This document analyzes the transition from laminar to turbulent flow for 13 patients receiving oxygen treatment. It finds that for 12 out of the 13 patients, the critical radius for the onset of turbulent flow is much smaller when breathing a helium-oxygen mixture (HeOx) compared to regular air. For all patients breathing air, the critical radius is larger than the patient's throat or endotracheal tube radius, indicating turbulent flow, whereas HeOx results in laminar flow for most patients. The document concludes that HeOx is superior to air for treating patients with breathing difficulties as it promotes easier laminar flow.
C:\Documents And Settings\User\Desktop\Lec54MBBS IMS MSU
The circulatory system transports blood throughout the body via arteries, arterioles, capillaries and veins. Blood flow is determined by pressure differences and vascular resistance. It is highest in arteries and lowest in capillaries, where exchange with tissues occurs. Total peripheral resistance and blood pressure regulate blood flow through the entire circulation according to pressure-flow relationships defined by Poiseuille's law.
The Reynolds number is a dimensionless number that quantifies the ratio of inertial to viscous forces within a fluid, and can be used to predict laminar or turbulent flow. It is calculated by taking the product of a fluid's density, velocity, and characteristic linear dimension, divided by the fluid's viscosity. A Reynolds number less than 2300 typically indicates laminar flow, between 2300-4000 is transitional, and greater than 4000 is turbulent flow. The Reynolds number is an important concept in fluid dynamics used to analyze conditions that could lead to turbulent blood flow.
Fluid Mechanics Chapter 3. Integral relations for a control volumeAddisu Dagne Zegeye
Introduction, physical laws of fluid mechanics, the Reynolds transport theorem, Conservation of mass equation, Linear momentum equation, Angular momentum equation, Energy equation, Bernoulli equation
This document discusses fluid flow, including definitions, types of flow, and factors affecting flow. It defines laminar and turbulent flow, and notes laminar flow is smooth while turbulent flow is disorganized. Pressure, radius, length, viscosity, density, and temperature can impact flow. Clinical applications of flow include devices like rotameters and measurements of breathing.
This document discusses the objectives and content of a fluid mechanics and machinery course. It includes:
- The objectives of understanding fluid properties, dimensional analysis, and various types of pumps and turbines.
- An introduction to fluid mechanics, including the basic concepts and importance in engineering applications.
- Details about the first unit which will cover fluid properties, flow characteristics using concepts like the continuity, energy, and momentum equations.
This document discusses uniform, source, and sink flows. It defines uniform flow as flow where velocity and other parameters do not change from point to point over time. Uniform flow can be steady or unsteady. Source flow originates from a central point and spreads outward with decreasing velocity. Sink flow is the opposite, with streamlines directed inward towards a central point and increasing velocity. A doublet combines an equal source and sink placed very close together, with streamlines starting and ending at the same point. The document provides examples and equations related to the velocity profiles of these different flow types.
This document provides an introduction to fluid mechanics. It begins with definitions of mechanics, statics, dynamics, and fluid mechanics. It then discusses different categories of fluid mechanics including fluid statics, fluid kinematics, fluid dynamics, hydrodynamics, hydraulics, gas dynamics, and aerodynamics. The document also defines what a fluid is, discusses the properties of fluids including density, specific weight, specific volume, and specific gravity. It concludes by explaining viscosity, kinematic viscosity, and Newton's law of viscosity.
This document discusses the different types of fluid flows. It describes 6 main types of fluid flows: 1) steady and unsteady, 2) uniform and non-uniform, 3) laminar and turbulent, 4) compressible and incompressible, 5) rotational and irrotational, and 6) one-, two-, and three-dimensional flows. For each type of flow, it provides a brief definition and examples to explain the differences between the types.
C:\Documents And Settings\User\Desktop\Lec54MBBS IMS MSU
The circulatory system transports blood throughout the body via arteries, arterioles, capillaries and veins. Blood flow is determined by pressure differences and vascular resistance. It is highest in arteries and lowest in capillaries, where exchange with tissues occurs. Total peripheral resistance and blood pressure regulate blood flow through the entire circulation according to pressure-flow relationships defined by Poiseuille's law.
The Reynolds number is a dimensionless number that quantifies the ratio of inertial to viscous forces within a fluid, and can be used to predict laminar or turbulent flow. It is calculated by taking the product of a fluid's density, velocity, and characteristic linear dimension, divided by the fluid's viscosity. A Reynolds number less than 2300 typically indicates laminar flow, between 2300-4000 is transitional, and greater than 4000 is turbulent flow. The Reynolds number is an important concept in fluid dynamics used to analyze conditions that could lead to turbulent blood flow.
Fluid Mechanics Chapter 3. Integral relations for a control volumeAddisu Dagne Zegeye
Introduction, physical laws of fluid mechanics, the Reynolds transport theorem, Conservation of mass equation, Linear momentum equation, Angular momentum equation, Energy equation, Bernoulli equation
This document discusses fluid flow, including definitions, types of flow, and factors affecting flow. It defines laminar and turbulent flow, and notes laminar flow is smooth while turbulent flow is disorganized. Pressure, radius, length, viscosity, density, and temperature can impact flow. Clinical applications of flow include devices like rotameters and measurements of breathing.
This document discusses the objectives and content of a fluid mechanics and machinery course. It includes:
- The objectives of understanding fluid properties, dimensional analysis, and various types of pumps and turbines.
- An introduction to fluid mechanics, including the basic concepts and importance in engineering applications.
- Details about the first unit which will cover fluid properties, flow characteristics using concepts like the continuity, energy, and momentum equations.
This document discusses uniform, source, and sink flows. It defines uniform flow as flow where velocity and other parameters do not change from point to point over time. Uniform flow can be steady or unsteady. Source flow originates from a central point and spreads outward with decreasing velocity. Sink flow is the opposite, with streamlines directed inward towards a central point and increasing velocity. A doublet combines an equal source and sink placed very close together, with streamlines starting and ending at the same point. The document provides examples and equations related to the velocity profiles of these different flow types.
This document provides an introduction to fluid mechanics. It begins with definitions of mechanics, statics, dynamics, and fluid mechanics. It then discusses different categories of fluid mechanics including fluid statics, fluid kinematics, fluid dynamics, hydrodynamics, hydraulics, gas dynamics, and aerodynamics. The document also defines what a fluid is, discusses the properties of fluids including density, specific weight, specific volume, and specific gravity. It concludes by explaining viscosity, kinematic viscosity, and Newton's law of viscosity.
This document discusses the different types of fluid flows. It describes 6 main types of fluid flows: 1) steady and unsteady, 2) uniform and non-uniform, 3) laminar and turbulent, 4) compressible and incompressible, 5) rotational and irrotational, and 6) one-, two-, and three-dimensional flows. For each type of flow, it provides a brief definition and examples to explain the differences between the types.
This document provides an overview of fluid kinematics, which is the study of fluid motion without considering forces. It discusses key concepts like streamlines, pathlines, and streaklines. It describes Lagrangian and Eulerian methods for describing fluid motion. It also covers various types of fluid flow such as steady/unsteady, laminar/turbulent, compressible/incompressible, and one/two/three-dimensional flow. Important topics like continuity equation, velocity, acceleration, and stream/velocity potential functions are also summarized. The document is intended to outline the syllabus and learning objectives for a course unit on fluid kinematics.
a presentation about Reynolds Number prepared by a group for the course of soil mechanics and was presented to Dr. Mohamed El-Taher. PS we did not create slide no. 17 and don't know its main source
This document provides an introduction to fluid mechanics and fluid properties. It discusses:
1) Fluid mechanics is the study of fluids at rest and in motion, and is divided into fluid statics and fluid dynamics (kinematics and kinetics).
2) Key fluid properties include density, specific weight, specific volume, viscosity, compressibility, and surface tension. Equations for calculating these properties are presented.
3) Types of fluids include ideal, real, Newtonian, non-Newtonian, and plastic fluids. Types of flow include steady, unsteady, uniform, non-uniform, compressible, and incompressible flow.
Chapter1 fm-introduction to fluid mechanics-convertedSatishkumarP9
This document discusses fluid mechanics and provides definitions and classifications of fluid flows. It defines fluid mechanics as the science dealing with fluids at rest or in motion and their interactions with solids. Fluid flows are classified as internal or external, compressible or incompressible, laminar or turbulent based on factors like whether the fluid is confined or not, the level of density variation, and the orderliness of fluid motion. The document also lists many application areas of fluid mechanics across various engineering and scientific fields.
The document discusses various terms used in fluid flows such as path lines, streak lines, streamlines and stream tubes. It also discusses different types of fluid flows including steady and unsteady, uniform and non-uniform, laminar and turbulent flows. The document then describes a Venturi meter and orifice meter, which are devices used to measure fluid flow rates based on Bernoulli's principle. A Venturi meter consists of a converging inlet, throat and diverging outlet, while an orifice meter uses a thin circular plate with a hole to restrict flow. Both devices are commonly used to measure flows in pipes and channels.
This document provides an overview of boundary layer concepts and laminar and turbulent pipe flow. It defines boundary layer thickness, displacement thickness, and momentum thickness. It describes how boundary layers develop on surfaces and transition from laminar to turbulent. It also discusses Reynolds number effects, momentum integral estimates for flat plates, and examples calculating boundary layer thickness in air and water flow. Finally, it introduces concepts of laminar and turbulent pipe flow.
