all start with a measurement known as a nanometer. A
is a billionth of a mete,
which means we are operating at the level of atoms and molecules. A human hair is
approximately 100,000 nanometers in diameter. (Nanotechnology is a science based on
using molecules to create tiny machines to hold data or
perform tasks. Experts attempt to
do “nanofabrication” by building tiny “nanostructures” one atom or molecule at a time.
When applied to chips and other electronic devices, the field is called “nanoelectronics.”)
A final possibility is using
biotechnology to grow cultures of bacteria, such
as one that, when exposed to light, emits a small electrical charge. The properties of this
“biochip” could be used to represent the on
off digital signals used in computing.
Imagine millions of nanomachine
s grown from microorganisms processing information at the
speed of light and sending it over far
reaching pathways. What kind of changes could we
expect with computers like these?
Biology Input Devices
Human biology input devices include bio
metric systems, line
sight systems, cyber gloves and
body suits, and brainwave devices.
Characteristics and movements of the human body, when interpreted by sensors, optical
scanners, voice recognition, and other technologies, can become forms of input.
are as follows:
Biometric systems: Biometric security devices
identify a person through a fingerprint, voice
intonation, or other biological characteristic. For example, retinal
identification devices use
a ray of light to identify the disti
nctive network of blood vessels at the back of one’s
eyeball. Biometric systems are used in lieu of typed passwords to identify people
authorized to use a computer system.
sight systems: Line
enable a person to use his or her eyes
“point” at the screen, a technology that allows physically handicapped users to direct a
computer. This is accomplished by a video camera mounted beneath the monitor in front
of the viewer. When the user looks at a certain place on the screen, the video
computer translate the area being focused on into screen coordinates.
Cyber gloves and body suits:
Special gloves and body suits
often used in conjunction with
“virtual reality” games (described shortly)
use sensors to detect body movements
data for these movements is sent to a computer system. Similar technology is being used
controlled robot hands, which are used in nuclear power plants and hazardous
Perhaps the ultimate input device analyzes
the electrical signals of the
brain and translates them into computer commands. Experiments have been successful in
getting users to move a cursor on the screen through sheer power of thought. Other
experiments have shown users able to type a letter by sl
owly spelling out the words in their
heads. Although there is a very long way to go before brainwave input technology becomes
practicable, the consequences could be tremendous, not only for handicapped people but
ay screens are either CRT (cathode
ray tube) or flat
panel display. CRTs use a vacuum tube
like that in TV set. Flat
panel displays are thinner, weigh less, and consume less power but are
not as clear. Flat
panel displays are liquid
crystal display (LCD),
electroluminescent (EL) display,
plasma display. Users must decide about screen clarity, monochrome versus color, and text
versus graphics (character
mapped versus bitmapped). Various video display adapters (such as
VGA, SVGA, and XGA) allow variou
s kinds of resolution and colors.
also variously called monitors, CRTs, or simply screens
are output devices that
show programming instructions and data as they are being input and information after it is
processed. Sometimes a display
screen is also referred to as a VDT, for video display terminal,
although technically a VDT includes both screen and keyboard. The size of a screen is measured
diagonally from corner to corner in inches, just like television screens. For desktop
inch screens are a common size. Portable computers of the notebook and
subnotebook size may have screens ranging from 7.4 inches to 10.4 inches. Pocket
computers may have even smaller screens. To give themselves a larger screen size, some
computer users buy a larger desktop monitor (or a separate “docking station”) to which
the portable can be connected. Near the display screen are control knobs that, as on a television
set, allow you to adjust brightness and contrast.
s are two types: cathode
ray tubes and flat
ray tubes (CRTs)
The most common form of display screen is the CRT. A CRT, for
ray tube, is a vacuum tube used as a display screen in a computer or video display
terminal. This s
ame kind of technology is found not only in the screens of desktop computers but
also in television sets and in flight
information monitors in airports.
if CRTs were the only existing technology for computer screens, we would
carrying around 25
pound “luggables” instead of lightweight notebooks, subnotebooks,
and pocket PCs. CRTs provide bright, clear images, but they consume space, weight, and power.
Compared to CRTs, flat
panel displays are much thinner, weigh less, and cons
ume less power.
Thus, they are better for portable computers.
The first Robot Olympics was held in Toronto in November 1991. “Robots competed for honors in
jumping, rolling, fighting, climbing, walking, racing against each othe
r, and solving
problems,” reported writer John Malyon. For instance, in the Micromouse race, robots had to
negotiate a standardized maze in the shortest possible time.
A robot is an automatic device that performs functions ordinarily ascribed to human bein
gs or that
operate with what appears to be almost human intelligence. Actually, robots are of several kinds
industrial robots, perception systems, and mobile robots, for example. All are the objects of study
of robotics, a field that attempts to develop ma
chines that can perform work normally done by
people. Robotics in turn is a subset of artificial intelligence, a family of technologies that attempts
to develop computer systems that can mimic or simulate human thought processes and actions.
Robots are of
interest to us as output devices because they can perform computer
electromechanical functions that the other devices so far described cannot. For example, a robot
resembling a miniature tank was able to explore the inside of the Great Pyramid of Gi
za in Egypt.
Equipped with treads bottom and top, and carrying lights and television camera, the robot was
able to probe an 8
long shaft to a formerly hidden chamber in the pyramid. A
robot called ScrubMate
equipped with computerized co
ntrols, ultrasonic “eyes,” sensors, batteries,
three different cleaning and scrubbing tools, and a self
can clean bathrooms.
Rosie the HelpMate delivers special
order meals from the kitchen to nursing stations in hospitals.
Robodoc is used in
surgery to bore the thighbone so that a hip implant can be attached. Robots
are also used for dangerous jobs such as fighting oil
well fires, doing nuclear inspections and
cleanups, and checking for mines and booby traps. When equipped with video and two
audio, they can also be used to negotiate with terrorists.
logic (a method of dealing with imprecise data and vagueness, with problems that have
many answers rather than one) principles are being applied in another area o
f AI, neural
networks. The word
comes from neurons, or brain cells.
electronic devices or software to mimic the neurological structure of the human brain. The human
brain is made up of nerve cells (neurons) with a three
dimensional lattice of connections between
them (axons). Electrical connections between nerve cells are activated by synapses. In a
hardware neural network, the nerve cell is replaced by a transistor, which acts as a switch. Wires
connect the cells (transi
stors) with each other. The synapse is replaced by an electronic
component called a resistor, which determines whether a cell should activate the electricity to
other cells. A software neural network emulates a hardware neural network, although it doesn’t
work as fast.
The essential characteristics of neural networks are as follows:
Learning: Like a small child, a neural network can be trained to learn by having its mistakes
corrected, just as the human brain learns by making changes in the links (synapses)
between nerve cells.
One writer gives this example: “If you’re teaching the neural network to speak, for
instance, you train it by giving it sample words and sentences, as well as desired
pronunciations. The connections between the electronic neurons grad
allowing more or less current to pass.” The current is adjusted until the system is able to
How effective are neural networks? One such program learned to pronounce a 20,000
vocabulary overnight. Another helped a mutua
fund manager to outperform the stock market by
5.6 percentage points over three years. As a San Diego hospital emergency room in which
patients complained of chest pains, a neural network program was given the same information
doctors received. It co
rrectly diagnosed patients with heart attacks 97% of the time, compared to
78% for the human physicians.
3G refers to the third generation of mobile telephony (that is, cellular) technology. The third
generation, as the name sugg
ests, follows two earlier generations.
The first generation (1G) began in the early 80's with commercial deployment of Advanced Mobile
Phone Service (
lular networks. Early AMPS networks used Frequency Division
Multiplexing Access (
) to carry analog voice over channels in the 800 MHz frequency band.
econd generation (2G) emerged in the 90's when mobile operators deployed two competing
digital voice standards. In North America, some operators adopted IS
95, which used Code
Division Multiple Access (
) to multiplex up to 64 calls per channel in the 800 MHz band.
