Characterization of a porcine model of chronic superficial varicose veins.

Science.gov (United States)

Jones, Gregory T; Grant, Mark W; Thomson, Ian A; Hill, B Geraldine; van Rij, André M

2009-06-01

Previous animal models of venous disease, while inducing venous hypertension and valvular insufficiency, do not produce superficial varicose veins. In this study, we aimed to develop and characterize a pig-based model of superficial varicose veins. Right femoral arteriovenous fistulae (AVF) were surgically fashioned in young adult pigs. Animals were examined at postoperative times up to 15 weeks to determine the development of varicose veins and measurement of both blood pressure and flow velocities within the superficial thigh veins. Histology and vascular corrosion casts were used to characterize the resulting structural venous alterations. Porcine pathophysiological features were compared with those of human primary superficial varicose veins. Gross superficial varicosities developed over the ipsilateral medial thigh region after an initial lag period of 1-2 weeks. Veins demonstrated retrograde filling with valvular incompetence, and a moderate, non-pulsatile, venous hypertension, which was altered by changes in posture and Valsalva. Venous blood flow velocities were elevated to 15-30 cm/s in varicose veins. Structurally, pig varicose veins were enlarged, tortuous, had valvular degeneration, and regions of focal medial atrophy with or without overlying intimal thickening. The superficial varicose veins, which developed within this model, have a pathophysiology that is consistent with that observed in humans. The porcine femoral AVF model is proposed as a suitable experimental model to evaluate the pathobiology of superficial venous disease. It may also be suitable for the evaluation of treatment interventions including drug therapy.

The Effect of Air Velocity on the Prevention of Heat Stress in Iranian Veiled Females

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Habibi

2016-09-01

Full Text Available Background Some environmental factors such as the ambient temperature, radiant temperature, humidity and air velocity as well as clothing and activity level are effective to induce heat strain on the workers. Objectives The current study aimed to evaluate the effect of air velocity on Iranian veiled females at various exercise intensities and climatic conditions. Methods The current experimental study was conducted on 51 healthy veiled females with Islamic clothing (n = 30 in two hot-dry climatic chambers (wet-bulb globe temperature (WBGT = 32 ± 0.1°C and WBGT = 30 ± 0.1°C, 40% relative humidity (RH without air velocity and (n = 21 with air velocity 0.31 m/s in sitting and light workload conditions, respectively, for 60 minutes. The WBGT, oral temperature and heart rate were measured simultaneously every five minutes during the heat exposure and resting state. Data were analyzed using correlation and line regression by SPSS ver. 16. Results In both groups, oral temperature and heart rate increased during heat exposure. The increase of oral temperature and heart rate were larger in the group with air velocity (sitting position, 37.05 ± 0.20°C, 98.30 ± 7.79 bpm, light workload, 37.34 ± 0.24°C, 124.08 ± 6.09 bpm compared those of the group without air velocity (sitting position, 36.70 ± 0.36°C, 69.74 ± 0.98 bpm, light workload, 36.71 ± 0.27°C, 110.78 ± 17.9 bpm. The difference in physiological strain index (PSI between resting and low workload were higher in with air velocity group than those of the group without air velocity. Conclusions The results showed that the heat stress increased by increasing air velocity and humidity in both groups. The air velocity with high humidity can be considered as a positive factor in the occurrence of heat strain. Therefore, the incidence of heat stress decreases with the increase of humidity and reduction of air velocity or with increase of air velocity and reduction of humidity in Iranian veiled

Effect of operating conditions on performance of silica gel-water air-fluidised desiccant cooler

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Rogala Zbigniew

2017-01-01

Full Text Available Fluidised desiccant cooling is reported in the literature as an efficient way to provide cooling for air-conditioning purposes. The performance of this technology can be described by electric and thermal Coefficients of Performance (COP and Specific Cooling Power (SCP. In this paper comprehensive theoretical study was carried out in order to assess the effect of operating conditions such as: superficial air velocity, desiccant particle diameter, bed switching time and desiccant filling height on the performance of fluidised desiccant cooler (FDC. It was concluded that FDC should be filled with as small as possible desiccant particles featuring diameters and should not be operated with shorter switching times than optimum. Moreover in order to efficiently run such systems superficial air velocities during adsorption and desorption should be similar. At last substantial effect of desiccant filling height on performance of FDC was presented.

Shock velocity in weakly ionized nitrogen, air, and argon

International Nuclear Information System (INIS)

Siefert, Nicholas S.

2007-01-01

The goal of this research was to determine the principal mechanism(s) for the shock velocity increase in weakly ionized gases. This paper reports experimental data on the propagation of spark-generated shock waves (1< Mach<3) into weakly ionized nitrogen, air, and argon glow discharges (1 < p<20 Torr). In order to distinguish between effects due solely to the presence of electrons and effects due to heating of the background gas via elastic collisions with electrons, the weakly ionized discharge was pulsed on/off. Laser deflection methods determined the shock velocity, and the electron number density was collected using a microwave hairpin resonator. In the afterglow of nitrogen, air, and argon discharges, the shock velocity first decreased, not at the characteristic time for electrons to diffuse to the walls, but rather at the characteristic time for the centerline gas temperature to equilibrate with the wall temperature. These data support the conclusion that the principal mechanism for the increase in shock velocity in weakly ionized gases is thermal heating of the neutral gas species via elastic collisions with electrons

Measurement of air velocity in animal occupied zones using an ultrasonic anemometer

NARCIS (Netherlands)

Wagenberg, van A.V.; Leeuw, de M.T.J.

2003-01-01

The air velocity in the animal occupied zone (AOZ) of a pig facility influences the thermal comfort of pigs and is affected by the ventilation system in the building. Little is known about the relationship between the air velocity in the AOZ and the ventilation system design. This article describes

The effects of baffles and gas superficial velocity on a bubble fluidized bed reactor's applications

International Nuclear Information System (INIS)

Ghorbanpour, A.; Ghannadi Maragheh, M.; Mallah, M. H.

2008-01-01

Baffles are used for decreasing bubbles diameter in order to increase the conversion rate along the bubbling fluidized bed reactors. The appearance of this phenomenon is due to bursting of the bubbles during the pass of bubbles from baffles. In this work, a computerized modeling and simulation have been performed in order to obtain a fundamental knowledge of the influence of the baffles on the bubble diameter and the specific mass transfer area. The height of the bed is 5 meters and its diameter is 0.3 meter. Baffles are located at 1 and 2 meters from the bottom of the bed. A two phase model together with a comprehensive fluid dynamical description of bubbling fluidized is presented. The effects of baffles and gas superficial velocity on the operating behavior of fluidized bed reactors are considered. The results are compared to the previously reported documents, and the experiments which have been carried out. MATLAB software is used in this simulation

Performance Investigation of Air Velocity Effects on PV Modules under Controlled Conditions

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Muzaffar Ali

2017-01-01

Full Text Available Junction temperature of PV modules is one of the key parameters on which the performance of PV modules depends. In the present work, an experimental investigation was carried out to analyze the effects of air velocity on the performance of two PV modules, that is, monocrystalline silicon and polycrystalline silicon under the controlled conditions of a wind tunnel in the presence of an artificial solar simulator. The parameters investigated include the surface temperature variation, power output, and efficiency of PV modules under varying air velocity from near zero (indoor lab. conditions to 15 m/s. Additionally, the results were also determined at two different module angular positions: at 0° angle, that is, parallel to air direction and at 10° angle with the direction of coming air to consider the effects of tilt angles. Afterwards, the thermal analysis of the modules was performed using Ansys-Fluent in which junction temperature and heat flux of modules were determined by applying appropriate boundary conditions, such as air velocity, heat flux, and solar radiation. Finally, the numerical results are compared with the experiment in terms of junction temperatures of modules and good agreement was found. Additionally, the results showed that the maximum module temperature drops by 17.2°C and the module efficiency and power output increased from 10 to 12% with increasing air velocity.

Thermistor based, low velocity isothermal, air flow sensor

International Nuclear Information System (INIS)

Cabrita, Admésio A C M; Mendes, Ricardo; Quintela, Divo A

2016-01-01

The semiconductor thermistor technology is applied as a flow sensor to measure low isothermal air velocities (<2 ms −1 ). The sensor is subjected to heating and cooling cycles controlled by a multifunctional timer. In the heating stage, the alternating current of a main AC power supply source guarantees a uniform thermistor temperature distribution. The conditioning circuit assures an adequate increase of the sensors temperature and avoids the thermal disturbance of the flow. The power supply interruption reduces the consumption from the source and extends the sensors life time. In the cooling stage, the resistance variation of the flow sensor is recorded by the measuring chain. The resistive sensor parameters proposed vary significantly and feature a high sensitivity to the flow velocity. With the aid of a computer, the data transfer, storage and analysis provides a great advantage over the traditional local anemometer readings. The data acquisition chain has a good repeatability and low standard uncertainties. The proposed method measures isothermal air mean velocities from 0.1 ms −1 to 2 ms −1 with a standard uncertainty error less than 4%. (paper)

Laminar Flame Velocity and Temperature Exponent of Diluted DME-Air Mixture

Science.gov (United States)

Naseer Mohammed, Abdul; Anwar, Muzammil; Juhany, Khalid A.; Mohammad, Akram

2017-03-01

In this paper, the laminar flame velocity and temperature exponent diluted dimethyl ether (DME) air mixtures are reported. Laminar premixed mixture of DME-air with volumetric dilutions of carbon dioxides (CO2) and nitrogen (N2) are considered. Experiments were conducted using a preheated mesoscale high aspect-ratio diverging channel with inlet dimensions of 25 mm × 2 mm. In this method, flame velocities are extracted from planar flames that were stabilized near adiabatic conditions inside the channel. The flame velocities are then plotted against the ratio of mixture temperature and the initial reference temperature. A non-linear power law regression is observed suitable. This regression analysis gives the laminar flame velocity at the initial reference temperature and temperature exponent. Decrease in the laminar flame velocity and increase in temperature exponent is observed for CO2 and N2 diluted mixtures. The addition of CO2 has profound influence when compared to N2 addition on both flame velocity and temperature exponent. Numerical prediction of the similar mixture using a detailed reaction mechanism is obtained. The computational mechanism predicts higher magnitudes for laminar flame velocity and smaller magnitudes of temperature exponent compared to experimental data.

Penetration of Liquid Jets into a High-velocity Air Stream

Science.gov (United States)

Chelko, Louis J

1950-01-01

Data are presented showing the penetration characteristics of liquid jets directed approximately perpendicular to a high-velocity air stream for jet-nozzle-throat diameters from 0.0135 to 0.0625 inch, air stream densities from 0.0805 to 0.1365 pound per cubic foot, liquid jet velocities from 168.1 to 229.0 feet per second and a liquid jet density of approximately 62 pounds per cubic foot. The data were analyzed and a correlation was developed that permitted the determination of the penetration length of the liquid jet for any operation condition within the range of variables investigated.

Modelado físico de la incidencia de un chorro de aire sobre una superficie de agua

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Zenit, R.

2010-10-01

Full Text Available The use of gas jets (oxygen plays a key role in several steelmaking processes as in the Basic Oxygen Furnace (BOF or in the Electric Arc Furnace (EAF. Those jets improve heat, mass and momentum transfer in the liquid metal, mixing of chemical species enhancing and govern the formation of foaming slag. In this work experimental measurements were performed to determine the dimensions of the cavity formed at the liquid free surface caused by a gas jet impinging on it; also velocities vectors were measured in the zone affected by the gas jet. Cavities were measured from images from high speed camera and the vector maps were obtained with a Particle Image Velocimetry (PIV technique. Both velocities and cavities were determined as a function of the main process variables: gas flow rate, distance of the nozzle from the free surface and lance angle. Cavity dimensions were statistically processed treated as a function of the process variables and also as a function of the proper dimensionless numbers that govern these phenomena. It was found thatWeber and Froude numbers govern the cavity geometry. Liquid flow driven by the jet is mainly affected by the air flow rate, lance height and angle.El uso de chorros de gas (oxígeno es fundamental en diversos procesos de aceración, como el Horno Básico de Oxígeno (BOF, por sus siglas en inglés o en el Horno Eléctrico de Arco (EAF. Estos chorros mejoran la transferencia de calor, masa y cantidad de movimiento en el metal y el mezclado de especies y son muy importantes en la formación de escoria espumosa. En este trabajo, se realizaron mediciones experimentales de las dimensiones de la cavidad formada en la superficie líquida por la incidencia de un chorro, así como también se obtuvieron vectores de velocidad en la zona aledaña a dicha cavidad. Éstas, se midieron usando una cámara de alta velocidad, mientras que los mapas vectoriales se obtuvieron por la técnica PIV (Particle Image Velocimetry. Las

The Effect of Temperature and Air Velocity on Drying Kinetics of Pistachio Nuts during Roasting by using Hot Air Flow

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A Dini

2017-10-01

Full Text Available Introduction Pistachio nut is one of the most delicious and nutritious nuts in the world and it is being used as a saltedand roasted product or as an ingredient in snacks, ice cream, desserts, etc. The purpose of roasting is to promote flavour and texture changes in nuts that ultimately increase the overall palatability of the product.Roasting involves a number of physico-chemical changes, including heat exchange, chemical reactions and drying. Knowledge of desorption kinetics is essential to predict the behavior of the material during roasting process and to design roaster equipment.The main aim of this research was to evaluate suitable models for predicting moisture ratio, the effect of air temperature and velocity on the drying kinetics of pistachio nuts and obtain the effective diffusivity coefficient and activation energy in the drying process during the roasting of pistachio nuts. Materials and Methods Dried Ahmadaghaei pistachio nuts were supplied from Kashefan Kavir company (Doraj co. in Rafsanjan. Pistachio nuts were soaked in 17% salt solution for 8 minute and roasting was investigated at air temperatures of 120,130, 145, 160 and 170 °C and air velocities of 0.6, 0.88, 1.3, 1.72 and 2 ms-1. Five semi-theoretical and two empirical kinetic models were fitted to drying experimental data using nonlinear regression analysis techniques in the Curve Expert 2.2 computer program. Results and Discussion Tow-way ANOVA indicated that temperature and hot air velocity significantly affected the drying process during roasting of shelled pistachio nuts. The higher roasting temperatures and air velocities resulted in the higher drying rates. During first 10 min of roasting at constant air velocity of 1.3 ms-1, 64.5%, 70.3%, 77.1%, 83.5%, 89.7% of the moisture were removed at roasting air temperatures of 120 °C, 130 °C, 145 °C, 160 °C, 170 °C, respectively. The high regression coefficients (R2>0.996 and low reduced chi-square (χ2, mean relative

Measurement of the burning velocity of propane-air mixtures using soap bubbles

Energy Technology Data Exchange (ETDEWEB)

Sakai, Yukio

1988-12-20

By filling a soap bubble with propane-air mixture of spacified equivalence ratio and by igniting it at the center, the flame propagation velocity was measured applying multiplex exposure Schlieren method. And the flow velocity of the unburnt propane-air mixture was also measured by a hot-wire anemometer. From the differences of the above two velocities, the burning velocity was obtained. The values of the burning velocity agreed well with the highly accurate results of usual measurements. The maximum value of the burning velocity, which exists at an equivalence ratio of 1.1, was 50cm/s. This value agreed well with the theoretical calculation result on the on-dimensional flame by Warnatz. The burning velocity in the range of from 0.7 to 1.5 equivalence ratios decreases symmetrically with the maximum value at the center. The velocity decrease in the excessive concentration range of fuel is only a little and converges between 7 and 10 cm/s. To evade the influence of the flame-front instability, measurements were done from 2 to 5cm from the ignition center. Thus accurate values were obtained. 23 refs., 5 figs.

Effect of flow velocity on the process of air-steam condensation in a vertical tube condenser

Science.gov (United States)

Havlík, Jan; Dlouhý, Tomáš

2018-06-01

This article describes the influence of flow velocity on the condensation process in a vertical tube. For the case of condensation in a vertical tube condenser, both the pure steam condensation process and the air-steam mixture condensation process were theoretically and experimentally analyzed. The influence of steam flow velocity on the value of the heat transfer coefficient during the condensation process was evaluated. For the condensation of pure steam, the influence of flow velocity on the value of the heat transfer coefficient begins to be seen at higher speeds, conversely, this effect is negligible at low values of steam velocity. On the other hand, for the air-steam mixture condensation, the influence of flow velocity must always be taken into account. The flow velocity affects the water vapor diffusion process through non-condensing air. The presence of air significantly reduces the value of the heat transfer coefficient. This drop in the heat transfer coefficient is significant at low velocities; on the contrary, the decrease is relatively small at high values of the velocity.

PREDICTION OF GAS HOLD-UP IN A COMBINED LOOP AIR LIFT FLUIDIZED BED REACTOR USING NEWTONIAN AND NON-NEWTONIAN LIQUIDS

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Sivakumar Venkatachalam

2011-09-01

Full Text Available Many experiments have been conducted to study the hydrodynamic characteristics of column reactors and loop reactors. In this present work, a novel combined loop airlift fluidized bed reactor was developed to study the effect of superficial gas and liquid velocities, particle diameter, fluid properties on gas holdup by using Newtonian and non-Newtonian liquids. Compressed air was used as gas phase. Water, 5% n-butanol, various concentrations of glycerol (60 and 80% were used as Newtonian liquids, and different concentrations of carboxy methyl cellulose aqueous solutions (0.25, 0.6 and 1.0% were used as non-Newtonian liquids. Different sizes of spheres, Bearl saddles and Raschig rings were used as solid phases. From the experimental results, it was found that the increase in superficial gas velocity increases the gas holdup, but it decreases with increase in superficial liquid velocity and viscosity of liquids. Based on the experimental results a correlation was developed to predict the gas hold-up for Newtonian and non-Newtonian liquids for a wide range of operating conditions at a homogeneous flow regime where the superficial gas velocity is approximately less than 5 cm/s

Investigation on Effect of Air Velocity in Turbulent Non-Premixed Flames

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Namazian Zafar

2016-09-01

Full Text Available In this study, the turbulent non-premixed methane-air flame is simulated to determine the effect of air velocity on the length of flame, temperature distribution and mole fraction of species. The computational fluid dynamics (CFD technique is used to perform this simulation. To solve the turbulence flow, k-ε model is used. In contrast to the previous works, in this study, in each one of simulations the properties of materials are taken variable and then the results are compared. The results show that at a certain flow rate of fuel, by increasing the air velocity, similar to when the properties are constant, the width of the flame becomes thinner and the maximum temperature is higher; the penetration of oxygen into the fuel as well as fuel consumption is also increased. It is noteworthy that most of the pollutants produced are NOx, which are strongly temperature dependent. The amount of these pollutants rises when the temperature is increased. As a solution, decreasing the air velocity can decrease the amount of these pollutants. Finally, comparing the result of this study and the other work, which considers constant properties, shows that the variable properties assumption leads to obtaining more exact solution but the trends of both results are similar.

Numerical Simulation of Air Temperature and Velocity in a Naturally Ventilated Office

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S. Shodiya

2017-04-01

Full Text Available This paper presents a numerical simulation of air velocity and air temperature distribution in an office room of Computer Engineering Department of University of Maiduguri which is naturally ventilated. The office room under investigation with the dimension 5 m × 5 m × 4 m has a door in the East direction, and two windows, one in the East direction and the other in the South direction. For cost effectiveness, numerical solutions of steady-state airflow and heat transfer were done using a complete two-dimensional model. The results showed that the windows and the door could not undertake indoor heat load that can make the occupants to be thermally comfortable. In activity area where people sit and stand, the air velocity is moderate, this is about 0.98 m/s on the average. In addition, the temperature in this area is relatively high of about 302 K (29 °C on the average. Based on the American Society of Heating, Refrigeration and Air-Conditioning Engineers (ASHRAE standard for comfort environment in summer (air temperature: 293 – 299 K (20 – 26 °C; air velocity: 0.5 – 0.8 m/s, the natural ventilation for the office room cannot give a thermal comfort for the inhabitant of the room. However, a window, if installed opposite the door could improve the ventilation of the office.

Liquid velocity in upward and downward air-water flows

International Nuclear Information System (INIS)

Sun Xiaodong; Paranjape, Sidharth; Kim, Seungjin; Ozar, Basar; Ishii, Mamoru

2004-01-01

Local characteristics of the liquid phase in upward and downward air-water two-phase flows were experimentally investigated in a 50.8-mm inner-diameter round pipe. An integral laser Doppler anemometry (LDA) system was used to measure the axial liquid velocity and its fluctuations. No effect of the flow direction on the liquid velocity radial profile was observed in single-phase liquid benchmark experiments. Local multi-sensor conductivity probes were used to measure the radial profiles of the bubble velocity and the void fraction. The measurement results in the upward and downward two-phase flows are compared and discussed. The results in the downward flow demonstrated that the presence of the bubbles tended to flatten the liquid velocity radial profile, and the maximum liquid velocity could occur off the pipe centerline, in particular at relatively low flow rates. However, the maximum liquid velocity always occurred at the pipe center in the upward flow. Also, noticeable turbulence enhancement due to the bubbles in the two-phase flows was observed in the current experimental flow conditions. Furthermore, the distribution parameter and the void-weighted area-averaged drift velocity were obtained based on the definitions

Numerical calculation of air velocity and temperature in ice rinks

Energy Technology Data Exchange (ETDEWEB)

Bellache, O.; Galanis, N. [Sherbrooke Univ., PQ (Canada); Ouzzane, M.; Sunye, R. [Natural Resources Canada, Varennes, PQ (Canada). CANMET Energy Diversification Laboratory

2002-07-01

A computational fluid dynamic (CFD) model was developed to predict the energy consumption at an ice rink. Ice rinks in Canada consume approximately 3500 GWh of electricity annually and generate about 300,000 tons of gases contributing to the greenhouse effect. This newly developed model also considers ice quality and comfort conditions in the arena. The typical 2D configuration includes refrigeration loads as well as heat transfer coefficients between the air and the ice. The effects of heat losses through the ice rink envelope are also determined. A comparison of prediction results from 4 different formulations confirms that there are important differences in air velocities near the walls and in the temperature gradient near the ice. The turbulent mixed convection model gives the best estimate of the refrigeration load. It was determined that a good ventilation should circulate air throughout the building to avoid stagnant areas. Air velocities must be low near the stands where the temperature should be around 20 degrees C. Air temperature near the ice should be low to preserve ice quality and to reduce the refrigeration load. The complexity of this geometry has been taken into account in a numerical simulation of the hydrodynamic and thermal fields in the ice rink. 9 refs., 2 tabs., 5 figs.

Simultaneous velocity and pressure quantification using pressure-sensitive flow tracers in air

Science.gov (United States)

Zhang, Peng; Peterson, Sean; Porfiri, Maurizio

2017-11-01

Particle-based measurement techniques for assessing the velocity field of a fluid have advanced rapidly over the past two decades. Full-field pressure measurement techniques have remained elusive, however. In this work, we aim to demonstrate the possibility of direct simultaneous planar velocity and pressure measurement of a high speed aerodynamic flow by employing novel pressure-sensitive tracer particles for particle image velocimetry (PIV). Specifically, the velocity and pressure variations of an airflow through a converging-diverging channel are studied. Polystyrene microparticles embedded with a pressure-sensitive phosphorescent dye-platinum octaethylporphyrin (PtOEP)-are used as seeding particles. Due to the oxygen quenching effect, the emission lifetime of PtOEP is highly sensitive to the oxygen concentration, that is, the partial pressure of oxygen, in the air. Since the partial pressure of oxygen is linearly proportional to the air pressure, we can determine the air pressure through the phosphorescence emission lifetime of the dye. The velocity field is instead obtained using traditional PIV methods. The particles have a pressure resolution on the order of 1 kPa, which may be improved by optimizing the particle size and dye concentration to suit specific flow scenarios. This work was supported by the National Science Foundation under Grant Number CBET-1332204.

Live performance of male broilers subjected to constant or increasing air velocities at moderate temperatures with a high dew point.

Science.gov (United States)

Dozier, W A; Lott, B D; Branton, S L

2005-08-01

This study examined the effects of varying air velocities vs. a constant air velocity with a cyclic temperature curve of 25-30-25 degrees C and a dew point of 23 degrees C on broilers from 28 to 49 d of age. Four replicate trials were conducted. In each trial, 742 male broilers were randomly allocated to 6 floor pens or 2 air velocity tunnels, with each tunnel consisting of 4 pens. Bird density, feeder, and waterer space were similar across all pens (53 birds/ pen; 0.07 m2/bird). The treatments were control (still air), constant air velocity of 120 m/min, and increasing air velocity (90 m/min from 28 to 35 d, 120 m/min from 36 to 42 d, and 180 m/min from 43 to 49 d). Birds grown in a still air environment gained less weight, consumed less feed, and converted feed less efficiently between 28 and 49 d than birds subjected to moving air (constant or increasing). Growth responses between the air velocity treatments were similar from 28 to 35 and 36 to 42 d of age. Increasing air velocity to 180 m/min improved (P < or = 0.02) the growth rate of broilers from 43 to 49 d of age over birds receiving an air velocity of 120 m/min, but the incidence of mortality was not affected. These results provide evidence that increasing air velocity from 120 to 180 m/min is beneficial to broilers weighing 2.5 kg or greater when exposed to moderate temperatures.

Velocity and uniformity of air circulation in conventional kilns for sawn timber

Directory of Open Access Journals (Sweden)

Kolin Branko

2012-01-01

Full Text Available This paper presents the results of a research of velocity of air circulation in the conventional kiln drying of sawn timber and its influence on the uniformity of final moisture content. The data showed that the air velocity (between 0.8 - 1.2 m•s -1 is significantly lower than the one that is optimal for timber drying of coniferous species (3 - 4 m•s-1. This results in a reduction in the capacity of installations for drying, increased energy (thermal and electrical consumption and thereby increase in the cost of drying. The correlation between the speed of air circulation and the final MC of timber due to prolonged drying was not established. Recommendations that should eliminate the identified deficiencies are also given.

Influence of local air velocity from air conditioner evaluated by salivary and skin biomarkers

OpenAIRE

Yamaguchi, Masaki; Takahashi, Takayuki; Yoshino, Yuichiro; Sasaki, Makoto; Nishiyama, Hajime

2010-01-01

The purpose of this paper is to reveal both the psychosomatic and the physical effects of local air velocity from an air conditioner using biomarkers which can be collected noninvasively. Salivary α-amylase activity (SAA) and salivary cortisol were used as the indexes of psychosomatic effects. The total protein (TP) collected from stratum corneum was used as an index of the physical condition of dry skin. A continuous experiment over a 5 days period in summer was conducted using 8 healthy you...

Laminar burning velocities of acetone in air at room and elevated temperatures

NARCIS (Netherlands)

Nilsson, E.J.K.; Goey, de L.P.H.; Konnov, A.

2013-01-01

Laminar burning velocities of acetone + air mixtures at initial gas mixture temperatures of 298, 318, 338 and 358 K are reported. Non-stretched flames were stabilized on a perforated plate burner at 1 atm, and laminar burning velocities were determined using the heat flux method, at conditions where

Measurement and Numerical Simulation of Air Velocity in a Tunnel-Ventilated Broiler House

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Eliseo Bustamante

2015-02-01

Full Text Available A building needs to be designed for the whole period of its useful life according to its requirements. However, future climate predictions involve some uncertainty. Thus, several sustainable strategies of adaptation need to be incorporated after the initial design. In this sense, tunnel ventilation in broiler houses provides high air velocity values (2–3 m·s−1 at animal level to diminish their thermal stress and associated mortality. This ventilation system was experimentally incorporated into a Mediterranean climate. The aim was to resolve these thermal problems in hot seasons, as (traditional cross-mechanical ventilation does not provide enough air velocity values. Surprisingly, very little information on tunnel ventilation systems is available, especially in terms of air velocity. Using Computational Fluid Dynamics (CFD and a multi-sensor system, the average results are similar (at animal level: 1.59 ± 0.68 m·s−1 for CFD and 1.55 ± 0.66 m·s−1 for measurements. The ANOVA for validation concluded that the use of CFD or measurements is not significant (p-value = 0.1155. Nevertheless, some problems with air velocity distribution were found and need to be solved. To this end, CFD techniques can help by means of virtual designs and scenarios providing information for the whole indoor space.

Air velocity profiles near sleeve blockages in an unheated 7 x 7 rod bundle. [PWR

Energy Technology Data Exchange (ETDEWEB)

Creer, J. M.; Bates, J. M.

1979-04-01

Local air velocity measurements were obtained with a laser Doppler anemometer near flow blockages in an unheated 7 x 7 rod bundle. Sleeve blockages were positioned on the center nine rods to create an area reduction of 90% in the center four subchannels of the bundle. Experimental results indicated that severe flow disturbances occurred downstream from the blockage cluster but showed only minor flow disturbances upstream from the blockage. Flow reversals were detected downstream from the blockage and persisted for approximately five subchannel hydraulic diameters. The air velocity profiles were in excellent agreement with water velocity data previously obtained at essentially the same Reynolds number. Subchannel average velocity predictions obtained with the COBRA computer program were in good agreement with subchannel average velocities estimated using the measured local velocity data.

Local measurement of interfacial area, interfacial velocity and liquid turbulence in two-phase flow

International Nuclear Information System (INIS)

Hibiki, T.; Hogsett, S.; Ishii, M.

1998-01-01

Double sensor probe and hotfilm anemometry methods were developed for measuring local flow characteristics in bubbly flow. The formulation for the interfacial area concentration measurement was obtained by improving the formulation derived by Kataoka and Ishii. The assumptions used in the derivation of the equation were verified experimentally. The interfacial area concentration measured by the double sensor probe agreed well with one by the photographic method. The filter to validate the hotfilm anemometry for measuring the liquid velocity and turbulent intensity in bubbly flow was developed based on removing the signal due to the passing bubbles. The local void fraction, interfacial area concentration, interfacial velocity, Sauter mean diameter, liquid velocity, and turbulent intensity of vertical upward air-water flow in a round tube with inner diameter of 50.8 mm were measured by using these methods. A total of 54 data sets were acquired consisting of three superficial gas flow rates, 0.039, 0.067, and 0.147 m/s, and three superficial liquid flow rates, 0.60, 1.00, and 1.30 m/s. The measurements were performed at the three locations: L/D=2, 32, and 62. This data is expected to be used for the development of reliable constitutive relations which reflect the true transfer mechanisms in two-phase flow. (author)

Preferred Air Velocity and Local Cooling Effect of desk fans in warm environments

DEFF Research Database (Denmark)

Simone, Angela; Olesen, Bjarne W.

2013-01-01

to compensate for higher environmental temperatures at the expense of no or relatively low energy consumption. When using desk fans, local air movement is generated around the occupant and a certain cooling effect is perceived. The impact of the local air movement generated by different air flow patterns......Common experiences, standards, and laboratory studies show that increased air velocity helps to offset warm sensation due to high environmental temperatures. In warm climate regions the opening of windows and the use of desk or ceiling fans are the most common systems to generate increased airflows......, and the possibility to keep comfortable conditions for the occupants in warm environments were evaluated in studies with human subjects. In an office-like climatic chamber, the effect of higher air velocity was investigated at room temperatures between 26°C to 34°C and at constant absolute humidity of 12.2 g...

Optimization of the velocity of air providing dynamic containment at openings

International Nuclear Information System (INIS)

Laborde, J.C.; Berne, P.; Dupoux, N.

1992-01-01

The handling of toxic, radioactive or dangerous substances in industry of research laboratories necessitates the use of techniques for protecting the workers involved. The risks arise from these substances being airborne particles and from their transfer, essentially through turbulent diffusion. One way of limiting this risk is to employ the principle of dynamic containment, whereby a particular direction of air flow is imposed at inlets and outlets in order to prevent the back flow of the pollutant to areas where it may be breathed by the operators. The air velocity normally used to prevent back flow of pollutant is 0.5 m.s. The 'Service d'Etudes et de Recherches en Aerocontamination et en Confinement' (SERAC) has begun an evaluation of the effect of a reduction in air inlet velocity on the risk of pollutant back diffusion. This should lead to energy savings through the use of a minimum air flow rate concomitant with appropriate protection. The paper gives the results obtained with openings of different geometries and shapes. It is also proposed a simulation of this phenomenon using a calculation code of air flow in a ventilated room (the TRIO code), so that the results may be compared with the experimental data. (author). 5 refs., 10 figs., 1 tab

Temperature Control of Heating Zone for Drying Process: Effect of Air Velocity Change

Directory of Open Access Journals (Sweden)

Wutthithanyawat Chananchai

2016-01-01

Full Text Available This paper proposes a temperature control technique to adjust air temperature in a heating zone for drying process. The controller design is achieved by using an internal model control (IMC approach. When the IMC controller parameters were designed by calculating from an actual process transfer function estimated through an open-loop step response with input step change from 50% to 60% at a reference condition at air velocity of 1.20 m/s, the performance of temperature controller was experimentally tested by varying an air velocity between 1.32 m/s and 1.57 m/s, respectively. The experimental results showed that IMC controller had a high competency for controlling the drying temperature.

Critique of the use of deposition velocity in modeling indoor air quality

International Nuclear Information System (INIS)

Nazaroff, W.W.; Weschler, C.J.

1993-01-01

Among the potential fates of indoor air pollutants are a variety of physical and chemical interactions with indoor surfaces. In deterministic mathematical models of indoor air quality, these interactions are usually represented as a first-order loss process, with the loss rate coefficient given as the product of the surface-to-volume ratio of the room times a deposition velocity. In this paper, the validity of this representation of surface-loss mechanisms is critically evaluated. From a theoretical perspective, the idea of a deposition velocity is consistent with the following representation of an indoor air environment. Pollutants are well-mixed throughout a core region which is separated from room surfaces by boundary layers. Pollutants migrate through the boundary layers by a combination of diffusion (random motion resulting from collisions with surrounding gas molecules), advection (transport by net motion of the fluid), and, in some cases, other transport mechanisms. The rate of pollutant loss to a surface is governed by a combination of the rate of transport through the boundary layer and the rate of reaction at the surface. The deposition velocity expresses the pollutant flux density (mass or moles deposited per area per time) to the surface divided by the pollutant concentration in the core region. This concept has substantial value to the extent that the flux density is proportional to core concentration. Published results from experimental and modeling studies of fine particles, radon decay products, ozone, and nitrogen oxides are used as illustrations of both the strengths and weaknesses of deposition velocity as a parameter to indicate the rate of indoor air pollutant loss on surfaces. 66 refs., 5 tabs

Axial dispersion, holdup and slip velocity of dispersed phase in a pulsed sieve plate extraction column by radiotracer residence time distribution analysis.

Science.gov (United States)

Din, Ghiyas Ud; Chughtai, Imran Rafiq; Inayat, Mansoor Hameed; Khan, Iqbal Hussain

2008-12-01

Axial dispersion, holdup and slip velocity of dispersed phase have been investigated for a range of dispersed and continuous phase superficial velocities in a pulsed sieve plate extraction column using radiotracer residence time distribution (RTD) analysis. Axial dispersion model (ADM) was used to simulate the hydrodynamics of the system. It has been observed that increase in dispersed phase superficial velocity results in a decrease in its axial dispersion and increase in its slip velocity while its holdup increases till a maximum asymptotic value is achieved. An increase in superficial velocity of continuous phase increases the axial dispersion and holdup of dispersed phase until a maximum value is obtained, while slip velocity of dispersed phase is found to decrease in the beginning and then it increases with increase in superficial velocity of continuous phase.

Velocity Distribution in a Room Ventilated by Displacement Ventilation and Wall-Mounted Air Terminal Devices

DEFF Research Database (Denmark)

Nielsen, Peter Vilhelm

2000-01-01

The article describes experiments with wall-mounted air terminal devices. The airflow from an air terminal device influences the occupants' thermal comfort and, therefore, it is important to develop an expression for this flow in the occupied zone. The velocity at the floor is influenced...... by the flow rate to the room, the temperature difference and the type of diffuser. The flow is stratified at Archimedes numbers larger than four. The article gives expressions for the velocity distribution close to the floor. It is shown that openings between obstacles placed directly on the floor generate...... a flow similar to the air movement in front of a diffuser, and expressions for the velocity distribution in that situation are also given in the article....

Noninvasive evaluation of the chronic influence of local air velocity from an air conditioner using salivary cortisol and skin caspase-14 as biomarkers of psychosomatic and environmental stress.

Science.gov (United States)

Yamaguchi, M; Nishimiya, H

2012-01-01

To demonstrate the possibility of evaluating the chronic influence of local air velocity from an air conditioner using noninvasive biomarkers. Over a consecutive 5-day period, 16 healthy young male adults were exposed to air flow from a whole ceiling-type air conditioner (low local air velocity) and from a commercial concentrated exhaust air conditioner (high local air velocity). Salivary cortisol was used as an index of the psychological effects and caspase-14, collected from the stratum corneum, was used as a marker of environmental stress on the skin. Local air velocity generated from the whole ceiling-type air conditioner where the subject's head was positioned was one-seventh that of the exhaust air conditioner. After exposure to the exhaust air conditioner for 5 days, salivary cortisol decreased significantly from morning to evening and skin caspase-14 gradually increased during the day. A significant increase in hydration index from the morning to the evening was found with the whole ceiling-type air conditioner. The effects of chronic exposure to air movement generated by an air conditioner may be quantified by measurement of salivary cortisol and skin caspase-14.

Influences of the Air in Metal Powder High Velocity Compaction

Directory of Open Access Journals (Sweden)

Liu Jun

2017-01-01

Full Text Available During the process of metal powder high velocity impact compaction, the air is compressed sharply and portion remains in the compacts. In order to study the Influences, a discrete density volleyball accumulation model for aluminium powder was established with the use of ABAQUS. Study found that the powder porosity air obstruct the pressing process because remaining air reduced strength and density of the compacts in the current high-speed pressing (V≤100m/s. When speed further increased (V≥100m/s, the temperature of the air increased sharply, and was even much higher than the melting point of the material. When aluminium powder was compressed at a speed of 200m/s, temperatures of air could reach 2033 K, far higher than the melting point of 877 K. Increased density of powders was a result of local softening and even melt adhesive while air between particles with high temperature and pressure flowed past.

Validation of a CFD model by using 3D sonic anemometers to analyse the air velocity generated by an air-assisted sprayer equipped with two axial fans.

Science.gov (United States)

García-Ramos, F Javier; Malón, Hugo; Aguirre, A Javier; Boné, Antonio; Puyuelo, Javier; Vidal, Mariano

2015-01-22

A computational fluid dynamics (CFD) model of the air flow generated by an air-assisted sprayer equipped with two axial fans was developed and validated by practical experiments in the laboratory. The CFD model was developed by considering the total air flow supplied by the sprayer fan to be the main parameter, rather than the outlet air velocity. The model was developed for three air flows corresponding to three fan blade settings and assuming that the sprayer is stationary. Actual measurements of the air velocity near the sprayer were taken using 3D sonic anemometers. The workspace sprayer was divided into three sections, and the air velocity was measured in each section on both sides of the machine at a horizontal distance of 1.5, 2.5, and 3.5 m from the machine, and at heights of 1, 2, 3, and 4 m above the ground The coefficient of determination (R2) between the simulated and measured values was 0.859, which demonstrates a good correlation between the simulated and measured data. Considering the overall data, the air velocity values produced by the CFD model were not significantly different from the measured values.

Study on laminar burning velocity of syngas-air premixed flames in various mixing conditions

International Nuclear Information System (INIS)

Lee, Kee Man; Jeong, Byeong Gyu; Lee, Seung Ro

2015-01-01

The laminar burning velocity of syngas-air premixed flames was measured with various equivalence ratios from 0.5 to 5.0 and a mole fraction of H 2 from 0.05 to 0.75. The laminar burning velocity was experimentally determined using a Bunsen flame according to the cone angle and surface area methods. A premixed code with a USC-II detailed reaction mechanism was used for the numerical calculations to predict the laminar burning velocity and to examine the relationship between the burning velocity enhancement and the hydrogen-related reactions. The results indicate that an appropriate method for the measurement of laminar burning velocity is necessary in the H 2 /CO/air syngas premixed flame. In addition, the burning velocity linearly increased with the increase of the H 2 mole fraction in the syngas mixture, although the burning velocity of H 2 was 10 times larger than that of CO. This result is attributed to the rapid production of H-radicals at the early stage of combustion. Furthermore, the predicted mole fractions of H and OH radicals increased with the increase of H 2 mole fraction for a lean syngas mixture. However, the mole fraction of OH radicals, an indicator of heat release rate, decreased for rich syngas mixture, resulting in a reduction of the laminar burning velocity, even with an increase of the H 2 mole fraction.

Modeling skin temperature to assess the effect of air velocity to mitigate heat stress among growing pigs

DEFF Research Database (Denmark)

Bjerg, Bjarne; Pedersen, Poul; Morsing, Svend

2017-01-01

It is generally accepted that increased air velocity can help to mitigate heat stress in livestock housing, however, it is not fully clear how much it helps and significant uncertainties exists when the air temperature approaches the animal body temperature. This study aims to develop a skin...... temperature model to generated data for determining the potential effect of air velocity to mitigate heat stress among growing pigs housed in warm environment. The model calculates the skin temperature as function of body temperature, air temperature and the resistances for heat transfer from the body...

New sensor for measurement of low air flow velocity. Phase I final report

International Nuclear Information System (INIS)

Hashemian, H.M.; Hashemian, M.; Riggsbee, E.T.

1995-08-01

The project described here is the Phase I feasibility study of a two-phase program to integrate existing technologies to provide a system for determining air flow velocity and direction in radiation work areas. Basically, a low air flow sensor referred to as a thermocouple flow sensor has been developed. The sensor uses a thermocouple as its sensing element. The response time of the thermocouple is measured using an existing in-situ method called the Loop Current Step Response (LCSR) test. The response time results are then converted to a flow signal using a response time-versus-flow correlation. The Phase I effort has shown that a strong correlation exists between the response time of small diameter thermocouples and the ambient flow rate. As such, it has been demonstrated that thermocouple flow sensors can be used successfully to measure low air flow rates that can not be measured with conventional flow sensors. While the thermocouple flow sensor developed in this project was very successful in determining air flow velocity, determining air flow direction was beyond the scope of the Phase I project. Nevertheless, work was performed during Phase I to determine how the new flow sensor can be used to determine the direction, as well as the velocity, of ambient air movements. Basically, it is necessary to use either multiple flow sensors or move a single sensor in the monitoring area and make flow measurements at various locations sweeping the area from top to bottom and from left to right. The results can then be used with empirical or physical models, or in terms of directional vectors to estimate air flow patterns. The measurements can be made continuously or periodically to update the flow patterns as they change when people and objects are moved in the monitoring area. The potential for using multiple thermocouple flow sensors for determining air flow patterns will be examined in Phase II

Study on laminar burning velocity of syngas-air premixed flames in various mixing conditions

Energy Technology Data Exchange (ETDEWEB)

Lee, Kee Man; Jeong, Byeong Gyu [Sunchon National University, Suncheon (Korea, Republic of); Lee, Seung Ro [Chonbuk National University, Jeonju (Korea, Republic of)

2015-07-15

The laminar burning velocity of syngas-air premixed flames was measured with various equivalence ratios from 0.5 to 5.0 and a mole fraction of H{sub 2} from 0.05 to 0.75. The laminar burning velocity was experimentally determined using a Bunsen flame according to the cone angle and surface area methods. A premixed code with a USC-II detailed reaction mechanism was used for the numerical calculations to predict the laminar burning velocity and to examine the relationship between the burning velocity enhancement and the hydrogen-related reactions. The results indicate that an appropriate method for the measurement of laminar burning velocity is necessary in the H{sub 2}/CO/air syngas premixed flame. In addition, the burning velocity linearly increased with the increase of the H{sub 2} mole fraction in the syngas mixture, although the burning velocity of H{sub 2} was 10 times larger than that of CO. This result is attributed to the rapid production of H-radicals at the early stage of combustion. Furthermore, the predicted mole fractions of H and OH radicals increased with the increase of H{sub 2} mole fraction for a lean syngas mixture. However, the mole fraction of OH radicals, an indicator of heat release rate, decreased for rich syngas mixture, resulting in a reduction of the laminar burning velocity, even with an increase of the H{sub 2} mole fraction.

Design Strategy for CO2 Adsorption from Ambient Air Using a Supported Amine Based Sorbent in a Fixed Bed Reactor

NARCIS (Netherlands)

Yu, Qian; Brilman, D. W.F.

In this work, a fixed bed reactor is evaluated for CO2 capture from ambient air using an amine based ion exchange resin. Using adsorption experiments, the effect of superficial velocity and bed length on process economics is investigated. It is shown that the optimal conditions are found at an

Determination of the most economical drying schedule and air velocity in softwood drying

Energy Technology Data Exchange (ETDEWEB)

Salin, J.G.

2001-12-01

Simulation models for conventional softwood drying have been available and have also been used by kiln operators for many years. For instance models for Scots pine and Norway spruce, dried at temperatures below about 80 deg C, are in use in Sweden, Finland and Norway. These models predict drying rates as a function of climate (schedule) and air velocity. The models thus give a direct basis for calculation of instantaneous energy demand for moisture evaporation and ventilation. There is further a direct relationship between the air velocity in the space between the board layers in the kiln stack and the electrical power demand by the circulation fans. Finally, the smaller energy consumption associated with heat losses through kiln walls and the accumulated heat in timber etc. can be estimated with sufficient accuracy. Instantaneous energy costs can thus be calculated for each part of a drying schedule. Capital costs associated with kiln investment and maintenance, personnel, insurance etc can be accounted for as an hourly cost, which is basically independent of whether timber is dried fast or slowly. A slow drying process thus accumulates more capital costs per m 3 timber. In this way it is possible to calculate the total instantaneous drying cost (Euro/m{sup 3}/h or Euro/m3/MC%) and the overall total cost (Euro or Euro/m{sup 3}). Some results obtained with a simulation model equipped with such a cost calculation are presented in the paper. A rapidly increasing drying cost is seen when the final MC is lowered. By minimising the instantaneous cost, an optimal drying schedule can be determined for a given fixed air velocity. Finally an optimal air velocity - constant or varying - can be found in the same way.

Measurements of the laminar burning velocity of hydrogen-air premixed flames

Energy Technology Data Exchange (ETDEWEB)

Pareja, Jhon; Burbano, Hugo J. [Science and Technology of Gases and Rational Use of Energy Group, Faculty of Engineering, University of Antioquia, Calle 67 N 53, 108 Bloque 20, 447 Medellin (Colombia); Ogami, Yasuhiro [Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan)

2010-02-15

Experimental and numerical studies on laminar burning velocities of hydrogen-air mixtures were performed at standard pressure and room temperature varying the equivalence ratio from 0.8 to 3.0. The flames were generated using a contoured slot-type nozzle burner (4 mm x 10 mm). Measurements of laminar burning velocity were conducted using particle tracking velocimetry (PTV) combined with Schlieren photography. This technique provides the information of instantaneous local burning velocities in the whole region of the flame front, and laminar burning velocities were determined using the mean value of local burning velocities in the region of non-stretch. Additionally, average laminar burning velocities were determined using the angle method and compared with the data obtained with the PTV method. Numerical calculations were also conducted using detailed reaction mechanisms and transport properties. The experimental results from the PTV method are in good agreement with the numerical results at every equivalence ratio of the range of study. Differences between the results obtained with the angle method and those with the PTV method are reasonably small when the effects of flame stretch and curvature are reduced by using a contoured slot-type nozzle. (author)

Fluid dynamics of air in a packed bed: velocity profiles and the continuum model assumption

Directory of Open Access Journals (Sweden)

NEGRINI A. L.

1999-01-01

Full Text Available Air flow through packed beds was analyzed experimentally under conditions ranging from those that reinforce the effect of the wall on the void fraction to those that minimize it. The packing was spherical particles, with a tube-to-particle diameter ratio (D/dp between 3 and 60. Air flow rates were maintained between 1.3 and 4.44 m3/min, and gas velocity was measured with a Pitot tube positioned above the bed exit. Measurements were made at various radial and angular coordinate values, allowing the distribution of air flow across the bed to be described in detail. Comparison of the experimentally observed radial profiles with those derived from published equations revealed that at high D/dp ratios the measured and calculated velocity profiles behaved similarly. At low ratios, oscillations in the velocity profiles agreed with those in the voidage profiles, signifying that treating the porous medium as a continuum medium is questionable in these cases.

Statistics of surface divergence and their relation to air-water gas transfer velocity

Science.gov (United States)

Asher, William E.; Liang, Hanzhuang; Zappa, Christopher J.; Loewen, Mark R.; Mukto, Moniz A.; Litchendorf, Trina M.; Jessup, Andrew T.

2012-05-01

Air-sea gas fluxes are generally defined in terms of the air/water concentration difference of the gas and the gas transfer velocity,kL. Because it is difficult to measure kLin the ocean, it is often parameterized using more easily measured physical properties. Surface divergence theory suggests that infrared (IR) images of the water surface, which contain information concerning the movement of water very near the air-water interface, might be used to estimatekL. Therefore, a series of experiments testing whether IR imagery could provide a convenient means for estimating the surface divergence applicable to air-sea exchange were conducted in a synthetic jet array tank embedded in a wind tunnel. Gas transfer velocities were measured as a function of wind stress and mechanically generated turbulence; laser-induced fluorescence was used to measure the concentration of carbon dioxide in the top 300 μm of the water surface; IR imagery was used to measure the spatial and temporal distribution of the aqueous skin temperature; and particle image velocimetry was used to measure turbulence at a depth of 1 cm below the air-water interface. It is shown that an estimate of the surface divergence for both wind-shear driven turbulence and mechanically generated turbulence can be derived from the surface skin temperature. The estimates derived from the IR images are compared to velocity field divergences measured by the PIV and to independent estimates of the divergence made using the laser-induced fluorescence data. Divergence is shown to scale withkLvalues measured using gaseous tracers as predicted by conceptual models for both wind-driven and mechanically generated turbulence.

Image processing analysis on the air-water slug two-phase flow in a horizontal pipe

Science.gov (United States)

Dinaryanto, Okto; Widyatama, Arif; Majid, Akmal Irfan; Deendarlianto, Indarto

2016-06-01

Slug flow is a part of intermittent flow which is avoided in industrial application because of its irregularity and high pressure fluctuation. Those characteristics cause some problems such as internal corrosion and the damage of the pipeline construction. In order to understand the slug characteristics, some of the measurement techniques can be applied such as wire-mesh sensors, CECM, and high speed camera. The present study was aimed to determine slug characteristics by using image processing techniques. Experiment has been carried out in 26 mm i.d. acrylic horizontal pipe with 9 m long. Air-water flow was recorded 5 m from the air-water mixer using high speed video camera. Each of image sequence was processed using MATLAB. There are some steps including image complement, background subtraction, and image filtering that used in this algorithm to produce binary images. Special treatments also were applied to reduce the disturbance effect of dispersed bubble around the bubble. Furthermore, binary images were used to describe bubble contour and calculate slug parameter such as gas slug length, gas slug velocity, and slug frequency. As a result the effect of superficial gas velocity and superficial liquid velocity on the fundamental parameters can be understood. After comparing the results to the previous experimental results, the image processing techniques is a useful and potential technique to explain the slug characteristics.

Effect of low air velocities on thermal homeostasis and comfort during exercise at space station operational temperature and humidity

Science.gov (United States)

Beumer, Ronald J.

1989-01-01

The effectiveness of different low air velocities in maintaining thermal comfort and homeostasis during exercise at space station operational temperature and humidity was investigated. Five male subjects exercised on a treadmill for successive ten minute periods at 60, 71, and 83 percent of maximum oxygen consumption at each of four air velocities, 30, 50, 80, and 120 ft/min, at 22 C and 62 percent relative humidity. No consistent trends or statistically significant differences between air velocities were found in body weight loss, sweat accumulation, or changes in rectal, skin, and body temperatures. Occurrence of the smallest body weight loss at 120 ft/min, the largest sweat accumulation at 30 ft/min, and the smallest rise in rectal temperature and the greatest drop in skin temperature at 120 ft/min all suggested more efficient evaporative cooling at the highest velocity. Heat storage at all velocities was evidenced by increased rectal and body temperatures; skin temperatures declined or increased only slightly. Body and rectal temperature increases corresponded with increased perception of warmth and slight thermal discomfort as exercise progressed. At all air velocities, mean thermal perception never exceeded warm and mean discomfort, greatest at 30 ft/min, was categorized at worst as uncomfortable; sensation of thermal neutrality and comfort returned rapidly after cessation of exercise. Suggestions for further elucidation of the effects of low air velocities on thermal comfort and homeostasis include larger numbers of subjects, more extensive skin temperature measurements and more rigorous analysis of the data from this study.

Measuring OutdoorAir Intake Rates Using Electronic Velocity Sensors at Louvers and Downstream of Airflow Straighteners

Energy Technology Data Exchange (ETDEWEB)

Fisk, William; Sullivan, Douglas; Cohen, Sebastian; Han, Hwataik

2008-10-01

Practical and accurate technologies are needed for continuously measuring and controlling outdoor air (OA) intake rates in commercial building heating, ventilating, and air conditioning (HVAC) systems. This project evaluated two new measurement approaches. Laboratory experiments determined that OA flow rates were measurable with errors generally less than 10percent using electronic air velocity probes installed between OA intake louver blades or at the outlet face of louvers. High accuracy was maintained with OA flow rates as low as 15percent of the maximum for the louvers. Thus, with this measurement approach HVAC systems do not need separate OA intakes for minimum OA supply. System calibration parameters are required for each unique combination of louver type and velocity sensor location but calibrations are not necessary for each system installation. The research also determined that the accuracy of measuring OA flow rates with velocity probes located in the duct downstream of the intake louver was not improved by installing honeycomb airflow straighteners upstream of the probes. Errors varied with type of upstream louver, were as high as 100percent, and were often greater than 25percent. In conclusion, use of electronic air velocity probes between the blades of OA intake louvers or at the outlet face of louvers is a highly promising means of accurately measuring rates of OA flow into HVAC systems. The use of electronic velocity probes downstream of airflow straighteners is less promising, at least with the relatively small OA HVAC inlet systems employed in this research.

Influence of increased velocity on the statistical discharge characteristics of He and air barrier discharges

International Nuclear Information System (INIS)

Reichen, P; Sonnenfeld, A; Rohr, Rudolf Ph von

2010-01-01

A detailed study of a description method for microdischarges based on the statistical analysis of single discharge bursts is presented and applied for small electrode arrays. As such, the electrical properties derived from the collective behaviour of the current bursts for microdischarges in helium and synthetic air for different pressure levels and variable voltage gradients are elaborately discussed. Motivated by the possible prolongation of the displacement distance of active species and thus the improved development of an atmospheric afterglow in a low frequency discharge, the interaction between high-speed gas flows and microdischarges in small ducts has been approached presenting first results. Intentionally, gases with different discharge mechanisms known as streamer (synthetic air) and Townsend (helium) have been considered. Similar velocity dependences of the discharge behaviour could be observed in both gases. For helium, subsonic channel velocity is sufficient to distinctively alter the discharge characteristics whereas transonic flow is needed to alter those of synthetic air. Subsequently, a simple model is proposed to explain these findings for elevated velocities in a dielectric setup.

Interfacial area, velocity and void fraction in two-phase slug flow

International Nuclear Information System (INIS)

Kojasoy, G.; Riznic, J.R.

1997-01-01

The internal flow structure of air-water plug/slug flow in a 50.3 mm dia transparent pipeline has been experimentally investigated by using a four-sensor resistivity probe. Liquid and gas volumetric superficial velocities ranged from 0.55 to 2.20 m/s and 0.27 to 2.20 m/s, respectively, and area-averaged void fractions ranged from about 10 to 70%. The local distributions of void fractions, interfacial area concentration and interface velocity were measured. Contributions from small spherical bubbles and large elongated slug bubbles toward the total void fraction and interfacial area concentration were differentiated. It was observed that the small bubble void contribution to the overall void fraction was small indicating that the large slug bubble void fraction was a dominant factor in determining the total void fraction. However, the small bubble interfacial area contribution was significant in the lower and upper portions of the pipe cross sections

Laminar burning velocities of near-flammability-limit H2-air-steam mixtures

International Nuclear Information System (INIS)

Loesel Sitar, J.V.; Chan, C.K.; Torchia, F.; Guerrero, A.

1995-01-01

Laminar burning velocities of lean H 2 -air-steam mixtures near the flammability limit were measured by using the pressure-time history of an expanding flame kernel. Although flames in these mixtures are inherently unstable, this difficulty was avoided by using the early pressure rise of the burn. A comparison of results from that method with burning velocities determined from schlieren photographs of the expanding flame kernel gave good agreement. Despite the difficulties, it is believed that the pressure trace method gives results that are useful in modelling reactor accident scenarios. 8 refs., 4 figs

Performance of a Compression-ignition Engine with a Precombustion Chamber Having High-Velocity Air Flow

Science.gov (United States)

Spanogle, J A; Moore, C S

1931-01-01

Presented here are the results of performance tests made with a single-cylinder, four stroke cycle, compression-ignition engine. These tests were made on a precombustion chamber type of cylinder head designed to have air velocity and tangential air flow in both the chamber and cylinder. The performance was investigated for variable load and engine speed, type of fuel spray, valve opening pressure, injection period and, for the spherical chamber, position of the injection spray relative to the air flow. The pressure variations between the pear-shaped precombustion chamber and the cylinder for motoring and full load conditions were determined with a Farnboro electric indicator. The combustion chamber designs tested gave good mixing of a single compact fuel spray with the air, but did not control the ensuing combustion sufficiently. Relative to each other, the velocity of air flow was too high, the spray dispersion by injection too great, and the metering effect of the cylinder head passage insufficient. The correct relation of these factors is of the utmost importance for engine performance.

Cleansing technique using high-velocity steam-air micromist jet spray.

Science.gov (United States)

Fukuda, Koichi; Ishihara, Masayuki; Murakami, Kaoru; Nakamura, Shingo; Sato, Yoko; Kuwabara, Masahiro; Fujita, Masanori; Kiyosawa, Tomoharu; Yokoe, Hidetaka

2017-10-01

Application of a high-velocity steam-air micromist jet spray (HVS-AMJS; micromist average diameter: 2.4 μm) for cleansing the skin is proposed. Low-pressure steam is mixed with compressed air (pH 6.5) in a nozzle, and then sprayed at a pressure of ≦0.25 MPa and a velocity of ≧0.34 m/s on the skin or surface of material located approximately 5-10 cm from the nozzle. The temperature on the sprayed surface and water flow rate could be controlled between 42 °C and 46 °C and at approximately 50 mL/min, respectively. Compared with ultrasonic cleansing with tap water and rubbing with only tap water, the HVS-AMJS successfully removed fluorescent lotion covering pieces of wood and significantly reduced both the number of coliforms and the total viable counts on pieces of wood and gauze. Furthermore, the HVS-AMJS effectively removed oily ink from the skin of hairless rats, and temporarily elevated the skin temperature and blood flow, indicating massage effects. The striking characteristics of this cleansing technique using HVS-AMJS are not only its ability to remove microbes and residue without using any chemicals or detergents but also its massage effects.

