...MECHANICAL ENGINEERING DETERMINATION OF THERMAL CONDUCTIVITY OF WASTE MATERIAL (PLASTICS) MECHANICAL ENGINEERING LABORATORY 2 ME 11L SUBMITTED BY: Alega, Ulysses Jr. H. Bicaldo, Mark Zedrick L. Engaño, Moises A. Sabida, Ricalyn B. SUBMITTED TO: Engr. Manuel E. Europeo March 10, 2014 INTRODUCTION Heat conduction (or thermal conduction) is the transfer of internal 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 disorganized microscopic 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 all forms of ponderable, such as solids, liquids, gases and plasmas. Whether by conduction or by thermal radiation, heat spontaneously flows from a hotter to a colder body. In the absence of external drivers, temperature differences decay over time, and the bodies approach thermal equilibrium. In conduction, the heat flow is within and through the body itself. In contrast, in heat transfer by thermal radiation, the transfer is often between bodies, which can be spatially separate. Also possible is transfer of heat by a combination of conduction and thermal radiation. In convection, internal energy...
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... I) Cold working J) Carbon fiber Composite materials K) Glass reinforced plastics L) Reinforced concrete M) Galvanic corrosion N) Corrosion Protection O) Dye penetrant (NDI) P) Eddy current (NDI) Q) Elastomers R) Jominy and hardenability S) Polymers T) Thermoplastics U) Thermosets V) Superplasticity W) Nano materials X) Meta materials Y) Single crystal growth Z) Superconductivity [) Electrochemical Cell \) Catholic protection ]) Thermal Expansion ^) Thermal Conductivity _) Electrical Conductivity `) Magnetic Materials...
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...A Study of Thermal Conductivity of Corn Cob Ash Blended Cement Mortar. A.A. Raheem, Ph.D.1* and Prof. D.A. Adesanya2 1 Civil Engineering Department, Ladoke Akintola University of Technology, Ogbomoso, Nigeria. 2 Building Department, Obafemi Awolowo University, Ile-Ife, Nigeria. E-mail: raheemayinde@yahoo.com* Telephone: 2348033928991 ABSTRACT This study investigated the thermal conductivity of corn cob ash (CCA) blended cement mortar. Nine classes of CCA blended cements were employed with the CCA content ranging from 0% to 25%. The 0% CCA replacement involved the use of normal ordinary Portland cement and it served as the control. The mix proportions of cement: sharp sand used were 1:1, 1:2, and 1:3 with water-tobinder ratio ranging between 0.26 and 0.29. Thermal conductivity test was performed using 50 x 50 x 15 mortar cube specimens cast in wooden moulds in pairs. The steady state heating method involving the use of three – blocks of brass was used for conducting the test with a heater made of nichrome wire wound round a ceramic rod. The final temperature difference obtained over a period of continuous heating for eight hours was used in determining the thermal conductivity. The thermal conductivity of CCA-blended cement specimens decreased steadily as the CCA percentage increased. For 1:1 mix proportion; the 0 thermal conductivity decreases from 1.80W/m C 0 to 0.69W/m C when the CCA percentage replacement increases from 2% to 25% as 0 against the control value of 2...
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...Accepted Manuscript Title: Effect of layer thickness on thermal properties of multilayer thin films produced by PVD Authors: B. Tlili, C. Nouveau, M.J. Walock, M. Nasri, T. Gharib PII: DOI: Reference: To appear in: S0042-207X(11)00353-8 10.1016/j.vacuum.2011.09.008 VAC 5485 Vacuum Received Date: 20 February 2011 Revised Date: 5 September 2011 Accepted Date: 18 September 2011 Please cite this article as: Tlili B, Nouveau C, Walock MJ, Nasri M, Gharib T. Effect of layer thickness on thermal properties of multilayer thin films produced by PVD, Vacuum (2011), doi: 10.1016/ j.vacuum.2011.09.008 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. ACCEPTED MANUSCRIPT Effect of layer thickness on thermal properties of multilayer thin films produced by PVD B. Tlilia,b, C. Nouveaub, M J Walockc,a, M. Nasria, dT.Gharib. UR. Mécanique Appliquée, Ingénierie et Industrialisation (M.A.2I), ENIT, BP 37, Le Belvédère, 1002 Tunis, Tunisie b Laboratoire Bourguignon des Matériaux et Procédés (LaBoMaP), Centre Arts et Métiers ParisTech de Cluny, Rue Porte de Paris, F-71250 Cluny...
