A quasi-one-dimensional theory of sound propagation in lined ducts with mean flow

Science.gov (United States)

Dokumaci, Erkan

2018-04-01

Sound propagation in ducts with locally-reacting liners has received the attention of many authors proposing two- and three-dimensional solutions of the convected wave equation and of the Pridmore-Brown equation. One-dimensional lined duct models appear to have received less attention. The present paper proposes a quasi-one-dimensional theory for lined uniform ducts with parallel sheared mean flow. The basic assumption of the theory is that the effects of refraction and wall compliance on the fundamental mode remain within ranges in which the acoustic fluctuations are essentially uniform over a duct section. This restricts the model to subsonic low Mach numbers and Helmholtz numbers of less than about unity. The axial propagation constants and the wave transfer matrix of the duct are given by simple explicit expressions and can be applied with no-slip, full-slip or partial slip boundary conditions. The limitations of the theory are discussed and its predictions are compared with the fundamental mode solutions of the convected wave equation, the Pridmore-Brown equation and measurements where available.

Preparation of steel slag porous sound-absorbing material using coal powder as pore former.

Science.gov (United States)

Sun, Peng; Guo, Zhancheng

2015-10-01

The aim of the study was to prepare a porous sound-absorbing material using steel slag and fly ash as the main raw material, with coal powder and sodium silicate used as a pore former and binder respectively. The influence of the experimental conditions such as the ratio of fly ash, sintering temperature, sintering time, and porosity regulation on the performance of the porous sound-absorbing material was investigated. The results showed that the specimens prepared by this method had high sound absorption performance and good mechanical properties, and the noise reduction coefficient and compressive strength could reach 0.50 and 6.5MPa, respectively. The compressive strength increased when the dosage of fly ash and sintering temperature were raised. The noise reduction coefficient decreased with increasing ratio of fly ash and reducing pore former, and first increased and then decreased with the increase of sintering temperature and time. The optimum preparation conditions for the porous sound-absorbing material were a proportion of fly ash of 50% (wt.%), percentage of coal powder of 30% (wt.%), sintering temperature of 1130°C, and sintering time of 6.0hr, which were determined by analyzing the properties of the sound-absorbing material. Copyright © 2015. Published by Elsevier B.V.

Comparison of sound absorbing performances of copper foam and iron foam with the same parameters

Science.gov (United States)

Yang, X. C.; Shen, X. M.; Xu, P. J.; Zhang, X. N.; Bai, P. F.; Peng, K.; Yin, Q.; Wang, D.

2018-01-01

Sound absorbing performances of the copper foam and the iron foam with the same parameters were investigated by the AWA6128A detector according to standing wave method. Two modes were investigated, which included the pure metal foam mode and the combination mode with the settled thickness of metal foam. In order to legibly compare the sound absorbing coefficients of the two metal foams, the detected sound frequency points were divided into the low frequency range (100 Hz ~ 1000 Hz), the middle frequency range (1000 Hz ~ 3200 Hz), and the high frequency range (3500 Hz ~ 6000 Hz). Sound absorbing performances of the two metal foams in the two modes were discussed within the three frequency ranges in detail. It would be calculated that the average sound absorbing coefficients of copper foam in the pure metal foam mode were 12.6%, 22.7%, 34.6%, 43.6%, 51.1%, and 56.2% when the thickness was 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, and 30 mm. meanwhile, in the combination mode, the average sound absorbing coefficients of copper foam with the thickness of 10 mm were 30.6%, 34.8%, 36.3%, and 35.8% when the cavity was 5 mm, 10 mm, 15 mm, and 20 mm. In addition, those of iron foam in the pure metal foam mode were 13.4%, 20.1%, 34.4%, 43.1%, 49.6%, and 56.1%, and in the combination mode were 25.6%, 30.5%, 34.3%, and 33.4%.

Broadband transmission noise reduction of smart panels featuring piezoelectric shunt circuits and sound-absorbing material.

Science.gov (United States)

Kim, Jaehwan; Lee, Joong-Kuen

2002-09-01

The possibility of a broadband noise reduction of piezoelectric smart panels is experimentally studied. A piezoelectric smart panel is basically a plate structure on which piezoelectric patches with electrical shunt circuits are mounted and sound-absorbing material is bonded on the surface of the structure. Sound-absorbing material can absorb the sound transmitted at the midfrequency region effectively while the use of piezoelectric shunt damping can reduce the transmission at resonance frequencies of the panel structure. To be able to reduce the sound transmission at low panel resonance frequencies, piezoelectric damping using the measured electrical impedance model is adopted. A resonant shunt circuit for piezoelectric shunt damping is composed of resistor and inductor in series, and they are determined by maximizing the dissipated energy through the circuit. The transmitted noise-reduction performance of smart panels is tested in an acoustic tunnel. The tunnel is a square cross-sectional tube and a loudspeaker is mounted at one side of the tube as a sound source. Panels are mounted in the middle of the tunnel and the transmitted sound pressure across panels is measured. When an absorbing material is bonded on a single plate, a remarkable transmitted noise reduction in the midfrequency region is observed except for the fundamental resonance frequency of the plate. By enabling the piezoelectric shunt damping, noise reduction is achieved at the resonance frequency as well. Piezoelectric smart panels incorporating passive absorbing material and piezoelectric shunt damping is a promising technology for noise reduction over a broadband of frequencies.

Acoustic behavior of a fibrous bulk material. [Kevlar 29 sound absorber

Science.gov (United States)

Hersh, A. S.; Walker, B.

1979-01-01

A semiempirical model is presented describing the acoustic behavior of Kevlar 29, a bulk absorbing material. The model is based on an approximate solution to the one-dimensional equations representing conservation of fluctuating mass, momentum and energy. By treating the material as a momentum sink, theoretical expressions of the material complex propagation constants and characteristic impedance were derived in terms of a single constant. Evaluating the constant at a single frequency for a particular specimen, excellent agreement between prediction and measurement was achieved for a large range of sound frequencies and material porosities and thicknesses. Results show that Kevlar 29 absorbs sound efficiently even at low frequencies. This is explained in terms of a frequency dependent material phase speed.

On modeling the sound propagation through a lined duct with a modified Ingard-Myers boundary condition

Science.gov (United States)

Yang, Cheng; Fang, Yi; Zhao, Chao; Zhang, Xin

2018-06-01

A duct acoustics model is an essential component of an impedance eduction technique and its computation cost determines the impedance measurement efficiency. In this paper, a model is developed for the sound propagation through a lined duct carrying a uniform mean flow. In contrast to many existing models, the interface between the liner and the duct field is defined with a modified Ingard-Myers boundary condition that takes account of the effect of the boundary layer above the liner. A mode-matching method is used to couple the unlined and lined duct segments for the model development. For the lined duct segment, the eigenvalue problem resulted from the modified boundary condition is solved by an integration scheme which, on the one hand, allows the lined duct modes to be computed in an efficient manner, and on the other hand, orders the modes automatically. The duct acoustics model developed from the solved lined duct modes is shown to converge more rapidly than the one developed from the rigid-walled duct modes. Validation against the experiment data in the literature shows that the proposed model is able to predict more accurately the liner performance measured by the two-source method. This, however, cannot be made by a duct acoustics model associated with the conventional Ingard-Myers boundary condition. The proposed model has the potential to be integrated into an impedance eduction technique for more reliable liner measurement.

Producing of Impedance Tube for Measurement of Acoustic Absorption Coefficient of Some Sound Absorber Materials

Directory of Open Access Journals (Sweden)

R. Golmohammadi

2008-04-01

Full Text Available Introduction & Objective: Noise is one of the most important harmful agents in work environment. In spit of industrial improvements, exposure with over permissible limit of noise is counted as one of the health complication of workers. In Iran, do not exact information of the absorption coefficient of acoustic materials. Iranian manufacturer have not laboratory for measured of sound absorbance of their products, therefore using of sound absorber is limited for noise control in industrial and non industrial constructions. The goal of this study was to design an impedance tube based on pressure method for measurement of the sound absorption coefficient of acoustic materials.Materials & Methods: In this study designing of measuring system and method of calculation of sound absorption based on a available equipment and relatively easy for measurement of the sound absorption coefficient related to ISO10534-1 was performed. Measuring system consist of heavy asbestos tube, a pure tone sound generator, calibrated sound level meter for measuring of some commonly of sound absorber materials was used. Results: In this study sound absorption coefficient of 23 types of available acoustic material in Iran was tested. Reliability of results by three repeat of measurement was tested. Results showed that the standard deviation of sound absorption coefficient of study materials was smaller than .Conclusion: The present study performed a necessary technology of designing and producing of impedance tube for determining of acoustical materials absorption coefficient in Iran.

Study of physical and sound absorbing property of epoxy blended coir dust biocomposite

Science.gov (United States)

Nath, G.; Mishra, S. P.

2016-09-01

Reinforcement biocomposite has gained more attention recently due to its low cost, abundantly availability, low density, specific properties, easy method of separation, enhanced energy recovery, CO2 neutrality, biodegradability and recyclable in nature. As a waste product of coconut fruit, the coconut coir dust (CCD) obtained from the coconut husk. The biocomposite material prepared from the CCD modified with the proper blended solution with the help of ultrasonic technique. The study of adiabatic compressibility of acetone / water (70/30) worth its blending property for bleaching of CCD. The biocomposite material of CCD was prepared with epoxy resin. The different physical properties such as sound absorption coefficient, thermal conductivity and electrical conductivity were measured. The morphological study of biocomposite and measurement of sound absorption coefficient shows good evidence of sound absorbing characteristics of biocomposite of CCD. The sound absorption property of composite material shows a significant result where as the thermal conductivity and electrical conductivity executes a weak result. Thus biocomposite of CCD can acts as a good sound absorber and band conductor of heat and electric current.

Recycling ceramic industry wastes in sound absorbing materials

Directory of Open Access Journals (Sweden)

C. Arenas

2016-10-01

Full Text Available The scope of this investigation is to develop a material mainly composed (80% w/w of ceramic wastes that can be applied in the manufacture of road traffic noise reducing devices. The characterization of the product has been carried out attending to its acoustic, physical and mechanical properties, by measuring the sound absorption coefficient at normal incidence, the open void ratio, density and compressive strength. Since the sound absorbing behavior of a porous material is related to the size of the pores and the thickness of the specimen tested, the influence of the particle grain size of the ceramic waste and the thickness of the samples tested on the properties of the final product has been analyzed. The results obtained have been compared to a porous concrete made of crushed granite aggregate as a reference commercial material traditionally used in similar applications. Compositions with coarse particles showed greater sound absorption properties than compositions made with finer particles, besides presenting better sound absorption behavior than the reference porous concrete. Therefore, a ceramic waste-based porous concrete can be potentially recycled in the highway noise barriers field.

Integrated sound absorption in thermally activated concrete ceilings - acoustic and thermal effectiveness of sound-absorber strips spaced at intervals; Integrierte Schallabsorption in thermisch aktivierten Betondecken - akustische und thermische Wirksamkeit periodischer Schallabsorberstreifen

Energy Technology Data Exchange (ETDEWEB)

Drotleff, Horst; Wack, Roman; Leistner, Philip; Holm, Andreas; Ziegler, Matthias; Sedlbauer, Klaus [Fraunhofer-Institut fuer Bauphysik IBP, Stuttgart (Germany)

2011-10-15

From the perspectives of energy as well as indoor climate, thermally activated concrete ceilings make sense. Used in office buildings, however, their drawback becomes apparent: they are acoustically reflective. The conventional approaches use sound-absorbing suspended sails and absorber baffles or heat-conducting sound absorbers embedded in large areas of the concrete. In this paper, an alternative approach is presented and is evaluated acoustically and thermally. A few strips of sound absorber, arranged at intervals, are mounted flush into the concrete ceiling. To calculate the sound-absorption spectrum, an already widely publicised model (the Rayleigh approach) is used. It predicts the sound-absorption spectrum for normal sound incidence very well. For diffuse sound incidence, the difference to reverberation chamber measurements is greater, presumably because of the edge effect. The sound- absorption coefficient of the design can be tuned by skilful choice of the strip geometry, and it is significantly higher than the expected average value for the surface. On the one hand, the thermal efficiency of the components is determined by comparing the heat fluxes in the ceilings with absorber strips to an untreated reference ceiling. On the other hand, the indoor climate is investigated using a room model for office rooms of both solid and lightweight constructions. The influence of the strips (proportion of absorber area 20 %) on the thermal efficiency and indoor climate is low. Two absorber materials are examined in the strip approach: open-cell foam glass and a micro-perforated metallic absorber. While the metallic absorber displays thermal advantages, its sound absorption spectrum - even at high surface-coverage proportions - exhibits a much lower absorption coefficient than, for example, open-cell foam glass strips with only 20 % ceiling coverage. A demonstration in situ shows the potential of the absorber strips spaced at intervals. However, the method chosen in

Research of Control System and Fault Diagnosis of the Sound-absorbing Board Production Line

Directory of Open Access Journals (Sweden)

Yanjun Xiao

2014-08-01

Full Text Available Programmable Logic Controller is the core of the control system of the sound- absorbing board production line and the design of fault diagnosis is an essential modules in the sound- absorbing board production line. The article discourses the application of PLC in the control system of the production line, and designs the methods of grading treatment and prevention of troubles, which makes use of PLC’S logic functions. The method has good expansibility, and has good guidance to the fault diagnosis in other automation equipments.

Hybrid waste filler filled bio-polymer foam composites for sound absorbent materials

Science.gov (United States)

Rus, Anika Zafiah M.; Azahari, M. Shafiq M.; Kormin, Shaharuddin; Soon, Leong Bong; Zaliran, M. Taufiq; Ahraz Sadrina M. F., L.

2017-09-01

Sound absorption materials are one of the major requirements in many industries with regards to the sound insulation developed should be efficient to reduce sound. This is also important to contribute in economically ways of producing sound absorbing materials which is cheaper and user friendly. Thus, in this research, the sound absorbent properties of bio-polymer foam filled with hybrid fillers of wood dust and waste tire rubber has been investigated. Waste cooking oil from crisp industries was converted into bio-monomer, filled with different proportion ratio of fillers and fabricated into bio-polymer foam composite. Two fabrication methods is applied which is the Close Mold Method (CMM) and Open Mold Method (OMM). A total of four bio-polymer foam composite samples were produce for each method used. The percentage of hybrid fillers; mixture of wood dust and waste tire rubber of 2.5 %, 5.0%, 7.5% and 10% weight to weight ration with bio-monomer. The sound absorption of the bio-polymer foam composites samples were tested by using the impedance tube test according to the ASTM E-1050 and Scanning Electron Microscope to determine the morphology and porosity of the samples. The sound absorption coefficient (α) at different frequency range revealed that the polymer foam of 10.0 % hybrid fillers shows highest α of 0.963. The highest hybrid filler loading contributing to smallest pore sizes but highest interconnected pores. This also revealed that when highly porous material is exposed to incident sound waves, the air molecules at the surface of the material and within the pores of the material are forced to vibrate and loses some of their original energy. This is concluded that the suitability of bio-polymer foam filled with hybrid fillers to be used in acoustic application of automotive components such as dashboards, door panels, cushion and etc.

A Simulation Study on the Performance of Radiant Ceilings Combined with Free-Hanging Horizontal Sound Absorbers

DEFF Research Database (Denmark)

Kazanci, Ongun Berk; Domínguez, L. Marcos; Rage, Niels

2018-01-01

using TABS, most building simulation models assume an uncovered ceiling; however, this might not be the case in practice, due to the use of free-hanging horizontal (or vertical) sound absorbers for the control of room acoustic conditions. The use of sound absorbers will decrease the performance...... of radiant ceiling cooling systems. Therefore, the quantification of the effects during the design phase is important for predicting the resulting thermal indoor environment and for system dimensioning. In this study, a two-person office room equipped with TABS was simulated using a commercially available...... simulation software with a recently developed plug-in that allows simulating the effects of horizontal sound absorbers on the performance of TABS and on the thermal indoor environment. The change in thermal indoor environment and in performance of TABS were quantified, and the simulation results were...

Experimental and Numerical Study of the Effects of Acoustic Sound Absorbers on the Cooling Performance of Thermally Active Building Systems

DEFF Research Database (Denmark)

Domínguez, L. Marcos; Kazanci, Ongun Berk; Rage, Nils

2017-01-01

Free-hanging horizontal and vertical sound absorbers are commonly used in buildings for room acoustic control; however, when these sound absorbers are used in combination with Thermally Active Building Systems, they will decrease the cooling performance of Thermally Active Building Systems...... and this will affect the thermal indoor environment in that space. Therefore, it is crucial to be able to quantify and model these effects in the design phase. This study quantifies experimentally the effects of horizontal and vertical free-hanging sound absorbers on the cooling performance of Thermally Active......%, respectively. With vertical sound absorbers, the decrease in cooling performance was 8%, 12%, and 14% for the corresponding cases, respectively. The numerical model predicted closely the cooling performance reduction, air temperatures and ceiling surface temperatures in most cases, while there were differences...

A numerical comparison between the multiple-scales and finite-element solution for sound propagation in lined flow ducts

NARCIS (Netherlands)

Rienstra, S.W.; Eversman, W.

2001-01-01

An explicit, analytical, multiple-scales solution for modal sound transmission through slowly varying ducts with mean flow and acoustic lining is tested against a numerical finite-element solution solving the same potential flow equations. The test geometry taken is representative of a high-bypass

Thermo-active building systems and sound absorbers: Thermal comfort under real operation conditions

DEFF Research Database (Denmark)

Köhler, Benjamin; Rage, Nils; Chigot, Pierre

2018-01-01

Radiant systems are established today and have a high ecological potential in buildings while ensuring thermal comfort. Free-hanging sound absorbers are commonly used for room acoustic control, but can reduce the heat exchange when suspended under an active slab. The aim of this study...... is to evaluate the impact on thermal comfort of horizontal and vertical free-hanging porous sound absorbers placed in rooms of a building cooled by Thermo-Active Building System (TABS), under real operation conditions. A design comparing five different ceiling coverage ratios and two room types has been...... implemented during three measurement periods. A clear correlation between increase of ceiling coverage ratio and reduction of thermal comfort could not be derived systematically for each measurement period and room type, contrarily to what was expected from literature. In the first two monitoring periods...

Numerical simulation of the effects of hanging sound absorbers on TABS cooling performance

DEFF Research Database (Denmark)

Rage, Nils; Kazanci, Ongun Berk; Olesen, Bjarne W.

2016-01-01

simulating a two-person office of 20 m2, with a typical cooling load of 42 W/m2. The results show that covering 60% of the ceiling surface with sound absorbers hanging at 300 mm from the ceiling active deck is expected to reduce the cooling capacity coefficient of TABS by 15.8%. This drops to 25......Recently there has been a considerable increase in the use of Thermally-Active Building Systems (TABS) in Europe as an energy-efficient and economical cooling and heating solution for buildings. However, this widespread solution requires large uncovered hard surfaces indoors, which can lead...... to a degradation of the room acoustic comfort. Therefore, challenges arise when this system has to be combined with acoustic requirements. Soffit-hanging sound absorbers embody a promising solution. This study focuses on quantifying their impact on the cooling performance of TABS, assessed by means of the cooling...

An investigation of heat transfer augmentation and friction characteristics in solar air heater duct with V-shaped wire as artificial roughness on absorber plate

Energy Technology Data Exchange (ETDEWEB)

Madhukeshwara, N. [Department of Mechanical Engineering, B.I.E.T, Davanagere, Karnataka (India); Prakash, E.S. [Department of Studies in Mechanical Engineering, U.B.D.T.C.E, Davanagere, Karnataka (India)

2013-07-01

An experimental investigation of heat transfer augmentation and friction characteristics of fully developed turbulent flow in a rectangular duct of solar air heater with absorber plate having V-shaped wire ribs as artificial roughness on its underside is carried out. The investigation covers wide range of different parameters of wire ribbed roughness: relative roughness pitch (p/e) from 10 to 40, relative roughness height (e/Dh) from 0.01 to 0.04 and angle of attack of flow from 20° to 90°. Duct aspect ratio (W/B) is kept 5 and Reynolds number (Re) is varied from 2,500 to 8,500. The heat transfer and friction factor values obtained are compared with those of smooth duct under similar flow conditions. Expressions are developed for Nusselt number and friction factor for the roughness geometry. Enhancement of Nusselt number and friction factor for roughened duct are 1.5 and 2.7 times of smooth duct respectively.

Recycling Pig Slurry Solid Fraction Compost as a Sound Absorber

Directory of Open Access Journals (Sweden)

Niccolò Pampuro

2018-01-01

Full Text Available The aim of this investigation was to determine the physical and acoustical properties of compacts made from composted pig slurry solid fraction (SF in order to assess the potential to recycle this agricultural waste as a sound absorber. The compacts were obtained by compression. The physical parameters investigated were bulk density, durability, and particle size distribution. The acoustical features of the compacts were studied with an impedance tube device in order to verify the acoustic absorption coefficient. Two composts were prepared: pig SF compost without a bulking agent (SSFC and pig SF compost with wood chips as a bulking agent (WCC. The study’s results indicated that compost particles dimension played a key role in the physical and acoustical properties of the compacts: the smaller the particles, the higher the physical and acoustical properties of the compacts. The densification process increased the bulk density of the investigated composts up to 690 kg m−3 for SSFC and 660 kg m−3 for WWC, with, respectively, medium (77.9% and low (66.5% durability. The addition of woody bulking agent significantly reduced the absorption coefficient: the best results, in terms of potential use as a sound absorber, were observed for compacts made from composted pig slurry solid fraction without the addition of wood chips.

Application of evolution strategy algorithm for optimization of a single-layer sound absorber

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Morteza Gholamipoor

2014-12-01

Full Text Available Depending on different design parameters and limitations, optimization of sound absorbers has always been a challenge in the field of acoustic engineering. Various methods of optimization have evolved in the past decades with innovative method of evolution strategy gaining more attention in the recent years. Based on their simplicity and straightforward mathematical representations, single-layer absorbers have been widely used in both engineering and industrial applications and an optimized design for these absorbers has become vital. In the present study, the method of evolution strategy algorithm is used for optimization of a single-layer absorber at both a particular frequency and an arbitrary frequency band. Results of the optimization have been compared against different methods of genetic algorithm and penalty functions which are proved to be favorable in both effectiveness and accuracy. Finally, a single-layer absorber is optimized in a desired range of frequencies that is the main goal of an industrial and engineering optimization process.

Noise suppression in duct

International Nuclear Information System (INIS)

Ahmed, A.; Barfeh, M.A.G.

2001-01-01

In air-conditioning system the noise generated by supply fan is carried by conditioned air through the ductwork. The noise created in ductwork run may be transmission, regenerative and ductborne. Transmission noise is fan noise, regenerative noise is due to turbulence in flow and ductborne noise is the noise radiating from duct to surroundings. Some noise is attenuated in ducts also but if noise level is high then it needs to be attenuated. A simple mitre bend can attenuate-noise. This principle is extended to V and M-shape ducts with inside lining of fibreglass, which gave maximum attenuation of 77 dB and 62 dB respectively corresponding to 8 kHz frequency as compared to mitre, bend giving maximum 18 dB attenuation. Sound level meter measured sound levels with octave band filter and tests were conducted in anechoic room. A V-shape attenuator can be used at fan outlet and high frequency noise can be minimized greatly. (author)

The Sound Attenuation Coefficient Optimization in Case of a Three Parameter Impedance Model for a Rectangular 3D Straight Lined Duct of Finite Dimensions

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Stefan BALINT

2015-09-01

Full Text Available A method for the minimization of the ratio of the sound pressure level at the exit to that at the entrance is presented for a rectangular 3D straight lined duct carrying a uniform gas flow. The duct dimensions, the incident sound wave as well as the frequency of the sound wave propagation are assumed to be known. It is assumed also that the liner impedance model is the mass-spring–damper model. The idea is to compute the considered ratio for a large number of combinations of the values of the inertance, resistance and stiffness of the liner and, by fitting the obtained data, to establish a formula for the dependence of the ratio in discussion on these three parameters of the liner. Using the obtained formula, the minimum value of the ratio, as well as the values of the inertance, resistance and stiffness, for which the minimum is obtained, are found.

Design requirement on KALIMER control rod assembly duct

International Nuclear Information System (INIS)

Hwang, W.; Kang, H. Y.; Nam, C.; Kim, J. O.; Kim, Y. J.

1998-03-01

This document establishes the design guidelines which are needs for designing the control rod assembly duct of the KALIMER as design requirements. it describes control rod assembly duct of the KALIMER and its requirements that includes functional requirements, performance requirements, interfacing systems, design limits and strength requirements, seismic requirements, structural requirements, environmental requirements, reliability and safety requirements, standard and codes, QA programs, and other requirements. The control rod system consists of three parts, which are drive mechanism, drive-line, and absorber bundle. This report deals with the absorber bundle and its outer duct only because the others are beyond the scope of fuel system design. The guidelines for design requirements intend to be used for an improved design of the control rod assembly duct of the KALIMER. (author). 19 refs

Design requirement on KALIMER control rod assembly duct

Energy Technology Data Exchange (ETDEWEB)

Hwang, W.; Kang, H. Y.; Nam, C.; Kim, J. O.; Kim, Y. J

1998-03-01

This document establishes the design guidelines which are needs for designing the control rod assembly duct of the KALIMER as design requirements. it describes control rod assembly duct of the KALIMER and its requirements that includes functional requirements, performance requirements, interfacing systems, design limits and strength requirements, seismic requirements, structural requirements, environmental requirements, reliability and safety requirements, standard and codes, QA programs, and other requirements. The control rod system consists of three parts, which are drive mechanism, drive-line, and absorber bundle. This report deals with the absorber bundle and its outer duct only because the others are beyond the scope of fuel system design. The guidelines for design requirements intend to be used for an improved design of the control rod assembly duct of the KALIMER. (author). 19 refs.

Manufacturing Sound Absorber Based on Combined Recycling of Polyethylene Trephetalat and Polystyrene at Low and Median Frequencies

Directory of Open Access Journals (Sweden)

Zeynolabedin Ghanbarzadeh Alamdari

2008-06-01

Full Text Available Background and aim: Noise pollution is one of the main cause of occupational hearing loss. According to WHO reports in many countries workers have been exposed to 85 – 90 dB noise level. The purpose of this study is to manufacture a sound absorber based on combined recycled polyethylene trephetalat (PET and polystyrene (PS with an economical method in order to control of noise Pollution Materials and methods: Sound absorber were made of PET and PS with equal weight percent, polyester fiber, and polyvinyl acetate resine, with five to ten centimeters thick. Sound mean absorption coefficient percents were determined by acoustic impedance tube and compared with those of rock wool. Results: Mean absorption coefficient percent of samples with one to five millimeter pore size and ten centimeters thickness was significantly better than those with six to twenty millimeters pore size in 50 to 630, 1250, and 1600 Hz, (p<0.05. In general, samples mean absorption coehicient was significally different from those rock wool (p=0.005.Conclusion: Recycle polymere absorbers may play an important role in national economics as they are prophylactic to some occupational disease and also are economical.

Normalized inverse characterization of sound absorbing rigid porous media.

Science.gov (United States)

Zieliński, Tomasz G

2015-06-01

This paper presents a methodology for the inverse characterization of sound absorbing rigid porous media, based on standard measurements of the surface acoustic impedance of a porous sample. The model parameters need to be normalized to have a robust identification procedure which fits the model-predicted impedance curves with the measured ones. Such a normalization provides a substitute set of dimensionless (normalized) parameters unambiguously related to the original model parameters. Moreover, two scaling frequencies are introduced, however, they are not additional parameters and for different, yet reasonable, assumptions of their values, the identification procedure should eventually lead to the same solution. The proposed identification technique uses measured and computed impedance curves for a porous sample not only in the standard configuration, that is, set to the rigid termination piston in an impedance tube, but also with air gaps of known thicknesses between the sample and the piston. Therefore, all necessary analytical formulas for sound propagation in double-layered media are provided. The methodology is illustrated by one numerical test and by two examples based on the experimental measurements of the acoustic impedance and absorption of porous ceramic samples of different thicknesses and a sample of polyurethane foam.

The influence of surface modification on sound absorption coefficient of albizzia wood absorber

Science.gov (United States)

Diharjo, Kuncoro; Prabowo, Anditya E.; Jamasri, Suharty, Neng Sri

2017-01-01

The purpose of this research is to investigate the influence of surface modification to sound absorption on absorber based albizia wood and kenaf fiber. The absorber was produced using the albizia wood as main materials, and the kenaf fiber was used as acoustic fill. The albizia wood used for producing the absorber was cut in the transverse direction so that its surface had good porosity. The size of specimens had 100 mm in diameter and 40 mm in thickness. The configuration of resonator cavities was 30 mm in diameter and 20 mm in depth, and each resonator was completed with a neck hole of the resonator. The types of surface modification were the addition of screen printing ink, fabric (with and without neck hole), and vinyl-wallpaper (with and without neck hole). According to ISO 10534-2, the absorber specimens were tested using two microphones impedance tube with random noise source to get the curve of noise absorption coefficient (NAC) for each specimen. The result shows that both unmodified absorber and absorber modified with screen printing ink have the similar characteristic of NAC and they are feasible to be used as an absorber in conversation rooms. The addition of fabric and vinyl-wallpaper as cover on the absorber surface give the positive effect of the air gap, and it increases the NAC in low frequency (100-400 Hz). However, the covers decrease the NAC in high frequency (400-1,400 Hz). The holes on the fabric and wallpaper covers give the improvement of NAC.

Computation of Aerodynamic Noise Radiated from Ducted Tail Rotor Using Boundary Element Method

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Yunpeng Ma

2017-01-01

Full Text Available A detailed aerodynamic performance of a ducted tail rotor in hover has been numerically studied using CFD technique. The general governing equations of turbulent flow around ducted tail rotor are given and directly solved by using finite volume discretization and Runge-Kutta time integration. The calculations of the lift characteristics of the ducted tail rotor can be obtained. In order to predict the aerodynamic noise, a hybrid method combining computational aeroacoustic with boundary element method (BEM has been proposed. The computational steps include the following: firstly, the unsteady flow around rotor is calculated using the CFD method to get the noise source information; secondly, the radiate sound pressure is calculated using the acoustic analogy Curle equation in the frequency domain; lastly, the scattering effect of the duct wall on the propagation of the sound wave is presented using an acoustic thin-body BEM. The aerodynamic results and the calculated sound pressure levels are compared with the known technique for validation. The sound pressure directivity and scattering effect are shown to demonstrate the validity and applicability of the method.

Noise levels in neonatal intensive care unit and use of sound absorbing panel in the isolette.

Science.gov (United States)

Altuncu, E; Akman, I; Kulekci, S; Akdas, F; Bilgen, H; Ozek, E

2009-07-01

The purposes of this study were to measure the noise level of a busy neonatal intensive care unit (NICU) and to determine the effect of sound absorbing panel (SAP) on the level of noise inside the isolette. The sound pressure levels (SPL) of background noise, baby crying, alarms and closing of isolette's door/portholes were measured by a 2235-Brüel&Kjaer Sound Level Meter. Readings were repeated after applying SAP (3D pyramidal shaped open cell polyurethane foam) to the three lateral walls and ceiling of the isolette. The median SPL of background noise inside the NICU was 56dBA and it decreased to 47dBA inside the isolette. The median SPL of monitor alarms and baby crying inside the isolette were not different than SPL measured under radiant warmer (p>0.05). With SAP, the median SPL of temperature alarm inside the isolette decreased significantly from 82 to 72dBA, monitor alarm from 64 to 56dBA, porthole closing from 81 to 74dBA, and isolette door closing from 80 to 68dBA (pnoise produced by baby crying when SAP was used in the isolette (79dBA vs 69dBA, respectively) (pnoise. The noise level in our NICU is significantly above the universally recommended levels. Being inside the isolette protects infants from noise sources produced outside the isolette. However, very high noises are produced inside the isolette as well. Sound absorbing panel can be a simple solution and it attenuated the noise levels inside the isolette.

Study on The Effectiveness of Egg Tray and Coir Fibre as A Sound Absorber

Science.gov (United States)

Kaamin, Masiri; Farah Atiqah Ahmad, Nor; Ngadiman, Norhayati; Kadir, Aslila Abdul; Razali, Siti Nooraiin Mohd; Mokhtar, Mardiha; Sahat, Suhaila

2018-03-01

Sound or noise pollution has become one major issues to the community especially those who lived in the urban areas. It does affect the activity of human life. This excessive noise is mainly caused by machines, traffic, motor vehicles and also any unwanted sounds that coming from outside and even from the inside of the building. Such as a loud music. Therefore, the installation of sound absorption panel is one way to reduce the noise pollution inside a building. The selected material must be a porous and hollow in order to absorb high frequency sound. This study was conducted to evaluate the potential of egg tray and coir fibre as a sound absorption panel. The coir fibre has a good coefficient value which make it suitable as a sound absorption material and can replace the traditional material; syntactic and wooden material. The combination of pyramid shape of egg tray can provide a large surface for uniform sound reflection. This study was conducted by using a panel with size 1 m x 1 m with a thickness of 6 mm. This panel consist of egg tray layer, coir fibre layer and a fabric as a wrapping for the aesthetic value. Room reverberation test has been carried to find the loss of reverberation time (RT). Result shows that, a reverberation time reading is on low frequency, which is 125 Hz to 1600 Hz. Within these frequencies, this panel can shorten the reverberation time of 5.63s to 3.60s. Hence, from this study, it can be concluded that the selected materials have the potential as a good sound absorption panel. The comparison is made with the previous research that used egg tray and kapok as a sound absorption panel.

Study on The Effectiveness of Egg Tray and Coir Fibre as A Sound Absorber

Directory of Open Access Journals (Sweden)

Kaamin Masiri

2018-01-01

Full Text Available Sound or noise pollution has become one major issues to the community especially those who lived in the urban areas. It does affect the activity of human life. This excessive noise is mainly caused by machines, traffic, motor vehicles and also any unwanted sounds that coming from outside and even from the inside of the building. Such as a loud music. Therefore, the installation of sound absorption panel is one way to reduce the noise pollution inside a building. The selected material must be a porous and hollow in order to absorb high frequency sound. This study was conducted to evaluate the potential of egg tray and coir fibre as a sound absorption panel. The coir fibre has a good coefficient value which make it suitable as a sound absorption material and can replace the traditional material; syntactic and wooden material. The combination of pyramid shape of egg tray can provide a large surface for uniform sound reflection. This study was conducted by using a panel with size 1 m x 1 m with a thickness of 6 mm. This panel consist of egg tray layer, coir fibre layer and a fabric as a wrapping for the aesthetic value. Room reverberation test has been carried to find the loss of reverberation time (RT. Result shows that, a reverberation time reading is on low frequency, which is 125 Hz to 1600 Hz. Within these frequencies, this panel can shorten the reverberation time of 5.63s to 3.60s. Hence, from this study, it can be concluded that the selected materials have the potential as a good sound absorption panel. The comparison is made with the previous research that used egg tray and kapok as a sound absorption panel.

The Use of Sound Absorbing Shading Systems for the Attenuation of Noise on Building Façades. An Experimental Investigation

Directory of Open Access Journals (Sweden)

Nicolò Zuccherini Martello

2015-12-01

Full Text Available The problem of solar irradiation in building façades with large windows is often solved with the use of external shading devices, such as brise-soleil systems, but their potential acoustic effects on building façades are usually neglected. The purpose of this work is a preliminary consideration of the acoustic behaviour of brise-soleil systems and, furthermore, the evaluation of the possibility to improve their performances, in terms of Sound Pressure Level (SPL abatement over glass surfaces. The paper reports the results of a study on two portions of the same office building, with shading devices installed in front of large windows. Both airborne sound insulation measurements and SPL measurements over the glass surfaces of the windows were carried out to compare different situations, with or without louvers, and with sound absorbing experimental louvers as well. Results show that the louvers' presence can produce an increase in the SPL over the glass surface as a consequence of the reflection of the sound. Results further show that sound absorbing louvers improve the noise protection of the system, in terms of the SPL reduction, over glass surfaces, cancelling out the negative effect of the standard shading devices.

Ducting Conditions for Electromagnetic Wave Propagation in Tropical Disturbances from GPS Dropsonde Data

Science.gov (United States)

2013-12-01

depression, tropical storm , hurricane, extratropical cyclone, subtropical depression, subtropical storm , a low of no category, tropical wave, disturbance or...surface-based ducts, and elevated ducts. We further separate the duct occurrence based on the location relative to their respective storms . Based...on the number of soundings in different types of tropical disturbances, we chose to further analyze duct conditions in hurricanes and tropical storms

Analysis of sound absorption performance of an electroacoustic absorber using a vented enclosure

Science.gov (United States)

Cho, Youngeun; Wang, Semyung; Hyun, Jaeyub; Oh, Seungjae; Goo, Seongyeol

2018-03-01

The sound absorption performance of an electroacoustic absorber (EA) is primarily influenced by the dynamic characteristics of the loudspeaker that acts as the actuator of the EA system. Therefore, the sound absorption performance of the EA is maximum at the resonance frequency of the loudspeaker and tends to degrade in the low-frequency and high-frequency bands based on this resonance frequency. In this study, to adjust the sound absorption performance of the EA system in the low-frequency band of approximately 20-80 Hz, an EA system using a vented enclosure that has previously been used to enhance the radiating sound pressure of a loudspeaker in the low-frequency band, is proposed. To verify the usefulness of the proposed system, two acoustic environments are considered. In the first acoustic environment, the vent of the vented enclosure is connected to an external sound field that is distinct from the sound field coupled to the EA. In this case, the acoustic effect of the vented enclosure on the performance of the EA is analyzed through an analytical approach using dynamic equations and an impedance-based equivalent circuit. Then, it is verified through numerical and experimental approaches. Next, in the second acoustic environment, the vent is connected to the same external sound field as the EA. In this case, the effect of the vented enclosure on the EA is investigated through an analytical approach and finally verified through a numerical approach. As a result, it is confirmed that the characteristics of the sound absorption performances of the proposed EA system using the vented enclosure in the two acoustic environments considered in this study are different from each other in the low-frequency band of approximately 20-80 Hz. Furthermore, several case studies on the change tendency of the performance of the EA using the vented enclosure according to the critical design factors or vent number for the vented enclosure are also investigated. In the future

Multimodal method for scattering of sound at a sudden area expansion in a duct with subsonic flow

Science.gov (United States)

Kooijman, G.; Testud, P.; Aurégan, Y.; Hirschberg, A.

2008-03-01

The scattering of sound at a sudden area expansion in a duct with subsonic mean flow has been modelled with a multimodal method. Technological applications are for instance internal combustion engine exhaust silencers and silencers in industrial duct systems. Both two-dimensional (2D) rectangular and 2D cylindrical geometry and uniform mean flow as well as non-uniform mean flow profiles are considered. Model results for the scattering of plane waves in case of uniform flow, in which case an infinitely thin shear layer is formed downstream of the area expansion, are compared to results obtained by other models in literature. Generally good agreement is found. Furthermore, model results for the scattering are compared to experimental data found in literature. Also here fairly good correspondence is observed. When employing a turbulent pipe flow profile in the model, instead of a uniform flow profile, the prediction for the downstream transmission- and upstream reflection coefficient is improved. However, worse agreement is observed for the upstream transmission and downstream reflection coefficient. On the contrary, employing a non-uniform jet flow profile, which represents a typical shear layer flow downstream of the expansion, gives worse agreement for the downstream transmission- and the upstream reflection coefficient, whereas prediction for the upstream transmission and downstream reflection coefficient improves.

A non-local computational boundary condition for duct acoustics

Science.gov (United States)

Zorumski, William E.; Watson, Willie R.; Hodge, Steve L.

1994-01-01

A non-local boundary condition is formulated for acoustic waves in ducts without flow. The ducts are two dimensional with constant area, but with variable impedance wall lining. Extension of the formulation to three dimensional and variable area ducts is straightforward in principle, but requires significantly more computation. The boundary condition simulates a nonreflecting wave field in an infinite duct. It is implemented by a constant matrix operator which is applied at the boundary of the computational domain. An efficient computational solution scheme is developed which allows calculations for high frequencies and long duct lengths. This computational solution utilizes the boundary condition to limit the computational space while preserving the radiation boundary condition. The boundary condition is tested for several sources. It is demonstrated that the boundary condition can be applied close to the sound sources, rendering the computational domain small. Computational solutions with the new non-local boundary condition are shown to be consistent with the known solutions for nonreflecting wavefields in an infinite uniform duct.

Bile Duct Anastomosis Supplied With Biodegradable Stent in Liver Transplantation: The Initial Experience.

Science.gov (United States)

Janousek, L; Maly, S; Oliverius, M; Kocik, M; Kucera, M; Fronek, J

2016-12-01

The most common biliary complications after orthotopic liver transplantation are bile leaks, anastomotic and intrahepatic strictures, stones, and ampullary dysfunction. These complications can occur in up to 10% to 30% of liver transplant recipients. Leaks occur early in the posttransplant period; the stricture formation typically graduates over time. Ten patients underwent transplantation in our preliminary study: 5 were randomized to the group with stent placement and 5 to the control group. We investigated the role of an absorbable biliary stent with the goal of proving patency of duct-to-duct biliary anastomosis. The stents are made of machine-knitted polydioxanone monofilaments. Our initial results show that duct-to-duct biliary reconstruction using an absorbable internal stent had good patency in all 5 patients. There were no signs of biliary leakage accompanying the anastomoses in any of the cases, and there was no stone formation observed after liver transplantation. The biliary stent was completely absorbed, with no adverse effects. Based on our initial experience and data, we concluded that biodegradable stents can be successfully and safely used in clinical practice. Further large prospective randomized studies are needed to estimate the efficacy of the bioabsorbable stents. Copyright © 2016 Elsevier Inc. All rights reserved.

Exhaust sound absorbers for all kinds of applications. Preventing heating noise; Abgasschalldaempfer fuer alle Faelle. Stoerende Heizungsgeraeusche verhindern

Energy Technology Data Exchange (ETDEWEB)

Paul-Faerber, M. [Buero fuer Presse- und Oeffentlichkeitsarbeit Dieter Last, Osnabrueck (Germany)

2007-12-15

Noise is considered a nuisance not only on the basis of its level and duration but also depending on the type of noise. For example, the hum of big heating boilers or cogerneration units is considered particularly noisome. Noise reduction measures therefore should be taken already in the projecting stage, e.g. by installing sound absorbers. (orig.)

Microstructure representations for sound absorbing fibrous media: 3D and 2D multiscale modelling and experiments

Science.gov (United States)

Zieliński, Tomasz G.

2017-11-01

The paper proposes and investigates computationally-efficient microstructure representations for sound absorbing fibrous media. Three-dimensional volume elements involving non-trivial periodic arrangements of straight fibres are examined as well as simple two-dimensional cells. It has been found that a simple 2D quasi-representative cell can provide similar predictions as a volume element which is in general much more geometrically accurate for typical fibrous materials. The multiscale modelling allowed to determine the effective speeds and damping of acoustic waves propagating in such media, which brings up a discussion on the correlation between the speed, penetration range and attenuation of sound waves. Original experiments on manufactured copper-wire samples are presented and the microstructure-based calculations of acoustic absorption are compared with the corresponding experimental results. In fact, the comparison suggested the microstructure modifications leading to representations with non-uniformly distributed fibres.

Sound Control in the Physic Lab in the Polyacryl Company and Studying the Noise Reduction by Means of Different Absorbents

Directory of Open Access Journals (Sweden)

Harandi

1999-03-01

Full Text Available Studying noise effect at the workplace has more various aspects than other factors. So it is not surprising that its adverse impact on the physical and mental state of the society has been detected to some extent. There is a significant correlation between the hearing loss and the noise pollution of the workplaces. The most important ways to lessen and control the impact of noise are: substituting the noisy equipments with ones that produce less noise, correcting noise sources and isolating the sound source. In the current study we tried to control the noise level by using various sound absorbents and measured sound level by using these different substances. The results of these measurements have reported in the current article in details.

Performance Study of Solar Air Heater Having Absorber Plate with Half-Perforated Baffles

OpenAIRE

Maheshwari, B. K.; Karwa, Rajendra; Gharai, S. K.

2011-01-01

The paper presents a detailed mathematical model for performance prediction of a smooth duct solar air heater validated against the experimental results. Experimental study on a solar air heater having absorber plate with half-perforated baffles on the air flow side shows thermal efficiency enhancement of 28%–45% over that of the smooth duct solar air heater, which is attributed to the heat transfer enhancement (of the order of 180%–235%) due to the perforated baffles attached to the absorber...

Performance analysis of solar air heater with jet impingement on corrugated absorber plate

Directory of Open Access Journals (Sweden)

Alsanossi M. Aboghrara

2017-09-01

Full Text Available This paper deals with the experimental investigation outlet temperature and efficiency, of Solar Air heater (SAH. The experimental test set up designed and fabricated to study the effect of jet impingement on the corrugated absorber plate, through circular jets in a duct flow of solar air heater, and compared with conventional solar air heater on flat plat absorber. Under effect of mass flow rate (ṁ of air and solar radiation on outlet air temperature, and efficiency, are analyzed. Results show the flow jet impingement on corrugated plat absorber is a strong function of heat transfer enhancement. The present investigation concludes that the mass flow rate of air substantially influences the heat transfer on solar air heaters. And the thermal efficiency of proposed design duct is observed almost 14% more as compare to the smooth duct. At solar radiation 500–1000 (W/M2, 308 K ambient temperature and 0.01–0.03 (Kg/S mass flow rate

Optical architecture design for detection of absorbers embedded in visceral fat.

Science.gov (United States)

Francis, Robert; Florence, James; MacFarlane, Duncan

2014-05-01

Optically absorbing ducts embedded in scattering adipose tissue can be injured during laparoscopic surgery. Non-sequential simulations and theoretical analysis compare optical system configurations for detecting these absorbers. For absorbers in deep scattering volumes, trans-illumination is preferred instead of diffuse reflectance. For improved contrast, a scanning source with a large area detector is preferred instead of a large area source with a pixelated detector.

Acoustic characterization of a nonlinear vibroacoustic absorber at low frequencies and high sound levels

Science.gov (United States)

Chauvin, A.; Monteil, M.; Bellizzi, S.; Côte, R.; Herzog, Ph.; Pachebat, M.

2018-03-01

A nonlinear vibroacoustic absorber (Nonlinear Energy Sink: NES), involving a clamped thin membrane made in Latex, is assessed in the acoustic domain. This NES is here considered as an one-port acoustic system, analyzed at low frequencies and for increasing excitation levels. This dynamic and frequency range requires a suitable experimental technique, which is presented first. It involves a specific impedance tube able to deal with samples of sufficient size, and reaching high sound levels with a guaranteed linear response thank's to a specific acoustic source. The identification method presented here requires a single pressure measurement, and is calibrated from a set of known acoustic loads. The NES reflection coefficient is then estimated at increasing source levels, showing its strong level dependency. This is presented as a mean to understand energy dissipation. The results of the experimental tests are first compared to a nonlinear viscoelastic model of the membrane absorber. In a second step, a family of one degree of freedom models, treated as equivalent Helmholtz resonators is identified from the measurements, allowing a parametric description of the NES behavior over a wide range of levels.

A statistical method for predicting sound absorbing property of porous metal materials by using quartet structure generation set

International Nuclear Information System (INIS)

Guan, Dong; Wu, Jiu Hui; Jing, Li

2015-01-01

Highlights: • A random internal morphology and structure generation-growth method, termed as the quartet structure generation set (QSGS), has been utilized based on the stochastic cluster growth theory for numerical generating the various microstructures of porous metal materials. • Effects of different parameters such as thickness and porosity on sound absorption performance of the generated structures are studied by the present method, and the obtained results are validated by an empirical model as well. • This method could be utilized to guide the design and fabrication of the sound-absorption porous metal materials. - Abstract: In this paper, a statistical method for predicting sound absorption properties of porous metal materials is presented. To reflect the stochastic distribution characteristics of the porous metal materials, a random internal morphology and structure generation-growth method, termed as the quartet structure generation set (QSGS), has been utilized based on the stochastic cluster growth theory for numerical generating the various microstructures of porous metal materials. Then by using the transfer-function approach along with the QSGS tool, we investigate the sound absorbing performance of porous metal materials with complex stochastic geometries. The statistical method has been validated by the good agreement among the numerical results for metal rubber from this method and a previous empirical model and the corresponding experimental data. Furthermore, the effects of different parameters such as thickness and porosity on sound absorption performance of the generated structures are studied by the present method, and the obtained results are validated by an empirical model as well. Therefore, the present method is a reliable and robust method for predicting the sound absorption performance of porous metal materials, and could be utilized to guide the design and fabrication of the sound-absorption porous metal materials

Facile Synthesis of Flexible Methylsilsesquioxane Aerogels with Surface Modifications for Sound- Absorbance, Fast Dye Adsorption and Oil/Water Separation

Directory of Open Access Journals (Sweden)

Xingzhong Guo

2018-04-01

Full Text Available New flexible methylsilsesquioxane (MSQ aerogels have been facilely prepared by a sol–gel process with methyltrimethoxysilane (MTMS and dimethyldimethoxysilane (DMDMS as co-precursors, followed by surface modification and ambient pressure drying. The microstructure, mechanical properties and hydrophobicity of these MSQ aerogels after surface modifications of hexamethyldisiloxane (HMDSO and/or hexamethyldisilazane (HMDS were investigated in detail, and the applications of surface-modified MSQ aerogels in sound-absorbance, fast dye adsorption and oil/water separation were evaluated, respectively. The MSQ aerogels surface-modified by HMDS possess flexibility, elasticity and superhydrophobicity, and demonstrate good performance in the mentioned applications. The resultant MSQ aerogel used in sound-absorbance has high frequency (about 6 kHz acoustic absorptivity of up to 80%, benefiting from its macroporous structure and porosity of 94%, and it also possesses intermediate frequency acoustic absorptivity (about 1 kHz up to 80% owing to its elasticity. This MSQ aerogel can selectively separate oil from oil/water mixtures with high efficiency due to its superhydrophobicity and superlipophilicity, resulting from a lot of methyl groups, density as low as 0.12 cm3·g−1 and a water contact angle as high as 157°. This MSQ aerogel can be assembled to be a monolithic column applied for fast dye adsorption, and shows selective adsorption for anionic dyes and removal efficiency of methyl orange of up to 95%.

The impact of duct-to-duct interaction on the hex duct dilation

International Nuclear Information System (INIS)

Lee, M.J.; Chang, L.K.; Lahm, C.E.; Porter, D.L.

1992-01-01

Dilation of the hex duct is an important factor in the operational lifetime of fuel subassemblies in liquid metal fast reactors. It is caused primarily by the irradiation-enhanced creep and void swelling of the hex duct material. Excessive dilation may jeopardize subassembly removal from the core or cause a subassembly storage problem where the grid size of the storage basket is limited. Dilation of the hex duct in Experimental Breeder Reactor II (EBR-II) limits useful lifetime because of these storage basket limitations. It is, therefore, important to understand the hex duct dilation behavior to guide the design and in-core management of fuel subassemblies in a way that excessive duct deformation can be avoided. To investigate the dilation phenomena, finite-element models of the hex duct have been developed. The inelastic analyses were performed using the structural analysis code, ANSYS. Both Type 316 and D9 austenitic stainless steel ducts are considered. The calculated dilations are in good agreement with profilometry measurements made after irradiation. The analysis indicates that subassembly interaction is an important parameter in addition to neutron fluence and temperature in determining hex duct dilation. 5 refs

Acoustic Power Transmission Through a Ducted Fan

Science.gov (United States)

Envia, Ed

2016-01-01

For high-speed ducted fans, when the rotor flowfield is shock-free, the main contribution to the inlet radiated acoustic power comes from the portion of the rotor stator interaction sound field that is transmitted upstream through the rotor. As such, inclusion of the acoustic transmission is an essential ingredient in the prediction of the fan inlet noise when the fan tip relative speed is subsonic. This paper describes a linearized Euler based approach to computing the acoustic transmission of fan tones through the rotor. The approach is embodied in a code called LINFLUX was applied to a candidate subsonic fan called the Advanced Ducted Propulsor (ADP). The results from this study suggest that it is possible to make such prediction with sufficient fidelity to provide an indication of the acoustic transmission trends with the fan tip speed.

Acoustic propagation within a surface duct in the western Bay of Bengal

Digital Repository Service at National Institute of Oceanography (India)

PrasannaKumar, S.; Navelkar, G.S.; Murty, T.V.R.; Murty, C.S.

Sound speed structure forms a surface duct in the upper 50 m layer in the western Bay of Bengal during late July. A range-dependent acoustic ray computation shows that some rays emanating from a source within the upper 30 m, get trapped within...

Strip-coat decontamination of ducting interiors with SEAMIST trademark -safe and fast

International Nuclear Information System (INIS)

Keller, C.

1994-01-01

The SEAMIST trademark system was invented for sampling and instrumentation of boreholes. However, the SEAMIST trademark pneumatically driven everting membrane has the ability to install absorbent liner materials for wicking and recovery of hazardous fluids (e.g., PCB'S) from ducting. The most useful vent cleaning technique is the installation of a stripcoat saturated duct liner which is then peeled from the liner retrieving contaminated particles (e. g., uranium, plutonium,...), much like the stripcoat which is used to clean glove boxes. Because of the everting SEAMIST trademark hole liner's ability to traverse ducting of many combinations of diameters, slope, turns, and obstructions, the stripcoat application method is exceptionally fast, (>10 ft/min.). This paper describes the method of installation, the prototype tests, the science, and the first results of a full scale test. This unusual method of cleaning ducting results in major advantages in safety, cost, and speed of the cleaning process. Comparisons are made with the traditional methods of sand blasting and washing. Additional benefits of the method are the ability to assess the distribution of the contamination of the ducting and to also use the everting membrane for a video camera examination of the cleaned duct coupled with contamination sensors, such as radiation logging tools. The technique can be extended to clean all manner of contamination in ducting such as microbial residues in hospitals. Very large ducts (12--120 inch dia.), are especially easily cleaned while still in place in the building

First- and Second-level Bayesian Inference of Flow Resistivity of Sound Absorber and Room’s Influence

DEFF Research Database (Denmark)

Choi, Sang-Hyeon; Lee, Ikjin; Jeong, Cheol-Ho

2016-01-01

Sabine absorption coefficient is a widely used one deduced from reverberation time measurements via the Sabine equation. First- and second-level Bayesian analysis are used to estimate the flow resistivity of a sound absorber and the influences of the test chambers from Sabine absorption...... coefficients measured in 13 different reverberation chambers. The first-level Bayesian analysis is more general than the second-level Bayesian analysis. Sharper posterior distribution can be acquired by the second-level Bayesian analysis than the one by the first-level Bayesian analysis because more data...... are used to set more reliable prior distribution. The estimated room’s influences by the first- and the second-level Bayesian analyses are similar to the estimated results by the mean absolute error minimization....

Sound absorption coefficient of coal bottom ash concrete for railway application

Science.gov (United States)

Ramzi Hannan, N. I. R.; Shahidan, S.; Maarof, Z.; Ali, N.; Abdullah, S. R.; Ibrahim, M. H. Wan

2017-11-01

A porous concrete able to reduce the sound wave that pass through it. When a sound waves strike a material, a portion of the sound energy was reflected back and another portion of the sound energy was absorbed by the material while the rest was transmitted. The larger portion of the sound wave being absorbed, the lower the noise level able to be lowered. This study is to investigate the sound absorption coefficient of coal bottom ash (CBA) concrete compared to the sound absorption coefficient of normal concrete by carried out the impedance tube test. Hence, this paper presents the result of the impedance tube test of the CBA concrete and normal concrete.