Gasification Performance of a Top-Lit Updraft Cook Stove

Directory of Open Access Journals (Sweden)

Yogesh Mehta

2017-10-01

Full Text Available This paper reports on an experimental study of a top-lit updraft cook stove with a focus on gasification. The reactor is operated with primary air only. The performance is studied for a variation in the primary airflow, as well as reactor geometry. Temperature in the reactor, air flow rate, fuel consumption rate, and producer gas composition were measured. From the measurements the superficial velocity, pyrolysis front velocity, peak bed temperature, air fuel ratio, heating value of the producer gas, and gasification rate were calculated. The results show that the producer gas energy content was maximized at a superficial velocity of 9 cm/s. The percent char remaining at the end of gasification decreased with increasing combustion chamber diameter. For a fixed superficial velocity, the gasification rate and producer gas energy content were found to scale linearly with diameter. The energy content of the producer gas was maximized at an air fuel (AF ratio of 1.8 regardless of the diameter.

Effect of airstream velocity on mean drop diameters of water sprays produced by pressure and air atomizing nozzles

Science.gov (United States)

Ingebo, R. D.

1977-01-01

A scanning radiometer was used to determine the effect of airstream velocity on the mean drop diameter of water sprays produced by pressure atomizing and air atomizing fuel nozzles used in previous combustion studies. Increasing airstream velocity from 23 to 53.4 meters per second reduced the Sauter mean diameter by approximately 50 percent with both types of fuel nozzles. The use of a sonic cup attached to the tip of an air assist nozzle reduced the Sauter mean diameter by approximately 40 percent. Test conditions included airstream velocities of 23 to 53.4 meters per second at 293 K and atmospheric pressure.

Calculation and measurement of a neutral air flow velocity impacting a high voltage capacitor with asymmetrical electrodes

Directory of Open Access Journals (Sweden)

M. Malík

2014-01-01

Full Text Available This paper deals with the effects surrounding phenomenon of a mechanical force generated on a high voltage asymmetrical capacitor (the so called Biefeld-Brown effect. A method to measure this force is described and a formula to calculate its value is also given. Based on this the authors derive a formula characterising the neutral air flow velocity impacting an asymmetrical capacitor connected to high voltage. This air flow under normal circumstances lessens the generated force. In the following part this velocity is measured using Particle Image Velocimetry measuring technique and the results of the theoretically calculated velocity and the experimentally measured value are compared. The authors found a good agreement between the results of both approaches.

Superficial evolution and compacting aptitude of uranium dioxide powders

International Nuclear Information System (INIS)

Danroc, J.

1982-04-01

Long term storage of UO 2 powder improves slightly shaping and solidity of compacted powder. The aim of this work is the study of material evolution and the increase of this evolution rate for application to industrial fabrication. Aging in wet air at different temperatures is examined. Evolution of texture and superficial composition is followed. Below 80 0 C UO 3 , 2H 2 O is formed at crystal surface and thermal decomposition gives different hydrates. Kinetics of the transformation is studied. Oxidohydratation in liquid phase is rapid with hydrogen peroxide. The aged or treated material is compacted and mechanical behaviour is examined. Improvement is explained by inter-layer water molecule of the superficial hydrate giving lubricant and pseudo-plastic properties [fr

Carbon isotope evidence for the latitudinal distribution and wind speed dependence of the air-sea gas transfer velocity

International Nuclear Information System (INIS)

Krakauer, Nir Y.

2006-01-01

The air-sea gas transfer velocity is an important determinant of the exchange of gases, including CO 2 , between the atmosphere and ocean, but the magnitude of the transfer velocity and what factors control it remains poorly known. Here, we use oceanic and atmospheric observations of 14 C and 13 C to constrain the global mean gas transfer velocity as well as the exponent of its wind speed dependence, utilizing the distinct signatures left by the air-sea exchange of 14 CO 2 and 13 CO 2 . While the atmosphere and ocean inventories of 14 CO 2 and 13 CO 2 constrain the mean gas transfer velocity, the latitudinal pattern in the atmospheric and oceanic 14 C and 13 C distributions contain information about the wind speed dependence. We computed the uptake of bomb 14 C by the ocean for different transfer velocity patterns using pulse response functions from an ocean general circulation model, and evaluated the match between the predicted bomb 14 C concentrations and observationally based estimates for the 1970s-1990s. Using a wind speed climatology based on satellite measurements, we solved either for the best-fit global relationship between gas exchange and mean wind speed or for the mean gas transfer velocity over each of 11 ocean regions. We also compared the predicted consequences of different gas exchange relationships on the rate of change and interhemisphere gradient of 14 C in atmospheric CO 2 with tree-ring and atmospheric measurements. Our results suggest that globally, the dependence of the air-sea gas transfer velocity on wind speed is close to linear, with an exponent of 0.5 ± 0.4, and that the global mean gas transfer velocity at a Schmidt number of 660 is 20 ± 3 cm/hr, similar to the results of previous analyses. We find that the air-sea flux of 13 C estimated from atmosphere and ocean observations also suggests a lower than quadratic dependence of gas exchange on wind speed

Using eddy covariance to measure the dependence of air-sea CO2 exchange rate on friction velocity

Science.gov (United States)

Landwehr, Sebastian; Miller, Scott D.; Smith, Murray J.; Bell, Thomas G.; Saltzman, Eric S.; Ward, Brian

2018-03-01

Parameterisation of the air-sea gas transfer velocity of CO2 and other trace gases under open-ocean conditions has been a focus of air-sea interaction research and is required for accurately determining ocean carbon uptake. Ships are the most widely used platform for air-sea flux measurements but the quality of the data can be compromised by airflow distortion and sensor cross-sensitivity effects. Recent improvements in the understanding of these effects have led to enhanced corrections to the shipboard eddy covariance (EC) measurements.Here, we present a revised analysis of eddy covariance measurements of air-sea CO2 and momentum fluxes from the Southern Ocean Surface Ocean Aerosol Production (SOAP) study. We show that it is possible to significantly reduce the scatter in the EC data and achieve consistency between measurements taken on station and with the ship underway. The gas transfer velocities from the EC measurements correlate better with the EC friction velocity (u*) than with mean wind speeds derived from shipboard measurements corrected with an airflow distortion model. For the observed range of wind speeds (u10 N = 3-23 m s-1), the transfer velocities can be parameterised with a linear fit to u*. The SOAP data are compared to previous gas transfer parameterisations using u10 N computed from the EC friction velocity with the drag coefficient from the Coupled Ocean-Atmosphere Response Experiment (COARE) model version 3.5. The SOAP results are consistent with previous gas transfer studies, but at high wind speeds they do not support the sharp increase in gas transfer associated with bubble-mediated transfer predicted by physically based models.

Influence of forced air volume on water evaporation during sewage sludge bio-drying.

Science.gov (United States)

Cai, Lu; Chen, Tong-Bin; Gao, Ding; Zheng, Guo-Di; Liu, Hong-Tao; Pan, Tian-Hao

2013-09-01

Mechanical aeration is critical to sewage sludge bio-drying, and the actual water loss caused by aeration can be better understood from investigations of the relationship between aeration and water evaporation from the sewage sludge bio-drying pile based on in situ measurements. This study was conducted to investigate the effects of forced air volume on the evaporation of water from a sewage sludge bio-drying pile. Dewatered sewage sludge was bio-dried using control technology for bio-drying, during which time the temperature, superficial air velocity and water evaporation were measured and calculated. The results indicated that the peak air velocity and water evaporation occurred in the thermophilic phase and second temperature-increasing phase, with the highest values of 0.063 ± 0.027 m s(-1) and 28.9 kg ton(-1) matrix d(-1), respectively, being observed on day 4. Air velocity above the pile during aeration was 43-100% higher than when there was no aeration, and there was a significantly positive correlation between air volume and water evaporation from day 1 to 15. The order of daily means of water evaporation was thermophilic phase > second temperature-increasing phase > temperature-increasing phase > cooling phase. Forced aeration controlled the pile temperature and improved evaporation, making it the key factor influencing water loss during the process of sewage sludge bio-drying. Copyright © 2013 Elsevier Ltd. All rights reserved.

Growth responses of male broilers subjected to increasing air velocities at high ambient temperatures and a high dew point.

Science.gov (United States)

Dozier, W A; Lott, B D; Branton, S L

2005-06-01

This study examined live performance responses of male broilers to increasing air velocity of 120 and 180 m/min reared under high cyclic temperatures (25-35-25 degrees C) with a 23 degrees C dew point from 21 to 49 d. Birds were reared in an environmental facility containing 2 wind tunnels (4 pens/tunnel) and 6 floor pens (control). At 21 d, 53 birds were placed in each pen of the wind tunnels and control group, respectively, and growth performance was determined weekly. Increasing air velocity from 120 to 180 m/min improved BW and BW gain from 29 to 35, 36 to 42, and 43 to 49 d of age leading to a cumulative advantage of 287 g in BW gain and a 10-point difference in feed conversion from 21 to 49 d of age. Subjecting birds to air velocity improved growth rate, feed consumption, and feed conversion at each weekly interval from 28 to 49 d over the control birds. These results indicate that male broilers approximating 2.0 to 3.0 kg respond to an air velocity of 180 m/min when exposed to high cyclic temperatures.

Spatially and Temporally Resolved Measurements of Velocity in a H2-air Combustion-Heated Supersonic Jet

Science.gov (United States)

Bivolaru, Daniel; Cutler, Andrew D.; Danehy, Paul M.; Gaffney, Richard L.; Baurle, Robert a.

2009-01-01

This paper presents simultaneous measurements at multiple points of two orthogonal components of flow velocity using a single-shot interferometric Rayleigh scattering (IRS) technique. The measurements are performed on a large-scale Mach 1.6 (Mach 5.5 enthalpy) H2-air combustion jet during the 2007 test campaign in the Direct Connect Supersonic Combustion Test facility at NASA Langley Research Center. The measurements are performed simultaneously with CARS (Coherent Anti-stokes Raman Spectroscopy) using a combined CARS-IRS instrument with a common path 9-nanosecond pulsed, injection-seeded, 532-nm Nd:YAG laser probe pulse. The paper summarizes the measurements of velocities along the core of the vitiated air flow as well as two radial profiles. The average velocity measurement near the centerline at the closest point from the nozzle exit compares favorably with the CFD calculations using the VULCAN code. Further downstream, the measured axial velocity shows overall higher values than predicted with a trend of convergence at further distances. Larger discrepancies are shown in the radial profiles.

Transition from slug to annular flow in horizontal air-water flow

International Nuclear Information System (INIS)

Reismann, J.; John, H.; Seeger, W.

1981-11-01

The transition from slug to annular flow in horizontal air-water and steam-water flow was investigated. Test sections of 50; 66.6 and 80 mm ID were used. The system pressure was 0.2 and 0.5 MPa in the air-water experiments and 2.5; 5; 7.5 and 10 MPa in the steam-water experiments. For flow pattern detection local impedance probes were used. This method was compared in a part of the experiments with differential pressure and gamma-beam measurements. The flow regime boundary is shifting strongly to smaller values of the superficial gas velocity with increasing pressure. Correlations from literature fit unsatisfactorily the experimental results. A new correlation is presented. (orig.) [de

Laminar burning velocities of near-flammability-limit H{sub 2}-air-steam mixtures

Energy Technology Data Exchange (ETDEWEB)

Loesel Sitar, J V; Chan, C K; Torchia, F; Guerrero, A

1996-12-31

Laminar burning velocities of lean H{sub 2}-air-steam mixtures near the flammability limit were measured by using the pressure-time history of an expanding flame kernel. Although flames in these mixtures are inherently unstable, this difficulty was avoided by using the early pressure rise of the burn. A comparison of results from that method with burning velocities determined from schlieren photographs of the expanding flame kernel gave good agreement. Despite the difficulties, it is believed that the pressure trace method gives results that are useful in modelling reactor accident scenarios. 8 refs., 4 figs.

Combustion of a high-velocity hydrogen microjet effluxing in air

Science.gov (United States)

Kozlov, V. V.; Grek, G. R.; Korobeinichev, O. P.; Litvinenko, Yu. A.; Shmakov, A. G.

2016-09-01

This study is devoted to experimental investigation of hydrogen-combustion modes and the structure of a diffusion flame formed at a high-velocity efflux of hydrogen in air through round apertures of various diameters. The efflux-velocity range of the hydrogen jet and the diameters of nozzle apertures at which the flame is divided in two zones with laminar and turbulent flow are found. The zone with the laminar flow is a stabilizer of combustion of the flame as a whole, and in the zone with the turbulent flow the intense mixing of fuel with an oxidizer takes place. Combustion in these two zones can occur independently from each other, but the steadiest mode is observed only at the existence of the flame in the laminar-flow zone. The knowledge obtained makes it possible to understand more deeply the features of modes of microjet combustion of hydrogen promising for various combustion devices.

Simulation of air velocity in a vertical perforated air distributor

Science.gov (United States)

Ngu, T. N. W.; Chu, C. M.; Janaun, J. A.

2016-06-01

Perforated pipes are utilized to divide a fluid flow into several smaller streams. Uniform flow distribution requirement is of great concern in engineering applications because it has significant influence on the performance of fluidic devices. For industrial applications, it is crucial to provide a uniform velocity distribution through orifices. In this research, flow distribution patterns of a closed-end multiple outlet pipe standing vertically for air delivery in the horizontal direction was simulated. Computational Fluid Dynamics (CFD), a tool of research for enhancing and understanding design was used as the simulator and the drawing software SolidWorks was used for geometry setup. The main purpose of this work is to establish the influence of size of orifices, intervals between outlets, and the length of tube in order to attain uniformity of exit flows through a multi outlet perforated tube. However, due to the gravitational effect, the compactness of paddy increases gradually from top to bottom of dryer, uniform flow pattern was aimed for top orifices and larger flow for bottom orifices.

Velocity and phase distribution measurements in vertical air-water annular flows

International Nuclear Information System (INIS)

Vassallo, P.

1997-07-01

Annular flow topology for three air-water conditions in a vertical duct is investigated through the use of a traversing double-sensor hot-film anemometry probe and differential pressure measurements. Near wall measurements of mean and fluctuating velocities, as well as local void fraction, are taken in the liquid film, with the highest turbulent fluctuations occurring for the flow condition with the largest pressure drop. A modified law-of-the-wall formulation for wall shear is presented which, using near wall values of mean velocity and kinetic energy, agrees reasonably well with the average stress obtained from direct pressure drop measurements. The linear profile using wall coordinates in the logarithmic layer is preserved in annular flow; however, the slope and intercept of the profile differ from the single-phase values for the annular flow condition which has a thicker, more turbulent, liquid film

Superficial basal cell carcinoma: A comparison of superficial only subtype with superficial combined with other subtypes by age, sex and anatomic site in 3150 cases.

Science.gov (United States)

Pyne, John H; Myint, Esther; Barr, Elizabeth M; Clark, Simon P; David, Michael; Na, Renua; Hou, Ruihang

2017-08-01

Basal cell carcinoma (BCC) may present as superficial subtype alone (sBCC) or superficial combined with other subtypes. The objective of this study was to compare sBCC without or with other BCC subtypes by age, sex and anatomic site. We retrospectively collected superficial BCC with the above characteristics from an Australian center during 2009 to 2014. We recorded 1528 sBCC and 1622 superficial BCC combined with other BCC subtype cases. Males numbered 2007 and females 1140. On males, head sites (forehead, cheek, nose and ear combined) compared to limb plus trunk sites displayed a higher incidence of superficial BCC combined with either nodular and or aggressive BCC subtypes (OR 13.15 CI 95% 8.9-19.5 P < .0001). On females a similar comparison also found a higher incidence of superficial BCC combined with solid subtype BCC on head sites compared to trunk and limb sites (OR 9.66 CI 95% 5.8-16.1 P < .0001). Superficial BCC alone is more likely on younger females on trunk and limb sites. Small partial biopsies reported as sBCC may miss other BCC subtypes present with higher risk on facial sites for males and females. Males had smaller proportions of superficial only subtype BCC on facial and ear sites compared to females. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Superficial skin ulcers

International Nuclear Information System (INIS)

Samaila, Modupeola O.; Rafindadi, Abdulmumini H.; Oluwole, Olabode P.; Adewuyi, Sunday A.

2007-01-01

Objective was to determine the underlying cause of superficial skin ulcers over a 15-year period. A retrospective histopathological analysis of 670 cases of superficial skin ulcers diagnosed in the Dept. of Pathology, Ahmadu Bello University Teaching Hospital, Zaria, Nigeria from January 1991 to December 2005. A total of 670 superficial skin ulcers were analyzed. The mail to female gender ratio was 409:261(1.5:1.0) and a peakage frequency of 44.3 %( 297) in the 5th and 6th decades. Spectrum of lesions encountered was categorized into inflammatory, infections, benign and malignant diseases. The malignant lesions were 309 (46.1%), non-specific inflammation 302 (45.1%), granulation tissue 25 (3.7%) and pseudoepitheliomatous hyperplasia 14 (2.1%). A total of 18(2.7%) specific infections were encountered, which included bacterial, fungal and viral infection. Benign lesions were 2(0.3%), comprising of neurofibroma and Bowen's disease. The most common malignant lesion was squamous cell carcinoma 203 (30.3%) with a male to female ratio of 128:75 (1.7:1.0). Of these 161 were well differentiated tumors. The lower limb was the prevalent site distribution of all the ulcers. Superficial ulcers may be harbinger of malignant diseases. Squamous cell carcinoma remains the most common malignant lesion arising from chronic superficial ulcers from our setting. Adequate tissue biopsy and early diagnosis may reduce the attendant morbidity of these ulcers. (author)

Experimental study of convective heat transfer during cooling with low air velocity in a stack of objects

Energy Technology Data Exchange (ETDEWEB)

Ben Amara, Sami; Laguerre, Onrawee [Cemagref - Refrigeration Processes Engineering Research Unit, parc de Tourvoie, BP 44, 92163 cedex, Antony (France); Flick, Denis [National Agronomic Institute - INAPG, 16 rue Claude Bernard, 75231 cedex 05, Paris (France)

2004-12-01

During cooling with low air velocity (u{<=}0.2 m.s{sup -1}) of a stack of foodstuffs (a few centimeters dimension), the radiation and conduction between products can be of the same order of magnitude as convection. A method was developed to quantify these various transfer modes. The experiment was carried out using an in-line spherical arrangement; however, the same methodology can be applied to other product shapes. The results confirm that the heat transfers by radiation and conduction cannot be neglected. In addition, the convective heat transfer coefficient varies not only with air velocity but also with the product position in the stack. (authors)

A Dual Conductance Sensor for Simultaneous Measurement of Void Fraction and Structure Velocity of Downward Two-Phase Flow in a Slightly Inclined Pipe.

Science.gov (United States)

Lee, Yeon-Gun; Won, Woo-Youn; Lee, Bo-An; Kim, Sin

2017-05-08

In this study, a new and improved electrical conductance sensor is proposed for application not only to a horizontal pipe, but also an inclined one. The conductance sensor was designed to have a dual layer, each consisting of a three-electrode set to obtain two instantaneous conductance signals in turns, so that the area-averaged void fraction and structure velocity could be measured simultaneously. The optimum configuration of the electrodes was determined through numerical analysis, and the calibration curves for stratified and annular flow were obtained through a series of static experiments. The fabricated conductance sensor was applied to a 45 mm inner diameter U-shaped downward inclined pipe with an inclination angle of 3° under adiabatic air-water flow conditions. In the tests, the superficial velocities ranged from 0.1 to 3.0 m/s for water and from 0.1 to 18 m/s for air. The obtained mean void fraction and the structure velocity from the conductance sensor were validated against the measurement by the wire-mesh sensor and the cross-correlation technique for the visualized images, respectively. The results of the flow regime classification and the corresponding time series of the void fraction at a variety of flow velocities were also discussed.

Influence of wind velocity fluctuation on air temperature difference between the fan and ground levels and the effect of frost protective fan operation

International Nuclear Information System (INIS)

Araki, T.; Matsuo, K.; Miyama, D.; Sumikawa, O.; Araki, S.

2008-01-01

We invested the influence of wind velocity fluctuation on air temperature difference between the fan (4.8 m) and ground levels (0.5 m) and the effect of frost protective fan operation in order to develop a new method to reduce electricity consumption due to frost protective fan operation. The results of the investigations are summarized as follows: (1) Air temperature difference between the fan (4.8 m) and ground levels (0.5 m) was decreased following an increase in wind velocity, and the difference was less than 1°C for a wind velocity more than 3.0 m/s at a height of 6.5 m. (2) When the wind velocity was more than 2-3 m/s, there was hardly any increase in the temperature of the leaves. In contrast, when the wind velocity was less than 2-3 m/s, an increase in the temperature of the leaves was observed. Based on these results, it is possible that when the wind velocity is greater than 2-3 m, it prevents thermal inversion. Therefore, there would be no warmer air for the frost protective fan to return to the tea plants and the air turbulence produced by the frost protective fan would not reach the plants under the windy condition

Entrapped air bubbles in piezo-driven inkjet printing: their effect on the droplet velocity

NARCIS (Netherlands)

Jong, de J.; Jeurissen, R.J.M.; Borel, H.; Berg, van den M.; Versluis, M.; Wijshoff, H.M.A.; Prosperetti, A.; Reinten, H.; Lohse, D.

2006-01-01

Air bubbles entrapped in the ink channel are a major problem in piezo-driven inkjet printing. They grow by rectified diffusion and eventually counteract the pressure buildup at the nozzle, leading to a breakdown of the jetting process. Experimental results on the droplet velocity udrop as a function

Entrapped air bubbles in piezo-driven inkjet printing: Their effect on the droplet velocity

NARCIS (Netherlands)

de Jong, J.; Jeurissen, R.J.M.; Borel, Huub; van den Berg, Marc; Wijshoff, Herman; Versluis, Michel; Wijshoff, H.; Reinten, Hans; Prosperetti, Andrea; Lohse, Detlef

2006-01-01

Air bubbles entrapped in the ink channel are a major problem in piezo-driven inkjet printing. They grow by rectified diffusion and eventually counteract the pressure buildup at the nozzle, leading to a breakdown of the jetting process. Experimental results on the droplet velocity udrop as a function

A method for predicting the impact velocity of a projectile fired from a compressed air gun facility

International Nuclear Information System (INIS)

Attwood, G.J.

1988-03-01

This report describes the development and use of a method for calculating the velocity at impact of a projectile fired from a compressed air gun. The method is based on a simple but effective approach which has been incorporated into a computer program. The method was developed principally for use with the Horizontal Impact Facility at AEE Winfrith but has been adapted so that it can be applied to any compressed air gun of a similar design. The method has been verified by comparison of predicted velocities with test data and the program is currently being used in a predictive manner to specify test conditions for the Horizontal Impact Facility at Winfrith. (author)

Human preference and acceptance of increased air velocity to offset warm sensation at increased room temperatures

OpenAIRE

Cattarin, Giulio; Simone, Angela; Olesen, Bjarne W.

2012-01-01

Previous studies have demonstrated that in summertime increased air velocities can compensate for higher room temperatures to achieve comfortable conditions. In order to increase air movement, windows opening, ceiling or desk fans can be used at the expense of relatively low energy consumption. The present climatic chamber study examined energy performance and achievable thermal comfort of traditional and bladeless desk fans. Different effects of mechanical and simulated-natural airflow patte...

A numerical scheme to calculate temperature and salinity dependent air-water transfer velocities for any gas

Science.gov (United States)

Johnson, M. T.

2010-02-01

The transfer velocity determines the rate of exchange of a gas across the air-water interface for a given deviation from Henry's law equilibrium between the two phases. In the thin film model of gas exchange, which is commonly used for calculating gas exchange rates from measured concentrations of trace gases in the atmosphere and ocean/freshwaters, the overall transfer is controlled by diffusion-mediated films on either side of the air-water interface. Calculating the total transfer velocity (i.e. including the influence from both molecular layers) requires the Henry's law constant and the Schmidt number of the gas in question, the latter being the ratio of the viscosity of the medium and the molecular diffusivity of the gas in the medium. All of these properties are both temperature and (on the water side) salinity dependent and extensive calculation is required to estimate these properties where not otherwise available. The aim of this work is to standardize the application of the thin film approach to flux calculation from measured and modelled data, to improve comparability, and to provide a numerical framework into which future parameter improvements can be integrated. A detailed numerical scheme is presented for the calculation of the gas and liquid phase transfer velocities (ka and kw respectively) and the total transfer velocity, K. The scheme requires only basic physical chemistry data for any gas of interest and calculates K over the full range of temperatures, salinities and wind-speeds observed in and over the ocean. Improved relationships for the wind-speed dependence of ka and for the salinity-dependence of the gas solubility (Henry's law) are derived. Comparison with alternative schemes and methods for calculating air-sea flux parameters shows good agreement in general but significant improvements under certain conditions. The scheme is provided as a downloadable program in the supplementary material, along with input files containing molecular

Velocity Estimate Following Air Data System Failure

National Research Council Canada - National Science Library

McLaren, Scott A

2008-01-01

.... A velocity estimator (VEST) algorithm was developed to combine the inertial and wind velocities to provide an estimate of the aircraft's current true velocity to be used for command path gain scheduling and for display in the cockpit...

Transverse Oscillations for Phased Array Vector Velocity Imaging

DEFF Research Database (Denmark)

Pihl, Michael Johannes; Jensen, Jørgen Arendt

2010-01-01

of superficial blood vessels. To broaden the usability of the method, it should be expanded to a phased array geometry enabling vector velocity imaging of the heart. Therefore, the scan depth has to be increased to 10-15 cm. This paper presents suitable pulse echo fields (PEF). Two lines are beamformed...... (correlation coefficient, R: -0.76), and therefore predict estimator performance. CV is correlated with the standard deviation (R=0.74). The results demonstrate the potential for using a phased array for vector velocity imaging at larger depths, and potentially for imaging the heart....

Effects of air temperature and velocity on the drying kinetics and product particle size of starch from arrowroot (Maranta arundinacae)

Science.gov (United States)

Caparanga, Alvin R.; Reyes, Rachael Anne L.; Rivas, Reiner L.; De Vera, Flordeliza C.; Retnasamy, Vithyacharan; Aris, Hasnizah

2017-11-01

This study utilized the 3k factorial design with k as the two varying factors namely, temperature and air velocity. The effects of temperature and air velocity on the drying rate curves and on the average particle diameter of the arrowroot starch were investigated. Extracted arrowroot starch samples were dried based on the designed parameters until constant weight was obtained. The resulting initial moisture content of the arrowroot starch was 49.4%. Higher temperatures correspond to higher drying rates and faster drying time while air velocity effects were approximately negligible or had little effect. Drying rate is a function of temperature and time. The constant rate period was not observed for the drying rate of arrowroot starch. The drying curves were fitted against five mathematical models: Lewis, Page, Henderson and Pabis, Logarithmic and Midili. The Midili Model was the best fit for the experimental data since it yielded the highest R2 and the lowest RSME values for all runs. Scanning electron microscopy (SEM) was used for qualitative analysis and for determination of average particle diameter of the starch granules. The starch granules average particle diameter had a range of 12.06 - 24.60 μm. The use of ANOVA proved that particle diameters for each run varied significantly with each other. And, the Taguchi Design proved that high temperatures yield lower average particle diameter, while high air velocities yield higher average particle diameter.

Pneumodissection for skin protection in image-guided cryoablation of superficial musculoskeletal tumours.

Science.gov (United States)

Maybody, Majid; Tang, Peter Q; Moskowitz, Chaya S; Hsu, Meier; Yarmohammadi, Hooman; Boas, F Edward

2017-03-01

Pneumodissection is described as a simple method for preventing skin injury during cryoablation of superficial musculoskeletal tumours. Superficial tumour cryoablations performed from 2009 to 2015 were retrospectively reviewed. Pneumodissection was performed in 13 patients when the shortest tumour-skin distance was less than 25 mm. Indications were pain palliation (n = 9) and local tumour control (n = 4). Patients, target tumours, technical characteristics and complications up to 60 days post ablation were reviewed. The ice ball-skin distances with and without pneumodissection were compared by a paired t-test and further assessed for association with covariates using ANCOVA. Technical success for ablation was 12 of 13. The mean shortest tumour-skin distance was 15.0 mm (3.2-24.5 mm). The mean thickness of pneumodissection was 9.6 mm (5.2-16.6 mm) resulting in mean elevation of skin of 3.4 mm (1.2-5.3 mm). Mean shortest ice ball-skin distance after pneumodissection was 10.5 mm (4.2-19.7 mm). No infection or systemic air embolism was noted. No intraprocedural frostbite was observed. Pneumodissection is feasible, effective and safe in protecting the skin during image-guided cryoablation of superficial tumours. • Frostbite during image-guided cryoablation of superficial tumours is commonly under-reported. • Frostbites are painful and may introduce infection into the superficial ablation zone. • Warm compress, saline and CO 2 have shortcomings in protecting the skin. • Pneumodissection is free, readily available, easy to use and safe and effective.

Hydrodynamic effects of air sparging on hollow fiber membranes in a bubble column reactor.

Science.gov (United States)

Xia, Lijun; Law, Adrian Wing-Keung; Fane, Anthony G

2013-07-01

Air sparging is now a standard approach to reduce concentration polarization and fouling of membrane modules in membrane bioreactors (MBRs). The hydrodynamic shear stresses, bubble-induced turbulence and cross flows scour the membrane surfaces and help reduce the deposit of foulants onto the membrane surface. However, the detailed quantitative knowledge on the effect of air sparging remains lacking in the literature due to the complex hydrodynamics generated by the gas-liquid flows. To date, there is no valid model that describes the relationship between the membrane fouling performance and the flow hydrodynamics. The present study aims to examine the impact of hydrodynamics induced by air sparging on the membrane fouling mitigation in a quantitative manner. A modelled hollow fiber module was placed in a cylindrical bubble column reactor at different axial heights with the trans-membrane pressure (TMP) monitored under constant flux conditions. The configuration of bubble column without the membrane module immersed was identical to that studied by Gan et al. (2011) using Phase Doppler Anemometry (PDA), to ensure a good quantitative understanding of turbulent flow conditions along the column height. The experimental results showed that the meandering flow regime which exhibits high flow instability at the 0.3 m is more beneficial to fouling alleviation compared with the steady flow circulation regime at the 0.6 m. The filtration tests also confirmed the existence of an optimal superficial air velocity beyond which a further increase is of no significant benefit on the membrane fouling reduction. In addition, the alternate aeration provided by two air stones mounted at the opposite end of the diameter of the bubble column was also studied to investigate the associated flow dynamics and its influence on the membrane filtration performance. It was found that with a proper switching interval and membrane module orientation, the membrane fouling can be effectively

Experimental investigation of the effect of air velocity on a unit cooler under frosting condition: a case study

Science.gov (United States)

Bayrak, Ergin; Çağlayan, Akın; Konukman, Alp Er S.

2017-10-01

Finned tube evaporators are used in a wide range of applications such as commercial and industrial cold/freezed storage rooms with high traffic loading under frosting conditions. In this case study, an evaporator with an integrated fan was manufactured and tested under frosting conditions by only changing the air flow rate in an ambient balanced type test laboratory compared to testing in a wind tunnel with a more uniform flow distribution in order to detect the effect of air flow rate on frosting. During the test, operation was performed separately based on three different air flow rates. The parameters concerning test operation such as the changes of air temperature, air relative humidity, surface temperature, air-side pressure drop and refrigerant side capacity etc. were followed in detail for each air flow rate. At the same time, digital images were captured in front of the evaporator; thus, frost thicknesses and blockage ratios at the course of fan stall were determined by using an image-processing technique. Consequently, the test and visual results showed that the trendline of air-side pressure drop increased slowly at the first stage of test operations, then increased linearly up to a top point and then the linearity was disrupted instantly. This point speculated the beginning of defrost operation for each case. In addition, despite detecting a velocity that needs to be avoided, a test applied at minimum air velocity is superior to providing minimum capacity in terms of loss of capacity during test operations.

Experimental study for flow regime of downward air-water two-phase flow in a vertical narrow rectangular channel

Energy Technology Data Exchange (ETDEWEB)

Kim, T. H.; Yun, B. J.; Jeong, J. H. [Pusan National University, Geunjeong-gu, Busan (Korea, Republic of)

2015-05-15

Studies were mostly about flow in upward flow in medium size circular tube. Although there are great differences between upward and downward flow, studies on vertical upward flow are much more active than those on vertical downward flow in a channel. In addition, due to the increase of surface forces and friction pressure drop, the pattern of gas-liquid two-phase flow bounded to the gap of inside the rectangular channel is different from that in a tube. The downward flow in a rectangular channel is universally applicable to cool the plate type nuclear fuel in research reactor. The sub-channel of the plate type nuclear fuel is designed with a few millimeters. Downward air-water two-phase flow in vertical rectangular channel was experimentally observed. The depth, width, and length of the rectangular channel is 2.35 mm, 66.7 mm, and 780 mm, respectively. The test section consists of transparent acrylic plates confined within a stainless steel frame. The flow patterns of the downward flow in high liquid velocity appeared to be similar to those observed in previous studies with upward flow. In downward flow, the transition lines for bubbly-slug and slug-churn flow shift to left in the flow regime map constructed with abscissa of the superficial gas velocity and ordinate of the superficial liquid velocity. The flow patterns observed with downward flow at low liquid velocity are different from those with upward flow.

Measurement of unsteady airflow velocity at nozzle outlet

Science.gov (United States)

Pyszko, René; Machů, Mário

2017-09-01

The paper deals with a method of measuring and evaluating the cooling air flow velocity at the outlet of the flat nozzle for cooling a rolled steel product. The selected properties of the Prandtl and Pitot sensing tubes were measured and compared. A Pitot tube was used for operational measurements of unsteady dynamic pressure of the air flowing from nozzles to abtain the flow velocity. The article also discusses the effects of air temperature, pressure and relative air humidity on air density, as well as the influence of dynamic pressure filtering on the error of averaged velocity.

Rotina computacional para a determinação da velocidade de sedimentação das partículas do solo em suspensão no escoamento superficial Computational routine for the determination of the sedimentation velocity of the soil particles in the drain

Directory of Open Access Journals (Sweden)

Luiz F. C. de Oliveira

2005-04-01

Full Text Available O presente trabalho teve como objetivo desenvolver uma rotina computacional para a determinação da velocidade de deposição de partículas em suspensão no escoamento superficial, verificar sua aplicação por intermédio de modelo de transporte de sedimentos e comparar os resultados obtidos com dados experimentais. Empregou-se na rotina o processo iterativo de Newton-Rapshon para a solução das equações empregadas na determinação da velocidade de deposição de partículas em suspensão no escoamento superficial, e na solução da equação do transporte de sedimentos empregou-se a técnica das diferenças finitas. Essas rotinas foram empregadas na implementação do modelo MTSES (Modelo para Transporte de Solutos no Solo e no Escoamento Superficial. As velocidades de queda das partículas obtidas pela rotina desenvolvida, em média, foram superestimadas, com erro relativo médio de 0,63%, o que possibilitou a utilização da rotina desenvolvida no MTSES. O modelo MTSES superestimou o total de sedimentos transportados pelo escoamento superficial para todas as intensidades de precipitação empregadas neste estudo, com variações porcentuais de 15,6 a 58,3%.The present work had as objective to develop a computational routine for the determination of the sedimentation velocity in the drain and to verify its application through a model of transport of sediments and to compare the results obtained with experimental data. It was used in the routine the iterative process of Newton-Rapshon for the solution of the equations applied in the determination of the sedimentation velocity in the drain, and on the solution of the transport of sediments equation was applied the technique of the finite differences. Those routines were used in the implementation of the model MTSES (Model for solute transport in the soil and in the drain. The sedimentation velocities obtained by the developed routine were overestimated, with a medium relative error of 0

A numerical scheme to calculate temperature and salinity dependent air-water transfer velocities for any gas

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M. T. Johnson

2010-10-01

Full Text Available The ocean-atmosphere flux of a gas can be calculated from its measured or estimated concentration gradient across the air-sea interface and the transfer velocity (a term representing the conductivity of the layers either side of the interface with respect to the gas of interest. Traditionally the transfer velocity has been estimated from empirical relationships with wind speed, and then scaled by the Schmidt number of the gas being transferred. Complex, physically based models of transfer velocity (based on more physical forcings than wind speed alone, such as the NOAA COARE algorithm, have more recently been applied to well-studied gases such as carbon dioxide and DMS (although many studies still use the simpler approach for these gases, but there is a lack of validation of such schemes for other, more poorly studied gases. The aim of this paper is to provide a flexible numerical scheme which will allow the estimation of transfer velocity for any gas as a function of wind speed, temperature and salinity, given data on the solubility and liquid molar volume of the particular gas. New and existing parameterizations (including a novel empirical parameterization of the salinity-dependence of Henry's law solubility are brought together into a scheme implemented as a modular, extensible program in the R computing environment which is available in the supplementary online material accompanying this paper; along with input files containing solubility and structural data for ~90 gases of general interest, enabling the calculation of their total transfer velocities and component parameters. Comparison of the scheme presented here with alternative schemes and methods for calculating air-sea flux parameters shows good agreement in general. It is intended that the various components of this numerical scheme should be applied only in the absence of experimental data providing robust values for parameters for a particular gas of interest.

A numerical scheme to calculate temperature and salinity dependent air-water transfer velocities for any gas

Science.gov (United States)

Johnson, M. T.

2010-10-01

The ocean-atmosphere flux of a gas can be calculated from its measured or estimated concentration gradient across the air-sea interface and the transfer velocity (a term representing the conductivity of the layers either side of the interface with respect to the gas of interest). Traditionally the transfer velocity has been estimated from empirical relationships with wind speed, and then scaled by the Schmidt number of the gas being transferred. Complex, physically based models of transfer velocity (based on more physical forcings than wind speed alone), such as the NOAA COARE algorithm, have more recently been applied to well-studied gases such as carbon dioxide and DMS (although many studies still use the simpler approach for these gases), but there is a lack of validation of such schemes for other, more poorly studied gases. The aim of this paper is to provide a flexible numerical scheme which will allow the estimation of transfer velocity for any gas as a function of wind speed, temperature and salinity, given data on the solubility and liquid molar volume of the particular gas. New and existing parameterizations (including a novel empirical parameterization of the salinity-dependence of Henry's law solubility) are brought together into a scheme implemented as a modular, extensible program in the R computing environment which is available in the supplementary online material accompanying this paper; along with input files containing solubility and structural data for ~90 gases of general interest, enabling the calculation of their total transfer velocities and component parameters. Comparison of the scheme presented here with alternative schemes and methods for calculating air-sea flux parameters shows good agreement in general. It is intended that the various components of this numerical scheme should be applied only in the absence of experimental data providing robust values for parameters for a particular gas of interest.

Seasonal and Daily Variations of Subsurface Velocity Revealed by the Air-gun Source in Binchuan, Yunnan, China

Science.gov (United States)

Luan, Y.; Yang, H.; Wang, B.

2017-12-01

We derive temporal variations of subsurface structure using a large-volume air-gun source excited in Binchuan, Yunnan, southwest China, the first transmitting seismic station that can generate high-quality repeating waveforms. The data were collected between January 2013 and December 2015 that were recorded by 40 stations within 150 km, including permanent and newly deployed air-gun array stations. Firstly, we conduct cluster analysis using the waveforms at the nearest station and find the clustering result is not only governed by the water level of the reservoir, but also has seasonal variations. Furthermore, we use the records of the nearest station to approximate the source time functions and then retrieve empirical Green's functions (EGF) by deconvolution. Then we obtain travel time difference by comparing the EGF. The travel time difference exhibits clear seasonal variation, and the pattern correlates the best with surface air temperature. The increasing temperature coincides with increasing delay time i.e. decreasing seismic velocity. We interpret the observed seasonal variation of subsurface velocity is partly caused by thermo-elastic strain. However, our calculated thermo-elastic strain is only half in amplitude of the observed strain, indicating other factors such as precipitation and ground water level may play a role in the subsurface changes. Moreover, we derive the daily variation of subsurface velocity in December 2015 when air-gun shots were made in every hour. The delay time clearly correlates with the barometric pressure change and the tidal strain. Here we demonstrate that both long-term (seasonal) and short-term (daily) structural variations can be derived using the newly constructed active source, which is a powerful tool to advance our understanding of rheological properties of the crust as well as well processes associated with earthquakes and other natural hazards.

Influence of current velocity and wind speed on air-water gas exchange in a mangrove estuary

Science.gov (United States)

Ho, David T.; Coffineau, Nathalie; Hickman, Benjamin; Chow, Nicholas; Koffman, Tobias; Schlosser, Peter

2016-04-01

Knowledge of air-water gas transfer velocities and water residence times is necessary to study the fate of mangrove derived carbon exported into surrounding estuaries and ultimately to determine carbon balances in mangrove ecosystems. For the first time, the 3He/SF6 dual tracer technique, which has been proven to be a powerful tool to determine gas transfer velocities in the ocean, is applied to Shark River, an estuary situated in the largest contiguous mangrove forest in North America. The mean gas transfer velocity was 3.3 ± 0.2 cm h-1 during the experiment, with a water residence time of 16.5 ± 2.0 days. We propose a gas exchange parameterization that takes into account the major sources of turbulence in the estuary (i.e., bottom generated shear and wind stress).

HIGH ORIGIN OF SUPERFICIAL ULNAR ARTERY- A CASE REPORT

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Anjana Jayakumaran Nair

2017-03-01

Full Text Available BACKGROUND High origin and superficially placed ulnar artery is a rare anatomical variant that usually arises either in the axilla or arm and runs a superficial course in the forearm, enters the hand and participates in the formation of superficial palmar arch. During routine dissection of cadavers in our department, we observed a unilateral case of high origin and superficial ulnar artery in a human male cadaver. It originated from the brachial artery in the lower third of arm 4 cm above its bifurcation. From its origin, it passed downwards along the medial aspect of forearm, superficial to the flexors, entered hand superficial to the flexor retinaculum and formed superficial palmar arch. The knowledge of existence of a superficial ulnar artery is important during vascular and reconstructive surgery and also in evaluation of angiographic images. Superficial position makes it more vulnerable to trauma and more accessible to cannulation.

Common Superficial Bursitis.

Science.gov (United States)

Khodaee, Morteza

2017-02-15

Superficial bursitis most often occurs in the olecranon and prepatellar bursae. Less common locations are the superficial infrapatellar and subcutaneous (superficial) calcaneal bursae. Chronic microtrauma (e.g., kneeling on the prepatellar bursa) is the most common cause of superficial bursitis. Other causes include acute trauma/hemorrhage, inflammatory disorders such as gout or rheumatoid arthritis, and infection (septic bursitis). Diagnosis is usually based on clinical presentation, with a particular focus on signs of septic bursitis. Ultrasonography can help distinguish bursitis from cellulitis. Blood testing (white blood cell count, inflammatory markers) and magnetic resonance imaging can help distinguish infectious from noninfectious causes. If infection is suspected, bursal aspiration should be performed and fluid examined using Gram stain, crystal analysis, glucose measurement, blood cell count, and culture. Management depends on the type of bursitis. Acute traumatic/hemorrhagic bursitis is treated conservatively with ice, elevation, rest, and analgesics; aspiration may shorten the duration of symptoms. Chronic microtraumatic bursitis should be treated conservatively, and the underlying cause addressed. Bursal aspiration of microtraumatic bursitis is generally not recommended because of the risk of iatrogenic septic bursitis. Although intrabursal corticosteroid injections are sometimes used to treat microtraumatic bursitis, high-quality evidence demonstrating any benefit is unavailable. Chronic inflammatory bursitis (e.g., gout, rheumatoid arthritis) is treated by addressing the underlying condition, and intrabursal corticosteroid injections are often used. For septic bursitis, antibiotics effective against Staphylococcus aureus are generally the initial treatment, with surgery reserved for bursitis not responsive to antibiotics or for recurrent cases. Outpatient antibiotics may be considered in those who are not acutely ill; patients who are acutely ill

Performance of a combined three-hole conductivity probe for void fraction and velocity measurement in air-water flows

Energy Technology Data Exchange (ETDEWEB)

Borges, Joao Eduardo [IDMEC, Instituto Superior Tecnico, Technical University of Lisbon, Department of Mechanical Engineering, Lisbon (Portugal); Pereira, Nuno H.C. [EST Setubal, Polytechnic Institute of Setubal, Department of Mechanical Engineering, Setubal (Portugal); Matos, Jorge [Instituto Superior Tecnico, Technical University of Lisbon, Department of Civil Engineering and Architecture, Lisbon (Portugal); Frizell, Kathleen H. [U.S. Bureau of Reclamation, Denver, CO (United States)

2010-01-15

The development of a three-hole pressure probe with back-flushing combined with a conductivity probe, used for measuring simultaneously the magnitude and direction of the velocity vector in complex air-water flows, is described in this paper. The air-water flows envisaged in the current work are typically those occurring around the rotors of impulse hydraulic turbines (like the Pelton and Cross-Flow turbines), where the flow direction is not known prior to the data acquisition. The calibration of both the conductivity and three-hole pressure components of the combined probe in a rig built for the purpose, where the probe was placed in a position similar to that adopted for the flow measurements, will be reported. After concluding the calibration procedure, the probe was utilized in the outside region of a Cross-Flow turbine rotor. The experimental results obtained in the present study illustrate the satisfactory performance of the combined probe, and are encouraging toward its use for characterizing the velocity field of other complex air-water flows. (orig.)

Performance of a combined three-hole conductivity probe for void fraction and velocity measurement in air-water flows

Science.gov (United States)

Borges, João Eduardo; Pereira, Nuno H. C.; Matos, Jorge; Frizell, Kathleen H.

2010-01-01

The development of a three-hole pressure probe with back-flushing combined with a conductivity probe, used for measuring simultaneously the magnitude and direction of the velocity vector in complex air-water flows, is described in this paper. The air-water flows envisaged in the current work are typically those occurring around the rotors of impulse hydraulic turbines (like the Pelton and Cross-Flow turbines), where the flow direction is not known prior to the data acquisition. The calibration of both the conductivity and three-hole pressure components of the combined probe in a rig built for the purpose, where the probe was placed in a position similar to that adopted for the flow measurements, will be reported. After concluding the calibration procedure, the probe was utilized in the outside region of a Cross-Flow turbine rotor. The experimental results obtained in the present study illustrate the satisfactory performance of the combined probe, and are encouraging toward its use for characterizing the velocity field of other complex air-water flows.

Air-Induced Drag Reduction at High Reynolds Numbers: Velocity and Void Fraction Profiles

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Elbing, Brian; Mäkiharju, Simo; Wiggins, Andrew; Dowling, David; Perlin, Marc; Ceccio, Steven

2010-11-01

The injection of air into a turbulent boundary layer forming over a flat plate can reduce the skin friction. With sufficient volumetric fluxes an air layer can separate the solid surface from the flowing liquid, which can produce drag reduction in excess of 80%. Several large scale experiments have been conducted at the US Navy's Large Cavitation Channel on a 12.9 m long flat plate model investigating bubble drag reduction (BDR), air layer drag reduction (ALDR) and the transition between BDR and ALDR. The most recent experiment acquired phase velocities and void fraction profiles at three downstream locations (3.6, 5.9 and 10.6 m downstream from the model leading edge) for a single flow speed (˜6.4 m/s). The profiles were acquired with a combination of electrode point probes, time-of-flight sensors, Pitot tubes and an LDV system. Additional diagnostics included skin-friction sensors and flow-field image visualization. During this experiment the inlet flow was perturbed with vortex generators immediately upstream of the injection location to assess the robustness of the air layer. From these, and prior measurements, computational models can be refined to help assess the viability of ALDR for full-scale ship applications.

Drenaje suplementario del sistema venoso superficial en colgajos pediculados Supplementary drainage of superficial venous system in pedicled flaps

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A. Fernández García

2012-06-01

Full Text Available Los colgajos pediculados pueden sufrir edema y congestión debido a que su drenaje a trevés del sistema venoso superfical es imposible y el flujo hacia el sistema profundo a nivel del pedículo es precario. Esta situación suele evolucionar hacia la necrosis parcial o la pérdida total del colgajo en pocas horas. La apertura del sistema venoso superficial permite el drenaje adecuado de los tejidos transferidos y evita estas complicaciones. Este artículo analiza el papel de las anastomosis microquirúrgicas en el sistema venoso superficial de los colgajos pediculados. Esta técnica permite comunicar el sistema venoso superfical de los tejidos transferidos con el sistema venoso superficial del territorio que rodea al defecto. Presentamos los resultados obtenidos con esta técnica en colgajos de perforante en hélice, colgajos miocutáneos, colgajos neurocutáneos y colgajos fasciograsos volteados.The pedicled flaps can suffer edema and congestion due to the impossibility of drainage toward the superficial venous system and the precarious flow via the deep system at the level of the pedicle. The evolution of this situation is usually partial necrosis or total loss of the flap in a few hours. The opening of the venous superficial system achieves an appropriate drainage of the transfered tissues and avoids these complications. In this article we analyze the role of the microsurgical anastomosis at the level of the superficial venous system of pedicled flaps. This technique allows to communicate the superficial venous system of the transfered tissues with the superficial venous system of the territory around the defect. We report the results with this method in propeller perforator flaps, miocutaneous flaps, neurocutaneous flaps and adipofascial turn over flaps.

Modified Functional Superficial Parotidectomy With Ligation of the Major Branch of the Parotid Duct Extending to the Superficial Lobe.

Science.gov (United States)

Chang, Jung Woo; Leem, Soo Seong; Choi, Hwan Jun; Lee, Jang Hyun

2017-05-01

A functional superficial parotidectomy can maintain salivary function by preserving the Stensen duct. However, this technique still brings the possibility of salivary leakage, because major branches of the parotid duct from the resected site do not get ligated. To reduce this complication, this study introduces a modified technique with major branch ligation. From December 2008 to February 2015, 14 patients who underwent superficial parotidectomy were divided into 2 groups. Group A was treated with the modified functional superficial parotidectomy involving the major branch between the superficial lobe and parotid duct. Group B was treated with the conventional superficial parotidectomy without involving the major branch of the parotid duct. The clinical complications, period of Hemovac usage, and surgical duration were noted in each group. Two of 8 patients in group A had a major branch from Stensen duct that was ligated, and there was no evidence of salivary leakage or sialocele in any of the patients of group A, whereas group B contained 2 cases of salivary leakage, one of which became sialocele. Group A had a significantly longer Hemovac maintenance period than group B (P < 0.05), and the duration of surgery was also significantly different between the 2 groups (P < 0.05). Because a solitary major branch of the main parotid duct occasionally extends toward the superficial lobe, our modified technique-functional superficial parotidectomy with ligation of the major branch toward the superficial lobe-is a useful option for treatment of a benign parotid mass in such cases.

Effect of Airflow Velocity on Pre-cooling Process of Pomegranate by Forced Cooling Air under Unsteady State Heat Transfer Condition

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M. A Behaeen

2018-03-01

Full Text Available Introduction Pomegranate (Punica grantum L. is classified into the family of Punicaceae. One of the most influential factors in postharvest life and quality of horticultural products is temperature. In precooling, heat is reduced in fruit and vegetable after harvesting to prepare it quickly for transport and storage. Fikiin (1983, Dennis (1984 and Hass (1976 reported that cold air velocity is one of the effective factors in cooling vegetables and fruits. Determining the time-temperature profiles is an important step in cooling process of agricultural products. The objective of this study was the analysis of cooling rate in the center (arils and outer layer (peel of pomegranate and comparison of the two sections at different cold air velocities. These results are useful for designing and optimizing the precooling systems. Materials and Methods The pomegranate variety was Rabab (thick peel and the experiments were performed on arils (center and peel (outer layer of a pomegranate. The velocities of 0.5, 1 and 1.3 m s-1 were selected for testing. To perform the research, the cooling instrument was designed and built at Department of Biosystems Engineering of Tabriz University, Tabriz, Iran. In each experiment six pt100 temperature sensors was used in a single pomegranate. The cooling of pomegranate was continued until the central temperature reached to 10°C and then the instrument turned off. The average of air and product temperatures was 7.2 and 22.2°C, respectively. The following parameters were measured to analyze the process of precooling: a Dimensionless temperature (θ, b Cooling coefficient (C, c Lag factor (J, d Half-cooling time (H, e Seven-eighths cooling time (S, f Cooling heterogeneity, g Fruit mass loss, h Instantaneous cooling rate, and i convective heat transfer coefficient. Results and Discussion At any air velocity, with increasing the radius from center to outer layer, the lag factor decreased and cooling coefficient increased

Multi-objective optimization of cooling air distributions of grate cooler with different clinker particles diameters and air chambers by genetic algorithm

International Nuclear Information System (INIS)

Shao, Wei; Cui, Zheng; Cheng, Lin

2017-01-01

Highlights: • A multi-objective optimization model of air distributions of grate cooler by genetic algorithm is proposed. • Optimal air distributions of different conditions are obtained and validated by measurements. • The most economic average diameters of clinker particles is 0.02 m. • The most economic amount of air chambers is 9. - Abstract: The paper proposes a multi-objective optimization model of cooling air distributions of grate cooler in cement plant based on convective heat transfer principle and entropy generation minimization analysis. The heat transfer and flow models of clinker cooling process are brought out at first. Then the modified entropy generation numbers caused by heat transfer and viscous dissipation are considered as objective functions respectively which are optimized by genetic algorithm simultaneously. The design variables are superficial velocities of air chambers and thicknesses of clinker layer on different grate plates. The model is verified by a set of Pareto optimal solutions and scattered distributions of design variables. Sensitive analysis of average diameters of clinker particles and amount of air chambers are carried out based on the optimization model. The optimal cooling air distributions are compared by heat recovered, energy consumption of cooling fans and heat efficiency of grate cooler. And all of them are selected from the Pareto optimal solutions based on energy consumption of cooling fans minimization. The results show that the most effective and economic average diameter of clinker particles is 0.02 m and the amount of air chambers is 9.

CO2 capture from air by Chlorella vulgaris microalgae in an airlift photobioreactor.

Science.gov (United States)

Sadeghizadeh, Aziz; Farhad Dad, Farid; Moghaddasi, Leila; Rahimi, Rahbar

2017-11-01

In this work, hydrodynamics and CO 2 biofixation study was conducted in an airlift bioreactor at the temperature of 30±2°C. The main objective of this work was to investigate the effect of high gas superficial velocity on CO 2 biofixation using Chlorella vulgaris microalgae and its growth. The study showed that Chlorella vulgaris in high input gas superficial velocity also had the ability to grow and remove the CO 2 by less than 80% efficiency. Copyright © 2017 Elsevier Ltd. All rights reserved.

Calculation of the Arc Velocity Along the Polluted Surface of Short Glass Plates Considering the Air Effect

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Tao Yuan

2012-03-01

Full Text Available To investigate the microphysics mechanism and the factors that influence arc development along a polluted surface, the arc was considered as a plasma fluid. Based on the image method and the collision ionization theory, the electric field of the arc needed to maintain movement with different degrees of pollution was calculated. According to the force of the charged particle in an arc plasma stressed under an electric field, a calculation model of arc velocity, which is dependent on the electric field of the arc head that incorporated the effects of airflow around the electrode and air resistance is presented. An experiment was carried out to measure the arc velocity, which was then compared with the calculated value. The results of the experiment indicated that the lighter the pollution is, the larger the electric field of the arc head and arc velocity is; when the pollution is heavy, the effect of thermal buoyancy that hinders arc movement increases, which greatly reduces the arc velocity.

Measurements of local liquid velocity and interfacial parameters of air-water bubbly flows in a horizontal tube

International Nuclear Information System (INIS)

Yang Jian; Zhang Mingyuan; Zhang Chaojie; Su Yuliang

2002-01-01

Distribution of local kinematic parameters of air-water bubbly flows in a horizontal tube with an ID of 35 mm was investigated. The local liquid velocity was measured with a cylindrical hot film probe, and local void fraction, bubble frequency and bubble velocity were measured with a double-sensor probe. It was found that the axial liquid velocity has a same profile as that of single liquid phase flow in the lower part of the tube, and it suffers a sudden reduction in the upper part of the tube. With increasing airflow rate, the liquid velocity would increase in the lower part of the tube, and further decrease at the upper part of the tube, respectively. Most bubbles are congested at the upper part of the tube, and the void fraction and bubble frequencies have similar profile and both are asymmetrical with the tube axis with their maximum values located near the upper tube wall

Influence of inlet velocity of air and solid particle feed rate on holdup mass and heat transfer characteristics in cyclone heat exchanger

International Nuclear Information System (INIS)

Mothilal, T.; Pitchandi, K.

2015-01-01

Present work elaborates the effect of inlet velocity of air and solid particle feed rate on holdup mass and heat transfer characteristics in a cyclone heat exchanger. The RNG k-ε turbulence model was adopted for modeling high turbulence flow and Discrete phase model (DPM) to track solid particles in a cyclone heat exchanger by ANSYS FLUENT software. The effect of inlet air velocity (5 to 25 m/s) and inlet solid particle feed rate of (0.2 to 2.5 g/s) at different particle diameter (300 to 500 μm) on holdup mass and heat transfer rate in cyclone heat exchanger was studied at air inlet temperature of 473 K. Results show that holdup mass and heat transfer rate increase with increase in inlet air velocity and inlet solid particle feed rate. Influence of solid particle feed rate on holdup mass has more significance. Experimental setup was built for high efficiency cyclone. Good agreement was found between experimental and simulation pressure drop. Empirical correlation was derived for dimensionless holdup mass and Nusselt number based on CFD data by regression technique. Correlation predicts dimensional holdup mass with +5% to -8% errors of experimental data and Nusselt number with +9% to -3%

Influence of inlet velocity of air and solid particle feed rate on holdup mass and heat transfer characteristics in cyclone heat exchanger

Energy Technology Data Exchange (ETDEWEB)

Mothilal, T. [T. J. S. Engineering College, Gummidipoond (India); Pitchandi, K. [Sri Venkateswara College of Engineering, Sriperumbudur (India)

2015-10-15

Present work elaborates the effect of inlet velocity of air and solid particle feed rate on holdup mass and heat transfer characteristics in a cyclone heat exchanger. The RNG k-ε turbulence model was adopted for modeling high turbulence flow and Discrete phase model (DPM) to track solid particles in a cyclone heat exchanger by ANSYS FLUENT software. The effect of inlet air velocity (5 to 25 m/s) and inlet solid particle feed rate of (0.2 to 2.5 g/s) at different particle diameter (300 to 500 μm) on holdup mass and heat transfer rate in cyclone heat exchanger was studied at air inlet temperature of 473 K. Results show that holdup mass and heat transfer rate increase with increase in inlet air velocity and inlet solid particle feed rate. Influence of solid particle feed rate on holdup mass has more significance. Experimental setup was built for high efficiency cyclone. Good agreement was found between experimental and simulation pressure drop. Empirical correlation was derived for dimensionless holdup mass and Nusselt number based on CFD data by regression technique. Correlation predicts dimensional holdup mass with +5% to -8% errors of experimental data and Nusselt number with +9% to -3%.

FDTD simulations to assess the performance of CFMA-434 applicators for superficial hyperthermia.

