Computer Science

Key Unit Competency
By the end of the unit, you should be able to integrate safety guideline, ergonomics and ethical issues in computer use to have a good working environment.

Unit Outline
• General safety guidelines
• Ethical issues

Introduction
Although computers are useful tools, they can be harmful to health and environment. Furthermore, some computer components are delicate hence need to be handled with care. In this unit, we discuss safety precautions and ethical use of computers in order to protect the environment, computers and users from harm.

3.1 General Safety Guidelines
To achieve productivity and healthy work or learning environment, most organizations put in place safety precaution guidelines to be observed when using mechanical or electronic devices. In this section, we discuss some of general safety guidelines that relate to safe use and care of computers and computer accessories. As a guide to ’best practice’, the guidelines and procedure discussed reflects identification precaution against common health problems, fire outbreaks, physical damage, climatic and environmental pollution.

3.1.1 Common health problems
Prolonged use of computers and electronic devices may expose users to health risks such as Repetitive Strain Injuries (RSI), eye strain, headache, dizziness and electric shock. Below is a brief description of common health conditions arising from use of computers and electronic devices:
• Repetitive strain injuries results from wrist, hand, muscle, tendonitis and neck strains due to repetitive tasks such as typing.
• Persistent use or poor display of a computer monitor may cause computer vision syndrome whose symptoms include eyestrain, headaches and double vision.

• Dizziness is a condition caused by lack of enough oxygen due to overcrowding or poor ventilation of a computer lab.
• Electric shock may be caused by touching live uninsulated power cables. To protect users against electric shock, power cables and power sockets should be well insulated.

Activity 3.1: Safe Use of Computers
1. In groups, identify five factors that need to be considered in order to minimize health risks such as RSI and eye strain.
2. Electric power cables or surface of unearthed electronic equipment may expose users to health risk. Identify such health risks.
3. Explain why it is not advisable to take food substances and drinks in the computer lab.
4. In class, discuss effects of electromagnetic and radiowaves emitted by electronic devices such as monitors and mobile phones. How can the effects be minimized?

3.1.2 Ergonomic furniture and equipment
The term ergonomic refers to applied science of equipment design with the purpose of optimising productivity while minimizing discomfort and fatigue. Good organic furniture and equipment helps in preventing health related risks such as arthritis, backache and fatigue. For example, a chair should be adjustable or movable to minimize fatigue experienced when using a computer.
Fig. 3.1 shows a sample of a table and adjustable chair that may be used in an office for computer laboratory. Notice that the chair has an upright backrest and high enough to allow user’s line of sight to be at the same level with top of the monitor.

3.1.3 Correct sitting position
The correct sitting position is the posture in which you hold your sit or use ergonomic
furniture to keep the bones and joints in the correct alignment. This helps in decreasing
abnormal wearing of joint surfaces as well as reduce stress, backache, eye strain and
fatigue. Good sitting position requires a table to be of the right height relative to
the chair to provide comfortable hand positioning as shown in Figure 3.2. The seat
should have an upright backrest and should be high enough to allow the eyes of the
user to be level with the top of the screen.

3.1.4 Fire Safety Guidelines
To protect computers and electronic equipment from accidental fire, there is need
for schools to enforce fire safety guidelines. Fire safety guidelines should emphasize
among other measures on where, how and when to use smoke detectors and fire
extinguishers.

3.1.1.1 Smoke detectors
A smoke detector shown in Fig. 3.3(a) is a device used to detect smoke as an indicator
of fire outbreak. Once a smoke detector senses smoke, it may trigger a fire alarm
systems or produce audible and visual signal.

3.1.1.2 Fire extinguishers
A fire extinguisher (Fig. 3.3(b)) is a fire protection device used extinguish or control
fire on solids, flammables and electrical devices. The four common types of fire
extinguishers are water fire extinguishers, foam fire extinguisher, dry powder fire
extinguishers and carbon dioxide (CO2) fire extinguishers. Although the water-based
fire extinguishers are the cheapest and most common, it is advisable to install carbon
dioxide (CO2) fire extinguishers in a computer laboratory. This is because water may cause corrosion of metallic components while dry powder may increase friction and
wear of mechanical parts.

Activity 3.2: Fire Safety Guidelines
Visit various rooms in the school compound to identify whether the fire extinguishers
have been installed. If installed:
• What is the content of the extinguisher - liquid or non-liquid?
• Write down instructions provided on how use one of the extinguishers.
• Explain why liquid-based fire extinguishers are not recommended for use in a
computer lab.

3.1.3 Physical Damage
Computers and electronic devices should be protected from physical damage that
may emanate from poor handling, electrostatic discharge (ESD) and unstable power
supply.

3.1.5.1 Electrostatic Discharge
While opening a door with a metallic door when walking on a carpet, you may have experienced some form of electric shock. Such an experience is referred to as electrostatic discharge. Electrostatic discharge (ESD) refers to flow of static electricity when two triboelectric objects come into contact. Triboelectric objects are those that develop an electric charge when they rub against each other due to friction. ESD that is caused by build-up of electrostatic charges on your body! Fig. 3.4 shows an illustration of a symbol used to mark devices that are ESD sensitive.