Sound radiation contrast in MR phase images. Method for the representation of elasticity, sound damping, and sound impedance changes

International Nuclear Information System (INIS)

Radicke, Marcus

2009-01-01

The method presented in this thesis combines ultrasound techniques with the magnetic-resonance tomography (MRT). An ultrasonic wave generates in absorbing media a static force in sound-propagation direction. The force leads at sound intensities of some W/cm 2 and a sound frequency in the lower MHz range to a tissue shift in the micrometer range. This tissue shift depends on the sound power, the sound frequency, the sound absorption, and the elastic properties of the tissue. A MRT sequence of the Siemens Healthcare AG was modified so that it measures (indirectly) the tissue shift, codes as grey values, and presents as 2D picture. By means of the grey values the sound-beam slope in the tissue can be visualized, and so additionally sound obstacles (changes of the sound impedance) can be detected. By the MRT images token up spatial changes of the tissue parameters sound absorption and elasticity can be detected. In this thesis measurements are presented, which show the feasibility and future chances of this method especially for the mammary-cancer diagnostics. [de

Inversion for atmosphere duct parameters using real radar sea clutter

International Nuclear Information System (INIS)

Sheng Zheng; Fang Han-Xian

2012-01-01

This paper addresses the problem of estimating the lower atmospheric refractivity (M profile) under nonstandard propagation conditions frequently encountered in low altitude maritime radar applications. The vertical structure of the refractive environment is modeled using five parameters and the horizontal structure is modeled using five parameters. The refractivity model is implemented with and without a priori constraint on the duct strength as might be derived from soundings or numerical weather-prediction models. An electromagnetic propagation model maps the refractivity structure into a replica field. Replica fields are compared with the observed clutter using a squared-error objective function. A global search for the 10 environmental parameters is performed using genetic algorithms. The inversion algorithm is implemented on the basis of S-band radar sea-clutter data from Wallops Island, Virginia (SPANDAR). Reference data are from range-dependent refractivity profiles obtained with a helicopter. The inversion is assessed (i) by comparing the propagation predicted from the radar-inferred refractivity profiles with that from the helicopter profiles, (ii) by comparing the refractivity parameters from the helicopter soundings with those estimated. This technique could provide near-real-time estimation of ducting effects. (geophysics, astronomy, and astrophysics)

Vibroacoustic study of a point-constrained plate mounted in a duct

Science.gov (United States)

Sapkale, Swapnil L.; Sucheendran, Mahesh M.; Gupta, Shakti S.; Kanade, Shantanu V.

2018-04-01

The vibroacoustic study of the interaction of sound with a point-constrained, simply-supported square plate is considered in this paper. The plate is mounted flush on one of the walls of an infinite duct of rectangular cross section and is backed by a cavity. The plate response and the acoustic field is predicted by solving the coupled governing equations using modal expansion with the relevant eigenmodes of the plate dynamics and acoustic fields in the duct and cavity. By varying the location of the point constraint, the frequency characteristics of the transmission loss in the duct can be tuned. The point constraint can also alter the amplitude and spectral characteristics of the plate's response. Interestingly, some new peaks are observed in the response because of the excitation of unsymmetric modes which are otherwise dormant. Mode-localization phenomenon, which is the localization of vibration in specific regions of the plate, is observed for selected constrained points.

Factors affecting sound energy absorbance in acute otitis media model of chinchilla.

Science.gov (United States)

Guan, Xiying; Seale, Thomas W; Gan, Rong Z

2017-07-01

Acute otitis media (AOM) is a rapid-onset infection of the middle ear which results in middle ear pressure (MEP), middle ear effusion (MEE), and structural changes in middle ear tissues. Previous studies from our laboratory have identified that MEP, MEE, and middle ear structural changes are three factors affecting tympanic membrane (TM) mobility and hearing levels (Guan et al., 2014, 2013). Sound energy reflectance or absorbance (EA) is a diagnostic tool increasingly used in clinical settings for the identification of middle ear diseases. However, it is unclear whether EA can differentiate these three factors in an AOM ear. Here we report wideband EA measurements in the AOM model of chinchilla at three experimental stages: unopened, pressure released, and effusion removed. These correspond to the combined and individual effects of the three factors on sound energy transmission. AOM was produced by transbullar injection of Haemophilus influenzae in two treatment groups: 4 days (4D) and 8 days (8D) post inoculation. These time points represent the relatively early and later phase of AOM. In each group of chinchillas, EA at 250-8000 Hz was measured using a wideband tympanometer at three experimental stages. Results show that the effects of MEP, MEE, and tissue structural changes over the frequency range varied with the disease time course. MEP was the primary contributor to reduction of EA in 4D AOM ears and had a smaller effect in 8D ears. MEE reduced the EA at 6-8 kHz in 4D ears and 2-8 kHz in 8D ears and was responsible for the EA peak in both 4D and 8D ears. The residual EA loss due to structural changes was observed over the frequency range in 8D ears and only at high frequencies in 4D ears. The EA measurements were also compared with the published TM mobility loss in chinchilla AOM ears. Copyright © 2017 Elsevier B.V. All rights reserved.

Performance Analysis of a Shallow Duct Flat Plate Solar Air Heater with and without Porous Media

Directory of Open Access Journals (Sweden)

Haroun A.K. Shahad

2016-12-01

Full Text Available In this study a flat plate solar air heater with a shallow duct is analyzed experimentally. The collector consists of a 4.5m long air duct with a (20×5cm cross-sectional area. The air duct consists of four channels so that the collector becomes more compact. The collector is studied under the weather conditions of Hilla city – Iraq with latitude and longitude equal 32.3° N and 44.25° E respectively and it is tilted by 45° with the horizontal plane. The effect of the air mass flow rate on the collector performance is also studied.The performance of the collector is analyzed with and without porous media stuffing. The measured parameters are the air and absorber temperatures, air speed and pressure drop. The temperatures are measured by means of type (K thermocouples as this type covers the temperature range of the studied system. The values of the temperature are displayed by temperature data logger devices. The air speed and pressure drop are measured by digital anemometer and manometer devices respectively. The results of the studied system show that as the air mass flow rate increases, the temperature of both the flowing air and the absorber decrease, whilst the efficiency of the collector increases. The results also show that the addition of the steel wool porous material inside the air duct increases the temperature of both the flowing air and the absorber, and by that increases the efficiency of the collector. The porous media also caused an increase in the pressure drop between the outlet air and the atmosphere. This pressure drop increased with the increase in the air mass flow rate

Recent Advances in the Sound Insulation Properties of Bio-based Materials

Directory of Open Access Journals (Sweden)

Xiaodong Zhu

2013-12-01

Full Text Available Many bio-based materials, which have lower environmental impact than traditional synthetic materials, show good sound absorbing and sound insulation performances. This review highlights progress in sound transmission properties of bio-based materials and provides a comprehensive account of various multiporous bio-based materials and multilayered structures used in sound absorption and insulation products. Furthermore, principal models of sound transmission are discussed in order to aid in an understanding of sound transmission properties of bio-based materials. In addition, the review presents discussions on the composite structure optimization and future research in using co-extruded wood plastic composite for sound insulation control. This review contributes to the body of knowledge on the sound transmission properties of bio-based materials, provides a better understanding of the models of some multiporous bio-based materials and multilayered structures, and contributes to the wider adoption of bio-based materials as sound absorbers.

Bile Duct Exploration

Science.gov (United States)

... Home / Health Library / Diagnostics & Testing / Bile Duct Exploration Bile Duct Exploration Common bile duct exploration is a ... Test Details Results and Follow-Up What is bile, and what is bile duct exploration? Bile is ...

Rice straw-wood particle composite for sound absorbing wooden construction materials.

Science.gov (United States)

Yang, Han-Seung; Kim, Dae-Jun; Kim, Hyun-Joong

2003-01-01

In this study, rice straw-wood particle composite boards were manufactured as insulation boards using the method used in the wood-based panel industry. The raw material, rice straw, was chosen because of its availability. The manufacturing parameters were: a specific gravity of 0.4, 0.6, and 0.8, and a rice straw content (10/90, 20/80, and 30/70 weight of rice straw/wood particle) of 10, 20, and 30 wt.%. A commercial urea-formaldehyde adhesive was used as the composite binder, to achieve 140-290 psi of bending modulus of rupture (MOR) with 0.4 specific gravity, 700-900 psi of bending MOR with 0.6 specific gravity, and 1400-2900 psi of bending MOR with a 0.8 specific gravity. All of the composite boards were superior to insulation board in strength. Width and length of the rice straw particle did not affect the bending MOR. The composite boards made from a random cutting of rice straw and wood particles were the best and recommended for manufacturing processes. Sound absorption coefficients of the 0.4 and 0.6 specific gravity boards were higher than the other wood-based materials. The recommended properties of the rice straw-wood particle composite boards are described, to absorb noises, preserve the temperature of indoor living spaces, and to be able to partially or completely substitute for wood particleboard and insulation board in wooden constructions.

Alteration of gastrointestinal transit time in the rat after bile duct cannulation surgery

International Nuclear Information System (INIS)

Ayres, P.H.; Medinsky, M.A.; Muggenburg, B.A.; Bond, J.A.

1985-01-01

Alteration of gastrointestinal (GI) transit time could affect the bioavailability of a toxicant if the toxicant is absorbed in the GI tract. The effect of surgery on GI transit time was investigated using radiographic imaging of barium during passage through the GI tract of the rat. Bile duct cannulation surgery delayed transit of barium to over 18 h, whereas in the normal animal, transit required approximately 6 h. GI transit time was only moderately affected by laparotomy after an 18-h postsurgery recovery period. These results suggest that the gastrointestinal absorption of orally administered toxicants could be affected by bile duct cannulation. 3 references, 1 figure, 1 table

Pipe/duct system design for tornado missile impact loads

Energy Technology Data Exchange (ETDEWEB)

Li, J.; Wang, S.; Johnson, W., E-mail: whjohnso@bechtel.com

2014-04-01

For nuclear power plant life extension projects, it may be convenient and in some instances necessary to locate safety-related steel ducts and pipes outside of the main structures, exposing them to extreme environmental loads such as tornado missile impact. Examples of this application include emergency firewater lines and Control Room vent ducts. A typical exposed commodity run could be comprised of a rectangular or circular cross-section with horizontal and vertical segments supported at variable spans off of roof and wall panels, respectively. Efficient and economical design of such a tornado-impacted duct or pipe system, consisting of the commodity and its supports, must exploit all of the system's capability to absorb the impact energy by deforming plastically to the fullest extent allowable. Energy can be absorbed locally in the vicinity of impact on the commodity, globally through rotation at flexural plastic hinges, and through yielding of the supports. In this paper a simplified NDOF lumped parameter nonlinear analysis methodology is presented and applied to the coupled commodity/support system subjected to tornado impulse loading. The analysis methodology is confirmed using a detailed ANSYS nonlinear finite element model. Optimization of the initial trial design is achieved by progressively decreasing the support resistances, while monitoring the response ductilities throughout the system. Evaluation methodologies are provided for the four types of plastic deformation responses which occur in the system: local response in the immediate vicinity of impact, flexural and membrane response of the sidewall out to one or two times the commodity depth beyond the point of impact, global response of the commodity as a beam spanning between supports, and the shear and flexural response of support. The inelastic responses are evaluated against AISC N690 acceptance criteria (ANSI, 2006), supplemented as appropriate by triaxiality considerations for inelastic

Sound-proof Sandwich Panel Design via Metamaterial Concept

Science.gov (United States)

Sui, Ni

the core material maintains the mechanical property and yields a sound transmission loss that is consistently greater than 50 dB at low frequencies. Furthermore, the absorption property of the proposed honeycomb sandwich panel was experimentally studied. The honeycomb sandwich panel shows an excellent sound absorbing performance at high frequencies by using reinforced glass fiber without adding too much mass. The effect of the panel size and the stiffness of the grid-like frame effect of the honeycomb sandwich structures on sound transmission are discussed lastly. For the second sound-proof sandwich panel design, each unit cell of the sandwich panel is replaced by a Helmholtz resonator by perforating a small hole on the top face sheet. A perfect sound absorber sandwich panel with coupled Helmholtz resonators is proposed by two types: single identical Helmholtz resonator in each unit cell and dual Helmholtz resonators with different orifices, arranged in each cell arranged periodically. The soundproof sandwich panel is modelled as a panel embedded in rigid panel and assumed as a semiinfinite space with hard boundary condition. The net/mutual impedance model is first proposed and derived by solving Kirchhoff-Helmholtz integral by using the Green's function. The thermal-viscous energy dissipation at the thermal boundary layer dominates the total energy consumed. Two types of perfect sound absorber sandwich panel are designed in the last part. Two theoretical methods: the average energy and the equivalent surface impedance method are used to predict sound absorption performance. The geometry for perfect sound absorber sandwich panel at a target frequency can be obtained when the all the Helmholtz resonators are at resonance and the surface impedance of the sandwich panel matches the air impedance. The bandwidth for the identical sandwich panel mainly depends on the neck radius. The absorptive property of the dual Helmholtz resonators type of sandwich panel is studied by

14 CFR 29.1103 - Induction systems ducts and air duct systems.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Induction systems ducts and air duct systems. 29.1103 Section 29.1103 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Induction System § 29.1103 Induction systems ducts and air duct...

Pacific and Atlantic herring produce burst pulse sounds.

Science.gov (United States)

Wilson, Ben; Batty, Robert S; Dill, Lawrence M

2004-02-07

The commercial importance of Pacific and Atlantic herring (Clupea pallasii and Clupea harengus) has ensured that much of their biology has received attention. However, their sound production remains poorly studied. We describe the sounds made by captive wild-caught herring. Pacific herring produce distinctive bursts of pulses, termed Fast Repetitive Tick (FRT) sounds. These trains of broadband pulses (1.7-22 kHz) lasted between 0.6 s and 7.6 s. Most were produced at night; feeding regime did not affect their frequency, and fish produced FRT sounds without direct access to the air. Digestive gas or gulped air transfer to the swim bladder, therefore, do not appear to be responsible for FRT sound generation. Atlantic herring also produce FRT sounds, and video analysis showed an association with bubble expulsion from the anal duct region (i.e. from the gut or swim bladder). To the best of the authors' knowledge, sound production by such means has not previously been described. The function(s) of these sounds are unknown, but as the per capita rates of sound production by fish at higher densities were greater, social mediation appears likely. These sounds may have consequences for our understanding of herring behaviour and the effects of noise pollution.

Sound beam manipulation based on temperature gradients

Energy Technology Data Exchange (ETDEWEB)

Qian, Feng [Key Laboratory of Modern Acoustics, Institute of Acoustics and School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China); School of Physics & Electronic Engineering, Changshu Institute of Technology, Changshu 215500 (China); Quan, Li; Liu, Xiaozhou, E-mail: xzliu@nju.edu.cn; Gong, Xiufen [Key Laboratory of Modern Acoustics, Institute of Acoustics and School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China)

2015-10-28

Previous research with temperature gradients has shown the feasibility of controlling airborne sound propagation. Here, we present a temperature gradients based airborne sound manipulation schemes: a cylindrical acoustic omnidirectional absorber (AOA). The proposed AOA has high absorption performance which can almost completely absorb the incident wave. Geometric acoustics is used to obtain the refractive index distributions with different radii, which is then utilized to deduce the desired temperature gradients. Since resonant units are not applied in the scheme, its working bandwidth is expected to be broadband. The scheme is temperature-tuned and easy to realize, which is of potential interest to fields such as noise control or acoustic cloaking.

Ultrathin metasurface with high absorptance for waterborne sound

KAUST Repository

Mei, Jun

2018-01-12

We present a design for an acoustic metasurface which can efficiently absorb low-frequency sound energy in water. The metasurface has a simple structure and consists of only two common materials: i.e., water and silicone rubber. The optimized material and geometrical parameters of the designed metasurface are determined by an analytic formula in conjunction with an iterative process based on the retrieval method. Although the metasurface is as thin as 0.15 of the wavelength, it can absorb 99.7% of the normally incident sound wave energy. Furthermore, the metasurface maintains a substantially high absorptance over a relatively broad bandwidth, and also works well for oblique incidence with an incident angle of up to 50°. Potential applications in the field of underwater sound isolation are expected.

ECOLO-HOUSE in the snowy town. Study of the ventilating function what the heat collecting system of the air duct utilizing attic has; Yukiguni ECOLO-HOUSE. Kison kaoku no yaneura wo riyoshita duct shunetsu system

Energy Technology Data Exchange (ETDEWEB)

Umemiya, H; Hirosawa, K [Yamagata University, Yamagata (Japan)

1996-10-27

Described in this paper is an air duct heat collecting system, forming a link in the chain of natural energy utilization, in an attic of a house actually in presence. When a sirocco fan (blowing air from an indoor induction duct into the room) at the base of the highblocked floor is turned, air is sucked through an air intake under the eaves into a heat collecting duct (constructed utilizing the tilt roof and rafter). Heat from the roof warmed by sunshine is absorbed by air in the heat collecting duct and is fed to the highblocked floor structure through a heat collecting room and the induction duct. This system functions quite effectively as a ventilating device. Dew condensation on the walls and floor and musty smell have been eliminated. This system is good enough as a heater even on chilly days in early spring when there is sunshine. In the time zone with the sun shining, the system collects 4{times}10{sup 4}kJ per day, exhibiting a heat collecting efficiency of 4%. The heat collecting duct was analyzed for thermal environment, and the heat flux of the collected heat was determined as Qk(W/m{sup 2}=0.1{times}I-1.3{Theta}d-{Theta}a). In this equation, I is the quantity of insolation (W/m{sup 2}), {Theta}d is the temperature in the heat collecting duct, and {Theta}a is the free air temperature. 2 refs., 8 figs.

Analysis of Dual Rotating Rake Data from the NASA Glenn Advanced Noise Control Fan Duct with Artificial Sources

Science.gov (United States)

Dahl, Milo D.; Sutliff, Daniel L.

2014-01-01

The Rotating Rake mode measurement system was designed to measure acoustic duct modes generated by a fan stage. Initially, the mode amplitudes and phases were quantified from a single rake measurement at one axial location. To directly measure the modes propagating in both directions within a duct, a second rake was mounted to the rotating system with an offset in both the axial and the azimuthal directions. The rotating rake data analysis technique was then extended to include the data measured by the second rake. The analysis resulted in a set of circumferential mode levels at each of the two rake microphone locations. Radial basis functions were then least-squares fit to this data to obtain the radial mode amplitudes for the modes propagating in both directions within the duct. Validation experiments have been conducted using artificial acoustic sources. Results are shown for the measurement of the standing waves in the duct from sound generated by one and two acoustic sources that are separated into the component modes propagating in both directions within the duct. Measured reflection coefficients from the open end of the duct are compared to analytical predictions.

An easier method for performing a pancreaticojejunostomy for the soft pancreas using a fast-absorbable suture

OpenAIRE

Hakamada, Kenichi; Narumi, Shunji; Toyoki, Yoshikazu; Nara, Masaki; Ishido, Kenosuke; Miura, Takuya; Kubo, Norihito; Sasaki, Mutsuo

2008-01-01

AIM: To clarify the usefulness of a new method for performing a pancreaticojejunostomy by using a fast-absorbable suture material irradiated polyglactin 910, and a temporary stent tube for a narrow pancreatic duct with a soft pancreatic texture.

Transcystic duct treatment of common bile duct stones

International Nuclear Information System (INIS)

Amberg, J.R.; Chun, G.

1981-01-01

Successful removal of 2 retained common bile duct stones following cholecystostomy is described. With the use of the steerable catheter and the wire basket, one stone was crushed and the second was extracted in retrograde fashion through the cystic duct and gallbladder. (orig.)

Reduction of sound transmission through fuselage walls by alternate resonance tuning (A.R.T.)

Science.gov (United States)

Bliss, Donald B.; Gottwald, James A.

1989-01-01

The ability of alternate resonance tuning (ART) to block sound transmission through light-weight flexible paneled walls by controlling the dynamics of the wall panels is considered. Analytical results for sound transmission through an idealized panel wall illustrate the effect of varying system parameters and show that one or more harmonics of the incident sound field can be cancelled by the present method. Experimental results demonstrate that very large transmission losses with reasonable bandwidths can be achieved by a simple ART panel barrier in a duct.

Validation of a spectrophotometer-based method for estimating daily sperm production and deferent duct transit.

Science.gov (United States)

Froman, D P; Rhoads, D D

2012-10-01

The objectives of the present work were 3-fold. First, a new method for estimating daily sperm production was validated. This method, in turn, was used to evaluate testis output as well as deferent duct throughput. Next, this analytical approach was evaluated in 2 experiments. The first experiment compared left and right reproductive tracts within roosters. The second experiment compared reproductive tract throughput in roosters from low and high sperm mobility lines. Standard curves were constructed from which unknown concentrations of sperm cells and sperm nuclei could be predicted from observed absorbance. In each case, the independent variable was based upon hemacytometer counts, and absorbance was a linear function of concentration. Reproductive tracts were excised, semen recovered from each duct, and the extragonadal sperm reserve determined by multiplying volume by sperm cell concentration. Testicular sperm nuclei were procured by homogenization of a whole testis, overlaying a 20-mL volume of homogenate upon 15% (wt/vol) Accudenz (Accurate Chemical and Scientific Corporation, Westbury, NY), and then washing nuclei by centrifugation through the Accudenz layer. Daily sperm production was determined by dividing the predicted number of sperm nuclei within the homogenate by 4.5 d (i.e., the time sperm with elongated nuclei spend within the testis). Sperm transit through the deferent duct was estimated by dividing the extragonadal reserve by daily sperm production. Neither the efficiency of sperm production (sperm per gram of testicular parenchyma per day) nor deferent duct transit differed between left and right reproductive tracts (P > 0.05). Whereas efficiency of sperm production did not differ (P > 0.05) between low and high sperm mobility lines, deferent duct transit differed between lines (P < 0.001). On average, this process required 2.2 and 1.0 d for low and high lines, respectively. In summary, we developed and then tested a method for quantifying male

Rare bile duct anomaly: B3 duct draining to gallbladder

Directory of Open Access Journals (Sweden)

Seung Eun Lee

2016-01-01

Full Text Available A 10-year-old girl presented with recurrent right upper abdominal pain and dyspepsia. Magnetic resonance cholangiopancreatography revealed a dilated common channel of intrahepatic bile duct of segment 3 (B3 and segment 4 (B4 drained into the gallbladder directly. The patient underwent laparoscopic cholecystectomy and Roux-en Y hepaticojejunostomy (B3-jejunostomy. Among the anatomical variability of the biliary system, the cholecystohepatic ducts are controversial in existence and incidence. We report a very rare variant of a cholecystohepatic duct in which the B3 duct drained into gallbladder directly and to the best of our knowledge this is the first report.

Particle deposition in ventilation ducts

Energy Technology Data Exchange (ETDEWEB)

Sippola, Mark Raymond [Univ. of California, Berkeley, CA (United States)

2002-09-01

Exposure to airborne particles is detrimental to human health and indoor exposures dominate total exposures for most people. The accidental or intentional release of aerosolized chemical and biological agents within or near a building can lead to exposures of building occupants to hazardous agents and costly building remediation. Particle deposition in heating, ventilation and air-conditioning (HVAC) systems may significantly influence exposures to particles indoors, diminish HVAC performance and lead to secondary pollutant release within buildings. This dissertation advances the understanding of particle behavior in HVAC systems and the fates of indoor particles by means of experiments and modeling. Laboratory experiments were conducted to quantify particle deposition rates in horizontal ventilation ducts using real HVAC materials. Particle deposition experiments were conducted in steel and internally insulated ducts at air speeds typically found in ventilation ducts, 2-9 m/s. Behaviors of monodisperse particles with diameters in the size range 1-16 μm were investigated. Deposition rates were measured in straight ducts with a fully developed turbulent flow profile, straight ducts with a developing turbulent flow profile, in duct bends and at S-connector pieces located at duct junctions. In straight ducts with fully developed turbulence, experiments showed deposition rates to be highest at duct floors, intermediate at duct walls, and lowest at duct ceilings. Deposition rates to a given surface increased with an increase in particle size or air speed. Deposition was much higher in internally insulated ducts than in uninsulated steel ducts. In most cases, deposition in straight ducts with developing turbulence, in duct bends and at S-connectors at duct junctions was higher than in straight ducts with fully developed turbulence. Measured deposition rates were generally higher than predicted by published models. A model incorporating empirical equations based on the

Curved-Duct

Directory of Open Access Journals (Sweden)

Je Hyun Baekt

2000-01-01

Full Text Available A numerical study is conducted on the fully-developed laminar flow of an incompressible viscous fluid in a square duct rotating about a perpendicular axis to the axial direction of the duct. At the straight duct, the rotation produces vortices due to the Coriolis force. Generally two vortex cells are formed and the axial velocity distribution is distorted by the effect of this Coriolis force. When a convective force is weak, two counter-rotating vortices are shown with a quasi-parabolic axial velocity profile for weak rotation rates. As the rotation rate increases, the axial velocity on the vertical centreline of the duct begins to flatten and the location of vorticity center is moved near to wall by the effect of the Coriolis force. When the convective inertia force is strong, a double-vortex secondary flow appears in the transverse planes of the duct for weak rotation rates but as the speed of rotation increases the secondary flow is shown to split into an asymmetric configuration of four counter-rotating vortices. If the rotation rates are increased further, the secondary flow restabilizes to a slightly asymmetric double-vortex configuration. Also, a numerical study is conducted on the laminar flow of an incompressible viscous fluid in a 90°-bend square duct that rotates about axis parallel to the axial direction of the inlet. At a 90°-bend square duct, the feature of flow by the effect of a Coriolis force and a centrifugal force, namely a secondary flow by the centrifugal force in the curved region and the Coriolis force in the downstream region, is shown since the centrifugal force in curved region and the Coriolis force in downstream region are dominant respectively.

Bile Duct Cancer (Cholangiocarcinoma)

Science.gov (United States)

... Home > Types of Cancer > Bile Duct Cancer (Cholangiocarcinoma) Bile Duct Cancer (Cholangiocarcinoma) This is Cancer.Net’s Guide to Bile Duct Cancer (Cholangiocarcinoma). Use the menu below to ...

Making sound vortices by metasurfaces

Energy Technology Data Exchange (ETDEWEB)

Ye, Liping; Qiu, Chunyin, E-mail: cyqiu@whu.edu.cn; Lu, Jiuyang; Tang, Kun; Ke, Manzhu; Peng, Shasha [Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Jia, Han [State Key Laboratory of Acoustics and Key Laboratory of Noise and Vibration Research, Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190 (China); Liu, Zhengyou [Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Institute for Advanced Studies, Wuhan University, Wuhan 430072 (China)

2016-08-15

Based on the Huygens-Fresnel principle, a metasurface structure is designed to generate a sound vortex beam in airborne environment. The metasurface is constructed by a thin planar plate perforated with a circular array of deep subwavelength resonators with desired phase and amplitude responses. The metasurface approach in making sound vortices is validated well by full-wave simulations and experimental measurements. Potential applications of such artificial spiral beams can be anticipated, as exemplified experimentally by the torque effect exerting on an absorbing disk.

Developing flow in S-shaped ducts. 2: Circular cross-section duct

Science.gov (United States)

Taylor, A. M. K. P.; Whitelaw, J. H.; Yianneskis, M.

1984-01-01

Laser-Doppler velocimetry measured the laminar and turbulent streamwise flow in a S-duct. The wall pressure distribution and one component of cross-stream velocity were also obtained for the turbulent flow case. Boundary layers near the duct inlet were about 25 percent of the hydraulic diameter in the laminar flow and varied around the periphery of the pipe between 10 percent and 20 percent in turbulent flow. Pressure-driven secondary flows develop in the first half of the S-duct and are attenuated and reversed in the second half. For both Reynolds numbers there is a region near the outer wall of the second half of the duct where the sign of the radial vorticity results in an enforcement of the secondary flow which was established in the first half of the S-duct. The core flow migrates, for both Reynolds numbers, to the outside wall of the first half and lies towards the inside wall of the second half of the S-duct at the outlet. The thinner inlet boundary layers in the turbulent flow give rise to weaker secondary motion.

A wideband absorber for television studios

Science.gov (United States)

Baird, M. D. M.

The acoustic treatment in BBC television has taken various forms to date, all of which have been relatively expensive, some of which provide inadequate absorption. An investigation has been conducted into the possibilities of producing a new type of wideband absorber which would be more economic, also taking installation time into account, than earlier designs. This Report describes the absorption coefficient measurements made on various combinations of materials, from which a wideband sound absorber has been developed. The absorber works efficiently between 50 Hz and 10 kHz, is simple and easy to construct using readily available materials, and is fire resistant. The design lends itself, if necessary, to on-site fine tuning, and savings in the region of 50 percent can be achieved in terms of cost and space with respect to previous designs.

Decay of reverberant sound in a spherical enclosure

International Nuclear Information System (INIS)

Carroll, M.M.; Chien, C.F.

1977-01-01

The assumption of diffuse reflection (Lambert's Law) leads to integral equations for the wall intensity in a reverberant sound field in the steady state and during decay. The latter equation, in the special case of a spherical enclosure with uniformly absorbent walls and uniform wall intensity, allows exponential decay with a decay time which agrees closely with the Norris--Eyring prediction. The sound-intensity and sound-energy density in the medium, during decay, are also calculated

Moth wing scales slightly increase the absorbance of bat echolocation calls.

Directory of Open Access Journals (Sweden)

Jinyao Zeng

Full Text Available Coevolutionary arms races between predators and prey can lead to a diverse range of foraging and defense strategies, such as countermeasures between nocturnal insects and echolocating bats. Here, we show how the fine structure of wing scales may help moths by slightly increasing sound absorbance at frequencies typically used in bat echolocation. Using four widespread species of moths and butterflies, we found that moth scales are composed of honeycomb-like hollows similar to sound-absorbing material, but these were absent from butterfly scales. Micro-reverberation chamber experiments revealed that moth wings were more absorbent at the frequencies emitted by many echolocating bats (40-60 kHz than butterfly wings. Furthermore, moth wings lost absorbance at these frequencies when scales were removed, which suggests that some moths have evolved stealth tactics to reduce their conspicuousness to echolocating bats. Although the benefits to moths are relatively small in terms of reducing their target strengths, scales may nonetheless confer survival advantages by reducing the detection distances of moths by bats by 5-6%.

Sound absorption study on acoustic panel from kapok fiber and egg tray

Science.gov (United States)

Kaamin, Masiri; Mahir, Nurul Syazwani Mohd; Kadir, Aslila Abd; Hamid, Nor Baizura; Mokhtar, Mardiha; Ngadiman, Norhayati

2017-12-01

Noise also known as a sound, especially one that is loud or unpleasant or that causes disruption. The level of noise can be reduced by using sound absorption panel. Currently, the market produces sound absorption panel, which use synthetic fibers that can cause harmful effects to the health of consumers. An awareness of using natural fibers from natural materials gets attention of some parties to use it as a sound absorbing material. Therefore, this study was conducted to investigate the potential of sound absorption panel using egg trays and kapok fibers. The test involved in this study was impedance tube test which aims to get sound absorption coefficient (SAC). The results showed that there was good sound absorption at low frequency from 0 Hz up to 900 Hz where the maximum absorption coefficient was 0.950 while the maximum absorption at high frequencies was 0.799. Through the noise reduction coefficient (NRC), the material produced NRC of 0.57 indicates that the materials are very absorbing. In addition, the reverberation room test was carried out to get the value of reverberation time (RT) in unit seconds. Overall this panel showed good results at low frequencies between 0 Hz up to 1500 Hz. In that range of frequency, the maximum reverberation time for the panel was 3.784 seconds compared to the maximum reverberation time for an empty room was 5.798 seconds. This study indicated that kapok fiber and egg tray as the material of absorption panel has a potential as environmental and cheap products in absorbing sound at low frequency.

Characterization of a piezoelectric valve for an adaptive pneumatic shock absorber

International Nuclear Information System (INIS)

Mikułowski, Grzegorz; Wiszowaty, Rafał; Holnicki-Szulc, Jan

2013-01-01

This paper describes a pneumatic valve based on a multilayer piezoelectric actuator and Hörbiger plates. The device was designed to operate in an adaptive pneumatic shock absorber. The adaptive pneumatic shock absorber was considered as a piston–cylinder device and the valve was intended to be installed inside the piston. The main objective for the valve application was regulating the gas flow between the cylinder’s chambers in order to maintain the desired value of the reaction force generated by the shock absorber. The paper describes the design constraints and requirements, together with results of analytical modelling of fluid flow verified versus experimentally obtained data. The presented results indicate that the desired performance characteristics of the valve were obtained. The geometrical constraints of the flow ducts were studied and the actuator’s functional features analysed. (paper)

Characterization of a piezoelectric valve for an adaptive pneumatic shock absorber

Science.gov (United States)

Mikułowski, Grzegorz; Wiszowaty, Rafał; Holnicki-Szulc, Jan

2013-12-01

This paper describes a pneumatic valve based on a multilayer piezoelectric actuator and Hörbiger plates. The device was designed to operate in an adaptive pneumatic shock absorber. The adaptive pneumatic shock absorber was considered as a piston-cylinder device and the valve was intended to be installed inside the piston. The main objective for the valve application was regulating the gas flow between the cylinder’s chambers in order to maintain the desired value of the reaction force generated by the shock absorber. The paper describes the design constraints and requirements, together with results of analytical modelling of fluid flow verified versus experimentally obtained data. The presented results indicate that the desired performance characteristics of the valve were obtained. The geometrical constraints of the flow ducts were studied and the actuator’s functional features analysed.

An investigation of sound fields based on the acousto-optic effect

DEFF Research Database (Denmark)

Torras Rosell, Antoni; Barrera Figueroa, Salvador; Jacobsen, Finn

2011-01-01

Various types of transducers are nowadays capable of translating different properties of sound waves into mechanical/electrical quantities, which can afterwards be reinterpreted into acoustical ones. However, in certain applications, for example when using microphone arrays, the presence of bulk...... range, and in two different measurement scenarios where the sound field is well-known: in a rectangular duct and in an anechoic room. Models for predicting the acousto-optic effect in such scenarios are derived and measurements are carried out with a laser Doppler vibrometer. The results show a fairly...

Thin absorbers for large-area soft X-ray microcalorimeters

Energy Technology Data Exchange (ETDEWEB)

Rocks, L. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States)]. E-mail: rocks@wisp.physics.wisc.edu; Anderson, M.B. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Bilgri, N. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Brekosky, R. [NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Gwynne Crowder, S. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Figueroa-Feliciano, E. [NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Kelley, R. [NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Kilbourne, C.A. [NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Lai, T. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Lindeman, M.A. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Man, J. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); McCammon, D. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Nelms, K.L. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Porter, F.S. [NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Sivananthan, S. [University of Illinois at Chicago, Chicago, IL 60607 (United States); Vidugiris, G. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Zhao, J. [University of Illinois at Chicago, Chicago, IL 60607 (United States)

2006-04-15

The X-ray Quantum Calorimeter (XQC) sounding rocket experiment utilizes a microcalorimeter array for observing the diffuse soft X-ray background. Observations of such low surface-brightness targets require a large-area detector. We will be using an array of large absorbers. Good absorbers must rapidly and completely thermalize photons, have small heat capacity for high stopping efficiency and have good lateral thermal transport. For observing the soft X-ray background (energies <1 keV), the volume and heat capacity of absorber material can be kept to a minimum by making the absorbers only as thick as needed for high quantum efficiency at these low energies. These thin, large-area absorbers are not self-supporting and have poor lateral heat transport. Depositing the absorber material on a Si substrate provides support and improves lateral thermal conduction. We present heat capacity results for thin HgTe and thin Bi, each on Si substrates. We also describe the HgTe absorber fabrication.

An easier method for performing a pancreaticojejunostomy for the soft pancreas using a fast-absorbable suture

Institute of Scientific and Technical Information of China (English)

Kenichi Hakamada; Shunji Narumi; Yoshikazu Toyoki; Masaki Nara; Kenosuke Ishido; Takuya Miura; Norihito; Mutsuo Sasaki

2008-01-01

AIM:To clarify the usefulness of a new method for performing a pancreaticojejunostomy by using a fastabsorbable suture material irradiated polyglactin 910,and a temporary stent tube for a narrow pancreatic duct with a soft pancreatic texture.METHODS:Among 63 consecutive patients with soft pancreas undergoing a pancreaticoduodenectomy from 2003 to 2006,35 patients were treated with a new reconstructive method.Briefly,after the pancreatic transaction,a stent tube was inserted into the lumen of the pancreatic duct and ligated with it by a fastabsorbable suture.Another tip of the stent tube was introduced into the intestinal lumen at the jejunal limb,where a purse-string suture was made by another fast-absorbable suture to roughly fix the tube.The pancreaticojejunostomy was completed by ligating two fast-absorbable sutures to approximate the ductal end and the jejunal mucosa,and by adding a rough anastomosis between the pancreatic parenchyma and the seromuscular layer of the jejunum.The initial surgical results with this method were retrospectively compared with those of the 28 patients treated with conventional duct-to-mucosa anastomosis.RESULTS:The incidences of postoperative morbidity including pancreatic fistula were comparable between the two groups (new;3%-17% vs conventional;7%-14% according to the definitions).There was no mortality and re-admission.Late complications were also rarely seen.CONCLUSION:A pancreaticojejunostomy using an irradiated polyglactin 910 suture material and a temporary stent is easy to perform and is feasible even in cases with a narrow pancreatic duct and a normal soft pancreas.

ECOLO-HOUSE in the heavy snow-fall region. Study of the ventilating function that the heat collecting system of the air duct utilizing attic has; Yukiguni ECOLO-HOUSE. Kison kaoku no yaneura wo riyoshita duct shunetsu system kanki kino hyoka

Energy Technology Data Exchange (ETDEWEB)

Umemiya, H; Hirosawa, K [Yamagata University, Yamagata (Japan)

1997-11-25

This paper reports a duct heat collecting system installed in the ECOLO-HOUSE for snow countries. This system is an air heat collecting system of the outside air introducing type utilizing as a solar heat collector the single pitch roof often seen in snow countries. Outside air is introduced from below eaves into a heat collecting duct made by nailing plywoods onto rafters from the attic side to collect heat on the roof. Operating a sirocco fan connected to the induction duct located on the high-floor foundation sucks outside air from an air intake opening under the eaves into the heat collecting duct. Air which has absorbed heat on the roof and been warmed in the heat collecting duct by insolation goes into a heat collecting chamber. The air is sent into the high-floor foundation through the induction duct laid from the heat collecting chamber. Air is exchanged 8.7 times by the fan when it is operated all day continuously. Condensation in the fuel chamber floor and walls during the rainy season has disappeared, and so has odor at the same time. As a result of the humidity measurement, a location into which warm air is sent has difference in humidity as great as 15% from a location where no warm air is sent. 2 refs., 6 figs., 2 tabs.

Dual Rotating Rake Measurements of Higher-Order Duct Modes: Validation Using Experimental and Numerical Data

Science.gov (United States)

Dahl, Milo D.; Hixon, Duane R.; Sutliff, Daniel L.

2018-01-01

A rotating rake mode measurement system was designed to measure acoustic duct modes generated by a fan stage. After analysis of the measured data, the mode coefficient amplitudes and phases were quantified. Early studies using this system found that mode power levels computed from rotating rake measured data would agree with the far-field power levels. However, this agreement required that the sound from the noise sources within the duct propagated outward from the duct exit without reflection and previous studies suggested conditions could exist where significant reflections could occur. This paper shows that mounting a second rake to the rotating system, with an offset in both the axial and the azimuthal directions, measures the data necessary to determine the modes propagating in both directions within a duct. The rotating rake data analysis technique was extended to include the data measured by the second rake. The analysis resulted in a set of circumferential mode coefficients at each of the two rake microphone locations. Radial basis functions were then least-squares fit to this data to obtain the radial mode coefficients for the modes propagating in both directions within the duct while accounting for the presence of evanescent modes. The validation of the dual-rotating-rake measurements was conducted using data from a combination of experiments and numerical calculations to compute reflection coefficients and other mode coefficient ratios. Compared to results from analytical and numerical computations, the results from dual-rotating-rake measured data followed the expected trends when frequency, mode number, and duct termination geometry were changed.

Duct-to-duct biliary reconstruction after radical resection of Bismuth IIIa hilar cholangiocarcinoma.

Science.gov (United States)

Wu, Wen-Guang; Gu, Jun; Dong, Ping; Lu, Jian-Hua; Li, Mao-Lan; Wu, Xiang-Song; Yang, Jia-Hua; Zhang, Lin; Ding, Qi-Chen; Weng, Hao; Ding, Qian; Liu, Ying-Bin

2013-04-21

At present, radical resection remains the only effective treatment for patients with hilar cholangiocarcinoma. The surgical approach for R0 resection of hilar cholangiocarcinoma is complex and diverse, but for the biliary reconstruction after resection, almost all surgeons use Roux-en-Y hepaticojejunostomy. A viable alternative to Roux-en-Y reconstruction after radical resection of hilar cholangiocarcinoma has not yet been proposed. We report a case of performing duct-to-duct biliary reconstruction after radical resection of Bismuth IIIa hilar cholangiocarcinoma. End-to-end anastomosis between the left hepatic duct and the distal common bile duct was used for the biliary reconstruction, and a single-layer continuous suture was performed along the bile duct using 5-0 prolene. The patient was discharged favorably without biliary fistula 2 wk later. Evidence for tumor recurrence was not found after an 18 mo follow-up. Performing bile duct end-to-end anastomosis in hilar cholangiocarcinoma can simplify the complex digestive tract reconstruction process.

Reciprocity principle in duct acoustics

Science.gov (United States)

Cho, Y.-C.

1979-01-01

Various reciprocity relations in duct acoustics have been derived on the basis of the spatial reciprocity principle implied in Green's functions for linear waves. The derivation includes the reciprocity relations between mode conversion coefficients for reflection and transmission in nonuniform ducts, and the relation between the radiation of a mode from an arbitrarily terminated duct and the absorption of an externally incident plane wave by the duct. Such relations are well defined as long as the systems remain linear, regardless of acoustic properties of duct nonuniformities which cause the mode conversions.

Reference values of MRI measurements of the common bile duct and pancreatic duct in children

Energy Technology Data Exchange (ETDEWEB)

Gwal, Kriti; Bedoya, Maria A.; Patel, Neal; Darge, Kassa; Anupindi, Sudha A. [University of Pennsylvania Perelman School of Medicine, Department of Radiology, The Children' s Hospital of Philadelphia, Philadelphia, PA (United States); Rambhatla, Siri J. [Beth Israel Medical Center, Department of Pediatrics, Newark, NJ (United States); Sreedharan, Ram R. [University of Pennsylvania, Departments of Gastroenterology, Hepatology and Nutrition, The Children' s Hospital of Philadelphia, Perelman School of Medicine, Philadelphia, PA (United States)

2015-08-15

Magnetic resonance imaging/cholangiopancreatography (MRI/MRCP) is now an essential imaging modality for the evaluation of biliary and pancreatic pathology in children, but there are no data depicting the normal diameters of the common bile duct (CBD) and pancreatic duct. Recognition of abnormal duct size is important and the increasing use of MRCP necessitates normal MRI measurements. To present normal MRI measurements for the common bile duct and pancreatic duct in children. In this retrospective study we searched all children ages birth to 10 years in our MR urography (MRU) database from 2006 until 2013. We excluded children with a history of hepatobiliary or pancreatic surgery. We stratified 204 children into five age groups and retrospectively measured the CBD and the pancreatic duct on 2-D axial and 3-D coronal T2-weighted sequences. We performed statistical analysis, using logistic and linear regressions to detect the age association of the visibility and size of the duct measurements. We used non-parametric tests to detect gender and imaging plane differences. Our study included 204 children, 106 (52%) boys and 98 (48%) girls, with a median age of 33 months (range 0-119 months). The children were distributed into five age groups. The common bile duct was visible in all children in all age groups. The pancreatic duct was significantly less visible in the youngest children, group 1 (54/67, 80.5%; P = 0.003) than in the oldest children, group 5 (22/22, 100%). In group 2 the pancreatic duct was seen in 19/21 (90.4%), in group 3 52/55 (94.5%), and in group 4 39/39 (100%). All duct measurements increased with age (P < 0.001; r-value > 0.423), and the incremental differences between ages were significant. The measurement variations between the axial and coronal planes were statistically significant (P < 0.001); however these differences were fractions of millimeters. For example, in group 1 the mean coronal measurement of the CBD was 2.1 mm and the axial

Reference values of MRI measurements of the common bile duct and pancreatic duct in children

International Nuclear Information System (INIS)

Gwal, Kriti; Bedoya, Maria A.; Patel, Neal; Darge, Kassa; Anupindi, Sudha A.; Rambhatla, Siri J.; Sreedharan, Ram R.

2015-01-01

Magnetic resonance imaging/cholangiopancreatography (MRI/MRCP) is now an essential imaging modality for the evaluation of biliary and pancreatic pathology in children, but there are no data depicting the normal diameters of the common bile duct (CBD) and pancreatic duct. Recognition of abnormal duct size is important and the increasing use of MRCP necessitates normal MRI measurements. To present normal MRI measurements for the common bile duct and pancreatic duct in children. In this retrospective study we searched all children ages birth to 10 years in our MR urography (MRU) database from 2006 until 2013. We excluded children with a history of hepatobiliary or pancreatic surgery. We stratified 204 children into five age groups and retrospectively measured the CBD and the pancreatic duct on 2-D axial and 3-D coronal T2-weighted sequences. We performed statistical analysis, using logistic and linear regressions to detect the age association of the visibility and size of the duct measurements. We used non-parametric tests to detect gender and imaging plane differences. Our study included 204 children, 106 (52%) boys and 98 (48%) girls, with a median age of 33 months (range 0-119 months). The children were distributed into five age groups. The common bile duct was visible in all children in all age groups. The pancreatic duct was significantly less visible in the youngest children, group 1 (54/67, 80.5%; P = 0.003) than in the oldest children, group 5 (22/22, 100%). In group 2 the pancreatic duct was seen in 19/21 (90.4%), in group 3 52/55 (94.5%), and in group 4 39/39 (100%). All duct measurements increased with age (P < 0.001; r-value > 0.423), and the incremental differences between ages were significant. The measurement variations between the axial and coronal planes were statistically significant (P < 0.001); however these differences were fractions of millimeters. For example, in group 1 the mean coronal measurement of the CBD was 2.1 mm and the axial

A frequency domain linearized Navier-Stokes equations approach to acoustic propagation in flow ducts with sharp edges.

Science.gov (United States)

Kierkegaard, Axel; Boij, Susann; Efraimsson, Gunilla

2010-02-01

Acoustic wave propagation in flow ducts is commonly modeled with time-domain non-linear Navier-Stokes equation methodologies. To reduce computational effort, investigations of a linearized approach in frequency domain are carried out. Calculations of sound wave propagation in a straight duct are presented with an orifice plate and a mean flow present. Results of transmission and reflections at the orifice are presented on a two-port scattering matrix form and are compared to measurements with good agreement. The wave propagation is modeled with a frequency domain linearized Navier-Stokes equation methodology. This methodology is found to be efficient for cases where the acoustic field does not alter the mean flow field, i.e., when whistling does not occur.

Bile duct stricture

Science.gov (United States)

... duct, the tube that moves bile from the liver to the small intestine. Bile is a substance that helps with digestion. ... causes of this condition include: Cancer of the bile duct, liver or pancreas Damage and scarring due to a ...

Blocked Tear Duct

Science.gov (United States)

... of the nose (lacrimal sac). From there tears travel down a duct (the nasolacrimal duct) draining into your nose. Once in the nose, tears are reabsorbed. A blockage can occur at any point in the tear drainage system, from the puncta ...

Ducted fuel injection

Energy Technology Data Exchange (ETDEWEB)

Mueller, Charles J.

2018-03-06

Various technologies presented herein relate to enhancing mixing inside a combustion chamber to form one or more locally premixed mixtures comprising fuel and charge-gas with low peak fuel to charge-gas ratios to enable minimal, or no, generation of soot and other undesired emissions during ignition and subsequent combustion of the locally premixed mixtures. To enable sufficient mixing of the fuel and charge-gas, a jet of fuel can be directed to pass through a bore of a duct causing charge-gas to be drawn into the bore creating turbulence to mix the fuel and the drawn charge-gas. The duct can be located proximate to an opening in a tip of a fuel injector. The duct can comprise of one or more holes along its length to enable charge-gas to be drawn into the bore, and further, the duct can cool the fuel and/or charge-gas prior to combustion.

Thermal neutrons streaming in straight duct

International Nuclear Information System (INIS)

Jehouani, A.; Boulkheir, M.; Ichaoui, R.

2000-01-01

The neutron streaming in duct is due to two phenomena: a) direct propagation and b) reflection on duct wall. We have used the Monte Carlo method to evaluate the ratio of the reflected neutrons flux by the duct wall to the total flux at the exit of the duct for iron and aluminium. Ten neutrons energy groups are considered between 10 -5 eV and 10 eV. A Fortran program is developed to evaluate the neutron double differential albedo. It is shown that the two following approximations are largely justified: i) Three collisions in the duct wall are sufficient to attain the asymptotic limit of the multiscattered neutron double differential albedo ii) The points of entry and exit of the neutron in the duct wall may be considered the same for the multiscattered neutrons. For a punctual source at the mouth of the duct, we have determined the direct and the reflected part of the total thermal neutron flux at the exit of the duct for different lengths and different radius of the duct. For a punctual source, we have found that the major contribution to the total flux of neutrons at the exit is due to the neutron reflection by walls and the reflection contribution decreases when the neutron energy decreases. For a constant length of the duct, the reflected part decreases when the duct radius increases while for the disk shaped source we have found the opposite phenomena. The transmitted neutron flux distribution at the exit of the duct are determined for disk shaped source for different neutron energy and for different distance from the exit center. (author)

Vitellointestinal Duct Anomalies in Infancy

OpenAIRE

Kadian, Yogender Singh; Verma, Anjali; Rattan, Kamal Nain; Kajal, Pardeep

2016-01-01

Background: Vitellointestinal duct (VID) or omphalomesenteric duct anomalies are secondary to the persistence of the embryonic vitelline duct, which normally obliterates by weeks 5–9 of intrauterine life. Methods: This is a retrospective analysis of a total of 16 patients of symptomatic remnants of vitellointestinal duct from period of Jan 2009 to May 2013. Results: Male to female ratio (M:F) was 4.3:1 and mean age of presentation was 2 months and their mode of presentation was: paten...

Patent arterial duct

Directory of Open Access Journals (Sweden)

Martin Robin P

2009-07-01

Full Text Available Abstract Patent arterial duct (PAD is a congenital heart abnormality defined as persistent patency in term infants older than three months. Isolated PAD is found in around 1 in 2000 full term infants. A higher prevalence is found in preterm infants, especially those with low birth weight. The female to male ratio is 2:1. Most patients are asymptomatic when the duct is small. With a moderate-to-large duct, a characteristic continuous heart murmur (loudest in the left upper chest or infraclavicular area is typical. The precordium may be hyperactive and peripheral pulses are bounding with a wide pulse pressure. Tachycardia, exertional dyspnoea, laboured breathing, fatigue or poor growth are common. Large shunts may lead to failure to thrive, recurrent infection of the upper respiratory tract and congestive heart failure. In the majority of cases of PAD there is no identifiable cause. Persistence of the duct is associated with chromosomal aberrations, asphyxia at birth, birth at high altitude and congenital rubella. Occasional cases are associated with specific genetic defects (trisomy 21 and 18, and the Rubinstein-Taybi and CHARGE syndromes. Familial occurrence of PAD is uncommon and the usual mechanism of inheritance is considered to be polygenic with a recurrence risk of 3%. Rare families with isolated PAD have been described in which the mode of inheritance appears to be dominant or recessive. Familial incidence of PAD has also been linked to Char syndrome, familial thoracic aortic aneurysm/dissection associated with patent arterial duct, and familial patent arterial duct and bicuspid aortic valve associated with hand abnormalities. Diagnosis is based on clinical examination and confirmed with transthoracic echocardiography. Assessment of ductal blood flow can be made using colour flow mapping and pulsed wave Doppler. Antenatal diagnosis is not possible, as PAD is a normal structure during antenatal life. Conditions with signs and symptoms of

Reactive control of subsonic axial fan noise in a duct.

Science.gov (United States)

Liu, Y; Choy, Y S; Huang, L; Cheng, L

2014-10-01

Suppressing the ducted fan noise at low frequencies without varying the flow capacity is still a technical challenge. This study examines a conceived device consisting of two tensioned membranes backed with cavities housing the axial fan for suppression of the sound radiation from the axial fan directly. The noise suppression is achieved by destructive interference between the sound fields from the axial fan of a dipole nature and sound radiation from the membrane via vibroacoustics coupling. A two-dimensional model with the flow effect is presented which allows the performance of the device to be explored analytically. The air flow influences the symmetrical behavior and excites the odd in vacuo mode response of the membrane due to kinematic coupling. Such an asymmetrical effect can be compromised with off-center alignment of the axial fan. Tension plays an important role to sustain the performance to revoke the deformation of the membrane during the axial fan operation. With the design of four appropriately tensioned membranes covered by a cylindrical cavity, the first and second blade passage frequencies of the axial fan can be reduced by at least 20 dB. The satisfactory agreement between experiment and theory demonstrates that its feasibility is practical.

Eversion Bile Duct Anastomosis: A Safe Alternative for Bile Duct Size Discrepancy in Deceased Donor Liver Transplantation.

Science.gov (United States)

Leal-Leyte, Pilar; McKenna, Greg J; Ruiz, Richard M; Anthony, Tiffany L; Saracino, Giovanna; Giuliano, Testa; Klintmalm, Goran B; Kim, Peter Tw

2018-04-10

Introduction Bile duct size discrepancy in liver transplantation may increase the risk of biliary complications. The aim of this study was to evaluate the safety and outcomes of the eversion bile duct anastomosis technique in deceased donor liver transplantation (DDLT) with duct to duct anastomosis. Methods A total of 210 patients who received a DDLT with duct to duct anastomosis from 2012 to 2017 were divided into two groups: those who had eversion bile duct anastomosis (N=70) and standard bile duct anastomosis (N=140). Biliary complications rates were compared between the two groups. Results There was no difference in the cumulative incidence of biliary strictures (P=0.20) and leaks (P=0.17) between the two groups. The biliary complication rate in the eversion group was 14.3% and 11.4% in the standard anastomosis group. All the biliary complications in the eversion group were managed with endoscopic stenting. A severe size mismatch (≥3:1 ratio) was associated with a significantly higher incidence of biliary strictures (44.4%) compared to 2:1 ratio (8.2%), (P=0.002). Conclusion The use of the eversion technique is a safe alternative for bile duct discrepancy in deceased donor liver transplantation; however, severe bile duct size mismatch may be a risk factor for biliary strictures with such technique. This article is protected by copyright. All rights reserved. © 2018 by the American Association for the Study of Liver Diseases.

Should you get your heating ducts cleaned?

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

Canada Mortgage and Housing Corporation conducted research into duct cleaning during which time several houses were tested for hot air furnace duct performance before and after cleaning. Duct cleaning is a major industry which claims that cleaning of ducts will provide you with better indoor air quality, reduce household molds and allergens, get rid of house dust, result in more airflow and better delivery of warm air and reduce energy costs. This report does not substantiate those claims. Researchers found little or no discernible differences in the concentrations of house airborne particles or in duct airflows due to duct cleaning. This is because ducts are metal passages that cannot create dust. Most household dusts come from outdoors that has been tracked in or blows through windows and other openings. While duct cleaning may be justifiable personally, it does not change the quality of the air you breathe, nor will it significantly affect airflow or heating costs. Some filters effectively clean the air in the ducts but they do not create a dust-free environment because of the above-mentioned dust sources. The only time that duct cleaning may make sense is if you have water in your ducts that can result in mold growth, if you are moving into a newly constructed house to remove drywall dust, if your are having trouble with furnace airflow, or if you see an accumulation of debris in the return air ducts. It was emphasized that broadcast spraying of biocides within the duct system should not be performed.

An integrated experimental and computational approach to material selection for sound proof thermally insulted enclosure of a power generation system

Science.gov (United States)

Waheed, R.; Tarar, W.; Saeed, H. A.

2016-08-01

Sound proof canopies for diesel power generators are fabricated with a layer of sound absorbing material applied to all the inner walls. The physical properties of the majority of commercially available sound proofing materials reveal that a material with high sound absorption coefficient has very low thermal conductivity. Consequently a good sound absorbing material is also a good heat insulator. In this research it has been found through various experiments that ordinary sound proofing materials tend to rise the inside temperature of sound proof enclosure in certain turbo engines by capturing the heat produced by engine and not allowing it to be transferred to atmosphere. The same phenomenon is studied by creating a finite element model of the sound proof enclosure and performing a steady state and transient thermal analysis. The prospects of using aluminium foam as sound proofing material has been studied and it is found that inside temperature of sound proof enclosure can be cut down to safe working temperature of power generator engine without compromise on sound proofing.

Bile Duct Adenoma with Oncocytic Features

Directory of Open Access Journals (Sweden)

E. J. Johannesen

2014-01-01

Full Text Available Bile duct adenomas are benign bile duct proliferations usually encountered as an incidental finding. Oncocytic bile duct neoplasms are rare and the majority are malignant. A 61-year-old male with a diagnosis of colorectal adenocarcinoma was undergoing surgery when a small white nodule was discovered on the surface of the right lobe of his liver. This lesion was composed of cytologically bland cells arranged in tightly packed glands. These cells were immunopositive for cytokeratin 7, negative for Hep Par 1, contained mucin, and had a Ki67 proliferation index of 8%. The morphology, immunophenotype, presence of mucin, and normal appearing bile ducts, as well as the increased Ki67 proliferation rate, were consistent with a bile duct adenoma with oxyphilic (oncocytic change. Oncocytic tumors in the liver are rare; the first described in 1992. Only two bile duct adenomas with oncocytic change have been reported and neither of them had reported mucin production or the presence of normal appearing bile ducts within the lesion.