Science.gov (United States)

Kok, H Petra; De Greef, Martijn; Correia, Davi; Vörding, Paul J Zum Vörde Sive; Van Stam, Gerard; Gelvich, Edward A; Bel, Arjan; Crezee, Johannes

2009-01-01

Contact flexible microstrip applicators (CFMA), operating at 434 MHz, are applied at the Academic Medical Center (AMC) for superficial hyperthermia (e.g. chest wall recurrences and melanoma). This paper investigates the performance of CFMA, evaluating the stability of the specific absorption rate (SAR) distribution, effective heating depth (EHD) and effective field size (EFS) under different conditions. Simulations were performed using finite differences and were compared to existing measurement data, performed using a rectangular phantom with a superficial fat-equivalent layer of 1 cm and filled with saline solution. The electrode plates of the applicators measure approximately 7 x 20, 29 x 21 and 20 x 29 cm(2). Bolus thickness varied between 1 and 2 cm. The impact of the presence of possible air layers between the rubber frame and the electrodes on the SAR distribution was investigated. The EHD was approximately 1.4 cm and the EFS ranged between approximately 60 and approximately 300 cm(2), depending on the applicator type. Both measurements and simulations showed a split-up of the SAR focus with a 2 cm water bolus. The extent and location of air layers has a strong influence on the shape and size of the iso-SAR contours with a value higher than 50%, but the impact on EFS and EHD is limited. Simulations, confirmed by measurements, showed that the presence of air between the rubber and the electrodes changes the iso-SAR contours, but the impact on the EFS and EHD is limited.

A reassessment of the deposition velocity in the prediction of the environmental transport of radioiodine from air to milk

International Nuclear Information System (INIS)

Hoffman, F.O.

1977-01-01

The environmental transport of radioiodine from air to milk under conditions of dry deposition is considered with especial reference to the misinterpretation of experimentally derived values of the deposition velocity of elemental iodine by previous workers which has resulted in an apparent underestimation of this value. It is suggested that published predictions of the milk-to-air ratio be adjusted to account for this apparent error. (U.K.)

Measurements of laminar burning velocities and flame stability analysis for dissociated methanol-air-diluent mixtures at elevated temperatures and pressures

Energy Technology Data Exchange (ETDEWEB)

Zhang, Xuan; Huang, Zuohua; Zhang, Zhiyuan; Zheng, Jianjun; Yu, Wu; Jiang, Deming [State Key Laboratory of Multiphase Flow in Power Engineering, Xi' an Jiaotong University, Xi' an 710049 (China)

2009-06-15

The laminar burning velocities and Markstein lengths for the dissociated methanol-air-diluent mixtures were measured at different equivalence ratios, initial temperatures and pressures, diluents (N{sub 2} and CO{sub 2}) and dilution ratios by using the spherically outward expanding flame. The influences of these parameters on the laminar burning velocity and Markstein length were analyzed. The results show that the laminar burning velocity of dissociated methanol-air mixture increases with an increase in initial temperature and decreases with an increase in initial pressure. The peak laminar burning velocity occurs at equivalence ratio of 1.8. The Markstein length decreases with an increase in initial temperature and initial pressure. Cellular flame structures are presented at early flame propagation stage with the decrease of equivalence ratio or dilution ratio. The transition positions can be observed in the curve of flame propagation speed to stretch rate, indicating the occurrence of cellular structure at flame fronts. Mixture diluents (N{sub 2} and CO{sub 2}) will decrease the laminar burning velocities of mixtures and increase the sensitivity of flame front to flame stretch rate. Markstein length increases with an increase in dilution ratio except for very lean mixture (equivalence ratio less than 0.8). CO{sub 2} dilution has a greater impact on laminar flame speed and flame front stability compared to N{sub 2}. It is also demonstrated that the normalized unstretched laminar burning velocity is only related to dilution ratio and is not influenced by equivalence ratio. (author)

Impact of Different H/D Ratio on Axial Gas Holdup Measured by Four-Tips Optical Fiber Probe in Slurry Bubble Column

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Yasser Imad Abdulaziz

2016-02-01

Full Text Available In wide range of chemical, petrochemical and energy processes, it is not possible to manage without slurry bubble column reactors. In this investigation, time average local gas holdup was recorded for three different height to diameter (H/D ratios 3, 4 and 5 in 18" diameter slurry bubble column. Air-water-glass beads system was used with superficial velocity up to 0.24 m/s. the gas holdup was measured using 4-tips optical fiber probe technique. The results show that the axial gas holdup increases almost linearly with the superficial gas velocity in 0.08 m/s and levels off with a further increase of velocity. A comparison of the present data with those reported for other slurry bubble column having diameters larger than 18" and H/D higher than 5 indicated that there is little effect of diameter on gas holdup. Also, local section-average gas holdups increase with increasing superficial gas velocity, while the effect of solid loading are less significant than that of superficial gas velocity.

The superficial ulnar artery: development and clinical significance Artéria ulnar superficial: desenvolvimento e relevância clínica

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Srinivasulu Reddy

2007-09-01

Full Text Available The principal arteries of the upper limb show a wide range of variation that is of considerable interest to orthopedic surgeons, plastic surgeons, radiologists and anatomists. We present here a case of superficial ulnar artery found during the routine dissection of right upper limb of a 50-year-old male cadaver. The superficial ulnar artery originated from the brachial artery, crossed the median nerve anteriorly and ran lateral to this nerve and the brachial artery. The superficial ulnar artery in the arm gave rise to a narrow muscular branch to the biceps brachii. At the elbow level the artery ran superficial to the bicipital aponeurosis where it was crossed by the median cubital vein. It then ran downward and medially superficial to the forearm flexor muscles, and then downward to enter the hand. At the palm, it formed the superficial and deep palmar arches together with the branches of the radial artery. The presence of a superficial ulnar artery is clinically important when raising forearm flaps in reconstructive surgery. The embryology and clinical significance of the variation are discussed.As principais artérias do membro superior apresentam uma ampla variação, que é relativamente importante a cirurgiões ortopédicos e plásticos, radiologistas e anatomistas.Apresentamosumcaso de artéria ulnar superficial encontrada durante dissecção de rotina de membro superior direito de um cadáver masculino de 50 anos de idade.Aartéria ulnar superficial originava-se da artéria braquial, cruzava o nervo mediano anteriormente e percorria lateralmente esse nervo e a artéria braquial. A artéria ulnar superficial no braço deu origem a um ramo muscular estreito do músculo bíceps braquial. Ao nível do cotovelo, a artéria percorria superficialmente a aponeurose bicipital, onde era cruzada pela veia cubital mediana. Percorria, então, em sentido descendente e medialmente superficial aos músculos flexores do antebraço, e então descendia para

Effect of flow velocity and temperature on ignition characteristics in laser ignition of natural gas and air mixtures

Science.gov (United States)

Griffiths, J.; Riley, M. J. W.; Borman, A.; Dowding, C.; Kirk, A.; Bickerton, R.

2015-03-01

Laser induced spark ignition offers the potential for greater reliability and consistency in ignition of lean air/fuel mixtures. This increased reliability is essential for the application of gas turbines as primary or secondary reserve energy sources in smart grid systems, enabling the integration of renewable energy sources whose output is prone to fluctuation over time. This work details a study into the effect of flow velocity and temperature on minimum ignition energies in laser-induced spark ignition in an atmospheric combustion test rig, representative of a sub 15 MW industrial gas turbine (Siemens Industrial Turbomachinery Ltd., Lincoln, UK). Determination of minimum ignition energies required for a range of temperatures and flow velocities is essential for establishing an operating window in which laser-induced spark ignition can operate under realistic, engine-like start conditions. Ignition of a natural gas and air mixture at atmospheric pressure was conducted using a laser ignition system utilizing a Q-switched Nd:YAG laser source operating at 532 nm wavelength and 4 ns pulse length. Analysis of the influence of flow velocity and temperature on ignition characteristics is presented in terms of required photon flux density, a useful parameter to consider during the development laser ignition systems.

Superficies de segundo orden

OpenAIRE

Salazar Salazar, Luis Álvaro

1987-01-01

Este trabajo se propone poner al alcance de estudiantes de primeros semestres de carreras de aplicación de la matemática, un algoritmo proporcionado por el álgebra lineal, para tratar con mas generalidad, agilidad y libertad unos objetos de la geometría analítica de no fácil manipulación por otros métodos y que se conocen como superficies de segundo orden o superficies cuádricas. En este orden de ideas, el autor considera importante que con este tratamiento se incluya este tema en una asignat...

Laminar burning velocity and Markstein length of nitrogen diluted natural gas/hydrogen/air mixtures at normal, reduced and elevated pressures

Energy Technology Data Exchange (ETDEWEB)

Miao, Haiyan [State Key Laboratory of Multiphase Flow in Power Engineering, School of Energy and Power Eng., Xi' an Jiaotong University (China); Institute of High Performance Computing, A-star (Singapore); Ji, Min; Jiao, Qi; Huang, Qian; Huang, Zuohua [State Key Laboratory of Multiphase Flow in Power Engineering, School of Energy and Power Eng., Xi' an Jiaotong University (China)

2009-04-15

Flame propagation of premixed nitrogen diluted natural gas/hydrogen/air mixtures was studied in a constant volume combustion bomb under various initial pressures. Laminar burning velocities and Markstein lengths were obtained for the diluted stoichiometric fuel/air mixtures with different hydrogen fractions and diluent ratios under various initial pressures. The results showed that both unstretched flame speed and unstretched burning velocity are reduced with the increase in initial pressure (except when the hydrogen fraction is 80%) as well as diluent ratio. The velocity reduction rate due to diluent addition is determined mainly by hydrogen fraction and diluent ratio, and the effect of initial pressure is negligible. Flame stability was studied by analyzing Markstein length. It was found that the increase of initial pressure and hydrogen fraction decreases flame stability and the flame tends to be more stable with the addition of diluent gas. Generally speaking, Markstein length of a fuel with low hydrogen fraction is more sensitive to the change of initial pressure than that of a one with high hydrogen fraction. (author)

Questions Students Ask: About Terminal Velocity.

Science.gov (United States)

Meyer, Earl R.; Nelson, Jim

1984-01-01

If a ball were given an initial velocity in excess of its terminal velocity, would the upward force of air resistance (a function of velocity) be greater than the downward force of gravity and thus push the ball back upwards? An answer to this question is provided. (JN)

Human preference and acceptance of increased air velocity to offset warm sensation at increased room temperatures

DEFF Research Database (Denmark)

Cattarin, Giulio; Simone, Angela; Olesen, Bjarne W.

. The present climatic chamber study examined energy performance and achievable thermal comfort of traditional and bladeless desk fans. Different effects of mechanical and simulated-natural airflow patterns were also investigated. 32 Scandinavians, performing office activities and wearing light clothes , were......Previous studies have demonstrated that in summertime increased air velocities can compensate for higher room temperatures to achieve comfortable conditions. In order to increase air movement, windows opening, ceiling or desk fans can be used at the expense of relatively low energy consumption...... exposed to a increased air movement generated by a personal desk fan. The subjects could continuously regulate the fans under three fixed environmental conditions (operative temperatures equal to 26 °C, 28 °C, or 30 °C, and same absolute humidity 12.2 g/m3). The experimental study showed that increased...

Positive and negative streamers in ambient air: measuring diameter, velocity and dissipated energy

International Nuclear Information System (INIS)

Briels, T M P; Kos, J; Van Veldhuizen, E M; Ebert, U; Winands, G J J

2008-01-01

Positive and negative streamers are studied in ambient air at 1 bar; they emerge from a needle electrode placed 40 mm above a planar electrode. The amplitudes of the applied voltage pulses range from 5 to 96 kV; most pulses have rise times of 30 ns or shorter. Diameters, velocities and energies of the streamers are measured. Two regimes are identified; a low voltage regime where only positive streamers appear and a high voltage regime where both positive and negative streamers exist. Below 5 kV, no streamers emerge. In the range from 5 to 40 kV, positive streamers form, while the negative discharges only form a glowing cloud at the electrode tip, but no streamers. For 5-20 kV, diameters and velocities of the positive streamers have the minimal values of d = 0.2 mm and v ∼ 10 5 m s -1 . For 20-40 kV, their diameters increase by a factor of 6 while the voltage increases only by a factor of 2. Above the transition value of 40 kV, streamers of both polarities form; they strongly resemble each other, though the positive ones propagate further; their diameters continue to increase with applied voltage. For 96 kV, positive streamers attain diameters of 3 mm and velocities of 4 x 10 6 m s -1 ; negative streamers are about 20% slower and thinner. An empirical fit formula for the relation between velocity v and diameter d is v = 0.5d 2 mm -1 ns -1 for both polarities. Streamers of both polarities dissipate energies of the order of several millijoules per streamer while crossing the gap.

Medida de distensibilidad en pulmones aislados de rata: demostración del efecto de la tensión superficial

OpenAIRE

Araya, Romina Elizabeth; De Francesco, Pablo Nicolás; Smaldini, Paola Lorena; Iarossi, M. B.; Lastra, María Laura; Pérez, Pablo Fernando; Rebolledo, Alejandro; Rinaldi, Gustavo

2016-01-01

Uno de los TP de nuestra Cátedra consiste en la medición de la distensibilidad de un pulmón aislado de rata. La interfase aire-líquido en la superficie alveolar determina la existencia de tensión superficial (TS) en el líquido, la cual disminuye la distensibilidad pulmonar (DP). Si bien el surfactante pulmonar disminuye la TS, ésta continúa siendo importante. Los métodos para medir la TS de un líquido suelen ser bastante dificultosos (Ej: balanza de torsión de Du Noüy). El objetivo de este...

HIGH VELOCITY THERMAL GUN FOR SURFACE PREPARATION AND TREATMENT

Directory of Open Access Journals (Sweden)

I.A. Gorlach

2012-01-01

Full Text Available Many surface preparation and treatment processes utilise compressed air to propel particles against surfaces in order to clean and treat them. The effectiveness of the processes depends on the velocity of the particles, which in turn depends on the pressure of the compressed air. This paper describes a thermal gun built on the principles of High Velocity Air Fuel (HVAF and High Velocity Oxy Fuel (HVOF processes. The designed apparatus can be used for abrasive blasting, coating of surfaces, cutting of rocks, removing rubber from mining equipment, cleaning of contaminations etc.

Horizontal Air-Water Flow Analysis with Wire Mesh Sensor

International Nuclear Information System (INIS)

De Salve, M; Monni, G; Panella, B

2012-01-01

A Wire Mesh Sensor, based on the measurement of the local instantaneous conductivity of the two-phase mixture, has been used to characterize the fluid dynamics of the gas–liquid interface in a horizontal pipe flow. Experiments with a pipe of a nominal diameter of 19.5 mm and total length of 6 m, have been performed with air/water mixtures, at ambient conditions. The flow quality ranges from 0.00016 to 0.22 and the superficial velocities range from 0.1 to 10.5 m/s for air and from 0.02 to 1.7 m/s for water; the flow pattern is stratified, slug/plug and annular. A sensor (WMS200) with an inner diameter of 19.5 mm and a measuring matrix of 16×16 points equally distributed over the cross-section has been chosen for the measurements. From the analysis of the Wire Mesh Sensor digital signals the average and the local void fraction are evaluated and the flow patterns are identified with reference to space, time and flow rate boundary conditions.

VARIABILIDAD DE LA TEMPERATURA DE SUPERFICIES EN EL NW DE LA PROVINCIA DE NEUQUÉN A PARTIR DE INFORMCIÓN SATELITAL.

Directory of Open Access Journals (Sweden)

Marisa G. Cogliati

2008-12-01

Full Text Available La complejidad del terreno y la falta de datos meteorológicos siguiendo el gradiente altitudinal obliga a la exploración de nuevos métodos o esquemas entre los que se encuentra el análisis por medio de modelos o imágenes satelitales. El presente trabajo pretende describir el marco de información con el que se cuenta en el NW neuquino y la introducción de análisis espacial de distribución de la temperatura de superficie a partir de imágenes NOAA- AVHRR con miras a la inclusión futura de nuevos esquemas de estudio. La temperatura del aire presenta gran variabilidad espacial, principalmente en los valores mínimos, una idea de esta distribución puede asociarse a la temperatura de superficie que es obtenida a partir del análisis de imágenes NOAA-AVHRR. Este trabajo presenta el análisis de situaciones particulares de la temperatura de superficie de la zona NW de la Provincia de Neuquén utilizando imágenes de satélites NOAA en alta resolución (AVHRR e imágenes LANDSAT de la región. La temperatura de superficie obtenida utilizando la información de los canales 4 y 5 del sensor AVHRR presenta la distribución espacial de la temperatura del suelo que pone en evidencia la complejidad del comportamiento, asociado al relieve. Se observa la dependencia de las isotermas con la altura, alcanzando los menores valores de temperatura de superficie en los picos. Esta metodología permitiría incorporar información cuya escala consideraría con mayor detalle que en escala sinóptica de la temperatura de superficie de píxeles de aproximadamente 1 km2. El análisis posterior de una mayor cantidad de situaciones, permitiría realizar mapas estacionales de temperatura de superficie en una escala que no es posible obtener con el instrumental que se encuentra instalado en este momento, pudiendo asociarse posteriormente al comportamiento de la temperatura del aire.

An Experimental Measurement on Laminar Burning Velocities and Markstein Length of Iso-Butane-Air Mixtures at Ambient Conditions

Directory of Open Access Journals (Sweden)

Yousif Alaeldeen Altag

2016-01-01

Full Text Available In the present work, experimental investigation on laminar combustion of iso-butane-air mixtures was conducted in constant volume explosion vessel. The experiments were conducted at wide range of equivalence ratios ranging between Ф = 0.6 and 1.4 and atmospheric pressure of 0.1 MPa and ambient temperature of 303K. Using spherically expanding flame method, flame parameters including stretched, unstretched flame propagation speeds, laminar burning velocities and Markstein length were calculated. For laminar burning velocities the method of error bars of 95% confidence level was applied. In addition, values of Markstein lengths were measured in wide range of equivalence ratios to study the influence of stretch rate on flame instability and burning velocity. It was found that the stretched flame speed and laminar burning velocities increased with equivalence ratios and the peak value was obtained at equivalence ratio of Ф = 1.1. The Markstein length decreased with the increases in equivalence ratios, which indicates that the diffusion thermal flame instability increased at high equivalence ratios in richer mixture side. However, the total deviations in the laminar burning velocities have discrepancies of 1.2-2.9% for all investigated mixtures.

Positive and negative streamers in ambient air: measuring diameter, velocity and dissipated energy

Energy Technology Data Exchange (ETDEWEB)

Briels, T M P; Kos, J; Van Veldhuizen, E M; Ebert, U [Department of Applied Physics, Technische Universiteit Eindhoven, PO Box 513, 5600 MB Eindhoven (Netherlands); Winands, G J J [Department of Electrical Engineering, Technische Universiteit Eindhoven, PO Box 513, 5600 MB Eindhoven (Netherlands)], E-mail: e.m.v.veldhuizen@tue.nl, E-mail: ebert@cwi.nl

2008-12-07

Positive and negative streamers are studied in ambient air at 1 bar; they emerge from a needle electrode placed 40 mm above a planar electrode. The amplitudes of the applied voltage pulses range from 5 to 96 kV; most pulses have rise times of 30 ns or shorter. Diameters, velocities and energies of the streamers are measured. Two regimes are identified; a low voltage regime where only positive streamers appear and a high voltage regime where both positive and negative streamers exist. Below 5 kV, no streamers emerge. In the range from 5 to 40 kV, positive streamers form, while the negative discharges only form a glowing cloud at the electrode tip, but no streamers. For 5-20 kV, diameters and velocities of the positive streamers have the minimal values of d = 0.2 mm and v {approx} 10{sup 5} m s{sup -1}. For 20-40 kV, their diameters increase by a factor of 6 while the voltage increases only by a factor of 2. Above the transition value of 40 kV, streamers of both polarities form; they strongly resemble each other, though the positive ones propagate further; their diameters continue to increase with applied voltage. For 96 kV, positive streamers attain diameters of 3 mm and velocities of 4 x 10{sup 6} m s{sup -1}; negative streamers are about 20% slower and thinner. An empirical fit formula for the relation between velocity v and diameter d is v = 0.5d{sup 2} mm{sup -1} ns{sup -1} for both polarities. Streamers of both polarities dissipate energies of the order of several millijoules per streamer while crossing the gap.

Velocity measurements and identification of the flow pattern of vertical air-water flows with light-beam detectors

International Nuclear Information System (INIS)

Luebbesmeyer, D.; Leoni, B.

1980-07-01

A new detector for measuring fluid velocities in two-phase flows by means of Noise-Analysis (especially Transient-Cross-Correlation-technique) has been developed. The detector utilizes a light-beam which is modulated by changes in the transparency of the two-phase flow. The results of nine measurements for different flow-regimes of vertical air/water-flows are shown. A main topic of these investigations was to answer the question if it is possible to identify the flow-pattern by looking at the shape of different 'Noise-Analytical-functions' (like APSD, CPSD, CCF etc.). The results prove that light-beam sensors are good detectors for fluid-velocity measurements in different flow regimes and in a wide range of fluid velocities starting with values of about 0.08 m/s up to values of 40 m/s. With respect to flow-pattern identification only the time-signals and the shape of the cross-power-density-function (CPSD) seem to be useful. (Auth.)

Application and verification of cold air velocity technique for solving tube ash erosion problem in PC boilers

Energy Technology Data Exchange (ETDEWEB)

Yoo, Kisoo; Jeong, Kwon Seok [Korea Southern Power Corporation, Gimhae (Korea, Republic of)

2012-06-15

Fly ash erosion is a leading cause of boiler tube failure in PC boilers. Therefore, shields or baffle plates are installed in specific areas to mitigate fly ash erosion and prevent boiler tube failure. However, the tube failure problems caused by fly ash erosion cannot be eliminated with this solution alone, because each PC boiler has a different flue gas flow pattern and erosion can become severe in unexpected zones. This problem is caused by an asymmetric internal flow velocity and local growth of the flue gas velocity. For these reasons, clearly defining the flow pattern in PC boilers is important for solving the problem of tube failure caused by fly ash erosion. For this purpose, the cold air velocity technique (CAVT) can be applied to the fly ash erosion problem. In this study, CAVT was carried out on the Hadong 2 PC boiler and the feasibility of application of CAVT to conventional PC boilers was validated.

Application and verification of cold air velocity technique for solving tube ash erosion problem in PC boilers

International Nuclear Information System (INIS)

Yoo, Kisoo; Jeong, Kwon Seok

2012-01-01

Fly ash erosion is a leading cause of boiler tube failure in PC boilers. Therefore, shields or baffle plates are installed in specific areas to mitigate fly ash erosion and prevent boiler tube failure. However, the tube failure problems caused by fly ash erosion cannot be eliminated with this solution alone, because each PC boiler has a different flue gas flow pattern and erosion can become severe in unexpected zones. This problem is caused by an asymmetric internal flow velocity and local growth of the flue gas velocity. For these reasons, clearly defining the flow pattern in PC boilers is important for solving the problem of tube failure caused by fly ash erosion. For this purpose, the cold air velocity technique (CAVT) can be applied to the fly ash erosion problem. In this study, CAVT was carried out on the Hadong 2 PC boiler and the feasibility of application of CAVT to conventional PC boilers was validated

Local liquid velocity measurement in trickle bed reactors (TBRs) using the x-ray digital industrial radiography (DIR) technique

Science.gov (United States)

Anuar Mohd Salleh, Khairul; Lee, Hyoung Koo; Al-Dahhan, Muthanna H.

2014-01-01

This work describes the development of a new technique to measure local liquid velocity (VLL) for multiphase flows in trickle bed reactors (TBRs) (gas-liquid-solid system). In the studied TBR, the liquid phase is represented by water, gas by air and 3 mm expanded polystyrene beads as the solid packing. Three different superficial liquid velocities (VSL) and a constant superficial gas velocity (VSG) were used in the packed bed with an internal diameter of 4.25 cm. While the liquid is moving into the packed bed, tracking particles of 106-125 μm diameter (16.45% difference) are injected. The movement of the tracking particles is monitored and digitally recorded by a complementary metal-oxide-semiconductor detector. In this experiment, x-rays were used as the radiation source. Four replications were made with fresh packing. Comparable observations can be found from other published techniques (i.e. magnetic resonance imaging). Results from this study indicate that, at VSL = 0.13 cm s-1, the measured VLL can reach up to 51 times that of its VSL, while for VSL = 0.27 cm s-1, the measured VLL reached up to 35 times higher than the VSL and for VSL = 0.39 cm s-1, the VLL reached up to 39.8 times higher than its VSL. Through statistical analysis, the implementation of such a method is found to be reproducible throughout the experiments. The mean per cent difference in the measured VLL was 10% and 5% for lower implemented VSL of 0.13 and 0.27 cm s-1, respectively. At higher VSL (0.39 cm s-1), the particle tracer was greatly distributed and carried away by the high liquid flow rate. The variance or the range of the measured VLL does not vary for all replications in every VSL, which confirms the reproducibility of the experimental measurements, regardless of the VSL.

Development of evaluation method for hydraulic behavior in Venturi scrubber for filtered venting

International Nuclear Information System (INIS)

Horiguchi, Naoki; Nakao, Yasuhiro; Kaneko, Akiko; Abe, Yutaka; Yoshida, Hiroyuki

2016-01-01

Filtered venting systems have been installed to restart Nuclear Power Plants in Japan after Fukushima Daiichi Nuclear Disaster. Venturi scrubber is main component of one of the systems. To evaluate decontamination performance of the Venturi scrubber for filtered venting, mechanistic evaluation method for hydrodynamic behavior is important. In this paper, our objective is to develop the method. As approaches, we conducted experimental observation under adiabatic (air-water) condition, developed a numerical simulation code with one-dimensional two-fluid model and made verification and validation by comparison between these results in terms of superficial gas, static pressure, superficial liquid velocity, droplet ratio and droplet diameter in Venturi scrubber. As results, we observed the hydrodynamic behavior, developed the code and confirmed that it has capability to evaluate the parameters with following accuracy, superficial gas velocity with +30%, static pressure in throat part with +-10%, superficial liquid velocity with +-80%, droplet diameter with +-30% and droplet ratio with -50%. (author)

Imaging of the most frequent superficial soft-tissue sarcomas

International Nuclear Information System (INIS)

Morel, Melanie; Taieb, Sophie; Ceugnart, Luc; Penel, Nicolas; Mortier, Laurent; Vanseymortier, Luc; Robin, Y.M.; Gosset, Pierre; Cotten, Anne

2011-01-01

Superficial soft-tissue sarcomas are malignant mesenchymal tumors located within the cutaneous and/or subcutaneous layers. Most superficial soft-tissue sarcomas are low-grade tumors; yet, the risk of local recurrence is high, and initial wide surgery is the main prognostic factor. Some of these superficial sarcomas may grow, following an infiltrative pattern, and their real extent may be underestimated clinically. Imaging techniques are useful to determine precisely the real margins of the tumor, especially in cases of clinically doubtful or recurrent or large superficial lesions. Imaging tools enable one to determine the relationship with the superficial fascia separating the subcutaneous layer from the underlying muscle. In our institution ultrasonographic examination is followed by magnetic resonance (MR) imaging when the size of the lesion exceeds 3-5 cm. Imaging assessment is performed prior to biopsy, enabling optimal surgical management. Imaging features of the main superficial sarcomas are detailed in the following article, according to their major locations: those arising in the epidermis and/or dermis, which are most often diagnosed by dermatologists, and the subcutaneous sarcomas. (orig.)

Imaging of the most frequent superficial soft-tissue sarcomas

Energy Technology Data Exchange (ETDEWEB)

Morel, Melanie; Taieb, Sophie; Ceugnart, Luc [Centre Oscar Lambret, Department of Radiology, Lille (France); Penel, Nicolas [Centre Oscar Lambret, Department of Oncology, Lille (France); Mortier, Laurent [Centre Hospitalier Universitaire de Lille, Department of Dermatology, Hopital Claude Huriez, Lille (France); Vanseymortier, Luc [Centre Oscar Lambret, Department of Surgery, Lille (France); Robin, Y.M. [Centre Oscar Lambret, Departement of Pathology, Lille (France); Gosset, Pierre [Groupement Hospitalier de l' Institut Catholique-Faculte Libre de Medecine de Lille, Department of Pathology, Hopital Saint-Philibert, Lomme (France); Cotten, Anne [Centre Hospitalier Universitaire de Lille, Department of Musculoskeletal Radiology, Centre Hopital Roger Salengro, Lille (France)

2011-03-15

Superficial soft-tissue sarcomas are malignant mesenchymal tumors located within the cutaneous and/or subcutaneous layers. Most superficial soft-tissue sarcomas are low-grade tumors; yet, the risk of local recurrence is high, and initial wide surgery is the main prognostic factor. Some of these superficial sarcomas may grow, following an infiltrative pattern, and their real extent may be underestimated clinically. Imaging techniques are useful to determine precisely the real margins of the tumor, especially in cases of clinically doubtful or recurrent or large superficial lesions. Imaging tools enable one to determine the relationship with the superficial fascia separating the subcutaneous layer from the underlying muscle. In our institution ultrasonographic examination is followed by magnetic resonance (MR) imaging when the size of the lesion exceeds 3-5 cm. Imaging assessment is performed prior to biopsy, enabling optimal surgical management. Imaging features of the main superficial sarcomas are detailed in the following article, according to their major locations: those arising in the epidermis and/or dermis, which are most often diagnosed by dermatologists, and the subcutaneous sarcomas. (orig.)

Air movement and perceived air quality

DEFF Research Database (Denmark)

Melikov, Arsen Krikor; Kaczmarczyk, J.

2012-01-01

The impact of air movement on perceived air quality (PAQ) and sick building syndrome (SBS) symptoms was studied. In total, 124 human subjects participated in four series of experiments performed in climate chambers at different combinations of room air temperature (20, 23, 26 and 28 °C), relative...... and the humidity of the room air. At a low humidity level of 30% an increased velocity could compensate for the decrease in perceived air quality due to an elevated temperature ranging from 20 °C to 26 °C. In a room with 26 °C, increased air movement was also able to compensate for an increase in humidity from 30...... humidity (30, 40 and 70%) and pollution level (low and high). Most of the experiments were performed with and without facially applied airflow at elevated velocity. The importance of the use of recirculated room air and clean, cool and dry outdoor air was studied. The exposures ranged from 60. min to 235...

An Investigation on the Efficiency of Air Purification Using a Biofilter with Activated Bed of Different Origin

Directory of Open Access Journals (Sweden)

Zagorskis Alvydas

2014-12-01

Full Text Available Recent studies in the area of biological air treatment in filters have addressed fundamental key issues, such as a biofilter bed of different origin composed of natural zeolite granules, foam cubes and wood chips. When foam and zeolite are mixed with wood chips to remove volatile organic compounds from the air, not only biological but also adsorption air purification methods are accomplished. The use of complex purification technologies helps to improve the efficiency of a filter as well as the bed service life of the filter bed. Investigations revealed that microorganisms prevailing in biological purification, can also reproduce themselves in biofilter beds of inorganic and synthetic origin composed of natural zeolite and foam. By cultivating associations of spontaneous microorganisms in the filter bed the dependencies of the purification efficiency of filter on the origin, concentration and filtration time of injected pollutants were determined. The highest purification efficiency was obtained when air polluted with acetone vapour was supplied to the equipment at 0.1 m/s of superficial gas velocity. When cleaning air from volatile organic compounds (acetone, toluene and butanol, under the initial pollutant concentration of ~100 mg/m3, the filter efficiency reached 95 %.

Superficial dose evaluation of four dose calculation algorithms

Science.gov (United States)

Cao, Ying; Yang, Xiaoyu; Yang, Zhen; Qiu, Xiaoping; Lv, Zhiping; Lei, Mingjun; Liu, Gui; Zhang, Zijian; Hu, Yongmei

2017-08-01

Accurate superficial dose calculation is of major importance because of the skin toxicity in radiotherapy, especially within the initial 2 mm depth being considered more clinically relevant. The aim of this study is to evaluate superficial dose calculation accuracy of four commonly used algorithms in commercially available treatment planning systems (TPS) by Monte Carlo (MC) simulation and film measurements. The superficial dose in a simple geometrical phantom with size of 30 cm×30 cm×30 cm was calculated by PBC (Pencil Beam Convolution), AAA (Analytical Anisotropic Algorithm), AXB (Acuros XB) in Eclipse system and CCC (Collapsed Cone Convolution) in Raystation system under the conditions of source to surface distance (SSD) of 100 cm and field size (FS) of 10×10 cm2. EGSnrc (BEAMnrc/DOSXYZnrc) program was performed to simulate the central axis dose distribution of Varian Trilogy accelerator, combined with measurements of superficial dose distribution by an extrapolation method of multilayer radiochromic films, to estimate the dose calculation accuracy of four algorithms in the superficial region which was recommended in detail by the ICRU (International Commission on Radiation Units and Measurement) and the ICRP (International Commission on Radiological Protection). In superficial region, good agreement was achieved between MC simulation and film extrapolation method, with the mean differences less than 1%, 2% and 5% for 0°, 30° and 60°, respectively. The relative skin dose errors were 0.84%, 1.88% and 3.90%; the mean dose discrepancies (0°, 30° and 60°) between each of four algorithms and MC simulation were (2.41±1.55%, 3.11±2.40%, and 1.53±1.05%), (3.09±3.00%, 3.10±3.01%, and 3.77±3.59%), (3.16±1.50%, 8.70±2.84%, and 18.20±4.10%) and (14.45±4.66%, 10.74±4.54%, and 3.34±3.26%) for AXB, CCC, AAA and PBC respectively. Monte Carlo simulation verified the feasibility of the superficial dose measurements by multilayer Gafchromic films. And the rank

Evaluation of the effect of media velocity on filter efficiency and most penetrating particle size of nuclear grade high-efficiency particulate air filters.

Science.gov (United States)

Alderman, Steven L; Parsons, Michael S; Hogancamp, Kristina U; Waggoner, Charles A

2008-11-01

High-efficiency particulate air (HEPA) filters are widely used to control particulate matter emissions from processes that involve management or treatment of radioactive materials. Section FC of the American Society of Mechanical Engineers AG-1 Code on Nuclear Air and Gas Treatment currently restricts media velocity to a maximum of 2.5 cm/sec in any application where this standard is invoked. There is some desire to eliminate or increase this media velocity limit. A concern is that increasing media velocity will result in higher emissions of ultrafine particles; thus, it is unlikely that higher media velocities will be allowed without data to demonstrate the effect of media velocity on removal of ultrafine particles. In this study, the performance of nuclear grade HEPA filters, with respect to filter efficiency and most penetrating particle size, was evaluated as a function of media velocity. Deep-pleat nuclear grade HEPA filters (31 cm x 31 cm x 29 cm) were evaluated at media velocities ranging from 2.0 to 4.5 cm/sec using a potassium chloride aerosol challenge having a particle size distribution centered near the HEPA filter most penetrating particle size. Filters were challenged under two distinct mass loading rate regimes through the use of or exclusion of a 3 microm aerodynamic diameter cut point cyclone. Filter efficiency and most penetrating particle size measurements were made throughout the duration of filter testing. Filter efficiency measured at the onset of aerosol challenge was noted to decrease with increasing media velocity, with values ranging from 99.999 to 99.977%. The filter most penetrating particle size recorded at the onset of testing was noted to decrease slightly as media velocity was increased and was typically in the range of 110-130 nm. Although additional testing is needed, these findings indicate that filters operating at media velocities up to 4.5 cm/sec will meet or exceed current filter efficiency requirements. Additionally

Flow Regimes of Air-Water Counterflow Through Cross Corrugated Parallel Plates

Energy Technology Data Exchange (ETDEWEB)

de Almeida, V.F.

2000-06-07

Heretofore unknown flow regimes of air-water counterflow through a pair of transparent vertical parallel cross corrugated plates were observed via high-speed video. Air flows upward driven by pressure gradient and water, downward driven by gravity. The crimp geometry of the corrugations was drawn from typical corrugated sheets used as filling material in modern structured packed towers. Four regimes were featured, namely, rivulet, bicontinuous, flooding fronts, and flooding waves. It is conceivable that the regimes observed might constitute the basis for understanding how gas and liquid phases contend for available space in the interstices of structured packings in packed towers. Flow regime transitions were expressed in terms of liquid load (liquid superficial velocity) and gas flow factor parameters commonly used in pressure drop and capacity curves. We have carefully examined the range of parameters equivalent to the ill-understood high-liquid-flow operation in packed towers. More importantly, our findings should prove valuable in validating improved first-principles modeling of gas-liquid flows in these industrially important devices.

Mean droplet size and local velocity in horizontal isothermal free jets of air and water, respectively, viscous liquid in quiescent ambient air

Energy Technology Data Exchange (ETDEWEB)

Al Rabadi, S.; Friedel, L. [Fluid Mechanics Institute, Technical University of Hamburg-Harburg (Germany); Al Salaymeh, A. [Mechanical Engineering Department, University of Jordan (Jordan)

2007-01-15

Measurements using two-dimensional Phase Doppler Anemometry as well as high speed cinematography in free jets at several nozzle exit pressures and mass flow rates, show that the Sauter mean droplet diameter decreases with increasing air and liquid-phase mass flow ratio due to the increase of the air stream impact on the liquid phase. This leads to substantial liquid fragmentation, respectively primary droplet breakup, and hence, satellite droplet formation with small sizes. This trend is also significant in the case of a liquid viscosity higher than that of water. The increased liquid viscosity stabilizes the droplet formation and breakup by reducing the rate of surface perturbations and consequently droplet distortions, ultimately also leading, in total, to the formation of smaller droplets. The droplet velocity decreases with the nozzle downstream distance, basically due to the continual air entrainment and due to the collisions between the droplets. The droplet collisions may induce further liquid fragmentation and, hence, formation of a number of relatively smaller droplets respectively secondary breakup, or may induce agglomeration to comparatively larger liquid fragments that may rain out of the free jet. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

Comparison between PIII superficial treatment and ceramic coating in creep test of Ti-6Al-4V alloy

International Nuclear Information System (INIS)

Reis, D.A.P.; Moura Neto, C.; Silva, M.M.; Ueda, M.; Oliveira, V.S.; Couto, A.A.

2009-01-01

The objective of this work was evaluating the creep resistance of the Ti-6Al-4V alloy with superficial treatment of PIII superficial treatment and ceramic coating in creep test of Ti-6Al-4V alloy. It was used Ti-6Al-4V alloy as cylindrical bars under forged and annealing of 190 deg C by 6 hours condition and cooled by air. The Ti-6Al-4V alloy after the superficial treatment of PIII and ceramic coating was submitted to creep tests at 600°C and 250 and 319 MPa under constant load mode. In the PIII treatment the samples was put in a vacuum reactor (76 x 10 -3 Pa) and implanted by nitrogen ions in time intervals between 15 and 120 minutes. Yttria (8 wt.%) stabilized zirconia (YSZ) with a CoNiCrAlY bond coat was atmospherically plasma sprayed on Ti-6Al-4V substrates by Sulzer Metco Type 9 MB. The obtained results suggest the ceramic coating on Ti-6Al-4V alloy improved its creep resistance. (author)

Superficial deposits in northeast flank of Sierras Australes (Provincia de Buenos Aires, Republica Argentina)

International Nuclear Information System (INIS)

Gentile, R.; Fucks, E.; De Francesco, F.

2004-01-01

Pleistocene and Holocene superficial deposits, which have been recognized in an area of 1500 km2 in the northeast flank of Sierras Australes, are characterized. In divide they are underlain by silts and siltstone which are called Sediments Pampeanas. There, a lower sequence, consisting mainly of aeolian sediments (loess) with scarce fluvial deposits and diamictons, was recognized. In some places an upper sequence that is product of aeolian and anthropogenic activity, was also recognized. In the valley sequences, the loess deposits can not only be underlain by fluvial sediments but can also overlain them. The more recent fluvial deposits which have eroded loess sequences are of the post conquest age [es

Scanning electron microscopy of superficial white onychomycosis*

Science.gov (United States)

de Almeida Jr., Hiram Larangeira; Boabaid, Roberta Oliveira; Timm, Vitor; Silva, Ricardo Marques e; de Castro, Luis Antonio Suita

2015-01-01

Superficial white onychomycosis is characterized by opaque, friable, whitish superficial spots on the nail plate. We examined an affected halux nail of a 20-year-old male patient with scanning electron microscopy. The mycological examination isolated Trichophyton mentagrophytes. Abundant hyphae with the formation of arthrospores were found on the nail's surface, forming small fungal colonies. These findings showed the great capacity for dissemination of this form of onychomycosis. PMID:26560225

Effect of wind waves on air-sea gas exchange: proposal of an overall CO2 transfer velocity formula as a function of breaking-wave parameter

International Nuclear Information System (INIS)

Zhao, D.; Suzuki, Y.; Komori, S.

2003-01-01

A new formula for gas transfer velocity as a function of the breaking-wave parameter is proposed based on correlating gas transfer with whitecap coverage. The new formula for gas transfer across an air-sea interface depends not only on wind speed but also on wind-wave state. At the same wind speed, a higher gas transfer velocity will be obtained for a more developed wind-sea, which is represented by a smaller spectral peak frequency of wind waves. We suggest that the large uncertainties in the traditional relationship of gas transfer velocity with wind speed be ascribed to the neglect of the effect of wind waves. The breaking-wave parameter can be regarded as a Reynolds number that characterizes the intensity of turbulence associated with wind waves in the downward-bursting boundary layer (DBBL). DBBL provides an effective way to exchange gas across the air-sea interface, which might be related to the surface renewal

Clinico Mycological Study of Superficial Mycoses

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Rachana J. Magdum

2016-10-01

Full Text Available Background: Generally it is well established fact that geographical distribution of the fungi may change from time to time; hence this study was planned. Aim and Objectives: To analyze the prevalence of superficial mycoses, its clinical presentation and species identification of the fungal isolates responsible for the disease. Material and Methods: A total 125 clinically diagnosed cases of superficial mycoses visiting Dermatology and Venereology outpatient department of Bharati Hospital, Sangli, for a period of one year were included in the study. Specimens like skin scrapping, nail clipping, hair were collected and subjected to KOH mount and culture. Identification of species was done by macroscopic examination of culture, tease mount and other physiological tests including Urease test, Hair perforation tests and Germ tube test. Results: Superficial mycosis was more common in the age group of 21-30 years (28% and in males (60.8%. The infection was more common in students (29.6%. Tinea corporis (42.4% was the commonest clinical type followed by tinea cruris (22.4%. 61.6% cases were positive by direct microscopy and 60.8% cases showed culture positive. Out of 125 samples, dermatophytes were grown in 63 cases (82.89% followed by non dermatophytic moulds in 10 cases (13.16% and Candida albicans in 3 cases (3.95%. The most common isolate among dermtophytosis was T. rubrum (46.05% followed by T. mentagrophyte (25%. Conclusion: It was concluded that along with dermatophytes, non dermatophytic moulds are also important to cause of superficial mycoses

Superficial herpes simplex virus wound infection following lung transplantation.

Science.gov (United States)

Karolak, Wojtek; Wojarski, Jacek; Zegleń, Sławomir; Ochman, Marek; Urlik, Maciej; Hudzik, Bartosz; Wozniak-Grygiel, Elzbieta; Maruszewski, Marcin

2017-08-01

Surgical site infections (SSIs) are infections of tissues, organs, or spaces exposed by surgeons during performance of an invasive procedure. SSIs are classified into superficial, which are limited to skin and subcutaneous tissues, and deep. The incidence of deep SSIs in lung transplant (LTx) patients is estimated at 5%. No reports have been published as to the incidence of superficial SSIs specifically in LTx patients. Common sense would dictate that the majority of superficial SSIs would be bacterial. Uncommonly, fungal SSIs may occur, and we believe that no reports exist as to the incidence of viral wound infections in LTx patients, or in any solid organ transplant patients. We report a de novo superficial wound infection with herpes simplex virus following lung transplantation, its possible source, treatment, and resolution. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Local liquid velocity measurement in trickle bed reactors (TBRs) using the x-ray digital industrial radiography (DIR) technique

International Nuclear Information System (INIS)

Salleh, Khairul Anuar Mohd; Lee, Hyoung Koo; Al-Dahhan, Muthanna H

2014-01-01

This work describes the development of a new technique to measure local liquid velocity (V LL ) for multiphase flows in trickle bed reactors (TBRs) (gas–liquid–solid system). In the studied TBR, the liquid phase is represented by water, gas by air and 3 mm expanded polystyrene beads as the solid packing. Three different superficial liquid velocities (V SL ) and a constant superficial gas velocity (V SG ) were used in the packed bed with an internal diameter of 4.25 cm. While the liquid is moving into the packed bed, tracking particles of 106–125 μm diameter (16.45% difference) are injected. The movement of the tracking particles is monitored and digitally recorded by a complementary metal–oxide–semiconductor detector. In this experiment, x-rays were used as the radiation source. Four replications were made with fresh packing. Comparable observations can be found from other published techniques (i.e. magnetic resonance imaging). Results from this study indicate that, at V SL = 0.13 cm s −1 , the measured V LL  can reach up to 51 times that of its V SL , while for V SL = 0.27 cm s −1 , the measured V LL  reached up to 35 times higher than the V SL and for V SL = 0.39 cm s −1 , the V LL  reached up to 39.8 times higher than its V SL . Through statistical analysis, the implementation of such a method is found to be reproducible throughout the experiments. The mean per cent difference in the measured V LL was 10% and 5% for lower implemented V SL   of 0.13 and 0.27 cm s −1 , respectively. At higher V SL  (0.39 cm s −1 ), the particle tracer was greatly distributed and carried away by the high liquid flow rate. The variance or the range of the measured V LL  does not vary for all replications in every V SL , which confirms the reproducibility of the experimental measurements, regardless of the V SL . (paper)

Impact of individually controlled facially applied air movement on perceived air quality at high humidity

Energy Technology Data Exchange (ETDEWEB)

Skwarczynski, M.A. [Faculty of Environmental Engineering, Institute of Environmental Protection Engineering, Department of Indoor Environment Engineering, Lublin University of Technology, Lublin (Poland); International Centre for Indoor Environment and Energy, Department of Civil Engineering, Technical University of Denmark, Copenhagen (Denmark); Melikov, A.K.; Lyubenova, V. [International Centre for Indoor Environment and Energy, Department of Civil Engineering, Technical University of Denmark, Copenhagen (Denmark); Kaczmarczyk, J. [Faculty of Energy and Environmental Engineering, Department of Heating, Ventilation and Dust Removal Technology, Silesian University of Technology, Gliwice (Poland)

2010-10-15

The effect of facially applied air movement on perceived air quality (PAQ) at high humidity was studied. Thirty subjects (21 males and 9 females) participated in three, 3-h experiments performed in a climate chamber. The experimental conditions covered three combinations of relative humidity and local air velocity under a constant air temperature of 26 C, namely: 70% relative humidity without air movement, 30% relative humidity without air movement and 70% relative humidity with air movement under isothermal conditions. Personalized ventilation was used to supply room air from the front toward the upper part of the body (upper chest, head). The subjects could control the flow rate (velocity) of the supplied air in the vicinity of their bodies. The results indicate an airflow with elevated velocity applied to the face significantly improves the acceptability of the air quality at the room air temperature of 26 C and relative humidity of 70%. (author)

Understanding the three-dimensional anatomy of the superficial lymphatics of the limbs.

Science.gov (United States)

Tourani, Saam S; Taylor, G Ian; Ashton, Mark W

2014-11-01

There are minimal data in the current literature regarding the depth of the superficial lymphatic collectors of the limbs in relation to the various subcutaneous tissue layers. Injection, microdissection, radiographic, and histologic studies of the superficial lymphatics and the subcutaneous tissues of 32 limbs from 15 human cadavers were performed. Five layers were consistently identified in the integument of all the upper and lower limb specimens: (1) skin, (2) subcutaneous fat, (3) superficial fascia, (4) loose areolar tissue, and (5) deep fascia. Layer 2 was further divided into superficial (2a) and deep (2c) compartments by a thin, transparent, horizontal septum (layer 2b). The main superficial veins and the superficial nerves coursed in layer 4. The lymphatic collectors were found at layer 2c and layer 4. The use of consistent nomenclature to describe the subcutaneous tissue layers facilitates a greater understanding and discussion of the anatomy. In lymphovenous anastomosis for the treatment of lymphedema, indocyanine green lymphography is an unreliable method for identification of the superficial collectors of the thigh. The medial proximal leg, the dorsum of the wrist over the anatomical snuffbox, and the volar proximal forearm provide suitable areas for locating superficial collectors with nearby matching size veins. In vertical medial thigh lift, choosing a dissection plane superficial to the great saphenous vein is unlikely to preserve the collectors of the ventromedial bundle.

Social network extraction based on Web: 1. Related superficial methods

Science.gov (United States)

Khairuddin Matyuso Nasution, Mahyuddin

2018-01-01

Often the nature of something affects methods to resolve the related issues about it. Likewise, methods to extract social networks from the Web, but involve the structured data types differently. This paper reveals several methods of social network extraction from the same sources that is Web: the basic superficial method, the underlying superficial method, the description superficial method, and the related superficial methods. In complexity we derive the inequalities between methods and so are their computations. In this case, we find that different results from the same tools make the difference from the more complex to the simpler: Extraction of social network by involving co-occurrence is more complex than using occurrences.

[Superficial venous thrombosis. A state of art].

Science.gov (United States)

Sándor, Tamás

2017-01-01

For a long time superficial thrombophlebitis has been thought to be a rather benign condition. Recently, when duplex ultrasound technique is used for the diagnosis more and more often, the disease is proved to be more dangerous than anticipated. Thrombosis propagates to the deep veins in 6-44% and pulmonary embolism was observed on the patients in 1,5-33%. We can calculate venous thromboembolic complications on every fourth patient. Diagnosis is clinical, but duplex ultrasound examination is mandatory, for estimation of the thrombus extent, for exclusion of the deep venous thrombosis and for follow up. Both legs should be checked with ultrasound, because simultaneous deep venous thrombosis can develop on the contralateral limb. Two different forms can be distinguished: superficial venous thrombosis with, or without varicose veins. In cases of spontaneous, non varicous form, especially when the process is migrating or recurrent, a careful clinical examination is necessery for exclusion of malignant diseases and thrombophilia. The treatment options are summarised on the basis of recent international consensus statements. The American and German guidelines are similar. Compression and mobilisation are cornerstones of the therapy. For a short segment thrombosis non steroidal antiinflammatory drugs are effective. For longer segments low molecular-weight heparins are preferred. Information on the effect of the novel oral anticoagulants for the therapy is lacking but they may appear to be effective in the future for this indication. When thrombus is close to the sapheno-femoral or sapheno-popliteal junction crossectomy (high ligation), or low molecular-weight heparin in therapeutic doses are indicated. The term superficial thrombophlebitis should be discouraged, because inflammation and infection is not the primary pathology. It should be called correctly superficial venous thrombosis in order to avoid the unnecessary administration of antibiotics and the misconception

Major Superficial White Matter Abnormalities in Huntington's Disease

Science.gov (United States)

Phillips, Owen R.; Joshi, Shantanu H.; Squitieri, Ferdinando; Sanchez-Castaneda, Cristina; Narr, Katherine; Shattuck, David W.; Caltagirone, Carlo; Sabatini, Umberto; Di Paola, Margherita

2016-01-01

Background: The late myelinating superficial white matter at the juncture of the cortical gray and white matter comprising the intracortical myelin and short-range association fibers has not received attention in Huntington's disease. It is an area of the brain that is late myelinating and is sensitive to both normal aging and neurodegenerative disease effects. Therefore, it may be sensitive to Huntington's disease processes. Methods: Structural MRI data from 25 Pre-symptomatic subjects, 24 Huntington's disease patients and 49 healthy controls was run through a cortical pattern-matching program. The surface corresponding to the white matter directly below the cortical gray matter was then extracted. Individual subject's Diffusion Tensor Imaging (DTI) data was aligned to their structural MRI data. Diffusivity values along the white matter surface were then sampled at each vertex point. DTI measures with high spatial resolution across the superficial white matter surface were then analyzed with the General Linear Model to test for the effects of disease. Results: There was an overall increase in the axial and radial diffusivity across much of the superficial white matter (p < 0.001) in Pre-symptomatic subjects compared to controls. In Huntington's disease patients increased diffusivity covered essentially the whole brain (p < 0.001). Changes are correlated with genotype (CAG repeat number) and disease burden (p < 0.001). Conclusions: This study showed broad abnormalities in superficial white matter even before symptoms are present in Huntington's disease. Since, the superficial white matter has a unique microstructure and function these abnormalities suggest it plays an important role in the disease. PMID:27242403

What factors control the superficial lava dome explosivity?

Science.gov (United States)

Boudon, Georges; Balcone-Boissard, Hélène; Villemant, Benoit; Morgan, Daniel J.

2015-04-01

Dome-forming eruption is a frequent eruptive style; lava domes result from intermittent, slow extrusion of viscous lava. Most dome-forming eruptions produce highly microcrystallized and highly- to almost totally-degassed magmas which have a low explosive potential. During lava dome growth, recurrent collapses of unstable parts are the main destructive process of the lava dome, generating concentrated pyroclastic density currents (C-PDC) channelized in valleys. These C-PDC have a high, but localized, damage potential that largely depends on the collapsed volume. Sometimes, a dilute ash cloud surge develops at the top of the concentrated flow with an increased destructive effect because it may overflow ridges and affect larger areas. In some cases, large lava dome collapses can induce a depressurization of the magma within the conduit, leading to vulcanian explosions. By contrast, violent, laterally directed, explosions may occur at the base of a growing lava dome: this activity generates dilute and turbulent, highly-destructive, pyroclastic density currents (D-PDC), with a high velocity and propagation poorly dependent on the topography. Numerous studies on lava dome behaviors exist, but the triggering of lava dome explosions is poorly understood. Here, seven dome-forming eruptions are investigated: in the Lesser Antilles arc: Montagne Pelée, Martinique (1902-1905, 1929-1932 and 650 y. BP eruptions), Soufrière Hills, Montserrat; in Guatemala, Santiaguito (1929 eruption); in La Chaîne des Puys, France (Puy de Dome and Puy Chopine eruptions). We propose a new model of superficial lava-dome explosivity based upon a textural and geochemical study (vesicularity, microcrystallinity, cristobalite distribution, residual water contents, crystal transit times) of clasts produced by these key eruptions. Superficial explosion of a growing lava dome may be promoted through porosity reduction caused by both vesicle flattening due to gas escape and syn-eruptive cristobalite

Evaluation of a Candidate Trace Contaminant Control Subsystem Architecture: The High Velocity, Low Aspect Ratio (HVLA) Adsorption Process

Science.gov (United States)

Kayatin, Matthew J.; Perry, Jay L.

2017-01-01

Traditional gas-phase trace contaminant control adsorption process flow is constrained as required to maintain high contaminant single-pass adsorption efficiency. Specifically, the bed superficial velocity is controlled to limit the adsorption mass-transfer zone length relative to the physical adsorption bed; this is aided by traditional high-aspect ratio bed design. Through operation in this manner, most contaminants, including those with relatively high potential energy are readily adsorbed. A consequence of this operational approach, however, is a limited available operational flow margin. By considering a paradigm shift in adsorption architecture design and operations, in which flows of high superficial velocity are treated by low-aspect ratio sorbent beds, the range of well-adsorbed contaminants becomes limited, but the process flow is increased such that contaminant leaks or emerging contaminants of interest may be effectively controlled. To this end, the high velocity, low aspect ratio (HVLA) adsorption process architecture was demonstrated against a trace contaminant load representative of the International Space Station atmosphere. Two HVLA concept packaging designs (linear flow and radial flow) were tested. The performance of each design was evaluated and compared against computer simulation. Utilizing the HVLA process, long and sustained control of heavy organic contaminants was demonstrated.

Velocity distribution measurement in wire-spaced fuel pin bundle

International Nuclear Information System (INIS)

Mizuta, Hiroshi; Ohtake, Toshihide; Uruwashi, Shinichi; Takahashi, Keiichi

1974-01-01

Flow distribution measurement was made in the subchannels of a pin bundle in air flow. The present paper is interim because the target of this work is the decision of temperature of the pin surface in contact with wire spacers. The wire-spaced fuel pin bundle used for the experiment consists of 37 simulated fuel pins of stainless steel tubes, 3000 mm in length and 31.6 mm in diameter, which are wound spirally with 6 mm stainless steel wire. The bundle is wrapped with a hexagonal tube, 3500 mm in length and 293 mm in flat-to-flat distance. The bundle is fixed with knock-bar at the entrance of air flow in the hexagonal tube. The pitch of pins in the bundle is 37.6 mm (P/D=1.19) and the wrapping pitch of wire is 1100 mm (H/D=34.8). A pair of arrow-type 5-hole Pitot tubes are used to measure the flow velocity and the direction of air flow in the pin bundle. The measurement of flow distribution was made with the conditions of air flow rate of 0.33 m 3 /sec, air temperature of 45 0 C, and average Reynolds number of 15100 (average air velocity of 20.6 m/sec.). It was found that circular flow existed in the down stream of wire spacers, that axial flow velocity was slower in the subchannels, which contained wire spacers, than in those not affected by the wire, and that the flow angle to the axial velocity at the boundary of subchannels was two thirds smaller than wire wrapping angle. (Tai, I.)

Superficial or deep implantation of motor nerve after denervation: an experimental study--superficial or deep implantation of motor nerve.

Science.gov (United States)

Askar, Ibrahím; Sabuncuoglu, Bízden Tavíl

2002-01-01

Neurorraphy, conventional nerve grafting technique, and artificial nerve conduits are not enough for repair in severe injuries of peripheral nerves, especially when there is separation of motor nerve from muscle tissue. In these nerve injuries, reinnervation is indicated for neurotization. The distal end of a peripheral nerve is divided into fascicles and implanted into the aneural zone of target muscle tissue. It is not known how deeply fascicles should be implanted into muscle tissue. A comparative study of superficial and deep implantation of separated motor nerve into muscle tissue is presented in the gastrocnemius muscle of rabbits. In this experimental study, 30 white New Zealand rabbits were used and divided into 3 groups of 10 rabbits each. In the first group (controls, group I), only surgical exposure of the gastrocnemius muscle and motor nerve (tibial nerve) was done without any injury to nerves. In the superficial implantation group (group II), tibial nerves were separated and divided into their own fascicles. These fascicles were implanted superficially into the lateral head of gastrocnemius muscle-aneural zone. In the deep implantation group (group III), the tibial nerves were separated and divided into their own fascicles. These fascicles were implanted around the center of the muscle mass, into the lateral head of the gastrocnemius muscle-aneural zone. Six months later, histopathological changes and functional recovery of the gastrocnemius muscle were investigated. Both experimental groups had less muscular weight than in the control group. It was found that functional recovery was achieved in both experimental groups, and was better in the superficial implantation group than the deep implantation group. EMG recordings revealed that polyphasic and late potentials were frequently seen in both experimental groups. Degeneration and regeneration of myofibrils were observed in both experimental groups. New motor end-plates were formed in a scattered

The Prescribed Velocity Method

DEFF Research Database (Denmark)

Nielsen, Peter Vilhelm

The- velocity level in a room ventilated by jet ventilation is strongly influenced by the supply conditions. The momentum flow in the supply jets controls the air movement in the room and, therefore, it is very important that the inlet conditions and the numerical method can generate a satisfactory...

