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Sample records for perforated electrode plate

  1. Optimization of geometrical characteristics of perforated plates

    International Nuclear Information System (INIS)

    Radisavljevic, Igor; Balos, Sebastian; Nikacevic, Milutin; Sidjanin, Leposava

    2013-01-01

    Highlights: ► Perforated plate are tested against 12.7 mm API projectile. ► Perforations similar to the projectile diameter offer more efficient core fracture. ► Larger perforations gave a more efficient core fragmentation. ► SEM microscopy analysis has shown a ductile fracture mode at impact point. - Abstract: In this paper, an attempt was made to design effective non-homogenous armor in form of perforated plate mounted at close distance from basic armor plate. Perforated plate with three perforation diameters: 9, 10 and 11 mm, two ligaments length: 3.5 and 4.5 mm ligaments, set at 0° and 28° angles, were combined to 13 mm basic plate and tested against 12.7 mm API ammunition. It has been shown that larger perforations gave a more efficient core fragmentation, while angled specimens were the only ones that offer full protection against five API shots when the perforated plate was placed at 100 mm from the basic plate. Perforations that are similar in size to the penetrating core diameter offer a more efficient core fracture, leading to a faster fragment separation. This may enable a smaller distance between the add-on perforated and basic plate to be used. Scanning electron microscopy analysis has shown a ductile fracture mode at impact point, with hardness values on plate basic level. On the other hand, a brittle fracture mode with a rise in local hardness measured near impact point is a result of intensive high speed plastic deformation produced by bending stresses. A drop in local hardness measured near impact point, may be the result of intensive cracking that occur due to repeated projectile impact

  2. Micro direct methanol fuel cell with perforated silicon-plate integrated ionomer membrane

    DEFF Research Database (Denmark)

    Larsen, Jackie Vincent; Dalslet, Bjarke Thomas; Johansson, Anne-Charlotte Elisabeth Birgitta

    2014-01-01

    This article describes the fabrication and characterization of a silicon based micro direct methanol fuel cell using a Nafion ionomer membrane integrated into a perforated silicon plate. The focus of this work is to provide a platform for micro- and nanostructuring of a combined current collector...... at a perforation ratio of 40.3%. The presented fuel cells also show a high volumetric peak power density of 2 mW cm−3 in light of the small system volume of 480 μL, while being fully self contained and passively feed....... and catalytic electrode. AC impedance spectroscopy is utilized alongside IV characterization to determine the influence of the plate perforation geometries on the cell performance. It is found that higher ratios of perforation increases peak power density, with the highest achieved being 2.5 mW cm−2...

  3. Comparison of Thermal Performances between Low Porosity Perforate Plate and Flat Plate Solar Air Collector

    Science.gov (United States)

    Chan, Hoy-Yen; Vinson, A. A.; Baljit, S. S. S.; Ruslan, M. H.

    2018-04-01

    Flat plate solar air collector is the most common collector design, which is relatively simpler to fabricate and lower cost. In the present study, perforated plate solar collector was developed to improve the system thermal performance. A glazed perforated plate of 6mm holes diameter with square geometry was designed and installed as the absorber of the collector. The influences of solar radiation intensity and mass flow rate on the thermal performance were investigated. The perforated collector was compared with the flat plate solar collector under the same operating conditions. The highest values of thermal efficiency in this study for the perforated plate (PP) and the flat plate (FP) solar collectors were 59% and 36% respectively, at solar radiation intensity of 846 Wm-2 and mass flow rate of 0.02 kgs-1. Furthermore, PP collector gave better thermal performance compared to FP collector; and compared to previous studies, the present perforated design was compatible with the flat plate with double pass designs.

  4. Energy Analysis of Solar Collector With perforated Absorber Plate

    Directory of Open Access Journals (Sweden)

    Ammar A. Farhan

    2017-09-01

    Full Text Available The thermal performance of three solar collectors with 3, 6 mm and without perforation absorber plate was assessed experimentally. The experimental tests were implemented in Baghdad during the January and February 2017. Five values of airflow rates range between 0.01 – 0.1 m3/s were used through the test with a constant airflow rate during the test day. The variation of the following parameters air temperature difference, useful energy, absorber plate temperature, and collector efficiency was recorded every 15 minutes. The experimental data reports that the increases the number of absorber plate perforations with a small diameter is more efficient rather than increasing the hole diameter of the absorber plate with decreasing the perforation numbers. Maximum air temperature difference throughout the solar collector with 3, 6 mm perforations and without perforations are 17, 15, and 12 oC, respectively. Also, it can be concluded that the energy gained from the solar collector with 3 mm perforation absorber plate is 28.2 % more than the energy gained from solar collector without holes per day for 0.1 m3/s airflow rate. The maximum values of the thermal performance curves are 0.67, 0.64, and 0.56 for the solar collector with 3, 6 mm, and without perforations, respectively.

  5. Low-energy plasma-cathode electron gun with a perforated emission electrode

    Science.gov (United States)

    Burdovitsin, Victor; Kazakov, Andrey; Medovnik, Alexander; Oks, Efim; Tyunkov, Andrey

    2017-11-01

    We describe research of influence of the geometric parameters of perforated electrode on emission parameters of a plasma cathode electron gun generating continuous electron beams at gas pressure 5-6 Pa. It is shown, that the emission current increases with increasing the hole diameters and decreasing the thickness of the perforated emission electrode. Plasma-cathode gun with perforated electron can provide electron extraction with an efficiency of up to 72 %. It is shown, that the current-voltage characteristic of the electron gun with a perforated emission electrode differs from that of similar guns with fine mesh grid electrode. The plasma-cathode electron gun with perforated emission electrode is used for electron beam welding and sintering.

  6. Prediction of inelastic behavior and creep-fatigue life of perforated plates

    International Nuclear Information System (INIS)

    Igari, Toshihide; Setoguchi, Katsuya; Nakano, Shohki; Nomura, Shinichi

    1991-01-01

    Prediction methods of macroscopic and local stress-strain behavior of perforated plates in plastic and creep regime which are proposed by the authors are applied to the inelastic analysis and creep-fatigue life prediction of perforated cylinder subjected to cyclic thermal stress. Stress-strain behavior of perforated cylinder is analyzed by modeling the perforated portion to cylinder with equivalent-solid-plate properties. Creep-fatigue lives at around a hole of perforated plates are predicted by using the local stress-strain behavior and are compared with experimentally observed lives. (author)

  7. An Experimentally Validated Numerical Modeling Technique for Perforated Plate Heat Exchangers.

    Science.gov (United States)

    White, M J; Nellis, G F; Kelin, S A; Zhu, W; Gianchandani, Y

    2010-11-01

    Cryogenic and high-temperature systems often require compact heat exchangers with a high resistance to axial conduction in order to control the heat transfer induced by axial temperature differences. One attractive design for such applications is a perforated plate heat exchanger that utilizes high conductivity perforated plates to provide the stream-to-stream heat transfer and low conductivity spacers to prevent axial conduction between the perforated plates. This paper presents a numerical model of a perforated plate heat exchanger that accounts for axial conduction, external parasitic heat loads, variable fluid and material properties, and conduction to and from the ends of the heat exchanger. The numerical model is validated by experimentally testing several perforated plate heat exchangers that are fabricated using microelectromechanical systems based manufacturing methods. This type of heat exchanger was investigated for potential use in a cryosurgical probe. One of these heat exchangers included perforated plates with integrated platinum resistance thermometers. These plates provided in situ measurements of the internal temperature distribution in addition to the temperature, pressure, and flow rate measured at the inlet and exit ports of the device. The platinum wires were deposited between the fluid passages on the perforated plate and are used to measure the temperature at the interface between the wall material and the flowing fluid. The experimental testing demonstrates the ability of the numerical model to accurately predict both the overall performance and the internal temperature distribution of perforated plate heat exchangers over a range of geometry and operating conditions. The parameters that were varied include the axial length, temperature range, mass flow rate, and working fluid.

  8. Experimental investigation of the unsteady one-phase flow through perforated plates

    International Nuclear Information System (INIS)

    Casadei, F.

    1982-07-01

    The flow of the coolant through the perforated dip-plate during a hypothetical core-disruptive accident in a sodium-cooled fast breeder reactor was simulated in a one-dimensional model. Several experiments with water as fluid and with various perforation ratios of the dip-plate and different initial heights of the fluid head over the dip plate were run. The pressure drop through the dip-plate and the forces acting on the dip-plate and on the upper plug of the reactor vessel in a wide range of the Reynolds and Strouhal numbers were measured. The flow pattern downstreams the perforated plate was filmed with high-speed cameras. The resistance coefficients for the unsteady flow of the coolant through the perforated plate were obtained as a function of the acceleration. The forces acting on the upper plug and their time integral were compared with those acting on the dip-plate. Finally, using the high-speed film pictures the formation of fluid jets downstream the dip-plate was investigated. (orig.) [de

  9. Perforated plates for cryogenic regenerators and method of fabrication

    International Nuclear Information System (INIS)

    Hendricks, J.B.

    1994-01-01

    Perforated plates having very small holes with a uniform diameter throughout the plate thickness are prepared by a open-quotes wire drawingclose quotes process in which a billet of sacrificial metal is disposed in an extrusion can of the plate metal, and the can is extruded and restacked repeatedly, converting the billet to a wire of the desired hole diameter. At final size, the rod is then sliced into wafers, and the wires are removed by selective etching. This process is useful for plate metals of interest for high performance regenerator applications, in particular, copper, niobium, molybdenum, erbium, and other rare earth metals. Er 3 Ni, which has uniquely favorable thermophysical properties for such applications, may be incorporated in regions of the plates by providing extrusion cans containing erbium and nickel metals in a stacked array with extrusion cans of the plate metal, which may be copper. The array is heated to convert the erbium and nickel metals to Er 3 Ni. Perforated plates having two sizes of perforations, one of which is small enough for storage of helium, are also disclosed. 10 figures

  10. Theroretical modelling of the plate-tubes coupling in the hydroelasticity of the perforated plates

    International Nuclear Information System (INIS)

    Dzhupanov, V.A.; Manoach, E.S.

    1983-01-01

    In the previous investigations on the perforated plate hydroelasticity the problem of the plates-tubes-liquid interaction in the process of the general structural vibration is stated. But the interaction of the vibrating plates with the tubes, passing through them, is taken into account considering the tubes only as absolutely rigid supports. This is one of the possible technical realizations. In the present article the case when the tubes are taking part in the plate motion (vibration) is studied. Two circular perforated plates are supported by the absolutely rigid wall of the modelled roundcircular reactor barrel. The distance between the plates is given. They are connected by tubes, passing through, and clamped into the perforation holes. The plates and the tubes are made by any elastic HOOKIAN material. The volume between the two plates and outwardly to the tubes, but intrinsically of the barrel is filled by ideal, compressible and heavy liquid. Evidently the liquid volume is multiconnected one. The free vibration of the whole system is considered with the purposes: i) to give a theoretical model of the plates-tubes-liquid interaction including governing equations and boundary conditions; ii) to trace the solution of the eigen-value problem for the modelled structure; iii) to underline the engineering sides of the modelling process. (orig./GL)

  11. Prediction of inelastic behavior and creep-fatigue life of perforated plates

    International Nuclear Information System (INIS)

    Igari, Toshihide; Yamauchi, Masafumi; Nomura, Shinichi.

    1992-01-01

    Prediction methods of macroscopic and local stress-strain behaviors of perforated plates in plastic and creep regime are proposed in this paper, and are applied to the creep-fatigue life prediction of perforated plates. Both equivalent-solid-plate properties corresponding to the macroscopic behavior and the stress-strain concentration around a hole were obtained by assuming the analogy between plasticity and creep and also by extending the authors' proposal in creep condition. The perforated plates which were made of Hastelloy XR were subjected to the strain-controlled cyclic test at 950degC in air in order to experimentally obtain the macroscopic behavior such as the cyclic stress-strain curve and creep-fatigue life around a hole. The results obtained are summarized as follows. (1) The macroscopic behavior of perforated plates including cyclic stress-strain behavior and relaxation is predictable by using the proposed method in this paper. (2) The creep-fatigue life around a hole can be predicted by using the proposed method for stress-strain concentration around a hole. (author)

  12. Directional bending wave propagation in periodically perforated plates

    DEFF Research Database (Denmark)

    Andreassen, Erik; Manktelow, Kevin; Ruzzene, Massimo

    2015-01-01

    We report on the investigation of wave propagation in a periodically perforated plate. A unit cell with double-C perforations is selected as a test article suitable to investigate two-dimensional dispersion characteristics, group velocities, and internal resonances. A numerical model, formulated...... using Mindlin plate elements, is developed to predict relevant wave characteristics such as dispersion, and group velocity variation as a function of frequency and direction of propagation. Experimental tests are conducted through a scanning laser vibrometer, which provides full wave field information...... for the design of phononic waveguides with directional and internal resonant characteristics....

  13. Critical impact energy for the perforation of metallic plates

    International Nuclear Information System (INIS)

    Aly, S.Y.; Li, Q.M.

    2008-01-01

    This paper investigates the empirical formulae used in engineering practice to predict the critical perforation energy of metallic plates struck by rigid projectiles in the sub-ordnance regime. Main factors affecting the critical perforation energy are identified and valid conditions for each empirical formula are compared. Dimensional analysis is conducted to show the dependence of the non-dimensional critical impact energy on other influential non-dimensional numbers. Available empirical formulae are re-expressed in non-dimensional forms. A modified Jowett/AEA equation is proposed to predict the critical perforation energy of a flat-ended short projectile. The present work increases the confidence of using these empirical formulae and can be regarded as a quick guide for ballistic protection design of metallic shields and steel armour plates

  14. Stress state in perforated plates

    International Nuclear Information System (INIS)

    Visner, J.

    1977-01-01

    The method is described of photoelastic measurement of stress concentration factors (s.c.f) in plates perforated by a square, triangular and diagonal grid of circular holes and loaded by uniaxial or biaxial tensile stress. A loading equipment which was developed and its modifications are described. Stress concentration factors found are compared with theoretical and experimental results given in references. (author)

  15. Free vibration analysis of perforated plate with square penetration pattern using equivalent material properties

    Energy Technology Data Exchange (ETDEWEB)

    Jhung, Myung Ho [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of); Jeong, Kyeong Hoon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-06-15

    In this study, the natural frequencies of the perforated square plate with a square penetration pattern are obtained as a function of ligament efficiency using the commercial finite-element analysis code ANSYS. In addition, they are used to extract the effective modulus of elasticity under an assumption of a constant Poisson's ratio. The effective modulus of elasticity of the fully perforated square plate is applied to the modal analysis of a partially perforated square plate using a homogeneous finite-element analysis model. The natural frequencies and the corresponding mode shapes of the homogeneous model are compared with the results of the detailed finite-element analysis model of the partially perforated square plate to check the validity of the effective modulus of elasticity. In addition, the theoretical method to calculate the natural frequencies of a partially perforated square plate with fixed edges is suggested according to the Rayleigh-Ritz method.

  16. Free vibration analysis of perforated plate with square penetration pattern using equivalent material properties

    Directory of Open Access Journals (Sweden)

    Myung Jo Jhung

    2015-06-01

    Full Text Available In this study, the natural frequencies of the perforated square plate with a square penetration pattern are obtained as a function of ligament efficiency using the commercial finite-element analysis code ANSYS. In addition, they are used to extract the effective modulus of elasticity under an assumption of a constant Poisson's ratio. The effective modulus of elasticity of the fully perforated square plate is applied to the modal analysis of a partially perforated square plate using a homogeneous finite-element analysis model. The natural frequencies and the corresponding mode shapes of the homogeneous model are compared with the results of the detailed finite-element analysis model of the partially perforated square plate to check the validity of the effective modulus of elasticity. In addition, the theoretical method to calculate the natural frequencies of a partially perforated square plate with fixed edges is suggested according to the Rayleigh–Ritz method.

  17. Pool Boiling Enhancement of R-123 Using Perforated Plates

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Nae-Hyun [Incheon Nat’l Univ., Incheon(Korea, Republic of)

    2016-05-15

    In this study, we investigate the pool boiling enhancement caused by perforated plates on top of a smooth surface. We conduct tests using R-123 at atmospheric pressure. It was shown that perforated plates significantly enhanced the pool boiling of the smooth surface. The reason may be attributed to the increased bubble contact area between the plates. The results showed that the enhancement ratio was dependent on the heat flux. At high heat flux, the enhancement ratio increased as the porosity increased. However, at low heat flux, the enhancement ratio decreased as the porosity increased. For the present investigation, the optimum configuration had a pore diameter of 2.0 mm, pore pitch of 2.5 mm×5.0 mm or 5.0 mm×5.0 mm, and a gap width of 0.5 mm, which yielded heat-transfer coefficients that are close to those of GEWA-T. The optimum porosity for R-123 was significantly larger than that of water or ethanol. The reason for this may be the large liquid-to-vapor density ratio along with the small latent heat of vaporization of R-123. The perforated plates yielded smaller boiling hysteresis compared with that of the smooth surface.

  18. Equivalent properties for perforated plates. An analytical approach

    International Nuclear Information System (INIS)

    Cepkauskas, M.M.; Yang Jianfeng

    2005-01-01

    Structures that contain perforated plates have been a subject of interest in the Nuclear Industry. Steam generators, condensers and reactor internals utilize plates containing holes which act as flow holes or separate structures from flow by using a 'tube bank' design. The equivalent plate method has been beneficial in analyzing perforate plates. Details are found in various papers found in the bibliography. In addition the ASME code addresses perforated plates in Appendix A-8000, but is limited to a triangular hole pattern. This early work performed in this field utilized test data and analytical approaches. This paper is an examination of an analytical approach for determining equivalent plate mechanical and thermal properties. First a patch of the real plate is identified that provides a model for the necessary physical behavior of the plate. The average strain of this patch is obtained by first applying simplified one dimensional mechanical load to the patch, determining stress as a function of position, converting the stress to strain and then integrating the strain over the patch length. This average strain is then equated to the average strain of an equivalent fictitious rectangular patch. This results in obtaining equivalent Young's Modulus and Poison's Ratio for the equivalent plate in all three orthogonal directions. The corresponding equivalent shear modulus in all three directions is then determined. An orthotropic material stress strain matrix relationship is provided for the fictitious properties. By equating the real average strain with the fictitious average strain in matrix form, a stress multiplier is found to convert average fictitious stress to average real stress. This same type of process is repeated for heat conduction coefficients and coefficients of thermal expansion. Results are provided for both a square and triangular hole pattern. Reasonable results are obtained when comparing the effective Young's Modulus and Poison's Ratio with ASME

  19. Experimental investigation of the unsteady two-phase flow through perforated plates

    International Nuclear Information System (INIS)

    Tartaglia, G.P.

    1985-07-01

    The coolant flow across the perforated dip-plate during a hypothetical core disruptive accident (HCDA) in a liquid metal fast breeder reactor was simulated in a one-dimensional model. Experiments with a water-air mixture as fluid were run by varying the following parameters: geometry of the dip-plate (perforation ratio, number of the holes), height of the fluid head over the dip-plate, air volumetric fraction, size of the air bubbles, acceleration of the fluid. The pressure drop across the dip-plate, the forces acting on the dip-plate and on the upper plate, acceleration and displacement of the piston, the air volumetric fraction and the size of the air bubbles were measured in a wide range of Strouhal and acceleration numbers. The flow pattern downstream the dip-plate was filmed with a high-speed camera. The following correlations were investigated: resistance coefficients as a function of the acceleration and Strouhal number, time delay of the force on the upper plate as a function of the cavitation number, and forces and impulses acting on the upper plate compared with those acting on the dip-plate. Finally, using high-speed film pictures, the formation of fluid jets downstream the dip-plate was investigated. The following relations were obtained: displacement of the mixture surface and of the jets as a function of the perforation ratio and of the air volumetric fraction, and cavitation volume as a function of the cavitation number. (orig.) [de

  20. Prediction of macroscopic and local stress-strain behaviors of perforated plates under primary and secondary creep conditions

    International Nuclear Information System (INIS)

    Igari, Toshihide; Tokiyoshi, Takumi; Mizokami, Yorikata

    2000-01-01

    Prediction methods of macroscopic and local creep behaviors of perforated plates are examined in order to apply these methods to the structural design of perforated structures such as heat exchangers used in elevated temperatures. Both primary and secondary creeps are considered for predicting macroscopic and local creep behaviors of perorated plates which are made of actual structural materials. Both uniaxial and multiaxial loading of perforated plates are taken into consideration. The concept of effective stress is applied to the prediction of macroscopic creep behaviors of perforated plates, and the predicted results are compared with the numerical results by FEM for the unit section of perorated plated under creep, in order to confirm the propriety of the proposed method. Based on the idea that stress exponents in creep equations govern the stress distribution of perforated plates, a modified Neuber's rule is used for predicting local stress and strain concentrations. The propriety of this prediction method is shown through a comparison of the prediction with the numerical results by FEM for the unit section of perforated plates under creep, and experimental results by the Moire method. (author)

  1. Oblique Wave-Induced Responses of A VLFS Edged with A Pair of Inclined Perforated Plates

    Science.gov (United States)

    Cheng, Yong; Ji, Chun-yan; Zhai, Gang-jun; Oleg, Gaidai

    2018-03-01

    This paper is concerned with the hydroelastic responses of a mat-like, rectangular very large floating structure (VLFS) edged with a pair of horizontal/inclined perforated anti-motion plates in the context of the direct coupling method. The updated Lagrangian formulae are applied to establish the equilibrium equations of the VLFS and the total potential formula is employed for fluids in the numerical model including the viscous effect of the perforated plates through the Darcy's law. The hybrid finite element-boundary element (FE-BE) method is implemented to determine the response reduction of VLFS with attached perforated plates under various oblique incident waves. Also, the numerical solutions are validated against a series of experimental tests. The effectiveness of the attached perforated plates in reducing the deflections of the VLFS can be significantly improved by selecting the proper design parameters such as the porous parameter, submergence depth, plate width and inclination angle for the given sea conditions.

  2. Capacity limits in columns pulsed with stain steel perforated plates

    International Nuclear Information System (INIS)

    Maset, E.R.; Acosta, E.; Di Piano, M.; Maymo, J.A.

    1987-01-01

    This paper includes part of the second stage of the pulsed columns development program, using a water-nitric acid system as continuous phase and tri-n-butyl phosphate dissolved in kerosene at 30% v/v as disperse phase. Two kits of different geometry perforated plates (different diameter of perforation and free area percentage) were used. Due to the affinity importance of the plates' material with the continuous phase, in all the cases the continuous aqueous phase was used. The relation of flows varied, thus obtaining in each case a curve of characteristic 'flood'. The influence of the geometrical variables, the relation of flows, the medium acidity and the pulse's amplitude was applied in the capacity of the column. Besides, the dimensional correlation of Swift W.H. on the results obtained from 'flood' with both kits of plates to relate flows 1:1 and a minimum deviation was observed. (Author)

  3. Stress and displacement analysis of a core plate, i.e. grid-perforated plate compound, modelled as an equivalent beam system

    International Nuclear Information System (INIS)

    Frank, R.; Engel, R.

    1979-01-01

    The core support plate is a very important component of the reactor pressure vessel internals. Therefore, an exact stress analysis is desired. This analysis will cause high computer costs with a detailed FEM-model because of the complexity of this compound system. In this paper, a method is suggested to solve the problem with a much cheaper beam element model. The main problem is to establish an equivalent beam system with nearly the same stiffness property as the perforated circular plate stiffened by a grid. Furthermore, the system must allow to determine the maximum stresses with sufficient accuracy. The calculation of the equivalent beam stiffness is based on the analysis of perforated plates by T. SLOT and W.J. O'DONNELL. This analysis method utilizes the concept of the equivalent solid plate. In this method, the perforated plate is replaced by a solid one which is geometrically similar to the perforated plate but has modified values of the elastic constants. The simple equivalent beam system of one half of the core support plate (symmetry) was loaded with a pressure difference and stresses and displacements were analysed. After that, these results were compared with the stress and displacement analysis of a part of the real structure. This substructure was discretized by three-dimensional 20-node brick-elements. The comparison of the results of the two models shows that the stresses and displacements, calculated with the simple beam model, are in good agreement with those of the real structure. (orig.)

  4. Equivalent material properties of perforated plate with triangular or square penetration pattern for dynamic analysis

    International Nuclear Information System (INIS)

    Jhung, Myung Jo; Jo, Jong Chull

    2006-01-01

    For a perforated plate, it is challenging to develop a finite element model due to the necessity of the fine meshing of the plate, especially if it is submerged in fluid. This necessitates the use of a solid plate with equivalent material properties. Unfortunately, the effective elastic constants suggested by the ASME code are deemed not valid for a model analysis. Therefore, in this study the equivalent material properties of a perforated plate are suggested by performing several finite element analyses with respect to the ligament efficiencies

  5. Numerical analysis of the flow field in a sloshing tank with a horizontal perforated plate

    Science.gov (United States)

    Jin, Heng; Liu, Yong; Li, Huajun; Fu, Qiang

    2017-08-01

    Liquid sloshing is a type of free surface flow inside a partially filled water tank. Sloshing exerts a significant effect on the safety of liquid transport systems; in particular, it may cause large hydrodynamic loads when the frequency of the tank motion is close to the natural frequency of the tank. Perforated plates have recently been used to suppress the violent movement of liquids in a sloshing tank at resonant conditions. In this study, a numerical model based on OpenFOAM (Open Source Field Operation and Manipulation), an open source computed fluid dynamic code, is used to investigate resonant sloshing in a swaying tank with a submerged horizontal perforated plate. The numerical results of the free surface elevations are first verified using experimental data, and then the flow characteristics around the perforated plate and the fluid velocity distribution in the entire tank are examined using numerical examples. The results clearly show differences in sloshing motions under first-order and third-order resonant frequencies. This study provides a better understanding of the energy dissipation mechanism of a horizontal perforated plate in a swaying tank.

  6. Two-dimensional simulations of steady perforated-plate stabilized premixed flames

    KAUST Repository

    Altay, H. Murat

    2010-03-17

    The objective of this work is to examine the impact of the operating conditions and the perforated-plate design on the steady, lean premixed flame characteristics. We perform two-dimensional simulations of laminar flames using a reduced chemical kinetics mechanism for methane-air combustion, consisting of 20 species and 79 reactions. We solve the heat conduction problem within the plate, allowing heat exchange between the gas mixture and the solid plate. The physical model is based on a zero-Mach-number formulation of the axisymmetric compressible conservation equations. The results suggest that the flame consumption speed, the flame structure, and the flame surface area depend significantly on the equivalence ratio, mean inlet velocity, the distance between the perforated-plate holes and the plate thermal conductivity. In the case of an adiabatic plate, a conical flame is formed, anchored near the corner of the hole. When the heat exchange between themixture and the plate is finite, the flame acquires a Gaussian shape stabilizing at a stand-off distance, that grows with the plate conductivity. The flame tip is negatively curved; i.e. concave with respect to the reactants. Downstream of the plate, the flame base is positively curved; i.e. convex with respect to the reactants, stabilizing above a stagnation region established between neighboring holes. As the plate\\'s thermal conductivity increases, the heat flux to the plate decreases, lowering its top surface temperature. As the equivalence ratio increases, the flame moves closer to the plate, raising its temperature, and lowering the flame stand-off distance. As the mean inlet velocity increases, the flame stabilizes further downstream, the flame tip becomes sharper, hence raising the burning rate at that location. The curvature of the flame base depends on the distance between the neighboring holes; and the flame there is characterized by high concentration of intermediates, like carbon monoxide. © 2010 Taylor

  7. Coupled oscillations of flow along a perforated plate

    International Nuclear Information System (INIS)

    Celik, E.; Rockwell, D.

    2004-01-01

    Turbulent shear flow past a perforated plate bounded by a closed cavity can give rise to highly coherent oscillations, which have a wavelength of the order of the plate length. The present investigation focuses on the coupling between unsteady events on either side of the plate when the oscillations are self-sustaining. A cinema technique of high-image-density particle image velocimetry, which provides a space-time representation of the unsteadiness at a large number of locations over entire planes, is employed to characterize the distinctively different patterns of flow structure on the back (low-speed) side of the plate relative to those on the front (high-speed) side. Global cross-spectral analysis leads to patterns of spectral peaks and phase variations, along and across the plate. This approach, along with complementary types of image evaluation, delineates the physics of the oscillations, which include downstream propagating disturbances along either side of the plate and a coherent region of unsteadiness at its trailing-edge. On the backside of the plate, a sequence of upstream-oriented, pulsatile jets are formed, and the time-averaged flow pattern is a counterflow wall jet

  8. A study on the load distribution factor in the perforated square plate with elastic support

    International Nuclear Information System (INIS)

    Lee, Y.S.; Yim, J.S.

    1993-01-01

    The load distribution factor in the perforated square plate supporting by angle shape legs under concentrated load acting at arbitrary points through elastic media is calculated. For the calculation the perforated plate was converted into an orthotropic plate using the method suggested by J.B. Mahoney. The deflection for the calculation of the load distribution factor was obtained from the auxiliary plate which was extended both sides of the plate and it was compared with the results from ANSYS calculation. With this deflection, the calculation of the load distribution factor was performed. The result shows that the load distribution factor at the periphery of the plate is larger than that of in the central location. This load distribution factor could be used for re-distribution of the applied load in more accurate analysis of the plate as well as in the analysis of the elastic media as the load factor. (author)

  9. 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...

  10. Axial holdup in pulsed perforated-plate column of pulser feeder type, (2)

    International Nuclear Information System (INIS)

    Ikeda, Hidematsu; Suzuki, Atsuyuki; Kiyose, Ryohei.

    1987-01-01

    In mathematical models for a pulsed perforated-plate column, the dispersed phase holdup has been considered to be uniform throughout the length of the column, but fairly recently it is treated as being nonuniform. In the previous paper, the axial holdup data were obtained in the dispersed aqueous and the dispersed organic modes. Experimental results showed that the axial holdup data become nonuniform throughout the column. It was also found that both of the plate type and the operation mode affected the axial holdup distribution. The present work is an attempt to formulate the axial holdup by means of a heuristic selforganization method that provides a nonlinear prediction model of complex system, since the holdup data did not directly show so significant trend as to formulate the axial holdup. The Group Method of Data Handling (GMDH) is used for this purpose. The GMDH can be used for selection and synthesis of input variables concerned with the axial holdup for the pulsed perforated-plate column. The axial holdup data have been successfully correlated and the identification models could be useful in discussing mathematical models. (author)

  11. Stress analysis of perforated plates and plates with single and clustered nozzles

    International Nuclear Information System (INIS)

    Hulbert, L.E.; Hopper, A.T.; Rybicki, E.F.

    1976-01-01

    It is well known that stress distributions around a hole in a plate are drastically increased if there are other holes in the plate sufficiently near. Such stress interaction effects must be analyzed and accounted for in the design of a plate containing multiple perforations. Computer programs have been developed for the accurate analysis of the in-plane stresses of arbitrary multiholed plates. Stress interactions also occur between closely spaced nozzles attached to pressure vessels such as nuclear reactor vessels. Results of the investigations carried out during the second year of the research program are summarized. The first section of the report describes the structures analyzed, the loadings on these structures, and the mathematical statements of these problems. The second section explains the analysis techniques employed. The third section deals with the numerical results obtained for all of the problems solved. This section also gives a complete statement of each problem and the series of trial functions used to solve each nozzle-plate problem. Several appendices are also included. These appendices are intended to be users' manuals for the computer codes used in this research effort but which are not explained in the literature. Appendix A treats program TABLES while Appendix B explains the use of PEBBLES. Appendix C is the users' manual for program INTRTIE which is a large program actually consisting of six individual programs. Appendix D discusses the changes in the input data to program NONLIN to obtain certain input data for INTRTIE. Finally, Appendix E treats a small program called CONVERT which also generates input data for INTRTIE

  12. Reliability assessment of stress concentration performance state for a perforated composite plate under traction

    Directory of Open Access Journals (Sweden)

    Jabbouri A.

    2012-07-01

    Full Text Available Considering a perforated sandwich plate made from two elastic homogenous and isotropic layers, and having a square hole, reliability assessment of stress concentration limit state for which the stress should not exceed a given threshold is performed in this work. Assuming that the plate dimensions and the applied loading are deterministic, focus is done on the square hole centre position and edge length considered to be random variables. The means and the standard deviations of these variables are assumed to be known, but no information is so far available about their densities of probabilities. To assess reliability of the performance state, reliability analysis known methods are applied to a response surface representation of the stress concentration factor of the perforated plate which is obtained through quadratic polynomial regression of finite element results. A parametric study is performed regarding the influence of the distributions of probabilities chosen to model the hole dimensions uncertainties. It is shown that the probability of failure depends largely on the selected densities of probabilities.

  13. Countercurrent air/water and steam/water flow above a perforated plate. Report for October 1978-October 1979

    International Nuclear Information System (INIS)

    Hsieh, C.; Bankoff, S.G.; Tankin, R.S.; Yuen, M.C.

    1980-11-01

    The perforated plate weeping phenomena have been studied in both air/water and steam/cold water systems. The air/water experiment is designed to investigate the effect of geometric factors of the perforated plate on the rate of weeping. A new dimensionless flow rate in the form of H star is suggested. The data obtained are successfully correlated by this H star scaling in the conventional flooding equation. The steam/cold water experiment is concentrated on locating the boundary between weeping and no weeping. The effects of water subcooling, water inlet flow rate, and position of water spray are investigated. Depending on the combination of these factors, several types of weeping were observed. The data obtained at high water spray position can be related to the air/water flooding correlation by replacing the stream flow rate to an effective stream flow rate, which is determined by the mixing efficiency above the plate

  14. Mechanisms of stabilization and blowoff of a premixed flame downstream of a heat-conducting perforated plate

    KAUST Repository

    Kedia, Kushal S.; Ghoniem, Ahmed F.

    2012-01-01

    The objective of this work is to investigate the flame stabilization mechanism and the conditions leading to the blowoff of a laminar premixed flame anchored downstream of a heat-conducting perforated-plate/multi-hole burner, with overall nearly

  15. Equivalent Young's Modulus of Perforated Shell with Square Penetration Pattern

    Energy Technology Data Exchange (ETDEWEB)

    Jhung, Myung Jo; Ryu, Yong Ho [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2011-05-15

    The analysis of a plate or shell perforated with a large number of holes, by finite element method for instance, was a very costly and time-consuming technique which solves only one particular problem. But it is possible to model the perforated plate or shell and to analyze it and it is no more time-consuming theses days due to the rapid development of the computer and software. However, if a perforated plate or shell is submerged in fluid it is almost impossible to model and analyze it as is and the fluid at the same time, which is needed to investigate the effect of the fluid structure interaction. The simplest way to avoid time consuming and costly analysis of perforated plate or shell submerged in fluid is to replace the perforated plate or shell by an equivalent solid one considering weakening effect of holes. Many authors have proposed experimental or theoretical method to solve this problem for the plate. Slot and O'Donnell determined the effective elastic constants for the thick perforated plates by equating strains in the equivalent solid material to the average strains in the perforated material. O'Donnell also presented those of thin perforated plates. These results are implemented in Article A-8000 of Appendix A to the ASME code Section III, which contains a method of analysis for flat perforated plates when subjected to directly applied loads or loadings resulting from structural interaction with adjacent members. Unfortunately the effective elastic constants for the perforated shell are not found in any references. Therefore in this study the modal characteristics of the perforated shell are investigated and the equivalent material properties of perforated shell are suggested by performing several finite element analyses with respect to the ligament efficiencies

  16. Development and validation of a CFD based methodology to estimate the pressure loss of flow through perforated plates

    International Nuclear Information System (INIS)

    Barros Filho, Jose A.; Navarro, Moyses A.; Santos, Andre A.C. dos; Jordao, E.

    2011-01-01

    In spite of the recent great development of Computational Fluid Dynamics (CFD), there are still some issues about how to assess its accurateness. This work presents the validation of a CFD methodology devised to estimate the pressure drop of water flow through perforated plates similar to the ones used in some reactor core components. This was accomplished by comparing the results of CFD simulations against experimental data of 5 perforated plates with different geometric characteristics. The proposed methodology correlates the experimental data within a range of ± 7.5%. The validation procedure recommended by the ASME Standard for Verification and Validation in Computational Fluid Dynamics and Heat Transfer-V and V 20 is also evaluated. The conclusion is that it is not adequate to this specific use. (author)

  17. Residual strains in a stainless steel perforated plate subjected to reverse loading at high temperature

    International Nuclear Information System (INIS)

    Durelli, A.J.; Buitrago, J.

    1974-01-01

    An investigation was made to determine strains in a stainless steel perforated plate subjected to a temperature of 1100 0 F and to a successively applied tensile and compressive in-plane loading sufficiently large to produce creep and plastic strains. The duration of the test was 1000 hours. Square grids of lines (at distance of 0.25 in.) and crossed-gratings (500 lines-per-inch) were engraved on both surfaces of the plate before the test. After the plate was unloaded and brought back to room temperature the grids were analyzed using traveling microscopes, and the gratings using the moire effect. Both Cartesian strains were determined from the moire isothetics along the axes of the plate, along the two lines tangent to the hole and parallel to those axes and along the edges of the plate. Grid measurements were made at specific points. The deformed shapes of the hole and of the plate are also given. It is estimated that strains larger than 0.001 can be determined with the techniques and methods used. (U.S.)

  18. Determination of stress multipliers for thin perforated plates with square array of holes

    International Nuclear Information System (INIS)

    Bhattacharya, A.; Murli, B.; Kushwaha, H.S.

    1991-01-01

    The peak stress multipliers are required to determine the maximum stresses in perforated plates for the realistic evaluation of their fatigue life. The Section III of ASME Boiler and Pressure Vessels Code does not provide any information about such multipliers to be used in thin perforated plates with square penetration pattern. Although such multipliers for membrane loadings are available in literature, they were obtained either by classical analysis or by photoelastic experiments and there is no significant finite element analysis in this area. Also it has been a common practice among designers to apply the same multipliers for loads producing bending type of stress. The stress multipliers in bending are lower than those in membrane. Therefore a reduction of resultant peak stress occurs if proper stress multipliers are used for bending. The present paper is aimed at developing a finite element technique which can be used for determining the peak stress multipliers in thin plates for membrane as well as bending loads. A quarter symmetric part of a 3 x 3 square array was chosen for the analysis. The results were obtained by computer programs PAFEC and COSMOS/M using 2-D plane stress elements for the membrane and degenerated 3-D shell element for the bending part. The results for the membrane are compared with Bailey, Hicks and Hulbert and with Meijers' finite element results for the bending part. A study was made at the initial stage by analysing a 6 x 6 square array to see the effect of holes beyond one pitch, which were left out by the 3 x 3 array and the effect of additional holes was found to be negligible. Therefore it was decided to carry out further analysis with 3 x 3 square array. Photoelastic experiments were also performed to validate the results obtained by theoretical analysis. (author)

  19. The Effect of Perforation on the Dynamics of a Flexible Panel

    Directory of Open Access Journals (Sweden)

    A. Putra

    2014-01-01

    Full Text Available Introduction of holes into plate-like structures is commonly found as one of the practical noise control measures to reduce sound radiation. However, perforation also reduces the panel stiffness and hence increases its vibration. The discussion on this effect is lacking and hence this paper discusses the dynamics of a perforated panel from the results obtained from Finite Element (FE model. Different hole geometries and arrangement are simulated to investigate their effect on the plate mobility. In general, it is found that increasing the perforation ratio increases the plate mobility. For a fixed perforation ratio, the mobility increases at high frequency (above 1 kHz for a smaller hole density in the plate. The plate with holes concentrated at the middle shows the largest increase of vibration around the plate centre compared to those uniformly distributed or away from the middle and concentrated at the plate edges. This is because as the hole separation becomes smaller, the reduction of the global stiffness around the mid area of the plate becomes greater. This also corresponds to the finding here that the mobility is greater at the vicinity of the hole. Different conditions of the plate edges are found to give consistent trend of the effect of perforation.

  20. Study Effect of Central Rectangular Perforation on the Natural Convection Heat Transfer in an Inclined Heated Flat Plate

    Directory of Open Access Journals (Sweden)

    Kadhum Audaa Jehhef

    2015-09-01

    Full Text Available Anumerical solutions is presented to investigate the effect of inclination angle (θ , perforation ratio (m and wall temperature of the plate (Tw on the heat transfer in natural convection from isothermal square flat plate up surface heated (with and without concentrated hole. The flat plate with dimensions of (128 mm length × (64 mm width has been used five with square models of the flat plate that gave a rectangular perforation of (m=0.03, 0.06, 0.13, 0.25, 0.5. The values of angle of inclination were (0o, 15o 30o 45o 60o from horizontal position and the values of wall temperature (50oC, 60 oC, 70 oC, 90 oC, 100oC. To investigate the temperature, boundary layer thickness and heat flux distributions; the numerical computation is carried out using a very efficient integral method to solve the governing equation. The results show increase in the temperature gradient with increase in the angle of inclination and the high gradient and high heat transfer coefficients located in the external edges of the plate, for both cases: with and without holed plate. There are two separation regions of heat transfer in the external edge and the internal edges. The boundary layer thickness is small in the external edge and high in the center of the plate and it decreases as the inclination angle of plate increases. Theoretical results are compared with previous result and it is found that the Nusslet numbers in the present study are higher by (22 % than that in the previous studies. And the results show good agreement in range of Raleigh number from 105 to 106.

  1. Axial mixing for both dispersed and continuous phases in pulsed perforated-plate extraction column by tracer co-injection method

    International Nuclear Information System (INIS)

    Ikeda, Hidematsu; Suzuki, Atsuyuki.

    1991-01-01

    The effects of operation mode and perforated-plate type on axial mixing of mixer-settler region in both dispersed and continuous phases were studied for a 5 cm I.D. pulsed perforated-plate extraction column of pulser-feeder type. The axial mixing coefficient was simultaneously measured to both phases by using the 'dynamic tracer co-injection method' proposed by the authors. The characteristics of both phases are observed obviously. Relatively to what it was in the continuous phase, the dispersed phase had short reaching time and long retardation time. The superficial axial mixing coefficient for dispersed phase becomes smaller than for the continuous phase. And experimental results showed that a backflow took place only in dispersed phase at a test section of 50 cm in axial length. The values of backflow ratio are observed from 0.5 to 1.8% of the dispersed net flow. (author)

  2. An analytical model for the prediction of the dynamic response of premixed flames stabilized on a heat-conducting perforated plate

    KAUST Repository

    Kedia, Kushal S.; Ghoniem, Ahmed F.

    2013-01-01

    The dynamic response of a premixed flame stabilized on a heat-conducting perforated plate depends critically on their coupled thermal interaction. The objective of this paper is to develop an analytical model to capture this coupling. The model

  3. An acoustic metamaterial composed of multi-layer membrane-coated perforated plates for low-frequency sound insulation

    Science.gov (United States)

    Fan, Li; Chen, Zhe; Zhang, Shu-yi; Ding, Jin; Li, Xiao-juan; Zhang, Hui

    2015-04-01

    Insulating against low-frequency sound (below 500 Hz ) remains challenging despite the progress that has been achieved in sound insulation and absorption. In this work, an acoustic metamaterial based on membrane-coated perforated plates is presented for achieving sound insulation in a low-frequency range, even covering the lower audio frequency limit, 20 Hz . Theoretical analysis and finite element simulations demonstrate that this metamaterial can effectively block acoustic waves over a wide low-frequency band regardless of incident angles. Two mechanisms, non-resonance and monopolar resonance, operate in the metamaterial, resulting in a more powerful sound insulation ability than that achieved using periodically arranged multi-layer solid plates.

  4. Boiling heat transfer in a flat slot between heating surface and perforated plate

    International Nuclear Information System (INIS)

    Kirichenko, Yu.A.; Rusanov, K.V.; Tyurina, E.G.

    1987-01-01

    The results are presented of the experimental study of heat transfer and crisis at nitrogen boiling in a flat gap between the horizontal heating surface and perforated plate. The gap width is 1.0 to 5.6 mm, diameter of holes is 1.0 to 2.0 mm, their spacing being 3.0 to 12.0 mm. The geometrical parameters dependence of the heat transfer coefficient and crisis characteristics is invesigated, the experimental data are compared with the results reported by other authors and calculations by some well-known formulas. 12 refs.; 3 figs.; 4 tabs

  5. Electrode design for soil decontamination with Radio-Frequency heating

    Energy Technology Data Exchange (ETDEWEB)

    Roland, U.; Holzer, F.; Kraus, M.; Trommler, U.; Kopinke, F.D. [Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Engineering, Leipzig (Germany)

    2011-10-15

    Radio-frequency heating to enhance soil decontamination requires adjusted solutions for the electrode design depending on scale and remediation technique. Parallel plate electrodes provide widely homogeneous field and temperature distributions and are, therefore, most suitable for supporting biodegradation processes. For thermally enhanced soil vapor extraction, certain temperature gradients can be accepted and, therefore, the less-demanding geometry of rod-shaped electrodes is usually applied. For electrode lengths of some meters, a design with an air gap has to be used in order to focus heating to the desired depth. Perforated rod electrodes may be simultaneously employed as extraction wells. Placing an oxidation catalyst in situ within the electrodes is an option for handling of highly loaded air flows. Coaxial antenna may be utilized to selectively heat soil compartments far from the surface of the soil. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Damping parameter study of a perforated plate with bias flow

    Science.gov (United States)

    Mazdeh, Alireza

    role of LES for research studies concerned with damping properties of liners is limited to validation of other empirical or theoretical approaches. This research has shown that LES can go beyond that and can be used for performing parametric studies to characterize the sensitivity of acoustic properties of multi--perforated liners to the changes in the geometry and flow conditions and be used as a tool to design acoustic liners. The conducted research provides an insightful understanding about the contribution of different flow and geometry parameters such as perforated plate thickness, aperture radius, porosity factors and bias flow velocity. While the study agrees with previous observations obtained by analytical or experimental methods, it also quantifies the impact from these parameters on the acoustic impedance of perforated plate, a key parameter to determine the acoustic performance of any system. The conducted study has also explored the limitations and capabilities of commercial tool when are applied for performing simulation studies on damping properties of liners. The overall agreement between LES results and previous studies proves that commercial tools can be effectively used for these applications under certain conditions.

  7. Calculating and optimizing inter-electrode capacitances of charge division microchannel plate detectors

    Energy Technology Data Exchange (ETDEWEB)

    Xing, Yan [Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Chen, Bo, E-mail: chenb@ciomp.ac.cn [Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); Zhang, Hong-Ji; Wang, Hai-Feng; He, Ling-Ping [Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); Jin, Fang-Yuan [Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); University of Chinese Academy of Sciences, Beijing 100049 (China)

    2016-04-01

    Based on the principle of charge division microchannel plate detectors, the inter-electrode capacitances of charge division anodes which are related to electronic noise of the charge sensitive amplifier and crosstalk effect of the anode are presented. Under all the requirements of charge division microchannel plate detectors such as the imaging linearity and spatial resolution, decreasing the inter-electrode capacitances is one way to improve the imaging performance. In this paper, we illustrate the simulation process of calculating the inter-electrode capacitances. Moreover, a Wedge and Strip (WSZ) anode is fabricated with the picosecond laser micromachining process. Comparing the simulated capacitances and measured capacitances, the three-dimensional finite element method is proved to be valid. Furthermore, by adjusting the design parameters of the anode, the effects of the substrate permittivity, insulation width and the size of pitch on the inter-electrode capacitances have been analysed. The structure of the charge division anode has been optimized based on the simulation data.

  8. The effect of electrode vertex angle on automatic tungsten-inert-gas welds for stainless steel 304L plates

    International Nuclear Information System (INIS)

    Maarek, V.; Sharir, Y.; Stern, A.

    1980-03-01

    The effect of electrode vertex angle on penetration depth and weld bead width, in automatic tungsten-inert-gas (TIG) dcsp bead-on-plate welding with different currents, has been studied for stainless steel 304L plates 1.5 mm and 8 mm thick. It has been found that for thin plates, wider and deeper welds are obtained when using sharper electrodes while, for thick plates, narrower and deeper welds are produced when blunt electrodes (vertex angle 180 deg) are used. An explanation of the results, based on a literature survey, is included

  9. Graphene-based supercapacitors in the parallel-plate electrode configuration: ionic liquids versus organic electrolytes.

    Science.gov (United States)

    Shim, Youngseon; Kim, Hyung J; Jung, Younjoon

    2012-01-01

    Supercapacitors with two single-sheet graphene electrodes in the parallel plate geometry are studied via molecular dynamics (MD) computer simulations. Pure 1-ethyl-3-methylimidazolium tetrafluoroborate (EMI+BF4-) and a 1.1 M solution of EMI+BF4- in acetonitrile are considered as prototypes of room-temperature ionic liquids (RTILs) and organic electrolytes. Electrolyte structure, charge density and associated electric potential are investigated by varying the charges and separation of the two electrodes. Multiple charge layers formed in the electrolytes in the vicinity of the electrodes are found to screen the electrode surface charge almost completely. As a result, the supercapacitors show nearly an ideal electric double layer behavior, i.e., the electric potential exhibits essentially a plateau behavior in the entire electrolyte region except for sharp changes in screening zones very close to the electrodes. Due to its small size and large charge separation, BF4- is considerably more efficient in shielding electrode charges than EMI+. In the case of the acetonitrile solution, acetonitrile also plays an important role by aligning its dipoles near the electrodes; however, the overall screening mainly arises from ions. Because of the disparity of shielding efficiency between cations and anions, the capacitance of the positively-charged anode is significantly larger than that of the negatively-charged cathode. Therefore, the total cell capacitance in the parallel plate configuration is primarily governed by the cathode. Ion conductivity obtained via the Green-Kubo (GK) method is found to be largely independent of the electrode surface charge. Interestingly, EMI+BF4- shows higher GK ion conductivity than the 1.1 M acetonitrile solution between two parallel plate electrodes.

  10. An analytical model for the prediction of the dynamic response of premixed flames stabilized on a heat-conducting perforated plate

    KAUST Repository

    Kedia, Kushal S.

    2013-01-01

    The dynamic response of a premixed flame stabilized on a heat-conducting perforated plate depends critically on their coupled thermal interaction. The objective of this paper is to develop an analytical model to capture this coupling. The model predicts the mean flame base standoff distance; the flame base area, curvature and speed; and the burner plate temperature given the operating conditions; the mean velocity, temperature and equivalence ratio of the reactants; thermal conductivity and the perforation ratio of the burner. This coupled model is combined with our flame transfer function (FTF) model to predict the dynamic response of the flame to velocity perturbations. We show that modeling the thermal coupling between the flame and the burner, while accounting for the two-dimensionality of the former, is critical to predicting the dynamic response characteristics such as the overshoot in the gain curve (resonant condition) and the phase delay. Good agreement with the numerical and experimental results is demonstrated over a range of conditions. © 2012 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

  11. Surface residual stress evaluation in double-electrode butt welded steel plates

    International Nuclear Information System (INIS)

    Estefen, S.F.; Gurova, T.; Castello, X.; Leontiev, A.

    2010-01-01

    Surface residual stress evaluation for double-electrode welding was studied. The stresses were monitored after each operational step: positioning, implementing of constraints, welding and constraints removal. The measurements were performed at the deposited metal, heat affected zone, base metal close to the weld joint and along the plate using the X-ray diffraction method. It was observed differences in the stress evaluations for double-electrode welding which resulted in lower bending distortions and higher values of surface residual stresses, compared with single-electrode welding. This behavior is associated with the stress distribution just after the welding processes in both heat affected zone and base metal close to the fillet for double-electrode welding. The main results from the laboratorial tests indicated lower values of the bending distortions for double-electrode welding compared with the single-electrode. In relation to the residual stress, the double-electrode welding generated, in general, higher stress values in both longitudinal and transversal directions.

  12. Device to position selectively a tool carried by a vehicle moving on the perforated plate of a tube bundle

    International Nuclear Information System (INIS)

    Bernardin, M.

    1985-01-01

    The aim of the invention is an examination device for a tube bundle of an apparatus such as, but not restrictively, a steam generator, situated in a dangerous zone, e.g. radioactive and designed to be introduced into the water box of the said and placed against the perforated plate of the tube bundle by an operator working outside of the said apparatus and able to operate whatever the vertical or horizontal position of the tube plate. The device has a selectively positionable tool - carrying vehicle comprising pistons positioning fingers extendable into the tubes and mounted on extendable supports perpendicular to the pistons and to each other, and an articulated telescopic arm fixed at one end to a rotary mounting on the vehicle and at the other end to an access opening in the vessel containing the tube plate, to hold the vehicle against the plate [fr

  13. An Investigation of Ionic Flows in a Sphere-Plate Electrode Gap

    International Nuclear Information System (INIS)

    Alisoy, H. Z.; Alagoz, B. B.; Alagoz, S.; Alisoy, G. T.

    2013-01-01

    This paper presents analyses of ion flow characteristics and ion discharge pulses in a sphere-ground plate electrode system. As a result of variation in electric field intensity in the electrode gap, the ion flows towards electrodes generate non-uniform discharging pulses. Inspection of these pulses provides useful information on ionic stream kinetics, the effective thickness of ion cover around electrodes, and the timing of ion clouds discharge pulse sequences. A finite difference time domain (FDTD) based space-charge motion simulation is used for the numerical analysis of the spatio-temporal development of ionic flows following the first Townsend avalanche, and the simulation results demonstrate expansion of the positive ion flow and compression of the negative ion flow, which results in non-uniform discharge pulse characteristics

  14. An Investigation of Ionic Flows in a Sphere-Plate Electrode Gap

    Science.gov (United States)

    Z. Alisoy, H.; Alagoz, S.; T. Alisoy, G.; B. Alagoz, B.

    2013-10-01

    This paper presents analyses of ion flow characteristics and ion discharge pulses in a sphere-ground plate electrode system. As a result of variation in electric field intensity in the electrode gap, the ion flows towards electrodes generate non-uniform discharging pulses. Inspection of these pulses provides useful information on ionic stream kinetics, the effective thickness of ion cover around electrodes, and the timing of ion clouds discharge pulse sequences. A finite difference time domain (FDTD) based space-charge motion simulation is used for the numerical analysis of the spatio-temporal development of ionic flows following the first Townsend avalanche, and the simulation results demonstrate expansion of the positive ion flow and compression of the negative ion flow, which results in non-uniform discharge pulse characteristics.

  15. Production of atmospheric pressure diffuse nanosecond pulsed dielectric barrier discharge using the array needles-plate electrode in air

    International Nuclear Information System (INIS)

    Yang Dezheng; Wang Wenchun; Jia Li; Nie Dongxia; Shi Hengchao

    2011-01-01

    In this paper, a bidirectional high pulse voltage with 20 ns rising time is employed to generate an atmospheric pressure diffuse dielectric barrier discharge using the array needles-plate electrode configuration. Both double needle and multiple needle electrode configurations nanosecond pulsed dielectric barrier discharges are investigated. It is found that a diffuse discharge plasma with low gas temperature can be obtained, and the plasma volume increases with the increase of the pulse peak voltage, but remains almost constant with the increase of the pulse repetition rate. In addition to showing the potential application on a topographically nonuniform surface treatment of the discharge, the multiple needle-plate electrode configuration with different needle-plate electrode gaps are also employed to generate diffuse discharge plasma.

  16. Ion-plasma gun for ion-milling machine

    Science.gov (United States)

    Kaminsky, Manfred S.; Campana, Jr., Thomas J.

    1976-01-01

    An ion gun includes an elongated electrode with a hollow end portion closed by a perforated end plate. The end plate is positioned parallel to a perforated flat electrode of opposite electrical polarity. An insulated sleeve encompasses the elongated electrode and extends outwardly from the perforated end towards the flat electrode. The sleeve length is separated into two portions of different materials. The first is formed of a high-temperature material that extends over the hollow portion of the elongated electrode where the arc is initiated by a point source electrode. The second sleeve portion extending over the remainder of the elongated electrode is of a resilient material for enhanced seal-forming ability and retention of plasma gas. Perforations are arranged in the flat electrode in a mutually opposing triangular pattern to project a plasma beam having a generally flat current profile towards a target requiring precision milling.

  17. Experimental investigation of sound absorption properties of perforated date palm fibers panel

    International Nuclear Information System (INIS)

    Elwaleed, A K; Nikabdullah, N; Nor, M J M; Tahir, M F M; Zulkifli, R

    2013-01-01

    This paper presents the sound absorption properties of a natural waste of date palm fiber perforated panel. A single layer of the date palm fibers was tested in this study for its sound absorption properties. The experimental measurements were carried out using impedance tube at the acoustic lab, Faculty of Engineering, Universiti Kebangsaan Malaysia. The experiment was conducted for the panel without air gap, with air gap and with perforated plate facing. Three air gap thicknesses of 10 mm, 20 mm and 30 mm were used between the date palm fiber sample and the rigid backing of the impedance tube. The results showed that when facing the palm date fiber sample with perforated plate the sound absorption coefficient improved at the higher and lower frequency ranges. This increase in sound absorption coincided with reduction in medium frequency absorption. However, this could be improved by using different densities or perforated plate with the date palm fiber panel.

  18. Sound absorption and transmission through flexible micro-perforated panels backed by an air layer and a thin plate.

    Science.gov (United States)

    Bravo, Teresa; Maury, Cédric; Pinhède, Cédric

    2012-05-01

    This paper describes theoretical and experimental investigations into the sound absorption and transmission properties of micro-perforated panels (MPP) backed by an air cavity and a thin plate. A fully coupled modal approach is proposed to calculate the absorption coefficient and the transmission loss of finite-sized micro-perforated panels-cavity-panel (MPPCP) partitions with conservative boundary conditions. It is validated against infinite partition models and experimental data. A practical methodology is proposed using collocated pressure-velocity sensors to evaluate in an anechoic environment the transmission and absorption properties of conventional MPPCPs. Results show under which conditions edge scattering effects should be accounted for at low frequencies. Coupled mode analysis is also performed and analytical approximations are derived from the resonance frequencies and mode shapes of a flexible MPPCP. It is found that the Helmholtz-type resonance frequency is deduced from the one associated to the rigidly backed MPPCP absorber shifted up by the mass-air mass resonance of the flexible non-perforated double-panel. Moreover, it is shown analytically and experimentally that the absorption mechanisms at the resonances are governed by a large air-frame relative velocity over the MPP surface, with either in-phase or out-of-phase relationships, depending on the MPPCP parameters.

  19. The effect of different rutile electrodes on mechanical properties of underwater wet welded AH-36 steel plates

    Science.gov (United States)

    Winarto, Winarto; Purnama, Dewin; Churniawan, Iwan

    2018-04-01

    Underwater welding is an important role in the rescue of ships and underwater structures, in case of emergency. In this study, the marine steel plates used are AH-36 steel as parent material. This type of steel is included in the High Strength Low Alloy (HSLA). Electrodes used for welding AH-36 steel plates are commonly the E6013 and E 7024 which are the type of based rutile electrodes. Those electrodes are widely available on the market and they would be compared with the original electrode for underwater which is the type of E7014 with the trade name of Broco UW-CS-1. Welding method used is Shielding Metal Arc Welding (SMAW) with the variation of 5 m and 10 m underwater depth and also varied with the electric current of 120A, 140A and 250A. It was found that hardness value of increased in the area of weld metal and HAZ. HAZ also tends to have the highest hardness compared to both of weld metal and base metal. Non destructive test by radiographed test (RT) on welds showed that there are found welding defects in the form of incomplete penetration on all variations of welding parameters, but there is no porosity defect detected. The results of the hardness tests of underwater wet welded steel plates show that the hardness value of both rutile electrodes (E6013 and E 7024) is apparently similar hardness value compared with the existing commercial electrode (E7014 of Broco UW-CS- 1). The tensile test results of underwater wet welded steel plates show that the use of rutile electrode of E6013 gives a better tensile properties than other rutile electrodes.

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

    Directory of Open Access Journals (Sweden)

    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.

  1. Elastic behavior and onset of cracking in cement composite plates reinforced by perforated thin steel sheets

    Science.gov (United States)

    Aronchik, V.

    1996-03-01

    Thin cement mortar plates reinforced by perforated thin steel sheets have been tested in four-point flexure loading. Six kinds of sheet reinforcement and to additional ones (for control) were used. Perforated sheets of the Daugavpils Factory of Machinery Chains differed by their thickness (0.6-1.8 mm), shape (round, rectangular, oval, "dumbbell"), and mark of steel (St. 08, 50, 70). Dimensions of plantes were 100×20×2 cm. Cements-sand mortar with a 1∶2 ratio of cement PZ35 and river sand of 3 mm grains was used as a matrix. Control specimens of similar dimensions and matrix were reinforced by wire cages and meshes (ferrocement). The testing was performed using an UMM-5 testing machine. Maximum deflection (at the midspan), tension, and shear strains were recorded. The expeimental data are presented in tables and graphs. The testing results showed that the elasticity modulus of material was in good agreement with the "admixture rule;" an onset of cracking for all types (excluding one) practically did not differ from reference samples; the mode of fracture in typical cases included an adhesion failure and significant shear strains. In one case the limit of the tension strength of the reinforcement was achieved.

  2. Transmission line theory for long plasma production by radio frequency discharges between parallel-plate electrodes

    International Nuclear Information System (INIS)

    Nonaka, S.

    1991-01-01

    In order to seek for a radio frequency (RF) eigen-mode of waves in producing a plasma between a pair of long dielectric-covered parallel-plate RF electrodes, this paper analyzed all normal modes propagating along the electrodes by solving Maxwell's equations. The result showed that only an odd surface wave mode will produce the plasma in usual experimental conditions, which will become a basic transmission line theory when use of such long electrodes for on-line mass-production of amorphous silicon solar cells

  3. Long-term stability of intracortical recordings using perforated and arrayed Parylene sheath electrodes

    Science.gov (United States)

    Hara, Seth A.; Kim, Brian J.; Kuo, Jonathan T. W.; Lee, Curtis D.; Meng, Ellis; Pikov, Victor

    2016-12-01

    Objective. Acquisition of reliable and robust neural recordings with intracortical neural probes is a persistent challenge in the field of neuroprosthetics. We developed a multielectrode array technology to address chronic intracortical recording reliability and present in vivo recording results. Approach. The 2 × 2 Parylene sheath electrode array (PSEA) was microfabricated and constructed from only Parylene C and platinum. The probe includes a novel three-dimensional sheath structure, perforations, and bioactive coatings that improve tissue integration and manage immune response. Coatings were applied using a sequential dip-coating method that provided coverage over the entire probe surface and interior of the sheath structure. A sharp probe tip taper facilitated insertion with minimal trauma. Fabricated probes were subject to examination by optical and electron microscopy and electrochemical testing prior to implantation. Main results. 1 × 2 arrays were successfully fabricated on wafer and then packaged together to produce 2 × 2 arrays. Then, probes having electrode sites with adequate electrochemical properties were selected. A subset of arrays was treated with bioactive coatings to encourage neuronal growth and suppress inflammation and another subset of arrays was implanted in conjunction with a virally mediated expression of Caveolin-1. Arrays were attached to a custom-made insertion shuttle to facilitate precise insertion into the rat motor cortex. Stable electrophysiological recordings were obtained during the period of implantation up to 12 months. Immunohistochemical evaluation of cortical tissue around individual probes indicated a strong correlation between the electrophysiological performance of the probes and histologically observable proximity of neurons and dendritic sprouting. Significance. The PSEA demonstrates the scalability of sheath electrode technology and provides higher electrode count and density to access a greater volume for recording

  4. Effect of plate shapes in orifice plate type flowmeters

    International Nuclear Information System (INIS)

    Moeller, S.V.

    1984-01-01

    The study of unusual plate shapes in orifice plate type flowmeters is presented, with a view to providing data for the substitution of the plate with one centered circular orifice in those applications where its use is not possible. For this purpose, six pairs of plates with different forms, with and without chamfered edges, were made and tested in a closed water loop. Results show that, generally, the use of chamfers improves the results and, in the case of perforated and slotlike orificed plates, the narrow-ness of the fluid passage tends to make unnecessary its use. (Author) [pt

  5. Multidisciplinary management of a mandibular buccal plate perforation

    Directory of Open Access Journals (Sweden)

    Yuli Nugraeni

    2010-12-01

    Full Text Available Background: Endodontists often have difficulty in the management of endo-perio cases, because they cannot visually detect the condition of outer root surfaces, especially in bucco-lateral roots. The bone defect is rare and its treatment needs collaboration of endodontists and periodontists. An endodontist treats cases based on dental history, radiograph of root canals to measure root canals, to uncover abnormalities and to diagnose, but as the endodontists cannot directly see the affected parts, the unseen portion of the tooth could only be seen after flap surgery. Purpose: This case presents the importance of multidisciplinary approach by the endodontist and periodontitis to treat bucal plate perforations in endo-perio cases. Case: The first patient, a 47-year-old female had endodontic treatment and a porcelain crown restoration; however, after several months she felt pain. The second patient, a 45 year-old female had endodontic treatment and after six months she feel painful. Case management: The first patient, was referred to a periodontist. The opening flap surgery has been done, a bone defect was found in tooth 45. Subsequently, the exposed crater was filled with a bone graft and the pain disappeared. The second patient, with improper endodontic treatment. The flap surgery was conducted, there was found a bone defect in tooth 36. The last treatment, a bone graft has been covered and then the pain was not present. Conclusion: Proper diagnosis and treatment of perforations on the buccal aspect of a root was able to eliminate pain and avoid tooth extraction.Latar belakang: Endodontis sering mengalami kesulitan dalam menangani kasus endo-perio karena secara visual kondisi ini tidak tampak diluar permukaan akar, khususnya pada akar bukolateral. Defek tulang sangatlah jarang dan perawatannya membutuhkan kolaborasi endodotis dan periodontis. Seorang endodontis merawat kasus-kasus berdasarkan riwayat gigi, radiografis saluran akar untuk melihat

  6. Stiffness Analysis of Nail-Plate Joints Subjected to Short-Term Loads

    DEFF Research Database (Denmark)

    Nielsen, Jacob

    nail-plates are designed for trusses. For many years, joints were made of boards with nails, but the increasing industrialism and the need for quick and usable assembly had the result that today nearly all trusses are pre-fabricated with nail-plates. The word "nail-plate" has been used for different...... types of plates. There are two main types of nail-plates: steel plates perforated with holes in which separate nails are used and steel plates perforated by a stamping machine, so the nails are made from the plate, see figur 1.2 on page 7. This type is sometimes called "punching metal plate...

  7. Catalytic Reactor For Oxidizing Mercury Vapor

    Science.gov (United States)

    Helfritch, Dennis J.

    1998-07-28

    A catalytic reactor (10) for oxidizing elemental mercury contained in flue gas is provided. The catalyst reactor (10) comprises within a flue gas conduit a perforated corona discharge plate (30a, b) having a plurality of through openings (33) and a plurality of projecting corona discharge electrodes (31); a perforated electrode plate (40a, b, c) having a plurality of through openings (43) axially aligned with the through openings (33) of the perforated corona discharge plate (30a, b) displaced from and opposing the tips of the corona discharge electrodes (31); and a catalyst member (60a, b, c, d) overlaying that face of the perforated electrode plate (40a, b, c) opposing the tips of the corona discharge electrodes (31). A uniformly distributed corona discharge plasma (1000) is intermittently generated between the plurality of corona discharge electrode tips (31) and the catalyst member (60a, b, c, d) when a stream of flue gas is passed through the conduit. During those periods when corona discharge (1000) is not being generated, the catalyst molecules of the catalyst member (60a, b, c, d) adsorb mercury vapor contained in the passing flue gas. During those periods when corona discharge (1000) is being generated, ions and active radicals contained in the generated corona discharge plasma (1000) desorb the mercury from the catalyst molecules of the catalyst member (60a, b, c, d), oxidizing the mercury in virtually simultaneous manner. The desorption process regenerates and activates the catalyst member molecules.

  8. Premixed Combustion of Coconut Oil on Perforated Burner

    Directory of Open Access Journals (Sweden)

    I.K.G. Wirawan

    2013-10-01

    Full Text Available Coconut oil premixed combustion behavior has been studied experimentally on perforated burner with equivalence ratio (φ varied from very lean until very rich. The results showed that burning of glycerol needs large number of air so that the laminar burning velocity (SL is the highest at very lean mixture and the flame is in the form of individual Bunsen flame on each of the perforated plate hole. As φ is increased the  SL decreases and the secondary Bunsen flame with open tip occurs from φ =0.54 at the downstream of perforated flame. The perforated flame disappears at φ = 0.66 while the secondary Bunsen flame still exist with SL increases following that of hexadecane flame trend and then extinct when the equivalence ratio reaches one or more. Surrounding ambient air intervention makes SL decreases, shifts lower flammability limit into richer mixture, and performs triple and cellular flames. The glycerol diffusion flame radiation burned fatty acids that perform cellular islands on perforated hole.  Without glycerol, laminar flame velocity becomes higher and more stable as perforated flame at higher φ. At rich mixture the Bunsen flame becomes unstable and performs petal cellular around the cone flame front. Keywords: cellular flame; glycerol; perforated flame;secondary Bunsen flame with open tip; triple flame

  9. Performance of Electrocoagulation Process for Removal of Sulphate Ion from Aqueous Environments Using Plate Aluminum Electrodes

    Directory of Open Access Journals (Sweden)

    a.h Mahvi

    2012-05-01

    Full Text Available

    Background and Objectives: Sulphate ion is one of the main ions available in natural and waste water. The high rate of sulphate in drinking water causes health problems such as irritation and digestive problems and makes water taste bitter. The purpose of this study was to assess the efficiency of sulphate ion removal from drinking water through Electrocogualation process (EC using plate aluminum electrodes. Methods: This study was conducted as a pilot plant using one glass tank in the volume of 1.3liter containing 6 plate aluminum electrodes. These electrodes were attached to a power supply in a mono-polar and parallel arrangement in order to switch the alternating current to the direct one. That is, each electrode was attached to positive and negative poles directly and alternately. The tank was filled with synthetic water containing sulphate ion with the concentration of 350 & 700mg/L. Percentage of sulphate ion removal in potential range of 10, 20 and 30 V, reaction times of 40, 20 and 60min and pH 7.0, 3.0 & 11.0 were measured. Results: In this study the maximum efficiency of sulphate ion removal was in the electrical potential of 30 V, reaction time of 60min and pH 11.0. With increase of ion concentration, the time needed to achieve a suitable efficiency of removal increased, that is, it indicated the direct effect of pH and difference of electrical potential on removal of sulphate ion through EC process. Conclusion: The results of this research show that Electrocogualation technology can be introduced as a suitable and promising technique to remove sulphate ion from aqueous environments using plate aluminum electrodes.