Vacuum exhaust duct used for thermonuclear device

International Nuclear Information System (INIS)

Tachikawa, Nobuo; Kondo, Mitsuaki; Honda, Tsutomu.

1990-01-01

The present invention concerns a vacuum exhaust duct used for a thermonuclear device. A cylindrical metal liners is lined with a gap to the inside of a vacuum exhaust duct main body. Bellows are connected to both ends of the metal liners and the end of the bellows is welded to the vacuum exhaust duct main body. Futher, a heater is mounted to the metal liner on the side of the vacuum exhaust duct main body, and the metal liner is heated by the heater to conduct baking for the vacuum exhaust duct main body. Accordingly, since there is no requirement for elevating the temperature of the vacuum exhaust duct upon conducting baking, the vacuum exhaust duct scarcely suffers substantial deformation due to heat expansion. Further, there is also no substantial deformation for the bellows disposed between the outer circumference of the vacuum vessel and a portion of a vacuum exhaust duct, so that the durability of the bellows is greatly improved. (I.S.)

Quadcopter thrust optimization with ducted-propeller

Directory of Open Access Journals (Sweden)

Kuantama Endrowednes

2017-01-01

Full Text Available In relation to quadcopter body frame model, propeller can be categorized into propeller with ducted and without ducted. This study present differences between those two using CFD (Computational Fluid Dynamics method. Both categories utilize two blade-propeller with diameter of 406 (mm. Propeller rotation generates acceleration per time unit on the volume of air. Based on the behavior of generated air velocity, ducted propeller can be modeled into three versions. The generated thrust and performance on each model were calculated to determine the best model. The use of ducted propeller increases the total weight of quadcopter and also total thrust. The influence of this modeling were analyzed in detail with variation of angular velocity propeller from 1000 (rpm to 9000 (rpm. Besides the distance between propeller tip and ducted barrier, the size of ducted is also an important part in thrust optimization and total weight minimization of quadcopter.

Radiation resistant ducted superconductive coil

International Nuclear Information System (INIS)

Schleich, A.

1976-01-01

The radiation-resistant ducted superconductive coil consists of a helically wound electrical conductor constituted by an electrically conductive core of superconductive material provided with a longitudinally extending cooling duct. The core is covered with a layer of inorganic insulating material and the duct is covered by an electrically conductive metallic gas-tight sheath. The metallic sheaths on adjacent turns of the coil are secured together. 2 Claims, 4 Drawing Figures

Modified nasolacrimal duct stenting

International Nuclear Information System (INIS)

Tian Min; Jin Mei; Chen Huanjun; Li Yi

2008-01-01

Objective: Traditional nasolacrimal duct stenting possesses some shortcoming including difficulty of pulling ball head guide wire from the nasal cavity with turbinate hypertrophy and nasal septal deviation. The new method of nose-oral tube track establishment can overcome the forementioned and increase the successful rate. Methods: 5 F catheter and arterial sheath were modified to be nasolacrimal duct stent delivery device respectively. Antegrade dacryocystography was taken firstly to display the obstructed site and followed by the modified protocol of inserting the guide wire through nasolacrimal duct and nasal cavity, and establishing the stent delivery track for retrograde stent placement. Results: 5 epiphora patients with failure implantation by traditional method were all succeeded through the modified stenting (100%). During 6-mouth follow-up, no serious complications and reocclusion occurred. Conclusion: The establishment of eye-nose-mouth-nose of external nasal guide wire track can improve the successful rate of nasolacrimal duct stenting. (authors)

The "flying" bile duct: avulsion of the common bile duct in a plane crash survivor.

LENUS (Irish Health Repository)

Mohan, H

2012-02-01

Blunt trauma is an unusual cause of extrahepatic bile duct injury. This is a case of a 51-year-old gentleman who sustained a significant seatbelt injury in a plane crash. Laparotomy, performed due to persistent abdominal pain, revealed that the common bile duct (CBD) was completely avulsed from the duodenum. Following insertion of drains and transfer to a hepatobiliary centre, the devascularised CBD was excised and replaced with a roux-en-y hepaticojejunostomy. Necrotic tissue was debrided from the pancreatic head. A persistent bile leak developed from the sub-hepatic drain. Repeat laparotomy revealed a bile leak from small ducts on the liver surface. Ligation of the ducts and bioglue sealing of the area were successfully performed. Subsequent to this a pancreatic fistula developed from the main pancreatic duct, which has since resolved. This unusual case illustrates the need for prompt recognition and early repair to optimise outcomes in traumatic CBD injury.

Duct having oscillatory side wall

Science.gov (United States)

Sprouse, Kenneth M.

2018-04-03

A pump system includes a particulate consolidator pump that has a pump outlet. A duct is coupled to the pump outlet. The duct has a wall that is coupled with an oscillator. The oscillator is operable to oscillate the wall at a controlled frequency. The controlled frequency is selected with respect to breaking static bridging of particulate in the duct due, at least in part, to consolidation of the particulate from a downstream check valve.

The correlation between the dilated extent of bile duct and gallbladder and low bile duct obstructive jaundice diseases

International Nuclear Information System (INIS)

Wang Zhongqiu; Lu Guangming; Li Jieshou; Li Weiqin

2005-01-01

Objective: To evaluate the diagnostic value about the dilated extent of bile duct and gallbladder in low biliary obstructive diseases. Methods: CT and ERCP findings of 105 patients with low biliary obstructive disease were retrospectively analyzed. The dilated extent of intrahepatic and extra- hepatic bile duct and gallbladder were classified into seven types: Type I: severe dilatation of intrahepatic and extrahepatic bile duct and gallbladder; Type II: severe dilatation of extrahepatic bile duct and gallbladder and slight dilated intrahapetic bile duct; Type III: severe dilatation of intrahepatic and extrahepatic bile duct without or slight dilatation of gallbladder; Type IV: severe extrahepatic bile duct dilatation without or slight dilatation of intrahepatic bile duct and gallbladder; Type V: severe intrahepatic bile duct dilatation without or with slight dilatation of extrahepatic bile duct and gallbladder; Type VI: severe gallbladder dilatation without or with slight intrahepatic and extra- hepatic bile duct dilatation; Type VII: without or with slight dilatation of intrahepatic and extrahepatic bile duct and gallbladder. The biliary system dilated extent of low biliary obstructive disease on CT and ERCP were compared with results of clinical, operation, and pathology. Results: Thirty-three cases of tumor and 72 cases of non-tumor were proved by clinical and operation in 105 patients with low biliary obstructive disease. In 33 tumor patients, 16 patients were identified as Type I, 10 patients Type II, 4 patients Type III, 1 patient Type IV, 2 patients Type VII. In 72 non-tumor patients, 4 patients were identified as Type I, 4 patients Type II, 9 patients Type III, 33 patients Type IV, 2 patients Type V, 11 patients Type VI, 19 patients Type VII. A large difference between I, II type and III-VII type biliary dilatation existed in tumor and non-tumor group (χ 2 =47.33, P<0.01). Conclusion:Low obstructive biliary diseases are closely correlated with the dilated

Long-term follow-up after choledochojejunostomy for bile duct stones with complex clearance of the bile duct

NARCIS (Netherlands)

Gouma, D. J.; Konsten, J.; Soeters, P. B.; Von Meyenfeldt, M.; Obertop, H.

1989-01-01

In this retrospective study, the long-term follow-up of patients undergoing choledochojejunostomy (Roux-en-Y) for bile duct stones with complex clearance of the bile duct is evaluated. Bile duct exploration and subsequent choledochojejunostomy (Roux-en-Y) was performed in 43 patients (median age 67

A Plug-and-Play Duct System Evaluation

Energy Technology Data Exchange (ETDEWEB)

Beach, R. [IBACOS, Inc., Pittsburgh, PA (United States); Dickson, B. [IBACOS, Inc., Pittsburgh, PA (United States); Grisolia, A. [IBACOS, Inc., Pittsburgh, PA (United States); Poerschke, A. [IBACOS, Inc., Pittsburgh, PA (United States); Rapport, A. [IBACOS, Inc., Pittsburgh, PA (United States)

2017-07-01

This report describes an air distribution system composed of a series of uniformly-sized ducts that terminate in rooms throughout the home and return to a central manifold, similar in fashion to a “home-run” cross-linked polyethylene plumbing system. With a well-designed manifold, each duct receives an equal static pressure potential for airflow from the air handling unit, and the number of needed ducts for each room are simply attached to fittings located on the manifold; in this sense, the system is plug-and-play (PnP). As indicated, all ducts in the PnP system are identical in size and small enough to fit in the ceiling and wall cavities of a house (i.e., less than 3.5-in. outer diameter). These ducts are also more appropriately sized for the lower airflow requirements of modern, energy-efficient homes; therefore, the velocity of the air moving through the duct is between that of conventional duct systems (approximately 700 ft/min) and high-velocity systems (more than 1,500 ft/min) on the market today. The PnP duct system uses semi-rigid plastic pipes, which have a smooth inner wall and are straightforward to install correctly, resulting in a system that has minimal air leakage. However, plastic ducts are currently not accepted by code for use in residential buildings; therefore, the project team considered other duct materials for the system that are currently accepted by code, such as small-diameter, wirehelix, flexible ductwork.

A Plug-and-Play Duct System Evaluation

Energy Technology Data Exchange (ETDEWEB)

Beach, Robert [IBACOS, Inc., Pittsburgh, PA (United States); Dickson, Bruce [IBACOS, Inc., Pittsburgh, PA (United States); Grisolia, Anthony [IBACOS, Inc., Pittsburgh, PA (United States); Poerschke, Andrew [IBACOS, Inc., Pittsburgh, PA (United States); Rapport, Ari [IBACOS, Inc., Pittsburgh, PA (United States)

2017-07-10

This report describes an air distribution system composed of a series of uniformly-sized ducts that terminate in rooms throughout the home and return to a central manifold, similar in fashion to a “home-run” cross-linked polyethylene plumbing system. With a well-designed manifold, each duct receives an equal static pressure potential for airflow from the air handling unit, and the number of needed ducts for each room are simply attached to fittings located on the manifold; in this sense, the system is plug-and-play (PnP). As indicated, all ducts in the PnP system are identical in size and small enough to fit in the ceiling and wall cavities of a house (i.e., less than 3.5-in. outer diameter). These ducts are also more appropriately sized for the lower airflow requirements of modern, energy-efficient homes; therefore, the velocity of the air moving through the duct is between that of conventional duct systems (approximately 700 ft/min) and high-velocity systems (more than 1,500 ft/min) on the market today. The PnP duct system uses semi-rigid plastic pipes, which have a smooth inner wall and are straightforward to install correctly, resulting in a system that has minimal air leakage. However, plastic ducts are currently not accepted by code for use in residential buildings; therefore, the project team considered other duct materials for the system that are currently accepted by code, such as small-diameter, wirehelix, flexible ductwork.

Acoustic contributions of a sound absorbing blanket placed in a double panel structure: absorption versus transmission.

Science.gov (United States)

Doutres, Olivier; Atalla, Noureddine

2010-08-01

The objective of this paper is to propose a simple tool to estimate the absorption vs. transmission loss contributions of a multilayered blanket unbounded in a double panel structure and thus guide its optimization. The normal incidence airborne sound transmission loss of the double panel structure, without structure-borne connections, is written in terms of three main contributions; (i) sound transmission loss of the panels, (ii) sound transmission loss of the blanket and (iii) sound absorption due to multiple reflections inside the cavity. The method is applied to four different blankets frequently used in automotive and aeronautic applications: a non-symmetric multilayer made of a screen in sandwich between two porous layers and three symmetric porous layers having different pore geometries. It is shown that the absorption behavior of the blanket controls the acoustic behavior of the treatment at low and medium frequencies and its transmission loss at high frequencies. Acoustic treatment having poor sound absorption behavior can affect the performance of the double panel structure.

SNM holdup assessment of Los Alamos exhaust ducts

International Nuclear Information System (INIS)

Marshall, R.S.

1994-02-01

Fissile material holdup in glovebox and fume hood exhaust ducting has been quantified for all Los Alamos duct systems. Gamma-based, nondestructive measurements were used to quantify holdup. The measurements were performed during three measurement campaigns. The first campaign, Phase I, provided foot-by-foot, semiquantitative measurement data on all ducting. These data were used to identify ducting that required more accurate (quantitative) measurement. Of the 280 duct systems receiving Phase I measurements, 262 indicated less than 50 g of fissile holdup and 19 indicated fissile holdup of 50 or more grams. Seven duct systems were measured in a second campaign, called Series 1, Phase II. Holdup estimates on these ducts ranged from 421 g of 235 U in a duct servicing a shut-down uranium-machining facility to 39 g of 239 Pu in a duct servicing an active plutonium-processing facility. Measurements performed in the second campaign proved excessively laborious, so a third campaign was initiated that used more efficient instrumentation at some sacrifice in measurement quality. Holdup estimates for the 12 duct systems measured during this third campaign ranged from 70 g of 235 U in a duct servicing analytical laboratories to 1 g of 235 U and 1 g of 239 Pu in a duct carrying exhaust air to a remote filter building. These quantitative holdup estimates support the conclusion made at the completion of the Phase I measurements that only ducts servicing shut-down uranium operations contain about 400 g of fissile holdup. No ventilation ducts at Los Alamos contain sufficient fissile material holdup to present a criticality safety concern

Nasopalatine duct cyst: A case report

Directory of Open Access Journals (Sweden)

Saikrishna Pasupuleti

2015-01-01

Full Text Available Nasopalatine duct cyst (NPDC is the most common non-odontogenic cyst of oral cavity. Clinically, Nasopalatine duct cyst manifests as an asymptomatic swelling of the palate or the upper lip. Radiographically, it is seen as a heart-shaped radiolucency and can be confused with periapical pathology. The aim of this article is to report a case of a nasopalatine duct cyst in a 36-year-old patient which was misinterpreted for a periapical cyst. Diagnosis of a Nasopalatine duct cyst can be given through clinical, radiographical, and histopathological examination.

Radiologic imaging of bile duct changes by clonorchiasis

International Nuclear Information System (INIS)

Kim, Myung Joon; Yoo, Hyung Sik; Lee, Jong Tae; Jung, Soon Hee

1988-01-01

The changes of the bile ducts were reviewed retrospectively in 38 patients of clonorchiasis by ultrasonography and/or CT. Diagnosis was made in 13 patients by cholecystectomy and exploration of the common bile duct, another 2 patients by segmentectomy and wedge resection of the liver, and 23 patients by stool examination. 14 of 36 cases done ultrasonography showed the parallel channel sign, and small nodular echoes around the dilated bile ducts. And 3 cases showed the echoes of worm of clonorchis sinensis in the common bile duct. 22 of 36 cases showed the parallel channel signs only. All cases (11) done CT showed diffuse dilatation of the peripheral bile ducts. 5 of 11 cases showed ring or tubular contrast enhancement around the dilated bile ducts. In 2 cases of liver resection, the bile ducts showed adenomatous hyperplasia and severe periductal fibrosis. Proliferation of blood vessels and infiltration of inflammatory cells were also seen. So we consider that the increased echoes of the bile duct wall, small nodular echoes around the bile ducts were attributed to the bile duct dilatation, severe adenomatous hyperplasia and periductal fibrosis. The ring or tubular contrast enhancement of the dilated bile ducts seems to be caused by the marked periductal inflammation resulting in capillary proliferation and the periductal fibrosis.

Radiologic imaging of bile duct changes by clonorchiasis

Energy Technology Data Exchange (ETDEWEB)

Kim, Myung Joon; Yoo, Hyung Sik; Lee, Jong Tae; Jung, Soon Hee [Yonsei University College of Medicine, Seoul (Korea, Republic of)

1988-10-15

The changes of the bile ducts were reviewed retrospectively in 38 patients of clonorchiasis by ultrasonography and/or CT. Diagnosis was made in 13 patients by cholecystectomy and exploration of the common bile duct, another 2 patients by segmentectomy and wedge resection of the liver, and 23 patients by stool examination. 14 of 36 cases done ultrasonography showed the parallel channel sign, and small nodular echoes around the dilated bile ducts. And 3 cases showed the echoes of worm of clonorchis sinensis in the common bile duct. 22 of 36 cases showed the parallel channel signs only. All cases (11) done CT showed diffuse dilatation of the peripheral bile ducts. 5 of 11 cases showed ring or tubular contrast enhancement around the dilated bile ducts. In 2 cases of liver resection, the bile ducts showed adenomatous hyperplasia and severe periductal fibrosis. Proliferation of blood vessels and infiltration of inflammatory cells were also seen. So we consider that the increased echoes of the bile duct wall, small nodular echoes around the bile ducts were attributed to the bile duct dilatation, severe adenomatous hyperplasia and periductal fibrosis. The ring or tubular contrast enhancement of the dilated bile ducts seems to be caused by the marked periductal inflammation resulting in capillary proliferation and the periductal fibrosis.

Acoustic contributions of a sound absorbing blanket placed in a double panel structure: Absorption Versus Transmission

OpenAIRE

Doutres , Olivier; Atalla , Noureddine

2010-01-01

International audience; The objective of this paper is to propose a simple tool to estimate the absorption vs. transmission loss contributions of a multilayered blanket unbounded in a double panel structure and thus guide its optimization. The normal incidence airborne sound transmission loss of the double panel structure, without structure-borne connections, is written in terms of three main contributions; (i) sound transmission loss of the panels, (ii) sound transmission loss of the blanket...

Acoustic damping of air ducts. Fundamentals, hall room and real room measurements; Telefoniedaempfung von Luftdurchlaessen Grundlagen, Hallraum- und Realraum-Messungen

Energy Technology Data Exchange (ETDEWEB)

Wolters, T. [TROX GmbH, Neukirchen-Vluyn (Germany). Forschung und Entwicklung

2006-07-01

The methods and concepts of airborne noise measurement and damping are presented. Data for different types of air ducts according to DIN EN ISO7235 are presented in diagrams. Air ducts of similar geometries have similar damping characteristics. The standard measurements are compared with the producers' data, showing that there is no correlation between the measurements and the producers' data. The conclusion is drawn that measuring procedures must be standardized. Structure-borne noise transmission in pipelines is investigated in two real conference rooms. The effectiveness of sound damping measures was illustrated. In cooperation with the Fraunhofer Institute of Constructional Physics (IBPL), calculation methods using existing component characteristics were investigated. Some examples show rather good agreement between calculations and measurements. (orig.)

Effect of duct geometry on Wells turbine performance

International Nuclear Information System (INIS)

Shaaban, S.; Abdel Hafiz, A.

2012-01-01

Highlights: ► A Wells turbine duct design in the form of venturi duct is proposed and investigated. ► Optimum duct geometry is identified. ► Up to 14% increase of the turbine power can be achieved using the optimized duct geometry. ► Up to 9% improve of the turbine efficiency is attained by optimizing the turbine duct geometry. ► The optimized duct geometry results in tangible delay of the turbine stalling point. - Abstract: Wells turbines can represent important source of renewable energy for many countries. An essential disadvantage of Wells turbines is their low aerodynamic efficiency and consequently low power produced. In order to enhance the Wells turbine performance, the present research work proposes the use of a symmetrical duct in the form of a venturi tube with turbine rotor located at throat. The effects of duct area ratio and duct angle are investigated in order to optimize Wells turbine performance. The turbine performance is numerically investigated by solving the steady 3D incompressible Reynolds Averaged Navier–Stocks equation (RANS). A substantial improve of the turbine performance is achieved by optimizing the duct geometry. Increasing both the duct area ratio and duct angle increase the acceleration and deceleration upstream and downstream the rotor respectively. The accelerating flow with thinner boundary layer thickness upstream the rotor reduces the flow separation on the rotor suction side. The downstream diffuser reduces the interaction between tip leakage flow and blade suction side. Up to 14% increase in turbine power and 9% increase in turbine efficiency are achieved by optimizing the duct geometry. On other hand, a tangible delay of the turbine stall point is also detected.

3D Acoustic Modelling of Dissipative Silencers with Nonhomogeneous Properties and Mean Flow

Directory of Open Access Journals (Sweden)

E. M. Sánchez-Orgaz

2014-07-01

Full Text Available A finite element approach is proposed for the acoustic analysis of automotive silencers including a perforated duct with uniform axial mean flow and an outer chamber with heterogeneous absorbent material. This material can be characterized by means of its equivalent acoustic properties, considered coordinate-dependent via the introduction of a heterogeneous bulk density, and the corresponding material airflow resistivity variations. An approach has been implemented to solve the pressure wave equation for a nonmoving heterogeneous medium, associated with the problem of sound propagation in the outer chamber. On the other hand, the governing equation in the central duct has been solved in terms of the acoustic velocity potential considering the presence of a moving medium. The coupling between both regions and the corresponding acoustic fields has been carried out by means of a perforated duct and its acoustic impedance, adapted here to include absorbent material heterogeneities and mean flow effects simultaneously. It has been found that bulk density heterogeneities have a considerable influence on the silencer transmission loss.

Sound field control for a low-frequency test facility

DEFF Research Database (Denmark)

Pedersen, Christian Sejer; Møller, Henrik

2013-01-01

The two largest problems in controlling the reproduction of low-frequency sound for psychoacoustic experiments is the effect of the room due to standing waves and the relatively large sound pressure levels needed. Anechoic rooms are limited downward in frequency and distortion may be a problem even...... at moderate levels, while pressure-field playback can give higher sound pressures but is limited upwards in frequency. A new solution that addresses both problems has been implemented in the laboratory of Acoustics, Aalborg University. The solution uses one wall with 20 loudspeakers to generate a plane wave...... that is actively absorbed when it reaches the 20 loudspeakers on the opposing wall. This gives a homogeneous sound field in the majority of the room with a flat frequency response in the frequency range 2-300 Hz. The lowest frequencies are limited to sound pressure levels in the order of 95 dB. If larger levels...

ITER L 6 equatorial maintenance duct remote handling study

International Nuclear Information System (INIS)

Millard, J.

1996-09-01

The status and conclusions of a preliminary study of equatorial maintenance duct remote handling is reported. Due to issues with the original duct design a significant portion of the study had to be refocused on equatorial duct layout studies. The study gives an overview of some of the options for design of these ducts and the impact of the design on the equipment to work in the duct. To develop a remote handling concept for creating access through the ducts the following design tasks should be performed: define the operations sequences for equatorial maintenance duct opening and closing; review the remote handling requirements for equatorial maintenance duct opening and closing; design concept for door and pipe handling equipment and to propose preliminary procedures for material handling outsides the duct. 35 figs

Spectral measurements of gamma radiation streaming through ducts

International Nuclear Information System (INIS)

Meenakshisundaram, P.K.; Bhatnagar, V.M.; Raghunath, V.M.; Gopinath, D.V.

1979-01-01

The paper presents the spectral measurements of gamma radiation streaming through multi-legged rectangular concrete ducts for cesium-137 and cobald-60 sources. Effect of lead lining the inner surface of the duct on the streaming radiation spectrum and optimization of liner thickness for minimum streaming radiation dose have been studied. For three-legged ducts, a comparative analysis of lead lining the entire duct as against lining any one or both the corners of the duct is reported. It is seen that lead lining any one of the corners would reduce the streaming radiation dose by a factor of 5 to 12. Lining both the corners which is nearly as effective as lining the entire duct reduces the dose by a factor of 16 to 60 depending on the soruce energy and duct dimensions. (orig.)

Measure Guideline: Summary of Interior Ducts in New Construction, Including an Efficient, Affordable Method to Install Fur-Down Interior Ducts

Energy Technology Data Exchange (ETDEWEB)

Beal, D.; McIlvaine , J.; Fonorow, K.; Martin, E.

2011-11-01

This document illustrates guidelines for the efficient installation of interior duct systems in new housing, including the fur-up chase method, the fur-down chase method, and interior ducts positioned in sealed attics or sealed crawl spaces. This document illustrates guidelines for the efficient installation of interior duct systems in new housing. Interior ducts result from bringing the duct work inside a home's thermal and air barrier. Architects, designers, builders, and new home buyers should thoroughly investigate any opportunity for energy savings that is as easy to implement during construction, such as the opportunity to construct interior duct work. In addition to enhanced energy efficiency, interior ductwork results in other important advantages, such as improved indoor air quality, increased system durability and increased homeowner comfort. While the advantages of well-designed and constructed interior duct systems are recognized, the implementation of this approach has not gained a significant market acceptance. This guideline describes a variety of methods to create interior ducts including the fur-up chase method, the fur-down chase method, and interior ducts positioned in sealed attics or sealed crawl spaces. As communication of the intent of an interior duct system, and collaboration on its construction are paramount to success, this guideline details the critical design, planning, construction, inspection, and verification steps that must be taken. Involved in this process are individuals from the design team; sales/marketing team; and mechanical, insulation, plumbing, electrical, framing, drywall and solar contractors.

Financial Aspects of Bile Duct Injuries.

Science.gov (United States)

Palaz Alı, Ozgkıour; Ibis, Abdil Cem; Gurtekin, Basak

2017-11-04

BACKGROUND Major bile duct injury is the most worrisome complication of cholecystectomy. There is no detailed data about the incidence or treatment-related costs of bile duct injuries in Turkey. We aimed to determine prevalence and therapeutic costs of patients with major biliary duct injuries managed in our department, and further estimate a projection of these parameters at the national level. MATERIAL AND METHODS All patients admitted due to bile duct injury during cholecystectomy from 2011 to 2014 were included. Healthcare costs were calculated by summing of their all treatment-related costs in Istanbul Medical Faculty. We collected 2014-2015 data on number of patients diagnosed with cholecystitis in Turkey, the number of cholecystectomies, and the number of the interventions performed following these initial surgeries, which were obtained from the Turkish Social Security Institution. RESULTS Forty-nine patients were enrolled and bilioenteric diversion was performed in 39 patients: 20.4% of patients had Bismuth II, 38.8% had Bismuth III, and 40.8% had Bismuth IV biliary stricture. Comparison of stricture types with total costs, days of hospitalization, and outpatient clinic costs revealed significant differences. Mean total cost of corrective surgeries was 9199 TRY. We estimated that 1.5% to 2.4% of patients who underwent cholecystectomy in Turkey have bile duct injury (including 0.3% with major bile duct injury). CONCLUSIONS New preventive strategies should be used to avoid bile duct injuries, which have a huge financial impact on the national economy.

Vitellointestinal Duct Anomalies in Infancy.

Science.gov (United States)

Kadian, Yogender Singh; Verma, Anjali; Rattan, Kamal Nain; Kajal, Pardeep

2016-01-01

Vitellointestinal duct (VID) or omphalomesenteric duct anomalies are secondary to the persistence of the embryonic vitelline duct, which normally obliterates by weeks 5-9 of intrauterine life. This is a retrospective analysis of a total of 16 patients of symptomatic remnants of vitellointestinal duct from period of Jan 2009 to May 2013. Male to female ratio (M:F) was 4.3:1 and mean age of presentation was 2 months and their mode of presentation was: patent VID in 9 (56.25%) patients, umbilical cyst in 2(12.25%), umbilical granuloma in 2 (12.25%), and Meckel diverticulum as content of hernia sac in obstructed umbilical hernia in 1 (6.25%) patient. Two patients with umbilical fistula had severe electrolyte disturbance and died without surgical intervention. Persistent VID may have varied presentations in infancy. High output umbilical fistula and excessive bowel prolapse demand urgent surgical intervention to avoid morbidity and mortality.

Cholangiographic evaluation of bile duct carcinoma

International Nuclear Information System (INIS)

Nichols, D.A.; MacCarty, R.L.; Gaffey, T.A.

1983-01-01

Cholangiograms and clinical histories of 82 patients with biopsy-proved bile duct carcinoma were reviewed. The carcinomas were classified according to morphologic findings and clinical outcome. Ulcerative colitis and antecedent inflammatory disease of the biliary tree, particularly primary sclerosing cholangitis, seem to predispose to the development of bile duct carcinoma. Focal stenotic lesions were the most common morphologic type (62/82). Polypoid carcinomas and diffuse sclerosing carcinomas were less common and of about equal frequency. Prognosis was best for patients with polypoid carcinomas and worst for those with diffuse sclerosing carcinomas. In 69 cases (84%), the tumors involved the intrahepatic or proximal extrahepatic ducts, makin curative resection difficult or impossible. Patients with carcinomas limited to the more distal extrahepatic bile ducts had a longer average survival and a higher probability of surgical cure. Proper management of patients with bile duct carcinoma requires a complete and accurate cholangiographic evaluation of the morphology, location, and extent of the disease

Different Structures of PVA Nanofibrous Membrane for Sound Absorption Application

Directory of Open Access Journals (Sweden)

Jana Mohrova

2012-01-01

Full Text Available The thin nanofibrous layer has different properties in the field of sound absorption in comparison with porous fibrous material which works on a principle of friction of air particles in contact with walls of pores. In case of the thin nanofibrous layer, which represents a sound absorber here, the energy of sonic waves is absorbed by the principle of membrane resonance. The structure of the membrane can play an important role in the process of converting the sonic energy to a different energy type. The vibration system acts differently depending on the presence of smooth fibers in the structure, amount of partly merged fibers, or structure of polymer foil as extreme. Polyvinyl alcohol (PVA was used as a polymer because of its good water solubility. It is possible to influence the structure of nanofibrous layer during the production process thanks to this property of polyvinyl alcohol.

Fractal Model for Acoustic Absorbing of Porous Fibrous Metal Materials

Directory of Open Access Journals (Sweden)

Weihua Chen

2016-01-01

Full Text Available To investigate the changing rules between sound absorbing performance and geometrical parameters of porous fibrous metal materials (PFMMs, this paper presents a fractal acoustic model by incorporating the static flow resistivity based on Biot-Allard model. Static flow resistivity is essential for an accurate assessment of the acoustic performance of the PFMM. However, it is quite difficult to evaluate the static flow resistivity from the microstructure of the PFMM because of a large number of disordered pores. In order to overcome this difficulty, we firstly established a static flow resistivity formula for the PFMM based on fractal theory. Secondly, a fractal acoustic model was derived on the basis of the static flow resistivity formula. The sound absorption coefficients calculated by the presented acoustic model were validated by the values of Biot-Allard model and experimental data. Finally, the variation of the surface acoustic impedance, the complex wave number, and the sound absorption coefficient with the fractal dimensions were discussed. The research results can reveal the relationship between sound absorption and geometrical parameters and provide a basis for improving the sound absorption capability of the PFMMs.

New concept of the buildup factor in bent ducts

International Nuclear Information System (INIS)

Faik Ouahab, Z.; Jehouani, A.; Groetz, J.-E.

2011-01-01

A major problem confronting the radiation shielding designer is the accurate determination of neutron streaming through various penetrations in walls, ducts and mazes. The previous studies on neutron transmission were performed through empty ducts. The aim of this work is to evaluate the neutron transmission probability through a filled bent duct and the proposition of a new concept of the buildup factor for neutrons in multilegged ducts. An angular biaising technique is used in the Monte Carlo simulations to accelerate the calculation convergence. Results are first compared with those obtained by the MCNPX code. For an empty bent duct, the neutron transmission is only due to the neutron reflection on the duct wall. For a filled duct, the major contribution is due to the scattering on the atoms filling the duct.

Active control of aircraft engine inlet noise using compact sound sources and distributed error sensors

Science.gov (United States)

Burdisso, Ricardo (Inventor); Fuller, Chris R. (Inventor); O'Brien, Walter F. (Inventor); Thomas, Russell H. (Inventor); Dungan, Mary E. (Inventor)

1996-01-01

An active noise control system using a compact sound source is effective to reduce aircraft engine duct noise. The fan noise from a turbofan engine is controlled using an adaptive filtered-x LMS algorithm. Single multi channel control systems are used to control the fan blade passage frequency (BPF) tone and the BPF tone and the first harmonic of the BPF tone for a plane wave excitation. A multi channel control system is used to control any spinning mode. The multi channel control system to control both fan tones and a high pressure compressor BPF tone simultaneously. In order to make active control of turbofan inlet noise a viable technology, a compact sound source is employed to generate the control field. This control field sound source consists of an array of identical thin, cylindrically curved panels with an inner radius of curvature corresponding to that of the engine inlet. These panels are flush mounted inside the inlet duct and sealed on all edges to prevent leakage around the panel and to minimize the aerodynamic losses created by the addition of the panels. Each panel is driven by one or more piezoelectric force transducers mounted on the surface of the panel. The response of the panel to excitation is maximized when it is driven at its resonance; therefore, the panel is designed such that its fundamental frequency is near the tone to be canceled, typically 2000-4000 Hz.

Molecular Mechanisms of Bile Duct Development

OpenAIRE

Zong, Yiwei; Stanger, Ben Z.

2010-01-01

The mammalian biliary system, consisting of the intrahepatic and extrahepatic bile ducts, is responsible for transporting bile from the liver to the intestine. Bile duct dysfunction, as is seen in some congenital biliary diseases such as Alagille syndrome and biliary atresia, can lead to the accumulation of bile in the liver, preventing the excretion of detoxification products and ultimately leading to liver damage. Bile duct formation requires coordinated cell-cell interactions, resulting in...

Compact Buried Ducts in a Hot-Humid Climate House

Energy Technology Data Exchange (ETDEWEB)

Mallay, Dave [Home Innovation Research Labs, Upper Marlboro, MD (United States)

2016-01-07

"9A system of compact, buried ducts provides a high-performance and cost-effective solution for delivering conditioned air throughout the building. This report outlines research activities that are expected to facilitate adoption of compact buried duct systems by builders. The results of this research would be scalable to many new house designs in most climates and markets, leading to wider industry acceptance and building code and energy program approval. The primary research question with buried ducts is potential condensation at the outer jacket of the duct insulation in humid climates during the cooling season. Current best practices for buried ducts rely on encapsulating the insulated ducts with closed-cell spray polyurethane foam insulation to control condensation and improve air sealing. The encapsulated buried duct concept has been analyzed and shown to be effective in hot-humid climates. The purpose of this project is to develop an alternative buried duct system that performs effectively as ducts in conditioned space - durable, energy efficient, and cost-effective - in a hot-humid climate (IECC warm-humid climate zone 3A) with three goals that distinguish this project: 1) Evaluation of design criteria for buried ducts that use common materials and do not rely on encapsulation using spray foam or disrupt traditional work sequences; 2) Establishing design criteria for compact ducts and incorporate those with the buried duct criteria to further reduce energy losses and control installed costs; 3) Developing HVAC design guidance for performing accurate heating and cooling load calculations for compact buried ducts.

Unilateral Duplication Of Parotid Duct. A Rare Anatomical Variation

Directory of Open Access Journals (Sweden)

Humberto Ferreira Arquez

2017-11-01

Full Text Available Background: The paired parotid glands are the largest of the major salivary glands and produces mainly serous secretions. The secretion of this gland reaches the oral cavity through single parotid duct (Stensen’s duct. The parotid duct begins at the anterior border of the gland, crosses the masseter muscle, and then pierces the buccinator muscle to reach the mucosa lining the mouth at the level of the cheek. The purpose of this study is determine the morphologic features of the parotid duct and describe an anatomical variation until now unreported. Methods and Findings: A total of 17 cadavers were used for this study in the Morphology Laboratory at the University of Pamplona. In a cadaver were findings: The main parotid duct originated two conducts: Left superior parotid duct and Left inferior parotid duct, is observed the criss-cross of the ducts, and then perforated the buccinator muscle and entered the oral cavity at a double parotid papilla containing a double opening, separated from each other in 0,98 mm. In the remaining  33 parotid regions (97.06% the parotid duct is conformed to the classical descriptions given in anatomical textbooks. Conclusions: The parotid duct anatomy is important for duct endoscopy, lithotripsy, sialography and trans-ductal facial nerve stimulation in the early stage of facial palsy in some cases. The anatomical variations also has clinical importance for parotid gland surgery and facial cosmetic surgery. To keep in mind the parotid duct variation will reduce iatrogenic injury risks and improve diagnosis of parotid duct injury.

Thoracic duct lymphography by subcutaneous contrast agent ...

African Journals Online (AJOL)

A second lymphography revealed a collateral thoracic duct that was not detected during the first lymphography. The collateral duct was ligated and chylothorax was resolved after the second surgery. The lymphography applied in this study was minimally-invasive and easily provided images of the thoracic duct in a dog with ...

Cystic Duct Closure by Sealing With Bipolar Electrocoagulation

Science.gov (United States)

Damgaard, B.; Jorgensen, L. N.; Larsen, S. S.; Kristiansen, V. B.

2010-01-01

Background: Cystic duct leakage after cholecystectomy is not uncommon and is a potentially serious complication. The aim of this study was to assess a bipolar sealing system (LigaSure®) for closure of the cystic duct. Methods: The records from consecutive laparoscopic cholecystectomies performed in 2 hospitals with closure of the cystic duct with LigaSure after informed consent were recorded and complications and morbidity registered. The records were compared with those of patients undergoing laparoscopic cholecystectomy with closure of the cystic duct with clips during the same period. Results: During the study period, 218 laparoscopic cholecystectomies were performed; 102 of these were performed with the LigaSure. One patient was excluded due to violation of the protocol. We experienced no cases of cystic duct leakage, but in one patient, bile leakage from the gallbladder bed was observed probably due to a small aberrant duct. Conclusion: The LigaSure system was safe and effective for closure and division of the cystic duct in laparoscopic cholecystectomy. PMID:20412641

Self-retaining small-looped catheter for narrow bile ducts in high common bile duct obstruction

International Nuclear Information System (INIS)

Guenther, R.W.; Daehnert, W.

1985-01-01

A new self-retaining catheter was devised for percutaneous drainage of small bile ducts. The device allows safe external drainage without the risk of catheter dislocation even in high bile duct obstruction. The catheter is also suitable for percutaneous nephrostomy in non-dilated pyelocaliceal system. (orig.)

Persistent Mullerian Duct Syndrome with Transverse Testicular ...

African Journals Online (AJOL)

Eastham JA, McEvoy K, Sullivan R, Chandrasoma P. A case of simultaneous bilateral nonseminomatous testicular tumors in persistent müllerian duct syndrome. J Urol 1992;148:407-8. 8. Shinmura Y, Yokoi T, Tsutsui Y. A case of clear cell adenocarcinoma of the müllerian duct in persistent müllerian duct syndrome: The first ...

Idiopathic chylopericardium treated by percutaneous thoracic duct embolization after failed surgical thoracic duct ligation

Energy Technology Data Exchange (ETDEWEB)

Courtney, Malachi; Ayyagari, Raj R. [Yale School of Medicine, Yale New Haven Hospital, New Haven, CT (United States); Division of Interventional Radiology, Department of Radiology, 789 Howard Avenue, P.O. Box 208042, New Haven, CT (United States)

2015-06-15

Chylopericardium rarely occurs in pediatric patients, but when it does it is most often a result of lymphatic injury during cardiothoracic surgery. Primary idiopathic chylopericardium is especially rare, with few cases in the pediatric literature. We report a 10-year-old boy who presented with primary idiopathic chylopericardium after unsuccessful initial treatment with surgical lymphatic ligation and creation of a pericardial window. Following readmission to the hospital for a right-side chylothorax resulting from the effluent from the pericardial window, he had successful treatment by interventional radiology with percutaneous thoracic duct embolization. This case illustrates the utility of thoracic duct embolization as a less-invasive alternative to surgical thoracic duct ligation, or as a salvage procedure when surgical ligation fails. (orig.)

Idiopathic chylopericardium treated by percutaneous thoracic duct embolization after failed surgical thoracic duct ligation

International Nuclear Information System (INIS)

Courtney, Malachi; Ayyagari, Raj R.

2015-01-01

Chylopericardium rarely occurs in pediatric patients, but when it does it is most often a result of lymphatic injury during cardiothoracic surgery. Primary idiopathic chylopericardium is especially rare, with few cases in the pediatric literature. We report a 10-year-old boy who presented with primary idiopathic chylopericardium after unsuccessful initial treatment with surgical lymphatic ligation and creation of a pericardial window. Following readmission to the hospital for a right-side chylothorax resulting from the effluent from the pericardial window, he had successful treatment by interventional radiology with percutaneous thoracic duct embolization. This case illustrates the utility of thoracic duct embolization as a less-invasive alternative to surgical thoracic duct ligation, or as a salvage procedure when surgical ligation fails. (orig.)

Numerical Analysis of Indoor Sound Quality Evaluation Using Finite Element Method

Directory of Open Access Journals (Sweden)

Yu-Tuan Chou

2013-01-01

Full Text Available Indoors sound field distribution is important to Room Acoustics, but the field suffers numerous problems, for example, multipath propagation and scattering owing to sound absorption by furniture and other aspects of décor. Generally, an ideal interior space must have a sound field with clear quality. This provides both the speaker and the listener with a pleasant conversational environment. This investigation uses the Finite Element Method to assess the acoustic distribution based on the indoor space and chamber volume. In this situation, a fixed sound source at different frequencies is used to simulate the acoustic characteristics of the indoor space. This method considers the furniture and decoration sound absorbing material and thus different sound absorption coefficients and configurations. The preliminary numerical simulation provides a method that can forecast the distribution of sound in an indoor room in complex situations. Consequently, it is possible to arrange interior furnishings and appliances to optimize acoustic distribution and environmental friendliness. Additionally, the analytical results can also be used to calculate the Reverberation Time and speech intelligibility for specified indoor space.

Parotid Duct Repair with Intubation Tube: Technical Note

Science.gov (United States)

Öztürk, Muhammed Beşir; Barutca, Seda Asrufoğlu; Keskin, Elif Seda; Atik, Bekir

2017-01-01

The parotid duct can be damaged in traumatic injuries and surgical interventions. Early diagnosis and treatment of a duct injury is of great importance because complications such as sialocele and salivary gland fistula may develop if the duct is not surgically repaired. We think the cuff of an intubation tube is an ideal material in parotid duct repair, because of its technical characteristics, easiness of availability, and low-cost. In this paper, we described the use of the cuff cannula of an intubation tube for the diagnosis and treatment of parotid duct laceration, as a low-cost and easy to access material readily available in every operating room. PMID:28713751

Dispersion properties of ducted whistlers, generated by lightning discharge

Directory of Open Access Journals (Sweden)

D. L. Pasmanik

2005-06-01

Full Text Available Whistler-mode wave propagation in magnetospheric ducts of enhanced cold plasma density is studied. The case of the arbitrary ratio of the duct radius to the whistler wavelength is considered, where the ray-tracing method is not applicable. The set of duct eigenmodes and their spatial structure are analysed and dependencies of eigenmode propagation properties on the duct characteristics are studied. Special attention is paid to the analysis of the group delay time of one-hop propagation of the whistler wave packet along the duct. We found that, in contrast to the case of a wide duct, the group delay time in a rather narrow duct decreases as the eigenmode number increases. The results obtained are suggested for an explanation of some types of multi-component whistler signals.

Different Structures of PVA Nano fibrous Membrane for Sound Absorption Application

International Nuclear Information System (INIS)

Mohrova, J.; Kalinova, K.

2012-01-01

The thin nano fibrous layer has different properties in the field of sound absorption in comparison with porous fibrous material which works on a principle of friction of air particles in contact with walls of pores. In case of the thin nano fibrous layer, which represents a sound absorber here, the energy of sonic waves is absorbed by the principle of membrane resonance. The structure of the membrane can play an important role in the process of converting the sonic energy to a different energy type. The vibration system acts differently depending on the presence of smooth fibers in the structure, amount of partly merged fibers, or structure of polymer foil as extreme. Polyvinyl alcohol (PVA) was used as a polymer because of its good water solubility. It is possible to influence the structure of nano fibrous layer during the production process thanks to this property of polyvinyl alcohol.

Experimental methodology for obtaining sound absorption coefficients

Directory of Open Access Journals (Sweden)

Carlos A. Macía M

2011-07-01

Full Text Available Objective: the authors propose a new methodology for estimating sound absorption coefficients using genetic algorithms. Methodology: sound waves are generated and conducted along a rectangular silencer. The waves are then attenuated by the absorbing material covering the silencer’s walls. The attenuated sound pressure level is used in a genetic algorithm-based search to find the parameters of the proposed attenuation expressions that include geometric factors, the wavelength and the absorption coefficient. Results: a variety of adjusted mathematical models were found that make it possible to estimate the absorption coefficients based on the characteristics of a rectangular silencer used for measuring the attenuation of the noise that passes through it. Conclusions: this methodology makes it possible to obtain the absorption coefficients of new materials in a cheap and simple manner. Although these coefficients might be slightly different from those obtained through other methodologies, they provide solutions within the engineering accuracy ranges that are used for designing noise control systems.

Solitary intrahepatic bile-duct cyst presenting with Jaundice

International Nuclear Information System (INIS)

Park, Jeong Mi; Chun, Ki Sung; Ha, Hyun Kwon; Shinn, Kyung Sub; Bahk, Yong Whee; Kim, Jun Gi

1989-01-01

Caroli's disease is an uncommon condition, and characterized by congenital segmental saccular dilatation of intrahepatic bile ducts. A case of Caroli's disease, manifested by only a large communicating cystic dilatation of left intrahepatic bile duct and causing extrinsic pressure over the extrahepatic bile duct, is presented. The patient was 43-year-old housewife, hospitalized because of abdominal distension and severe jaundice. To relieve jaundice and alleviate surgical intervention, percutaneous drainage of the bile-duct cyst preceded surgery

Novel Application of Glass Fibers Recovered From Waste Printed Circuit Boards as Sound and Thermal Insulation Material

Science.gov (United States)

Sun, Zhixing; Shen, Zhigang; Ma, Shulin; Zhang, Xiaojing

2013-10-01

The aim of this study is to investigate the feasibility of using glass fibers, a recycled material from waste printed circuit boards (WPCB), as sound absorption and thermal insulation material. Glass fibers were obtained through a fluidized-bed recycling process. Acoustic properties of the recovered glass fibers (RGF) were measured and compared with some commercial sound absorbing materials, such as expanded perlite (EP), expanded vermiculite (EV), and commercial glass fiber. Results show that RGF have good sound absorption ability over the whole tested frequency range (100-6400 Hz). The average sound absorption coefficient of RGF is 0.86, which is prior to those of EP (0.81) and EV (0.73). Noise reduction coefficient analysis indicates that the absorption ability of RGF can meet the requirement of II rating for sound absorbing material according to national standard. The thermal insulation results show that RGF has a fair low thermal conductivity (0.046 W/m K), which is comparable to those of some insulation materials (i.e., EV, EP, and rock wool). Besides, an empirical dependence of thermal conductivity on material temperature was determined for RGF. All the results showed that the reuse of RGF for sound and thermal insulation material provided a promising way for recycling WPCB and obtaining high beneficial products.

MRI ductography of contrast agent distribution and leakage in normal mouse mammary ducts and ducts with in situ cancer.

Science.gov (United States)

Markiewicz, Erica; Fan, Xiaobing; Mustafi, Devkumar; Zamora, Marta; Conzen, Suzanne D; Karczmar, Gregory S

2017-07-01

High resolution 3D MRI was used to study contrast agent distribution and leakage in normal mouse mammary glands and glands containing in situ cancer after intra-ductal injection. Five female FVB/N mice (~19weeks old) with no detectable mammary cancer and eight C3(1) SV40 Tag virgin female mice (~15weeks old) with extensive in situ cancer were studied. A 34G, 45° tip Hamilton needle with a 25μL Hamilton syringe was inserted into the tip of the nipple and approximately 15μL of a Gadodiamide was injected slowly over 1min into the nipple and throughout the duct on one side of the inguinal gland. Following injection, the mouse was placed in a 9.4T MRI scanner, and a series of high resolution 3D T1-weighted images was acquired with a temporal resolution of 9.1min to follow contrast agent leakage from the ducts. The first image was acquired at about 12min after injection. Ductal enhancement regions detected in images acquired between 12 and 21min after contrast agent injection was five times smaller in SV40 mouse mammary ducts (pcontrast agent from the SV40 ducts. The contrast agent washout rate measured between 12min and 90min after injection was ~20% faster (p<0.004) in SV40 mammary ducts than in FVB/N mammary ducts. These results may be due to higher permeability of the SV40 ducts, likely due to the presence of in situ cancers. Therefore, increased permeability of ducts may indicate early stage breast cancers. Copyright © 2017 Elsevier Inc. All rights reserved.

Effect of the three-dimensional microstructure on the sound absorption of foams: A parametric study.

Science.gov (United States)

Chevillotte, Fabien; Perrot, Camille

2017-08-01

The purpose of this work is to systematically study the effect of the throat and the pore sizes on the sound absorbing properties of open-cell foams. The three-dimensional idealized unit cell used in this work enables to mimic the acoustical macro-behavior of a large class of cellular solid foams. This study is carried out for a normal incidence and also for a diffuse field excitation, with a relatively large range of sample thicknesses. The transport and sound absorbing properties are numerically studied as a function of the throat size, the pore size, and the sample thickness. The resulting diagrams show the ranges of the specific throat sizes and pore sizes where the sound absorption grading is maximized due to the pore morphology as a function of the sample thickness, and how it correlates with the corresponding transport parameters. These charts demonstrate, together with typical examples, how the morphological characteristics of foam could be modified in order to increase the visco-thermal dissipation effects.

Using A Priori Information to Improve Atmospheric Duct Estimation

Science.gov (United States)

Zhao, X.

2017-12-01

Knowledge of refractivity condition in the marine atmospheric boundary layer (MABL) is crucial for the prediction of radar and communication systems performance at frequencies above 1 GHz on low-altitude paths. Since early this century, the `refractivity from clutter (RFC)' technique has been proved to be an effective way to estimate the MABL refractivity structure. Refractivity model is very important for RFC techniques. If prior knowledge of the local refractivity information is available (e.g., from numerical weather prediction models, atmospheric soundings, etc.), more accurate parameterized refractivity model can be constructed by the statistical method, e.g. principal analysis, which in turn can be used to improve the quality of the local refractivity retrievals. This work extends the adjoint parabolic equation approach to range-varying atmospheric duct structure inversions, in which a linear empirical reduced-dimension refractivity model constructed from the a priori refractive information is used.

Effectiveness of duct sealing and duct insulation in multi-family buildings. Final report

Energy Technology Data Exchange (ETDEWEB)

Karins, N.H.; Tuluca, A.; Modera, M.

1997-07-01

This research investigated the cost-effectiveness of sealing and insulating the accessible portions of duct systems exposed to unconditioned areas in multifamily housing. Airflow and temperature measurements were performed in 25 apartments served by 10 systems a 9 multi-family properties. The measurements were performed before and after each retrofit, and included apartment airflow (supply and return), duct system temperatures, system fan flow and duct leakage area. The costs for each retrofit were recorded. The data were analyzed and used to develop a prototypical multifamily house. This prototype was used in energy simulations (DOE-2.1E) and air infiltration simulations (COMIS 2.1). The simulations were performed for two climates: New York City and Albany. In each climate, one simulation was performed assuming the basement was tight, and another assuming the basement was leaky. Simulation results and average retrofit costs were used to calculate cost-effectiveness. The results of the analysis indicate that sealing leaks of the accessible ductwork is cost-effective under all conditions simulated (simple payback was between 3 and 4 years). Insulating the accessible ductwork, however, is only cost-effective for buildings with leaky basement, in both climates (simple paybacks were less than 5 years). The simple payback period for insulating the ducts in buildings with tight basements was greater than 10 years, the threshold of cost-effectiveness for this research. 13 refs., 5 figs., 27 tabs.

ß-adrenergic regulation of ion transport in pancreatic ducts: Patch-clamp study of isolated rat pancreatic ducts

DEFF Research Database (Denmark)

Novak, I

1998-01-01

BACKGROUND & AIMS: In the intact pancreas, bicarbonate secretion is thought to be controlled by a number of regulators, including adrenergic agonists. The aim of this study was to investigate the effects of adrenergic agonists on pancreatic ducts, which are the site of bicarbonate secretion....... METHODS: Small intralobular ducts were isolated from rat pancreas and studied in vitro by the whole-cell patch clamp technique. Cell membrane voltages and currents were indicators of cellular ion transport. In some ducts, intracellular Ca2+ activity was measured by fluorescence optical methods. RESULTS...

Pressure analysis in ventilation ducts at bituminization facility

International Nuclear Information System (INIS)

Kikuchi, Naoki; Iimura, Masato; Takahashi, Yuki; Omori, Eiichi; Yamanouchi, Takamichi

1997-09-01

Pressure analysis in cell ventilation ducts at bituminization facility where the fire and explosion accident occured was carried out. This report also describes the results of bench mark calculations for computer code EVENT84 which was used for the accident analysis. The bench mark calculations were performed by comparing the analytical results by EVENT84 code with the experimental data of safety demonstration tests of ventilation system which were carried out by JAERI. We confirmed the applicability of EVENT84 code with the conservative results. The pressure analysis in cell ventilation ducts at bituminization facility were performed by comparing the analytical results of duct pressure by EVENT84 code with the yield stress of destroyed ducts by explosion, in order to estimate the scale of explosion. As a result, we could not explain the damage of ducts quantitatively, but we found the local pressure peaks analytically in downstream ducts where the serious damages were observed. (author)

Duct Remediation Program: Engineered access research and construction

International Nuclear Information System (INIS)

Beckman, T.D.; Davis, M.M.; Karas, T.M.

1992-01-01

The Rocky Flats Plant, Duct Remediation mission concentrated on removing Plutonium Oxide from the process ductwork in the primary Plutonium processing facility. When possible, remediation took place from existing process gloveboxes. Fifteen locations were identified, however, that required accessing duct runs where no process gloveboxes existed. The building's second floor utility areas had many locations where long, inaccessible duct runs were prevalent. Consequently, an extensive program for design, procurement and construction was initiated to contain and isolate ducts for penetration when existing glovebox sites were not present

Consistent approach to air-cleaning system duct design

International Nuclear Information System (INIS)

Miller, W.H.; Ornberg, S.C.; Rooney, K.L.

1981-01-01

Nuclear power plant air-cleaning system effectiveness is dependent on the capability of a duct system to safely convey contaminated gas to a filtration unit and subsequently to a point of discharge. This paper presents a logical and consistent design approach for selecting sheet metal ductwork construction to meet applicable criteria. The differences in design engineers' duct construction specifications are acknowledged. Typical duct construction details and suggestions for their effective use are presented. Improvements in duct design sections of ANSI/ASME N509-80 are highlighted. A detailed leakage analysis of a control room HVAC system is undertaken to illustrate the effects of conceptual design variations on duct construction requirements. Shortcomings of previously published analyses and interpretations of a current standard are included

Applied acoustics concepts, absorbers, and silencers for acoustical comfort and noise control alternative solutions, innovative tools, practical examples

CERN Document Server

Fuchs, Helmut V

2013-01-01

The author gives a comprehensive overview of materials and components for noise control and acoustical comfort. Sound absorbers must meet acoustical and architectural requirements, which fibrous or porous material alone can meet. Basics and applications are demonstrated, with representative examples for spatial acoustics, free-field test facilities and canal linings. Acoustic engineers and construction professionals will find some new basic concepts and tools for developments in order to improve acoustical comfort. Interference absorbers, active resonators and micro-perforated absorbers of different materials and designs complete the list of applications.

Parotid salivary duct stenosis following caudal maxillectomy.

Science.gov (United States)

Mestrinho, Lisa A; Faísca, Pedro B; Niza, Maria M R E

2014-01-01

Parotid salivary duct dilation was diagnosed in a 9-year-old male dog. The dog had undergone caudal maxillectomy on the ipsilateral side 2-years prior to presentation. Treatment consisted of parotid salivary duct excision and superficial parotidectomy that lead to the resolution of clinical signs. Transient facial neuropraxia was observed immediately after surgery and resolved spontaneously after 2-weeks. Parotid salivary duct dilation should be considered as a chronic postoperative complication following caudal maxillectomy.

Airborne sound insulation evaluation and flanking path prediction of coupled room

Science.gov (United States)

Tassia, R. D.; Asmoro, W. A.; Arifianto, D.

