The document discusses phase rule and its application to a one component water system. It defines phase rule and explains how it can be applied to determine the degrees of freedom in a water system containing solid, liquid, and gas phases of water. The key points are:
1) Phase rule relates the number of phases (P), components (C), and degrees of freedom (F) as F = C - P + 2.
2) In a one component water system, degrees of freedom can be 0, 1, or 2 depending on whether there are 3, 2, or 1 phases present respectively.
3) The phase diagram of a water system shows boundary curves where two phases coexist and areas where a
Proton Exchange Membrane Fuel Cells (PEMFC) are promising contender as the next generation energy source because of their striking features including high energy density, low operating temperature, easy scale up and zero environmental pollution.
This ppt explains basics of corrosion, its significance, Mechanism of electrochemical and chemical corrosion, Cathodic protection, Anodic protection, Sacrificial protection, Galvanization, Concentration Corrosion, Pitting Corrosion and also describe about the prevention and control of corrosion with respect to protective coatings and modification in design.
DESIGN AND FABRICATION OF HELICAL TUBE IN COIL TYPE HEAT EXCHANGERhemantnehete
Heat exchangers are the important engineering systems with wide variety of applications including power plants, nuclear reactors, refrigeration and air-conditioning systems, heat recovery systems, chemical processing and food industries. Helical coil configuration is very effective for heat exchangers and chemical reactors because they can accommodate a large heat transfer area in a small space, with high heat transfer coefficients. This project focus on an increase in the effectiveness of a heat exchanger and analysis of various parameters that affect the effectiveness of a heat exchanger and also deals with the performance analysis of heat exchanger by varying various parameters like number of coils, flow rate and temperature. The results of the helical tube heat exchanger are compared with the straight tube heat exchanger in both parallel and counter flow by varying parameters like temperature, flow rate of cold water and number of turns of helical coil.
This presentation describes all the steps included in the process to refine copper metal from its ore. All the steps are described briefly with the help of chemical equations.
THE PHASE RULE
phase rule
degree of freedom in mixture
one component system
two component system
pressure temperature diagram sulfur hydrogen
eutectic eutectoid mixture
Proton Exchange Membrane Fuel Cells (PEMFC) are promising contender as the next generation energy source because of their striking features including high energy density, low operating temperature, easy scale up and zero environmental pollution.
This ppt explains basics of corrosion, its significance, Mechanism of electrochemical and chemical corrosion, Cathodic protection, Anodic protection, Sacrificial protection, Galvanization, Concentration Corrosion, Pitting Corrosion and also describe about the prevention and control of corrosion with respect to protective coatings and modification in design.
DESIGN AND FABRICATION OF HELICAL TUBE IN COIL TYPE HEAT EXCHANGERhemantnehete
Heat exchangers are the important engineering systems with wide variety of applications including power plants, nuclear reactors, refrigeration and air-conditioning systems, heat recovery systems, chemical processing and food industries. Helical coil configuration is very effective for heat exchangers and chemical reactors because they can accommodate a large heat transfer area in a small space, with high heat transfer coefficients. This project focus on an increase in the effectiveness of a heat exchanger and analysis of various parameters that affect the effectiveness of a heat exchanger and also deals with the performance analysis of heat exchanger by varying various parameters like number of coils, flow rate and temperature. The results of the helical tube heat exchanger are compared with the straight tube heat exchanger in both parallel and counter flow by varying parameters like temperature, flow rate of cold water and number of turns of helical coil.
This presentation describes all the steps included in the process to refine copper metal from its ore. All the steps are described briefly with the help of chemical equations.
THE PHASE RULE
phase rule
degree of freedom in mixture
one component system
two component system
pressure temperature diagram sulfur hydrogen
eutectic eutectoid mixture
Infomatica, as it stands today, is a manifestation of our values, toil, and dedication towards imparting knowledge to the pupils of the society. Visit us: http://www.infomaticaacademy.com/
Phase equilibria: phase, components and degrees of freedom. The phase rule and its
thermodynamic derivation. The phase diagrams of water and sulphur systems, partially
miscible liquid pairs: the phenol and water and nicotine-water systems. Completely
miscible liquid pairs and their separation by fractional distillation. Freeze drying
(lyophilization).
