The document describes research into a new type of thermal actuator that uses a carbon nanotube (CNT) sheet as a flexible heating element. When voltage is applied, the CNT sheet heats up rapidly. It is bonded to a silicone elastomer substrate and polyimide film. Due to their different coefficients of thermal expansion, heating causes the actuator to bend. Experiments show the actuator can heat from room temperature to 100°C in 8 seconds and deflect up to 3mm at the tip when a voltage of 20V is applied. Finite element modeling was used to select the optimal substrate material. Silicone elastomer was chosen for its high thermal expansion and ability to operate at high temperatures.
RESEARCH ON INDUCTION HEATING - A REVIEWEditor IJCATR
This paper presents results of finite element analysis of induction heating problems considering temperature dependence of
material characteristics. In this analysis, we have used the three-dimensional finite element method in order to correctly express
induction heating coil’s shapes and to make clear its effects on temperature distributions. The heat-conducting problem and the eddy
current problem are coupled, and solved by using the step-by-step calculations.
IMAC 2010 Presentation: Error Quantification in Calibration of AFM Probes Due...frentrup
The document discusses error quantification in atomic force microscope (AFM) probe calibration due to non-uniform cantilevers. It finds that existing calibration models assume uniform beams but probes can have thickness variations. It develops parameterized models of non-uniform beams and finds the Sader method using the first vibration mode is robust with errors below 3%, while the thermal tune method is highly sensitive to non-uniformity with errors over 5% even for the first mode.
Project Presentation on Heat Conduction ApparatusZaber Ismaeel
Heat Conduction:
In heat transfer, conduction (or heat conduction) is the transfer of heat energy by microscopic diffusion and collisions of particles or quasi-particles within a body due to a temperature gradient. The microscopically diffusing and colliding objects include molecules, electrons, atoms, and phonons. They transfer microscopically disorganized kinetic and potential energy, which are jointly known as internal energy. Conduction can only take place within an object or material, or between two objects that are in direct or indirect contact with each other. Conduction takes place in almost all forms of matter, such as solids, liquids, gases and plasmas.
Thermal Conductivity of a metal:
Thermal conductivity is a measure of the ability of a substance to conduct heat, determined by the rate of heat flow normally through an area in the substance divided by the area and by minus the component of the temperature gradient in the direction of flow, measured in watts per meter per Kelvin. Symbol: K is used to denote thermal conductivity.
Investigation of heat transfer through cnt composites focusing on conduction ...IAEME Publication
1. The document investigates heat transfer through carbon nanotube composites, focusing on the conduction mode.
2. It summarizes the synthesis and preparation of aligned multi-walled carbon nanotube samples embedded in anodic aluminum oxide templates, as well as randomly oriented films of multi-walled carbon nanotubes, single-walled carbon nanotubes, and graphite powder.
3. The specific heat and thermal conductivity of the samples are measured from 300 to 400K. The specific heat of the aligned nanotube sample has weaker temperature dependence than the random films and bulk graphite. The thermal conductivity of the aligned sample increases with temperature, while the random films and graphite show a
Hot Disk Transient Plane Source Technique - Thermal ConductivityMichael Thomas
Method and operation of the Hot Disk transient plane source (TPS) technique for the measurement of thermal conductivity, thermal diffusivity and specific heat. The TPS technique can test solids, liquids, powders and pastes of varying shapes and sizes.
1) The chapter discusses heat conduction and the governing equation for one-dimensional, steady-state heat conduction through a plane wall.
2) It derives the transient, one-dimensional heat conduction equations for plane walls, long cylinders, and spheres. These equations can be simplified for steady-state and cases without heat generation.
3) The chapter also covers boundary and initial conditions like specified temperature, heat flux, convection, radiation, and interfaces. Governing equations are developed for multidimensional and transient heat conduction problems.
This document summarizes a standard test method for measuring the thermal transmission properties of thermally conductive electrical insulation materials. It describes measuring a material's thermal impedance using a test setup with two parallel isothermal surfaces that impose a temperature gradient on a test specimen in between. Measurements of the surface temperatures and heat flow rate are used to calculate the specimen's thermal impedance and apparent thermal conductivity. The test method can be used to evaluate liquids, gels, rubbers, ceramics, metals and some plastics. Adjusting the clamping pressure and applying thermal grease can help account for interfacial thermal resistance between the specimen and test surfaces.
Smart nanotechnology materials have been recently utilized in sensing applications. Carbon
nanotube (CNT) based SoC sensor systems have potential applications in various fields,
including medical, energy, consumer electronics, computers, and HVAC (heating, ventilation,
and air conditioning) among others. In this study, a nanotechnology multisensory system was
designed and simulated using Labview Software. The mathematical models were developed for
sensing three physical quantities: temperature, gas, and pressure. Four CNT groups on a chip
(two for gas sensor, one for temperature, and a fourth one for pressure) were utilized in order to
perform sensing multiple parameters. The proposed fabrication processes and the materials
used were chosen to avoid the interference of these parameters on each other when detecting
one of them. The simulation results were translated into analog voltage from Labview software,
transmitted via Bluetooth network, and received on desktop computers within the vicinity of the
sensor system. The mathematical models and simulation results showed as high as 95%
accuracy in measuring temperature, and the 5% error was caused from the interference of the surrounding gas. Within 7% change in pressure was impacted by both temperature and gas interference.