2016-11-01

One of the parameters to review the acoustic comfort is based on the value of the insulation partition in the classroom. The insulation value can be expressed by the sound transmission loss which converted into a single value as weighted sound reduction index (Rw, DnTw) and also have an additional sound correction factor in low frequency (C, Ctr) .In this study, the measurements were performed in two positions at each point using BSWA microphone and dodecahedron speaker as the sound source. The results of field measurements indicate the acoustic insulation values (DnT w + C) is 19.6 dB. It is noted that the partition wall not according to the standard which the DnTw + C> 51 dB. Hence the partition wall need to be redesign to improve acoustic insulation in the classroom. The design used gypsum board, plasterboard, cement board, and PVC as the replacement material. Based on the results, all the material is simulated in accordance with established standards. Best insulation is cement board with the insulation value is 69dB, the thickness of 12.5 mm on each side and the absorber material is 50 mm. Many factors lead to increase the value of acoustic insulation, such as the thickness of the panel, the addition of absorber material, density, and Poisson's ratio of a material. The prediction of flanking path can be estimated from noise reduction values at each measurement point in the class room. Based on data obtained, there is no significant change in noise reduction from each point so that the pathway of flanking is not affect the sound transmission in the classroom.

Magnetic resonance imaging of Muellerian duct anomalies in children

International Nuclear Information System (INIS)

Li, Yi; Phelps, Andrew; Zapala, Matthew A.; MacKenzie, John D.; MacKenzie, Tippi C.; Courtier, Jesse

2016-01-01

Muellerian duct anomalies encompass a wide variety of disorders resulting from abnormalities in the embryological development of the Muellerian ducts. In the prepubertal pediatric population, Muellerian duct anomalies are often incidental findings on studies obtained for other reasons. The onset of menses can prompt more clinical symptoms. Proper characterization of Muellerian duct anomalies is important because these anomalies can affect the development of gynecological disorders as well as fertility. Muellerian duct anomalies also carry a high association with other congenital anomalies, particularly renal abnormalities. MRI is widely considered the best modality for assessing Muellerian duct anomalies; it provides multiplanar capability, clear anatomical detail and tissue characterization without ionizing radiation. MRI allows for careful description of Muellerian duct anomalies, often leading to classification into the most widely accepted classification system for Muellerian duct anomalies. This system, developed by the American Society of Reproductive Medicine, includes seven subtypes: uterine agenesis/hypoplasia, unicornuate, didelphys, bicornuate, septate, arcuate, and diethylstilbestrol (DES) drug-related uterus. In cases of complex anomalies that defy classification, MRI allows detailed depiction of all components of the anatomical abnormality, allowing for proper management and surgical planning. (orig.)

Water condensation promotes fungal growth in ventilation ducts

Energy Technology Data Exchange (ETDEWEB)

Pasanen, P.; Pasanen, A.-L. (University of Kupopio, Department of Environmental Sciences, Kuopio (Finland)); Jantunen, M. (National Public Health Institute, Kuopio (Finland))

1993-01-01

In a subarctic climate the diurnal variation in temperature may cause water condensation in ducts placed in the unheated spaces of a building. In this study, germination time and sporulation of a fungus, Penicillium verrucosum, were studied on dusty, galvanized steel sheet under different moisture conditions at room temperature. The effect of condensed water in a supply air duct on spore amplification was studied in an experimental ventilation set-up. In the field, air temperatures and the dew point temperature of air in the duct were monitored continuously for a week. P. verrucosum germinated on steel surfaces during five-hour incubation of the surface under humid conditions, when the surface has been moist for half an hour, germ tubes appeared within 17 hours. During 24-hour incubation under moist conditions, P. verrucosum produced hyphae and spores. In the experimental set-up the airborne spore counts increased when the air passed through a water-condensing section of the duct. Penicillium was the most abundant fungus sporulated on the moist duct surface. In the field, during humid weather, the surface temperature on the air stream surface decreased to the dew point temperature of the air in the duct. thus water condensation in air ducts may promote fungal growth. (au)

Risk factors for central bile duct injury complicating partial liver resection

NARCIS (Netherlands)

Boonstra, E. A.; de Boer, M. T.; Sieders, E.; Peeters, P. M. J. G.; de Jong, K. P.; Slooff, M. J. H.; Porte, R. J.

Background: Bile duct injury is a serious complication following liver resection. Few studies have differentiated between leakage from small peripheral bile ducts and central bile duct injury (CBDI), defined as an injury leading to leakage or stenosis of the common bile duct, common hepatic duct,

Optimum design of the injection duct system of a stenter machine

Energy Technology Data Exchange (ETDEWEB)

Juraeva, Makhsuda; Song, Dong Joo [Yeungnam University, Geyongsan (Korea, Republic of); Ryu, Kyung Jin [Ajou Motor College, Boryeong (Korea, Republic of)

2017-05-15

Stenter machines are used for drying fabrics in the textile industry and have a heater, injection duct system, and fans inside a chamber. The injection duct system has ducts and air-injecting holes. Plane-type injection duct systems were investigated to obtain uniform airflow at the air-injecting holes. The flow field of the injection duct systems was computed using ANSYS CFX with different heights of the duct end and different shapes for the air-injecting holes. There was a high mass flow rate at the air-injecting holes and high airflow circulation inside both plane-type and mountain-type ducts at the ends. The height of the duct end was varied between 40 mm and 160 mm. The injection duct systems were analyzed with four different shapes of air-injecting holes. The circular and elliptical holes had lower standard deviations of the mass flow rate than other shapes. Relatively uniform mass flow rates were obtained in the plane-type and mountain-type duct systems when the height of the duct end was 40 mm and the shape of the air-injecting holes was circular or elliptical. The developed injection duct systems were improved by obtaining a uniform mass flow rate at the air-injecting holes. A stenter prototype was fabricated with the developed injection duct system to confirm the numerical results. The developed injection duct system had better performance than the original system.

WAVE PROPAGATION in the HOT DUCT of VHTR

Energy Technology Data Exchange (ETDEWEB)

Richard Schultz; Jim C. P. Liou

2013-07-01

In VHTR, helium from the reactor vessel is conveyed to a power conversion unit through a hot duct. In a hypothesized Depressurized Conduction Cooldown event where a rupture of the hot duct occurs, pressure waves will be initiated and reverberate in the hot duct. A numerical model is developed to quantify the transients and the helium mass flux through the rupture for such events. The flow path of the helium forms a closed loop but only the hot duct is modeled in this study. The lower plum of the reactor vessel and the steam generator are treated as specified pressure and/or temperature boundary to the hot duct. The model is based on the conservation principles of mass, momentum and energy, and on the equations of state for helium. The numerical solution is based on the method of characteristics with specified time intervals with a predictor and corrector algorithm. The rupture sub-model gives reasonable results. Transients induced by ruptures with break area equaling 20%, 10%, and 5% of the duct cross-sectional area are described.

Imaging manifestation of hepatocellular carcinoma with bile duct tumor thrombi

International Nuclear Information System (INIS)

Liu Qingyu; Chen Jianyu; Liang Biling; Hu Tao

2008-01-01

Objective: To analyze the imaging features of hepatocellular carcinoma(HCC) with bile duct tumor thrombi. Methods: Thirteen patients with bile duct tumor thrombi proved pathologically underwent imaging examination. MR and CT were performed in 3 cases, and 2 cases had CT only and 8 cases had MRI only. Ultrasonography(US) was performed in all 13 patients. The accuracy of bile duct tumor thrombi detection was compared between US, CT and MRI with Fisher test. Results: Liver tumors and bile duct tumor thrombi were demonstrated in all patients on CT or MRI. Presence of intraluminal soft tissue mass was found in four of five cases on CT, and mild enhancement of the intraluminal mass in the arterial phase was noted, dilated bile duct distal to tumor thrombi was detected in all five patients. Eleven Tumor thrombi showed slight low signal intensity on T 1 WI, slight high signal intensity on T 2 WI, and mild to moderate contrast enhancement on the contrast-enhanced MR images. The MRCP findings of tumor thrombi were as follows: interruption, stricture of the bile ducts or irregular filling defect in the bile ducts with dilated intrahepatic ducts, bile duet was abruptly interrupted or showed a 'rat-tail' stricture (n=5); the common bile duct was filled with tumor thrombi, intrahepatic bile duct dilatation and missing common bile duct was noted on MRCP (n=2). Bile duct tumor thrombi were correctly diagnosed in 7 cases on US, and 12 cases on CT or MRI. Six cases were misdiagnosed or miss-diagnosed on US, and 4 cases were misdiagnosed on CT or MRI. There was no significant difference between US and CT/MRI in diagnosis of bile duct tumor thrombi (P=0.270). Conclusion: CT or MR imaging is useful for the diagnosis of HCC with biliary tumor thrombi and for evaluating the extension of thrombi. (authors)

Bile duct anastomotic stricture after pediatric living donor liver transplantation.

Science.gov (United States)

Chok, Kenneth S H; Chan, See Ching; Chan, Kwong Leung; Sharr, William W; Tam, Paul K H; Fan, Sheung Tat; Lo, Chung Mau

2012-07-01

Hepaticojejunostomy is a well-accepted method, whereas duct-to-duct anastomosis is gaining popularity for bile duct reconstruction in pediatric living donor liver transplantation (LDLT). Biliary complications, especially biliary anastomotic stricture (BAS), are not clearly defined. The aim of the present study is to determine the rate of BAS and its associated risk factors. The study included 78 pediatric patients (duct-to-duct anastomosis during LDLT. The median follow-up period for the BAS group and the non-BAS group was 57.8 and 79.5 months, respectively (P = .683). Ten of the patients with BAS required percutaneous transhepatic biliary drainage with or without dilatation for treating the stricture. Multivariable analysis showed that hepatic artery thrombosis and duct-to-duct anastomosis were 2 risk factors associated with BAS. In pediatric LDLT, hepaticojejunostomy is the preferred method for bile duct reconstruction, but more large-scale research needs to be done to reconfirm this result. Copyright © 2012 Elsevier Inc. All rights reserved.

A study on CT features of intrahepatic bile duct abscess

International Nuclear Information System (INIS)

Min Pengqiu; Li Peng; He Zhiyan; Chen Weixia; Liu Yan

2001-01-01

Objective: To evaluate CT features of intrahepatic bile duct abscess (IBDA) and its pathologic basis. Methods: The CT imaging data of 31 consecutive cases of intrahepatic bile duct abscess proved by surgery or clinical treatments from October 1989 to February 1999 were retrospectively studied. The causes included acute obstructive suppurative cholangitis and retrograde infection due to different etiologies. For all the cases, the CT manifestations of liver abscess, bile duct abnormalities, and their relationship were observed respectively. Results: Manifestations of liver abscess were revealed in all cases (31/31, 100%). The CT manifestations of bile duct abnormalities included signs of etiologies caused bile duct obstruction and other signs including cholangiectasis (29/31, 93.5%), the dilated bile ducts communicated with (5/31, 16.1%) or abut on (8/31, 25.8%) the abscesses, and gas collection in bile ducts (10/31, 32.2%). The signs showing the relationship between liver abscess and bile duct abnormalities were that the abscesses complied with the obstructive site and the dilated bile ducts (15/31, 48.4%), and the liver abscesses located in different (7/31, 22.6%) or same (4/31, 12.9%) liver lobes or segments with gas collection in the dilated bile ducts. Conclusion: The CT manifestations of IBDA included signs of liver abscess, abnormalities of bile ducts, and signs showing their relationship. CT scanning was helpful in making comprehensive and accurate diagnosis of IBDA

A Comparison of Simulation Capabilities for Ducts

Energy Technology Data Exchange (ETDEWEB)

Miller, William A [ORNL; Smith, Matt K [ORNL; Gu, Lixing [Florida Solar Energy Center (FSEC); New, Joshua Ryan [ORNL

2014-11-01

Typically, the cheapest way to install a central air conditioning system in residential buildings is to place the ductwork in the attic. Energy losses due to duct-attic interactions can be great, but current whole-house models are unable to capture the dynamic multi-mode physics of the interactions. The building industry is notoriously fragmented and unable to devote adequate research resources to solve this problem. Builders are going to continue to put ducts in the attic because floor space is too expensive to closet them within living space, and there are both construction and aesthetic issues with other approaches such as dropped ceilings. Thus, there is a substantial need to publicly document duct losses and the cost of energy used by ducts in attics so that practitioners, builders, homeowners and state and federal code officials can make informed decisions leading to changes in new construction and additional retrofit actions. Thus, the goal of this study is to conduct a comparison of AtticSim and EnergyPlus simulation algorithms to identify specific features for potential inclusion in EnergyPlus that would allow higher-fidelity modeling of HVAC operation and duct transport of conditioned air. It is anticipated that the resulting analysis from these simulation tools will inform energy decisions relating to the role of ducts in future building energy codes and standards.

Sound attenuations of axial fan blade tones using flow-driven tunable resonator arrays

Science.gov (United States)

Gorny, Lee James

Flow-excited, tunable quarter-wavelength resonators can be integrated into the shrouds of ducted subsonic axial fans. This study explores their effectiveness in reducing propagations of tonal noise by means of acoustic wave cancellation. Resonators are a non-intrusive method of generating a secondary sound field near the plane of a rotor. As they can be strategically tuned to reduce radiated noise at the blade passage frequency (BPF) and its harmonics, resonators can be useful for a variety of applications to quiet existing and future turbomachinery. Experiments have demonstrated that a single quarter wave resonator is effective in reducing unidirectional plane wave propagations for long wavelength ducted applications while an array is effective for shorter wavelength or un-ducted facilities where shrouded fans are used. Testing conducted at Center for Acoustics and Vibrations (CAV) at the Pennsylvania State University the Deutsches Zentrum fur Luft und Raumfahrt (DLR) in Berlin, Germany demonstrated that resonator arrays were effective in attenuating shorter wavelength plane-wave and higher order modal propagations of blade tone noise. A chiller fan enclosure, constructed in the CAV laboratory emulated an industrial chiller in its operation. Using this facility, resonators were observed to attenuate blade tone noise from a non-ideal ducted geometry. The approaches used in this study evolved from Helmholtz resonators to conventional quarter wave tubes, to mouth tunable resonators, and finally to back-wall tunable resonators. These developments in tuning allowed for independent control of a resonator's magnitude and phase of the secondary sound field produced by the resonators. It was demonstrated that the use of two tunable resonator chambers oriented axially on either side of the blade region enables a dipole-like secondary sound field to be passively generated and bi-directional attenuations of plane wave noise to be achieved. Tonal attenuations of 28 dB were

Bile Duct Cancer (Cholangiocarcinoma) Treatment (PDQ®)—Health Professional Version

Science.gov (United States)

Bile duct cancer (also called cholangiocarcinoma) can occur in the bile ducts in the liver (intrahepatic) or outside the liver (perihilar or distal extrahepatic). Learn about the types of bile duct cancer, risk factors, clinical features, staging, and treatment for bile duct cancer in this expert-reviewed summary.

A radiographic study of nasopalatine duct cysts

Energy Technology Data Exchange (ETDEWEB)

Jun, Chan Duck; Hwang, Eui Hwan; Lee, Sang Rae [Dept. of Oral Radiology, College of Dentistry, Kyung Hee University, Seoul (Korea, Republic of)

1993-02-15

The purpose of this study was to evaluate the clinical and radiographic features of 35 cases of nasopalatine duct cyst by means of the analysis of periapical and/or occlusal radiograms in 35 persons visited the Department of Oral and Maxillofacial Radiology, School of Dentistry, Kyung Hee University and Chonbuk National University. The obtained results were as follows: 1. The incidence of nasopalatine duct cysts was higher in males (74.3%) than in females (25.7%). 2. The nasopalatine duct cysts were the most frequently occurred in the 4th decades (34.3%). The 6th and 7th decades (17.1%, 17.1%) were next in order to frequency followed by the 5th decades (14.3%), the 3rd decades (8.6%), the 2nd decades (5.7%), and 8th decades (2.9%). 3. In the signs and symptoms of nasopalatine duct cysts, 25.7% were swelling, 17.1% were swelling and tenderness, 20.0% were swelling and pain, and 37.2% were a symptom. 4. In the shape of nasopalatine duct cysts, 40.0% were round type, 48.6% 11.8% were heart type. 5. In symmetry of the nasopalatine duct cysts, 11.4% were 6-10 mm, 48.6% were 11-20 mm, 25.7% were 21-30 mm, and 14.3% were 31-40 mm. 6. In the periphery of nasopalatine duct cysts, 82.9% were distinct, 17.1% were relatively distinct. 7. In the change of root, 51.5% were intact, 17.1% were root divergence, 20.0% were root resorption, and 11.4% were root divergence and resorption.

A radiographic study of nasopalatine duct cysts

International Nuclear Information System (INIS)

Jun, Chan Duck; Hwang, Eui Hwan; Lee, Sang Rae

1993-01-01

The purpose of this study was to evaluate the clinical and radiographic features of 35 cases of nasopalatine duct cyst by means of the analysis of periapical and/or occlusal radiograms in 35 persons visited the Department of Oral and Maxillofacial Radiology, School of Dentistry, Kyung Hee University and Chonbuk National University. The obtained results were as follows: 1. The incidence of nasopalatine duct cysts was higher in males (74.3%) than in females (25.7%). 2. The nasopalatine duct cysts were the most frequently occurred in the 4th decades (34.3%). The 6th and 7th decades (17.1%, 17.1%) were next in order to frequency followed by the 5th decades (14.3%), the 3rd decades (8.6%), the 2nd decades (5.7%), and 8th decades (2.9%). 3. In the signs and symptoms of nasopalatine duct cysts, 25.7% were swelling, 17.1% were swelling and tenderness, 20.0% were swelling and pain, and 37.2% were a symptom. 4. In the shape of nasopalatine duct cysts, 40.0% were round type, 48.6% 11.8% were heart type. 5. In symmetry of the nasopalatine duct cysts, 11.4% were 6-10 mm, 48.6% were 11-20 mm, 25.7% were 21-30 mm, and 14.3% were 31-40 mm. 6. In the periphery of nasopalatine duct cysts, 82.9% were distinct, 17.1% were relatively distinct. 7. In the change of root, 51.5% were intact, 17.1% were root divergence, 20.0% were root resorption, and 11.4% were root divergence and resorption.

Measure Guideline. Sealing and Insulating Ducts in Existing Homes

Energy Technology Data Exchange (ETDEWEB)

Aldrich, R. [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Puttagunta, S. [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States)

2011-12-01

This document begins with a discussion on potential cost and performance benefits of duct sealing and insulating. It continues with a review of typical duct materials and components and the overall procedures for assessing and improving the duct system.

A case of fascioliasis in common bile duct

Energy Technology Data Exchange (ETDEWEB)

Ham, Soo Youn; Park, Cheol Min; Chung, Kyu Byung; Lee, Chang Hong; Park, Seung Chul; Choi, Sang Yong; Lim, Han Jong [Korea University College of Medicine, Seoul (Korea, Republic of)

1989-10-15

A case of Fascioliasis of common bile duct is confirmed by visualization of adult fluke. Fascioliasis caused by Fasciola hepatica, is common parasitic disease in cattle and sheep. Human is an accidental host. ERCP demonstrated irregular linear conglomerated filling defects in common bile duct. Through surgical intervention, we found adult flukes of F. hepatica and adenomatous hyperplasia of common bile duct.

A case of fascioliasis in common bile duct

International Nuclear Information System (INIS)

Ham, Soo Youn; Park, Cheol Min; Chung, Kyu Byung; Lee, Chang Hong; Park, Seung Chul; Choi, Sang Yong; Lim, Han Jong

1989-01-01

A case of Fascioliasis of common bile duct is confirmed by visualization of adult fluke. Fascioliasis caused by Fasciola hepatica, is common parasitic disease in cattle and sheep. Human is an accidental host. ERCP demonstrated irregular linear conglomerated filling defects in common bile duct. Through surgical intervention, we found adult flukes of F. hepatica and adenomatous hyperplasia of common bile duct

Treatment Options for Extrahepatic Bile Duct Cancer

Science.gov (United States)

... Treatment Liver Cancer Prevention Liver Cancer Screening Research Bile Duct Cancer (Cholangiocarcinoma) Treatment (PDQ®)–Patient Version Treatment ... are different types of treatment for patients with bile duct cancer. Different types of treatments are available ...

Treatment Option Overview (Extrahepatic Bile Duct Cancer)

Science.gov (United States)

... Treatment Liver Cancer Prevention Liver Cancer Screening Research Bile Duct Cancer (Cholangiocarcinoma) Treatment (PDQ®)–Patient Version Treatment ... are different types of treatment for patients with bile duct cancer. Different types of treatments are available ...

General Information about Extrahepatic Bile Duct Cancer

Science.gov (United States)

... Treatment Liver Cancer Prevention Liver Cancer Screening Research Bile Duct Cancer (Cholangiocarcinoma) Treatment (PDQ®)–Patient Version Treatment ... are different types of treatment for patients with bile duct cancer. Different types of treatments are available ...

Sound amplification at a rectangular T-junction with merging mean flows

Science.gov (United States)

Du, Lin; Holmberg, Andreas; Karlsson, Mikael; Åbom, Mats

2016-04-01

This paper reports a numerical study on the aeroacoustic response of a rectangular T-junction with merging mean flows. The primary motivation of the work is to explain the high sound amplification, recently seen experimentally, when introducing a small merging bias flow. The acoustic results are found solving the compressible Linearized Navier-Stokes Equations (LNSEs) in the frequency domain, where the base flow is first obtained using RANS with a k-ε turbulence model. The model predicts the measured scattering data well, including the amplitude and Strouhal number for the peak amplification, if the effect of eddy viscosity damping is included. It is found that the base flow changes significantly with the presence of a small bias flow. Compared to pure grazing flow a strong unstable shear layer is created in the downstream main duct starting from the T-junction trailing edge. This means that the main region of vortex-sound interaction is moved away from the junction to a downstream region much larger than the junction width. To analyze the sound amplification in this region Howe's energy corollary and the growth of acoustic density are used.

A Case of Adenomyomatous Hyperplasia of the Extrahepatic Bile Duct

Directory of Open Access Journals (Sweden)

Masakatsu Numata

2011-08-01

Full Text Available Adenomyomatous hyperplasia is rarely found in the extrahepatic bile duct. A 54-year-old man was referred to our center with a diagnosis of extrahepatic bile duct stenosis which had been detected by endoscopic retrograde choloangiopancreatography. Abdominal computed tomography revealed thickening of the wall of the middle extrahepatic bile duct, however no malignant cells were detected by cytology. Since bile duct carcinoma could not be ruled out, we performed resection of the extrahepatic duct accompanied by lymph node dissection. Histopathologically, the lesion was diagnosed as adenomyomatous hyperplasia of the extrahepatic bile duct. Present and previously reported cases showed the difficulty of making a diagnosis of adenomyomatous hyperplasia of the extrahepatic bile duct preoperatively or intraoperatively. Therefore, when adenomyomatous hyperplasia is suspected, a radical surgical procedure according to malignant disease may be necessary for definitive diagnosis.

Ultrasound imaging of the mouse pancreatic duct using lipid microbubbles

Science.gov (United States)

Banerjee, B.; McKeown, K. R.; Skovan, B.; Ogram, E.; Ingram, P.; Ignatenko, N.; Paine-Murrieta, G.; Witte, R.; Matsunaga, T. O.

2012-03-01

Research requiring the murine pancreatic duct to be imaged is often challenging due to the difficulty in selectively cannulating the pancreatic duct. We have successfully catheterized the pancreatic duct through the common bile duct in severe combined immune deficient (SCID) mice and imaged the pancreatic duct with gas filled lipid microbubbles that increase ultrasound imaging sensitivity due to exquisite scattering at the gas/liquid interface. A SCID mouse was euthanized by CO2, a midline abdominal incision made, the common bile duct cut at its midpoint, a 2 cm, 32 gauge tip catheter was inserted about 1 mm into the duct and tied with suture. The duodenum and pancreas were excised, removed in toto, embedded in agar and an infusion pump was used to instill normal saline or lipid-coated microbubbles (10 million / ml) into the duct. B-mode images before and after infusion of the duct with microbubbles imaged the entire pancreatic duct (~ 1 cm) with high contrast. The microbubbles were cavitated by high mechanical index (HMI) ultrasound for imaging to be repeated. Our technique of catheterization and using lipid microbubbles as a contrast agent may provide an effective, affordable technique of imaging the murine pancreatic duct; cavitation with HMI ultrasound would enable repeated imaging to be performed and clustering of targeted microbubbles to receptors on ductal cells would allow pathology to be localized accurately. This research was supported by the Experimental Mouse Shared Service of the AZ Cancer Center (Grant Number P30CA023074, NIH/NCI and the GI SPORE (NIH/NCI P50 CA95060).

Sound and sound sources

DEFF Research Database (Denmark)

Larsen, Ole Næsbye; Wahlberg, Magnus

2017-01-01

There is no difference in principle between the infrasonic and ultrasonic sounds, which are inaudible to humans (or other animals) and the sounds that we can hear. In all cases, sound is a wave of pressure and particle oscillations propagating through an elastic medium, such as air. This chapter...... is about the physical laws that govern how animals produce sound signals and how physical principles determine the signals’ frequency content and sound level, the nature of the sound field (sound pressure versus particle vibrations) as well as directional properties of the emitted signal. Many...... of these properties are dictated by simple physical relationships between the size of the sound emitter and the wavelength of emitted sound. The wavelengths of the signals need to be sufficiently short in relation to the size of the emitter to allow for the efficient production of propagating sound pressure waves...

Hepatocellular carcinoma with bile duct involvement : computed Tomographic (CT) findings

International Nuclear Information System (INIS)

Lee, Joon Woo; Han, Joon Koo; Kim, Tae Kyoung; And others

2000-01-01

To describe the radiologic features of computed tomography (CT) in hepatocellular carcinoma (HCC) with bile duct involvement. We retrospectively analyzed the two phase spiral CT findings of 31 patients in whom HCC with bile duct invasion (n=3D28) or compression (n=3D3), was diagnosed. Eight of these underwent follow up CT after transarterial chemoembolization. We analyzed the size, type, location, enhancement pattern, and lipiodol retention of parenchymal and intraductal masses, as well as their lymphadenopathy. In all patients with bile duct invasion, single or multiple masses were demonstrated in the bile ducts. Intraductal masses showed the same enhancement characteristics as the parenchymal mass (kappa 0.550, p less than 0.001), and were contiguous to this mass. In 14 of 28 patients, intraductal masses filled the peripheral intrahepatic bile ducts and extended to the common bile ducts. In the other 14, the parenchymal mass extended to the area of the porta hepatis and then directly invaded the large ducts. In nine of the 28 patients, there was a hypoattenuated cleft between the intraductal mass and ductal wall. In six, a parenchymal mass was not apparent (n=3D2), or was smaller than 2cm (n=3D4). In five of eight patients (62.5%), follow-up CT after transarterial chemoembolization showed compact or partial lipiodol retention within the intraductal mass. In patients with bile duct compression, perihilar lymph nodes were noted along with the dilated intrahepatic duct but no intra ductal mass was demonstrated in the duct. Hepatocellular carcinomas cause bile duct dilatation either by direct invasion or by extrinsic compression of the bile duct with surrounding enlarged nodes. For the diagnosis of this condition, CT is helpful. (author)

Analysis and Optimal Condition of the Rear-Sound-Aided Control Source in Active Noise Control

Directory of Open Access Journals (Sweden)

Karel Kreuter

2011-01-01

Full Text Available An active noise control scenario of simple ducts is considered. The previously suggested technique of using an single loudspeaker and its rear sound to cancel the upstream sound is further examined and compared to the bidirectional solution in order to give theoretical proof of its advantage. Firstly, a model with a new approach for taking damping effects into account is derived based on the electrical transmission line theory. By comparison with the old model, the new approach is validated, and occurring differences are discussed. Moreover, a numerical application with the consideration of damping is implemented for confirmation. The influence of the rear sound strength on the feedback-path system is investigated, and the optimal condition is determined. Finally, it is proven that the proposed source has an advantage of an extended phase lag and a time delay in the feedback-path system by both frequency-response analysis and numerical calculation of the time response.

Self-made metal stent in treatment of nasolacrimal duct obstruction

International Nuclear Information System (INIS)

Du Wei; Pang Ruilin; Luo Gang; Gu Jingchuan; Gong Yongxiang

2003-01-01

Objective: To evaluate application of self-made metal stent in treatment of nasolacrimal duct obstruction. Methods: In total 15 cases, self-made metal stents made of stainless steel wire were implanted in 18 obstructed nasolacrimal ducts. The lacrimal passages were rinsed and re-canalized followed by antegrade inserting the guide wire from upper dacryon. A dilator was inserted over the guide wire, and then a stent was released from a sheath into the impaired section of nasolacrimal duct. Dacryocystography was performed before and after the interventional procedure. Results: Dacryocystography showed patent nasolacrimal duct after treatment. Epiphora disappeared completely in 11 cases (13 ducts), improved in 4 cases (5 ducts). These cases had been followed up for 61-219 days (167 days in average). Relapse was found in 2 cases (2 ducts) in three months. Those 2 stents were removed by surgical procedure and found occluded by granulation. Conclusion: Interventional placement of the self-made metal stent is a simple, safe, low-cost and effective treatment of the nasolacrimal duct obstruction

Cystic duct remnant mucocele in a liver transplant recipient

International Nuclear Information System (INIS)

Ahlawat, Sushil K.; Fishbien, Thomas M.; Haddad, Nadim G.

2008-01-01

Cystic duct remnant mucocele is an extremely rare complication of liver transplantation in children. Surgical correction is usually required for cystic duct remnant mucocele when it causes biliary obstruction. We describe a 14-month-old liver transplant recipient who presented with biliary obstruction 1 month after orthotopic liver transplantation with an end-to-end choledochocholedocal biliary anastomosis for hepatoblastoma. US, CT and cholangiography findings were consistent with mucocele of the allograft cystic duct remnant. Surgery was not needed in our patient because the mucocele and biliary obstruction had resolved on repeat imaging most likely due to guidewire manipulation during cholangiography, resulting in opening of the cystic duct remnant orifice and drainage into the common duct. (orig.)

Cystic duct remnant mucocele in a liver transplant recipient

Energy Technology Data Exchange (ETDEWEB)

Ahlawat, Sushil K. [Georgetown University Hospital, Department of Medicine, Division of Gastroenterology, Washington, DC (United States); University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark, NJ (United States); Fishbien, Thomas M. [Georgetown University Hospital, Department of Medicine, Division of Gastroenterology, Washington, DC (United States); Haddad, Nadim G. [Georgetown University Hospital, Department of Surgery, Division of Transplant Surgery, Washington, DC (United States)

2008-08-15

Cystic duct remnant mucocele is an extremely rare complication of liver transplantation in children. Surgical correction is usually required for cystic duct remnant mucocele when it causes biliary obstruction. We describe a 14-month-old liver transplant recipient who presented with biliary obstruction 1 month after orthotopic liver transplantation with an end-to-end choledochocholedocal biliary anastomosis for hepatoblastoma. US, CT and cholangiography findings were consistent with mucocele of the allograft cystic duct remnant. Surgery was not needed in our patient because the mucocele and biliary obstruction had resolved on repeat imaging most likely due to guidewire manipulation during cholangiography, resulting in opening of the cystic duct remnant orifice and drainage into the common duct. (orig.)

Bowing-reactivity trends in EBR-II assuming zero-swelling ducts

International Nuclear Information System (INIS)

Meneghetti, D.

1994-01-01

Predicted trends of duct-bowing reactivities for the Experimental Breeder Reactor II (EBR-II) are correlated with predicted row-wise duct deflections assuming use of idealized zero-void-swelling subassembly ducts. These assume no irradiation induced swellings of ducts but include estimates of the effects of irradiation-creep relaxation of thermally induced bowing stresses. The results illustrate the manners in which at-power creeps may affect subsequent duct deflections at zero power and thereby the trends of the bowing component of a subsequent power reactivity decrement

[Bile duct lesions in laparoscopic cholecystectomy].

Science.gov (United States)

Siewert, J R; Ungeheuer, A; Feussner, H

1994-09-01

Laparoscopic cholecystectomy is both resulting in a slightly higher incidence of biliary lesions and a change of prevalence of the type of lesions. Damage to the biliary system occurs in 4 different types: The most severe case is the lesion with a structural defect of the hepatic or common bile duct with (IVa) or without (IVb) vascular injury. Tangential lesions without structural loss of the duct should be denominated as type III (IIIa with additional lesion to the vessels, type IIIb without). Type II comprehends late strictures without obvious intraoperative trauma to the duct. Type I includes immediate biliary fistulae of usually good prognosis. The increasing prevalence of structural defects of the bile ducts appears to be a peculiarity of laparoscopic cholecystectomy necessitating highly demanding operative repair. In the majority of cases, hepatico-jejunostomy or even intraparenchymatous anastomoses are required. Adaptation of well proven principles of open surgery is the best prevention of biliary lesions in laparoscopic cholecystectomy as well as the readiness to convert early to the open procedure.

Depressurization test on hot gas duct

International Nuclear Information System (INIS)

Tanihira, Masanori; Kunitomi; Kazuhiko; Inagaki, Yoshiyuki; Miyamoto, Yoshiaki; Sato, Yutaka.

1989-05-01

To study the integrity of internal structures and the characteristics in a hot gas duct under the rapid depressurization accident, depressurization tests have been carried out using a test apparatus installed the hot gas duct with the same size and the same structures as that of the High Temperature Engineering Test Reactor (HTTR). The tests have been performed with three parameters: depressurization rate (0.14-3.08 MPa/s) determined by orifice diameter, area of the open space at the slide joint (11.9-2036 mm 2 ), and initial pressure (1.0-4.0 MPa) filled up in a pressure vessel, by using nitrogen gas and helium gas. The maximum pressure difference applied on the internal structures of the hot gas duct was 2.69 MPa on the liner tube and 0.45 MPa on the separating plate. After all tests were completed, the hot gas duct which was used in the tests was disassembled. Inspection revealed that there were no failure and no deformation on the internal structures such as separating plates, insulation layers, a liner tube and a pressure tube. (author)

Ultrasound appearance of chronic mammary duct ectasia

Energy Technology Data Exchange (ETDEWEB)

Duchesne, N. [Ottawa Hospital, Dept. of Radiology, Ottawa, Ontario (Canada)]. E-mail: nathalie_duchesne_22@yahoo.ca; Skolnik, S. [Univ. of Toronto, Dept. of Family Medicine, Toronto, Ontario (Canada); Bilmer, S. [Ottawa Hospital, Dept. of Radiology, Ottawa, Ontario (Canada)

2005-12-15

Mammary duct ectasia (MDE), also called periductal mastitis, mammary dysplasia, or plasma cell mastitis, is a benign condition of the mammary gland first described by Haagensen in 1951. The etiology of MDE is unknown and its pathogenesis still controversial; the periductal inflammation could be either the cause or the result of dilated damaged ducts. The process is usually bilateral and asymptomatic, with only a small percentage of patients presenting with symptoms that may include long course of tumour formation, usually subareolar breast lumps, nipple discharge, nipple retraction, mastalgia, and mammary abscess or fistulas. Mammographic presentation of MDE is well known; its features include periductal calcification, benign intraductal calcification, and retroareolar duct dilatation. The periductal calcification results from dystrophic calcification and forms calcified rings or very dense, oval, elongated calcifications, each with a central lucency representing the dilated duct. Intraductal calcifications of duct ectasia represent inspissated intraductal material and are typically of uniform high density, often needle-like, and occasionally branching. Occasionally, there are no mammographic findings, and the diagnosis must rely on sonographic features. Appearance of MDE on ultrasonography (US) depends on the stage of the disease and the contents of the dilated ducts. The acute presentation has been demonstrated in the literature more often than has its chronic counterpart. In the former, duct content can vary from anechoic to isoechoic with surrounding fatty tissue. In chronic MDE, episodes of inflammation are longer. This tends to result in secretions that have a more solid, cheesy texture, partly due to cholesterol crystals, foam cells, and inflammatory cells. For both types of MDE, the appearance can mimic high-grade ductal carcinoma in situ (DCIS) on US. In this essay, 2 chronic MDE cases are presented and their US appearance discussed. Our goal is to explore

Ultrasound appearance of chronic mammary duct ectasia

International Nuclear Information System (INIS)

Duchesne, N.; Skolnik, S.; Bilmer, S.

2005-01-01

Mammary duct ectasia (MDE), also called periductal mastitis, mammary dysplasia, or plasma cell mastitis, is a benign condition of the mammary gland first described by Haagensen in 1951. The etiology of MDE is unknown and its pathogenesis still controversial; the periductal inflammation could be either the cause or the result of dilated damaged ducts. The process is usually bilateral and asymptomatic, with only a small percentage of patients presenting with symptoms that may include long course of tumour formation, usually subareolar breast lumps, nipple discharge, nipple retraction, mastalgia, and mammary abscess or fistulas. Mammographic presentation of MDE is well known; its features include periductal calcification, benign intraductal calcification, and retroareolar duct dilatation. The periductal calcification results from dystrophic calcification and forms calcified rings or very dense, oval, elongated calcifications, each with a central lucency representing the dilated duct. Intraductal calcifications of duct ectasia represent inspissated intraductal material and are typically of uniform high density, often needle-like, and occasionally branching. Occasionally, there are no mammographic findings, and the diagnosis must rely on sonographic features. Appearance of MDE on ultrasonography (US) depends on the stage of the disease and the contents of the dilated ducts. The acute presentation has been demonstrated in the literature more often than has its chronic counterpart. In the former, duct content can vary from anechoic to isoechoic with surrounding fatty tissue. In chronic MDE, episodes of inflammation are longer. This tends to result in secretions that have a more solid, cheesy texture, partly due to cholesterol crystals, foam cells, and inflammatory cells. For both types of MDE, the appearance can mimic high-grade ductal carcinoma in situ (DCIS) on US. In this essay, 2 chronic MDE cases are presented and their US appearance discussed. Our goal is to explore

HVAC; Heating, Ventilation, Air Conditioning - Aerosol Duct Sealant

Science.gov (United States)

2016-09-01

material was applied. Annual energy and cost savings were predicted based on a typical weather year for each site. The installation of the duct...Balance reports; Visible dust streaks on duct work, ceilings near supply diffusers, or electrical boxes; Comfort complaints Specific Leakage...energy consumption , depending on the HVAC system type and the location of the ducts that were sealed. The cost effectiveness of the technology is

High-Performance Ducts in Hot-Dry Climates

Energy Technology Data Exchange (ETDEWEB)

Hoeschele, Marc [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Chitwood, Rick [National Renewable Energy Laboratory (NREL), Golden, CO (United States); German, Alea [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Weitzel, Elizabeth [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2015-07-30

Duct thermal losses and air leakage have long been recognized as prime culprits in the degradation of heating, ventilating, and air-conditioning (HVAC) system efficiency. Both the U.S. Department of Energy’s Zero Energy Ready Home program and California’s proposed 2016 Title 24 Residential Energy Efficiency Standards require that ducts be installed within conditioned space or that other measures be taken to provide similar improvements in delivery effectiveness (DE). Pacific Gas & Electric Company commissioned a study to evaluate ducts in conditioned space and high-performance attics (HPAs) in support of the proposed codes and standards enhancements included in California’s 2016 Title 24 Residential Energy Efficiency Standards. The goal was to work with a select group of builders to design and install high-performance duct (HPD) systems, such as ducts in conditioned space (DCS), in one or more of their homes and to obtain test data to verify the improvement in DE compared to standard practice. Davis Energy Group (DEG) helped select the builders and led a team that provided information about HPD strategies to them. DEG also observed the construction process, completed testing, and collected cost data.

Characterization of flow in a scroll duct

Science.gov (United States)

Begg, E. K.; Bennett, J. C.

1985-01-01

A quantitative, flow visualization study was made of a partially elliptic cross section, inward curving duct (scroll duct), with an axial outflow through a vaneless annular cutlet. The working fluid was water, with a Re(d) of 40,000 at the inlet to the scroll duct, this Reynolds number being representative of the conditions in an actual gas turbine scroll. Both still and high speed moving pictures of fluorescein dye injected into the flow and illuminated by an argon ion laser were used to document the flow. Strong secondary flow, similar to the secondary flow in a pipe bend, was found in the bottom half of the scroll within the first 180 degs of turning. The pressure field set up by the turning duct was strong enough to affect the inlet flow condition. At 90 degs downstream, the large scale secondary flow was found to be oscillatory in nature. The exit flow was nonuniform in the annular exit. By 270 degs downstream, the flow appeared unorganized with no distinctive secondary flow pattern. Large scale structures from the upstream core region appeared by 90 degs and continued through the duct to reenter at the inlet section.

Sound radiation contrast in MR phase images. Method for the representation of elasticity, sound damping, and sound impedance changes; Schallstrahlungskontrast in MR-Phasenbildern. Methode zur Darstellung von Elastizitaets-, Schalldaempfungs- und Schallimpedanzaenderungen

Energy Technology Data Exchange (ETDEWEB)

Radicke, Marcus

2009-12-18

The method presented in this thesis combines ultrasound techniques with the magnetic-resonance tomography (MRT). An ultrasonic wave generates in absorbing media a static force in sound-propagation direction. The force leads at sound intensities of some W/cm{sup 2} and a sound frequency in the lower MHz range to a tissue shift in the micrometer range. This tissue shift depends on the sound power, the sound frequency, the sound absorption, and the elastic properties of the tissue. A MRT sequence of the Siemens Healthcare AG was modified so that it measures (indirectly) the tissue shift, codes as grey values, and presents as 2D picture. By means of the grey values the sound-beam slope in the tissue can be visualized, and so additionally sound obstacles (changes of the sound impedance) can be detected. By the MRT images token up spatial changes of the tissue parameters sound absorption and elasticity can be detected. In this thesis measurements are presented, which show the feasibility and future chances of this method especially for the mammary-cancer diagnostics. [German] Die in dieser Arbeit praesentierte Methode kombiniert Ultraschalltechniken mit der Magnetresonanztomographie (MRT). Eine Ultraschallwelle ruft in absorbierenden Medien eine statische Kraft in Schallausbreitungsrichtung hervor. Die Kraft fuehrt bei Schallintensitaeten von einigen W/cm{sup 2} und einer Schallfrequenz im niederen MHz-Bereich zu einer Gewebeverschiebung im Mikrometerbereich. Diese Gewebeverschiebung haengt ab von der Schallleistung, der Schallfrequenz, der Schallabsorption und den elastischen Eigenschaften des Gewebes. Es wurde eine MRT-Sequenz der Siemens Healthcare AG modifiziert, so dass sie (indirekt) die Gewebeverschiebung misst, als Grauwerte kodiert und als 2D-Bild darstellt. Anhand der Grauwerte kann der Schallstrahlverlauf in dem Gewebe visualisiert werden, und so koennen zusaetzlich Schallhindernisse (Aenderungen der Schallkennimpedanz) aufgespuert werden. Mit den

On Computations of Duct Acoustics with Near Cut-Off Frequency

Science.gov (United States)

Dong, Thomas Z.; Povinelli, Louis A.

1997-01-01

The cut-off is a unique feature associated with duct acoustics due to the presence of duct walls. A study of this cut-off effect on the computations of duct acoustics is performed in the present work. The results show that the computation of duct acoustic modes near cut-off requires higher numerical resolutions than others to avoid being numerically cut off. Duct acoustic problems in Category 2 are solved by the DRP finite difference scheme with the selective artificial damping method and results are presented and compared to reference solutions.

Identification and treatment of variation of extrahepatic bile duct in laparoscopic cholecystectomy

Directory of Open Access Journals (Sweden)

PENG Lei

2015-10-01

Full Text Available ObjectiveTo investigate the identification and treatment of variation of extrahepatic bile duct in laparoscopic cholecystectomy (LC, and to reduce the occurrence of bile duct injury. MethodsThis study included 60 patients who received LC in the People′s Hospital of Caidian District in Wuhan and had structural variation of extrahepatic bile duct found during the operation from January 2012 to January 2014. The clinical data were retrospectively analyzed, and the intraoperative and postoperative conditions were summarized. ResultsDuring operation, cystic duct variation was found in 32 cases, abnormal position of the point where the cystic duct joins the extrahepatic bile duct in 20 cases, the cystic duct and the common hepatic duct having the common wall before joining the common bile duct in 2 cases, aberrant bile duct in the gallbladder bed in 2 cases, and accessory hepatic duct in 4 cases. Fifty-one patients (85% successfully underwent LC; 9 patients (15% were converted to open surgery. All patients finished surgery successfully. There were 2 cases of postoperative complications; one patient developed residual stones in the bile duct, and bile leakage occurred in the other patient at one week after LC, who recovered after reoperation. All patients were cured and discharged, without severe complications such as intraperitoneal hemorrhage, infection, and intestinal injury. ConclusionIdentifying the structural variation of extrahepatic bile duct, dissecting the Calot′s triangle meticulously, and determining the type of variation of extrahepatic bile duct play important roles in LC and significantly reduce the incidence of bile duct injury.

Bile duct obstruction

Science.gov (United States)

... Tumors that have spread to the biliary system Liver and bile duct worms (flukes) The risk factors include: History of ... Increased bilirubin level Increased alkaline phosphatase level Increased liver enzymes The ... CT scan Endoscopic retrograde cholangiopancreatography ( ...

Pancreatic-duct-lavage cytology in candidates for surgical resection of branch-duct intraductal papillary mucinous neoplasm of the pancreas: should the International Consensus Guidelines be revised?

Science.gov (United States)

Sai, Jin Kan; Suyama, Masafumi; Kubokawa, Yoshihiro; Watanabe, Sumio; Maehara, Tadayuki

2009-03-01

The International Consensus Guidelines are helpful for the management of branch-duct intraductal papillary mucinous neoplasms (IPMNs), because they allow us to exclude malignancy. However, it is not possible to predict malignancy with certainty, and further preoperative differentiation between benign and malignant IPMNs is required to avoid the false-positive results. To examine the usefulness of pancreatic-duct-lavage cytology by using an originally designed double-lumen catheter for discriminating benign and malignant IPMNs of the branch-duct type in candidates for surgical resection based on the International Consensus Guidelines. Pancreatic-duct-lavage cytology was investigated in 24 patients with branch-duct IPMNs who underwent surgical resection based on the International Consensus Guidelines, namely, they either had intramural nodules or the ectatic branch duct was >30 mm in diameter. Single-center retrospective study. Academic medical center. The sensitivity and specificity of pancreatic-duct-lavage cytology for discriminating benign from malignant IPMNs. More than 30 mL of pancreatic-duct-lavage fluid was obtained from each patient, and there were no patients with noninformative results. The sensitivity, specificity, positive predictive value, and negative predictive value of the cytologic diagnosis were 78%, 93%, 88%, and 88%, respectively. Single-center and small number of patients. Pancreatic-duct-lavage cytology can improve differentiation between benign and malignant IPMNs of the branch-duct type in candidates for surgical resection based on the International Consensus Guidelines.

Determination of the Absorbed Doses in Shanks of Interventional Radiologists

International Nuclear Information System (INIS)

Golnik, N.; Szczepanski, K.; Tulik, P.; Obryk, B.

2008-01-01

Complicated procedures of interventional radiology require usually a much longer investigation time, comparing to the conventional radiography. Moreover, interventional radiology procedures require the presence of the medical staff next to the patient in order to perform the procedure. This results in higher risk for health professionals. Even though these persons reasonably keep away from the primary X ray beam, they are under the effects of scatter radiation due to the interaction of the primary beam with the patient. The protection aprons, thyroid protectors and shielding glasses are used in order to minimize the doses for the staff, but lower parts of legs remain usually unprotected and the absorbed doses in shanks are not recorded. The paper presents the measured values of the absorbed dose in lower extremities of medical staff, involved in the procedures of interventional radiology, completed with the measurements of air kerma under the patient table. Measurements were performed in one of big hospitals in Warsaw during all the procedures performed in six weeks. Majority of the procedures constituted angioplasty or angioplasty with vascular stenting, uterine fibroid embolization and cholangiography. In the angioplasty procedure, imaging techniques are used to guide a balloon-tipped catheter into an artery and advance it to where the vessel is narrow or blocked. The balloon is then inflated to open the vessel, deflated and removed. In vascular stenting, which is often performed with angioplasty, a small wire mesh tube (a stent) is permanently placed in the newly opened artery to help it remain open. In a uterine fibroid embolization procedure, the image guidance is used in order to place an embolic agent (synthetic material) inside one or more of the blood vessels that supply the fibroid tumors with blood. As a result, these vessels become occluded, or closed off, and the fibroid tissue shrinks. Percutaneous transhepatic cholangiography is a way of examining

Percutaneous treatment of benign bile duct strictures

Energy Technology Data Exchange (ETDEWEB)

Koecher, Martin [Department of Radiology, University Hospital, I.P.Pavlova 6, 775 20 Olomouc (Czech Republic)]. E-mail: martin.kocher@seznam.cz; Cerna, Marie [Department of Radiology, University Hospital, I.P.Pavlova 6, 775 20 Olomouc (Czech Republic); Havlik, Roman [Department of Surgery, University Hospital, I.P.Pavlova 6, 775 20 Olomouc (Czech Republic); Kral, Vladimir [Department of Surgery, University Hospital, I.P.Pavlova 6, 775 20 Olomouc (Czech Republic); Gryga, Adolf [Department of Surgery, University Hospital, I.P.Pavlova 6, 775 20 Olomouc (Czech Republic); Duda, Miloslav [Department of Surgery, University Hospital, I.P.Pavlova 6, 775 20 Olomouc (Czech Republic)

2007-05-15

Purpose: To evaluate long-term results of treatment of benign bile duct strictures. Materials and methods: From February 1994 to November 2005, 21 patients (9 men, 12 women) with median age of 50.6 years (range 27-77 years) were indicated to percutaneous treatment of benign bile duct stricture. Stricture of hepatic ducts junction resulting from thermic injury during laparoscopic cholecystectomy was indication for treatment in one patient, stricture of hepaticojejunostomy was indication for treatment in all other patients. Clinical symptoms (obstructive jaundice, anicteric cholestasis, cholangitis or biliary cirrhosis) have appeared from 3 months to 12 years after surgery. Results: Initial internal/external biliary drainage was successful in 20 patients out of 21. These 20 patients after successful initial drainage were treated by balloon dilatation and long-term internal/external drainage. Sixteen patients were symptoms free during the follow-up. The relapse of clinical symptoms has appeared in four patients 9, 12, 14 and 24 months after treatment. One year primary clinical success rate of treatment for benign bile duct stricture was 94%. Additional two patients are symptoms free after redilatation (15 and 45 months). One patient is still in treatment, one patient died during secondary treatment period without interrelation with biliary intervention. The secondary clinical success rate is 100%. Conclusion: Benign bile duct strictures of hepatic ducts junction or biliary-enteric anastomosis are difficult to treat surgically and endoscopically inaccessible. Percutaneous treatment by balloon dilatation and long-term internal/external drainage is feasible in the majority of these patients. It is minimally invasive, safe and effective.

Fluid flow in a spiral microfluidic duct

Science.gov (United States)

Harding, Brendan; Stokes, Yvonne

2018-04-01

We consider the steady, pressure driven flow of a viscous fluid through a microfluidic device having the geometry of a planar spiral duct with a slowly varying curvature and height smaller than width. For this problem, it is convenient to express the Navier-Stokes equations in terms of a non-orthogonal coordinate system. Then, after applying appropriate scalings, the leading order equations admit a relatively simple solution in the central region of the duct cross section. First-order corrections with respect to the duct curvature and aspect ratio parameters are also obtained for this region. Additional correction terms are needed to ensure that no slip and no penetration conditions are satisfied on the side walls. Our solutions allow for a top wall shape that varies with respect to the radial coordinate which allows us to study the flow in a variety of cross-sectional shapes, including trapezoidal-shaped ducts that have been studied experimentally. At leading order, the flow is found to depend on the local height and slope of the top wall within the central region. The solutions are compared with numerical approximations of a classical Dean flow and are found to be in good agreement for a small duct aspect ratio and a slowly varying and small curvature. We conclude that the slowly varying curvature typical of spiral microfluidic devices has a negligible impact on the flow in the sense that locally the flow does not differ significantly from the classical Dean flow through a duct having the same curvature.

The Canadian residential duct and chimney survey

Energy Technology Data Exchange (ETDEWEB)

Fugler, D.

2003-12-01

A study was conducted in 1989 to better understand the thermal performance of ducts and chimneys in houses. The objective was to address the problems associated with insufficient airflow and backdrafting of combustion gases resulting from malfunctioning fans, furnaces and fireplaces. The Duct Test Rig was used to measure and recorded airflows and heat losses in a variety of ducts and chimneys in a representative mix of houses in Vancouver, Kelowna, Winnipeg, Calgary, Toronto, London, Montreal, Quebec City, Halifax, Fredericton and Ottawa. Bath, kitchen, clothes dryer and central vacuum exhaust fans were tested to determine how performance is affected by fan age, accumulations of dust, grease, bugs and installation methods. Results indicate that there is no statistical difference between axial or centrifugal fans. The greatest problem appeared to be with low flows, high leakage rates, and poor conditions of bathroom fans. Many kitchen fans were found to be blocked at the inlet by cooking grease. The exhaust flows depended greatly on the condition of the backdraft damper. Dryer exhaust airflow was typically less than the 75 L/s specified by manufacturers, but even old dryers performed relatively well. All types of chimneys were tested for different positive hood pressures, airflow lost through leakage, and thermal characteristics. Airflow was found to vary depending on the type and area of the flue and the presence of a cap. For heating systems, the low duct efficiency was due mostly to duct leakage, radiation losses and restrictive ducts and registers. The findings of this testing program are still valid today. 3 tabs.

Experiments and calculations on neutron streaming through bent ducts

Energy Technology Data Exchange (ETDEWEB)

Kloosterman, J.L.; Hoogenboom, J.E. (Delft Univ. of Technology (Netherlands). Interfaculty Reactor Inst.); Zsolnay, E.M.

1993-07-01

Neutron spectra in a cylindrical straight duct and in bent ducts with angles of 30deg, 60deg and 90deg have been measured by the multiple foil activation and thermoluminescence dosimetry methods. Two-dimensional discrete ordinates and three-dimensional Monte Carlo calculations are executed, and the results are compared with the measurements. The flow rate at the duct entrance calculated by the DOT3.5 code is underestimated by approximately 30 %, due to a conversion of the core and reflector geometry from XY to RZ geometry. The fast neutron flux in the ducts is underestimated by 20 % by the MORSE-SGC/S code due to a too coarse angular mesh of the source, which does not properly represent the actual angular distribution of the fast flux, which is highly peaked forwardly into the ducts. The thermal neutron flux was over-estimated by the Monte Carlo calculation. A method is proposed to calculate the angular distribution of the flow rate at the duct entrance and to calculate the source strength and the angular distribution of the flow rate at the entrance of the second leg of the duct. The results are compared with those of the transport calculations. Generally, the agreement is quite satisfactory. (author).

Development of a readily recyclable sound insulation material made of polyester fibers. Application of the PET fibers from plastic bottles; Recycle kanona jidoshayo polyester sei kyuon zairyo no kaihatsu. Shiyozumi pet bottle zai no insulator zai eno tekiyo

Energy Technology Data Exchange (ETDEWEB)

Nemoto, K; Watanabe, K; Sugawara, H; Minemura, Y [Nissan Motor Co. Ltd., Tokyo (Japan)

1997-10-01

We have developed new polyester sound-absorbing materials made of fine and modified-cross-section polyester fabric. They provide noticeably higher sound-absorbing performance than traditional materials. Another feature of the new materials is their excellent recyclability since they are made of polyester. Application of the new materials to the dash silencer and the floor carpeting produced a great improvement in sound-insulation performance with less weight. 2 refs., 7 figs.

