hydraulic pump

Answer the following Question:

1- Define the hydraulic pump? and state its function?

2- What are the properties of the non–positive displacement pump?

3- What are the main types of positive displacement pump?

4- What are the advantages of positive displacement pump?

5- State the main properties of external gear pump?

6- State the advantages and disadvantages of external gear pump?

7- State the main properties of internal gear pump?

8- State the advantages and disadvantages of internal gear pump?

9- State the advantages and disadvantages of gerotor gear pump?

10- State the advantages and disadvantages of Lobe gear pump?

11- State the main properties of vane pump?

12- State the advantages and disadvantages of vane pump?

13- State the main properties of bent axis piston pump?

14- State the main properties of swash plate piston pump?

15- State the main properties of radial piston pump?

16- State factors affecting on pump performance?

17- State the major aspects in the selection of pumps?

The Critical State Model

The Critical State Model

The critical state concept was introduced in §1.8 in general terms. We are now in a

position to set up a model for critical state behaviour, postulating the existence of an ideal

material that flows as a frictional fluid at constant specific volume v when, and only when,

the effective spherical pressure p and axial-deviator stress q satisfy the eqs. (5.22

bis) and

q = Mp

v = Γ − λ ln p (5.23 bis).

 Fig. Associated Flow for Soil at Critical StaThis concept was stated in 1958 by Roscoe, Schofield and Wroth4 in a slightly

different form, but the essential ideas are unaltered. Two hypotheses are distinguished: first

is the concept of yielding of soil through progressively severe distortion, and second is the

concept of critical states approached after severe distortion. Two levels of difficulty are

recognized in testing these hypotheses: specimens yield after a slight distortion when the

magnitudes of parameters (p, v, q) as determined from mean conditions in a specimen can

be expected to be accurate, but specimens only approach the critical state after severe

distortion and (unless this distortion is a large controlled shear distortion) mean conditions

in the specimen can- not be expected to define accurately a point on the critical state line.

It seems to us that the simple critical state concept has validity in relation to two

separate bodies of engineering experience. First, it gives a simple working model that, as

we will see in the remainder of this chapter, provides a rational basis for discussion of

plasticity index and liquid limit and unconfined compression strength; this simple model is

valid with the same accuracy as these widely used parameters. Second, the critical state

concept forms an integral part of more sophisticated models such as Cam-clay, and as such

it has validity in relation to the most highly accurate data of the best axial tests currently

available. Certain criticisms5,6 of the simple critical state concept have drawn attention to

the way in which specimens ‘fail’ before they reach the critical state: we will discuss

failure in chapter 8.

The error introduced in the early application of the associated flow rule in soil

mechanics can now be cleared up. It was wrongly supposed that the critical state line in

Fig. 6.9(a) was a yield curve to which a normal vector could be drawn in the manner of

§2.10: such a vector would predict very large volumetric dilation rates

v& p vε& = M.However, we have seen that the set of points that lie along the critical state line

are not on one yield curve: through each critical state point we can draw a segment of a

yield curve parallel to the p-axis in Fig. 6.9(b). Hence it is correct to associate a flow

vector which has with each of the critical states. At any critical state very large

distortion can occur without change of state and it is certainly not possible to regard the

move from one critical state to an adjacent critical state as only a neutral change: the

critical state curve is not a yield curve.

Steady state theory

An alternate to the critical state concept is the steady state concept.
The steady state strength is defined as the shear strength of the soil when it is at the steady state condition. The steady state condition is defined as "that state in which the mass is continuously deforming at constant volume, constant normal effective stress, constant shear stress, and constant velocity." Steve Poulos built off a hypothesis that was formulating towards the end of his careerSteady state based soil mechanics is sometimes called "Harvard soil mechanics". It is not the same as the "critical state" condition.
The steady state occurs only after all particle breakage if any is complete and all the particles are oriented in a statistically steady state condition and so that the shear stress needed to continue deformation at a constant velocity of deformation does not change. It applies to both the drained and the undrained case.
The steady state has a slightly different value depending on the strain rate at which it is measured. Thus the steady state shear strength at the quasi-static strain rate (the strain rate at which the critical state is defined to occur at) would seem to correspond to the critical state shear strength. However there is an additional difference between the two states. This is that at the steady state condition the grains position themselves in the steady state structure, whereas no such structure occurs for the critical state. In the case of shearing to large strains for soils with elongated particles, this steady state structure is one where the grains are oriented (perhaps even aligned) in the direction of shear. In the case where the particles are strongly aligned in the direction of shear, the steady state corresponds to the "residual condition."
Two common misconceptions regarding the steady state are that a) it is the same as the critical state and b) that it applies only to the undrained case. A primer on the Steady State theory can be found in a report .Its use in earthquake engineering is described in detail in another publication.