The document discusses various topics related to fluid mechanics and fluid flow. It defines mechanics, fluid mechanics, and related subcategories like hydrodynamics and aerodynamics. It describes the different states of matter and properties of fluids like density, viscosity, and surface tension. The document also discusses concepts like pressure, buoyancy, and fluid flow characteristics such as laminar vs turbulent flow, compressible vs incompressible flow, and one-dimensional, two-dimensional, and three-dimensional flows.
1. The document discusses key concepts in fluid mechanics including conservation of mass, momentum, and energy as applied to control volumes.
2. These conservation principles are expressed mathematically through equations that equate the rate of change within the control volume to the net rate of transfer into and out of the control volume.
3. Specific examples are given for the conservation of mass including the continuity equation and steady, incompressible flow cases where the equations can be simplified.
Report on Types of fluid flow
fluid dynamics
Introduction
In physics, fluid flow has all kinds of aspects: steady or unsteady, compressible or incompressible, viscous or non-viscous, and rotational or irrotational to name a few. Some of these characteristics reflect properties of the liquid itself, and others focus on how the fluid is moving. Note that fluid flow can get very complex when it becomes turbulent. Physicists haven’t developed any elegant equations to describe turbulence because how turbulence works depends on the individual system whether you have water cascading through a pipe or air streaming out of a jet engine. Usually, you have to resort to computers to handle problems that involve fluid turbulence. Types of fluid flow:
Aerodynamic force
Cavitation
Compressible flow
Couette flow
Free molecular flow
Incompressible flow
THEORETICAL STUDY ON PIPE OF TAPERED THICKNESS WITH AN INTERNAL FLOW TO ESTIM...IAEME Publication
This research study the effect of tapered thickness on the free transverse vibration of clamped – free pipe which have uniform circular cross section conveying water by using Raighly –Ritz method in the two case, the first involves the pipe have a constant wall thickness (t1) at clamped end equal to (1mm & 2mm) while the thickness (t2) at free end changes according to the ratio (t2/t1=0.2, 0.4, 0.6, 0.8, 1). In the second case the thickness at free end (t2) is constant (1mm & 2mm) whereas the thickness at clamped end (t1) changes at ratio (t1/t2=0.2, 0.4, 0.6, 0.8, 1). The pipe has a constant inner radius (Ri) of (1 cm or 2 cm) and different values of length (1m & 2m).
This document discusses key concepts in fluid dynamics, including:
1. Fluid flow, viscosity, and Bernoulli's equation are the main properties of fluid dynamics. Fluid flow is the movement of a fluid and can be steady or turbulent. Viscosity is the resistance of fluid layers sliding past one another.
2. Bernoulli's equation relates pressure, velocity, and elevation in fluid systems. It states that the total mechanical energy (pressure + potential + kinetic energy) remains constant in fluid flow. Higher velocities correspond to lower pressures.
3. Other topics covered include streamlines, continuity equation, rate of flow, factors affecting viscosity, and examples applying Bernoulli's equation. The goal is to analyze pressure and velocity in various
This document outlines preliminary studies on an Oscillatory Flow Reactor in a mini fluidic channel. The objective was to evaluate how Oscillatory flow technology can increase heat transfer coefficients and pressure drop in miniaturized channels. Studies showed that oscillation and pulsation in the reactor enhanced convection currents, increasing heat transfer. Pressure drop was also increased with oscillatory flow.
Hydrodynamics Studies on Oscillatory Flow Technology in MinichannelsKirubanandan Shanmugam
This document summarizes preliminary work investigating oscillatory flow technology in mini-channels. The researchers were able to generate oscillatory flow at 1.17 Hz and 2.93 Hz frequencies using a rotating valve assembly in their experimental system. However, the current valve design had packing issues and the flow signal was noisy, presenting challenges for further characterization. Overall, the work demonstrated the potential of an oscillatory pressure field to induce flow in the low energy dissipation region, but improvements are still needed to avoid leaks and characterize flow at higher frequencies.
This document summarizes different types of fluid flow, including:
- Steady and unsteady flow
- Laminar and turbulent flow
- Compressible and incompressible flow
- One, two, and three dimensional flows
It defines each type of flow and provides examples to explain the differences between steady and unsteady flow, laminar and turbulent flow, and compressible and incompressible flow.
Fluid Mechanics-Shear stress ,Shear stress distribution,Velocity profile,Flow Of Viscous Fluid Through The circular pipe ,Velocity profile for turbulent flow Boundary layer buildup in pipe,Velocity Distributions
The document discusses preliminary studies evaluating oscillatory flow technology (OFT) in miniaturized channels with diameters around 1mm. Theoretical analysis predicts increased Nusselt numbers, a measure of heat transfer, for OFT in minichannels compared to smooth pipes at equivalent energy dissipation. Experimental testing of a newly constructed system will evaluate momentum, heat, and mass transfer performance of OFT in minichannels relative to both smooth pipes and other minifluidic devices. Future work will design mini-fluidic channels optimized for oscillatory flow and test them experimentally.
The document describes a study that investigated the depth-wise profiles of velocity and turbulence parameters in the proximity of a mid-channel bar using experimental and computational fluid dynamics (CFD) modeling methods. Velocity measurements were taken at various depths and locations near the mid-channel bar using an acoustic Doppler velocimeter (ADV). The study found changes in the velocity and turbulence profiles due to interactions between the fluid flow and the mid-channel bar. CFD modeling with the Reynolds stress model was also used to validate the experimental results.
1. The document discusses flow in ducts and pipes, including circular and non-circular cross-sections. It also covers topics like hydraulic diameter, average velocity, laminar and turbulent flow regimes.
2. Entrance effects are explained, including the development of boundary layers and velocity profiles. Equations are given for estimating the hydrodynamic entry length in laminar and turbulent flows.
3. The force balance on a control volume is used to derive equations for the velocity profile in fully developed laminar pipe flow.
4. Head loss and pressure drop correlations are presented, making use of the Darcy-Weisbach friction factor and Colebrook equation.
5. Turbulent flow near walls is analyzed
This document discusses fluid flow, including laminar and turbulent flow, transition between the two, and the effects of turbulence. It also covers topics like pipe flow, the Reynolds number parameter, and pressure drops and head losses in pipes. Some key points made include:
- At moderate Reynolds numbers, smooth laminar flow becomes fluctuating turbulent flow due to transition.
- Turbulence enhances heat and mass transfer compared to laminar flow.
- Fully developed pipe flow can be modeled using logarithmic velocity profiles and relationships between friction factor and Reynolds number.
- Minor losses from fittings add to overall pressure drops beyond just major losses in straight pipe sections.
This document provides an overview of fluid kinematics, which is the study of fluid motion without considering forces. It discusses key concepts like streamlines, pathlines, and streaklines. It describes Lagrangian and Eulerian methods for describing fluid motion. It also covers various types of fluid flow such as steady/unsteady, laminar/turbulent, compressible/incompressible, and one/two/three-dimensional flow. Important topics like continuity equation, velocity, acceleration, and stream/velocity potential functions are also summarized. The document is intended to outline the syllabus and learning objectives for a course unit on fluid kinematics.
a presentation about Reynolds Number prepared by a group for the course of soil mechanics and was presented to Dr. Mohamed El-Taher. PS we did not create slide no. 17 and don't know its main source
This document provides an introduction to fluid mechanics and fluid properties. It discusses:
1) Fluid mechanics is the study of fluids at rest and in motion, and is divided into fluid statics and fluid dynamics (kinematics and kinetics).
2) Key fluid properties include density, specific weight, specific volume, viscosity, compressibility, and surface tension. Equations for calculating these properties are presented.
3) Types of fluids include ideal, real, Newtonian, non-Newtonian, and plastic fluids. Types of flow include steady, unsteady, uniform, non-uniform, compressible, and incompressible flow.
Chapter1 fm-introduction to fluid mechanics-convertedSatishkumarP9
This document discusses fluid mechanics and provides definitions and classifications of fluid flows. It defines fluid mechanics as the science dealing with fluids at rest or in motion and their interactions with solids. Fluid flows are classified as internal or external, compressible or incompressible, laminar or turbulent based on factors like whether the fluid is confined or not, the level of density variation, and the orderliness of fluid motion. The document also lists many application areas of fluid mechanics across various engineering and scientific fields.
The document discusses various terms used in fluid flows such as path lines, streak lines, streamlines and stream tubes. It also discusses different types of fluid flows including steady and unsteady, uniform and non-uniform, laminar and turbulent flows. The document then describes a Venturi meter and orifice meter, which are devices used to measure fluid flow rates based on Bernoulli's principle. A Venturi meter consists of a converging inlet, throat and diverging outlet, while an orifice meter uses a thin circular plate with a hole to restrict flow. Both devices are commonly used to measure flows in pipes and channels.
This document provides an overview of boundary layer concepts and laminar and turbulent pipe flow. It defines boundary layer thickness, displacement thickness, and momentum thickness. It describes how boundary layers develop on surfaces and transition from laminar to turbulent. It also discusses Reynolds number effects, momentum integral estimates for flat plates, and examples calculating boundary layer thickness in air and water flow. Finally, it introduces concepts of laminar and turbulent pipe flow.
The document discusses various topics related to fluid mechanics and fluid flow. It defines mechanics, fluid mechanics, and related subcategories like hydrodynamics and aerodynamics. It describes the different states of matter and properties of fluids like density, viscosity, and surface tension. The document also discusses concepts like pressure, buoyancy, and fluid flow characteristics such as laminar vs turbulent flow, compressible vs incompressible flow, and one-dimensional, two-dimensional, and three-dimensional flows.