Pancreaticobiliary duct changes of periampullary carcinomas: Quantitative analysis at MR imaging

Energy Technology Data Exchange (ETDEWEB)

Wu, Dong Sheng, E-mail: victoryhope@163.com [Department of Radiology, West China Hospital of Sichuan University, Chengdu, Sichuan 610041 (China); Department of Radiology, No.4 West China Teaching Hospital of Sichuan University, Chengdu 610041 (China); Chen, Wei Xia, E-mail: wxchen25@126.com [Department of Radiology, West China Hospital of Sichuan University, Chengdu, Sichuan 610041 (China); Wang, Xiao Dong, E-mail: tyfs03yz@163.com [Department of Radiology, West China Hospital of Sichuan University, Chengdu, Sichuan 610041 (China); Acharya, Riwaz, E-mail: riwaz007@hotmail.com [Department of Radiology, West China Hospital of Sichuan University, Chengdu, Sichuan 610041 (China); Jiang, Xing Hua, E-mail: 13881865517@163.com [Department of Pathology, West China Hospital of Sichuan University, Chengdu, Sichuan 610041 (China)

2012-09-15

Purpose: To quantitatively analyse the pancreaticobiliary duct changes of periampullary carcinomas with volumetric interpolated breath-hold examination (VIBE) and true fast imaging with steady-state precession (true FISP) sequence, and investigate the value of these findings in differentiation and preoperative evaluation. Materials and methods: Magnetic resonance (MR) images of 71 cases of periampullary carcinomas (34 cases of pancreatic head carcinoma, 16 cases of intrapancreatic bile duct carcinoma and 21 cases of ampullary carcinoma) confirmed histopathologically were analysed. The maximum diameter of the common bile duct (CBD) and main pancreatic duct (MPD), dilated pancreaticobiliary duct angle and the distance from the end of the proximal dilated pancreaticobiliary duct to the major papilla were measured. Analysis of variance and the Chi-squared test were performed. Results: These findings showed significant differences among the three subtypes: the distance from the end of proximal dilated pancreaticobiliary duct to the major papilla and pancreaticobiliary duct angle. The distance and the pancreaticobiliary duct angle were least for ampullary carcinoma among the three subtypes. The percentage of dilated CBD was 94.1%, 93.8%, and 100% for pancreatic head carcinoma, intrapancreatic bile duct carcinoma and ampullary carcinoma, respectively. And that for the dilated MPD was 58.8%, 43.8%, and 42.9%, respectively. Conclusion: Quantitative analysis of the pancreaticobiliary ductal system can provide accurate and objective assessment of the pancreaticobiliary duct changes. Although benefit in differential diagnosis is limited, these findings are valuable in preoperative evaluation for both radical resection and palliative surgery.

Persistent Mullerian Duct Syndrome (PMDS With Large Intraabdominal Seminoma

Directory of Open Access Journals (Sweden)

Della Harigovind

2017-07-01

Full Text Available Persistent Mullerian Duct Syndrome, a form of male pseudohermaphroditism is characterized by the presence of the Mullerian duct derivatives in an otherwise phenotypically as well as genotypically normal male. We report a case of large intra abdominal seminoma in a male patient with cryptorchidism, along with persistence of Mullerian duct derivatives (uterus.

Parotid duct laceration repair in two horses : case report

Directory of Open Access Journals (Sweden)

A. Olivier

1998-07-01

Full Text Available Repair of parotid duct lacerations in 2 horses is described using intraluminal silastic tubing as a stent. The duct was lacerated traumatically at the facial vessel notch (incisura vasorum facialium in the 1st horse, and iatrogenically after removal of an intraluminal sialolith after development of infection within the duct in the 2nd horse. In both cases, a silastic tube was passed retrograde into the duct via the salivary papilla, past the wound until the end lay rostroventral to the parotid salivary gland. The severed salivary ducts and the wounds were sutured. The external portion of the silastic tube was sutured to the skin and the tube left in place. Recovery in the 1st case was uneventful. In the 2nd case a salivary duct/cutaneous fistula formed at a wound distant from the sutured wound, which healed spontaneously. This technique differs from a similar described technique in that the stent tube exits the oral cavity and is attached to the outer skin surface.

Liver and Bile Duct Cancer—Patient Version

Science.gov (United States)

Liver cancer includes hepatocellular carcinoma and bile duct cancer (cholangiocarcinoma). Risk factors for HCC include chronic infection with hepatitis B or C and cirrhosis of the liver. Start here to find information on liver and bile duct cancer treatment, causes and prevention, screening, research, and statistics.

Submandibular duct sialolithiasis an unusual presentation

International Nuclear Information System (INIS)

Shafi, M.; Jafferi, S.; Jafferi, S.

2006-01-01

Multiple calculi in a submandibular gland duct is an uncommon occurrence. One such case occurring in a young boy of 25 years is reported here where thirteen very small stones of 1-3 mm of maximum diameter were lined up in the Wharton's duct in such a way that they were difficult to appreciate on inspection and palpation. Successful exploration was done in two steps. (author)

Measure Guideline: Summary of Interior Ducts in New Construction, Including an Efficient, Affordable Method to Install Fur-Down Interior Ducts

Energy Technology Data Exchange (ETDEWEB)

Beal, D. [BA-PIRC, Cocoa, FL (United States); McIlvaine, J. [BA-PIRC, Cocoa, FL (United States); Fonorow, K. [BA-PIRC, Cocoa, FL (United States); Martin, E. [BA-PIRC, Cocoa, FL (United States)

2011-11-01

This document illustrates guidelines for the efficient installation of interior duct systems in new housing, including the fur-up chase method, the fur-down chase method, and interior ducts positioned in sealed attics or sealed crawl spaces.

Evaluation of PEGIT duct connection system

Energy Technology Data Exchange (ETDEWEB)

Walker, Iain S.; Brenner, Douglas E.; Sherman, Max H.; Dickerhoff, Darryl J.

2003-08-01

Most air duct system components are assembled in the field and are mechanically fastened by sheet metal screws (for sheet metal-to-sheet metal) or by drawbands (for flex duct-to-sheet metal). Air sealing is separate from this mechanical fastening and is usually achieved using tape or mastic products after mechanical fastening. Field observations have shown that mechanical fastening rarely meets code or manufacturers requirements and that sealing procedures are similarly inconsistent. To address these problems, Proctor Engineering Group (PEG) is developing a system of joining ducts (called PEGIT) that combines the mechanical fastening and sealing into a single self-contained procedure. The PEGIT system uses a shaped flexible seal between specially designed sheet metal duct fittings to both seal and fasten duct sections together. Figure 1 shows the inner duct fitting complete with rubber seal. This seal provides the air seal for the completed fitting and is shaped to allow the inner and outer fittings to slide together, and then to lock the fittings in place. The illustration in Figure 2 shows the approximate cross section of the rubber seal that shows how the seal has a lip that is angled backwards. This angled lip allows the joint to be pushed together by folding flat but then its long axis makes it stiff in the pulling apart direction. This study was undertaken to assist PEG in some of the design aspects of this system and to test the performance of the PEGIT system. This study was carried out in three phases. The initial phase evaluated the performance of a preliminary seal design for the PEGIT system. After the first phase, the seal was redesigned and this new seal was evaluated in the second phase of testing. The third phase performed more detailed testing of the second seal design to optimize the production tolerances of the sheet metal fittings. This report summarizes our findings from the first two phases and provides details about the third phase of testing.

Measure Guideline: Sealing and Insulating of Ducts in Existing Homes

Energy Technology Data Exchange (ETDEWEB)

Aldrich, R.; Puttagunta, S.

2011-12-01

This document begins with a discussion on potential cost and performance benefits of duct sealing and insulating. It continues with a review of typical duct materials and components and the overall procedures for assessing and improving the duct system.

Squamous metaplasia of lactiferous ducts (SMOLD)

International Nuclear Information System (INIS)

Lo, G.; Dessauvagie, B.; Sterrett, G.; Bourke, A.G.

2012-01-01

The aim of this review is to illustrate the mammographic and sonographic appearances of squamous metaplasia of the lactiferous ducts (SMOLD) and to discuss the disease processes of this uncommon breast disease, which shows a strong correlation with smoking. The most common mammographic appearance is of a retro-areolar asymmetrical density. Ultrasonography of the symptomatic breast typically shows a retro-areolar, predominately medial, ill-defined, hypoechoic lesion with either abscess or sinus/fistula formation. Duct dilatation and continuity with lactiferous ducts is commonly seen. Increased vascularity is occasionally seen on colour Doppler ultrasound. Pathology tissue confirmation is always required and this can be by histology of a core biopsy or excision specimen, or fine-needle aspiration (FNA) cytology. Occasionally smears of an associated abundant nipple or sinus discharge may be of value.

Ducted wind turbine optimization : A numerical approach

NARCIS (Netherlands)

Dighe, V.V.; De Oliveira Andrade, G.L.; van Bussel, G.J.W.

2017-01-01

The practice of ducting wind turbines has shown a beneficial effect on the overall performance, when compared to an open turbine of the same rotor diameter1. However, an optimization study specifically for ducted wind turbines (DWT’s) is missing or incomplete. This work focuses on a numerical

Common bile duct cancer with massive necrosis mimicking choledochal dilatation on CT

International Nuclear Information System (INIS)

Miyake, H.; Matsumoto, S.; Ueda, S.; Maeda, T.; Aikawa, H.; Mori, H.

1991-01-01

Carcinomas of the common bile duct are usually seen as dilatation of the bile duct proximal to a solid mass on CT. In the case reported here, the common bile duct cancer itself mimicked dilated common bile duct on CT because of massive necrosis. In a case of simulating dilated common bile duct on CT, and discrepancy between CT and ultrasonography or endoscopic retrograde cholangiopancreatography, a common bile duct cancer with massive necrosis should be included in the differential diagnosis. (orig.)

Entropy generation and thermodynamic analysis of solar air heaters with artificial roughness on absorber plate

Directory of Open Access Journals (Sweden)

Prasad Radha K.

2017-09-01

Full Text Available This paper presents mathematical modelling and numerical analysis to evaluate entropy generation analysis (EGA by considering pressure drop and second law efficiency based on thermodynamics for forced convection heat transfer in rectangular duct of a solar air heater with wire as artificial roughness in the form of arc shape geometry on the absorber plate. The investigation includes evaluations of entropy generation, entropy generation number, Bejan number and irreversibilities of roughened as well as smooth absorber plate solar air heaters to compare the relative performances. Furthermore, effects of various roughness parameters and operating parameters on entropy generation have also been investigated. Entropy generation and irreversibilities (exergy destroyed has its minimum value at relative roughness height of 0.0422 and relative angle of attack of 0.33, which leads to the maximum exergetic efficiency. Entropy generation and exergy based analyses can be adopted for the evaluation of the overall performance of solar air heaters.

Hollow-duct radiation delivery system investigation

Directory of Open Access Journals (Sweden)

Kramer D.

2013-05-01

Full Text Available Investigation of hollow-duct structure for high-power laser-diode-array radiation delivery into the end-pumped large-aperture gain media is reported. A ray tracing method has been used to evaluate the performance of the structure designed for maximum transmission efficiency and output beam profile homogeneity. Variable hollow-duct lengths as well as emanating angles of laser-diode-array have been taken into account.

Prediction of fan assisted flow in a duct/pipe network

International Nuclear Information System (INIS)

Quraishi, M.S.

1996-01-01

The commonly used fan+duct model is usually based on a table generated by matching the fan and system characteristic curves with the applied pressure drop across the fan+duct/pipe network and using linear or polynomial interpolation for intermediate values. However, this empirical approach can only handle a single system configuration for each table. If this approach is replaced by an algebraic formulation a general and flexible model can be developed. The algebraic model will be able to account for failure of resistances in the duct/pipe system as well as the failure of duct/pipe at an intermediate location. This paper presents the development of an algebraic model for fan+duct/pipe systems. (author)

An incidence study on thyroglossal duct cysts in adults

International Nuclear Information System (INIS)

Kurt, A.; Ortug, C.; Aydar, Y.; Ortug, G.

2007-01-01

To investigate the incidence of the asymptomatic thyroglossal duct anomalies and to review the literature and make comments on the significance of this condition. A total of 80 cadavers were dissected in the present study. This study was carried out during 2005, where the cadavers were randomly included from the criminal laboratories of the Ministry of Justice, Republic of Turkey in Istanbul. None of the cadavers had laryngeal and cervical injuries resulting from a trauma or the cause of their death. The examined cadavers included 59 men and 21 females, and their ages were ranged from 35-80 years old. The larynges were removed and fixed in 10% formalin and then dissected. The sections were examined using surgical SMZ 10 Nikon stereomicroscope. We evaluated the presence, localization and diameter of the cysts with regard to age and sex of the cadavers. We observed a total of 12 different localization of thyroglossal ducts and cysts among the 80 dissected cadavers. Ten of these ducts cysts were found in males with an age range of 35-68 years and 2 female cadavers aged 45-65 years. In 6 cases, the thyroglossal ducts and cysts were located in the left of the midline of the neck, while 3 cases were from the right of the midline, and the remaining was located on the midline of the neck. In all cases, thryoglossal ducts and cysts were complete and restricted to the infrahyoid region: all of them had connection with the hyoid bone, but not with the perichondrium of the cartilage. In addition, the thyroglossal ducts have connection with the left lobe of the thyroid glands in 3 cases, one case in the right lobe, and 2 cases with the isthmus of the thyroid gland. Finally in 5 cases thyroglossal ducts were complete and had well developed cysts. Thyroglossal duct remnants are one of the most often seen congenital asymptomatic masses of the neck region (7%). The presence of these duct remnants may lead to abnormal phonation and epithelial carcinomas. Therefore, correlation of

Endoscopic stenting in bile duct cancer increases liver volume.

Science.gov (United States)

Lee, Chang Hun; Kim, Seong Hun; Kim, In Hee; Kim, Sang Wook; Lee, Soo Teik; Kim, Dae Ghon; Yang, Jae Do; Yu, Hee Chul; Cho, Baik Hwan; Lee, Seung Ok

2014-09-01

Objective evaluation tools for assessing the effectiveness of stenting in palliative treatment of malignant biliary obstruction are not satisfactory. Effects of biliary stenting on liver volume change have never been studied. We aimed to use volumetry to analyze liver volume changes after endoscopic stenting in bile duct cancer according to the location and number of stents. Retrospective review. University hospital. Patients with a diagnosis of hilar or distal bile duct cancer and who underwent biliary metal stenting. ERCP with self-expandable metal stent placement. Liver volume change after biliary stenting and its comparison according to the location (hilar vs distal common bile duct) and number (hilar bilateral vs hilar unilateral). There were 60 patients; 31 were treated for hilar bile duct cancer (13 for bilateral stent and 18 for unilateral stent) and 29 for distal bile duct cancer. Overall mean follow-up duration was 11.7 ± 4.9 weeks. Liver volume increased 17.4 ± 24.1%. The rate of liver growth was rapid during the early period from 4 to 8 weeks. Stenting in hilar bile duct cancer tended to increase liver volume more than distal biliary stents (22.5% vs 11.9%, P = .091). In hilar bile duct cancer, unilateral and bilateral stents showed similar liver volume increases (20.1% and 25.8%, respectively; P = .512). Single center, retrospective. Biliary stenting markedly increased liver volume in both hilar and distal bile duct cancer. Our data suggest that liver volume assessment could be a useful tool for evaluating stent efficacy. Copyright © 2014 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.

Reconstruction of Bile Duct Injury and Defect with the Round Ligament.

Science.gov (United States)

Dokmak, Safi; Aussilhou, Béatrice; Ragot, Emilia; Tantardini, Camille; Cauchy, François; Ponsot, Philippe; Belghiti, Jacques; Sauvanet, Alain; Soubrane, Olivier

2017-09-01

Lateral injury of the bile duct can occur after cholecystectomy, bile duct dissection, or exploration. If direct repair is not possible, conversion to bilioenteric anastomosis can be needed with the risk of long-term bile duct infections and associated complications. We developed a new surgical technique which consist of reconstructing the bile duct with the round ligament. The vascularized round ligament is completely mobilized until its origin and used for lateral reconstruction of the bile duct to cover the defect. T tube was inserted and removed after few months. Patency of the bile duct was assessed by cholangiography, the liver function test and magnetic resonance imaging (MRI). Two patients aged 33 and 59 years old underwent lateral reconstruction of the bile duct for defects secondary to choledocotomy for stone extraction or during dissection for Mirizzi syndrome. The defects measured 2 and 3 cm and occupied half of the bile duct circumference. The postoperative course was marked by low output biliary fistula resolved spontaneously. In one patient, the T tube was removed at 3 months after surgery and MRI at 9 months showed strictly normal aspect of the bile duct with normal liver function test. The second patient is going very well 2 months after surgery and the T tube is closed. Lateral reconstruction of the bile duct can be safely achieved with the vascularized round ligament. We will extend our indications to tubular reconstruction.

Anatomic variations in intrahepatic bile ducts in a north Indian population.

Science.gov (United States)

Sharma, Vijay; Saraswat, Vivek Anand; Baijal, Sanjay Saran; Choudhuri, Gourdas

2008-07-01

In the present study, we described the anatomical variations in the branching patterns of intrahepatic bile ducts (IHD) and determined the frequency of each variation in north Indian patients. There are no data from India. The study group consisted of 253 consecutive patients (131 women) undergoing endoscopic retrograde cholangiograms for different indications. Anatomical variations in IHD were classified according to the branching pattern of the right anterior segmental duct (RASD) and the right posterior segmental duct (RPSD), presence or absence of first-order branch of left hepatic duct (LHD) and of an accessory hepatic duct. Anatomy of the IHD was typical in 52.9% of cases (n = 134), showing triple confluence in 11.46% (n = 29), anomalous drainage of the RPSD into the LHD in 18.2% (n = 46), anomalous drainage of the RPSD into the common hepatic duct (CHD) in 7.1% (n = 18), drainage of the right hepatic duct (RHD) into the cystic duct 0.4% (n = 1), presence of an accessory duct leading to the CHD or RHD in 4.7% (n = 12), individual drainage of the LHD into the RHD or CHD in 2.4% (n = 6), and unclassified or complex variations in 2.7% (n = 7). None had anomalous drainage of RPSD into the cystic duct. The branching pattern of IHD was atypical in 47% patients. The two most common variations were drainage of the RPSD into the LHD (18.2%) and triple confluence of the RASD, RPSD, and LHD (11.5%).

Research on Duct Flow Field Optimisation of a Robot Vacuum Cleaner

Directory of Open Access Journals (Sweden)

Xiao-bo Lai

2011-11-01

Full Text Available The duct of a robot vacuum cleaner is the length of the flow channel between the inlet of the rolling brush blower and the outlet of the vacuum blower. To cope with the pressure drop problem of the duct flow field in a robot vacuum cleaner, a method based on Pressure Implicit with Splitting of Operators (PRISO algorithm is introduced and the optimisation design of the duct flow field is implemented. Firstly, the duct structure in a robot vacuum cleaner is taken as a research object, with the computational fluid dynamics (CFD theories adopted; a three-dimensional fluid model of the duct is established by means of the FLUENT solver of the CFD software. Secondly, with the k-∊ turbulence model of three-dimensional incompressible fluid considered and the PRISO pressure modification algorithm employed, the flow field numerical simulations inside the duct of the robot vacuum cleaner are carried out. Then, the velocity vector plots on the arbitrary plane of the duct flow field are obtained. Finally, an investigation of the dynamic characteristics of the duct flow field is done and defects of the original duct flow field are analysed, the optimisation of the original flow field has then been conducted. Experimental results show that the duct flow field after optimisation can effectively reduce pressure drop, the feasibility as well as the correctness of the theoretical modelling and optimisation approaches are validated.

Research on Duct Flow Field Optimisation of a Robot Vacuum Cleaner

Directory of Open Access Journals (Sweden)

Xiao-bo Lai

2011-11-01

Full Text Available The duct of a robot vacuum cleaner is the length of the flow channel between the inlet of the rolling brush blower and the outlet of the vacuum blower. To cope with the pressure drop problem of the duct flow field in a robot vacuum cleaner, a method based on Pressure Implicit with Splitting of Operators (PRISO algorithm is introduced and the optimisation design of the duct flow field is implemented. Firstly, the duct structure in a robot vacuum cleaner is taken as a research object, with the computational fluid dynamics (CFD theories adopted; a three‐dimensional fluid model of the duct is established by means of the FLUENT solver of the CFD software. Secondly, with the k‐ε turbulence model of three‐ dimensional incompressible fluid considered and the PRISO pressure modification algorithm employed, the flow field numerical simulations inside the duct of the robot vacuum cleaner are carried out. Then, the velocity vector plots on the arbitrary plane of the duct flow field are obtained. Finally, an investigation of the dynamic characteristics of the duct flow field is done and defects of the original duct flow field are analysed, the optimisation of the original flow field has then been conducted. Experimental results show that the duct flow field after optimisation can effectively reduce pressure drop, the feasibility as well as the correctness of the theoretical modelling and optimisation approaches are validated.

Congenital double bile duct presenting as recurrent cholangitis in a child

Directory of Open Access Journals (Sweden)

K.D. Chakravarty

2015-12-01

Full Text Available Double common bile duct (DCBD is a rare congenital anomaly. Most of these bile duct anomalies are associated with bile duct stones, anomalous pancreaticobiliary junction (APBJ, pancreatitis and bile duct or gastric cancers. Early detection and treatment is important to avoid long term complications. Surgical resection of the anomalous bile duct and reconstruction of the biliary enteric anastomosis is the treatment of choice. We report a rare case of DCBD anomaly in a girl, who presented with recurrent cholangitis. She had type Va DCBD anomaly. She underwent successful resection of the bile duct and reconstruction of the biliary enteric anastomosis. Preoperative imaging and diagnosis of the congenital biliary anomaly is very important to avoid intraoperative bile duct injury. Review of the literature shows very few cases of type Va DCBD, presenting with either bile duct stones or APBJ.

Anatomic relationship of intrahepatic bile ducts to portal veins revisited

International Nuclear Information System (INIS)

Bret, P.M.; Stempel, J.; Atri, M.; Lough, J.O.; Illescas, F.F.

1987-01-01

It is well accepted that intrahepatic bile ducts lie in front of corresponding portal vein branches. Since the authors' clinical experience with US was different, they studied 18 normal necropsy cadaver livers. The common bile duct, main portal vein, and hepatic artery were cannulated and injected respectively with air, dilute contrast medium, and mineral oil. The livers were then examined in anatomic position with CT. In the left lobe of the liver, the bile ducts were anterior to the portal vein in seven cases, posterior in seven cases, and were tortuous both anterior and posterior in three cases. In the right lobe, the bile ducts were anterior in nine cases, posterior in five cases, tortuous in one case, and not seen in two cases. In the porta hepatis, the bile ducts were anterior in eight cases, posterior in one case, tortuous in five cases, and not seen in three cases. Histologic specimens confirmed the anterior and posterior location of the bile ducts relative to the portal veins. In conclusion, intrahepatic bile ducts can be either anterior or posterior to the corresponding portal vein branches

Are Ducted Mini-Splits Worth It?

Energy Technology Data Exchange (ETDEWEB)

Winkler, Jonathan M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Maguire, Jeffrey B [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Metzger, Cheryn E. [Pacific Northwest National Laboratory; Zhang, Jason [Pacific Northwest National Laboratory

2018-02-01

Ducted mini-split heat pumps are gaining popularity in some regions of the country due to their energy-efficient specifications and their ability to be hidden from sight. Although product and install costs are typically higher than the ductless mini-split heat pumps, this technology is well worth the premium for some homeowners who do not like to see an indoor unit in their living area. Due to the interest in this technology by local utilities and homeowners, the Bonneville Power Administration (BPA) has funded the Pacific Northwest National Laboratory (PNNL) and the National Renewable Energy Laboratory (NREL) to develop capabilities within the Building Energy Optimization (BEopt) tool to model ducted mini-split heat pumps. After the fundamental capabilities were added, energy-use results could be compared to other technologies that were already in BEopt, such as zonal electric resistance heat, central air source heat pumps, and ductless mini-split heat pumps. Each of these technologies was then compared using five prototype configurations in three different BPA heating zones to determine how the ducted mini-split technology would perform under different scenarios. The result of this project was a set of EnergyPlus models representing the various prototype configurations in each climate zone. Overall, the ducted mini-split heat pumps saved about 33-60% compared to zonal electric resistance heat (with window AC systems modeled in the summer). The results also showed that the ducted mini-split systems used about 4% more energy than the ductless mini-split systems, which saved about 37-64% compared to electric zonal heat (depending on the prototype and climate).

CT findings of thyroglossal duct cyst

International Nuclear Information System (INIS)

Kim, Dong Oh; Kim, Hong Soo; So, Hyun Soon; Nam, Mee Young; Choi, Jae Ho; Rhee, Hak Song

1995-01-01

The purpose of this study was to evaluate the CT findings of thyroglossal duct cysts. Sixteen patients with pathologically proved thyroglossal duct cysts were included in the study. CT scans were assessed retrospectively for shape, size, location, density of the central portions, septations, rim enhancement, changes in the adjacent fascial planes and investment within the strap muscles in the infrahyoid cysts. Thirteen cases of thyroglossal duct cysts were seen as round or oval cystic masses, two cases of them were seen as irregular-shaped lobulated cystic masses, and one case was seen as ovoid soft tissue mass. The cysts were from 1.4 to 5.7 cm in diameter (mean, 2.6 cm). The cyst was infrahyoid in 15 cases and suprahyoid in one case. The cyst was located in midline in eight cases, off midline in four cases, and both midline and off midline in four cases. The density of the central portions ranged from 15 to 82HU (mean, 32HU). Septations were noted in four cases. Rim enhancement was seen in 14 cases (93%), and heterogeneously enhancing soft tissue mass was seen in one case. In four cases, abnormal fascial planes were observed. All but one of the infrahyoid cysts (14/15) were embedded within the strap muscles, and one case of them was located anteriorly to strap muscles. CT permits one to make the diagnosis a thyroglossal duct cyst with a high degree of accuracy, as it can differentiate thyroglossal duct cysts from the other anterior neck masses by their typical location, characteristic morphology, and investment within the strap muscles

Velocity profiles of acoustic streaming in resulting stokes layer by acoustic standing wave in a duct; Kannai kichi shindo ni okeru stokes sonai onkyoryu ryusoku bunpu no kaiseki

Energy Technology Data Exchange (ETDEWEB)

Arakawa, M; Kawahashi, M [Saitama University, Saitama (Japan). Faculty of Engineering

1995-07-25

Acoustic streaming is generated by Reynolds stress in the sense of mean acoustic momentum flux in a sound field. In the case of an acoustic standing wave produced by an air column oscillation in a closed duct, the friction and the Reynolds stress in the resulting Stokes layer are the essentials of acoustic streaming generation in the vicinity of the duct wall. The thickness of the Stokes layer decreases with the oscillatory Reynolds number. The plane wave propagation in the duct is assumed for the case of high Reynolds number except for the thin Stokes layer adjacent to the duct wall. The velocity profiles of the streaming are estimated theoretically from the steady component of the second-order term of a perturbation expansion in which the first-order approximation is a sinusoidal oscillation of the air column with plane waves. The present paper describes theoretical analysis of the velocity profiles of the acoustic streaming in the Stokes layer by means of the matched asymptotic expansion method. The results obtained show the existence of reverse streaming in a very thin layer adjacent to the wall and the effects of thermal boundary conditions at the wall on the velocity profiles of acoustic streaming in the Stokes layer. 9 refs., 8 figs.

Liver and Bile Duct Cancer—Health Professional Version

Science.gov (United States)

Liver cancer includes two major types: hepatocellular carcinoma (HCC) and intrahepatic bile duct cancer, also known as cholangiocarcinoma. Find evidence-based information on liver and bile duct cancer treatment, causes and prevention, screening, research, genomics and statistics.

Laparoscopic Longitudinal Pancreaticojejunostomy Using Barbed Sutures: an Efficient and Secure Solution for Pancreatic Duct Obstructions in Patients with Chronic Pancreatitis.

Science.gov (United States)

Kim, Eun Young; Hong, Tae Ho

2016-04-01

We describe our laparoscopic longitudinal pancreaticojejunostomy (LPJ) technique using barbed sutures to manage a pancreatic duct obstruction. We performed laparoscopic longitudinal anterior pancreaticojejunostomy using barbed sutures (3-0 absorbable wound closure device, V-Loc, Covidien, Minneapolis, MN, USA) in 11 patients who presented with signs of a pancreas ductal obstruction and chronic pancreatitis. The surgical outcomes and follow-up records at the outpatient department were reviewed, and the effectiveness and feasibility of this method were analyzed. Mean patient age was 54.4 ± 9.5 years, and pancreatic duct stones were removed from all patients without conversion to laparotomy. Overall operative time was 200.7 ± 56.4 min, and estimated blood loss was 42.2 ± 11.2 ml. No pancreatic anastomosis leakage or postoperative bleeding was detected. Mean length of hospital stay was 6.5 ± 0.8 days, and mean time to start a soft diet was 4.8 ± 0.7 days. No patient complained of postoperative abdominal pain, and all patients recovered without significant complications or relapse of pancreatitis. The follow-up period was 4-21 months. Our new laparoscopic longitudinal anterior pancreaticojejunostomy technique (Puestow procedure) using barbed sutures is a potentially efficient and minimally invasive procedure for patients who suffer from pancreatic duct obstruction and chronic pancreatitis.

MythBusters, Musicians, and MP3 Players: A Middle School Sound Study

Science.gov (United States)

Putney, Ann

2011-01-01

Create your own speakers for an MP3 player while exploring the science of sound. Review of science notebooks, students' intriguing cabinet designs, and listening to students talk with a musician about the physics of an instrument show that complex concepts are being absorbed and extended with each new iteration. Science that matters to students…

Time course of collagen peak in bile duct-ligated rats

OpenAIRE

Tarcin, Orhan; Basaranoglu, Metin; Tahan, Veysel; Tahan, Gülgün; Sücüllü, Ilker; Yilmaz, Nevin; Sood, Gagan; Snyder, Ned; Hilman, Gilbert; Celikel, Cigdem; Tözün, Nurdan

2011-01-01

Abstract Background One of the most useful experimental fibrogenesis models is the "bile duct-ligated rats". Our aim was to investigate the quantitative hepatic collagen content by two different methods during the different stages of hepatic fibrosis in bile duct-ligated rats on a weekly basis. We questioned whether the 1-wk or 4-wk bile duct-ligated model is suitable in animal fibrogenesis trials. Methods Of the 53 male Wistar rats, 8 (Group 0) were used as a healthy control group. Bile duct...

Internal radiotherapy for hilar bile duct cancer

International Nuclear Information System (INIS)

Ryu, Munemasa; Ogino, Takashi; Konishi, Hiroshi

1999-01-01

By December 1998, 24 patients with non-resected hilar bile duct cancer (mean age of 74) had received bile duct intracavitary irradiation and 13 patients with residual cancer after resection of hilar bile duct cancer had received postoperative intracavitary irradiation. After they were externally irradiated 30 Gy in total by 15 fractions (2 Gy/time, 5 times in a week), intracavitary irradiation using 192-Ir was given 5 times in total (2 times in a week) from 3 weeks after external irradiation under the condition which dose became 8 Gy in depth of 10 mm from radiation source. The cases of postoperative irradiation had 3 times in total. As for 20 patients of non-resected hilar bile duct cancer without metastasis, 50% survival time was 265 days and there was no 5 year survivor. Fifty percents survival time of 4 patients with metastasis was 113 days. The effect of local control was recognized in 20 patients (83.3%). In 13 patients of postoperative irradiation, 50% survival time was 554 days, and survival rate of 3 years was 28%. (K.H.)

Flow characteristics of developing laminar steady flows in a straight duct connected to a square curved duct

Energy Technology Data Exchange (ETDEWEB)

Sohn, Hyun Chull [Chosun Univ., Gwangju (Korea, Republic of)

2005-05-01

In the present study, the characteristics of developing steady laminar flows of a straight duct connected to a 180 .deg. curved duct were examined in the entrance region through experimental measurement. Flow characteristics such as shear stress distributions, pressure distributions and friction coefficient experimentally in a square cross-sectional straight duct by using the PIV system. For the PIV measurement by particles produced from mosquito coils particles. The experimental data were obtained at 9 points dividing the test sections by 400 mm. Experimental results can be summarized as follows. Critical Reynolds number, Re{sub cr} which indicates transition from laminar steady flow to transition steady flow was 2,150. Shear stress per unit length on the wall was stronger than that in the fully developed flow region. This was attributed to the fact that shear stress and pressure loss in the curvature of a duct were increased. Pressure distributions were gradually decreased irrespective of Reynolds number in the whole test section. This trends were in a good agreement with the reference results. Pipe friction coefficient in the steady state flow region was calculate from method of least squares. The co-relationship between fiction coefficient and Reynolds number was established as follow; {lambda}=56/Re.

A remote joint system for large vacuum ducts

International Nuclear Information System (INIS)

Hagmann, D.B.; Coughlan, J.B.

1983-01-01

A large remote vacuum duct joining system has been developed for fusion machines that uses several two-jaw screwdriven clamps. The preferred location for clamp installation is inside the vacuum duct where access space is available for the actuating device. It also decreases space needed for handling operations exterior to the duct. The clamp system is unique in that it is low cost, applies force directly over the seal, permits leak testing to the seal annulus, is highly reliable, can be remotely replaced, and is usable on a variety of other applications

Preparation and Sound Absorption Properties of a Barium Titanate/Nitrile Butadiene Rubber–Polyurethane Foam Composite with Multilayered Structure

Science.gov (United States)

Jiang, Xueliang; Yang, Zhen; Wang, Zhijie; Zhang, Fuqing; You, Feng

2018-01-01

Barium titanate/nitrile butadiene rubber (BT/NBR) and polyurethane (PU) foam were combined to prepare a sound-absorbing material with an alternating multilayered structure. The effects of the cell size of PU foam and the alternating unit number on the sound absorption property of the material were investigated. The results show that the sound absorption efficiency at a low frequency increased when decreasing the cell size of PU foam layer. With the increasing of the alternating unit number, the material shows the sound absorption effect in a wider bandwidth of frequency. The BT/NBR-PU foam composites with alternating multilayered structure have an excellent sound absorption property at low frequency due to the organic combination of airflow resistivity, resonance absorption, and interface dissipation. PMID:29565321

Preparation and Sound Absorption Properties of a Barium Titanate/Nitrile Butadiene Rubber–Polyurethane Foam Composite with Multilayered Structure

Directory of Open Access Journals (Sweden)

Xueliang Jiang

2018-03-01

Full Text Available Barium titanate/nitrile butadiene rubber (BT/NBR and polyurethane (PU foam were combined to prepare a sound-absorbing material with an alternating multilayered structure. The effects of the cell size of PU foam and the alternating unit number on the sound absorption property of the material were investigated. The results show that the sound absorption efficiency at a low frequency increased when decreasing the cell size of PU foam layer. With the increasing of the alternating unit number, the material shows the sound absorption effect in a wider bandwidth of frequency. The BT/NBR-PU foam composites with alternating multilayered structure have an excellent sound absorption property at low frequency due to the organic combination of airflow resistivity, resonance absorption, and interface dissipation.

Preparation and Sound Absorption Properties of a Barium Titanate/Nitrile Butadiene Rubber-Polyurethane Foam Composite with Multilayered Structure.

Science.gov (United States)

Jiang, Xueliang; Yang, Zhen; Wang, Zhijie; Zhang, Fuqing; You, Feng; Yao, Chu

2018-03-22

Barium titanate/nitrile butadiene rubber (BT/NBR) and polyurethane (PU) foam were combined to prepare a sound-absorbing material with an alternating multilayered structure. The effects of the cell size of PU foam and the alternating unit number on the sound absorption property of the material were investigated. The results show that the sound absorption efficiency at a low frequency increased when decreasing the cell size of PU foam layer. With the increasing of the alternating unit number, the material shows the sound absorption effect in a wider bandwidth of frequency. The BT/NBR-PU foam composites with alternating multilayered structure have an excellent sound absorption property at low frequency due to the organic combination of airflow resistivity, resonance absorption, and interface dissipation.

[Salivary gland drainage into the thyroglossal duct].

Science.gov (United States)

Siem, G; Natvig, K; Kolbenstvedt, A; Lømo, J

2001-01-20

Failure in regression of the thyroglossal duct is one of the most common reasons for midline swellings in the neck. Several authors have described recurrent thyroglossal duct remnants with persisting draining sinuses. However, few have described accessory salivary glands that drain into the thyroglossal duct. In this article we report two such cases with midline salivary glands in the floor of the mouth. These two patients were subsequently successfully treated with radical tissue resection in the area between the hyoid bone and foramen cecum. Preoperative fistulography or sinography was useful to demonstrate the ductal ramification of the salivary glands, and use of methylene blue during surgery proved of significant value for the result.

Visualization of the thoracic duct by lymphoscintigraphy

International Nuclear Information System (INIS)

Baulieu, F.; Baulieu, J.L.; Itti, R.; Tours Univ., 37

1987-01-01

Imaging of the thoracic duct is usually performed by radiological lymphography. However, this procedure, which uses an oil based dye injected directly into the lymph channels, has some adverse effects. In this paper we note that lymphoscintigraphy, a physiological and non invasive method, may visualize thoracic duct abnormalities, and might be particularly usefull when radiological lymphography is contraindicated. (orig.)

The experimental study of radiation injury on bile duct and liver tissue

International Nuclear Information System (INIS)

Cao Guiwen; Wang Bin; Sun Yequan; Shao Xueye; Ning Houfa; Sui Shouguang; Wang Xiuchun; Bai Xuming

2007-01-01

Objective: To investigate the safety, acceptance and the effective extent of 192 Ir-internal irradiation, providing theoretical guidelines for HC. Methods: Sixteen male healthy hybrid dogs enrolled in the experiment were divided into 4 groups of 4 each. The brachytherapy applicator was introduced from gall bladder into the convergence of cystic duct with common hepatic duct during the operation and a small chip of 1 cm 3 liver tissue was cut off and taken for control later on. The animals in group A-D were irradiated by 192 Ir-internal irradiation with 30 Gy, 40 Gy, 50 Gy arid 60 Gy at the correlative dose points respectively. Animals were put to death after 10 days subsequently, with sampling specimens obtained from radiation cystic duct and the in between liver tissue with the distant cystic duct. The radiation injury of the cystic duct and liver tissue near bile ducts were observed and studied by light microscope and transmission election microscope. Results: By the limit of the safest endurance dose(50 Gy) of Bile duct, unreversed injury of the nuclei of liver cells occurred at 0 to 15 mm from bile duct revealed by transmission electron microscope and light microscope. The whole biliary duct wall would be undergone necrosis with irradiation dose over 60 Gy. Conclusions: Normal bile duct possesses good endurance to 192 Ir-internal irradiation. Within the safest endurance limit of 50 Gy the effective irradiation field could reach 15 mm from the involved bile duct. (authors)

Iatrogenic injury of an aberrant right posterior sectoral bile duct

African Journals Online (AJOL)

(Figs 1 and 2). A week later, an endoscopic retrograde cholangiopancreatography. (ERCP) examination was performed. This showed no filling of the right posterior sectoral ducts but normal opacification of the other ducts. (Figs 3a and b). These findings led to the diagnosis of an aberrant right posterior sectoral bile duct that ...

Imaging features of intraductal papillary neoplasm of the bile duct

International Nuclear Information System (INIS)

Liu Yubao; Li Meng; Zhong Xiaomei; Liu Zaiyi; Liang Changhong

2014-01-01

Objective: To investigate the CT and MRI features of intraductal papillary neoplasm of the bile duct (IPNB). Methods: Thirty eight patients with IPNB finally diagnosed by puncture biopsy or surgery were enrolled in this study. All the CT or MRI data were investigated retrospectively. Twenty one patients underwent CT examinations, 17 patients underwent MRI examinations. The features of IPNB including the distribution features of the nodules or masses, CT and MRI features of cholangiectasis, mucus were analyzed. The accuracy differences of CT and MRI for the preoperatively diagnosing mucus and tumor growing along mucous were compared by nonparametric test. Results: The lesions (including 5 patients with solitary lesions and 19 patients with multiple lesions) were located in intrahepatic bile duct in 24 patients, 3 patients occurred simultaneously in intrahepatic and portal bile duct, 2 lesions occurred in portal bile duct, 8 lesions occurred in common bile duct, the lesions of 1 patient occurred simultaneously in common bile duct, cystic duct and gallbladder. Seventeen and 11 patients appeared nodules locating in dilated bile duct on CT and MRI, respectively. Four and 5 patients appeared cystic lesions with multiple nodules of the liver on CT and MRI, respectively. Higher contrast enhancement on CT and MRI in arterial phase than that in portal vein and equilibrium phase were observed in 18 and 12 patients, respectively. Excluding the patients undergoing puncture, CT was better than MRI in evaluating whether the mucus was present, with the accuracies of 30.0% (6/20) and 6.3% (1/16) for CT and MRI, respectively (Z=2.58, P<0.05). CT was worse than MRI in preoperatively evaluating the features of tumor growing along mucous, with the accuracies of 77.8% (14/18) and 92.6% (13/14) for CT and MRI, respectively (Z=4.23, P<0.01). Conclusion: IPNB had the features of growing along mucous of the bile duct, nodule or mass in dilated bile duct and other features, CT and MRI are

Ursodeoxycholic acid treatment of vanishing bile duct syndromes

NARCIS (Netherlands)

Pusl, Thomas; Beuers, Ulrich

2006-01-01

Vanishing bile duct syndromes (VBDS) are characterized by progressive loss of small intrahepatic ducts caused by a variety of different diseases leading to chronic cholestasis, cirrhosis, and premature death from liver failure. The majority of adult patients with VBDS suffer from primary biliary

Positive predictive value of cholescintigraphy in common bile duct obstruction

International Nuclear Information System (INIS)

Lecklitner, M.L.; Austin, A.R.; Benedetto, A.R.; Growcock, G.W.

1986-01-01

Technetium-99m DISIDA imaging was employed in 400 patients to differentiate obstruction of the common bile duct from medical and other surgical causes of hyperbilirubinemia. Sequential anterior images demonstrated variable degrees of liver uptake, yet there was no evidence of intrabiliary or extrabiliary radioactivity for at least 4 hr after injection in 25 patients. Twenty-three patients were surgically documented to have complete obstruction of the common bile duct. One patient had hepatitis, and another had sickle cell crisis without bile duct obstruction. The remaining patients had either partial or no obstruction of the common bile duct. We conclude that the presence of liver uptake without evident biliary excretion by 4 hr on cholescintigraphy is highly sensitive and predictive of total obstruction of the common bile duct

Sound propagation in narrow tubes including effects of viscothermal and turbulent damping with application to charge air coolers

Science.gov (United States)

Knutsson, Magnus; Åbom, Mats

2009-02-01

Charge air coolers (CACs) are used on turbocharged internal combustion engines to enhance the overall gas-exchange performance. The cooling of the charged air results in higher density and thus volumetric efficiency. It is also important for petrol engines that the knock margin increases with reduced charge air temperature. A property that is still not very well investigated is the sound transmission through a CAC. The losses, due to viscous and thermal boundary layers as well as turbulence, in the narrow cooling tubes result in frequency dependent attenuation of the transmitted sound that is significant and dependent on the flow conditions. Normally, the cross-sections of the cooling tubes are neither circular nor rectangular, which is why no analytical solution accounting for a superimposed mean flow exists. The cross-dimensions of the connecting tanks, located on each side of the cooling tubes, are large compared to the diameters of the inlet and outlet ducts. Three-dimensional effects will therefore be important at frequencies significantly lower than the cut-on frequencies of the inlet/outlet ducts. In this study the two-dimensional finite element solution scheme for sound propagation in narrow tubes, including the effect of viscous and thermal boundary layers, originally derived by Astley and Cummings [Wave propagation in catalytic converters: Formulation of the problem and finite element scheme, Journal of Sound and Vibration 188 (5) (1995) 635-657] is used to extract two-ports to represent the cooling tubes. The approximate solutions for sound propagation, accounting for viscothermal and turbulent boundary layers derived by Dokumaci [Sound transmission in narrow pipes with superimposed uniform mean flow and acoustic modelling of automobile catalytic converters, Journal of Sound and Vibration 182 (5) (1995) 799-808] and Howe [The damping of sound by wall turbulent shear layers, Journal of the Acoustical Society of America 98 (3) (1995) 1723-1730], are

Common Bile Duct Perforation Due to Tuberculosis: A Case Report

OpenAIRE

Razman Jarmin; Shaharin Shaharuddin

2004-01-01

A young man with HIV presented with biliary peritonitis secondary to spontaneous common bile duct perforation. Investigation revealed that the perforation was due to Mycobacterium tuberculosis. Tuberculosis of the bile duct is uncommon and usually presents with obstructive jaundice due to stricture. Bile duct perforation due to tuberculosis is extremely rare. Its management is discussed.

Trypsin level in gallbladder bile and ductitis and width of the cystic duct.

Science.gov (United States)

Vracko, J; Wiechel, K L

2000-01-01

The change from laparotomy to laparoscopy for cholecystectomy has raised the question of how to manage concomitant bile duct stones. The present-day interest--and controversy--has focused on a transcystic approach reported to be feasible in 66-96% of cases, but without explaining the necessary prerequisite: the widening of the cystic duct. The cystic duct, wide mainly in patients with bile duct stones, has been reported to be highly variable: from strictured to very wide. The present study aims at comparing the trypsin level in the gallbladder bile and the cystic duct morphology and width in patients with and without bile duct stones. A prospective series of 63 gallstone patients, 30 with and 33 without bile duct stones (controls), underwent cholecystectomy and bile duct clearance. The study includes the trypsin level in the gallbladder bile, the width and morphology of the cystic duct, and the size of the gallstones. The patients with bile duct stones had, in contrast to the controls, higher trypsin levels in the gallbladder bile (P extraction feasible.

Thermal performance test of the hot gas ducts of HENDEL

International Nuclear Information System (INIS)

Hishida, M.; Kunitomi, K.; Ioka, I.; Umenishi, K.; Tanaka, T.; Shimomura, H.; Sanokawa, K.

1984-01-01

A hot gas duct provided with internal thermal insulation is to be used for high-temperature gas-cooled reactors (HTGR). This type of hot gas duct has not been used so far in industrial facilities, and only a couple of tests on such a large-scale model of a hot gas duct have been conducted. The present report deals with the results of the thermal performance of the single tube type hot gas ducts which are installed as parts of a helium engineering demonstration loop (HENDEL). Uniform temperature and heat flux distribution at the surface of the duct were observed, the experimental correlations being obtained for the effective thermal conductivity of the internal thermal insulation layer. The measured temperature distribution of the pressure tube was in good agreement with the calculation by a TRUMP heat transfer computer code. The temperature distribution of the inner tube of the co-axial hot gas duct was evaluated and no hot spot was detected. These results would be very valuable for the design and development of HTGR. (orig.)

Agenesis of the gallbladder with hypoplastic cystic duct diagnosed at laparoscopy.

Science.gov (United States)

Kwon, A-Hon; Yanagimoto, Hiroaki; Matsui, Yoichi; Imamura, Atsushi

2006-08-01

An 86-year-old man was admitted to our department with complaints of intermittent upper abdominal pain. Ultrasonography of the abdomen showed dilated extrahepatic bile ducts containing stones; however, the gallbladder was not clearly identified. Magnetic resonance cholangiopancreatography showed dilated extrahepatic ducts and choledocholithiasis without gallbladder visualization. The stone extraction was performed with endoscopic sphincterotomy. Three-dimensional images using spiral-computed tomography after intravenous-infusion cholangiography clearly demonstrated an obstruction of the cystic duct. The patient was scheduled for laparoscopic cholecystectomy. At laparoscopy, the gallbladder fossa was not identified on the undersurface of the liver. Despite a thorough examination of the intrahepatic (left-sided within the lesser omentum), retroperitoneal, retrohepatic (within the falciform ligament), retroduodenal, and retropancreatic areas using laparoscopic ultrasonography, the gallbladder was not found. After careful dissection of the hepatoduodenal ligament, the dilated extrahepatic bile duct and a 1-cm length of hypoplastic cystic duct were found. Gallbladder agenesis is usually accompanied by the lack of the cystic duct. The present case is the third report of gallbladder agenesis with a patent or hypoplastic cystic duct.

Cystic duct closure by sealing with bipolar electrocoagulation

DEFF Research Database (Denmark)

Schulze, S; Damgaard, B; Jørgensen, Lars Nannestad

2010-01-01

BACKGROUND: Cystic duct leakage after cholecystectomy is not uncommon and is a potentially serious complication. The aim of this study was to assess a bipolar sealing system (LigaSure) for closure of the cystic duct. METHODS: The records from consecutive laparoscopic cholecystectomies performed i...

Common Bile Duct Perforation Due to Tuberculosis: A Case Report

Directory of Open Access Journals (Sweden)

Razman Jarmin

2004-10-01

Full Text Available A young man with HIV presented with biliary peritonitis secondary to spontaneous common bile duct perforation. Investigation revealed that the perforation was due to Mycobacterium tuberculosis. Tuberculosis of the bile duct is uncommon and usually presents with obstructive jaundice due to stricture. Bile duct perforation due to tuberculosis is extremely rare. Its management is discussed.

Measured Performance of a Varied Airflow Small-Diameter Duct System

Energy Technology Data Exchange (ETDEWEB)

Poerschke, Andrew [IBACOS, Inc., Pittsburgh, PA (United States)

2017-03-01

This study tests the performance of a variable airflow small-diameter duct heating, ventilation, and air conditioning (HVAC) system in a new construction unoccupied low-load test house in Pittsburgh, Pennsylvania. The duct system was installed entirely in conditioned space and was operated from the winter through summer seasons. Measurements were collected on the in-room temperatures and energy consumed by the air handler and heat pump unit. Operation modes with three different volumes of airflow were compared to determine the ideal airflow scenario that maximizes room-to-room thermal uniformity while minimizing fan energy consumption. Black felt infrared imagery was used as a measure of diffuser throw and in-room air mixing. Measured results indicate the small-diameter, high velocity airflow system can provide comfort under some conditions. Solar heat gains resulted in southern rooms drifting beyond acceptable temperature limits. Insufficient airflow to some bedrooms also resulted in periods of potential discomfort. Homebuilders or HVAC contractors can use these results to assess whether this space conditioning strategy is an attractive alternative to a traditional duct system. The team performed a cost analysis of two duct system configurations: (1) a conventional diameter and velocity duct system, and (2) the small-diameter duct system. This work applies to both new and retrofit homes that have achieved a low heating and cooling density either by energy conservation or by operation in a mild climate with few heating or cooling degree days. Guidance is provided on cost trade-offs between the conventional duct system and the small-diameter duct system.

Measured Performance of a Varied Airflow Small-Diameter Duct System

Energy Technology Data Exchange (ETDEWEB)

Poerschke, Andrew [IBACOS, Inc., Pittsburgh, PA (United States)

2017-03-16

This study tests the performance of a variable airflow small-diameter duct heating, ventilation, and air conditioning (HVAC) system in a new construction unoccupied low-load test house in Pittsburgh, Pennsylvania. The duct system was installed entirely in conditioned space and was operated from the winter through summer seasons. Measurements were collected on the in-room temperatures and energy consumed by the air handler and heat pump unit. Operation modes with three different volumes of airflow were compared to determine the ideal airflow scenario that maximizes room-to-room thermal uniformity while minimizing fan energy consumption. Black felt infrared imagery was used as a measure of diffuser throw and in-room air mixing. Measured results indicate the small-diameter, high velocity airflow system can provide comfort under some conditions. Solar heat gains resulted in southern rooms drifting beyond acceptable temperature limits. Insufficient airflow to some bedrooms also resulted in periods of potential discomfort. Homebuilders or HVAC contractors can use these results to assess whether this space conditioning strategy is an attractive alternative to a traditional duct system. The team performed a cost analysis of two duct system configurations: (1) a conventional diameter and velocity duct system, and (2) the small-diameter duct system. This work applies to both new and retrofit homes that have achieved a low heating and cooling density either by energy conservation or by operation in a mild climate with few heating or cooling degree days. Guidance is provided on cost trade-offs between the conventional duct system and the small-diameter duct system.

Extracorporeal shock-wave lithotripsy of bile duct stones

International Nuclear Information System (INIS)

Lee, Jong Tae; Kim, Myung Joon; Yoo, Hyung Sik; Suh, Jung Ho; Lee, Moo Sang; Jo, Jang Hwan; Kim, Byung Ro

1989-01-01

During the past one and half year, we performed ESWL therapy in 13 patients with common bile duct and intrahepatic duct stones, applying Lithostar-R (Siemens co. West Germany) and analyzed their results. In 13 patients, 9 residual common bile duct stones and 7 intrahepatic duct stones were selected postoperatively. The size of stones were ranged from 0.7 cm to 3.5 cm in diameter. 2 stones were multiple and the remained 14 were single in number. The visualization of stones were done with fluoroscopy after the injection of contrast media via cholangiographic T-tube or ERCP. ESWL were applied continuously until stone disintegration was visible, or upto maximum number of 3500 discharge of shock wave. If not disintegrated upto 3500, patients were underwent second or third lithotripsy session with interval of one week. Our results showed that among 9 common bile duct stones, 4 were completely disintegrated and passed out spontaneously, but 3 partially fragmented and removed by the additional procedure. 2 were failed. Among 7 intrahepatic stones, 3 completely and 2 partially were succeeded. One stone partially fragmented were retained without removal and other one were failed. Skin petechia in all patients were revealed on the entry port of shock wave, but no serous complication was not occurred

Extracorporeal shock-wave lithotripsy of bile duct stones

Energy Technology Data Exchange (ETDEWEB)

Lee, Jong Tae; Kim, Myung Joon; Yoo, Hyung Sik; Suh, Jung Ho; Lee, Moo Sang; Jo, Jang Hwan; Kim, Byung Ro [Yonsei University College of Medicine, Seoul (Korea, Republic of)

1989-12-15

During the past one and half year, we performed ESWL therapy in 13 patients with common bile duct and intrahepatic duct stones, applying Lithostar-R (Siemens co. West Germany) and analyzed their results. In 13 patients, 9 residual common bile duct stones and 7 intrahepatic duct stones were selected postoperatively. The size of stones were ranged from 0.7 cm to 3.5 cm in diameter. 2 stones were multiple and the remained 14 were single in number. The visualization of stones were done with fluoroscopy after the injection of contrast media via cholangiographic T-tube or ERCP. ESWL were applied continuously until stone disintegration was visible, or upto maximum number of 3500 discharge of shock wave. If not disintegrated upto 3500, patients were underwent second or third lithotripsy session with interval of one week. Our results showed that among 9 common bile duct stones, 4 were completely disintegrated and passed out spontaneously, but 3 partially fragmented and removed by the additional procedure. 2 were failed. Among 7 intrahepatic stones, 3 completely and 2 partially were succeeded. One stone partially fragmented were retained without removal and other one were failed. Skin petechia in all patients were revealed on the entry port of shock wave, but no serous complication was not occurred.

ATP release, generation and hydrolysis in exocrine pancreatic duct cells

DEFF Research Database (Denmark)

Kowal, Justyna Magdalena; Yegutkin, G.G.; Novak, Ivana

2015-01-01

Extracellular adenosine triphosphate (ATP) regulates pancreatic duct function via P2Y and P2X receptors. It is well known that ATP is released from upstream pancreatic acinar cells. The ATP homeostasis in pancreatic ducts, which secrete bicarbonate-rich fluid, has not yet been examined. First, ou...... may be important in pancreas physiology and potentially in pancreas pathophysiology....... aim was to reveal whether pancreatic duct cells release ATP locally and whether they enzymatically modify extracellular nucleotides/sides. Second, we wished to explore which physiological and pathophysiological factors may be important in these processes. Using a human pancreatic duct cell line, Capan...

Computed tomography of hepatocellular carcinoma. Dilatation of intrahepatic bile duct

Energy Technology Data Exchange (ETDEWEB)

Choi, Soomi; Nakamura, Hitonobu; Tanaka, Ken; Hori, Shinichi; Tokunaga, Kou [Osaka Univ. (Japan). Faculty of Medicine

1983-10-01

Based on a series of CT of the liver in 125 patients with hepatoma and 45 patients with metastatic hepatic tumors, the mode of dilatation of the intrahepatic bile duct was examined. In patients with hepatoma, partia dilatations of intrahepatic bile duct were more commonly seen than general dilatations. On the other hand, there was no case of partial dilatation of the intrahepatic bile duct in patients with metastatic hepatic tumors. It could be concluded that partial dilatation of the intrahepatic bile duct is an useful CT finding to make a diagnosis of hepatoma, particularly to differentiate hepatoma from metastatic hepatic tumor.

A Review of Double Common Bile Duct and Its Sequelae.

Science.gov (United States)

Kolli, Sindhura; Etienne, Denzil; Reddy, Madhavi; Shahzad, Ghulamullah

2018-02-01

A double or accessory common bile duct (ACBD) is a rare congenital anomaly. We report the case of a 60-year-old American Asian male, who was found to have a double or duplicated common bile duct after being admitted for evaluation of a pancreatic mass. A duplicated bile duct has the same mucosa histologically as a single bile duct. However, the opening of a duplicated bile duct lacks a sphincter allowing retrograde flow of gut contents which results in a higher probability of intraductal calculus formation. On rare occasions, it can predispose to liver abscesses, pancreatitis, pancreatic cancer, gallbladder cancer, gastric cancer, and ampullary cancer depending on the location of the opening of the ACBD. We present an integrative review of the limited cases of ACBD with correlation to the current case and discussion regarding the aspects of diagnosis and management.

