov (United States)

    ... your provider if you take the diabetes medicine metformin (Glucophage). You may need to take extra steps ... to contrast dye Birth defect if done during pregnancy CT scans expose you to more radiation than ...

  18. FinTech Adoption Across Generations

    DEFF Research Database (Denmark)

    Carlin, Bruce; Olafsson, Arna; Pagel, Michaela

    This paper analyzes how better access to financial information via new technology changes use of consumer credit and affects financial fitness. We exploit the introduction of a smartphone application for personal financial management as a source of exogenous variation. FinTech adoption reduces...

  19. 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

  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. 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...

  2. Restless legs syndrome

    Directory of Open Access Journals (Sweden)

    Ovallath S

    2012-10-01

    Full Text Available Sujith Ovallath, P DeepaJames Parkinson's Movement Disorder Research Centre, Kannur Medical College, Kerala, IndiaBackground: Restless legs syndrome (RLS is a common sleep-related disorder characterized by abnormal sensation and an urge to move the lower limbs. Symptoms occur at rest in the evening or at night, and they are alleviated by moving the affected extremity or by walking. Although the exact etiopathogenesis of RLS remains elusive, the rapid improvement of symptoms with dopaminergic agents suggests that dopaminergic system dysfunction may be a basic mechanism. Dopaminergic agents are the best-studied agents, and are considered first-line treatment of RLS.Objective: To review the diagnostic criteria, clinical features, etiopathogenesis, and the treatment options of RLS.Methods: The suggestions are based on evidence from studies published in peer-reviewed journals, or upon a comprehensive review of the medical literature.Results/conclusion: Extensive data are available for proving the link between the dopaminergic system and RLS. A possible genetic link also has been studied extensively. Dopamine agonists, especially pramipexole and ropinirole, are particularly useful in the treatment of RLS. Pharmacological treatment should however be limited to those patients who suffer from clinically relevant RLS with impaired sleep quality or quality of life.Keywords: dopamine, levodopa, pramipexole

  3. Restless legs syndrome: literature review

    Directory of Open Access Journals (Sweden)

    Emmanouil Symvoulakis

    Full Text Available Restless legs syndrome is a distressing condition, with negative effects on sleep and daytime activities that affect personal, family and occupational life. The overall impact of restless legs syndrome on quality of life is comparable to that of chronic and frustrating conditions such as depression and diabetes. Misdiagnosis and inappropriate treatment may increase patients' suffering in terms of uncertainty, overuse or misuse of care services and lack of trust. Presenting a synthesis of the main topics in the literature on restless legs syndrome facilitates for a better understanding and its management in primary care settings.

  4. Measurement of body fat using leg to leg bioimpedance

    OpenAIRE

    Sung, R; Lau, P; Yu, C; Lam, P; Nelson, E

    2001-01-01

    AIMS—(1) To validate a leg to leg bioimpedance analysis (BIA) device in the measurement of body composition in children by assessment of its agreement with dual energy x ray absorptiometry (DXA) and its repeatability. (2) To establish a reference range of percentage body fat in Hong Kong Chinese children.
METHODS—Sequential BIA and DXA methods were used to determine body composition in 49 children aged 7-18 years; agreement between the two methods was calculated. Repea...

  5. CTH Analyses of Fragment Penetration Through Heat Sink Fins

    National Research Council Canada - National Science Library

    Prakash, Anand

    2005-01-01

    .... This report presents more detailed calculations of the penetration and perforation of an electronic box with cooling fins by a high velocity fragment that strikes the fins with an oblique impact...

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

    Science.gov (United States)

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

    2004-09-14

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

  7. Leg pain and gynecologic malignancy.

    Science.gov (United States)

    Singh, Lilly; Stevens, Erin E

    2013-09-01

    Gynecologic malignancies affect more than 83 000 women in the United States, each year. Because the disease involves the pelvis, many patients have side effects distal to this area in their lower extremities. The differential diagnosis of leg pain can be divided into vascular, neurologic, and musculoskeletal causes. In this review article, we address numerous etiologies of leg pain, reviewing the prevalence of disease, physical examination findings, diagnostic as well as treatment modalities.

  8. 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

    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......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...... 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...

  9. 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...

  10. Studying Fin Whales with Seafloor Seismic Networks

    Science.gov (United States)

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

    2011-12-01

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

  11. 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.)

  12. The Fifth International Ice Nucleation Workshop Activities FIN-1 and FIN-2: Overview and Selected Results

    Science.gov (United States)

    Moehler, O.; Cziczo, D. J.; DeMott, P. J.; Hiranuma, N.; Petters, M. D.

    2015-12-01

    The role of aerosol particles for ice formation in clouds is one of the largest uncertainties in understanding the Earth's weather and climate systems, which is related to the poor knowledge of ice nucleation microphysics or of the nature and atmospheric abundance of ice nucleating particles (INPs). During the recent years, new mobile instruments were developed for measuring the concentration, size and chemical composition of INPs, which were tested during the three-part Fifth International Ice Nucleation (FIN) workshop. The FIN activities addressed not only instrument issues, but also important science topics like the nature of atmospheric INP and cloud ice residuals, the ice nucleation activity of relevant atmospheric aerosols, or the parameterization of ice formation in atmospheric weather and climate models. The first activity FIN-1 was conducted during November 2014 at the AIDA cloud chamber. It involved co-locating nine single particle mass spectrometers to evaluate how well they resolve the INP and ice residual composition and how spectra from different instruments compare for relevant atmospheric aerosols. We conducted about 90 experiments with mineral, carbonaceous and biological aerosol types, some also coated with organic and inorganic compounds. The second activity FIN-2 was conducted during March 2015 at the AIDA facility. A total of nine mobile INP instruments directly sampled from the AIDA aerosol chambers. Wet suspension and filter samples were also taken for offline INP processing. A refereed blind intercomparison was conducted during two days of the FIN-2 activity. The third activity FIN-3 will take place at the Desert Research Institute's Storm Peak Laboratory (SPL) in order to test the instruments' performance in the field. This contribution will introduce the FIN activities, summarize first results from the formal part of FIN-2, and discuss selected results, mainly from FIN-1 for the effect of coating on the ice nucleation (IN) by mineral

  13. Restless Legs Syndrome and Leg Motor Restlessness in Parkinson's Disease.

    Science.gov (United States)

    Suzuki, Keisuke; Miyamoto, Masayuki; Miyamoto, Tomoyuki; Hirata, Koichi

    2015-01-01

    Sleep disturbances are important nonmotor symptoms in Parkinson's disease (PD) that are associated with a negative impact on quality of life. Restless legs syndrome (RLS), which is characterized by an urge to move the legs accompanied by abnormal leg sensations, can coexist with PD, although the pathophysiology of these disorders appears to be different. RLS and PD both respond favorably to dopaminergic treatment, and several investigators have reported a significant relationship between RLS and PD. Sensory symptoms, pain, motor restlessness, akathisia, and the wearing-off phenomenon observed in PD should be differentiated from RLS. RLS in PD may be confounded by chronic dopaminergic treatment; thus, more studies are needed to investigate RLS in drug-naïve patients with PD. Recently, leg motor restlessness (LMR), which is characterized by an urge to move the legs that does not fulfill the diagnostic criteria for RLS, has been reported to be observed more frequently in de novo patients with PD than in age-matched healthy controls, suggesting that LMR may be a part of sensorimotor symptoms intrinsic to PD. In this paper, we provide an overview of RLS, LMR, and PD and of the relationships among these disorders.

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

    Science.gov (United States)

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

    2017-02-01

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

  15. Effect of supply voltage and body-biasing on single-event transient pulse quenching in bulk fin field-effect-transistor process

    International Nuclear Information System (INIS)

    Yu Jun-Ting; Chen Shu-Ming; Chen Jian-Jun; Huang Peng-Cheng; Song Rui-Qiang

    2016-01-01

    Charge sharing is becoming an important topic as the feature size scales down in fin field-effect-transistor (FinFET) technology. However, the studies of charge sharing induced single-event transient (SET) pulse quenching with bulk FinFET are reported seldomly. Using three-dimensional technology computer aided design (3DTCAD) mixed-mode simulations, the effects of supply voltage and body-biasing on SET pulse quenching are investigated for the first time in bulk FinFET process. Research results indicate that due to an enhanced charge sharing effect, the propagating SET pulse width decreases with reducing supply voltage. Moreover, compared with reverse body-biasing (RBB), the circuit with forward body-biasing (FBB) is vulnerable to charge sharing and can effectively mitigate the propagating SET pulse width up to 53% at least. This can provide guidance for radiation-hardened bulk FinFET technology especially in low power and high performance applications. (paper)

  16. Restless legs syndrome and periodic leg movements of sleep.

    Science.gov (United States)

    Rye, David B; Trotti, Lynn Marie

    2012-11-01

    Women are more commonly affected than men by restless legs syndrome, and prevalence is highest amongst those of northern European heritage. The motor manifestations include nonvolitional myoclonus (periodic leg movements). Disinhibition of spinal sensorimotor circuits may underlie these primary features and can be affected by peripheral as well as supraspinal networks. Insufficient mobilizable iron stores increase expressivity in some individuals. The sensorimotor features are relieved by dopamine, especially dopamine agonists, gabapentin and its derivatives, and opioids. A diagnosis relies on recognition of key primary and supportive features, and treatments are generally well tolerated, efficacious, and life-changing. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. Radiation

    International Nuclear Information System (INIS)

    Davidson, J.H.

    1986-01-01

    The basic facts about radiation are explained, along with some simple and natural ways of combating its ill-effects, based on ancient healing wisdom as well as the latest biochemical and technological research. Details are also given of the diet that saved thousands of lives in Nagasaki after the Atomic bomb attack. Special comment is made on the use of radiation for food processing. (U.K.)

  18. Promethus Hot Leg Piping Concept

    International Nuclear Information System (INIS)

    AM Girbik; PA Dilorenzo

    2006-01-01

    The Naval Reactors Prime Contractor Team (NRPCT) recommended the development of a gas cooled reactor directly coupled to a Brayton energy conversion system as the Space Nuclear Power Plant (SNPP) for NASA's Project Prometheus. The section of piping between the reactor outlet and turbine inlet, designated as the hot leg piping, required unique design features to allow the use of a nickel superalloy rather than a refractory metal as the pressure boundary. The NRPCT evaluated a variety of hot leg piping concepts for performance relative to SNPP system parameters, manufacturability, material considerations, and comparison to past high temperature gas reactor (HTGR) practice. Manufacturability challenges and the impact of pressure drop and turbine entrance temperature reduction on cycle efficiency were discriminators between the piping concepts. This paper summarizes the NRPCT hot leg piping evaluation, presents the concept recommended, and summarizes developmental issues for the recommended concept

  19. Leg ulcers due to hyperhomocysteinemia

    Directory of Open Access Journals (Sweden)

    Krupa Shankar D

    2006-01-01

    Full Text Available Chronic leg ulcers are rare in young adults and generally indicate a vascular cause. We report a case of a 26-year-old man with leg ulcers of eight months duration. Doppler study indicated venous incompetence and a postphlebitic limb. However, as the distribution and number of ulcers was not consistent with stasis alone and no features of collagen vascular disease were noted, a hyperviscosity state was considered and confirmed with significantly elevated homocysteine level in the serum. Administration of vitamins B1, B2, B6 and B12, trimethyl-glycine, mecobalamine, folic acid and povidone iodine dressings with culture-directed antibiotic therapy led to a satisfactory healing of ulcers over a period of one month. Hyperhomocysteinemia must be considered in the differential diagnosis of leg ulcers in young individuals.

  20. A highly adaptive magnetorheological fluid robotic leg for efficient terrestrial locomotion

    Science.gov (United States)

    Jiang, Nan; Sun, Shuaishuai; Ouyang, Yiming; Xu, Min; Li, Weihua; Zhang, Shiwu

    2016-09-01

    To survive in nature, animals adjust the characteristics of their legs or fins to adapt the motion to their environment. Inspired by the locomotion of animals, a study on the tunable stiffness and damping of a leg will help in the development of intelligent locomotion robots. In this paper we report on the development and experiment of a novel and simple robotic leg that can be adapted to the environment via a smart magnetorheological fluid (MRF). The robotic leg consists of a rotation MRF damper, a torsional spring, a ‘foot’ and a ‘leg’. The curved part of the ‘foot’ makes contact with the grounds while the other end is linked to an outer cylinder of the MRF damper with an inelastic cable. The variable force arm rising from the MRF damper and the torsional spring can help the leg adapt to a changing environment. The characteristics of the MRF damper have been investigated and a model is built to describe its mechanical features when different currents are applied to the MRF damper. A test on a linear dynamic test instrument has been conducted to verify the accuracy of the model. The robotic leg is installed in a locomotion platform to investigate the speed of its locomotion and the cost of the transport; the result demonstrated the feasibility and adaptability of the leg when walking on hard terrain. Its simple structure, high adaptability, and easy control of the MRF leg helped in the design and development of a high performance field robot that can adapt to various environments.

  1. 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...

  2. 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.

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

    Science.gov (United States)

    Hardy, Adam R.; Steinworth, Bailey M.

    2016-01-01

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

  4. Hydrodynamics of a freely movable flexible fin near the ground

    Science.gov (United States)

    Jeong, Young Dal; Lee, Jae Hwa

    2017-11-01

    In the present study, a freely movable flexible fin is numerically modelled to investigate the flapping dynamics of the fin near the ground in a Poiseuille flow. A leading edge of the fin is fixed in the streamwise direction, whereas the lateral motion is spontaneously determined by hydrodynamic interaction between the fin and surrounding fluid. When the fin is initially positioned at yo, the fin passively migrates toward another wall-normal position for an equilibrium state by the interaction between passively flapping flexible body and ground. At the equilibrium position, the drag coefficient of the fin (CD) significantly decreases due to decaying of the flapping and low flow velocity and the fin can swim consistently without the time-averaged lateral force. Two distinctive behavior at the transient state (flapping and non-flapping migration modes) and three distinctive behaviors at the equilibrium state (deflected-straight, large- and small-amplitude flapping modes) are observed depending on the bending rigidity (γ) and mass ratio (μ) of the fin. The equilibrium position of the fin is investigated as a function of initial position (yo) , bending rigidity (γ) , mass ratio (μ) and the Reynolds number (Re). This research was supported by the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2017R1D1A1A09000537) and the Ministry of Science, ICT & Future Planning (NRF-2017R1A5A1015311).

  5. Cross-legged Gods and One-legged Foresters

    NARCIS (Netherlands)

    Petrovskaia, N.I.

    The present article is a re-evaluation of a marvellous element in a medieval Welsh romance, Chwedl Iarlles y Ffynnawn ‘Tale of the Lady of the Fountain’, also known as Owein. One of the characters encountered by the hero is a one-eyed one-legged dark giant forester who appears to have a particular

  6. 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

  7. The one-leg standing radiograph

    OpenAIRE

    Pinsornsak, P.; Naratrikun, K.; Kanitnate, S.; Sangkomkamhang, T.

    2016-01-01

    Objectives The purpose of this study was to compare the joint space width between one-leg and both-legs standing radiographs in order to diagnose a primary osteoarthritis of the knee. Methods Digital radiographs of 100 medial osteoarthritic knees in 50 patients were performed. The patients had undergone one-leg standing anteroposterior (AP) views by standing on the affected leg while a both-legs standing AP view was undertaken while standing on both legs. The severity of the osteoarthritis wa...

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

    Science.gov (United States)

    Dillman, Casey B; Hilton, Eric J

    2015-03-01

    Acipenseriformes hold an important place in the evolutionary history of bony fishes. Given their phylogenetic position as extant basal Actinopterygii, it is generally held that a thorough understanding of their morphology will greatly contribute to the knowledge of the evolutionary history and the origin of diversity for the major osteichthyan clades. To this end, we examined comparative developmental series from the pectoral girdle in Acipenser fulvescens, A. medirostris, A. transmontanus, and Scaphirhynchus albus to document, describe, and compare ontogenetic and allometric differences in the pectoral girdle. We find, not surprisingly, broad congruence between taxa in the basic pattern of development of the dermal and chondral elements of the pectoral girdle. However, we also find clear differences in the details of structure and development among the species examined in the dermal elements, including the clavicle, cleithrum, supracleithrum, posttemporal, and pectoral-fin spine. We also find differences in the internal fin elements such as the distal radials as well as in the number of fin rays and their association with the propterygium. Further, there are clear ontogenetic differences during development of the dermal and chondral elements in these species and allometric variation in the pectoral-fin spine. The characters highlighted provide a suite of elements for further examination in studies of the phylogeny of sturgeons. Determining the distribution of these characters in other sturgeons may aid in further resolution of phylogenetic relationships, and these data highlight the role that ontogenetic and comparative developmental studies provide in systematics. © 2014 Wiley Periodicals, Inc.

  9. A new species of Ituglanis from the Rio Xingu Basin, Brazil, and the evolution of pelvic fin loss in trichomycterid catfishes (Teleostei: Siluriformes: Trichomycteridae).

    Science.gov (United States)

    Datovo, Aléssio

    2014-04-22

    A new species of the trichomycterid catfish genus Ituglanis is described from the Rio Curuá, Rio Xingu basin, Rio Amazonas drainage, Brazil. Ituglanis apteryx, new species, is promptly distinguished from congeners, except some specimens of I. parahybae (Eigenmann), by the absence of pelvic fins, girdle, and muscles. The new species differs from I. parahybae in the pattern of the cephalic laterosensory system; the absence of a posterior cranial fontanel; the presence of an epural; and the number of branchiostegal rays, ribs, and vertebrae. Ituglanis apteryx is one among the several trichomycterids lacking pelvic fins. Analysis reveals that pelvic fin loss independently evolved several times during the trichomycterid radiation.

  10. Kan leg skabe fremtidens vindere?

    DEFF Research Database (Denmark)

    Holm, Claus

    2006-01-01

    Dansk Boldspil Union skruer ned for den præstationsorienterede tilgang til børnefodbold. I stedet skal børnenes leg med bolden i fokus. Målet er at forhindre massivt frafald i børne- og ungdomsfodbolden og højne niveauet hos topspillerne....

  11. Doppler ultrasound exam of an arm or leg

    Science.gov (United States)

    Peripheral vascular disease - Doppler; PVD - Doppler; PAD - Doppler; Blockage of leg arteries - Doppler; Intermittent claudication - Doppler; Arterial insufficiency of the legs - Doppler; Leg pain and ...

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

    Science.gov (United States)

    1985-03-01

    34. 7 e - Fin Height -F - Property Function g - Acceleration of Gravity G - Condensate Flow Rate Gf - Rate of Condensate Formation h - Steam...interaction of gravitational and surface-tension forces lead to complex - three-dimensional flow patterns, which are further dependent on fin spacing, height...and thickness. Other variables include heat flux, vapor shear, tube diameter, fin shape and fuid properties just to name a few. In view ofL the

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

    Science.gov (United States)

    2015-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Large Scale Density Estimation of Blue and Fin Whales ...sensors, or both. The goal of this research is to develop and implement a new method for estimating blue and fin whale density that is effective over...develop and implement a density estimation methodology for quantifying blue and fin whale abundance from passive acoustic data recorded on sparse

  14. Inverse determination of the heat transfer characteristics on a circular plane fin in a finned-tube bundle

    Energy Technology Data Exchange (ETDEWEB)

    Benmachiche, Abdelmoumene Hakim [University of Biskra, Department of Mechanics, Biskra (Algeria); Bougriou, Cherif [University of Batna, LESEI FSI Department of Mechanics, Batna (Algeria); Abboudi, Said [UTBM, Department of Mechanical Engineering, SET Laboratory, Belfort (France)

    2010-12-15

    In this work, we present the numerical results of the average heat transfer coefficients, h{sub {phi}}, over a circular plane fin in a finned-tube bundle for both aligned and staggered arrangements as well as the fin efficiency and the heat flux dissipated from the whole fin. The study covers a wide range of Reynolds number (2 x 10{sup 3}-3 x 10{sup 4}), for three different positions of the finned tube inside the heat exchanger. The temperature distribution on the fins surfaces was obtained experimentally using infrared thermography technique. The predicted values of the heat transfer coefficient were obtained numerically using the finite element method in conjunction with the conjugate gradient algorithm and the measured temperatures. (orig.)

  15. 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 sc ), in the case of reflectors installed, was reinforced.

  16. Fin o metamorfosis de la escuela

    Directory of Open Access Journals (Sweden)

    José Joaquín Brunner

    1996-10-01

    Full Text Available El autor adhiere a la idea de que la escuela una es una de las matrices de la modernidad por cuanto separa la transmisión cultural de cualquier soporte físico (escritura, radicándola en el propio proceso de escolarización: su gramática consistiría en redes de clasificación del conocimiento, siendo el orden escolar esencialmente un procedimiento; el juego que juega la escuela es el de la obtención de los usos de adquisición del conocimiento. De esta forma el “fin de la escritura” como tecnología predominante del conocimiento, significara el conocimiento de una nueva era de escolarización.

  17. A comparison of one-legged and two-legged countermovement jumps

    NARCIS (Netherlands)

    van Soest, A J; Roebroeck, M.E.; Bobbert, M F; Huijing, P A; van Ingen Schenau, G J

    1985-01-01

    Ten well-trained male volleyball players performed one-legged and two-legged vertical countermovement jumps. Ground reaction forces, cinematographic data, and electromyographic data were recorded. Jumping height in one-legged jumps was 58.5% of that reached in two-legged jumps. Mean net torques in

  18. 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.

  19. 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

  20. Pectoral fin locomotion in batoid fishes: undulation versus oscillation.

    Science.gov (United States)

    Rosenberger, L J

    2001-01-01

    This study explores the dichotomy between undulatory (passing multiple waves down the fin or body) and oscillatory (flapping) locomotion by comparing the kinematics of pectoral fin locomotion in eight species of batoids (Dasyatis americana, D. sabina, D. say, D. violacea, Gymnura micrura, Raja eglanteria, Rhinobatos lentiginosus and Rhinoptera bonasus) that differ in their swimming behavior, phylogenetic position and lifestyle. The goals of this study are to describe and compare the pectoral fin locomotor behavior of the eight batoid species, to clarify how fin movements change with swimming speed for each species and to analyze critically the undulation/oscillation continuum proposed by Breder using batoids as an example. Kinematic data were recorded for each species over a range of swimming velocities (1-3 disc lengths s(-1)). The eight species in this study vary greatly in their swimming modes. Rhinobatos lentiginosus uses a combination of axial-based and pectoral-fin-based undulation to move forward through the water, with primary thrust generated by the tail. The pectoral fins are activated in short undulatory bursts for increasing swimming speed and for maneuvering. Raja eglanteria uses a combination of pectoral and pelvic locomotion, although only pectoral locomotion is analyzed here. The other six species use pectoral locomotion exclusively to propel themselves through the water. Dasyatis sabina and D. say have the most undulatory fins with an average of 1.3 waves per fin length, whereas Rhinoptera bonasus has the most oscillatory fin behavior with 0.4 waves per fin length. The remaining species range between these two extremes in the degree of undulation present on their fins. There is an apparent trade-off between fin-beat frequency and amplitude. Rhinoptera bonasus has the lowest frequency and the highest fin amplitude, whereas Rhinobatos lentiginosus has the highest frequency and the lowest amplitude among the eight species examined. The kinematic

  1. [Restless legs syndrome and nocturnal leg pain : Differential diagnosis and treatment].

    Science.gov (United States)

    Hornyak, M; Stiasny-Kolster, K; Evers, S; Happe, S

    2011-09-01

    Pain in the legs belongs to the five most frequent regional pain symptoms. Restless legs syndrome (RLS) presents a particular differential diagnosis for pain in the legs, which is characterized by a nocturnal urge to move the legs often associated with painful sensations in the legs. It is one of the most common neurological disorders and probably the leading cause of nocturnal pain in the legs. In this overview, the diagnosis and therapy of RLS as well as aspects of pain therapy of the disorder are presented. In addition, the differential diagnoses for exclusion of other specific causes of nocturnal pain in the legs are discussed.

  2. Heat transfer and flow characteristics around a finned-tube bank heat exchanger in fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Honda, Ryosuke [Department of Mechanical Engineering, Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-8680 (Japan); Umekawa, Hisashi [Department of Mechanical Engineering, Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-8680 (Japan)], E-mail: umekawa@kansai-uac.jp; Ozawa, Mamoru [Department of Mechanical Engineering, Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-8680 (Japan)

    2009-06-21

    Principal heat transfer mechanisms in a fluidized bed have been classified into three categories, i.e. solid convection, gas convection and radiation. Among these mechanisms, the solid convection is a dominant mechanism in the bubbling fluidized bed. This solid convection is substantially caused by the bubble movement, thus the visualization of the void fraction distribution becomes a very useful method to understand the characteristics of the fluidized-bed heat exchanger. In this study, the heat transfer coefficient and the void fraction around the heat transfer tube with annuler fin were measured. For the quantitative measurement of the void fraction, neutron radiography and image processing technique were employed. Owing to the existence of the annuler fin, the restriction of the particle movements was put. This restriction suppressed the disturbance caused by tubes, and the influence of the tube arrangement on the flow and heat transfer characteristics could be clearly expressed.

  3. Heat transfer and flow characteristics around a finned-tube bank heat exchanger in fluidized bed

    International Nuclear Information System (INIS)

    Honda, Ryosuke; Umekawa, Hisashi; Ozawa, Mamoru

    2009-01-01

    Principal heat transfer mechanisms in a fluidized bed have been classified into three categories, i.e. solid convection, gas convection and radiation. Among these mechanisms, the solid convection is a dominant mechanism in the bubbling fluidized bed. This solid convection is substantially caused by the bubble movement, thus the visualization of the void fraction distribution becomes a very useful method to understand the characteristics of the fluidized-bed heat exchanger. In this study, the heat transfer coefficient and the void fraction around the heat transfer tube with annuler fin were measured. For the quantitative measurement of the void fraction, neutron radiography and image processing technique were employed. Owing to the existence of the annuler fin, the restriction of the particle movements was put. This restriction suppressed the disturbance caused by tubes, and the influence of the tube arrangement on the flow and heat transfer characteristics could be clearly expressed.

  4. Wings versus legs in the avian bauplan: development and evolution of alternative locomotor strategies.

    Science.gov (United States)

    Heers, Ashley M; Dial, Kenneth P

    2015-02-01

    Wings have long been regarded as a hallmark of evolutionary innovation, allowing insects, birds, and bats to radiate into aerial environments. For many groups, our intuitive and colloquial perspective is that wings function for aerial activities, and legs for terrestrial, in a relatively independent manner. However, insects and birds often engage their wings and legs cooperatively. In addition, the degree of autonomy between wings and legs may be constrained by tradeoffs, between allocating resources to wings versus legs during development, or between wing versus leg investment and performance (because legs must be carried as baggage by wings during flight and vice versa). Such tradeoffs would profoundly affect the development and evolution of locomotor strategies, and many related aspects of animal ecology. Here, we provide the first evaluation of wing versus leg investment, performance and relative use, in birds-both across species, and during ontogeny in three precocial species with different ecologies. Our results suggest that tradeoffs between wing and leg modules help shape ontogenetic and evolutionary trajectories, but can be offset by recruiting modules cooperatively. These findings offer a new paradigm for exploring locomotor strategies of flying organisms and their extinct precursors, and thereby elucidating some of the most spectacular diversity in animal history. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  5. 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.

  6. Numerical investigation to study effect of radiation on thermal performance of radiator for onan cooling configuration of transformer

    Science.gov (United States)

    Chandak, V.; Paramane, S. B.; Veken, W. V. d.; Codde, J.

    2015-09-01

    In the present work, flow and temperature distribution in the radiator fins of a power transformer is studied numerically with conjugate heat transfer using commercial CFD software to study the effect of radiation on heat dissipation. The approach considered here is a complete 3D geometry of the radiator fins with average height of the flute geometry of the fins for meshing and computational time reduction. Simulations are performed for ONAN (Oil Natural Air Natural) case for one radiator configuration. The simulations also study the effect of radiation and its impact on the overall heat dissipation. These results would give a holistic picture of heat transfer phenomenon to the designers.

  7. [Etiological diagnosis of leg ulcers].

    Science.gov (United States)

    Debure, Clélia

    2010-09-20

    Etiological diagnosis of leg ulcers must be the first step of treatment, even if we know that veinous disease is often present. We can build a clinical decisional diagram, which helps us to understand and not forget the other causes of chronic wounds and choose some basic examination, like ultrasound and histological findings. This diagnosis helps to choose the right treatment in order to cure even the oldest venous ulcers. Educational programs should be improved to prevent recurrence.

  8. Bone regenerates via dedifferentiation of osteoblasts in the zebrafish fin

    NARCIS (Netherlands)

    Knopf, F.; Hammond, C.J.; Chekuru, A.; Kurth, T.; Hans, S.; Weber, C.W.; Mahatma, G.; Fisher, S.; Brand, M.; Schulte-Merker, S.; Weidinger, G.

    2011-01-01

    While mammals have a limited capacity to repair bone defects, zebrafish can completely regenerate amputated bony structures of their fins. Fin regeneration is dependent on formation of a blastema, a progenitor cell pool accumulating at the amputation plane. It is unclear which cells the blastema is

  9. Strain characterization of FinFETs using Raman spectroscopy

    NARCIS (Netherlands)

    Kaleli, B.; van Hemert, T.; Hueting, Raymond Josephus Engelbart; Wolters, Robertus 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

  10. 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...

  11. Transient heat transfer in longitudinal fins of various profiles with ...

    Indian Academy of Sciences (India)

    may be constructed for the steady-state one-dimensional differential equation describing temperature distribution in a straight fin when the thermal conductivity is a constant and n = −1, 0, 1 and 2 [19]. The thermal conductivity of the fin may be assumed to vary linearly with the temperature for many engineering applications ...

  12. A characteristic correlation for heat transfer over serrated finned tubes

    International Nuclear Information System (INIS)

    Anoop, B.; Balaji, C.; Velusamy, K.

    2015-01-01

    Highlights: • Numerical investigation og heat transfer over serrated finned tubes. • Fins used on the outside of the tubes of a sodium to air heat exchanger. • RANS approach with RNG k–ε model to handle turbulence to handle closure. • Validation with in-house experiments. • Parametric studies culminating in a correlation for Nusselt number. - Abstract: Conjugate heat transfer from serrated fins on the outside of the tubes of a sodium to air tubular heat exchanger of sodium cooled fast breeder reactors, has been investigated by combined experimental and computational approaches. For the latter approach, the RNG k–ε model, which is applicable for a wide range of Reynolds numbers, was used for turbulence closure. The numerical model employed was validated by conducting in-house heat transfer experiments on a single serrated finned tube. A detailed parametric study has been carried out to investigate the effect of serration depth, fin pitch, fin height and fin thickness. In addition to pure cross flow, the effect of angle of attack of the flow on the heat transfer also has been studied. A correlation for determining the Nusselt number over a serrated finned tube has been proposed taking into account the serration parameters. This is expected to be useful in the design of sodium to air heat exchangers of fast breeder reactors

  13. The heat transfer of cooling fins on moving air

    Science.gov (United States)

    Doetsch, Hans

    1935-01-01

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

  14. 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...

  15. 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.

  16. 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

  17. Body Scars and Dorsal Fin Disfigurements as Indicators Interaction ...

    African Journals Online (AJOL)

    (Peponocephala electra) and short-finned pilot whales (Globicephala macrorhynchus). Injuries on the dorsal region (especially the dorsal fin) were characterised and related to fisheries or intra-/inter-specific interactions (with sharks and other cetacean species). The results suggest interactions with fisheries involving the ...

  18. Experimental Study on Horizontal Cylinders with Triangular Fins under Natural Convection

    Directory of Open Access Journals (Sweden)

    Gu-Won Lee

    2018-04-01

    Full Text Available In this study, thermal resistances of horizontal cylinders with triangular fins were measured in regard to fin numbers, fins heights, and temperature differences. Thereafter, an empirical correlation was proposed and validated for predicting the Nusselt numbers under the following conditions: Rayleigh number, 200,000–1,000,000; fin aspect ratio, 1.6–5.0; and fin number, 9–72. Finally, with the proposed correlation, the effects of fin numbers, fins heights, and fin thicknesses on the thermal resistances of the horizontal cylinders with triangular fins were investigated. It was shown that the thermal resistance generally increases as the fin number, fin height, and fin thickness increase. It is expected that horizontal cylinders for various cooling devices with triangular fins can be designed based on the findings of the present study.

  19. Gas chromatographic and electron spin resonance investigations of gamma-irradiated frog legs

    International Nuclear Information System (INIS)

    Morehouse, K.M.; Ku, Yuoh; Albrecht, H.L.; Yang, G.C.

    1991-01-01

    Several very sensitive techniques to measure radiation-induced products in frog legs were investigated. Presented here are results from the use of electron spin resonance (ESR) spectroscopy and capillary gas chromatography (GC) to measure radiolysis products in γ-irradiated frog legs. When bone is irradiated, a characteristic ESR signal develops and is easily measured. The intensity of the ESR signal is dose-dependent and stable for several months at room temperature. When triglycerides or fatty acids are irradiated, some of the major stable products formed are hydrocarbons with one less carbon than the precursor fatty acids. These hydrocarbons are formed as the result of the loss of CO 2 during various free radical reactions. A capillary GC procedure was developed to monitor the formation of these hydrocarbons in γ-irradiated frog legs. Since frog legs contain large amounts of palmitic, stearic, oleic, and linoleic acids, the formation of the hydrocarbons (pentadecane, heptadecane, 8-heptadecene, and 6,9-heptadecadiene, respectively) from the decarboxylation of these fatty acids was monitored. The yields of these hydrocarbons were found to be linear with applied dose. A sample from a lot of imported frog legs that were believed to have been treated with ionizing radiation was also analyzed. The ESR technique, in conjunction with the GC data on the hydrocarbons, appears to be a useful approach for identifying and monitoring frog legs that have been treated with ionizing radiation. (author)

  20. Thick legs - not always lipedema.

    Science.gov (United States)

    Reich-Schupke, Stefanie; Altmeyer, Peter; Stücker, Markus

    2013-03-01

    Due to its increased presence in the press and on television, the diagnosis of lipedema is on the way to becoming a trendy diagnosis for those with thick legs. Despite this, one must recognize that lipedema is a very rare disease. It is characterized by disproportional obesity of the extremities, especially in the region of the hip and the legs, hematoma development after minimal trauma, and increased pressure-induced or spontaneous pain. Aids for making the correct diagnosis are (duplex) sonography, the waist-hip index or the waist-height index and lymphoscintigraphy. Important differential diagnoses are constitutional variability of the legs, lipohypertrophy in obesity, edema in immobility, edema in chronic venous insufficiency and rheumatic diseases. The symptom-based therapy of lipedema consists of conservative (compression, manual lymphatic drainage, exercise) and surgical treatments (liposuction). Until now there is no curative therapy. Obesity is an important risk factor for the severity and prognosis of lipedema. Further studies for a better understanding of the pathogenesis of lipedema and in the end possible curative treatments are urgently needed. © The Authors | Journal compilation © Blackwell Verlag GmbH, Berlin.

  1. 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.