1. The document discusses key concepts in fluid mechanics including conservation of mass, momentum, and energy as applied to control volumes.
2. These conservation principles are expressed mathematically through equations that equate the rate of change within the control volume to the net rate of transfer into and out of the control volume.
3. Specific examples are given for the conservation of mass including the continuity equation and steady, incompressible flow cases where the equations can be simplified.
Report on Types of fluid flow
fluid dynamics
Introduction
In physics, fluid flow has all kinds of aspects: steady or unsteady, compressible or incompressible, viscous or non-viscous, and rotational or irrotational to name a few. Some of these characteristics reflect properties of the liquid itself, and others focus on how the fluid is moving. Note that fluid flow can get very complex when it becomes turbulent. Physicists haven’t developed any elegant equations to describe turbulence because how turbulence works depends on the individual system whether you have water cascading through a pipe or air streaming out of a jet engine. Usually, you have to resort to computers to handle problems that involve fluid turbulence. Types of fluid flow:
Aerodynamic force
Cavitation
Compressible flow
Couette flow
Free molecular flow
Incompressible flow
THEORETICAL STUDY ON PIPE OF TAPERED THICKNESS WITH AN INTERNAL FLOW TO ESTIM...IAEME Publication
This research study the effect of tapered thickness on the free transverse vibration of clamped – free pipe which have uniform circular cross section conveying water by using Raighly –Ritz method in the two case, the first involves the pipe have a constant wall thickness (t1) at clamped end equal to (1mm & 2mm) while the thickness (t2) at free end changes according to the ratio (t2/t1=0.2, 0.4, 0.6, 0.8, 1). In the second case the thickness at free end (t2) is constant (1mm & 2mm) whereas the thickness at clamped end (t1) changes at ratio (t1/t2=0.2, 0.4, 0.6, 0.8, 1). The pipe has a constant inner radius (Ri) of (1 cm or 2 cm) and different values of length (1m & 2m).
This document discusses key concepts in fluid dynamics, including:
1. Fluid flow, viscosity, and Bernoulli's equation are the main properties of fluid dynamics. Fluid flow is the movement of a fluid and can be steady or turbulent. Viscosity is the resistance of fluid layers sliding past one another.
2. Bernoulli's equation relates pressure, velocity, and elevation in fluid systems. It states that the total mechanical energy (pressure + potential + kinetic energy) remains constant in fluid flow. Higher velocities correspond to lower pressures.
3. Other topics covered include streamlines, continuity equation, rate of flow, factors affecting viscosity, and examples applying Bernoulli's equation. The goal is to analyze pressure and velocity in various
This document outlines preliminary studies on an Oscillatory Flow Reactor in a mini fluidic channel. The objective was to evaluate how Oscillatory flow technology can increase heat transfer coefficients and pressure drop in miniaturized channels. Studies showed that oscillation and pulsation in the reactor enhanced convection currents, increasing heat transfer. Pressure drop was also increased with oscillatory flow.
Hydrodynamics Studies on Oscillatory Flow Technology in MinichannelsKirubanandan Shanmugam
This document summarizes preliminary work investigating oscillatory flow technology in mini-channels. The researchers were able to generate oscillatory flow at 1.17 Hz and 2.93 Hz frequencies using a rotating valve assembly in their experimental system. However, the current valve design had packing issues and the flow signal was noisy, presenting challenges for further characterization. Overall, the work demonstrated the potential of an oscillatory pressure field to induce flow in the low energy dissipation region, but improvements are still needed to avoid leaks and characterize flow at higher frequencies.
This document summarizes different types of fluid flow, including:
- Steady and unsteady flow
- Laminar and turbulent flow
- Compressible and incompressible flow
- One, two, and three dimensional flows
It defines each type of flow and provides examples to explain the differences between steady and unsteady flow, laminar and turbulent flow, and compressible and incompressible flow.
Fluid Mechanics-Shear stress ,Shear stress distribution,Velocity profile,Flow Of Viscous Fluid Through The circular pipe ,Velocity profile for turbulent flow Boundary layer buildup in pipe,Velocity Distributions
The document discusses preliminary studies evaluating oscillatory flow technology (OFT) in miniaturized channels with diameters around 1mm. Theoretical analysis predicts increased Nusselt numbers, a measure of heat transfer, for OFT in minichannels compared to smooth pipes at equivalent energy dissipation. Experimental testing of a newly constructed system will evaluate momentum, heat, and mass transfer performance of OFT in minichannels relative to both smooth pipes and other minifluidic devices. Future work will design mini-fluidic channels optimized for oscillatory flow and test them experimentally.
The document describes a study that investigated the depth-wise profiles of velocity and turbulence parameters in the proximity of a mid-channel bar using experimental and computational fluid dynamics (CFD) modeling methods. Velocity measurements were taken at various depths and locations near the mid-channel bar using an acoustic Doppler velocimeter (ADV). The study found changes in the velocity and turbulence profiles due to interactions between the fluid flow and the mid-channel bar. CFD modeling with the Reynolds stress model was also used to validate the experimental results.
1. The document discusses flow in ducts and pipes, including circular and non-circular cross-sections. It also covers topics like hydraulic diameter, average velocity, laminar and turbulent flow regimes.
2. Entrance effects are explained, including the development of boundary layers and velocity profiles. Equations are given for estimating the hydrodynamic entry length in laminar and turbulent flows.
3. The force balance on a control volume is used to derive equations for the velocity profile in fully developed laminar pipe flow.
4. Head loss and pressure drop correlations are presented, making use of the Darcy-Weisbach friction factor and Colebrook equation.
5. Turbulent flow near walls is analyzed
This document discusses fluid flow, including laminar and turbulent flow, transition between the two, and the effects of turbulence. It also covers topics like pipe flow, the Reynolds number parameter, and pressure drops and head losses in pipes. Some key points made include:
- At moderate Reynolds numbers, smooth laminar flow becomes fluctuating turbulent flow due to transition.
- Turbulence enhances heat and mass transfer compared to laminar flow.
- Fully developed pipe flow can be modeled using logarithmic velocity profiles and relationships between friction factor and Reynolds number.
- Minor losses from fittings add to overall pressure drops beyond just major losses in straight pipe sections.
This document discusses the basic principles of arterial hemodynamics and its clinical application in arterial disease. It covers topics such as fluid pressure and energy, Bernoulli's principle, fluid energy losses due to viscosity and inertia, vascular resistance, blood flow patterns, the effects of stenosis, collateral circulation, and the impact of exercise therapy, vasodilators, sympathectomy, vascular steal, and gravity on arterial hemodynamics and blood flow.
This document discusses compressible flow and its applications in chemical engineering. It begins by defining compressible flow as fluid flow with significant changes in density, usually when the Mach number is greater than 0.3. It then discusses how to distinguish compressible fluids using the Mach number and provides some historical examples. The effects of compressibility, such as choked flow, shock waves, and changes in density with pressure changes are described. Finally, some applications of compressible flow in chemical engineering are mentioned, such as high-speed gas flow in pipes and nozzles and compressible gas flow in chemical processing industries.
The document discusses various methods for measuring cardiac output, including Fick's method. It explains the concepts of hemodynamics using Ohm's law and Poiseuille's law to relate factors like blood pressure, flow, resistance, vessel diameter and viscosity. The document also describes types of blood flow such as laminar and turbulent flow, and how flow is affected by conditions like stenosis, anemia and atherosclerosis. Measurement methods discussed include direct methods using electromagnetic and Doppler flow meters, and indirect methods like Fick's principle and indicator dilution techniques.
This document introduces fluid dynamics and its biological and medical applications. It discusses key concepts such as:
- Flow rate and its relationship to velocity and how flow rate is calculated.
- Bernoulli's equation, which relates pressure and velocity in fluids and describes how pressure drops where velocity increases due to a gain in kinetic energy.
- Applications of Bernoulli's principle like how shower curtains bulge inward due to lower pressure caused by high velocity water, and how passing vehicles can be pushed together for the same reason.
- Other topics covered include the equation of continuity, laminar and turbulent flow, viscosity, and diffusion. Real-world examples involve calculating blood flow and vessel speeds.
This document provides information about fluid flow through pipes, including definitions and equations. It defines types of fluid flow such as steady/unsteady, uniform/non-uniform, laminar/turbulent. It also defines compressible/incompressible flow and rotational/irrotational flow. Bernoulli's equation and its assumptions are described. Darcy-Weisbach and Hagen-Poiseuille equations for head loss due to friction are given. Reynolds number range for laminar and turbulent flow is provided. Shear stress, velocity distribution, and average velocity equations are listed. Factors affecting frictional head loss are also mentioned.
Rev. August 2014 ME495 - Pipe Flow Characteristics… Page .docxjoyjonna282
Rev. August 2014 ME495 - Pipe Flow Characteristics… Page 2
2
ME495—Thermo Fluids Laboratory
~~~~~~~~~~~~~~
PIPE FLOW CHARACTERISTICS
AND PRESSURE TRANSDUCER
CALIBRATION
~~~~~~~~~~~~~~
PREPARED BY: GROUP LEADER’S NAME
LAB PARTNERS: NAME
NAME
NAME
TIME/DATE OF EXPERIMENT: TIME , DATE
~~~~~~~~~~~~~~
OBJECTIVE— The objectives of this experiment are
to: a) observe the characteristics of flow in a pipe,
b) evaluate the flow rate in a pipe using velocity
and pressure difference measurements, and c)
perform the calibration of a pressure transducer.