     

  10. Performance of Electrocoagulation Process for Removal of Sulphate Ion from Aqueous Environments Using Plate Aluminum Electrodes

    Directory of Open Access Journals (Sweden)

    Rajabizadeh A.

    2010-09-01

    Full Text Available Background and Objectives: Sulphate ion is one of the main ions available in natural and waste water. The high rate of sulphate in drinking water causes health problems such as irritation and digestive problems and makes water taste bitter. The purpose of this study was to assess the efficiency of sulphate ion removal from drinking water through Electrocogualation process (EC using plate aluminum electrodes.Methods: This study was conducted as a pilot plant using one glass tank in the volume of 1.3liter containing 6 plate aluminum electrodes. These electrodes were attached to a power supply in a mono-polar and parallel arrangement in order to switch the alternating current to the direct one. That is, each electrode was attached to positive and negative poles directly and alternately. The tank was filled with synthetic water containing sulphate ion with the concentration of 350 & 700mg/L. Percentage of sulphate ion removal in potential range of 10, 20 and 30 V, reaction times of 40, 20 and 60min and pH 7.0, 3.0 & 11.0 were measured.Results: In this study the maximum efficiency of sulphate ion removal was in the electrical potential of 30 V, reaction time of 60min and pH 11.0. With increase of ion concentration, the time needed to achieve a suitable efficiency of removal increased, that is, it indicated the direct effect of pH and difference of electrical potential on removal of sulphate ion through EC process.Conclusion: The results of this research show that Electrocogualation technology can be introduced as a suitable and promising technique to remove sulphate ion from aqueous environments using plate aluminum electrodes.

  11. Study on modal characteristics of perforated shell using effective Young's modulus

    International Nuclear Information System (INIS)

    Jhung, Myung Jo; Yu, Seon Oh

    2011-01-01

    Research highlights: → The effective Young's modulus of perforated shell is proposed for modal analysis. → The penetration pattern is almost negligible for effective elastic constants. → The frequency of perforated shell decreases significantly due to the hole effect. - Abstract: For the perforated cylindrical shell submerged in fluid, it is almost impossible to develop a finite element model due to the necessity of the fine meshing of the shell and the fluid at the same time. This necessitates the use of solid shell with effective material properties. Unfortunately the effective elastic constants are not found in any references even though the ASME code is suggesting those for perforated plate. Therefore in this study the effective material properties of perforated shell are suggested by performing several finite element analyses with respect to the ligament efficiencies.

  12. Yield surfaces for perforated plates with square arrays of holes

    International Nuclear Information System (INIS)

    Bhattacharya, A.; Venkat Raj, V.

    2004-01-01

    A symmetric model of a perforated plate containing a 3x3 array of circular holes, arranged in a square pattern, was chosen and elastoplastic finite element analyses were carried out to determine the limit stresses for both pitch and diagonal directions of loading, for different values of biaxiality ratios. Plane stress conditions were assumed and the Tresca and von Mises yield criteria were employed to obtain two different sets of results. Yield surfaces were constructed and 'general cut-out factors' were determined for four different ligament efficiencies. The FEM results obtained by the authors using the Tresca and von Mises yield criteria were compared with the corresponding results of [J. Pressure Vessel Technol. Trans. ASME (1975) 146-154] and [J. Pressure Vessel Technol. Trans. ASME (1997) 122-126], respectively. The results based on the Tresca yield criterion obtained by the present authors and those in [J. Pressure Vessel Technol. Trans. ASME (1975) 146-154] were found to agree well with each other. In the case of the von Mises yield criterion, the agreement with [J. Pressure Vessel Technol. Trans. ASME 122-126] is generally good. The estimates based on the Tresca yield criterion are seen to result in lower values of limit stresses and cut-out factors as compared to those based on the von Mises yield criterion. The difference is attributed to the yield criterion and the flow rule chosen for the analysis. The shape as well as the size of the yield surface was found to depend on the ligament efficiency

  13. Device for filling tubular electrode plates for lead batteries. [German patent

    Energy Technology Data Exchange (ETDEWEB)

    Barth, P.U.; Kubis, C.; Weber, H.J.; Wiepen, R.

    1979-02-01

    The device applies the vibration principle and according to the invention it uses a filling cassette for accommodating tubular electrode plates. The filling cassette has a filling funnel and is suspended with its vibration drive by springs. The vibration drive consists either of two out-of-balance motors, which are rigidly connected to the lower frame of the cassette, and have opposite directions of rotation, or of one out-of-balance motor, which is connected to a joint below the frame of the cassette.

  14. Time varying stress in ligaments of perforated plates with reference to prestressed concrete reactor vessels

    International Nuclear Information System (INIS)

    Stefanou, G.D.

    1978-01-01

    The work described herein relates to the prediction of stresses in materials which exhibit time varying strains with particular reference to the ligaments of perforated circular concrete slabs, subjected to long-term radial prestress and uniform elevated temperature. The perforations are reinforced with steel liners and arranged in a square central lattice symmetrical about two orthogonal axes. Special reference is made to the distribution of stress in the standpipe region of prestressed concrete cylindrical pressure or containment vessels for gas cooled reactors. In order to assess the stress distribution around the perforated zone of a circular slab, a method of analysis was developed by the author, based on the ''Equivalent Elastic Modulus'' of the perforated zone and the ''Effective Modulus Method'', utilizing experimental data obtained from tests performed on model specimens. The object of this paper is to extend the above method of analysis into the perforated region, and assess the long-term stresses in the ligaments. The proposed method is accomplished by an application of the Finite Element Method for the elastic plane stress case. Comparisons of experimental results and theoretical predictions by the proposed method, and other analytical methods are made for a series of perforated concrete slabs subjected to radial in-plane loading: 10,342 kN/m 2 (1,5000 psi), and uniform elevated temperature of 80 0 C. The investigation, though in general terms, could be applied to the perforated region of cylindrical pressure vessels for nuclear reactors. Finally the paper describes briefly in Appendix 3 a direct solution procedure for calculating time dependent stresses in concrete structures based on the principles of variational calculus. Analytical predictions obtained by the proposed method which is a step-by-step analysis, are compared with the variational principle method. (author)

  15. Electromagnetic response of extraordinary transmission plates inspired on Babinet’s principle

    OpenAIRE

    Navarro Cía, Miguel; Beruete Díaz, Miguel; Sorolla Ayza, Mario

    2011-01-01

    This chapter is devoted to polarization effects arisen from perforated metallic plates exhibiting extraordinary transmission (ET). Setting aside the state-of-the-art of perforated metallic plates, we show that by applying Babinet’s principle, subwavelength hole arrays (SHAs) arranged in rectangular lattice can further enhance its potential polarization response. Different perspectives are brought about to describe and understand the particular behaviour of self-complementarines...

  16. Study on modal characteristics of perforated shell using effective Young's modulus

    Energy Technology Data Exchange (ETDEWEB)

    Jhung, Myung Jo, E-mail: mjj@kins.re.kr [Korea Institute of Nuclear Safety, 19 Guseong-dong, Yuseong-gu, Daejeon 305-338 (Korea, Republic of); Yu, Seon Oh [Korea Institute of Nuclear Safety, 19 Guseong-dong, Yuseong-gu, Daejeon 305-338 (Korea, Republic of)

    2011-06-15

    Research highlights: > The effective Young's modulus of perforated shell is proposed for modal analysis. > The penetration pattern is almost negligible for effective elastic constants. > The frequency of perforated shell decreases significantly due to the hole effect. - Abstract: For the perforated cylindrical shell submerged in fluid, it is almost impossible to develop a finite element model due to the necessity of the fine meshing of the shell and the fluid at the same time. This necessitates the use of solid shell with effective material properties. Unfortunately the effective elastic constants are not found in any references even though the ASME code is suggesting those for perforated plate. Therefore in this study the effective material properties of perforated shell are suggested by performing several finite element analyses with respect to the ligament efficiencies.

  17. Optimization of the process of steel strip perforation and nickel platting for the purpose of elimination of trichloroethylene from the cleaning process of perforated steel strip

    Directory of Open Access Journals (Sweden)

    Petrović Aleksandra B.

    2009-01-01

    Full Text Available In the production of pocket type electrodes for Ni-Cd batteries perforation of proper steel strips and then nickel platting of perforated steel strips were made. In the nickel platting process, the organic solvent, trichloroethylene, has previously been used for cleaning. Due to the carcinogenic nature of trichloroethylene and the many operations previously required during cleaning, it was considered to do cleaning of perforated steel strips without use of the mentioned organic solvent. In the purpose of elimination of trichloroethylene from the cleaning process of perforated steel strips, the tests of perforation of steel strips with use of oils of different viscosity were made. It was shown that there was no dysfunction during the work of the perforation plants, meaning there was no additional heating of the strips, deterring of the steel filings, nor excessive wearing of the perforation apparatus. The perforation percent was the same irrelevant of the viscosity of the used oil. Before being perforated using the oils with different viscosity, the nickel platting steel strips were cleaned in different degreasers (based on NaOH as well as on KOH. It was shown that efficient cleaning without the use of trichloroethylene is possible with the use of oil with smaller viscosity in the perforated steel strips process and the degreaser based on KOH in the cleaning process, before nickel platting. It also appeared that the alkali degreaser based on KOH was more efficient, bath corrections were made less often and the working period of the baths was longer, which all in summary means less quantity of chemicals needed for degreasing of perforated steel strips.

  18. Flexible electrode belt for EIT using nanofiber web dry electrodes.

    Science.gov (United States)

    Oh, Tong In; Kim, Tae Eui; Yoon, Sun; Kim, Kap Jin; Woo, Eung Je; Sadleir, Rosalind J

    2012-10-01

    Efficient connection of multiple electrodes to the body for impedance measurement and voltage monitoring applications is of critical importance to measurement quality and practicality. Electrical impedance tomography (EIT) experiments have generally required a cumbersome procedure to attach the multiple electrodes needed in EIT. Once placed, these electrodes must then maintain good contact with the skin during measurements that may last several hours. There is usually also the need to manage the wires that run between the electrodes and the EIT system. These problems become more severe as the number of electrodes increases, and may limit the practicality and portability of this imaging method. There have been several trials describing human-electrode interfaces using configurations such as electrode belts, helmets or rings. In this paper, we describe an electrode belt we developed for long-term EIT monitoring of human lung ventilation. The belt included 16 embossed electrodes that were designed to make good contact with the skin. The electrodes were fabricated using an Ag-plated PVDF nanofiber web and metallic threads. A large contact area and padding were used behind each electrode to improve subject comfort and reduce contact impedances. The electrodes were incorporated, equally spaced, into an elasticated fabric belt. We tested the electrode belt in conjunction with the KHU Mark1 multi-frequency EIT system, and demonstrate time-difference images of phantoms and human subjects during normal breathing and running. We found that the Ag-plated PVDF nanofiber web electrodes were suitable for long-term measurement because of their flexibility and durability. Moreover, the contact impedance and stability of the Ag-plated PVDF nanofiber web electrodes were found to be comparable to similarly tested Ag/AgCl electrodes.

  19. Stresses and strains in thick perforated orthotropic plates

    Science.gov (United States)

    A. Alshaya; John Hunt; R. Rowlands

    2016-01-01

    Stress and strain concentrations and in-plane and out-of-plane stress constraint factors associated with a circular hole in thick, loaded orthotropic composite plates are determined by three-dimensional finite element method. The plate has essentially infinite in-plane geometry but finite thickness. Results for Sitka Spruce wood are emphasized, although some for carbon...

  20. Typhoid Intestinal Perforation: 24 Perforations in One Patient

    African Journals Online (AJOL)

    Intestinal perforation is a common cause of peritonitis necessitating emergency surgical intervention. Perforation ... Mortality rates of typhoid intestinal perforation (TIP) cases are ... may be obscured clinical features with resultant delays in.

  1. Electrochemical Oxidation of Glycerol Using Gold Electrode

    International Nuclear Information System (INIS)

    Mohamed Rozali Othman; Amirah Ahmad

    2015-01-01

    Cyclic voltammetry, potential linear V and chronocuolometry methods were carried out to gain electrochemical behavior of glycerol at a gold electrode. Potassium hydroxide and sulfuric acid were chosen to be the electrolyte for the electro-oxidation of this organic compound. Besides gold plate electrode, gold composite electrode (Au-PVC) was also used as the working electrode. The Au-PVC composite electrode was characterized by Scanning Electron Microscopy (SEM) to determine its morphological aspects before and after used in electrochemical oxidation of glycerol. In alkaline solution, the adsorption of hydroxide species onto the surface of both gold plate and composite Au-PVC electrodes occurs at potential around 500 mV vs SCE. However, at gold plate electrode, there was a small, broad peak before the drastic escalation of current densities which indicates the charge transfer of the chemisorbed OH - anion. In acidic media, the gold oxide was formed after potential 1.0 V. From the cyclic voltammogram glycerol undergo oxidation twice in potassium hydroxide at gold plate and Au-PVC composite electrodes, while in sulfuric acid, oxidation reaction happened once for glycerol on the gold plate electrode. Overall, electrochemical oxidation of glycerol was more effective in alkaline media. Tafel graph which plotted from potential linear V method shows that Au-PVC composite electrode is better than gold plate electrode for the electro-oxidation of glycerol in alkaline solution. Electrochemical oxidation of glycerol products as analyzed by Gas Chromatography-Mass Spectrometry (GC-MS) produced several carboxylic acids and phenolic compounds. (author)

  2. Comparison between wire mesh and plate electrodes during Wide-pattern machining on invar fine sheet using through-mask electrochemical micromachining

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Kwang-ho; Jin, Da-som; Kim, Seong-hyun; Lee, Eun-sang [Inha University, Incheon (Korea, Republic of)

    2017-04-15

    Many research on the fabrication of Organic light emitting diodes (OLED) shadow masks with high resolution have been carried out because of the development of the smart-display industry. It is the parts of display panel which has millions of micro holes on invar (Fe- Ni) fine sheet. Various techniques such as laser machining, chemical etching and Electrochemical micro-machining (EMM) are used to produce micro-hole arrays. In this study, Through-mask electrochemical machining (TMEMM) combine with portion of photolithography process was applied to fabricate micro-hole arrays on invar fine sheet. The sheet was coated with dry film photoresist. Two types of electrode, plate and mesh, was used to compare the influence of electrode type. The sheet was coated with dry film photoresist with micro- sized through holes. The results were compared in regard to uniformity and taper angle. Compared with the plate electrode, the mesh electrode has better uniformity and taper angle which is important criteria of OLED shadow mask. These results could be used to improve TMEMM for invar fine sheet when it is applied to fabricate micro-hole arrays and help to obtain optical uniformity and desired taper angles.

  3. Rare occupational cause of nasal septum perforation: Nickel exposure

    Directory of Open Access Journals (Sweden)

    Ertugrul Cagri Bolek

    2017-10-01

    Full Text Available Many etiologies are held accountable for nasal septum perforations. Topical nasal drug usage, previous surgeries, trauma, nose picking, squamous cell carcinoma, some rheumatological disorders such as granulomatosis with polyangiitis (Wegener granulomatosis, some infectious diseases such as syphilis and leprosy are among the causes of the perforations. Occupational heavy metal exposures by inhalation rarely may also cause nasal septum perforation. Here, we present a 29-year-old patient without any known diseases, who is a worker at a metallic coating and nickel-plating factory, referred for investigation of his nasal cartilage septum perforation from an otorhinolaryngology clinic. The patient questioning, physical examination and laboratory assessment about rheumatic and infectious diseases were negative. There was a metallic smell in the breath during the physical examination. The analysis showed serum nickel level at 31 μg/l and urine nickel at 18 μg/l (84.11 μg/g creatinine. Other possible serum and urine heavy metal levels were within normal ranges. Nickel exposure is usually together with other heavy metals (chromium or cadmium, it is rarely alone. Nickel ingested by inhalation usually leads to respiratory problems such as reduced olfactory acuity, ulcers, septum perforation or tumors of the nasal sinuses. This case demonstrates the importance of occupational anamnesis and awareness of diagnosis. Int J Occup Med Environ Health 2017;30(6:963–967

  4. Hydrodynamic loading and viscous damping of patterned perforations on microfabricated resonant structures

    DEFF Research Database (Denmark)

    Park, Kidong; Shim, Jeong; Solovyeva, Vita

    2012-01-01

    We examined the hydrodynamic loading of vertically resonating microfabricated plates immersed in liquids with different viscosities. The planar structures were patterned with focused ion beam, perforating various shapes with identical area but varying perimeters. The hydrodynamic loading of various...

  5. Mechanisms of stabilization and blowoff of a premixed flame downstream of a heat-conducting perforated plate

    KAUST Repository

    Kedia, Kushal S.

    2012-03-01

    The objective of this work is to investigate the flame stabilization mechanism and the conditions leading to the blowoff of a laminar premixed flame anchored downstream of a heat-conducting perforated-plate/multi-hole burner, with overall nearly adiabatic conditions. We use unsteady, fully resolved, two-dimensional simulations with detailed chemical kinetics and species transport for methane-air combustion. Results show a bell-shaped flame stabilizing above the burner plate hole, with a U-shaped section anchored between neighboring holes. The base of the positively curved U-shaped section of the flame is positioned near the stagnation point, at a location where the flame displacement speed is equal to the flow speed. This location is determined by the combined effect of heat loss and flame stretch on the flame displacement speed. As the mass flow rate of the reactants is increased, the flame displacement speed at this location varies non-monotonically. As the inlet velocity is increased, the recirculation zone grows slowly, the flame moves downstream, and the heat loss to the burner decreases, strengthening the flame and increasing its displacement speed. As the inlet velocity is raised, the stagnation point moves downstream, and the flame length grows to accommodate the reactants mass flow. Concomitantly, the radius of curvature of the flame base decreases until it reaches an almost constant value, comparable to the flame thickness. While the heat loss decreases, the higher flame curvature dominates thereby reducing the displacement speed of the flame base. For a stable flame, the gradient of the flame base displacement speed normal to the flame is higher than the gradient of the flow speed along the same direction, leading to dynamic stability. As inlet velocity is raised further, the former decreases while the latter increases until the stability condition is violated, leading to blowoff. The flame speed during blow off is determined by the feedback between the

  6. The Effect of Honeycomb Cavity: Acoustic Performance of a Double-leaf Micro Perforated Panel

    OpenAIRE

    Huang, Yuxian; Li, Kai Ming

    2016-01-01

    A micro perforated panel (MPP) is a device consisting of a thin plate and submillimeter perforations for reducing low frequency noise. MPPs have many advantages compared to traditional sound absorption materials, such as durability and designability, and they can be used in a variety of places such as room interior designs, passenger and crew compartments of aircrafts and combustion engines. The models in this study were designed and fabricated with the latest 3-D printing technology. The tra...

  7. Pedicled perforator flaps

    DEFF Research Database (Denmark)

    Demirtas, Yener; Ozturk, Nuray; Kelahmetoglu, Osman

    2009-01-01

    Described in this study is a surgical concept that supports the "consider and use a pedicled perforator flap whenever possible and indicated" approach to reconstruct a particular skin defect. The operation is entirely free-style; the only principle is to obtain a pedicled perforator flap...... to reconstruct the defect. The perforators are marked with a hand-held Doppler probe and multiple flaps are designed. The appropriate flap is elevated after identifying the perforator(s). Dissection of the perforator(s) or complete incision of the flap margins are not mandatory if the flap is mobilized...... adequately to cover the defect. Defects measuring 3 x 3 cm up to 20 x 20 cm at diverse locations were successfully reconstructed in 20 of 21 patients with 26 flaps. Pedicled perforator flaps offer us reliable and satisfactory results of reconstruction at different anatomic territories of the body. It sounds...

  8. Rare occupational cause of nasal septum perforation: Nickel exposure.

    Science.gov (United States)

    Bolek, Ertugrul Cagri; Erden, Abdulsamet; Kulekci, Cagri; Kalyoncu, Umut; Karadag, Omer

    2017-10-06

    Many etiologies are held accountable for nasal septum perforations. Topical nasal drug usage, previous surgeries, trauma, nose picking, squamous cell carcinoma, some rheumatological disorders such as granulomatosis with polyangiitis (Wegener granulomatosis), some infectious diseases such as syphilis and leprosy are among the causes of the perforations. Occupational heavy metal exposures by inhalation rarely may also cause nasal septum perforation. Here, we present a 29-year-old patient without any known diseases, who is a worker at a metallic coating and nickel-plating factory, referred for investigation of his nasal cartilage septum perforation from an otorhinolaryngology clinic. The patient questioning, physical examination and laboratory assessment about rheumatic and infectious diseases were negative. There was a metallic smell in the breath during the physical examination. The analysis showed serum nickel level at 31 μg/l and urine nickel at 18 μg/l (84.11 μg/g creatinine). Other possible serum and urine heavy metal levels were within normal ranges. Nickel exposure is usually together with other heavy metals (chromium or cadmium), it is rarely alone. Nickel ingested by inhalation usually leads to respiratory problems such as reduced olfactory acuity, ulcers, septum perforation or tumors of the nasal sinuses. This case demonstrates the importance of occupational anamnesis and awareness of diagnosis. Int J Occup Med Environ Health 2017;30(6):963-967. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  9. Fringe Capacitance of a Parallel-Plate Capacitor.

    Science.gov (United States)

    Hale, D. P.

    1978-01-01

    Describes an experiment designed to measure the forces between charged parallel plates, and determines the relationship among the effective electrode area, the measured capacitance values, and the electrode spacing of a parallel plate capacitor. (GA)

  10. Electric field and dielectrophoretic force on a dielectric particle chain in a parallel-plate electrode system

    International Nuclear Information System (INIS)

    Techaumnat, B; Eua-arporn, B; Takuma, T

    2004-01-01

    This paper presents results of calculations of the electric field and dielectrophoretic force on a dielectric particle chain suspended in a host liquid lying between parallel-plate electrodes. The method of calculation is based on the method of multipole images using the multipole re-expansion technique. We have investigated the effect of the particle permittivity, the tilt angle (between the chain and the applied field) and the chain arrangement on the electric field and force. The results show that the electric field intensification rises in accordance with the increase in the ratio of the particle-to-liquid permittivity, Γ ε . The electric field at the contact point between the particles decreases with increasing tilt angle, while the maximal field at the contact point between the particles and the plate electrodes is almost unchanged. The maximal field can be approximated by a simple formula, which is a quadratic function of Γ ε . The dielectrophoretic force depends significantly on the distance from other particles or an electrode. However, for the tilt angles in this paper, the horizontal force on the upper particle of the chain always has the direction opposite to the shear direction. The maximal horizontal force of a chain varies proportional to (Γ ε - 1) 1.7 if the particles in the chain are still in contact with each other. The approximated force, based on the force on an isolated chain, has been compared with our calculation results. The comparison shows that no approximation model agrees well with our results throughout the range of permittivity ratios

  11. Differentiating perforated from non-perforated appendicitis on contrast-enhanced magnetic resonance imaging

    International Nuclear Information System (INIS)

    Rosenbaum, Daniel G.; Kovanlikaya, Arzu; Askin, Gulce; Beneck, Debra M.

    2017-01-01

    The role of magnetic resonance imaging (MRI) in pediatric appendicitis is increasing; MRI findings predictive of appendiceal perforation have not been specifically evaluated. To assess the performance of MRI in differentiating perforated from non-perforated appendicitis. A retrospective review of pediatric patients undergoing contrast-enhanced MRI and subsequent appendectomy was performed, with surgicopathological confirmation of perforation. Appendiceal diameter and the following 10 MRI findings were assessed: appendiceal restricted diffusion, wall defect, appendicolith, periappendiceal free fluid, remote free fluid, restricted diffusion within free fluid, abscess, peritoneal enhancement, ileocecal wall thickening and ileus. Two-sample t-test and chi-square tests were used to analyze continuous and discrete data, respectively. Sensitivity and specificity for individual MRI findings were calculated and optimal thresholds for measures of accuracy were selected. Seventy-seven patients (mean age: 12.2 years) with appendicitis were included, of whom 22 had perforation. The perforated group had a larger mean appendiceal diameter and mean number of MRI findings than the non-perforated group (12.3 mm vs. 8.6 mm; 5.0 vs. 2.0, respectively). Abscess, wall defect and restricted diffusion within free fluid had the greatest specificity for perforation (1.00, 1.00 and 0.96, respectively) but low sensitivity (0.36, 0.25 and 0.32, respectively). The receiver operator characteristic curve for total number of MRI findings had an area under the curve of 0.92, with an optimal threshold of 3.5. A threshold of any 4 findings had the best ability to accurately discriminate between perforated and non-perforated cases, with a sensitivity of 82% and specificity of 85%. Contrast-enhanced MRI can differentiate perforated from non-perforated appendicitis. The presence of multiple findings increases diagnostic accuracy, with a threshold of any four findings optimally discriminating between

  12. Differentiating perforated from non-perforated appendicitis on contrast-enhanced magnetic resonance imaging.

    Science.gov (United States)

    Rosenbaum, Daniel G; Askin, Gulce; Beneck, Debra M; Kovanlikaya, Arzu

    2017-10-01

    The role of magnetic resonance imaging (MRI) in pediatric appendicitis is increasing; MRI findings predictive of appendiceal perforation have not been specifically evaluated. To assess the performance of MRI in differentiating perforated from non-perforated appendicitis. A retrospective review of pediatric patients undergoing contrast-enhanced MRI and subsequent appendectomy was performed, with surgicopathological confirmation of perforation. Appendiceal diameter and the following 10 MRI findings were assessed: appendiceal restricted diffusion, wall defect, appendicolith, periappendiceal free fluid, remote free fluid, restricted diffusion within free fluid, abscess, peritoneal enhancement, ileocecal wall thickening and ileus. Two-sample t-test and chi-square tests were used to analyze continuous and discrete data, respectively. Sensitivity and specificity for individual MRI findings were calculated and optimal thresholds for measures of accuracy were selected. Seventy-seven patients (mean age: 12.2 years) with appendicitis were included, of whom 22 had perforation. The perforated group had a larger mean appendiceal diameter and mean number of MRI findings than the non-perforated group (12.3 mm vs. 8.6 mm; 5.0 vs. 2.0, respectively). Abscess, wall defect and restricted diffusion within free fluid had the greatest specificity for perforation (1.00, 1.00 and 0.96, respectively) but low sensitivity (0.36, 0.25 and 0.32, respectively). The receiver operator characteristic curve for total number of MRI findings had an area under the curve of 0.92, with an optimal threshold of 3.5. A threshold of any 4 findings had the best ability to accurately discriminate between perforated and non-perforated cases, with a sensitivity of 82% and specificity of 85%. Contrast-enhanced MRI can differentiate perforated from non-perforated appendicitis. The presence of multiple findings increases diagnostic accuracy, with a threshold of any four findings optimally discriminating between

  13. Differentiating perforated from non-perforated appendicitis on contrast-enhanced magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Rosenbaum, Daniel G.; Kovanlikaya, Arzu [New York-Presbyterian Hospital/Weill Cornell Medicine, Division of Pediatric Radiology, New York, NY (United States); Askin, Gulce [Weill Cornell Medical College, Division of Biostatistics and Epidemiology, New York, NY (United States); Beneck, Debra M. [New York-Presbyterian Hospital/Weill Cornell Medicine, Department of Pathology, New York, NY (United States)

    2017-10-15

    The role of magnetic resonance imaging (MRI) in pediatric appendicitis is increasing; MRI findings predictive of appendiceal perforation have not been specifically evaluated. To assess the performance of MRI in differentiating perforated from non-perforated appendicitis. A retrospective review of pediatric patients undergoing contrast-enhanced MRI and subsequent appendectomy was performed, with surgicopathological confirmation of perforation. Appendiceal diameter and the following 10 MRI findings were assessed: appendiceal restricted diffusion, wall defect, appendicolith, periappendiceal free fluid, remote free fluid, restricted diffusion within free fluid, abscess, peritoneal enhancement, ileocecal wall thickening and ileus. Two-sample t-test and chi-square tests were used to analyze continuous and discrete data, respectively. Sensitivity and specificity for individual MRI findings were calculated and optimal thresholds for measures of accuracy were selected. Seventy-seven patients (mean age: 12.2 years) with appendicitis were included, of whom 22 had perforation. The perforated group had a larger mean appendiceal diameter and mean number of MRI findings than the non-perforated group (12.3 mm vs. 8.6 mm; 5.0 vs. 2.0, respectively). Abscess, wall defect and restricted diffusion within free fluid had the greatest specificity for perforation (1.00, 1.00 and 0.96, respectively) but low sensitivity (0.36, 0.25 and 0.32, respectively). The receiver operator characteristic curve for total number of MRI findings had an area under the curve of 0.92, with an optimal threshold of 3.5. A threshold of any 4 findings had the best ability to accurately discriminate between perforated and non-perforated cases, with a sensitivity of 82% and specificity of 85%. Contrast-enhanced MRI can differentiate perforated from non-perforated appendicitis. The presence of multiple findings increases diagnostic accuracy, with a threshold of any four findings optimally discriminating between

  14. Fuel cell plates with skewed process channels for uniform distribution of stack compression load

    Science.gov (United States)

    Granata, Jr., Samuel J.; Woodle, Boyd M.

    1989-01-01

    An electrochemical fuel cell includes an anode electrode, a cathode electrode, an electrolyte matrix sandwiched between electrodes, and a pair of plates above and below the electrodes. The plate above the electrodes has a lower surface with a first group of process gas flow channels formed thereon and the plate below the electrodes has an upper surface with a second group of process gas flow channels formed thereon. The channels of each group extend generally parallel to one another. The improvement comprises the process gas flow channels on the lower surface of the plate above the anode electrode and the process gas flow channels on the upper surface of the plate below the cathode electrode being skewed in opposite directions such that contact areas of the surfaces of the plates through the electrodes are formed in crisscross arrangements. Also, the plates have at least one groove in areas of the surfaces thereof where the channels are absent for holding process gas and increasing electrochemical activity of the fuel cell. The groove in each plate surface intersects with the process channels therein. Also, the opposite surfaces of a bipolar plate for a fuel cell contain first and second arrangements of process gas flow channels in the respective surfaces which are skewed the same amount in opposite directions relative to the longitudinal centerline of the plate.

  15. Role of material properties and mechanical constraint on stress-assisted diffusion in plate electrodes of lithium ion batteries

    International Nuclear Information System (INIS)

    Song Yicheng; Zhang Junqian; Shao Xianjun; Guo Zhansheng

    2013-01-01

    This work investigates the stress-assisted diffusion of lithium ions in layered electrodes of Li-ion batteries. Decoupled diffusion governing equations are obtained. Material properties, which are characterized by a single dimensionless parameter, and mechanical constraint between a current collector and an active layer, which is characterized by the elastic modulus ratio and thickness ratio between the layers, are identified as key factors that govern the stress-assisted diffusion. For a symmetric plate electrode, stress is induced by the Li-ion concentration gradient, and stress-assisted diffusion therefore depends only on the material properties. For an asymmetric bilayer electrode, mechanical constraint plays a very important role in the diffusion via generation of bending stress. Diffusion may be facilitated, or inversely impeded, according to the constraint. By summarizing the coupling factors of common active materials and investigating the concentration variation induced by stress-assisted diffusion in various electrodes, this work provides insights on stress-assisted diffusion in a layered electrode, as well as suggestions for relevant modelling works on whether the stress-assisted diffusion should be taken into account according to the selection of material and structure. (paper)

  16. Gunning for accuracy: Company targets human error with 'foolproof' perforating gun

    Energy Technology Data Exchange (ETDEWEB)

    Ross, E.

    2002-12-01

    An innovative new design for a scalloped expandable perforating gun is described. The gun is manufactured in Edmonton by LRI Perforating Systems, and it aimed at reducing the chances of human error that can result in sub-optimal performance. A perforating gun is used to pierce the well's casing to allow hydrocarbons to flow into the wellbore. It consists of a carrier, a pipe with an eighth-inch thick wall that protects the explosives downhole, and an inner tube containing the explosives. The LRI system has a unique interlocking mechanism for the end plates, which are attached to either end of the thin-walled charge holder tube, in addition to other advantageous features, including a price advantage of 10 to 15 per cent. Marketing strategy is designed to interest wi reline companies that focus on vertical well applications. 1 photo.

  17. Spontaneous external gallbladder perforation

    International Nuclear Information System (INIS)

    Noeldge, G.; Wimmer, B.; Kirchner, R.

    1981-01-01

    Spontaneous perforation of the gallbladder is one complication of cholelithiasis. There is a greater occurence of free perforation in the peritoneal cavity with bilary pertonitis, followed by the perforation into the stomach, small intestine and colon. A single case of the nowadays rare spontaneous perforation in and through the abdominal wall will be reported. Spontaneous gallbladder perforation appears nearly asymptomatic in its clinical course because of absent biliary peritonitis. (orig.) [de

  18. The Versatile Modiolus Perforator Flap

    DEFF Research Database (Denmark)

    Gunnarsson, Gudjon Leifur; Thomsen, Jorn Bo

    2016-01-01

    BACKGROUND: Perforator flaps are well established, and their usefulness as freestyle island flaps is recognized. The whereabouts of vascular perforators and classification of perforator flaps in the face are a debated subject, despite several anatomical studies showing similar consistency. In our...... experience using freestyle facial perforator flaps, we have located areas where perforators are consistently found. This study is focused on a particular perforator lateral to the angle of the mouth; the modiolus and the versatile modiolus perforator flap. METHODS: A cohort case series of 14 modiolus...... perforator flap reconstructions in 14 patients and a color Doppler ultrasonography localization of the modiolus perforator in 10 volunteers. RESULTS: All 14 flaps were successfully used to reconstruct the defects involved, and the location of the perforator was at the level of the modiolus as predicted...

  19. Analysis of Terminal Metallic Armor Plate Free-Surface Bulging

    National Research Council Canada - National Science Library

    Rapacki, Jr, E. J

    2008-01-01

    An analysis of the bulge formed on the free-surface of the terminal metallic plate of an armor array is shown to lead to reasonable estimates of the armor array's remaining penetration/perforation resistance...

  20. Control of the flow in the annular region of a shrouded cylinder with splitter plate

    Directory of Open Access Journals (Sweden)

    Ozkan Gokturk Memduh

    2017-01-01

    Full Text Available In the present study, the flow control with a splitter plate was studied considering the annular region of a shrouded cylinder. The effect of splitter plate angle, α which was defined according to the cylinder centreline is investigated experimentally in deep water using Particle image Velocimetry (PIV technique and flow visualization by dye injection method. The range of splitter plate angle was selected within 60°≤ α ≤180° with an increment of 30°. The porosity of the shroud which is a perforated cylinder was selected as β=0.7 in order to have larger fluid entrainment through the cylinder. The results were compared with the no-plate case and showed that the splitter plate located in the annular region of shrouded cylinders is effective on reducing the turbulence levels just behind the cylinder base, as well as the near wake of the perforated shroud.

  1. Control of the flow in the annular region of a shrouded cylinder with splitter plate

    Science.gov (United States)

    Ozkan, Gokturk Memduh; Durhasan, Tahir; Pinar, Engin; Yenicun, Arda; Akilli, Huseyin; Sahin, Besir

    In the present study, the flow control with a splitter plate was studied considering the annular region of a shrouded cylinder. The effect of splitter plate angle, α which was defined according to the cylinder centreline is investigated experimentally in deep water using Particle image Velocimetry (PIV) technique and flow visualization by dye injection method. The range of splitter plate angle was selected within 60°≤ α ≤180° with an increment of 30°. The porosity of the shroud which is a perforated cylinder was selected as β=0.7 in order to have larger fluid entrainment through the cylinder. The results were compared with the no-plate case and showed that the splitter plate located in the annular region of shrouded cylinders is effective on reducing the turbulence levels just behind the cylinder base, as well as the near wake of the perforated shroud.

  2. Estimation of effective elastic constants for grid plate

    International Nuclear Information System (INIS)

    Shibanuma, Kiyoshi; Kuriyama, Masaaki; Okumura, Yoshikazu

    1980-07-01

    This article contains a method of estimation for the effective elastic constants of a grid plate, which is a flat perforated plate with pipes for cooling. The elastic constants of the grid plate are formulated for two symmetric axes. In the case of using OFCu(E 0 = 12500 kg/mm 2 , ν 0 = 0.34) as the material of the grid, the results are given as follows. E sub(L) = 3180 kg/mm 2 , E sub(T) = 3860 kg/mm 2 upsilon sub(LT) = 0.12, upsilon sub(TL) = 0.15 (author)

  3. Premixed Combustion of Kapok (ceiba pentandra seed oil on Perforated Burner

    Directory of Open Access Journals (Sweden)

    I.K.G. Wirawan

    2014-05-01

    Full Text Available Availability of fossil fuels in the world decrease gradually due to excessive fuel exploitation. This situations push researcher to look for alternative fuels as a source of renewable energy, one of them is kapok (ceiba pentandra seed oil. The aim this study was to know the behavior of laminar burning velocity, secondary Bunsen flame with open tip, cellular and triple flame. Premixed combustion of kapok seed oil was studied experimentally on perforated burner with equivalence ratio (φ varied from 0.30 until 1.07. The results showed that combustion of glycerol requires a large amount of air so that laminar burning velocity (SL is the highest at very lean mixture (φ =0.36 in the form of individual Bunsen flame on each of the perforated plate hole.  Perforated and secondary Bunsen flame both reached maximum SL similar with that of ethanol and higher than that of hexadecane. Slight increase of φ decreases drastically SL of perforated and secondary Bunsen flame. When the mixture was enriched, secondary Bunsen and perforated flame disappears, and then the flame becomes Bunsen flame with open tip and triple flame (φ = 0.62 to 1.07. Flame was getting stable until the mixture above the stoichiometry. Being isolated from ambient air, the SL of perforated flame, as well as secondary Bunsen flame, becomes equal with non-isolated flame. This shows the decreasing trend of laminar burning velocity while φ is increasing. When the mixture was enriched island (φ = 0.44 to 0.48 and petal (φ = 0.53 to 0.62 cellular flame take place. Flame becomes more unstable when the mixture was changed toward stoichiometry.

  4. Salmonella intestinal perforation: (27 perforations in one patient, 14 perforations in another Are the goal posts changing?

    Directory of Open Access Journals (Sweden)

    Adeniran J

    2005-01-01

    Full Text Available The pathology of salmonellosis after a faeco-oral transmission was first clearly described by Jenner in 1850. Over the years, the pathological manifestations in different tissues of the body have been described. The ileum is however mostly involved leading to enlarged Peyer′s patches, ulceration, and sometimes bleeding and perforation. Efforts at control have largely been improvement in public water supply, safe disposal of waste, and general public health measures. Despite these measures, intestinal perforation from salmonellosis remains the commonest cause of emergency operation in children above 3 years. The incidence continues to rise, so also the mortality, despite new antibiotics and improvement in facilities in the hospitals. Even more disturbing is that we now see more perforations per patient, and more involvement of the colon. Three recently managed patients with multiple ileal/colonic perforations were reviewed. Presenting problems, delay in referral, choice of antibiotics and postoperative complications were noted. One patient had 27 perforations and another 14 perforations. Both survived. Is salmonella changing? Are our patients changing? Is the environment changing? Are the goal posts changing? This article details our recent experience with this dreadful disease, reviews the new literature and makes suggestions for the way forwards.

  5. Signal enhancement due to high-Z nanofilm electrodes in parallel plate ionization chambers with variable microgaps.

    Science.gov (United States)

    Brivio, Davide; Sajo, Erno; Zygmanski, Piotr

    2017-12-01

    We developed a method for measuring signal enhancement produced by high-Z nanofilm electrodes in parallel plate ionization chambers with variable thickness microgaps. We used a laboratory-made variable gap parallel plate ionization chamber with nanofilm electrodes made of aluminum-aluminum (Al-Al) and aluminum-tantalum (Al-Ta). The electrodes were evaporated on 1 mm thick glass substrates. The interelectrode air gap was varied from 3 μm to 1 cm. The gap size was measured using a digital micrometer and it was confirmed by capacitance measurements. The electric field in the chamber was kept between 0.1 kV/cm and 1 kV/cm for all the gap sizes by applying appropriate compensating voltages. The chamber was exposed to 120 kVp X-rays. The current was measured using a commercial data acquisition system with temporal resolution of 600 Hz. In addition, radiation transport simulations were carried out to characterize the dose, D(x), high-energy electron current, J(x), and deposited charge, Q(x), as a function of distance, x, from the electrodes. A deterministic method was selected over Monte Carlo due to its ability to produce results with 10 nm spatial resolution without stochastic uncertainties. Experimental signal enhancement ratio, SER(G) which we defined as the ratio of signal for Al-air-Ta to signal for Al-air-Al for each gap size, was compared to computations. The individual contributions of dose, electron current, and charge deposition to the signal enhancement were determined. Experimental signals matched computed data for all gap sizes after accounting for several contributions to the signal: (a) charge carrier generated via ionization due to the energy deposited in the air gap, D(x); (b) high-energy electron current, J(x), leaking from high-Z electrode (Ta) toward low-Z electrode (Al); (c) deposited charge in the air gap, Q(x); and (d) the decreased collection efficiency for large gaps (>~500 μm). Q(x) accounts for the electrons below 100 eV, which are

  6. A comparison of the electrochemical recovery of palladium using a parallel flat plate flow-by reactor and a rotating cylinder electrode reactor

    International Nuclear Information System (INIS)

    Terrazas-Rodriguez, J.E.; Gutierrez-Granados, S.; Alatorre-Ordaz, M.A.; Ponce de Leon, C.; Walsh, F.C.

    2011-01-01

    The production of catalytic converters generates large amounts of waste water containing Pd 2+ , Rh 3+ and Nd 3+ ions. The electrochemical treatment of these solutions offers an economic and effective alternative to recover the precious metals in comparison with other traditional metal recovery technologies. The separation of palladium from this mixture of metal ions by catalytic deposition was carried out using a rotating cylinder electrode reactor (RCER) and a parallel plate reactor (FM01-LC) with the same cathode area (64 cm 2 ) and electrolyte volume (300 cm 3 ). The study was carried out at mean linear flow velocities of 1.27 -1 (120 e /v -1 (7390 2+ ions in the parallel plate electrode reactor was 35% while the recovery of 97% of Pd 2+ in the RCER was 62%. The volumetric energy consumption during the electrolysis was 0.56 kW h m -3 and 2.1 kW h m -3 for the RCER and the FM01-LC reactors, respectively. Using a three-dimensional stainless steel electrode in the FM01-LC laboratory reactor, 99% of palladium ions were recovered after 30 min of electrolysis while in the RCER, 120 min were necessary.

  7. Investigation on the Acoustic Absorption of Flexible Micro-Perforated Panel with Ultra-Micro Perforations

    Science.gov (United States)

    Li, Guoxin; Tang, Xiaoning; Zhang, Xiaoxiao; Qian, Y. J.; Kong, Deyi

    2017-11-01

    Flexible micro-perforated panel has unique advantages in noise reduction due to its good flexibility compared with traditional rigid micro-perforated panel. In this paper, flexible micro-perforated panel was prepared by computer numerical control (CNC) milling machine. Three kinds of plastics including polyvinylchloride (PVC), polyethylene terephthalate (PET), and polyimide (PI) were taken as the matrix materials to prepare flexible micro-perforated panel. It has been found that flexible micro-perforated panel made of PET possessing good porosity and proper density, elastic modulus and poisson ratio exhibited the best acoustic absorption properties. The effects of various structural parameters including perforation diameter, perforation ratio, thickness and air gap have also been investigated, which would be helpful to the optimization of acoustic absorption properties.

  8. Device for filling tubular electrode plates for lead batteries. Vorrichtung zum Fuellen von Roehrchenelektrodenplatten fuer Bleiakkumulatoren

    Energy Technology Data Exchange (ETDEWEB)

    Barth, P.U.; Kubis, C.; Weber, H.J.; Wiepen, R.

    1984-11-22

    The device applies the vibration principle and according to the invention it uses a filling cassette for accommodating tubular electrode plates. The filling cassette has a filling funnel and is suspended with its vibration drive by springs. The vibration drive consists either of two out-of-balance motors, which are rigidly connected to the lower frame of the cassette, and have opposite directions of rotation, or of one out-of-balance motor, which is connected to a joint below the frame of the cassette.

  9. Manufacturing process for electrodes for ionizing radiation detectors

    International Nuclear Information System (INIS)

    Tirelli, M.G.; Hecquet, R.

    1987-01-01

    A manufacturing proces for electrodes for ionizing radiation detectors, particularly electrodes for X-ray multidetectors, is proposed. It consists of electrodepositing at least one layer of an electrically conducting material on at least one side of a relatively flat plate. A ductile material is used to form the conducting layer. The assembly formed by the plate covered by the ductile conducting material is subjected to pressing to crush the ductile conducting material at least in the zones where the assembly formed by the plate and the covering material has a total thickness superior to a constant thickness desired for the electrode [fr

  10. Plate performance in liquid-liquid extraction

    International Nuclear Information System (INIS)

    Wadkins, R.P.

    1984-01-01

    The relative effectiveness of perforated, nozzle, and burred plates from a capacity and extraction standpoint were studied in a pulsed liquid-liquid extraction system. The experiments were conducted in a 3.8 x 10 -2 m diameter column using a mixture of aluminum nitrate, nitric acid, and uranyl nitrate as the aqueous phase, and tributyl phosphate dissolved in AMSCO 125-90 W as the organic phase. The uranium was extracted from the aqueous phase to the organic phase. A standard cartridge was made for each type of plate and consisted of an assembly of plates spaced 5.08 x 10 -2 m apart. Each plate had 3.2 x 10 -3 m holes spaced on 6.1 x 10 -3 -m centers, and contained 23% free area. 16 references, 4 figures, 1 table

  11. Nickel hydrogen bipolar battery electrode design

    Science.gov (United States)

    Puglisi, V. J.; Russell, P.; Verrier, D.; Hall, A.

    1985-01-01

    The preferred approach of the NASA development effort in nickel hydrogen battery design utilizes a bipolar plate stacking arrangement to obtain the required voltage-capacity configuration. In a bipolar stack, component designs must take into account not only the typical design considerations such as voltage, capacity and gas management, but also conductivity to the bipolar (i.e., intercell) plate. The nickel and hydrogen electrode development specifically relevant to bipolar cell operation is discussed. Nickel oxide electrodes, having variable type grids and in thicknesses up to .085 inch are being fabricated and characterized to provide a data base. A selection will be made based upon a system level tradeoff. Negative (hydrpogen) electrodes are being screened to select a high performance electrode which can function as a bipolar electrode. Present nickel hydrogen negative electrodes are not capable of conducting current through their cross-section. An electrode was tested which exhibits low charge and discharge polarization voltages and at the same time is conductive. Test data is presented.

  12. Alkali ion migration between stacked glass plates by corona discharge treatment

    Energy Technology Data Exchange (ETDEWEB)

    Kawaguchi, Keiga [Research Institute for Electronic Science, Hokkaido University, N20 W10, Kita-ku, Sapporo, Hokkaido 001-0020 (Japan); Suzuki, Toshio [Research Center, Asahi Glass Co., Ltd., 1150 Hazawa-cho, Kanagawa-ku, Yokohama, Kanagawa 221-8755 (Japan); Ikeda, Hiroshi [Art, Science and Technology Center for Cooperative Research, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580 (Japan); Sakai, Daisuke [Department of Electrical and Electronic Engineering, Kitami Institute of Technology, 165 Koen-cho, Kitami, Hokkaido 090-8507 (Japan); Funatsu, Shiro; Uraji, Keiichiro [Production Technology Center, Asahi Glass Co., Ltd., 1-1 Suehiro-cyo, Tsurumiku, Yokohama, Kanagawa 230-0045 (Japan); Yamamoto, Kiyoshi [Research Center, Asahi Glass Co., Ltd., 1150 Hazawa-cho, Kanagawa-ku, Yokohama, Kanagawa 221-8755 (Japan); Harada, Kenji [Department of Computer Science, Kitami Institute of Technology, 165 Koen-cho, Kitami, Hokkaido 090-8507 (Japan); Nishii, Junji, E-mail: nishii@es.hokudai.ac.jp [Research Institute for Electronic Science, Hokkaido University, N20 W10, Kita-ku, Sapporo, Hokkaido 001-0020 (Japan)

    2015-05-30

    Highlights: • Two stacked glass plates with a 1 mm gap were treated by corona discharge. • Spatial migration of alkali ion over the gap was demonstrated. • Hydrogen gas was necessary for uniform migration. • Surface modification was done with this process without high temperature or vacuum. - Abstract: Corona discharge reflects the spatial migration of alkali ions over a gap between two glass plates. This study examined stacked glass plates containing different alkali ions treated with the corona discharge plasma generated by applied voltage of 4.5 kV at 200 °C. Protons generated at the anode electrode penetrate into the potassium-ion-containing upper glass plate, which is located 5 mm below the anode electrode. Potassium ions intruded into the lower glass plate containing sodium ions placed on the cathode electrode, even over a 1 mm gap separating the plates. Finally, the sodium ion discharged on the cathode electrode. The hydrogen atmosphere was effective at inhibiting the potassium ion reaction with ambient gases during the spatial migration between the two glass plates.

  13. Involvement of intracellular Zn2+ signaling in LTP at perforant pathway-CA1 pyramidal cell synapse.

    Science.gov (United States)

    Tamano, Haruna; Nishio, Ryusuke; Takeda, Atsushi

    2017-07-01

    Physiological significance of synaptic Zn 2+ signaling was examined at perforant pathway-CA1 pyramidal cell synapses. In vivo long-term potentiation (LTP) at perforant pathway-CA1 pyramidal cell synapses was induced using a recording electrode attached to a microdialysis probe and the recording region was locally perfused with artificial cerebrospinal fluid (ACSF) via the microdialysis probe. Perforant pathway LTP was not attenuated under perfusion with CaEDTA (10 mM), an extracellular Zn 2+ chelator, but attenuated under perfusion with ZnAF-2DA (50 μM), an intracellular Zn 2+ chelator, suggesting that intracellular Zn 2+ signaling is required for perforant pathway LTP. Even in rat brain slices bathed in CaEDTA in ACSF, intracellular Zn 2+ level, which was measured with intracellular ZnAF-2, was increased in the stratum lacunosum-moleculare where perforant pathway-CA1 pyramidal cell synapses were contained after tetanic stimulation. These results suggest that intracellular Zn 2+ signaling, which originates in internal stores/proteins, is involved in LTP at perforant pathway-CA1 pyramidal cell synapses. Because the influx of extracellular Zn 2+ , which originates in presynaptic Zn 2+ release, is involved in LTP at Schaffer collateral-CA1 pyramidal cell synapses, synapse-dependent Zn 2+ dynamics may be involved in plasticity of postsynaptic CA1 pyramidal cells. © 2017 Wiley Periodicals, Inc.

  14. Differentiation of Acute Perforated from Non-Perforated Appendicitis: Usefulness of High-Resolution Ultrasonography

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Gyu Chang [Dept. of Radiology, Gumi Hospital, Soonchunhyang University College of Medicine, Gumi (Korea, Republic of)

    2011-07-15

    To evaluate the usefulness of high-resolution ultrasonography (US) for the differentiation of acute perforated appendicitis from non-perforated appendicitis. The high-resolution US features in 96 patients (49 males, 47 females; mean age, 33.8 years; age range, 4-80 years) with pathologically proven acute appendicitis were evaluated. The following US findings were evaluated for differentiation of acute perforated appendicitis from non-perforated appendicitis: circumferential loss of the echogenic submucosal layer, periappendiceal fluid collection, disruption of the serosal layer, asymmetrical wall thickening, maximum overall diameter > 10.5 mm, and the presence of appendicoliths. The sensitivity and specificity of the US features in the diagnosis of acute perforated appendicitis were calculated. All of the US findings, except for appendicoliths, were significantly more common in the acute perforated appendicitis group (p < 0.001). The sensitivity of circumferential loss of the echogenic submucosal layer, periappendiceal fluid collection, disruption of the serosal layer, asymmetrical wall thickening, maximum overall diameter > 10.5 mm, and the presence of appendicoliths was 85.4, 73.2, 68.3, 70.7, 80.5, and 36.6%, respectively, while the specificity was 65.5, 89.1, 96.4, 98.2, 81.8, and 80.0%, respectively. High-resolution US was found to be useful for differentiating acute perforated appendicitis from non-perforated appendicitis.

  15. Nontraumatic terminal ileal perforation

    Directory of Open Access Journals (Sweden)

    Wani Rauf A

    2006-03-01

    Full Text Available Abstract Background There is still confusion and controversy over the diagnosis and optimal surgical treatment of non traumatic terminal ileal perforation-a cause of obscure peritonitis. Methods This study was a prospective study aimed at evaluating the clinical profile, etiology and optimal surgical management of patients with nontraumatic terminal ileal perforation. Results There were 79 cases of nontraumatic terminal ileal perforation; the causes for perforation were enteric fever(62%, nonspecific inflammation(26%, obstruction(6%, tuberculosis(4% and radiation enteritis (1%. Simple closure of the perforation (49% and end to side ileotransverse anastomosis(42% were the mainstay of the surgical management. Conclusion Terminal ileal perforation should be suspected in all cases of peritonitis especially in developing countries and surgical treatment should be optimized taking various accounts like etiology, delay in surgery and operative findings into consideration to reduce the incidence of deadly complications like fecal fistula.

  16. Analysis of the influence of the cutting edge geometry on parameters of the perforation process for conveyor and transmission belts

    Directory of Open Access Journals (Sweden)

    Wojtkowiak Dominik

    2018-01-01

    Full Text Available Perforated belts, which are used in vacuum conveyor belts, can have significantly different mechanical properties like strength and elasticity due to a variety of used materials and can have different thickness from very thin (0,7 mm to thick belts (6 mm. In order to design a complex machine for mechanical perforation, which can perforate whole range of belts, it is necessary to research the influence of the cutting edge geometry on the parameters of the perforation process. Three most important parameters, which describe the perforation process are the cutting force, the velocity and the temperature of the piercing punch. The results presented in this paper consider two different types of punching (a piercing punch with the punching die or with the reducer plate and different cutting edge directions, angles, diameters and material properties. Test were made for different groups of composites belts – with polyurethane and polyester fabric, polyamide core or aramid-fibre reinforced polymers. The main goal of this research is to specify effective tools and parameters of the perforation process for each group of composites belts.

  17. Reactive perforating collagenosis

    Directory of Open Access Journals (Sweden)

    Yadav Mukesh

    2009-01-01

    Full Text Available Reactive perforating collagenosis is a rare cutaneous disorder of unknown etiology. We hereby describe a case of acquired reactive perforating collagenosis in a patient of diabetes and chronic renal failure.

  18. Combining rhinoplasty with septal perforation repair.

    Science.gov (United States)

    Foda, Hossam M T; Magdy, Emad A

    2006-11-01

    A combined septal perforation repair and rhinoplasty was performed in 80 patients presenting with septal perforations (size 1 to 5 cm) and external nasal deformities. The external rhinoplasty approach was used for all cases and the perforation was repaired using bilateral intranasal mucosal advancement flaps with a connective tissue interposition graft in between. Complete closure of the perforation was achieved in 90% of perforations of size up to 3.5 cm and in only 70% of perforations that were larger than 3.5 cm. Cosmetically, 95% were very satisfied with their aesthetic result. The external rhinoplasty approach proved to be very helpful in the process of septal perforation repair especially in large and posteriorly located perforations and in cases where the caudal septal cartilage was previously resected. Our results show that septal perforation repair can be safely combined with rhinoplasty and that some of the routine rhinoplasty maneuvers, such as medial osteotomies and dorsal lowering, could even facilitate the process of septal perforation repair.

  19. Study of the effect of water vapor on a resistive plate chamber with glass electrodes

    CERN Document Server

    Sakai, H H; Teramoto, Y; Nakano, E E; Takahashi, T T

    2002-01-01

    We studied the effects of water vapor on the efficiencies of resistive plate chambers with glass electrodes, operated in the streamer mode. With moisture in the chamber gas that has freon as a component (water vapor approx 1000 ppm), a decrease in the efficiency (approx 20%) has been observed after operating for a period of several weeks to a few months. From our study, the cause of the efficiency decrease was identified as a change on the cathode surface. In addition, a recovery method was found: flushing for 1 day with argon bubbled through water containing >=3% ammonia, followed by a few weeks of training with dry gas.

  20. Spectrum of Perforation Peritonitis

    Science.gov (United States)

    Chakma, Sujit M.; Singh, Rahul L.; Parmekar, Mahadev V.; Singh, K.H. Gojen; Kapa, Buru; Sharatchandra, K.H.; Longkumer, Amenla T.; Rudrappa, Santhosh

    2013-01-01

    Introduction: Perforation peritonitis mostly results from the perforation of a diseased viscus. Other causes of perforation include abdominal trauma, ingestion of sharp foreign body and iatrogenic perforation. The diagnosis is mainly based on clinical grounds. Plain abdominal X-rays (erect) may reveal dilated and oedematous intestines with pneumoperitoneum. Ultrasound and CT scan may diagnose up to 72% and 82% of perforation respectively. The present study was carried out to study various etiological factors, modes of clinical presentation, morbidity and mortality patterns of perforation peritonitis presented in the RIMS hospital, Imphal, India. Material and Methods: The study was conducted from September 2010 to August 2012 on 490 cases of perforation peritonitis admitted and treated in the Department of Surgery. Initial diagnosis was made on the basis of detailed history, clinical examination and presence of pneumoperitoneum on erect abdominal X-ray. Results: A total of 490 patients of perforation peritonitis were included in the study, with mean age of 48.28 years. 54.29% patients were below 50 years and 45.71% patients were above 50 years. There were 54.29% male patients and 45.71% female patients. Only 30% patients presented within 24 hours of onset of symptoms, 31.43% patients presented between 24 to 72 hours and 38.57% patients presented 72 hours after the onset of symptoms. Mean duration of presentation was 54.7 hours. Overall 469 patients were treated surgically and 21 patients were managed conservatively. Overall morbidity and mortality recorded in this study were 52.24% and 10% respectively. PMID:24392388

  1. Perforations during contrast enema

    International Nuclear Information System (INIS)

    Vogel, H.; Steinkamp, U.; Grabbe, E.; Allgemeines Krankenhaus Ochsenzoll, Hamburg

    1983-01-01

    During contrast enema, perforation into the retroperitoneal space can be differentiated from perforation into the peritoneum and perforation into the intestinal wall associated with formation of barium granulomas or submucosal spreading of the contrast medium. Other special forms are perforation with contrast medium embolism of diverticula; of the processus vermiformis; penetration of contrast medium into fistulous systems and from the operated areas. Risk factors are: balloon catheter, intestinal tubes with a hard tip, preternatural anus, excessive enema pressure, contrast medium additions, preceding manipulations, intestinal diseases, advanced age and delegation of manipulations to assistants and unskilled staff. Children are particularly at risk. (orig.) [de

  2. The freestyle pedicle perforator flap

    DEFF Research Database (Denmark)

    Gunnarsson, Gudjon Leifur; Jackson, Ian T; Westvik, Tormod S

    2015-01-01

    BACKGROUND: Perforating vessels are a consistent anatomical finding and well described in the current literature. Any skin flap can be raised on a subcutaneous pedicle as long as it contains at least one supplying perforator. Perforator flaps have been interlinked with microsurgery and generally...... not widely performed by the general plastic surgeons. The aim of this paper is to present the simplicity of pedicled perforator flap reconstruction of moderate-sized defects of the extremities and torso. METHODS: We retrospectively reviewed the charts of 34 patients reconstructed using 34 freestyle pedicled...... perforator flaps for moderate-sized defects of the truncus and extremities. We registered indications, flap size and localization, success rate, and complications. Most importantly, we describe a simple approach to the design of freestyle pedicled perforator flaps and elaborate on technical aspects...

  3. Rough Electrode Creates Excess Capacitance in Thin-Film Capacitors.

    Science.gov (United States)

    Torabi, Solmaz; Cherry, Megan; Duijnstee, Elisabeth A; Le Corre, Vincent M; Qiu, Li; Hummelen, Jan C; Palasantzas, George; Koster, L Jan Anton

    2017-08-16

    The parallel-plate capacitor equation is widely used in contemporary material research for nanoscale applications and nanoelectronics. To apply this equation, flat and smooth electrodes are assumed for a capacitor. This essential assumption is often violated for thin-film capacitors because the formation of nanoscale roughness at the electrode interface is very probable for thin films grown via common deposition methods. In this work, we experimentally and theoretically show that the electrical capacitance of thin-film capacitors with realistic interface roughness is significantly larger than the value predicted by the parallel-plate capacitor equation. The degree of the deviation depends on the strength of the roughness, which is described by three roughness parameters for a self-affine fractal surface. By applying an extended parallel-plate capacitor equation that includes the roughness parameters of the electrode, we are able to calculate the excess capacitance of the electrode with weak roughness. Moreover, we introduce the roughness parameter limits for which the simple parallel-plate capacitor equation is sufficiently accurate for capacitors with one rough electrode. Our results imply that the interface roughness beyond the proposed limits cannot be dismissed unless the independence of the capacitance from the interface roughness is experimentally demonstrated. The practical protocols suggested in our work for the reliable use of the parallel-plate capacitor equation can be applied as general guidelines in various fields of interest.

  4. Free vibration analysis of rectangular plates with central cutout

    Directory of Open Access Journals (Sweden)

    Kanak Kalita

    2016-12-01

    Full Text Available A nine-node isoparametric plate element in conjunction with first-order shear deformation theory is used for free vibration analysis of rectangular plates with central cutouts. Both thick and thin plate problems are solved for various aspect ratios and boundary conditions. In this article, primary focus is given to the effect of rotary inertia on natural frequencies of perforated rectangular plates. It is found that rotary inertia has significant effect on thick plates, while for thin plates the rotary inertia term can be ignored. It is seen that the numerical convergence is very rapid and based on comparison with experimental and analytical data from literature, it is proposed that the present formulation is capable of yielding highly accurate results. Finally, some new numerical solutions are provided here, which may serve as benchmark for future research on similar problems.

  5. CT in acute perforated sigmoid diverticulitis

    International Nuclear Information System (INIS)

    Lohrmann, Christian; Ghanem, Nadir; Pache, Gregor; Makowiec, Frank; Kotter, Elmar; Langer, Mathias

    2005-01-01

    Background: To assess the value of computed tomography (CT) in patients with acute perforated sigmoid diverticulitis in correlation with the Hinchey classification of perforated diverticular disease. Methods: Thirty patients with acute perforated sigmoid diverticulitis underwent computed tomography prior to surgery. Computed tomography scans were compared with the surgical and histopathological reports, utilizing the Hinchey classification. Results: In 28 of the 30 (93%) patients examined, the Hinchey stage was correctly determined by means of computed tomography. One patient with Hinchey stage IV was falsely classified as Hinchey stage III, and one patient with Hinchey stage III as Hinchey stage II. Computed tomography revealed 12 out of 14 (86%) patients with perforation sites and 3 out of 3 (100%) patients with contained perforation. In one of 17 (6%) patients with surgically or histopathologically proven perforation or contained perforation, a bowel wall discontinuity was revealed by computed tomography. In 6 of the 17 (35%) patients with surgical or histopathological perforation or contained perforation, extraluminal contrast material was detected by computed tomography. Conclusions: Computed tomography is a valuable imaging tool for determining the degree of acute perforated sigmoid diverticulitis, by means of which patients can be stratified according to the severity of the disease; furthermore, this tool is of assistance in surgical planning

  6. High-Resolution Ultrasonography (US) of Appendiceal Specimens: Differentiation of Acute Non-perforated Appendicitis from Perforated Appendicitis

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Gyo Chang; Kim, Suk; Im, Han Hyeok; Lee, Sang Jin; Yang, Seung Boo; Lee, Seung Woo; Kim, Il Young [Soonchunhyang University Gumi Hospital, Gumi (Korea, Republic of); Lee, Hae Kyung [Soonchunhyang University Bucheon Hospital, Bucheon (Korea, Republic of); Kwon, Kui Hyang; Shin, Hyung Chul [Soonchunhyang University, College of Medicine, Seoul (Korea, Republic of)

    2007-09-15

    To analyze surgical specimens from patients with acute non-perforated and perforated appendicitis using high-resolution ultrasonography (US), and to correlate the US features with the pathologic findings. One hundred and six surgical appendix specimens obtained from patients with suspected acute appendicitis were evaluated. The following US features were evaluated for differentiating acute non-perforated appendicitis from perforated appendicitis: circumferential loss of the echogenic submucosal layer, disruption of the serosal layer, asymmetrical wall thickening, the sum of opposing walls {>=} 9 mm and the presence of appendicoliths. The sensitivity and specificity of the US findings for diagnosing perforated appendicitis were determined. All US features were detected significantly more often in the perforated appendicitis group of specimens. The disruption of the serosal layer was the most significant independent predictor of perforation (p < .001). The sensitivity for circumferential loss of the echogenic submucosal layer, disruption of the serosal layer, asymmetrical wall thickening, wall thickness {>=} 9 mm, and the presence of appendicoliths individually was 84.6%, 69.2%, 61.5%, 73.1% and 46.2%, respectively. The specificity for all of these findings was 86.3%, 98.7%, 95.0%, 85.0% and 85.0%, respectively. High-resolution US of appendiceal specimens was very useful for differentiating acute non-perforated from perforated appendicitis

  7. Thickness resonances dispersion characteristics of a lossy piezoceramic plate with electrodes of arbitrary conductivity.

    Science.gov (United States)

    Mezheritsky, Alex A; Mezheritsky, Alex V

    2007-12-01

    A theoretical description of the dissipative phenomena in the wave dispersion related to the "energytrap" effect in a thickness-vibrating, infinite thicknesspolarized piezoceramic plate with resistive electrodes is presented. The three-dimensional (3-D) equations of linear piezoelectricity were used to obtain symmetric and antisymmetric solutions of plane harmonic waves and investigate the eigen-modes of thickness longitudinal (TL) up to third harmonic and shear (TSh) up to ninth harmonic vibrations of odd- and even-orders. The effects of internal and electrode energy dissipation parameters on the wave propagation under regimes ranging from a short-circuit (sc) condition through RC-type relaxation dispersion to an opencircuit (oc) condition are examined in detail for PZT piezoceramics with three characteristic T -mode energy-trap figure-of-merit c-(D)(33)/c-(E)(44) values - less, near equal and higher 4 - when the second harmonic spurious TSh resonance lies below, inside, and above the fundamental TL resonanceantiresonance frequency interval. Calculated complex lateral wave number dispersion dependences on frequency and electrode resistance are found to follow the universal scaling formula similar to those for dielectrics characterization. Formally represented as a Cole-Cole diagram, the dispersion branches basically exhibit Debye-like and modified Davidson Cole dependences. Varying the dissipation parameters of internal loss and electrode conductivity, the interaction of different branches was demonstrated by analytical and numerical analysis. For the purposes of dispersion characterization of at least any thickness resonance, the following theorem was stated: the ratio of two characteristic determinants, specifically constructed from the oc and sc boundary conditions, in the limit of zero lateral wave number, is equal to the basic elementary-mode normalized admittance. As was found based on the theorem, the dispersion near the basic and nonbasic TL and TSh

  8. Re: Bone heat generated using conventional implant drills versus piezosurgery unit during apical cortical plate perforation. Lajolo C, Valente NA, Romandini WG, Petruzzi M, Verdugo F, D'Addona A. (J Periodontol. 2018 Mar 9. https://doi.org/10.1002/JPER.17-0502. [Epub ahead of print]).

    Science.gov (United States)

    Stacchi, Claudio; Robiony, Massimo; Jones, Jason Motta; Lombardi, Teresa; Verardi, Simone

    2018-05-26

    We read with great interest the article recently published by Dr. Lajolo et al, in which the authors compared conventional implant drills and piezoelectric technique during apical cortical plate perforation. Precisely, the aim of this study was to evaluate temperature variations occurring during implant site preparation at the apical cortical plate level of a porcine rib ex vivo model, by using the two aforementioned devices and different pressure loads. This article is protected by copyright. All rights reserved. © 2018 American Academy of Periodontology.

  9. Management of biliary perforation in children

    Directory of Open Access Journals (Sweden)

    Mirza Bilal

    2010-01-01

    Full Text Available Background: To study the aetiology, management and outcome of biliary perforations in paediatric age group. Patients and Methods: In a retrospective study, the records of patients presented with biliary peritonitis due to biliary perforations, managed from March 2006 to July 2009, are reviewed. Results: Eight male patients with biliary peritonitis due to biliary perforation were managed. These patients were divided in two groups, A and B. Group A, (n = 3 patients, had common bile duct (CBD perforation, and Group B (n=5 patients had gallbladder perforation. The presenting features were abdominal pain, fever, abdominal distension, vomiting, constipation, jaundice and signs of peritonism. The management of CBD perforations in Group A was by draining the site of perforation and biliary diversion (tube cholecystostomy. In Group B, the gallbladder perforations were managed by tube cholecystostomy in four patients and cholecystectomy in one patient, however, one patient had to be re-explored and cholecystectomy performed due to complete necrosis of gall bladder. There was no mortality in our series. All patients were asymptomatic on regular follow-up. Conclusion: Early optimal management of biliary perforations remarkably improved the very high mortality and morbidity that characterised this condition in the past.