RESEARCH ON INDUCTION HEATING - A REVIEWEditor IJCATR
This paper presents results of finite element analysis of induction heating problems considering temperature dependence of
material characteristics. In this analysis, we have used the three-dimensional finite element method in order to correctly express
induction heating coil’s shapes and to make clear its effects on temperature distributions. The heat-conducting problem and the eddy
current problem are coupled, and solved by using the step-by-step calculations.
IMAC 2010 Presentation: Error Quantification in Calibration of AFM Probes Due...frentrup
The document discusses error quantification in atomic force microscope (AFM) probe calibration due to non-uniform cantilevers. It finds that existing calibration models assume uniform beams but probes can have thickness variations. It develops parameterized models of non-uniform beams and finds the Sader method using the first vibration mode is robust with errors below 3%, while the thermal tune method is highly sensitive to non-uniformity with errors over 5% even for the first mode.
Project Presentation on Heat Conduction ApparatusZaber Ismaeel
Heat Conduction:
In heat transfer, conduction (or heat conduction) is the transfer of heat energy by microscopic diffusion and collisions of particles or quasi-particles within a body due to a temperature gradient. The microscopically diffusing and colliding objects include molecules, electrons, atoms, and phonons. They transfer microscopically disorganized kinetic and potential energy, which are jointly known as internal energy. Conduction can only take place within an object or material, or between two objects that are in direct or indirect contact with each other. Conduction takes place in almost all forms of matter, such as solids, liquids, gases and plasmas.
Thermal Conductivity of a metal:
Thermal conductivity is a measure of the ability of a substance to conduct heat, determined by the rate of heat flow normally through an area in the substance divided by the area and by minus the component of the temperature gradient in the direction of flow, measured in watts per meter per Kelvin. Symbol: K is used to denote thermal conductivity.
Investigation of heat transfer through cnt composites focusing on conduction ...IAEME Publication
1. The document investigates heat transfer through carbon nanotube composites, focusing on the conduction mode.
2. It summarizes the synthesis and preparation of aligned multi-walled carbon nanotube samples embedded in anodic aluminum oxide templates, as well as randomly oriented films of multi-walled carbon nanotubes, single-walled carbon nanotubes, and graphite powder.
3. The specific heat and thermal conductivity of the samples are measured from 300 to 400K. The specific heat of the aligned nanotube sample has weaker temperature dependence than the random films and bulk graphite. The thermal conductivity of the aligned sample increases with temperature, while the random films and graphite show a
Hot Disk Transient Plane Source Technique - Thermal ConductivityMichael Thomas
Method and operation of the Hot Disk transient plane source (TPS) technique for the measurement of thermal conductivity, thermal diffusivity and specific heat. The TPS technique can test solids, liquids, powders and pastes of varying shapes and sizes.
1) The chapter discusses heat conduction and the governing equation for one-dimensional, steady-state heat conduction through a plane wall.
2) It derives the transient, one-dimensional heat conduction equations for plane walls, long cylinders, and spheres. These equations can be simplified for steady-state and cases without heat generation.
3) The chapter also covers boundary and initial conditions like specified temperature, heat flux, convection, radiation, and interfaces. Governing equations are developed for multidimensional and transient heat conduction problems.
This document summarizes a standard test method for measuring the thermal transmission properties of thermally conductive electrical insulation materials. It describes measuring a material's thermal impedance using a test setup with two parallel isothermal surfaces that impose a temperature gradient on a test specimen in between. Measurements of the surface temperatures and heat flow rate are used to calculate the specimen's thermal impedance and apparent thermal conductivity. The test method can be used to evaluate liquids, gels, rubbers, ceramics, metals and some plastics. Adjusting the clamping pressure and applying thermal grease can help account for interfacial thermal resistance between the specimen and test surfaces.
Smart nanotechnology materials have been recently utilized in sensing applications. Carbon
nanotube (CNT) based SoC sensor systems have potential applications in various fields,
including medical, energy, consumer electronics, computers, and HVAC (heating, ventilation,
and air conditioning) among others. In this study, a nanotechnology multisensory system was
designed and simulated using Labview Software. The mathematical models were developed for
sensing three physical quantities: temperature, gas, and pressure. Four CNT groups on a chip
(two for gas sensor, one for temperature, and a fourth one for pressure) were utilized in order to
perform sensing multiple parameters. The proposed fabrication processes and the materials
used were chosen to avoid the interference of these parameters on each other when detecting
one of them. The simulation results were translated into analog voltage from Labview software,
transmitted via Bluetooth network, and received on desktop computers within the vicinity of the
sensor system. The mathematical models and simulation results showed as high as 95%
accuracy in measuring temperature, and the 5% error was caused from the interference of the surrounding gas. Within 7% change in pressure was impacted by both temperature and gas interference.