  2. Cooling characteristics of a strip fin heat sink

    International Nuclear Information System (INIS)

    Riu, Kap Jong; Park, Cheol Woo; Jang, Chung Sun; Kim, Hyun Woo

    2005-01-01

    Air-cooled heat sinks are employed in many electronic cooling applications since they provide significant heat transfer enhancement and operational flexibility. Strip-shaped fin heat sink is of interest and needs to be investigated as general cooling products for more applicability. The purposes of this study are to evaluate heat sink performance without bypass flow condition and to determine optimal heat sink geometries. The results show that the decreasing rate of thermal resistance of a heat sink decreases with increasing inlet air velocity, and the increasing rate of pressure drop increases with increasing inlet air velocity, but is not affected by input power. The increasing rate of optimal longitudinal fin spacing is larger than that of transverse fin spacing. The strip fin heat sink tested in this study showed better cooling performance compared to that of other plate fin type

  3. Enhancement of the forced convective heat transfer on mini pin fin heat sinks with micro spiral fins

    Science.gov (United States)

    Khonsue, Osot

    2018-02-01

    This research is an experimental study on the characteristics of heat transfer and pressure drop in mini heat sinks using air as the working fluid. The experiments were performed under a constant heat flux ranging from 9.132-13.698 kW/m2 and the air Reynolds number range 322-1982. Three different types of mini heat sinks were rectangle pin fins, cylindrical pin fins, and spiral pin fins with 36x28x9 mm and 5 mm fins high. There were 63 fins altogether and all were made of aluminum. The results showed that the characteristics of the temperature of heat sink of spiral pin fins was the least. Meanwhile the average heat transfer coefficient and Nusselt number of spiral pin fins were the most . Regarding the pressure drop, the rectangular pin fins was the least. The results of this study can be used to guide the design and development of electronic devices cooling system with forced convective heat transfer for higher performance in the future.

  4. FinTech Market Development Perspectives

    Directory of Open Access Journals (Sweden)

    Kalmykova Ekaterina

    2016-01-01

    Full Text Available 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 devices, and get information about expenses and incomes according to the card anywhere in the world. Users do not need to go to banks anymore and to spend their time for credit arrangements, currency exchange, to look for ATMs to remove cash. Purchases on the Internet can be paid not only in rubles, but also in new digital currency. These tools make life easier, however, they pose a serious threat for banks. Now, bank institutions should create more convenient and utility services for the clients to keep clients. Therefore, bank and credit systems start to change actively.

  5. 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.

  6. 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

  7. Epilepsy and restless legs syndrome.

    Science.gov (United States)

    Geyer, James D; Geyer, Emery E; Fetterman, Zachary; Carney, Paul R

    2017-03-01

    Restless legs syndrome (RLS) is a common neurological movement disorder occurring in approximately 10% of the general population. The prevalence of moderately severe RLS is 2.7% overall (3.7% for women and 1.7% for men). Epilepsy is also a common neurological disorder with significant associated morbidity and impact on quality of life. We evaluated the severity and frequency of primary RLS in patients with localization-related temporal lobe epilepsy (TLE) and investigated the role of prodromal RLS symptoms as a warning sign and lateralizing indicator. All epilepsy patients seen in the outpatient clinic were screened for movement disorders from 2005 to 2015. Ninety-eight consecutive patients with localization-related TLE (50 right TLE and 48 left TLE) who met inclusion criteria were seen in the outpatient clinic. The control group consisted of 50 individuals with no history or immediate family history of epilepsy. Each patient was evaluated with the International Restless Legs Study Group (IRLSSG) questionnaire, NIH RLS diagnostic criteria, ferritin level, and comprehensive sleep screening including polysomnography. Furthermore, patients with obstructive sleep apnea or a definite cause of secondary restless legs syndrome such as low serum ferritin or serum iron levels were also excluded from the study. There was a significant association between the type of epilepsy and whether or not patients had RLS χ 2 (1)=10.17, prestlessness was typically described as moderately severe. The RLS symptoms were more common and somewhat more severe in the right TLE group than the left TLE group. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Quinine for Nocturnal Leg Cramps

    Science.gov (United States)

    Man-Son-Hing, Malcolm; Wells, George; Lau, Anita

    1998-01-01

    OBJECTIVE With respect to the use of quinine for the treatment of nocturnal leg cramps, to determine whether the findings of a previously performed meta-analysis of published data are altered with the addition of unpublished data, and whether publication bias is present in this area. DESIGN A meta-analysis of eight (four published and four unpublished) randomized, double-blind, placebo-controlled trials, seven of which had a crossover design. SETTING Randomized trials that were available as of July 1997. SUBJECTS Ambulatory patients (659) who suffered from regular nocturnal leg cramps. MAIN RESULTS When individual patient data from all crossover studies were pooled, persons had 3.60 (95% confidence interval [CI] 2.15, 5.05) fewer cramps in a 4-week period when taking quinine compared with placebo. This compared with an estimate of 8.83 fewer cramps (95% CI 4.16, 13.49) from pooling published studies alone. The corresponding relative risk reductions were 21% (95% CI 12%, 30%) and 43% (95% CI 21%, 65%), respectively. Compared with placebo, the use of quinine was associated with an increased incidence of side effects, particularly tinnitus. Publication bias is present in the reporting of the efficacy of quinine for this indication, as almost all published studies reported larger estimates of its efficacy than did unpublished studies. CONCLUSIONS This study confirms that quinine is efficacious in the prevention of nocturnal leg cramps. However, its benefit may not be as large as reported from the pooling of published studies alone. Given the side effect profile of quinine, nonpharmacologic therapy (e.g., regular passive stretching of the affected muscle) is the best first-line treatment. For persons who find this ineffective and whose quality of life is significantly affected, a trial of quinine is warranted. Prescribing physicians must closely monitor the risks and benefits in individual patients. Publication bias is present in this area even though there is

  9. 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.

  10. 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.

  11. Air cooling effect of fins on a Honda shine bike

    OpenAIRE

    Padhiyar Abhesinh J; Vasim G Machhar

    2015-01-01

    The main of aim of this work is to study various researches done in past to improve heat transfer rate of cooling fins by changing cylinder block fin geometry. Low rate of heat transfer through cooling fins is the main problem in this type of cooling. So efficiency of the engine is increase by increase the heat transfer. Examples of direct air cooling in modern automobiles are rare. The most common example is the commercials Automobile bike like a Honda Shine, Bajaj bike, Honda sp...

  12. Leg fluid accumulation during prolonged sitting.

    Science.gov (United States)

    Vena, Daniel; Rubianto, Jonathan; Popovic, Milos; Yadollahi, Azadeh

    2016-08-01

    The accumulation of fluid in the legs due to sedentariness can be a health risk in extreme cases. Negative health impacts associated with leg fluid accumulation include leg edema and risk of blood clots. Furthermore, fluid accumulating in the legs is accompanied by fluid shift into the upper body which is also associated with health risks such as: increased blood pressure when lying down, respiratory problems in people with heart failure, and increased sleep apnea. Understanding the pattern by which fluid accumulates in the legs can aid in the development of devices for reducing leg fluid accumulation. The purpose of this study was to characterize the time course of fluid accumulation over a two-and-half-hour seated period. Non-obese participants with sleep apnea and no other co-morbidities were included in the sample as part of a larger study. Leg fluid was measured continuously using a method of bioelectrical impedance. Participants were first asked to lie supine for 30 minutes as a washout, and then sat with their legs still for two and a half hours. The main finding of this study is that the pattern of leg fluid accumulation differed in the first 45 minutes compared to the latter 105 minutes. In the first 45 minutes, fluid accumulated according to first order exponential function. In the latter period, fluid accumulated according to a linear function. The initial exponential accumulation is likely due to the large increase in capillary pressure caused by rapid blood flow into the legs due to gravity, leading to substantial filtration of blood plasma into the tissue spaces. The latter linear portion likely represents continued slow filtration of fluid out of the vasculature and into the tissue spaces. This is the first study to show that fluid accumulation in the legs is a combination of an exponential and linear functions. The linear increase identifies that there is no foreseeable point in which leg fluid stops accumulating while sitting for prolonged periods.

  13. El proteccionismo de fin de siglo

    Directory of Open Access Journals (Sweden)

    Marcela SABATÉ SORT

    2010-02-01

    Full Text Available RESUMEN: Dentro del análisis de la política comercial de la Europa continental, este trabajo profundiza en la reacción proteccionista que, contrastando con la apertura anterior, caracteriza el final del siglo XIX y los primeros años del XX, justo hasta el comienzo de la Gran Guerra. Para ello indaga en los factores, especialmente las consecuencias de la "Gran Depresión", que provocan este cambio, en las políticas comerciales de los principales países europeos ante la crisis y en los niveles de protección establecidos. Unas reflexiones finales sobre el común movimiento de elevación arancelaria que preside la evolución de las políticas comerciales del continente en esta etapa y el diverso grado de protección decidido, permiten definir con exactitud la reacción proteccionista realmente acometida. Palabras Clave. Política comercial, Proteccionismo, Crisis económica, Estado, Fin de siglo. ABSTRACT: Within the analysis of the commercial policy of continental Europe, this study delves deeper into the protectionist reaction which, in contrast with the former openness, characterised the end of the nineteenth century and the beginning of the twentieth, right up until he beginning of the Great War. It inquires into the factors that provoked this change, especially the consequences of the Great Depression, and into the commercial policies of the main European countries in the face of this crisis, as well as the levels of protection established. Some final reflections on the common movement to raise tariffs which presided the evolution of the continent's commercial policies during this stage and the diverse degree of protection decided on make it possible to precisely define the protectionist action really undertaken. Key Words: Commercial Policy, Protectionism, Economic Crisis, State, Turn of the Century.

  14. Running with a load increases leg stiffness.

    Science.gov (United States)

    Silder, Amy; Besier, Thor; Delp, Scott L

    2015-04-13

    Spring-mass models have been used to characterize running mechanics and leg stiffness in a variety of conditions, yet it remains unknown how running while carrying a load affects running mechanics and leg stiffness. The purpose of this study was to test the hypothesis that running with a load increases leg stiffness. Twenty-seven subjects ran at a constant speed on a force-measuring treadmill while carrying no load, and while wearing weight vests loaded with 10%, 20%, and 30% of body weight. We measured lower extremity motion and created a scaled musculoskeletal model of each subject, which we used to estimate lower extremity joint angles and leg length. We estimated dimensionless leg stiffness as the ratio of the peak vertical ground reaction force (normalized to body weight) and the change in stance phase leg length (normalized to leg length at initial foot contact). Leg length was calculated as the distance from the center of the pelvis to the center-of-pressure under the foot. We found that dimensionless leg stiffness increased when running with load (p=0.001); this resulted from an increase in the peak vertical ground reaction force (pleg length (p=0.025). When running with load, subjects had longer ground contact times (pleg stiffness to accommodate an added load. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Restless legs syndrome and periodic leg movements in patients with movement disorders: Specific considerations.

    Science.gov (United States)

    Högl, Birgit; Stefani, Ambra

    2017-05-01

    Restless legs syndrome is a frequent neurological disorder with potentially serious and highly distressing treatment complications. The role and potential implications of periodic leg movements during sleep range from being a genetic risk marker for restless legs syndrome to being a cardiovascular risk factor. The diagnosis of restless legs syndrome in patients with daytime movement disorders is challenging and restless legs syndrome needs to be differentiated from other sleep-related movement disorders. This article provides an update on the diagnosis of restless legs syndrome as an independent disorder and the role of periodic leg movements and reviews the association of restless legs syndrome with Parkinson's disease and other movement disorders. © 2017 International Parkinson and Movement Disorder Society. © 2017 International Parkinson and Movement Disorder Society.

  16. 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

  17. 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.

  18. Numerical Study on Hydrodynamic Performance of Bionic Caudal Fin

    OpenAIRE

    Kai Zhou; Junkao Liu; Weishan Chen

    2016-01-01

    In this work, numerical simulations are conducted to reveal the hydrodynamic mechanism of caudal fin propulsion. In the modeling of a bionic caudal fin, a universal kinematics model with three degrees of freedom is adopted and the flexible deformation in the spanwise direction is considered. Navier-Stokes equations are used to solve the unsteady fluid flow and dynamic mesh method is applied to track the locomotion. The force coefficients, torque coefficient, and flow field characteristics are...

  19. 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.

  20. Transcriptional Profiling of Caudal Fin Regeneration in Zebrafish

    Directory of Open Access Journals (Sweden)

    Michael Schebesta

    2006-01-01

    Full Text Available Regeneration of severed limbs in adult animals is restricted to urodele amphibians. Mammals, including humans, have very limited regenerative capabilities and even with proper treatment, only the tips of our digits can grow back. Teleost fish can regenerate amputated fins, the evolutionary ancestors of limbs. To elucidate the principles of limb-fin regeneration, we performed an Affymetrix microarray screen on regenerating caudal fins 12, 24, 48, and 72 h post amputation. Approximately 15,000 zebrafish transcripts were analyzed, identifying 829 transcripts as differentially expressed during regeneration. Of those, 563 were up-regulated and 266 were down-regulated. We constructed a comprehensive database containing expression data, functional assignment, and background information from the literature for each differentially expressed transcript. In order to validate our findings, we employed three approaches: (1 microarray expression analysis of genes previously implicated in fin regeneration, (2 RT-PCR analysis of genes newly identified as differentially expressed during regeneration, and (3 in situ hybridization of the up-regulated genes bambi, dlx5A, and her6. Moreover, we show that Smad 1/5/8 proteins, effector molecules of Bmp signaling, are phosphorylated during fin regeneration. Taken together, we provide a comprehensive database of fin regeneration that will serve as an important tool for understanding the molecular mechanisms of regeneration.

  1. 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)

  2. Thermal stability of germanium-tin (GeSn) fins

    Science.gov (United States)

    Lei, Dian; Lee, Kwang Hong; Bao, Shuyu; Wang, Wei; Masudy-Panah, Saeid; Tan, Chuan Seng; Tok, Eng Soon; Gong, Xiao; Yeo, Yee-Chia

    2017-12-01

    We investigate the thermal stability of germanium-tin (Ge1-xSnx) fins under rapid thermal annealing in N2 ambient. The Ge1-xSnx fins were formed on a GeSn-on-insulator substrate and were found to be less thermally stable than blanket Ge1-xSnx films. The morphology change and material quality of the annealed Ge1-xSnx fin are investigated using scanning electron microscopy, Raman spectroscopy, high-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy, and electron energy loss spectroscopy. Obvious degradation of crystalline quality of the Ge0.96Sn0.04 fin was observed, and a thin Ge layer was formed on the SiO2 surface near the Ge0.96Sn0.04 fin region after 500 °C anneal. A model was proposed to explain the morphology change of the Ge0.96Sn0.04 fin.

  3. Experimental Research and Simulation of Fin and Tube Heat Exchanger

    Directory of Open Access Journals (Sweden)

    Artur Rubcov

    2017-09-01

    Full Text Available The paper provides the results of experimental and theoretical test of a wavy fin and tube heat exchanger used to cool air in a ventilation system when the wavy fin of the heat exchanger is dry and wet. The experimental tests, performed in the range of 1000fins, the thickness of the fin and the diameter of the tube. The experimental tests were performed on 9 heat exchangers in heating and 6 heat exchangers in cooling mode. After processing the results of the experimental tests, empirical equation defining the characteristics of the heat transfer coefficient of all heat exchangers were derived. The maximum heat transfer coefficient deviation is 11.6 percent. The correction factor of the wet fin (Lewis number depending on the number of Reynolds, which ranges from 0.75 to 1.1 also is determined. Maximum capacity deviation equals 3.7 percent. The obtained equations can only be applied to a certain group of heat exchangers (with the same shape of fins or the distance between the tubes. The results of the experimental test and simulation with ANSYS program are compared and the heat transfer coefficients vary from 6.5 to 11.4 percent.

  4. Restless legs syndrome mimicking S1 radiculopathy.

    Science.gov (United States)

    Zambelis, Th; Wolgamuth, B R; Papoutsi, S N; Economou, N T

    2016-01-01

    Α case of a chronic idiopathic form of a severe type of Restless Legs Syndrome (RLS), which developed during pregnancy and persisted after this, misdiagnosed for 34 years as radiculopathy S1, is reported. In spite of the thorough clinical and laboratory investigation, in addition to constant changes of the therapeutic approach, the diagnosis of S1 radiculopathy could not be confirmed, resulting in a chronic clinical course; the latter was characterized by relapses and remissions not attributed or linked in any way to the treatment (various types of). In fact, it was due to a routine workup in a sleep clinic, where the patient was referred because of a coincident chronic insomnia (Restless Legs Syndrome is a known and important cause of insomnia/chronic insomnia), which resulted in a proper diagnosis and treatment of this case. With the use of Restless Legs Syndrome appropriate treatment (Pramipexole 0.18 mg taken at bedtime, a dopaminergic agent and Level A recommended drug for Restless Legs Syndrome) an excellent response and immediate elimination of symptoms was achieved. Restless Legs Syndrome may present with a variety of symptoms (with the most prominent shortly being reported with the acronym URGE: Urge to move the legs usually associated with unpleasant leg sensations, Rest induces symptoms, Getting active brings relief, Evening and night deteriorate symptoms); given the fact that Restless Legs Syndrome presents with a great variety and heterogeneity of symptoms (mostly pain, dysesthesia and paresthesia), which may occur in several other diseases (the so called "RLS mimics"), proper diagnosis of Restless Legs Syndrome usually fails. Restless Legs Syndrome misinterpreted as S1 radiculopathy, to the best of our knowledge, has not been reported yet in the literature. Here, case history, clinical course and common RLS mimics are presented. Different forms of Restless Legs Syndrome manifestations, which are commonly -as in this case- misinterpreted due to their

  5. Fins effectiveness and efficiency with position function of rhombus sectional area in unsteady condition

    Science.gov (United States)

    Nugroho, Tito Dwi; Purwadi, P. K.

    2017-01-01

    The function of the fin is to extend surfaces so that objects fitted with fin can remove the heat to the surrounding environment so that the cooling process can take place more quickly. The purpose of this study is to calculate and determine the effect of (a) the convective heat transfer coefficient of fluid on the value of the fin on the efficiency and effectiveness of non-steady state, and (b) the fin material to the value of the fins on the efficiency and effectiveness of non-steady state. The studied fins are in the form of straight fins with rhombus sectional area which is a function of position x with the short diagonal length of D1 and D2 as long diagonal length, L as fin's length and α as fin's tilt angle. Research solved numerical computation, using a finite difference method on the explicit way. At first, the fin has the same initial temperature with essentially temperature Ti = Tb, then abruptly fin conditioned on fluid temperature environment T∞. Fin's material is assumed with uniform properties, does not change with changes in temperature, and fin does not change the shape and volume during the process. The temperature of the fluid around the fins and the value of the convective heat transfer coefficient are permanently constant, and there is no energy generation in the fin. Fin's heat transfer conduction only take place in one direction, namely in the direction perpendicular to the fin base (or x-direction). The entire surface of the fin makes the process of heat transfer to a fluid environment around the fins. The results show that (a) the greater the value of heat transfer coefficient of convection h, the smaller the efficiency fin and effectiveness fins (b) In circumstances of unsteady state, the efficiency and effectivity influenced by the value of density, specific heat, heat transfer coefficient of conduction and thermal diffusivity fin material.

  6. 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

    ,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......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...

  7. Intensive treatment of leg lymphedema

    Directory of Open Access Journals (Sweden)

    Pereira de Godoy Jose

    2010-01-01

    Full Text Available Background: Despite of all the problems caused by lymphedema, this disease continues to affect millions of people worldwide. Thus, the identification of the most efficacious forms of treatment is necessary. Aim: The aim of this study was to evaluate a novel intensive outpatient treatment for leg lymphedema. Methods: Twenty-three legs of 19 patients were evaluated in a prospective randomized study. The inclusion criteria were patients with Grade II and III lymphedema, where the difference, measured by volumetry, between the affected limb below the knee and the healthy limb was greater than 1.5 kg. Intensive treatment was carried out for 6- to 8-h sessions in the outpatient clinic. Analysis of variance was utilized for statistical analysis with an alpha error of 5% (P-value < 0.05 being considered significant. Results: All limbs had significant reductions in size with the final mean loss being 81.1% of the volume of edema. The greatest losses occurred in the first week (P-value < 0.001. Losses of more than 90% of the lymphedema occurred in 9 (39.13% patients; losses of more than 80% in 13 (56.52%, losses of more than 70% in 17 (73.91% and losses of more than 50% were recorded for 95.65% of the patients; only 1 patient lost less than 50% (37.9% of the edema. Conclusion: The intensive treatment of lymphedema in the outpatient clinic can produce significant reductions in the volume of edema over a short period of time and can be recommended for any grade of lymphedema, in particular the more advanced degrees.

  8. Leg blood flow during static exercise.

    Science.gov (United States)

    Kilbom, A; Persson, J

    1982-01-01

    Leg blood flow was studied with the constant infusion dye technique during static exercise of the thigh muscles (quadriceps) and during hand-grips at 15 and 25-30% of MVC. Blood flow and oxygen uptake in the leg increased in quadriceps exercise and reached their highest values (around 1.21/min and 165 ml/min respectively) at 25-30% of MVC, whereas leg vascular resistance decreased. Regional circulatory adaptations and the oxygen uptake - leg blood flow relationship were in close agreement with the responses found in dynamic leg exercise. In view of the marked rise in intramuscular pressure previously observed during quadriceps contractions, a restriction of blood flow and an increased vascular resistance had been expected. Involuntary activation of leg muscles other than the quadriceps may explain the finding. Contractions of the contralateral quadriceps induced a slight increase in leg blood flow, whereas hand-grips had no influence on blood flow or vascular resistance in the leg. The distribution of the cardiac output during static contractions is discussed, and it is concluded that during hand-grips the increase in blood flow is predominantly distributed to the upper part of the body.

  9. Børns leg og eksperimenterende virksomhed

    DEFF Research Database (Denmark)

    Damgaard Warrer, Sarah; Broström, Stig

    Børns leg og eksperimenterende virksomhed er et rigt felt med mange perspektiver, indgangsvinkler og nuancer. I denne bog kædes leg og det eksperimenterende og skabende sammen som to gensidigt forbundne fænomener og belyses i pædagogisk og didaktisk perspektiv. Desuden beskrives potentialet i båd...

  10. Active and Inactive Leg Hemodynamics during Sequential Single-Leg Interval Cycling.

    Science.gov (United States)

    Gordon, Nicole; Abbiss, Chris R; Ihsan, Mohammed; Maiorana, Andrew J; Peiffer, Jeremiah J

    2018-01-11

    Leg order during sequential single-leg cycling (i.e. exercising both legs independently within a single session) may affect local muscular responses potentially influencing adaptations. This study examined the cardiovascular and skeletal muscle hemodynamic responses during double-leg and sequential single-leg cycling. Ten young healthy adults (28 ± 6 y) completed six 1-min double-leg intervals interspersed with one minute of passive recovery and, on a separate occasion, 12 (six with one leg followed by six with the other leg) 1-min single-leg intervals interspersed with one minute of passive recovery. Oxygen consumption, heart rate, blood pressure, muscle oxygenation, muscle blood volume and power output were measured throughout each session. Oxygen consumption, heart rate and power output were not different between sets of single-leg intervals but the average of both sets was lower than the double-leg intervals. Mean arterial pressure was higher during double-leg compared with sequential single-leg intervals (115 ± 9 mmHg vs. 104 ± 9 mmHg; p<0.05) and higher during the initial compared with second set of single-leg intervals (108 ± 10 mmHg vs. 101 ± 10 mmHg; p<0.05). The increase in muscle blood volume from baseline was similar between the active single-leg and double-leg (267 ± 150 μM[BULLET OPERATOR]cm vs. 214 ± 169 μM[BULLET OPERATOR]cm; p=0.26). The pattern of change in muscle blood volume from the initial to second set of intervals was significantly different (p<0.05) when the leg was active in the initial (-52.3 ± 111.6%) compared with second set (65.1 ± 152.9%). These data indicate that the order in which each leg performs sequential single-leg cycling influences the local hemodynamic responses, with the inactive muscle influencing the stimulus experienced by the contralateral leg.

  11. 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

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

    NARCIS (Netherlands)

    Li, G.; Müller, U.K.; Leeuwen, van J.L.; Liu, Hao

    2016-01-01

    Larvae of bony fish swim in the intermediate Reynolds number (Re) regime,
    using body- and caudal-fin undulation to propel themselves. They share a
    median fin fold that transforms into separate median fins as they grow into
    juveniles. The fin fold was suggested to be an adaption for

  13. Effect of leg length on ROM, VJ and leg dexterity in dance.

    Science.gov (United States)

    Wyon, M A; Nevill, A M; Dekker, K; Brown, D D; Clarke, F; Pelly, J; Koutedakis, Y

    2010-09-01

    We investigated the associations between leg length and specific ballet movements in different skill groups. Volunteers were from an undergraduate dance programme (n=18), a pre-professional school (n=43) and from an elite classical ballet company (n=45). Individual data were collected for anthropometry, vertical jump, leg dexterity, and leg active and passive ROM. ANCOVA identified both main effects as significant with regard to vertical jump (gender Peffects with gender, skill or leg length. Active and passive range of motion noted gender (P=0.001) and skill (Peffects of leg length on fundamental ballet skills. The longer legs that benefit vertical jump have a negative influence on range of motion and leg dexterity except for highly skilled dancers, who through skill, seem to have overcome the effects of some of these dichotomies. Georg Thieme Verlag KG Stuttgart . New York.

  14. 3D modeling of dual-gate FinFET

    Science.gov (United States)

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

    2012-11-01

    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 V g1 > V g2. It is shown that the dual-gate FinFET carries higher transconductance than the single-gate device.

  15. 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.

  16. Simple correlation equations for optimum design of annular fins with uniform thickness

    International Nuclear Information System (INIS)

    Arslanturk, Cihat

    2005-01-01

    Simple correlation equations for optimum design of annular fins with uniform cross section are obtained in the present work. The fin volume is fixed to obtain the dimensionless geometrical parameters of the fin with maximum heat transfer rates. The optimum radii ratio of an annular fin which maximizes the heat transfer rate has been found as a function of Biot number and the fin volume. The data from the present solutions is correlated for a suitable range of Biot number and the fin volume. The simple correlation equations presented in this work can assist for thermal design engineers for optimum design of annular fins of uniform thickness

  17. Experimental and numerical investigation of a louvered fin and elliptical tube compact heat exchanger

    Directory of Open Access Journals (Sweden)

    Pooranachandran Karthik

    2015-01-01

    Full Text Available In the present work, an experimental investigation is carried out to analyze the heat transfer characteristics of a louvered fin and elliptical tube compact heat exchanger used as a radiator in an internal combustion engine. Experiments are conducted by positioning the radiator in an open-loop wind tunnel. A total of 24 sets of air, water flow rate combinations are tested, and the temperature drops of air and water were acquired. A numerical analysis has been carried out using Fluent software (a general purpose computational fluid dynamics simulation tool for three chosen data from the experiments. The numerical air-side temperature drop is compared with those of the experimental values. A good agreement between the experimental and numerical results validates the present computational methodology.

  18. Graphite fiber/copper matrix composites for space power heat pipe fin applications

    International Nuclear Information System (INIS)

    Mcdanels, D.L.; Baker, K.W.; Ellis, D.L.

    1991-01-01

    High specific thermal conductivity (thermal conductivity divided by density) is a major design criterion for minimizing system mass for space power systems. For nuclear source power systems, graphite fiber reinforced copper matrix (Gr/Cu) composites offer good potential as a radiator fin material operating at service temperatures above 500 K. Specific thermal conductivity in the longitudinal direction is better than beryllium and almost twice that of copper. The high specific thermal conductivity of Gr/Cu offers the potential of reducing radiator mass by as much as 30 percent. Gr/Cu composites also offer the designer a range of available properties for various missions and applications. The properties of Gr/Cu are highly anisotropic. Longitudinal elastic modulus is comparable to beryllium and about three times that of copper. Thermal expansion in the longitudinal direction is near zero, while it exceeds that of copper in the transverse direction. 5 refs

  19. Steerable Hopping Six-Legged Robot

    Science.gov (United States)

    Younse, Paulo; Aghazarian, Hrand

    2010-01-01

    The figure depicts selected aspects of a six-legged robot that moves by hopping and that can be steered in the sense that it can be launched into a hop in a controllable direction. This is a prototype of hopping robots being developed for use in scientific exploration of rough terrain on remote planets that have surface gravitation less than that of Earth. Hopping robots could also be used on Earth, albeit at diminished hopping distances associated with the greater Earth gravitation. The upper end of each leg is connected through two universal joints to an upper and a lower hexagonal frame, such that the tilt of the leg depends on the relative position of the two frames. Two non-back-driveable worm-gear motor drives are used to control the relative position of the two frames along two axes 120 apart, thereby controlling the common tilt of all six legs and thereby, further, controlling the direction of hopping. Each leg includes an upper and a lower aluminum frame segment with a joint between them. A fiberglass spring, connected via hinges to both segments, is used to store hopping energy prior to launch into a hop and to cushion the landing at the end of the hop. A cable for loading the spring is run into each leg through the center of the universal joints and then down along the center lines of the segments to the lower end of the leg. A central spool actuated by a motor with a harmonic drive and an electromagnetic clutch winds in all six cables to compress all six springs (thereby also flexing all six legs) simultaneously. To ensure that all the legs push off and land in the same direction, timing- belt pulley drives are attached to the leg segments, restricting the flexing and extension of all six legs to a common linear motion. In preparation for a hop, the spool can be driven to load the spring legs by an amount corresponding to a desired hop distance within range. The amount of compression can be computed from the reading of a shaft-angle encoder that

  20. Microdose acquisition in adolescent leg length discrepancy using a low-dose biplane imaging system

    DEFF Research Database (Denmark)

    Jensen, Janni; Mussmann, Bo Redder; Hjarbæk, John

    2017-01-01

    Background Children with leg length discrepancy often undergo repeat imaging. Therefore, every effort to reduce radiation dose is important. Using low dose preview images and noise reduction software rather than diagnostic images for length measurements might contribute to reducing dose. Purpose ...

  1. The performance of radiation cooler for an oscillating fluid flow

    International Nuclear Information System (INIS)

    Huang, Hulin; Zhu, Guiping

    2017-01-01

    In this work, a radiation cooler performance for an oscillating channel fluid flow is investigated numerically utilizing the commercial software FLUENT. Fluid is heated by constant heat flux at the channel heating end and cooled at cooling end, which through heat pipes transferring fluid heat flux to the radiation cooler. Then, the cooled fluid inversely flows to the heating end periodically. The dynamic grid technology is applied to simulate the oscillating fluid flow and heat transfer in the cooler channel. The temperature distribution and cooling efficiency are investigated for the influence of various emissivity ε f , radiation fin width h and fin length H. The results show that the total radiation surface and cooling efficiency of cooler increase linearly with the rising surface emissivity ε f . Heat flux per unit mass of the radiation surface Q out /M decreases initially with the increase of radiation fin length H and then tends to be a constant, while increases logarithmically with the increment of radiation fin width h. From the first heat pipe R1 to last one of the flow channel, temperature of radiation surface decreases with 'corrugated' distribution pattern. Temperature difference of the radiation surface is less than 4 K. - Highlights: • A radiation cooler performance for cooling an oscillating fluid was carried out. • Temperature of radiation surface decreases with “corrugated” distribution. • The effect of fin length and width on heat flux per unit mass of the radiation surface Qout/M was obtained.

  2. Research on flight stability of non rotating fin arrow shaft

    Science.gov (United States)

    Guo, Yachao; He, Guanglin; Zhang, Jiashuo

    2017-09-01

    To research the influence of the variable density fin arrow shaft warhead on flight stability, three different structures of non rotating fin arrow shaft warhead of the individual small caliber cluster arrow projectile is put forward and designed. The aerodynamic characteristics, static stability reserve and the change of the attack angle in the fin arrow shaft warhead are calculated and analyzed through using the static stability reserve theory and the rigid body trajectory equations. The results show that the static stability reserve of the variable density steel-aluminum composite fin arrow shaft warhead is about 21% ~ 27%, which is obviously higher than 13% ~ 17% of the single density steel material. When the initial velocity is 280 m/s and range is 100 m, the attack angle of the fin arrow shaft warhead of variable density and single density are reduced from ± 5 degree to within ± 1 degree.It is indicated that dynamic stability is guaranteed; however, dynamic stability of the former is better than that of the latter according to the decay rate of the attack angle.

  3. 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

  4. Optimization of Internal Cooling Fins for Metal Hydride Reactors

    Directory of Open Access Journals (Sweden)

    Vamsi Krishna Kukkapalli

    2016-06-01

    Full Text Available Metal hydride alloys are considered as a promising alternative to conventional hydrogen storage cylinders and mechanical hydrogen compressors. Compared to storing in a classic gas tank, metal hydride alloys can store hydrogen at nearly room pressure and use less volume to store the same amount of hydrogen. However, this hydrogen storage method necessitates an effective way to reject the heat released from the exothermic hydriding reaction. In this paper, a finned conductive insert is adopted to improve the heat transfer in the cylindrical reactor. The fins collect the heat that is volumetrically generated in LaNi5 metal hydride alloys and deliver it to the channel located in the center, through which a refrigerant flows. A multiple-physics modeling is performed to analyze the transient heat and mass transfer during the hydrogen absorption process. Fin design is made to identify the optimum shape of the finned insert for the best heat rejection. For the shape optimization, use of a predefined transient heat generation function is proposed. Simulations show that there exists an optimal length for the fin geometry.

  5. Nano-fin based mercury-sensor for environmental surveillance.

    Science.gov (United States)

    Keller, L O; Kallis, K T; Fiedler, H L

    2010-09-01

    This Nano-Fin-Sensor bases on a lithography-independent technology-process, enabling research on Nano-Sensors without cost-intensive technology-equipment. Background for the sensor described within this paper is the high pollution with mercury of the environment and the lack of cheap, easy to use and portable sensors. The lithography-independent process is based on a "deposition and etch-back" technique defining Nano-Fins. Active sensor-material is a gold-layer, deposited on the fin, increasing resistance being exposed to mercury-vapor due to the process of amalgamation. Regeneration is done by heating-up the gold-layer using the poly-silicon fin as resistance-heating-device driving out the adsorbed mercury. To increase the measurement-accuracy, the sensor is made up of four Nano-Fin-Sensors, connected as Wheatstone-bridge. Two sensors have to be passivated by a mercury diffusion barrier, here a silicon-nitride-layer.

  6. Pectoral fin of the megamouth shark: skeletal and muscular systems, skin histology, and functional morphology

    OpenAIRE

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

    2014-01-01

    This is the first known report on the skeletal and muscular systems, and the skin histology, of the pectoral fin of the rare planktivorous megamouth shark Megachasma pelagios. The pectoral fin is characterized by three features: 1) a large number of segments in the radial cartilages; 2) highly elastic pectoral fin skin; and 3) a vertically-rotated hinge joint at the pectoral fin base. These features suggest that the pectoral fin of the megamouth shark is remarkably flexible and mobile, and th...

  7. Structure of supporting elements in the dorsal fin of percid fishes.

    Science.gov (United States)

    Weickhardt, Alexander F; Feilich, Kara L; Lauder, George V

    2017-12-01

    The dorsal fin is one of the most varied swimming structures in Acanthomorpha, the spiny-finned fishes. This fin can be present as a single contiguous structure supported by bony spines and soft lepidotrichia, or it may be divided into an anterior, spiny dorsal fin and a posterior, soft dorsal fin. The freshwater fish family Percidae exhibits especially great variation in dorsal fin spacing, including fishes with separated fins of varying gap length and fishes with contiguous fins. We hypothesized that fishes with separated dorsal fins, especially those with large gaps between fins, would have stiffened fin elements at the leading edge of the soft dorsal fin to resist hydrodynamic loading during locomotion. For 10 percid species, we measured the spacing between dorsal fins and calculated the second moment of area of selected spines and lepidotrichia from museum specimens. There was no significant relationship between the spacing between dorsal fins and the second moment of area of the leading edge of the soft dorsal fin. © 2017 Wiley Periodicals, Inc.