Application of TiC reinforced Fe-based coatings by means of High Velocity Air Fuel Spraying

Science.gov (United States)

Bobzin, K.; Öte, M.; Knoch, M. A.; Liao, X.; Sommer, J.

2017-03-01

In the field of hydraulic applications, different development trends can cause problems for coatings currently used as wear and corrosion protection for piston rods. Aqueous hydraulic fluids and rising raw material prices necessitate the search for alternatives to conventional coatings like galvanic hard chrome or High Velocity Oxygen Fuel (HVOF)-sprayed WC/Co coatings. In a previous study, Fe/TiC coatings sprayed by a HVOF-process, were identified to be promising coating systems for wear and corrosion protection in hydraulic systems. In this feasibility study, the novel High Velocity Air Fuel (HVAF)-process, a modification of the HVOF-process, is investigated using the same feedstock material, which means the powder is not optimized for the HVAF-process. The asserted benefits of the HVAF-process are higher particle velocities and lower process temperatures, which can result in a lower porosity and oxidation of the coating. Further benefits of the HVAF process are claimed to be lower process costs and higher deposition rates. In this study, the focus is set on to the applicability of Fe/TiC coatings by HVAF in general. The Fe/TiC HVAF coating could be produced, successfully. The HVAF- and HVOF-coatings, produced with the same powder, were investigated using micro-hardness, porosity, wear and corrosion tests. A similar wear coefficient and micro-hardness for both processes could be achieved. Furthermore the propane/hydrogen proportion of the HVAF process and its influence on the coating thickness and the porosity was investigated.

Physical modeling of the impingement of an air jet on a water surface; Modelado fisico de la incidencia de un chorro de aire sobre una superficie de agua

Energy Technology Data Exchange (ETDEWEB)

Solorzano-Lopez, J.; Ramirez-Argaez, M.A.; Zenit, R.

2010-07-01

The use of gas jets (oxygen) plays a key role in several steelmaking processes as in the Basic Oxygen Furnace (BOF) or in the Electric Arc Furnace (EAF). Those jets improve heat, mass and momentum transfer in the liquid metal, mixing of chemical species enhancing and govern the formation of foaming slag. In this work experimental measurements were performed to determine the dimensions of the cavity formed at the liquid free surface caused by a gas jet impinging on it; also velocities vectors were measured in the zone affected by the gas jet. avities were measured from images from high speed camera and the vector maps were obtained with a Particle Image Velocimetry (PIV) technique. Both velocities and cavities were determined as a function of the main process variables: gas flow rate, distance of the nozzle from the free surface and lance angle. Cavity dimensions were statistically processed treated as a function of the process variables and also as a function of the proper dimensionless numbers that govern these phenomena. It was found that Weber and Froude numbers govern the cavity geometry. Liquid flow driven by the jet is mainly affected by the air flow rate, lance height and angle. (Author).

HISTOPATHOLOGY OF MARGINAL SUPERFICIAL PERIODONTIUM AT MENOPAUSE

Directory of Open Access Journals (Sweden)

A. Georgescu

2012-03-01

Full Text Available Premises: Sexual hormones may affect the general health condition of women, as early as puberty, continuing during pregnancy and also after menopause. Variations of the hormonal levels may cause different – either local or general – pathological modifications. Sexual hormones may also affect periodontal status, favourizing gingival inflammations and reducing periodontal resistance to the action of the bacterial plaque. Scope: Establishment of the correlations between the debut or the manifestation of menopause and the modifications produced in the superficial periodontium. Materials and method: Clinical and paraclinical investigations were performed on female patients with ages between 45 and 66 years, involving macroscopic, microscopic and radiological recording of the aspect of the superificial periodontium (gingiva. Results: Analysis of the histological sections evidenced atrophic and involutive modifications in the marginal superficial periodontium of female patients at menopause. Conclusions: Sexual hormones intervene in the histological equilibrium of the marginal superficial periodontium, influencing the periodontal health status, which explains the correlation between the subjective symptomatology specific to menopause and the histopatological aspect at epithelial level.

Diagnosis and treatment of superficial esophageal cancer.

Science.gov (United States)

Barret, Maximilien; Prat, Frédéric

2018-01-01

Endoscopy allows for the screening, early diagnosis, treatment and follow up of superficial esophageal cancer. Endoscopic submucosal dissection has become the gold standard for the resection of superficial squamous cell neoplasia. Combinations of endoscopic mucosal resection and radiofrequency ablation are the mainstay of the management of Barrett's associated neoplasia. However, protruded, non-lifting or large lesions may be better managed by endoscopic submucosal dissection. Novel ablation tools, such as argon plasma coagulation with submucosal lifting and cryoablation balloons, are being developed for the treatment of residual Barrett's esophagus, since iatrogenic strictures still hamper the development of extensive circumferential resections in the esophagus. Optimal surveillance modalities after endoscopic resection are still to be determined. The assessment of the risk of lymph-node metastases, as well as of the need for additional treatments based on qualitative and quantitative histological criteria, balanced to the patient's condition, requires a dedicated multidisciplinary team decision process. The need for trained endoscopists, expert pathologists and surgeons, and specialized multidisciplinary meetings underlines the role of expert centers in the management of superficial esophageal cancer.

Local superficial hyperthermia in combination with low-dose radiation therapy for palliation of superficially localized metastases

International Nuclear Information System (INIS)

Owczarek, G.; Miszczyk, L.

2005-01-01

Full text: The aim of this study is to evaluate the response of superficially located metastases and local toxicity to microwave hyperthermia combined with radiation therapy. From May 2003 through December 2004 58 patients (33 male, 25 female; mean age 60 years) with lymph nodes or skin metastases were treated with microwave superficial hyperthermia combined with low-dose radiation therapy. Hyperthermia was administered twice weekly with high frequency applicator (∼900 Mhz) with water bolus. The temperature was set to 43 o C for 45 minutes. Radiotherapy was performed daily with dose 2 Gy or 4 Gy per fraction, to a total dose 20 Gy. There were 47 patients with carcinoma, 4 with sarcoma, 7 with melanoma. Treated regions were: head and neck (37 patients), chest wall 8, abdomen wall and groins 4, upper and lower limb 2 and 8 patients respectively. Primary tumor sites were: head and neck region (9 patients), lung 15, alimentary tract 8, breast 5, soft tissue 8, urogenital 4 and 9 patients with primary tumor site unknown. The toxicity was evaluated using 6 step scale: 0-no skin reaction, 1-faint red mark, 2-distinct red mark, 3-blisters, 4-brown mark, 5-necrosis. Presence of pain and its intensity were also analyzed. Diameter of tumor after the treatment was observed. Complete response was achieved in 5 patients (8.5 %), and partial response in 29 patients (50 %), no response was observed in 12 patients (20 %) and progression of tumor in 7 patients (12 %). No skin reaction was observed in 3 patients, faint red mark in 14 patients, distinct red mark in 28 patients, blisters in 8 patients, brown mark in 4 patients and necrosis in 1 patient. The pain occurred in 9 patients but it was no the cause of stopping treatment. Local superficial hyperthermia combined with low-dose radiation therapy is an effective method of treatment in a proportion of patients with superficial metastases. This combination of treatment modalities is well tolerated and is useful for palliation

A directional passive air sampler for monitoring polycyclic aromatic hydrocarbons (PAHs) in air mass

International Nuclear Information System (INIS)

Tao, S.; Liu, Y.N.; Lang, C.; Wang, W.T.; Yuan, H.S.; Zhang, D.Y.; Qiu, W.X.; Liu, J.M.; Liu, Z.G.; Liu, S.Z.; Yi, R.; Ji, M.; Liu, X.X.

2008-01-01

A passive air sampler was developed for collecting polycyclic aromatic hydrocarbons (PAHs) in air mass from various directions. The airflow velocity within the sampler was assessed for its responses to ambient wind speed and direction. The sampler was examined for trapped particles, evaluated quantitatively for influence of airflow velocity and temperature on PAH uptake, examined for PAH uptake kinetics, calibrated against active sampling, and finally tested in the field. The airflow volume passing the sampler was linearly proportional to ambient wind speed and sensitive to wind direction. The uptake rate for an individual PAH was a function of airflow velocity, temperature and the octanol-air partitioning coefficient of the PAH. For all PAHs with more than two rings, the passive sampler operated in a linear uptake phase for three weeks. Different PAH concentrations were obtained in air masses from different directions in the field test. - A novel directional passive air sampler was developed and tested for monitoring PAHs in air masses from different directions

Sensitivity to draught in turbulent air flows

Energy Technology Data Exchange (ETDEWEB)

Todde, V

1998-09-01

Even though the ventilation system is designed to supply air flows at constant low velocity and controlled temperature, the resulting air movement in rooms is strongly characterised by random fluctuations. When an air flow is supplied from an inlet, a shear layer forms between the incoming and the standstill air in the room, and large scale vortices develops by coalescence of the vorticity shed at the inlet of the air supply. After a characteristically downstream distance, large scale vortices loose their identity because of the development of cascading eddies and transition to turbulence. The interaction of these vortical structures will rise a complicated three dimensional air movement affected by fluctuations whose frequencies could vary from fractions of Hz to several KHz. The perception and sensitivity to the cooling effect enhanced by these air movements depend on a number of factors interacting with each other: physical properties of the air flow, part and extension of the skin surface exposed to the air flow, exposure duration, global thermal condition, gender and posture of the person. Earlier studies were concerned with the percentage of dissatisfied subjects as a function of air velocity and temperature. Recently, experimental observations have shown that also the fluctuations, the turbulence intensity and the direction of air velocity have an important impact on draught discomfort. Two experimental investigations have been developed to observe the human reaction to horizontal air movements on bared skin surfaces, hands and neck. Attention was concentrated on the effects of relative turbulence intensity of air velocity and exposure duration on perception and sensitivity to the air movement. The air jet flows, adopted for the draught experiment in the neck, were also the object of an experimental study. This experiment was designed to observe the centre-line velocity of an isothermal circular air jet, as a function of the velocity properties at the outlet

Sound Velocity in Soap Foams

International Nuclear Information System (INIS)

Wu Gong-Tao; Lü Yong-Jun; Liu Peng-Fei; Li Yi-Ning; Shi Qing-Fan

2012-01-01

The velocity of sound in soap foams at high gas volume fractions is experimentally studied by using the time difference method. It is found that the sound velocities increase with increasing bubble diameter, and asymptotically approach to the value in air when the diameter is larger than 12.5 mm. We propose a simple theoretical model for the sound propagation in a disordered foam. In this model, the attenuation of a sound wave due to the scattering of the bubble wall is equivalently described as the effect of an additional length. This simplicity reasonably reproduces the sound velocity in foams and the predicted results are in good agreement with the experiments. Further measurements indicate that the increase of frequency markedly slows down the sound velocity, whereas the latter does not display a strong dependence on the solution concentration

Paintball velocity as a function of distance traveled

Directory of Open Access Journals (Sweden)

Pat Chiarawongse

2008-06-01

Full Text Available The relationship between the distance a paintball travels through air and its velocity is investigated by firing a paintball into a ballistic pendulum from a range of distances. The motion of the pendulum was filmed and analyzed by using video analysis software. The velocity of the paintball on impact was calculated from the maximum horizontal displacement of the pendulum. It is shown that the velocity of a paintball decreases exponentially with distance traveled, as expected. The average muzzle velocity of the paint balls is found with an estimate of the drag coefficient.

Paintball velocity as a function of distance traveled

Directory of Open Access Journals (Sweden)

Pat Chiarawongse

2008-06-01

Full Text Available The relationship between the distance a paintball travels through air and its velocity is investigated by firing a paintball into a ballistic pendulum from a range of distances. The motion of the pendulum was filmed and analyzed by using video analysis software. The velocity of the paintball on impact was calculated from the maximum horizontal displacement of the pendulum. It is shown that the velocity of a paintball decreases exponentially with distance traveled, as expected. The average muzzle velocity of the paint balls is found with an estimate of the drag coefficient

Superficial parotidectomy via facelift incision

NARCIS (Netherlands)

Lohuis, Peter J. F. M.; Tan, M. Liane; Bonte, Katrien; van den Brekel, Michiel W. M.; Balm, Alfons J. M.; Vermeersch, Hubert B.

2009-01-01

The stigma of a visually prominent facial scar following parotid surgery can be distressing to a young patient. The surgical technique of parotidectomy via a facelift incision is described and evaluated. Thirty patients with a benign lesion of the parotid gland underwent a partial superficial

Physiological Laterality of Superficial Cerebral Veins on Susceptibility-Weighted Imaging.

Science.gov (United States)

Matsushima, Satoshi; Shimizu, Tetsuya; Gomi, Taku; Fukuda, Kunihiko

The purpose of this study is to evaluate whether laterality of the superficial cerebral veins can be seen on susceptibility-weighted imaging (SWI) in patients with no intracranial lesions that affect venous visualization. We retrospectively evaluated 386 patients who underwent brain magnetic resonance imaging including SWI in our institute. Patients with a lesion with the potential to affect venous visualization on SWI were excluded. Two neuroradiologists visually evaluated the findings and scored the visualization of the superficial cerebral veins. Of the 386 patients, 315 (81.6%) showed no obvious laterality on venous visualization, 64 (16.6%) showed left-side dominant laterality, and 7 (1.8%) showed right-side dominant laterality. Left-side dominant physiological laterality exists in the visualization of the superficial cerebral veins on SWI. Therefore, when recognizing left-side dominant laterality of the superficial cerebral veins on SWI, the radiologist must also consider the possibility of physiological laterality.

Determination of burning velocity of methane-air mixtures using soap bubbles and a hot-wire anemometer

Energy Technology Data Exchange (ETDEWEB)

Sakai, Yukio

1987-12-25

The rate of combustion of the mixture of methane and air under a constant atmospheric pressure was determined using a soap bubble and a hot-wire anemometer. The flame propagation velocity, Ss, of the specified ratio of mixed gas confined in a soap bubble regarded as a transparent vessel was recorded using the multi-exposurement schlieren method by igniting the gas at the centre of bubble. The velocity of mixed gas, Sg, in front of the flame was measured by the hot-wire anemometer installed in the soap bubble to obtain the rate of combustion Su (Ss-Sg). The maximum Su was 45 cm/s obtained at the ratio of equivalent amounts of 1.08, which agreed with the theoretical value of one-dimensional flame. This is because the measuring method accords with the definition of rate of combustion. Su was 12.5 and 11.0 cm/s at the ratio of equivalent amounts of 0.6 and 1.6, respectively. The measurements by this method considerably agreed with those by conventional similar methods and other high-accuracy methods. The method is applicable accurately to various combustible mixed gas. (6 figs, 1 tab, 18 refs)

Integral Design Methodology of Photocatalytic Reactors for Air Pollution Remediation

Directory of Open Access Journals (Sweden)

Claudio Passalía

2017-06-01

Full Text Available An integral reactor design methodology was developed to address the optimal design of photocatalytic wall reactors to be used in air pollution control. For a target pollutant to be eliminated from an air stream, the proposed methodology is initiated with a mechanistic derived reaction rate. The determination of intrinsic kinetic parameters is associated with the use of a simple geometry laboratory scale reactor, operation under kinetic control and a uniform incident radiation flux, which allows computing the local superficial rate of photon absorption. Thus, a simple model can describe the mass balance and a solution may be obtained. The kinetic parameters may be estimated by the combination of the mathematical model and the experimental results. The validated intrinsic kinetics obtained may be directly used in the scaling-up of any reactor configuration and size. The bench scale reactor may require the use of complex computational software to obtain the fields of velocity, radiation absorption and species concentration. The complete methodology was successfully applied to the elimination of airborne formaldehyde. The kinetic parameters were determined in a flat plate reactor, whilst a bench scale corrugated wall reactor was used to illustrate the scaling-up methodology. In addition, an optimal folding angle of the corrugated reactor was found using computational fluid dynamics tools.

Computations in the deep vs superficial layers of the cerebral cortex.

Science.gov (United States)

Rolls, Edmund T; Mills, W Patrick C

2017-11-01

A fundamental question is how the cerebral neocortex operates functionally, computationally. The cerebral neocortex with its superficial and deep layers and highly developed recurrent collateral systems that provide a basis for memory-related processing might perform somewhat different computations in the superficial and deep layers. Here we take into account the quantitative connectivity within and between laminae. Using integrate-and-fire neuronal network simulations that incorporate this connectivity, we first show that attractor networks implemented in the deep layers that are activated by the superficial layers could be partly independent in that the deep layers might have a different time course, which might because of adaptation be more transient and useful for outputs from the neocortex. In contrast the superficial layers could implement more prolonged firing, useful for slow learning and for short-term memory. Second, we show that a different type of computation could in principle be performed in the superficial and deep layers, by showing that the superficial layers could operate as a discrete attractor network useful for categorisation and feeding information forward up a cortical hierarchy, whereas the deep layers could operate as a continuous attractor network useful for providing a spatially and temporally smooth output to output systems in the brain. A key advance is that we draw attention to the functions of the recurrent collateral connections between cortical pyramidal cells, often omitted in canonical models of the neocortex, and address principles of operation of the neocortex by which the superficial and deep layers might be specialized for different types of attractor-related memory functions implemented by the recurrent collaterals. Copyright © 2017 Elsevier Inc. All rights reserved.

Long-term evolution of superficial optic disc drusen

DEFF Research Database (Denmark)

Larsen, Lasse Malmqvist; Lund-Andersen, Henrik; Hamann, Steffen

2017-01-01

with hereditary ODD were included. Results: Mean age at initial and follow-up examination was, respectively, 16.8 and 73.3 years. The median follow-up time was 56 years. A minimal or non-existing change in superficial ODD anatomy (size and number) was seen in 10 of 12 eyes. There was a tendency towards more......Purpose: Optic disc drusen (ODD) is hyaline deposits in the optic nerve head seen in 1-2% of the population. Long-term evolution of ODD anatomy and visual field defects in ODD patients is a key factor for learning more about pathophysiology and prognosis of the condition. With a median follow......-up period of 56 years, this is the first study that evaluates superficial optic disc anatomy and visual fields in patients with ODD over a life span. Methods: Observational case series investigating progression of superficial optic disc anatomy and visual fields in ODD patients. Eight patients...

What factors control superficial lava dome explosivity?

Science.gov (United States)

Boudon, Georges; Balcone-Boissard, Hélène; Villemant, Benoît; Morgan, Daniel J

2015-09-30

Dome-forming eruption is a frequent eruptive style and a major hazard on numerous volcanoes worldwide. Lava domes are built by slow extrusion of degassed, viscous magma and may be destroyed by gravitational collapse or explosion. The triggering of lava dome explosions is poorly understood: here we propose a new model of superficial lava-dome explosivity based upon a textural and geochemical study (vesicularity, microcrystallinity, cristobalite distribution, residual water contents, crystal transit times) of clasts produced by key eruptions. Superficial explosion of a growing lava dome may be promoted through porosity reduction caused by both vesicle flattening due to gas escape and syn-eruptive cristobalite precipitation. Both processes generate an impermeable and rigid carapace allowing overpressurisation of the inner parts of the lava dome by the rapid input of vesiculated magma batches. The relative thickness of the cristobalite-rich carapace is an inverse function of the external lava dome surface area. Explosive activity is thus more likely to occur at the onset of lava dome extrusion, in agreement with observations, as the likelihood of superficial lava dome explosions depends inversely on lava dome volume. This new result is of interest for the whole volcanological community and for risk management.

Modelización de la tensión superficial de surfactantes no iónicos

OpenAIRE

Arias Barros, Serxio Ith

2016-01-01

En el presente trabajo se realiza un tratamiento cuantitativo de la tensión superficial dinámica a través de diferentes aproximaciones matemáticas, considerando un mecanismo controlado por difusión. El modelo clásico se ha modificado para que describa las condiciones experimentales de forma más precisa al considerar un dominio de difusión finito. Se han fijado los límites del dominio de forma que la concentración en esta región permanezca constante tras la adsorción en la interfase aire-agua,...

Superficie Específica y Estado Vital de la Materia

OpenAIRE

J. Hernando Ordoñez

1992-01-01

Se propone reemplazar el término de materia viva por el de estado vital de la materia por considerarlo adecuado, pues la materia es la misma, lo que cambia es su estado. Se estudia la relación entre la superficie específica y el estado vital de la materia. Constante del estado vital y el valor crítico de la superficie específica. Qué es la fuerza de inducción vital? Diferenciación funcional de las células. Cómo regula la unidad biológica su superficie específica? La materia que piens...

SUPERFICIAL CERVICAL PLEXUS BLOCK

Directory of Open Access Journals (Sweden)

Komang Mega Puspadisari

2014-01-01

Full Text Available Superficial cervical plexus block is one of the regional anesthesia in  neck were limited to thesuperficial fascia. Anesthesia is used to relieve pain caused either during or after the surgery iscompleted. This technique can be done by landmark or with ultrasound guiding. The midpointof posterior border of the Sternocleidomastoid was identified and the prosedure done on thatplace or on the level of cartilage cricoid.

Metodologia para obtenção do hidrograma de escoamento superficial em encostas e canais. Parte II: modelo computacional e análise de sensibilidade Methodology for obtention of superficial flow hydrograph in hillsides and canals. Part II: computer model and sensitivity analysis

Directory of Open Access Journals (Sweden)

José M. A. Silva

2006-12-01

Full Text Available Estimativas de vazão máxima de escoamento superficial são necessárias para o projeto de obras hidráulicas em bacias urbanas e rurais. A dificuldade em aplicar os procedimentos disponíveis para calcular a variação do escoamento superficial com o tempo e de seu valor máximo deve-se à inexatidão dos métodos usados para esse objetivo e à variabilidade nos resultados que podem ser obtidos por profissionais que usem o mesmo procedimento. Dessa forma, a investigação de um método que produza estimativas confiáveis da vazão máxima e do hidrograma de escoamento superficial é de grande interesse. Neste trabalho, desenvolveu-se e avaliou-se a sensibilidade de um software (HIDROGRAMA 2.1 que permite a obtenção do hidrograma de escoamento superficial, da vazão máxima e seu tempo de ocorrência, da altura e da velocidade máximas do escoamento, do volume e da lâmina de escoamento superficial em encosta e em canais. O modelo apresentou grande sensibilidade ao período de retorno, à taxa de infiltração estável e ao comprimento da encosta e do canal.Estimative of maximum runoff flow rates are essential for the projects of hydraulic urban and rural basins. The difficulty in applying the available procedures to estimate the temporary variation of the flow rate and its maximum value is due to the inaccuracy of some methods that are usually used and to the big variability of results that can be obtained by different professionals that use the same procedures. Therefore, research of a method that produces trustworthy assessment of peak-flow rates and hydrographs is of great interest. This paper describes the development and sensitivity analysis of a software (HIDROGRAMA 2.1 that allows obtaining surface runoff hydrograph, peak flow rate and its time of occurrence, runoff maximum height, runoff velocity and runoff volume. The model presented great sensibility to precipitation return period, infiltration rate after long time of wetting and

[Time lag effect between poplar' s sap flow velocity and microclimate factors in agroforestry system in West Liaoning Province].

Science.gov (United States)

Di, Sun; Guan, De-xin; Yuan, Feng-hui; Wang, An-zhi; Wu, Jia-bing

2010-11-01

By using Granier's thermal dissipation probe, the sap flow velocity of the poplars in agroforestry system in west Liaoning was continuously measured, and the microclimate factors were measured synchronously. Dislocation contrast method was applied to analyze the sap flow velocity and corresponding air temperature, air humidity, net radiation, and vapor pressure deficit to discuss the time lag effect between poplar' s sap flow velocity and microclimate factors on sunny days. It was found that the poplar's sap flow velocity advanced of air temperature, air humidity, and vapor pressure deficit, and lagged behind net radiation. The sap flow velocity in June, July, August, and September was advanced of 70, 30, 50, and 90 min to air temperature, of 80, 30, 40, and 90 min to air humidity, and of 90, 50, 70, and 120 min to vapor pressure deficit, but lagged behind 10, 10, 40, and 40 min to net radiation, respectively. The time lag time of net radiation was shorter than that of air temperature, air humidity, and vapor pressure. The regression analysis showed that in the cases the time lag effect was contained and not, the determination coefficients between comprehensive microclimate factor and poplar's sap flow velocity were 0.903 and 0.855, respectively, indicating that when the time lag effect was contained, the determination coefficient was ascended by 2.04%, and thus, the simulation accuracy of poplar's sap flow velocity was improved.

CFD Simulation of Air Velocity Distribution in Occupied Livestock Buildings

DEFF Research Database (Denmark)

Svidt, Kjeld; Zhang, G.; Bjerg, B.

In modem livestock buildings the design of the ventilation systems is important in order to obtain good air distribution. The use of Computational Fluid Dynamics for predicting the air flow and air quality makes it possible to include the effect of room geometry, equipment and occupants in the de......In modem livestock buildings the design of the ventilation systems is important in order to obtain good air distribution. The use of Computational Fluid Dynamics for predicting the air flow and air quality makes it possible to include the effect of room geometry, equipment and occupants....... In this study laboratory measurements in a ventilated test room with "pig simulators" are compared with CFD-simulations....

Measurement of gas flow velocities by laser-induced gratings

Energy Technology Data Exchange (ETDEWEB)

Hemmerling, B; Stampanoni-Panariello, A [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Kozlov, A D.N. [General Physics Institute, Moscow (Russian Federation)

1999-08-01

Time resolved light scattering from laser-induced electrostrictive gratings was used for the determination of flow velocities in air at room temperature. By measuring the velocity profile across the width of a slit nozzle we demonstrated the high spatial resolution (about 200 mm) of this novel technique. (author) 3 figs., 1 ref.

DETERMINATION OF SUPERFICIAL ABSORBED DOSE FROM EXTERNAL EXPOSURE OF WEAKLY PENETRATING RADIATIONS

Institute of Scientific and Technical Information of China (English)

陈丽姝

1994-01-01

The methods of determining the superficial absorbed dose distributions in a water phantom by means of the experiments and available theories have been reported.The distributions of beta dose were measured by an extrapolation ionization chamber at definite depthes corresponding to some superficial organs and tissues such as the radiosensitive layer of the skin,cornea,sclera,anterior chamber and lens of eyeball.The ratios among superficial absorbed dose D(0.07) and average absorbed doses at the depthes 1,2,3,4,5 and 6mm are also obtained with Cross's methods.They can be used for confining the deterministic effects of some superficial tissues and organs such as the skin and the components of eyeball for weakly penetrating radiations.

Optimization of recirculating laminar air flow in operating room air conditioning systems

Directory of Open Access Journals (Sweden)

Enver Yalcin

2016-04-01

Full Text Available The laminar flow air-conditioning system with 100% fresh air is used in almost all operating rooms without discrimination in Turkey. The laminar flow device which is working with 100% fresh air should be absolutely used in Type 1A operating rooms. However, there is not mandatory to use of 100% fresh air for Type 1B defined as places performed simpler operation. Compared with recirculating laminar flow, energy needs of the laminar flow with 100 % fresh air has been emerged about 40% more than re-circulated air flow. Therefore, when a recirculating laminar flow device is operated instead of laminar flow system with 100% fresh air in the Type 1B operating room, annual energy consumption will be reduced. In this study, in an operating room with recirculating laminar flow, optimal conditions have been investigated in order to obtain laminar flow form by analyzing velocity distributions at various supply velocities by using computational fluid dynamics method (CFD.

Impact of individually controlled facially applied air movement on perceived air quality at high humidity

DEFF Research Database (Denmark)

Skwarczynski, Mariusz; Melikov, Arsen Krikor; Kaczmarczyk, J.

2010-01-01

and local air velocity under a constant air temperature of 26 degrees C, namely: 70% relative humidity without air movement, 30% relative humidity without air movement and 70% relative humidity with air movement under isothermal conditions. Personalized ventilation was used to supply room air from the front...

Superficial Priming in Episodic Recognition

Science.gov (United States)

Dopkins, Stephen; Sargent, Jesse; Ngo, Catherine T.

2010-01-01

We explored the effect of superficial priming in episodic recognition and found it to be different from the effect of semantic priming in episodic recognition. Participants made recognition judgments to pairs of items, with each pair consisting of a prime item and a test item. Correct positive responses to the test item were impeded if the prime…

Air movement - good or bad?

DEFF Research Database (Denmark)

Toftum, Jørn

2004-01-01

when air movement is desirable and when it is not. At temperatures up to 22-23oC, at sedentary activity and with occupants feeling neutral or cooler there is a risk of air movement being perceived as unacceptable, even at low velocities. In particular, a cool overall thermal sensation negatively...... influences the subjective perception of air movement. With occupants feeling warmer than neutral, at temperatures above 23oC or at raised activity levels, humans generally do not feel draught at air velocities typical for indoor environments (up to around 0.4 m/s). In the higher temperature range, very high...

Pigmented basal cell carcinoma mimicking a superficial spreading melanoma

Directory of Open Access Journals (Sweden)

Paula Hasbún Acuña

2016-12-01

Full Text Available Resumen El carcinoma basocelular es el cáncer de piel más frecuente, especialmente en personas de edad avanzada. El carcinoma basocelular pigmentado es una variante poco común que se ha descrito en la literatura como una lesión nodular hiperpigmentada. En raras ocasiones puede presentarse en forma de una extensa placa pigmentada, la cual puede ser clínicamente indistinguible del melanoma maligno de extensión superficial y de la enfermedad de Bowen. La dermatoscopía tiene una alta sensibilidad en el diagnóstico del carcinoma basocelular, cuando se utilizan los criterios de Menzies, aunque el diagnóstico final es histopatológico. El objetivo del presente trabajo es reportar y analizar el caso de una paciente con un extenso carcinoma basocelular superficial pigmentado, que simula un melanoma maligno de extensión superficial.

Separation of the metallic and non-metallic fraction from printed circuit boards employing green technology

Energy Technology Data Exchange (ETDEWEB)

Estrada-Ruiz, R.H., E-mail: rhestrada@itsaltillo.edu.mx; Flores-Campos, R., E-mail: rcampos@itsaltillo.edu.mx; Gámez-Altamirano, H.A., E-mail: hgamez@itsaltillo.edu.mx; Velarde-Sánchez, E.J., E-mail: ejvelarde@itsaltillo.edu.mx

2016-07-05

Highlights: • Small sizes of particles are required in order to separate the different fractions. • Inverse flotation process is an efficient green technology to separate fractions. • Superficial air velocity is the main variable in the inverse flotation process. • Inverse flotation is a green process because the pulṕs pH is 7.0 during the test. - Abstract: The generation of electrical and electronic waste is increasing day by day; recycling is attractive because of the metallic fraction containing these. Nevertheless, conventional techniques are highly polluting. The comminution of the printed circuit boards followed by an inverse flotation process is a clean technique that allows one to separate the metallic fraction from the non-metallic fraction. It was found that particle size and superficial air velocity are the main variables in the separation of the different fractions. In this way an efficient separation is achieved by avoiding the environmental contamination coupled with the possible utilization of the different fractions obtained.

Failure analysis of thermally cycled columnar thermal barrier coatings produced by high-velocity-air fuel and axial-suspension-plasma spraying: A design perspective

Czech Academy of Sciences Publication Activity Database

Ganvir, A.; Vaidhyanathan, V.; Markocsan, N.; Gupta, M.; Pala, Zdeněk; Lukáč, František

2018-01-01

Roč. 44, č. 3 (2018), s. 3161-3172 ISSN 0272-8842 Institutional support: RVO:61389021 Keywords : Columnar Thermal Barrier Coatings * Axial Suspension Plasma spraying * Thermal Cyclic Fatigue * High Velocity Air Fuel Spraying Subject RIV: JK - Corrosion ; Surface Treatment of Materials OBOR OECD: Coating and films Impact factor: 2.986, year: 2016 https://www.sciencedirect.com/science/article/pii/S0272884217325403

Superficial x-ray in-vivo dosimetry with MOSFET detectors

International Nuclear Information System (INIS)

Cheung, T.; Yu, P.K.N.; Butson, M.J.; Cancer Services, Wollongong, NSW

2004-01-01

Full text: This note investigates in-vivo dosimetry using a Metal Oxide Semiconductor Field Effect Transistor (MOSFET) for radiotherapy treatment at superficial and orthovoltage x-ray energies. This was performed within one fraction of the patient's treatment. Standard measurements along with energy response of the detector are given. Results showed that the MOSFET measurements in-vivo agreed with calculated results on average within ± 5.6% over all superficial and orthovoltage energies. These variations were slightly larger than TLD results with variations between measured and calculated results being ± 5.0% for the same patient measurements. The MOSFET device provides adequate in-vivo dosimetry for superficial and orthovoltage energy treatments with the accuracy of the measurements seeming to be relatively on par with TLD in our case. The MOSFET does have the advantage of returning a relatively immediate dosimetric result after irradiation. Copyright (2004) Australasian College of Physical Scientists and Engineers in Medicine

Doppler Lidar Vertical Velocity Statistics Value-Added Product

Energy Technology Data Exchange (ETDEWEB)

Newsom, R. K. [DOE ARM Climate Research Facility, Washington, DC (United States); Sivaraman, C. [DOE ARM Climate Research Facility, Washington, DC (United States); Shippert, T. R. [DOE ARM Climate Research Facility, Washington, DC (United States); Riihimaki, L. D. [DOE ARM Climate Research Facility, Washington, DC (United States)

2015-07-01

Accurate height-resolved measurements of higher-order statistical moments of vertical velocity fluctuations are crucial for improved understanding of turbulent mixing and diffusion, convective initiation, and cloud life cycles. The Atmospheric Radiation Measurement (ARM) Climate Research Facility operates coherent Doppler lidar systems at several sites around the globe. These instruments provide measurements of clear-air vertical velocity profiles in the lower troposphere with a nominal temporal resolution of 1 sec and height resolution of 30 m. The purpose of the Doppler lidar vertical velocity statistics (DLWSTATS) value-added product (VAP) is to produce height- and time-resolved estimates of vertical velocity variance, skewness, and kurtosis from these raw measurements. The VAP also produces estimates of cloud properties, including cloud-base height (CBH), cloud frequency, cloud-base vertical velocity, and cloud-base updraft fraction.

Clinicomycological Characterization of Superficial Mycoses from a Tertiary Care Hospital in Nepal.

Science.gov (United States)

Khadka, Sundar; Sherchand, Jeevan Bahadur; Pokharel, Dinesh Binod; Pokhrel, Bharat Mani; Mishra, Shyam Kumar; Dhital, Subhash; Rijal, Basista

2016-01-01

Background . Superficial mycosis is a common fungal infection worldwide, mainly caused by dermatophytes. However, the prevalence of species varies geographically. In addition, fungal treatment is best guided according to species isolated. This study was carried out to determine the clinical as well as mycological profile of superficial mycoses in a tertiary care hospital, Nepal. Methods . This was a prospective case-control laboratory based study conducted over a period of six months from January to June 2014 at Tribhuvan University Teaching Hospital, Nepal. A total of 200 specimens were collected from the patients suspected of superficial mycoses. The specimens were macroscopically as well as microscopically examined. The growth was observed up to 4 weeks. Results. Out of total 200 specimens from the patients suspected of superficial mycoses, tinea corporis 50 (25%) was most common clinical types. KOH mount was positive in 89 (44.5%) and culture was positive in 111 (55.5%). Trichophyton mentagrophytes 44 (39.6%) was the most common isolate. Conclusions. The diagnostic yields of KOH mount and culture were found to be complementary to each other. Thus both the methods added with clinical findings are equally important to establish superficial mycosis.

Clinicomycological Characterization of Superficial Mycoses from a Tertiary Care Hospital in Nepal

Directory of Open Access Journals (Sweden)

Sundar Khadka

2016-01-01

Full Text Available Background. Superficial mycosis is a common fungal infection worldwide, mainly caused by dermatophytes. However, the prevalence of species varies geographically. In addition, fungal treatment is best guided according to species isolated. This study was carried out to determine the clinical as well as mycological profile of superficial mycoses in a tertiary care hospital, Nepal. Methods. This was a prospective case-control laboratory based study conducted over a period of six months from January to June 2014 at Tribhuvan University Teaching Hospital, Nepal. A total of 200 specimens were collected from the patients suspected of superficial mycoses. The specimens were macroscopically as well as microscopically examined. The growth was observed up to 4 weeks. Results. Out of total 200 specimens from the patients suspected of superficial mycoses, tinea corporis 50 (25% was most common clinical types. KOH mount was positive in 89 (44.5% and culture was positive in 111 (55.5%. Trichophyton mentagrophytes 44 (39.6% was the most common isolate. Conclusions. The diagnostic yields of KOH mount and culture were found to be complementary to each other. Thus both the methods added with clinical findings are equally important to establish superficial mycosis.

Drift velocity and pressure monitoring of the CMS muon drift chambers

CERN Document Server

Sonnenschein, Lars

2011-01-01

The drift velocity in drift tubes of the CMS muon chambers is a key parameter for the muon track reconstruction and trigger. It needs to be monitored precisely in order to detect any deviation from its nominal value. A change in absolute pressure, a variation of the gas admixture or a contamination of the chamber gas by air affect the drift velocity. Furthermore, the temperature and magnetic field influence its value. First data, taken with a dedicated Velocity Drift Chamber (VDC) built by RWTH Aachen IIIA are presented. Another important parameter to be monitored is the pressure inside the muon drift tube chambers. The differential pressure must not exceed a certain value and the absolute pressure has to be kept slightly above ambient pressure to prevent air from entering into the muon drift tube chambers in case of a leak. Latest drift velocity monitoring results are discussed.

Trauma ocupacional por corpo estranho corneano superficial Occupational trauma due to superficial corneal foreign body

Directory of Open Access Journals (Sweden)

Vanessa Miroski Gerente

2008-04-01

Full Text Available OBJETIVO: Avaliar a epidemiologia do trauma ocular por corpo estranho superficial de córnea. MÉTODOS: Os pacientes atendidos no Pronto-Socorro da Universidade Federal de São Paulo entre abril e junho de 2005 que apresentaram corpo estranho superficial de córnea foram entrevistados. Foram avaliados: sexo, idade, profissão, registro legal do emprego, uso, disponibilidade e tipo de equipamentos de proteção utilizados e a fiscalização do seu uso. O conhecimento das complicações deste tipo de acidente também foi avaliado. Os resultados foram analisados com teste do qui quadrado ou teste de Fisher. RESULTADOS: Foram entrevistados 123 pacientes. Apenas 3 eram do sexo feminino e a idade média foi de 36 anos. A maioria destes traumas ocorreu no ambiente de trabalho (86,2% e 58,4% não possuíam registro legal do emprego. As profissões mais freqüentemente envolvidas foram serralheiro, pedreiro e metalúrgico. Em 79,8% dos locais de trabalho havia equipamentos de proteção e 85,3% dos pacientes eram orientados a usá-los. Em 52,4% dos locais sua utilização era fiscalizada, mas apenas 34,2% usavam no momento do trauma. A utilização foi mais freqüente (p=0,008 e fiscalização mais presente (p=0,0415 entre pacientes com registro legal de emprego. Questionados sobre os riscos, 68,9% dos pacientes tinham consciência das complicações graves deste tipo de acidente. CONCLUSÃO: A maioria dos pacientes tem conhecimento sobre a gravidade do trauma ocular e este tipo de lesão ocorre mesmo em locais com equipamentos de proteção disponíveis, alguns deles até durante o seu uso. Os dados sugerem que enfoque maior da prevenção deve ser na fiscalização e utilização de equipamentos adequados.PURPOSE: To evaluate the epidemiology of superficial corneal foreign body. METHODS: Patients who were seen at the Emergency Service of the Federal University of São Paulo, from April/05 to June/05, were screened and those with superficial corneal

Relating water and air flow characteristics in coarse granular materials

DEFF Research Database (Denmark)

Andreasen, Rune Røjgaard; Canga, Eriona; Poulsen, Tjalfe Gorm

2013-01-01

Water pressure drop as a function of velocity controls w 1 ater cleaning biofilter operation 2 cost. At present this relationship in biofilter materials must be determined experimentally as no 3 universal link between pressure drop, velocity and filter material properties have been established. 4...... Pressure drop - velocity in porous media is much simpler and faster to measure for air than for water. 5 For soils and similar materials, observations show a strong connection between pressure drop – 6 velocity relations for air and water, indicating that water pressure drop – velocity may be estimated 7...... from air flow data. The objective of this study was, therefore, to investigate if this approach is valid 8 also for coarse granular biofilter media which usually consists of much larger particles than soils. In 9 this paper the connection between the pressure drop – velocity relationships for air...

Kinetic study of heavy metal ions removal by ion exchange in batch conical air spouted bed

Directory of Open Access Journals (Sweden)

T.M. Zewail

2015-03-01

Full Text Available Spouted bed contactor is a hybrid of fixed and fluidized bed contactors, which retains the advantages of each with good hydrodynamic conditions. The aim of the present study is to investigate the performance of a batch conical air spouted vessel for heavy metal removal by strong cation exchange resins (AMBERJET 1200 Na. The effect of various parameters such as type of heavy metal ions (Ni+2 and Pb+2, contact time, superficial air velocity and initial heavy metal ion concentration on % heavy metal ion removal has been investigated. It has been found that under optimum conditions 98% and 99% removal of Ni+2 and Pb+2 were achieved respectively. Several kinetic models were used to test the experimental data and to examine the controlling mechanism of the sorption process. The present results of Ni+2 and Pb+2 well fit pseudo second order kinetic model with a high correlation coefficient. Both film diffusion and intra-particle diffusion contribute to the ion exchange process. The present study revealed that spouted bed vessel may provide an effective alternative for conducting ion exchange reactions.

Improvement of the Quality and the Shelf Life of the High Oxygen Modified Atmosphere Packaged Veal by Superficial Spraying with Dihydroquercetin Solution

Directory of Open Access Journals (Sweden)

Stefan Georgiev Dragoev

2014-01-01

Full Text Available The improvement of quality and the shelf life of veal by combination of 80%O2/20%CO2 modified atmosphere packaging and superficial spraying with 0.02% dihydroquercetin solutions was studied. The control samples C, air packaged only, D, air packaged sprayed by 0.02% dihydroquercetin solution, MAP, modified atmosphere packaging only, BMAP, modified atmosphere packaging sprayed by 0.02% butylated hydroxytoluene solution, and DMAP, modified atmosphere packaging sprayed by 0.02% dihydroquercetin solution, were measured. The best results were obtained in modified atmosphere packaging sprayed by 0.02% dihydroquercetin solution. Comparisons with control samples were expressed as reduction in acid value with 27.72%, peroxide value with 64.74%, 2-thiobarbituric acid reactive substances (TBARS with 65.71%, and the pH with 6.18%. The acid and peroxide values, TBARS, and pH were decreased linearly in response when applying the combination of 80%O2/20%CO2 modified atmosphere packaging and superficial spraying with 0.02% dihydroquercetin solutions (P0.05. According to results obtained it was concluded that 80%O2/20%CO2 modified atmosphere packaged veal stored at 0±0.5°C after 0.02% dihydroquercetin solution treatment can preserve its quality and shelf life to 15 d postmortem.

Ultrasound of musculoskeletal soft-tissue tumors superficial to the investing fascia.

Science.gov (United States)

Hung, Esther Hiu Yee; Griffith, James Francis; Ng, Alex Wing Hung; Lee, Ryan Ka Lok; Lau, Domily Ting Yi; Leung, Jason Chi Shun

2014-06-01

The objective of our study was to evaluate the diagnostic accuracy of ultrasound in assessing musculoskeletal soft-tissue tumors superficial to the investing fascia. Seven hundred fourteen superficial soft-tissue tumors evaluated with ultrasound by two musculoskeletal radiologists were retrospectively reviewed. In all ultrasound reports, the reporting radiologists provided one, two, or three diagnoses depending on their perceived level of diagnostic certainty. Two hundred forty-seven tumors had subsequent histologic correlation, thus allowing the accuracy of the ultrasound diagnosis to be determined. Images of the lesions with a discordant ultrasound diagnosis and histologic diagnosis were reviewed, and the ultrasound features were further classified as concordant with the known histologic diagnosis, concordant with the known histologic diagnosis with atypical features present, or discordant with the known histologic diagnosis. Four hundred sixty-seven tumors without pathologic confirmation were followed up clinically. Overall the accuracy of ultrasound examination for assessing superficial soft-tissue masses was 79.0% when all differential diagnoses were considered and 77.0% when only the first differential diagnosis was considered. The sensitivity and specificity of the first ultrasound diagnosis were 95.2% and 94.3%, respectively, for lipoma; 73.0% and 97.7% for vascular malformation; 80.0% and 95.4% for epidermoid cyst; and 68.8% and 95.2% for nerve sheath tumor. Reduced observer awareness of specific tumor entities tended to contribute to underdiagnosis more than poor specificity of ultrasound findings. Most tumors (236/247, 96%) were benign. The sensitivity and specificity of ultrasound for identifying malignant superficial soft-tissue tumors was 94.1% and 99.7%, respectively. The diagnostic accuracy of ultrasound in the assessment of superficial musculoskeletal soft-tissue tumors is high and can be improved through increased radiologist awareness of less

Impact of co-flow air on buoyant diffusion flames flicker

Energy Technology Data Exchange (ETDEWEB)

Gohari Darabkhani, H., E-mail: h.g.darabkhani@gmail.com [School of Mechanical, Aerospace and Civil Engineering, University of Manchester, Sackville Street, Manchester M13 9PL (United Kingdom); Wang, Q.; Chen, L.; Zhang, Y. [Mechanical Engineering Department, University of Sheffield, Mapping Street, Sheffield S1 3JD (United Kingdom)

2011-08-15

Highlights: {yields} We present the co-flow effects on flickering behaviour of diffusion flames. {yields} Co-flow air is shown to fully suppress the buoyancy driven flame oscillations. {yields} Schlieren and PIV illustrate the shift of outer vortices beyond the flame zone. {yields} Stability controlling parameter as a ratio of air to fuel velocities is presented. {yields} Equation for linear increase in flickering frequency by co-flow air is presented. - Abstract: This paper describes experimental investigation of co-flow air velocity effects on the flickering behaviour of laminar non-lifted methane diffusion flames. Chemiluminescence, high-speed photography, schlieren and Particle Imaging Velocimetry (PIV), have been used to study the changes in the flame/vortex interactions as well as the flame flickering frequency and magnitude by the co-flow air. Four cases of methane flow rates at different co-flow air velocities are investigated. It has been observed that the flame dynamics and stability of co-flow diffusion flames are strongly affected by the co-flow air velocity. When the co-flow velocity has reached a certain value the buoyancy driven flame oscillation was completely suppressed. The schlieren and PIV imaging have revealed that the co-flow of air is able to push the initiation point of the outer toroidal vortices beyond the visible flame to create a very steady laminar flow region in the reaction zone. Then the buoyancy driven instability is only effective in the plume of hot gases above the visible flame. It is observed that a higher co-flow rate is needed in order to suppress the flame flickering at a higher fuel flow rate. Therefore the ratio of the air velocity to the fuel velocity, {gamma}, is a stability controlling parameter. The velocity ratio, {gamma}, was found to be 0.72 for the range of tested flow rates. The dominant flickering frequency was observed to increase linearly with the co-flow rate (a) as; f = 0.33a + 11. The frequency amplitudes

Volumetric Modulated Arc Therapy (VMAT) Treatment Planning for Superficial Tumors

International Nuclear Information System (INIS)

Zacarias, Albert S.; Brown, Mellonie F.; Mills, Michael D.

2010-01-01

The physician's planning objective is often a uniform dose distribution throughout the planning target volume (PTV), including superficial PTVs on or near the surface of a patient's body. Varian's Eclipse treatment planning system uses a progressive resolution optimizer (PRO), version 8.2.23, for RapidArc dynamic multileaf collimator volumetric modulated arc therapy planning. Because the PRO is a fast optimizer, optimization convergence errors (OCEs) produce dose nonuniformity in the superficial area of the PTV. We present a postsurgical cranial case demonstrating the recursive method our clinic uses to produce RapidArc treatment plans. The initial RapidArc treatment plan generated using one 360 o arc resulted in substantial dose nonuniformity in the superficial section of the PTV. We demonstrate the use of multiple arcs to produce improved dose uniformity in this region. We also compare the results of this superficial dose compensation method to the results of a recursive method of dose correction that we developed in-house to correct optimization convergence errors in static intensity-modulated radiation therapy treatment plans. The results show that up to 4 arcs may be necessary to provide uniform dose to the surface of the PTV with the current version of the PRO.

Tendon vibration attenuates superficial venous vessel response of the resting limb during static arm exercise

Directory of Open Access Journals (Sweden)

Ooue Anna

2012-11-01

Full Text Available Abstract Background The superficial vein of the resting limb constricts sympathetically during exercise. Central command is the one of the neural mechanisms that controls the cardiovascular response to exercise. However, it is not clear whether central command contributes to venous vessel response during exercise. Tendon vibration during static elbow flexion causes primary muscle spindle afferents, such that a lower central command is required to achieve a given force without altering muscle force. The purpose of this study was therefore to investigate whether a reduction in central command during static exercise with tendon vibration influences the superficial venous vessel response in the resting limb. Methods Eleven subjects performed static elbow flexion at 35% of maximal voluntary contraction with (EX + VIB and without (EX vibration of the biceps brachii tendon. The heart rate, mean arterial pressure, and rating of perceived exertion (RPE in overall and exercising muscle were measured. The cross-sectional area (CSAvein and blood velocity of the basilic vein in the resting upper arm were assessed by ultrasound, and blood flow (BFvein was calculated using both variables. Results Muscle tension during exercise was similar between EX and EX + VIB. However, RPEs at EX + VIB were lower than those at EX (P P vein in the resting limb at EX decreased during exercise from baseline (P vein at EX + VIB did not change during exercise. CSAvein during exercise at EX was smaller than that at EX + VIB (P vein did not change during the protocol under either condition. The decreases in circulatory response and RPEs during EX + VIB, despite identical muscle tension, showed that activation of central command was less during EX + VIB than during EX. Abolishment of the decrease in CSAvein during exercise at EX + VIB may thus have been caused by a lower level of central command at EX + VIB rather than EX. Conclusion Diminished central command induced by tendon

Comparison of personal air samplers and static air samplers

International Nuclear Information System (INIS)

Carter, M.W.; Lumsden, B.

1979-01-01

The authors demonstrate that radioactive air contamination levels calculated from PAS results will always be higher than air contamination levels calculated from SAS results, other conditions being equal. The most probable explanation seems to be in a relationship between the sampling velocity and the particle size of the dust sampled

Superficial siderosis of the central nervous system - A case report

International Nuclear Information System (INIS)

Mannalini, S.

1997-01-01

There is little information on superficial siderosis of the central nervous system (CNS) in the literature, mainly due to the rarity of the disease, the difficulties in diagnosis (autopsy pre magnetic resonance imaging (MRI)) and the long latency of the symptoms. With the advent of MRI, for the first time we are able to make a positive in vivo diagnosis. But this comes at a time of less disease incidence, and little clinical awareness. MRI is able to make the diagnosis because of the strong paramagnetic effect of haemosiderin, the blood by-product that is deposited on the brain surface in superficial siderosis of the CNS. The ability of the brain to biosynthesize ferritin in response to prolonged contact with haemosiderin is thought to be the most important factor in the pathogenesis of superficial siderosis. (author)

Volumetric and superficial characterization of carbon activated; Caracterizacion volumetrica y superficial de carbon activado

Energy Technology Data Exchange (ETDEWEB)

Carrera G, L.M.; Garcia S, I.; Jimenez B, J.; Solache R, M.; Lopez M, B.; Bulbulian G, S.; Olguin G, M.T. [Departamento de Quimica, Gerencia de Ciencias Basicas, Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

2000-07-01

The activated carbon is the resultant material of the calcination process of natural carbonated materials as coconut shells or olive little bones. It is an excellent adsorbent of diluted substances, so much in colloidal form, as in particles form. Those substances are attracted and retained by the carbon surface. In this work is make the volumetric and superficial characterization of activated carbon treated thermically (300 Centigrade) in function of the grain size average. (Author)

Combustion Velocity of Benzine-Benzol-Air Mixtures in High-Speed Internal-Combustion Engines

Science.gov (United States)

Schnauffer, Kurt

1932-01-01

The present paper describes a device whereby rapid flame movement within an internal-combustion engine cylinder may be recorded and determined. By the aid of a simple cylindrical contact and an oscillograph the rate of combustion within the cylinder of an airplane engine during its normal operation may be measured for gas intake velocities of from 30 to 35 m/s and for velocities within the cylinder of from 20 to 25 m/s. With it the influence of mixture ratios, of turbulence, of compression ratio and kind of fuel on combustion velocity may be determined. Besides the determination of the influence of the above factors on combustion velocity, the degree of turbulence may also be determined. As a unit of reference in estimating the degree of turbulence, the intake velocity of the charge is chosen.

Development of a high velocity rain erosion test method

Energy Technology Data Exchange (ETDEWEB)

Chung, Dong Teak; Jin, Doo Han [Korea University of Technology and Education, Cheonan (Korea, Republic of); Kang, Hyung [Agency for Defense Development, Daejeon (Korea, Republic of)

2009-07-01

The nose of a missile, flying through raining region with a supersonic speed, is subjected to the rain erosion because the nose is made of a brittle ceramic material. A simple yet very effective rain erosion test method is developed. The sabot assembly similar to the hypodermic syringe carries specific amount of water is launched by a low pressure air gun. After the stopper stop the sabot assembly by impact, the steel plunger continues moving toward to squeeze the silicon rubber in front. The pressurized silicon rubber then is squeezed through the orifice in front of the sabot at high velocity, thus, accelerates the water droplet to higher velocity. The droplet velocity up to 800m/s is successfully attained using a low pressure air gun. The ceramic specimen assembly is placed in front of the high speed water droplet and the rain erosion damage on the surface of the specimen is observed.

Clinicopahological features of superficial basaloid squamous cell carcinoma of the esophagus.

Science.gov (United States)

Oguma, J; Ozawa, S; Kazuno, A; Nitta, M; Ninomiya, Y; Tomita, S

2017-12-01

Basaloid squamous cell carcinoma (BSC) of the esophagus is classified as an epithelial malignant tumor and is a rare variant of squamous cell carcinoma (SCC). Most previous reports have suggested that advanced BSC has a poorer prognosis than typical SCC because of its high biological malignancy, but the biological activity of superficial BSC remains unclear. Twenty cases of superficial BSC, which underwent surgical resection in Tokai University Hospital between January 2004 and December 2013, were analyzed retrospectively. Among these cases, 19 cases with a T1 depth of invasion (BSC group) were compared with 180 cases of SCC that were resected during the same period and were pathologically diagnosed as T1 (SCC group). The frequency of lymph node metastasis in the T1 BSC group was significantly lower (2 patients, 11%) than that in the SCC group (84 patients, 47%) (P = 0.005). The frequency of lymphatic invasion in the BSC group was also lower (9 patients, 47%) than that in the SCC group (131 patients, 73%) (P = 0.021). The pathological type of the metastatic lymph node was BSC in all the superficial BSC cases with lymph node metastasis. This study demonstrated that lymph node metastasis was less likely to occur in cases with superficial BSC than in cases with superficial SCC. © The Authors 2017. Published by Oxford University Press on behalf of International Society for Diseases of the Esophagus. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Drift velocity and pressure monitoring of the CMS muon drift chambers

CERN Document Server

Sonnenschein, Lars

2010-01-01

The drift velocity in drift tubes of the CMS muon chambers is a key parameter for the muon track reconstruction and trigger. It needs to be monitored precisely in order to detect any deviation from its nominal value. A change in absolute pressure, a variation of the gas admixture or a contamination of the chamber gas by air affect the drift velocity. Furthermore, the temperature and magnetic field influence its value. First data, taken with a dedicated Velocity Drift Chamber (VDC) built by RWTH Aachen IIIA are presented. Another important parameter to be monitored is the pressure inside the muon drift tube chambers because the drift velocity depends on it. Furthermore the differential pressure must not exceed a certain value and the absolute pressure has to be kept slightly above ambient pressure to prevent air from entering into the muon drift tube chambers in case of a leak. Latest pressure monitoring results are discussed.

Drift velocity monitoring of the CMS muon drift chambers

CERN Document Server

Sonnenschein, Lars

2010-01-01

The drift velocity in drift tubes of the CMS muon chambers is a key parameter for the muon track reconstruction and trigger. It needs to be monitored precisely in order to detect any deviation from its nominal value. A change in absolute pressure, a variation of the gas admixture or a contamination of the chamber gas by air affect the drift velocity. Furthermore the temperature and magnetic field influence its value. First data, taken with a dedicated Velocity Drift Chamber (VDC) built by RWTH Aachen IIIA are presented.

Air Turbulence and sensation of draught

DEFF Research Database (Denmark)

Fanger, Povl Ole; Melikov, Arsen Krikor; Hanzawa, H.

1988-01-01

the sedentary subjects were exposed to six mean air velocities ranging from 0.05 m/s to 0.40 m/s. The air temperature was kept constant at 23°C. They were asked whether and where they could feel air movement and whether or not it felt uncomfortable. The turbulence intensity had a significant impact...... on the occurence of draught sensation. A model is presented which predicts the percentage of people dissatisfied because of draught as a function of air temperature, mean velocity and turbulence intensity. The model can be a useful tool for quantifying the draught risk in spaces and for developing air distribution...... systems with a low draught risk....

Pure air-plasma bullets propagating inside microcapillaries and in ambient air

KAUST Repository

Lacoste, Deanna; Bourdon, Anne; Kuribara, Koichi; Urabe, Keiichiro; Stauss, Sven; Terashima, Kazuo

2014-01-01

This paper reports on the characterization of air-plasma bullets in microcapillary tubes and in ambient air, obtained without the use of inert or noble gases. The bullets were produced by nanosecond repetitively pulsed discharges, applied in a dielectric barrier discharge configuration. The anode was a tungsten wire with a diameter of 50 μm, centered in the microcapillary, while the cathode was a silver ring, fixed on the outer surface of the fused silica tube. The effects of the applied voltage and the inner diameter of the microcapillary tube on the plasma behavior were investigated. Inside the tubes, while the topology of the bullets seems to be strongly dependent on the diameter, their velocity is only a function of the amplitude of the applied voltage. In ambient air, the propagation of air bullets with a velocity of about 1.25 ×105 m s-1 is observed.

Pure air-plasma bullets propagating inside microcapillaries and in ambient air

KAUST Repository

Lacoste, Deanna

2014-11-04

This paper reports on the characterization of air-plasma bullets in microcapillary tubes and in ambient air, obtained without the use of inert or noble gases. The bullets were produced by nanosecond repetitively pulsed discharges, applied in a dielectric barrier discharge configuration. The anode was a tungsten wire with a diameter of 50 μm, centered in the microcapillary, while the cathode was a silver ring, fixed on the outer surface of the fused silica tube. The effects of the applied voltage and the inner diameter of the microcapillary tube on the plasma behavior were investigated. Inside the tubes, while the topology of the bullets seems to be strongly dependent on the diameter, their velocity is only a function of the amplitude of the applied voltage. In ambient air, the propagation of air bullets with a velocity of about 1.25 ×105 m s-1 is observed.