Upon completing this experiment you should have
learned (i) how to measure the flow rate and average
velocity in a pipe using a Pitot tube and/or a resistance
flow meter, and (ii) how to classify the general
characteristics of a pipe flow.
Nomenclature
a = speed of sound, m/s
A = area, m
2
C = discharge coefficient, dimensionless
d = pipe diameter, m
d0 = orifice diameter, m
E = velocity approach factor, dimensionless
f = Darcy friction factor, dimensionless
K0 = flow coefficient, dimensionless
k = ratio of specific heats (cp/cv), dimensionless
L = length of pipe, m
M = Mach number, dimensionless
p = pressure, Pa
p0 = stagnation pressure, Pa
p1, p2 = pressure at two axial locations along a
pipe, Pa
Q = volumetric flow rate, m
3
/s
R = specific gas constant, J·kg/K
Re = Reynolds number, dimensionless
T = temperature, K
V = local velocity, m/s
V = average velocity, m/s
Y = adiabatic expansion factor, dimensionless
= ratio of orifice diameter to pipe diameter,
dimensionless
p = pressure drop across an orifice meter, Pa
= dynamic viscosity, Pa·s
= air density, kg/m3
INTRODUCTION— The flow of a fluid (liquid or
gas) through pipes or ducts is a common part of many
engineering systems. Household applications include
the flow of water in copper pipes, the flow of natural
gas in steel pipes, and the flow of heated air through
metal ducts of rectangular cross-section in a forced-air
furnace system. Industrial applications range from the
flow of liquid plastics in a manufacturing plant, to the
flow of yogurt in a food-processing plant. Because the
purpose of a piping system is to transport a desired
quantity of fluid, it is important to understand the
various methods of measuring the flow rate.
In order to work with a fluid system, and certainly to
design a fluid system that will deliver a prescribed
flow, it is necessary to understand certain fundamental
aspects of the fluid flow. For this, one should be able
to answer questions like: Are compressibility effects
important? Is the flow laminar or turbulent? Is the
viscosity of the fluid important or not? Is the flow
steady or varying with time? What are the primary
forces of importance? For internal ...
The blood circulates in a closed system of branching conduits. Haemodynamics refers to the studies of blood flow and related forces in moving the blood through the circulatory system. It
discusses the physical principles of blood flow t through the blood vessels with reference to the interrelationships among pressure, flow, and resistance.
Lecture 6_Basic Equations of Fluid Mechanics.pptx.pdfTohfatulJinan1
This document discusses basic equations of fluid mechanics used in a biofluid mechanics and heat transfer course. It covers the Bernoulli equation and its application to problems involving blood flow in the aorta and capillaries. It also discusses venturi meters, which use the Bernoulli principle to measure fluid flow rates. Venturi meters have a constricted section that causes velocity and pressure to change in a way that can be used to calculate flow rates. The document provides equations for calculating theoretical discharge through a venturi meter and defines related terms like cross-sectional area and velocity at different pipe sections.
Pipe flow involves fluid completely filling a pipe, while open channel flow has a free surface. In pipe flow, pressure varies along the pipe but remains constant at the free surface in open channels. The main driving force is gravity in open channels and pressure gradient in pipes. Flow properties like cross-sectional area and velocity profile differ between the two flow types.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and TechnologyIJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Comparison of flow analysis of a sudden and gradual change of pipe diameter u...eSAT Journals
Abstract This paper describes an analytical approach to describe the areas where Pipes (used for flow of fluids) are mostly susceptible to damage and tries to visualize the flow behaviour in various geometric conditions of a pipe. Fluent software was used to plot the characteristics of the flow and gambit software was used to design the 2D model. Two phase Computational fluid dynamics calculations, using K-epsilon model were employed. This simulation gives the values of pressure and velocity contours at various sections of the pipe in which water as a media. A comparison was made with the sudden and gradual change of pipe diameter (i.e., expansion and contraction of the pipe). The numerical results were validated against experimental data from the literature and were found to be in good agreement. Index Terms: gambit, fluent software.
Dr. Charbel and colleagues developed a new Doppler ultrasonic probe to measure blood flow velocities in intracranial vessels during cerebrovascular bypass surgeries. They measured "cut-flow" in the superficial temporal artery branch before bypass anastomosis and compared it to postoperative blood flow values measured with MRI. They found the new probe provided a quicker, easier, and less expensive way to evaluate bypass patency compared to traditional angiography or imaging methods. The study aimed to evaluate the effectiveness of bypass procedures by measuring pre-operative cut-flow and comparing it to postoperative graft flow measurements.
The document discusses characteristics of flow in hoses and pipelines, including:
- The velocity of water flow is determined by gravity and can be calculated using formulas comparing time, velocity, and distance fallen.
- Flow rate in pipes/hoses (Q) is calculated using the formula Q = v x A, where v is velocity and A is cross-sectional area.
- Friction causes loss of pressure in water flow through resistance. The loss of pressure due to friction (Pf) increases with length, velocity, and flow rate while decreasing with diameter. Formulas are provided to calculate Pf.
This document discusses turbulent fluid flow. It defines turbulence as an irregular flow with random variations in time and space that can be expressed statistically. Turbulence occurs above a critical Reynolds number when the kinetic energy of the flow is enough to sustain random fluctuations against viscous damping. Characteristics of turbulent flow include fluctuating velocities and pressures, and more uniform velocity distributions compared to laminar flow. Turbulence can be generated by solid walls or shear between layers, and can be categorized as homogeneous, isotropic, or anisotropic. Transition from laminar to turbulent flow is also discussed.
The Effect of Capilliary Number on Leading Edge Cavitation Cell Size, THESIS ...Dylan Henness
The document summarizes an experimental study that analyzed the effect of Capillary number on leading edge cavitation cell size for a NACA 16-029 hydrofoil profile. The experiment varied both cavitation number from 0.25 to 0.52 and Reynolds number from 3.5x106 to 7.0x106. High-speed imaging and still images were captured of the leading edge cavitation cells at different flow conditions to analyze cell size variations with changing Capillary number. The results will provide insights into global cavitation physics including cavity growth and collapse processes.
This document discusses compressible flow through nozzles. It introduces concepts like stagnation properties, Mach number, and speed of sound. It then derives relationships for isentropic flow of ideal gases through converging and converging-diverging nozzles. The effects of area changes and back pressure on properties like pressure, temperature, density and mass flow rate are examined for both subsonic and supersonic flow regimes. Nozzle design considerations like shapes needed to achieve desired exit velocities are also covered.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Effect of free surface and froude number on the protection length and turbule...eSAT Journals
Abstract An experimental study was carried out to investigate the effect of free surface, Froude and Reynolds numbers on the protection length and turbulence through compound transitions using Laser Doppler, in a rectangular channel. Measurements of turbulence are carried out along the compound transition, at different contraction ratios, at different bed slopes. Vertical transition in the bed were also changed. From the results, the protection length increases with the increase of the incoming Froude number, and increases with the increase of the relative height, while it increases with the increase of the contraction ratio. The steep slope has a major effect on the protection length. Free surface has a unique role in governing the turbulence in open channel flows. Within and downstream of the transition, the turbulence occurs primarily in the wall region. Within the transition, flow tends towards the critical state (Fr approaches close to 1) with a rise in the turbulence intensities in the free surface and the wall region which may be attributed to the flow tending towards critical state. At small values of Froude number Fr ≤ 0.22, the effect of Froude number on turbulence intensities and the free surface waves negligible. Keywords: Turbulence intensities- Laser Doppler-Protection length-Free surface-Relative height-Contraction ratio-Bottom slope-Froude number
Similar to On the Analysis of the Laminar to Turbulent Flow Patterns in the Treatment of a Patient Receiving Oxygen (20)
The Use of Java Swing’s Components to Develop a WidgetWaqas Tariq
Widget is a kind of application provides a single service such as a map, news feed, simple clock, battery-life indicators, etc. This kind of interactive software object has been developed to facilitate user interface (UI) design. A user interface (UI) function may be implemented using different widgets with the same function. In this article, we present the widget as a platform that is generally used in various applications, such as in desktop, web browser, and mobile phone. We also describe a visual menu of Java Swing’s components that will be used to establish widget. It will assume that we have successfully compiled and run a program that uses Swing components.
3D Human Hand Posture Reconstruction Using a Single 2D ImageWaqas Tariq
Passive sensing of the 3D geometric posture of the human hand has been studied extensively over the past decade. However, these research efforts have been hampered by the computational complexity caused by inverse kinematics and 3D reconstruction. In this paper, our objective focuses on 3D hand posture estimation based on a single 2D image with aim of robotic applications. We introduce the human hand model with 27 degrees of freedom (DOFs) and analyze some of its constraints to reduce the DOFs without any significant degradation of performance. A novel algorithm to estimate the 3D hand posture from eight 2D projected feature points is proposed. Experimental results using real images confirm that our algorithm gives good estimates of the 3D hand pose. Keywords: 3D hand posture estimation; Model-based approach; Gesture recognition; human- computer interface; machine vision.