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...nanoparticles having size of 1–100 nm, which are uniformly and stably suspended in a base fluid. Generally metals or metal-oxides used as Nanoparticles and they greatly enhance the thermal conductivity of the Nano fluids. Nano fluids have been considered for so many industrial applications for advanced heat transfer fluids for two decades. However, due to complexity of the Nano fluid systems, there is no agreement has been achieved in heat transfer processes. Nano fluids have the following advantages: • Nano fluids have broad surface area and more heat transfer rate occurs between particles and base fluids. • High dispersal...
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...Transport Phenomenon (Electrical and Thermal) in two allotropic forms of Carbon (Diamond and Graphite) Graphite and Diamond both are formed from carbon (two allotropic forms of carbon). Though they have similar constituent element, they differ a lot in their properties. Diamond is a good thermal conductor but a bad electrical conductor, while graphite is a bad thermal conductor but a good electrical conductor. This is one example of their property difference. The difference in their properties arises because of different arrangement of carbon atoms present in them. Basic physical and chemical properties of graphite and diamond to highlight their differences are as follows: Differences between Graphite and Diamond Physical Appearance: Graphite is opaque and metallic- to earthy-looking while diamonds are transparent and brilliant. Another important physical difference is their hardness. The hardness of minerals is compared using the Moh's Hardness Scale, a relative scale numbered 1 (softest) to 10 (hardest). Graphite is very soft and has a hardness of 1 to 2 on this scale. Diamonds are the hardest known natural substance and have a hardness of 10. Diamond is used as an abrasive because of its great hardness, whereas graphite is used as a lubricant. Structural Differences: Diamond Space Group Fd3m face-centered cubic Atoms/unit cell 8 Cell volume 45.385 x 10-24cm3 X-ray density 3.5155 g/cm3 {draw:frame} Graphite Space Group C6/mmc; C-centered...
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...HEAT TRANSFER IN ROCKS THERMAL CONDUCTIVITY OF ROCKS Thermal conductivity of a rock (������) is defined as the heat flow across a surface per unit area per unit time when a particular temperature difference exists in a unit length perpendicular to the surface. It depends on following factors:- Chemical composition of the rocks (rocks are aggregates of minerals) 1. Water content of the rock 2. Temperature 3. Pressure 4. Radioactive decay (if any) etc. Thermal conductivity has units of W/(m℃) Heat is transported through a saturated porous medium in a combined mechanism: by conduction through its solid matrix and liquid in its pores as well as by convection of the moving liquid. By applying the law of conservation of energy to a control volume, an equation for heat transfer in the saturated porous medium can be expressed as: ρc∂t∂τ+ ρwcwV·∇t =∇ · (k∇t) (2) where k denotes the effective thermal conductivity of the porous medium; ρc is the volumetric specific heat of the porous medium, including both the solid matrix and water in its pores, ρwcw the volumetric specific heat of water. Note in the equation that heat is stored and conducted through both the water and soil matrix, but only water takes part in convection of heat here. The average linear groundwater velocity V over a cross-section of the medium may be determined by the hydraulic head distribution according to the Darcy’s law if the hydraulic conductivity of the medium is known. The...
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...TASK 1 – PHYSICAL PROPERTIES OF SOME ELEMENTS AND COMPOUNDS | |Test for | | | | |Substances | | | |Electro |Thermal conductivity|Solubility – is it |Melting point? |Boiling point | | |conductivity: does | |soluble in water? | | | | |it conduct | | | | | | |electricity? | | | | | | | | | | | | | |As solids |In solutions | | | | | |Potassium chloride | |Slightly conductive | |__ |7700C |15000C | |Sodium chloride | |Quite | |Soluble |14650C |8010C | | | |Conductive | | |266900F |1473.40F | |HCL | |Slightly conductive | ...
