Environmental health science lecture notes

environmental health science job opportunities environmental health a global access science source
LeonBrown Profile Pic
LeonBrown,Hawaii,Researcher
Published Date:14-07-2017
Your Website URL(Optional)
Comment
LECTURE NOTES For Environmental Health Science Students Engineering Drawing Wuttet Taffesse, Laikemariam Kassa Haramaya University In collaboration with the Ethiopia Public Health Training Initiative, The Carter Center, the Ethiopia Ministry of Health, and the Ethiopia Ministry of Education 2005 Funded under USAID Cooperative Agreement No. 663-A-00-00-0358-00. Produced in collaboration with the Ethiopia Public Health Training Initiative, The Carter Center, the Ethiopia Ministry of Health, and the Ethiopia Ministry of Education. Important Guidelines for Printing and Photocopying Limited permission is granted free of charge to print or photocopy all pages of this publication for educational, not-for-profit use by health care workers, students or faculty. All copies must retain all author credits and copyright notices included in the original document. Under no circumstances is it permissible to sell or distribute on a commercial basis, or to claim authorship of, copies of material reproduced from this publication. ©2005 by Wuttet Taffesse, Laikemariam Kassa All rights reserved. Except as expressly provided above, no part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without written permission of the author or authors. This material is intended for educational use only by practicing health care workers or students and faculty in a health care field. PREFACE The problem faced today in the learning and teaching of engineering drawing for Environmental Health Sciences students in universities, colleges, health institutions, training of health center emanates primarily from the unavailability of text books that focus on the needs and scope of Ethiopian environmental students. This lecture note has been prepared with the primary aim of alleviating the problems encountered in the teaching of Engineering Drawing course and in minimizing discrepancies prevailing among the different teaching and training health institutions. It can also be used as a reference material for professional sanitarians. The graphics of engineering design and construction may very well be the most important course of all studies for an engineering or technical career. The indisputable reason why graphics or drawing is so extremely important is that it is the language of the designer, technician, sanitarian, and engineer, used to communicate designs and construction details to others. The language of graphics is written in the form of drawings that represent the shape, size, and specifications of physical objects. The language is read by interpreting drawings so that physical objects can be constructed exactly as originally conceived by the designer. i This lecture note is devoted to provide general aspects of graphic communication like geometric construction, orthographic projections, maps etc particularly for environmental sanitation works such as dry pit latrine construction, drainage or sewerage construction etc. Each chapter begins by specifying learning objectives. The text and the self-explanatory drawings are much helpful to understand the subject even for the beginners. More over, other subsidiary topics like sectioning, projection of points and lines are added to enable students acquire concrete knowledge and skill for their professional career. Finally, it contains a glossary, which summarizes important terminologies used in the text. For further reading, students are encouraged to refer books which are listed in the bibliography section. ii Acknowledgement We are delighted to express our thanks to the carter center for the financial, material and moral support with out which this material wouldn’t come to reality. We are also glad to extend our heart felt appreciation for Ato Esayas Alemayehu, Ato Muluken Eyayu, Ato Wossen Tafere and Ato Dagnew Engidaw for their critical and constructive comments that are found to be highly essential for this lecture note preparation. We are very happy to be members of the faculty of health sciences, Alemaya university for the fact that working with such faculty are really incomparable. iii TABLE OF CONTENTS Preface ............................................................................... i Acknowledgement ................................................................ iii General Objectives ............................................................... vii Chapter 1: Introduction to Graphic Communication ............ 1 1.1. Drawing .................................................................. 1 1.1.1 Artistic Drawings .......................................... 2 1.1.2. Technical Drawings ...................................... 3 Chapter 2: Drawing Equipments and Their Use .................. 11 2.1. Introduction ............................................................ 11 2.2. Important Drawing Equipments .................... 11 Chapter 3: Lettering and Lines ............................................ 22 3.1. Letter Styles ........................................................... 22 3.2. Technique Of Lettering ........................................... 24 3.2.1. .Guide Lines ................................................. 24 3.3. Spacing Of Letters ................................................. 30 3.4. Lettering In Maps ................................................... 