Effect of discharge duct geometry on centrifugal fan performance and noise emission

Science.gov (United States)

Nelson, David A.; Butrymowicz, William; Thomas, Christopher

2005-09-01

Non-ideal inlet and discharge duct geometries can cause significant changes to both the aerodynamic performance (``fan curve'') and specific sound power emission of a fan. A proper understanding of actual installed performance, as well as a good estimate of the system backpressure curve, is critical to achieving flow and acoustic goals as well as other criteria such as power consumption, mass and volume. To this end a battery of ISO 10302 tests was performed on a blower assembly which supports the Advanced Animal Habitat, being developed by ORBITEC for deployment on the International Space Station. The blower assembly consists of (4) identical centrifugal fans that, amongst themselves and across two prototypes, incorporated several discharge geometries. The inlet geometries were identical in all cases. Thus by comparing the dimensionless pressure-flow and noise emission characteristics across the cases, significant insight into the nature and potential magnitude of these effects is gained.

Flow in curved ducts of varying cross-section

Science.gov (United States)

Sotiropoulos, F.; Patel, V. C.

1992-07-01

Two numerical methods for solving the incompressible Navier-Stokes equations are compared with each other by applying them to calculate laminar and turbulent flows through curved ducts of regular cross-section. Detailed comparisons, between the computed solutions and experimental data, are carried out in order to validate the two methods and to identify their relative merits and disadvantages. Based on the conclusions of this comparative study a numerical method is developed for simulating viscous flows through curved ducts of varying cross-sections. The proposed method is capable of simulating the near-wall turbulence using fine computational meshes across the sublayer in conjunction with a two-layer k-epsilon model. Numerical solutions are obtained for: (1) a straight transition duct geometry, and (2) a hydroturbine draft-tube configuration at model scale Reynolds number for various inlet swirl intensities. The report also provides a detailed literature survey that summarizes all the experimental and computational work in the area of duct flows.

Foley Sounds vs Real Sounds

DEFF Research Database (Denmark)

Trento, Stefano; Götzen, Amalia De

2011-01-01

This paper is an initial attempt to study the world of sound effects for motion pictures, also known as Foley sounds. Throughout several audio and audio-video tests we have compared both Foley and real sounds originated by an identical action. The main purpose was to evaluate if sound effects...

Hepatocellular carcinoma localized in the bile duct lumen: two case report

Energy Technology Data Exchange (ETDEWEB)

Bae, Kyeung Kug; Chang, Jay Chun [Yeungnam Univ. School of Medicine, Seoul (Korea, Republic of)

1998-10-01

Intrabile duct tumor growth of hepatocellular carcinoma is an uncommon manifestation, but intraluminal bile duct hepatocellular carcinoma without primary hepatic parenchymal lesions is extremely rare. To our knowledge, only a few case reports have been published. We encountered two cases of primary hepatocellular carcinoma arising in the bile duct;serum alpha-fetoprotein levels were within the normal limits. Both showed the following characteristic radiologic features: (1) Cholangiography revealed filling defects within the dilated bile duct; (2) two-phase abdominal CT showed enhancement during the arterial-dominant phase and washout during the tissue equilibrium phase, as in typical HCC; and (3) hepateic arteriography revealed hypervascular tumor staining. Surgery was performed and the resected specimen showed no detectable primary hepatic parenchymal mass;on the basis of the pathologic finding, intraluminal bile duct hepatocellular carcinoma was confirmed. We cautiously assume that this peculiar type of HCC may arise primarily from bile duct mucosa.=20.

Clinical and cholangiographic evaluation of bile duct carcinoma

International Nuclear Information System (INIS)

Park, Yeon Won; Kim, So Seon; Kim, Ho Joon; Joh, Young Duk; Chun, Byung Hee

1986-01-01

40 cases of bile duct carcinoma gathered over a 6-year period at Kosin Medical College were reviewed and their clinical and cholangiographic findings were as follows: 1. There were 29 males and 11 females (the ratio of men to women, 2.6:1) ranging from 37 to 74 years of age. The majority (70% of cases) were in 4th and 5th decades. 2. Clinical symptoms and signs: jaundice in 95%, RUQ or epigastric pain in 75%, pruritus in 52.5%, dark urine in 35%, weight loss in 32.5%, fever and chills in 22.5%, clay colored stool in 12.5%, and palpable mass in 12.5%. 3. Lab. findings: elevated serum total bilirubin (above 20.0mg% in 45%, 10.0-19.9mg% in 22.5%, 5.0-9.9mg% in 20%, 1.3-4.9mg% in 5%), elevated alkaline phosphatase in 95%. Clonorchiasis were noted in 17.5%. 4. Histologic findings were adenocarcinoma in most cases. 5. The location of bile duct carcinoma were common hepatic duct in 35%, common bile duct in 32.5%, porta hepatic in 12.5%, junction with cystic duct in 10% and diffuse form in 10%. 6. In 33 cases, PTC or post-operative cholangiographic examination were done. And the most frequent findings were dilatation of the proximal bile duct and abrupt narrowing or complete obstruction of distal lumen. In 27 cases (82%), complete obstruction of bile duct were noted. Attempts were made to analyze the type of obstruction: Constricted type in 39%, Nipple type in 18%, round or flat type (smooth or slightly irregular) in 15%, and serrated type in 9%. Incomplete obstruction were noted in 6 cases (18%). Among them, abrupt narrowing of lumen was noted in 9% and diffuse narrowing in 9%. 7. ERCP was done in 7 cases. Findings were: constricted type in 42.6%, constricted and slightly irregular type in 14.3%, downward convexity in 14.3%, diffuse irregular narrowing in 14.3% and intraluminal filing defect in 14.3%.

Conservative Treatment for Cystic Duct Stenosis in a Child

Directory of Open Access Journals (Sweden)

Marco Gasparetto

2013-01-01

Full Text Available Introduction. Few cases of common bile duct stenosis have been reported in the literature, and observations of strictures in the cystic duct are even more rare. Surgical cholecystectomy is the treatment needed in most cases of gallbladder hydrops. This paper describes the diagnosis and successful medical treatment of a rare pediatric case of cystic duct stenosis and gallbladder hydrops. Case Report. A formerly healthy one-year-old girl was admitted with colicky abdominal pain. Blood tests were normal, except for an increase in transaminases. Abdominal ultrasound excluded intestinal intussusception and identified a distended gallbladder with biliary sludge. MR cholangiography revealed a dilated gallbladder containing bile sediment and no detectable cystic duct, while the rest of the intra- and extrahepatic biliary tree and hepatic parenchyma were normal. This evidence was consistent with gallbladder hydrops associated with cystic duct stenosis. The baby was treated with i.v. hydration, corticosteroids, antibiotics, and ursodeoxycholic acid. Her general condition rapidly improved, with no further episodes of abdominal pain and normalization of liver enzymes. This allowed to avoid cholecystectomy, and the child is well 1.5 years after diagnosis. Conclusions. Although cholecystectomy is usually necessary in case of gallbladder hydrops, our experience suggests that surgical procedures can be avoided when the distension is caused by a cystic duct stenosis.

Relationship Between Bile Duct Reconstruction and Complications in Living Donor Liver Transplantation.

Science.gov (United States)

Miyagi, S; Kawagishi, N; Kashiwadate, T; Fujio, A; Tokodai, K; Hara, Y; Nakanishi, C; Kamei, T; Ohuchi, N; Satomi, S

2016-05-01

In living donor liver transplantation (LDLT), the recipient bile duct is thin and short. Bile duct complications often occur in LDLT, with persistent long-term adverse effects. Recently, we began to perform microsurgical reconstruction of the bile duct. The purpose of this study was to investigate the relationship between bile duct reconstruction methods and complications in LDLT. From 1991 to 2014, we performed 161 LDLTs (pediatric:adult = 90:71; left lobe:right lobe = 95:66). In this study, we retrospectively investigated the initial bile duct complications in LDLT and performed univariate and multivariate analyses to identify the independent risk factors for complications. The most frequent complication was biliary stricture (9.9%), followed by biliary leakage (6.8%). On univariate and multiple logistic regression analysis, the independent risk factors for biliary stricture were bile leakage (P = .0103) and recurrent cholangitis (P = .0077). However, there were no risk factors for biliary leakage on univariate analysis in our study. The reconstruction methods (hepaticojejunostomy or duct-to-duct anastomosis) and reconstruction technique (with or without microsurgery) were not risk factors for biliary stricture and leakage. In this study, the most frequent complication of LDLT was biliary stricture. The independent risk factors for biliary stricture were biliary leakage and recurrent cholangitis. Duct-to-duct anastomosis and microsurgical reconstruction of the bile duct were not risk factors for biliary stricture and leakage. Copyright © 2016 Elsevier Inc. All rights reserved.

An experimental study on microcholangiographic manifestation in extrahepatic bile duct obstruction

International Nuclear Information System (INIS)

Lee, Yul; Kang, Heung Sik; Park, Jae Hyung; Kim, Chu Wan

1987-01-01

Microcholangiographic using microbarium was done for radiological observation of the morphology of intrahepatic microbiliary system and its charge after extrahepatic bile duct obstruction. Regurgitation of microbarium into the systemic circulation was also observed. Extrahepatic bile ducts of 40 rabbits were ligated and microcholangiography was done just after ligation, after 1 day, 3 days and 5 days. Injection pressure of microbarium was 58 cm H 2 O in 20 rabbits and 93 cm H 2 O in another 20 rabbits. Histologic findings of the liver was compared with microcholangiographic findings. The results were as follows: 1. In microcholangiography, interlobular bile ducts and ductules were well noted, but bile canaliculi were not visible. 2. After extrahepatic bile duct ligation, ductules and small interlobular bile ducts were tortuously dilated and proliferated. These findings progressed according as the time after extrahepatic bile duct ligation especially between 1 and 2 days. 3. Microbarium was regurgitated into hepatic sinusoids from a portal tract due to rupture of interlobular bile ducts or ductules, and this was observed only in limited portions of sample tissue sections, but could be found in most of 40 rabbits. From the above results, the morphology of intrahepatic microbiliary system and its change after extrahepatic bile duct obstruction could be radiologically observed with microcholangiography, so this technique could be used for experimental study about the biliary system.

Related issues in repair of bile duct injury and traumatic biliary stricture

Directory of Open Access Journals (Sweden)

WANG Shuguang

2017-02-01

Full Text Available Inappropriate treatment of bile duct injury and traumatic biliary stricture may cause serious consequences such as recurrent cholangitis, formation of hepatolithiasis, and biliary cirrhosis. This article elaborates on the influencing factors for the effect of the repair of bile duct injury and traumatic biliary stricture, repair principles, timing of repair or reconstruction, and related methods and techniques. It is pointed out that if there is no significant local infection and the bile duct wall defect is ＜2 cm, end-to-end anastomosis should be used for repair; if the bile duct wall defect is ＞2 cm, Roux-en-Y hepaticojejunostomy should be used for reconstruction. If the upper wall of the bile duct had a large defect and the lower wall has an integral structure, pedicled umbilical vein graft, pedicled jejunal wall seromuscular flap, or gastric wall seromuscular flap should be used for repair. The patients with severe congestion and edema at the site of injury should be treated with sufficient external drainage of the injured bile duct and then selective repair or reconstruction. Patients with hepatic duct stenosis in the liver lobe or hepatic segments and liver tissue atrophy can be treated with hepalobectomy or segmental hepatectomy. The key to successful repair is exposure and removal of high hilar bile duct stricture, while segmental hepatectomy of the Ⅳb segment can fully expose the left and right hepatic pedicles and help with the incision of the left and right hepatic ducts and secondary hepatic ducts, and therefore, it is a good method for exposing high bile duct stricture.

78 FR 13869 - Puget Sound Energy, Inc.; Puget Sound Energy, Inc.; Puget Sound Energy, Inc.; Puget Sound Energy...

Science.gov (United States)

2013-03-01

...-123-LNG; 12-128-NG; 12-148-NG; 12- 158-NG] Puget Sound Energy, Inc.; Puget Sound Energy, Inc.; Puget Sound Energy, Inc.; Puget Sound Energy, Inc.; Puget Sound Energy, Inc.; CE FLNG, LLC; Consolidated...-NG Puget Sound Energy, Inc Order granting long- term authority to import/export natural gas from/to...

Radiological study on the change of duct-ligated parotid gland

International Nuclear Information System (INIS)

Ohnishi, Takashi

1994-01-01

The change of the parotid gland with time following ligation of the main duct was investigated. The duct-ligated parotid gland in rabbit was examined by salivary gland scintigraphy with 99m Tc-pertechnetate ( 99m TcO 4 - ), sialography and microscopic observation. The third day after ligation of the main duct, the outward form of the parotid gland on the static scintigram was not well-defined. On the seventh day, 99m TcO 4 - accumulation was decreased slightly. On the 14th day, atrophy of the parotid gland occurred. The degree of atrophy produced by ligation increases as the duration of the ligation increases. On the 42nd day, the presence of the parotid gland was not recorded practically. The main duct was dilated on the third day. On the seventh day, the intraglandular ducts were bent and strictured. Disappearance of the peripheral duct and atrophy of the parotid gland parenchyma was observed. On microscopic observation, the intraglandular tributaries and the lumen were dilated on the third day. And the reticular fiber was observed that was irregularly formed in parts. The acinar cells were pressed by large and small dilated lumen on the seventh day. On the 14th day, the collagenous fiber around the acini and the duct was increased still more. In addition, fibrosis of the lobule interspace was observed. The degree of atrophy of the acini and lobule was increased maximally on the 42nd day. These results of the salivary gland scintigraphy closely connected with sialograms and microscopic findings. The parotid gland tissue decreases and changings of the duct system were indicated by these imaging methods in detail. (author)

Modified duval procedure for small-duct chronic pancreatitis without head dominance.

Science.gov (United States)

Oida, Takatsugu; Aramaki, Osamu; Kano, Hisao; Mimatsu, Kenji; Kawasaki, Atsushi; Kuboi, Youichi; Fukino, Nobutada; Kida, Kazutoshi; Amano, Sadao

2011-01-01

In the case of small-duct chronic pancreatitis, surgery for pain relief is broadly divided into resection and drainage procedures. These procedures should be selected according to the location of dominant lesion, diameter of the pancreatic duct and extent of the disease. The appropriate procedure for the treatment of small-duct chronic pancreatitis, especially small-duct chronic pancreatitis without head dominance, remains controversial. We developed the modified Duval procedure for the treatment of small-duct chronic pancreatitis without head dominance and determined the efficacy of this procedure. We retrospectively studied 14 patients who underwent surgical drainage with or without pancreatic resection for chronic pancreatitis with small pancreatic duct (Puestow procedure group and the modified Duval procedure group. No complications occurred in the modified Duval group. In the modified Puestow procedure group, complete and partial pain relief were observed in 62.5%, and 37.5% of patients respectively. In contrast, complete pain relief was observed in all the patients in the modified Duval procedure group. Our modified Duval procedure is useful and should be considered the appropriate surgical technique for the treatment of small-duct chronic pancreatitis without head dominance.

A simple method to calculate the neutron flow through full ducts

International Nuclear Information System (INIS)

Faik Ouahab, Z.; Jehouani, A.; Ghassoun, J.; Senhou, N.; Groetz, J.E.

2010-01-01

Summary of a study of assessment of the probability for neutrons to be guided in a full duct with a square cross section and doubly bent. Two software have been developed, based on the Monte Carlo simulation, to compute the neutron transmission probability at the end of the duct. Results are in good agreement with that obtained with the MCNP-5 code. The neutron flow and probability at the duct end have been determined for different materials and different duct dimensions

Intracellular pH in rat pancreatic ducts

DEFF Research Database (Denmark)

Novak, I; Hug, M; Greger, R

1997-01-01

In order to study the mechanism of H+ and HCO3- transport in a HCO3- secreting epithelium, pancreatic ducts, we have measured the intracellular pH (pHi) in this tissue using the pH sensitive probe BCECF. We found that exposures of ducts to solutions containing acetate/acetic acid or NH4+/NH3...... buffers (20 mmol/l) led to pHi changes in accordance with entry of lipid-soluble forms of the buffers, followed by back-regulation of pHi by duct cells. In another type of experiment, changes in extracellular pH of solutions containing HEPES or HCO3-/CO2 buffers led to significant changes in pHi that did....... Under some conditions, these exchangers can be invoked to regulate cell pH....

Salivary duct carcinoma: a Danish national study

DEFF Research Database (Denmark)

Breinholt, Helle; Elhakim, Mohammad Talal; Godballe, Christian

2016-01-01

BACKGROUND: To present the first national series of salivary duct carcinoma patients, including survival rates and an analysis of prognostic factors. METHODS: By merging three Danish nationwide registries that encompass an entire population, 34 patients diagnosed with salivary duct carcinoma from......-rank test. RESULTS: Salivary duct carcinoma showed an incidence of 0.04/100.000 inhabitants/year. Distant recurrence was seen in 52% of patients. Five-year overall survival, disease-specific survival and recurrence-free survival were 32%, 42% and 35%, respectively. Univariate analyses suggested that overall...... carcinoma incidence averages to two episodes per year in the entire Kingdom of Denmark. With half of patients in this study experiencing distant recurrences and only a third surviving at 5 years, prognosis is dismal. Advanced overall stage, vascular invasion and involved resection margins all seem...

Scintigraphy of cysts of the common bile duct in children

International Nuclear Information System (INIS)

Mironov, S.P.; Akopyan, V.G.; Murieva, Z.D.; Tumanyan, G.T.; Mironova, E.S.

1984-01-01

Cyst of the common bile duct, the most frequent variant of cystic dilatation of the extrahepatic biliary tract, represents a serious diagnostic problem. 13 children with cysts of the common bile duct were studied by the method of dynamic scintigraphy with sup(99m)Tc-HIDA. The scintigraphic picture was characterized by the following signs: sacculated or spheroidal dilatation of the common bile duct, dilatation of the left or both lobular bile ducts, absence of the gall bladder visualization. Change of indicators of the hepatic function and the time of interstinal visualization reflects both the disorder of distal parts permeability and the degree of cyst drainage. An experience of radioisotropic cholegraphy application reveals, that the efficiency of preoperational diagnosis of cysts of the common bile duct increases as a result of the more accurate evaluation of the dynamic of improvement of absorptive-excretory hepatic function after different variants of operations

Effects of explosion-generated shock waves in ducts

International Nuclear Information System (INIS)

Busby, M.R.; Kahn, J.E.; Belk, J.P.

1976-01-01

An explosion in a space causes an increase in temperature and pressure. To quantify the challenge that will be presented to essential components in a ventilation system, it is necessary to analyze the dynamics of a shock wave generated by an explosion, with attention directed to the propagation of such a wave in a duct. Using the equations of unsteady flow and shock tube theory, a theoretical model has been formulated to provide flow properties behind moving shock waves that have interacted with various changes in duct geometry. Empirical equations have been derived to calculate air pressure, temperature, Mach number, and velocity in a duct following an explosion

Occlusion of the cystic duct by electrocoagulation: A radiologic technique

International Nuclear Information System (INIS)

Becker, C.D.; Quenville, W.F.; Burhenne, H.J.

1987-01-01

Chemical dissolution and extracorporeal shock wave lithotripsy are promising new methods for the treatment of cholelithiasis without cholecystectomy. Nonsurgical defunctionalization of the gallbladder is now required to prevent recurrent stone formation. The authors consider cystic duct occlusion to be the first step. Ten domestic pigs underwent transcatheter electrocoagulation of the cystic duct via a cholecystostomy under fluoroscopic control. Stricture formation was followed by complete cystic duct occlusion in all ten cases. After a follow-up period ranging from 2 to 17 weeks (mean, 13 weeks), the animals were killed. Histologic studies demonstrated that complete obliteration of the cystic duct lumen was due to fibrous scar formation

Forced convection heat transfer correlation for finned plates in a duct

International Nuclear Information System (INIS)

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

2014-01-01

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

HAARP-Induced Ionospheric Ducts

International Nuclear Information System (INIS)

Milikh, Gennady; Vartanyan, Aram

2011-01-01

It is well known that strong electron heating by a powerful HF-facility can lead to the formation of electron and ion density perturbations that stretch along the magnetic field line. Those density perturbations can serve as ducts for ELF waves, both of natural and artificial origin. This paper presents observations of the plasma density perturbations caused by the HF-heating of the ionosphere by the HAARP facility. The low orbit satellite DEMETER was used as a diagnostic tool to measure the electron and ion temperature and density along the satellite orbit overflying close to the magnetic zenith of the HF-heater. Those observations will be then checked against the theoretical model of duct formation due to HF-heating of the ionosphere. The model is based on the modified SAMI2 code, and is validated by comparison with well documented experiments.

Laparoscopic bile duct injury: understanding the psychology and heuristics of the error.

Science.gov (United States)

Dekker, Sidney W A; Hugh, Thomas B

2008-12-01

Bile duct injury is an important unsolved problem of laparoscopic cholecystectomy, occurring with unacceptable frequency even in the hands of experienced surgeons. This suggests that a systemic predisposition to the injury is intrinsic to cholecystectomy and indicates that an analysis of the psychology and heuristics of surgical decision-making in relation to duct identification may be a guide to prevention. Review of published reports on laparoscopic bile duct injury from 1997 to 2007 was carried out. An analysis was also carried out of the circumstances of the injuries in 49 patients who had transection of an extrahepatic bile duct and who were referred for reconstruction or were assessed in a medicolegal context. Special emphasis was placed on identifying the possible psychological aspects of duct misidentification. Review of published work showed an emphasis on the technical aspects of correct identification of the cystic duct, with few papers addressing the heuristics and psychology of surgical decision-making during cholecystectomy. Duct misidentification was the cause of injury in 42 out of the 49 reviewed patients (86%). The injury was not recognized at operation in 70% and delay in recognition persisted into the postoperative period in 57%. Underestimation of risk, cue ambiguity and visual misperception ('seeing what you believe') were important factors in misidentification. Delay in recognition of the injury is a feature consistent with cognitive fixation and plan continuation, which help construct and sustain the duct misidentification during the operation and beyond. Changing the 'culture' of cholecystectomy is probably the most effective strategy for preventing laparoscopic bile duct injury, especially if combined with new technical approaches and an understanding of the heuristics and psychology of the duct misidentification error. Training of surgeons for laparoscopic cholecystectomy should emphasize the need to be alert for cues that the incorrect

Abnormalities of intrahepatic bile ducts in extrahepatic biliary atresia.

Science.gov (United States)

Raweily, E A; Gibson, A A; Burt, A D

1990-12-01

The infantile cholangiopathies are a group of conditions associated with neonatal jaundice, which include extrahepatic biliary atresia, paucity of intra-hepatic bile ducts and disorders associated with persistence of fetal biliary structures, the so-called ductal plate malformations. Although previously regarded as distinct entities, it has recently been suggested that they may represent parts of a disease spectrum in which the principal process is one of bile duct destruction, the morphological manifestations in individual cases being influenced by the stage of intra-uterine development at which such injury occurs and by the site within the biliary system at which there is maximum damage. To further examine this concept, we have studied liver biopsy specimens from 37 neonates with extrahepatic biliary atresia, with particular reference to abnormalities of the intrahepatic bile ducts. Paucity of intrahepatic ducts, defined as a bile duct: portal tract ratio of less than 0.9, was identified in six cases (16.2%). In eight cases (21.6%) we found concentric tubular ductal structures similar to those observed in ductal plate malformations. In one case, both abnormalities could be demonstrated. Our findings support the concept that there is overlap between the various types of infantile cholangiopathy.

Performance study of solar air heater duct having absorber plate with V down perforated baffles

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Sunil Chamoli

2014-04-01

Full Text Available This paper presents results of a study of the performance of solar air heaters with V down perforated baffles as roughness on the air flow side of the absorber plate. Investigations have been carried out using a mathematical model to study the effects of ambient conditions, operating and design parameters on effective efficiency of such air heaters. The thermal and effective efficiencies differ only marginally at lower flow rates. With an increase in the flow rate, the difference between the thermal and effective efficiencies increases because of the increase in the pumping power. The results of the study are presented in the form of plots to show the effect of ambient, design and operating conditions on thermal and effective efficiency.

Primary Follicular Lymphoma of the Common Bile Duct Mimicking Cholangiocarcinoma

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Khaled Youssef Elbanna

2014-01-01

Full Text Available Primary non-Hodgkin′s lymphoma of the common bile duct is extremely rare. We present a case with history of inflammatory bowel disease and clinical manifestations of obstructive jaundice. Abdominal magnetic resonance imaging with magnetic resonance cholangiopancreatography (MRCP was done and demonstrated tight stricture at the middle part of common bile duct, and radiological findings were supportive of extra-hepatic cholangiocarcinoma. Whipple′s procedure was performed and the case was histopathologically proven to be non-Hodgkin′s lymphoma of follicular subtype involving the common bile duct. Lymphoma of the hepatobiliary system is usually present as secondary manifestation of systemic malignant lymphoma. However, primary malignant lymphomas arising from the hepatobiliary tree are extremely rare. The radiological appearance of common bile duct lymphoma is very similar to cholangiocarcinoma, making preoperative diagnosis very difficult, as in our present case. We also compare the imaging findings of our case to those seen in reported cases of follicular lymphoma of the common bile duct.

Spontaneous common bile duct perforation—A rare clinical entity

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Melissa Amberger

Full Text Available Introduction: Spontaneous common bile duct perforation is an uncommon clinical entity in both adults and children. Few case reports have been published since the first clinical description in 1882. Our work has been reported in line with SCARE criteria. Presentation of case: Herein, we describe the case of a 28 year-old female who suffered spontaneous common bile duct perforation while admitted for choledocholithiasis. Discussion: The perforation occurred while in-hospital, and extensive imaging and laboratory tests characterized the disease in detail. To our knowledge, this is the first report of spontaneous common bile duct perforation witnessed from pre-perforation through definitive management. Conclusion: Physicians and Surgeons should seek out this uncommon diagnosis in the patient with suspected Choledocholithiasis who suddenly become peritoneal on physical exam so that definitive care can be expedited. Keywords: Common bile duct, Biliary peritonitis, Choledocholithiasis

Bile Duct Cancer (Cholangiocarcinoma) Symptoms, Tests, Prognosis, and Stages (PDQ®)—Patient Version

Science.gov (United States)

Bile duct cancer, or cholangiocarcinoma, is rare. Bile ducts are tubes that carry bile between the liver, gallbladder, and small intestine. Bile duct cancer can occur in the intrahepatic, perihilar (Klatskin tumor), or distal extrahepatic area. Learn about tests to diagnose and the stages of bile duct cancer.

Evidence for a Na+-Ca2+ exchanger in rat pancreatic ducts

DEFF Research Database (Denmark)

Hug, M; Pahl, C; Novak, I

1996-01-01

Only recently has it been recognized that intracellular Ca2+ is an important cellular mediator in pancreatic ducts. The aim of the present study was to characterize the Ca2+ efflux pathway in ducts freshly prepared from rat pancreas. Lowering of extracellular Na+ concentration resulted in a signi......Only recently has it been recognized that intracellular Ca2+ is an important cellular mediator in pancreatic ducts. The aim of the present study was to characterize the Ca2+ efflux pathway in ducts freshly prepared from rat pancreas. Lowering of extracellular Na+ concentration resulted...

Shock absorber

International Nuclear Information System (INIS)

Housman, J.J.

1978-01-01

A shock absorber is described for use in a hostile environment at the end of a blind passage for absorbing impact loads. The shock absorber includes at least one element which occupies the passage and which is comprised of a porous brittle material which is substantially non-degradable in the hostile environment. A void volume is provided in the element to enable the element to absorb a predetermined level of energy upon being crushed due to impact loading

Design requirement on KALIMER blanket fuel assembly duct

International Nuclear Information System (INIS)

Hwang, Woan; Kang, H. Y.; Nam, C.; Kim, J. O.

1998-03-01

This document describes design requirements which are needed for designing the blanket fuel assembly duct of the KALIMER as design guidance. The blanket fuel assembly duct of the KALIMER consists of fuel rods, mounting rail, nosepiece, duct with pad, handling socket with pad. Blanket fuel rod consists of top end plug, bottom end plug with solid ferritic-martensitic steel rod and key way blanket fuel slug, cladding, and wire wrap. In the assembly, the rods are in a triangular pitch array, and the rod bundle is attached to the nosepiece with mounting rails. The bottom end of the assembly duct is formed by a long nosepiece which provides the lower restraint function and the paths for coolant inlet. This report contains functional requirements, performance and operational requirements, interfacing systems requirements, core restraint and interface requirements, design limits and strength requirements, system configuration and essential feature requirements, seismic requirements, structural requirements, environmental requirements, reliability and safety requirements, standard and codes, QA programs, and other requirements. (author). 20 refs., 4 figs

Heat transfer in an asymmetrically heated duct, 2

International Nuclear Information System (INIS)

Satoh, Isao; Kurosaki, Yasuo

1986-01-01

The objective of this article is to study theoretically and experimentally the effects of nonuniform heating on turbulent heat transfer characteristics for flow in a horizontal rectangular duct ; a vertical side wall was uniformly heated, and the other wall were insulated. In our theoretical approach, the zero-equation model for turbulent eddy viscosity was employed. The effects of mesh size of finite difference on the calculation results were examined, and some refined compensation for wall temperatures and wall shear stresses by no use of fine mesh were proposed to reduce the calculation time. The heat transfer coefficients in thermally developing region for a nonuniformly heated duct obtained from numerical solutions are larger than the one for uniformly heated case. The buoyancy effects on heat transfer were evaluated. However, it was seen that the secondary flow due to buoyancy force was hardly expected to enhance heat transfer in a turbulent duct flow. Experiments were performed to measure the velocity and temperature profiles in a turbulent duct flow with a nonuniform heated wall. The experimental results were in good agreement with the theoretical ones. (author)

Diagnosis of functional nasolacrimal duct obstruction using dacryoscintigraphy

International Nuclear Information System (INIS)

Lim, Hyun Wook; Sohn, Hyung Sun; Kim, Euy Neyng; Chung, Yong An; Kim, Sung Hoon; Chung, Soo Kyo

2000-01-01

To evaluate the value of dacryoscintigraphy in the assessment of patients with a clinical diagnosis of functional nasolacrimal duct obstruction. Dacryoscintigraphy was performed in symptomatic 35 lacrimal drainage systems in 18 patients (age range: 37 ∼76,8 males, 10 females) that were patent on syringing. Abnormalities were detected with dacryoscintigraphy in 75.8% of systems. The positive scintigrams were subdivided into those demonstrating prelacrimal sac delay (31.8%), delay at the lacrimal sac/junction (40.9%), or delay within the duct (27%). Dacryoscintigraphy is noninvasive useful technique in the assessment of the functional nasolacrimal duct obstruction and very sensitive at detecting abnormalities in patients with lid laxity caused by senile change and facial nerve palsy

Time course of collagen peak in bile duct-ligated rats.

Science.gov (United States)

Tarcin, Orhan; Basaranoglu, Metin; Tahan, Veysel; Tahan, Gülgün; Sücüllü, Ilker; Yilmaz, Nevin; Sood, Gagan; Snyder, Ned; Hilman, Gilbert; Celikel, Cigdem; Tözün, Nurdan

2011-04-28

One of the most useful experimental fibrogenesis models is the "bile duct-ligated rats". Our aim was to investigate the quantitative hepatic collagen content by two different methods during the different stages of hepatic fibrosis in bile duct-ligated rats on a weekly basis. We questioned whether the 1-wk or 4-wk bile duct-ligated model is suitable in animal fibrogenesis trials. Of the 53 male Wistar rats, 8 (Group 0) were used as a healthy control group. Bile duct ligation (BDL) had been performed in the rest. Bile duct-ligated rates were sacrificed 7 days later in group 1 (10 rats), 14 days later in group 2 (9 rats), 21 days later in group 3(9 rats) and 28 days later in group 4 (9 rats). Eight rats underwent sham-operation (Sham). Hepatic collagen measurements as well as serum levels of liver enzymes and function tests were all analysed. The peak level of collagen was observed biochemically and histomorphometricly at the end of third week (P fibrosis in bile duct-ligated rats is transient, i.e. reverses spontaneously after 3 weeks. This contrasts any situation in patients where hepatic fibrosis is progressive and irreversible as countless studies performed by many investigators in the same animal model.

Long-term assessments after pancreaticoduodenectomy with pancreatic duct invagination anastomosis

International Nuclear Information System (INIS)

Fujino, Yasuhiro; Matsumoto, Ippei; Sakai, Tetsuya; Ajiki, Tetsuo; Ueda, Takashi; Kuroda, Yoshikazu; Suzuki, Yasuyuki

2007-01-01

The purpose of this cohort was to evaluate the long-term patency of the anastomosis and the remnant pancreatic functions. Fifty-six consecutive patients undergoing a pancreaticoduodenectomy with pancreatic duct invagination anastomosis were enrolled in this study. During the follow-up, changes in the remnant pancreatic duct size, pancreatic exocrine and endocrine functions, and nutritional status were monitored. No seriously activated pancreatic fistula, no hemorrhagic complications, no reoperations, and no in-hospital deaths were observed after surgery. A dilatation of remnant pancreatic duct was detected a total of 37 times (51%) during annual computed tomography (CT) evaluations. Pancreatic dysfunctions were observed in a considerable number of patients (exocrine 4/12, 9/14, and 8/16, endocrine 9/35, 8/27, and 4/16 at 1, 2, and 3 postoperative years, respectively). Functional declines in the remnant pancreas, duct dilatation, and a decrease in the body mass index were observed from the first year. However, these data did not progressively deteriorate thereafter, at least during the first 3 postoperative years. This study demonstrated a significant correlation between the duct dilatation and endocrine dysfunction. Our pancreatic duct invagination anastomosis resulted in somewhat limited long-term outcomes, although it did prevent serious complications in the short-term. (author)

Seismic assessment of the Pickering pressure relief duct

International Nuclear Information System (INIS)

Ghobarah, A.

1995-05-01

The objectives of the study are to examine the structural response of the Pickering pressure relief duct when subjected to earthquake ground motion and to estimate the seismic withstand capacity of various components of the structural system on the basis of performance criteria consistent with the safety function of the duct. (author). 24 refs., 16 tabs., 31 figs

Optimized Matching Lift Unit Transmission Ratio of Engine Driven Ducted Fan

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Xiao Senlin

2018-01-01

Full Text Available As a kind of VTOL technology, ducted fan is not only used by many kinds of aircrafts, but also one of the trends of the future aircraft lift system, and attracts more and more attention. For an engine driven ducted fan lift unit, involving the engine and ducted fan matching problem, the form of transmission and transmission ratio are the key design parameters. In order to design and develop a ducted fan aircraft reasonably, a thrust test platform was set up to connect the engine with the ducted fan through the belt driving. The matching relationship between the engine and the transmission system was experimentally studied and the optimal transmission ratio was determined. The results showed that the optimal transmission ratio for the engine 1 is 2.2:1, and for the engine 2, the optimal transmission ratio should be 2.95:1 based on the current ducted and movable blade aerofoil design. At this time, the lift will exceed 130 kg•f, meeting the aircraft's original design requirements.

Carcinosarcoma of the Extrahepatic Bile Duct Presenting with Stone-like Radiological Findings.

Science.gov (United States)

Kumei, Shinsuke; Onishi, Yutaka; Ogura, Takeshi; Kusumoto, Chosei; Matsuno, Yasuko; Nishigami, Takashi; Maeda, Mitsuo; Harada, Masaru

2015-01-01

A 73-year-old woman was referred to our hospital due to epigastralgia and jaundice. The radiological findings showed a stone-like tumor in the extrahepatic bile duct. The patient was initially thought to have adenocarcinoma of the bile duct based on the findings of a pathological examination of the bile duct biopsy specimen and underwent pancreaticoduodenectomy; the final diagnosis of the lesion was so-called carcinosarcoma of the extrahepatic bile duct. She died of liver metastasis six months after the surgery. This case suggests that surgical resection is not adequate for achieving a radical cure, and the optimal treatment for extrahepatic bile duct carcinosarcoma should be established immediately.

Active noise control in a duct to cancel broadband noise

Science.gov (United States)

Chen, Kuan-Chun; Chang, Cheng-Yuan; Kuo, Sen M.

2017-09-01

The paper presents cancelling duct noises by using the active noise control (ANC) techniques. We use the single channel feed forward algorithm with feedback neutralization to realize ANC. Several kinds of ducts noises including tonal noises, sweep tonal signals, and white noise had investigated. Experimental results show that the proposed ANC system can cancel these noises in a PVC duct very well. The noise reduction of white noise can be up to 20 dB.

Shock absorbing structure

International Nuclear Information System (INIS)

Kojima, Naoki; Matsushita, Kazuo.

1992-01-01

Small pieces of shock absorbers are filled in a space of a shock absorbing vessel which is divided into a plurality of sections by partitioning members. These sections function to prevent excess deformation or replacement of the fillers upon occurrence of falling accident. Since the shock absorbing small pieces in the shock absorbing vessel are filled irregularly, shock absorbing characteristics such as compression strength is not varied depending on the direction, but they exhibit excellent shock absorbing performance. They surely absorb shocks exerted on a transportation vessel upon falling or the like. If existing artificial fillers such as pole rings made of metal or ceramic and cut pieces such as alumium extrusion molding products are used as the shock absorbing pieces, they have excellent fire-proofness and cold resistance since the small pieces are inflammable and do not contain water. (T.M.)

Muellerian duct cyst as a cause of acute infantile-onset epididymitis

Energy Technology Data Exchange (ETDEWEB)

Donkol, Ragab H.; Moghazy, Khaled [Gulf Specialist Hospital, Department of Radiology, P.O. Box 1444, Qatif (Saudi Arabia); Monib, Sherif [Gulf Specialist Hospital, Department of General Surgery, Qatif (Saudi Arabia)

2006-11-15

Muellerian duct cyst is a congenital anomaly that originates from remnants of the muellerian duct that usually regresses in utero. It is most commonly detected in adult males during the third and fourth decades of life. Muellerian duct cyst is rarely reported in infants less than 1 year of age, in whom diagnosis is difficult because of immaturity of the genital tract. In this case report, we describe the sonographic and CT appearance of a large intrapelvic muellerian duct cyst presenting with acute epididymitis in a 9-month-old infant. The embryological basis, imaging findings and relation to epididymitis are discussed. (orig.)

Muellerian duct cyst as a cause of acute infantile-onset epididymitis

International Nuclear Information System (INIS)

Donkol, Ragab H.; Moghazy, Khaled; Monib, Sherif

2006-01-01

Muellerian duct cyst is a congenital anomaly that originates from remnants of the muellerian duct that usually regresses in utero. It is most commonly detected in adult males during the third and fourth decades of life. Muellerian duct cyst is rarely reported in infants less than 1 year of age, in whom diagnosis is difficult because of immaturity of the genital tract. In this case report, we describe the sonographic and CT appearance of a large intrapelvic muellerian duct cyst presenting with acute epididymitis in a 9-month-old infant. The embryological basis, imaging findings and relation to epididymitis are discussed. (orig.)

Acoustic power balance in lined ducts

Science.gov (United States)

Eversman, W.

1979-01-01

It is shown that the two common definitions of acoustic energy density and intensity in uniform unlined ducts carrying uniform flow are compatible to the extent that both energy densities can be used in an appropriate variational principle to derive the convected wave equation. When the duct walls are lined both energy densities must be modified to account for the wall energy density. This results in a new energy conservation equation which utilizes a modified definition of axial power and accounts for wall dissipation. Computations in specific cases demonstrate the validity of the modified acoustic energy relation.

Hemodynamic characterization of chronic bile duct-ligated rats: effect of pentobarbital sodium

International Nuclear Information System (INIS)

Lee, S.S.; Girod, C.; Braillon, A.; Hadengue, A.; Lebrec, D.

1986-01-01

Systemic and splanchnic hemodynamics of the chronic bile duct-ligated rat were characterized by radioactive microspheres. Conscious and pentobarbital sodium-anesthetized, bile duct-ligated and sham-operated rats had cardiac output and regional organ blood flows determined. The conscious bile duct-ligated rat compared with the sham-operated showed a hyperdynamic circulation with an increased cardiac output and portal tributary blood flow. Pentobarbital sodium anesthesia induced marked hemodynamic changes in both sham-operated and bile duct-ligated rats. The latter group was especially sensitive to its effects; thus, comparison of cardiac output and portal tributary blood flow between anesthetized bile duct-ligated and sham-operated rats showed no significant differences. The authors conclude that the rat with cirrhosis due to chronic bile duct ligation is an excellent model for hemodynamic investigations but should be studied in the conscious state, since pentobarbital sodium anesthesia eliminated the hyperdynamic circulation

BACTERIOLOGICAL INVESTIGATION ON Fasciola hepatica AND CATTLE BILIARY DUCTS

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A. Panebianco

2009-03-01

Full Text Available The aim of this work was to investigate the occurrence of bacteria in Fasciola hepatica and into cattle biliary ducts containing the parasite. A total of 24 liver and 58 F. hepatica samples were analysed. In all biliary ducts and in 62,06% of parasite Enterobacteriaceae were isolated. The bacterial specie more frequently isolated from parasite were Citrobacter freundii (34%, Proteus mirabilis (18%, Providencia rettgeri (12%, Staphylococcus spp. (18%, Enterobacter spp. (12%. There doesn’t appear to be a correlation between bacterial specie from parasite and ducts. The Authors conclude with some related inspective consideration.

Preoperative intraluminal irradiation of the extrahepatic bile duct tumor

International Nuclear Information System (INIS)

Kamada, Tadashi; Tsujii, Hirohiko; Arimoto, Takuro; Irie, Goro.

1991-01-01

From 1984 through 1986, six patients with extrahepatic bile duct tumor were treated preoperatively with intraluminal irradiation of the bile duct. There were no unresectable cases and pathological examination of the surgical specimens showed moderate to remarkable tumor regression in all cases. Postoperative biliary tract hemorrhage occurred in 2 of 3 patients who received 60 Gy at a point 7.5 mm from the center of the source. With accurate preoperative diagnosis of the tumor extent and careful setting of the target area of intraluminal irradiation, improved local tumor control of extrahepatic bile duct tumor can be expected with this method. (author)

Tolerance of bile duct to intraoperative irradiation

International Nuclear Information System (INIS)

Sindelar, W.F.; Tepper, J.; Travis, E.L.

1982-01-01

In order to determine the effects of intraoperative radiation therapy of the bile duct and surrounding tissues, seven adult dogs were subjected to laparotomy and intraoperative irradiation with 11 MeV electrons. Two animals were treated at each dose level of 2000, 3000, and 4500 rads. A single dog which received a laparotomy and sham irradiation served as a control. The irradiation field consisted of a 5 cm diameter circle encompassing the extrahepatic bile duct, portal vein, hepatic artery, and lateral duodenal wall. The animals were followed clinically for mor than 18 months after treatment, and autopsies were performed on dogs that died to assess radiation-induced complications or tissue damage. All dogs developed fibrosis and mural thickening of the common duct, which appeared by 6 weeks following irradiation and which was dose-related, being mild at low doses and more severe at high doses. Hepatic changes were seen as early as 6 weeks after irradiation, consisting of periportal inflammation and fibrosis. The hepatic changes appeared earliest at the highest doses. Frank biliary cirrhosis eventually developed at all dose levels. Duodenal fibrosis appeared in the irradiation portal, being most severe at the highest doses and in some animals resulting in duodenal obstruction. No changes were observed in irradiated portions of portal vein and hepatic artery at any dose level. It was concluded that intraoperative radiation therapy delivered to the region of the common duct leads to ductal fibrosis, partial biliary obstruction with secondary hepatic changes, and duodenal fibrosis if bowel wall is included in the field. Clinical use of intraoperative radiation therapy to the bile duct in humans may require routine use of biliary and duodenal bypass to prevent obstructive complications

Practical use of CFD for air conditioning duct and defroster designing; Kucho duct defroster no CFD sekkei katsuyo

Energy Technology Data Exchange (ETDEWEB)

Okumura, K [Daihatsu Motor Co. Ltd., Osaka (Japan)

1997-10-01

The automobile industry have made effort to shorten the development period. Recently CFD (Computational Fluid Dynamics) on initial design stage becomes use for improvement of development efficiency. Although the practical guidepost (computed examples) for air conditioning duct and defroster are a little reported. This report presents how to optimize and standardize the calculational methods, calculational grid, boundary conditions for air conditioning duct and defroster nozzle in the practical use. Also we tried the discontinuous interface grid and the solution adaptive method. 2 refs., 17 figs.

Risk of pancreatitis after pancreatic duct guidewire placement during endoscopic retrograde cholangiopancreatography.

Directory of Open Access Journals (Sweden)

Yuki Ishikawa-Kakiya

Full Text Available Advanced techniques have been developed to overcome difficult cannulation cases in endoscopic retrograde cholangiopancreatography (ERCP. Pancreatic duct guidewire placement method (PGW is performed in difficult cannulation cases; it is possible that it places patients at risk of post-ERCP pancreatitis (PEP. The mechanism of PEP is still unclear, but pancreatic duct pressure and injury of pancreatic duct are known causes of PEP. Therefore, we hypothesized a relationship between pancreatic duct diameter and PEP and predicted that PGW would increase the risk of PEP in patients with non-dilated pancreatic ducts. This study aimed to investigate whether PGW increased the risk of PEP in patients with pancreatic duct diameter ≤ 3 mm.We analyzed 332 patients with pancreatic duct ≤ 3 mm who performed first time ERCP session. The primary endpoint was the rate of adverse event of PEP. We evaluated the risk of PEP in patients who had undergone PGW compared to those who had not, using the inverse probability of treatment weighting (IPTW analysis.PGW was found to be an independent risk factor for PEP by univariate analysis (odds ratio [OR], 2.45; 95% confidence interval [CI], 1.12-5.38; p = 0.03 after IPTW in patients with pancreatic duct diameter ≤ 3 mm. Adjusted for all covariates, PGW remained an independent risk factor for PEP (OR, 3.12; 95% CI, 1.33-7.33; p = 0.01.Our results indicate that PGW in patients with pancreatic duct diameter ≤ 3 mm increases the risk of PEP.

Mucocele of the cystic duct remnant after orthotopic liver transplant: a problem revisited.

Science.gov (United States)

Chatterjee, Suvadip; Das, Debasish; Hudson, Mark; Bassendine, Margaret Fiona; Scott, John; Oppong, Kofi Ernest; Sen, Gourab; French, Jeremy J

2011-06-01

Mucocele of the cystic duct remnant is an uncommon hepatobiliary complication of a liver transplant. Current practice usually involves either excising the cystic duct, or incorporating the distal end of the transected cystic duct into the suture line of the biliary anastomosis to ensure drainage. We report a patient who developed cystic duct remnant mucocele after the latter approach was adopted. We believe that this is likely related to delayed anastomotic stricturing, which prevented draining from the remnant cystic duct. We also discuss the incidence, pathology, investigations, and treatment of this condition.

Time course of collagen peak in bile duct-ligated rats

Directory of Open Access Journals (Sweden)

Snyder Ned

2011-04-01

Full Text Available Abstract Background One of the most useful experimental fibrogenesis models is the "bile duct-ligated rats". Our aim was to investigate the quantitative hepatic collagen content by two different methods during the different stages of hepatic fibrosis in bile duct-ligated rats on a weekly basis. We questioned whether the 1-wk or 4-wk bile duct-ligated model is suitable in animal fibrogenesis trials. Methods Of the 53 male Wistar rats, 8 (Group 0 were used as a healthy control group. Bile duct ligation (BDL had been performed in the rest. Bile duct-ligated rates were sacrificed 7 days later in group 1 (10 rats, 14 days later in group 2 (9 rats, 21 days later in group 3(9 rats and 28 days later in group 4 (9 rats. Eight rats underwent sham-operation (Sham. Hepatic collagen measurements as well as serum levels of liver enzymes and function tests were all analysed. Results The peak level of collagen was observed biochemically and histomorphometricly at the end of third week (P Conclusion We have shown that fibrosis in bile duct-ligated rats is transient, i.e. reverses spontaneously after 3 weeks. This contrasts any situation in patients where hepatic fibrosis is progressive and irreversible as countless studies performed by many investigators in the same animal model.

Surgical management of Stenson's duct injury using epidural catheter

African Journals Online (AJOL)

2012-07-05

Jul 5, 2012 ... Successful management of parotid duct injury depends on early diagnosis and appropriate intervention, failing of ... to diagnose and manage the parotid duct injuries using an “epidural catheter” which is often used for inducing spinal anesthesia. .... Water-soluble contrast media have a definite advantage.

Positioning of supporting-cable ducts in a prestressed concrete bridge

International Nuclear Information System (INIS)

Roetzer, H.

1981-01-01

Before inserting the supporting cables positioning of cable ducts in prestressed concrete bridges can be performed with the aid of radiation sources hauled through the ducts and localized by means of radiation monitors

An evaluation of damping ratios for HVAC duct systems using vibration test data

International Nuclear Information System (INIS)

Gunyasu, K.; Horimizu, Y.; Kawakami, A.; Iokibe, H.; Yamazaki, T.

1988-01-01

The function of Heating Ventilating Air Conditioning (HVAC) systems must be maintained including HVAC duct systems to keep the operation of safety-related equipment in nuclear power plants during earthquake excitations. Therefore, it is important to carry out seismic design for HVAC duct systems. In the previous aseismic design for HVAC duct systems, the 0.5% damping ratio has been used in Japan. In recent years, vibration tests, held on actual duct systems in nuclear power plants and mockup duct systems were performed in order to investigate damping ratios for HVAC duct systems. Based on the results, it was confirmed that the damping ratio for HVAC duct systems, evaluated from these tests, were much greater than the 0.5% damping ratio used in the previous aseismic design of Japan. The new damping ratio in aseismic design was proposed to be 2.5%. The present paper describes the results of the above mentioned investigation

CT differentiation of mucin-producing cystic neoplasms of the liver from solitary bile duct cysts.

Science.gov (United States)

Kim, Hyoung Jung; Yu, Eun Sil; Byun, Jae Ho; Hong, Seung-Mo; Kim, Kyoung Won; Lee, Jong Seok; Kim, So Yeon

2014-01-01

The purpose of this study was to identify the CT features required for differentiating mucin-producing cystic neoplasms of the liver (mucinous cystic neoplasms and cyst-forming intraductal papillary neoplasms of the bile duct) from solitary bile duct cysts. CT images of pathologically confirmed mucinous cystic neoplasms (n = 15), cyst-forming intraductal papillary neoplasms of the bile duct (n = 16), and solitary bile duct cysts (n = 31) were reviewed. Analysis of the CT findings included shape, presence of septa, location of septa (peripheral vs central), thickness of septa (thin vs thick), mosaic pattern, mural nodules, intracystic debris, calcification, upstream bile duct dilatation, downstream bile duct dilatation, and communication between a cystic lesion and the bile duct. The maximum size of a cystic lesion and the maximum size of the largest mural nodule were measured. The presence of septa, central septa, mural nodules, upstream bile duct dilatation, and downstream bile duct dilatation were found to be significant CT findings for differentiating mucinous cystic neoplasms and cyst-forming intraductal papillary neoplasms of the bile duct from solitary bile duct cysts (p bile duct were 87% (27 of 31) and 87% (27 of 31), respectively. When two of these five criteria were used in combination, the sensitivity and specificity for diagnosing mucinous cystic neoplasms and cyst-forming intraductal papillary neoplasms of the bile duct were 87% (27 of 31) and 87% (27 of 31), respectively [corrected]. With the use of specific CT criteria, mucin-producing cystic neoplasms of the liver can be differentiated from solitary bile duct cysts with a high degree of accuracy.

Heat Transfer Computations of Internal Duct Flows With Combined Hydraulic and Thermal Developing Length

Science.gov (United States)

Wang, C. R.; Towne, C. E.; Hippensteele, S. A.; Poinsatte, P. E.

1997-01-01

This study investigated the Navier-Stokes computations of the surface heat transfer coefficients of a transition duct flow. A transition duct from an axisymmetric cross section to a non-axisymmetric cross section, is usually used to connect the turbine exit to the nozzle. As the gas turbine inlet temperature increases, the transition duct is subjected to the high temperature at the gas turbine exit. The transition duct flow has combined development of hydraulic and thermal entry length. The design of the transition duct required accurate surface heat transfer coefficients. The Navier-Stokes computational method could be used to predict the surface heat transfer coefficients of a transition duct flow. The Proteus three-dimensional Navier-Stokes numerical computational code was used in this study. The code was first studied for the computations of the turbulent developing flow properties within a circular duct and a square duct. The code was then used to compute the turbulent flow properties of a transition duct flow. The computational results of the surface pressure, the skin friction factor, and the surface heat transfer coefficient were described and compared with their values obtained from theoretical analyses or experiments. The comparison showed that the Navier-Stokes computation could predict approximately the surface heat transfer coefficients of a transition duct flow.

Excluded segmental duct bile leakage: the case for bilio-enteric anastomosis.

Science.gov (United States)

Patrono, Damiano; Tandoi, Francesco; Romagnoli, Renato; Salizzoni, Mauro

2014-06-01

Excluded segmental duct bile leak is the rarest type of post-hepatectomy bile leak and presents unique diagnostic and management features. Classical management strategies invariably entail a significant loss of functioning hepatic parenchyma. The aim of this study is to report a new liver-sparing technique to handle excluded segmental duct bile leakage. Two cases of excluded segmental duct bile leak occurring after major hepatic resection were managed by a Roux-en-Y hepatico-jejunostomy on the excluded segmental duct, avoiding the sacrifice of the liver parenchyma origin of the fistula. In both cases, classical management strategies would have led to the functional loss of roughly 50 % of the liver remnant. Diagnostic and management implications are thoroughly discussed. Both cases had an uneventful postoperative course. The timing of repair was associated with a different outcome: the patient who underwent surgical repair in the acute phase developed no long-term complications, whereas the patient who underwent delayed repair developed a late stenosis requiring percutaneous dilatation. Roux-en-Y hepatico-jejunostomy on the excluded bile duct is a valuable technique in selected cases of excluded segmental duct bile leakage.

Various Transport Phenomena and Modeling in a Methane Reformer Duct for PEMFCs

International Nuclear Information System (INIS)

Jinliang Yuan; Fuan Ren; Jinliang Yuan; Bengt Sunden

2006-01-01

There are various physical processes (such as mass, heat and momentum transport) integrated with catalytic chemical reactions in a methane steam reforming duct. It is often found that endothermic and exothermic reactions in the ducts are strongly coupled by heat transfer from adjacent catalytic combustion ducts. In this paper, a three-dimensional calculation method is developed to simulate and analyze steam reforming of methane, and the effects on various transport processes in a steam reforming duct. The reformer conditions such as mass balances associated with the reforming reactions and gas permeation to/from the porous catalyst layer are applied in the analysis. The predicted results are presented and discussed for a composite duct consisting of a porous catalyst reaction area, the gas flow duct and solid layers. Parametric studies are conducted and the results show that the variables, such as fuel reformer temperatures and catalyst loadings, have significant effects on the transport processes and reformer performance. (authors)

[ENDOSONOGRAPHY IN THE DIFFERENTIAL DIAGNOSIS OF THE COMMON BILE DUCT STENOSIS].

Science.gov (United States)

Solodinina, E N; Starkov, Y G; Shumkin, L V

2015-01-01

The article states the results of examination and treatment of 57 patients with stenosis of the common bile duct of various genesis. The main aim of the work is criteria definition and evaluation of diagnostic significance of endosonography in the differential diagnosis of benign and malignant common bile duct stenosis. The paper presents a methodology of endoscopic ultrasound and basic criteria for the differential diagnosis of tumors and other lesions of the extrahepatic bile ducts. A comparative analysis of endosonography, ultrasound, CT, MRCP was conducted. The sensitivity of endosonography in determining the nature of the common bile duct stenosis was 97.7%, a specificity 100% and accuracy 98.2%, which is superior to other methods of radiological diagnosis. In comprehensive surgical centers endosonography should be used as a method of specifying the final diagnosis to determine the nature of the common bile duct stenosis, particularly at low constriction location.

Percutaneous rendezvous technique for the management of a bile duct injury.

Science.gov (United States)

Meek, James; Fletcher, Savannah; Crumley, Kristen; Culp, W C; Meek, Mary

2018-02-01

The rendezvous technique typically involves combined efforts of interventional radiology, endoscopy, and surgery. It can be done solely percutaneously, whereby the interventionalist gains desired access to one point in the body by approaching it from two different access sites. We present the case of a woman who underwent cholecystectomy complicated by a bile duct injury. A percutaneous rendezvous procedure enabled placement of an internal-external drain from the intrahepatic ducts through the biloma and distal common bile duct and into the duodenum. Thus, a percutaneous rendezvous technique is feasible for managing a bile duct injury when endoscopic retrograde cholangio-pancreatography or percutaneous transhepatic cholangiogram alone has been unsuccessful.

