Tiếng Anh Chuyên Ngành Thủy Lợi

Tiếng Anh Chuyên Ngành Thủy Lợi

'-7 306 TRUONG 1l.;.I HQC THiN LQI

A-BQ M6N TItNG ANH

TIENGANH

ENGLISH FOR WATER RESOURCES

(The second edition)

•

MVCLVC

Ti€ng Anh ngay cang dm;ycsir d\lng re)ng rai tren toan th~ gim, d~c bi~t la trong linh V\l'Ckhoa hQc k)' thu~t Thliy 19i Vi v~y, d6i vm cac k)' su, sinh vien Thliy 19i thi ti€ng Anhchuyen nganh th\fc S\f la cful thi€t trong cong vi~c Xullt pMt tir nhu cAu tren, Be) mon Ti€ngAnh thlly cful thi€t pMi xay d\fng me)t t~p hai giang nhfun ph\lc Y\I cho nhiing d6i tuc;mgnay.T~p hai giang ra diJi gop phfrn trang bi cho nguiJi hQc v6n til V\fng co bim trong linhV\fCThliy 19i noi chung, gilip hQ n~m duqc cach sir d\lng cac thu~t ngfr chuyen nganh tren

co sa cling c6 cac vlln de ngfr pMp co han lien quan den mili hai dQc Qua day, hQ co th€ coduqc nhfrng kMi ni~m ve cac thu~t ngfr lien quan den chuyen nganh, co kha nmg dQc hi~u

va djch duqc cac tai li~u, sac~, t(lP c~i "\hUy Iqi, d6ng thOi hQ co th€ lam vi~c tT\fCti€p vmcac chuyen gia nuac ngoai de co the tiep c~n duqc vai nhiing thanh l\fu mm clia tien be)khoa hQc k)' thu~t

T~p hai giang g6m 6 bai dQc ve chuyen nganh Thliy lqi duqc bien sO(ln cho d6i tuc;mg

sinh vien hQc mon TA3 t(li tmang D(li hQc Thliy 19i Cac bai dQc duqc suu t~p til cac cu6ngiao trinh kMc nhau, til cac cu6n sach ph6 bien ve chuyen nllanh Thliy 19i Sau mili hai dQCcac thfry, co giao trong Be) mon Ti~ng Anh da xay d\fng h~ thOng hai ~p rllt da d(lng va phongphu d€ ki€m tra, cling c6 cac ki~n thirc ve tir V\fng, ngfr pMp va cach sir d\lng cac thu~t ngfr dahQc trong tling linh V\l'CC\l th€ Cac hinh iinh minh hQa di kern lam cho t~p bai giang themsinh de)ng Cu6i cung Ia h~ th6ng cac thu~t ngfr va til V\fng duqc djch sang ti~ng Vi~t d~ gilipcac em co th€ hi€u cac hai dQc me)t cach d~ dang va nhanh chong han

Be) mon Ti~ng Anh xin tran trQng cam an Ban Giiim hi~u, Trung !fun Thu vi~n dil1(10

dieu ki~n thu~ 19i va cac d6ng nghi~p dil ce)ng tac tich C\fCtrong qua trinh bien SO(lnd€ ~pbai giang nay sam ra dOi ph\lc Y\I kip thOi cho b(ln dQc

Hy ":Qng cu6n giao trinh "Ti€n~ Anh chuyen nganh ThUy lQi" se gi~p cac em sinh

vien hQCtot, nang cao ky nmg dQc hieu cac tai li~u chuyen ngiinh Thliy 19i bmg tieng Anh,nang cao kha nmg sir d\lng ti€ng Anh clia minh trong linh V\fCThliy 19i

Rllt mong nh~ duqc nhieu dong gop quy bau clia b(ln dQc gful xa

Chlic cac b(ln thiinh cong!