Presentation suitable mainly for Engineering Students
Highlights: Phase Rule Derivation, Cooling curves, Phase Diagram of water, Carbon dioxide, lead-Silver system, zinc-magnesium system and sodium sulphate-water system
Mechanical Engineering is the Branch of Engineering.The mechanical engineering field requires an understanding of core areas including mechanics, dynamics, thermodynamics, materials science and structural analysis,Fluid Mechanics, Metrology and Instrumentation, Dynamics of Machinery- II, Manufacturing Processes II, Industrial Drafting and Machine Design, Engineering Graphics, Power Plant Engineering. Ekeeda offers Online Mechanical Engineering Courses for all the Subjects as per the Syllabus. Visit us: https://ekeeda.com/streamdetails/stream/mechanical-engineering
Ekeeda Provides Online Video Lectures for Mechanical Engineering Degree Subject Courses for All Engineering Universities. Visit us: https://ekeeda.com/streamdetails/stream/mechanical-engineering
Ekeeda Provides Online Video Lectures for Mechanical Engineering Degree Subject Courses for All Engineering Universities. Visit us: https://ekeeda.com/streamdetails/stream/mechanical-engineering
Civil Engineering is the Branch of Engineering.The Civil engineering field requires an understanding of core areas including Mechanics of Solids, Structural Mechanics - I, Building Construction Materials, Surveying - I, Geology and Geotechnical Engineering, Structural Mechanics, Building Construction, Water Resources and Irrigation, Environmental Engineering, Transportation Engineering, Construction and Project Management. Ekeeda offers Online Mechanical Engineering Courses for all the Subjects as per the Syllabus Visit us: https://ekeeda.com/streamdetails/stream/civil-engineering
Civil Engineering is the Branch of Engineering.The Civil engineering field requires an understanding of core areas including Mechanics of Solids, Structural Mechanics - I, Building Construction Materials, Surveying - I, Geology and Geotechnical Engineering, Structural Mechanics, Building Construction, Water Resources and Irrigation, Environmental Engineering, Transportation Engineering, Construction and Project Management. Ekeeda offers Online Mechanical Engineering Courses for all the Subjects as per the Syllabus Visit us: https://ekeeda.com/streamdetails/stream/civil-engineering
Ekeeda Provides Online Video Lectures for Civil Engineering Degree Subject Courses for All Engineering Universities. Visit us: https://ekeeda.com/streamdetails/stream/civil-engineering
Ekeeda Provides Online Video Lectures for Civil Engineering Degree Subject Courses for All Engineering Universities. Visit us: https://ekeeda.com/streamdetails/stream/civil-engineering
Kinetics of particles impulse momentum methodEkeeda
Ekeeda Provides Online Video Lectures for Civil Engineering Degree Subject Courses for All Engineering Universities. Visit us: https://ekeeda.com/streamdetails/stream/civil-engineering
Learn Online Courses of Subject Introduction to Civil Engineering and Engineering Mechanics. Clear the Concepts of Introduction to Civil Engineering and Engineering Mechanics Through Video Lectures and PDF Notes. Visit us: https://ekeeda.com/streamdetails/subject/introduction-to-civil-engineering-and-engineering-mechanics
Learn Online Courses of Subject Introduction to Civil Engineering and Engineering Mechanics. Clear the Concepts of Introduction to Civil Engineering and Engineering Mechanics Through Video Lectures and PDF Notes. Visit us: https://ekeeda.com/streamdetails/subject/introduction-to-civil-engineering-and-engineering-mechanics
Ekeeda Provides Online Video Lectures for Civil Engineering Degree Subject Courses for All Engineering Universities. Visit us: https://ekeeda.com/streamdetails/stream/civil-engineering
Coplanar forces res & comp of forces - for mergeEkeeda
Ekeeda Provides Online Video Lectures for Civil Engineering Degree Subject Courses for All Engineering Universities. Visit us: https://ekeeda.com/streamdetails/stream/civil-engineering
Ekeeda Provides Online Video Lectures for Civil Engineering Degree Subject Courses for All Engineering Universities. Visit us: https://ekeeda.com/streamdetails/stream/civil-engineering