Percutaneous rendezvous technique for the management of a bile duct injury

Directory of Open Access Journals (Sweden)

James Meek, DO

2018-02-01

Full Text Available The rendezvous technique typically involves combined efforts of interventional radiology, endoscopy, and surgery. It can be done solely percutaneously, whereby the interventionalist gains desired access to one point in the body by approaching it from two different access sites. We present the case of a woman who underwent cholecystectomy complicated by a bile duct injury. A percutaneous rendezvous procedure enabled placement of an internal-external drain from the intrahepatic ducts through the biloma and distal common bile duct and into the duodenum. Thus, a percutaneous rendezvous technique is feasible for managing a bile duct injury when endoscopic retrograde cholangio-pancreatography or percutaneous transhepatic cholangiogram alone has been unsuccessful.

Status of the development of hot gas ducts for HTRs

International Nuclear Information System (INIS)

Stehle, H.; Klas, E.

1984-01-01

In the PNP nuclear process heat system the heat generated in the helium cooled core is transferred to the steam reformer and to the successive steam generator or to the intermediate heat exchanger by the primary helium via suitable hot gas ducts. The heat is carried over to the steam gasifier by the intermediate heat exchanger and a secondary helium loop. In both the primary and the secondary loop, the hot gas ducts are internally insulated by a ceramic fibre insulation to protect the support tube and the pressure housing from the high helium temperatures. A graphite hot gas liner will be used for the coaxial primary duct with an annular gap between support tube and pressure shell for the cold gas counterflow. A metallic hot gas liner will be installed in the secondary duct

Locating and Quantifying Broadband Fan Sources Using In-Duct Microphones

Science.gov (United States)

Dougherty, Robert P.; Walker, Bruce E.; Sutliff, Daniel L.

2010-01-01

In-duct beamforming techniques have been developed for locating broadband noise sources on a low-speed fan and quantifying the acoustic power in the inlet and aft fan ducts. The NASA Glenn Research Center's Advanced Noise Control Fan was used as a test bed. Several of the blades were modified to provide a broadband source to evaluate the efficacy of the in-duct beamforming technique. Phased arrays consisting of rings and line arrays of microphones were employed. For the imaging, the data were mathematically resampled in the frame of reference of the rotating fan. For both the imaging and power measurement steps, array steering vectors were computed using annular duct modal expansions, selected subsets of the cross spectral matrix elements were used, and the DAMAS and CLEAN-SC deconvolution algorithms were applied.

Sound

CERN Document Server

Robertson, William C

2003-01-01

Muddled about what makes music? Stuck on the study of harmonics? Dumbfounded by how sound gets around? Now you no longer have to struggle to teach concepts you really don t grasp yourself. Sound takes an intentionally light touch to help out all those adults science teachers, parents wanting to help with homework, home-schoolers seeking necessary scientific background to teach middle school physics with confidence. The book introduces sound waves and uses that model to explain sound-related occurrences. Starting with the basics of what causes sound and how it travels, you'll learn how musical instruments work, how sound waves add and subtract, how the human ear works, and even why you can sound like a Munchkin when you inhale helium. Sound is the fourth book in the award-winning Stop Faking It! Series, published by NSTA Press. Like the other popular volumes, it is written by irreverent educator Bill Robertson, who offers this Sound recommendation: One of the coolest activities is whacking a spinning metal rod...

Thermionic nuclear reactor with internal heat distribution and multiple duct cooling

Science.gov (United States)

Fisher, C.R.; Perry, L.W. Jr.

1975-11-01

A Thermionic Nuclear Reactor is described having multiple ribbon-like coolant ducts passing through the core, intertwined among the thermionic fuel elements to provide independent cooling paths. Heat pipes are disposed in the core between and adjacent to the thermionic fuel elements and the ribbon ducting, for the purpose of more uniformly distributing the heat of fission among the thermionic fuel elements and the ducts.

CASE REPORTS Thyroglossal duct cyst in adult Nigerians: a report ...

African Journals Online (AJOL)

MacBook

Thyroglossal duct cyst (TGDC) is the most common paediatric midline neck lesion. It is rare ... modified Sistrunk's operation and histology confirmed the diagnosis of thyroglossal cyst. ... surgical procedure for the treatment of thyroglossal duct ...

The songs of Tlaloc: Interference of ten ceramical duct flutes, Offering 89 of the Aztec Templo Mayor

Science.gov (United States)

Both, M. A. Adje

2002-11-01

Among the many preserved sound artefacts deposited in the offerings of the Aztec Templo Mayor are a set of ten tubular duct flutes made from clay, dating Late Postclassic Mesoamerica, 1350-1521 AD. The aerophones are completely painted in blue, and characterized by: (1) a short mouthpiece; (2) a framed aperture; (3) a tube with four fingerholes; and (4) an applicated mask with features of the Aztec rain god Tlaloc, basically three rings and a standardized relief structure of two clouds. While all measurements follow the same pattern, one particular organological distinction was made, as five flutes show an exit hole in the middle ring of the mask and five flutes are stopped. Thus, five instruments sound considerably higher, apart from the minimal pitch deviation of each specimen. Both the tonal capacity of each flute and the acoustics of several flutes played simultaneously were recorded and measured. A series of remarkable interference effects could be produced, which were strongly related to the ritual complex reflected in the offering. Taking in consideration the Aztec concept of music, it could be supposed that they were perceived as a principle of the song, or proper voice of Tlaloc.

Coupling Numerical Methods and Analytical Models for Ducted Turbines to Evaluate Designs

Directory of Open Access Journals (Sweden)

Bradford Knight

2018-04-01

Full Text Available Hydrokinetic turbines extract energy from currents in oceans, rivers, and streams. Ducts can be used to accelerate the flow across the turbine to improve performance. The objective of this work is to couple an analytical model with a Reynolds averaged Navier–Stokes (RANS computational fluid dynamics (CFD solver to evaluate designs. An analytical model is derived for ducted turbines. A steady-state moving reference frame solver is used to analyze both the freestream and ducted turbine. A sliding mesh solver is examined for the freestream turbine. An efficient duct is introduced to accelerate the flow at the turbine. Since the turbine is optimized for operation in the freestream and not within the duct, there is a decrease in efficiency due to duct-turbine interaction. Despite the decrease in efficiency, the power extracted by the turbine is increased. The analytical model under-predicts the flow rejection from the duct that is predicted by CFD since the CFD predicts separation but the analytical model does not. Once the mass flow rate is corrected, the model can be used as a design tool to evaluate how the turbine-duct pair reduces mass flow efficiency. To better understand this phenomenon, the turbine is also analyzed within a tube with the analytical model and CFD. The analytical model shows that the duct’s mass flow efficiency reduces as a function of loading, showing that the system will be more efficient when lightly loaded. Using the conclusions of the analytical model, a more efficient ducted turbine system is designed. The turbine is pitched more heavily and the twist profile is adapted to the radial throat velocity profile.

Characterization of the secondary flow in hexagonal ducts

Science.gov (United States)

Marin, O.; Vinuesa, R.; Obabko, A. V.; Schlatter, P.

2016-12-01

In this work we report the results of DNSs and LESs of the turbulent flow through hexagonal ducts at friction Reynolds numbers based on centerplane wall shear and duct half-height Reτ,c ≃ 180, 360, and 550. The evolution of the Fanning friction factor f with Re is in very good agreement with experimental measurements. A significant disagreement between the DNS and previous RANS simulations was found in the prediction of the in-plane velocity, and is explained through the inability of the RANS model to properly reproduce the secondary flow present in the hexagon. The kinetic energy of the secondary flow integrated over the cross-sectional area yz decreases with Re in the hexagon, whereas it remains constant with Re in square ducts at comparable Reynolds numbers. Close connection between the values of Reynolds stress u w ¯ on the horizontal wall close to the corner and the interaction of bursting events between the horizontal and inclined walls is found. This interaction leads to the formation of the secondary flow, and is less frequent in the hexagon as Re increases due to the 120∘ aperture of its vertex, whereas in the square duct the 90∘ corner leads to the same level of interaction with increasing Re. Analysis of turbulence statistics at the centerplane and the azimuthal variance of the mean flow and the fluctuations shows a close connection between hexagonal ducts and pipe flows, since the hexagon exhibits near-axisymmetric conditions up to a distance of around 0.15DH measured from its center. Spanwise distributions of wall-shear stress show that in square ducts the 90∘ corner sets the location of a high-speed streak at a distance zv+≃50 from it, whereas in hexagons the 120∘ aperture leads to a shorter distance of zv+≃38 . At these locations the root mean square of the wall-shear stresses exhibits an inflection point, which further shows the connections between the near-wall structures and the large-scale motions in the outer flow.

New strategy for treatment of carcinoma of the hilar bile duct

International Nuclear Information System (INIS)

Koyama, K.; Tanaka, J.; Kato, S.; Asanuma, Y.

1989-01-01

Surgical treatment for carcinoma of the hilar bile duct has been a challenging problem, because the five year survival rate is less than 5 per cent and the mean survival period is 17 to 24 months even in curatively resected instances. The prognostic factors of carcinoma of the hilar bile duct are remnant carcinoma at the bile duct stump and cancerous invasion into the lymphatics, veins, perineural spaces around the intrahepatic bile duct and caudate lobe of the liver. Based on these data, a new strategy for treatment of carcinoma of the hilar bile duct has been developed and applied clinically. The strategy consists of three procedures. The first is resection of the hilar bile duct with portajejunostomy; the second, specific anticancer therapy with mitomycin C (4 milligrams) adsorbed to the activated charcoal (MMC-CH) focused on the invasion of carcinoma to the periductal lymphatics, and third, intracavitary irradiation (32 to 40 gray) by 60Co using the remote after loading system through the bile duct focused on the periductal infiltration of the carcinoma and through the inferior vena cava focused on the caudate lobe of the liver. In this article, the operative procedures and theoretic background of the specific chemotherapy and irradiation are described. Seven patients have been treated using this regimen. Follow-up study ranged from seven to 38 months. All patients are alive, and five of seven are disease-free

Experimental implementation of a low-frequency global sound equalization method based on free field propagation

DEFF Research Database (Denmark)

Santillan, Arturo Orozco; Pedersen, Christian Sejer; Lydolf, Morten

2007-01-01

An experimental implementation of a global sound equalization method in a rectangular room using active control is described in this paper. The main purpose of the work has been to provide experimental evidence that sound can be equalized in a continuous three-dimensional region, the listening zone......, which occupies a considerable part of the complete volume of the room. The equalization method, based on the simulation of a progressive plane wave, was implemented in a room with inner dimensions of 2.70 m x 2.74 m x 2.40 m. With this method,the sound was reproduced by a matrix of 4 x 5 loudspeakers...... in one of the walls. After traveling through the room, the sound wave was absorbed on the opposite wall, which had a similar arrangement of loudspeakers, by means of active control. A set of 40 digital FIR filters was used to modify the original input signal before it was fed to the loudspeakers, one...

Navier-Stokes analysis and experimental data comparison of compressible flow within ducts

Science.gov (United States)

Harloff, G. J.; Reichert, B. A.; Sirbaugh, J. R.; Wellborn, S. R.

1992-01-01

Many aircraft employ ducts with centerline curvature or changing cross-sectional shape to join the engine with inlet and exhaust components. S-ducts convey air to the engine compressor from the intake and often decelerate the flow to achieve an acceptable Mach number at the engine compressor by increasing the cross-sectional area downstream. Circular-to-rectangular transition ducts are used on aircraft with rectangular exhaust nozzles to connect the engine and nozzle. To achieve maximum engine performance, the ducts should minimize flow total pressure loss and total pressure distortion at the duct exit. Changes in the curvature of the duct centerline or the duct cross-sectional shape give rise to streamline curvature which causes cross stream pressure gradients. Secondary flows can be caused by deflection of the transverse vorticity component of the boundary layer. This vortex tilting results in counter-rotating vortices. Additionally, the adverse streamwise pressure gradient caused by increasing cross-sectional area can lead to flow separation. Vortex pairs have been observed in the exit planes of both duct types. These vortices are due to secondary flows induced by pressure gradients resulting from streamline curvature. Regions of low total pressure are produced when the vortices convect boundary layer fluid into the main flow. The purpose of the present study is to predict the measured flow field in a diffusing S-duct and a circular-to-rectangular transition duct with a full Navier-Stokes computer program, PARC3D, and to compare the numerical predictions with new detailed experimental measurements. The work was undertaken to extend previous studies and to provide additional CFD validation data needed to help model flows with strong secondary flow and boundary layer separation. The S-duct computation extends the study of Smith et al, and Harloff et al, which concluded that the computation might be improved by using a finer grid and more advanced turbulence models

Causes and Prevention of Laparoscopic Bile Duct Injuries

Science.gov (United States)

Way, Lawrence W.; Stewart, Lygia; Gantert, Walter; Liu, Kingsway; Lee, Crystine M.; Whang, Karen; Hunter, John G.

2003-01-01

Objective To apply human performance concepts in an attempt to understand the causes of and prevent laparoscopic bile duct injury. Summary Background Data Powerful conceptual advances have been made in understanding the nature and limits of human performance. Applying these findings in high-risk activities, such as commercial aviation, has allowed the work environment to be restructured to substantially reduce human error. Methods The authors analyzed 252 laparoscopic bile duct injuries according to the principles of the cognitive science of visual perception, judgment, and human error. The injury distribution was class I, 7%; class II, 22%; class III, 61%; and class IV, 10%. The data included operative radiographs, clinical records, and 22 videotapes of original operations. Results The primary cause of error in 97% of cases was a visual perceptual illusion. Faults in technical skill were present in only 3% of injuries. Knowledge and judgment errors were contributory but not primary. Sixty-four injuries (25%) were recognized at the index operation; the surgeon identified the problem early enough to limit the injury in only 15 (6%). In class III injuries the common duct, erroneously believed to be the cystic duct, was deliberately cut. This stemmed from an illusion of object form due to a specific uncommon configuration of the structures and the heuristic nature (unconscious assumptions) of human visual perception. The videotapes showed the persuasiveness of the illusion, and many operative reports described the operation as routine. Class II injuries resulted from a dissection too close to the common hepatic duct. Fundamentally an illusion, it was contributed to in some instances by working too deep in the triangle of Calot. Conclusions These data show that errors leading to laparoscopic bile duct injuries stem principally from misperception, not errors of skill, knowledge, or judgment. The misperception was so compelling that in most cases the surgeon did not

Chloride and potassium conductances of cultured human sweat ducts

DEFF Research Database (Denmark)

Novak, I; Pedersen, P S; Larsen, Erik Hviid

1992-01-01

The purpose of this study was to characterize the ion conductances, in particular those for Cl- and K+, of human sweat duct cells grown in primary culture. Sweat duct cells from healthy individuals were grown to confluence on a dialysis membrane, which was then mounted in a mini-Ussing chamber an...

Erlotinib in Treating Patients With Unresectable Liver, Bile Duct, or Gallbladder Cancer

Science.gov (United States)

2013-06-03

Adult Primary Cholangiocellular Carcinoma; Adult Primary Hepatocellular Carcinoma; Advanced Adult Primary Liver Cancer; Cholangiocarcinoma of the Extrahepatic Bile Duct; Cholangiocarcinoma of the Gallbladder; Localized Unresectable Adult Primary Liver Cancer; Recurrent Adult Primary Liver Cancer; Recurrent Extrahepatic Bile Duct Cancer; Recurrent Gallbladder Cancer; Unresectable Extrahepatic Bile Duct Cancer; Unresectable Gallbladder Cancer

Liver segment IV hypoplasia as a risk factor for bile duct injury.

Science.gov (United States)

Mercado, Miguel Angel; Franssen, Bernardo; Arriola, Juan Carlos; Garcia-Badiola, Artemio; Arámburo, Rigoberto; Elnecavé, Alejandro; Cortés-González, Rubén

2011-09-01

Bile duct injury remains constant in the era of laparoscopic cholecystectomy and misidentification of structures remains one of the most common causes of such injuries. Abnormalities in liver segment IV, which is fully visible during laparoscopic cholecystectomy, may contribute to misidentification as proposed herein. We describe the case of a 36-year-old female who had a bile duct injury during a laparoscopic cholecystectomy where the surgeon noticed an unusually small distance between the gallbladder and the round ligament. We define hypoplasia of liver segment IV as well as describe the variation of the biliary anatomy in the case. We also intend to fit it in a broader spectrum of developmental anomalies that have both hyopoplasia of some portion of the liver and variations in gallbladder and bile duct anatomy that may contribute to bile duct injury. To our knowledge, hypoplasia of liver segment IV has not been suggested in the literature as a risk factor for bile duct injury except in the extreme case of a left-sided gallbladder. Surgeons should be vigilant during laparoscopic cholecystectomy when they become aware of an unusually small distance between the gallbladder bed and the round ligament prior to beginning their dissection, variations in the common bile duct and cystic duct should be expected.

Absorbing Property of Multi-layered Short Carbon Fiber Absorbing Coating

OpenAIRE

Liu, Zhaohui; Tao, Rui; Ban, Guodong; Luo, Ping

2018-01-01

The radar absorbing coating was prepared with short carbon fiber asabsorbent and waterborne polyurethane (WPU) as matrix resin. The coating’s absorbing property was tested with vectornetwork analyzer, using aramid honeycomb as air layer which was matched withcarbon fiber coating. The results demonstrate that the single-layered carbonfiber absorbing coating presented relatively poor absorbing property when thelayer was thin, and the performance was slightly improved after the matched airlayer ...

Ducted whistler-mode signals received at two widely spaced locations

Directory of Open Access Journals (Sweden)

M. A. Clilverd

Full Text Available Whistler-mode signals from a single VLF transmitter that have propagated in the same duct, have been observed simultaneously at Faraday, Antarctica (65°S, 64°W and Dunedin, New Zealand (46°S, 171°E. The signals received have group-delay times that differ in the order of 10 ms, which can be explained by the differences in southern-hemisphere sub-ionospheric propagation time from duct exit region to receiver for the two sites. This difference has been used to determine the location of the duct exit region, with confirmation provided by arrival-bearing information from both sites. The whistler-mode signals typically occur one or two days after geomagnetic activity, with K_pgeq5. The sub-ionospheric-propagation model, LWPC, is used to estimate the whistler-mode power radiated from the duct exit region. These results are then combined with estimated loss values for ionospheric and ducted transmission to investigate the role of wave-particle amplification or absorption. On at least half of the events studied, plasmaspheric amplification of the signals appears to be needed to explain the observed whistler-mode signal strengths.

Ducted whistler-mode signals received at two widely spaced locations

Directory of Open Access Journals (Sweden)

M. A. Clilverd

1996-06-01

Full Text Available Whistler-mode signals from a single VLF transmitter that have propagated in the same duct, have been observed simultaneously at Faraday, Antarctica (65°S, 64°W and Dunedin, New Zealand (46°S, 171°E. The signals received have group-delay times that differ in the order of 10 ms, which can be explained by the differences in southern-hemisphere sub-ionospheric propagation time from duct exit region to receiver for the two sites. This difference has been used to determine the location of the duct exit region, with confirmation provided by arrival-bearing information from both sites. The whistler-mode signals typically occur one or two days after geomagnetic activity, with Kp\\geq5. The sub-ionospheric-propagation model, LWPC, is used to estimate the whistler-mode power radiated from the duct exit region. These results are then combined with estimated loss values for ionospheric and ducted transmission to investigate the role of wave-particle amplification or absorption. On at least half of the events studied, plasmaspheric amplification of the signals appears to be needed to explain the observed whistler-mode signal strengths.

Ducted electromagnetic waves in the Martian ionosphere detected by the Mars Advanced Radar for Subsurface and Ionosphere Sounding radar

Science.gov (United States)

Zhang, Zhenfei; Orosei, Roberto; Huang, Qian; Zhang, Jie

2016-07-01

In the data of the Mars Advanced Radar for Subsurface and Ionosphere Sounding on board the European Space Agency (ESA) mission Mars Express (MEX), a distinctive type of signals (called the "epsilon signature"), which is similar to that previously detected during radio sounding of the terrestrial F region ionosphere, is found. The signature is interpreted to originate from multiple reflections of electromagnetic waves propagating along sounder pulse-created, crustal magnetic field-aligned plasma bubbles (waveguides). The signatures have a low (below 0.5%) occurrence rate and apparent cutoff frequencies 3-5 times higher than the theoretical one for an ordinary mode wave. These properties are explained by the influence of the perpendicular ionospheric plasma density gradient and the sounder pulse frequency on the formation of waveguides.

Importance of resin ducts in reducing ponderosa pine mortality from bark beetle attack.

Science.gov (United States)

Kane, Jeffrey M; Kolb, Thomas E

2010-11-01

The relative importance of growth and defense to tree mortality during drought and bark beetle attacks is poorly understood. We addressed this issue by comparing growth and defense characteristics between 25 pairs of ponderosa pine (Pinus ponderosa) trees that survived and trees that died from drought-associated bark beetle attacks in forests of northern Arizona, USA. The three major findings of our research were: (1) xylem resin ducts in live trees were >10% larger (diameter), >25% denser (no. of resin ducts mm(-2)), and composed >50% more area per unit ring growth than dead trees; (2) measures of defense, such as resin duct production (no. of resin ducts year(-1)) and the proportion of xylem ring area to resin ducts, not growth, were the best model parameters of ponderosa pine mortality; and (3) most correlations between annual variation in growth and resin duct characteristics were positive suggesting that conditions conducive to growth also increase resin duct production. Our results suggest that trees that survive drought and subsequent bark beetle attacks invest more carbon in resin defense than trees that die, and that carbon allocation to resin ducts is a more important determinant of tree mortality than allocation to radial growth.

Hepaticocystic duct and a rare extra-hepatic "cruciate" arterial anastomosis: a case report

Directory of Open Access Journals (Sweden)

Abeysuriya Vasitha

2008-02-01

Full Text Available Abstract Introduction The variations in the morphological characteristics of the extra-hepatic biliary system are interesting. Case presentation During the dissection of cadavers to study the morphological characteristics of the extra-hepatic biliary system, a 46-year-old male cadaver was found to have drainage of the common hepatic duct drains directly into the gall bladder neck. The right and left hepatic ducts were not seen extra-hepatically. Further drainage of the bile away from the gallbladder and into the duodenum was provided by the cystic duct. Formation of the common bile duct by the union of the common hepatic duct and cystic duct was absent. Further more the right hepatic artery was found to be communicating with the left hepatic artery by a "bridging artery" after giving rise to the cystic artery. An accessory hepatic artery originated from the "bridging artery" forming a "cruciate" hepatic arterial anastomosis. Conclusion Combination of a Hepaticocystic duct and an aberrant variation in the extra-hepatic arterial system is extremely rare.

Surgical versus endoscopic treatment of bile duct stones

DEFF Research Database (Denmark)

Martin, D J; Vernon, D R; Toouli, J

2006-01-01

10% to 18% of patients undergoing cholecystectomy for gallstones have common bile duct (CBD) stones. Treatment options for these stones include pre- or post-operative endoscopic retrograde cholangiopancreatography (ERCP) or open or laparoscopic surgery.......10% to 18% of patients undergoing cholecystectomy for gallstones have common bile duct (CBD) stones. Treatment options for these stones include pre- or post-operative endoscopic retrograde cholangiopancreatography (ERCP) or open or laparoscopic surgery....

Effects of partial portal vein arterialization on the hilar bile duct in a rat model.

Science.gov (United States)

Guo, Shao-Hua; Li, Chong-Hui; Chen, Yong-Liang; Song, Jian-Ning; Zhang, Ai-Qun; Zhou, Cheng

2011-10-01

Liver revascularization is frequently required during the enlarged radical operation for hilar cholangiocarcinoma involving the hepatic artery. Researchers have carried out a number of experiments applying partial portal vein arterialization (PVA) in clinical practice. In this study we aimed to establish a theoretical basis for clinical application of partial PVA and to investigate the effects of partial PVA on rat hilar bile duct and hepatic functions. Thirty rats were randomly and equally assigned into 3 groups: control (group A), hepatic artery ligation+bile duct recanalization (group B), and partial PVA+bile duct recanalization (group C). Proliferation and apoptosis of rat hilar bile duct epithelial cells, arteriolar counts of the peribiliary plexus (PBP) of the bile duct wall, changes in serum biochemistry, and pathologic changes in the bile duct were assessed 1 month after operation. The proliferation of hilar bile duct epithelial cells in group B was greater than in groups A and C (Philar bile duct epithelial cells were detected in any of the groups. The PBP arteriolar counts of the hilar bile duct wall were similar in groups A and C (P>0.05), but the count was lower in group B than in group A (Philar bile duct walls were observed only in group B. Partial PVA can restore the arterial blood supply of the hilar bile duct and significantly extenuate the injury to hilar bile duct epithelial cells resulting from hepatic artery ligation.

Numerically-based ducted propeller design using vortex lattice lifting line theory

OpenAIRE

Stubblefield, John M.

2008-01-01

CIVINS (Civilian Institutions) Thesis document This thesis used vortex lattice lifting line theory to model an axisymmetrical-ducted propeller with no gap between the duct and the propeller. The theory required to model the duct and its interaction with the propeller were discussed and implemented in Open-source Propeller Design and Analysis Program (OpenProp). Two routines for determining the optimum circulation distribution were considered, and a method based on calculus of variation...

[Persistence of the omphalomesenteric duct. Childhood differential diagnosis of umbilical granuloma].

Science.gov (United States)

Sánchez-Castellanos, M E; Sandoval-Tress, C; Hernández-Torres, M

2006-01-01

The omphalomesenteric duct is an embryonic structure which communicates the vitelline duct with the midgut. It normally disappears between the fifth and ninth weeks of intrauterine life. Anomalies related with the total or partial absence of this involution are show in 2 % of the population. We report a case of persistence of the omphalomesenteric duct and review the bibliography to establish the differences between this anomaly and umbilical granuloma, which is the main differential diagnosis.

Building America Case Study: High-Velocity Small-Diameter Duct System, Pittsburgh, Pennsylvania

Energy Technology Data Exchange (ETDEWEB)

2017-04-01

This study tests the performance of a variable airflow small-diameter duct heating, ventilation, and air conditioning (HVAC) system in a new construction unoccupied low-load test house in Pittsburgh, Pennsylvania. The duct system was installed entirely in conditioned space and was operated from the winter through summer seasons. Measurements were collected on the in-room temperatures and energy consumed by the air handler and heat pump unit. Operation modes with three different volumes of airflow were compared to determine the ideal airflow scenario that maximizes room-to-room thermal uniformity while minimizing fan energy consumption. Black felt infrared imagery was used as a measure of diffuser throw and in-room air mixing. Measured results indicate the small-diameter, high velocity airflow system can provide comfort under some conditions. Solar heat gains resulted in southern rooms drifting beyond acceptable temperature limits. Insufficient airflow to some bedrooms also resulted in periods of potential discomfort. Homebuilders or HVAC contractors can use these results to assess whether this space conditioning strategy is an attractive alternative to a traditional duct system. The team performed a cost analysis of two duct system configurations: (1) a conventional diameter and velocity duct system, and (2) the small-diameter duct system. This work applies to both new and retrofit homes that have achieved a low heating and cooling density either by energy conservation or by operation in a mild climate with few heating or cooling degree days. Guidance is provided on cost trade-offs between the conventional duct system and the small-diameter duct system.

Autoimmune pancreatitis: Assessment of the enhanced duct sign on multiphase contrast-enhanced computed tomography

International Nuclear Information System (INIS)

Kawai, Yuichi; Suzuki, Kojiro; Itoh, Shigeki; Takada, Akira; Mori, Yoshine; Naganawa, Shinji

2012-01-01

Purpose: To assess the usefulness of the computed tomography (CT) finding of main pancreatic duct (MPD) wall enhancement, termed the “enhanced duct sign”, for diagnosis of autoimmune pancreatitis (AIP) in comparison with diagnosis of pancreatic carcinoma and chronic pancreatitis. Materials and methods: Two radiologists independently evaluated the presence or absence of the enhanced duct sign on multiphase contrast-enhanced CT in patients with AIP (n = 55), pancreatic carcinoma (n = 50), and chronic pancreatitis (n = 50). The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of AIP were calculated. In patients demonstrating the enhanced duct sign, additional findings were evaluated by consensus. Results: The enhanced duct sign was more frequently observed in patients with AIP (37/55, 67%) than in patients with pancreatic carcinoma (5/50, 10%) or chronic pancreatitis (0/50, 0%) (P < 0.05). The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the finding were 0.67, 0.95, 0.85, 0.88, and 0.84, respectively. In AIP, the lumen within the enhanced duct was completely or partially invisible in 29 of 37 (78%) patients, and the enhanced duct was observed within the affected pancreatic parenchyma in 35 of 37 (95%) patients. In pancreatic carcinoma, the lumen within the enhanced duct was visible in all patients (5/5, 100%), and the enhanced duct was observed downstream of the tumor (5/5, 100%). Conclusion: The enhanced duct sign is highly specific of AIP.

Autoimmune pancreatitis: Assessment of the enhanced duct sign on multiphase contrast-enhanced computed tomography

Energy Technology Data Exchange (ETDEWEB)

Kawai, Yuichi, E-mail: kawai.yuichi@a.mbox.nagoya-u.ac.jp [Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan); Suzuki, Kojiro, E-mail: kojiro@med.nagoya-u.ac.jp [Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan); Itoh, Shigeki, E-mail: shigeito@nagoya-1st.jrc.or.jp [Department of Diagnostic Radiology, Japan Red Cross Nagoya Daiichi Hospital, 3-35 Michishita-cho, Nakamura-ku, Nagoya 453-8511 (Japan); Takada, Akira, E-mail: takadaa@med.nagoya-u.ac.jp [Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan); Mori, Yoshine, E-mail: yoshine@med.nagoya-u.ac.jp [Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan); Naganawa, Shinji, E-mail: naganawa@med.nagoya-u.ac.jp [Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan)

2012-11-15

Purpose: To assess the usefulness of the computed tomography (CT) finding of main pancreatic duct (MPD) wall enhancement, termed the 'enhanced duct sign', for diagnosis of autoimmune pancreatitis (AIP) in comparison with diagnosis of pancreatic carcinoma and chronic pancreatitis. Materials and methods: Two radiologists independently evaluated the presence or absence of the enhanced duct sign on multiphase contrast-enhanced CT in patients with AIP (n = 55), pancreatic carcinoma (n = 50), and chronic pancreatitis (n = 50). The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of AIP were calculated. In patients demonstrating the enhanced duct sign, additional findings were evaluated by consensus. Results: The enhanced duct sign was more frequently observed in patients with AIP (37/55, 67%) than in patients with pancreatic carcinoma (5/50, 10%) or chronic pancreatitis (0/50, 0%) (P < 0.05). The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the finding were 0.67, 0.95, 0.85, 0.88, and 0.84, respectively. In AIP, the lumen within the enhanced duct was completely or partially invisible in 29 of 37 (78%) patients, and the enhanced duct was observed within the affected pancreatic parenchyma in 35 of 37 (95%) patients. In pancreatic carcinoma, the lumen within the enhanced duct was visible in all patients (5/5, 100%), and the enhanced duct was observed downstream of the tumor (5/5, 100%). Conclusion: The enhanced duct sign is highly specific of AIP.

Clinical implications of bile duct injury after transcatheter arterial chemoembolization

International Nuclear Information System (INIS)

Wang Maoqiang; Tang Wenjie; Lin Hanying; Ye Huiyi; Dai Guanghai; Wang Zhiqiang

2005-01-01

Objective: To evaluate the incidence, risk factors , and clinical course of bile duct injury after transcatheter arterial chemoembolization (TACE) for treatment of hepatic malignancy. Methods: A total of 1240 consecutive patients with hepatic malignancies underwent 2680 TACE procedures. None of these patients were found to have any radiographic evidence of biliary abnormalities pre-TACE. Eighteen patients developed bile duct injuries at 3 weeks to 3 months after TACE. A retrospective review of medical records and imaging studies were carried out to evaluate the occurrence of TACE-induced bile duct injury, the clinical outcome, and the statistical significance of potential predisposing factors. Results: The TACE-induced bile duct injuries occurred in 13 of 148 patients with liver metastatic tumors (8.8%), 5 of 1092 patients with HCC (0.5%). Biliary injuries, including focal (n=4) and multiple intrahepatic bile duct dilatation (n=8), and cystic lesion or biloma (n=6), were identified on the follow-up imaging studies after TACE. Three patients with multiple bile duct injuries had mild jaundice at the presentation, two of them responded well to the conservative treatment, one died of irreversible deterioration of liver function at 2 weeks after the onset of jaundice. Four patients with a large biloma had associated serious bacterial infections; 3 of which were treated with percutaneous catheter drainage and antibiotics, 2 of them died of purulent peritonitis due to rupture of the cystic lesions and 1 cured with antibiotic. The remaining 11 patients were asymptomatic. The mortality related to the biliary injury occurred in 3 patients (16.7%). The incidences of bile duct injury were higher in patients with metastatic tumors in non-cirrhotic livers than in patients with hepatocellular carcinoma associated with cirrhosis (P<0.01), higher in patient with hypovascular lesions (P<0.01), and higher in patients using an emulsion of lipiodol-platinum for selective embolization

Duct corrosion in the ventilating air conditioning system for Main Control Room

International Nuclear Information System (INIS)

Yamada, Kohei; Kobayashi, Takashi; Minami, Akiko; Fukuba, Kazushi

2014-01-01

Higashidori Nuclear Power Station, start-of-operation in December 2005, is a relatively new plant. We decided to get original data of air duct condition to determine maintenance policy of air duct, because planned maintenance of air duct has never been done and the corrosion of air duct has occurred in other plant. In January 2014, we found a corrosion-hole at the downstream of the inlet damper in the ventilating air conditioning system for Main Control Room (MCR). We supposed that the cause of rapid corrosion is related to the characteristic environment of this site. (author)

Experiments on the Recovery of Waste Heat in Cooling Ducts, Special Report

Science.gov (United States)

Silverstein, Abe

1939-01-01

Tests have been conducted in the N.A.C.A. full-scale wind tunnel to investigate the partial recovery of the heat energy which is apparently wasted in the cooling of aircraft engines. The results indicate that if the radiator is located in an expanded duct, a part of the energy lost in cooling is recovered; however, the energy recovery is not of practical importance up to airplane speeds of 400 miles per hour. Throttling of the duct flow occurs with heated radiators and must be considered in designing the duct outlets from data obtained with cold radiators in the ducts.

Preventive maintenance plan of the air-conditioning duct using the ACM-sensor

International Nuclear Information System (INIS)

Fukuba, Kazushi; Ito, Takanobu; Kojima, Akiko; Tanji, Kazuhiro; Sato, Yuki

2013-01-01

Air-conditioning duct is difficult to predict the date to occur of corrosion such as affect the function. Therefore, the current conservation method is mostly corrective maintenance. Therefore, we used the test pieces of six types and ACM-sensor in order to solve the corrosion speed from corrosion environment and relationship of corrosion quantity of test pieces. In addition, was used the duct molded articles various in order to check the corrosion degree of when processed the duct. As a result, we were selected crust body constituting a duct and optimal combination of the flange by solve the corrosion speed of the test pieces various. Thus, it performs preventive disposal before to occur of corrosion such as affect the function by predicting the duct life from corrosion speed, and lead to stability and safe operating by appropriate maintenance of equipment. (author)

BETTER DUCT SYSTEMS FOR HOME HEATING AND COOLING.

Energy Technology Data Exchange (ETDEWEB)

ANDREWS,J.

2001-01-01

This is a series of six guides intended to provide a working knowledge of residential heating and cooling duct systems, an understanding of the major issues concerning efficiency, comfort, health, and safety, and practical tips on installation and repair of duct systems. These guides are intended for use by contractors, system designers, advanced technicians, and other HVAC professionals. The first two guides are also intended to be accessible to the general reader.

Embolization for Thoracic Duct Collateral Leakage in High-Output Chylothorax After Thoracic Surgery

International Nuclear Information System (INIS)

Kariya, Shuji; Nakatani, Miyuki; Yoshida, Rie; Ueno, Yutaka; Komemushi, Atsushi; Tanigawa, Noboru

2017-01-01

PurposeThis study was designed to investigate thoracic duct collateral leakage and the supply route of lymphatic fluid by lymphangiography and transcatheter thoracic ductography and to evaluate the results of embolization for thoracic duct collateral leakage performed to cut off this supply route.MethodsData were retrospectively collected from five patients who underwent embolization for thoracic duct collateral leakage in persistent high-output chylothorax after thoracic surgery. Extravasation of lipiodol at the ruptured thoracic duct collaterals was confirmed in all patients on lymphangiography. Transcatheter thoracic ductography was used to identify extravasation of iodinated contrast agent and to identify communication between the thoracic duct and leakage site. Thoracic duct embolization (TDE) was performed using the percutaneous transabdominal approach to cut off the supply route using N-butyl cyanoacrylate (NBCA) mixed with lipiodol (1:5–1:20).ResultsClinical success (drainage volume ≤10 mL/kg/day within 7 days after TDE) was achieved in all patients. The collateral routes developed as consequence of surgical thoracic duct ligation. In three patients, NBCA-Lipiodol reached the leakage site through direct communication between the thoracic duct and the ruptured lymphatic duct. In the other two patients, direct communication and extravasation was not detected on thoracic ductography, and NBCA-Lipiodol did not reach the leakage site. However, NBCA-Lipiodol did reach the cisterna chyli, lumbar trunks, and some collateral routes via the cisterna chyli or lumbar lymphatics. As a result, leakage was stopped.ConclusionsTDE was effective for the management of leakage of the collaterals in high-output chylothorax after thoracic surgery.

Embolization for Thoracic Duct Collateral Leakage in High-Output Chylothorax After Thoracic Surgery

Energy Technology Data Exchange (ETDEWEB)

Kariya, Shuji, E-mail: kariyas@hirakata.kmu.ac.jp; Nakatani, Miyuki, E-mail: nakatanm@hirakata.kmu.ac.jp; Yoshida, Rie, E-mail: yagir@hirakata.kmu.ac.jp; Ueno, Yutaka, E-mail: uenoyut@hirakata.kmu.ac.jp; Komemushi, Atsushi, E-mail: komemush@takii.kmu.ac.jp; Tanigawa, Noboru, E-mail: tanigano@hirakata.kmu.ac.jp [Kansai Medical University, Department of Radiology (Japan)

2017-01-15

PurposeThis study was designed to investigate thoracic duct collateral leakage and the supply route of lymphatic fluid by lymphangiography and transcatheter thoracic ductography and to evaluate the results of embolization for thoracic duct collateral leakage performed to cut off this supply route.MethodsData were retrospectively collected from five patients who underwent embolization for thoracic duct collateral leakage in persistent high-output chylothorax after thoracic surgery. Extravasation of lipiodol at the ruptured thoracic duct collaterals was confirmed in all patients on lymphangiography. Transcatheter thoracic ductography was used to identify extravasation of iodinated contrast agent and to identify communication between the thoracic duct and leakage site. Thoracic duct embolization (TDE) was performed using the percutaneous transabdominal approach to cut off the supply route using N-butyl cyanoacrylate (NBCA) mixed with lipiodol (1:5–1:20).ResultsClinical success (drainage volume ≤10 mL/kg/day within 7 days after TDE) was achieved in all patients. The collateral routes developed as consequence of surgical thoracic duct ligation. In three patients, NBCA-Lipiodol reached the leakage site through direct communication between the thoracic duct and the ruptured lymphatic duct. In the other two patients, direct communication and extravasation was not detected on thoracic ductography, and NBCA-Lipiodol did not reach the leakage site. However, NBCA-Lipiodol did reach the cisterna chyli, lumbar trunks, and some collateral routes via the cisterna chyli or lumbar lymphatics. As a result, leakage was stopped.ConclusionsTDE was effective for the management of leakage of the collaterals in high-output chylothorax after thoracic surgery.

Usefulness of the rendezvous technique for biliary stricture after adult right-lobe living-donor liver transplantation with duct-to-duct anastomosis.

Science.gov (United States)

Chang, Jae Hyuck; Lee, In Seok; Chun, Ho Jong; Choi, Jong Young; Yoon, Seung Kyoo; Kim, Dong Goo; You, Young Kyoung; Choi, Myung-Gyu; Choi, Kyu-Yong; Chung, In-Sik

2010-03-01

Replacement of a percutaneous transhepatic biliary drainage (PTBD) catheter with inside stents using endoscopic retrograde cholangiography is difficult in patients with angulated or twisted biliary anastomotic stricture after living donor liver transplantation (LDLT). We evaluated the usefulness and safety of the rendezvous technique for the management of biliary stricture after LDLT. Twenty patients with PTBD because of biliary stricture after LDLT with duct-to-duct anastomosis underwent the placement of inside stents using the rendezvous technique. Inside stents were successfully placed in the 20 patients using the rendezvous technique. The median procedure time was 29.6 (range, 7.5-71.8) minutes. The number of inside stents placed was one in 12 patients and two in eight patients. One mild acute pancreatitis and one acute cholangitis occurred, which improved within a few days. Inside stent related sludge or stone was identified in 12 patients during follow-up. Thirteen patients achieved stent-free status for a median of 281 (range, 70-1,351) days after removal of the inside stents. The rendezvous technique is a useful and safe method for the replacement of PTBD catheter with inside stent in patients with biliary stricture after LDLT with duct-to-duct anastomosis. The rendezvous technique could be recommended to patients with angulated or twisted strictures.

Assessment of Chronological Effects of Irreversible Electroporation on Hilar Bile Ducts in a Porcine Model

Energy Technology Data Exchange (ETDEWEB)

Choi, Jae Woong, E-mail: cooljay@korea.ac.kr; Lu, David S. K., E-mail: dlu@mednet.ucla.edu; Osuagwu, Ferdnand, E-mail: fosuagwu@mednet.ucla.edu; Raman, Steven, E-mail: sraman@mednet.ucla.edu [David Geffen School of Medicine at UCLA, Department of Radiology (United States); Lassman, Charles, E-mail: classman@mednet.ucla.edu [David Geffen School of Medicine at UCLA, Department of Pathology (United States)

2013-11-07

PurposeTo evaluate the chronological effects of irreversible electroporation (IRE) on large hilar bile ducts in an in vivo porcine model correlated with computed tomography (CT) cholangiography and histopathology.Materials and MethodsTwelve IRE zones were made along hilar bile ducts intraoperatively under ultrasound (US)-guidance in 11 pigs. Paired electrodes were placed either on opposing sides of the bile duct (straddle [STR]) or both on one side of the bile duct (one-sided [OSD]). The shortest electrode-to-duct distance was classified as periductal (≤2 mm) or nonperiductal (>2 mm). CT cholangiography and laboratory tests were performed before IRE and again at 2 days, 4 weeks, and 8 weeks after IRE. Degree of bile duct injury were graded as follows: grade 0 = no narrowing; grade 1 = ≤50 % duct narrowing; grade 2 = >50 % narrowing without proximal duct dilatation; grade 3 = grade 2 with proximal duct dilatation; and grade 4 = grade 3 with enzyme elevation. Pigs were selected for killing and histopathology at 2 days, 4, and 8 weeks.ResultsNonperiductal electrode placement produced no long-term strictures in 5 of 5 ducts. Periductal electrode placement produced mild narrowing in 6 of 7 ducts: 5 grade 1 and 1 grade 2. None showed increased enzymes. There was no significant difference between STR versus OSD electrode placement. Histopathology showed minor but relatively greater ductal mural changes in narrowed ducts.ConclusionIn the larger hilar ducts, long-term patency and mural integrity appear resistant to IRE damage with the energy deposition used, especially if the electrode is not immediately periductal in position.

Assessment of Chronological Effects of Irreversible Electroporation on Hilar Bile Ducts in a Porcine Model

International Nuclear Information System (INIS)

Choi, Jae Woong; Lu, David S. K.; Osuagwu, Ferdnand; Raman, Steven; Lassman, Charles

2014-01-01

PurposeTo evaluate the chronological effects of irreversible electroporation (IRE) on large hilar bile ducts in an in vivo porcine model correlated with computed tomography (CT) cholangiography and histopathology.Materials and MethodsTwelve IRE zones were made along hilar bile ducts intraoperatively under ultrasound (US)-guidance in 11 pigs. Paired electrodes were placed either on opposing sides of the bile duct (straddle [STR]) or both on one side of the bile duct (one-sided [OSD]). The shortest electrode-to-duct distance was classified as periductal (≤2 mm) or nonperiductal (>2 mm). CT cholangiography and laboratory tests were performed before IRE and again at 2 days, 4 weeks, and 8 weeks after IRE. Degree of bile duct injury were graded as follows: grade 0 = no narrowing; grade 1 = ≤50 % duct narrowing; grade 2 = >50 % narrowing without proximal duct dilatation; grade 3 = grade 2 with proximal duct dilatation; and grade 4 = grade 3 with enzyme elevation. Pigs were selected for killing and histopathology at 2 days, 4, and 8 weeks.ResultsNonperiductal electrode placement produced no long-term strictures in 5 of 5 ducts. Periductal electrode placement produced mild narrowing in 6 of 7 ducts: 5 grade 1 and 1 grade 2. None showed increased enzymes. There was no significant difference between STR versus OSD electrode placement. Histopathology showed minor but relatively greater ductal mural changes in narrowed ducts.ConclusionIn the larger hilar ducts, long-term patency and mural integrity appear resistant to IRE damage with the energy deposition used, especially if the electrode is not immediately periductal in position

Resin duct characteristics in the wood of fire-scarred North American conifers

Science.gov (United States)

Estelle Arbellay; Markus Stoffel; Elaine K. Sutherland; Kevin T. Smith; Donald A. Falk

2013-01-01

Traumatic resin ducts form in xylem and phloem tissue of conifers in response to abiotic wounding, fungal invasion, and insect attack. Little is known about resin duct characteristics in the wood of fire-scarred trees. The aim of this study is to quantify changes in traits of both axial and radial resin ducts, along with those of associated epithelial cells and...

Thoracic Duct Injury Following Cervical Spine Surgery: A Multicenter Retrospective Review.

Science.gov (United States)

Derakhshan, Adeeb; Lubelski, Daniel; Steinmetz, Michael P; Corriveau, Mark; Lee, Sungho; Pace, Jonathan R; Smith, Gabriel A; Gokaslan, Ziya; Bydon, Mohamad; Arnold, Paul M; Fehlings, Michael G; Riew, K Daniel; Mroz, Thomas E

2017-04-01

Multicenter retrospective case series. To determine the rate of thoracic duct injury during cervical spine operations. A retrospective case series study was conducted among 21 high-volume surgical centers to identify instances of thoracic duct injury during anterior cervical spine surgery. Staff at each center abstracted data for each identified case into case report forms. All case report forms were collected by the AOSpine North America Clinical Research Network Methodological Core for data processing, cleaning, and analysis. Of a total of 9591 patients reviewed that underwent cervical spine surgery, 2 (0.02%) incurred iatrogenic injury to the thoracic duct. Both patients underwent a left-sided anterior cervical discectomy and fusion. The interruption of the thoracic duct was addressed intraoperatively in one patient with no residual postoperative effects. The second individual developed a chylous fluid collection approximately 2 months after the operation that required drainage via needle aspiration. Damage to the thoracic duct during cervical spine surgery is a relatively rare occurrence. Rapid identification of the disruption of this lymphatic vessel is critical to minimize deleterious effects of this complication.

Techniques for cutting irradiated fuel ducts at FFTF/IEM cell

International Nuclear Information System (INIS)

Payzant, W.H.

1990-09-01

Two remotely controlled mill-type cutters have been used in the Fast Flux Test Facility Interim Examination and Maintenance Cell to assist in the disassembly of 18 fuel assemblies. These cutters slit the outer duct of the fuel assemblies, which allows the ducts to be removed and provides access to the encased fuel pins. The cutters were developed by Westinghouse Hanford Company and thoroughly tested by cutting prototypic ducts. During actual use, however, occasional loss of cutting depth control occurred. A discussion of the control problems and the operation and design techniques developed for their resolution is presented. 3 refs., 7 figs

Techniques for cutting irradiated fuel ducts at FFTF/IEM cell

International Nuclear Information System (INIS)

Payzant, W.H.

1991-01-01

Two remotely controlled mill-type cutters have been used in the Fast Flux Test Facility Interim Examination and Maintenance Cell to assist in the disassembly of 18 fuel assemblies. These cutters slit the outer duct of the fuel assemblies, which allows the ducts to be removed and provides access to the encased fuel pins. The cutters were developed by Westinghouse Hanford Company and thoroughly tested by cutting prototypic ducts. During actual use, however, occasional loss of cutting depth control occurred. A discussion of the control problems and the operation and design techniques developed for their resolution is presented in this paper

Roundness and straightness measurement of ceramic beam ducts for the 3 GeV-synchrotron

Energy Technology Data Exchange (ETDEWEB)

Nishizawa, Daiji; Kinsho, Michikazu; Kanazawa, Kenichiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Kubo, Tomio; Sato, Yoshihiro; Saito, Yoshio [High Energy Accelerator Research Organization, Tsukuba, Ibaraki (Japan)

2001-12-01

Large aperture ({phi}200 - {phi}250) cylindrical beam ducts consisting of alumina ceramics will be used in the 3 GeV-synchrotron of High Intensity Proton Accelerator Facility. In particular, bending magnet sections require the large length ({approx}3500 mm) ceramic beam duct connecting several unit ducts whose length is around 500-1000 mm by metallizing and glazing. Therefore it is very important to evaluate roundness and straightness of ceramic ducts because we have to compensate contact area large and have to minimize misalignment of ducts connected. We developed an apparatus for measuring roundness and straightness, and we completed data analysis method using general application software Excel as well as measuring method. Then we have taken data, and have evaluated value of roundness and straightness for the first time about 7 pieces (3 kinds) of ceramic beam duct. At last we have found out that unit ceramic ducts can be made after sintering without polishing with roundness several hundred micron ({mu}m) and straightness around 0.2-1 mm, and that straightness has a tendency to become large as duct length increases as well as roundness increases directly proportional to the maximum oblateness. (author)

Alumina Ceramics Vacuum Duct for the 3GeV-RCS of the J-PARC

CERN Document Server

Kinsho, Michikazu; Ogiwara, Norio; Saito, Yoshio

2005-01-01

It was success to develop alumina ceramics vacuum ducts for the 3GeV-RCS of J-PARC at JAERI. There are two types of alumina ceramics vacuum ducts needed, one being 1.5m-long duct with a circular cross section for use in the quadrupole magnet, the other being 3.5m-long and bending 15 degrees, with a race-track cross section for use in the dipole magnet. These ducts could be manufactured by joining several duct segments of 0.5-0.8 m in length by brazing. The alumina ceramics ducts have copper stripes on the outside surface of the ducts to reduce the duct impedance. One of the ends of each stripe is connected to a titanium flange by way of a capacitor so to interrupt an eddy current circuit. The copper stripes are produced by an electroforming method in which a stripe pattern formed by Mo-Mn metallization is first sintered on the exterior surface and then overlaid by PR-electroformed copper (Periodic current Reversal electroforming method). In order to reduce emission of secondary electrons when protons or elect...

Hinkley Point A gas duct repairs

International Nuclear Information System (INIS)

Curtis, R.F.

1996-01-01

In 1990, routine visual inspection of the Hinckley Point A Reactor 1 pressure vessel gas outlet ducts showed failures in the welded stud bolts retaining the insulation edging strips. Since the ducts are accessible only from within the pressure vessel, a remote repair technique that could be deployed via the vessel stand pipe had to be found. A drawn arc stud welding and work package formerly used at the Oldbury Power Station was modified for the purpose. The only manipulators with sufficient reach and adequate carrying capacity to deploy the package were the Sizewell SNAKES manipulators. One of these was modified to fit the Hinckley reactor and repairs have been successfully carried out. Similar studs on the gas ducts in Reactor 2, are shielded from visual inspection by a Z-clip feature. A technique using pulsed thermography was developed. The studs were heated for a short time at their exposed ends using a prefocused lamp and the heat decay patterns monitored by an infrared camera enabling attached and detached studs to be distinguished. The inspection package was deployed using the SNAKES manipulator again. In both operations, I-Grip computer modelling was used in the design of the package envelope and the deployment routes. (UK)

Experimental and Numerical Study on Performance of Ducted Hydrokinetic Turbines with Pre-Swirl Stator Blades.

Science.gov (United States)

Gish, Andrew

2015-11-01

Ducts (also called shrouds) have been shown to improve performance of hydrokinetic turbines in some situations, bringing the power coefficient (Cp) closer to the Betz limit. Here we investigate optimization of the duct design as well as the addition of stator blades upstream of the turbine rotor to introduce pre-swirl in the flow. A small scale three-bladed turbine was tested in a towing tank. Three cases (bare turbine, with duct, and with duct and stators) were tested over a range of flow speeds. Important parameters include duct cross-sectional shape, blade-duct gap, stator cross-sectional shape, and stator angle. For each test, Cp was evaluated as a function of tip speed ratio (TSR). Experimental results were compared with numerical simulations. Results indicate that ducts and stators can improve performance at slower flow speeds and lower the stall speed compared to a bare turbine, but may degrade performance at higher speeds. Ongoing efforts to optimize duct and stator configurations will be discussed.

Heat Pump Water Heater Ducting Strategies with Encapsulated Attics in Climate Zones 2 and 4

Energy Technology Data Exchange (ETDEWEB)

Sweet, M. L. [Southface Energy Inst., Upper Marlboro, MD (United States); Francisco, A.; Roberts, S. G.

2016-05-01

The focus of this study is on the performance of HPWHs with several different duct configurations and their effects on whole building heating, cooling, and moisture loads. A.O. Smith 60 gallon Voltex (PHPT-60) heat pump water heaters (HPWHs) were included at two project sites and ducted to or located within spray foamed encapsulated attics. The effect of ducting a HPWH's air stream does not diminish its efficiency if the ducting does not reduce intake air temperature, which expands HPWH application to confined areas. Exhaust ducts should be insulated to avoid condensation on the exterior, however this imposes a risk of condensation occurring in the duct's interior near the HPWH due to large variation of temperatures between the compressor and the duct and the presence of bulk moisture around the condenser. The HPWH's air conditioning impact on HVAC equipment loads is minimal when the intake and exhaust air streams are connected to a sealed attic and not the living space. A HPWH is not suitable as a replacement dehumidifier in sealed attics as peak moisture loads were observed to only be reduced if the heat pump operated during the morning. It appears that the intake air temperature and humidity was the most dominant variable affecting HPWH performance. Different ducting strategies such as exhaust duct only, intake duct only, and exhaust and intake ducting did not have any effect on HPWH performance.

Method of absorbing UF6 from gaseous mixtures in alkamine absorbents

International Nuclear Information System (INIS)

Lafferty, R.H.; Smiley, S.H.; Radimer, K.J.