Across the world, many operators adopted the Global System for Mobile communication (
standard, which used Time Division Multiple Access (
) to multiplex up to 8 calls per channel
in the 900 and 1800 MHz bands.
International Telecommunications Union (
) defined the third generation (3G) of mobile
to facilitate growth, increase bandwidth, and suppor
diverse applications. For example, GSM could deliver not only voice, but also circuit
at speeds up to 14.4 Kbps. But to support mobile multimedia applications, 3G had to deliver
switched data with better spectral efficiency, at
far greater speeds.
However, to get from 2G to 3G, mobile operators had make "evolutionary" upgrades to existing
networks while simultaneously planning their "revolutionary" new mobile broadband networks.
This lead to the establishment of two distinct 3G f
amilies: 3GPP and 3GPP2.
The 3rd Generation Partnership Project (3GPP) was formed in 1998 to foster deployment of 3G
networks that descended from GSM. 3GPP technologies evolved as follows.
• General Packet Radio Service (
) offered speeds up to 114 Kbps.
• Enhanced Data Rates for Global Evolution (
) reached u
p to 384 Kbps.
• UMTS Wideband CDMA (
) offered downlink speeds up to 1.92 Mbps.
• High Speed Downlink Packet Access (
) boosted the downlink to 14Mbps.
• LTE Evolved UMTS Terrestrial Radio Access (E
UTRA) is aiming for 100 Mbps.
Managers are charged with getting work d
one through people effectively and efficiently.
Effectiveness refers to the achievement of the desired objectives. Thus, if a business’s goal is for
customers to be pleased with its products, an engineering department is effective when it designs
customers will like. Efficiency refers to minimal use of resources. An efficient engineering
department does its job without wasted time and materials. Note that getting a lot done at a low
cost (efficiency) is not desirable without effectiveness. For bus
iness organizations, the
fundamental indicator that they are operating effectively and efficiently is profit.
Managers seek effectiveness through the way they manage resources. Managers acquire and use
three broad categories of resources: physical, organiz
ational, and human capital. Skillfully
managing any of these can improve performance; however, it is interesting to consider whether
one category of resources is most important in giving organizations a sustainable competitive
physical resources include the technology it uses, its plant and equipment, its
geographic location, and its access to raw materials. The money an organization can raise or earn
may also be thought of as part of its physical resources. The management of ph
encompasses a variety of activities. The organization needs to acquire technology and equipment
that help it deliver greater value to its customers (in terms of better service, lower cost, or both);
empt or block competitors; or lock i
n customers by giving them something they cannot get
elsewhere. The organization also needs to select sites, acquire parts and materials, finance its
activities, and dispose of any resources that cease providing enough benefits.
Effectively and efficiently
managing physical resources certainly helps an organization’s
performance. Setting up a modern factory, getting financing at a low interest rate, or linking
employees to suppliers with current communications technology can keep costs down, improve
anization’s goods and services, or both.
However, these resources do not provide a sustainable competitive advantage. Although they are
valuable, other organizations eventually can
use the same tactics, leaving several
organizations on the same
footing. Thus, when Whistler, a U.S. consumer electronics company,
was losing market share to Asian competitors, the company concluded it would have to cut
manufacturing costs to its competitors’ levels or move its operations offshore. Whistler chose the
cutting option, but by the time costs were reduced to the desired levels, the same
competitors were gaining market share through product innovations. Yet Whistler’s management
had stopped focusing on product development. As at Whistler, organizations
managers who can manage more than physical resources.
The concept that managers should care about and encourage ethics
principles of morally
is not new. However, ethical issues merit special mention for two
One is that the behavior of managers is under greater scrutiny than in the past. Because people
have more access to information, misdeeds become widely known, greatly damaging the
organization’s reputation, and a good reputation, which can take ye
ars to build, can be destroyed
in minutes. In addition, today’s public has high standards for the behavior of managers. This has
resulted not only in customer demands for ethical behavior but also in increased government
regulation of organizational activi
Giving the challenge of ethics in the modern organization, what are managers to do? They should
be aware of situations that have the potential to cause harm. When such situations arise,
managers should identify alternative, less damaging courses of a
Also, managers can create a climate that encourages ethical behavior by all employees. Creating
such a climate includes identifying situations in which ethical issues may arise, developing policies
governing behavior in such situations, and ensuring
that the organization’s rewards (including pay
and praise) reinforce ethical behavior. Formal policies are important; however, organizations
presumably want to encourage a high standard of behavior. Doing so requires that managers
model and reward ethical
behavior, not just say they think it is important.
Views of ethics
: When people confront issues related to ethics, they need some guides to choose
a course of action. The ultimate decision depends in part on the person’s view of ethics. The usual
ve been summarize as utilitarian, Golden Rule, Kantian and enlightened self
course, views of ethics are only as important as the behaviors they lead to.
The Golden Rule is a name Christians have given to Jesus’s teaching “do to ot
you would have them do to you”
a principle that is found in most, if not all, world religions. This
view requires identifying various courses of action and choosing the one that treats others the
way you would want to be treated. The ‘others’ to
consider are the organization’s stakeholders
all those who are affected by the organization’s policies and practices. Stakeholders include the
organization’s investors, customers, and employees, among others.
While an organization’s m
anagers are trying to learn what customers need and how to meet that
need, managers at competing organizations are doing the same. In general, competitors are the
organizations that seek to meet the same customer needs. For example, video rental stores and
cable and network television stations serving the same geographic area are all competitors.
Impact of Competitors.
Competitors limit the organization’s access to resources. They often
compete for the same inputs (such as talented employees), and they comp
ete for the revenues
from the customers they would like to serve.
The impact of competitors is strongest when barriers to entry are low and buyers are willing to
accept substitutes for the organization’s products.
Given the potential impact of competitors,
organizations need information about what competitors
are doing. An organization can help maintain its competitive edge by giving employees at all levels
access to such information. Chef Allen’s, a restaurant located in North Miami Beach, Florida, gives
ts servers and cooks an allowance of $50 apiece to dine in any comparable restaurant and report
what they learned. One cook told his colleagues that the elegant meal he ordered was ruined by
being served on cold plates. “He thought more about warming up pl
ates after that,” says Allen
Susser, owner of Chef Allen’s.
Trends in the Competitive Environment: The global nature of modern business has made
competitions more complex and challenging for U.S. companies. Competitors from other countries
have used higher
quality and lower costs to erode the large market share once held by U.S. firms.
Thus, although U.S. firms used to dominate the worldwide automobile and computer industries,
their share has tumbled in recent decades. And among the dozen largest banks in t
today, none are U.S. banks.
Managers are especially likely to be surprised by competitors when they have focused their
information gathering exclusively on well
known organizations or on existing technology. For
example, the long
ABC, CBS, and NBC
considered cable TV a
fringe business, so they were unprepared for the success of Turner Broadcasting System and
other cable companies. Furthermore, readership of newspapers has declined as people turn to
cable TV for news
and other information. After a decade of this trend, some major newspapers,
including the New York Times and Los Angeles Times, finally began to view their industry more
broadly to encompass all news media.
Planning and F
ferent organizations will choose different tactics for managing the environment,
managers should begin by trying to understand what is happening in the environment, what is
likely to happen, and what actions will be most beneficial to the organization. To
managers rely on planning and forecasting.
An organization is most likely to benefit from the opportunities in its environment and
avoid environmental threats if its managers have thought through the possible courses of action
and set go
als accordingly. This is the process of planning. To plan effectively, managers begin by
gathering and reviewing information. Gathering information about the dimensions of the
organization’s environment is environmental scanning. To scan the environment, m
others in the organization may review government statistics, conduct surveys, and read relevant
magazine, newspaper, and journal articles.
To plan for the future, managers need a sense of what members of the
organization will be do
ing. Of course, they cannot know for sure what will happen, but they have
to make predictions. Predicting future environmental needs and actions is called forecasting.
Generally, the approach is to use the data gathered in environmental scanning to look fo
that may extend into the future.