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

    Science.gov (United States)

    Jagnandan, Kevin; Sanford, Christopher P

    2013-12-01

    An elongated dorsal and/or anal ribbon-fin to produce forward and backward propulsion has independently evolved in several groups of fishes. In these fishes, fin ray movements along the fin generate a series of waves that drive propulsion. There are no published data on the use of the dorsal ribbon-fin in the basal freshwater bowfin, Amia calva. In this study, frequency, amplitude, wavelength, and wave speed along the fin were measured in Amia swimming at different speeds (up to 1.0 body length/sec) to understand how the ribbon-fin generates propulsion. These wave properties were analyzed to (1) determine whether regional specialization occurs along the ribbon-fin, and (2) to reveal how the undulatory waves are used to control swimming speed. Wave properties were also compared between swimming with sole use of the ribbon-fin, and swimming with simultaneous use of the ribbon and pectoral fins. Statistical analysis of ribbon-fin kinematics revealed no differences in kinematic patterns along the ribbon-fin, and that forward propulsive speed in Amia is controlled by the frequency of the wave in the ribbon-fin, irrespective of the contribution of the pectoral fin. This study is the first kinematic analysis of the ribbon-fin in a basal fish and the model species for Amiiform locomotion, providing a basis for understanding ribbon-fin locomotion among a broad range of teleosts. © 2013 Wiley Periodicals, Inc.

  9. Hot Leg Piping Materials Issues

    International Nuclear Information System (INIS)

    V. Munne

    2006-01-01

    With Naval Reactors (NR) approval of the Naval Reactors Prime Contractor Team (NRPCT) recommendation to develop a gas cooled reactor directly coupled to a Brayton power conversion system as the space nuclear power plant (SNPP) for Project Prometheus (References a and b) the reactor outlet piping was recognized to require a design that utilizes internal insulation (Reference c). The initial pipe design suggested ceramic fiber blanket as the insulation material based on requirements associated with service temperature capability within the expected range, very low thermal conductivity, and low density. Nevertheless, it was not considered to be well suited for internal insulation use because its very high surface area and proclivity for holding adsorbed gases, especially water, would make outgassing a source of contaminant gases in the He-Xe working fluid. Additionally, ceramic fiber blanket insulating materials become very friable after relatively short service periods at working temperatures and small pieces of fiber could be dislodged and contaminate the system. Consequently, alternative insulation materials were sought that would have comparable thermal properties and density but superior structural integrity and greatly reduced outgassing. This letter provides technical information regarding insulation and materials issues for the Hot Leg Piping preconceptual design developed for the Project Prometheus space nuclear power plant (SNPP)

  10. Development and evolution of the muscles of the pelvic fin.

    Directory of Open Access Journals (Sweden)

    Nicholas J Cole

    2011-10-01

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

  11. 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.

  12. Application of fin system to reduce pitch motion

    Directory of Open Access Journals (Sweden)

    B. Rajesh Reguram

    2016-07-01

    Full Text Available Container ships are prone to move at a greater speed compared to other merchant ships. The slenderness of the hull of container vessel is for better speed, but it leads to unfavorable motions. The pitch and roll are related and sometimes the vessel might be forced to parametric roll condition which is very dangerous. A fin attached to the ship hull proves to be more efficient in controlling the pitch. The fin is fitted at a lowest possible location of the hull surface and it is at the bow part of the ship. Simulations are done using proven software package ANSYS AQWA and the results are compared. Simulations are done for both regular and irregular seas and the effect of fin on ship motion is studied. P-M spectrum is considered for various sea states.

  13. 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

  14. 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)

  15. 3D modeling of dual-gate FinFET

    OpenAIRE

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

    2012-01-01

    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...

  16. Bio-inspired propulsor using internally powered flexible fins

    Science.gov (United States)

    Yeh, Peter; Erturk, Alper; Alexeev, Alexander

    2014-11-01

    Using experiments and three dimensional numerical simulations, we study the underwater locomotion of internally powered flexible plates. The flexible plate is composed of Macro-Fiber Composite (MFC) piezoelectric laminates. A sinusoidally varying voltage is applied to the MFCs, causing bending and generating thrust similar to a flapping fin in carangiform motion. In our fully coupled FSI simulations, we model the swimmer as a rectangular elastic plate actuated by a sinusoidal internal moment. The steady state swimming velocity and thrust are measured experimentally and compared to our numerical simulations. Our results can be used to design underwater self-propelling vehicles driven by internally powered flexible fins.

  17. 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...

  18. 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.

  19. Study of transient behavior of finned coil heat exchangers

    Science.gov (United States)

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

    1993-01-01

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

  20. 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 ......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...

  1. Leg pain (Osgood-Schlatter) (image)

    Science.gov (United States)

    Leg pain in older children or young adolescents can occur for many reasons. An Osgood-Schlatter lesion results from continued trauma to the anterior tibial bone and causes a visible lump below the knee.

  2. Support Leg Loading in Punt Kicking

    Science.gov (United States)

    Kermond, John; Konz, Stephen

    1978-01-01

    Maximum distance in football punt kicking is associated with a maximum force transfer to the ball rather than a maximum force transfer through the ground via the support leg. For maximum distance, tred lightly. (Author)

  3. Sturge-Weber syndrome - legs (image)

    Science.gov (United States)

    ... nervous system (neurocutaneous) and is associated with Port Wine Stain, red vascular markings on the face and other parts of the body (shown here on the legs). This is an unusual case, due to the large size of the lesion ( ...

  4. Leg or foot amputation - dressing change

    Science.gov (United States)

    ... patientinstructions/000018.htm Leg or foot amputation - dressing change To use the sharing features on this page, please enable JavaScript. You will need to change the dressing on your limb. This will help ...

  5. Research of heat transfer of staggered horizontal bundles of finned tubes at free air convection

    Science.gov (United States)

    Novozhilova, A. V.; Maryna, Z. G.; Samorodov, A. V.; Lvov, E. A.

    2017-11-01

    The study of free-convective processes is important because of the cooling problem in many machines and systems, where other ways of cooling are impossible or impractical. Natural convective processes are common in the steam turbine air condensers of electric power plants located within the city limits, in dry cooling towers of circulating water systems, in condensers cooled by air and water, in radiators cooling oil of power electric transformers, in emergency cooling systems of nuclear reactors, in solar power, as well as in air-cooling of power semiconductor energy converters. All this makes actual the synthesis of the results of theoretical and experimental research of free convection for heat exchangers with finned tube bundles. The results of the study of free-convection heat transfer for two-, three- and four-row staggered horizontal bundles of industrial bimetallic finned tubes with finning factor of 16.8 and equilateral tubes arrangement are presented. Cross and diagonal steps in the bundles are the same: 58; 61; 64; 70; 76; 86; 100 mm, which corresponds to the relative steps: 1.042; 1.096; 1.152; 1.258; 1.366; 1.545; 1.797. These steps are standardized for air coolers. An equation for calculating the free-convection heat transfer, taking into account the influence of geometrical parameters in the range of Rayleigh number from 30,000 to 350,000 with an average deviation of ± 4.8%, has been obtained. The relationship presented in the article allows designing a wide range of air coolers for various applications, working in the free convection modes.

  6. 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

  7. Conjoined legs: Sirenomelia or caudal regression syndrome?

    OpenAIRE

    Das, Sakti Prasad; Ojha, Niranjan; Ganesh, G Shankar; Mohanty, Ram Narayan

    2013-01-01

    Presence of single umbilical persistent vitelline artery distinguishes sirenomelia from caudal regression syndrome. We report a case of a12-year-old boy who had bilateral umbilical arteries presented with fusion of both legs in the lower one third of leg. Both feet were rudimentary. The right foot had a valgus rocker-bottom deformity. All toes were present but rudimentary. The left foot showed absence of all toes. Physical examination showed left tibia vara. The chest evaluation in sitting re...

  8. Efficiency and Speed in Legged Robots

    Science.gov (United States)

    2011-03-22

    which we substitute into (4.42) : ( -mv s J O=-km+ mvc -k __ c __ V v 2 c c 46 (4.43) (4.44) (4.45) (4.46) to fInd the switching curve m 3 s...Legged Mechanisms. IVSS. Traverse City, MI Muench, P., Alexander, J., Quinn, R., & Aschenbeck, K. (2005) Pneumatic Spring for Legged Walker. SPIE

  9. Flexural characteristics of a stack leg

    International Nuclear Information System (INIS)

    Cook, J.

    1979-06-01

    A 30 MV tandem Van de Graaff accelerator is at present under construction at Daresbury Laboratory. The insulating stack of the machine is of modular construction, each module being 860 mm in length. Each live section stack module contains 8 insulating legs mounted between bulkhead rings. The design, fabrication (from glass discs bonded to stainless steel discs using an epoxy film adhesive) and testing of the stack legs is described. (U.K.)

  10. Experimental Study of Natural Convection Cooling of Vertical Cylinders with Inclined Plate Fins

    Directory of Open Access Journals (Sweden)

    Jong Bum Lee

    2016-05-01

    Full Text Available In this paper, natural convection from vertical cylinders with inclined plate fins is investigated experimentally for use in cooling electronic equipment. Extensive experimental investigations are performed for various inclination angles, fin numbers, and base temperatures. From the experimental data, a correlation for estimating the Nusselt number is proposed. The correlation is applicable when the Rayleigh number, inclination angle, and fin number are in the ranges 100,000–600,000, 30°–90°, and 9–36, respectively. Using the correlation, a contour map depicting the thermal resistance as a function of the fin number and fin thickness is presented. Finally, the optimal thermal resistances of cylinders with inclined plate fins and conventional radial plate fins are compared. It is found that that the optimal thermal resistance of the cylinder with inclined fins is 30% lower than that of the cylinder with radial plate fins.

  11. 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

  12. Three cross leg flaps for lower leg reconstruction of Gustilo type III C open fracture

    Directory of Open Access Journals (Sweden)

    Kazufumi Sano

    2016-01-01

    Full Text Available A 60 year old male had Gustilo type III C open fracture of the right lower leg. After radical debridement, the large open defect including certain loss of the bone tissue was successfully augmented and covered, by consecutive three cross-leg flaps, which consisted of the free rectus abdominis musculocutaneous flap, the fibula osteocutaneous flap and the conventional sural flap. Although indication for amputation or preservation is decided with multiple factors in each case, a strategic combination of cross-leg flap, free flap, external fixation and vascular delay could increase the potential of preservation of the lower leg with even disastrous Gustilo type III C.

  13. Numerical study and optimizing on micro square pin-fin heat sink for electronic cooling

    International Nuclear Information System (INIS)

    Zhao, Jin; Huang, Shanbo; Gong, Liang; Huang, Zhaoqin

    2016-01-01

    Micro pin-fin heat sink, characterized by low thermal resistance, compact structure and uniform temperature distribution along the flow direction, is effective and valuable for thermal management of electronic devices. To enhance the cooling performance of the micro square pin-fin heat sink, a geometry optimizing method changing pin-fin porosity and pin-fin located angle is proposed in this paper. The flow and heat transfer characteristics were studied numerically and the geometry of the micro square pin-fin heat sink was optimized. To reveal the characteristics and advantages of the micro square pin-fin heat sink, the comparison between the square pin-fin and the column pin-fin was made. Numerical results indicate that both the pin-fin porosity and located angle are important for the cooling capacity and thermal performance of the micro square pin-fin heat sink; the optimal porosity and located angle for thermal performance are 0.75 and 30° respectively. Furthermore, micro heat sinks with the optimized square pin-fin present better thermal performance than micro column pin-fin heat sinks, which implies that there is great potential to employ micro square pin-fin heat sinks for thermal management on electronic devices with high energy density. - Highlights: • An optimization method on geometry is proposed for micro square pin-fin heat sink. • Pin-fin porosity and pin-fin located angle are important on thermal performance. • Heat sinks with optimized square pin-fin hold higher cooling capacity than column pin-fin.

  14. Transfer coefficients in elliptical tubes and plate fin heat exchangers

    International Nuclear Information System (INIS)

    Saboya, S.M.

    1979-09-01

    Mean transfer coefficients in elliptical tubes and plate fin heat exchangers were determined by application of heat and mass transfer analogy in conjunction with the naphthalene sublimation technique. The transfer coefficients are presented in a dimensionless form as functions of the Reynolds number. By using the least squares method analytical expressions for the transfer coefficients were determined with low scattering. (E.G.) [pt

  15. 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.

  16. Trophic relationships of the long-finned squid loligo Sanpaulensis ...

    African Journals Online (AJOL)

    The diet and predators of Loligo sanpaulensis (Cephalopoda: Loliginidae) on the southern Brazilian shelf were studied by examining the stomach contents of 668 long-finned squid (12–184 mm mantle length) caught by bottom trawl and the stomach contents of 47 potential predators, including stranded penguins and ...

  17. Los Grammy Latino, su meta inicial y su fin comercial

    OpenAIRE

    Marinés Arroyo Sotomayor

    2015-01-01

    El artículo refiere lo que es este festival musical que premia el talento latino, quienes participan, su meta inicial y su fin comercial. Muestra que a pesar de la tradición de intolerancia del exilio cubano, la música sirvió, una vez más, como puente de cultura

  18. New Design Heaters Using Tubes Finned by Deforming Cutting Method

    Science.gov (United States)

    Zubkov, N. N.; Nikitenko, S. M.; Nikitenko, M. S.

    2017-10-01

    The article describes the results of research aimed at selecting and assigning technological processing parameters for obtaining outer fins of heat-exchange tubes by the deformational cutting method, for use in a new design of industrial water-air heaters. The thermohydraulic results of comparative engineering tests of new and standard design air-heaters are presented.

  19. Transient heat transfer in longitudinal fins of various profiles with ...

    Indian Academy of Sciences (India)

    Abstract. Transient heat transfer through a longitudinal fin of various profiles is studied. The ther- mal conductivity and heat transfer coefficients are assumed to be temperature dependent. The resulting partial differential equation is highly nonlinear. Classical Lie point symmetry methods are employed and some reductions ...

  20. Zebrafish Fins as a Model System for Skeletal Human Studies

    Directory of Open Access Journals (Sweden)

    Manuel Marí-Beffa

    2007-01-01

    Full Text Available Recent studies on the morphogenesis of the fins of Danio rerio (zebrafish during development and regeneration suggest that a number of inductive signals involved in the process are similar to some of those that affect bone and cartilage differentiation in mammals and humans. Akimenko et al. (2002 has shown that bone morphogenetic protein-2b (BMP2b is involved in the induction of dermal bone differentiation during fin regeneration. Many other groups have also shown that molecules from the transforming growth factor-beta superfamily (TGFβ, including BMP2, are effective in promoting chondrogenesis and osteogenesis in vivo in higher vertebrates, including humans. In the present study, we review the state of the art of this topic by a comparative analysis of skeletal tissue development, regeneration and renewal processes in tetrapods, and fin regeneration in fishes. A general conclusion of this study states that lepidotrichia is a special skeletal tissue different to cartilage, bone, enamel, or dentine in fishes, according to its extracellular matrix (ECM composition. However, the empirical analysis of inducing signals of skeletal tissues in fishes and tetrapods suggests that lepidotrichia is different to any responding features with main skeletal tissues. A number of new inductive molecules are arising from fin development and regeneration studies that might establish an empirical basis for further molecular approaches to mammal skeletal tissues differentiation. Despite the tissue dissimilarity, this empirical evidence might finally lead to clinical applications to skeletal disorders in humans.

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

    Science.gov (United States)

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

    2014-10-01

    The maneuverability demonstrated by the weakly electric ghost knifefish (Apteronotus albifrons) is a result of its highly flexible ribbon-like anal fin, which extends nearly three-quarters the length of its body and is composed of approximately 150 individual fin rays. To understand how movement of the anal fin controls locomotion we examined kinematics of the whole fin, as well as selected individual fin rays, during four locomotor behaviors executed by free-swimming ghost knifefish: forward swimming, backward swimming, heave (vertical) motion, and hovering. We used high-speed video (1000 fps) to examine the motion of the entire anal fin and we measured the three-dimensional curvature of four adjacent fin rays in the middle of the fin during each behavior to determine how individual fin rays bend along their length during swimming. Canonical discriminant analysis separated all four behaviors on anal fin kinematic variables and showed that forward and backward swimming behaviors contrasted the most: forward behaviors exhibited a large anterior wavelength and posterior amplitude while during backward locomotion the anal fin exhibited both a large posterior wavelength and anterior amplitude. Heave and hover behaviors were defined by similar kinematic variables; however, for each variable, the mean values for heave motions were generally greater than for hovering. Individual fin rays in the middle of the anal fin curved substantially along their length during swimming, and the magnitude of this curvature was nearly twice the previously measured maximum curvature for ray-finned fish fin rays during locomotion. Fin rays were often curved into the direction of motion, indicating active control of fin ray curvature, and not just passive bending in response to fluid loading. Copyright © 2014 Elsevier GmbH. All rights reserved.

  2. 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

  3. Nusselt Number Correlation for Vertical Tubes with Inverted Triangular Fins under Natural Convection

    Directory of Open Access Journals (Sweden)

    Byeong Dong Kang

    2017-08-01

    Full Text Available Vertical tubes with inverted triangular fins under natural convection are investigated experimentally. The thermal resistances of tubes with inverted triangular fins are measured for various fin numbers, fin heights, and heat inputs. A Nusselt number correlation that best predicts the measured thermal resistances is proposed. The proposed correlation is applicable to the following conditions: Rayleigh numbers of 1000–125,000, fin height to fin length ratios of 0.2–0.6, and fin numbers of 9–72. Finally, a contour map of the thermal resistances calculated from the proposed correlation for various fin thicknesses and fin numbers is presented. The contour map shows that there exist optimal values of the fin thickness and fin number at which the thermal resistance of the inverted-triangular-finned tube is minimized. Therefore, the proposed correlation enables a search for the optimal dimensions and has potential to be used in the designing of inverted-triangular-finned tubes of various cooling devices.

  4. 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

  5. Numerical simulation and experimental research of the integrated high-power LED radiator

    Science.gov (United States)

    Xiang, J. H.; Zhang, C. L.; Gan, Z. J.; Zhou, C.; Chen, C. G.; Chen, S.

    2017-01-01

    The thermal management has become an urgent problem to be solved with the increasing power and the improving integration of the LED (light emitting diode) chip. In order to eliminate the contact resistance of the radiator, this paper presented an integrated high-power LED radiator based on phase-change heat transfer, which realized the seamless connection between the vapor chamber and the cooling fins. The radiator was optimized by combining the numerical simulation and the experimental research. The effects of the chamber diameter and the parameters of fin on the heat dissipation performance were analyzed. The numerical simulation results were compared with the measured values by experiment. The results showed that the fin thickness, the fin number, the fin height and the chamber diameter were the factors which affected the performance of radiator from primary to secondary.

  6. Genetic parameters for claw and leg health, foot and leg conformation, and locomotion in Danish Holsteins

    DEFF Research Database (Denmark)

    Laursen, M. V.; Boelling, D.; Mark, Thomas

    2009-01-01

    The purpose of this study was to estimate the genetic correlations among claw and leg health and potential indicator traits. Claw health was defined as absence of heel horn erosion, interdigital dermatitis, interdigital phlegmon, interdigital hyperplasia, laminitis, and sole ulcer. Leg health...

  7. One-legged endurance training: leg blood flow and oxygen extraction during cycling exercise

    DEFF Research Database (Denmark)

    Rud, B; Foss, O; Krustrup, Peter

    2012-01-01

    Aim: As a consequence of enhanced local vascular conductance, perfusion of muscles increases with exercise intensity to suffice the oxygen demand. However, when maximal oxygen uptake (VO(2) max) and cardiac output are approached, the increase in conductance is blunted. Endurance training increases...... muscle metabolic capacity, but to what extent that affects the regulation of muscle vascular conductance during exercise is unknown. Methods: Seven weeks of one-legged endurance training was carried out by twelve subjects. Pulmonary VO(2) during cycling and one-legged cycling was tested before and after...... training, while VO(2) of the trained leg (TL) and control leg (CL) during cycling was determined after training. Results: VO(2) max for cycling was unaffected by training, although one-legged VO(2) max became 6.7 (2.3)% (mean ± SE) larger with TL than with CL. Also TL citrate synthase activity was higher...

  8. Development of PIMAL: Mathematical Phantom with Moving Arms and Legs

    Energy Technology Data Exchange (ETDEWEB)

    Akkurt, Hatice [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Eckerman, Keith F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2007-05-01

    The computational model of the human anatomy (phantom) has gone through many revisions since its initial development in the 1970s. The computational phantom model currently used by the Nuclear Regulatory Commission (NRC) is based on a model published in 1974. Hence, the phantom model used by the NRC staff was missing some organs (e.g., neck, esophagus) and tissues. Further, locations of some organs were inappropriate (e.g., thyroid).Moreover, all the computational phantoms were assumed to be in the vertical-upright position. However, many occupational radiation exposures occur with the worker in other positions. In the first phase of this work, updates on the computational phantom models were reviewed and a revised phantom model, which includes the updates for the relevant organs and compositions, was identified. This revised model was adopted as the starting point for this development work, and hence a series of radiation transport computations, using the Monte Carlo code MCNP5, was performed. The computational results were compared against values reported by the International Commission on Radiation Protection (ICRP) in Publication 74. For some of the organs (e.g., thyroid), there were discrepancies between the computed values and the results reported in ICRP-74. The reasons behind these discrepancies have been investigated and are discussed in this report.Additionally, sensitivity computations were performed to determine the sensitivity of the organ doses for certain parameters, including composition and cross sections used in the simulations. To assess the dose for more realistic exposure configurations, the phantom model was revised to enable flexible positioning of the arms and legs. Furthermore, to reduce the user time for analyses, a graphical user interface (GUI) was developed. The GUI can be used to visualize the positioning of the arms and legs as desired posture is achieved to generate the input file, invoke the computations, and extract the organ dose

  9. 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.

  10. 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.

  11. 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.

  12. Analysis of the body mass index and leg profiles of Asian women after total leg sculpture.

    Science.gov (United States)

    Tsai, Feng-Chou; Chen, Chien-Hao; Lin, Chan-Yi; Ho, Li-Yung

    2009-08-01

    In addition to the conventional methods used to improve leg contours, total leg sculpture, including liposuction, selective neurectomy, and transilluminated powered phlebectomy, provides a one-time solution of leg contour problems, which is a major aesthetic concern among Asian women. The authors present the postoperative results of total leg sculpture and determine any significance and correlation between the leg variables and body mass index by statistical analysis. Thirty female patients who underwent total leg sculpture between 2005 and 2008 were included in the study, and prospective analysis of the patients' data was performed during a follow-up period of 1 year. Local measurement variables and body mass index were recorded, and the correlation between them was determined by Pearson's correlation and regression analysis. A paired t test was used to compare the postoperative outcomes. Subjectively, all patient results were satisfactory. There were significant differences between preoperative and postoperative measurements for all variables for total leg sculpture. Body mass index was strongly correlated with all leg indexes, and there was a significant positive correlation between the index and variables related to the buttocks and upper thigh. The satisfactory postoperative leg variables were buttocks circumference (87.85 cm), thigh circumference (T60, 44.20 cm), maximal calf circumference (32.24 cm), and calf ratio (0.78). Each preoperative body mass index increment represents a 0.3 percent circumference improvement around the buttocks after surgery. No obvious morbidities or long-term hospital stays were noted. Total leg sculpture provides a combined aesthetic solution for improving limb contours with minimal morbidity. Patients with larger body mass index values exhibit better aesthetic improvement than those with smaller values.

  13. 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...

  14. Efficiency of a fin with convective cooling at variable parameters of heat exchange

    International Nuclear Information System (INIS)

    Kurganov, V.A.

    2003-01-01

    The analysis of the effect of changes in the temperature by the fin length on the efficiency of the fins with the convective cooling and the heat exchange coefficient of the cooling liquid, as well as on the dependence of the fin heat conductivity on the temperature, is carried out through the spline method. It is shown, that by high rates of the λ change the effect of its variability may be essential especially for long fins [ru

  15. 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 ...

  16. Therapeutic advances in restless legs syndrome (RLS).

    Science.gov (United States)

    Högl, Birgit; Comella, Cynthia

    2015-09-15

    Levodopa and dopamine agonists have been the main treatment for restless legs syndrome during the past decades. Although their efficacy has been well documented over the short term, long-term dopaminergic treatment is often complicated by augmentation, loss of efficacy, and other side effects. Recent large randomized controlled trials provide new evidence for the efficacy of high-potency opioids and α2δ ligands, and several post hoc analyses, meta-analyses, algorithms, and guidelines have been published, often with a specific focus, for example, on augmentation, or on management of restless legs syndrome during pregnancy. Several new contributions to understanding the pathophysiology of restless legs syndrome have been published, but at this time, whether they will have an impact on treatment possibilities in the future cannot be estimated. © 2015 International Parkinson and Movement Disorder Society.

  17. Conjoined legs: Sirenomelia or caudal regression syndrome?

    Directory of Open Access Journals (Sweden)

    Sakti Prasad Das

    2013-01-01

    Full Text Available Presence of single umbilical persistent vitelline artery distinguishes sirenomelia from caudal regression syndrome. We report a case of a12-year-old boy who had bilateral umbilical arteries presented with fusion of both legs in the lower one third of leg. Both feet were rudimentary. The right foot had a valgus rocker-bottom deformity. All toes were present but rudimentary. The left foot showed absence of all toes. Physical examination showed left tibia vara. The chest evaluation in sitting revealed pigeon chest and elevated right shoulder. Posterior examination of the trunk showed thoracic scoliosis with convexity to right. The patient was operated and at 1 year followup the boy had two separate legs with a good aesthetic and functional results.

  18. Leg Spasticity and Ambulation in Multiple Sclerosis

    Directory of Open Access Journals (Sweden)

    Swathi Balantrapu

    2014-01-01

    Full Text Available Background. Spasticity of the legs is common in multiple sclerosis (MS, but there has been limited research examining its association with ambulatory outcomes. Objective. This study examined spasticity of the legs and its association with multiple measures of ambulation in persons with MS. Methods. The sample included 84 patients with MS. Spasticity of the legs was measured using a 5-point rating scale ranging between 0 (normal and 4 (contracted. Patients completed the 6-minute walk (6 MW, timed 25 foot walk (T25FW, and timed up-and-go (TUG, and O2 cost of walking was measured during the 6 MW. The patients undertook two walking trials on a GAITRite (CIR systems, Inc. for measuring spatial and temporal parameters of gait. The patients completed the Multiple Sclerosis Walking Scale-12 (MSWS-12 and wore an accelerometer over a seven-day period. Results. 52% (n=44 of the sample presented with spasticity of the legs. Those with leg spasticity had significantly worse ambulation as measured by 6 MW (P=0.0001, d=-0.86, T25FW (P=0.003,d=0.72, TUG (P=0.001, d=0.84, MSWS-12 (P=0.0001,d=1.09, O2 cost of walking (P=0.001, d=0.75, average steps/day (P<0.05, d=-0.45, and walking velocity (P<0.05, d=-0.53 and cadence (P<0.05, d=-0.46. Conclusion. Leg spasticity was associated with impairments in ambulation, including alterations in spatiotemporal parameters and free-living walking.

  19. 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.

  20. 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 ...

  1. Experimental and computational fluid dynamics analysis of a photovoltaic/thermal system with active cooling using aluminum fins

    Science.gov (United States)

    Ömeroǧlu, Gökhan

    2017-10-01

    Being the most widespread renewable energy generation system, photovoltaic (PV) systems face major problems, overheating and low overall conversion efficiency. The electrical efficiency of PV systems is adversely affected by significant increases in cell temperature upon exposure to solar irradiation. There have been several ways to remove excess heat and cool down the PV to maintain efficiency at fair levels. A hybrid photovoltaic/thermal system cooled by forced air circulation blown by a PV-powered fan was set up, and a rectangular control volume with cylindrical ends was built at the back of the PV panel where aluminum fins were placed in different arrangements and numbers. During the experiments, temperature and electrical output parameters were measured for three different air velocities (3.3, 3.9, and 4.5 m/s) and two different fin numbers and arrangements (54 pcs shifted and 108 pcs inline) under a constant radiation value of 1350 W/m2. While the electrical efficiency of the panel was reduced by almost 50% and decreased from 12% to 6.8% without active cooling, at 4.5-m/s air velocity and with 108 fins in inline arrangement, the electrical efficiency could be maintained at 11.5%. To compare and verify the experimental results, a heat transfer simulation model was developed with the ANSYS Fluent, and a good fit between the simulation and the test results was obtained.

  2. The Molecular Genetics of Restless Legs Syndrome.

    Science.gov (United States)

    Rye, David B

    2015-09-01

    Restless legs syndrome (RLS) is a common sensorimotor trait defined by symptoms that interfere with sleep onset and maintenance in a clinically meaningful way. Nonvolitional myoclonus while awake and asleep is a sign of the disorder and an informative endophenotype. The genetic contributions to RLS/periodic leg movements are substantial, are among the most robust defined to date for a common disease, and account for much of the variance in disease expressivity. The disorder is polygenic, as revealed by recent genome-wide association studies. Experimental studies are revealing mechanistic details of how these common variants might influence RLS expressivity. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Nocturnal leg cramps in older people

    Science.gov (United States)

    Butler, J; Mulkerrin, E; O'Keeffe, S

    2002-01-01

    Nocturnal leg cramps are common in older people. Such cramps are associated with many common diseases and medications. Physiological methods may be useful for preventing cramps in some people, but there have been no controlled trials of these approaches. Quinine is moderately effective in preventing nocturnal leg cramps. However, there are concerns about the risk/benefit ratio with this drug. In patients with severe symptoms, a trial of 4–6 weeks' treatment with quinine is probably still justified, but the efficacy of treatment should be monitored, for example using a sleep and cramp diary. PMID:12415081

  4. Symptom Severity of Restless Legs Syndrome Predicts Its Clinical Course.

    Science.gov (United States)

    Lee, Chung Suk; Kim, Tae; Lee, Sumin; Jeon, Hong Jun; Bang, Young Rong; Yoon, In-Young

    2016-04-01

    This study examines the clinical course of restless legs syndrome according to its severity and factors associated with the remission of restless legs syndrome symptoms. The remission or persistence of restless legs syndrome symptoms was investigated by considering patients with restless legs syndrome at the sleep clinic of Seoul National University Bundang Hospital. All subjects were observed for at least 18 months, and an incidence of remission was defined as having no restless legs syndrome symptoms for at least 1 year. Restless legs syndrome severity was evaluated by the International Restless Legs Syndrome Study Group Rating Scale. A total of 306 patients participated in this study. Over the observation periods of 4.1 ± 1.6 years, the cumulative incidence of remission is 32.5% (95% confidence interval [CI], 27.0-38.0) and decreased with baseline restless legs syndrome severity (P restless legs syndrome cases, respectively. Most cases of remission (82/96) were observed within 1 year, and the remission occurred sooner for mild restless legs syndrome. The hazard ratios of remission by Cox proportional hazards model were lower for moderate (0.556; 95% CI, 0.340-0.909) and severe to very severe (0.193; 95% CI, 0.108-0.343) restless legs syndrome than for mild restless legs syndrome. The remission incidence was lower for those patients who had a family history of restless legs syndrome and were older at restless legs syndrome diagnosis. Mild restless legs syndrome severity, no family history, and young age at restless legs syndrome diagnosis were significant predictors of restless legs syndrome remission. More than 80% of patients with severe restless legs syndrome showed a chronic clinical course. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Het fin-de-siècle als vertoning

    Directory of Open Access Journals (Sweden)

    W. Krul

    2002-01-01

    Full Text Available 1900Wessel KrulIn their publication entitled 1900: Hoogtij van burgerlijke cultuur, the authors, Jan Bank and Maarten van Buuren, failed to pay adequate attention to the contrasts and differences that typified Dutch culture at the fin de siècle. The book therefore lacks analytical precision. The term 'bourgeois culture' should not have been applied in such an all-inclusive and unambiguous manner.

  6. THE EFFECTS OF SINGLE LEG HOP PROGRESSION AND DOUBLE LEGS HOP PROGRESSION EXERCISE TO INCREASE SPEED AND EXPLOSIVE POWER OF LEG MUSCLE

    Directory of Open Access Journals (Sweden)

    Nining W. Kusnanik

    2015-05-01

    Full Text Available The main purpose of this study was to determine the effect of single leg hop progression and double legs hop progression exercise to increase speed and explosive power of leg muscles. Plyometric is one of the training methods that can increase explosive power. There are many models of plyometric training including single leg hop progression and double leg hop progression. This research was experimental using match subject design techniques. The subjects of this study were 39 students who joined basketball school club. There were 3 groups in this study: Group 1 were 13 students who given sin¬gle leg hop progression exercise, Group 2 were 13 students who given double legs hop progression exercise, Group 3 were 13 students who given conventional exercise. The data was collected during pre test and post test by testing 30m speed running and vertical jump. The data was analyzed using Analysis of Varians (Anova. It was found that there were significantly increased on speed and explosive power of leg muscles of Group 1 and Group 2. It can be stated that single leg hop progression exercise was more effective than double leg hop progression exercise. The recent findings supported the hypothesis that single leg hop progression and double legs hop progression exercise can increase speed and explosive power of leg muscles. These finding were supported by some previous studies (Singh, et al, 2011; Shallaby, H.K., 2010. The single leg hop progression is more effective than double legs hop progression. This finding was consistent with some previous evidences (McCurdy, et al, 2005; Makaruk et al, 2011.

  7. Clinical characteristics of leg restlessness in Parkinson's disease compared with idiopathic Restless Legs Syndrome.

    Science.gov (United States)

    Zhu, Xiao-Ying; Liu, Ye; Zhang, Xiao-Jin; Yang, Wen-Hao; Feng, Ya; Ondo, William G; Tan, Eng-King; Wu, Yun-Cheng

    2015-10-15

    There is limited data on motor restlessness in Parkinson's disease (PD). Here we evaluate for clinical differences between cohorts of idiopathic Restless Legs Syndrome (iRLS), PD patients with leg restlessness, and PD with RLS. We examined 276 consecutive PD patients for leg restlessness symptoms, we compared clinical features of PD patients with RLS, PD patients with leg restlessness but not meeting RLS criteria, PD patient without RLS and iRLS. A total of 262 PD patients who satisfied the inclusion criteria were analyzed. After excluding 23 possible secondary RLS or mimics, 28 were diagnosed with RLS and 18 with leg motor restlessness (LMR). Compared with iRLS patients, PD patients with RLS or LMR had older age of RLS/LMR onset, shorter duration of leg restlessness, less positive family history, different seasonal trends and more unilaterality of leg restlessness symptom (Pleg restlessness. PD with LMR had less severe Parkinsonism (Pleg restlessness (P<0.01) symptoms than PD with RLS. Clinical characteristics of PD patients with RLS and LMR were different from iRLS, differentiating these various subtypes can facilitate optimal treatment. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Task driven optimal leg trajectories in insect-scale legged microrobots

    Science.gov (United States)

    Doshi, Neel; Goldberg, Benjamin; Jayaram, Kaushik; Wood, Robert

    Origami inspired layered manufacturing techniques and 3D-printing have enabled the development of highly articulated legged robots at the insect-scale, including the 1.43g Harvard Ambulatory MicroRobot (HAMR). Research on these platforms has expanded its focus from manufacturing aspects to include design optimization and control for application-driven tasks. Consequently, the choice of gait selection, body morphology, leg trajectory, foot design, etc. have become areas of active research. HAMR has two controlled degrees-of-freedom per leg, making it an ideal candidate for exploring leg trajectory. We will discuss our work towards optimizing HAMR's leg trajectories for two different tasks: climbing using electroadhesives and level ground running (5-10 BL/s). These tasks demonstrate the ability of single platform to adapt to vastly different locomotive scenarios: quasi-static climbing with controlled ground contact, and dynamic running with un-controlled ground contact. We will utilize trajectory optimization methods informed by existing models and experimental studies to determine leg trajectories for each task. We also plan to discuss how task specifications and choice of objective function have contributed to the shape of these optimal leg trajectories.