Bi} mon Ti€ng Anh

5

UNIT 1: WHAT IS WATER RESOURCES MANAGEMENT?

management differently To the ecologist, water resources management is often connectedwith reversing the effects of the deterioration of ecosystems, land degradation, pollution anddestruction of wetlands To the water engineer, water resources management is about dams,reservoirs, flood protection, diversions, river training, water treatment and reclamation To thelawyer, the main issues in water resources management are the ownership of water, systems

of water rights, the priority of use, water markets, water legislation, and international waterlaw To the economist, water resources management is connected with economic efficiency,cost recovery and the attainment of national objectives It can be truly said that the WaterResources Management, in all its components, is a multi-disciplinary field

In recent years, a number of concepts related to water resources are widely used, such asWater Resources Development, Water Recourses Planning, Water Recourses Management,and more recently, Integrated Water Resources Management It is useful to define theseterms, or at least agree on some broad definitions so that those involved in this work have acommon understanding of their meaning

Water Resources Development: actions, mostly physical, that lead to the beneficial use

of water resources for single or multiple purposes

Water Resources Planning: planning of the development, conservation and allocation of ascarce resource (sectoral and intersectoral), matching water availability and demand, taking intoaccount the full set of national objectives and constraints and the interests of stakeholders

Water Resources Management: the whole set of technical, institutional, managerial andoperational activities required to plan, operate and manage water resources In other words,Water Resources Management can be considered as a process, including all activities onplanning, design, construction and operation of water resources systems

In recent years, definition of the integrated water resources management has been used.Integrated Water Resources Management takes accounts of: I all natural aspects of the waterresources; 2 all sectoral interests and stakeholders; 3 the spatial variation of resources anddemands; 4 relevant policy frameworks (national objectives and constraints); and 5.institutional levels

In order to have effective water resources management, the following principles arerequired:

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• National water resources management should be undertaken in a holistic, determinedand sustained manner to meet national development goals and protect the environment.

• Management of specific water resources should be decentralized to an appropriatelevel responding to basin boundaries

accountable public, private or co-operative agencies providing measured waterservices in a defined geographical area to their customers, and/or members, forappropriate fee

• Water use in society should be sustainable - with incentives, regulatory controls andpublic education promoting economic efficiency, conservation of water resources andprotection of the environment - with a transparent policy framework:

• ~hared water resources within and between nations should be allocated efficiently forthe mutual benefit of all riparian users

The integrated water resources management will be an effective tool to implement theabove principles

I Passive voice:

- In the present simple:

BE +P/I (past participle)

E.g: Water resources management is defined differently

E.g: A lot of hydroelectric power plants have been built in Vietnam

E.g: + Shared water resources should be allocated efficiently for the mutual benefit

of all riparian users

+ Water resources management can be viewed differently

II Infinitives

- Infinitives are used to express purpose. They answer the question why ?

E.g: A number of hydroelectric power plants have been built to meet the energydemand

- Infinitives are used after certain adjectives.

E.g: It is useful to define the terms related to water resources management

We come here to learn English.

We must eat in order to live.

They went early so that they could get good seats.

I Answer the following questions

I What is the view of ecologists on water resources management (WRM)?

2 What is the view of water engineers on WRM?

3 What are the concepts related to water resources?

4 What do these terms mean? Match the term with its definition

I Water Resources Development a a process involving all activities of planning, designing,

constructing and operating water resources systems

2 Water Resources Planning b actions resulting in beneficial use of water resources

for one or more purposes

resource; to match availability and demand; to considerall the national objectives and constraints and theinterests of stakeholders

5 What are the contents of the integrated WRM?

6 How many principles are required to have effective WRM?

II True, false Correct the false ones

I People from different professional backgrounds have the same view on WRM

2 To the water engineer, WRM is about dams, reservoirs, flood protection, diversions, rivertraining, water treatment and reclamation

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3 Water Resources Development: actions that result in the beneficial use of water resourcesfor only one purpose.

