CHAPTER 2 : ELECTRON THEORY
Briefly explain the difference between elements and compounds. Give two
examples of each.
List and identify the electric charges associated with the three elementary particles
that form Bohrs model of the atom.
the specification and should supply these facts as the client. This is likely to
require joint effort with the designer. However, the supplier or designer may need
to prompt the employer because employers do not procure new LEV very often.
Complex LEV sys
cloud. 43 LEV needs to remove both suspended inhalable particles and intercept
the larger particles. For some processes, eg on a woodworking saw, LEV collects
and conveys both dust and chips. Controlling airborne contaminants at work Page
14 of 109 Health
109 Health and Safety Executive Criteria for an LEV quotation 77 The suppliers
more detailed quotation should: provide technical drawings of the system; state
the type of hood for each source, its location or position, face velocity, static
Properties of airborne contaminants Key points Gases, vapours, dusts, fumes and
mists arise differently. Airborne contaminants move in the air in which they are
mixed or suspended. 33 This chapter descibes the behaviour of airborne
contaminants and remove
contaminant cloud. For example, an LEV hood capable of reducing exposure 10fold is unsuitable to control a source capable of emission at 50 times a benchmark
exposure value. However, there is limited information on the effectiveness of LEV.
Figure 9 propo
a process. Understanding the process means understanding the creation of
sources. This can suggest ways to modify the process to reduce the number or
size of sources, and contaminant clouds. The effective application of LEV requires
a good understanding o
systems contain, capture or receive the contaminant cloud within the LEV hood
and conduct it away. The greater the degree of enclosure of the source, the more
likely it is that control will be successful. Good practice requires monitoring the
with a possible dust explosion. This book does not cover flammability issues such
as zoning9 or explosion relief.10 Where such hazards exist, the design needs to
take them into account. The Dangerous Substances and Explosive Atmospheres
8). Alternatively, if smoke is released into the cloud, this will show up its shape,
size, speed and direction. This information is essential for applying suitable LEV.
Movement of particles in air 41 Particles in contaminant clouds move with the air
coloured at high concentrations. Chlorine, carbon monoxide. Controlling airborne
contaminants at work Page 13 of 109 Health and Safety Executive 36 There are
strict definitions and standardised methods for sampling inhalable and respirable
Dumping dusty sacks on a surface. Machinery vibration re-suspending settled dust.
Shock of the physical impact or vibration creates a dust cloud. Dust-contaminated
clothing can also create a dust cloud. Settled dust can resuspend in the air. Dust.
A System View of Optical Fiber
An optical fiber is a glass or plastic fiber designed to guide light along
its length by total internal reflection. Fiber optics is the branch of applied
science and engineering concerned with such op
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extraction Downdraught table Low volume high velocity (LVHV) Simple
capturing hood Other receiving hoods Partial enclosure booth Moveable source
and hood Figure 10 Classification: Types of LEV hood Controlling airborne
contaminants at work Page 28 of 109
contamination; should specify that the supplier provides training in how to use,
check and maintain the LEV system; should require that the supplier provides a
user manual that describes and explains the LEV system, and how to use, check,
maintain and tes
and moves with the workroom air. 50 Figure 3 shows what commonly happens.
The vapourair cloud flows away from the top of the mixer and mixes with the
workroom air, directly causing exposure. It also flows down the mixing vessel
sides, all the time mixing
Minimise the containers open area. Make the container a receiving hood. Other
controls, eg: pump liquids through pipes extending to the bottom of the
container; use a vapour recovery system. Controlling airborne contaminants at
work Page 19 of 109 Health
control measures consist of a mixture of control hardware (engineering control)
and work practices (working procedures and methods). Control hardware 63 This
means all equipment, alerts and design features to control contaminant clouds. It
airborne contaminants at work Page 17 of 109 Health and Safety Executive
Explosive release Figure 5 Processes and sources in stonemasonry Progressive
release Doughnut-shaped release around rotating disc Broad fan-shaped release
from rotating disc Narrow j
Description and size Visibility Examples Dust Solid particles can be supplied, eg
powder-handling, or process generated, eg crushing and grinding. Inhalable
particle size 0.01 to 100 m. Respirable particle size below 10 m. In diffuse light:
the cloud grows through mixing and diffusion. Dilution reduces the concentration
of the contaminant in the cloud. But it is always more effective to apply control
close to the source of an airborne release because: the cloud volume is smaller,
so it is ea
dust-laden air moving with the rotating disc. Fit a receiving hood to the guard.
Use LVHV (low volume high velocity extraction). Other controls, eg: water
suppression. Hot (and cold) processes Furnaces and casting. Soldering and brazing.
Welding. Using l
LOGIC GATES (PRACTICE PROBLEMS)
Key points and summary First set of problems from Q. Nos. 1 to 9 are based on the logic
gates like AND, OR, NOT, NAND & NOR etc.
First four problems are basic in nature. Problems 3 & 4 are based on word statement.
The MC68HC11 Microcontoller
August 26, 2004
What would we learn about ?
I. INTRODUCING MICROCONTROLLER TECHNOLOGY
1. Microcontroller Concepts.
3. The S
National Exams December 2011
07-Elec-B6 Integrated Circuit Engineering
3 Hours Duration
Ifdoubt exists as to the interpretation of any question, the candidate is urged
to submit With the answer paper a clear statement of any assumptions made.
EE 3170 Microcontroller
Lecture 13: Introduction to Microcontroller Hardware (Part
- Miller 6.1 - 6.12
Describe the I/O ports of the 6811
Explain the basic parts of I/O programming
Give examples of I/O device driv