Activity 3.3: Electrostatic Discharge
1. In reference to physics or electronics, explain the principle behind static electricity and electrostatic discharge. Identify common examples of triboelectric objects.
2. In groups, conduct practical experiments to demonstrate how static electricity builds up on our dielectric materials. How do you measure electrostatic voltage?
3. Discuss some of the risks posed by electrostatic discharges and how to prevent such risks from damaging electronic components.

3.1.6 Power devices
Computers and electronic devices require stable and correctly rated electric power. To protect the computer from damage that may be caused by irregular power supply, two commonly used devices are surge suppressors and Uninterruptible Power Supply (UPS). A surge suppressor also known as surge protector such as the one shown in Fig 3.5(a) is a device used to limit voltage supplied to electrical appliances. For example if the input voltage is more than 240 volts, the surge suppressor steps it down to a maximum of 240 volts hence protecting devices from electrical damage.

An uninterruptible power supply UPS such as shown in Fig. 3.5(b) is device that provides emergency power backup in case the main power source fails.

                             Activity 3.4: Power Protection Devices
1. In the computer lab or school compound, demonstrate how a standard UPS can be connected to a computer.
2. Research from internet how UPS regulates power supply to computers in case of
power surge, brownout or blackout.
3. Assuming the school intends to purchase several UPS units to setup in a new
computer lab of forty computers. Advise the management factors to consider
before purchasing the UPS.

                          3.1.7 Climatic Change
Climatic change may affect computers and electronic equipment in a number of ways. For example, high temperatures affect functioning of semiconductor chips, while with high humidity causes corrosion of metallic components. To protect computers from damage during dry weather, dust covers and spread air conditioners should be used.

                 3.1.8 Protecting Environment from contamination
Poor disposal of e-waste such as computer parts, CRT and LCD monitors, batteries, toner cartridges, plastic bags, chemical solvents, and printers such as the one shown in Fig.3.6 poses great environment risk. For example, long-term exposure to chemicals and components containing lead, candium, chromium, and mercury damages the nervous system, kidneys, bones, and endocrine system. Therefore, disposal of such e-wastes is not advisable and therefore should be regulated by establishing policy guidelines to avoid health risks and environmental pollution.

                               Activity 3.5: Computers and Environmental Protection
1. Define the term e-waste and discuss in class why it is important for Rwanda government to enforce e-waste disposal legislation and policy guidelines.
2. Disposable computers and electronic equipment may contain valuable components precious metals, glass and plastics which if recovered could provide business opportunities. Demonstrate your innovation and entrepreneurship skills by forming mock-up business entities that converts e-waste into commercial products.

                                   3.2 Ethical issues
The term ethics refers to a set of moral principles that govern the behaviour of an individual or society. In this regard, computer ethic refers to a set of moral principles that regulate use of computers. In this era termed as information age, lack of laws and standards on use of connected devices such as computers and mobile phone has raised numerous ethical concerns. The following are ethical issues that should be addressed at individual, social, and political level:
• Flaming: Flaming refers to messages that contain offensive, obscene or immoral words spread via social media applications such as WhatsApp and Facebook.
• Forgery: Availability of computers and high resolution imaging devices has made it possible for criminals to forge certificates, money and identity cards.
• Piracy: Piracy is a form of theft on intellectual property on copyrighted software products without proper authorization. To avoid violation of copyright laws, you need to understand various software licenses. These are commercial (propriety), freeware, shareware and open source discussed in the next unit under software installations.
• Terrorism: High penetration of internet and mobile phones has exposed most countries to evil plans of terrorists across the globe.
• Pornography: Availability of pornographic material in form of pictures and video has affected moral values of young children leading to immoral behaviour such as homosexuality and pre-marital sex.
• Fraud: Computers and mobile phones are being used to steal other people’s account details or money through fraudulent means such as fake websites and SMS messages.
• Corruption: Corruption has become social evil in private and public institution because it is seen as the easiest means to gaining social, economic or political favours. In some countries, mobile and internet-based money transfer has opened doors to corrupt behaviour that goes unnoticed by law enforcement agents.

Activity 3.6: Ethical Issues
1. In goups, brainstorm on how technology use has influenced our morals in terms
of communication, privacy and intellectual property rights.
2. In open class discussion, brainstorm on ethical challenges arising from the use
of computers and mobile devices.
3. On the internet, search for the ten commandments of computer ethics proposed
by Computer Ethics Institute.
4. In group discussions, identify open source or proprietary software installed in the
computers indicating the intellectual property or copyright owner.

Unit Test 3
1. Identify two alternative sources of backup power in case of blackout or brownout of main electricity.
2. Explain why it is important to avoid overcrowding in a computer lab.
3. Outline the procedure you would follow to put out fire in a computer lab that may have been caused by electrical fault.
4. Explain why it is not advisable to eat or drink in a computer lab.
5. State two reasons that make use powder-based fire extinguishers in a computer
lab unsuitable.
6. Differentiate between UPS and surge suppressors in terms of functionality.
7. Identify some of the causes of health risks such as computer vision syndrome,
back pain and failure of endocrine system.
8. Discuss the concept of ergonomics in terms of keyboard layout, office furniture,
and adjustable computer displays.
9. Outline policy guidelines that regulate acquisition and disposal of ICT equipment
outlined in Rwanda’s e-waste disposal policy.
10. In reference to computer software, explain three types of end-user licenses giving
an example of each.