4 It is said that WRM involves planning, design, construction, operation of water resourcessystems

5 The government should decentralize management of specific water resources to anappropriate level responding to basin boundaries

6 In order to meet national development goals and protect the environment, we shouldundertake water resources management determinedly and sustainably, holistically

C PRACTICE

I Translate the text into Vietnamese

II Word formation:

I Write the other parts of speech of the words below:

2 Fill in tile blank witll tile words above.

and 0 •••.•• of water resources systems

of water use

III Match a word in column A with an explanation in column n

\ reclaim a to put something into effect; to carry out something

2 objective b suitable; acceptable

3 integrated c to transfer power from central government to local government

4 attain d distribution of something to somebody for a special purpose

5 allocation e to make land fit for farming, ego by bringing water to it or draining it

6 decentralize f all the animals and plants in an area, and their relationship to each

other and their environment

7 ecosystem g rules; general, scientific laws shown in a way a thing works

8 appropriate h purpose, goal, something aimed at

9 principles i to succeed in getting something, esp with effort

10 implement j with various parts or aspects linked closely together

IV Make the sentences passive

I People from different professional backgrounds can view water resources managementdifferently

2 The government should decentralize the managemeqt of specific water resources to anappropriate level

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3 Activities on land pollute rivers, streams and seas.

4 People have used the concept "Integrated water resources management" recently

5 The government should pass some laws to help protect our environment

Water is essential for all forms oflife, but for human beings, it is particularly important.

We can not exist without drinking water, particularly needing clean water to drink; it is vitalfor growing vegetables and other crops; as well as for cooking, bathing, washing and forsanitation Industry also relies on water as a raw material for manufacturing and forgenerating hydroelectricity through water power Furthermore, rivers are used to diluteindustrial and domestic wastes As societies become more industrialized, demand for watercontinues to grow, yet water is natural resources, and its supply is fixed Hydrologist works

resources, including planning for extreme events such as floods and droughts

As a branch of geophysics, hydrology has the objective of measuring and understandingthe physical and chemical processes which control the movement of water through the watercycle It includes the study of water's interaction with both the natural environment and withhuman activities Hydrologists are concerned primarily with water movement within the landphase of the water cycle, yet this represents only 0.6 percent of the world's water; 2.1 percent of

it is locked up in glaciers and sheets, and 97.3 percent is held in the oceans Hydrologyoverlaps with the scientific study of water in oceans and atmosphere, but these are primarily theresponsibility of oceanography and meteorology However, considerable overlap also existswith other sciences, including geology, physics, chemistry, ecology, and biology, becausehydrology is concerned not just with the quantity of water in rivers, but also its quality

Rainfall and river flow are both unevenly distributed in space and time, and this affectsthe availability of water resources In Britain, the heaviest rainfalls occur in the hilly regions

of Wales, the Lake District, and the Highlands of Scotland, yet the greatest population density

is in the central and south-eastern counties, where rainfall, and hence river flows, are lowest

On a worldwide scale, imbalances in spatial run-off are even greater Temporal differencesalso cause significant problems, with availability of water in rivers being least in the driersummer months, when demand for water supply is greatest for watering gardens and forirrigation Hydrologists work with engineers to counteract these spatial and temporalimbalances through design and construction of reservoirs and water transfers, such as the

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aqueducts transferring water from the Lake District to Manchester, or from the Welshmountains to Birmingham.

Hydrology developed originally as a branch of civil engineering, with most effortsgoing into provisions of reliable, clean water supplies to rapidly growing urban centers.Further developments in hydrology helped engineers to design the major irrigation schemes ofIndia, Africa, and the Southeast Asia, and water- power schemes through out the world.However, hydrology has now developed into a major science in its own right, concentrating

on the study of all aspects of the distribution and behaviour of water on the land, withincreasing emphasis on water quality and ecological aspects of water