  9. Numerical Study on Hydrodynamic Performance of Bionic Caudal Fin

    Directory of Open Access Journals (Sweden)

    Kai Zhou

    2016-01-01

    Full Text Available In this work, numerical simulations are conducted to reveal the hydrodynamic mechanism of caudal fin propulsion. In the modeling of a bionic caudal fin, a universal kinematics model with three degrees of freedom is adopted and the flexible deformation in the spanwise direction is considered. Navier-Stokes equations are used to solve the unsteady fluid flow and dynamic mesh method is applied to track the locomotion. The force coefficients, torque coefficient, and flow field characteristics are extracted and analyzed. Then the thrust efficiency is calculated. In order to verify validity and feasibility of the algorithm, hydrodynamic performance of flapping foil is analyzed. The present results of flapping foil compare well with those in experimental researches. After that, the influences of amplitude of angle of attack, amplitude of heave motion, Strouhal number, and spanwise flexibility are analyzed. The results show that, the performance can be improved by adjusting the motion and flexibility parameters. The spanwise flexibility of caudal fin can increase thrust force with high propulsive efficiency.

  10. 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.

  11. 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...

  12. Non-Destructive Testing Methods Applied to Multi-Finned SAP Tubing for Nuclear-Fuel Elements

    International Nuclear Information System (INIS)

    Lund, S.A.; Knudsen, P.

    1965-01-01

    The Danish Atomic Energy Commission has undertaken a design study oi an organic-cooled, heavy- water-moderated power reactor. The fuel element for the reactor is a 19-rod bundle; the fuel rods contain sintered uranium-dioxide pellets canned in 2-m long, helically-finned tubes of Sintered Aluminium Product (SAP). A very high quality of the canning tubes is necessary to obtain the optimum heat-transfer conditions and to maintain the integrity of the fuel element during reactor service. Two examples of tube design illustrate the narrow dimensional tolerances. In order to ensure an adequate quality of the canning tubes, a stringent quality control has been established, to a wide extent based upon non-destructive methods. An account is presented of the non-destructive techniques developed for measuring wall thickness and diameters and for detecting defects. The complex 24-finned cross-section prevents the application of ultrasonic or eddy-current methods for wall-thickness measurements. Therefore, a special recording beta-gauge has been developed, based upon the attenuation of beta radiation from a Sr 90 source placed inside the tube. An ultrasonic immersion resonance method is used for the continuous recording of the wall thickness of the more simple 12-finned tube design. Inner and outer (across fin tips) diameters are continuously recorded by rapid air-gauge systems. Flaw detection is carried out by the ultrasonic pulse-echo immersion technique and by eddy-current inspection.. Transverse cracks can easily be detected by the ultrasonic method whereas inspection for longitudinal flaws has not appeared feasible with this method. Therefore, eddy-current inspection is applied in addition to the ultrasonic testing. (author) [fr

  13. Radiation effects in advanced multiple gate and silicon-on-insulator transistors

    International Nuclear Information System (INIS)

    Simoen, E.; Gaillardin, M.; Paillet, P.; Reed, R.A.; Schrimpf, R.D.; Alles, M.L.; El-Mamouni, F.; Fleetwood, D.M.; Griffoni, A.; Claeys, C.

    2013-01-01

    The aim of this review paper is to describe in a comprehensive manner the current understanding of the radiation response of state-of-the-art Silicon-on-Insulator (SOI) and FinFET CMOS technologies. Total Ionizing Dose (TID) response, heavy-ion micro-dose effects and single-event effects (SEEs) will be discussed. It is shown that a very high TID tolerance can be achieved by narrow-fin SOI FinFET architectures, while bulk FinFETs may exhibit similar TID response to the planar devices. Due to the vertical nature of FinFETs, a specific heavy-ion response can be obtained, whereby the angle of incidence becomes highly important with respect to the vertical sidewall gates. With respect to SEE, the buried oxide in the SOI FinFETs suppresses the diffusion tails from the charge collection in the substrate compared to the planar bulk FinFET devices. Channel lengths and fin widths are now comparable to, or smaller than the dimensions of the region affected by the single ionizing ions or lasers used in testing. This gives rise to a high degree of sensitivity to individual device parameters and source-drain shunting during ion-beam or laser-beam SEE testing. Simulations are used to illuminate the mechanisms observed in radiation testing and the progress and needs for the numerical modeling/ simulation of the radiation response of advanced SOI and FinFET transistors are highlighted. (authors)

  14. [The influence of the leg load and the support mobility under leg on the anticipatory postural adjustment].

    Science.gov (United States)

    Kazennikov, O V; Kireeva, T B; Shlykov, V Iu

    2015-01-01

    Anticipatory postural adjustment is an essential part of equilibrium maintainance during standing in human. So changes in stance condition could affect both control of equilibrium and anticipatory adjustment. Anticipatory changes in the stabilogram of each leg were studied in standing subject during the early stage of quick right arm lifting while legs were on two separated supports. The center of pressure (CP) movement was analyzed in three variants of experiment: both legs on immovable support, with only right leg on the movable support and with only left leg on the moveable support. In each standing condition subject stood with symmetrical load on two legs or with the load voluntary transferred to one leg. The anticipatory CP shift depended on the mobility of the support under the leg and on loading of the leg. While standing on unmovable supports with symmetrical load on the legs before lifting of the right arm CP of right leg shifted backward and CP of left leg--forward. While standing with one leg on movable support the anticipatory CP shift of this leg was small and did not depend on the load on the leg. However the shift of CP of the leg that was placed on the unmovable support depended on the load in the same way as in the case when both legs were on unmovable supports. Results suggested that since on movable support the support and proprioceptive afferent flow from distal part of the leg that was did not supply unambiguous information about body position, the role of distal joints in posture control is reduced.

  15. Comparative analysis of different cooling fin types for countering LED luminaires' heat problems

    OpenAIRE

    KARATEKİN, CANAN; KÖKKAYA, OYTUN

    2018-01-01

    A significant problem with high-power LED luminaires is heat. Aluminum heat sinks have been extensively used as a solution. The most common method for heat sinks that increases surface area uses fins. In the present study, pin- and plate-fins were compared and it was observed that, in equal surface areas, better cooling was achieved by pin-fins. Thus, the study's concentration narrowed to pin-fins and the results of different pin-fins were compared. Simulations of a sample group were...

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

    Energy Technology Data Exchange (ETDEWEB)

    Oberkampf, W. L.

    1981-04-01

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

  17. An automatic hinge system for leg orthoses

    NARCIS (Netherlands)

    Rietman, J. S.; Goudsmit, J.; Meulemans, D.; Halbertsma, J. P. K.; Geertzen, J. H. B.

    2004-01-01

    This paper describes a new automatic hinge system for leg orthoses, which provides knee stability in stance, and allows knee-flexion during swing. Indications for the hinge system are a paresis or paralysis of the quadriceps muscles. Instrumented gait analysis was performed in three patients, fitted

  18. An automatic hinge system for leg orthoses

    NARCIS (Netherlands)

    Rietman, J.S.; Goudsmit, J.; Meulemans, D.; Halbertsma, J.P.K.; Geertzen, J.H.B.

    This paper describes a new, automatic hinge system for leg orthoses, which provides knee stability in stance, and allows knee-flexion during swing. Indications for the hinge system are a paresis or paralysis of the quadriceps muscles. Instrumented gait analysis was performed in three patients,

  19. Chronic leg ulcer caused by Mycobacterium immunogenum

    NARCIS (Netherlands)

    Loots, Miriam A. M.; de Jong, Menno D.; van Soolingen, Dick; Wetsteyn, José C. F. M.; Faber, William R.

    2005-01-01

    Rare tropical skin diseases are seen more frequently in Western countries because of the increased popularity of visiting tropical regions. A 55-year-old white man developed a painless leg ulcer after traveling in Guatemala and Belize. A mycobacterium was cultured from a biopsy specimen and was

  20. X-Ray Exam: Femur (Upper Leg)

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español X-Ray Exam: Femur (Upper Leg) KidsHealth / For Parents / X- ... Muscles, and Joints Broken Bones Getting an X-ray (Video) X-Ray (Video) View more Partner Message About Us ...

  1. The restless legs syndrome (Ekbom's syndrome)

    African Journals Online (AJOL)

    1983-04-30

    Apr 30, 1983 ... same distribution as the paraesthesiae; and (v) anxiety, tension or mild depression. Paraesthesiae or creeping sensations are usually confined to the calves. They are extremely unpleasant and deep-seated in muscles or bones rather than in the skin, mostly affecting the legs between the knee and ankle.

  2. Leg og læring

    DEFF Research Database (Denmark)

    Pedersen, Annette

    2008-01-01

    Leg synes at have et potentiale som metode til at fremme læring. Men hvordan? Legen har en vis grad af parallelitet med den virkelige verden i dens interaktive og relationelle strukturer. Det bliver muligt at finde nye meninger i interaktioner, som refererer til vante interaktionsformer, men...

  3. Functional scoliosis caused by leg length discrepancy

    Science.gov (United States)

    Daniszewska, Barbara; Zolynski, Krystian

    2010-01-01

    Introduction Leg length discrepancy (LLD) causes pelvic obliquity in the frontal plane and lumbar scoliosis with convexity towards the shorter extremity. Leg length discrepancy is observed in 3-15% of the population. Unequalized lower limb length discrepancy leads to posture deformation, gait asymmetry, low back pain and discopathy. Material and methods In the years 1998-2006, 369 children, aged 5 to 17 years (209 girls, 160 boys) with LLD-related functional scoliosis were treated. An external or internal shoe lift was applied. Results Among 369 children the discrepancy of 0.5 cm was observed in 27, 1 cm in 329, 1.5 cm in 9 and 2 cm in 4 children. During the first follow-up examination, within 2 weeks, the adjustment of the spine to new static conditions was noted and correction of the curve in 316 examined children (83.7%). In 53 children (14.7%) the correction was observed later and was accompanied by slight low back pain. The time needed for real equalization of limbs was 3 to 24 months. The time needed for real equalization of the discrepancy was 11.3 months. Conclusions Leg length discrepancy equalization results in elimination of scoliosis. Leg length discrepancy < 2 cm is a static disorder; that is why measurements should be performed in a standing position using blocks of adequate thickness and the position of the posterior superior iliac spine should be estimated. PMID:22371777

  4. Omnidirectional Wheel-Legged Hybrid Mobile Robot

    Directory of Open Access Journals (Sweden)

    István Vilikó

    2015-06-01

    Full Text Available The purpose of developing hybrid locomotion systems is to merge the advantages and to eliminate the disadvantages of different type of locomotion. The proposed solution combines wheeled and legged locomotion methods. This paper presents the mechatronic design approach and the development stages of the prototype.

  5. Parallel kinematics robot with five legs

    NARCIS (Netherlands)

    Lambert, P.

    2011-01-01

    Robot with multiple degrees of freedom comprising five legs (2) linked at a first of their ends to a base ( 3), and at a second of their ends opposite to the first ends to a mobile platform (4), which platform carries at least one tool (5, 6, 121, 12 "), and wherein the robot further comprises an

  6. An improved model for predicting performance of finned tube heat exchanger under frosting condition, with frost thickness variation along fin

    Energy Technology Data Exchange (ETDEWEB)

    Tso, C.P. [Multimedia University, Jalan Ayer Keroh Lama, Melaka (Malaysia). Faculty of Engineering and Technology; Cheng, Y.C.; Lai, A.C.K. [Nanyang Technological University, Singapore (Singapore). School of Mechanical and Aerospace Engineering

    2006-01-15

    Frost accumulation on a heat exchanger, a direct result of combined heat and mass transfer between the moist air flowing across a cold surface, causes heat transfer performance degradation due to the insulating effect of frost layer and the coil blockage as the frost grows. The complex geometry of finned tube heat exchangers leads to uneven wall and air temperature distribution inside the coil, and causes variations of frost growth rate and densification along the coil. In this study, a general distributed model with frost formation was developed. The equations for finned tube heat exchanger were derived in non-steady-state manner and quasi-steady state in the frost model. In order to make the model more realistic, the variation of frost along fin due to uneven temperature distribution was included. The presented model is able to predict the dynamic behavior of an air cooler both under non-frost and frost condition. Comparisons were made based on the frost mass accumulation, pressure drop across coil and energy transfer coefficient, and results were found to agree well with reported experimental results. (author)

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

    Science.gov (United States)

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

    2010-07-20

    The use of swim fins has become popular in various water sport activities. While numerous models of swim fin with various innovative shapes have been subjectively designed, the exact influence of the fin characteristics on swimming performance is still much debated, and remains difficult to quantify. To date, the most common approach for evaluating swim fin propulsion is based on the study of "swimmer-fins" as a global system, where physiological and/or biomechanical responses are considered. However, reproducible swimming technique is difficult (or even impossible) to obtain on human body and may lead to discrepancies in data acquired between trials. In this study, we present and validate a new automat called HERMES which enables an evaluation of various swim fins during an adjustable, standardized and reproducible motion. This test bench reliably and accurately reproduces human fin-swimming motions, and gives resulting dynamic measurements at the ankle joint. Seven fins with various geometrical and mechanical characteristics were tested. For each swim fin, ankle force and hydromechanical efficiency (useful mechanical power output divided by mechanical power input delivered by the motors) were calculated. Efficiencies reported in our study were high (close to 70% for some swim fins) over a narrow range of Strouhal number (St) and peaks within the interval 0.2swimming animals. Therefore, an interesting prospect in this work would be to accurately study the impact of adjustable fin kinematics and material (design and mechanical properties) on the wake structure and on efficiency. 2010 Elsevier Ltd. All rights reserved.

  8. 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

  9. Pectoral fin of the megamouth shark: skeletal and muscular systems, skin histology, and functional morphology.

    Directory of Open Access Journals (Sweden)

    Taketeru Tomita

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

  10. Pectoral fin of the megamouth shark: skeletal and muscular systems, skin histology, and functional morphology.

    Science.gov (United States)

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

    2014-01-01

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

  11. 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.

  12. Design optimization of pin fin geometry using particle swarm optimization algorithm.

    Directory of Open Access Journals (Sweden)

    Nawaf Hamadneh

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

  13. 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.

  14. Muscle activity and hydrodynamic function of pelvic fins in trout (Oncorhynchus mykiss).

    Science.gov (United States)

    Standen, E M

    2010-03-01

    Contrary to the previous premise that pelvic fins lacked obvious function, recent work on three-dimensional fin motions suggests that pelvic fins actively control stability and speed in slowly swimming trout. This study used electromyography to measure pelvic fin muscle activity and particle imaging velocimetry to quantify flow along the ventral body region to test this hypothesis. Fish swam at slow speeds (0.13-1.36 BL s(-1)) while being filmed with three high speed cameras. Three-dimensional kinematics were captured for all trials. During EMG trials pelvic fin muscle activity was synchronized to kinematic motion, during particle imaging velocimetry trials, a laser light-sheet was used to visualize the flow surrounding the ventral aspect of the fish. Four main conclusions are reached: first, pelvic fins are actively oscillated during slow-speed swimming; antagonistic abductor and adductor muscles contracted simultaneously, their collective action producing a unique contralateral oscillating behaviour in the fins. Second, pelvic fins slow the flow along the ventral side affecting pitch and yaw instabilities; flow upstream of the pelvic fins is slowed by 0.02 m s(-1) and flow downstream of the pelvic fins is slowed by 0.034 m s(-1) compared with free stream flow. Third, pelvic fin wake influences anal fin angle of attack; flow angle in the wake of the pelvic fin was 33.84+/-2.4 deg. (max) and -11.83+/-11.2 deg. (min) compared with the free stream flow angle of 1.27+/-0.1 deg. Fourth, pelvic fins appear to actively damp body oscillation during slow-speed swimming, providing drag to help control speed and stabilize the body position during slow-speed swimming.

  15. 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

  16. Interventions for leg cramps in pregnancy.

    Science.gov (United States)

    Zhou, Kunyan; West, Helen M; Zhang, Jing; Xu, Liangzhi; Li, Wenjuan

    2015-08-11

    Leg cramps are a common problem in pregnancy. Various interventions have been used to treat them, including drug, electrolyte and vitamin therapies, and non-drug therapies. To assess the effectiveness and safety of different interventions for treating leg cramps in pregnancy. We searched the Cochrane Pregnancy and Childbirth Group's Register (31 March 2015) and reference lists of retrieved studies. Randomised controlled trials (RCTs) of any intervention (drug, electrolyte, vitamin or non-drug therapies) for treatment of leg cramps in pregnancy compared with placebo, no treatment or other treatment. Quinine was excluded for its known adverse effects (teratogenicity). Cluster-RCTS were considered for inclusion. Quasi-RCTs and cross-over studies were excluded. Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. We included six studies (390 women). Four trials compared oral magnesium with placebo/no treatment, two compared oral calcium with no treatment, one compared oral vitamin B versus no treatment, and one compared oral calcium with oral vitamin C. Two of the trials were well-conducted and reported, the other four had design limitations. The process of random allocation was sub-optimal in three studies, and blinding was not attempted in two. Outcomes were reported in different ways, precluding the use of meta-analysis and limiting the strength of our conclusions.The 'no treatment' group in one four-arm trial has been used as the comparison group for the composite outcome (intensity and frequency of leg cramps) in magnesium, calcium, and vitamin B versus no treatment. This gives it disproportionate weight in the overall analysis, thus interpretation of these results should be cautious. Oral magnesium versus placebo/no treatmentMagnesium (taken orally for two to four weeks) did not consistently reduce the frequency of leg cramps compared with placebo or no treatment. Outcomes that showed

  17. Leg power among malaysian netball players | Geok | African Journal ...

    African Journals Online (AJOL)

    The purpose of the study was to compare the leg power among Malaysian national netball players according to their age and playing position. The Vertical Jump Test was chosen to measure the leg power by using “Digital Indication Jump Meter” device. The results of the Vertical Jump Test were used to compare the leg ...

  18. Protection against high intravascular pressure in giraffe legs

    DEFF Research Database (Denmark)

    Petersen, Karin K; Hørlyck, Arne; Østergaard, Kristine Hovkjær

    2013-01-01

    The high blood pressure in giraffe leg arteries renders giraffes vulnerable to edema. We investigated in 11 giraffes whether large and small arteries in the legs and the tight fascia protect leg capillaries. Ultrasound imaging of foreleg arteries in anesthetized giraffes and ex vivo examination...

  19. Immediate effects of the trunk stabilizing exercise on static balance parameters in double-leg and one-leg stances

    OpenAIRE

    Kim, Jwa-jun; Park, Se-yeon

    2016-01-01

    [Purpose] The purpose of this study was to evaluate the immediate effect of stabilizing exercise using the PNF technique on standing balance in one-leg and double-leg stances. [Subjects and Methods] The present study recruited 34 healthy participants from a local university. The Participants performed four balance tests (double-leg stance with and without vision, one-leg stance with and without vision), before and after exercise. The exercise consisted of exercises performed using PNF techniq...

  20. En Defensa del Fin de Lucro en Salud.

    OpenAIRE

    Ramón Abel Castaño Yepes

    2007-01-01

    INTRODUCCIÓN Uno de los planteamientos de fondo sobre los que se ha basado la crítica al sistema de seguridad social en salud creado por la ley 100, es el de la inconveniencia del fin de lucro en la organización del sistema (Academia de Medicina, 1999). Sin embargo, los argumentos basados en este planteamiento parten de premisas que no necesariamente son ciertas, y por lo tanto sus conclusiones no necesariamente son válidas. Así pues, una vez analizadas más de cerca dichas pr...

  1. Compensation of airflow maldistribution in fin-and-tube evaporators

    DEFF Research Database (Denmark)

    Kærn, Martin Ryhl; Tiedemann, Thomas

    2012-01-01

    Compensation of airflow maldistribution in fin-and tube evaporators for residential air-conditioning is investigated with regards to circuitry design and control of individual channel superheats. In particularly, the interlaced and the face split circuitry designs are compared numerically using......, however with lower gains in wet conditions (around 3% in cooling capacity and 7-9% in UA-value). This performance gain in cooling capacity is below the uncertainty in standard experiments, however the gain may be revealed and/or validated by the possible area savings experimentally, i.e. in terms...

  2. Investigations into the dynamic behaviour of finned tube heat exchangers

    International Nuclear Information System (INIS)

    Sandbrink, J.; Stegemann, D.

    1981-01-01

    Atmospheric disturbances due to thunder storms, side wind effects on the shell or ground inversion can impair the heat dissipation of a cooling tower. These effects react on the overall power plant, which is reflected in the varied electrical output. This uncontrolled behaviour has been investigated in detail for the case of a boiling water reactor nuclear power station with indirect natural draught dry cooling and compared with controlled performance. A computer model, which has been checked out by means of experimental investigations on three different types of tube, is presented to describe the dynamic behaviour of finned tube heat exchangers. (orig.) [de

  3. Transfer coefficients for plate fin and elliptical tube heat exchangers

    International Nuclear Information System (INIS)

    Saboya, S.M.; Saboya, F.E.M.

    1981-01-01

    In order to determine transfer coefficients for plate fin and elliptical tube exchangers, mass transfer experiments have been performed using the naphthalene sublimation technique. By means of the heat-mass transfer analogy, the results can be converted to heat transfer results. The transfer coefficients were compared with those for circular tube exchangers and the comparison revealed no major differences. This is a positive outcome, since the use of elliptical tubes may reduce substantially the pressure drop, without affecting the transfer characteristics.(Author) [pt

  4. Development of a Solar Assisted Drying System Using Double-Pass Solar Collector with Finned Absorber

    International Nuclear Information System (INIS)

    Azmi, M S M; Sopian, K; Ruslan, M H; Fudholi, A; Majid, Z A A; Yasin, J M; Othman, M Y

    2012-01-01

    The Solar Energy Research Group, Universiti Kebangsaan Malaysia, International Islamic University Malaysia and Yayasan FELDA has designed and constructed a solar assisted drying system at OPF FELDA Factory, Felda Bukit Sagu 2, Kuantan, Pahang. The drying system has a total of six double-pass solar collectors. Each collector has a length of 480 cm and a width of 120 cm. The first channel depth is 3.5 cm and the second channel depth is 7 cm. Longitudinal fins made of angle aluminium, 0.8 mm thickness were attached to the bottom surface of the absorber plate. The solar collectors are arranged as two banks of three collectors each in series. Internal manifold are used to connect the collectors. Air enters through the first channel and then through the second channel of the collector. An auxiliary heater source is installed to supply heat under unfavourable solar radiation condition. An on/off controller is used to control the startup and shutdown of the auxiliary heater. An outlet temperature of 70–75 °C can be achieved at solar radiation range of 800–900 W/m 2 and flow rate of 0.12 kg/s. The average thermal efficiency of a solar collector is approximately 37%.

  5. Development of a Solar Assisted Drying System Using Double-Pass Solar Collector with Finned Absorber

    Science.gov (United States)

    Azmi, M. S. M.; Othman, M. Y.; Sopian, K.; Ruslan, M. H.; Majid, Z. A. A.; Fudholi, A.; Yasin, J. M.

    2012-09-01

    The Solar Energy Research Group, Universiti Kebangsaan Malaysia, International Islamic University Malaysia and Yayasan FELDA has designed and constructed a solar assisted drying system at OPF FELDA Factory, Felda Bukit Sagu 2, Kuantan, Pahang. The drying system has a total of six double-pass solar collectors. Each collector has a length of 480 cm and a width of 120 cm. The first channel depth is 3.5 cm and the second channel depth is 7 cm. Longitudinal fins made of angle aluminium, 0.8 mm thickness were attached to the bottom surface of the absorber plate. The solar collectors are arranged as two banks of three collectors each in series. Internal manifold are used to connect the collectors. Air enters through the first channel and then through the second channel of the collector. An auxiliary heater source is installed to supply heat under unfavourable solar radiation condition. An on/off controller is used to control the startup and shutdown of the auxiliary heater. An outlet temperature of 70-75 °C can be achieved at solar radiation range of 800-900 W/m2 and flow rate of 0.12 kg/s. The average thermal efficiency of a solar collector is approximately 37%.

  6. Vocalizations associated with pectoral fin contact in bottlenose dolphins (Tursiops truncatus).

    Science.gov (United States)

    Evans-Wilent, J; Dudzinski, K M

    2013-11-01

    Pectoral fin contact in bottlenose dolphins represents one form of tactile communication. Acoustic communication associated with pectoral fin contact is an additional level of communication that may change or enhance the tactile message between two individuals. In this study, we examine vocalization types associated with pectoral fin contact in a group of captive bottlenose dolphins (Tursiops truncatus). From 2006 to 2009, vocalizations potentially associated with 748 pectoral fin contacts were examined: whistles, click trains and overlap of whistles and click trains were documented when associated with fin contact. Dolphins were also documented not vocalizing when exchanging pectoral fin contacts. Call type associated with pectoral fin contact was compared for the proportion of the type of pectoral fin contact, vocalizer sex, initiator and receiver roles, and gender pair. Overall, vocalizations differed significantly by vocalizer role as rubber or rubbee, initiator, and sex. Receivers and rubbees clicked and used overlap vocalizations more frequently, and males produced overlap vocalizations more frequently. These results suggest that whistles may be used to initiate pectoral fin contact or show preference for a particular partner, while click trains may be used to show disinterest in pectoral fin contact or to signal the end of a contact. Examining vocalizations produced in conjunction with tactile contact is a relatively new approach in the study of individual dolphin behavior and may be useful for understanding dolphin social alliances and social preferences for various individuals within a population. Copyright © 2013 Elsevier B.V. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

    Chaulk, S.; Lu, J.; Tan, K.; Arthur, D.; Edwards, R.; Frost, L.; Joachimiak, A.; Glover, J. (Biosciences Division); (Univ. of Alberta)

    2010-11-01

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

  9. 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.

  10. Thermal-fluid characteristics of plate-fin heat sinks cooled by impingement jet

    International Nuclear Information System (INIS)

    Li Hungyi; Chen Kuanying; Chiang Minghung

    2009-01-01

    This work experimentally and numerically studies the thermal-fluid characteristics of plate-fin heat sinks under impingement cooling by adjusting the impinging Reynolds number, the impingement distance, and the fin dimensions. The parameters and the ranges under consideration are the impinging Reynolds number (Re = 5000-25,000), the impingement distance (Y/D = 4-28), the fin width (W/L = 0.08125-0.15625) and the fin height (H/L = 0.375-0.625). The results show that the heat transferred by the heat sink increases with the impinging Reynolds number. The thermal performance can be improved significantly even at low impinging Reynolds number. However, the improvement becomes indistinct as the impinging Reynolds number increases. The thermal resistance declines as the impingement distance increases, and is minimal at Y/D = 20 for various impinging Reynolds numbers. Additionally, the thermal resistance increases as the impingement distance increases further. Increasing the fin width can effectively reduce the thermal resistance. However, as the fin width increases beyond a particular value, the thermal resistance increases dramatically. Reducing the thermal resistance by increasing the fin height depends on a suitable impinging Reynolds number and fin width. Therefore, the effect of the fin height is weaker than that of the impinging Reynolds number or the fin width.

  11. Locomotion with flexible propulsors: I. Experimental analysis of pectoral fin swimming in sunfish.

    Science.gov (United States)

    Lauder, George V; Madden, Peter G A; Mittal, Rajat; Dong, Haibo; Bozkurttas, Meliha

    2006-12-01

    A full understanding of the mechanics of locomotion can be achieved by incorporating descriptions of (1) three-dimensional kinematics of propulsor movement, (2) material properties of the propulsor, (3) power input and control and (4) the fluid dynamics effects of propulsor motion into (5) a three-dimensional computational framework that models the complexity of propulsors that deform and change area. In addition, robotic models would allow for further experimental investigation of changes to propulsor design and for testing of hypothesized relationships between movement and force production. Such a comprehensive suite of data is not yet available for any flexible propulsor. In this paper, we summarize our research program with the goal of producing a comprehensive data set for each of the five components noted above through a study of pectoral fin locomotion in one species of fish: the bluegill sunfish Lepomis macrochirus. Many fish use pectoral fins exclusively for locomotion, and pectoral fins in most fish are integral to generating force during maneuvering. Pectoral fins are complex structures composed of jointed bony supports that are under active control via pectoral fin musculature. During propulsion in sunfish, the fin deforms considerably, has two leading edges, and sunfish can rotate the whole fin or just control individual sections to vector thrust. Fin material properties vary along the length of fin rays and among rays. Experimental fluid dynamic analysis of sunfish pectoral fin locomotion reveals that the fin generates thrust throughout the fin beat cycle, and that the upper and lower edges each produce distinct simultaneous leading edge vortices. The following companion paper provides data on the computational approach taken to understand locomotion using flexible pectoral fins.

  12. Clinical quality indicators of venous leg ulcers

    DEFF Research Database (Denmark)

    Kjaer, Monica L; Mainz, Jan; Soernsen, Lars T

    2005-01-01

    and reliable evidence-based quality indicators of venous leg ulcer care. A Scandinavian multidisciplinary, cross-sectional panel of wound healing experts developed clinical quality indicators on the basis of scientific evidence from the literature and subsequent group nominal consensus of the panel......; an independent medical doctor tested the feasibility and reliability of these clinical indicators, assessing the quality of medical technical care on 100 consecutive venous leg ulcer patients. Main outcome measures were healing, recurrence, pain, venous disease diagnosis, differential diagnosis and treatment......%) were assessed for venous surgery. Distal arterial pressure was measured following initial examination in 33 of the patients (34%). All patients (100%) were prescribed compression therapy. Of the 98 patients, 11 (11%) had ulcers recur in 3 months and 72 (73%) healed in 12 months, which is in line...

  13. Is preeclampsia associated with restless legs syndrome?

    OpenAIRE

    Ramirez, J O; Cabrera, S A S; Hidalgo, H; Cabrera, S G; Linnebank, M; Bassetti, C L; Kallweit, U

    2013-01-01

    OBJECTIVE: Restless legs syndrome (RLS) is a common neurologic disorder. Secondary RLS includes pregnancy and iron deficiency. Prevalence of RLS in pregnancy ranges from 11% to 27%. We aimed to assess the frequency and characteristics of RLS in pregnancy in a Peruvian population and to evaluate the possible pregnancy or delivery complications due to RLS. METHODS: We assessed 218 consecutive expectant mothers at the inpatient clinic of the Hospital San Bartolome in Lima, Peru. Assessment wa...

  14. Genetic aspects of restless legs syndrome

    OpenAIRE

    Dhawan, V; Ali, M; Chaudhuri, K R

    2006-01-01

    Restless legs syndrome (RLS), also known as Ekbom syndrome, is a common movement disorder with sensorimotor symptoms occurring during sleep and quiet wakefulness. The underlying cause for RLS is unknown but genetic influences play a strong part in the pathogenesis of RLS, particularly when the condition starts at a young age. This review explores the genetic basis of RLS and related phenotypic variations. Recently, three loci showing vulnerability to RLS have been described in French‐Canadian...

  15. Restless legs syndrome and pregnancy: A review

    OpenAIRE

    Srivanitchapoom, Prachaya; Pandey, Sanjay; Hallett, Mark

    2014-01-01

    Restless legs syndrome (RLS) is a common sensorimotor neurological disorder that is diagnosed according to the revised criteria of the International RLS Study Group (IRLSSG). The pathophysiology of RLS is still unknown and its prevalence is influenced by ethnicity, age, and gender. RLS is divided into two types by etiology: primary or idiopathic and secondary. Primary RLS is strongly influenced by a genetic component while secondary RLS is caused by other associated conditions such as end-sta...

  16. Quality-controlled dose reduction of full-leg radiography in patients with knee malalignment

    International Nuclear Information System (INIS)

    Kloth, Jost Karsten; Neumann, Regina; Stiller, Wolfram; Kauczor, Hans-Ulrich; Weber, Marc-Andre; Stillfried, Eva von; Ewerbeck, Volker

    2015-01-01

    Digital plain radiographs of the full leg are frequently performed examinations of children and young adults. Thus, the objective of this work was to reduce the radiation exposure dependent on specific indications, and to determine objective quality-control criteria to ensure accurate assessment. Institutional review board approval and informed consent of all participants were obtained. In this prospective, randomized controlled, blinded, two-armed single-center study, 288 evaluable patients underwent plain radiography of the full leg with standard and reduced doses. The evaluation of the plain radiographs was conducted using the following criteria: mechanical axis, leg length, and maturation of the epiphyseal plate. Two blinded radiologists evaluated these criteria using a score ranging from 1 (definitely assessable) to 4 (not assessable). If a single criterion had been evaluated with a score of 3 or more points or all criteria with 2 points, the radiograph was scored as ''not assessable''. The study was designed as a non-inferiority trial. Eleven (3.8 %) examined X-rays were scored as not assessable. The rate of non-assessable radiographs with 33 % reduced dose was significantly not inferior to the rate of non-assessable radiographs with standard dose. The evaluation of the quality criteria was dose independent. Full-leg plain radiography in patients with knee malalignment can be performed at 33 % reduced dose without loss of relevant diagnostic information. (orig.)

  17. Quality-controlled dose reduction of full-leg radiography in patients with knee malalignment

    Energy Technology Data Exchange (ETDEWEB)

    Kloth, Jost Karsten; Neumann, Regina; Stiller, Wolfram; Kauczor, Hans-Ulrich; Weber, Marc-Andre [University Hospital Heidelberg, Department of Diagnostic and Interventional Radiology, Heidelberg (Germany); Stillfried, Eva von; Ewerbeck, Volker [University Hospital Heidelberg, Department of Orthopedic and Trauma Surgery, Heidelberg (Germany)

    2014-12-05

    Digital plain radiographs of the full leg are frequently performed examinations of children and young adults. Thus, the objective of this work was to reduce the radiation exposure dependent on specific indications, and to determine objective quality-control criteria to ensure accurate assessment. Institutional review board approval and informed consent of all participants were obtained. In this prospective, randomized controlled, blinded, two-armed single-center study, 288 evaluable patients underwent plain radiography of the full leg with standard and reduced doses. The evaluation of the plain radiographs was conducted using the following criteria: mechanical axis, leg length, and maturation of the epiphyseal plate. Two blinded radiologists evaluated these criteria using a score ranging from 1 (definitely assessable) to 4 (not assessable). If a single criterion had been evaluated with a score of 3 or more points or all criteria with 2 points, the radiograph was scored as ''not assessable''. The study was designed as a non-inferiority trial. Eleven (3.8 %) examined X-rays were scored as not assessable. The rate of non-assessable radiographs with 33 % reduced dose was significantly not inferior to the rate of non-assessable radiographs with standard dose. The evaluation of the quality criteria was dose independent. Full-leg plain radiography in patients with knee malalignment can be performed at 33 % reduced dose without loss of relevant diagnostic information. (orig.)