Ekeeda Provides Online Video Lectures for Civil Engineering Degree Subject Courses for All Engineering Universities. Visit us: https://ekeeda.com/streamdetails/stream/civil-engineering
Infomatica, as it stands today, is a manifestation of our values, toil, and dedication towards imparting knowledge to the pupils of the society. Visit us: http://www.infomaticaacademy.com/
Infomatica, as it stands today, is a manifestation of our values, toil, and dedication towards imparting knowledge to the pupils of the society. Visit us/l http://www.infomaticaacademy.com/
Infomatica, as it stands today, is a manifestation of our values, toil, and dedication towards imparting knowledge to the pupils of the society. Visit us: http://www.infomaticaacademy.com/
Infomatica, as it stands today, is a manifestation of our values, toil, and dedication towards imparting knowledge to the pupils of the society. Visit us: http://www.infomaticaacademy.com/
Ekeeda Provides Online Engineering Subjects Video Lectures and Tutorials of Mumbai University (MU) Courses. Visit us: https://ekeeda.com/streamdetails/University/Mumbai-University
Ekeeda Provides Online Engineering Subjects Video Lectures and Tutorials of Mumbai University (MU) Courses. Visit us: https://ekeeda.com/streamdetails/University/Mumbai-University
Automobile Management System Project Report.pdfKamal Acharya
The proposed project is developed to manage the automobile in the automobile dealer company. The main module in this project is login, automobile management, customer management, sales, complaints and reports. The first module is the login. The automobile showroom owner should login to the project for usage. The username and password are verified and if it is correct, next form opens. If the username and password are not correct, it shows the error message.
When a customer search for a automobile, if the automobile is available, they will be taken to a page that shows the details of the automobile including automobile name, automobile ID, quantity, price etc. “Automobile Management System” is useful for maintaining automobiles, customers effectively and hence helps for establishing good relation between customer and automobile organization. It contains various customized modules for effectively maintaining automobiles and stock information accurately and safely.
When the automobile is sold to the customer, stock will be reduced automatically. When a new purchase is made, stock will be increased automatically. While selecting automobiles for sale, the proposed software will automatically check for total number of available stock of that particular item, if the total stock of that particular item is less than 5, software will notify the user to purchase the particular item.
Also when the user tries to sale items which are not in stock, the system will prompt the user that the stock is not enough. Customers of this system can search for a automobile; can purchase a automobile easily by selecting fast. On the other hand the stock of automobiles can be maintained perfectly by the automobile shop manager overcoming the drawbacks of existing system.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
Forklift Classes Overview by Intella PartsIntella Parts
Discover the different forklift classes and their specific applications. Learn how to choose the right forklift for your needs to ensure safety, efficiency, and compliance in your operations.
For more technical information, visit our website https://intellaparts.com
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Democratizing Fuzzing at Scale by Abhishek Aryaabh.arya
Presented at NUS: Fuzzing and Software Security Summer School 2024
This keynote talks about the democratization of fuzzing at scale, highlighting the collaboration between open source communities, academia, and industry to advance the field of fuzzing. It delves into the history of fuzzing, the development of scalable fuzzing platforms, and the empowerment of community-driven research. The talk will further discuss recent advancements leveraging AI/ML and offer insights into the future evolution of the fuzzing landscape.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...
5 phase rule and steels
1. CHAPTER 5 : Phase Rule and Steels
Give the demerits of phase rule.