Direct shear test

A direct shear test is a laboratory test used by geotechnical engineers to find the shear strength parameters of soil. The U.S. and U.K. standards defining how the test should be performed are ASTM D 3080 and BS 1377-7:1990 respectively.

The test is performed on three or four specimens from a relatively undisturbed soil sample. A specimen is placed in a shear box which has two stacked rings to hold the sample; the contact between the two rings is at approximately the mid-height of the sample. A confining stress is applied vertically to the specimen, and the upper ring is pulled laterally until the sample fails, or through a specified strain. The load applied and the strain induced is recorded at frequent intervals to determine a stress-strain curve for the confining stress.

Direct Shear tests can be performed under several conditions. The sample is normally saturated before the test is run, but can be run at the in-situ moisture content. The rate of strain can be varied to create a test of undrained or drained conditions, depending whether the strain is applied slowly enough for water in the sample to prevent pore-water pressure buildup.

Several specimens are tested at varying confining stresses to determine the shear strength parameters, the soil cohesion (c) and the angle of internal friction (commonly friction angle) (φ). The results of the tests on each specimen are plotted on a graph with the peak (or residual) stress on the x-axis and the confining stress on the y-axis. The y-intercept of the curve which fits the test results is the cohesion, and the slope of the line or curve is the friction angle.

Drained shear strength

The drained shear strength is the shear strength of the soil when pore fluid pressures, generated during the course of shearing the soil, are able to dissipate during shearing. It also applies where no pore water exists in the soil (the soil is dry) and hence pore fluid pressures are negligible. It is commonly approximated using the Mohr-Coulomb equation. (It was called "Coulomb's equation" by Karl von Terzaghi in 1942.) (Terzaghi 1942) combined it with the principle of effective stress.
In terms of effective stresses, the shear strength is often approximated by:
τ = σ' tan(φ') + c'
Where σ' =(σ - u), is defined as the effective stress. σ is the total stress applied normal to the shear plane, and u is the pore water pressure acting on the same plane.
φ' = the effective stress friction angle, or the'angle of internal friction' after Coulomb friction. The coefficient of friction μ is equal to tan(φ'). Different values of friction angle can be defined, including the peak friction angle, φ'_p, the critical state friction angle, φ'_cv, or residual friction angle, φ'_r.
c' = is called cohesion, however, it usually arises as a consequence of forcing a straight line to fit through measured values of (τ,σ')even though the data actually falls on a curve. The intercept of the straight line on the shear stress axis is called the cohesion. It is well known that the resulting intercept depends on the range of stresses considered: it is not a fundamental soil property. The curvature (nonlinearity) of the failure envelope occurs because the dilatancy of closely packed soil particles depends on confining pressure.

Critical state theory

Critical state soil mechanics

A more advanced understanding of the behaviour of soil undergoing shearing lead to the development of the critical state theory of soil mechanics (Roscoe, Schofield & Wroth 1958). In critical state soil mechanics, a distinct shear strength is identified where the soil undergoing shear does so at a constant volume, also called the 'critical state'. Thus there are three commonly identified shear strengths for a soil undergoing shear:

• Peak strength τ_p
• Critical state or constant volume strength τ_cv
• Residual strength τ_r

The peak strength may occur before or at critical state, depending on the initial state of the soil particles being sheared:

• A loose soil will contract in volume on shearing, and may not develop any peak strength above critical state. In this case 'peak' strength will coincide with the critical state shear strength, once the soil has ceased contracting in volume. It may be stated that such soils do not exhibit a distinct 'peak strength'.
• A dense soil may contract slightly before granular interlock prevents further contraction (granular interlock is dependent on the shape of the grains and their initial packing arrangement). In order to continue shearing once granular interlock has occurred, the soil must dilate (expand in volume). As additional shear force is required to dilate the soil, a 'peak' strength occurs. Once this peak strength caused by dilation has been overcome through continued shearing, the resistance provided by the soil to the applied shear stress reduces (termed "strain softening"). Strain softening will continue until no further changes in volume of the soil occur on continued shearing. Peak strengths are also observed in overconsolidated clays where the natural fabric of the soil must be destroyed prior to reaching constant volume shearing. Other effects that result in peak strengths include cementation and bonding of particles.