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...h(Ts − T∞ ) (1) where h is the heat transfer coefficient, and Ts is the local surface temperature. The problem is greatly simplified by assuming that the heat flux on the surface is uniform. Under this condition, Ts = T (r0 ) is also uniform and the temperature inside the sphere depends only on the radius, r, and time t, i.e., ∗ Mechanical and Materials Engineering Department, Portland State University, Portland, OR, 97201, gerry@me.pdx.edu † Corrections made 10 September 2011 h T ro Figure 1: A sphere immersed in and exchanging heat with stream of fluid. 1 2 T = T (r, t). The temperature field is governed by the heat equation in spherical coordinates ∂T α∂ 1 ∂T =2 (2) ∂t r ∂r r2 ∂r where α = k/(ρc) is the thermal diffusivity of the sphere material, k is the thermal conductivity, ρ is the density, and c is the specific heat. The boundary condition on the surface is k ∂T ∂r = h(T∞ − Ts ). (3) r =r0 The initial condition is T (r, 0) = Ti . (4) The remaining condition is that the temperature at all points in the sphere is bounded. These three conditions are sufficient to obtain a solution to Equation (2). 2 Analytical Solution The analytical solution for Equation (2), subject to Equation (3), Equation (4), and the condition of bounded T (r, t) is given in several heat transfer...
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...Heat Transfer Course Paper Name Institution Date Introduction To explore and work in space, the astronauts must carry their environment because there is no oxygen and atmospheric pressure to sustain life. The spacesuit is more than clothes an astronaut puts on in space. It’s really a small spacecraft. Its main work is to protect the astronaut when in space. Astronauts needs to put on spacesuits at any time they leave a spacecraft and are exposed to the surrounding space. In space, air to breath and air pressure is not available. Space has dangerous radiation and is extremely cold so without protection, an astronaut would rapidly die in space. The design of spacesuits is such that it protect astronauts from the radiation, cold and low pressure in space and furthermore provide air to breathe. Wearing a spacesuit permits an astronaut to be able survive and work in space. They also keep the astronaut from getting hurt by the space dust. The space dust always travel at a very high speed and may cause hurt to the astronaut. Moreover the suits holds drinking water for the astronaut. The spacesuit is made up of many parts that perform different roles. One of the parts protect the chest, another part covers the arms and connects to gloves and the helmet protects the head. The last part of this suit covers the astronaut’s feet and legs. Other parts of this suits are made up of many layers of material. The layers each performs different roles; some protect the astronaut from space...
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...Available online at www.sciencedirect.com Applied Thermal Engineering 29 (2009) 75–90 www.elsevier.com/locate/apthermeng An axiomatic design approach in development of nanofluid coolants In Cheol Bang a,*, Gyunyoung Heo b b a Energy Sciences, Global Edge Institute, Tokyo Institute of Technology, 2-12-1-S6-13 O-okayama, Meguro-ku, Tokyo 152-8550, Japan Department of Nuclear Engineering, Kyung Hee University, 1 Seocheon-dong, Giheung-gu, Yongin-si, Gyunggi-do 446-701, Republic of Korea Received 4 September 2007; accepted 4 February 2008 Available online 12 February 2008 Abstract The experimental data for nanofluids in thermal-fluid systems have shown that the new fluids promise to become advanced heat transfer fluids in terms of thermal performance. While enhancing thermal characteristics, the solid–liquid mixtures present an unavoidable disadvantage in terms of pumping cost for economic operation of thermal-fluid systems. In addition, there is a lack of agreement between experimental data provided in the literature. The present work found that there would be no comprehensible design strategy in developing nanofluids. In this work, the Axiomatic Design (AD) theory is applied to systemize the design of nanofluids in order to bring its practical use forward. According to the Independence Axiom of the AD theory, the excessive couplings between the functional requirements and the parameters of a nanofluid system prevent from meeting the functional goals of the entire...