  10. Design of pulsed perforated-plate columns for industrial scale mass transfer applications - present experience and the need for a model based approach

    International Nuclear Information System (INIS)

    Roy, Amitava

    2010-01-01

    Mass transfer is a vital unit operation in the processing of spent nuclear fuel in the backend of closed fuel cycle and Pulsed perforated plate extraction columns are used as mass transfer device for more than five decades. The pulsed perforated plate column is an agitated differential contactor, which has wide applicability due to its simplicity, high mass transfer efficiency, high through put, suitability for maintenance free remote operation, ease of cleaning/decontamination and cost effectiveness. Design of pulsed columns are based on a model proposed to describe the hydrodynamics and mass transfer. In equilibrium stage model, the HETS values are obtained from pilot plant experiments and then scaled empirically to design columns for industrial application. The dispersion model accounts for mass transfer kinetics and back-mixing. The drop population balance model can describe complex hydrodynamics of dispersed phase, that is, drop formation, break-up and drop-to-drop interactions. In recent years, significant progress has been made to model pulsed columns using CFD, which provides complete mathematical description of hydrodynamics in terms of spatial distribution of flow fields and 3D visualization. Under the condition of pulsation, the poly-dispersed nature of turbulent droplet swarm renders modeling difficult. In the absence of industry acceptance of proposed models, the conventional chemical engineering practice is to use HETS-NTS concept or HTU-NTU approach to design extraction columns. The practicability of HTU-NTU approach has some limitations due to the lack of experimental data on individual film mass transfer coefficients. Presently, the HETS-NTS concept has been used for designing the columns, which has given satisfactory performance. The design objective is mainly to arrive at the diameter and height of the mass transfer section for a specific plate geometry, fluid properties and pulsing condition to meet the intended throughput (capacity) and mass

  11. The fabrication and characterization of an ex situ plated lead film electrode prepared with the use of a reversibly deposited mediator metal

    International Nuclear Information System (INIS)

    Tyszczuk, Katarzyna

    2011-01-01

    Research highlights: → The lead film electrode prepared with use of the mediator metal was elaborated. → The lead-based sensors were characterized by optical and voltammetric methods. → The adsorptive system of folic acid was employed to investigate a new electrode. → The application of the mediator metal improved properties of a lead film electrode. - Abstract: In this paper an ex situ plated lead film electrode prepared with use of the mediator metal (Zn) was elaborated. The electrochemical method for lead film formation is based on a co-deposition of a metal of interest (Pb) with a reversibly deposited mediator metal (Zn) and then on an oxidation of zinc and further deposition of lead by the appropriate potential. This serves to increase the density of islands of lead atoms, promoting lead film growth. The lead-based sensors were characterized by optical method (atomic force microscopy (AFM)) and as well as cyclic, linear sweep and square wave voltammetry. The adsorptive system of folic acid was employed to investigate the electrochemical characteristics a novel type of lead film electrode. Well-formed stripping peaks and a linear dependence of the stripping current on the folic acid concentration were observed on the lead film electrode prepared with use of the mediator metal while comparative measurements attempted with the lead film electrode prepared without use of the mediator metal were unsuccessful.

  12. Complexing agent and heavy metal removals from metal plating effluent by electrocoagulation with stainless steel electrodes.

    Science.gov (United States)

    Kabdaşli, Işik; Arslan, Tülin; Olmez-Hanci, Tuğba; Arslan-Alaton, Idil; Tünay, Olcay

    2009-06-15

    In the present study, the treatability of a metal plating wastewater containing complexed metals originating from the nickel and zinc plating process by electrocoagulation using stainless steel electrodes was experimentally investigated. The study focused on the effect of important operation parameters on electrocoagulation process performance in terms of organic complex former, nickel and zinc removals as well as sludge production and specific energy consumption. The results indicated that increasing the applied current density from 2.25 to 9.0 mA/cm(2) appreciably enhanced TOC removal efficiency from 20% to 66%, but a further increase in the applied current density to 56.25 mA/cm(2) did not accelerate TOC removal rates. Electrolyte concentration did not affect the process performance significantly and the highest TOC reduction (66%) accompanied with complete heavy metal removals were achieved at the original chloride content ( approximately 1500 mg Cl/L) of the wastewater sample. Nickel removal performance was adversely affected by the decrease of initial pH from its original value of 6. Optimum working conditions for electrocoagulation of metal plating effluent were established as follows: an applied current density of 9 mA/cm(2), the effluent's original electrolyte concentration and pH of the composite sample. TOC removal rates obtained for all electrocoagulation runs fitted pseudo-first-order kinetics very well (R(2)>92-99).

  13. Fuel cell end plate structure

    Science.gov (United States)

    Guthrie, Robin J.; Katz, Murray; Schroll, Craig R.

    1991-04-23

    The end plates (16) of a fuel cell stack (12) are formed of a thin membrane. Pressure plates (20) exert compressive load through insulation layers (22, 26) to the membrane. Electrical contact between the end plates (16) and electrodes (50, 58) is maintained without deleterious making and breaking of electrical contacts during thermal transients. The thin end plate (16) under compressive load will not distort with a temperature difference across its thickness. Pressure plate (20) experiences a low thermal transient because it is insulated from the cell. The impact on the end plate of any slight deflection created in the pressure plate by temperature difference is minimized by the resilient pressure pad, in the form of insulation, therebetween.

  14. Early Management Experience of Perforation after ERCP

    Directory of Open Access Journals (Sweden)

    Guohua Li

    2012-01-01

    Full Text Available Background and Aim. Perforation after endoscopic retrograde cholangiopancreatography (ERCP is a rare complication, but it is associated with significant mortality. This study evaluated the early management experience of these perforations. Patients and Methods. Between November 2003 and December 2011, a total of 8504 ERCPs were performed at our regional endoscopy center. Sixteen perforations (0.45% were identified and retrospectively reviewed. Results. Nine of these 16 patients with perforations were periampullary, 3 duodenal, 1 gastric fundus, and 3 patients had a perforation of an afferent limb of a Billroth II anastomosis. All patients with perforations were recognized during ERCP by X-ray and managed immediately. One patient with duodenal perforation and three patients with afferent limb perforation received surgery, others received medical conservative treatment which included suturing lesion, endoscopic nasobiliary drainage (ENBD, endoscopic retrograde pancreatic duct drainage (ERPD, gastrointestinal decompression, fasting, broad-spectrum antibiotics, and so on. All patients with perforation recovered successfully. Conclusions. We found that: (1 the diagnosis of perforation during ERCP may be easy, but you must pay attention to it. (2 Most retroperitoneal perforations can recover with only medical conservative treatment in early phase. (3 Most peritoneal perforations need surgery unless you can close the lesion up under endoscopy in early phase.

  15. The Perforation-Operation time Interval; An Important Mortality Indicator in Peptic Ulcer Perforation.

    Science.gov (United States)

    Surapaneni, Sushama; S, Rajkumar; Reddy A, Vijaya Bhaskar

    2013-05-01

    To find out the significance of the Perforation-Operation Interval (POI) with respect to an early prognosis, in patients with peritonitis which is caused by peptic ulcer perforation. Case series. Place and Duration of the Study: Department of General Surgery, Konaseema Institute of Medical Sciences and RF Amalapuram, Andhra Pradesh, India from 2008-2011. This study included 150 patients with generalized peritonitis, who were diagnosed to have Perforated Peptic Ulcers (PPUs). The diagnosis of the PPUs was established on the basis of the history , the clinical examination and the radiological findings. The perforation-operation interval was calculated from the time of onset of the symptoms like severe abdominal pain or vomiting till the time the patient was operated. Out of the 150 patients 134 were males and 16 were females, with a male : female ratio of 9:1. Their ages ranged between 25-70 years. Out of the 150 patients, 65 patients (43.3%) presented within 24 hours of the onset of severe abdominal pain (Group A), 27 patients (18%) presented between 24-48 hours of the onset of severe abdominal pain (Group B) and 58 patients (38.6%) presented after 48 hours. There was no mortality in Group A and the morbidity was more in Group B and Group C. There were 15 deaths in Group C. The problem of peptic ulcer perforation with its complication, can be decreased by decreasing the perforation -operation time interval, which as per our study, appeared to be the single most important mortality and morbidity indicator in peptic ulcer perforation.

  16. Characterization of hierarchical α-MoO3 plates toward resistive heating synthesis: electrochemical activity of α-MoO3/Pt modified electrode toward methanol oxidation at neutral pH

    Science.gov (United States)

    Filippo, Emanuela; Baldassarre, Francesca; Tepore, Marco; Guascito, Maria Rachele; Chirizzi, Daniela; Tepore, Antonio

    2017-05-01

    The growth of MoO3 hierarchical plates was obtained by direct resistive heating of molybdenum foils at ambient pressure in the absence of any catalysts and templates. Plates synthesized after 60 min resistive heating typically grow in an single-crystalline orthorhombic structure that develop preferentially in the [001] direction, and are characterized by high resolution transmission electron microscopy, selected area diffraction pattern and Raman-scattering measurements. They are about 100-200 nm in thickness and a few tens of micrometers in length. As heating time proceeds to 80 min, plates of α-MoO3 form a branched structure. A more attentive look shows that primary plates formed at until 60 min could serve as substrates for the subsequent growth of secondary belts. Moreover, a full electrochemical characterization of α-MoO3 plates on platinum electrodes was done by cyclic voltammetric experiments, at pH 7 in phosphate buffer, to probe the activity of the proposed composite material as anode to methanol electro-oxidation. Reported results indicate that Pt MoO3 modified electrodes are appropriate to develop new an amperometric non-enzymatic sensor for methanol as well as to make anodes suitable to be used in direct methanol fuel cells working at neutral pH.

  17. Modeling the hydrodynamics of Phloem sieve plates

    DEFF Research Database (Denmark)

    Jensen, Kaare Hartvig; Mullendore, Daniel Leroy; Holbrook, Noel Michele

    2012-01-01

    Sieve plates have an enormous impact on the efficiency of the phloem vascular system of plants, responsible for the distribution of photosynthetic products. These thin plates, which separate neighboring phloem cells, are perforated by a large number of tiny sieve pores and are believed to play...... understood. We propose a theoretical model for quantifying the effect of sieve plates on the phloem in the plant, thus unifying and improving previous work in the field. Numerical simulations of the flow in real and idealized phloem channels verify our model, and anatomical data from 19 plant species...... a crucial role in protecting the phloem sap from intruding animals by blocking flow when the phloem cell is damaged. The resistance to the flow of viscous sap in the phloem vascular system is strongly affected by the presence of the sieve plates, but the hydrodynamics of the flow through them remains poorly...

  18. Cell with scrolled electrodes. Uzumaki jo denkyokutai wo sonaeta denchi

    Energy Technology Data Exchange (ETDEWEB)

    Kamibayashi, M.; Morioka, Y. (Sanyo Electric Co. Ltd., Osaka (Japan))

    1990-10-03

    Non-sintered electrode plates produced by direct filling of paste state active materials in metal fiber felt type porous body are proposed recently for use as electrode plates for alkali cells and the like. Although this type of electrode plates can be produced with a simple facility because sintering process is not required, it has a shorcoming of internal short circuiting because metal fibers pass through the separator due to fuzzing of metal fiber. According to this invention, a sheet comprising metallic fibers oriented at right angles against the scrolled direction of the electrode plate is stacked on the surface of the metal fiber felt type porous body sheet when it is scrolled with the interposed separator. As the result, fibers are not bent and does not protrude from the surface of sheet to pass through the separator because each metallic fiber comprising the metallic sheet on the surface are arranged at a right angle against the direction of scrolling of the porous sheet. 2 figs., 1 tab.

  19. Scoring system for differentiating perforated and non-perforated pediatric appendicitis.

    Science.gov (United States)

    Blumfield, Einat; Yang, Daniel; Grossman, Joshua

    2017-10-01

    Appendicitis is the most common indication for emergency pediatric surgery and its most significant complication is perforation. Perforated appendicitis (PA) may be managed conservatively, whereas non-perforated appendicitis (NP) is managed surgically. Recent studies have shown that ultrasound (US) is effective for differentiating between PA and NP, and does not expose pediatric patients to ionizing radiation. The purpose of this study is to enhance the accuracy of differentiation with a novel scoring system based on clinical, laboratory, and US findings. This retrospective study included 243 patients aged 2-17 years who presented between 2006 and 2013 with surgically proven appendicitis, of whom 60 had perforation. Clinical and laboratory data were collected and US images evaluated by a pediatric radiologist. To create the scoring system, point values were assigned to each parameter. A randomly selected training sample of 137 subjects was used to create a scoring prediction model. The model was tested on the remaining 106 patients. Scores of ≥6, ≥11, and ≥15 yielded specificities of 64, 91, and 99%, and sensitivities of 96, 61, and 29%, respectively (p < 0.001). We have designed a scoring system incorporating clinical, laboratory, and sonographic findings which can differentiate PA from NP with high specificity.

  20. Dimensional changes of alginate impression by using perforated and non-perforated ring trays

    Directory of Open Access Journals (Sweden)

    Sumadhi Sastrodihardjo

    2010-03-01

    Full Text Available Dimensional changes are a common occurrence in impressions, either during or after impression taking. It produces a difference in the dimensions of the object and the model, which leads to the restoration being ill-fitted. Several causal factors have been proposed such as friction between the impression material and the teeth, the bulk of the impression material, the type of impression materials used, the impression technique, the pouring time and many others. The exact causal factor is still unknown and the dimensional change mechanism is still poorly understood. The objective of this research was to investigate the role of the perforation on the ring trays in producing dimensional changes in the impression by using perforated and non-perforated ring trays. Alginate impressions were made on the frustum of cone metal master die with a 7.08 mm base diameter, 7.03 mm top diameter and 9.23 mm height using perforated and non-perforated ring trays with 9.40 mm in diameter and 14.17 mm in height. The dimensional change was determined by comparing the dimension of the dental stone die and its metal master die. The results showed that the percentage of dimensional changes that occurred by using perforated ring tray were (+ 0.56±0.40 on the top area, (- 3.54±2.92 on base area and (+ 1.54±0.83 in height, respectively. As compared to using non-perforated ring trays, the percentage of dimensional changes that occurred were (- 0.49±0.49 on top area, (- 8.76±3.95 on base area and (+ 1.19±0.71 in height, respectively. There was a significant difference in the direction of the dimensional changes on both the top areas, but not in the base areas and height.

  1. Delta neutrophil index: A reliable marker to differentiate perforated appendicitis from non-perforated appendicitis in the elderly.

    Science.gov (United States)

    Shin, Dong Hyuk; Cho, Young Suk; Kim, Yoon Sung; Ahn, Hee Cheol; Oh, Young Taeck; Park, Sang O; Won, Moo-Ho; Cho, Jun Hwi; Kim, Young Myeong; Seo, Jeong Yeol; Lee, Young Hwan

    2018-01-01

    Delta neutrophil index (DNI) is a new inflammatory marker and the present study aimed to evaluate the predictive value of the DNI for the presence of a perforation in elderly with acute appendicitis. This retrospective observational study was conducted on 108 consecutive elderly patients (≥65 years old) with acute appendicitis treated over a 24-month period. Sixty-nine of the 108 patients (median, IQR: 72, 67-77 years) were allocated to the perforated appendicitis group (63.9%) and 39 to the non-perforated appendicitis group (36.1%). WBC, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio and DNI were significantly higher in the perforated group. In multiple logistic regression analyses, initial DNI was the only independent marker that can significantly predict the presence of perforation in multiple regression [odds ratio 9.38, 95% confidence interval (2.51-35.00), P=.001]. Receiver operator characteristic curve analysis showed that DNI is a good predictor for the presence of appendiceal perforation at an optimal cut-off for DNI being 1.4% (sensitivity 67.7%, specificity 90.0%, AUC 0.807). Clinicians can reliably differentiate acute perforated appendicitis from non-perforated appendicitis by DNI level of 1.4 or more in elderly patients. © 2017 Wiley Periodicals, Inc.

  2. CT findings of exophageal perforation

    Energy Technology Data Exchange (ETDEWEB)

    Heo, Jeong Nam; Choi, Yo Won; Jeon, Seok Chol; Park, Choong Ki; Hahm, Chang Kok [Hanyang University College of Medicine, Seoul (Korea, Republic of)

    2002-09-01

    To determine which CT findings are useful for the early disgnosis of esophageal perforation, and on the basis of these findings, to assess the accuracy of prediction of the perforation site. A review of medical records indicated that between January 1995 and December 2001, 36 patients with esophageal perforation were admitted to our hospital. Thirteen of these [M:F=8:5, age; 28-69 (mean, 52.4) years], who had undergone CT chest scanning, were included in this study. The causes of esophageal perforation were trauma (n=5), infectious diseases (n=4), Boerhaave syndrome (n=1), lung cancer (n=1), esophageal cancer (n=1), and idiopathic. Two chest radiologists unaware of the clinical findings reviewed the CT scans and predicted whether the upper or lower esophagus was perforated. The most common CT finding was extraluminal air at the posterior mediastinum (n=11), while other findings included pulmonary consolidation (n=10), pleural effusion (n=7), discontinuity of the esophageal wall (n=6) and subcutaneous emphysema (n=4), fluid collection around the esophagus (n-4), esophageal wall thickening (n=4), pneumothorax (n=2), and lung abscess (n=2). The perforation site was accurately predicted in 76.9% of cases (10/13). The CT findings which help the diagnosis of esophageal perforation, and prediction of the sites at which it occurs, are extraluminal air of fluid collection, focal defect of the esophageal wall, and esophageal wall thickening.

  3. CT findings of exophageal perforation

    International Nuclear Information System (INIS)

    Heo, Jeong Nam; Choi, Yo Won; Jeon, Seok Chol; Park, Choong Ki; Hahm, Chang Kok

    2002-01-01

    To determine which CT findings are useful for the early disgnosis of esophageal perforation, and on the basis of these findings, to assess the accuracy of prediction of the perforation site. A review of medical records indicated that between January 1995 and December 2001, 36 patients with esophageal perforation were admitted to our hospital. Thirteen of these [M:F=8:5, age; 28-69 (mean, 52.4) years], who had undergone CT chest scanning, were included in this study. The causes of esophageal perforation were trauma (n=5), infectious diseases (n=4), Boerhaave syndrome (n=1), lung cancer (n=1), esophageal cancer (n=1), and idiopathic. Two chest radiologists unaware of the clinical findings reviewed the CT scans and predicted whether the upper or lower esophagus was perforated. The most common CT finding was extraluminal air at the posterior mediastinum (n=11), while other findings included pulmonary consolidation (n=10), pleural effusion (n=7), discontinuity of the esophageal wall (n=6) and subcutaneous emphysema (n=4), fluid collection around the esophagus (n-4), esophageal wall thickening (n=4), pneumothorax (n=2), and lung abscess (n=2). The perforation site was accurately predicted in 76.9% of cases (10/13). The CT findings which help the diagnosis of esophageal perforation, and prediction of the sites at which it occurs, are extraluminal air of fluid collection, focal defect of the esophageal wall, and esophageal wall thickening

  4. Current management of peptic ulcer perforations

    International Nuclear Information System (INIS)

    Menakuru, S.R.

    2004-01-01

    Perforation is a life-threatening complication of peptic ulcer disease. Smoking and use of non-steroidal anti-inflammatory drugs are important risk factors for perforation. Diagnosis is made clinically and confirmed by the presence of pneumoperitoneum on radiographs. Nonoperative management is successful in patients identified to have a spontaneously sealed perforation proven by water-soluble contrast gastroduodenogram. Operative management consists of the time-honoured practice of mental patch closure, but now this can be done by laparoscopic methods. The practice of addition of acid-reducing procedures is currently being debated though it continues to be recommended in good-risk patients. Laparoscopic approaches to closure of duodenal perforation are now being applied widely and may become the gold standard in the future especially in patients with < 10 mm perforation size presenting within the first 24 hours of onset of pain. The role of Helicobacter pylori in duodenal ulcer perforation is controversial and more studies are needed to answer this question though recent indirect evidence suggests that eradicating H pylori may reduce the necessity for adding acid reducing procedures and the associated morbidity. Perforation is a life-threatening complication of peptic ulcer disease. The management of peptic ulcer disease has evolved over the decades, due to advances in operative techniques, bacteriology and pharmacology. While the recognition of the role of Helicobacter pylori (H. pylori) in peptic ulceration has resulted in a paradigm shift in the management of uncomplicated peptic ulcers, debate continues about the appropriate management of perforated duodenal bulb and prepyloric ulcers. A new dimension has been added to this controversy by the advent of laparoscopic techniques for closing the perforation. A Medline search of all articles dealing with the management of peptic ulcer perforation published after 1985 was undertaken. The short listed articles were

  5. Glove Perforations During Interventional Radiological Procedures

    International Nuclear Information System (INIS)

    Leena, R. V.; Shyamkumar, N. K.

    2010-01-01

    Intact surgical gloves are essential to avoid contact with blood and other body fluids. The objective of this study was to estimate the incidence of glove perforations during interventional radiological procedures. In this study, a total of 758 gloves used in 94 interventional radiological procedures were examined for perforations. Eleven perforations were encountered, only one of which was of occult type. No significant difference in the frequency of glove perforation was found between the categories with varying time duration.

  6. Helicobacter pylori in gastroduodenal perforation

    Directory of Open Access Journals (Sweden)

    Bharat B Dogra

    2014-01-01

    Full Text Available Background:peptic ulcers were earlier believed to be caused by dietary factors, gastric acid, and stress. However, in 1983, Warren and Marshall identified the correlation between Helicobacter pylori (H. pylori and peptic ulcers. It is now well established that most of the peptic ulcers occur as a result of H. pylori infection. But the co-relation between perforated peptic ulcer and H. pylori infection is not yet fully established. Aims and objectives : to study the prevalence of H. pylori infection in patients with perforated peptic ulcer. Materials and methods: this was a prospective study carried out in all cases of perforated peptic ulcer reporting in surgical wards of a medical college during 2008-2010. A total of 50 cases, presenting as acute perforation of duodenum and stomach during this period, formed the study group. After resuscitation, all the cases were subjected to emergency exploratory laparotomy. The exact site of perforation was identified, biopsy was taken from the ulcer margin from 2-3 sites and the tissue was sent for H. pylori culture and histopathological examination. Simple closure of perforation, omentoplasty, thorough peritoneal lavage and drainage was carried out. Results: out of the 50 cases of perforated peptic ulcer, 38 happened to be males, and only 12 were females. The age of the patients ranged from 20 to 70 years. All the patients underwent only emergency laparotomy. As many as 46 cases (92% turned out to be positive for H. pylori and only four cases (8% were negative for this infection. Postoperatively, patients who were found to be positive for H. pylori were put on anti-H. pylori treatment. Conclusion: there was a high prevalence of H. pylori infection in patients with perforated gastroduodenal ulcers.

  7. Spectrum of perforation peritonitis in delhi: 77 cases experience.

    Science.gov (United States)

    Yadav, Dinesh; Garg, Puneet K

    2013-04-01

    Perforation peritonitis is the most common surgical emergency encountered by surgeons all over the world as well in India. The spectrum of etiology of perforation peritonitis in tropical countries continues to differ from its western counterpart. This study was conducted at Hindu Rao Hospital, Municipal Corporation of Delhi, New Delhi, India, designed to highlight the spectrum of perforation peritonitis in the eastern countries and to improve its outcome. This prospective study included 77 consecutive patients of perforation peritonitis studied in terms of clinical presentations, causes, site of perforation, surgical treatment, postoperative complications, and mortality at Hindu Rao Hospital, Delhi, from March 1, 2011 to December 1, 2011, over a period of 8 months. All patients were resuscitated and underwent emergency exploratory laparotomy. On laparotomy cause of perforation peritonitis was found and controlled. The most common cause of perforation peritonitis noticed in our series was perforated duodenal ulcer (26.4 %) and ileal typhoid perforation (26.4 %), each followed by small bowel tuberculosis (10.3 %) and stomach perforation (9.2 %), perforation due to acute appendicitis (5 %). The highest number of perforations was seen in ileum (39.1 %), duodenum (26.4 %), stomach (11.5 %), appendix (3.5 %), jejunum (4.6 %), and colon (3.5 %). Overall mortality was 13 %. The spectrum of perforation peritonitis in India continuously differs from western countries. The highest number of perforations was noticed in the upper part of the gastrointestinal tract as compared to the western countries where the perforations seen mostly in the distal part. The most common cause of perforation peritonitis was perforated duodenal ulcer and small bowel typhoid perforation followed by typhoid perforation. Large bowel perforations and malignant perforations were least common in our setup.

  8. Efficacy of transgene expression in porcine skin as a function of electrode choice

    DEFF Research Database (Denmark)

    Gothelf, A; Mahmood, Faisal; Dagnaes-Hansen, Frederik

    2011-01-01

    , have mainly been performed in rodents and the body of evidence on electrode choice and optimal pulsing conditions is limited. We therefore tested plate and needle electrodes in vivo in porcine skin, which resembles human skin in structure. The luciferase (pCMV-Luc) gene was injected intradermally...... and subsequently electroporated. Simultaneously, studies with gene electrotransfer to porcine skin using plasmids coding for green fluorescent protein (GFP) and betagalactosidase were performed. Interestingly, we found needle electrodes to be more efficient than plate electrodes (p...

  9. Modeling the hydrodynamics of phloem sieve plates

    Directory of Open Access Journals (Sweden)

    Kaare Hartvig Jensen

    2012-07-01

    Full Text Available Sieve plates have an enormous impact on the efficiency of the phloem vascular system of plants, responsible for the distribution of photosynthetic products. These thin plates, which separate neighboring phloem cells, are perforated by a large number of tiny sieve pores and are believed to play a crucial role in protecting the phloem sap from intruding animals by blocking flow when the phloem cell is damaged. The resistance to the flow of viscous sap in the phloem vascular system is strongly affected by the presence of the sieve plates, but the hydrodynamics of the flow through them remains poorly understood. We propose a theoretical model for quantifying the effect of sieve plates on the phloem in the plant, thus unifying and improving previous work in the field. Numerical simulations of the flow in real and idealized phloem channels verify our model, and anatomical data from 19 plant species are investigated. We find that the sieve plate resistance is correlated to the cell lumen resistance, and that the sieve plate and the lumen contribute almost equally to the total hydraulic resistance of the phloem translocation pathway.

  10. Fundamental study on metal plating removal using pulsed power technology

    International Nuclear Information System (INIS)

    Imasaka, Kiminobu; Gnapowski, Sebastian; Akiyama, Hidenori

    2013-01-01

    A novel method for the metal removal from metal-plated substrate using pulsed power technology is proposed. A metal-plated substrate with three metal-layers structure (Cu, Ni and Au) is used as the sample substrate. Repetitive pulsed arc discharge plasma is generated between a rod electrode and the surface of substrate. Effect of the type of electrode system on metal plating removal was investigated. The removal region is produced by the moving phenomena of the pulsed arc discharge. A part of Au layer, which is the tompost metal surface of the substrate is vaporized and removed by the repetitive pulsed arc discharges. The proposed method can be used for recycle of metal-plated substrate. (author)

  11. The management of large perforations of duodenal ulcers

    Directory of Open Access Journals (Sweden)

    Sharma Rajeev

    2005-06-01

    Full Text Available Abstract Background Duodenal ulcer perforations are a common surgical emergency, but literature is silent on the exact definition, incidence, management and complications of large perforations of duodenal ulcers. Methods The case files of 162 patients who underwent emergency laparotomy for duodenal ulcer perforations over a period of three years (2001 – 2003 were retrospectively reviewed and sorted into groups based on the size of the perforations – one group was defined as 'small 'perforations (less than 1 cm in diameter, another 'large' (when the perforation was more than 1 cm but less than 3 cms, and the third, 'giant'(when the perforation exceeded 3 cm. These groups of patients were then compared with each other in regard to the patient particulars, duration of symptoms, surgery performed and the outcome. Results A total of 40 patients were identified to have duodenal ulcer perforations more than 1 cm in size, thus accounting for nearly 25 % of all duodenal ulcer perforations operated during this period. These patients had a significantly higher incidence of leak, morbidity and mortality when compared to those with smaller perforations. Conclusion There are three distinct types of perforations of duodenal ulcers that are encountered in clinical practice. The first, are the 'small' perforations that are easy to manage and have low morbidity and mortality. The second are the 'large' perforations, that are also not uncommon, and omental patch closure gives the best results even in this subset of patients. The word 'giant' should be reserved for perforations that exceed 3 cms in diameter, and these are extremely uncommon.

  12. A novel high-performance counter electrode for dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Wang Guiqiang; Lin Ruifeng; Lin Yuan; Li Xueping; Zhou Xiaowen; Xiao Xurui

    2005-01-01

    A novel Pt counter electrode for dye-sensitized solar cells (DSC) was prepared by thermal decomposition of H 2 PtCl 6 on NiP-plated glass substrate. The charge-transfer kinetic properties of the platinized NiP-plated glass electrode (Pt/NiP electrode) for triiodide reduction were studied by electrochemical impedance spectroscopy. Pt/NiP electrode has the advantage over the platinized FTO conducting glass electrode (Pt/FTO electrode) in increasing the light reflectance and reducing the sheet resistance leading to improve the light harvest efficiency and the fill factor of the dye-sensitized solar cells effectively. The photon-to-current efficiency and the overall conversion efficiency of DSC using Pt/NiP counter electrode is increased by 20% and 33%, respectively, compared to that of using Pt/FTO counter electrode. Examination of the anodic dissolution and the long-term test on the variation of charge-transfer resistance indicates the good stability of the Pt/NiP electrode in the electrolyte containing iodide/triiodide

  13. Laparoscopic pyloroplasty for perforated peptic ulcer.

    Science.gov (United States)

    Grišin, Edvard; Mikalauskas, Saulius; Poškus, Tomas; Jotautas, Valdemaras; Strupas, Kęstutis

    2017-09-01

    Peptic ulcer is a common disease affecting millions of people every year. Despite improved understanding and treatment of the disease, the number of patients admitted with duodenal peptic ulcer perforation has not decreased. Deaths from peptic ulcer disease overcome other common emergency situations. Laparoscopic repair of the perforated peptic ulcer (PPU) is the gold standard approach for simple perforation. However, in patients with large perforated chronic ulcers laparotomy with pyloroplasty is the standard treatment. It is generally accepted to perform open surgery in PPU emergencies because of the greater knowledge and experience gathered over the past decades and less potential harm for the patient or surgical complications. We present a case of successful laparoscopic pyloroplasty of a perforated duodenal ulcer with stenosis.

  14. High-performance free-standing capacitor electrodes of multilayered Co9S8 plates wrapped by carbonized poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)/reduced graphene oxide

    Science.gov (United States)

    Yao, Tinghui; Li, Yali; Liu, Dequan; Gu, Yipeng; Qin, Shengchun; Guo, Xin; Guo, Hui; Ding, Yongqiang; Liu, Qiming; Chen, Qiang; Li, Junshuai; He, Deyan

    2018-03-01

    In this paper, a free-standing electrode structure composed of multilayered Co9S8 plates wrapped by carbonized poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)/reduced graphene oxide (PEDOT:PSS/rGO) layers is introduced. Excellent supercapacitive behaviors, especially long cycling stability at high current densities are delivered owing to the synergetic effects of stable electrical contact between the active material and carbonized PEDOT:PSS/rGO due to the wrapped configuration, efficient charge exchange between the multilayered Co9S8 plates and electrolyte, improved electrical conductance by rGO, and plenty of voids for accommodating volume changes. For the optimized electrode (starting materials: 0.5 mL PEDOT:PSS, 1.0 mL GO (6.0 mg mL-1) and 10.0 mg Co(OH)2), a specific capacitance of about 788.9 F g-1 at 1.0 A g-1 and good cycling stability of over 100% of the initial capacitance (∼488.6 F g-1) after 10000 cycles at a current density of 15.0 A g-1 can be achieved. The assembled asymmetric supercapacitor based on the optimized electrode//active carbon exhibits an energy density of ∼19.6 Wh kg-1 at a power density of 400.9 W kg-1.

  15. Separation of Cadmium in Printing Industrial Liquid Waste by Electromagnetic Plating System

    International Nuclear Information System (INIS)

    Prayitno

    2007-01-01

    To prevent incidence of environmental contamination and its effect to society health and other mortal, poisonous and dangerous substance waste have to be managed peculiarly by minimizing or eliminating the nature of its danger. Various processing have been developed to degrade the waste rate for example sorption, flotation, flocculation, etc., but the yield of the degradation of metal rate can not fulfill permanent standard quality of liquid waste. Because of the reason explained before, its important to make a new breakthrough as one of final phase processing alternative named reductant electromagnetic plating. Waste to be degraded in this research is cadmium. In fact cadmium represent the foregain metal for human and is not require at all in human body for metabolism process. Though plenty of cadmium exploited, but during for centuries it caused the food poisoned because this metal insoluble in organic acid. Separation of cadmium rate with electromagnetic plating influenced by time process, concentration, current strength, and type of electrode plate. Result of research indicate that the optimum time processing if using plate of copper electrode is during 30 minute and using plate of aluminium electrode is during 20 minute. Optimum of strong current that used in process of electromagnetic plating is only 0.8 Ampere and concentration effective is 5 mg / L. The most effective type of electrode plate for reducing cadmium from waste by using electromagnetic plating is aluminium. Appliance of electromagnetic plating system is very compatible used for the reduction of cadmium and others metal for feed concentration (1 - 5) mg/L .at the price efficiency of reduction is (95 - 98) %, standard quality of liquid waste is (0.05 - 1) mg/L. (author)

  16. CLINICAL STUDY OF DUODENAL PERFORATION

    Directory of Open Access Journals (Sweden)

    Sambasiva Rao

    2016-04-01

    Full Text Available BACKGROUND The duodenal injury can pose a formidable challenge to the surgeon and failure to manage it properly may have devastating results. Over the centuries, there was little to offer the patient of acute abdomen beyond cupping, purgation and enemas, all of which did more harm than good. It was not until 1884 that Mikulicz made an attempt to repair a perforation. Recent statistics indicate roughly 10% of population develop gastric or duodenal ulcer in life time. Roughly 1-3% of population above the age of 20 years have some degree of peptic ulcer activity during any annual period. A detailed history with regards to the signs and symptoms of the patient, a meticulous examination, radiological and biochemical investigations help to arrive at a correct preoperative diagnosis. In this study, a sincere effort has been put to understand the demographic patterns, to understand the underlying aetiology and to understand the effectiveness of the standard methods of investigation and treatment in use today. METHODS This is a 24 months prospective study i.e., from September 2011 to September 2013 carried out at Dr. Pinnamaneni Siddhartha Institute of Medical Sciences & Research Foundation. The study included the patients presenting to Dr. Pinnamaneni Siddhartha Institute of Medical Sciences & Research Foundation to emergency ward with signs and symptoms of hollow viscus perforation. The sample size included 30 cases of duodenal perforation. RESULTS Duodenal ulcer perforation commonly occurs in the age group of 30-60 years, but it can occur in any age group. Majority of the patients were male. Smoking and alcohol consumption were risk factors in most cases (53.3% for the causation of duodenal ulcer perforation. Sudden onset of abdominal pain, situated at epigastrium and right hypochondrium was a constant symptom (100%. Vomiting, constipation and fever were not so common. CONCLUSION The emergency surgical management for perforated duodenal ulcer is by

  17. Reviewing metallic PEMFC bipolar plates

    Energy Technology Data Exchange (ETDEWEB)

    Wang, H.; Turner, J.A. [National Renewable Energy Laboratory, Golden, CO (United States)

    2010-08-15

    A bipolar plate is one of the most important components in a polymer exchange membrane fuel cell (PEMFC) stack and has multiple functions. Metallic bipolar plate candidates have advantages over composite rivals in excellent electrical and thermal conductivity, good mechanical strength, high chemical stability, very wide alloy choices, low cost and, most importantly, existing pathways for high-volume, high-speed mass production. The challenges with metallic bipolar plates are the higher contact resistance and possible corrosion products, which may contaminate the membrane electrode assembly. This review evaluates the candidate metallic and coating materials for bipolar plates and gives the perspective of the research trends. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  18. A perforated diverticulum in Cushing's disease

    OpenAIRE

    de Havenon, Adam; Ehrenkranz, Joel

    2011-01-01

    We report a case of perforated colonic diverticulum in Cushing's disease. Although perforated diverticuli have been described in patients with Cushing's syndrome secondary to exogenous glucocorticoids, this complication has not been described in patients with Cushing's disease. Patients with hypercortisolism, from either exogenous or endogenous sources, should be monitored for diverticular perforation.

  19. CLINICAL STUDY AND MANAGEMENT OF BENIGN GASTROINTESTINAL PERFORATIONS

    Directory of Open Access Journals (Sweden)

    Kishan

    2016-05-01

    Full Text Available INTRODUCTION Peritonitis due to gastrointestinal perforation is one of the commonest surgical emergencies encountered by a general surgeon. (1,2 Mortality and morbidity is still very high despite early diagnosis and intensive management. This study is aimed to find common causes of perforations, its presentations, mode of investigations and treatment done and outcome of patients. METHODS Case records of all patients, in exclusion and inclusion criteria, who were admitted in emergency surgical ward with suspected GI perforation and peritonitis were included in study and diagnosis confirmed by either investigations preoperatively or by laparotomy and results analysed over a period of 16 months. RESULTS GI perforations due to benign causes are most common causes of peritonitis, of which gastroduodenal perforations are commonest followed by appendicular perforation closely followed by infective perforations. CONCLUSION Benign causes of upper gastroduodenal perforations are common causes of peritonitis (2,3. Mortality increases with delay in presentation and treatment. Abdominal signs like guarding rigidity are present in majority of cases. X-ray erect abdomen was effective in detecting perforation in majority of cases. Surgery is the treatment in all cases of perforation.

  20. Ultraconformable Temporary Tattoo Electrodes for Electrophysiology

    Science.gov (United States)

    Ferrari, Laura M.; Sudha, Sudha; Tarantino, Sergio; Esposti, Roberto; Bolzoni, Francesco; Cavallari, Paolo; Cipriani, Christian

    2018-01-01

    Abstract Electrically interfacing the skin for monitoring personal health condition is the basis of skin‐contact electrophysiology. In the clinical practice the use of stiff and bulky pregelled or dry electrodes, in contrast to the soft body tissues, imposes severe restrictions to user comfort and mobility while limiting clinical applications. Here, in this work dry, unperceivable temporary tattoo electrodes are presented. Customized single or multielectrode arrays are readily fabricated by inkjet printing of conducting polymer onto commercial decal transfer paper, which allows for easy transfer on the user's skin. Conformal adhesion to the skin is provided thanks to their ultralow thickness (Tattoo electrode–skin contact impedance is characterized on short‐ (1 h) and long‐term (48 h) and compared with standard pregelled and dry electrodes. The viability in electrophysiology is validated by surface electromyography and electrocardiography recordings on various locations on limbs and face. A novel concept of tattoo as perforable skin‐contact electrode, through which hairs can grow, is demonstrated, thus permitting to envision very long‐term recordings on areas with high hair density. The proposed materials and patterning strategy make this technology amenable for large‐scale production of low‐cost sensing devices. PMID:29593975

  1. Perforated peptic ulcer

    DEFF Research Database (Denmark)

    Søreide, Kjetil; Thorsen, Kenneth; Harrison, Ewen M

    2015-01-01

    Perforated peptic ulcer is a common emergency condition worldwide, with associated mortality rates of up to 30%. A scarcity of high-quality studies about the condition limits the knowledge base for clinical decision making, but a few published randomised trials are available. Although Helicobacter...... need further assessment. Adequate trials with low risk of bias are urgently needed to provide better evidence. We summarise the evidence for perforated peptic ulcer management and identify directions for future clinical research....

  2. AC electrical breakdown phenomena of epoxy/layered silicate nanocomposite in needle-plate electrodes.

    Science.gov (United States)

    Park, Jae-Jun; Lee, Jae-Young

    2013-05-01

    Epoxy/layered silicate nanocomposite for the insulation of heavy electric equipments were prepared by dispersing 1 wt% of a layered silicate into an epoxy matrix with a homogenizing mixer and then AC electrical treeing and breakdown tests were carried out. Wide-angle X-ray diffraction (WAXD) analysis and transmission electron microscopy (TEM) observation showed that nano-sized monolayers were exfoliated from a multilayered silicate in the epoxy matrix. When the nano-sized silicate layers were incorporated into the epoxy matrix, the breakdown rate in needle-plate electrode geometry was 10.6 times lowered than that of the neat epoxy resin under the applied electrical field of 520.9 kV/mm at 30 degrees C, and electrical tree propagated with much more branches in the epoxy/layered silicate nanocomposite. These results showed that well-dispersed nano-sized silicate layers retarded the electrical tree growth rate. The effects of applied voltage and ambient temperature on the tree initiation, growth, and breakdown rate were also studied, and it was found that the breakdown rate was largely increased, as the applied voltage and ambient temperature increased.

  3. Efficacy of transgene expression in porcine skin as a function of electrode choice

    DEFF Research Database (Denmark)

    Gotholf, Anita; Mahmood, Faisad; Dagnæs-Hansen, Frederik

    2011-01-01

    , have mainly been performed in rodents and the body of evidence on electrode choice and optimal pulsing conditions is limited. We therefore tested plate and needle electrodes in vivo in porcine skin, which resembles human skin in structure. The luciferase (pCMV-Luc) gene was injected intradermally...... and subsequently electroporated. Simultaneously, studies with gene electrotransfer to porcine skin using plasmids coding for green fluorescent protein (GFP) and betagalactosidase were performed. Interestingly, we found needle electrodes to be more efficient than plate electrodes (p..., our data support that needle electrodes should be used in human clinical studies of gene electrotransfer to skin for improved expression....

  4. On the ''memory'' effect and its relation to the mechanism of formation of mercury-graphite electrode in inversion voltammetry

    International Nuclear Information System (INIS)

    Nejman, E.Ya.; Petrova, L.G.; Dolgopolova, G.M.; Ignatov, V.I.

    1977-01-01

    Simultaneous discharge ionization of lead-copper and cadmium-copper systems on the surface of mercury-plated graphite and graphite electrodes has been studied. A model is suggested of the preparation process of a mercury-plated graphite electrode obtained in simultaneous electroposition of mercury and elements determined as microimpurities. Processes, which occur on the electrode during relaxation time between electrolysis beginning and formation of the mercury phase, may be probable reasons for mutual effects of elements of the mercury-plated graphite electrode

  5. Multiple, Pan-Enteric Perforation Secondary to Intestinal Tuberculosis

    Science.gov (United States)

    Masood, Irfan; Majid, Zain; Rafiq, Ali; Rind, Waqas; Zia, Aisha; Raza, Sajjad

    2015-01-01

    Free perforation is one of the most feared complications of the intestinal tuberculosis. The terminal ileum is the most common site of perforation, while the majority of (90%) perforations are solitary. Herein, we describe a case of a 25-year-old male who presented with generalized peritonitis requiring an emergency exploratory laparotomy, which revealed pan-enteric perforation characterized by multiple perforations of the small bowel extending 10–15 cm from the DJ flexure up to the terminal ileum. The perforations were primarily closed, while 6–8 cm of the diseased terminal ileum was resected and the two ends were brought out as double-barreled ostomy. To the best of our knowledge, such an extensive tuberculous perforation of the small bowel has not been previously reported in the literature before. PMID:26798540

  6. HVDC Ground Electrodes and Tectonic Setting

    Science.gov (United States)

    Freire, P. F.; Pereira, S. Y.

    2017-12-01

    Ground electrodes in HVDC transmission are huge grounding systems for the DC part of the converter substation, about 1 km wide, sized to inject in the ground DC currents up to 3.5 kA. This work presents an analysis of how the tectonic setting at converter substation location is determinant for the search of the best electrode location (Site Selection) and on its design and performance. It will briefly present the author experience on HVDC electrode design, summarized as follows: Itaipu - Foz do Iguaçu electrodes (transmitter side) located in the middle of Paraná Sedimentary Basin, and Ibiúna electrodes (receiving side) on the border of the basin, 6 km from the geological strike, where the crystalline basement outcrops in São Paulo state; Madeira River - North electrodes (transmitting side) located on the Northwest border of South Amazon Craton, where the crystalline basement is below a shallow sediments layer, and South electrodes (receiving side) located within Paraná Sedimentary Basin; Chile - electrodes located on the Andean forearc, where the Nazca Plate plunges under the South American Plate; Kenya - Ethiopia - electrodes located in the African Rift; Belo Monte - North electrodes (transmitter side) located within the Amazonian Sedimentary Basin, about 35 km of its South border, and South electrodes (receiving side) within Paraná Sedimentary Basin (bipole 1) and on crystalline metamorphic terrain "Brasília Belt" (bipole 2). This diversity of geological conditions results on ground electrodes of different topologies and dimensions, with quite different electrical and thermal performances. A brief study of the geology of the converter stations regions, the so-called Desktop Study, allows for the preview of several important parameters for the site selection and design of the electrodes, such as localization, type, size and estimate of the interference area, which are important predictors of the investment to be made and indications of the design to be

  7. Welding procedure specification for arc welding of St 52-3N steel plates with covered electrodes

    International Nuclear Information System (INIS)

    Cvetkovski, S.; Slavkov, D.; Magdeski, J.

    2003-01-01

    In this paper the results of approval welding technology for arc welding of plates made of St 52-3N steel are presented. Metal arc welding with covered electrode is used welding process. Test specimens are butt welded in different welding positions P A , P F , P C and P D . Before start welding preliminary welding procedure was prepared. After welding of test specimens non destructive and destructive testing was performed. Obtained results were compared with standard DIN 17100 which concerns to chemical composition and mechanical properties of base material. It was confirmed that in all cases mechanical properties of welded joint are higher than those of base material, so preliminary welding procedure (pWTS) can be accepted as welding procedure specification WPS for metal arc welding of St52-3N steel. (Original)

  8. Mortality risk factor analysis in colonic perforation: would retroperitoneal contamination increase mortality in colonic perforation?

    Science.gov (United States)

    Yoo, Ri Na; Kye, Bong-Hyeon; Kim, Gun; Kim, Hyung Jin; Cho, Hyeon-Min

    2017-10-01

    Colonic perforation is a lethal condition presenting high morbidity and mortality in spite of urgent surgical treatment. This study investigated the surgical outcome of patients with colonic perforation associated with retroperitoneal contamination. Retrospective analysis was performed for 30 patients diagnosed with colonic perforation caused by either inflammation or ischemia who underwent urgent surgical treatment in our facility from January 2005 to December 2014. Patient characteristics were analyzed to find risk factors correlated with increased postoperative mortality. Using the Physiological and Operative Severity Score for the Enumeration of Mortality and Morbidity (POSSUM) audit system, the mortality and morbidity rates were estimated to verify the surgical outcomes. Patients with retroperitoneal contamination, defined by the presence of retroperitoneal air in the preoperative abdominopelvic CT, were compared to those without retroperitoneal contamination. Eight out of 30 patients (26.7%) with colonic perforation had died after urgent surgical treatment. Factors associated with mortality included age, American Society of Anesthesiologists (ASA) physical status classification, and the ischemic cause of colonic perforation. Three out of 6 patients (50%) who presented retroperitoneal contamination were deceased. Although the patients with retroperitoneal contamination did not show significant increase in the mortality rate, they showed significantly higher ASA physical status classification than those without retroperitoneal contamination. The mortality rate predicted from Portsmouth POSSUM was higher in the patients with retroperitoneal contamination. Patients presenting colonic perforation along with retroperitoneal contamination demonstrated severe comorbidity. However, retroperitoneal contamination was not found to be correlated with the mortality rate.

  9. Multiple, Pan-Enteric Perforation Secondary to Intestinal Tuberculosis

    Directory of Open Access Journals (Sweden)

    Irfan Masood

    2015-01-01

    Full Text Available Free perforation is one of the most feared complications of the intestinal tuberculosis. The terminal ileum is the most common site of perforation, while the majority of (90% perforations are solitary. Herein, we describe a case of a 25-year-old male who presented with generalized peritonitis requiring an emergency exploratory laparotomy, which revealed pan-enteric perforation characterized by multiple perforations of the small bowel extending 10–15 cm from the DJ flexure up to the terminal ileum. The perforations were primarily closed, while 6–8 cm of the diseased terminal ileum was resected and the two ends were brought out as double-barreled ostomy. To the best of our knowledge, such an extensive tuberculous perforation of the small bowel has not been previously reported in the literature before.

  10. STUDY OF CLINICAL OUTCOMES OF SUBFASCIAL PERFORATOR LIGATION SURGERY IN PERFORATOR INCOMPETENCE

    Directory of Open Access Journals (Sweden)

    Vasuki Rajam

    2017-02-01

    Full Text Available BACKGROUND Chronic venous insufficiency presents with a spectrum of clinical features ranging from pain or heaviness of affected limbs to non-healing ulcers over the lower limbs and usually require some form of surgical intervention, performing direct perforator vein division preferably by subfascial endoscopic perforator ligation surgery for perforator incompetence, as despite aggressive conservative therapy including compression, lifestyle modification and venotonic medications which are of high cost treatment with increased risk of increasing symptoms. MATERIALS AND METHODS A prospective longitudinal clinical study of 30 patients selected by systematic sampling method from November 2014 to September 2015 at our institution was conducted to determine the results of subfascial endoscopic perforator vein surgery (SEPS in perforator incompetence. RESULTS For venous clinical severity scoring pre operatively and after 3 weeks post-surgery, the mean for VCSS pre-operatively was 6.66 and a standard deviation of 2.399. The T value was calculated and was found to be 4.9321 and p value of 0.00001(p value less than 0.05 is significant. Similarly for the cases with active ulcer, the size assessment pre-operatively and post-SEPS was again analysed using student t test and the mean ulcer size prior to surgery was found to be 3.3 and standard deviation of 1.984. The T value was calculated and was found to be 1.789009 and a p value of 0.04 (p value less than 0.05 is significant. CONCLUSION Our study concluded that favourable and significant ulcer healing rate with improvement and reduction in clinical severity suggests that SEPS plays an important role in surgical management of advanced stages of venous insufficiency.

  11. Tricholithobezoar Causing Gastric Perforation

    Directory of Open Access Journals (Sweden)

    Juliana Santos Valenciano

    2012-01-01

    Full Text Available A bezoar is an intraluminal mass formed by the accumulation of undigested material in the gastrointestinal tract. Trichobezoar is a rare condition seen almost exclusively in young women with trichotillomania and trichotillophagia. When not recognized, the trichobezoar continues to grow, which increases the risk of severe complications such as gastric ulceration and even perforation. Formation of a gallstone within the trichobezoar (tricholithobezoar is an event that has not yet been described. We report the case of a 22-year-old woman admitted to the emergency room with signals and symptoms of an epigastric mass and perforative acute abdomen. Radiological study revealed bilateral pneumoperitoneum. Personal history revealed depressive syndrome, trichotillomania and trichophagia. With a diagnosis of visceral perforation, an urgent exploratory laparotomy was performed. This confirmed the diagnosis of gastric perforation due to a large trichobezoar with the formation of a gastrolith that was removed by anterior gastrotomy. Biochemical study of the gastric stone revealed that it was composed of bile salts. There were no complications. The patient was discharged on the 5th postoperative day and was referred for psychiatric treatment.

  12. Clinical applications of the superior epigastric artery perforator (SEAP) flap: anatomical studies and preoperative perforator mapping with multidetector CT.

    Science.gov (United States)

    Hamdi, Moustapha; Van Landuyt, Koenraad; Ulens, Sara; Van Hedent, Eddy; Roche, Nathalie; Monstrey, Stan

    2009-09-01

    Pedicled superior epigastric artery perforator (SEAP) flaps can be raised to cover challenging thoracic defects. We present an anatomical study based on multidetector computerized tomography (MDCT) scan findings of the SEA perforators in addition to the first reported clinical series of SEAP flaps in anterior chest wall reconstruction. (a) In the CT scan study, images of a group of 20 patients who underwent MDCT scan analysis were used to visualise bilaterally the location of musculocutaneous SEAP. X- and Y-axes were used as landmarks to localise the perforators. The X-axis is a horizontal line at the junction of sternum and xyphoid (JCX) and the Y-axis is at the midline. (b) In the clinical study, seven pedicled SEAP flaps were performed in another group of patients. MDCT images revealed totally 157 perforators with a mean of 7.85 perforators per patient. The dominant perforators (137 perforators) were mainly localised in an area between 1.5 and 6.5 cm from the X-axis on both sides and between 3 and 16 cm below the Y-axis. The calibre of these dominant perforators was judged as 'good' to 'very good' in 82.5% of the cases. The average dimension of the flap was 21.7x6.7 cm. All flaps were based on one perforator. Mean harvesting time was 110 min. There were no flap losses. Minor tip necrosis occurred in two flaps. One of them was treated with excision and primary closure. Our clinical experience indicates that the SEAP flap provides a novel and useful approach for reconstruction of anterior chest wall defects. CT-based imaging allows for anatomical assessment of the perforators of the superior epigastric artery (SEA).

  13. Research on the Perforating Algorithm Based on STL Files

    Science.gov (United States)

    Yuchuan, Han; Xianfeng, Zhu; Yunrui, Bai; Zhiwen, Wu

    2018-04-01

    In the process of making medical personalized external fixation brace, the 3D data file should be perforated to increase the air permeability and reduce the weight. In this paper, a perforating algorithm for 3D STL file is proposed, which can perforate holes, hollow characters and engrave decorative patterns on STL files. The perforating process is composed of three steps. Firstly, make the imaginary space surface intersect with the STL model, and reconstruct triangles at the intersection. Secondly, delete the triangular facets inside the space surface and make a hole on the STL model. Thirdly, triangulate the inner surface of the hole, and thus realize the perforating. Choose the simple space equations such as cylindrical and rectangular prism equations as perforating equations can perforate round holes and rectangular holes. Through the combination of different holes, lettering, perforating decorative patterns and other perforated results can be accomplished. At last, an external fixation brace and an individual pen container were perforated holes using the algorithm, and the expected results were reached, which proved the algorithm is feasible.

  14. Preparation and characterization of PbO2–ZrO2 nanocomposite electrodes

    International Nuclear Information System (INIS)

    Yao Yingwu; Zhao Chunmei; Zhu Jin

    2012-01-01

    PbO 2 –ZrO 2 nanocomposite electrodes were prepared by the anodic codeposition in the lead nitrate plating bath containing ZrO 2 nanoparticles. The influences of the ZrO 2 nanoparticles concentration, current density, temperature and stirring rate of the plating bath on the composition of the nanocomposite electrodes were investigated. The surface morphology and the structure of the nanocomposite electrodes were characterized by scanning electronic microscopy (SEM) and X-ray diffraction (XRD), respectively. The experimental results show that the addition of ZrO 2 nanoparticles in the electrodeposition process of lead dioxide significantly increases the lifetime of nanocomposite electrodes. The PbO 2 –ZrO 2 nanocomposite electrodes have a service life of 141 h which is almost four times longer than that of the pure PbO 2 electrodes. The morphology of PbO 2 –ZrO 2 nanocomposite electrodes is more compact and finer than that of PbO 2 electrodes. The relative surface area of the composite electrodes is approximately 2 times that of the pure PbO 2 electrodes. The structure test shows that the addition of ZrO 2 nanoparticles into the plating bath decreases the grain size of the PbO 2 –ZrO 2 nanocomposite electrodes. The anodic polarization curves show that the oxygen evolution overpotential of PbO 2 –ZrO 2 nanocomposite electrodes is higher than PbO 2 electrodes. The pollutant anodic oxidation experiment show that the PbO 2 –ZrO 2 nanocomposite electrode exhibited the better performance for the degradation of 4-chlorophenol than PbO 2 electrode, the removal ratio of COD reached 96.2%.

  15. Spectrum of perforation peritonitis in Pakistan: 300 cases Eastern experience.

    Science.gov (United States)

    Afridi, Shahida Parveen; Malik, Faiza; Ur-Rahman, Shafiq; Shamim, Shahid; Samo, Khursheed A

    2008-11-08

    Perforation peritonitis is the most common surgical emergency encountered by the surgeons all over the world as well in Pakistan. The spectrum of etiology of perforation peritonitis in tropical countries continues to differ from its western counter part. This study was conducted at Dow University of health sciences and Civil Hospital Karachi (DUHS & CHK) Pakistan, designed to highlight the spectrum of perforation peritonitis in the East and to improve its outcome. A prospective study includes three hundred consecutive patients of perforation peritonitis studied in terms of clinical presentations, Causes, site of perforation, surgical treatment, post operative complications and mortality, at (DUHS&CHK) Pakistan, from 1st September 2005 - 1st March 2008, over a period of two and half years. All patients were resuscitated underwent emergency exploratory laparotomy. On laparotomy cause of perforation peritonitis was found and controlled. The most common cause of perforation peritonitis noticed in our series was acid peptic disease 45%, perforated duodenal ulcer (43.6%) and gastric ulcer 1.3%. followed by small bowel tuberculosis (21%) and typhoid (17%). large bowel perforation due to tuberculosis 5%, malignancy 2.6% and volvulus 0.3%. Perforation due to acute appendicitis (5%). Highest number of perforations has seen in the duodenum 43.6%, ileum37.6%, and colon 8%, appendix 5%, jejunum 3.3%, and stomach 2.3%. Overall mortality was (10.6%). The spectrum of perforation peritonitis in Pakistan continuously differs from western country. Highest number of perforations noticed in the upper part of the gastrointestinal tract as compared to the western countries where the perforations seen mostly in the distal part. Most common cause of perforation peritonitis is perforated duodenal ulcer, followed by small bowel tuberculosis and typhoid perforation. Majority of the large bowel perforations are also tubercular. Malignant perforations are least common in our setup.

  16. Spectrum of perforation peritonitis in Pakistan: 300 cases Eastern experience

    Directory of Open Access Journals (Sweden)

    Ur-Rahman Shafiq

    2008-11-01

    Full Text Available Abstract Background Perforation peritonitis is the most common surgical emergency encountered by the surgeons all over the world as well in Pakistan. The spectrum of etiology of perforation peritonitis in tropical countries continues to differ from its western counter part. This study was conducted at Dow University of health sciences and Civil Hospital Karachi (DUHS & CHK Pakistan, designed to highlight the spectrum of perforation peritonitis in the East and to improve its outcome. Methods A prospective study includes three hundred consecutive patients of perforation peritonitis studied in terms of clinical presentations, Causes, site of perforation, surgical treatment, post operative complications and mortality, at (DUHS&CHK Pakistan, from 1st September 2005 – 1st March 2008, over a period of two and half years. All patients were resuscitated underwent emergency exploratory laparotomy. On laparotomy cause of perforation peritonitis was found and controlled. Results The most common cause of perforation peritonitis noticed in our series was acid peptic disease 45%, perforated duodenal ulcer (43.6% and gastric ulcer 1.3%. followed by small bowel tuberculosis (21% and typhoid (17%. large bowel perforation due to tuberculosis 5%, malignancy 2.6% and volvulus 0.3%. Perforation due to acute appendicitis (5%. Highest number of perforations has seen in the duodenum 43.6%, ileum37.6%, and colon 8%, appendix 5%, jejunum 3.3%, and stomach 2.3%. Overall mortality was (10.6%. Conclusion The spectrum of perforation peritonitis in Pakistan continuously differs from western country. Highest number of perforations noticed in the upper part of the gastrointestinal tract as compared to the western countries where the perforations seen mostly in the distal part. Most common cause of perforation peritonitis is perforated duodenal ulcer, followed by small bowel tuberculosis and typhoid perforation. Majority of the large bowel perforations are also tubercular

  17. Bipolarly stacked electrolyser for energy and space efficient fabrication of supercapacitor electrodes

    Science.gov (United States)

    Liu, Xiaojuan; Wu, Tao; Dai, Zengxin; Tao, Keran; Shi, Yong; Peng, Chuang; Zhou, Xiaohang; Chen, George Z.

    2016-03-01

    Stacked electrolysers with titanium bipolar plates are constructed for electrodeposition of polypyrrole electrodes for supercapacitors. The cathode side of the bipolar Ti plates are pre-coated with activated carbon. In this new design, half electrolysis occurs which significantly lowers the deposition voltage. The deposited electrodes are tested in a symmetrical unit cell supercapacitor and an asymmetrical supercapacitor stack. Both devices show excellent energy storage performances and the capacitance values are very close to the design value, suggesting a very high current efficiency during the electrodeposition. The electrolyser stack offers multi-fold benefits for preparation of conducting polymer electrodes, i.e. low energy consumption, facile control of the electrode capacitance and simultaneous preparation of a number of identical electrodes. Therefore, the stacked bipolar electrolyser is a technology advance that offers an engineering solution for mass production of electrodeposited conducting polymer electrodes for supercapacitors.

  18. Colonic perforation following endoscopic retrograde ...

    African Journals Online (AJOL)

    She developed severe upper abdominal pain after the ... non-surgical management of pancreatitis and associated complications, colonic perforation should be considered in patients who deteriorate ... To our knowledge this is the first case of a secure pre-operative diagnosis of colonic perforation due to to pancreatitis.

  19. Radiologic Study of Meniscus Perforations in the Temporomandibular Joint

    International Nuclear Information System (INIS)

    Kim, Kee Duck; Park, Chang Seo

    1990-01-01

    Thirty-nine patients (forty-four joints) who had been diagnosed as having meniscus perforation of the temporomandibular joint by inferior joint space arthrography and had been treated by surgical procedures were evaluated retrospectively. Information of clinical findings, arthrotomographic findings and surgical findings was collected on a standardized form and evaluated. The results were as follows: 1. On the 34 patients of 38 joints which were surgically confirmed perforation of meniscus or its attachments of the temporomandibular joint, there were 29 females and 5 males (5.8:1). The average age was 36 years (range 17 to 70). 2. The common clinical findings of group that had meniscus displacement without reduction and with perforation were pain on the affected joint and limitation of mouth opening. In the group showing meniscus displacement with reduction and with perforation the common clinical findings were pain and clicking on the affected joint. 3. 32 joints (84.2%) were arthrotomographically anterior meniscus displacement without reduction and with perforation, 6 joints (15.8%) showed anterior meniscus displacement with reduction and with perforation. 4. Joints categorized arthrotomographically as having meniscus displacement without reduction and with perforation were less likely to have full translation of the condyle in comparison with the normal or meniscus displacement with reduction and with perforation groups (p<0.05) 5. The arthrographic findings of 44 joints having meniscus perforation were compared with surgical findings, there were 6 false positive findings of meniscus perforation, the reliability of arthrographic findings of meniscus perforation was a 86.4% correlation with surgical findings. 6. On the site of perforations of 38 joints which were surgically confirmed perforation of meniscus or its attachments, twenty-three of perforations (60.5%) were in location at the junction of the meniscus and posterior attachment, fourteen (36.9%) were

  20. Isolated jejunal perforation following blunt abdominal trauma

    Directory of Open Access Journals (Sweden)

    Ahmet Pergel

    2012-09-01

    Full Text Available Isolated perforation of the jejunum, following blunt abdominaltrauma, is extremely rare. These injuries aredifficult to diagnose because initial clinical signs are frequentlynonspecific and a delay in treatment increasesmortality and morbidity of the patients. Conventional radiogramsare often inadequate for diagnosing this subsetof trauma. For an accurate and timely diagnosis, thepossibility of bowel perforation and the need for repeatedexaminations should be kept in mind. Herein, we presenta 28-year-old man with isolated jejunal perforation followingblunt abdominal trauma.Key words: Blunt abdominal trauma, isolated jejunal perforation,early diagnosis

  1. Perforated peptic ulcer.

    Science.gov (United States)

    Søreide, Kjetil; Thorsen, Kenneth; Harrison, Ewen M; Bingener, Juliane; Møller, Morten H; Ohene-Yeboah, Michael; Søreide, Jon Arne

    2015-09-26

    Perforated peptic ulcer is a common emergency condition worldwide, with associated mortality rates of up to 30%. A scarcity of high-quality studies about the condition limits the knowledge base for clinical decision making, but a few published randomised trials are available. Although Helicobacter pylori and use of non-steroidal anti-inflammatory drugs are common causes, demographic differences in age, sex, perforation location, and underlying causes exist between countries, and mortality rates also vary. Clinical prediction rules are used, but accuracy varies with study population. Early surgery, either by laparoscopic or open repair, and proper sepsis management are essential for good outcome. Selected patients can be managed non-operatively or with novel endoscopic approaches, but validation of such methods in trials is needed. Quality of care, sepsis care bundles, and postoperative monitoring need further assessment. Adequate trials with low risk of bias are urgently needed to provide better evidence. We summarise the evidence for perforated peptic ulcer management and identify directions for future clinical research. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. [Saphenous perforator flap].

    Science.gov (United States)

    Winkel, R; Tajsic, N; Husum, H; Schlageter, M; Hanebuth, G; Hoffmann, R

    2013-04-01

    Replacement of full thickness soft tissue defects in the lower leg and ankle, appropriate to the defect and following the course of blood vessels feeding the skin of a distally hinged fasciocutaneous flap most reliably based on the individual anatomy of distal perforators of the posterior tibial artery. Full thickness soft tissue defects, up to 12 cm in length and up to 8 cm in width. Sufficient vascularization of the foot required, in osteomyelitis, and when joints, fractures, implants and tendons are exposed and when a split skin graft, a local flap, a suralis perforator flap or a free flap is not indicated. For patients, in whom a 1-2 h operation is not possible; necessity of angioplasty; decollement or scars around the distal perforators of the posterior tibial artery; local infection or necrosis of soft tissues and/or bone, which cannot be totally excised. Radical debridement; flap dissection without tourniquet; microdissection; design of the flap on the skin: pivot point ~ 10 cm (6-14 cm) proximal of the tip of the medial malleolus; base ~ 5 cm in width, between the course of the saphenous nerve and of the great saphenous vein and the Achilles tendon; adipofascial pedicle up to 15 cm in length sited over the septum between soleus and flexor digitorum muscles, following the course of the saphenous nerve, with a central skin stripe, which expands into a proximal skin island; skin island is outlined similar to the defect, but larger by 1 to 2 cm, surrounded by an adipofascial border: adjustment of the planning as well as of the elevation of these flaps according to the individual position and the caliber of perforators requires in each case the search for a perforator at the estimated pivot point. Delay of transposition, if the division of more than one perforator proximal to the pivot point obviously diminishes circulation. No "tunnelling "of the pedicle; defects of skin due to the elevation of the flap are replaced by split and meshed skin grafts or temporary

  3. Perforated marginal ulcers after laparoscopic gastric bypass.

    Science.gov (United States)

    Felix, Edward L; Kettelle, John; Mobley, Elijah; Swartz, Daniel

    2008-10-01

    Perforated marginal ulcer (PMU) after laparoscopic Roux-en-Y gastric bypass (LRYGB) is a serious complication, but its incidence and etiology have rarely been investigated. Therefore, a retrospective review of all patients undergoing LRYGB at the authors' center was conducted to determine the incidence of PMU and whether any causative factors were present. A prospectively kept database of all patients at the authors' bariatric center was retrospectively reviewed. The complete records of patients with a PMU were examined individually for accuracy and analyzed for treatment, outcome, and possible underlying causes of the marginal perforation. Between April 1999 and August 2007, 1% of the patients (35/3,430) undergoing laparoscopic gastric bypass experienced one or more perforated marginal ulcers 3 to 70 months (median, 18 months) after LRYGB. The patients with and without perforation were not significantly different in terms of mean age (37 vs 41 years), weight (286 vs 287 lb), body mass index (BMI) (46 vs 47), or female gender (89% vs 83%). Of the patients with perforations, 2 (6%) were taking steroids, 10 (29%) were receiving nonsteroidal antiinflammatory drugs (NSAIDs) at the time of the perforation, 18 (51%) were actively smoking, and 6 of the smokers also were taking NSAIDs. Eleven of the patients (31%) who perforated did not have at least one of these possible risk factors, but 4 (36%) of the 11 patients in this group had been treated after bypass for a marginal ulcer. Only 7 (20%) of the 35 patients who had laparoscopic bypass, or 7 (0.2%) in the entire group of 3,430 patients, perforated without any warning. There were no deaths, but three patients reperforated. The incidence of a marginal ulcer perforating after LRYGB was significant (>1%) and appeared to be related to smoking or the use of NSAIDs or steroids. Because only 0.2% of all patients acutely perforated without some risk factor or warning, long-term ulcer prophylaxis or treatment may be necessary

  4. Imaging gastrointestinal perforation in pediatric blunt abdominal trauma

    International Nuclear Information System (INIS)

    Jamieson, D.H.; Babyn, P.S.; Pearl, R.

    1996-01-01

    Objective. To assess the role of imaging, in particular CT, in the early detection of GI perforation. Subjects and methods. In a 10-year period, 43 patients with surgically confirmed GI perforation were identified from hospital records; 22 of these had preoperative CT evaluation. Medical records and radiology were retrospectively reviewed and CT studies were particularly assessed for extraluminal air, free intraperitoneal fluid, bowel wall thickening, bowel wall enhancement, and bowel dilatation. During the study period an additional 12 trauma patients were identified who had CT studies demonstrating the above findings, but who had hypovolemic shock bowel or nondisrupting bowel injury without perforation evident. Results. Extraluminal air was demonstrated in 47 % of the imaged perforations. There was one false-positive extraluminal air. Perforation was confirmed in patients who had all five of the above CT findings, but this was the case for only 18 % of patients with perforation. One or more of the five specified CT findings were present in all CT studies reviewed. No false-negative CT study was performed in the study period. Conclusion. Separating nondisrupting bowel injury from perforation is diagnostically difficult; however, CT remains a good modality for assessing GI perforation in pediatric blunt trauma, but it cannot replace diligent and repeated clinical evaluation of all potential perforation victims. (orig.). With 4 figs., 1 tab

  5. Separation and recombinatiuon of charge carriers in solar cells with a nanostructured ZnO electrode; Trennung und Rekombination von Ladungstraegern in Solarzellen mit nanostrukturierter ZnO-Elektrode

    Energy Technology Data Exchange (ETDEWEB)

    Tornow, Julian

    2010-03-02

    The publication investigates electrodes consisting of ZnO nanorods deposited hydrothermally on conductive glass substrate (conductive glass). The electrodes are transparent to visible light and are sensitized for solar cell applications by a light-absorbing layer which in this case consists either of organometallic dye molecules (N3) or of an indium sulfide layer with a thickness of only a few nanometers. Electric contacts for the sensitized electrode are either made of a liquid electrolyte or of a perforated solid electrolyte. Methods of analysis were impedance spectroscopy, time-resolved photocurrent measurements, and time-resolved microwave photoconductivity. A high concentration of up to 10{sup 20} was found in the ZnO nanorods. The dye-sensitized solar cell showed exessively fast recombination with the oxydized dye molecules (sub-{mu}s) but a slow recombination rate with the oxydized redox ions of the electrolyte (ms). In the indium sulfide solar cells, the charges are separated at the contact with the ZnO nanorods while contact with the perforated CuSCN conductor is not charge-separating. Recombination takes place in indium sulfide, directly between the perforated conductor and ZnO, and also via the charge-separating contact with decreasing rates.