The constant volume (or critical state) shear strength is said to be intrinsic to the soil, and independent of the initial density or packing arrangement of the soil grains. In this

Triaxial shear test

A triaxial shear test is a common method to measure the mechanical properties of many deformable solids, especially soil, sand, clay, and other granular materials or powders. There are several variations on the test, discussed below.

Basic Concept

For loose granular materials like sand or gravel, the material is contained in a cylindrical latex sleeve with a flat, circular metal plate or platen closing off the top and bottom ends. This cylinder is placed into a bath of water to provide pressure along the sides of the cylinder. The top platen can then be mechanically driven up or down along the axis of the cylinder to squeeze the material. The distance that the upper platen travels is measured as a function of the force required to move it, as the pressure of the surrounding water is carefully controlled. The net change in volume of the material is also measured by how much water moves in or out of the surrounding bath.
The principle behind a triaxial shear test is that the stress applied in the vertical direction (along the axis of the cylinder) can be different than the stress applied in the horizontal directions (along the sides of the cylinder). This produces a non-hydrostatic stress state, which contains shear stress.
A solid is defined as a material that can support shear stress without moving. However, every solid has an upper limit to how much shear stress it can support. The triaxial tester is designed to measure that limit. The stress on the platens is increased until the material in the cylinder fails and forms sliding regions within itself, known as shear bands. A motion where a material is deformed under shear stress is known as shearing. The geometry of the shearing in a triaxial tester typically causes the sample to become shorter while bulging out along the sides. The stress on the platen is then reduced and the water pressure pushes the sides back in, causing the sample to grow taller again. This cycle is usually repeated several times while collecting stress and strain data about the sample.
During the shearing, a granular material will typically have a net gain or loss of volume. If it had originally been in a dense state, then it typically gains volume, a characteristic known as Reynolds' dilatancy. If it had originally been in a very loose state, then contraction may occur before the shearing begins or in conjunction with the shearing.
From the triaxial test data, it is possible to extract fundamental material parameters about the sample, including its angle of shearing resistance, apparent cohesion, and dilatancy angle. These parameters are then used in computer models to predict how the material will behave in a larger-scale engineering application. An example would be to predict the stability of the soil on a slope, whether the slope will collapse or whether the soil will support the shear stresses of the slope and remain in place. Triaxial tests are used along with other tests to make such engineering predictions.

Types of Triaxial Tests

There are several variations on the basic concept of triaxial testing. These are given the following labels (corresponding test standard in parentheses):

• CD — Consolidated drained
• CU — Consolidated undrained
• UU — Unconsolidated undrained

Factors Controlling Shear Strength of Soils

Factors Controlling Shear Strength of Soils

The stress-strain relationship of soils, and therefore the shearing strength, is affected by:

1. soil composition (basic soil material): mineralogy, grain size and grain size distribution, shape of particles, pore fluid type and content, ions on grain and in pore fluid.
2. state (initial): Defined by the initial void ratio, effective normal stress and shear stress (stress history). State can be described by terms such as: loose, dense, overconsolidated, normally consolidated, stiff, soft, contractive, dilative, etc.
3. structure: Refers to the arrangement of particles within the soil mass; the manner the particles are packed or distributed. Features such as layers, joints, fissures, slickensides, voids, pockets, cementation, etc, are part of the structure. Structure of soils is described by terms such as: undisturbed, disturbed, remolded, compacted, cemented; flocculent, honey-combed, single-grained; flocculated, deflocculated; stratified, layered, laminated; isotropic and anisotropic.
4. Loading conditions: Effective stress path, i.e., drained, and undrained; and type of loading, i.e., magnitude, rate (static, dynamic), and time history (monotonic, cyclic)).