Ans. : Demerits of Phase Rule
1.Phase rule can be applied for systems in equilibrium only.
2.It is not of much help in case of systems which attain the equilibrium state very slowly.
3.It applies only to a single equilibrium state. It does not indicate the other possible equilibria in the system.
4.Phase rule considers only the number of phases but not their quantities. Even a minute quantity of the phase,
when present, accounts towards the number of phases. Hence, care has to be taken in deciding the number of
phases existing in the equilibrium state.
5.All the phases of the system must be present under the same conditions of temperature, pressure and
gravitational forces.
6.The solid, liquid phases should not be so finely sub-divided as to bring about deviation from their normal
values of vapour pressure.
State and explain phase rule. Discuss the application of phase rule to one component water system.
(7 Marks)
Ans. : Gibb's Phase rule may be stated as, "provided equilibrium between any number of phases is not
influenced by gravitational, electric or magnetic forces or by surface action, but only by temperature, pressure
and concentration, then the number of degrees of freedom (F) of the system is related to the number of
components (C) and phases (P) by; the phase rule equation.
F = C – P + 2
for any system at equilibrium at definite temperature and pressure." This rule does not have an exception, if
applied properly b:y maintaining the variables at a fixed levels.
Water System
The water system under normal condition is of three phases and one component system. The system
involved three phases are solid - ice, liquid - water, and gas - water vapour. All these phases can be represented
by one chemical entity H20, hence it is one component system.
Let us apply the phase rule to one component, i.e. water system. Substitute the value of component (C) = 1, in
the phase rule equation, then the equation is
F = C – P + 2
F = 1 – P + 2
F = 3 – P
From the above value of degree of freedom (F), we can say that, the degree of freedom (F) depends on
the number of phases present at the equilibrium.
Therefore, the following three different cases are possible, (Explained with the help of phase diagram,
refer Fig.).
Hence when,
P = 1, then F = 2 …… system is Bivariant
2. P = 2, then F = 1 …… system is Monovariant
P = 3, then F = 0 …… system is zero variant
From the above equation it is clear that, for arty one component system, the maximum number of
degree of freedom is two and most convenient variables are pressure and temperature. In the above phase
diagram of water system following salient features are observed:
1. The curves OA, OB and OC.
2. The areas AOC, AOB and BOC. 3.
3. The triple point '0' and
4. The metastable curve. (OA/
)
1. The curves OA, OB and OC
These three curves meet at the point '0' (called as tripple point) and divide the diagram in to three areas.
Therefore, these three curves ar1 known as boundary lines.
Curve OA (Vapour Pressure Curve)
The curve OA terminates at A, the critical point 218 atm. and 3740
temperature. It represents the vapour
pressure of liquid water at different temperatures. The two phases water and water vapour coexist in equilibrium
along this curve. Here, are two phases (P = 2) and one component (C = 1), therefore
F = 1 – 2 + 2 = 1
Hence, system is monovariant or univariant or having one degree of freedom. When the vapour pressure
is equal to one atmosphere, the corresponding temperature C as shown in figure is the boiling point of water, i.e.
100 C
Curve OB (Sublimation curve)
The curve OB terminates at B, the absolute zero, Le. - 2730
temperature. It shows the vapour pressure of
solid ice at different temperature
The two phases solid-ice and water-vapour coexist in equilibrium along this curve. Therefore, degree of
freedom for this system is also one and system is monovarient.
Curve OC (Fusion curve)
The curve OC terminates at C, the critical pressure. The two phases solid-ice and liquid-water coexist in
equilibrium.
This curve indicates that the melting point of ice decreases with increase of pressure.
The one atmosphere (1.0 atm.) line meets the fusion (freezing/melting) curve at O°C which is the normal
melting point of ice. Again, along the curve OC, there are two phases in equilibrium and system is of one
component.
Therefore, the system is monovarient.