  18. Proprioceptive Actuation Design for Dynamic Legged locomotion

    Science.gov (United States)

    Kim, Sangbae; Wensing, Patrick; Biomimetic Robotics Lab Team

    Designing an actuator system for highly-dynamic legged locomotion exhibited by animals has been one of the grand challenges in robotics research. Conventional actuators designed for manufacturing applications have difficulty satisfying challenging requirements for high-speed locomotion, such as the need for high torque density and the ability to manage dynamic physical interactions. It is critical to introduce a new actuator design paradigm and provide guidelines for its incorporation in future mobile robots for research and industry. To this end, we suggest a paradigm called proprioceptive actuation, which enables highly- dynamic operation in legged machines. Proprioceptive actuation uses collocated force control at the joints to effectively control contact interactions at the feet under dynamic conditions. In the realm of legged machines, this paradigm provides a unique combination of high torque density, high-bandwidth force control, and the ability to mitigate impacts through backdrivability. Results show that the proposed design provides an impact mitigation factor that is comparable to other quadruped designs with series springs to handle impact. The paradigm is shown to enable the MIT Cheetah to manage the application of contact forces during dynamic bounding, with results given down to contact times of 85ms and peak forces over 450N. As a result, the MIT Cheetah achieves high-speed 3D running up to 13mph and jumping over an 18-inch high obstacle. The project is sponsored by DARPA M3 program.

  19. Sleep board review question: restless legs

    Directory of Open Access Journals (Sweden)

    Omobomi O

    2018-02-01

    Full Text Available No abstract available. Article truncated after 150 words. Ms. Jones (not her real name is a 63-year-old woman who states that she gets very fidgety when sitting in a theater, watching a movie or when flying long distances on a plane. She is unable to find words to describe the sensation but she states that moving her legs make them feel better. Lately, she has been getting this feeling almost every night. She reports no leg discomfort in the daytime. She denies muscle cramps her legs. She had some recent investigations done by her primary care physician because of complaints of fatigue. Which of the following will be helpful in the diagnosis and management in this patient? 1. An overnight polysomnogram showing apnea hypopnea index of 1.6 events per hour and no periodic limb movements (PLMs 2. Ferritin level of 18 ng/ml (normal range 20-200 ng/ml 3. Serum Bicarbonate of 29 mEq/L (normal range 23-29 mEq/L 4. Thyroid …

  20. Restless Legs Syndrome Among the Elderly

    Directory of Open Access Journals (Sweden)

    Pei-Hao Chen

    2009-12-01

    Full Text Available Restless legs syndrome is a sleep and movement disorder that affects 5–15% of the general population, with an increased prevalence among the elderly population. It not only affects quality of life but also increases risk of mortality among older adults. The diagnosis is based on clinical symptoms of the patient by four minimal essential criteria. Restless legs syndrome can be divided into primary or secondary causes. Examination should be performed to rule out potentially treatable illnesses, such as iron deficiency, renal failure or peripheral neuropathy, especially among elderly patients. The initial approach to restless legs syndrome should be nonpharmacologic management, such as good sleep hygiene, regular exercise, cognitive behavioral therapy and avoidance of certain aggravating drugs. An algorithm based on scientific evidence and expert opinion was developed for guidance of treatment. Combination or change of medication can be applied to resistant or difficult cases. Since elderly patients are prone to treatment-related side effects, the best strategy is to start medication cautiously and at the lowest recommended dosage.

  1. Patella dislocation with vertical axis rotation: the "dorsal fin" patella.

    Science.gov (United States)

    Gamble, David; Otto, Quentin; Carrothers, Andrew D; Khanduja, Vikas

    2015-01-01

    A 44-year-old woman presented following minor trauma to her right knee. While dancing she externally rotated around a planted foot and felt sudden pain in her right knee. She presented with her knee locked in extension with a "dorsal fin" appearance of the soft tissues tented over the patella. This was diagnosed as a rare case of an intraarticular patella dislocation, which was rotated 90 degrees about the vertical axis. Closed reduction in the emergency room was unsuccessful but was achieved in theatre under general anaesthetic with muscle relaxation. Postreduction arthroscopy demonstrated that no osteochondral or soft tissue damage to the knee had been sustained. In patients presenting with a knee locked in extension with tenting of skin over the patella (the "dorsal fin" appearance), intra-articular patella dislocation should be suspected. Attempts to reduce vertical patella dislocations under sedation with excessive force or repeatedly without success should be avoided to prevent unnecessary damage to the patellofemoral joint. In this clinical situation we recommend closed reduction under general anaesthetic followed by immediate knee arthroscopy under the same anaesthetic to ensure that there is no chondral damage to the patella or femoral trochlea and to rule out an osteochondral fracture.

  2. 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.

  3. 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

  4. FinFET and UTBB for RF SOI communication systems

    Science.gov (United States)

    Raskin, Jean-Pierre

    2016-11-01

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

  5. Can't Curb the Urge to Move? Living with Restless Legs Syndrome

    Science.gov (United States)

    ... Sleep? Wise Choices Recognizing Restless Legs Restless legs syndrome brings all 4 of these characteristics: A strong urge to move your legs, often with unpleasant feelings like tingling, burning or throbbing in the legs. Symptoms that get better ... Legs Syndrome Fact Sheet What Is Restless Legs Syndrome? Brain ...

  6. Restless Legs Syndrome and Leg Motor Restlessness in Parkinson’s Disease

    Directory of Open Access Journals (Sweden)

    Keisuke Suzuki

    2015-01-01

    Full Text Available Sleep disturbances are important nonmotor symptoms in Parkinson’s disease (PD that are associated with a negative impact on quality of life. Restless legs syndrome (RLS, which is characterized by an urge to move the legs accompanied by abnormal leg sensations, can coexist with PD, although the pathophysiology of these disorders appears to be different. RLS and PD both respond favorably to dopaminergic treatment, and several investigators have reported a significant relationship between RLS and PD. Sensory symptoms, pain, motor restlessness, akathisia, and the wearing-off phenomenon observed in PD should be differentiated from RLS. RLS in PD may be confounded by chronic dopaminergic treatment; thus, more studies are needed to investigate RLS in drug-naïve patients with PD. Recently, leg motor restlessness (LMR, which is characterized by an urge to move the legs that does not fulfill the diagnostic criteria for RLS, has been reported to be observed more frequently in de novo patients with PD than in age-matched healthy controls, suggesting that LMR may be a part of sensorimotor symptoms intrinsic to PD. In this paper, we provide an overview of RLS, LMR, and PD and of the relationships among these disorders.

  7. Differences in take-off leg kinetics between horizontal and vertical single-leg rebound jumps.

    Science.gov (United States)

    Kariyama, Yasushi; Hobara, Hiroaki; Zushi, Koji

    2017-06-01

    This study aimed to clarify the differences between the horizontal single-leg rebound jump (HJ) and vertical single-leg rebound jump (VJ) in terms of three-dimensional joint kinetics for the take-off leg, while focusing on frontal and transverse plane movements. Eleven male track and field athletes performed HJ and VJ. Kinematic and kinetic data were calculated using data recorded with a motion capture system and force platforms. The hip abduction torque, trunk lateral flexion torque (flexion for the swing-leg side), hip external and internal torque, trunk rotational torque, and the powers associated with these torques were larger when performing HJ because of resistance to the impact ground reaction force and because of pelvic and posture control. Pelvic rotation was noted in HJ, and this was controlled not only by the hip and trunk joint torque from the transverse plane but also by the hip abduction torque. Therefore, hip and trunk joint kinetics in the frontal and transverse plane play an important role in a single-leg jump, regardless of the jumping direction, and may also play a more important role in HJ than in VJ.

  8. Evidence for the secondary sexual development of the anal fin in female kokanee salmon Oncorhynchus nerka.

    Science.gov (United States)

    Thorn, M W; Morbey, Y E

    2016-02-01

    This study examines whether the anal fin undergoes secondary sexual development similar to other reproductive traits in salmonids. This hypothesis was tested by comparing the anal-fin size of female kokanee salmon Oncorhynchus nerka that were in the early and late stages of sexual development. Females in an advanced stage of maturation had significantly larger anal fins relative to females in an early state of maturation (+4-7%), indicating that the anal fin undergoes secondary sexual development. The magnitude of this secondary growth was comparable with snout length (+9-10%), which is known to undergo secondary sexual development in female salmonids. When morphological trait dimensions were compared between the sexes, the anal fin was the only morphological trait found to have a female-biased sexual size dimorphism. This is the first study to show that the anal fin of female salmonids undergoes secondary sexual development. © 2015 The Fisheries Society of the British Isles.

  9. Thermal performance of functionally graded parabolic annular fins having constant weight

    Energy Technology Data Exchange (ETDEWEB)

    Gaba, Vivek Kumar; Tiwari, Anil Kumar; Bhowmick, Shubhankar [National Institute of Technology Raipur, Raipur (India)

    2014-10-15

    The proposed work reports the performance of parabolic annular fins of constant weight made of functionally graded materials. The work involves computation of temperature gradient, efficiency and effectiveness of such fins and compares the performances for different functionally graded parabolic fin profiles obtained by varying grading parameters and profile parameters respectively keeping the weight of the fins constant. The functional grading of thermal conductivity is based on a power function of radial co-ordinate which consists of parameters, namely grading parameters, varying which different grading combinations are studied. A general second order ordinary differential equation has been derived for all the profiles and material grading. The efficiency and effectiveness of the annular fins of different profile and grading combinations have been calculated and plotted and the results reveal the dependence of fin performance on profile and grading parameter.

  10. Forced convective performance of perforated circular pin-fin heat sinks

    Science.gov (United States)

    Wen, Mao-Yu; Yeh, Cheng-Hsiung

    2017-05-01

    This study examines heat transfer performance under forced convection for two different types (Type A and Type B) of pin-fin heat sinks with and without a hollow in the heated base. The effects of the Reynolds number, heights of the fin and base plate, finning factor, heat sink porosity and perforated base plate on the heat-transfer coefficient, fin effectiveness and pressure drop were investigated and evaluated. The present study strongly suggests the use of a small hollow [( D h / D b ) plate of the pin-fin heat sink. In order to obtain insight into the fluid flow phenomena, flow visualization was also made to observe the detailed fluid flow characteristics of the present pin-fin heat sinks.

  11. Effect of Renal Transplantation in Restless Legs Syndrome.

    Science.gov (United States)

    Kahvecioglu, Serdar; Yildiz, Demet; Buyukkoyuncu, Nilufer; Celik, Huseyin; Tufan, Fatih; Kılıç, Ahmet Kasım; Gul, Bulent; Yildiz, Abdulmecid

    2016-02-01

    Restless legs syndrome is a disorder in which patients have irresistible urge to move legs during rest. Restless legs syndrome seems to be common in end-stage renal disease. After a successful renal transplant, symptoms ameliorate with renal function improvement and restless legs syndrome is seen less in this population. Here, we aimed to investigate restless legs syndrome frequency and associated factors in renal transplant patients. In a cross-sectional study with 193 patients (116 hemodialysis patients, 45 transplant patients, and 32 controls), the presence of restless legs syndrome was assessed using the Restless Legs Syndrome Questionnaire. Medical history, demographic, and laboratory data were collected from the patients' medical records. Patients were questioned about the presence of restless legs syndrome using the Restless Legs Syndrome Questionnaire. Patients were evaluated with Beck Depression Scale for depression and Pittsburgh tests for sleep disturbances. While the rate of restless legs syndrome was similar between transplants and controls, it was significantly greater in hemodialysis patients. Hemodialysis patients and controls had similar depression scores that were higher compared with transplant patients. Pittsburgh score was similar in transplant patients and controls and significantly increased in the hemodialysis patients. The rate of insomnia was significantly higher in the hemodialysis patients compared with the other 2 groups. Logistic regression analysis revealed independent correlates of restless legs syndrome as insomnia, Beck depression score, and being on hemodialysis. Linear regression analysis showed that independent correlates of higher Pittsburgh score were higher depression score, higher age, and presence of restless legs syndrome. The prevalence of restless legs syndrome is significantly lower in transplant patients than it is in patients on maintenance dialysis. In renal transplant patients, restless legs syndrome frequency was

  12. 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.

  13. 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

  14. Computational Fluid Dynamics (CFD) Simulations of a Finned Projectile with Microflaps for Flow Control

    Science.gov (United States)

    2016-04-01

    ARL-TR-7660 ● APR 2016 US Army Research Laboratory Computational Fluid Dynamics (CFD) Simulations of a Finned Projectile with... Computational Fluid Dynamics (CFD) Simulations of a Finned Projectile with Microflaps for Flow Control by Jubaraj Sahu Weapons and Materials Research...TITLE AND SUBTITLE Computational Fluid Dynamics (CFD) Simulations of a Finned Projectile with Microflaps for Flow Control 5a. CONTRACT NUMBER 5b

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

    Science.gov (United States)

    Hirbodi, Kamran; Yaghoubi, Mahmood

    2016-08-01

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

  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. A Numerical Investigation of the Thermal-Hydraulic Characteristics of Perforated Plate Fin Heat Sinks

    OpenAIRE

    Al-Sallami, W; Al-Damook, A; Thompson, HM

    2017-01-01

    The benefits of using notch, slot and multiple circular perforations in plate fin heat sinks (PFHSs), are investigated numerically, using a conjugate heat transfer model. Comparisons show that each type of perforation can provide significantly reduced pressure drops over PFHSs but that fins with slot perforations provide the most effective design in terms of heat transfer and pressure drop. The practical benefits of each type of perforated fin for micro-electronics cooling is also explored an...

  18. Medical exposure to ionizing radiations at diagnosis aim of the French population: situation at the end of 2002 in order to implement a surveillance system;Exposition medicale aux rayonnements ionisants a visee diagnostique de la population francaise: etat des lieux fin 2002 en vue de la mise en place d'un systeme de surveillance

    Energy Technology Data Exchange (ETDEWEB)

    Donadieu, J.; Pirard, Ph. [Institut de veille sanitaire, Saint-Maurice (France); Scanff, P.; Aubert, B. [Institut de Radioprotection et de Surete Nucleaire, 92 - Fontenay aux Roses (France)

    2006-04-15

    The principal result of this study, in the perspective of the implementation of an epidemiological follow-up of radiological practices, is to show that the scanner and the interventional radiology, that regroup about 8% and 1.5% of the examinations number, represent respectively about 35% and 19% of the dose to the population. These examinations are in regular progression these last years. A such evaluation allows to better adapt the efforts of the epidemiological surveillance of radiological practices. Our evaluation of the situation in France in 2002 allows a comparison with the previous data registered in France but also international comparisons. The comparison of French data during the twenty last years is based, firstly, on the comparison of the number of examinations. on this period, we observe a reduction of abdomen examinations with injection of contrast product without substitution at the profit of abdomen scanner but likely at the profit of non irradiating examinations such MRI or echography. Conversely, other indications of the scanner have been developed (head and thorax). The resultant of changes in the radiological practice in term of exposure to X radiation of the population is more difficult to analyse. In addition of the number of examinations, the radiological technique has reduced the exposure. More, the coefficient of weighting used for the calculation of efficient dose have been changed in 1990 with the passage of the ICRP 26 to the ICRP 60 recommendation. The international comparisons are also a problem of method: different approaches to compare acts, values of average efficient doses by examination are referred to doses established in Great britain when the real average efficient doses by examination vary from a country to another. An European project called 'Dose Datamed' is underway to homogenize the methods of collection. The strategies of examinations uses can be different in each country. The cumulative exposure of patients

  19. Leg movements during wakefulness in restless legs syndrome: time structure and relationships with periodic leg movements during sleep.

    Science.gov (United States)

    Ferri, Raffaele; Manconi, Mauro; Plazzi, Giuseppe; Bruni, Oliviero; Cosentino, Filomena I I; Ferini-Strambi, Luigi; Zucconi, Marco

    2012-05-01

    Approximately one third of patients with restless legs syndrome (RLS) also show periodic leg movements (PLM) during relaxed wake fulness (PLMW). In contrast with the large amount of data published on periodic leg movements during sleep (PLMS), PLMW have received less attention from the scientific community. The objective of this study was to evaluate the correlations/differences of time-structure and response to a dopamine-agonist between PLMW and PLMS in patients with RLS. Ninety idiopathic RLS patients and 28 controls were recruited. Subjects underwent clinical and neurophysiological evaluation, hematological screening, and one or two consecutive full-night polysomnographic studies. A subset of patients received 0.25mg of pramipexole or placebo before the second recording. Polysomnographic recordings were scored and LM activity was analyzed during sleep and during the epochs of wakefulness occurring during the first recording hour. RLS patients had higher LM activity during wakefulness than controls, but with a similar periodicity. Even if correlated, the ability of the PLMW index to predict the PLMS index decreased with increasing LM activity. Intermovement intervals during wakefulness showed one peak only at approximately 4s, gradually decreasing with increasing interval in both patients and controls. The effect of pramipexole was very limited and involved the small periodic portion of LM activity during wakefulness. PLMW index and PLMS index were correlated; however, the magnitude of this correlation was not sufficient to suggest that PLMW can be good predictors of PLMS. Short-interval LM activity during wakefulness and sleep might be linked to the severity of sleep disruption in RLS patients and the differences between their features obtained during wakefulness or sleep might be relevant for the diagnosis of sleep disturbances in RLS. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Restless legs syndrome and nocturnal leg cramps: a review and guide to diagnosis and treatment.

    Science.gov (United States)

    Tipton, Philip W; Wszołek, Zbigniew K

    2017-12-22

    Restless legs syndrome (RLS) and nocturnal leg cramps (NLCs) are common disorders affecting 7.0% and 24.1% of the population in some European countries, respectively. Patients suffering from RLS experience uncomfortable nocturnal sensations in the legs with the urge to move that dissipates while moving. NLC is characterized by abrupt muscle contraction, most often in the gastrocnemius or foot muscles, which occurs at night and may result in significant sleep disturbances. The diagnosis of these disorders has presented a challenge to health care providers because of symptom overlap with other sensory and motor disturbances with nocturnal predominance. Treatment options and approaches are lacking, partially because of our currently incomplete understanding of the pathophysiological mechanisms underlying these conditions. We reviewed the medical literature to provide a comprehensive assessment of RLS and NLC with a focus on improved diagnostic accuracy and treatment approaches.

  1. 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

  2. Numerical simulation and experimental research of a flexible caudal fin by piezoelectric fiber composite

    Directory of Open Access Journals (Sweden)

    Yuan-Lin Guan

    2015-07-01

    Full Text Available A flexible caudal fin made of the macro fiber composites and the carbon fiber orthotropic composite was investigated by the numerical simulations and the experiments. First, a three-dimensional numerical simulation procedure was adopted to research the torsion propulsion mode of the caudal fin and the impact of the water for the structural torsion frequency of the caudal fin. Then, a two-dimensional unsteady fluid computational method was used to analyze the hydrodynamic performance with the periodic swing of the caudal fin on the torsion mode. Based on the simulation results, the flow field was demonstrated and discussed. The interaction between the caudal fin and the water was explained. Finally, the laser vibrometer system was built to verify the torsion propulsion mode. Meanwhile, the application of the caudal fin was realized on the torsion propulsion, and the measured system was established to demonstrate the performance of the caudal fin. The established simulation procedures and experimental methods in this study may provide guidance to the fins made of the composite materials during the structural design and the investigation of the flow field characteristics with the movement of the fins.

  3. 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.......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....

  4. 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.

  5. 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

  6. Preliminary experiments on natural convection heat transfer of the vertical plate with fin arrays

    International Nuclear Information System (INIS)

    Kim, Seung Sin; Chung, Bum Jin

    2012-01-01

    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 of the fin arrays should be optimized. According to Welling and Woodridge, a natural convection on vertical plate fin is function of Nu = f(Gr, Pr, L, t, S, H). Present study aimed at the determination of the effects of geometric parameters, L(fin length) and S(fin spacing), and H(fin height) on the heat transfer, in order to find optimum parameters on the natural convection heat transfer

  7. 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.

  8. 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.

  9. Actigraphic assessment of periodic leg movements in patients with restless legs syndrome.

    Science.gov (United States)

    Cippà, Maria A T; Baumann, Christian R; Siccoli, Massimiliano M; Bassetti, Claudio L; Poryazova, Rositsa; Werth, Esther

    2013-10-01

    The diagnosis of restless legs syndrome (RLS) relies upon diagnostic criteria which are based on history only, and dopaminergic treatment is not normally the first choice of treatment for all patients. It would be worthwhile to identify patients non-responsive to dopaminergic treatment beforehand, because they may suffer from a restless legs-like syndrome and may require alternative treatment. We included retrospectively 24 adult patients fulfilling the four essential criteria for restless legs and 12 age-matched healthy controls. They were investigated by ambulatory actigraphy from both legs over three nights, and patients started treatment with dopamine agonists after this diagnostic work-up. We examined 12 responders to dopaminergic treatment and 12 non-responders and studied the association between response to dopaminergic treatment and the periodic limb movement index (PLMI) as assessed with actigraphy. Demographic characteristics, excessive daytime sleepiness and fatigue at baseline were similar in all three groups. Baseline RLS severity was similar between responders and non-responders [International Restless Legs Severity Scale (IRLS): 25 ± 9 and 24 ± 8]. Group comparisons of PLMI before treatment initiation showed significant differences between the three groups. Post-hoc pairwise comparisons revealed that healthy controls had significantly lower PLMI (4.9 ± 4.5) than responders (29.3 ± 22.7) and non-responders (13.3 ± 11.2). Similarly, the PLMI in responders was lower than in non-responders. PLMI day-to-day variability did not differ between responders and non-responders and there was no correlation between treatment effect, as assessed by the decrease of the IRLS and baseline PLMI. Our retrospective study indicates that actigraphy to assess periodic limb movements may contribute to a better diagnosis of dopamine-responsive restless legs syndrome. © 2013 European Sleep Research Society.

  10. Immobilization tests and periodic leg movements in sleep for the diagnosis of restless leg syndrome.

    Science.gov (United States)

    Montplaisir, J; Boucher, S; Nicolas, A; Lesperance, P; Gosselin, A; Rompré, P; Lavigne, G

    1998-03-01

    Patients with restless leg syndrome (RLS) complain of motor restlessness, usually occurring while they rest in the evening. Two immobilization tests have been described to assess leg restlessness in these patients. In the first test, the patient sits in bed with his or her legs outstretched while electromyograms are recorded from right and left anterior tibialis muscles for an hour (Suggested Immobilization Test [SIT]); in the second test, the legs are immobilized in a stretcher (Forced Immobilization Test [FIT]). In the current study, the SIT and the FIT were compared in patients with RLS and normal control subjects matched for age and sex. More leg movements were seen in patients than in controls during immobilization tests, especially the SIT. These movements were periodic, occurring at a frequency of approximately one every 12 seconds. The SIT (index > 40) was found to discriminate between RLS and control subjects better than the FIT (index > 25). Patients were also recorded during two consecutive nights to measure periodic leg movements in sleep (PLMS). A SIT index greater than 40 and a PLMS index greater than 11 (highest PLMS index of 2 consecutive nights) were found to discriminate patients with RLS from control subjects with similar power. With each of these two measures, the clinical diagnosis was correctly predicted in 81% of patients and 81% of the control subjects. The SIT has several advantages over the measure of the PLMS index; it does not require an all-night polygraphic recording and can be administered several times a day to measure circadian fluctuation of motor restlessness.

  11. Profile of altered brain iron acquisition in restless legs syndrome

    Science.gov (United States)

    Ponnuru, Padmavathi; Wang, Xin-Sheng; Patton, Stephanie M.; Allen, Richard P.; Earley, Christopher J.

    2011-01-01

    Restless legs syndrome is a neurological disorder characterized by an urgency to move the legs during periods of rest. Data from a variety of sources provide a compelling argument that the amount of iron in the brain is lower in individuals with restless legs syndrome compared with neurologically normal individuals. Moreover, a significant percentage of patients with restless legs syndrome are responsive to intravenous iron therapy. The mechanism underlying the decreased iron concentrations in restless legs syndrome brains is unknown. We hypothesize that the source of the brain iron deficit is at the blood–brain interface. Thus we analysed the expression of iron management proteins in the epithelial cells of the choroid plexus and the brain microvasculature in post-mortem tissues. The choroid plexus, obtained at autopsy, from 18 neurologically normal controls and 14 individuals who had primary restless legs syndrome was subjected to histochemical staining for iron and immunostaining for iron management proteins. Iron and heavy chain ferritin staining was reduced in the epithelial cells of choroid plexus in restless legs syndrome. Divalent metal transporter, ferroportin, transferrin and its receptor were upregulated in the choroid plexus in restless legs syndrome. Microvessels were isolated from the motor cortex of 11 restless legs syndrome and 14 control brains obtained at autopsy and quantitative immunoblot analyses was performed. Expression of heavy chain ferritin, transferrin and its receptor in the microvessels from restless legs syndrome was significantly decreased compared with the controls but divalent metal protein 1, ferroportin, prohepcidin, mitochondrial ferritin and light-chain ferritin remained unchanged. The presence of an iron regulatory protein was demonstrated in the brain microvasculature and the activity of this protein is decreased in restless legs syndrome; a finding similar to our earlier report in neuromelanin cells from the substantia

  12. Leg movement tracking in automatic video-based one-leg stance evaluation.

    Science.gov (United States)

    Kawa, Jacek; Stępień, Paula; Kapko, Wojciech; Niedziela, Aleksandra; Derejczyk, Jarosław

    2018-04-01

    Falls are a major risk in elder population. Early diagnosis is therefore an important step towards increasing the safety of elders. One of the common diagnostic tests is the Berg Balance Scale (BBS), consisting of 14 exercises arranged from the easiest (sitting-to-standing) to the most demanding (one-leg stance). In this study a novel approach to the automatic assessment of the time in which the patient can remain in the one-leg stance position without loosing balance is introduced. The data is collected using a regular video camera. No markers, special garments, or system calibration are required. Two groups are examined. The first group consists of 16 students: healthy, young adults (12 female, 4 male, avg. 20yrs±1). The second group consists of 50 elders (39 female, 11 male, avg. 78.8yrs±5.9). Data (short, one minute recordings) are collected in a controlled environment using a digital video recorder (50fps, 1920×1080) fixed to a tripod. Data are processed off-line. First, the region of interest is determined. Next, the Kanade-Lucas-Tomasi tracking is performed. Best tracks are selected based on the registered vertical movement and two tracks are obtained corresponding to the left and right leg movements. Tracks are later subjected to the sparse signal baseline estimation, denoising and thresholding to detect the raised leg. Results are compared frame-wise to the ground truth reference obtained in the manual processing procedure. Both legs are evaluated in the elder group (in all cases several attempts featuring both legs were registered), resulting in 89.18%±11.27% DICE, 93.07%±5.43% sensitivity and 96.94%±6.11% specificity values for both legs. The signal of a single leg is evaluated in the student group (in all cases only one attempt was needed to perform the full examination) resulting in 98.96%±1.2% DICE, 98.78%±1.65% sensitivity and 98.73%±2.69% specificity values. This is the first step towards a video-based system enabling the automatic

  13. Relationship between Leg Mass, Leg Composition and Foot Velocity on Kicking Accuracy in Australian Football.

    Science.gov (United States)

    Hart, Nicolas H; Nimphius, Sophia; Spiteri, Tania; Cochrane, Jodie L; Newton, Robert U

    2016-06-01

    Kicking a ball accurately over a desired distance to an intended target is arguably the most important skill to acquire in Australian Football. Therefore, understanding the potential mechanisms which underpin kicking accuracy is warranted. The aim of this study was to examine the relationship between leg mass, leg composition and foot velocity on kicking accuracy in Australian Football. Thirty-one Australian Footballers (n = 31; age: 22.1 ± 2.8 years; height: 1.81 ± 0.07 m; weight: 85.1 ± 13.0 kg; BMI: 25.9 ± 3.2) each performed ten drop punt kicks over twenty metres to a player target. Athletes were separated into accurate (n = 15) and inaccurate (n = 16) kicking groups. Leg mass characteristics were assessed using whole body DXA scans. Foot velocity was determined using a ten-camera optoelectronic, three-dimensional motion capture system. Interactions between leg mass and foot velocity evident within accurate kickers only (r = -0.670 to -0.701). Relative lean mass was positively correlated with kicking accuracy (r = 0.631), while no relationship between foot velocity and kicking accuracy was evident in isolation (r = -0.047 to -0.083). Given the evident importance of lean mass, and its interaction with foot velocity for accurate kickers; future research should explore speed-accuracy, impulse-variability, limb co-ordination and foot-ball interaction constructs in kicking using controlled with-in subject studies to examine the effects of resistance training and skill acquisition programs on the development of kicking accuracy. Key pointsAccurate kickers expressed a very strong inverse relationship between leg mass and foot velocity. Inaccurate kickers were unable to replicate this, with greater volatility in their performance, indicating an ability of accurate kickers to mediate foot velocity to compensate for leg mass in order to deliver the ball over the required distance.Accurate kickers exhibited larger quantities of relative lean mass and lower quantities

  14. On the biomimetic design of agile-robot legs.

    Science.gov (United States)

    Garcia, Elena; Arevalo, Juan Carlos; Muñoz, Gustavo; Gonzalez-de-Santos, Pablo

    2011-01-01

    The development of functional legged robots has encountered its limits in human-made actuation technology. This paper describes research on the biomimetic design of legs for agile quadrupeds. A biomimetic leg concept that extracts key principles from horse legs which are responsible for the agile and powerful locomotion of these animals is presented. The proposed biomimetic leg model defines the effective leg length, leg kinematics, limb mass distribution, actuator power, and elastic energy recovery as determinants of agile locomotion, and values for these five key elements are given. The transfer of the extracted principles to technological instantiations is analyzed in detail, considering the availability of current materials, structures and actuators. A real leg prototype has been developed following the biomimetic leg concept proposed. The actuation system is based on the hybrid use of series elasticity and magneto-rheological dampers which provides variable compliance for natural motion. From the experimental evaluation of this prototype, conclusions on the current technological barriers to achieve real functional legged robots to walk dynamically in agile locomotion are presented.

  15. On the Biomimetic Design of Agile-Robot Legs

    Directory of Open Access Journals (Sweden)

    Pablo Gonzalez-de-Santos

    2011-11-01

    Full Text Available The development of functional legged robots has encountered its limits in human-made actuation technology. This paper describes research on the biomimetic design of legs for agile quadrupeds. A biomimetic leg concept that extracts key principles from horse legs which are responsible for the agile and powerful locomotion of these animals is presented. The proposed biomimetic leg model defines the effective leg length, leg kinematics, limb mass distribution, actuator power, and elastic energy recovery as determinants of agile locomotion, and values for these five key elements are given. The transfer of the extracted principles to technological instantiations is analyzed in detail, considering the availability of current materials, structures and actuators. A real leg prototype has been developed following the biomimetic leg concept proposed. The actuation system is based on the hybrid use of series elasticity and magneto-rheological dampers which provides variable compliance for natural motion. From the experimental evaluation of this prototype, conclusions on the current technological barriers to achieve real functional legged robots to walk dynamically in agile locomotion are presented.

  16. Robust and efficient walking with spring-like legs

    International Nuclear Information System (INIS)

    Rummel, J; Blum, Y; Seyfarth, A

    2010-01-01

    The development of bipedal walking robots is inspired by human walking. A way of implementing walking could be performed by mimicking human leg dynamics. A fundamental model, representing human leg dynamics during walking and running, is the bipedal spring-mass model which is the basis for this paper. The aim of this study is the identification of leg parameters leading to a compromise between robustness and energy efficiency in walking. It is found that, compared to asymmetric walking, symmetric walking with flatter angles of attack reveals such a compromise. With increasing leg stiffness, energy efficiency increases continuously. However, robustness is the maximum at moderate leg stiffness and decreases slightly with increasing stiffness. Hence, an adjustable leg compliance would be preferred, which is adaptable to the environment. If the ground is even, a high leg stiffness leads to energy efficient walking. However, if external perturbations are expected, e.g. when the robot walks on uneven terrain, the leg should be softer and the angle of attack flatter. In the case of underactuated robots with constant physical springs, the leg stiffness should be larger than k-tilde = 14 in order to use the most robust gait. Soft legs, however, lack in both robustness and efficiency.

  17. Loading and performance of the support leg in kicking.

    Science.gov (United States)

    Ball, Kevin

    2013-09-01

    The punt kick is important in many football codes and support leg kinematics and ground reaction forces have been implicated in injury and performance in kicking. To evaluate ground reaction forces and support leg kinematics in the punt kick. Cross sectional study. Seven elite Australian football players performed maximal kicks into a net using both the preferred and non-preferred legs. A force plate measured ground reaction forces and an optical motion capture system (200Hz) collected kinematic data during the stance phase of the kick. Preferred and non-preferred legs were compared and performance was evaluated by correlating parameters with foot speed at ball contact. Vertical forces were larger than running at a similar speed but did not reach levels that might be considered an injury risk. Braking forces were directed solely posteriorly, as for soccer kicks, but lateral force patterns varied with some players experiencing greater forces medially and others laterally. A more extended support leg, larger peak vertical and braking force during the stance phase and a shorter stance contact time was associated with larger kick leg foot speed at ball contact. No difference existed between the preferred and non-preferred legs for ground reaction forces or support leg mechanics. To punt kick longer, a straighter support leg, less time on the ground and stronger braking should be encouraged. Conditioning the support leg to provide stronger braking potential is recommended. Copyright © 2012 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  18. On the Biomimetic Design of Agile-Robot Legs

    Science.gov (United States)

    Garcia, Elena; Arevalo, Juan Carlos; Muñoz, Gustavo; Gonzalez-de-Santos, Pablo

    2011-01-01

    The development of functional legged robots has encountered its limits in human-made actuation technology. This paper describes research on the biomimetic design of legs for agile quadrupeds. A biomimetic leg concept that extracts key principles from horse legs which are responsible for the agile and powerful locomotion of these animals is presented. The proposed biomimetic leg model defines the effective leg length, leg kinematics, limb mass distribution, actuator power, and elastic energy recovery as determinants of agile locomotion, and values for these five key elements are given. The transfer of the extracted principles to technological instantiations is analyzed in detail, considering the availability of current materials, structures and actuators. A real leg prototype has been developed following the biomimetic leg concept proposed. The actuation system is based on the hybrid use of series elasticity and magneto-rheological dampers which provides variable compliance for natural motion. From the experimental evaluation of this prototype, conclusions on the current technological barriers to achieve real functional legged robots to walk dynamically in agile locomotion are presented. PMID:22247667

  19. Leg stiffness and sprint ability in amputee sprinters.

    Science.gov (United States)

    Hobara, Hiroaki; Tominaga, Shuichi; Umezawa, Shingo; Iwashita, Koudai; Okino, Atsuo; Saito, Taku; Usui, Fumio; Ogata, Toru

    2012-09-01

    Understanding leg stiffness (K (leg)) in amputee sprinters is important for the evaluation of their sprint ability and development of running-specific prostheses (RSP). To investigate K (leg) during hopping in amputee sprinters. Cross-sectional study. Seven transtibial (TT) and seven transfemoral (TF) amputee sprinters, as well as seven non-active able-bodied subjects, performed one-legged hopping matching metronome beats at 2.2 Hz. Amputees hopped on their sound limb whereas able-bodied (AB) subjects hopped on their dominant limb. Using a spring-mass model, K (leg) was calculated from the subjects' body mass, ground contact and flight times. Both TT and TF sprinters demonstrated significantly higher K (leg) than AB subjects. K (leg) during hopping on the sound leg significantly correlated with personal records attained in a 100-m sprint in both TT (r = -0.757) and TF sprinters (r = -0.855). The results of the present study suggest that amputee sprinters have a greater K (leg) during hopping than inactive non-amputees, and that their sprint ability can be predicted from the K (leg) during hopping at 2.2 Hz on the sound limb.