1976-01-01

A method is described for recovering UF 6 from gaseous mixtures by absorption in a liquid. The liquid absorbent must have a relatively low viscosity and at least one component of the absorbent is an alkamine having less than 3 carbon atoms bonded to the amino nitrogen, less than 2 of the carbon atoms other than those bonded to the amino nitrogen are free of the hydroxy radical and precipitate the absorbed uranium from the absorbent. At least one component of the absorbent is chosen from the group consisting of ethanolamine, diethanolamine, and 3-methyl-3-amino-propane-diol-1,2

Involvement of the thoracic duct in liver cirrhosis patients with ascites. Using MR lymphography

International Nuclear Information System (INIS)

Kuboyama, Shin-ichi; Ishii, Kunihide; Koga, Hiroyuki

2003-01-01

To elucidate whether the morphological changes of the thoracic duct are observed in patients with liver cirrhosis and ascites, the thoracic duct was examined at magnetic resonance (MR) lymphography without contrast agent. In 7 healthy volunteers, the thoracic duct was clearly visualized as an intermittent or continuous straight line along the thoracic aorta (its mean diameter was 3.9 mm). In 20 liver cirrhosis without ascites, its mean diameter was 3.6 mm. In 6 liver cirrhosis with refractory ascites, the thoracic duct was visualized as straight or slightly tortuous and slender line (its mean diameter was 2.5 mm). On the other hand, 7 cases with ascites which respond well to the administration of diuretics showed tortuous and dilated thoracic duct (its mean diameter was 4.3 mm). In cases with refractory ascites, mean diameter of the thoracic duct was significantly reduced, compared with the cases without ascites and with ascites that respond well to the administration of diuretics. Thus, it was found that the morphological differences of the thoracic duct depend on the response to the diuretics in liver cirrhosis patients with ascites. To elucidate whether the morphological changes of the thoracic duct are observed in patients with liver cirrhosis and ascites, the thoracic duct was examined at magnetic resonance lymphography without contrast agent. In cases with refractory ascites, mean diameter of the thoracic duct was significantly reduced, compared with the cases without ascites and with ascites that respond well to the administration of diuretics. (author)

Biliary stenting and anti-cancer therapy for unresectable hilar bile duct carcinomas

International Nuclear Information System (INIS)

Saito, Hiroya; Hokotate, Hirofumi; Takeuchi, Shyuhei; Takamura, Akio

2007-01-01

At present, although imaging diagnosis has been developed, most hilar bile duct cancer is still diagnosed at an advanced stage and its prognosis is generally poor. In hilar bile duct cancer, radiotherapy and other several therapies, for example-chemotherapy, arterial-infusion chemotherapy, photodynamic therapy, etc-are being performed for non-operative cases. But standard therapies for this cancer has not been established yet. On the other hand, metallic stents (MS) have been widely used to relieve biliary obstructions as an alternative to plastic prostheses and conventional drainage. The use of MS offers good palliation in hilar bile duct cancer, but patients selection is a key to obtain good results. In this article we reviewed previous studies and clinical trials regarding the anti-cancer therapy and biliary stenting for unresectable hilar bile duct cancer. And optimal therapeutic strategy for hilar bile duct cancer is proposed, primarily based on present views. (author)

Squamous Cell Carcinoma of the Hilar Bile Duct

Directory of Open Access Journals (Sweden)

Ippei Yamana

2011-08-01

Full Text Available We herein report a rare case of squamous cell carcinoma of the hilar bile duct. A 66-year-old Japanese male patient was admitted to our hospital because of appetite loss and jaundice. Abdominal computed tomography revealed an enhanced mass measuring 10 × 30 mm in the hilar bile duct region. After undergoing biliary drainage, the patient underwent extended right hepatic lobectomy with regional lymph nodes dissection. The tumor had invaded the right portal vein. Therefore, we also performed resection and reconstruction of the portal vein. Histopathologically, the carcinoma cells exhibited a solid structure with differentiation to squamous cell carcinoma with keratinization and intercellular bridges. Immunohistochemical staining of the tumor cells revealed positive cytokeratin staining and negative CAM 5.2 staining. Based on these findings, a definitive diagnosis of well-differentiated squamous cell carcinoma of the hilar bile duct was made.

Thyroid cancer in lingual thyroid and thyroglossal duct cyst.

Science.gov (United States)

Sturniolo, Giacomo; Vermiglio, Francesco; Moleti, Mariacarla

2017-01-01

Ectopy is the most common embryogenetic defect of the thyroid gland, representing between 48 and 61% of all thyroid dysgeneses. Persistence of thyroid tissue in the context of a thyroglossal duct remnant and lingual thyroid tissue are the most common defects. Although most cases of ectopic thyroid are asymptomatic, any disease affecting the thyroid may potentially involve the ectopic tissue, including malignancies. The prevalence of differentiated thyroid carcinoma in lingual thyroid and thyroglossal duct cyst is around 1% of patients affected with the above thyroid ectopies. We here review the current literature concerning primary thyroid carcinomas originating from thyroid tissue on thyroglossal duct cysts and lingual thyroid. Copyright © 2016 SEEN. Publicado por Elsevier España, S.L.U. All rights reserved.

Intraductal papillary neoplasm of the bile duct: a case report.

Science.gov (United States)

Peeters, Karen; Delvaux, Peter; Huysentruyt, Frederik

2017-08-01

Intraductal papillary neoplasm of the bile duct (IPNB) is a rare variant of bile duct tumors, characterized by papillary growth within the bile duct lumen and is regarded as a biliary counterpart of intraductal papillary mucinous neoplasm (IPMN) of the pancreas. IPNBs are mainly found in patients from Far Eastern areas, where hepatolithiasis and clonorchiasis are endemic. The Western experience, however, remains limited. In this article, we report a 56-year-old man, referred to our hospital because of deranged liver function tests. Further imaging modalities showed a cystic lesion of 9 cm diameter, arising from the left hepatic duct. Inlying was a heterogeneous, lobulated mass. The patient underwent a left hemihepatectomy and adjuvant chemotherapy. Despite recent advanced technologies, diagnosis of IPNB is still challenging, especially in western countries due to its rarity. Early identification and resection of lesions, even in asymptomatic or minimally symptomatic patients, are however important prognostic factors.

Magnetohydrodynamics in rectangular ducts

International Nuclear Information System (INIS)

Lenhart, L.

1994-04-01

Magnetohydrodynamic flow in straight ducts or bends is a key issue, which has to be investigated for developing self-cooled liquid metal blankets of fusion reactors. The code presented solves the full set of governing equations and simulates all phenomena of such flows, including inertial effects. The range of application is limited by computer storage only. (orig./WL)

Retrograde cholangiopancreatography in the diagnosis of biliary and pancreatic duct diseases

International Nuclear Information System (INIS)

Vasil'ev, Yu.D.; Sedletskaya, T.N.

1980-01-01

Results of retrograde cannulation with the aid of flexible fibroduodenoscopes with subsequent introduction of a contrast substance into biliary and pancreatic ducts are presented. The investigation is carried out on 120 patients with different diseases of hepatopancreatoduodenal zone. The standard technique of X-ray examination has been applied permitting to obtain the most exhaustive information. Using retrograde cholangiopancreatography revealed have been choledocholithiasis, deformation of biliary ducts after surgical intervention, pancreatic cyst, tumor of the main pancreatic duct etc. Results of investigation of biliary and pancreatic ducts using retrograde cannulation are reaffirmed with the data of operations on biliary tract in 72 patients. Intraoperational cholangiography has been carried out on 36 of them during operation. An attempt to cannulate big duodenal papilla in 12 patients proved to be ineffective. No complications have been observed during examination

Bundle duct interaction studies for fuel assemblies

International Nuclear Information System (INIS)

Hsia, H.T.S.; Kaplan, S.

1981-06-01

It is known that the wire-wrapped rods and duct in an LMFBR are undergoing a gradual structural distortion from the initially uniform geometry under the combined effects of thermal expansion and irradiation induced swelling and creep. These deformations have a significant effect on flow characteristics, thus causing changes in thermal behavior such as cladding temperature and temperature distribution within a bundle. The temperature distribution may further enhance or retard irradiation induced deformation of the bundle. This report summarizes the results of the continuing effort in investigating the bundle-duct interaction, focusing on the need for the large development plant

Monitoring of Grouting Compactness in a Post-Tensioning Tendon Duct Using Piezoceramic Transducers

Directory of Open Access Journals (Sweden)

Tianyong Jiang

2016-08-01

Full Text Available A post-tensioning tendon duct filled with grout can effectively prevent corrosion of the reinforcement, maintain bonding behavior between the reinforcement and concrete, and enhance the load bearing capacity of concrete structures. In practice, grouting of the post-tensioning tendon ducts always causes quality problems, which may reduce structural integrity and service life, and even cause accidents. However, monitoring of the grouting compactness is still a challenge due to the invisibility of the grout in the duct during the grouting process. This paper presents a stress wave-based active sensing approach using piezoceramic transducers to monitor the grouting compactness in real time. A segment of a commercial tendon duct was used as research object in this study. One lead zirconate titanate (PZT piezoceramic transducer with marble protection, called a smart aggregate (SA, was bonded on the tendon and installed in the tendon duct. Two PZT patch sensors were mounted on the top outside surface of the duct, and one PZT patch sensor was bonded on the bottom outside surface of the tendon duct. In the active sensing approach, the SA was used as an actuator to generate a stress wave and the PZT sensors were utilized to detect the wave response. Cement or grout in the duct functions as a wave conduit, which can propagate the stress wave. If the cement or grout is not fully filled in the tendon duct, the top PZT sensors cannot receive much stress wave energy. The experimental procedures simulated four stages during the grout pouring process, which includes empty status, half grouting, 90% grouting, and full grouting of the duct. Experimental results show that the bottom PZT sensor can detect the signal when the grout level increases towards 50%, when a conduit between the SA and PZT sensor is formed. The top PZT sensors cannot receive any signal until the grout process is completely finished. The wavelet packet-based energy analysis was adopted in this

T-tube vs Primary Common Bile Duct Closure

Directory of Open Access Journals (Sweden)

M R Joshi

2010-09-01

Full Text Available INTRODUCTION: Closure of the common bile duct over T-tube after exploration is a widely practiced traditional method. However, its use may give rise to many complications. We do primary closure of common bile duct after exploration. Aim of the study is to see the efficacy and safety of the primary closure. METHODS: Study was carried out to compare the results of both the techniques from 2006 to 2009 in the cases proven to have common bile duct stone with or without the features of obstructive jaundice. Post operative hospital stay and morbidities related to both the groups were recorded and analyzed. RESULTS: There were total 71 cases included in the study. Thirty one in T-tube group and 40 in primary closure group. T-tube was removed in most of the cases after three weeks where as average time of drain removal in primary closure group is 5.79 +/-1.79 days. Incidence of retained stone was equal in each group. Major complication in T-tube group is biliary peritonitis in four patients at the time of T-tube removal whereas none of the patient from primary closure group suffered from such major complication. CONCLUSIONS: Primary closure after the common bile duct exploration is safe and it helps to avoid the morbidities related to T-tube. Keywords: Choledocholithiasis, Primary closure, retained stone, T-tube, Ureterorenoscope.

Change of hepatic volume after selective bile duct ligation: an experimental study in the rabbit

International Nuclear Information System (INIS)

Lee, Hye Won; Yoon, Yup; Ko, Young Tae; Choi, Woo Suk; Lim, Joo Won; Oh, Joo Hyeong; Rim, Hyeong Teck; Kim, Youn Wha; Lee, Seok Hwan

1998-01-01

To evaluate the role of bile duct obstuction in the development of atrophy of the liver, using an animal model. Seven rabbits were divided into two groups: group 1(n=3D5), in which there was selective bile duct ligation, and group 2(n=3D2), which underwent a sham operation. Each group was evaluated using CT for changes in hepatic volume after selective bile duct ligation or a sham operation. In group I, the diameter of dilated bile duct was measured 2, 4, 8, 12 and 16 weeks after bile duct ligation, while gross and histologic change were evaluated in all cases. In group 1, bile duct dilatation was seen on CT two weeks after selective bile duct ligation, and did not change significantly during follow-up. In four of five cases, CT revealed no evidence of significant atrophy of the involved segment. Pathologic specimens, however, revealed dilatation of the bile duct, periductal fibrosis, infiltration of chronic inflammatory cells, and periportal fibrosis. One of five cases showed segmental liver atrophy after selective bile duct ligation. In addion to the above pathologic findings, there was obstruction of the portal vein by foreign body reaction. In group 2, no evidence of dilated bile duct or liver atrophy was revealed by CT or pathologic specimen after a sham operation. During long-term follow-up of 16 weeks, obstruction of the bile duct did not play a major role in the development of lobar atrophy in the rabbit.=20

ASSESSMENT OF FUNGAL (PENICILLIUM CHRYSOGENUM) GROWTH ON THREE HVAC DUCT MATERIALS

Science.gov (United States)

The article discusses laboratory experiments to evaluate the susceptibility of three ventilation duct materials (fibrous glass ductboard, galvanized steel, and insulated flexible duct) to fungal (P. chrysogenum) growth. [NOTE: Many building investigators have documented fungal bi...

Evaluation of the ultimate pressure capacity of rectangular HVAC ducts for nuclear pwoer plants

International Nuclear Information System (INIS)

Wedellsborg, B.W.

1984-01-01

Typical Category I HVAC ducts in a nuclear plant must be designed for loads and load combinations including positive and negative pressure loads which are generated due to the normal operation and postulated accident conditions. These pressure loads most often govern the design of the HVAC ducts. Structural design criteria are presently based on the AISI Code which limits the duct panel width-to-thickness ratio to a maximum of 500 and the maximum height-to-thickness ratio to 200, unless it can be shown by structural tests that larger ratios can be used. Test Programs performed on rectangular HVAC ducts subjected to vacumm loads have substantiated the use of ducts having panel width to thickness ratios of up to 1600. The results of the test programs were subsequently incorporated into the design through a more rational analytical design method which was developed from and correlates well with the test results. The purpose of this paper is to present the analytical design method and its correlation with the test results. Simple formulae for the design of rectangular HVAC ducts are presented. Lower bound values of duct sheet, and stiffener ultimate loads are derived, and correlated with recent test results. Analytically predicted ultimate pressures are also compared with other available duct test data

Silver zeolite antimicrobial activity in aluminium heating, ventilation and air conditioning system ducts.

Science.gov (United States)

Rizzetto, R; Mansi, A; Panatto, D; Rizzitelli, E; Tinteri, C; Sasso, T; Gasparini, R; Crovari, P

2008-03-01

Air pollution in confined environments is a serious health problem, in that most people spend long periods indoors (in homes, offices, classrooms etc.). Some people (children, the elderly, heart disease patients, asthmatic or allergic subjects) are at greater risk because of their conditions of frailty. The growing use of air-conditioning systems in many public and private buildings aggravates this health risk, especially when these systems are not correctly installed or regularly serviced. The aim of our study was to verify the capacity of Ag+ ions to stop the growth of bacteria and moulds inside the ducts of Heating, Ventilation and Air Conditioning system ducts (HVAC) systems when these ducts were lined with active Ag+ ions zeolite-coated panels. A Y-shaped HVAC model with two branches was used; one branch was made of traditional galvanized iron, as was the whole system, while the other was lined with active Ag+ zeolite-coated polyurethane panels. During the test, samples of dust present inside both ducts were collected and seeded in liquid and solid media to detect bacteria and moulds. The presence of bacteria was also sought in the air emerging from the outlets of both ducts. Tests made on samples of particulate collected from the two different ducts revealed a lower total bacterial load in the samples collected from the Ag+ zeolite-coated duct than in the samples from the traditional Zn galvanized duct. In addition, the values of bacterial load found in the air emerging from the Ag+ ions zeolite-lined duct were 5 times lower than those found in the air from the traditional galvanized iron duct. The utilization of Ag+ zeolite-coated panels in air-conditioning systems could improve the quality of the emerging air in comparison with traditional installations in galvanized iron. This innovation could prove particularly advantageous in the event of accidents during the installation of air-conditioning systems or of contaminated aerosols coming from outside.

Differentiation of benign and malignant hilar bile duct stenosis.

Science.gov (United States)

Liu, Xiaolei; Yang, Zhiying; Tan, Haidong; Shao, Chen; Liu, Liguo; Si, Shuang; Xu, Li; Sun, Yongliang

2016-06-15

Failure to differentiate benign and malignant hilar bile duct stenosis may lead to inappropriate treatment. We retrospectively analyzed the methods for differentiation. A total of 53 patients with hilar bile duct stenosis were included, comprising 41 malignant cases (hilar cholangiocarcinoma) and 12 benign cases (six primary sclerosing cholangitis and six IgG4-associated sclerosing cholangitis). Data of clinical histories, laboratory tests, imaging studies, and liver pathologies were collected, and comparison was made between benign and malignant groups. Compared with malignant group, patients in the benign group were more likely to have multiorgan involvement of clinical histories (P < 0.001). There was no difference on bilirubin, liver enzyme, and serum tumor marker between the two groups, whereas serum IgG4 levels were higher in the benign group (P = 0.003). Patients in the benign group were more likely to have pancreatic changes (P < 0.001) and multiple-segmental bile duct stenosis (P < 0.001) on imaging. Compared with the malignant group, patients in the benign group were more likely to show severe periportal inflammation in noninvolved liver (P < 0.001), fibrosis around intrahepatic bile duct (P < 0.001), and more IgG4-positive plasma cells (P < 0.001) on liver pathology. Benign lesion should be considered for patients with history of multiorgan involvement, pancreas changes, or multiple-segmental bile duct stenosis on imaging. Liver biopsy could be helpful for differential diagnosis before surgery. Copyright © 2016 Elsevier Inc. All rights reserved.

Total rupture of hydatid cyst of liver in to common bile duct: a case report.

Science.gov (United States)

Robleh, Hassan; Yassine, Fahmi; Driss, Khaiz; Khalid, Elhattabi; Fatima-Zahra, Bensardi; Saad, Berrada; Rachid, Lefriyekh; Abdalaziz, Fadil; Najib, Zerouali Ouariti

2014-01-01

Rupture of hydatid liver cyst into biliary tree is frequent complications that involve the common hepatic duct, lobar biliary branches, the small intrahepatic bile ducts,but rarely rupture into common bile duct. The rupture of hydatid cyst is serious life threating event. The authors are reporting a case of total rupture of hydatid cyst of liver into common bile duct. A 50-year-old male patient who presented with acute cholangitis was diagnosed as a case of totally rupture of hydatid cyst on Abdominal CT Scan. Rupture of hydatid cyst of liver into common bile duct and the gallbladder was confirmed on surgery. Treated by cholecystectomy and T-tube drainage of Common bile duct.

Direct measurement of acid efflux from isolated guinea pig pancreatic ducts.

Science.gov (United States)

Hootman, Seth R; Hobbs, Errett C; Luckie, Douglas B

2005-05-01

The current studies used the technique of microphysiometry to directly determine the effects of stimulators and inhibitors of pancreatic duct secretion on acid efflux from isolated pancreatic ducts. Main and interlobular ducts were isolated from guinea pig pancreata by collagenase digestion and manual selection. Segments were placed in the chambers of a microphysiometer, which uses a silicon chip-based, light-addressable potentiometric sensor to determine the proton concentration in the superfusing solution. Isolated ducts were superfused with a low buffer capacity Ringer's solution at 37 degrees C and the extracellular acidification rate (EAR) was determined by computer-directed protocols. A survey of potential agonists demonstrated that both secretin and the cholinomimetic, carbachol, dramatically increased EAR, with EC50 of 3 nmol/L and 0.6 mumol/L, respectively. The changes in EAR induced by both secretagogues were rapid, peaking within 4-6 minutes, and then declining to a level below the peak but above basal EAR. The enhanced EAR was maintained for at least 30 minutes in the presence of either secretagogue. More modest increases in EAR were evoked by bombesin, substance P, and vasoactive intestinal peptide (VIP). Cholecystokinin and isoproterenol caused no significant change in pancreatic duct EAR. A combination of amiloride and bafilomycin A1, inhibitors, respectively, of Na/H exchange and of vacuolar type H-ATPase activity, caused a dramatic drop in EAR but did not fully inhibit the increase in EAR elicited by carbachol, suggesting that other mechanisms may contribute to agonist-stimulated EAR of pancreatic ducts. Thus, the results support the use of microphysiometry as a tool to study pancreatic duct physiology and in particular a method to measure acid efflux from the serosal surface.

Surgical management of bile duct injuries following open or laparoscopic cholecystectomy

International Nuclear Information System (INIS)

Hadi, A.; Aman, Z.; Khan, S.A.

2013-01-01

Objective: To evaluate the management of bile duct injuries following open and laparoscopic cholecystectomy in a tertiary care hospital. Methods: The descriptive case series was conducted from July 2002 to June 2008 at Hayatabad Medical Complex Peshawar, Pakistan. A total of 32 patients who sustained extra hepatic bile duct injuries during open and laparoscopic cholecystectomy were included. Patients having hepatobiliary malignancy or those managed through endoscopic retrograde cholangiopancreatography and stenting were excluded. Patients were thoroughly investigated including to reach a final diagnosis, and were followed up for 02 years. Results: The mean age of patients was 45.4+9-2.7 years with a female preponderance (M:F=1:9.7). The time of presentation was up to 03 months after initial surgery. Seven (21.87%) patients sustained bile duct injury during laparoscopic cholecystectomy, while 25 (78.13%) sustained injury during open procedure. Abdominal ultrasound scan was performed in 29 (90.63%) cases, endoscopic retrograde cholangiopancreatography in 14 (43.75%) and magnetic resonance cholangiopancreatography in 26 (81.25%) cases. Eleven (34.37%) patients had common bile duct leak, 9 (28.13%) had common hepatic duct injury, 9 (28.13%) had CBD strictures and 3 (09.37%) had injury to the biliary tree at porta hepatis level. Operative procedures performed included Roux-en-Y hepaticojejunostomy in 19 (59.38%) cases, choledochoduodenostomy in 7 (21.88%) cases, Roux-en-Y portoentrostomy and primary repair in 3 (09.37%) cases each. Postoperative morbidity included recurrent cholangitis 9 (28.12%), wound infection 4 (12.50%) and bile leakage 2 (06.25%). Hospital stay ranged 08-16 days. Hospital mortality rate was 03.13%, (n=1). Conclusion: The most frequent site of bile duct injury during open and laparoscopic cholecystectomy was the common bile duct, and Roux-en-Y hepaticojejunostomy was the procedure of choice by experienced surgeons for the management of such injuries

Endoscopic versus surgical drainage of the pancreatic duct in chronic pancreatitis.

Science.gov (United States)

Cahen, Djuna L; Gouma, Dirk J; Nio, Yung; Rauws, Erik A J; Boermeester, Marja A; Busch, Olivier R; Stoker, Jaap; Laméris, Johan S; Dijkgraaf, Marcel G W; Huibregtse, Kees; Bruno, Marco J

2007-02-15

For patients with chronic pancreatitis and a dilated pancreatic duct, ductal decompression is recommended. We conducted a randomized trial to compare endoscopic and surgical drainage of the pancreatic duct. All symptomatic patients with chronic pancreatitis and a distal obstruction of the pancreatic duct but without an inflammatory mass were eligible for the study. We randomly assigned patients to undergo endoscopic transampullary drainage of the pancreatic duct or operative pancreaticojejunostomy. The primary end point was the average Izbicki pain score during 2 years of follow-up. The secondary end points were pain relief at the end of follow-up, physical and mental health, morbidity, mortality, length of hospital stay, number of procedures undergone, and changes in pancreatic function. Thirty-nine patients underwent randomization: 19 to endoscopic treatment (16 of whom underwent lithotripsy) and 20 to operative pancreaticojejunostomy. During the 24 months of follow-up, patients who underwent surgery, as compared with those who were treated endoscopically, had lower Izbicki pain scores (25 vs. 51, Psurgical drainage (P=0.007). Rates of complications, length of hospital stay, and changes in pancreatic function were similar in the two treatment groups, but patients receiving endoscopic treatment required more procedures than did patients in the surgery group (a median of eight vs. three, PSurgical drainage of the pancreatic duct was more effective than endoscopic treatment in patients with obstruction of the pancreatic duct due to chronic pancreatitis. (Current Controlled Trials number, ISRCTN04572410 [controlled-trials.com].). Copyright 2007 Massachusetts Medical Society.

Wind Turbine With Concentric Ducts

Science.gov (United States)

Muhonen, A. J.

1983-01-01

Wind Turbine device is relatively compact and efficient. Converging inner and outer ducts increase pressure difference across blades of wind turbine. Turbine shaft drives alternator housed inside exit cone. Suitable for installation on such existing structures as water towers, barns, houses, and commercial buildings.

Sound algorithms

OpenAIRE

De Götzen , Amalia; Mion , Luca; Tache , Olivier

2007-01-01

International audience; We call sound algorithms the categories of algorithms that deal with digital sound signal. Sound algorithms appeared in the very infancy of computer. Sound algorithms present strong specificities that are the consequence of two dual considerations: the properties of the digital sound signal itself and its uses, and the properties of auditory perception.

Novel immunohistochemical markers differentiate intrahepatic cholangiocarcinoma from benign bile duct lesions.

Science.gov (United States)

Bertram, Stefanie; Padden, Juliet; Kälsch, Julia; Ahrens, Maike; Pott, Leona; Canbay, Ali; Weber, Frank; Fingas, Christian; Hoffmann, Andreas C; Vietor, Antonie; Schlaak, Joerg F; Eisenacher, Martin; Reis, Henning; Sitek, Barbara; Baba, Hideo A

2016-07-01

The distinction between intrahepatic cholangiocarcinoma (ICC) and benign bile duct lesions can be challenging. Using our previously identified potential biomarkers for ICC, we examined whether these are useful for the differential diagnosis of ICC, bile duct adenoma and reactive bile duct proliferations in an immunohistochemical approach and identified a diagnostic marker panel including known biomarkers. Subjects included samples from 77 patients with ICC, 33 patients with bile duct adenoma and 47 patients with ductular reactions in liver cirrhosis. Our previously identified biomarkers (stress-induced phosphoprotein 1 (STIP1), SerpinH1, 14-3-3Sigma) were tested immunohistochemically following comparison with candidates from the literature (cluster of differentiation 56, heat shock protein (HSP)27, HSP70, B-cell-lymphoma2, p53, ki67). The expression of SerpinH1 and 14-3-3Sigma was significantly higher in ICC than in bile duct adenomas and ductular reactions (p5% might be used for the distinction of malignant and non-malignant lesions. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

New tapered metallic stent for unresectable malignant hilar bile duct obstruction.

Science.gov (United States)

Sakai, Yuji; Tsuyuguchi, Toshio; Nishikawa, Takao; Sugiyama, Harutoshi; Sasaki, Reina; Sakamoto, Dai; Watanabe, Yuto; Nakamura, Masato; Yasui, Shin; Mikata, Rintaro; Yokosuka, Osamu

2015-10-16

To examine the usefulness of a new tapered metallic stent (MS) in patients with unresectable malignant hilar bile duct obstruction. This new tapered MS was placed in 11 patients with Bismuth II or severer unresectable malignant hilar bile duct obstruction, as a prospective study. The subjects were six patients with bile duct carcinoma, three with gallbladder cancer, and two with metastatic bile duct obstruction. Stenosis morphology was Bismuth II: 7, IIIa: 3, and IV: 1. UMIN Clinical Trial Registry (UMIN000004758). MS placement was 100% (11/11) successful. There were no procedural accidents. The mean patency period was 208.401 d, the median survival period was 142.000 d, and the mean survival period was 193.273 d. Occlusion rate was 36.4% (4/11); the causes of occlusion were ingrowth and overgrowth in 2 patients each, 18.2%, respectively. Patients with occlusion underwent endoscopic treatment one more time and all were treatable. The tapered MS proved useful in patients with unresectable malignant hilar bile duct obstruction because it provided a long patency period, enabled re-treatment by re-intervention, and no procedural accidents occurred.

Thermal behavior of the duct applied functionally graded material

Energy Technology Data Exchange (ETDEWEB)

Park, Jung Sun; Yoon, Dong Young; Im, Jong Bin [Hankuk Aviation Univ., Goyang (Korea, Republic of)

2004-07-01

In Unmanned Aerial Vehicles (UAV), the high temperature results from friction among the air, combustion of fuel in engine and combustion gas of a nozzle. The high temperature may cause serious damages in UAV structure. The Functionally Graded Material(FGM) is chosen as a material of the engine duct structure. Thermal stress analysis of FGM is performed in this paper. FGM is composed of two constituent materials that are mixed up according to the specific volume fraction distribution in order to withstand high temperature. Therefore, hoop stress, axial stress and shear stress of duct with 2 layers, 4 layers and 8 layers FGM are compared and analyzed respectively. In addition, the creep behavior of FGM used in duct structure of an engine is analyzed for better understanding of FGM characteristics.

Synchronous double primary cancers of the extrahepatic bile duct: A case report and literature review.

Science.gov (United States)

Nishi, Takeshi; Sato, Yoshitoshi; Hanaoka, Takuya; Takahashi, Takuya; Miura, Hiroshi; Takubo, Kenji

2018-01-01

Double cancers of the biliary tract system are rare. Most of these cancers are synchronous double cancers of the gall bladder and bile duct, associated with pancreaticobiliary maljunction (PBM). Synchronous double cancers of the extrahepatic bile duct without PBM are especially rare, and only 4 cases have been reported. A 78-year-old woman was admitted to our hospital for examination of hyperbilirubinemia and liver dysfunction. Contrast-enhanced abdominal computed tomography, Magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography revealed 2 stenotic regions in the common bile duct: at its junction with the cystic duct and in the distal bile duct. No findings suggested PBM, such as a markedly long common channel. The diagnosis based on endoscopic brush cytology from both stricture portions was adenocarcinoma. The patient had a pylorus-preserving pancreaticoduodenectomy with regional lymph node resection. Macroscopically, there were 2 stenotic regions at the cystic duct junction and in the distal bile duct. Microscopically, the tumor at the junction of the cystic duct was a well-to-moderately differentiated adenocarcinoma. On the other hand, the tumor of the distal bile duct was a poorly differentiated adenocarcinoma. There was no evidence of communication between these 2 cancers. Double cancers of the extrahepatic bile duct without PBM are very rare. Therefore, an accurate diagnosis prior to surgery is necessary. Furthermore, this rare condition seems to be associated with a poor prognosis. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Impedance Eduction in Large Ducts Containing Higher-Order Modes and Grazing Flow

Science.gov (United States)

Watson, Willie R.; Jones, Michael G.

2017-01-01

Impedance eduction test data are acquired in ducts with small and large cross-sectional areas at the NASA Langley Research Center. An improved data acquisition system in the large duct has resulted in increased control of the acoustic energy in source modes and more accurate resolution of higher-order duct modes compared to previous tests. Two impedance eduction methods that take advantage of the improved data acquisition to educe the liner impedance in grazing flow are presented. One method measures the axial propagation constant of a dominant mode in the liner test section (by implementing the Kumarsean and Tufts algorithm) and educes the impedance from an exact analytical expression. The second method solves numerically the convected Helmholtz equation and minimizes an objective function to obtain the liner impedance. The two methods are tested first on data synthesized from an exact mode solution and then on measured data. Results show that when the methods are applied to data acquired in the larger duct with a dominant higher-order mode, the same impedance spectra are educed as that obtained in the small duct where only the plane wave mode propagates. This result holds for each higher-order mode in the large duct provided that the higher-order mode is sufficiently attenuated by the liner.

Repair of a common bile duct defect with a decellularized ureteral graft

Science.gov (United States)

Cheng, Yao; Xiong, Xian-Ze; Zhou, Rong-Xing; Deng, Yi-Lei; Jin, Yan-Wen; Lu, Jiong; Li, Fu-Yu; Cheng, Nan-Sheng

2016-01-01

AIM To evaluate the feasibility of repairing a common bile duct defect with a decellularized ureteral graft in a porcine model. METHODS Eighteen pigs were randomly divided into three groups. An approximately 1 cm segment of the common bile duct was excised from all the pigs. The defect was repaired using a 2 cm long decellularized ureteral graft over a T-tube (T-tube group, n = 6) or a silicone stent (stent group, n = 6). Six pigs underwent bile duct reconstruction with a graft alone (stentless group). The surviving animals were euthanized at 3 mo. Specimens of the common bile ducts were obtained for histological analysis. RESULTS The animals in the T-tube and stent groups survived until sacrifice. The blood test results were normal in both groups. The histology results showed a biliary epithelial layer covering the neo-bile duct. In contrast, all the animals in the stentless group died due to biliary peritonitis and cholangitis within two months post-surgery. Neither biliary epithelial cells nor accessory glands were observed at the graft sites in the stentless group. CONCLUSION Repair of a common bile duct defect with a decellularized ureteral graft appears to be feasible. A T-tube or intraluminal stent was necessary to reduce postoperative complications. PMID:28082809

Active control of turbulent boundary layer sound transmission into a vehicle interior

International Nuclear Information System (INIS)

Caiazzo, A; Alujević, N; Pluymers, B; Desmet, W

2016-01-01

In high speed automotive, aerospace, and railway transportation, the turbulent boundary layer (TBL) is one of the most important sources of interior noise. The stochastic pressure distribution associated with the turbulence is able to excite significantly structural vibration of vehicle exterior panels. They radiate sound into the vehicle through the interior panels. Therefore, the air flow noise becomes very influential when it comes to the noise vibration and harshness assessment of a vehicle, in particular at low frequencies. Normally, passive solutions, such as sound absorbing materials, are used for reducing the TBL-induced noise transmission into a vehicle interior, which generally improve the structure sound isolation performance. These can achieve excellent isolation performance at higher frequencies, but are unable to deal with the low-frequency interior noise components. In this paper, active control of TBL noise transmission through an acoustically coupled double panel system into a rectangular cavity is examined theoretically. The Corcos model of the TBL pressure distribution is used to model the disturbance. The disturbance is rejected by an active vibration isolation unit reacting between the exterior and the interior panels. Significant reductions of the low-frequency vibrations of the interior panel and the sound pressure in the cavity are observed. (paper)

46 CFR 7.20 - Nantucket Sound, Vineyard Sound, Buzzards Bay, Narragansett Bay, MA, Block Island Sound and...

Science.gov (United States)

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Nantucket Sound, Vineyard Sound, Buzzards Bay, Narragansett Bay, MA, Block Island Sound and easterly entrance to Long Island Sound, NY. 7.20 Section 7.20... Atlantic Coast § 7.20 Nantucket Sound, Vineyard Sound, Buzzards Bay, Narragansett Bay, MA, Block Island...

Morphological study of pancreatic duct in red jungle fowl | Kadhim ...

African Journals Online (AJOL)

Neither goblet cells nor ductal glands were found in the pancreatic ducts. Secretion of both neutral and sulfated materials by the epithelial lining the pancreatic ducts, suggesting that they are acting not only to facilitate the transport of the pancreatic juice, but also as a protective barrier to protect the gland from autodigestion.

LOFT CIS analysis penetration S-11B 12'' H and V duct

International Nuclear Information System (INIS)

Condie, C.G.

1978-01-01

The 12 in. H and V Duct and related piping outside the LOFT containment and connected to containment penetration S-11B was analyzed to ASME Code, Subsection NC (Class 2) criteria. This duct is part of the Containment Isolation System. The model considered the duct from the containment O.D. outward through the second isolation valve. Results of this analysis show that this section of the line will meet Class 2 requirements without modification

Endoscopic versus surgical drainage of the pancreatic duct in chronic pancreatitis

NARCIS (Netherlands)

Cahen, Djuna L.; Gouma, Dirk J.; Nio, Yung; Rauws, Erik A. J.; Boermeester, Marja A.; Busch, Olivier R.; Stoker, Jaap; Lameris, Johan S.; Dijkgraaf, Marcel G. W.; Huibregtse, Kees; Bruno, Marco J.

2007-01-01

BACKGROUND: For patients with chronic pancreatitis and a dilated pancreatic duct, ductal decompression is recommended. We conducted a randomized trial to compare endoscopic and surgical drainage of the pancreatic duct. METHODS: All symptomatic patients with chronic pancreatitis and a distal

Parametric investigation of fracture of EBR-II ducts

International Nuclear Information System (INIS)

Chopra, P.S.; Moustakakis, B.

1977-01-01

Results of preliminary static and dynamic finite element fracture mechanics analyses that were conducted to analytically simulate the dynamic fracture behavior of EBR-II ducts are presented. The loads considered are those that may arise because of rapid release of fission gases from a failed fuel element inside a duct, obtained from some previous tests and a recent analytical model. In spite of the motivation for the present work, the analytical procedures described may have a wider general application in the fail-safe design of structures

A cost analysis of operative repair of major laparoscopic bile duct injuries.

Science.gov (United States)

Hofmeyr, S; Krige, J E J; Bornman, P C; Beningfield, S J

2015-06-01

Major bile duct injuries occur infrequently after laparoscopic cholecystectomy, but may result in life-threatening complications. Few data exist on the financial implications of duct repair. This study calculated the costs of operative repair in a cohort of patients who underwent reconstruction of the bile duct after major ductal injury. To calculate the total in-hospital cost of surgical repair of patients referred with major bile duct injuries. A prospective database was reviewed to identify all patients referred to the University of Cape Town Private Academic Hospital, South Africa, between 2002 and 2013 for assessment and repair of major laparoscopic bile duct injuries. The detailed clinical records and billing information were evaluated to determine all costs from admission to discharge. Total costs for each patient were adjusted for inflation between the year of repair and 2013. Results. Forty-four patients (33 women, 11 men; median age 48 years, range 30 - 78) underwent reconstruction of a major bile duct injury. First-time repairs were performed at a median of 24.5 days (range 1 - 3,662) after initial surgery. Median hospital stay was 15 days (range 6 - 86). Mean cost of repair was ZAR215,711 (range ZAR68,764 - 980,830). Major contributors to cost were theatre expenses (22%), admission to intensive care (21%), radiology (17%) and specialist fees (12%). Admission to a general ward (10%), consumables (7%), pharmacy (5%), endoscopy (3%) and laboratory costs (3%) made up the balance. The cost of repair of a major laparoscopic bile duct injury is substantial owing to prolonged hospitalisation, complex surgicalintervention and intensive imaging requirements.

Understanding the Mechanical forces of Self-Expandable Metal Stents in the Biliary Ducts.

Science.gov (United States)

Isayama, Hiroyuki; Nakai, Yousuke; Hamada, Tsuyoshi; Matsubara, Saburo; Kogure, Hirofumi; Koike, Kazuhiko

2016-12-01

Self-expandable metallic stent (SEMS) was an effective biliary endoprosthesis. Mechanical properties of SEMS, radial and axial force (RF, AF), may play important roles in the bile duct after placement. RF was well known dilation force and influenced on the occurrence of migration. AF, newly proposed by this author, was defined as the recovery force when the SEMS vended. AF was related with the cause of bile duct kinking, pancreatitis, and cholecystitis due to the compression of the bile duct, orifice of the cystic duct, and pancreatic orifice. Ideal SEMS may show high RF and low AF.

Compact Buried Ducts in a Hot-Humid Climate House

Energy Technology Data Exchange (ETDEWEB)

Mallay, D. [Home Innovation Research Labs, Upper Marlboro, MD (United States)

2016-01-01

A system of compact, buried ducts provides a high-performance and cost-effective solution for delivering conditioned air throughout the building. This report outlines research activities that are expected to facilitate adoption of compact buried duct systems by builders. The results of this research would be scalable to many new house designs in most climates and markets, leading to wider industry acceptance and building code and energy program approval.

Experimental and theoretical investigations on the dynamic response of EBR-II ducts under pressure pulse loading

International Nuclear Information System (INIS)

Chopra, P.S.; Srinivas, S.

1975-01-01

In order to assess the potential damage to hexagonal subassembly ducts (cans) that may result from rapid gas release from a failed element the EBR-II project has conducted experiments and analyses. Additional experimental and analytical investigations are now being conducted to assure fail-safety of the ducts. Fail-safety is defined as the ability of a duct to withstand pressure pulses from failed elements during all reactor conditions without damage to adjacent ducts or any other problems in fuel handling. The results of 93 EBR-II duct tests conducted primarily by Koenig have been reported previously. The results of empirical correlations of some of these tests to determine the influence of several variables on the pressure pulse experienced by a duct and on the duct deformation are presented. The variables include the type of gas contained in the simulated element (tube), the element and duct materials, the presence or absence of flow restrictors in the element, and the way gas was released. 8 references. (auth)

The Impact of Bile Duct Cultures on Surgical Site Infections in Pancreatic Surgery.

Science.gov (United States)

Herzog, Torsten; Belyaev, Orlin; Akkuzu, Rehsan; Hölling, Janine; Uhl, Waldemar; Chromik, Ansgar M

2015-08-01

In pancreatic surgery pre-operative biliary drainage (PBD) is associated with bacteribilia, which increases the risk for surgical site infections (SSIs). This study is a retrospective observational cohort design that compared micro-organisms of intra-operative bile duct cultures with micro-organisms of SSIs after pancreaticoduodenectomy. From January 2004 until December 2010, 887 patients underwent pancreaticoduodenectomy or hepaticojejunostomy for benign and malignant peri-ampullary lesions. Surgical site infections occurred in 10% (87/887). Cultures of SSIs with corresponding intra-operative bile duct cultures were available for 59 patients. Sixty-four percent (38/59) had undergone PBD. Pre-operative biliary drainage was associated with positive intra-operative bile duct cultures in 95% (36/38), versus 48% (10/21; p≤0.001). The correlation of SSIs with intra-operative bile duct cultures was 59% (35/59). There was a significant association between the micro-organisms cultured from SSIs and the corresponding bile duct cultures for Enterococcus spp., Escherichia coli, Klebsiella pneumoniae, methicillin-resistant Staphylococcus aureus (MRSA), Enterobacteriaceae with extended spectrum ß-lactamase (ESBL), and Candida spp. After pancreaticoduodenectomy, SSIs are often caused by the same micro-organisms that are present on intra-operative bile duct cultures, especially after PBD. Therefore, intra-operative bile duct cultures should be performed routinely to adjust the antibiotic prophylaxis according to the local hospital surveillance data.

Extrahepatic duct injury in blunt trauma: two case reports and a literature review.

Science.gov (United States)

Zago, Thiago Messias; Pereira, Bruno Monteiro Tavares; Calderan, Thiago Rodrigues Araujo; Hirano, Elcio Shiyoiti; Fraga, Gustavo Pereira

2014-08-01

Traumatic injuries of the extrahepatic biliary tract are rare. Associated injuries are usually responsible for immediate indication for surgical treatment, the time when an injury to the extrahepatic biliary ducts may be diagnosed. However, missed injuries are often common. The primary aim of this paper is to describe the clinical features, diagnosis, treatment, and outcome of two patients with left hepatic duct injury after blunt abdominal trauma. As a secondary objective, a literature review is presented. The two cases presented in this study are as follows: (1) A young male, involved in a motor vehicle crash, was admitted with blunt hepatic trauma in a general hospital. Endoscopic retrograde cholangiography was conducted 3 weeks later and revealed a large leakage at the left hepatic duct. Exploratory laparotomy was performed 26 days after the initial traumatic event and identified a complete section of the left hepatic duct, treated with anastomosis. (2) A male fell from a height. On exploratory laparotomy, a 30 % partial injury of the left hepatic duct was found in addition to hemoperitoneum, liver injury, gallbladder detachment together with cystic duct rupture, retroperitoneal hematoma to the right, and cecum hematoma. A high level of suspicion is necessary to identify injuries to the hepatic ducts. Early diagnosis that occurs during laparotomy due to associated injuries is important to reduce complications.

Laparoscopic managment of common bile duct stones: our initial experience.

Science.gov (United States)

Aroori, S; Bell, J C

2002-05-01

The management of choledocholithiasis has changed radically since the introduction of laparoscopic cholecystectomy. However, perceived technical difficulties have deterred many surgeons from treating common bile duct stones laparoscopically at the time of cholecystectomy. This has lead to reliance on endoscopic retrograde cholangiopancreatography followed by endoscopic sphincterotomy to deal with common bile duct stones. We retrospectively reviewed the charts of patients who had laparoscopic common bile duct exploration at Downe Hospital between December 1999 and August 2001. Among 149 laparoscopic cholecystectomies done by our group in this period, 10 patients (6.7%) underwent laparoscopic CBD exploration, three by the transcystic technique and seven by choledochotomy. Three patients (2%) had unsuspected stones found on routine per- operative cholangiogram. The mean operative time was 2.34hrs (range 1.50-3.30hrs). The mean hospital post- operative stay was 3 days (range 1-6 days). Post-operative morbidity was zero. Stone clearance was achieved in all cases. We conclude, laparoscopic exploration of the common bile duct is relatively safe and straightforward method. The key skill required is the ability to perform laparoscopic suturing with confidence.

Noninvasive study of anatomic variations of the bile and pancreatic duct using magnetic resonance cholangiopancreatography

International Nuclear Information System (INIS)

Fernandez, E.; Falco, J.; Campo, R.; Martin, J.; Brullet, E.; Espinos, J.

1999-01-01

To identify anatomic variations of the bile duct and pancreatic duct and papillary anomalies by means of magnetic resonance cholangiopancreatography (MRCP) and determine their correlation with endoscopic retrograde cholangiopancreatography (ERCP) findings. Eighty-five patients were selected by means of a prospective study comparing MRCP and ERCP. Coronal and axial HASTE images and coronal and oblique coronal RARE images were acquired in all the patients. Four of the studies (6%) were excluded because of poor technical quality. Anatomic variations were observed in 26 cases (30.5%), including trifurcation (n=7; 27%), right hepatic duct draining into left hepatic duct (n=2, 7.7%), right hepatic duct draining into common bile duct (n=4; 15.4%), extrahepatic confluence (n=2; 7.7%), medial cystic duct (n=2; 7.7%), parallel cystic duct (n=3; 11.5%), juxtapapillary duodenal diverticulum (n=3; 11.5%) and pancreas divisum (n=3; 11.5%). A good correlation was observed between the MRCP and ERCP findings. The introduction of MRCP into the noninvasive study of biliary disease may be useful in the detection of anatomic variations relevant to laparoscopic surgery and other endoscopic and interventional techniques. (Author) 11 refs

Prognostic factors and diagnosis of extent of the bile duct cancer

International Nuclear Information System (INIS)

Kai, Masahiro; Chijiiwa, Kazuo; Otani, Kazuhiro; Ouchida, Jiro; Kondo, Kazuhiro; Nagano, Motoaki; Hiyoshi, Masahide; Imamura, Naoya

2009-01-01

To improve the survival of the patients with extrahepatic bile duct cancer, the factors influencing survival and the accuracy of preoperative diagnosis were examined. The factors influencing survival were retrospectively analyzed in 115 patients (mid and lower; n=61, hilar and superior; n=44, diffusely spread; n=10) with extrahepatic bile duct cancer who underwent surgical resection from 1990 to 2008. The preoperative diagnosis of the tumor extension using multi detector row CT (MDCT), endoscopic retrograde cholangiopancreatography (ERCP), intraductal ultrasonography (IDUS) and endoscopic ultrasonography (EUS) was compared with the final pathological diagnosis in patients underwent surgical resection (mid and lower; n=32, hilar and superior; n=11, diffusely spread; n=8) from 2003 to 2008. In patients with mid and lower bile duct cancer (n=61), lymph node metastasis and surgical margin were the independent prognostic factors in the multivariate analysis. Whereas none was found in hilar and superior bile duct cancer (n=44). The sensitivity, specificity and accuracy of the preoperative diagnosis for the depth of tumor invasion (serosal and/or pancreas invasion) was 66.7%, 69.4% and 68.6%, and for the liver invasion was 100%, 88.0%, 88.2%, and for the lymph node metastasis was 76.9%, 71.0%, 72.5%, respectively. More than a few cases were under diagnosed the tumor extension. In patients with mid and lower bile duct cancer, the accuracy of preoperative diagnosis for the depth of tumor invasion (serosal and/or pancreas) was 59.4%. In patients with hilar and superior bile duct cancer, the accuracy of preoperative diagnosis for the serosal and hepatic invasion is 81.8% and 54.5%. Positive surgical margin was 9.1% for hilar and superior, 9.4% for mid and lower and 50.0% for diffusely spread bile duct cancer. Especially, The horizontal spread was difficult to evaluate in patients with diffusely spread bile duct cancer. From 2003 to 2008, the rate of positive surgical margin

Morbidity and mortality after minor bile duct injury following laparoscopic cholecystectomy

NARCIS (Netherlands)

Booij, Klaske A. C.; de Reuver, Philip R.; Yap, Kenneth; van Dieren, Susan; van Delden, Otto M.; Rauws, Erik A.; Gouma, Dirk J.

2015-01-01

Cystic duct and Luschka duct leakage after laparoscopic cholecystectomy are often classified as minor injuries because the outcome of endoscopic stenting and percutaneous drainage is generally reported to be good. However, the potential associated early mortality and risk factors for mortality are

Percutaneous management of bile duct injury after laparoscopic cholecystectomy

International Nuclear Information System (INIS)

Islim, F.; Ors, S.; Salik, A.; Guven, K.; Yanar, F.; Alis, H.

2012-01-01

Full text: Introduction: The risk of bile duct injury after laparoscopic cholecystectomy is higher than open cholecystectomy. Objective: To discuss the importance of minimally invasive treatment options in the management of bile duct injuries after laparoscopic cholecystectomy and to present our approach in the management. Materials and methods: Management of 25 patients with symptomatic bile duct injury after laparoscopic cholecystectomy was retrospectively evaluated. Percutaneous collection drainage, endoscopic retrograde cholangiopancreatography (ERCP), percutaneous transhepatic cholangiography (PTC) and percutaneous biliary drainage were performed for the management of the patients. Results: Mean age of the patients (15 women, 10 men) was 55. Either ultrasonography or computed tomography guided percutaneous drainage was performed in 13 patients. 9 of them completely recovered only with percutaneous drainage. In 4 of them ERCP was performed because of high drainage volume. In 9 of the patients with jaundice and high bilirubin levels ERCP was performed as the first option. And 3 patients were reoperated because of acute abdomen signs. ERCP, MRCP and PTC revealed type A in 7, type E2 in 3, type E3 in 3 and type E4 in 1 of the patients according to Strasberg classification. Conclusion: Presenting symptoms of the patients with symptomatic bile duct injury are useful in the determination of the treatment option.

Single Mode Theory for Impedance Eduction in Large-Scale Ducts with Grazing Flow

Science.gov (United States)

Watson, Willie R.; Gerhold, Carl H.; Jones, Michael G.; June, Jason C.

2014-01-01

An impedance eduction theory for a rigid wall duct containing an acoustic liner with an unknown impedance and uniform grazing flow is presented. The unique features of the theory are: 1) non-planar waves propagate in the hard wall sections of the duct, 2) input data consist solely of complex acoustic pressures acquired on a wall adjacent to the liner, and 3) multiple higher-order modes may exist in the direction perpendicular to the liner and the opposite rigid wall. The approach is to first measure the axial propagation constant of a dominant higher-order mode in the liner sample section. This axial propagation constant is then used in conjunction with a closed-form solution to a reduced form of the convected Helmholtz equation and the wall impedance boundary condition to educe the liner impedance. The theory is validated on a conventional liner whose impedance spectrum is educed in two flow ducts with different cross sections. For the frequencies and Mach numbers of interest, no higher-order modes propagate in the hard wall sections of the smaller duct. A benchmark method is used to educe the impedance spectrum in this duct. A dominant higher-order vertical mode propagates in the larger duct for similar test conditions, and the current theory is applied to educe the impedance spectrum. Results show that when the theory is applied to data acquired in the larger duct with a dominant higher-order vertical mode, the same impedance spectra is educed as that obtained in the small duct where only the plane wave mode is present and the benchmark method is used. This result holds for each higher-order vertical mode that is considered.

Active noise cancellation of low frequency noise propagating in a duct

Directory of Open Access Journals (Sweden)

Farhad Forouharmajd

2012-01-01

Conclusions: With regard to the wide range of frequencies of different noise sources, having optimized circumstances in the duct, microphone location on the duct body or even the distance of the speakers may be important in signal processing, noise sampling and anti noise production.

EKSTRAHEPATIC BILE DUCT CANCER

OpenAIRE

Aleš Tomažič; Dragan Stanisavljevič; Valentin Sojar; Blaž Trotovšek

2003-01-01

Background. Malignant strictures involving the bile ducts remain a major challenge in biliary surgery. It is an uncommon cancer. The etiology is unknown, most cases are sporadic, but several conditions confer an incrised risk of developing cholangiocarcinoma.Clinical presentation and preoperative evaluation. The early simptoms are nonspecific. In the past computed tomography, percutaneous transhepatic cholangiography and angiography were considered standard investigations, but currently magne...

Thermal performance test of hot gas ducts of helium engineering demonstration loop (HENDEL)

International Nuclear Information System (INIS)

Hishida, Makoto; Kunitomi, Kazuhiko; Ioka, Ikuo; Umenishi, Koji; Kondo, Yasuo; Tanaka, Toshiyuki; Shimomura, Hiroaki

1984-01-01

A hot gas duct provided with internal thermal insulation is supposed to be used for an experimental very high-temperature gas-cooled reactor (VHTR) which has been developed by the Japan Atomic Energy Research Institute (JAERI). This type of hot gas duct has not been used so far in industrial facilities, and only a couple of tests on such a large-scale model of hot gas duct have been conducted. The present test was to investigate the thermal performance of the hot gas ducts which are installed as parts of a helium engineering demonstration loop (HENDEL) of JAERI. Uniform temperature and heat flux distributions at the surface of the duct were observed, the experimental correlation being obtained for the effective thermal conductivity of the internal thermal insulation layer. The measured temperature distribution of the pressure tube was in good agreement with the calculation by a TRUMP heat transfer computer code. The temperature distribution of the inner tube of VHTR hot gas duct was evaluated, and no hot spot was detected. These results would be very valuable for the design and development of VHTR. (author)

Cholestasis progression effects on long-term memory in bile duct ligation rats

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Nasrin Hosseini

2014-01-01

Full Text Available Background : There is evidence that cognitive functions are affected by some liver diseases such as cholestasis. Bile duct ligation induces cholestasis as a result of impaired liver function and cognition. This research investigates the effect of cholestasis progression on memory function in bile duct ligation rats. Materials and Methods: Male Wistar rats were randomly divided into five groups, which include: control group for BDL-7, control group for BDL-21, sham group (underwent laparotomy without bile duct ligation, BDL-7 group (7 days after bile duct ligation, and BDL-21 group (21 days after bile duct ligation. Step-through passive avoidance test was employed to examine memory function. In all groups, short-term (7 days after foot shock and long-term memories (21 days after foot shock were assessed. Results: Our results showed that liver function significantly decreased with cholestasis progression (P < 0.01. Also our findings indicated BDL-21 significantly impaired acquisition time (P < 0.05. Memory retrieval impaired 7 (P < 0.05 and 21 days (P < 0.001 after foot shock in BDL-7 and BDL-21 groups, respectively. Conclusion: Based on these findings, liver function altered in cholestasis and memory (short-term and long-term memory impaired with cholestasis progression in bile duct ligation rats. Further studies are needed to better insight the nature of progression of brain damage in cholestatic disease.

Plasticity of adult human pancreatic duct cells by neurogenin3-mediated reprogramming.

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Nathalie Swales

Full Text Available AIMS/HYPOTHESIS: Duct cells isolated from adult human pancreas can be reprogrammed to express islet beta cell genes by adenoviral transduction of the developmental transcription factor neurogenin3 (Ngn3. In this study we aimed to fully characterize the extent of this reprogramming and intended to improve it. METHODS: The extent of the Ngn3-mediated duct-to-endocrine cell reprogramming was measured employing genome wide mRNA profiling. By modulation of the Delta-Notch signaling or addition of pancreatic endocrine transcription factors Myt1, MafA and Pdx1 we intended to improve the reprogramming. RESULTS: Ngn3 stimulates duct cells to express a focused set of genes that are characteristic for islet endocrine cells and/or neural tissues. This neuro-endocrine shift however, is incomplete with less than 10% of full duct-to-endocrine reprogramming achieved. Transduction of exogenous Ngn3 activates endogenous Ngn3 suggesting auto-activation of this gene. Furthermore, pancreatic endocrine reprogramming of human duct cells can be moderately enhanced by inhibition of Delta-Notch signaling as well as by co-expressing the transcription factor Myt1, but not MafA and Pdx1. CONCLUSIONS/INTERPRETATION: The results provide further insight into the plasticity of adult human duct cells and suggest measurable routes to enhance Ngn3-mediated in vitro reprogramming protocols for regenerative beta cell therapy in diabetes.

Regulation of the Na+/Ca2+ exchanger in rat pancreatic ducts

DEFF Research Database (Denmark)

Ankorina-Stark, I; Amstrup, J; Novak, I

2002-01-01

by hormones/agonists affecting pancreatic secretion. Whole pancreas, pure pancreatic acini and ducts were obtained from rats and used for RT-PCR and Western blot analysis, immunohistochemistry and intracellular Ca2+ measurements using Fura-2. RT-PCR analysis indicated Na+/Ca2+-exchanger isoforms NCX1.......3 and NCX1.7 in acini and pancreas. Western blot with NCX1 antibody identified bands of 70, 120 and 150 kDa in isolated ducts, acini and pancreas. Immunofluorescence experiments showed the Na+/Ca2+ exchanger on the basolateral membrane of acini and small intercalated/intralobular ducts, but in larger...

Hodgkin's lymphoma-related vanishing bile duct syndrome: A case report and literature review

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Kiong-Ming Wong

2013-11-01

Full Text Available We report the case of a 38-year-old man who developed vanishing bile duct syndrome in association with Hodgkin's lymphoma. He was noted to have cervical lymphadenopathy and marked elevation of total serum bilirubin at diagnosis. He achieved complete remission with normalization of serum bilirubin after eight courses of Adriamycin, bleomycin, vinblastine, and dacarbazine chemotherapy followed with autologous hematopoietic cell transplantation. Consecutive liver biopsies performed at diagnosis and at the stage of complete remission revealed the disappearance and regeneration of interlobular bile ducts, respectively. Our case provides pathological evidence that Hodgkin's lymphoma-related vanishing bile duct syndrome is a reversible bile duct injury disease. Bilirubin is a reliable serum marker to monitor the treatment response of these cases. The mechanism to develop hyperbilirubinemia with vanishing bile duct in such a case of Hodgkin's lymphoma remains to be studied. A literature review was carried out.