Undrained strength

This term describes a type of shear strength in soil mechanics as distinct from drained strength.
Conceptually, there is no such thing as the undrained strength of a soil. It depends on a number of factors, the main ones being:

• Orientation of stresses
• Stress path
• Rate of shearing
• Volume of material (like for fissured clays or rock mass)

Undrained strength is typically defined by Tresca theory, based on Mohr's circle as:
σ₁ - σ₃ = 2 S_u
Where:
σ₁ is the major principal stress
σ₃ is the minor principal stress
τ is the shear strength (σ₁ - σ₃)/2
hence, τ = S_u (or sometimes c_u), the undrained strength.
It is commonly adopted in limit equilibrium analyses where the rate of loading is very much greater than the rate at which pore water pressures, that are generated due to the action of shearing the soil, may dissipate. An example of this is rapid loading of sands during an earthquake, or the failure of a clay slope during heavy rain, and applies to most failures that occur during construction.
As an implication of undrained condition, no elastic volumetric strains occur, and thus Poisson's ratio is assumed to remain 0.5 throughout shearing. The Tresca soil model also assumes no plastic volumetric strains occur. This is of significance in more advanced analyses such as in finite element analysis. In these advanced analysis methods, soil models other than Tresca may be used to model the undrained condition including Mohr-Coulomb and critical state soil models such as the modified Cam-clay model, provided Poisson's ratio is maintained at 0.5.
One relationship used extensively by practicing engineers is the empirical observation that the ratio of the undrained shear strength c to the effective confining stress p' is approximately a constant for a given Over Consolidation Ratio (OCR), and varies linearly with the logarithm of the OCR. This idea was systematized in the empirical SHANSEP (stress history and normalized soil engineering properties) method.(Ladd & Foott 1974). This relationship can also be derived from both critical-state^{[citation needed]} and steady-state soil mechanics^{[citation needed]}.

 

Shear strength (soil)

For a general description of shear strength, shear strength.

Typical stress strain curve for a drained dilatant soil

Shear strength is a term used in soil mechanics to describe the magnitude of the shear stress that a soil can sustain. The shear resistance of soil is a result of friction and interlocking of particles, and possibly cementation or bonding at particle contacts. Due to interlocking, particulate material may expand or contract in volume as it is subject to shear strains. If soil expands its volume, the density of particles will decrease and the strength will decrease; in this case, the peak strength would be followed by a reduction of shear stress. The stress-strain relationship levels off when the material stops expanding or contracting, and when interparticle bonds are broken. The theoretical state at which the shear stress and density remain constant while the shear strain increases may be called the crtical state, steady state, or residual strength.

A critical state line separates the dilatant and contractive states for soil

The volume change behavior and interparticle friction depend on the density of the particles, the intergranular contact forces, and to a somewhat lesser extent, other factors such as the rate of shearing and the direction of the shear stress. The average normal intergranular contact force per unit area is called the effective stress.

If water is not allowed to flow in or out of the soil, the stress path is called an undrained stress path. During undrained shear, if the particles are surrounded by a nearly incompressible fluid such as water, then the density of the particles cannot change without drainage, but the water pressure and effective stress will change. On the other hand, if the fluids are allowed to freely drain out of the pores, then the pore pressures will remain constant and the test path is called a drained stress path. The soil is free to dilate or contract during shear if the soil is drained. In reality, soil is partially drained, somewhere between the perfectly undrained and drained idealized conditions.

The shear strength of soil depends on the effective stress, the drainage conditions, the density of the particles, the rate of strain, and the direction of the strain.

For undrained, constant volume shearing, the Tresca theory may be used to predict the shear strength, but for drained conditions, the Mohr–Coulomb theory may be used. critical state theory or the related steady state theory can account for the predominant effects of drainage conditions, effective stress, and consolidation on the shear strength at large strains (i.e., at the critical state or steady state). There are some key differences between the steady state and critical state theories.

Models and theories associated with crisis management

Crisis Management Model

Successfully defusing a crisis requires an understanding of how to handle a crisis – before they occur. Gonzalez-Herrero and Pratt found the different phases of Crisis Management.
There are 3 phases in any Crisis Management are as below
1 The diagnosis of the impending trouble or the danger signals
2. Choosing appropriate Turnaround Strategy
3 Implementation of the change process and its monitoring.

] Management Crisis Planning

No corporation looks forward to facing a situation that causes a significant disruption to their business, especially one that stimulates extensive media coverage. Public scrutiny can result in a negative financial, political, legal and government impact. Crisis management planning deals with providing the best response to a crisis.^[10]

Contingency planning

Preparing contingency plans in advance, as part of a crisis management plan, is the first step to ensuring an organization is appropriately prepared for a crisis. Crisis management teams can rehearse a crisis plan by developing a simulated scenario to use as a drill. The plan should clearly stipulate that the only people to speak publicly about the crisis are the designated persons, such as the company spokesperson or crisis team members. The first hours after a crisis breaks are the most crucial, so working with speed and efficiency is important, and the plan should indicate how quickly each function should be performed. When preparing to offer a statement externally as well as internally, information should be accurate. Providing incorrect or manipulated information has a tendency to backfire and will greatly exacerbate the situation. The contingency plan should contain information and guidance that will help decision makers to consider not only the short-term consequences, but the long-term effects of every decision.^[10]