1. The document discusses 1D steady state heat conduction through two solid plates in contact. It describes how heat transfer occurs through the interface via solid contact spots and gaps, and defines thermal contact resistance.
2. Thermal contact resistance values reported in experiments typically fall between 0.000005 and 0.0005 m2·°C/W. The corresponding thermal contact conductance ranges from 2000 to 200,000 W/m2·°C.
3. The importance of considering thermal contact resistance in heat transfer problems is discussed.
6th ed solution manual---fundamentals-of-heat-and-mass-transferRonald Tenesaca
This document contains 10 problems related to heat transfer by conduction. Each problem provides known information such as materials, dimensions, temperatures, and heat transfer rates. The problems then ask the reader to find unknown values like heat fluxes, surface temperatures, or thicknesses using Fourier's Law of heat conduction and assumptions of one-dimensional and steady-state heat transfer. The problems cover a variety of applications including insulation, walls, windows, refrigeration, and cooking.
International Conference of Fracture 2017: A procedure to determine the fracture properties of nuclear cladding from ring compression tests. A parametric study
Thermal contact resistance depends on surface roughness, material properties, temperature and pressure at the interface, and type of fluid trapped at the interface. The critical radius of insulation determines if insulation will help or hurt heat transfer. Internal heat generation in walls or cylinders means thermal resistance concept is not correct, and temperature will be non-linear.
Heat transfer 5th ed incropera solution manualManish Kumar
This document presents 13 problems related to heat transfer through walls, slabs, windows, and other materials via one-dimensional conduction. The problems provide known parameters like material properties, dimensions, temperatures, and heat flux/rates. The goal is to use Fourier's law of conduction to find unknowns like temperature differences, thermal conductivities, thickness of insulation needed, or heat loss/flux. Assumptions include one-dimensional steady-state conduction with constant properties. Solutions show the analysis and application of Fourier's law to solve for the requested unknowns.
A Project report on Heat Conduction ApparatusZaber Ismaeel
Heat Conduction:
In heat transfer, conduction (or heat conduction) is the transfer of heat energy by microscopic diffusion and collisions of particles or quasi-particles within a body due to a temperature gradient. The microscopically diffusing and colliding objects include molecules, electrons, atoms, and phonons. They transfer microscopically disorganized kinetic and potential energy, which are jointly known as internal energy. Conduction can only take place within an object or material, or between two objects that are in direct or indirect contact with each other. Conduction takes place in almost all forms of matter, such as solids, liquids, gases and plasmas.
Thermal Conductivity of a metal:
Thermal conductivity is a measure of the ability of a substance to conduct heat, determined by the rate of heat flow normally through an area in the substance divided by the area and by minus the component of the temperature gradient in the direction of flow, measured in watts per meter per Kelvin. Symbol: K is used to denote thermal conductivity.
The document discusses heat conduction equations in various coordinate systems and geometries:
1) It presents Fourier's law of heat conduction and derives the one-dimensional heat conduction equation.
2) It then extends the derivation to multidimensional systems, deriving equations for cylindrical and spherical geometries with variable or constant conductivity.
3) Finally, it presents the general three-dimensional heat conduction equation applicable to problems involving transient or steady heat transfer in solids with arbitrary geometries and material properties.
This file contains slides on One-dimensional, steady state heat conduction without heat generation. The slides were prepared while teaching Heat Transfer course to the M.Tech. students.
Topics covered: Plane slab - composite slabs – contact resistance – cylindrical Systems – composite cylinders - spherical systems – composite spheres - critical thickness of insulation – optimum thickness – systems with variable thermal conductivity
This document discusses the optimization of a self-activating bi-metallic valve using thermo-structural coupled finite element analysis. The valve is intended for use in a process to generate nitrous oxide from ammonium nitrate, with the goal of maintaining safe temperatures between 170-200°C. Non-linear finite element analysis is used to optimize the dimensions of the bi-metallic strip in the valve and an associated warning system to achieve the desired deflection based on temperature changes. The analysis accounts for material non-linearities, contact behavior, and large deformations to determine the opening and closing of the valve and warning system at different process temperatures.
Ansys temperature distribution and heat flux furnace jan 10 2013 updatedCharlton Inao
This document discusses performing a finite element analysis (FEA) thermal analysis of a furnace to determine temperature distribution and heat flux. It provides details on the furnace dimensions, material properties of the concrete and brick walls, convection heat transfer coefficients, and temperatures of the furnace interior and surrounding air. The steps outlined include defining element types, material thermal conductivities, modeling the furnace geometry, meshing, and assigning material numbers to the concrete and brick walls in the FEA software before running the thermal analysis.