Structure of two-phase air-water flows. Study of average void fraction and flow patterns

International Nuclear Information System (INIS)

Roumy, R.

1969-01-01

This report deals with experimental work on a two phase air-water mixture in vertical tubes of different diameters. The average void fraction was measured in a 2 metre long test section by means of quick-closing valves. Using resistive probes and photographic techniques, we have determined the flow patterns and developed diagrams to indicate the boundaries between the various patterns: independent bubbles, agglomerated bubbles, slugs, semi-annular, annular. In the case of bubble flow and slug flow, it is shown that the relationship between the average void fraction and the superficial velocities of the phases is given by: V sg = f( ) * g(V sl ). The function g(V sl ) for the case of independent bubbles has been found to be: g(V sl ) = V sl + 20. For semi-annular and annular flow conditions; it appears that the average void fraction depends, to a first approximation only on the ratio V sg /V sl . (author) [fr

Anisotropic diffusion of volatile pollutants at air-water interface

Directory of Open Access Journals (Sweden)

Li-ping Chen

2013-04-01

Full Text Available The volatile pollutants that spill into natural waters cause water pollution. Air pollution arises from the water pollution because of volatilization. Mass exchange caused by turbulent fluctuation is stronger in the direction normal to the air-water interface than in other directions due to the large density difference between water and air. In order to explore the characteristics of anisotropic diffusion of the volatile pollutants at the air-water interface, the relationship between velocity gradient and mass transfer rate was established to calculate the turbulent mass diffusivity. A second-order accurate smooth transition differencing scheme (STDS was proposed to guarantee the boundedness for the flow and mass transfer at the air-water interface. Simulations and experiments were performed to study the trichloroethylene (C2HCl3 release. By comparing the anisotropic coupling diffusion model, isotropic coupling diffusion model, and non-coupling diffusion model, the features of the transport of volatile pollutants at the air-water interface were determined. The results show that the anisotropic coupling diffusion model is more accurate than the isotropic coupling diffusion model and non-coupling diffusion model. Mass transfer significantly increases with the increase of the air-water relative velocity at a low relative velocity. However, at a higher relative velocity, an increase in the relative velocity has no effect on mass transfer.

Human perception of air movement. Impact of frequency and airflow direction on draught sensation

Energy Technology Data Exchange (ETDEWEB)

Genhong Zhou

1999-08-01

Draught is defined as an unwanted local cooling of the human body caused by air movement. Air velocity and temperature are the main characteristics of air movement in rooms. Characteristics of instantaneous air velocity and temperature records previously measured in ventilated indoor spaces were analyzed. Air velocity and temperature fluctuated randomly. The amplitude and frequency of the fluctuations changed over time. Air movements around the human body were measured with a three-dimensional laser Doppler amemometer. A new parameter, equivalent frequency, was defined as an integral single parameter for describing the frequency characteristics of air velocity. The equivalent frequency of a randomly fluctuating velocity is defined as the frequency of sinusoidal velocity fluctuations with the same ratio of the standard deviation of acceleration to the standard deviation of air velocity as in the random velocity fluctuations. The equivalent frequencies of numerous instantaneous air-velocity records measured in ventilated space were analysed. The equivalent frequency of an airflow in an indoor space was found to be 0.1 to 2 Hz. The equivalent frequencies of most of the airflows were between 0.2 and 0.6 Hz. The relation between equivalent frequency and mean air velocity and standard deviation was established. Experiments were performed to identify the impact of the equivalent frequency on the human perception of draught. Forty subjects (20 women and 20 men) were subjected to airflows from behind with mean air velocities of 0.1, 0.2 and 0.3 m/s, with equivalent frequencies from 0 to 1 Hz at an air temperature of 20 deg. C. In this human-subject experimental study the frequency was found to have a significant impact on draught sensation. Subjects were more sensitive to airflow at an equivalent frequency between 0.2 and 0.6 Hz. A mathematical model for the simulation of draught was established and a computer program was developed for simulating the draught. The program

Aneurysm of the superficial femoral artery in an infant

Energy Technology Data Exchange (ETDEWEB)

Watanabe, M.; Komuro, H.; Matoba, K.; Kaneko, M. [Dept. of Paediatric Surgery, Inst. of Clinical Medicine, Univ. of Tsukuba, Ibaraki (Japan); Niitsu, M.; Itai, Y. [Dept. of Radiology, Inst. of Clinical Medicine, Univ. of Tsukuba, Ibaraki (Japan)

2003-04-01

An isolated arterial aneurysm in childhood is extremely rare. We report a 1-year-old girl with an aneurysm of the right superficial femoral artery, presenting as an asymptomatic mass of the thigh. The aneurysm involved the whole superficial femoral artery (9 cm in length), and surgical treatment would have required replacement of the affected artery. Conservative treatment was chosen, influenced by the patient's rapid growth at that time. Non-invasive, 3-D contrast-enhanced magnetic resonance angiography (MRA) was useful as an alternative to conventional angiography for detailed evaluation of the femoral arteries, including the aneurysm. (orig.)

Two-phase velocity measurements around cylinders using particle image velocimetry

Energy Technology Data Exchange (ETDEWEB)

Hassan, Y.A.; Philip, O.G.; Schmidl, W.D. [Texas A& M Univ., College Station, TX (United States)] [and others

1995-09-01

The particle Image Velocimetry flow measurement technique was used to study both single-phase flow and two-phase flow across a cylindrical rod inserted in a channel. First, a flow consisting of only a single-phase fluid was studied. The experiment consisted of running a laminar flow over four rods inserted in a channel. The water flow rate was 126 cm{sup 3}/s. Then a two-phase flow was studied. A mixture of water and small air bubbles was used. The water flow rate was 378 cm{sup 3}/s and the air flow rate was approximately 30 cm{sup 3}/s. The data are analyzed to obtain the velocity fields for both experiments. After interpretation of the velocity data, forces acting on a bubble entrained by the vortex were calculated successfully. The lift and drag coefficients were calculated using the velocity measurements and the force data.

Two Crosslinking Technologies for Superficial Reticular Dermis Injection: A Comparative Ultrasound and Histologic Study

OpenAIRE

Micheels, Patrick; Besse, Stéphanie; Sarazin, Didier

2017-01-01

Background: Few hyaluronic acid fillers have been developed for superficial injection. Objective: To compare the diffusion and integration properties of cohesive polydensified matrix and Vycross® technology hyaluronic acid fillers with lidocaine following injection into the superficial reticular dermis. Methods and materials: Two subjects received two injections each of cohesive polydensified matrix and Vycross® hyaluronic acid (0.2mL/site) in the superficial reticular dermis of the buttock u...

Multiple mechanisms generate a universal scaling with dissipation for the air-water gas transfer velocity

Science.gov (United States)

Katul, Gabriel; Liu, Heping

2017-02-01

A large corpus of field and laboratory experiments support the finding that the water side transfer velocity kL of sparingly soluble gases near air-water interfaces scales as kL˜(νɛ)1/4, where ν is the kinematic water viscosity and ɛ is the mean turbulent kinetic energy dissipation rate. Originally predicted from surface renewal theory, this scaling appears to hold for marine and coastal systems and across many environmental conditions. It is shown that multiple approaches to representing the effects of turbulence on kL lead to this expression when the Kolmogorov microscale is assumed to be the most efficient transporting eddy near the interface. The approaches considered range from simplified surface renewal schemes with distinct models for renewal durations, scaling and dimensional considerations, and a new structure function approach derived using analogies between scalar and momentum transfer. The work offers a new perspective as to why the aforementioned 1/4 scaling is robust.

An Eulerian-Eulerian Approach to CFD Simulation of Two-Phase Bubble Column using ANSYS CFX Code

International Nuclear Information System (INIS)

Mohd Amirul Syafiq Mohd Yunos; Nur Khairunnisa Abd Halim; Siti Aslina Hussain

2016-01-01

Bubble columns are widely used as gas-liquid contactors and reactors in chemical, biochemical and petrochemical industries. Effective mixing, high interfacial area between phases, cheap to install and lack of moving parts are the main factors bubble column is chosen for the described processes. Understanding the complexity of the fluid dynamics of gas-liquid flow in bubble column is important due to its unsteady complex processes as well as application in the chemical and bioprocess industries. The gas-liquid of two-phase fluid flow system has been carried out to investigate the hydrodynamics parameters. An Eulerian-Eulerian approach was used to model air as the dispersed phase within a continuous phase of water using the commercial software ANSYSTM CFD software (CFX 14.0). The turbulence in the gas-liquid simulation is described by using the k-e model. This process occurs under the atmospheric pressure. The configuration of model consists of 0.2 m width, 0.2 m depth and 0.5 m height of rectangular bubble column equipped with a sparger at the bottom. Two different sparger designs, Sparger A with 4 holes and 2.6 mm diameter each and Sparger B with 81 holes and 0.5 mm diameter each are tested for three different value of superficial gas velocity of 0.0125 m/s, 0.0501 m/s and 0.0627 m/s. The volume fraction of model is described the behavior of bubble which is represented by the parameters of gas holdup, contact surface area and gas superficial velocity. The simulation was verified by comparing the two different model results. Comparison of simulation results with the experimental work data has provided a successful validation of the model. Results shows the contact surface area increasing with behavior of bubble and gas holdup increases with increasing superficial gas velocity but independent of the sparger design at high superficial velocity (>0.05 m/s). The highest value obtained which is represented of water superficial velocity, gas holdup and superficial gas

Malignant transformation of superficial peritoneal endometriosis lesion.

Science.gov (United States)

Marchand, Eva; Hequet, Delphine; Thoury, Anne; Barranger, Emmanuel

2013-08-26

A 63-year-old woman with no medical history underwent an abdominal surgery with hysterectomy and bilateral salpingo-oophorectomy for a 10 cm peritoneal cyst with increased cancer antigene-125. A large suspicious tumour of the Douglas space, with contact to the uterus and the rectal wall was described. The rest of the exploration was normal, specially the rest of the peritoneum. Histopathology revealed a malignant transformation of a superficial peritoneal endometriosis. Secondary surgery was thus completed by laparoscopy with bilateral pelvic and para-aortic lymph node dissections, omentectomy and multiple peritoneal biopsies. All staging samples were free of cancer; therefore no complementary therapy was administered. After 18 months of follow-up, consisting of clinical examination and pelvis magnetic resonance imaging every 6 months, we did not observe any recurrence. Malignant transformation of superficial peritoneal endometriosis is a rare disease and surgical management seems to be the main treatment.

Castelli di carta. La piega per la costruzione di superfici articolate

Directory of Open Access Journals (Sweden)

Andrea Casale

2012-06-01

Full Text Available L’antica arte del piegare la carta, l’Origami, sta vivendo un rinnovato interesse che coinvolge molti aspetti della ricerca.  Con il termine origami, si intende lo studio del modo di piegare il foglio di carta per imporgli una specifica forma.  La superficie tassellata per mezzo di specifiche pieghe, si propone come un nuovo soggetto di studio: la superficie piegata articolata. La forma congiunta al movimento, assume un particolare interesse nella contemporanea ricerca geometrica e architettonica. Il panorama contemporaneo, propone opere di architettura “responsiva”, capaci di modificare le proprie caratteristiche per adeguarsi a nuove condizioni. La superficie piegata articolata sembra particolarmente adatta a descrivere questo modo d’intendere l’architettura, reagendo a diverse volontà e di conseguenza modificando la propria conformazione attraverso un attento controllo progettuale della forma.

Valoración de la superficie del dializador en la hemodiafiltración on-line. Elección objetiva de la superficie del dializador

Directory of Open Access Journals (Sweden)

Francisco Maduell

2015-05-01

Conclusión: El incremento del 40% y el 80% de la superficie conlleva un aumento del volumen convectivo de un 6 y un 16% respectivamente, aunque se evidenció una reducción en su máximo rendimiento, mostrando mínimas diferencias tanto en el volumen convectivo como en la capacidad depurativa cuando el CUF era superior a 45 ml/h/mmHg. Es recomendable optimizar el rendimiento de los dializadores a la mínima superficie posible adecuando la prescripción de tratamiento.

Analysis of the air flow generated by an air-assisted sprayer equipped with two axial fans using a 3D sonic anemometer.

Science.gov (United States)

García-Ramos, F Javier; Vidal, Mariano; Boné, Antonio; Malón, Hugo; Aguirre, Javier

2012-01-01

The flow of air generated by a new design of air assisted sprayer equipped with two axial fans of reversed rotation was analyzed. For this goal, a 3D sonic anemometer has been used (accuracy: 1.5%; measurement range: 0 to 45 m/s). The study was divided into a static test and a dynamic test. During the static test, the air velocity in the working vicinity of the sprayer was measured considering the following machine configurations: (1) one activated fan regulated at three air flows (machine working as a traditional sprayer); (2) two activated fans regulated at three air flows for each fan. In the static test 72 measurement points were considered. The location of the measurement points was as follow: left and right sides of the sprayer; three sections of measurement (A, B and C); three measurement distances from the shaft of the machine (1.5 m, 2.5 m and 3.5 m); and four measurement heights (1 m, 2 m, 3 m and 4 m). The static test results have shown significant differences in the module and the vertical angle of the air velocity vector in function of the regulations of the sprayer. In the dynamic test, the air velocity was measured at 2.5 m from the axis of the sprayer considering four measurement heights (1 m, 2 m, 3 m and 4 m). In this test, the sprayer regulations were: one or two activated fans; one air flow for each fan; forward speed of 2.8 km/h. The use of one fan (back) or two fans (back and front) produced significant differences on the duration of the presence of wind in the measurement point and on the direction of the air velocity vector. The module of the air velocity vector was not affected by the number of activated fans.

Superficial fungal infections.

Science.gov (United States)

Schwartz, Robert A

Superficial fungal infections arise from a pathogen that is restricted to the stratum corneum, with little or no tissue reaction. In this Seminar, three types of infection will be covered: tinea versicolor, piedra, and tinea nigra. Tinea versicolor is common worldwide and is caused by Malassezia spp, which are human saprophytes that sometimes switch from yeast to pathogenic mycelial form. Malassezia furfur, Malassezia globosa, and Malassezia sympodialis are most closely linked to tinea versicolor. White and black piedra are both common in tropical regions of the world; white piedra is also endemic in temperate climates. Black piedra is caused by Piedraia hortae; white piedra is due to pathogenic species of the Trichosporon genus. Tinea nigra is also common in tropical areas and has been confused with melanoma.

Experimental study on airflow fluctuation characteristic of an underfloor air supply terminal unit

Energy Technology Data Exchange (ETDEWEB)

Liu, Jinping [School of Electric Power, South China University of Technology, Guangzhou 510640 (China); State Key Laboratory of Subtropical Building Science, South China University of Technology, Guangzhou 510640 (China); Wu, Yanfang [Design Institute of Guangzhou Metro Corporation, Guangzhou 510010 (China)

2010-11-15

In order to investigate dynamic characteristic of underfloor air supply terminal unit, an IFV900A hot-wire anemometer was used to measure the corresponding velocity field. Turbulence intensity and power spectrum density exponent of air velocity signal were analyzed. The result showed that the outlet velocity distribution of underfloor air supply terminal unit was uniform. With increment of height, the velocity distribution trends to be uniform. Two velocity attenuation regions appear during airflow development. Turbulence intensity changes obviously with height. It is lower than that of mechanical wind. Turbulence intensity goes up with the increment of jetting distance. Power spectrum density exponent trends to the value of natural wind with increase of jetting distance and decrease of wind velocity. The exponent value approaches to the value of typical natural wind for the air velocity is 0.5 m/s under high supply air rate. With airflow diffusion, the fluctuation characteristic of airflow varies obviously with the jetting direction. The fluctuation characteristic of airflow changes to that of natural wind with the increase of height which can improve comfort of indoor environment. (author)

Air cooled turbine component having an internal filtration system

Science.gov (United States)

Beeck, Alexander R [Orlando, FL

2012-05-15

A centrifugal particle separator is provided for removing particles such as microscopic dirt or dust particles from the compressed cooling air prior to reaching and cooling the turbine blades or turbine vanes of a turbine engine. The centrifugal particle separator structure has a substantially cylindrical body with an inlet arranged on a periphery of the substantially cylindrical body. Cooling air enters centrifugal particle separator through the separator inlet port having a linear velocity. When the cooling air impinges the substantially cylindrical body, the linear velocity is transformed into a rotational velocity, separating microscopic particles from the cooling air. Microscopic dust particles exit the centrifugal particle separator through a conical outlet and returned to a working medium.

Experiments on the superficial irradiation of spherical vegetables and fruits

International Nuclear Information System (INIS)

Kalman, B.; Kiraly, Z.

1974-01-01

A revolving facility was made for the homogeneous superficial irradiation of spherical vegetables and fruits (apricot, peach, tomato, apple, etc.) with fast electrons. After the building of the technological apparatus described in detail, dosimetrical measurements were carried out by a Van de Graff generator of 2 MV and it was proved, that the superficial irradiation had a smaller effect on the quality of the fresh fruits, than of the stored ones. The developed apparatus can be altered according to the ripe-rate of the products. (K.A.)

Tracers of air-sea gas exchange

International Nuclear Information System (INIS)

Liss, P.S.

1988-01-01

The flux of gas across the air-sea interface is determined by the product of the interfacial concentration difference driving the exchange and a rate constant, often termed the transfer velocity. The concentration-difference term is generally obtained by direct measurement, whereas more indirect approaches are required to estimate the transfer velocity and its variation as a function of controlling parameters such as wind and sea state. Radioactive tracers have proved particularly useful in the estimation of air-sea transfer velocities and, recently, stable purposeful tracers have also started to be used. In this paper the use of the following tracers to determine transfer velocities at the sea surface is discussed: natural and bomb-produced 14 C, dissolved oxygen, 222 Rn and sulphur hexafluoride. Other topics covered include the relation between transfer velocity and wind speed as deduced from tracer and wind-tunnel studies, and the discrepancy between transfer velocities determined by using tracers and from eddy correlation measurements in the atmosphere. (author)

Threshold friction velocity influenced by wetness of soils within the Columbia Plateau

Science.gov (United States)

Windblown dust impacts air quality in the Columbia Plateau of the U.S. Pacific Northwest. Wind erosion of agricultural lands, which is the predominate source of windblown dust in the region, occurs when the friction velocity exceeds the threshold friction velocity (TFV) of the surface. Soil moisture...

Augmentation of forced flow boiling heat transfer by introducing air flow into subcooled water flow

International Nuclear Information System (INIS)

Koizumi, Y.; Ohtake, H.; Yuasa, T.; Matsushita, N.

2001-01-01

The effect of air injection into a subcooled water flow on boiling heat transfer and a critical heat flux (CHF) was examined experimentally. Experiments were conducted in the range of subcooling of 50 K, a superficial velocity of water and air Ul = 0.17 ∼ 3.4 and Ug = 0 ∼ 15 m/s, respectively. A test heat transfer surface was a 5 mm wide, 40 mm long and 0.5 mm thick stainless steel sheet embedded on the bottom wall of a 10 mm high and 20 mm wide rectangular flow channel. Nine times enhancement of the heat transfer coefficient in the non-boiling region was attained at the most by introducing an air flow into a water single-phase flow. The heat transfer improvement was prominent when the water flow rate was low and the air introduction was large. The present results of the non-boiling heat transfer were well correlated with the Lockhart-Martinelli parameter X tt ; h TP /h L0 = 5.0(1/ X tt ) 0.5 . The air introduction has some effect on the augmentation of heat transfer in the boiling region, however, the two-phase flow effect was little and the boiling was dominant in the fully developed boiling region. The CHF was improved a little by the air introduction in the high water flow region. However, that was rather greatly reduced in the low flow region. Even so, the general trend by the air introduction was that qCHF increased as the air introduction was increased. The heat transfer augmentation in the non-boiling region was attained by less power increase than that in the case that only the water flow rate was increased. From the aspect of the power consumption and the heat transfer enhancement, the small air introduction in the low water flow rate region seemed more profitable, although the air introduction in the high water flow rate region and also the large air introduction were still effective in the augmentation of the heat transfer in the non-boiling region. (author)

Two-phase flow regimes for counter-current air-water flows in narrow rectangular channels

International Nuclear Information System (INIS)

Kim, Byong Joo; Sohn, Byung Hu; Jeong, Si Young

2001-01-01

A study of counter-current two-phase flow in narrow rectangular channels has been performed. Two-phase flow regimes were experimentally investigated in a 760 mm long and 100 mm wide test section with 2.0 and 5.0 mm gap widths. The resulting flow regime maps were compared with the existing transition criteria. The experimental data and the transition criteria of the models showed relatively good agreement. However, the discrepancies between the experimental data and the model predictions of the flow regime transition became pronounced as the gap width increased. As the gap width increased the transition gas superficial velocities increased. The critical void fraction for the bubbly-to-slug transition was observed to be about 0.25. The two-phase distribution parameter for the slug flow was larger for the narrower channel. The uncertainties in the distribution parameter could lead to a disagreement in slug-to-churn transition between the experimental findings and the transition criteria. For the transition from churn to annular flow the effect of liquid superficial velocity was found to be insignificant

The spatial filtering method for solid particle velocity measurement based on an electrostatic sensor

International Nuclear Information System (INIS)

Xu, Chuanlong; Tang, Guanghua; Zhou, Bin; Wang, Shimin

2009-01-01

The spatial filtering method for particle velocity measurement has the advantages of simplicity of the measurement system and convenience of data processing. In this paper, the relationship between solid particles mean velocity in a pneumatic pipeline and the power spectrum of the output signal of an electrostatic sensor was mathematically modeled. The effects of the length of the sensor, the thickness of the dielectric pipe and its length on the spatial filtering characteristics of the sensor were also investigated using the finite element method. As for the roughness of and the difficult determination of the peak frequency f max of the power spectrum characteristics of the output signal of the sensor, a wavelet analysis based filtering method was applied to smooth the curve, which can accurately determine the peak frequency f max . Finally, experiments were performed on a pilot dense phase pneumatic conveying rig at high pressure to test the performance of the velocity measurement system. The experimental results show that the system repeatability is within ±4% over a gas superficial velocity range of 8.63–18.62 m s −1 for a particle concentration range of 0.067–0.130 m 3 m −3

Development of Hydroxyl Tagging Velocimetry for Low Velocity Flows

Science.gov (United States)

Andre, Matthieu A.; Bardet, Philippe M.; Burns, Ross A.; Danehy, Paul M.

2016-01-01

Hydroxyl tagging velocimetry (HTV) is a molecular tagging technique that relies on the photo-dissociation of water vapor into OH radicals and their subsequent tracking using laser induced fluorescence. Velocities are then obtained from time-of-flight calculations. At ambient temperature in air, the OH species lifetime is relatively short (<50 µs), making it suited for high speed flows. Lifetime and radicals formation increases with temperature, which allows HTV to also probe low-velocity, high-temperature flows or reacting flows such as flames. The present work aims at extending the domain of applicability of HTV, particularly towards low-speed (<10 m/s) and moderate (<500 K) temperature flows. Results are compared to particle image velocimetry (PIV) measurements recorded in identical conditions. Single shot and averaged velocity profiles are obtained in an air jet at room temperature. By modestly raising the temperature (100-200 degC) the OH production increases, resulting in an improvement of the signal-to-noise ratio (SNR). Use of nitrogen - a non-reactive gas with minimal collisional quenching - extends the OH species lifetime (to over 500 µs), which allows probing of slower flows or, alternately, increases the measurement precision at the expense of spatial resolution. Instantaneous velocity profiles are resolved in a 100degC nitrogen jet (maximum jet-center velocity of 6.5 m/s) with an uncertainty down to 0.10 m/s (1.5%) at 68% confidence level. MTV measurements are compared with particle image velocimetry and show agreement within 2%.

Measurement and simulation of the turbulent dispersion of a radioactive tracer in a two-phase flow system

Energy Technology Data Exchange (ETDEWEB)

Hensel, F; Rohde, U

1998-10-01

The turbulent dispersion of a radiotracer in an experimental setup with a natural convection liquid-gaseous flow was investigated. A liquid-gaseous bubbly flow was generated in a narrow tank by injection of pressurized air into water or by catalytic disintegration of H{sub 2}O{sub 2}. Turbulent Prandtl numbers for gas and tracer dispersion were varied. In the case of higher gas superficial velocities (J{sub gas}{approx}5-15 mm/s), a reasonable agreement was achieved between calculated and measured tracer transport velocity and dispersion coefficient values. A nearly linear correlation between j{sub gas} and D was found in agreement with other authors. The calculation results contribute to a better understanding of the phenomena and interpretation of the measurement results as well as to the validation of the CFD code for turbulent two-phase flow applications. Further investigations are necessary to improve the agreement in the cases of H{sub 2}O{sub 2} disintegration and low gas superficial velocities. (orig.)

Measurement and simulation of the turbulent dispersion of a radioactive tracer in a two-phase flow system

International Nuclear Information System (INIS)

Hensel, F.; Rohde, U.

1998-01-01

The turbulent dispersion of a radiotracer in an experimental setup with a natural convection liquid-gaseous flow was investigated. A liquid-gaseous bubbly flow was generated in a narrow tank by injection of pressurized air into water or by catalytic disintegration of H 2 O 2 . Turbulent Prandtl numbers for gas and tracer dispersion were varied. In the case of higher gas superficial velocities (J gas ∼5-15 mm/s), a reasonable agreement was achieved between calculated and measured tracer transport velocity and dispersion coefficient values. A nearly linear correlation between j gas and D was found in agreement with other authors. The calculation results contribute to a better understanding of the phenomena and interpretation of the measurement results as well as to the validation of the CFD code for turbulent two-phase flow applications. Further investigations are necessary to improve the agreement in the cases of H 2 O 2 disintegration and low gas superficial velocities. (orig.)

Evaluating optimal superficial limb perfusion at different angles using non-invasive micro-lightguide spectrophotometry.

Science.gov (United States)

Darmanin, Geraldine; Jaggard, Matthew; Hettiaratchy, Shehan; Nanchahal, Jagdeep; Jain, Abhilash

2013-06-01

It is common practice to elevate the limbs postoperatively to reduce oedema and hence optimise perfusion and facilitate rehabilitation. However, elevation may be counterproductive as it reduces the mean perfusion pressure. There are no clear data on the optimal position of the limbs even in normal subjects. The optimal position of limbs was investigated in 25 healthy subjects using a non-invasive micro-lightguide spectrophotometry system "O2C", which indirectly measures skin and superficial tissue perfusion through blood flow, oxygen saturation and relative haemoglobin concentration. We found a reduction in skin and superficial tissue blood flow of 17% (p=0.0001) on arm elevation (180° shoulder flexion) as compared to heart level and an increase in skin and superficial tissue blood flow of 25% (p=0.02) on forearm elevation of 45°. Lower limb skin and superficial tissue blood flow decreased by 15% (p=0.004) on elevation to 47 cm and by 70% on dependency (p=0.0001) compared to heart level. However, on elevation of the lower limb there was also a 28% reduction in superficial venous pooling (p=0.0001) compared to heart level. In the normal limb, the position for optimal superficial perfusion of the upper limb is with the arm placed at heart level and forearm at 45°. In the lower limb the optimal position for superficial perfusion would be at heart level. However, some degree of elevation may be useful if there is an element of venous congestion. Copyright © 2013 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Multi-objective optimization design of air distribution of grate cooler by entropy generation minimization and genetic algorithm

International Nuclear Information System (INIS)

Shao, Wei; Cui, Zheng; Cheng, Lin

2016-01-01

Highlights: • A multi-objective optimization model of air distribution of grate cooler by genetic algorithm is proposed. • Pareto Front is obtained and validated by comparing with operating data. • Optimal schemes are compared and selected by engineering background. • Total power consumption after optimization decreases 61.10%. • Thickness of clinker on three grate plates is thinner. - Abstract: The cooling air distributions of grate cooler exercise a great influence on the clinker cooling efficiency and power consumption of cooling fans. A multi-objective optimization model of air distributions of grate cooler with cross-flow heat exchanger analogy is proposed in this paper. Firstly, thermodynamic and flow models of clinker cooling process is carried out. Then based on entropy generation minimization analysis, modified entropy generation numbers caused by heat transfer and pressure drop are chosen as objective functions respectively which optimized by genetic algorithm. The design variables are superficial velocities of air chambers and thicknesses of clinker layers on different grate plates. A set of Pareto optimal solutions which two objectives are optimized simultaneously is achieved. Scattered distributions of design variables resulting in the conflict between two objectives are brought out. The final optimal air distribution and thicknesses of clinker layers are selected from the Pareto optimal solutions based on power consumption of cooling fans minimization and validated by measurements. Compared with actual operating scheme, the total air volumes of optimized schemes decrease 2.4%, total power consumption of cooling fans decreases 61.1% and the outlet temperature of clinker decreases 122.9 °C which shows a remarkable energy-saving effect on energy consumption.

CFD model of air movement in ventilated facade: comparison between natural and forced air flow

Energy Technology Data Exchange (ETDEWEB)

Mora Perez, Miguel; Lopez Patino, Gonzalo; Lopez Jimenez, P. Amparo [Hydraulic and Environmental Engineering Department, Universitat Politècnica de Valencia (Spain)

2013-07-01

This study describes computational fluid dynamics (CFD) modeling of ventilated facade. Ventilated facades are normal facade but it has an extra channel between the concrete wall and the (double skin) facade. Several studies found in the literature are carried out with CFD simulations about the behavior of the thermodynamic phenomena of the double skin facades systems. These studies conclude that the presence of the air gap in the ventilated facade affects the temperature in the building skin, causing a cooling effect, at least in low-rise buildings. One of the most important factors affecting the thermal effects of ventilated facades is the wind velocity. In this contribution, a CFD analysis applied on two different velocity assumptions for air movement in the air gap of a ventilated facade is presented. A comparison is proposed considering natural wind induced velocity with forced fan induced velocity in the gap. Finally, comparing temperatures in the building skin, the differences between both solutions are described determining that, related to the considered boundary conditions, there is a maximum height in which the thermal effect of the induced flow is significantly observed.

The Effect of Wind Velocity on the Cooling Rate of Water

OpenAIRE

Shrey Aryan

2016-01-01

The effect of wind velocity on the cooling rate of water was investigated by blowing air horizontally over the surface of water contained in a plastic water-bottle cap. The time taken for the temperature to fall to the average of the surrounding and initial temperatures was recorded at different values of wind velocity. It was observed that on increasing the wind velocity, the time taken to achieve average temperature not only decreased but also remained the same after a certain point.

Interfacial area transport of bubbly flow in a small diameter pipe

International Nuclear Information System (INIS)

Hibiki, Takashi; Takamasa, Tomoji; Ishii, Mamoru

2001-01-01

In relation to the development of the interfacial area transport equation, this study focused on modeling of the interfacial area transport mechanism of vertical adiabatic air-water bubbly flows in a relatively small diameter pipe where the bubble size-to-pipe diameter ratio was relatively high and the radial motion of bubbles was restricted by the presence of the pipe wall. The sink term of the interfacial area concentration was modeled by considering wake entrainment as a possible bubble coalescence mechanism, whereas the source term was neglected by assuming negligibly small bubble breakup for low liquid velocity conditions based on visual observation. One-dimensional interfacial area transport equation with the derived sink term was evaluated by using five datasets of vertical adiabatic air-water bubbly flows measured in a 9.0 mm-diameter pipe (superficial gas velocity: 0.013-0.052 m/s, superficial liquid velocity: 0.58-1.0 m/s). The modeled interfacial area transport equation could reproduce the proper trend of the axial interfacial area transport and predict the measured interfacial area concentrations within an average relative deviation of ±11.1%. It was recognized that the present model would be promising for predicting the interfacial area transport of the examined bubbly flows. (author)

MOSFET dosimetry in-vivo at superficial and orthovoltage x-ray energies

International Nuclear Information System (INIS)

Cheung, T.; Yu, P.K.N.; Butson, M.J.; Illawarra Cancer Care Centre, Wollongong, NSW

2003-01-01

This note investigates in-vivo dosimetry using a Metal Oxide Semiconductor Field Effect Transistor (MOSFET) for radiotherapy treatment at superficial and orthovoltage x-ray energies. This was performed within one fraction of the patients treatment. Standard measurements along with energy response of the detector are given. Results showed that the MOSFET measurements in-vivo agreed with calculated results on average within ± 5.6% over all superficial and orthovoltage energies. These variations were slightly larger than TLD results with variations between measured and calculated results being ± 5.0% for the same patient measurements. The MOSFET device provides adequate in-vivo dosimetry for superficial and orthovoltage energy treatments with the accuracy of the measurements seeming to be relatively on par with TLD in our case. The MOSFET does have the advantage of returning a relatively immediate dosimetric result after irradiation. Copyright (2003) Australasian College of Physical Scientists and Engineers in Medicine

Use of superficial peroneal nerve graft for treating peripheral nerve injuries

Directory of Open Access Journals (Sweden)

Samuel Ribak

2016-02-01

Full Text Available ABSTRACT OBJECTIVE: To evaluate the clinical results from treating chronic peripheral nerve injuries using the superficial peroneal nerve as a graft donor source. METHODS: This was a study on eleven patients with peripheral nerve injuries in the upper limbs that were treated with grafts from the sensitive branch of the superficial peroneal nerve. The mean time interval between the dates of the injury and surgery was 93 days. The ulnar nerve was injured in eight cases and the median nerve in six. There were three cases of injury to both nerves. In the surgery, a longitudinal incision was made on the anterolateral face of the ankle, thus viewing the superficial peroneal nerve, which was located anteriorly to the extensor digitorum longus muscle. Proximally, the deep fascia between the extensor digitorum longus and the peroneal longus muscles was dissected. Next, the motor branch of the short peroneal muscle (one of the branches of the superficial peroneal nerve was identified. The proximal limit of the sensitive branch was found at this point. RESULTS: The average space between the nerve stumps was 3.8 cm. The average length of the grafts was 16.44 cm. The number of segments used was two to four cables. In evaluating the recovery of sensitivity, 27.2% evolved to S2+, 54.5% to S3 and 18.1% to S3+. Regarding motor recovery, 72.7% presented grade 4 and 27.2% grade 3. There was no motor deficit in the donor area. A sensitive deficit in the lateral dorsal region of the ankle and the dorsal region of the foot was observed. None of the patients presented complaints in relation to walking. CONCLUSIONS: Use of the superficial peroneal nerve as a graft source for treating peripheral nerve injuries is safe and provides good clinical results similar to those from other nerve graft sources.

Real-time approaches to the estimation of local wind velocity for a fixed-wing unmanned air vehicle

International Nuclear Information System (INIS)

Chan, W L; Lee, C S; Hsiao, F B

2011-01-01

Three real-time approaches to estimating local wind velocity for a fixed-wing unmanned air vehicle are presented in this study. All three methods work around the navigation equations with added wind components. The first approach calculates the local wind speed by substituting the ground speed and ascent rate data given by the Global Positioning System (GPS) into the navigation equations. The second and third approaches utilize the extended Kalman filter (EKF) and the unscented Kalman filter (UKF), respectively. The results show that, despite the nonlinearity of the navigation equations, the EKF performance is proven to be on a par with the UKF. A time-varying noise estimation method based on the Wiener filter is also discussed. Results are compared with the average wind speed measured on the ground. All three approaches are proven to be reliable with stated advantages and disadvantages

Air-water flow measurement for ERVC conditions by LIF/PIV

International Nuclear Information System (INIS)

Yoon, Jong Woong; Jeong, Yong Hoon

2016-01-01

Critical heat flux (CHF) of the external reactor vessel wall is a safety limit that indicate the integrity of the reactor vessel during the situation. Many research conducted CHF experiments in the IVR-ERVC conditions. However, the flow velocity field which is an important factor in the CHF mechanism were not studied enough in the IVR-ERVC situations. In this study, flow measurements including velocity vector field and the liquid velocity in the IVR-ERVC conditions were studied. The air-water two phase flow loop simulating IVRERVC conditions was set up and liquid velocity field was measured by LIF/PIV technique in this study. The experiment was conducted with and without air injection conditions. For the air-water flow experiment, liquid velocity at the outside of two phase boundary layer became higher and the two phase boundary layer thickness became smaller when the mass flux increases. The velocity data obtained in this study are expected to improve the CHF correlation in the IVR-ERVC situations.

Air-water flow measurement for ERVC conditions by LIF/PIV

Energy Technology Data Exchange (ETDEWEB)

Yoon, Jong Woong; Jeong, Yong Hoon [KAIST, Daejeon (Korea, Republic of)

2016-05-15

Critical heat flux (CHF) of the external reactor vessel wall is a safety limit that indicate the integrity of the reactor vessel during the situation. Many research conducted CHF experiments in the IVR-ERVC conditions. However, the flow velocity field which is an important factor in the CHF mechanism were not studied enough in the IVR-ERVC situations. In this study, flow measurements including velocity vector field and the liquid velocity in the IVR-ERVC conditions were studied. The air-water two phase flow loop simulating IVRERVC conditions was set up and liquid velocity field was measured by LIF/PIV technique in this study. The experiment was conducted with and without air injection conditions. For the air-water flow experiment, liquid velocity at the outside of two phase boundary layer became higher and the two phase boundary layer thickness became smaller when the mass flux increases. The velocity data obtained in this study are expected to improve the CHF correlation in the IVR-ERVC situations.

Superficies in the form of the right to superpose

Directory of Open Access Journals (Sweden)

Simona CHIRICĂ

2015-06-01

Full Text Available The purpose of this paper is to present the current legal framework related to the superficies right in the form of the right to superpose, and especially to draw the attention and put certain question marks regarding the actuality or even the urgency of the need for regulation regarding the right to superpose. First, as a preliminary aspect, in order to emphasize the historical evolution of the superficies right, we will briefly present the development of this concept starting from the Roman law up to the present date. Second, by analysing the relevant legislation, the doctrine and the jurisprudence, the authors set themselves to present the main methods for constituting the superficies right. Third, the characteristics related to the right to superpose will be correlatively laid out. Fourth, the possibility to obtain a building permit on the basis of the right to superpose will also be analysed. Fifth, the recently entered-into-force legislative framework regarding the registration of the right to superpose and of the building thus erected is presented. Last but not least, the conclusions of this paper are presented, highlighting the necessity for more clearly defined rules regulating the legal status of the right to superpose, in order to avoid any confusions and inconsistencies in practice.

Estudio comparativo de la rugosidad superficial en cerámicas de ultra baja fusión

OpenAIRE

Ccahuana Vásquez, Vanessa Zulema; Leite de Oliveira Morais, Andréia Alves; Sussumu Nishioka, Renato; Tomomitsu Kimpara, Estevão

2015-01-01

El objetivo de este trabajo fue comparar la rugosidad superficial en cerámicas de baja y ultra baja fusión, después del pulido mecánico y exposición a un medio corrosivo in vitro. El análisis de la superficie (Ra) fue realizado con un rugosímetro. Se confeccionaron 72 discos, divididos en cuatro grupos según el sistema cerámico utilizado: VitadurAplha (G1), Titankeramik (G2), HeraCeram (G3) y Finesse (G4), y según el tratamiento de superficie: (A) especímenes sin tratamiento de superficie. (B...

Use your eyes - metallographic versus superficial traces of the crafting of Bronze Age ornaments

DEFF Research Database (Denmark)

Nørgaard, Heide Wrobel

and superficial archaeological examinations can be used to understand prehistoric craft. Furthermore, it will show that with an intensive knowledge about previous scientific investigations the superficial traces preserved can reveal a great amount of information and could talk for themselves. Taking as an example...... the early and middle Bronze Age bronze ornaments from North Germany, superficial traces of the metal crafting process, visible with the naked eye, will be compared with metallographic images. The aim of this presentation is to give an overview over the crafting traces everybody could see (with a bit...

A Computational and Experimental Study of Coflow Laminar Methane/Air Diffusion Flames: Effects of Fuel Dilution, Inlet Velocity, and Gravity

Science.gov (United States)

Cao, S.; Ma, B.; Bennett, B. A. V.; Giassi, D.; Stocker, D. P.; Takahashi, F.; Long, M. B.; Smooke, M. D.

2014-01-01

The influences of fuel dilution, inlet velocity, and gravity on the shape and structure of laminar coflow CH4-air diffusion flames were investigated computationally and experimentally. A series of nitrogen-diluted flames measured in the Structure and Liftoff in Combustion Experiment (SLICE) on board the International Space Station was assessed numerically under microgravity (mu g) and normal gravity (1g) conditions with CH4 mole fraction ranging from 0.4 to 1.0 and average inlet velocity ranging from 23 to 90 cm/s. Computationally, the MC-Smooth vorticity-velocity formulation was employed to describe the reactive gaseous mixture, and soot evolution was modeled by sectional aerosol equations. The governing equations and boundary conditions were discretized on a two-dimensional computational domain by finite differences, and the resulting set of fully coupled, strongly nonlinear equations was solved simultaneously at all points using a damped, modified Newton's method. Experimentally, flame shape and soot temperature were determined by flame emission images recorded by a digital color camera. Very good agreement between computation and measurement was obtained, and the conclusions were as follows. (1) Buoyant and nonbuoyant luminous flame lengths are proportional to the mass flow rate of the fuel mixture; computed and measured nonbuoyant flames are noticeably longer than their 1g counterparts; the effect of fuel dilution on flame shape (i.e., flame length and flame radius) is negligible when the flame shape is normalized by the methane flow rate. (2) Buoyancy-induced reduction of the flame radius through radially inward convection near the flame front is demonstrated. (3) Buoyant and nonbuoyant flame structure is mainly controlled by the fuel mass flow rate, and the effects from fuel dilution and inlet velocity are secondary.

The Effect of Wind Velocity on the Cooling Rate of Water

Directory of Open Access Journals (Sweden)

Shrey Aryan

2016-01-01

Full Text Available The effect of wind velocity on the cooling rate of water was investigated by blowing air horizontally over the surface of water contained in a plastic water-bottle cap. The time taken for the temperature to fall to the average of the surrounding and initial temperatures was recorded at different values of wind velocity. It was observed that on increasing the wind velocity, the time taken to achieve average temperature not only decreased but also remained the same after a certain point.

Study of the mechanisms involved in the laser superficial hardening process of metallic alloys; Estudo dos mecanismos envolvidos no processo de endurecimento superficial a laser de ligas metalicas

Energy Technology Data Exchange (ETDEWEB)

Silva, Edmara Marques Rodrigues da

2001-07-01

The laser superficial hardening process of a ferrous alloy (gray cast iron) and of an aluminum-silicon alloy was investigated in this work. These metallic alloys are used in the automobile industry for manufacturing cylinders and pistons, respectively. By application of individual pulses and single tracks, the involved mechanisms during the processing were studied. Variables such as energy density, power density, temporal width, beam diameter on the sample surface, atmosphere of the processing region, overlapping and scanning velocity. The hardened surface was characterized by optical and scanning electronic microscopy, dispersive energy microanalysis, X-ray mapping, X-ray diffraction, and measurements of roughness and Vickers microhardness. Depending on the processing parameters, it is possible to obtain different microstructures. The affected area of gray cast iron, can be hardened by remelting or transformation hardening (total or partial) if the reached temperature is higher or not that of melting temperature. Laser treatment originated new structures such as retained austenite, martensite and, occasionally, eutectic of cellular dendritic structure. Aluminum-silicon alloy does not have phase transformation in solid state, it can be hardened only by remelting. The increase of hardness is a function of the precipitation hardening process, which makes the silicon particles smaller and more disperse in the matrix. Maximal values of microhardness (700-1000 HV) were reached with the laser treatment in gray cast iron samples. The initial microhardness is of 242 HV. For aluminum-silicon alloy, the laser remelting increases the initial microhardness of 128 HV to the range of 160-320 HV. The found results give a new perspective for using the CLA/IPEN's laser in the heat treatment area. Besides providing a higher absorptivity to the materials, compared with the CO{sub 2} laser, and optical fiber access, the superficial hardening with Nd:YAG laser, depending on the

Intravesical Gemcitabine for Treatment of Superficial Bladder ...

African Journals Online (AJOL)

Objectives: Intravesical Bacillus Calmette-Guérin (BCG) vaccine is the mainstay of treatment and prophylaxis in superficial bladder cancer (SBC) as it reduces tumor recurrence and disease progression. About one-third of patients do not respond to BCG. The aim of this study was to determine the efficacy of intravesical ...

An experimental investigation on the velocity fluctuation characteristics in a triple air jet

International Nuclear Information System (INIS)

Nam, Ho Yun; Kim, Jong Man; Choi, Jong Hyeon; Choi, Seok Ki

2005-01-01

The thermal striping which occurs due to a turbulent thermal mixing in the upper plenum of a liquid metal reactor causes a temperature fluctuation on the adjacent solid materials and it is an important parameter in the design of a liquid metal reactor. An experimental apparatus which is a mock up of the fuel assembly in the liquid metal reactor is devised, and the average velocity and the velocity fluctuation in a two-dimensional jet from three nozzles are measured. In the present paper the characteristics of the velocity fluctuation which is used for a validation of a thermal hydraulic computer code is described

Effect of pore water pressure on P-wave velocity in water-filled sands with partial air saturation; Fukanzen howa jotai no suna shiryo wo denpasuru P ha sokudo ni oyobosu kangeki suiatsu no eikyo

Energy Technology Data Exchange (ETDEWEB)

Kanema, T [Chishitsu-Keisoku Co. Ltd., Tokyo (Japan)

1997-10-22

With an objective to elucidate change in velocity of elastic waves in association with water pressure increase in a sand bed below the groundwater level in a shallow portion of the ground, a measurement experiment was carried out on P-wave velocity in sand samples with partial air saturation. The experiment has used fine sand having an equivalent coefficient of 2.40, a soil particle density of 2.68 g/cm {sup 3} or 60%, and a grain size of 0.36 mm. Inside the water-filled sand sample, two accelerometers were embedded 20 cm apart from each other as vibration receivers. An electromagnetic hammer for P-wave was used as the vibration source. In the experiment, measurement was carried out on the P-wave velocity in association with increase in pore water pressure by applying water pressure afresh to the water-filled sample. As a result of the experiment, the following matters were disclosed: the P-wave velocity increases as the pore water pressure was increased, and a phenomenon was recognized that the dominant frequency changes into high frequency; the degree of increase in the P-wave velocity varies depending on initial saturation of the sample; and bubbles in the pore fluid have their volume decreased due to compression resulted from increased pore water pressure and dissolution of air into the pore water. 6 refs., 11 figs.

Study of pressure drop, void fraction and relative permeabilities of two phase flow through porous media

International Nuclear Information System (INIS)

Chu, W.; Dhir, V.K.; Marshall, J.

1983-01-01

An experimental investigation of two phase flow through porous layers formed of non-heated glass particles (nominal diameter 1 to 6 mm) has been made. Particulate bed depths of 30 cm and 70 cm were used. The effect of particle size, particle size distribution and bed porosity on void fraction and pressure drop through a particulate bed formed in a cylindrical test section has been investigated. The superficial velocity of liquid (water) is varied from 1.83 to 18.3 mm/s while the superficial velocity of gas (air) is varied from 0 to 68.4 mm/s. These superficial velocities were chosen so that pressure drop and void fraction measurement could be made for the porous layer in fixed and fluidized states. A model based on drift flux approach has been developed for the void fraction. Using the two phase friction pressure drop data, the relative permeabilities of the two phases have been concluded with void fraction. The void fraction and two phase friction pressure gradient in beds composed of mixtures of spherical particles as well as sharps of different nominal sizes have also been examined. It is found that the models for single size particles are also applicable to mixtures of particles if a mean particle diameter for the mixture is defined

Doppler-shifted fluorescence imaging of velocity fields in supersonic reacting flows

Science.gov (United States)

Allen, M. G.; Davis, S. J.; Kessler, W. J.; Sonnenfroh, D. M.

1992-01-01

The application of Doppler-shifted fluorescence imaging of velocity fields in supersonic reacting flows is analyzed. Focussing on fluorescence of the OH molecule in typical H2-air Scramjet flows, the effects of uncharacterized variations in temperature, pressure, and collisional partner composition across the measurement plane are examined. Detailed measurements of the (1,0) band OH lineshape variations in H2-air combustions are used, along with single-pulse and time-averaged measurements of an excimer-pumped dye laser, to predict the performance of a model velocimeter with typical Scramjet flow properties. The analysis demonstrates the need for modification and control of the laser bandshape in order to permit accurate velocity measurements in the presence of multivariant flow properties.

Calibration techniques for the hot wire anemometer in a low velocity region

International Nuclear Information System (INIS)

Fujimura, Kaoru; Kawamura, Hiroshi

1980-03-01

In connection with experiments on coolant flow in the core of multi-purpose VHTR, a low-velocity calibration wind tunnel was made, and techniques for the hot wire anemometer in the air were investigated. Following are the results. 1) A technique using the frequency of von Karman vortex street is not recommended because of the irregular mode in a low velocity region. 2) A Pitot tube is valid only for the flow velocities larger than 1 m/s. 3) The thermal trace technique is suitable in a relatively wide range of velocity, if velocity defect in the wake is compensated for. When flow velocity is larger than 1 m/s, the thermal trace technique is consistent with the Pitot tube method. (author)

Devolatilization of oil sludge in a lab-scale bubbling fluidized bed.

Science.gov (United States)

Liu, Jianguo; Jiang, Xiumin; Han, Xiangxin

2011-01-30

Devolatilization of oil sludge pellets was investigated in nitrogen and air atmosphere in a lab-scale bubbling fluidized bed (BFB). Devolatilization times were measured by the degree of completion of the evolution of the volatiles for individual oil sludge pellets in the 5-15 mm diameter range. The influences of pellet size, bed temperature and superficial fluidization velocity on devolatilization time were evaluated. The variation of devolatilization time with particle diameter was expressed by the correlation, τ(d) = Ad(p)(N). The devolatilization time to pellet diameter curve shows nearly a linear increase in nitrogen, whereas an exponential increase in air. No noticeable effect of superficial fluidization velocity on devolatilization time in air atmosphere was observed. The behavior of the sludge pellets in the BFB was also focused during combustion experiments, primary fragmentation (a micro-explosive combustion phenomenon) was observed for bigger pellets (>10mm) at high bed temperatures (>700 °C), which occurred towards the end of combustion and remarkably reduce the devolatilization time of the oil sludge pellet. The size analysis of bed materials and fly ash showed that entire ash particle was entrained or elutriated out of the BFB furnace due to the fragile structure of oil sludge ash particles. Copyright © 2010 Elsevier B.V. All rights reserved.

Vascular patterns of upper limb: an anatomical study with accent on superficial brachial artery

Directory of Open Access Journals (Sweden)

David Kachlik

2011-02-01

Full Text Available The aim of the study was to evaluate the terminal segmentation of the axillary artery and to present four cases of anomalous branching of the axillary artery, the superficial brachial artery (arteria brachialis superficialis, which is defined as the brachial artery that runs superficially to the median nerve. Totally, 130 cadaveric upper arms embalmed by classical formaldehyde technique from collections of the Department of Anatomy, Third Faculty of Medicine, Charles University in Prague, were macroscopically dissected with special focus on the branching arrangement of the axillary artery. The most distal part of the axillary artery (infrapectoral part terminated in four cases as a bifurcation into two terminal branches: the superficial brachial artery and profunda brachii artery, denominated according to their relation to the median nerve. The profunda brachii artery primarily gave rise to the main branches of the infrapectoral part of the axillary artery. The superficial brachial artery descended to the cubital fossa where it assumed the usual course of the brachial artery in two cases and in the other two cases its branches (the radial and ulnar arteries passed superficially to the flexors. The incidence of the superficial brachial artery in our study was 5% of cases. The reported incidence is a bit contradictory, from 0.12% to 25% of cases. The anatomical knowledge of the axillary region is of crucial importance for neurosurgeons and specialists using the radiodiagnostic techniques, particularly in cases involving traumatic injuries. The improved knowledge would allow more accurate diagnostic interpretations and surgical treatment.

The drift velocity monitoring system of the CMS barrel muon chambers

CERN Document Server

Altenhoefer, Georg Friedrich; Heidemann, Carsten Andreas; Reithler, Hans; Sonnenschein, Lars; Teyssier, Daniel Francois

2017-01-01

The drift velocity is a key parameter of drift chambers. Its value depends on several parameters: electric field, pressure, temperature, gas mixture, and contamination, for example, by ambient air. A dedicated Velocity Drift Chamber (VDC) with 1-L volume has been built at the III. Phys. Institute A, RWTH Aachen, in order to monitor the drift velocity of all CMS barrel muon Drift Tube chambers. A system of six VDCs was installed at CMS and has been running since January 2011. We present the VDC monitoring system, its principle of operation, and measurements performed.

The drift velocity monitoring system of the CMS barrel muon chambers

Science.gov (United States)

Altenhöfer, Georg; Hebbeker, Thomas; Heidemann, Carsten; Reithler, Hans; Sonnenschein, Lars; Teyssier, Daniel

2018-04-01

The drift velocity is a key parameter of drift chambers. Its value depends on several parameters: electric field, pressure, temperature, gas mixture, and contamination, for example, by ambient air. A dedicated Velocity Drift Chamber (VDC) with 1-L volume has been built at the III. Phys. Institute A, RWTH Aachen, in order to monitor the drift velocity of all CMS barrel muon Drift Tube chambers. A system of six VDCs was installed at CMS and has been running since January 2011. We present the VDC monitoring system, its principle of operation, and measurements performed.

Caracterizacion dosimetrica del equipo de Terapia Superficial Therapax del Hospital Mexico

International Nuclear Information System (INIS)

Bernui De Vivanco, Maria Giselle; Rojas Rivas, Jorge; Cardenas Retuerto, Augusto

2007-01-01

The Servicio de Radioterapia of the Hospital Mexico in San Jose, Costa Rica has a Superficial Therapy equipment Therapax model DXT 300. It describes the measurements for the dosimetric characterization of the configurations 100 kVp, 25 mA and filter of 2.4 mm of Al, and 250 kVp, 10 mA and filter of 2.5 mm of Cu, taking into account that the uncertainties in the measurements of the superficial therapy equipment are higher than in the rank of the megavoltage [es

Dynamic response of SWEMAAIR 300 thermal anemometer with SWA-01 velocity transducer

Energy Technology Data Exchange (ETDEWEB)

Melikov, A K; Popiolek, Z

1996-06-01

The objective of this study is to identify the dynamic response of the SwemaAir 300 thermal anemometer to downward airflow with different amplitude and frequency of the velocity fluctuations and changing direction. An important aim is to find to what extend the accuracy of the velocity measurements is effected at the above described conditions. (au)

Comportamiento a fatiga del acero sae 4140 usando alta rugosidad superficial y ambiente corrosivo

OpenAIRE

CEBALLOS, WILSON FERNANDO; GÓMEZ, ADOLFO LEÓN; CORONADO, JOHN JAIRO

2010-01-01

En este artículo se presenta el estudio del comportamiento a fatiga del acero SAE 4140 en condiciones diferentes: superficie pulida (acabado espejo), ambiente corrosivo (jugo de caña de azúcar), alta rugosidad superficial (superficie equivalente a la encontrada típicamente en los ejes de molino de caña) y una condición que involucra la combinación de las dos últimas. Las anteriores condiciones están presentes en los ejes de maza de molino de caña de azúcar durante el proceso de molienda. Se r...

COMPORTAMIENTO A FATIGA DEL ACERO SAE 4140 USANDO ALTA RUGOSIDAD SUPERFICIAL Y AMBIENTE CORROSIVO

OpenAIRE

CEBALLOS, WILSON FERNANDO; GÓMEZ, ADOLFO LEÓN; CORONADO, JOHN JAIRO

2010-01-01

En este artículo se presenta el estudio del comportamiento a fatiga del acero SAE 4140 en condiciones diferentes: superficie pulida (acabado espejo), ambiente corrosivo (jugo de caña de azúcar), alta rugosidad superficial (superficie equivalente a la encontrada típicamente en los ejes de molino de caña) y una condición que involucra la combinación de las dos últimas. Las anteriores condiciones están presentes en los ejes de maza de molino de caña de azúcar durante el proceso de molienda. Se r...

Isolated core vs. superficial cooling effects on virtual maze navigation.

Science.gov (United States)

Payne, Jennifer; Cheung, Stephen S

2007-07-01

Cold impairs cognitive performance and is a common occurrence in many survival situations. Altered behavior patterns due to impaired navigation abilities in cold environments are potential problems in lost-person situations. We investigated the separate effects of low core temperature and superficial cooling on a spatially demanding virtual navigation task. There were 12 healthy men who were passively cooled via 15 degrees C water immersion to a core temperature of 36.0 degrees C, then transferred to a warm (40 degrees C) water bath to eliminate superficial shivering while completing a series of 20 virtual computer mazes. In a control condition, subjects rested in a thermoneutral (approximately 35 degrees C) bath for a time-matched period before being transferred to a warm bath for testing. Superficial cooling and distraction were achieved by whole-body immersion in 35 degree water for a time-matched period, followed by lower leg immersion in 10 degree C water for the duration of the navigational tests. Mean completion time and mean error scores for the mazes were not significantly different (p > 0.05) across the core cooling (16.59 +/- 11.54 s, 0.91 +/- 1.86 errors), control (15.40 +/- 8.85 s, 0.82 +/- 1.76 errors), and superficial cooling (15.19 +/- 7.80 s, 0.77 +/- 1.40 errors) conditions. Separately reducing core temperature or increasing cold sensation in the lower extremities did not influence performance on virtual computer mazes, suggesting that navigation is more resistive to cooling than other, simpler cognitive tasks. Further research is warranted to explore navigational ability at progressively lower core and skin temperatures, and in different populations.

Burning velocity measurements of nitrogen-containing compounds.

Science.gov (United States)

Takizawa, Kenji; Takahashi, Akifumi; Tokuhashi, Kazuaki; Kondo, Shigeo; Sekiya, Akira

2008-06-30

Burning velocity measurements of nitrogen-containing compounds, i.e., ammonia (NH3), methylamine (CH3NH2), ethylamine (C2H5NH2), and propylamine (C3H7NH2), were carried out to assess the flammability of potential natural refrigerants. The spherical-vessel (SV) method was used to measure the burning velocity over a wide range of sample and air concentrations. In addition, flame propagation was directly observed by the schlieren photography method, which showed that the spherical flame model was applicable to flames with a burning velocity higher than approximately 5 cm s(-1). For CH3NH2, the nozzle burner method was also used to confirm the validity of the results obtained by closed vessel methods. We obtained maximum burning velocities (Su0,max) of 7.2, 24.7, 26.9, and 28.3 cm s(-1) for NH3, CH3NH2, C2H5NH2, and C3H7NH2, respectively. It was noted that the burning velocities of NH3 and CH3NH2 were as high as those of the typical hydrofluorocarbon refrigerants difluoromethane (HFC-32, Su0,max=6.7 cm s(-1)) and 1,1-difluoroethane (HFC-152a, Su0,max=23.6 cm s(-1)), respectively. The burning velocities were compared with those of the parent alkanes, and it was found that introducing an NH2 group into hydrocarbon molecules decreases their burning velocity.