] Business continuity planning

When a crisis will undoubtedly cause a significant disruption to an organization, a business continuity plan can help minimize the disruption. First, one must identify the critical functions and processes that are necessary to keep the organization running. Then each critical function and or/process must have its own contingency plan in the event that one of the functions/processes ceases or fails. Testing these contingency plans by rehearsing the required actions in a simulation will allow for all involved to become more sensitive and aware of the possibility of a crisisis. As a result, in the event of an actual crisis, the team members will act more quickly and effectively.^[10]

Structural-functional systems theory

Providing information to an organization in a time of crisis is critical to effective crisis management. Structural-functional systems theory addresses the intricacies of information networks and levels of command making up organizational communication. The structural-functional theory identifies information flow in organizations as "networks" made up of members and "links". Information in organizations flow in patterns called networks.^[11]

Diffusion of innovation theory

Another theory that can be applied to the sharing of information is Diffusion of Innovation Theory. Developed by Everett Rogers, the theory describes how innovation is disseminated and communicated through certain channels over a period of time. Diffusion of innovation in communication occurs when an individual communicates a new idea to one or several others. At its most elementary form, the process involves: (1) an innovation, (2) an individual or other unit of adoption that has knowledge of or experience with using the innovation, (3) another individual or other unit that does not yet have knowledge of the innovation, and (4) a communication channel connecting the two units. A communication channel is the means by which messages get from one individual to another.

Role of apologies in crisis management

There has been debate about the role of apologies in crisis management, and some argue that apology opens an organization up for possible legal consequences. "However some evidence indicates that compensation and sympathy, two less expensive strategies, are as effective as an apology in shaping people’s perceptions of the organization taking responsibility for the crisis because these strategies focus on the victims’ needs. The sympathy response expresses concern for victims while compensation offers victims something to offset the suffering."^[12]

Crisis leadership

James identifies six leadership competencies which facilitate organizational restructuring during and after a crisis.

1. Building an environment of trust
2. Reforming the organization’s mindset
3. Identifying obvious and obscure vulnerabilities of the organization
4. Making wise and rapid decisions as well as taking courageous action
5. Learning from crisis to effect change.

Crisis leadership research concludes that leadership action in crisis reflects the competency of an organization, because the test of crisis demonstrates how well the institution’s leadership structure serves the organization’s goals and withstands crisis. ^[8] Developing effective human resources is vital when building organizational capabilities through crisis management executive leadership.^[13]

Unequal human capital theory

James postulates that organizational crisis can result from discrimination lawsuits. ^[14] James’s theory of unequal human capital and social position derives from economic theories of human and social capital concluding that minority employees receive fewer organizational rewards than those with access to executive management. In a recent study of managers in a Fortune 500 company, race was found to be a predictor of promotion opportunity or lack thereof.^[15] Thus, discrimination lawsuits can invite negative stakeholder reaction, damage the company's reputation, and threaten corporate survival.

Examples of successful crisis management

Tylenol (Johnson and Johnson)

In the fall of 1982, a murderer added 65 milligrams of cyanide to some Tylenol capsules on store shelves, killing seven people, including three in one family. Johnson & Johnson recalled and destroyed 31 million capsules at a cost of $100 million. The affable CEO, James Burke, appeared in television ads and at news conferences informing consumers of the company's actions. Tamper-resistant packaging was rapidly introduced, and Tylenol sales swiftly bounced back to near pre-crisis levels.^[16]
When another bottle of tainted Tylenol was discovered in a store, it took only a matter of minutes for the manufacturer to issue a nationwide warning that people should not use the medication in its capsule form.^[17]

Odwalla Foods

When Odwalla's apple juice was thought to be the cause of an outbreak of E. coli infection, the company lost a third of its market value. In October 1996, an outbreak of E. coli bacteria in Washington state, California, Colorado and British Columbia was traced to unpasteurized apple juice manufactured by natural juice maker Odwalla Inc. Forty-nine cases were reported, including the death of a small child. Within 24 hours, Odwalla conferred with the FDA and Washington state health officials; established a schedule of daily press briefings; sent out press releases which announced the recall; expressed remorse, concern and apology, and took responsibility for anyone harmed by their products; detailed symptoms of E. coli poisoning; and explained what consumers should do with any affected products. Odwalla then developed - through the help of consultants - effective thermal processes that would not harm the products' flavors when production resumed. All of these steps were communicated through close relations with the media and through full-page newspaper ads.^[18]