  20. Association between serum hepcidin level and restless legs syndrome.

    Science.gov (United States)

    Dauvilliers, Yves; Chenini, Sofiene; Vialaret, Jérôme; Delaby, Constance; Guiraud, Lily; Gabelle, Audrey; Lopez, Regis; Hirtz, Christophe; Jaussent, Isabelle; Lehmann, Sylvain

    2018-02-08

    To better understand the role of iron homeostasis dysregulation in restless legs syndrome, we compared serum hepcidin and ferritin levels in drug-free patients with primary restless legs syndrome and healthy controls and studied the relationship between hepcidin level and restless legs syndrome severity. One hundred and eight drug-free patients with primary restless legs syndrome (65 women; median age, 61.5 years) and 45 controls (28 women; median age, 53.9 years) were enrolled. Inclusion criteria were: normal ferritin level (>50 ng/mL) and absence of iron disorders, chronic renal or liver failure, and inflammatory or neurological diseases. Each subject underwent a thorough clinical examination and a polysomnography assessment. Serum hepcidin-25 was quantified using a validated mass spectrometry method. Restless legs syndrome severity was evaluated according to the International Restless Legs Syndrome Study Group. Despite no group difference between normal ferritin levels and demographic features, serum hepcidin level and hepcidin/ferritin ratio were higher in patients than in controls. Hepcidin level and hepcidin/ferritin ratio, but not ferritin level, were positively correlated with periodic leg movements during sleep and wakefulness in the whole sample. Hepcidin level seem to be associated with restless legs syndrome severity in a complex U-shaped relationship, without relationship with age at restless legs syndrome onset, positive family history, sleep and depressive symptoms, genetic background, and polysomnographic measurements. No relationship was found between ferritin level and restless legs syndrome severity. In drug-free patients with primary restless legs syndrome, hepcidin level is higher than in controls and may be associated with restless legs syndrome clinical severity. This result emphasizes the complex peripheral iron metabolism deregulation in restless legs syndrome, opening potential perspectives for a personalized approach with a hepcidin

  1. Chiropractic management of patients with bilateral congenital hip dislocation with chronic low back and leg pain.

    Science.gov (United States)

    Diez, Francisco

    2004-05-01

    To discuss conservative methods for treating patients with chronic low back and leg pain associated with the biomechanical and postural alterations related to bilateral congenital hip dislocation. This report describes the cases of 2 adult female subjects with bilateral congenital hip dislocation without acetabula formation who suffered from chronic low back and leg pain managed conservatively by chiropractic methods. The first subject is a 45-year-old woman with a 9-month history of right buttock pain and radiating right leg pain and paresthesia down to the first 2 toes, with a diagnosis of a herniated L4 intervertebral disk. The second subject is a 53-year-old woman who complained of chronic intermittent low back pain and constant unremitting pain on her right leg for the last 3 years. Chiropractic manipulation utilizing Logan Basic apex and double notch contacts, as well as sacroiliac manipulation on a drop table with a sacrum contact and with a posterior to anterior and superior to inferior (PA-SI) rocking thrust, together with a spinal stabilization exercise program, were used on these 2 patients. Both patients had significant clinical improvement, with reduction on the Visual Analogue Scale (VAS) of 67% and 84%, Oswestry Disability Index improvement of 73% and 81%, and an improvement on the Harris hip score of 71% and 44%, respectively. A conservative management approach, including specific chiropractic manipulation and a spinal stabilization exercise program, can help manage the treatment of adult patients with chronic low back and leg pain related to bilateral congenital dislocation of the hips.

  2. Fin-and-tube condenser performance evaluation using neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Ling-Xiao [Institute of Refrigeration and Cryogenics, Shanghai Jiaotong University, Shanghai 200240 (China); Zhang, Chun-Lu [China R and D Center, Carrier Corporation, No. 3239 Shen Jiang Road, Shanghai 201206 (China)

    2010-05-15

    The paper presents neural network approach to performance evaluation of the fin-and-tube air-cooled condensers which are widely used in air-conditioning and refrigeration systems. Inputs of the neural network include refrigerant and air-flow rates, refrigerant inlet temperature and saturated temperature, and entering air dry-bulb temperature. Outputs of the neural network consist of the heating capacity and the pressure drops on both refrigerant and air sides. The multi-input multi-output (MIMO) neural network is separated into multi-input single-output (MISO) neural networks for training. Afterwards, the trained MISO neural networks are combined into a MIMO neural network, which indicates that the number of training data sets is determined by the biggest MISO neural network not the whole MIMO network. Compared with a validated first-principle model, the standard deviations of neural network models are less than 1.9%, and all errors fall into {+-}5%. (author)

  3. Methods and criteria for safety analysis (FIN L2535)

    International Nuclear Information System (INIS)

    1992-12-01

    In response to the NRC request for a proposal dated October 20, 1992, Westinghouse Savannah River Company (WSRC) submit this proposal to provide contractural assistance for FIN L2535, ''Methods and Criteria for Safety Analysis,'' as specified in the Statement of Work attached to the request for proposal. The Statement of Work involves development of safety analysis guidance for NRC licensees, arranging a workshop on this guidance, and revising NRC Regulatory Guide 3.52. This response to the request for proposal offers for consideration the following advantages of WSRC in performing this work: Experience, Qualification of Personnel and Resource Commitment, Technical and Organizational Approach, Mobilization Plan, Key Personnel and Resumes. In addition, attached are the following items required by the NRC: Schedule II, Savannah River Site - Job Cost Estimate, NRC Form 189, Project and Budget Proposal for NRC Work, page 1, NRC Form 189, Project and Budget Proposal for NRC Work, page 2, Project Description

  4. El fin del mundo según Lacunza

    Directory of Open Access Journals (Sweden)

    Fredy Parra C.

    2000-01-01

    Full Text Available El artículo presenta el pensamiento milenarista del jesuita chileno Manuel Lacunza (1731-1801 en torno al fin del mundo. Se indaga la visión del autor sobre el fin del siglo, el fin del milenio y su concepto de bienaventuranza eterna. El lacunzismo sostiene que antes del final de la historia se espera un reino terrestre del Mesías Jesucristo en el cual tendrán pleno cumplimiento las promesas de vida y justicia que Dios ha hecho a la humanidad. En este contexto se explica que para Lacunza el reino mesiánico (milenio comienza con una transformación de la naturaleza que transita a una etapa de mayor perfección y que el mundo nuevo que adviene es mejor que el presente no solamente en lo moral sino también en lo físico y material. Asimismo, el universo renovado, acabada toda generación y corrupción, participará de la plenitud eterna y, tras la resurrección universal, los bienaventurados gozarán juntos eternamente de la contemplación del mundo transfigurado y de la comunión con Dios. Siempre se trata de una transformación de la materia de mal en bien, o de bien en mejor. Se excluye, clara y expresamente, la idea de un "fin del mundo" como aniquilación del mismo.The article presents the millienarist thought of the Chilean Jesuit Manuel Lacunza (1731-1801 regarding the end of the world. It looks into the author’s views on the end of the century, the end of the milliemium, and his concept of eternal beatitude. Lacunza affirms that an earthly kingdom of Jesus Christ the Messiah will come before the end of the history, in which, all the promises of life and justice made by God will have full accomplishment. Within this context, it is easy to undestand that for Lacunza, the messianic kingdom (Millenium starts with a transformation of nature, which moves onto a stage of greater perfection, and that this coming renewed world, is much better than the present one, not only in the moral aspect, but also in the physical and material aspects

  5. Sleep disturbances in restless legs syndrome

    Directory of Open Access Journals (Sweden)

    Jović Jasmina

    2018-01-01

    Full Text Available Background/Aim. Resteless legs syndrome (RLS is chronical neurological disorder characterized by urge to move legs that is usually accompanied by unpleasant sensations in the lower extremities. Sleep disturbance is one of the main accompanying symptoms of RLS which exists in approximatelly 90% of patients. Impairment of sleep is related to daily sleepiness, depressive and anxiety disorders. The aim of this study was to detect frequency and characterisitics of sleep-related symptoms in patients with RLS, and its impairrment to daily sleepiness, fatique, anxiety and depression. Methods. We have examinated 94 patients with RLS. The diagnose of RLS was based on questionnaire with 4 specific questions according to the International Restless Legs Syndrome Study Group (IRLSSG criteria updated in 2003. Severity of symptoms was astimated with IRLSSG Rating Scale, depression and anxiety with Hamilton Depression Rating Scale (HDRS and Hamilton Anxiety Rating Scale (HARS and sleepiness with Epworth Sleepiness scale (ESS. We astimated sleep characteristics and disturbances with specific questionnaire. Results. In our study 79.9% of patients had sleep-related symptoms. Average sleep duration was 6.50 ± 1.42 hours, with average frequency of awakening 2.34 ± 1.69 times per night. Average ESS score was 5.12 ± 4.08 (0–17. Patients with more severe symptoms had higher degree of sleepiness (p = 0.005. Patients with higher symptoms frequency, significantly more often had sleep disturbance (p = 0.016, tiredness and daily sleepiness (p = 0.001. Daily sleepiness (ESS also significantly correlates with depression (p < 0.05 and anxiety (p = 0.012. Conclusion. Our results confirm that sleep disturbances are one of the key accompanying symptoms of RLS which cause daily sleepiness, tiredness, depression and anxiety. Therefore, their early recognition and appropriate treatment must be a priority in RLS patients.

  6. [Bow legged adjectives in ancient literature].

    Science.gov (United States)

    Simon, Frantisek; Steger, Florian

    2011-01-01

    This article addresses the issue of capturing the medical entity called 'curved legs' in a terminologically exact way. In so doing, it refers to the long-lasting process of differentiation of exact nuances of meaning in Ancient Greek and Latin. In the chronological perusal of ancient Greek literature, it becomes evident that the various adjectives employed are often vague when looking at non-medical literature. By contrast, in the Hippocratic corpus these terms are for the first time annotated with explanations intended to lead to a more precise understanding of the described deformity. Further attempts of differentiation can be found in the writings of Galen, who not only distinguishes between outward and inward curvatures, but also between deformities of the thigh and lower leg as well as between pathological and natural curvatures. Latin literature also provides a series of adjectives that were initially often used in the meaning of 'curved' but it was not until Celsus that these were differentiated with respect to the type and direction of the curvature. When comparing Greek and Latin adjectives, it turns out that though the Latin term blaesus can be traced back etymologically to the Greek word beta lambda alpha iota sigma ó zeta, the meaning of beta lambda alpha iota sigma ó zeta does not fully correspond to that of the Latin word. It is not before the later common transliteration of Greek words that this adjective took on the meaning of beta lambda alpha iota sigma ó zeta; however, this was finally lost again. In summary, the article concludes that exact word meanings in ancient literature are often unclear and precise ascriptions of meanings are inconsistent. In the case of "curved legs," this has led to misunderstandings regarding the respective types and directions of the curvature.

  7. Filipinas, fin de siglo: imágenes y realidad

    Directory of Open Access Journals (Sweden)

    Elizalde, María Dolores

    1998-08-01

    Full Text Available The objective of this paper is to present an image of the Philippines at the end of the 19th century, different to the picture of underveloped islands, inhabitated by savages unable to selfgovernment, transmited by the historiography and caricatures of that time. With this purpose, they are studied the process of redefinition of the Spanish colonial goverment, the strengthening of a new filipino society, the development of the economy and commerce, and the strong international interests in the islands.

    El presente artículo pretende ofrecer una imagen de las Filipinas de fin de siglo, diferente de la transmitida por la historiografía tradicional y por la viñetas y caricaturas de la época. Frente a los estereotipos de unas islas atrasadas, incapaces del autogobierno, habitadas por salvajes a los que había que civilizar, se impone una realidad definida por el gobierno colonial de España, en pleno proceso de redefinición; por el afianzamiento de una burguesía ilustrada filipina, la pujanza de una clase campesina y obrera, la fuerza de un movimiento de afirmación nacional, y el desarrollo de una economía agroexportadora en pleno crecimiento; y por la presencia de fuertes intereses internacionales que hay que entender insertos en la marea de expansión colonial y reparto de mercados y territorios ultramarinos; intereses internacionales de los que se da cuenta a través de un análisis de comercio, inversiones y presencia diplomática de las grandes potencias en las Filipinas de fin de siglo.

  8. Nice snake, shame about the legs.

    Science.gov (United States)

    Coates; Ruta

    2000-12-01

    Snakes are one of the most extraordinary groups of terrestrial vertebrates, with numerous specializations distinguishing them from other squamates (lizards and their allies). Their musculoskeletal system allows creeping, burrowing, swimming and even gliding, and their predatory habits are aided by chemo- and thermoreceptors, an extraordinary degree of cranial kinesis and, sometimes, powerful venoms. Recent discoveries of indisputable early fossil snakes with posterior legs are generating intense debate about the evolutionary origin of these reptiles. New cladistic analyses dispute the precise significance and phylogenetic placement of these fossils. These conflicting hypotheses imply radically different scenarios of snake origins and relationships with wide biological implications.

  9. Leg ulcer in lepromatous leprosy - Case report*

    Science.gov (United States)

    Fernandes, Tania Rita Moreno de Oliveira; dos Santos, Talita Suzany Siqueira; Lopes, Ramon Rodrigues de Macedo

    2016-01-01

    In Brazil, leprosy is a widespread infectious and contagious disease. Clinicians and specialists view leprosy broadly as a systemic infection, since, in its manifestations, it mimics many conditions, such as rheumatic, vascular, ENT, neurological and dermatological diseases. There are few studies that characterize the factors associated with ulcers in leprosy. These injuries should be prevented and treated promptly to avoid serious problems like secondary infections, sepsis, carcinomatous degeneration and amputations. We describe a patient with ulcers on his legs, involving late diagnosis of lepromatous leprosy. PMID:27828650

  10. Painful legs and moving toes syndrome

    Directory of Open Access Journals (Sweden)

    Qiu-ying Ma

    2015-10-01

    Full Text Available Painful legs and moving toes syndrome (PLMT is a rare movement disorder with low diagnostic rate, which is characterized by lower limb pain with involuntary movements of feet or toes. Etiology and pathogenesis of this disease is still unclear. Patients have different clinical manifestations, so the diagnosis is difficult. Treatment methods for PLMT are numerous, but so far the treatment of this disease is still a major challenge for clinicians. Further research is still needed to guide clinical work. DOI: 10.3969/j.issn.1672-6731.2015.10.013

  11. A Modified McQuiston model for evaluating efficiency of wet fin considering effect of condensate film moving on fin surface

    International Nuclear Information System (INIS)

    Xu Xiangguo; Xia Liang; Chan Mingyin; Deng Shiming

    2008-01-01

    A modified McQuiston model for evaluating the wet fin efficiency of cooling and dehumidification coils has been developed by modifying the existing popular McQuiston model and is reported in this paper. The condensate film moving on fin surfaces and its impacts on heat transfer have been taken into account in deriving the governing equation for fin temperature, and consequently, the enthalpy change of the moving condensate film has been included in the governing equation for fin temperature. The modified McQuiston model was validated by comparing its predictions with those using the McQuiston model under the same operating and boundary conditions. It is expected that the modified McQuiston model developed can be applied not only to the commonly seen air cooling and dehumidification but also to certain special operations such as industrial steam condensation

  12. The morphology of the cephalic lobes and anterior pectoral fins in six species of batoids.

    Science.gov (United States)

    Mulvany, Samantha; Motta, Philip J

    2013-09-01

    Many benthic batoids utilize their pectoral fins for both undulatory locomotion and feeding. Certain derived, pelagic species of batoids possess cephalic lobes, which evolved from the anterior pectoral fins. These species utilize the pectoral fins for oscillatory locomotion while the cephalic lobes are used for feeding. The goal of this article was to compare the morphology of the cephalic lobes and anterior pectoral fins in species that possess and lack cephalic lobes. The skeletal elements (radials) of the cephalic lobes more closely resembled the radials in the pectoral fin of undulatory species. Second moment of area (I), calculated from cephalic lobe radial cross sections, and the number of joints revealed greater flexibility and resistance to bending in multiple directions as compared to pectoral fin radials of oscillatory species. The cephalic lobe musculature was more complex than the anterior pectoral fin musculature, with an additional muscle on the dorsal side, with fiber angles running obliquely to the radials. In Rhinoptera bonasus, a muscle presumably used to help elevate the cephalic lobes is described. Electrosensory pores were found on the cephalic lobes (except Mobula japonica) and anterior pectoral fins of undulatory swimmers, but absent from the anterior pectoral fins of oscillatory swimmers. Pore distributions were fairly uniform except in R. bonasus, which had higher pore numbers at the edges of the cephalic lobes. Overall, the cephalic lobes are unique in their anatomy but are more similar to the anterior pectoral fins of undulatory swimmers, having more flexibility and maneuverability compared to pectoral fins of oscillatory swimmers. The maneuverable cephalic lobes taking on the role of feeding may have allowed the switch to oscillatory locomotion and hence, a more pelagic lifestyle. Copyright © 2013 Wiley Periodicals, Inc.

  13. The relationship between pectoral fin ray stiffness and swimming behavior in Labridae: insights into design, performance and ecology.

    Science.gov (United States)

    Aiello, Brett R; Hardy, Adam R; Cherian, Chery; Olsen, Aaron M; Ahn, Sihyun E; Hale, Melina E; Westneat, Mark W

    2018-01-09

    The functional capabilities of flexible, propulsive appendages are directly influenced by their mechanical properties. The fins of fishes have undergone extraordinary evolutionary diversification in structure and function, which raises questions of how fin mechanics relate to swimming behavior. In the fish family Labridae, pectoral fin swimming behavior ranges from rowing to flapping. Rowers are more maneuverable than flappers, but flappers generate greater thrust at high speeds and achieve greater mechanical efficiency at all speeds. Interspecific differences in hydrodynamic capability are largely dependent on fin kinematics and deformation, and are expected to correlate with fin stiffness. Here we examine fin ray stiffness in two closely related species that employ divergent swimming behaviors, the flapping Gomphosus varius and the rowing Halichoeres bivittatus To determine the spatial distribution of flexural stiffness across the fin, we performed three-point bending tests at the center of the proximal, middle and distal regions of four equally spaced fin rays. Pectoral fin ray flexural stiffness ranged from 0.0001 to 1.5109 µN m 2 , and the proximal regions of G. varius fin rays were nearly an order of magnitude stiffer than those of H. bivittatus In both species, fin ray flexural stiffness decreased exponentially along the proximodistal span of fin rays, and flexural stiffness decreased along the fin chord from the leading to the trailing edge. Furthermore, the proportion of fin area occupied by fin rays was significantly greater in G. varius than in H. bivittatus , suggesting that the proportion of fin ray to fin area contributes to differences in fin mechanics. © 2018. Published by The Company of Biologists Ltd.

  14. Restless Legs Syndrome After Single Low Dose Quetiapine Administration.

    Science.gov (United States)

    Soyata, Ahmet Z; Celebi, Fahri; Yargc, Lutfi I

    2016-01-01

    Restless legs syndrome is an underdiagnosed sensori-motor disorder and psychotropic drugs are one of the main secondary causes of the illness. The most common psychotropic agents that cause restless legs syndrome are antidepressants; however, antipsychotics have also been reported to induce restless legs syndrome. The prevalence, vulnerability factors and the underlying mechanism of antipsychotic-induced restless legs syndrome are unclear. A possible explanation is that dopaminergic blockade is the main precipitator of the syndrome. Quetiapine-induced restless legs syndrome is another point of interest because of its low binding to D2 receptors. We herein report the case of a restless legs syndrome that emerged after a single low dose quetiapine administration.

  15. Immediate Effect of Positioning Devices on Infant Leg Movement Characteristics.

    Science.gov (United States)

    Jiang, Crystal; de Armendi, Joyce T; Smith, Beth A

    2016-01-01

    To determine the immediate effects of constraining or encouraging positioning devices on leg movement of infants with typical development (TD) and at-risk for developmental delay (AR). Twenty-six infants (13 TD, 13 AR) were placed in the supine position, a jungle gym, or a car seat. Movement sensors on infants' ankles measured acceleration and angular velocity. We calculated the number of leg movements, peak acceleration, and peak rotational rate of each leg movement. A 2 (group) × 3 (condition) analysis of variance with repeated measures on condition tested for a group effect, a condition effect, and a group by condition interaction for leg movement quantity, average peak acceleration, and average peak rotation. Leg movement quantity and average peak acceleration were significantly lower for the car seat condition compared with the supine position or the gym. Positioning device use has an immediate effect on infant leg movement characteristics. Long-term effects remain unknown.

  16. 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.

  17. 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.

  18. Precision and accuracy of age estimates obtained from anal fin spines, dorsal fin spines, and sagittal otoliths for known-age largemouth bass

    Science.gov (United States)

    Klein, Zachary B.; Bonvechio, Timothy F.; Bowen, Bryant R.; Quist, Michael C.

    2017-01-01

    Sagittal otoliths are the preferred aging structure for Micropterus spp. (black basses) in North America because of the accurate and precise results produced. Typically, fisheries managers are hesitant to use lethal aging techniques (e.g., otoliths) to age rare species, trophy-size fish, or when sampling in small impoundments where populations are small. Therefore, we sought to evaluate the precision and accuracy of 2 non-lethal aging structures (i.e., anal fin spines, dorsal fin spines) in comparison to that of sagittal otoliths from known-age Micropterus salmoides (Largemouth Bass; n = 87) collected from the Ocmulgee Public Fishing Area, GA. Sagittal otoliths exhibited the highest concordance with true ages of all structures evaluated (coefficient of variation = 1.2; percent agreement = 91.9). Similarly, the low coefficient of variation (0.0) and high between-reader agreement (100%) indicate that age estimates obtained from sagittal otoliths were the most precise. Relatively high agreement between readers for anal fin spines (84%) and dorsal fin spines (81%) suggested the structures were relatively precise. However, age estimates from anal fin spines and dorsal fin spines exhibited low concordance with true ages. Although use of sagittal otoliths is a lethal technique, this method will likely remain the standard for aging Largemouth Bass and other similar black bass species.

  19. Nocturnal leg cramps in children: incidence and clinical characteristics.

    Science.gov (United States)

    Leung, A. K.; Wong, B. E.; Chan, P. Y.; Cho, H. Y.

    1999-01-01

    The records of 2527 healthy children seen in an ambulatory care clinic were evaluated for nocturnal leg cramps in the preceding 12 months, frequency and duration of the cramps, whether the cramps affected one leg or both legs at a time, whether there was associated muscle cramps in feet, whether the cramps occurred when the child was awake or asleep, and whether there was residual tenderness in the affected muscles. Nocturnal leg cramps were present in 185 children for an overall incidence of 7.3%. Leg cramps were noted only in children aged > or = 8 years. The incidence increased at 12 years and peaked at 16 to 18 years of age. A majority (81.6%) of the affected children had nocturnal leg cramps 1 to 4 times per year. The mean duration of episodes was 1.7 minutes. Leg cramps were unilateral in 98.9% of cases and the ipsilateral foot also was involved in 18.9% of cases. One hundred thirty-five (73%) children had leg cramps while asleep, and the remaining 23 (12.4%) children had leg cramps in either state. Fifty-seven (30.8%) children had residual tenderness in the affected muscles. The mean duration of residual tenderness was 33.2 minutes (range: 2 minutes-1 day). We conclude that nocturnal leg cramps are common in children aged > 12 years. A majority of the affected children have leg cramps 1 to 4 times per year. The cramps are usually unilateral and occur when the children are asleep. Normal duration of the leg cramp is < 2 minutes. Residual tenderness is present in approximately 30% of the affected children. Residual tenderness, if present, usually lasts for half an hour. PMID:10388258

  20. Six weeks' aerobic retraining after two weeks' immobilization restores leg lean mass and aerobic capacity but does not fully rehabilitate leg strenght in young and older men

    DEFF Research Database (Denmark)

    Vigelsø Hansen, Andreas; Gram, Martin; Wiuff, Caroline

    2015-01-01

    OBJECTIVE: To determine the effect of aerobic retraining as rehabilitation after short-term leg immobilization on leg strength, leg work capacity, leg lean mass, leg muscle fibre type composition and leg capillary supply, in young and older men. SUBJECTS AND DESIGN: Seventeen young (23 ± 1 years...... immobilization had marked effects on leg strength, and work capacity and 6 weeks' retraining was sufficient to increase, but not completely rehabilitate, muscle strength, and to rehabilitate aerobic work capacity and leg lean mass (in the young men)....

  1. An Ultralightweight and Living Legged Robot.

    Science.gov (United States)

    Vo Doan, Tat Thang; Tan, Melvin Y W; Bui, Xuan Hien; Sato, Hirotaka

    2018-02-01

    In this study, we describe the most ultralightweight living legged robot to date that makes it a strong candidate for a search and rescue mission. The robot is a living beetle with a wireless electronic backpack stimulator mounted on its thorax. Inheriting from the living insect, the robot employs a compliant body made of soft actuators, rigid exoskeletons, and flexure hinges. Such structure would allow the robot to easily adapt to any complex terrain due to the benefit of soft interface, self-balance, and self-adaptation of the insect without any complex controller. The antenna stimulation enables the robot to perform not only left/right turning but also backward walking and even cessation of walking. We were also able to grade the turning and backward walking speeds by changing the stimulation frequency. The power required to drive the robot is low as the power consumption of the antenna stimulation is in the order of hundreds of microwatts. In contrast to the traditional legged robots, this robot is of low cost, easy to construct, simple to control, and has ultralow power consumption.

  2. Restless legs syndrome in hemodialysis patients

    Directory of Open Access Journals (Sweden)

    Shahram Rafie

    2016-01-01

    Full Text Available Restless legs syndrome (RLS is a neurological disorder characterized by uncomfortable sensation of paresthesia in legs that subsequently causes involuntary and continuous movement of the lower limbs, especially at rest. Its prevalence in hemodialysis is more than that in the general population. Different risk factors have been suggested for RLS. We studied the prevalence and risk factors of RLS in 137 hemodialysis patients followed up at our center. The patients completed at least three months on dialysis and fulfilled four criteria for the diagnosis of RLS. We compared the patients with and without RLS, and the odds ratios (ORs were estimated by the logistic regression models. The prevalence of RLS was 36.5% in the study patients. Among the variables, diabetes was the only predicting factor for the development of RLS. The diabetic patients may be afflicted with RLS 2.25 times more than the non-diabetics. Women developed severe RLS 5.23 times more than men. Neurodegeneration, decrease in dopamine level, higher total oxidant status, and neuropathy in diabetic patients may explain the RLS symptoms.

  3. Compression Stockings for Treating Venous Leg Ulcers

    Directory of Open Access Journals (Sweden)

    J. P. Benigni

    2013-01-01

    Full Text Available Background. In order to treat venous leg ulcers, it is recommended to use high pressure compression (30–40 mmHg at the ankle. Compression stockings which are not operator dependant could be the best option because of their pressure control. However 30–40 mmHg compression stockings are often hard to put on. Putting two lower pressure compression stockings over each other could be a good therapeutic alternative. Objectives. To compare the in vitro pressures given by the manufacturers of 2 antiulcer kits with the in vivo interface pressures measured in healthy subjects and to evaluate the stiffness and friction indices from those kits based on the interface pressure in order to assess their clinical properties. Material and Methods. Using a Kikuhime pressure device, interface pressure was measured in 12 healthy subjects at the reference point B1. One stiffness index (Static Stiffness Index (SSI and a friction index have been calculated. Results. Mediven Ulcer kit gets the recommended pressures whereas Jobst’s Ulcer Care kit does not for treating a venous leg ulcer. Jobst’s Ulcer Care transmits entirely the pressure in relation to a friction index close to 1. Conclusion. This antiulcer kit study underlines that in vivo and in vitro pressures can be different (Jobst’s Ulcer Care kit and Mediven Ulcer kit. In order not to lose pressure, it is important to take into account the friction index when superimposing two stockings.

  4. Influence of Chimney Flow Pattern on Natural Convection Heat Transfer of Open Channel Finned Plates

    International Nuclear Information System (INIS)

    Hong, Seung-Hyun; Chung, Bum-Jin

    2015-01-01

    The enhancement of the efficiency and effectiveness of the passive cooling system, have long been the topic of those studies. In this study, we investigated the heat transfer enhancement of finned plates, especially the chimney effect appeared in finned plates. The fin not only enlarges the heat transfer area but also draws fresh fluid from the open side of the channel composed of the base plate and fins, which further enhances the cooling capability of finned plate – a chimney flow pattern. This study aims at investigating the influence of the chimney flow pattern on the natural convection heat transfer of the finned plate. To analyze the phenomenological study, both experimental and numerical analyses were performed. Numerical analysis was performed for the natural convection heat transfer of a finned plate in an open channel. In order to investigate the influence of the chimney flow pattern the heat transfer, several fin height were simulated and compared. The temperature profiles varied drastically depending on the values of the Prandtl number. As the Prandtl number increases, the thermal boundary layer reduces

  5. Influence of chimney width on the natural convection cooling of a vertical finned plate

    International Nuclear Information System (INIS)

    Moon, Je-Young; Heo, Jeong-Hwan; Chung, Bum-Jin

    2015-01-01

    Highlights: • Natural convection experiments for a finned plate in a chimney for RCCS application. • High Ra was achieved by using mass transfer experiments based on analogy concept. • Measured Nusselt numbers agreed with the other existing studies. • The chimney width is important due to bypass flow and internal circulation. • An empirical correlation was developed based upon the test results. - Abstract: We investigated natural convection heat transfer for a finned plate inside a chimney for application in reactor cavity cooling systems (RCCSs). To achieve a large Rayleigh number, the mass transfer rates were measured rather than the heat transfer rates, exploiting the analogy between heat and mass transfer systems. Experiments were carried out with systematically varied fin heights, fin spacings, chimney heights, and chimney widths, and for large Rayleigh numbers (of up to 2.91 × 10 7 ). The experimental results were consistent with the existing correlations, which were based on numerical models. Larger heat transfer rates were observed for larger fin heights and smaller fin spacings due to the increased heat transfer area. As the distance between walls and the fin tip increased, the heat transfer rate decreased, until the chimney effect was no longer observed, where the plume circulated within the duct. An empirical correlation was derived using the test results. The study concludes that the optimizations of chimney parameters as well as fin parameters are required for RCCS applications.

  6. 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.

  7. 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

  8. 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.

  9. Failure analysis and life prediction of a large, complex plate fin heat exchanger

    CSIR Research Space (South Africa)

    Carter, P

    1996-03-01

    Full Text Available Failure analysis and life prediction of a large, complex fin plate heat exchanger required metallurgical analysis, at the beginning of 1993, inter-stream leaks were found in two aluminium plate fin heat exchangers in parallel operation at a...

  10. Effect of swim-training on caudal fin development in zebrafish larvae

    NARCIS (Netherlands)

    Fiaz, Ansa

    2014-01-01

    Genome-wide microarray analysis of the effects of swim-training on caudal fin development in zebrafish larvae. Zebrafish were subjected to swim-training from 5 days post fertilization (dpf) until 10 dpf. Subsequently, we performed a genome-wide microarray analysis on the caudal fins of control and

  11. Performance of double –pass solar collector with CPC and fins for heat transfer enhancement

    International Nuclear Information System (INIS)

    Alfegi, Ebrahim M A; Abosbaia, Alhadi A S; Mezughi, Khaled M A; Sopian, Kamaruzzaman

    2013-01-01

    The temperature of photovoltaic modules increases when it absorbs solar radiation, causing a decrease in efficiency. This undesirable effect can be partially avoided by applying a heat recovery unit with fluid circulation (air or water) with the photovoltaic module. Such unit is called photovoltaic / thermal collector (pv/t) or hybrid (pv/t). In this unit, photovoltaic cells were pasted directly on the flat plate absorber. An experimental study of a solar air heater with photovoltaic cell located at the absorber with fins and compound parabolic collector for heat transfer enhancement and increasing the number of reflection on the cells have been conducted. The performance of the photovoltaic, thermal, and combined pv/t collector over range of operating conditions and the results was discussed. Results at solar irradiance of 500 W/m 2 show that the combined pv/t efficiency is increasing from 37.28 % to 81.41 % at mass flow rates various from 0.029 to 0.436 kg/s.

  12. Performance of double -pass solar collector with CPC and fins for heat transfer enhancement

    Science.gov (United States)

    Alfegi, Ebrahim M. A.; Abosbaia, Alhadi A. S.; Mezughi, Khaled M. A.; Sopian, Kamaruzzaman

    2013-06-01

    The temperature of photovoltaic modules increases when it absorbs solar radiation, causing a decrease in efficiency. This undesirable effect can be partially avoided by applying a heat recovery unit with fluid circulation (air or water) with the photovoltaic module. Such unit is called photovoltaic / thermal collector (pv/t) or hybrid (pv/t). In this unit, photovoltaic cells were pasted directly on the flat plate absorber. An experimental study of a solar air heater with photovoltaic cell located at the absorber with fins and compound parabolic collector for heat transfer enhancement and increasing the number of reflection on the cells have been conducted. The performance of the photovoltaic, thermal, and combined pv/t collector over range of operating conditions and the results was discussed. Results at solar irradiance of 500 W/m2 show that the combined pv/t efficiency is increasing from 37.28 % to 81.41 % at mass flow rates various from 0.029 to 0.436 kg/s.

  13. Leg Rejuvenation: A Combination Approach: A Review and Our Experience.

    Science.gov (United States)

    Weiss, Margaret; Mahoney, Anne M; Gold, Michael; Lawrence, Naomi

    2016-05-01

    Patients increasingly seek to enhance the appearance of their legs. Elimination of unwanted leg veins, reduction of epidermal photo-aging changes such as solar lentigines and keratoses, tightening of skin laxity and reduction of adipose tissue are among the most commonly requested goals. Many patients require a combination approach to address their concerns. It is important for dermatologists to be aware of the multitude of procedures that can be performed, often in combination, to rejuvenate the leg. The purpose of this review article was to discuss procedures for improving the appearance of the leg and to share the authors experience, especially in the combination approach to leg rejuvenation. A literature search was performed to investigate cosmetic procedures being performed on the leg, with an emphasis on controlled or randomized studies. In addition, the authors contributed their personal experience. Our discussion of the literature review highlights the treatments for leg veins, unwanted fat, cellulite, and photodamage of the legs that are most supported in peer-reviewed publications. A synergistic, combination approach to leg rejuvenation works best. This includes the use of injectable agents, energy-based devices, and more invasive surgical procedures.