Functional compartmentalization of the human superficial masseter muscle.

Directory of Open Access Journals (Sweden)

Rodrigo A Guzmán-Venegas

Full Text Available Some muscles have demonstrated a differential recruitment of their motor units in relation to their location and the nature of the motor task performed; this involves functional compartmentalization. There is little evidence that demonstrates the presence of a compartmentalization of the superficial masseter muscle during biting. The aim of this study was to describe the topographic distribution of the activity of the superficial masseter (SM muscle's motor units using high-density surface electromyography (EMGs at different bite force levels. Twenty healthy natural dentate participants (men: 4; women: 16; age 20±2 years; mass: 60±12 kg, height: 163±7 cm were selected from 316 volunteers and included in this study. Using a gnathodynamometer, bites from 20 to 100% maximum voluntary bite force (MVBF were randomly requested. Using a two-dimensional grid (four columns, six electrodes located on the dominant SM, EMGs in the anterior, middle-anterior, middle-posterior and posterior portions were simultaneously recorded. In bite ranges from 20 to 60% MVBF, the EMG activity was higher in the anterior than in the posterior portion (p-value = 0.001.The center of mass of the EMG activity was displaced towards the posterior part when bite force increased (p-value = 0.001. The topographic distribution of EMGs was more homogeneous at high levels of MVBF (p-value = 0.001. The results of this study show that the superficial masseter is organized into three functional compartments: an anterior, a middle and a posterior compartment. However, this compartmentalization is only seen at low levels of bite force (20-60% MVBF.

[Occupational trauma due to superficial corneal foreign body].

Science.gov (United States)

Gerente, Vanessa Miroski; Melo, Gustavo Barreto de; Regatieri, Caio Vinícius Saito; Alvarenga, Lênio Souza; Martins, Elizabeth Nogueira

2008-01-01

To evaluate the epidemiology of superficial corneal foreign body. Patients who were seen at the Emergency Service of the Federal University of São Paulo, from April/05 to June/05, were screened and those with superficial corneal foreign body were interviewed. Data regarding gender, age, occupation, employment status, availability and use of protective devices and supervision of their use were collected. Awareness of the possible complications was also assessed. Results were analyzed using chi-square or Fisher exact test. One hundred twenty-three patients were interviewed. Only 3 patients were female. The mean age was 36 years. Most injuries occurred at the workplace (86.2%), and 58.4% of the patients did not have a legal employment registration. The occupational activities most frequently reported were construction related activities (44.3%) and welding/soldering (11.3%). In most workplaces (79.8%) protective devices were available and 85.3% of the patients were instructed to use them. A safety device was being used during the accident in 34.2% of the cases and this was more frequent among patients that had legal employment registry (p=0.008) and among those under supervision (p=0.0415). The majority of the patients (68.9%) were aware of the risk of severe complications. Most patients with superficial corneal foreign body are aware of its severe complications and injuries usually occur in places where safety devices are available and often during their use. Our findings suggest that prevention should focus on supervision and correct use of safety devices.

Clinicomycological Characterization of Superficial Mycoses from a Tertiary Care Hospital in Nepal

OpenAIRE

Khadka, Sundar; Sherchand, Jeevan Bahadur; Pokharel, Dinesh Binod; Pokhrel, Bharat Mani; Mishra, Shyam Kumar; Dhital, Subhash; Rijal, Basista

2016-01-01

Background. Superficial mycosis is a common fungal infection worldwide, mainly caused by dermatophytes. However, the prevalence of species varies geographically. In addition, fungal treatment is best guided according to species isolated. This study was carried out to determine the clinical as well as mycological profile of superficial mycoses in a tertiary care hospital, Nepal. Methods. This was a prospective case-control laboratory based study conducted over a period of six months from Janua...

Topographical anatomy of superficial veins, cutaneous nerves, and arteries at venipuncture sites in the cubital fossa.

Science.gov (United States)

Mikuni, Yuko; Chiba, Shoji; Tonosaki, Yoshikazu

2013-01-01

We investigated correlations among the superficial veins, cutaneous nerves, arteries, and venous valves in 128 cadaveric arms in order to choose safe venipuncture sites in the cubital fossa. The running patterns of the superficial veins were classified into four types (I-IV) and two subtypes (a and b). In types I and II, the median cubital vein (MCV) was connected obliquely between the cephalic and basilic veins in an N-shape, while the median antebrachial vein (MAV) opened into the MCV in type I and into the basilic vein in type II. In type III, the MCV did not exist. In type IV, additional superficial veins above the cephalic and basilic veins were developed around the cubital fossa. In types Ib-IVb, the accessory cephalic vein was developed under the same conditions as seen in types Ia-IVa, respectively. The lateral cutaneous nerve of the forearm descended deeply along the cephalic vein in 124 cases (97 %), while the medial cutaneous nerve of the forearm descended superficially along the basilic vein in 94 (73 %). A superficial brachial artery was found in 27 cases (21 %) and passed deeply under the ulnar side of the MCV. A median superficial antebrachial artery was found in 1 case (1 %), which passed deeply under the ulnar side of the MCV and ran along the MAV. Venous valves were found at 239 points in 28 cases with superficial veins, with a single valve seen at 79 points (33 %) and double valves at 160 points (67 %). At the time of intravenous injection, caution is needed regarding the locations of cutaneous nerves, brachial and superficial brachial arteries, and venous valves. The area ranging from the middle segment of the MCV to the confluence between the MCV and cephalic vein appears to be a relatively safe venipuncture site.

Managment of superficial infantile capillary hemangiomas with topical timolol maleate solution.

Science.gov (United States)

Rizvi, Syed Ali Raza; Yusuf, Faraz; Sharma, Rajeev; Rizvi, Syed Wajahat Ali

2015-01-01

Capillary hemangioma is the most common benign tumor of eyelids and orbit in children. Recently, a topical beta blocker has been reported as an effective treatment for superficial capillary hemangiomas. We present a case report of two children having large capillary hemangiomas who responded well to topical treatment by 0.5% timolol maleate solution. After 12 months of treatment, the lesion has significantly reduced in size, thickness, and color in both cases. Thus, we conclude that long-term use of topical 0.5% timolol maleate solution is safe and effective in treating superficial capillary hemangiomas.

Detailed pressure drop measurements in single-and two-phase adiabatic air-water turbulent flows in realistic BWR fuel assembly geometry with spacer grids

International Nuclear Information System (INIS)

Caraghiaur, Diana; Frid, Wiktor; Tillmark, Nils

2004-01-01

In recent years, advance numerical simulation tools based on CFD methods have been increasingly used in various multi-phase flow applications. One of these is two-phase flow in fuel assemblies of Boiling Water Reactors. The important and often missing aspect of this development is validation of CFD codes against proper experimental data. The purpose of the current paper is to present detailed pressure measurements over a spacer grid in low pressure adiabatic single- and bubbly two-phase flow, which will be used to further develop a CFD code for BWR fuel bundle analysis. The experiments have been carried out in a n asymmetric 24-rod sub-bundle, representing one quarter of a Westinghouse SVEA-96 nuclear reactor fuel assembly. Single-phase flow measurements have been performed at superficial velocities between 0.90-4.50 m/s and in the two-phase flow, which was simulated by air-water mixture, measurements have been performed at void fractions ranging from 4 to 12% and liquid superficial velocity of 4.50 m/s. In order to increase the number of measuring points, five pressure taps were drilled in one of the rods, which was easily moved vertically by a traversing system, covering most of the points in axial direction. Any of the rods in the bundle could be substitute by the pressure sensing rod and the measurements were made for five pressure taps facing-angles. A detailed pressure distribution comparison between single- and two-phase flows for different sub-channel positions and different flow conditions was performed over one of the spacers. In addition, single-phase pressure drop measurements in the upper part of the test section comprising two spacer grids have been carried out. (author)

Mensuration of the propagation speed of mixed flames of Methane-air and gas natural, Guajira - air using the method of the angle of the cone

International Nuclear Information System (INIS)

Benjumea Hernandez, Pedro Nel; Higuita Bedoya Carlos Mario; Cordoba Perez, Camilo Andres

2004-01-01

In this work, the burning velocity of premixed laminar flames of methane-air and Guajira natural gas-air mixtures was measured by the cone's angle method using a cylindrical Bunsen burner. In the development of the experiments, a fuel concentration in the fuel-air mixture ranging from 9% -11% was taken. The maximum value of the burning velocity was obtained for mixtures a little bit richer than the stoichiometric case. For methane, this flame velocity was 44.1 cm/s and for the Guajira natural gas was 43.1 cm/s. From the results, it was possible to see that the Guajira natural gas inert content led to a burning velocity value lesser than the methane's, in spite of the Guajira natural gas having a higher heavy hydrocarbon content. Methane burning velocity values following similar trends to those reported by the literature were obtained. The systematic error found in the results is mainly a consequence of inaccuracies in the method used to measure the fuel-gas mixture velocity at the burner exit

Air distribution and ventilation effectiveness in an occupied room heated by warm air

DEFF Research Database (Denmark)

Krajcik, Michal; Simone, Angela; Olesen, Bjarne W.

2012-01-01

and at different simulated outside conditions, internal heat gains and air change rates. Floor heating was also simulated and compared with the warm air heating system. Vertical air temperature profiles, air velocity profiles and equivalent temperatures were derived in order to describe the thermal environment...... floor heating system was simulated, the cooler ventilation air introduced to the room mixed well and created uniform conditions with a ventilation effectiveness of about 1.......Air distribution, ventilation effectiveness and thermal environment were experimentally studied in a simulated room in a low-energy building heated and ventilated by warm air supplied by a mixing ventilation system. Measurements were performed for various positions of the air terminal devices...

Investigation of the behaviour of a LILW superficial repository under aircraft impact

International Nuclear Information System (INIS)

Lo Frano, Rosa; Stefanini, Lorenzo

2016-01-01

Highlights: • Safety assessment of a LILW superficial repository. • Investigation of the consequences of an aircraft impact with fuel burning. • Experimental material properties. • Numerical simulation of aircraft impact with fuel burning accident by MSC.MARC"© code. • Demonstration that the overall integrity resulted is guaranteed. - Abstract: Safety and security are the two fundamental aspects to guarantee when designing a LILW superficial repository. Because of its safety concern, we have to prove, and build confidence in, the primary and secondary consequences of the crashing will be acceptable. These goals are obtained generally by means of safety assessment supported by calculations. This study is intended to investigate the performance of a superficial repository subjected to aircraft impact and fuel burning. To the purpose a superficial repository similar to that of El Cabril has been considered. Moreover to be confident the facility is safe and that the consequences of such a type of accident on the environment and humans are negligible, an appropriate safety assessment was carried out. The potential damage that aircraft impact could bring into the repository has been therefore analysed and discussed. To attain the intent load functions, calculated according to the Riera approach, and the maximum temperature reached by fuel during its combustion have been considered. FEM (thermo-mechanical) simulations have been done, by MSC"© Marc code, assuming damaging phenomena of concrete and material properties variation with the temperature. The obtained results showed that an empty superficial repository with a wall thickness, ranging from 0.7 to 1 m, is not sufficient to avoid penetration. Nevertheless even in presence of a reduced strength and of (cone) cracking and plugging, the overall integrity resulted guaranteed.

Investigation of the behaviour of a LILW superficial repository under aircraft impact

Energy Technology Data Exchange (ETDEWEB)

Lo Frano, Rosa, E-mail: rosa.lofrano@ing.unipi.it; Stefanini, Lorenzo

2016-04-15

Highlights: • Safety assessment of a LILW superficial repository. • Investigation of the consequences of an aircraft impact with fuel burning. • Experimental material properties. • Numerical simulation of aircraft impact with fuel burning accident by MSC.MARC{sup ©} code. • Demonstration that the overall integrity resulted is guaranteed. - Abstract: Safety and security are the two fundamental aspects to guarantee when designing a LILW superficial repository. Because of its safety concern, we have to prove, and build confidence in, the primary and secondary consequences of the crashing will be acceptable. These goals are obtained generally by means of safety assessment supported by calculations. This study is intended to investigate the performance of a superficial repository subjected to aircraft impact and fuel burning. To the purpose a superficial repository similar to that of El Cabril has been considered. Moreover to be confident the facility is safe and that the consequences of such a type of accident on the environment and humans are negligible, an appropriate safety assessment was carried out. The potential damage that aircraft impact could bring into the repository has been therefore analysed and discussed. To attain the intent load functions, calculated according to the Riera approach, and the maximum temperature reached by fuel during its combustion have been considered. FEM (thermo-mechanical) simulations have been done, by MSC{sup ©} Marc code, assuming damaging phenomena of concrete and material properties variation with the temperature. The obtained results showed that an empty superficial repository with a wall thickness, ranging from 0.7 to 1 m, is not sufficient to avoid penetration. Nevertheless even in presence of a reduced strength and of (cone) cracking and plugging, the overall integrity resulted guaranteed.

MR-angiogram-added surface anatomy scanning of superficial cerebral arteriovenous malformations

Energy Technology Data Exchange (ETDEWEB)

Tsuchiya, Kazuhiro; Katase, Shichiro; Yoshino, Ayako; Hachiya, Junichi [Department of Radiology, Kyorin University School of Medicine, 6-20-2, Shinkawa, Mitaka, Tokyo 181-8611 (Japan); Shiokawa, Yoshiaki [Department of Neurosurgery, Kyorin University School of Medicine, 6-20-2, Shinkawa, Mitaka, Tokyo 181-8611 (Japan)

2002-09-01

Our purpose was to evaluate the utility of surface anatomy scanning (SAS) of the brain with superimposition of MR angiograms in the diagnosis and presurgical planning of superficial cerebral arteriovenous malformations (AVMs). We performed SAS in 15 patients with superficial cerebral AVMs. Two-dimensional phase-contrast MR angiograms were then obtained in the same section and superimposed on the SAS images. The images were assessed regarding the visualization of each AVM component using a four-point grading scale (3=excellent to 0=poor). In 13 of the patients, the assessment was made comparing with conventional angiograms. The images were also compared with the surgical findings in 5 patients. The added images agreed well with the angiographic findings and demonstrated the relationships between the AVM components and the adjacent brain surface. The average scores of the feeder(s), nidus, and drainer(s) were 2.27, 2.33, and 2.67, respectively. The surgical findings also correlated well with the added images. Our technique can noninvasively demonstrate superficial AVMs along with the brain surface and provide information useful for planning surgery. (orig.)

MR-angiogram-added surface anatomy scanning of superficial cerebral arteriovenous malformations

International Nuclear Information System (INIS)

Tsuchiya, Kazuhiro; Katase, Shichiro; Yoshino, Ayako; Hachiya, Junichi; Shiokawa, Yoshiaki

2002-01-01

Our purpose was to evaluate the utility of surface anatomy scanning (SAS) of the brain with superimposition of MR angiograms in the diagnosis and presurgical planning of superficial cerebral arteriovenous malformations (AVMs). We performed SAS in 15 patients with superficial cerebral AVMs. Two-dimensional phase-contrast MR angiograms were then obtained in the same section and superimposed on the SAS images. The images were assessed regarding the visualization of each AVM component using a four-point grading scale (3=excellent to 0=poor). In 13 of the patients, the assessment was made comparing with conventional angiograms. The images were also compared with the surgical findings in 5 patients. The added images agreed well with the angiographic findings and demonstrated the relationships between the AVM components and the adjacent brain surface. The average scores of the feeder(s), nidus, and drainer(s) were 2.27, 2.33, and 2.67, respectively. The surgical findings also correlated well with the added images. Our technique can noninvasively demonstrate superficial AVMs along with the brain surface and provide information useful for planning surgery. (orig.)

Total uncertainty of low velocity thermal anemometers for measurement of indoor air movements

DEFF Research Database (Denmark)

Jørgensen, F.; Popiolek, Z.; Melikov, Arsen Krikor

2004-01-01

For a specific thermal anemometer with omnidirectional velocity sensor the expanded total uncertainty in measured mean velocity Û(Vmean) and the expanded total uncertainty in measured turbulence intensity Û(Tu) due to different error sources are estimated. The values are based on a previously...... developed mathematical model of the anemometer in combination with a large database of representative room flows measured with a 3-D Laser Doppler anemometer (LDA). A direct comparison between measurements with a thermal anemometer and a 3-D LDA in flows of varying velocity and turbulence intensity shows...... good agreement not only between the two instruments but also between the thermal anemometer and its mathematical model. The differences in the measurements performed with the two instruments are all well within the measurement uncertainty of both anemometers....

Myxoid stroma and delicate vasculature of a superficial angiomyxoma give rise to the red planet sign

OpenAIRE

Green, Margaret; Logemann, Nichola; Sulit, Daryl J

2014-01-01

Superficial angiomyxomas are uncommon benign mesenchymal tumors. They often recur locally if partially removed. This case report demonstrates not only the characteristic pathological findings of a superficial angiomyxoma in a 33- year-old man, but also shows a unique dermatoscopic image, which in our estimation resembles a celestial red planet such as the blood moon seen during a lunar eclipse. We propose to call this the “red planet” sign for a superficial angiomyxoma on dermoscopic examinat...

Myxoid stroma and delicate vasculature of a superficial angiomyxoma give rise to the red planet sign.

Science.gov (United States)

Green, Margaret; Logemann, Nichola; Sulit, Daryl J

2014-09-16

Superficial angiomyxomas are uncommon benign mesenchymal tumors. They often recur locally if partially removed. This case report demonstrates not only the characteristic pathological findings of a superficial angiomyxoma in a 33- year-old man, but also shows a unique dermatoscopic image, which in our estimation resembles a celestial red planet such as the blood moon seen during a lunar eclipse. We propose to call this the "red planet" sign for a superficial angiomyxoma on dermoscopic examination.

Velocity Field Measurements of Human Coughing Using Time Resolved Particle Image Velocimetry

Science.gov (United States)

Khan, T.; Marr, D. R.; Higuchi, H.; Glauser, M. N.

2003-11-01

Quantitative fluid mechanics analysis of human coughing has been carried out using new Time Resolved Particle Image Velocimetry (TRPIV). The study involves measurement of velocity vector time-histories and velocity profiles. It is focused on the average normal human coughing. Some work in the past on cough mechanics has involved measurement of flow rates, tidal volumes and sub-glottis pressure. However, data of unsteady velocity vector field of the exiting highly time-dependent jets is not available. In this study, human cough waveform data are first acquired in vivo using conventional respiratory instrumentation for various volunteers of different gender/age groups. The representative waveform is then reproduced with a coughing/breathing simulator (with or without a manikin) for TRPIV measurements and analysis. The results of this study would be useful not only for designing of indoor air quality and heating, ventilation and air conditioning systems, but also for devising means of protection against infectious diseases.

Interdigital foot infections: Corynebacterium minutissimum and agents of superficial mycoses

Directory of Open Access Journals (Sweden)

Fatma Mutlu Sariguzel

2014-09-01

Full Text Available Interdigital foot infections are mostly caused initially by dermatophytes, yeasts and less frequently by bacteria. Erythrasma caused by Corynebacterium minutissimum can be confused with superficial mycoses. The aim of the study was to determine the prevalence of the etiologic agents of superficial mycoses and the frequency of Corynebacterium minutissimum in interdigital foot infections. All the samples obtained from the 121 patients with interdigital foot infections were examined directly with the use of 20% potassium hydroxide mounts and Gram stain under the microscope and cultured on Sabouraud's dextrose agar plates. In identification of superficial mycoses, the rate was found to be 14% with the cultural method and 14% with direct microscopic examination. Using a combination of direct microscopic examination and culture, a 33.8% ratio was achieved. In the culture of these samples, the most isolated factor was Trichophyton rubrum (33.7%. In 24 of the patients (19.8% Corynebacterium minutissimum was detected by Gram staining, in 6 of these patients Trichophyton rubrum was found, Trichophyton mentagrophytes was found in 2 and Trichosporon spp. was found in 1. The examination of interdigital foot lesions in the laboratory, the coexistence of erythrasma with dermatophytes and yeast should be considered.

Bacterias en superficies contactadas durante las tomas radiográficas intraorales

OpenAIRE

Lee, Guihan; Calderón-Ubaquí, Victor; Sacsaquispe-Contreras, Sonia

2016-01-01

Objetivo: Determinar la presencia de bacterias mediante el análisis microbiológico en las superficies contactadas por el operador durante la toma y procesado de radiografías intraorales en diferentes momentos del día en el Servicio de Radiología Oral de la UPCH. Materiales y métodos: Se realizó un muestreo en nueve superficies del servicio de radiología oral. Las muestras se tomaron en dos momentos por el mismo investigador; al inicio y al finalizar las actividades en el servicio, se realizó ...

Building America Case Study: Standard- Versus High-Velocity Air Distribution in High-Performance Townhomes, Denver, Colorado

Energy Technology Data Exchange (ETDEWEB)

2017-06-09

IBACOS investigated the performance of a small-diameter high velocity heat pump system compared to a conventional system in a new construction triplex townhouse. A ductless heat pump system also was installed for comparison, but the homebuyer backed out because of aesthetic concerns about that system. In total, two buildings, having identical solar orientation and comprised of six townhomes, were monitored for comfort and energy performance. Results show that the small-diameter system provides more uniform temperatures from floor to floor in the three-story townhome. No clear energy consumption benefit was observed from either system. The builder is continuing to explore the small-diameter system as its new standard system to provide better comfort and indoor air quality. The homebuilder also explored the possibility of shifting its townhome product to meet the U.S. Department of Energy Challenge Home National Program Requirements. Ultimately, the builder decided that adoption of these practices would be too disruptive midstream in the construction cycle. However, the townhomes met the ENERGY STAR Version 3.0 program requirements.

Induction of superficial cortical layer neurons from mouse embryonic stem cells by valproic acid.

Science.gov (United States)

Juliandi, Berry; Abematsu, Masahiko; Sanosaka, Tsukasa; Tsujimura, Keita; Smith, Austin; Nakashima, Kinichi

2012-01-01

Within the developing mammalian cortex, neural progenitors first generate deep-layer neurons and subsequently more superficial-layer neurons, in an inside-out manner. It has been reported recently that mouse embryonic stem cells (mESCs) can, to some extent, recapitulate cortical development in vitro, with the sequential appearance of neurogenesis markers resembling that in the developing cortex. However, mESCs can only recapitulate early corticogenesis; superficial-layer neurons, which are normally produced in later developmental periods in vivo, are under-represented. This failure of mESCs to reproduce later corticogenesis in vitro implies the existence of crucial factor(s) that are absent or uninduced in existing culture systems. Here we show that mESCs can give rise to superficial-layer neurons efficiently when treated with valproic acid (VPA), a histone deacetylase inhibitor. VPA treatment increased the production of Cux1-positive superficial-layer neurons, and decreased that of Ctip2-positive deep-layer neurons. These results shed new light on the mechanisms of later corticogenesis. Copyright © 2011 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

Visualization of two-phase gas-liquid flow regimes in horizontal and slightly-inclined circular tubes

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Livia Alves [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil); Nuclear Engineering Institute (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)], E-mail: livia@lasme.coppe.ufrj.br; Cunha Filho, Jurandyr; Su, Jian [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), RJ (Brazil). Nuclear Engineering Program], Emails: cunhafilho@lasme.coppe.ufrj.br, sujian@lasme.coppe.ufrj.br; Faccini, Jose Luiz Horacio [Nuclear Engineering Institute (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)], E-mail: faccini@ien.gov.br

2010-07-01

In this paper a flow visualization study was performed for two-phase gas-liquid flow in horizontal and slightly inclined tubes. The test section consists of a 2.54 cm inner diameter stainless steel circular tube, followed by a transparent acrylic tube with the same inner diameter. The working fluids were air and water, with liquid superficial velocities ranging from 0:11 to 3:28 m/s and gas superficial velocities ranging from 0:27 to 5:48 m/s. Flow visualization was executed for upward flow at 5 deg and 10 deg and downward flow at 2:5 deg, 5 deg and 10 deg, as well as for horizontal flow. The visualization technique consists of a high-speed digital camera that records images at rates of 125 and 250 frames per second of a concurrent air-water mixture through a transparent part of the tube. From the obtained images, the flow regimes were identified (except for annular flow), observing the effect of inclination angles on flow regime transition boundaries. Finally, the experimental results were compared with empirical and theoretical flow pattern maps available in literature. (author)

Spectral characterization of superficial coal groups

International Nuclear Information System (INIS)

Ahmad, I.; Khan, M.A.; Ishaq, M.; Shakirullah; Bahadur, A.

2004-01-01

Spectral characterization of superficial coal groups was performed in KBr pellets. KBr Pellets were prepared for virgin and variously pretreated coal samples. Spectra of satisfactory resolution were obtained in wave number range-4000-400 cm /sup -1/. Presence of broad absorption bands corresponds to hydroxyl, carbonyl, carboxyl and phenolic functionalities in the spectra clearly define their presence in all samples understudy. Forced oxidation proved effective for oxidation of both aliphatic and aromatic configurations, which can be revealed from the respective spectra. (author)

Temperature distributions in 136 superficial radiothermotherapies

International Nuclear Information System (INIS)

Willich, N.; Duve, S.; Pfluger, T.; Bachmeier, K.

1992-01-01

Temperature distributions from 136 superficial radiothermotherapies in patients were analysed and three-dimensionally reconstructed. The calculation of mean values and standard deviations of the temperature measuring probes considering water bolus temperature, master probe temperature, site of the probes relatively to different applicator positions and site of the probes in the heated tissues yielded satisfactory temperature distributions for chest wall treatment in contrast to other regions of the body. Radiothermotherapy was statistically not superior to radiotherapy alone with respect to local tumor control. (authors)

Ultrasonic Surface Measurements for the investigation of superficial alteration of natural stones

Science.gov (United States)

Meier, Thomas; Auras, Michael; Bilgili, Filiz; Christen, Sandra; Cristiano, Luigia; Krompholz, Rolf; Mosca, Ilaria; Rose, David

2013-04-01

Seismic waveform analysis is applicable also to the centimeter and decimeter scale for non-destructive testing of pavement, facades, plaster, sculptures, or load-bearing structures like pillars. Mostly transmission measurements are performed and travel-times of first arriving P-waves are considered that have limited resolution for the upper centimeters of an object. In contrast, surface measurements are well suited to quantify superficial alterations of material properties e.g. due to weathering. A number of surface measurements have been carried out in the laboratory as well as on real structures in order to study systematically the information content of ultrasonic waveforms and their variability under real conditions. As a preposition for ultrasonic waveform analysis, reproducible, broad-band measurements have to be carried out with a definite radiation pattern and an about 1 mm accuracy of the measurement geometry. We used special coupling devices for effective ultrasonic surface measurements in the laboratory as well as at real objects. Samples of concrete with varying composition and samples of natural stone - marble, tuff, and sandstone - were repeatedly weathered and tested by ultrasonic measurements. The resistance of the samples to weathering and the penetration depth of the weathering are analyzed. Furthermore, material specific calibration curves for changes in velocities of elastic waves due to weathering can be obtained by these tests. Tests on real structures have been carried out for marble (Schlossbrücke, Berlin) and sandstone (Porta Nigra, Trier). Altogether, these test measurements show clearly that despite of the internal inhomogeneity of many real objects, their surface roughness and topography especially ultrasonic Rayleigh waves are well suited to study material alterations in the upper centimeters. Dispersion of Rayleigh waves may be inverted for shear-wave velocity as a function of depth.

Air–Sea CO2 Gas Transfer Velocity in a Shallow Estuary

DEFF Research Database (Denmark)

Mørk, Eva Thorborg; Sørensen, Lise Lotte; Jensen, Bjarne

2014-01-01

The air–sea transfer velocity of CO2(kCO2) was investigated in a shallow estuary in March to July 2012, using eddy-covariance measurements of CO2 fluxes and measured air–sea CO2 partial-pressure differences. A data evaluation method that eliminates data by nine rejection criteria in order......, the transfer velocity in the shallow water estuary was lower than in other coastal waters, possibly a symptom of low tidal amplitude leading to low intensity water turbulence. High transfer velocities were recorded above wind speeds of 5 m s−1 , believed to be caused by early-breaking waves and the large fetch...... (6.5 km) of the estuary. These findings indicate that turbulence in both air and water influences the transfer velocity....

Sodium flow distribution test of the air cooler tubes

International Nuclear Information System (INIS)

Uchida, Hiroyuki; Ohta, Hidehisa; Shimazu, Hisashi

1980-01-01

In the heat transfer tubes of the air cooler which is installed in the auxiliary core cooling system of the fast breeder prototype plant reactor ''Monju'', sodium freezing may be caused by undercooling the sodium induced by an extremely unbalanced sodium flow in the tubes. Thus, the sodium flow distribution test of the air cooler tubes was performed to examine the flow distribution of the tubes and to estimate the possibility of sodium freezing in the tubes. This test was performed by using a one fourth air cooler model installed in the water flow test facility. As the test results show, the flow distribution from the inlet header to each tube is almost equal at any operating condition, that is, the velocity deviation from normalized mean velocity is less than 6% and sodium freezing does not occur up to 250% air velocity deviation at stand-by condition. It was clear that the proposed air cooler design for the ''Monju'' will have a good sodium flow distribution at any operating condition. (author)

Comparison between pulsed Nd:YAG laser superficial treatment and ceramic coating in creep test of Ti-6Al-4V alloy

International Nuclear Information System (INIS)

Reis, A.G.; Reis, D.A.P.; Moura Neto, C.; Oliveira, H.S.; Couto, A.A.

2009-01-01

The objective of this work was evaluating the creep resistance of the Ti-6Al-4V alloy with superficial treatment of pulsed Nd:YAG laser and ceramic coating in creep test of Ti-6Al-4V alloy. It was used Ti-6Al-4V alloy as cylindrical bars under forged and annealing of 190 deg C by 6 hours condition and cooled by air. The Ti-6Al-4V alloy after the superficial treatment of pulsed Nd:YAG laser and ceramic coating was submitted to creep tests at 600°C and 125 at 319 MPa, under constant load mode. In the Nd:YAG pulsed laser treatment was used an environment of 40 % N and 60 % Ar, with 2.1 W of power and 10 m/s of speed. Yttria (8 wt.%) stabilized zirconia (YSZ) with a CoNiCrAlY bond coat was atmospherically plasma sprayed on Ti-6Al-4V substrates by Sulzer Metco Type 9 MB. The obtained results suggest the laser treatment on Ti-6Al-4V alloy improved its creep resistance. (author)

Superficial Temporal Artery Pseudoaneurysm: A Conservative Approach in a Critically Ill Patient

International Nuclear Information System (INIS)

Grasso, Rosario Francesco; Quattrocchi, Carlo Cosimo; Crucitti, Pierfilippo; Carboni, Giampiero; Coppola, Roberto; Zobel, Bruno Beomonte

2007-01-01

A 71-year-old man affected by cardio- and cerebrovascular disease experienced an accidental fall and trauma to the fronto-temporal area of the head. A few weeks later a growing mass appeared on his scalp. A diagnosis of superficial temporal artery pseudoaneurysm was made following CT and color Doppler ultrasound. His clinical condition favoured a conservative approach by ultrasound-guided compression and subsequent surgical resection. A conservative approach should be considered the treatment of choice in critically ill patients affected by superficial temporal artery pseudoaneurysm

Effect of geometric parameters of liquid-gas separator units on phase separation performance

Energy Technology Data Exchange (ETDEWEB)

Mo, Songping; Chen, Xueqing; Chen, Ying [Guangdong University of Technology, Seoul (China); Yang, Zhen [Tsinghua University, Beijing (China)

2015-07-15

Five liquid-gas separator units were designed and constructed based on a new concept of a validated high-performance condenser. Each separator unit consists of two united T-junctions and an apertured baffle. The separator units have different header diameters or different baffles with different diameters of the liquid-gas separation hole. The phase separation characteristics of the units were investigated at inlet air superficial velocities from 1.0m/s to 33.0m/s and water superficial velocities from 0.0015 m/s to 0..50 m/s. The experimental results showed that the liquid height, liquid flow rate through the separation hole, and liquid separation efficiency increased with increased header diameter and decreased diameter of the separation hole. The geometric structures of the separator units affected the phase separation characteristics by influencing the liquid height in the header and the liquid flow rate through the separation hole.

Mathematical Models for Room Air Distribution

DEFF Research Database (Denmark)

Nielsen, Peter V.

1982-01-01

A number of different models on the air distribution in rooms are introduced. This includes the throw model, a model on penetration length of a cold wall jet and a model for maximum velocity in the dimensioning of an air distribution system in highly loaded rooms and shows that the amount of heat...... removed from the room at constant penetration length is proportional to the cube of the velocities in the occupied zone. It is also shown that a large number of diffusers increases the amount of heat which may be removed without affecting the thermal conditions. Control strategies for dual duct and single...... duct systems are given and the paper is concluded by mentioning a computer-based prediction method which gives the velocity and temperature distribution in the whole room....

Requirements of air conditioners for office buildings. Pt. 2

Energy Technology Data Exchange (ETDEWEB)

Radtke, W

1988-02-01

Presenting numerous explanatory diagrams part two of the report deals with auxiliary ventilation systems (mechanical systems); the influence of different ventilation circuits on the air quality (particle concentration, floor and ceiling air outlets); the requirements of heating systems (dimensioning of heating systems, effects of ventilation systems on the heat demand, reduced heat demand owing to auxiliary ventilation systems); the requirements of cooling (cooling loads in office buildings, room temperatures in the case of natural cooling, auxiliary ventilation systems, and cooling by means of refrigerators, floor/ceiling cooling systems); permissible ambient air velocities (complaints about draughts). Bottom-to-top ventilation circuits were found to provide for better air qualities and lower ambient air velocities without increasing the systems' energy demand. (HWJ).

Streamer properties and associated x-rays in perturbed air

Science.gov (United States)

Köhn, C.; Chanrion, O.; Babich, L. P.; Neubert, T.

2018-01-01

Streamers are ionization waves in electric discharges. One of the key ingredients of streamer propagation is an ambient gas that serves as a source of free electrons. Here, we explore the dependence of streamer dynamics on different spatial distributions of ambient air molecules. We vary the spatial profile of air parallel and perpendicular to the ambient electric field. We consider local sinusoidal perturbations of 5%-100%, as induced from discharge shock waves. We use a cylindrically symmetric particle-in-cell code to simulate the evolution of bidirectional streamers and compare the electron density, electric field, streamer velocity and electron energy of streamers in uniform air and in perturbed air. In all considered cases, the motion is driven along in decreasing air density and damped along increasing air density. Perturbations of at most 5%-10% change the velocity differences by up to approximately 40%. Perturbations perpendicular to the electric field additionally squeeze or branch streamers. Air variations can thus partly explain the difference of velocities and morphologies of streamer discharges. In cases with large perturbations, electrons gain energies of up to 30 keV compared to 100 eV in uniformly distributed air. For such perturbations parallel to the ambient electric field, we see the spontaneous initiation of a negative streamer; for perpendicular perturbations, x-rays with energies of up to 20 keV are emitted within 0.17 ns.

A local-velocity meter for hypersonic plasma jet

International Nuclear Information System (INIS)

Nyazev, A.A.; Lerner, N.B.; Svinolupov, K.I.

1985-01-01

This paper describes a system for a resonant laser Doppler meter for the local velocity in a hypersonic plasma flow. Preliminary test results on the prototype are reported for a jet of air containing sodium at 1100 degrees K, air pressure in the working region 20-200 Pa, and jet speed 6-8 km/sec. Measured speeds agree with theoretical predictions. The prototype and the method do not impose constraints on the working conditions but can be extended to wide ranges in temperature and pressure, such as ones in which the line width does not exceed the Doppler shift

Accuracy limitations for low velocity measurements and draft assessment in rooms

DEFF Research Database (Denmark)

Melikov, Arsen Krikor; Popiolek, Zbigniew J.; Silva, M.G.

2007-01-01

must be known in order to perform reliable assessment and validation. At present, a low-velocity thermal anemometer (LVTA) with an omnidirectional (spherical) sensor is most often used in practice for measuring air speed due to its low price and easy and convenient operation. The accuracy of the speed......, the definition of realistic requirements in thermal comfort standards as well as validation of CFD predictions is made possible.......The measurement of air temperature, mean air speed, and turbulence intensity is required in order to assess air distribution and draft discomfort in ventilated rooms. The measurements are also used for validation of computational fluid dynamics (CFD) predictions. The uncertainty of the measurements...

Esophagectomy for Superficial Esophageal Neoplasia.

Science.gov (United States)

Watson, Thomas J

2017-07-01

Endoscopic therapies have become the standard of care for most cases of Barrett's esophagus with high-grade dysplasia or intramucosal adenocarcinoma. Despite a rapid and dramatic evolution in treatment paradigms, esophagectomy continues to occupy a place in the therapeutic armamentarium for superficial esophageal neoplasia. The managing physician must remain cognizant of the limitations of endoscopic approaches and consider surgical resection when they are exceeded. Esophagectomy, performed at experienced centers for appropriately selected patients with early-stage disease can be undertaken with the expectation of cure as well as low mortality, acceptable morbidity, and good long-term quality of life. Copyright © 2017 Elsevier Inc. All rights reserved.

Propagation velocities of laser-produced plasmas from copper wire targets and water droplets

Science.gov (United States)

Song, Kyo-Dong; Alexander, Dennis R.

1994-01-01

Experiments were performed to determine the plasma propagation velocities resulting from KrF laser irradiation of copper wire target (75 microns diameter) and water droplets (75 microns diameter) at irradiance levels ranging from 25 to 150 GW/sq cm. Plasma propagation velocities were measured using a streak camera system oriented orthogonally to the high-energy laser propagation axis. Plasma velocities were studied as a function of position in the focused beam. Results show that both the shape of the plasma formation and material removal from the copper wire are different and depend on whether the targets are focused or slightly defocused (approximately = 0.5 mm movement in the beam axis). Plasma formation and its position relative to the target is an important factor in determining the practical focal point during high-energy laser interaction with materials. At irradiance of 100 GW/sq cm, the air plasma has two weak-velocity components which propagate toward and away from the incident laser while a strong-velocity component propagates away from the laser beam as a detonation wave. Comparison of the measured breakdown velocities (in the range of 2.22-2.27 x 10(exp 5) m/s) for air and the value calculated by the nonlinear breakdown wave theory at irradiance of 100 GW/sq cm showed a quantitative agreement within approximately 50% while the linear theory and Gaussian pulse theory failed. The detonation wave velocities of plasma generated from water droplets and copper wire targets for different focused cases were measured and analyzed theoretically. The propagation velocities of laser-induced plasma liquid droplets obtained by previous research are compared with current work.

Superficial Siderosis of the Central Nervous System Caused by Hemorrhagic Intraventricular Craniopharyngioma: Case Report and Literature Review

Science.gov (United States)

TOSAKA, Masahiko; SATO, Koji; AMANUMA, Makoto; HIGUCHI, Tetsuya; ARAI, Motohiro; AISHIMA, Kaoru; SHIMIZU, Tatsuya; HORIGUCHI, Keishi; SUGAWARA, Kenichi; YOSHIMOTO, Yuhei

2015-01-01

Superficial siderosis is a rare condition caused by hemosiderin deposits in the central nervous system (CNS) due to prolonged or recurrent low-grade bleeding into the cerebrospinal fluid (CSF). CNS tumor could be one of the sources of bleeding, both pre- and postoperatively. We report an extremely rare case of superficial siderosis associated with purely third ventricle craniopharyngioma, and review previously reported cases of superficial siderosis associated with CNS tumor. A 69-year-old man presented with headache, unsteady gait, blurred vision, and progressive hearing loss. Brain magnetic resonance (MR) imaging with gadolinium revealed a well enhanced, intraventricular mass in the anterior part of the third ventricle. T2*-weighted gradient echo (GE) MR imaging revealed a hypointense rim around the brain particularly marked within the depth of the sulci. Superficial siderosis was diagnosed based on these findings. The tumor was diffusely hypointense on T2*-weighted GE imaging, indicating intratumoral hemorrhage. The lateral ventricles were dilated, suggesting hydrocephalus. [18F]fluorodeoxyglucose positron emission tomography revealed increased uptake in the tumor. The whole brain surface appeared dark ocher at surgery. Histological examination showed the hemorrhagic tumor was papillary craniopharyngioma. His hearing loss progressed after removal of the tumor. T2*-weighted GE MR imaging demonstrated not only superficial siderosis but also diffuse intratumoral hemorrhage in the tumor. Superficial siderosis and its related symptoms, including hearing loss, should be considered in patients with hemorrhagic tumor related to the CSF space. Purely third ventricle craniopharyngioma rarely has hemorrhagic character, which could cause superficial siderosis and progressive hearing loss. PMID:24670310

A method for determination of the superficial charge density

International Nuclear Information System (INIS)

Vila, F.

1992-10-01

In this article is presented a new methodism for determination of superficial charge density in nonconducting materials which is based in the combination of laboratory calibrated experiments in conducting surfaces with theoretical calculations for nonconducting surfaces. (author). 19 refs, 7 figs, 1 tab

Frey′s Syndrome as a Sequela of Superficial Parotidectomy

Directory of Open Access Journals (Sweden)

Rishi Kumar Bali

2006-01-01

The disorder is characterized by unilateral sweating and flushing of facial skin in the area of parotid gland occurring during meals. We present a case of a patient who developed symptoms of Frey Syndrome 4 months after undergoing superficial parotidectomy on left side.

Treatment for superficial infusion thrombophlebitis of the upper extremity

NARCIS (Netherlands)

Di Nisio, Marcello; Peinemann, Frank; Porreca, Ettore; Rutjes, Anne W. S.

2015-01-01

Although superficial thrombophlebitis of the upper extremity represents a frequent complication of intravenous catheters inserted into the peripheral veins of the forearm or hand, no consensus exists on the optimal management of this condition in clinical practice. To summarise the evidence from

Experimental study on characteristics of interfacial parameter distribution for upward bubbly flow in inclined tube

International Nuclear Information System (INIS)

Xing Dianchuan; Yan Changqi; Sun Licheng; Liu Jingyu

2013-01-01

Experimental study on characteristics of interfacial parameter distribution for air-water bubbly flow in an inclined circular tube was performed by using the double sensor probe method. Parameters including radial distributions of local void fraction, bubble passing frequency, interfacial area concentration and bubble equivalent diameter were measured using the probe. The inner diameter of test section is 50 mm, and the liquid superficial velocity is 0.144 m/s, with the gas superficial velocity ranging from 0 to 0.054 m/is. The results show that bubbles obviously move toward the upper wall and congregate. The local interfacial area concentration, bubble passing frequency and void fraction have similar radial distribution profiles. Different from the vertical condition, for a cross-sectional area of the test section, the peak value near the upper side increases, while decreases or even disappears near the underside. The local parameter increases as the radial positions change from lower to upper location, and the increased slope becomes larger as the inclination angles increase. The equivalent bubble diameter doesn't vary with radial position, superficial gas velocity and inclination angle, and bubble aggregation and breaking up nearly doesn't occur. The mechanism of effects of inclination on local parameter distribution for bubbly flow is explained by analyzing the transverse force governing the bubble motion. (authors)

Unexpected diagnosis of superficial neurofibroma in a lesion with imaging features of a vascular malformation

Energy Technology Data Exchange (ETDEWEB)

O' Keefe, Patrick; Reid, Janet; Morrison, Stuart [Cleveland Clinic Foundation, Department of Radiology, Cleveland, OH (United States); Vidimos, Allison [Cleveland Clinic Foundation, Department of Dermatology, Cleveland, OH (United States); DiFiore, John [Cleveland Clinic Foundation, Department of Pediatric Surgery, Cleveland, OH (United States)

2005-12-01

Plexiform neurofibroma is a pathognomonic, often disabling feature of neurofibromatosis type I. Although the target-like appearance of deep plexiform neurofibroma on T2-weighted MRI has been well-described, a second superficial form of plexiform neurofibroma has differing imaging features. We report a 15-year-old boy who presented with multiple cutaneous lesions exhibiting clinical and imaging characteristics of a venolymphatic malformation. These lesions were histologically proved to represent superficial plexiform neurofibromas. We wish to emphasize the unique MR findings of superficial plexiform neurofibromas; these findings are different from the imaging characteristics of the deep form and can be confused with a low-flow vascular malformation. (orig.)

Air-water upward flow in prismatic channel of rectangular base

International Nuclear Information System (INIS)

Carvalho Tofani, P. de.

1984-01-01

Experiments had carried out to investigate the two-phase upward air-water flow structure, in a rectangular test section, by using independent measuring techniques, which comprise direct viewing and photography, electrical probes and gamma-ray attenuation. Flow pattern maps and correlations for flow pattern transitions, void fraction profiles, liquid film thickness and superficial average void fraction are proposed and compared to available data. (Author) [pt

Improved superficial brain hemorrhage visualization in susceptibility weighted images by constrained minimum intensity projection

Science.gov (United States)

Castro, Marcelo A.; Pham, Dzung L.; Butman, John

2016-03-01

Minimum intensity projection is a technique commonly used to display magnetic resonance susceptibility weighted images, allowing the observer to better visualize hemorrhages and vasculature. The technique displays the minimum intensity in a given projection within a thick slab, allowing different connectivity patterns to be easily revealed. Unfortunately, the low signal intensity of the skull within the thick slab can mask superficial tissues near the skull base and other regions. Because superficial microhemorrhages are a common feature of traumatic brain injury, this effect limits the ability to proper diagnose and follow up patients. In order to overcome this limitation, we developed a method to allow minimum intensity projection to properly display superficial tissues adjacent to the skull. Our approach is based on two brain masks, the largest of which includes extracerebral voxels. The analysis of the rind within both masks containing the actual brain boundary allows reclassification of those voxels initially missed in the smaller mask. Morphological operations are applied to guarantee accuracy and topological correctness, and the mean intensity within the mask is assigned to all outer voxels. This prevents bone from dominating superficial regions in the projection, enabling superior visualization of cortical hemorrhages and vessels.

Character of GPR wave in air and processed method

International Nuclear Information System (INIS)

Shi Jianping; Zhang Zhiyong; Deng Juzhi

2009-01-01

The wave reflected by objects in the air is unavoidable because electromagnetic wave of GPR was send to all directions. There are three air reflection types: directly arrived wave, system ring and reflection wave. The directly arrived waves don't disturb the recognition of the reflections from earth because they affect the first short time of GPR trace record. But system ring and reflection from air are the mainly part of disturbs. The time and distance curve of reflection from air can be classified into two types: hyperbola type and line type. The reflection from air and from earth can be recognized by calculating the velocity of electromagnetic wave. Line type reflection can be filtered by background remove and 2-D filter; by comparing the migrated profiles with velocity in air and ground, the interpretation will become more exact. (authors)

Effect of warm air supplied facially on occupants' comfort

DEFF Research Database (Denmark)

Kaczmarczyk, J.; Melikov, Arsen Krikor; Sliva,, D.

2010-01-01

was supplied with a constant velocity of 0.4 m/s by means of personalized ventilation towards the face of the subjects. The airflow at 21 °C decreased the subjects' thermal sensation and increased draught discomfort, but improved slightly the perceived air quality. Heating of the supplied air by 6 K...... (temperature increase by 4 K at the target area) above the room air temperature decreased the draught discomfort, improved subjects' thermal comfort and only slightly decreased the perceived air quality. Elevated velocity and temperature of the localized airflow caused an increase of nose dryness intensity...... and number of eye irritation reports. Results suggest that increasing the temperature of the air locally supplied to the breathing zone by only a few degrees above the room air temperature will improve occupants' thermal comfort and will diminish draught discomfort. This strategy will extend...

Diagnostic and therapeutic challenges in superficial CNS siderosis

DEFF Research Database (Denmark)

Kondziella, Daniel; Lindelof, M.; Haziri, Donika

2015-01-01

the challenges related to the diagnosis and treatment of superficial siderosis. RESULTS: A potential bleeding aetiology was identified in all patients, but removal of the offending bleeding source was achieved only in three (33%). Symptom progression was halted in just one patient (11%), which suggests...... neurotoxicity due to accumulating iron toxicity. FUNDING: not relevant. TRIAL REGISTRATION: not relevant....

Measuring Outdoor Air Intake Rates into Existing Building

Energy Technology Data Exchange (ETDEWEB)

Fisk, William; Sullivan, Douglas; Cohen, Sebastian; Han, Hwataik

2009-04-16

Practical and accurate technologies are needed for continuously measuring and controlling outdoor air (OA) intake rates in commercial building heating, ventilating, and air conditioning (HVAC) systems. This project evaluated two new measurement approaches. Laboratory experiments determined that OA flow rates were measurable with errors generally less than 10 percent using electronic air velocity probes installed between OA intake louver blades or at the outlet face of louvers. High accuracy was maintained with OA flow rates as low as 15 percent of the maximum for the louvers. Thus, with this measurement approach HVAC systems do not need separate OA intakes for minimum OA supply. System calibration parameters are required for each unique combination of louver type and velocity sensor location but calibrations are not necessary for each system installation. The research also determined that the accuracy of measuring OA flow rates with velocity probes located in the duct downstream of the intake louver was not improved by installing honeycomb airflow straighteners upstream of the probes. Errors varied with type of upstream louver, were as high as 100 percent, and were often greater than 25 percent. In conclusion, use of electronic air velocity probes between the blades of OA intake louvers or at the outlet face of louvers is a highly promising means of accurately measuring rates of OA flow into HVAC systems. The use of electronic velocity probes downstream of airflow straighteners is less promising, at least with the relatively small OA HVAC inlet systems employed in this research.

Gamma Activation Analysis in the Havana Bay superficial sediments

International Nuclear Information System (INIS)

Lopez, N.; Gelen, A.; Diaz Riso, O.; Manso, M.V.; Simon, M.J.; Maslov, A.G.; Gustova, M.V.; Beltran, J.; Soto, J.

2003-01-01

A preliminary study of 26 elements of Havana Bay superficial sediments were made using Gamma Activation Analysis. Samples from five zones of Havana Bay were analyzed. The results show a close interrelation between the concentration levels of the studied elements and the contaminant sources

Effect of surface treatments on the spreading velocity of simplified adhesive systems Efeito de tratamentos de superfície na velocidade de escoamento de sistemas adesivos simplificados

Directory of Open Access Journals (Sweden)

Flávia B. Pazinatto

2006-12-01

Full Text Available OBJECTIVES: To determine the roughness of glass surfaces submitted to different treatments and to correlate it with the spreading velocity of two adhesive systems. MATERIALS AND METHODS: Glass slides were used as substrates to evaluate the spreading velocity of Single Bond and Prime & Bond NT adhesive systems. Six different surface treatments were compared: 1 no treatment; 2 silanization (SL; 3 sandblasting (SB; 4 SB + SL; 5 10% hydrofluoric acid treatment (HF; 6 HF + SL. Before and after treatments, surface roughness was measured by a profilometer (Ra, µm. Drop volumes (10 µl of the adhesive systems were deposited onto substrates with a micropipette to observe materials spreading during 30s. Data were expressed in mm/s as spreading velocity. Statistical significances among groups were analyzed using one-way and two-way-ANOVA designs and the SNK test. RESULTS: Significant differences in spreading velocity were found between materials (p OBJETIVO: Determinar a rugosidade de superficies submetidas a diferentes tratamentos e correlacionar rugosidade com velocidade de escoamento de sistemas adesivos MATERIAL AND MÉTODOS: Lâminas de vidro foram utilizadas como substrato para avaliar a velocidade de escoamento dos sistemas adesivos Single Bond and Prime & Bond NT. Seis diferentes tratamentos de superfície foram comparados: 1- sem tratamento; 2 - silanização (SL; 3 - jateamento (J; 4 - J + SL; 5 - condicionamento com ácido fluorídrico a 10% (HF; 6 - HF + SL. Antes e após os tratamentos, foi mensurada a rugosidade das superficies (Ra, µm. Gotas de 10 µl de adesivo foram despositadas sobre as superficies e as velocidades de escoamento foram observadas durante 30 seg. Dados de velocidade de escoamento foram expressos em mm/s. Significâncias estatísticas entre grupos foram analisadas pelos testes ANOVA (um e dois critérios e SNK. RESULTADOS: Houve diferenças significantes na velocidade de escoamento entre materiais (p < 0.001 e entre

Exhalation velocity of radon-222 of Dutch building materials and the influence of paint systems

International Nuclear Information System (INIS)

Dijk, W. van; Jong, P. de

1989-02-01

In order to achieve a better insight concerning the source terms of radon in the Dutch dwelling in the framework of the RENA-programme an investigation has been performed into the exhalation velocity of radon-222 from building materials. From this investigation it turned out that the ventilation factor does not have any influence upon the exhalation velocity, neither an influence of alteration of air pressure could be demonstrated. The influence of air humidity upon the exhalation velocity showed a twofold picture; for gypsum a linear increase of the exhalation velocity with vapour pressure was found, while for concrete a linear decrease with vapour pressure was observed. Further it has been investigated in how far paint systems diminish the exhalation velocity of the Rn-222 from gypsum and concrete. Acryl paints, mostly used in the Dutch dwelling, did not show a decrease of the exhalation velocity and structure paints did even cause an increase of the exhalation velocity. Other types of paint based on chlorous rubber, epoxy resins and poly-urethane, in contrast, showed a clear reduction. From these those based on poly-urethane showed the largest reduction (60-75%) at a double sided treatment of the wall. With the help of a mathematical modelling of the exhalation estimations have been made of the exhalation velocity of Rn-222 at single sided treatment of a wall and for the exhalation velocity of Rn-220. For the fore mentioned poly-urethane-paints this yelds, at an estimate, a reduction of respectively 90-95% and 100%. (author). 40 refs.; 15 figs.; 8 tabs

Micrometeorological studies for the characterization of the atmospheric superficial layer in the Valley of Mexico; Estudios micrometeorologicos para la caracterizacion de la capa atmosferica superficial en el Valle de Mexico

Energy Technology Data Exchange (ETDEWEB)

Saldana Flores, Ricardo; Salcido Gonzalez, Victor A.; Borja Diaz, Marco Antonio R.; Morales Reyes, Maria Flor [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1995-12-31

This work establishes the principal aspects related to two micrometeorological campaigns carried out in the Valley of Mexico, the first one from May 19 to 27, 1992 in the vicinity of the Valle de Mexico thermoelectric central and the second from September 13 to 21, 1993 in a site nearby the recreational lake of the Texcoco Plan. The first campaign of measurements encompassed the monitoring at ground level (at a height of 10 meters) of the following parameters: -wind orthogonal components; -temperature; -relative humidity; -Global radiation; - Net radiation; -Atmospheric pressure. Also, simultaneously five daily radio soundings were performed through a captive balloon and free soundings, up to an approximate height of 2500 meters. During the second campaign the same measurements as in the first campaign were carried out, except the radio soundings with the captive balloon, incorporating a turbulence ultrasonic sensor with which, among other parameters, were obtained: -Mean velocities of the wind orthogonal components; -Mean temperature; -Covariance of the wind component z and temperature; -Friction velocity; -Monin-Obukov length; -Vertical heat flow; -Wind mean velocity; -Wind mean direction. [Espanol] En el presente trabajo se anotan los principales aspectos relativos a dos campanas micrometeorologicas realizadas en el Valle de Mexico, la primera del 19 al 27 de mayo de 1992 en las inmediaciones de la central termoelectrica Valle de Mexico y la segunda del 13 al 21 de septiembre de 1993, en un sitio cercano al lago recreativo del Plan Texcoco. La primera campana de mediciones abarco el monitoreo en superficie (a 10 m de altura) de los siguientes parametros: - Componentes ortogonales del viento. - Temperatura. - Humedad relativa. - Radiacion global. - Radiacion neta. - Presion atmosferica. Asimismo, se llevaron a cabo simultaneamente cinco radiosondeos diarios a traves de un globo cautivo y de sondas libres, hasta una altura aproximada de 2500 metros. Durante la

Micrometeorological studies for the characterization of the atmospheric superficial layer in the Valley of Mexico; Estudios micrometeorologicos para la caracterizacion de la capa atmosferica superficial en el Valle de Mexico

Energy Technology Data Exchange (ETDEWEB)

Saldana Flores, Ricardo; Salcido Gonzalez, Victor A; Borja Diaz, Marco Antonio R.; Morales Reyes, Maria Flor [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1996-12-31

This work establishes the principal aspects related to two micrometeorological campaigns carried out in the Valley of Mexico, the first one from May 19 to 27, 1992 in the vicinity of the Valle de Mexico thermoelectric central and the second from September 13 to 21, 1993 in a site nearby the recreational lake of the Texcoco Plan. The first campaign of measurements encompassed the monitoring at ground level (at a height of 10 meters) of the following parameters: -wind orthogonal components; -temperature; -relative humidity; -Global radiation; - Net radiation; -Atmospheric pressure. Also, simultaneously five daily radio soundings were performed through a captive balloon and free soundings, up to an approximate height of 2500 meters. During the second campaign the same measurements as in the first campaign were carried out, except the radio soundings with the captive balloon, incorporating a turbulence ultrasonic sensor with which, among other parameters, were obtained: -Mean velocities of the wind orthogonal components; -Mean temperature; -Covariance of the wind component z and temperature; -Friction velocity; -Monin-Obukov length; -Vertical heat flow; -Wind mean velocity; -Wind mean direction. [Espanol] En el presente trabajo se anotan los principales aspectos relativos a dos campanas micrometeorologicas realizadas en el Valle de Mexico, la primera del 19 al 27 de mayo de 1992 en las inmediaciones de la central termoelectrica Valle de Mexico y la segunda del 13 al 21 de septiembre de 1993, en un sitio cercano al lago recreativo del Plan Texcoco. La primera campana de mediciones abarco el monitoreo en superficie (a 10 m de altura) de los siguientes parametros: - Componentes ortogonales del viento. - Temperatura. - Humedad relativa. - Radiacion global. - Radiacion neta. - Presion atmosferica. Asimismo, se llevaron a cabo simultaneamente cinco radiosondeos diarios a traves de un globo cautivo y de sondas libres, hasta una altura aproximada de 2500 metros. Durante la

Effect of aggregate size and superficial horizon differentiation on the friability index of soils cultivated with sugar cane: a multivariate approach

Directory of Open Access Journals (Sweden)

Edgar Alvaro Avila P.

2015-04-01

Full Text Available Soil friability is a physical property that provides valuable information for minimizing energy consumption during soil tillage and for preparing the edaphic medium for plant development. Its quantitative determination is generally carried out with aggregates obtained from soil blocks taken at fixed depths of profiles without considering the superficial horizons of the soil. The objective of the this study was to determine the effect of aggregate size and superficial horizon differentiation on the friability index (FI of some soils cultivated with sugar cane in the Geographic Valley of the Cauca River (Colombia, using univariate (CVu and multivariate (CVm coefficients of variation. The FI was evaluated using a compression test with four aggregate-size ranges taken from the Ap and A1 superficial horizons of 182 sampling sites located on 18 sugar cane farms. Of the five types of studied soils (Inceptisols, Mollisols, Vertisols, Alfisols and Ultisols, 7,280 aggregates were collected that were air dried and subsequently dried in a low-temperature oven before determining the tensile strength (TS, which was in turn used to calculate the FI using the coefficient of variation method. This study found that the FI varied with the aggregate size and the soil depth (first two horizons. Only three of the four size ranges initially selected were relevant. The CVm proved to be very useful for the selection of a more relevant value from the confidence interval of the TS from the CVu method for friability and established that the lower limit value (FIi of the TS CVu was the FI value that was closest to the multivariate measurement.