Hydrology is used to predict the likely effect of natural or artificial changes to riversand groundwater flows Thus, converting farmland to roads or factories reduces infiltration,and hence produces more rapid run-off of rainfall into rivers and increases flooding Whenforests are cleared to grow crops, there is again more rapid run-off, and hence less recharge ofsoil and groundwater stores, which sustains river flows during dry periods Similarly, globalwarming, a consequence of the release of greenhouse gases into the atmosphere, is producingclimatic changes which have an effect on rainfall, and hence run-off patterns Hydrologistswork with climatologists to assess the impact of these anticipated changes by developingmathematical models of rivers basins, by using their knowledge of the individual processeswithin the natural water cycle These numerical models are used to predict the impact ofchanges of land use, or climate, on rivers and aquifer flows, and hence on water resources.Although water has such a great impact on all aspects of life on earth, it is too oftentaken for granted in developed countries, where people tend to be most aware of it only duringextreme events such as droughts and floods, and where a lot of water is often wasted - even indrier areas In developing countries, however, many thousands of people died each year fromevents such as floods and famines induced by droughts Hydrology has a vital role to play inhelping to alleviate problems associated with these extreme conditions, and in planning thedevelopment and management of the world's limited freshwater resources

I Form:

II Uses

BE +PII (Past participle)

1 When the agent of the action is unknown:

Ex: My wallet was stolen last night (We don't know who stole the wallet)

2 When the agent is unimportant:

Ex: The new students' centre was eompleted last week

3 When the agent of the action is obvious from the context:

Ex: I was born in March of 5 (Everyone knows that it was my mother bore me then)

4 To emphasize (put importance on) the recipient (receiver) of the action:

Ex: Only Jane was injured in the accident

5 To connect ideas in different clauses more clearly:

Ex: Pharmacologists would like to study the natural 'pharmacy' known as the rainforest, ifthis can be done before clear-cutting destroys it

6 To make generic statements, announcements, and explanations:

Ex: Something should be done about the traffic jams in this town

I Answer the following questions

I What does hydrology study in general? As a branch of geophysics? As a branch of civilengineering?

2 What is included in the task of hydrologists?

3 What is primary concern that is taken by hydrologists?

4 Does hydrology study what is covered in other sciences? Why?

5 What proves that hydrology has now developed into a major science?

6 Who do hydrologists cooperate with to assess the global warming, climate changes, etc?

7 Which role does the hydrology play?

II Decide if the following statements are True or False

I Hydrology is a science that studies all aspects of water movement only on the surface of theearth

2 If hydrology is considered as a part of geophysics, it will also study water's interaction withboth the natural environment and with human activities

3 Hydrology doesn't have any relation with other sciences such as geology, physics,chemistry, ecology and biology

4 Hydrology always gives exact prediction on the effects of natural or artificial changes toriver and groundwater flows

5 Global warming which is produced by green house gases into the atmosphere is also one ofreasons for climatic changes

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6 Hydrology plays a crucial role in helping to alleviate problems associated with theseextreme conditions and in planning the development and management of the world's limitedfreshwater resources.

III. Choose the best answer

I Water's importance mentioned in particular in the text includes:

A drinking water

C water for industry

B water for growing vegeiables and other crops

D all the mentioned above

2 The number of 97.3 percent refers to:

A the world's water

C glaciers and sheets

B water in the oceans

D water movement

3 Why does hydrology overlap with other sciences?

A Because it studies water in oceans and atmosphere

B Because it is concerned with water's quality

C Because it is concerned with river water's quality and quantity

D Because it is concerned with the quantity and quality of water

4 According to the text, the imbalances that hydrologists and engineers have to counteractconsist of:

A temporal differences

B spatial and temporal imbalances

C water supply

D design and construction of reservoirs and water transfer

A provides reliable, clean water supplies

B makes some efforts on providing reliable, clean water supplies

C makes all efforts on providing reliable, clean water supplies

D makes almost all efforts on providing reliable, clean water supplies

C PRACTICE

I Match a word in column A with a definition in column B

dirty water etc

and within the underlying soil and rocks

across a valley or low ground

patterns of climate and weather

10 meteorology j a layer of rock or soil that can absorb or hold water

II Change the sentences into passive voice

1 People use rivers to dil ute industrial and domestic wastes

2 Temporal differences also cause significant problems

3 Converting farmland to roads or factories reduces infiltration and produces more rapid off of rainfall into rivers and increases flooding