  14. Fanning friction (f and colburn (j factors of a louvered fin and flat tube compact heat exchanger

    Directory of Open Access Journals (Sweden)

    Karthik Pooranachandran

    2017-01-01

    Full Text Available In the present study, the heat transfer and pressure drop characteristics of air over the louvered fins in a compact heat exchanger, used as a radiator in the automobiles have been experimentally investigated. The experiments were conducted at various flow rates of air and the results showed a decrease in goodness factor of 22.7% with respect to increase in Reynolds number from 231 to 495. The experimental results were compared with the CFD results and the ‘f’ and ‘j’ factors from the CFD analysis are in good agreement with the experimental data. Also, the experimental ‘f’ and ‘j’ factors were compared with the predicted values from the available correlations in the literature for the louvered fin and tube compact heat exchangers. The large deviation of the predicted results revealed that the correlations are not reliable for the design of the compact heat exchanger. Hence, the CFD analysis is more advantageous for the optimal design of compact heat exchanger, which also reduces the experimentation time and cost.

  15. 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

  16. HEAT EXCHANGE AND AERODYNAMICS OF THE COMBINED TUBING BUNDLES WITH CROSS INCLINED FINS

    Directory of Open Access Journals (Sweden)

    Knyazyuk V. I

    2013-04-01

    Full Text Available The paper presents results of experimental research and analyses air-side thermal performance of combined tube bundles with cross inclined fins. The empirical correlations for heat transfer and flow friction of tubes with inclined fins at different orientation finned tubes relatively of air flow are presented. The errors of thermal and aerodynamic tests are 3-5% and 9.2%, respectively. The proposed correlations describe an experimental data with a coefficient of determination about 0.979-0.998. The impact of tubes arrangement in a bundle on energy performance of heat exchanger were analyzed using complete and local heat modeling methods at a stationary heat flux. Experimental research indicates that efficiency of inclined fins can be calculated by using the equation for cross rectangular fins with average deviation of ±5 %.

  17. 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.

  18. 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)

  19. Chemical milling of zircaloy tubing to produce integral OD spiral finned tubes. AWBA development program

    Science.gov (United States)

    Horwood, W. A.

    1982-02-01

    A detailed process description is provided for producing integral spiral fins on the outside surface of Zircaloy nuclear fuel cladding tubes by masking with pressure sensitive tape strips and then chemical milling (pickling) the tube wall between the tape strips to leave the fins in relief. Fins up to 0.020 inch high by 0.05 to 0.12 inch wide were consistently produced on tubes having wall thickness of 0.008 inch or greater after fin pickling. Wall thickness uniformity was excellent. Information is provided on tube surface preparation to maximize tape mask adhesion time during pickling, acid chemistry control to prevent local tube wall thinning near the fin, and pickling techniques to promote uniform material removal. Simple fixture designs are described for quickly and conveniently applying the tape strips to the tube wall in an accurate spiral.

  20. Summertime blues? A re-examination of the seasonality of web searches for restless legs and leg cramps.

    Science.gov (United States)

    O'Keeffe, Shaun T

    2017-09-01

    Studies that examined Internet searches for restless legs and leg cramps have found a strong seasonal effect with peaks in summer and troughs in winter months. The present study used an econometric approach to examine the seasonality of such searches in greater detail. Monthly relative search volumes for 'restless legs' and 'leg cramps' from 2004 to March 2017 in the United Kingdom (UK) and Australia were obtained from Google Trends. Average percentage change from winter to summer months was examined. The TRAMO-SEATS procedure from the DEMETRA statistical software was used to decompose the data into trend, seasonal and noise components and to determine whether a combined seasonality test was positive. There were substantial percentage increases in Google Trends searches between winter and summer months regarding restless legs in the UK (median increase 46%) and Australia (33%) and regarding leg cramps in the UK (95%) and Australia (50%). However, the combined seasonality test was positive only for leg cramps and not for restless legs in both countries: although there was significant stable seasonality in restless legs searches, this was outweighed by substantial moving seasonality and noise components. Examination of average percentage increase in search volume from winter to summer exaggerates the degree of seasonality. Seasonal effects for restless legs searches are non-significant when the trend and noise components of the data are considered, although this does not exclude a clinical significance for the identified stable seasonality. Significant seasonality, with a summer peak, is present for leg cramps searches and suggests an increase in the incidence or severity of leg cramps in summer. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. 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.

  2. Numerical study of mixed convection heat transfer of various fin arrangements in a horizontal channel

    Directory of Open Access Journals (Sweden)

    Mojtaba Mokhtari

    2017-06-01

    Full Text Available The mixed convection of a three-dimensional square duct with various arrangements of fins in both laminar and turbulent flow is numerically characterized and studied. This study focuses on the ability of fin arrangements to enhance a heat transfer while flow is incompressible and the fluid is air. In our models, the lower duct wall is defined with a constant heat flux condition while the two side walls and upper wall are insulated. The finite volume method with the SIMPLE (Semi Implicit Method for Pressure Linked Equations algorithm is used for handling the pressure–velocity coupling. The numerical results are validated with experimental data and show good agreement. The computations confirm that fin arrangement significantly changes the temperature distribution and cooling performance of the fins. This study focuses on the new arrangements of the fins that are not presented in previous studies. These arrangements have 3 Models with two angles (30 and 45°. According to the results, heat transfer highly improves (approximately 40–50% in the laminar flow stream and 15–20% in turbulent flow in comparison to base plate heat transfer as the simple fin arrangement is replaced by inclined fins. Moreover, the influence of limited heat flux on temperature distribution is extensively investigated. It is notable that the temperature of fins significantly reduces as the best arrangement of the fins is presented in the air flow stream. Therefore, an enhanced cooling zone occurs when the fin arrangement is adjusted according to the location of the source of the heat flux on the base plate.

  3. 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

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

    Science.gov (United States)

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

    2008-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Dong Keun; Lee, Kwan Soo [Hanyang Univ., Seoul (Korea, Republic of)

    2003-07-01

    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.

  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. Gabapentin Enacarbil: Pharmacotherapy of Restless Legs Syndrome

    Directory of Open Access Journals (Sweden)

    Ruth Jones

    2010-01-01

    Full Text Available Restless Legs Syndrome (RLS is a prevalent sleep-associated movement disorder greatly affecting patients’ quality of life (QoL. Several drugs can be used to control this condition although the first-line dopamine agents often cause adverse effects. Non-dopaminergic drugs such as oral gabapentin (GBP have been more recently advocated. Despite ameliorating RLS symptoms, GBP's pharmacokinetic limitations restrict its overall effectiveness. A novel specifically designed prodrug, gabapentin enacarbil (GE, has demonstrated successful RLS alleviation with a superior pharmacokinetic profile. This review aims to examine the efficacy and tolerability of both GBP and GE as pharmacotherapy for RLS. Despite some heterogeneity and limitations across research methodologies, GE appears to be a potential RLS therapy superior to GBP and other dopaminergic agents.

  8. [Lipedema of the leg associated with dermatomyositis].

    Science.gov (United States)

    Ignjatović, M; Cerović, S

    1999-01-01

    Lipedema represents a form of lipodistrophy, which consists of abnormal accumulation of fat in subcutaneous tissue of the lower limbs with consecutive development of lymphostasis and lymphedema. The aim of this article was to review one clear case of lower limbs lipedema, of unusual occurrence and appearance, which was associated with dermatomyositis. A moderately manifested lipedema in 8 years old little girl was reported with its expressive segmental distribution to upper and lower legs, without significant increase in its size during last 10 years and without signs of lymphostasis. The hereditary influence was not confirmed. Histological examination of lipedematous tissue revealed significant presentation of immune component of the disease. According to the available literature, association between lipedema and dermatomyositis, lower limbs lipedema with segmental distribution as noticed above and its appearance as a consequence of corticosteroid therapy have not yet been published.

  9. [Pseudo-radicular referred leg pain].

    Science.gov (United States)

    von Heymann, W

    2015-12-01

    Pseudo-radicular leg pain as initially described by Bruegger more than 55 years ago was at that time a genius explanation for so many non-radicular pain syndromes that needed not any kind of surgical intervention but in first line a manual treatment or a treatment by therapeutic local anesthetics. Today we describe this pain as a "referred pain" originating from other anatomic structures that may occur during the development of chronic pain. Nevertheless this pain is found in many patients and it still seems to be a big problem for many physicians and surgeons. Imaging does not help either. The history and the clinical symptoms, the examinations, the chain reactions in the motor system as well as the treatment options from the point of view of manual medicine are described.

  10. Endovenous management of venous leg ulcers.

    Science.gov (United States)

    Raju, Seshadri; Kirk, Orla K; Jones, Tamekia L

    2013-04-01

    Compression is the current "standard" in the treatment of venous leg ulcers, and corrective surgery is ancillary. The emergence of safe and effective minimally invasive corrective techniques prompts a reappraisal of this paradigm. Among 192 consecutive limbs with venous leg ulcers, 189 were treated by (1) endovenous laser ablation (n = 30), (2) iliac vein stent placement (n = 89), or (3) both (n = 69). Residual deep reflux was not treated. No specialized wound care was used, and 38% of patients did not use stockings. Outcome measures were time to heal the ulcer and cumulative long-term healing. Sixty percent of the limbs were post-thrombotic. The median reflux segment score was 3 (range, 0-7). Thirty-seven percent had deep axial reflux. Median intravascular ultrasound-detected stenosis was 70% (range, 0%-100%) in stented patients. Sensitivity of venography to iliac vein obstruction was 52%. Postprocedural mortality was 0%, and 2% had deep venous thrombosis (ulcers approximately ≤1 inch in diameter had healed. Larger ulcers were slower in healing (P pressure). However, long-term ulcer healing was inferior in limbs with reflux segment score of ≥3 (P ulcers in this consecutive series achieved long-term healing with the described minimally invasive algorithm. Uncorrected residual reflux was not an impediment to ulcer healing. Ulcers sized ≤1 inch required no specialized or prolonged wound care. Compression was not necessary to achieve or maintain healing after interventional correction. Copyright © 2013 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

  11. Restless legs syndrome in patients on hemodialysis

    Directory of Open Access Journals (Sweden)

    Saleh Mohammad Yaser Salman

    2011-01-01

    Full Text Available Restless legs syndrome (RLS is common among dialysis patients, with a reported prevalence of 6-60%. The prevalence of RLS in Syrian patients on hemodialysis (HD is not known. The purpose of this study is to determine the prevalence of RLS in patients on regular HD, and to find the possible correlation between the presence of RLS and demographic, clinical, and biochemical factors. One hundred and twenty-three patients (male/female = 70/53, mean age = 41.95 ± 15.11 years on HD therapy at the Aleppo University Hospital were enrolled into the study. RLS was diagnosed based on criteria established by the International Restless Legs Syn-drome Study Group (IRLSSG. Data procured were compared between patients with and without RLS. Applying the IRLSSG criteria for the diagnosis, RLS was seen in 20.3% of the study pa-tients. No significant difference in age, gender, and intake of nicotine and caffeine was found between patients with and without the RLS. Similarly, there was no difference between the two groups in the duration of end-stage renal disease (ESRD, the period of dialysis dependence, dialysis adequacy, urea and creatinine levels, and the presence of anemia. The co-morbidities and the use of drugs also did not differ in the two groups. Our study suggests that the high prevalence of RLS among patients on HD requires careful attention and correct diagnosis can lead to better therapy and better quality of life. The pathogenesis of RLS is not clear and further studies are required to identify any possible cause as well as to discover the impact of this syndrome on sleep, quality of life, and possibly other complications such as cardiovasculare disease.

  12. ODYSSEUS autonomous walking robot: The leg/arm design

    Science.gov (United States)

    Bourbakis, N. G.; Maas, M.; Tascillo, A.; Vandewinckel, C.

    1994-01-01

    ODYSSEUS is an autonomous walking robot, which makes use of three wheels and three legs for its movement in the free navigation space. More specifically, it makes use of its autonomous wheels to move around in an environment where the surface is smooth and not uneven. However, in the case that there are small height obstacles, stairs, or small height unevenness in the navigation environment, the robot makes use of both wheels and legs to travel efficiently. In this paper we present the detailed hardware design and the simulated behavior of the extended leg/arm part of the robot, since it plays a very significant role in the robot actions (movements, selection of objects, etc.). In particular, the leg/arm consists of three major parts: The first part is a pipe attached to the robot base with a flexible 3-D joint. This pipe has a rotated bar as an extended part, which terminates in a 3-D flexible joint. The second part of the leg/arm is also a pipe similar to the first. The extended bar of the second part ends at a 2-D joint. The last part of the leg/arm is a clip-hand. It is used for selecting several small weight and size objects, and when it is in a 'closed' mode, it is used as a supporting part of the robot leg. The entire leg/arm part is controlled and synchronized by a microcontroller (68CH11) attached to the robot base.

  13. Impact of Restless Legs Syndrome on Cardiovascular Autonomic Control.

    Science.gov (United States)

    Bertisch, Suzanne M; Muresan, Cristen; Schoerning, Laura; Winkelman, John W; Taylor, J Andrew

    2016-03-01

    To examine whether patients with restless legs syndrome demonstrate specific alterations in cardiovascular autonomic control. Patients with moderate-severe restless legs syndrome (n = 20, 80% female) and controls (n = 20) matched for age, sex, body mass index, and free of hypertension and cardiovascular disease were enrolled. We assessed cardiovagal baroreflex gain via the modified Oxford technique, sympathetically mediated vascular responses to isometric exercise to fatigue, bradycardiac response to Valsalva maneuver, and respiratory sinus arrhythmia during paced breathing. Standard electrocardiography, beat-by-beat arterial pressure, respiration, and popliteal blood flow velocity were recorded continuously. Resting blood pressure and heart rate were similar between groups. However, baroreflex gain averaged 14.3 ± 1.4 msec/mm Hg in restless legs syndrome and was lower than in controls (22.6 ± 3.5 msec/mm Hg, P = 0.04). Hemodynamic responses to isometric exercise were similar between groups, though participants with restless legs syndrome had lower leg blood flow (P leg vascular resistance (P restless legs syndrome demonstrate compromised cardiovagal control, specific to the arterial baroreflex, with greater peripheral vascular resistance, potentially due to heightened sympathetic outflow. These autonomic alterations may directly relate to the higher prevalence of cardiovascular disease in restless legs syndrome. © 2016 Associated Professional Sleep Societies, LLC.

  14. Criteria in diagnosing nocturnal leg cramps : A systematic review

    NARCIS (Netherlands)

    Hallegraeff, Joannes; de Greef, Mathieu; Krijnen, Wim; van der Schans, Cees

    2017-01-01

    Background: Up to 33% of the general population over 50 years of age are affected by nocturnal leg cramps. Currently there are no generally accepted clinical characteristics, which identify nocturnal leg cramps. This study aims to identify these clinical characteristics and to differentiate between

  15. How Can I Relieve My Pregnancy Leg Cramps?

    Science.gov (United States)

    ... Español How Can I Relieve My Pregnancy Leg Cramps? KidsHealth / For Parents / How Can I Relieve My Pregnancy Leg Cramps? Print Now that I'm in my third trimester, I keep getting these painful cramps in my calves. Sometimes they even wake me ...

  16. Ubx regulates differential enlargement and diversification of insect hind legs.

    Directory of Open Access Journals (Sweden)

    Najmus Mahfooz

    2007-09-01

    Full Text Available Differential enlargement of hind (T3 legs represents one of the hallmarks of insect evolution. However, the actual mechanism(s responsible are yet to be determined. To address this issue, we have now studied the molecular basis of T3 leg enlargement in Oncopeltus fasciatus (milkweed bug and Acheta domesticus (house cricket. In Oncopeltus, the T3 tibia displays a moderate increase in size, whereas in Acheta, the T3 femur, tibia, and tarsus are all greatly enlarged. Here, we show that the hox gene Ultrabithorax (Ubx is expressed in the enlarged segments of hind legs. Furthermore, we demonstrate that depletion of Ubx during embryogenesis has a primary effect in T3 legs and causes shortening of leg segments that are enlarged in a wild type. This result shows that Ubx is regulating the differential growth and enlargement of T3 legs in both Oncopeltus and Acheta. The emerging view suggests that Ubx was co-opted for a novel role in regulating leg growth and that the transcriptional modification of its expression may be a universal mechanism for the evolutionary diversification of insect hind legs.

  17. Recurrent Metachronous Acute Compartment Syndrome in the Legs ...

    African Journals Online (AJOL)

    METHODS: A seven-year-old boy presented with four separate episodes of acute compartment syndrome of the legs within three years. The recurrent nature of the illness prompted detail review of the records of the child. RESULTS: There was involvement of each leg twice between the ages of three and seven years ...

  18. In-patient management of leg ulcers | Ohanaka | East African ...

    African Journals Online (AJOL)

    Objective: To review in-patient management of leg ulcers and to compare our experiences with those from other similar centres. Design: A retrospective study. Setting: University of Benin Teaching Hospital, Nigeria. Patients: Forty five patients hospitalisad with leg ulcers. Results: There were 27 male and 18 females (MF 3:2) ...

  19. Common Leg Aliment Of Poultry In Plateau State, Nigeria | Ogbe ...

    African Journals Online (AJOL)

    A study was carried out to investigate the occurrence and causes of leg ailment in poultrythrough questionnaire survey and farm visitation. Post mortem and laboratory examination were also conducted. The results showed that different species of poultry were affected with varous types of leg ailments; out of which local ...

  20. Leg length, sitting height and postmenopausal breast cancer risk

    DEFF Research Database (Denmark)

    Mellemkjær, L; Christensen, J; Frederiksen, K

    2012-01-01

    Tallness has consistently been associated with an increased risk of breast cancer. We investigated the association further by decomposing height into leg length and sitting height.......Tallness has consistently been associated with an increased risk of breast cancer. We investigated the association further by decomposing height into leg length and sitting height....

  1. Leg ulcers: a review of their impact on daily life.

    NARCIS (Netherlands)

    Persoon, A.; Heinen, M.M.; Vleuten, C.J.M. van der; Rooij, M.J.M. de; Kerkhof, P.C.M. van de; Achterberg, T. van

    2004-01-01

    BACKGROUND: Current nursing care for leg ulcer patients often focuses on wound care and providing compression therapy. Nurses perceive leg ulcer patients as 'under-served' with regard to problems patients experience in daily life. An overview of patient problems is a first and essential step in the

  2. The recalcitrant venous leg ulcer - A never ending story?

    NARCIS (Netherlands)

    S.W.I. Reeder (Suzan); M.B. Maessen-Visch (Birgitte); S.I. Langendoen; K.P. de Roos; H.A.M. Neumann (Martino)

    2013-01-01

    textabstractIntroduction: In general, four particular causes of recalcitrant venous leg ulcers may be distinguished. These are foot pump insufficiency, chronic venous compartment syndrome and non-re-canalized popliteal vein thrombosis. The fourth cause of recalcitrant venous leg ulcers is

  3. Vibration transmission characteristics of the legs of freely standing honeybees

    DEFF Research Database (Denmark)

    Rohrseitz, Kristin; Kilpinen, Ole

    1997-01-01

    The leg vibrations of honeybees standing on a vibrating substrate were measured with laser Doppler vibrometry, both in freely standing bees and in bees attached to a holder. In both cases, no resonances were found. In the fixed bee preparation, the legs moved with approximately the same amplitude...

  4. A Brief Survey Paper on Multi-Legged Robots

    Directory of Open Access Journals (Sweden)

    Mohammad Behmanesh

    2015-03-01

    Full Text Available This paper presents a brief survey on multi-legged robots and their applications in agriculture such as for harvesting. Multi-legged robots have the benefit of more flexibility and adapt to different rough terrain in a better way. They also have very important applications in fulfilling the dangerous tasks such as mine detecting.

  5. Ubx Regulates Differential Enlargement and Diversification of Insect Hind Legs

    Science.gov (United States)

    Mahfooz, Najmus; Turchyn, Nataliya; Mihajlovic, Michelle; Hrycaj, Steven; Popadić, Aleksandar

    2007-01-01

    Differential enlargement of hind (T3) legs represents one of the hallmarks of insect evolution. However, the actual mechanism(s) responsible are yet to be determined. To address this issue, we have now studied the molecular basis of T3 leg enlargement in Oncopeltus fasciatus (milkweed bug) and Acheta domesticus (house cricket). In Oncopeltus, the T3 tibia displays a moderate increase in size, whereas in Acheta, the T3 femur, tibia, and tarsus are all greatly enlarged. Here, we show that the hox gene Ultrabithorax (Ubx) is expressed in the enlarged segments of hind legs. Furthermore, we demonstrate that depletion of Ubx during embryogenesis has a primary effect in T3 legs and causes shortening of leg segments that are enlarged in a wild type. This result shows that Ubx is regulating the differential growth and enlargement of T3 legs in both Oncopeltus and Acheta. The emerging view suggests that Ubx was co-opted for a novel role in regulating leg growth and that the transcriptional modification of its expression may be a universal mechanism for the evolutionary diversification of insect hind legs. PMID:17848997

  6. Secondary hyperparathyroidism: Uncommon cause of a leg ulcer

    NARCIS (Netherlands)

    van Rijssen, L. B.; Brenninkmeijer, E. E. A.; Nieveen van Dijkum, E. J. M.

    2012-01-01

    Most leg ulcers are vascular based. Only if vascular therapy fails other causes are considered. We report the case of a female with incapacitating leg ulcers caused by a rare condition which was only diagnosed after failing treatment. PRESENTATION OF CASE: The female had an extensive previous

  7. Diurnal variations in lower leg subcutaneous blood flow rate in patients with chronic venous leg ulcers

    DEFF Research Database (Denmark)

    Sindrup, J H; Kastrup, J; Kristensen, J K

    1991-01-01

    The blood flow rate in subcutaneous adipose tissue was measured on the lower legs of 11 patients with chronic lower-leg venous insufficiency and ulceration and in eight age-matched control subjects for 12-20 h, under ambulatory conditions, using the 133Xe wash-out technique with portable Cadmium...... telluride (CdTe(Cl)) detectors. In both groups, the change from an upright to a supine position at the beginning of the night period elicited an instantaneous increment in the blood flow rate of 30-40% with a decrease in the central and local postural sympathetic vasoconstrictor activity. After...... approximately 1 h of sleep, a considerable increase in blood flow rate was seen in both patient and control groups which persisted for nearly 100 min. In the patient group, the mean increase was 137% compared to a mean increase of 68% in the control group (P less than 0.01). The blood flow then returned...

  8. Short-interval leg movements during sleep entail greater cardiac activation than periodic leg movements during sleep in restless legs syndrome patients.

    Science.gov (United States)

    Ferri, Raffaele; Rundo, Francesco; Silvani, Alessandro; Zucconi, Marco; Aricò, Debora; Bruni, Oliviero; Lanuzza, Bartolo; Ferini-Strambi, Luigi; Manconi, Mauro

    2017-10-01

    Periodic leg movements during sleep (PLMS) are sequences of ≥4 motor events with intermovement intervals (IMI) of 10-90 s. PLMS are a supportive diagnostic criterion for restless legs syndrome (RLS) and entail cardiac activation, particularly when associated with arousal. RLS patients also over-express short-interval leg movements during sleep (SILMS), which have IMI leg movements. We found that the duration of the R-R interval decrease with SILMS doublets was significantly longer than that with PLMS, whereas the maximal decrease in R-R interval was similar. Scoring SILMS in RLS patients may therefore be relevant from a cardiac autonomic perspective. © 2017 European Sleep Research Society.

  9. Laboratory on Legs: An Architecture for Adjustable Morphology with Legged Robots

    Science.gov (United States)

    2012-04-01

    evenly throughout the body, all mounted on the waterjet cut frame. Through the use of a USB bus as the common communication method within the robot...according to the overarching “spring assisted actuation” hypothesis just described. The body of Canid is similar to XRL, built from waterjet cut aluminum...on cheap, relatively fast turn-around water jet cut frame components and compliant leg and spine materials offers some useful lessons in effective

  10. Relationship between Leg Mass, Leg Composition and Foot Velocity on Kicking Accuracy in Australian Football

    Directory of Open Access Journals (Sweden)

    Nicolas H. Hart, Jodie L. Cochrane, Tania Spiteri, Sophia Nimphius, Robert U. Newton

    2016-06-01

    Full Text Available Kicking a ball accurately over a desired distance to an intended target is arguably the most important skill to acquire in Australian Football. Therefore, understanding the potential mechanisms which underpin kicking accuracy is warranted. The aim of this study was to examine the relationship between leg mass, leg composition and foot velocity on kicking accuracy in Australian Football. Thirty-one Australian Footballers (n = 31; age: 22.1 ± 2.8 years; height: 1.81 ± 0.07 m; weight: 85.1 ± 13.0 kg; BMI: 25.9 ± 3.2 each performed ten drop punt kicks over twenty metres to a player target. Athletes were separated into accurate (n = 15 and inaccurate (n = 16 kicking groups. Leg mass characteristics were assessed using whole body DXA scans. Foot velocity was determined using a ten-camera optoelectronic, three-dimensional motion capture system. Interactions between leg mass and foot velocity evident within accurate kickers only (r = -0.670 to -0.701. Relative lean mass was positively correlated with kicking accuracy (r = 0.631, while no relationship between foot velocity and kicking accuracy was evident in isolation (r = -0.047 to -0.083. Given the evident importance of lean mass, and its interaction with foot velocity for accurate kickers; future research should explore speed-accuracy, impulse-variability, limb co-ordination and foot-ball interaction constructs in kicking using controlled with-in subject studies to examine the effects of resistance training and skill acquisition programs on the development of kicking accuracy.

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

    Directory of Open Access Journals (Sweden)

    Kathleen M. Dudzinski

    2017-02-01

    Full Text Available 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.

  13. Dynamic stiffness testing-based flutter analysis of a fin with an actuator

    Directory of Open Access Journals (Sweden)

    Zhang Renjia

    2015-10-01

    Full Text Available Engineering-oriented modeling and synthesized modeling of the fin-actuator system of a missile fin are introduced, including mathematical modeling of the fin, motor and multi-stage gear reducer. The fin-actuator model is verified using dynamic stiffness testing. Good agreement is achieved between the test and theoretical results. The parameter-variable analysis indicates that the inertia of the motor rotor, reduction ratio of the reducer, connection stiffness and damping between the actuator and fin shaft have significant impacts on the dynamic stiffness characteristics. In flutter analysis, test data are directly used in the frequency domain method and indirectly used in the time domain method through the updated fin-actuator model. The two methods play different roles in engineering applications but are of equal importance. The results indicate that dynamic stiffness and constant stiffness treatments may lead to completely different flutter characteristics. Attention should be paid to the design of the fin-actuator system of a missile.

  14. 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.

  15. 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.

  16. 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.

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

    Science.gov (United States)

    Chen, Chien-Hung; Wang, Chi-Chuan

    2015-11-01

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

  18. An External Condensation Heat Transfer Experiment for a Vertical Finned Tube

    International Nuclear Information System (INIS)

    Jang, Yeong Jun; Choi, Dong Jae; Lee, Yeon Gun; Kim, Sin

    2016-01-01

    The Passive Containment Cooling System (PCCS) that will be introduced in the next generation Korean nuclear power plant guarantee the safety of the nuclear power to utilize the condensation heat transfer phenomenon. The condensation heat transfer phenomenon plays a key role in the event of the loss of coolant accident (LOCA) or main steam line break (MSLB) in suppressing the pressurization of the containment. Therefore, the heat capacity of the PCCS is an important factor. This study focused to investigate the condensation heat transfer on a vertical finned tube for increase of the heat capacity by the fins under natural convection conditions. The 13 fins are installed along the tube height, uniformly. Experimental results show that the condensation HTR reduces with an increase of the noncondensable gas mass fraction because the noncondensable gas acts as a resistance during the condensation phenomena. The fin for the increment of the effective heat transfer area affects the condensation HTR. The fin plays a positive role due to the increment of the effective heat transfer area. However, the condensate decreases the condensation HTR. Especially, a retention area of the condensate is the one of the main parameter for the HTR of the disc type finned tube. In a view of the applicability to PCCS, for the single finned tube, HTR is higher than the bare tube, though the ratio of the HTR is the smaller than the ratio of the area.

  19. 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.

  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. 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.

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

    Directory of Open Access Journals (Sweden)

    Ningyu Li

    2016-01-01

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

  3. 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.

  4. Adaptive leg coordination with a biologically inspired neurocontroller

    Science.gov (United States)

    Braught, Grant; Thomopoulos, Stelios C.

    1996-10-01

    Natural selection is responsible for the creation of robust and adaptive control systems. Nature's control systems are created only from primitive building blocks. Using insect neurophysiology as a guide, a neural architecture for leg coordination in a hexapod robot has been developed. Reflex chains and sensory feedback mechanisms from various insects and crustacea form the basis of a pattern generator for intra-leg coordination. The pattern generator contains neural oscillators which learn from sensory feedback to produce stepping patterns. Using sensory feedback as the source of learning information allows the pattern generator to adapt to changes in the leg dynamics due to internal or external causes. A coupling between six of the single leg pattern generators is used to produce the inter-leg coordination necessary to establish stable gaits.

  5. A survey of bio-inspired compliant legged robot designs

    International Nuclear Information System (INIS)

    Zhou Xiaodong; Bi Shusheng

    2012-01-01

    The roles of biological springs in vertebrate animals and their implementations in compliant legged robots offer significant advantages over the rigid legged ones in certain types of scenarios. A large number of robotics institutes have been attempting to work in conjunction with biologists and incorporated these principles into the design of biologically inspired robots. The motivation of this review is to investigate the most published compliant legged robots and categorize them according to the types of compliant elements adopted in their mechanical structures. Based on the typical robots investigated, the trade-off between each category is summarized. In addition, the most significant performances of these robots are compared quantitatively, and multiple available solutions for the future compliant legged robot design are suggested. Finally, the design challenges for compliant legged robots are analysed. This review will provide useful guidance for robotic designers in creating new designs by inheriting the virtues of those successful robots according to the specific tasks. (topical review)

  6. Effects of gabapentin enacarbil on restless legs syndrome and leg pain in dementia with Lewy bodies.

    Science.gov (United States)

    Fujishiro, Hiroshige

    2014-06-01

    Restless legs syndrome (RLS) is a common neurological disorder. Dementia with Lewy bodies (DLB) is the second most common form of neurodegenerative dementia after Alzheimer's disease. Both RLS and DLB can be effectively treated by dopaminergic medications, suggesting the role of dopamine dysfunction in the pathogenesis of both diseases. Here, I report on a Japanese woman with probable DLB and RLS who was treated with gabapentin enacarbil, a non-dopaminergic agent. Because a dopamine agonist, a first-line therapy for moderate to severe RLS, caused the occurrence of metamorphopsia, an alternative treatment of gabapentin enacarbil was used; this treatment improved the patient's RLS without worsening her psychiatric symptoms. An alternative treatment is desirable for DLB patients with RLS because they often experience intolerable side-effects with a dopamine agonist, especially visual hallucinations. Administering gabapentin enacarbil also improved the continuous leg pain that occurred in conjunction with the development of RLS. Although the neurobiological mechanism in the development of pain remains unclear, a range of non-dopaminergic structures likely mediated pain processing in DLB in the present case based on neuropharmacological results. This is the first report reporting the effects of gabapentin enacarbil for RLS and leg pain in a DLB patient with psychiatric symptoms. © 2014 The Author. Psychogeriatrics © 2014 Japanese Psychogeriatric Society.

  7. LEGS AND TRUNK MUSCLE HYPERTROPHY FOLLOWING WALK TRAINING WITH RESTRICTED LEG MUSCLE BLOOD FLOW

    Directory of Open Access Journals (Sweden)

    Mikako Sakamaki

    2011-06-01

    Full Text Available We examined the effect of walk training combined with blood flow restriction (BFR on the size of blood flow-restricted distal muscles, as well as, on the size of non-restricted muscles in the proximal limb and trunk. Nine men performed walk training with BFR and 8 men performed walk training alone. Training was conducted two times a day, 6 days/wk, for 3 wk using five sets of 2-min bouts (treadmill speed at 50 m/min, with a 1-min rest between bouts. After walk training with BFR, MRI-measured upper (3.8%, P < 0.05 and lower leg (3.2%, P < 0. 05 muscle volume increased significantly, whereas the muscle volume of the gluteus maximus (-0.6% and iliopsoas (1.8% and the muscle CSA of the lumber L4-L5 (-1.0 did not change. There was no significant change in muscle volume in the walk training alone. Our results suggest that the combination of leg muscle blood flow restriction with slow walk training elicits hypertrophy only in the distal blood flow restricted leg muscles. Exercise intensity may be too low during BFR walk training to increase muscle mass in the non- blood flow restricted muscles (gluteus maximus and other trunk muscles.

  8. 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.

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

    International Nuclear Information System (INIS)

    Lee, Jong Hwi; Kang, Hie Chan; Noh, Hyung Gyun

    2016-01-01

    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.

  10. Protection against high intravascular pressure in giraffe legs.

    Science.gov (United States)

    Petersen, Karin K; Hørlyck, Arne; Ostergaard, Kristine H; Andresen, Joergen; Broegger, Torbjoern; Skovgaard, Nini; Telinius, Niklas; Laher, Ismael; Bertelsen, Mads F; Grøndahl, Carsten; Smerup, Morten; Secher, Niels H; Brøndum, Emil; Hasenkam, John M; Wang, Tobias; Baandrup, Ulrik; Aalkjaer, Christian

    2013-11-01

    The high blood pressure in giraffe leg arteries renders giraffes vulnerable to edema. We investigated in 11 giraffes whether large and small arteries in the legs and the tight fascia protect leg capillaries. Ultrasound imaging of foreleg arteries in anesthetized giraffes and ex vivo examination revealed abrupt thickening of the arterial wall and a reduction of its internal diameter just below the elbow. At and distal to this narrowing, the artery constricted spontaneously and in response to norepinephrine and intravascular pressure recordings revealed a dynamic, viscous pressure drop along the artery. Histology of the isolated median artery confirmed dense sympathetic innervation at the narrowing. Structure and contractility of small arteries from muscular beds in the leg and neck were compared. The arteries from the legs demonstrated an increased media thickness-to-lumen diameter ratio, increased media volume, and increased numbers of smooth muscle cells per segment length and furthermore, they contracted more strongly than arteries from the neck (500 ± 49 vs. 318 ± 43 mmHg; n = 6 legs and neck, respectively). Finally, the transient increase in interstitial fluid pressure following injection of saline was 5.5 ± 1.7 times larger (n = 8) in the leg than in the neck. We conclude that 1) tissue compliance in the legs is low; 2) large arteries of the legs function as resistance arteries; and 3) structural adaptation of small muscle arteries allows them to develop an extraordinary tension. All three findings can contribute to protection of the capillaries in giraffe legs from a high arterial pressure.

  11. Single-leg squats can predict leg alignment in dancers performing ballet movements in “turnout”

    Directory of Open Access Journals (Sweden)

    Hopper LS

    2016-11-01

    Full Text Available Luke S Hopper,1 Nahoko Sato,2 Andries L Weidemann1 1Western Australian Academy of Performing Arts, Edith Cowan University, Mt Lawley, WA, Australia; 2Department of Physical Therapy, Nagoya Gakuin University, Seto, Japan Abstract: The physical assessments used in dance injury surveillance programs are often adapted from the sports and exercise domain. Bespoke physical assessments may be required for dance, particularly when ballet movements involve “turning out” or external rotation of the legs beyond that typically used in sports. This study evaluated the ability of the traditional single-leg squat to predict the leg alignment of dancers performing ballet movements with turnout. Three-dimensional kinematic data of dancers performing the single-leg squat and five ballet movements were recorded and analyzed. Reduction of the three-dimensional data into a one-dimensional variable incorporating the ankle, knee, and hip joint center positions provided the strongest predictive model between the single-leg squat and the ballet movements. The single-leg squat can predict leg alignment in dancers performing ballet movements, even in “turned out” postures. Clinicians should pay careful attention to observational positioning and rating criteria when assessing dancers performing the single-leg squat. Keywords: injury, motion capture, clinical assessment

  12. 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.