Mattel

Mattel Inc., the toy maker, has been plagued with more than 28 product recalls and in Summer of 2007, amongst problems with exports from China, faced two product recall in two weeks. The company "did everything it could to get its message out, earning high marks from consumers and retailers. Though upset by the situation, they were appreciative of the company's response. At Mattel, just after the 7 a.m. recall announcement by federal officials, a public relations staff of 16 was set to call reporters at the 40 biggest media outlets. They told each to check their e-mail for a news release outlining the recalls, invited them to a teleconference call with executives and scheduled TV appearances or phone conversations with Mattel's chief executive. The Mattel CEO Robert Eckert did 14 TV interviews on a Tuesday in August and about 20 calls with individual reporters. By the week's end, Mattel had responded to more than 300 media inquiries in the U.S. alone."^[19]

 Pepsi

The Pepsi Corporation faced a crisis in 1993 which started with claims of syringes being found in cans of diet Pepsi. Pepsi urged stores not to remove the product from shelves while it had the cans and the situation investigated. This led to an arrest, which Pepsi made public and then followed with their first video news release, showing the production process to demonstrate that such tampering was impossible within their factories. A second video news release displayed the man arrested. A third video news release showed surveillance from a convenience store where a woman was caught replicating the tampering incident. The company simultaneously publicly worked with the FDA during the crisis. The corporation was completely open with the public throughout, and every employee of Pepsi was kept aware of the details.^{[citation needed]} This made public communications effective throughout the crisis. After the crisis had been resolved, the corporation ran a series of special campaigns designed to thank the public for standing by the corporation, along with coupons for further compensation. This case served as a design for how to handle other crisis situations.^{[20][citation needed]}

Examples of unsuccessful crisis management

Bhopal

The Bhopal disaster in which poor communication before, during, and after the crisis cost thousands of lives, illustrates the importance of incorporating cross-cultural communication in crisis management plans. According to American University’s Trade Environmental Database Case Studies (1997), local residents were not sure how to react to warnings of potential threats from the Union Carbide plant. Operating manuals printed only in English is an extreme example of mismanagement but indicative of systemic barriers to information diffusion. According to Union Carbide’s own chronology of the incident (2006), a day after the crisis Union Carbide’s upper management arrived in India but was unable to assist in the relief efforts because they were placed under house arrest by the Indian government. Symbolic intervention can be counter productive; a crisis management strategy can help upper management make more calculated decisions in how they should respond to disaster scenarios. The Bhopal incident illustrates the difficulty in consistently applying management standards to multi-national operations and the blame shifting that often results from the lack of a clear management plan.^[21]

Ford and Firestone Tire and Rubber Company

The Ford-Firestone Tire and Rubber Company dispute transpired in August 2000. In response to claims that their 15-inch Wilderness AT, radial ATX and ATX II tire treads were separating from the tire core—leading to grisly, spectacular crashes—Bridgestone/Firestone recalled 6.5 million tires. These tires were mostly used on the Ford Explorer, the world's top-selling sport utility vehicle (SUV).^[22]
The two companies committed three major blunders early on, say crisis experts. First, they blamed consumers for not inflating their tires properly. Then they blamed each other for faulty tires and faulty vehicle design. Then they said very little about what they were doing to solve a problem that had caused more than 100 deaths—until they got called to Washington to testify before Congress.^[23]

Exxon

On March 24, 1989, a tanker belonging to the Exxon Corporation ran aground in the Prince William Sound in Alaska. The Exxon Valdez spilled millions of gallons of crude oil into the waters off Valdez, killing thousands of fish, fowl, and sea otters. Hundreds of miles of coastline were polluted and salmon spawning runs disrupted; numerous fishermen, especially Native Americans, lost their livelihoods. Exxon, by contrast, did not react quickly in terms of dealing with the media and the public; the CEO, Lawrence Rawl, did not become an active part of the public relations effort and actually shunned public involvement; the company had neither a communication plan nor a communication team in place to handle the event—in fact, the company did not appoint a public relations manager to its management team until 1993, 4 years after the incident; Exxon established its media center in Valdez, a location too small and too remote to handle the onslaught of media attention; and the company acted defensively in its response to its publics, even laying blame, at times, on other groups such as the Coast Guard. These responses also happened within days of the incident.^[24]