run-4 People destroy forests to grow crops

5 Global warming is producing climatic changes

6 Hydrologists and climatologists assess the impact of these anticipated changes

7 Hydrologists and engineers together counteract these spatial and temporal imbalances

8 Chemical processes control the movement of water interaction

III Fill in the blank with a suitable word

In general hydrology is defined as a major science It studies every side of

engineering As a branch of the former, hydrology is studied to measure and understand the

processes Furthermore, the study of water's interaction with both natural environment andwith human activities is not beyond the scope As a branch of civil engineering, hydrology

(6) of natural or artificial changes to river and ground water flows Finally, hydrology plays a

(7) role in assisting in solving problems related to these extreme conditions and

moves through rocks that have a high pore space

ponds, and even waste-water treatment systems

5 Irrigation is the application of water to the soil usually for assisting in growingcrops when there is not enough water for crops or land

6 Soil moisture is the water that is held in the spaces soil particles

7 The water cycle is a process that is constantly the Earth's supply of water

within the underlying soil and rocks (move)

hence run-offpattems (climate)

resources (available)

VI The picture below describes the water cycle Look at the picture and read the

following text about water cycle Fill in the blank with a suitable word

The water cycle is the way the Earth uses and recycles water It's controlled (I) the

evaporate

When water is heated, it changes from a liquid to a gas This gas is called (4), andthe process is called evaporation When plants give off water vapor, it's called (5).When water evaporates, it rises into the cooler air, collects, and forms clouds There, the

UNIT 3: FLUID MECHANICS

Undoubtedly you have observed the movement of clouds in the atmosphere, the flight

of birds through the air, the flow of water in streams, and the breaking of waves at theseashore Fluid mechanics phenomena are involved in all of these Fluids include gases andliquids, with air and water as the most prevalent Some of the many other aspects of our livesthat involve fluid mechanics are flow in pipelines and channels, movements of air and bloorl

in the body, air resistance or drags, wind loading on buildings, motion of projectiles, jets,shock waves, lubrication, combustion, irrigation, sedimentation, and meteorology andoceanography The motions of moisture through soils and oil through geologic formations areother applications A knowledge of fluid mechanics is required to properly design watersupply systems, wastewater treatment facilities, dam spillways, valves, flow meters, hydraulicshock absorbers and brakes, automatic transmissions, aircraft, ships, submarines, breakwaters,marinas, rockets, computer disk drives, windmills, turbines, pumps, heating and airconditioning systems, bearings, artificial organs, and even sports items like golf balls, yachts,race cars, and hang gliders It is clear that everybody's life is affected by fluid mechanics in avariety of ways All engineers should have at least a basic knowledge of fluid phenomena.Fluid mechanics is the science of the mechanics of liquids and gases, and is based onthe same fundamental principles that are employed in the mechanics of solids The mechanics

of fluids is more complicated subject than the mechanics of solids, however, because withsolid one deals with separate and tangible elements, while with fluids there are no separateelements to be distinguished

Fluid mechanics can be divided into three branches: fluid static is the study of themechanics of fluids at rest; kinematics deals with velocities and streamlines withoutconsidering forces or energy; and fluid dynamics is concerned with the relations betweenvelocities and accelerations and the forces exerted by or upon fluids in motion

Classical hydrodynamics is largely a subject in mathematics, since it deals with animaginary ideal fluid that is completely frictionless The results of such studies, withoutconsideration of all the properties of real fluids, are of limited practical value Consequently,

in the past, engineers turned to experiments, and from these developed empirical formulas thatsupplied answers to practical problems When dealing with liquids, this subject is calledhydraulics