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...becoming a primary material of choice. The use of composites in the building industry is growing rapidly. Traditional benefits offered by composites are being recognized and utilized to address design limitations and can be used to reduce life cycle environmental and cost impacts. Learning Objectives • Define ‘Composite Materials’ and learn the history of composites in multiple industries and the factors that led the growth of composites in these industries. • Identify the design and performance attributes of composites used in other industries that are applicable to the building / construction market. • Review case studies that demonstrate how the inherent attributes of composites such as low weight, durability and low thermal conductivity, result in environmental and cost effective material options. • Explore web based education tools that offer case studies on the use of composites in construction and allow users to connect with composite fabricators that specialize in design, fabrication and installation of composite building materials. What is a Composite? Composite An engineered combination of materials that result in a finished material with better overall properties than the starting constituents. At a microscopic level, the constituent materials remain distinct within the finished structure. “Traditional” Composites Wood is a natural composite of cellulose fibers in a lignin matrix. Engineered wood is wood fibers, strands or veneers...
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...(1) (Welty, Rorrer, Foster, 6th Edition International Student Version 16.2) It is desired to transport liquid metal through a pipe embedded in a wall at a point where the temperature is 650K. A 1.2-m thick wall constructed of a material having thermal conductivity varying with temperature according to , where T is in K and k is in W/m.K, has its inside surface maintained at 925 K. The outside surface is exposed to air at 300 K with a convective heat transfer coefficient of 23 W/m2.K. How far from the hot surface should the pipe be located. What is the heat flux for the wall? (2) WWWR 17.13 A 2.5-cm-thick sheet of plastic (k = 2.42 W/m.K) is to be bonded to a 5-cm-thick aluminium plate. The glue that will accomplish the bonding is to be held at a temperature of 325K to achieve the best adherence, and the heat to accomplish this temperature is to be provided by a radiant source. The convective heat transfer coefficient on the surfaces of both the plastic and aluminium is 12 W/m2.K, and the surrounding air is at 295 K. What is the required heat flux if it is applied to the surface of (a) plastic? (b) aluminium? (3) (Modified from Welty, Rorrer, Foster, 6th Edition International Student Version 16.1) The steady state expression for heat conduction through a plane wall is . For steady state heat conduction through a hollow cylinder, an expression similar to the equation is Where is the log-mean are defined as a. Show that as defined above satisfies the equations for...
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...Table of Contents Abstract 2 Introduction 2 The Fire Problem 2 Methodology 5 Results and discussion 6 Processes of flame spread 7 Diffusion flame spread 8 Thermal Model 8 Transition to Turbulence 10 References 13 Abstract The fires problem is one of the hazard pose a threat to life and property. Flames behave differently under various conditions which include: the oxygen available, combustible material, orientation of surfaces, etc. this a complex phenomena which is influenced by multiple factors that includes ignition, heat release rate, flame spread and the generation of different products of combustion like carbon IV oxide and carbon II oxide. The research was performed by studying various sources in the library and in the internet and also performing experiments to simulate a real life situation. Introduction The Fire Problem The flammability of a material is a complex event which is influenced by multiple factors that includes ignition, heat release rate, flame spread and the generation of different products of combustion like carbon IV oxide and carbon II oxide. In order to better protect the people and property from risk posed by the unwanted fires, it become necessary to understands all these factors under different conditions. Babrauskas and Vytenis 1992 suggested that heat release rate is the main variable in fire hazard; but Kashiwagi and Ito argued effectively that, the flame spread over the surface...
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...Benefits of Using Insulated Concrete Forms in Residential Constriction Abstract While technology has changed rapidly within the last decade for cell phones and computers, building construction remains the same as it was 100 years ago. Traditional wood frame structures have insulation problems that cause thermal bridging, through which precious energy is lost. These houses have a low thermal resistance resulting in a low insulation value. There is a more efficient way to build a house: using insulated concrete forms (ICF). Despite that technology had been present in the market for a long time, people are reluctant to use ICFs because of higher cost. An ICF structure is an amazing shelter in a natural disaster. The rebuilding cost of an ICF structure is far less than that of a typical structure. In an effort to become more environmentally friendly, we must explore alternative building techniques. This paper discusses how the significance of the long term energy savings, durability and fire resistance of ICFs offset the short term high cost of construction. Benefits of Using Insulated Concrete Forms in Residential Constriction Living in the 21st century makes people more aware of emerging technologies. The telephone is no longer just a communication device; it provides users with all kinds of information from changing global interests to the latest fashion trends. It has become near impossible to live without the assistance of computers, electronics, gadgets and appliances...
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