Lessons learned in crisis management

Impact of catastrophes on shareholder value

One of the foremost recognized studies conducted on the impact of a catastrophe on the stock value of an organization was completed by Dr Rory Knight and Dr Deborah Pretty (1995, Templeton College, University of Oxford - commissioned by the Sedgewick Group). This study undertook a detailed analysis of the stock price (post impact) of organizations that had experienced catastrophes. The study identified organizations that recovered and even exceeded pre-catastrophe stock price, (Recoverers), and those that did not recover on stock price, (Non-recoverers). The average cumulative impact on shareholder value for the recoverers was 5% plus on their original stock value. So the net impact on shareholder value by this stage was actually positive. The non-recoverers remained more or less unchanged between days 5 and 50 after the catastrophe, but suffered a net negative cumulative impact of almost 15% on their stock price up to one year afterwards.
One of the key conclusions of this study is that "Effective management of the consequences of catastrophes would appear to be a more significant factor than whether catastrophe insurance hedges the economic impact of the catastrophe".
While there are technical elements to this report it is highly recommended to those who wish to engage their senior management in the value of crisis management.^{[citation needed]}

Crisis as Opportunity

To address such shareholder impact, management must move from a mindset that manages crisis to one that generates crisis leadership. ^[6] Research shows that organizational contributory factors affect the tendency of executives to adopt an effective "crisis as opportunity" mindset. ^[25] Since pressure is both a precipitator and consequence of crisis, leaders who perform well under pressure can effectively guide the organization through such crisis. ^[26]
James contends that most executives focus on communications and public relations as a reactive strategy. While the company’s reputation with shareholders, financial well-being, and survival are all at stake, potential damage to reputation can result from the actual management of the crisis issue.^[6] Additionally, companies may stagnate as their risk management group identifies whether a crisis is sufficiently “statistically significant”. ^[27] Crisis leadership, on the other hand, immediately addresses both the damage and implications for the company’s present and future conditions, as well as opportunities for improvement. ^[8]

Public sector crisis management

Corporate America is not the only community that is vulnerable to the perils of a crisis. Whether a school shooting, a public health crisis or a terrorist attack that leaves the public seeking comfort in the calm, steady leadership of an elected official, no sector of society is immune to crisis. In response to that reality, crisis management policies, strategies and practices have been developed and adapted across multiple disciplines.

Schools and crisis management

In the wake of the Columbine High School Massacre, the September 11 attacks in 2001, and shootings on college campuses including the Virginia Tech massacre, educational institutions at all levels are now focused on crisis management.^[28]
A national study conducted by the University of Arkansas for Medical Sciences (UAMS) and Arkansas Children’s Hospital Research Institute (ACHRI) has shown that many public school districts have important deficiencies in their emergency and disaster plans (The School Violence Resource Center, 2003). In response the Resource Center has organized a comprehensive set of resources to aid schools is the development of crisis management plans.^{[citation needed]}
Crisis management plans cover a wide variety of incidents including bomb threats, child abuse, natural disasters, suicide, drug abuse and gang activities – just to list a few.^[29] In a similar fashion the plans aim to address all audiences in need of information including parents, the media and law enforcement officials.^[30]

Government and crisis management

Historically, government at all levels – local, state, and national – has played a large role in crisis management. Indeed, many political philosophers have considered this to be one of the primary roles of government. Emergency services, such as fire and police departments at the local level, and the United States National Guard at the federal level, often play integral roles in crisis situations.
To help coordinate communication during the response phase of a crisis, the U.S. Federal Emergency Management Agency (FEMA) within the Department of Homeland Security administers the National Response Plan (NRP). This plan is intended to integrate public and private response by providing a common language and outlining a chain-of-command when multiple parties are mobilized. It is based on the premise that incidences should be handled at the lowest organizational level possible. The NRP recognizes the private sector as a key partner in domestic incident management, particularly in the area of critical infrastructure protection and restoration.^[31]
The NRP is a companion to the National Incidence Management System that acts as a more general template for incident management regardless of cause, size, or complexity.^[31]
FEMA offers free web-based training on the National Response Plan through the Emergency Management Institute.^[32]
Common Alerting Protocol (CAP) is a relatively recent mechanism that facilitates crisis communication across different mediums and systems. CAP helps create a consistent emergency alert format to reach geographically and linguistically diverse audiences through both audio and visual mediums.^{[citation needed]}