In vivo high-resolution 3D photoacoustic imaging of superficial vascular anatomy

International Nuclear Information System (INIS)

Zhang, E Z; Laufer, J G; Beard, P C; Pedley, R B

2009-01-01

The application of a photoacoustic imaging instrument based upon a Fabry-Perot polymer film ultrasound sensor to imaging the superficial vasculature is described. This approach provides a backward mode-sensing configuration that has the potential to overcome the limitations of current piezoelectric based detection systems used in superficial photoacoustic imaging. The system has been evaluated by obtaining non-invasive images of the vasculature in human and mouse skin as well as mouse models of human colorectal tumours. These studies showed that the system can provide high-resolution 3D images of vascular structures to depths of up to 5 mm. It is considered that this type of instrument may find a role in the clinical assessment of conditions characterized by changes in the vasculature such as skin tumours and superficial soft tissue damage due to burns, wounds or ulceration. It may also find application in the characterization of small animal cancer models where it is important to follow the tumour vasculature over time in order to study its development and/or response to therapy.

Photoluminescence of a superficial Si nanolayer and an example of its use

International Nuclear Information System (INIS)

Ley, M.; Svrcek, V.; Kuznicki, Z.T.

2003-01-01

A characteristic photoluminescence of a superficial Si nanolayer realized by ion implantation has been observed. This effect, being totally independent of those shown recently for a nanoscale Si-layered system, is similar to that produced by Si nanocrystals (Si nc). To visualize the nature and give evidence of this effect, we fabricated samples in two different ways: (i) by incorporation of Si nc into thin SiO 2 films deposited on Si wafer by the spin-on-glass method and (ii) by a nanoscale superficial crystalline-Si modification using medium-energy ion implantation and thermal treatment. In both cases the UV-to-red light conversion has been observed to be independent of wafer post-implantation damage. To show the UV-to-red conversion contribution, we use the ion modified superficial Si layer with its well-defined potential barrier, the so-called carrier collection limit. Such a modified Si structure gives us a method of deconvoluting several optoelectronic features observed experimentally on modified Si. The practical realization is compatible with well-established Si technology

In vivo high-resolution 3D photoacoustic imaging of superficial vascular anatomy

Energy Technology Data Exchange (ETDEWEB)

Zhang, E Z; Laufer, J G; Beard, P C [Department of Medical Physics and Bioengineering, University College London, Gower Street, London, WC1E 6BT (United Kingdom); Pedley, R B [UCL Cancer Institute, Paul O' Gorman Building, University College London, 72 Huntley St, London WC1E 6BT (United Kingdom)

2009-02-21

The application of a photoacoustic imaging instrument based upon a Fabry-Perot polymer film ultrasound sensor to imaging the superficial vasculature is described. This approach provides a backward mode-sensing configuration that has the potential to overcome the limitations of current piezoelectric based detection systems used in superficial photoacoustic imaging. The system has been evaluated by obtaining non-invasive images of the vasculature in human and mouse skin as well as mouse models of human colorectal tumours. These studies showed that the system can provide high-resolution 3D images of vascular structures to depths of up to 5 mm. It is considered that this type of instrument may find a role in the clinical assessment of conditions characterized by changes in the vasculature such as skin tumours and superficial soft tissue damage due to burns, wounds or ulceration. It may also find application in the characterization of small animal cancer models where it is important to follow the tumour vasculature over time in order to study its development and/or response to therapy.

Air flow optimization for energy efficient blower of biosafety cabinet class II A2

Science.gov (United States)

Ibrahim, M. D.; Mohtar, M. Z.; Alias, A. A.; Wong, L. K.; Yunos, Y. S.; Rahman, M. R. A.; Zulkharnain, A.; Tan, C. S.; Thayan, R.

2017-04-01

An energy efficient Biosafety Cabinet (BSC) has become a big challenge for manufacturers to develop BSC with the highest level of protection. The objective of research is to increase air flow velocity discharge from centrifugal blower. An aerodynamic duct shape inspired by the shape of Peregrine Falcon’s wing during diving flight is added to the end of the centrifugal blower. Investigation of air movement is determined by computational fluid dynamics (CFD) simulation. The results showed that air velocity can be increased by double compared to typical manufactured BSC and no air recirculation. As conclusion, a novel design of aerodynamic duct shape successfully developed and proved that air velocity can be increase naturally with same impeller speed. It can contribute in increasing energy efficiency of the centrifugal blower. It is vital to BSC manufacturer and can be apply to Heating, Air Ventilation and Air Conditioning (HVAC) industries.

Volumetric and superficial characterization of carbon activated

International Nuclear Information System (INIS)

Carrera G, L.M.; Garcia S, I.; Jimenez B, J.; Solache R, M.; Lopez M, B.; Bulbulian G, S.; Olguin G, M.T.

2000-01-01

The activated carbon is the resultant material of the calcination process of natural carbonated materials as coconut shells or olive little bones. It is an excellent adsorbent of diluted substances, so much in colloidal form, as in particles form. Those substances are attracted and retained by the carbon surface. In this work is make the volumetric and superficial characterization of activated carbon treated thermically (300 Centigrade) in function of the grain size average. (Author)

Neurothekeoma palpebrae in association with multiple superficial angiomyxomas: Tegumental Angiomyxoma- Neurothekeoma syndrome (TAN syndrome

Directory of Open Access Journals (Sweden)

Tan Aik Kah

2011-09-01

Full Text Available We report a case of 10-year-old Indian girl with history of multiple superficial angiomyxoma, presented with three months history of painless right upper lid swelling. There were no visual dysfunctions. Previously, the patient had multiple superficial angiomyxoma (left pinna, left upper cheek, left upper limb, chest, right axilla, hard palate and epidermal cyst (chin. The histopathological specimens were negative to S-100 protein antibody. Systemic review and family history was unremarkable. Excision biopsy and upper lid reconstruction were performed. Intraoperatively the tumor was multilobulated, firm, well encapsulated and did not invade the underlying tarsal plate. Histopathological features of the upperlid tumor were consistent with nerves sheath myxoma (neurothekeoma. To the best of the authors’ knowledge, this is the first reported case of neurothekeoma in association with multiple superficial angiomyxoma.

Neurothekeoma palpebrae in association with multiple superficial angiomyxomas: Tegumental Angiomyxoma-Neurothekeoma syndrome (TAN syndrome).

Science.gov (United States)

Kah, Tan Aik; Yong, Ku Chui; Annuar, Faridah Hanom

2011-07-01

We report a case of 10-year-old Indian girl with history of multiple superficial angiomyxoma, presented with three months history of painless right upper lid swelling. There were no visual dysfunctions. Previously, the patient had multiple superficial angiomyxoma (left pinna, left upper cheek, left upper limb, chest, right axilla, hard palate) and epidermal cyst (chin). The histopathological specimens were negative to S-100 protein antibody. Systemic review and family history was unremarkable. Excision biopsy and upper lid reconstruction were performed. Intraoperatively the tumor was multilobulated, firm, well encapsulated and did not invade the underlying tarsal plate. Histopathological features of the upperlid tumor were consistent with nerves sheath myxoma (neurothekeoma). To the best of the authors' knowledge, this is the first reported case of neurothekeoma in association with multiple superficial angiomyxoma.

Corte y sellado reversible de dientes para obtener superficies internas de esmalte incólumes

Directory of Open Access Journals (Sweden)

Ana Milena Santiago-Medina

2015-07-01

Full Text Available Las superficies internas de los dientes, que se obtienen por cortes con discos, están generalmente desorganizadas por los giros, la velocidad y la rugosidad del disco. El calor altera la superficie y el agua de la refrigeración la composición química porque disuelve los componentes. En estudios de difusión, el perfil se borra por el corte, lo que anula resultados. Objetivo: desarrollar un método de sellado de superficies internas, ya cortadas antes de los ensayos de difusión, sin dejar trazas químicas o partículas. Materiales y metedos: se probó in vitro la habilidad de cuatro materiales de sellado con 40 especimenes, provenientes de 20 coronas de terceros molares, cortadas sagitalmente. Los especímenes se distribuyeron aleatoriamente en cuatro grupos (n = 10: G1: Teflón (Topex®, G2: Tela de caucho (Dental DAM®, G3: película de cloruro de polivinilo (Vinilpel® y G4: Cinta aislante (Tesa®. Se usó una solución de azul de metileno (AM al 2% por 6 días como indicadora de filtración. Por observación visual de cada muestra, se le asignó un valor (sí o no dependiendo de la presencia o ausencia de cualquier punto MB sobre la superficie de sellado. Los resultados fueron analizados siguiendo un modelo estadístico de respuesta binomial. Resultados: Siguiendo los procedimientos descritos, el teflón es el único material que previene la filtración de AM en la superficie interna expuesta por el corte. Conclusión: Se propone un protocolo de sellado reversible de las superficies internas con teflón, previo al corte de los dientes, para no alterar los resultados experimentales.

Is superficial burn caused by ultraviolet radiation (sunburn) comparable to superficial burn caused by heat--a histomorphological comparison by in vivo Reflectance-Mode-Confocal Microscopy.

Science.gov (United States)

Altintas, M A; Altintas, A A; Guggenheim, M; Busch, K H; Niederbichler, A D; Aust, M C; Vogt, P M

2009-12-01

Regardless of the underlying cause, both sunburn and superficial thermal injuries are classified as first-degree burns, since data on morphological differences are scarce. Reflectance-Mode-Confocal Microscopy (RMCM) enables high-resolution non-invasive investigation of the human skin. We studied in vivo histomorphological alterations in both sunburn and superficial thermal injuries using RMCM. Ten patients (6 female, 4 male; aged 28.4 +/- 10.6 years) with first-degree thermal-contact Injuries (TI group), and 9 sunburned patients (SB group; 7 female, 2 male; aged 30.2 +/- 16.4 years), to a maximum extent of 10% of the body surface were evaluated 24 h after burn injury using RMCM. The following parameters were obtained using RMCM: stratum corneum thickness, epidermal thickness, basal layer thickness, granular cell size. Compared to the controls (12.8 +/- 2.5 microm), stratum corneum thickness decreased significantly to 10.6 +/- 2.1 microm in the TI group, whereas it increased significantly to 16.4 +/- 3.1 microm in the SB group. The epidermal thickness did not differ significantly in the TI group (47.9 +/- 2.3 microm) and SB group (49.1 +/- 3.5 microm); however, both increased significantly compared to their respective controls (41.8 +/- 1.4 microm). The basal layer thickness increased more in the SB group compared to the TI group (17.9 +/- 1.4 microm vs. 15.6 +/- 1.1 microm). Both differed also significantly compared to their controls (13.8 +/- 0.9 microm). The granular cell size increased significantly in both groups compared to the controls (731 +/- 42 microm); however, a significantly higher increase was observed in the TI group (852 +/- 58 microm) compared to the SB group (784 +/- 61 microm). Ultraviolet radiation seems to influence predominantly deeper epidermal layers, whereas heat-induced burns affect more superficial epidermal layers. The term 'First-degree burn' should not be used synonymously for sunburn and superficial thermal burn injuries. Conflicts of

Ultrathin endoscopy versus high-resolution endoscopy for diagnosing superficial gastric neoplasia.

Science.gov (United States)

Toyoizumi, Hirobumi; Kaise, Mitsuru; Arakawa, Hiroshi; Yonezawa, Jin; Yoshida, Yukinaga; Kato, Masayuki; Yoshimura, Noboru; Goda, Ken-ichi; Tajiri, Hisao

2009-08-01

Ultrathin endoscopy (UTE) is an acceptable and cost-effective alternative to EGD with the patient under sedation, although the diagnostic accuracy of UTE is not well established. To compare the diagnostic accuracy of UTE and high-resolution endoscopy (HRE) for superficial gastric neoplasia. Prospective comparative study. Academic center. Patients with or without superficial gastric neoplasia underwent peroral UTE and HRE, back-to-back in a random order while under standard sedation. The procedures were performed by 2 endoscopists who were blinded to the clinical information. The rate of missed lesions and misdiagnosis, sensitivity, and specificity for the diagnosis of gastric neoplasia when using pathology as the reference standard. In total, 126 lesions (41 superficial gastric neoplasias, 85 nonneoplastic lesions) were recorded in 57 enrolled patients. For the diagnosis of gastric neoplasia, the sensitivity of UTE (58.5%) was significantly (P = .021) lower than that of HRE (78%), and the specificity of UTE (91.8%) was significantly (P = .014) lower than that of HRE (100%). The rate of missed lesions and misdiagnosis of gastric neoplasias when using UTE (41.5%) was significantly (P > .001) higher than that of HRE (22.0%). The corresponding rate of neoplasias at the proximal portion (fornix and corpus) when using UTE (29%) was significantly (P = .002) higher than that of HRE (7.2%), although the rates of neoplasias at the distal portion (angulus and antrum) were comparable for UTE and HRE. Small sample numbers in an enriched population. The diagnostic accuracy of UTE is significantly lower than that of HRE for superficial gastric neoplasia, and this difference is particularly striking for neoplasias in the proximal stomach. For UTE to be used as an alternative modality, improvements in optical quality and the incorporation of additional procedures, including close-range observations and chromoendoscopy, are required to enhance visualization.

Superficial siderosis of the central nervous system | Govind | SA ...

African Journals Online (AJOL)

progression of clinical deterioration but halting the chronic subarachoid haemorrhage will reduce the iron load in the CSF and hence the cytotoxic risk. We present a case of superficial siderosis presenting with hearing loss and cerebellar signs highlighting the imaging findings. South African Journal of Radiology Vol.

Gross anatomy of superficial fascia and future localised fat deposit areas of the abdomen in foetus

Directory of Open Access Journals (Sweden)

Pramod Kumar

2013-01-01

Full Text Available Background: The development and popularity of body contouring procedures such as liposuction and abdominoplasty has renewed interest in the anatomy of the superficial fascia and subcutaneous fat deposits of the abdomen. The study of anatomy of fascia and fetal adipose tissue was proposed as it may be of value in understanding the possible programing of prevention of obesity. Objectives: The present study was undertaken to understand the gross anatomy of superficial fascia of abdomen and to study the gross anatomy of future localized fat deposits (LFDs area of abdomen in fetus. Materials and Methods: Four fetus (two male & two female of four month of intrauterine life were dissected. Attachments & layers of superficial fascia and future subcutaneous fat deposit area of upper and lower abdomen were noted. Results: Superficial fascia of the abdomen was multi layered in mid line and number of layers reduced laterally as in adult. The future abdominal LFD (localized fat deposits area in fetus shows brownish-white blubbary tissue without well-defined adult fat lobules. Conclusion: The attachment and gross anatomy of superficial fascia of the fetus was similar to that in adults. The future LFD areas showed brownish white blubbary tissue with ill-defined fat lobules.

Measurement of two-dimensional bubble velocity by Using tri-fiber-optical Probe

International Nuclear Information System (INIS)

Yang Ruichang; Zheng Rongchuan; Zhou Fanling; Liu Ruolei

2009-01-01

In this study, an advanced measuring system with a tri-single-fiber-optical-probe has been developed to measure two-dimensional vapor/gas bubble velocity. The use of beam splitting devices instead of beam splitting lens simplifies the optical system, so the system becomes more compact and economic, and more easy to adjust. Corresponding to using triple-optical probe for measuring two-dimensional bubble velocity, a data processing method has been developed, including processing of bubble signals, cancelling of unrelated signals, determining of bubble velocity with cross correlation technique and so on. Using the developed two-dimensional bubble velocity measuring method, the rising velocity of air bubbles in gravitational field was measured. The measured bubble velocities were compared with the empirical correlation available. Deviation was in the range of ±30%. The bubble diameter obtained by data processing is in good accordance with that observed with a synchro-scope and a camera. This shows that the method developed here is reliable.

Effects of H2O, CO2, and N2 Air Contaminants on Critical Airside Strain Rates for Extinction of Hydrogen-Air Counterflow Diffusion Flames

Science.gov (United States)

Pellett, G. L.; Wilson, L. G.; Northam, G. B.; Guerra, Rosemary

1989-01-01

Coaxial tubular opposed jet burners (OJB) were used to form dish shaped counterflow diffusion flames (CFDF), centered by opposing laminar jets of H2, N2 and both clean and contaminated air (O2/N2 mixtures) in an argon bath at 1 atm. Jet velocities for flame extinction and restoration limits are shown versus wide ranges of contaminant and O2 concentrations in the air jet, and also input H2 concentration. Blowoff, a sudden breaking of CFDF to a stable ring shape, occurs in highly stretched stagnation flows and is generally believed to measure kinetically limited flame reactivity. Restore, a sudden restoration of central flame, is a relatively new phenomenon which exhibits a H2 dependent hysteresis from Blowoff. For 25 percent O2 air mixtures, mole for mole replacement of 25 percent N2 contaminant by steam increased U(air) or flame strength at Blowoff by about 5 percent. This result is consistent with laminar burning velocity results from analogous substitution of steam for N2 in a premixed stoichiometric H2-O2-N2 (or steam) flame, shown by Koroll and Mulpuru to promote a 10 percent increase in experimental and calculated laminar burning velocity, due to enhanced third body efficiency of water in: H + O2 + M yields HO2 + M. When the OJB results were compared with Liu and MacFarlane's experimental laminar burning velocity of premixed stoichiometric H2 + air + steam, a crossover occurred, i.e., steam enhanced OJB flame strength at extinction relative to laminar burning velocity.

CFD simulation research on residential indoor air quality.

Science.gov (United States)

Yang, Li; Ye, Miao; He, Bao-Jie

2014-02-15

Nowadays people are excessively depending on air conditioning to create a comfortable indoor environment, but it could cause some health problems in a long run. In this paper, wind velocity field, temperature field and air age field in a bedroom with wall-hanging air conditioning running in summer are analyzed by CFD numerical simulation technology. The results show that wall-hanging air conditioning system can undertake indoor heat load and conduct good indoor thermal comfort. In terms of wind velocity, air speed in activity area where people sit and stand is moderate, most of which cannot feel wind flow and meet the summer indoor wind comfort requirement. However, for air quality, there are local areas without ventilation and toxic gases not discharged in time. Therefore it is necessary to take effective measures to improve air quality. Compared with the traditional measurement method, CFD software has many advantages in simulating indoor environment, so it is hopeful for humans to create a more comfortable, healthy living environment by CFD in the future. Copyright © 2013 Elsevier B.V. All rights reserved.

Numerical study of a PCM-air heat exchanger's thermal performance

Science.gov (United States)

Herbinger, F.; Bhouri, M.; Groulx, D.

2016-09-01

In this paper, the use of PCMs in HVAC applications is investigated by studying numerically the thermal performance of a PCM-air heat exchanger. The PCM used in this study is dodecanoic acid. A symmetric 3D model, incorporating conductive and convective heat transfer (air only) as well as laminar flow, was created in COMSOL Multiphysics 5.0. Simulations examined the dependence of the heat transfer rate on the temperature and velocity of the incoming air as well as the size of the channels in the heat exchanger. Results indicated that small channels size lead to a higher heat transfer rates. A similar trend was also obtained for high incoming air temperature, whereas the heat transfer rate was less sensitive to the incoming air velocity.

Transdermal drug delivery: feasibility for treatment of superficial bone stress fractures.

Science.gov (United States)

Aghazadeh-Habashi, Ali; Yang, Yang; Tang, Kathy; Lőbenberg, Raimar; Doschak, Michael R

2015-12-01

Transdermal drug delivery offers the promise of effective drug therapy at selective sites of pathology whilst reducing systemic exposure to the pharmaceutical agents in off-target organs and tissues. However, that strategy is often limited to cells comprising superficial tissues of the body (rarely to deeper bony structures) and mostly indicated with small hydrophobic pharmacological agents, such as steroid hormones and anti-inflammatory gels to skin, muscle, and joints. Nonetheless, advances in transdermal liposomal formulation have rendered the ability to readily incorporate pharmacologically active hydrophilic drug molecules and small peptide biologics into transdermal dosage forms to impart the effective delivery of those bioactive agents across the skin barrier to underlying superficial tissue structures including bone, often enhanced by some form of electrical, chemical, and mechanical facilitation. In the following review, we evaluate transdermal drug delivery systems, with a particular focus on delivering therapeutic agents to treat superficial bone pain, notably stress fractures. We further introduce and discuss several small peptide hormones active in bone (such as calcitonins and parathyroid hormone) that have shown potential for transdermal delivery, often under the added augmentation of transdermal drug delivery systems that employ lipo/hydrophilicity, electric charge, and/or microprojection facilitation across the skin barrier.

Reducing the negative vocal effects of superficial laryngeal dehydration with humidification.

Science.gov (United States)

Levendoski, Elizabeth Erickson; Sundarrajan, Anusha; Sivasankar, M Preeti

2014-07-01

Environmental humidification is a simple, cost-effective method believed to reduce superficial laryngeal drying. This study sought to validate this belief by investigating whether humidification treatment would reduce the negative effects of superficial laryngeal dehydration on phonation threshold pressure (PTP). Phonation threshold pressure data analysis may be vulnerable to bias because of lack of investigator blinding. Consequently, this study investigated the extent of PTP analysis reliability between unblinded and blinded investigators. Healthy male and female adults were assigned to a vocal fatigue (n = 20) or control group (n = 20) based on their responses to a questionnaire. PTP was assessed after 2 hours of mouth breathing in low humidity (dehydration challenge), following a 5-minute break in ambient humidity, and after 2 hours of mouth breathing in high humidity (humidification). PTP significantly increased following the laryngeal dehydration challenge. After humidification, PTP returned toward baseline. These effects were observed in both subject groups. PTP measurements were highly correlated between the unblinded and blinded investigator. Humidification may be an effective approach to decrease the detrimental voice effects of superficial laryngeal dehydration. These data lay the foundation for future investigations aimed at preventing and treating the negative voice changes associated with chronic, surface laryngeal drying.

Study of the mechanisms involved in the laser superficial hardening process of metallic alloys

International Nuclear Information System (INIS)

Silva, Edmara Marques Rodrigues da

2001-01-01

The laser superficial hardening process of a ferrous alloy (gray cast iron) and of an aluminum-silicon alloy was investigated in this work. These metallic alloys are used in the automobile industry for manufacturing cylinders and pistons, respectively. By application of individual pulses and single tracks, the involved mechanisms during the processing were studied. Variables such as energy density, power density, temporal width, beam diameter on the sample surface, atmosphere of the processing region, overlapping and scanning velocity. The hardened surface was characterized by optical and scanning electronic microscopy, dispersive energy microanalysis, X-ray mapping, X-ray diffraction, and measurements of roughness and Vickers microhardness. Depending on the processing parameters, it is possible to obtain different microstructures. The affected area of gray cast iron, can be hardened by remelting or transformation hardening (total or partial) if the reached temperature is higher or not that of melting temperature. Laser treatment originated new structures such as retained austenite, martensite and, occasionally, eutectic of cellular dendritic structure. Aluminum-silicon alloy does not have phase transformation in solid state, it can be hardened only by remelting. The increase of hardness is a function of the precipitation hardening process, which makes the silicon particles smaller and more disperse in the matrix. Maximal values of microhardness (700-1000 HV) were reached with the laser treatment in gray cast iron samples. The initial microhardness is of 242 HV. For aluminum-silicon alloy, the laser remelting increases the initial microhardness of 128 HV to the range of 160-320 HV. The found results give a new perspective for using the CLA/IPEN's laser in the heat treatment area. Besides providing a higher absorptivity to the materials, compared with the CO 2 laser, and optical fiber access, the superficial hardening with Nd:YAG laser, depending on the level of

Mathematical Models for Room Air Distribution - Addendum

DEFF Research Database (Denmark)

Nielsen, Peter V.

1982-01-01

A number of different models on the air distribution in rooms are introduced. This includes the throw model, a model on penetration length of a cold wall jet and a model for maximum velocity in the dimensioning of an air distribution system in highly loaded rooms and shows that the amount of heat...... removed from the room at constant penetration length is proportional to the cube of the velocities in the occupied zone. It is also shown that a large number of diffusers increases the amount of heat which may be removed without affecting the thermal conditions. Control strategies for dual duct and single...... duct systems are given and the paper is concluded by mentioning a computer-based prediction method which gives the velocity and temperature distribution in the whole room....

Parametric simulation and experimental analysis of earth air heat exchanger with solar air heating duct

Directory of Open Access Journals (Sweden)

Sanjeev Jakhar

2016-06-01

Full Text Available Earth air heat exchanger (EAHE systems are insufficient to meet the thermal comfort requirements in winter conditions. The low heating potential of such systems can be improved by integrating the system with solar air heating duct (SAHD. The aim of this paper is to present a model to estimate the heating potential for EAHE system with and without SAHD. The model is generated using TRNSYS 17 simulation tool and validated against experimental investigation on an experimental set-up in Ajmer, India. The experiment was done during the winter season, where the system was evaluated for different inlet flow velocities, length and depth of buried pipe. From the experimentation, it was observed that the depth of 3.7 m is sufficient for pipe burial and the 34 m length of pipe is sufficient to get optimum EAHE outlet temperature. It is also observed that increase in flow velocity results in drop in EAHE outlet temperature, while room temperature is found to increase for higher velocities (5 m/s. The COP of the system also increased up to 6.304 when assisted with solar air heating duct. The results obtained from the experiment data are in good agreement with simulated results within the variation of up to 7.9%.

Velocity Distribution in the Flow from a Wall-Mounted Diffuser in Rooms with Displacement Ventilation

DEFF Research Database (Denmark)

Nielsen, Peter V.

The paper describes experiments with wall-mounted air terminal devices. The airflow from an air terminal device will influence the thermal comfort of the occupants and it is therefore important to develop an expression for this flow. The velocity at the floor is influenced by the flow rate...

Reaction velocity of sodium hydration in humid air and sodium carbonation in humid carbon dioxide atmosphere. Fundamental study on sodium carbonate process in FBR bulk sodium coolant disposal technology

International Nuclear Information System (INIS)

Tadokoro, Yutaka; Yoshida, Eiichi

1999-11-01

A sodium carbonate processing method, which changes sodium to sodium carbonate and/or sodium bicarbonate by humid carbon dioxide, has been examined and about to be applied to large test loops dismantling. However, that the basic data regarding the progress of the reaction is insufficient on the other hand, is a present condition. The present report therefore aims at presenting basic data regarding the reaction velocity of sodium hydration in humid air and sodium carbonation in humid carbon dioxide atmosphere, and observing the reaction progress, for the application to large test loops dismantling. The test result is summarized as follows. (1) Although the reaction velocity of sodium varied with sodium specimen sizes and velocity measurement methods, the reaction velocity of sodium hydration was in about 0.16 ∼ 0.34 mmh -1 (0.016 ∼ 0.033g cm -2 h -1 , 6.8x10 -4 ∼ 1.4x10 -3 mol cm -2 h -1 ) and that of sodium carbonation was in about 0.16 ∼ 0.27mmh -1 (0.016 ∼ 0.023g cm -2 h -1 , 6.8x10 -4 ∼ 1.1x10 -3 mol cm -2 h -1 ) (26 ∼ 31degC, RH 100%). (2) The reaction velocity of sodium in carbon dioxide atmosphere was greatly affected by vapor partial pressure (absolutely humidity). And the velocity was estimated in 0.08 ∼ 0.12mmh -1 (0.008 ∼ 0.012g cm -2 h -1 , 3.4x10 -4 ∼ 5.2x10 -4 mol cm -2 h -1 ) in the carbon dioxide atmosphere, whose temperature of 20degC and relative humidity of 80% are assumed real sodium carbonate process condition. (3) By the X-ray diffraction method, NaOH was found in humid air reaction product. Na 2 CO 3 , NaHCO 3 were found in carbon dioxide atmosphere reaction product. It was considered that Sodium changes to NaOH, and subsequently to NaHCO 3 through Na 2 CO 3 . (4) For the application to large test loops dismantling, it is considered possible to change sodium to a target amount of sodium carbonate (or sodium bicarbonate) by setting up gas supply quantity and also processing time appropriately according to the surface area

Optimizing of Make Up Air Performance for Commercial Kitchen Ventilation Improvement

Directory of Open Access Journals (Sweden)

Manshoor B.

2014-07-01

Full Text Available A commercial kitchen is a complicated environment where multiple components of a ventilation system including kitchen hood, exhaust fan, air supply, and make up air systems work together but not always in unison. For the commercial kitchen environment, make up air systems used to control the kitchen space from unwanted odor and thermal confort. Make air systems for commercial kitchen already established. However, an optimization is important to determine the most suitable make air systems and at the same time can improve the thermal comfort in the working space. In this study, a simulation work was conducted to investigate a suitable supply air velocity to optimize the make up air for kitchen ventilation system. In order to achieve the objectives, ANSYS FLUENT software (CFD was used to carry out the simulation and analysis. 3D kitchen space with 10m x 8m x 3m with air supply velocity was set to 0 m/s, 0.14 m/s, 0.28 m/s and 0.42 m/s. From the simulation work, the velocity of air flow tested which is 0.28 m/s is enough to control the heat and give an enough comfort to the working space for the size of kitchen simulated. Well implementation of the make up air in the kitchen hood can improve an air quality in the commercial kitchen and also keep the kitchen space comfortable to the workers.

Experimental and Numerical Investigation of Effect of Air Stability on Exhaled Air Dispersion

DEFF Research Database (Denmark)

Xu, Chunwen; Gong, Guangcai; Nielsen, Peter Vilhelm

2014-01-01

studies. As the thermal stratification under displacement ventilation blocks the vertical movement of exhaled air, the exhaled contaminant may be trapped between temperature stratifications. As the dispersion of contaminant is closely related to the health of human indoors, the temperature structure...... was used for experimental study, and a numerical person was built to simulate the manikin. The velocity, temperature and concentration of tracer gas in exhaled air are affected by air stability to different degrees. The similarity of this effect among these parameters can also be observed through numerical...

Tratamento do aneurisma aterosclerótico da artéria temporal superficial: relato de caso

Directory of Open Access Journals (Sweden)

Paula Dayana Matkovski

2015-09-01

Full Text Available ResumoAneurismas da artéria temporal superficial são incomuns segundo a literatura. A grande maioria é secundária a traumatismos ou cirurgia na região temporal, sendo que 95% dos casos evoluem para pseudoaneurismas. Entretanto, os aneurismas verdadeiros ou espontâneos são extremamente raros e representam 8% dos casos de aneurismas da artéria temporal superficial, sendo estes, geralmente, de origem aterosclerótica. Aneurismas temporais espontâneos podem coexistir com outras lesões vasculares, incluindo aneurismas intracranianos. Nosso relato trata de um paciente com aneurisma de artéria temporal superficial esquerda, de origem aterosclerótica, no qual foi realizada a excisão cirúrgica, sob anestesia geral.

Risk factors associated with acquiring superficial fungal infections in ...

African Journals Online (AJOL)

extensively documented. It is therefore imperative to identify the factors that predispose to the development of SFI so as to provide evidence-based and effective pre- ventive measures, thus reducing the prevalence and the attendant morbidity associated with superficial fungal in- fections and this was our aim in this present ...

Extinction of corrugated hydrogen/air flames

International Nuclear Information System (INIS)

Mizomoto, M.; Asaka, Y.; Ikai, S.; Law, C.K.

1982-01-01

Recent studies on flammability limits reveal the importance of flow nonuniformity, flame curvature, and molecular and thermal diffusivities in determining the extinguishability and the associated limits of premixed fuel/air flames. In particular, it is found that conditions which favor extinction of a lean flame may cause intensification of a rich flame. In the present study the authors have experimentally determined the extinction characteristics and limits of highly curved hydrogen/air flames as represented by the opening of bunsen flame tips. Results show that the tip opens at a constant fuel equivalence ratio of phi = 1.15, regardless of the velocity and uniformity of the upstream flow. This critical mixture concentration, while being rich, is still on the lean side of that corresponding to the maximum burning velocity (phi = 1.8), implying that for highly diffusive systems, the relevant reference concentration is that for maximum burning velocity instead of stoichiometry

Honey compared with silver sulphadiazine in the treatment of superficial partial-thickness burns.

Science.gov (United States)

Malik, Kamran Ishaque; Malik, M A Nasir; Aslam, Azhar

2010-10-01

Burn injury is associated with a high incidence of death and disability; yet, its management remains problematic and costly. We conducted this clinical study to evaluate the efficacy of honey in the treatment of superficial and partial-thickness burns covering less than 40% of body surface area and compared its results with those of silver sulphadiazine (SSD). In this randomised comparative clinical trial, carried out Burn Center of POF Hospital, Wah Cantt, Pakistan, from May 2007 to February 2008, 150 patients of all ages having similar types of superficial and partial-thickness burns at two sites on different parts of body were included. Each patient had one burn site treated with honey and one treated with topical SSD, randomly. The rate of re-epithelialization and healing of superficial and partial-thickness burns was significantly faster in the sites treated with honey than in the sites treated with SSD (13·47 ± 4·06 versus 15·62 ± 4·40 days, respectively: P honey healed completely in less than 21 days versus 24 days for the site treated with SSD. Six patients had positive culture for Pseudomonas aeroginsa in honey-treated site, whereas 27 patients had positive culture in SSD-treated site. The results clearly showed greater efficacy of honey over SSD cream for treating superficial and partial-thickness burns. 2010 The Authors. Journal Compilation © 2010 Blackwell Publishing Ltd and Medicalhelplines.com Inc.

Removal of dissolved organic carbon in pilot wetlands of subsuperficial and superficial flows

Directory of Open Access Journals (Sweden)

Ruth M. Agudelo C

2010-04-01

Full Text Available Objective: to compare removal of dissolved organic carbon (d o c obtained with pilot wetlands of subsuperficial flow (p h s s and superficial flow (p h s, with Phragmites australis as treatment alternatives for domestic residual waters of small communities and rural areas. Methodology: an exploratory and experimental study was carried out adding 100,12 mg/L of dissolved organic carbon to synthetic water contaminated with Chlorpyrifos in order to feed the wetlands. A total amount of 20 samples were done, 16 of them in four experiments and the other ones in the intervals with no use of pesticides. Samples were taken on days 1, 4, 8, and 11 in the six wetlands, three of them subsuperficial, and three of them superficial. The main variable answer was dissolved organic carbon, measured in the organic carbon analyzer. Results: a high efficiency in the removal of d o c was obtained with the two types of wetlands: 92,3% with subsuperficial flow and 95,6% with superficial flow. Such a high removal was due to the interaction between plants, gravel and microorganisms. Conclusion: although in both types of wetlands the removal was high and similar, it is recommended to use those of subsuperficial flow because in the superficial ones algae and gelatinous bio-films are developed, which becomes favorable to the development of important epidemiologic vectors in terms of public health.

Air-water mixing experiments for direct vessel injection of KNGR

International Nuclear Information System (INIS)

Hwang, Do Hyun

2000-02-01

Two air-water mixing experiments are conducted to understand the flow behavior in the downcomer for Direct Vessel Injection (DVI) of Korean Next Generation Reactor (KNGR). In the first experiment which is an air-water experiment in the rectangular channel with the gap size of 1cm, the width of water film is proportional to the water and air velocities and the inclined angle is proportional to the water velocity only, regardless of the water velocity injected in the rectangular channel. It is observed that the amount of entrained water is negligible. In the second experiment which is a full-scaled water jetting experiment without air flow, the width of water film is proportional to the flow rate injected from the pipe exit and the film thickness of water varies from 1.0mm to 5.0mm, and the maximum thickness does not exceed 5.0mm. The amount of water separated from the liquid film after striking of water jetting on the wall is measured. The amount of separation water is proportional to the flow rate, but the separation ratio in the full-scaled water jetting is not over 15%. A simplified physical model, which is designed to predict the trajectories of the width of water film, is validated through the comparison with experiment results. The 13 .deg. upward water droplet of the water injected from the pipe constitutes the outermost boundary at 1.7m below from pipe level, after the water impinges against the wall. In the model, the parameter, η which represents the relationship between the jetting velocity and the initial spreading velocity, is inversely proportional to the water velocity when it impinges against the wall. The error of the predictions by the model is decreased within 14% to the experimental data through use of exponential fitting of η for the jetting water velocity

Superficial femoral artery: current treatment options

International Nuclear Information System (INIS)

Tepe, Gunnar; Schmehl, Joerg; Heller, Stephan; Wiesinger, Benjamin; Claussen, Claus D.; Duda, Stephan H.

2006-01-01

Treatment of the superficial femoral artery (SFA) has been among the least effective of all endovascular procedures in terms of long-term patency. The relatively small vessel lumen, in conjunction with a high plaque burden, slow flow, and a high frequency of primary occlusions, contributes to a considerable rate of acute technical failures. Because of these technical limitations a much effort has been made during the past years. This manuscript should summarize the hopes and limitations of different approaches such as brachytherapy, cutting balloons, stents and stent grafts, drug-eluting stents, and drug-coated balloons. (orig.)

Flow Perturbation Mediates Neutrophil Recruitment and Potentiates Endothelial Injury via TLR2 in Mice: Implications for Superficial Erosion.

Science.gov (United States)

Franck, Grégory; Mawson, Thomas; Sausen, Grasiele; Salinas, Manuel; Masson, Gustavo Santos; Cole, Andrew; Beltrami-Moreira, Marina; Chatzizisis, Yiannis; Quillard, Thibault; Tesmenitsky, Yevgenia; Shvartz, Eugenia; Sukhova, Galina K; Swirski, Filip K; Nahrendorf, Matthias; Aikawa, Elena; Croce, Kevin J; Libby, Peter

2017-06-23

Superficial erosion currently causes up to a third of acute coronary syndromes; yet, we lack understanding of its mechanisms. Thrombi because of superficial intimal erosion characteristically complicate matrix-rich atheromata in regions of flow perturbation. This study tested in vivo the involvement of disturbed flow and of neutrophils, hyaluronan, and Toll-like receptor 2 ligation in superficial intimal injury, a process implicated in superficial erosion. In mouse carotid arteries with established intimal lesions tailored to resemble the substrate of human eroded plaques, acute flow perturbation promoted downstream endothelial cell activation, neutrophil accumulation, endothelial cell death and desquamation, and mural thrombosis. Neutrophil loss-of-function limited these findings. Toll-like receptor 2 agonism activated luminal endothelial cells, and deficiency of this innate immune receptor decreased intimal neutrophil adherence in regions of local flow disturbance, reducing endothelial cell injury and local thrombosis ( P <0.05). These results implicate flow disturbance, neutrophils, and Toll-like receptor 2 signaling as mechanisms that contribute to superficial erosion, a cause of acute coronary syndrome of likely growing importance in the statin era. © 2017 American Heart Association, Inc.

Radiación acústica por superficies planas: Aplicación a altavoces

OpenAIRE

Alba, Jesús; Ramis, Jaime; Espinosa, Víctor; Sánchez, Víctor

2003-01-01

En los sistemas de reproducción sonora es habitual la utilización de altavoces dinámicos. Sin embargo, en aplicaciones específicas, puede ser necesaria y/o conveniente la utilización de altavoces alternativos con superficies planas como diafragma, como los electrostáticos o los basados en la tecnología NXT© . Estos altavoces generan el campo acústico mediante la vibración de una superficie rectangular. Se puede suponer, en una primera aproximación, que todos los puntos sobre su su...

Impact of heat load location and strength on air flow pattern with a passive chilled beam system

Energy Technology Data Exchange (ETDEWEB)

Kosonen, Risto [Halton Oy, Niittyvillankuja 4, 01510 Vantaa (Finland); Saarinen, Pekka; Koskela, Hannu [Finnish Institute of Occupational Health, Lemminkaisenkatu 14-18 B, 20520 Turku (Finland); Hole, Alex [Arup, Rob Leslie-Carter, Level 10, 201 Kent Street, Sydney, NSW 2000 (Australia)

2010-01-15

A passive chilled beam is a source of natural convection, creating a flow of cold air directly into the occupied zone. Experiments were conducted in a mock-up of an office room to study the air velocities in the occupied spaces. In addition, velocity profiles are registered when underneath heat loads exist and the cool and warm air flows interact. Experimental laboratory study revealed that in the case of the underneath heat gains, even no upward plume was generated and the dummy only acted as a flow obstacle, having a significant effect on the velocity profile. Furthermore, in an actual occupied office environment, the thermal plumes and the supply air diffuser mixed effectively the whole air volume. The maximum air velocity measured was still below 0.25 m/s with the extremely high heat gain of 164 W/m{sup 2}. The results demonstrate that analysis methods were the interaction of convection flow and jet are not taken into account could not accurately describe air movement and draught risk in the occupied room space. (author)

Prevalence and causative agents of superficial mycoses in a textile factory in Adana, Turkey.

Science.gov (United States)

Celik, E; Ilkit, M; Tanir, F

2003-09-01

This study was carried out in a textile factory settled in the city center of Adana, Turkey. The workers were evaluated for the presence of superficial mycoses and the interaction of their working environment or working condition. A total of 431 textile workers were included in the study, with a male to female ratio of 378 (87.7%) to 53 (12.3%) and an age range of 19-52 (mean: 33.7 +/- 6.8). Direct examination and/or culture revealed superficial mycoses in 73 (16.9%) workers, among them 56 (76.7%) were classified as dermatophytoses, 8 (11.0%) as Pityriasis versicolor while in nine (12.3%) of the cases, no causative agent could be determined. Trichophyton rubrum (57.1%) and T. mentagrophytes (42.9%) were the two species isolated on culture. This study emphasized that textile workers should be admitted as a risk group for superficial mycoses, especially tinea pedis.

A Novel Technique of Supra Superficial Musculoaponeurotic System Hyaluronic Acid Injection for Lower Face Lifting

OpenAIRE

Sahawatwong, Sinijchaya; Sirithanabadeekul, Punyaphat; Patanajareet, Vasiyapha; Wattanakrai, Penpun; Thanasarnaksorn, Wilai

2016-01-01

Background: Various methods attempting to correct sagging of the lower face focus mainly on manipulation of the superficial musculoaponeurotic System. Each technique has its own limitation. The authors propose a relatively simple, conservative method utilizing hyaluronic acid injection just above the superficial musculoaponeurotic System. Objective: To address a novel hyaluronic injection technique to lift the lower face. Methods: Details of the injection techniques are described. The Positio...

High dose rate brachytherapy for superficial cancer of the esophagus

International Nuclear Information System (INIS)

Maingon, Philippe; D'Hombres, Anne; Truc, Gilles; Barillot, Isabelle; Michiels, Christophe; Bedenne, Laurent; Horiot, Jean Claude

2000-01-01

Purpose: We analyzed our experience with external radiotherapy, combined modality treatment, or HDR brachytherapy alone to limited esophageal cancers. Methods and Materials: From 1991 to 1996, 25 patients with limited superficial esophagus carcinomas were treated by high dose rate brachytherapy. The mean age was 63 years (43-86 years). Five patients showed superficial local recurrence after external radiotherapy. Eleven patients without invasion of the basal membrane were staged as Tis. Fourteen patients with tumors involving the submucosa without spreading to the muscle were staged as T1. Treatment consisted of HDR brachytherapy alone in 13 patients, external radiotherapy and brachytherapy in 8 cases, and concomitant chemo- and radiotherapy in 4 cases. External beam radiation was administered to a total dose of 50 Gy using 2 Gy daily fractions in 5 weeks. In cases of HDR brachytherapy alone (13 patients), 6 applications were performed once a week. Results: The mean follow-up is 31 months (range 24-96 months). Twelve patients received 2 applications and 13 patients received 6 applications. Twelve patients experienced a failure (48%), 11/12 located in the esophagus, all of them in the treated volume. One patient presented an isolated distant metastasis. In the patients treated for superficial recurrence, 4/5 were locally controlled (80%) by brachytherapy alone. After brachytherapy alone, 8/13 patients were controlled (61%). The mean disease-free survival is 14 months (1-36 months). Overall survival is 76% at 1 year, 37% at 2 years, and 14% at 3 years. Overall survival for Tis patients is 24% vs. 20% for T1 (p 0.83). Overall survival for patients treated by HDR brachytherapy alone is 43%. One patient presented with a fistula with local failure after external radiotherapy and brachytherapy. Four stenosis were registered, two were diagnosed on barium swallowing without symptoms, and two required dilatations. Conclusion: High dose rate brachytherapy permits the treating

Superficial skin infections and the use of topical and systemic ...

African Journals Online (AJOL)

Superficial bacterial infections of the skin are very common. With the increasing burden of human immunodeficiency virus (HIV), this is likely to worsen. Examples of such infections include impetigo, erysipelas, cellulitis, ecthyma, furuncles, carbuncles and subcutaneous abscesses. Common causative organisms are ...

A parametric study of microjet assisted methane/air turbulent flames

International Nuclear Information System (INIS)

Chouaieb, Sirine; Kriaa, Wassim; Mhiri, Hatem; Bournot, Philippe

2017-01-01

Highlights: • Microjet assisted methane/air turbulent flames are numerically investigated. • A parametric study concerning the microjet velocity and diameter is carried out. • Previous validation of temperature, mixture fraction and soot is enhanced. • Mixing and soot emission are controlled for higher velocities and lower diameters. • Soot production is reduced by 94% for a microjet velocity equal to 1 m/s. - Abstract: A parametric study of microjet assisted methane/air turbulent flames characteristics is numerically investigated. The Presumed Probability Density Function model and the Discrete Ordinates model are respectively considered for combustion and radiation modeling. The k-epsilon Standard model with Pope Correction is adopted as a turbulence closure model. The two step Tesner model is used to quantify the soot particle production in the flame configuration. Comparison with our previous work using the k-epsilon Realizable model shows that the k-epsilon Standard model with Pope Correction ensures better predictions. The microjet velocity and diameter effects on thermal field, mixing process and soot emission are then discussed. Numerical findings show that the microjet can be used as an efficient tool controlling methane/air turbulent flames. On the one hand, it is shown that the microjet creates an inner flame in the vicinity of the central nozzle exit but does not globally alter the methane/air flame shape. On the other hand, mixing process can be enhanced for high microjet Reynolds number either by increasing the microjet velocity or by decreasing its nozzle diameter for a constant microjet mass flow rate. Soot production can be consequently reduced for low microjet diameter and high velocity values.

Evaluation of anatomy and variations of superficial palmar arch and upper extremity arteries with CT angiography.

Science.gov (United States)

Kaplanoglu, Hatice; Beton, Osman

2017-04-01

To evaluate the abnormalities and variations of the arterial system of upper extremities and superficial palmar arch with computed tomography angiography and to guide the clinician during this procedure. A total of 156 upper extremities of 78 cases were retrospectively analyzed using computed tomography angiography. The study was approved by the local ethics committee of the hospital. From the analysis of the computed tomography angiography images, the following information was recorded; the diameters and abnormalities of radial, ulnar and brachial arteries in both upper extremities, the presence of atherosclerotic changes or stenosis in these arteries, whether the superficial palmar arch was complete or incomplete, and arterial dominance. Also, the computed tomography angiography classification of superficial palmar arch distribution and anatomic configuration was performed. The mean baseline diameters of the radial, ulnar and brachial arteries of the cases were; 2.8 ± 0.6, 2.5 ± 0.7, and 4.7 ± 0.6 mm, respectively. A complete superficial palmar arch was observed in 69.2 % of the right hands and 70.5 % of the left hands. For the superficial palmar arches on the right side, the radial artery was dominant in two and the ulnar artery was dominant in 47 with the remaining showing codominance. On the left side, the radial artery was dominant in one hand, with the ulnar artery being dominant in 49 cases, and in 28 cases, there was codominance. In the superficial palmar arch classification, four of the arches (A-D) were defined as complete and the remaining three (E-G) as incomplete. The current study clarified different variations in palmar circulation and forearm arteries to aid the surgeon during trans-radial or trans-ulnar catheterization, hemodialysis, or coronary artery bypass grafting.

Experimental analysis of humidification process by air passing through seawater

International Nuclear Information System (INIS)

El-Agouz, S.A.; Abugderah, M.

2008-01-01

An experimental investigation of humidification process by air passing through seawater is presented. The main objective of this work was to determine the humid air behaviour through single-stage of heating-humidifying processes. This experimental work studied the influence of the operating conditions such as the water temperature, the headwater difference, the air velocity and the inlet air temperature to evaporator chamber on the vapour content difference and humidification efficiency. Two cases of different inlet conditions of ambient and heated air cases are studied. The experimental results show that, the vapour content difference and the humidification efficiency of the system is strongly affected by the saline water temperature in the evaporator chamber, headwater difference and the air velocity. The inlet air temperature to evaporator chamber variation was found to have a small affect on the vapour content difference. The obtained maximum vapour content difference of the air was about 222 gr w /kg a at 75 deg. C for water and air. The obtained vapour content is high compared to that obtained in literature for single-stage and very similar for multi-stage

Recanalization of superficial femoral artery by retrograde approach via popliteal artery

International Nuclear Information System (INIS)

Kim, Jae Kyu; Kim, Hyung Kil; Yun, Ung; Seo, Jeong Jin; Kang, Heoung Keun

1995-01-01

To recanalize the occlusive lesion of superficial femoral artery at origin site by retrograde approach via popliteal artery. 15 patients, who were poor surgical candidates due to coronary artery disease and who had severe occlusive lesion of superficial femoral artery close to its origin with good distal runoffs to popliteal artery, were selected. Patients were all men and range of age were from 53 years to 66 years (mean age: 63 years). Range of lesion length were from 15 cm to 30 cm (mean length: 22.4 cm). Localization of popliteal artery was done with Doppler stethoscope or 'road-map' DSA. The method of recanalization were transluminal endarterectomy catheter (TEC), TEC and angioplasty, thrombolysoangioplasty (TLA). Retrograde puncture of popliteal artery was done in 15 patients successfully. TEC and PTA was performed in 9 patients, TEC only in 2 patients, and TLA and PTA in 2 patients. During the follow-up period of 5 months to 2 years reocclusion did not occur in 10 patients except for 1 patient with poor cardiac output in whom it occurred 1 day later. Remained 4 patients were lost in follow up. Any neurologic or vascular complication did not occur. Retrograde approach of superficial femoral artery via popliteal artery in patients with difficult vascular intervention by common method provides a useful, alternative recanalization method

Recanalization of superficial femoral artery by retrograde approach via popliteal artery

Energy Technology Data Exchange (ETDEWEB)

Kim, Jae Kyu; Kim, Hyung Kil; Yun, Ung; Seo, Jeong Jin; Kang, Heoung Keun [Chonnam University Medical School, Kwangju (Korea, Republic of)

1995-09-15

To recanalize the occlusive lesion of superficial femoral artery at origin site by retrograde approach via popliteal artery. 15 patients, who were poor surgical candidates due to coronary artery disease and who had severe occlusive lesion of superficial femoral artery close to its origin with good distal runoffs to popliteal artery, were selected. Patients were all men and range of age were from 53 years to 66 years (mean age: 63 years). Range of lesion length were from 15 cm to 30 cm (mean length: 22.4 cm). Localization of popliteal artery was done with Doppler stethoscope or 'road-map' DSA. The method of recanalization were transluminal endarterectomy catheter (TEC), TEC and angioplasty, thrombolysoangioplasty (TLA). Retrograde puncture of popliteal artery was done in 15 patients successfully. TEC and PTA was performed in 9 patients, TEC only in 2 patients, and TLA and PTA in 2 patients. During the follow-up period of 5 months to 2 years reocclusion did not occur in 10 patients except for 1 patient with poor cardiac output in whom it occurred 1 day later. Remained 4 patients were lost in follow up. Any neurologic or vascular complication did not occur. Retrograde approach of superficial femoral artery via popliteal artery in patients with difficult vascular intervention by common method provides a useful, alternative recanalization method.

Carrageenan drying with dehumidified air: drying characteristics and product quality

NARCIS (Netherlands)

Djaeni, M.; Sasongko, S.B.; Prasetyaningrum, Aji A A.A.; Jin, X.; Boxtel, van A.J.B.

2012-01-01

Applying dehumidified air is considered as an option to retain quality in carrageenan drying. This work concerns the effects of operational temperature, air velocity, and carrageenan thickness on the progress of drying and product quality when using dehumidified air. Final product quality and

Study of stream flow effects on bubble motion

International Nuclear Information System (INIS)

Sami, S.S.

1983-01-01

The formation of air bubbles at constant-pressure by submerged orifices was investigated in both quiescent and moving streams inside a vertical tube. Parameters affecting the bubble rise velocity, such as bubble generating frequency and diameter, were studied and analyzed for bubbles rising in a chain and homogeneous mixture. A special technique for measuring bubble motion parameters has been developed, tested, and employed throughout the experimental investigation. The method is based on a water-air impedance variation. Results obtained in stagnant liquid show that increasing the bubble diameter serves to increase bubble rise velocity, while an opposite trend has been observed for stream liquid where the bubble diameter increase reduces the bubble rise velocity. The increase of bubble generation frequency generally increases the bubble rise velocity. Experimental data covered with bubble radial distribution showed symmetrical profiles of bubble velocity and frequency, and the radial distribution of the velocity profiles sometimes has two maxima and one minimum depending on the liquid velocity. Finally, in stagnant liquid, a normalized correlation has been developed to predict the terminal rise velocity in terms of bubble generating frequency, bubble diameter, single bubble rise velocity, and conduit dimensions. Another correlation is presented for forced bubbly flow, where the bubble rise velocity is expressed as a function of bubble generating frequency, bubble diameter, and water superficial velocity

Direct measurements of liquid film roughness for the prediction of annular flow pressure drop

International Nuclear Information System (INIS)

Ashwood, Andrea C.; Schubring, DuWayne; Shedd, Timothy A.

2009-01-01

A vertical two-phase (air-water) test section has been constructed to allow for detailed visualization of flow phenomena in the annular regime. The total internal reflection (TIR) technique for film thickness estimation, originally developed by Shedd and Newell (1998), has been adapted for use in this test section. This technique uses the pattern of diffuse light reflected from the gas-liquid interface to estimate the base film thickness, i.e., the thickness between large liquid waves. Measurement of base film thickness separately from the average film thickness, which couples base film and wave behavior, allows for consideration of separate effects from each of the two zones. A modified Hurlburt-Newell (2000) correlation that separates the flow into these two zones has been generated. Data regarding the relationship between average base film thickness and wave height, along with verification of the base film thickness measured from the TIR technique, were provided by planar laser-induced fluorescence (PLIF). For the present vertical air-water up flows with liquid superficial velocities ranging from 4 to 34 cm s -1 and gas superficial velocities from 35 to 85 m s -1 , the modified Hurlburt-Newell correlation predicts pressure loss to within 10%. (author)

Direct measurements of liquid film roughness for the prediction of annular flow pressure drop

Energy Technology Data Exchange (ETDEWEB)

Ashwood, Andrea C; Schubring, DuWayne; Shedd, Timothy A. [University of Wisconsin, Madison, WI (United States)], e-mail: cashwood@wisc.edu, e-mail: dlschubring@wisc.edu, e-mail: shedd@engr.wisc.edu

2009-07-01

A vertical two-phase (air-water) test section has been constructed to allow for detailed visualization of flow phenomena in the annular regime. The total internal reflection (TIR) technique for film thickness estimation, originally developed by Shedd and Newell (1998), has been adapted for use in this test section. This technique uses the pattern of diffuse light reflected from the gas-liquid interface to estimate the base film thickness, i.e., the thickness between large liquid waves. Measurement of base film thickness separately from the average film thickness, which couples base film and wave behavior, allows for consideration of separate effects from each of the two zones. A modified Hurlburt-Newell (2000) correlation that separates the flow into these two zones has been generated. Data regarding the relationship between average base film thickness and wave height, along with verification of the base film thickness measured from the TIR technique, were provided by planar laser-induced fluorescence (PLIF). For the present vertical air-water up flows with liquid superficial velocities ranging from 4 to 34 cm s{sup -1} and gas superficial velocities from 35 to 85 m s{sup -1}, the modified Hurlburt-Newell correlation predicts pressure loss to within 10%. (author)

Air--sea gaseous exchange of PCB at the Venice lagoon (Italy).

Science.gov (United States)

Manodori, L; Gambaro, A; Moret, I; Capodaglio, G; Cescon, P

2007-10-01

Water bodies are important storage media for persistent organic pollutants (POPs) such as polychlorinated biphenyls (PCBs) and this function is increased in coastal regions because their inputs are higher than those to the open sea. The air-water interface is extensively involved with the global cycling of PCBs because it is the place where they accumulate due to depositional processes and where they may be emitted by gaseous exchange. In this work the parallel collection of air, microlayer and sub-superficial water samples was performed in July 2005 at a site in the Venice lagoon to evaluate the summer gaseous flux of PCBs. The total concentration of PCBs (sum of 118 congeners) in air varies from 87 to 273 pg m(-3), whereas in the operationally defined dissolved phase of microlayer and sub-superficial water samples it varies from 159 to 391 pg L(-1). No significant enrichment of dissolved PCB into the microlayer has been observed, although a preferential accumulation of most hydrophobic congeners occurs. Due to this behaviour, we believe that the modified two-layer model was the most suitable approach for the evaluation of the flux at the air-sea interface, because it takes into account the influence of the microlayer. From its application it appears that PCB volatilize from the lagoon waters with a net flux varying from 58 to 195 ng m(-2)d(-1) (uncertainty: +/-50-64%) due to the strong influence of wind speed. This flux is greater than those reported in the literature for the atmospheric deposition and rivers input and reveals that PCB are actively emitted from the Venice lagoon in summer months.

Modelo Pre-Proceso de predicción de la Calidad Superficial en Fresado a Alta Velocidad basado en Softcomputing

Directory of Open Access Journals (Sweden)

Víctor M. Flores

2011-01-01

Full Text Available Resumen: La calidad superficial es uno de los aspectos más cuidados en la fabricación de piezas. Esta calidad se estima frecuentemente en función a la rugosidad superficial. Trabajos que incorporan técnicas de softcomputing al estudio de la rugosidad superficial en-proceso o pos-proceso son relativamente frecuentes en la literatura. Sin embargo, son casi inexistentes los dedicados al estudio de la rugosidad superficial en pre-proceso, pese a que esto puede ayudar a reducir costes asociados al aseguramiento de la calidad superficial en la producción industrial. En este trabajo se presenta una técnica softcomputing para generar un modelo pre-proceso predictivo de la rugosidad superficial basado en experimentación con características diversas del proceso de fresado a alta velocidad. El modelo de predicción es un clasificador Bayesiano, validado con el método k-fold cross-validation y varios valores de mérito, lo que ha permitido verificar la calidad del modelo predictivo respecto a otros modelos basados en técnicas similares. Palabras clave: Mecanizado a alta velocidad, proceso de fresado a alta velocidad, softcomputing, redes Bayesianas, modelos predictivos

Climatology of tropospheric vertical velocity spectra

Science.gov (United States)

Ecklund, W. L.; Gage, K. S.; Balsley, B. B.; Carter, D. A.