Camera as Mouse and Keyboard for Handicap Person with Troubleshooting Ability...Waqas Tariq
Camera mouse has been widely used for handicap person to interact with computer. The utmost important of the use of camera mouse is must be able to replace all roles of typical mouse and keyboard. It must be able to provide all mouse click events and keyboard functions (include all shortcut keys) when it is used by handicap person. Also, the use of camera mouse must allow users troubleshooting by themselves. Moreover, it must be able to eliminate neck fatigue effect when it is used during long period. In this paper, we propose camera mouse system with timer as left click event and blinking as right click event. Also, we modify original screen keyboard layout by add two additional buttons (button “drag/ drop” is used to do drag and drop of mouse events and another button is used to call task manager (for troubleshooting)) and change behavior of CTRL, ALT, SHIFT, and CAPS LOCK keys in order to provide shortcut keys of keyboard. Also, we develop recovery method which allows users go from camera and then come back again in order to eliminate neck fatigue effect. The experiments which involve several users have been done in our laboratory. The results show that the use of our camera mouse able to allow users do typing, left and right click events, drag and drop events, and troubleshooting without hand. By implement this system, handicap person can use computer more comfortable and reduce the dryness of eyes.
A Proposed Web Accessibility Framework for the Arab DisabledWaqas Tariq
The Web is providing unprecedented access to information and interaction for people with disabilities. This paper presents a Web accessibility framework which offers the ease of the Web accessing for the disabled Arab users and facilitates their lifelong learning as well. The proposed framework system provides the disabled Arab user with an easy means of access using their mother language so they don’t have to overcome the barrier of learning the target-spoken language. This framework is based on analyzing the web page meta-language, extracting its content and reformulating it in a suitable format for the disabled users. The basic objective of this framework is supporting the equal rights of the Arab disabled people for their access to the education and training with non disabled people. Key Words : Arabic Moon code, Arabic Sign Language, Deaf, Deaf-blind, E-learning Interactivity, Moon code, Web accessibility , Web framework , Web System, WWW.
Real Time Blinking Detection Based on Gabor FilterWaqas Tariq
The document proposes a new method for real-time blinking detection based on Gabor filters. It begins by reviewing existing methods and their limitations in dealing with noise, variations in eye shape, and blinking speed. The proposed method uses a Gabor filter to extract the top and bottom arcs of the eye from an image. It then measures the distance between these arcs and compares it to a threshold: a distance below the threshold indicates a closed eye, while a distance above indicates an open eye. The document claims this Gabor filter-based approach is robust to noise, variations in eye shape and blinking speed. It presents experimental results showing the method can accurately detect blinking across different users.
Computer Input with Human Eyes-Only Using Two Purkinje Images Which Works in ...Waqas Tariq
A method for computer input with human eyes-only using two Purkinje images which works in a real time basis without calibration is proposed. Experimental results shows that cornea curvature can be estimated by using two light sources derived Purkinje images so that no calibration for reducing person-to-person difference of cornea curvature. It is found that the proposed system allows usersf movements of 30 degrees in roll direction and 15 degrees in pitch direction utilizing detected face attitude which is derived from the face plane consisting three feature points on the face, two eyes and nose or mouth. Also it is found that the proposed system does work in a real time basis.
Toward a More Robust Usability concept with Perceived Enjoyment in the contex...Waqas Tariq
Mobile multimedia service is relatively new but has quickly dominated people¡¯s lives, especially among young people. To explain this popularity, this study applies and modifies the Technology Acceptance Model (TAM) to propose a research model and conduct an empirical study. The goal of study is to examine the role of Perceived Enjoyment (PE) and what determinants can contribute to PE in the context of using mobile multimedia service. The result indicates that PE is influencing on Perceived Usefulness (PU) and Perceived Ease of Use (PEOU) and directly Behavior Intention (BI). Aesthetics and flow are key determinants to explain Perceived Enjoyment (PE) in mobile multimedia usage.
Collaborative Learning of Organisational KnolwedgeWaqas Tariq
This paper presents recent research into methods used in Australian Indigenous Knowledge sharing and looks at how these can support the creation of suitable collaborative envi- ronments for timely organisational learning. The protocols and practices as used today and in the past by Indigenous communities are presented and discussed in relation to their relevance to a personalised system of knowledge sharing in modern organisational cultures. This research focuses on user models, knowledge acquisition and integration of data for constructivist learning in a networked repository of or- ganisational knowledge. The data collected in the repository is searched to provide collections of up-to-date and relevant material for training in a work environment. The aim is to improve knowledge collection and sharing in a team envi- ronment. This knowledge can then be collated into a story or workflow that represents the present knowledge in the organisation.
Our research aims to propose a global approach for specification, design and verification of context awareness Human Computer Interface (HCI). This is a Model Based Design approach (MBD). This methodology describes the ubiquitous environment by ontologies. OWL is the standard used for this purpose. The specification and modeling of Human-Computer Interaction are based on Petri nets (PN). This raises the question of representation of Petri nets with XML. We use for this purpose, the standard of modeling PNML. In this paper, we propose an extension of this standard for specification, generation and verification of HCI. This extension is a methodological approach for the construction of PNML with Petri nets. The design principle uses the concept of composition of elementary structures of Petri nets as PNML Modular. The objective is to obtain a valid interface through verification of properties of elementary Petri nets represented with PNML.
Development of Sign Signal Translation System Based on Altera’s FPGA DE2 BoardWaqas Tariq
The main aim of this paper is to build a system that is capable of detecting and recognizing the hand gesture in an image captured by using a camera. The system is built based on Altera’s FPGA DE2 board, which contains a Nios II soft core processor. Image processing techniques and a simple but effective algorithm are implemented to achieve this purpose. Image processing techniques are used to smooth the image in order to ease the subsequent processes in translating the hand sign signal. The algorithm is built for translating the numerical hand sign signal and the result are displayed on the seven segment display. Altera’s Quartus II, SOPC Builder and Nios II EDS software are used to construct the system. By using SOPC Builder, the related components on the DE2 board can be interconnected easily and orderly compared to traditional method that requires lengthy source code and time consuming. Quartus II is used to compile and download the design to the DE2 board. Then, under Nios II EDS, C programming language is used to code the hand sign translation algorithm. Being able to recognize the hand sign signal from images can helps human in controlling a robot and other applications which require only a simple set of instructions provided a CMOS sensor is included in the system.
An overview on Advanced Research Works on Brain-Computer InterfaceWaqas Tariq
A brain–computer interface (BCI) is a proficient result in the research field of human- computer synergy, where direct articulation between brain and an external device occurs resulting in augmenting, assisting and repairing human cognitive. Advanced works like generating brain-computer interface switch technologies for intermittent (or asynchronous) control in natural environments or developing brain-computer interface by Fuzzy logic Systems or by implementing wavelet theory to drive its efficacies are still going on and some useful results has also been found out. The requirements to develop this brain machine interface is also growing day by day i.e. like neuropsychological rehabilitation, emotion control, etc. An overview on the control theory and some advanced works on the field of brain machine interface are shown in this paper.
Exploring the Relationship Between Mobile Phone and Senior Citizens: A Malays...Waqas Tariq
There is growing ageing phenomena with the rise of ageing population throughout the world. According to the World Health Organization (2002), the growing ageing population indicates 694 million, or 223% is expected for people aged 60 and over, since 1970 and 2025.The growth is especially significant in some advanced countries such as North America, Japan, Italy, Germany, United Kingdom and so forth. This growing older adult population has significantly impact the social-culture, lifestyle, healthcare system, economy, infrastructure and government policy of a nation. However, there are limited research studies on the perception and usage of a mobile phone and its service for senior citizens in a developing nation like Malaysia. This paper explores the relationship between mobile phones and senior citizens in Malaysia from the perspective of a developing country. We conducted an exploratory study using contextual interviews with 5 senior citizens of how they perceive their mobile phones. This paper reveals 4 interesting themes from this preliminary study, in addition to the findings of the desirable mobile requirements for local senior citizens with respect of health, safety and communication purposes. The findings of this study bring interesting insight to local telecommunication industries as a whole, and will also serve as groundwork for more in-depth study in the future.
Principles of Good Screen Design in WebsitesWaqas Tariq
Visual techniques for proper arrangement of the elements on the user screen have helped the designers to make the screen look good and attractive. Several visual techniques emphasize the arrangement and ordering of the screen elements based on particular criteria for best appearance of the screen. This paper investigates few significant visual techniques in various web user interfaces and showcases the results for better understanding and their presence.
This document discusses the progress of virtual teams in Albania. It provides context on virtual teams and how they differ from traditional teams in their reliance on technology for communication across distances. The document then examines the use of virtual teams in Albania, noting the growing infrastructure and technology usage that enables virtual collaboration. It highlights some virtual team examples in Albanian government and academic projects.
Cognitive Approach Towards the Maintenance of Web-Sites Through Quality Evalu...Waqas Tariq
It is a well established fact that the Web-Applications require frequent maintenance because of cutting– edge business competitions. The authors have worked on quality evaluation of web-site of Indian ecommerce domain. As a result of that work they have made a quality-wise ranking of these sites. According to their work and also the survey done by various other groups Futurebazaar web-site is considered to be one of the best Indian e-shopping sites. In this research paper the authors are assessing the maintenance of the same site by incorporating the problems incurred during this evaluation. This exercise gives a real world maintainability problem of web-sites. This work will give a clear picture of all the quality metrics which are directly or indirectly related with the maintainability of the web-site.