This document describes experiments conducted to determine the thermal conductivity of various materials and liquids. In experiment 1A, a guarded hot plate apparatus is used to measure the thermal conductivity of an insulating material sample. Experiment 1B involves determining the thermal conductivity of insulating powder packed between two copper spheres. Experiment 1C measures the thermal conductivity of a liquid using a guarded hot plate assembly to ensure one-dimensional heat conduction. Experiment 1D demonstrates a heat pipe and compares its temperature response over time to copper pipes, showing the heat pipe's nearly isothermal temperature distribution.
Mathcad Functions for Conduction heat transfer calculationstmuliya
This file contains notes on Mathcad Functions for Conduction heat transfer calculations. Some problems are also included.
These notes were prepared while teaching Heat Transfer course to the M.Tech. students in Mechanical Engineering Dept. of St. Joseph Engineering College, Vamanjoor, Mangalore, India.
It is hoped that these notes will be useful to teachers, students, researchers and professionals working in this field.
The document provides information about calculating heat loss from a furnace and exhaust duct. It gives dimensions, material properties, and temperature values. It then shows calculations to determine the total heat loss over 24 hours from the furnace, which is 801.65 MJ. For the exhaust duct, it uses a trial-and-error method to calculate the interface temperature and heat loss.
This document discusses heat transfer through conduction and various methods for solving the heat equation using finite difference approximations. It introduces the heat equation in Cartesian, cylindrical and spherical coordinates. It discusses boundary conditions and describes setting up a nodal network to discretize the domain. It then presents the finite difference form of the heat equation and describes different cases for nodal finite difference equations, including for interior nodes, nodes at corners or surfaces with convection, and nodes at surfaces with uniform heat flux. It discusses solving the finite difference equations using matrix inversion, Gauss-Seidel iteration, and provides examples.
This document discusses hypotheses, providing definitions, types, and characteristics. It defines a hypothesis as a provisional explanation for a phenomenon that can be tested. Hypotheses guide research and can be universal, existential, null, alternate, directional, or non-directional. They specify variables, populations, and relationships to be empirically tested. The document also outlines the process of developing a hypothesis from selecting a topic to writing a simple, testable statement.
This document discusses measures of central tendency including the mean, median, and mode. It provides definitions and formulas for calculating each measure. The mean is the average and is calculated by summing all values and dividing by the total number of items. The median is the middle value when items are arranged from lowest to highest. The mode is the value that occurs most frequently in a data set. Examples are given to demonstrate calculating each measure using raw data.
Este documento resume las novedades de varios youtubers e influencers colombianos como J Balvin, Maluma, PaisaVlogs, Juana Martínez y Juan Pablo Jaramillo. También presenta breves biografías de Mario Ruiz y Sebastián Villalobos, describiendo aspectos de sus vidas y carreras en YouTube.
Este documento presenta la asignatura de Epistemología y Educación que forma parte de la Maestría en Tecnologías Aplicadas a la Educación. El curso se centra en definir la epistemología y su relación con la educación, describir las principales escuelas epistemológicas, y comprender cómo la naturaleza del conocimiento influye en los procesos de enseñanza y aprendizaje.
This snapshot has been compiled to give an overview of the FPO of Shikhar Insurance Company Limited (SICL) to interested investors willing to apply in the upcoming Further Public Offerings of the ordinary shares by the SICL.
1. The document discusses 1D steady state heat conduction through two solid plates in contact. It describes how heat transfer occurs through the interface via solid contact spots and gaps, and defines thermal contact resistance.
2. Thermal contact resistance values reported in experiments typically fall between 0.000005 and 0.0005 m2·°C/W. The corresponding thermal contact conductance ranges from 2000 to 200,000 W/m2·°C.
3. The importance of considering thermal contact resistance in heat transfer problems is discussed.
6th ed solution manual---fundamentals-of-heat-and-mass-transferRonald Tenesaca
This document contains 10 problems related to heat transfer by conduction. Each problem provides known information such as materials, dimensions, temperatures, and heat transfer rates. The problems then ask the reader to find unknown values like heat fluxes, surface temperatures, or thicknesses using Fourier's Law of heat conduction and assumptions of one-dimensional and steady-state heat transfer. The problems cover a variety of applications including insulation, walls, windows, refrigeration, and cooking.
International Conference of Fracture 2017: A procedure to determine the fracture properties of nuclear cladding from ring compression tests. A parametric study
Thermal contact resistance depends on surface roughness, material properties, temperature and pressure at the interface, and type of fluid trapped at the interface. The critical radius of insulation determines if insulation will help or hurt heat transfer. Internal heat generation in walls or cylinders means thermal resistance concept is not correct, and temperature will be non-linear.