  6. Experimental perforation of tubing with a hydraulic sand jet

    Energy Technology Data Exchange (ETDEWEB)

    Semenov, Yu V

    1970-01-01

    A series of field tests has shown that perforation with a hydraulic sand jet improves the quality of well completion. The sand jet does not crack the cement sheath or the casing, and the perforations are larger and deeper than perforations formed by explosive charges. Fluid circulation during sand jet perforation can safely be stopped for at least 10 min. Water containing a surfactant can be used as a sand carrier. Sand jet perforation allows successful completion of wells cased by 2 tubing strings. Sand jet perforation can be used to clean the borehole well and to remove foreign objects from the well.

  7. Perforated Sigmoid Diverticular Disease: a Management Protocol

    Science.gov (United States)

    Moin, Thajammul

    2008-01-01

    Background: To develop an evidence-based protocol for the management of perforated sigmoid diverticular disease. Methods: A search of the literature was undertaken. All publications pertaining to perforated sigmoid diverticular disease were analyzed and then categorized according to their level of evidence. Recommendations were then made on the basis of this. Results: Multiple case reports suggest that primary closure of perforation of sigmoid diverticula is safe in the absence of peritoneal contamination. Conclusions: A 2-stage laparoscopic approach incorporating the principles of damage limitation surgery may be a safe strategy in the management of perforated diverticular disease. PMID:18435896

  8. Preparation of reusable conductive activated charcoal plate as a new electrode for industrial wastewater treatment

    Energy Technology Data Exchange (ETDEWEB)

    Ayoubi-Feiz, Baharak; Aber, Soheil [University of Tabriz, Tabriz (Iran, Islamic Republic of)

    2015-10-15

    A conductive activated charcoal plate (ACP) was prepared from a low-cost, abundant, and non-conductive charcoal. The prepared ACP was characterized using N{sub 2} adsorption/desorption isotherms, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). Brunauer-Emmett-Teller (BET) surface area of the charcoal and the ACP was 0.58m{sup 2} g{sup -1} and 461.67m{sup 2} g{sup -1}, respectively. The ACP was employed in textile wastewater treatment using electrosorption process. Response surface methodology (RSM) was applied to design the experiments. The decolorization efficiency of 76% at optimum conditions of voltage=450mV, pH=4, and contact time=120 min indicated that the ACP has promising potential to decolorize textile wastewater. Moreover, the results of the kinetic analyses demonstrated that wastewater treatment followed pseudo-first order kinetic model. The ACP electrode could be regenerated and reused effectively at five successive cycles of electrosorption/electrodesorption.

  9. Perforator anatomy of the ulnar forearm fasciocutaneous flap.

    Science.gov (United States)

    Mathy, Jon A; Moaveni, Zachary; Tan, Swee T

    2012-08-01

    The ulnar forearm fasciocutaneous flap (UFFF) is a favourable alternative to the radial forearm flap when thin and pliable tissue is required. The precise anatomy of the cutaneous perforators of UFFF has not been previously reported. The position of cutaneous perforators>0.5 mm was recorded while raising 52 consecutive free UFFFs in 51 patients at our Centre. Three (6%) UFFFs in two patients demonstrated direct cutaneous supply through a superficial ulnar artery, a known anatomic variance. There was no cutaneous perforator>0.5 mm in one flap. Among the remaining 48 dissections, an average of 3 (range, 1-6) cutaneous perforators were identified. Ninety-four percent of these forearms demonstrated at least one perforator>0.5 mm within 3 cm, and all had at least one perforator within 6 cm of the midpoint of the forearm. Proximal perforators were more likely to be musculo-cutaneous through the edge of flexor carpi ulnaris or flexor digitorum superficialis, while mid- to distal perforators were septo-cutaneous. UFFF skin paddle designed to overlie an area within 3 cm of the midpoint between the medial epicondyle and the pisiform is most likely to include at least one cutaneous perforator from the ulnar artery, without a need for intra-operative skin island adjustment. This novel anatomic finding and other practical generalisations are discussed to facilitate successful elevation of UFFF. Copyright © 2012 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  10. Perforated gastric carcinoma in a young-age patient

    Directory of Open Access Journals (Sweden)

    Feng-Hsu Wu

    2018-06-01

    Full Text Available Perforation is a rare complication of gastric carcinoma, and it occurs in less than 5% of all gastric carcinoma cases and in less than 1% within all acute abdomen cases. The diagnosis of malignancy is usually not validated preoperatively. In previous reported English literature, all patients with perforated gastric cancer have the feature of old age. This feature might be able to guide the surgeon to impress the differential diagnosis of malignancy before or during the emergent operation of gastric perforation.This 32-year-old male patient suffered from sudden onset of epigastric pain. We performed emergent operation under the impression of hollow organ perforation. The postoperative pathologic report of gastric ulcer revealed gastric carcinoma. We performed second-stage operation of total gastrectomy with D2 lymphadenectomy smoothly 7 days later. As we know, this is the youngest patient having the condition of perforated gastric carcinoma reported in the literature. This case reminds us that it is possible for perforated gastric carcinoma to occur in young-age patients. Keywords: Gastric cancer, Acute abdomen, Gastric perforation

  11. High surface area bio-waste based carbon as a superior electrode for vanadium redox flow battery

    Science.gov (United States)

    Maharjan, Makhan; Bhattarai, Arjun; Ulaganathan, Mani; Wai, Nyunt; Oo, Moe Ohnmar; Wang, Jing-Yuan; Lim, Tuti Mariana

    2017-09-01

    Activated carbon (AC) with high surface area (1901 m2 g-1) is synthesized from low cost bio-waste orange (Citrus sinensis) peel for vanadium redox flow battery (VRB). The composition, structure and electrochemical properties of orange peel derived AC (OP-AC) are characterized by elemental analyzer, field emission-scanning electron microscopy, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, cyclic voltammetry (CV), and electrochemical impedance spectroscopy. CV results show that OP-AC coated bipolar plate demonstrates improved electro-catalytic activity in both positive and negative side redox couples than the pristine bipolar plate electrode and this is ascribed to the high surface area of OP-AC which provides effective electrode area and better contact between the porous electrode and bipolar plate. Consequently, the performance of VRB in a static cell shows higher energy efficiency for OP-AC electrode than the pristine electrode at all current densities tested. The results suggest the OP-AC to be a promising electrode for VRB applications and can be incorporated into making conducting plastics electrode to lower the VRB cell stack weight and cost.

  12. PERFORATED PEPTIC ULCER: A CLINICAL ANALYSIS AND OUTCOME

    OpenAIRE

    Bijit

    2016-01-01

    BACKGROUND The incidence of perforated peptic ulcer is approximately 7-10 cases per one lakh population per year. Perforation is seen in about 7% of patients hospitalized for peptic ulcer disease. Peptic ulcer perforation, which can be gastric/duodenal perforation can be a serious life-threatening condition if not detected early and treated urgently. Peptic ulcer disease has decreased considerably worldwide with the advent of potent anti-ulcer medicines, but its complication l...

  13. Microsecond Electrical Discharge in Water in Plate-to-Plate Configuration With Nitrogen Bubble Injection

    Czech Academy of Sciences Publication Activity Database

    Stelmashuk, Vitaliy

    2016-01-01

    Roč. 44, č. 4 (2016), s. 702-707 ISSN 0093-3813 Institutional support: RVO:61389021 Keywords : Electric breakdown * plate electrodes * underwater discharge Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.052, year: 2016 http://ieeexplore.ieee.org/xpl/tocresult.jsp?isnumber=7450213

  14. Perforated membrane-type acoustic metamaterials

    International Nuclear Information System (INIS)

    Langfeldt, F.; Kemsies, H.; Gleine, W.; Estorff, O. von

    2017-01-01

    This letter introduces a modified design of membrane-type acoustic metamaterials (MAMs) with a ring mass and a perforation so that an airflow through the membrane is enabled. Simplified analytical investigations of the perforated MAM (PMAM) indicate that the perforation introduces a second anti-resonance, where the effective surface mass density of the PMAM is much higher than the static value. The theoretical results are validated using impedance tube measurements, indicating good agreement between the theoretical predictions and the measured data. The anti-resonances yield high low-frequency sound transmission loss values with peak values over 25 dB higher than the corresponding mass-law. - Highlights: • A new membrane-type acoustic metamaterial exhibiting negative density is presented. • The metamaterial design contains a ring mass with a perforation through the membrane. • The sound transmission loss exhibits narrow-band peaks much higher than the mass-law. • The emergence of the peaks is explained using a simple theoretical model. • Impedance tube measurements are used to validate the theoretical predictions.

  15. Perforated membrane-type acoustic metamaterials

    Energy Technology Data Exchange (ETDEWEB)

    Langfeldt, F., E-mail: Felix.Langfeldt@haw-hamburg.de [Department of Automotive and Aeronautical Engineering, Hamburg University of Applied Sciences, Berliner Tor 9, D-20099 Hamburg (Germany); Kemsies, H., E-mail: Hannes.Kemsies@haw-hamburg.de [Department of Automotive and Aeronautical Engineering, Hamburg University of Applied Sciences, Berliner Tor 9, D-20099 Hamburg (Germany); Gleine, W., E-mail: Wolfgang.Gleine@haw-hamburg.de [Department of Automotive and Aeronautical Engineering, Hamburg University of Applied Sciences, Berliner Tor 9, D-20099 Hamburg (Germany); Estorff, O. von, E-mail: estorff@tu-harburg.de [Institute of Modelling and Computation, Hamburg University of Technology, Denickestr. 17, D-21073 Hamburg (Germany)

    2017-04-25

    This letter introduces a modified design of membrane-type acoustic metamaterials (MAMs) with a ring mass and a perforation so that an airflow through the membrane is enabled. Simplified analytical investigations of the perforated MAM (PMAM) indicate that the perforation introduces a second anti-resonance, where the effective surface mass density of the PMAM is much higher than the static value. The theoretical results are validated using impedance tube measurements, indicating good agreement between the theoretical predictions and the measured data. The anti-resonances yield high low-frequency sound transmission loss values with peak values over 25 dB higher than the corresponding mass-law. - Highlights: • A new membrane-type acoustic metamaterial exhibiting negative density is presented. • The metamaterial design contains a ring mass with a perforation through the membrane. • The sound transmission loss exhibits narrow-band peaks much higher than the mass-law. • The emergence of the peaks is explained using a simple theoretical model. • Impedance tube measurements are used to validate the theoretical predictions.

  16. Nano-honeycomb structured transparent electrode for enhanced light extraction from organic light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Xiao-Bo; Qian, Min; Wang, Zhao-Kui, E-mail: zkwang@suda.edu.cn, E-mail: lsliao@suda.edu.cn; Liao, Liang-Sheng, E-mail: zkwang@suda.edu.cn, E-mail: lsliao@suda.edu.cn [Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Institute of Functional Nano and Soft Materials (FUNSOM), and Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou, Jiangsu 215123 (China)

    2015-06-01

    A universal nano-sphere lithography method has been developed to fabricate nano-structured transparent electrode, such as indium tin oxide (ITO), for light extraction from organic light-emitting diodes (OLEDs). Perforated SiO{sub 2} film made from a monolayer colloidal crystal of polystyrene spheres and tetraethyl orthosilicate sol-gel is used as a template. Ordered nano-honeycomb pits on the ITO electrode surface are obtained by chemical etching. The proposed method can be utilized to form large-area nano-structured ITO electrode. More than two folds' enhancement in both current efficiency and power efficiency has been achieved in a red phosphorescent OLED which was fabricated on the nano-structured ITO substrate.

  17. Oriented cluster perforating technology and its application in horizontal wells

    Directory of Open Access Journals (Sweden)

    Huabin Chen

    2016-11-01

    Full Text Available An oriented cluster perforating technology, which integrates both advantages of cluster and oriented perforating, will help solve a series of technical complexities in horizontal well drilling. For realizing its better application in oil and gas development, a series of technologies were developed including perforator self-weight eccentricity, matching of the electronic selective module codes with the surface program control, axial centralized contact signal transmission, and post-perforation intercluster sealing insulation. In this way, the following functions could be realized, such as cable-transmission horizontal well perforator self-weight orientation, dynamic signal transmission, reliable addressing & selective perforation and post-perforation intercluster sealing. The combined perforation and bridge plug or the multi-cluster perforation can be fulfilled in one trip of perforation string. As a result, the horizontal-well oriented cluster perforating technology based on cable conveying was developed. This technology was successfully applied in unconventional gas reservoir exploitation, such as shale gas and coalbed methane, with accurate orientation, reliable selective perforation and satisfactory inter-cluster sealing. The horizontal-well oriented cluster perforating technology benefits the orientation of horizontal well drilling with a definite target and direction, which provides a powerful support for the subsequent reservoir stimulation. It also promotes the fracturing fluid to sweep the principal pay zones to the maximum extent. Moreover, it is conductive to the formation of complex fracture networks in the reservoirs, making quality and efficient development of unconventional gas reservoirs possible.

  18. The value of CT in detecting pathologic bowel perforation

    International Nuclear Information System (INIS)

    Chang, Jong Wun; Shin, Joo Yong; Kim, Hong; Rhee, Chang Soo; Lee, Sung Moon; Joo, Yang Goo; Suh, Soo Jhi

    1997-01-01

    To evaluate the usefulness of CT for assessing the location and cause of pathologic gastrointestinal perforation. A retrospective analysis of abdominal CT was performed in 27 perforations of 26 patients with underlying gastrointestinal pathology. Fifteen benign and 12 malignant perforations consisted of five gastric cancers, one gastric ulcer, ten duodenal bulb ulcers. two bowel adhesions, one jejunal metastasis from lung cancer, one ileocolic Crohn's disease, one radiation colitis and six colon cancers. CT scans were evaluated for 1) diagnosis of bowel perforation, 2) assessment of the cause and site of perforation, and, in particular, differentiation between benignancy and malignancy, and 3) complications and their extent. CT easily detected varying amounts of free air or fluid collection, and infiltration or abscess formation adjacent to the main lesion, and the diagnosis of gastrointestinal perforation was therefore easy. In 11 of the 12 malignancies (92%), primary tumor was diagnosed, but detection of the site of perforation was possible in only seven cases(7/12, 58%). The 15 benign lesions revealed nonspecific CT findings, and the perforation site could be presumed in six (6/15, 40%). In one case of Crohn's disease, the primary cause was visualized. Among six colonic cancers, four pericolic abscesses and two fistulas to adjacent organs were found, but there was no evidence of diffuse peritonitis. CT was helpful to lead to optimal treatment of pathologic gastrointestinal On CT the detectability of perforation, primary benign or malignant lesion, perforation site and extent of complication was high, and this modality was therefore a useful indicator of the optimal treatment for pathologic gastrointestinal perforations.=20

  19. Effect of electrode shape on grounding resistances - Part 2

    DEFF Research Database (Denmark)

    Tomaskovicova, Sonia; Ingeman-Nielsen, Thomas; Christiansen, Anders V.

    2016-01-01

    Although electric resistivity tomography (ERT) is now regarded as a standard tool in permafrost monitoring, high grounding resistances continue to limit the acquisition of time series over complete freeze-thaw cycles. In an attempt to alleviate the grounding resistance problem, we have tested three...... electrode designs featuring increasing sizes and surface area, in the laboratory and at three different field sites in Greenland. Grounding resistance measurements showed that changing the electrode shape (using plates instead of rods) reduced the grounding resistances at all sites by 28%-69% during...... unfrozen and frozen ground conditions. Using meshes instead of plates (the same rectangular shape and a larger effective surface area) further improved the grounding resistances by 29%-37% in winter. Replacement of rod electrodes of one entire permanent permafrost monitoring array by meshes resulted...

  20. Duodenal perforation during percutaneous nephrolithotomy (PCNL ...

    African Journals Online (AJOL)

    A. Bansal

    2016-06-03

    Jun 3, 2016 ... Calculus;. Duodenum;. Injury;. Paediatric;. Percutaneous nephrolithotomy. Abstract. Introduction: Colonic perforations are known complications of percutaneous nephrolithotomy (PCNL). However, to the best of our knowledge, small bowel perforation has rarely been reported.. Observation: We report the ...

  1. External perforated window Solar Screens: The effect of screen depth and perforation ratio on energy performance in extreme desert environments

    KAUST Repository

    Sherif, A.

    2012-09-01

    In hot arid desert environments, the solar radiation passing through windows increases the cooling loads and the energy consumption of buildings. Shading of windows can reduce these loads. Unlike the woven solar screens, wooden solar screens have a thickness that provides selective shading properties. Perforated wooden solar screens were traditionally used for windows shading. Developing modern types of these shading systems can lead to significant energy savings. The paper addresses the influence of changing the perforation percentage and depth of these screens on the annual energy loads, hence defining the optimum depth/perforation configurations for various window orientations. Series of experiments were performed using the EnergyPlus simulation software for a typical residential building in the Kharga Oasis, located in the Egyptian desert. A range of perforation percentages and depths were tested. Conclusions prove that external fixed deep perforated solar screens could effectively achieve energy savings up to 30% of the total energy consumption in the West and South orientations. Optimum range of depths and perforation percentages were recommended. These are: 80-90% perforation rate and 1:1 depth/opening width ratio. These lighter and deeper solar screen configurations were found to be more efficient in energy consumption in comparison with the traditional ones. © 2012 Elsevier B.V. All rights reserved.

  2. Intestinal perforation by an ingested foreign body*

    Science.gov (United States)

    Nicolodi, Gabriel Cleve; Trippia, Cesar Rodrigo; Caboclo, Maria Fernanda F. S.; de Castro, Francisco Gomes; Miller, Wagner Peitl; de Lima, Raphael Rodrigues; Tazima, Leandro; Geraldo, Jamylle

    2016-01-01

    Objective To identify the computed tomography findings suggestive of intestinal perforation by an ingested foreign body. Materials and Methods This was a retrospective study of four cases of surgically proven intestinal perforation by a foreign body, comparing the computed tomography findings with those described in the literature. Results None of the patients reported having ingested a foreign body, all were over 60 years of age, three of the four patients used a dental prosthesis, and all of the foreign bodies were elongated and sharp. In all four patients, there were findings indicative of acute abdomen. None of the foreign bodies were identified on conventional X-rays. The computed tomography findings suggestive of perforation were thickening of the intestinal walls (in all four cases), increased density of mesenteric fat (in all four cases), identification of the foreign body passing through the intestinal wall (in three cases), and gas in the peritoneal cavity (in one case). Conclusion In cases of foreign body ingestion, intestinal perforation is more common when the foreign body is elongated and sharp. Although patients typically do not report having ingested such foreign bodies, the scenario should be suspected in elderly individuals who use dental prostheses. A computed tomography scan can detect foreign bodies, locate perforations, and guide treatment. The findings that suggest perforation are thickening of the intestinal walls, increased mesenteric fat density, and, less frequently, gas in the peritoneal cavity, often restricted to the point of perforation. PMID:27818542

  3. Intestinal perforation by an ingested foreign body

    International Nuclear Information System (INIS)

    Nicolodi, Gabriel Cleve; Trippia, Cesar Rodrigo; Caboclo, Maria Fernanda F.S.; Castro, Francisco Gomes de; Miller, Wagner Peitl; Lima, Raphael Rodrigues de; Tazima, Leandro; Geraldo, Jamylle

    2016-01-01

    Objective: To identify the computed tomography findings suggestive of intestinal perforation by an ingested foreign body. Materials and Methods: This was a retrospective study of four cases of surgically proven intestinal perforation by a foreign body, comparing the computed tomography findings with those described in the literature. Results: None of the patients reported having ingested a foreign body, all were over 60 years of age, three of the four patients used a dental prosthesis, and all of the foreign bodies were elongated and sharp. In all four patients, there were findings indicative of acute abdomen. None of the foreign bodies were identified on conventional X-rays. The computed tomography findings suggestive of perforation were thickening of the intestinal walls (in all four cases), increased density of mesenteric fat (in all four cases), identification of the foreign body passing through the intestinal wall (in three cases), and gas in the peritoneal cavity (in one case). Conclusion: In cases of foreign body ingestion, intestinal perforation is more common when the foreign body is elongated and sharp. Although patients typically do not report having ingested such foreign bodies, the scenario should be suspected in elderly individuals who use dental prostheses. A computed tomography scan can detect foreign bodies, locate perforations, and guide treatment. The findings that suggest perforation are thickening of the intestinal walls, increased mesenteric fat density, and, less frequently, gas in the peritoneal cavity, often restricted to the point of perforation. (author)

  4. Intestinal perforation by an ingested foreign body.

    Science.gov (United States)

    Nicolodi, Gabriel Cleve; Trippia, Cesar Rodrigo; Caboclo, Maria Fernanda F S; de Castro, Francisco Gomes; Miller, Wagner Peitl; de Lima, Raphael Rodrigues; Tazima, Leandro; Geraldo, Jamylle

    2016-01-01

    To identify the computed tomography findings suggestive of intestinal perforation by an ingested foreign body. This was a retrospective study of four cases of surgically proven intestinal perforation by a foreign body, comparing the computed tomography findings with those described in the literature. None of the patients reported having ingested a foreign body, all were over 60 years of age, three of the four patients used a dental prosthesis, and all of the foreign bodies were elongated and sharp. In all four patients, there were findings indicative of acute abdomen. None of the foreign bodies were identified on conventional X-rays. The computed tomography findings suggestive of perforation were thickening of the intestinal walls (in all four cases), increased density of mesenteric fat (in all four cases), identification of the foreign body passing through the intestinal wall (in three cases), and gas in the peritoneal cavity (in one case). In cases of foreign body ingestion, intestinal perforation is more common when the foreign body is elongated and sharp. Although patients typically do not report having ingested such foreign bodies, the scenario should be suspected in elderly individuals who use dental prostheses. A computed tomography scan can detect foreign bodies, locate perforations, and guide treatment. The findings that suggest perforation are thickening of the intestinal walls, increased mesenteric fat density, and, less frequently, gas in the peritoneal cavity, often restricted to the point of perforation.

  5. Intestinal perforation by an ingested foreign body

    Energy Technology Data Exchange (ETDEWEB)

    Nicolodi, Gabriel Cleve; Trippia, Cesar Rodrigo; Caboclo, Maria Fernanda F.S.; Castro, Francisco Gomes de; Miller, Wagner Peitl; Lima, Raphael Rodrigues de; Tazima, Leandro; Geraldo, Jamylle, E-mail: gabrielnicolodi@gmail.com [Hospital Sao Vicente - Funef, Curitiba, PR (Brazil)

    2016-09-15

    Objective: To identify the computed tomography findings suggestive of intestinal perforation by an ingested foreign body. Materials and Methods: This was a retrospective study of four cases of surgically proven intestinal perforation by a foreign body, comparing the computed tomography findings with those described in the literature. Results: None of the patients reported having ingested a foreign body, all were over 60 years of age, three of the four patients used a dental prosthesis, and all of the foreign bodies were elongated and sharp. In all four patients, there were findings indicative of acute abdomen. None of the foreign bodies were identified on conventional X-rays. The computed tomography findings suggestive of perforation were thickening of the intestinal walls (in all four cases), increased density of mesenteric fat (in all four cases), identification of the foreign body passing through the intestinal wall (in three cases), and gas in the peritoneal cavity (in one case). Conclusion: In cases of foreign body ingestion, intestinal perforation is more common when the foreign body is elongated and sharp. Although patients typically do not report having ingested such foreign bodies, the scenario should be suspected in elderly individuals who use dental prostheses. A computed tomography scan can detect foreign bodies, locate perforations, and guide treatment. The findings that suggest perforation are thickening of the intestinal walls, increased mesenteric fat density, and, less frequently, gas in the peritoneal cavity, often restricted to the point of perforation. (author)

  6. Intestinal perforation by an ingested foreign body

    Directory of Open Access Journals (Sweden)

    Gabriel Cleve Nicolodi

    Full Text Available Abstract Objective: To identify the computed tomography findings suggestive of intestinal perforation by an ingested foreign body. Materials and Methods: This was a retrospective study of four cases of surgically proven intestinal perforation by a foreign body, comparing the computed tomography findings with those described in the literature. Results: None of the patients reported having ingested a foreign body, all were over 60 years of age, three of the four patients used a dental prosthesis, and all of the foreign bodies were elongated and sharp. In all four patients, there were findings indicative of acute abdomen. None of the foreign bodies were identified on conventional X-rays. The computed tomography findings suggestive of perforation were thickening of the intestinal walls (in all four cases, increased density of mesenteric fat (in all four cases, identification of the foreign body passing through the intestinal wall (in three cases, and gas in the peritoneal cavity (in one case. Conclusion: In cases of foreign body ingestion, intestinal perforation is more common when the foreign body is elongated and sharp. Although patients typically do not report having ingested such foreign bodies, the scenario should be suspected in elderly individuals who use dental prostheses. A computed tomography scan can detect foreign bodies, locate perforations, and guide treatment. The findings that suggest perforation are thickening of the intestinal walls, increased mesenteric fat density, and, less frequently, gas in the peritoneal cavity, often restricted to the point of perforation.

  7. Neurodevelopmental outcome after neonatal perforator stroke

    NARCIS (Netherlands)

    Ecury-Goossen, Ginette M; van der Haer, Marit; Smit, Liesbeth S; Feijen-Roon, Monique; Lequin, Maarten; de Jonge, Rogier C J; Govaert, Paul; Dudink, Jeroen

    AIM: To assess outcome after neonatal perforator stroke in the largest cohort to date. METHOD: Survivors from a cohort of children diagnosed with neonatal perforator stroke using cranial ultrasound or magnetic resonance imaging were eligible for inclusion. Recovery and Recurrence Questionnaire

  8. Carbon aerogel electrodes for direct energy conversion

    Science.gov (United States)

    Mayer, Steven T.; Kaschmitter, James L.; Pekala, Richard W.

    1997-01-01

    A direct energy conversion device, such as a fuel cell, using carbon aerogel electrodes, wherein the carbon aerogel is loaded with a noble catalyst, such as platinum or rhodium and soaked with phosphoric acid, for example. A separator is located between the electrodes, which are placed in a cylinder having plate current collectors positioned adjacent the electrodes and connected to a power supply, and a pair of gas manifolds, containing hydrogen and oxygen positioned adjacent the current collectors. Due to the high surface area and excellent electrical conductivity of carbon aerogels, the problems relative to high polarization resistance of carbon composite electrodes conventionally used in fuel cells are overcome.

  9. Duodenal perforation: an unusual complication of sickle cell anemia.

    Science.gov (United States)

    Acıpayam, Can; Aldıç, Güliz; Akçora, Bülent; Çelikkaya, Mehmet Emin; Aşkar, Hasan; Dorum, Bayram Ali

    2014-01-01

    Duodenal perforation in childhood is a rare condition with a high mortality rate if not treated surgically. Primary gastroduodenal perforation is frequently associated with peptic ulcer and exhibits a positive family history. Helicobacter pylorus is the most significant agent. Secondary gastroduodenal perforation may be a finding of specific diseases, such as Crohn disease, or more rarely may be associated with diseases such as cystic fibrosis or sickle cell anemia. A 14-year-old boy presented with abdominal and back pain. The patient was operated on for acute abdomen and diagnosed with duodenal perforation. Helicobacter pylorus was negative. There was no risk factor to account for duodenal perforation other than sickle cell anemia. Surgical intervention was successful and without significant sequelae. Duodenal perforation is a rare entity described in patients with sickle cell anemia. To our knowledge, this is the first report of duodenal perforation in a patient sickle cell anemia.

  10. The value of CT in detecting pathologic bowel perforation

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Jong Wun; Shin, Joo Yong; Kim, Hong; Rhee, Chang Soo; Lee, Sung Moon; Joo, Yang Goo; Suh, Soo Jhi [Keimyung Univ. School of Medicine, Taegu (Korea, Republic of)

    1997-10-01

    To evaluate the usefulness of CT for assessing the location and cause of pathologic gastrointestinal perforation. A retrospective analysis of abdominal CT was performed in 27 perforations of 26 patients with underlying gastrointestinal pathology. Fifteen benign and 12 malignant perforations consisted of five gastric cancers, one gastric ulcer, ten duodenal bulb ulcers. two bowel adhesions, one jejunal metastasis from lung cancer, one ileocolic Crohn's disease, one radiation colitis and six colon cancers. CT scans were evaluated for (1) diagnosis of bowel perforation, (2) assessment of the cause and site of perforation, and, in particular, differentiation between benignancy and malignancy, and (3) complications and their extent. CT easily detected varying amounts of free air or fluid collection, and infiltration or abscess formation adjacent to the main lesion, and the diagnosis of gastrointestinal perforation was therefore easy. In 11 of the 12 malignancies (92%), primary tumor was diagnosed, but detection of the site of perforation was possible in only seven cases(7/12, 58%). The 15 benign lesions revealed nonspecific CT findings, and the perforation site could be presumed in six (6/15, 40%). In one case of Crohn's disease, the primary cause was visualized. Among six colonic cancers, four pericolic abscesses and two fistulas to adjacent organs were found, but there was no evidence of diffuse peritonitis. CT was helpful to lead to optimal treatment of pathologic gastrointestinal On CT the detectability of perforation, primary benign or malignant lesion, perforation site and extent of complication was high, and this modality was therefore a useful indicator of the optimal treatment for pathologic gastrointestinal perforations.=20.

  11. Laparoscopic treatment of perforated appendicitis

    Science.gov (United States)

    Lin, Heng-Fu; Lai, Hong-Shiee; Lai, I-Rue

    2014-01-01

    The use of laparoscopy has been established in improving perioperative and postoperative outcomes for patients with simple appendicitis. Laparoscopic appendectomy is associated with less wound pain, less wound infection, a shorter hospital stay, and faster overall recovery when compared to the open appendectomy for uncomplicated cases. In the past two decades, the use of laparoscopy for the treatment of perforated appendicitis to take the advantages of minimally invasiveness has increased. This article reviewed the prevalence, approaches, safety disclaimers, perioperative and postoperative outcomes of the laparoscopic appendectomy in the treatment of patients with perforated appendicitis. Special issues including the conversion, interval appendectomy, laparoscopic approach for elderly or obese patient are also discussed to define the role of laparoscopic treatment for patients with perforated appendicitis. PMID:25339821

  12. DETERMINATION OF THE TEMPERATURE DISTRIBUTION THE PERFORATED FINS UNDER

    Directory of Open Access Journals (Sweden)

    Aziz7 M. Mhamuad

    2015-02-01

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

  13. Perforated peptic ulcer: How to improve outcome?

    DEFF Research Database (Denmark)

    Møller, Morten Hylander; Adamsen, Sven; Wøjdemann, Morten

    2008-01-01

    Despite the introduction of histamine H(2)-receptor antagonists, proton-pump inhibitors and the discovery of Helicobacter pylori, both the incidence of emergency surgery for perforated peptic ulcer and the mortality rate for patients undergoing surgery for peptic ulcer perforation have increased...... with an emphasis on risks that are preventable. A systematic review including randomized studies was carried out. There are a limited number of studies of patients with peptic ulcer perforation. Most of these studies are of low evidential status. Only a few randomized, controlled trials have been published...... to improve the outcome of patients with peptic ulcer perforation, sepsis needs to be factored into the existing knowledge and treatment Udgivelsesdato: 2008/8/27...

  14. Study of hydrodynamic and mass transfer parameters in pulsed sieve-plate columns

    International Nuclear Information System (INIS)

    Safdari, J.

    2001-01-01

    One of the most important liquid-liquid extractor in industry is pulsed column. The pulsed columns are generally classified into the following categories: 1-Pulsed perforated-plate column. 2- Pulsed packed column. The pulsed plate column is differential contactor with the application of mechanical energy and is used for a diverse range of processes. Probably its best known application has been in the nuclear fuel industry. The pulsed plate column consists of a cylindrical shell with settling zones at the top and the bottom of the column. The liquids are fed continuously to the column (flowing counter-currently) and are removed continuously from opposite ends of the column. In this work using a pilot pulsed plate column and two different chemical systems (toluene/acetone/water and n-butyl acetate/acetone/water) various experiments are carried out. In each experiment direction of mass transfer is from organic phase (dispersed phase) into aqueous phase (continuous phase) and the continuous phase is water. The main objects of this thesis are as follow: a- Investigation of effect of operating parameters on dispersed phase hold up, volumetric overall mass transfer coefficients based on dispersed and continuous phase, extraction efficiency, pressure drop of column and flooding velocities (maximum column capacities). Obtained results in this part show that if the calorimetric flow rate of aqueous phase or pulsation intensity increase, hold up, volumetric overall mass transfer coefficients based on both two phases and extraction efficiency will increase and flooding velocities will decrease. Also results show that if volumetric flow rate of organic phase increase, hold up, volumetric mass transfer coefficients based on both two phases and pressure drop will increase and extraction efficiency and flooding velocities will decrease. b- Investigation of effect of internal circulation inside drops in designing pulsed perforated-plate column

  15. Fast track pathway for perforated appendicitis.

    Science.gov (United States)

    Frazee, Richard; Abernathy, Stephen; Davis, Matthew; Isbell, Travis; Regner, Justin; Smith, Randall

    2017-04-01

    Perforated appendicitis is associated with an increased morbidity and length of stay. "Fast track" protocols have demonstrated success in shortening hospitalization without increasing morbidity for a variety of surgical processes. This study evaluates a fast track pathway for perforated appendicitis. In 2013, a treatment pathway for perforated appendicitis was adopted by the Acute Care Surgery Service for patients having surgical management of perforated appendicitis. Interval appendectomy was excluded. Patients were treated initially with intravenous antibiotics and transitioned to oral antibiotics and dismissed when medically stable and tolerating oral intake. A retrospective review of patients managed on the fast track pathway was undertaken to analyze length of stay, morbidity, and readmissions. Thirty-four males and twenty-one females with an average age of 46.8 years underwent laparoscopic appendectomy for perforated appendicitis between January 2013 and December 2014. Pre-existing comorbidities included hypertension 42%, diabetes mellitus 11%, COPD 5% and heart disease 2%. No patient had conversion to open appendectomy. Average length of stay was 2.67 days and ranged from 1 to 12 days (median 2 days). Postoperative morbidity was 20% and included abscess (6 patients), prolonged ileus (3 patients), pneumonia (1 patient), and congestive heart failure (1 patient). Five patients were readmitted for abscess (3 patients), congestive heart failure (1 patient), and pneumonia (1 patient). A fast track pathway for perforated appendicitis produced shorter length of stay and acceptable postoperative morbidity and readmission. This offers the potential for significant cost savings over current national practice patterns. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Long Life Nickel Electrodes for Nickel-Hydrogen Cells: Fiber Substrates Nickel Electrodes

    Science.gov (United States)

    Rogers, Howard H.

    2000-01-01

    Samples of nickel fiber mat electrodes were investigated over a wide range of fiber diameters, electrode thickness, porosity and active material loading levels. Thickness' were 0.040, 0.060 and 0.080 inches for the plaque: fiber diameters were primarily 2, 4, and 8 micron and porosity was 85, 90, and 95%. Capacities of 3.5 in. diameter electrodes were determined in the flooded condition with both 26 and 31% potassium hydroxide solution. These capacity tests indicated that the highest capacities per unit weight were obtained at the 90% porosity level with a 4 micron diameter fiber plaque. It appeared that the thinner electrodes had somewhat better performance, consistent with sintered electrode history. Limited testing with two-positive-electrode boiler plate cells was also carried out. Considerable difficulty with constructing the cells was encountered with short circuits the major problem. Nevertheless, four cells were tested. The cell with 95% porosity electrodes failed during conditioning cycling due to high voltage during charge. Discharge showed that this cell had lost nearly all of its capacity. The other three cells after 20 conditioning cycles showed capacities consistent with the flooded capacities of the electrodes. Positive electrodes made from fiber substrates may well show a weight advantage of standard sintered electrodes, but need considerably more work to prove this statement. A major problem to be investigated is the lower strength of the substrate compared to standard sintered electrodes. Problems with welding of leads were significant and implications that the electrodes would expand more than sintered electrodes need to be investigated. Loading levels were lower than had been expected based on sintered electrode experiences and the lower loading led to lower capacity values. However, lower loading causes less expansion and contraction during cycling so that stress on the substrate is reduced.

  17. Aluminum cathode plates in zinc electrowinning cells: microstructural and failure analysis

    International Nuclear Information System (INIS)

    Buarzaiga, M.; Dreisinger, D.; Tromans, D.; Gonzalez, J.A.

    2001-01-01

    The microstructure of aluminum cathode plates used in zinc electrowinning was analyzed using optical microscopy, scanning electron microscopy, and transmission electron microscopy. Three principal phases dominated the microstructure: primary aluminum, uniformly distributed intermetallic particles, and round rosettes. The intermetallics exhibited blade shape morphology, light gray color, and were aligned in the rolling direction. The chemical composition of the intermetallic particles was consistent with FeAl 3 . Angular particles of elemental silicon were also detected. Failure characteristics of industrial cathode plates were analyzed using optical microscopy, scanning electron microscopy, energy dispersive x-ray analysis, and x-ray diffraction analysis. Three distinct corrosion zones were identified on failed plates: Zone I below the electrolyte/air interface, Zone II 0-40 mm above the electrolyte/air interface, and Zone III 40-140 mm above the electrolyte/air interface. After 24 months in service, the corrosion damage in Zones I and III was equivalent to ca. 10% reduction in plate thickness. Zone II experienced the greatest corrosion damage; the reduction in plate thickness was ca. 80%. Some plates exhibited severe thinning and perforation, which occurred preferentially near the electrical contact edge. Plates often fail in service by fracture in Zone II. (author)

  18. The Heidelberg Appendicitis Score Predicts Perforated Appendicitis in Children.

    Science.gov (United States)

    Boettcher, Michael; Günther, Patrick; Breil, Thomas

    2017-10-01

    In the future, surgical management of pediatric appendicitis might become limited to nonperforating appendicitis. Thus, it becomes increasingly important to differentiate advanced from simple appendicitis and to predict perforated appendicitis among a group of children with right-sided abdominal pain, which was the aim of this study. An institutionally approved, single-center retrospective analysis of all patients with appendectomy from January 2009 to December 2010 was conducted. All diagnostic aspects were evaluated to identify predictors and differentiators of perforated appendicitis. In 2 years, 157 children suffered from appendicitis. Perforation occurred in 47 (29.9%) of the patients. C-reactive protein (CRP) levels higher than 20 mg/dL ( P = .037) and free abdominal fluid on ultrasonography ( P = .031) are the most important features to differentiate perforated from simple appendicitis. Moreover, all children with perforation had a positive Heidelberg Appendicitis Score (HAS). A negative HAS excludes perforation in all cases (negative predictive value = 100%). Perforated appendicitis can be ruled out by the HAS. In a cohort with right-sided abdominal pain, perforation should be considered in children with high CRP levels and free fluids or abscess formation on ultrasound.

  19. Medicolegal aspects of iatrogenic root perforations

    DEFF Research Database (Denmark)

    Tsesis, I; Rosen, E; Bjørndal, L

    2014-01-01

    AIM: To retrospectively analyze the medico-legal aspects of iatrogenic root perforations (IRP) that occurred during endodontic treatments. METHODOLOGY: A comprehensive search in a professional liability insurance database was conducted to retrospectively identify cases of IRP following root canal...... treatment (p root perforation is a complication of root canal treatment and may result in tooth extraction...... and in legal actions against the treating practitioner. Mandibular molars are more prone to medico-legal claims related to root perforations. The patient should be informed of the risks during RCT and should get information on alternative treatments and their risks and prognosis...

  20. Spontaneous ileal perforation complicating low anorectal malformation

    Directory of Open Access Journals (Sweden)

    TiJesuni Olatunji

    2015-01-01

    Full Text Available Anorectal malformation is a common anomaly in neonates. Although colorectal perforations have been reported as a complication, ileal perforation is rarely encountered. This is a report of a 2-day-old boy presenting with a low anorectal malformation, complicated with ileal perforation, necessitating laparotomy and ileal repair. Anoplasty was done for the low anomaly. Early presentation and prompt treatment of anorectal malformations is important to prevent such potential life threatening complication.

  1. Microvascular anatomy of the cerebellar parafloccular perforating space.

    Science.gov (United States)

    Sosa, Pablo; Dujovny, Manuel; Onyekachi, Ibe; Sockwell, Noressia; Cremaschi, Fabián; Savastano, Luis E

    2016-02-01

    The cerebellopontine angle is a common site for tumor growth and vascular pathologies requiring surgical manipulations that jeopardize cranial nerve integrity and cerebellar and brainstem perfusion. To date, a detailed study of vessels perforating the cisternal surface of the middle cerebellar peduncle-namely, the paraflocculus or parafloccular perforating space-has yet to be published. In this report, the perforating vessels of the anterior inferior cerebellar artery (AICA) in the parafloccular space, or on the cisternal surface of the middle cerebellar peduncle, are described to elucidate their relevance pertaining to microsurgery and the different pathologies that occur at the cerebellopontine angle. Fourteen cadaveric cerebellopontine cisterns (CPCs) were studied. Anatomical dissections and analysis of the perforating arteries of the AICA and posterior inferior cerebellar artery at the parafloccular space were recorded using direct visualization by surgical microscope, optical histology, and scanning electron microscope. A comprehensive review of the English-language and Spanish-language literature was also performed, and findings related to anatomy, histology, physiology, neurology, neuroradiology, microsurgery, and endovascular surgery pertaining to the cerebellar flocculus or parafloccular spaces are summarized. A total of 298 perforating arteries were found in the dissected specimens, with a minimum of 15 to a maximum of 26 vessels per parafloccular perforating space. The average outer diameter of the cisternal portion of the perforating arteries was 0.11 ± 0.042 mm (mean ± SD) and the average length was 2.84 ± 1.2 mm. Detailed schematics and the surgical anatomy of the perforating vessels at the CPC and their clinical relevance are reported. The parafloccular space is a key entry point for many perforating vessels toward the middle cerebellar peduncle and lateral brainstem, and it must be respected and protected during surgical approaches to the

  2. High performance fuel electrodes fabricated by electroless plating of copper on BaZr0.8Ce0.1Y0.1O3-δ proton-conducting ceramic

    Science.gov (United States)

    Patki, Neil S.; Way, J. Douglas; Ricote, Sandrine

    2017-10-01

    The stability of copper at high temperatures in reducing and hydrocarbon-containing atmospheres makes it a good candidate for fabricating fuel electrodes on proton-conducting ceramics, such as BaZr0.9-xCexY0.1O3-δ (BZCY). In this work, the electrochemical performance of Cu-based electrodes fabricated by electroless plating (ELP) on BaZr0.8Ce0.1Y0.1O3-δ is studied with impedance spectroscopy. Three activation catalysts (Pd, Ru, and Cu) are investigated and ELP is compared to a commercial Cu paste (ESL 2312-G) for electrode fabrication. The area specific resistances (ASR) for Pd, Ru, and Cu activations at 700 °C in moist 5% H2 in Ar are 2.1, 3.2, and 13.4 Ω cm2, respectively. That is a 1-2 orders of magnitude improvement over the commercial Cu paste (192 Ω cm2). Furthermore, the ASR has contributions from electrode processes and charge transfer at the electrode/electrolyte interface. Additionally, the morphology of the as-fabricated electrode is unaffected by the activation catalyst. However, heat treatment at 750 °C in H2 for 24 h leads to sintering and large reorganization of the electrode fabricated with Cu activation (micron sized pores seen in the tested sample), while Pd and Ru activations are immune to such reorganization. Thus, Pd and Ru are identified as candidates for future work with improvements to charge transfer required for the former, and better electrode processes required for the latter.

  3. Additional magnetoelectric effect in electrode-arrayed magnetoelectric composite

    Directory of Open Access Journals (Sweden)

    D. A. Pan

    2014-11-01

    Full Text Available An electrode-arrayed magnetoelectric (ME composite was proposed, in which the positive and negative electrodes of the PZT-5H plate (Pb(Zr0.52Ti0.48O3 were equally divided into a 2 × 5 array, while the PZT plate remained intact. The ME voltage coefficients of these 10 sections were measured individually and in parallel/series modes. The magnetoelectric coefficient is doubled compared with un-arrayed condition, when the 10 sections are connected in parallel/series using an optimized connecting sequence derived from the charge matching rule. This scheme can also be applied to other types of layered magnetoelectric composites to obtain additional magnetoelectric effect from the original composite structure.

  4. Homogenization of a thermal problem with the fourier conditions in the thin plates of a heat exchanger

    International Nuclear Information System (INIS)

    Rahmattulla, A.A.; Taghite, M.B.

    1996-01-01

    In this paper was studied a thermal problem with the fourier boundary conditions on the edges of the holes in a periodically perforated plate of a heat exchanger. This problem contains several reduced parameters which can be very small (the period ε of the distribution of the holes, the reduced thickness e of the plate and the three Biot numbers relative to the different parts of the boundary). The homogenization technique was used to estimate the field of temperatures attainable in the upper plate, depending on the relative order of magnitude of the smell parameters. (authors). 9 refs

  5. A Novel Perforator Flap Training Model Using a Chicken Leg.

    Science.gov (United States)

    Cifuentes, Ignacio J; Yañez, Ricardo A; Salisbury, Maria C; Rodriguez, José R; Varas, Julian E; Dagnino, Bruno L

    2016-04-01

    Living animal models are frequently used for perforator flap dissection training, but no ex vivo models have been described. The aim of this study is to present a novel nonliving model for perforator flap training based on a constant perforator in the chicken leg. A total of 15 chicken legs were used in this study. Anatomical dissection of the perforator was performed after its identification using ink injection, and in four of these specimens a perforator-based flap was raised. The anatomical dissection revealed a constant intramuscular perforator with a median length of 5.7 cm. Median proximal and distal vessel diameters were 0.93 and 0.4 mm, respectively. The median dissection time was 77.5 minutes. This study introduces a novel, affordable, and reproducible model for the intramuscular dissection of a perforator-based flap using an ex vivo animal model. Its consistent perforator and appropriate-sized vessels make it useful for training.

  6. Esophageal perforation

    Science.gov (United States)

    ... esophagus into the space around the lungs. Collapsed lung. X-rays taken after you drink a non-harmful dye can help pinpoint the location of the perforation. You may also have chest CT scan look for an abscess in the chest or esophageal cancer.

  7. [Iatrogen perforation of the rectum after colon radiography].

    Science.gov (United States)

    Eggum, R; Kressner, U; Haffner, J

    1998-05-10

    Perforation of the rectum following barium enema is relatively rare, occurring in 1 of 3,000 procedures. Colorectal perforation is a serious condition and early diagnosis is of paramount importance in order to avoid any delay in treating the patient. Direct suture of the perforation, lavage, presacral drainage and stomia are the preferred methods of primary surgical treatment.

  8. Selenium plating of aluminium and nickel surfaces

    International Nuclear Information System (INIS)

    Qureshi, N.; Shams, N.; Kamal, A.; Ashraf, A.

    1993-01-01

    Selenium exhibits photovoltaic and photoconductive properties. This makes selenium useful in the production of photocells, exposure meters for photographic use, in solar cells, etc. In commerce, selenium coated surfaces are extensively used as photo receptive drums in the xerography machines for reproducing documents. Laboratory experiments were designed to obtain selenium plating on different materials. Of the various electrodes tested for cathodic deposition, anodized aluminum and nickel plated copper were found to give good results. (author)

  9. Perforated duodenal ulcer: an unusual complication of gastroenteritis.

    OpenAIRE

    Wilson, J M; Darby, C R

    1990-01-01

    A 7 year old boy was admitted to hospital with gastroenteritis, which was complicated by an acute perforated duodenal ulcer. After oversewing of the perforation he made an uncomplicated recovery. Peptic ulceration is under-diagnosed in childhood and this leads to delay in diagnosis and appropriate management. Ulceration is associated with severe illness and viral infections, but perforation is rare.

  10. Iatrogen perforation of the rectum following barium enema

    International Nuclear Information System (INIS)

    Eggum, R.; Kressner, U.; Haffner, J.

    1998-01-01

    Perforation of the rectum following barium enema is relatively rare, occurring in 1 of 3,000 procedures. Colorectal perforation is a serious condition and early diagnosis is of paramount importance in order to avoid any delay in treating the patient. Direct suture of the perforation, lavage, presacral drainage and stomia are the preferred methods of primary surgical treatment. 10 refs., 1 fig

  11. Characteristics of martensite as a function of the Ms temperature in low-carbon armour steel plates

    International Nuclear Information System (INIS)

    Maweja, Kasonde; Stumpf, Waldo; Berg, Nic van der

    2009-01-01

    The microstructure, morphology, crystal structure and surface relief of martensite in a number of experimental armour steel plates with different M s temperatures were analysed. Atomic force microscopy, thin foil transmission electron microscopy and scanning electron microscopy allowed the identification of three groups of low-carbon martensitic armour steels. The investigation showed that the size of individual martensite products (plates or packets, laths or blocks) increases as the M s temperature increases. Comparison of ballistic performances suggests that the morphology (plate or lath) and size of the individual martensite products dictate the effective 'grain size' in resisting fracture or perforation due to ballistic impact.

  12. Testing electrode suitability for field stimulation of high-threshold biological preparations

    Directory of Open Access Journals (Sweden)

    Hugo Fernando Maia Milan

    Full Text Available IntroductionA problem posed by electrical field (E stimulation of biological preparations with high excitation threshold is that the E intensity required for excitation is likely to induce water electrolysis at the electrode surface, which can alter the extracellular medium and cause deleterious effects on the cells. In this study, different electrode materials and geometries were tested aiming at identifying electrode configurations that could transduce the E intensity required for exciting ventricular cardiomyocytes isolated from neonatal rats (threshold E ~30 V/cm without causing water electrolysis.MethodsWire and plate electrodes made of platinum, stainless steel and nickel/chrome alloy were used. The effect of blasting the electrode surface with sand and NaHCO3 solution was also tested. Electrodes were inserted into a cell perfusion chamber containing the saline solution routinely used for physiological experiments. During E application for 5 min, the electrode surface and its surroundings were examined at high magnification for the presence of microbubbles, which indicates the occurrence of water electrolysis. The greatest E intensity applied that failed to generate microbubbles (En was estimated.ResultsWhile nickel/chrome and stainless steel electrodes resulted in low En values, the best performance was observed for sandblasted platinum wire (2 mm diameter and plate (25 mm x 5 mm; 0.1 mm thickness electrodes, for which Enwas ≥40 V/cm.ConclusionThese electrode configurations are suitable for effective and safe stimulation of isolated neonatal cardiomyocytes.

  13. Estimation of current density distribution under electrodes for external defibrillation

    Directory of Open Access Journals (Sweden)

    Papazov Sava P

    2002-12-01

    Full Text Available Abstract Background Transthoracic defibrillation is the most common life-saving technique for the restoration of the heart rhythm of cardiac arrest victims. The procedure requires adequate application of large electrodes on the patient chest, to ensure low-resistance electrical contact. The current density distribution under the electrodes is non-uniform, leading to muscle contraction and pain, or risks of burning. The recent introduction of automatic external defibrillators and even wearable defibrillators, presents new demanding requirements for the structure of electrodes. Method and Results Using the pseudo-elliptic differential equation of Laplace type with appropriate boundary conditions and applying finite element method modeling, electrodes of various shapes and structure were studied. The non-uniformity of the current density distribution was shown to be moderately improved by adding a low resistivity layer between the metal and tissue and by a ring around the electrode perimeter. The inclusion of openings in long-term wearable electrodes additionally disturbs the current density profile. However, a number of small-size perforations may result in acceptable current density distribution. Conclusion The current density distribution non-uniformity of circular electrodes is about 30% less than that of square-shaped electrodes. The use of an interface layer of intermediate resistivity, comparable to that of the underlying tissues, and a high-resistivity perimeter ring, can further improve the distribution. The inclusion of skin aeration openings disturbs the current paths, but an appropriate selection of number and size provides a reasonable compromise.

  14. Parasacral Perforator Flaps for Reconstruction of Sacral Pressure Sores.

    Science.gov (United States)

    Lin, Chin-Ta; Chen, Shih-Yi; Chen, Shyi-Gen; Tzeng, Yuan-Sheng; Chang, Shun-Cheng

    2015-07-01

    Despite advances in reconstruction techniques, pressure sores continue to present a challenge to the plastic surgeon. The parasacral perforator flap is a reliable flap that preserves the entire contralateral side as a future donor site. On the ipsilateral side, the gluteal muscle itself is preserved and all flaps based on the inferior gluteal artery are still possible. We present our experience of using parasacral perforator flaps in reconstructing sacral defects. Between August 2004 and January 2013, 19 patients with sacral defects were included in this study. All the patients had undergone surgical reconstruction of sacral defects with a parasacral perforator flap. The patients' sex, age, cause of sacral defect, flap size, flap type, numbers of perforators used, rotation angle, postoperative complications, and hospital stay were recorded. There were 19 parasacral perforator flaps in this series. All flaps survived uneventfully except for 1 parasacral perforator flap, which failed because of methicillin-resistant Staphylococcus aureus infection. The overall flap survival rate was 95% (18/19). The mean follow-up period was 17.3 months (range, 2-24 months). The average length of hospital stay was 20.7 days (range, 9-48 days). No flap surgery-related mortality was found. Also, there was no recurrence of sacral pressure sores or infected pilonidal cysts during the follow-up period. Perforator-based flaps have become popular in modern reconstructive surgery because of low donor-site morbidity and good preservation of muscle. Parasacral perforator flaps are durable and reliable in reconstructing sacral defects. We recommend the parasacral perforator flap as a good choice for reconstructing sacral defects.

  15. Acquired perforating dermatosis in a patient with chronic renal failure.

    Science.gov (United States)

    Fernandes, Karen de Almeida Pinto; Lima, Lourenço de Azevedo; Guedes, Juliana Chaves Ruiz; Lima, Ricardo Barbosa; D'Acri, Antônio Macedo; Martins, Carlos José

    2016-01-01

    Perforating dermatoses are a group of skin diseases characterized by transepidermal elimination of dermal material. The disease is divided into two groups: the primary group and the secondary group. The classical or primary perforating dermatoses are subdivided into four types according to the eliminated dermal materials: Kyrle disease, perforating reactive collagenosis, elastosis perforans serpiginosa, and perforating folliculitis. The secondary form is known as acquired perforating dermatosis. The term was proposed in 1989 by Rapini to designate the perforating dermatoses affecting adult patients with systemic disease, regardless of the dermal materials eliminated. This report describes a case of the disease with elimination of collagen and elastic fibers in a patient with chronic renal failure.

  16. Use of pulsed neutron logging to evaluate perforation washing

    International Nuclear Information System (INIS)

    Dimon, C.A.

    1986-01-01

    This invention relates to the use of pulsed neutron logging techniques before and after perforation washing operations are performed to evaluate the degree of success of the perforation washing operations. Well logging operations of a type designed to respond to the difference between a formation immediately behind the well sheath and voids in the formation are performed both before and after the perforation washing operation. differences between the two resulting logs are then indicative of voids created by perforation washing. In a preferred embodiment, pulsed neutron logging is used as the logging technique, while a weighted brine having a high absorption cross section to pulsed neutrons is used as the perforation washing fluid

  17. Idiopathic gastric perforation in an asplenic infant | Olsen | African ...

    African Journals Online (AJOL)

    Introduction: The cause of idiopathic gastric perforations in neonates remains unknown. Perforations of the abdominal oesophagus, stomach and duodenum in infants and children are the rarest type of intestinal perforations. There are 21 reported cases of an idiopathic gastric rupture in nonneonates. Case Report: A ...

  18. CORRELATION BETWEEN TYMPANIC MEMBRANE PERFORATION AND HEARING LOSS

    Directory of Open Access Journals (Sweden)

    Lidija RISTOVSKA

    2016-04-01

    Full Text Available Introduction: Perforation of the tympanic membrane primarily results from middle ear infections, trauma or iatrogenic causes. The perforation causes conductive hearing loss by reducing the surface area available for sound transmission to the ossicular chain. Objective: The objective was to analyze the characteristics of tympanic membrane perforations in relation to hearing loss and to determine the type and degree of hearing loss. Materials and methods: We analyzed audiometric, otoscopic findings and medical reports of 218 patients, 114 males (52.3% and 104 females (47.7%, aged 9 to 75 years (mean age of 47.9 years, examined during the period of November 2012 to October 2015. For statistical data analysis we used Chi-square test with level of significance p<0.05. Results: Most of the patients had unilateral perforations (89% with right ear predominance and involvement of two quadrants of pars tensa (37.2%. Mean air-bone gap was 23.9 dB. The largest air-bone gap was at frequency of 250 Hz. Most of the patients (73.1% had mixed hearing loss (p=0.032, and average hearing thresholds from 21 to 40 dB. Conclusion: Mean air-bone gap is largest at the lower frequencies, and decreases as frequency increases. Size of the perforation has effect on hearing loss. Mean air-bone gap increases with increasing size of the perforation. There is no big difference between the mean air-bone gap in posterior versus anterior perforations.

  19. Gallbladder perforation complicating typhoid fever: report of two cases.

    Science.gov (United States)

    Gali, B M; Ali, N; Agbese, G O; Duna, V D; Dawha, S D; Ismai, G I; Mohammed, M

    2011-01-01

    Gallbladder perforation (GBP) is rare and as a complication of typhoid fever is extremely rare. We present two consecutive patients with GBP diagnosed incidentally at laparotomy. Information on the management of two patients with gallbladder perforation seen at Federal Medical Centre Azare in June and October 2008 was extracted from their case records. The two patients were both males aged 13 years and 16 years. They both presented with high fever of more than 2 weeks duration; and abdominal pain and distension. Both patients had features of generalised peritonitis. Pre-operative diagnoses of typhoid enteric perforation were made based on a positive Widal test. Intra-operative findings however, were that of bile peritonitis and gallbladder perforation. Both had cholecystectomy. Culture of the bile aspirate yielded Salmonella typhi. Gallbladder perforation secondary to typhoid fever should be considered as a differential diagnosis in patients with suspected typhoid enteric perforation in typhoid fever endemic region.

  20. Hyperbilirubinemia as a predictor for appendiceal perforation

    DEFF Research Database (Denmark)

    Burcharth, J; Pommergaard, H C; Rosenberg, J

    2013-01-01

    Delayed or wrong diagnosis in patients with appendicitis can result in perforation and consequently increased morbidity and mortality. Serum bilirubin may be a useful marker for appendiceal perforation. The purpose of this systematic review was to evaluate studies investigating elevated serum...

  1. Sigmoid Colonic Perforation with Faecal Peritonitis due to Faecaloma

    Directory of Open Access Journals (Sweden)

    Ibrahim Khalil

    2014-09-01

    Full Text Available Colon perforation is an uncommon event usually caused by malignancy, diverticular disease, amoebic colitis, steroid therapy, trauma and ulcerative colitis, but stercoral perforation is very rare. Severe chronic constipation is considered to be the main causative factor in development of stercoral perforation of colon. Sometimes it can also produce catastrophic complications like colonic obstruction, faecal peritonitis and septicaemia. We report a rare case of sigmoid colonic perforation with faecal peritonitis and pneumoperitonium due to faecaloma which was diagnosed after exploratory laparotomy.

  2. Peptic ulcer perforation

    African Journals Online (AJOL)

    FinePrint

    2015-06-01

    Jun 1, 2015 ... Peptic ulcer perforation is one of the surgical complications of peptic ulcer ... Treatment can be operative or non-operative followed by proton .... chronic gastritis without evidence of ... inhibits pancreatic bicarbonate secretion.

  3. Electrochemical determination of ascorbic acid at p-phenylenediamine film-holes modified glassy carbon electrode

    Directory of Open Access Journals (Sweden)

    Olana Bikila Nagasa

    2015-01-01

    Full Text Available In this work the determination of ascorbic acid (AA at glassy carbon electrode (GCE modified with a perforated film produced by reduction of diazonium generated in situ from p-phenylenediamine (PD is reported. Holes were intentionally created in the modifier film by stripping a pre-deposited gold nanoparticles. The modified electrodes were electrochemically characterized by common redox probes: hydroquinone, ferrocyanide and hexamineruthenium(III. The cyclic voltammetric and amperometric response of AA using the modified electrodes was compared with that of bare GCE. The bare GCE showed a linear response to AA in the concentration range of 5 mM to 45 mM with detection limit of 1.656 mM and the modified GCE showed a linear response to AA in the concentration range of 5 μM to 45 μM with detection limit of 0.123 μM. The effect of potential intereferents on amperometric signal of AA at the modified GCE was examined and found to be minimal. The inter-electrode reproducibility, stability, and accuracy were determined. The modified electrode showed excellent inter-electrode reproducibility, accuracy and stability. The modified electrode reported is a promising candidate for use in electroanalysis of AA.

  4. Perforated peptic ulcer following gastric bypass for obesity.

    Science.gov (United States)

    Macgregor, A M; Pickens, N E; Thoburn, E K

    1999-03-01

    Peptic ulcer in the excluded segment of a gastric bypass performed in the management of morbid obesity has only rarely been reported in the literature. The purpose of this study is to review our experience with the condition in a series of 4300 patients who underwent gastric-restrictive surgery between 1978 and 1997. Eleven patients presented with acute perforation of a peptic ulcer in the excluded gastric segment. Nine ulcers were duodenal, one was gastric, and one patient had both gastric and duodenal perforations. The time between primary gastric-restrictive surgery and ulcer perforation varied from 20 days to 12 years. All patients presented with upper abdominal pain. The classical radiological sign of perforated peptic ulcer, free air under the diaphragm, did not occur in any patient. Nine patients were initially treated by primary closure of the perforation with subsequent definitive ulcer therapy by vagotomy, pyloroplasty, or gastrectomy. One case, initially treated elsewhere, was managed by placement of a Malecot catheter through the duodenal perforation, gastrostomy, and peritoneal drainage. One recent case remains symptom-free on H2 blockers after simple closure. There was no mortality. Six cases were previously reported in the literature with a 33 per cent mortality rate.

  5. Stercoral perforation in a 17-year old.

    LENUS (Irish Health Repository)

    McHugh, S

    2012-02-01

    INTRODUCTION: Stercoral perforation is a rare cause of perforation. This is the first reported case where a partial eating disorder (ED) is the primary causative differential. CASE PRESENTATION: We present the case of a 17-year-old girl who presented to her local Emergency Department with a 24-h history of left-sided abdominal pain. She subsequently deteriorated and a computed tomography scan of her abdomen showed gross distension of the large bowel with a sigmoid perforation. She underwent total colectomy with end ileostomy. Histology reported stercoral perforation but normal bowel ganglia. While an inpatient she was reviewed by the Psychiatric team who were concerned she was suffering from a partial ED. CONCLUSION: This case highlights the importance of a multidisciplinary approach in optimally treating patients such as these. Aggressive medical management with involvement of a psychiatric team and dietetics addresses any underlying causative psychiatric issues and helps prevent recurrence.

  6. Stercoral perforation in a 17-year old.

    LENUS (Irish Health Repository)

    McHugh, S

    2009-04-02

    INTRODUCTION: Stercoral perforation is a rare cause of perforation. This is the first reported case where a partial eating disorder (ED) is the primary causative differential. CASE PRESENTATION: We present the case of a 17-year-old girl who presented to her local Emergency Department with a 24-h history of left-sided abdominal pain. She subsequently deteriorated and a computed tomography scan of her abdomen showed gross distension of the large bowel with a sigmoid perforation. She underwent total colectomy with end ileostomy. Histology reported stercoral perforation but normal bowel ganglia. While an inpatient she was reviewed by the Psychiatric team who were concerned she was suffering from a partial ED. CONCLUSION: This case highlights the importance of a multidisciplinary approach in optimally treating patients such as these. Aggressive medical management with involvement of a psychiatric team and dietetics addresses any underlying causative psychiatric issues and helps prevent recurrence.

  7. Fabrication of resistive plate chamber using bakelite

    International Nuclear Information System (INIS)

    Neog, Himangshu; Bhuyan, M.R.; Biswas, S.; Mohanty, B.; Mohanty, Rudranarayan; Rudra, Sharmili; Sahu, P.K.; Sahu, S.

    2014-01-01

    Now a days Resistive Plate Chamber (RPC) is one of the most important detectors in the High Energy Physics (HEP) experiments. RPC is a gas filled detector utilizing a constant and uniform electric field produced between two parallel electrode plates made of a material with high bulk resistivity e.g. glass or bakelite. RPC has good time resolution (1-2 ns) and spatial resolution (∼ cm). The high resistance of RPC plate limits the spark size produced after the ionization of gas due to the passing charged particle. This contribution discusses building of a RPC using bakelite (local sources) and the measurement of the surface resistivity of the detector

  8. Colonic carcinoma with multiple small bowel perforations mimicking intestinal obstruction

    Directory of Open Access Journals (Sweden)

    Khanna Rahul

    2006-09-01

    Full Text Available Abstract Background Carcinoma of the colon may present with perforation proximal to the site of malignancy. Caecum is the commonest site of perforation if the ileocecal valve is patent and the jejunal and ileal perforations are very rare. Case presentation A 35 year male presented with intestinal obstruction. Emergency laparotomy revealed carcinoma of the transverse colon with multiple pinpoint perforations along antimesenteric border of ileum, which were wrapped with omentum, and no peritoneal contamination was present. Extended right hemicolectomy with jejunocolic anastomosis was done. Patient made uneventful recovery in postoperative period and was treated with adjuvant chemotherapy. Conclusion Patients with colonic carcinoma and incompetent ileocecal valve may present with intestinal perforation. Increased intraluminal pressure and closed loop obstruction may lead to ischemia and perforation of the small bowel.

  9. Arrangement for formation perforating and fracturing

    Energy Technology Data Exchange (ETDEWEB)

    Belyaev, B M; Vitsenii, E M; Zheltov, Yu P; Nikolaev, S I

    1962-03-06

    An arrangement for perforating and hydraulic fracturing, to be lowered on a wire line, consists of a chamber with a shaped charge, a head and a nozzle. This arrangement enables carrying out, simultaneously, the operations of perforating and fracturing. The device may be equipped with separate sections with shaped charges and a powder chamber in which powder charges are placed, designed to be ignited in sequence by slow- acting electric igniters. For controlling the gas pressure and strengthening the arrangement in the zone of perforation, the device is equipped with rubber seals which release the ring elements under pressure of explosive gas. Between the walls of the casing and the rubber seals is an annular space through the gas escapes.

  10. Intraabdominal contamination after gallbladder perforation during laparoscopic cholecystectomy and its complications.

    Science.gov (United States)

    Kimura, T; Goto, H; Takeuchi, Y; Yoshida, M; Kobayashi, T; Sakuramachi, S; Harada, Y

    1996-09-01

    Gallbladder perforation often occurs during laparoscopic cholecystectomy. The frequency and causes of gallbladder perforation as well as the relevant clinical background factors were investigated in 110 patients undergoing laparoscopic cholecystectomy. We also evaluated intraperitoneal contamination by bacteria and gallstones at the time of gallbladder perforation and investigated whether perforation caused early or late postoperative complications. Intraoperative gallbladder perforation occurred in 29 of the 110 patients (26.3%). It was caused by injury with an electric knife during dissection of the gallbladder bed, injury during gallbladder retraction with grasping forceps, injury during gallbladder extraction from the abdomen, and slippage of cystic duct clips (potentially causing bile and stone spillage). Perforation was more frequent in patients with positive bile cultures and in those with pigment stones (p gallbladder perforation is sometimes unavoidable during laparoscopic cholecystectomy, the risk of severe complications appears to be minimized by early closure of perforation, retrieval of as many of the spilled stones as possible, and intraperitoneal lavage.

  11. Electrodes for stochastic cooling of the FNAL antiproton source

    International Nuclear Information System (INIS)

    Voelker, F.

    1982-11-01

    AN electrode array for stochastic cooling is being developed for use on the FNAL antiproton source. With minor power handling modifications, the same electrodes can function as pickups or as kickers. When used as pickups, a large array is needed to increase the signal-to-noise ratio. Each electrode is one element of a pair of directional coupler loops that are mounted flush with the upper and lower walls of the beam chamber. The loops, fabricated from flat metal plates, are supported by specially shaped legs

  12. MRI of perforated gall bladder

    International Nuclear Information System (INIS)

    Sood, B.; Jain, M.; Khandelwal, N.; Singh, P.; Suri, S.