31 3.5. Conventional Lines ................................................ 31 Chapter 4: Geometric Construction ..................................... 35 4.1. 1 Introduction ......................................................... 35 4.2. Geometric Nomeniclature ...................................... 36 4.3. Techniques of Geometric Constructions ................ 42 Chapter 5: Projection ......................................................... 66 5.1. Introduction ........................................................... 67 5.1.1. Isometric Drawing ........................................ 68 5.1.2. Orthographic Or Multi View Projection ......... 70 5.2. Theory Of Multi View Projections ........................... 72 5.2.1. Orthographic Projection ............................... 74 iv 5.2.2. Classification of Surfaces and Lines in Orthographic Projections ................................ 82 5.2.3. Precedence of Lines .................................... 89 5.3. Pictorial Projections .............................................. 90 5.3.1. Isometric Projection ..................................... 94 5.3.2. Isometric Drawing ........................................ 96 Chapter 6: Sectioning .......................................................... 101 6.1. Sectional Views .................................................... 101 6.2. How Sections Are Shown ..................................... 106 6.3. Multsection Views ................................................ 109 Chapter 7: Projection of Points, Lines and Planes .............. 116 7.1. Introduction .......................................................... 117 7.2. Reference Planes ................................................. 118 7.3. Projection of Point ................................................ 119 7.4. Lines in Space ...................................................... 120 7.4.1. Classification Of Lines In Orthographic Projections ................................................ 121 7.4.2 Orthographic Projection Of A Line ............... 124 7.4.3. True Size (Shape) Of An Oblique Plane .... 146 Chapter 8: Dimensioning ..................................................... 149 8.1. Introduction .......................................................... 149 8.2. Definitions ............................................................ 150 8.3. Steps in Dimensioning .......................................... 152 8.4. Where to Put Dimensions ..................................... 153 Chapter 9: Mapping ............................................................. 159 9.1. Introduction .......................................................... 159 9.2. Definition ............................................................. 160 9.3. Purpose ................................................................ 161 9.4. Classification of Maps .......................................... 162 9.5. Sketch Map .......................................................... 166 9.6. Materials Used In a Sketch Mapping For Field or Office Use ............................................................ 172 9.7. Procedures for Making a Sketch Map ................. 172 v Chapter 10: Building Drawing ............................................. 176 10.1. Introduction ........................................................ 176 10.2. Important Terms Used In Building Drawing ....... 177 10.3. Principles of Architecture .................................... 180 10.4. Basic Elements of Planning Residential Building 182 10.5. Principles of Planning Of Residential Building .... 175 10.6. Specification Used To Draw the Building Drawing 189 10.7. Methods of Making Line and Detailed Drawing .. 191 10.8. Tips to Draw Building Drawing ........................... 194 Chapter 11. Application of Engineering Drawing In Environmental Health Projects ....................... 206 Introduction ................................................................. 206 A. Sanitation Projects .................................................. 207 B. Water Projects ........................................................ 227 Bibliography ......................................................................... 231 vi GENERAL OBJECTIVES This lecture notes will enable the students to: I. Explain the concept of graphic communication, their type and their role in sanitary construction. II. Familiarize with different drawing equipment, technical standards and procedures for construction of geometric figures. III. Equipped with the skill that enables them to convert pictorial (3-D) drawings to orthographic (2-D) drawings and vice versa. IV. Explain the principle and application of sectioning. V. Well familiar with the purpose, procedures, materials and conventional symbols utilized to make sketch maps. vii CHAPTER ONE INTRODUCTION TO GRAPHIC COMMUNICATION Objectives: At the end of this chapter students should be able to: ♦ Define graphic communication ♦ Mention types of drawing ♦ Explain the difference between different types of drawings ♦ Mention some of the applications of technical drawings 1.1 Drawing A drawing is a graphic representation of an object, or a part of it, and is the result of creative thought by an engineer or technician. When one person sketches a rough map in giving direction to another, this is graphic communication. Graphic communication involves using visual materials to relate ideas. Drawings, photographs, slides, transparencies, and sketches are all forms of graphic communication. Any medium that uses a graphic image to aid in conveying a message, instructions, or an idea is involved in graphic communication. 