Heat transfer 5th ed incropera solution manualManish Kumar
This document presents 13 problems related to heat transfer through walls, slabs, windows, and other materials via one-dimensional conduction. The problems provide known parameters like material properties, dimensions, temperatures, and heat flux/rates. The goal is to use Fourier's law of conduction to find unknowns like temperature differences, thermal conductivities, thickness of insulation needed, or heat loss/flux. Assumptions include one-dimensional steady-state conduction with constant properties. Solutions show the analysis and application of Fourier's law to solve for the requested unknowns.
A Project report on Heat Conduction ApparatusZaber Ismaeel
Heat Conduction:
In heat transfer, conduction (or heat conduction) is the transfer of heat energy by microscopic diffusion and collisions of particles or quasi-particles within a body due to a temperature gradient. The microscopically diffusing and colliding objects include molecules, electrons, atoms, and phonons. They transfer microscopically disorganized kinetic and potential energy, which are jointly known as internal energy. Conduction can only take place within an object or material, or between two objects that are in direct or indirect contact with each other. Conduction takes place in almost all forms of matter, such as solids, liquids, gases and plasmas.
Thermal Conductivity of a metal:
Thermal conductivity is a measure of the ability of a substance to conduct heat, determined by the rate of heat flow normally through an area in the substance divided by the area and by minus the component of the temperature gradient in the direction of flow, measured in watts per meter per Kelvin. Symbol: K is used to denote thermal conductivity.
The document discusses heat conduction equations in various coordinate systems and geometries:
1) It presents Fourier's law of heat conduction and derives the one-dimensional heat conduction equation.
2) It then extends the derivation to multidimensional systems, deriving equations for cylindrical and spherical geometries with variable or constant conductivity.
3) Finally, it presents the general three-dimensional heat conduction equation applicable to problems involving transient or steady heat transfer in solids with arbitrary geometries and material properties.
This file contains slides on One-dimensional, steady state heat conduction without heat generation. The slides were prepared while teaching Heat Transfer course to the M.Tech. students.
Topics covered: Plane slab - composite slabs – contact resistance – cylindrical Systems – composite cylinders - spherical systems – composite spheres - critical thickness of insulation – optimum thickness – systems with variable thermal conductivity
This document discusses the optimization of a self-activating bi-metallic valve using thermo-structural coupled finite element analysis. The valve is intended for use in a process to generate nitrous oxide from ammonium nitrate, with the goal of maintaining safe temperatures between 170-200°C. Non-linear finite element analysis is used to optimize the dimensions of the bi-metallic strip in the valve and an associated warning system to achieve the desired deflection based on temperature changes. The analysis accounts for material non-linearities, contact behavior, and large deformations to determine the opening and closing of the valve and warning system at different process temperatures.
Ansys temperature distribution and heat flux furnace jan 10 2013 updatedCharlton Inao
This document discusses performing a finite element analysis (FEA) thermal analysis of a furnace to determine temperature distribution and heat flux. It provides details on the furnace dimensions, material properties of the concrete and brick walls, convection heat transfer coefficients, and temperatures of the furnace interior and surrounding air. The steps outlined include defining element types, material thermal conductivities, modeling the furnace geometry, meshing, and assigning material numbers to the concrete and brick walls in the FEA software before running the thermal analysis.
This document describes experiments conducted to determine the thermal conductivity of various materials and liquids. In experiment 1A, a guarded hot plate apparatus is used to measure the thermal conductivity of an insulating material sample. Experiment 1B involves determining the thermal conductivity of insulating powder packed between two copper spheres. Experiment 1C measures the thermal conductivity of a liquid using a guarded hot plate assembly to ensure one-dimensional heat conduction. Experiment 1D demonstrates a heat pipe and compares its temperature response over time to copper pipes, showing the heat pipe's nearly isothermal temperature distribution.
Mathcad Functions for Conduction heat transfer calculationstmuliya
This file contains notes on Mathcad Functions for Conduction heat transfer calculations. Some problems are also included.
These notes were prepared while teaching Heat Transfer course to the M.Tech. students in Mechanical Engineering Dept. of St. Joseph Engineering College, Vamanjoor, Mangalore, India.
It is hoped that these notes will be useful to teachers, students, researchers and professionals working in this field.
The document provides information about calculating heat loss from a furnace and exhaust duct. It gives dimensions, material properties, and temperature values. It then shows calculations to determine the total heat loss over 24 hours from the furnace, which is 801.65 MJ. For the exhaust duct, it uses a trial-and-error method to calculate the interface temperature and heat loss.
This document discusses heat transfer through conduction and various methods for solving the heat equation using finite difference approximations. It introduces the heat equation in Cartesian, cylindrical and spherical coordinates. It discusses boundary conditions and describes setting up a nodal network to discretize the domain. It then presents the finite difference form of the heat equation and describes different cases for nodal finite difference equations, including for interior nodes, nodes at corners or surfaces with convection, and nodes at surfaces with uniform heat flux. It discusses solving the finite difference equations using matrix inversion, Gauss-Seidel iteration, and provides examples.