No one can be certain about the future, regardless of how sophisticated the forecasting model.
More often than not, changes in the environment will make a forecast at least slightly incorrect.
Today, computer mode
ls allow managers to see how changing their assumptions about
environmental conditions will affect forecasts. But not even these models can predict a major
Consider the growth of the computer industry. James Fallows, Washington editor of th
Monthly, expects it will transform our lives in unexpected ways, some of them negative. For
instance, if only educated people possess computer skills, the growing importance of computers is
likely to widen the economic gap between the well educa
ted and the remainder of society. Yet the
forecasting done by the computer industry as largely been limited to such issues as how many
new products will be purchased and what applications can be devised for them. Fallows describes
a recent speech by Micros
oft CEO Bill Gates as “a vision … that boiled down to a picture of lotsa,
lotsa computers in our future lives.” Fallows himself forecasts that this limited vision will breed
suspicion and distrust among a general public that perceived the computer business
unwilling or unable to care about the more far
reaching social impact of computers.
Business Level Strategy
An organization also needs business
level strategy for each business unit or product line. In the
case of Disney, this would mean
level strategies for its amusement parks, its sports
teams, its condos, and so on. At this level, strategy describes how the business unit or product
line will compete for customers. Possible strategies might include investing heavily in research
development, aggressively adding new products to an existing line, or changing the products in
the line to attract new customers.
level strategy at IBM was to make extensive use of patents to block competitors from
offering comparable mainfr
ame computers. Because this strategy also prevented customers from
running their software on competitor’s machines, it also locked in customers for years until they
were ready to invest in new software. In contrast, when IBM launched its personal computers
chose a strategy of getting the products to market quickly. To do so, IBM used so
architecture, which meant that other companies could write compatible software and build
machines that could run the software. Therefore, its strategy for PC
s gave the company a less
The relationship between corporate
level strategies depends on the size and
complexity of the organization. In small organizations with a single type of product, business
strategy may simply ex
tend and elaborate on corporate
level strategy. But a big, diversified
organization like General Electric requires a corporate
level strategy that is broad enough to
encompass all the organization’s groups as well as a business
level strategy for each area
business in which the organization is involved.
Functional: Each functional department
such as marketing, finance, manufacturing, and
may devise a strategy for supporting the higher
level strategies. Thus, a production
manager who thinks
strategically looks beyond keeping costs down and making workers and
machines more efficient. This manager considers how to support the organization’s strategy by
contributing to the organization’s competitive advantage, say, by adapting processes particul
customer needs or by offering additional services.
A number of years ago, McDonald’s Corporation (which had a strategy for growth that included
opening more stores) forecast that not enough U.S. teenagers would be available to work in its
stores. The hu
man resource unit therefore supported the corporate
level growth strategy was to
recruit and hire older, retired people (a growing segment of the population)
Forces for C
External forces. When the organization’s general or task environment ch
anges, the organization’s
success often rides on its ability and willingness to change as well. The general environment has
social, economic, legal and political, and technological dimensions. Any of these can introduce the
need for change. In recent years
reaching forces for change have included developments in
information technology, the globalization of competition, and demands that organizations take
greater responsibility for their impact on the environment.
For Hugo Boss, a German producer of men
swear, recent forces for change have been economic
and social. Slow economic growth has forced the company to keep its costs as low as possible. As
a result, Hugo Boss decided to cut its German manufacturing base from 40 percent to 20 percent.
Like other G
erman manufacturers, Hugo Boss moved much of its production to Eastern European
countries including Romania, Slovenia, and the Czech Republic, where labor costs are much lower.
In the social environment, a trend toward more casual dress at work has cut int
o sales of
traditional Boss suits. The company responded by creating its more casual and colorful Hugo line.
Because the task environment interacts directly with the organization, it is an especially important
source of forces for change. The task environm
ent includes the organization’s customers,
competitors, regulators, and suppliers. A force for change at Russia’s Bolshoi Ballet Academy is
that the government can no longer provide the lavish support it provided in the past. To keep
float, the school must
consider a broader range of funding sources, notably grants from local
businesspeople. The Bolshoi is also seeking special concessions from the Russian legislature,
including tax breaks for contributing to cultural institutions. In addition, the Bolshoi s
eeks to raise
hard currency by touring internationally.
For Tata Iron & Steel Company, foreign investors (suppliers of capital)
are a new force for
change. In the past, Tata emphasized the creation of jobs in its community of Jamshedpur, a city
India. Tata’s 78,000 workers receive lifetime employment, along with free housing,
education, and medical care. The company, in turn, has benefitted from a complete lack of strikes
in 60 years. But investors interested in Tata have asked how the company mi
ght improve its profit
margin of only 3.7 percent. Notes Tata’s managing director, Jamshed Irani, “We will now be
forced to balance loyalty against productivity.”
Individual and Organizational V
An organization upholds certain values as a p
art of its culture. At Levi’s and at Ben & Jerry’s
Homemade, the values include ethical management practices and employee empowerment. The
individuals in an organization also have sets of values. These individual values may vary in the
extent to which they
resemble the organizational values, especially in an organization with a
diverse work force. Such differences may be minimized by the tendency of individuals to accept
jobs with organizations that demonstrate values matching their own.
Because values infl
uence behavior, organizations need employees who share the values of the
organizational culture. Recognizing this, Jack Welch, CEO of General Electric, wrote in a recent
Managers who hit their numbers [meet performance objectives] and live
by GE’s values
expect to get promoted. Managers who don’t hit their numbers but live by GE’s values can expect
a second chance. Managers who don’t hit their numbers and don’t live by GE’s values will be fired.
As for managers who hit their numbers but don’
t live by GE’s values? Well, they may be financial
geniuses welcome at a lot other companies, but we no longer want those types of managers in
When an individual’s values differ from the prevailing values of the organizational culture, co
results. In some cases, the individual faces ethical dilemmas. For example, suppose a manager
values honesty above financial gain, but the organization places higher value on maintaining
profitability with whatever lawful tactics are necessary. This
manager could at times be expected
to implement strategies that (even if legal) do not meet the manager’s standards for honesty.
Ideally, managers and other employees will find solutions that do not compromise either set of
values. When surgeon and bioch
emist P.Roy Vagelos left Washington University to head Merck’s
research labs, he faced what he calls “the challenge of a lifetime”: “I needed to hold on to the
values that were important to me as a physician and blend them with Merck’s need to remain
table.” By leading the development of numerous vaccines and medicines, Vagelos helped
Merck make a major difference in the health of millions of people and thrive as a company.
Job Satisfaction and Job Pe
Why should managers care whether
their employees are satisfied with their jobs? For some
managers, this is a matter of ethics or of consideration for others. In terms of strategic
management, we need to know whether a satisfied employee will contribute more to achieving
objectives than a
dissatisfied employee will. For this reason, researchers have investigated
whether there is a link between job satisfaction and job performance.
This research tested the once
widespread assumption that satisfaction is related to job
s looked for a correlation between the two; that is, they investigated
whether raising job satisfaction would lead to an increase in job performance. Overall, that
research failed to find such a link, and by the 1950s the consensus was that satisfaction an
performance are unrelated.
More recent investigations have considered whether satisfaction and performance may be related
in some other, less direct way. And they made a model. A test of the model on 1,200 employees
in four organizations found overall su
pport for the model. Although not all relationships in the
model were found highly significant, the data supported the general concept of a model in which
job satisfaction and job performance covary subject to motivational factors. Other research also
identified covariances between the two. For example, a review of over 200 studies in which
based interventions sought to raise productivity and performance found that 87
percent raised productivity by some measure and three
quarters also re
sulted in greater job
satisfaction. This evidence is also consistent with our model of individual differences, in which we
show the effect of attitudes on outcomes to be indirect, via motivation.