Empirical hydraulics was confined largely to water and was limited in scope Withdevelopments in aeronautics, chemical engineering, and the petroleum industry, the needarose for a broader treatment This has led to the combining of classical hydrodynamics (idealfluids) with the study of real fluids, both liquids (hydraulics) and gases, and this combination

we call fluid mechanics In modem fluid mechanics the basic principles of hyrodynamics arecombined with experimental data The experimental data can be used to verify theory or toprovide information supplementary to mathematical analysis The end product is a unifiedbody of basic principles of fluid mechanics that we can apply to the solution of fluid-flowproblems of engineering significance With the advent of the computer, during the past 25years the entirely new field of computational fluid dynamics has developed Variousnumerical methods such as finite differences, finite elements, boundary elements, andanalytical elements are now used to solve advanced problems in fluid mechanics

A GRAMMAR REVIEW

1 Passive voice

- Present Simple: amIislare +PP

Example:Fluid mechanics phenomena are involved in all of these

- Past Simple: was/were +PP

Example:Empirical hydraulics was confined largely to water and was limited in scope

- Infinitive:

• Modal verbs: modal auxiliary verb + be + PP

Example: The experimental data can be used to verify theory or to provide information supplementary to mathematical analysis.

• to be + PP

Example: There are no separate elements to be distinguished.

- In relative clause (s/lOrtenedform): Theforces exerted by or uponfluids in motion.

USE:

- When it is not necessary to mention the doer of the action

- We choose the activeor passive depending on what we are more interested in.

2 Adverbs

FORMATION OF ADVERBS WITH Lf

- adj +ly: undoubtedly, largely, properly, entirely, consequently

- Adverbs of time: usually come at the beginning or the end of the sentence or clause, but

in passives, come after the auxiliary

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",

Example: analytical elements are now used to solve advanced problems in fluid mechanics.

- Sentence adverbs: at the beginning, at the end or after the verb "to be"

Example:

Undoubtedly you have observed the movement 0/clouds in the atmosphere, the flight 0/

birds through the air, the flow 0/ water in streams, and the breaking 0/ waves at the seashore.

Classical hydrodynamics is largely a subject in mathematics.

Be combined with: duQ'c ket hgp vrn

Be involved in: xuAt hi~nCt

I Decide if the following statements are TRUE (T) or FALSE (F)

1 The movement of clouds in the atmosphere and the flow of water in streams are not

affected by fluid mechanics

2 The mechanics of solids, which deals with tangible elements is not as complicated as themechanics of fluids

3 The relations between velocities and accelerations and the forces exerted by or upon fluidsare the main point in the study of the mechanics of fluids at rest

4 The results of the studies of classical hydrodynamics are used to supply answers to

practical problems

5 The unified body of basic principles of fluid mechanics can be applied to the solution offluid-flow problems of engineering significance

II Answer the following questions:

1 What is the definition of fluid mechanics?

2 Why does an engineer need to have knowledge about fluid mechanics?

3 What is more complicated, the fluid mechanics or solid mechanics? Why?

4 What is the function of kinematics?

5 What is hydraulics for?

6 Why did we have to combine the classical hydrodynamics with the study of real fluids?

7 Why do we need experimental data?

8 How can we deal with advanced problems in fluid mechanics now?

C PRACTICE

I Change the following sentences into actives

I Everybody's life is affected by fluid mechanics in a variety of ways

3 In modem fluid mechanics, the basic principles of hydrodynamics are combined withexperimental data by researchers.

4 The experimental data can be used to verify theory in mathematical analysis

5 For engineers, knowledge of fluid mechanics is required to properly design water supplysystems

II Match a word with its definition

I hydraulics A connected with scientific experiments.

2 at~osphere B using a logical method of thinking about sth in order to understand it,

especially by looking at all the parts separately

3 dynamics C a liquid or a substance that can flow.

4 experimental D a machine that is used to force liquid, gas or air into or out of sth.

5 turbine E to use power or influence to affect sb/sth.

6 analytical F the science of the forces involved in movement.