USEFul: A Framework to Mainstream Web Site Usability through Automated Evalua...Waqas Tariq
A paradox has been observed whereby web site usability is proven to be an essential element in a web site, yet at the same time there exist an abundance of web pages with poor usability. This discrepancy is the result of limitations that are currently preventing web developers in the commercial sector from producing usable web sites. In this paper we propose a framework whose objective is to alleviate this problem by automating certain aspects of the usability evaluation process. Mainstreaming comes as a result of automation, therefore enabling a non-expert in the field of usability to conduct the evaluation. This results in reducing the costs associated with such evaluation. Additionally, the framework allows the flexibility of adding, modifying or deleting guidelines without altering the code that references them since the guidelines and the code are two separate components. A comparison of the evaluation results carried out using the framework against published evaluations of web sites carried out by web site usability professionals reveals that the framework is able to automatically identify the majority of usability violations. Due to the consistency with which it evaluates, it identified additional guideline-related violations that were not identified by the human evaluators.
Robot Arm Utilized Having Meal Support System Based on Computer Input by Huma...Waqas Tariq
A robot arm utilized having meal support system based on computer input by human eyes only is proposed. The proposed system is developed for handicap/disabled persons as well as elderly persons and tested with able persons with several shapes and size of eyes under a variety of illumination conditions. The test results with normal persons show the proposed system does work well for selection of the desired foods and for retrieve the foods as appropriate as usersf requirements. It is found that the proposed system is 21% much faster than the manually controlled robotics.
Dynamic Construction of Telugu Speech Corpus for Voice Enabled Text EditorWaqas Tariq
In recent decades speech interactive systems have gained increasing importance. Performance of an ASR system mainly depends on the availability of large corpus of speech. The conventional method of building a large vocabulary speech recognizer for any language uses a top-down approach to speech. This approach requires large speech corpus with sentence or phoneme level transcription of the speech utterances. The transcriptions must also include different speech order so that the recognizer can build models for all the sounds present. But, for Telugu language, because of its complex nature, a very large, well annotated speech database is very difficult to build. It is very difficult, if not impossible, to cover all the words of any Indian language, where each word may have thousands and millions of word forms. A significant part of grammar that is handled by syntax in English (and other similar languages) is handled within morphology in Telugu. Phrases including several words (that is, tokens) in English would be mapped on to a single word in Telugu.Telugu language is phonetic in nature in addition to rich in morphology. That is why the speech technology developed for English cannot be applied to Telugu language. This paper highlights the work carried out in an attempt to build a voice enabled text editor with capability of automatic term suggestion. Main claim of the paper is the recognition enhancement process developed by us for suitability of highly inflecting, rich morphological languages. This method results in increased speech recognition accuracy with very much reduction in corpus size. It also adapts Telugu words to the database dynamically, resulting in growth of the corpus.
An Improved Approach for Word Ambiguity RemovalWaqas Tariq
Word ambiguity removal is a task of removing ambiguity from a word, i.e. correct sense of word is identified from ambiguous sentences. This paper describes a model that uses Part of Speech tagger and three categories for word sense disambiguation (WSD). Human Computer Interaction is very needful to improve interactions between users and computers. For this, the Supervised and Unsupervised methods are combined. The WSD algorithm is used to find the efficient and accurate sense of a word based on domain information. The accuracy of this work is evaluated with the aim of finding best suitable domain of word. Keywords: Human Computer Interaction, Supervised Training, Unsupervised Learning, Word Ambiguity, Word sense disambiguation
Parameters Optimization for Improving ASR Performance in Adverse Real World N...Waqas Tariq
From the existing research it has been observed that many techniques and methodologies are available for performing every step of Automatic Speech Recognition (ASR) system, but the performance (Minimization of Word Error Recognition-WER and Maximization of Word Accuracy Rate- WAR) of the methodology is not dependent on the only technique applied in that method. The research work indicates that, performance mainly depends on the category of the noise, the level of the noise and the variable size of the window, frame, frame overlap etc is considered in the existing methods. The main aim of the work presented in this paper is to use variable size of parameters like window size, frame size and frame overlap percentage to observe the performance of algorithms for various categories of noise with different levels and also train the system for all size of parameters and category of real world noisy environment to improve the performance of the speech recognition system. This paper presents the results of Signal-to-Noise Ratio (SNR) and Accuracy test by applying variable size of parameters. It is observed that, it is really very hard to evaluate test results and decide parameter size for ASR performance improvement for its resultant optimization. Hence, this study further suggests the feasible and optimum parameter size using Fuzzy Inference System (FIS) for enhancing resultant accuracy in adverse real world noisy environmental conditions. This work will be helpful to give discriminative training of ubiquitous ASR system for better Human Computer Interaction (HCI). Keywords: ASR Performance, ASR Parameters Optimization, Multi-Environmental Training, Fuzzy Inference System for ASR, ubiquitous ASR system, Human Computer Interaction (HCI)
A Visual Guide to 1 Samuel | A Tale of Two HeartsSteve Thomason
These slides walk through the story of 1 Samuel. Samuel is the last judge of Israel. The people reject God and want a king. Saul is anointed as the first king, but he is not a good king. David, the shepherd boy is anointed and Saul is envious of him. David shows honor while Saul continues to self destruct.
How to Setup Warehouse & Location in Odoo 17 InventoryCeline George
In this slide, we'll explore how to set up warehouses and locations in Odoo 17 Inventory. This will help us manage our stock effectively, track inventory levels, and streamline warehouse operations.
Chapter wise All Notes of First year Basic Civil Engineering.pptxDenish Jangid
Chapter wise All Notes of First year Basic Civil Engineering
Syllabus
Chapter-1
Introduction to objective, scope and outcome the subject
Chapter 2
Introduction: Scope and Specialization of Civil Engineering, Role of civil Engineer in Society, Impact of infrastructural development on economy of country.
Chapter 3
Surveying: Object Principles & Types of Surveying; Site Plans, Plans & Maps; Scales & Unit of different Measurements.
Linear Measurements: Instruments used. Linear Measurement by Tape, Ranging out Survey Lines and overcoming Obstructions; Measurements on sloping ground; Tape corrections, conventional symbols. Angular Measurements: Instruments used; Introduction to Compass Surveying, Bearings and Longitude & Latitude of a Line, Introduction to total station.
Levelling: Instrument used Object of levelling, Methods of levelling in brief, and Contour maps.
Chapter 4
Buildings: Selection of site for Buildings, Layout of Building Plan, Types of buildings, Plinth area, carpet area, floor space index, Introduction to building byelaws, concept of sun light & ventilation. Components of Buildings & their functions, Basic concept of R.C.C., Introduction to types of foundation
Chapter 5
Transportation: Introduction to Transportation Engineering; Traffic and Road Safety: Types and Characteristics of Various Modes of Transportation; Various Road Traffic Signs, Causes of Accidents and Road Safety Measures.
Chapter 6
Environmental Engineering: Environmental Pollution, Environmental Acts and Regulations, Functional Concepts of Ecology, Basics of Species, Biodiversity, Ecosystem, Hydrological Cycle; Chemical Cycles: Carbon, Nitrogen & Phosphorus; Energy Flow in Ecosystems.
Water Pollution: Water Quality standards, Introduction to Treatment & Disposal of Waste Water. Reuse and Saving of Water, Rain Water Harvesting. Solid Waste Management: Classification of Solid Waste, Collection, Transportation and Disposal of Solid. Recycling of Solid Waste: Energy Recovery, Sanitary Landfill, On-Site Sanitation. Air & Noise Pollution: Primary and Secondary air pollutants, Harmful effects of Air Pollution, Control of Air Pollution. . Noise Pollution Harmful Effects of noise pollution, control of noise pollution, Global warming & Climate Change, Ozone depletion, Greenhouse effect
Text Books:
1. Palancharmy, Basic Civil Engineering, McGraw Hill publishers.
2. Satheesh Gopi, Basic Civil Engineering, Pearson Publishers.
3. Ketki Rangwala Dalal, Essentials of Civil Engineering, Charotar Publishing House.
4. BCP, Surveying volume 1
This presentation was provided by Rebecca Benner, Ph.D., of the American Society of Anesthesiologists, for the second session of NISO's 2024 Training Series "DEIA in the Scholarly Landscape." Session Two: 'Expanding Pathways to Publishing Careers,' was held June 13, 2024.
Philippine Edukasyong Pantahanan at Pangkabuhayan (EPP) CurriculumMJDuyan
(𝐓𝐋𝐄 𝟏𝟎𝟎) (𝐋𝐞𝐬𝐬𝐨𝐧 𝟏)-𝐏𝐫𝐞𝐥𝐢𝐦𝐬
𝐃𝐢𝐬𝐜𝐮𝐬𝐬 𝐭𝐡𝐞 𝐄𝐏𝐏 𝐂𝐮𝐫𝐫𝐢𝐜𝐮𝐥𝐮𝐦 𝐢𝐧 𝐭𝐡𝐞 𝐏𝐡𝐢𝐥𝐢𝐩𝐩𝐢𝐧𝐞𝐬:
- Understand the goals and objectives of the Edukasyong Pantahanan at Pangkabuhayan (EPP) curriculum, recognizing its importance in fostering practical life skills and values among students. Students will also be able to identify the key components and subjects covered, such as agriculture, home economics, industrial arts, and information and communication technology.
𝐄𝐱𝐩𝐥𝐚𝐢𝐧 𝐭𝐡𝐞 𝐍𝐚𝐭𝐮𝐫𝐞 𝐚𝐧𝐝 𝐒𝐜𝐨𝐩𝐞 𝐨𝐟 𝐚𝐧 𝐄𝐧𝐭𝐫𝐞𝐩𝐫𝐞𝐧𝐞𝐮𝐫:
-Define entrepreneurship, distinguishing it from general business activities by emphasizing its focus on innovation, risk-taking, and value creation. Students will describe the characteristics and traits of successful entrepreneurs, including their roles and responsibilities, and discuss the broader economic and social impacts of entrepreneurial activities on both local and global scales.