From the above discussion, we can say that, along the curves OA, OB and OC there are two phases in
equilibrium and one component. Therefore,
F = C – P + 2
F = 1 – 2 + 2
F = 1
Hence, each two phases system has one degree of freedom, i.e. system is univarient or monovarient.
2. The areas AOC, AOB and BOC
The regions or areas between the curves show the conditions of temperature and pressure under which a
single phase, i.e. ice, water or water vapour is capable of stable existence. Thus
1. Area AOC represents conditions for liquid phase, i.e. water.
2. Area AOB represents conditions for gaseous phase, i.e. water vapour.
3. Area BOC represents conditions for solid phase, i.e. ice.
In all the three areas, there being 'one phase' and 'one component'.
Therefore,
F = C – P + 2
F = 1 – 1 + 2
F = 2
Hence, each system has two degree of freedom, i.e. system is bivarient or divarient.
3. Triple point
All the three curves, OA, OB and OC meet at the point 0 called as tripple point, where all the three
phases solid, liquid and vapour are simultaneously in equilibrium.
This triple point occurs at O.0075°C and 4.58 mm Hg pressure. Since, there are three phases and one
component, therefore
3. F = C – P + 2
F = 1 – 3 + 2
F = 0
The system at tripple point is zero variant or nonvariant. Thus, neither pressure nor temperature can be
altered.
Even slightly changed three phases would not exist if one of the phase disappears.
4. Metastable curve (curve OA’)
This curve is also known as supercooling (water/vapour) curve. This is the extension of curve OA, i.e.
vapour pressure curve. That is water can be supercooled by eliminating solid particles carefully which includes
crystallization.
The supercooled water system is unstable, i.e. metastable. It at once reverts to the stable system ice or
vapour on the slightest disturbance.
The metastable vapour pressure of super cooled water is higher than vapour pressure of ice.
What are alloys steels?
What are the effects of following alloying elements on alloy steels :
(i) Nickel
(ii) Chromium
(iii) Cobalt
(iv) Tungsten
Ans. : Metals possess many useful properties, such as high malleability, ductility, luster, good electrical
conductivity being a few to mention. But, in nature metals are not available in pure state.
When metals are extracted from their natural sources - i.e. minerals or ores, some impurities are
carried along with the pure metals.
Hence, to get pure metal, further purification has to be done by various different methods. But after all
this processing, the pure metal obtained from its ore, loses some vital characteristics and becomes practically
useless for engineering purposes.
Some of such characteristics are, its tensile strength, corrosion resistance and hardness.
The pure metals are very soft, highly chemically reactive, highly malleable and ductile. Thus changes
in these vital properties, reduce shock and wear resistance of metals. The high chemical reactivity makes pure
metal susceptible to corrosion.
The properties of pure metals can be improved by alloying the pure metal with another suitable
meta/non-metal, e.g. iron in pure state can be alloyed to get steel, which shows the desired properties such as
hardness, toughness, high corrosion resistance etc. Here, steel is an alloy of iron with carbon (non-metal),
chromium/manganese (metals) etc.
An alloy is a solid mixture of two or more metals or non-metals. Alloy must have necessarily,
(i) at least one metal (base metal)
(ii) at least one additional metal or non-metal.
Element Special effects
ChromiumEnhance hardenability, corrosion and oxidation resistance, increase high temperature strength. In
high carbon steels, it increases abrasion resistance.
Cobalt Contributes to hardness of steel.
Nickel Along with other elements, renders moderate to high hardenability ; enhance strength of
unhardened steels by solid solution effect ; enhances toughness in pearlitic – ferritic steels.
Tungsten It helps to form hard and abrasion resisting carbide film in tool steels.
Imparts high temperature hardness in tempered steels.
It enhances creep strength in some high temperature steels.
What is triple point in phase diagram? Explain it with reference to one component water system phase
diagram.