This document discusses hypotheses, providing definitions, types, and characteristics. It defines a hypothesis as a provisional explanation for a phenomenon that can be tested. Hypotheses guide research and can be universal, existential, null, alternate, directional, or non-directional. They specify variables, populations, and relationships to be empirically tested. The document also outlines the process of developing a hypothesis from selecting a topic to writing a simple, testable statement.
This document discusses measures of central tendency including the mean, median, and mode. It provides definitions and formulas for calculating each measure. The mean is the average and is calculated by summing all values and dividing by the total number of items. The median is the middle value when items are arranged from lowest to highest. The mode is the value that occurs most frequently in a data set. Examples are given to demonstrate calculating each measure using raw data.
Este documento resume las novedades de varios youtubers e influencers colombianos como J Balvin, Maluma, PaisaVlogs, Juana Martínez y Juan Pablo Jaramillo. También presenta breves biografías de Mario Ruiz y Sebastián Villalobos, describiendo aspectos de sus vidas y carreras en YouTube.
Este documento presenta la asignatura de Epistemología y Educación que forma parte de la Maestría en Tecnologías Aplicadas a la Educación. El curso se centra en definir la epistemología y su relación con la educación, describir las principales escuelas epistemológicas, y comprender cómo la naturaleza del conocimiento influye en los procesos de enseñanza y aprendizaje.
This snapshot has been compiled to give an overview of the FPO of Shikhar Insurance Company Limited (SICL) to interested investors willing to apply in the upcoming Further Public Offerings of the ordinary shares by the SICL.
The document discusses various topics relating to training and developing employees, including:
1) The purpose and process of employee orientation to help new employees feel welcome and understand expectations.
2) The four-step training process of instructional design, needs analysis, program implementation, and evaluation.
3) Different training methods such as on-the-job training, lectures, and programmed learning.
This document discusses Alitalia's digital strategy to create intimacy and loyalty with customers by engaging them throughout their travel journey ("every moment"). Key points include:
- Alitalia.com aims to be the preferred online marketplace through personalization, contextual content, and excellent customer service.
- Online sales have grown 11% in 2015 and are targeted to grow 21% in 2016, with 1 in 3 customers buying online.
- The digital strategy focuses on inspiring customers, enabling them to search/plan, buy, prepare, and experience/share their trips through a seamless online experience.
The effect of magnetic field direction on thermoelectric and thermomagnetic c...Muhammid Al-Baghdadi
This document investigates the effect of magnetic field direction on thermoelectric and thermomagnetic coefficients of undoped single crystalline InSb at room temperature. It describes how samples of InSb were tested under varying magnetic fields and temperature gradients to measure the Seebeck and Nernst coefficients. The results showed that the Seebeck coefficient depended only on the temperature gradient, while the Nernst coefficient depended on both the temperature gradient and magnetic field. However, the values of the thermoelectric and thermomagnetic coefficients were found to be independent of the direction of the applied magnetic field with respect to the InSb sample surface.
This document summarizes an experiment to measure the out-of-plane thermal conductivity of flexible substrate materials like polyethylene naphthalate (PEN) and polyethylene teraphthalate (PET). A steady-state method is used where a heat flux is applied through one copper block in contact with the substrate, and the temperature difference across the substrate is measured. Thermal conductivity values are determined from the temperature differences and heat fluxes for substrates of varying thicknesses. The results indicate low thermal conductivity for flexible substrates, which could challenge thermal management in flexible electronics due to limited heat spreading and lack of active cooling options.
Investigation of heat transfer through cnt composites focusing on conduction ...iaemedu
This document summarizes a study that investigated the heat transfer properties of carbon nanotube (CNT) composites, with a focus on conduction mode heat transfer. Multi-wall carbon nanotubes were synthesized using chemical vapor deposition inside anodic aluminum oxide templates to create aligned CNT composites. Randomly oriented CNT and graphite films were also prepared. Specific heat capacity and thermal conductivity measurements from 300-400K revealed that aligned CNT composites had higher thermal conductivity than randomly oriented films, demonstrating the anisotropic heat transfer properties of aligned CNT structures. Randomly oriented CNT and graphite films showed similar thermal properties.
Investigation of heat transfer through cnt composites focusing on conduction ...IAEME Publication
This document summarizes a study that investigated the heat transfer properties of carbon nanotube (CNT) composites, with a focus on conduction mode heat transfer. Multi-wall carbon nanotubes were synthesized using chemical vapor deposition inside anodic aluminum oxide templates to create aligned CNT composites. Randomly oriented CNT and graphite films were also prepared. Specific heat capacity and thermal conductivity were measured for the different materials from 300-400K using an AC calorimetric technique. Results showed the aligned CNT composite had higher thermal conductivity than the random films, demonstrating the anisotropic heat transfer along the CNT axes.
Investigation of heat transfer through cnt composites focusing on conduction ...iaemedu
1. The document investigates the heat transfer properties of carbon nanotube composites, focusing on the conduction mode of heat transfer.