7 absorb G the mixture of gases that surrounds the earth

8 fluid H a machine or an engine that receives its power from a wheel that is

turned by the pressure of water, air or gas

9 pump' I the science of the use of liquids moving under pressure.

10 exert J to take in a liquid, gas or other substance from the surface or space

around

III Word formation

computational fluid dynamics has developed (ENTIRE)

properties of liquids (MECHANICS)

theory (COMBINE)

IV Find thc odd onc out: Among tile following words or pllrases in eacll group tilere is a word! pllrase wllicll does not belong to tile group

V Fill each of the following gaps with an appropriatc word

Tile Basic Idea of How Hydraulic Machines Work

The basic idea behind any hydraulic system is very simple: Force that is applied at onepoint is transmitted to another point using an incompressible fluid The fluid is almost always

an oil of some sort The force is almost always multiplied in the process The picture belowshows the simplest possible hydraulic system:

ApplyForce

In this drawing, two pistons (red) fit into two glass cylinders filled with oil (light blue)

(5) is incompressible, the efficiency is very good - almost all of the applied

it to snake through all sorts of things separating the (,8) pistons The pipe canalso fork, so that one master cylinder can drive more than one slave cylinder if desired

25

VI Match the pictures and the words! phrases below

4

27

UNIT 4: THE SCIENCE OF STRENGTH OF MATERIALS

In designing structures and machines, an engineer has to select the material and thecross-sectional area of each element of the structure or machine so that it enables the element

to have strength to resist external forces transmitted to it by adjacent elements of the structurewithout failure of strength or distortion of shape, i.e the element should function properly.Strength of materials provides the engineer with fundamentals for a proper solution of thi~problem

Strength of materials deals with the behavior of various materials under the action ofexternal forces and points out how to select the appropriate material and the cross-sectionalarea of each element of the structure so as to provide fully reliable functioning and the mosteconomic design

Sometimes, strength of materials has to deal with the problem in a modified form tocheck the dimensions of a designed or existing structure

The conditions for a maximum economy in design and reliability of functioning arecontradictory The former demands minimum consumption of materials whereas the latterleads to increase in consumption This contradiction forms the basis of the technique, whichhas facilitated the development of strength of materials

Often the existing methods of checking the strength of available materials are unable tomeet the prac'tical requirements for providing answers to new problems (for example,attaining high speeds in engineering in general and in aerostatics in particular, long-spanstructures, dynamic stability, etc) This initiates a search for new materials and study of theirproperties, and inspires research for improving the existing methods of designing anddevising the new ones Strength of materials must keep pace with the general development ofengineering and technology

Sometimes, besides the chief requirements of maximum reliability and economy, anengineer has to ensure fulfillment of other conditions too, such as quick building (whenrestoring broken structures), minimum weight (in aircraft design), etc These conditionsinfluence the dimensions, the shape and the material of the various elements comprising thestructure

The emergence of strength of materials as a separate science dates back to 1638 and isintimately connected with the works of Galileo Galilei, the great Italian scientist Galileo was

a professor of mathematics at Padua He lived in a period, which saw the disintegration of thefeudal system, the development of trade capital and international maritime transport, and thebirth of mining and metallurgical industries

The rapid economic development of those times called for speedy solutions of newtechnological problems Increase in international maritime trade perpetuated the need for

bigger ships which in turn entailed changes in their design; at the same time it becamenecessary to reconstruct the existing and to build new internal waterways, including canalsand sluices These new technical problems could not be solved by simply copying the existingdesigns of ships; it became necessary to judge the strength of elements keeping in mind theirsize and the forces acting upon them

Galileo devoted a considerable part of his work to the study of the dependence betweenthe dimensions of beams and bars and the loads they could withstand He pointed out that theresults of his experiments may prove very useful in building big ships, especially instrengthening the deck and covering, because low weight is very important in structures ofthis type

Further development of strength of materials went on in step with the progress ofmechanical and civil engineering, and materialized owing to the research work done by alarge number of eminent scientists, mathematicians, physicists and engineers