As a practical matter for managers, this means that job sati
sfaction is important, but that
managers must view it in the context of motivation. If the motivational factors in an organization
do not fit the pattern called for by the model they can reduce, eliminate, or even reverse the
relationship between satisfact
ion and performance. For example, making goals more challenging
could increase performance, but if rewards do not rise as well, job satisfaction could decline
because employees believe the reward system is unfair.
to directly influence employee behavior through reward systems. An
organization’s reward system consists of its formal and informal mechanisms for defining the
kinds of behavior desired, evaluating performance, and rewarding good performance. Most
systems offer pay, benefits, and promotions when behavior meets or exceeds
performance standards. These rewards are called extrinsic because they are outside any
satisfaction obtained from the job itself.
A recent article in the Harvard Business Review ign
ited considerable debate by maintaining that
extrinsic rewards are not only ineffective but can actually undermine quality, job commitment,
and organizational citizenship. According to this view, incentives such as pay linked to output
to focus on the reward, rather than on the needs of the organization. Real
commitment requires the kind of leadership and organizational culture that foster positive
attitudes toward the organization, its objectives, and its customers. Furthermore, relianc
extrinsic rewards may undermine morale by causing employees to feel manipulated. When Emery
Air Freight instituted a system of management through positive reinforcement, productivity and
management skills improved, but managers initially faced resista
nce to the program. Later,
trainers at the company concluded that the resistance arose from employees’ belief they were
being manipulated. Consistent with this view, an analysis of 98 previously conducted studies
found training and goal setting had more im
pact on productivity than compensation linked to
Given these criticisms, why do managers continue to use rewards such as financial incentives? If
used appropriately, extrinsic rewards can support other efforts to influence motivation. When
ards are designed to enhance employees’ perception that they make a valued contribution,
they can build employee satisfaction. As at Nordstrom’s, such rewards are part of a culture and
management system in which contributing to the organization’s success i
s a source of pride and
accomplishment. Lantech, a manufacturer based in Louisville, Kentucky, uses a profit
not to induce certain behaviors but as fair payment for work performed. Lantech’s president
believes its employees it employees are mo
tivated by a culture in which they feel “empowered
and involved in continually improving our customer satisfaction.” With these limitations in mind,
managers wishing to devise an appropriate reward system should offer rewards that are valued,
d to desired behaviors, and perceived as equitable.
The Significance of L
A leader with a vision focuses followers on something bigger than themselves yet presented in a
way they can understand and remember. This is especially important
objectives are complex and obscure or have uncertain consequences. Distilling a complicated
situation into a clear vision distinguished Ronald Reagan as president.
The distinct role of leadership makes it significant for solving one of
the most fundamental
management problems: gaining employee commitment to fulfilling the organization’s mission and
achieving its objectives. Effective leadership can solve that problem when the leader has a
one that involves offering cu
stomers something unique and valuable, preparing
the organization to manage change, and drawing on the organization’s unique strengths.
How can the organization find leaders with a strategic vision? How can it create the conditions in
which its people can
be such leaders? How (if at all) can managers become such leaders? Many
theories of leadership have attempted to answer questions such as these. Unfortunately, there is
supported theory that broadly describes how leadership works. Most theories and
research have looked only at specific aspects of leadership, and the newest theories have not yet
undergone thorough testing. Until the field of leadership matures, managers are limited to
seeking clues from the various theories in their present state.
e leader’s role: If we view leadership as a meaning
making process, part of the process often
involves designating someone as the leader
perhaps even endowing that person with great power
to direct activities. The person chosen to lead is someone who can e
loquently represent the
meaning of the group. An example is Russian political leader Vladimir Zhirinovsky, called by Time
magazine “a touchstone for ordinary Russians’ deepest yearnings and darkest fears.” The leader
also is someone centrally involved in t
typically someone who has invested much time in
the group, occupies a high position, and is expert in what the group does. Thus, the leader’s
influence results from his or her work in the group rather than from the ability to get other people
ork in the group. This view is consistent with the idea that charismatic leadership depends in
part on the followers’ perceptions of the leader.
School of Geology and Petroleum Engineering
nvitation to Geology
Geology is the study of the earth
. Physical geology, in particular, is concerned with the materials
and physical features of the earth, changes in those features, and the processes that bring them
about. Intellectual curiosity about the way the earth works is one reason for the study of g
It is not an isolated discipline but draws on the principles of many other sciences. The earth is
challenging subject, for it is old, complex in composition and structure, and large in scale. Physical
geology focuses particularly on the physical fe
atures of the earth and how they have formed.
Observations suggest that, for the most part, those features are the result of many individually
small, gradual change continuing over long periods of time, punctured by occasional, unusual,
cataclysmic it’s fo
rmation, the events. Shortly after its formation, the earth underwent melting
and compositional differentiation into core, mantle, and crust.
There are also practical aspects to the study of geology. Certain geologic processes and events
can be hazardous,
and a better understanding of such phenomena may help us to minimize the
The scientific method in a means of discovering basic scientific principles. The systematic study
of the earth that constitutes the science of geology has existed as an organ
ized discipline for only
about250 years. It was first formally developed in Europe. Two principal opposing schools of
thought emerged in the eighteenth and nineteenth centuries to explain geologic observation. One,
popularized by James Hutton and later nam
ed by Charles Lyell , was the concept of
uniformitarianism. Uniformitarianism comprises the ideas that the surface of the earth has been
continuously and gradually changed and modified over the immense span of geologic time and
that, by studying the geolog
ic processes now active in shaping the earth. It is not assumed that
the rates of all processes have been the same throughout time, but rather that the nature of
processes in similar that the same physical principles operating in the present. The second,
ontrasting theory was catastrophism. The catastrophists, led by French scientist Georges Cuvier ,
believed that a series of immense, worldwide upheavals were the agents of change that, between
catastrophes, the earth was static. Violent volcanic eruptions
followed by torrential rains and
floods were invoked to explain mountains and valleys and to bury animal populations that later
became fossilized. In between those episodic global devastations, the earth’s surface did not
change, according to catastrophist
theory. Catastrophists also believed that entire plant and
animal populations were created a new after each such event, to be wholly destroyed by the next.
For all practical purposes, the earth is a closed system, meaning that the amount of matter in
d on the earth is fixed. No new elements are being added. There is, therefore, an ultimate limit
to how much of any metal we can exploit. There is also only so much land to live on.
The early atmosphere and oceans formed at the same time. heat from within
the earth and from
the sun together drive many of the internal and surface processes that have shaped and modified
the earth throughout its history and that continue to do so. The earliest life forms date back
several billion years. Organisms with hard pa
rts became widespread about 600 million years ago.
Humans only appeared 3 to 4 million years ago, but their large and growing numbers and
technological advances have had significant impacts on natural systems, some of which may not
readily be erased by slo
paced geological processes.
Minerals and Rocks
It is difficult to talk at length about geology without talking about rocks or the minerals of which
they are composed. All natural and most synthetic substances on earth are made from the 90
urally occurring chemical elements. An element is the simplest kind of chemical; it cannot be
broken down further by ordinary chemical or physical processes.
Chemical elements consist of atoms, which are, composed of protons, neutrons, and electrons.
opes are atoms of one element (having; therefore, the same number of protons) with
different numbers of neutrons; chemically, isotopes of one element and thus acquired a positive
or negative charge. Atoms of the same or different elements may bond together
. The most
common kinds of bonding in minerals are ionic (resulting from the attraction between oppositely
charged ions) and covalent (involving sharing or electrons between atoms). When atoms of two
or more different elements bond together, they form a co
The nucleus, at the center of the atom, contains the protons and neutrons; the electrons
move around the nucleus. The number of protons in the nucleus is unique to each element and
determines what chemical element that atom is. Every atom
of hydrogen contains one proton in
its nucleus; every carbon atom, six protons; every oxygen atom; eight protons; every uranium
two protons. The characteristic number of protons in the atomic number of the
In an electrically
neutral atom, the number of protons equals the number of electrons. The
negative charge of one electron just equals the positive charge of the proton.
Most atoms, however, can gain or lose electrons. When this happens, the atom acquires a
or negative electrical charge and is termed an ion. If it loses electrons, it becomes a
positively charged cation, as the number of protons exceeds the number of electrons. If it gains
electrons, the resulting ion has a negative electrical charge and is te
rmed an union.