    2002-01-01

    Gall bladder perforation is a dreaded complication of acute cholecystitis that, if not diagnosed early in the course, might have a poor prognosis. Both CT and ultrasonography have been used until now extensively for the diagnosis of acute cholecystitis, but diagnosis of perforation is always difficult. Magnetic resonance, by its superior soft tissue resolution and multiplanar capability, is a better modality and should fare better than ultrasonography and CT, as demonstrated in our case. Magnetic resonance imaging demonstrates the wall of the gall bladder and defects to a much better advantage and more convincingly. In addition, MR colangiopancreatography images demonstrate the biliary tree better than other modalities. We suggest that in the case of acute cholecystitis, if perforation is suspected and CT and ultrasonography are not conclusive, MR should be the modality of choice. It can be used as a first line of investigation; however, it might not be cost-effective. Copyright (2002) Blackwell Science Pty Ltd

  13. Hydrogel based sensor arrays (2 × 2) with perforated piezoresistive diaphragms for metabolic monitoring (in vitro).

    Science.gov (United States)

    Orthner, M P; Lin, G; Avula, M; Buetefisch, S; Magda, J; Rieth, L W; Solzbacher, F

    2010-03-19

    This report details the first experimental results from novel hydrogel sensor array (2 × 2) which incorporates analyte diffusion pores into a piezoresistive diaphragm for the detection of hydrogel swelling pressures and hence chemical concentrations. The sensor assembly was comprised of three components, the active four sensors, HPMA/DMA/TEGDMA (hydroxypropyl methacrylate (HPMA), N,N-dimethylaminoethyl methacrylate (DMA) and crosslinker tetra-ethyleneglycol dimethacrylate (TEGDMA)) hydrogel, and backing plate. Each of the individual sensors of the array can be used with various hydrogels used to measure the presence of a number of stimuli including pH, ionic strength, and glucose concentrations. Ideally, in the future, these sensors will be used for continuous metabolic monitoring applications and implanted subcutaneously. In this paper and to properly characterize the sensor assembly, hydrogels sensitive to changes ionic strength were synthesized using hydroxypropyl methacrylate (HPMA), N,N-dimethylaminoethyl methacrylate (DMA) and crosslinker tetra-ethyleneglycol dimethacrylate (TEGDMA) and inserted into the sensor assembly. This hydrogel quickly and reversibly swells when placed environments of physiological buffer solutions (PBS) with ionic strengths ranging from 0.025 to 0.15 M, making it ideal for proof-of-concept testing and initial characterization. The assembly was wire bonded to a printed circuit board and coated with 3 ± 0.5 μm of Parylene-C using chemical vapor deposition (CVD) to protect the sensor and electrical connections during ionic strength wet testing. Two versions of sensors were fabricated for comparison, the first incorporated diffusion pores into the diaphragm, and the second used a solid diaphragm with perforated backing plate. This new design (perforated diaphragm) was shown to have slightly higher sensitivity than solid diaphragm sensors with separate diffuse backing plates when coupled with the hydrogel. The sensitivities for the 1 mm

  14. The addition of red lead to flat plate and tubular valve regulated miners cap lamp lead-acid batteries

    Energy Technology Data Exchange (ETDEWEB)

    Ferg, E.E.; Loyson, P. [Department of Chemistry, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031 (South Africa); Poorun, A. [Willard Batteries, P.O. Box 1844, Port Elizabeth 6000 (South Africa)

    2006-04-21

    The study looked at the use of red lead in the manufacturing of valve regulated lead acid (VRLA) miners cap lamp (MCL) batteries that were made with either flat plate or tubular positive electrodes. A problem with using only grey oxide in the manufacture of thick flat plate or tubular electrodes is the poor conversion of the active material to the desired lead dioxide. The addition of red lead to the initial starting material improves the formation efficiency but is considerably more expensive thereby increasing the cost of manufacturing. The study showed that by carefully controlling the formation conditions in terms of the voltage and temperature of a battery, good capacity performance can be achieved for cells made with flat plate electrodes that contain up to 25% red lead. The small amount of red lead in the active cured material reduces the effect of electrode surface sulphate formation and allows the battery to achieve its rated capacity within the first few cycles. Batteries made with flat plate positive electrodes that contained more that 50% red lead showed good initial capacity but had poor structural active material bonding. The study showed that MCL batteries made with tubular positive electrodes that contained less than 75% red lead resulted in a poorly formed electrode with limited capacity utilization. Pickling and soaking times of the tubular electrodes should be kept at a minimum thereby allowing higher active material utilization during subsequent capacity cycling. The study further showed that it is beneficial to use higher formation rates in order to reduce manufacturing time and to improve the active material characteristics. (author)

  15. Isolated resonator gyroscope with a drive and sense plate

    Science.gov (United States)

    Challoner, A. Dorian (Inventor); Shcheglov, Kirill V. (Inventor)

    2006-01-01

    The present invention discloses a resonator gyroscope comprising a vibrationally isolated resonator including a proof mass, a counterbalancing plate having an extensive planar region, and one or more flexures interconnecting the proof mass and counterbalancing plate. A baseplate is affixed to the resonator by the one or more flexures and sense and drive electrodes are affixed to the baseplate proximate to the extensive planar region of the counterbalancing plate for exciting the resonator and sensing movement of the gyroscope. The isolated resonator transfers substantially no net momentum to the baseplate when the resonator is excited.

  16. Characteristics of martensite as a function of the M{sub s} temperature in low-carbon armour steel plates

    Energy Technology Data Exchange (ETDEWEB)

    Maweja, Kasonde, E-mail: mawejak@yahoo.fr [Council for Scientific and Industrial Research, CSIR, Materials Science and Manufacturing, PO Box 395, Pretoria 0001 (South Africa); Department of Materials Science and Metallurgical Engineering, University of Pretoria, Pretoria 0002 (South Africa); Stumpf, Waldo [Department of Materials Science and Metallurgical Engineering, University of Pretoria, Pretoria 0002 (South Africa); Berg, Nic van der [Department of Physics, University of Pretoria, Pretoria 0002 (South Africa)

    2009-08-30

    The microstructure, morphology, crystal structure and surface relief of martensite in a number of experimental armour steel plates with different M{sub s} temperatures were analysed. Atomic force microscopy, thin foil transmission electron microscopy and scanning electron microscopy allowed the identification of three groups of low-carbon martensitic armour steels. The investigation showed that the size of individual martensite products (plates or packets, laths or blocks) increases as the M{sub s} temperature increases. Comparison of ballistic performances suggests that the morphology (plate or lath) and size of the individual martensite products dictate the effective 'grain size' in resisting fracture or perforation due to ballistic impact.

  17. Fouling Resilient Perforated Feed Spacers for Membrane Filtration

    KAUST Repository

    Kerdi, Sarah

    2018-04-24

    The improvement of feed spacers with optimal geometry remains a key challenge for spiral-wound membrane systems in water treatment due to their impact on the hydrodynamic performance and fouling development. In this work, novel spacer designs are proposed by intrinsically modifying cylindrical filaments through perforations. Three symmetric perforated spacers (1-Hole, 2-Hole, and 3-Hole) were in-house 3D-printed and experimentally evaluated in terms of permeate flux, feed channel pressure drop and membrane fouling. Spacer performance is characterized and compared with standard no perforated (0-Hole) design under constant feed pressure and constant feed flow rate. Perforations in the spacer filaments resulted in significantly lowering the net pressure drop across the spacer filled channel. The 3-Hole spacer was found to have the lowest pressure drop (50% - 61%) compared to 0-Hole spacer for various average flow velocities. Regarding permeate flux production, the 0-Hole spacer produced 5.7 L.m-2.h-1 and 6.6 L.m-2.h-1 steady state flux for constant pressure and constant feed flow rate, respectively. The 1-Hole spacer was found to be the most efficient among the perforated spacers with 75% and 23% increase in permeate production at constant pressure and constant feed flow, respectively. Furthermore, membrane surface of 1-Hole spacer was found to be cleanest in terms of fouling, contributing to maintain higher permeate flux production. Hydrodynamic understanding of these perforated spacers is also quantified by performing Direct Numerical Simulation (DNS). The performance enhancement of these perforated spacers is attributed to the formation of micro-jets in the spacer cell that aided in producing enough unsteadiness/turbulence to clean the membrane surface and mitigate fouling phenomena. In the case of 1-Hole spacer, the unsteadiness intensity at the outlet of micro-jets and the shear stress fluctuations created inside the cells are higher than those observed with

  18. Fouling resilient perforated feed spacers for membrane filtration.

    Science.gov (United States)

    Kerdi, Sarah; Qamar, Adnan; Vrouwenvelder, Johannes S; Ghaffour, Noreddine

    2018-04-24

    The improvement of feed spacers with optimal geometry remains a key challenge for spiral-wound membrane systems in water treatment due to their impact on the hydrodynamic performance and fouling development. In this work, novel spacer designs are proposed by intrinsically modifying cylindrical filaments through perforations. Three symmetric perforated spacers (1-Hole, 2-Hole, and 3-Hole) were in-house 3D-printed and experimentally evaluated in terms of permeate flux, feed channel pressure drop and membrane fouling. Spacer performance is characterized and compared with standard no perforated (0-Hole) design under constant feed pressure and constant feed flow rate. Perforations in the spacer filaments resulted in significantly lowering the net pressure drop across the spacer filled channel. The 3-Hole spacer was found to have the lowest pressure drop (50%-61%) compared to 0-Hole spacer for various average flow velocities. Regarding permeate flux production, the 0-Hole spacer produced 5.7 L m -2 .h -1 and 6.6 L m -2 .h -1 steady state flux for constant pressure and constant feed flow rate, respectively. The 1-Hole spacer was found to be the most efficient among the perforated spacers with 75% and 23% increase in permeate production at constant pressure and constant feed flow, respectively. Furthermore, membrane surface of 1-Hole spacer was found to be cleanest in terms of fouling, contributing to maintain higher permeate flux production. Hydrodynamic understanding of these perforated spacers is also quantified by performing Direct Numerical Simulation (DNS). The performance enhancement of these perforated spacers is attributed to the formation of micro-jets in the spacer cell that aided in producing enough unsteadiness/turbulence to clean the membrane surface and mitigate fouling phenomena. In the case of 1-Hole spacer, the unsteadiness intensity at the outlet of micro-jets and the shear stress fluctuations created inside the cells are higher than those

  19. Tracheocutaneous Fistula Closure with Turnover Flap and Polydioxanone Plate

    Directory of Open Access Journals (Sweden)

    Justin R. Bryant, DO, MBA

    2017-10-01

    Full Text Available Summary:. An alternative surgical treatment is proposed for closure of tracheocutaneous fistulas. The authors present a new technique for reconstruction of persistent tracheocutaneous fistula resultant from temporary tracheostomy. The single-stage closure under local anesthesia involves a fistulous tract turnover flap with a perforated 0.15 mm polydioxanone plate between the flap and the subcutaneous closure. This article presents 3 cases of persistent tracheocutaneous fistula treated by this method. At follow-up examination after follow-up, no recurrent fistula formation had occurred, and no respiratory deformity was present.

  20. Nasal Septum Perforation due to Methamphetamine abuse

    Directory of Open Access Journals (Sweden)

    Mehdi Bakhshaee

    2012-07-01

    Full Text Available Introduction: Spontaneous Perforation of the nasal septum is an uncommon condition. Nasal inhalation of substances such as cocaine has long been linked to this Perforation. Case Report: This report describes the case of a 46-year-old woman who was addicted to methamphetamine and who presented with perforation of the nasal septum.This is the first reported case of nasal septal necrosis linked to nasal inhalation of methamphetamine. Conclusions: Patient history and assurance regardingillegal drug consumption and abuse is a key point for fast and accurate diagnosis. The pathophysiology of drug-induced sinunasal disease and a review of the literature are also presented.

  1. Spectrum of perforation peritonitis in India--review of 504 consecutive cases.

    Science.gov (United States)

    Jhobta, Rajender Singh; Attri, Ashok Kumar; Kaushik, Robin; Sharma, Rajeev; Jhobta, Anupam

    2006-09-05

    Perforation peritonitis is the most common surgical emergency in India. The spectrum of etiology of perforation in Tropical countries continues to be different from its Western counterpart. The objective of the study was to highlight the spectrum of perforation peritonitis as encountered by us at Government Medical College and Hospital (GMCH), Chandigarh. Five hundred and four consecutive cases of perforation peritonitis over a period of five years were reviewed in terms of clinical presentation, operative findings and postoperative course retrospectively at GMCH, Chandigarh. The most common cause of perforation in our series was perforated duodenal ulcer (289 cases) followed by appendicitis (59 cases), gastrointestinal perforation due to blunt trauma abdomen (45 cases), typhoid fever (41 cases) and tuberculosis (20 cases). Despite delay in seeking medical treatment (53%), the overall mortality (10%) was favourably comparable with other published series though the overall morbidity (50%) was unusually high. In contrast to western literature, where lower gastrointestinal tract perforations predominate, upper gastrointestinal tract perforations constitute the majority of cases in India. The increasing incidence of post-traumatic gastro-enteric injuries may be due to an increase in high speed motor vehicle accidents which warrant early recognition and prompt treatment to avoid serious complications and death.

  2. Spectrum of perforation peritonitis in India-review of 504 consecutive cases

    Directory of Open Access Journals (Sweden)

    Sharma Rajeev

    2006-09-01

    Full Text Available Abstract Background/objective Perforation peritonitis is the most common surgical emergency in India. The spectrum of etiology of perforation in Tropical countries continues to be different from its Western counterpart. The objective of the study was to highlight the spectrum of perforation peritonitis as encountered by us at Government Medical College and Hospital (GMCH, Chandigarh. Methods Five hundred and four consecutive cases of perforation peritonitis over a period of five years were reviewed in terms of clinical presentation, operative findings and postoperative course retrospectively at GMCH, Chandigarh. Results The most common cause of perforation in our series was perforated duodenal ulcer (289 cases followed by appendicitis (59 cases, gastrointestinal perforation due to blunt trauma abdomen (45 cases, typhoid fever (41 cases and tuberculosis (20 cases. Despite delay in seeking medical treatment (53%, the overall mortality (10% was favourably comparable with other published series though the overall morbidity (50% was unusually high. Conclusion In contrast to western literature, where lower gastrointestinal tract perforations predominate, upper gastrointestinal tract perforations constitute the majority of cases in India. The increasing incidence of post-traumatic gastro-enteric injuries may be due to an increase in high speed motor vehicle accidents which warrant early recognition and prompt treatment to avoid serious complications and death.

  3. Silver-coated ion exchange membrane electrode applied to electrochemical reduction of carbon dioxide

    International Nuclear Information System (INIS)

    Hori, Y.; Ito, H.; Okano, K.; Nagasu, K.; Sato, S.

    2003-01-01

    Silver-coated ion exchange membrane electrodes (solid polymer electrolyte, SPE) were prepared by electroless deposition of silver onto ion exchange membranes. The SPE electrodes were used for carbon dioxide (CO 2 ) reduction with 0.2 M K 2 SO 4 as the electrolyte with a platinum plate (Pt) for the counterelectrode. In an SPE electrode system prepared from a cation exchange membrane (CEM), the surface of the SPE was partly ruptured during CO 2 reduction, and the reaction was rapidly suppressed. SPE electrodes made of an anion exchange membrane (SPE/AEM) sustained reduction of CO 2 to CO for more than 2 h, whereas, the electrode potential shifted negatively during the electrolysis. The reaction is controlled by the diffusion of CO 2 through the metal layer of the SPE electrode at high current density. Ultrasonic radiation, applied to the preparation of SPE/AEM, was effective to improve the electrode properties, enhancing the electrolysis current of CO 2 reduction. Observation by a scanning electron microscope (SEM) showed that the electrode metal layer became more porous by the ultrasonic radiation treatment. The partial current density of CO 2 reduction by SPE/AEM amounted to 60 mA cm -2 , i.e. three times the upper limit of the conventional electrolysis by a plate electrode. Application of SPE device may contribute to an advancement of CO 2 fixation at ambient temperature and pressure

  4. Contact lens rehabilitation following repaired corneal perforations

    Science.gov (United States)

    Titiyal, Jeewan S; Sinha, Rajesh; Sharma, Namrata; Sreenivas, V; Vajpayee, Rasik B

    2006-01-01

    Background Visual outcome following repair of post-traumatic corneal perforation may not be optimal due to presence of irregular keratometric astigmatism. We performed a study to evaluate and compare rigid gas permeable contact lens and spectacles in visual rehabilitation following perforating corneal injuries. Method Eyes that had undergone repair for corneal perforating injuries with or without lens aspiration were fitted rigid gas permeable contact lenses. The fitting pattern and the improvement in visual acuity by contact lens over spectacle correction were noted. Results Forty eyes of 40 patients that had undergone surgical repair of posttraumatic corneal perforations were fitted rigid gas permeable contact lenses for visual rehabilitation. Twenty-four eyes (60%) required aphakic contact lenses. The best corrected visual acuity (BCVA) of ≥ 6/18 in the snellen's acuity chart was seen in 10 (25%) eyes with spectacle correction and 37 (92.5%) eyes with the use of contact lens (p < 0.001). The best-corrected visual acuity with spectacles was 0.20 ± 0.13 while the same with contact lens was 0.58 ± 0.26. All the patients showed an improvement of ≥ 2 lines over spectacles in the snellen's acuity chart with contact lens. Conclusion Rigid gas permeable contact lenses are better means of rehabilitation in eyes that have an irregular cornea due to scars caused by perforating corneal injuries. PMID:16536877

  5. Frequency of wound infection in non-perforated appendicitis with use of single dose perforative antibiotics

    International Nuclear Information System (INIS)

    Ali, K.; Latif, H.; Ahmad, S.

    2015-01-01

    Antibiotics are used both pre and post-operatively in acute appendicitis for preventing wound infection. It has been observed that the routine use of post-operative antibiotics is not necessary in cases of non-perforated appendicitis as only prophylactic antibiotics are sufficient to prevent wound infection. The aim of this study was to see the frequency of wound infection in non-perforated appendicitis with single dose preoperative antibiotics only. Method: This observational study was conducted at the Department of Surgery, Ayub Medical College, Abbottabad from May to November 2014. A total of 121 patients with non-perforated appendicitis were included in the study. Only single dose preoperative antibiotics were used. The patients were followed for wound infection till 8th post-operative day. Results: 121 patients, 56(46.28%) male and 65(53.72%) female were included in the study. The mean age of patients was 27.41 ± 7.12 years with an age range of 18 to 45 years. In the entire series, 7(5.78%) patients developed wound infection. The infection was minor which settled with conservative therapy. Prophylactic antibiotics were found efficacious in 114(94.21%) patients. There was no significant association between wound infection and age and gender. Conclusion: Single dose preoperative antibiotics were found effective in controlling post-operative wound infection without the need of extending the antibiotics to post-operative period in cases of non-perforated appendicitis. (author)

  6. Preoperative chest x-ray findings in peptic ulcer perforation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, T. H.; Kim, S. W.; Lim, J. S.; Kim, Y. J. [Kyungpook National University School of Medicine, Taegu (Korea, Republic of)

    1981-12-15

    This study was carried out to analyze the distribution of age, sex, chief complaint, physical examination and findings of chest x-ray films before operation in 59 cases of peptic ulcer perforation. The ratio of male to female was 1.7 : 1 and incidence of the ulcer perforation was most common in 5th decades. Thirty five among 59 cases showed pleural effusion, segmental atelectasis and pneumonic infiltration on chest x-ray film. Twenty nine among 50 cases of duodenal ulcer perforation and 6 of 9 cases of stomach ulcer perforation showed positive chest x-ray findings. No relationship was found between fever and preoperative chest x-ray findings.

  7. Preoperative chest x-ray findings in peptic ulcer perforation

    International Nuclear Information System (INIS)

    Kim, T. H.; Kim, S. W.; Lim, J. S.; Kim, Y. J.

    1981-01-01

    This study was carried out to analyze the distribution of age, sex, chief complaint, physical examination and findings of chest x-ray films before operation in 59 cases of peptic ulcer perforation. The ratio of male to female was 1.7 : 1 and incidence of the ulcer perforation was most common in 5th decades. Thirty five among 59 cases showed pleural effusion, segmental atelectasis and pneumonic infiltration on chest x-ray film. Twenty nine among 50 cases of duodenal ulcer perforation and 6 of 9 cases of stomach ulcer perforation showed positive chest x-ray findings. No relationship was found between fever and preoperative chest x-ray findings

  8. Primary Closure versus Gastric Resection for Perforated Gastric

    African Journals Online (AJOL)

    Perforated gastric ulcer is one of the most life‑threatening complications of peptic ulcer disease with high .... tubes were removed and oral nutrition resumed. The .... surgical approach for perforated gastric cancer: One‑stage vs. two‑stage ...

  9. Study on Dynamic Response of Downhole Tools under Perforation Impact Load

    Directory of Open Access Journals (Sweden)

    Liu Jun

    2017-01-01

    Full Text Available A model of a multibody system is established to investigate the dynamic response of an oil tube-shock absorber-perforating gun system in downhole perforation-test joint operation. In the model, the oil tube and perforating gun are modeled as elastic rods and the shock absorber is modeled as single particle system with damping and a spring. Two force continuity conditions are used to simulate the interactions among the three components. The perforation impact load is determined by an experiment of underwater explosion of perforating bullets. Using the model, the effects of charge quantity of perforating bullet, the number of shock absorbers, and the length of oil tube on the dynamic response of oil tube and packer are investigated. On this basis, a basic principle of the combination design of shock absorber and oil tube is proposed to improve the mechanical state of downhole tools. The study results can provide theoretical support for the design of downhole perforation-test joint operation.

  10. Dielectric behaviors of lead zirconate titanate ceramics with coplanar electrodes

    International Nuclear Information System (INIS)

    Wang, Y.; Cheng, Y.L.; Zhang, Y.W.; Chan, H.L.W.; Choy, C.L.

    2003-01-01

    This paper reports on the dielectric behaviors of lead zirconate titanate (PZT) capacitors with coplanar electrodes. Usually a ferroelectric device has a metal-ferroelectric-metal configuration (parallel plate capacitor); when both the electrodes are on one side of a ceramic to form a coplanar capacitor, different dielectric behaviors will be anticipated because of the change in the distribution of the test field inside the dielectrics. This paper describes how the capacitance and dielectric loss of PZT-based coplanar capacitors change with electrode distance, area and test frequency

  11. Clinical Factors of Delayed Perforation after Endoscopic Submucosal Dissection for Gastric Neoplasms

    Directory of Open Access Journals (Sweden)

    Yoshinobu Yamamoto

    2017-01-01

    Full Text Available Background. Delayed perforation is a rare but severe complication of endoscopic submucosal dissection (ESD for early gastric neoplasm (EGN. The aim of this study was to clarify clinical factors related to delayed perforation after ESD. Methods. A total of 1158 consecutive patients with 1199 EGNs underwent ESD at our hospital between January 2000 and December 2015. Univariate analysis was used to identify clinicopathological factors related to delayed perforation. Moreover, duration of cautery needed for hemostasis was measured by comparison between perforated and nonperforated points in patients with delayed perforation. Results. Delayed perforation occurred in 5 of 1158 consecutive patients with 1199 EGNs who underwent ESD (0.42%. All cases were diagnosed within 24 h after ESD and recovered with conservative management. On univariate analysis, location in the upper stomach was the factor most significantly associated with delayed perforation (P<0.01. Duration of cautery needed for hemostasis was significantly longer at perforated points (9 s than at nonperforated points (3.5 s in five patients. Conclusions. Location in the upper stomach was the risk factor most prominently associated with delayed perforation after ESD for EGNs. In addition, delayed perforation appears associated with excessive electrocautery for hemostasis.

  12. Clinicopathological Analysis of Factors Related to Colorectal Tumor Perforation

    OpenAIRE

    Medina-Arana, Vicente; Martínez-Riera, Antonio; Delgado-Plasencia, Luciano; Rodríguez-González, Diana; Bravo-Gutiérrez, Alberto; Álvarez-Argüelles, Hugo; Alarcó-Hernández, Antonio; Salido-Ruiz, Eduardo; Fernández-Peralta, Antonia M.; González-Aguilera, Juan J.

    2015-01-01

    Abstract Colorectal tumor perforation is a life-threatening complication of this disease. However, little is known about the anatomopathological factors or pathophysiologic mechanisms involved. Pathological and immunohistochemical analysis of factors related with tumoral neo-angiogenesis, which could influence tumor perforation are assessed in this study. A retrospective study of patients with perforated colon tumors (Group P) and T4a nonperforated (controls) was conducted between 2001 and 20...

  13. Predictors of appendiceal perforation in an equal access system.

    Science.gov (United States)

    Walker, Avery; Hatch, Quinton; Drake, Thurston; Nelson, Daniel W; Fitzpatrick, Emilie; Bingham, Jason; Black, George; Maykel, Justin A; Steele, Scott R

    2014-07-01

    Discrepancies in socioeconomic factors have been associated with higher rates of perforated appendicitis. As an equal-access health care system theoretically removes these barriers, we aimed to determine if remaining differences in demographics, education, and pay result in disparate outcomes in the rate of perforated appendicitis. All patients undergoing appendectomy for acute appendicitis (November 2004-October 2009) at a tertiary care equal access institution were categorized by demographics and perioperative data. Rank of the sponsor was used as a surrogate for economic status. A multivariate logistic regression model was performed to determine patient and clinical characteristics associated with perforated appendicitis. A total of 680 patients (mean age 30±16 y; 37% female) were included. The majority were Caucasian (56.4% [n=384]; African Americans 5.6% [n=38]; Asians 1.9% [n=13]; and other 48.9% [n=245]) and enlisted (87.2%). Overall, 6.4% presented with perforation, with rates of 6.6%, 5.8%, and 6.7% (P=0.96) for officers, enlisted soldiers, and contractors, respectively. There was no difference in perforation when stratified by junior or senior status for either officers or enlisted (9.3% junior versus 4.40% senior officers, P=0.273; 6.60% junior versus 5.50% senior enlisted, P=0.369). On multivariate analysis, parameters such as leukocytosis and temperature, as well as race and rank were not associated with perforation (P=0.7). Only age had a correlation, with individuals aged 66-75 y having higher perforation rates (odds ratio, 1.04; 95% confidence interval, 1.02-1.05; P<0.001). In an equal-access health care system, older age, not socioeconomic factors, correlated with increased appendiceal perforation rates. Published by Elsevier Inc.

  14. Influence of operating microscope in the sealing of cervical perforations.

    Science.gov (United States)

    Schmidt, Bruna Schwingel; Zaccara, Ivana Maria; Reis Só, Marcus Vinícius; Kuga, Milton Carlos; Palma-Dibb, Regina Guenka; Kopper, Patrícia Maria Poli

    2016-01-01

    Accidental root canal perforations are among the main complications of endodontic treatment. This study evaluated the influence of operating microscope (OM) in the marginal adaptation of mineral trioxide aggregate (MTA) (Angelus(®)) and glass ionomer (Vitremer) inserted into cervical perforations. Perforations were made in the cervical third of the buccal wall of the root canal in mandibular incisors. Next, the teeth were divided into four groups (N = 10): MG - MTA without OM; VG - Vitremer without OM; MOMG - MTA with OM; VOMG - Vitremer with OM. The perforations were sealed according to the group and the teeth were prepared for analysis by confocal laser scanning microscope. Images of perforation region (1,024×) were made and the gap presented by the materials was measured using the Image J program. LEXT OLS4100 three dimensional (3D) measuring laser microscope measured the volumetric misfit. Data of gap were analyzed by Kruskal-Wallis and Dunn's tests. Analysis of variance (ANOVA) and Tukey's tests compared the volumetric misfits. The results showed lower volume and gap in the interface dentin/material in VOMG compared to the other groups (P < 0.05). The use of OM improved the quality of cervical perforations sealed with Vitremer, being indicated in clinical situations of iatrogenic cervical perforations.

  15. Laparoscopic Primary Colorrhaphy for Acute Iatrogenic Perforations during Colonoscopy

    Directory of Open Access Journals (Sweden)

    Eric M. Haas

    2013-01-01

    Full Text Available Purpose. We present our experience with laparoscopic colorrhaphy as definitive surgical modality for the management of colonoscopic perforations. Methods. Over a 17-month period, we assessed the outcomes of consecutive patients presenting with acute colonoscopic perforations. Patient characteristics and perioperative parameters were tabulated. Postoperative outcomes were evaluated within 30 days following discharge. Results. Five female patients with a mean age of 71.4 ± 9.7 years (range: 58–83, mean BMI of 26.4 ± 3.4 kg/m2 (range: 21.3–30.9, and median ASA score of 2 (range: 2-3 presented with acute colonoscopic perforations. All perforations were successfully managed through laparoscopic colorrhaphy within 24 hours of development. The perforations were secondary to direct trauma (n=3 or thermal injury (n=2 and were localized to the sigmoid (n=4 or cecum (n=1. None of the patients required surgical resection, diversion, or conversion to an open procedure. No intra- or postoperative complications were encountered. The mean length of hospital stay was 3.8 ± 0.8 days (range: 3–5. There were no readmissions or reoperations. Conclusion. Acute colonoscopic perforations can be safely managed via laparoscopic primary repair without requiring resection or diversion. Early recognition and intervention are essential for successful outcomes.

  16. Ricochet of a tungsten heavy alloy long-rod projectile from deformable steel plates

    International Nuclear Information System (INIS)

    Lee, Woong; Lee, Heon-Joo; Shin, Hyunho

    2002-01-01

    Ricochet of a tungsten heavy alloy long-rod projectile from oblique steel plates with a finite thickness was investigated numerically using a full three-dimensional explicit finite element method. Three distinctive regimes resulting from oblique impact depending on the obliquity, namely simple ricochet, critical ricochet and target perforation, were investigated in detail. Critical ricochet angles were calculated for various impact velocities and strengths of the target plates. It was predicted that critical ricochet angle increases with decreasing impact velocities and that higher ricochet angles were expected if higher strength target materials are employed. Numerical predictions were compared with existing two-dimensional analytical models. Experiments were also carried out and the results supported the predictions of the numerical analysis

  17. Esophageal Perforation due to Transesophageal Echocardiogram: New Endoscopic Clip Treatment

    Directory of Open Access Journals (Sweden)

    John Robotis

    2014-07-01

    Full Text Available Esophageal perforation due to transesophageal echocardiogram (TEE during cardiac surgery is rare. A 72-year-old female underwent TEE during an operation for aortic valve replacement. Further, the patient presented hematemesis. Gastroscopy revealed an esophageal bleeding ulcer. Endoscopic therapy was successful. Although a CT scan excluded perforation, the patient became febrile, and a second gastroscopy revealed a big perforation at the site of ulcer. The patient's clinical condition required endoscopic intervention with a new OTSC® clip (Ovesco Endoscopy, Tübingen, Germany. The perforation was successfully sealed. The patient remained on intravenous antibiotics, proton pump inhibitors and parenteral nutrition for few days, followed by enteral feeding. She was discharged fully recovered 3 months later. We clearly demonstrate an effective, less invasive treatment of an esophageal perforation with a new endoscopic clip.

  18. Perforated duodenal diverticulum caused by Bezoar: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eun Jung; Moon, Sung Kyoung; Park, Seong Jin; Lim, Joo Won; Lee, Dong Ho; Ko, Young Tae [Dept. of Radiology, College of Medicine, Kyung Hee University, Seoul (Korea, Republic of)

    2013-11-15

    Duodenal diverticulum is common, but its perforation is a rare complication. Duodenal diverticulum perforation requires prompt treatments because of its high mortality rate. However, an accurate diagnosis is difficult to make due to nonspecific symptoms and signs. It can be misdiagnosed as pancreatitis, cholecystitis, or peptic ulcer. Herein, we report a case of perforated duodenal diverticulum caused by bezoar in a 33-year-old woman whom was diagnosed by abdomen computed tomography and ultrasonography.

  19. Duodenal perforation: an unusual complication of sickle cell anemia

    OpenAIRE

    Acıpayam, Can; Aldıç, Güliz; Akçora, Bülent; Çelikkaya, Mehmet Emin; Aşkar, Hasan; Dorum, Bayram Ali

    2014-01-01

    Duodenal perforation in childhood is a rare condition with a high mortality rate if not treated surgically. Primary gastroduodenal perforation is frequently associated with peptic ulcer and exhibits a positive family history. Helicobacter pylorus is the most significant agent. Secondary gastroduodenal perforation may be a finding of specific diseases, such as Crohn disease, or more rarely may be associated with diseases such as cystic fibrosis or sickle cell anemia. A 14-year-old boy presente...

  20. Spectrum of Perforation Peritonitis in Delhi: 77 Cases Experience

    OpenAIRE

    Yadav, Dinesh; Garg, Puneet K.

    2012-01-01

    Perforation peritonitis is the most common surgical emergency encountered by surgeons all over the world as well in India. The spectrum of etiology of perforation peritonitis in tropical countries continues to differ from its western counterpart. This study was conducted at Hindu Rao Hospital, Municipal Corporation of Delhi, New Delhi, India, designed to highlight the spectrum of perforation peritonitis in the eastern countries and to improve its outcome. This prospective study included 77 co...

  1. Perforated duodenal diverticulum caused by Bezoar: A case report

    International Nuclear Information System (INIS)

    Lee, Eun Jung; Moon, Sung Kyoung; Park, Seong Jin; Lim, Joo Won; Lee, Dong Ho; Ko, Young Tae

    2013-01-01

    Duodenal diverticulum is common, but its perforation is a rare complication. Duodenal diverticulum perforation requires prompt treatments because of its high mortality rate. However, an accurate diagnosis is difficult to make due to nonspecific symptoms and signs. It can be misdiagnosed as pancreatitis, cholecystitis, or peptic ulcer. Herein, we report a case of perforated duodenal diverticulum caused by bezoar in a 33-year-old woman whom was diagnosed by abdomen computed tomography and ultrasonography.

  2. Perforated peptic ulcer

    Science.gov (United States)

    Søreide, Kjetil; Thorsen, Kenneth; Harrison, Ewen M.; Bingener, Juliane; Møller, Morten H.; Ohene-Yeboah, Michael; Søreide, Jon Arne

    2015-01-01

    Summary Perforated peptic ulcer (PPU) is a frequent emergency condition worldwide with associated mortality up to 30%. A paucity of studies on PPU limits the knowledge base for clinical decision-making, but a few randomised trials are available. While Helicobacter pylori and use of non-steroidal anti-inflammatory drugs are frequent causes of PPU, demographic differences in age, gender, perforation location and aetiology exist between countries, as do mortality rates. Clinical prediction rules are used, but accuracy varies with study population. Early surgery, either by laparoscopic or open repair, and proper sepsis management are essential for good outcome. Selected patients can perhaps be managed non-operatively or with novel endoscopic approaches, but validation in trials is needed. Quality of care, sepsis care-bundles and postoperative monitoring need further evaluation. Adequate trials with low risk of bias are urgently needed for better evidence. Here we summarize the evidence for PPU management and identify directions for future clinical research. PMID:26460663

  3. Fragmentation of armor piercing steel projectiles upon oblique perforation of steel plates

    Directory of Open Access Journals (Sweden)

    Aizik F.

    2012-08-01

    Full Text Available In this study, a constitutive strength and failure model for a steel core of a14.5 mm API projectile was developed. Dynamic response of a projectile steel core was described by the Johnson-Cook constitutive model combined with principal tensile stress spall model. In order to obtain the parameters required for numerical description of projectile core material behavior, a series of planar impact experiments was done. The parameters of the Johnson-Cook constitutive model were extracted by matching simulated and experimental velocity profiles of planar impact. A series of oblique ballistic experiments with x-ray monitoring was carried out to study the effect of obliquity angle and armor steel plate thickness on shattering behavior of the 14.5 mm API projectile. According to analysis of x-ray images the fragmentation level increases with both steel plate thickness and angle of inclination. The numerical modeling of the ballistic experiments was done using commercial finite element code, LS-DYNA. Dynamic response of high hardness (HH armor steel was described using a modified Johnson-Cook strength and failure model. A series of simulations with various values of maximal principal tensile stress was run in order to capture the overall fracture behavior of the projectile’s core. Reasonable agreement between simulated and x-ray failure pattern of projectile core has been observed.

  4. Surgical management of perforated duodenal ulcer: the changing scene.

    Science.gov (United States)

    Plummer, J M; McFarlane, M E C; Newnham

    2004-12-01

    To determine the management of perforated duodenal ulcer at the University Hospital of the West Indies (UHWI) in this era of Helicobacter pylori, the medical records of all patients seen at the UHWI during the period July 1997 to June 2002 with an intra-operative diagnosis of perforated peptic ulcer were reviewed The records were analyzed for the following: age, gender, duration of symptoms, non-steroidal anti-inflammatory drug (NSAID) use, smoking status, operative repair duration of hospitalization, Helicobacter pylori status and medical therapy, peri-operative complications, mortality and recurrence. Ninety per cent of the cases were males. All females in whom perforation occurred were age 50 years and older compared to males where 58% of cases presented before age 50 years. Perforations in acute ulcers occurred in 80% of cases. The majority of patients were male smokers. Non-steroidal anti-inflammatory drug use was also an important risk factor in elderly females. Simple surgical closure and standard triple therapy antibiotics to eradicate Helicobacter pylori was the most common treatment offered. Mortality was one per cent and follow-up poor but 11% of patients had documented recurrent peptic ulceration. In this study population, perforated duodenal ulcer occured overwhelmingly in males less than 50 years of age. There is a trend towards exclusive simple surgical closure and H pylori eradication at the UHWI for patients with perforated duodenal ulcer but this needs to be supported by documentation of H pylori prevalence in the population of patients presenting with perforated peptic ulcers.

  5. Factors related to persisting perforations after ventilation tube insertion.

    Science.gov (United States)

    O'Connell Ferster, Ashley P; Tanner, April Michelle; Karikari, Kodjo; Roberts, Christopher; Wiltz, Derek; Carr, Michele M

    2016-02-01

    Over a million ventilation tubes are placed annually in the United States, making this one of the most commonly performed procedures in the field of medicine. Certain factors increase the risk of persistent tympanic membrane perforation following the extrusion of short term ventilation tubes. Persistent perforations may fail to heal on their own, necessitating surgical closure to avoid conductive hearing loss. It is important to detect factors that may predict children who are at increased risk for persistent perforations. This study was a retrospective chart review that involved 757 patients between 2003 and 2008. The patients studied were within the age of 2 months-17 years, and all had short term tubes placed. The chart data also included demographic information, comorbidities, and information related to tube insertion and follow-up care. Chi-square, t-test, and multivariate logistic regression were conducted to compare variables between patients with perforations and those without. Data from 757 patients was analyzed, showing that perforation rate is associated with rhinorrhea, operative tube removal, aural polyps, and otorrhea (OR 1.72, 8.16, 4.69, and 1.72 respectively). The absence of otorrhea decreased the likelihood of TM perforations and no significant differences were found in gender, total number of sets of tubes, type of tube, use of nasal steroids, adenoidectomy, or nasal congestion. Our findings suggest that children with rhinorrhea, otorrhea, aural polyps, or prolonged intubation requiring operative tube removal should be identified clinically as children at risk of persisting perforation. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  6. 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.

  7. Enhancement of plate heat exchanger performance using electric fields

    International Nuclear Information System (INIS)

    Down, E.M.

    2000-12-01

    The falling film plate evaporator is often used in the food processing industry to remove large amounts of water from liquids, pulps and slurries. Although a compact efficient device with high heat transfer rates, there is a requirement for even greater performance, particularly when fuelled by the low grade energy from many renewable sources. Electrohydrodynamics (EHD) has been shown to give large heat transfer enhancements under many conditions, but most of this previous research has been with working fluids having much lower electrical conductivities than the water-based fluids that are the main concern of this study. The liquid flow in falling film plate evaporators is in the form of a very thin (less than a millimetre) film falling down a heated plate under the effect of gravity. The film surface exhibits waviness over much of the operating range of industrial heat exchangers, and the degree of waviness has previously been shown to have a large effect on the rate of heat transfer. A theoretical model was developed which suggested that significant increases in waviness, and therefore heat transfer, could be stimulated using high voltage electrodes, and these were subsequently observed on the surface of a pool of water during bench-top experiments. An experimental falling film rig was designed to study this EHD effect but the 2.5 kV maximum voltage attainable was thought to be too low to stimulate wave enlargement and no heat transfer enhancement was seen. Significant heat transfer enhancement was observed in the falling film rig when utilising corona discharge electrodes. This was thought to be due to a thinning of the film in the vicinity of the electrode via the corona wind and increased fluid mixing downstream of the electrode. Both point and wire electrodes improved heat transfer rates but wire electrodes were thought to have more potential for integration into existing industrial heat exchanger designs, so were studied more closely. Heat transfer rates

  8. Spectrum of perforation peritonitis in India-review of 504 consecutive cases

    OpenAIRE

    Jhobta, Rajender Singh; Attri, Ashok Kumar; Kaushik, Robin; Sharma, Rajeev; Jhobta, Anupam

    2006-01-01

    Abstract Background/objective Perforation peritonitis is the most common surgical emergency in India. The spectrum of etiology of perforation in Tropical countries continues to be different from its Western counterpart. The objective of the study was to highlight the spectrum of perforation peritonitis as encountered by us at Government Medical College and Hospital (GMCH), Chandigarh. Methods Five hundred and four consecutive cases of perforation peritonitis over a period of five years were r...

  9. Diaphragmatic eventration complicated by gastric volvulus with perforation

    OpenAIRE

    Gupta, V; Chandra, A; Gupta, P

    2012-01-01

    Eventration of the diaphragm with gastric volvulus is uncommon. Gastric perforation in these cases is rare and usually associated with acute gastric volvulus with strangulation. We describe a case of diaphragmatic eventration with chronic gastric volvulus with gastric perforation without strangulation in an elderly man.

  10. 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.

  11. Preoperative factors influencing mortality and morbidity in peptic ulcer perforation.

    Science.gov (United States)

    Sivaram, P; Sreekumar, A

    2018-04-01

    Perforated peptic ulcer is one of the most common surgical emergencies worldwide. With the improvement in medical therapy for peptic ulcers, the number of elective surgical procedures has come down. However, the incidence of perforated peptic ulcer is still increasing and remains as a substantial health problem with significant postoperative morbidity and mortality. This study aimed to find out the association between various preoperative and intraoperative factors with the postoperative mortality and morbidity in patients operated for peptic ulcer perforation. This prospective observational study had a time based sample of 101 perforation peritonitis cases admitted to the surgical wards of a tertiary care center from February 2015 to January 2016 who underwent laparotomy, diagnosed to have peptic ulcer perforation and underwent simple closure with an omental patch. Data regarding age, gender, presenting complaints, time elapsed from the onset of symptoms to surgery, physical examination findings, comorbid diseases, laboratory and imaging findings, intraoperative findings, length of hospital stay, postoperative morbidity, and mortality were recorded and analyzed. Female gender, older age group, perforation surgery interval more than 36 h, and size of perforation more than 1 cm 2 were found to be significant factors influencing postoperative mortality and morbidity. Postoperative morbidity was also associated with comorbid diseases. Abnormal renal function on presentation was identified as an additional risk factor for postoperative morbidity and longer hospital stay. An understanding of these factors, identification of patients at risk and early intervention can help in reducing the postoperative morbidity and mortality in peptic ulcer perforation.

  12. Jejunal Diverticular Perforation due to Enterolith

    Directory of Open Access Journals (Sweden)

    Ronaldo Nonose

    2011-08-01

    Full Text Available Jejunal diverticulosis is a rare entity with variable clinical and anatomical presentations. Although there is no consensus on the management of asymptomatic jejunal diverticular disease, some complications are potentially life-threatening and require early surgical treatment. Small bowel perforation secondary to jejunal diverticulitis by enteroliths is rare. The aim of this study was to report a case of small intestinal perforation caused by a large jejunal enterolith. An 86-year-old woman was admitted with signs of diffuse peritonitis. After initial fluid recovery the patient underwent emergency laparotomy. The surgery showed that she had small bowel diverticular disease, mainly localized in the proximal jejunum. The peritonitis was due to intestinal perforation caused by an enterolith 12 cm in length, localized inside one of these diverticula. The intestinal segment containing the perforated diverticulum with the enterolith was removed and an end-to-end anastomosis was done to reconstruct the intestinal transit. The patient recovered well and was discharged from hospital on the 5th postoperative day. There were no signs of abdominal pain 1 year after the surgical procedure. Although jejunal diverticular disease with its complications, such as formation of enteroliths, is difficult to suspect in patients with peritonitis, it should be considered as a possible source of abdominal infection in the elderly patient when more common diagnoses have been excluded.

  13. Sonographic templates of newborn perforator stroke.

    Science.gov (United States)

    Abels, Lyanne; Lequin, Maarten; Govaert, Paul

    2006-07-01

    Many paediatric strokes occur in the perinatal period. Improvement in neuroimaging has increased detection in newborns with neurological symptoms. To define sonographic templates of neonatal stroke in the territory of perforators of the anterior choroidal artery (AChA) and the anterior (ACA), middle (MCA) and posterior (PCA) cerebral arteries. In 24 neonates with perforator stroke, we retrospectively studied antenatal and perinatal events. Brain sonography was performed with an 8.5-MHz probe. Only hyperechoic lesions in the thalamus and/or striatum and/or centrum semiovale were included. MRI was obtained using a 1.5-T machine. We detected 28 perforator strokes in 24 infants (6 preterm): 5 MCA medial striate, 8 MCA lateral striate, 3 MCA centrum semiovale, 4 ACA Heubner's, 5 PCA thalamic arteries, 1 AChA, and 2 hypothalamic perforators. We attributed clinical seizures to stroke in two infants only. Catheter-related embolism (certain in three, possible in six others) and birth trauma (two) were probable causes. Specific conditions were found in six others. Only one infant (in nine evaluated) had an increased prothrombotic risk (fII mutation). In describing the lesions, we focused on the templates of infarction as seen in a parasagittal US sweep. Infarcts were confirmed by MRI in 21 patients. Our study showed that infarct topography can be evaluated reliably with brain sonography. This is important given the asymptomatic character of most lesions.

  14. Sen perforation af tyndtarm efter laparoskopisk gastrisk bypass

    DEFF Research Database (Denmark)

    Spanager, Lene; Sigild, Ulf Henrik; Neuenschwander, Anders Ulrich

    2010-01-01

    We present two cases in which the patients were admitted to a local hospital with acute abdominal pain four or five months after having undergone laparoscopic gastric bypass. In both cases, operation revealed a perforation of the small bowel close to the distal anastomosis. In the first case......, a massive constipation of the small bowel was most likely a contributing factor. In the second case, the cause was a kink of the entero-entero anastomosis leading to obstruction and finally perforation of the biliary limp. Late perforations are among the rarely reported complications associated with gastric...

  15. Perforated pyloroduodenal peptic ulcer and sonography.

    Science.gov (United States)

    Kuzmich, Siarhei; Harvey, Chris J; Fascia, Daniel T M; Kuzmich, Tatsiana; Neriman, Deena; Basit, Rizwan; Tan, Kai Lee

    2012-11-01

    The purpose of this article is to illustrate the spectrum of sonographic findings in perforated pyloroduodenal peptic ulcer and discuss the potential role of sonography in the diagnosis. Although sonography is not the first-line investigation of choice in suspected perforated peptic ulcer, understanding of the characteristic appearances seen during general abdominal sonography may aid the reader in the diagnosis of this important and sometimes overlooked cause of nonspecific abdominal pain. This may shorten time to the diagnosis and ultimate surgical management.

  16. Spontaneous Uterine Perforation due to Pyometra Presenting as Acute Abdomen

    Directory of Open Access Journals (Sweden)

    Loabat Geranpayeh

    2006-01-01

    Full Text Available Spontaneous perforation of the uterus is rare, its incidence being about 0.01%–0.05%. We report a rare case of diffuse peritonitis caused by spontaneously perforated pyometra. A 63-year-old woman with severe abdominal pain was admitted to our hospital. Laparotomy was performed because of the suspicion of gastrointestinal perforation with generalized peritonitis. At laparotomy, about 900 mL of pus was found in the peritoneal cavity. There were no abnormal findings in the alimentary tract, liver, or gallbladder. A total abdominal hysterectomy with bilateral salpingo-oophorectomy was performed. Pathological investigation of the surgical specimen revealed endometritis and myometritis of the uterus; but there was no evidence of malignancy, and the cervical canal was patent. Although spontaneously perforated pyometra is rare, a perforated pyometra should therefore also be considered when elderly women present with acute abdominal pain.

  17. Risk of surgical glove perforation in oral and maxillofacial surgery.

    Science.gov (United States)

    Kuroyanagi, N; Nagao, T; Sakuma, H; Miyachi, H; Ochiai, S; Kimura, Y; Fukano, H; Shimozato, K

    2012-08-01

    Oral and maxillofacial surgery, which involves several sharp instruments and fixation materials, is consistently at a high risk for cross-contamination due to perforated gloves, but it is unclear how often such perforations occur. This study aimed to address this issue. The frequency of the perforation of surgical gloves (n=1436) in 150 oral and maxillofacial surgeries including orthognathic surgery (n=45) was assessed by the hydroinsufflation technique. Orthognathic surgery had the highest perforation rate in at least 1 glove in 1 operation (91.1%), followed by cleft lip and palate surgery (55.0%), excision of oral soft tumour (54.5%) and dental implantation (50.0%). The perforation rate in scrub nurses was 63.4%, followed by 44.4% in surgeons and first assistants, and 16.3% in second assistants. The odds ratio for the perforation rate in orthognathic surgery versus other surgeries was 16.0 (95% confidence interval: 5.3-48.0). The protection rate offered by double gloving in orthognathic surgery was 95.2%. These results suggest that, regardless of the surgical duration and blood loss in all fields of surgery, orthognathic surgery must be categorized in the highest risk group for glove perforation, following gynaecological and open lung surgery, due to the involvement of sharp objects. Copyright © 2012 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  18. Perforated peptic ulcer associated with abdominal compartment syndrome.

    Science.gov (United States)

    Lynn, Jiun-Jen; Weng, Yi-Ming; Weng, Chia-Sui

    2008-11-01

    Abdominal compartment syndrome (ACS) is defined as an increased intra-abdominal pressure with adverse physiologic consequences. Abdominal compartment syndrome caused by perforated peptic ulcer is rare owing to early diagnosis and management. Delayed recognition of perforated peptic ulcer with pneumoperitoneum, bowel distension, and decreased abdominal wall compliance can make up a vicious circle and lead to ACS. We report a case of perforated peptic ulcer associated with ACS. A 74-year-old man with old stroke and dementia history was found to have distended abdomen, edema of bilateral legs, and cyanosis. Laboratory tests revealed deterioration of liver and kidney function. Abdominal compartment syndrome was suspected, and image study was arranged to find the cause. The study showed pneumoperitoneum, contrast stasis in heart with decreased caliber of vessels below the abdominal aortic level, and diffuse lymphedema at the abdominal walls. Emergent laparotomy was performed. Perforated peptic ulcer was noted and the gastrorrhaphy was done. The symptoms, and liver and kidney function improved right after emergent operation.

  19. Perforated peptic ulcer in an infant.

    Science.gov (United States)

    Feng, C Y; Hsu, W M; Chen, Y

    2001-02-01

    We describe a case of perforated peptic ulcer (PPU) in a 9-month-old boy. Abdominal distension was the first clinical sign of PPU. Before he developed abdominal distension, the patient had suffered from an upper respiratory tract infection with fever for about 2 weeks, which was treated intermittently with ibuprofen. A plain abdominal radiograph revealed pneumoperitoneum with a football sign. At laparotomy, a 0.8-cm perforated hole was found over the prepyloric area. Simple closure with omental patching was performed after debridement of the perforation. Pathologic examination showed chronic peptic ulcer with Helicobacter pylori infection. The postoperative course and outcome were satisfactory. The stress of underlying disease, use of ibuprofen, blood type (A), and H. pylori infection might have contributed to the development of PPU in this patient. PPU in infancy is rare and has a high mortality rate; early recognition and prompt surgical intervention are key to successful management.

  20. Posterior fossa reconstruction using titanium plate for the treatment of cerebellar ptosis after decompression for Chiari malformation.

    Science.gov (United States)

    Udani, Vikram; Holly, Langston T; Chow, Daniel; Batzdorf, Ulrich

    2014-01-01

    We describe our use of a perforated titanium plate to perform a partial posterior fossa cranioplasty in the treatment of cerebellar ptosis and dural ectasia after posterior fossa decompression (PFD). Twelve patients who had undergone PFD underwent posterior fossa reconstruction using a titanium plate. Symptoms were related to either descent of the cerebellum into the decompression or to dural ectasia into the craniectomy defect. Twelve patients who had undergone large suboccipital craniectomies and who presented with persistent headaches and some with neurological symptoms related to syringomyelia, underwent reoperation with placement of a small titanium plate. Ten of 12 patients showed symptomatic improvement after reoperation. Placement of a titanium plate appears to be an effective method of treatment of cerebellar ptosis and dural ectasia after PFD for Chiari malformation. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. A case report of esophageal perforation: Complication of nasogastric tube placement

    Science.gov (United States)

    Isik, Arda; Firat, Deniz; Peker, Kemal; Sayar, Ilyas; Idiz, Oguz; Soytürk, Mehmet

    2014-01-01

    Patient: Male, 70 Final Diagnosis: Esophageal perforation Symptoms: Abdominal pain • nausea • vomiting Medication: — Clinical Procedure: — Specialty: Surgery Objective: Unusual clinical course Background: Esophageal perforation is a well-defined and severe clinical condition. There are several etiologies of esophagus perforation. Case Report: We report the case of a 70-year-old Caucasian man who underwent an emergency cholecystectomy due to acute cholecystitis. Two days after surgery, his condition deteriorated. Thorax computerized tomography revealed an esophageal perforation. Conclusions: Esophageal perforation due to nasogastric application is relatively rare but the consequences are potentially serious. The anatomy of the upper gastrointestinal system should be understood by all healthcare professionals involved in the treatment. PMID:24803977

  2. Perforate on CHO cell membranes induced by electromagnetic ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-06-17

    Jun 17, 2009 ... Key words: Electromagnetic pulse (EMP), atomic force microscope, CHO cell, cell membrane. INTRODUCTION .... of perforation ranges from 390 to 660 nm and the depth is. 392.95 nm. ... cell membrane perforations increased when both the field intensity and ..... Melatonin and a spin-trap compound block.

  3. Perforated appendicitis: Risk factors and outcomes of management ...

    African Journals Online (AJOL)

    The case files of patients with perforated appendicitis were analysed in relation to age, sex, clinical presentation, management and outcome of management. The aim was to detect the main factors that contributed to the perforation of the appendix in these patients and assess the effectiveness of the treatment offered.

  4. Color Doppler Ultrasonography-Targeted Perforator Mapping and Angiosome-Based Flap Reconstruction

    DEFF Research Database (Denmark)

    Gunnarsson, Gudjon Leifur; Tei, Troels; Thomsen, Jørn Bo

    2016-01-01

    Knowledge about perforators and angiosomes has inspired new and innovative flap designs for reconstruction of defects throughout the body. The purpose of this article is to share our experience using color Doppler ultrasonography (CDU)-targeted perforator mapping and angiosome-based flap reconstr......Knowledge about perforators and angiosomes has inspired new and innovative flap designs for reconstruction of defects throughout the body. The purpose of this article is to share our experience using color Doppler ultrasonography (CDU)-targeted perforator mapping and angiosome-based flap...

  5. Optimizing time management after perforation by colonoscopy results in better outcome for the patients.

    Science.gov (United States)

    Rumstadt, Bernhard; Schilling, Dieter

    2008-01-01

    Perforation during colonoscopy is a rare but severe complication. The aim of this study was to assess the time management and laparoscopic therapy of this complication and to evaluate patient outcomes. A retrospective analysis was done on 15 patients operated for a perforation from colonoscopy between January 2000 and December 2006. Three perforations occurred during diagnostic and 12 perforations during interventional colonoscopy. Two perforations occurred as transmural thermal injury to the colon wall. Peritonitis was found in 4 cases and significantly correlated with the mean time between perforation and operation. Twelve perforations were oversewn laparoscopically and 3 perforations were oversewn by laparotomy. After laparoscopic treatment, hospital stay was significantly shorter than after laparotomy. One patient had a postoperative wound infection, mortality was 0%. Laparoscopic oversewing is a safe and effective method in the treatment of perforation from colonoscopy. Optimizing the time range between perforation and laparoscopic therapy results in a better outcome for the patients.

  6. Bladder perforations in children

    African Journals Online (AJOL)

    2014-11-20

    Nov 20, 2014 ... Mean recovery time for patients was 15 days. ... fracture.[1,2] Isolated bladder perforations are rare, and they .... PA, perineal injury, pelvic fracture. Trauma .... Lower genitourinary injury and pelvic fractures in pediatric patients.

  7. Traumatic oesophageal perforation due to haematoma

    DEFF Research Database (Denmark)

    Grønhøj Larsen, Christian; Brandt, Bodil

    2014-01-01

    . Three explanations postulated to be the cause for late perforation which might be due to esophageal wall ischemia from pressure built up between the hematoma, azygos vein and the lower part of thoracic trachea; or could be an immediate rupture walled-off until the patient became symptomatic......; or the intramural hematoma gradually lysed and causing late perforation. CONCLUSION: Although extremely rare, an oesophageal haematoma and late complications must be considered in patients on anti-coagulant therapy following blunt thoracic trauma and complaining only of chest pain....

  8. Influence of use of ultrasound on metallographic structure of plated pieces by welding in ultrasonic field

    Directory of Open Access Journals (Sweden)

    Gh. Amza

    2015-07-01

    Full Text Available To optimize the plating process is necessary to know the behavior of surfaces plated during the exploitation and in particular susceptibility to cracking, the formation of cracks from the inside to outside or reverse, embrittlement in the heat affected zone. Research has been realized considering several samples plated by welding without ultrasonic activation and with ultrasonic activation, and these samples were made of AISI 4130 steel, and as filler material was used Inconel 625 Fe developed as electrode wire ø 1,2 / mm. The plating process was realized by a WIG welding process in Ar100 /% environment with non-consumable tungsten electrode, in two versions, respectively with and without the use of ultrasonic energy. Four pieces played by welding there were analyzed the metallographies structure in the base material, the deposited material and the material from the heat affected zone.

  9. Perforation of the Esophagus Secondary to Insertion of Covered Wallstent Endoprostheses

    International Nuclear Information System (INIS)

    Farrugia, Mark; Morgan, Robert A.; Latham, Jennifer A.; Glynos, Michael; Mason, Robert C.; Adam, Andreas

    1997-01-01

    Perforation of the esophagus is a very rare complication of metallic esophageal stent insertion. Two cases are presented in which esophageal perforations were caused by the sharp ends of metallic stents impinging on the esophageal wall. In retrospect, both perforations might have been prevented by additional stent insertion

  10. High counting rate resistive-plate chamber

    International Nuclear Information System (INIS)

    Peskov, V.; Anderson, D.F.; Kwan, S.

    1993-05-01

    Parallel-plate avalanche chambers (PPAC) are widely used in physics experiments because they are fast ( 5 counts/mm 2 . A resistive-plate chamber (RPC) is similar to the PPAC in construction except that one or both of the electrodes are made from high resistivity (≥10 10 Ω·cm) materials. In practice RPCs are usually used in the spark mode. Resistive electrodes are charged by sparks, locally reducing the actual electric field in the gap. The size of the charged surface is about 10 mm 2 , leaving the rest of the detector unaffected. Therefore, the rate capability of such detectors in the spark mode is considerably higher than conventional spark counters. Among the different glasses tested the best results were obtained with electron type conductive glasses, which obey Ohm's law. Most of the work with such glasses was done with high pressure parallel-plate chambers (10 atm) for time-of-flight measurements. Resistive glasses have been expensive and produced only in small quantities. Now resistive glasses are commercially available, although they are still expensive in small scale production. From the positive experience of different groups working with the resistive glasses, it was decided to review the old idea to use this glass for the RPC. This work has investigated the possibility of using the RPC at 1 atm and in the avalanche mode. This has several advantages: simplicity of construction, high rate capability, low voltage operation, and the ability to work with non-flammable gases

  11. The US findings of acute nonperforated and perforated appendicitis in children

    International Nuclear Information System (INIS)

    Bae, Jun Gi; Lee, Young Seok; Jung, Yoon Ho; Kim, Ji Hye; Lee, Woon Ki; Lee, Tae Hoon

    1996-01-01

    To analyse and interpret different sonographic findings in acute nonperforated and appendicitis. In 46 cases of acute appendicitis in children(26 girls, 20 boys) proven by surgery, sonographic findings were reviewed retrospectively. The findings of nonperforated and perforated appendicitis were analysed, focusing on the size, shape and echogenicity of the appendix, echo patterns of periappendiceal abscesses, mesenteric lymphadenopathy, and the prevalence of appendicolith. A noncompressible distended appendix was present in 18 of 21 patients with nonperforated appendicitis and in 13 of 25 patients with perforation. In 18 patients with nonperforated appendicitis, the average diameter of distended appendix was 8.6 mm ; target appearance was noted in 16 patients and loss of echogenic submucosa in two. In 13 patients with perforated appendicitis, the average diameter of appendix was 9.1 mm ; target appearance was noted in four patients and loss of echogenic submucosa in nine. Periappendiceal abscesses were present in 21 of 25 cases of perforated appendicitis, and the echogenicity of abscesses was mixed in 12 patients, hypoechogenic in eight, and hyperechogenic in one. Mesenteric lymphadenopathy was present in two of 21 patients with nonperforated appendicitis and in four of 25 with perforation. Appendicolith was detected on sonography in three of 25 patients with perforated appendicitis, but was found in seven patients during surgery. One patients with perforated appendicitis also had right side hydronephrosis. Sonographically false-negative results were obtained in six cases. A sonographic examination was useful to differenciate perforated and nonperforated appendicitis in children. Loss of echogenic submucosa in the distended appendix and periappendiceal abscess formation were important findings in diagnosis of perforated appendicitis

  12. Esophageal perforation during or after conformal radiotherapy for esophageal carcinoma

    International Nuclear Information System (INIS)

    Chen Haiyan; Ma Xiumei; Ye Ming; Hou Yanli; Xie Huaying; Bai Yongrui

    2014-01-01

    The aim of this study was to analyze the risk factors and prognosis for patients with esophageal perforation occurring during or after radiotherapy for esophageal carcinoma. We retrospectively analyzed 322 patients with esophageal carcinoma. These patients received radiotherapy for unresectable esophageal tumors, residual tumors after operation, or local recurrence. Of these, 12 had radiotherapy to the esophagus before being admitted, 68 patients had concurrent chemoradiotherapy (CRT), and 18 patients had esophageal perforation after RT (5.8%). Covered self-expandable metallic stents were placed in 11 patients. Two patients continued RT after stenting and control of infection; one of these suffered a new perforation, and the other had a massive hemorrhage. The median overall survival was 2 months (0-3 months) compared with 17 months in the non-perforation group. In univariate analysis, the Karnofsky performance status (KPS) being ≤ 70, age younger than 60, T4 stage, a second course of radiotherapy to the esophagus, extracapsular lymph nodes (LN) involving the esophagus, a total dose > 100 Gy (biologically effective dose -10 ), and CRT were risk factors for perforation. In multivariate analysis, age younger than 60, extracapsular LN involving the esophagus, T4 stage, and a second course of radiotherapy to the esophagus were risk factors. In conclusion, patients with T4 stage, extracapsular LN involving the esophagus, and those receiving a second course of RT should be given particular care to avoid perforation. The prognosis after perforation was poor. (author)

  13. Experimental study on behavior of RC panels covered with steel plates subjected to missile impact

    International Nuclear Information System (INIS)

    Jun Hashimoto; Katsuki Takiguchi; Koshiro Nishimura; Kazuyuki Matsuzawa; Mayuko Tsutsui; Yasuhiro Ohashi; Isao Kojima; Haruhiko Torita

    2005-01-01

    This paper describes an experimental study on the behavior of concrete panels with steel plate subjected to missile impact. Two tests were carried out, divided in accordance with the types of projectile, non-deformable and deformable. In all, 40 specimens of 750 mm square were prepared. The panel specimen was suspended vertically by two steel wire ropes to allow free movement after projectile impact, and was subjected to a projectile. As a result, it is confirmed that a RC panel with steel plate on its back side has higher impact resistance performance than a RC panel and that thickness of concrete panel, thickness of steel plate and the impact velocity of the projectile have a great effect on the failure modes of steel concrete panels. Moreover, based on the experimental results, the quantitative evaluation method for impact resistance performance of RC panels covered with steel plates is examined. The formula for perforation velocity of a half steel concrete panel, proposed in accordance with the bulging height, is effective to evaluate the impact resistance performance of RC panels with steel plates. (authors)

  14. A CLINICAL STUDY ON PATIENTS WITH DUODENAL ULCER PERFORATION

    Directory of Open Access Journals (Sweden)

    Kishore Babu

    2016-03-01

    Full Text Available INTRODUCTION Perforated duodenal ulcer, the most catastrophic complication was Associated with high mortality in the past due to late presentation of the patients, delay in surgery and lack of antibiotics. Various authors state that the incidence of peptic ulcer disease and perforation has been declining for the past 3 decades. Because of advances in the medical therapy of peptic ulcer with a wide range of drugs the management of peptic ulcer disease has been changing and the role of surgery has been declining. Perforation is usually seen in 3rd and 4th decades with a male preponderance and the epidemiological trend is not the same worldwide. Incidence is slightly declining in western countries. The present study has been done during the period between 2013 and 2014 in S. V. R. R. Government general hospital Tirupati. AIMS AND OBJECTIVES The aim of the present study is to analyze the probable factors for increase in incidence of duodenal ulcer perforation, with particular emphasis on assessment of impact of H2 receptor antagonists and Proton Pump inhibitors on the incidence of perforation. STUDY SETTING S. V. Medical College, Department of General Surgery, Tirupati. STUDY PERIOD Patients attending S. V. Medical College, Department of General Surgery with perforation during the period from November 2013 to October 2014. INCLUSION CRITERIA Patients between age group of more than 14 years presenting with pain abdomen and who are diagnosed to have peritonitis due to duodenal ulcer perforation. EXCLUSION CRITERIA Patients with peritonitis due causes other than duodenal ulcer. STUDY METHOD Prospective Observational study among the selected patients. Total numbers of peptic ulcer cases that were admitted in this hospital and treated either medically or surgically were noted. The details of their clinical history and findings, investigation reports, operative findings, post-operative complications were recorded. Simple closure was performed for all the

  15. Jejunal perforation by swallowed ibuprofen caplet | Njoku | Nigerian ...

    African Journals Online (AJOL)

    We present a case of jejunal perforation caused by an unusual foreign body, an ibuprofen caplet in its blister packing believed to be the first of its kind, perforation of the intestine caused by an ingested medication. The patient eventually developed an enterocutaneous fistula through the weak wall of a preexisting incisional ...

  16. Cause rare d'une perforation de la cloison nasale

    Science.gov (United States)

    Jahidi, Ali; Hemmaoui, Bouchaïb; Itoua, Wulfran Rosaire; Errami, Noureddine; Benariba, Fouad

    2014-01-01

    Les perforations de la cloison nasale constituent une pathologie fréquente en ORL. Leurs causes sont multiples et restent dominées par les traumatismes chirurgicaux. Les étiologies infectieuses et notamment la tuberculose sont rares. Nous présentons le cas d'une patiente ayant bénéficié d'une méatotomie bilatérale et chez laquelle une perforation de la cloison nasale a été découverte lors d'un examen systématique à un an de son intervention. D'abord considérée comme une complication de la chirurgie, la biopsie des berges de la perforation a permis de déterminer son origine tuberculeuse. La présentation clinique des perforations de la cloison nasale n'est pas spécifique. Elles sont souvent asymptomatiques et de découverte fortuite. Les traumatismes notamment chirurgicaux sont le plus siuvent en cause. L′orogine tuberculeuse resta très rare. Le diagnostic de certitude de tuberculose repose sur la biopsie des berges de cette perforation. Le but de ce travail est de mettre en avant l'intérêt de la biopsie dans le diagnostic de la tuberculose de la cloison nasale. Cette biopsie doit être systématique même en cas d'antécédents de chirurgie endonasale qui est le plus souvent en cause dans les perforations de la cloison nasale. PMID:24932334

  17. Reconstruction of pressure sores with perforator-based propeller flaps.

    Science.gov (United States)

    Jakubietz, Rafael G; Jakubietz, Danni F; Zahn, Robert; Schmidt, Karsten; Meffert, Rainer H; Jakubietz, Michael G

    2011-03-01

    Perforator flaps have been successfully used for reconstruction of pressure sores. Although V-Y advancement flaps approximate debrided wound edges, perforator-based propeller flaps allow rotation of healthy tissue into the defect. Perforator-based propeller flaps were planned in 13 patients. Seven pressure sores were over the sacrum, five over the ischial tuberosity, and one on the tip of the scapula. Three patients were paraplegic, six were bedridden, and five were ambulatory. In three patients, no perforators were found. In 10 patients, propeller flaps were transferred. In two patients, total flap necrosis occurred, which was reconstructed with local advancement flaps. In two cases, a wound dehiscence occurred and had to be revised. One hematoma required evacuation. No further complications were noted. No recurrence at the flap site occurred. Local perforator flaps allow closure of pressure sores without harvesting muscle. The propeller version has the added benefit of transferring tissue from a distant site, avoiding reapproximation of original wound edges. Twisting of the pedicle may cause torsion and venous obstruction. This can be avoided by dissecting a pedicle of at least 3 cm. Propeller flaps are a safe option for soft tissue reconstruction of pressure sores. © Thieme Medical Publishers.

  18. Small bowel perforation due to fish bone: A case report

    Directory of Open Access Journals (Sweden)

    Huseyin Pulat

    2015-09-01

    Full Text Available Accidental ingestion of foreign bodies are a common condition in clinical practice. However, small bowel perforation which dues to ingestion foreign bodies has been rarely seen. In this article, we report a case of small bowel perforation which dues to ingestion foreign body. A 80-year-old female patient, presenting with complaints of acute abdomen, was admitted to the emergency department. She denied abdominal pain, nausea and vomiting. The patient had tenderness and defense on the right lower quadrant. Contrast enhanced abdominal computed tomography has been used on the patient's diagnosis. This revealed small bowel perforation due to the ingestion of foreign body. The patient was operated emergency. A microperforation due to fish bone was detected on the terminal ileum. The patient underwent debridement and primary repair. The patient was discharged postoperative 7th day without problem. Bowel perforation due to the ingestion of foreign bodies should be considered in the differential diagnosis of acute abdomen. Keywords: Foreign body, Small intestine, Perforation

  19. An equivalent network representation of a clamped bimorph piezoelectric micromachined ultrasonic transducer with circular and annular electrodes using matrix manipulation techniques.