2. It analyzes the specific heat and thermal conductivity of aligned multi-walled carbon nanotubes embedded in anodic aluminum oxide templates, as well as randomly oriented films of multi-walled carbon nanotubes, single-walled carbon nanotubes, and graphite powder.
3. The results show that the specific heat of the randomly oriented films is similar to bulk graphite powder, while the aligned nanotubes have a weaker temperature dependence. The thermal conductivity of the randomly oriented films behaves similarly to graphite and is dominated by phonon boundary scattering, while
Investigation of heat transfer through cnt composites focusing on conduction ...IAEME Publication
1. The document investigates the heat transfer properties of carbon nanotube composites, focusing on the conduction mode of heat transfer.
2. It analyzes the specific heat and thermal conductivity of aligned multi-walled carbon nanotubes embedded in anodic aluminum oxide templates, as well as randomly oriented films of multi-walled carbon nanotubes, single-walled carbon nanotubes, and graphite powder.
3. The results show that the specific heat of the randomly oriented films is similar to bulk graphite powder, while the aligned nanotubes have a weaker temperature dependence. The thermal conductivity of the randomly oriented films behaves similarly to graphite and is dominated by phonon boundary scattering, while
Analysis of polymer polymethyl metha-acralyte and single-wall cnt compositesIAEME Publication
This document discusses analysis of polymer composites made of polymethyl-metha-acrylate (PMMA) and single-wall carbon nanotubes (SWCNTs). Modulation calorimetry techniques such as ACC and MDSC are used to study the thermal properties and glass transition dynamics of the composites. The ACC results show that the effective thermal conductivity of the composites increases with higher SWCNT content, agreeing with theoretical models. MDSC indicates the SWCNTs may quench glassy structural dynamics in PMMA and reduce the hysteresis between heating and cooling curves. Overall the study analyzes the thermal properties of PMMA-SWCNT composites using advanced calorimetry methods.
Experimental Investigation of Heat Transfer by Electrically Heated Rectangula...IRJET Journal
This document presents an experimental investigation of heat transfer from an electrically heated rectangular surface by natural convection. The experiment measured the temperature distribution of air around a flat aluminum plate heated to temperatures between 347-365K at various angles from vertical. As the plate angle increased, the slope of the dimensionless temperature curve decreased, showing angle affects heat transfer. The Nusselt number also varied with angle. The experimental data agreed with previous work for vertical plates and showed temperature was independent of distance horizontally. The results provide insight into heat transfer behavior from inclined surfaces.
Ph d defense_rajmohan_muthaiah_University_of_oklahoma_07_28_2021Rajmohan Muthaiah
This slide describes the thermal transport in polymers, polymer nanocomposites and semiconductors using molecular dynamics simulations and first principles calculations
Thermal conductivity can be measured through steady state or unsteady state methods. Steady state methods maintain a constant temperature difference over time and include the guarded hot plate, concentric cylinder, and concentric sphere methods. Unsteady state methods measure temperature changes over time and are quicker but more difficult to analyze mathematically. Common instruments to measure thermal conductivity include the transient plane source method, hot wire method, laser flash method, 3-ω method, and time domain thermo reflectance method. Each uses different testing techniques and can measure different material types and property ranges.
Thermal and fluid characteristics of three-layer microchannels heat sinksjournal ijrtem
ABSTRACT : A heat sink with three layers of microchannels with different flow arrangements has been studied numerically using CFD fluent software version 15. The different flow arrangements using uniform and divergence channels on thermal characteristics of heat sinks at the same mass flow rate are investigated. The results indicated that, uniform channels with counter-flow 1 arrangement provide the best temperature uniformity and divergence channels with counter flow gives the best heat sink performance.
Cfd simulation of telecommunications cabinetmahdi Mokrane
This document discusses simulations of cooling a telecommunications cabinet prototype using computational fluid dynamics (CFD). It presents the following key points:
1) A CFD model was created using GAMBIT meshing software to simulate air flow and heat transfer within a telecommunications cabinet measuring 0.65x0.65x0.30 m containing a heating element.
2) Simulations were run with and without ventilation openings, showing ventilation is needed to maintain safe temperature levels inside the closed cabinet.
3) Forced convection cooling via an air inlet and outlets was able to maintain air temperatures of 309-311K, an improvement of 8-10K over the natural convection scenario without openings.
This document analyzes heat transfer from a finned-tube heat exchanger. It begins with an introduction to heat exchangers and finned tubes, then presents the problem statement analyzing heat transfer from a pipe with annular fins exposed to glycol fluid. Calculations are shown for heat transfer with and without fins, finding a 16.81 kW rate with fins and 15.28 kW without. Simulation in ANSYS is used to verify the calculations, finding 18.93 kW with fins and 15.28 kW without. Mesh refinement could improve accuracy between simulated and theoretical values.