A mineral is a naturally accruing, inorganic, solid element or compound. With a definite
composition (or range in composition) and a regular internal crystal structure. When appropriate
instruments for determining composition and crys
tal structure are unavailable, minerals can be
identified from a set of physical properties, including color, crystal form, cleavage or fracture,
hardness, luster, specific gravity, and others. Minerals are broadly divided into silicates and non
The silicates are subdivided into structural types(for example, chain silicates, sheet
silicates, framework, silicates) on the basis of how the silica tetrahedral are linked in each mineral.
Silicates may alternatively be grouped by compositional characte
ristics. The non silicates are
subdivided into several groups, each of which has some compositional characteristic in common.
Examples, include the carbonates (each containing the CO3 group), the sulfates (SO4 ), and the
Rocks are cohesive minera
l aggregates. Certain of their physical properties are a consequence of
the ways in which their constituent mineral grains are assembled. All rocks are part of the rock
cycle, through which hold rocks are continually being transformed into new ones. A cons
of this that no rocks have been preserved throughout earth’s history, and many early stages in
the development of one rock may have been erased by subsequent events.
A volcano is a vent through which magma, fragments of ro
ck and ash, and gases erupt, or the
structure built around the vent by such eruption. Most volcanic activity is concentrated near plate
boundaries. Active volcanoes send out smoke and steam and occasionally erupt. An erupting
volcano gushes out ash, molten
lava and smoke. Volcanoes form either at the edges of tectonic
plates, or at hot
spots in the earth’s crust. Volcanoes differ widely in eruptive style, and thus in
the kinds of dangers they present. Seafloor rift zones and hot spots are characterized by t
fluid, basaltic lavas. Subduction
zone volcanoes typically produce much more viscous, silica
charged andesitic magma, so, in addition to lava, they may emit large quantities of
pyroclastics and other deadly products like nuees ardente
s. Lava is perhaps the leats serious
hazard associated with volcanoes. It moves slowly, it can sometimes be predicted. The results of
explosive eruptions are less predictable and the eruptions themselves more sudden. One
secondary affect of volcanic erupti
ons, especially explosive ones, which occurs as a result of dust
and gases being thrown into the atmosphere and blocking incoming sunlight. Lava is not generally
life threatening. Most lava flows advance at speeds of at most a few kilometers an hour. So on
can evade the advancing lava readily even on foot. The lava will destroy or bury any property
over which it flows. Lava temperatures are typically over 500° C and may be over 1,400° C.
Pyroclastics are often more dangerous than lava flows. They may erup
t more suddenly.
Explosively, and spread faster and farther. Cinders and ash are examples of free
pyroclastics. Another special kind of pyroclastic outburst is a deadly, denser
air flow of mixed
hot gases and fine ash known as a nuee ardente,
from the French for ‘glowing cloud.” A nuee
ardente is very hot
temperatures can be over 1,000°C in the interior
and it can rush down the
slopes of the volcano at more than 100 kilometers per hour, charring everything in its path and
flattening trees an
d weak buildings.
The volcanic structure divided into following parts based on their eruptive patterns and
characteristic form, shield volcano, stratovolcano, dormant volcano, extinct volcano and active
volcano. When a volcano emits lava as well as pyrocl
astics, a concave
shaped composite volcano
or stratovolcano is built of alternating lava flows and beds of pyroclastics. Dormant volcano is a
volcano that is not now erupting but that has erupted within historic time and is considered likely
to do so in t
he future. A volcano that is erupting or is expected to erupt is an active volcano.
Shield volcano is a volcano in the shape of a flattened dome, broad and low, built by flows of very
fluid, basaltic lava. Extinct volcano is a volcano that is not presently
erupting and that is not
considered likely to do so in the future.
Precursors are changes observed in or near a volcano that herald an impending eruption. There
are several types of advance warnings of volcanic activity. A common one is seismic activity.
signs of potential volcanic activity include bulging and warming of the ground surface and
increased seismic activity. Volcanologists cannot yet predict the exact timing or type of eruption
very precisely, except insofar as they can anticipate erupt
ive style on the basis of historic records,
the nature of the products of previous eruptions, and tectonic setting.
A single volcanic eruption can have a global impact on climate, although the effect may be only
brief. Intense explosive eruptions put large
quantities of volcanic dust high into the atmosphere,
from which it may take years to settle. In the interim, it par
tially blocks out incoming sunlight,
thus causing measurable cooling. After Krakatoa’s 1883 eruption, worldwide temperatures
ly half a degree centigrade, and the cooling effects persisted for almost ten years.
The larger 1815 eruption of Tambora caused still more dramatic cooling. 1816 became known in
the Northern Hemisphere as the “year without a summer.” Such past experience f
orms the basis
for fears of a “nuclear winter” in the event of a nuclear war, for modern nuclear weapons are
powerful enough to cast volumes of fine dust into the air, and more dust and ash would be
generated by ensuing fires. The climatic impacts of volca
noes are not confined to the effects of
volcanic dust. The 1982 eruption of the Mexican volcano EI Chichon did not produce a particularly
large quantity of dust, but it did shoot volumes of unusually sulfur
rich gases into the atmosphere.
These gases produ
ced clouds of sulfuric acid droplets that spread around the earth. Not only do
the acid droplets block some sun
light, like dust, but in time they also settle back to the earth as
ld is the
The ability to determine the nume
rical ages of rocks has changed the way you think about the
world. But how can we determine the age of the Earth itself? Time earliest and preserved in the
Earth come from the great assemblage of most morphic and igneous rocks formed during
e. The oldest radiometric dates, about 4.4 billion years, have been obtained from
individual miner grains in sedimentary rocks from Australia. These grains
of the mineral zircon
show evidence of having experienced wet partial melting during the formati
on a magma, which
then crystallized into an igneous rock, which in turn was weathered, eroded and redeposited,
eventually to be incorporated into a sedimentary rock. Dates almost as old
4.0 billion years
have been obtained from granite igneous rocks fr
om Canada. The existence of such ancient rocks
proves that continental crust was present 4.0 billion years ago, while the 4.4 billion year old
mineral grains prove that the cycle of weathering, erosion, deposition, and cementation was
operating then. Beca
use we see wet melting and ancient sediment that was transported by water,
we know that there must have been water on the surface of the Earth at the time the sediments
These ancient rocks are all from the Archean eon. Recall that the
Hadean eon predates the
Archean. No rocks that might provide radiometric dates are preserved from early Hadean time
none that we have yet found, at any rate. How long did the Hadean eon last, and, therefore, how
much older might our planet be? Strong ev
idence from astronomy suggests that Earth formed at
the same time as the Moon, the other planets, and meteorites. Through radiometric dating, it has
been possible to determine the ages of meteorites and of Moon rocks brought back by astronauts.
The ages of
the most primitive of these objects cluster closely around 4.56 billion years. By
inference, the time of formation of Earth, and indeed of all the other planets and meteorites in the
solar system, is believed to be 4.56 billion years ago.
Metamorphism is change in rocks (short of complete melting) brought about by changes in
temperature, pressure, or chemical conditions. With progressive metamorphism, existing minerals
are commonly recrystallized, the crystals often growing lar
ger in the process, and minerals stable
at low temperatures and pressures may break down, to be replaced by other minerals stable at
grade conditions. Metamorphic rocks are subdivided into foliated and nonfoliated rocks.
Directed stress may also lea
d to formation of foliated rocks, in which elongated or platy minerals
assume a preferred orientation. Foliated rocks are named on the basis of their particular texture.
Nonfoliated rocks are most often named on the basis of mineralogic composition.
mphibolites is a metamorphic rock rich in amphiboles. Amphibolities are not
necessarily unfoliated rocks, for amphiboles commonly form in elongated or needlelike crystals
that may take on a preferred orientation in the presence of directed stress. Most met
either contact metamorphism, which occurs in country rock close to the contacts of invading
plutons and is characterized by relatively low
pressure mineral assemblages, or regional
metamorphism, which is caused principally by platetectonic act
ivity and emplacement of large
batholiths, and is characterized by elevated pressure as well as elevated temperature.