    Science.gov (United States)

    Sammoura, Firas; Smyth, Katherine; Kim, Sang-Gook

    2013-09-01

    An electric circuit model for a clamped circular bimorph piezoelectric micromachined ultrasonic transducer (pMUT) was developed for the first time. The pMUT consisted of two piezoelectric layers sandwiched between three thin electrodes. The top and bottom electrodes were separated into central and annular electrodes by a small gap. While the middle electrode was grounded, the central and annular electrodes were biased with two independent voltage sources. The strain mismatch between the piezoelectric layers caused the plate to vibrate and transmit a pressure wave, whereas the received echo generated electric charges resulting from plate deformation. The clamped pMUT plate was separated into a circular and an annular plate, and the respective electromechanical transformation matrices were derived. The force and velocity vectors were properly selected using Hamilton's principle and the necessary boundary conditions were invoked. The electromechanical transformation matrix for the clamped circular pMUT was deduced using simple matrix manipulation techniques. The pMUT performance under three biasing schemes was elaborated: 1) central electrode only, 2) central and annular electrodes with voltages of the same magnitude and polarity, and 3) central and annular electrodes with voltages of the same magnitude and opposite polarity. The circuit parameters of the pMUT were extracted for each biasing scheme, including the transformer ratio, the clamped electric impedance, and the open-circuit mechanical impedance. Each pMUT scheme was characterized under different acoustic loadings using the theoretically developed model, which was verified with finite element modeling (FEM) simulation. The electrode size was optimized to maximize the electromechanical transformer ratio. As such, the developed model could provide more insight into the design, optimization, and characterization of pMUTs and allow for performance comparison with their cMUT counterparts.

  20. Role of Spiral and Multislice Computed Tomography in the evaluation of traumatic and spontaneous oesophageal perforation. Our experience

    International Nuclear Information System (INIS)

    De Lutio di Castelguidone, Elisabetta; Pinto, Antonio; Merola, Stefanella; Stavolo, Ciro; Romano, Luigia

    2005-01-01

    Purpose: To assess the role of CT in the evaluation of traumatic and spontaneous oesophageal perforation. Materials and methods: From March 2001 to May 2003, we studied 12 patients (7 males and 5 females; age range: 25-66 years, mean age: 43.5 years) with suspected oesophageal perforation due to motor-vehicle accidents (4 cases), stab wound (one case), post-intubation (2 cases), foreign body ingestion (2 cases) and spontaneous (3 cases). Five patients underwent standard chest and cervical radiography; two patients with suspected foreign body ingestion also underwent a gastrografin swallow study; all of the 12 patients underwent CT of the neck, chest and abdomen before and after intravenous, and in four cases oral, administration of contrast material. Results: In 5 patients with cervical, thoracic and abdominal trauma, the CT examination showed the presence of pleuroparenchymal injury (pneumothorax, pleural effusion and subcutaneous emphysema) as well as findings suggestive of oesophageal perforation: peri-oesophageal air (5 cases), peri-oesophageal fluid (4 cases), oesophageal wall thickening (3 cases), oesophageal wall laceration (2 cases) with abnormal course of the nasogastric tube in one of them and extraluminal extravasation of oral contrast material (2 cases). In two patients with post-intubation complications, CT showed the presence of a small peri-oesophageal fluid collection containing small gas bubbles in one case, and a gross peri-oesophageal abscess-like collection in the second case. In the 2 patients with foreign body ingestion, the plain radiography associated with CT showed the presence of a thin metal object in the cervical region (fragment of a dental plate) and a small extraluminal extravasation of gastrografin in one case, whereas in the other case CT showed the presence of a foreign body (chicken bone) in the hypopharynx with oesophageal wall thickening and peri-oesophageal oedema. In the remaining three patients with suspected spontaneous

  1. Field tests of electric survey using capacitive electrodes; Kyapashita denkyoku wo mochiita denki tansarei

    Energy Technology Data Exchange (ETDEWEB)

    Miyazaki, I; Iseki, S; Kobayashi, T [OYO Corp., Tokyo (Japan)

    1997-10-22

    This paper describes field test results of electric survey using capacitive electrodes. When two metal plates are approached without contacting with the ground and voltage is applied between the plates, current flows in the ground. The metal plates and the ground work as a capacitor. Charges are stored between them. These metal plates having insulation with the ground are called capacitive electrodes. When ac voltage is applied between a pair of capacitors, current flows continuously in the ground without saturating the capacitors. Resistivity of the ground can be determined by measuring the level of current flowing in the ground and the level of potential. As a result of the field tests, it was found that the present method is superior to the conventional method in around ten times. However, to obtain high quality data, water spraying, reduced towing speed at the low resistivity ground such as clay and soil, and grass mowing are required. 3 refs., 5 figs., 1 tab.

  2. Perforated Duodenal Ulcer in a Young Child: An Uncommon Condition

    Directory of Open Access Journals (Sweden)

    Rohit Prasad Yadav

    2009-04-01

    Full Text Available Duodenal ulcer is an uncommonly diagnosed entity in children. H. pyloriinfection, blood group ‘O’ or secondary to medications like non steroidal anti-infl ammatory drugs (NSAID and corticosteroids or physiological stress in burns, head injury and mucosal ischemia are implicated as risk factors for their causation. The diagnosis is usually overlooked because of vague and variable symptoms and remote index of suspicion accounted for their low incidence in children. Undiagnosed or mistreated perforations may carry high morbidity and mortality. We report a successfully treated 41/2 year old male child who presented with features of perforation peritonitis and was incidentally found to have a perforated duodenal ulcer. Key Words: duodenal ulcer, laparotomy, perforation

  3. Biharmonic split ring resonator metamaterial: Artificially dispersive effective density in thin periodically perforated plates

    KAUST Repository

    Farhat, Mohamed

    2014-08-01

    We present in this paper a theoretical and numerical analysis of bending waves localized on the boundary of a platonic crystal whose building blocks are Split Ring Resonators (SRR). We first derive the homogenized parameters of the structured plate using a three-scale asymptotic expansion in the linearized biharmonic equation. In the limit when the wavelength of the bending wave is much larger than the typical heterogeneity size of the platonic crystal, we show that it behaves as an artificial plate with an anisotropic effective Young modulus and a dispersive effective mass density. We then analyze dispersion diagrams associated with bending waves propagating within an infinite array of SRR, for which eigen-solutions are sought in the form of Floquet-Bloch waves. We finally demonstrate that this structure displays the hallmarks of All-Angle Negative Refraction (AANR) and it leads to superlensing and ultrarefraction effects, interpreted thanks to our homogenization model as a consequence of negative and vanishing effective density, respectively. © EPLA, 2014.

  4. Biharmonic split ring resonator metamaterial: Artificially dispersive effective density in thin periodically perforated plates

    KAUST Repository

    Farhat, Mohamed; Enoch, Stefan; Guenneau, Sé bastien

    2014-01-01

    We present in this paper a theoretical and numerical analysis of bending waves localized on the boundary of a platonic crystal whose building blocks are Split Ring Resonators (SRR). We first derive the homogenized parameters of the structured plate using a three-scale asymptotic expansion in the linearized biharmonic equation. In the limit when the wavelength of the bending wave is much larger than the typical heterogeneity size of the platonic crystal, we show that it behaves as an artificial plate with an anisotropic effective Young modulus and a dispersive effective mass density. We then analyze dispersion diagrams associated with bending waves propagating within an infinite array of SRR, for which eigen-solutions are sought in the form of Floquet-Bloch waves. We finally demonstrate that this structure displays the hallmarks of All-Angle Negative Refraction (AANR) and it leads to superlensing and ultrarefraction effects, interpreted thanks to our homogenization model as a consequence of negative and vanishing effective density, respectively. © EPLA, 2014.

  5. Perforated choledochal cyst in a Jehovah's Witness patient.

    Science.gov (United States)

    Jones, V S; Philip, C

    2007-07-01

    Perforation is a rare presentation of a choledochal cyst. The case reported is a 9-month-old female baby with a perforated choledochal cyst. Being a Jehovah's Witness, blood tranfusion was refused. Apart from highlighting this social dilemma, the suitability of a cystojejunostomy as a temporary measure in the above scenario is evaluated and discussed.

  6. Gastric Perforation by Ingested Rabbit Bone Fragment

    Directory of Open Access Journals (Sweden)

    Giulio Gambaracci

    2016-04-01

    Full Text Available The majority of accidentally ingested foreign bodies is excreted from the gastrointestinal (GI tract without any complications. Sometimes sharp foreign bodies – like chicken and fish bones – can lead to intestinal perforation and may present insidiously with a wide range of symptoms and, consequently, different diagnoses. We report the case of a 59-year-old woman presenting with fever and a 1-month history of vague abdominal pain. Computed tomography (CT showed the presence of a hyperdense linear image close to the gastric antrum surrounded by a fluid collection and free peritoneal air. At laparotomy, a 4-cm rabbit bone fragment covered in inflamed tissue was detected next to a gastric wall perforation. Rabbit bone fragment ingestion, even if rarely reported, should not be underestimated as a possible cause of GI tract perforation.

  7. A rare manifestation of perforated diverticulitis: parastomal subcutaneous abscess.

    NARCIS (Netherlands)

    Peters, J.H.; Bleichrodt, R.P.; Goor, H. van

    2003-01-01

    Perforation is a serious complication of diverticular disease. The sigmoid is the main affected anatomic site of perforated diverticulitis and sigmoid resection followed either by Hartmann procedure or primary anastomosis are the standard surgical approaches. Surgery, however, does not cure

  8. Delayed Diagnosis of Pharyngeal Perforation following Exploding Tyre Blast Barotrauma

    Directory of Open Access Journals (Sweden)

    Samantha M. Field

    2014-01-01

    Full Text Available Introduction. Pharyngoesophageal perforation secondary to barotrauma is a rare phenomenon that can have serious complications if identified late. It is challenging to detect due to nonspecific symptoms. We present a case in which detection proved difficult leading to delayed diagnosis. Case Report. A 27-year-old mechanic presented with haemoptysis, dysphonia, and odynophagia after a car tyre exploded in his face. Flexible nasoendoscopy (FNE revealed blood in the pharynx, thought to represent mucosal haemorrhage. Initial treatment consisted of IV dexamethasone and antibiotics. After 3 days, odynophagia persisted prompting a CT scan. This revealed a defect in the posterior hypopharynx and surgical emphysema in the deep neck tissues. Contrast swallow confirmed posterior hypopharyngeal leak. NG feeding was commenced until repeated contrast swallow confirmed resolution of the defect. Discussion. Prompt nonsurgical management of pharyngoesophageal perforation has good outcomes but untreated perforation can have serious complications. FNE should be performed routinely, but only a contrast swallow can diagnose a functional perforation. Clinicians should have a high index of clinical suspicion when patients present with barotrauma and odynophagia. Patients should be kept nil by mouth until perforation has been excluded. Conclusion. When faced with cases of facial barotrauma, clinicians should have a low threshold for further imaging to exclude pharyngoesophageal perforation.

  9. Laparoscopic lavage for perforated diverticulitis with purulent peritonitis

    DEFF Research Database (Denmark)

    Thornell, Anders; Angenete, Eva; Bisgaard, Thue

    2016-01-01

    Background: Perforated diverticulitis with purulent peritonitis has traditionally been treated with open colon resection and stoma formation with risk for reoperations, morbidity, and mortality. Laparoscopic lavage alone has been suggested as definitive treatment. Objective: To compare laparoscopic...... lavage with open colon resection and colostomy (Hartmann procedure) for perforated diverticulitis with purulent peritonitis. Design: Randomized, controlled, multicenter, open-label trial. (ISRCTN registry number: ISRCTN82208287) Setting: 9 hospitals in Sweden and Denmark. Patients: Patients who have...... confirmed Hinchey grade III perforated diverticulitis with purulent peritonitis at diagnostic laparoscopy. Intervention: Randomization between laparoscopic lavage and the Hartmann procedure. Measurements: Primary outcome was the percentage of patients having 1 or more reoperations within 12 months. Key...

  10. Electrode-Skin contact impedance: In vivo measurements on an ovine model

    International Nuclear Information System (INIS)

    Nguyen, D T; Kosobrodov, R; Jin, C; McEwan, A; Barry, M A; Chik, W; Thiagalingam, A; Oh, T I

    2013-01-01

    The problem of electrical impedance between the skin and the electrode is an on-going challenge in bio-electronics. This is particularly true in the case of Electrical Impedance Tomography (EIT), which uses a large number of skin-contact electrodes and is very sensitive to noise. In the present article, contact impedance is measured and compared for a range of electrodes placed on the thorax of an ovine model. The study has been approved by the Westmead Hospital Animal Ethics Committee. The electrode models that were employed in the research are Ag/AgCl electrodes (E1), commonly used for ECG and EIT measurements in both humans and animal models, stainless steel crocodile clips (E2), typically used on animal models, and novel multi-point dry electrodes in two modifications: bronze plated (E3) and nickel plated (E4). Further, since the contact impedance is mostly attributed to the acellular outer layer of the skin, in our experiment, we attempted to study the effect of this layer by comparing the results when the skin is intact and when electrodes are introduced underneath the skin through small cuts. This boundary effect was assessed by comparison of measurements obtained during E2 skin surface contact, and sub-cutaneous contact (E5). Twelve gauge intradermal needles were also tested as an electrode (E6). The full impedance spectrum, from 500 Hz to 300 kHz, was recorded, analysed and compared. As expected, the contact impedance in the more invasive cases, i.e the electrodes under the skin, is significantly lower than in the non-invasive cases. At the frequency of 50 kHz which is commonly used in lung EIT acquisition, electrodes E3, E4 and E6 demonstrated contact impedance of less than 200 Ω, compared to more than 400 Ω measured for electrodes E1, E2 and E5. In conclusion, the novel multipoint electrodes proved to be best suited for EIT purposes, because they are non-invasive and have lower contact impedance than Ag/AgCl and crocodile clips, in both invasive and

  11. Transmural coil embolization—alternative technique for management of arterial perforation during subintimal angioplasty

    Directory of Open Access Journals (Sweden)

    Karthikeyan Damodharan

    2016-01-01

    Full Text Available Subintimal angioplasty of lower limb arterial occlusion carries a relatively higher risk of vessel perforation compared to transluminal angioplasty. Vessel perforation is a potentially life threatening complication which requires prompt recognition and management. They are usually managed by endovascular techniques such as low-pressure balloon tamponade, covered stents, and coil embolization of the ruptured artery. We describe a technique of treating vessel perforation following balloon angioplasty. Patient developed a large perforation of the proximal superficial femoral artery (SFA after balloon inflation during subintimal angioplasty of complete SFA occlusion. Following failure of balloon tamponade in sealing the perforation, we successfully treated it by deploying an embolization coil at the site of perforation through the vessel wall followed by balloon tamponade. Our technique could be a useful relatively inexpensive alternative treatment option in the management of vessel perforation compared to covered stents.

  12. External perforated Solar Screens for daylighting in residential desert buildings: Identification of minimum perforation percentages

    KAUST Repository

    Sherif, Ahmed

    2012-06-01

    The desert climate is endowed by clear sky conditions, providing an excellent opportunity for optimum utilization of natural light in daylighting building indoor spaces. However, the sunny conditions of the desert skies, in countries like Egypt and Saudi Arabia, result in the admittance of direct solar radiation, which leads to thermal discomfort and the incidence of undesired glare. One type of shading systems that is used to permit daylight while controlling solar penetration is " Solar Screens" Very little research work addressed different design aspects of external Solar Screens and their influence on daylighting performance, especially in desert conditions, although these screens proved their effectiveness in controlling solar radiation in traditional buildings throughout history.This paper reports on the outcomes of an investigation that studied the influence of perforation percentage of Solar Screens on daylighting performance in a typical residential living room of a building in a desert location. The objective was to identify minimum perforation percentage of screen openings that provides adequate illuminance levels in design-specific cases and all-year-round.Research work was divided into three stages. Stage one focused on the analysis of daylighting illuminance levels in specific dates and times, while the second stage was built on the results of the first stage, and addressed year round performance using Dynamic Daylight Performance Metrics (DDPMs). The third stage addressed the possibility of incidence of glare in specific cases where illuminance levels where found very high in some specific points during the analysis of first stage. The research examined the daylighting performance in an indoor space with a number of assumed fixed experimentation parameters that were chosen to represent the principal features of a typical residential living room located in a desert environment setting.Stage one experiments demonstrated that the screens fulfilled the

  13. Spectrum of perforation peritonitis in Pakistan: 300 cases Eastern experience

    OpenAIRE

    Ur-Rahman Shafiq; Malik Faiza; Afridi Shahida; Shamim Shahid; Samo Khursheed A

    2008-01-01

    Abstract Background Perforation peritonitis is the most common surgical emergency encountered by the surgeons all over the world as well in Pakistan. The spectrum of etiology of perforation peritonitis in tropical countries continues to differ from its western counter part. This study was conducted at Dow University of health sciences and Civil Hospital Karachi (DUHS & CHK) Pakistan, designed to highlight the spectrum of perforation peritonitis in the East and to improve its outcome. Methods ...

  14. CLINICAL STUDY OF APPENDICULAR PERFORATION IN A TERTIARY CARE HOSPITAL

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    Venkata Anantha Lakshmi Manabala

    2016-06-01

    Full Text Available INTRODUCTION Acute Appendicitis is the commonest abdominal surgical emergency in young adults all over the world. In early 1900s, Ochsner in Chicago and Sherren at the London Hospital were both advocates of conservative treatment in late cases. Appendicular perforation is a serious complication in view of the ensuing peritonitis with the consequent sequelae and morbidity. AIM To study the incidence, morbidity and sequelae of appendicular perforation. MATERIALS & METHODS This is a prospective study done in our hospital where 110 cases of peritonitis due to appendicular perforation were selected for our study. All the cases where peritonitis was due to appendicular perforation at laparotomy were included. The study period was from January 2014 to December 2015. The cases of peritonitis due to other causes like duodenal, gastric, enteric perforation were excluded. Patients with acute abdominal emergency with clinical diagnosis of peritonitis were examined carefully with detailed history and clinical examination. Necessary investigations were done and patients taken up for emergency surgery. CONCLUSIONS Acute Appendicitis is the commonest abdominal surgical emergency in young adults all over the world. Age incidence of appendicular perforation is maximum in the age group of 21–30 years. Next common age group is 31–40 yrs. Incidence is more in males. Male to female ratio is 2.4:1. Pain abdomen, vomiting, fever and anorexia were common symptoms in all the patients. Majority of the patients came late to the hospital accounting for the cause of perforation and subsequent mortality and morbidity.

  15. Influence of use of ultrasound on the mechanical properties of plated pieces by welding in ultrasonic field

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    Gh. Amza

    2015-07-01

    Full Text Available Plating by welding in an ultrasonic field represents a technological solution to increase resistance to corrosion and / or wear of pieces of the machinery industry. Research has been carried out for two types of parts, namely a piece of flange end type and bonnet type made of AISI 4130 steel, and as filler material for plating was used Inconel 625 Fe developed as electrode wire with a diameter of ø 1.2 / mm. The plating was done by depositing a single layer by welding in ultrasonic field, welding process in Ar 100/ % environment non-consumable tungsten electrode, WIG process, and when using ultrasonic activation it was used a longitudinal and a transverse wave with a frequency of 15 / kHz. For pieces plated by welding there have been made attempts of the hardness and tensile and bend shock.

  16. The research progress of acute small bowel perforation

    Directory of Open Access Journals (Sweden)

    Rudolf Schiessel

    2015-08-01

    Full Text Available This article reviews the various aetiologies of small bowel perforations and their management. In addition to the well-known aetiologies such as trauma, inflammation and circulatory disorders, several new causes of small bowel perforation have been described in recent years. The spectrum reaches from iatrogenic perforations during laparoscopic surgery or enteroscopies to drug-induced perforations with new anticancer agents. The management of small bowel perforations requires a concept consisting of the safe revision of the leaking bowel and the treatment of the peritonitis. Depending on the local situation and the condition of the patient, several treatment options are available. The surgical management of the bowel leak can range from a simple primary closure to a delayed restoration of bowel continuity. When the condition of the bowel or patient is frail, the risk of a failure of a closure or anastomosis is too high, and the exteriorization of the bowel defect as a primary measure is a safe option. The treatment of the peritonitis is also dependent on the condition of the patient and the local situation. Early stages of peritonitis can be treated by a simple peritoneal lavage, either performed by laparoscopy or laparotomy. Severe forms of peritonitis with multi-organ failure and an abdominal compartment syndrome need repeated peritoneal revisions. In such cases, the abdomen can only be closed temporarily. Different technical options are available in order to overcome the difficult care of these patients.

  17. Analysis of colonoscopic perforations at a local clinic and a tertiary hospital.

    Science.gov (United States)

    Sagawa, Toshihiko; Kakizaki, Satoru; Iizuka, Haruhisa; Onozato, Yasuhiro; Sohara, Naondo; Okamura, Shinichi; Mori, Masatomo

    2012-09-21

    To define the clinical characteristics, and to assess the management of colonoscopic complications at a local clinic. A retrospective review of the medical records was performed for the patients with iatrogenic colon perforations after endoscopy at a local clinic between April 2006 and December 2010. Data obtained from a tertiary hospital in the same region were also analyzed. The underlying conditions, clinical presentations, perforation locations, treatment types (operative or conservative) and outcome data for patients at the local clinic and the tertiary hospital were compared. A total of 10  826 colonoscopies, and 2625 therapeutic procedures were performed at a local clinic and 32  148 colonoscopies, and 7787 therapeutic procedures were performed at the tertiary hospital. The clinic had no perforations during diagnostic colonoscopy and 8 (0.3%) perforations were determined to be related to therapeutic procedures. The perforation rates in each therapeutic procedure were 0.06% (1/1609) in polypectomy, 0.2% (2/885) in endoscopic mucosal resection (EMR), and 3.8% (5/131) in endoscopic submucosal dissection (ESD). Perforation rates for ESD were significantly higher than those for polypectomy or EMR (P hospital. Six perforations occurred with therapeutic endoscopy (perforation rate, 0.08%; 1 per 1298 procedures). Perforation rates for specific procedure types were 0.02% (1 per 5500) for polypectomy, 0.17% (1 per 561) for EMR, 2.3% (1 per 43) for ESD in the tertiary hospital. There were no differences in the perforation rates for each therapeutic procedure between the clinic and the tertiary hospital. The incidence of iatrogenic perforation requiring surgical treatment was quite low in both the clinic and the tertiary hospital. No procedure-related mortalities occurred. Performing closure with endoscopic clipping reduced the C-reactive protein (CRP) titers. The mean maximum CRP titer was 2.9 ± 1.6 mg/dL with clipping and 9.7 ± 6.2 mg/dL without clipping

  18. Perforated peptic ulcer in southeastern Taiwan.

    Science.gov (United States)

    Li, Chin-Hsien; Chang, Wen-Hsiung; Shih, Shou-Chuan; Lin, Shee-Chan; Bair, Ming-Jong

    2010-09-01

    No studies focus on the population with perforated peptic ulcer in southeastern Taiwan. The present study aimed to assess the differences between the different races and the risk factors related to mortality and morbidity in postoperative patients in southeastern Taiwan. The medical records of 237 patients were reviewed retrospectively. The following factors were analyzed: patient profiles, coexisting illnesses, diagnostic method, fever, preoperative shock, clinical data at emergency room, delay operation, site of perforation, operative method, positive ascites culture, species of microbes in ascites culture, postoperative complications, death and the length of hospital stay. Aborigines were significantly different from non-aborigines in the ratio of female cases and in the habits of alcohol drinking and betel nut chewing. There were also four significantly different variables between them: fever, hemoglobin value, site of perforation and operative method. Total postoperative complication rate was 41.3% and 39 patients (16.6%) died. In multivariate analysis, age > or = 65 years, lipase > upper normal limit and preoperative shock were independent predictors of mortality. Significant risk factors associated with morbidity were NSAIDs use, creatinine > 1.5 mg/dL and preoperative shock. Aborigines were different from non-aborigines in several categories. In southeastern Taiwan, NSAIDs use, creatinine > 1.5 mg/dL and preoperative shock were independent risk factors of morbidity, and age > or = 65 years, lipase > upper normal limit and preoperative shock were independent risk factors of mortality in postoperative perforated peptic ulcer. Lipase > upper normal limit is needed for further research on the influence on mortality.

  19. Case report: Stercoral sigmoid colonic perforation with fecal peritonitis

    International Nuclear Information System (INIS)

    Sharma, Monika; Agrawal, Anjali

    2010-01-01

    Chronic constipation can lead to fecal impaction. It can also rarely lead to catastrophic complications like perforation, colonic obstruction, and fecal peritonitis. We report a rare case of stercoral sigmoid colonic perforation with fecal peritonitis and pneumoperitoneum, which was diagnosed on preoperative CT scan

  20. Generalized multiscale finite element methods for problems in perforated heterogeneous domains

    KAUST Repository

    Chung, Eric T.

    2015-06-08

    Complex processes in perforated domains occur in many real-world applications. These problems are typically characterized by physical processes in domains with multiple scales. Moreover, these problems are intrinsically multiscale and their discretizations can yield very large linear or nonlinear systems. In this paper, we investigate multiscale approaches that attempt to solve such problems on a coarse grid by constructing multiscale basis functions in each coarse grid, where the coarse grid can contain many perforations. In particular, we are interested in cases when there is no scale separation and the perforations can have different sizes. In this regard, we mention some earlier pioneering works, where the authors develop multiscale finite element methods. In our paper, we follow Generalized Multiscale Finite Element Method (GMsFEM) and develop a multiscale procedure where we identify multiscale basis functions in each coarse block using snapshot space and local spectral problems. We show that with a few basis functions in each coarse block, one can approximate the solution, where each coarse block can contain many small inclusions. We apply our general concept to (1) Laplace equation in perforated domains; (2) elasticity equation in perforated domains; and (3) Stokes equations in perforated domains. Numerical results are presented for these problems using two types of heterogeneous perforated domains. The analysis of the proposed methods will be presented elsewhere. © 2015 Taylor & Francis

  1. Colonic perforation with peritonitis in amoebiasis: a tropical disease with high mortality.

    Science.gov (United States)

    Jain, Bhupendra Kumar; Garg, Pankaj Kumar; Kumar, Anjay; Mishra, Kiran; Mohanty, Debajyoti; Agrawal, Vivek

    2013-01-01

    Invasive colonic amoebiasis presents primarily with dysentery; colonic perforation occurs rarely. Cases of amoebic colonic perforations have been reported sporadically over the past 20 years. A retrospective study was done in the surgical unit of a tertiary care hospital in North India. The case records of those patients were reviewed who underwent exploratory laparotomy from January 2011 to September 2012 and were diagnosed with amoebic colonic perforation on histopathological examination. Details concerning the clinical presentation, investigations, intraoperative findings, operative procedures, and postoperative outcomes were retrieved. Amongst, a total of 186 emergency exploratory laparotomies carried out during the study, 15 patients of amoebic colonic perforation were identified. The median age of the patients was 42 years (IQR 32.0-58.0) and the male to female ratio was 13:2. Previous history of colitis was present in only 1 patient. The preoperative diagnosis was perforation peritonitis in 12 patients; and intussusception, intestinal obstruction and ruptured liver abscess in 1 patient each. Ten patients had single perforation while 5 had multiple colonic perforations. All the patients except one had perforations in the right colon. Bowel resection was performed depending upon the site and extent of the colon involved-right hemicolectomy (8), limited ileocolic resection (6) and sigmoidectomy (1). Bowel continuity could be restored only in 2 of the 15 patients and a stoma was constructed in the remaining 13 patients. The overall mortality rate was found to be 40% (6/15). Amoebic colonic perforation is associated with unusually high mortality.

  2. Discharge Characteristics of the Nickel Hydroxide Electrode in 30% KOH

    International Nuclear Information System (INIS)

    Kim, Young Jin

    1989-01-01

    The discharge behavior of the nickel hydroxide electrode has been investigated in 30% KOH at 25 .deg. C. Two voltage plateaus are displayed on the discharge curve of C/20. It is shown that the impedance of the nickel hydroxide electrode increases with decrease of the discharge potential. The discharge behavior of the nickel hydroxide electrode has been investigated in 30% KOH indicating the reduction of the β-NiOOH to the β-Ni(OH) 2 by proton diffusion process and hence the electronic conductivity change of the nickel hydroxide electrode. Furthermore, the γ-NiOOH, produced by prolonged oxidation of the β-NiOOH in 30% KOH, discharges at a slightly lower potential than the β-Ni(OH) 2 that could result in the life-limiting factor of several alkaline electrolyte storage batteries using the nickel hydroxide electrode as the positive plate

  3. [Laparoscopic surgery for perforated peptic ulcer].

    Science.gov (United States)

    Yasuda, Kazuhiro; Kitano, Seigo

    2004-03-01

    Laparoscopic surgery has become the treatment of choice for the management of perforated peptic ulcer. The advantages of laparoscopic repair for perforated peptic ulcer include less pain, a short hospital stay, and an early return to normal activity. Although the operation time of laparoscopic surgery is significantly longer than that of open surgery, laparoscopic technique is safe, feasible, and with morbidity and mortality comparable to that of the conventional open technique. To benefit from the advantages offered by minimally invasive laparoscopic technique, further study will need to determine whether laparoscopic surgery is safe in patients with generalized peritonitis or sepsis.

  4. Perforated Meckel's diverticulum in omphalocele

    OpenAIRE

    Jin, Hanna; Han, Ji-Won; Oh, Chaeyoun; Kim, Hyun-Young; Jung, Sung-Eun

    2017-01-01

    Meckel's diverticulum is a rare condition in neonates with reports of concurrent Meckel's diverticulum and omphalocele being few. Herein, we present a case of omphalocele associated with perforated Meckel's diverticulum.

  5. SOUND TRANSMISSION LOSS OF A DOUBLE-LEAF PARTITION WITH MICRO-PERFORATED PLATE INSERTION UNDER DIFFUSE FIELD INCIDENCE

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    A. Putra

    2013-06-01

    Full Text Available In noise control applications, a double-leaf partition has been applied widely as a lightweight structure for noise insulation, such as in car doors, train bodies, and aircraft fuselages. Unfortunately, the insulation performance deteriorates significantly at mass-air-mass resonance due to coupling between the panels and the air in the gap. This paper investigates the effect of a micro-perforated panel (MPP, inserted in the conventional double-panel partition, on sound transmission loss at troublesome resonant frequencies. It is found that the transmission loss improves at this resonance if the MPP is located at a distance of less than half that of the air gap. A mathematical model is derived for the diffuse field incidence of acoustic loading.

  6. Perforated Meckel's diverticulitis complicating active Crohn's ileitis: a case report.

    Science.gov (United States)

    Schwenter, Frank; Gervaz, Pascal; de Saussure, Philippe; McKee, Thomas; Morel, Philippe

    2009-01-13

    In Crohn's disease, the extension of active terminal ileitis into a Meckel's diverticulum is possible, but usually has no impact on clinical decision-making. We describe an original surgical approach in a young woman presenting with a combination of perforated Meckel's diverticulitis and active Crohn's ileitis. We report the case of a 22-year-old woman with Crohn's disease, who was admitted for abdominal pain, fever and diarrhoea. CT scan demonstrated active inflammation of the terminal ileum, as well as a fluid collection in the right iliac fossa, suggesting intestinal perforation. Laparoscopy was performed and revealed, in addition to extensive ileitis, a 3 x 3 cm abscess in connection with perforated Meckel's diverticulitis. It was therefore possible to avoid ileocaecal resection by only performing Meckel's diverticulectomy; pathological examination of the surgical specimen revealed the presence of transmural inflammation with granulomas and perforation of the diverticulum at its extremity. Crohn's disease of the ileum may be responsible for Meckel's diverticulitis and cause perforation which, in this case, proved to be a blessing in disguise and spared the patient an extensive small bowel resection.

  7. Nickel Alloy, Corrosion and Heat-Resistant, Sheet, Strip, and Plate 72Ni - 15.5Cr - 0.95 (Cb (Nb) + Ta) - 2.5Ti - 0.70Al - 7.0Fe Consumable Electrode, Remelted or Vacuum Induction Melted, Solution Heat Treated, Precipitation-Hardenable

    CERN Document Server

    SAE Aerospace Standards. London

    2012-01-01

    Nickel Alloy, Corrosion and Heat-Resistant, Sheet, Strip, and Plate 72Ni - 15.5Cr - 0.95 (Cb (Nb) + Ta) - 2.5Ti - 0.70Al - 7.0Fe Consumable Electrode, Remelted or Vacuum Induction Melted, Solution Heat Treated, Precipitation-Hardenable

  8. A Five-Year Review of Perforated Peptic Ulcer Disease in Irrua, Nigeria.

    Science.gov (United States)

    Dongo, A E; Uhunmwagho, O; Kesieme, E B; Eluehike, S U; Alufohai, E F

    2017-01-01

    Peptic ulcer perforation is a common cause of emergency admission and surgery. This is the first study that documents the presentation and outcome of management in Irrua, Nigeria. This is a prospective study of all patients operated on for perforated peptic ulcer between April 1, 2010, and March 31, 2015. A structured questionnaire containing patients' demographics, operation findings, and outcome was filled upon discharge or death. There were 104 patients. 81 males and 23 females (M : F = 3.5 : 1). The age range was between 17 years and 95 years. The mean age was 48.99 years ± SD 16.1 years. The ratio of gastric to duodenal perforation was 1.88 : 1. Perforation was the first sign of peptic ulcer disease in 62 (59.6%). Pneumoperitoneum was detectable with plain radiographs in 95 (91%) patients. 72 (69.2%) had Graham's Omentopexy. Death rate was 17.3%. We note that gastric perforation is a far commoner disease in our environment. Perforation is often the first sign of peptic ulcer disease. We identify fasting amongst Christians as a risk factor for perforation.

  9. Spontaneous perforation of sigmoid colon in a child with acute lymphoblastic leukemia

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    Miolski Jelena

    2017-01-01

    Full Text Available Introduction. Perforation of the sigmoid colon is rare in children and its descriptions in medical literature are infrequent. Case Outline. In a 13-year-old boy with acute lymphoblastic leukemia, a ten-month course of chemotherapy was accompanied by many complications: parasitic infestation (Enterobius vermicularis, lung candidiasis, esophageal candidiasis, steroid diabetes, anaphylactoid reaction to L-asparaginase, febrile neutropenia, mucositis, anemia, thrombocytopenia, enterocolitis, and respiratory distress syndrome. During reinduction treatment, consisting of dexamethasone, vincristine, doxorubicin, and crisantaspase, he complained of abdominal pain and, upon radiographic examination, was found to have pneumoperitoneum. Because of suspicion of abdominal hollow organ perforation, he was subjected to explorative laparotomy, which yielded the diagnosis of perforation of the sigmoid colon. Conclusion. After an extensive review of the published reports on sigmoid perforation, all associated conditions that could possibly induce perforation – such as Hirschsprung’s disease or foreign body – were systematically excluded in our patient. Although typhlitis was the first diagnostic hypothesis, this was excluded by intraoperative findings, histopathology, and perforation site. To the best of our knowledge, this is the first report of a spontaneous perforation of the sigmoid colon in a child with acute lymphoblastic leukemia.

  10. Laparoscopic management of duodenal ulcer perforation: is it advantageous?

    Science.gov (United States)

    Palanivelu, C; Jani, Kalpesh; Senthilnathan, P

    2007-01-01

    Surgery is the mainstay of treatment of patients with peptic duodenal perforation. With the advent of minimal access techniques, laparoscopy is being used for the treatment of this condition. Retrospective analysis of 120 consecutive patients (mean age 44.5 years; 111 men) with duodenal ulcer perforation who had undergone laparoscopic surgery. 87 patients had history of tobacco consumption, 12 were chronic NSAID users, 72 had Helicobacter pylori infection and 36 had a co-morbid condition. The mean time to surgery from onset of symptoms was 28.4 hours. The median operating time was 46 minutes. All patients underwent laparoscopic closure of the perforation with Graham's patch omentopexy; 12 patients underwent additional definitive ulcer surgery. The morbidity rate was 7.5%; no patient needed conversion to open surgery or died. The mean postoperative hospital stay was 5.8 days. Results of laparoscopic management of perforated peptic ulcer are encouraging, with no conversion to open surgery, low morbidity and no mortality.

  11. Corneal perforation after conductive keratoplasty with previous refractive surgery.

    Science.gov (United States)

    Kymionis, George D; Titze, Patrik; Markomanolakis, Marinos M; Aslanides, Ioannis M; Pallikaris, Ioannis G

    2003-12-01

    A 56-year-old woman had conductive keratoplasty (CK) for residual hyperopia and astigmatism. Three years before the procedure, the patient had arcuate keratotomy, followed by laser in situ keratomileusis 2 years later for high astigmatism correction in both eyes. During CK, a corneal perforation occurred in the right eye; during the postoperative examination, an iris perforation and anterior subcapsule opacification were seen beneath the perforation site. The perforation was managed with a bandage contact lens and an antibiotic-steroid ointment; it had a negative Seidel sign by the third day. The surgery in the left eye was uneventful. Three months after the procedure, the uncorrected visual acuity was 20/32 and the best corrected visual acuity 20/20 in both eyes with a significant improvement in corneal topography. Care must be taken to prevent CK-treated spots from coinciding with areas in the corneal stroma that might have been altered by previous refractive procedures.

  12. Irreversible Electroporation of the Pancreas Using Parallel Plate Electrodes in a Porcine Model: A Feasibility Study.

    Science.gov (United States)

    Rombouts, Steffi J E; Nijkamp, Maarten W; van Dijck, Willemijn P M; Brosens, Lodewijk A A; Konings, Maurits; van Hillegersberg, R; Borel Rinkes, Inne H M; Hagendoorn, Jeroen; Wittkampf, Fred H; Molenaar, I Quintus

    2017-01-01

    Irreversible electroporation (IRE) with needle electrodes is being explored as treatment option in locally advanced pancreatic cancer. Several studies have shown promising results with IRE needles, positioned around the tumor to achieve tumor ablation. Disadvantages are the technical difficulties for needle placement, the time needed to achieve tumor ablation, the risk of needle track seeding and most important the possible occurrence of postoperative pancreatic fistula via the needle tracks. The aim of this experimental study was to evaluate the feasibility of a new IRE-technique using two parallel plate electrodes, in a porcine model. Twelve healthy pigs underwent laparotomy. The pancreas was mobilized to enable positioning of the paddles. A standard monophasic external cardiac defibrillator was used to perform an ablation in 3 separate parts of the pancreas; either a single application of 50 or 100J or a serial application of 4x50J. After 6 hours, pancreatectomy was performed for histology and pigs were terminated. Histology showed necrosis of pancreatic parenchyma with neutrophil influx in 5/12, 11/12 and 12/12 of the ablated areas at 50, 100, and 4x50J respectively. The electric current density threshold to achieve necrosis was 4.3, 5.1 and 3.4 A/cm2 respectively. The ablation threshold was significantly lower for the serial compared to the single applications (p = 0.003). The content of the ablated areas differed between the applications: areas treated with a single application of 50 J often contained vital areas without obvious necrosis, whereas half of the sections treated with 100 J showed small islands of normal looking cells surrounded by necrosis, while all sections receiving 4x 50 J showed a homogeneous necrotic lesion. Pancreatic tissue can be successfully ablated using two parallel paddles around the tissue. A serial application of 4x50J was most effective in creating a homogeneous necrotic lesion.

  13. Irreversible Electroporation of the Pancreas Using Parallel Plate Electrodes in a Porcine Model: A Feasibility Study.

    Directory of Open Access Journals (Sweden)

    Steffi J E Rombouts

    Full Text Available Irreversible electroporation (IRE with needle electrodes is being explored as treatment option in locally advanced pancreatic cancer. Several studies have shown promising results with IRE needles, positioned around the tumor to achieve tumor ablation. Disadvantages are the technical difficulties for needle placement, the time needed to achieve tumor ablation, the risk of needle track seeding and most important the possible occurrence of postoperative pancreatic fistula via the needle tracks. The aim of this experimental study was to evaluate the feasibility of a new IRE-technique using two parallel plate electrodes, in a porcine model.Twelve healthy pigs underwent laparotomy. The pancreas was mobilized to enable positioning of the paddles. A standard monophasic external cardiac defibrillator was used to perform an ablation in 3 separate parts of the pancreas; either a single application of 50 or 100J or a serial application of 4x50J. After 6 hours, pancreatectomy was performed for histology and pigs were terminated.Histology showed necrosis of pancreatic parenchyma with neutrophil influx in 5/12, 11/12 and 12/12 of the ablated areas at 50, 100, and 4x50J respectively. The electric current density threshold to achieve necrosis was 4.3, 5.1 and 3.4 A/cm2 respectively. The ablation threshold was significantly lower for the serial compared to the single applications (p = 0.003. The content of the ablated areas differed between the applications: areas treated with a single application of 50 J often contained vital areas without obvious necrosis, whereas half of the sections treated with 100 J showed small islands of normal looking cells surrounded by necrosis, while all sections receiving 4x 50 J showed a homogeneous necrotic lesion.Pancreatic tissue can be successfully ablated using two parallel paddles around the tissue. A serial application of 4x50J was most effective in creating a homogeneous necrotic lesion.

  14. The posterolateral mid-forearm perforator flap: anatomical study and clinical application.

    Science.gov (United States)

    Zhuang, Yue-Hong; Lin, Jian; Fu, Fei-Huan; Cai, Zhen-De; Huang, Hui-Mei; Zheng, He-Ping

    2013-11-01

    Defects sustained at the distal forearm are common and pedicled perforator flaps have unique advantages in resurfacing it. The purpose of this study is to reappraise the anatomy of the perforator in the posterolateral aspect of the mid-forearm and present our clinical experience on using perforator flaps based on it for reconstruction of defects in the distal forearm. This study was divided into anatomical study and clinical application. In the anatomical study, 30 preserved upper limbs were used. Clinically, 11 patients with defects at the forearm underwent reconstruction with the posterolateral mid-forearm perforator flaps. The defects, ranging from 4.5 × 2.5 cm to 10.5 × 4.5 cm, were located at the dorsal aspect of the distal forearm in 6 cases and at the volar aspect of the distal forearm in 5 cases. Three patterns of the perforator were observed in the posterolateral aspect of the mid-forearm, which originated from the posterior interosseous artery, the proximal segment of the radial artery or the radial recurrent artery, and the middle segment of the radial artery, respectively. The perforator was located 11.8 ± 0.2 cm to 15.8 ± 0.4 cm inferior to the lateral humeral epicondyle. Clinically, flaps in 8 cases survived uneventfully, while the other 3 cases suffered mild marginal epidermal necrosis, which was cured with continuous dress changing. The location of the perforator at the posterolateral aspect of the mid-forearm is consistent; the posterolateral mid-forearm perforator flap is particularly suitable to cover defects in the distal one-third of the forearm. Copyright © 2013 Wiley Periodicals, Inc.

  15. Three-dimensional numerical simulation of wave interaction with perforated quasi-ellipse caisson

    Directory of Open Access Journals (Sweden)

    Yong-xue Wang

    2011-03-01

    Full Text Available The finite difference method and the volume of fluid (VOF method were used to develop a three-dimensional numerical model to study wave interaction with a perforated caisson. The partial cell method was adopted to solve this type of problem for the first time. The validity of the present model, with and without the presence of caisson structures, was examined by comparing the model results with experimental data. Then, the numerical model was used to investigate the effects of various wave and structure parameters on the wave force and wave runup of the perforated quasi-ellipse caisson. Compared with the solid quasi-ellipse caisson, the wave force on the perforated quasi-ellipse caisson is significantly reduced with increasing porosity of the perforated quasi-ellipse caisson. Furthermore, the perforated quasi-ellipse caisson can also reduce the wave runup, and it tends to decrease with the increase of the porosity of the perforated quasi-ellipse caisson and the relative wave height.

  16. Peritonitis by jejunal ulcer perforation in a child: a case report

    Directory of Open Access Journals (Sweden)

    Ndèye Aby Ndoye

    2017-01-01

    Full Text Available Ulcer perforation is a rare cause of peritonitis in children. The cases reported in the literature are caused by peptic ulcer. We report on a case of peritonitis caused by jejunal ulcer perforation, discovered in a girl's abdomen during an acute surgical procedure. The treatment consisted of a resection of the perforation followed by an end-to-end anastomosis. Postoperative period was uneventful.

  17. Single center experience in laparoscopic treatment of gallbladder perforation.

    Science.gov (United States)

    Sahbaz, Nuri Alper; Peker, Kivanc Derya; Kabuli, Hamit Ahmet; Gumusoglu, Alpen Yahya; Alis, Halil

    2017-12-01

    Gallbladder perforation (GBP) is a rare disease with potential mortality. Previous series have reported an incidence of approximately 2-11% and it still continues to be a significant problem for surgeons. To present our clinical experience with gallbladder perforation. The records of 2754 patients who received surgical treatment for cholelithiasis between 2010 and 2016 were reviewed retrospectively. One hundred thirty-three patients had gallbladder perforation. Age, gender, time from the onset of symptoms, diagnostic procedures, surgical treatment, morbidity and mortality rates were evaluated. 15.78% of patients had a body mass index > 35. 6.76% had chronic obstructive pulmonary disease, 6.76% had cardiac disease, 10.52% had diabetes and 4.51% had sepsis. American Society of Anesthesiology scores were I in 54.13%, II in 35.33%, III in 6.01% and IV in 4.51% of the patients. 27.81% of patients were diagnosed during surgery. The perforation site was the gallbladder fundus in 69.17%, body in 17.30%, Hartman's pouch in 10.53% and cystic duct in 3% of patients. Treatment modalities were laparoscopic cholecystectomy in 82.71%, open cholecystectomy in 3%, percutaneous drainage catheters + laparoscopic cholecystectomy in 3%, laparoscopic cholecystectomy + fistula repair in 10.53% and open cholecystectomy + fistula repair in 0.75% of patients. Mean length of hospital stay was 1.69 days. Mortality and morbidity rates were 8.27% and 10.52%, respectively. Histopathology results were acute cholecystitis in 69.93%, chronic cholecystitis in 20.30% and acute exacerbation over chronic cholecystitis in 9.77% of patients. Appropriate classification and management of perforated cholecystitis is essential. Laparoscopic cholecystectomy is a safe and feasible method to decrease morbidity in gallbladder perforations.

  18. Perforated peptic ulcer - an update.

    Science.gov (United States)

    Chung, Kin Tong; Shelat, Vishalkumar G

    2017-01-27

    Peptic ulcer disease (PUD) affects 4 million people worldwide annually. The incidence of PUD has been estimated at around 1.5% to 3%. Perforated peptic ulcer (PPU) is a serious complication of PUD and patients with PPU often present with acute abdomen that carries high risk for morbidity and mortality. The lifetime prevalence of perforation in patients with PUD is about 5%. PPU carries a mortality ranging from 1.3% to 20%. Thirty-day mortality rate reaching 20% and 90-d mortality rate of up to 30% have been reported. In this review we have summarized the current evidence on PPU to update readers. This literature review includes the most updated information such as common causes, clinical features, diagnostic methods, non-operative and operative management, post-operative complications and different scoring systems of PPU. With the advancement of medical technology, PUD can now be treated with medications instead of elective surgery. The classic triad of sudden onset of abdominal pain, tachycardia and abdominal rigidity is the hallmark of PPU. Erect chest radiograph may miss 15% of cases with air under the diaphragm in patients with bowel perforation. Early diagnosis, prompt resuscitation and urgent surgical intervention are essential to improve outcomes. Exploratory laparotomy and omental patch repair remains the gold standard. Laparoscopic surgery should be considered when expertise is available. Gastrectomy is recommended in patients with large or malignant ulcer.

  19. Perforated peptic ulcer - an update

    Science.gov (United States)

    Chung, Kin Tong; Shelat, Vishalkumar G

    2017-01-01

    Peptic ulcer disease (PUD) affects 4 million people worldwide annually. The incidence of PUD has been estimated at around 1.5% to 3%. Perforated peptic ulcer (PPU) is a serious complication of PUD and patients with PPU often present with acute abdomen that carries high risk for morbidity and mortality. The lifetime prevalence of perforation in patients with PUD is about 5%. PPU carries a mortality ranging from 1.3% to 20%. Thirty-day mortality rate reaching 20% and 90-d mortality rate of up to 30% have been reported. In this review we have summarized the current evidence on PPU to update readers. This literature review includes the most updated information such as common causes, clinical features, diagnostic methods, non-operative and operative management, post-operative complications and different scoring systems of PPU. With the advancement of medical technology, PUD can now be treated with medications instead of elective surgery. The classic triad of sudden onset of abdominal pain, tachycardia and abdominal rigidity is the hallmark of PPU. Erect chest radiograph may miss 15% of cases with air under the diaphragm in patients with bowel perforation. Early diagnosis, prompt resuscitation and urgent surgical intervention are essential to improve outcomes. Exploratory laparotomy and omental patch repair remains the gold standard. Laparoscopic surgery should be considered when expertise is available. Gastrectomy is recommended in patients with large or malignant ulcer. PMID:28138363

  20. Medical image of the week: eosphageal perforation

    Directory of Open Access Journals (Sweden)

    Bilal J

    2015-04-01

    Full Text Available No abstract available. Article truncated after 150 words. A 74 year old man with a past medical history of esophageal strictures status post dilatation, coronary artery disease status post CABG, and atrial fibrillation presented to hospital with complaints of severe chest pain that began after the consumption of tortilla chips one hour prior to presentation. Electrocardiogram and cardiac enzymes were not consistent with acute coronary syndrome. Chest X-ray was consistent with a widened mediastinal silhouette. Contrast esophogram was negative for extra luminal extravasation. CT scan of the chest with oral contrast demonstrated thickening of the mid-thoracic esophagus with an extra-luminal focus of gas in the mediastinum along with fluid along the inferior aspect of the esophagus (Figures 1 and 2. These findings were concerning for esophageal perforation. The patient was taken to the operating room for endoscopy which showed micro perforation in mid-esophagus. Esophageal perforation remains a highly morbid condition. Mortality rates are based predominantly on time of ...

  1. Use of Computed Tomography to Determine Perforation in Patients With Acute Appendicitis.

    Science.gov (United States)

    Gaskill, Cameron E; Simianu, Vlad V; Carnell, Jonathan; Hippe, Daniel S; Bhargava, Puneet; Flum, David R; Davidson, Giana H

    Urgent appendectomy has long been the standard of care for acute appendicitis. Six randomized trials have demonstrated that antibiotics can safely treat appendicitis, but approximately 1 in 4 of these patients eventually requires appendectomy. Overall treatment success may be limited by complex disease including perforation. Patients׳ success on antibiotic therapy may depend on preoperative identification of complex disease on imaging. However, the effectiveness of computed tomography (CT) in differentiating complex disease including perforated from nonperforated appendicitis remains to be determined. The purpose of this study was to assess the preoperative diagnostic accuracy of CT in determining appendiceal perforation in patients operated for acute appendicitis. We performed a retrospective review of pathology and radiology reports from consecutive patients who presented to the emergency department with suspicion for acute appendicitis between January 2012 and May 2015. CT scans were re-reviewed by abdominal imaging fellowship-trained radiologists using standardized criteria, and the radiologists were blinded to pathology and surgical findings. Radiologists specifically noted presence or absence of periappendiceal gas, abscess, appendicolith, fat stranding, and bowel wall thickening. The overall radiologic impression as well as these specific imaging findings was compared to results of pathology and operative reports. Pathology reports were considered the standard for diagnostic accuracy. Eighty-nine patients (65% male, average age of 34 years) presenting with right lower quadrant pain underwent CT imaging and prompt appendectomy. Final pathology reported perforation in 48% (n = 43) of cases. Radiologic diagnosis of perforation was reported in 9% (n = 8), correctly identifying perforation in 37.5% (n = 3), and incorrectly reporting perforation in 62.5% of nonperforated cases per pathology. Radiology missed 93% (n = 40) of perforations postoperatively diagnosed

  2. Perforated Meckel's diverticulum in omphalocele

    Directory of Open Access Journals (Sweden)

    Hanna Jin

    2017-02-01

    Full Text Available Meckel's diverticulum is a rare condition in neonates with reports of concurrent Meckel's diverticulum and omphalocele being few. Herein, we present a case of omphalocele associated with perforated Meckel's diverticulum.

  3. Miniaturized polymer electrolyte fuel cell (PEFC) stack using micro structured bipolar plate

    Energy Technology Data Exchange (ETDEWEB)

    Veziridis, Z; Scherer, G G; Marmy, Ch; Glaus, F [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    In Polymer Electrolyte Fuel Cell (PEFC) technology the reducing of volume and mass of the fuel cell stack and the improvement of catalyst utilization are of great interest. These parameters affect applicability and system cost. In this work we present an alternative way for reducing the stack volume by combining gas distribution and catalytic active area in one plate. Micro machined glassy carbon electrodes serve as support material for the platinum catalyst, as well as gas distributor at the same time. A comparison of these electrodes with conventional platinum-black gas diffusion electrodes under fuel cell conditions shows that the new system is a promising electrode type for enhanced power density and catalyst utilization. (author) 3 figs., 5 refs.

  4. Vitrectomy in double-perforation gunshot injury

    Directory of Open Access Journals (Sweden)

    Abd El Alim Mohamed A

    2013-11-01

    Full Text Available Ahmed Abd El Alim MohamedOphthalmology department, Ain Shams University, Cairo, EgyptObjective: This study sought to evaluate the result of pars plana vitrectomy in patients with gunshot wounds involving double perforation.Methods: This was a retrospective, noncomparative, interventional case series.Results: Eighteen patients (18 eyes with double-perforation gunshot injuries were treated from February 2010 to March 2012. The group included 16 men (88% and two women (11%; the mean age was 24 (15–33 years. In each case, vitrectomy was scheduled 1–6 weeks after repair of the entrance site. Associated retinal detachments were observed in two eyes (11%, retinal incarceration was observed surrounding the exit site in three eyes (16%, and retention of an intraocular foreign body was observed in two cases. After a follow-up period of 8 ± 2 months, two eyes (11% had achieved visual acuity (VA of 0.5, nine eyes (50% had achieved VA between 0.5 and 0.1, and seven eyes (38% had achieved VA between 0.1 and hand movement. The main reasons for functional failure (VA 0.1 to hand movement were macular dragging (due to fibrosis at the exit site near the macula in seven cases (38%, submacular hemorrhage in four cases (22%, and epimacular fibrosis in five cases (27%. All cases developed postoperative exotropia. One case (5% developed postoperative hemorrhage. No cases exhibited signs of postoperative redetachment.Conclusion: The outcome of pars plana vitrectomy in cases with double perforations is variable. Factors including the surgeon's skill level, the time to surgery, and the efficacy of the intraocular tamponade affect the postoperative outcome.Keywords: pars plana vitrectomy, gunshot injury, double perforation

  5. Corrosion Behavior of Nickel-Plated Alloy 600 in High Temperature Water

    International Nuclear Information System (INIS)

    Kim, Ji Hyun; Hwang, Il Soon

    2008-01-01

    In this paper, electrochemical and microstructural characteristics of nickel-plated Alloy 600 wee investigated in order to identify the performance of electroless Ni-plating on Alloy 600 in high-temperature aqueous condition with the comparison of electrolytic nickel-plating. For high temperature corrosion test of nickel-plated Alloy 600, specimens were exposed for 770 hours to typical PWR primary water condition. During the test, open circuit potentials (OCP's) of all specimens were measured using a reference electrode. Also, resistance to flow accelerated corrosion (FAC) test was examined in order to check the durability of plated layers in high-velocity flow environment at high temperature. After exposures to high flow rate aqueous condition, the integrity of surfaces was confirmed by using both scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). For the field application, a remote process for electroless nickel-plating was demonstrated using a plate specimen with narrow gap on a laboratory scale. Finally, a practical seal design was suggested for more convenient application

  6. Lack of utility of measuring serum bilirubin concentration in distinguishing perforation status of pediatric appendicitis.

    Science.gov (United States)

    Bonadio, William; Bruno, Santina; Attaway, David; Dharmar, Logesh; Tam, Derek; Homel, Peter

    2017-06-01

    Pediatric appendicitis is a common, potentially serious condition. Determining perforation status is crucial to planning effective management. Determine the efficacy of serum total bilirubin concentration [STBC] in distinguishing perforation status in children with appendicitis. Retrospective review of 257 cases of appendicitis who received abdominal CT scan and measurement of STBC. There were 109 with perforation vs 148 without perforation. Although elevated STBC was significantly more common in those with [36%] vs without perforation [22%], the mean difference in elevated values between groups [0.1mg/dL] was clinically insignificant. Higher degrees of hyperbilirubinemia [>2mg/dL] were rarely encountered [5%]. Predictive values for elevated STBC in distinguishing perforation outcome were imprecise [sensitivity 38.5%, specificity 78.4%, PPV 56.8%, NPV 63.4%]. ROC curve analysis of multiple clinical and other laboratory factors for predicting perforation status was unenhanced by adding the STBC variable. Specific analysis of those with perforated appendicitis and percutaneously-drained intra-abdominal abscess which was culture-positive for Escherichia coli showed an identical rate of STBC elevation compared to all with perforation. The routine measurement of STBC does not accurately distinguish perforation status in children with appendicitis, nor discern infecting organism in those with perforation and intra-abdominal abscess. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. An unusual cause of duodenal perforation due to a lollipop stick

    Directory of Open Access Journals (Sweden)

    Mi Jin Kim

    2013-04-01

    Full Text Available Children have a natural tendency to explore objects with their mouths; this can result in the swallowing of foreign objects. Most ingested foreign bodies pass uneventfully through the gastrointestinal tract.However, some foreign bodies cause obstruction or perforation of the gastrointestinal tract, requiring surgical intervention. Perforation of the gastrointestinal tract may be associated with considerable morbidity and mortality. The most common sites of intestinal foreign body perforation are the ileocecal and rectosigmoid regions. Foreign body perforation of the duodenum is relatively uncommon. We report the first Korean case of duodenal perforation by an ingested 8-cm lollipop stick. Lollipops are popular with the children and fairly accessible to them, as most parents are not aware of their potential harm. Pediatric clinicians should be aware of the risks associated with lollipop stick ingestion. Our report also describes the feasibility and safety of laparoscopic diagnosis and management of pediatric patients with peritonitis induced by the ingestion of foreign bodies.

  8. Endoscopic Management of Gastrointestinal Leaks and Perforation with Polyglycolic Acid Sheets

    Directory of Open Access Journals (Sweden)

    Sojung Han

    2017-05-01

    Full Text Available Gastrointestinal (GI leakage, fistulae, and perforations can be serious and life threatening. There has been a paradigm shift in the management approach of these conditions, from surgical to conservative, including endoscopic management. Here, we report two cases of endoscopic closure of a GI fistula and perforation using polyglycolic acid (PGA sheets with fibrin glue. The first case is of an anastomotic leak detected after subtotal gastrectomy with gastroduodenostomy. After failed application of endoclips, a PGA sheet was applied, and the fistula was successfully closed. The second case was of a 15-mm large perforated gastric ulcer, which was also successfully closed with a PGA sheet. This is the first case report that PGA sheet was used for the treatment of overt perforation. The outcome of these cases suggest that endoscopic closure using PGA sheets can be considered as a useful alternative for the management of GI leakage, fistulae, and perforations.

  9. Changing trend in emergency surgery for perforated duodenal ulcer

    International Nuclear Information System (INIS)

    Gurteyik, E.

    2003-01-01

    Objective: To evaluate changes in the emergency surgery of the duodenal ulcer. Subjects and Methods: Hospital records of 523 surgically treated patients, with duodenal ulcer perforation, during the period of 25 years 91975-1999) in the same surgical department, was retrospectively analysed. Changing aspects of emergency surgery of peptic ulcer disease, in the recent period, were determined in respect to number of operations per year and in the choice of operative methods. Results: The average number of patients and emergency operations per year was 21. No significant change was observed during the study period. Elective operations gradually decreased in the last ten years, and none was performed in the last 4 years. On the other hand, 226 emergency interventions for duodenal ulcer perforation were performed in the last ten years and 84 interventions in the last 4 years. Definitive anti-ulcer surgery was performed in 42% of patients between 1985 and 1994. Simple closure of the perforation plus treatment with proton pump inhibitors and with anti-Helicobacter pylori medication was the method in 80% during the last year. Conclusion: Emergency surgery for perforated duodenal ulcer preserves its steady rate despite disappearance of elective operations after tremendous progress in medical control of peptic ulcer disease. There is an obvious return from definitive anti-ulcer surgery to simple closure of the perforation followed by antisecretory and antibacterial medications in the recent years. (author)

  10. Gastric cancer perforation: experience from a tertiary care hospital.

    Science.gov (United States)

    Kandel, Bishnu Prasad; Singh, Yogendra; Singh, Keshav Prasad; Khakurel, Mahesh

    2013-01-01

    Gastric cancer perforation can occurs in advanced stage of the disease and is often associated with a high morbidity and mortality. Peritonitis due to perforation needs emergency laparotomy and different surgical procedures can be performed for definitive treatment. Surgical procedures largely depend on the stage of the disease and general condition of the patient. This study was carried out to evaluate the outcome and role of different surgical procedures in gastric cancer perforation. Medical record of patients with gastric perforation, who were treated during ten years period, was reviewed retrospectively. Data regarding clinical presentation, surgical procedures, staging and survival of patients were obtained. Features suggestive of diffuse peritonitis were evident in all cases. The majority of the patients underwent emergency surgery except one who died during resuscitation. The majority of patients were in stage III and stage IV. Surgical procedure includes simple closure and omental patch in five patients, simple closure and gastrojejunostomy in nine patients, gastrectomy in six patients and Devine's antral exclusion in one patient. Surgical site infection was the most common (45.5%) postoperative complication. Four patients died within one month of the surgery. Three patients who underwent gastrectomy survived for one year and one patient survived for five years. Although gastric cancer perforation usually occurs in advanced stage of the disease, curative resection should be considered as far as possible.

  11. Duodenal perforation precipitated by scrub typhus

    Directory of Open Access Journals (Sweden)

    Raghunath Rajat

    2015-01-01

    Full Text Available Scrub typhus is an acute febrile illness usually presenting with fever, myalgia, headache, and a pathognomonic eschar. Severe infection may lead to multiple organ failure and death. Gastrointestinal tract involvement in the form of gastric mucosal erosions and ulcerations owing to vasculitis resulting in gastrointestinal bleeding is common. This process may worsen a pre-existent asymptomatic peptic ulcer, causing duodenal perforation, and present as an acute abdomen requiring surgical exploration. We report the case of a patient with no previous symptoms or risk factors for a duodenal ulcer, who presented with an acute duodenal perforation, probably precipitated by scrub typhus infection.

  12. Bowel Perforation in Premature Infants with Necrotizing Enterocolitis: Risk Factors and Outcomes

    Directory of Open Access Journals (Sweden)

    Lingling Yu

    2016-01-01

    Full Text Available We aim to determine risk factors and clinical outcomes for bowel perforation in premature infants with NEC. We analyzed clinical data of 57 cases of premature infants with NEC at our NICU between January 2010 and December 2012. Based on the presence of bowel perforation, we divided these infants into two groups: perforated NEC group (n=10 and nonperforated NEC group (n=47. We compared general information, clinical characteristics, and laboratory findings between groups. The perforated NEC group, compared to the nonperforated NEC group, had significantly lesser gestational age, lower birth weight, higher prevalence of apnea, mechanical ventilation, sepsis and shock, lower blood pH, higher levels of blood glucose, abnormal WBC count and thrombocytopenia, and elevated CRP (all P<0.05. Moreover, the perforated NEC group had significantly longer durations of fasting and TPN usage, higher incidences of EUGR and cholestasis, longer duration of antibiotics, higher frequency of advanced antibiotics use, and poorer prognosis than the nonperforated NEC group (all P<0.05. Bowel perforation in premature infants with NEC was associated with multiple risk factors. Early identification of some of these risk factors in premature infants with NEC may help implement early intervention to reduce the incidence of bowel perforation and thereby improve the prognosis.

  13. Microbial fuel cell design and characterization for electricity production from wastewaters

    International Nuclear Information System (INIS)

    Poggi-Varaldo, H. M.; Carmona-Martinez, A.; Solorza-Feria, O.

    2009-01-01

    The purpose of this research was to design and characterize a lan scale, one chamber microbial fuel cell (MFC) that will be used for the treatment of a variety of wastewaters, acidogenic extracts, and leachates. The MFC consisted of a horizontal cylinder built in plexiglass 78 mm long between electrodes) and 48 mm internal diameter. The cylinder was fitted with a circular anode made of stainless steel plate 1 mm thickness and a cathode made of a sandwich of 3 circular layers (from inside to outside): proton exchange membrane, flexible carbon-cloth containing 0.5 mg/cm 2 platinum catalysts, and a perforated plate of stainless steel 1 mm thickness. (Author)

  14. Design and Modelling of a Microfluidic Electro-Lysis Device with Controlling Plates

    Science.gov (United States)

    Jenkins, A.; Chen, C. P.; Spearing, S.; Monaco, L. A.; Steele, A.; Flores, G.

    2006-04-01

    Many Lab-on-Chip applications require sample pre-treatment systems. Using electric fields to perform cell lysis in bio-MEMS systems has provided a powerful tool which can be integrated into Lab-on-a- Chip platforms. The major design considerations for electro-lysis devices include optimal geometry and placement of micro-electrodes, cell concentration, flow rates, optimal electric field (e.g. pulsed DC vs. AC), etc. To avoid electrolysis of the flowing solution at the exposed electrode surfaces, magnitudes and the applied voltages and duration of the DC pulse, or the AC frequency of the AC, have to be optimized for a given configuration. Using simulation tools for calculation of electric fields has proved very useful, for exploring alternative configurations and operating conditions for achieving electro cell-lysis. To alleviate the problem associated with low electric fields within the microfluidics channel and the high voltage demand on the contact electrode strips, two ''control plates'' are added to the microfluidics configuration. The principle of placing the two controlling plate-electrodes is based on the electric fields generated by a combined insulator/dielectric (glass/water) media. Surface charges are established at the insulator/dielectric interface. This paper discusses the effects of this interface charge on the modification of the electric field of the flowing liquid/cell solution.

  15. Optimization of an integrated electrodisinfection/electrocoagulation process with Al bipolar electrodes for urban wastewater reclamation.

    Science.gov (United States)

    Cotillas, Salvador; Llanos, Javier; Cañizares, Pablo; Mateo, Sara; Rodrigo, Manuel A

    2013-04-01

    In this work, a novel integrated electrochemical process for urban wastewater regeneration is described. The electrochemical cell consists in a Boron Doped Diamond (BDD) or a Dimensionally Stable Anode (DSA) as anode, a Stainless Steel (SS) as cathode and a perforated aluminum plate, which behaves as bipolar electrode, between anode and cathode. Thus, in this cell, it is possible to carry out, at the same time, two different electrochemical processes: electrodisinfection (ED) and electrocoagulation (EC). The treatment of urban wastewater with different anodes and different operating conditions is studied. First of all, in order to check the process performance, experiments with synthetic wastewaters were carried out, showing that it is possible to achieve a 100% of turbidity removal by the electrodissolution of the bipolar electrode. Next, the effect of the current density and the anode material are studied during the ED-EC process of actual effluents. Results show that it is possible to remove Escherichia coli and turbidity simultaneously of an actual effluent from a WasteWater Treatment Facility (WWTF). The use of BDD anodes allows to remove the E. coli completely at an applied electric charge of 0.0077 A h dm(-3) when working with a current density of 6.65 A m(-2). On the other hand, with DSA anodes, the current density necessary to achieve the total removal of E. coli is higher (11.12 A m(-2)) than that required with BDD anodes. Finally, the influence of cell flow path and flow rate have been studied. Results show that the performance of the process strongly depends on the characteristics of the initial effluent (E. coli concentration and Cl(-)/NH(4)(+) initial ratio) and that a cell configuration cathode (inlet)-anode (outlet) and a higher flow rate enhance the removal of the turbidity from the treated effluent. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Risk factors for reintervention after surgery for perforated gastroduodenal ulcer

    DEFF Research Database (Denmark)

    Hasselager, R B; Lohse, N; Duch, P

    2016-01-01

    BACKGROUND: Perforated gastroduodenal ulcer carries a high mortality rate. Need for reintervention after surgical repair is associated with worse outcome, but knowledge on risk factors for reintervention is limited. The aim was to identify prognostic risk factors for reintervention after perforated...... gastroduodenal ulcer in a nationwide cohort. METHODS: All patients treated surgically for perforated gastroduodenal ulcer in Denmark between 2003 and 2014 were included using data from the Danish Clinical Register of Emergency Surgery. Potential risk factors for reintervention were assessed, and their crude...... and adjusted associations calculated by the competing risks subdistribution hazards approach. RESULTS: A total of 4086 patients underwent surgery for perforated gastroduodenal ulcer during the study interval. Median age was 71·1 (i.q.r. 59·6-81·0) years and the overall 90-day mortality rate was 30·8 per cent...

  17. Posterior perforation of gastric ulcer: a rare surgical emergency ...

    African Journals Online (AJOL)

    BACKGROUND:Gastric ulcer perforation is a rare surgical emergency.Posterior gastric ulcer is even rarer and usually has a delayed presentation with attendant greater morbidity and mortality. AIM:To report a case of posterior perforation of gastric ulcer and review the literature. CASE REPORT:A 65yr old driver was seen in ...

  18. Advanced screening of electrode couples

    Science.gov (United States)

    Giner, J. D.; Cahill, K.

    1980-01-01

    The chromium (Cr(3+)/Cr(2+)) redox couple (electrolyte and electrode) was investigated to determine its suitability as negative electrode for the iron (Fe(3+)/Fe(2+))-chromium (Cr(3+)/Cr(2+)) redox flow battery. Literature search and laboratory investigation established that the solubility and stability of aqueous acidic solutions of chromium(3) chloride and chromium(2) chloride are sufficient for redox battery application. Four categories of electrode materials were tested; namely, metals and metalloid materials (elements and compounds), alloys, plated materials, and Teflon-bonded materials. In all, the relative performance of 26 candidate electrode materials was evaluated on the basis of slow scan rate linear sweep voltammetry in stirred solution. No single material tested gave both acceptable anodic an acceptable cathodic performance. However, the identification of lead as a good cathodic electrocatalyst and gold as a good anodic electrocatalyst led to the invention of the lead/gold combination electrocatalyst. This type of catalyst can be fabricated in several ways and appears to offer the advantages of each metal without the disadvantages associated with their use as single materials. This lead/gold electrocatalyst was tested by NASA-Lewis Research Center in complete, flowing, redox batteries comprising a stack of several cells. A large improvement in the battery's coulombic and energy efficiency was observed.