This document discusses micro electro discharge machining (micro-EDM) of carbon nanotube (CNT)-reinforced polymer composites. CNT-polymer composites were fabricated and then micro-EDM was used to drill micro-scale holes in the composites. A design of experiments approach was used to investigate the effects of CNT loading, supply voltage, pulse duration, and pulse ratio on material removal rate and hole size. Supply voltage had the largest effect on material removal rate, while pulse ratio most influenced hole size. Hole sizes tended to be larger when parameters resulted in lower material removal rates. SEM images showed typical micro-EDM surface features including recast layers and debris.
An experimental investigation of annular fins under forced convectioneSAT Journals
Abstract
Heat transfer characteristics under forced convection are investigated experimentally by varying parameters like surface area,
base-to-ambient temperature difference and Reynolds number. To investigate the performance of fins experimentally, fins made of
aluminium (high thermal conductivity) are taken. For varying the surface area fin with 11 mm diameter without circumferential
fins, fin with 31 mm diameter and annular fins of 31 mm diameter are taken as specimens. Base to ambient temperature difference
is varied with the aid of dimmerstat ranging from 25W to 45W. Reynolds number is also varied by varying the velocities of air.
Velocities are varied by the aid of fan. Then these fins are tested under different load conditions, different Reynolds number by
varying the surface area of fins increase the rate of heat transfer. With the variation of relevant parameters under forced
convection heat transfer rates are analyzed experimentally. Experiments are conducted by using the annular fins, fin with
diameter 11mm without circumferential fins and fin with diameter 31mm at different Reynolds number and loads under forced
convection and comparison is made between fins. Experimental results shows that forced convection heat transfer rate from fins
depend on surface areas, base ambient temperature difference and Reynolds number. The base temperature for annular fins is
reduced by 30% when compared to fin with diameter 11mm due to increase in surface area about 40%. The base temperature for
annular fins is reduced by 10% when compared to fin with diameter of 31mm due to decrease in surface area about 41%. It is
also observed that at higher heat load i.e., 45W, the overall fin efficiency of annular fins is increased by 44% and 8% compared to
fin with diameter of 11mm and 31mm respectively. At higher Reynolds number range 800-2000, heat transfer rate increases in
annular fins due to more number of air molecules get in contact with the heated surface
The document summarizes an experimental and theoretical study of heat transfer by natural convection of a commercially available heat sink used for cooling an electronic chip. Experiments were conducted where electrical heating was used to supply heat to the heat sink and temperature measurements were taken at different locations. A theoretical 2D model was also developed using finite volume discretization to model heat transfer through the base plate. Heat transfer coefficients were calculated from the experimental temperatures and compared to theoretical predictions. The study aimed to analyze heat transfer of the heat sink and compare experimental and theoretical temperature results.
Experimental Investigation of Natural Convection Heat Transfer Enhancement fr...IRJET Journal
This document describes an experimental investigation of natural convection heat transfer from rectangular fin arrays with combinations of V-notches and perforations. Four fin array configurations were tested: one without notches or perforations (un-notched), and three with different combinations of V-notches and perforations removing different percentages of the fin area. The fin arrays were heated to different temperatures and the resulting heat transfer coefficients were measured and compared. The results showed that the combination of V-notches and perforations both increased the surface area and the turbulence near the fins, allowing more air contact and higher heat transfer coefficients compared to the un-notched fins. Among the configurations tested, the fin array with 20% of its area removed
This document discusses thermoelectric effects in magnetic nanostructures. It introduces thermoelectricity and the Peltier and Seebeck effects. Nano-crystalline alloys are important for their soft magnetic properties and size/weight reductions. Thermoelectric materials like bismuth telluride are discussed. Applications include energy production, sensors, and coatings. Advantages of thermoelectric generators are their maintenance-free operation, environmental friendliness, compact size, and reliability. The conclusion predicts a magneto-Peltier effect could be observable in spin valves with thicknesses smaller than the spin-flip diffusion length.
This document contains a 20-part assignment on heat and mass transfer. It includes problems related to conduction, convection, and fins. Some key topics covered are steady-state and transient heat conduction, boundary layer formation, heat transfer coefficients, and calculations involving cylindrical and spherical geometry. Students are asked to calculate heat transfer rates, temperature distributions, boundary layer thicknesses, fin efficiencies, and more for a variety of conductive and convective heat transfer scenarios.
Recent advances in semiconductor technology show the improvement of fabrication on
electronics appliances in terms of performance, power density and even the size. This great achievement
however led to some major problems on thermal and heat distribution of the electronic devices. This
thermal problem could reduce the efficiency and reliability of the electronic devices. In order to minimize
this thermal problem, an optimal cooling techniques need to be applied during the operation. There are
various cooling techniques have been used and one of them is passive pin fin heat sink approach. This
paper focuses on inline pin fin heat sink, which use copper material with different shapes of pin fin and a
constant 5.5W heat sources. The simulation model has been formulated using COMSOL Multiphysics
software to stimulate the pin fin design, study the thermal distribution and the maximum heat profile.