Metamorphic rocks are assigned to a particular facies, corresponding to a specific range of
pressures and temperatures, on the basis of th
e mineral assemblages they contain. Index
minerals are useful in assessing the general metamorphic grade of a rock and in determining
regional trends in metamorphic grade.
A variety of geologic settings and events lead to metamorphism. Most metamorphic
rocesses can be sub
divided into regional, contact, and fault
Regional metamorphism is, as its name implies, metamorphism on a grand scale, a
regional event. Regional metamorphism is commonly associated with mountain building events,
when large areas are uplifted, downwarped or stressed severely and deformed, as during plate
collisions. Rocks pushed to greater depths are subjected to increased pressures and
temperatures, and are metamorphosed. Collision adds directed stress, producing
lineated and foliated rocks. Regional metamorphism involving changes in both pressure and
temperature is also called dynamothermal metamorphism. The emplacement of large batholiths,
which may or may not be associated with mountain building, raises
crystal temperature over
broad areas as heat is released from cooling plutons, so batholith formation may likewise result in
metamorphism on a regional scale.
Contact metamorphism is named for the setting in which it occurs, near the contact of a
The pluton, emplaced from greater depths, is hotter than the country rock, and if it is
significantly hotter, the adjacent country rock is metamorphosed. The pluton then is surrounded
by a zone of metamorphic rock, also known as a contact aureole, or halo.
(The term aureole
comes from the Latin for “golden,” as a crown or halo might be.) Higher
metamorphic minerals are found close to the contact, lower
temperature minerals farther away.
Metasomatism may not occur in the contact aureole. Cont
act metamorphism, by definition, is a
more localized phenomenon than regional metamorphism, since it is confined to the immediate
environs of the responsible pluton. Contact
metamorphic effects also tend to be most marked
around plutons emplaced at shall
ow depths in the crust.
A metamorphic facies is a set of physical conditions that give rise to characteristic mineral
assemblages. That is rock of a particular metamorphic facies contain one or more minerals
indicative of a particular, restricted range of
pressures and temperatures. Contact
facies are the facies of low pressure and a range of temperatures. They consist of sanidinite
hornfels facies, hornblende
hornfels facies and zeolite facies. The zeolites are
hydrous silicates, stable only at low pressure and temperature. Regional
facies are characterized by elevated pressure and temperature. The greenschist facies is so
named because greenschist
facies rock commonly contain one or both of the g
chlorite and epidote. The blueschist facies is characterized by high pressure but low temperature.
It’s name derives from the several bluish silicates kyanite, an aluminum silicate, and that form
under these conditions.
Rocks subjected to stress may behave elastically or plastically Earthquakes result from
sudden rupture of brittle or elastic rocks, or sudden movement along fault zones in response to
stress. Most earthquakes are confined to the cold, rigid lithosphere.
up energy of an
earthquake is related through seismic waves, which include ground rupture and shaking, fire,
liquefaction, landslides, and tsunamis.
While earthquakes cannot be stopped, their negative effects can be limited by: seeking ways
cause locked faults to slip gradually and harmlessly, perhaps by using fluid injection to reduce
frictional resistance to shear; designing structures in active fault zones to be more resistant to
earthquake damage; identifying and, wherever possible, avoid
ing development in areas at
particular risk from earthquake
related hazards; increasing public awareness of and
preparedness for earthquakes in threatened areas; and learning enough about earthquake
precursor phenomena to make accurate and timely predict
ions of earthquakes.
Strain is deformation a change in shape, or volume, or both resulting from stress. It may be
either temporary or permanent, depending on the amount and type of stress and the ability of the
material to resist it. If the deformation is
elastic, the amount of deformation is proportional to the
stress applied, and the material returns to its original size and shape when the stress is removed.
A gently stretched rubber band shows elastic behavior. Rocks, too, may behave elastically,
gh much greater stress is needed to produce detectable strain. Once the elastic limit of a
material is reached, it may go through a phase of plastic deformation with increasing stress.
During this stage, relatively small added stresses yield large correspo
nding strains, and the
changes of shape are permanent. The material does not return to its original dimensions after
removal of the stress. A glassblower, an artist shaping clay, a carpenter fitting caulk into cracks
around a window, and a blacksmith shapi
ng a bar of hot iron into a horseshoe are all making use
of plastic behavior of materials. Faults and fractures come in all sizes, from microscopically small
to hundreds of kilometers long. Likewise, earthquakes come in all size, from tremors so small that
even sensitive instruments can barely detect them, to massive shocks that can level cities.
The point on a fault at which the first movement or break occurs during an earthquake is
called the earthquake’s focus, or hypocenter. In the case of a large eart
hquake, a section of fault
many kilometers long may slip, but there is always a point at which the first movement occurs,
and this is the focus. The point on the earth’s sur
face directly above the focus is the epicenter.
When an earthquake occurs, the sto
up energy is released in the form of seismic waves that
travel away from the focus. There are several types of seismic waves. Body waves (P waves and S
waves) travel through the interior of the earth. Surface waves, as their name suggests, travel
the surface. The use of body waves to explore the earth’s internal structure is explored P
waves are compressional waves. As P waves travel through matter, the matter is alternately
compressed and expanded. P waves travel through the earth, than, much as
sound waves travel
S waves are shear waves, involving a side
side sliding motion of material. Ground shaking
may cause a further problem in areas where the ground is very wet in filled land, near the coast,
or in places with a high water t
able. This problem is liquefaction. When wet soil is shaken by an
earthquake, the soil particles may be jarred apart, allowing water to seep in between them. This
greatly reduces the friction between soil particles that gives the soil strength, and it caus
ground to become somewhat like quicksand. When this happens, buildings can just topple over or
partially sink into the liquefied soil the soil has no strength to support them. The effects of
liquefaction were dramatically after a major earthquake in
Niigata. Apartment building tipped over
to settle at an angle of 30 degrees to the ground while the structure remained intact. In some
areas prone to liquefaction, improved underground drainage systems may be installed to try to
keep the soil drier, but l
ittle else can be done about this hazard beyond avoiding areas at risk. Not
all areas with wet soils are subject to liquefaction. The nature of the soil or fill plays a large role in
the extent of the danger.
Coastal areas, especially around the Pacific O
cean basin where so many large earthquakes
occur, may also be vulnerable to tsunamis. These are seismic sea waves, sometimes improperly
called “ tidal waves” although they have nothing to do with tides. When an undersea or near
shore earthquake occurs, sud
den movement of the sea floor may set up waves travelling away
from that spot, like ripples on a pond caused by a dropped pebble. Tsunamis can also be
triggered by major submarine landslides or by violent explosion of volcanoes in ocean basis. In
sea, the tsunami is only an unusually broad swell or ripple on the water surface. Like all
waves, tsunamis only develop into breakers as they approach shore and the undulating waters
touch bottom. The breakers associated with tsunamis, however, can easily
be over 15 meters
high and may reach up to 65 meters in the case of larger earthquakes. Several such breakers may
crash over the coast in succession: between waves, the water may be pulled swiftly seaward,
emptying a harbor or bay, and perhaps pulling unwa
ry onlookers along. Tsunamis can travel very
quickly speeds of 1,000 kilometers per hour are not uncommon and a tsunami set off on one side
of the Pacific may still cause noticeable effects o
n the other side of the ocean.