On the Analysis of the Laminar to Turbulent Flow Patterns in the Treatment of a Patient Receiving Oxygen
1. Navarun Gupta, Lawrence Hmurcik, Manan Joshi & Bhushan Dharmadhikari
International Journal of Applied Sciences (IJAS), Volume (1): Issue (2) 23
On the Analysis of the Laminar to Turbulent Flow Patterns in the
Treatment of a Patient Receiving Oxygen
Navarun Gupta navarung@bridgeport.edu
Department of Electrical Engineering
University of Bridgeport
Bridgeport CT USA 06604
Lawrence Hmurcik hmurcik@bridgeport.edu
Department of Electrical Engineering
University of Bridgeport
Bridgeport CT USA 06604
Manan Joshi mjoshi@bridgeport.edu
Department of Electrical Engineering
University of Bridgeport
Bridgeport CT USA 06604
Bhushan Dharmadhikari bdharmad@bridgeport.edu
Department of Electrical Engineering
University of Bridgeport
Bridgeport CT USA 06604
Abstract
For a fluid, the transition from laminar to turbulent flow is a function of the fluid’s speed,
direction, applied pressure, pipe length, pipe radius, fluid viscosity, and fluid density. For
human breathing, all of these parameters are generally beyond control, except for the
fluid's density and viscosity. If the human has trouble breathing, laminar flow is preferred
since the person does less work for each breath. In our analysis, the pipe is the airway
(or breathing tube) from lips to bifurcation; the throat/pipe radius is known or can be
determined; the differential pressure is the excess pressure above or below
atmospheric pressure; fluid flow rate is the person’s tidal lung volume divided by the
breathing rate. We analyze 13 widely different humans (with differing values for throat
length, radius, etc.) to see the effect of breathing two different fluids: air (20% oxygen,
80% nitrogen) and HeOx (20% oxygen, 80% helium). The onset of turbulent flow occurs
for the critical radius, and this is calculated for each patient. For 12 patients, the critical
radius is much smaller than the throat/tube radius, if HeOx is used--the flow is laminar.
For all patients breathing air, the critical radius is larger than the throat/tube radius--the
flow is turbulent. Thus, HeOx is shown to be superior in treating patients with breathing
problems.
Keywords: Laminar, Turbulent, Viscosity, HeOx, Endotracheal.
2. Navarun Gupta, Lawrence Hmurcik, Manan Joshi & Bhushan Dharmadhikari
International Journal of Applied Sciences (IJAS), Volume (1): Issue (2) 24
1. INTRODUCTION
The focus of this paper is to derive the critical radius rc, where rc is the radius of the pipe (throat) such that
laminar flow and turbulent flow are of equal intensity. To put this another way, rc defines the boundary
between turbulent and laminar flow. When radius < rc, the flow is turbulent. If the radius exceeds rc, the
flow becomes laminar.
The governing equation for fluid flow in a pipe is [1 - 5]
+
(1)
Where the first term describes laminar fluid flow and the second term describes turbulent flow. Equation
(1) is a form of Rohrer’s equation [3], with values of radius r set at the point where the laminar and
turbulent flows are equal. If we ignore the second term, then equation (1) becomes Ohm’s law, and all
fluid flow is laminar. In Ohm’s Law, an electromotive force (voltage) causes a flow of current through a
resistor; the length and area of the resistor factor in to the value of the resistance. In (1) a mechanical
force (the change in pressure above or below the atmospheric value (expressed in Pascals)) produces a
current or flow F (cm
3
/sec) multiplied by the resistance. The resistance is proportional to η the viscosity
(Pascal.second), the pipe length L (cm), and inversely proportional to the pipe radius r (cm). The viscosity
has a value of 18.3 (air), 20.3 (oxygen), 19.4 (helium), and 19.6 (HeOx), in units of micropascal.seconds.
L is approximately 20 to 23 cm in length for an adult. Whether the patient is intubated or not, this value
remains the same. However, the value of r is either the radius of the ETT (endotracheal tube) used to
intubate or the average radius of the airway. ETT’s are 7 to 8.5 mm, inner diameter. Patient’s airways are
larger, and they vary according to the age, sex, weight, height, and health of the patient. See references
[6, 7] for assorted data on various types of patients. The data that we quote in this paper comes from
specific patient medical records. NOTE: all medical records quoted here are purged of any specific
patient identification.
Equation 1 is true for any radius of pipe, if we ignore the second (i.e. turbulent) term. Equation 1 is true for
both terms, if the radius is equal to the critical radius (rc) or close to the value of the critical radius, i.e. the
radius where term # 1 equals term # 2. The reason for this limited range of applicability is due to the fact
that the nonlinear regime for fluid flow is complex and requires a power series expansion in the variable F
(fluid flow) to fully quantify all effects that can occur. Our concept of turbulent flow (as limited to its use in
this paper) is to describe one stage of complexity greater than simple laminar flow. Turbulent flow is
governed by F raised to the second power; the Reynolds number is fixed at 2000. As the flow increase
still further, the turbulence must be described by F raised to the third power, and later the forth, etc. Since
it is not our purpose to dwell on all of the mathematics governing the flow process, we refer to Figures 1
and 2. Normal stream lines represent laminar flow. Erratic streamlines represent turbulence. Turbulent
flow increases with increasing velocity and with bends and twists in the pipe.
FIGURE 1: Velocity profiles for laminar and turbulent flow in circular pipes [1].
3. Navarun Gupta, Lawrence Hmurcik, Manan Joshi & Bhushan Dharmadhikari
International Journal of Applied Sciences (IJAS), Volume (1): Issue (2) 25
FIGURE 2: Laminar flow (A) versus turbulent flow (B) is shown by normal straight streamlines versus short erratic
lines. (C) As a pipe’s radius decreases the fluid’s velocity increases, and the fluid changes from laminar to turbulent.
For sharp bends (D) and even for gradual bends (E) in the pipe, the laminar flow becomes turbulent, even if it is only
a local effect. This figure is adapted from Reference 8.
The pipe length is the distance from lips to bifurcation. Please note: in some hospital settings, an
endotracheal tube is inserted into the patient’s mouth. The distance from lips to bifurcation is generally 20
to 24 cm (depending on the patient and assuming the patient is an adult). However, the tube can be
inserted to a greater length (at least 4 cm longer) if it diverts to only one lung. This practice is not
recommended, however, since it is inefficient for a person with 2 functioning lungs. It is only used for
patients in whom one lung is missing or defective to the extent that the oxygen best serves the patient’s
other lung.
It is well known in electricity that Ohm’s Law breaks down if we approach the saturation current of the
conductor. This is never seen for normal conductors like copper. The reason is that the saturation current
for a normal sized copper wire is over a billion amps [9]. It takes only several hundred amps to vaporize a
copper wire. Therefore, it is impossible to obtain the saturation current. By contrast, consider a
semiconductor. Since the conductivity is orders of magnitude lower than copper or metal, the saturation
current is much lower. Consider the conduction channel in a JFET (junction field effect transistor). With no
gate voltage applied, the channel current (called the source current) will saturate if the drain-source
voltage is made too large. The value of this current is of the order of milliamps.
Just as a large increase in applied voltage pushes current to saturate, a large pressure difference causes
fluid flow to saturate. The region between linear (laminar) and saturation flow is a transition state, which
we know as turbulent flow. Complete turbulence leads to chaos and the fluid flow is a fixed value, no
matter how high the pressure. Less turbulence leads to a relationship which is quantified as the second
term in equation (1).
Term # 2 in (1) shows that the pressure difference varies as the square of the flow rate. Re is the
Reynolds number, and for the transition value between the laminar/turbulent flow in a pipe, Re = 2000 [5].
Density ρ is in units of (kg/m
3
), with the pressure still in Pascals. If we set the first and second terms in (1)
equal, we can come up with the critical radius (rc), i.e. the radius where 50% of the flow is Laminar and
50% turbulent.
Here is the approach we will take with the sick human being, i.e. patient. Ambient pressure is the
atmospheric pressure (1.01 x 10
5
Pascals). During normal human breathing, a human will exert a
pressure difference to inhale (inspiration) or exhale (expiration) air. The value of this extra pressure can
be positive or negative and it typically varies from a value of zero to 30 Pascals. TV is the tidal volume (in
cm
3
), i.e. the extra volume of the lungs as they expand to take in the fresh air. The time for inspiration and
expiration is not the same; generally it takes twice as long to expire a breath than it did to inspire it [10].
As an example, if a person breathes at the rate of 20 breaths per minute, it takes 3 seconds to complete a
4. Navarun Gupta, Lawrence Hmurcik, Manan Joshi & Bhushan Dharmadhikari
International Journal of Applied Sciences (IJAS), Volume (1): Issue (2) 26
breath, with one second spent on inspiration and 2 spent on expiration. Since the flow rate equals the
tidal volume divided by time, the flow is larger for inspiration. To put this another way, there is more
likelihood of a patient having breathing trouble during inspiration, since the flow rate is twice as large. In
this paper, we will use the time of inspiration to focus on laminar vs. turbulent flow with the idea that
whatever our results for inspiration, our results for expiration will be better, i.e. more likely laminar, since
the flow rate is cut to one half. One other thing to be noted is patients with COPD (chronic obstructive
pulmonary disease). Their expiration time is longer than normal. Hence, the inspiration time once again
becomes the more sensitive parameter in determining breathing problems.