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

    Science.gov (United States)

    Hu, W. R.

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

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

    Science.gov (United States)

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

    2014-03-11

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

  15. 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.

  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. Analysis of Threshold Voltage Flexibility in Ultrathin-BOX SOI FinFETs

    Directory of Open Access Journals (Sweden)

    Kazuhiko Endo

    2014-05-01

    Full Text Available A threshold voltage (Vth controllable multigate FinFET on a 10-nm-thick ultrathin BOX (UTB SOI substrate have been investigated. It is revealed that the Vth of the FinFET on the UTB SOI substrate is effectively modulated thanks to the improved coupling between the Si channel and the back gate. We have also carried out analysis of the Vth controllability in terms of the size dependence such as the gate length (LG and the fin width (TFin.

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

    DEFF Research Database (Denmark)

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

    2002-01-01

    , and therefore support the hypothesis that MPF swimming is more efficient. In addition, use of the BCF gait at higher swimming speed increased the cost of transport in both species beyond that predicted for MPF swimming at the same speeds. This suggests that, unlike for terrestrial locomotion, gait transition......To determine the energetic costs of rigid-body, median or paired-fin (MPF) swimming versus undulatory, body-caudal fin (BCF) swimming, we measured oxygen consumption as a function of swimming speed in two MPF swimming specialists, Schlegel's parrotfish and Picasso triggerfish. The parrotfish swam...... exclusively with the pectoral fins at prolonged swimming speeds up to 3.2 total lengths per second (L s(-1); 30 min critical swimming speed, U(crit)). At higher speeds, gait transferred to a burst-and-coast BCF swimming mode that resulted in rapid fatigue. The triggerfish swam using undulations of the soft...

  19. 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)

  20. Artificial Leg Design and Control Research of a Biped Robot with Heterogeneous Legs Based on PID Control Algorithm

    Directory of Open Access Journals (Sweden)

    Hualong Xie

    2015-04-01

    Full Text Available A biped robot with heterogeneous legs (BRHL is proposed to provide an ideal test-bed for intelligent bionic legs (IBL. To make artificial leg gait better suited to a human, a four-bar mechanism is used as its knee joint, and a pneumatic artificial muscle (PAM is used as its driving source. The static mathematical model of PAM is established and the mechanical model of a single degree of freedom of a knee joint driven by PAM is analyzed. A control simulation of an artificial leg based on PID control algorithm is carried out and the simulation results indicate that the artificial leg can simulate precisely a normal human walking gait.

  1. Aura fractal, fins da arte e capitalismo primitivista

    Directory of Open Access Journals (Sweden)

    Leonardo Carvalho Bertolossi

    2017-10-01

    Full Text Available Objetiva-se refletir sobre as relações entre as artes visuais e a antropologia a partir do texto seminal de Walter Benjamin sobre a aura para pensar sobre as finalidades e os fins da metafísica da arte no Ocidente diante dos diagnósticos de fim de mundo/fim da história da arte, e da vitória do espetáculo e da indústria cultural no capitalismo contemporâneo. O artigo apresenta alguns dos sentidos da arte no mundo ocidental e em especial no romantismo, avança sobre a crise e o fim dos modelos estruturais e cognitivos do pensamento artístico moderno, destaca o interesse pela política e pela vida, e se indaga sobre a retomada do primitivismo nas artes visuais e na antropologia contemporânea como redenção e renovação das mortes anunciadas. ABSTRACT The objective is to reflect on the relations between the visual arts and anthropology from Walter Benjamin's seminal text on the aura to think about the purposes and ends of the metaphysics of art in the West in the face of end-of-world/end-of-art history, and the victory of spectacle and cultural industry in contemporary capitalism. The article presents some of the meanings of art in the Western world and especially in Romanticism, advances on the crisis and the end of the structural and cognitive models of modern artistic thought, highlights the interest in politics and life, and inquires about the resumption of Primitivism in the visual arts and contemporary anthropology as redemption and renewal of the announced deaths. KEYWORDS Anthropology of art, aura, soul, thanatology, primitivism

  2. 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.

  3. Differential diagnosis of unpleasant sensations in the legs: prevalence of restless legs syndrome in a primary care population.

    Science.gov (United States)

    Möller, Caroline; Wetter, Thomas C; Köster, Jürgen; Stiasny-Kolster, Karin

    2010-02-01

    Restless legs syndrome (RLS) is a common neurological condition. We investigated the prevalence of RLS in patients suffering from unpleasant sensations in the legs. We included 16,543 patients consulting one of 312 primary care practices in Germany on November 8, 2007. All patients filled out a self-assessment questionnaire. Patients who reported suffering from unpleasant sensations in the legs were then assessed by the physician. Main outcome measures were the overall prevalence of unpleasant sensations in the legs and the prevalence of RLS; the most common differential diagnoses in the subpopulation suffered from unpleasant leg sensations. Out of all participating patients 7704 (46.6%) suffered from unpleasant sensations in the legs and 1758 (10.6%) were diagnosed with RLS according to the four essential clinical criteria. Among patients with unpleasant leg sensations, the prevalence of RLS was considerably higher (22.7%) than in the total population. The most common differential diagnoses were osteoarthritis (21.5%), disc lesion (19.2%), varicose veins (18.8%) and muscle cramps (14.6%). Of the patients with RLS 53.4% had already consulted their physician about their leg problems in the past. Still, only 20.1% of the RLS patients had received the correct diagnosis. Comorbidity rates were significantly increased in RLS patients compared to patients suffering from leg symptoms of other origin. This study showed a high prevalence of RLS in primary care patients with unpleasant sensations in the legs. Thus, in patients presenting with these symptoms the diagnosis of RLS should routinely be considered. 2009 Elsevier B.V. All rights reserved.

  4. Restless legs syndrome in patients on dialysis

    International Nuclear Information System (INIS)

    AlJahdali, Hamdan H; AlQadhi, Waleed A; Khogeer, Haithm A; AlHejaili, Fayez F; Al Sayyari, Abdullah A; AlGhamdi, Saeed M

    2009-01-01

    Restless legs syndrome (RLS) is an extremely distressing problem experienced by patients on dialysis; the prevalence appears to be greater than in the general population, with a wide variation from 6.6% to 80%. The diagnosis of RLS is a clinical one, and its definition has been clarified and standardized by internationally recognized diagnostic criteria, published in 1995 by the International Restless Legs Syndrome Study Group (IRLSSG). This study was designed to find out the prevalence of RLS in Saudi patients with end-stage renal disease (ESRD) on maintenance dialysis. This is a cross sectional study carried out between May and Sept 2007 at two centers, King Abdulaziz Medical City-King Fahad National Guard Hospital (KAMC-KFNGH), Riyadh and King Faisal Specialist Hospital and Research Centre (KFHRC), Jeddah, Saudi Arabia. Data were gathered on 227 Saudi patients on chronic maintenance hemodialysis or chronic peritoneal dialysis. The prevalence of RLS was measured using IRLSSG's RLS Questionnaire (RLSQ). Potential risk factors for RLS including other sleep disorders, underlying cause of chronic renal failure, duration on dialysis, dialysis shift, biochemical tests and demographic data were also evaluated. The overall prevalence of RLS was 50.22% including 53.7% males and 46.3% females. Their mean age was 55.7 + - 17.2 years and mean duration on dialysis 40.4 + - 37.8 months. Significant predictors of RLS were history of diabetes mellitus (DM), coffee intake, afternoon dialysis, gender and type of dialysis (P= 0.03, 0.01, < 0.001, 0.05 and 0.009 respectively). Patients with RLS were found to be at increased risk of having insomnia and excessive daytime sleepiness (EDS) (P= < 0.001 and 0.001, respectively). Our study suggests that RLS is a very common problem in dialysis population and was significantly associated with other sleep disorders, particularly insomnia, and EDS. Optimal care of dialysis patient should include particular attention to the diagnosis and

  5. Restless legs syndrome in patients on dialysis

    Directory of Open Access Journals (Sweden)

    Al-Jahdali Hamdan

    2009-01-01

    Full Text Available Restless legs syndrome (RLS is an extremely distressing problem experienced by patients on dialysis; the prevalence appears to be greater than in the general population, with a wide variation from 6.6% to 80%. The diagnosis of RLS is a clinical one, and its definition has been clarified and standardized by internationally recognized diagnostic criteria, published in 1995 by the International Restless Legs Syndrome Study Group (IRLSSG. This study was designed to find out the prevalence of RLS in Saudi patients with end-stage renal disease (ESRD on maintenance dialysis. This is a cross sectional study carried out between May and Sept 2007 at two centers, King Abdulaziz Medical City-King Fahad National Guard Hospital (KAMC-KFNGH, Riyadh and King Faisal Specialist Hospital and Research Centre (KFHRC, Jeddah, Saudi Arabia. Data were gathered on 227 Saudi patients on chronic maintenance hemodialysis or chronic peritoneal dialysis. The prevalence of RLS was measured using IRLSSG′s RLS Questionnaire (RLSQ. Potential risk factors for RLS including other sleep disorders, underlying cause of chronic renal failure, duration on dialysis, dialysis shift, biochemical tests and demographic data were also evaluated. The overall prevalence of RLS was 50.22% including 53.7% males and 46.3% females. Their mean age was 55.7 ± 17.2 years and mean duration on dialysis 40.4 ± 37.8 months. Significant predictors of RLS were history of diabetes mellitus (DM, coffee intake, afternoon dialysis, gender and type of dialysis (P= 0.03, 0.01, < 0.001, 0.05 and 0.009 respectively. Patients with RLS were found to be at increased risk of having insomnia and excessive daytime sleepiness (EDS (P= < 0.001 and 0.001, respectively. Our study suggests that RLS is a very common problem in dialysis population and was significantly associated with other sleep disorders, particularly insomnia, and EDS. Optimal care of dialysis patient should include particular attention to the diagnosis

  6. Nurses' knowledge about venous leg ulcer care: a literature review.

    Science.gov (United States)

    Ylönen, M; Stolt, M; Leino-Kilpi, H; Suhonen, R

    2014-06-01

    There is an increasing prevalence of venous leg ulcers coinciding with increasing older people populations. They are therefore important health problems, which restrict daily activities and incur high costs. Efficient and comprehensive nursing care for people with venous leg ulcers requires knowledge of causes, presentations and characteristics, the effects that venous leg ulcers have on individuals and nursing care with evidence-based treatment. To identify the gaps between nurses' demonstrated knowledge of venous leg ulcers and the related nursing care treatment with evidence-based nursing care. A computerized search using MEDLINE, CINAHL the COCHRANE LIBRARY was conducted. The initial search yielded 174 citations from which 16 relevant articles were included in this review. Four themes in venous leg ulcer nursing care emerged demonstrating nurses' knowledge gaps: assessment, physiology and the healing process, nursing care and dressings, and compression treatment. This review suggests that there is a lack of knowledge related to venous leg ulcer physiology, the healing process and how this influences care and treatment. Nurses may not be using the evidence base sufficiently well to support ulcer healing and patient well-being. There is a need for a positive work culture development and ongoing educational programmes aimed at improving nurses' knowledge of venous leg ulcer treatment and care, which address the themes within the results of this review. © 2014 International Council of Nurses.

  7. Comparison of Alternative Gaits for Multiped Robots with Severed Legs

    Directory of Open Access Journals (Sweden)

    Tse-Shuen Shih

    2012-10-01

    Full Text Available Multiped robots have become the focus of heated discussion lately, especially in applications involving rescue or military missions and underwater or extra-terrestrial explorations. The surroundings concerned are harsh and hazardous terrains, and predictably the malfunction rate is high. What if a leg is irreparably damaged? The original gait can no longer be used and an alternative gait must be taken for the robot to continue its mission. This paper studies and enumerates preferred alternative gaits for six- and eight-legged robots under a proposed severed leg scheme. A leg is assumed to be completely detachable when a failure occurs. Based on a new criterion called the progressive efficiency (PE, defined via the enhanced gait charts, along with other criteria like the stride length and the longitudinal stability, alternative gaits are evaluated. The tables of recommended gaits in this paper are useful for robots when a leg failure is foreseen. These tables not only provide a guideline as to what alternative gait to use, they also give insight into how important a certain leg is. A comparison between the severed leg scheme and the existing locked-joint strategy is also included.

  8. Laterality of the legs in young female soccer players

    Directory of Open Access Journals (Sweden)

    Antosiak-Cyrak Katarzyna Z.

    2015-12-01

    Full Text Available Purpose. The aim of the present study was assessment of laterality of the legs of young female soccer players and their non-training counterparts. Methods. The study sample comprised 9 female soccer players and 19 non-training girls. They underwent three measurement sessions, one every six months. The applied tests included kinesthetic differentiation, rate of local movements, static balance, single-leg hop, rate of global movements, strength and speed, and functional asymmetry of the legs tests. Results. The soccer players were better than the controls in their performance of the rate of local movements, rate of global movements, kinesthetic differentiation, single-leg 15m timed hop and static balance tests. Smaller differences between the results of the left and the right legs in soccer players, than in non-training girls, were noted in the rate of local movements, rate of global movements and kinesthetic differentiation tests. In the static balance test, the differences were greater in the group of soccer players. Conclusions. Lateralization of the lower limbs is a highly complex characteristic with a different variability in athletes than in nontraining individuals. The results of the present study also point to the specialization of soccer players’ left legs in body balance and single-leg hop tests.

  9. Computational Fluid Dynamic (CFD) Analysis of a Generic Missile With Grid Fins

    National Research Council Canada - National Science Library

    DeSpirito, James

    2000-01-01

    This report presents the results of a study demonstrating an approach for using viscous computational fluid dynamic simulations to calculate the flow field and aerodynamic coefficients for a missile with grid fin...

  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. 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.

  12. Development and Application of Collaborative Optimization Software for Plate - fin Heat Exchanger

    Science.gov (United States)

    Chunzhen, Qiao; Ze, Zhang; Jiangfeng, Guo; Jian, Zhang

    2017-12-01

    This paper introduces the design ideas of the calculation software and application examples for plate - fin heat exchangers. Because of the large calculation quantity in the process of designing and optimizing heat exchangers, we used Visual Basic 6.0 as a software development carrier to design a basic calculation software to reduce the calculation quantity. Its design condition is plate - fin heat exchanger which was designed according to the boiler tail flue gas. The basis of the software is the traditional design method of the plate-fin heat exchanger. Using the software for design and calculation of plate-fin heat exchangers, discovery will effectively reduce the amount of computation, and similar to traditional methods, have a high value.

  13. Time-Accurate Numerical Prediction of Free Flight Aerodynamics of a Finned Projectile

    National Research Council Canada - National Science Library

    Sahu, Jubaraj

    2005-01-01

    This report describes a new multi-disciplinary computational study undertaken to compute the flight trajectories and to simultaneously predict the unsteady free flight aerodynamics of a finned projectile configuration...

  14. 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...

  15. Analytical Thermal and Cost Optimization of Micro-Structured Plate-Fin Heat Sink

    DEFF Research Database (Denmark)

    Rezaniakolaei, Alireza; Rosendahl, Lasse

    the thermal resistance and to maximize the cost performance of the heat sink. The width and the height of the microchannels, and the fin thickness are analytically optimized at a wide range of pumping power. Using an effective numeric test, the generated equations also discuss the optimum parameters at three......Microchannel heat sinks have been widely used in the field of thermo-fluids due to the rapid growth in technological applications which require high rates of heat transfer in relatively small spaces and volumes. In this work, a micro plate-fin heat sink is optimized parametrically, to minimize...... sizes of the substrate plat of the heat sink. Results show that, at any pumping power there are specific values of the channel width and fin thickness which produce minimum thermal resistance in the heat sink. The results also illustrate that, a larger channel width and a smaller fin thickness lead...

  16. Longline Observer (HI & Am. Samoa) Opah Fin Clip Collection for Lampris spp. Distribution Study

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data set containing information collected from the 1000+ fin clips collected by Hawaii & American Samoa Longline Observers that will be used to analyze the...

  17. 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

    2013-01-01

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

  18. 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.

  19. Fin-and-tube heat exchanger enhancement with a combined herringbone and vortex generator design

    DEFF Research Database (Denmark)

    Välikangas, Turo; Singh, Shobhana; Sørensen, Kim

    2018-01-01

    Vortex generators (VGs) are the most commonly investigated enhancement methods in the field of improved heat exchangers. The aim of present work is to study the effect of VGs in a fin-and-tube heat exchanger (FTHE) with herringbone fin shape. The delta winglet VG design with length (s) and height...... (H) is selected based on previous studies. The investigated VG design is simple and considered realistic from the manufacturing point of view. The combined enhancement with herringbone fin and the VG is evaluated by simulating the conjugate heat transfer and the air flow. The structured mesh...... transfer in the herringbone fin but also decrease the pressure drop. The highest and longest investigated VG design is found to perform the best because of its ability to delay the flow detachment from the tube, to feed high kinetic energy flow to the recirculation zone and to create longitudinal vortices...

  20. Interaction Between Leg Muscle Performance and Sprint Acceleration Kinematics

    Directory of Open Access Journals (Sweden)

    Lockie Robert G.

    2015-12-01

    Full Text Available This study investigated relationships between 10 m sprint acceleration, step kinematics (step length and frequency, contact and flight time, and leg muscle performance (power, stiffness, strength. Twenty-eight field sport athletes completed 10 m sprints that were timed and filmed. Velocity and step kinematics were measured for the 0-5, 5-10, and 0-10 m intervals to assess acceleration. Leg power was measured via countermovement jumps (CMJ, a fivebound test (5BT, and the reactive strength index (RSI defined by 40 cm drop jumps. Leg stiffness was measured by bilateral and unilateral hopping. A three-repetition maximum squat determined strength. Pearson’s correlations and stepwise regression (p ≤ 0.05 determined velocity, step kinematics, and leg muscle performance relationships. CMJ height correlated with and predicted velocity in all intervals (r = 0.40-0.54. The 5BT (5-10 and 0-10 m intervals and RSI (5-10 m interval also related to velocity (r = 0.37-0.47. Leg stiffness did not correlate with acceleration kinematics. Greater leg strength related to and predicted lower 0-5 m flight times (r = -0.46 to -0.51, and a longer 0-10 m step length (r = 0.38. Although results supported research emphasizing the value of leg power and strength for acceleration, the correlations and predictive relationships (r2 = 0.14-0.29 tended to be low, which highlights the complex interaction between sprint technique and leg muscle performance. Nonetheless, given the established relationships between speed, leg power and strength, strength and conditioning coaches should ensure these qualities are expressed during acceleration in field sport athletes.

  1. Single leg stance control in individuals with symptomatic gluteal tendinopathy.

    Science.gov (United States)

    Allison, Kim; Bennell, Kim L; Grimaldi, Alison; Vicenzino, Bill; Wrigley, Tim V; Hodges, Paul W

    2016-09-01

    Lateral hip pain during single leg loading, and hip abductor muscle weakness, are associated with gluteal tendinopathy, but it has not been shown how or whether kinematics in single leg stance differ in those with gluteal tendinopathy. To compare kinematics in preparation for, and during, single leg stance between individuals with and without gluteal tendinopathy, and the effect of hip abductor muscle strength on kinematics. Twenty individuals with gluteal tendinopathy and 20 age-matched pain-free controls underwent three-dimensional kinematic analysis of single leg stance and maximum isometric hip abductor strength testing. Maximum values of hip adduction, pelvic obliquity (contralateral pelvis rise/drop), lateral pelvic translation (ipsilateral/contralateral shift) and ipsilateral trunk lean during preparation for leg lift and average values in steady single leg stance, were compared between groups using an analysis of covariance, with and without anthropometric characteristics and strength as covariates. Individuals with gluteal tendinopathy demonstrated greater hip adduction (standardized mean difference (SMD)=0.70, P=0.04) and ipsilateral pelvic shift (SMD=1.1, P=0.002) in preparation for leg lift, and greater hip adduction (SMD=1.2, P=0.002) and less contralateral pelvic rise (SMD=0.86, P=0.02) in steady single leg stance than controls. When including strength as a covariate, only between-group differences in lateral pelvic shift persisted (SMD=1.7, P=0.01). Individuals with gluteal tendinopathy use different frontal plane kinematics of the hip and pelvis during single leg stance than pain-free controls. This finding is not influenced by pelvic dimension or the potentially modifiable factor of body mass index, but is by hip abductor muscle weakness. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Interaction Between Leg Muscle Performance and Sprint Acceleration Kinematics.

    Science.gov (United States)

    Lockie, Robert G; Jalilvand, Farzad; Callaghan, Samuel J; Jeffriess, Matthew D; Murphy, Aron J

    2015-12-22

    This study investigated relationships between 10 m sprint acceleration, step kinematics (step length and frequency, contact and flight time), and leg muscle performance (power, stiffness, strength). Twenty-eight field sport athletes completed 10 m sprints that were timed and filmed. Velocity and step kinematics were measured for the 0-5, 5-10, and 0-10 m intervals to assess acceleration. Leg power was measured via countermovement jumps (CMJ), a five-bound test (5BT), and the reactive strength index (RSI) defined by 40 cm drop jumps. Leg stiffness was measured by bilateral and unilateral hopping. A three-repetition maximum squat determined strength. Pearson's correlations and stepwise regression (p ≤ 0.05) determined velocity, step kinematics, and leg muscle performance relationships. CMJ height correlated with and predicted velocity in all intervals (r = 0.40-0.54). The 5BT (5-10 and 0-10 m intervals) and RSI (5-10 m interval) also related to velocity (r = 0.37-0.47). Leg stiffness did not correlate with acceleration kinematics. Greater leg strength related to and predicted lower 0-5 m flight times (r = -0.46 to -0.51), and a longer 0-10 m step length (r = 0.38). Although results supported research emphasizing the value of leg power and strength for acceleration, the correlations and predictive relationships (r(2) = 0.14-0.29) tended to be low, which highlights the complex interaction between sprint technique and leg muscle performance. Nonetheless, given the established relationships between speed, leg power and strength, strength and conditioning coaches should ensure these qualities are expressed during acceleration in field sport athletes.

  3. 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

  4. Pramipexole alters thermoregulation in restless legs syndrome.

    Science.gov (United States)

    Salminen, Aaro V; Rimpilä, Ville; Polo, Olli

    2014-12-15

    Previous studies have associated restless legs syndrome (RLS) with peripheral hypoxia and impaired thermoregulation in the lower extremities. We performed long-term monitoring of skin temperatures in order to investigate whether these findings could be explained by reduced blood flow to the peripheral tissues. 96-hour continuous measurements of skin temperature were performed both in the distal and proximal parts of the body of 15 patients with RLS and 14 healthy controls. During the recording, the patients participated in suggested immobilization tests both with and without pramipexole medication. We found no baseline differences in distal or proximal skin temperature between patients and controls in daytime or during immobilization. However, pramipexole significantly increased distal skin temperature in the patient group during immobilization (31.1°C vs. 32.9°C, p thermoregulation and the previous studies might have been biased by medication. Dopaminergic medication is a major confounding factor when assessing peripheral phenomena in RLS and should be controlled for in the future studies. © 2014 American Academy of Sleep Medicine.

  5. Restless legs syndrome associated with major diseases

    Science.gov (United States)

    Allen, Richard; Högl, Birgit; Paulus, Walter

    2016-01-01

    Recent publications on both the genetics and environmental factors of restless legs syndrome (RLS) defined as a clinical disorder suggest that overlapping genetic risk factors may play a role in primary (idiopathic) and secondary (symptomatic) RLS. Following a systematic literature search of RLS associated with comorbidities, we identified an increased prevalence of RLS only in iron deficiency and kidney disease. In cardiovascular disease, arterial hypertension, diabetes, migraine, and Parkinson disease, the methodology of studies was poor, but an association might be possible. There is insufficient evidence for conditions such as anemia (without iron deficiency), chronic obstructive pulmonary disease, multiple sclerosis, headache, stroke, narcolepsy, and ataxias. Based on possible gene–microenvironmental interaction, the classifications primary and secondary RLS may suggest an inappropriate causal relation. We recognize that in some conditions, treatment of the underlying disease should be achieved as far as possible to reduce or eliminate RLS symptoms. RLS might be seen as a continuous spectrum with a major genetic contribution at one end and a major environmental or comorbid disease contribution at the other. PMID:26944272

  6. Restless legs syndrome and pregnancy: A review

    Science.gov (United States)

    Srivanitchapoom, Prachaya; Pandey, Sanjay; Hallett, Mark

    2014-01-01

    Restless legs syndrome (RLS) is a common sensorimotor neurological disorder that is diagnosed according to the revised criteria of the International RLS Study Group (IRLSSG). The pathophysiology of RLS is still unknown and its prevalence is influenced by ethnicity, age, and gender. RLS is divided into two types by etiology: primary or idiopathic and secondary. Primary RLS is strongly influenced by a genetic component while secondary RLS is caused by other associated conditions such as end-stage renal disease or peripheral neuropathy. Another common condition associated with RLS is pregnancy. The prevalence of RLS during pregnancy is two to three times higher than in the normal population and is influenced by the trimester and the number of parity. The main mechanisms that may contribute to the pathophysiology of RLS during pregnancy are hormonal changes and iron and folate status. Standard medications for treating RLS during pregnancy are not established. Most medications have been used according to the evidence from non-pregnant patients. Therefore, consideration of the medical treatment for treating RLS during pregnancy should be balanced between the benefit of relieving the symptoms and maternal and fetal risk. In general, the prognosis of RLS during pregnancy is good and symptoms are usually relieved after delivery. PMID:24768121

  7. Clinical correlates of the restless legs syndrome

    Directory of Open Access Journals (Sweden)

    Luis Fabiano Marin

    2012-07-01

    Full Text Available OBJECTIVE: To determine the clinical correlates of the restless legs syndrome (RLS in a Brazilian sleep disorders center. METHODS: We retrospectively studied 118 patients with RLS from January, 2004, to December, 2010. The analyzed variables were: age at disease onset, gender, race, years of school instruction, primary and secondary RLS, and treatment options. RESULTS: Among the studied patients, 83.9% were women with a female/male sex ratio of 5:1. Mean age of the patients at symptom onset ± standard deviation was 41.7±17.9 years-old. The primary RLS was found in 85% of patients. The other 15% remainders consisted of secondary forms, and they were associated with neuropathy, iron deficiency anemia, end-stage renal disease, or Parkinson's disease. Drug therapy for RLS was introduced in 67% of patients. CONCLUSIONS: Most patients presented primary RLS with an early disease onset. Further epidemiological studies are welcomed to provide better information on secondary RLS in Brazil.

  8. Analytical Study of Active Prosthetic Legs

    Science.gov (United States)

    Ono, Kyosuke; Katsumata, Mie

    Walking with prosthesis has not been well analyzed mathematically and it seems that the design of powered prosthesis has been done empirically so far. This paper presents a dynamic simulation of a normal human walking and walking with an active prosthesis. We also studied the two controlling methods of a powered thigh prosthesis based on multi-body simulation of human walking. First we measured the normal human walking gait, then, we showed that a 3-DOF human walking model can walk on level ground by applying tracking control to the measured walking gait within a certain range of tuned walking period. Next, we applied the tracking control and self-excited control to the powered thigh prosthesis and compared the robustness and efficiency of the two control methods by numerical simulation. As a result, we found that the self-excited control can significantly decrease the hip joint torque and specific cost to 1/3 compared with the tracking control. Moreover, the self-excited control is superior to the tracking control because tuning for the walking period is not needed for the active prosthetic leg.

  9. [Prophylaxis of Recurrent Venous Leg Ulcer].

    Science.gov (United States)

    Kroeger, K; Storck, M; Kujath, P; Rabe, E; Dissemond, J

    2017-06-01

    Venous leg ulcer (VLU) counts among the most common chronic wounds in Europe. Treatment is lengthy, cumbersome and costly, and there is a high rate of recurrence. This review shows the measures that should be offered to every patient with healed VLU to permanently prevent recurrence. To prevent VLU in case of varicose veins, the progression of chronic venous insufficiency (CVI) has to be stopped. There is convincing evidence that the effective treatment of varicose veins reduces the recurrence rate in patients with VLU. In patients with post-thrombotic syndrome (PTS), further thrombosis should be prevented through targeted prophylaxis of new thromboembolic events. The benefit of endovascular revascularization on the VLU recurrence rate in patients with post-thrombotic damage in the pelvic veins has not been proven in clinical studies. On the other hand, it has been clearly demonstrated in several studies that compression therapy is the basic procedure for the prevention of recurrent VLU in patients with varicose veins or PTS, regardless of whether other measures have been implemented or not. Good adherence in patients with compression therapy is more important than choosing the highest possible compression class. Future efforts for patients with VLU must aim to provide therapists with tools and treatment strategies to guide their patients and to increase patients' acceptance and understanding of the importance of self-management, in particular regarding compression therapy for the prevention of recurrent VLU. Georg Thieme Verlag KG Stuttgart · New York.

  10. Primary headaches in restless legs syndrome patients

    Directory of Open Access Journals (Sweden)

    Ravi Gupta

    2012-01-01

    Full Text Available Earlier studies conducted among migraineurs have shown an association between migraine and restless legs syndrome (RLS. We chose RLS patients and looked for migraine to exclude sample bias. Materials and Methods: 99 consecutive subjects of idiopathic RLS were recruited from the sleep clinic during four months period. Physician diagnosis of headache and depressive disorder was made with the help of ICHD-2 and DSM-IV-TR criteria, respectively. Sleep history was gathered. Severity of RLS and insomnia was measured using IRLS (Hindi version and insomnia severity index Hindi version, respectively. Chi-square test, one way ANOVA and t-test were applied to find out the significance. Results: Primary headache was seen in 51.5% cases of RLS. Migraine was reported by 44.4% subjects and other types of ′primary headaches′ were reported by 7.1% subjects. Subjects were divided into- RLS; RLS with migraine and RLS with other headache. Females outnumbered in migraine subgroup (χ2 =16.46, P<0.001. Prevalence of depression (χ2 =3.12, P=0.21 and family history of RLS (χ2 =2.65, P=0.26 were not different among groups. Severity of RLS (P=0.22 or insomnia (P=0.43 were also similar. Conclusion: Migraine is frequently found in RLS patients in clinic based samples. Females with RLS are prone to develop migraine. Depression and severity of RLS or insomnia do not affect development of headache.

  11. Peripheral Dopamine in Restless Legs Syndrome

    Directory of Open Access Journals (Sweden)

    Ulrike H. Mitchell

    2018-03-01

    Full Text Available Objective/BackgroundRestless Legs Syndrome (RLS is a dopamine-dependent disorder characterized by a strong urge to move. The objective of this study was to evalulate blood levels of dopamine and other catecholamines and blood D2-subtype dopamine receptors (D2Rs in RLS.Patients/MethodsDopamine levels in blood samples from age-matched unmedicated RLS subjects, medicated RLS subjects and Controls were evaluated with high performance liquid chromatography and dopamine D2R white blood cell (WBC expression levels were determined with fluorescence-activated cell sorting and immunocytochemistry.ResultsBlood plasma dopamine levels, but not norepinepherine or epinephrine levels, were significantly increased in medicated RLS subjects vs unmedicated RLS subjects and Controls. The percentage of lymphocytes and monocytes expressing D2Rs differed between Control, RLS medicated and RLS unmedicated subjects. Total D2R expression in lymphocytes, but not monocytes, differed between Control, RLS medicated and RLS unmedicated subjects. D2Rs in lymphocytes, but not monocytes, were sensitive to dopamine in Controls only.ConclusionDownregulation of WBCs D2Rs occurs in RLS. This downregulation is not reversed by medication, although commonly used RLS medications increase plasma dopamine levels. The insensitivity of monocytes to dopamine levels, but their downregulation in RLS, may reflect their utility as a biomarker for RLS and perhaps brain dopamine homeostasis.

  12. [Innovative therapy for leg ulcers: Electrostimulation].

    Science.gov (United States)

    Maillard, H

    2015-01-01

    Chronic wounds can take a long time to heal despite appropriate therapy based upon aetiology and use of suitable dressings. The success of electrostimulation is based upon the existence within the skin of the endogenous currents involved in the wound healing process. Where skin continuity is broken by a wound, these electrical potentials are short-circuited, resulting in leakage of electrical current. Woundel(®) therapy is the only such treatment currently available in France and is based on the use of continuous pulsed current that generates an electrical field near the endogenous electrical fields. It utilises a console to deliver the electrical impulses, a dressing electrode and a dispersion electrode. The electrode dressing is left on the wound for 3 days, and venous compression bandaging may be applied to the leg, taking care to leave the connector free. Negative polarity stimulates migration of fibroblasts, resulting in elimination of fibrin. Positive polarity causes keratinocyte migration, which in turn leads to epidermisation. Electrostimulation is of recognised utility in the healing of chronic wounds: it has been assigned a high-level recommendation in the European and American guidelines for the treatment of venous ulcers and bedsores with proof level of A. Further, the analgesic effect of electrostimulation has been demonstrated in several studies. Electrostimulation is already well developed in France among wound specialists, but prospective studies are planned so that it may be used at patients' homes. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  13. Adjuvant Biological Therapies in Chronic Leg Ulcers

    Directory of Open Access Journals (Sweden)

    Natalia Burgos-Alonso

    2017-11-01

    Full Text Available Current biological treatments for non-healing wounds aim to address the common deviations in healing mechanisms, mainly inflammation, inadequate angiogenesis and reduced synthesis of extracellular matrix. In this context, regenerative medicine strategies, i.e., platelet rich plasmas and mesenchymal stromal cell products, may form part of adjuvant interventions in an integral patient management. We synthesized the clinical experience on ulcer management using these two categories of biological adjuvants. The results of ten controlled trials that are included in this systematic review favor the use of mesenchymal stromal cell based-adjuvants for impaired wound healing, but the number and quality of studies is moderate-low and are complicated by the diversity of biological products. Regarding platelet-derived products, 18 controlled studies investigated their efficacy in chronic wounds in the lower limb, but the heterogeneity of products and protocols hinders clinically meaningful quantitative synthesis. Most patients were diabetic, emphasizing an unmet medical need in this condition. Overall, there is not sufficient evidence to inform routine care, and further clinical research is necessary to realize the full potential of adjuvant regenerative medicine strategies in the management of chronic leg ulcers.

  14. 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

  15. 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)

  16. 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.

  17. Fin efficiency in 2D with convection at the tip and dissymmetry of exchange

    Energy Technology Data Exchange (ETDEWEB)

    Bouaziz, Najib [Department of Mechanical Engineering, University of Medea, BP 164, Medea 26000 (Algeria)

    2009-06-15

    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. (author)

  18. 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.

  19. 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

  20. Joint variable stiffness of musculoskeletal leg mechanism for quadruped robot

    OpenAIRE

    Lei, J; Zhu, J; Xie, P; Tokhi, MO

    2017-01-01

    © The Author(s) 2017. When the quadruped robot is in locomotion such as jumping and running with higher speed, there is non-continuous contact force between the foot and the environment inevitably. In order to achieve the flexible force interaction of the bionic legs with the environment, it is necessary to analyze the joint angular stiffness of the bionic leg. In this article, based on the designing principles of the bionics, light-weighted, and flexible, a kind of musculoskeletal bionic leg...