STRESS AND STRAIN
cussing rock deformation, geologists often use the word stress, which refers to the force
acting on a surface. The definition of pressure is exactly the same. However, the term stress often
refers to “differential stress, strain” that is, a situation in wh
ich the force acting on the surface of
a body is greater from one direction than from another. Pressure is commonly used to mean
“uniform stress, “in which the force on a body is equal in all directions. For example, the pressure
on a small body floating w
ithin a liquid is uniform
the same from all directions. Uniform stress is
also called confining pressure. A rock in the lithosphere is confined by the rocks all around it and
is uniformly stressed by those surrounding rocks. The related terms “lithostatic
“hydrostatic pressure” also describe uniform stress on a rock, but they convey additional
information about how the pressure is transmitted to the rock: by overlying rocks (lithostatic,
from lithos, the Greek root that means “rock”), or by wa
ter (hydrostatic, from hydro, the Greek
root that means “water”).
In response to stress, a rock will change its shape or its volume, sometimes both. This change is
called strain. Uniform stress causes rocks to change their volume. For example, if a rock is
subjected to uniform stress by being buried deep in the Earth, its volume will decrease. If the
spaces (pores) between the grains become smaller, or if the minerals in the rock are transformed
into more compact crystal structures, the volume change may be
relatively large. Differential
stress causes rocks to change their shape, and sometimes their volume as well.
There area several kinds of differential stress (Figure 8.1). Tension acts in a direction
perpendicular to and away a surface; this kind of stres
s pulls or stretches rocks. Compression acts
in a direction perpendicular to and toward a surface; compressional stress squeezes rocks,
shortening or squashing them and decreasing their volume. Shear stress acts parallel to a surface.
It causes rocks to ch
ange shape by bending, or breaking. In response to shear stress, different
parts of the rock may slide past each other like cards in a deck.
Geologists have identified approximately 3,500 minerals, but fewer than 30 of the
m are common
in the crust of the Earth. Why aren’t there more minerals in the Earth’s crust? The reason
becomes clear when we consider the relative abundances of the chemical elements in the Earth’
crust. Only 12 elements
oxygen, silicon, aluminum, iron,
calcium, magnesium, sodium,
potassium, titanium, hydrogen, manganese, and phosphorus
occur in the amounts greater than
0.1 percent (by weight). Together, these 12 elements make up more than 99 percent of the mass
of a limited number of minerals in which
one or more of these 12 abundant elements is an
essential ingredient. Minerals containing scarcer elements occur only in small amounts and only
under special circumstances.
oxygen and silicon
make up more than 70 percent of the crus
t in atomic by
weight. Oxygen itself constitutes more than 60 percent of the crust in atomic proportion
the actual number of atoms of oxygen in the crust
and more than 90 percent by volume.
Oxygen is a large, lightweight atom; not only are the
re lots of oxygen atoms in the crust, they
also take up a lot of space. Oxygen forms a simple anion, O
; compounds that contain this anion
. Oxygen and silicon together form an exceedingly strong anionic complex called
a silicon anion, (
; minerals that contain this anion are called
. Silicates are the
most abundant of all minerals; oxides are the second most abundant. Other mineral groups based
on different anions are less common.
EROSION BY WATER UNDER THE GROUND
Water can also cause erosion underneath the ground. As soon as rainwater infiltrates the ground
, it begins to react with the minerals in the regolith and the bedrock,
causing chemical weathering. Among the minerals of the Earth’s cru
st, the carbonates are most
readily dissolved. Carbonate rocks such as limestone are almost insoluble in pure water, but are
easily dissolved by carbonic acid, a common constituent of rainwater. The attack occurs mainly
along joints and other opening in th
e rock. When limestone weathers, it may be dissolved and
carried away in slowly moving groundwater. In some carbonate terrains, the rate of dissolution is
even faster than the average rate of erosion of surface materials by streams and mass wasting.
arbonate rock is dissolved by circulating groundwater, a cave may form.
dissolution cavities that are closed to the surface, or have only a small opening. Cave formation
begins with dissolution along interconnected fractures and bedding planes, w
here two different
sedimentary rock units meet. A passage eventually develops along the most favorable flow route.
The rate of cave formation is related to the rate of dissolution. As the passage grows and the flow
of groundwater becomes more rapid and tur
bulent, the rate of dissolution also tends to increase.
The development of a continuous passage by slowly moving groundwater may take up to 10,000
years, and enlargement of the passage to create a fully developed cave system may take as long
as a million
years. Terrains that are underlain by extensive cave systems are called
are dissolution cavities, like caves, but open to the sky. Some sinkholes are
formed when the roof of a cave collapses. Others are formed at the surface
, when rainwater is
freshly charged with carbon dioxide and hence is most effective as a solvent. Some sinkholes form
slowly; others form catastrophically. An example of the latter occurred in Winter Park, Florida, in
1972. In a period of just 10 hours, a
sinkhole developed and consumed part of a house, six
commercial buildings, several automobiles, and a municipal swimming pool. The total cost of the
damage was over $2 million. Events as dramatic as the Winter Park sinkhole are rare, but sinkhole
is a common occurrence in areas underlain by carbonate rocks.
EROSION BY WIND
Wind is an important agent of erosion, especially in arid and semiarid regions. Processes related
to wind are called
processes after Aeolus, the Greek god of wind
. Because the density of
air is far less than that of water, air cannot move as large a particle as water flowing at the same
velocity. In most regions with moderate to strong winds, the largest particles that can be lifted by
the air are grains of sand. O
nly the finest dust particles remain aloft long enough to be moved by
Flowing air erodes the land surface in two ways. The first,
, results from the impact
driven grains of sand (Figure 6.4). Airborne particles act like to
ols, chipping small
fragments off rocks that stick up from the surface. When rocks are abraded in this way they
acquire distinctive, curved shapes and a surface polish. A bedrock surface or stone that has been
abraded and shaped by wind
blown sediment is c
(“wind artifact”). The second
wind erosional process,
(from the Latin word meaning “to blow away”), occurs when
the wind picks up and removes loose particles of sand and dust (Figure 6.5). Deflation on a large
scale takes place
only where there is a little or no vegetation and loose particles are fine enough
to be picked up by the wind. It is especially severe in deserts, but can occur elsewhere during
times of drought when no moisture is present to hold soil particles together.
School of Mechanical Engineering
of Motor V
Friction causes heat and wear. In an engine, oil lubricates the moving parts and reduces the heat
and the wear. The oil also collects any small particles of dirt or metal and carries
them to the oil
Some of the oil will leak out of the engine when it is used. The amount of oil in the engine will
need checking regularly. The dipstick is used for checking the amount of oil. If there isn’t enough
oil in the engine, friction betwe
en the moving parts will increase and the engine will quickly
The oil in the engine will need changing about once every 5000 km. If it is not changed, it will
become thin and full of impurities and it will not lubricate efficiently. The oil
filter will also need
changing regularly. If it is not changed, it will become blocked by particles of dirt and metal. If
the filter becomes blocked, the oil will not flow around the engine and heat and water will
increase very rapidly.
Some parts of a c
ar need greasing
usually about once every six months. Fifty years ago cars
needed greasing every week. Modern vehicles need much less greasing. They only need greasing
about twice a year. Cars in the future will probably need no greasing.
In gas welding, it is necessary to use a mixture of two gases. To create a hot enough flame, a
combustible gas must be mixed with oxygen. Although acetylene (C2H2) is normally used, the
combustible gas need not be acetylene. Hydrogen or petroleum
gases can also be used.
Oxygen can be stored at very high pressure. It is dangerous to compress gaseous acetylene in the
same way and so it is dissolved under pressure in liquid acetone but at a much lower pressure
than oxygen. To create a suitable flame,
the gases must be supplied to the welding torch at low
pressure. Pressure regulators are therefore used to regulate the gas flow from the cylinders. They
are screwed into the top of each cylinder.
Gas welding is normally used to join steel to steel. To ma
ke a very strong joint, the work pieces
must be composed of the same metal. Welding rods are used to provide filler metal. In gas
welding, these rods are generally composed of steel. Bronze or brass rods may sometimes be
used. When bronze and brass filler
metal is used the process is called brazing.