  19. ASSESSMENT OF SEVERITY OF PERFORATED PERITONITIS USING MODIFIED APACHE II SCORE

    Directory of Open Access Journals (Sweden)

    L. Rajeswar Reddy

    2016-06-01

    Full Text Available Acute generalised peritonitis from gastrointestinal hollow viscus perforation is a potentially life threatening condition. It is a common surgical emergency in many general surgical units in the developing countries and it is often associated with high morbidity and mortality. Grading the severity of acute peritonitis has assisted in no small way in decision making and has improved therapy in the management of severely ill patients. Empirically based risk assessment for important clinical events has been extremely useful in evaluating new therapies, in monitoring resources for effective use and improving quality of care. MATERIAL AND METHODS A prospective survey of patients with acute generalised peritonitis due to gastrointestinal perforation was carried out in general surgical wards of KIMS Hospital, Amalapuram during the period starting from July 2013-November 2016. The study population consisted of 50 consecutive patients who had laparotomy during the study period for acute peritonitis due to gastrointestinal perforation, after diagnostic conformation. RESULT AND DISCUSSION The most common cause of peritonitis in our study was perforated duodenal ulcer (31 cases, followed by appendicular perforation (7 cases, followed by stomach perforation (7 cases. Despite delay in seeking treatment, the overall mortality rate (14% was favourably comparable with other published series.

  20. Test of freonless operation of resistive plate chambers with glass electrodes--1 mm gas gap vs 2 mm gas gap

    CERN Document Server

    Sakaue, H; Takahashi, T; Teramoto, Y

    2002-01-01

    Non-freon gas mixtures (Ar/iso-C sub 4 H sub 1 sub 0) were tested as the chamber gas for 1 and 2 mm gas gap Resistive Plate Chambers (RPCs) with float glass as the resistive electrodes, operated in the streamer mode. With the narrower (1 mm) gas gap, streamer charge is reduced (approx 1/3), which reduces the dead time (and dead area), associated with each streamer, improving the detection efficiency. The best performance was obtained for two cases: Ar/iso-C sub 4 H sub 1 sub 0 =50/50 and 60/40. For the 50/50 mixture, a detection efficiency of better than 98% was obtained for the 1 mm gap RPC, while the efficiency was 95% for the 2 mm gap RPC, each operated as a double-gap RPC. The measured time resolution (rms) was 1.45+-0.05 (2.52+-0.09) ns for the 1 (2) mm gap RPC for the 50/50 mixture.

  1. Spontaneous Uterine Perforation of Pyometra Presenting as Acute Abdomen

    Directory of Open Access Journals (Sweden)

    Toshihiro Kitai

    2014-01-01

    Full Text Available Pyometra is the accumulation of pus in the uterine cavity, and spontaneous perforation of pyometra resulting in generalized diffuse peritonitis is extremely uncommon. We report a rare case of diffuse peritonitis caused by spontaneous perforation of pyometra. A 66-year-old postmenopausal woman with diffuse abdominal pain and vomiting was admitted to our institution. She had a history of mixed connective-tissue disease and had been taking steroids for 20 years. Under a diagnosis of generalized peritonitis secondary to perforation of the gastrointestinal tract or uterus, supravaginal hysterectomy and bilateral salpingo-oophorectomy were performed. Unfortunately, wound dehiscence and infection occurred during the postoperative course, which were exacerbated by her immunocompromised state. Despite intensive care and a course of antibiotics, the patient died of multiple organ failure resulting from sepsis on the 36th postoperative day. Although correct diagnosis, early intervention, and proper treatment can reduce morbidity and mortality of spontaneous perforation of pyometra, if severe infection occurs, this disease can be life threatening for immunocompromised hosts.

  2. An investigation of the damaged zone created by perforating

    International Nuclear Information System (INIS)

    Pucknell, J.K.; Behrmann, L.A.

    1991-01-01

    This paper reports on underbalance perforation flow experiments performed on reservoir and outcrop sandstones to investigate the perforation damaged zone. Cores from several different formations were perforated under reservoir conditions. After perforating, the cores were examined using CAT scans (Computer Aided tomography), thin sections and mercury porosimetry. In conjunction with these measurements, permeabilities in the damaged zone were measured using a minipermeameter and radial flow permeameter or were estimated from pore size distribution. The density and porosity of the damaged zone (at least for saturated rocks) is essentially the same as that in the undamaged rock. The damaged zone is not compacted, contrary to suggestions made in earlier work. However, the creation of this zone involves the destruction of large pores. The volume lost from these pores is replaced by microfractures created when rock grains are fractured by penetration of the shaped charge jet. This reduction in the average pore size causes a reduction in the permeability with the damaged zone. Although direct measurement of this permeability was made difficult by naturally occurring permeability variations, unambiguous measurements were obtained

  3. Costs of treating bleeding and perforated peptic ulcers in The Netherlands.

    Science.gov (United States)

    de Leest, Helena; van Dieten, Hiske; van Tulder, Maurits; Lems, Willem F; Dijkmans, Ben A C; Boers, Maarten

    2004-04-01

    Gastrointestinal toxicity of nonsteroidal antiinflammatory drugs includes perforations and bleeds. Several preventive strategies are being tested for cost-effectiveness, but little is known about the costs of the complications they are trying to prevent. We estimated the direct costs of hospital treatment of bleeding and perforated ulcers in a university hospital, from data in discharge letters and the hospital management information system. Eligible patients had been treated in the VU University Medical Center between January 1997 and August 2000 for an ulcer bleed or perforation (International Classification of Diseases code 531-4). Resource use comprised hospitalization days and diagnostic and therapeutic interventions. Insurance claim prices determined the costs from the payers' perspective. In a secondary analysis we excluded resource use that was clearly related to the treatment of comorbid illness. Fifty-three patients with a bleeding (n = 35) or perforated ulcer (n = 15) or both (n = 3) were studied, including 14 with comorbidity; 22 complications occurred in the stomach, 29 in the duodenum, one in both stomach and duodenum, and one after partial gastrectomy. A simultaneous bleed and perforation was most expensive (26,000 euro), followed by perforation (19,000 euro) and bleeding (12,000 euro). A bleed in the duodenum was more expensive than in the stomach (13,000 euro vs 10,000 euro), while the opposite was seen for perforations (13,000 euro vs 21,000 euro). Comorbidity increased costs substantially: even after correction for procedures unrelated to the ulcer complication, comorbidity more than doubled the costs of treatment. Treatment of complicated ulcers is expensive, especially in patients with comorbid conditions.

  4. Perforated Gastric Ulcer Associated with Anti-Angiogenic Therapy

    Directory of Open Access Journals (Sweden)

    Diogo Libânio

    2017-08-01

    Full Text Available Anti-angiogenic therapy with bevacizumab, an inhibitor of vascular endothelial growth factor, is commonly used in metastatic colorectal cancer and is rarely associated with gastrointestinal perforation, perforation being more frequent in the primary tumor site or at the anastomotic level. We present the case of a 64-year-old male with stage IV rectal adenocarcinoma who was on palliative chemotherapy with FOLFOX and bevacizumab. After the 4th chemotherapy cycle, our patient started fever and epigastric pain. He was hemodynamically stable, and signs of peritoneal irritation were absent. There were no alterations in the abdominal X-ray, and C-reactive protein was markedly elevated. A CT scan revealed a de novo thickness in the gastric antrum. Upper digestive endoscopy showed an ulcerated 40-mm lesion in the angulus, with a 20-mm orifice communicating with an exsudative cavity revested by the omentum. A conservative approach was decided including fasting, broad-spectrum intravenous antibiotics, and proton-pump inhibitors. Subsequent gastroduodenal series showed no contrast extravasation, allowing the resumption of oral nutrition. Esophagogastroduodenoscopy after 8 weeks showed perforation closure. Biopsies did not show neoplastic cells or Heliobacter pylori infection. Although the success in the conservative management of perforation allowing the maintenance of palliative chemotherapy (without bevacizumab, the patient died after 4 months due to liver failure. The reported case shows an uncommon endoscopic finding due to a rare complication of anti-angiogenic therapy. Additionally, it reminds clinicians that a history of gastroduodenal ulcers should be actively sought before starting anti-angiogenic treatment and that suspicion for perforation should be high in these cases.

  5. Nickel Electroless Plating: Adhesion Analysis for Mono-Type Crystalline Silicon Solar Cells.

    Science.gov (United States)

    Shin, Eun Gu; Rehman, Atteq ur; Lee, Sang Hee; Lee, Soo Hong

    2015-10-01

    The adhesion of the front electrodes to silicon substrate is the most important parameters to be optimized. Nickel silicide which is formed by sintering process using a silicon substrate improves the mechanical and electrical properties as well as act as diffusion barrier for copper. In this experiment p-type mono-crystalline czochralski (CZ) silicon wafers having resistivity of 1.5 Ω·cm were used to study one step and two step nickel electroless plating process. POCl3 diffusion process was performed to form the emitter with the sheet resistance of 70 ohm/sq. The Six, layer was set down as an antireflection coating (ARC) layer at emitter surface by plasma enhanced chemical vapor deposition (PECVD) process. Laser ablation process was used to open SiNx passivation layer locally for the formation of the front electrodes. Nickel was deposited by electroless plating process by one step and two step nickel electroless deposition process. The two step nickel plating was performed by applying a second nickel deposition step subsequent to the first sintering process. Furthermore, the adhesion analysis for both one step and two steps process was conducted using peel force tester (universal testing machine, H5KT) after depositing Cu contact by light induced plating (LIP).

  6. Performance of a parallel plate volume cell prototype for a fast iron/gas calorimeter

    International Nuclear Information System (INIS)

    Bizzeti, A.; Civinini, C.; D'alessandro, R.; Ferrando, A.

    1993-01-01

    We present the first test of the application of the parallel plate chamber principles for the design of a very fast and radiation-hard iron/gas sampling calorimeter, suitable for very forward regions in detectors for LBC; based on the use of thick iron plates as electrodes. We have built a one cell prototype consisting of three parallel thick iron plates (117 mn each). Results on efficiencies and mean collected charge for minimum ionizing particles with different gases are presented. (Author)

  7. Performance of a parallel plate volume cell prototype for a fast iron/gas calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Bizzeti, A.; Civinini, C.; D' Alessandro, R.; Ferrando, A.; Malinin, A.; Martinez-Laso, L.; Pojidaev, V.

    1993-07-01

    We present the first test of the application of the parallel plate chamber principles for the design of a very fast and radiation-hard iron/gas sampling calorimeter, suitable for very forward regions in detectors for LHC, based on the use of thick iron plates as electrodes. We have built a one cell prototype consisting of three parallel thick iron plates (17 mm each). Results on efficiencies and mean collected charge for minimum ionizing particles with different gases are presented. (Author) 7 refs.

  8. Performance of a parallel plate volume cell prototype for a fast iron/gas calorimeter

    International Nuclear Information System (INIS)

    Bizzeti, A.; Civinini, C.; D'Alessandro, R.; Ferrando, A.; Malinin, A.; Martinez-Laso, L.; Pojidaev, V.

    1993-01-01

    We present the first test of the application of the parallel plate chamber principles for the design of a very fast and radiation-hard iron/gas sampling calorimeter, suitable for very forward regions in detectors for LHC, based on the use of thick iron plates as electrodes. We have built a one cell prototype consisting of three parallel thick iron plates (17 mm each). Results on efficiencies and mean collected charge for minimum ionizing particles with different gases are presented. (Author) 7 refs

  9. Conservative Management of Colonoscopic Perforation: A Case Report.

    Science.gov (United States)

    Parsa, Hossein; Miroliaee, Arash; Doagoo, Zafar; Sina, Saeed

    2017-07-01

    Colonoscopy is widely used for the diagnosis, treatment and a follow up of colorectal diseases. Perforation of the large bowel during elective colonoscopy is rare but serious life threatening complication. We report a 51-year-old woman who experienced recto sigmoid perforation during diagnostic colonoscopy. During 8 days of total hospitalization, she spent 3 days in ICU with gastrointestinal rest. The patient was hydrated and took intravenous antibiotics. In take-output and temperature were closely monitored. Serial abdominal examinations were performed to rule out peritonitis. After transferring to surgery ward in the day 4, liquid diet started slowly, and she was ambulated. At the day 8, she was discharged with the good clinical condition. Conservative management of the patients with early diagnosis of perforation and no signs and symptoms of peritonitis or sepsis could be the modality of choice.

  10. Primary tubercular caecal perforation: a rare clinical entity

    Directory of Open Access Journals (Sweden)

    Moses Sonia

    2010-03-01

    Full Text Available Abstract Background Intestinal tuberculosis is a common problem in endemic areas, causing considerable morbidity and mortality. An isolated primary caecal perforation of tubercular origin is exceptionally uncommon. Case presentation We report the case of a 39 year old male who presented with features of perforation peritonitis, which on laparotomy revealed a caecal perforation with a dusky appendix. A standard right hemicolectomy with ileostomy and peritoneal toileting was done. Histopathology revealed multiple transmural caseating granulomas with Langerhans-type giant cells and acid-fast bacilli, consistent with tuberculosis, present only in the caecum. Conclusions We report this extremely rare presentation of primary caecal tuberculosis to sensitize the medical fraternity to its rare occurrence, which will be of paramount importance owing to the increasing incidence of tuberculosis all over the world, especially among the developing countries.

  11. Perforated peptic ulcer in Tikur Anbessa Hospital: a review of 74 cases.

    Science.gov (United States)

    Ersumo, Tessema; W/Meskel, Yidnekachew; Kotisso, Berhanu

    2005-01-01

    Little is known on the pattern of perforated peptic ulcer in Ethiopia. To evaluate the early, outcome of management, a five-year retrospective analysis of 74 operated cases of perforated peptic ulcer was undertaken. Perforated peptic ulcer accounted for 3.4% of the adult emergency surgical procedures. The mean age was 32.6 years, with a male to female ratio of 7.2 to 1.0. Fifty-six percent of the cases were unmarried. In nearly 22.0% of the patients, no previous history of peptic ulcer disease was documented. Delay in diagnosis was noted in 95% of the cases. Most patients had duodenal ulcer perforation, and about 78% had purulent peritonitis at laparotomy. Fourteen died in hospital. Early presentation of patients to surgical care facilities may reduce morbidity and mortality in cases of peptic ulcer perforation.

  12. Giant trochanteric pressure sore: Use of a pedicled chimeric perforator flap for cover

    Directory of Open Access Journals (Sweden)

    Mehrotra Sandeep

    2009-01-01

    Full Text Available Pressure sores are increasing in frequency commensurate with an ageing population with multi-system disorders and trauma. Numerous classic options are described for providing stable wound cover. With the burgeoning knowledge on perforator anatomy, recent approaches focus on the use of perforator-based flaps in bedsore surgery. A giant neglected trochanteric pressure sore in a paraplegic is presented. Since conventional options of reconstruction appeared remote, the massive ulcer was successfully managed by a chimeric perforator-based flap. The combined muscle and fasciocutaneous flaps were raised as separate paddles based on the anterolateral thigh perforator branches and provided stable cover without complications. Perforators allow versatility in managing complex wounds without compromising on established principles.

  13. Effects of carbon additives on the performance of negative electrode of lead-carbon battery

    International Nuclear Information System (INIS)

    Zou, Xianping; Kang, Zongxuan; Shu, Dong; Liao, Yuqing; Gong, Yibin; He, Chun; Hao, Junnan; Zhong, Yayun

    2015-01-01

    Highlights: • The negative electrode sheets are prepared by simulating manufacture condition of negative plates. • The effect of carbon additives on negative electrode sheets is studied by electrochemical method. • Carbon additives in NAM enhance electrochemical properties of the negative sheets. • The negative sheets with 0.5 wt% carbon additive exhibit better electrochemical performance. • The charge-discharge mechanism is discussed in detail according to the experimental results. - Abstract: In this study, carbon additives such as activated carbon (AC) and carbon black (CB) are introduced to the negative electrode to improve its electrochemical performance, the negative electrode sheets are prepared by simulating the negative plate manufacturing process of lead-acid battery, the types and contents of carbon additives in the negative electrode sheets are investigated in detail for the application of lead-carbon battery. The electrochemical performance of negative electrode sheets are measured by chronopotentiometry, galvanostatic charge-discharge and electrochemical impedance spectroscopy, the crystal structure and morphology are characterized by X-ray diffraction and scanning electron microscopy, respectively. The experimental results indicate that the appropriate addition of AC or CB can enhance the discharge capacity and prolong the cycle life of negative electrode sheets under high-rate partial-state-of-charge conditions, AC additive exerts more obvious effect than CB additive, the optimum contents for the best electrochemical performance of the negative electrode sheets are determined as 0.5wt% for both AC and CB. The reaction mechanism of the electrochemical process is also discussed in this paper, the appropriate addition of AC or CB in negative electrode can promote the conversion of PbSO 4 to Pb, suppress the sulfation of negative electrode sheets and reduce the electrochemical reaction resistance

  14. Diagnosing perforated appendicitis in pediatric patients: a new model.

    Science.gov (United States)

    van den Bogaard, Veerle A B; Euser, Sjoerd M; van der Ploeg, Tjeerd; de Korte, Niels; Sanders, Dave G M; de Winter, Derek; Vergroesen, Diederik; van Groningen, Krijn; de Winter, Peter

    2016-03-01

    Studies have investigated sensitivity and specificity of symptoms and tests for diagnosing appendicitis in children. Less is known with regard to the predictive value of these symptoms and tests with respect to the severity of appendicitis. The aim of this study was to determine the predictive value of patient's characteristics and tests for discriminating between perforated and nonperforated appendicitis in children. Pediatric patients who underwent an appendectomy at Spaarne Hospital Hoofddorp, the Netherlands, between January 1, 2009 and December 31, 2013, were included. Baseline patient's characteristics, history, physical examination, laboratory data and results of ultrasounds were collected. Univariate and multivariate logistic regressions were used to determine predictors of perforation. In total, 375 patients were included in this study of which 97 children (25.9%) had significant signs of perforation. Univariate analysis showed that age, duration of complaints, temperature, vomiting, CRP, WBC, different findings on ultrasound and the diameter of the appendix were good predictors of a perforated appendicitis. The final multivariate prediction model included temperature, CRP, clearly visible appendix and free fluids on ultrasound and diameter of the appendix and resulted in an area under the curve (AUC) of 0.91 showing sensitivity and specificity of respectively 85.2% and 81.2%. This prediction model can be used for identification of 'high-risk' children for a perforated appendicitis and might be helpful to prevent complications and longer hospitalization by bringing these children to theater earlier. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Using perforators as recipient vessels (supermicrosurgery) for free flap reconstruction of the knee region.

    Science.gov (United States)

    Hong, Joon Pio; Koshima, Isao

    2010-03-01

    The purpose of this article is to evaluate the feasibility of a perforator as a recipient vessel to reconstruct soft tissue defects of the knee region.From December of 2006 to August of 2008, total of 25 patients underwent reconstructive procedure using either an anterolateral thigh or an upper medial thigh perforator flap. The flaps were anastomosed in a perforator to perforator manner using supermicrosurgery technique.Minimum of 3 perforators were traced around the knee defect. All flaps survived attached to a recipient perforator with artery diameter ranging from 0.4 to 0.9 mm and accompanying veins ranging from 0.4 to 1.2 mm. This approach allowed reduction in time for pedicle and recipient vessel dissection and minimized the trauma involved during isolation of the vessels.Using the perforator as recipient vessel allows an increase in selection for choice of recipient. By using a perforator as recipient, less time is consumed to secure the vessel, does not need long pedicles for flap, is not bound by the condition of major arteries, and minimizes any risk for major vessel injury while having acceptable flap survival.

  16. Controlled electroplating and electromigration in nickel electrodes for nanogap formation

    Energy Technology Data Exchange (ETDEWEB)

    De Los Santos Valladares, Luis; Mitrelias, Thanos; Sfigakis, Francois; Barnes, Crispin H W [Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Leon Felix, Lizbet; Bustamante Dominguez, Angel [Laboratorio de Ceramicos y Nanomateriales, Universidad Nacional Mayor de San Marcos, Ap. Postal 14-0149, Lima (Peru); Khondaker, Saiful I [NanoScience Technology Center and Department of Physics, University of Central Florida, Orlando, FL 32826 (United States); Majima, Yutaka, E-mail: ld301@cam.ac.uk, E-mail: luisitodv@yahoo.es [Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8503 (Japan)

    2010-11-05

    We report the fabrication of nickel nanospaced electrodes by electroplating and electromigration for nanoelectronic devices. Using a conventional electrochemical cell, nanogaps can be obtained by controlling the plating time alone and after a careful optimization of electrodeposition parameters such as electrolyte bath, applied potential, cleaning, etc. During the process, the gap width decreases exponentially with time until the electrode gaps are completely bridged. Once the bridge is formed, the ex situ electromigration technique can reopen the nanogap. When the gap is {approx} 1 nm, tunneling current-voltage characterization shows asymmetry which can be corrected by an external magnetic field. This suggests that charge transfer in the nickel electrodes depends on the orientation of magnetic moments.

  17. Controlled electroplating and electromigration in nickel electrodes for nanogap formation

    International Nuclear Information System (INIS)

    De Los Santos Valladares, Luis; Mitrelias, Thanos; Sfigakis, Francois; Barnes, Crispin H W; Leon Felix, Lizbet; Bustamante Dominguez, Angel; Khondaker, Saiful I; Majima, Yutaka

    2010-01-01

    We report the fabrication of nickel nanospaced electrodes by electroplating and electromigration for nanoelectronic devices. Using a conventional electrochemical cell, nanogaps can be obtained by controlling the plating time alone and after a careful optimization of electrodeposition parameters such as electrolyte bath, applied potential, cleaning, etc. During the process, the gap width decreases exponentially with time until the electrode gaps are completely bridged. Once the bridge is formed, the ex situ electromigration technique can reopen the nanogap. When the gap is ∼ 1 nm, tunneling current-voltage characterization shows asymmetry which can be corrected by an external magnetic field. This suggests that charge transfer in the nickel electrodes depends on the orientation of magnetic moments.

  18. The Electrode Modality Development in Pulsed Electric Field Treatment Facilitates Biocellular Mechanism Study and Improves Cancer Ablation Efficacy.

    Science.gov (United States)

    Cen, Chao; Chen, Xinhua

    2017-01-01

    Pulsed electric field treatment is now widely used in diverse biological and medical applications: gene delivery, electrochemotherapy, and cancer therapy. This minimally invasive technique has several advantages over traditional ablation techniques, such as nonthermal elimination and blood vessel spare effect. Different electrodes are subsequently developed for a specific treatment purpose. Here, we provide a systematic review of electrode modality development in pulsed electric field treatment. For electrodes invented for experiment in vitro, sheet electrode and electrode cuvette, electrodes with high-speed fluorescence imaging system, electrodes with patch-clamp, and electrodes with confocal laser scanning microscopy are introduced. For electrodes invented for experiment in vivo, monopolar electrodes, five-needle array electrodes, single-needle bipolar electrode, parallel plate electrodes, and suction electrode are introduced. The pulsed electric field provides a promising treatment for cancer.

  19. Electrochemical oxidation of phenol in a parallel plate reactor using ruthenium mixed metal oxide electrode

    Energy Technology Data Exchange (ETDEWEB)

    Yavuz, Yusuf [Anadolu Universitesi, Cevre Sor. Uyg. ve Aras. Merkezi, Eskisehir (Turkey); Koparal, A. Savas [Anadolu Universitesi, Cevre Sor. Uyg. ve Aras. Merkezi, Eskisehir (Turkey)]. E-mail: askopara@anadolu.edu.tr

    2006-08-21

    In this study, electrochemical oxidation of phenol was carried out in a parallel plate reactor using ruthenium mixed metal oxide electrode. The effects of initial pH, temperature, supporting electrolyte concentration, current density, flow rate and initial phenol concentration on the removal efficiency were investigated. Model wastewater prepared with distilled water and phenol, was recirculated to the electrochemical reactor by a peristaltic pump. Sodium sulfate was used as supporting electrolyte. The Microtox'' (registered) bioassay was also used to measure the toxicity of the model wastewater during the study. As a result of the study, removal efficiency of 99.7% and 88.9% were achieved for the initial phenol concentration of 200 mg/L and chemical oxygen demand (COD) of 480 mg/L, respectively. In the same study, specific energy consumption of 1.88 kWh/g phenol removed and, mass transfer coefficient of 8.62 x 10{sup -6} m/s were reached at the current density of 15 mA/cm{sup 2}. Electrochemical oxygen demand (EOD), which can be defined as the amount of electrochemically formed oxygen used for the oxidation of organic pollutants, was 2.13 g O{sub 2}/g phenol. Electrochemical oxidation of petroleum refinery wastewater was also studied at the optimum experimental conditions obtained. Phenol removal of 94.5% and COD removal of 70.1% were reached at the current density of 20 mA/cm{sup 2} for the petroleum refinery wastewater.

  20. Typhoid ileal perforation: a 13-year experience

    Directory of Open Access Journals (Sweden)

    Poras Chaudhary

    2015-07-01

    Full Text Available Typhoid fever is endemic in many developing countries with a high rate of complications. Aim of this study is to analyse epidemiological features, clinical presentations, complications and therapeutic outcomes of enteric perforation peritonitis diagnosed and treated in our hospital. Records of total number of 646 patients, who presented with perforation peritonitis due to enteric fever in the surgical emergency unit of Dr Ram Manohar Lohia hospital, New Delhi between January 2001 and December 2013, were reviewed retrospectively. Descriptive statistics was used to analyze the data. Out of 646 patients, 62 (9.59% presented in shock. Stomal, peristomal, local and systemic complications were high in these patients. Primary closure was done in 212 (33.12 patients, primary ileostomy was created in 410 (64.06 patients, and resection and anastomosis was done in 24 (3.75 patients. Thirteen patients (2.01% died of typhoid intestinal perforation. To prevent complications of typhoid fever, in addition to control sanitation, it is also important to control quackery and malpractices. Awareness and education about the disease, its nature and complications will also be of great help.

  1. Influence of delays on perforation risk in adults with acute appendicitis.

    LENUS (Irish Health Repository)

    Kearney, D

    2012-02-03

    PURPOSE: This study analyzed whether prehospital or in-hospital delay was the more significant influence on perforation rates for acute appendicitis and whether any clinical feature designated patients requiring higher surgical priority. METHODS: A retrospective analysis was conducted over one year at a tertiary referral hospital without a dedicated emergency surgical theater. Admission notes, theater logbook, and the Hospital Inpatient Enquiry system were reviewed to identify the characteristics and clinical course of patients aged greater than 16 years who were operated upon for histologically confirmed acute appendicitis. RESULTS: One hundred and fifteen patients were studied. The overall perforation rate was 17 percent. The mean duration of symptoms prior to hospital presentation was 38.1 hours with the mean in-hospital waiting time prior to operation being 23.4 hours. Although body temperature on presentation was significantly greater in patients found to have perforated appendicitis (P < 0.05), only patient heart rate at presentation and overall duration of symptoms, but not in-hospital waiting time, independently predicted perforation by stepwise linear regression modeling. CONCLUSION: In-hospital delay was not an independent predictor of perforation in adults with acute appendicitis although delays may contribute if patients are left to wait unduly. Tachycardia at presentation may be a quantifiable feature of those more likely to have perforation and who should be given higher surgical priority.

  2. [Reconstruction of ankle and foot with combination of free perforator flaps and skin graft].

    Science.gov (United States)

    Yin, Lu; Gong, Ketong; Yin, Zhonggang; Zhang, Bo; Xu, Jianhua

    2017-03-01

    To evaluate the clinical outcomes of free perforator flaps combined with skin graft for reconstruction of ankle and foot soft tissue defects. Between June 2014 and October 2015, 20 cases of ankle and foot soft tissue defects were treated. There were 16 males and 4 females, aged from 19 to 61 years (mean, 43.3 years). Injury was caused by traffic accident in 7 cases, by crashing in 9 cases, and machine twist in 4 cases. The locations were the ankle in 6 cases, the heel in 3 cases, the dorsum pedis in 4 cases, and the plantar forefoot in 7 cases of avulsion injury after toes amputation. The size of wound ranged from 15 cm×10 cm to 27 cm×18 cm. The time from injury to treatment was from 11 to 52 days (mean, 27 days). The anterolateral thigh perforator flap was used in 11 cases, thoracodorsal antery perforator flap in 3 cases, medial sural artery perforator flap in 4 cases, deep inferior epigastric perforator flap in 1 case, and anteromedial thigh perforator flap in 1 case, including 5 chimeric perforator flaps, 5 polyfoliate perforator flaps, 3 flow-through perforator flaps, and 3 conjoined perforator flaps. The size of the perforator flap ranged from 10.0 cm×6.5 cm to 36.0 cm×8.0 cm, the size of skin graft from 5 cm×3 cm to 18 cm×12 cm. Venous crisis occurred in 2 flaps which survived after symptomatic treatment; 18 flaps survived successfully and skin grafting healed well. The follow-up time ranged 4-18 months (mean, 8.3 months). The flaps had good appearance, texture and color, without infection. The patients could walk normally and do daily activities. Only linear scars were observed at the donor sites. Free perforator flap can be used to reconstruct defects in the ankle and foot, especially in the weight-bearing area of the plantar forefoot. A combination of free perforator flap and skin graft is ideal in reconstruction of great soft tissue defects in the ankle and foot.

  3. Perforation in a patient with stercoral colitis and diverticulosis: who did it?

    Directory of Open Access Journals (Sweden)

    Vijaya R. Bhatt

    2014-02-01

    Full Text Available Stercoral colitis with perforation of the colon is an uncommon, yet life-threatening cause of the acute abdomen. No one defining symptom exists for stercoral colitis; it may present asymptomatically or with vague symptoms. Diagnostic delay may result in perforation of the colon resulting in complications, even death. Moreover, stercoral perforation of the colon can also present with localized left lower quadrant abdominal pain masquerading as diverticulitis. Diverticular diseases and stercoral colitis share similar pathophysiology; furthermore, they may coexist, further complicating the diagnostic dilemma. The ability to decide the cause of perforation in a patient with both stercoral colitis and diverticulosis has not been discussed. We, therefore, report this case of stercoral perforation in a patient with diverticulosis and include a discussion of the epidemiology, clinical presentation, and a review of helpful diagnostic clues for a rapid differentiation to allow for accurate diagnosis and treatment.

  4. [An Analysis of Perforated Gastric Cancer with Acute Peritonitis in Our Hospital].

    Science.gov (United States)

    Adachi, Shinichi; Endo, Shunji; Chinen, Yoshinao; Itakura, Hiroaki; Takayama, Hirotoshi; Tsuda, Yujiro; Ueda, Masami; Nakashima, Shinsuke; Ohta, Katsuya; Ikenaga, Masakazu; Yamada, Terumasa

    2018-01-01

    Perforated gastric cancer is relatively rare and the incidence is reported about 1% of all the cases of gastric cancer. We retrospectively analyzed the clinical data of the consecutive 12 patients with perforated gastric cancer who underwent operation in our hospital between January 2005 and December 2016. There were 5 men and 7 women, with an average age of 65.8 years old(34-87). Perforated gastric cancer occurred in the region U(1 cases), M(6 cases), L(5 cases). There were 11 cases with distant metastasis. We could successfully diagnosed as perforated gastric cancer in 8 cases before emergency operation. Gastrectomy was performed in 5 cases. However, the curative resection was performed only 1 case. Prognosis of perforated gastric cancer is poor. We considered as an appropriate two-step surgical strategy that the first step of surgery is an acute peritonitis treatment followed by radical gastrectomy with lymphadenectomy.

  5. Preoperative CT angiography reduces surgery time in perforator flap reconstruction

    NARCIS (Netherlands)

    Smit, Jeroen M.; Dimopoulou, Angeliki; Liss, Anders G.; Zeebregts, Clark J.; Kildal, Morten; Whitaker, Iain S.; Magnusson, Anders; Acosta, Rafael

    The use of perforator flaps in breast reconstructions has increased considerably in the past decade. A disadvantage of the perforator flap is difficult dissection, which results in a longer procedure. During spring 2006, we introduced CT angiography (CTA) as part of the diagnostic work-up in

  6. Perforation af rectum med faekal peritonitis efter staplet haemorideoperation

    DEFF Research Database (Denmark)

    Beuke, Anna-Christina; Pedersen, Mark Ellebaek; Qvist, Niels

    2008-01-01

    Rectal perforation and faecal peritonitis after stapled operation for grade IV haemorrhoids is described. The complication is rare, but surgeons performing the procedure must be familiar with potential risk factors.......Rectal perforation and faecal peritonitis after stapled operation for grade IV haemorrhoids is described. The complication is rare, but surgeons performing the procedure must be familiar with potential risk factors....

  7. Electroplating Ni-63 metal ions in chloride bath on the Cu-plate

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Kwon Mo; Uhm, Young Rang; Son, Kwang Jae; Park, Keun Yung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    Ni-63 plating is similar to other electroplating processes that employ soluble metal anodes. The nickel plating solution described by Watts in 1916 eventually replaced all other strategies in use up to that time. Charged Ni ions are formed by sulfate, sulfamate, chloride, and a Watts bath. However, charged Ni-63 ions are formed by dissolving metal Ni-63. Specifically, it requires the passage of direct current (DC) between two electrodes that are immersed in a conductive, aqueous solution of nickel salts. The flow of a DC causes one of the electrodes (the anode) to dissolve and the other electrode (the cathode) to become covered with nickel. The nickel in the solution is present in the form of divalent positively charged ions (Ni{sup 2+}). When the current flows, the positive ions react with two electrons (2e{sup -}) and are converted into metallic nickel (Ni{sup 0}) at the cathode surface. In the present study, we optimize and established process for the electroplating Ni-63 on Cu-plate. Nanocrystalline nickel (Ni) coatings were synthesized by DC electro deposition at a current density of 15 mA/cm{sup 2}. The bath was primarily composed of 0.2 M Ni ions, prepared by dissolving Ni-63 metal particles in HCl. The prototype for electroplating radioactive Ni-63 has been established. The electroplating was carried out by two-step processes such as preparation of ionic solution including Ni-63, and coating processes on the substrate.

  8. Electroplating Ni-63 metal ions in chloride bath on the Cu-plate

    International Nuclear Information System (INIS)

    Yoo, Kwon Mo; Uhm, Young Rang; Son, Kwang Jae; Park, Keun Yung

    2014-01-01

    Ni-63 plating is similar to other electroplating processes that employ soluble metal anodes. The nickel plating solution described by Watts in 1916 eventually replaced all other strategies in use up to that time. Charged Ni ions are formed by sulfate, sulfamate, chloride, and a Watts bath. However, charged Ni-63 ions are formed by dissolving metal Ni-63. Specifically, it requires the passage of direct current (DC) between two electrodes that are immersed in a conductive, aqueous solution of nickel salts. The flow of a DC causes one of the electrodes (the anode) to dissolve and the other electrode (the cathode) to become covered with nickel. The nickel in the solution is present in the form of divalent positively charged ions (Ni 2+ ). When the current flows, the positive ions react with two electrons (2e - ) and are converted into metallic nickel (Ni 0 ) at the cathode surface. In the present study, we optimize and established process for the electroplating Ni-63 on Cu-plate. Nanocrystalline nickel (Ni) coatings were synthesized by DC electro deposition at a current density of 15 mA/cm 2 . The bath was primarily composed of 0.2 M Ni ions, prepared by dissolving Ni-63 metal particles in HCl. The prototype for electroplating radioactive Ni-63 has been established. The electroplating was carried out by two-step processes such as preparation of ionic solution including Ni-63, and coating processes on the substrate

  9. A Case Report of Stercoraceous Perforation of the Cecum due to Scybalum

    Directory of Open Access Journals (Sweden)

    HR Khorshidi

    2006-10-01

    Introduction & Objective: Non-traumatic colon perforations are usually caused by malignancy, diverticulum and colitis. Stercoraceous perforation of the colon has rarely been reported in the literature. This lesion is assumed to be produced by the pressure from a hard scybalum resulting in a perforated ulcer with necrotic edges. We report a case of stercoraceous perforation of the cecum due to scybalum. Case: We report a 50-year-old man who had a severe abdominal pain from 3 days ago and had peritonitis in physical exam. He was admitted in Mars, 2005 at Mobasher Kashani Hospital in Hamadan and he was parapelegic from 8 months ago due to trauma in his medical history and then he had severe and chronic constipation that necessitated the use of cathartic drugs. We operated him with diagnosis of peritonitis, and perforation of cecum due to scybalum was seen and right hemicolectomy and colostomy and ileostomy was done. Conclusion: The most common site of colon perforation due to scybalum is rectosigmoid area and cecal perforation is a rare area in the literature. It is presented with peritonitis in old patients that have chronic constipation. It is difficult to diagnose this lesion preoperatively. This lesion was only 11% correctly diagnosed before operation and should be always suspected when a patient with chronic constipation suffers from sudden abdominal pain. Resection and colostomy is the treatment of choice in most situations.

  10. Surgical management of perforated peptic ulcer disease.

    Science.gov (United States)

    Sweeney, K J; Faolain, M O; Gannon, D; Gorey, T F; Kerin, M J

    2006-01-01

    Surgery for perforated peptic ulcer disease is one of the most common emergency procedures carried out in the western world. The role of postoperative empiric Helicobacter Pylori eradication therapy is controversial. The clinical, operative and postoperative surveillance details of 84 consecutive patients who underwent surgery for perforated peptic ulcer were reviewed. All patients underwent omentopexy +/- simple closure followed by proton pump therapy. Patients were followed-up for an average of 44 +/- 19 months. Females were older than male patients (59 +/- 20 vs. 46 + 17 years; pperforated peptic ulcer is associated with a significant perioperative mortality rate. Elderly female patients are particularly at risk.

  11. Non-operative management of perforated peptic ulcer

    International Nuclear Information System (INIS)

    Rahman, M.M.; Ahsan, H.N.; Hossain, M.D.

    2003-01-01

    Objective: The aim of this study was to see the morbidity and mortality in peptic ulcer perforation cases by non-operative management in selected cases. Results: In the selected 54 patients, male: female were 49:05. Nine had history of NSAID intake. There was no mortality. Morbidity analysis showed that three had hepatic abscess, four had pelvic abscess, six took prolonged time for improvement, in two cases conservative treatment had to be abandoned and laparotomy was done in the same hospital admission. Conclusion: Non-operative procedure is a safe and effective measure for the management of perforated peptic ulcer in selected cases. (author)

  12. Acute spontaneous gastric perforation in neonates: A report of three ...

    African Journals Online (AJOL)

    Gastric perforation in neonates is a rare, serious and life-threatening problem. The precise aetiology is obscure in most cases. By virtue of its high mortality rate, it requires prompt recognition and surgical intervention. We report three cases of neonatal gastric perforation managed by early resuscitation and primary repair.

  13. Perforated gastric and duodenal ulcers in an urban African population

    African Journals Online (AJOL)

    Background: Perforations of the stomach and duodenum are frequent causes of acute generalized peritonitis in our environment. This is a prospective study of 331 cases of gastric and duodenal perforations. Study design: A consecutive series of adult patients admitted and treated for acute generalized peritonitis due to ...

  14. The "stamp method" : a new treatment for perforated peptic ulcer?

    NARCIS (Netherlands)

    Bertleff, M.J.O.E.; Liem, RSB; Robinson, PH; Bonjer, HJ; Lange, J. F.; Bartels, H.; van der Werf, J.F.A.

    Background: The aim of this study was to develop a simple method for closure of a perforated peptic ulcer, making it more accessible for laparoscopic surgery. Methods: An experimental pilot study was performed using five male Wistar rats. The perforation was closed by a bioabsorbable patch made of

  15. Percutaneous drainage in conservative therapy for perforated gastroduodenal ulcers.

    Science.gov (United States)

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

    2012-01-01

    The management of peptic ulcers has dramatically changed and the incidence of elective surgery for gastroduodenal peptic ulcers has markedly decreased; hence, the incidence of emergency surgery for perforated peptic ulcers has slightly increased. In select cases, conservative therapy can be used as an alternative for treating perforated gastroduodenal ulcers. In this study, we evaluated the efficacy of percutaneous abdominal drainage for the conservative treatment of perforated gastroduodenal ulcers. We retrospectively studied 51 patients who had undergone conservative therapy for perforated gastroduodenal ulcers. These patients were divided into 2 groups on the basis of the initial treatment with conservative therapy with or without percutaneous drainage: group PD included patients who had undergone percutaneous drainage and group NPD, patients who had undergone non-percutaneous drainage. In the PD group, 14.3% (n=3) of the patients did not respond to conservative therapy, while this value was 43.3% (n=13) in the NPD group. The 2 groups differed significantly with respect to conversion from conservative therapy to surgery (pperforated gastroduodenal ulcers should be performed only in the case of patients meeting the required criteria; its combination with percutaneous intraperitoneal drainage is effective as initial conservative therapy.

  16. Influence of perforation erosion on multiple growing hydraulic fractures in multi-stage fracturing

    Directory of Open Access Journals (Sweden)

    Yongming Li

    2018-02-01

    Full Text Available In multi-stage hydraulic fracturing, the limited-entry method is widely used to promote uniform growth of multiple fractures. However, this method's effectiveness may be lost because the perforations will be eroded gradually during the fracturing period. In order to study the influence of perforation erosion on multiple growing hydraulic fractures, we combined the solid–fluid coupled model of hydraulic fracture growth with an empirical model of perforation erosion to implement numerical simulation. The simulations show clearly that the erosion of perforation will significantly deteriorate the non-uniform growth of multiple fractures. Based on the numerical model, we also studied the influences of proppant concentration and injection rates on perforation erosion in multi-stage hydraulic fracturing. The results indicate that the initial erosion rates become higher with the rising proppant concentration, but the growth of multiple hydraulic fractures is not sensitive to the varied proppant concentration. In addition, higher injection rates are beneficial significantly to the limited-entry design, leading to more uniform growth of fractures. Thus, in multi-stage hydraulic fracturing enough high injection rates are proposed to keep uniform growths. Keywords: Unconventional oil and gas reservoir, Horizontal well, Perforation friction, Perforation erosion, Multi-stage hydraulic fracturing, Numerical simulation, Mathematic model, Uniform growth of fractures

  17. Numerical analysis of AC tungsten inert gas welding of aluminum plate in consideration of oxide layer cleaning

    Energy Technology Data Exchange (ETDEWEB)

    Tashiro, Shinichi, E-mail: tashiro@jwri.osaka-u.ac.jp; Miyata, Minoru; Tanaka, Manabu

    2011-08-01

    A unified numerical simulation model of AC TIG welding of the aluminum plate considering energy balance among the electrode, the arc and the base metal and employing an analytical model for calculating cleaning rate of the oxide layer has been developed for investigating heat transport properties and weld pool formation process in AC TIG welding of aluminum plate. As a result of this simulation, it was shown that although the heat flux from the arc onto the base metal increases in EN (Electrode Negative) phase due to the electron condensation, that in EP (Electrode Positive) phase conversely decreases because mainly of cooling caused by the electron emission. Furthermore, the validity of the simulation model was confirmed by comparing to experimental results such as the arc voltage, the area of cleaning zone and the shape of weld pool.

  18. Radiation-hard ceramic Resistive Plate Chambers for forward TOF and T0 systems

    Energy Technology Data Exchange (ETDEWEB)

    Akindinov, A., E-mail: Alexander.Akindinov@cern.ch [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Dreyer, J.; Fan, X.; Kämpfer, B. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Kiselev, S. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Kotte, R.; Garcia, A. Laso [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Malkevich, D. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Naumann, L. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Nedosekin, A.; Plotnikov, V. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Stach, D. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Sultanov, R.; Voloshin, K. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation)

    2017-02-11

    Resistive Plate Chambers with ceramic electrodes are the main candidates for a use in precise multi-channel timing systems operating in high-radiation conditions. We report the latest R&D results on these detectors aimed to meet the requirements of the forward T0 counter at the CBM experiment. RPC design, gas mixture, limits on the bulk resistivity of ceramic electrodes, efficiency, time resolution, counting rate capabilities and ageing test results are presented.

  19. Nickel–copper hybrid electrodes self-adhered onto a silicon wafer by supersonic cold-spray

    International Nuclear Information System (INIS)

    Lee, Jong-Gun; Kim, Do-Yeon; Kang, Byungjun; Kim, Donghwan; Song, Hee-eun; Kim, Jooyoung; Jung, Woonsuk; Lee, Dukhaeng; Al-Deyab, Salem S.; James, Scott C.; Yoon, Sam S.

    2015-01-01

    High-performance electrodes are fabricated through supersonic spraying of nickel and copper particles. These electrodes yield low specific resistivities, comparable to electrodes produced by screen-printed silver paste and light-induced plating. The appeal of this fabrication method is the low cost of copper and large area scalability of supersonic spray-coating techniques. The copper and nickel electrode was fabricated in the open air without any pre- or post-treatment. The spray-coated copper–nickel electrode was characterized by optical microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction, and energy dispersive spectroscopy. Although both SEM and TEM images confirmed voids trapped between flattened particles in the fabricated electrode, this electrode’s resistivity was order 10 −6 Ω cm, which is comparable to the bulk value for pure copper

  20. Biliary peritonitis due to gall bladder perforation after percutaneous nephrolithotomy

    Directory of Open Access Journals (Sweden)

    Nikhil Ranjan

    2015-01-01

    Full Text Available A 19-year-old male patient underwent right percutaneous nephrolithotomy (PNL for right renal 1.5 × 1.5 cm lower pole stone. The procedure was completed uneventfully with complete stone clearance. The patient developed peritonitis and shock 48 h after the procedure. Exploratory laparotomy revealed a large amount of bile in the abdomen along with three small perforations in the gall bladder (GB and one perforation in the caudate lobe of the liver. Retrograde cholecystectomy was performed but the patient did not recover and expired post-operatively. This case exemplifies the high mortality of GB perforation after PNL and the lack of early clinical signs.

  1. Intraoperative Tumor Perforation is Associated with Decreased 5-Year Survival in Colon Cancer

    DEFF Research Database (Denmark)

    Bundgaard, N S; Bendtsen, V O; Ingeholm, P

    2017-01-01

    BACKGROUND: It is a widely held belief that intraoperative tumor perforation in colon cancer impairs survival and causes local recurrence, although the prognostic importance remains unclear. AIM: The aim of this study was to assess the effect of unintended intraoperative tumor perforation...... on postoperative mortality and long-term survival. MATERIAL AND METHODS: This national cohort study was based on data from a prospectively maintained nationwide colorectal cancer database. We included 16,517 colon cancer patients who were resected with curative intent from 2001 to 2012. RESULTS: Intraoperative...... tumor perforation produced a significantly impaired 5-year survival of 40% compared to 64% in non-perforated colon cancer. Intraoperative tumor perforation was an independent risk factor for death, hazard ratio 1.63 (95% confidence interval: 1.4-1.94), with a significantly increased 90-day postoperative...

  2. Malrotation with midgut volvulus associated with perforated ileal duplication

    Directory of Open Access Journals (Sweden)

    Anand Pandey

    2013-01-01

    Full Text Available Duplication of the alimentary tract is an important surgical condition. It may occur anywhere in the gastrointestinal tract. An important complication of this entity is perforation of the normal or abnormal gut. Malrotation with midgut volvulus can be a surgical emergency. We present a patient, who presented as malrotation with midgut volvulus associated with perforated ileal duplication. The patient was successfully managed.

  3. Spontaneous bile duct perforation in an infant, managed with simple ...

    African Journals Online (AJOL)

    Spontaneous bile duct perforation is a very rare but important cause of surgical jaundice in pediatric patients and one of the most common causes of surgical jaundice during infancy after biliary atresia. Preoperative diagnosis may not be possible in most of the cases. The exact cause of the perforation remains unclear.

  4. Experience with Acute Perforated Duodenal Ulcer in a West African ...

    African Journals Online (AJOL)

    Plain chest x-rays demonstrated gas under the diaphragm in 21(65.6%) of the patients. After adequate resuscitation, all the patients underwent laparotomy where the abdomen was explored, the diagnosis of perforated duodenal ulcer was confirmed and 29(70.7%) had simple closure of the perforation with omentum (after ...

  5. Experimental Study on EHD Flow Transition in a Small Scale Wire-plate ESP

    Directory of Open Access Journals (Sweden)

    Wang Chuan

    2016-06-01

    Full Text Available The electrohydrodynamic (EHD flow induced by the corona discharge was experimentally investigated in an electrostatic precipitator (ESP. The ESP was a narrow horizontal Plexiglas box (1300 mm×60 mm×60 mm. The electrode set consisted of a single wire discharge electrode and two collecting aluminum plate electrodes. Particle Image Velocimetry (PIV method was used to visualize the EHD flow characteristics inside the ESP seeded with fine oil droplets. The influence of applied voltage (from 8 kV to 10 kV and primary gas flow (0.15 m/s, 0.2 m/s, 0.4 m/s on the EHD flow transition was elucidated through experimental analysis. The formation and transition of typical EHD flows from onset to the fully developed were described and explained. Experimental results showed that the EHD flow patterns change depends on the gas velocity and applied voltage. EHD flow starts with flow streamlines near collecting plates bending towards the wire electrode, forming two void regions. An oscillating jet forming the downstream appeared and moved towards the wire electrode as voltage increased. For higher velocities (≥0.2 m/s, the EHD transition became near wire phenomenon with a jet-like flow structure near the wire, forming a void region behind the wire and expanding as voltage increased. Fully developed EHD secondary flow in the form of counter-rotating vortices appeared upstream with high applied voltage.

  6. Ceramic microsieves: influence of perforation shape and distribution on flow resistance and membrane strength

    NARCIS (Netherlands)

    Kuiper, S.; Brink, R.; Nijdam, W.; Krijnen, Gijsbertus J.M.; Elwenspoek, Michael Curt

    2002-01-01

    Ceramic microsieves with slit-shaped perforations were compared to sieves with circular-shaped perforations, regarding flow resistance and membrane strength. Destructive tests show that the highest strength is obtained if the perforations are placed in a non-alternating pattern. Especially for

  7. Dependence of streamer density on electric field strength on positive electrode

    Science.gov (United States)

    Koki, Nakamura; Takahumi, Okuyama; Wang, Douyan; Takao, N.; Hidenori, Akiyama; Kumamoto University Collaboration

    2015-09-01

    Pulsed streamer discharge plasma, a type of non-thermal plasma, is known as generation method of reactive radicals and ozone and treatment of exhausted gas. From our previous research, the distance between electrodes has been considered a very important parameter for applications using pulsed streamer discharge. However, how the distance between electrodes affects the pulsed discharge hasn't been clarified. In this research, the propagation process of pulsed streamer discharge in a wire-plate electrode was observed using an ICCD camera for 4 electrodes having different distance between electrodes. The distance between electrodes was changeable at 45 mm, 40 mm, 35 mm, and 30 mm. The results show that, when the distance between electrodes was shortened, applied voltage with a pulse duration of 100 ns decreased from 80 to 60.3 kV. Conversely, discharge current increased from 149 to 190 A. Streamer head velocity became faster. On the other hand, Streamer head density at onset time of streamer head propagation didn't change. This is considered due to the electric field strength of streamer head at that time, in result, it was about 14 kV/mm under each distance between electrodes.

  8. Colorectal cancer with intestinal perforation - a retrospective analysis of treatment outcomes.

    Science.gov (United States)

    Banaszkiewicz, Zbigniew; Woda, Łukasz; Tojek, Krzysztof; Jarmocik, Paweł; Jawień, Arkadiusz

    2014-01-01

    Colorectal cancer (CRC) is one of the leading cause of death in European population. It progresses without any symptoms in the early stages or those clinical symptoms are very discrete. The aim of this study was a retrospective analysis of treatment outcomes in patients with colorectal cancer complicated with intestinal perforation. A retrospective analysis of patients urgently operated upon in our Division of General Surgery, because of large intestine perforation, from February 1993 to February 2013 has been made. Results were compared with a group of patients undergoing the elective surgery for colorectal cancer in the same time and Division. Intestinal perforation occurred more often in males (6.52% vs. 6.03%), patients with mucous component in histopathological examination (9.09% vs. 6.01%) and with clinicaly advanced CRC. Patients treated because of perforation had a five-fold higher 30 day mortality rate (9.09% vs. 1.83%), however long-term survival did not differ significantly in both groups. After resectional surgery in 874 patients an intestinal anastomosis was made. Anastomotic leakage was present in 23 (2.6%) patients. This complication occurred six-fold more frequently in a group of patients operated upon because of intestinal perforation (12.20% vs. 2.16%). In patients with CRC complicated with perforation of the colon in a 30-day observation significantly higher rate of complications and mortality was shown, whereas there was no difference in distant survival rates.

  9. Design and fabrication of a self-aligned parallel-plate-type silicon micromirror minimizing the effect of misalignment

    International Nuclear Information System (INIS)

    Yoo, Byung-Wook; Jin, Joo-Young; Jang, Yun-Ho; Kim, Yong-Kweon; Park, Jae-Hyoung

    2009-01-01

    This paper describes a self-alignment method whereby a mirror actuation voltage, corresponding to a specific tilting angle, is unvarying in terms of misalignment during fabrication. A deep silicon etching process is proposed to penetrate the top silicon layer (the micromirror layer) and an amorphous silicon layer (the addressing electrode layer) together, through an aluminum mask pattern, in order to minimize the misalignment effect on the micromirror actuation. The size of a fabricated mirror plate is 250 × 250 × 4 µm 3 . A pair of amorphous silicon electrodes under the mirror plate is about half the size of the mirror plate individually. Numerical analysis associated with calculating the pull-in voltage and the bonding misalignment is performed to verify the self-alignment concepts focused upon in this paper. Curves of the applied voltage versus the tilt angle of the self-aligned micromirror are observed using a position sensing detector in order to compare the measurement results with MATLAB analysis of the expected static deflections. Although a 3.7 µm misalignment is found between the mirror plate and the electrodes, in the direction perpendicular to the shallow trench of the electrodes, before the self-alignment process, the measured pull-in voltage has been found to be 103.4 V on average; this differs from the pull-in voltage of a perfectly aligned micromirror by only 0.67%. Regardless of the unpredictable misalignments in repetitive photolithography and bonding, the tilting angles corresponding to the driving voltages are proved to be uniform along the single axis as well as conform to the results of analytical analysis

  10. Acoustic Liner Drag: Measurements on Novel Facesheet Perforate Geometries

    Science.gov (United States)

    Howerton, Brian M.; Jones, Michael G.

    2016-01-01

    Interest in characterization of the aerodynamic drag of acoustic liners has increased in the past several years. This paper details experiments in the NASA Langley Grazing Flow Impedance Tube to quantify the relative drag of several perforate-over-honeycomb liner configurations at flow speeds of centerline flow Mach number equals 0.3 and 0.5. Various perforate geometries and orientations are investigated to determine their resistance factors using a static pressure drop approach. Comparison of these resistance factors gives a relative measurement of liner drag. For these same flow conditions, acoustic measurements are performed with tonal excitation from 400 to 3000 hertz at source sound pressure levels of 140 and 150 decibels. Educed impedance and attenuation spectra are used to determine the impact of variations in perforate geometry on acoustic performance.

  11. Congenital Infantile Fibrosarcoma Causing Intestinal Perforation in a Newborn

    Directory of Open Access Journals (Sweden)

    Margarita Kaiser

    2017-01-01

    Full Text Available Congenital infantile fibrosarcoma (CIF is a rare malignant mesenchymal tumor and only 14 cases have been reported with gastrointestinal manifestation. We report about a female newborn delivered per emergency cesarean section at 34 weeks of gestation. Postnatally, she rapidly developed an acute abdomen and sonographic evidence of intestinal perforation requiring laparotomy on the first day of life. A perforated 2 × 3 cm sized spherical tumorous structure of the jejunum was identified. Due to unknown histopathology at this point and unclear resectional margins, she received a temporary ileostomy, which was closed two months later. Histopathology revealed a congenital intestinal fibrosarcoma without the characteristic ETV6-NTRK3 fusion transcript. In conclusion, this rare tumor must be considered as differential diagnosis of intestinal perforations in newborns.

  12. Percutaneous Emergency Needle Caecostomy for Prevention of Caecal Perforation.

    Science.gov (United States)

    Limmer, Alexandra M; Clement, Zackariah

    2017-01-01

    Caecal perforation is a life-threatening complication of large bowel obstruction with a reported mortality of 34% to 72%. This case describes the novel use of percutaneous needle caecostomy as a life-saving measure to prevent imminent caecal perforation in a 68-year-old lady with large bowel obstruction secondary to an incarcerated incisional hernia. After careful review of computed tomography images and measurement of distances from the abdominal wall to the caecum, the patient's caecum was decompressed in the emergency department using a needle under local anaesthetic. The patient subsequently underwent laparoscopic hernia repair and had an uncomplicated recovery. When conducted safely and with precision in an appropriate patient, percutaneous needle caecostomy can provide immediate symptom relief, reduce risk of caecal perforation, and allow a laparoscopic surgical approach.

  13. Percutaneous Emergency Needle Caecostomy for Prevention of Caecal Perforation

    Directory of Open Access Journals (Sweden)

    Alexandra M. Limmer

    2017-01-01

    Full Text Available Caecal perforation is a life-threatening complication of large bowel obstruction with a reported mortality of 34% to 72%. This case describes the novel use of percutaneous needle caecostomy as a life-saving measure to prevent imminent caecal perforation in a 68-year-old lady with large bowel obstruction secondary to an incarcerated incisional hernia. After careful review of computed tomography images and measurement of distances from the abdominal wall to the caecum, the patient’s caecum was decompressed in the emergency department using a needle under local anaesthetic. The patient subsequently underwent laparoscopic hernia repair and had an uncomplicated recovery. When conducted safely and with precision in an appropriate patient, percutaneous needle caecostomy can provide immediate symptom relief, reduce risk of caecal perforation, and allow a laparoscopic surgical approach.

  14. Titanium plate supported MoS{sub 2} nanosheet arrays for supercapacitor application

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lina; Ma, Ying [State Key Laboratory for Oxo Synthesis & Selective Oxidation, and National Engineering Research Center for Fine Petrochemical Intermediates, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Yang, Min [State Key Laboratory for Oxo Synthesis & Selective Oxidation, and National Engineering Research Center for Fine Petrochemical Intermediates, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Qi, Yanxing, E-mail: qiyx@lzb.ac.cn [State Key Laboratory for Oxo Synthesis & Selective Oxidation, and National Engineering Research Center for Fine Petrochemical Intermediates, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

    2017-02-28

    A promising new concept is to apply binder-free supercapacitor electrode by directly growing active materials on current collectors. However, there are many challenges to be solved, such as fabrication of well quality electronic contact and good mechanical stability films through a simple and feasible method. In this study, MoS{sub 2} nanosheet arrays supported on titanium plate has been synthesized by a hydrothermal method without other additives, surface active agents and toxic reagents. As the supercapacitor electrode, a good capacitance of 133 F g{sup −1} is attained at a discharge current density of 1 A g{sup −1}. The specific energy density is 11.11 Wh kg{sup −1} at a power density of 0.53 kW kg{sup −1}. Moreover, the electrode shows an excellent cyclic stability. The loss of capacity is only 7% even after 1000 cycles. In addition, the formation mechanism is proposed. The facile method of fabricating MoS{sub 2} nanosheet arrays on titanium plate affords an green and effective way to prepare other metal sulfides for the application in electrochemical capacitors.

  15. Perforated duodenal ulcer -a rare cause of acute abdomen in pregnancy.

    Science.gov (United States)

    Goel, Bharti; Rani, Jyotsna; Huria, Anju; Gupta, Pratiksha; Dalal, Usha

    2014-09-01

    Acute abdomen during pregnancy is a medico-surgical emergency demanding concerted, synchronized specialties approach of obstetrician, surgeon and gastroenterologist. Duodenal perforation is one of the rarer causes of acute abdomen in pregnancy. Here, we report a case of duodenal perforation with peritonitis in third trimester of pregnancy requiring surgical management. Our aim of reporting this case is to stress the physicians to keep the differential of duodenal perforation also in mind while dealing with cases of acute abdomen in pregnancy and to proceed with multidisciplinary approach for better feto-maternal outcome.

  16. Method for improving the electrostatics perforation pattern using power controlled discharges

    Energy Technology Data Exchange (ETDEWEB)

    Garzon, C; Miranda, E; GarcIa-Garcia, J [Departament d' Enginyeria Electronica, Universitat Autonoma de Barcelona, 08193 Bellaterra, Barcelona (Spain); Martinez-Cisneros, C; Alonso, J, E-mail: carolina.garzon@uab.cat [Departament de Quimica Analitica, Universitat Autonoma de Barcelona, 08193 Bellaterra, Barcelona (Spain)

    2011-06-23

    The aims of this work are to show the influence of adding a series resistance at the output of a discharge generator circuit and to point out that this component can be used to control the spark energy in electrostatic perforation systems. Analysis of the experimental results reveals that there exists a close connection between the resistor value and the obtained perforation pattern both in hole density and size. The use of a series resistor has a strong influence on the material porosity, which is an important industrial parameter for assessing the pattern perforation quality.

  17. Abdominal wall perforation in a patient with recurrent epithelial ovarian cancer after bevacizumab treatment

    Directory of Open Access Journals (Sweden)

    Efnan Algin

    2016-08-01

    Full Text Available Bowel perforation is a rare but well-described complication of bevacizumab, a VEGF monoclonal antibody. However, bevacizumab associated abdominal wall perforation is a more serious complication. In here, a patient with recurrent epithelial ovarian cancer developing both bowel and abdominal wall perforation after bevacizumab treatment is reported with review of the literature to point out the clinical significance of this rare complication. To our knowledge, this is the first case with bevacizumab associated abdominal wall perforation.

  18. Spontaneous neonatal gastrointestinal perforation: surgical or ...

    African Journals Online (AJOL)

    ... cases of spontaneous gastrointestinal perforation in neonates at the University of Benin Teaching Hospital, Benin City. The perinatal stress factors were caesarian delivery, prematurity and fetal distress due to prolonged obstructed labour.

  19. Bowel perforation in type IV vascular Ehlers-Danlos syndrome. A systematic review.

    Science.gov (United States)

    El Masri, H; Loong, T-H; Meurette, G; Podevin, J; Zinzindohoue, F; Lehur, P-A

    2018-05-01

    Spontaneous gastrointestinal (GI) perforation is a well-known complication occurring in patients suffering from Type IV vascular Ehlers-Danlos syndrome (EDS IV). The aim of the present study was to review the current literature on spontaneous GI perforation in EDS IV and illustrate the surgical management and outcome when possible. A systematic review of all the published data on EDS IV patients with spontaneous GI perforation between January 2000 and December 2015 was conducted using three major databases PUBMED, EMBASE, and Cochrane Central Register of Controlled Trails. References of the selected articles were screened to avoid missing main articles. Twenty-seven published case reports and four retrospective studies, including 31 and 527 cases, respectively, matched the search criteria. A case from our institution was added. Mean age was 26 years (range 6-64 years). The most frequent site of perforation was the colon, particularly the sigmoid, followed by small bowel, upper rectum, and finally stomach. The majority of cases were initially managed with Hartmann's procedure. In recurrent perforations, total colectomy was performed. The reperforation rate was considerably higher in the "partial colectomy with anastomosis" group than in the Hartmann group. Colonic perforation is the most common spontaneous GI perforation in EDS IV patients. An unexpected fragility of the tissues should raise the possibility of a connective tissue disorder and prompt further investigation with eventual management of these high-risk patients with a multidisciplinary team approach in dedicated centres. In the emergency setting, a Hartmann procedure should be performed.

  20. Anatomical study of the popliteal artery perforator-based propeller flap and its clinical application.

    Science.gov (United States)

    Onishi, Tadanobu; Shimizu, Takamasa; Omokawa, Shohei; Sananpanich, Kanit; Kido, Akira; Mahakkanukrauh, Pasuk; Tanaka, Yasuhito

    2018-05-30

    There is lack of anatomical information regarding cutaneous perforator of the popliteal artery and its connections with the descending branch of the inferior gluteal and profunda femoris arteries. We aimed to evaluate the anatomical basis of popliteal artery perforator-based propeller flap from the posterior thigh region and to demonstrate our experience utilizing this flap. Ten fresh cadaveric lower extremities were dissected following injection of a silicone compound into the femoral artery. We investigated the number, location, length, and diameter of cutaneous perforators of the popliteal artery. Based on the results, we treated three cases with a large soft tissue defect around the knee using popliteal artery perforator-based propeller flap. We found a mean of 1.9 cutaneous perforators arising from the popliteal artery with a mean pedicle length of 6 cm and a mean arterial internal diameter of 0.9 mm, which were located at an average of 4 cm proximal to the bicondylar line. The most distal perforator consistently arose along the small saphenous vein and connected proximally with concomitant artery of the posterior femoral cutaneous nerve, forming a connection with perforating arteries of the profunda femoris artery. A mean of 4.5 cutaneous perforators branched from the arterial connection sites. All clinical cases healed without any complications. The popliteal artery perforator-based propeller flap is reliable for reconstruction of soft tissue defects around the knee. The flap should include the deep fascia and concomitant artery along with the posterior femoral cutaneous nerve for maintaining the blood supply.

  1. Perfuração de Luvas durante Cirurgias Ginecológicas Glove Perforation during Gynecologic Surgeries

    Directory of Open Access Journals (Sweden)

    Eddie Fernando Candido Murta

    2000-05-01

    Full Text Available Objetivo: analisar a incidência de perfuração de luvas cirúrgicas durante atos operatórios ginecológicos. Métodos: estudo prospectivo de 454 luvas usadas em 65 procedimentos utilizando-se o método de pressão de água. Resultados: do total de 454 luvas examinadas, foram verificadas perfurações em 54 (11,9%, sendo estatisticamente significativo o maior número de perfurações em comparação ao grupo controle, uma (1,7% em 60 analisadas (pPurpose: to analyze the frequency of glove perforation during gynecologic surgeries. Methods: a prospective study of 454 gloves used in 65 surgeries by the water pressure method. Results: of a total of 454 gloves, 54 (11.9% had perforations. Comparison with the control group showed p<0.05 (chi² test, 1 (1.7% perforation in 60 gloves tested. Of the total of gloves used in 65 surgeries, 29 (44.6% had perforations, 44 (81% had one perforation and 10 (19% had more than one perforation. The two most common sites of perforations were the index finger, 20 (29.5% and the thumb, 14 (25.9%. Perforation was predominant in the left hand (72.1%. The surgeons were the members of the team with the greatest number of glove perforations. Total hysterectomy was the most frequent surgery in which glove perforations occurred (50% of the cases. Conclusion: the glove perforations occurred with relatively high frequency during gynecologic surgeries. The index finger of the left hand proved to be the most affected region. Among the members of the team, the highest percentage of glove perforations occurred in those of the surgeons. Total hysterectomy had the highest perforation rate.

  2. Right ventricular perforation by a passive-fixation pacemaker lead two weeks after implantation

    Directory of Open Access Journals (Sweden)

    Azeem S. Sheikh, BSc, MBBS, FCPS, MRCP

    2014-12-01

    Full Text Available Myocardial perforation is a rare complication of permanent pacemaker implantation. While most of the perforations occur at the time of implantation or within the first 24 h, delayed myocardial perforations are very rare. The clinical course is extremely variable with some patients presenting completely asymptomatic, while others can develop cardiac tamponade and haemodynamic instability. We report an unusual case of a subacute ventricular perforation caused by a passive-fixation lead two weeks after implantation and we successfully managed to extract the lead under local anaesthesia, without the patient undergoing surgery, as recommended in the previously published reports.

  3. Photothermal IR spectroscopy with perforated membrane micromechanical resonators

    DEFF Research Database (Denmark)

    Kurek, Maksymilian

    -IR method. In order to overcome them, string resonators were replaced by membranes. A reliable sampling technique was maintained by adding perforation to membranes and thereby essentially getting membrane porous filters. Membranes gave also access to fully integrated magnetic transduction that allowed...... for significant shrinkage and simplification of the system. An analytical model of a locally heated membrane was developed and confirmed through FEM simulations. Then, low stress silicon nitride perforated membranes were fabricated and characterized using two different experimental setups that employed optical...

  4. Perforating arteries originating from the posterior communicating artery: a 7.0-Tesla MRI study

    Energy Technology Data Exchange (ETDEWEB)

    Conijn, Mandy M.A.; Hendrikse, Jeroen; Takahara, Taro; Mali, Willem P.T.M. [University Medical Center Utrecht, Department of Radiology (Hp E 01.132), P.O. Box 85500, Utrecht (Netherlands); Zwanenburg, Jaco J.M. [University Medical Center Utrecht, Image Sciences Institute, Utrecht (Netherlands); Geerlings, Mirjam I. [University Medical Center Utrecht, Julius Center for Health Sciences and Primary Care, Utrecht (Netherlands); Luijten, Peter R. [University Medical Center Utrecht, Department of Radiology (Hp E 01.132), P.O. Box 85500, Utrecht (Netherlands); University Medical Center Utrecht, Image Sciences Institute, Utrecht (Netherlands)

    2009-12-15

    The aim of this study was to investigate the ability of time-of-flight (TOF) magnetic resonance (MR) angiography at 7.0 Tesla to show the perforating branches of the posterior communicating artery (PCoA), and to investigate the presence of such visible perforating branches in relation to the size of the feeding PCoA. The secondary aim was to visualise and describe the anterior choroidal artery and the perforating branches of the P1-segment of posterior cerebral artery (P1). Forty-six healthy volunteers underwent TOF MR angiography at 7.0 Tesla. With 7.0-Tesla imaging, we visualised for the first time perforating arteries originating from the PCoA in vivo without the use of contrast agents. A perforating artery from the PCoA was found in a large proportion of the PCoAs (64%). The presence was associated with a larger diameter of the underlying PCoA (1.23 versus 1.06 mm, P = 0.03). The anterior choroidal artery was visible bilaterally in all participants. In 83% of all P1s, one or two perforating branches were visible. Non-invasive assessment of the perforating arteries of the PCoA together with the anterior choroidal artery and the perforating arteries of the P1 may increase our understanding of infarcts in the deep brain structures supplied by these arteries. (orig.)