Our focus is to show that the HeOx solution is easier to breathe than regular air [11, 12]. The change in
pressure is fixed. If the patient is on a ventilator or breathing on his own, then the change in pressure
above below atmospheric pressure is fixed for a given person. The length and radius of the patient are
also fixed and depend on the patient’s airway or ETT.
Our analysis proceeds in this fashion: set term # 1 and term #2 equal to each other. This assumes that
laminar and turbulent flows are equal. The length and all other parameters are fixed, and we compute the
radius, i.e. the critical radius (rc). We actually compute 2 values for the critical radius, one for HeOx and
one for air. Then compare this to the radius of the patient’s throat or ETT.
Table I lists the critical radius (rc) for air and HeOx as well as the radius of the person’s throat or ETT.
This data comes from the personal medical files in a hospital with the patient’s ID removed. In all cases,
HeOx is better than air, i.e. in all cases the air flow remains more like a laminar than a turbulent flow.
Patient description
#1
Radius
parameters
for a patient’s
throat or ETT
(cm)
#2
Critical
radius
(rc) using
air
(cm)
#3
Critical
radius
(rc) using
HeOx
(cm)
#4
Flow as tidal
volume divided
by inspiration
time
(cm
3
/seconds)
18 year-old female, 110 pounds,
Caucasian 4’9”, ETT-L= 21 cm, no
past medical history
0.375 0.94 0.31 500/1
39 year-old male, 205 pounds,
Caucasian, 6’2”, no ETT, L = 22 cm,
healthy
0.5 to 0.6 0.83 0.27 800/2
52 year-old male, 176 pounds, Italian,
5’8”, Tachycardia (rapid heart rate) and
breathless, no ETT, L = 30 cm
0.40 0.72 0.22 560/1.7
60 year-old female, 154 pounds,
Hispanic, after Coronary Artery graft
bypass, L=22 cm, no ETT
0.37 to 0.45 1.47 0.45 700/1
20 year-old female, 132 pounds, Black,
ETT-L = 22 cm, following minor surgery
0.375 0.63 0.33 600/2
5. Navarun Gupta, Lawrence Hmurcik, Manan Joshi & Bhushan Dharmadhikari
International Journal of Applied Sciences (IJAS), Volume (1): Issue (2) 27
56 year-old female, 132 pounds,
Hispanic, ETT-L = 22 cm, smoker and
COPD
0.36 0.63 0.19 600/2
25 year-old female, 125 pounds,
Caucasian, Pregnant, ETT-L = 21 cm
0.36 0.77 0.24 550/1.5
45 year-old male, 180 pounds,
Caucasian, in remission for cancer –
underwent right lung lobectomy to
remove 30% of right lung, emphysema,
takes shallow breaths at rapid rate on
ventilator and requires higher lung
volumes as bullae from on
eroding alveoli, ETT-L = 22 cm
0.40 0.96 0.30 550/1.5
61 year-old male, 154 pounds,
Caucasian,following coronary artery
bypass, ETT-L = 22 cm
0.40 0.47 0.14 600/1.5
27 year-old female, 132 pounds,
Hispanic, undergoes lymph node
breast biopsy, no past medical history
and no illness, ETT-L = 23 cm
0.375 0.48 0.15 450/2
30 year-old male, 154 pounds,
Causian, 5’9”, following an asthma
attack but not 0.57 intubated, L = 12.7
cm;
Note: normal flow is 500/1, but this is
reduced to 300 to 1 to include effects of
asthma
0.54 to 0.57 0.60 0.20 300/1
68 year-old male, 154 pounds, 5’6”,
mixed Asian, chronic lung
disease/emphysema, decreased lung
capacity, ETT-L = 22 cm
0.40 0.53 0.16 250/1
TABLE 1: Measured throat radius (or ETT radius), critical radius, and flow rate are cited for 13 patients.
2. CONCLUSION
There are several conclusions that we can obtain from this work. First and most important, the mixture of
oxygen and helium produces a substitute for air that is laminar, even under the most adverse conditions.
Normal, healthy people can breathe air in a fashion that is turbulent. Every sharp twist and turn between
the lips, throat, and bifurcation can cause simple, laminar flow to go turbulent. Rapid breathing also
6. Navarun Gupta, Lawrence Hmurcik, Manan Joshi & Bhushan Dharmadhikari
International Journal of Applied Sciences (IJAS), Volume (1): Issue (2) 28
increases the probability of turbulent flow. All of these conditions are of no significance in a healthy
person. But for a sick person with breath difficulty or even for a healthy person who has undergone
surgery and is intubated, the process of breathing laminar is very important. The ETT itself is generally
free from sharp bends and kinks which promote turbulent flow. In addition, the HeOx mixture lowers the
critical radius (rc) for the onset of turbulent flow by over 300 % (or a factor of more than 3). See Table I.
A second thing to be noted from Table I is that sometimes the radius of the airway is a variable, due to
the lack of simple smoothness of the throat. Even if the person is intubated, the ETT may not have the
value of radius for which it is listed. For example, an ETT with inner diameter of 8 mm has a radius of 0.4
cm. However, often the sick patient produces secretions which compromise this value so that the actual
value of the tube’s radius is lower by up to 20% [13, 14, 15]. But even in this case, the HeOx mixture
proves up to the task of maintaining laminar flow.
A third thing to be noted from our data is that there is nothing significant about the race or sex or age of
the patient. All persons studied were adults. If children and infants were included, there would, of course,
be a profound effect. But neither race nor sex nor age played a role in our overall analysis. Rather, the
patient’s size and medical history were the determining factors in our analysis. Granted, an older patient
who smokes is more likely to have a long medical history than a younger person who smokes. In that
sense, age is a strong factor. But the old and the young patient can have the same results if their medical
history and size are the same.
It should be noted that our mathematical analysis of the data in Table I shows HeOx to be better than air
in 12 of 13 cases, but in practice, all 13 patients improved their comfort with HeOx, i.e. they breathed
easier.
3. ACKNOWLEDGEMENT
We wish to thank the students in the nurse-anesthetist program at Bridgeport Hospital for their help. We
wish to thank Catherine Hmurcik BSN of the West Haven VA Hospital for useful discussions.
4. REFERENCES
1. J. Duffin, “Physics for Anesthetists”, Charles C. Thomas, Springfield, IL, ISBN 0-398-06906-9, Ch. 10,
p 160-171 (1976).
2. P. Davis and G. Kenny, “Basic Physics Measurements in Anesthesia”, 5th ed., Butterworth-
Heinemann, NY, ISBN 0-7506-4828-7, Ch. 2, p 12-17, (2003).
3. J. Guttmann, L. Ebenhard, B. Fabry, W. Bertschmann, G. Wolff, “Continuous calculation of
intratracheal pressure in tracheally intubated patients”, Anesthesiology,79(3): 503-513 (1993).
4. W. Hughes and J. Brighton, “Fluid Dynamics, Schaum’s Outline Series”, McGraw-Hill, Ch. 5, p 76-88
and Ch. 12, p 235-238 (1967).
5. L. McIntosh,” Essentials of Nurse Anesthesia”, McGraw-Hill, Ch. 2, p 31-32 (1997).
6. R. Venn, “Ventilation with lower tidal volumes as compared with traditional tidal volumes for acute
lung injury and the acute respiratory distress syndrome (ARDS)”, New England Journal of Medicine,
342: 1301-1308 (2000).
7. J. West,” Respiratory Physiology,” 7th ed., Lippincott, Williams, and Wilkins, Philadelphia, ISBN 13-
978-0-7817-5152-0 (2005).
8. J. Dorsch and S. Dorsch,” Understanding Anesthesia Equipment,” 4th ed., Williams and Wilkins,
ISBN 0-683-30487-9, Ch. 6, p 185 (1999).
7. Navarun Gupta, Lawrence Hmurcik, Manan Joshi & Bhushan Dharmadhikari
International Journal of Applied Sciences (IJAS), Volume (1): Issue (2) 29
9. G. Neudeck and R. Pierret,” Field Effect Devices, Modular Series on Solid State Devices”, 6, 2nd ed.,
Addison-Wesley, Ch. 6, p 194-195 (1990).
10. N. Petrucci and W. Iacovelli, “Ventilation with smaller tidal volumes: a quantitative systematic review
of randomized controlled trials”, International Anesthesia Research Society, 99:193-200 (2004).
11. J. Chevrolet, “Helium and mixtures with oxygen in the intensive care unit”, Critical Care, 5:179-
181(2001).
12. J. Chevrolet, "Helium and mixtures with oxygen in the intensive care unit," Critical Care, 5: 179-
181(2001).
13. N. Yahagi, K. Kumon, H. Tanigami, Y. Watanabe and J. Matsui, “Helium/oxygen breathing Improved
hypoxemia after cardiac surgery: case reports”, Anesthesia Analog, 80: 1042-1045 (1995).
14. J. Graf and J. Marini, “Do airway secretions play an underappreciated role in acute respiratory
distress syndrome (ARDS)”, Current Opinion in Critical Care. 14(1): 44-49 (2008).
15. V. Rangachari, I. Sundararajan, V. Sumathi, and K. Kumar, “Laryngeal sequelae following prolonged
intubation: a prospective study”, Indian Journal of Critical Medicine, 10(3):171-175 (2006).
16. Y. Fujino, A. Uchiyama, T. Mashimo, and M. Nishamura, “Spontaneously breathing lung model
comparison of breathing between automatic tube compensation and pressure support”, Respiratory
Care, 48, ( 1):38-45 (2003).