To light the welding torch, the combustible gas must be turned on first. The oxygen must not be
turned on before the flame is lit. The oxygen supply must be adjusted to give the correct flame.
struments in a C
All vehicles require certain instruments to provide information for the driver. For instance, every
car has a speedometer to indicate its speed. It also has a fuel gauge to indicate the amount of
fuel in the petrol tank. Many cars also h
ave a tachometer to indicate the engine speed. They may
also have an ammeter to indicate if the battery is charging or discharging.
The speedometer is indicating zero kph. The car is not moving. The engine is turning at minimum
speed (approximately 750 r
pm). As the engine is only turning slowly, the alternator is also
turning slowly. It is not producing enough current for the engine. Therefore, the battery must
supply some of the necessary current. The battery discharging and so the ammeter is indicating
If the car is moving at 60kph, the engine is turning at 2500 rpm and so the alternator is turning
quite fast. It is producing a strong current for the engine and so the battery is no longer needed
to supply current. The battery is now recharging
from the alternator and so the ammeter is
indicating +10A. after a short time, the battery will be fully charged again.
If the car is moving at 90kph, the engine is turning at a speed of 4500 rpm. However, the
alternator is not producing any current. Th
e ammeter is indicating
20A. In other words, the
battery is discharging rapidly although the engine is turning at high speed. Therefore, the
alternator is not producing any power and the battery is discharging at 20A. So, unless the fault is
put right or
the engine stopped, the battery will soon become completely discharged. The
electrical items, such as the headlights, should be switched off as soon as possible. When they
are switched off and the engine is stopped the ammeter will read zero and the needle
A car battery can easily become discharged if there is an electrical fault in the car. If the fan belt
is broken, for instance, the battery may become discharged in quite a short time. If the lights are
t on while the car is not in use, the battery will also become discharged.
A battery (d.c.) cannot be recharged directly from the mains (a.c.). A battery charger is needed to
rectify the a.c. to d.c. and to reduce the voltage to 12V. Before charging the b
attery, remove all
the filler plugs. While battery is charging, hydrogen will be produced. This gas cannot escape
easily from the battery if the filler plugs are not removed.
When connecting the crocodile clips to the battery, check the connections. The p
ositive clip must
be connected to the positive terminal and the negative clip to the negative terminal. Make sure
the clips are connected before switching on the charger. After charging, switch off the charger
before disconnecting the clips.
ed eight hours ago. During the first hour, the ammeter needle was indicating 5A.
(the battery was being charged at the maximum rate). During the second and third hours, the
ammeter was indicating about 4.5A. During the next two hours, the charging rate was
more rapidly. After five hours, the rate was only 2A. After eight hours, the ammeter is now
indicating 0.5A. The battery is almost fully charged. It will be fully charged in about an hour from
Energy Conversion P
Fuel and o
xygen are converted to heat energy by combustion. The heat created during the
combustion process causes the gases trapped inside the cylinder to expand. This expansion
causes a pressure build
up, which is then converted to mechanical energy as the expandin
force a piston down the cylinder.
down movement of the piston is converted to rotary motion by a connecting rod and
crank. This is like the rider’s legs and the chain wheel of a bicycle.
The energy of motion and of vehicle movement is
called kinetic energy. To stop a vehicle this
energy must be converted to another form. The brakes do this by converting kinetic energy into
heat. When all the kinetic energy has been converted the vehicle is stationary.
The internal combustion engine is
not a very efficient energy converter, as it can not turn all the
fuel into mechanical energy. Surprisingly, much of the fuel is wasted in the form of heat, either
down the exhaust pipe with the waste gases, or absorbed by the cooling system and radiated
the atmosphere. Only some 25 percent of the chemical energy fed into the engine is used to drive
As the piston moves up and down the cylinder it must stop at the top and bottom every time it
changes directions. These points are known as to
centre and bottom dead
distance travelled by the piston between top dead
centre and bottom dead
centre. The distance
travelled by the piston between top dead
centre and bottom dead
centre is called the stroke. The
diameter of the cylinde
r is called the bore.
The crankshaft of an engine is similar to the cranks on a bicycle. The rider’s feet push on the
pedals, which turn the cranks mounted on the centre spindle, converting the up
movement of the legs into rot
ary motion. In that way a pushing effort is converted into a turning
force called torque.
The piston in an engine is connected to the crankshaft by the connecting rod. In much the same
way as the bicycle, the up
down movement of the piston is convert
ed into the rotary torque
as the crankshaft. Because far greater forces are being converted, all the components are much
stronger, and the crankshaft is supported in more bearings.
The crankshaft is normally a robust, one
piece alloy steel forging machine
d to very fine
tolerances. Some manufacturers use steel alloys or cast iron containing copper, chromium and
nickel. Cast iron crankshafts have proved to be very durable; they have good wearing properties
and are less prone to fatigue than forged steel shaf
ts. The journals may be hardened by
processes such as nitriding or induction hardening.
The crankshaft has a number of identifiable parts:
Main bearing journal.
Any part of the shaft that rotates in a bearing is called a journal.
The main bearing journals
support the shaft in the cylinder block.
Crank pin journal.
This is the part of the crankshaft to which the connecting rod is
attached, and is often called the big
This is the term used to describe the offset from the main journ
als to the
crank pin; it is like the length of the pedal crank on a cycle. In the same way as the cycle
rider’s foot moves two crank lengths from highest to lowest position, so the piston moves
an amount that is twice the crank offset. This is the stroke o
f an engine.
end journals and the main bearing journals are held together by the
webs, which may also incorporate counterbalance weights.
A sharp corner in this position would create a weak spot, so a radius is
o avoid any problems.
cylinder engine has a single
throw crankshaft, while a four
engine would have a four
throw crankshaft. However, engines of ‘vee’ configuration often
end journals between two opposing cylinder
This describes how far the centre of the big
end journal is offset from
the centre of the crankshaft main journal: the larger this measurement, the greater the
turning force applied to the crankshaft while increasing the piston‘s effe
To supply oil to the big
end journals the crankshaft has internal
oilways drilled from the adjacent main bearing journal. Oil flows into main bearings from
the oil gallery, and from there it is fed along the crankshaft oilw
ays to each of the big
One end of the crankshaft forms a boss to which the flywheel
is attacked. The other end usually has some form of key way machined into it to provide a
positive drive for the timing gears, sprockets
or pulleys. Pulleys for auxiliary drives may
also need to be mounted there.
At both ends of the shaft some form of oil sealing must be used to prevent leakage from the
revolving journals. The scroll or quick thread ‘screws’ the oil back towards the inside
engine. At the same time, the centrifugal force of the spinning crankshaft forces oil to climb the
thrower. When it reaches the edge it is thrown off into a channel and returns to the sump.
The cover at the timing gear end usually has a lipped sea
l, made from synthetic rubber stiffened
by a metal shell. It has an inner lip that rubs on the crankshaft to stop oil leakage. Light contact is
maintained by the use of a steel garter spring.
Most of the very earlie
st internal combustion engines of the 17
centuries can be
classified as atmospheric engines. These were large engines with a single piston and cylinder, the
cylinder being open on the end. Combustion was initiated in the open cylinder using any
various fuels which were available. Gunpowder was often used as the fuel. Immediately after
combustion, the cylinder would be full of hot exhaust gas at atmospheric pressure. At this time,
the cylinder end was closed and the trapped gas was allowed
to cool. As the gas cooled, it
created a vacuum within the cylinder. This caused a pressure differential across the piston,
atmospheric pressure on one side and a vacuum on the other. As the piston moved because of
this pressure differential, it would do w
ork by being connected to an external system, such as
raising a weight.
Some early steam engines also were atmospheric engines. Instead of combustion, the open
cylinder was filled with hot steam. The end was then closed and the steam was allowed to cool
nd condense. This created the necessary vacuum.
In addition to a great amount of experimentation and development in Europe and the US during
the middle and latter half of the 1800s, two other technological occurrences during this time
stimulated the emerg
ence of the internal combustion engine. In 1859, the discovery of crude oil
in Pennsylvania finally made available the development of reliable fuels which could be used in
these newly developed engines. Up to this time, the lack of good, consistent fuels w
as a major