1 Relative Clauses with relative pronouns: Which, who

Who is used for people; which is used for thingsExamples:

- David has worked very hard He gets a higher salary from his company

-7 David who gets a higher salary from his company has worked very hard

- Unit 4 is very interesting .!!provides us useful information about strength of materials

-7 Unit 4 which provides us useful information about strength of material is very interesting

- This contradiction forms the basis of the technique This basis of technique has facilitatedthe development of strength of materials

-7 This contradiction forms the basis of the technique which has facilitated the development

of strength of materials

Note: Reduced forms of relative clauses: used when verbs in the relative clauses are in the present participle (V-ing) or past participle (VPII)

Examples:

- The man is my uncle He is silting next to you

-7 The man who is sitting next to you is my uncle

-7 The man sitting next to you is my uncle

- The books are very interesting They were written by To Hoai

-7 The books which were written by To Hoai are very interesting

-7 The books written by To Hoai are very interesting

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2 Must! Have to

Must: strong obligation, come from "inside" the speaker.

Have to: strong obligation, come from "outside"; a rule, a law, or from someone in authority Examples:

- You have to have a driving license if you want to drive a car (That's the law)

- Imust get my hair cut (I think it's necessary)

3 Phrases and clauses of purposes:

-To V

- In order to + V

- So that +clause

Examples:

- I try to study hard to pass my next exam.

- We learn English in order to have better communication with other people.

- He does morning exercises regularly so that he can improve his health.

I Answer the following questions

I Why does an engineer have to select the material and the cross-sectional area ofelement of the structure or machine carefully?

2 Which problem does the strength of materials sometimes have to deal with?

3 What is the contradiction in choosing materials?

4 According to the text, what are the conditions that an engineer has to ensurefulfillment?

5 What was the requirement of the Galileo's time? Why did it appear?

II Are the following sentences True or False? Correct the false ones

functioning assists the development of strength of materials

2 The conditions such as: quick building, minimum weight etc influence the structures

3 The existing methods of checking the strength of available materials help to deal withnew problems

4 Increase of international maritime trade led to the changes in the ship design

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5 Galileo's works focused more on the shipbuilding

6 During Galileo's times, new technical problems dealt with the judgment of the strength

of elements in size and the forces acting upon them

III Discussion

Pair work: discuss the following question:

Why should an engineer have the knowledge oj strength oj materials?

C PRACTICE

I Combine the following sentences using relative pronouns

I Strength of materials is the science It provides the engineer with fundamentals for a propersolution of this problem

2 External forces are the forces These forces are transmitted to the element by adjacentelements

3 Engineers must choose the appropriate materials These materials must provide fullyreliable functioning and the most economic design

4 An engineer has to fulfill some conditions The conditions are quick building, minimumweight

5 Galileo had some considerable works Those works studied the dependence betweenbeams, bars and the loads they could withstand

6 A search is being carried out This search is looking for the new methods of designing

7 Galileo was a professor of mathematics at Padua He had some works related to thestrength of materials

8 The structures won't have strength The structures have distortion of shape

9 Strength of materials is materials science The science is applied to the study of engineeringmaterials and their mechanical behavior in general

II Rewrite the sentences using must! have to

1 It's certain that an engineer needs the thorough knowledge of strength of materials

4 I'm sure each element of this structure functions properly.

III Use a phrase or clause of purpose to combine each pair of sentences below

I The bigger ships and new internal waterways need to be built People want the bigger

ships to meet the requirement of increase in international maritime trade

2 Mr Jean chooses the materials of each element of the structures very carefully He

wants to make sure that the elements can resist the external forces

3 Engineers are carrying out a search for the existing methods of designing and devising

the new ones They want to find answers to new problems

4 Engineers have to select the material and the cross-sectional area of each element of the

structure or machine It enables the element to function properly

IV Match the given nouns/noun phrases with a suitable group of pictures

distortion of shapelong-span structureexternal force