4. All the three curves, OA, OB and OC meet at the point 0 called as tripple point, where all the three
phases solid, liquid and vapour are simultaneously in equilibrium. This triple point occurs at 0.0075°C and
4.58 mm Hg pressure. Since, there are three phases and one component, therefore
F = C – P + 2
F = 1 – 3 + 2
F = 0
The system at tripple point is zero variant or nonvariant. Thus, neither pressure nor temperature can
be altered. Even slightly changed three phases would not exist if one of the phase disappears.
Explain any two of the following terms :
1. Phase
2. Components
3. Degrees of freedom
Ans. :
(1) Phase
A phase is defined as any homogeneous, physically distinct and mechanically separable portion of a
system, which is separated from other such parts of the system by definite boundary surfaces.
Examples
1. In water. system, at freezing point of water, an equilibrium exists where ice, water and water vapours
are the three phases, each of which is physically distinct and homogeneous, and with definite boundaries
between ice, water and water vapours, as,
2. All gases mix freely to form homogeneous mixtures. Therefore, any mixture of gases, say and and
forms one phase only.
3. Two completely miscible liquids yield an uniform solution. Thus, a solution of alcohol and water is a one
phase system.
(2) Components
Definition
The term component is defined as, "the smallest number of independently variable constituents
taking part in the state of equilibrium by means of which the composition of each phase can be expressed
directly or in the form of chemical equation".
Examples
1. In water system, we have three phases, i.e. ice (Solid), water (Liquid) and water vapour (Gaseous) in
equilibrium. Each of these phases are different physical forms of the same chemical substance, i.e. H20. Hence,
system is regarded one component system.
2. In sulphur system, there are four phases, Le. rhombic sulphur, monoclinic sulphur, liquid sulphur and sulphur
5. vapour. The composition of all four phases can be expressed by one chemical individual sulphur (S). Hence,
sulphur system is regarded as one component system.
3. When calcium carbonate is heated in a closed vessel, the following reaction takes place.
Degree of Freedom (Variance)
Definition
Term degree of freedom is defined as, "the minimum number of independently variable factors such as
temperature, pressure and composition of the phases which must be arbitrarily specified in order to represent
perfectly the condition of a system".
Examples
In case of water system :
(a) If all' the three phases are in equilibrium, then no condition need to be specified because the three phases can
be in equilibrium only at particular temperature and pressure,
The system is no degree of freedom or invariant or zero variant or non-variant.
(b) If condition like temperature or pressure in altered, three phases will not remain in equilibrium and one of the
phase disappears.
For the following system :
We must state either the temperature or pressure to define it completely. Hence, the degree
of freedom is one or system univariant. ,
(c) For a system consisting of water in vapour phase only we must state the values of both, the temperature and
pressure in order to 'describe the system completely. Hence, the system has two degree of freedom or system is
bivariant.
State and explain condensed phase rule. (3 Marks)
Ans. : Condensed or Reduced Phase Rule
When a single phase is present in a two component system, then the degree of freedom (F) is represented
by following equations;
F = C – P + 2
F = 2 – 1 + 2
F = 3
From the values of F (F = 3) we can say that, three variables must be specified in order to describe the
condition of phase, i.e. in addition to temperature and pressure the concentration of one of the component has to be
given.
What are plain carbon steels? How can they be classified on the basis of carbon contents?
(3 Marks)
Ans. :
The alloys of iron with other metal (s) or/and non-metal are known as ferrous alloys. These are commonly
known as alloy steels. The metal iron generally forms alloys by mixing with carbon, and any other element (metal)
such as either nickel alone or nickel and chromium both. Based on this, the alloy of iron and carbon (i.e. steels -
widely known as plain carbon steels) are either,
(a) Three components i.e. (Fe, C, Ni)
or (b) Four components i.e. (Fe, C, Ni, Cr)
Since these 'steels essentially contain iron and carbon, are known as plain carbon steels. The percentage of
carbon in steels ranges from 0.008% to 2%. The plain carbon steels are further classified/named on the basis of its
carbon content as,