Elected officials and crisis management

Historically, politics and crisis go hand-in-hand. In describing crisis, President Abraham Lincoln said, “We live in the midst of alarms, anxiety beclouds the future; we expect some new disaster with each newspaper we read.”^{[citation needed]}
Crisis management has become a defining feature of contemporary governance. In times of crisis, communities and members of organizations expect their public leaders to minimize the impact of the crisis at hand, while critics and bureaucratic competitors try to seize the moment to blame incumbent rulers and their policies. In this extreme environment, policy makers must somehow establish a sense of normality, and foster collective learning from the crisis experience.^[33]
In the face of crisis, leaders must deal with the strategic challenges they face, the political risks and opportunities they encounter, the errors they make, the pitfalls they need to avoid, and the paths away from crisis they may pursue. The necessity for management is even more significant with the advent of a 24-hour news cycle and an increasingly internet-savvy audience with ever-changing technology at its fingertips.^[33]
Public leaders have a special responsibility to help safeguard society from the adverse consequences of crisis. Experts in crisis management note that leaders who take this responsibility seriously would have to concern themselves with all crisis phases: the incubation stage, the onset, and the aftermath. Crisis leadership then involves five critical tasks: sense making, decision making, meaning making, terminating, and learning.^[33]
A brief description of the five facets of crisis leadership includes:^[34]

1. Sense making may be considered as the classical situation assessment step in decision making.
2. Decision making is both the act of coming to a decision as the implementation of that decision.
3. Meaning making refers to crisis management as political communication.
4. Terminating a crisis is only possible if the public leader correctly handles the accountability question.
5. Learning, refers to the actual learning from a crisis is limited. The authors note, a crisis often opens a window of opportunity for reform for better or for worse.

Professional Organizations

There are a number of professional industry associations that provide advice, literature and contacts to turnaround professionals and academics. Some are:
1. Turnaround Management Society (International / Focus on Europe)
2. Institute for Turnaround (England)
3. Turnaround Management Association (International)
4. Institut für die Standardisierung von Unternehmenssanierungen (Germany)

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References

1. ^ Seeger, M. W.; Sellnow, T. L., & Ulmer, R. R. (1998). "Communication, organization and crisis". Communication Yearbook 21: 231–275. 
2. ^ Venette, S. J. (2003). Risk communication in a High Reliability Organization: APHIS PPQ's inclusion of risk in decision making. Ann Arbor, MI: UMI Proquest Information and Learning.
3. ^ "Incident or crisis? Why the debate?". http://www.continuitycentral.com/feature0447.htm. 
4. ^ ^{a b c d e f g h i} Coombs, W. T. (1999). Ongoing crisis communication: Planning, managing, and responding. Thousand Oaks, CA: Sage. 
5. ^ ^{a b c d e} Lerbinger, O. (1997). The crisis manager: Facing risk and responsibility. Mahwah, NJ: Erlbaum. 
6. ^ ^{a b c} "Crisis Leadership". http://papers.ssrn.com/sol3/papers.cfm?abstract_id=1281843&rec=1&srcabs=224055. Retrieved 2010-06-22. 
7. ^ James, E. (Spring 2007). "Leadership as (Un)usual: How to Display Competence InTimes of Crisis". Leadership Preview. http://www.leadershipreview.org/2007spring/Article4.pdf. Retrieved 2010-06-22. 
8. ^ ^{a b c d} James, E. (Spring 2007). "Leadership as (Un)usual: How to Display Competence In Times of Crisis". Leadership Preview. http://www.leadershipreview.org/2007spring/Article4.pdf. Retrieved 2010-06-22. 
9. ^ James, Erika; Roberts, J (2009). "In the wake of the financial crisis: rebuilding the image of the finance industry through trust". Journal of Financial Transformation 125 (2): 601–7. PMID RePEc:ris:jofitr:1382. PMC 236121. http://econpapers.repec.org/article/risjofitr/1382.htm. Retrieved 2010-06-22. 
10. ^ ^{a b c} "Rigor and Relevance in Management". 12Manage.com. http://www.12manage.com/methods_crisis_management_advice.html. Retrieved 2007-10-11. 
11. ^ Infante, D.; Rancer, A., & Womack, D. (1997). Building communication theory (3rd ed.). Prospect Heights, IL: Waveland Press. 
12. ^ Coombs, W. T. (2007). Ongoing Crisis Communication: Planning, Managing, and Responding (2nd ed.). Thousand Oaks, CA: Sage.