1986-01-01

Vertical velocity power spectra obtained from Poker Flat, Alaska; Platteville, Colorado; Rhone Delta, France; and Ponape, East Caroline Islands using 50-MHz clear-air radars with vertical beams are given. The spectra were obtained by analyzing the quietest periods from the one-minute-resolution time series for each site. The lengths of available vertical records ranged from as long as 6 months at Poker Flat to about 1 month at Platteville. The quiet-time vertical velocity spectra are shown. Spectral period ranging from 2 minutes to 4 hours is shown on the abscissa and power spectral density is given on the ordinate. The Brunt-Vaisala (B-V) periods (determined from nearby sounding balloons) are indicated. All spectra (except the one from Platteville) exhibit a peak at periods slightly longer than the B-V period, are flat at longer periods, and fall rapidly at periods less than the B-V period. This behavior is expected for a spectrum of internal waves and is very similar to what is observed in the ocean (Eriksen, 1978). The spectral amplitudes vary by only a factor of 2 or 3 about the mean, and show that under quiet conditions vertical velocity spectra from the troposphere are very similar at widely different locations.

Optical coherence tomography and polarimetry of superficial skin biopsies

Directory of Open Access Journals (Sweden)

S. R. Utz

2015-01-01

Full Text Available The goal. Of this study was to develop and assess the efficacy of polarization probing of biotissues in vitro. The method is based on the determination of polarization parameters of scattered radiation. Materials and methods. The well-known superficial epidermis stripping method was applied using the Sulfacrylate self-sterile medical adhesive. Small portions of thin layers of the adhesive were applied to slide plates and then to different skin sites. The corneous layer in the normal condition and in case of skin diseases (psoriasis, lichen acuminatus, discoid lupus erythematosus, alopecia, itching and demodectic mange was examined based on the optical coherence tomography (OCT method using the 0CS1300SS device (Thorlabs Inc, USA. Results. The authors obtained pictures visualizing the structural organization of different layers of the epidermis using the superficial epidermis biopsy method in case of lichen acuminatus, hyperkeratosis, itching and other skin diseases. Conclusion. This method ensures non-invasive high-precision measurement of the structure of different layers of the epidermis, which may be useful both for research purposes and practical dermatology.

Velocity Profile measurements in two-phase flow using multi-wave sensors

Science.gov (United States)

Biddinika, M. K.; Ito, D.; Takahashi, H.; Kikura, H.; Aritomi, M.

2009-02-01

Two-phase flow has been recognized as one of the most important phenomena in fluid dynamics. In addition, gas-liquid two-phase flow appears in various industrial fields such as chemical industries and power generations. In order to clarify the flow structure, some flow parameters have been measured by using many effective measurement techniques. The velocity profile as one of the important flow parameter, has been measured by using ultrasonic velocity profile (UVP) technique. This technique can measure velocity distributions along a measuring line, which is a beam formed by pulse ultrasounds. Furthermore, a multi-wave sensor can measure the velocity profiles of both gas and liquid phase using UVP method. In this study, two types of multi-wave sensors are used. A sensor has cylindrical shape, and another one has square shape. The piezoelectric elements of each sensor have basic frequencies of 8 MHz for liquid phase and 2 MHz for gas phase, separately. The velocity profiles of air-water bubbly flow in a vertical rectangular channel were measured by using these multi-wave sensors, and the validation of the measuring accuracy was performed by the comparison between the velocity profiles measured by two multi-wave sensors.

Velocity Profile measurements in two-phase flow using multi-wave sensors

International Nuclear Information System (INIS)

Biddinika, M K; Ito, D; Takahashi, H; Kikura, H; Aritomi, M

2009-01-01

Two-phase flow has been recognized as one of the most important phenomena in fluid dynamics. In addition, gas-liquid two-phase flow appears in various industrial fields such as chemical industries and power generations. In order to clarify the flow structure, some flow parameters have been measured by using many effective measurement techniques. The velocity profile as one of the important flow parameter, has been measured by using ultrasonic velocity profile (UVP) technique. This technique can measure velocity distributions along a measuring line, which is a beam formed by pulse ultrasounds. Furthermore, a multi-wave sensor can measure the velocity profiles of both gas and liquid phase using UVP method. In this study, two types of multi-wave sensors are used. A sensor has cylindrical shape, and another one has square shape. The piezoelectric elements of each sensor have basic frequencies of 8 MHz for liquid phase and 2 MHz for gas phase, separately. The velocity profiles of air-water bubbly flow in a vertical rectangular channel were measured by using these multi-wave sensors, and the validation of the measuring accuracy was performed by the comparison between the velocity profiles measured by two multi-wave sensors.

Shapes and rising velocities of single bubbles rising through an inner subchannel

International Nuclear Information System (INIS)

Tomiyama, Akio; Nakahara, Yusuke; Adachi, Yoshihiro; Hosokawa, Shigeo

2003-01-01

Shapes and velocities of single air bubbles rising through stagnant and flowing waters in an inner subchannel are measured by making use of fluorocarbon tubes. It is confirmed that (1) bubble shapes and motions in the subchannel are by far different from those in simple geometry, and they depend on the ratio λ of the bubble diameter to the subchannel hydraulic diameter, (2) when λ > 0.9, a part of a bubble intrudes into neighboring subchannels, and thereby a kind of void drift takes place even with a single bubble, (3) the terminal velocity V T of a small bubble (λ T for cell-Taylor bubbles (λ > 0.9) is presented, and (5) the rising velocity V B in laminar an turbulent flow conditions are well evaluated by substituting the proposed V T models and the ratio of the maximum liquid velocity to the mean liquid velocity into the Nicklin correlation. (author)

Antibubbles and fine cylindrical sheets of air

NARCIS (Netherlands)

Beilharz, D.; Guyon, A.; Li, E.Q.; Thoraval, Marie-Jean; Thoroddsen, S.T.

2015-01-01

Drops impacting at low velocities onto a pool surface can stretch out thin hemispherical sheets of air between the drop and the pool. These air sheets can remain intact until they reach submicron thicknesses, at which point they rupture to form a myriad of microbubbles. By impacting a

Measurement of Ambient Air Motion of D. I. Gasoline Spray by LIF-PIV

Science.gov (United States)

Yamakawa, Masahisa; Isshiki, Seiji; Yoshizaki, Takuo; Nishida, Keiya

Ambient air velocity distributions in and around a D. I. gasoline spray were measured using a combination of LIF and PIV techniques. A rhodamine and water solution was injected into ambient air to disperse the fine fluorescent liquid particles used as tracers. A fuel spray was injected into the fluorescent tracer cloud and was illuminated by an Nd: YAG laser light sheet (532nm). The scattered light from the spray droplets and tracers was cut off by a high-pass filter (>560nm). As the fluorescence (>600nm) was transmitted through the high-pass filter, the tracer images were captured using a CCD camera and the ambient air velocity distribution could be obtained by PIV based on the images. This technique was applied to a D. I. gasoline spray. The ambient air flowed up around the spray and entered into the tail of the spray. Furthermore, the relative velocity between the spray and ambient air was investigated.

Mapa de riesgo de temperaturas extremas frías para el sur de la provincia de Buenos Aires usando datos satelitales y de superficie Frost risk map for the south of Buenos Aires province using satellite and surface data

Directory of Open Access Journals (Sweden)

Roberto De Ruyver

2012-06-01

Full Text Available Cerca del 40 % del área sembrada con trigo en Argentina se concentra en el sur de la provincia de Buenos Aires. Los eventos frecuentes de temperaturas extremas frías en la segunda quincena de octubre, coincidentes con un momento fenológico sensible del trigo, provocan daños de importancia en el cultivo. El presente trabajo tiene como objetivo proveer mapas de riesgo de temperaturas extremas frías para el período sensible del cultivo de trigo en esa región. Se utilizó información de los canales 3, 4 y 5 del satélite NOAA de 1,09 km² de resolución espacial, obtenidas en el Instituto de Clima y Agua del INTA-Castelar entre 2005 y 2008, y datos diarios de temperaturas mínimas del período 1961-2008 de 13 estaciones de superficie del Servicio Meteorológico Nacional (SMN y del Instituto Nacional de Tecnología Agropecuaria (INTA. Los resultados muestran que las áreas de mayor riesgo son aquellas que combinan menor altura sobre el nivel del mar y al mismo tiempo mayor distancia al mismo. Esta metodología puede ser extendida a otros cultivos y a otras regiones. Este tipo de análisis constituye una herramienta que puede ser útil en tareas de planificación tanto a nivel estatal como privado.Cold temperature can cause severe damage in crops when a cold front irruption occurs. This is especially true in some specific periods on the growing crops mainly during spring. This work presents frost risk maps for wheat. The region selected was the south of Buenos Aires province in Argentina. Wheat covers almost 2,2 million ha in south Buenos Aires area which represents 40% of the total wheat cultivated in Argentina At the same time, south Buenos Aires area suffers the biggest damage on wheat because of frost during spring time. The study was carried out based on channels 3, 4 and 5 of NOAA satellite images (1,09 km² spatial resolution. Images from 2005 to 2008 were available. Minimum daily temperatures from "Servicio Meteorológico Nacional

Superficial tension: experimental model with simple materials

Directory of Open Access Journals (Sweden)

Tintori Ferreira, María Alejandra

2012-09-01

Full Text Available In this work appears a didactic offer based on an experimental activity using materials of very low cost, orientated to achieving that the student understand and interpret the phenomenon of superficial tension together with the importance of the modeling in sciences. It has as principal aim of education bring the student over to the mechanics of the static fluids and the intermolecular forces, combining scientific contents with questions near to the student what provides an additional motivation to the reflection of the scientific investigation.

Experimental study on liquid velocity in upward and downward two-phase flows

International Nuclear Information System (INIS)

Sun, X.; Paranjape, S.; Kim, S.; Ozar, B.; Ishii, M.

2003-01-01

Local characteristics of the liquid phase in upward and downward air-water two-phase flows were experimentally investigated in a 50.8-mm inner-diameter round pipe. An integral Laser Doppler Anemometry (LDA) system was used to measure the axial liquid velocity and its fluctuations. No effect of the flow direction on the liquid velocity radial profile was observed in single-phase liquid benchmark experiments. Local multi-sensor conductivity probes were used to measure the radial profiles of the bubble velocity and the void fraction. The measurement results in the upward and downward two-phase flows are compared and discussed. The results in the downward flow demonstrated that the presence of the bubbles tended to flatten the liquid velocity radial profile, and the maximum liquid velocity could occur off the pipe centerline, in particular at relatively low flow rates. However, the maximum liquid velocity always occurred at the pipe center in the upward flow. Also, noticeable turbulence enhancement due to the bubbles in the two-phase flows was observed in the current experimental flow conditions. Furthermore, the distribution parameter and the void weighted area-averaged drift velocity were obtained based on the definitions

Time-resolved imaging of a compressible air disc under a drop impacting on a solid surface

KAUST Repository

Li, Erqiang

2015-09-07

When a drop impacts on a solid surface, its rapid deceleration is cushioned by a thin layer of air, which leads to the entrapment of a bubble under its centre. For large impact velocities the lubrication pressure in this air layer becomes large enough to compress the air. Herein we use high-speed interferometry, with 200 ns time-resolution, to directly observe the thickness evolution of the air layer during the entire bubble entrapment process. The initial disc radius and thickness shows excellent agreement with available theoretical models, based on adiabatic compression. For the largest impact velocities the air is compressed by as much as a factor of 14. Immediately following the contact, the air disc shows rapid vertical expansion. The radial speed of the surface minima just before contact, can reach 50 times the impact velocity of the drop.

Wire-Mesh Tomography Measurements of Void Fraction in Rectangular Bubble Columns

International Nuclear Information System (INIS)

Reddy Vanga, B.N.; Lopez de Bertodano, M.A.; Zaruba, A.; Prasser, H.M.; Krepper, E.

2004-01-01

Bubble Columns are widely used in the process industry and their scale-up from laboratory scale units to industrial units have been a subject of extensive study. The void fraction distribution in the bubble column is affected by the column size, superficial velocity of the dispersed phase, height of the liquid column, size of the gas bubbles, flow regime, sparger design and geometry of the bubble column. The void fraction distribution in turn affects the interfacial momentum transfer in the bubble column. The void fraction distribution in a rectangular bubble column 10 cm wide and 2 cm deep has been measured using Wire-Mesh Tomography. Experiments were performed in an air-water system with the column operating in the dispersed bubbly flow regime. The experiments also serve the purpose of studying the performance of wire-mesh sensors in batch flows. A 'wall peak' has been observed in the measured void fraction profiles, for the higher gas flow rates. This 'wall peak' seems to be unique, as this distribution has not been previously reported in bubble column literature. Low gas flow rates yielded the conventional 'center peak' void profile. The effect of column height and superficial gas velocity on the void distribution has been investigated. Wire-mesh Tomography also facilitates the measurement of bubble size distribution in the column. This paper presents the measurement principle and the experimental results for a wide range of superficial gas velocities. (authors)

Superficially located enlarged lymphoid follicles characterise nodular gastritis.

Science.gov (United States)

Okamura, Takuma; Sakai, Yasuhiro; Hoshino, Hitomi; Iwaya, Yugo; Tanaka, Eiji; Kobayashi, Motohiro

2015-01-01

Nodular gastritis is a form of chronic Helicobacter pylori gastritis affecting the gastric antrum and characterised endoscopically by the presence of small nodular lesions resembling gooseflesh. It is generally accepted that hyperplasia of lymphoid follicles histologically characterises nodular gastritis; however, quantitative analysis in support of this hypothesis has not been reported. Our goal was to determine whether nodular gastritis is characterised by lymphoid follicle hyperplasia.The number, size, and location of lymphoid follicles in nodular gastritis were determined and those properties compared to samples of atrophic gastritis. The percentages of high endothelial venule (HEV)-like vessels were also evaluated.The number of lymphoid follicles was comparable between nodular and atrophic gastritis; however, follicle size in nodular gastritis was significantly greater than that seen in atrophic gastritis. Moreover, lymphoid follicles in nodular gastritis were positioned more superficially than were those in atrophic gastritis. The percentage of MECA-79 HEV-like vessels was greater in areas with gooseflesh-like lesions in nodular versus atrophic gastritis.Superficially located hyperplastic lymphoid follicles characterise nodular gastritis, and these follicles correspond to gooseflesh-like nodular lesions observed endoscopically. These observations suggest that MECA-79 HEV-like vessels could play at least a partial role in the pathogenesis of nodular gastritis.

Superficial corneal crosslinking during laser in situ keratomileusis.

Science.gov (United States)

Seiler, Theo G; Fischinger, Isaak; Koller, Tobias; Derhartunian, Viktor; Seiler, Theo

2015-10-01

To determine the safety of superficial corneal crosslinking after laser in situ keratomileusis (LASIK). Institut für Refraktive und Ophthalmo-Chirurgie, Zurich, Switzerland. Prospective study. Eyes with an ectasia risk score of 2 or higher were treated with standard LASIK (90 μm flap) for myopia correction, after which a rapid corneal crosslinking was performed in the interface (riboflavin 0.5% for 2 minutes, 9 mW/cm(2) for 5 minutes) (Group 1). The follow-up was up to 1 year. The prevalence of complications was statistically compared with that in a group of eyes matched regarding age, sex, and attempted refractive correction that were treated with standard LASIK only (Group 2). One month postoperatively, 5 eyes in Group 1 lost 1 line of corrected distance visual acuity (CDVA) compared with 1 eye in Group 2 (P rate of less than 5%. The refractive success was identical in both groups. Early postoperative complications such as erosions (16%), diffuse lamellar keratitis (DLK) stage 1 (38%), and DLK stage 2 (5%) were statistically significantly more frequent after superficial corneal crosslinking, leading to a statistically significantly reduced uncorrected distance visual acuity at 1 month (P interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Can sparing of the superficial contralateral parotid lobe reduce xerostomia following radiotherapy for head and neck cancer?

Science.gov (United States)

Nevens, Daan; Nuyts, Sandra

2017-12-01

The purpose of this study is to see whether sparing the superficial contralateral parotid lobe can help limiting xerostomia following radiotherapy for head and neck cancer. 88 patients that were included in two prospective randomized studies were analysed in the current study. Using the dosimetry of both the parotid glands, we divided our patients in four groups. Group 1 includes patients where we were able to reduce the radiation dose below the threshold in order to spare both the ipsilateral and contralateral parotid glands, Group 2 consists of patients where only the contralateral parotid gland could be spared. Group 3 consists of patients where only the contralateral superficial parotid lobe could be spared, while in Group 4 not even the contralateral superficial lobe could be spared. When we compared Group 1 and Group 2, we did not observe a significant difference between both groups in terms of xerostomia scores at 6 or 12 months. When we compared these groups with Group 3, we observed significant differences with more xerostomia in Group 3 where only the contralateral superficial lobe was spared. A significant difference was also observed between Group 3 and Group 4 with more xerostomia in Group 4. Sparing of just one superficial parotid lobe results in less xerostomia when compared to not sparing any lobe of both parotid glands. Advances in knowledge: When sparing of the whole contralateral parotid gland is not possible, delineating both the superficial parotid glands and trying to spare at least one of them can mean a way forward in limiting xerostomia in head and neck cancer patients treated with radiotherapy.

Two-phase air-water stratified flow measurement using ultrasonic techniques

International Nuclear Information System (INIS)

Fan, Shiwei; Yan, Tinghu; Yeung, Hoi

2014-01-01

In this paper, a time resolved ultrasound system was developed for investigating two-phase air-water stratified flow. The hardware of the system includes a pulsed wave transducer, a pulser/receiver, and a digital oscilloscope. The time domain cross correlation method is used to calculate the velocity profile along ultrasonic beam. The system is able to provide velocities with spatial resolution of around 1mm and the temporal resolution of 200μs. Experiments were carried out on single phase water flow and two-phase air-water stratified flow. For single phase water flow, the flow rates from ultrasound system were compared with those from electromagnetic flow (EM) meter, which showed good agreement. Then, the experiments were conducted on two-phase air-water stratified flow and the results were given. Compared with liquid height measurement from conductance probe, it indicated that the measured velocities were explainable

AXAOTHER XL -- A spreadsheet for determining doses for incidents caused by tornadoes or high-velocity straight winds

International Nuclear Information System (INIS)

Simpkins, A.A.

1996-09-01

AXAOTHER XL is an Excel Spreadsheet used to determine dose to the maximally exposed offsite individual during high-velocity straight winds or tornado conditions. Both individual and population doses may be considered. Potential exposure pathways are inhalation and plume shine. For high-velocity straight winds the spreadsheet has the capability to determine the downwind relative air concentration, however for the tornado conditions, the user must enter the relative air concentration. Theoretical models are discussed and hand calculations are performed to ensure proper application of methodologies. A section has also been included that contains user instructions for the spreadsheet

Investigation of Superficial Resistance of Different Purity Copper at Boiling Nitrogen Temperature Depending on Treatment of Current-Conducting Layer

International Nuclear Information System (INIS)

Kutovoj, V.A.; Nikolaenko, A.A.; Stoev, P.I.

2007-01-01

Results of this scientific work show influence of annealing temperature and deformation degree of initial MOB copper and after electron beam refining on superficial resistance at temperature of boiling nitrogen. It is shown, that 30 % deformation and annealing in 873...923 K temperature range results in appreciable reduction of superficial resistance at the investigated samples of copper. The lowest values of superficial resistance after thermal and mechanical treatment were observed in the samples after electron beam refinement

The Contaminant Distribution in a Ventilated Room with Different Air Terminal Devices

DEFF Research Database (Denmark)

Heiselberg, Per; Nielsen, Peter V.

The room ventilation is investigated for three different air terminal devices under isothermal conditions. Velocity distribution in the occupied zone is measured for each air terminal device at different air exchange rates. The maximum air exchange rate is determined on the base of both the throw...... of the jets and the comfort requirements applied to measured air velocities in the occupied zone. Normalized concentration distribution in the test room is determined along a vertical line through the middle of the room as a function of the air exchange rate and the density of the tracer gas. The relative...... ventilation efficiency, , based on the room average concentration is also determined as a function of the air exchange rate and the density of the tracer gas. The influence from the position of the return opening on the relative ventilation efficiency is found for one air terminal device....

Outcome of superficial squamous cell carcinoma of the esophagus: a clinicopathological study

Directory of Open Access Journals (Sweden)

Maria Aparecida Coelho de Arruda Henry

2013-05-01

Full Text Available PURPOSE: To analyze the clinicopathological features and outcome of patients with pathologically proven superficial squamous cell carcinoma of the esophagus. METHODS: A total of 234 consecutive cases of esophageal carcinoma in a 15-year period were reviewed. RESULTS: Superficial esophageal cancer was found in five patients (2.1%. They were four men and one woman and the mean age was 52.5 years. Smoking and alcohol were the main risk factors. Achalasia due to Chagas disease occurred in one patient and a second primary tumor developed in the larynx in another patient. Four patients underwent esophagectomy and one patient received chemoradiotherapy. The histopathologic diagnosis was of squamous cell carcinoma in all cases. Intramucosal tumor (Tis was identified in three cases and superficially invasive carcinoma in two cases. Four patients are free of disease with survival times of two, four, six and nine years. The patient who developed laryngeal cancer died six years after esophagectomy. CONCLUSION: Long-term survival in patients with esophageal cancer is related to early diagnosis. Therefore, a less aggressive surgical approach, such as endoscopic resection, may be a good option for these patients, if depth of tumor invasion can be accurately predicted by the new imaging tools.

Harvest Date Influences Superficial Scald Development in Granny Smith Apples During Long Term Storage

OpenAIRE

ERKAN, Mustafa; PEKMEZCİ, Mustafa

2014-01-01

The effects of harvest dates on superficial scald development and postharvest quality in 'Granny Smith' apples (Malus domestica Borkh.) were investigated. Apples were harvested at 15-day intervals during 2 consecutive years (2000-2001) and stored at 0 °C with 90% relative humidity for 8 months. At the end of the 8 - month storage period plus an additional 1 week at 20 °C the percentage of superficial scald was lower (24.4%) in late harvested (November 15) apples than in ap...

Flow Perturbation Mediates Neutrophil Recruitment and Potentiates Endothelial Injury via TLR2 in Mice – Implications for Superficial Erosion

Science.gov (United States)

Franck, Grégory; Mawson, Thomas; Sausen, Grasiele; Salinas, Manuel; Masson, Gustavo Santos; Cole, Andrew; Beltrami-Moreira, Marina; Chatzizisis, Yiannis; Quillard, Thibault; Tesmenitsky, Yevgenia; Shvartz, Eugenia; Sukhova, Galina K.; Swirski, Filip K.; Nahrendorf, Matthias; Aikawa, Elena; Croce, Kevin J.; Libby, Peter

2017-01-01

Rationale Superficial erosion currently causes up to a third of acute coronary syndromes (ACS), yet we lack understanding of its mechanisms. Thrombi due to superficial intimal erosion characteristically complicate matrix-rich atheromata in regions of flow perturbation. Objective This study tested in vivo the involvement of disturbed flow, and of neutrophils, hyaluronan, and TLR2 ligation in superficial intimal injury, a process implicated in superficial erosion. Methods and Results : In mouse carotid arteries with established intimal lesions tailored to resemble the substrate of human eroded plaques, acute flow perturbation promoted downstream endothelial cell (EC) activation, neutrophil accumulation, EC death and desquamation, and mural thrombosis. Neutrophil loss-of-function limited these findings. TLR2 agonism activated luminal ECs, and deficiency of this innate immune receptor decreased intimal neutrophil adherence in regions of local flow disturbance, reducing EC injury and local thrombosis (p<0.05). Conclusions These results implicate flow disturbance, neutrophils, and TLR2 signaling as mechanisms that contribute to superficial erosion, a cause of ACS of likely growing importance in the statin era. PMID:28428204

Modeling of air flow through a narrow crack

International Nuclear Information System (INIS)

Trojek, T.; Cechak, T.; Moucka, L.; Fronka, A.

2004-01-01

Radon transport in dwellings is governed to a significant extent by pressure differences and properties of transport pathways. A model of air flow through narrow cracks was created in order to facilitate prediction of air velocity and air flow. Theoretical calculations, based on numerical solution of a system of differential equations, were compared with measurements carried out on a window crack. (P.A.)

Theoretical analysis and semianalytical solutions for a turbulent buoyant hydrogen-air jet

KAUST Repository

El-Amin, Mohamed; Sun, S.; Salama, Amgad

2012-01-01

Semianalytical solutions are developed for turbulent hydrogen-air plume. We derived analytical expressions for plume centerline variables (radius, velocity, and density deficit) in terms of a single universal function, called plume function. By combining the obtained analytical expressions of centerline variables with empirical Gaussian expressions of the mean variables, we obtain semianalytical expressions for mean quantities of hydrogen-air plume (velocity, density deficit, and mass fraction).

Air Distribution in a Room with Ceiling-Mounted Diffusers

DEFF Research Database (Denmark)

Nielsen, Peter V.; Heby, Thomas; Moeller-Jensen, Bertil

2006-01-01

. The characteristics of the air distribution systems are addressed by analysing the acceptable conditions for the supply flow rate and the temperature difference for the different systems. The paper shows that an air distribution system with ceiling-mounted air terminal units is able to generate comfortable velocity...... with swirling flow generates a flow pattern in the room which is rather uninfluenced by the thermal load. The flow is highly mixed above the occupied zone and the air movement penetrates the occupied zone close to the walls. All systems are tested in the same room with the same heat load consisting of two...... manikins, each sitting at a desk, two pc's and two desk lamps producing a total heat load of 480 W. The design of the air distribution system is in all five cases based on flow elements from the diffuser, a maximum velocity assumption and a critical vertical temperature gradient in the room...

STUDY OF GAS SEPARATION PROCESS BY DYNAMIC ADSORPTION IN FIXED BED

Directory of Open Access Journals (Sweden)

Ioan Solomon

2010-10-01

Full Text Available An experimental study of mass transfer at gas separation by dynamic adsorption in fixed bed of impregnated silica gel is presented in this work. By means of a mathematical model based on constants and coefficient easy to evaluate, the distributions of adsorbate concentration in gas and solid phases were determined as a function of time and throughout the height of the fixed bed, under isothermal conditions.With this aim, water vapors from air were adsorbed in a fixed bed of impregnated silica gel. The values of the volumetric mass transfer coefficient, Kv, were determined experimentally at several values of air superficial velocity, an air relative humidity of 69�20at 38 °C. The influence of the gas flow velocity and initial water concentration in adsorbent on the distribution of water concentration in both phases was established as a function of time and throughout the height of the fixed bed. The results obtained allow one to determination of the local adsorption rate.

Studio della superficie degli impianti dentali in titanio: La nanotecnologia nella valutazione delle nuove superfici implantari in rapporto all'osteointegrazione dei mascellari

OpenAIRE

Ricci, Emanuele

2015-01-01

Il presente lavoro parte dalla descrizione dei processi di rimodellamento osseo mascellare a seguito della perdita di elementi dentari e la successiva riabilitazione mediante impianto dentale osteointegrato. Approfondiremo proprio i complessi aspetti dell’osteointegrazione su superfici implantari in titanio sia a livello micro che macroscopico. Nel campo dell’implantologia, infatti, il titanio risulta essere il materiale maggiormente impiegato in virtù della sua eccellente biocompatibilità...

Blow capacity of an air curtain; Hoe hard denkt u dat een luchtgrodijn moet blazen?

Energy Technology Data Exchange (ETDEWEB)

Cremers, B.E. [Biddle, Kootstertille (Netherlands)

2003-03-01

In winter, the heat capacity of a conventional air curtain can often be increased by adjusting the speed of its outlet velocity. This article demonstrates that for various reasons, it is better to adjust the width of the outlet if you need to boost the heat level rather than the outlet velocity. It also describes the benefits of this CA (Constant Air Velocity) Technology in the interests of energy conservation and comfort. [Dutch] In de winter wordt de warmtecapaciteit van een conventioneel luchtgordijn vaak verhoogd door de uitblaassnelheid aan te passen. Dit artikel toont aan dat het om meerdere redenen beter is om bij een hogere warmtebehoefte de uitblaasbreedte aan te passen in plaats van de uitblaassnelheid. Daarnaast beschrijft het de voordelen van deze CA-technologie (Constant Air velocity) wat betreft energieverbruik en comfort.

Reverse Ballistic Air Gun Facility

Data.gov (United States)

Federal Laboratory Consortium — This custom-designed facility houses a suite of three air guns capable of generating accelerations up to 100,000 Gs and velocities up to 2,000 ft/s. In addition to a...

Advanced air distribution

DEFF Research Database (Denmark)

Melikov, Arsen Krikor

2011-01-01

The aim of total volume air distribution (TVAD) involves achieving uniform temperature and velocity in the occupied zone and environment designed for an average occupant. The supply of large amounts of clean and cool air are needed to maintain temperature and pollution concentration at acceptable...... levels in the entire space, leading to increased energy consumption and the use of large and costly HVAC and duct systems. The performance of desk installed PV combined with background TVAD used for room temperature control has been studied in an office building located in a hot and humid climate....... Ventilation in hospitals is essential to decrease the risk of airborne cross-infection. At present, mixing air distribution at a minimum of 12 ach is used in infection wards. Advanced air distribution has the potential to aid in achieving healthy, comfortable and productive indoor environments at levels...

Influence of cross-sectional ratio of down comer to riser on the efficiency of liquid circulation in loop air lift bubble column

Science.gov (United States)

Yamamoto, Tatsumi; Kawasaki, Hiroyuki; Mori, Hidetoshi

2017-11-01

Loop type bubble columns have good performance of liquid circulation and mass transfer by airlift effect, where the liquid circulation time is an important measurable characteristic parameter. This parameter is affected by the column construction, the aspect ratio of the column, the cross-sectional area ratio of down comer to riser (R), and the superficial gas velocity in the riser (UGR). In this work, the mean gas holdup and the liquid circulation time (TC) have been measured in four types of loop airlift type bubble column: concentric tube internal loop airlift type, rectangular internal loop airlift type, external loop airlift type, external loop airlift with separator. Air and tap water were used as gas and liquid phase, respectively. The results have demonstrated that the mean gas holdup in riser increases in proportion to UGR, and that it in downcomer changes according to the geometric parameters of each bubble column. TC has been found to conform to an empirical equation which depends on UGR and the length of draft tube or division plate in the region of 0.33 < R < 1.

Anatomía de la arteria temporal superficial: importancia quirúrgica: estudio piloto en cadáveres

Directory of Open Access Journals (Sweden)

J.J. Pradel-Mora

2015-03-01

Full Text Available El conocimiento preciso de los patrones vasculares permite mejorar los resultados de la reconstrucción regional del pabellón auricular y el diseño de colgajos regionales dependientes de la arteria temporal superficial para la reconstrucción facial. En México, no contamos en la actualidad con descripciones anatómicas de las variantes vasculares normales de la arteria temporal superficial. El objetivo de este trabajo es la descripción de las variantes anatómicas de la arteria temporal superficial a través de la disección de este vaso en 12 regiones tempo-parieto-occipitales en cadáveres. Nuestros resultados muestran que la arteria temporal superficial siempre se divide en dos ramas, una anterior y otra posterior, la distribución de ésta se sitúa en el cuarto más posterior de la región temporal, con una bifurcación alta. La distribución de la anatomía vascular, tomando en cuenta el calibre mayor de la arteria temporal superficial con respecto a la arteria auricular posterior, la ausencia de esta última en 4 de las regiones estudiadas, así como la distancia de dichos vasos con respecto al conducto auditivo externo, sugieren que en nuestra población la irrigación del pabellón auricular depende de la arteria temporal superficial, restándole importancia a la aportación del riego sanguíneo de esta región por parte de la arteria auricular posterior. Nuestro estudio arroja resultados que indican la existencia de variaciones importantes en la anatomía vascular regional que justifican la realización de estudios posteriores que permitan una descripción mas detallada de la misma para aumentar el éxito de las intervenciones quirúrgicas.

APLICAÇÃO DE GEOTÊXTEIS BIODEGRADÁVEIS NA REDUÇÃO DO ESCOAMENTO SUPERFICIAL E CONTROLE DA EROSÃO SUPERFICIAL, UBERLÂNDIA/MG

Directory of Open Access Journals (Sweden)

José Fernando Rodrigues Bezerra

2011-12-01

Full Text Available Esse artigo aborda a utilização dos geotêxteis biodegradáveis no controle do escoamento superficial e perda de sedimentos. Para alcançar esse objetivo, uma estação experimental foi construída na Fazenda do Glória, no município de Uberlândia, Minas Gerais, a qual ficou funcionando no período de 18/11/2005 a 30/03/2006. Duas parcelas foram construídas, com as seguintes características: medidas de 1m x 10m, com uma calha, na parte inferior de cada parcela, para coletar água do escoamento superficial e sedimentos transportados. Uma das parcelas ficou sem cobertura vegetal durante todo o monitoramento e a outra recebeu a proteção dos geotêxteis (Buriti e sementes de gramínea. Durante os cinco meses de monitoramento, houve um total de 1.087,22mm de chuva. Na parcela sem cobertura vegetal, o total de escoamento superficial foi de 297,16L m-2, enquanto na parcela com os geotêxteis com gramíneas foi de 123,92L m-2, ou seja, mais da metade do total de escoamento da parcela sem proteção. Em termos da produção de sedimentos, a diferença foi ainda mais significativa; na parcela sem proteção dos geotêxteis, o total de solo erodido foi de 19.778,13g m-2, enquanto na outra parcela, o total foi de apenas 1.317,92g m-2. Esses resultados mostram que os geotêxteis construídos com fibra de Buriti podem ser bem eficientes no controle da erosão

CRITERIOS PARA LA EVALUACIÓN DE SUPERFICIES MULTITÁCTILES Y SUS APLICACIONES

Directory of Open Access Journals (Sweden)

YENNY A. MÉNDEZ

2012-06-01

Full Text Available Las superficies multitáctiles son tecnologías que empiezan a tener un elevado uso. Se toman como referentes aspectos utilizados para la evaluación de usabilidad de sistemas interactivos, así como las característicasque los investigadores y desarrolladores sugieren que deberían tener las superficies multitáctiles y las aplicaciones desarrolladas. Se presenta una propuesta inicial de criterios que deberían tenerse en cuenta para incluir  aspectos de ergonomía, usabilidad y colaboración en el momento de realizar evaluaciones para estas tecnologías. Se ilustra cómo se pueden aplicar los criterios propuestos a través de un caso de estudio que cuenta con resultados promisorios.

Measuring average angular velocity with a smartphone magnetic field sensor

Science.gov (United States)

Pili, Unofre; Violanda, Renante

2018-02-01

The angular velocity of a spinning object is, by standard, measured using a device called a tachometer. However, by directly using it in a classroom setting, the activity is likely to appear as less instructive and less engaging. Indeed, some alternative classroom-suitable methods for measuring angular velocity have been presented. In this paper, we present a further alternative that is smartphone-based, making use of the real-time magnetic field (simply called B-field in what follows) data gathering capability of the B-field sensor of the smartphone device as the timer for measuring average rotational period and average angular velocity. The in-built B-field sensor in smartphones has already found a number of uses in undergraduate experimental physics. For instance, in elementary electrodynamics, it has been used to explore the well-known Bio-Savart law and in a measurement of the permeability of air.

The role of settling velocity formulation in the determination of gully pot trapping efficiency: comparison between analytical and experimental data.

Science.gov (United States)

Ciccarello, Annalisa; Bolognesi, Andrea; Maglionico, Marco; Artina, Sandro

2012-01-01

Roadside gully pots are the connecting points between surface runoff and the underground drainage network; therefore they can be considered as the most superficial component of urban drainage systems. Gully pots are supposed to trap particulate matter washed off the catchment surface, but also to collect and convey stormwater into the network. The continuous accumulation of particulate matter results in a progressive loss of the gully pot hydraulic conveyance, thereby increasing the probability of urban flooding during rainstorm events. This study has therefore the objective to determine which variables influence the gully pot capability of retaining solids (efficiency), both experimentally and analytically. Several laboratory tests have been performed on a simple plastic gully pot, with different inflow rates and using both mono and hetero-disperse particle samples. Particular attention has been given to the influence exerted by the way particle settling velocity is expressed: efficiency has been analytically determined by means of multiple settling velocity formulas proposed by various authors and eventually compared to experimental data. Results deriving from the adoption of each single settling velocity formula have been extensively analysed, showing fairly different outcomes.

Analyses of superficial and depth doses in intraoral radiology

Energy Technology Data Exchange (ETDEWEB)

Silva Santos de Oliveira, C.; Morais, R.P. de; Nascimento Souza, D. do [Universidade Federal de Sergipe - CCET - Dept. de Fisica, Sao Cristovao, SE (Brazil)

2006-07-01

In this work dosimetric analysis using thermoluminescence technique to study the beams characteristics of x-rays employed in dental radiology has been carried out. The obtained results with CaSO{sub 4}:Dy thermoluminescent dosimeters (TLD) were compared to the doses obtained with parallel-plates ionization chamber. Dosimetric evaluations were also done using radiographic films of large dimensions. The x-rays equipments analyzed were installed in the radiological services of Odontology Department of Sergipe Federal University (U.F.S.). Depending on the anatomical region to be examined the proper exposure time was select, for a fix voltage of 70 kV. The results with TLD and ionization chamber have been determined to female and male individuals. The intraoral regions analysed were the peri apical of the incisors, molar and pre-molar teeth and the occlusive region. These regions were simulated using acrylic plates absorbers installed on the film packet holder. The evaluation of the depth doses in the intraoral tissue was obtained using different acrylic plate thickness. The air kerma values have been evaluated with the ionization chamber located in the dental cone exit of the x-rays equipments. The integrated areas of the thermoluminescent glow curves showed coherent values when compared to the ones obtained with the ionization chamber and both methods presented a linear dependence with the exposition time. The analyses with films have allowed the evaluation of the beam scattering in the simulator apparatus. The studies had proven that the analysis of superficial dose and in depth used in dental radiology can be carried with thermoluminescent dosimeters. (authors)

Analyses of superficial and depth doses in intraoral radiology

International Nuclear Information System (INIS)

Silva Santos de Oliveira, C.; Morais, R.P. de; Nascimento Souza, D. do

2006-01-01

In this work dosimetric analysis using thermoluminescence technique to study the beams characteristics of x-rays employed in dental radiology has been carried out. The obtained results with CaSO 4 :Dy thermoluminescent dosimeters (TLD) were compared to the doses obtained with parallel-plates ionization chamber. Dosimetric evaluations were also done using radiographic films of large dimensions. The x-rays equipments analyzed were installed in the radiological services of Odontology Department of Sergipe Federal University (U.F.S.). Depending on the anatomical region to be examined the proper exposure time was select, for a fix voltage of 70 kV. The results with TLD and ionization chamber have been determined to female and male individuals. The intraoral regions analysed were the peri apical of the incisors, molar and pre-molar teeth and the occlusive region. These regions were simulated using acrylic plates absorbers installed on the film packet holder. The evaluation of the depth doses in the intraoral tissue was obtained using different acrylic plate thickness. The air kerma values have been evaluated with the ionization chamber located in the dental cone exit of the x-rays equipments. The integrated areas of the thermoluminescent glow curves showed coherent values when compared to the ones obtained with the ionization chamber and both methods presented a linear dependence with the exposition time. The analyses with films have allowed the evaluation of the beam scattering in the simulator apparatus. The studies had proven that the analysis of superficial dose and in depth used in dental radiology can be carried with thermoluminescent dosimeters. (authors)

Air cleaning efficiency of deodorant materials under dynamic conditions: effect of air flow rate

DEFF Research Database (Denmark)

Mizutani, Chiyomi; Bivolarova, Mariya Petrova; Melikov, Arsen Krikor

2014-01-01

Unpleasant odor is a serious problem in hospitals and elderly facilities. One of the unpleasant odors is ammonia originating from human urine and sweat. The air cleaning efficiency of porous activated carbon fiber fabric which has been treated with acid, and porous activated carbon fiber fabric...... mixed with ammonia gas at a concentration of 20 ppm and velocities of 0.05, 0.15, 0.3 and 1.2 m/s. The activated carbon fibers treated with acid had a high deodorizing effect for ammonia (0.8) at a velocity of 0.05 m/s. The deodorizing effect of this material decreased with the increase in the velocity....... The porous activated carbon fiber fabric did not have a deodorant effect....

An experimental investigation of a novel design air humidifier using direct solar thermal heating

International Nuclear Information System (INIS)

Abd-ur-Rehman, Hafiz M.; Al-Sulaiman, Fahad A.

2016-01-01

Highlights: • A novel solar driven multi-stage bubble column humidifier is developed and tested. • Single stage, two stage, and three stage configuration were tested. • Average day round absolute humidity is increased by 9% for 2 stage configuration. • Average day round absolute humidity is increased by 23% for 3 stage configuration. • Air absolute humidity increases up to 26% with the integration of Fresnel lens. - Abstract: In this study, a novel solar heated multi-stage bubble column humidifier is designed and tested. The overall objective of this work is to investigate the main operating parameters of the new humidifier. The study addresses the significance of the perforated plate geometric features, optimum balance of air superficial velocity and water column height, and the influence of inlet water temperature and inlet air relative humidity on the performance of the humidifier. The day round performance of the humidifier is investigated in single stage, two stage, and three stage configuration, in which each configuration was tested with and without the integration of the Fresnel lens. Findings show that the average day round absolute humidity, without Fresnel lens, increased up to 9% for the two stage configuration and 23% for the three stage configuration as compared to the single stage configuration of the humidifier. The integration of the Fresnel lens further increased the absolute humidity up to 25% as compared to the results obtained without the integration of the Fresnel lens under the same prevailing conditions, which is significant. Moreover, the current humidifier shows a higher humidification efficiency in the climatic conditions that have a lower inlet air relative humidity. Furthermore, the finding demonstrates that the newly developed multi-stage bubble column humidifier has better performance as compared to the conventional single stage bubble column humidifier. The findings from this study are of pivotal importance to understand

Remote determination of the velocity index and mean streamwise velocity profiles

Science.gov (United States)

Johnson, E. D.; Cowen, E. A.

2017-09-01

When determining volumetric discharge from surface measurements of currents in a river or open channel, the velocity index is typically used to convert surface velocities to depth-averaged velocities. The velocity index is given by, k=Ub/Usurf, where Ub is the depth-averaged velocity and Usurf is the local surface velocity. The USGS (United States Geological Survey) standard value for this coefficient, k = 0.85, was determined from a series of laboratory experiments and has been widely used in the field and in laboratory measurements of volumetric discharge despite evidence that the velocity index is site-specific. Numerous studies have documented that the velocity index varies with Reynolds number, flow depth, and relative bed roughness and with the presence of secondary flows. A remote method of determining depth-averaged velocity and hence the velocity index is developed here. The technique leverages the findings of Johnson and Cowen (2017) and permits remote determination of the velocity power-law exponent thereby, enabling remote prediction of the vertical structure of the mean streamwise velocity, the depth-averaged velocity, and the velocity index.

An experimental study of the air-side particulate fouling in finned-tube heat exchangers of air conditioners through accelerated tests

International Nuclear Information System (INIS)

Ahn, Young Chull; Cho, Jae Min; Lee, Jae Keun; Lee, Hyun Uk; Ahn, Seung Phyo; Youn, Deok Hyun; Kang, Tae Wook; Ock, Ju Jo

2003-01-01

The air-side particulate fouling in the heat exchangers of HVAC applications degrades the performance of cooling capacity, pressure drop across a heat exchanger, and indoor air quality. Indoor and outdoor air contaminants foul heat exchangers. The purpose of this study is to investigate the fouling characteristics trough accelerated tests. The fouling characteristics are analyzed as functions of a dust concentration (1.28 and 3.84 g/m 3 ), a face velocity (0.5, 1.0, and 1.5 m/s), and a surface condition. The cooling capacity in the slitted finned-tube heat exchangers at the face velocity of 1 m/s decreases about 2% and the pressure drop increases up to 57%. The rate of build-up of fouling is observed to be 3 times slower for this three-fold reduction of dust concentration whilst still approaching the same asymptotic level

Caracterización superficial en fase gas y líquida de carbones activados

Directory of Open Access Journals (Sweden)

Liliana Giraldo Gutierréz

2008-05-01

Full Text Available Se determinó el área superficial de carbones activados obtenidos a partir de cascarilla de café y cáscara de coco, mediante isotermas de adsorción de N2 a 77K. Se compararon los resultados con aquellos obtenidos con un método comúnmente utilizado, el índice de azul de metileno, y se encontró una buena correlación entre las dos áreas determinadas por éste método. Se muestra que los dos métodos permiten realizar un análisis complementario de una superficie porosa./ The superficial area of an activated carbon obtained from coffee husk and coconut shell was determined, by means of isotherms of adsorption of N2 to 77K and the results they area compared with the method of index blue of methylene, finding an good correlation between the two areas determined by this method. This research shows that both methods allow making a complementary analysis of a porous surface.

Molecular Rayleigh Scattering Diagnostic for Dynamic Temperature, Velocity, and Density Measurements

Science.gov (United States)

Mielke, Amy R.; Elam, Kristie A.; Sung, Chi-Jen

2006-01-01

A molecular Rayleigh scattering technique is developed to measure dynamic gas temperature, velocity, and density in unseeded turbulent flows at sampling rates up to 16 kHz. A high power CW laser beam is focused at a point in an air jet plume and Rayleigh scattered light is collected and spectrally resolved. The spectrum of the light, which contains information about the temperature and velocity of the flow, is analyzed using a Fabry-Perot interferometer. The circular interference fringe pattern is divided into four concentric regions and sampled at 1 and 16 kHz using photon counting electronics. Monitoring the relative change in intensity within each region allows for measurement of gas temperature and velocity. Independently monitoring the total scattered light intensity provides a measure of gas density. A low speed heated jet is used to validate the measurement of temperature fluctuations and an acoustically excited nozzle flow is studied to validate velocity fluctuation measurements. Power spectral density calculations of the property fluctuations, as well as mean and fluctuating quantities are presented. Temperature fluctuation results are compared with constant current anemometry measurements and velocity fluctuation results are compared with constant temperature anemometry measurements at the same locations.

Superficial biopsy of the cervix: new technique

Directory of Open Access Journals (Sweden)

Ettore De Girolami

2002-06-01

Full Text Available Cytological examination of the cervix in all patients is considered a necessity. A new technique of superficial biopsy is described and advantages en. numeratedEl Autor presenta una nueva técnica para biopsia superficial, considerando la necesidad de hacer rutinariamente a todas las pacientes el examen citológico del cérvix. La muestra se toma con el extremo de un aplicador cubierto de gaza. Este dispositivo, humedecido previamente en una solución de etanol, metanol y éter etílico, se aplica inmediatamente al cérvix del útero y, dándole un movimiento como el de las manecillas del reloj, se toma la muestra con la que se hacen frotis por aposición que se colorean por el método de Giemsa. Esta técnica ofrece la ventaja de que el tejido en estudio se adhiere perfectamente a la gaza, la cual, con el movimiento de rotación, desprende las células del "os uteri", las que son fijadas al mismo tiempo. La preparación del dispositivo es sumamente sencilla. La prueba resulta de bajo costo como de breve y fácil realizaciónL' Autore prende in considerazione l'utilitá dell' esame citologico del collo dell'utero, fatto rutinariamente a tutte le pazienti. Si descrive una nuova tecnica di biopsia superficiale che oltfe ad offrire dei vantaggi é di poca spesa e si puó eseguire con facilitá ed in breve tempo

Superficial siderosis of the central nervous system due to brachial plexus injury: a case report

International Nuclear Information System (INIS)

Setogutti, Enio Tadashi; Cassuriaga, Jefferson; Valduga, Simone Gianella; Lorenzzoni, Pablo Longhi; Severgnini, Giancarlo Muraro; Feldman, Carlos Jader

2005-01-01

Superficial siderosis can be caused by hemosiderin deposition o the leptomeninges and subpial layers of the neuro-axis due to recurrent subarachnoid haemorrhage. Probable intrathecal bleeding sites must be investigated. In ut t 50% of the patients the bleeding source may be identified and the progression of the disease can be interrupted. In this study, the authors present a case of superficial siderosis of the central nervous system developed two decades after a traumatic lesion of the brachial plexus.(author)

Superficial shell insulation in resting and exercising men in cold water.

Science.gov (United States)

Veicsteinas, A; Ferretti, G; Rennie, D W

1982-06-01

From measurements of subcutaneous fat temperature (Tsf) at known depths below the surface, skin surface temperature (Tsk), and direct skin heat flux (H), the superficial shell isulation (Iss) of the thigh (fat + skin) was calculated as Iss (degrees C.m2.w-1) = (Tsf - Tsk)/H in nine male subjects immersed head out in a well-stirred water bath. Also, at critical water temperature (CWT = 28-33 degrees C), eight of the subjects rested for 3 h, enabling overall maximal tissue insulation (It,max) to be calculated as It,max (degrees C.m2.W-1) = (Tre - Tw)/(0.92 M +/- delta S), where Tre is rectal temperature, Tw is water temperature, M is metabolic rate, and s is loss or gain of body heat. Five subjects performed up to 2 h of mild leg cycling, preceded and followed by 60 min of rest, and both thigh Iss and overall It were measured during exercise. Iss increased from minimal values in Tw greater than 33 degrees C to maximal values (Iss,max) at CWT or below. Iss,max was linearly related to tissue thickness (d) in millimeters of fat plus skin, Iss,max (degrees C.m2.W-1) = 0.0048d-0.0052; r = 0.95, n = 37, and was not influenced by leg exercise up to a metabolic rate of 150 W.m-2 in CWT despite large increases in Tsf and H and large decreases in overall It. The slope of Iss,max vs. depth, 0.0048 degrees C.m2.W-1.mm-1, is almost identical to thermal resistivity of fat in vitro, suggesting that the superficial shell is unperfused in CWT at rest or during mild exercise. When maximal superficial shell insulation (It,ss,max) for the whole body was calculated with allowance for differing fat thicknesses and surface areas of body regions, it could account for only 10-15% of overall It,max at rest and 35-40% of overall It in mild exercise. We suggest that the poorly perfused muscle shell plays a more important role as a defense against cooling at CWT than does the superficial shell (fat + skin), particularly at rest.

XPS response in the corrosion products analysis for copper exposed at clean air environment

International Nuclear Information System (INIS)

Mariaca, L.; Morcillo, M.; Feliu Jr, S.; Gonzalez, J.A.

1998-01-01

In this work is presented the obtained response for superficial analysis technique by X-ray photoelectron spectroscopy (XPS or ESCA), to determine the corrosion products formed during the copper exposure at environment without pollutants (clean air) at 50, 70 and 90 % of relative humidity at 35 Centigrade. One of the copper corrosion products most knew is Cu 2 O. This oxide is formed instantly to be exposed the copper at air. However in function of the exposure time and the relative humidity at it is exposed, the Cu 2 O oxide is transformed at Cu O and Cu(OH) 2 (Author)

Quantifying air distribution, ventilation effectiveness and airborne pollutant transport in an aircraft cabin mockup

Science.gov (United States)

Wang, Aijun

The health, safety and comfort of passengers during flight inspired this research into cabin air quality, which is closely related to its airflow distribution, ventilation effectiveness and airborne pollutant transport. The experimental facility is a full-scale aircraft cabin mockup. A volumetric particle tracking velocimetry (VPTV) technique was enhanced by incorporating a self-developed streak recognition algorithm. Two stable recirculation regions, the reverse flows above the seats and the main air jets from the air supply inlets formed the complicated airflow patterns inside the cabin mockup. The primary air flow was parallel to the passenger rows. The small velocity component in the direction of the cabin depth caused less net air exchange between the passenger rows than that parallel to the passenger rows. Different total air supply rate changed the developing behaviors of the main air jets, leading to different local air distribution patterns. Two indices, Local mean age of air and ventilation effectiveness factor (VEF), were measured at five levels of air supply rate and two levels of heating load. Local mean age of air decreased linearly with an increase in the air supply rate, while the VEF remained consistent when the air supply rate varied. The thermal buoyancy force from the thermal plume generated the upside plume flow, opposite to the main jet flow above the boundary seats and thus lowered the local net air exchange. The airborne transport dynamics depends on the distance between the source and the receptors, the relative location of pollutant source, and air supply rate. Exposure risk was significantly reduced with increased distance between source and receptors. Another possible way to decrease the exposure risk was to position the release source close to the exhaust outlets. Increasing the air supply rate could be an effective solution under some emergency situations. The large volume of data regarding the three-dimensional air velocities was

"A Tale of Two Planes": Deep Versus Superficial Serratus Plane Block for Postmastectomy Pain Syndrome.

Science.gov (United States)

Piracha, Mohammad M; Thorp, Stephen L; Puttanniah, Vinay; Gulati, Amitabh

Postmastectomy pain syndrome (PMPS) is a significant burden for breast cancer survivors. Although multiple therapies have been described, an evolving field of serratus anterior plane blocks has been described in this population. We describe the addition of the deep serratus anterior plane block (DSPB) for PMPS. Four patients with history of PMPS underwent DSPB for anterior chest wall pain. A retrospective review of these patients' outcomes was obtained through postprocedure interviews. Three of the patients previously had a superficial serratus anterior plane block, which was not as efficacious as the DSPB. The fourth patient had a superficial serratus anterior plane that was difficult to separate with hydrodissection but had improved pain control with a DSPB. We illustrate 4 patients who have benefitted from a DSPB and describe indications that this block may be more efficacious than a superficial serratus plane block. Further study is recommended to understand the intercostal nerve branches within the lateral and anterior muscular chest wall planes.

High-velocity two-phase flow two-dimensional modeling

International Nuclear Information System (INIS)

Mathes, R.; Alemany, A.; Thilbault, J.P.

1995-01-01

The two-phase flow in the nozzle of a LMMHD (liquid metal magnetohydrodynamic) converter has been studied numerically and experimentally. A two-dimensional model for two-phase flow has been developed including the viscous terms (dragging and turbulence) and the interfacial mass, momentum and energy transfer between the phases. The numerical results were obtained by a finite volume method based on the SIMPLE algorithm. They have been verified by an experimental facility using air-water as a simulation pair and a phase Doppler particle analyzer for velocity and droplet size measurement. The numerical simulation of a lithium-cesium high-temperature pair showed that a nearly homogeneous and isothermal expansion of the two phases is possible with small pressure losses and high kinetic efficiencies. In the throat region a careful profiling is necessary to reduce the inertial effects on the liquid velocity field

Feline superficial pyoderma: a retrospective study of 52 cases (2001-2011).

Science.gov (United States)

Yu, Hui W; Vogelnest, Linda J

2012-10-01

Superficial pyoderma is traditionally considered rare in cats but may be more prevalent than previously reported. To better characterize superficial pyoderma in cats. Fifty-two cats from a dermatology referral population over a 10 year period. This study was retrospective. Cases were included if neutrophils and intracellular bacteria were reported from surface cytology of skin lesions. Medical records were reviewed for signalment, historical and clinical data, cytology results, primary skin diagnoses and treatment details. Disease prevalence was 20%, with no breed or sex predispositions. The estimated median age of onset was 2 years, affecting 54% of cats by 3 years and 23% after 9 years. Fewer cases presented during winter (15%) compared with other seasons. Skin lesions were typically multifocal, affecting the face (62%), neck (37%), limbs (33%) and ventral abdomen (29%) most commonly. Crusting (83%), alopecia (67%), ulceration/erosion (54%) and erythema (46%) were common lesion types. Pruritus was reported in 92% of cats. Underlying hypersensitivities (confirmed in 60%; suspected in 19%), and atopic dermatitis specifically (confirmed in 48%), were the most frequent primary dermatoses. Cats were treated with a variety of systemic and/or topical antimicrobials. The overall apparent response was considered good in 61% and poor in 27% of cats. Recurrence was confirmed or suspected in 42% of cats. Feline superficial pyoderma was more prevalent in this study population than previously reported. Young cats with hypersensitivities and older cats were more commonly affected, and a variety of lesion types and distributions occurred. © 2012 The Authors. Veterinary Dermatology © 2012 ESVD and ACVD.

Threshold velocity for environmentally-assisted cracking in low alloy steels

International Nuclear Information System (INIS)

Wire, G.L.; Kandra, J.T.

1997-01-01

Environmentally Assisted Cracking (EAC) in low alloy steels is generally believed to be activated by dissolution of MnS inclusions at the crack tip in high temperature LWR environments. EAC is the increase of fatigue crack growth rate of up to 40 to 100 times the rate in air that occurs in high temperature LWR environments. A steady state theory developed by Combrade, suggested that EAC will initiate only above a critical crack velocity and cease below this same velocity. A range of about twenty in critical crack tip velocities was invoked by Combrade, et al., to describe data available at that time. This range was attributed to exposure of additional sulfides above and below the crack plane. However, direct measurements of exposed sulfide densities on cracked specimens were performed herein and the results rule out significant additional sulfide exposure as a plausible explanation. Alternatively, it is proposed herein that localized EAC starting at large sulfide clusters reduces the calculated threshold velocity from the value predicted for a uniform distribution of sulfides. Calculations are compared with experimental results where the threshold velocity has been measured, and the predicted wide range of threshold values for steels of similar sulfur content but varying sulfide morphology is observed. The threshold velocity decreases with the increasing maximum sulfide particle size, qualitatively consistent with the theory. The calculation provides a basis for a conservative minimum velocity threshold tied directly to the steel sulfur level, in cases where no details of sulfide distribution are known

Linear Motor With Air Slide

Science.gov (United States)

Johnson, Bruce G.; Gerver, Michael J.; Hawkey, Timothy J.; Fenn, Ralph C.

1993-01-01

Improved linear actuator comprises air slide and linear electric motor. Unit exhibits low friction, low backlash, and more nearly even acceleration. Used in machinery in which positions, velocities, and accelerations must be carefully controlled and/or vibrations must be suppressed.

Turbulent structure of thermal plume. Velocity field

International Nuclear Information System (INIS)

Guillou, B.; Brahimi, M.; Doan-kim-son

1986-01-01

An experimental investigation and a numerical study of the dynamics of a turbulent plume rising from a strongly heated source are described. This type of flow is met in thermal effluents (air, vapor) from, e.g., cooling towers of thermal power plants. The mean and fluctuating values of the vertical component of the velocity were determined using a Laser-Doppler anemometer. The measurements allow us to distinguish three regions in the plume-a developing region near the source, an intermediate region, and a self-preserving region. The characteristics of each zone have been determined. In the self-preserving zone, especially, the turbulence level on the axis and the entrainment coefficient are almost twice of the values observed in jets. The numerical model proposed takes into account an important phenomenon, the intermittency, observed in the plume. This model, established with the self-preserving hypothesis, brings out analytical laws. These laws and the predicted velocity profile are in agreement with the experimental evolutions [fr

Planar measurements of velocity and concentration of turbulent mixing in a T-junction

DEFF Research Database (Denmark)

Ingvorsen, Kristian Mark; Meyer, Knud Erik; Nielsen, N. F.

Turbulent mixing of two isothermal air streams in a T-junction of square ducts are investigated. Three dimensional velocity fields and turbulent kinetic energy are measured with stereoscopic Particle Image Velocimetry (PIV). The concentration field is obtained with a planar Mie scattering technique...

CFD model of thermal and velocity conditions in a particular indoor environment

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