1 One of the most widely used forms of graphic communication is the drawing. Technically, it can be defined as “a graphic representation of an idea, a concept or an entity which actually or potentially exists in life. Drawing is one of the oldest forms of communicating, dating back even farther than verbal communication. The drawing itself is a way of communicating all necessary information about an abstract, such as an idea or concept or a graphic representation of some real entity, such as a machine part, house or tools. There are two basic types of drawings: Artistic and Technical drawings. 1.1.1 Artistic Drawings Artistic Drawings range in scope from the simplest line drawing to the most famous paintings. Regardless of their complexity, artistic drawings are used to express the feelings, beliefs, philosophies, and ideas of the artist. In order to understand an artistic drawing, it is sometimes necessary to first understand the artist. Artists often take a subtle or abstract approach in communicating through their drawings, which in turn gives rise to various interpretations. (see figure 1.1) 2 Figure 1.1 Artistic drawings rd (Source: Goetsch, Technical drawing 3 ed. USA: Delmar Publisher Inc., 1994) 1.1.2 Technical Drawings The technical drawing, on the other hand, is not subtle, or abstract. It does not require an understanding of its creator, only an understanding of technical drawings. A technical drawing is a means of clearly and concisely communicating all of the information necessary to transform an idea or a concept in to reality. Therefore, a technical drawing often contains more than just a graphic representation of its subject. It also contains dimensions, notes and specifications. (See figure 1.2) 3 Figure 1.2 Technical Drawings A. Types of Technical Drawings Technical drawings are based on the fundamental principles of projections. A projection is a drawing or representation of an entity on an imaginary plane or planes. This projection planes serves the same purpose in technical drawing as is served by the movie screen. A projection involves four components 1. The actual object that the drawing or projection represents 4 2. The eye of the viewer looking at the object 3. The imaginary projection plane 4. Imaginary lines of sight called Projectors The two broad types of projections, both with several sub- classifications, are parallel projection and perspective projection. Parallel Projection Parallel Projection is a type of projection where the line of sight or projectors are parallel and are perpendicular to the picture planes. It is subdivided in to the following three categories: Orthographic, Oblique and Axonometric Projections. ♦ Orthographic projections: are drawn as multi view drawings, which show flat representations of principal views of the subject. ♦ Oblique Projections: actually show the full size of one view. ♦ Axonometric Projections: are three-dimensional drawings, and are of three different varieties: Isometric, Dimetric and Trimetric. 5 Figure 1.3 Orthographic multi view drawing Figure 1.4 Oblique drawing Figure 1.5 Axonometric drawing 6 Perspective Projection Perspective projections are drawings which attempt to replicate what the human eye actually sees when it views an object. There are three types of perspective projections: One- point, Two-point and Three-point Projections. Figure 1.6 Perspective drawing 7 B. Purpose of Technical Drawings To appreciate the need for technical drawings, one must understand the design process. The design process is an orderly, systematic procedure used in accomplishing a needed design. Any product that is to be manufactured, fabricated, assembled, constructed, built, or subjected to any other types of conversion process must first be designed. For example, a house must be designed before it can be built. C. Application of Technical Drawing Technical drawings are used in many different applications. They are needed in any setting, which involves design, and in any subsequent forms of conversion process. The most common applications of technical drawings can be found in the fields of manufacturing, engineering and construction. For instance, Surveyors, civil engineers, sanitarians use technical drawings to document such works as the layout of a new subdivisions, or the marking of the boundaries for a piece of property. Contractors and construction personnel use technical drawings as their blue prints in converting architectural and engineering designs in to reality. 8 Figure 1.7 Technical drawing (architectural) 9 Review questions 1. Discuss the different types of drawing 2. Explain the different application of technical drawing 3. What is graphic communication? 10 CHAPTER TWO DRAWING EQUIPMENTS AND THEIR USE Objectives: At the end of this chapter students should be able to: ♦ List the main drawing equipments ♦ Discuss the use of different drawing equipments 2.1 Introduction To record information on paper instruments and equipments are needed. Engineering drawing is entirely a graphic language hence instruments are essentially needed. Drawing must be clear, neat and legible in order to serve its purpose. Hence it is extremely important for engineers to have good speed, accuracy, legibility and neatness in the drawing work. 2.2 Important Drawing Equipments All drawings are made by means of various instruments. The quality of drawing depends to a large extent on the quality, adjustment and care of the instruments. 11

Advise: Why You Wasting Money in Costly SEO Tools, Use World's Best Free SEO Tool Ubersuggest.