  5. Perforating arteries originating from the posterior communicating artery: a 7.0-Tesla MRI study

    International Nuclear Information System (INIS)

    Conijn, Mandy M.A.; Hendrikse, Jeroen; Takahara, Taro; Mali, Willem P.T.M.; Zwanenburg, Jaco J.M.; Geerlings, Mirjam I.; Luijten, Peter R.

    2009-01-01

    The aim of this study was to investigate the ability of time-of-flight (TOF) magnetic resonance (MR) angiography at 7.0 Tesla to show the perforating branches of the posterior communicating artery (PCoA), and to investigate the presence of such visible perforating branches in relation to the size of the feeding PCoA. The secondary aim was to visualise and describe the anterior choroidal artery and the perforating branches of the P1-segment of posterior cerebral artery (P1). Forty-six healthy volunteers underwent TOF MR angiography at 7.0 Tesla. With 7.0-Tesla imaging, we visualised for the first time perforating arteries originating from the PCoA in vivo without the use of contrast agents. A perforating artery from the PCoA was found in a large proportion of the PCoAs (64%). The presence was associated with a larger diameter of the underlying PCoA (1.23 versus 1.06 mm, P = 0.03). The anterior choroidal artery was visible bilaterally in all participants. In 83% of all P1s, one or two perforating branches were visible. Non-invasive assessment of the perforating arteries of the PCoA together with the anterior choroidal artery and the perforating arteries of the P1 may increase our understanding of infarcts in the deep brain structures supplied by these arteries. (orig.)

  6. Perforating arteries originating from the posterior communicating artery: a 7.0-Tesla MRI study.

    Science.gov (United States)

    Conijn, Mandy M A; Hendrikse, Jeroen; Zwanenburg, Jaco J M; Takahara, Taro; Geerlings, Mirjam I; Mali, Willem P Th M; Luijten, Peter R

    2009-12-01

    The aim of this study was to investigate the ability of time-of-flight (TOF) magnetic resonance (MR) angiography at 7.0 Tesla to show the perforating branches of the posterior communicating artery (PCoA), and to investigate the presence of such visible perforating branches in relation to the size of the feeding PCoA. The secondary aim was to visualise and describe the anterior choroidal artery and the perforating branches of the P1-segment of posterior cerebral artery (P1). Forty-six healthy volunteers underwent TOF MR angiography at 7.0 Tesla. With 7.0-Tesla imaging, we visualised for the first time perforating arteries originating from the PCoA in vivo without the use of contrast agents. A perforating artery from the PCoA was found in a large proportion of the PCoAs (64%). The presence was associated with a larger diameter of the underlying PCoA (1.23 versus 1.06 mm, P = 0.03). The anterior choroidal artery was visible bilaterally in all participants. In 83% of all P1s, one or two perforating branches were visible. Non-invasive assessment of the perforating arteries of the PCoA together with the anterior choroidal artery and the perforating arteries of the P1 may increase our understanding of infarcts in the deep brain structures supplied by these arteries.

  7. Fatal Gastrointestinal Perforations in sudden death cases in Last 10 ...

    African Journals Online (AJOL)

    Pathology unit of University Malaya, Kuala Lumpur in the year 2006 by reviewing the autopsy reports. There were 61 cases of GIT perforation out of 5579 autopsies conducted during a period of ten years (1996-2005). The incidence rate of fatal gastrointestinal perforation was 1.09% during this period. Out of these 61 cases, ...

  8. Management of a Small Paracentral Corneal Perforation Using Iatrogenic Iris Incarceration and Tissue Adhesive

    Directory of Open Access Journals (Sweden)

    Akira Kobayashi

    2012-07-01

    Full Text Available Background: Surgical intervention for corneal perforation is indicated when the anterior chamber does not reform within a short period of time. Herein, we report the successful management of a small paracentral corneal perforation using autologous iris incarceration and tissue adhesive. Case: A 41-year-old man developed a small paracentral corneal perforation (0.5 mm in size in the right eye, while the treating physician attempted to remove the residual rust ring after removal of a piece of metallic foreign body. Observations: The eye was initially managed with a bandage soft contact lens to ameliorate the aqueous leakage; however, without success. Iatrogenic iris incarceration of the wound was first induced, followed by application of cyanoacrylate tissue adhesive to the perforated site. As a result, the anterior chamber was immediately reformed and maintained. Complete corneal epithelialization of the perforation was achieved in 2 months without visual compromises. Conclusions: Cyanoacrylate tissue adhesive with iatrogenic incarceration of the autologous iris was effective in treating this type of small corneal perforation. This technique is simple and potentially useful for small paracentral corneal perforations outside the visual axis and without good apposition.

  9. Asymptotical construction of a fully coupled, Reissner–Mindlin model for piezoelectric composite plates

    International Nuclear Information System (INIS)

    Liao Lin; Yu Wenbin

    2008-01-01

    The variational asymptotic method is used to construct a fully coupled Reissner–Mindlin model for piezoelectric composite plates with some surfaces parallel to the reference surface coated with electrodes. Taking advantage of the smallness of the plate thickness, we asymptotically split the original three-dimensional electromechanical problem into a one-dimensional through-the-thickness analysis and a two-dimensional plate analysis. The through-the-thickness analysis serves as a link between the original three-dimensional analysis and the plate analysis by providing a constitutive model for the plate analysis and recovering the three-dimensional field variables in terms of two-dimensional plate global responses. The present theory is implemented into the computer program VAPAS (variational asymptotic plate and shell analysis). The resulting model is as simple as an equivalent single-layer, first-order shear deformation theory with accuracy comparable to higher-order layerwise theories. Various numerical examples have been used to validate the present model

  10. Numerical Simulation of Stationary AC Tungsten Inert Gas Welding of Aluminum Plate in Consideration of Oxide Layer Cleaning

    Science.gov (United States)

    Tashiro, Shinichi; Tanaka, Manabu

    An unified numerical simulation model of AC TIG welding of the aluminum plate considering energy balance among the electrode, the arc and the base metal and employing an analytical model for calculating cleaning rate of the oxide layer has been developed for investigating heat transport properties and weld pool formation process in AC TIG welding of aluminum plate. As a result of this simulation, it was shown that although the heat flux from the arc onto the base metal increases in EN (Electrode Negative) phase due to the electron condensation, that in EP (Electrode Positive) phase conversely decreases because mainly of cooling caused by the electron emission. Furthermore, the validity of the simulation model was confirmed by comparing to experimental results such as the arc voltage, the area of cleaning zone and the shape of weld pool.

  11. ENVIRONMENTAL MONITORING OF LEAKS USING TIME LAPSED LONG ELECTRODE ELECTRICAL RESISTIVITY

    International Nuclear Information System (INIS)

    Myers, D.A.; Rucker, D.F.; Fink, J.B.; Loke, M.H.

    2009-01-01

    Highly industrialized areas pose challenges for surface electrical resistivity characterization due to metallic infrastructure. The infrastructure is typically more conductive than the desired targets and will mask the deeper subsurface information. These challenges may be minimized if steel-cased wells are used as long electrodes in the area near the target. We demonstrate a method of using long electrodes to electrically monitor a simulated leak from an underground storage tank with both synthetic examples and a field demonstration. The synthetic examples place a simple target of varying electrical properties beneath a very low resistivity layer. The layer is meant to replicate the effects of infrastructure. Both surface and long electrodes are tested on the synthetic domain. The leak demonstration for the field experiment is simulated by injecting a high conductivity fluid in a perforated well within the S tank farm at Hanford, and the resistivity measurements are made before and after the leak test. All data are processed in four dimensions, where a regularization procedure is applied in both the time and space domains. The synthetic test case shows that the long electrode ERM could detect relative changes in resistivity that are commensurate with the differing target properties. The surface electrodes, on the other hand, had a more difficult time matching the original target's footprint. The field results shows a lowered resistivity feature develop south of the injection site after cessation of the injections. The time lapsed regularization parameter has a strong influence on the differences in inverted resistivity between the pre and post injection datasets, but the interpretation of the target is consistent across all values of the parameter. The long electrode ERM method may provide a tool for near real-time monitoring of leaking underground storage tanks.

  12. [Operative laparoscopy in the management of perforated peptic ulcer].

    Science.gov (United States)

    Schirru, Angelo; Cavaliere, Davide; Caristo, Ilario; Bianchi, Massimo; Cosce, Umberto; Mariani, Federica; Scarimbolo, Monica; Cavaliere, Paolo

    2004-01-01

    The aim of this retrospective study was to assess the feasibility, safety and efficacy of the laparoscopic approach in the management of perforated peptic ulcers. From January 1997 to December 2002, all patients referred to our community hospital for abdominal surgical emergencies were routinely managed by laparoscopic surgery. A review was carried out on 39 consecutive patients suffering from perforated peptic ulcers with or without generalised peritonitis. The study population comprised 24 male and 15 female patients, aged 30 to 94 years (mean age: 62 +/- 18). Laparoscopic repair was attempted in all patients. Laparoscopy afforded the correct diagnosis in all cases. Laparoscopic peritoneal washout (irrigation and suction of the entire abdominal cavity) with simple suture of the perforation proved successful in 34 patients. An additional omental patching was performed in 15 of these cases. Conversion to conventional open surgery was necessary in 5 patients. The morbidity and mortality rates were 13% and 10%, respectively. The mean operative time was 77 minutes (range: 40-120) and the mean hospital stay 9 days (range: 3-22). Laparoscopic repair of perforated ulcers is technically feasible but requires sound experience in laparoscopic abdominal emergencies. This study shows that the mini-invasive procedure is safe and effective, offering a valid alternative to traditional laparotomy.

  13. Primary Report of Totally Tubeless Percutaneous Nephrolithotomy Despite Pelvi-calyceal Perforations.

    Science.gov (United States)

    Aghamir, Seyed Mohammad Kazem; Salavati, Alborz; Hamidi, Morteza; FallahNejad, Asghar

    2017-07-02

    Nephrostomy tube insertion and/or a ureteral stent placement is advised when pelvi-calyceal perforations are encountered during percutaneous nephrolithotomy (PNL) nevertheless totally tubeless PNL is a possible exit strategy in percutaneous renal surgery therefore case series on the short term clinical outcomes of noninvasive management of iatrogenic pelvicalyceal perforations encountered during PNL is presented. During retrospective analysis of 1271 PNL procedures, 25 incidents of accidental ureteral catheter/ jj stent dislodgement during first 24 post-operative hours were identified in patient who had pelvi calyceal perforations and had no nephrostomy tube (tubeless). Thirteen patients could not be re-stented nor a nephrostomytube could have been placed for them mainly due to patient refusal or comorbid conditions. The main outcome was rate of successful noninvasive management. Eighteen Patients bearing mucosal tears (grade I trauma) or visible peri-pelvic fat (grade II) successfully recovered without need for ureteral stenting or nephrostomy (72.0%). In seven (28.0%) cases of extension of the perforation into the peri-pelvic fat (grade III), either nephrostomy insertion or JJ stenting was needed for resolution of fever and urinoma. The major limitation was the necessity to exclude patients and manage them in the standard fashion according to clinical guidelines. Iatrogenic perforations of the collecting system are quite diverse in terms of severity that result in different natural histories and not all might need urinary diversion via nephrostomy or ureteral stenting.Low grade perforations may be successfully managed in totally tubeless fashion nevertheless further prospective investigations seem warranted.

  14. Management of nontraumatic corneal perforation with tectonic drape patch and cyanoacrylate glue.

    Science.gov (United States)

    Khalifa, Yousuf M; Bailony, M Rami; Bloomer, Michele M; Killingsworth, Daniel; Jeng, Bennie H

    2010-10-01

    To report a case of nontraumatic corneal perforation managed with a tectonic drape patch. Interventional case report. A 60-year-old patient with a corneal scar in his left eye likely secondary to herpes simplex virus interstitial keratitis underwent laser peripheral iridotomy for narrow angles. He developed progressive thinning of the cornea overlying the scar that led to a descemetocele and then ultimately a 1.2- × 1.7-mm perforation. Intraoperatively, several attempts were made to seal the perforation with cyanoacrylate glue, but the wound continued to leak. Sterile plastic drape that was on the surgical field was fashioned into a 2-mm-diameter patch, and the peripheral edge of the tectonic drape patch was glued over the perforation, successfully sealing the cornea. One week later, the drape patch was intact without leak, and a penetrating keratoplasty was carried out without complication. Tectonic drape patch technique for nontraumatic corneal perforations in which there is tissue loss is a viable temporizing option when cyanoacrylate glue alone fails and when there is no corneal tissue or amniotic membrane available to close the wound.

  15. Perforation and bacterial contamination of microscope covers in lumbar spinal decompressive surgery.

    Science.gov (United States)

    Osterhoff, Georg; Spirig, José; Klasen, Jürgen; Kuster, Stefan P; Zinkernagel, Annelies S; Sax, Hugo; Min, Kan

    2014-01-01

    To determine the integrity of microscope covers and bacterial contamination at the end of lumbar spinal decompressive surgery. A prospective study of 25 consecutive lumbar spinal decompressions with the use of a surgical microscope was performed. For detection of perforations, the microscope covers were filled with water at the end of surgery and the presence of water leakage in 3 zones (objective, ocular and control panel) was examined. For detection of bacterial contamination, swabs were taken from the covers at the same locations before and after surgery. Among the 25 covers, 1 (4%) perforation was observed and no association between perforation and bacterial contamination was seen; 3 (4%) of 75 smears from the 25 covers showed post-operative bacterial contamination, i.e. 2 in the ocular zone and 1 in the optical zone, without a cover perforation. The incidence of microscope cover perforation was very low and was not shown to be associated with bacterial contamination. External sources of bacterial contamination seem to outweigh the problem of contamination due to failure of cover integrity. © 2014 S. Karger AG, Basel.

  16. Gastro-duodenal perforations: conventional plain film, US and CT findings in 166 consecutive patients

    International Nuclear Information System (INIS)

    Grassi, Roberto; Romano, Stefania; Pinto, Antonio; Romano, Luigia

    2004-01-01

    Introduction: Gastro-duodenal perforations may be suspected in patients with history of ulceration, who present with acute pain and abdominal wall rigidity, but radiological findings in these cases may be unable to confirm a clinical diagnosis. The aim of our study was to report our experience in the diagnosis of gastro-duodenal perforation by conventional radiography, US and CT examinations. Material and methods: We retrospectively reviewed medical records of 166 consecutive patients who presented in the last 2 years to our institutions with symptoms of acute abdomen and submitted to surgery at the Emergency Unit of the ''A.Cardarelli'' Hospital of Naples with a surgical finding of perforated gastro-duodenal ulcer. The evidence of free intraperitoneal air on abdominal plain film was considered as a direct or suggestive finding of perforation. Evidence of intraperitoneal free fluid and/or reduced intestinal peristalsis at sonographic examination were considered indirect signs of gastro-duodenal perforation. Evidence of free peritoneal gas at CT was considered as a direct evidence of gastro-duodenal perforation. Results: Twenty patients underwent immediate surgery with no preoperative imaging evaluation, in 10 of them the site of perforation was found in a juxta-pyloric region and in the others at level of duodenum. In 146 patients submitted to serial radiological investigations before surgery, the site of perforation was in 56 (38.3%) duodenal, in 52 (35.6%) juxta-pyloric, in 28 (19.1%) gastric and in 10 (6.8%) pyloric. The cause of perforation was in all cases gastric or duodenal ulceration, in seven cases involving pancreatic parenchyma. In 110 (75.4%) patients with direct findings of perforation, in 94 cases (85.5%) the correct diagnosis was established on abdominal plain film, in two (1.8%) with radiographic and sonographic examinations and in 14 (12.7%) on CT findings. In 36 (24,6%) patients with no direct findings of perforation, only 24 (16,4%) of them

  17. Gastro-duodenal perforations: conventional plain film, US and CT findings in 166 consecutive patients

    Energy Technology Data Exchange (ETDEWEB)

    Grassi, Roberto; Romano, Stefania E-mail: stefromano@libero.it; Pinto, Antonio; Romano, Luigia

    2004-04-01

    Introduction: Gastro-duodenal perforations may be suspected in patients with history of ulceration, who present with acute pain and abdominal wall rigidity, but radiological findings in these cases may be unable to confirm a clinical diagnosis. The aim of our study was to report our experience in the diagnosis of gastro-duodenal perforation by conventional radiography, US and CT examinations. Material and methods: We retrospectively reviewed medical records of 166 consecutive patients who presented in the last 2 years to our institutions with symptoms of acute abdomen and submitted to surgery at the Emergency Unit of the ''A.Cardarelli'' Hospital of Naples with a surgical finding of perforated gastro-duodenal ulcer. The evidence of free intraperitoneal air on abdominal plain film was considered as a direct or suggestive finding of perforation. Evidence of intraperitoneal free fluid and/or reduced intestinal peristalsis at sonographic examination were considered indirect signs of gastro-duodenal perforation. Evidence of free peritoneal gas at CT was considered as a direct evidence of gastro-duodenal perforation. Results: Twenty patients underwent immediate surgery with no preoperative imaging evaluation, in 10 of them the site of perforation was found in a juxta-pyloric region and in the others at level of duodenum. In 146 patients submitted to serial radiological investigations before surgery, the site of perforation was in 56 (38.3%) duodenal, in 52 (35.6%) juxta-pyloric, in 28 (19.1%) gastric and in 10 (6.8%) pyloric. The cause of perforation was in all cases gastric or duodenal ulceration, in seven cases involving pancreatic parenchyma. In 110 (75.4%) patients with direct findings of perforation, in 94 cases (85.5%) the correct diagnosis was established on abdominal plain film, in two (1.8%) with radiographic and sonographic examinations and in 14 (12.7%) on CT findings. In 36 (24,6%) patients with no direct findings of perforation, only 24

  18. Hollow organ perforation in blunt abdominal trauma: the role of diagnostic peritoneal lavage.

    Science.gov (United States)

    Wang, Yu-Chun; Hsieh, Chi-Hsun; Fu, Chih-Yuan; Yeh, Chun-Chieh; Wu, Shih-Chi; Chen, Ray-Jade

    2012-05-01

    With recent advances in radiologic diagnostic procedures, the use of diagnostic peritoneal lavage (DPL) has markedly declined. In this study, we reviewed data to reevaluate the role of DPL in the diagnosis of hollow organ perforation in patients with blunt abdominal trauma. Adult patients who had sustained blunt abdominal trauma and who were hemodynamically stable after initial resuscitation underwent an abdominal computed tomographic (CT) scan. Diagnostic peritoneal lavage was performed for patients who were indicated to receive nonoperative management and where hollow organ perforation could not be ruled out. During a 60-month period, 64 patients who had received abdominal CT scanning underwent DPL. Nineteen patients were diagnosed as having a positive DPL based on cell count ratio of 1 or higher. There were 4 patients who sustained small bowel perforation. The sensitivity and specificity of the cell count ratio for a hollow organ perforation in this study were 100% and 75%, respectively. No missed hollow organ perforations were detected. For patients with blunt abdominal trauma and hemoperitoneum who plan to receive nonoperative management, DPL is still a useful tool to exclude hollow organ perforation that is undetected by CT. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. Combined esophageal injury complicated by progression to a second perforation: a case report

    Directory of Open Access Journals (Sweden)

    Krieg Andreas

    2009-09-01

    Full Text Available Abstract Introduction Intramural dissection of the esophagus is a rare disorder characterized by a lesion between the submucosa and mucosa dividing the esophagus into a false and true lumen. The etiology of esophageal dissection remains uncertain but it affects predominantly women in their seventies and eighties. Symptoms may include uncharacteristic ones such as retrosternal pain, odynophagia or dysphagia. Conservative management is thought to be adequate and surgery should only be performed if complications such as abscess formation or perforation appear. Here we report the case and surgical management of a combined esophageal perforation and dissection. Case presentation We report the case of a combined esophageal perforation and dissection in a 45-year-old Caucasian woman with a history of relapsing periods of dysphagia since her childhood. The clinical course in this patient was complicated by progression to a second perforation, which made a definitive surgical management by esophagectomy necessary. Conclusion To the best of our knowledge, this is the first reported case of a combined esophageal perforation and dissection complicated by progression to a second perforation. This emphasizes that cautious and intensive observation is necessary in patients with esophageal dissection.

  20. Oral antibiotics for perforated appendicitis is not recommended

    DEFF Research Database (Denmark)

    Alamili, Mahdi; Gögenur, Ismail; Rosenberg, Jacob

    2010-01-01

    In the majority of surgical departments in Denmark, the postoperative treatment for acute perforated appendicitis comprises three days of intravenous antibiotics. Recently, it has been proposed that such antibiotic regimen should be replaced by orally administered antibiotics. The aim of this paper...... was to give an overview of studies on acute perforated appendicitis with postoperative oral antibiotics. Five studies were found in a database search covering the 1966-2009 period. There is no evidence to support a conversion of the postoperative antibiotic regimen from intravenous to oral administration...

  1. Perforated Peptic Ulcer: new insights

    NARCIS (Netherlands)

    M.J.O.E. Bertleff (Marietta)

    2011-01-01

    textabstractMuch has been written on perforated peptic ulcer (PPU) during the last hundred years. In 1500, when necropsies were first allowed, often a small hole was found in the anterior wall of the stomach, giving an explanation for symptoms of acute abdominal pain, nausea, vomiting which often

  2. Repair of an Endoscopic Retrograde Cholangiopancreatography-Related Large Duodenal Perforation Using Double Endoscopic Band Ligation and Endoclipping

    Directory of Open Access Journals (Sweden)

    Keunmo Kim

    2017-03-01

    Full Text Available Endoscopic closure techniques have been introduced for the repair of duodenal wall perforations that occur during endoscopic retrograde cholangiopancreatography (ERCP. We report a case of successful repair of a large duodenal wall perforation by using double endoscopic band ligation (EBL and an endoclip. Lateral duodenal wall perforation occurred during ERCP in a 93-year-old woman with acute calculous cholangitis. We switched to a forward endoscope that had a transparent band apparatus. A 2.0-cm oval-shaped perforation was found at the lateral duodenal wall. We repaired the perforation by sequentially performing double EBL and endoclipping. The first EBL was performed at the proximal edge of the perforation orifice, and two-thirds of the perforation were repaired. The second EBL, which also included the contents covered under the first EBL, repaired the defect almost completely. Finally, to account for the possible presence of a residual perforation, an endoclip was applied at the distal end of the perforation. The detection and closure of the perforation were completed within 10 minutes. We suggest that double EBL is an effective method for closure.

  3. Comparative research of finite element methods for perforated structures of nuclear power plant primary equipment

    International Nuclear Information System (INIS)

    Xiong Guangming; Deng Xiaoyun; Jin Ting

    2013-01-01

    Many perforated structures are used for nuclear power plant primary equipment, and they are complex, and have various forms. In order to explore the analysis and evaluation method, this paper used finite element method and equivalent analytic method to do the comparative analysis of perforated structures. The paper considered the main influence factors (including perforated forms, arrangements, and etc.), obtaining the systematic analysis methods of perforated structures. (authors)

  4. Vinorelbine induced perforation of a metastatic gastric lesion.

    Science.gov (United States)

    Mullally, W J; O'Súilleabháin, C B; Brady, C; O'Reilly, S

    2017-08-01

    Breast carcinoma metastasis to the gastrointestinal tract is rare and more frequently associated with lobular than ductal carcinoma (Borst and Ingold, Surg 114(4):637-641 [1]). The purpose of this article is to present a case based review of a unique gastrointestinal metastasis and literature review. A 46 year old lady with metastatic invasive ductal breast cancer was admitted to A&E with sudden onset of epigastric and left shoulder pain. She completed the first cycle of capecitabine/vinorelbine 1 week previously. Clinical examination revealed a tender epigastrium with rigidity in the upper abdomen. Free air under the diaphragm and a positive Rigler's sign was radiologically identified. A laparoscopy demonstrated a fibrinous exudate in the left upper quadrant consistent with a walled off lesser curvature gastric perforation. A subsequent oesophagogastroduodenoscopy (OGD) demonstrated a healed gastric ulcer of benign appearance; however the pathology confirmed metastatic breast carcinoma. Literature review confirmed no previously reported cases of vinorelbine induced gastric perforation. Four cases of metastatic breast cancer with gastric metastasis presenting with perforation were identified; three of these cases (Fra et al., Presse Med 25(26):1215 (1996) [2], Solis-Caxaj et al., Gastroenterol Clin Biol 28(1):91-92 (2004) [3], Ghosn et al., Bull Cancer 78(11):1071-1073 (1991) [4]), were in the French medical literature, including one male patient (Fra et al., Presse Med 25(26):1215 (1996) [2]) and at least one ductal breast carcinoma (Solis-Caxaj et al., Gastroenterol Clin Biol 28(1):91-92 (2004) [3]). The fourth case (van Geel et al., Ned Tijdschr Geneeskd 144(37):1761-1763 (2000) [5]), was in the Dutch medical literature and a lobular breast carcinoma. This case represents a rare complication of breast cancer chemotherapy, the subsequent significant benefit the patient received from treatment is consistent with the chemosensitivity to therapy that also resulted

  5. Mesenchymal stem cell-laden hybrid scaffold for regenerating subacute tympanic membrane perforation

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Chul Ho, E-mail: chulsavio@hanmail.net [Department of Otolaryngology, Chonnam National University Medical School, Gwangju (Korea, Republic of); Ahn, SeungHyun [Department of Biomechatronic Engineering, College of Biotechnology and Bioengineering, Sungkyunkwan University, Suwon (Korea, Republic of); Lee, Jae Whi; Lee, Byeong Ha [School of Information and Communications, Gwangju Institute of Science and Technology, Gwangju (Korea, Republic of); Lee, Hyeongjin [Department of Biomechatronic Engineering, College of Biotechnology and Bioengineering, Sungkyunkwan University, Suwon (Korea, Republic of); Kim, GeunHyung, E-mail: gkimbme@skku.edu [Department of Biomechatronic Engineering, College of Biotechnology and Bioengineering, Sungkyunkwan University, Suwon (Korea, Republic of)

    2017-03-01

    Tympanic membrane (TM) perforation is one of the most common otology complications. To date, there has not been reported TM regeneration using bioprinted scaffold. The purpose of this study was to evaluate the efficacy and feasibility of bioprinted polycaprolactone/collagen/alginate-mesenchymal stem cell (PCAMSC) scaffolds for the regeneration of subacute TM perforation. Sprague-Dawley rats were used in an animal model of subacute TM perforation. In the experimental group (n = 7), bioprinted 3D PCAMSC scaffold was placed on the perforation. The control group (n = 7) were treated with polycaprolactone/collagen/alginate (PCA) scaffold. Healing time, acoustic-mechanical properties, and morphological analysis were performed by otoendoscopy, auditory brainstem response (ABR), single-point laser doppler vibrometer (LDV), optical coherence tomography (OCT), and light microscopic evaluation. The closure of the TM perforation was achieved in 100% of the experimental group vs. 72% of the control group, and this difference was statistically significant (p < 0.05). The ABR threshold at all frequencies of the experimental group was recovered to the normal level compared to the control group. TM vibration velocity in the experimental group recovered similar to the normal control level. The difference are very small and they are not statistically significant below 1 kHz (p = 0.074). By OCT and light microscopic examination, regenerated TM of the experimental group showed thickened fibrous and mucosal layer. In contrast, the control group showed well regenerated but less thickened than experimental group. From these results, the cell-laden PCAMSC scaffold offers a significant advantage in the TM regeneration in a rat subacute TM perforation model. It may offer attractive opportunities in the conservative clinical treatment. - Highlights: • MSCs-laden scaffold was fabricated using a centrifugal spinning and cell-printing process. • The cell-laden scaffold showed the outstanding

  6. Mesenchymal stem cell-laden hybrid scaffold for regenerating subacute tympanic membrane perforation

    International Nuclear Information System (INIS)

    Jang, Chul Ho; Ahn, SeungHyun; Lee, Jae Whi; Lee, Byeong Ha; Lee, Hyeongjin; Kim, GeunHyung

    2017-01-01

    Tympanic membrane (TM) perforation is one of the most common otology complications. To date, there has not been reported TM regeneration using bioprinted scaffold. The purpose of this study was to evaluate the efficacy and feasibility of bioprinted polycaprolactone/collagen/alginate-mesenchymal stem cell (PCAMSC) scaffolds for the regeneration of subacute TM perforation. Sprague-Dawley rats were used in an animal model of subacute TM perforation. In the experimental group (n = 7), bioprinted 3D PCAMSC scaffold was placed on the perforation. The control group (n = 7) were treated with polycaprolactone/collagen/alginate (PCA) scaffold. Healing time, acoustic-mechanical properties, and morphological analysis were performed by otoendoscopy, auditory brainstem response (ABR), single-point laser doppler vibrometer (LDV), optical coherence tomography (OCT), and light microscopic evaluation. The closure of the TM perforation was achieved in 100% of the experimental group vs. 72% of the control group, and this difference was statistically significant (p < 0.05). The ABR threshold at all frequencies of the experimental group was recovered to the normal level compared to the control group. TM vibration velocity in the experimental group recovered similar to the normal control level. The difference are very small and they are not statistically significant below 1 kHz (p = 0.074). By OCT and light microscopic examination, regenerated TM of the experimental group showed thickened fibrous and mucosal layer. In contrast, the control group showed well regenerated but less thickened than experimental group. From these results, the cell-laden PCAMSC scaffold offers a significant advantage in the TM regeneration in a rat subacute TM perforation model. It may offer attractive opportunities in the conservative clinical treatment. - Highlights: • MSCs-laden scaffold was fabricated using a centrifugal spinning and cell-printing process. • The cell-laden scaffold showed the outstanding

  7. Surgical implications of perimodiolar cochlear implant electrode design: avoiding intracochlear damage and scala vestibuli insertion.

    Science.gov (United States)

    Briggs, R J; Tykocinski, M; Saunders, E; Hellier, W; Dahm, M; Pyman, B; Clark, G M

    2001-09-01

    To review the mechanisms and nature of intracochlear damage associated with cochlear implant electrode array insertion, in particular, the various perimodiolar electrode designs. Make recommendations regarding surgical techniques for the Nucleus Contour electrode to ensure correct position and minimal insertion trauma. The potential advantages of increased modiolar proximity of intracochlear multichannel electrode arrays are a reduction in stimulation thresholds, an increase in dynamic range and more localized neural excitation. This may improve speech perception and reduce power consumption. These advantages may be negated if increased intracochlear damage results from the method used to position the electrodes close to the modiolus. A review of the University of Melbourne Department of Otolaryngology experience with temporal bone safety studies using the Nucleus standard straight electrode array and a variety of perimodiolar electrode array designs; comparison with temporal bone insertion studies from other centres and postmortem histopathology studies reported in the literature. Review of our initial clinical experience using the Nucleus Contour electrode array. The nature of intracochlear damage resulting from electrode insertion trauma ranges from minor, localized, spiral ligament tear to diffuse organ of Corti disruption and osseous spiral lamina fracture. The type of damage depends on the mechanical characteristics of the electrode array, the stiffness, curvature and size of the electrode in relation to the scala, and the surgical technique. The narrow, flexible, straight arrays are the least traumatic. Pre-curved or stiffer arrays are associated with an incidence of basilar membrane perforation. The cochleostomy must be correctly sited in relation to the round window to ensure scala tympani insertion. A cochleostomy anterior to the round window rather than inferior may lead to scala media or scala vestibuli insertion. Proximity of electrodes to the modiolus

  8. Oxidation of ammonium sulfite by a multi-needle-to-plate gas phase pulsed corona discharge reactor

    Science.gov (United States)

    Ren, Hua; Lu, Na; Shang, Kefeng; Li, Jie; Wu, Yan

    2013-03-01

    The oxidation of ammonium sulfite in the ammonia-based flue gas desulfurization (FGD) process was investigated in a multi-needle-to-plate gas phase pulsed corona discharge reactor in this paper. The effect of several parameters, including capacitance and peak pulse voltage of discharge system, electrode gap and bubbling gas flow rate on the oxidation rate of ammonium sulfite was reviewed. The oxidation rate of ammonium sulfite could reach 47.2% at the capacitance, the peak pulse voltage, electrode gap and bubbling gas flow rate equal to 2 nF, -24.6 k V, 35 mm and 4 L min-1 within treatment time of 40 min The experimental results indicate that the gas phase pulsed discharge system with a multi-needle-to-plate electrode can oxide the ammonium sulfite. The oxidation rate increased with the applied capacitance and peak pulse voltage and decreased with the electrode gap. As the bubbling gas flow rate increased, the oxidation rate increased first and then tended to reach a stationary value. These results would be important for the process optimization of the (NH4)2SO3 to (NH4)2SO4 oxidation.

  9. Ultrasound and Perforated Viscus; Dirty Fluid, Dirty Shadows, and Peritoneal Enhancement

    Directory of Open Access Journals (Sweden)

    Hamid Shokoohi

    2016-04-01

    Full Text Available Early detection of free air in the peritoneal cavity is vital in diagnosis of life-threatening emergencies, and can play a significant role in expediting treatment. We present a series of cases in which bedside ultrasound (US in the emergency department accurately identified evidence of free intra-peritoneal air and echogenic (dirty free fluid consistent with a surgical final diagnosis of a perforated hollow viscus. In all patients with suspected perforated viscus, clinicians were able to accurately identify the signs of pneumoperitoneum including enhanced peritoneal stripe sign (EPSS, peritoneal stripe reverberations, and focal air collections associated with dirty shadowing or distal multiple reflections as ring down artifacts. In all cases, hollow viscus perforation was confirmed surgically. It seems that, performing US in patients with suspected perforated viscus can accurately identify presence of intra-peritoneal echogenic or “dirty” free fluid as well as evidence of free air, and may expedite patient management.

  10. Acute abdominal compartment syndrome complicating a colonoscopic perforation: a case report

    Directory of Open Access Journals (Sweden)

    Souadka Amine

    2012-02-01

    Full Text Available Abstract Introduction A perforation occurring during colonoscopy is an extremely rare complication that may be difficult to diagnose. It can be responsible for acute abdominal compartment syndrome, a potentially lethal complex pathological state in which an acute increase in intra-abdominal pressure may provoke the failure of several organ systems. Case presentation We report a case of acute abdominal compartment syndrome after perforation of the bowel during a colonoscopy in a 60-year-old North African man with rectal cancer, resulting in respiratory distress, cyanosis and cardiac arrest. Our patient was treated by needle decompression after the failure of cardiopulmonary resuscitation. An emergency laparotomy with anterior resection, including the perforated sigmoid colon, was then performed followed by immediate anastomosis. Our patient remains alive and free of disease three years later. Conclusion Acute abdominal compartment syndrome is a rare disease that may occasionally occur after a colonoscopic perforation. It should be kept in mind during colonoscopy, especially considering its simple salvage treatment.

  11. Displaced proximal humeral fractures: an Indian experience with locking plates

    Directory of Open Access Journals (Sweden)

    Aggarwal Sameer

    2010-08-01

    Full Text Available Abstract Background The treatment of displaced proximal humerus fractures, especially in elderly, remains controversial. The objective of this study was to evaluate functional outcome of locking plate used for fixation of these fractures after open reduction. We also attempted to evaluate the complications and predictors of loss of fixation for such an implant. Methods Over two and a half years, 56 patients with an acute proximal humerus fracture were managed with locking plate osteosynthesis. 47 of these patients who completed a minimum follow up of 1 year were evaluated using Constant score calculation. Statistical analysis was done using SPSS 16 and a p value of less than 0.05 was taken as statistically significant. Results The average follow up period was around 21.5 months. Outcomes were excellent in 17%, good in 38.5%, moderate in 34% while poor in 10.5%. The Constant score was poorer for AO-OTA type 3 fractures as compared to other types. The scores were also inferior for older patients (> 65 years old. Complications included screw perforation of head, AVN, subacromial impingement, loss of fixation, axillary nerve palsy and infection. A varus malalignment was found to be a strong predictor of loss of fixation. Conclusion Locking plate osteosynthesis leads to satisfactory functional outcomes in all the patients. Results are better than non locking plates in osteoporotic fractures of the elderly. However the surgery has steep learning curve and various complications could be associated with its use. Nevertheless we believe that a strict adherence to the principles of locking plate use can ensure good result in such challenging fractures.

  12. Environmental Monitoring Of Leaks Using Time Lapsed Long Electrode Electrical Resistivity

    International Nuclear Information System (INIS)

    Rucker, D.F.; Fink, J.B.; Loke, M.H.; Myers, D.A.

    2009-01-01

    Highly industrialized areas pose significant challenges for surface based electrical resistivity characterization and monitoring due to the high degree of metallic infrastructure. The infrastructure is typically several orders of magnitude more conductive than the desired targets, preventing the geophysicist from obtaining a clear picture of the subsurface. These challenges may be minimized if steel-cased wells are used as long electrodes. We demonstrate a method of using long electrodes in a complex nuclear waste facility to monitor a simulated leak from an underground storage tank. The leak was simulated by injecting high conductivity fluid in a perforated well and the resistivity measurements were made before and after the leak test. The data were processed in four dimensions, where a regularization procedure was applied in both the time and space domains. The results showed a lowered resistivity feature develop south of the injection site. The time lapsed regularization parameter had a strong influence on the differences in inverted resistivity between the pre and post datasets, potentially making calibration of the results to specific hydrogeologic parameters difficult.

  13. Improved productivity justifies world record underbalanced perforating operation

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, A. M.; Bakker, E. R. [NAM B.V. (Netherlands); Hungerford, K.

    1998-12-31

    To achieve vertical connectivity with all the layers, and thus long term sustained productivity in a highly stratified reservoir, a one run underbalanced perforating operation was considered necessary. Due to coiled tube limitations in this deep (5136 m along hole, 3700 m true vertical depth, with a maximum deviation of 89 degrees), high pressure well a hydraulic workover unit (HWU) was selected to deploy and retrieve the guns. The operation is considered a world record since this is the longest section (total gross interval of 1026 m perforated) of guns conveyed, fired underbalanced and deployed out of a live well. It is concluded that the improved productivity more than justified the additional time, effort and expenditure; considering the full life cycle of the well it is readily apparent that the operation was an economic and technical success. Details of the considerations leading to the perforating technique selection, the planning and the execution of the operation, and the validation of the technique in terms of productivity gains, are provided. 13 refs., 7 figs.

  14. Subacute right ventricle perforation by pacemaker lead presenting with left hemothorax and shock.

    Science.gov (United States)

    Nichols, Julianne; Berger, Natalie; Joseph, Praveen; Datta, Debapriya

    2015-01-01

    Cardiac perforation by pacemaker is a rare but potentially fatal complication. Acute perforations occurring within twenty-four hours of insertion of pacemaker can lead to hemopericardium, cardiac tamponade, and death. Hemothorax occurring as an acute complication of pacemaker insertion is reported but extremely rare. Previously, hemothorax and shock as a subacute complication following pacemaker insertion have not been reported. We report the case of an 85-year-old patient who presented with shock from hemothorax caused by pacemaker perforation, two weeks after insertion. Device interrogation showed normal function. Chest X-ray and echocardiogram missed lead dislocation and the diagnosis was made on computed tomogram (CT) of the chest. Following surgical repair, a new ventricular pacemaker was placed transvenously in the right ventricular septum. This case illustrates that CT scan of the chest should be performed in all patients in whom cardiac perforation by pacemaker is suspected but not diagnosed on chest X-ray and echocardiogram. Normal functioning of pacemaker on device interrogation does not exclude perforation.

  15. Finite-element modelling and preliminary validation of microneedle-based electrodes for enhanced tissue electroporation.

    Science.gov (United States)

    Houlihan, Ruth; Grygoryev, Konstantin; Zhenfei Ning; Williams, John; Moore, Tom; O'Mahony, Conor

    2017-07-01

    This paper investigates the use of microneedle-based electrodes for enhanced testis electroporation, with specific application to the production of transgenic mice. During the design phase, finite-element software has been used to construct a tissue model and to compare the relative performance of electrodes employing a) conventional flat plates, b) microneedle arrays, and c) invasive needles. Results indicate that microneedle-based electrodes can achieve internal tissue field strengths which are an order of magnitude higher than those generated using conventional flat electrodes, and which are comparable to fields produced using invasive needles. Using a double-sided etching process, conductive microneedle arrays were then fabricated and used in prototype electrodes. In a series of mouse model experiments involving injection of a DNA vector expressing Green Fluorescent Protein (GFP), the performance of flat and microneedle electrodes was compared by measuring GFP expression after electroporation. The main finding, supported by experimental and simulated data, is that use of microneedle-based electrodes significantly enhanced electroporation of testis.

  16. Treatment of oily bilge water by electrocoagulation process using aluminum electrodes

    Science.gov (United States)

    Soeprijanto, Perdani, Adela Dea; Nury, Dennis Farina; Pudjiastuti, Lily

    2017-05-01

    Electrocoagulation is electrochemical water and wastewater treatment technology which is the simplest technology using an electrochemical cell where the supply of DC power is applied to the electrodes, made of aluminum metals, and the electrolyte is oily bilge water. The electrocoagulation of oily bilge water was experimentally conducted in a batch system. Aluminum plates with dimensions of 20 cm ×8 cm × 0.2 cm were used for electrodes and mounted vertically with a distance of 4 cm. These electrodes were then connected to the direct current power supply of 10 V and 10 A. The total area of the effective working plate was 160 cm2 when immersed at a depth of 10 cm to the solutions. The results showed that total dissolved Solids (TDS) decreased from 31.2 to 7.54 mg/l and formation of sludge increased up to 12.54 g/l with oil concentration of 50 g/l for 15 min. The largest oil removal of 99.5% was obtained using the initial oil concentration of 55 g/l and the lowest of 96.25% was obtained with the initial oil concentration of 146.04 g/l. A current density of 62.3 mA/cm2 was achieved for a maximum oil removal.

  17. Percutaneous Emergency Needle Caecostomy for Prevention of Caecal Perforation

    OpenAIRE

    Limmer, Alexandra M.; Clement, Zackariah

    2017-01-01

    Caecal perforation is a life-threatening complication of large bowel obstruction with a reported mortality of 34% to 72%. This case describes the novel use of percutaneous needle caecostomy as a life-saving measure to prevent imminent caecal perforation in a 68-year-old lady with large bowel obstruction secondary to an incarcerated incisional hernia. After careful review of computed tomography images and measurement of distances from the abdominal wall to the caecum, the patient's caecum was ...

  18. A Spectral Active Material Interference in the Electrical Conductivity of the Internal Electrolyte and the Potential Shift of the Ag/AgCl Electrode

    International Nuclear Information System (INIS)

    Yun, Myung Hee; Yeon, Jei Won; Hwang, Jae Sik; Song, Kyu Seok

    2009-01-01

    The Ag/AgCl electrode is a type of reference electrode, commonly used in electrochemical measurements, because it is simple and stable. For these reasons, the Ag/AgCl electrode has long been used to provide a reliable potential monitoring of ions in a solution. However, when a reference electrode is used in an aqueous solution containing a very low electrolyte for a long period of time, this could cause a considerable potential shift of the reference electrode due to a dilution of the internal electrolyte. If the potential of the reference electrode shifts, undesirable conditions may occur. Therefore, many studies have been applied to improve the long-term performance of the reference electrode. However, these attempts have not completely resolved the problem of an electrolyte dilution by the test solution. In the present study, we developed a creative technique to correct the concentration change of the internal electrolyte by a long-term exposure of the Ag/AgCl electrode in very dilute solutions. We measured the electrical conductivity and UV/VIS absorbance of the internal electrolyte. From these measurements, we observed the linear relationship between KCl concentration and the potential of the Ag/AgCl electrode. In order to accelerate the diffusion of the internal electrolyte into the test solution, an Ag/AgCl electrode with a tiny perforation was used. We confirmed the feasibility of the creative calibration technique

  19. Evaluation of risk factors for mortality in perforated peptic ulcer in ...

    African Journals Online (AJOL)

    Objective: To assess the risk factor that influence mortality from perforated peptic ulcer. Design: Retrospective study. Setting: Ankara Numune Teaching and Research Hospital, Ankara, Turkey. Subjects: A total of 342 patients with perforated peptic ulcer disease were identified from April 1997 to January 2004. Data for the ...

  20. Clinical and pathological outcomes after irreversible electroporation of the pancreas using two parallel plate electrodes: a porcine model.

    Science.gov (United States)

    Rombouts, Steffi J E; van Dijck, Willemijn P M; Nijkamp, Maarten W; Derksen, Tyche C; Brosens, Lodewijk A A; Hoogwater, Frederik J H; van Leeuwen, Maarten S; Borel Rinkes, Inne H M; van Hillegersberg, Richard; Wittkampf, Fred H; Molenaar, Izaak Q

    2017-12-01

    Irreversible electroporation (IRE) by inserting needles around the tumor as treatment for locally advanced pancreatic cancer entails several disadvantages, such as incomplete ablation due to field inhomogeneity, technical difficulties in needle placement and a risk of pancreatic fistula development. This experimental study evaluates outcomes of IRE using paddles in a porcine model. Six healthy pigs underwent laparotomy and were treated with 2 separate ablations (in head and tail of the pancreas). Follow-up consisted of clinical and laboratory parameters and contrast-enhanced computed tomography (ceCT) imaging. After 2 weeks, pancreatoduodenectomy was performed for histology and the pigs were terminated. All animals survived 14 days. None of the animals developed signs of infection or significant abdominal distention. Serum amylase and lipase peaked at day 1 postoperatively in all pigs, but normalized without signs of pancreatitis. On ceCT-imaging the ablation zone was visible as an ill-defined, hypodense lesion. No abscesses, cysts or ascites were seen. Histology showed a homogenous fibrotic lesion in all pigs. IRE ablation of healthy porcine pancreatic tissue using two plate electrodes is feasible and safe and creates a homogeneous fibrotic lesion. IRE-paddles should be tested on pancreatic adenocarcinoma to determine the effect in cancer tissue. Copyright © 2017. Published by Elsevier Ltd.

  1. Improving Impedance of Implantable Microwire Multi-Electrode Arrays by Ultrasonic Electroplating of Durable Platinum Black

    Science.gov (United States)

    Desai, Sharanya Arcot; Rolston, John D.; Guo, Liang; Potter, Steve M.

    2010-01-01

    Implantable microelectrode arrays (MEAs) have been a boon for neural stimulation and recording experiments. Commercially available MEAs have high impedances, due to their low surface area and small tip diameters, which are suitable for recording single unit activity. Lowering the electrode impedance, but preserving the small diameter, would provide a number of advantages, including reduced stimulation voltages, reduced stimulation artifacts and improved signal-to-noise ratio. Impedance reductions can be achieved by electroplating the MEAs with platinum (Pt) black, which increases the surface area but has little effect on the physical extent of the electrodes. However, because of the low durability of Pt black plating, this method has not been popular for chronic use. Sonicoplating (i.e. electroplating under ultrasonic agitation) has been shown to improve the durability of Pt black on the base metals of macro-electrodes used for cyclic voltammetry. This method has not previously been characterized for MEAs used in chronic neural implants. We show here that sonicoplating can lower the impedances of microwire multi-electrode arrays (MMEA) by an order of magnitude or more (depending on the time and voltage of electroplating), with better durability compared to pulsed plating or traditional DC methods. We also show the improved stimulation and recording performance that can be achieved in an in vivo implantation study with the sonicoplated low-impedance MMEAs, compared to high-impedance unplated electrodes. PMID:20485478

  2. The ectopic appendicolith from perforated appendicitis as a cause of tubo-ovarian abscess

    International Nuclear Information System (INIS)

    Vyas, Rajashree C.; Sides, Corey; Klein, Deborah J.; Reddy, Sireesha Y.; Santos, Mary C.

    2008-01-01

    Acute appendicitis is a common surgical cause of abdominal pain in the pediatric population. History and physical examination are atypical in up to a third of patients. Known potential complications of untreated or delayed management of acute appendicitis include appendiceal perforation, periappendiceal abscess formation, peritonitis, bowel obstruction and rarely septic thrombosis of mesenteric vessels. We report an unusual complication of perforated appendicitis. A tubo-ovarian abscess developed secondary to appendicolith migration into the right fallopian tube in a patient who had undergone interval laparoscopic appendectomy for perforated appendicitis. The retained appendicolith was visualized within the obstructed and dilated fallopian tube on contrast-enhanced CT. We discuss the CT imaging features of this unusual complication of perforated appendicitis. (orig.)

  3. The ectopic appendicolith from perforated appendicitis as a cause of tubo-ovarian abscess

    Energy Technology Data Exchange (ETDEWEB)

    Vyas, Rajashree C.; Sides, Corey; Klein, Deborah J. [University of Rochester Medical Center, Rochester, NY (United States); Reddy, Sireesha Y. [University of Rochester, Obstetrics and Gynecology, Rochester, NY (United States); Santos, Mary C. [University of Rochester, Pediatric Surgery, Rochester, NY (United States)

    2008-09-15

    Acute appendicitis is a common surgical cause of abdominal pain in the pediatric population. History and physical examination are atypical in up to a third of patients. Known potential complications of untreated or delayed management of acute appendicitis include appendiceal perforation, periappendiceal abscess formation, peritonitis, bowel obstruction and rarely septic thrombosis of mesenteric vessels. We report an unusual complication of perforated appendicitis. A tubo-ovarian abscess developed secondary to appendicolith migration into the right fallopian tube in a patient who had undergone interval laparoscopic appendectomy for perforated appendicitis. The retained appendicolith was visualized within the obstructed and dilated fallopian tube on contrast-enhanced CT. We discuss the CT imaging features of this unusual complication of perforated appendicitis. (orig.)

  4. Intestinal volvulus and perforation caused by multiple magnet ingestion: report of a case.

    Science.gov (United States)

    Ilçe, Zekeriya; Samsum, Hakan; Mammadov, Emil; Celayir, Sinan

    2007-01-01

    Ingested magnets can cause intestinal fistulas, perforation, and obstruction. There have been reports of magnet ingestion causing intestinal volvulus, but multiple magnet ingestion causing perforation and intestinal volvulus in a child is very unusual. We report the case of a 4-year-old girl, who ingested four magnets she acquired as toys, which caused intestinal volvulus and perforation as a result of pressure necrosis, several days after ingestion. At surgery we repaired two perforations, but additional bowel resection was not required. The patient was discharged on postoperative day 10. If multiple magnet ingestion is suspected in a child, the child must be monitored carefully. If there are signs of obstruction, emergency surgery is mandatory.

  5. Conservative treatment of perforated upper gastrointestinal tract

    International Nuclear Information System (INIS)

    Naoi, Daishi; Sano, Wataru; Nakata, Yasuyuki; Yano, Kentaro; Suzuki, Takeshi; Chiku, Tsuyoshi; Tashiro, Tsuguhiko

    2009-01-01

    In order to clarify the validity of indication criteria of the conservative treatment for perforated upper gastrointestinal tract, a retrospective study was carried out. We enrolled 28 patients with perforation of the gastrointestinal tract who were determined to receive conservative treatment at the time of hospitalization from January 2000 to December 2007. When the following criteria were satisfied, we treated the patients by the conservative treatment after informed consent was gained from them and their families: stable condition of vital signs; peritoneal signs localized in the upper abdomen; and no or slight fluid collection at the Douglas' pouch determined by computed tomography. Patients who showed changes for the worse of peritonitis or increased fluid collection during follow-up were promptly converted to surgery. Six patients were converted to surgery, but all of them were discharged very much improved. We compared patient's data of the conservative treatment group and the converted surgery group at the time of consultation. All data were not statistically different between two groups. If all criteria are satisfied, it seemed that we can start conservative treatment for perforated gastrointestinal tract with careful observation and the system of prompt conversion to operation for patients who showed changes for the worse of peritonitis or increased fluid collection. (author)

  6. Colorectal cancer complicated by perforation. Specific features of surgical tactics

    Directory of Open Access Journals (Sweden)

    S. N. Shchaeva

    2015-01-01

    Full Text Available Objective: to assess the immediate results of surgical interventions for colorectal cancer complicated by perforation.Materials and methods. The immediate results of surgical treatment were retrospectively analyzed in 56 patients with colorectal cancer complicated by perforated colon cancer, who had been treated at Smolensk surgical hospitals in 2001 to 2013. Patients with diastatic perforation of the colon in the presence of decompensated obturation intestinal obstruction of tumor genesis were not included into this investigation.Results. The immediate results of uni- and multistage surgical interventions were analyzed in relation to the extent of peritonitis and the stage of colon cancer. More satisfactory immediate results were observed after multistage surgical treatment. Following these interventions, a fatal outcome of disseminated peritonitis in the presence of performed colorectal cancer was recorded in 8 (53.3 % cases whereas after symptomatic surgery there were 11 (67.8 % deaths. A fatal outcome was noted in 1 case (7.7 % after multistage surgery.Discussion. The results of surgical treatment in the patients with perforated colorectal cancer are directly related to the degree of peritonitis and the choice of surgical tactics.

  7. COMPARATIVE ANALYSIS OF PRIMARY REPAIR VERSUS RESECTION AND ANASTOMOSIS IN JEJUNOILEAL PERFORATIONS IN SOUTHERN ODISHA

    Directory of Open Access Journals (Sweden)

    Charan Panda

    2017-11-01

    Full Text Available BACKGROUND Small intestinal perforation remains a major issue in this region of study. Most often, it is caused by either infections due to typhoid, tuberculosis or traumatic due to blunt or penetrating injuries. The mortality reported is related to various factors including age, delayed treatment, sepsis at presentation and inadequate treatment due to lack of resources. Management is therefore complex not only with regards to choose the most suitable surgical treatment, but also as regards an early diagnosis of complications, which is difficult in absence of diagnostic modalities that are often not available. The aim of the study is to compare primary repair versus intestinal resection and anastomosis in case of jejunoileal perforations due to various aetiologies. MATERIALS AND METHODS 60 patients with acute peritonitis underwent emergency laparotomy. Aetiology, number of perforations, size of perforations, site of perforations, surgical procedure undertaken and postoperative complications were recorded. The patients were divided into two groups according to the surgical procedure adapted at laparotomy; primary repair and intestinal resection and anastomosis. Clinical data, intraoperative findings and complications were evaluated and compared. RESULTS 40 out of 60, we found jejunoileal perforations, gastroduodenal in 20 patients. 23 had undergone primary repair and 17 resection and anastomosis. Postoperative complications were compared among both groups in relation to various factors. Conclusion was drawn as to prefer, which surgery in which group of patients. CONCLUSION In our study, detailed analysis of the complication pattern shows primary closure is associated with less number of complications in traumatic cases and resection and anastomosis is associated with lesser complications in infective cases. Primary closure is less complicated for single perforations as compared to multiple perforations. Resection and anastomosis is less

  8. Iatrogenic stomach perforation complicating unrecognized ...

    African Journals Online (AJOL)

    We report a case of 21-year-old male patient with traumatic diaphragmatic herniation of the stomach that is misdiagnosed as a hemo-pneumothorax with the resulting insertion of a chest tube causing iatrogenic perforation of the stomach and draining of gastric content into the pleural cavity. An emergency thoracotomy was ...

  9. Augmented reality and dynamic infrared thermography for perforator mapping in the anterolateral thigh.

    Science.gov (United States)

    Cifuentes, Ignacio Javier; Dagnino, Bruno Leonardo; Salisbury, María Carolina; Perez, María Eliana; Ortega, Claudia; Maldonado, Daniela

    2018-05-01

    Dynamic infrared thermography (DIRT) has been used for the preoperative mapping of cutaneous perforators. This technique has shown a positive correlation with intraoperative findings. Our aim was to evaluate the accuracy of perforator mapping with DIRT and augmented reality using a portable projector. For this purpose, three volunteers had both of their anterolateral thighs assessed for the presence and location of cutaneous perforators using DIRT. The obtained image of these "hotspots" was projected back onto the thigh and the presence of Doppler signals within a 10-cm diameter from the midpoint between the lateral patella and the anterior superior iliac spine was assessed using a handheld Doppler device. Hotspots were identified in all six anterolateral thighs and were successfully projected onto the skin. The median number of perforators identified within the area of interest was 5 (range, 3-8) and the median time needed to identify them was 3.5 minutes (range, 3.3-4.0 minutes). Every hotspot was correlated to a Doppler sound signal. In conclusion, augmented reality can be a reliable method for transferring the location of perforators identified by DIRT onto the thigh, facilitating its assessment and yielding a reliable map of potential perforators for flap raising.

  10. Increased Flap Weight and Decreased Perforator Number Predict Fat Necrosis in DIEP Breast Reconstruction

    Directory of Open Access Journals (Sweden)

    Carolyn L. Mulvey, BS

    2013-05-01

    Conclusions: Flaps with increasing weight have increased risk of fat necrosis. These data suggest that inclusion of more than 1 perforator may decrease odds of fat necrosis in large flaps. Perforator flap breast reconstruction can be performed safely; however, considerations concerning race, body mass index, staging with tissue expanders, perforator number, and flap weight may optimize outcomes.

  11. A shovel with a perforated blade reduces energy expenditure required for digging wet clay.

    Science.gov (United States)

    Harivanam, Sridhar; Marklin, Richard W; Papanek, Paula E; Cariapa, Vikram

    2010-08-01

    A shovel with a blade perforated with small holes was tested to see whether a worker would use less whole-body energy to dig wet clay than with a shovel with an opaque blade. A perforated shovel is hypothesized to require less whole-body energy on the basis of adhesion theory; a smaller surface area would require less physical effort to dig and release soil from the blade. The study involved 13 workers from an electric utility who dug wet clay with two 1.5-m long-handled point shovels, which differed only in blade design (perforated and opaque). Oxygen consumption was measured with a portable system while each worker dug wet clay at a self-regulated pace for 10 min. There was no significant difference in number of scoops dug during the 10-min sessions, but workers dug 9.5% more weight of clay with the perforated shovel than with the conventional shovel (404 kg vs. 369 kg, respectively). Furthermore, stable oxygen uptake normalized to weight of participant and to the weight of clay dug revealed that participants expended 11.7% less relative energy per kilogram of clay dug with the perforated shovel. A point shovel with a perforated blade is recommended for digging and shoveling wet clay. However, the extra weight that workers chose to dig with the perforated shovel may increase the loading on the spine and may offset the metabolic advantages. Manual shoveling is a common task, and workers may experience less whole-body and muscle fatigue when using a perforated shovel.

  12. Colorectal cancer with intestinal perforation – a retrospective analysis of treatment outcomes

    Science.gov (United States)

    Woda, Łukasz; Tojek, Krzysztof; Jarmocik, Paweł; Jawień, Arkadiusz

    2014-01-01

    Aim of the study Colorectal cancer (CRC) is one of the leading cause of death in European population. It progresses without any symptoms in the early stages or those clinical symptoms are very discrete. The aim of this study was a retrospective analysis of treatment outcomes in patients with colorectal cancer complicated with intestinal perforation. Material and methods A retrospective analysis of patients urgently operated upon in our Division of General Surgery, because of large intestine perforation, from February 1993 to February 2013 has been made. Results were compared with a group of patients undergoing the elective surgery for colorectal cancer in the same time and Division. Results Intestinal perforation occurred more often in males (6.52% vs. 6.03%), patients with mucous component in histopathological examination (9.09% vs. 6.01%) and with clinicaly advanced CRC. Patients treated because of perforation had a five-fold higher 30 day mortality rate (9.09% vs. 1.83%), however long-term survival did not differ significantly in both groups. After resectional surgery in 874 patients an intestinal anastomosis was made. Anastomotic leakage was present in 23 (2.6%) patients. This complication occurred six-fold more frequently in a group of patients operated upon because of intestinal perforation (12.20% vs. 2.16%). Conclusions In patients with CRC complicated with perforation of the colon in a 30-day observation significantly higher rate of complications and mortality was shown, whereas there was no difference in distant survival rates. PMID:25784840

  13. A theoretical model describing arterial flow in the DIEP flap related to number and size of perforator vessels.

    Science.gov (United States)

    Patel, Sameer A; Keller, Alex

    2008-11-01

    The deep inferior epigastric perforator flap is rapidly becoming a more widely employed method of autologous breast reconstruction. The technical considerations involved in the execution of the flap are many and include the selection of perforators to be incorporated in the flap. We attempt to give a mathematical explanation, based on the physics of flow through vessels and the properties of circuits with multiple resistances in parallel, for the clinical observations which have been arrived at through clinical experience. We compare the system of perforators to a circuit with multiple resistances in parallel. Each of these resistances represents a perforator vessel. In the event that there is only one perforator vessel, this simplifies to a single resistance in series with the capillary bed perfusing the flap. The flow through the flap is optimized by incorporation of the largest diameter perforator. Inclusion of other smaller perforators in addition to the largest diameter perforator will reduce the overall resistance, but this reduction in resistance is dependent on the diameter of the additional perforator and may not be worth the additional trauma of dissection and increased operative time. Incorporating several smaller perforators at the expense of excluding the largest diameter perforator appears to increase the overall resistance, unless the smaller perforators are only slightly smaller. We conclude that the best perfused flap involves use of the largest diameter vessel, that although adding additional perforators will decrease the resistance and increase flow, the magnitude of the benefit depends largely on the calibre of the additional perforator, and that this benefit needs to be weighed against the downside of increased muscle and facial trauma.

  14. Perforation of dental gloves during prosthodontic treatments as assessed by the conductivity and water inflation tests.

    Science.gov (United States)

    Nikawa, H; Hamada, T; Tamamoto, M; Abekura, H; Murata, H

    1996-01-01

    The incidence of latex glove perforation during prosthodontic treatment was investigated on 122 occasions using two methods, a conductivity test and a water inflation test. Latex glove perforation was detected in 38.5% of the treatments by the conductivity test and in 27.9% by the water inflation test. The perforation went unrecognized in 74.7% of the occurrences (35/47 incidents) using the conductivity test and in 64.7% (22/34) when the water inflation test was used. Of the total 55 glove perforations, 21 perforations were detected only by conductivity test, 3 were detected only by the water inflation test, and 31 perforations were detected by both methods, which suggested that the conductivity test is more sensitive than the water inflation test for the detection of glove perforation. The results of this research suggested that even when latex gloves are worn, the risk to prosthodontists of exposure to body fluids remains in four of every six treatments, often without the awareness of the prosthodontist.

  15. Optical and acoustic sensing using Fano-like resonances in dual phononic and photonic crystal plate

    Energy Technology Data Exchange (ETDEWEB)

    Amoudache, Samira [Institut d' Electronique, de Microélectronique et de Nanotechnologie, Université de Lille 1, 59655 Villeneuve d' Ascq (France); Laboratoire de Physique et Chimie Quantique, Université Mouloud Mammeri, B.P. 17 RP, 15000 Tizi-Ouzou (Algeria); Moiseyenko, Rayisa [Department of Physics, Technical University of Denmark, DTU Physics, Building 309, DK-2800 Kongens Lyngby (Denmark); Pennec, Yan, E-mail: yan.pennec@univ-lille1.fr; Rouhani, Bahram Djafari [Institut d' Electronique, de Microélectronique et de Nanotechnologie, Université de Lille 1, 59655 Villeneuve d' Ascq (France); Khater, Antoine [Institut des Molécules et Matériaux du Mans (IMMM), UMR CNRS 6283, l' UNAM, Université du Maine, 72085 Le Mans (France); Lucklum, Ralf [Institute of Micro and Sensor Systems (IMOS), Otto-von-Guericke-University, P.O. Box 4120, D-39016 Magdeburg (Germany); Tigrine, Rachid [Laboratoire de Physique et Chimie Quantique, Université Mouloud Mammeri, B.P. 17 RP, 15000 Tizi-Ouzou (Algeria)

    2016-03-21

    We perform a theoretical study based on the transmissions of optical and acoustic waves normally impinging to a periodic perforated silicon plate when the embedded medium is a liquid and show the existence of Fano-like resonances in both cases. The signature of the resonances appears as well-defined asymmetric peaks in the phononic and photonic transmission spectra. We show that the origin of the Fano-like resonances is different with respect to the nature of the wave. In photonic, the origin comes from guided modes in the photonic plate while in phononic we show that it comes from the excitation of standing waves confined inside the cavity coming from the deformation of the water/silicon edges of the cylindrical inclusion. We finally use these features for sensing and show ultra-sensitivity to the light and sound velocities for different concentrations of analytes.

  16. Neonatal gastric perforation: a report of 3 cases and literature review ...

    African Journals Online (AJOL)

    Neonatal gastric perforation (NGP) is an uncommon disease. Historical reports regard the aetiology as spontaneous while the mortality remains high. We present the report of the cases of neonatal gastric perforations who presented to our facility, its diverse aetiology and a review of the literature. Their clinical data including ...

  17. Persistent perforation in non-faeculant diverticular peritonitis--incidence and clinical significance.

    LENUS (Irish Health Repository)

    O'Leary, D P

    2013-02-01

    Non-resectional strategies (NRS) have improved outcomes for a sub-group of patients with perforated diverticulitis. NRS are applicable to patients with non-faeculant peritonitis (Hinchey II and III). Success is dependent on the initial perforation sealing, which Hinchey estimated occurred \\'most of the time\\'. An exact percentage remains ill-defined.

  18. Comparison of differently viscous iodinated and bariumcontaining contrast agents in the detection of pharyngeal perforation

    International Nuclear Information System (INIS)

    Keberle, M.; Wittenberg, G.; Trusen, A.; Hahn, D.; Baumgartner, W.

    2001-01-01

    Purpose: In contrast to esophageal perforations, the more radiopaque barium-suspensions are not as important as iodinated aqueous contrast agents for the detection of pharyngeal perforations. This study was performed to find out whether the highly different viscosities (of iodinated and barium-containing contrast agents with comparable radiopacities) are a reason for this. Methods: Viscosity, subjective difference in contrast, and CT-density of an iodinated aqueous (Telebrix) and a 50 wt/vol% barium-containing contrast agent (Micropaque) were determined. Moreover, to exclude postoperative perforation, 104 patients were prospectively examined by pharyngography using both contrast media. Pharyngographies of patients with perforation were later compared by two independent readers. All patients with perforation were followed up clinically to exclude complications due to barium administration. Results: In-vitro comparison showed comparable radiopacity but the 50 wt/vol% barium-suspension was much more viscous that the iodinated contrast agent. During pharyngography, totally, 14 perforations were clearly delineated with the iodinated aqueous contrast agent. However, two of them were not detected with the barium-suspension. All the other perforations presented equally. Conclusions: Given a sufficient radiopacity, a low viscosity appears to be essential for a contrast agent to detect especially pharyngeal perforations. Thus, we recommend the sole use of an iodinated contrast agent (at suspicion of aspiration as isoosmolar variant) for this purpose. (orig.) [de

  19. Study of skin and mucous membrane disorders among workers engaged in the sodium dichromate manufacturing industry and chrome plating industry.

    Science.gov (United States)

    Singhal, Vijay Kumar; Deswal, Balbir Singh; Singh, Bachu Narayan

    2015-01-01

    Inhalation of dusts and fumes arising during the manufacture of sodium dichromate from chrome ore, chromic acid mist emitted during electroplating, and skin contact with chromate produce hazards to workers. (1) To elucidate the prevalence of skin and mucous membrane disorders among the workers engaged in the sodium dichromate manufacturing industry and chrome plating industry. (2) To know the relationship of prevalence with the duration of exposure to chrome mist, dust, and fumes. A cross-sectional study was conducted among all the workers engaged in sodium dichromate manufacturing and chrome plating from several industries situated near the Delhi-Haryana border in the districts of Faridabad and Sonepat of Haryana, India from January 01, 2014 to December 31, 2014. All the workers available from the concerned industries for the study were interviewed and medically examined after obtaining their informed consent. A total of 130 workers comprising 66 workers from the sodium dichromate manufacturing industry and 64 workers from the chrome plating industry were examined on a pretested schedule. Descriptive statistical methods (proportions, relative risk, and Chi-square test of significance with P value analyzed using Epi Info version 7). All the workers were found to be males and of the adult age group. Out of the total examined, 69.69% and 56.22% of the workers had disorders of the nasal mucous membrane in the sodium dichromate manufacturing industry and the chrome plating industry, respectively. 42.42% and 28.22% of the workers had perforation of the nasal septum in the sodium dichromate manufacturing industry and chrome plating industry, respectively. 6.06% and 3.12% workers had skin ulcers in the sodium dichromate manufacturing industry and chrome plating industry, respectively. Nasal irritation and rhinorrhea were the most commonly found symptoms in both the processes. 48.48% and 90.52% of the workers were using hand gloves in the sodium dichromate manufacturing

  20. Development of parallel-plate-based MEMS tunable capacitors with linearized capacitance–voltage response and extended tuning range

    International Nuclear Information System (INIS)

    Shavezipur, M; Nieva, P; Khajepour, A; Hashemi, S M

    2010-01-01

    This paper presents a design technique that can be used to linearize the capacitance–voltage (C–V) response and extend the tuning range of parallel-plate-based MEMS tunable capacitors beyond that of conventional designs. The proposed technique exploits the curvature of the capacitor's moving electrode which could be induced by either manipulating the stress gradients in the plate's material or using bi-layer structures. The change in curvature generates a nonlinear structural stiffness as the moving electrode undergoes out-of-plane deformation due to the actuation voltage. If the moving plate curvature is tailored such that the capacitance increment is proportional to the voltage increment, then a linear C–V response is obtained. The larger structural resistive force at higher bias voltage also delays the pull-in and increases the maximum tunability of the capacitor. Moreover, for capacitors containing an insulation layer between the two electrodes, the proposed technique completely eliminates the pull-in effect. The experimental data obtained from different capacitors fabricated using PolyMUMPs demonstrate the advantages of this design approach where highly linear C–V responses and tunabilities as high as 1050% were recorded. The design methodology introduced in this paper could be easily extended to for example, capacitive pressure and temperature sensors or infrared detectors to enhance their response characteristics.